1,679 research outputs found

    Study of genetic diversity of wild Caspian trout Salmo trutta caspius in the Sardabrud and Astara Rivers, using D-Loop region sequencing

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    In this study the genetic diversity of wild Caspian trout (Salmo trutta caspius) in the Sardabroud and Astara Rivers was evaluated using D-Loop region sequencing. For this purpose, 35 specimens of adult Caspian brown trout were collected from these rivers in the Mazandarn and Gilan Provinces in fall and winter 2011. Approximately 3-5 g of soft and fresh fin tissue was isolated and fixed in ethanol 96% and then transferred to the Caspian Sea Ecology Research Center Genetics Laboratory in Sari, Iran. Genomic DNA from the samples was extracted using Ammonium Acetate Method. The quality and quantity of the extracted DNA were assessed by spectrophotometer and agarose gel (1%) electrophoresis. Polymerase Chain Reaction (PCR) was performed on the target DNA using a primers sequence D-Loop region of mtDNA molecule. Then the product was purified and DNA sequencing was carried out using chain termination method. The D-Loop region of Caspian trout contained 654 bp. Data were analyzed using Bio-Edit, DnaSP, Arlequin and Mega software. 20 and 15 haplotypes was observed in Sardabrud and Astara River. The DNA sequence of one of them was recorded in Gene Bank with numbers KC991027 and KF015727. 223 and 240 polymorphic loci were detected in Sardabrud and Astara River that all of them were out of Hardy-Weinberg equilibrium (p<0.05). Average nucleotide and haplotype diversity were 0.127±0.067, 1.000±0.005 in Sardabrud River and 0.118±0.063 and 1.000±0.005 in Astara River

    Spatial patterns and links between microbial community composition and function in cyanobacterial mats

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    We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky

    Dissolution of calcium carbonate: observations and model results in the North Atlantic

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    International audienceWe investigate the significance of in situ dissolution of calcium carbonate above its saturation horizons. The study relies on observations from the open subpolar North Atlantic [sNA] and on a 3-D biogeochemical model. The sNA is particularly well suited for observation-based detections of in situ, i.e. shallow depth CaCO3 dissolution [SDCCD] as it is a region of high CaCO3 production, deep CaCO3 saturation horizons, and precisely-defined pre-formed alkalinity. Based on the analysis of a comprehensive alkalinity data set we find that SDCCD does not appear to be a significant process in the open sNA. The results from the model support the observational findings and do not indicate a significant need of SDCCD to explain observed patterns of alkalinity in the North Atlantic. Instead our investigation points to the importance of mixing processes for the redistribution of alkalinity from dissolution of CaCO3 from below its saturation horizons. However, mixing has recently been neglected for a number of studies that called for SDCCD in the sNA and on global scale

    A lattice determination of Sigma - Lambda mixing

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    Isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects and lead to small mass splittings. Between the Sigma and Lambda this mass splitting is much larger, this being mostly due to their different wavefunctions. However when isospin is broken, there is a mixing between between these states. We describe the formalism necessary to determine the QCD mixing matrix and hence find the mixing angle and mass splitting between the Sigma and Lambda particles due to QCD effects.Comment: 40 pages, 5 figures, published versio

    Dissolution of calcium carbonate: observations and model results in the subpolar North Atlantic

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    We investigate the significance of in situ dissolution of calcium carbonate above its saturation horizons using observations from the open subpolar North Atlantic [sNA] and to a lesser extent a 3-D biogeochemical model. The sNA is particularly well suited for observation-based detections of in situ, i.e. shallow-depth CaCO3 dissolution [SDCCD] as it is a region of high CaCO3 production, deep CaCO3 saturation horizons, and precisely-defined pre-formed alkalinity. Based on the analysis of a comprehensive alkalinity data set we find that SDCCD does not appear to be a significant process in the open sNA. The results from the model support the observational findings by indicating that there is not a significant need of SDCCD to explain observed patterns of alkalinity in the North Atlantic. Instead our investigation points to the importance of mixing processes for the redistribution of alkalinity from dissolution of CaCO3 from below its saturation horizons. However, mixing has recently been neglected for a number of studies that called for SDCCD in the sNA and on global scale

    What unleashes innovations in the Legumes and Cereals farming Systems in the drylands: A gendered perspective

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    Agricultural and natural resource management innovations have often been introduced, promoted and adopted among local communities / farmers. However, how the innovation process is perceived by men and women, the relationships involved, the distribution of benefits and the differing capacities of women and men to take advantage of the new opportunities in agriculture are not always carefully thought-out. This study examined both community and individual men and women's experiences with agricultural innovations and practices and how these interactions support or hinder the achievement of agricultural innovations across various contexts. By providing robust empirical evidence on the relationship between gender norms, agency and agricultural innovation, the study revealed that sociocultural structures and household dynamics chiefly shapes how individuals negotiate for space, freedom, resources and the capacities needed to innovate

    Blood Levels of S-100 Calcium-Binding Protein B, High-Sensitivity C-Reactive Protein, and Interleukin-6 for Changes in Depressive Symptom Severity after Coronary Artery Bypass Grafting: Prospective Cohort Nested within a Randomized, Controlled Trial

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    Background: Cross-sectional and retrospective studies have associated major depressive disorder with glial activation and injury as well as blood–brain barrier disruption, but these associations have not been assessed prospectively. Here, we aimed to determine the relationship between changes in depressive symptom severity and in blood levels of S-100 calcium- binding protein B (S-100B), high-sensitivity C-reactive protein, and interleukin-6 following an inflammatory challenge. Methods: Fifty unselected participants were recruited from a randomized, controlled trial comparing coronary artery bypass grafting procedures performed with versus without cardiopulmonary bypass for the risk of neurocognitive decline. Depressive symptom severity was measured at baseline, discharge, and six-month follow-up using the Beck Depression Inventory II (BDI-II). The primary outcome of the present biomarker study was acute change in depressive symptom severity, defined as the intra-subject difference between baseline and discharge BDI-II scores. Blood biomarker levels were determined at baseline and 2 days postoperative. Results: Changes in S-100B levels correlated positively with acute changes in depressive symptom severity (Spearman r, 0.62; P=0.0004) and accounted for about one-fourth of their observed variance (R2, 0.23; P=0.0105). This association remained statistically significant after adjusting for baseline S-100B levels, age, weight, body-mass index, or b-blocker use, but not baseline BDI-II scores (P = 0.064). There was no statistically significant association between the primary outcome and baseline S-100B levels, baseline high-sensitivity C-reactive protein or interleukin-6 levels, or changes in high-sensitivity C- reactive protein or interleukin-6 levels. Among most participants, levels of all three biomarkers were normal at baseline and markedly elevated at 2 days postoperative. Conclusions: Acute changes in depressive symptom severity were specifically associated with incremental changes in S- 100B blood levels, largely independent of covariates associated with either. These findings support the hypothesis that glial activation and injury and blood–brain barrier disruption can be mechanistically linked to acute exacerbation of depressive symptoms in some individuals
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