204,825 research outputs found
Investigations of Streptomyces coelicolor A3(2) siderophore binding proteins
No full textSiderophores are small, high-affinity ferric iron chelators released by many microorganisms and some plants to solubilize iron. They are of great interest due to their clinical use to treat iron overload in humans, and also in relation to the development of novel antibiotics that target the biosynthetic and uptake pathways for iron in pathogens. Pathogens such as Bacillus anthracis excrete more than one type of siderophore. This is linked to increased pathogenicity. The Gram-positive soil bacterium Streptomyces coelicolor A3(2) excretes three siderophores: desferrioxamine B, desferrioxamine E and coelichelin. These displace iron from insoluble ferric hydroxides, and the resulting ferric complexes are transported into the cell via siderophore-binding proteins (lipoprotein receptors) associated with ATP-binding cassette (ABC) transporters. Previous studies showed that some of the genes in the biosynthetic clusters of the desferrioxamines (des) and coelichelin (cch) were required for efficient uptake of ferrioxamine E and ferri-coelichelin respectively and a third ABC transporter gene cluster (cdt), not associated with siderophore biosynthesis genes, was implicated in the import of ferrioxamine B. In this study, the lipoprotein receptors encoded within the des, cch and cdt clusters - DesE, CchF and CdtB – were recombinantly overproduced in E. coli and purified by immobilized metal affinity chromatography. Also, ferri-coelichelin was purified from cultures of S. coelicolor. The binding of the ferric complexes of the three cognate siderophores, as well as the xenosiderophores ferrichrome and ferrialbomycin, to the lipoprotein receptors was monitored by intrinsic fluorescence quenching. Dissociation constants of receptor-siderophore complexes were found to be in the nanomolar range, and a revised model of cognate siderophore transport in S. coelicolor was proposed. In collaboration with researchers at St. Andrews University, an X-ray crystal structure was solved for apo-DesE and DesE bound to ferrioxamine B, which demonstrated the similarity of DesE to other bacterial siderophore-binding proteins and the negligible conformational change on substrate binding. Ferrioxamine B also exhibited an unusual configuration not observed before in X-ray crystals of this ferri-siderophore. Also, a forcefield was constructed to model the structure and distortions ferric-tris-hydroxamate complexes, which could be used in the future to investigate the molecular basis of the tight and specific binding of ferri-siderophores to siderophore-binding proteins
WDN EPANET - PRAKASH
No full textThese data are related to "Design and optimization of real time pipe flow Water Distribution Network to minimize the cost of implementation" Data includes
1. Theatrical analysis values
2. EPANET analysis values and outputs
3. comparison values
4. water distribution network drawings
5. Pipe cost comparison
Protohyale covelongensis Raut, Prakash & Arjunan
No full text<p> <b> 256. <i>Protohyale covelongensis</i> Raut, Prakash & Arjunan in Raut, Prakash, Arjunan & Kumar, 2022</b> <b>Type locality:</b> Covelong, Chennai Coast, Tamil Nadu, India.</p> <p> <b>Distribution. World:</b> India (Raut <i>et al.</i> 2022).</p> <p> <b>India: Eastern India Ecoregion:</b> (Raut <i>et al.</i> 2022).</p>Published as part of <i>Thacker, Dimple, Patel, Krupal, Myers, Alan, Guerra-García, José M., Zeidler, Wolfgang & Trivedi, Jigneshkumar, 2023, Annotated Checklist of Marine Amphipods (Crustacea: Amphipoda) of India, pp. 1-90 in Zootaxa 5340 (1)</i> on page 75, DOI: 10.11646/zootaxa.5340.1.1, <a href="http://zenodo.org/record/8324090">http://zenodo.org/record/8324090</a>
Empire-building and thinking in the Public Works Department of British India
No full textPeter Scriverhttp://www.routledge.com/books/Colonial-Modernities-isbn978041539909
Buoyancy considerations in a fluidized bed of ground particles:
No full textThe research conducted for this thesis determines and quantifies the forces acting on a large submerged object in a gas-solid fluidized bed of Geldart A ground particles at the onset of bubbling. In particular, the additional load from the previously reported de-fluidized region of particles found above submerged objects in fluidized beds is quantified. A force model was developed and comparisons between this and the experimental data yielded properties of the de-fluidized region, such as the shape and height of the hood, and the angle to which it rises. Drag is measured by comparing forces on objects of different geometries subject to the same conditions. Buoyancy was measured by summing the pressure force acting to push the submerged object out of the bed and the counteracting pressure force of the bed over the submerged object pushing it deeper into the bed. The de-fluidized region is found to have a significant impact on the buoyancy of the object by creating an additional weight force above the object thus increasing the pressure in this region. Explanations for the hood shape and size are made through phenomenological results obtained through visual observations. Particle transport through voidage collapses at the surface, i.e. “bubbling”, create a secondary particle circulation within the bed adding particles to the top of the hood. The size of the bubbles appears to determine the extent of the hood.M.S.Includes bibliographical references (p. 78-79)by Prakash R. Ra
Modeling and heuristic worst-case performance analysis of the two-level network design problem
No full text"Revised: November 1992"--2nd prelim. p.Includes bibliographical references.Supported by a grant from the AT&T Research Fund. Supported by a Faculty Grant from the Katz Graduate School of Business, University of Pittsburgh.Anantaram Balakrishnan, Thomas L. Magnanti and Prakash Mirchandani
Political economy of conflict and peace: governmentality of participation and strategic veto in Bihar and Jharkhand, India
No full textThis chapter analyzes dynamics of conflict in Bihar and Jharkand, and explores patterns which shape governance policies, especially in terms of political economy. The author claims that all actors involved in the conflict have the power to exercise a strategic veto, however they cannot structure the outcomes. Naxals on the one side, and state actors on the other, can exercise a strategic veto on each other’s operational activities and at the same time they limit each other in terms of policies pursued. However, the state can exercise more power in this case, as it sets terms of engagement. Prakash highlights the importance of the distribution of developmental benefits and claims that they play a central role in protracting the Naxal conflict. In order to break out of this perpetuation of the conflict, local institutions have to be strengthened, especially in terms of their ability to prioritise issues that they deem important, argues Prakash.</p
Metamorphic P-T conditions and CO(2) influx history of medium-grade metapelites from Karakorum, Trans-Himalaya, India
No full textAbstract not availableHimanshu K. Sachan, M. Santosh, Divya Prakash, Aditya Kharya, P. Chandra Singh, Santosh K. Ra
Sediment and heavy mineral chemistry studies along the course of the river Cauvery, South India.
No full textPrakash Narasimha, Pradeep. P.
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