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Sample records for allele substitution effects

  1. Correlated evolution of nucleotide substitution rates and allelic variation in Mhc-DRB lineages of primates

    PubMed Central

    Garamszegi, László Z; de Groot, Natasja G; Bontrop, Ronald E

    2009-01-01

    Background The major histocompatibility complex (MHC) is a key model of genetic polymorphism. Selection pressure by pathogens or other microevolutionary forces may result in a high rate of non-synonymous substitutions at the codons specifying the contact residues of the antigen binding sites (ABS), and the maintenance of extreme MHC allelic variation at the population/species level. Therefore, selection forces favouring MHC variability for any reason should cause a correlated evolution between substitution rates and allelic polymorphism. To investigate this prediction, we characterised nucleotide substitution rates and allelic polymorphism (i.e. the number of alleles detected in relation to the number of animals screened) of several Mhc class II DRB lineages in 46 primate species, and tested for a correlation between them. Results First, we demonstrate that species-specific and lineage-specific evolutionary constraints favour species- and lineage-dependent substitution rate at the codons specifying the ABS contact residues (i.e. certain species and lineages can be characterised by high substitution rate, while others have low rate). Second, we show that although the degree of the non-synonymous substitution rate at the ABS contact residues was systematically higher than the degree of the synonymous substitution rate, these estimates were strongly correlated when we controlled for species-specific and lineage-specific effects, and also for the fact that different studies relied on different sample size. Such relationships between substitution rates of different types could even be extended to the non-contact residues of the molecule. Third, we provide statistical evidence that increased substitution rate along a MHC gene may lead to allelic variation, as a high substitution rate can be observed in those lineages in which many alleles are maintained. Fourth, we show that the detected patterns were independent of phylogenetic constraints. When we used phylogenetic

  2. Transformation of QTL genotypic effects to allelic effects

    PubMed Central

    Nagamine, Yoshitaka

    2005-01-01

    The genotypic and allelic effect models are equivalent in terms of QTL detection in a simple additive model, but the QTL allelic model has the advantage of providing direct information for marker-assisted selection. However, the allelic matrix is four times as large as the genotypic IBD matrix, causing computational problems, especially in genome scans examining multiple positions. Transformation from genotypic to allelic effects, after estimating the genotypic effects with a smaller IBD matrix, can solve this problem. Although the validity of transformation from genotypic to allelic effects has been disputed, this work proves that transformation can successfully yield unique allelic effects when genotypic and allelic IBD matrixes exist. PMID:16093016

  3. Radiosensitivity of Human Fibroblasts is Associated With Amino Acid Substitution Variants in Susceptible Genes And Correlates With The Number of Risk Alleles

    SciTech Connect

    Alsbeih, Ghazi . E-mail: galsbeih@kfshrc.edu.sa; El-Sebaie, Medhat; Al-Harbi, Najla; Al-Buhairi, Muneera; Al-Hadyan, Khaled; Al-Rajhi, Nasser

    2007-05-01

    Purpose: Genetic predictive markers of radiosensitivity are being sought for stratifying radiotherapy for cancer patients and risk assessment of radiation exposure. We hypothesized that single nucleotide polymorphisms in susceptible genes are associated with, and the number of risk alleles has incremental effect on, individual radiosensitivity. Methods and Materials: Six amino acid substitution variants (ATM 1853 Asp/Asn G>A, p53 72 Arg/Pro G>C, p21 31 Ser/Arg C>A, XRCC1 399 Arg/Gln G>A, XRCC3 241 Thr/Met C>T, and TGF{beta}1 10 Leu/Pro T>C) were genotyped by direct sequencing in 54 fibroblast strains of different radiosensitivity. Results: The clonogenic survival fraction at 2 Gy range was 0.15-0.50 (mean, 0.34, standard deviation, 0.08). The mean survival fraction at 2 Gy divided the cell strains into radiosensitive (26 cases) and normal (28 controls). A significant association was observed between the survival fraction at 2 Gy and ATM 1853 Asn, XRCC3 241 Met, and TGF{beta}1 10 Leu alleles (p = 0.05, p = 0.02, and p = 0.02, respectively). The p53 72 Arg allele showed a borderline association (p = 0.07). The number of risk alleles increased with increasing radiosensitivity, and the group comparison showed a statistically significant difference between the radiosensitive and control groups (p {<=}0.001). Conclusion: The results of our study have shown that single nucleotide polymorphisms in susceptible genes influence cellular radiation response and that the number of risk alleles has a combined effect on radiosensitivity. Individuals with multiple risk alleles could be more susceptible to radiation effects than those with fewer risk alleles. These results may have implications in predicting normal tissue reactions to radiotherapy and risk assessment of radiation exposure.

  4. Temperature Sensitivity Conferred by ligA Alleles from Psychrophilic Bacteria upon Substitution in Mesophilic Bacteria and a Yeast Species

    PubMed Central

    Pankowski, Jarosław A.; Puckett, Stephanie M.

    2016-01-01

    We have assembled a collection of 13 psychrophilic ligA alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (TS) phenotype. When these ligA alleles were substituted into Francisella novicida, they conferred a TS phenotype with restrictive temperatures between 33 and 39°C. When the F. novicida ligA hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. For two alleles, the mutations that led to temperature resistance clustered near the 5′ end of the gene, and the mutations increased the predicted strength of the ribosome binding site at least 3-fold. Four F. novicida ligA hybrid strains generated no temperature-resistant variants at a detectable level. These results suggest that multiple mutations are needed to create temperature-resistant variants of these ligA gene products. One ligA allele was isolated from a Colwellia species that has a maximal growth temperature of 12°C, and this allele supported growth of F. novicida only as a hybrid between the psychrophilic and the F. novicida ligA genes. However, the full psychrophilic gene alone supported the growth of Salmonella enterica, imparting a restrictive temperature of 27°C. We also tested two ligA alleles from two Pseudoalteromonas strains for their ability to support the viability of a Saccharomyces cerevisiae strain that lacked its essential gene, CDC9, encoding an ATP-dependent DNA ligase. In both cases, the psychrophilic bacterial alleles supported yeast viability and their expression generated TS phenotypes. This collection of ligA alleles should be useful in engineering bacteria, and possibly eukaryotic microbes, to predictable TS phenotypes. PMID:26773080

  5. A leucine-to-proline substitution causes a defective [alpha]-antichymotrypsin allele associated with familial obstructive lung disease

    SciTech Connect

    Poller, W.; Scholz, S.; Fischer, M. ); Faber, J.P.; Tief, K.; Olek, K.; Kirchgesser, M. ); Weidinger, S. ); Heidtmann, H.H. )

    1993-09-01

    Using denaturing gradient gel electrophoresis and direct sequencing of amplified genomic DNA, the authors have identified two defective mutants of the human [alpha][sub 1]-antichymotrypsin (ACT) gene associated with chronic obstructive pulmonary disease (COPD). A leucine 55-to-proline substitution causing a defective ACT allele (Bochum-1) was observed in a family with COPD in three subsequent generations. Another mutation, proline 229-to-alanine (Bonn-1), was associated with ACT serum deficiency in four patients with a positive family history. These mutations were not detected among 100 healthy control subjects, suggesting a possible pathogenetic role of ACT gene defects in a subset of patients with COPD. 14 refs., 1 fig., 1 tab.

  6. Blood Substitutes: Effects on Drug Pharmacokinetics.

    DTIC Science & Technology

    1984-03-01

    RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS 1963-A - S . *.* , S. AD __ _ _ _ _? ,:-:t’ REPORT NUMBER: 2 BLOOD SUBSTITUTES: EFFECTS ON DRUG ...ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER.1-t 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED FINAL REPORT BLOOD SUBSTITUTES: EFFECTS ON DRUG ...Identify by block number) Blood substitutes; perfluorocarbons; stroma-free hemoglobin; drug pharmaco- kinetics S. ADST RACT (Cn*tfe am revere dm* if

  7. Characterization of DGAT1 allelic effects in a sample of North American Holstein cattle.

    PubMed

    Barbosa da Silva, Marcos Vinicius G; Sonstegard, Tad S; Thallman, Richard M; Connor, Erin E; Schnabel, Robert D; Van Tassell, Curt P

    2010-04-01

    A putative causative mutation underlying a QTL was identified as a lysine to alanine non-conservative substitution at amino acid 232 of the gene encoding the acylCoA:diacylglycerol acyltransferase (DGAT1) protein. Our goal was to characterize the allelic substitution effects of this DGAT1 mutation in a large sample of Holstein bulls from North America. Statistically significant effects were identified for all of the milk production traits and somatic cell scores. Estimated average effects of substituting the lysine allele for the alanine variant on Holstein bull daughter yield deviations were -81 kg, 3.7 kg, -1.1 kg, 0.063%, 0.012%, and -0.023 units for milk yield, fat yield, protein yield, fat component, protein component, and SCS, respectively. These estimates were largely in agreement with previous studies; however, the magnitudes of the estimates were much smaller in this study. Impacts on economic indices for net merit, cheese merit, and fluid merit were modest. Because of the strong antagonism between fat and protein yield and how those traits influence economic indices, selection for DGAT1 genotypes will likely not find widespread application in the U.S.

  8. Factors influencing the effect size distribution of adaptive substitutions

    PubMed Central

    Oakley, Christopher G.; Gould, Billie A.; Schemske, Douglas W.

    2016-01-01

    The distribution of effect sizes of adaptive substitutions has been central to evolutionary biology since the modern synthesis. Early theory proposed that because large-effect mutations have negative pleiotropic consequences, only small-effect mutations contribute to adaptation. More recent theory suggested instead that large-effect mutations could be favoured when populations are far from their adaptive peak. Here we suggest that the distributions of effect sizes are expected to differ among study systems, reflecting the wide variation in evolutionary forces and ecological conditions experienced in nature. These include selection, mutation, genetic drift, gene flow, and other factors such as the degree of pleiotropy, the distance to the phenotypic optimum, whether the optimum is stable or moving, and whether new mutation or standing genetic variation provides the source of adaptive alleles. Our goal is to review how these factors might affect the distribution of effect sizes and to identify new research directions. Until more theory and empirical work is available, we feel that it is premature to make broad generalizations about the effect size distribution of adaptive substitutions important in nature. PMID:27053750

  9. A nonsense nucleotide substitution in the oculocutaneous albinism II gene underlies the original pink-eyed dilution allele (Oca2(p)) in mice.

    PubMed

    Shoji, Haruka; Kiniwa, Yukiko; Okuyama, Ryuhei; Yang, Mu; Higuchi, Keiichi; Mori, Masayuki

    2015-01-01

    The original pink-eyed dilution (p) on chromosome 7 is a very old spontaneous mutation in mice. The oculocutaneous albinism II (Oca2) gene has previously been identified as the p gene. Oca2 transcripts have been shown to be absent in the skin of SJL/J mice with the original p mutant allele (Oca2(p)); however, the molecular genetic lesion underlying the original Oca2(p) allele has never been reported. The NCT mouse (commonly known as Nakano cataract mouse) has a pink-eyed dilution phenotype, which prompted us to undertake a molecular genetic analysis of the Oca2 gene of this strain. Our genetic linkage analysis suggests that the locus for the pink-eyed dilution phenotype of NCT is tightly linked to the Oca2 locus. PCR cloning and nucleotide sequence analysis indicates that the NCT mouse has a nonsense nucleotide substitution at exon 7 of the Oca2 gene. Examination of three mouse strains (NZW/NSlc, SJL/J, and 129X1/SvJJmsSlc) with the original Oca2(p) allele revealed the presence of a nonsense nucleotide substitution identical to that in the NCT strain. RT-PCR analysis revealed that the Oca2 transcripts were absent in the skin of NCT mice, suggesting intervention of the nonsense-mediated mRNA decay pathway. Collectively, the data in this study indicate that the nonsense nucleotide substitution in the Oca2 gene underlies the Oca2(p) allele. Our data also indicate that the NCT mouse can be used not only as a cataract model, but also as a model for human type II oculocutaneous albinism.

  10. Molecular structure of three mutations at the maize sugary1 locus and their allele-specific phenotypic effects.

    PubMed

    Dinges, J R; Colleoni, C; Myers, A M; James, M G

    2001-03-01

    Starch production in all plants examined is altered by mutations of isoamylase-type starch-debranching enzymes (DBE), although how these proteins affect glucan polymer assembly is not understood. Various allelic mutations in the maize (Zea mays) gene sugary1 (su1), which codes for an isoamylase-type DBE, condition distinct kernel phenotypes. This study characterized the recessive mutations su1-Ref, su1-R4582::Mu1, and su1-st, regarding their molecular basis, chemical phenotypes, and effects on starch metabolizing enzymes. The su1-Ref allele results in two specific amino acid substitutions without affecting the Su1 mRNA level. The su1-R4582::Mu1 mutation is a null allele that abolishes transcript accumulation. The su1-st mutation results from insertion of a novel transposon-like sequence, designated Toad, which causes alternative pre-mRNA splicing. Three su1-st mutant transcripts are produced, one that is nonfunctional and two that code for modified SU1 polypeptides. The su1-st mutation is dominant to the null allele su1-R4582::Mu1, but recessive to su1-Ref, suggestive of complex effects involving quaternary structure of the SU1 enzyme. All three su1- alleles severely reduce or eliminate isoamylase-type DBE activity, although su1-st kernels accumulate less phytoglycogen and Suc than su1-Ref or su1-R4582::Mu1 mutants. The chain length distribution of residual amylopectin is significantly altered by su1-Ref and su1-R4582::Mu1, whereas su1-st has modest effects. These results, together with su1 allele-specific effects on other starch- metabolizing enzymes detected in zymograms, suggest that total DBE catalytic activity is the not the sole determinant of Su1 function and that specific interactions between SU1 and other components of the starch biosynthetic system are required.

  11. Molecular Structure of Three Mutations at the Maize sugary1 Locus and Their Allele-Specific Phenotypic Effects1

    PubMed Central

    Dinges, Jason R.; Colleoni, Christophe; Myers, Alan M.; James, Martha G.

    2001-01-01

    Starch production in all plants examined is altered by mutations of isoamylase-type starch-debranching enzymes (DBE), although how these proteins affect glucan polymer assembly is not understood. Various allelic mutations in the maize (Zea mays) gene sugary1 (su1), which codes for an isoamylase-type DBE, condition distinct kernel phenotypes. This study characterized the recessive mutations su1-Ref, su1-R4582::Mu1, and su1-st, regarding their molecular basis, chemical phenotypes, and effects on starch metabolizing enzymes. The su1-Ref allele results in two specific amino acid substitutions without affecting the Su1 mRNA level. The su1-R4582::Mu1 mutation is a null allele that abolishes transcript accumulation. The su1-st mutation results from insertion of a novel transposon-like sequence, designated Toad, which causes alternative pre-mRNA splicing. Three su1-st mutant transcripts are produced, one that is nonfunctional and two that code for modified SU1 polypeptides. The su1-st mutation is dominant to the null allele su1-R4582::Mu1, but recessive to su1-Ref, suggestive of complex effects involving quaternary structure of the SU1 enzyme. All three su1- alleles severely reduce or eliminate isoamylase-type DBE activity, although su1-st kernels accumulate less phytoglycogen and Suc than su1-Ref or su1-R4582::Mu1 mutants. The chain length distribution of residual amylopectin is significantly altered by su1-Ref and su1-R4582::Mu1, whereas su1-st has modest effects. These results, together with su1 allele-specific effects on other starch- metabolizing enzymes detected in zymograms, suggest that total DBE catalytic activity is the not the sole determinant of Su1 function and that specific interactions between SU1 and other components of the starch biosynthetic system are required. PMID:11244120

  12. Two amino acid substitutions in apolipoprotein B are in complete allelic association with the antigen group (x/y) polymorphism: Evidence for little recombination in the 3' end of the human gene

    PubMed Central

    Dunning, Alison M.; Renges, Helmut-H.; Xu, Chun-Fang; Peacock, Rachel; Brasseur, Robert; Laxer, Gerald; Tikkanen, Matti J.; Bütler, Réné; Saha, N.; Hamsten, Anders; Rosseneu, Maryvonne; Talmud, Philippa; Humphries, Steve E.

    1992-01-01

    We report the identification of an A-to-G base change, in exon 29 of the apolipoprotein B (apo B) gene, that results in the substitution of serine for asparagine at residue 4311 of mature apo B100. In a recent publication, Huang et al. have reported a C-to-T base change in exon 26 that causes the substitution of leucine for proline at residue 2712 of apo B. We have found complete linkage disequilibrium between the alleles at both these sites and an immunochemical polymorphism of LDL designated antigen group (x/y) (Ag(x/y)) in a sample of 118 Finnish individuals. This implies that either one of these substitutions–or both of them combined–could be the molecular basis of the Ag(x/y) antigenic determinants, with the allele encoding serine4311 plus leucine2712 representing the Ag(x) epitope, and that encoding asparagine4311 plus proline2712 the Ag(y) epitope. In a sample of 90 healthy Swedish individuals the Leu2712/Ser4311 allele is associated both with reduced serum levels of LDL-cholesterol and apo B and with raised levels of HDL. However, these differences are of smaller effect than those associated with the XbaI RFLP of the apo B gene in this sample. We have also genotyped 523 individuals from European, Asian, Chinese, and Afro-Caribbean populations and have found complete association between the sites encoding residues 2712 and 4311 in all of these samples, although there are large allele frequency differences between these populations. In addition, there is strong linkage disequilibrium with allelic association between the alleles of these sites and those of the XbaI RFLP in all the populations examined. Taken together, these data suggest that, since the divergence of the major ethnic groups, there has been little or no recombination in the 3' end of the human apo B gene. ImagesFigure 1Figure 2Figure 3 PMID:1370364

  13. Effective marker alleles associated with type 2 resistance to Fusarium head blight infection in fields

    PubMed Central

    Li, Tao; Luo, Meng; Zhang, Dadong; Wu, Di; Li, Lei; Bai, Guihua

    2016-01-01

    Molecular markers associated with known quantitative trait loci (QTLs) for type 2 resistance to Fusarium head blight (FHB) in bi-parental mapping population usually have more than two alleles in breeding populations. Therefore, understanding the association of each allele with FHB response is particularly important to marker-assisted enhancement of FHB resistance. In this paper, we evaluated FHB severities of 192 wheat accessions including landraces and commercial varieties in three field growing seasons, and genotyped this panel with 364 genome-wide informative molecular markers. Among them, 11 markers showed reproducible marker-trait association (p < 0.05) in at least two experiments using a mixed model. More than two alleles were identified per significant marker locus. These alleles were classified into favorable, unfavorable and neutral alleles according to the normalized genotypic values. The distributions of effective alleles at these loci in each wheat accession were characterized. Mean FHB severities increased with decreased number of favorable alleles at the reproducible loci. Chinese wheat landraces and Japanese accessions have more favorable alleles at the majority of the reproducible marker loci. FHB resistance levels of varieties can be greatly improved by introduction of these favorable alleles and removal of unfavorable alleles simultaneously at these QTL-linked marker loci. PMID:27436944

  14. Allele mining in the pepper gene pool provided new complementation effects between pvr2-eIF4E and pvr6-eIF(iso)4E alleles for resistance to pepper veinal mottle virus.

    PubMed

    Rubio, Manuel; Nicolaï, Maryse; Caranta, Carole; Palloix, Alain

    2009-11-01

    Molecular cloning of recessive resistance genes to potyviruses in a large range of host species identified the eukaryotic translation initiation factor 4E (eIF4E) as an essential determinant in the outcome of potyvirus infection. Resistance results from a few amino acid changes in the eIF4E protein encoded by the recessive resistance allele that disrupt the direct interaction with the potyviral protein VPg. In plants, several loci encode two protein subfamilies, eIF4E and eIF(iso)4E. While most eIF4E-mediated resistance to potyviruses depends on mutations in a single eIF4E protein, simultaneous mutations in eIF4E (corresponding to the pvr2 locus) and eIF(iso)4E (corresponding to the pvr6 locus) are required to prevent pepper veinal mottle virus (PVMV) infection in pepper. We used this model to look for additional alleles at the pvr2-eIF4E locus that result in resistance when combined with the pvr6-eIF(iso)4E resistant allele. Among the 12 pvr2-eIF4E resistance alleles sequenced in the pepper gene pool, three were shown to have a complementary effect with pvr6-eIF(iso)4E for resistance. Two amino acid changes were exclusively shared by these three alleles and were systematically associated with a second amino acid change, suggesting that these substitutions are associated with resistance expression. The availability of new resistant allele combinations increases the possibility for the durable deployment of resistance against this pepper virus which is prevalent in Africa.

  15. Generation of humoral immune responses to multi-allele PfAMA1 vaccines; effect of adjuvant and number of component alleles on the breadth of response.

    PubMed

    Kusi, Kwadwo A; Faber, Bart W; Riasat, Vanessa; Thomas, Alan W; Kocken, Clemens H M; Remarque, Edmond J

    2010-11-03

    There is increasing interest in multi-allele vaccines to overcome strain-specificity against polymorphic vaccine targets such as Apical Membrane Antigen 1 (AMA1). These have been shown to induce broad inhibitory antibodies in vitro and formed the basis for the design of three Diversity-Covering (DiCo) proteins with similar immunological effects. The antibodies produced are to epitopes that are shared between vaccine alleles and theoretically, increasing the number of component AMA1 alleles is expected to broaden the antibody response. A plateau effect could however impose a limit on the number of alleles needed to achieve the broadest specificity. Moreover, production cost and the vaccine formulation process would limit the number of component alleles. In this paper, we compare rabbit antibody responses elicited with multi-allele vaccines incorporating seven (three DiCos and four natural AMA1 alleles) and three (DiCo mix) antigens for gains in broadened specificity. We also investigate the effect of three adjuvant platforms on antigen specificity and antibody functionality. Our data confirms a broadened response after immunisation with DiCo mix in all three adjuvants. Higher antibody titres were elicited with either CoVaccine HT™ or Montanide ISA 51, resulting in similar in vitro inhibition (65-82%) of five out of six culture-adapted P. falciparum strains. The antigen binding specificities of elicited antibodies were also similar and independent of the adjuvant used or the number of vaccine component alleles. Thus neither the four extra antigens nor adjuvant had any observable benefits with respect to specificity broadening, although adjuvant choice influenced the absolute antibody levels and thus the extent of parasite inhibition. Our data confirms the feasibility and potential of multi-allele PfAMA1 formulations, and highlights the need for adjuvants with improved antibody potentiation properties for AMA1-based vaccines.

  16. Substitution effects on bismuth based multifunctional materials

    NASA Astrophysics Data System (ADS)

    Krezhov, Kiril; Kovachev, Stefan; Svab, Erzsebet

    Described are our targeted experiments to improve understanding of some key aspects of the mechanisms contributing to intrinsic effects such as the magnetoelectric coupling in oxides. The magnetoelectric materials have long been of interest because of useful combinations of electrical, magnetic, optical and catalytic properties. Particularly spectacular are the manganites(M=Mn) for which apart from the strong magnetoresistance (MR) effect another striking feature is the occurrence of charge and orbital ordering (CO-OO) effects connected with the specific orbital orientation and the spatial arrangement of the eg orbitals. The MR and CO-OO effects are a manifestation of the strong interplay between the orbital, charge, and spin degrees of freedom in these systems and in some cases gives rise to multiferroicity. In this regard, some of our research is on new ABO3, AB2O5 and double perovskites A2BB'O6 containing p elements with lone pair electrons such as Bi3+. Bismuth creates irregular oxygen coordination environment and to stabilize its valence state often requires the use of high pressure or specific soft chemistry. Studied are the effects of cationic substitution on the structural parameters of the perovskites (Bi1-yRy)1-xAxMnO3 (R = rare earth; A= Ca2+, Sr2+; x,y=0.5), BiFexMn2-xO5, La1-xBiXMn2O5 etc. Ab-initio density functional theory calculations were performed to study the structure, magnetic and optical properties of multiferroic BiFeO3, also modified with La3+ and Mn3+. Synthesized and characterized is a new bismuth oxide - multiferroic BiFe2O5-δ A number of studies continue to address this class of materials and related-type materials such as cobaltites, chromites and ferrites, much of the work being driven by the potential applications as electrode materials in solid oxide fuel cells, exhaust gas sensors, membranes for separation processes or as catalysts but lately new functionalities emerge and are in the focus for use in electronics and information

  17. Cationic Gold Clusters Ligated with Differently Substituted Phosphines: Effect of Substitution on Ligand Reactivity and Binding

    SciTech Connect

    Johnson, Grant E.; Olivares, Astrid M.; Hill, David E.; Laskin, Julia

    2015-01-01

    We present a systematic study of the effect of the number of methyl (Me) and cyclohexyl (Cy) functional groups in monodentate phosphine ligands on the solution-phase synthesis of ligated sub-nanometer gold clusters and their gas-phase fragmentation pathways. Small mixed ligand cationic gold clusters were synthesized using ligand exchange reactions between pre-formed triphenylphosphine ligated (PPh3) gold clusters and monodentate Me- and Cy-substituted ligands in solution and characterized using electrospray ionization mass spectrometry (ESI-MS) and collision-induced dissociation (CID) experiments. Under the same experimental conditions, larger gold-PPh3 clusters undergo efficient exchange of unsubstituted PPh3 ligands for singly Me- and Cy-substituted PPh2Me and PPh2Cy ligands. The efficiency of ligand exchange decreases with an increasing number of Me or Cy groups in the substituted phosphine ligands. CID experiments performed for a series of ligand-exchanged gold clusters indicate that loss of a neutral Me-substituted ligand is preferred over loss of a neutral PPh¬3 ligand while the opposite trend is observed for Cy-substituted ligands. The branching ratio of the competing ligand loss channels is strongly correlated with the electron donating ability of the phosphorous lone pair as determined by the relative proton affinity of the ligand. The results indicate that the relative ligand binding energies increase in the order PMe3 < PPhMe2 < PPh2Me < PPh3< PPh2Cy < PPhCy2< PCy3. Furthermore, the difference in relative ligand binding energies increases with the number of substituted PPh3-mMem or PPh3-mCym ligands (L) exchanged onto each cluster. This study provides the first experimental determination of the relative binding energies of ligated gold clusters containing differently substituted monophosphine ligands, which are important to controlling their synthesis and reactivity in solution. The results also indicate that ligand substitution is an important

  18. Carriage of One or Two FMR1 Premutation Alleles Seems to Have No Effect on Illness Severity in a FXTAS Female with an Autozygous FMR1 Premutation Allele.

    PubMed

    Rodriguez-Revenga, Laia; Pagonabarraga, Javier; Gómez-Anson, Beatriz; López-Mourelo, Olga; Izquierdo, Silvia; Alvarez-Mora, Maria Isabel; Granell, Esther; Madrigal, Irene; Milà, Montserrat

    2016-10-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that occurs in FMR1 premutation carriers. The prevalence of FMR1 premutation carriers in the general population is relatively high, and although rare, a premutation in both X chromosomes may occur in females inheriting a premutation allele from each of both parent carriers. Here, we report the first female with an autozygous (homozygous by descendent) FMR1 premutation allele, who fulfills neurological and radiological FXTAS findings/criteria. Molecular characterization included CGG repeat length, AGG interruption pattern, FMR1 messenger RNA (mRNA), fragile X mental retardation protein (FMRP) level quantification, and single-nucleotide polymorphism (SNP) microarray. Neuroradiological assessment of 3-T magnetic resonance imaging and neurological and cognitive/neuropsychological evaluations were performed. Neurological and neuroradiological examination of the female with the same FMR1 allele in the premutation range (77 CGGs) demonstrated FXTAS features. Further familial evaluation showed a similar neuropsychiatric profile, with impairments in cognitive flexibility and visuospatial function, mainly. A unique family with an autozygous FMR1 premutation female is presented. Neurological/cognitive and neuroradiological examinations revealed FXTAS-specific findings in the female with the autozygous FMR1 premutation allele. The consistent molecular and cognitive/psychiatric phenotype in family members suggests that carrying one or two FMR1 premutation alleles has no effect on illness severity.

  19. JAK2 Allele Burden in the Myeloproliferative Neoplasms: Effects on Phenotype, Prognosis and Change with Treatment

    PubMed Central

    Vannucchi, Alessandro M.; Pieri, Lisa; Guglielmelli, Paola

    2011-01-01

    The field of Philadelphia-chromosome-negative chronic myeloproliferative neoplasms (MPNs) has recently witnessed tremendous advances in the basic knowledge of disease pathophysiology that followed the identification of mutations in JAK2 and MPL. These discoveries led to a revision of the criteria employed for diagnosis by the World Health Organization. The prognostic role of the JAK2V617F mutation and of its allelic burden has been the objective of intensive research using a variety of cellular and animal models as well as in large series of patients. While a definitive position cannot yet been taken on all of the issues, there is a consensus that the presence of higher V617F allele burden, that is on the basis of a stronger activation of intracellular signalling pathways, is associated with the clinical phenotype of polycythemia vera and with defined haematological and clinical markers indicative of a more aggressive phenotype. On the other hand, a low allele burden in myelofibrosis is associated with reduced survival. Finally, a significant reduction of JAK2 V617F allele burden has been demonstrated in patients treated with interferon, while the effects of novel JAK1 and JAK2 inhibitors have not yet been fully ascertained. PMID:23556073

  20. Phenotypic effects of an allele causing obligate parthenogenesis in a rotifer.

    PubMed

    Scheuerl, Thomas; Riss, Simone; Stelzer, Claus-Peter

    2011-01-01

    Transitions to obligate asexuality have been documented in almost all metazoan taxa, yet the conditions favoring such transitions remained largely unexplored. We address this problem in the rotifer Brachionus calyciflorus. In this species, a polymorphism at a single locus, op, can result in transitions to obligate parthenogenesis. Homozygotes for the op allele reproduce strictly by asexual reproduction, whereas heterozygous clones (+/op) and wild-type clones (+/+) are cyclical parthenogens that undergo sexual reproduction at high population densities. Here, we examine dosage effects of the op allele by analyzing various life-history characteristics and population traits in 10 clones for each of the 3 possible genotypes (op/op, +/op, and +/+). For most traits, we found that op/op clones differed significantly (P < 0.05) from the 2 cyclical parthenogenetic genotypes (+/+ and +/op). By contrast, the 2 cyclical parthenogenetic genotypes were almost indistinguishable, except that heterozygote individuals were slightly but significantly smaller in body size compared with wild-type individuals. Overall, this indicates that the op allele is selectively neutral in the heterozygous state. Thus, selective sweeps of this allele in natural populations would first require conditions favoring the generation of homozygotes. This may be given by inbreeding in very small populations or by double mutants in very large populations.

  1. Estimating the Effective Population Size from Temporal Allele Frequency Changes in Experimental Evolution

    PubMed Central

    Jónás, Ágnes; Taus, Thomas; Kosiol, Carolin; Schlötterer, Christian; Futschik, Andreas

    2016-01-01

    The effective population size (Ne) is a major factor determining allele frequency changes in natural and experimental populations. Temporal methods provide a powerful and simple approach to estimate short-term Ne. They use allele frequency shifts between temporal samples to calculate the standardized variance, which is directly related to Ne. Here we focus on experimental evolution studies that often rely on repeated sequencing of samples in pools (Pool-seq). Pool-seq is cost-effective and often outperforms individual-based sequencing in estimating allele frequencies, but it is associated with atypical sampling properties: Additional to sampling individuals, sequencing DNA in pools leads to a second round of sampling, which increases the variance of allele frequency estimates. We propose a new estimator of Ne, which relies on allele frequency changes in temporal data and corrects for the variance in both sampling steps. In simulations, we obtain accurate Ne estimates, as long as the drift variance is not too small compared to the sampling and sequencing variance. In addition to genome-wide Ne estimates, we extend our method using a recursive partitioning approach to estimate Ne locally along the chromosome. Since the type I error is controlled, our method permits the identification of genomic regions that differ significantly in their Ne estimates. We present an application to Pool-seq data from experimental evolution with Drosophila and provide recommendations for whole-genome data. The estimator is computationally efficient and available as an R package at https://github.com/ThomasTaus/Nest. PMID:27542959

  2. Divergent allele advantage at MHC-DRB through direct and maternal genotypic effects and its consequences for allele pool composition and mating.

    PubMed

    Lenz, Tobias L; Mueller, Birte; Trillmich, Fritz; Wolf, Jochen B W

    2013-07-07

    It is still debated whether main individual fitness differences in natural populations can be attributed to genome-wide effects or to particular loci of outstanding functional importance such as the major histocompatibility complex (MHC). In a long-term monitoring project on Galápagos sea lions (Zalophus wollebaeki), we collected comprehensive fitness and mating data for a total of 506 individuals. Controlling for genome-wide inbreeding, we find strong associations between the MHC locus and nearly all fitness traits. The effect was mainly attributable to MHC sequence divergence and could be decomposed into contributions of own and maternal genotypes. In consequence, the population seems to have evolved a pool of highly divergent alleles conveying near-optimal MHC divergence even by random mating. Our results demonstrate that a single locus can significantly contribute to fitness in the wild and provide conclusive evidence for the 'divergent allele advantage' hypothesis, a special form of balancing selection with interesting evolutionary implications.

  3. Effects of antibiotic resistance alleles on bacterial evolutionary responses to viral parasites.

    PubMed

    Arias-Sánchez, Flor I; Hall, Alex R

    2016-05-01

    Antibiotic resistance has wide-ranging effects on bacterial phenotypes and evolution. However, the influence of antibiotic resistance on bacterial responses to parasitic viruses remains unclear, despite the ubiquity of such viruses in nature and current interest in therapeutic applications. We experimentally investigated this by exposing various Escherichia coli genotypes, including eight antibiotic-resistant genotypes and a mutator, to different viruses (lytic bacteriophages). Across 960 populations, we measured changes in population density and sensitivity to viruses, and tested whether variation among bacterial genotypes was explained by their relative growth in the absence of parasites, or mutation rate towards phage resistance measured by fluctuation tests for each phage. We found that antibiotic resistance had relatively weak effects on adaptation to phages, although some antibiotic-resistance alleles impeded the evolution of resistance to phages via growth costs. By contrast, a mutator allele, often found in antibiotic-resistant lineages in pathogenic populations, had a relatively large positive effect on phage-resistance evolution and population density under parasitism. This suggests costs of antibiotic resistance may modify the outcome of phage therapy against pathogenic populations previously exposed to antibiotics, but the effects of any co-occurring mutator alleles are likely to be stronger.

  4. Short Alleles, Bigger Smiles? The Effect of 5-HTTLPR on Positive Emotional Expressions

    PubMed Central

    Haase, Claudia M.; Beermann, Ursula; Saslow, Laura R.; Shiota, Michelle N.; Saturn, Sarina R.; Lwi, Sandy J.; Casey, James J.; Nguyen, Nguyen K.; Whalen, Patrick K.; Keltner, Dacher J.; Levenson, Robert W.

    2015-01-01

    The present research examined the effect of the 5-HTTLPR polymorphism in the serotonin transporter gene on objectively coded positive emotional expressions (i.e., laughing and smiling behavior objectively coded using the Facial Action Coding System). Three studies with independent samples of participants were conducted. Study 1 examined young adults watching still cartoons. Study 2 examined young, middle-aged, and older adults watching a thematically ambiguous yet subtly amusing film clip. Study 3 examined middle-aged and older spouses discussing an area of marital conflict (which typically produces both positive and negative emotion). Aggregating data across studies, results showed that the short allele of 5-HTTLPR predicted heightened positive emotional expressions. Results remained stable when controlling for age, gender, ethnicity, and depressive symptoms. These findings are consistent with the notion that the short allele of 5-HTTLPR functions as an emotion amplifier, which may confer heightened susceptibility to environmental conditions. PMID:26029940

  5. Chromosome substitution lines (CS-B) revealed the presence of cryptic beneficial alleles in G. barbadense with potential to increase lint and seedcotton yield in Upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most promising opportunities to improve the genetic diversity of Upland cotton is from interspecific germplasm introgression from the other tetraploid species. The untapped potential of the beneficial alleles of the wild unadapted species has not been well utilized because of the paucit...

  6. Effects of alkyl substitutions of xanthine skeleton on bronchodilation.

    PubMed

    Sakai, R; Konno, K; Yamamoto, Y; Sanae, F; Takagi, K; Hasegawa, T; Iwasaki, N; Kakiuchi, M; Kato, H; Miyamoto, K

    1992-10-30

    Structure-activity relationships in a series of 1,3,7-trialkyl-xanthine were studied with guinea pigs. Relaxant actions in the tracheal muscle were increased with alkyl chain length at the 1- and 3-positions of the xanthine skeleton, but decreased by alkylation at the 7-position. Positive chronotropic actions in the right atrium were potentiated with 3-alkyl chain length but tended to decrease with 1-alkylation and diminish by 7-substitution. Consequently, while the 1- and 3-substitutions were equally important for the tracheal smooth muscle relaxation, the substitution at the 1-position was more important than the 3-substitution for bronchoselectivity. The 7-alkylation may be significant to cancel heart stimulation. There were good correlations between the smooth muscle relaxant action and the cyclic AMP-PDE inhibitory activity in 3-substituents and the affinity for adenosine (A1) receptors in 1-, 3-, and 7-substituents. This suggests that not only the cyclic AMP-PDE inhibitory activity but also the adenosine antagonistic activity is important in the bronchodilatory effects of alkylxanthines. Among these xanthine derivatives, 1-butyl-3-propylxanthine and its 7-methylated derivative showed high bronchoselectivity in the in vitro and in vivo experiments compared to theophylline and enprofylline and may be new candidates for bronchodilator.

  7. Diverse Non-genetic, Allele-Specific Expression Effects Shape Genetic Architecture at the Cellular Level in the Mammalian Brain.

    PubMed

    Huang, Wei-Chao; Ferris, Elliott; Cheng, Tong; Hörndli, Cornelia Stacher; Gleason, Kelly; Tamminga, Carol; Wagner, Janice D; Boucher, Kenneth M; Christian, Jan L; Gregg, Christopher

    2017-03-08

    Interactions between genetic and epigenetic effects shape brain function, behavior, and the risk for mental illness. Random X inactivation and genomic imprinting are epigenetic allelic effects that are well known to influence genetic architecture and disease risk. Less is known about the nature, prevalence, and conservation of other potential epigenetic allelic effects in vivo in the mouse and primate brain. Here we devise genomics, in situ hybridization, and mouse genetics strategies to uncover diverse allelic effects in the brain that are not caused by imprinting or genetic variation. We found allelic effects that are developmental stage and cell type specific, that are prevalent in the neonatal brain, and that cause mosaics of monoallelic brain cells that differentially express wild-type and mutant alleles for heterozygous mutations. Finally, we show that diverse non-genetic allelic effects that impact mental illness risk genes exist in the macaque and human brain. Our findings have potential implications for mammalian brain genetics. VIDEO ABSTRACT.

  8. Effects of antimony substitution on bismuth based superconductors

    NASA Technical Reports Server (NTRS)

    Barrientos, Alfonso

    1990-01-01

    The effect of Sb substitution and simultaneous substitution of Pb and Sb on the superconducting transition temperatures in the BiSrCaCuO system is investigated. The 2:2:2:3 phase is of particular interest since any small increase in the transition temperature could be of great interest. More that 90 different samples were prepared based on 2:2:2:3 stoichiometry in the BiSrCaCuO system. After this preliminary attempt, four different families of samples were investigated. In the first family of samples, Bi was substituted by Sb to form Bi(1.9)Sb(0.1)Sr2Ca2Cu3O(y). The second group of samples were prepared by simultaneous addition of Pb and Sb with nominal composition Bi(1.8)Pb(0.1)Sb(0.1)Sr2Ca2Cu3O(y). The third and fourth groups were prepared to determine the effect created when the Pb concentration is increased with the nominal compositions being Bi(1.7)Pb(0.1)Sr2Ca2Cu3O(y) and Bi(1.6)Sb(0.1)Sr2Ca2Cu3O(y). The results of these investigations are presented with a discussion.

  9. Plasma protein loss during surgery: beneficial effects of albumin substitution.

    PubMed

    Horstick, G; Lauterbach, M; Kempf, T; Ossendorf, M; Kopacz, L; Heimann, A; Lehr, H A; Bhakdi, S; Horstick, M; Meyer, J; Kempski, O

    2001-07-01

    Plasma protein loss during abdominal surgery is a known phenomenon, but its possible pathophysiological relevance has remained unknown. The present study evaluates the effects of albumin substitution on systemic and local hemodynamics and cellular interactions in the mesenteric microcirculation. Rats underwent median laparotomy and exteriorization of an ileal loop for intravital microscopy of the mesenteric microcirculation. Plasma protein concentrations, systemic and local hemodynamics were recorded during the follow up period, with or without albumin substitution. Depending on the time course of plasma protein loss in control experiments, 80% of the calculated protein loss was infused during the first 2 h of surgery, and the other 20% over the following 5 h of intravital microscopy. The control group received a continuous infusion of normal saline. Plasma protein loss was mainly due to loss of albumin. A significant increase in adherent and rolling leukocytes was observed during the course of mesenteric exteriorization, which was almost entirely reversed by albumin replacement. Albumin substitution led to stabilisation of mean arterial pressure and abdominal blood flow and also attenuated reductions in arterial base excess. Albumin infusions to replace plasma protein loss may be a simple and effective measure to attenuate microcirculatory disturbances and may be of benefit in patients undergoing abdominal surgery.

  10. Divergent allele advantage at MHC-DRB through direct and maternal genotypic effects and its consequences for allele pool composition and mating

    PubMed Central

    Lenz, Tobias L.; Mueller, Birte; Trillmich, Fritz; Wolf, Jochen B. W.

    2013-01-01

    It is still debated whether main individual fitness differences in natural populations can be attributed to genome-wide effects or to particular loci of outstanding functional importance such as the major histocompatibility complex (MHC). In a long-term monitoring project on Galápagos sea lions (Zalophus wollebaeki), we collected comprehensive fitness and mating data for a total of 506 individuals. Controlling for genome-wide inbreeding, we find strong associations between the MHC locus and nearly all fitness traits. The effect was mainly attributable to MHC sequence divergence and could be decomposed into contributions of own and maternal genotypes. In consequence, the population seems to have evolved a pool of highly divergent alleles conveying near-optimal MHC divergence even by random mating. Our results demonstrate that a single locus can significantly contribute to fitness in the wild and provide conclusive evidence for the ‘divergent allele advantage’ hypothesis, a special form of balancing selection with interesting evolutionary implications. PMID:23677346

  11. Combined Effects of GSTM1 Null Allele and APOL1 Renal Risk Alleles in CKD Progression in the African American Study of Kidney Disease and Hypertension Trial.

    PubMed

    Bodonyi-Kovacs, Gabor; Ma, Jennie Z; Chang, Jamison; Lipkowitz, Michael S; Kopp, Jeffrey B; Winkler, Cheryl Ann; Le, Thu H

    2016-10-01

    Apolipoprotein L-1 (APOL1) high-risk alleles and the glutathione-S-transferase-μ1 (GSTM1) null allele have been shown separately to associate with CKD progression in the African American Study of Kidney Disease and Hypertension (AASK) trial participants. Here, we determined combined effects of GSTM1 null and APOL1 high-risk alleles on clinical outcomes in 682 AASK participants who were classified into four groups by GSTM1 null or active genotype and APOL1 high- or low-risk genotype. We assessed survival differences among these groups by log-rank test and Cox regression adjusted for important clinical variables for time to GFR event (change in GFR of 50% or 25-ml/min per 1.73 m(2) decline), incident ESRD, death, or composite outcomes. The groups differed significantly in event-free survival for incident ESRD and composite outcomes (P≤0.001 by log-rank test). Compared with the reference GSTM1 active/APOL1 low-risk group, other groups had these hazard ratios for the composite outcome of incident ESRD and change in GFR: GSTM1 active/APOL1 high-risk hazard ratio, 2.13; 95% confidence interval, 0.76 to 5.90 (P=0.15); GSTM1 null/APOL1 low-risk hazard ratio, 2.05; 95% confidence interval, 1.08 to 3.88 (P=0.03); and GSTM1 null/APOL1 high-risk hazard ratio, 3.0; 95% confidence interval, 1.51 to 5.96 (P=0.002). In conclusion, GSTM1 null and APOL1 high-risk alleles deleteriously affect CKD progression among blacks with hypertension, and subjects with both GSTM1 null and APOL1 high-risk genotypes had highest risk of adverse renal outcomes. Larger cohorts are needed to fully explore interactions of GSTM1 and APOL1 genotypes in other subgroups.

  12. Price and welfare effects of a pharmaceutical substitution reform.

    PubMed

    Granlund, David

    2010-12-01

    The price effects of the Swedish pharmaceutical substitution reform are analyzed using data for a panel of all pharmaceutical product sold in Sweden in 1997-2007. The price reduction due to the reform was estimated to average 10% and was found to be significantly larger for brand-name pharmaceuticals than for generics. The results also imply that the reform amplified the effect that generic entry has on brand-name prices by a factor of 10. Results of a demand estimation imply that the price reductions increased total pharmaceutical consumption by 8% and consumer welfare by SEK 2.7 billion annually.

  13. Substitution of Aspartate for glycine 1018 in the Type III procollagen (COL3AI) gene causes type IV Ehlers-Danlos Syndrome: The mutated allele is present in most blood leukocytes of the asymptomatic and mosaic mother

    SciTech Connect

    Kontusaari, S.; Tromp, G.; Kuivaniemi, H.; Prockop, D.J. ); Stolle, C. ); Pope, F.M.

    1992-09-01

    A proband with arterial ruptures and skin changes characteristic of the type IV variant of Ehlers-Danlos syndrome was found to have a single-base mutation in the type III procollagen gene, which converted the codon for glycine at amino position 1018 to a codon for aspartate. (Amino acid positions are numbered by the standard convention in which the first glycine of the triple-helical domain of an [alpha] chain is number 1. The numbers of positions in the [alpha]1(III) chains can be converted to positions in the human pro[alpha](III) chain by adding 167.). Nucleotide sequencing of overlapping PCR products in which the two alleles were distinguished demonstrated that the mutation of glycine 1018 was the only mutation that changed the primary structure of type III procollagen. The glycine substitution markedly decreased the amount of type III procollagen secreted into the medium by cultured skin fibroblasts from the proband. It is surprising that the same mutation was found in about 94% of the peripheral blood leukocytes from the proband's asymptomatic 72-year-old mother. Other tissues from the mother contained the mutated allele; it was present in 0%-100% of different samples of hair cells and in about 40% of cells from the oral epithelium. Therefore, the mother was a mosaic for the mutation. Since the mutated allele was present in cells derived from all three germ layers, the results indicated that the mutation arose by the late blastocyst stage of development. The results also indicate that assays of blood leukocytes do not always reveal mosaicism or predict phenotypic involvement of tissues, such as blood vessels, that are derived from the same embryonic cells as are leukocytes. 66 refs., 6 figs., 1 tab.

  14. Health-protective and Adverse Effects of the Apolipoprotein E ε2 Allele in Older Males

    PubMed Central

    Kulminski, Alexander M.; Ukraintseva, Svetlana V.; Arbeev, Konstantin G.; Manton, Kenneth G.; Oshima, Junko; Martin, George M.; Il'yasova, Dora; Yashin, Anatoli I.

    2009-01-01

    OBJECTIVES: To re-examine a health-protective role of the common Apolipoprotein E (APOE) polymorphism focusing on connections between the APOE ε2-containing genotypes and impairments in instrumental activities of daily living [IADL] in older (65+) males and females. To examine how these connections may be mediated by diagnosed coronary heart disease (CHD), Alzheimer's disease, colorectal cancer, macular degeneration (MD), and atherosclerosis. DESIGN: Retrospective cross-sectional study. SETTING: The unique disability-focused data from a genetic sub-sample of the 1999 National Long Term Care Survey linked with Medicare service use files. PARTICIPANTS: 1733 genotyped individuals interviewed on IADL disabilities. MEASUREMENTS: Indicators of IADL impairments, five geriatric disorders, and ε2-containing genotypes. RESULTS: The ε2/3 genotype is a major contributor to adverse associations between the ε2 allele and IADL disability in males [Odds Ratio (OR)=3.09, Confidence Interval (CI)=1.53-6.26)]. It shows, however, significant protective effects for CHD (OR=0.55, CI=0.33-0.92), while CHD is adversely associated with IADL disability (OR=2.18, CI=1.28-3.72). The presence of five diseases does not significantly alter the adverse association between ε2-containing genotypes and disability. Protective effects of the ε2/3 genotype for CHD (OR=0.52, CI=0.27-0.99) and deleterious effects for IADL (OR=3.50, CI=1.71-7.14) for males hold in multivariate models with both these factors included. No significant associations between the ε2-containing genotypes and IADL are found in females. CONCLUSIONS: The ε2 allele can play a dual role in males, protecting them against some health disorders, while promoting others. Strong adverse relationships with disability suggest that ε2-containing genotypes can be unfavorable factors for the health/well-being of aging males. PMID:18179501

  15. The Rpe65rd12 Allele Exerts a Semidominant Negative Effect on Vision in Mice

    PubMed Central

    Wright, Charles B.; Chrenek, Micah A.; Feng, Wei; Getz, Shannon E.; Duncan, Todd; Pardue, Machelle T.; Feng, Yue; Redmond, T. Michael; Boatright, Jeffrey H.; Nickerson, John M.

    2014-01-01

    Purpose. The rd12 mouse was reported as a recessively inherited Rpe65 mutation. We asked if the rd12 mutation resides in Rpe65 and how the mutation manifests itself. Methods. A complementation test was performed by mating Rpe65KO (KO/KO) and rd12 mice together to determine if the rd12 mutation is in the Rpe65 gene. Visual function of wild-type (+/+), KO/+, rd12/+, KO/KO, rd12/rd12, and KO/rd12 mice was measured by optokinetic tracking (OKT) and ERG. Morphology was assessed by retinal cross section. qRT-PCR quantified Rpe65 mRNA levels. Immunoblotting measured the size and level of RPE65 protein. Rpe65 mRNA localization was visualized with RNA fluorescence in situ hybridization (FISH). Fractions of Rpe65 mRNA-bound proteins were separated by linear sucrose gradient fractionation. Results. The KO and rd12 alleles did not complement. The rd12 allele induced a negative semidominant effect on visual function; OKT responses became undetectable 120 days earlier in rd12/rd12 mice compared with KO/KO mice. rd12/+ mice lost approximately 21% visual acuity by P210. rd12/rd12 mice had fewer cone photoreceptor nuclei than KO/KO mice at P60. rd12/rd12 mice expressed 71% +/+ levels of Rpe65 mRNA, but protein was undetectable. Mutant mRNA was appropriately spliced, exported to the cytoplasm, trafficked, and contained no other coding mutation aside from the known nonsense mutation. Mutant mRNA was enriched on ribosome-free messenger ribonucleoproteins (mRNPs), whereas wild-type mRNA was enriched on actively translating polyribosomes. Conclusions. The rd12 lesion is in Rpe65. The rd12 mutant phenotype inherits in a semidominant manner. The effects of the mutant mRNA on visual function may result from inefficient binding to ribosomes for translation. PMID:24644049

  16. The effect of wild card designations and rare alleles in forensic DNA database searches.

    PubMed

    Tvedebrink, Torben; Bright, Jo-Anne; Buckleton, John S; Curran, James M; Morling, Niels

    2015-05-01

    Forensic DNA databases are powerful tools used for the identification of persons of interest in criminal investigations. Typically, they consist of two parts: (1) a database containing DNA profiles of known individuals and (2) a database of DNA profiles associated with crime scenes. The risk of adventitious or chance matches between crimes and innocent people increases as the number of profiles within a database grows and more data is shared between various forensic DNA databases, e.g. from different jurisdictions. The DNA profiles obtained from crime scenes are often partial because crime samples may be compromised in quantity or quality. When an individual's profile cannot be resolved from a DNA mixture, ambiguity is introduced. A wild card, F, may be used in place of an allele that has dropped out or when an ambiguous profile is resolved from a DNA mixture. Variant alleles that do not correspond to any marker in the allelic ladder or appear above or below the extent of the allelic ladder range are assigned the allele designation R for rare allele. R alleles are position specific with respect to the observed/unambiguous allele. The F and R designations are made when the exact genotype has not been determined. The F and R designation are treated as wild cards for searching, which results in increased chance of adventitious matches. We investigated the probability of adventitious matches given these two types of wild cards.

  17. Identification of a cys-ser substitution in the 5-HT{sub 2C} (HTR2C) receptor gene and allelic association to violent behavior and alcoholism

    SciTech Connect

    Lappalainen, J.; Ozaki, N.; Goldman, D.

    1994-09-01

    Several lines of evidence suggest that brain serotonergic functions, including behavioral and neurochemical responses to 5-HT{sub 2C} agonist, are abnormal in some individuals with alcoholism and aggressive behaviors. The aim of the present study was to identify coding sequence variants in the human 5-HT{sub 2C} receptor gene which may cause abnormal or variant function of this receptor. Using SSCP analysis, a non-conservative cys-ser substitution was found in the 5-HT{sub 2C} receptor (designated 5-HT{sub 2Ccys} and 5-HT{sub 2Cser}). The polymorphism was typed in CEPH families to genetically map the gene. To test for association of the variant to alcoholism, violent behavior and serotonin function, the 5-HT{sub 2C} genotypes of 151 non-related Finnish male alcoholic violent offenders and impulsive fire setters and 127 Finnish psychiatrically interviewed healthy male volunteers were determined. CSF 5-HIAA concentrations were available for 74 alcoholic violent offenders and 25 healthy volunteers. Linkage analysis placed the 5-HT{sub 2C} gene on Xq21, a region that has been previously shown to contain genes for several mental retardation syndromes. The 5-HT{sub 2Ccys}/5-HT{sub 2Cser} genotype frequencies in alcoholic violent offenders and controls differed significantly (0.90/0.10 and 0.82/0.18, respectively, P=0.048). The association was found to be strongest in the violent offenders who did not fulfill the criteria for antisocial personality disorder (5-HT{sub 2Ccys}/5-HT{sub 2Cser} 0.93/0.07, p=0.021). No association was found between CSF 5-HIAA concentrations and 5-HT{sub 2C} genotype. These results implicate a 5-HT{sub 2C} receptor amino acid substitution in predisposition to alcohol abuse and violent behavior in a subgroup of alcoholics.

  18. Ten novel HLA-DRB1 alleles and one novel DRB3 allele.

    PubMed

    Lazaro, A M; Steiner, N K; Moraes, M E; Moraes, J R; Ng, J; Hartzman, R J; Hurley, C K

    2005-10-01

    Ten novel HLA-DRB1 and one DRB3 alleles are described. Eight of the variants are single-nucleotide substitutions, four resulting in an amino acid change (DRB1*1145, *1148, *0828 and *1514) and four with silent substitutions (DRB1*040504, *130103, *160502 and DRB3*020204). Two alleles differ by two nucleotide changes altering one (DRB1*1447 and *1361) amino acid and one allele alters three nucleotides and two amino acids.

  19. Effects of hospital generic drug substitution on diabetes therapy

    PubMed Central

    Chen, Hui-Yin; Chang, Hui-Ru; Lang, Hui-Chu

    2014-01-01

    Objectives To evaluate the effects on physicians’ prescribing behavior and on the therapeutic outcome of non-insulin-dependent diabetes patients of substituting different generic brands of metformin. Methods We adopt a retrospective cohort study involving 280 type-2 diabetes patients who regularly used the outpatient services of one medical center and who had changed metformin brands five times between 2003 and 2008. The aim was to examine the effects of switching brands. The generalized estimating equation was used to determine whether drug brand switching affected patient glycated hemoglobin A1c (HbA1c) levels, their prescribed daily dose, or their adherence to medication with metformin. Results HbA1c levels increased from 7.91 to 8.34 throughout the study period, although it was found that brand switching did not adversely affect HbA1c levels after controlling for patient characteristics and the time course of the study. Furthermore, the prescribed daily dose of metformin was stable throughout the study period, and was approximately 0.8 of the defined daily dose. Finally, although adherence was significantly higher with the original metformin than with the four generic brands, patients still maintained high levels of adherence of >0.8. Conclusion Although switching between different brands of metformin slightly affected the prescribing behavior of the physicians, there was no unfavorable effect on patient HbA1c levels. Thus, the policy of substituting between different generic brands of metformin is a good cost-effective approach that does not adversely affect the quality of diabetes patient care. PMID:24511228

  20. Asynchronous Replication, Mono-Allelic Expression, and Long Range Cis-Effects of ASAR6

    PubMed Central

    Smith, Leslie; Montagna, Christina; Thayer, Mathew J.

    2013-01-01

    Mammalian chromosomes initiate DNA replication at multiple sites along their length during each S phase following a temporal replication program. The majority of genes on homologous chromosomes replicate synchronously. However, mono-allelically expressed genes such as imprinted genes, allelically excluded genes, and genes on female X chromosomes replicate asynchronously. We have identified a cis-acting locus on human chromosome 6 that controls this replication-timing program. This locus encodes a large intergenic non-coding RNA gene named Asynchronous replication and Autosomal RNA on chromosome 6, or ASAR6. Disruption of ASAR6 results in delayed replication, delayed mitotic chromosome condensation, and activation of the previously silent alleles of mono-allelic genes on chromosome 6. The ASAR6 gene resides within an ∼1.2 megabase domain of asynchronously replicating DNA that is coordinated with other random asynchronously replicating loci along chromosome 6. In contrast to other nearby mono-allelic genes, ASAR6 RNA is expressed from the later-replicating allele. ASAR6 RNA is synthesized by RNA Polymerase II, is not polyadenlyated, is restricted to the nucleus, and is subject to random mono-allelic expression. Disruption of ASAR6 leads to the formation of bridged chromosomes, micronuclei, and structural instability of chromosome 6. Finally, ectopic integration of cloned genomic DNA containing ASAR6 causes delayed replication of entire mouse chromosomes. PMID:23593023

  1. Effect of HLA-DPA1 alleles on chronic hepatitis B prognosis and treatment response

    PubMed Central

    Katrinli, Seyma; Enc, Feruze Yilmaz; Ozdil, Kamil; Ozturk, Oguzhan; Tuncer, Ilyas; Doganay, Gizem Dinler; Doganay, Levent

    2016-01-01

    OBJECTIVE: Chronic hepatitis B (CHB) is a major health problem. The outcome of hepatitis B virus (HBV) infection is associated with variations in HLA-DPA1 alleles. The aim of this study was to investigate possible associations of HLA-DPA1 alleles with treatment response and with hepatitis B virus e antigen (HBeAg) seroconversion. METHODS: Eight different HLA-DPA1 alleles from 246 CHB patients were genotyped by polymerase chain reaction with sequence-specific primers at high resolution to investigate the association of HLA-DPA1 alleles with treatment response, development of cirrhosis, HBeAg seroconversion, and disease reoccurrence upon HBeAg loss. RESULTS: There was no significant association between HLA-DPA1 alleles and treatment response, development of cirrhosis, or HBeAg seroconversion. However, HLA-DPA1*04:01 allele was significantly more frequently found in patients who redeveloped disease upon HBeAg seroconversion (100% vs 36.8%: p=0.037; Fisher’s exact test). CONCLUSION: HLA-DPA1*04:01 allele may be a risk factor for reoccurrence of CHB after HBeAg seroconversion. PMID:28275747

  2. Substitution Effects and Linear Free Energy Relationships During Reduction of 4- Benzoyl-n-(4-substituted Benzyl)pyridinium Cations

    NASA Technical Reports Server (NTRS)

    Leventis, Nicholas; Zhang, Guo-Hui; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Chariklia; Gray, Hugh R. (Technical Monitor)

    2003-01-01

    In analogy to 4-(para-substituted benzoyl)-N-methylpyridinium cations (1-X's), the title species (2-X's, -X = -OCH3, -CH3, -H, -Br, -COCH3, -NO2) undergo two reversible, well-separated (E(sub 1/2) greater than or equal to 650 mV) one-electron reductions. The effect of substitution on the reduction potentials of 2-X's is much weaker than the effect of the same substituents on 1-X's: the Hammett rho-values are 0.80 and 0.93 for the 1st- and 2nd-e reduction of 2-X's vs. 2.3 and 3.3 for the same reductions of 1-X's, respectively. Importantly, the nitro group of 2-NO2 undergoes reduction before the 2nd-e reduction of the 4-benzoylpyridinium system. These results suggest that the redox potentials of the 4-benzoylpyridinium system can be course-tuned via p-benzoyl substitution and fine-tuned via para-benzyl substitution. Introducing the recently derived substituent constant of the -NO2(sup)- group (sigma para-NO2(sup)- = -0.97) yields an excellent correlation for the 3rd-e reduction of 2- NO2 (corresponding to the reduction of the carbonyl group) with the 2nd-e reduction of the other 2-X's, and confirms the electron donating properties of -NO2(sup)-.

  3. Substitution Effects on MgB2 Superconductivity

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Zhao, Yuan; Yi, Lin

    2008-02-01

    With the help of supercell method, the first-principle calculations were performed for the study of doping crystal Mg1-xAlxB2 and Mg(B1-yCy)2. Analyzing the variations of the charge distribution and the partial densities of states, we found that the compounds with doping Al to MgB2 compound and/or replacing boron by carbon exhibit new covalent bond effects and unexpected electronic properties, related to superconductivity. The study of the density of states indicates that superconductivity decreases with the increase of Al fraction and carbon concentration. There exists a transition of superconductor to non-superconductor with the change of Al doping fraction. The substitution of boron by carbon results in the decrease of the transition temperature since the decrease of the electron concentration and the lattice constant. The theoretical predictions agree with experimental observations.

  4. Investigating the relationship between FMR1 allele length and cognitive ability in children: a subtle effect of the normal allele range on the normal ability range?

    PubMed

    Loat, C S; Craig, G; Plomin, R; Craig, I W

    2006-09-01

    The FMR1 gene contains a trinucleotide repeat tract which can expand from a normal size of around 30 repeats to over 200 repeats, causing mental retardation (Fragile X Syndrome). Evidence suggests that premutation males (55-200 repeats) are susceptible to a late-onset tremor/ataxia syndrome and females to premature ovarian failure, and that intermediate alleles ( approximately 41-55 repeats) and premutations may be in excess in samples with special educational needs. We explored the relationship between FMR1 allele length and cognitive ability in 621 low ability and control children assessed at 4 and 7 years, as well as 122 students with high IQ. The low and high ability and control samples showed no between-group differences in incidence of longer alleles. In males there was a significant negative correlation between allele length and non-verbal ability at 4 years (p = 0.048), academic achievement in maths (p = 0.003) and English (p = 0.011) at 7 years, and IQ in the high ability group (p = 0.018). There was a significant negative correlation between allele length and a standardised score for IQ and general cognitive ability at age 7 in the entire male sample (p = 0.002). This suggests that, within the normal spectrum of allele length, increased repeat numbers may have a limiting influence on cognitive performance.

  5. Substitution effects in a generalized token economy with pigeons.

    PubMed

    Andrade, Leonardo F; Hackenberg, Timothy D

    2017-01-01

    Pigeons made repeated choices between earning and exchanging reinforcer-specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer-general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed-ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token-production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token-economic methods for assessing demand for and substitution among multiple commodities in a laboratory context.

  6. Protective effect of CCR5 Delta-32 allele against HIV-1 in Mexican women.

    PubMed

    Estrada-Aguirre, Jesús A; Cázarez-Salazar, Silvestre G; Ochoa-Ramírez, Luis A; Acosta-Cota, Selene de J; Zamora-Gómez, Román; Najar-Reyes, Guilermi M; Villarreal-Escamilla, Perla; Osuna-Ramírez, Ignacio; Díaz-Camacho, Sylvia P; Sánchez-Zazueta, Jorge G; Ríos-Tostado, Juan J; Velarde-Félix, Jesús S

    2013-09-01

    C-C chemokine receptor type 5 (CCR5) is known for its role as a co-receptor for HIV-1 infection. Some individuals possess a 32 bp deletion, known as Delta-32 allele which has been reported to confer resistance to HIV-1 infection. In order to estimate the distribution of Delta-32 allele of CCR5 gene, 1034 mestizo individuals from the Northwest of Mexico, including 385 HIV-1-infected individuals, 472 healthy controls and 177 uninfected female sex workers; were examined by allele-specific PCR. There was no statistically significant difference in the frequency of Delta-32 allele between HIV-1 positive and healthy individuals (OR= 1.1, p= 0.6). However, we found a significantly reduced prevalence of CCR5 Delta-32 heterozygous genotype in female patients (OR= 0.084, 95% CI= 0.011 - 0.630, p= 0.002), as well as in allele frequency, compared to male patients. Furthermore, we observed an inverse relationship between allele frequency and the risk of HIV-1 transmission and AIDS progression among female healthy controls, sex workers and HIV-1 infected groups. Our findings support previous data showing Delta-32 as a genetic protective factor against HIV-1 infection in Mexican women, as well as in women from other populations.

  7. Allelic Variation in Developmental Genes and Effects on Winter Wheat Heading Date in the U.S. Great Plains.

    PubMed

    Grogan, Sarah M; Brown-Guedira, Gina; Haley, Scott D; McMaster, Gregory S; Reid, Scott D; Smith, Jared; Byrne, Patrick F

    2016-01-01

    Heading date in wheat (Triticum aestivum L.) and other small grain cereals is affected by the vernalization and photoperiod pathways. The reduced-height loci also have an effect on growth and development. Heading date, which occurs just prior to anthesis, was evaluated in a population of 299 hard winter wheat entries representative of the U.S. Great Plains region, grown in nine environments during 2011-2012 and 2012-2013. The germplasm was evaluated for candidate genes at vernalization (Vrn-A1, Vrn-B1, and Vrn-D1), photoperiod (Ppd-A1, Ppd-B1 and Ppd-D1), and reduced-height (Rht-B1 and Rht-D1) loci using polymerase chain reaction (PCR) and Kompetitive Allele Specific PCR (KASP) assays. Our objectives were to determine allelic variants known to affect flowering time, assess the effect of allelic variants on heading date, and investigate changes in the geographic and temporal distribution of alleles and haplotypes. Our analyses enhanced understanding of the roles developmental genes have on the timing of heading date in wheat under varying environmental conditions, which could be used by breeding programs to improve breeding strategies under current and future climate scenarios. The significant main effects and two-way interactions between the candidate genes explained an average of 44% of variability in heading date at each environment. Among the loci we evaluated, most of the variation in heading date was explained by Ppd-D1, Ppd-B1, and their interaction. The prevalence of the photoperiod sensitive alleles Ppd-A1b, Ppd-B1b, and Ppd-D1b has gradually decreased in U.S. Great Plains germplasm over the past century. There is also geographic variation for photoperiod sensitive and reduced-height alleles, with germplasm from breeding programs in the northern Great Plains having greater incidences of the photoperiod sensitive alleles and lower incidence of the semi-dwarf alleles than germplasm from breeding programs in the central or southern plains.

  8. Allelic Variation in Developmental Genes and Effects on Winter Wheat Heading Date in the U.S. Great Plains

    PubMed Central

    Brown-Guedira, Gina; Haley, Scott D.; McMaster, Gregory S.; Reid, Scott D.; Smith, Jared; Byrne, Patrick F.

    2016-01-01

    Heading date in wheat (Triticum aestivum L.) and other small grain cereals is affected by the vernalization and photoperiod pathways. The reduced-height loci also have an effect on growth and development. Heading date, which occurs just prior to anthesis, was evaluated in a population of 299 hard winter wheat entries representative of the U.S. Great Plains region, grown in nine environments during 2011–2012 and 2012–2013. The germplasm was evaluated for candidate genes at vernalization (Vrn-A1, Vrn-B1, and Vrn-D1), photoperiod (Ppd-A1, Ppd-B1 and Ppd-D1), and reduced-height (Rht-B1 and Rht-D1) loci using polymerase chain reaction (PCR) and Kompetitive Allele Specific PCR (KASP) assays. Our objectives were to determine allelic variants known to affect flowering time, assess the effect of allelic variants on heading date, and investigate changes in the geographic and temporal distribution of alleles and haplotypes. Our analyses enhanced understanding of the roles developmental genes have on the timing of heading date in wheat under varying environmental conditions, which could be used by breeding programs to improve breeding strategies under current and future climate scenarios. The significant main effects and two-way interactions between the candidate genes explained an average of 44% of variability in heading date at each environment. Among the loci we evaluated, most of the variation in heading date was explained by Ppd-D1, Ppd-B1, and their interaction. The prevalence of the photoperiod sensitive alleles Ppd-A1b, Ppd-B1b, and Ppd-D1b has gradually decreased in U.S. Great Plains germplasm over the past century. There is also geographic variation for photoperiod sensitive and reduced-height alleles, with germplasm from breeding programs in the northern Great Plains having greater incidences of the photoperiod sensitive alleles and lower incidence of the semi-dwarf alleles than germplasm from breeding programs in the central or southern plains. PMID:27058239

  9. Effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion

    PubMed Central

    2011-01-01

    In sheep polymorphisms of the prion gene (PRNP) at the codons 136, 154 and 171 strongly influence the susceptibility to scrapie and bovine spongiform encephalopathy (BSE) infections. In goats a number of other gene polymorphisms were found which are suspected to trigger similar effects. However, no strong correlation between polymorphisms and TSE susceptibility in goats has yet been obtained from epidemiological studies and only a low number of experimental challenge data are available at present. We have therefore studied the potential impact of these polymorphisms in vitro by cell-free conversion assays using mouse scrapie strain Me7. Mouse scrapie brain derived PrPSc served as seeds and eleven recombinant single mutation variants of sheep and goat PrPC as conversion targets. With this approach it was possible to assign reduced conversion efficiencies to specific polymorphisms, which are associated to low frequency in scrapie-affected goats or found only in healthy animals. Moreover, we could demonstrate a dominant-negative inhibition of prion polymorphisms associated with high susceptibility by alleles linked to low susceptibility in vitro. PMID:21324112

  10. Dominance and parent-of-origin effects of coding and non-coding alleles at the acylCoA-diacylglycerol-acyltransferase (DGAT1) gene on milk production traits in German Holstein cows

    PubMed Central

    Kuehn, Christa; Edel, Christian; Weikard, Rosemarie; Thaller, Georg

    2007-01-01

    Background Substantial gene substitution effects on milk production traits have formerly been reported for alleles at the K232A and the promoter VNTR loci in the bovine acylCoA-diacylglycerol-acyltransferase 1 (DGAT1) gene by using data sets including sires with accumulated phenotypic observations of daughters (breeding values, daughter yield deviations). However, these data sets prevented analyses with respect to dominance or parent-of-origin effects, although an increasing number of reports in the literature outlined the relevance of non-additive gene effects on quantitative traits. Results Based on a data set comprising German Holstein cows with direct trait measurements, we first confirmed the previously reported association of DGAT1 promoter VNTR alleles with milk production traits. We detected a dominant mode of effects for the DGAT1 K232A and promoter VNTR alleles. Namely, the contrasts between the effects of heterozygous individuals at the DGAT1 loci differed significantly from the midpoint between the effects for the two homozygous genotypes for several milk production traits, thus indicating the presence of dominance. Furthermore, we identified differences in the magnitude of effects between paternally and maternally inherited DGAT1 promoter VNTR – K232A haplotypes indicating parent-of-origin effects on milk production traits. Conclusion Non-additive effects like those identified at the bovine DGAT1 locus have to be accounted for in more specific QTL detection models as well as in marker assisted selection schemes. The DGAT1 alleles in cattle will be a useful model for further investigations on the biological background of non-additive effects in mammals due to the magnitude and consistency of their effects on milk production traits. PMID:17892573

  11. Effect Of Neodymium Substitution In Structural Characteristics Of Magnesium Ferrite

    SciTech Connect

    Thankachan, Smitha; Binu, P. J.; Xavier, Sheena; Mohammed, E. M.

    2011-10-20

    The effect of Nd{sup 3+} substitution on the structural properties of Magnesium ferrite was studied in the series MgNd{sub x}Fe{sub 2-x}O{sub 4}, where x = 0 to 0.3 in steps of 0.05. The series was prepared by sol-gel technique which is one of the novel technique to prepare nanosized samples. Structural characterization was done using X-ray diffractometer and Fourier Transform Infrared Spectrometer. XRD analysis reveals the prepared samples are single phasic till x = 0.2. From x0 = .25, a secondary phase of iron neodymium oxide appears along with the spinel phase. Particle size calculation shows the prepared samples are in the 9nm to 11 nm regime. Lattice parameter was found to increase with concentration of Nd. XRD and FTIR analysis confirmed spinel structure of the prepared samples. XRF result shows the expected composition of prepared samples. The frequency dependence of the dielectric constant in the range 100 Hz--120MHz was also studied

  12. Theoretical analysis of kinetic isotope effects on proton transfer reactions between substituted alpha-methoxystyrenes and substituted acetic acids.

    PubMed

    Wong, Kin-Yiu; Richard, John P; Gao, Jiali

    2009-10-07

    Primary kinetic isotope effects (KIEs) on a series of carboxylic acid-catalyzed protonation reactions of aryl-substituted alpha-methoxystyrenes (X-1) to form oxocarbenium ions have been computed using the second-order Kleinert variational perturbation theory (KP2) in the framework of Feynman path integrals (PI) along with the potential energy surface obtained at the B3LYP/6-31+G(d,p) level. Good agreement with the experimental data was obtained, demonstrating that this novel computational approach for computing KIEs of organic reactions is a viable alternative to the traditional method employing Bigeleisen equation and harmonic vibrational frequencies. Although tunneling makes relatively small contributions to the lowering of the free energy barriers for the carboxylic acid catalyzed protonation reaction, it is necessary to include tunneling contributions to obtain quantitative estimates of the KIEs. Consideration of anharmonicity can further improve the calculated KIEs for the protonation of substituted alpha-methoxystyrenes by chloroacetic acid, but for the reactions of the parent and 4-NO(2) substituted alpha-methoxystyrene with substituted carboxylic acids, the correction of anharmonicity overestimates the computed KIEs for strong acid catalysts. In agreement with experimental findings, the largest KIEs are found in nearly ergoneutral reactions, DeltaG(o) approximately 0, where the transition structures are nearly symmetric and the reaction barriers are relatively low. Furthermore, the optimized transition structures are strongly dependent on the free energy for the formation of the carbocation intermediate, that is, the driving force DeltaG(o), along with a good correlation of Hammond shift in the transition state structure.

  13. Theoretical Analysis of Kinetic Isotope Effects on Proton Transfer Reactions between Substituted α-Methoxystyrenes and Substituted Acetic Acids

    PubMed Central

    Wong, Kin Yiu; Richard, John P.; Gao, Jiali

    2009-01-01

    Primary kinetic isotope effects (KIEs) on a series of carboxylic acid-catalyzed protonation reactions of aryl-substituted α-methoxystyrenes (X-1) to form oxocarbenium ions have been computed using the Kleinert variational second-order perturbation theory (KP2) in the framework of Feynman path integrals (PI) along with the potential energy surface obtained at the B3LYP/6-31+G(d,p) level. Good agreement with the experimental data was obtained, demonstrating that this novel computational approach for computing KIEs of organic reactions is a viable alternative to the traditional method employing Bigeleisen equation and harmonic vibrational frequencies. Although tunneling makes relative small contributions to the lowering of the free energy barriers for the carboxylic acid catalyzed protonation reaction, it is necessary to include tunneling contributions to obtain quantitative estimates of the KIEs. Consideration of anharmonicity can further improve the calculated KIEs for the protonation of substituted α-methoxystyrenes by chloroacetic acid, but for the reactions of the parent and 4-NO2 substituted α-methoxystyrene with substituted carboxylic acids, the correction of anharmonicity overestimates the computed KIEs for strong acid catalysts. In agreement with experimental findings, the largest KIEs are found in nearly ergoneutral reactions, ΔGo ≈ 0, where the transition structures are nearly symmetric and the reaction barriers are relatively low. Furthermore, the optimized transition structures are strongly dependent on the free energy for the formation of the carbocation intermediate, i.e., the driving force ΔGo, along with a good correlation of Hammond shift in the transition state structure. PMID:19754046

  14. Effects of allele frequency estimation on genomic predictions and inbreeding coefficients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic calculations often require estimating allele frequencies, which differ across time due to selection and drift. Data were 50,000 simulated markers and 39,985 actual markers for 2391 genotyped Holstein bulls. Gene content of relatives and gene frequencies in the base (founder) population were ...

  15. The effect of dominant vestigial alleles upon vestigial-mediated wing patterning during development of Drosophila melanogaster.

    PubMed

    Simmonds, A; Hughes, S; Tse, J; Cocquyt, S; Bell, J

    1997-09-01

    The vestigial gene product is required for the completion of wing development in Drosophila melanogaster. In the absence of vestigial gene expression, cells within the larval wing and haltere imaginal discs fail to proliferate normally thus producing adults with severely reduced wings. Of a large number of vestigial mutations that have been characterized, only two are currently known to exist, vestigial(U) and vestigial(W), which manifest a significant dominant phenotype. Both are associated with chromosomal inversions that fuse the majority of the vestigial coding regions to other genes; mastermind in vestigial(U) and invected in vestigial(W) Examination of vestigial expression in the presence of these dominant alleles shows alterations in the disc-specific expression of vestigial during later stages of larval development. These patterning disruptions are specific to cells of the wing imaginal disc, as significant suppression of total levels of vestigial expression within entire larvae could not be detected. This dominant interference of vestigial patterning appears to be mediated in part by the vestigial coding sequences that are within the gene fusions. Further evidence that the dominant phenotype is the result of disrupted vestigial patterning comes from observations that the dominant alleles can be partially suppressed by mutations within the Drosophila-epidermal growth factor receptor gene. Mutagenesis of vestigial(U) and vestigial(W) produced a series of alleles with partially dominant phenotypes that restored various amounts of the adult wing. These phenotypes can be correlated with alterations in specific portions of the vestigial sequences associated with the dominant alleles. In the presence of these partially dominant alleles, wing imaginal discs have significantly more cells which express vestigial compared with the number associated with the original dominant phenotype. Additionally, eliminating some of the dominant effect causes alterations in the

  16. Substitution of cysteine for glycine at residue 415 of one allele of the alpha 1(I) chain of type I procollagen in type III/IV osteogenesis imperfecta.

    PubMed Central

    Nicholls, A C; Oliver, J; Renouf, D V; Keston, M; Pope, F M

    1991-01-01

    We have examined the type I collagen in a patient with type III/IV osteogenesis imperfecta. Two forms of alpha 1(I) chain were produced, one normal and the other containing a cysteine residue within the triple helical domain of the molecule. Cysteine is not normally present in this domain of type I collagen. Peptide mapping experiments localised the mutation to peptide alpha 1(I)CB3 which spans residues 403 to 551 of the triple helix. Subsequent PCR amplification of cDNA covering this region followed by sequencing showed a G to T single base change in the GGC codon for glycine 415 generating TGC, the codon for cysteine. The effect of the mutation on the protein is to delay secretion from the cell, reduce the thermal stability of the molecule by 2 degrees C, and cause excessive post-translational modification of all chains in molecules containing one or more mutant alpha 1(I) chains. The clinical phenotype observed in this patient and the position of the mutation conform to the recent prediction of Starman et al that Gly----Cys mutations in the alpha 1(I) chain have a gradient of severity decreasing from the C-terminus to the N-terminus. Images PMID:1770532

  17. Frequency Specific Effects of ApoE ε4 Allele on Resting-State Networks in Nondemented Elders

    PubMed Central

    Liang, Ying; Li, Zhenzhen; Neuroimaging Initiative, Alzheimer's Disease

    2017-01-01

    We applied resting-state functional magnetic resonance imaging (fMRI) to examine the Apolipoprotein E (ApoE) ε4 allele effects on functional connectivity of the default mode network (DMN) and the salience network (SN). Considering the frequency specific effects of functional connectivity, we decomposed the brain network time courses into two bands: 0.01–0.027 Hz and 0.027–0.08 Hz. All scans were acquired by the Alzheimer's Disease Neuroscience Initiative (ADNI). Thirty-two nondemented subjects were divided into two groups based on the presence (n = 16) or absence (n = 16) of the ApoE ε4 allele. We explored the frequency specific effects of ApoE ε4 allele on the default mode network (DMN) and the salience network (SN) functional connectivity. Compared to ε4 noncarriers, the DMN functional connectivity of ε4 carriers was significantly decreased while the SN functional connectivity of ε4 carriers was significantly increased. Many functional connectivities showed significant differences at the lower frequency band of 0.01–0.027 Hz or the higher frequency band of 0.027–0.08 Hz instead of the typical range of 0.01–0.08 Hz. The results indicated a frequency dependent effect of resting-state signals when investigating RSNs functional connectivity.

  18. Inheritance of low pasting temperature in sweetpotato starch and the dosage effect of wild-type alleles

    PubMed Central

    Katayama, Kenji; Tamiya, Seiji; Sakai, Tetsufumi; Kai, Yumi; Ohara-Takada, Akiko; Kuranouchi, Toshikazu; Yoshinaga, Masaru

    2015-01-01

    Sweetpotato (Ipomoea batatas (L.) Lam.), which is an outcrossing hexaploid, is one of the most important starch-producing crops in the world. During the last decade, new sweetpotato cultivars, e.g. ‘Quick Sweet’, which have approximately 20°C lower pasting temperature, slower retrogradation and higher digestibility of raw starch than ordinary cultivars, have been developed in Japan. Genetic analysis of these variants with low pasting temperature starch was conducted in this study. Using 8 variants and 15 normal clones, 26 families were generated. The results from analyzing these progenies suggested that this trait is a qualitative character controlled by one recessive allele (designated spt), which is inherited in a hexasomic manner. A dosage effect of the wild-type Spt allele was found for starch pasting temperature, although the effect was not linear. These results will aid breeders to develop sweetpotato cultivars with a range of starch pasting temperatures. PMID:26366119

  19. Triazolium based ionic liquid crystals: Effect of asymmetric substitution

    SciTech Connect

    Stappert, K.; Mudring, A. -V.

    2015-01-27

    A new series of ten different asymmetrical 1-dodecyl-3-alkyl-triazolium bromides, [C12CnTr][Br], has been synthesized and their mesomorphic behavior studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). The influence of the chain length of the triazolium salts is investigated to explore the effect of asymmetric substitution on the phase behaviour of these compounds. For that reason, the length of one alkyl chain was varied from 14 to 1 carbon atoms (n = 14, 12, 10, 8–4, 2, 1) while the other alkyl chain was kept at 12 carbon. Single crystal X-ray structure analysis of compounds [C12C12Tr][Br] and [C12C5Tr][Br] reveal that the cations adopt a U-shaped conformation with head-to-head arranged triazolium cores. In contrast, for [C12C1Tr][Br], a rod like shape of the cation with interdigitated alkyl chains is found. All investigated compounds are thermotropic liquid crystals. Higher ordered smectic phases, smectic C as well as smectic A phases were found depending on the chain length of the cation. Moreover, the clearing point temperature decreases with decreasing chain length with exception for the n-dodecyl-3-alkyltrizoliumbromides with the two shortest alkyl chains, [C12C2Tr][Br] and [C12C1Tr][Br], which present higher clearing temperatures (86 and 156 °C) and are structurally distinctly different.

  20. Triazolium based ionic liquid crystals: Effect of asymmetric substitution

    DOE PAGES

    Stappert, K.; Mudring, A. -V.

    2015-01-27

    A new series of ten different asymmetrical 1-dodecyl-3-alkyl-triazolium bromides, [C12CnTr][Br], has been synthesized and their mesomorphic behavior studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). The influence of the chain length of the triazolium salts is investigated to explore the effect of asymmetric substitution on the phase behaviour of these compounds. For that reason, the length of one alkyl chain was varied from 14 to 1 carbon atoms (n = 14, 12, 10, 8–4, 2, 1) while the other alkyl chain was kept at 12 carbon. Single crystal X-ray structure analysis ofmore » compounds [C12C12Tr][Br] and [C12C5Tr][Br] reveal that the cations adopt a U-shaped conformation with head-to-head arranged triazolium cores. In contrast, for [C12C1Tr][Br], a rod like shape of the cation with interdigitated alkyl chains is found. All investigated compounds are thermotropic liquid crystals. Higher ordered smectic phases, smectic C as well as smectic A phases were found depending on the chain length of the cation. Moreover, the clearing point temperature decreases with decreasing chain length with exception for the n-dodecyl-3-alkyltrizoliumbromides with the two shortest alkyl chains, [C12C2Tr][Br] and [C12C1Tr][Br], which present higher clearing temperatures (86 and 156 °C) and are structurally distinctly different.« less

  1. Effects of KCl substitution on textural properties of Queso Fresco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Partial substitution of KCl for NaCl has been attempted in some common cheese varieties because of restrictions on sodium in the diets of some consumers. The changes in texture of Queso Fresco, a popular Hispanic cheese, were monitored during refrigerated storage after replacing some of the NaCl wi...

  2. Protective Effect of HLA-DQB1 Alleles Against Alloimmunization in Patients with Sickle Cell Disease

    PubMed Central

    Tatari-Calderone, Zohreh; Gordish-Dressman, Heather; Fasano, Ross; Riggs, Michael; Fortier, Catherine; Andrew; Campbell, D.; Charron, Dominique; Gordeuk, Victor R.; Luban, Naomi L.C.; Vukmanovic, Stanislav; Tamouza, Ryad

    2015-01-01

    Background Alloimmunization or the development of alloantibodies to Red Blood Cell (RBC) antigens is considered one of the major complications after RBC transfusions in patients with sickle cell disease (SCD) and can lead to both acute and delayed hemolytic reactions. It has been suggested that polymorphisms in HLA genes, may play a role in alloimmunization. We conducted a retrospective study analyzing the influence of HLA-DRB1 and DQB1 genetic diversity on RBC-alloimmunization. Study design Two-hundred four multi-transfused SCD patients with and without RBC-alloimmunization were typed at low/medium resolution by PCR-SSO, using IMGT-HLA Database. HLA-DRB1 and DQB1 allele frequencies were analyzed using logistic regression models, and global p-value was calculated using multiple logistic regression. Results While only trends towards associations between HLA-DR diversity and alloimmunization were observed, analysis of HLA-DQ showed that HLA-DQ2 (p=0.02), -DQ3 (p=0.02) and -DQ5 (p=0.01) alleles were significantly higher in non-alloimmunized patients, likely behaving as protective alleles. In addition, multiple logistic regression analysis showed both HLA-DQ2/6 (p=0.01) and HLA-DQ5/5 (p=0.03) combinations constitute additional predictor of protective status. Conclusion Our data suggest that particular HLA-DQ alleles influence the clinical course of RBC transfusion in patients with SCD, which could pave the way towards predictive strategies. PMID:26476208

  3. Effect of the hope FT-B1 allele on wheat heading time and yield components.

    PubMed

    Nitcher, Rebecca; Pearce, Stephen; Tranquilli, Gabriela; Zhang, Xiaoqin; Dubcovsky, Jorge

    2014-01-01

    Precise regulation of flowering time is critical for plant reproductive success and, in cereals, to maximize grain yields. Seasonal cues including temperature and day length are integrated to regulate the timing of flowering. In temperate cereals, extended periods of cold (vernalization) release the repression of FLOWERING LOCUS T1 (FT1), which is upregulated in the leaves in response to inductive long-day photoperiods. FT1 is a homolog of rice HD3a, which encodes a protein transported from leaves to the shoot apical meristem to induce flowering. A rare FT-B1 allele from the wheat variety "Hope" has been previously shown to be associated with an early flowering phenotype under long-day photoperiods. Here, we demonstrate that the Hope FT-B1 allele accelerates flowering even under short days, and that it is epistatic to the VERNALIZATION 1 (VRN1) gene. On average, the introgression of Hope FT-B1 into 6 genetic backgrounds resulted in 2.6 days acceleration of flowering (P<0.0001) and 4.1% increase in spike weight (P=0.0093), although in one variety, it was associated with a decrease in spike weight. These results suggest that the Hope FT-B1 allele could be useful in wheat breeding programs to subtly accelerate floral development and increase adaptation to changing environments.

  4. Identification of Alleles of Puroindoline Genes and Their Effect on Wheat (Triticum aestivum L.) Grain Texture

    PubMed Central

    Štiasna, Klára; Vyhnánek, Tomáš; Trojan, Václav; Mrkvicová, Eva; Hřivna, Luděk; Havel, Ladislav

    2016-01-01

    Summary Grain hardness is one of the most important quality characteristics of wheat (Triticum aestivum L.). It is a significant property of wheat grains and relates to milling quality and end product quality. Grain hardness is caused by the presence of puroindoline genes (Pina and Pinb). A collection of 25 genotypes of wheat with unusual grain colour (blue aleurone, purple and white pericarp, yellow endosperm) was studied by polymerase chain reaction (PCR) for the diversity within Pina and Pinb (alleles: Pina-D1a, Pina-D1b, Pinb-D1a, Pinb- -D1b, Pinb-D1c and Pinb-D1d). The endosperm structure was determined by a non-destructive method using light transflectance meter and grain hardness by a texture analyser. Genotype Novosibirskaya 67 and isogenic ANK lines revealed hitherto unknown alleles at the locus for the annealing of primers of Pinb-D1. Allele Pinb-D1c was found to be absent from each genotype. The mealy endosperm ranged from 0 to 100% and grain hardness from 15.10 to 26.87 N per sample. PMID:27904399

  5. Seed fates in crop–wild hybrid sunflower: crop allele and maternal effects

    PubMed Central

    Pace, Brian A; Alexander, Helen M; Emry, Jason D; Mercer, Kristin L

    2015-01-01

    Domestication has resulted in selection upon seed traits found in wild populations, yet crop-wild hybrids retain some aspects of both parental phenotypes. Seed fates of germination, dormancy, and mortality can influence the success of crop allele introgression in crop-wild hybrid zones, especially if crop alleles or crop-imparted seed coverings result in out-of-season germination. We performed a seed burial experiment using crop, wild, and diverse hybrid sunflower (Helianthus annuus) cross types to test how a cross type's maternal parent and nuclear genetic composition might affect its fate under field conditions. We observed higher maladaptive fall germination in the crop- and F1- produced seeds than wild-produced seeds and, due to an interaction with percent crop alleles, fall germination was higher for cross types with more crop-like nuclear genetics. By spring, crop-produced cross types had the highest overwintering mortality, primarily due to higher fall germination. Early spring germination was identical across maternal types, but germination continued for F1-produced seeds. In conclusion, the more wild-like the maternal parent or the less proportion of the cross type's genome contributed by the crop, the greater likelihood a seed will remain ungerminated than die. Wild-like dormancy may facilitate introgression through future recruitment from the soil seed bank. PMID:25685189

  6. The effect of particle size on the osteointegration of injectable silicate-substituted calcium phosphate bone substitute materials

    PubMed Central

    Coathup, Melanie J; Cai, Qian; Campion, Charlie; Buckland, Thomas; Blunn, Gordon W

    2013-01-01

    Calcium phosphate (CaP) particles as a carrier in an injectable bone filler allows less invasive treatment of bony defects. The effect of changing granule size within a poloxamer filler on the osteointegration of silicate-substituted calcium phosphate (SiCaP) bone substitute materials was investigated in an ovine critical-sized femoral condyle defect model. Treatment group (TG) 1 consisted of SiCaP granules sized 1000–2000 μm in diameter (100 vol %). TG2 investigated a granule size of 250–500 μm (75 vol %), TG3 a granule size of 90–125 μm (75 vol %) and TG4 a granule size of 90–125 μm (50 vol %). Following a 4 and 8 week in vivo period, bone area, bone-implant contact, and remaining implant area were quantified within each defect. At 4 weeks, significantly increased bone formation was measured in TG2 (13.32% ± 1.38%) when compared with all other groups (p = 0.021 in all cases). Bone in contact with the bone substitute surface was also significantly higher in TG2. At 8 weeks most new bone was associated within defects containing the smallest granule size investigated (at the lower volume) (TG4) (42.78 ± 3.36%) however this group was also associated with higher amounts of fragmented SiCaP. These smaller particles were phagocytosed by macrophages and did not appear to have a negative influence on healing. In conclusion, SiCaP granules of 250–500 μm in size may be a more suitable scaffold when used as an injectable bone filler and may be a convenient method for treating bony defects. © 2013 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 902–910, 2013 PMID:23362131

  7. Effects on murine behavior and lifespan of selectively decreasing expression of mutant huntingtin allele by supt4h knockdown.

    PubMed

    Cheng, Hui-Min; Chern, Yijuang; Chen, I-Hui; Liu, Chia-Rung; Li, Sih-Huei; Chun, Seung J; Rigo, Frank; Bennett, C Frank; Deng, Ning; Feng, Yanan; Lin, Chyuan-Sheng; Yan, Yu-Ting; Cohen, Stanley N; Cheng, Tzu-Hao

    2015-03-01

    Production of protein containing lengthy stretches of polyglutamine encoded by multiple repeats of the trinucleotide CAG is a hallmark of Huntington's disease (HD) and of a variety of other inherited degenerative neurological and neuromuscular disorders. Earlier work has shown that interference with production of the transcription elongation protein SUPT4H results in decreased cellular capacity to transcribe mutant huntingtin gene (Htt) alleles containing long CAG expansions, but has little effect on expression of genes containing short CAG stretches. zQ175 and R6/2 are genetically engineered mouse strains whose genomes contain human HTT alleles that include greatly expanded CAG repeats and which are used as animal models for HD. Here we show that reduction of SUPT4H expression in brains of zQ175 mice by intracerebroventricular bolus injection of antisense 2'-O-methoxyethyl oligonucleotides (ASOs) directed against Supt4h, or in R6/2 mice by deletion of one copy of the Supt4h gene, results in a decrease in mRNA and protein encoded specifically by mutant Htt alleles. We further show that reduction of SUPT4H in mouse brains is associated with decreased HTT protein aggregation, and in R6/2 mice, also with prolonged lifespan and delay of the motor impairment that normally develops in these animals. Our findings support the view that targeting of SUPT4H function may be useful as a therapeutic countermeasure against HD.

  8. Identification of a novel HLA-A allele, A*3120.

    PubMed

    Chang, Y; Pascual, C J; Alonzo, P; Chamizo, A

    2009-03-01

    A novel human leukocyte antigen (HLA)-A allele, HLA-A*3120, was first identified in a National Marrow Donor Program (NMDP) donor. The A*3120 allele resulted from a single nucleotide substitution (T to G) at codon 92 of exon 3 of A*310102. The substitution caused an amino acid change (serine to alanine). This novel allele was also seen in two other unrelated NMDP donors.

  9. Ligand substitution effect on optical properties in conducting tetraazaporphyrines

    SciTech Connect

    Guo, L.; Ellis, D.E.; Gubanova, O.V.; Hoffman, B.M.

    1995-12-31

    Self-consistent Density Functional calculations have been performed on a variety of planar conjugated Ni-centered macrocycles with a basic tetraazaporphyrinic core and dithiolene groups (PZ) or fused-benzo groups (PC). Theoretical energy diagrams, charge and spin distributions and densities of states have been obtained in order to understand the electronic structure modifications due to peripheral ligand substitution. The substituents role in altering electronic properties and charge distribution of the porphyrazine macrocycles has been used to interpret the observed variations in optical absorption profiles. In the Q-band ({approximately} 680 nm) region, a single peak is seen for high symmetry (D{sub 4h}) macrocycles and a double peak for lower symmetry (D{sub 2h} and C{sub 2v}) systems. Calculated intensities and band splittings are compared in detail with qualitative molecular orbital models and experiment in the visible and UV regions. Predictions are made for the infrared absorption and semiconducting band gap.

  10. Novel microsatellite markers for the oriental fruit moth Grapholita molesta (Lepidoptera: Tortricidae) and effects of null alleles on population genetics analyses.

    PubMed

    Song, W; Cao, L-J; Wang, Y-Z; Li, B-Y; Wei, S-J

    2016-11-07

    The oriental fruit moth (OFM) Grapholita molesta (Lepidoptera: Tortricidae) is an important economic pest of stone and pome fruits worldwide. We sequenced the OFM genome using next-generation sequencing and characterized the microsatellite distribution. In total, 56,674 microsatellites were identified, with 11,584 loci suitable for primer design. Twenty-seven polymorphic microsatellites, including 24 loci with trinucleotide repeat and three with pentanucleotide repeat, were validated in 95 individuals from four natural populations. The allele numbers ranged from 4 to 40, with an average value of 13.7 per locus. A high frequency of null alleles was observed in most loci developed for the OFM. Three marker panels, all of the loci, nine loci with the lowest null allele frequencies, and nine loci with the highest null allele frequencies, were established for population genetics analyses. The null allele influenced estimations of genetic diversity parameters but not the OFM's genetic structure. Both a STRUCTURE analysis and a discriminant analysis of principal components, using the three marker panels, divided the four natural populations into three groups. However, more individuals were incorrectly assigned by the STRUCTURE analysis when the marker panel with the highest null allele frequency was used compared with the other two panels. Our study provides empirical research on the effects of null alleles on population genetics analyses. The microsatellites developed will be valuable markers for genetic studies of the OFM.

  11. Unequal allelic frequencies at the self-incompatibility locus within local populations of Prunus avium L.: an effect of population structure?

    PubMed

    Stoeckel, S; Castric, V; Mariette, S; Vekemans, X

    2008-05-01

    In this paper, we investigated the genetic structure and distribution of allelic frequencies at the gametophytic self-incompatibility locus in three populations of Prunus avium L. In line with theoretical predictions under balancing selection, genetic structure at the self-incompatibility locus was almost three times lower than at seven unlinked microsatellites. Furthermore, we found that S-allele frequencies in wild cherry populations departed significantly from the expected isoplethic distribution towards which balancing selection is expected to drive allelic frequencies (i.e. identical frequency equal to the inverse of the number of alleles in the population). To assess whether this departure could be caused either by drift alone or by population structure, we used numerical simulations to compare our observations with allelic frequency distributions expected : (1) within a single deme from a subdivided population with various levels of differentiation; and (2) within a finite panmictic population with identical allelic diversity. We also investigated the effects of sample size and degree of population structure on tests of departure from isoplethic equilibrium. Overall, our results showed that the observed allele frequency distributions were consistent with a model of subdivided population with demes linked by moderate migration rate.

  12. Effect of the myotonic dystrophy expanded (CTG){sub n} repeat on the transcripts of DMPK alleles

    SciTech Connect

    Krahe, R.; Narayana, L.; Sciliano, M.J.

    1994-09-01

    Myotonic dystrophy (DM) is a pleiotropic, autosomal dominantly inherited neuromuscular disease. The clinical phenotype is associated with an unstable (CTG){sub n} repeat in the 3{prime} untranslated region of the candidate gene, DM protein kinase (DMPK). The size of the unstable repeat generally increases through successive generations and correlates to a reasonable degree with the phenotype in a given family. In various studies both decreased and increased levels of mutant steady-state DMPK mRNA and protein levels have been observed and related to (CTG){sub n} repeat expansion. This has led to different proposals to explain the molecular disease mechanism (gene-dosage vs. gain-of-function effect). Using allele-specific transcript amplification, comparative and quantitative MIMIC RT-PCR, and mRNA stability assays for the exon 9-10 region of the DMPK gene, we report co-equal expression of mutant and normal alleles at both hnRNA and mRNA levels. Identical levels of overall mRNA and no allele-specific differences in mRNA stability were seen in adult-onset and congenital DM patients compared to normal controls. The expanded repeat did not appear to interfere with transcriptional initiation or increase or decrease the stability of either primary or mature transcript of the mutant and normal DMPK allele. Similar results were obtained for two homozygous DM sisters. Pairs of somatic cell hybrids - one of the pair containing the chromosome with the expanded (CTG){sub n} repeat, the other with the normal repeat - were generated. We observed equal hnRNA, but significantly reduced mRNA levels for DMPK from exon 8 to 15 for the hybrid containing the expanded repeat, suggesting aberrant processing of mutant hnRNA to mRNA. Therefore, the results of current studies on the effect of the expanded (CTG){sub n} repeat on post-transcriptional events such as splicing downstream of the exon 10 will be reported.

  13. Ten Novel HLA-DRB1 Alleles and One Novel DRB3 Allele

    DTIC Science & Technology

    2006-05-31

    BRIEF COMMUNICATION Ten novel HLA-DRB1 alleles and one novel DRB3 allele A. M. Lazaro1, N. K. Steiner1, M. E. Moraes2, J. R. Moraes2, J. Ng1, R. J...accepted for publication 31 May 2005 doi: 10.1111/j.1399-0039.2005.00459.x Abstract Ten novel HLA-DRB1 and one DRB3 alleles are described. Eight of the...substitutions (DRB1*040504, *130103, *160502 and DRB3 *020204). Two alleles differ by two nucleotide changes altering one (DRB1*1447 and *1361) amino acid and

  14. Distribution of photoperiod-insensitive allele Ppd-A1a and its effect on heading time in Japanese wheat cultivars.

    PubMed

    Seki, Masako; Chono, Makiko; Nishimura, Tsutomu; Sato, Mikako; Yoshimura, Yasuhiro; Matsunaka, Hitoshi; Fujita, Masaya; Oda, Shunsuke; Kubo, Katashi; Kiribuchi-Otobe, Chikako; Kojima, Hisayo; Nishida, Hidetaka; Kato, Kenji

    2013-09-01

    The Ppd-A1 genotype of 240 Japanese wheat cultivars and 40 foreign cultivars was determined using a PCR-based method. Among Japanese cultivars, only 12 cultivars, all of which were Hokkaido winter wheat, carried the Ppd-A1a allele, while this allele was not found in Hokkaido spring wheat cultivars or Tohoku-Kyushu cultivars. Cultivars with a photoperiod-insensitive allele headed 6.9-9.8 days earlier in Kanto and 2.5 days earlier in Hokkaido than photoperiod-sensitive cultivars. The lower effect of photoperiod-insensitive alleles observed in Hokkaido could be due to the longer day-length at the spike formation stage compared with that in Kanto. Pedigree analysis showed that 'Purple Straw' and 'Tohoku 118' were donors of Ppd-A1a and Ppd-D1a in Hokkaido wheat cultivars, respectively. Wheat cultivars recently developed in Hokkaido carry photoperiod-insensitive alleles at a high frequency. For efficient utilization of Ppd-1 alleles in the Hokkaido wheat-breeding program, the effect of Ppd-1 on growth pattern and grain yield should be investigated. Ppd-A1a may be useful as a unique gene source for fine tuning the heading time in the Tohoku-Kyushu region since the effect of Ppd-A1a on photoperiod insensitivity appears to differ from the effect of Ppd-B1a and Ppd-D1a.

  15. Quantification of hematite from the visible diffuse reflectance spectrum: effects of aluminum substitution and grain morphology

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Torrent, J.; Barrón, V.; Duan, Z.; Bloemendal, J.

    2010-12-01

    Hematite exists ubiquitously in soils and sediments, and often is aluminum (Al)-substituted. This study systematically investigated the effects of Al substitution on the visible diffuse reflectance spectrum (DRS) of hematite by using several sets of synthetic samples. We found that the position and amplitude of the characteristic absorption band of hematite (estimated from the first and second order derivative curves of Kubelka-Munk remission function spectrum derived from the DRS) was significantly affected by the degree of Al substitution as well as by sample grain morphology. Therefore, there exist ambiguities in quantifying the degree of Al substitution and the mass concentration of hematite using DRS. Nevertheless, if hematite forms under similar environmental conditions, it is possible to establish a transfer function between the DRS parameters and hematite concentration, as discussed here for a Chinese loess-paleosol sequence.

  16. Antioxidant effectiveness generated by one or two phenolic hydroxyl groups in coumarin-substituted dihydropyrazoles.

    PubMed

    Xi, Gao-Lei; Liu, Zai-Qun

    2013-10-01

    A cascade operation was designed to synthesize nine coumarin-substituted dihydropyrazoles with only one or two phenolic hydroxyl groups contained. Antioxidant abilities of the obtained compounds were evaluated by inhibiting 2,2'-azobis(2-amidinopropanehydrochloride) (AAPH)-, Cu2+/glutathione (GSH)-, and .OH-induced oxidation of DNA. It was found that less phenolic hydroxyl groups can enhance the abilities of coumarin-substituted dihydropyrazoles to protect DNA against the oxidation. Moreover, these coumarin-substituted dihydropyrazoles were employed to scavenge 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+.), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that double phenolic hydroxyl groups were more beneficial for enhancing the abilities of coumarin-substituted dihydropyrazoles to quench the aforementioned radicals. Therefore, dihydropyrazole linked with coumarin exhibited powerful antioxidant effectiveness even in the case of less phenolic hydroxyl groups involved.

  17. Effect of ionic substitutions on the structure and dielectric properties of hafnia: A first principles study

    NASA Astrophysics Data System (ADS)

    Cockayne, Eric

    2008-04-01

    First principles calculations were used to study the effects of Si, Ti, Zr, and Ta (+N) substitutional impurities on the structure and dielectric properties of crystalline HfO2. The dielectric constant of monoclinic HfO2 can be enhanced by substituting more polarizable ions for Hf, but the band gap is decreased. Enhancing the permittivity without decreasing the band gap requires forming the tetragonal or cubic phase of HfO2. Among the ions studied, Si alone is found to stabilize a nonmonoclinic phase of HfO2 relative to the monoclinic phase, but only at an atomic concentration above about 20%. Various experiments have reported the formation of nonmonoclinic phases of HfO2 with increased permittivity when other ions are substituted for Hf. It is concluded that these structures are, in general, either metastable or are stabilized by extrinsic factors or by a layered arrangement of the substitutional cations.

  18. Protective effects of the alcohol dehydrogenase-ADH1B*3 allele on attention and behavior problems in adolescents exposed to alcohol during pregnancy.

    PubMed

    Dodge, Neil C; Jacobson, Joseph L; Jacobson, Sandra W

    2014-01-01

    Alcohol dehydrogenase is a critical enzyme in the metabolism of alcohol. Expression of three alleles at the ADH1B locus results in enzymes that differ in turnover rate and affinity for alcohol. The ADH1B*3 allele, which appears to be unique to individuals of African descent, is associated with more rapid alcohol metabolism than the more prevalent ADH1B*1 allele. It has been previously demonstrated that the presence of at least one maternal ADH1B*3 allele confers a protective effect against alcohol teratogenicity in infants and children. This study was conducted to determine whether the presence of the ADH1B*3 allele in the mother or child continues to be protective in alcohol-exposed individuals during adolescence. 186 adolescents and 167 mothers participating in a 14-year follow-up of the Detroit Longitudinal Cohort were genotyped for ADH1B alleles. Behavioral reports were obtained from classroom teachers. Frequencies of the ADH1B*3 allele were 17.6% in the mothers and 21.0% in the adolescents, which are consistent with the 15-20% expected for African Americans. Prenatal alcohol exposure was associated with increased attention problems and externalizing behaviors in adolescents born to mothers with two ADH1B*1 alleles but not in those whose mothers had at least one ADH1B*3 allele. A similar pattern was seen in relation to the presence or absence of an ADH1B*3 allele in the adolescent, which may have reflected the presence/absence of the maternal variant. This study is the first to demonstrate that the protective effects of the maternal ADH1B*3 allele continue to be evident during adolescence. These persistent individual differences in vulnerability of offspring to the behavioral effects of fetal alcohol exposure are likely attributable to more rapid metabolism of alcohol that the ADH1B*3 variant confers on the mother, leading to a reduction of the peak blood alcohol concentration to which the fetus is exposed during each drinking episode.

  19. Maximum-likelihood and markov chain monte carlo approaches to estimate inbreeding and effective size from allele frequency changes.

    PubMed Central

    Laval, Guillaume; SanCristobal, Magali; Chevalet, Claude

    2003-01-01

    Maximum-likelihood and Bayesian (MCMC algorithm) estimates of the increase of the Wright-Malécot inbreeding coefficient, F(t), between two temporally spaced samples, were developed from the Dirichlet approximation of allelic frequency distribution (model MD) and from the admixture of the Dirichlet approximation and the probabilities of fixation and loss of alleles (model MDL). Their accuracy was tested using computer simulations in which F(t) = 10% or less. The maximum-likelihood method based on the model MDL was found to be the best estimate of F(t) provided that initial frequencies are known exactly. When founder frequencies are estimated from a limited set of founder animals, only the estimates based on the model MD can be used for the moment. In this case no method was found to be the best in all situations investigated. The likelihood and Bayesian approaches give better results than the classical F-statistics when markers exhibiting a low polymorphism (such as the SNP markers) are used. Concerning the estimations of the effective population size all the new estimates presented here were found to be better than the F-statistics classically used. PMID:12871924

  20. Genetic effects of individual chromosomes in cotton cultivars detected by using chromosome substitution lines as genetic probes.

    PubMed

    Wu, Jixiang; Jenkins, Johnie N; McCarty, Jack C; Saha, Sukumar

    2010-12-01

    Determination of chromosomes or chromosome arms with desirable genes in different inbred lines and/or crosses should provide useful genetic information for crop improvement. In this study, we applied a modified additive-dominance model to analyze a data set of 13 cotton chromosome substitution lines and their recurrent parent TM-1, five commercial cultivars, and their 70 F(2) hybrids. The chromosome additive and dominance variance components for eight agronomic and fiber traits were determined. On average, each chromosome or chromosome arm was associated with 6.5 traits in terms of additive and/or dominance effects. The chromosomes or chromosome arms, which contributed significant additive variances for the traits investigated, included 2, 16, 18, 25, 5sh (short arm), 14sh, 15sh, 22sh, and 22Lo (long arm). Chromosome additive effects were also predicted in this study. The results showed that CS-B 25 was favorably associated with several fiber traits, while FM966 was favorably associated with both yield and fiber traits with alleles on multiple chromosomes or chromosome arms. Thus, this study should provide valuable genetic information on pure line development for several improved traits such as yield and fiber quality.

  1. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-01

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  2. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    DOE PAGES

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-21

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here we present a study of the substitution of Ge for Si atomsmore » in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

  3. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    SciTech Connect

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-21

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  4. A risk prediction algorithm for ovarian cancer incorporating BRCA1, BRCA2, common alleles and other familial effects

    PubMed Central

    Jervis, Sarah; Song, Honglin; Lee, Andrew; Dicks, Ed; Harrington, Patricia; Baynes, Caroline; Manchanda, Ranjit; Easton, Douglas F; Jacobs, Ian; Pharoah, Paul P D; Antoniou, Antonis C

    2015-01-01

    Background Although BRCA1 and BRCA2 mutations account for only ∼27% of the familial aggregation of ovarian cancer (OvC), no OvC risk prediction model currently exists that considers the effects of BRCA1, BRCA2 and other familial factors. Therefore, a currently unresolved problem in clinical genetics is how to counsel women with family history of OvC but no identifiable BRCA1/2 mutations. Methods We used data from 1548 patients with OvC and their relatives from a population-based study, with known BRCA1/2 mutation status, to investigate OvC genetic susceptibility models, using segregation analysis methods. Results The most parsimonious model included the effects of BRCA1/2 mutations, and the residual familial aggregation was accounted for by a polygenic component (SD 1.43, 95% CI 1.10 to 1.86), reflecting the multiplicative effects of a large number of genes with small contributions to the familial risk. We estimated that 1 in 630 individuals carries a BRCA1 mutation and 1 in 195 carries a BRCA2 mutation. We extended this model to incorporate the explicit effects of 17 common alleles that are associated with OvC risk. Based on our models, assuming all of the susceptibility genes could be identified we estimate that the half of the female population at highest genetic risk will account for 92% of all OvCs. Conclusions The resulting model can be used to obtain the risk of developing OvC on the basis of BRCA1/2, explicit family history and common alleles. This is the first model that accounts for all OvC familial aggregation and would be useful in the OvC genetic counselling process. PMID:26025000

  5. Effect of corn bran particle size and substitution on pasting characteristics of wheat flour

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary fiber in corn bran is known for its beneficial effects on human health and nutrition. Purified ultrafine food-grade corn bran (free of germ and endosperm), a byproduct from the grain milling industry is a good source of dietary fiber. Corn bran substitution effects batter viscosity, cake v...

  6. Effects of sample size, number of markers, and allelic richness on the detection of spatial genetic pattern

    USGS Publications Warehouse

    Landguth, Erin L.; Gedy, Bradley C.; Oyler-McCance, Sara J.; Garey, Andrew L.; Emel, Sarah L.; Mumma, Matthew; Wagner, Helene H.; Fortin, Marie-Josée; Cushman, Samuel A.

    2012-01-01

    The influence of study design on the ability to detect the effects of landscape pattern on gene flow is one of the most pressing methodological gaps in landscape genetic research. To investigate the effect of study design on landscape genetics inference, we used a spatially-explicit, individual-based program to simulate gene flow in a spatially continuous population inhabiting a landscape with gradual spatial changes in resistance to movement. We simulated a wide range of combinations of number of loci, number of alleles per locus and number of individuals sampled from the population. We assessed how these three aspects of study design influenced the statistical power to successfully identify the generating process among competing hypotheses of isolation-by-distance, isolation-by-barrier, and isolation-by-landscape resistance using a causal modelling approach with partial Mantel tests. We modelled the statistical power to identify the generating process as a response surface for equilibrium and non-equilibrium conditions after introduction of isolation-by-landscape resistance. All three variables (loci, alleles and sampled individuals) affect the power of causal modelling, but to different degrees. Stronger partial Mantel r correlations between landscape distances and genetic distances were found when more loci were used and when loci were more variable, which makes comparisons of effect size between studies difficult. Number of individuals did not affect the accuracy through mean equilibrium partial Mantel r, but larger samples decreased the uncertainty (increasing the precision) of equilibrium partial Mantel r estimates. We conclude that amplifying more (and more variable) loci is likely to increase the power of landscape genetic inferences more than increasing number of individuals.

  7. Effects of sample size, number of markers, and allelic richness on the detection of spatial genetic pattern

    USGS Publications Warehouse

    Landguth, E.L.; Fedy, B.C.; Oyler-McCance, S.J.; Garey, A.L.; Emel, S.L.; Mumma, M.; Wagner, H.H.; Fortin, M.-J.; Cushman, S.A.

    2012-01-01

    The influence of study design on the ability to detect the effects of landscape pattern on gene flow is one of the most pressing methodological gaps in landscape genetic research. To investigate the effect of study design on landscape genetics inference, we used a spatially-explicit, individual-based program to simulate gene flow in a spatially continuous population inhabiting a landscape with gradual spatial changes in resistance to movement. We simulated a wide range of combinations of number of loci, number of alleles per locus and number of individuals sampled from the population. We assessed how these three aspects of study design influenced the statistical power to successfully identify the generating process among competing hypotheses of isolation-by-distance, isolation-by-barrier, and isolation-by-landscape resistance using a causal modelling approach with partial Mantel tests. We modelled the statistical power to identify the generating process as a response surface for equilibrium and non-equilibrium conditions after introduction of isolation-by-landscape resistance. All three variables (loci, alleles and sampled individuals) affect the power of causal modelling, but to different degrees. Stronger partial Mantel r correlations between landscape distances and genetic distances were found when more loci were used and when loci were more variable, which makes comparisons of effect size between studies difficult. Number of individuals did not affect the accuracy through mean equilibrium partial Mantel r, but larger samples decreased the uncertainty (increasing the precision) of equilibrium partial Mantel r estimates. We conclude that amplifying more (and more variable) loci is likely to increase the power of landscape genetic inferences more than increasing number of individuals. ?? 2011 Blackwell Publishing Ltd.

  8. Effects of Silicon Substitution in the Main Chain Network Segments of Polycyanurates

    DTIC Science & Technology

    2012-03-28

    cure in silicone molds under N2, cure schedule for 1 hr at 150 °C followed by 24 hrs at 210 °C, with ramp rates at 5 °C / min. ESR255 BADCy SiMCy...Briefing Charts 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Effects of Silicon Substitution in the Main...National Meeting, San Diego, CA, 25-29 March 2012. 14. ABSTRACT This presentation summarizes the study of the effects of silicon substitution in both

  9. Effect of diamagnetic substitution on growth-induced anisotropy in (YBi)3Fe5O12

    NASA Technical Reports Server (NTRS)

    Fratello, V. J.; Slusky, S. E. G.; Brandle, C. D.; Norelli, M. P.

    1986-01-01

    Films of (Y/3-x-y/Bi/x/Pb/y/)(Fe/5-z/Ga/z/)O12(Z = 0-1.1) and (Y/3-x-y/Bi/x/PB/y/)(Fe/5-w/In/w/)O12(w = 0-O.6) garnets were prepared by liquid-phase epitaxy. The effects of tetrahedral Ga and octahedral In substitution on the Bi-based growth-induced uniaxial anisotropy in (Ybi)3Fe5O12 films were measured. Both Ga and In resulted in a linear decrease in the anisotropy with increasing substitution. The effect of octahedral In was twice that of tetrahedral Ga.

  10. Mutant alleles of small effect are primarily responsible for the loss of fitness with slow inbreeding in Drosophila melanogaster.

    PubMed

    Latter, B D

    1998-03-01

    Multilocus simulation is used to identify genetic models that can account for the observed rates of inbreeding and fitness decline in laboratory populations of Drosophila melanogaster. The experimental populations were maintained under crowded conditions for approximately 200 generations at a harmonic mean population size of Nh approximately 65-70. With a simulated population size of N = 50, and a mean selective disadvantage of homozygotes at individual loci approximately 1-2% or less, it is demonstrated that the mean effective population size over a 200-generation period may be considerably greater than N, with a ratio matching the experimental estimate of Ne/Nh approximately 1.4. The buildup of associative overdominance at electrophoretic marker loci is largely responsible for the stability of gene frequencies and the observed reduction in the rate of inbreeding, with apparent selection coefficients in favor of the heterozygote at neutral marker loci increasing rapidly over the first N generations of inbreeding to values approximately 5-10%. The observed decline in fitness under competitive conditions in populations of size approximately 50 in D. melanogaster therefore primarily results from mutant alleles with mean effects on fitness as homozygotes of sm < or = 0.02. Models with deleterious recessive mutants at the background loci require that the mean selection coefficient against heterozygotes is at most hsm approximately 0.002, with a minimum mutation rate for a single Drosophila autosome 100 cM in length estimated to be in the range 0.05-0.25, assuming an exponential distribution of s. A typical chromosome would be expected to carry at least 100-200 such mutant alleles contributing to the decline in competitive fitness with slow inbreeding.

  11. Tuna Species Substitution in the Spanish Commercial Chain: A Knock-On Effect

    PubMed Central

    Gordoa, Ana; Carreras, Gustavo; Sanz, Nuria; Viñas, Jordi

    2017-01-01

    Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe’s biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus), 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers. PMID:28125686

  12. Tuna Species Substitution in the Spanish Commercial Chain: A Knock-On Effect.

    PubMed

    Gordoa, Ana; Carreras, Gustavo; Sanz, Nuria; Viñas, Jordi

    2017-01-01

    Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe's biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus), 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers.

  13. Fine Mapping Seronegative and Seropositive Rheumatoid Arthritis to Shared and Distinct HLA Alleles by Adjusting for the Effects of Heterogeneity

    PubMed Central

    Han, Buhm; Diogo, Dorothée; Eyre, Steve; Kallberg, Henrik; Zhernakova, Alexandra; Bowes, John; Padyukov, Leonid; Okada, Yukinori; González-Gay, Miguel A.; Rantapää-Dahlqvist, Solbritt; Martin, Javier; Huizinga, Tom W.J.; Plenge, Robert M.; Worthington, Jane; Gregersen, Peter K.; Klareskog, Lars; de Bakker, Paul I.W.; Raychaudhuri, Soumya

    2014-01-01

    Despite progress in defining human leukocyte antigen (HLA) alleles for anti-citrullinated-protein-autoantibody-positive (ACPA+) rheumatoid arthritis (RA), identifying HLA alleles for ACPA-negative (ACPA−) RA has been challenging because of clinical heterogeneity within clinical cohorts. We imputed 8,961 classical HLA alleles, amino acids, and SNPs from Immunochip data in a discovery set of 2,406 ACPA− RA case and 13,930 control individuals. We developed a statistical approach to identify and adjust for clinical heterogeneity within ACPA− RA and observed independent associations for serine and leucine at position 11 in HLA-DRβ1 (p = 1.4 × 10−13, odds ratio [OR] = 1.30) and for aspartate at position 9 in HLA-B (p = 2.7 × 10−12, OR = 1.39) within the peptide binding grooves. These amino acid positions induced associations at HLA-DRB1∗03 (encoding serine at 11) and HLA-B∗08 (encoding aspartate at 9). We validated these findings in an independent set of 427 ACPA− case subjects, carefully phenotyped with a highly sensitive ACPA assay, and 1,691 control subjects (HLA-DRβ1 Ser11+Leu11: p = 5.8 × 10−4, OR = 1.28; HLA-B Asp9: p = 2.6 × 10−3, OR = 1.34). Although both amino acid sites drove risk of ACPA+ and ACPA− disease, the effects of individual residues at HLA-DRβ1 position 11 were distinct (p < 2.9 × 10−107). We also identified an association with ACPA+ RA at HLA-A position 77 (p = 2.7 × 10−8, OR = 0.85) in 7,279 ACPA+ RA case and 15,870 control subjects. These results contribute to mounting evidence that ACPA+ and ACPA− RA are genetically distinct and potentially have separate autoantigens contributing to pathogenesis. We expect that our approach might have broad applications in analyzing clinical conditions with heterogeneity at both major histocompatibility complex (MHC) and non-MHC regions. PMID:24656864

  14. Effective marker alleles associated with type II resistance of wheat to Fusarium head blight infection in fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular markers associated with known quantitative trait loci (QTLs) for type 2 resistance to Fusarium head blight (FHB) in bi-parental mapping populations usually have more than two alleles in breeding populations. Therefore, understanding the association of each allele with FHB response is parti...

  15. Mass analyzed threshold ionization spectroscopy of p -aminophenol cation and the substitution effect

    NASA Astrophysics Data System (ADS)

    Xie, Yan; Lin, Jung Lee; Tzeng, Wen Bih

    2004-10-01

    The mass analyzed threshold ionization (MATI) spectra of p-aminophenol have been recorded by ionizing via the vibrationless 0 0 and vibrational 6a 1, 12 1, and 1 1 levels in the S 1 state. The adiabatic ionization energy (IE) of this molecule is determined to be 58,822 ± 5 cm -1. The frequencies of ring vibrational modes 6a, 12, 1, and 18b of the cation are measured to be 458, 768, 835, and 1181 cm -1, respectively. Comparing these new data of p-aminophenol with those of several p-substituted anilines and p-substituted phenols leads to a better understanding about the substitution effects on the IE as well as the cation vibration.

  16. Effect of Mg-Zr substitution and microwave processing on magnetic properties of barium hexaferrite

    NASA Astrophysics Data System (ADS)

    Sharma, Manju; Kashyap, Subhash C.; Gupta, H. C.

    2014-09-01

    The effect of substitution of Mg-Zr for Fe in M-type barium hexaferrite (BHF) and of processing technique on the magnetic properties and microstructure has been reported in the present paper. Significant changes in magnetic properties have been observed on substituting Fe ions by Mg and Zr ions in M-type barium hexaferrite, i.e. BaFe12O19 as well as by single mode microwave processing. The single mode microwave processing of the undoped sample reduced the coercivity to nearly 25% of the value for the sintered sample along with the enhancement in magnetization, thereby making it suitable for memory devices. The improvement in magnetic properties is explained on the basis of microstructure. The addition of substituents, though assisted in the formation of single phase, it, however, degraded the magnetization besides decreasing the coercivity, possibly due to substitution at the octahedral sites.

  17. Orienting response reinstatement and dishabituation: effects of substituting, adding, and deleting components of nonsignificant stimuli.

    PubMed

    Ben-Shakhar, G; Gati, I; Ben-Bassat, N; Sniper, G

    2000-01-01

    The prediction that orienting response (OR) reinstatement is negatively related to the measure of common features, shared by the stimulus input and representations of preceding events, and positively related to the measure of their distinctive features, was examined. A nonsignificant test stimulus (TS) was presented after nine repetitions of a standard stimulus (SS), followed by two additional repetitions of SS. TS was created by either substituting 0, 1, or 2 components of SS (Experiment 1), or by either adding or deleting 0, 1, or 2 components of SS (Experiment 2). Skin conductance changes to TS (OR reinstatement) and the subsequent SS (dishabituation) were used as dependent measures. The results of Experiment 1 supported the prediction that substituting components of neutral stimuli affects OR reinstatement, with a larger effect for between-categories than within-categories substitution. Experiment 2 demonstrated that adding and deleting components similarly affects OR reinstatement.

  18. Protective Effect of R Allele of PON1 Gene on the Coronary Artery Disease in the Presence of Specific Genetic Background

    PubMed Central

    Balcerzyk, Anna; Zak, Iwona; Krauze, Jolanta

    2008-01-01

    Background: Genetic susceptibility to CAD may be determined by polymorphic variants of genes encoding isoforms involved in the processes important in the pathogenesis of atherosclerosis, including lipids disorders. Participation of single polymorphic variants is relatively small, however its significance may increase in the presence of specific genetic or environmental background. Aim: The aim of the study was an evaluation a possible association between single polymorphic variants of PON1, APOE, ABCA1 and PPARA genes and CAD and looking for specific multigene genotype patterns which differentiate study groups. Materials and methods: We studied 358 subjects:178 patients with angiographically confirmed CAD and 180 blood donors without history of CAD. Polymorphisms were genotyped using PCR-RFLP method. Results: We observed statistically significant differences in the frequencies of R allele and R allele carriers of PON1 gene between CAD and controls. The distribution of genotypes and alleles of other analyzed genes did not differentiate the study groups, however the presence of specific genotypes (APOE– ɛ3ɛ3, ɛ3ɛ2, ABCA1 – AG, PPARA – GG) increased the protective effect of R allele. Conclusion: The present study revealed an independent protective association between carrier-state of PON1 R allele and CAD. This protective effect was especially strong in the presence of specific genotype arrangements of other analyzed genes. PMID:18219093

  19. Effects of favorable alleles for water-soluble carbohydrates at grain filling on grain weight under drought and heat stresses in wheat.

    PubMed

    Zhang, Bin; Li, Weiyu; Chang, Xiaoping; Li, Runzhi; Jing, Ruilian

    2014-01-01

    Drought, heat and other abiotic stresses during grain filling can result in reductions in grain weight. Conserved water-soluble carbohydrates (WSC) at early grain filling play an important role in partial compensation of reduced carbon supply. A diverse population of 262 historical winter wheat accessions was used in the present study. There were significant correlations between 1000-grain weight (TGW) and four types of WSC, viz. (1) total WSC at the mid-grain filling stage (14 days after flowering) produced by leaves and non-leaf organs; (2) WSC contributed by current leaf assimilation during the mid-grain filling; (3) WSC in non-leaf organs at the mid-grain filling, excluding the current leaf assimilation; and (4) WSC used for respiration and remobilization during the mid-grain filling. Association and favorable allele analyses of 209 genome-wide SSR markers and the four types of WSC were conducted using a mixed linear model. Seven novel favorable WSC alleles exhibited positive individual contributions to TGW, which were verified under 16 environments. Dosage effects of pyramided favorable WSC alleles and significantly linear correlations between the number of favorable WSC alleles and TGW were observed. Our results suggested that pyramiding more favorable WSC alleles was effective for improving both WSC and grain weight in future wheat breeding programs.

  20. [Lipoprotein metabolism in menopause. Effect of hormonal substitution therapy].

    PubMed

    Heckers, H; Platt, D

    1991-06-20

    Oral administration of conjugated estrogens, estradiol valerate and micronized estradiol--but not the percutaneous application--in the postmenopause modifies the plasmic lipoprotein profile by lowering, dose-dependently, LDL and elevating HDL (HDL2). In parallel, the cardiovascular mortality is decreased by 50-66%, with smokers also benefiting to the same extent. On account of the increased risk for endometrial carcinoma associated with postmenopausal estrogen monotherapy, combination with a lowest-dose gestagen is imperative. However, the very numerous synthetic gestagens can antagonize the favorable effects of the estrogen on lipoprotein metabolism. This applies in particular to the gestagens of the 19-nortestosterone type, such as norethisterone acetate and, in particular, levonorgestrel, but less so the 17-hydroxyprogesterone derivatives medroxyprogesterone acetate and medrogestone with their very low androgenic effect.

  1. The genetics of adaptation to discrete heterogeneous environments: frequent mutation or large-effect alleles can allow range expansion.

    PubMed

    Gilbert, K J; Whitlock, M C

    2017-03-01

    Range expansions are complex evolutionary and ecological processes. From an evolutionary standpoint, a populations' adaptive capacity can determine the success or failure of expansion. Using individual-based simulations, we model range expansion over a two-dimensional, approximately continuous landscape. We investigate the ability of populations to adapt across patchy environmental gradients and examine how the effect sizes of mutations influence the ability to adapt to novel environments during range expansion. We find that genetic architecture and landscape patchiness both have the ability to change the outcome of adaptation and expansion over the landscape. Adaptation to new environments succeeds via many mutations of small effect or few of large effect, but not via the intermediate between these cases. Higher genetic variance contributes to increased ability to adapt, but an alternative route of successful adaptation can proceed from low genetic variance scenarios with alleles of sufficiently large effect. Steeper environmental gradients can prevent adaptation and range expansion on both linear and patchy landscapes. When the landscape is partitioned into local patches with sharp changes in phenotypic optimum, the local magnitude of change between subsequent patches in the environment determines the success of adaptation to new patches during expansion.

  2. Structures and spectroscopic properties of nonperipherally and peripherally substituted metal-free phthalocyanines: a substitution effect study based on density functional theory calculations.

    PubMed

    Zhong, Aimin; Zhang, Yuexing; Bian, Yongzhong

    2010-11-01

    The molecular structures, molecular orbitals, atomic charges, electronic absorption spectra, and infrared (IR) and Raman spectra of a series of substituted metal-free phthalocyanine compounds with four (1, 3, 5, 7) or eight (2, 4, 6, 8) methoxyl (1, 2, 5, 6) or methylthio groups (3, 4, 7, 8) on the nonperipheral (1-4) or peripheral positions (5-8) of the phthalocyanine ring are studied by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The calculated structural parameters and simulated electronic absorption and IR spectra are compared with the X-ray crystallography structures and the experimentally observed electronic absorption and IR spectra of the similar molecules, and good agreement between the calculated and experimental results is found. The substitution of the methoxyl or methylthio groups at the nonperipheral positions of the phthalocyanine ring has obvious effects on the molecular structure and spectroscopic properties of the metal-free phthalocyanine. Nonperipheral substitution has a more significant influence than peripheral substitution. The substitution effect increases with an increase in the number of substituents. The methylthio group shows more significant influence than the methoxyl group, despite the stronger electron-donating property of the methoxyl group than the methylthio group. The octa-methylthio-substituted metal-free phthalocyanine compounds have nonplanar structures whose low-lying occupied molecular orbitals and electronic absorption spectra are significantly changed by the substituents. The present systematical study will be helpful for understanding the relationship between structures and properties in phthalocyanine compounds and designing phthalocyanines with typical properties.

  3. MDMA-like behavioral effects of N-substituted piperazines in the mouse

    PubMed Central

    Yarosh, H.L.; Katz, E.B.; Coop, A.; Fantegrossi, W.E.

    2007-01-01

    Few studies have characterized the subjective effects of N-substituted piperazines, but these drugs show potential for abuse in humans, and have often been associated with MDMA (“ecstasy”) in this regard. The aim of the present studies was to test the capacity of N-substituted piperazines to induce a head-twitch response, alter locomotor activity, and induce MDMA-like discriminative stimulus effects in mice. Various doses of l-benzylpiperazine (BZP), 1-(3-trifluoromethylphenyl) piperazine (TFMPP), 1-(3-methoxybenzyl) piperazine (m-MeO-BZP) or meta-chlorophenyl piperazine (m-CPP) were administered to mice to determine effects on these behavioral endpoints. BZP, but not its meta-methoxyl analogue, increased locomotor activity in a dose-dependent manner; the phenylpiperazines and m-MeO-BZP only decreased locomotor activity. TFMPP was the only compound active in the head twitch assay, eliciting a moderate head twitch response which was comparable to that previously observed with the MDMA enantiomers. BZP, TFMPP and m-CPP fully substituted in S(+)-MDMA-trained animals, but did not elicit significant drug lever responding in mice trained to discriminate R(−)-MDMA. m-MeO-BZP partially substituted for both training drugs. The present results suggest that BZP has stimulant-like effects, and that TFMPP has hallucinogen-like effects. Their structural analogues, however, do not share these behavioral profiles. Further studies into the relationships between the N-substituted piperazines and MDMA are warranted. PMID:17651790

  4. Single-gene speciation with pleiotropy: effects of allele dominance, population size, and delayed inheritance.

    PubMed

    Yamamichi, Masato; Sasaki, Akira

    2013-07-01

    Single-gene speciation is considered to be unlikely, but an excellent example is found in land snails, in which a gene for left-right reversal has given rise to new species multiple times. This reversal might be facilitated by their small population sizes and maternal effect (i.e., "delayed inheritance," in which an individual's phenotype is determined by the genotype of its mother). Recent evidence suggests that a pleiotropic effect of the speciation gene on antipredator survival may also promote speciation. Here we theoretically demonstrate that, without a pleiotropic effect, in small populations the fixation probability of a recessive mutant is higher than a dominant mutant, but they are identical for large populations and sufficiently weak selection. With a pleiotropic effect that increases mutant viability, a dominant mutant has a higher fixation probability if the strength of viability selection is sufficiently greater than that of reproductive incompatibility, whereas a recessive mutant has a higher fixation probability otherwise. Delayed inheritance increases the fixation probability of a mutant if viability selection is sufficiently weaker than reproductive incompatibility. Our results clarify the conflicting effects of viability selection and positive frequency-dependent selection due to reproductive incompatibility and provide a new perspective to single-gene speciation theory.

  5. From Hypo- to Hypersuppression: Effect of Amino Acid Substitutions on the RNA-Silencing Suppressor Activity of the Tobacco etch potyvirus HC-Pro

    PubMed Central

    Torres-Barceló, Clara; Martín, Susana; Daròs, José-Antonio; Elena, Santiago F.

    2008-01-01

    RNA silencing participates in several important functions: from the regulation of cell metabolism and organism development to sequence-specific antiviral defense. Most plant viruses have evolved proteins that suppress RNA silencing and that in many cases are multifunctional. Tobacco etch potyvirus (TEV) HC-Pro protein suppresses RNA silencing and participates in aphid-mediated transmission, polyprotein processing, and genome amplification. In this study, we have generated 28 HC-Pro amino acid substitution mutants and quantified their capacity as suppressors of RNA silencing in a transient expression assay. Most mutations either had no quantitative effect or completely abolished silencing suppression (10 in each class), 3 caused a significant decrease in the activity, and 5 significantly increased it, revealing an unexpected high frequency of mutations conferring hypersuppressor activity. A representative set of the mutant alleles, containing both hypo- and hypersuppressors, was further analyzed for their effect on TEV accumulation and the strength of induced symptoms. Whereas TEV variants with hyposuppressor mutants were far less virulent than wild-type TEV, those with hypersuppressor alleles induced symptoms that were not more severe than those characteristic of the wild-type virus, suggesting that there is not a perfect match between suppression and virulence. PMID:18780745

  6. Long-term effects of salt substitution on blood pressure in a rural north Chinese population.

    PubMed

    Zhou, B; Wang, H-L; Wang, W-L; Wu, X-M; Fu, L-Y; Shi, J-P

    2013-07-01

    Dietary sodium and potassium intake can influence blood pressure. The effects of salt substitution on patients with hypertension and normotensive family member controls, however, have not been evaluated in a rural Chinese population. The objective of this study, accordingly, was to assess the long-term effects of salt substitution on blood pressure. We conducted a double-blind, randomized controlled trial among 200 families in rural China to establish the 2-year effects of a reduced-sodium, high-potassium salt substitute (65% sodium chloride, 25% potassium chloride, 10% magnesium sulfate) compared with normal salt (100% sodium chloride) on blood pressure. Of the 462 individuals in the trial, 372 completed the study (81%). For normotensive subjects, the mean overall difference in systolic and diastolic blood pressure between the two groups at the 24-month follow-up was 2 mm Hg (95% confidence interval (CI) 0-4 mm Hg, P<0.05) and 2 mm Hg (95% CI 1-3 mm Hg, P<0.05), respectively. For subjects with hypertension, the mean overall decrease in systolic blood pressure showed a 4-mm Hg (95% CI 2-6 mm Hg, P<0.05) decrease between the two groups. Diastolic blood pressure was not affected by salt use in the hypertensive group. Salt substitution lowers systolic blood pressure in hypertensive patients and lowers both systolic and diastolic blood pressure in normotensive controls. Salt substitution, therefore, may be an effective adjuvant therapy for hypertensive patients and the potential efficacy in preventing hypertension in normotensive individuals.

  7. Effect of high molecular weight glutenin subunit allelic composition on wheat flour tortilla quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat cultivars possessing quality attributes needed to produce optimum quality tortillas have not been identified. This study investigated the effect of variations in high molecular weight glutenin subunits encoded at the Glu-1 loci (Glu-A1, Glu-B1, Glu-D1) on dough properties and tortilla quality....

  8. Substituting activities mediates the effect of cognitive flexibility on physical activity: a daily diary study.

    PubMed

    Kelly, Scout M; Updegraff, John A

    2017-03-02

    Pursuit of physical activity goals often requires modifying plans, but research on these flexible processes is limited. Cognitive flexibility may heighten one's likelihood of using flexible self-regulatory strategies (e.g., substitution), thereby increasing physical activity. This study used daily diary methodology to test the indirect effect of cognitive flexibility on physical activity via activity substitution. A sample of 128 college students (73% female, mean age 19.9) completed baseline measures and cognitive flexibility assessments, then logged physical activity daily for 2 weeks. Activity substitution was defined as adopting an alternate activity on a day another planned activity was unfulfilled. Controlling for baseline activity, intentions, and time, a multilevel mediation model revealed a significant indirect effect of cognitive flexibility on physical activity via activity substitution (b = 81.36, p = .041). Our results indicate that people with greater cognitive flexibility are more likely to use flexible self-regulation, leading to greater physical activity.

  9. Differential fitness of allelic isozymes in the marine gastropods Littorina punctata and Littorina neritoides, exposed to the environmental stress of the combined effects of cadmium and mercury pollution

    NASA Astrophysics Data System (ADS)

    Lavie, Batia; Nevo, Eviatar

    1987-07-01

    The present study tested the separate and the interactive pollution effects of cadmium and mercury on the electrophoretically detected allelic isozyme frequencies of the enzyme phosphoglucose isomerase for two species of littoral marine gastropods — Littorina punctata and L. neritoides — and the enzyme amino peptidase for L. neritoides. Our results indicate differential survivorship of allelic isozyme genotypes specific for each type of pollutant and for their interaction, as well as trends common to all pollutants. Theoretically the results reflect the adaptive nature of at least some allozymic genotypes in these marine gastropods and seem inconsistent with the neutral theory of allozyme polymorphisms. Practically, the results reinforce earlier conclusions that changes in the frequency of allelic isozymes may be used as a genetic monitor of pollution.

  10. Effect of MC1R variant allele status on MSH-ligand induction of dopachrome tautomerase in melanocytes co-cultured with keratinocytes.

    PubMed

    Ainger, Stephen A; Wong, Shu S; Roberts, Donald W; Leonard, J Helen; Sturm, Richard A

    2011-08-01

    A co-culture system of melanocytic cells and keratinocytes was used to examine dendricity and dopachrome tautomerase (DCT) responses in low penetrant 'r' homozygote and 'R/+' heterozygote MC1R variant allele expressing cells compared to that of wild-type (WT) cells. The V60L-/- homozygote r variant cells showed similar responses to ligand as WT MC1R strains, while V92M-/- homozygote r variant cells were generally shown to have greater dendricity and express higher DCT than the WT cells, even at basal levels. The R151C+/- heterozygote cells showed similar responses to WT cells, while the R160W+/- and D294H+/- variant cells were reduced in their responses to NDP-MSH, but still had an active cAMP response with forskolin treatment. These responses are consistent with the dominant negative effect of these alleles on the MC1R WT allele that has previously been demonstrated genetically and biochemically.

  11. Temperature- and sex-related effects of serine protease alleles on larval development in the Glanville fritillary butterfly.

    PubMed

    Ahola, V; Koskinen, P; Wong, S C; Kvist, J; Paulin, L; Auvinen, P; Saastamoinen, M; Frilander, M J; Lehtonen, R; Hanski, I

    2015-12-01

    The body reserves of adult Lepidoptera are accumulated during larval development. In the Glanville fritillary butterfly, larger body size increases female fecundity, but in males fast larval development and early eclosion, rather than large body size, increase mating success and hence fitness. Larval growth rate is highly heritable, but genetic variation associated with larval development is largely unknown. By comparing the Glanville fritillary population living in the Åland Islands in northern Europe with a population in Nantaizi in China, within the source of the post-glacial range expansion, we identified candidate genes with reduced variation in Åland, potentially affected by selection under cooler climatic conditions than in Nantaizi. We conducted an association study of larval growth traits by genotyping the extremes of phenotypic trait distributions for 23 SNPs in 10 genes. Three genes in clip-domain serine protease family were associated with larval growth rate, development time and pupal weight. Additive effects of two SNPs in the prophenoloxidase-activating proteinase-3 (ProPO3) gene, related to melanization, showed elevated growth rate in high temperature but reduced growth rate in moderate temperature. The allelic effects of the vitellin-degrading protease precursor gene on development time were opposite in the two sexes, one genotype being associated with long development time and heavy larvae in females but short development time in males. Sexually antagonistic selection is here evident in spite of sexual size dimorphism.

  12. The advance of an advantageous allele: Nucleation, front propagation, and seasonal effects

    NASA Astrophysics Data System (ADS)

    O'Malley, Lauren

    Both community ecology and conservation biology seek further understanding of factors governing the advance of an invasive species. I model biological invasion as a two-species, individual-based stochastic process on a two-dimensional landscape. The ecologically superior invader and a resident species compete for space preemptively. The invasive species can occur through random, rare mutations of the resident species, or as a repeated introduction into the environment. To understand how individual-level processes may govern population patterns, I invoke the physical theory for nucleation of spatial systems. Nucleation theory discriminates between single-cluster and multi-cluster dynamics. A sufficiently low mutation or introduction rate, or a sufficiently small environment generates single-cluster dynamics, an inherently stochastic process. An increased mutation or introduction rate, or larger system size generates multi-cluster invasion, where spatial averaging produces nearly deterministic global dynamics. For this process, an analytical approximation from nucleation theory, called Avrami's Law, describes the time-dependent behavior for the densities with remarkable accuracy. Once invasive clusters grow large enough, observations of the invasive advance occur only through a small "window" of space, where we can approximate the advance as that of a linear propagating front. One can then employ the concept of a "roughened" front to quantify effects of discreteness and stochasticity on invasion, and thus study roughening of the front using the framework of non-equilibrium interface growth. The analysis, which includes calculating the scaling (roughness and dynamic) exponents, corrections to the asymptotic front velocity, and the probability distribution of both the surface roughness and the front runner's relative position, indicates that initially flat, linear invading fronts exhibit Kardar-Parisi-Zhang (KPZ) roughening in one transverse dimension. I also study the

  13. The Effect of Te Substitution for Sb on Thermoelectric Properties of Tetrahedrite

    NASA Astrophysics Data System (ADS)

    Lu, Xu; Morelli, Donald

    2014-06-01

    We present the study of the effect of Te substitution on the thermoelectric properties for Sb in Cu12Sb4- x Te x S13 tetrahedrite compounds with x ranging from 0.2 to 1.5 in the temperature range of room temperature to 723 K. Powder x-ray diffraction and electron microscopy results indicate a successful homogenous substitution without the alteration of the crystal structure or the introduction of secondary phases. Thermoelectric property measurements show that the excess electrons from Te during the substitution fill the unoccupied levels near the top of the valence bands in pure Cu12Sb4S13 compound, moving the Fermi level closer to the top of the valence bands. This leads to an enhancement in thermopower but also to an increase in electrical resistivity. Overall, the reduction in total thermal conductivity gives rise to improved ZT values in all substituted samples. The highest ZT value obtained in this study is 0.92 at 723 K for x = 1, which is comparable to that of other p-type bulk thermoelectric materials.

  14. Solvent effects on two-photon absorption of dialkylamino substituted distyrylbenzene chromophore

    NASA Astrophysics Data System (ADS)

    Zhao, Ke; Ferrighi, Lara; Frediani, Luca; Wang, Chuan-Kui; Luo, Yi

    2007-05-01

    Solvent effects on the two-photon absorption of a symmetrical diamino substituted distyrylbenzene chromophore have been studied using the density functional response theory in combination with the polarizable continuum model. It is shown that the dielectric medium has a rather small effect both on the bond length alternation and on the one-photon absorption spectrum, but it affects significantly the two-photon absorption cross section. It is found that both one- and two-photon absorptions are extremely sensitive to the planarity of the molecule, and the absorption intensity can be dramatically reduced by the conformation distortion. It has led to the conclusion that the experimentally observed anomalous solvent effect on the two-photon absorption of dialkylamino substituted distyrylbenzene chromophores cannot be attributed to the intrinsic properties of a single molecule and its interaction with solvents.

  15. Allele-specific effects of ecSOD on asbestos-induced fibroproliferative lung disease in mice.

    PubMed

    Jun, Sujung; Fattman, Cheryl L; Kim, Byung-Jin; Jones, Harlan; Dory, Ladislav

    2011-05-15

    resistance to asbestos-induced lung injury reported for the 129/J strain of mice. The data further suggest allele-specific differences in the regulation of ecSOD expression. These congenic mice therefore represent a very useful model to study the role of this enzyme in all inflammatory diseases. Polymorphisms in human ecSOD have also been reported and it appears logical to assume that such variations may have a profound effect on disease susceptibility.

  16. Likelihood-based estimation of the effective population size using temporal changes in allele frequencies: a genealogical approach.

    PubMed Central

    Berthier, Pierre; Beaumont, Mark A; Cornuet, Jean-Marie; Luikart, Gordon

    2002-01-01

    A new genetic estimator of the effective population size (N(e)) is introduced. This likelihood-based (LB) estimator uses two temporally spaced genetic samples of individuals from a population. We compared its performance to that of the classical F-statistic-based N(e) estimator (N(eFk)) by using data from simulated populations with known N(e) and real populations. The new likelihood-based estimator (N(eLB)) showed narrower credible intervals and greater accuracy than (N(eFk)) when genetic drift was strong, but performed only slightly better when genetic drift was relatively weak. When drift was strong (e.g., N(e) = 20 for five generations), as few as approximately 10 loci (heterozygosity of 0.6; samples of 30 individuals) are sufficient to consistently achieve credible intervals with an upper limit <50 using the LB method. In contrast, approximately 20 loci are required for the same precision when using the classical F-statistic approach. The N(eLB) estimator is much improved over the classical method when there are many rare alleles. It will be especially useful in conservation biology because it less often overestimates N(e) than does N(eLB) and thus is less likely to erroneously suggest that a population is large and has a low extinction risk. PMID:11861575

  17. Genome-Wide Analysis of Yield in Europe: Allelic Effects Vary with Drought and Heat Scenarios1[OPEN

    PubMed Central

    Millet, Emilie J.; Welcker, Claude; Kruijer, Willem; Negro, Sandra; Coupel-Ledru, Aude; Laborde, Jacques; Bauland, Cyril; Praud, Sebastien; Presterl, Thomas; Usadel, Björn; Charcosset, Alain; Van Eeuwijk, Fred; Tardieu, François

    2016-01-01

    Assessing the genetic variability of plant performance under heat and drought scenarios can contribute to reduce the negative effects of climate change. We propose here an approach that consisted of (1) clustering time courses of environmental variables simulated by a crop model in current (35 years × 55 sites) and future conditions into six scenarios of temperature and water deficit as experienced by maize (Zea mays L.) plants; (2) performing 29 field experiments in contrasting conditions across Europe with 244 maize hybrids; (3) assigning individual experiments to scenarios based on environmental conditions as measured in each field experiment; frequencies of temperature scenarios in our experiments corresponded to future heat scenarios (+5°C); (4) analyzing the genetic variation of plant performance for each environmental scenario. Forty-eight quantitative trait loci (QTLs) of yield were identified by association genetics using a multi-environment multi-locus model. Eight and twelve QTLs were associated to tolerances to heat and drought stresses because they were specific to hot and dry scenarios, respectively, with low or even negative allelic effects in favorable scenarios. Twenty-four QTLs improved yield in favorable conditions but showed nonsignificant effects under stress; they were therefore associated with higher sensitivity. Our approach showed a pattern of QTL effects expressed as functions of environmental variables and scenarios, allowing us to suggest hypotheses for mechanisms and candidate genes underlying each QTL. It can be used for assessing the performance of genotypes and the contribution of genomic regions under current and future stress situations and to accelerate breeding for drought-prone environments. PMID:27436830

  18. Behavioral effects of pentobarbital, lorazepam, ethanol and chlorpromazine substitution in pentobarbital-dependent baboons.

    PubMed

    Lamb, R J; Griffiths, R R

    1993-04-01

    Baboons were given continuous intragastric infusions of 100 mg/kg/day of pentobarbital before and during these experiments. The baboons responded under a fixed-ratio (FR) 30-response schedule of food presentation from 10:00 A.M. of one day to 8:00 A.M. of the next day. Terminating pentobarbital administration (i.e., substituting water for pentobarbital) from 8:00 A.M. of one day to 8:00 A.M. of the next day produced large decreases in the number of pellets earned. Repeated 24-h terminations of pentobarbital administration at 1-week intervals produced similar decreases in the pellets earned. In another experiment, the effects of terminating pentobarbital administration for several days were examined. The number of pellets earned decreased within 2 h of terminating pentobarbital administration was maximally suppressed during the first day, and recovered over 3 to 5 days. When different doses of pentobarbital were substituted for 24 h, the disruption of responding seen after pentobarbital termination was attenuated in a dose-dependent manner. In another experiment, the effects of substituting lorazepam, ethanol or chlorpromazine for pentobarbital for 24 h were examined. Lorazepam produced a dose-dependent attenuation of the effects of pentobarbital termination, whereas ethanol did not. Chlorpromazine did not attenuate the effects of pentobarbital termination in two of the three baboons tested, and produced erratic results in the third.

  19. Stress effects on complex permeability spectra of Mn-substituted cobalt ferrite

    NASA Astrophysics Data System (ADS)

    Lo, C. C. H.; Fan, B.

    2013-05-01

    The effects of axial applied stresses on the magnetization processes in Mn-substituted cobalt ferrite (CoMnxFe2-xO4 with x = 0 to 0.4) toroids have been studied by measuring the circumferential complex permeability spectra μ* = μ' - iμ″ from 1 kHz to 15 MHz. The μ* spectra were described using a dispersion equation to determine the relative susceptibilities due to domain wall motion (χD0) and magnetization rotation (χS0). Mn-substitution into cobalt ferrite was found to reduce the magnetocrystalline anisotropy and hence the susceptibility is increased. Under axial compressive stresses, χD0 and χS0 of all samples decrease. The Mn-substituted samples with x = 0.2 and 0.3 show larger reductions in χD0 and χS0 than the pure cobalt ferrite. The stress effects on χS0 and the dependence of the magnetomechanical effect on Mn content were reproduced in model calculations by taking into account the combined effects of stress-induced and magnetocrystalline anisotropies on magnetization rotation.

  20. Effects of Ge substitution on thermoelectric properties of CrSi2

    NASA Astrophysics Data System (ADS)

    Nagai, Hiroki; Takamatsu, Tomohisa; Iijima, Yoshihiko; Hayashi, Kei; Miyazaki, Yuzuru

    2016-11-01

    Polycrystalline Cr(Si1- x Ge x )2 samples were prepared using arc melting and spark plasma sintering methods. Single-phase Cr(Si1- x Ge x )2 samples were obtained for the compositional range of 0 ≤ x ≤ 0.015 and the lattice parameters monotonically increased with x. In the range of single phases, the electrical conductivity and Seebeck coefficient increased and decreased with increasing x, respectively. The partial substitution of Ge effectively reduced the thermal conductivity to ˜80%, which resulted in the increase in the ZT of Cr(Si1- x Ge x )2 samples from 0.16 (x = 0) to 0.25 (x = 0.015) at 600 K. From the results of first-principles calculation for transport properties, it can be concluded that the origin of the increase in electrical conductivity and the decrease in Seebeck coefficient of Ge-substituted samples is the decrease in carrier effective mass.

  1. DFT study of the effect of substitution on the molecular structure of copper phthalocyanine

    NASA Astrophysics Data System (ADS)

    Kaur, Prabhjot; Sachdeva, Ritika; Singh, Sukhwinder; Saini, G. S. S.

    2016-05-01

    To study the effect of sulfonic acid group as substituent on the molecular structure of an organic compound copper Phthalocyanine, the optimized geometry, mulliken charges, energies and dipole momemts of copper phthalocyanine and copper phthalocyaninetetrasulfonic acid tetra sodium salt have been investigated using density functional theory. Also to predict the change in reactive sites after substitution, molecular electrostatic potential maps for both the molecules have been calculated.

  2. Computational predictors fail to identify amino acid substitution effects at rheostat positions

    PubMed Central

    Miller, M.; Bromberg, Y.; Swint-Kruse, L.

    2017-01-01

    Many computational approaches exist for predicting the effects of amino acid substitutions. Here, we considered whether the protein sequence position class – rheostat or toggle – affects these predictions. The classes are defined as follows: experimentally evaluated effects of amino acid substitutions at toggle positions are binary, while rheostat positions show progressive changes. For substitutions in the LacI protein, all evaluated methods failed two key expectations: toggle neutrals were incorrectly predicted as more non-neutral than rheostat non-neutrals, while toggle and rheostat neutrals were incorrectly predicted to be different. However, toggle non-neutrals were distinct from rheostat neutrals. Since many toggle positions are conserved, and most rheostats are not, predictors appear to annotate position conservation better than mutational effect. This finding can explain the well-known observation that predictors assign disproportionate weight to conservation, as well as the field’s inability to improve predictor performance. Thus, building reliable predictors requires distinguishing between rheostat and toggle positions. PMID:28134345

  3. Identification of new primer binding site mutations at TH01 and D13S317 loci and determination of their corresponding STR alleles by allele-specific PCR.

    PubMed

    Li, Fengrui; Xuan, Jinfeng; Xing, Jiaxin; Ding, Mei; Wang, Baojie; Pang, Hao

    2014-01-01

    Several commercial multiplex PCR kits for the amplification of short tandem repeat (STR) loci have been extensively applied in forensic genetics. Consequently, large numbers of samples have been genotyped, and the number of discordant genotypes observed has also increased. We observed allele dropout with two novel alleles at the STR loci TH01 and D13S317 during paternity testing using the AmpFℓSTR Identifiler PCR Amplification Kit. The lost alleles reappeared when alternative PCR primer pairs were used. A sequence analysis revealed a G-to-A substitution 82 bases downstream of the last TCAT motif of the repeat region at the TH01 locus (GenBank accession: D00269) and a G-to-T substitution 90 bases upstream of the first TATC motif of the repeat region at the D13S317 locus (GenBank accession: G09017). The frequencies of these two point mutations were subsequently investigated in the Chinese population using sequence-specific primer PCR (SSP-PCR), but neither of these mutations was detected in any of the samples tested. In addition, the DNA samples in which the mutations were identified were amplified to type the point mutations by SSP-PCR to determine the corresponding STR alleles at the two loci. Subsequently, the amplified PCR products with different point mutations and STR repeat numbers were directly sequenced because this strategy overcomes the appearance overlapping peaks generated by different STR alleles and accurately characterizes genotypes. Thus, our findings not only provide useful information for DNA databases and forensic identification but also establish an effective strategy for typing STR alleles with primer binding site mutations.

  4. Dramatic effects of halogen substitution and solvent on the rates and mechanisms of nucleophilic substitution reactions of aziridines.

    PubMed

    Banks, Harold D

    2008-04-04

    In a previous study we reported that fluorine substitution at the carbon positions of aziridine results in profound enhancements of the rate of reaction with ammonia, a typical nucleophile, in the gas phase. In this study the investigation is extended to include chloro- and bromoaziridines. Because syntheses are largely performed in the condensed phase, the present computational investigation [(MP2(Full)/6-311++G(d,p)//MP2(Full)/6-31+G(d) level] was conducted with three typical solvents that cover a wide range of polarity: THF, CH3CN, and H2O. Nucleophiles can react with haloaziridines 1 by displacing a substituted amide ion by means of an SN2 mechanism (pathway a), producing 1,2-diaminohaloethanes (from the initially formed dipolar species 2). Alternatively, a rearrangement mechanism involving rate-determining departure of a halide ion (pathway b) to form an imidoyl halide, 3, is possible. Transition-state theory was used to compute relative reaction rates of these mechanistic possibilities and to assess the role of the halogen substituents and the reaction solvent. Gas-phase results provided the basis of mechanistic insights that were more apparent in the absence of intermolecular interactions. Fluoroaziridines were found to react at accelerated rates relative to aziridine exclusively by means of the a Menshutkin-type mechanism (SN2) in each solvent tested, while the reactions of the chloro- and bromoaziridines could be directed toward 2 in the highly nonpolar solvent, cyclohexane, or toward 3 in the more polar solvents. An assessment is made of the feasibility of using this chemistry of the haloazirdines in the synthetic laboratory.

  5. Exploring the Effect of Sequence Length and Composition on Allele-Selective Inhibition of Human Huntingtin Expression by Single-Stranded Silencing RNAs

    PubMed Central

    Hu, Jiaxin; Liu, Jing; Yu, Dongbo; Aiba, Yuichiro; Lee, Suheung; Pendergraff, Hannah; Boubaker, Jihane; Artates, Jonathan W.; Lagier-Tourenne, Clotilde; Lima, Walt F.; Swayze, Eric E.; Prakash, Thazha P.

    2014-01-01

    Mutant huntingtin (HTT) protein is the cause of Huntington's disease (HD), an incurable neurological disorder. Almost all patients are heterozygous for mutant HTT and approaches that reduce levels of mutant HTT while leaving expression of wild-type HTT intact might be ideal options for therapeutic development. We have developed several allele-selective strategies for silencing HTT, including single-stranded silencing RNAs (ss-siRNAs). ss-siRNAs are oligonucleotides containing chemical modifications that permit action through the RNA interference (RNAi) pathway. Modified ss-siRNAs chosen to test the effects of varying oligomer length, lipid modification, the introduction of mismatched bases, and variation of chemical modification. We find that several modified ss-siRNA are potent and allele-selective inhibitors of HTT expression. An ss-siRNA with three mismatched bases relative to the CAG repeat was an allele-selective inhibitor of HTT expression in the HdhQ175 mouse model. Multiple allele-selective ss-siRNAs provide a wide platform of modifications to draw on for further optimization and therapeutic development. Our data provide insights into how ss-siRNAs can be modified to improve their properties and facilitate the discovery of the lead compounds necessary for further development. PMID:24694346

  6. High-resolution melting analysis of cDNA-derived PCR amplicons for rapid and cost-effective identification of novel alleles in barley.

    PubMed

    Hofinger, Bernhard J; Jing, Hai-Chun; Hammond-Kosack, Kim E; Kanyuka, Kostya

    2009-09-01

    An original method has been established for the identification of novel alleles of eukaryotic translation initiation factor 4E (eIF4E) gene, which is required for resistance to agronomically important bymoviruses, in barley germplasm. This method involves scanning for sequence variations in cDNA-derived PCR amplicons using High-resolution melting (HRM) followed by direct Sanger sequencing of only those amplicons which were predicted to carry nucleotide changes. HRM is a simple, cost-effective, rapid and high-throughput assay, which so far has only been widely used in clinical pathology for molecular diagnostic of diseases and patient genotyping. Application of HRM allowed significant reduction in the amount of expensive Sanger sequencing required for allele mining in plants. The method described here involved an investigation of total cDNA rather than genomic DNA, thus permitting the analyses of shorter (up to 300-bp) and fewer overlapping amplicons to cover the coding sequence. This strategy further reduced the allele mining costs. The sensitivity and accuracy of HRM for predicting genotypes carrying a wide range of nucleotide polymorphisms in eIF4E approached 100%. Results of the current study are promising and suggest that this method could also potentially be applied to the discovery of superior alleles controlling other important traits in barley as well in other model and crop plant species.

  7. Polymorphism of the bovine POU1F1 gene: allele frequencies and effects on milk production in three Iranian native breeds and Holstein cattle of Iran.

    PubMed

    Zakizadeh, S; Reissmann, M; Rahimi, G; Javaremi, A Nejati; Reinecke, P; Mirae-Ashtiani, S R; Shahrbabak, M Moradi

    2007-08-01

    The aim of this study was to estimate the allele frequencies in polymorphic site of exon six of POU1F1 gene in three Iranian native and Holstein cattle. Genomic DNA was extracted from 3 Iranian native cattle breeds, including 97 Mazandarani, 87 Sarabi, 112 Golpaygani and also 110 Holstein cattle. A 451 bp fragment of intron 5 and exon 6 were amplified and digested with HinfI restriction enzyme. Frequencies of allele A were 0.37, 0.27, 0.34 and 0.21 for Mazandarani, Sarabi, Golpaygani and Holstein cattle, respectively. Significant differences in genotype frequencies were found between Mazandarani or Golpaygani and Holstein cattle. No significant differences in genotype frequencies were found between Sarabi and Holstein cattle. Transition A to G in nucleotide 1256 is responsible for HinfI(-) allele. No significant association was observed between POU1F1 polymorphism and milk production. Differences in allelic frequency between native Bos indicus breeds (Mazandarani, Golpaygani) and Holstein at the present study might be due to differences in origin breeds, low number of samples and/or as the effect of natural selection in native breeds.

  8. Effect of the degree of substitution in the transition temperatures and hydrophobicity of hydroxypropyl cellulose esters.

    PubMed

    López-Velázquez, Delia; Hernández-Sosa, Armando R; Pérez, Ernesto

    2015-07-10

    We have synthesized and characterized five members of a homologous series of side chain polymers of hydroxypropyl cellulose esters obtained by homogeneous esterification with 6-[4'-(ethoxycarbonyl)biphenyl-4-yloxy]hexanoic acid. Two acylation procedures were studied. One procedure involved the acid chloride derivative and the other one was the activation of that acid with N,N'-carbonyldiimidazol. The second method yielded esters with higher degree of substitution, DS¯. The esters, with DS¯ ranging from 26 to about 66%, were characterized by FTIR, NMR, solution viscometry, TGA, DSC, polarized optical microscopy, and X-ray diffraction, in order to study the effect of the degree of substitution on the hydrophobicity, on the transition temperatures and on their potential liquid crystal properties. It has been found that the hydrophobicity and the transition temperatures of the HPC derivatives are very much dependent on the degree of acylation. The esters with high DS¯ values showed liquid crystal properties.

  9. Substitution for chromium in 304 stainless steel. [effects on oxidation and corrosion resistance

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.; Barrett, C. A.

    1978-01-01

    An investigation was conducted to determine the effects of substituting less strategic elements for Cr on oxidation and corrosion resistance of AISI 304 stainless steel. Cyclic oxidation resistance was evaluated at 870 C. Corrosion resistance was determined by exposure of specimens to a boiling copper-rich solution of copper sulfate and sulfuric acid. Alloy substitutes for Cr included Al, Mn, Mo, Si, Ti, V, Y, and misch metal. A level of about 12% Cr was the minimum amount of Cr required for adequate oxidation and corrosion resistance in the modified composition 304 stainless steels. This represents a Cr saving of 33 percent. Two alloys containing 12% Cr plus 2% Al plus 2% Mo and 12% Cr plus 2.65% Si were identified which exhibited oxidation and corrosion resistance comparable to AISI 304 stainless steel.

  10. Effect of Allelic Variation at the Glu-3/Gli-1 Loci on Breadmaking Quality Parameters in Hexaploid Wheat (Triticum aestivum L.)

    PubMed Central

    Bonafede, Marcos D.; Tranquilli, Gabriela; Pflüger, Laura A.; Peña, Roberto J.; Dubcovsky, Jorge

    2016-01-01

    Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program we developed a set of nine near isogenic lines (NILs) including different Glu-A3/GliA-1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3iMan alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3iChu were consistently associated with weak gluten and low quality values. The value of different Glu3/Gli-1 allele combinations to improve breadmaking quality is discussed. PMID:27818572

  11. Effect of Allelic Variation at the Glu-3/Gli-1 Loci on Breadmaking Quality Parameters in Hexaploid Wheat (Triticum aestivum L.).

    PubMed

    Bonafede, Marcos D; Tranquilli, Gabriela; Pflüger, Laura A; Peña, Roberto J; Dubcovsky, Jorge

    2015-03-01

    Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program we developed a set of nine near isogenic lines (NILs) including different Glu-A3/GliA-1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3iMan alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3iChu were consistently associated with weak gluten and low quality values. The value of different Glu3/Gli-1 allele combinations to improve breadmaking quality is discussed.

  12. Effect of aluminum substitution on structural and electromagnetic properties of nanocrystalline MgCuMn ferrites

    SciTech Connect

    Ramesh, T. E-mail: ramanasarabu@gmail.com; Kumar, S. Senthil; Shinde, R. S.; Murthy, S. R.

    2015-06-24

    The effect of substitution of nonmagnetic Al{sup 3+} ions on the structural and electromagnetic properties were studied in nanocrystalline ferrite series of Mg{sub 0.8}Cu{sub 0.2}Al{sub x}Fe{sub 1.95-x}Mn{sub 0.05}O{sub 4} where x varies 0-0.4 in steps of 0.1. This series was synthesized by using microwave hydrothermal method. The nanocrystalline ferrite phase was observed at temperature 150°C/40 min. Synthesized powders were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The synthesized powders were densified using microwave sintering method at 950°C/40 min. The sintered samples were characterized using XRD. Surface morphology was observed by using field effective scanning electron microscopy (FESEM). The electrical and magnetic properties were measured at room temperature. These results led us to interfere that the values of d.c resistivity increases and dielectric constant, initial permeability, saturation magnetization and Curie temperature were observed to be decreased with the substitution of Al{sup 3+} ions with those of Fe{sup 3+}. The low dielectric and magnetic losses and low magnetization exhibited by aluminum substituted MgCuMn ferrites makes them find applications in microwave devices.

  13. Spin canting effect and microwave absorption properties of Sm-Mn substituted nanosized material

    NASA Astrophysics Data System (ADS)

    Sadiq, Imran; Naseem, Shahzad; Naeem Ashiq, Muhammad; Asif Iqbal, M.; Ali, Irshad; Khan, M. A.; Niaz, Shanawar; Rana, M. U.

    2015-12-01

    In order to understand the substitutional effect of rare earth element Sm3+ and divalent Mn2+ on structural, magnetic and microwave absorption properties of hexagonal ferrites, a series of Sr2-x Smx Ni2 Fe28-yMnyO46 X-type hexagonal ferrites with concentration (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10 and y=0, 0.1, 0.2, 0.3, 0.4, 0.5) was synthesized by the sol-gel method. The XRD analysis shows that the material crystallized into single X-type hexagonal phase. The absorption bands at low wave number in FTIR curves are the characteristics of the X-type hexagonal ferrites. Decreasing trend in the magnetic properties with the substitution of Sm-Mn contents was also observed, which may be attributed to the oxidation of Mn2+ ions into Mn3+ ions and spin canting effect of rare earth element Sm3+. The reflection loss peak shifted towards the low frequency and microwave absorption properties of the material enhanced with the substitution of Sm-Mn contents which reflects its applications in super high frequency (SHF) devices. The attenuation constant curves are in good agreement with the reflection loss peak.

  14. Equilibrium clumped-isotope effects in doubly substituted isotopologues of ethane

    NASA Astrophysics Data System (ADS)

    Webb, Michael A.; Wang, Yimin; Braams, Bastiaan J.; Bowman, Joel M.; Miller, Thomas F.

    2017-01-01

    We combine path-integral Monte Carlo methods with a new intramolecular potential energy surface to quantify the equilibrium enrichment of doubly substituted ethane isotopologues due to clumped-isotope effects. Ethane represents the simplest molecule to simultaneously exhibit 13C-13C, 13C-D, and D-D clumped-isotope effects, and the analysis of corresponding signatures may provide useful geochemical and biogeochemical proxies of formation temperatures or reaction pathways. Utilizing path-integral statistical mechanics, we predict equilibrium fractionation factors that fully incorporate nuclear quantum effects, such as anharmonicity and rotational-vibrational coupling which are typically neglected by the widely used Urey model. The magnitude of the calculated fractionation factors for the doubly substituted ethane isotopologues indicates that isotopic clumping can be observed if rare-isotope substitutions are separated by up to three chemical bonds, but the diminishing strength of these effects suggests that enrichment at further separations will be negligible. The Urey model systematically underestimates enrichment due to 13C-D and D-D clumped-isotope effects in ethane, leading to small relative errors in the apparent equilibrium temperature, ranging from 5 K at 273.15 K to 30 K at 873.15 K. We additionally note that the rotameric dependence of isotopologue enrichment must be carefully considered when using the Urey model, whereas the path-integral calculations automatically account for such effects due to configurational sampling. These findings are of direct relevance to future clumped-isotope studies of ethane, as well as studies of 13C-13C, 13C-D, and D-D clumped-isotope effects in other hydrocarbons.

  15. Effective atomic numbers of some tissue substitutes by different methods: A comparative study.

    PubMed

    Singh, Vishwanath P; Badiger, N M

    2014-01-01

    Effective atomic numbers of some human organ tissue substitutes such as polyethylene terephthalate, red articulation wax, paraffin 1, paraffin 2, bolus, pitch, polyphenylene sulfide, polysulfone, polyvinylchloride, and modeling clay have been calculated by four different methods like Auto-Zeff, direct, interpolation, and power law. It was found that the effective atomic numbers computed by Auto-Zeff, direct and interpolation methods were in good agreement for intermediate energy region (0.1 MeV < E < 5 MeV) where the Compton interaction dominates. A large difference in effective atomic numbers by direct method and Auto-Zeff was observed in photo-electric and pair-production regions. Effective atomic numbers computed by power law were found to be close to direct method in photo-electric absorption region. The Auto-Zeff, direct and interpolation methods were found to be in good agreement for computation of effective atomic numbers in intermediate energy region (100 keV < E < 10 MeV). The direct method was found to be appropriate method for computation of effective atomic numbers in photo-electric region (10 keV < E < 100 keV). The tissue equivalence of the tissue substitutes is possible to represent by any method for computation of effective atomic number mentioned in the present study. An accurate estimation of Rayleigh scattering is required to eliminate effect of molecular, chemical, or crystalline environment of the atom for estimation of gamma interaction parameters.

  16. Effective atomic numbers of some tissue substitutes by different methods: A comparative study

    PubMed Central

    Singh, Vishwanath P.; Badiger, N. M.

    2014-01-01

    Effective atomic numbers of some human organ tissue substitutes such as polyethylene terephthalate, red articulation wax, paraffin 1, paraffin 2, bolus, pitch, polyphenylene sulfide, polysulfone, polyvinylchloride, and modeling clay have been calculated by four different methods like Auto-Zeff, direct, interpolation, and power law. It was found that the effective atomic numbers computed by Auto-Zeff, direct and interpolation methods were in good agreement for intermediate energy region (0.1 MeV < E < 5 MeV) where the Compton interaction dominates. A large difference in effective atomic numbers by direct method and Auto-Zeff was observed in photo-electric and pair-production regions. Effective atomic numbers computed by power law were found to be close to direct method in photo-electric absorption region. The Auto-Zeff, direct and interpolation methods were found to be in good agreement for computation of effective atomic numbers in intermediate energy region (100 keV < E < 10 MeV). The direct method was found to be appropriate method for computation of effective atomic numbers in photo-electric region (10 keV < E < 100 keV). The tissue equivalence of the tissue substitutes is possible to represent by any method for computation of effective atomic number mentioned in the present study. An accurate estimation of Rayleigh scattering is required to eliminate effect of molecular, chemical, or crystalline environment of the atom for estimation of gamma interaction parameters. PMID:24600169

  17. The two gap transitions in Ge1 -xSnx : Effect of non-substitutional complex defects

    NASA Astrophysics Data System (ADS)

    Querales-Flores, J. D.; Ventura, C. I.; Fuhr, J. D.; Barrio, R. A.

    2016-09-01

    The existence of non-substitutional β-Sn defects in Ge1 -xSnx alloys was confirmed by emission channeling experiments [Decoster et al., Phys. Rev. B 81, 155204 (2010)], which established that, although most Sn enters substitutionally (α-Sn) in the Ge lattice, a second significant fraction corresponds to the Sn-vacancy defect complex in the split-vacancy configuration (β-Sn), in agreement with our previous theoretical study [Ventura et al., Phys. Rev. B 79, 155202 (2009)]. Here, we present the electronic structure calculations for Ge1 -xSnx , including the substitutional α-Sn as well as the non-substitutional β-Sn defects. To include the presence of the non-substitutional complex defects in the electronic structure calculation for this multi-orbital alloy problem, we extended the approach for the purely substitutional alloy by Jenkins and Dow [Phys. Rev. B 36, 7994 (1987)]. We employed an effective substitutional two-site cluster equivalent to the real non-substitutional β-Sn defect, which was determined by a Green's functions calculation. We then calculated the electronic structure of the effective alloy purely in terms of substitutional defects, embedding the effective substitutional clusters in the lattice. Our results describe the two transitions of the fundamental gap of Ge1 -xSnx as a function of the total Sn-concentration: namely, from an indirect to a direct gap, first, and the metallization transition at a higher x. They also highlight the role of β-Sn in the reduction of the concentration range, which corresponds to the direct-gap phase of this alloy of interest for the optoelectronics applications.

  18. The incidence and effect on total tuber carotenoids of a recessive zeaxanthin epoxidase allele in yellow fleshed potatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zeaxanthin epoxidase (Zep) is one of at least two genes important for the incidence and amount of carotenoids in yellow-fleshed potato. The recessive allele of the gene encoding zeaxanthin epoxidase (Zep) has previously been shown to to inhibit the conversion of the xanthophyll zeaxanthin to other,...

  19. Structural insights into the effects of charge-reversal substitutions at the surface of horseradish peroxidase

    PubMed Central

    Navapour, Leila; Mogharrab, Navid

    2016-01-01

    Horseradish peroxidase (HRP), has gained significant interests in biotechnology, especially in biosensor field and diagnostic test kits. Hence, its solvent-exposed lysine residues 174, 232, and 241 have been frequently modified with the aim of improving its stability and catalytic efficiency. In this computational study, we investigated the effects of Lys-to-Glu substitutions on HRP structure to model charge-reversal manipulations at the enzyme surface. Simulation results implied that upon these substitutions, the number of stable hydrogen bonds and α-helical content of HRP are increased and the proximal Ca2+ binding pocket becomes more integrated. The results revealed that although Glu174-heme hydrogen bond is lost after mutation, formation of a new hydrogen bonding network contributes to the stability of heme-protein linkage. Together, it may be concluded that these substitutions enhance the stability of the protein moiety as well as the heme-protein non-covalent interactions. In the enzyme active site, we observed increased accessibility of peroxide binding site and heme prosthetic group to the peroxide and aromatic substrates, respectively. Results also demonstrated that the bottleneck entry of the peroxide-binding site has become wider and more flexible upon substitutions. Moreover, the hydrophobic patch functioning as a binding site or trap for reducing aromatic substrates is more extended in mutated enzyme. These observations suggest that the reactivity of the enzyme to its substrates has increased. Together, the results of this simulation study could provide possible structural clues to explain those experimental observations in which the protein stability achieved upon manipulation of charge distribution on protein surface. PMID:28097171

  20. Solvent effects on the electronic absorption spectra and acid strength of some substituted pyridinols

    NASA Astrophysics Data System (ADS)

    Hashem, Elham Y.; Saleh, Magda S.

    2002-01-01

    The electronic absorption spectra of some substituted pyridinols in organic solvents of different polarities are studied. Also, the solvent effects on the intramolecular charge transfer bands are discussed using various solvent parameters. The acid-base equilibria of the compounds used are studied spectrophotometrically in various mixed aqueous solvents at 25 °C and 0.1 M ionic strength (NaClO 4). Furthermore, the influence of the solvents on the dissociation constants and tautomeric equilibria of a pyridinol derivatives are discussed. The effect of molecular structure of the pyridinols on the p K's is also examined.

  1. Heteroatom substituted organic/polymeric semiconductors and their applications in field-effect transistors.

    PubMed

    Zhang, Weifeng; Liu, Yunqi; Yu, Gui

    2014-10-29

    Organic/polymeric semiconductors are mainly composed of aromatic systems including phenyl, vinyl, alkynyl, thienyl, and other isoelectric groups, which are constructed of carbon, hydrogen, and so-called 'hereroatoms' including chalcogen, nitrogen, and halogen atoms etc. The introduction of heteroatoms could yield different electronic properties by influencing the molecular geometry, the HOMO and LUMO energy levels, intermolecular interactions and so on. In this Research News article, we provide a brief review of the effect of heteroatoms and recent developments in heteroatom substituted organic/polymeric semiconductors, focusing especially on their application in field-effect transistors.

  2. Allelic genealogies in sporophytic self-incompatibility systems in plants.

    PubMed Central

    Schierup, M H; Vekemans, X; Christiansen, F B

    1998-01-01

    Expectations for the time scale and structure of allelic genealogies in finite populations are formed under three models of sporophytic self-incompatibility. The models differ in the dominance interactions among the alleles that determine the self-incompatibility phenotype: In the SSIcod model, alleles act codominantly in both pollen and style, in the SSIdom model, alleles form a dominance hierarchy, and in SSIdomcod, alleles are codominant in the style and show a dominance hierarchy in the pollen. Coalescence times of alleles rarely differ more than threefold from those under gametophytic self-incompatibility, and transspecific polymorphism is therefore expected to be equally common. The previously reported directional turnover process of alleles in the SSIdomcod model results in coalescence times lower and substitution rates higher than those in the other models. The SSIdom model assumes strong asymmetries in allelic action, and the most recessive extant allele is likely to be the most recent common ancestor. Despite these asymmetries, the expected shape of the allele genealogies does not deviate markedly from the shape of a neutral gene genealogy. The application of the results to sequence surveys of alleles, including interspecific comparisons, is discussed. PMID:9799270

  3. Isolation and Genetic Characterization of Mother-of-Snow-White, a Maternal Effect Allele Affecting Laterality and Lateralized Behaviors in Zebrafish

    PubMed Central

    Domenichini, Alice; Dadda, Marco; Facchin, Lucilla; Bisazza, Angelo; Argenton, Francesco

    2011-01-01

    In the present work we report evidence compatible with a maternal effect allele affecting left-right development and functional lateralization in vertebrates. Our study demonstrates that the increased frequency of reversed brain asymmetries in a zebrafish line isolated through a behavioral assay is due to selection of mother-of-snow-white (msw), a maternal effect allele involved in early stages of left-right development in zebrafish. msw homozygous females could be identified by screening of their progeny for the position of the parapineal organ because in about 50% of their offspring we found an altered, either bilateral or right-sided, expression of lefty1 and spaw. Deeper investigations at earlier stages of development revealed that msw is involved in the specification and differentiation of precursors of the Kupffer's vesicle, a structure homologous to the mammalian node. To test the hypothesis that msw, by controlling Kupffer's vesicle morphogenesis, controls lateralized behaviors related to diencephalic asymmetries, we analyzed left- and right-parapineal offspring in a “viewing test”. As a result, left- and right-parapineal individuals showed opposite and complementary eye preference when scrutinizing a model predator, and a different degree of lateralization when scrutinizing a virtual companion. As maternal effect genes are expected to evolve more rapidly when compared to zygotic ones, our results highlight the driving force of maternal effect alleles in the evolution of vertebrates behaviors. PMID:22022484

  4. Combined effects of current-smoking and the aldehyde dehydrogenase 2*2 allele on the risk of myocardial infarction in Japanese patients.

    PubMed

    Morita, Kazunori; Miyazaki, Hiroko; Saruwatari, Junji; Oniki, Kentaro; Kumagae, Naoki; Tanaka, Takahiro; Kajiwara, Ayami; Otake, Koji; Ogata, Yasuhiro; Arima, Yuichiro; Hokimoto, Seiji; Ogawa, Hisao; Nakagawa, Kazuko

    2015-01-05

    Aldehyde dehydrogenase 2 (ALDH2) detoxifies toxic aldehydes, e.g. acetaldehyde in cigarette smoke; however, the interactive effects between smoking status and the ALDH2 genotype on coronary artery disease (CAD) have not been reported. We investigated the effects of smoking status and the ALDH2 genotype, and assessed their interactive and combined effects on the risk of myocardial infarction (MI) or stable angina (SA), including 221 MI and 175 SA subjects and 473 age- and sex-matched controls without CAD. Current-smoking and the ALDH2*2 allele additively increased the risk of MI (adjusted odds ratio 4.54, 95% confidence interval 2.25-9.15), although this combination was not associated with the risk of SA. This combination also increased the peak creatine kinase (CK) level synergistically in the acute MI (AMI) subjects. Moreover, current-smoking was found to be a significant risk factor for an increased peak CK level in the ALDH2*2 allele carriers (B 2220.2IU/L, p=0.008), but not the non-carriers. Additionally, a synergistic effect of this combination on the triglycerides levels was also found in the AMI subjects. These preliminary findings suggest that the combination of current-smoking and the inactive ALDH2*2 allele may increase the risk of MI additively and the infarct size synergistically.

  5. Effect of cyp2d6*10 allele on the pharmacokinetics of loratadine in chinese subjects.

    PubMed

    Yin, Ophelia Q P; Shi, X J; Tomlinson, B; Chow, Moses S S

    2005-09-01

    Loratadine is known to be a substrate for both CYP3A4 and CYP2D6 based on a previous in vitro study. In view of the large interindividual variability in loratadine pharmacokinetics and the greater genetically determined variability of CYP2D6 activity than of CYP3A4 in vivo, we hypothesized that CYP2D6 polymorphisms may contribute to the pharmacokinetic variability of loratadine. The purpose of this study was to evaluate the effect of CYP2D6 genotype (specifically the CYP2D6*10 allele) on the pharmacokinetics of loratadine in Chinese subjects. Three groups of healthy male Chinese subjects were enrolled: group I, homozygous CYP2D6*1 (*1/*1, n=4); group II, heterozygous CYP2D6*10 (*1/*10 or *2/*10, n=6); and group III, homozygous CYP2D6*10 (*10/*10, n=7) carriers. Each subject received a single oral dose of 20 mg of loratadine under fasting conditions. Multiple blood samples were collected over 48 h, and the plasma concentrations of loratadine and its metabolite desloratadine were determined by high-performance liquid chromatography. In comparing homozygous CYP2D6*10 (group III) to heterozygous CYP2D6*10 (group II) to homozygous CYP2D6*1 (group I) subjects, loratadine oral clearance values were 7.17+/- 2.54 versus 11.06+/-1.70 versus 14.59+/-2.43 l/h/kg, respectively [one-way analysis of variance (ANOVA), p<0.01], and the corresponding metabolic ratios [area under the plasma concentration-time curve (AUC)(desloratadine)/AUC(loratadine)] were 1.55+/-0.73 versus 2.47+/- 0.46 versus 3.32+/- 0.49, respectively (one-way ANOVA, p<0.05), indicating a gene-dose effect. The results demonstrated that CYP2D6 polymorphism prevalent in the Chinese population significantly affected loratadine pharmacokinetics.

  6. An organic cosmo-barometer: Distinct pressure and temperature effects for methyl substituted polycyclic aromatic hydrocarbons

    SciTech Connect

    Montgomery, Wren; Watson, Jonathan S.; Sephton, Mark A.

    2014-04-01

    There are a number of key structures that can be used to reveal the formation and modification history of organic matter in the cosmos. For instance, the susceptibility of organic matter to heat is well documented and the relative thermal stabilities of different isomers can be used as cosmothermometers. Yet despite being an important variable, no previously recognized organic marker of pressure exists. The absence of a pressure marker is unfortunate considering our ability to effectively recognize extraterrestrial organic structures both remotely and in the laboratory. There are a wide variety of pressures in cosmic settings that could potentially be reflected by organic structures. Therefore, to develop an organic cosmic pressure marker, we have used state-of-the-art diamond anvil cell (DAC) and synchrotron-source Fourier transform infrared (FTIR) spectroscopy to reveal the effects of pressure on the substitution patterns for representatives of the commonly encountered methyl substituted naphthalenes, specifically the dimethylnaphthalenes. Interestingly, although temperature and pressure effects are concordant for many isomers, pressure appears to have the opposite effect to heat on the final molecular architecture of the 1,5-dimethylnaphthalene isomer. Our data suggest the possibility of the first pressure parameter or 'cosmo-barometer' (1,5-dimethylnaphthalene/total dimethylnaphthalenes) that can distinguish pressure from thermal effects. Information can be obtained from the new pressure marker either remotely by instrumentation on landers or rovers or directly by laboratory measurement, and its use has relevance for all cases where organic matter, temperature, and pressure interplay in the cosmos.

  7. Efficacious rat model displays non-toxic effect with Korean beechwood creosote: a possible antibiotic substitute.

    PubMed

    Quynh, Anh Nguyen Thai; Sharma, Neelesh; Cho, Kwang Keun; Yeo, Tae Jong; Kim, Ki Beom; Jeong, Chul Yon; Min, Tae Sun; Young, Kim Jae; Kim, Jin Nam; Jeong, Dong-Kee

    2014-05-04

    Wood creosote, an herbal anti-diarrheal and a mixture of major volatile compounds, was tested for its non-toxicological effects, using a rat model, with the objective to use the creosote as an antibiotic substitute. A total of 30 Sprague-Dawley rats were studied to form five groups with 6 rats each. Korea beechwood creosote was supplemented into three test groups with 0.03 g/kg, 0.07 g/kg and 0.1 g/kg body weight/day without antibiotic support, along with a positive control of Apramycin sulphate (at 0.5% of the daily feed) and a negative control. Korean beechwood creosote supplementation showed no negative effect on the body weight gain in comparison to the negative and the positive control groups and the feed conversion ratio was also comparable with that of the control groups. The clinical pathology parameters studied were also under the umbrella of normal range, including liver specific enzymes, blood glucose, total protein, blood urea nitrogen (BUN), which indicated no toxic effect of creosote at the given doses. The non-hepatotoxic effect was also confirmed using hepatic damage specific molecular markers like Tim-p1, Tim-p2 and Tgf-β1. The results suggested that Korean beechwood may be used as antibiotic substitute in weanling pigs feed without any toxic effect on the body. Although the antimicrobial properties of creosote were not absolutely similar to those of apramycin sulphate, they were comparable.

  8. T cell receptor clonotypes modulate the protective effect of HLA class I alleles in HIV-1 infection

    PubMed Central

    Chen, Huabiao; Ndhlovu, Zaza M.; Liu, Dongfang; Porter, Lindsay C.; Fang, Justin W.; Darko, Sam; Brockman, Mark A.; Miura, Toshiyuki; Brumme, Zabrina L.; Schneidewind, Arne; Piechocka-Trocha, Alicja; Cesa, Kevin T.; Sela, Jennifer; Cung, Thai D.; Toth, Ildiko; Pereyra, Florencia; Yu, Xu G.; Douek, Daniel C.; Kaufmann, Daniel E.; Allen, Todd M.; Walker, Bruce D.

    2012-01-01

    Human leukocyte antigen (HLA) B*27 and B*57 are associated with protection against HIV-1 disease progression, yet most persons expressing these alleles are unable to control HIV-1. Here we show that HLA-B*27-restricted CD8+ T cells in controllers and progressors differ in their ability to inhibit virus replication through targeting of the immunodominant Gag epitope. This is associated with distinct TCR clonotypes, characterized by superior control of HIV-1 replication in vitro, greater cross-reactivity against epitope variants, and enhanced perforin delivery. Clonotype-specific differences in antiviral efficacy were also observed for an immunodominant HLA-B*57 restricted response in controllers and progressors. Thus, the efficacy of protective alleles is modulated by specific TCR clonotypes selected in natural infection, providing a functional explanation for divergent HIV-1 outcomes. PMID:22683743

  9. Additive Effects of the Risk Alleles of PNPLA3 and TM6SF2 on Non-alcoholic Fatty Liver Disease (NAFLD) in a Chinese Population

    PubMed Central

    Wang, Xiaoliang; Liu, Zhipeng; Wang, Kai; Wang, Zhaowen; Sun, Xing; Zhong, Lin; Deng, Guilong; Song, Guohe; Sun, Baining; Peng, Zhihai; Liu, Wanqing

    2016-01-01

    Recent genome-wide association studies have identified that variants in or near PNPLA3, NCAN, GCKR, LYPLAL1, and TM6SF2 are significantly associated with non-alcoholic fatty liver disease (NAFLD) in multiple ethnic groups. Studies on their impact on NAFLD in Han Chinese are still limited. In this study, we examined the relevance of these variants to NAFLD in a community-based Han Chinese population and further explored their potential joint effect on NAFLD. Six single nucleotide polymorphisms (SNPs) (PNPLA3 rs738409, rs2294918, NCAN rs2228603, GCKR rs780094, LYPLAL1 rs12137855, and TM6SF2 rs58542926) previously identified in genome-wide analyses, to be associated with NAFLD were genotyped in 384 NAFLD patients and 384 age- and gender-matched healthy controls. We found two out of the six polymorphisms, PNPLA3 rs738409 (OR = 1.52, 95%CI: 1.19–1.96; P = 0.00087) and TM6SF2 rs58542926 (OR = 2.11, 95%CI: 1.34–3.39; P = 0.0016) are independently associated with NAFLD after adjustment for the effects of age, gender, and BMI. Our analysis further demonstrated the strong additive effects of the risk alleles of PNPLA3 and TM6SF2 with an overall significance between the number of risk alleles and NAFLD (OR = 1.64, 95%CI: 1.34–2.01; P = 1.4 × 10-6). The OR for NAFLD increased in an additive manner, with an average increase in OR of 1.52 per additional risk allele. Our results confirmed that the PNPLA3 and TM6SF2 variants were the most significant risk alleles for NAFLD in Chinese population. Therefore, genotyping these two genetic risk factors may help identify individuals with the highest risk of NAFLD. PMID:27532011

  10. Correlation and nuclear distortion effects of Cr-substituted ZnSe.

    PubMed

    Tablero, C

    2007-04-28

    There is a great deal of interest in the effect of the correlation and effect of the atomic distortion in materials with a metallic intermediate band. This band, situated within the semiconductor band gaps, would be split, thus creating two bands, a full one below the Fermi energy and an empty one above it, i.e., a metal-insulator transition. This basic electronic band structure corresponds to intermediate band materials and is characteristic of transparent-conducting oxides, up and down converters, and intermediate band solar cells. A sufficiently high density of Cr in ZnSe substituting the Zn atoms leads to a microscopic intermediate band, in which these effects will be analyzed. A Hubbard term has been included to improve the description of the many-body effect. This term modifies the bandwidth of the intermediate band, the Fermi energy, and breaks the orbital-occupation degeneracy. From the results, the intermediate band is not split within the range of Hubbard term values analyzed and for Cr substituting Zn from 0.463% to 3.125% of Cr atomic concentration.

  11. Chlorine Substituted Acetic Acids and Salts. Effect of Salification on Chlorine-35 NQR

    NASA Astrophysics Data System (ADS)

    David, Serge; Gourdji, Michel; Guibé, Lucien; Péneau, Alain

    1996-06-01

    The NQR of a quadrupolar probe nucleus is often used to investigate the effect of substituent in molecules. The inductive effect, based on a partial charge migration along the molecular skeleton is the only one present in saturated aliphatics, the conjugative effect appearing in conjugated molecules, especially aromatics. As the stepwise charge migration mechanism, formerly used to explain the inductive effect, is now believed obsolete, we have wanted to reexamined the case of chlorine substituted acetic acids and salts. The data in literature was extended by observing reso-nances and determining NQR frequencies in several acids and salts. The present analysis of the salification of mono-, di-and tri-chloroacetic acids, which is equivalent to a deprotonation or the substitution of the acid hydrogen by a negative unit charge, shows that a model based on the polarization of the chlorine atom(s) by the carboxyle group is consistent with experimental results: the polarization energy appears to be proportional to the NQR frequency shifts; experimental data show a correlation between the NQR frequency shifts accompanying salification and the variations of the intrinsic acidity measured in the gas phase; this, in turn shows that there is a proportionality between the polarization energy and the variations in the acid free enthalpy of dissociation. From the comparison between fluorine, chlorine, bromine and iodine, it also appears that an alternative mechanism, the polarization of the carboxyl group by the halogen, would be important only in the case of the fluoroacetic acid.

  12. The effect of different alleles at the r locus on the synthesis of seed storage proteins in Pisum sativum.

    PubMed

    Turner, S R; Barratt, D H; Casey, R

    1990-05-01

    Rocket immunoelectrophoresis was used to measure the accumulation of storage proteins in developing cotyledons of two Pisum sativum (pea) genotypes, that were close to isogenic except for the nature of the allele at the r locus. There was a marked decrease in legumin accumulation in the rr (wrinkled-seeded) genotype compared to the RR (round-seeded) genotype. The accumulation of vicilin did not differ greatly between the two genotypes. Pulse-labelling studies indicated that the differences in rates of accumulation of legumin between the rr and RR genotypes were a consequence of differences in rates of protein synthesis. Measurements of relative amounts of specific mRNAs, using cDNA clones as probes, showed lower amounts of legumin mRNA in developing cotyledons of the rr, compared to the RR, genotype. Both vicilin mRNAs and convicilin mRNA, the latter of which shows a similar temporal pattern of expression to those of the major legumin species, are relatively unaffected by the nature of the allele at the r locus. Nuclear run-on transcription experiments indicated no differences in the rate of synthesis of legumin transcripts in the rr and RR near-isolines. The consequences of homozygosity for the r allele on storage protein mRNA levels in vitro may be mimicked by manipulating the sucrose concentration of the culture medium.

  13. Effect of processing temperature on the properties of nanophase Fe-substituted Hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Kathriarachchi, Vindu Wathsala

    The effect of processing temperature on the crystal structure properties of the Fe-substituted Hydroxyapatite (Fe-HAp) was studied by using the Rietveld refinement method of powder x-ray (XRD) and neutron diffraction (NPD) patterns. Superconducting QUantum Interference Device (SQUID) magnetometry, transmission electron microscopy (TEM) and x-ray fluorescence spectroscopy (XRF) were used to study the magnetic properties, particle morphology and chemical composition of the prepared samples. Two sets of samples of chemical formula Ca5- xFex(PO4)3OH were prepared with x = 0, 0.05, 0.1, 0.2 and 0.3 by using processing temperatures of 37°C and 80°C, following a two-step co-precipitation method. A single phase HAp was identified in samples with x = 0 and 0.05. Processing temperature affects the type and percentage of secondary phases: hematite was detected in samples prepared at 37°C with x ≥ 0.1, hematite and maghemite were detected in samples prepared at 80°C with x = 0.2 and 0.3. Rietveld refinements of NPD and XRD patterns showed that the a lattice constants are greater in Fe-substituted samples prepared at 37°C, whereas the c lattice constants are greater in the 80°C samples for x ≥ 0.05. Fe preferentially substitutes at the Ca2 site in the 80°C samples, whereas Ca1 is the preferred substitution site in the 37°C samples. Fe substitution results to a decrease of the lattice constants at both preparation temperatures. The ratios Fe/(Fe + Ca) of the refined atomic fractions of the samples prepared at 80°C are greater than those of the 37°C samples. Further, more secondary phases form in samples prepared at 37°C compared to 80°C samples. The magnetic measurements reveal that pure HAp is diamagnetic, whereas samples with x = 0.05 and 0.1 are paramagnetic. Samples with x = 0.3 showed superparamagnetic behavior based on ZFC and FC measurements. Similar hysteresis loops in samples x = 0.2 and 0.3 indicate that the samples with x = 0.2 may show

  14. Computational study of gas-phase molecular structure and substitution effects in para-substituted nickelabenzenes ( p-XC5H4)Ni(CO)2F

    NASA Astrophysics Data System (ADS)

    Hakimioun, Amir Hossein; Makkipour, Peymaneh; Ghiasi, Hossein; Pasdar, Hoda

    2015-09-01

    The structure and properties of nickelabenzene complex were examined by the Modified Perdew-Wang Exchange and Correlation method (mpw1pw91). The para-substitutions effect on the structure, frontier orbital energies, aromaticity and electronic spectra has been studied. Nucleus independent chemical shift (NICS) values show that these species are aromatic. Time dependent density functional theory (TD-DFT) was used to calculate the energy, oscillator strength and absorption maxima wavelength (λmax) of various electronic transitions and their nature within molecules.

  15. The effect of substitution therapy on symptoms in patients with hypothyroidism following treatment for laryngeal and hypopharyngeal carcinomas.

    PubMed

    Lo Galbo, A M; Verdonck-De Leeuw, I M; Lips, P; Kuik, D J; Leemans, C R; De Bree, R

    2013-08-01

    Hypothyroidism is a well-known complication following treatment of laryngeal or hypopharyngeal carcinomas, and may cause various psychological and physical problems that negatively affect quality of life. The aim of this study was to evaluate the effect of substitution therapy on symptoms in patients with hypothyroidism. A study-specific questionnaire on physical and psychological problems (before and after substitution therapy) was sent to 70 patients who had been treated between 1977 and 2008 with clinical or subclinical hypothyroidism. Ninety-four percent returned the questionnaire. Symptoms on energy levels were reported most often (67% always tired and 70% lack of energy). Moodiness and emotional and physical symptoms were reported more often in substituted (sub)clinical hypothyroidism. Substitution therapy resulted in an improvement of energy (P = 0.013), sense of general interest and enjoyment (P = 0.022) and a reduction of puffy face (P = 0.041). Most symptoms in patients with thyroid dysfunction do not improve after substitution therapy. Nevertheless, due to its impact on health-related quality of life and the low burden of substitution therapy, screening for hypothyroidism and subsequent substitution therapy remains important.

  16. How to Be an Effective Substitute Teacher in the Spanish Classroom

    ERIC Educational Resources Information Center

    Jochum, Christopher J.

    2012-01-01

    Substitute teachers are an important part of students' K-12 educational experience and can have an impact on students' learning. However, without proper training or guidance, substitute teachers are often asked to merely monitor students as they complete worksheets or watch videos. Finding substitute teachers for foreign languages (such as…

  17. JAK2V617F Allele Burden Measurement in Peripheral Blood of Iranian Patients with Myeloproliferative Neoplasms and Effect of Hydroxyurea on JAK2V617F Allele Burden

    PubMed Central

    Ferdowsi, Shirin; Ghaffari, Seyed H.; Amirizadeh, Naser; Azarkeivan, Azita; Atarodi, Kamran; Faranoush, Mohammad; Toogeh, Gholamreza; Shirkoohi, Reza; Vaezi, Mohammad; Maghsoodlu, Mahtab; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Teimori Naghadeh, Hosein

    2016-01-01

    Background: Myeloproliferative neoplasms (MPNs) are clonal malignant diseases that represent a group of conditions including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The aim of this study was to evaluate possible correlations between JAK2V617F allele burden and clinicohematologic characteristics in Iranian patients with MPNs. We also aimed at determining the correlation between JAK2V617F allele burden and use of cyto reductive treatment (hydroxyurea). Materials and Methods: We performed ARMS-PCR for all MPNs samples and subsequently performed real-time quantitative polymerase chain reaction (qRT-PCR) for JAK2V617F allele burden measurement using DNA from peripheral blood leukocytes. Results: Two distinct groups of patients were examined at a single time point: group A (n=40; 20 PV, 20 ET) was examined at the time of diagnosis; group B (n=85; 40 PV, 30 ET and 15 PMF) while under treatment with hydroxyurea (HU). The median allele burden of the JAK2 V617F was 72% for PV and 49% for ET patients at the time of diagnosis (p=0.01). For patients with HU treatment, we determined the median JAK2V617F allele burden to be 43%, 40%, and 46.5 % in PV, ET and PMF patients; respectively. HU-treated PV patients had a significant lower %JAK2V617F than PV patients at the time of diagnosis (43% vs. 72%, p=0.005). In ET group, the relationship between the JAK2 V617F allele burden and leukocyte count was significant (p=0.02 and p=0.01 in untreated and treated patients, respectively). Conclusions: Our results showed that patients with PV have a higher JAK2V617F allele burden. Moreover, our study demonstrated that the JAK2V617F allele burden correlates with clinical features in ET group. We also showed hydroxyurea can affect the JAK2V617F allele burden in PV patients. PMID:27252806

  18. Effects of Sn Substitution on Thermoelectric Properties of Ge4SbTe5

    NASA Astrophysics Data System (ADS)

    Williams, Jared B.; Mather, Spencer; Morelli, Donald T.

    2016-02-01

    Phase-change materials are identified by their ability to rapidly alternate between amorphous and crystalline phases upon heating, exhibiting large contrast in the optical/electrical properties of the respective phases. Such materials are primarily used in memory storage applications, but recently they have also been identified as potential thermoelectric materials. Many of the phase-change materials studied today can be found on the pseudobinary (GeTe)1- x (Sb2Te3) x tie-line. Ge4SbTe5, a single-phase compound just off of the (GeTe)1- x (Sb2Te3) x tie-line, forms in a metastable rocksalt crystal structure at room temperature. It has been found that stoichiometric and undoped Ge4SbTe5 exhibits thermal conductivity of ~1.2 W/m-K at high temperature and a dramatic decrease in electrical resistivity at 623 K due to a structural phase transition, which leads to a large enhancement in both thermoelectric power factor and thermoelectric figure of merit at 823 K. Introducing point defects via isoelectronic substitutions can be an effective means of reducing thermal conductivity and enhancing thermoelectric performance. We present a study of the effects of Sn substitution for Ge on the electrical and thermal transport properties of Ge4SbTe5.

  19. Effect of steroidal saponins-loaded nano-bioglass/phosphatidylserine/collagen bone substitute on bone healing.

    PubMed

    Yang, Chunrong; Wu, Huazhong; Wang, Jianhua

    2016-11-10

    The objective of this study was to investigate the therapeutic potential of nano-bioglass/phosphatidylserine/collagen (nBG/PS/COL) scaffolds loaded with steroidal saponins as an inducer factor for skeletal defects. The drugs-encapsulated bone substitute was prepared by loading steroidal saponins-collagen microsphere suspension in nano-bioglass and phosphatidylserine (PS) composite. The scaffolds possess an interconnected porous structure with a porosity of about 82.3%. The pore size ranges from several micrometers up to about 400 μm. The drug release assays showed the long-term sustained release of steroidal saponins from the scaffolds with effective and safe bioactivity. Moreover, in vitro and in vivo studies showed that the involvement of steroidal saponins contributed to the secretion of nerve growth factor (NGF) in MC3T3-E1 cells, which may be the possible factor that greatly enhanced bone healing. The results suggest that the bone substitute is an effective implantable drug-delivery system for use in bone repair.

  20. Thermal conductivity of skutterudite CoSb3 from first principles: Substitution and nanoengineering effects

    PubMed Central

    Guo, Ruiqiang; Wang, Xinjiang; Huang, Baoling

    2015-01-01

    CoSb3-based skutterudites are promising intermediate-temperature thermoelectric materials and fundamental understanding of the thermal transport in CoSb3 is crucial for further improving its performance. We herein calculate the lattice thermal conductivity κL of CoSb3 with first-principles methods and conduct a comprehensive analysis on phonon mode contribution, relaxation time and mean free path (MFP) distributions. The contribution of optical phonons is found to be significant (28% at 300 K) and important optical modes usually involve two or more pnicogen atoms moving synchronously. The MFP (~135 nm at 300 K) corresponding to 50% κL accumulation in CoSb3 is much larger than that predicted from the kinetic theory (~4 nm), providing an opportunity to reduce κL by nanoengineering. The effects of elemental substitution and nanoengineering on κL are therefore investigated. A 10% substitution of Sb by As results in 57% reduction of κL while the in-plane (cross-plane) κL of a 50-nm CoSb3 thin film is only 56% (33%) of the bulk κL at 300 K. The impurity scattering and boundary scattering mainly suppress phonons in different frequency regimes. By combining these two effects, κL can be reduced by more than 70% at 300 K, potentially leading to much improved ZT near room temperature. PMID:25608469

  1. Aerobic degradation study of three fluoroanilines and microbial community analysis: the effects of increased fluorine substitution.

    PubMed

    Zhao, Zhi-Qing; Tian, Bao-Hu; Zhang, Xuan; Ghulam, Abbas; Zheng, Tu-Cai; Shen, Dong-Sheng

    2015-02-01

    The fate of fluorinated compounds in the environment, especially polyfluorinated aromatics, is a matter of great concern. In this work, 4-Fluoroaniline (4-FA), 2,4-Difluoroanilines (2,4-DFA), and 2,3,4-Trifluoroanilines (2,3,4-TFA), were chosen as the target pollutants to study their biodegradability under aerobic conditions. The required enriched time of the mixed bacterial culture for degrading 4-FA, 2,4-DFA, and 2,3,4-TFA was 26, 51, and 165 days, respectively, which suggested that the longer enrichment time was required with the increase of fluorine substitution. At the initial concentrations of 100-200 mg L(-1), the 4-FA, 2,4-DFA, and 2,3,4-TFA could be degraded completely by the mixed bacterial culture. The maximum specific degradation rates of 4-FA, 2,4-DFA, and 2,3,4-TFA were 22.48 ± 0.55, 15.27 ± 2.04, and 8.84 ± 0.93 mg FA (g VSS h)(-1), respectively. Also, the three FAs enriched cultures showed certain potential of degrading other two FAs. The results from enzyme assay suggested the expression of meta-cleavage pathways during three FAs degradation. The denaturing gradient gel electrophoresis analysis revealed that unique bacterial communities were formed after FAs enrichment and these were principally composed of β-Proteobacteria, Oscillatoriophycideae, δ-Proteobacteria, α-Proteobacteria, Thermales, Xanthomonadales, Deinococci, Flavobacteriia, and Actinobacteridae. The Shannon-Wiener indexes in three FAs enriched culture decreased with the increase of fluorine substitution, indicating the significant effect of fluorine substitution on the microbial diversity. These findings supply important information on the fate of three FAs under aerobic environment, and the bacterial communities in their degradation systems.

  2. Inhibitory effect of substituted dextrans on MCF7 human breast cancer cell growth in vitro.

    PubMed

    Morere, J F; Letourneur, D; Planchon, P; Avramoglou, T; Jozefonvicz, J; Israel, L; Crepin, M

    1992-12-01

    Substituted dextrans can reproduce some of the properties of heparin and can thus be used to alter cellular growth. We studied the effect of heparin (H108), dextran (D), carboxymethylbenzylamide dextran (CMDB) and carboxymethylbenzylamide sulfonate dextran (CMDBS) on the growth of human mammary cells of the MCF7 tumor line. The cells were cultured in minimum Eagle's medium containing 2% fetal calf serum without biopolymer, or with increasing concentrations of H108, D, CMDB or CMDBS. Growth curves were accurately based on cell counting using a Coulter counter. Cell distribution in the various phases of the cycle was analyzed by flow cytometry. Dose-dependent growth inhibitory effects (400-4000 micrograms/ml) were observed. The effect on MCF7 tumor cells was most apparent with CMDBS. The percentage of cells in the S phase decreased with preferential blocking in the G0/G1 phase. Pre-clinical studies can be anticipated as there is an absence of in vivo toxicity.

  3. Electronic Effects of 11β Substituted 17β-Estradiol Derivatives and Instrumental Effects on the Relative Gas Phase Acidity

    NASA Astrophysics Data System (ADS)

    Bourgoin-Voillard, Sandrine; Fournier, Françoise; Afonso, Carlos; Zins, Emilie-Laure; Jacquot, Yves; Pèpe, Claude; Leclercq, Guy; Tabet, Jean-Claude

    2012-12-01

    Numerous studies have highlighted the role of the proton donor characteristics of the phenol group of 17β-estradiol (E2) in its association with the estrogen receptor alpha (ERα). Since the substitutions at position C(11) have been reported to modulate this association, we hypothesized that such substitutions may modify the phenol acidity. Hence, phenol gas-phase acidity of nine C(11)-substituted E2-derivatives were evaluated using the extended Cooks' kinetic method, which is a method widely used to determine thermochemical properties by mass spectrometry. To enhance accuracy in data collection we recorded data from several instruments, including quadrupole ion trap, triple quadrupole, and hybrid QqTOF. Indeed, we report for the first time the use of the QqTOF instrument to provide a novel means to improve data accuracy by giving access to an intermediate effective temperature range. All experimental gas-phase acidity values were supported by theoretical calculations. Our results confirmed the ability of distant substituents at C(11) to modulate the phenol acidity through electrostatic interactions, electron withdrawing inductive effects, and mesomeric effects. However, no relationship was found between the phenol gas-phase acidity of investigated steroids and their binding affinity for ERα assessed in solution. Thus, our results highlight that the intrinsic properties of the hormone do not influence sufficiently the stabilization of the hormone/ERα complex. It is more likely that such stabilization would be more related to factors depending on the environment within the binding pocket such as hydrophobic, steric as well as direct intermolecular electrostatic effects between ERα residues and the substituted steroidal estrogens.

  4. Effect of metallothionein 2A gene polymorphism on allele-specific gene expression and metal content in prostate cancer

    SciTech Connect

    Krześlak, Anna; Forma, Ewa; Jóźwiak, Paweł; Szymczyk, Agnieszka; Bryś, Magdalena

    2013-05-01

    Metallothioneins (MTs) are highly conserved, small molecular weight, cysteine rich proteins. The major physiological functions of metallothioneins include homeostasis of essential metals Zn and Cu and protection against cytotoxicity of heavy metals. The aim of this study was to determine whether there is an association between the − 5 A/G single nucleotide polymorphism (SNP; rs28366003) in core promoter region and expression of metallothionein 2A (MT2A) gene and metal concentration in prostate cancer tissues. MT2A polymorphism was determined by the polymerase chain reaction–restriction fragment length polymorphism technique (PCR–RFLP) using 412 prostate cancer tissue samples. MT2A gene expression analysis was performed by real-time RT-PCR method. A significant association between rs28366003 genotype and MT2A expression level was found. The average mRNA level was found to be lower among minor allele carriers (the risk allele) than average expression among homozygotes for the major allele. Metal levels were analyzed by flamed atomic absorption spectrometer system. Highly statistically significant associations were detected between the SNP and Cd, Zn, Cu and Pb levels. The results of Spearman's rank correlation showed that the expressions of MT2A and Cu, Pb and Ni concentrations were negatively correlated. On the basis of the results obtained in this study, we suggest that SNP polymorphism may affect the MT2A gene expression in prostate and this is associated with some metal accumulation. - Highlights: • MT2A gene expression and metal content in prostate cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn, Cu and Pb levels • Negative correlation between MT2A gene expression and Cu, Pb and Ni levels.

  5. Dose effect of allele {epsilon}4 of apolipoprotein E on risk and age at onset of Pick disease

    SciTech Connect

    Farrer, L.A.; Abraham, C.; Volicer, L.

    1994-09-01

    Pick disease (PD) is a rare progressive dementing illness characterized by severe atrophy of the frontal and temporal lobes. Brains of PD patients lack neurofibrillary tangles which are characteristic findings of Alzheimer disease (AD), but display neuronal swelling and argyrophilic inclusions (i.e., Pick bodies) which contain phosphorylated neurofilaments, tau and complex lipids. Clinically, PD is often difficult to distinguish from AD. The fact that PD is often familial and the evidence suggesting that the {epsilon}4 allele of apoE is a risk factor for AD and multi-infarct dementia prompted us to study apoE isoforms in PD. ApoE genotypes were evaluated in an autopsy series of cases (19 AD, 15 PD, and 7 {open_quotes}controls{close_quotes} with other or no pathology). All subjects were unrelated except for 2 brothers who both had PD. Age at onset in the PD patients ranged from 41 to 59 years. The frequency of {epsilon}4 is significantly higher among AD subjects (47.4%) than in Pick cases (23.3%; P=0.4) or controls (7.1%; P=.008), but the 16% difference between PD and control subjects was not significant, perhaps due to small sample sizes. Linear regression analysis showed that the number of {epsilon}4 alleles was inversely related to age at onset of PD (P=.04) and accounted for 27% of the variation in age at onset. These results suggest that {epsilon}4 may be a susceptibility factor for dementia and not specifically AD. Preliminary experiments using an antibody against apoE suggest that Pick bodies may be immunoreactive with this antibody and that apoE binds to abnormal filaments. The association of the {epsilon}4 allele with dementias other than AD and the apoE staining results support a model postulating an interaction between the {epsilon}4 isoform and tau.

  6. Enhancing excited state intramolecular proton transfer in 2-(2'-hydroxyphenyl)benzimidazole and its nitrogen-substituted analogues by β-cyclodextrin: the effect of nitrogen substitution.

    PubMed

    Chipem, Francis A S; Behera, Santosh Kumar; Krishnamoorthy, G

    2013-05-23

    Excited state intramolecular proton transfer (ESIPT) in nitrogen-substituted analogues of 2-(2'-hydroxyphenyl)benzimidazole (HPBI), 2-(2'-hydroxyphenyl)-3H-imidazo[4,5-b]pyridine (HPIP-b), and 2-(2'-hydroxyphenyl)-3H-imidazo[4,5-c]pyridine (HPIP-c) have been investigated in a β-cyclodextrin (β-CD) nanocavity and compared with that of HPBI. The stoichiometry and the binding constants of the complexes were determined by tautomer emissions. Both pKa and NMR experiments were employed to determine the orientation of the molecules inside of the β-CD cavity. Huge enhancement in the tautomer emission of HPIP-b and HPIP-c compared to that of HPBI in β-CD suggests that not only is the ESIPT favored inside of the cavity, but also, the environment reduces the nonradiative decay through the formation of an intramolecular charge-transfer (ICT) state. Unlike HPBI, the tautomer emission to normal emission ratio of HPIP-b increases from 0.9 to 2.6, and that of HPIP-c increases from 4.9 to 7.4 in 15 mM β-CD. The effect of dimethylsulfoxide (DMSO) on complexation was also investigated for all three guest molecules. In DMSO, HPBI is present in neutral form, but the nitrogen-substituted analogues are present in both neutral and monoanionic forms. However, in DMSO upon encapsulation by β-CD, all three molecules are present in both neutral and monoanionic forms in the nanocavity. The monoanion is stabilized more inside of the β-CD cavity. The studies revealed that the ESIPT of nitrogen-substituted analogues is more susceptible to the environment than HPBI, and therefore, they are more promising probes.

  7. Efficacious rat model displays non-toxic effect with Korean beechwood creosote: a possible antibiotic substitute

    PubMed Central

    Quynh, Anh Nguyen Thai; Sharma, Neelesh; Cho, Kwang Keun; Yeo, Tae Jong; Kim, Ki Beom; Jeong, Chul Yon; Min, Tae Sun; Young, Kim Jae; Kim, Jin Nam; Jeong, Dong-Kee

    2014-01-01

    Wood creosote, an herbal anti-diarrheal and a mixture of major volatile compounds, was tested for its non-toxicological effects, using a rat model, with the objective to use the creosote as an antibiotic substitute. A total of 30 Sprague-Dawley rats were studied to form five groups with 6 rats each. Korea beechwood creosote was supplemented into three test groups with 0.03 g/kg, 0.07 g/kg and 0.1 g/kg body weight/day without antibiotic support, along with a positive control of Apramycin sulphate (at 0.5% of the daily feed) and a negative control. Korean beechwood creosote supplementation showed no negative effect on the body weight gain in comparison to the negative and the positive control groups and the feed conversion ratio was also comparable with that of the control groups. The clinical pathology parameters studied were also under the umbrella of normal range, including liver specific enzymes, blood glucose, total protein, blood urea nitrogen (BUN), which indicated no toxic effect of creosote at the given doses. The non-hepatotoxic effect was also confirmed using hepatic damage specific molecular markers like Tim-p1, Tim-p2 and Tgf-β1. The results suggested that Korean beechwood may be used as antibiotic substitute in weanling pigs feed without any toxic effect on the body. Although the antimicrobial properties of creosote were not absolutely similar to those of apramycin sulphate, they were comparable. PMID:26019530

  8. Effects of substitution groups of glutamide-derived molecular gels on molecular shape recognition.

    PubMed

    Noguchi, Hiroki; Charoenraks, Tiraporn; Takafuji, Makoto; Ihara, Hirotaka

    2015-05-01

    We have reported that self-assembling glutamide lipid-grafted porous silica particles show high selectivity towards polycyclic aromatic hydrocarbons (PAHs) and bio-molecules. This enhancement of molecular recognition is brought about by the formation of a highly ordered structure in the glutamide lipid through intermolecular hydrogen bonding. To utilise, for selective separations, the highly oriented structure of glutamide lipids on the silica surface, in this study, we synthesised four glutamide lipids with different substitution groups and studied the separation behaviours of the glutamide lipid-grafted porous silica particles as reversed phase high-performance liquid chromatography (RP-HPLC) stationary phases. According to the HPLC studies, the functional group substitutions and the spacer group connecting the glutamide moiety and silica surface had a noticeable effect on the retention behaviours. Particularly, glutamide lipids with a long spacer group (C10) showed a higher selectivity towards positional (o-/m-/p-terphenyl) and geometrical (cis-/trans-stilbene) isomers. Differential scanning calorimetric and Fourier transform infrared spectroscopic studies suggested that the long spacer group induced the assembled structure of the glutamide lipid on the silica surface. Interestingly, the glutamide lipids with dodecyl groups and benzyl groups showed reverse elution orders towards the length to breadth ratio of PAHs.

  9. Effect of fluoride-substituted apatite on in vivo bone formation.

    PubMed

    Inoue, Miho; Rodriguez, Andrea P; Nagai, Noriyuki; Nagatsuka, Hitoshi; LeGeros, Racquel Z; Tsujigiwa, Hidetsugu; Inoue, Masahisa; Kishimoto, Etsuo; Takagi, Shin

    2011-05-01

    Biological apatites are characterized by the presence of minor constituents such as magnesium (Mg), chloride (Cl), or fluoride (F) ions. These ions affect cell proliferation and osteoblastic differentiation during bone tissue formation. F-substituted apatites are being explored as potential bonegraft materials. The aim of the present study is to investigate the mechanism of bone formation induced by fluoride-substituted apatite (FAp) by analyzing the effect of FAp on the process of in vivo bone formation. FAps containing different F concentrations (l-FAp: 0.48 wt%, m-FAp: 0.91 wt%, h-FAp: 2.23 wt%) and calcium-deficient apatite (CDA), as positive control, were implanted in rat tibia and bone formation was evaluated by histological examination, immuhistochemistry, in situ hybridization and tartrate-resistant acid phosphatase examinations. The results showed that l-FAp, m-FAp, h-FAp, and CDA biomaterials allowed migration of macrophages, attachment, proliferation, and phenotypic expression of bone cells leading to new bone formation in direct apposition to the particles. However, the l-FAp preparation allowed faster bone conduction compared to the other experimental materials. These results suggest that FAp with low F concentration may be an efficient bonegraft material for dental and medical application.

  10. Nucleotide substitution type dependence of generation time effect of molecular evolution.

    PubMed

    Kisakibaru, Y; Matsuda, H

    1995-06-01

    Using DNA sequence data of 18 genes from 14 mammals, we analyzed how the average molecular evolution rate per year per site (Vy) depends on the generation time (g). (I) Assuming the relation Vy varies; is directly proportional to g(-alpha), the index of generation time effect, (alpha) was estimated to be about 0.14 for amino acid replacement substitutions (A), and about 0.32 for synonymous substitutions (S). (II) Assuming the relation Vy = V(m)g g-1 + V(e)y, where V(m)g and V(e)y are constant independent of g, the fraction, r(e) = V(e)y/Vy, of the mutation rate independent part (V(e)y) in the total evolution rate (Vy) was estimated under the assumptions of the star phylogeny and the constancy of the mutation rate per generation. r(e) was smallest for mouse with the shortest generation time among our analyzed species, and it was estimated to be about 0.57 for A and 0.31 for S. Both results do not support the view that Vy is equal to the neutral mutation rate per site both for A and for S. They are in line with the thesis that, at least for A and probably even for S, the molecular evolution rate is influenced by some causes other than the mutation rate, such as changing environment.

  11. Effect of In3+ substitution on structural and magnetic properties of Ni ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Meng, Fanbin; Shang, Xueni; Zhang, Wei; Zhang, Yujie

    2017-01-01

    NiInxFe2-xO4 (x=0.0, 0.1, 0.2, 0.3, 0.4) ferrite nanoparticles have been synthesized by sol-gel autocombustion technique. The effect of In3+ substitution on the structural and magnetic properties of nickel ferrite has been analyzed by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Field emission scanning electron microscopy (FESEM) and Vibrating sample magnetometer (VSM). The XRD results confirmed the formation of single cubic spinel phase for 0 ≤ x ≤ 0.3 and the appearance of secondary phase of In2O3 for x=0.4. The lattice parameter increases (from 8.3152 to 8.4336 Å) with indium content. The FTIR results illustrated that the absorption intensity of peak at about 594 cm-1 increases with increasing the In3+ ions. The saturation magnetization increases and then decreases while the coercivity decreases along with In3+substitution. The maximal saturation magnetization emerged at the composition of NiIn0.2Fe1.8O4 (42.111 emu/g).

  12. N9-substituted derivatives of kinetin: effective anti-senescence agents.

    PubMed

    Mik, Václav; Szüčová, Lucie; Smehilová, Mária; Zatloukal, Marek; Doležal, Karel; Nisler, Jaroslav; Grúz, Jiří; Galuszka, Petr; Strnad, Miroslav; Spíchal, Lukáš

    2011-06-01

    The first isolated cytokinin, 6-furfurylaminopurine (kinetin or Kin), was identified almost 55years ago. Its biological effects on plant cells and tissues include influences on such processes as gene expression, cell cycle, chloroplast development, chlorophyll biosynthesis, stimulation of vascular development, delay of senescence, and mobilization of nutrients. In the present study we prepared a series of eight N9-substituted Kin derivatives, and characterized them with available physicochemical methods such as CI+ mass spectrometry and (1)H NMR spectroscopy. All compounds were tested in three classical cytokinin bioassays: a tobacco callus assay, an Amaranthus assay, and a senescence assay with excised wheat leaves. The ability of the compounds to interact with Arabidopsis cytokinin receptors CRE1/AHK4 and AHK3 was tested in a bacterial receptor assay. Prepared derivatives with certain substitutions of the N9-atom of the purine moiety enhanced the cytokinin activity of the parent compound in the bioassays to a remarkable degree but negatively affected its perception by CRE1/AHK4 and AHK3. The ability of compounds to delay the senescence of excised wheat leaves in both dark and light conditions, was highly correlated with their ability to influence membrane lipid peroxidation, which is a typical symptom of senescence. Our results were corroborated by gene expression profiling of those genes involved in cytokinin metabolism and perception, plant senescence, and the stress response, and suggest that prepared kinetin derivatives might be used as potent anti-senescence agents.

  13. Effects of Ce-Co substitution on the magnetic properties of M-type barium hexaferrites

    NASA Astrophysics Data System (ADS)

    Zi, Z. F.; Liu, Q. C.; Dai, J. M.; Sun, Y. P.

    2012-05-01

    M-type barium hexaferrites Ba1-xCexFe12-xCoxO19 (0.0≤x≤0.3) have been synthesized by a simple chemical coprecipitation method. X-ray diffraction (XRD) studies indicate that the samples are of single phase, with space group P63/mmc. The results of field-emission scanning electronic microscopy (FE-SEM) show that the grains are regular hexagonal platelets with sizes from 0.5 to 1.5 μm. It is observed that the value of the coercivity field (Hc) increases at low substitution (x≤0.1), reaches a maximum at x=0.1, and then decreases at x≥0.1, while the value of saturation magnetization (Ms) decreases monotonically with increasing x. The variations of magnetic properties can be tentatively attributed to the effects of Ce-Co substitution. The results above indicate that our samples might be promising candidates for permanent magnets and perpendicular recording media materials in the future.

  14. Gadolinium substitution effect on the thermomagnetic properties of Ni ferrite ferrofluids

    NASA Astrophysics Data System (ADS)

    Jacobo, Silvia E.; Arana, Mercedes; Bercoff, Paula G.

    2016-10-01

    This work is focused on the structural and magnetic characterization of Gd-doped Ni ferrite nanoparticles and the preparation of a ferrofluid for applications in heat-transfer devices. For this purpose, spinel ferrites NiFe2O4, and NiFe1.88Gd0.12O4 were prepared by the self-combustion method. The substituted sample was obtained with a small amount of Gd inclusion and the excess appeared as GdFeO3. The smallest nanoparticles of both samples were properly coated and dispersed in kerosene. Thermal conductivities of the produced ferrofluids were measured at 25 °C under an applied magnetic field. There is a significant enhancement in the thermal conductivity of the ferrofluid prepared with NiGd ferrite with respect to the one with Ni ferrite, in presence of a magnetic field. This effect is directly related to the well-known magnetocaloric effect of Gd.

  15. Dynamical barrier and isotope effects in the simplest substitution reaction via Walden inversion mechanism

    PubMed Central

    Zhao, Zhiqiang; Zhang, Zhaojun; Liu, Shu; Zhang, Dong H

    2017-01-01

    Reactions occurring at a carbon atom through the Walden inversion mechanism are one of the most important and useful classes of reactions in chemistry. Here we report an accurate theoretical study of the simplest reaction of that type: the H+CH4 substitution reaction and its isotope analogues. It is found that the reaction threshold versus collision energy is considerably higher than the barrier height. The reaction exhibits a strong normal secondary isotope effect on the cross-sections measured above the reaction threshold, and a small but reverse secondary kinetic isotope effect at room temperature. Detailed analysis reveals that the reaction proceeds along a path with a higher barrier height instead of the minimum-energy path because the umbrella angle of the non-reacting methyl group cannot change synchronously with the other reaction coordinates during the reaction due to insufficient energy transfer from the translational motion to the umbrella mode. PMID:28224993

  16. Dynamical barrier and isotope effects in the simplest substitution reaction via Walden inversion mechanism.

    PubMed

    Zhao, Zhiqiang; Zhang, Zhaojun; Liu, Shu; Zhang, Dong H

    2017-02-22

    Reactions occurring at a carbon atom through the Walden inversion mechanism are one of the most important and useful classes of reactions in chemistry. Here we report an accurate theoretical study of the simplest reaction of that type: the H+CH4 substitution reaction and its isotope analogues. It is found that the reaction threshold versus collision energy is considerably higher than the barrier height. The reaction exhibits a strong normal secondary isotope effect on the cross-sections measured above the reaction threshold, and a small but reverse secondary kinetic isotope effect at room temperature. Detailed analysis reveals that the reaction proceeds along a path with a higher barrier height instead of the minimum-energy path because the umbrella angle of the non-reacting methyl group cannot change synchronously with the other reaction coordinates during the reaction due to insufficient energy transfer from the translational motion to the umbrella mode.

  17. Solvent and structural effects on the UV absorption spectra of N-(substituted phenyl)-2-cyanoacetamides.

    PubMed

    Matijević, Borko M; Vaštag, Đenđi Đ; Perišić-Janjić, Nada U; Apostolov, Suzana Lj; Milčić, Miloš K; Živanović, Lidija; Marinković, Aleksandar D

    2014-01-03

    UV absorption spectra of N-(substituted phenyl)-2-cyanoacetamides have been recorded in the range 200-400 nm in the set of selected solvents. The solute-solvent interactions were analyzed on the basis of linear solvation energy relationships (LSER) concept proposed by Kamlet and Taft. The effects of substituents on the absorption spectra were interpreted by correlation of absorption frequencies with Hammett substituent constant, σ. It was found that substituents significantly change the extent of conjugation. Furthermore, the experimental findings were interpreted with the aid of ab initio B3LYP/6-311G(d,p) method. Electronic energies was calculated by the use of 6-311++G(3df,3pd) methods with standard polarized continuum model (PCM) for inclusion of the solvent effect.

  18. Effects of alloy chemistry on the electrochemical and hydriding properties of nickel-substituted lanthanum nickel

    NASA Astrophysics Data System (ADS)

    Witham, Charles Kincaid

    The primary goal of this work was to verify the hypothesis that alloying LaNi5 with ternary elements that have a large heat of formation with La (and secondarily, with Ni) would slow the kinetics of metal (La) atom diffusion. This would have the effect of stabilizing the Haucke phase crystal structure of LaNi5 during electrochemical and gas-phase hydrogen absorption/desorption cycling, and extending the material's useful lifetime. To test this hypothesis, I prepared a variety of single-phase alloys of composition LaNi5-xMx, 0 ≤ x ≤ 0.5, M∈ {Al, Si, Ga, Ge, In, Sn}. Each alloy was annealed to insure equilibrium starting conditions. The lifetimes of these alloys were tested by charge-discharge cycling as the anode of an alkaline Ni-MH rechargeable cell. By characterizing the lifetimes of the alloys as an exponential capacity decay, I was able to determine a trend between the capacity decay and the heat of formation of an average 'B' element with La. The alloys were further characterized by obtaining gas-phase isotherms and, in the case of the Gex alloys, the thermodynamics of metal hydride formation and decomposition. X-ray diffraction was used to measure the effect of substitution on the alloy and its hydride phase. By examining the data obtained at Caltech as well as data published in the literature, several trends were noted. There is a fairly linear relationship between the solute's expansion of the LaNi5 unit cell and its radius. The total volume expansion an alloy experienced upon absorption of hydrogen was found to decrease with substituted composition. The discrete lattice expansion of Gex alloys was found to decrease substantially for 0 < x < 0.2, but subsequent substitution had little effect on the volume expansion. The electrode electrochemical kinetice of charge transfer were investigated for each MH alloy. Measurements of the charge transfer exchange current by micropolarization and AC impedance were similar, while those measured by Tafel

  19. Paradoxical solvent effects on the absorption and emission spectra of amino-substituted perylene monoimides.

    PubMed

    Zoon, Peter D; Brouwer, Albert M

    2005-08-12

    In N-(2,5-di-tert-butylphenyl)-9-pyrrolidinoperylene-3,4-dicarboximide (5PI) the absorption and emission spectra display large solvatochromic shifts, but, remarkably, the Stokes shift is practically independent of solvent polarity. This unique behavior is caused by the extraordinarily large ground-state dipole moment of 5PI, which further increases upon increasing the solvent polarity, whereas the excited-state dipole moment is less solvent dependent. In the corresponding piperidine compound, 6PI, this effect is much less important owing to the weaker coupling between the amino group and the aromatic imide moiety, and in the corresponding naphthalimide, 5NI, it is absent. The latter shows the conventional solvatochromic behavior of a push-pull substituted conjugated system, that is, minor shifts in absorption and a larger change in the emission energy with solvent polarity.

  20. Synthesis; characterization and antimicrobial effects of composites based on multi-substituted hydroxyapatite and silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Mocanu, Aurora; Furtos, Gabriel; Rapuntean, Sorin; Horovitz, Ossi; Flore, Chirila; Garbo, Corina; Danisteanu, Ancuta; Rapuntean, Gheorghe; Prejmerean, Cristina; Tomoaia-Cotisel, Maria

    2014-04-01

    Nano hydroxyapatite doped with zinc (0.2 wt%), silver (0.25 wt%) and gold (0.025 wt%), (HAP), has been obtained by an innovative wet chemical approach, coupled with a reduction process for silver and gold. The synthesized multi-substituted nano HAP was freeze-dried and calcined at 650 °C. Nano HAP has been characterized by XRD, FTIR spectroscopy and imaging techniques: TEM, SEM and AFM. Then, nano HAP was mixed with previously synthesized silver nanoparticles (AgNPs), in the amount of 9 wt%, to give a novel material (HAP-Ag). The AgNPs were prepared by the reduction of silver nitrate with glucose in alkaline medium. TEM and UV-Vis confirmed the formation of AgNPs with an average size of 12 nm. Further, organic matrix composites were obtained from a filler made of HAP and/or HAP-Ag and a mixture of monomers (such as bis-GMA and TEG-DMA), which were polymerized at various compositions in AgNPs content up to 5.4 wt%. Antibacterial activities of these composites were investigated against several different pathogenic species: Escherichia coli, Staphylococcus aureus, Staphylococcus spp., Bacillus cereus, and Candida albicans, using the Kirby-Bauer disk-diffusion method. Antibacterial activities are enhanced with increasing of silver content within composites. These effects clearly reveal that AgNPs can be effectively utilized in combination with multi-substituted HAP and polymeric matrix, both used as carriers, in order to improve their efficiency against various pathogenic species. These composites can be considered a promising antimicrobial material for coating of orthopedic and dental implants or used as bone cements in surgical applications.

  1. Chemical and electronic characterization of cobalt in a lanthanum perovskite. Effects of strontium substitution

    SciTech Connect

    Hueso, Jose L.; Holgado, Juan P.; Pereniguez, Rosa; Mun, Simon; Salmeron, Miquel; Caballero, Alfonso

    2010-01-15

    Two different cobaltites, LaCoO{sub 3} and La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}}, have been prepared and characterized by means of high energy Co K-edge and low energy O K-edge X-ray absorption spectroscopy (XAS). Even though half of the La(III) is substituted by Sr(II), little or no changes can be detected in the formal oxidation state of cobalt atoms. The presence of strontium cations induces two main effects in the chemical and electronic state of the perovskite. The charge balance with Sr(II) species is reached by the formation of oxygen vacancies throughout the network, which explains the well-known increase in the reactivity of this substituted perovskite. O K-edge XAS experiments show that the Sr(II) species induce the transitions of d electrons of cobalt cations from low to high spin configuration. We propose that this change in spin multiplicity is induced by two cooperative effects: the oxygen vacancies, creating five coordinated cobalt atoms, and the bigger size of Sr(II) cations, aligning the Co-O-Co atoms, and favoring the overlapping of pi-symmetry cobalt and oxygen orbitals, reducing the splitting energy of e{sub g} and t{sub 2g} levels. - Graphical abstract: Change in spin multiplicity induced by the bigger size of Sr(II) cations, aligning the Co-O-Co atoms, and favoring the overlapping of pi-symmetry cobalt and oxygen orbitals.

  2. Allele Workbench: transcriptome pipeline and interactive graphics for allele-specific expression.

    PubMed

    Soderlund, Carol A; Nelson, William M; Goff, Stephen A

    2014-01-01

    Sequencing the transcriptome can answer various questions such as determining the transcripts expressed in a given species for a specific tissue or condition, evaluating differential expression, discovering variants, and evaluating allele-specific expression. Differential expression evaluates the expression differences between different strains, tissues, and conditions. Allele-specific expression evaluates expression differences between parental alleles. Both differential expression and allele-specific expression have been studied for heterosis (hybrid vigor), where the hybrid has improved performance over the parents for one or more traits. The Allele Workbench software was developed for a heterosis study that evaluated allele-specific expression for a mouse F1 hybrid using libraries from multiple tissues with biological replicates. This software has been made into a distributable package, which includes a pipeline, a Java interface to build the database, and a Java interface for query and display of the results. The required input is a reference genome, annotation file, and one or more RNA-Seq libraries with optional replicates. It evaluates allelic imbalance at the SNP and transcript level and flags transcripts with significant opposite directional allele-specific expression. The Java interface allows the user to view data from libraries, replicates, genes, transcripts, exons, and variants, including queries on allele imbalance for selected libraries. To determine the impact of allele-specific SNPs on protein folding, variants are annotated with their effect (e.g., missense), and the parental protein sequences may be exported for protein folding analysis. The Allele Workbench processing results in transcript files and read counts that can be used as input to the previously published Transcriptome Computational Workbench, which has a new algorithm for determining a trimmed set of gene ontology terms. The software with demo files is available from https://code.google.com/p/allele

  3. Characterization of the treefrog null allele

    SciTech Connect

    Guttman, S.I. . Dept. of Zoology)

    1990-12-01

    As part of the authors intensive year-long baseline ecological study, they characterized the degree of genetic polymorphism and heterozygosity in selected Feed Materials Production Center (FMPC) populations using electrophoretic techniques. These data are being used as an indicator of stress by comparing populations on and off the FMPC site. The current study was initiated to determine whether this GPI null allele is lethal, when homozygous, in spring peepers. Also, a sampling protocol was implemented to determine whether a linear effect occurs relative to the frequency of the null allele offsite and to determine the origination site of the null allele. 18 refs., 2 figs., 4 tabs.

  4. Effects of substituting yellow corn for sorghum in geese diets on magret and foie gras quality.

    PubMed

    Arroyo, J; Auvergne, A; Dubois, J P; Lavigne, F; Bijja, M; Bannelier, C; Manse, H; Fortun-Lamothe, L

    2013-09-01

    The aim of this trial was to study the effects of substitution of yellow corn with sorghum during the growing-finishing (G period), overfeeding (O period), or both periods on magret and foie gras quality in geese. In total, 260 ganders were divided into 4 groups (65 birds in each) differing in the cereal (yellow corn or sorghum) included in the diet given during the G and the O periods, using a 2 × 2 factorial arrangement of treatments. The groups differed in the nature of the cereal in the diet offered to birds between 44 and 104 d of age (G period: a diet containing 500 g of sorghum/kg (SS and SC groups) or a diet containing 500 g of yellow corn/kg (CS and CC groups). The groups differed also in the diet offered to birds between 105 and 120 d of age (O period): 967 g of yellow corn/kg (SC and CC groups) or 965 g of sorghum/kg (SS and CS groups). At the end of the O period, the birds were slaughtered after 10 h of fasting to measure foie gras and breast muscle weight, color, and chemical composition. The mortality in the SC group was higher (P < 0.05) than in the other 3 groups (14.29 vs. 3.58%, average of the 3 groups). After overfeeding, birds fed with sorghum had foie gras that were heavier 984 vs. 885 g, in CS+SS vs. CC+SC groups, respectively; P < 0.001) and less yellow (18.03 vs. 23.97 for b*, in CS+SS vs. CC+SC groups, respectively, P < 0.001) than birds fed with corn. The substitution of yellow corn with sorghum during the G and O periods (SS group) increased the weight of the foie gras, but altered its color to a paler yellow. In contrast, a substitution during the G period only (SC group) resulted in increased mortality during the O period.

  5. The effects of certain glycols, substituted glycols and related organic solvents on the thermal stability of soluble collagen

    PubMed Central

    Hart, G. J.; Russell, A. E.; Cooper, D. R.

    1971-01-01

    The effects of a number of related diols, substituted diols and glycerol on the thermal stability of acid-soluble calf skin collagen were investigated. Thermal transition temperatures were determined by optical rotation measurement. Short-chain diols with terminal hydroxyl groups, i.e. ethylene glycol and propane-1,3-diol, stabilized the protein at all accessible concentrations. Stabilization was also observed with glycerol and diethylene glycol. Higher homologues in the diol series produced various effects, as did hydroxyl-group positional isomerism. Monoalkyl substitution of diols progressively lowered the denaturation temperature of collagen. Results are discussed in relation to possible mechanisms of perturbant action. PMID:5169191

  6. Inhibitory effects of thought substitution in the think/no-think task: evidence from independent cues.

    PubMed

    del Prete, Francesco; Hanczakowski, Maciej; Bajo, Maria Teresa; Mazzoni, Giuliana

    2015-01-01

    When people try not to think about a certain item, they can accomplish this goal by using a thought substitution strategy and think about something else. Research conducted with the think/no-think (TNT) paradigm indicates that such strategy leads subsequently to forgetting the information participants tried not to think about. The present study pursued two goals. First, it investigated the mechanism of forgetting due to thought substitution, contrasting the hypothesis by which forgetting is due to blocking caused by substitutes with the hypothesis that forgetting is due to inhibition (using an independent cue methodology). Second, a boundary condition for forgetting due to thought substitution was examined by creating conditions under which the generation of appropriate substitutes would be impaired. In two experiments, participants completed a TNT task under thought substitution instructions in which either words or pseudo-words were used as original cues and memory was assessed with original and independent cues. The results revealed forgetting in both original and independent cue tests, supporting the inhibitory account of thought substitution, but only when cues were words, and not when they were non-words, pointing to the ineffectiveness of a thought substitution strategy when original cues lack semantic content.

  7. Orthographic Effects in the Word Substitutions of Aphasic Patients: An Epidemic of Right Neglect Dyslexia?

    ERIC Educational Resources Information Center

    Berndt, Rita Sloan; Haendiges, Anne N.; Mitchum, Charlotte C.

    2005-01-01

    Aphasic patients with reading impairments frequently substitute incorrect real words for target words when reading aloud. Many of these word substitutions have substantial orthographic overlap with their targets and are classified as ''visual errors'' (i.e., sharing 50% of targets' letters in the same relative position). Fifteen chronic aphasic…

  8. Dynamics of water in synthetic saponite clays: Effect of trivalent ion substitution

    NASA Astrophysics Data System (ADS)

    Mitra, S.; Prabhudesai, S. A.; Chakrabarty, D.; Sharma, V. K.; Vicente, M. A.; Embs, J. P.; Mukhopadhyay, R.

    2013-06-01

    Saponite clay belongs to the phyllosilicate family and is comprised of layers of Si(IV) tetrahedra and Al(III) or Mg(II) octahedra with definite interlayer spacing. In these systems, the trivalent ion substitutions in the tetrahedral layers lead to negative charge on the layers. Here we report the dynamics of water contained in [Si6.97Al1.03][Ni6.00]O20(OH)4[Na1.03]·28H2O (SAP-1) and [Si7.13Fe0.86][Ni6.00]O20(OH)4[Na0.86]·14H2O (SAP-2) saponite clays in the temperature range 200-310 K as studied by quasielastic neutron scattering technique. Particularly the effect of the ion substitution towards the dynamics of water is addressed here. Data analysis is carried out using the relaxing cage model. The existence of distribution in relaxation times indicated that the water molecules in saponite clay have a different local environment which leads to complex diffusion behavior. It is found that water exists in a supercooled state in the temperature range up to 235 K. However, some of the water molecules are found to be immobile in the temperature range 240-285 K. The fraction of immobile water decreases with increase in temperature. At higher temperatures, some of the water molecules in the hydration shells or those near the surface start participating in the diffusion process and at 293 K, almost all water molecules contribute to the dynamics. Diffusivity of water in both SAP-1 and SAP-2 are found to be lower in comparison to the bulk, and within the two samples of saponite clay diffusivity in SAP-1 is found to be lower compared to SAP-2; this has been explained on the basis of the charge on the tetrahedral layers and the charge balancing cations in the interlayer spacing.

  9. Effect of chain length on thermal conversion of alkoxy-substituted copper phthalocyanine precursors.

    PubMed

    Fukuda, Takamitsu; Kikukawa, Yuu; Tsuruya, Ryota; Fuyuhiro, Akira; Ishikawa, Naoto; Kobayashi, Nagao

    2011-11-21

    A series of dialkoxy-substituted copper phthalocyanine (CuPc) precursors (4a-4d) have been prepared by treating phthalonitrile with the corresponding lithium alkoxide under mild conditions. The precursors exhibited high solubilities in common organic solvents, including acetone, toluene, tetrahydrofuran (THF), CH(2)Cl(2), and CHCl(3). Elongation of the alkoxy chains improved the solubilities of the precursors effectively, and accordingly, the butoxy-substituted derivative (4d) showed the highest solubility among 4a-4d. X-ray crystallography clarified that the conjugated skeletons of 4a-4d are all isostructural, and have two alkoxy groups in a syn-conformation fashion, leading to highly bent structures. Thermal conversions of the precursors examined by thermogravimetry (TG) and differential thermal analysis (DTA) demonstrate that 4a was converted into CuPc via two distinct exothermic processes in the 200-250 °C temperature range, while 4d exhibits only one exothermic signal in the DTA. In the field emission scanning electron microscopy (FESEM) images of 4a, the presence of two types of distinct crystal morphology (prismatic and plate-like crystals) can be recognized, implying that the two observed exothermic processes in the DTA can be attributed to the different crystal morphologies of the samples rather than the step-by-step elimination of the alkoxy groups. The thermal formation of CuPc from the precursors has been unambiguously confirmed by X-ray powder diffraction, UV-vis spectroscopy, and elemental analysis. The precursors were converted into CuPc at lower temperature with increasing chain length, presumably because of the increased void volume in the crystals. Thermal conversion performed in the solution phase results in a bright blue-colored solution with prominent absorption bands in the 650-700 nm region, strongly supporting the formation of CuPc.

  10. Effects of Alloying on Nanoscale Grain Growth in Substitutional Binary Alloy System: Thermodynamics and Kinetics

    NASA Astrophysics Data System (ADS)

    Peng, Haoran; Chen, Yuzeng; Liu, Feng

    2015-11-01

    Applying the regular solution model, the Gibbs free energy of mixing for substitutional binary alloy system was constructed. Then, thermodynamic and kinetic parameters, e.g., driving force and solute drag force, controlling nanoscale grain growth of substitutional binary alloy systems were derived and compared to their generally accepted definitions and interpretations. It is suggested that for an actual grain growth process, the classical driving force P = γ/D ( γ the grain boundary (GB) energy, D the grain size) should be replaced by a new expression, i.e., P^' = γ /D - Δ P . Δ P represents the energy required to adjust nonequilibrium solute distribution to equilibrium solute distribution, which is equivalent to the generally accepted solute drag force impeding GB migration. By incorporating the derived new driving force for grain growth into the classical grain growth model, the reported grain growth behaviors of nanocrystalline Fe-4at. pct Zr and Pd-19at. pct Zr alloys were analyzed. On this basis, the effect of thermodynamic and kinetic parameters ( i.e., P, Δ P and the GB mobility ( M GB)) on nanoscale grain growth, were investigated. Upon grain growth, the decrease of P is caused by the reduction of γ as a result of solute segregation in GBs; the decrease of Δ P is, however, due to the decrease of grain growth velocity; whereas the decrease of M GB is attributed to the enhanced difference of solute molar fractions between the bulk and the GBs as well as the increased activation energy for GB diffusion.

  11. Distribution of photoperiod-insensitive alleles Ppd-B1a and Ppd-D1a and their effect on heading time in Japanese wheat cultivars.

    PubMed

    Seki, Masako; Chono, Makiko; Matsunaka, Hitoshi; Fujita, Masaya; Oda, Shunsuke; Kubo, Katashi; Kiribuchi-Otobe, Chikako; Kojima, Hisayo; Nishida, Hidetaka; Kato, Kenji

    2011-12-01

    The genotypes of photoperiod response genes Ppd-B1 and Ppd-D1 in Japanese wheat cultivars were determined by a PCR-based method, and heading times were compared among genotypes. Most of the Japanese wheat cultivars, except those from the Hokkaido region, carried the photoperiod-insensitive allele Ppd-D1a, and heading was accelerated 10.3 days compared with the Ppd-D1b genotype. Early cultivars with Ppd-D1a may have been selected to avoid damage from preharvest rain. In the Hokkaido region, Ppd-D1a frequency was lower and heading date was late regardless of Ppd-D1 genotype, suggesting another genetic mechanism for late heading in Hokkaido cultivars. In this study, only 11 cultivars proved to carry Ppd-B1a, and all of them carried another photoperiod-insensitive allele, Ppd-D1a. The Ppd-B1a/Ppd-D1a genotype headed 6.7 days earlier than the Ppd-B1b/Ppd-D1a genotype, indicating a significant effect of Ppd-B1a in the genetic background with Ppd-D1a. Early-maturity breeding in Japan is believed to be accelerated by the introduction of the Ppd-B1a allele into medium-heading cultivars carrying Ppd-D1a. Pedigree analysis showed that Ppd-B1a in three extra-early commercial cultivars was inherited from 'Shiroboro 21' by early-heading Chugoku lines bred at the Chugoku Agriculture Experimental Station.

  12. Leveraging the Happy Meal Effect: Substituting Food with Modest Nonfood Incentives Decreases Portion Size Choice

    PubMed Central

    Reimann, Martin; Bechara, Antoine; MacInnis, Deborah

    2015-01-01

    Despite much effort to decrease food intake by altering portion sizes, “super-sized” meals are the preferred choice of many. This research investigated the extent to which individuals can be subtly incentivized to choose smaller portion sizes. Three randomized experiments (2 in the lab and 1 in the field) established that individuals’ choice of full-sized food portions is reduced when they are given the opportunity to choose a half-sized version with a modest nonfood incentive. This substitution effect was robust across different nonfood incentives, foods, populations, and time. Experiment 1 established the effect with children, using inexpensive headphones as nonfood incentives. Experiment 2—a longitudinal study across multiple days—generalized this effect with adults, using the mere chance to win either gift cards or frequent flyer miles as nonfood incentives. Experiment 3 demonstrated the effect among actual restaurant customers who had originally planned to eat a full-sized portion, using the mere chance to win small amounts of money. Our investigation broadens the psychology of food portion choice from perceptual and social factors to motivational determinants. PMID:26372082

  13. Effects of heteroatoms on electronic states of divanadium-substituted γ-Keggin-type polyoxometalates.

    PubMed

    Uehara, Kazuhiro; Miyachi, Takuya; Nakajima, Takahito; Mizuno, Noritaka

    2014-04-07

    Effects of heteroatoms on electronic states of divanadium-substituted γ-Keggin-type polyoxometalates (TBA)4[γ-XV2W10O38(μ-OH)(μ-OR)] (X = Ge, Si; R = Me, Et, n-Pr, H; TBA = tetra(n-butyl)ammonium) and (TBA)4[γ-XV2W10O38(μ-O)] (X = Ge, Si) were investigated, using a combination of nuclear magnetic resonance spectroscopy and density functional theory (DFT) calculations. Both the substitution of SiO4 heteroatom units with larger GeO4 ones and the introduction of more electronegative alkoxo groups in place of hydroxo groups resulted in deshielding of the vanadium nuclei. DFT calculations using the Def2-SVP basis set at TPSSh level of theory could well-reproduce the anionic moieties of a series of divanadium-substituted γ-Keggin-type polyoxometalates, and the estimated chemical shifts approximately reproduced the experimental ones with the individual gauge localized orbital method (SO-IGLO) taking the spin-orbit interaction into account. The magnetic shielding (σ) consists of σd + σp + σSD + σFC, where σd, σp, σSD, and σFC are diamagnetic, paramagnetic, spin-dipolar, and Fermi contact terms, respectively. The σp changed much among (TBA)4[γ-XV2W10O38(μ-OH)2], (TBA)4[γ-XV2W10O38(μ-OH)(μ-OR)], and (TBA)4[γ-XV2W10O38(μ-O)], while σd, σSD, and σFC did not change much. Therefore, the σp largely contributed to the magnetic shielding. Moreover, σp consisted of the occupied-occupied transitions (s-terms) and the occupied-virtual ones (u-terms), and the u-terms were predominant for σp. The most contributing occupied localized orbital consisted of the dz(2) orbital of vanadium, the pz orbital of terminal oxygen related to the V═O bond, and the pz orbital of oxygen of the XO4 unit, whereas the two virtual localized orbitals consisted of the dyz orbital of vanadium and the py orbital of terminal oxygen. Analysis of the structural and electronic characteristics of a series of divanadium-substituted γ-Keggin-type POMs revealed a linear correlation

  14. Selection of dinB Alleles Suppressing Survival Loss upon dinB Overexpression in Escherichia coli

    PubMed Central

    Benson, Ryan W.; Cafarelli, Tiziana M.; Rands, Thomas J.; Lin, Ida

    2014-01-01

    Escherichia coli strains overproducing DinB undergo survival loss; however, the mechanisms regulating this phenotype are poorly understood. Here we report a genetic selection revealing DinB residues essential to effect this loss-of-survival phenotype. The selection uses strains carrying both an antimutator allele of DNA polymerase III (Pol III) α-subunit (dnaE915) and either chromosomal or plasmid-borne dinB alleles. We hypothesized that dnaE915 cells would respond to DinB overproduction differently from dnaE+ cells because the dnaE915 allele is known to have an altered genetic interaction with dinB+ compared to its interaction with dnaE+. Notably, we observe a loss-of-survival phenotype in dnaE915 strains with either a chromosomal catalytically inactive dinB(D103N) allele or a low-copy-number plasmid-borne dinB+ upon DNA damage treatment. Furthermore, we find that the loss-of-survival phenotype occurs independently of DNA damage treatment in a dnaE915 strain expressing the catalytically inactive dinB(D103N) allele from a low-copy-number plasmid. The selective pressure imposed resulted in suppressor mutations that eliminated growth defects. The dinB intragenic mutations examined were either base pair substitutions or those that we inferred to be loss of function (i.e., deletions and insertions). Further analyses of selected novel dinB alleles, generated by single-base-pair substitutions in the dnaE915 strain, indicated that these no longer effect loss of survival upon overproduction in dnaE+ strains. These mutations are mapped to specific areas of DinB; this permits us to gain insights into the mechanisms underlying the DinB-mediated overproduction loss-of-survival phenotype. PMID:24914188

  15. The effect of varying short-chain alkyl substitution on the molar absorptivity and quantum yield of cyanine dyes.

    PubMed

    Chapman, Gala; Henary, Maged; Patonay, Gabor

    2011-01-01

    The effect of varying short-chain alkyl substitution of the indole nitrogens on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and fluorescence quantum yields were determined for a set of pentamethine dyes and a set of heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length resulted in no significant change in quantum yield or molar absorptivity. These results may be useful in designing new cyanine dyes for analytical applications and predicting their spectroscopic properties.

  16. Effect of carbon substitution on low magnetic field AC losses in MgB 2 single crystals

    NASA Astrophysics Data System (ADS)

    Ciszek, M.; Rogacki, K.; Karpiński, J.

    2011-11-01

    The DC magnetization and AC magnetic susceptibilities were measured for MgB2 single crystals, unsubstituted and carbon substituted with the composition of Mg(B0.94C0.06)2. AC magnetic losses were derived from the AC susceptibility data as a function of the AC amplitude and the DC bias magnetic field. From the DC magnetization loops critical current densities were derived as a function of temperature and DC field. Results show that the substitution with carbon decreases critical current densities at low external magnetic fields, in contrast to the well known effect of an increase of the critical current densities at higher magnetic fields.

  17. Allele Specific Locked Nucleic Acid Quantitative PCR (ASLNAqPCR): An Accurate and Cost-Effective Assay to Diagnose and Quantify KRAS and BRAF Mutation

    PubMed Central

    Morandi, Luca; de Biase, Dario; Visani, Michela; Cesari, Valentina; De Maglio, Giovanna; Pizzolitto, Stefano; Pession, Annalisa; Tallini, Giovanni

    2012-01-01

    The use of tyrosine kinase inhibitors (TKIs) requires the testing for hot spot mutations of the molecular effectors downstream the membrane-bound tyrosine kinases since their wild type status is expected for response to TKI therapy. We report a novel assay that we have called Allele Specific Locked Nucleic Acid quantitative PCR (ASLNAqPCR). The assay uses LNA-modified allele specific primers and LNA-modified beacon probes to increase sensitivity, specificity and to accurately quantify mutations. We designed primers specific for codon 12/13 KRAS mutations and BRAF V600E, and validated the assay with 300 routine samples from a variety of sources, including cytology specimens. All were analyzed by ASLNAqPCR and Sanger sequencing. Discordant cases were pyrosequenced. ASLNAqPCR correctly identified BRAF and KRAS mutations in all discordant cases and all had a mutated/wild type DNA ratio below the analytical sensitivity of the Sanger method. ASLNAqPCR was 100% specific with greater accuracy, positive and negative predictive values compared with Sanger sequencing. The analytical sensitivity of ASLNAqPCR is 0.1%, allowing quantification of mutated DNA in small neoplastic cell clones. ASLNAqPCR can be performed in any laboratory with real-time PCR equipment, is very cost-effective and can easily be adapted to detect hot spot mutations in other oncogenes. PMID:22558339

  18. The effectiveness of opioid substitution treatments for patients with opioid dependence: a systematic review and multiple treatment comparison protocol

    PubMed Central

    2014-01-01

    Background Opioids are psychoactive analgesic drugs prescribed for pain relief and palliative care. Due to their addictive potential, effort and vigilance in controlling prescriptions is needed to avoid misuse and dependence. Despite the effort, the prevalence of opioid use disorder continues to rise. Opioid substitution therapies are commonly used to treat opioid dependence; however, there is minimal consensus as to which therapy is most effective. Available treatments include methadone, heroin, buprenorphine, as well as naltrexone. This systematic review aims to assess and compare the effect of all available opioid substitution therapies on the treatment of opioid dependence. Methods/Design The authors will search Medline, EMBASE, PubMed, PsycINFO, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry, World Health Organization International Clinical Trials Registry Platform Search Portal, and the National Institutes for Health Clinical Trials Registry. The title, abstract, and full-text screening will be completed in duplicate. When appropriate, multiple treatment comparison Bayesian meta-analytic methods will be performed to deduce summary statistics estimating the effectiveness of all opioid substitution therapies in terms of retention and response to treatment (as measured through continued opioid abuse). Discussion Using evidence gained from this systematic review, we anticipate disseminating an objective review of the current available literature on the effectiveness of all opioid substitution therapies for the treatment of opioid use disorder. The results of this systematic review are imperative to the further enhancement of clinical practice in addiction medicine. Systematic review registration PROSPERO CRD42013006507. PMID:25239213

  19. 2-Substituted 3β-Aryltropane Cocaine Analogs Produce Atypical Effects without Inducing Inward-Facing Dopamine Transporter Conformations

    PubMed Central

    Hong, Weimin C.; Kopajtic, Theresa A.; Xu, Lifen; Lomenzo, Stacey A.; Jean, Bernandie; Madura, Jeffry D.; Surratt, Christopher K.; Trudell, Mark L.

    2016-01-01

    Previous structure-activity relationship studies indicate that a series of cocaine analogs, 3β-aryltropanes with 2β-diarylmethoxy substituents, selectively bind to the dopamine transporter (DAT) with nanomolar affinities that are 10-fold greater than the affinities of their corresponding 2α-enantiomers. The present study compared these compounds to cocaine with respect to locomotor effects in mice, and assessed their ability to substitute for cocaine (10 mg/kg, i.p.) in rats trained to discriminate cocaine from saline. Despite nanomolar DAT affinity, only the 2β-Ph2COCH2-3β-4-Cl-Ph analog fully substituted for cocaine-like discriminative effects. Whereas all of the 2β compounds increased locomotion, only the 2β-(4-ClPh)PhCOCH2-3β-4-Cl-Ph analog had cocaine-like efficacy. None of the 2α-substituted compounds produced either of these cocaine-like effects. To explore the molecular mechanisms of these drugs, their effects on DAT conformation were probed using a cysteine-accessibility assay. Previous reports indicate that cocaine binds with substantially higher affinity to the DAT in its outward (extracellular)- compared with inward-facing conformation, whereas atypical DAT inhibitors, such as benztropine, have greater similarity in affinity to these conformations, and this is postulated to explain their divergent behavioral effects. All of the 2β- and 2α-substituted compounds tested altered cysteine accessibility of DAT in a manner similar to cocaine. Furthermore, molecular dynamics of in silico inhibitor-DAT complexes suggested that the 2-substituted compounds reach equilibrium in the binding pocket in a cocaine-like fashion. These behavioral, biochemical, and computational results show that aryltropane analogs can bind to the DAT and stabilize outward-facing DAT conformations like cocaine, yet produce effects that differ from those of cocaine. PMID:26769919

  20. Effects of Phosphine-Carbene Substitutions on the Electrochemical and Thermodynamic Properties of Nickel Complexes

    SciTech Connect

    Galan, Brandon R.; Wiedner, Eric S.; Helm, Monte L.; Linehan, John C.; Appel, Aaron M.

    2014-05-12

    Nickel(II) complexes containing chelating N-heterocyclic carbene-phosphine ligands ([NiL2](BPh4)2, for which L = [MeIm(CH2)2PR2]) have been synthesized for the purpose of studying how this class of ligand effects the electrochemical properties compared to the nickel bis- diphosphine analogues. The nickel complexes were synthesized and characterized by x-ray crystallography and electrochemical methods. Based on the half wave potentials (E1/2), substitution of an NHC for one of the phosphines in a diphoshine ligand results in shifts in potential to 0.6 V to 1.2 V more negative than the corresponding nickel bis-diphosphine complexes. These quantitative results highlight the substantial effect that NHC ligands can have upon the electronic properties of the metal complexes. BRG, JCL, and AMA acknowledge the support by the US Department of Energy Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. MLH acknoledges the support of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  1. Pleiotropic effects of hemagglutinin amino acid substitutions of H5 influenza escape mutants

    SciTech Connect

    Rudneva, Irina A.; Timofeeva, Tatiana A.; Ignatieva, Anna V.; Shilov, Aleksandr A.; Krylov, Petr S.; Ilyushina, Natalia A.; Kaverin, Nikolai V.

    2013-12-15

    In the present study we assessed pleiotropic characteristics of the antibody-selected mutations. We examined pH optimum of fusion, temperatures of HA heat inactivation, and in vitro and in vivo replication kinetics of the previously obtained influenza H5 escape mutants. Our results showed that HA1 N142K mutation significantly lowered the pH of fusion optimum. Mutations of the escape mutants located in the HA lateral loop significantly affected H5 HA thermostability (P<0.05). HA changes at positions 131, 144, 145, and 156 and substitutions at positions 131, 142, 145, and 156 affected the replicative ability of H5 escape mutants in vitro and in vivo, respectively. Overall, a co-variation between antigenic specificity and different HA phenotypic properties has been demonstrated. We believe that the monitoring of pleiotropic effects of the HA mutations found in H5 escape mutants is essential for accurate prediction of mutants with pandemic potential. - Highlights: • HA1 N142K mutation significantly lowered the pH of fusion optimum. • Mutations located in the HA lateral loop significantly affected H5 HA thermostability. • HA changes at positions 131, 142, 144, 145, and 156 affected the replicative ability of H5 mutants. • Acquisition of glycosylation site could lead to the emergence of multiple pleiotropic effects.

  2. Design, synthesis, and anti-melanogenic effects of (E)-2-benzoyl-3-(substituted phenyl)acrylonitriles

    PubMed Central

    Yun, Hwi Young; Kim, Do Hyun; Son, Sujin; Ullah, Sultan; Kim, Seong Jin; Kim, Yeon-Jeong; Yoo, Jin-Wook; Jung, Yunjin; Chun, Pusoon; Moon, Hyung Ryong

    2015-01-01

    Background Tyrosinase is the most prominent target for inhibitors of hyperpigmentation because it plays a critical role in melaninogenesis. Although many tyrosinase inhibitors have been identified, from both natural and synthetic sources, there remains a considerable demand for novel tyrosinase inhibitors that are safer and more effective. Methods (E)-2-Benzoyl-3-(substituted phenyl)acrylonitriles (BPA analogs) with a linear β-phenyl-α,β-unsaturated carbonyl scaffold were designed and synthesized as potential tyrosinase inhibitors. We evaluated their effects on cellular tyrosinase activity and melanin biosynthesis in murine B16F10 melanoma cells and their ability to inhibit mushroom tyrosinase activity. Results BPA analogs exhibited inhibitory activity against mushroom tyrosinase. In particular, BPA13 significantly suppressed melanin biosynthesis and inhibited cellular tyrosinase activity in B16F10 cells in a dose-dependent manner. A docking study revealed that BPA13 had higher binding affinity for tyrosinase than kojic acid. Conclusion BPA13, which possesses a linear β-phenyl-α,β-unsaturated carbonyl scaffold, is a potential candidate skin-whitening agent and treatment for diseases associated with hyperpigmentation. PMID:26347064

  3. SSR allelic variation in almond (Prunus dulcis Mill.).

    PubMed

    Xie, Hua; Sui, Yi; Chang, Feng-Qi; Xu, Yong; Ma, Rong-Cai

    2006-01-01

    Sixteen SSR markers including eight EST-SSR and eight genomic SSRs were used for genetic diversity analysis of 23 Chinese and 15 international almond cultivars. EST- and genomic SSR markers previously reported in species of Prunus, mainly peach, proved to be useful for almond genetic analysis. DNA sequences of 117 alleles of six of the 16 SSR loci were analysed to reveal sequence variation among the 38 almond accessions. For the four SSR loci with AG/CT repeats, no insertions or deletions were observed in the flanking regions of the 98 alleles sequenced. Allelic size variation of these loci resulted exclusively from differences in the structures of repeat motifs, which involved interruptions or occurrences of new motif repeats in addition to varying number of AG/CT repeats. Some alleles had a high number of uninterrupted repeat motifs, indicating that SSR mutational patterns differ among alleles at a given SSR locus within the almond species. Allelic homoplasy was observed in the SSR loci because of base substitutions, interruptions or compound repeat motifs. Substitutions in the repeat regions were found at two SSR loci, suggesting that point mutations operate on SSRs and hinder the further SSR expansion by introducing repeat interruptions to stabilize SSR loci. Furthermore, it was shown that some potential point mutations in the flanking regions are linked with new SSR repeat motif variation in almond and peach.

  4. Identification of 2127 new HLA class I alleles in potential stem cell donors from Germany, the United States and Poland.

    PubMed

    Hernández-Frederick, C J; Giani, A S; Cereb, N; Sauter, J; Silva-González, R; Pingel, J; Schmidt, A H; Ehninger, G; Yang, S Y

    2014-03-01

    We describe 2127 new human leukocyte antigen (HLA) class I alleles found in registered stem cell donors. These alleles represent 28.9% of the currently known class I alleles. Comparing new allele sequences to homologous sequences, we found 68.1% nonsynonymous nucleotide substitutions, 28.9% silent mutations and 3.0% nonsense mutations. Many substitutions occurred at positions that have not been known to be polymorphic before. A large number of HLA alleles and nucleotide variations underline the extreme diversity of the HLA system. Strikingly, 156 new alleles were found not only multiple times, but also in carriers of various parentage, suggesting that some new alleles are not necessarily rare. Moreover, new alleles were found especially often in minority donors. This emphasizes the benefits of specifically recruiting such groups of individuals.

  5. CKM Gene G (Ncoi-) Allele Has a Positive Effect on Maximal Oxygen Uptake in Caucasian Women Practicing Sports Requiring Aerobic and Anaerobic Exercise Metabolism

    PubMed Central

    Gronek, Piotr; Holdys, Joanna; Kryściak, Jakub; Stanisławski, Daniel

    2013-01-01

    The search for genes with a positive influence on physical fitness is a difficult process. Physical fitness is a trait determined by multiple genes, and its genetic basis is then modified by numerous environmental factors. The present study examines the effects of the polymorphism of creatine kinase (CKM) gene on VO2max – a physiological index of aerobic capacity of high heritability. The study sample consisted of 154 men and 85 women, who were students of the University School of Physical Education in Poznań and athletes practicing various sports, including members of the Polish national team. The study revealed a positive effect of a rare G (NcoI−) allele of the CKM gene on maximal oxygen uptake in Caucasian women practicing sports requiring aerobic and anaerobic exercise metabolism. Also a tendency was noted in individuals with NcoI−/− (GG) and NcoI−/+ (GA) genotypes to reach higher VO2max levels. PMID:24511349

  6. CKM Gene G (Ncoi-) Allele Has a Positive Effect on Maximal Oxygen Uptake in Caucasian Women Practicing Sports Requiring Aerobic and Anaerobic Exercise Metabolism.

    PubMed

    Gronek, Piotr; Holdys, Joanna; Kryściak, Jakub; Stanisławski, Daniel

    2013-12-18

    The search for genes with a positive influence on physical fitness is a difficult process. Physical fitness is a trait determined by multiple genes, and its genetic basis is then modified by numerous environmental factors. The present study examines the effects of the polymorphism of creatine kinase (CKM) gene on VO2max - a physiological index of aerobic capacity of high heritability. The study sample consisted of 154 men and 85 women, who were students of the University School of Physical Education in Poznań and athletes practicing various sports, including members of the Polish national team. The study revealed a positive effect of a rare G (NcoI-) allele of the CKM gene on maximal oxygen uptake in Caucasian women practicing sports requiring aerobic and anaerobic exercise metabolism. Also a tendency was noted in individuals with NcoI-/- (GG) and NcoI-/+ (GA) genotypes to reach higher VO2max levels.

  7. EFFECT OF A FERROCENYL SUBSTITUTE ON THE FUNCTIONAL GROUPS IN THE BENZENE RING,

    DTIC Science & Technology

    and ferrocenylphenol with phenol and p-hydroxydiphenyl (p- phenylphenol ), indicating that the ferrocenyl group introduced into the benzene ring behaves as a distinctly expressed substitute of the first order.

  8. Pressure effect on structural and vibrational properties of Sm-substituted BiFeO3

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Jie; Chen, Xiao-Kun; Zhang, Jing; Liu, Jing; Xiao, Wan-Sheng; Wu, Zhigang; Chen, Xiao-Jia

    2013-10-01

    The structural and vibrational properties of 5% Sm-substituted BiFeO3 under pressure are investigated using synchrotron X-ray diffraction and Raman scattering measurements. The results yield the pressure-induced structural phase transitions from the polar R3c phase to the orthorhombic Pnma phase commencing at 3.9 and being complete at 7.6 GPa, where there is a region of the coexistence of the R3c and Pnma phases. This structural transition is companied by the ferroelectric-paraelectric transition for the Sm-substituted BiFeO3. We find that the Sm substitution leads to lower transition pressure compared to that of the pure BiFeO3 system due to the substitution-induced chemical pressure. Our results do not suggest the pressure-induced reentrance of ferroelectricity in the model multiferroic BiFeO3 in the pressure range studied.

  9. Effects of electron acceptors and radical scavengers on nonchain radical nucleophilic substitution reactions

    SciTech Connect

    Xianman Zhang; Dilun Yang; Youcheng Liu )

    1993-01-01

    The yields of reaction products from thermal nucleophilic substitution reactions in dimethyl sulfoxide (DMSO) of six o- and p-nitrohalobenzenes with the sodium salt of ethyl [alpha]-cyanoacetate carbanion [Na[sup +][sup [minus

  10. Effects of Pro --> peptoid residue substitution on cell selectivity and mechanism of antibacterial action of tritrpticin-amide antimicrobial peptide.

    PubMed

    Zhu, Wan Long; Lan, Hongliang; Park, Yoonkyung; Yang, Sung-Tae; Kim, Jae Il; Park, Il-Seon; You, Ho Jin; Lee, Jung Sup; Park, Yong Sun; Kim, Yangmee; Hahm, Kyung-Soo; Shin, Song Yub

    2006-10-31

    To investigate the effect of Pro --> peptoid residue substitution on cell selectivity and the mechanism of antibacterial action of Pro-containing beta-turn antimicrobial peptides, we synthesized tritrpticin-amide (TP, VRRFPWWWPFLRR-NH(2)) and its peptoid residue-substituted peptides in which two Pro residues at positions 5 and 9 are replaced with Nleu (Leu peptoid residue), Nphe (Phe peptoid residue), or Nlys (Lys peptoid residue). Peptides with Pro --> Nphe (TPf) or Pro --> Nleu substitution (TPl) retained antibacterial activity but had significantly higher toxicity to mammalian cells. In contrast, Pro --> Nlys substitution (TPk) increased the antibacterial activity but decreased the toxicity to mammalian cells. Tryptophan fluorescence studies indicated that the bacterial cell selectivity of TPk is closely correlated with a preferential interaction with negatively charged phospholipids. Interestingly, TPk was much less effective at depolarizing of the membrane potential of Staphylococus aureus and Escherichia coli spheroplasts and causing the leakage of a fluorescent dye entrapped within negatively charged vesicles. Furthermore, confocal laser-scanning microscopy showed that TPk effectively penetrated the membrane of both E. coli and S. aureus and accumulated in the cytoplasm, whereas TP and TPf did not penetrate the cell membrane but remained outside or on the cell membrane. These results suggest that the bactericidal action of TPk is due to inhibition of the intracellular components after penetration of the bacterial cell membrane. In addition, TPK with Lys substitution effectively depolarized the membrane potential of S. aureus and E. coli spheroplasts. TPK induced rapid and effective dye leakage from bacterial membrane-mimicking liposomes and did not penetrate the bacterial cell membranes. These results suggested that the ability of TPk to penetrate the bacterial cell membranes appears to involve the dual effects that are related to the increase in the

  11. Effects of Cdh23 single nucleotide substitutions on age-related hearing loss in C57BL/6 and 129S1/Sv mice and comparisons with congenic strains

    PubMed Central

    Johnson, Kenneth R.; Tian, Cong; Gagnon, Leona H.; Jiang, Haiyan; Ding, Dalian; Salvi, Richard

    2017-01-01

    A single nucleotide variant (SNV) of the cadherin 23 gene (Cdh23c.753A), common to many inbred mouse strains, accelerates age-related hearing loss (AHL) and can worsen auditory phenotypes of other mutations. We used homologous recombination in C57BL/6 NJ (B6N) and 129S1/SvImJ (129S1) embryonic stem cells to engineer mouse strains with reciprocal single base pair substitutions (B6-Cdh23c.753A>G and 129S1-Cdh23c.753G>A). We compared ABR thresholds and cochlear pathologies of these SNV mice with those of congenic (B6.129S1-Cdh23Ahl+ and 129S1.B6-Cdh23ahl) and parental (B6N and 129S1) strain mice. Results verified the protective effect of the Cdh23c.753G allele, which prevented high frequency hearing loss in B6 mice to at least 18 months of age, and the AHL-inducing effect of the Cdh23c.753A allele, which worsened hearing loss in 129S1 mice. ABR thresholds differed between 129S-Cdh23c.753A SNV and 129S1.B6-Cdh23ahl congenic mice, and a linkage backcross involving these strains localized a Chr 10 QTL contributing to the difference. These results illustrate the large effects that strain background and congenic regions have on the hearing loss associated with Cdh23c.753alleles. Importantly, the B6-Cdh23c.753Gstrain can be used to eliminate the confounding influence of the Cdh23c.753Avariant in hearing studies of B6 mice and mutant mice on the B6 background. PMID:28287619

  12. Effects of controlled overburden placement on topsoil substitute quality and bond release: Phase 3. Final report

    SciTech Connect

    Burger, J.; Daniels, W.L.; Haering, K.; Torbert, J.

    1990-10-17

    The results leave little doubt that carefully selected overburden materials can be used to form productive topsoil substitutes in Applachian region. As long as potentially acid-forming materials are eliminated from consideration, carefully selected, graded and amended overburden materials can serve as topsoil substitute materials over and beyond the 5-year bond period. In the absence of organic amendments, the establishment and maintenance of a vigorous legume component in the forage stand is crucial.

  13. RNA-Seq Analysis of Allele-Specific Expression, Hybrid Effects, and Regulatory Divergence in Hybrids Compared with Their Parents from Natural Populations

    PubMed Central

    Bell, Graeme D.M.; Kane, Nolan C.; Rieseberg, Loren H.; Adams, Keith L.

    2013-01-01

    Hybridization is a prominent process among natural plant populations that can result in phenotypic novelty, heterosis, and changes in gene expression. The effects of intraspecific hybridization on F1 hybrid gene expression were investigated using parents from divergent, natural populations of Cirsium arvense, an invasive Compositae weed. Using an RNA-seq approach, the expression of 68,746 unigenes was quantified in parents and hybrids. The expression levels of 51% of transcripts differed between parents, a majority of which had less than 1.25× fold-changes. More unigenes had higher expression in the invasive parent (P1) than the noninvasive parent (P2). Of those that were divergently expressed between parents, 10% showed additive and 81% showed nonadditive (transgressive or dominant) modes of gene action in the hybrids. A majority of the dominant cases had P2-like expression patterns in the hybrids. Comparisons of allele-specific expression also enabled a survey of cis- and trans-regulatory effects. Cis- and trans-regulatory divergence was found at 70% and 68% of 62,281 informative single-nucleotide polymorphism sites, respectively. Of the 17% of sites exhibiting both cis- and trans-effects, a majority (70%) had antagonistic regulatory interactions (cis x trans); trans-divergence tended to drive higher expression of the P1 allele, whereas cis-divergence tended to increase P2 transcript abundance. Trans-effects correlated more highly than cis with parental expression divergence and accounted for a greater proportion of the regulatory divergence at sites with additive compared with nonadditive inheritance patterns. This study explores the nature of, and types of mechanisms underlying, expression changes that occur in upon intraspecific hybridization in natural populations. PMID:23677938

  14. Thermal substitution and aerobic efficiency: measuring and predicting effects of heat balance on endotherm diving energetics.

    PubMed

    Lovvorn, J R

    2007-11-29

    For diving endotherms, modelling costs of locomotion as a function of prey dispersion requires estimates of the costs of diving to different depths. One approach is to estimate the physical costs of locomotion (Pmech) with biomechanical models and to convert those estimates to chemical energy needs by an aerobic efficiency (eta=Pmech/Vo2) based on oxygen consumption (Vo2) in captive animals. Variations in eta with temperature depend partly on thermal substitution, whereby heat from the inefficiency of exercising muscles or the heat increment of feeding (HIF) can substitute for thermogenesis. However, measurements of substitution have ranged from lack of detection to nearly complete use of exercise heat or HIF. This inconsistency may reflect (i) problems in methods of calculating substitution, (ii) confounding mechanisms of thermoregulatory control, or (iii) varying conditions that affect heat balance and allow substitution to be expressed. At present, understanding of how heat generation is regulated, and how heat is transported among tissues during exercise, digestion, thermal challenge and breath holding, is inadequate for predicting substitution and aerobic efficiencies without direct measurements for conditions of interest. Confirming that work rates during exercise are generally conserved, and identifying temperatures at those work rates below which shivering begins, may allow better prediction of aerobic efficiencies for ecological models.

  15. The effect of N-substituted alkyl groups on the anticonvulsant activities ofN-Cbz-alpha-amino-N-alkylsuccinimides.

    PubMed

    Lee, J; Son, K; Jung, K; Choi, J; Park, M

    1997-02-01

    For the purpose of defining the effects of theN-substituted alkyl groups on the anticonvulsant activities ofN-Cbz-alpha-aminosuccinimides, various (R)-and(S)-N-alkyl substitutedN-Cbz-alpha-aminosuccinimides (1 and2) were prepared from the corresponding (R)-and(S)-N-Cbz-aspartic acid by using known reaction and were evaluated the anticonvulsant activies in the MES and PTZ tests, including their neurotoxicities. The most active compound in the MES test was(R)-N-Cbz-alpha-amino-N-methylsuccinimide (1b) (ED(50)=52.5 mg/kg, Pl-3.2). And in case of the PTZ test,(R)-N-Cbz-alpha-amino-N-ethylsuccinimide (1c) was the most active compound (ED(50)=32.5 mg/kg, Pl=3.1). The order of anticonvulsant activities of these compounds against the MES test, as judged from the ED(50) values for theR series (1), wasN-methyl >N-isobutyl > non-substituted >N-ethyl,N-allyl >N-benzyl compound; for theS series (2)N-methyl >N-allyl > non-substituted >N-isobutyl >N-ethyl >N-benzyl compound. The anticonvulsant activities in the PTZ tests of these compounds exhibited somewhat different pattern; for theR series (1)N-ethyl >N-methyl >N-isobutyl> non-substituted >N-allyl >N-benzyl compound in order of decreasing activity; forS series (2)N-ethyl >N-allyl, non-substituted >N-isobutyl >N-methyl >N-benzyl compound in order of decreasing activity.

  16. Collective vibrational effects in hydrogen bonded liquid amides and proteins studied by isotopic substitution

    NASA Astrophysics Data System (ADS)

    Nielsen, O. F.; Johansson, C.; Christensen, D. H.; Hvidt, S.; Flink, J.; Høime Hansen, S.; Poulsen, F.

    2000-09-01

    Raman spectroscopy is used to study the fast dynamics of simple liquid amides and proteins. Raman spectra in the visible region of liquid amides are obtained with a triple additive scanning monochromator, whereas FT-Raman technique is used in the near-IR region in order to avoid fluorescence from impurities in the proteins. Raman spectra are shown in the amide-I region of HCONHCH 3 ( N-methylformamide with all isotopes in their natural abundance), H 13CONHCH 3, HC 18ONHCH 3, human growth hormone, frog tropomyosin and chymotrypsin inhibitor 2 including C-13 and N-15 enriched samples of the latter. Resonance energy transfer (RET) between amide molecules gives rise to a non-coincidence effect of the anisotropic and the isotropic components of the amide-I band. This effect influences the band position in mixtures of liquid amide isotopomers. A further spectral feature caused by collective vibrational modes in the hydrogen bonded liquid amides is named coalescence of bands in mixtures of isotopomers (CBMI). The result of this effect is that only one band is found in mixtures of isotopomers where bands at different frequencies are observed for each of the isotopomers. A similar effect may account for the observation of protein amide-I bands with frequencies dependent only on the secondary structure of the protein and not on the amino acid residues. RET and CBMI are due to a collectivity of vibrational modes in different amide molecules. This collectivity may be related to a cooperativity of hydrogen bonds. A low-frequency band around 100 cm -1 is observed in hydrogen bonded liquid amides and proteins. Isotopic substitution shows that the mode corresponding to this band involves displacements of atoms in hydrogen bonds. This mode may drive a breaking of the hydrogen bond.

  17. Selenium substitution effect on crystal structure of stibnite (Sb2S3)

    NASA Astrophysics Data System (ADS)

    Kyono, Atsushi; Hayakawa, Akinobu; Horiki, Mayumi

    2015-06-01

    Composition dependence of the crystal structure between stibnite and antimonselite is investigated by using the single-crystal X-ray diffraction and the ab initio calculation methods to clarify the Se substitution effect on the crystal structure, especially focusing on the stereochemical behavior of Sb 5 s 2 lone-pair electrons. The single-crystal X-ray diffraction measurements indicate no phase change throughout the solid solution range. The lattice parameters of a, b, c and unit cell volume are linearly increased as Se content increases. The lattice parameter variations normalized show an anisotropic expansion that the largest expansion is observed along the a-axis, followed by the c- and b-axes. The large Se atom exhibits a strong site preference for the X(1) and X(3) sites, while the small S atom prefers to occupy the X(2) site. The intra-ribbon Sb(1)-X and Sb(2)-X distances (X = S, Se) are continuously increased with the Se content. The three Sb(1)-X bond distances in the trigonal pyramids are changed within the similar range between 2.52 and 2.68 Å, while the five Sb(2)-X distances in the tetragonal pyramids vary from 2.45 to 2.59 Å, from 2.68 to 2.80 Å, and from 2.86 to 3.00 Å, respectively. With increasing Se content in the solid solution, the inter-ribbon distances where the Sb 5 s 2 LPEs are located monotonously increase as well. However, the variations between the ribbons are considerably smaller than those of intra-ribbon distances. The polyhedral volumes of the Sb(1)X7 and Sb(2)X7 in which the Sb 5 s 2 LPEs are accommodated constantly increase from 35.9 to 40.0 Å3 and from 34.1 to 38.8 Å3, respectively, and these eccentricity parameters decrease from 0.66 to 0.62 and from 0.57 to 0.55. As a result of ab initio calculation, the Sb 5 s orbitals on the Sb(1) atoms remain almost unchanged throughout the solid solution. On the other hand, those on the Sb(2) atoms become smaller with the incorporation of Se. The result gives a more reasonable

  18. Polymorphism of Mhc-DRB alleles in Cercopithecus aethiops (green monkey): generation and functionality.

    PubMed

    Rosal-Sánchez, M; Paz-Artal, E; Moreno-Pelayo, M A; Martínez-Quiles, N; Martínez-Laso, J; Martín-Villa, J M; Arnaiz-Villena, A

    1998-05-01

    DRB genes have been studied for the first time in green monkeys (Cercopithecus aethiops). Eleven new DRB alleles (exon 2, exon 3) have been obtained and sequenced from cDNA. A limited number of lineages have been identified: DRB1*03 (4 alleles), DRB1*07 (3 alleles), DRB5 (1 allele), DRB*w6 (1 allele), and DRB*w7 (2 alleles). The existence of Ceae-DRB1 duplications is supported by the finding of 3 DRB1 alleles in 3 different individuals. Ceae-DRB1*0701 may be non-functional because it bears serine at position 82, which hinders molecule surface expression in mice; the allele is only found in Ceae-DRB duplicated haplotypes. Base changes in cDNA Ceae-DRB alleles are consistent with the generation of polymorphism by point mutations or short segment exchanges between alleles. The eleven green monkey DRB alleles meet the requirements for functionality as antigen-presenting molecules (perhaps, excluding DRB1*0701), since: 1) they have been isolated from cDNA and do not present deletions, insertions or stop codons: 2) structural motifs necessary for a correct folding of the molecule, for the formation of DR/DR dimers and for CD4 interactions are conserved, and 3) the number of non-synonymous substitutions is higher than the number of synonymous substitutions in the peptide binding region (PBR), while the contrary holds true for the non-PBR region.

  19. Effects of 10% biofuel substitution on ground level ozone formation in Bangkok, Thailand

    NASA Astrophysics Data System (ADS)

    Milt, Austin; Milano, Aaron; Garivait, Savitri; Kamens, Richard

    2009-12-01

    The Thai Government's search for alternatives to imported petroleum led to the consideration of mandating 10% biofuel blends (biodiesel and gasohol) by 2012. Concerns over the effects of biofuel combustion on ground level ozone formation in relation to their conventional counterparts need addressing. Ozone formation in Bangkok is explored using a trajectory box model. The model is compared against O 3, NO, and NO 2 time concentration data from air monitoring stations operated by the Thai Pollution Control Department. Four high ozone days in 2006 were selected for modeling. Both the traditional trajectory approach and a citywide average approach were used. The model performs well with both approaches but slightly better with the citywide average. Highly uncertain and missing data are derived within realistic bounds using a genetic algorithm optimization. It was found that 10% biofuel substitution will lead to as much as a 16 ppb peak O 3 increase on these four days compared to a 48 ppb increase due to the predicted vehicle fleet size increase between 2006 and 2012. The approach also suggests that when detailed meteorological data is not available to run three dimensional airshed models, and if the air is stagnant or predominately remains over an urban area during the day, that a simple low cost trajectory analysis of O 3 formation may be applicable.

  20. Correlation effects and electronic properties of Cr-substituted SZn with an intermediate band.

    PubMed

    Tablero, C

    2005-09-15

    A study using first principles of the electronic properties of S32Zn31Cr, a material derived from the SZn host semiconductor where a Cr atom has been substituted for each of the 32 Zn atoms, is presented. This material has an intermediate band sandwiched between the valence and conduction bands of the host semiconductor, which in a formal band-theoretic picture is metallic because the Fermi energy is located within the impurity band. The potential technological application of these materials is that when they are used to absorb photons in solar cells, the efficiency increases significantly with respect to the host semiconductor. An analysis of the gaps, bandwidths, density of states, total and orbital charges, and electronic density is carried out. The main effects of the local-density approximation with a Hubbard term corrections are an increase in the bandwidth, a modification of the relative composition of the five d and p transition-metal orbitals, and a splitting of the intermediate band. The results demonstrate that the main contribution to the intermediate band is the Cr atom. For values of U greater than 6 eV, where U is the empirical Hubbard term U parameter, this band is unfolded, thus creating two bands, a full one below the Fermi energy and an empty one above it, i.e., a metal-insulator transition.

  1. Isotopic effects in the collision of HCN with He: substitution of HCN by DCN

    NASA Astrophysics Data System (ADS)

    Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe

    2015-10-01

    The HCN molecule is among the main tracers of the interstellar medium (ISM) and the observation of its isotopologue DCN should help to understand the physical properties and chemical history of the molecular clouds. We analyse the effects of the substitution of H by D in the collision of HCN with He. The bound levels of the DCN-He complex are reported and compared with the HCN-He levels. The close-coupling equations were solved in the space-fixed frame using the potential energy surface recently published for the HCN-He system. These calculations were performed with two different approaches in which the triatomic molecule was modelized as a rigid rotor or as a rigid bender, the latter approach allowing us to investigate rovibrational transitions. Rovibrational rate coefficients of DCN in collision with He were computed and compared with those for HCN-He. The ratio of the rate coefficients between both isotopologues varies from 0.4 to 3.9 for rotational transitions in the ground vibrational level. In the case of the first l-type doubling transition, we found that the rate coefficients have the same order of magnitude than those for pure rotational transitions. Therefore, in regions of ISM where the first vibrationally excited level of DCN can be populated, l-type doubling transitions are expected to be as important as pure rotational transitions.

  2. Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces*

    PubMed Central

    Zhao, Shi-fang; Dong, Wen-jing; Jiang, Qiao-hong; He, Fu-ming; Wang, Xiao-xiang; Yang, Guo-li

    2013-01-01

    Objective: The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite (Zn-HA) coating, applied by an electrochemical process, on implant osseointegraton in a rabbit model. Methods: A Zn-HA coating or an HA coating was deposited using an electrochemical process. Surface morphology was examined using field-emission scanning electron microscopy. The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). A total of 78 implants were inserted into femurs and tibias of rabbits. After two, four, and eight weeks, femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque (RTQ) tests. Results: Rod-like HA crystals appeared on both implant surfaces. The dimensions of the Zn-HA crystals seemed to be smaller than those of HA. XRD patterns showed that the peaks of both coatings matched well with standard HA patterns. FTIR spectra showed that both coatings consisted of HA crystals. The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks (P<0.05), the bone to implant contact (BIC) at four weeks (P<0.05), and RTQ values after four and eight weeks (P<0.05). Conclusions: The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface. PMID:23733429

  3. Effect of F ions on physical and optical properties of fluorine substituted zinc arsenic tellurite glasses

    NASA Astrophysics Data System (ADS)

    Kareem Ahmmad, Shaik; kondaul, Edu; Rahman, Syed

    2015-02-01

    The effect of substitution of fluoride ions for oxide ions on the physical and optical properties of glass system (20-x) ZnO-xZnF2-40As2O3-40TeO2 where x = 0, 4, 8,12,16,20 mole % were investigated. The samples prepared by melt quenching method under controlled condition. The amorphous nature of these glasses was checked by X-ray diffraction technique. The density was measured according to Archimedes principle. The room temperature absorption spectra of all glass samples were determined using UV-Vis-NIR spectrometer. The thermal behaviour, glass transition temperature and stability of glass samples were studied by a differential scanning calorimetric (DSC). The density reduction of present glasses with ZnF2 concentrations may be due to the low density of ZnF2 compared with that of ZnO. Breaking the oxide network, the cross linking degree of the glass former could be reduced which results in decrease of both Tg and Tx. In the present glass system when F ions replaced by oxygen ions UV-Vis absorption cut-off wavelength decreases. This resulted form the conversion of structural unit in the glass from TeO4 to Te(O,F)4 and then to Te(O, F)3.

  4. Substituted galacturonan from starfruit: Chemical structure and antinociceptive and anti-inflammatory effects.

    PubMed

    Leivas, Carolina L; Nascimento, Leandro F; Barros, Wellinghton M; Santos, Adair R S; Iacomini, Marcello; Cordeiro, Lucimara M C

    2016-03-01

    Starfruit (Averrhoa carambola L.) is an edible tropical fruit, which is usually consumed as a fresh table fruit or as fruit juice. It also exhibits various pharmacological activities. In this study, polysaccharides were extracted with boiling water and purified by freeze-thawing and Fehling treatments. After purification steps, a homogenous fraction was obtained. It was analyzed by sugar composition, gel permeation chromatography, methylation, and two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy analyses. It comprised arabinose (Ara), galactose (Gal), and galacturonic acid (GalA) in a molar ratio of 12.3:1.7:86.0. Methylation and NMR spectroscopy analyses showed that it contained a substituted galacturonan composed of (1→4)-linked α-D-Galp A units branched at O-2 by (1→5)-linked α-L-Araf and terminal α-L-Araf and α-D-Galp A units. The effect of PFSCW (10-300mg/kg, i.p.) on nocifensive behavior induced by intraplantar injection of formalin in mice was evaluated. The fraction demonstrated antinociceptive and anti-inflammatory properties, suggesting that it may be useful in therapeutic intervention for the management of inflammatory pain.

  5. Cp*-Substituted Boron Cations: The Effect of NHC, NHO, and CAAC Ligands.

    PubMed

    Huang, Jih-Sheng; Lee, Wan-Hua; Shen, Chao-Tang; Lin, Ya-Fan; Liu, Yi-Hung; Peng, Shie-Ming; Chiu, Ching-Wen

    2016-12-05

    The effect of a ligand on the electron deficiency and Lewis acidity of the Cp*-substituted boron dication has been investigated experimentally and theoretically. In addition to the reported IMes- and N-heterocyclic olefin (NHO)-stabilized boron dications, the related cyclic alkylamino carbene (CAAC)-coordinated boron mono- and dications have also been synthesized and structurally characterized. An electrochemical study of dications [3a-3c](2+) confirms the higher electron deficiency of the dicationic system than the related boron monocations. Moreover, the presence of a π-acidic CAAC ligand is critical for realizing stable radical species generated from the chemical reduction of boron cations. The nature of the axial ligand also significantly affects the selectivity of the hydride addition reaction of boron dications. While bulky superhydride reacts with [3a-3c](2+) in the same manner to give the cyclic boreniums, [BH4](-) attacks three different electrophilic sites of boron dications: the sp(2) carbon of Cp* of the IMes-coordinated system ([3a](2+)), the central boron atom of the NHO-stabilized analogue ([3b](2+)), and the ylidene carbon of the CAAC-containing boron dication ([3c](2+)).

  6. Effect of the degree of substitution of octenyl succinic anhydride-banana starch on emulsion stability.

    PubMed

    Bello-Pérez, Luis A; Bello-Flores, Christopher A; Nuñez-Santiago, María del Carmen; Coronel-Aguilera, Claudia P; Alvarez-Ramirez, J

    2015-11-05

    Banana starch was esterified with octenylsuccinic anhydride (OSA) at different degree substitution (DS) and used to stabilize emulsions. Morphology, emulsion stability, emulsification index, rheological properties and particle size distribution of the emulsions were tested. Emulsions dyed with Solvent Red 26 showed affinity for the oil phase. Backscattering light showed three regions in the emulsion where the emulsified region was present. Starch concentration had higher effect in the emulsification index (EI) than the DS used in the study because similar values were found with OSA-banana and native starches. However, OSA-banana presented greater stability of the emulsified region. Rheological tests in emulsions with OSA-banana showed G'>G" values and low dependence of G' with the frequency, indicating a dominant elastic response to shear. When emulsions were prepared under high-pressure conditions, the emulsions with OSA-banana starch with different DS showed a bimodal distribution of particle size. The emulsion with OSA-banana starch and the low DS showed similar mean droplet diameter than its native counterpart. In contrast, the highest DS led to the highest mean droplet diameter. It is concluded that OSA-banana starch with DS can be used to stabilize specific emulsion types.

  7. Chemical and electronic characterization of cobalt in Lanthanumperovskites. Effects of Strontium substitution

    SciTech Connect

    Hueso, Jose L.; Holgado, Juan P.; Pereniguez, Rosa; Mun, Simon; Salmeron, Miquel; Caballero, Alfonso

    2009-02-06

    Two different cobaltites, LaCoO{sub 3} and La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}}, have been prepared and characterized by means of high energy Co K-edge and low energy O K-edge X-ray absorption spectroscopy (XAS). The partial substitution of La(III) by Sr(II) species induces important changes in the reactivity and electronic state of the perovskite, while little or no changes can be detected in the formal oxidation state of cobalt atoms. The presence of strontium cations induces two main effects in the chemical and electronic behavior of the perovskite. The charge balance with Sr(II) species is reached by the formation of oxygen vacancies throughout the network, which increases the reactivity of the perovskite, now more reducible than the original LaCoO{sub 3} perovskite. O K-edge XAS experiments indicate that the Sr(II) species cause d electrons of cobalt cations to change from low to high spin configuration. Our data allow us to propose that this change in spin multiplicity is induced by the bigger size of Sr(II) cations, which aligns the Co-O-Co atoms, and favors the overlapping of {pi}-symmetry cobalt and oxygen orbitals, reducing the splitting energy of e{sub g} and t{sub 2g} levels.

  8. Dopamine Receptor Gene DRD4 7-Repeat Allele X Maternal Sensitivity Interaction on Child Externalizing Behavior Problems: Independent Replication of Effects at 18 Months.

    PubMed

    King, Anthony P; Muzik, Maria; Hamilton, Lindsay; Taylor, Alexander B; Rosenblum, Katherine L; Liberzon, Israel

    2016-01-01

    The DRD4 VNTR has been associated with child behavior problems in interaction with maternal insensitivity in European and American cohorts of preschoolers, with the 7-repeat (7R) allele associated with greater problems. We sought to replicate and expand these findings by examining effects on reports of child behavior problems at 18 months. A 63 family sample with data for observed maternal sensitivity ratings, DRD4 VNTR genotype, and maternal report of child behavior problems at 18-months was used in this preliminary analysis. Maternal sensitivity was measured at 6-months of age using laboratory observational measures (free-play and a teaching task). Maternal report of toddler behavior was obtained at 18-months via the standard Child Behavior Checklist, and infant genotype on the DRD4 VNTR was obtained using PCR. Infants carrying the DRD4 7R allele showed greater effects of maternal insensitivity than non-carriers for behavioral problems at 18-months. We replicated previous findings of association of infant DRD4 x maternal sensitivity interactions with child Externalizing problems in the European-ancestry sample (N = 42) in a median split of maternal sensitivity (p = .00011, eta2 = .329) and in regression analyses controlling for maternal age, maternal depression, and child gender in European ancestry (B = -3.4, SE 1.33, p = .01) and the total sample (B = -2.2, SE 1.02, p = .02). Exploratory analyses also found evidence of DRD4 x maternal sensitivity interaction with the CBCL ADHD scale. These findings replicate in an independent cohort DRD4 x maternal insensitivity interaction effect on child externalizing behavior problems at 18 months, further supporting the role of the DRD4 genotype in differential sensitivity to parenting.

  9. Dopamine Receptor Gene DRD4 7-Repeat Allele X Maternal Sensitivity Interaction on Child Externalizing Behavior Problems: Independent Replication of Effects at 18 Months

    PubMed Central

    King, Anthony P.; Muzik, Maria; Hamilton, Lindsay; Taylor, Alexander B.; Rosenblum, Katherine L.; Liberzon, Israel

    2016-01-01

    The DRD4 VNTR has been associated with child behavior problems in interaction with maternal insensitivity in European and American cohorts of preschoolers, with the 7-repeat (7R) allele associated with greater problems. We sought to replicate and expand these findings by examining effects on reports of child behavior problems at 18 months. A 63 family sample with data for observed maternal sensitivity ratings, DRD4 VNTR genotype, and maternal report of child behavior problems at 18-months was used in this preliminary analysis. Maternal sensitivity was measured at 6-months of age using laboratory observational measures (free-play and a teaching task). Maternal report of toddler behavior was obtained at 18-months via the standard Child Behavior Checklist, and infant genotype on the DRD4 VNTR was obtained using PCR. Infants carrying the DRD4 7R allele showed greater effects of maternal insensitivity than non-carriers for behavioral problems at 18-months. We replicated previous findings of association of infant DRD4 x maternal sensitivity interactions with child Externalizing problems in the European-ancestry sample (N = 42) in a median split of maternal sensitivity (p = .00011, eta2 = .329) and in regression analyses controlling for maternal age, maternal depression, and child gender in European ancestry (B = -3.4, SE 1.33, p = .01) and the total sample (B = -2.2, SE 1.02, p = .02). Exploratory analyses also found evidence of DRD4 x maternal sensitivity interaction with the CBCL ADHD scale. These findings replicate in an independent cohort DRD4 x maternal insensitivity interaction effect on child externalizing behavior problems at 18 months, further supporting the role of the DRD4 genotype in differential sensitivity to parenting. PMID:27494520

  10. Transient suppression of MLH1 allows effective single-nucleotide substitution by single-stranded DNA oligonucleotides.

    PubMed

    Dekker, Marleen; de Vries, Sandra; Aarts, Marieke; Dekker, Robert; Brouwers, Conny; Wiebenga, Oliver; de Wind, Niels; Cantelli, Erika; Tonelli, Roberto; Te Riele, Hein

    2011-10-01

    Short synthetic single-stranded oligodeoxyribonucleotides (ssODNs) can be used to introduce subtle modifications into the genome of mouse embryonic stem cells (ESCs). We have previously shown that effective application of ssODN-mediated gene targeting in ESC requires (transient) suppression of DNA mismatch repair (MMR). However, whereas transient down-regulation of the mismatch recognition protein MSH2 allowed substitution of 3 or 4 nucleotides, 1 or 2 nucleotide substitutions were still suppressed. We now demonstrate that single- or dinucleotide substitution can effectively be achieved by transient down-regulation of the downstream MMR protein MLH1. By exploiting highly specific real-time PCR, we demonstrate the feasibility of substituting a single basepair in a non-selectable gene. However, disabling the MMR machinery may lead to inadvertent mutations. To obtain insight into the mutation rate associated with transient MMR suppression, we have compared the impact of transient and constitutive MMR deficiency on the repair of frameshift intermediates at mono- and dinucleotide repeats. Repair at these repeats relied on the substrate specificity and functional redundancy of the MSH2/MSH6 and MSH2/MSH3 MMR complexes. MLH1 knockdown increased the level of spontaneous mutagenesis, but modified ESCs remained germ line competent. Thus, transient MLH1 suppression provides a valuable extension of the MSH2 knockdown strategy, allowing rapid generation of mice carrying single basepair alterations in their genome.

  11. 17O NMR studies of ortho-substituent effects in substituted phenyl tosylates.

    PubMed

    Nummert, Vilve; Mäemets, Vahur; Piirsalu, Mare; Koppel, Ilmar A

    2012-10-01

    (17)O NMR spectra for 35 ortho-, para-, and meta-substituted phenyl tosylates (phenyl 4-methylbenzenesulfonates), 4-CH(3)-C(6)H(4) SO(2)OC(6)H(4)-X, at natural abundance in acetonitrile at 50 °C were recorded. The (17)O NMR chemical shifts, δ((17)O), of the sulfonyl (SO(2)) and the single-bonded phenoxy (OPh) oxygens for para and meta derivatives correlated well with dual substituent parameter treatment using the Taft inductive, σ(I), and resonance, σº(R), constants. The influence of ortho substituents on the sulfonyl oxygen and the single-bonded phenoxy oxygen chemical shifts, δ((17)O), was found to be nicely described by the Charton equation: δ((17)O)(ortho) = δ((17)O)(H) + ρ(I)σ(I) + ρ(R)σ°(R) + δE(s)(B) when the data treatment was performed separately for electron-donating +R substituents and electron-attracting -R substituents. Electron-attracting meta and para substituents in the phenyl moiety caused deshielding while the electron-donating meta, para and ortho +R substituents produce shielding effects on the sulfonyl (SO(2)) and single-bonded phenoxy (OPh) oxygens. The influence of ortho inductive and resonance effects in the case of +R substituents was found to be approximately twice higher than the corresponding influence from the para position. Due to the steric effect of ortho substituents a decrease in shielding of the oxygens at the sulfonyl group (δE(s)(B) > 0, E(s)(B) < 0) was detected.

  12. Sugar substitutes during pregnancy

    PubMed Central

    Pope, Eliza; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Abstract Question I have a pregnant patient who regularly consumes sugar substitutes and she asked me if continuing their use would affect her pregnancy or child. What should I tell her, and are there certain options that are better for use during pregnancy? Answer Although more research is required to fully determine the effects of in utero exposure to sugar substitutes, the available data do not suggest adverse effects in pregnancy. However, it is recommended that sugar substitutes be consumed in moderate amounts, adhering to the acceptable daily intake standards set by regulatory agencies. PMID:25392440

  13. Effect of Element Substitution at V site on Thermoelectric Properties of Aurivillius Phase Bi2VO5.5

    NASA Astrophysics Data System (ADS)

    Kohri, Hitoshi; Yagasaki, Takayoshi

    2016-10-01

    Thermoelectric oxides are suitable at the high temperature range because of chemical stability. Aurivillius compounds are bismuth layered oxides, and known as oxygen ion conductors. The Aurivillius compounds consist of Perovskite layers and Bi-O layers. It is expected that nano-layered structure shows high Seebeck coefficients due to the quantum confinement of carriers in Perovskite layers. It was reported that the Seebeck coefficient of hot pressed specimens for Aurivillius phase Bi2VO5.5 was a high value of -28.3 mVK-1 at 1010 K, and the electrical resistivity of one was also a high value of 0.033 Ωm at 1010 K. In this paper, the effect of element substitution at the V site on thermoelectric properties of Aurivillius phase Bi2VO5.5 was investigated. Bi2V1- x M x O5.5 (M = Cr, Mo, W x = 0, 0.05, 0.1, 0.2) were prepared by solid-state reaction. The electrical resistivity of Cr-substituted specimens were indicated at larger values than the ones for unsubstituted specimens over the measurement temperature range. The resistivity above 800 K was reduced by substitution of W or Mo. W as a substituted element was effective for reducing the thermal conductivity of Bi2VO5.5. The maximum value of the dimensionless figure of merit ZT was 0.05 at 799 K for Bi2V0.8Mo0.2O5.5 and at 902 K for Bi2V0.8W0.1O5.5. The maximum ZT of an unsubstituted sample was 0.02 at 993 K. From these results, it was found that tungsten or molybdenum substitution was effective to improve ZT for Aurivillius phase Bi2VO5.5.

  14. The effect of heteroatomic substitutions on the band gap of polyacetylene and polyparaphenylene derivatives

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Sok; Kertesz, Milkos

    1988-02-01

    The electronic structures of polyparaphenylene (PPP), polyacetylene (PA), and their derivatives with small energy gaps have been studied by the Hückel and MNDO crystal orbital methods. The effect of nuclear relaxation and heteroatomic substitution on the energy gaps (Eg) have been taken into account by compelete geometry optimization using periodic boundary conditions as opposed to earlier cluster based calculations. Calculations were done on the following polyacetylene derivatives: polypyrrole (PPy), polythiophene (PT), polyisothianaphthene (PITN), poly (5,5'-bithiophene methenyl) (PBTM, 11, X=S, R=H, m1=m2=1), and poly (5,5'-bipyrrole methenyl) (PBPM, 11, X=NH, R=H, m1=m2=1). Energetics and band gaps for the two isomeric forms, the quinoid and aromatic structures of PPy and PT, are discussed and critically compared with previous calculations. Perturbational molecular orbital theory is invoked to explain the narrower Eg for PITN, PBTM, and PBPM, relative to that of PA. Calculations for PPP derivatives {m-polybenzo[b]thiophene (PBT,5b), polybenzo[b,f]thieno[3,4-c]thiophene (PBTT, 5a, X=S), and polybenzo[b,f]pyrrolo[3,4-c]pyrrole (PBPP, 5a, X=NH)} show that the Eg of some of these polymers is substantially smaller than that of PPP. Comments on ways to stabilize structures with desired small energy gaps are made. A correlation of the Eg with heteroatom perturbation and geometrical relaxation is given. It is found that Eg is controlled not by aromatic vs quinoid contributions, but by the geometrical and heteroatomic effects on the frontier orbitals of the polymer.

  15. Substituted-letter and transposed-letter effects in a masked priming paradigm with French developing readers and dyslexics.

    PubMed

    Lété, Bernard; Fayol, Michel

    2013-01-01

    The aim of the study was to undertake a behavioral investigation of the development of automatic orthographic processing during reading acquisition in French. Following Castles and colleagues' 2007 study (Journal of Experimental Child Psychology, 97, 165-182) and their lexical tuning hypothesis framework, substituted-letter and transposed-letter primes were used in a masked priming paradigm with third graders, fifth graders, adults, and phonological dyslexics matched on reading level with the third graders. No priming effect was found in third graders. In adults, only a transposed-letter priming effect was found; there was no substituted-letter priming effect. Finally, fifth graders and dyslexics showed both substituted-letter and transposed-letter priming effects. Priming effects between the two groups were of the same magnitude after response time (RT) z-score transformation. Taken together, our results show that the pattern of priming effects found by Castles and colleagues in English normal readers emerges later in French normal readers. In other words, language orthographies seem to constrain the tuning of the orthographic system, with an opaque orthography producing faster tuning of orthographic processing than more transparent orthographies because of the high level of reliance on phonological decoding while learning to read.

  16. The Pathologic Effect of a Novel Neomorphic Fgf9Y162C Allele Is Restricted to Decreased Vision and Retarded Lens Growth

    PubMed Central

    Puk, Oliver; Möller, Gabriele; Geerlof, Arie; Krowiorz, Kathrin; Ahmad, Nafees; Wagner, Sibylle; Adamski, Jerzy; de Angelis, Martin Hrabé; Graw, Jochen

    2011-01-01

    Fibroblast growth factor (Fgf) signalling plays a crucial role in many developmental processes. Among the Fgf pathway ligands, Fgf9 (UniProt: P54130) has been demonstrated to participate in maturation of various organs and tissues including skeleton, testes, lung, heart, and eye. Here we establish a novel Fgf9 allele, discovered in a dominant N-ethyl-N-nitrosourea (ENU) screen for eye-size abnormalities using the optical low coherence interferometry technique. The underlying mouse mutant line Aca12 was originally identified because of its significantly reduced lens thickness. Linkage studies located Aca12 to chromosome 14 within a 3.6 Mb spanning interval containing the positional candidate genes Fgf9 (MGI: 104723), Gja3 (MGI: 95714), and Ift88 (MGI: 98715). While no sequence differences were found in Gja3 and Ift88, we identified an A→G missense mutation at cDNA position 770 of the Fgf9 gene leading to an Y162C amino acid exchange. In contrast to previously described Fgf9 mutants, Fgf9Y162C carriers were fully viable and did not reveal reduced body-size, male-to-female sexual reversal or skeletal malformations. The histological analysis of the retina as well as its basic functional characterization by electroretinography (ERG) did not show any abnormality. However, the analysis of head-tracking response of the Fgf9Y162C mutants in a virtual drum indicated a gene-dosage dependent vision loss of almost 50%. The smaller lenses in Fgf9Y162C suggested a role of Fgf9 during lens development. Histological investigations showed that lens growth retardation starts during embryogenesis and continues after birth. Young Fgf9Y162C lenses remained transparent but developed age-related cataracts. Taken together, Fgf9Y162C is a novel neomorphic allele that initiates microphakia and reduced vision without effects on organs and tissues outside the eye. Our data point to a role of Fgf9 signalling in primary and secondary lens fiber cell growth. The results underline the importance

  17. Effect of 5-FU substitution and mutation on Sm protein binding to human U4 snRNA.

    PubMed

    Cui, Wei; Gmeiner, William H

    2002-01-01

    The effects of native and non-native nucleotide substitution on the binding of Sm proteins to human U4 snRNA were investigated to determine if the Sm site was a likely target for the RNA-mediated effects of the anticancer drug 5-FU, and other nucleoside analogues. The Sm binding site of human U4 snRNA was prepared by in vitro transcription, and Sm protein binding was assessed using gel mobility shift assays. The U4:Sm RNA:protein complex was identified by immunoprecipitation with the Sm-specific Y12 antibody. The effects of 5-FU substitution were assessed by including FUTP in the in vitro transcription reactions. The effects of native nucleotide substitution were assessed by mutagenesis. Deletion mutants were used to assess the relative importance of the two stem-loops that flank the Sm binding site for protein binding. Point mutation (U-->G) to the 5'-Urd in the Sm site reduced Sm protein binding while similar point mutation to the 3'-Urd had a lesser effect. Mutation (U-->G) of all Urd in the Sm site completely inhibited Sm protein binding. The central stem-loop contributed significantly to Sm protein complex formation but the 3' stem-loop had little effect. Substitution of Urd by 5-fluorourdine (FUrd) did not inhibit Sm protein binding, but reduced the stability of the resulting complex. The results indicate that 5-FU, or other Uracil analogues, are unlikely to exert RNA-mediated effects through inhibition of Sm protein binding.

  18. Effect of zinc substitution on magnetic and electrical properties of nanocrystalline nickel ferrite synthesized by refluxing method

    NASA Astrophysics Data System (ADS)

    Nandapure, A. I.; Kondawar, S. B.; Sawadh, P. S.; Nandapure, B. I.

    2012-04-01

    Nanocrystalline Nickel ferrite (NiFe2O4) and Zn substituted nickel ferrite (NiZnFe2O4) have been synthesized by the refluxing method. These ferrites were characterized by XRD, TEM, Mossbauer spectroscopy and VSM in order to study the effect of zinc substitution in nickel ferrite. XRD diffraction results confirm the spinel structure for the prepared nanocrystalline ferrites with an average crystallite size of 14-16 nm. Lattice parameter was found to increase with the substitution of Zn2+ ions from 8.40 Å to 8.42 Å. TEM images confirmed average particle size of about 20 nm and indicates nanocrystalline nature of the compounds. A shift in isomeric deviation with the doublet was observed due to the influence of Zn substitution in the nickel ferrite. The Zn content has a significant influence on the magnetic behavior and electrical conductivity of NiFe2O4. Saturation magnetization drastically increased whereas room temperature electrical conductivity decreased due to the addition of Zn content in NiFe2O4, indicating super magnetic material with lesser coercivity.

  19. Effects of hypophysectomy and substitution with growth hormone, prolactin, and thyroxine on growth and deposition in juvenile frogs, Xenopus laevis.

    PubMed

    Nybroe, O; Rosenkilde, P; Ryttersgaard, L

    1985-02-01

    Growth was studied in young metamorphosed frogs, Xenopus laevis, following hypophysectomy and substitution with mammalian growth hormone (bGH or pGH), mammalian prolactin (oPRL), and thyroxine. Hypophysectomy reduced growth (weight and length increase). GH and PRL proved equally efficient in restoring growth and in mobilizing energy stores (fat bodies and liver glycogen). No synergistic effects between GH and PRL could be observed. GH exerted its growth-promoting effects by increasing gross food conversion efficiency (weight increase/food intake), but did not stimulate appetite. Moderate GH doses given to a group of frogs in growth stagnation exerted moderate metabolic effects, and may have stimulated appetite in some animals, but did not increase body size significantly. Thyroxine was unable to promote growth, but increased mobilization of energy stores. Hypophysectomy and hormone substitution affected feeding behavior. The nature of the actions of pituitary somatotropic hormones and of thyroxine on growth and deposition is discussed.

  20. Combined effects of transition metal (Ni and Rh) substitution and annealing/quenching on the physical properties of CaFe2As2

    SciTech Connect

    Ran, S; Bud'ko, S L; Straszheim, W E; Canfield, P C

    2014-08-01

    We performed systematic studies of the combined effects of annealing/quenching temperature (TA/Q) and T=Ni, Rh substitution (x) on the physical properties of Ca(Fe1-xTx)2As2. We constructed two-dimensional, TA/Q-x phase diagrams for the low-temperature states for both substitutions to map out the relations between ground states and compared them with that of Co substitution. Ni substitution, which brings one more extra electron per substituted atom and suppresses the c-lattice parameter at roughly the same rate as Co substitution, leads to a similar parameter range of antiferromagnetic/orthorhombic phase space in the TA/Q-x space as that found for Co substitution, but the parameter range for superconductivity has been shrunk (roughly by a factor of 2). This result is similar to what is found when Co- and Ni-substituted BaFe2As2 are compared. On the other hand, Rh substitution, which brings the same amount of extra electrons as does Co substitution, but suppresses the c-lattice parameter more rapidly, has a different phase diagram. The collapsed tetragonal phase exists much more pervasively, to the exclusion of the normal, paramagnetic, tetragonal phase. The range of antiferromagnetic/orthorhombic phase space is noticeably reduced, and the superconducting region is substantially suppressed, essentially truncated by the collapsed tetragonal phase. In addition, we found that whereas for Co substitution there was no difference between phase diagrams for samples annealed for 1 or 7 days, for Ni and Rh substitutions a second, reversible effect of annealing was revealed by 7-day anneals.

  1. Aod1 controlling day 3 thymectomy-induced autoimmune ovarian dysgenesis in mice encompasses two linked quantitative trait loci with opposing allelic effects on disease susceptibility.

    PubMed

    Roper, Randall J; McAllister, Ryan D; Biggins, Julia E; Michael, Sandra D; Min, Soo Hong; Tung, Kenneth S K; Call, Stanford B; Gao, Jianfeng; Teuscher, Cory

    2003-06-15

    Day 3 thymectomy (D3Tx) leads to a paucity of CD4(+)CD25(+) suppressor T cells, a loss of peripheral tolerance, and the development of organ-specific autoimmune disease in adult mice. Importantly, D3Tx does not lead to autoimmune disease in all mouse strains, indicating that this process is genetically controlled. Previously, we reported linkage of D3Tx-induced autoimmune ovarian dysgenesis (AOD) and its intermediate phenotypes, antiovarian autoantibody responsiveness, oophoritis, and atrophy, to five quantitative trait loci (QTL), designated Aod1 through Aod5. We also showed interaction between these QTL and H2 as well as Gasa2, a QTL controlling susceptibility to D3Tx-induced autoimmune gastritis. To physically map Aod1, interval-specific bidirectional recombinant congenic strains of mice were generated and studied for susceptibility to D3Tx-induced AOD. Congenic mapping studies revealed that Aod1 controls susceptibility to oophoritis and comprises two linked QTL with opposing allelic effects. Aod1a resides between D16Mit211 (23.3 cM) and D16Mit51 (66.75 cM) on chromosome 16. Aod1b maps proximal of Aod1a between D16Mit89 (20.9 cM) and D16Mit211 (23.3 cM) and includes the candidate genes stefin A1, A2, and A3 (Stfa1-Stfa3), inhibitors of cathepsin S, a cysteine protease required for autoantigen presentation, and the development of autoimmune disease of the salivary and lacrimal glands following D3Tx. cDNA sequencing revealed the existence of structural polymorphisms for both Stfa1 and Stfa2. Given the roles of cathepsins in Ag processing and presentation, Stfa1 and Stfa2 alleles have the potential to control susceptibility to autoimmune disease at the level of both CD4(+)CD25(+) suppressor and CD4(+)CD25(-) effector T cells.

  2. MC1R variant allele effects on UVR-induced phosphorylation of p38, p53, and DDB2 repair protein responses in melanocytic cells in culture.

    PubMed

    Wong, Shu Shyan; Ainger, Stephen A; Leonard, J Helen; Sturm, Richard A

    2012-05-01

    Variant alleles of the human melanocortin 1 receptor (MC1R) reduce the ability of melanocytes to produce the dark pigment eumelanin, with R alleles being most deficient. Cultured melanocytes of MC1R R/R variant genotype give reduced responses to [Nle(4), D-Phe(7)]α-melanocyte-stimulating hormone (NDP-MSH) ligand stimulation and lower levels of DNA repair than MC1R wild-type strains. p38 controls xeroderma pigmentosum (XP)-C recruitment to DNA damage sites through regulating ubiquitylation of the DNA damage-binding protein 2 (DDB2) protein, and p53 is implicated in the nuclear excision repair process through its regulation of XP-C and DDB2 protein expression. We report the effects of MC1R ligand treatment and UVR exposure on phosphorylation of p38 and p53, and DDB2 protein expression in MC1R variant strains. Wild-type MC1R melanocyte strains grown together with keratinocytes in coculture, when treated with NDP-MSH and exposed to UVR, gave synergistic activation of p38 and p53 phosphorylation, and were not replicated by R/R variant melanocytes, which have lower basal levels of phosphorylated forms of p38. Minor increases in p38 phosphorylation status in R/R variant melanocyte cocultures could be attributed to the keratinocytes alone. We also found that MC1R wild-type strains regulate DDB2 protein levels through p38, but MC1R R/R variant melanocytes do not. This work confirms the important functional role that the MC1R receptor plays in UVR stress-induced DNA repair.

  3. Use of allele scores as instrumental variables for Mendelian randomization

    PubMed Central

    Burgess, Stephen; Thompson, Simon G

    2013-01-01

    Background An allele score is a single variable summarizing multiple genetic variants associated with a risk factor. It is calculated as the total number of risk factor-increasing alleles for an individual (unweighted score), or the sum of weights for each allele corresponding to estimated genetic effect sizes (weighted score). An allele score can be used in a Mendelian randomization analysis to estimate the causal effect of the risk factor on an outcome. Methods Data were simulated to investigate the use of allele scores in Mendelian randomization where conventional instrumental variable techniques using multiple genetic variants demonstrate ‘weak instrument’ bias. The robustness of estimates using the allele score to misspecification (for example non-linearity, effect modification) and to violations of the instrumental variable assumptions was assessed. Results Causal estimates using a correctly specified allele score were unbiased with appropriate coverage levels. The estimates were generally robust to misspecification of the allele score, but not to instrumental variable violations, even if the majority of variants in the allele score were valid instruments. Using a weighted rather than an unweighted allele score increased power, but the increase was small when genetic variants had similar effect sizes. Naive use of the data under analysis to choose which variants to include in an allele score, or for deriving weights, resulted in substantial biases. Conclusions Allele scores enable valid causal estimates with large numbers of genetic variants. The stringency of criteria for genetic variants in Mendelian randomization should be maintained for all variants in an allele score. PMID:24062299

  4. Deleterious alleles in the human genome are on average younger than neutral alleles of the same frequency.

    PubMed

    Kiezun, Adam; Pulit, Sara L; Francioli, Laurent C; van Dijk, Freerk; Swertz, Morris; Boomsma, Dorret I; van Duijn, Cornelia M; Slagboom, P Eline; van Ommen, G J B; Wijmenga, Cisca; de Bakker, Paul I W; Sunyaev, Shamil R

    2013-01-01

    Large-scale population sequencing studies provide a complete picture of human genetic variation within the studied populations. A key challenge is to identify, among the myriad alleles, those variants that have an effect on molecular function, phenotypes, and reproductive fitness. Most non-neutral variation consists of deleterious alleles segregating at low population frequency due to incessant mutation. To date, studies characterizing selection against deleterious alleles have been based on allele frequency (testing for a relative excess of rare alleles) or ratio of polymorphism to divergence (testing for a relative increase in the number of polymorphic alleles). Here, starting from Maruyama's theoretical prediction (Maruyama T (1974), Am J Hum Genet USA 6:669-673) that a (slightly) deleterious allele is, on average, younger than a neutral allele segregating at the same frequency, we devised an approach to characterize selection based on allelic age. Unlike existing methods, it compares sets of neutral and deleterious sequence variants at the same allele frequency. When applied to human sequence data from the Genome of the Netherlands Project, our approach distinguishes low-frequency coding non-synonymous variants from synonymous and non-coding variants at the same allele frequency and discriminates between sets of variants independently predicted to be benign or damaging for protein structure and function. The results confirm the abundance of slightly deleterious coding variation in humans.

  5. Effect of Non-substitutional Hole Doping on the Tc of MgB2

    NASA Astrophysics Data System (ADS)

    Ma, Danhao; Adu, Kofi; Sumanasekera, Gamini; Hess, Dustin; Terrones, Mauricio

    2015-03-01

    We report, for the first time, an increase in the superconducting critical temperature, TC of MgB2 by a nonsubstitutional hole-doping of the MgB2 structure using minute, single-wall carbon nanotube (SWCNT) inclusions. We varied the SWCNT concentration from 0.05wt% to 5wt% and investigated the temperature-dependent resistivity and TEP from 5K to 300K. We used micro-Raman spectroscopy, field-emission scanning electron microscopy, and x-ray diffraction to analyze the interfacial interactions between the SWCNTs and the MgB2 grains. We obtained an increase in TC from 33.0 to 37.8K (ΔT = 4.8K) which is attributed to charge transfer from the MgB2 structure to the SWCNT structure. The charge transfer phenomenon is confirmed by micro-Raman analysis of the phonon states of the SWCNT tangential band frequency in the composites. We determined the charge transfer per carbon atom to be 0.0023/C, 0.0018/C and 0.0008/C for 0.05wt%, 0.5wt% and 5wt% SWCNT inclusions, respectively, taking into account the contributions from the softening of the lattice constant and the nonadiabatic (dynamic) effects at the Fermi level. This report provides an experimental, alternative pathway to hole-doping of MgB2 without appealing to chemical substitution. This Work is Supported by Penn State Altoona Undergraduate Research Sponsored Program and Penn State Materials Research Institute, University Park.

  6. Polarization Effects for Hydrogen-Bonded Complexes of Substituted Phenols with Water and Chloride Ion.

    PubMed

    Jorgensen, William L; Jensen, Kasper P; Alexandrova, Anastassia N

    2007-11-01

    Variations in hydrogen-bond strengths are investigated for complexes of nine para-substituted phenols (XPhOH) with a water molecule and chloride ion. Results from ab initio HF/6-311+G(d, p) and MP2/6-311+G(d, p)//HF/6-311+G(d, p) calculations are compared with those from the OPLS-AA and OPLS/CM1A force fields. In the OPLS-AA model, the partial charges on the hydroxyl group of phenol are not affected by the choice of para substituent, while the use of CM1A charges in the OPLS/CM1A approach does provide charge redistribution. The ab initio calculations reveal a 2.0-kcal/mol range in hydrogen-bond strengths for the XPhOH⋯OH(2) complexes in the order X = NO(2) > CN > CF(3) > Cl > F > H >OH >CH(3) > NH(2). The pattern is not well-reproduced with OPLS-AA, which also compresses the variation to 0.7 kcal/mol. However, the OPLS/CM1A results are in good accord with the ab initio findings for both the ordering and range, 2.3 kcal/mol. The hydrogen bonding is, of course, weaker with XPhOH as acceptor, the order for X is largely inverted, and the range is reduced to ca. 1.0 kcal/mol. The substituent effects are found to be much greater for the chloride ion complexes with a range of 11 kcal/mol. For quantitative treatment of such strong ion-molecule interactions the need for fully polarizable force fields is demonstrated.

  7. Effect of neodymium substitution on structural and ferroelectric properties of BNT ceramics

    SciTech Connect

    Pal, Vijayeta; Dwivedi, R.K.; Thakur, O.P.

    2014-03-01

    Graphical abstract: - Highlights: • First time, we synthesized (Bi{sub 1−x}Nd{sub x}){sub 0.5}Na{sub 0.5}TiO{sub 3} system by semi wet technique. • Grain size reduced with doping and Nd acts as an inhibitor in the grain growth. • Specimen with x = 0.02 exhibits excellent ferroelectric properties at RT. • P–E loops show the co-existence of polar and non polar regions around ‘T{sub d}’. - Abstract: Polycrystalline specimens of (Bi{sub 1−x}Nd{sub x}){sub 0.5}Na{sub 0.5}TiO{sub 3} (BNNT) ceramic system with compositions x ≤ 0.04 were synthesized by semi-wet technique using ethylene glycol precursor. Structural and electrical properties were investigated in detail to observe the effect of neodymium (Nd) substitution in BNT system. XRD patterns for all the specimens showed single phase formation with rhombohedral structure. Field emission scanning electron micrographs (FE-SEM) revealed that the grain growth was inhibited significantly with Nd content. The temperature dependence behaviour of dielectric constant revealed that the depolarisation temperature ‘T{sub d}’ decreases whereas temperature of maximum dielectric constant ‘T{sub m}’ increases with Nd concentration. The piezoelectric charge coefficient (d{sub 33}) showed maxima at x = 0.02 and well defined ferroelectric behaviour was observed for all the samples.

  8. Saliva substitutes in combination with highly concentrated fluorides and brushing: in vitro effects on enamel subsurface lesions.

    PubMed

    Tschoppe, P; Siegel, A; Meyer-Lueckel, H

    2010-01-01

    Hyposalivation is often associated with high caries activity, in particular in patients undergoing irradiation in the head/neck area. Besides the use of saliva substitutes to relieve the oral symptoms, daily application of fluoride gels or toothpaste (5,000 μg F⁻/g) is recommended for caries prevention. The aim of this study was to evaluate potentially remineralising effects of these fluoride agents in combination with saliva substitutes on enamel subsurface lesions. Demineralised bovine specimens were either stored in mineral water [control; saturation with respect to octacalcium phosphate (S(OCP)): 0.8], a demineralising saliva substitute (Glandosane; S(OCP): 0.3) or in a modified (with respect to S(OCP)) saliva substitute [Saliva natura (SN); S(OCP): 1.9] for 5 weeks (37°C). The following treatments were applied twice daily (11-13/group): no treatment (0), ProSchmelz fluoride gel (PS; 10 min application), Duraphat toothpaste (DP; 10 s; brushing with toothpaste/storage solution slurry), combination of DP+PS. Mineral parameters before/after storage were evaluated from microradiographs. Storage in Glandosane led to significant demineralisation (p < 0.05; paired t test), whereas additional use of fluoride agents neutralised the demineralising effect (p > 0.05). Storage in water alone resulted in no changes in mineral parameters (p > 0.05), whereas in combination with fluorides remineralisation could be shown (p < 0.05). For SN alone, remineralisation was observed (p < 0.05), but no additional beneficial effects of fluorides were detected. Under the conditions chosen, the fluoride agents reduce the demineralising effects of Glandosane and promote the remineralisation of specimens stored in water. Remineralising effects of SN could not be enhanced by the fluorides.

  9. Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns

    PubMed Central

    Kulshrestha, Aman; Schomaker, Jennifer M.; Holmes, Daniel; Staples, Richard J.; Jackson, James E.; Borhan, Babak

    2014-01-01

    Good to excellent stereo-selectivity has been found in the addition reactions of Grignard and organo-zinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycar-bonyl-protected trans, and tosyl-pro-tected 2,3-disubstituted aziridine-2-car-boxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziri-dines’ substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6–31G* level of theory with the SM8 solvation model to account for solvent effects. PMID:21928447

  10. Detection of 549 new HLA alleles in potential stem cell donors from the United States, Poland and Germany.

    PubMed

    Hernández-Frederick, C J; Cereb, N; Giani, A S; Ruppel, J; Maraszek, A; Pingel, J; Sauter, J; Schmidt, A H; Yang, S Y

    2016-01-01

    We characterized 549 new human leukocyte antigen (HLA) class I and class II alleles found in newly registered stem cell donors as a result of high-throughput HLA typing. New alleles include 101 HLA-A, 132 HLA-B, 105 HLA-C, 2 HLA-DRB1, 89 HLA-DQB1 and 120 HLA-DPB1 alleles. Mainly, new alleles comprised single nucleotide variations when compared with homologous sequences. We identified nonsynonymous nucleotide mutations in 70.7% of all new alleles, synonymous variations in 26.4% and nonsense substitutions in 2.9% (null alleles). Some new alleles (55, 10.0%) were found multiple times, HLA-DPB1 alleles being the most frequent among these. Furthermore, as several new alleles were identified in individuals from ethnic minority groups, the relevance of recruiting donors belonging to such groups and the importance of ethnicity data collection in donor centers and registries is highlighted.

  11. Effects of Sb Substitution by Sn on the Thermoelectric Properties of ZrCoSb

    NASA Astrophysics Data System (ADS)

    Yuan, Bo; Wang, Bo; Huang, Lihong; Lei, Xiaobo; Zhao, Lidong; Wang, Chao; Zhang, Qinyong

    2016-12-01

    ZrCoSb1-x Sn x (x = 0, 0.1, 0.2, 0.3, 0.35) half-Heusler (HH) samples were prepared by arc melting, ball milling and then hot-pressing. X-ray diffraction analysis results showed that all samples were crystallized in a HH phase. Thermoelectric (TE) properties of ZrCoSb1-x Sn x were measured from room temperature (RT) to 973 K. The Seebeck coefficient changed from negative to positive after substituting Sb with Sn, indicating the occurrence of conduction type transformation in ZrCoSb-based HH compounds. At the same time, the Seebeck coefficient decreased with increasing Sn substitution, and the electrical conductivity increased obviously with Sn addition when x ≤ 0.3. The lattice thermal conductivity of Sn-substituted samples was reduced dramatically because of the stronger phonon scattering by the strain field fluctuation induced by Sn replacement of Sb. Finally, as a result of the Sn substitution, a peak ZT of 0.52 was reached at 973 K in the ZrCoSb0.7Sn0.3 sample.

  12. Spatial disorientation in Parkinson's disease: no effect of levodopa substitution therapy.

    PubMed

    Hovestadt, A; De Jong, G J; Meerwaldt, J D

    1988-11-01

    In 22 patients with idiopathic Parkinson's disease, we tested spatial orientation with the rod orientation test, before and after levodopa substitution therapy was started. In both situations an impairment of spatial orientation could be demonstrated: levodopa did not improve this impairment.

  13. Space can substitute for time in predicting climate-change effects on biodiversity

    USGS Publications Warehouse

    Blois, Jessica L.; Williams, John W.; Fitzpatrick, Matthew C.; Jackson, Stephen T.; Ferrier, Simon

    2013-01-01

    “Space-for-time” substitution is widely used in biodiversity modeling to infer past or future trajectories of ecological systems from contemporary spatial patterns. However, the foundational assumption—that drivers of spatial gradients of species composition also drive temporal changes in diversity—rarely is tested. Here, we empirically test the space-for-time assumption by constructing orthogonal datasets of compositional turnover of plant taxa and climatic dissimilarity through time and across space from Late Quaternary pollen records in eastern North America, then modeling climate-driven compositional turnover. Predictions relying on space-for-time substitution were ∼72% as accurate as “time-for-time” predictions. However, space-for-time substitution performed poorly during the Holocene when temporal variation in climate was small relative to spatial variation and required subsampling to match the extent of spatial and temporal climatic gradients. Despite this caution, our results generally support the judicious use of space-for-time substitution in modeling community responses to climate change.

  14. Theoretical study of substitution effects on molecular reorganization energy in organic semiconductors.

    PubMed

    Geng, Hua; Niu, Yingli; Peng, Qian; Shuai, Zhigang; Coropceanu, Veaceslav; Brédas, Jean-Luc

    2011-09-14

    Chemical substitutions are powerful molecular design tools to enhance the performance of organic semiconductors, for instance, to improve solubility, intermolecular stacking, or film quality. However, at the microscopic level, substitutions in general tend to increase the molecular reorganization energy and thus decrease the intrinsic charge-carrier mobility. Through density functional theory calculations, we elucidate strategies that could be followed to reduce the reorganization energy upon chemical substitution. Specific examples are given here for hole-transport materials including indolo-carbazoles and several triarylamine derivatives. Through decomposition of the total reorganization energy into the internal coordinate space, we are able to identify the molecular segment that provides the most important contributions to the reorganization energy. It is found that when substitution reduces (enhances) the amplitude of the relevant frontier molecular orbital in that segment, the total reorganization energy decreases (increases). In particular, chlorination at appropriate positions can significantly reduce the reorganization energy. Several other substituents are shown to play a similar role, to a greater or lesser extent.

  15. Space can substitute for time in predicting climate-change effects on biodiversity.

    PubMed

    Blois, Jessica L; Williams, John W; Fitzpatrick, Matthew C; Jackson, Stephen T; Ferrier, Simon

    2013-06-04

    "Space-for-time" substitution is widely used in biodiversity modeling to infer past or future trajectories of ecological systems from contemporary spatial patterns. However, the foundational assumption--that drivers of spatial gradients of species composition also drive temporal changes in diversity--rarely is tested. Here, we empirically test the space-for-time assumption by constructing orthogonal datasets of compositional turnover of plant taxa and climatic dissimilarity through time and across space from Late Quaternary pollen records in eastern North America, then modeling climate-driven compositional turnover. Predictions relying on space-for-time substitution were ∼72% as accurate as "time-for-time" predictions. However, space-for-time substitution performed poorly during the Holocene when temporal variation in climate was small relative to spatial variation and required subsampling to match the extent of spatial and temporal climatic gradients. Despite this caution, our results generally support the judicious use of space-for-time substitution in modeling community responses to climate change.

  16. Dairy Cattle Breeding Effectiveness Analysis under the Conditions of Import Substitution

    ERIC Educational Resources Information Center

    Tokarev, Yuri A.; Merkushova, Nina I.; Bakanach, Olga V.; Proskurina, Natalya V.; Sazhina, Natalia S.

    2016-01-01

    The relevance of the research problem is inspired by the strategic importance of dairy farming to the national economy, which is especially evident in the context of the EU economic sanctions against the Russian Federation and carrying out the import substitution policy. First and foremost, this policy applies to food commodities, including milk.…

  17. Space can substitute for time in predicting climate-change effects on biodiversity

    NASA Astrophysics Data System (ADS)

    Blois, Jessica L.; Williams, John W.; Fitzpatrick, Matthew C.; Jackson, Stephen T.; Ferrier, Simon

    2013-06-01

    "Space-for-time" substitution is widely used in biodiversity modeling to infer past or future trajectories of ecological systems from contemporary spatial patterns. However, the foundational assumption-that drivers of spatial gradients of species composition also drive temporal changes in diversity-rarely is tested. Here, we empirically test the space-for-time assumption by constructing orthogonal datasets of compositional turnover of plant taxa and climatic dissimilarity through time and across space from Late Quaternary pollen records in eastern North America, then modeling climate-driven compositional turnover. Predictions relying on space-for-time substitution were ∼72% as accurate as "time-for-time" predictions. However, space-for-time substitution performed poorly during the Holocene when temporal variation in climate was small relative to spatial variation and required subsampling to match the extent of spatial and temporal climatic gradients. Despite this caution, our results generally support the judicious use of space-for-time substitution in modeling community responses to climate change.

  18. Synthesis of sterically hindered ortho-substituted tetraphenylethenes. Electronic effects in the McMurry olefination reaction.

    PubMed

    Chung, Mee-Kyung; Qi, Guizhong; Stryker, Jeffrey M

    2006-03-30

    [reaction: see text] Contrary to literature consensus, the McMurry olefination reaction can be extended to the direct synthesis of sterically encumbered tetrakis(2-substituted) tetraphenylethenes from the corresponding 2,2'-disubstituted benzophenones. The reaction exploits previously unrecognized substrate-based electronic effects that dominate over otherwise controlling steric considerations and provides highly efficient access to derivatives of tetrakis(2-hydroxyphenyl)ethene, a novel preorganized ligand system for polymetallic coordination chemistry and catalysis.

  19. Microheterogeneity of antithrombin III: effect of single amino acid substitutions and relationship with functional abnormalities.

    PubMed

    De Stefano, V; Leone, G; Mastrangelo, S; Lane, D A; Girolami, A; de Moerloose, P; Sas, G; Abildgaard, U; Blajchman, M; Rodeghiero, F

    1994-02-01

    Microheterogeneity of antithrombin III (AT-III) was investigated by crossed immunoelectrofocusing (CIEF) on eleven molecular variants. A normal pattern was found in five variants while two different abnormal CIEF patterns were found in the other four and two variants, respectively. Point mutations causing a major pI change (exceeding 4.0) of the amino acid substituted lead to alterations in the overall microheterogeneity. The variants thus substituted share a first type of abnormal CIEF pattern with alterations throughout the pH range, regardless of the location of the mutation (reactive site and adjacent regions or heparin binding region). Minor amino acid pI changes in these regions do not alter the AT-III overall microheterogeneity, whatever the resulting functional defect. However, if the mutation is placed in the region around positions 404 or 429, then even minor changes of the amino acid pI seem able to alter the overall charge, leading to a second type of abnormal CIEF pattern with the main alteration at pH 4.8-4.6. Neuraminidase treatment leads to disappearance of microheterogeneity except for the variants with the Arg393 to Cys substitution. Addition of thrombin induces CIEF modifications specifically related to the functional defect. A normal formation of thrombin-antithrombin complexes induces a shift towards the more acid pH range, whereas in the variants substituted at the reactive site the CIEF pattern is substantially unaffected by thrombin; variants substituted at positions 382-384 show a maximal thrombin-induced increase of the isoforms at pI 4.8-4.6. Therefore mutant antithrombins with different functional abnormalities but sharing a common CIEF pattern were well distinguished.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Oxygen substitution effects in Li10GeP2S12 solid electrolyte

    NASA Astrophysics Data System (ADS)

    Sun, Yulong; Suzuki, Kota; Hara, Kosuke; Hori, Satoshi; Yano, Taka-aki; Hara, Masahiko; Hirayama, Masaaki; Kanno, Ryoji

    2016-08-01

    For the lithium super-ionic conductor Li10GeP2S12, the partial substitution of sulfur by oxygen is achieved via a solid-state reaction. The solid-solution range of oxygen is found to be 0 ≤ x < 0.9 in Li10GeP2S12-xOx. Structure refinements using synchrotron X-ray diffraction data confirm the preference for oxygen substitution in the PS4 tetrahedra. The local structural change in the P(S/O)4 tetrahedra upon substitution is also indicated by Raman spectroscopy. Ionic conduction properties are maintained even after the oxygen substitution in Li10GeP2S12; the ionic conductivity of Li10GeP2S12-xOx (0.3 ≤ x ≤ 0.6) ranges from 1.03 × 10-2 to 8.43 × 10-3 S cm-1 at 298 K. No redox current is observed by cyclic voltammetry from nearly 0 to 10 V versus Li/Li+ except for that due to the lithium deposition/dissolution reactions. All-solid-state batteries using Li10GeP2S12-xOx (x = 0.3 and 0.6) as solid electrolytes with Li metal anodes show discharge capacities exceeding 100 mAh g-1 and better cycling performance compared to batteries using the original Li10GeP2S12. The partial substitution of oxygen for sulfur in Li10GeP2S12 affords a novel solid electrolyte, Li10GeP2S12-xOx, with high conductive properties and electrochemical stability.

  1. Update on allele nomenclature for human cytochromes P450 and the Human Cytochrome P450 Allele (CYP-allele) Nomenclature Database.

    PubMed

    Sim, Sarah C; Ingelman-Sundberg, Magnus

    2013-01-01

    Interindividual variability in xenobiotic metabolism and drug response is extensive and genetic factors play an important role in this variation. A majority of clinically used drugs are substrates for the cytochrome P450 (CYP) enzyme system and interindividual variability in expression and function of these enzymes is a major factor for explaining individual susceptibility for adverse drug reactions and drug response. Because of the existence of many polymorphic CYP genes, for many of which the number of allelic variants is continually increasing, a universal and official nomenclature system is important. Since 1999, all functionally relevant polymorphic CYP alleles are named and published on the Human Cytochrome P450 Allele (CYP-allele) Nomenclature Web site (http://www.cypalleles.ki.se). Currently, the database covers nomenclature of more than 660 alleles in a total of 30 genes that includes 29 CYPs as well as the cytochrome P450 oxidoreductase (POR) gene. On the CYP-allele Web site, each gene has its own Webpage, which lists the alleles with their nucleotide changes, their functional consequences, and links to publications identifying or characterizing the alleles. CYP2D6, CYP2C9, CYP2C19, and CYP3A4 are the most important CYPs in terms of drug metabolism, which is also reflected in their corresponding highest number of Webpage hits at the CYP-allele Web site.The main advantage of the CYP-allele database is that it offers a rapid online publication of CYP-alleles and their effects and provides an overview of peer-reviewed data to the scientific community. Here, we provide an update of the CYP-allele database and the associated nomenclature.

  2. Influence of sodium substitutes on 5-HT-mediated effects at mouse 5-HT3 receptors

    PubMed Central

    Barann, M; Schmidt, K; Göthert, M; Urban, B W; Bönisch, H

    2004-01-01

    The influence of sodium ion substitutes on the 5-hydroxytryptamine (5-HT)-induced flux of the organic cation [14C]guanidinium through the ion channel of the mouse 5-HT3 receptor and on the competition of 5-HT with the selective 5-HT3 receptor antagonist [3H]GR 65630 was studied, unless stated otherwise, in mouse neuroblastoma N1E-115 cells. Under physiological conditions (135 mM sodium), 5-HT induced a concentration-dependent [14C]guanidinium influx with an EC50 (1.3 μM) similar to that in electrophysiological studies. The stepwise replacement of sodium by increasing concentrations of the organic cation hydroxyethyl trimethylammonium (choline) concentration dependently caused both a rightward shift of the 5-HT concentration–response curve and an increase in the maximum effect of 5-HT. Complete replacement of sodium resulted in a 34-fold lower potency of 5-HT and an almost two times higher maximal response. A low potency of 5-HT in choline buffer was also observed in other 5-HT3 receptor-expressing rodent cell lines (NG 108-15 or NCB 20). Replacement of Na+ by Li+ left the potency and maximal effects of 5-HT almost unchanged. Replacement by tris (hydroxymethyl) methylamine (Tris), tetramethylammonium (TMA) or N-methyl-D-glucamine (NMDG) caused an increase in maximal response to 5-HT similar to that caused by choline. The potency of 5-HT was only slightly reduced by Tris, to a high degree decreased by TMA (comparable to the decrease by choline), but not influenced by NMDG. The potency of 5-HT in inhibiting [3H]GR65630 binding to intact cells was 35-fold lower when sodium was completely replaced by choline, but remained unchanged after replacement by NMDG. The results are compatible with the suggestion that choline competes with 5-HT for the 5-HT3 receptor; the increase in maximal response may be partly due to a choline-mediated delay of the 5-HT-induced desensitization. For studies of 5-HT-evoked [14C]guanidinium flux through 5-HT3 receptor channels, NMDG appears

  3. Allelic variation in developmental genes and effects on winter wheat heading date in the U.S. Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heading date in wheat (Triticum aestivum L.) and other small grain cereals is affected by the vernalization and photoperiod pathways. The reduced-height loci also have an effect on growth and development. Heading date was evaluated in a population of 299 hard winter wheat entries representative of t...

  4. Effect of Na substitution on electronic and optical properties of CuInS{sub 2} chalcopyrite semiconductor

    SciTech Connect

    Mishra, S.; Ganguli, B.

    2015-12-15

    Electronic & optical properties of Na substituted CuNaIn{sub 2}S{sub 4} chalcopyrite semiconductors are significantly modified due to Na substitution in the Cu deficient CuInS{sub 2} semiconductor. These properties are obtained form first principle calculation using density functional theory based tight binding Linear muffin tin orbital method. The presence of Na alters the structural distortion and enhances strengths of Cu d and S p hybridization in CuNaIn{sub 2}S{sub 4}. This effect reduces band gap, in agreement with experimental observations and modify other properties significantly. Calculations of optical matrix elements (OME) and joint density of states (JDOS) show that effects of Na substitution on optical properties come through p–d hybridization and structural distortion. OME contribution is prominent near band edge. Both systems show anisotropic optical properties. - Graphical abstract: The figure shows the band structure and total density of states of CuNaIn{sub 2}S{sub 4}. It illustrates energy bands at various symmetry points, band gap and contribution of various orbitals.

  5. Effect of Ni-site substitutions in superconducting La3Ni2B2N3-δ

    NASA Astrophysics Data System (ADS)

    Michor, H.; Hilscher, G.; Krendelsberger, R.; Rogl, P.; Bourée, F.

    1998-12-01

    We investigated the effect of Ni/Co and Ni/Cu substitutions upon the superconducting and normal state properties of La3(Ni1-xMx)2B2N3-δ (M=Co, Cu). X-ray and neutron diffraction studies reveal a limited solid solubility for Cu: (0substitution only the initial depression rate, dTc/dx~=-0.23 K/(mol % Cu), could be determined. The results clearly show that the suppression of superconductivity is primarily caused by the reduction of N(Ef) concomitant with a fall of the coupling strength λ, while there are no hints for other effects like magnetic pair breaking. The comparison with the results reported for Y(Ni1-xCox)2B2C shows that the electronic changes induced by Ni/Co substitution are very similar in both systems.

  6. Mutational analysis of the BPTI folding pathway: I. Effects of aromatic-->leucine substitutions on the distribution of folding intermediates.

    PubMed Central

    Zhang, J. X.; Goldenberg, D. P.

    1997-01-01

    The roles of aromatic residues in determining the folding pathway of bovine pancreatic trypsin inhibitor (BPTI) were analyzed mutationally by examining the distribution of disulfide-bonded intermediates that accumulated during the refolding of protein variants in which tyrosine or phenylalanine residues were individually replaced with leucine. The eight substitutions examined all caused significant changes in the intermediate distribution. In some cases, the major effect was to decrease the accumulation of intermediates containing two of the three disulfides found in the native protein, without affecting the distribution of earlier intermediates. Other substitutions, however, led to much more random distributions of the intermediates containing only one disulfide. These results indicate that the individual residues making up the hydrophobic core of the native protein make clearly distinguishable contributions to conformation and stability early in folding: The early distribution of intermediates does not appear to be determined by a general hydrophobic collapse. The effects of the substitutions were generally consistent with the structures of the major intermediates determined by NMR studies of analogs, confirming that the distribution of disulfide-bonded species is determined by stabilizing interactions within the ordered regions of the intermediates. The plasticity of the BPTI folding pathway implied by these results can be described using conformational funnels to illustrate the degree to which conformational entropy is lost at different stages in the folding of the wild-type and mutant proteins. PMID:9232656

  7. Effects of 7-O Substitutions on Estrogenic and Antiestrogenic Activities of Daidzein Analogues in MCF-7 Breast Cancer Cells

    PubMed Central

    Jiang, Quan; Payton-Stewart, Florastina; Elliott, Steven; Driver, Jennifer; Rhodes, Lyndsay V.; Zhang, Qiang; Zheng, Shilong; Bhatnagar, Deepak; Boue, Stephen M.; Collins-Burow, Bridgette M.; Sridhar, Jayalakshmi; Stevens, Cheryl; McLachlan, John A.; Wiese, Thomas E.; Burow, Matthew E.; Wang, Guangdi

    2010-01-01

    Daidzein (1) is a natural estrogenic isoflavone. We report here that 1 can be transformed into antiestrogenic ligands by simple alkyl substitutions of the 7-hydroxyl hydrogen. To test the effect of such structural modifications on the hormonal activities of the resulting compounds, a series of daidzein analogues have been designed and synthesized. When MCF-7 cells were treated with the analogues, those resulting from hydrogen substitution by isopropyl (3d), isobutyl (3f), cyclopentyl (3g), and pyrano- (2), inhibited cell proliferation, estrogen-induced transcriptional activity, and estrogen receptor (ER) regulated progesterone receptor (PgR) gene expression. However, methyl (3a) and ethyl (3b) substitutions of the hydroxyl proton only led to moderate reduction of the estrogenic activities. These results demonstrated the structural requirements for the transformation of daidzein from an ER agonist to an antagonist. The most effective analogue, 2 was found to reduce in vivo estrogen stimulated MCF-7 cell tumorigenesis using a xenograft mouse model. PMID:20669983

  8. Effect of Cu and Zn Substitutions on MnSb Properties

    SciTech Connect

    Mitsiuk, V. I.; Ryzhkovskii, V. M.; Tkachenka, T. M.

    2008-10-28

    The NiAs-type solid solutions based on manganese antimonide Mn{sub 1.1}Sb with Zn or Cu (up to 10 at % of substituting component) have been studied by {sup 57}Fe Moessbauer spectroscopy. It has been shown that the replacement of the manganese antimonide by Cu or Zn does not appreciably affect the main Moessbauer parameters in comparison to those of the parent compound. Two different values of hyperfine magnetic field at Fe are present in all the samples and can be attributed to the metal atoms located in MeI and MeII positions. The substitution of Cu or Zn for manganese antimonide leads to the redistribution of the metal atoms between two cation sublattices.

  9. Solvent substitution

    SciTech Connect

    Not Available

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  10. Ab initio study of MgH2: Destabilizing effects of selective substitutions by transition metals

    NASA Astrophysics Data System (ADS)

    Al Alam, Adel F.; Matar, Samir F.; Ouaini, Naïm

    2014-10-01

    The strong ionicity of H within rutile MgH2 is reduced by selective substitution of Mg by T (=Fe, Co, Ni, Pd, Pt) using trirutile super-structure host TMg2H6. These novel model systems, as computed in the quantum mechanical framework of density functional theory, showed a gradual decrease of the charges carried by H down to -0.02e improving the use of MgH2 for applications.

  11. Sulfur Doping Induces Strong Ferromagnetic Ordering in Graphene: Effect of Concentration and Substitution Mechanism.

    PubMed

    Tuček, Jiří; Błoński, Piotr; Sofer, Zdeněk; Šimek, Petr; Petr, Martin; Pumera, Martin; Otyepka, Michal; Zbořil, Radek

    2016-07-01

    Imprinting ferromagnetism to a graphene structure by substitution of carbon atoms with sulfur is reported. S-doped graphene (4.2 at%) shows strong ferromagnetic properties with saturation magnetization exceeding 5.5 emu g(-1) at 2 K, which is among the highest values reported for any sp-based system. The remarkable magnetic response is attributed to delocalization of electrons from sulfur injected into the graphene conduction band.

  12. Structural, dielectric and magnetic properties of nickel substituted cobalt ferrite nanoparticles: Effect of nickel concentration

    SciTech Connect

    Velhal, Ninad B.; Patil, Narayan D.; Puri, Vijaya R.; Shelke, Abhijeet R.; Deshpande, Nishad G.

    2015-09-15

    Nickel substituted cobalt ferrite nanoparticles with composition Co{sub 1−x}Ni{sub x}Fe{sub 2}O{sub 4} (0.0 ≤ x ≤ 1.0) was synthesized using simple, low temperature auto combustion method. The X-ray diffraction patterns reveal the formation of cubic phase spinel structure. The crystallite size varies from 30-44 nm with the nickel content. Porous and agglomerated morphology of the bulk sample was displayed in the scanning electron microscopy. Micro Raman spectroscopy reveals continuous shift of E{sub g} and E{sub g}(2) stokes line up to 0.8 Ni substitution. The dispersion behavior of the dielectric constant with frequency and the semicircle nature of the impedance spectra show the cobalt nickel ferrite to have high resistance. The ferromagnetic nature is observed in all the samples, however, the maximum saturation magnetization was achieved by the 0.4 Ni substituted cobalt ferrite, which is up to the 92.87 emu/gm at 30K.

  13. Sex differences in the effect of education on depression: resource multiplication or resource substitution?

    PubMed

    Ross, Catherine E; Mirowsky, John

    2006-09-01

    Does education improve psychological well-being more for one sex than for the other? Resource substitution theory hypothesizes that education improves well-being more for women, because socioeconomic disadvantage makes them depend more on education to achieve well-being. Resource multiplication implies the opposite, that education improves well-being more for men, because they get bigger labor market payoffs from it such as authority and earnings. Data from a 1995 survey of US adults with follow-ups in 1998 and 2001 support the resource substitution hypothesis. Depression decreases more steeply for women than for men as the level of education increases. The gender gap in depression essentially disappears among persons with a college degree or higher. Two mediating interactions appear to account for the convergence. Education increases work creativity more sharply for women than for men, thereby reducing depression. Education increases the sense of control for both sexes equally, but depression declines more steeply for women as sense of control increases. Growth curve analyses of depression vectors confirm the resource substitution pattern. The adulthood life course pattern of depression levels and changes depends more strongly on education for women than for men.

  14. Effect of strontium ions substitution on gene delivery related properties of calcium phosphate nanoparticles.

    PubMed

    Hanifi, A; Fathi, M H; Mir Mohammad Sadeghi, H

    2010-09-01

    Gene therapy has been considered a strategy for delivery of therapeutic nucleic acids to a specific site. Calcium phosphates are one gene delivery vector group of interest. However, low transfection efficiency has limited the use of calcium phosphate in gene delivery applications. Present work aims at studying the fabrication of strontium substituted calcium phosphate nanoparticles with improved gene delivery related properties. Strontium substituted calcium phosphate was prepared using a simple sol gel method. X-ray diffraction analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, specific surface area analysis, zeta potential measurement and ion release evaluation were used to characterize the samples. This characterization showed strontium and carbonate co-substituted calcium phosphate which resulted in nano size particles with low crystallinity, high specific surface area, positive surface charge, and a high dissolution rate. These improved properties could increase the DNA concentration on the vector as well as the endosomal escape of the complex that leads to higher transfection efficiency of this novel gene delivery vector.

  15. Effect of allelic variations at the Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on flour characteristics and bread loaf volume

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Doubled haploid wheat lines developed from a cross between Keumkang, a hard white winter wheat, and Olgeuru, soft red winter wheat were used to determine the effects of allelic variation in Glu-D1, Glu-A3, Glu-B3 and Pinb-D1 loci on physiochemical properties of flour and bread loaf volume. Variation...

  16. Effects of carbohydrate polymers applicable in saliva substitutes on the anti-Candida activity of a histatin-derived peptide.

    PubMed

    Ruissen, Anita L A; Groenink, Jasper; Lommerse, Cock H; Van 't Hof, Wim; Veerman, Enno C I; Nieuw Amerongen, Arie V

    2002-11-01

    The effects of polymers applicable in saliva substitutes on the anti-Candida activity of the cationic antimicrobial peptide dhvar1 were investigated. Dhvar1 is a derivative of the 14 C-terminal amino acids of histatin 5. The effects of the following polymers were tested: uncharged hydroxyethylcellulose (HEC), negatively charged xanthan (XG) and three types of negatively charged carboxymethylcellulose (CMC) of identical mass but different degrees of carboxylic acid-group substitution (DS). The effects were tested at pH 4.0, 7.0 and 8.5 in a killing assay. HEC had no effect at any pH tested; XG and the three types of CMC caused a decrease in activity at increasing concentrations. Within the CMC group, inhibition increased slightly with increasing DS. These results suggest that the reduction in activity associated with these polymers is the result of electrostatic interaction between the positively charged peptides and the negatively charged polymers. In the absence of polymers, no effect of pH was found on the activity of dhvar1. In the presence of the charged polymers XG and CMC, lowering the pH from 7.0 to 4.0 resulted in a decrease of dhvar1 activity. It was concluded that, with respect to the retention of activity, HEC is the most appropriate polymer for use in combination with dhvar1. However, for use in saliva substitutes XG seems more suitable because of its rheological properties. If XG or CMC are to be used, their reductive effect on the anti-Candida activity of dhvar1 should be compensated for by increasing the peptide dose.

  17. Integrated allelic, transcriptional, and phenomic dissection of the cardiac effects of titin truncations in health and disease.

    PubMed

    Roberts, Angharad M; Ware, James S; Herman, Daniel S; Schafer, Sebastian; Baksi, John; Bick, Alexander G; Buchan, Rachel J; Walsh, Roddy; John, Shibu; Wilkinson, Samuel; Mazzarotto, Francesco; Felkin, Leanne E; Gong, Sungsam; MacArthur, Jacqueline A L; Cunningham, Fiona; Flannick, Jason; Gabriel, Stacey B; Altshuler, David M; Macdonald, Peter S; Heinig, Matthias; Keogh, Anne M; Hayward, Christopher S; Banner, Nicholas R; Pennell, Dudley J; O'Regan, Declan P; San, Tan Ru; de Marvao, Antonio; Dawes, Timothy J W; Gulati, Ankur; Birks, Emma J; Yacoub, Magdi H; Radke, Michael; Gotthardt, Michael; Wilson, James G; O'Donnell, Christopher J; Prasad, Sanjay K; Barton, Paul J R; Fatkin, Diane; Hubner, Norbert; Seidman, Jonathan G; Seidman, Christine E; Cook, Stuart A

    2015-01-14

    The recent discovery of heterozygous human mutations that truncate full-length titin (TTN, an abundant structural, sensory, and signaling filament in muscle) as a common cause of end-stage dilated cardiomyopathy (DCM) promises new prospects for improving heart failure management. However, realization of this opportunity has been hindered by the burden of TTN-truncating variants (TTNtv) in the general population and uncertainty about their consequences in health or disease. To elucidate the effects of TTNtv, we coupled TTN gene sequencing with cardiac phenotyping in 5267 individuals across the spectrum of cardiac physiology and integrated these data with RNA and protein analyses of human heart tissues. We report diversity of TTN isoform expression in the heart, define the relative inclusion of TTN exons in different isoforms (using the TTN transcript annotations available at http://cardiodb.org/titin), and demonstrate that these data, coupled with the position of the TTNtv, provide a robust strategy to discriminate pathogenic from benign TTNtv. We show that TTNtv is the most common genetic cause of DCM in ambulant patients in the community, identify clinically important manifestations of TTNtv-positive DCM, and define the penetrance and outcomes of TTNtv in the general population. By integrating genetic, transcriptome, and protein analyses, we provide evidence for a length-dependent mechanism of disease. These data inform diagnostic criteria and management strategies for TTNtv-positive DCM patients and for TTNtv that are identified as incidental findings.

  18. Effect of annealing on structural and magnetic properties of Al substituted nanocrystalline Fe-Si-Co alloy powders

    NASA Astrophysics Data System (ADS)

    Shyni, P. C.; Alagarsamy, Perumal

    2016-11-01

    We report effects of annealing and substitution of Al on structural and magnetic properties of nanocrystalline Fe80-xAlxCo5Si15 (x=0-10) alloy powders prepared by mechanical alloying process using a planetary ball mill technique. All the as-milled powders exhibit non-equilibrium solid solution of α-Fe (Si,Co,Al). While the average size of crystals decreases, the lattice constant and dislocation density increase with increasing Al content. On the other hand, the annealing at elevated temperatures increases the size of the crystals and decreases the dislocation density. In addition, the substitution of Al in FeAlCoSi alloy powders controls growth of the crystals during annealing. As a result, coercivity (HC) of the annealed powders decreases considerably. However, the variation in HC is dominated by the dislocation density. Fe70Al10Co5Si15 powder annealed at 900 °C exhibits improved magnetic properties (HC~14 Oe and moderate magnetization of 160 emu/g) due to optimum nanocrystalline microstructure with fine nanocrystals (~18 nm) and reduced dislocation density. Systematic correlations observed between structural and magnetic properties for Fe80-xAlxCo5Si15 powders reveal a promising approach to control the growth of the crystals in the annealed nanocrystalline alloys and to improve the magnetic properties of mechanically alloyed Fe-Si based nanocrystalline alloys by adding suitable substituting elements.

  19. Effect of Sr substitution on irreversibility line, lattice dynamics and formation of Hg,Pb-1223 superconductors

    NASA Astrophysics Data System (ADS)

    Lee, Sergey; Kiryakov, N. P.; Emelyanov, D. A.; Kuznetsov, M. S.; Tretyakov, Yu. D.; Petrykin, V. V.; Kakihana, M.; Yamauchi, H.; Zhuo, Yi; Kim, Mun-Seog; Lee, Sung-Ik

    1998-09-01

    Effect of Sr substitution on irreversible properties and lattice dynamics of Hg,Pb-1223 phases was studied. We found that flux pinning properties in high magnetic fields essentially improved by substitutions of Hg by Pb and Ba by Sr. Consideration of lattice dynamics figured out the role of lead and strontium on phase stability and hole doping of CuO 2 layers. Investigation of phase composition and microstructural features of the samples allowed us to suggest a possible mechanism of Hg,Pb-1223 phase formation. The substituted samples possessed an improved chemical stability and allowed their further utilization for materials preparation. As an example, nearly single phase thick film on MgO substrate with the Tc of 120 K was obtained by screen printing method. Despite of the very high intragrain critical current density ( jc=3×10 5 A/cm 2, H=0, 77 K), transport jc was restricted by formation of `weak links' on the grain boundaries.

  20. Theoretical investigation of the substituent effects on the electronic and optical properties of 6-substituted coumarin derivatives

    NASA Astrophysics Data System (ADS)

    Bai, Yihui; Zhang, Fang; Ying, Jin; Wu, Yingzi

    2015-06-01

    The electronic structures, absorption and emission spectra of selected 6-substituted coumarins were investigated and compared with unsubstituted coumarin by using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods with Gaussian 09 software package. Results revealed that the presented absorption and emission spectra were affected by the substituent groups apparently. The maximum absorption wavelength of a coumarin molecule can be shifted to a longer one by introducing a large conjugated substituent, an electron donating group or a group which can form a rigid structure with the parent moiety at 6-position. The lowest energy emission of a 6-substituted coumarin can be greatly red-shifted by modifying the substituent to one which can be strongly conjugated with the phenyl ring. A group which has a strongly electron-withdrawing effect may cause a large excitation intensity and a short wavelength in emission. Most selected molecules are predicted to give the lowest-energy emissions in the purple or blue light region, which are supposed to be selected and modified as purple or blue luminescent materials. 6-nitrocoumarin is predicted as an invisible fluorescent material. 6,7-benzocoumarin, which forms a rigid conjugated ring with the parent moiety, is expected to be modified as a green luminescent material. Many of these 6-substituted coumarins are expected to be potential candidates as large Stokes shift dyes for multicolor labeling and fluorescence-activated cell sorting (FACS), especially those molecules, which bear sbnd CONH2, sbnd CN, and sbnd CH3 respectively.

  1. Dialkylthio Substitution: An Effective Method to Modulate the Molecular Energy Levels of 2D-BDT Photovoltaic Polymers.

    PubMed

    Yao, Huifeng; Zhang, Hao; Ye, Long; Zhao, Wenchao; Zhang, Shaoqing; Hou, Jianhui

    2016-02-17

    Dialkylthio-substituted thienyl-benzodithiophene (BDT-DST) was designed and synthesized as a building block to modulate the molecular levels of the conjugated polymers, and three copolymers named PDST-BDD, PDST-TT and PDST-DPP were prepared and applied in polymer solar cells (PSCs). Theoretical calculations and electrochemical cyclic voltammetry (CV) measurement suggested that the dialkylthio group could decrease the molecular energy levels of the resulting polymers distinctly. The open-circuit voltage (VOC) of PSC devices based on PDST-BDD, PDST-TT, and PDST-DPP are as high as 1.0, 0.98, and 0.88 V, respectively, which are ∼0.15 V higher than those of the corresponding alky-substituted analogues. Moreover, the influence of the dialkylthio group on the absorption spectra, crystalline properties, hole mobilities, and blend morphologies of the polymers was also investigated. The results indicate that the dialkythio substitution is an effective method to modulate the molecular energy levels and that the BDT-DST unit has potential for constructing high-efficiency photovoltaic polymers.

  2. Effect of five-membered ring and heteroatom substitution on charge transport properties of perylene discotic derivatives: A theoretical approach.

    PubMed

    Navarro, Amparo; Fernández-Liencres, M Paz; Peña-Ruiz, Tomás; García, Gregorio; Granadino-Roldán, José M; Fernández-Gómez, Manuel

    2016-08-07

    Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ∼0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ∼0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

  3. Effect of five-membered ring and heteroatom substitution on charge transport properties of perylene discotic derivatives: A theoretical approach

    NASA Astrophysics Data System (ADS)

    Navarro, Amparo; Fernández-Liencres, M. Paz; Peña-Ruiz, Tomás; García, Gregorio; Granadino-Roldán, José M.; Fernández-Gómez, Manuel

    2016-08-01

    Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ˜0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ˜0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

  4. Effect of Gd3+ substitution on structural, magnetic, dielectric and optical properties of nanocrystalline CoFe2O4

    NASA Astrophysics Data System (ADS)

    Joshi, Seema; Kumar, Manoj; Chhoker, Sandeep; Kumar, Arun; Singh, Mahavir

    2017-03-01

    Nanoparticles of CoGdxFe2-xO4 with x=0.0, 0.03, 0.05, 0.07, 0.10 and 0.15 were synthesized by co-precipitation method. Gd3+ substitution effect on different properties of nanocrystalline CoFe2O4 has been studied. X-ray diffraction and Raman spectroscopy confirmed the formation of single phase cubic mixed spinel structure. Cation distribution has been proposed from Rietveld refined data. Mössbauer spectra at room temperature showed two ferrimagnetic Zeeman sextets with one superparamagnetic doublet. Mössbauer parameters suggested that Gd3+ ions occupy the octahedral site in CoFe2O4. Room temperature magnetic measurements exhibited that the saturation magnetization decreased from 91 emu/gm to 54 emu/gm for x=0.0 to 0.15 samples. The coercivity decreased from 1120 Oe to 340 Oe for x=0.0 to 0.07 samples and increased from 400 Oe to 590 Oe for x=0.10 and 0.15 samples, respectively. Raman analysis showed that the degree of inversion with Gd3+ substitution supporting the variation of coercivity. Electron spin resonance spectra revealed the dominancy of superexchange interactions in these samples. Optical band gap measurement suggested that all samples are indirect band gap materials and band gap has been decreased with Gd3+ substitution. Both dielectric constant and dielectric loss is found to decrease because of the decrease in hopping rate with the Gd3+ substitution for Fe3+ at the octahedral sites. Low dielectric loss suggested the applicability of Gd3+ doped CoFe2O4 nanoparticles for high frequency microwave device applications.

  5. The effect of altered dosage of a mutant allele of Teosinte branched 1 (tb1-ref) on the root system of modern maize

    PubMed Central

    2014-01-01

    Background There was ancient human selection on the wild progenitor of modern maize, Balsas teosinte, for decreased shoot branching (tillering), in order to allow more nutrients to be diverted to grain. Mechanistically, the decline in shoot tillering has been associated with selection for increased expression of the major domestication gene Teosinte Branched 1 (Tb1) in shoot primordia. Therefore, TB1 has been defined as a repressor of shoot branching. It is known that plants respond to changes in shoot size by compensatory changes in root growth and architecture. However, it has not been reported whether altered TB1 expression affects any plant traits below ground. Previously, changes in dosage of a well-studied mutant allele of Tb1 in modern maize, called tb1-ref, from one to two copies, was shown to increase tillering. As a result, plants with two copies of the tb1-ref allele have a larger shoot biomass than heterozygotes. Here we used aeroponics to phenotype the effects of tb1-ref copy number on maize roots at macro-, meso- and micro scales of development. Results An increase in the tb1-ref copy number from one to two copies resulted in: (1) an increase in crown root number due to the cumulative initiation of crown roots from successive tillers; (2) higher density of first and second order lateral roots; and (3) reduced average lateral root length. The resulting increase in root system biomass in homozygous tb1-ref mutants balanced the increase in shoot biomass caused by enhanced tillering. These changes caused homozygous tb1-ref mutants of modern maize to more closely resemble its ancestor Balsas teosinte below ground. Conclusion We conclude that a decrease in TB1 function in maize results in a larger root system, due to an increase in the number of crown roots and lateral roots. Given that decreased TB1 expression results in a more highly branched and larger shoot, the impact of TB1 below ground may be direct or indirect. We discuss the potential implications

  6. Rennet paste from lambs fed a milk substitute supplemented with Lactobacillus acidophilus: effects on lipolysis in ovine cheese.

    PubMed

    Santillo, A; Quinto, M; Dentico, M; Muscio, A; Sevi, A; Albenzio, M

    2007-07-01

    The present work was undertaken to evaluate the effects of Lactobacillus acidophilus supplementation of a milk substitute on the features of lamb rennet paste used for cheese making. Lipolysis in cheese manufactured with rennet paste from lambs receiving supplemented milk was also evaluated. Lambs were subjected to 3 different feeding regimens (mother suckling, MS; artificial rearing, AR; and artificial rearing with 7 log10 cfu/mL of Lb. acidophilus supplementation of the milk substitute, ARLb) and slaughtered at 20 and 40 d of age for each feeding treatment. Abomasa of the lambs were processed to rennet paste. Microbial loads, enzymatic activities (chymosin, pepsin, and lipases), and renneting characteristics of the lamb rennet paste were determined. Free fatty acids and conjugated linoleic acids were detected in cheese at 60 d of ripening. Addition of 7 log10 cfu/mL of Lb. acidophilus to the milk substitute was carried out successfully. Total recovery of viable cells was recorded in milk supplied daily to the lambs in the ARLb group. The ARLb rennet had greater amounts of lactobacilli than did the MS or AR rennet, irrespective of the slaughter age of the lambs, and the ARLb rennet had higher concentrations of lactococci when lambs were slaughtered at 40 d of age. Chymosin and lipase activities were also higher in ARLb rennet than in MS or AR rennet from lambs slaughtered at an older age. Milk supplementation of ARLb lambs resulted in improved coagulating ability of the rennet and enhanced cheese lipolysis after 60 d of ripening. A reduction of all free fatty acids was observed in all cheeses when passing from 20 to 40 d of slaughter of the lambs. Conjugated linoleic acids were more abundant in ARLb cheeses at both 20 and 40 d. Therefore, supplementation of the milk substitute with Lb. acidophilus improved the enzymatic features of rennet and the healthful and nutritional characteristics of it the ovine cheese. Moreover, the addition of lactobacilli to the milk

  7. Identification of two novel human CD1E alleles.

    PubMed

    Mirones, I; Oteo, M; Parra-Cuadrado, J F; Martínez-Naves, E

    2000-08-01

    CD1 is a family of proteins structurally related to major histocompatibility complex (MHC) molecules and specialized in presenting lipids or glycolipids to T cells. In humans, there are five CD1 genes (CD1A to CD1E). It has been shown that, in contrast with classical MHC genes, CD1 loci display a very limited polymorphism. In the present work we describe two novel CD1E alleles found in two healthy Caucasian individuals. One allele differs from the wild-type by a point mutation resulting in a replacement of arginine at position 154 by a tryptophan. In the second allele we found a substitution of the leucine 184 by a proline.

  8. The effect of Al-substitution on superconducting type-I clathrate Ba8Si46

    NASA Astrophysics Data System (ADS)

    Liu, Lihua; Bi, Shanli; Chen, Ning; Li, Feng; Liu, Yang; Cao, Guohui; Li, Yang

    2014-11-01

    A series of samples with the chemical formula Ba8Si46-xAlx (x = 2, 3, 5, 6, 7 and 8) were prepared by arc melting, ball milling and washing with diluted HCl. The lattice parameter of Ba8Si46-xAlx increases linearly with the increase of nominal Al content x. The composition analysis by energy-dispersive X-ray spectroscopy (EDS) shown that the actual Al contents in clathrates are lager than the nominal compositions because the dilute Al-contained impurity phases were washed out. The experimental results show that the minimum incorporation of Al into clathrate structure is expected to be about 3 at ambient pressure, which is in agreement with a first-principle simulation. The Al substitution for Si results in the decrease of superconducting transition temperature TC, which can be explained on the BCS theoretical frame. The electron density of state at Fermi level N(EF) decreases with the increment of x except for an abnormal increase for the sample x = 6. Such sample has a higher spatial symmetry of the structure in which all the six Si atoms at 6c sites were substituted by Al atoms. Its higher N(EF) causes to a higher TC. In addition, we calculated the phonon-dispersion relations and vibrational density of states for Al-doped silicon clathrates. The high frequency acoustic branch has a red shift from 430 cm-1 to 420 cm-1 with the doping of Al. The decreased frequency of bond-stretching vibration modes is another reason for the suppression of TC induced by Al substitution.

  9. Effect of samarium substitution on structural and magnetic properties of magnesium ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Thankachan, Smitha; Jacob, Binu P.; Xavier, Sheena; Mohammed, E. M.

    2013-12-01

    Samarium doped magnesium ferrite was prepared (MgSmxFe2-xO4) by sol-gel method. X-ray diffraction analysis reveals that the samples are single phasic with crystallite sizes in the 13-25 nm regime. Increase in lattice parameter with doping concentration suggests the expansion in unit cell with Sm3+ doping. Fourier Transform Infrared Spectrum shows substitution of Sm3+ ions in octahedral B site. Transmission Electron Micrograph shows the spherical shape of nano-particles. Magnetic measurement shows a decrease in magnetization with doping which is explained using dependence on particle size.

  10. Effect of substitutional doping on temperature dependent electrical parameters of amorphous Se-Te semiconductors

    NASA Astrophysics Data System (ADS)

    Sharma, Neha; Sharda, Sunanda; Sharma, Dheeraj; Sharma, Vineet; Barman, P. B.; Katyal, S. C.; Sharma, Pankaj; Hazra, S. K.

    2013-09-01

    Steady state current-voltage characteristics of the amorphous (Se80Te20)98Y2 (Y = Ag, Bi, Ge, Cd) semiconductors at different temperatures are reported. The measurements were performed using direct-current voltage bias to understand the basic conductivity mechanism and to evaluate the impact of each substituent on electrical response. The space charge limited conduction mechanism, and the density of states near Fermi level have been calculated. The difference in electrical response due to different substitutions in the glassy matrix is analyzed.

  11. Ecological interactions and the fitness effect of water-use efficiency: Competition and drought alter the impact of natural MPK12 alleles in Arabidopsis.

    PubMed

    Campitelli, Brandon E; Des Marais, David L; Juenger, Thomas E

    2016-04-01

    The presence of substantial genetic variation for water-use efficiency (WUE) suggests that natural selection plays a role in maintaining alleles that affect WUE. Soil water deficit can reduce plant survival, and is likely to impose selection to increase WUE, whereas competition for resources may select for decreased WUE to ensure water acquisition. We tested the fitness consequences of natural allelic variation in a single gene (MPK12) that influences WUE in Arabidopsis, using transgenic lines contrasting in MPK12 alleles, under four treatments; drought/competition, drought/no competition, well-watered/competition, well-watered/no competition. Results revealed an allele × environment interaction: Low WUE plants performed better in competition, resulting from increased resource consumption. Contrastingly, high WUE individuals performed better in no competition, irrespective of water availability, presumably from enhanced water conservation and nitrogen acquisition. Our findings suggest that selection can influence MPK12 evolution, and represents the first assessment of plant fitness resulting from natural allelic variation at a single locus affecting WUE.

  12. Alleles versus mutations: Understanding the evolution of genetic architecture requires a molecular perspective on allelic origins.

    PubMed

    Remington, David L

    2015-12-01

    Perspectives on the role of large-effect quantitative trait loci (QTL) in the evolution of complex traits have shifted back and forth over the past few decades. Different sets of studies have produced contradictory insights on the evolution of genetic architecture. I argue that much of the confusion results from a failure to distinguish mutational and allelic effects, a limitation of using the Fisherian model of adaptive evolution as the lens through which the evolution of adaptive variation is examined. A molecular-based perspective reveals that allelic differences can involve the cumulative effects of many mutations plus intragenic recombination, a model that is supported by extensive empirical evidence. I discuss how different selection regimes could produce very different architectures of allelic effects under a molecular-based model, which may explain conflicting insights on genetic architecture from studies of variation within populations versus between divergently selected populations. I address shortcomings of genome-wide association study (GWAS) practices in light of more suitable models of allelic evolution, and suggest alternate GWAS strategies to generate more valid inferences about genetic architecture. Finally, I discuss how adopting more suitable models of allelic evolution could help redirect research on complex trait evolution toward addressing more meaningful questions in evolutionary biology.

  13. Study of structural effect on Eu-substituted LSMO manganite for high temperature coefficient of resistance

    NASA Astrophysics Data System (ADS)

    Vadnala, Sudharshan; Durga Rao, T.; Pal, Prem; Asthana, Saket

    2014-09-01

    In this work, Eu substituted La0.7Sr0.3MnO3 (LSMO) is studied to achieve high temperature coefficient of resistance (TCR). The compounds La0.7-xEuxSr0.3MnO3 with x=0, 0.1 0.2 and 0.3 are prepared by solid state reaction route and their structural and transport properties are examined by different characterization techniques. The metal-semiconductor/insulator transition temperature (TMI) decreases from 390 K (for x=0) to 240 K (for x=0.3) with decrease in average ionic radius of A-site. The maximum TCR percentage of La0.7-xEuxSr0.3MnO3 compound is found to be increased for x=0.2 (1.9%) and for x=0.3 (3.36%) compared to its parent compound La0.7Sr0.3MnO3 (1.1%). The substitution of Eu increases the lattice distortion, which enhances the TCR value from 1.1% to 3.36%. The robustness of distortion increases with decreasing which is well correlated with the high magneto-resistance, and high TCR findings.

  14. Selenium-substituted hydroxyapatite nanoparticles and their in vivo antitumor effect on hepatocellular carcinoma.

    PubMed

    Yanhua, Wang; Hao, Hang; Li, Yan; Zhang, Shengmin

    2016-04-01

    Absence of curative treatment creates urgent need for new strategies for unresectable hepatoma. Novel selenium-substituted hydroxyapatite nanoparticles (SeHAN) were designed to serve as anticancer agent. The authors examined the nanoparticles by physicochemical techniques. The in vivo efficacy and toxicity of these nanoparticles were also investigated on a nude mice model of human hepatocellular carcinoma. The results showed that the selenite ions can be incorporated into the hydroxyapatite lattice facilely. They exhibited bundles of needles shape with a size of 160-200 nm. In the in vivo study, they showed better survival advantage. The overall survival rate of nude mice in the control, pure hydroxyapatite and SeHAN group were 50.00%, 76.92%, and 100.00% respectively. Blood biochemical studies showed that SeHAN group had significantly lower toxicities on the liver and kidney functions. Histopathological studies confirmed that massive tumor necrosis and calcium deposition were evident after SeHAN treatment. Moreover, immunohistochemistry and Western blot assay showed significantly reduced expression of the Ki-67, VEGF and MMP-9 protein in the SeHAN group. Taken together, these results suggest that the selenium-substituted hydroxyapatite nanoparticles could be a new type of promising anticancer agent to provide both survival advantage and lower toxicity.

  15. Effect of rare earth substitution in the density of electronic states of LnOFeAs

    NASA Astrophysics Data System (ADS)

    García Saravia Ortíz de Montellano, A.; Mustre de León, J.; Saini, N. L.; Bianconi, A.

    2012-06-01

    Measurements of the Fe K-edge x-ray absorption near edge (XANES) spectra of LnOFeAs (Ln being a lanthanide) high Tc superconductors exhibit significant changes in the pre-edge peak region upon rare earth substitution. Ab initio XANES calculations, based on the local structure centered at the Fe site obtained by crystallographic investigations, reproduce the observed changes in the spectra, indicating variations of the Fe d-local unoccupied electronic states. The calculated Fe density of states (DOS) at the Fermi energy shows an increase of the Fe d-density of states with increasing height of the arsenic atomic position with respect to the iron plane, similar to that observed for the superconducting transition temperature, Tc. These calculations show that not only the atomic position variation of the Fe-As layers induced by the rare earth substitution is relevant in the increase of the DOS at the Fermi-level, but the actual change in electronic configuration of the rare earth also plays a role in the increase of Fe d-density of states at the Fermi energy.

  16. Effect of sintering temperature on the structural, dielectric and ferroelectric properties of tungsten substituted SBT ceramics

    NASA Astrophysics Data System (ADS)

    Coondoo, Indrani; Panwar, Neeraj; Jha, A. K.

    2011-02-01

    Structural, dielectric and ferroelectric properties of tungsten (W) substituted SrBi 2(Ta 1- xW x) 2O 9 (SBTW) [ x=0.0, 0.025, 0.05, 0.075, 0.1 and 0.2] have been studied as a function of sintering temperature (1100-1250 °C). X-ray diffraction patterns confirm the single-phase layered perovskite structure formation up to x=0.05 at all sintering temperatures. The present study reveals an optimum sintering temperature of 1200 °C for the best properties of SBTW samples. Maximum Tc of ∼390 °C is observed for x=0.20 sample sintered at 1200 °C. Peak-dielectric constant ( εr) increases from ∼270 to ∼700 on increasing x from 0.0 to 0.20 at 1200 °C sintering temperature. DC conductivity of the SBTW samples is nearly two to three orders lower than that of the pristine sample. Remnant polarization ( Pr) increases with the W content up to x≤0.075. A maximum 2 Pr (∼25 μC/cm 2) is obtained with x=0.075 sample sintered at 1200 °C. The observed behavior is explained in terms of improved microstructural features, contribution from the oxygen and cationic vacancies in SBTW. Such tungsten substituted samples sintered at 1200 °C exhibiting enhanced dielectric and ferroelectric properties should be useful for memory applications.

  17. The effect of modified potato flour substitution on the organoleptics characteristics of toddler biscuit

    NASA Astrophysics Data System (ADS)

    Cakrawati, Dewi; Rahmawati, Puji

    2016-04-01

    Toddler biscuit is complementary food given to infants to help meet their nutritional needs. This research was undertaken to develop toddler biscuit with subtitution of physically modified potato flour. There were two puposes of the research, first to know the characteristics of physically modification on potato flour; secondly to know biscuit characteristics with modified potato flour substitution. There were two factor analysis in the development of biscuit; first factor was pre heating mehods and substitution rate. The research was conducted with experimental method using split plot design. The functional properties on modified potato flour as swelling capacity, water absorption capacity, solubility and viscocity were analyzed. Organoleptic analysis using quality hedonic test showed no interaction between potato starch modification and concentration of modified potato flour. Quality hedonic test showed all toddler biscuit socred in the range of “slightly like” to “like moderately”. Modifying potato starch by boiling and steaming with flour concentration of 30% producing toddler biscuit with organoleptic characteristics acceptable according to the panelists.

  18. The effect of gallium substitution on the microstructure and magnetic properties of yttrium iron garnet

    SciTech Connect

    Zaini, N. Z. M. Ibrahim, N. B.

    2015-09-25

    Y{sub 3}Fe{sub (5-y)}Ga{sub y}O{sub 12} (y = 0, 0.4, 1.4 and 2,4) thin films were prepared by sol-gel method and annealed for 2h in oxygen. The thin film’s characteristic were studied by an X-ray diffraction (XRD), a field emission scanning electron microscope (FESEM) and a vibration sample magnetometer (VSM). The XRD show that all films have the garnet phase structure. The grain size particles measured using FESEM were between 45.08 nm to 51.58 nm, and the thickness were between 42 nm to 90 nm. The magnetic properties measured using VSM showed that result was shown with hysteresis loop. The magnetization saturation decreased from 144.26 to 2.76 emu/cm{sup 3} with the increasing substitution gallium. The substitution for y = 2.4 was shown the saturation magnetization was very low. The coercivity increased 35 to 75 Oe due the the increasing grain size.

  19. [The differences of the effects of Vrd1 and Ppd-D1 gene alleles on winterhardiness, frost resistance, and yield in winter wheat].

    PubMed

    Mokanu, N V; Faĭt, V I

    2008-01-01

    The influence of allelic differences of Vrd1 and Ppd-D1 genes on winterhardiness, frost resistance, yield and its components was studied in recombinant-inbred F5 lines of Odesskaya 16/Bezostaya 1. From 9 to 15% differences in the resistance of recombinant-inbred lines were determined by alternative alleles of Vrd1 gene and 10-16% of Ppd-D1 gene. Interaction of vrd1 and Ppd-D1a alleles led to the higher winterhardiness and frost resistance of tillered plants during the winter. At the same time the significant increase of the period to heading, plant height and the tendency of yield reduction were revealed for vrd1 vrd1 Ppd-D1a Ppd-D1a lines when compared to the lines of Vrd1 Vrd1 Ppd-D1a Ppd-D1a genotype.

  20. Effects of cation disorder and size on metamagnetism in A-site substituted Pr0.5Ca0.5MnO3 system

    NASA Astrophysics Data System (ADS)

    Mavani, K. R.; Paulose, P. L.

    2005-04-01

    The effects of A-site cation disorder and size on metamagnetism of ABO3 type charge and orbital ordered Pr0.5Ca0.5MnO3 system have been studied by substituting Ba+2 for Ca+2 or La+3 for Pr+3. Substitution of 5% Ba+2 or 5% La+3 drastically reduces the critical magnetic field (Hc) for metamagnetism and induces successive steplike metamagnetic transitions at low temperatures. Interestingly, with further increase in substitution, Hc rises. We find that there is a sharp decrease in electrical resistivity corresponding to the metamagnetic transitions, which is indicative of strongly correlated magnetic and electronic transitions in these manganites.

  1. Ab initio study of effect of Co substitution on the magnetic properties of Ni and Pt-based Heusler alloys

    NASA Astrophysics Data System (ADS)

    Roy, Tufan; Chakrabarti, Aparna

    2017-04-01

    Using density functional theory based calculations, we have carried out in-depth studies of effect of Co substitution on the magnetic properties of Ni and Pt-based shape memory alloys. We show the systematic variation of the total magnetic moment, as a function of Co doping. A detailed analysis of evolution of Heisenberg exchange coupling parameters as a function of Co doping has been presented here. The strength of RKKY type of exchange interaction is found to decay with the increase of Co doping. We calculate and show the trend, how the Curie temperature of the systems vary with the Co doping.

  2. Amido-Schiff base derivatives as colorimetric fluoride sensor: Effect of nitro substitution on the sensitivity and color change.

    PubMed

    Ghosh, Soumen; Alam, Md Akhtarul; Ganguly, Aniruddha; Guchhait, Nikhil

    2015-01-01

    A series of Schiff bases synthesized by the condensation of benzohydrazide and -NO2 substituted benzaldehyde have been used as selective fluoride ion sensor. Test paper coated with these synthetic Schiff bases (test kits) can detect fluoride ion selectively with a drastic color change and detection can be achieved by just using the naked-eye without the help of any optical instrument. Interestingly, the position of -NO2 group in the amido Schiff bases has an effect on the sensitivity as well as on the change of color of species.

  3. Substituted hydroxyapatites for bone repair.

    PubMed

    Shepherd, Jennifer H; Shepherd, David V; Best, Serena M

    2012-10-01

    Calcium phosphates such as hydroxyapatite have a wide range of applications both in bone grafts and for the coating of metallic implants, largely as a result of their chemical similarity to the mineral component of bone. However, to more accurately mirror the chemistry, various substitutions, both cationic (substituting for the calcium) and anionic (substituting for the phosphate or hydroxyl groups) have been produced. Significant research has been carried out in the field of substituted apatites and this paper aims to summarise some of the key effect of substitutions including magnesium, zinc, strontium, silicon and carbonate on physical and biological characteristics. Even small substitutions have been shown to have very significant effects on thermal stability, solubility, osteoclastic and osteoblastic response in vitro and degradation and bone regeneration in vivo.

  4. Three hundred and seventy-two novel HLA class II alleles identified in potential hematopoietic stem cell donors from Germany, the United States, and Poland.

    PubMed

    Hernández-Frederick, C J; Cereb, N; Giani, A S; Ruppel, J; Maraszek, A; Pingel, J; Sauter, J; Schmidt, A H; Yang, S Y

    2014-11-01

    We have characterized 372 novel human leukocyte antigen (HLA) class II alleles identified in newly registered stem cell donors, this includes 281 HLA-DRB1 alleles, 89 HLA-DQB1 alleles and 2 HLA-DPB1 alleles. Most novel alleles were single nucleotide variants when compared to their respective most homologous alleles. In 66.4% of all novel alleles non-synonymous nucleotide variations were identified, in 30.4% synonymous substitutions and in 3.2% nonsense mutations. Ninty-three (25.0%) novel alleles were found in several individuals; most often these were novel HLA-DRB1 alleles. Lastly, we underline the importance of recruiting ethnic minority donors in countries such as Germany and the United States, as novel alleles were frequently found among these groups.

  5. Effect of Fluorine Substitution on Photovoltaic Properties of Alkoxyphenyl Substituted Benzo[1,2-b:4,5-b']dithiophene-Based Small Molecules.

    PubMed

    Qiu, Beibei; Yuan, Jun; Xiao, Xuxian; He, Dingjun; Qiu, Lixia; Zou, Yingping; Zhang, Zhi-guo; Li, Yongfang

    2015-11-18

    Two new small molecules, C3T-BDTP and C3T-BDTP-F with alkoxyphenyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDT) and meta-fluorinated-alkoxyphenyl-substituted BDT as the central donor blocks, respectively, have been synthesized and used as donor materials in organic solar cells (OSCs). With the addition of 0.4% v/v 1,8-diiodooctane (DIO), the blend of C3T-BDTP-F/PC71BM showed a higher hole mobility of 8.67 × 10(-4) cm(2) V(-1) s(-1) compared to that of the blend of C3T-BDTP/PC71BM. Two types of interlayers, zirconium acetylacetonate (ZrAcac) and perylene diimide (PDI) derivatives (PDINO and PDIN), were used to further optimize the performance of OSCs. With a device structure of ITO/PEDOT:PSS/donor:PC71BM/PDIN/Al, the OSCs based on C3T-BDTP delivered a satisfying power conversion efficiency (PCE) of 5.27% with an open circuit voltage (V(oc)) of 0.91 V, whereas the devices based on C3T-BDTP-F showed an enhanced PCE of 5.42% with a higher V(oc) of 0.97 V.

  6. Adsorption and substitution effects of Mg on the growth of calcium sulfate hemihydrate: An ab initio DFT study

    NASA Astrophysics Data System (ADS)

    Xin, Yan; Hou, S. C.; Xiang, Lan; Yu, Yang-Xin

    2015-12-01

    Calcium sulfate hemihydrate (CaSO4·0.5H2O, CSH) whiskers with high aspect ratio are promising reinforce materials which have drawn much attention. In order to obtain high quality CSH materials, effect of Mg2+ ions on properties of the (0 0 2), (2 0 0)1 and (2 0 0)2 planes of CSH is investigated using an ab initio density functional theory (DFT) with a van der Waals (vdW) dispersion-correction. The computed results show that strong adsorption and substitution effects take place between Mg2+ ion and (2 0 0)1 plane. The adsorption energies of an Mg2+ ion on the (0 0 2), (2 0 0)1 and (2 0 0)2 planes are -0.066, -0.571 and -0.047 eV, respectively. An insight into the electrostatic potential of pristine CSH planes has demonstrated that the (2 0 0)1 plane is much more negatively charged than the (0 0 2) and (2 0 0)2 planes. The energies of the substitution of a Ca atom with an Mg atom on the CSH (0 0 2), (2 0 0)1 and (2 0 0)2 planes are 1.572, 0.063 and 1.349 eV, respectively. It is found that Ca atoms on the (2 0 0)1 plane are relatively easy to be substituted by Mg atoms. The calculation results of a Ca2+ ion adsorption on the Mg-doped (2 0 0)1 plane indicate that the adsorption energies increase apparently as the doping ratio varies from 0 to 1.0. Compared with K+, Na+ and Al3+ ions, Mg2+ ion is the most promising additive to promote the growth of CSH along c axis.

  7. Structural transition and its effect in La, Zr co-substituted mono-domain BiFeO3

    NASA Astrophysics Data System (ADS)

    Usama, Hasan M.; Sharif, Ahmed; Zubair, M. A.; Gafur, M. A.; Hoque, Sheikh Manjura

    2016-12-01

    A new approach was employed in explaining the weak ferromagnetic behavior of conventionally synthesized Zr4+ modified Bi0.8La0.2FeO3. Rietveld refinement of XRD patterns revealed a polar-to-non-polar R3c → Pnma structural transition in Zr4+substituted samples. Magnetic properties were discovered to be remarkably enhanced, with extracted coercivity and remanence as high as 14 kOe and 0.2 emu/g, respectively. More importantly, an answer to the essential question of the magnetic domain state of the samples has been put forward. Our analysis established, nearly without doubt, the presence of grains consisting of a single magnetic domain. Separated ferromagnetic and anti-ferromagnetic components of the total M-H curves helped to reveal an immense effect of the structural transition on the shape of the hysteresis loops. The orthorhombic magnetocrystalline anisotropy of the Pnma phase has been primarily deemed responsible for the high coercivity and remanence of the Zr4+ modified samples. The effect of the grain size and Fe-O-Fe bond angle on the magnetic properties of the samples has also been discussed. Ferroelectricity was found to be absent in Zr-substituted samples because of their non-polar structure. However, the leakage current was reduced by up to two orders of magnitude compared to Bi0.8La0.2FeO3 upon addition of Zr4+. Dielectric measurements conformed to the ferroelectric and leakage current characteristics, and Zr4+ substitution was again found to be beneficial.

  8. Substituted Diarylnorbornadienes and Quadricyclanes: Synthesis, Photochemical Properties, and Effect of Substituent on the Kinetic Stability of Quadricyclanes.

    PubMed

    Spivack, Kyle J; Walker, Jesse V; Sanford, Maria J; Rupert, Benjamin R; Ehle, Andrew R; Tocyloski, James M; Jahn, Aaron N; Shaak, Lyndsey M; Obianyo, Obiamaka; Usher, Karyn M; Goodson, Felix E

    2017-02-03

    In this Article, we present a new method for the synthesis of diarylnorbornadiene derivatives. Through the use of a two-step procedure consisting of a tandem alkene insertion-Suzuki coupling reaction followed by a DDQ dehydrogenation, we have been able to synthesize derivatives with a wide variety of substituents. We also present the results of UV-visible spectroscopy studies and kinetics experiments that show the effect of substituent on light absorption properties of the norbornadienes as well as the kinetic stability of the quadricyclanes that result from their photochemical conversion. While substitution on the aromatic rings had comparatively little effect on quadricyclane lability, substitution at a bridgehead position with a methyl group produced a quadricyclane that thermally reverted to the norbornadiene at a rate that was significantly slower than that for the quadricyclane without the methyl substituent. From the results of the kinetics experiments, we determined that the reversion of the quadricyclanes occurs via a free radical mechanism with very little contribution from polar effects. This observation led us to speculate as to whether our data may form the basis for a free radical substituent constant, σQ•, analogous to the traditional Hammett σ parameter.

  9. Effects of La-Zn substitution on microstructure and magnetic properties of strontium ferrite nanofibers

    NASA Astrophysics Data System (ADS)

    Shen, Xiangqian; Liu, Mingquan; Song, Fuzhan; Zhu, Yongwei

    2011-07-01

    Sr1- x La x Zn x Fe12- x O19/poly(vinylpyrrolidone) (PVP) (0.0≤ x≤0.5) precursor nanofibers were prepared by the sol-gel assisted electrospinning method from starting reagents of metal salts and PVP. Subsequently, the Sr1- x La x Zn x Fe12- x O19 nanofibers with diameters of around 100 nm were obtained by calcination of the precursor at 800 to 1000°C for 2 h. The precursor and resultant Sr1- x La x Zn x Fe12- x O19 nanofibers were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometer and vibrating sample magnetometer. The grain sizes of Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers are in a nanoscale from 40 to 48 nm corresponding to the calcination temperature from 800 to 1000°C. With La-Zn substitution content increase from 0 to 0.5, the grain size and lattice constants for the Sr1- x La x Zn x Fe12- x O19 nanofibers obtained at 900°C show a steady reduction trend. With variations of the ferrite particle size arising from the La-Zn substitution, the nanofiber morphology changes from the necklace-like structure linking by single elongated plate-like particles to the structure building of multi-particles on the nanofiber cross-section. The specific saturation magnetization of Sr1- x La x Zn x Fe12- x O19 nanofibers initially increases with the La-Zn content, reaching a maximum value 72 A m2 kg-1 at x=0.2, and then decreases with a further La-Zn content increase up to x=0.5, while the coercivity exhibits a continuous reduction from 413 ( x=0) to 219 kA m-1 ( x=0.5). The mechanism for the La-Zn substitution and the nanofiber magnetic property are analyzed.

  10. What Is a Recessive Allele?

    ERIC Educational Resources Information Center

    American Biology Teacher, 1991

    1991-01-01

    Presents four misconceptions students have concerning the concepts of recessive and dominant alleles. Discusses the spectrum of dominant-recessive relationships, different levels of analysis between phenotype and genotype, possible causes of dominance, and an example involving wrinkled peas. (MDH)

  11. Comprehensive analysis of imprinted genes in maize reveals allelic variation for imprinting and limited conservation with other species.

    PubMed

    Waters, Amanda J; Bilinski, Paul; Eichten, Steven R; Vaughn, Matthew W; Ross-Ibarra, Jeffrey; Gehring, Mary; Springer, Nathan M

    2013-11-26

    In plants, a subset of genes exhibit imprinting in endosperm tissue such that expression is primarily from the maternal or paternal allele. Imprinting may arise as a consequence of mechanisms for silencing of transposons during reproduction, and in some cases imprinted expression of particular genes may provide a selective advantage such that it is conserved across species. Separate mechanisms for the origin of imprinted expression patterns and maintenance of these patterns may result in substantial variation in the targets of imprinting in different species. Here we present deep sequencing of RNAs isolated from reciprocal crosses of four diverse maize genotypes, providing a comprehensive analysis that allows evaluation of imprinting at more than 95% of endosperm-expressed genes. We find that over 500 genes exhibit statistically significant parent-of-origin effects in maize endosperm tissue, but focused our analyses on a subset of these genes that had >90% expression from the maternal allele (69 genes) or from the paternal allele (108 genes) in at least one reciprocal cross. Over 10% of imprinted genes show evidence of allelic variation for imprinting. A comparison of imprinting in maize and rice reveals that 13% of genes with syntenic orthologs in both species exhibit conserved imprinting. Genes that exhibit conserved imprinting between maize and rice have elevated nonsynonymous to synonymous substitution ratios compared with other imprinted genes, suggesting a history of more rapid evolution. Together, these data suggest that imprinting only has functional relevance at a subset of loci that currently exhibit imprinting in maize.

  12. A novel HLA-B*40 allele, B*40:01:40, identified in a Chinese individual.

    PubMed

    Pei, Y F; Huang, H N; Li, H C; Shen, W D

    A new allele, officially named B*40:01:40, was detected in a Chinese individual by sequence-based typing (SBT). The new allele differs from B*40:01:01 by a single nucleotide exchange at position 99 in codon 9, which results in synonymous substitution and seems not to compromise the HLA complex and T-cell receptor interaction.

  13. Effects of 2-substituted-4-phenylquinolines on uptake of serotonin and norepinephrine by isolated brain synaptosomes

    SciTech Connect

    Alhaider, A.A.; Lein, E.J.; Ransom, R.W.; Bolger, M.B.

    1987-03-02

    In this present communication, the in vitro inhibition of the uptake of (/sup 3/H)-L-norepinephrine ((/sup 3/H) NE) and (/sup 3/H)-Serotonin ((/sup 3/H) 5-HT) by eleven synthesized 2-substituted-4-phenylquionlines were studied using rate brain synaptosomal preparations. Compounds with an open side chain were relatively weak inhibitors of the synaptosomal uptake of (/sup 3/H) NE and (/sup 3/H) 5HT. Compounds having a distance of three atoms between the terminal basic nitrogen of the side chain and the quinoline ring were better inhibitors of serotonin uptake than those compounds having a four-atom distance. The replacement of the side chain with a piperazine ring produced compounds which were more potent and selective inhibitors of the uptake of either (/sup 3/H) 5-HT or (/sup 3/H) NE. Further structure-activity relationships are also discussed. 13 references, 1 table.

  14. Pressure effect on structural and vibrational properties of Y-substituted BiFeO3

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Jie; Qin, Zhen-Xing; Chen, Xiao-Kun; Zhang, Jing; Liu, Jing; Wu, Zhigang; Chen, Xiao-Jia

    2013-09-01

    The structural and vibrational properties of 5% Y-substituted BiFeO3 under pressure have been investigated using synchrotron x-ray diffraction (SXRD) and Raman scattering measurements. At a pressure below 30.3 GPa, distinct changes in the Raman spectra and SRXD pattern show evidence for one pressure-induced structural transition from the polar rhombohedral R3c phase to the nonpolar orthorhombic Pnma phase commencing at 3.6 and completed at 7.2 GPa, where there is a region of phase coexistence between the R3c and Pnma phases. At a higher pressure of 40.8 GPa, another phase transition from orthorhombic to cubic is observed accompanied by the insulator-metal transition. Our data do not suggest the pressure-induced re-entrance of ferroelectricity in the model multiferroic Bi0.95Fe0.05O3 in the pressure range studied.

  15. Pressure effect on structural and vibrational properties of Y-substituted BiFeO3.

    PubMed

    Wu, Yu-Jie; Qin, Zhen-Xing; Chen, Xiao-Kun; Zhang, Jing; Liu, Jing; Wu, Zhigang; Chen, Xiao-Jia

    2013-09-11

    The structural and vibrational properties of 5% Y-substituted BiFeO3 under pressure have been investigated using synchrotron x-ray diffraction (SXRD) and Raman scattering measurements. At a pressure below 30.3 GPa, distinct changes in the Raman spectra and SRXD pattern show evidence for one pressure-induced structural transition from the polar rhombohedral R3c phase to the nonpolar orthorhombic Pnma phase commencing at 3.6 and completed at 7.2 GPa, where there is a region of phase coexistence between the R3c and Pnma phases. At a higher pressure of 40.8 GPa, another phase transition from orthorhombic to cubic is observed accompanied by the insulator-metal transition. Our data do not suggest the pressure-induced re-entrance of ferroelectricity in the model multiferroic Bi0.95Fe0.05O3 in the pressure range studied.

  16. Effect of substitutional defects on Kambersky damping in L1{sub 0} magnetic materials

    SciTech Connect

    Qu, T.; Victora, R. H.

    2015-02-16

    Kambersky damping, representing the loss of magnetic energy from the electrons to the lattice through the spin orbit interaction, is calculated for L1{sub 0} FePt, FePd, CoPt, and CoPd alloys versus chemical degree of order. When more substitutional defects exist in the alloys, damping is predicted to increase due to the increase of the spin-flip channels allowed by the broken symmetry. It is demonstrated that this corresponds to an enhanced density of states (DOS) at the Fermi level, owing to the rounding of the DOS with loss of long-range order. Both the damping and the DOS of the Co-based alloy are found to be less affected by the disorder. Pd-based alloys are predicted to have lower damping than Pt-based alloys, making them more suitable for high density spintronic applications.

  17. Effect of amino substitution on the excited state dynamics of uracil.

    PubMed

    Bányász, Akos; Gustavsson, Thomas; Keszei, Erno; Improta, Roberto; Markovitsi, Dimitra

    2008-07-01

    The excited state deactivation of two amino-substituted uracils, 5-aminouracil (5AU) and 6-aminouracil (6AU) in aqueous solution was studied by femtosecond fluorescence upconversion. The fluorescence of 6AU decays as fast as that of uracil with a unique time constant of about 100 femtoseconds. The fluorescence of 5AU exhibits a more complex behavior, fundamentally different from what we found in any other uracils: the decays are globally slower (up to several picoseconds) and depend strongly on the wavelength. This difference is attributed to the particular character of the amino group, affecting the out-of-plane motion of the 5-substituent which has been shown to be crucial for the ultrafast internal conversion occurring in uracils. Our observations indicate instead the formation of a transient fluorescent state which in turn is deactivated by a different relaxation process specific to the amino group.

  18. Effect of substitutional defects on Kambersky damping in L10 magnetic materials

    NASA Astrophysics Data System (ADS)

    Qu, T.; Victora, R. H.

    2015-02-01

    Kambersky damping, representing the loss of magnetic energy from the electrons to the lattice through the spin orbit interaction, is calculated for L10 FePt, FePd, CoPt, and CoPd alloys versus chemical degree of order. When more substitutional defects exist in the alloys, damping is predicted to increase due to the increase of the spin-flip channels allowed by the broken symmetry. It is demonstrated that this corresponds to an enhanced density of states (DOS) at the Fermi level, owing to the rounding of the DOS with loss of long-range order. Both the damping and the DOS of the Co-based alloy are found to be less affected by the disorder. Pd-based alloys are predicted to have lower damping than Pt-based alloys, making them more suitable for high density spintronic applications.

  19. Choreography of Ig allelic exclusion.

    PubMed

    Cedar, Howard; Bergman, Yehudit

    2008-06-01

    Allelic exclusion guarantees that each B or T cell only produces a single antigen receptor, and in this way contributes to immune diversity. This process is actually initiated in the early embryo when the immune receptor loci become asynchronously replicating in a stochastic manner with one early and one late allele in each cell. This distinct differential replication timing feature then serves an instructive mark that directs a series of allele-specific epigenetic events in the immune system, including programmed histone modification, nuclear localization and DNA demethylation that ultimately bring about preferred rearrangement on a single allele, and this decision is temporally stabilized by feedback mechanisms that inhibit recombination on the second allele. In principle, these same molecular components are also used for controlling monoallelic expression at other genomic loci, such as those carrying interleukins and olfactory receptor genes that require the choice of one gene out of a large array. Thus, allelic exclusion appears to represent a general epigenetic phenomenon that is modeled on the same basis as X chromosome inactivation.

  20. Effect of Heteroatom Substitution on Transport in Alkanedithiol-Based Molecular Tunnel Junctions: Evidence for Universal Behavior.

    PubMed

    Xie, Zuoti; Bâldea, Ioan; Oram, Stuart; Smith, Christopher E; Frisbie, C Daniel

    2017-01-24

    The transport properties of molecular junctions based on alkanedithiols with three different methylene chain lengths were compared with junctions based on similar chains wherein every third -CH2- was replaced with O or S, that is, following the general formula HS(CH2CH2X)nCH2CH2SH, where X = CH2, O, or S and n = 1, 2, or 3. Conducting probe atomic force microscopy revealed that the low bias resistance of the chains increased upon substitution in the order CH2 < O < S. This change in resistance is ascribed to the observed identical trend in contact resistance, Rc, whereas the exponential prefactor β (length sensitivity) was essentially the same for all chains. Using an established, analytical single-level model, we computed the effective energy offset εh (i.e., Fermi level relative to the effective HOMO level) and the electronic coupling strength Γ from the current-voltage (I-V) data. The εh values were only weakly affected by heteroatom substitution, whereas the interface coupling strength Γ varied by over an order of magnitude. Consequently, we ascribe the strong variation in Rc to the systematic change in Γ. Quantum chemical calculations reveal that the HOMO density shifts from the terminal SH groups for the alkanedithiols to the heteroatoms in the substituted chains, which provides a plausible explanation for the marked decrease in Γ for the dithiols with electron-rich heteroatoms. The results indicate that the electronic coupling and thus the resistance of alkanedithiols can be tuned by substitution of even a single atom in the middle of the molecule. Importantly, when appropriately normalized, the experimental I-V curves were accurately simulated over the full bias range (±1.5 V) using the single-level model with no adjustable parameters. The data could be collapsed to a single universal curve predicted by the model, providing clear evidence that the essential physics is captured by this analytical approach and supporting its utility for molecular

  1. Isomer and Fluorination Effects among Fluorine Substituted Hydrocarbon C3/C4 Molecules in Electron Impact Ionization

    NASA Astrophysics Data System (ADS)

    Patel, U. R.; Joshipura, K. N.

    2015-05-01

    Electron collision processes are very important in both man-made and natural plasmas, for determining the energy balances and transport properties of electrons. Electron -molecule scattering leading to ionization represents one of the most fundamental processes in collision physics. In the gas phase, the total efficiency of the process is described by the absolute total electron impact ionization cross section. Carbon based materials are some of the widely used materials for a divertor plate and magnetically confined fusion devices. In the ``ITER,'' it is very important for steady state operation to have an estimate of the lifetime of carbon plasma facing components. Apart from fusion plasma relevance, the present theoretical study is very important in modeling and controlling other electron assisted processes in many areas. Hydrocarbons play an important role for plasma diagnostics as impurities in the Tokamak fusion divertor, as seed gases for the production of radicals and ions in low temperature plasma processing. Fluorine substituted hydrocarbons (perfluorocarbons) are important as reactants in plasma assisted fabrication processes. In the present work, we have calculated total ionization cross sections Qion for C3/C4 Hydrocarbon isomers by electron impact, and comparisons are made mutually to observe isomer effect. Comparisons are also made by substituting H atom by F atom and revealing fluorination effect. The present calculations are quite significant owing to the lack of experimental data, with just an isolated previous theoretical work in some cases.

  2. Effects of Ge substitution on the structural and physical properties of CuFeO2 delafossite oxide

    NASA Astrophysics Data System (ADS)

    Naka-in, Lerdkead; Kamwanna, Teerasak; Srepusharawoot, Pornjuk; Pinitsoontorn, Supree; Amornkitbamrung, Vittaya

    2015-04-01

    Delafossite CuFe1-xGexO2 (0.0 ≤ x ≤ 0.1) semiconductors were synthesized by solid-state reaction. The effects of Ge concentration on microstructural, optical, magnetic and electrical properties were investigated. X-ray diffraction (XRD) analysis results reveal the delafossite structure of all the samples. The lattice spacing of CuFe1-xGexO2 decreased with increasing substitution of Ge at the Fe site. The optical properties measured at room temperature by UV-visible spectroscopy showed an absorption peak at 283 nm (4.38 eV). The corresponding direct optical band gap was found to decrease with increasing Ge content (from 3.69 eV for x = 0 to 3.61 eV for x = 0.10), exhibiting transparency in the visible region. The magnetic hysteresis loops measured at room temperature showed that the Ge-doped CuFeO2 samples exhibit ferromagnetic behavior. The Curie temperature suggests that ferromagnetism originates from CuFe1-xGexO2 matrices. The substitution of Fe3+ by Ge4+ produces a mixed effect on the magnetic properties of CuFeO2 delafossite oxide. The resistivity of CuFe0.99Ge0.01O2 was observed to be ˜0.1 Ω·cm at room temperature.

  3. Combined effects of Sr substitution and pressure on the ground states in CaFe2As2

    NASA Astrophysics Data System (ADS)

    Knöner, S.; Gati, E.; Köhler, S.; Wolf, B.; Tutsch, U.; Ran, S.; Torikachvili, M. S.; Bud'ko, S. L.; Canfield, P. C.; Lang, M.

    2016-10-01

    We present a detailed study of the combined effects of Sr substitution and hydrostatic pressure on the ground-state properties of CaFe2As2 . Measurements of the electrical resistance and magnetic susceptibility, both at ambient and finite pressure P ≤2 GPa, were performed on Ca1 -xSrxFe2As2 single crystals grown out of Sn flux. We find that by Sr substitution the transition temperature to the magnetic/structural phase is enhanced and therefore a higher pressure is needed to suppress the transition to lowest temperature. In addition, the transition to the collapsed tetragonal phase is found at a pressure, which is distinctly higher than in the pure compound. This implies that the stability ranges of both phases shift on the pressure-axis upon doping, but the latter one with a higher rate. These observations suggest the possibility of separating the two phase lines, which intersect already at elevated temperatures for x =0 and low Sr concentration levels. For x =0.177 , we find strong evidence that both phases remain separated down to the lowest temperature and that a zero-resistance state emerges in this intermediate pressure window. This observation indicates that Sr substitution combined with hydrostatic pressure provides another route for stabilizing superconductivity in CaFe2As2 . Our results are consistent with the notion that (i) preserving the fluctuations associated with the structural-magnetic transition to low temperatures is vital for superconductivity to form in this material and that (ii) the nonmagnetic collapsed tetragonal phase is detrimental for superconductivity.

  4. Combined effects of Sr substitution and pressure on the ground states in CaFe2As2

    DOE PAGES

    Knoner, S.; Gati, E.; Kohler, S.; ...

    2016-10-21

    Here, we present a detailed study of the combined effects of Sr substitution and hydrostatic pressure on the ground-state properties of CaFe2As2. Measurements of the electrical resistance and magnetic susceptibility, both at ambient and finite pressure P ≤ 2 GPa, were performed on Ca1–xSrxFe2As2 single crystals grown out of Sn flux. We find that by Sr substitution the transition temperature to the magnetic/structural phase is enhanced and therefore a higher pressure is needed to suppress the transition to lowest temperature. In addition, the transition to the collapsed tetragonal phase is found at a pressure, which is distinctly higher than inmore » the pure compound. This implies that the stability ranges of both phases shift on the pressure-axis upon doping, but the latter one with a higher rate. These observations suggest the possibility of separating the two phase lines, which intersect already at elevated temperatures for x = 0 and low Sr concentration levels. For x = 0.177, we find strong evidence that both phases remain separated down to the lowest temperature and that a zero-resistance state emerges in this intermediate pressure window. This observation indicates that Sr substitution combined with hydrostatic pressure provides another route for stabilizing superconductivity in CaFe2As2. Lastly, our results are consistent with the notion that (i) preserving the fluctuations associated with the structural-magnetic transition to low temperatures is vital for superconductivity to form in this material and that (ii) the nonmagnetic collapsed tetragonal phase is detrimental for superconductivity.« less

  5. Multimer Formation Explains Allelic Suppression of PRDM9 Recombination Hotspots

    PubMed Central

    Baker, Christopher L.; Petkova, Pavlina; Walker, Michael; Flachs, Petr; Mihola, Ondrej; Trachtulec, Zdenek; Petkov, Petko M.; Paigen, Kenneth

    2015-01-01

    Genetic recombination during meiosis functions to increase genetic diversity, promotes elimination of deleterious alleles, and helps assure proper segregation of chromatids. Mammalian recombination events are concentrated at specialized sites, termed hotspots, whose locations are determined by PRDM9, a zinc finger DNA-binding histone methyltransferase. Prdm9 is highly polymorphic with most alleles activating their own set of hotspots. In populations exhibiting high frequencies of heterozygosity, questions remain about the influences different alleles have in heterozygous individuals where the two variant forms of PRDM9 typically do not activate equivalent populations of hotspots. We now find that, in addition to activating its own hotspots, the presence of one Prdm9 allele can modify the activity of hotspots activated by the other allele. PRDM9 function is also dosage sensitive; Prdm9 +/- heterozygous null mice have reduced numbers and less active hotspots and increased numbers of aberrant germ cells. In mice carrying two Prdm9 alleles, there is allelic competition; the stronger Prdm9 allele can partially or entirely suppress chromatin modification and recombination at hotspots of the weaker allele. In cell cultures, PRDM9 protein variants form functional heteromeric complexes which can bind hotspots sequences. When a heteromeric complex binds at a hotspot of one PRDM9 variant, the other PRDM9 variant, which would otherwise not bind, can still methylate hotspot nucleosomes. We propose that in heterozygous individuals the underlying molecular mechanism of allelic suppression results from formation of PRDM9 heteromers, where the DNA binding activity of one protein variant dominantly directs recombination initiation towards its own hotspots, effectively titrating down recombination by the other protein variant. In natural populations with many heterozygous individuals, allelic competition will influence the recombination landscape. PMID:26368021

  6. Multimer Formation Explains Allelic Suppression of PRDM9 Recombination Hotspots.

    PubMed

    Baker, Christopher L; Petkova, Pavlina; Walker, Michael; Flachs, Petr; Mihola, Ondrej; Trachtulec, Zdenek; Petkov, Petko M; Paigen, Kenneth

    2015-09-01

    Genetic recombination during meiosis functions to increase genetic diversity, promotes elimination of deleterious alleles, and helps assure proper segregation of chromatids. Mammalian recombination events are concentrated at specialized sites, termed hotspots, whose locations are determined by PRDM9, a zinc finger DNA-binding histone methyltransferase. Prdm9 is highly polymorphic with most alleles activating their own set of hotspots. In populations exhibiting high frequencies of heterozygosity, questions remain about the influences different alleles have in heterozygous individuals where the two variant forms of PRDM9 typically do not activate equivalent populations of hotspots. We now find that, in addition to activating its own hotspots, the presence of one Prdm9 allele can modify the activity of hotspots activated by the other allele. PRDM9 function is also dosage sensitive; Prdm9+/- heterozygous null mice have reduced numbers and less active hotspots and increased numbers of aberrant germ cells. In mice carrying two Prdm9 alleles, there is allelic competition; the stronger Prdm9 allele can partially or entirely suppress chromatin modification and recombination at hotspots of the weaker allele. In cell cultures, PRDM9 protein variants form functional heteromeric complexes which can bind hotspots sequences. When a heteromeric complex binds at a hotspot of one PRDM9 variant, the other PRDM9 variant, which would otherwise not bind, can still methylate hotspot nucleosomes. We propose that in heterozygous individuals the underlying molecular mechanism of allelic suppression results from formation of PRDM9 heteromers, where the DNA binding activity of one protein variant dominantly directs recombination initiation towards its own hotspots, effectively titrating down recombination by the other protein variant. In natural populations with many heterozygous individuals, allelic competition will influence the recombination landscape.

  7. Association of BoLA-DRB3.2 alleles with tick (Boophilus microplus) resistance in cattle.

    PubMed

    Martinez, M L; Machado, M A; Nascimento, C S; Silva, M V G B; Teodoro, R L; Furlong, J; Prata, M C A; Campos, A L; Guimarães, M F M; Azevedo, A L S; Pires, M F A; Verneque, R S

    2006-08-31

    Losses caused by bovine tick burdens in tropical countries have a tremendous economic impact on production systems. Besides reducing production, this parasite can cause death in the most susceptible animals. The use of commercial acaricides has been the major method of control, but their misuse has led to tick resistance to many chemicals. More recently, vaccines have been used in some countries without solving the problem completely. An alternative could be the development of resistant animals and the use of genetic markers and candidate genes that could help with the enormous task of selecting resistant animals. The bovine lymphocyte antigen genes (BoLA) have been shown to be associated with some parasitic infestations and disease incidence. Thus, the objective of the present study was to determine the association of BoLA-DRB3.2 alleles with tick resistance in cattle. The study was conducted on 231 F2 (Gyr x Holstein) animals that were artificially infested with 10,000 tick larvae. Log of tick count +1 was used as the dependent variable in a mixed animal model with allele substitution effects in addition to fixed effects of year and season at tick count, sex of calves, age of animal at tick count, hair type (short-straight, short-curl, long-straight, and long-curl), coat color (white, >75% white, 50- 75% white, and 25-50% white), and additive genetic, permanent environmental and residual effects as random. Females showed fewer ticks than males. Animals with short-straight hair were more resistant to tick infestation than animals with long-curl hair, and animals with whiter coat color also had fewer ticks. An association between BoLA alleles and lower tick number was found for alleles DRB3.2 *18, *20 and *27 at the 5% significance level. Also, one allele (DRB3.2*16) showed an association at the 10% level. Allele *27 was the most frequent in the population (30.7%), followed by alleles *16 (10.8%), *20 (8.7%) and *18 (2.4%). These results suggest that BoLA-DRB3

  8. Biased gene conversion skews allele frequencies in human populations, increasing the disease burden of recessive alleles.

    PubMed

    Lachance, Joseph; Tishkoff, Sarah A

    2014-10-02

    Gene conversion results in the nonreciprocal transfer of genetic information between two recombining sequences, and there is evidence that this process is biased toward G and C alleles. However, the strength of GC-biased gene conversion (gBGC) in human populations and its effects on hereditary disease have yet to be assessed on a genomic scale. Using high-coverage whole-genome sequences of African hunter-gatherers, agricultural populations, and primate outgroups, we quantified the effects of GC-biased gene conversion on population genomic data sets. We find that genetic distances (FST and population branch statistics) are modified by gBGC. In addition, the site frequency spectrum is left-shifted when ancestral alleles are favored by gBGC and right-shifted when derived alleles are favored by gBGC. Allele frequency shifts due to gBGC mimic the effects of natural selection. As expected, these effects are strongest in high-recombination regions of the human genome. By comparing the relative rates of fixation of unbiased and biased sites, the strength of gene conversion was estimated to be on the order of Nb ≈ 0.05 to 0.09. We also find that derived alleles favored by gBGC are much more likely to be homozygous than derived alleles at unbiased SNPs (+42.2% to 62.8%). This results in a curse of the converted, whereby gBGC causes substantial increases in hereditary disease risks. Taken together, our findings reveal that GC-biased gene conversion has important population genetic and public health implications.

  9. Synthesis, photophysical, and electrochemical properties of wide band gap tetraphenylsilane-carbazole derivatives: Effect of the substitution position and naphthalene side chain

    NASA Astrophysics Data System (ADS)

    Ho, Kar Wei; Ariffin, A.

    2016-12-01

    Four tetraphenylsilane-carbazole derivatives with wide bandgaps (3.38-3.55 eV) were synthesized. The effects of the substitution position and of the presence of naphthalene groups on the photophysical, electrochemical and thermal properties were investigated. The derivatives exhibited maximum absorption peaks ranging from 293 to 304 nm and maximum emission peaks ranging from 347 to 386 nm. Changing the carbazole substitution position on the tetraphenylsilane did not significantly change the photophysical and electrochemical properties. However, p-substituted compounds exhibited higher glass transition temperatures than m-substituted compounds. Naphthalene groups with bulky structures had extended the conjugation lengths that red-shifted both the absorption and emission spectra. The LUMO level was decreased, which reduced the optical bandgap and triplet energy level. However, the naphthalene groups significantly improved the thermal stability by increasing the glass transition temperature of the compounds.

  10. Effect of Nickel Substitution on Defect Chemistry, Electrical Properties, and Dimensional Stability of Calcium-Doped Yttrium Chromite

    SciTech Connect

    Yoon, Kyung J.; Stevenson, Jeffry W.; Marina, Olga A.

    2011-06-30

    The effect of nickel substitution on defect chemistry, electrical properties, and dimensional stability of calcium-doped yttrium chromite was studied for use as an interconnect material in high temperature solid oxide fuel cells (SOFCs). The compositions of Y0.8Ca0.2Cr1-xNixO3±δ (x=0-0.15), prepared using the glycine nitrate process, showed single phase orthorhombic perovskite structures over a wide range of oxygen partial pressures (10^-17 atm ≤ pO2 ≤ 0.21 atm). X-ray diffraction (XRD) analysis indicated that most of the nickel ions replacing chromium ions are divalent and act as acceptor dopants, leading to a substantial increase in conductivity. In particular, the conductivity at 900 degree C in air increased from 10 S/cm to 34 S/cm with 15% nickel substitution, and an increase in charge carrier density was confirmed by Seebeck measurements. A point defect model was derived, and the relationship between electrical conductivity and oxygen partial pressure was successfully fitted into the proposed model. The defect modeling results indicated that nickel substitution improves the stability of calcium-doped yttrium chromite toward reduction and suppresses the oxygen vacancy formation, which results in significantly increased electrical conductivity in reducing environment. The electrical conductivity of Y0.8Ca0.2Cr0.85Ni0.15O3±δ at 900 degree C in reducing atmosphere (pO2=10^-17 atm) was 5.8 S/cm, which was more than an order of magnitude higher than that of Y0.8Ca0.2CrO3±δ (0.2 S/cm). Improved stability in reducing atmosphere was further confirmed by dilatometry measurements showing reduced isothermal "chemical" expansion, and the isothermal expansion in reducing atmosphere (pO2=10^-17 atm) at 900 degree C decreased from 0.07% for Y0.8Ca0.2CrO3±δ to 0.03% for Y0.8Ca0.2Cr0.85Ni0.15O3±δ. Based on these results, enhanced electrical performance and mechanical integrity is expected with nickel substitution on calcium-doped yttrium chromite in SOFC

  11. Large-scale profiling and identification of potential regulatory mechanisms for allelic gene expression in colorectal cancer cells.

    PubMed

    Lee, Robin Dong-Woo; Song, Min-Young; Lee, Jong-Keuk

    2013-01-01

    Allelic variation in gene expression is common in humans and this variation is associated with phenotypic variation. In this study, we employed high-density single nucleotide polymorphism (SNP) chips containing 13,900 exonic SNPs to identify genes with allelic gene expression in cells from colorectal cancer cell lines. We found 2 monoallelically expressed genes (ERAP2 and MYLK4), 32 genes with an allelic imbalance in their expression, and 13 genes showing allele substitution by RNA editing. Among a total of 34 allelically expressed genes in colorectal cancer cells, 15 genes (44.1%) were associated with cis-acting eQTL, indicating that large portions of allelically expressed genes are regulated by cis-acting mechanisms of gene expression. In addition, potential regulatory variants present in the proximal promoter regions of genes showing either monoallelic expression or allelic imbalance were not tightly linked with coding SNPs, which were detected with allelic gene expression. These results suggest that multiple rare variants could be involved in the cis-acting regulatory mechanism of allelic gene expression. In the comparison with allelic gene expression data from Centre d'Etude du Polymorphisme Humain (CEPH) family B cells, 12 genes showed B-cell specific allelic imbalance and 1 noncoding SNP showed colorectal cancer cell-specific allelic imbalance. In addition, different patterns of allele substitution were observed between B cells and colorectal cancer cells. Overall, our study not only indicates that allelic gene expression is common in colorectal cancer cells, but our study also provides a better understanding of allele-specific gene expression in colorectal cancer cells.

  12. The effect of Cu substitution on microstructure and thermoelectric properties of LaCoO3 ceramics.

    PubMed

    Li, Fu; Li, Jing-Feng; Li, Jian-Hui; Yao, Fang-Zhou

    2012-09-21

    La(Co, Cu)O(3-δ) ceramics were prepared by pressureless sintering of citrate precursor powders, and their thermoelectric properties were investigated with an emphasis on the influence of Cu doping and phase structure as well as microstructure. It was found that a secondary phase first appeared in the form of a network along the grain boundaries and then changed to dispersion with increasing Cu content, which effectively reduced the lattice thermal conductivity of the materials. The thermal conductivity was only 1.21 W m(-1) K(-1) for the sample LaCo(0.75)Cu(0.25)O(3-δ), being much lower as for the thermoelectric oxide materials. In addition, a small amount of Cu substitution for Co increased the electrical conductivity greatly and the absolute Seebeck coefficient, whose sign was also reversed from negative to positive. The dimensionless figure of merit, ZT, of LaCoO(3-δ) oxides at low and middle temperatures can be remarkably enhanced by substituting Co with Cu.

  13. Indium-substitution and indium-less case effects on structural and magnetic properties of yttrium-iron garnet

    NASA Astrophysics Data System (ADS)

    Nazlan, Rodziah; Hashim, Mansor; Ibrahim, Idza Riati; Idris, Fadzidah Mohd; Ismail, Ismayadi; Ab Rahman, Wan Norailiana Wan; Abdullah, Nor Hapishah; Zulkimi, Muhammad Misbah Muhammad; Mustaffa, Muhammad Syazwan

    2015-10-01

    The effect of indium (In) substitution in the dynamics of structure and ferrimagnetism of yttrium iron garnet (YIG) employing sintering temperature as a temporary agent of composition and structural changes was reported in this study. The nanoparticles of YIG powder samples with various In content (x=0.0-0.4) were prepared via the mechanical alloying (MA) technique. A brief, yet revealing characterization of the samples was carried out via transmission electron microscope, X-ray diffraction, Raman spectroscopy, B-H Hysteresisgraph, and LCR-metre. The X-ray diffraction analysis of the samples prepared via the MA indicates the formation of single phase YIG structure at much lower sintering temperature than that in the conventional ceramic technique. The lattice constant increases as In content increases which obeys Vegard's Law due to the larger In3+ ions replacing the smaller Fe3+ ions. The saturation induction increased reaching about 699.1 G for x=0.3 and decreased with further In substitution. Three stages of ordered magnetism formation were identified which attributed to development of crystallinity and larger grains for magnetic domain accommodation. The Curie temperature shows a decrement in their values with In content due to weakening of superexchange interactions. Raman shifts from 268.1 to 272.2 cm-1 with increasing In content were observed due to stress developed in the YIG crystal structure.

  14. Effect of co substitution of Mg and Zn on electromagnetic properties of NiCuZn ferrites

    NASA Astrophysics Data System (ADS)

    Sujatha, Ch.; Reddy, K. Venugopal; Babu, K. Sowri; Reddy, A. Rama Chandra; Suresh, M. Buchi; Rao, K. H.

    2013-07-01

    Ni0.5-2xMgxCu0.05Zn0.45+xFe2O4 (x=0, 0.04, 0.08, 0.12, and 0.16) ferrite samples were prepared through sol-gel method using polyvinyl alcohol as a chelating agent. Structural, magnetic, dielectric and electrical properties of the sintered samples were investigated using the characterisation techniques such as X-ray Diffractometer, Vibration sample magnetometer and impedance analyser respectively. X-ray diffraction patterns confirmed the formation of single phase cubic spinel structure of the samples. FTIR spectra showed two prominent bands (400 cm-1 and 600 cm-1) corresponding to characteristic of ferrites. Substitution of Mg and Zn for Ni showed gradual decrease of both magnetisation and coercivity. Magnetic permeability showed increasing trend with composition due to low anisotropy constant of Mg and Zn compared to Ni. Dielectric properties of the samples showed that both the dielectric constant as well as the dielectric loss factor was decreased with the composition. Cole-Cole plots consist of distorted semicircle with increasing diameter as a function of composition indicating improved resistance of the samples. The effect of substitution of Mg and Zn for Ni in NiCuZn ferrite system resulted in improved permeability with high cut off frequency, reduced dielectric losses and enhanced resistance of the samples.

  15. Effect of 60Co gamma irradiation on dielectric and complex impedance properties of Dy3+ substituted Ni-Zn nanoferrites

    NASA Astrophysics Data System (ADS)

    Veena, M.; Somashekarappa, A.; Shankaramurthy, G. J.; Jayanna, H. S.; Somashekarappa, H. M.

    2016-12-01

    Nanocrystalline Ni1-xZnxFe2-yDyyO4 (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0.0 and 0.1) ferrites were synthesized by combustion method. Ni-Zn-Dy nanoferrites were investigated by X-ray diffraction, scanning electron microscopy, dielectric and impedance properties, before and after γ-irradiation process by 60Co γ-radiation with a dose rate of 310 kGy. The lattice parameter of irradiated samples increased attributed to the conversion of smaller size Fe3+ ions to larger size Fe2+ ions on ionizing effect of gamma radiation. Experimental results reveal that reduction in dielectric constant (ε‧), loss tangent (tan δ), real (Z‧) and imaginary (Z‧‧) impedance and increase in ac conductivity (σac) have been increased with increasing in frequency. It was found that ε‧, tan δ, σac increase, Z‧‧ and Z‧‧ reach a maximum value and thereafter decrease with further Zn ion substitution. The values of ε‧, tan δ and σac decrease with Dy3+ substitution and enhanced after irradiation. The complex impedance analysis suggesting predominant contribution to conduction was through the grain boundary.

  16. Photodegradation of malachite green dye catalyzed by Keggin-type polyoxometalates under visible-light irradiation: Transition metal substituted effects

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Guang; Zheng, Ting; Liu, Shuang; Zhang, Han-Yu

    2016-04-01

    In the present paper, Keggin-type polyoxometalates (POMs) (NH4)3[PW12O40] and its mono-transition-metal-substituted species (NH4)5[{PW11O39}MII(H2O)] (M = Mn, Fe, Co, Ni, Cu, Zn) have been synthesized and used as photocatalyst to activate O2 for the degradation of dye molecule under visible-light irradiation. Because of the strong adsorption on the surface of POM catalyst, malachite green (MG) molecule was employed as a molecular probe to test their photocatalytic activity. The photodegradation study shows that introduction of transition metal ion leads to an increase in the degradation of MG in the following order: Mn < Fe < Co < [PW12O40]3- < Ni < Cu < Zn, which indicates that the photocatalytic activity of these POMs is sensitive to the transition metal substituted effects. Electronic structure analysis based on the density functional theory calculations shows that a moderate decrease of oxidizing ability of POM catalyst may improve the photocatalytic activity in the degradation of dye molecule under visible-light irradiation. Meanwhile, intermediate products about the photocatalytic oxidation of MG molecule were proposed on the basis of gas chromatograph mass spectrometer analysis.

  17. Allelic polymorphism of GIGANTEA is responsible for naturally occurring variation in circadian period in Brassica rapa.

    PubMed

    Xie, Qiguang; Lou, Ping; Hermand, Victor; Aman, Rashid; Park, Hee Jin; Yun, Dae-Jin; Kim, Woe Yeon; Salmela, Matti Juhani; Ewers, Brent E; Weinig, Cynthia; Khan, Sarah L; Schaible, D Loring P; McClung, C Robertson

    2015-03-24

    GIGANTEA (GI) was originally identified by a late-flowering mutant in Arabidopsis, but subsequently has been shown to act in circadian period determination, light inhibition of hypocotyl elongation, and responses to multiple abiotic stresses, including tolerance to high salt and cold (freezing) temperature. Genetic mapping and analysis of families of heterogeneous inbred lines showed that natural variation in GI is responsible for a major quantitative trait locus in circadian period in Brassica rapa. We confirmed this conclusion by transgenic rescue of an Arabidopsis gi-201 loss of function mutant. The two B. rapa GI alleles each fully rescued the delayed flowering of Arabidopsis gi-201 but showed differential rescue of perturbations in red light inhibition of hypocotyl elongation and altered cold and salt tolerance. The B. rapa R500 GI allele, which failed to rescue the hypocotyl and abiotic stress phenotypes, disrupted circadian period determination in Arabidopsis. Analysis of chimeric B. rapa GI alleles identified the causal nucleotide polymorphism, which results in an amino acid substitution (S264A) between the two GI proteins. This polymorphism underlies variation in circadian period, cold and salt tolerance, and red light inhibition of hypocotyl elongation. Loss-of-function mutations of B. rapa GI confer delayed flowering, perturbed circadian rhythms in leaf movement, and increased freezing and increased salt tolerance, consistent with effects of similar mutations in Arabidopsis. Collectively, these data suggest that allelic variation of GI-and possibly of clock genes in general-offers an attractive target for molecular breeding for enhanced stress tolerance and potentially for improved crop yield.

  18. Longitudinal Spin Seebeck Effect in Bi-substituted Neodymium Iron Garnet on Gadolinium Gallium Garnet Substrate Prepared by MOD Method

    NASA Astrophysics Data System (ADS)

    Asada, H.; Kuwahara, A.; Sueyasu, K.; Ishibashi, T.; Liu, Q.; Lou, G.; Kishimoto, K.; Koyanagi, T.

    Bi-substituted Neodymium Iron Garnet (Nd3-xBixFe5O12, Bi:NIG) thin films with the Bi composition x=0-1.0 are prepared on both the (001) and (111) oriented gadolinium gallium garnet (GGG) substrates by a metal organic decomposition method. Crystalline qualities and magnetic properties of these films are examined by X-ray diffraction, atomic force microscopy and vibrating sample magnetometer. Longitudinal spin Seebeck effects (LSSEs) are investigated by means of the inverse spin Hall effect in a Pt film. The increase of LSSE voltage in Bi:NIG(x=0-1.0)/Pt bilayers on GGG(001) is observed with the increase of Bi composition. In the case of GGG(111), the LSSE voltage for Bi:NIG(x=1.0) is also larger than that for NIG.

  19. N9-substituted aromatic cytokinins with negligible side effects on root development are an emerging tool for in vitro culturing.

    PubMed

    Plíhal, Ondřej; Szüčová, Lucie; Galuszka, Petr

    2013-06-01

    Natural cytokinins as well as the majority of their synthetic derivatives show negative effects on root growth and development. Changes in morphology, primarily linked to the inhibition of the cell division in the meristematic zone, are manifested as thickening and shortening of the primary root and impaired lateral root branching. Rational design of cytokinin derivatives can partially overcome these drawbacks and reduce the negative effects. Using our database of cytokinin derivatives, we selected several aromatic cytokinin analogs with modifications at the N9 atom of the adenine moiety. We found that tetrahydropyranyl and tetrahydrofuranyl substitutions at the N9 atom led to enhanced acropetal transport of the modified cytokinin, and both derivatives also showed weak anticytokinin activity. Consequently, changes in the distribution of the active cytokinin pool together with gradual metabolic conversion of the modified cytokinin to its free form prevent root growth inhibition that limits cytokinin utilization in micropropagation techniques.

  20. Chemical Substitution and High Pressure Effects on Superconductors in the LnOBiS$_2$ (Ln = La-Nd) System

    SciTech Connect

    Fang, Yuankan; Wolowiec, Christian T.; Yazici, Duygu; Maple, M. Brian

    2015-12-14

    A large number of compounds which contain BiS$_2$ layers exhibit enhanced superconductivity upon electron doping. Much interest and research effort has been focused on BiS$_2$-based compounds which provide new opportunities for exploring the nature of superconductivity. Important to the study of BiS2-based superconductors is the relation between structure and superconductivity. By modifying either the superconducting BiS$_2$ layers or the blocking layers in these layered compounds, one can effectively tune the lattice parameters, local atomic environment, electronic structure, and other physical properties of these materials. In this article, we will review some of the recent progress on research of the effects of chemical substitution in BiS$_2$-based compounds, with special attention given to the compounds in the LnOBiSS$_2$ (Ln = La-Nd) system. Strategies which are reported to be essential in optimizing superconductivity of these materials will also be discussed.

  1. Effect of placebo substitution during long-term betamethasone valerate aerosol treatment in asthmatic children.

    PubMed Central

    Frears, J; Hodgson, S; Friedman, M

    1975-01-01

    Ten children with severe asthma, who had been well controlled on maintenance betamethasone valerate aerosol for an average of 11 months, were given placebo aerosols without their knowledge. The period of placebo substitution was campared with one 28-day period of betamethasone valerate therapy beforehand, and two 28-day periods afterwards. Symptoms were increased during the placebo period, and patients did not return to their previous well-controlled state until the second month after reinstitution of therapy. Changes in the means of twice-daily peak expiratory flow readings (PEFR) followed the same pattern as changes in symptoms. The exacerbation of asthma which occurred during placebo treatment was accompanied by a widening in the diurnal variation between morning and evening PEFR. In comparison with the previous period, morning PEFR fell by a greater amount than evening PEFR. Standardized running tests suggest an increase in exercise-induced bronchoconstriction and in the Exercise Lability Index when the child was receiving only placebo treatment as compared with betamethasone valerate treatment. The trial provided further evidence of the efficacy of betamethasone valerate aerosol in the prophylatic therapy of severe childhood asthma. As 2 of these children were able to discontinue long-term therapy it is unlikely that this drug causes dependency. PMID:1103750

  2. Studies on organic semiconductors. 15: Effects of the substituents on the photoconductivities of substituted anthracenes

    NASA Technical Reports Server (NTRS)

    Sugimoto, A.; Kato, S.; Inoue, H.; Imoto, E.

    1985-01-01

    The photocurrents of the substituted anthracenes, 1,5-diacetylanthracene (2), 1-acetylanthracene (3), 9-acetylanthracene (4), 1,5-dichloroanthracene (5), 1,5-diethylanthracene (6), 1,5-dimethoxyanthracene (7), 9-cyanoanthracene (8), and anthracene (1) were measured by using their surface type cells in nitrogen. The compounds of (1), (5), (6), (7), and (8) showed the photocurrent spectra which corresponded to the absorption spectra of their evaporated films. In the cases of (2) and (3), however, the anomalous photocurrent appeared in the threshold region of their absorption spectra. The appearance of the anomalous photocurrent was characteristic of anthracenes having the acetyl group at 1- and/or 5-position. The magnitude of the photocurrents of the 1,5-disubstituted anthracenes was similar to that of (1). The photocurrents of the monosubstituted anthracenes were smaller than that of (1). Among the monosubstituted anthracenes, the compound (4) showed no photocurrent under the same conditions. Contrary to the results obtained in the cases of phenazines, the photoconductivities of the anthracene derivatives became better in air.

  3. Phylogenetic relationship among horseshoe crab species: effect of substitution models on phylogenetic analyses.

    PubMed

    Xia, X

    2000-03-01

    The horseshoe crabs, known as living fossils, have maintained their morphology almost unchanged for the past 150 million years. The little morphological differentiation among horseshoe crab lineages has resulted in substantial controversy concerning the phylogenetic relationship among the extant species of horseshoe crabs, especially among the three species in the Indo-Pacific region. Previous studies suggest that the three species constitute a phylogenetically unresolvable trichotomy, the result of a cladogenetic process leading to the formation of all three Indo-Pacific species in a short geological time. Data from two mitochondrial genes (for 16S ribosomal rRNA and cytochrome oxidase subunit I) and one nuclear gene (for coagulogen) in the four species of horseshoe crabs and outgroup species were used in a phylogenetic analysis with various substitution models. All three genes yield the same tree topology, with Tachypleus-gigas and Carcinoscorpius-rotundicauda grouped together as a monophyletic taxon. This topology is significantly better than all the alternatives when evaluated with the RELL (resampling estimated log-likelihood) method.

  4. Effect of particle size on structural, magnetic and dielectric properties of manganese substituted nickel ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Kumar, E. Ranjith; Kamzin, Aleksandr S.; Prakash, T.

    2015-03-01

    Mn substituted NiFe2O4 ferrite nanoparticles (Mn-NiFe2O4) were synthesized by the auto-combustion method. Their actions were carried out at different fuel ratios (50%, 75% and 100%). The nanoparticles have been investigated by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. The average crystallite size of the synthesized and annealed samples was between 25 and 75 nm, which were found to be dependent on both fuel ratio and annealing temperatures. However, lattice parameters, interplanar spacing and grain size were controlled by varying the fuel ratio. Magnetic characterizations of the nanoparticles were carried out using a vibrating sample magnetometer at room temperature. The saturation magnetization was computed and found to lie between 6 emu/g and 57 emu/g depending on the particle size of the studied sample. The coercivity was found to exhibit non-monotonic behavior with the particle size. Such behavior can be accounted for by the combination between surface anisotropy and thermal energies. The value of dielectric constant and dielectric loss was found to exhibit almost linear dependence on the particle size.

  5. Aluminum substitution in quartz and its effect on dissolved H2O

    NASA Astrophysics Data System (ADS)

    Riggi, V. S.

    2014-12-01

    Trivalent aluminum is known to substitute for tetravalent silicon in quartz. However, this charge imbalance requires the presence of an additional +1 ion for charge compensation - a role that can be played by dissolved hydrogen species ("water") in the form of H+ bonded to oxygen. The correlation between the concentrations of aluminum and water in quartz was investigated experimentally and found to be significant. FTIR was used to measure water concentrations in thin (<1mm) doubly-polished samples of synthetic quartz grown over a range of pressures and temperatures. The quartz was grown from a mixture of amorphous silica powder, aluminum hydroxide powder, and distilled water. Two techniques were utilized to obtain accurate measurements representative of the sample. Depending on the size and visible geometry of the crystals, they were measured either with the c-axis parallel to the IR beam or in groups of ten at random orientations. Aluminum was determined via electron microprobe. The molar concentrations of Al and H were found to be positively correlated.

  6. Effect of Fe3+ substitution on structural, optical and magnetic properties of barium titanate ceramics

    NASA Astrophysics Data System (ADS)

    Dang, N. V.; Dung, N. T.; Phong, P. T.; Lee, In-Ja

    2015-01-01

    Multiferroic BaTi1-xFexO3 (0≤x≤0.12) materials were synthesized using the solid-state reaction method. The influence of Fe on the crystalline structure, the electronic structure, the optical properties and the magnetic property of BaTi1-xFexO3 samples were investigated. The obtained X-ray diffraction patterns, Raman and UV-vis spectra showed that the structure of the material sensitively depends on Fe dopant content, x, and transforms gradually from the tetragonal (P4mm) phase to the hexagonal (P63/mmc) one with increasing x. The photoluminescence emission of BaTi1-xFexO3 was attributed to structural disorder. All of the samples exhibit both ferroelectricity and ferromagnetism at room temperature. The relaxor like behavior was observed for all samples. The magnetization at a magnetic field of 1 T abnormally depends on x, increases up to 0.1 then decreases monotonously afterward. This anomaly in the magnetic behavior can be explained in terms of the changes in the oxidation state of ions such as the Fe3+-to-Fe4+ and/or Ti4+-to-Ti3+ change induced by oxygen vacancies. The substitution of Fe into Ti sites also causes the changes in the conductivity of the material and impurity (acceptor) levels in the band gap, which can be evident from the absorption spectra, and time-dependent leakage current measured at room temperature.

  7. Effect of Bromine Substitution on Human Dermal Absorption of Polybrominated Diphenyl Ethers.

    PubMed

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-09-15

    Human dermal absorption of eight mono- to deca-brominated diphenyl ethers (PBDEs) was investigated for the first time using EPISKIN human skin equivalent tissue. Using a standard in vitro protocol, EPISKIN tissues mounted in specially designed diffusion cells were exposed to the target PBDEs for 24 h. Estimated steady-state flux (Jss) and permeation coefficients (Papp) across the skin increased with decreasing bromine substitution from BDE-153 (Papp = 4.0 × 10(-4) cm/h) to BDE-1 (Papp = 1.1 × 10(-2) cm/h). This was accompanied by an increase in the time required to traverse the skin tissue into the receptor fluid (lag time) from 0.25 h for BDE-1 to 1.26 h for BDE-153. Papp values for the studied PBDEs were correlated significantly (P < 0.05) with physicochemical parameters like water solubility and log KOW. While less brominated congeners achieved faster dermal penetration, higher PBDEs displayed greater accumulation within the skin tissue. The PBDEs thus accumulated represent a contaminant depot from which they may be slowly released to the systemic circulation over a prolonged period. Maximal percutaneous penetration was observed for BDE-1 (∼ 30% of the applied 500 ng/cm(2) dose). Interestingly, BDE-183 and BDE-209 showed very low dermal absorption, exemplified by a failure to reach the steady state within the 24 h exposure period that was studied.

  8. Substitution effect on phenalenyl backbone in the rate of organozinc catalyzed ROP of cyclic esters.

    PubMed

    Sen, Tamal K; Mukherjee, Arup; Modak, Arghya; Mandal, Swadhin K; Koley, Debasis

    2013-02-07

    A series of zinc complexes (1-6) supported by substituted phenalenyl ligands was synthesized by reacting the phenalenyl ligands with diethyl zinc under ethane evolution. The solid state structures of these complexes (1-6) were determined by single crystal X-ray crystallography. Furthermore, the organozinc complexes (4-6) were tested for the polymerization of cyclic esters as efficient catalysts for the ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) in the presence of benzyl alcohol (BnOH) as initiator. Complex 4 exhibited remarkably higher rate of polymerization under identical reaction condition than complexes 5 and 6. The polymerization of ε-caprolactone produced polymer with narrow polydispersities (M(w)/M(n) = 1.06 to 1.22), while the polymerization of lactide monomers afforded polylactides with polydispersity values ranging from 1.08 to 1.8. The kinetic experiments unravelled a controlled polymerization. The controlled nature of polymerization was further utilized in the preparation of the block copolymer poly(CL)block-poly(rac-LA).

  9. Effect of Ho substitution on structure and magnetic properties of BiFeO{sub 3}

    SciTech Connect

    Suresh, Pittala; Srinath, S.; Babu, P. D.

    2014-05-07

    Structure and magnetic properties of trivalent Ho substituted BiFeO{sub 3} (Ho{sub x}Bi{sub 1−x}FeO{sub 3}) have been studied for the compositional range x = 0 to 0.2. The structure remains in rhombohedral R3c for x < 0.15, and further increase in x results a structural transition to orthorhombic Pnma. The decrease in Raman modes and the appearance of new mode at 475 cm{sup −1} confirms the structural changes. Ho doping at Bi site breaks the spin cycloid of BiFO{sub 3} and leads to the observation of ferromagnetic order at low temperatures. With increase in temperature, the M-H curves exhibit a pinching leading to double hysteresis loops. A minimum is observed in M-T curves for low fields at compensation temperature (Θ{sub C}) and H{sub C} attains a maximum close to Θ{sub C}. Variation of H{sub C} with temperature is discussed in terms of a model consisting of two sublattices. The improved magnetic properties achieved by Ho doping enhance the potential of BiFeO{sub 3} for multiferroic applications.

  10. Allele-Specific Reduction of the Mutant Huntingtin Allele Using Transcription Activator-Like Effectors in Human Huntington's Disease Fibroblasts.

    PubMed

    Fink, Kyle D; Deng, Peter; Gutierrez, Josh; Anderson, Joseph S; Torrest, Audrey; Komarla, Anvita; Kalomoiris, Stefanos; Cary, Whitney; Anderson, Johnathon D; Gruenloh, William; Duffy, Alexandra; Tempkin, Teresa; Annett, Geralyn; Wheelock, Vicki; Segal, David J; Nolta, Jan A

    2016-01-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an abnormal expansion of CAG repeats. Although pathogenesis has been attributed to this polyglutamine expansion, the underlying mechanisms through which the huntingtin protein functions have yet to be elucidated. It has been suggested that postnatal reduction of mutant huntingtin through protein interference or conditional gene knockout could prove to be an effective therapy for patients suffering from HD. For allele-specific targeting, transcription activator-like effectors (TALE) were designed to target single-nucleotide polymorphisms (SNP) in the mutant allele and packaged into a vector backbone containing KRAB to promote transcriptional repression of the disease-associated allele. Additional TALEs were packaged into a vector backbone containing heterodimeric FokI and were designed to be used as nucleases (TALEN) to cause a CAG-collapse in the mutant allele. Human HD fibroblasts were treated with each TALE-SNP or TALEN. Allele-expression was measured using a SNP-genotyping assay and mutant protein aggregation was quantified with Western blots for anti-ubiquitin. The TALE-SNP and TALEN significantly reduced mutant allele expression (p < 0.05) when compared to control transfections while not affecting expression of the nondisease allele. This study demonstrates the potential of allele-specific gene modification using TALE proteins, and provides a foundation for targeted treatment for individuals suffering from Huntington's or other genetically linked diseases.

  11. Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: ππ*-πσ* energy gap propensity and ortho-substitution effect.

    PubMed

    Pino, G A; Oldani, A N; Marceca, E; Fujii, M; Ishiuchi, S-I; Miyazaki, M; Broquier, M; Dedonder, C; Jouvet, C

    2010-09-28

    Lifetimes of the first electronic excited state (S(1)) of fluorine and methyl (o-, m-, and p-) substituted phenols and their complexes with one ammonia molecule have been measured for the 0(0) transition and for the intermolecular stretching σ(1) levels in complexes using picosecond pump-probe spectroscopy. Excitation energies to the S(1) (ππ*) and S(2) (πσ*) states are obtained by quantum chemical calculations at the MP2 and CC2 level using the aug-cc-pVDZ basis set for the ground-state and the S(1) optimized geometries. The observed lifetimes and the energy gaps between the ππ* and πσ* states show a good correlation, the lifetime being shorter for a smaller energy gap. This propensity suggests that the major dynamics in the excited state concerns an excited state hydrogen detachment or transfer (ESHD/T) promoted directly by a S(1)/S(2) conical intersection, rather than via internal conversion to the ground-state. A specific shortening of lifetime is found in the o-fluorophenol-ammonia complex and explained in terms of the vibronic coupling between the ππ* and πσ* states occurring through the out-of-plane distortion of the C-F bond.

  12. The effect of substitution of Mn by Fe and Cr on the martensitic transition in the Ni50Mn34In16 alloy.

    PubMed

    Sharma, V K; Chattopadhyay, M K; Nath, S K; Sokhey, K J S; Kumar, R; Tiwari, P; Roy, S B

    2010-12-08

    The potential shape memory alloy Ni(50)Mn(34)In(16) is studied with partial substitution of Mn with Fe and Cr to investigate the effect of such substitution on the martensitic transition in the Ni-Mn-In alloy system. The results of ac susceptibility, magnetization and electrical resistivity measurements show that while the substitution with Cr increases the martensitic transition temperature, the substitution with Fe decreases it. Possible reasons for this shift in martensitic transition are discussed. Evidence of kinetic arrest of the austenite to martensite phase transition in the Fe substituted alloys is also presented. Unlike the kinetic arrest of the austenite to martensite phase transition in the parent Ni(50)Mn(34)In(16) alloy which takes place in the presence of high external magnetic field, the kinetic arrest of the austenite to martensite phase transition in the Fe doped alloy occurs even in zero magnetic field. The Cr substituted alloys, on the other hand, show no signature of kinetic arrest of this phase transition.

  13. Analysis of a Larger SNP Dataset from the HapMap Project Confirmed That the Modern Human A Allele of the ABO Blood Group Genes Is a Descendant of a Recombinant between B and O Alleles.

    PubMed

    Itou, Masaya; Sato, Mitsuharu; Kitano, Takashi

    2013-01-01

    The human ABO blood group gene consists of three main alleles (A, B, and O) that encode a glycosyltransferase. The A and B alleles differ by two critical amino acids in exon 7, and the major O allele has a single nucleotide deletion (Δ261) in exon 6. Previous evolutionary studies have revealed that the A allele is the most ancient, B allele diverged from the A allele with two critical amino acid substitutions in exon 7, and the major O allele diverged from the A allele with Δ261 in exon 6. However, a recent phylogenetic network analysis study showed that the A allele of humans emerged through a recombination between the B and O alleles. In the previous study, a restricted dataset from only two populations was used. In this study, therefore, we used a large single nucleotide polymorphism (SNP) dataset from the HapMap Project. The results indicated that the A101-A201-O09 haplogroup was a recombinant lineage between the B and O haplotypes, containing the intact exon 6 from the B allele and the two critical A type sites in exon 7 from the major O allele. Its recombination point was assumed to be located just behind Δ261 in exon 6.

  14. Effect of substitution of low linolenic acid soybean oil for hydrogenated soybean oil on fatty acid intake.

    PubMed

    DiRienzo, Maureen A; Astwood, James D; Petersen, Barbara J; Smith, Kim M

    2006-02-01

    Low linolenic acid soybean oil (LLSO) has been developed as a substitute for hydrogenated soybean oil to reduce intake of trans FA while improving stability and functionality in processed foods. We assessed the dietary impact of substitution of LLSO for hydrogenated soybean oil (HSBO) used in several food categories. All substitutions were done using an assumption of 100% market penetration. The impact of this substitution on the intake of five FA and trans FA was assessed. Substitution of LLSO for current versions of HSBO resulted in a 45% decrease in intake of trans FA. Impacts on other FA intakes were within the realm of typical dietary intakes. No decrease in intake of alpha-linolenic acid was associated with the use of LLSO in place of HSBO because LLSO substitutes for HSBO that are already low in alpha-linolenic acid.

  15. Identification and DNA sequence analysis of 15 new {alpha}{sub 1}-antitrypsin variants, including two PI*QO alleles and one deficient PI*M allele

    SciTech Connect

    Faber, J.P.; Kirchgesser, M.; Schwaab, R.; Bidlingmaier, F.; Poller, W.; Weidinger, S.; Olek, K. |

    1994-12-01

    The authors have investigated the molecular basis of 15 new {alpha}{sub 1}-antitrypsin ({alpha}1AT) variants. Phenotyping by isoelectric focusing (IEF) was used as a screening method to detect {alpha}1AT variants at the protein level. Genotyping was then performed by sequence analysis of all coding exons, exon-intron junctions, and the hepatocyte-specific promotor region including exon Ic. Three of these rare variants are alleles of clinical relevance, associated with undetectable or very low serum levels of {alpha}1AT: the PI*Q0saarbruecken allele generated by a 1-bp C-nucleotide insertion within a stretch of seven cytosines spanning residues 360-362, resulting in a 3{prime} frameshift and the acquisition of a stop codon at residue 376; a point mutation in the PI*Q0lisbon allele, resulting in a single amino acid substitution Thr{sup 68}(ACC){yields}Ile(ATC); and an in-frame trinucleotide deletion {Delta}Phe{sup 51} (TTC) in the highly deficient PI*Mpalermo allele. The remaining 12 alleles are associated with normal {alpha}1AT serum levels and are characterized by point mutations causing single amino acid substitutions in all but one case. This exception is a silent mutation, which does not affect the amino acid sequence. The limitation of IEF compared with DNA sequence analysis, for identification of new variants, their generation by mutagenesis, and the clinical relevance of the three deficiency alleles are discussed.

  16. Frequency of FCGR3B Alleles in Thai Blood Donors

    PubMed Central

    Kaset, Chollanot; Leetrakool, Nipapan; Intharanut, Kamphon

    2013-01-01

    Background Human neutrophil antigens (HNAs) are involved in autoimmune and alloimmune neutropenia and transfusion-related acute lung injury. The HNA-1 system is important in immunogenetics, and allele frequencies have been described in different populations. This study investigated the frequency of FCGR3B alleles encoding HNA-1a, HNA-1b, and HNA-1c among Thai blood donors and compared these frequencies with those previously reported for other populations. Methods Eight hundred DNA samples obtained from unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok, and the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, were included. Samples were simultaneously typed for each FCGR3B allele using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. Results The frequencies of FCGR3B*1, FCGR3B*2, and FCGR3B*3 alleles in central Thai blood donors were 0.548, 0.452, and 0.004, respectively; only FCGR3B*1 and FCGR3B*2 alleles were found in northern Thai blood donors (0.68 and 0.32, respectively). Compared with other Asian populations, central Thais had higher frequencies of the FCGR3B*2 allele (P<0.001), while the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in northern Thais were similar to those previously reported in Taiwanese and Japanese populations. In contrast, the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in the northern Thai population were statistically different from those observed in central Thai, Korean, German, and Turkish populations. Conclusions FCGR3B allele frequencies were significantly different between central and northern Thai blood donors. Our in-house PCR-SSP method is a simple, cost-effective, and convenient method for FCGR3B allele detection. PMID:24205492

  17. Microsatellite null alleles and estimation of population differentiation.

    PubMed

    Chapuis, Marie-Pierre; Estoup, Arnaud

    2007-03-01

    Microsatellite null alleles are commonly encountered in population genetics studies, yet little is known about their impact on the estimation of population differentiation. Computer simulations based on the coalescent were used to investigate the evolutionary dynamics of null alleles, their impact on F(ST) and genetic distances, and the efficiency of estimators of null allele frequency. Further, we explored how the existing method for correcting genotype data for null alleles performed in estimating F(ST) and genetic distances, and we compared this method with a new method proposed here (for F(ST) only). Null alleles were likely to be encountered in populations with a large effective size, with an unusually high mutation rate in the flanking regions, and that have diverged from the population from which the cloned allele state was drawn and the primers designed. When populations were significantly differentiated, F(ST) and genetic distances were overestimated in the presence of null alleles. Frequency of null alleles was estimated precisely with the algorithm presented in Dempster et al. (1977). The conventional method for correcting genotype data for null alleles did not provide an accurate estimate of F(ST) and genetic distances. However, the use of the genetic distance of Cavalli-Sforza and Edwards (1967) corrected by the conventional method gave better estimates than those obtained without correction. F(ST) estimation from corrected genotype frequencies performed well when restricted to visible allele sizes. Both the proposed method and the traditional correction method have been implemented in a program that is available free of charge at http://www.montpellier.inra.fr/URLB/. We used 2 published microsatellite data sets based on original and redesigned pairs of primers to empirically confirm our simulation results.

  18. 30 CFR 243.12 - May I substitute a demonstration of financial solvency for a bond posted before the effective...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT SUSPENSIONS PENDING APPEAL AND BONDING-MINERALS REVENUE MANAGEMENT General Provisions § 243.12 May I substitute...

  19. Effects of Bi-Pb substitution in (Bi,Pb)2223 thin films fabricated by sputtering method

    NASA Astrophysics Data System (ADS)

    Mori, Zon; Koba, Shinichiro

    2016-12-01

    Superconducting Bi2-nPbnSr2Ca2Cu3Ox (2223) thin films were deposited by using a multi-target sputtering system. A multi-target system enables the fabrication of thin films with varying compositions. First, we tried to obtain 2223 single-phase films by using the as-grown method. However, it is difficult to remove the influence deficiency of Bi atoms at high temperatures, so only thin films with mixed crystals of Bi2Sr2Ca1Cu2Ox (2212) and 2223 were obtained. We next conducted post-annealing to improve the crystallinity of the thin films and studied the effects of substitution of Bi with Pb. As a result, single-phase 2223 thin films with a critical temperature of 108 K were obtained by optimizing the annealing conditions and the thin film composition.

  20. Porous calcium polyphosphate bone substitutes: additive manufacturing versus conventional gravity sinter processing-effect on structure and mechanical properties.

    PubMed

    Hu, Youxin; Shanjani, Yaser; Toyserkani, Ehsan; Grynpas, Marc; Wang, Rizhi; Pilliar, Robert

    2014-02-01

    Porous calcium polyphosphate (CPP) structures proposed as bone-substitute implants and made by sintering CPP powders to form bending test samples of approximately 35 vol % porosity were machined from preformed blocks made either by additive manufacturing (AM) or conventional gravity sintering (CS) methods and the structure and mechanical characteristics of samples so made were compared. AM-made samples displayed higher bending strengths (≈1.2-1.4 times greater than CS-made samples), whereas elastic constant (i.e., effective elastic modulus of the porous structures) that is determined by material elastic modulus and structural geometry of the samples was ≈1.9-2.3 times greater for AM-made samples. X-ray diffraction analysis showed that samples made by either method displayed the same crystal structure forming β-CPP after sinter annealing. The material elastic modulus, E, determined using nanoindentation tests also showed the same value for both sample types (i.e., E ≈ 64 GPa). Examination of the porous structures indicated that significantly larger sinter necks resulted in the AM-made samples which presumably resulted in the higher mechanical properties. The development of mechanical properties was attributed to the different sinter anneal procedures required to make 35 vol % porous samples by the two methods. A primary objective of the present study, in addition to reporting on bending strength and sample stiffness (elastic constant) characteristics, was to determine why the two processes resulted in the observed mechanical property differences for samples of equivalent volume percentage of porosity. An understanding of the fundamental reason(s) for the observed effect is considered important for developing improved processes for preparation of porous CPP implants as bone substitutes for use in high load-bearing skeletal sites.

  1. Effects of sodium chloride salting and substitution with potassium chloride on whey expulsion of Cheddar cheese.

    PubMed

    Lu, Y; McMahon, D J

    2015-01-01

    A challenge in manufacturing reduced-sodium cheese is that whey expulsion after salting decreases when less salt is applied. Our objectives were (1) to determine whether changing the salting method would increase whey syneresis when making a lower sodium cheese and (2) to better understand factors contributing to salt-induced curd syneresis. Unsalted milled Cheddar curds were salted using different salting intervals (5 or 10 min), different salting levels (20, 25, or 30g/kg), different numbers of applications when using only 20g/kg salt (1, 2, or 3 applications), and salting with the equivalent of 30g/kg NaCl using a 2:1 molar ratio of NaCl and KCl. Whey from these curds was collected every 5 or 10 min until 30 or 40 min after the start of salting, and curds were subsequently pressed for 3h. Additional trials were conducted in which salted milled Cheddar cheese curd was immersed at 22°C for 6h in various solutions to determine how milled curd pieces respond to different levels of salt and Ca. The use of 10-min intervals delayed whey syneresis without influencing total whey expulsion or cheese composition after pressing. Lowering the salt level reduced whey expulsion, resulting in cheeses with higher moisture and slightly lower pH. Adding salt faster did not increase whey expulsion in reduced-salt cheese. Partial substitution with KCl restored the extent of whey expulsion. When salted milled curd was immersed in a 30g/L salt solution, there was a net influx of salt solution into the curd and curd weight increased. When curd was immersed in 60g/L salt solution, a contraction of curd occurred. Curd shrinkage was more pronounced as the salt solution concentration was increased to 90 and 120g/L. Increasing the Ca concentration in test solutions (such that both serum and total Ca in the curd increased) also promoted curd contraction, resulting in lower curd moisture and pH and less weight gain by the curd. The proportion of Ca in the curd that was bound to the para

  2. FEEDING THE MUMMICHOG (FUNDULUS HERTERCLITUS), A DIET SPIKED WITH NON-ORTHO AND MONO-ORTHO SUBSTITUTED POLYCHLORINATED BIPHENYLS:ACCUMULATION AND EFFECTS

    EPA Science Inventory

    A laboratory model was developed to predict exposure effects in the field. Accumulation of non-ortho- and mono-ortho-substituted PCBs in liver tissue and their effects on mummichogs (Fundulus heteroclitus) were investigated. An artificial diet spiked with a mixture of eight PCB c...

  3. Assignment of SNP allelic configuration in polyploids using competitive allele-specific PCR: application to citrus triploid progeny

    PubMed Central

    Cuenca, José; Aleza, Pablo; Navarro, Luis; Ollitrault, Patrick

    2013-01-01

    Background Polyploidy is a major component of eukaryote evolution. Estimation of allele copy numbers for molecular markers has long been considered a challenge for polyploid species, while this process is essential for most genetic research. With the increasing availability and whole-genome coverage of single nucleotide polymorphism (SNP) markers, it is essential to implement a versatile SNP genotyping method to assign allelic configuration efficiently in polyploids. Scope This work evaluates the usefulness of the KASPar method, based on competitive allele-specific PCR, for the assignment of SNP allelic configuration. Citrus was chosen as a model because of its economic importance, the ongoing worldwide polyploidy manipulation projects for cultivar and rootstock breeding, and the increasing availability of SNP markers. Conclusions Fifteen SNP markers were successfully designed that produced clear allele signals that were in agreement with previous genotyping results at the diploid level. The analysis of DNA mixes between two haploid lines (Clementine and pummelo) at 13 different ratios revealed a very high correlation (average = 0·9796; s.d. = 0·0094) between the allele ratio and two parameters [θ angle = tan−1 (y/x) and y′ = y/(x + y)] derived from the two normalized allele signals (x and y) provided by KASPar. Separated cluster analysis and analysis of variance (ANOVA) from mixed DNA simulating triploid and tetraploid hybrids provided 99·71 % correct allelic configuration. Moreover, triploid populations arising from 2n gametes and interploid crosses were easily genotyped and provided useful genetic information. This work demonstrates that the KASPar SNP genotyping technique is an efficient way to assign heterozygous allelic configurations within polyploid populations. This method is accurate, simple and cost-effective. Moreover, it may be useful for quantitative studies, such as relative allele-specific expression analysis and bulk segregant analysis

  4. Effects of isomorphous substitution of a coordination polymer on the properties and its application in electrochemical sensing

    SciTech Connect

    Zhou, Bo; Liang, Li-Mei; Yao, Jie

    2014-07-01

    This work concerns the isomorphous substitution of coordination polymers (CPs) and its effect on the optical and electrochemical properties. The application of CPs in electrochemical sensing was studied as well. Isomorphous coordination polymers, [Co{sub x}Zn{sub 1−x}tyr]{sub n} (tyr=L-tyrosine), where x (0–1) was controlled by the Co/Zn ratios of raw materials, were successfully synthesized via a hydrothermal method, as proved by XRD and EDS results. Their UV–vis DRS and fluorescence spectra change gradually along with the composition. Cyclic voltammograms of modified electrodes, [Co{sub x}Zn{sub 1−x}tyr]{sub n}/GCE, show that as more and more Zn replaced Co, the current signal decreases greatly and the potential shifts negatively. Much attention was paid to [Cotyr]{sub n} due to its highest sensitivity. Refreshable modified carbon paste electrode, [Cotyr]{sub n}-CPE, was used to determine nitrite, and showed pretty good performance as evidenced by chronoamperometry. The response was made very fast within mere 5 s. The linear detection range was from 5.00×10{sup −5} to 3.45×10{sup −3} M, with sensitivity of 263.4 mA mol{sup −1} L cm{sup −2}. The detection limit was found to be 2.00×10{sup −5} M. The sensor also showed good antiinterference and reproducibility. - Graphical abstract: Evolution of the optical and electrochemical properties of isomorphic coordination polymers [Co{sub x}Zn{sub 1−x}tyr]{sub n} along with the changing of x was studied. The CP also showed perfect performance in the electrochemical determination of nitrite. - Highlights: • Isomorphous substitution of coordination polymers (CPs). • Substitution-caused evolution of optical and electrochemical properties of CPs. • Application of CPs in electrochemical sensing, an incipient area. • Perfect performance of CPs in electrochemical determination of nitrite.

  5. Simple, heart-smart substitutions

    MedlinePlus

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart smart substitutions; Wellness - heart smart substitutions

  6. Quantifying RNA allelic ratios by microfluidic multiplex PCR and sequencing.

    PubMed

    Zhang, Rui; Li, Xin; Ramaswami, Gokul; Smith, Kevin S; Turecki, Gustavo; Montgomery, Stephen B; Li, Jin Billy

    2014-01-01

    We developed a targeted RNA sequencing method that couples microfluidics-based multiplex PCR and deep sequencing (mmPCR-seq) to uniformly and simultaneously amplify up to 960 loci in 48 samples independently of their gene expression levels and to accurately and cost-effectively measure allelic ratios even for low-quantity or low-quality RNA samples. We applied mmPCR-seq to RNA editing and allele-specific expression studies. mmPCR-seq complements RNA-seq for studying allelic variations in the transcriptome.

  7. Sandia octahedral molecular sieves (SOMS): structural and property effects of charge-balancing the M(IV)-substituted (M = Ti, Zr) Niobate framework.

    PubMed

    Nyman, May; Tripathi, Akhilesh; Parise, John B; Maxwell, Robert S; Nenoff, Tina M

    2002-02-27

    Sandia octahedral molecular sieves (SOMS) is an isostructural, variable composition class of ion exchangers with the general formula Na(2)Nb(2-x)M(IV)(x)O (6-x)(OH)(x).H(2)O (M(IV) = Ti, Zr; x = 0.04-0.40) where up to 20% of the framework Nb(V) can be substituted with Ti(IV) or Zr(IV). This class of molecular sieves is easily converted to perovskite through low-temperature heat treatment (500-600 degrees C). This report provides a detailed account of how the charge imbalance of this Nb(V)-M(IV) substitution is compensated. X-ray powder diffraction with Rietveld refinement, infrared spectroscopy, thermogravimetric analysis, (23)Na MAS NMR, and (1)H MAS NMR were used to determine how the framework anionic charge is cation-balanced over a range of framework compositions. All spectroscopic evidence indicated a proton addition for each M(IV) substitution. Evidences for variable proton content included (1) increasing OH observed by (1)H MAS NMR with increasing M(IV) substitution, (2) increased infrared band broadening indicating increased H-bonding with increasing M(IV) substitution, (3) increased TGA weight loss (due to increased OH content) with increasing M(IV) substitution, (4) no variance in population on the sodium sites (indicated by Rietveld refinement) with variable composition, and (5) no change in the (23)Na MAS NMR spectra with variable composition. Also observed by infrared spectroscopy and (23)Na MAS NMR was increased disorder on the Nb(V)/M(IV) framework sites with increasing M(IV) substitution, evidenced by broadening of these spectral features. These spectroscopic studies, along with ion exchange experiments, also revealed the effect of the Nb(V)/M(IV) framework substitution on materials properties. Namely, the temperature of conversion to NaNb(1-x)M(IV)(x)O(3) (M = Ti, Zr) perovskite increased with increasing Ti in the framework and decreased with increasing Zr in the framework. This suggested that Ti stabilizes the SOMS framework and Zr destabilizes

  8. Construction of high efficiency non-doped deep blue emitters based on phenanthroimidazole: remarkable substitution effects on the excited state properties and device performance.

    PubMed

    Wang, Zhiming; Feng, Ying; Zhang, Shitong; Gao, Yu; Gao, Zhao; Chen, Yanming; Zhang, Xiaojuan; Lu, Ping; Yang, Bing; Chen, Ping; Ma, Yuguang; Liu, Shiyong

    2014-10-14

    Aryl-substituted phenanthroimidazoles (APIs) are beneficial due to their facile synthesis, thermal properties, high quantum yields, and exciton efficiencies obtained by a reverse intersystem crossing (RISC) process. However, it is puzzling how to combine high quantum yields, exciton utilizing ratios and color purity with stable blue-emitting compounds via coupling. Here, BPPI and N-BPPI are utilized as model compounds for understanding C2- and N1-substitution effects via constructing dimers in each coupling position. By integrating the information obtained from DFT calculations, photophysical analysis, and OLED performance, valuable guidance was obtained. C2-substituted groups typically offer a large orbital overlap between the LE states with large oscillator strengths, and play an important role in the maximum peak area and quantum yields. N1-substituted groups contribute to enhanced orbital coupling and cause excitons to transform freely between different excited states. Unexpected results from the decreased barriers of the N1-coupled system included the loss of PL efficiency and increased emission spectral width, which are important for efficiency and color purity of deep blue emitters. The substitution effects are consistent with most reported results. Therefore, this work may be useful for the generation of non-doped deep blue electroluminescent API-based materials.

  9. Effect of Mg substitution on crystal structure and hydrogenation of Ce2Ni7-type Pr2Ni7

    NASA Astrophysics Data System (ADS)

    Iwase, Kenji; Mori, Kazuhiro; Terashita, Naoyoshi; Tashiro, Suguru; Suzuki, Tetsuya

    2017-03-01

    The effect of Pr being substituted by Mg in Pr2Ni7 with a Ce2Ni7-type structure was investigated by X-ray diffraction (XRD) and pressure-composition (P-C) isotherm measurements. The maximum hydrogen capacity of Pr2Ni7 reached 1.24 H/M in the first absorption process. However, 0.61 H/M hydrogen remained in the sample after the first desorption and the reversible hydrogen capacity decreased to 0.63 H/M. Severe peak broadening was observed in the XRD profile of Pr2Ni7H5.4 after the first P-C isotherm cycle. The metal sublattice of Pr2Ni7H5.4 is deformed and changes from the Ce2Ni7-type structure to a lower symmetry during hydrogenation, with no detection of an amorphous phase. Pr1.5Mg0.5Ni7 consists of two phases: 80% Gd2Co7-type and 20% PuNi3-type phases. Mg substitution leads to the relative stability of the Gd2Co7-type and PuNi3-type structures. The Gd2Co7-type and PuNi3-type structures are retained after the P-C isotherm. The reversible hydrogen capacity reached 1.05 H/M. The structural change during the hydrogen absorption-desorption cycle and the hydrogenation characteristics are changed by Mg atoms replacing Pr in the MgZn2-type cell.

  10. 50 MeV, Li3+ - ion irradiation effect on magnetic ordering of Y3+ - substituted yttrium iron garnet

    NASA Astrophysics Data System (ADS)

    Sharma, P. U.; Zankat, K. B.; Dolia, S. N.; Modi, K. B.

    2016-05-01

    This communication presents the effect of non-magnetic Y3+ ions substitution for magnetic Fe3+ ions and 50 MeV, Li3+ ion irradiation (fluence: 5 × 1013 ions/cm2) on magnetic ordering and Neel temperature of Y3+xFe5-xO12 (x = 0.0, 0.2, 0.4 and 0.6) garnet system, studied by means of X-ray powder diffractometry and thermal variation of low field (0.5 Oe) ac susceptibility measurements. The un-irradiated compositions exhibit normal ferrimagnetic behavior with decrease in transition temperature (TN) on increasing Y3+-concentration (x). The irradiated counterparts are characterized by tailing effect indicative of non-uniform effect of irradiation and lower value of TN. The results have been discussed based on the weakening of magnetic exchange interactions and cumulative effect of redistribution of cations and fractional creation of localized paramagnetic centers resulting from swift heavy ion irradiation. The Neel temperatures and exchange integrals have been calculated theoretically.

  11. Allele Frequencies at Microsatellite Loci: The Stepwise Mutation Model Revisited

    PubMed Central

    Valdes, A. M.; Slatkin, M.; Freimer, N. B.

    1993-01-01

    We summarize available data on the frequencies of alleles at microsatellite loci in human populations and compare observed distributions of allele frequencies to those generated by a simulation of the stepwise mutation model. We show that observed frequency distributions at 108 loci are consistent with the results of the model under the assumption that mutations cause an increase or decrease in repeat number by one and under the condition that the product Nu, where N is the effective population size and u is the mutation rate, is larger than one. We show that the variance of the distribution of allele sizes is a useful estimator of Nu and performs much better than previously suggested estimators for the stepwise mutation model. In the data, there is no correlation between the mean and variance in allele size at a locus or between the number of alleles and mean allele size, which suggests that the mutation rate at these loci is independent of allele size. PMID:8454213

  12. DESIGNING ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES

    EPA Science Inventory

    Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally imminent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of...

  13. The Effects of University-Industry Relationships and Academic Research on Scientific Performance: Synergy or Substitution?

    ERIC Educational Resources Information Center

    Manjarres-Henriquez, Liney; Gutierrez-Gracia, Antonio; Carrion-Garcia, Andres; Vega-Jurado, Jaider

    2009-01-01

    This paper evaluates whether university-industry relationships (UIR) and academic research activities have complementary effects on the scientific production of university lecturers. The analysis is based on a case study of two Spanish universities. We find that the effects of R&D contracts with industry, and academic research activity on…

  14. Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans

    PubMed Central

    Pritchard, Jonathan K.

    2016-01-01

    The site frequency spectrum (SFS) has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the “phylogenetically-conditioned SFS” or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC), combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans. PMID:27977673

  15. Characterization of Mhc-DRB allelic diversity in white-tailed deer (Odocoileus virginianus) provides insight into Mhc-DRB allelic evolution within Cervidae.

    PubMed

    Van Den Bussche, R A; Hoofer, S R; Lochmiller, R L

    1999-05-01

    Although white-tailed deer (Odocoileus virginianus) are one of North America's best studied mammals, no information is available concerning allelic diversity at any locus of the major histocompatibility complex in this taxon. Using the polymerase chain reaction, single-stranded conformation polymorphism analysis, and DNA sequencing techniques, 15 DRB exon 2 alleles were identified among 150 white-tailed deer from a single population in southeastern Oklahoma. These alleles represent a single locus and exhibit a high degree of nucleotide and amino acid polymorphism, with most amino acid variation occurring at positions forming the peptide binding sites. Furthermore, twenty-seven amino acid residues unique to white-tailed deer DRB alleles were detected, with 19 of these occurring at residues forming contact points of the peptide binding region. Significantly higher rates of nonsynonymous than synonymous substitutions were detected among these DRB alleles. In contrast to other studies of Artiodactyla DRB sequences, interallelic recombination does not appear to be playing a significant role in the generation of allelic diversity at this locus in white-tailed deer. To examine evolution of white-tailed deer (Odvi-DRB) alleles within Cervidae, we performed a phylogenetic analysis of all published red deer (Ceel-DRB), roe deer (Caca-DRB), and moose (Alal-DRB) DRB alleles. The phylogenetic tree clearly shows a trans-species persistence of DRB lineages among these taxa. Moreover, this phylogenetic tree provides insight into evolution of DRB allelic lineages within Cervidae and may aid in assignment of red deer DRB alleles to specific loci.

  16. Haplotype and AGG interspersion analysis of FMR1 alleles in a Croatian population: no founder effect detected in patients with fragile X syndrome.

    PubMed

    Dokić, H; Barisić, I; Culić, V; Lozić, B; Hećimović, S

    2008-10-01

    Several studies have suggested that fragile X syndrome (FRAXA), the most common inherited form of mental retardation, originated from a limited number of founder chromosomes. The aim of this study is to assess the genetic origin of fragile X syndrome in a Croatian population. We performed a haplotype analysis of the polymorphic loci DXS548 and FRAXAC1 in 18 unrelated fragile X and 56 control chromosomes. The AGG interspersion pattern of the FMR1 CGG repeat region was analyzed by sequencing. This is the first report on haplotype and AGG interspersion analysis of the fragile X syndrome gene in a Croatian population-the only eastern European population of Slavic origin analyzed so far. Our findings are intriguing, because they show a distinct distribution of the DXS548 and FRAXAC1 alleles in our fragile X population compared to other European fragile X populations. The DXS548/FRAXAC1 haplotype 194/154 (7-3), which is common among normal populations, was found to be the most frequent haplotype in our fragile X population as well. The AGG interspersion analysis indicated that AGG loss rather than haplotype may determine FMR1 allele instability. Our results suggest that no common ancestral X chromosome is associated with fragile X syndrome in the Croatian population studied. Further analysis of the origin of fragile X syndrome among other Slavic populations will be necessary to better define its eastern European distribution.

  17. Somatic homologous recombination in planta: the recombination frequency is dependent on the allelic state of recombining sequences and may be influenced by genomic position effects.

    PubMed

    Swoboda, P; Hohn, B; Gal, S

    1993-02-01

    We have previously described a non-selective method for scoring somatic recombination in the genome of whole plants. The recombination substrate consists of a defective partial dimer of Cauliflower Mosaic Virus (CaMV) sequences, which can code for production of viable virus only upon homologous recombination; this leads to disease symptoms on leaves. Brassica napus plants (rapeseed) harbouring the recombination substrate as a transgene were used to examine the time in plant development at which recombination takes place. The analysis of three transgene loci revealed recombination frequencies specific for each locus. Recombination frequencies were increased if more than one transgene locus was present per genome, either in allelic (homozygosity of the transgene locus) or in non-allelic positions. In both cases, the overall recombination frequency was found to be elevated to approximately the sum of the frequencies for the individual transgene loci or slightly higher, suggesting that the respective transgene loci behave largely independently of each other. For all plants tested (single locus, two or multiple loci) maximal recombination frequencies were of the order of 10(-6) events per cell division.

  18. An end to crossover designs for studies on the effect of sugar substitutes on caries?

    PubMed

    Mäkinen, K K

    2009-01-01

    Clinical trials and laboratory studies involving the administration of oral health treatments and foods have benefited from the observance of the so-called crossover study design. Field experience and a growing number of laboratory experiments have shown, however, that 'blind' reliance on crossover designs may in some instances lead to unexpected results and erroneous conclusions. Some dietary substances, antibiotic agents, and even fluoride applications may have long-term effects that call into question the appropriateness of the washout periods between treatments. Studies have also been conducted on compounds that have turned out to display synergistic effects. When long-term and synergistic effects are simultaneously present in trials involving a crossover design, difficulties may arise in the interpretation of results. This communication uses as an example the long-term clinical and microbiological effects of xylitol and suggests that inclusion of the crossover practice in clinical trials should be separately and carefully contemplated in each instance.

  19. μ-Calpain, calpastatin, and growth hormone receptor genetic effects on preweaning performance, carcass quality traits, and residual variance of tenderness in Angus cattle selected to increase minor haplotype and allele frequencies.

    PubMed

    Tait, R G; Shackelford, S D; Wheeler, T L; King, D A; Casas, E; Thallman, R M; Smith, T P L; Bennett, G L

    2014-02-01

    Genetic marker effects and interactions are estimated with poor precision when minor marker allele frequencies are low. An Angus population was subjected to marker assisted selection for multiple years to increase divergent haplotype and minor marker allele frequencies to 1) estimate effect size and mode of inheritance for previously reported SNP on targeted beef carcass quality traits; 2) estimate effects of previously reported SNP on nontarget performance traits; and 3) evaluate tenderness SNP specific residual variance models compared to a single residual variance model for tenderness. Divergent haplotypes within µ-calpain (CAPN1), and SNP within calpastatin (CAST) and growth hormone receptor (GHR) were successfully selected to increase their frequencies. Traits evaluated were birth BW, weaning BW, final BW, fat thickness, LM area, USDA marbling score, yield grade, slice shear force (SSF), and visible and near infrared predicted slice shear force. Both CAPN1 and CAST exhibited additive (P < 0.001) modes of inheritance for SSF and neither exhibited dominance (P ≥ 0.19). Furthermore, the interaction between CAPN1 and CAST for SSF was not significant (P = 0.55). Estimated additive effects of CAPN1 (1.049 kg) and CAST (1.257 kg) on SSF were large in this study. Animals homozygous for tender alleles at both CAPN1 and CAST would have 4.61 kg lower SSF (38.6% of the mean) than animals homozygous tough for both markers. There was also an effect of CAST on yield grade (P < 0.02). The tender CAST allele was associated with more red meat yield and less trimmable fat. There were no significant effects (P ≥ 0.23) for GHR on any of the traits evaluated in this study. Furthermore, CAST specific residual variance models were found to fit significantly better (P < 0.001) than single residual variance models for SSF, with the tougher genotypes having larger residual variance. Thus, the risk of a tough steak from the undesired CAST genotype is increased through both an

  20. Effect of the Ni site substitution on superconducting properties of YNi 2B 2C

    NASA Astrophysics Data System (ADS)

    Bud'ko, S. L.; Elmassalami, M.; Fontes, M. B.; Mondragon, J.; Vanoni, W.; Giordanengo, B.; Baggio-Saitovitch, E. M.

    1995-02-01

    Structural and superconducting properties of Y(Ni 1- xM x) 2B 2C compounds with MCo, Fe and Ru have been studied. A fast decrease of Tc with the concentration of the dopants was found. This effect can be attributed to the shift of the Fermi level induced by the dopant concentration with the additional contributions from the chemical-pressure effects and from the decrease of the electronic mean free path.

  1. Effects of substitution of different levels of steam-flaked corn for finely ground corn on lactation and digestion in early lactation dairy cows.

    PubMed

    Zhong, R Z; Li, J G; Gao, Y X; Tan, Z L; Ren, G P

    2008-10-01

    Eight multiparous Holstein cows, 4 of them fitted with rumen cannulas, were used to test the effects of substitution of steam-flaked corn (SFC) for equal amounts of finely ground corn (FGC) in diets on feed intake and digestion, blood metabolites, and lactation performance in early lactation dairy cows. Cows were fed 4 diets in a replicated 4 x 4 Latin square design. The fistulated cows formed 1 replicate. Each experimental period lasted for 3 wk. The 4 diets contained 0, 10, 20, or 40% SFC and 40, 30, 20, or 0% FGC (dry matter basis), respectively. The milk protein content and yield, milk solid nonfat content and yield, plasma glucose concentration, and dry matter intake increased as the proportion of SFC increased in diets. Apparent total tract digestibilities of dry matter, organic matter, neutral detergent fiber, acid detergent fiber, and average ruminal fluid NH(3)-N concentration decreased with increasing levels of SFC. The ruminal fluid pH was not affected by the substitution of SFC for FGC. The 20% SFC substitution improved digestion of crude protein, yield of fat-corrected milk, milk lactose content, fat, and fat yield. The 40% SFC substitution increased urea concentration in both plasma and milk. It was concluded that 20% of SFC substitution for FGC appeared to be an appropriate level in diet for early lactation dairy cows.

  2. Effects of Xylan Side-Chain Substitutions on Xylan-Cellulose Interactions and Implications for Thermal Pretreatment of Cellulosic Biomass.

    PubMed

    Pereira, Caroline S; Silveira, Rodrigo L; Dupree, Paul; Skaf, Munir S

    2017-04-10

    Lignocellulosic biomass is mainly constituted by cellulose, hemicellulose, and lignin and represents an important resource for the sustainable production of biofuels and green chemistry materials. Xylans, a common hemicellulose, interact with cellulose and often exhibit various side chain substitutions including acetate, (4-O-methyl) glucuronic acid, and arabinose. Recent studies have shown that the distribution of xylan substitutions is not random, but follows patterns that are dependent on the plant taxonomic family and cell wall type. Here, we use molecular dynamics simulations to investigate the role of substitutions on xylan interactions with the hydrophilic cellulose face, using the recently discovered xylan decoration pattern of the conifer gymnosperms as a model. The results show that α-1,2-linked substitutions stabilize the binding of single xylan chains independently of the nature of the substitution and that Ca(2+) ions can mediate cross-links between glucuronic acid substitutions of two neighboring xylan chains, thus stabilizing binding. At high temperature, xylans move from the hydrophilic to the hydrophobic cellulose surface and are also stabilized by Ca(2+) cross-links. Our results help to explain the role of substitutions on xylan-cellulose interactions, and improve our understanding of the plant cell wall architecture and the fundamentals of biomass pretreatments.

  3. Heat treatment effects on structural and dielectric properties of Mn substituted CuFe2O4 and ZnFe2O4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Ranjith Kumar, E.; Arunkumar, T.; Prakash, T.

    2015-09-01

    Manganese substituted copper and zinc ferrite nanoparticles were synthesized by an auto-combustion technique using metal nitrates and urea. The nanoparticles were characterized by XRD, SEM, EDX, and TEM techniques. The effect of annealing temperature on structural and dielectric properties of Mn substituted spinel ferrite nanoparticles was analyzed. The presenting elements in the prepared samples are recorded by EDX. TEM analysis clearly showed the particles are in the nanometer range. The dielectric loss and dielectric constant have been measured in the frequency range of 100 kHz-5 MHz. The variation in structural and dielectric properties of the prepared and annealed samples are discussed.

  4. Genome-wide detection of allelic gene expression in hepatocellular carcinoma cells using a human exome SNP chip.

    PubMed

    Park, Yon Mi; Cheong, Hyun Sub; Lee, Jong-Keuk

    2014-11-10

    Allelic variations in gene expression influence many biological responses and cause phenotypic variations in humans. In this study, Illumina Human Exome BeadChips containing more than 240,000 single nucleotide polymorphisms (SNPs) were used to identify changes in allelic gene expression in hepatocellular carcinoma cells following lipopolysaccharide (LPS) stimulation. We found 17 monoallelically expressed genes, 58 allelic imbalanced genes, and 7 genes showing allele substitution. In addition, we also detected 33 differentially expressed genes following LPS treatment in vitro using these human exome SNP chips. However, alterations in allelic gene expression following LPS treatment were detected in only three genes (MLXIPL, TNC, and MX2), which were observed in one cell line sample only, indicating that changes in allelic gene expression following LPS stimulation of liver cells are rare events. Among a total of 75 genes showing allelic expression in hepatocellular carcinoma cells, either monoallelic or imbalanced, 43 genes (57.33%) had expression quantitative trait loci (eQTL) data, indicating that high-density exome SNP chips are useful and reliable for studying allelic gene expression. Furthermore, most genes showing allelic expression were regulated by cis-acting mechanisms and were also significantly associated with several human diseases. Overall, our study provides a better understanding of allele-specific gene expression in hepatocellular carcinoma cells with and without LPS stimulation and potential clues for the cause of human disease due to alterations in allelic gene expression.

  5. SNP-based large-scale identification of allele-specific gene expression in human B cells.

    PubMed

    Song, Min-Young; Kim, Hye-Eun; Kim, Sun; Choi, Ick-Hwa; Lee, Jong-Keuk

    2012-02-10

    Polymorphism and variations in gene expression provide the genetic basis for human variation. Allelic variation of gene expression, in particular, may play a crucial role in phenotypic variation and disease susceptibility. To identify genes with allelic expression in human cells, we genotyped genomic DNA and cDNA isolated from 31 immortalized B cell lines from three Centre d'Etude du Polymorphisme Humain (CEPH) families using high-density single-nucleotide polymorphism (SNP) chips containing 13,900 exonic SNPs. We identified seven SNPs in five genes with monoallelic expression, 146 SNPs in 125 genes with allelic imbalance in expression with preferentially higher expression of one allele in a heterozygous individual. The monoallelically expressed genes (ERAP2, MDGA1, LOC644422, SDCCAG3P1 and CLTCL1) were regulated by cis-acting, non-imprinted differential allelic control. In addition, all monoallelic gene expression patterns and allelic imbalances in gene expression in B cells were transmitted from parents to offspring in the pedigree, indicating genetic transmission of allelic gene expression. Furthermore, frequent allele substitution, probably due to RNA editing, was also observed in 21 genes in 23 SNPs as well as in 48 SNPs located in regions containing no known genes. In this study, we demonstrated that allelic gene expression is frequently observed in human B cells, and SNP chips are very useful tools for detecting allelic gene expression. Overall, our data provide a valuable framework for better understanding allelic gene expression in human B cells.

  6. Effects of Mn Substitution on the Thermoelectric Properties and Thermal Excitations of the Electron-doped Perovskite Sr1-xLaxTiO3

    NASA Astrophysics Data System (ADS)

    Okuda, Tetsuji; Hata, Hiroto; Eto, Takahiro; Sobaru, Shogo; Oda, Ryosuke; Kaji, Hiroki; Nishina, Kousuke; Kuwahara, Hideki; Nakamura, Mitsutaka; Kajimoto, Ryoichi

    2016-09-01

    We studied how Mn substitution affects the thermoelectric properties and thermal excitations of the electron-doped perovskite Sr1-xLaxTiO3 by measuring its electrical and thermal transport properties, magnetization, specific heat, and inelastic neutron scattering. Slight Mn substitution with the lattice defects enhanced the Seebeck coefficient, perhaps because of coupling between itinerant electrons and localized spins or between itinerant electrons and local lattice distortion around Mn3+ ions, while it enhanced anharmonic lattice vibrations, which effectively suppressed thermal conductivity in a state of high electrical conductivity. Consequently, slight Mn substitution increased the dimensionless thermoelectric figure of merit for Sr1-xLaxTiO3 near room temperature.

  7. Effects of substituted dithiocarbamates on distribution and excretion of inorganic mercury in mice

    SciTech Connect

    Gale, G.R.; Atkins, L.M.; Smith, A.B.; Jones, M.M.

    1985-02-01

    Diethyldithiocarbamate (DDTC) and six of its N,N-disubstituted congeners were evaluated for their relative efficacies in mobilizing and promoting excretion of mercury (Hg/sup + +/) using mice which had been given /sup 203/Hg/sup + +/; D-penicillamine (PEN) was used as a positive control compound. While none was as effective as PEN when compared on a molar dose basis, significant activity as assessed by reduction of whole body /sup 203/Hg burden, was observed following treatment with three of the analogs. The order of effectiveness was PEN greater than N-methyl-N-dithiocarboxyglucamine (MDCG) greater than di(carboxymethyl)dithiocarbamate (DCDC) greater than di(hydroxyethyl)dithiocarbamate (DHDC).

  8. Effects of 7-O substitutions on estrogenic and anti-estrogenic activities of daidzein analogues in MCF-7 breast cancer cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Daidzein (1) is a natural estrogenic isoflavone. We report here that 1 can be transformed into an antiestrogenic ligand by simple alkyl substitutions of the 7-hydroxyl hydrogen. To test the effect of such structural modifications on the hormonal activities of the resulting compounds, a series of dai...

  9. The Study of Substitution and Elimination Reactions Using Gas Chromatography: An Examination of the Effects of Alkane and Base Structure on Product Distributions

    ERIC Educational Resources Information Center

    Wharry, Donald L.

    2011-01-01

    An experiment that compares product distribution obtained by either substitution or elimination utilizing alkyl bromides and methoxide, ethoxide, or t-butoxide as the base (or nucleophile) is described. The change in product distribution caused by steric effects of the base and substrate are readily apparent. Prior work on this experiment focused…

  10. 40 CFR Appendix I to Subpart G of... - Substitutes Subject to Use Restrictions, Listed in the April 26, 2000, Final Rule, Effective May...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Final Rule, Effective May 26, 2000 Fire Suppression and Explosion Protection—Streaming Agents End Use Substitute Decision Limitations Comments Halon 1211 Streaming Agents HCFC Blend E Acceptable Nonresidential uses only As with other streaming agents, EPA recommends that potential risks of combustion...

  11. 40 CFR Appendix I to Subpart G of... - Substitutes Subject to Use Restrictions, Listed in the April 26, 2000, Final Rule, Effective May...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Final Rule, Effective May 26, 2000 Fire Suppression and Explosion Protection—Streaming Agents End Use Substitute Decision Limitations Comments Halon 1211 Streaming Agents HCFC Blend E Acceptable Nonresidential uses only As with other streaming agents, EPA recommends that potential risks of combustion...

  12. 40 CFR Appendix I to Subpart G of... - Substitutes Subject to Use Restrictions, Listed in the April 26, 2000, Final Rule, Effective May...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Final Rule, Effective May 26, 2000 Fire Suppression and Explosion Protection—Streaming Agents End Use Substitute Decision Limitations Comments Halon 1211 Streaming Agents HCFC Blend E Acceptable Nonresidential uses only As with other streaming agents, EPA recommends that potential risks of combustion...

  13. 40 CFR Appendix I to Subpart G of... - Substitutes Subject to Use Restrictions, Listed in the April 26, 2000, Final Rule, Effective May...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Final Rule, Effective May 26, 2000 Fire Suppression and Explosion Protection—Streaming Agents End Use Substitute Decision Limitations Comments Halon 1211 Streaming Agents HCFC Blend E Acceptable Nonresidential uses only As with other streaming agents, EPA recommends that potential risks of combustion...

  14. 40 CFR Appendix I to Subpart G of... - Substitutes Subject to Use Restrictions, Listed in the April 26, 2000, Final Rule, Effective May...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Final Rule, Effective May 26, 2000 Fire Suppression and Explosion Protection—Streaming Agents End Use Substitute Decision Limitations Comments Halon 1211 Streaming Agents HCFC Blend E Acceptable Nonresidential uses only As with other streaming agents, EPA recommends that potential risks of combustion...

  15. A simulation study of the potenial effects of healthy food and beverage substitutions on diet quality and total energy intake in lower Mississippi Delta adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of adult diets in the United States, particularly the South, are of poor quality, putting these individuals at increased risk for chronic diseases. In this study, simulation modeling was used to determine the effects of substituting familiar, more healthful foods and beverages for less...

  16. 40 CFR Appendix F to Subpart G of... - Unacceptable Substitutes Listed in the January 26, 1999 Final Rule, Effective January 26, 1999

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Unacceptable Substitutes Listed in the January 26, 1999 Final Rule, Effective January 26, 1999 F Appendix F to Subpart G of Part 82 Protection of... OZONE Significant New Alternatives Policy Program Pt. 82, Subpt. G, App. F Appendix F to Subpart G...

  17. 40 CFR Appendix F to Subpart G of... - Unacceptable Substitutes Listed in the January 26, 1999 Final Rule, Effective January 26, 1999

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Unacceptable Substitutes Listed in the January 26, 1999 Final Rule, Effective January 26, 1999 F Appendix F to Subpart G of Part 82 Protection of... OZONE Significant New Alternatives Policy Program Pt. 82, Subpt. G, App. F Appendix F to Subpart G...

  18. Can Animations Effectively Substitute for Traditional Teaching Methods? Part I: Preparation and Testing of Materials

    ERIC Educational Resources Information Center

    Gregorius, Roberto Ma.; Santos, Rhodora; Dano, Judith B.; Gutierrez, Jose J.

    2010-01-01

    Two animations, one focused on the macroscopic phenomena and particulate conception of the three states of matter and the effects of heat on these states, and the other on solution formation and solubility were produced using Adobe Flash MX software. The first was designed for and tested on elementary school (3rd-5th grade) students. The second…

  19. The effect of isotopic substitution on diffusion coefficients in silicate liquids

    NASA Astrophysics Data System (ADS)

    Watkins, J. M.; Depaolo, D. J.; Ryerson, F. J.

    2009-12-01

    We are using diffusion couple experiments to measure the relative diffusion coefficients of Ca isotopes in silicate liquids, and any dependence on silicate liquid composition. Isotopic signatures due to kinetic effects are increasingly recognized as being important in geological processes; however, there is no general theory for the mass dependence of diffusion coefficients in liquids. Chemical diffusion of major elements (Fe, Mg, Ca, and Li) in basalt-rhyolite and ugandite-rhyolite diffusion couple experiments produces isotopic fractionations in which the mass discrimination during diffusion (i.e., the isotope effect) is much greater for Li than it is for Fe, Mg, and Ca. In these natural liquids, the diffusivity of Fe, Mg, and Ca is similar to that of Si (Dcation/DSi≈1) whereas that of Li is much greater (DLi/DSi≈500). These experiments also show that the isotope effect, at least for Ca, is sensitive to slight changes in composition and therefore difficult to predict or generalize beyond the experimental conditions. However, the few experiments that have been conducted on silicate liquids provide an indication that the mobility of the cation relative to the liquid matrix (Dcation/DSi) correlates with the strength of the isotope effect. To further test this hypothesis, we conducted experiments using synthetic, simplified compositions in which Ca diffuses rapidly with respect to Si. Our diffusion couples consist of starting liquids that lie along the joins of albite-anorthite (ABAN) and albite-diopside (ABDI). In both experiments, albite is the main component of the liquid. In the ABAN experiment, DCa/DSi≈20 and the strength of the isotope effect for Ca is much greater than in the natural liquid experiments where DCa/DSi≈1. In the ABDI experiment, DCa/DSi≈6 and the strength of the isotope effect is between that of the natural liquid experiments and the ABAN experiment. For the ABDI experiment, we will present additional isotopic results for Mg, a cation

  20. Analyses of Allele-Specific Gene Expression in Highly Divergent Mouse Crosses Identifies Pervasive Allelic Imbalance

    PubMed Central

    Crowley, James J; Zhabotynsky, Vasyl; Sun, Wei; Huang, Shunping; Pakatci, Isa Kemal; Kim, Yunjung; Wang, Jeremy R; Morgan, Andrew P; Calaway, John D; Aylor, David L; Yun, Zaining; Bell, Timothy A; Buus, Ryan J; Calaway, Mark E; Didion, John P; Gooch, Terry J; Hansen, Stephanie D; Robinson, Nashiya N; Shaw, Ginger D; Spence, Jason S; Quackenbush, Corey R; Barrick, Cordelia J; Nonneman, Randal J.; Kim, Kyungsu; Xenakis, James; Xie, Yuying; Valdar, William; Lenarcic, Alan B; Wang, Wei; Welsh, Catherine E; Fu, Chen-Ping; Zhang, Zhaojun; Holt, James; Guo, Zhishan; Threadgill, David W; Tarantino, Lisa M; Miller, Darla R; Zou, Fei; McMillan, Leonard; Sullivan, Patrick F; de Villena, Fernando Pardo-Manuel

    2015-01-01

    Complex human traits are influenced by variation in regulatory DNA through mechanisms that are not fully understood. Since regulatory elements are conserved between humans and mice, a thorough annotation of cis regulatory variants in mice could aid in this process. Here we provide a detailed portrait of mouse gene expression across multiple tissues in a three-way diallel. Greater than 80% of mouse genes have cis regulatory variation. These effects influence complex traits and usually extend to the human ortholog. Further, we estimate that at least one in every thousand SNPs creates a cis regulatory effect. We also observe two types of parent-of-origin effects, including classical imprinting and a novel, global allelic imbalance in favor of the paternal allele. We conclude that, as with humans, pervasive regulatory variation influences complex genetic traits in mice and provide a new resource toward understanding the genetic control of transcription in mammals. PMID:25730764

  1. Chemical Substitution and High Pressure Effects on Superconductors in the LnOBiS$$_2$$ (Ln = La-Nd) System

    DOE PAGES

    Fang, Yuankan; Wolowiec, Christian T.; Yazici, Duygu; ...

    2015-12-14

    A large number of compounds which contain BiSmore » $$_2$$ layers exhibit enhanced superconductivity upon electron doping. Much interest and research effort has been focused on BiS$$_2$$-based compounds which provide new opportunities for exploring the nature of superconductivity. Important to the study of BiS2-based superconductors is the relation between structure and superconductivity. By modifying either the superconducting BiS$$_2$$ layers or the blocking layers in these layered compounds, one can effectively tune the lattice parameters, local atomic environment, electronic structure, and other physical properties of these materials. In this article, we will review some of the recent progress on research of the effects of chemical substitution in BiS$$_2$$-based compounds, with special attention given to the compounds in the LnOBiSS$$_2$$ (Ln = La-Nd) system. Strategies which are reported to be essential in optimizing superconductivity of these materials will also be discussed.« less

  2. Effects of substitutional impurity Au and Si atoms on antiphase boundary energies in Ti3Al: A first principles study

    NASA Astrophysics Data System (ADS)

    Koizumi, Yuichiro; Mizuno, Masataka; Sugihara, Atsushi; Minamino, Yoritoshi; Shirai, Yasuharu

    2010-10-01

    Effects of substitutional impurity atoms Au and Si on the energies of antiphase boundaries (APBs) on {1overline 1 00} and (0001) planes in a Ti3Al intermetallic compound were examined using first principles calculations. Au additions reduce the energies of APBs on both {1overline 1 00} and (0001) planes by up to more than 40%. The reduction tends to be more remarkable especially when the added Au atom has larger number of Al atoms on its second-nearest neighbor sites rather than on first-nearest neighbor ones. In addition, in the case of Si addition, a significant energy reduction was found only for APBs on (0001) planes, and no remarkable dependence of APB energies on the coordinating atoms was found even for APBs on (0001) planes. These results are crucial to both understanding of the effect of APBs on the impurity diffusivity and predicting the ability of impurity atoms to stabilize antiphase domain structure that increases the strength of Ti3Al dramatically.

  3. Economic effects of immigrants on native and foreign-born workers: complementarity, substitutability, and other channels of influence.

    PubMed

    Greenwood, M J; Hunt, G L

    1995-04-01

    The authors use Standard Metropolitan Statistical Area (SMSA) data constructed from 1980 census microdata files and other sources to estimate a structural model of native/foreign-born labor demand and labor supply which distinguishes the effects upon real wages of each type of labor and on the employment of natives. The authors specify, econometrically estimate, and simulate the structural model which incorporates not only a production structure channel through which immigrants influence area real wages and employment, but also demand and native labor supply channels. It is noted that while these are not the only channels through which immigrants may affect native workers, the model nonetheless constitutes a step in the direction of a general equilibrium approach. In the production structure channel, immigrants and natives are found to be substitutes in production. Immigration lowers foreign-born wage rates and leads to lower wages for natives. The negative effects of the production channel usually are ameliorated through the demand channel. Further, immigrants add to local demand through their earnings and potentially through non-labor income, while also lowering unit costs and local prices which enhances real incomes and potentially net exports, and thus the demands for local output and area labor. The author discusses findings of interest from the simulation results based upon an analysis of all areas.

  4. Effects of sodium substitutes on transient inward current and tension in guinea-pig and ferret papillary muscle.

    PubMed

    Arlock, P; Katzung, B G

    1985-03-01

    We used ouabain-treated guinea-pig and ferret papillary muscles to study transient inward current (Iti), after-contractions, and tonic tension development during voltage-clamp pulses. Li, sucrose and choline were used isosmotically as Na substitutes to evaluate the effect of altering the Na equilibrium potential. We were unable to detect outward Iti at any potential up to +30 mV in normal or Na-depleted solutions. However, reduction of Na had a biphasic effect on Iti, initially increasing it and then reducing it at all clamp potentials from -50 to +20 mV. After-contractions were also initially increased and, in sufficiently Na-depleted solutions, decreased by reduction of extracellular Na. However, the peak in the after-contraction always occurred later than the increase in Iti and frequently coincided with the maximum suppression of the current. Complete suppression of after-contractions was not often achieved and always required more complete Na replacement than Iti suppression. Tonic tension responses were reduced by Na replacement, usually in synchrony with the reduction of Iti. The responses of Iti to Na replacement are consistent with a model of electrogenic Na-Ca exchange over the potential range positive to -50 mV. The responses deviate from the predictions of the model at more negative potentials. The results are consistent with the previous proposal that oscillatory changes in internal free Ca concentration underlie both Iti and after-contractions.

  5. A novel HLA-B*51 allele, HLA-B*5149.

    PubMed

    Endres, R O; Redman, H; Scavello, G S

    2007-09-01

    Discovery of the novel HLA-B*5149 allele in a North American Caucasian individual is described. It differs from B*510101 by one nucleotide within the coding sequence of exons 1-6. A substitution at nucleotide position 488 in exon 3 changes alanine to glycine in amino acid position 139.

  6. HLA-B*152703, a novel allele, which has arisen by silent mutation in codon 138.

    PubMed

    Zou, H-Y; Li, Z; Cheng, L-H; Jin, S-Z; Deng, Z-H

    2008-10-01

    A novel human leukocyte antigen-B (HLA-B) allele, officially named B*152703, was found during routine high-resolution sequence-based typing in a Chinese potential hematopoietic stem cell transplantation donor. Compared with the HLA-B*152701 sequence, the B*152703 has a silent substitution at position 486(G-->C) in exon 3.

  7. Effect of Temperature on Viscosity of S-Substituted Triazinothiocarbamides in 60% Dioxane Water Mixture

    NASA Astrophysics Data System (ADS)

    Kshirsagar, A. M.; Tayade, D. T.

    2012-10-01

    S-triazine and thiocarbamide group containing drug create their own identity in the drug, pharmaceutical and medicinal sciences in last four decades. Hence, the viscometric measurements of recently synthesized drugs viz. 1-(4-hydroxy-6-methyl)-S-triazino-3-phenylthiocarbamide (L1) and 1-(4-hydroxy-6-methyl)-S-triazino-3-methylthiocarbamide (L2), were carried out at 60% various percentage of solvent to investigate effect of structure, on group of S-triazinothiocarbamides. The result obtained during this investigation directly through light on the dipole association of compound, intermolecular attraction between solute and solvent, dielectric constant of medium, polarizability and mutual compensation of dipoles and useful for drug absorption, transmission, stability, activity and effect of drug. %K 1-(4-hydroxy-6-methyl)-S-triazino-3-phenylthiocarbamide (L1) and 1-(4-hydroxy-6-methyl)-S-triazino-3-methylthiocarbamide (L2), dioxane-water mixture, viscometric measurements.

  8. Second-order nonlinear optical properties of dithienophenazine and TTF derivatives: A butterfly effect of dimalononitrile substitutions.

    PubMed

    Muhammad, Shabbir

    2015-06-01

    Using density functional theory (DFT) methods, the nonlinear optical (NLO) properties have been calculated with strong donor-π-conjugation-acceptor configurations. The static first hyperpolarizability (β0) and dynamic (frequency dependent) electric field induced second harmonic generation (EFISHG) first hyperpolarizability (μβ) are calculated for all designed systems. Our DFT calculations show dithienophenazine merged TTF (2) holds larger β0 amplitudes (β0=21.04×10(3)a.u.) as compared to its corresponding compounds of TTF merged-difurophenazine (1), dicyclopentaphenazine (3) and dipyrrolophenazine (4) derivatives having β0 amplitudes of 16.25×10(3), 12.69×10(3), and 18.38×10(3)a.u., respectively. Furthermore, substitution of dimalononitrile [C(CN)2]2 groups at acceptor end of these compounds results in new derivatives 1a-4a, respectively. Interestingly, a butterfly effect on first hyperpolarizability of all systems 1a-4a has been spotted, which not only results in their robustly larger β0 amplitudes but also changes the increasing order of β0 amplitudes from systems 3<1<4<2 to 1a<2a<3a<4a at both PBE0/6-31G* and CAM-B3LYP/6-31+G* levels of theory. For example, the increase in β0 amplitudes of systems 1a, 2a, 3a and 4a are 3, 3, 5, and 19 times as compared with their corresponding non dimalononitrile derivatives at PBE0/6-31G* level of theory, respectively. Remarkably, unlike the static first hyperpolarizability, the dynamic EFISHG hyperpolarizability (μβω) has the largest value for system 4a with its amplitudes of 1378.59×10(-46) and 1349.40×10(-46)esu, at PBE0/6-31G* and CAM-B3LYP/6-31+G* levels of theory, respectively. TD-DFT calculations have been performed to trace the origin of first hyperpolarizability. It has been found that the lower transition energy and higher oscillator strengths cause robustly large amplitudes especially in systems 3a and 4a, which consequently stems in strong donor-π-conjugation-acceptor configuration of these

  9. Effect of uniaxial stress on substitutional Ni in ZnO

    NASA Astrophysics Data System (ADS)

    Lavrov, E. V.; Herklotz, F.; Kutin, Y. S.

    2013-04-01

    The influence of uniaxial stress on the electronic T13(F)→T23(F) transitions of Ni (d8) in ZnO at 4216, 4240, and 4247 cm-1 is studied. It is shown that the split pattern and polarized properties of IR absorption lines are consistent with a dynamic Jahn-Teller effect in the T23(F) state of the defect.

  10. Auxin Activity of Substituted Benzoic Acids and Their Effect on Polar Auxin Transport 1

    PubMed Central

    Keitt, George W.; Baker, Robert A.

    1966-01-01

    Six dichloro-, 3 trichloro-, 2 triiodo-, and 3 heterosubstituted benzoic acids (amiben, dinoben, dicamba), and N-1-naphthylphthalamic acid have been tested for effects on growth and on polar auxin transport. Growth activity with and without kinetin was measured by effects on fresh and dry weights of 30-day cultures of fresh tobacco pith. Transport inhibition was measured by following uptake and output of IAA-2-14C through 10 mm bean epicotyl sections. The distribution of callus growth on vascularized tobacco stem segments was also observed. Avena first internode extension assays established the relative activities: dicamba > amiben > dinoben suggested by pith growth results. Growth effects of active compounds were similar with and without kinetin, except that amiben was less active with kinetin, while 2,3,6-trichlorobenzoic acid was more active with kinetin than alone. The weak auxin activity of NPA was confirmed. Transport experiments showed that NPA was the most inhibitory compound tested, followed by TIBA. Other compounds tested were at least 300 times less inhibitory to IAA transport. The best growth promoters were the least inhibitory to transport, and the most effective transport inhibitors were at best poor auxins. It is suggested that the weak auxin and auxin synergistic activity of TIBA (and perhaps 2,3-dichlorobenzoic acid) in extension growth tests arises from its inhibition of transport of endogenous or added auxin out of the sections, rather than from its intrinsic auxin activity. Chemically induced apolar callus growth on vascularized tobacco stem explants can arise from inhibition of native auxin transport, apolar growth stimulation by auxinic action of the test compound, or both. PMID:16656441

  11. Cooperative and substitution effects in enhancing strengths of halogen bonds in FCl⋯CNX complexes

    NASA Astrophysics Data System (ADS)

    Li, Qingzhong; Ma, Shumin; Liu, Xiaofeng; Li, Wenzuo; Cheng, Jianbo

    2012-08-01

    In this paper, the cooperative effect of halogen bond with hydrogen bond has been used to make a halogen bond in FCl-CNH dimer vary from a chlorine-shared one to an ion-pair one. The halogen bond is strengthened in FCl-CNH-CNH trimer and its maximal interaction energy equals to -76 kJ/mol when the number of CNH in FCl-CNH-(CNH)n polymer approaches infinity. Once the free H atom in FCl-CNH-CNH trimer is replaced with alkali metals, the halogen bond becomes strong enough to be an ion-pair one in FCl-CNH-CNLi and FCl-CNH-CNNa trimers. An introduction of a Lewis acid in FCl-CNH dimer has a more prominent effect on the type of halogen bond. A prominent cooperative effect is found for the halogen bond and hydrogen bond in the trimers. FH-FCl-CNH-CNH and FH-FCl-CNH-CNLi tetramers have also been studied and the interaction energy of halogen bonding in FH-FCl-CNH-CNLi tetramer is about 12 times as much as that in the FCl-CNH dimer. The atoms in molecules and natural bond orbital analyses have been carried out for these complexes to understand the nature of halogen bond and the origin of the cooperativity.

  12. Allele Mining Strategies: Principles and Utilisation for Blast Resistance Genes in Rice (Oryza sativa L.).

    PubMed

    Ashkani, Sadegh; Yusop, Mohd Rafii; Shabanimofrad, Mahmoodreza; Azady, Amin; Ghasemzadeh, Ali; Azizi, Parisa; Latif, Mohammad Abdul

    2015-01-01

    Allele mining is a promising way to dissect naturally occurring allelic variants of candidate genes with essential agronomic qualities. With the identification, isolation and characterisation of blast resistance genes in rice, it is now possible to dissect the actual allelic variants of these genes within an array of rice cultivars via allele mining. Multiple alleles from the complex locus serve as a reservoir of variation to generate functional genes. The routine sequence exchange is one of the main mechanisms of R gene evolution and development. Allele mining for resistance genes can be an important method to identify additional resistance alleles and new haplotypes along with the development of allele-specific markers for use in marker-assisted selection. Allele mining can be visualised as a vital link between effective utilisation of genetic and genomic resources in genomics-driven modern plant breeding. This review studies the actual concepts and potential of mining approaches for the discovery of alleles and their utilisation for blast resistance genes in rice. The details provided here will be important to provide the rice breeder with a worthwhile introduction to allele mining and its methodology for breakthrough discovery of fresh alleles hidden in hereditary diversity, which is vital for crop improvement.

  13. Effect of mineral additives (natural pozzolana and sand of dunes) by substitution of cement on the performance and durability of mortars

    NASA Astrophysics Data System (ADS)

    Saidi, M.; Safi, B.

    2016-04-01

    The objective of our work consists of the study of the substitution effects of clinker by mineral additions such as: natural pozzolana (PZ) and the sand of dunes (SD) finely crushed on the mechanical properties and the durability of the mortars worked out according to various combinations containing these additions. The results from this research confirm that the substitution of 20% to 30% of cement APC (Artificial Portland Cement) by additions in binary cement (APC + PZ) or ternary (APC + PZ + SD) contributes positively to the mechanical strength of mortars and resistance to the chemical attacks in various corrosive conditions such as: hydrochloric acid, sulfuric acid and nitric acid. The mechanical strength of the different variants is comparable to those of the APC. The test results of the weight loss and phenolphthalein shows that the chemical resistance of variants (PZ20) and (PZ20 with SD5) are larger compared to the reference mortar APC and other variants. This study shows that adding value by substituting a part of clinker. This substitution can save 20% to 30% of clinker used for the manufacture of cement; this will have a beneficial effect for cement and economically (less energy spent for the clinker burning). This study contributes to the protection of the environment as to produce one ton of clinker generates about one ton of CO2 is harmful to the atmosphere. Based on our results we will reduce from 20% to 30% CO2 gas responsible for the greenhouse effect.

  14. Effects of Sc and Y substitution on the structure and thermoelectric properties of Yb14MnSb11

    NASA Astrophysics Data System (ADS)

    Grebenkemper, Jason H.; Klemenz, Sebastian; Albert, Barbara; Bux, Sabah K.; Kauzlarich, Susan M.

    2016-10-01

    Yb14MnSb11 is the most efficient bulk p-type thermoelectric material for high temperature applications. Materials with Y and Sc substitutions in Yb14MnSb11 were made both in Sn-flux and by ball milling. These small 3+ rare earth (RE) cations were introduced with the goal of providing chemical pressure on the structure. The RE3+ cation is smaller than Yb2+ and also donates one additional electron to this p-type semiconductor. In Yb14-xRExMnSb11 (RE = Sc, Y) the maximum x was about 0.5. X-ray diffraction experiments on the single crystals obtained from Sn-flux showed that Sc preferentially substitutes for Yb(1) and Yb(3), and decreases the size of the unit cell by about 0.3%. Y substitutes on all Yb sites and increases the size of the unit cell by about 0.2%. Samples with Yb14-xRExMnSb11 (x~0.3) were prepared via powder metallurgy and spark plasma sintering for transport and thermal conductivity measurements. Electron microprobe of the Sc-substituted sample showed small regions (≤1 μ m) containing greater amounts of Sc, and X-ray powder diffraction of the ball milled Sc sample could be fitted as phase pure Yb14-xScxMnSb11. Y-substituted samples showed larger regions of excess Y in electron microprobe, and small amounts of Yb4Sb3 in X-ray powder diffraction. The Sc sample has slightly reduced carrier concentration over optimized Yb14MnSb11, while the Y samples have even lower carrier concentrations. These carrier concentrations lead to comparable resistivity to Yb14MnSb11 in the Sc-substituted material, and higher resistivities in the Y-substituted material. All materials had similar Seebeck coefficients that slightly exceed Yb14MnSb11 at high temperatures, with the Sc-substituted sample having the highest despite having a higher carrier concentration. Sc-substituted samples also had a slightly higher thermal conductivity over the Y-substituted samples, which had comparable thermal conductivity to Yb14MnSb11. The zT values of the Sc and Y substituted samples are

  15. Life satisfaction in the new country: a multilevel longitudinal analysis of effects of culture and 5-HTT allele frequency distribution in country of origin.

    PubMed

    Kashima, Emiko S; Kent, Stephen; Kashima, Yoshihisa

    2015-01-01

    Life satisfaction of migrants to Australia from 17 countries, assessed at 4-5 months, 16-17 months and 3½ years after arrival, was analyzed with a longitudinal, multilevel analysis. The results indicated that migrants were more satisfied, if the national average life satisfaction was higher in their country of origin, after adjustment for individual-level income, age, and sex and a linear temporal trend. Simultaneously, the migrants were also happier if people in their country of origin had a higher frequency of 5-HTT long allele, a genotype known to be associated with resilience under life stresses. These two relationships were independent, suggesting that both culture and gene matter in international transitions.

  16. Life satisfaction in the new country: a multilevel longitudinal analysis of effects of culture and 5-HTT allele frequency distribution in country of origin

    PubMed Central

    Kent, Stephen; Kashima, Yoshihisa

    2015-01-01

    Life satisfaction of migrants to Australia from 17 countries, assessed at 4–5 months, 16–17 months and 3½ years after arrival, was analyzed with a longitudinal, multilevel analysis. The results indicated that migrants were more satisfied, if the national average life satisfaction was higher in their country of origin, after adjustment for individual-level income, age, and sex and a linear temporal trend. Simultaneously, the migrants were also happier if people in their country of origin had a higher frequency of 5-HTT long allele, a genotype known to be associated with resilience under life stresses. These two relationships were independent, suggesting that both culture and gene matter in international transitions. PMID:24532702

  17. Prevalence of CYP2C19 alleles, pharmacokinetic and pharmacodynamic variation of clopidogrel and prasugrel in Bangladeshi population.

    PubMed

    Bin Sayeed, Muhammad Shahdaat; Hasan Apu, Mohd Nazmul; Munir, Maliha Tabassum; Ahmed, Maizbha Uddin; Islam, Mohammad Safiqul; Haq, M Maksumul; Ahsan, Chowdhury H; Rashid, M A; Shin, Jae Gook; Hasnat, Abul

    2015-05-01

    The extent to which cytochrome P450 (CYP) 2C19 genotype influences the effectiveness of clopidogrel remains uncertain due to considerable heterogeneity between studies. We used the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method for genotyping loss of function (LOF) allele, CYP2C19*2 and gain of function (GOF) allele, CYP2C19*17 in 163 patients undergoing PCI and 165 healthy volunteers from an ethnically distinctive Bangladeshi population. Thirty-eight patients took prasugrel and 125 patients took clopidogrel among whom 30 patients had their clopidogrel active metabolites (CAM) determined by LC-MS/MS 1-1.5 h after clopidogrel intake. All patients who underwent PCI had their P2Y12 per cent inhibition (PRI) measured by VerifyNow System. The impact of different genotypes on CAM and PRI were also determined. We did not find significant variation of CYP2C19*2 (P > 0.05) and CYP2C9*17 (P > 0.05) alleles among healthy volunteers and patients. CAM concentration as well as PRI by clopidogrel varied significantly (P < 0.05) based on genotypic variation of CYP2C19*2 and CYP2C19*17 individually. Such influence was not observed in case of prasugrel. Genotypic variation did not impact PRI but as a whole PRI by prasugrel was better than that of clopidogrel (P < 0.05). Due to presence of both of alleles the effect on PRI by clopidogrel could not be predicted, effectively indicating possible involvement of other factors. Genotype guided clopidogrel dose adjustment would be beneficial and therefore we propose mandatory genotyping before clopidogrel dosing. Prasugrel proved to be less affected by genotypic variability, but due to lack of sufficient long-term toxicity data, caution would be adopted before substituting clopidogrel.

  18. Antimicrobial effect of para-alkoxyphenylcarbamic acid esters containing substituted N-phenylpiperazine moiety

    PubMed Central

    Malík, Ivan; Bukovský, Marián; Andriamainty, Fils; Gališinová, Jana

    2013-01-01

    In current research, nine basic esters of para-alkoxyphenylcarbamic acid with incorporated 4-(4-fluoro-/3-trifluoromethylphenyl)piperazin-1-yl fragment, 6i–6m and 8f–8i, were screened for their in vitro antimicrobial activity against Candida albicans, Staphylococcus aureus and Escherichia coli, respectively. Taking into account the minimum inhibitory concentration assay (MIC), as the most active against given yeast was evaluated 8i (MIC = 0.20 mg/mL), the most lipophilic structure containing para-butoxy and trifluoromethyl substituents. Investigating the efficiency of the compounds bearing only a single atom of fluorine and appropriate para-alkoxy side chain against Candida albicans, the cut-off effect was observed. From evaluated homological series, the maximum of the effectiveness was noticed for the stucture 6 k (MIC = 0.39 mg/mL), containing para-propoxy group attached to phenylcarbamoyloxy fragment, beyond which the compounds ceased to be active. On the contrary, all the tested molecules were against Staphylococcus aureus and Escherichia coli (MICs > 1.00 mg/mL) practically inactive. PMID:24294237

  19. Effect of temperature and substitution on Cope rearrangement: a symmetry perspective.

    PubMed

    Tuvi-Arad, Inbal; Rozgonyi, Tamás; Stirling, András

    2013-12-05

    Many reactions feature symmetry variation along the reaction path on the potential energy surface. The interconversion of the point group symmetry of the stationary points can be characteristic of these processes. Increasing the temperature, however, leads to the loss of symmetry in its traditional yes-no language. We find that in such cases the instantaneous distance of the molecular structure from its symmetric counterpart is a suitable collective variable that can describe the reaction process. We show that this quantity, the continuous symmetry measure (CSM), has a positive linear relationship with temperature, implying that even highly symmetric molecules should be considered as asymmetric above 0 K. Using ab initio molecular dynamics, we simulate the temperature-induced Cope rearrangements of several fluxional molecules and employ different CSMs to follow the reaction progress. We use this methodology to demonstrate the validity of important concepts governing these reactions: Woodward-Hoffmann rules and TS aromaticity. Statistical analysis of the CSM distributions reveals that ligands connected to the carbon frame have profound effect on the reaction course. In particular, our results show that lower temperatures tend to enhance the differences between the TS-stabilizing effect of the substituents.

  20. Neonatal, lethal noncompaction of the left ventricular myocardium is allelic with Barth syndrome.

    PubMed Central

    Bleyl, S B; Mumford, B R; Thompson, V; Carey, J C; Pysher, T J; Chin, T K; Ward, K

    1997-01-01

    Loss-of-function mutations in the G4.5 gene have been shown to cause Barth syndrome (BTHS), an X-linked disorder characterized by cardiac and skeletal myopathy, short stature, and neutropenia. We recently reported a family with a severe X-linked cardiomyopathy described as isolated noncompaction of the left ventricular myocardium (INVM). Other findings associated with BTHS (skeletal myopathy, neutropenia, growth retardation, elevated urinary organic acids, and mitochondrial abnormalities) were either absent or inconsistent. A linkage study of the X chromosome localized INVM to the Xq28 region near the BTHS locus, suggesting that these disorders are allelic. We screened the G4.5 gene for mutations in this family with SSCP and direct sequencing and found a novel glycine-to-arginine substitution at position 197. This position is conserved in a homologous Caenorhabditis elegans protein. We conclude that INVM is a severe allelic variant of BTHS with a specific effect on the heart. This finding provides further structure-function information about the G4.5 gene product and has implications for unexplained cases of severe infantile hypertrophic cardiomyopathy in males. Images Figure 2 PMID:9382097

  1. Carbicarb: an effective substitute for NaHCO3 for the treatment of acidosis.

    PubMed

    Sun, J H; Filley, G F; Hord, K; Kindig, N B; Bartle, E J

    1987-11-01

    Carbicarb (Na2CO3 0.33 molar NaHCO3 0.33 molar), a mixture formulated to avoid the objections to sodium bicarbonate therapy, has been compared with 1 mol/L NaHCO3 and 1 mol/L NaCl in the treatment of mixed respiratory and metabolic acidosis (pH 7.17) produced by asphyxia in rats. In clinically appropriate doses, intravenous NaHCO3 raised arterial pH only 0.03 unit, elevated arterial carbon dioxide pressure, and doubled lactate concentration. With Carbicarb, the pH rise was three times as great and the blood lactate level was unchanged. The new drug should be effective in treating the acidosis of cardiopulmonary failure without raising blood carbon dioxide pressure or lactate levels and at lower sodium doses than required for NaHCO3.

  2. Effects of organosilicon compounds, bearing molecular substitutions, on mouse liver glycogen

    SciTech Connect

    Gulley, C.

    1987-01-01

    This study was conducted to observe the effects of organosilicon compounds on the liver glycogen levels of Jax Albino mice. Tris(trimethylisilyl) methylcarboxylic acid, hexaphenyldisilane and tris(trimethylsilyl) bromomethane were fed to mice ad libitum in an organosilicon compound-laboratory chow mixture for 3 one week periods. At the ends of each period, the mice were sacrificed, their livers removed, glycogen was extracted, and subjected to acid hydrolysis. The concentration of free glucose units were determined using the 3,5 dinitrosalicylate reagent. Compared with the controls, tris(trimethylsilyl) methylcarboxylic acid caused a slight depletion of liver glycogen. Hexaphenyldisilane caused a greater depletion of the glycogen stores, and tris(trimethylsilyl) bromomethane caused the greatest depletion of the glycogen stores.

  3. Rotational effects in complex-forming bimolecular substitution reactions: A quantum-mechanical approach

    NASA Astrophysics Data System (ADS)

    Hennig, Carsten; Schmatz, Stefan

    2009-12-01

    The quantum dynamics of the complex-forming SN2 reaction Cl-+CH3Br→ClCH3+Br- is studied with emphasis on rotational effects. The pseudotriatomic system Cl-Me-Br is treated with a corresponding three-dimensional (3D) potential energy surface as a function of the two scattering coordinates and the enclosed angle where the geometry of the methyl group Me is optimized at each point. The 3D space is divided into three different parts, the interaction region, an intermediate region, and the asymptotic region. In line with simple classical-mechanical arguments and previous classical trajectory calculations, initial rotational motion of CH3Br seemingly decreases the reaction probability. However, the dynamical inclusion of the rotational degree of freedom and the presence of the many rovibrational product states overall lead to a large increase in reactivity compared to our previous collinear study on this reaction. If the reactant is rotationally excited, the higher vibrational product states are depleted in favor of lower-lying levels. Starting the reaction with rotationless reactants may end up in significant rotational excitation in the product molecules (translation-to-rotation energy transfer). On the other hand, initial rotational energy in rotationally highly excited reactants is to a large amount converted into translational and vibrational energy. The average amount of rotational energy in the products shows a twofold vibrational excitation-independent saturation (i.e., memorylessness), with respect to both initial rotational excitation and translational energy. Since only about one-half of all reactant states end in rotationless products, the reaction probability should be increased by a factor of 2; the actually larger reactivity points to other dynamical effects that play an important role in the reaction.

  4. Chemical pressure and other effects of strontium substitution in YBa 2Cu 3O 9-δ

    NASA Astrophysics Data System (ADS)

    Karen, P.; Fjellvåg, H.; Kjekshus, A.; Andresen, A. F.

    1991-05-01

    High quality samples of the Y(Ba 1- ySr y) 2Cu 3O 6.948(6) solid solution phase were prepared via citrate gels by mixing the components on an atomic level. The range of solid solubility is 0.00 ≤ y ≤ 0.35(3) for a 910°C firing temperature and constant oxygen content, as determined by iodometry. At standardized conditions, the limiting phase with y = 0.35(3) is in equilibrium with Y 2(Ba 0.9Sr 0.1)CuO 5 and (Sr, Y) 14Cu 24O 41, and the situation is described in terms of a tetrahedral four-component phase diagram. The slightly enhanced (anisotropic) contraction along the c axis of the unit cell, observed upon introduction of the smaller Sr atoms, is associated with apical compression of the coordination square pyramids of copper. Both the volume contraction and its anisotropy can be compared with the effects of applied pressure. In terms of chemical pressure P∗ = ɛ · y, coefficients of ɛV = 6.8(2) GPa or ɛDt = 2.4(4) GPa are obtained, depending on whether ɛ is deduced from unit cell volume V or its (tetragonal) distortion Dt. The responses of the superconducting state upon the applied and chemical pressure (the latter exerted at the Ba site) are, however, quite different, with {ΔT c}/{ΔP} = 0.7 K/GPa and {ΔT c}/{Δy} = -20(2) K. A specific feature must hence either be introduced by the real pressure (e.g., increase in carrier concentration) or by the chemical pressure [e.g., local strain effects and/or redistribution of oxygen around Cu(1) site].

  5. Identification of three new DRB3* (DRB3*0106, DRB3*0107 and DRB3*02022) alleles.

    PubMed

    Tavoularis, S; Ouellet, S; Stephens, S

    2001-04-01

    Three novel DRB3* alleles were identified using CANTYPE reverse hybridization assay. The initial unusual hybridization patterns of DRB3-specific polymerase chain reaction (PCR)-amplified DNA from each subject were confirmed by cloning and sequencing analysis. DRB3*0106 allele is identical to DRB3*0101 except for a single nucleotide substitution (CTG-->GTG) changing codon 38 from Leu to Val. This polymorphism is commonly found in DRB3*03 alleles. Compared with DRB3*0202, DRB3*02022 contains a single silent nucleotide substitution (AAT-->AAC, both encoding for Asn) at codon 77. This polymorphism is also present in DRB3*0204 allele. The new DRB3*0107 allele has a sequence unique to DRB3 alleles. From codon 5 to codon 36 the sequence is identical to that of DRB3*0101 allele. From codon 37 to codon 87 the sequence of DRB1*0107 allele is identical to that of DRB3*0202. This sequence would thus explain the CANTYPE(R) DRB3-specific unusual pattern of reactions. The new DRB3*0107 could have arisen from a gene conversion between DRB3*0101 and DRB3*0202 alleles, but the DRB3*0106 and the DRB3*02022 may have been generated by a point mutation event. The DRB3*0107 allele was identified in a Caucasoid individual. The ethnic origin of the subjects carrying the other two alleles are unknown. The three alleles presented here were only identified once, in a total population of 49,000.

  6. Effect of Cu substitution on the magnetic and dielectric properties of La2NiMnO6

    NASA Astrophysics Data System (ADS)

    Biswal, A. K.; Ray, J.; Babu, P. D.; Siruguri, V.; Vishwakarma, P. N.

    2015-05-01

    In the continuation of our previous work [Biswal et al., J. Appl. Phys. 115, 194106 (2014)] of biphasic La2NiMnO6 (LNM) prepared via sol-gel technique, here we are reporting the effect of Cu substitution at Ni site of LNM. The powder x-ray diffraction results of La2Ni1-xCuxMnO6 (x = 0, 0.05, 0.1) confirm the biphasic nature (Pbnm + R-3c) for all samples along with increasing R-3c phase with Cu content in the sample. The temperature variation of magnetization (M) plot shows sharp ferromagnetic transitions of R-3c phase at 285 K, 278 K, and 270 K (obtained from dM/dT plot) and that of Pbnm phase at 165 K, 145 K, and 145 K for x = 0, 0.05, and 0.1, respectively. Weak antiferromagnetic type feature at 25 K (x = 0), is getting pronounced with Cu content in the sample and is now seen at 32 K & 266 K (for x = 0.05) and 32K & 257 K (for x = 0.1). Fitting of Curie-Weiss law in the paramagnetic region of χ-1 vs T plot results slightly lower values of corresponding Tc's of R-3 c phase (277 K, 270 K, and 260 K), thus manifesting possibility of Griffiths like singularity. The onset temperature of Griffiths singularity occurs at 295 K (x = 0) and 281 K (x = 0.05 and 0.1), such that 295-277 K in x = 0, 281-270 K in x = 0.05, and 281-260 K in x = 0.1 sample is in Griffith's phase. Temperature dependent dielectric constant (ɛr) shows usual step-like transitions with corresponding relaxation peaks in the dielectric loss (D) part. Cu substitution in LNM makes the entire dielectric plot shifts towards lower temperature such that high temperature plateau of step transition becomes evident. The peaks in dielectric loss for all compositions are found to obey Arrhenius law with activation energies 237 meV, 207 meV, and 180 meV for x = 0, 0.05, and 0.1, respectively.

  7. Allele frequencies in the VRN-A1, VRN-B1 and VRN-D1 vernalization response and PPD-B1 and PPD-D1 photoperiod sensitivity genes, and their effects on heading in a diverse set of wheat cultivars (Triticum aestivum L.).

    PubMed

    Kiss, Tibor; Balla, Krisztina; Veisz, Ottó; Láng, László; Bedő, Zoltán; Griffiths, Simon; Isaac, Peter; Karsai, Ildikó

    2014-01-01

    Heading of cereals is determined by complex genetic and environmental factors in which genes responsible for vernalization and photoperiod sensitivity play a decisive role. Our aim was to use diagnostic molecular markers to determine the main allele types in VRN-A1, VRN-B1, VRN-D1, PPD-B1 and PPD-D1 in a worldwide wheat collection of 683 genotypes and to investigate the effect of these alleles on heading in the field. The dominant VRN-A1, VRN-B1 and VRN-D1 alleles were present at a low frequency. The PPD-D1a photoperiod-insensitive allele was carried by 57 % of the cultivars and was most frequent in Asian and European cultivars. The PPD-B1 photoperiod-insensitive allele was carried by 22 % of the genotypes from Asia, America and Europe. Nine versions of the PPD-B1-insensitive allele were identified based on gene copy number and intercopy structure. The allele compositions in PPD-D1, PPD-B1 and VRN-D1 significantly influenced heading and together explained 37.5 % of the phenotypic variance. The role of gene model increased to 39.1 % when PPD-B1 intercopy structure was taken into account instead of overall PPD-B1 type (sensitive vs. insensitive). As a single component, PPD-D1 had the most important role (28.0 % of the phenotypic variance), followed by PPD-B1 (12.3 % for PPD-B1_overall, and 15.1 % for PPD-B1_intercopy) and VRN-D1 (2.2 %). Significant gene interactions were identified between the marker alleles within PPD-B1 and between VRN-D1 and the two PPD1 genes. The earliest heading genotypes were those with the photoperiod-insensitive allele in PPD-D1 and PPD-B1, and with the spring allele for VRN-D1 and the winter alleles for VRN-A1 and VRN-B1. This combination could only be detected in genotypes from Southern Europe and Asia. Late-heading genotypes had the sensitivity alleles for both PPD1 genes, regardless of the allelic composition of the VRN1 genes. There was a 10-day difference in heading between the earliest and latest groups under field conditions.

  8. Distribution of BoLA-DRB3 allelic frequencies and identification of a new allele in the iranian cattle breed sistani (Bos indicus).

    PubMed

    Mohammadi, A; Nassiry, M R; Mosafer, J; Mohammadabadi, M R; Sulimova, G E

    2009-02-01

    The distribution of the frequencies of BoLA-DRB3 gene alleles in the Iranian cattle breed Sistani was studied by the PCR-RFLP ("hemi-nested") assay using restriction endonucleases RsaI, HaeIII and BstYI. In the examined cattle breed (65 animals) 32 alleles have been identified one of which being described for the first time (6.15% frequency). The nucleotide sequence of the polymorphic region of exon 2 of this allele has been determined and submitted in the GeneBank database under accession number DQ486519. The submitted sequence has maximum homology (92%) with the previously described sequence DRB3-mRNA from Bos indicus (AccN X79346) and differs from it by 24 nucleotide substitutions which result in 16 amino acid substitutions. The peptide (on the basis of the reconstructed amino acid sequence) has 89% identity to the sequence encoded by the BIDRBF 188 locus (Bos indicus). The results obtained permit the sequence described by us to be considered as a new allele of the BoLA-DRB3 gene (DRB3.2**X). The total frequency of the main six alleles (DRB3.2*X, *10, *11, *20, *34 and *X) occurring with a frequency of over 5% is about 60% in Iranian Sistani cattle. Fifteen alleles have <1% frequency. The highest frequency was observed for DRB3.2*8 allele (21.54%) like in other previously described breeds of Bos indicus (up to 23.07%). The Iranian breed Sistani has a high level of similarity by the spectrum of BoLA-DRB3 alleles and their frequencies to other Bos indicus breeds and significantly differs by these criteria from the Bos taurus breeds. The Iranian Sistani herd under study includes alleles associated with to resistance to leukemia (DRB3.2*ll and *23) and to different forms of mastitis (DRB3.2*2, *7, *11, *23 and *24) although their frequencies are low (from 0.77 to 5.37%). On the whole, a high level of diversity of BoLA-DRB3 gene alleles and the availability of alleles associated with resistance to different diseases makes this breed of interest for breeding practice.

  9. Identification of Amino Acid Substitutions with Compensational Effects in the Attachment Protein of Canine Distemper Virus

    PubMed Central

    Sattler, Ursula; Khosravi, Mojtaba; Avila, Mislay; Pilo, Paola; Langedijk, Johannes P.; Ader-Ebert, Nadine; Alves, Lisa A.; Plattet, Philippe

    2014-01-01

    ABSTRACT The hemagglutinin (H) gene of canine distemper virus (CDV) encodes the receptor-binding protein. This protein, together with the fusion (F) protein, is pivotal for infectivity since it contributes to the fusion of the viral envelope with the host cell membrane. Of the two receptors currently known for CDV (nectin-4 and the signaling lymphocyte activation molecule [SLAM]), SLAM is considered the most relevant for host susceptibility. To investigate how evolution might have impacted the host-CDV interaction, we examined the functional properties of a series of missense single nucleotide polymorphisms (SNPs) naturally accumulating within the H-gene sequences during the transition between two distinct but related strains. The two strains, a wild-type strain and a consensus strain, were part of a single continental outbreak in European wildlife and occurred in distinct geographical areas 2 years apart. The deduced amino acid sequence of the two H genes differed at 5 residues. A panel of mutants carrying all the combinations of the SNPs was obtained by site-directed mutagenesis. The selected mutant, wild type, and consensus H proteins were functionally evaluated according to their surface expression, SLAM binding, fusion protein interaction, and cell fusion efficiencies. The results highlight that the most detrimental functional effects are associated with specific sets of SNPs. Strikingly, an efficient compensational system driven by additional SNPs appears to come into play, virtually neutralizing the negative functional effects. This system seems to contribute to the maintenance of the tightly regulated function of the H-gene-encoded attachment protein. IMPORTANCE To investigate how evolution might have impacted the host-canine distemper virus (CDV) interaction, we examined the functional properties of naturally occurring single nucleotide polymorphisms (SNPs) in the hemagglutinin gene of two related but distinct strains of CDV. The hemagglutinin gene encodes

  10. Identification of amino acid substitutions with compensational effects in the attachment protein of canine distemper virus.

    PubMed

    Sattler, Ursula; Khosravi, Mojtaba; Avila, Mislay; Pilo, Paola; Langedijk, Johannes P; Ader-Ebert, Nadine; Alves, Lisa A; Plattet, Philippe; Origgi, Francesco C

    2014-07-01

    The hemagglutinin (H) gene of canine distemper virus (CDV) encodes the receptor-binding protein. This protein, together with the fusion (F) protein, is pivotal for infectivity since it contributes to the fusion of the viral envelope with the host cell membrane. Of the two receptors currently known for CDV (nectin-4 and the signaling lymphocyte activation molecule [SLAM]), SLAM is considered the most relevant for host susceptibility. To investigate how evolution might have impacted the host-CDV interaction, we examined the functional properties of a series of missense single nucleotide polymorphisms (SNPs) naturally accumulating within the H-gene sequences during the transition between two distinct but related strains. The two strains, a wild-type strain and a consensus strain, were part of a single continental outbreak in European wildlife and occurred in distinct geographical areas 2 years apart. The deduced amino acid sequence of the two H genes differed at 5 residues. A panel of mutants carrying all the combinations of the SNPs was obtained by site-directed mutagenesis. The selected mutant, wild type, and consensus H proteins were functionally evaluated according to their surface expression, SLAM binding, fusion protein interaction, and cell fusion efficiencies. The results highlight that the most detrimental functional effects are associated with specific sets of SNPs. Strikingly, an efficient compensational system driven by additional SNPs appears to come into play, virtually neutralizing the negative functional effects. This system seems to contribute to the maintenance of the tightly regulated function of the H-gene-encoded attachment protein. Importance: To investigate how evolution might have impacted the host-canine distemper virus (CDV) interaction, we examined the functional properties of naturally occurring single nucleotide polymorphisms (SNPs) in the hemagglutinin gene of two related but distinct strains of CDV. The hemagglutinin gene encodes the

  11. Effect of Gd and Zr co-substitution on multiferroic properties of BiFeO{sub 3}

    SciTech Connect

    Arora, Manisha Sati, Prakash Chandra Kumar, Manoj

    2014-04-24

    Single phase Bi{sub 1−x}Gd{sub x}Fe{sub 1−y}Zr{sub y}O{sub 3} (x=0.06;y=0, x= 0.10, y=0 and x=0.10,y= 0.03) nanoparticles were prepared to study the combined effect of Gd and Zr substitution on structural, magnetic and optical properties of BiFeO3. Rietveld refinement of X-ray diffraction patterns predicted that sample with x=0.06, y=0 was indexed to rhombohedral structure while samples with x=0.10, y=0 and x=0.10, y=0.03 were crystallized in multiphase (rhombohedral + orthorhombic). Magnetic properties were significantly enhanced with increasing concentration of Gd ions, however, magnetization reduced slightly with addition of 3% Zr ions in the system. Electron spin Resonance analysis indicated that breaking of spin cycloid is the main reason for enhancement of magnetization. Optical properties were investigated and direct band gap was found for all the samples.

  12. Analyzing the substitution effect on the CoMFA results within the framework of density functional theory (DFT).

    PubMed

    Morales-Bayuelo, Alejandro

    2016-07-01

    Though QSAR was originally developed in the context of physical organic chemistry, it has been applied very extensively to chemicals (drugs) which act on biological systems, in this idea one of the most important QSAR methods is the 3D QSAR model. However, due to the complexity of understanding the results it is necessary to postulate new methodologies to highlight their physical-chemical meaning. In this sense, this work postulates new insights to understand the CoMFA results using molecular quantum similarity and chemical reactivity descriptors within the framework of density functional theory. To obtain these insights a simple theoretical scheme involving quantum similarity (overlap, coulomb operators, their euclidean distances) and chemical reactivity descriptors such as chemical potential (μ), hardness (ɳ), softness (S), electrophilicity (ω), and the Fukui functions, was used to understand the substitution effect. In this sense, this methodology can be applied to analyze the biological activity and the stabilization process in the non-covalent interactions on a particular molecular set taking a reference compound.

  13. Tor1/Sch9-regulated carbon source substitution is as effective as calorie restriction in life span extension.

    PubMed

    Wei, Min; Fabrizio, Paola; Madia, Federica; Hu, Jia; Ge, Huanying; Li, Lei M; Longo, Valter D

    2009-05-01

    The effect of calorie restriction (CR) on life span extension, demonstrated in organisms ranging from yeast to mice, may involve the down-regulation of pathways, including Tor, Akt, and Ras. Here, we present data suggesting that yeast Tor1 and Sch9 (a homolog of the mammalian kinases Akt and S6K) is a central component of a network that controls a common set of genes implicated in a metabolic switch from the TCA cycle and respiration to glycolysis and glycerol biosynthesis. During chronological survival, mutants lacking SCH9 depleted extracellular ethanol and reduced stored lipids, but synthesized and released glycerol. Deletion of the glycerol biosynthesis genes GPD1, GPD2, or RHR2, among the most up-regulated in long-lived sch9Delta, tor1Delta, and ras2Delta mutants, was sufficient to reverse chronological life span extension in sch9Delta mutants, suggesting that glycerol production, in addition to the regulation of stress resistance systems, optimizes life span extension. Glycerol, unlike glucose or ethanol, did not adversely affect the life span extension induced by calorie restriction or starvation, suggesting that carbon source substitution may represent an alternative to calorie restriction as a strategy to delay aging.

  14. Effect of fluorine substitution on the interaction of lipophilic ions with the plasma membrane of mammalian cells.

    PubMed Central

    Kürschner, M; Nielsen, K; von Langen, J R; Schenk, W A; Zimmermann, U; Sukhorukov, V L

    2000-01-01

    The effects of the anionic tungsten carbonyl complex [W(CO)(5)SC(6)H(5)](-) and its fluorinated analog [W(CO)(5)SC(6)F(5)](-) on the electrical properties of the plasma membrane of mouse myeloma cells were studied by the single-cell electrorotation technique. At micromolar concentrations, both compounds gave rise to an additional antifield peak in the rotational spectra of cells, indicating that the plasma membrane displayed a strong dielectric dispersion. This means that both tungsten derivatives act as lipophilic ions that are able to introduce large amounts of mobile charges into the plasma membrane. The analysis of the rotational spectra allowed the evaluation not only of the passive electric properties of the plasma membrane and cytoplasm, but also of the ion transport parameters, such as the surface concentration, partition coefficient, and translocation rate constant of the lipophilic anions dissolved in the plasma membrane. Comparison of the membrane transport parameters for the two anions showed that the fluorine-substituted analog was more lipophilic, but its translocation across the plasma membrane was slower by at least one order of magnitude than that of the parent hydrogenated anion. PMID:10969010

  15. Isotope effects and proton hyperfine interactions in the lowest 3n pi * state of substituted benzaldehydes

    NASA Astrophysics Data System (ADS)

    Neugebauer-Crawford, S. M.; Tinti, D. S.

    1995-12-01

    The zero-field splittings, principal spin axes, kinetic parameters, and nuclear hyperfine interactions of the 3nπ* state of p-chloro- and p-methylbenzaldehyde and several of their deuterated derivatives are investigated by zero- and low-field optically detected magnetic resonance (ODMR) at 1.4 K in a p-dimethoxybenzene host. The zero-field splittings show large isotope effects. These are interpreted in terms of spin-orbit interaction with the nearby but higher lying 3ππ* state, yielding the energy gap between the two states in both benzaldehyde derivatives. The locations of the spin axes are approximately along the local symmetry axes of the carbonyl group and are insensitive to isotope. But, the spin axis most nearly normal to the plane of a host molecule deviates from the normal by an angle of 7°-13°. The kinetic parameters of the 3nπ* state also are relatively insensitive to isotope. The dominant hyperfine interactions are associated with the aldehyde hydrogen and indicate that the 3nπ* state is largely localized on the aldehyde moiety. Various properties of the 3nπ* and 3ππ* states are compared.

  16. Effect of Charge Substitutions at Residue His-142 on Voltage Gating of Connexin43 Channels

    PubMed Central

    Shibayama, Junko; Gutiérrez, Cristina; González, Daniel; Kieken, Fabien; Seki, Akiko; Requena Carrión, Jesus; Sorgen, Paul L.; Taffet, Steven M.; Barrio, Luis C.; Delmar, Mario

    2006-01-01

    Previous studies indicate that the carboxyl terminal of connexin43 (Cx43CT) is involved in fast transjunctional voltage gating. Separate studies support the notion of an intramolecular association between Cx43CT and a region of the cytoplasmic loop (amino acids 119–144; referred to as “L2”). Structural analysis of L2 shows two α-helical domains, each with a histidine residue in its sequence (H126 and H142). Here, we determined the effect of H142 replacement by lysine, alanine, and glutamate on the voltage gating of Cx43 channels. Mutation H142E led to a significant reduction in the frequency of occurrence of the residual state and a prolongation of dwell open time. Macroscopically, there was a large reduction in the fast component of voltage gating. These results resembled those observed for a mutant lacking the carboxyl terminal (CT) domain. NMR experiments showed that mutation H142E significantly decreased the Cx43CT-L2 interaction and disrupted the secondary structure of L2. Overall, our data support the hypothesis that fast voltage gating involves an intramolecular particle-receptor interaction between CT and L2. Some of the structural constrains of fast voltage gating may be shared with those involved in the chemical gating of Cx43. PMID:16963503

  17. Electron dynamics upon ionization: Control of the timescale through chemical substitution and effect of nuclear motion

    SciTech Connect

    Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.; Mendive-Tapia, David

    2015-03-07

    Photoionization can generate a non-stationary electronic state, which leads to coupled electron-nuclear dynamics in molecules. In this article, we choose benzene cation as a prototype because vertical ionization of the neutral species leads to a Jahn-Teller degeneracy between ground and first excited states of the cation. Starting with equal populations of ground and first excited states, there is no electron dynamics in this case. However, if we add methyl substituents that break symmetry but do not radically alter the electronic structure, we see charge migration: oscillations in the spin density that we can correlate with particular localized electronic structures, with a period depending on the gap between the states initially populated. We have also investigated the effect of nuclear motion on electron dynamics using a complete active space self-consistent field (CASSCF) implementation of the Ehrenfest method, most previous theoretical studies of electron dynamics having been carried out with fixed nuclei. In toluene cation for instance, simulations where the nuclei are allowed to move show significant differences in the electron dynamics after 3 fs, compared to simulations with fixed nuclei.

  18. Effect of some plant starches and carrageenan as fat substitutes in chicken patties.

    PubMed

    Das, S K; Prabhakaran, P; Tanwar, V K; Biswas, S

    2015-07-01

    This study evaluated the effect of different flours on the physicochemical, textural, and sensory properties of chicken patties. pH; cooking yield %; water holding capacity (WHC); proximate analysis (cooked); cholesterol content; and storage stability studies of control (Con) and sorghum flour (SF; 10%w/w), finger millet flour (FMF; 10%w/w), and carrageenan (Cgn; 0.5% w/w) treated chicken patties were observed in this study. Texture profile analysis (TPA) parameters like hardness, springiness, cohesiveness, gumminess, chewiness, and sensory parameters were estimated on cooked patties. Highly significant (P < 0.01) difference in fat %, total ash %, and cholesterol content; significant (P < 0.05) difference in moisture % (cooked); and no significant (P > 0.05) difference in pH, WHC, and protein % among control and treatments were noticed. Storage stability was dependent on treatments and storage periods. Significant difference (P < 0.05) was observed in different TPA parameters among the treatments, except for hardness value. Sensory scores showed no significant difference (P > 0.05) between Con and treatments.

  19. Effects of cationic substitutions on delayed rectifier current in type I vestibular hair cells.

    PubMed

    Rennie, K J; Correia, M J

    2000-01-15

    The resting potassium current (I(KI)) in gerbil dissociated type I vestibular hair cells has been characterized under various ionic conditions in whole cell voltage-clamp. When all K(+) in the patch electrode solution was replaced with Na(+), (Na(+))(in) or Cs(+), (Cs(+))(in), large inward currents were evoked in response to voltage steps between -90 and -50 mV. Activation of these currents could be described by a Hodgkin-Huxley-type kinetic scheme, the order of best fit increasing with depolarization. Above approximately -40 mV currents became outward and inactivated with a monoexponential time course. Membrane resistance was inversely correlated with external K(+) concentration. With (Na(+))(in), currents were eliminated when K(+) was removed from the external solution or following extracellular perfusion of 4-aminopyridine, indicating that currents flowed through I(KI) channels. Also, reduction of K(+) entry through manipulation of membrane potential reduced the magnitude of the outward current. Under symmetrical Cs(+), 0 K(+) conditions I(KI) is highly permeable to Cs(+). However, inward currents were reduced when small amounts of external K(+) were added. Higher concentrations of K(+) resulted in larger currents indicating an anomalous mole fraction effect in mixtures of external Cs(+) and K(+).

  20. Infrared spectroscopy of water clusters isolated in methane matrices: Effects of isotope substitution and annealing

    NASA Astrophysics Data System (ADS)

    Yamakawa, Koichiro; Ehara, Namika; Ozawa, Nozomi; Arakawa, Ichiro

    2016-07-01

    Using infrared-active solvents of CH4 and CD4 for matrix isolation, we measured infrared spectra of H2O and D2O clusters at 7 K. The solute-concentration dependence of the spectrum of H2O clusters in a CH4 matrix was investigated and was used for the peak assignment. Annealing procedures were found to promote the size growth of water clusters in methane matrices for all the combinations of (H2O, CH4), (H2O, CD4), (D2O, CH4), and (D2O, CD4). We also monitored the ν3 absorption due to methane to find the annealing-induced structural change only of solid CH4. The matrix effects on the vibrations of the clusters are discussed on the basis of "Tc plots", where their frequencies are plotted as a function of the square root of the matrix critical temperature, Tc. The obtained plots assure the validity of the assignment of the cluster peaks.

  1. Effect of Mg and Si co-substitution on microstructure and strength of tricalcium phosphate ceramics.

    PubMed

    García-Páez, Ismael H; Carrodeguas, Raúl García; De Aza, Antonio H; Baudín, Carmen; Pena, Pilar

    2014-02-01

    Magnesium and silicon co-doped tricalcium phosphate (TCP) ceramics with compositions corresponding to 0, 5 and 10wt% CaMg(SiO3)2 in the system Ca3(PO4)2-CaMg(SiO3)2 were obtained by conventional sintering of compacted mixtures of Ca3(PO4)2, MgO, SiO2 and CaCO3 powders at temperatures between 1100 and 1450°C. Microstructural analyses were performed by X-ray diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. Major phases in the obtained ceramics were β- or α+β-tricalcium phosphate containing Mg and Si in solid solution. Certain amounts of liquid were formed during sintering depending on composition and temperature. There were found significant differences in distributions of strength determined by the diametral compression of disc tests (DCDT). Failure strengths were controlled by microstructural defects associated with phase development. Mg and Si additions were found to be effective to improve densification and associated strength of TCP bioceramics due to the enhancement of sintering by the low viscosity liquids formed. The highest density and strength were obtained for the TCP ceramic containing 5wt% CaMg(SiO3)2 sintered at 1300°C. Cracking and porosity increased at higher temperatures due to grain growth and swelling.

  2. Substitution effects on superconducting and normal state properties in (Mo1-xTx)3Sb7, where T = Ru and Fe

    NASA Astrophysics Data System (ADS)

    Tran, V. H.

    2016-12-01

    The effects of Ru- and Fe-doping on the physical properties of Mo3Sb7 were studied by measuring ac-susceptibility, dc-magnetization, electrical resistivity and specific heat. It is found that single-phased (Mo{}1-xRu x )3Sb7 and (Mo{}1-xFe x )3Sb7 samples are obtained for the concentrations x ≤slant 0.1. In this concentration range, the lattice parameter shrinks with increasing dopant content. The substitution effects on the superconducting and normal state properties are completely different between two investigated systems. In the Ru-based solid solution alloys, the substitution enhances the superconducting parameters T c and H c2 and also benefits the spin-gap opening at {T}* ˜ 50 K. In contrast, in the Fe-substituted samples, there is a depression of both T c and H c2, accompanied by vanishing spin-gap and low-dimensional magnetic correlation. The substitution of the Mo atoms by Ru and Fe atoms suppresses the cubic-tetragonal distortion, but presumably favours the magnetic field to induce a magnetic order below T *.

  3. A simulation study of the potential effects of healthy food and beverage substitutions on diet quality and total energy intake in Lower Mississippi Delta adults.

    PubMed

    Thomson, Jessica L; Tussing-Humphreys, Lisa M; Onufrak, Stephen J; Zoellner, Jamie M; Connell, Carol L; Bogle, Margaret L; Yadrick, Kathy

    2011-12-01

    The majority of adult diets in the United States, particularly the South, are of poor quality, putting these individuals at increased risk for chronic diseases. In this study, simulation modeling was used to determine the effects of substituting familiar, more healthful foods and beverages for less healthy ones on diet quality and total energy intake in Lower Mississippi Delta (LMD) adults. Dietary data collected in 2000 for 1689 LMD adults who participated in the Foods of Our Delta Study were analyzed. The Healthy Eating Index-2005 (HEI-2005) was used to measure diet quality. The effects of substituting targeted foods and beverages with more healthful items on diet quality were simulated by replacing the targeted items' nutrient profile with their replacements' profile. For the single food and beverage groups, 100% replacement of grain desserts with juice-packed fruit cocktail and sugar-sweetened beverages with water resulted in the largest improvements in diet quality (4.0 and 3.8 points, respectively) and greatest decreases in total energy intake (98 and 215 kcal/d, respectively). The 100% substitution of all food and beverage groups combined resulted in a 12.0-point increase in HEI-2005 score and a decrease of 785 kcal/d in total energy intake. Community interventions designed to improve the diet of LMD adults through the use of familiar, healthy food and beverage substitutions have the potential to improve diet quality and decrease energy intake of this health disparate population.

  4. The Effect of Selective D- or Nα-Methyl Arginine Substitution on the Activity of the Proline-Rich Antimicrobial Peptide, Chex1-Arg20

    PubMed Central

    Li, Wenyi; Sun, Zhe; O'Brien-Simpson, Neil M.; Otvos, Laszlo; Reynolds, Eric C.; Hossain, Mohammed A.; Separovic, Frances; Wade, John D.

    2017-01-01

    In vivo pharmacokinetics studies have shown that the proline-rich antimicrobial peptide, A3-APO, which is a discontinuous dimer of the peptide, Chex1-Arg20, undergoes degradation to small fragments at positions Pro6-Arg7 and Val19-Arg20. With the aim of minimizing or abolishing this degradation, a series of Chex1-Arg20 analogs were prepared via Fmoc/tBu solid phase peptide synthesis with D-arginine or, in some cases, peptide backbone Nα-methylated arginine, substitution at these sites. All the peptides were tested for antibacterial activity against the Gram-negative bacterium Klebsiella pneumoniae. The resulting activity of position-7 substitution of Chex1-Arg20 analogs showed that arginine-7 is a crucial residue for maintaining activity against K. pneumoniae. However, arginine-20 substitution had a much less deleterious effect on the antibacterial activity of the peptide. Moreover, none of these peptides displayed any cytotoxicity to HEK and H-4-II-E mammalian cells. These results will aid the development of more effective and stable PrAMPs via judicious amino acid substitutions. PMID:28154813

  5. Posterolateral Arthrodesis in Lumbar Spine Surgery Using Autologous Platelet-Rich Plasma and Cancellous Bone Substitute: An Osteoinductive and Osteoconductive Effect

    PubMed Central

    Tarantino, Roberto; Donnarumma, Pasquale; Mancarella, Cristina; Rullo, Marika; Ferrazza, Giancarlo; Barrella, Gianna; Martini, Sergio; Delfini, Roberto

    2014-01-01

    Study Design Prospective cohort study. Objectives To analyze the effectiveness and practicality of using cancellous bone substitute with platelet-rich plasma (PRP) in posterolateral arthrodesis. Methods Twenty consecutive patients underwent posterolateral arthrodesis with implantation of cancellous bone substitute soaked with PRP obtained directly in the operating theater on the right hemifield and cancellous bone substitute soaked with saline solution on the right. Results Computed tomography scans at 6 and 12 months after surgery were performed in all patients. Bone density was investigated by comparative analysis of region of interest. The data were analyzed with repeated-measures variance analyses with value of density after 6 months and value of density after 12 months, using age, levels of arthrodesis, and platelet count as covariates. The data demonstrated increased bone density using PRP and heterologous cancellous block resulting in an enhanced fusion rate during the first 6 months after surgery. Conclusions PRP used with cancellous bone substitute increases the rate of fusion and bone density joining osteoinductive and osteoconductive effect. PMID:25083353

  6. Photodissociation dynamics of the Kr-HBr cluster: the effect of the rare gas atom substitution.

    PubMed

    López-López, S; García-Vela, A

    2004-01-08

    The ultraviolet photolysis dynamics of Kr-HBr(v=0) is investigated by means of wave packet calculations, focusing on the fragmentation pathway Kr-HBr+ variant Planck's over 2pi omega-->H+Kr-Br. Photolysis is simulated by starting from two different cluster initial states, namely the ground van der Waals (vdW) and an excited vdW bending state, associated with the Kr-H-Br and Kr-Br-H isomers, respectively. The results show that, for the two initial states of the cluster, the Kr-Br product yield is lower than that of Ar-Br radicals found in previous studies on Ar-HBr photolysis. Despite this decrease, the Kr-Br yield is found to be still rather high, in particular for the initial excited vdW state of Kr-HBr(v=0). In addition, the Kr-Br product state distributions exhibit a remarkably higher excitation (mainly rotational) than the corresponding Ar-Br distributions. The lower yield and higher excitation of Kr-Br as compared to Ar-Br, are attributed to a larger share of the energy available for the radical going to internal excitation in the case of the Kr-Br product. The different partition of the energy available for Kr-Br also causes significant deviations in the photolysis behavior of Kr-HBr when compared to that of Ar-HBr, in the case of the initial excited vdW state of both clusters. A common feature of the photodissociation of Kr-HBr and Ar-HBr is the manifestation of quantum interference effects in the Kr-Br and Ar-Br rotational state distributions, in the form of pronounced structures of supernumerary rotational rainbows.

  7. Proteolytic cleavage of the urokinase receptor substitutes for the agonist-induced chemotactic effect.

    PubMed Central

    Resnati, M; Guttinger, M; Valcamonica, S; Sidenius, N; Blasi, F; Fazioli, F

    1996-01-01

    Physiological concentrations of urokinase plasminogen activator (uPA) stimulated a chemotactic response in human monocytic THP-1 through binding to the urokinase receptor (uPAR). The effect did not require the protease moiety of uPA, as stimulation was achieved also with the N-terminal fragment (ATF), while the 33 kDa low molecular weight uPA was ineffective. Co-immunoprecipitation experiments showed association of uPAR with intracellular kinase(s), as demonstrated by in vitro kinase assays. Use of specific antibodies identified p56/p59hck as a kinase associated with uPAR in THP-1 cell extracts. Upon addition of ATF, p56/p59hck activity was stimulated within 2 min and returned to normal after 30 min. Since uPAR lacks an intracellular domain capable of interacting with intracellular kinase, activation of p56/p59hck must require a transmembrane adaptor. Evidence for this was strongly supported by the finding that a soluble form of uPAR (suPAR) was capable of inducing chemotaxis not only in THP-1 cells but also in cells lacking endogenous uPAR (IC50, 5 pM). However, activity of suPAR require chymotrypsin cleavage between the N-terminal domain D1 and D2 + D3. Chymotrypsin-cleaved suPAR also induced activation of p56/p59hck in THP-1 cells, with a time course comparable with ATF. Our data show that uPA-induced signal transduction takes place via uPAR, involves activation of intracellular tyrosine kinase(s) and requires an as yet undefined adaptor capable of connecting the extracellular ligand binding uPAR to intracellular transducer(s). Images PMID:8612581

  8. Effect of diet processing method and ingredient substitution on feed characteristics and survival of larval walleye, Sander vitreus

    USGS Publications Warehouse

    Barrows, F.T.; Lellis, W.A.

    2006-01-01

    Two methods were developed for the production of larval fish diets. The first method, microextrusion marumerization (MEM), has been tested in laboratory feeding trials for many years and produces particles that are palatable and water stable. The second method, particle-assisted rotational agglomeration (PARA), produced diets that have lower density than diets produced by MEM. Each method was used to produce diets in the 250- to 400- and 400- to 700-??m range and compared with a reference diet (Fry Feed Kyowa* [FFK]) for feeding larval walleye in two experiments. The effect of substituting 4% of the fish meal with freeze-dried artemia fines was also investigated. In the first experiment, 30-d survival was greater (P < 0.05) for fish fed a diet produced by PARA without Artemia (49.1.0%) than for fish fed the same diet produced by MEM (27.6%). The addition of Artemia to a diet produced by MEM did not increase survival of larval walleye. Fish fed the reference diet had 24.4% survival. In the second experiment, there was an effect of both processing method and Artemia supplementation, and an interaction of these effects, on survival. Fish fed a diet produced by PARA without Artemia supplementation had 48.4% survival, and fish fed the same diet produced by MEM had only 19.6% survival. Inclusion of 4% freeze-dried Artemia improved (P < 0.04) survival of fish fed MEM particles but not those fed PARA particles. Fish fed FFK had greater weight gain than fish fed other diets in both experiments. Data indicate that the PARA method of diet processing produces smaller, lower density particles than the MEM process and that diets produced by the PARA process support higher survival of larval walleye with low capital and operating costs. ?? Copyright by the World Aquaculture Society 2006.

  9. Design, synthesis, and antimelanogenic effects of (2-substituted phenyl-1,3-dithiolan-4-yl)methanol derivatives

    PubMed Central

    Kim, Do Hyun; Kim, Su Jeong; Ullah, Sultan; Yun, Hwi Young; Chun, Pusoon; Moon, Hyung Ryong

    2017-01-01

    The authors designed and synthesized 17 (2-substituted phenyl-1,3-dithiolan-4-yl) methanol (PDTM) derivatives to find a new chemical scaffold, showing excellent tyrosinase-inhibitory activity. Their tyrosinase-inhibitory activities were evaluated against mushroom tyrosinase at 50 μM, and five of the PDTM derivatives (PDTM3, PDTM7–PDTM9, and PDTM13) were found to inhibit mushroom tyrosinase more than kojic acid or arbutin, the positive controls. Of seventeen PDTMs, PDTM3 (half-maximal inhibitory concentration 13.94±1.76 μM), with a 2,4-dihydroxyphenyl moiety, exhibited greatest inhibitory effects (kojic acid half-maximal inhibitory concentration 18.86±2.14 μM). Interestingly, PDTM compounds with no hydroxyl group, PDTM7–PDTM9, also had stronger inhibitory activities than kojic acid. In silico studies of interactions between tyrosinase and the five PDTMs suggested their binding affinities were closely related to their tyrosinase-inhibitory activities. Cell-based experiments performed using B16F10 mouse-skin melanoma cells showed that PDTM3 effectively inhibited melanogenesis and cellular tyrosinase activity. A cell-viability study conducted using B16F10 cells indicated that the antimelanogenic effect of PDTM3 was not attributable to its cytotoxicity. Kinetic studies showed PDTM3 competitively inhibited tyrosinase, indicating binding to the tyrosinase-active site. We found that PDTM3 with a new chemical scaffold could be a promising candidate for skin-whitening agents, and that the 1,3-dithiolane ring could be used as a chemical scaffold for potent tyrosinase inhibition. PMID:28352157

  10. Effects of Ti(IV) substitution on protein adsorption behaviors of calcium hydroxyapatite particles.

    PubMed

    Kandori, Kazuhiko; Oketani, Makoto; Wakamura, Masato

    2013-01-01

    The fundamental experiments on the adsorption behaviors of proteins onto photocatalytic Ti(IV)-doped calcium hydroxyapatite (TiHap) particles with varied amounts of Ti(IV) ions doped (called as original particle) were examined comparing to those onto the calcium hydroxyapatite (CaHap) ones. The heat treated TiHaps and CaHap particles at 650°C for 1h were also examined (called as heat treated particle). The Ti/(Ca+Ti) atomic ratio (X(Ti)) of the TiHap particles was varied between 0 and 0.20. Since the surface acidity of the particles was increased by increase in X(Ti) value, the negative zeta potential (zp) of the particles was increased. All the adsorption isotherms of bovine serum albumin (BSA), myoglobin (MGB) and lysozyme (LSZ) from 1×10(-4)mol/dm(3) KCl solution were the pseudo-Langmuirian type. The saturated amounts of adsorbed LSZ (n(S)(LSZ)) values onto the original particles were increased with increase in the negative zp of the particles. However, the saturated amounts of adsorbed BSA (n(S)(BSA)) values were decreased by increase in the negative zp except at X(Ti)=0.05 where n(S)(BSA) value exhibited a maximum. In the case of MGB, the saturated amounts of adsorbed MGB (n(s)(MGB)) values were less dependent on the zp of the particles. These results were explained by changing the electrostatic forces between protein molecules and TiHap particles by doping Ti(IV) ions. On the other hand, n(S)(BSA), n(S)(LSZ) and n(s)(MGB) values onto the heat treated particles were larger than the original particles in each particle system, though no relationship to the X(Ti) value was recognized in each protein system. This result was interpreted to the formation of β-TCP crystal phase in both the CaHap and TiHap particles by the heat treatment. The Ca(2+) ions produced by dissolution from β-TCP phase may exert as binders between BSA and surfaces of the heat treated particles. The weak binder effects of Ca(2+) and PO(4)(3-) ions were observed for the adsorptions of LSZ

  11. Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan

    PubMed Central

    KOHYAMA, Moeko; TADA, Naomi; MITSUI, Hiroko; TOMIOKA, Hitomi; TSUTSUI, Toshihiko; YABUKI, Akira; RAHMAN, Mohammad Mahbubur; KUSHIDA, Kazuya; MIZUKAMI, Keijiro; YAMATO, Osamu

    2015-01-01

    Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder. PMID:26549343

  12. Strong positive selection and habitat-specific amino acid substitution patterns in MHC from an estuarine fish under intense pollution stress.

    PubMed

    Cohen, Sarah

    2002-11-01

    Population-level studies using the major histocompatibility complex (Mhc) have linked specific alleles with specific diseases, but data requirements are high and the power to detect disease association is low. A novel use of Mhc population surveys involves mapping allelic substitutions onto the inferred structural molecular model to show functional differentiation related to local selective pressures. In the estuarine fish Fundulus heteroclitus, populations experiencing strong differences in antigenic challenges show significant differences in amino acid substitution patterns that are reflected as variation in the structural location of changes between populations. Fish from a population genetically adapted to severe chemical pollution also show novel patterns of DNA substitution at a highly variable Mhc class II B locus including strong signals of positive selection at inferred antigen-binding sites and population-specific signatures of amino acid substitution. Heavily parasitized fish from an extreme PCB-contaminated (U.S. Environmental Protection Agency Superfund) site show enhanced population-specific substitutions in the a-helix portion of the inferred antigen-binding region. In contrast, fish from an unpolluted site show a significantly different pattern focused on the first strand of the B-pleated sheet. Whether Mhc population profile differences represent the direct effects of chemical toxicants or indirect parasite-mediated selection, the result is a composite habitat-specific signature of strong selection and evolution affecting the genetic repertoire of the major histocompatibility complex.

  13. The − 5 A/G single-nucleotide polymorphism in the core promoter region of MT2A and its effect on allele-specific gene expression and Cd, Zn and Cu levels in laryngeal cancer

    SciTech Connect

    Starska, Katarzyna; Krześlak, Anna; Forma, Ewa; Morawiec-Sztandera, Alina; Aleksandrowicz, Paweł; Lewy-Trenda, Iwona; and others

    2014-10-15

    Metallothioneins (MTs) are low molecular weight, cysteine-rich heavy metal-binding proteins which participate in the mechanisms of Zn homeostasis, and protect against toxic metals. MTs contain metal-thiolate cluster groups and suppress metal toxicity by binding to them. The aim of this study was to determine the − 5 A/G (rs28366003) single-nucleotide polymorphism (SNP) in the core promoter region of the MT2A gene and to investigate its effect on allele-specific gene expression and Cd, Zn and Cu content in squamous cell laryngeal cancer (SCC) and non-cancerous laryngeal mucosa (NCM) as a control. The MT2A promoter region − 5 A/G SNP was determined by restriction fragment length polymorphism using 323 SCC and 116 NCM. MT2A gene analysis was performed by quantitative real-time PCR. The frequency of A allele carriage was 94.2% and 91.8% in SCC and NCM, respectively, while G allele carriage was detected in 5.8% and 8.2% of SCC and NCM samples, respectively. As a result, a significant association was identified between the − 5 A/G SNP in the MT2A gene with mRNA expression in both groups. Metal levels were analyzed by flame atomic absorption spectrometry. The significant differences were identified between A/A and both the A/G and G/G genotypes, with regard to the concentration of the contaminating metal. The Spearman rank correlation results showed that the MT2A expression and Cd, Zn, Cu levels were negatively correlated. Results obtained in this study suggest that − 5 A/G SNP in MT2A gene may have an effect on allele-specific gene expression and accumulation of metal levels in laryngeal cancer. - Highlights: • MT2A gene expression and metal content in laryngeal cancer tissues • Association between SNP (rs28366003) and expression of MT2A • Significant associations between the SNP and Cd, Zn and Cu levels • Negative correlation between MT2A gene expression and Cd, Zn and Cu levels.

  14. Binary and ternary new water soluble copper(II) complexes of L-tyrosine and substituted 1,10-phenanthrolines: Effect of substitution on DNA interactions and cytotoxicities

    NASA Astrophysics Data System (ADS)

    İnci, Duygu; Aydın, Rahmiye; Vatan, Özgür; Yılmaz, Dilek; Gençkal, Hasene Mutlu; Zorlu, Yunus; Cavaş, Tolga

    2015-06-01

    Binary and ternary water soluble copper(II) complexes - [Cu(nphen)2(H2O)](NO3)2·H2O (1), [Cu(phen)2(H2O)](NO3)2 (2), [Cu(nphen)(L-tyr)(H2O)]NO3·2H2O (3), [Cu(phen)(tyr)(H2O)] NO3·2H2O (4) - and diquarternary salts of nphen and phen (nphen = 5-nitro-1,10-phenanthroline, phen = 1,10-phenanthroline and tyr = L-tyrosine) have been synthesized and characterized by CHN analysis, 1H NMR, 13C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by thermal denaturation measurements, absorption and emission spectroscopy. The supercoiled pUC19 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by using XTT method. The complexes 1-4 exhibit significant high cytotoxicity with low IC50 values in compared with cisplatin. The effect of the substituents of phen and coordinated amino acid in the above complexes are presented and discussed.

  15. Mutable R-Navajo Alleles of Cyclic Origin in Maize

    PubMed Central

    Brink, R. Alexander; Williams, Elizabeth

    1973-01-01

    The generation in cyclic fashion of 26 mutable R-Navajo (mRnj) alleles in maize involved transposition of a non-specific repressor of gene action, Modulator (Mp), first away from, and then back to, the R locus represented by the R-Navajo (Rnj) allele on chromosome 10. The mRnj alleles reconstituted in this way varied widely, and continuously, in mutability to Rnj—that is, in transposition of Mp away from the R locus, thus derepressing the Rnj gene. They were alike, or nearly so, however, in activating Ds chromosome breakage and in increasing the stability of variegated pericarp, another unstable compound allele comprising Mp conjoined with Prr on chromosomal 1. These latter two phenomena are based primarily on loci elsewhere in the genome. It is postulated that the 26 reconstituted mRnj alleles carry a common Mp which, however, is intercalated at a different site within each allele. Nucleotide sequence in the regions adjacent to Mp is assumed to determine the frequency with which a form of micro-nondisjunction occurs whereby Mp is released from a donor site. Transposition to a new site is interpreted in terms of a chromosome model that gives effect to nicking, or single strand breaks, occurring throughout the genome as a prerequisite to unwinding, strand separation, and replication, of the DNA double helix. PMID:17248592

  16. Effect of donor CTLA-4 alleles and haplotypes on graft-versus-host disease occurrence in Tunisian patients receiving a human leukocyte antigen-identical sibling hematopoietic stem cell transplant.

    PubMed

    Sellami, Mohamed Hichem; Bani, Meriem; Torjemane, Lamia; Kaabi, Houda; Ladeb, Saloua; Ben Othmane, Tarek; Hmida, Slama

    2011-02-01

    The CTLA-4 genetic variation, such as single nucleotide polymorphisms (SNPs) may be critical and can affect the functional activity of cells that initiate the graft-versus-host disease (GVHD) effects. The aim of this study is to examine the effect of donor CTLA-4 alleles and haplotypes for the -318C>T and the 49A>G polymorphisms on the occurrence of GVHD in Tunisians recipients of HSCs. A total of 112 patients and their 112 respective sibling donors of HSCs were enrolled in this study. All patients had either grades 0-I or grades II-IV acute GVHD, or chronic GVHD. The SNPs genotyping assay was performed using sets of sequence specific primers (SSP-PCR). The single marker association analysis showed that the 49G allele, in a genetic recessive model, may be a potential risk factor only for the chronic GVHD (p = 0.032, odds ratio [OR] = 2.58, 95% confidence interval = 1.05-6.32). The haplotypes analyses showed that the CTLA-4 -318C49G nucleotide combination is significantly associated with the incidence of chronic GVHD (p = 0.043, χ² = 3.27). Donor CTLA-4 -318C49G haplotype may be a significant risk factor for developing chronic GVHD after allo-stem cell transplantation. We suppose that donor T cells expressing this haplotype in a homozygous state have higher proliferation than those expressing other haplotypes, especially after recognition of the recipient's minor histocompatibility antigens.

  17. Resonance Raman studies of blue copper proteins: effect of temperature and isotopic substitutions. Structural and thermodynamic implications

    SciTech Connect

    Blair, D.F.; Campbell, G.W.; Schoonover, J.R.; Chan, S.I.; Gray, H.B.; Malmstrom, B.G.; Pecht, I.; Swanson, B.I.; Woodruff, W.H.; Cho, W.K.; English, A.M.

    1985-01-01

    Resonance Raman spectra of the single-copper blue proteins azurin plastocyanin and stellacyanin and the multicopper oxidases laccase ascorbate oxidase and ceruloplasmin are reported. Cryoresonance Raman observations (10-77 K) are reported for selected azurins, stellacyanin, the plastocyanins, and the laccases. Isotope studies employing /sup 63/Cu//sup 65/Cu and H/D substitution are reported for selected azurins and stellacyanin, allowing identification of modes having significant copper-ligand (Cu-L) stretch and internal ligand deformation character. Principal conclusions include the following. The only Cu-L stretching mode near 400 cm/sup -1/ is the Cu-S(Cys) stretch, and the remainder of the elementary motions near this frequency are internal ligand deformations. All the observed modes near 400 cm/sup -1/ are highly mixed, and most derive their intensity from their fractional Cu-S(Cys) stretching character. The Cu-N(His) stretching motions are best identified with the ubiquitous peak(s) near 270 cm/sup -1/, although in azurin these modes have contributions from other coordinates. Internal histidine and cysteine motions contribute to the features near 400 cm/sup -1/. This is consistent with a single resonant electronic chromophore and extremely facile vibrational dephasing or other damping processes in the electronically excited state. Temperature effects upon the spectra suggest a significant temperature-dependent structure change at the plastocyanin active site, and a more subtle one in azurin. It is shown that the Cu-S(Cys) stretching frequency is closely correlated to the electron-transfer exothermicity for several proteins, thereby indicating the reduction potential can be fine tuned by the effects of polypeptide backbone structure on the copper-sulfur bond distance and the copper-ligand field. 41 references.

  18. Effects of the charge on the structural, electronic and reactivity properties of 43 substituted N-Phenylmaleimides. A DFT study

    NASA Astrophysics Data System (ADS)

    Cortes Hernandez, Hector F.; Castro, Miguel

    2016-12-01

    The structural, electronic, and reactivity properties of 43 N-phenylmaleimide derivatives were studied by means of first principles theoretical calculations performed at the B3LYP/6-311+G(d,p) level of theory. Neutral, positively and negatively charged derivatives were studied. Different donor- and attractor-electron groups, attached at the ortho, meta and para positions, were selected, allowing to search for the effects of the charge on the geometrical, energetic and reactivity properties of the generated compounds. Firstly, the calculated ground state (GS) structures are in near agreement with the reported experimental X-Ray data and provide insight on some main features of the observed infrared spectra. Besides, the GS geometries show that the torsion angle, of the phenyl-maleimide rings, is an important parameter that impacts the properties of the species and of the polymeric chains, formed from such N-phenylmaleimides. It was found that the torsion angles depends on the nature (donor or attractor) of the selected group, on the position (ortho, meta, or para) on which the substitution was done, and on the charge (0e, +1e, -1e). For each compound, the effects of the charge on the: torsion angles, electronic (atomic populations and molecular orbitals) and energetic parameters (ionization energies and electron affinities) were studied. This information allows determining the chemical potentials, hardness, softness as well as the Fukui functions. Thus, the reactivity properties of these compounds were determined at this level of treatment. In neutral N-phenylmaleimides, the electrophylic attack mainly proceeds via the phenyl ring whereas the nucleophylic behavior is mostly defined by the imide group. These behaviors are enhanced on the cation and anion, respectively. Changes of these properties, produced by the substituent groups, are addressed.

  19. Partial substitution of pork backfat with extra-virgin olive oil in 'salami' products: effects on chemical, physical and sensorial quality.

    PubMed

    Severini, Carla; De Pilli, Teresa; Baiano, Antonietta

    2003-07-01

    The effects on chemical, physical and sensory quality of the partial substitution of pork backfat with extra-virgin olive oil were studied in 'salami' products. Four 'salami' formulations, with 15% total fat, were prepared, in which 0, 33.5, 50 and 66.5% of pork backfat was substituted with extra-virgin olive oil. The partial pork backfat substitution with extra-virgin olive oil did not substantially affect the chemical, physical and sensorial characteristics of products, with the exception of water activity and texture. With regard to both oxidation and loss of organoleptic quality, the addition of extra-virgin olive oil, rich in mono-unsaturated fatty acids, did not decrease the shelf-life. The difference between samples with and without extra-virgin olive oil was a piquant note detected in the oil-added 'salami'. The formulation with 5% olive oil, corresponding to 33.3% substitution of pork backfat with olive oil, was judged best of all formulations. The results show that it is possible to produce this type of product, of good taste, similar to the traditional one, but with healthier features.

  20. Assessment of the effects of the Japanese shift to lead-free solders and its impact on material substitution and environmental emissions by a dynamic material flow analysis.

    PubMed

    Fuse, Masaaki; Tsunemi, Kiyotaka

    2012-11-01

    Lead-free electronics has been extensively studied, whereas their adoption by society and their impact on material substitution and environmental emissions are not well understood. Through a material flow analysis (MFA), this paper explores the life cycle flows for solder-containing metals in Japan, which leads the world in the shift to lead-free solders in electronics. The results indicate that the shift has been progressing rapidly for a decade, and that substitutes for lead in solders, which include silver and copper, are still in the early life cycle stages. The results also show, however, that such substitution slows down during the late life cycle stages owing to long electronic product lifespans. This deceleration of material substitution in the solder life cycle may not only preclude a reduction in lead emissions to air but also accelerate an increase in silver emissions to air and water. As an effective measure against ongoing lead emissions, our scenario analysis suggests an aggressive recycling program for printed circuit boards that utilizes an existing recycling scheme.

  1. Effect of rare-earth (Er and Gd) substitution on the magnetic and multiferroic properties of DyFe0.5Cr0.5O3

    NASA Astrophysics Data System (ADS)

    Sharma, Mohit K.; Basu, Tathamay; Mukherjee, K.; Sampathkumaran, E. V.

    2016-10-01

    We report the results of our investigations on the influence of partial substitution of Er and Gd for Dy on the magnetic and magnetoelectric properties of DyFe0.5Cr0.5O3, which is known to be a multiferroic system. Magnetic susceptibility and heat capacity data, apart from confirming the occurrence of magnetic transitions at ~121 and 13 K in DyFe0.5Cr0.5O3, bring out that the lower transition temperature only is suppressed by rare-earth substitution. Multiferroic behavior is found to persist in Dy0.4Ln0.6Fe0.5Cr0.5O3 (Ln  =  Er and Gd). There is an evidence for magnetoelectric coupling in all these materials with qualitative differences in its behavior as the temperature is changed across these two transitions. Remnant electric polarization is observed for all the compounds. The most notable observation is that electric polarization is seen to get enhanced as a result of rare-earth substitution with respect to that in DyFe0.5Cr0.5O3. Interestingly, a similar trend is seen in the magnetocaloric effect, consistent with the existence of magnetoelectric coupling. The results thus provide evidence for the tuning of magnetoelectric coupling by rare-earth substitution in this family of oxides.

  2. Seven novel HLA alleles reflect different mechanisms involved in the evolution of HLA diversity: description of the new alleles and review of the literature.

    PubMed

    Adamek, Martina; Klages, Cornelia; Bauer, Manuela; Kudlek, Evelina; Drechsler, Alina; Leuser, Birte; Scherer, Sabine; Opelz, Gerhard; Tran, Thuong Hien

    2015-01-01

    The human leukocyte antigen (HLA) loci are among the most polymorphic genes in the human genome. The diversity of these genes is thought to be generated by different mechanisms including point mutation, gene conversion and crossing-over. During routine HLA typing, we discovered seven novel HLA alleles which were probably generated by different evolutionary mechanisms. HLA-B*41:21, HLA-DQB1*02:10 and HLA-DQA1*01:12 likely emerged from the common alleles of their groups by point mutations, all of which caused non-synonymous amino acid substitutions. In contrast, a deletion of one nucleotide leading to a frame shift with subsequent generation of a stop codon is responsible for the appearance of a null allele, HLA-A*01:123N. Whereas HLA-B*35:231 and HLA-B*53:31 were probably products of intralocus gene conversion between HLA-B alleles, HLA-C*07:294 presumably evolved by interlocus gene conversion between an HLA-C and an HLA-B allele. Our analysis of these novel alleles illustrates the different mechanisms which may have contributed to the evolution of HLA polymorphism.

  3. Rice chromosome segment substitution line selection utilizing SNP markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chromosome segment substitution lines (CSSLs) are a powerful tool for identifying naturally occurring, favorable alleles in unadapted germplasm. Six CSSL libraries in rice (Oryza sativa) are being developed from crosses between three different accessions of the rice progenitor species, O. rufipogon...

  4. A limit to the divergent allele advantage model supported by variable pathogen recognition across HLA-DRB1 allele lineages.

    PubMed

    Lau, Q; Yasukochi, Y; Satta, Y

    2015-11-01

    Genetic diversity in human leukocyte antigen (HLA) molecules is thought to have arisen from the co-evolution between host and pathogen and maintained by balancing selection. Heterozygote advantage is a common proposed scenario for maintaining high levels of diversity in HLA genes, and extending from this, the divergent allele advantage (DAA) model suggests that individuals with more divergent HLA alleles bind and recognize a wider array of antigens. While the DAA model seems biologically suitable for driving HLA diversity, there is likely an upper threshold to the amount of sequence divergence. We used peptide-binding and pathogen-recognition capacity of DRB1 alleles as a model to further explore the DAA model; within the DRB1 locus, we examined binding predictions based on two distinct phylogenetic groups (denoted group A and B) previously identified based on non-peptide-binding region (PBR) nucleotide sequences. Predictions in this study support that group A allele and group B allele lineages have contrasting binding/recognition capacity, with only the latter supporting the DAA model. Furthermore, computer simulations revealed an inconsistency in the DAA model alone with observed extent of polymorphisms, supporting that the DAA model could only work effectively in combination with other mechanisms. Overall, we support that the mechanisms driving HLA diversity are non-exclusive. By investigating the relationships among HLA alleles, and pathogens recognized, we can provide further insights into the mechanisms on how humans have adapted to infectious diseases over time.

  5. Synthesis of 2-(substituted phenyl)-3,5,5-trimethylmorpholine analogues and their effects on monoamine uptake, nicotinic acetylcholine receptor function, and behavioral effects of nicotine.

    PubMed

    Carroll, F Ivy; Muresan, Ana Z; Blough, Bruce E; Navarro, Hernán A; Mascarella, S Wayne; Eaton, J Brek; Huang, Xiaodong; Damaj, M Imad; Lukas, Ronald J

    2011-03-10

    Toward development of smoking cessation aids superior to bupropion (2), we describe synthesis of 2-(substituted phenyl)-3,5,5-trimethylmorpholine analogues 5a-5h and their effects on inhibition of dopamine, norepinephrine, and serotonin uptake, nicotinic acetylcholine receptor (nAChR) function, acute actions of nicotine, and nicotine-conditioned place preference (CPP). Several analogues encompassing aryl substitutions, N-alkylation, and alkyl extensions of the morpholine ring 3-methyl group provided analogues more potent in vitro than (S,S)-hydroxybupropion (4a) as inhibitors of dopamine or norepinephrine uptake and antagonists of nAChR function. All of the new (S,S)-5 analogues had better potency than (S,S)-4a as blockers of acute nicotine analgesia in the tail-flick test. Two analogues with highest potency at α3β4*-nAChR and among the most potent transporter inhibitors have better potency than (S,S)-4a in blocking nicotine-CPP. Collectively, these findings illuminate mechanisms of action of 2 analogues and identify deshydroxybupropion analogues 5a-5h as possibly superior candidates as aids to smoking cessation.

  6. The kinetics of ligand binding for diverse mammalian myoglobins and the effects of substitutions outside the heme cavity.

    PubMed

    Goss, D J; LaGow, J B; Parkhurst, L J

    1982-01-01

    1. We report rate constants for oxygen dissociation and for oxygen, carbon monoxide, azide, and cyanide binding to whale, horse, dog, beef and human myoglobins. 2. For azide binding, rate constants can vary by at least a factor of two for substitutions outside the heme cavity. Azide binding may be affected by a substitution at residue 66 in the E helix, a site suggested by Case & Karplus (1979) J. molec. Biol. 132, 343-368, to be on a reactive path to the heme. 3. The oxygen and CO data show that substitutions outside the heme cavity can affect rate constants by at least a factor of 1.5. 4. The oxygen equilibrium constant was correlated with the metabolite rate of the corresponding species, in accord with the Wyman (1966) J. biol. Chem. 241, 115-121, model for facilitated diffusion of oxygen.

  7. Accurate size comparison of short tandem repeat alleles amplified by PCR.

    PubMed

    Smith, R N

    1995-01-01

    A strategy is presented for classifying complex short tandem repeat (STR) alleles by size. Such alleles can differ in length by only 1 bp. The HUMACTBP2 locus was used as a model. Dye-labeled, PCR-amplified alleles were analyzed on an automated DNA sequencer with laser-induced fluorescence detection and fragment-sizing software. Between-gel allele sizes calculated against an in-lane allelic ladder or viral DNA size standard were too imprecise to distinguish a 1-bp difference. However, the size difference between a sample allele and its matching ladder allele provided a reliable criterion for size classification. The mean size difference +/- 3 SDs was 0.5 bp, and so an individual result within this interval signified a match. Statistically, 99.7% of the results should lie within +/- 3 SDs with virtually no chance of encountering the 9-SD difference from the mean necessary to misclassify an allele by 1 bp. The method was valid for sample alleles sized against the allelic ladder and for both sample and ladder alleles sized against the viral DNA standard. A correction for the effect of different dye labels on mobility was included in the calculations.

  8. Kinetic effects and mechanisms limiting substitutional solubility in the formation of supersaturated alloys by pulsed laser annealing

    SciTech Connect

    White, C.W.; Appleton, B.R.; Stritzker, B.; Zehner, D.M.; Wilson, S.R.

    1980-11-01

    Pulsed laser annealing of silicon implanted by Group (III,V) dopants leads to the formation of supersaturated alloys by nonequilibrium processes occurring in the interfacial region during liquid phase epitaxial regrowth. The distribution coefficient from the melt (k') and the maximum dopant substitutional solubility (C/sub s//sup max/) are far greater than equilibrium values and both are functions of growth velocity. Substitutional solubility is limited by lattice strain and by constitutional supercooling at the interface during regrowth. Values for C/sub s//sup max/ obtained at different velocities are compared with predictions of thermodynamic limits for solute trapping.

  9. Effect of cation substitution on bridgmanite elasticity: A key to interpret seismic anomalies in the lower mantle

    PubMed Central

    Fukui, Hiroshi; Yoneda, Akira; Nakatsuka, Akihiko; Tsujino, Noriyoshi; Kamada, Seiji; Ohtani, Eiji; Shatskiy, Anton; Hirao, Naohisa; Tsutsui, Satoshi; Uchiyama, Hiroshi; Baron, Alfred Q. R.

    2016-01-01

    Seismological observations show that, in some regions of the lower mantle, an increase in bulk sound velocity, interestingly, occurs in the same volume where there is a decrease in shear velocity. We show that this anti-correlated behavior occurs on cation substitution in bridgmanite by making single crystal elasticity measurements of MgSiO3 and (Mg,Fe,Al)(Si,Al)O3 using inelastic x-ray scattering in the ambient conditions. Cation substitution of ferrous iron and aluminum may explain large low shear velocity provinces in the lower mantle. PMID:27642083

  10. Effects of different fixation and freeze substitution methods on the ultrastructural preservation of ZYMV-infected Cucurbita pepo (L.) leaves.

    PubMed

    Zechmann, Bernd; Müller, Maria; Zellnig, Günther

    2005-08-01

    Different fixation protocols [chemical fixation, plunge and high pressure freezing (HPF)] were used to study the effects of Zucchini yellow mosaic virus (ZYMV) disease on the ultrastructure of adult leaves of Styrian oil pumpkin plants (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) with the transmission electron microscope. Additionally, different media were tested for freeze substitution (FS) to evaluate differences in the ultrastructural preservation of cryofixed plant leaf cells. FS was either performed in (i) 2% osmium tetroxide in anhydrous acetone containing 0.2% uranyl acetate, (ii) 0.01% safranin in anhydrous acetone, (iii) 0.5% glutaraldehyde in anhydrous acetone or (iv) anhydrous acetone. No ultrastructural differences were found in well-preserved cells of plunge and high pressure frozen samples. Cryofixed cells showed a finer granulated cytosol and smoother membranes, than what was found in chemically fixed samples. HPF led in comparison to plunge frozen plant material to an excellent preservation of vascular bundle cells. The use of FS-media such as anhydrous acetone, 0.01% safranin and 0.5% glutaraldehyde led to low membrane contrast and did not preserve the inner fine structures of mitochondria. Additionally, the use of 0.5% glutaraldehyde caused the cytosol to be fuzzy and partly loosened. ZYMV-induced ultrastructural alterations like cylindrical inclusions and dilated ER-cisternae did not differ between chemically fixed and cryofixed cells and were found within the cytosol of infected leaf cells and within sieve tube elements. The results demonstrate specific structural differences depending on the FS-medium used, which has to be considered for investigations of selected cell structures.

  11. Reentrant spin-glass behavior and bipolar exchange-bias effect in "Sn" substituted cobalt-orthotitanate

    NASA Astrophysics Data System (ADS)

    Nayak, S.; Joshi, D. C.; Krautz, M.; Waske, A.; Eckert, J.; Thota, S.

    2016-01-01

    We report the co-existence of longitudinal ferrimagnetic behavior with Néel temperature TN ˜ 46.1 K and reentrant transverse spin-glass state at 44.05 K in Tin (Sn) doped cobalt-orthotitanate (Co2TiO4). The ferrimagnetic ordering is resulting from different magnetic moments of Co2+ on the A-sites (3.87 μB) and B-sites (5.069 μB). The magnetic compensation temperature (TCOMP) shifts from 31.74 K to 27.1 K when 40 at. % of "Sn4+" substitutes "Ti4+" at B-sites where the bulk-magnetization of two-sublattices balance each other. For T > TN, the dc-magnetic susceptibility (χdc = M/Hdc) fits well with the Néel's expression for the two-sublattice model with antiferromagnetic molecular field constants NBB ˜ 15.44, NAB ˜ 32.01, and NAA ˜ 20.88. The frequency dependence of ac-magnetic susceptibility χac data follows the Vogel-Fulcher law, and the power-law of critical slowing-down with "zν" = 6.01 suggests the existence of spin-clusters (where "z" and "ν" being dynamic critical-exponent and correlation length of critical-exponent, respectively). This system exhibits unusual hysteresis loops with large bipolar exchange-bias effect (HEB ˜ 13.6 kOe at 7 K) after zero-field cooling process from an un-magnetized state, and a dramatic collapse of remanence (MR) and coercive field (HC) across TCOMP. The possible origins of such anomalous characteristics were discussed.

  12. Structural and catalytic effects of an invariant purine substitution in the hammerhead ribozyme: implications for the mechanism of acid-base catalysis.

    PubMed

    Schultz, Eric P; Vasquez, Ernesto E; Scott, William G

    2014-09-01

    The hammerhead ribozyme catalyzes RNA cleavage via acid-base catalysis. Whether it does so by general acid-base catalysis, in which the RNA itself donates and abstracts protons in the transition state, as is typically assumed, or by specific acid-base catalysis, in which the RNA plays a structural role and proton transfer is mediated by active-site water molecules, is unknown. Previous biochemical and crystallographic experiments implicate an invariant purine in the active site, G12, as the general base. However, G12 may play a structural role consistent with specific base catalysis. To better understand the role of G12 in the mechanism of hammerhead catalysis, a 2.2 Å resolution crystal structure of a hammerhead ribozyme from Schistosoma mansoni with a purine substituted for G12 in the active site of the ribozyme was obtained. Comparison of this structure (PDB entry 3zd4), in which A12 is substituted for G, with three previously determined structures that now serve as important experimental controls, allows the identification of structural perturbations that are owing to the purine substitution itself. Kinetic measurements for G12 purine-substituted schistosomal hammerheads confirm a previously observed dependence of rate on the pK(a) of the substituted purine; in both cases inosine, which is similar to G in pK(a) and hydrogen-bonding properties, is unexpectedly inactive. Structural comparisons indicate that this may primarily be owing to the lack of the exocyclic 2-amino group in the G12A and G12I substitutions and its structural effect upon both the nucleotide base and phosphate of A9. The latter involves the perturbation of a previously identified and well characterized metal ion-binding site known to be catalytically important in both minimal and full-length hammerhead ribozyme sequences. The results permit it to be suggested that G12 plays an important role in stabilizing the active-site structur