2,021 research outputs found
Genetic diversity and relationship assessment among mulberry (Morus spp) genotypes by simple sequence repeat (SSR) marker profile
Mulberry (Morus L.) is essential for sericulture industry as the primary source of food for silkworm Bombyx mori L. In India, long tradition of practising sericulture includes the use of a large number of indigenous cultivars. Since knowledge on genetic divergence of these cultivars/varieties is imperative for conservation and gainful utilization, simple sequence repeat (SSR) profiling was employed to assess genetic relatedness among 17 mulberry genotypes maintained in the Germplasm Bank of Temperate Sericulture Institute, SKUAST Kashmir, Mirgund. Six SSR primers were utilised which generates 17 alleles among the genotypes. The polymorphism information content (PIC) value varied from 0.260 (MulSTR3) to 0.623 (MulSTR4), with an average of 0.438 per locus. The highest similarity value of 0.92 was observed between Lemoncina and Kanva-2, as compared to the lowest similarity coefficient of 0.15 was between SKM-48 and Chinese white. Clustering of the genotypes was done with unweight pair group method using arithmetic average (UPGMA) which generates five clusters. Cluster-2 contained maximum (six) genotypes.Keywords: Clustering, genetic relatedness, mulberry, SSRAfrican Journal of Biotechnology Vol. 12(21), pp. 3181-318
On RR couplings on D-branes at order
Recently, it has been found that there are couplings of the RR field strength
and the B-field strength on the world volume of D-branes at
order . These couplings which have both world-volume and
transverse indices, are invariant under the linear T-duality transformations.
Consistency with the nonlinear T-duality indicates that the RR field strength
in these couplings should be replaced by where . This replacement, however, reproduces some
non-gauge invariant terms. On the other hand, the nonlinear terms are invariant
under the linear T-duality transformations at the level of two B-fields. This
allows one to remove some of the nonlinear terms in . We fix
this by comparing the nonlinear couplings with the S-matrix element of one RR
and two NSNS vertex operators. Our results indicate that in the expansion of
one should keep only the B-field gauge invariant terms, e.g.
where both indices of B-field lie along the brane.
Moreover, in this case one should replace with to have the
-field gauge invariance.Comment: 23 pages, Latex file, 1 figure; v2:typos corrected, to appear in JHE
Accelerated vaccination against HBV infection is an important strategy for the control of HBV infection in prisons
Genetic diversity analysis in the Hypericum perforatum populations in the Kashmir valley by using inter-simple sequence repeats (ISSR) markers
Assessment of genetic variability among the Hypericum perforatum populations is critical to the development of effective conservation strategies in the Kashmir valley. To obtain accurate estimates of genetic diversity among and within populations of H. perforatum, inter-simple sequence repeats (ISSR) markers were used. The study was aimed to check, whether ISSR fingerprinting may be a useful tool for studying genetic variations among H. perforatum populations in the Kashmir valley (India). A total of 15 ISSR primers were tested with the 20 genotypes of H. perforatum. The ten informative primers were selected and used to evaluate the degree of polymorphism and genetic relationships within and among all the H. perforatum populations. ISSR of 20 genotypes analysis yielded 98 fragments that could be scored, of which 71 were polymorphic, with an average of 7.1 polymorphic fragments per primer. Number of amplified fragments varied in size from 150 to 1650 bp. Percentage of polymorphism ranged from 60% to a maximum of 100%. Resolving power ranged from a minimum of 7.7 to a maximum of 14.3. Shannon indexes ranges from 0.166 to 0.389 with an average of 0.198 and Nei’s genetic diversity (h) ranges from 6.98 to 9.8. Estimated value of gene flow (Nm = 0.579) indicated that there was limited gene flow among the populations. The genetic diversity (Ht) within the population of 0.245 was clearly higher than that of among population genetic diversity (Hs= 0.115), indicating an out-crossing predominance in the studied populations. Analysis of molecular variance by ISSR markers indicated that over half of the total variation in the studied populations (58%) could be accounted for by differences among the 8 divisions, with a further 42% being accounted for by the variation among populations within a division.The dendrogram grouping the populations by unweighted pair-group method with arithmeticaverages (UPGMA) method revealed eight main clusters. In conclusion, combined analysis of ISSR markers and hypericin content is an optimal approach for further progress and breeding programs.Keywords: Hypericum perforatum (St. John's Wort), inter-simple sequence repeats (ISSR) markers, unweighted pair-group method with arithmetic averages (UPGMA), Nei’s genetic diversityAfrican Journal of Biotechnology, Vol. 13(1), pp. 18-31, 1 January, 201
A multivariate morphometric investigation to delineate stock structure of gangetic whiting, Sillaginopsis panijus (Teleostei: Sillaginidae)
This study was conducted to delineate the stock structure of Sillaginopsis paniijus based on morphometric characters of the species. A total of 194 specimens were collected from the Meghna, Tentulia and Baleswar rivers located in the southern coastal zone of Bangladesh. Data were subjected to univariate ANOVA, multivariate ANOVA, discriminate function analysis (DFA), and principal component analysis. Mean variations of ten morphometric characters; HD, HBD, LBD, PsOL, ED, SnL, SPrDL, HAF, LSDB and LPB showed significant differences (p < 0.05) among 27 morphometric traits that were selected for the study. In DFA, the overall assignments of individuals into their correctly classified original groups were 71.1 and 70.6 % for male and female, respectively. A scatter plot of the first two discriminant functions was used to visually depict the discrimination among the populations. The results showed different stocks of S. panijus in the rivers of Baleswar, Tentulia and Meghna in southwest coast of Bangladesh
Gendered Representations of Male and Female Social Actors in Iranian Educational Materials
This research investigates the representations of gendered social actors within the subversionary discourse of equal educational opportunities for males and females in Iranian English as a Foreign Language (EFL) books. Using critical discourse analysis (CDA) as the theoretical framework, the authors blend van Leeuwen’s (Texts and practices: Readings in critical discourse analysis, Routledge, London, 2003) ‘Social Actor Network Model’ and Sunderland’s (Gendered discourses, Palgrave Macmillan, Hampshire, 2004) ‘Gendered Discourses Model’ in order to examine the depictions of male and female social actors within this gendered discourse. The gendered discourse of equal opportunities was buttressed by such representations within a tight perspective in proportion to gender ideologies prevailing in Iran. Resorting to CDA, we can claim that resistance against such gendered discourse in Iranian EFL textbooks militates against such gender norms. These representations of male and female social actors in school books are indicative of an all-encompassing education, reinforcing that the discourse of equal opportunities is yet to be realized in the education system of Iran
Air Travel and Venous Thromboembolism: A Systematic Review
CONTEXT: Despite multiple attempts to document and quantify the danger of venous thromboembolism (VTE) following prolonged travel, there is still uncertainty about the magnitude of risk and what can be done to lower it. OBJECTIVES: To review the methodologic strength of the literature, estimate the risk of travel-related VTE, evaluate the efficacy of preventive treatments, and develop evidence-based recommendations for practice. DATA SOURCES: Studies identified from MEDLINE from 1966 through December 2005, supplemented by a review of the Cochrane Central Registry of Controlled Trials, the Database of Abstracts of Reviews of Effects, and relevant bibliographies. STUDY SELECTION: We included all clinical studies that either reported primary data concerning travel as a risk factor for VTE or tested preventive measures for travel-related VTE. DATA EXTRACTION AND ANALYSIS: Two reviewers reviewed each study independently to assess inclusion criteria, classify research design, and rate methodologic features. The effect of methodologic differences, VTE risk, and travel duration on VTE rate was evaluated using a logistic regression model. DATA SYNTHESIS: Twenty-four published reports, totaling 25 studies, met inclusion criteria (6 case-control studies, 10 cohort studies, and 9 randomized controlled trials). Method of screening for VTE [screening ultrasound compared to usual clinical care, odds ratio (OR) 390], outcome measure [all VTE compared to pulmonary embolism (PE) only, OR 21], duration of travel (<6 hours compared to 6–8 hours, OR 0.011), and clinical risk (“higher” risk travelers compared to “lower,” OR 3.6) were significantly related to VTE rate. Clinical VTE after prolonged travel is rare [27 PE per million flights diagnosed through usual clinical care, 0.05% symptomatic deep venous thrombosis (DVT) diagnosed through screening ultrasounds], but asymptomatic thrombi of uncertain clinical significance are more common. Graduated compression stockings prevented travel-related VTE (P < 0.05 in 4 of 6 studies), aspirin did not, and low-molecular-weight heparin (LMWH) showed a trend toward efficacy in one study. CONCLUSIONS: All travelers, regardless of VTE risk, should avoid dehydration and frequently exercise leg muscles. Travelers on a flight of less than 6 hours and those with no known risk factors for VTE, regardless of the duration of the flight, do not need DVT prophylaxis. Travelers with 1 or more risk factors for VTE should consider graduated compression stockings and/or LMWH for flights longer than 6 hours
Central Pb+Pb Collisions at 158 A GeV/c Studied by Pion-Pion Interferometry
Two-particle correlations have been measured for identified negative pions
from central 158 AGeV Pb+Pb collisions and fitted radii of about 7 fm in all
dimensions have been obtained. A multi-dimensional study of the radii as a
function of kT is presented, including a full correction for the resolution
effects of the apparatus. The cross term Rout-long of the standard fit in the
Longitudinally CoMoving System (LCMS) and the vl parameter of the generalised
Yano-Koonin fit are compatible with 0, suggesting that the source undergoes a
boost invariant expansion. The shapes of the correlation functions in Qinv and
Qspace have been analyzed in detail. They are not Gaussian but better
represented by exponentials. As a consequence, fitting Gaussians to these
correlation functions may produce different radii depending on the acceptance
of the experimental setup used for the measurement.Comment: 13 pages including 10 figure
Search for Disoriented Chiral Condensates in 158 AGeV Pb+Pb Collisions
The restoration of chiral symmetry and its subsequent breaking through a
phase transition has been predicted to create regions of Disoriented Chiral
Condensates (DCC). This phenomenon has been predicted to cause anomalous
fluctuations in the relative production of charged and neutral pions in
high-energy hadronic and nuclear collisions. The WA98 experiment has been used
to measure charged and photon multiplicities in the central region of 158 AGeV
Pb+Pb collisions at the CERN SPS. In a sample of 212646 events, no clear DCC
signal can be distinguished. Using a simple DCC model, we have set a 90% C.L.
upper limit on the maximum DCC production allowed by the data.Comment: 20 Pages, LaTeX, uses elsart.cls, 8 eps figures included, submitted
to Physics Letters
Metabolic determinants of cancer cell sensitivity to glucose limitation and biguanides
As the concentrations of highly consumed nutrients, particularly glucose, are generally lower in tumours than in normal tissues1,2, cancer cells must adapt their metabolism to the tumour microenvironment. A better understanding of these adaptations might reveal cancer cell liabilities that can be exploited for therapeutic benefit. Here, we developed a continuous flow culture apparatus (Nutrostat) for maintaining proliferating cells in low nutrient media for long periods of time and used it to undertake competitive proliferation assays on a pooled collection of barcoded cancer cell lines cultured in low glucose conditions. Sensitivity to low glucose varies amongst cell lines, and an RNAi screen pinpointed mitochondrial oxidative phosphorylation (OXPHOS) as the major pathway required for optimal proliferation in low glucose. We found that cell lines most sensitive to low glucose are defective in the upregulation of OXPHOS normally caused by glucose limitation as a result of either mtDNA mutations in Complex I genes or impaired glucose utilization. These defects predict sensitivity to biguanides, anti-diabetic drugs that inhibit OXPHOS3,4, when cancer cells are grown in low glucose or as tumour xenografts. Remarkably, the biguanide sensitivity of cancer cells with mtDNA mutations was reversed by ectopic expression of yeast NDI1, a ubiquinone oxidoreductase that allows bypass of Complex I function5. Thus, we conclude that mtDNA mutations and impaired glucose utilization are potential biomarkers for identifying tumours with increased sensitivity to OXPHOS inhibitors
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