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A retrospective analysis of windthrows in southern taiga forests (Kostroma oblast and neighboring lands) is performed. The main traits of massive windthrows are calculated. The dominant spatial forms of windthrows are identified. The average annual rates of the forest-cover damage from clearcuts, forest fires, and windblows are compared. The topographical effect on the spatial distribution of fragments of massive windthrows is analyzed. 相似文献
104.
Tobacco use and environmental air pollution are the established etiological factors in head and neck cancer (HNC) progression. Nevertheless, not all the inhabitants with high usage of tobacco from the same polluted locality are suffering with HNC and this is due to the existence of factors like inter-individual genetic polymorphisms, life time exposure to tobacco and the rate of xenobiotic metabolism enzyme (XME) activity. The present study investigates the polymorphic genotypes of the most important XME, glutathione-S-transferase Mu 1 (GST M1) and Theta 1 (GST T1) as the risk modulator to HNC among tobacco-habituated inhabitants of Saurashtra in Gujarat, a region in western India. A population based case–control study was done in 252 HNC patients and 504 healthy controls. Blood samples were collected from the subjects and investigated for polymorphic genotypes of GST M1 and GST T1. Estimation of the odds of risks was done by logistic regressions. Among the subjects with high usage of tobacco, M1 not null-T1 null genotypes presence was found as risk reducing factor to HNC with 0.334 folds (95 % CI; 0.170–0.659). The presence of M1 null-T1 not null genotypes was found with susceptibility to HNC among the subjects with no habit of tobacco chewing, adjusted odds ratio (AOR) 3.170 (1.128–8.913) and no habit of smoking, AOR of 2.544 (1.094–5.963). The present study reveals the finding of significantly increased risk to HNC by interactions of GST M1 null-GST T1 not null polymorphic genotypes among the subjects with nil or less tobacco usage shed some light for the insights of biomarker application in early detection of HNC. 相似文献
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N. G. Averina E. L. Nedved’ R. A. Shcherbakov I. V. Vershilovskaya E. B. Yaronskaya 《Russian Journal of Plant Physiology》2014,61(5):679-687
Growing of winter rape (Brassica napus L.) plants for 7–8 days in the presence of a sulfonylurea herbicide Magnum (methsulfuron methyl; 200 and 500 mg/L) exerted an organ-specific influence on the seedlings: suppressed hypocotyl and root growth and increased the accumulation of fresh weight of cotyledonary leaves. Exogenous 5-aminolevulinic acid (ALA; 0.1, 1.0, and 10 mg/L) partially negated the adverse effect of Magnum on the length and fresh weight of roots and hypocotyls and stimulated the development of cotyledons. The herbicide suppressed the activity of ascorbate peroxidase (APX). The addition of ALA to the 200 mg/L herbicide solution caused a steady activation of APX as compared with the effect of herbicide alone. In plants grown on Magnum solutions, the activity of glutathione reductase (GR) rose. Positive effect of exogenous ALA was only observed when 500 mg/L herbicide was used (Magnum-500 type of treatment). In plants grown on the Magnum solution, the content of reduced and oxidized forms of glutathione rose. In contrasty, exogenous ALA reduced the total content of glutathione but in this case the ratio between its reduced and oxidized forms rose. In the presence of the herbicide, the content of anthocyans considerably decreased and upon the addition of exogenous ALA their levels rose. In rape plants treated with Magnum, the ability to generate superoxide anion radical was essentially the same as in control plants; however, the content of hydrogen peroxide (H2O2) therein rose. The addition of ALA to the herbicide reduced the ability to generate superoxide anion radical and the level of H2O2. The activity of acetolactate synthase remained on the control level when 200 mg/L Magnum was used, decreased in the plants of Magnum-500 treatment, and rose upon the addition of exogenous ALA to this type of treatment. It was concluded that ALA had a positive effect on the development of winter rape resistance to Magnum via stimulation of growth processes, activation of APX and GR, predominant elevation of the content of reduced glutathione and anthocyans, and partial recovery of acetolactate synthase activity, which on the whole caused a decrease in the H2O2 level and in the ability of plants to generate superoxide anion radical. 相似文献
107.
Susan Morrison Grace John-Stewart John J. Egessa Sezi Mubezi Sylvia Kusemererwa Dennis K. Bii Nulu Bulya Francis Mugume James D. Campbell Jonathan Wangisi Elizabeth A. Bukusi Connie Celum Jared M. Baeten Partners PrEP Study Team 《PloS one》2015,10(10)
During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting. 相似文献
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109.
E. Ciani P. Crepaldi L. Nicoloso E. Lasagna F. M. Sarti B. Moioli F. Napolitano A. Carta G. Usai M. D'Andrea D. Marletta R. Ciampolini V. Riggio M. Occidente D. Matassino D. Kompan P. Modesto N. Macciotta P. Ajmone‐Marsan F. Pilla 《Animal genetics》2014,45(2):256-266
Italy counts several sheep breeds, arisen over centuries as a consequence of ancient and recent genetic and demographic events. To finely reconstruct genetic structure and relationships between Italian sheep, 496 subjects from 19 breeds were typed at 50K single nucleotide polymorphism loci. A subset of foreign breeds from the Sheep HapMap dataset was also included in the analyses. Genetic distances (as visualized either in a network or in a multidimensional scaling analysis of identical by state distances) closely reflected geographic proximity between breeds, with a clear north–south gradient, likely because of high levels of past gene flow and admixture all along the peninsula. Sardinian breeds diverged more from other breeds, a probable consequence of the combined effect of ancient sporadic introgression of feral mouflon and long‐lasting genetic isolation from continental sheep populations. The study allowed the detection of previously undocumented episodes of recent introgression (Delle Langhe into the endangered Altamurana breed) as well as signatures of known, or claimed, historical introgression (Merino into Sopravissana and Gentile di Puglia; Bergamasca into Fabrianese, Appenninica and, to a lesser extent, Leccese). Arguments that would question, from a genomic point of view, the current breed classification of Bergamasca and Biellese into two separate breeds are presented. Finally, a role for traditional transhumance practices in shaping the genetic makeup of Alpine sheep breeds is proposed. The study represents the first exhaustive analysis of Italian sheep diversity in an European context, and it bridges the gap in the previous HapMap panel between Western Mediterranean and Swiss breeds. 相似文献
110.
Kung-Jong Lui Duane Steffey Jamie K. Pugh 《Biometrical journal. Biometrische Zeitschrift》1993,35(6):677-688
Calculating the required sample size for a desired power at a given type I error level, we often assume that we know the exact time of all subject responses whenever they occur during our study period. It is very common, however, in practice that we only monitor subjects periodically and, therefore, we know only whether responses occur or not during an interval. This paper includes a quantitative discussion of the effect resulting from data grouping or interval censoring on the required sample size when we have two treatment groups. Furthermore, with the goal of exploring the optimum in the number of subjects, the number of examinations per subject for test responses, and the total length of a study time period, this paper also provides a general guideline about how to determine these to minimize the total cost of a study for a desired power at a given α-level. A specified linear cost function that incorporates the costs of obtaining subjects, periodic examinations for test responses of subjects, and the total length of a study period, is assumed, primarily for illustrative purpose. 相似文献