751 research outputs found

    Nuclear structure study around Z=28

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    Yrast levels of Ni, Cu and Zn isotopes for 40N5040 \leq N \leq50 have been described by state-of-the-art shell model calculations with three recently available interactions using 56^{56}Ni as a core in the f5/2pg9/2f_{5/2}pg_{9/2} model space. The results are unsatisfactory viz. large E(2+)E(2^+) for very neutron rich nuclei, small B(E2) values in comparison to experimental values. These results indicate an importance of inclusion of πf7/2\pi f_{7/2} and νd5/2\nu d_{5/2} orbitals in the model space to reproduce collectivity in this region.Comment: 12 pages, 14 figure

    Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts

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    Attempts to use coarse-grained molecular theories to calculate corrections to the random-phase approximation (RPA) for correlations in polymer mixtures have been plagued by an unwanted sensitivity to the value of an arbitrary cutoff length, {\it i.e.}, by an ultraviolet (UV) divergence. We analyze the UV divergence of the inverse structure factor S1(k)S^{-1}(k) predicted by a `one-loop' approximation similar to that used in several previous studies. We consider both miscible homopolymer blends and disordered diblock copolymer melts. We show, in both cases, that all UV divergent contributions can be absorbed into a renormalization of the values of the phenomenological parameters of a generalized self-consistent field theory (SCFT). This observation allows the construction of a UV convergent theory of corrections to SCFT phenomenology. The UV-divergent one-loop contribution to S1(k)S^{-1}(k) are shown to be the sum of: (i) a kk-independent contribution that arises from a renormalization of the effective χ\chi parameter, (ii) a kk-dependent contribution that arises from a renormalization of monomer statistical segment lengths, (iii) a contribution proportional to k2k^{2} that arises from a square-gradient contribution to the one-loop fluctuation free energy, and (iv) a kk-dependent contribution that is inversely proportional to the degree of polymerization, which arises from local perturbations in fluid structure near chain ends and near junctions between blocks in block copolymers.Comment: 35 pages, 2 figure

    26-Desmethyl-2-methylene-22-ene-19-nor-1 alpha,25-dihydroxyvitamin D-3 compounds selectively active on intestine

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    Six new analogs of 2-methylene-19-nor-1 alpha,25-dihydroxyvitamin D-3, 6-7 and 8a,b-9a,b, have been synthesized. All compounds are characterized by a trans double bond located in the side chain between C-22 and C-23. While compounds 6 and 7 possess C-26 and C-27 methyls, compounds 8a,b and 9a,b lack one of these groups. A Lythgoe-based synthesis, employing the Wittig-Horner reaction was used for these preparations. Two different types of Delta E-22-25-hydroxy Grundmann's ketone, having either only one stereogenic center located at position C-20 (20 and 21), or two stereogenic centers located at 20- and 25-positions (24a,b-25a,b) were obtained by a multi-step procedure from commercial vitamin D-2. The introduction of a double bond at C-22 appeared to lower biological activity in vitro and in vivo. Further removal of a 26-methyl in these analogs had little effect on receptor binding, HL-60 differentiation and CYP24A expression but markedly diminished or eliminated in vivo activity on bone calcium mobilization while retaining activity on intestinal calcium transport. (C) 2014 Elsevier Inc. All rights reserved

    Venture Capital and Business Angels and the Creation of Innovative Firms in Poland

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    The article also points out that conditions fostering further development of the described types of entrepreneurship and innovation financing and a dynamic environment generating innovative capacity should be created.W artykule zasygnalizowano również potrzebę kreowania uwarunkowań sprzyjających rozwojowi opisanych form finansowania przedsiębiorczości, innowacyjności i dynamicznego otoczenia generującego zdolności innowacyjne

    2-methylene-(20S,25S)-19,27-dinor-(22E)-vitamin D analogs

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    This invention discloses 2-methylene-(20S,25S)-19,27-dinor-(22E)-vitamin D analogs, and specifically 2-methylene-(20S,25S)-19,27-dinor-(22E)-1.alpha.,25-dihydroxyvitamin D.sub.3, and pharmaceutical uses therefor. This compound exhibits pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. This compound also has little, if any, calcemic activity and therefore may be used to treat autoimmune disorders or inflammatory diseases in humans as well as renal osteodystrophy. This compound may also be used for the treatment or prevention of obesity

    Confocal laser scanning microscopy as a valuable tool in Diptera larval morphology studies

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    Larval morphology of flies is traditionally studied using light microscopy, yet in the case of fine structures compound light microscopy is limited due to problems of resolution, illumination and depth of field, not allowing for precise recognition of sclerites’ edges and interactions. Using larval instars of cyclorrhaphan Diptera, we show the usefulness of confocal laser scanning microscopy (CLSM) for studying the morphological characters of immature stages by taking advantage of the autofluorescent properties of cephaloskeleton structures. We compare data obtained from killed but unprepared larvae with those from larvae prepared by clearing according to two commonly used methods, either with potassium hydroxide or with Hoyer’s medium. We also evaluated the CLSM application for examining already slide-mounted larvae stored in museum collections and those freshly prepared. Our results indicate that CLSM and 3D reconstruction are excellent for visualizing small, compound structures of cylrorrhaphan larvae cephaloskeleton, if appropriate clearing techniques, i.e. the application of KOH, are used. Maximum intensity projection of confocal data sets obtained from material freshly prepared and that stored in museum collection does not differ. Because of this and the fact that KOH is commonly used as a clearing method to examine the cephaloskeleton of Diptera larvae, it is possible, and highly recommended, to use slides already prepared with this method for re-examination by CLSM. We conclude that CLSM application can be an invaluable source of data for studies of larval morphology of Cyclorrhapha by way of taxonomic diagnoses, character identification and improvement in characters homologization.This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited

    Alternative pest control approaches NPV for pod borer control and its uptake in Nepal

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    Pod borer is the most serious pest of chickpea in Nepal and its control based upon chemical insecticides alone has met major problems of resistance. There is a clear need for alternative pod borer control techniques. One of the most promising alternative controls i nucleopolyhedrovirus or NPV This is effective, safe and has bee adopted in a number of countries as part of the national pod bore IPM strategy. The chickpea IPM project has conducted evaluation of NPV in Nepal and results show it to be as effective or better than existing chemical control. However, if promotion of NPV in Nepal for pod borer control were to be adopted, a policy for the supply of NPV would need to be developed. Importation is feasible but local production would probably be cheaper. Several models of local production exist including farmer production, village production, state or extension service production and commercial private sector production and these models need to be evaluated for adoption in Nepal. A national system of regulation for NPV would also need to be developed

    On-Farm IPM Of Chickpea In Nepal Proceedings of the International Workshop on Planning and Implementation of On-farm Chickpea IPM in Nepal 6-7 September 2000

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    Chickpea is a traditional crop, and is an important component in the daily diet of the Nepalese. It is one of the major grain legume crops grown as a sole or mixed crop in the rice- and maize-based cropping systems in Nepal. Area under chickpea has shown a decreasing trend for the last two decades, as a result of increasing incidence of diseases (botrytis gray mold) and insects (pod borer). Additionally abiotic constraints have also been identified, causing low and unstable yields at the national level. Consequences of decreased chickpea cultivation in Nepal include reduced opportunities for ameliorative effects of legumes on cropping system and sustainability, and decreased local accessibility of chickpea as a nutritious dietary component, particularly for poor sections of the community. Scientists from Nepal Agricultural Research Council (NARC), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Natural Resources Institute (NRI), non-governmental organizations, and farmers (women and men) participated in the meeting. The present status of various components of on-farm integrated pest management (IPM) in Nepal were discussed and accounts of current research on IPM in different institutions were presented. Good progress has been made and prospects of continued collaborative research and development on IPM are encouraging. Site specific work plans and role of partners with the funding for the period of three years (2000-03) from the Crop Protection Programme (CPP) of the Department for International Development (DFID), UK were finalized. High priority was given to participatory on-farm validation and scale-up of the available components of IPM of botrytis gray mold and pod borer and their integration with other improved agronomical practices for sustainable chickpea production in Nepal
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