772 resultados para Grain orientation
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Most research on sexual orientation and alcohol use in the United States has found higher rates of alcohol use and abuse among gay men and lesbians. Studies from other countries have found smaller or no differences between sexual minority and heterosexual women and men. The present study used general population survey data from 14 countries to examine high-volume and risky single-occasion drinking by sexual orientation. Data from 248 gay men and lesbians and 3720 heterosexuals were analyzed in a case-control design. In several countries partnered or recently partnered gay men and lesbians had no greater risk of heavy drinking or engaging in heavy drinking than heterosexual controls. Only lesbians in North America showed higher risk for both indicators. Future general population health research should include larger samples of gays and lesbians and use more comprehensive measures of sexual orientation for investigating the prevalence of health risk factors.
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There is a wide range of evidence to suggest that permeability can be constrained through of induced polarization measurements. For clean sands and sandstones, current mechanistic models of induced polarization predict a relationship between the low-frequency time constant inferred from induced polarization measurements and the grain diameter. A number of observations do, however, disagree with this and indicate that the observed relaxation behavior is rather governed by the so-called dynamic pore radius L. To test this hypothesis, we have developed a set of new scaling relationships, which allow the relaxation time to be computed from the pore size and the permeability to be computed from both the Cole-Cole time constant and the formation factor. Moreover, these new scaling relationships can be also used to predict the dependence of the Cole-Cole time constant as a function of the water saturation under unsaturated conditions. Comparative tests of the proposed new relationships with regard to various published experimental results for saturated clean sands and sandstones as well as for partially saturated clean sandstones, do indeed confirm that the dynamic pore radius L is a much more reliable indicator of the observed relaxation behavior than grain-size-based models.
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Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin. Via meta-analysis of data from 14 cohorts comprising ∼ 48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant. Greater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: -0.009 mmol/l glucose [-0.013 to -0.005], P < 0.0001 and -0.011 pmol/l [ln] insulin [-0.015 to -0.007], P = 0.0003). No interactions met our multiple testing-adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele. Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.
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Selostus: Aluskasveja voi käyttää toistuvasti viljan viljelyssä
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The interest in reducing maize row spacing in the short growing season regions of Brazil is increasing due to potential advantages such as higher radiation use efficiency. This experiment was conducted to evaluate the effect of row spacing reduction on grain yield of different maize cultivars planted at different dates. The trial was conducted in Lages, in the State of Santa Catarina, Brazil, during 1996/97 and 1997/98 growing seasons, in a split-split plot design. Early (October 1st) and normal (November 15) planting dates were tested in the main plot; two morphologically contrasting cultivars (an early single-cross and a late double-cross hybrids) were evaluated in the split plots and three row widths (100, 75 and 50 cm) were studied in the split-split plots. The reduction of row spacing from 100 to 50 cm increased linearly maize grain yield. The yield edge provided by narrow rows was higher when maize was sown earlier in the season. Differences in hybrid cycle and plant architecture did not alter maize response to the reduction of row spacing.
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L'objectif de ce travail est l'analyse des composantes psychologiques et relationnelles en jeu dans le counseling d'orientation, plus particulièrement du rôle de l'alliance de travail et des caractéristiques individuelles des clients en tant que facteurs d'explication du succès de l'intervention. L'étude porte sur un échantillon de 101 personnes, âgées de 15 à 41 ans et impliquées dans une démarche d'accompagnement en orientation scolaire et professionnelle. La satisfaction vis-à-vis de l'intervention, les niveaux d'indécision vocationnelle (CDDQ) au début et à l'issue de l'intervention, l'alliance de travail (WAI), la personnalité (NEO-FFI-R), ainsi que les caractéristiques sociodémographiques ont été évalués à l'aide d'instruments validés. L'impact des consultations est observé à travers une réduction importante du niveau d'indécision, t (87) = 9.27 , p < .001, d = .77. Les résultats montrent une forte association entre l'alliance et la satisfaction, r = .54, p < .001, ainsi qu'un lien négatif entre l'alliance et le niveau d'indécision à l'issue de l'intervention, r = -.31, p < .01. En outre, certaines dimensions de la personnalité, comme le névrosisme ou le caractère consciencieux, contribuent à l'explication des effets observés. Cependant, la personnalité et les variables sociodémographiques ne constituent pas des variables modératrices de la relation entre l'alliance de travail et la satisfaction ou l'indécision à l'issue de l'intervention. Cette étude témoigne que les effets du counseling d'orientation dépendent aussi bien de facteurs cognitifs que de paramètres affectifs et relationnels.
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Selostus: Paljasjyväisen kauran hellävarainen sadonkorjuu
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Photosynthetic activity of cereals has traditionally been studied using leaves, thus neglecting the role of other organs such as ears. Here, we studied the effects of water status and genotypes on the photosynthetic activity of the flag leaf blade and the ear of durum wheat. The various parameters related to the photosynthetic activity were analysed in relation to the total above-ground plant biomass and grain yield at maturity. Four local varieties plus two cultivars adapted to the semiarid areas of South Morocco were grown in pots in a greenhouse. Five different water treatments were maintained from the beginning of stem elongation to maturity, when shoot biomass and grain yield were recorded. The net photosynthesis (A), stomatal conductance (gs) and transpiration (T) of the ear and the flag leaf were measured at anthesis. In both organs these factors decreased significantly with water deficit, whereas the A/T and A/gs ratios increased. The genotype effect was also significant for all traits studied. Whole-organ photosynthesis was much higher in the ear than in the flag leaf in well-watered conditions. As water stress developed, photosynthesis decreased less in the ear than in the flag leaf. Whole-ear photosynthesis correlated better than flag leaf photosynthesis with biomass and yield. Nevertheless, the relationships of the whole flag leaf with biomass and yield improved as the water stress became more severe, suggesting a progressive shift of yield from sink to source limitation. For all water regimes the ratios A/gs and A/T of the ear also showed a higher (negative) correlation with both biomass and yield than those of the flag leaf. The results indicate that the ear has a greater photosynthetic role than the flag leaf in determining grain yield, not only in drought but also in the absence of stress.
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Understanding the influence of pore space characteristics on the hydraulic conductivity and spectral induced polarization (SIP) response is critical for establishing relationships between the electrical and hydrological properties of surficial unconsolidated sedimentary deposits, which host the bulk of the world's readily accessible groundwater resources. Here, we present the results of laboratory SIP measurements on industrial-grade, saturated quartz samples with granulometric characteristics ranging from fine sand to fine gravel, which can be regarded as proxies for widespread alluvial deposits. We altered the pore space characteristics by changing (i) the grain size spectra, (ii) the degree of compaction, and (iii) the level of sorting. We then examined how these changes affect the SIP response, the hydraulic conductivity, and the specific surface area of the considered samples. In general, the results indicate a clear connection between the SIP response and the granulometric as well as pore space characteristics. In particular, we observe a systematic correlation between the hydraulic conductivity and the relaxation time of the Cole-Cole model describing the observed SIP effect for the entire range of considered grain sizes. The results do, however, also indicate that the detailed nature of these relations depends strongly on variations in the pore space characteristics, such as, for example, the degree of compaction. The results of this study underline the complexity of the origin of the SIP signal as well as the difficulty to relate it to a single structural factor of a studied sample, and hence raise some fundamental questions with regard to the practical use of SIP measurements as site- and/or sample-independent predictors of the hydraulic conductivity.
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The objective of this work was to evaluate the effects of selection for high protein on seed physiological quality and grain yield of soybean. Four populations of BC1F4 and four of F4, each from a cross between a commercial variety and a line bearing high protein seeds, were used. The high protein content selection has a tendency to affect negatively the seed physiological quality. Estimates of correlation coefficients between protein content and grain yield were mostly negative but varied among populations. It is possible to obtain lines with high protein content, keeping the grain yield and the seed physiological quality of their respective recurrent progenitors.
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Since red alleles (R) of the genes that control grain colour are important for the improvement of preharvest sprouting resistance in wheat and there are three independently inherited loci, on chromosomes 3A, 3B and 3D of hexaploid wheat, it is possible to vary the dosage of dominant alleles in a breeding program. The objective of this work was to evaluate the dosage effect of R genes on preharvest sprouting, in a single seed descent population, named TRL, derived from the cross between Timgalen, white-grained wheat, and RL 4137, red-grained wheat. The study was carried out using sprouting data in ripe ears obtained under artificial conditions in a rainfall simulator over three years. According to the results there is a significant effect on preharvest sprouting provided by colour and a weaker effect of increasing R dosage. However, the significant residual genotypic variation between red lines and all lines (reds and whites) at 0.1% level showed that preharvest sprouting was also controlled by other genes. There are no significant correlations between sprouting and date of ripeness or between ripeness, R dosage and colour intensity.
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The objective of this work was to investigate heterosis and its components in 16 white grain maize populations presenting high quality protein. These populations were divided according to grain type in order to establish different heterosis groups. The crosses were carried out according to a partial diallel cross design among flint and dent populations. Seven agronomic traits were evaluated in three environments while four leaf diseases and incidence of corn stunt were evaluated in one. Least square procedure was applied to the normal equation X'Xbeta = X'Y, to estimate the model effects and their respective sum of squares. Among the heterosis components, in diallel analysis, significance for average heterosis in grain yield, number of days to female flowering and to all evaluated diseases was detected. Specific heterosis was significant for days to female flowering and resistance to Puccinia polysora. Results concerned to grain yield trait indicate that populations with superior performance in dent group, no matter what flint population group is used in crosses, tend to generate superior intervarietal hybrids. In decreasing order of preference, the dent type populations CMS 476, ZQP/B 103 and ZQP/B 101 and the flint type CMS 461, CMS 460, ZQP/B 104 and ZQP/B 102 are recommended to form composites.
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A model has been developed for evaluating grain size distributions in primary crystallizations where the grain growth is diffusion controlled. The body of the model is grounded in a recently presented mean-field integration of the nucleation and growth kinetic equations, modified conveniently in order to take into account a radius-dependent growth rate, as occurs in diffusion-controlled growth. The classical diffusion theory is considered, and a modification of this is proposed to take into account interference of the diffusion profiles between neighbor grains. The potentiality of the mean-field model to give detailed information on the grain size distribution and transformed volume fraction for transformations driven by nucleation and either interface- or diffusion-controlled growth processes is demonstrated. The model is evaluated for the primary crystallization of an amorphous alloy, giving an excellent agreement with experimental data. Grain size distributions are computed, and their properties are discussed.
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AIM: Sexual orientation plays an important part in building identity during adolescence. The aim of this study was to describe patterns of sexual orientation, including sexual attraction, fantasies, affiliations and behaviour. METHODS: The study was based on the analysis of data from computerized self-administered questionnaires of a Swiss national survey on the sexual life of 16 to 20-year-old adolescents (n = 2,075 girls and 2,208 boys.). RESULTS: Overall, 95.0% of girls and 96.2% of boys described themselves as predominantly heterosexual; 1.4% of girls and 1.7% of boys as predominantly homosexual or bisexual; and 2.8% of teenagers (girls: 3.6%; boys: 2.1%) were "unsure" of their sexual orientation. The reported prevalence of homosexual attraction (girls: 2.0%; boys: 2.9%) exceeded homosexual fantasies (girls: 0.4%; boys: 0.5%) and affiliations (girls: 0.3%; boys: 0.5%). Among the 4205 respondents, 31 girls (1.5% of girls) and 56 boys (2.5% of boys) reported sexual behaviour (experience or penetrative intercourse) with a person of the same sex. Among 1.5% of girls and 2.5% of boys who reported sexual behaviour with a person of the same sex, 65% of boys and 80% of girls nevertheless considered themselves as heterosexual. CONCLUSION: For a comprehensive understanding of sexual orientation in adolescence a differentiated look at dimensions of sexual orientation is indispensable. This applies to clinical settings, public health and research.