33,214 research outputs found

    Institutional development work in the World Bank : a review of 84 bank projects

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    Institutional weakness is a critical constraint to economic development. The goal of this paper is to review the design of recent Bank projects to assess the quality of their institutional development (ID) components and the factors that may affect that quality. A major focus is Bank staffing and organization, and the following issues are addressed: (a) the quality of institutional analysis and ID components in the design of current Bank project; (b) the ID work that is being done in Bank projects; (c) qualifications needed for effective ID work; (d) the impact the Bank's organizational structure has on ID work; and (e) suggestions that can be made to broaden and strengthen the ID work in Bank projects.Banks&Banking Reform,Health Monitoring&Evaluation,Health Economics&Finance,Municipal Financial Management,Rural Portfolio Improvement

    New string vacua from twistor spaces

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    We find a new family of AdS_4 vacua in IIA string theory. The internal space is topologically either the complex projective space CP^3 or the "flag manifold" SU(3)/(U(1)xU(1)), but the metric is in general neither Einstein nor Kaehler. All known moduli are stabilized by fluxes, without using quantum effects or orientifold planes. The analysis is completely ten--dimensional and does not rely on assumptions about Kaluza--Klein reduction.Comment: 19 pages. v3: published version, further minor correction

    Fracture mechanics approach to design analysis of notches, steps and internal cut-outs in planar components

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    A new approach to the assessment and optimization of geometric stress-concentrating features is proposed on the basis of the correspondence between sharp crack or corner stressfield intensity factors and conventional elastic stress concentration factors (SCFs) for radiused transitions. This approach complements the application of finite element analysis (FEA) and the use of standard SCF data from the literature. The method makes it possible to develop closed-form solutions for SCFs in cases where corresponding solutions for the sharp crack geometries exist. This is helpful in the context of design optimization. The analytical basis of the correspondence is shown, together with the limits on applicability where stress-free boundaries near the stress concentrating feature are present or adjacent features interact. Examples are given which compare parametric results derived from FEA with closed-form solutions based on the proposed method. New information is given on the stress state at a 90° corner or width step, where the magnitude of the stress field intensity is related to that of the corresponding crack geometry. This correspondence enables the user to extend further the application of crack-tip stress-field intensity information to square-cornered steps, external U-grooves, and internal cut-outs

    The B_s and D_s decay constants in 3 flavor lattice QCD

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    Capitalizing on recent advances in lattice QCD, we present a calculation of the leptonic decay constants f_{B_s} and f_{D_s} that includes effects of one strange sea quark and two light sea quarks. The discretization errors of improved staggered fermion actions are small enough to simulate with 3 dynamical flavors on lattices with spacings around 0.1 fm using present computer resources. By shedding the quenched approximation and the associated lattice scale ambiguity, lattice QCD greatly increases its predictive power. NRQCD is used to simulate heavy quarks with masses between 1.5 m_c and m_b. We arrive at the following results: f_{B_s} = 260 \pm 7 \pm 26 \pm 8 \pm 5 MeV and f_{D_s} = 290 \pm 20 \pm 29 \pm 29 \pm 6 MeV. The first quoted error is the statistical uncertainty, and the rest estimate the sizes of higher order terms neglected in this calculation. All of these uncertainties are systematically improvable by including another order in the weak coupling expansion, the nonrelativistic expansion, or the Symanzik improvement program.Comment: 4 page

    Effect of polar discontinuity on the growth of LaNiO3/LaAlO3 superlattices

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    We have conducted a detailed microscopic investigation of [LaNiO3(1 u.c.)/LaAlO3(1 u.c.)]N superlattices grown on (001) SrTiO3 and LaAlO3 to explore the influence of polar mismatch on the resulting electronic and structural properties. Our data demonstrate that the initial growth on the non-polar SrTiO3 surface leads to a rough morphology and unusual 2+ valence of Ni in the first LaNiO3 layer, which is not observed after growth on the polar surface of LaAlO3. A newly devised model suggests that the polar mismatch can be resolved if the perovskite layers grow with an excess of LaO, which also accounts for the observed electronic, chemical, and structural effects.Comment: 3 pages, 3 figure

    RNA sequence and the nature of the CuA-binding site in cytochrome c oxidase

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    AbstractFor cytochrome c oxidase subunit II (COXII), DNA and protein sequences suggest that Met-207 (bovine numbering) is conserved in all species except plants. Sequencing of plant mitochondrial COXII mRNAs now indicates that Met-207 is also conserved among plants as a result of a C-to-U type of RNA editing. Considering the strict evolutionary conservation of Met-207 and the homology of COXII to type I (blue) copper proteins and nitrous oxide reductase, we propose a model in which Met-207 is associated with the CuA-binding site (along with Cys-196, Cys-200 and His-204) and plays a role in determining its reduction potential and stability

    Tergitol enables the rapid and inexpensive scoring of nutritional and drug-resistance markers in the progeny of Neurospora crassa genetic crosses

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    After cultures from the progeny ascospores of a genetic cross containing nutritional markers are obtained, it is often necessary to test them on a variety of media. Testing using individual culture tubes may be ideal, but is time consuming. In contrast, inoculation of plates with conidial suspensions is relatively quick

    Evaluation of Pt, Ni, and Ni–Mo electrocatalysts for hydrogen evolution on crystalline Si electrodes

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    The dark electrocatalytic and light photocathodic hydrogen evolution properties of Ni, Ni–Mo alloys, and Pt on Si electrodes have been measured, to assess the viability of earth-abundant electrocatalysts for integrated, semiconductor coupled fuel formation. In the dark, the activities of these catalysts deposited on degenerately doped p^+-Si electrodes increased in the order Ni < Ni–Mo ≤ Pt. Ni–Mo deposited on degenerately doped Si microwires exhibited activity that was very similar to that of Pt deposited by metal evaporation on planar Si electrodes. Under 100 mW cm^(−2) of Air Mass 1.5 solar simulation, the energy conversion efficiencies of p-type Si/catalyst photoelectrodes ranged from 0.2–1%, and increased in the order Ni ≈ Ni–Mo < Pt, due to somewhat lower photovoltages and photocurrents for p-Si/Ni–Mo relative to p-Si/Ni and p-Si/Pt photoelectrodes. Deposition of the catalysts onto microwire arrays resulted in higher apparent catalytic activities and similar photoelectrode efficiencies than were observed on planar p-Si photocathodes, despite lower light absorption by p-Si in the microwire structures

    Diversity in the organization of elastin bundles and intramembranous muscles in bat wings

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    Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross‐polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the constituents of the skin of the wing likely plays a key role in shaping wings during flight

    Moral Panics and Punctuated Equilibrium in Public Policy: An Analysis of the Criminal Justice Policy Agenda in Britain

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    How and when issues are elevated onto the political agenda is a perennial question in the study of public policy. This article considers how moral panics contribute to punctuated equilibrium in public policy by drawing together broader societal anxieties or fears and thereby precipitating or accelerating changes in the dominant set of issue frames. In so doing they create opportunities for policy entrepreneurs to disrupt the existing policy consensus. In a test of this theory, we assess the factors behind the rise of crime on the policy agenda in Britain between 1960 and 2010. We adopt an integrative mixed-methods approach, drawing upon a combination of qualitative and quantitative data. This enables us to analyze the rise of crime as a policy problem, the breakdown of the political-institutional consensus on crime, the moral panic that followed the murder of the toddler James Bulger in 1993, the emergence of new issue frames around crime and social/moral decay more broadly, and how—in combination—these contributed to an escalation of political rhetoric and action on crime, led by policy entrepreneurs in the Labour and Conservative parties
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