53 research outputs found
Forest carbon stocks and fluxes in physiographic zones of India
<p>Abstract</p> <p>Background</p> <p>Reducing carbon Emissions from Deforestation and Degradation (REDD+) is of central importance to combat climate change. Foremost among the challenges is quantifying nation's carbon emissions from deforestation and degradation, which requires information on forest carbon storage. Here we estimated carbon storage in India's forest biomass for the years 2003, 2005 and 2007 and the net flux caused by deforestation and degradation, between two assessment periods i.e., Assessment Period first (ASP I), 2003-2005 and Assessment Period second (ASP II), 2005-2007.</p> <p>Results</p> <p>The total estimated carbon stock in India's forest biomass varied from 3325 to 3161 Mt during the years 2003 to 2007 respectively. There was a net flux of 372 Mt of CO<sub>2 </sub>in ASP I and 288 Mt of CO<sub>2 </sub>in ASP II, with an annual emission of 186 and 114 Mt of CO<sub>2 </sub>respectively. The carbon stock in India's forest biomass decreased continuously from 2003 onwards, despite slight increase in forest cover. The rate of carbon loss from the forest biomass in ASP II has dropped by 38.27% compared to ASP I.</p> <p>Conclusion</p> <p>With the Copenhagen Accord, India along with other BASIC countries China, Brazil and South Africa is voluntarily going to cut emissions. India will voluntary reduce the emission intensity of its GDP by 20-25% by 2020 in comparison to 2005 level, activities like REDD+ can provide a relatively cost-effective way of offsetting emissions, either by increasing the removals of greenhouse gases from the atmosphere by afforestation programmes, managing forests, or by reducing emissions through deforestation and degradation.</p
The Regulation of Sulfur Metabolism in Mycobacterium tuberculosis
Mycobacterium tuberculosis (Mtb) has evolved into a highly successful human pathogen. It deftly subverts the bactericidal mechanisms of alveolar macrophages, ultimately inducing granuloma formation and establishing long-term residence in the host. These hallmarks of Mtb infection are facilitated by the metabolic adaptation of the pathogen to its surrounding environment and the biosynthesis of molecules that mediate its interactions with host immune cells. The sulfate assimilation pathway of Mtb produces a number of sulfur-containing metabolites with important contributions to pathogenesis and survival. This pathway is regulated by diverse environmental cues and regulatory proteins that mediate sulfur transactions in the cell. Here, we discuss the transcriptional and biochemical mechanisms of sulfur metabolism regulation in Mtb and potential small molecule regulators of the sulfate assimilation pathway that are collectively poised to aid this intracellular pathogen in its expert manipulation of the host. From this global analysis, we have identified a subset of sulfur-metabolizing enzymes that are sensitive to multiple regulatory cues and may be strong candidates for therapeutic intervention
Linearized esculentin-2EM shows pH dependent antibacterial activity with an alkaline optimum
Here the hypothesis that linearized esculentin 2EM (E2EM-lin) from Glandirana emeljanovi possesses pH dependent activity is investigated. The peptide showed weak activity against Gram-negative bacteria (MLCs ≥ 75.0 μM) but potent efficacy towards Gram-positive bacteria (MLCs ≤ 6.25 μM). E2EM-lin adopted an α-helical structure in the presence of bacterial membranes that increased as pH was increased from 6 to 8 (↑ 15.5 to 26.9 %), while similar increases in pH enhanced the ability of the peptide to penetrate (↑ 2.3 to 5.1 mN m-1) and lyse (↑ 15.1 to 32.5%) these membranes. Theoretical analysis predicted that this membranolytic mechanism involved a tilted segment, that increased along the α-helical long axis of E2EM-lin (1-23) in the N → C direction, with - increasing overall from circa - 0.8 to - 0.3. In combination, these data showed that E2EM-lin killed bacteria via novel mechanisms that were enhanced by alkaline conditions and involved the formation of tilted and membranolytic, α-helical structure. The preference of E2EM-lin for Gram-positive bacteria over Gram-negative organisms was primarily driven by the superior ability of phosphatidylglycerol to induce α-helical structure in the peptide as compared to phosphatidylethanolamine. These data were used to generate a novel pore-forming model for the membranolytic activity of E2EM-lin, which would appear to be the first, major reported instance of pH dependent AMPs with alkaline optima using tilted structure to drive a pore-forming process. It is proposed that E2EM-lin has the potential for development to serve purposes ranging from therapeutic usage, such as chronic wound disinfection, to food preservation by killing food spoilage organisms
Rapid identification of rust resistance genes through cultivar-specific de novo chromosome assemblies
“Map-based cloning” is a frequently used approach to isolate rust resistance genes. A critical step during map-based cloning is the transition from genetic information, i.e., a genetic map, to physical sequence information. Bacterial artificial chromosome clones are often used to establish sequence information spanning a genetic interval. However, a major limitation of BAC clones consists in their small insert size of 100–200 kb. Targeted chromosome-based cloning via long-range assembly (TACCA) is a method that can replace BAC library screening. This approach involves chromosome flow-sorting and the establishment of a long-range de novo assembly. This chapter provides an overview of TACCA as well as a detailed description of sequence analyses, molecular marker development, and candidate gene identification
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