11,365 research outputs found

    The Four Horsemen of the Apocalypse: Understanding Human Security

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    Since the end of the Cold War, security studies have broadened to take into account a wide range of non-military threats ranging from poverty to environmental concerns rather than just national defense. Security scholars, backed by international organizations and a growing number of national governments, have developed the concept of Human Security, focusing on the welfare of ordinary people against a broad range of threats. This has aroused vigorous debate. Part I of this paper proposes an analytical model of Human Security. Part II argues that it is important to measure how ordinary people perceive risks, moving beyond state-centric notions of Human Security. We examine new evidence, drawing upon survey items specially designed to monitor perceptions of Human Security, included for the first time in the 6th wave of the World Values Survey (WVS), with fieldwork conducted in 2010-2012. Part III demonstrates that people distinguish three dimensions: national, community, and personal security and then explores some structural determinants driving these perceptions. Part IV discusses why perceptions of Human Security matter, in particular for explaining cultural values and value change around the world. The conclusion argues that the shift from a narrow focus on military security toward the broader concept of Human Security is a natural response to the changing challenges facing developed societies, in which the cost-benefit ratio concerning war has become negative and cultural changes have made war less acceptable. In this setting, valid measures of perceptions of Human Security have become essential, both to understand the determinants of Human Security among ordinary people, and to analyze their consequences.

    Coping with speaker-related variation via abstract phonemic categories

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    Listeners can cope with considerable variation in the way that different speakers talk. We argue here that they can do so because of a process of phonological abstraction in the speech-recognition system. We review evidence that listeners adjust the bounds of phonemic categories after only very limited exposure to a deviant realisation of a given phoneme. This learning can be talker-specific and is stable over time; further, the learning generalizes to previously unheard words containing the deviant phoneme. Together these results suggest that the learning involves adjustment of prelexical phonemic representations which mediate between the speech signal and the mental lexicon during word recognition. We argue that such an abstraction process is inconsistent with claims made by some recent models of language processing that the mental lexicon consists solely of multiple detailed traces of acoustic episodes. Simulations with a purely episodic model without functional prelexical abstraction confirm that such a model cannot account for the evidence on lexical generalization of perceptual learning. We conclude that abstract phonemic categories form a necessary part of lexical access, and that the ability to store talker-specific knowledge about those categories provides listeners with the means to deal with cross-talker variation

    Evaluations of Space Shielding

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    A general method of evaluating the efficiency of space vehicle shielding is developed and used to compare various active and passive systems for protection against ionizing radiation. Available permanent magnets are found useless for active shielding, and combined active-passive systems in general are determined to be inefficient. On the other hand, evaluations show that active electrostatic shielding may have possibilities for weight savings if electrical conditions (presently unknown) are favorable therefor in space. Further, a positive potential improvement is calculated for an active shielding system which utilizes superconducting Nb3Sn to provide a confined magnetic flux to deflect incident charged particles; this potential points toward substantial reductions in shield weight for the protection of large vehicles from highly energetic particles. Recommendations are made for further research, particularly for flight experiments to measure directionality of solar flare protons

    Realistic Ionizing Fluxes for Young Stellar Populations from 0.05 to twice solar metallicity

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    We present a new grid of ionizing fluxes for O and Wolf-Rayet stars for use with evolutionary synthesis codes and single star H II region analyses. A total of 230 expanding, non-LTE, line-blanketed model atmospheres have been calculated for five metallicities (0.05, 0.2, 0.4, 1 and 2 solar) using the WM-basic code of Pauldrach et al. (2001) and the CMFGEN code of Hillier & Miller (1998). The stellar wind parameters are scaled with metallicity for both O and W-R stars. We incorporate the new models into Starburst99 (Leitherer et al. 1999) and compare the ionizing outputs with Schaerer & Vacca (1998) and Leitherer et al. (1999). The changes in the output ionizing fluxes are dramatic, particularly below 228 A. We also find lower fluxes in the He I continuum for Z > 0.4 solar and ages < 7 Myr because of the increased line blanketing. We test the accuracy of the new models by constructing photoionization models. We show that for the dwarf O star grid, He I 5876/H beta decreases between Z = 1 and twice solar in a similar manner to observations (e.g. Bresolin et al. 1999) due to the increased effect of line blanketing. We therefore suggest that a lowering of the upper mass limit at high abundances is not required to explain the observations. For the case of an instantaneous burst, we plot the softness parameter "eta prime" against the abundance indicator R_23. The new models are coincident with the data of Bresolin et al. (1999), particularly during the W-R phase, unlike previous models which over-predict the hardness of the ionizing radiation.Comment: 21 pages, 15 postscript colour figures, includes mn2e.cls. To be published in MNRAS. Revised version containing modifications to Tables 1-

    Association of Factor V Secretion with Protein Kinase B Signaling in Platelets from Horses with Atypical Equine Thrombasthenia.

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    BackgroundTwo congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation.Hypothesis/objectivesPlatelet dysfunction in horses with this second thrombasthenia results from a secretory defect.AnimalsTwo affected and 6 clinically normal horses.MethodsEx vivo study. Washed platelets were examined for (1) expression of the αIIb-β3 integrin; (2) fibrinogen binding capacity in response to ADP and thrombin; (3) secretion of dense and α-granules; (4) activation of the mammalian target of rapamycin (mTOR)-protein kinase B (AKT) signaling pathway; and (5) cellular distribution of phosphatidylinositol-4-phosphate-3-kinase, class 2B (PIK3C2B) and SH2 containing inositol-5'-phosphatase 1 (SHIP1).ResultsPlatelets from affected horses expressed normal amounts of αIIb-β3 integrin and bound fibrinogen normally in response to ADP, but bound 80% less fibrinogen in response to thrombin. α-granules only released 50% as much Factor V as control platelets, but dense granules released their contents normally. Protein kinase B (AKT) phosphorylation was reduced after thrombin activation, but mTOR Complex 2 (mTORC2) and phosphoinositide-dependent kinase 1 (PDK1) signaling were normal. SH2-containing inositol-5'-phosphatase 1 (SHIP1) did not localize to the cytoskeleton of affected platelets and was decreased overall consistent with reduced AKT phosphorylation.Conclusions and clinical significanceDefects in fibrinogen binding, granule secretion, and signal transduction are unique to this thrombasthenia, which we designate as atypical equine thrombasthenia

    Approximation of the acoustic radiation impedance of a cylindrical pipe

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    Useful approximation formulae for radiation impedance are given for the reflection coefficients of both infinitely flanged and unflanged rigid-walled cylindrical ducts. The expressions guarantee that simple but necessary physical and mathematical principles are met, like hermitian symmetry for the reflection coefficient (identical behaviour of positive and negative frequencies) and causality for the impulse response. A non causal but more accurate expression is also proposed that is suitable for frequency-domain applications. The formulae are obtained by analytical and numerical fitting to reference results from Levine & Schwinger for the unflanged case and extracted from the radiation impedance matrix given by Zorumski for the infinite flanged case.Comment: Journal of Sound and Vibration (2008) accepte

    Comparison of selected submicron powder blending methods for dispersion alloys

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    Wet and dry blending nickel-aluminum oxide submicron powders for dispersion-strengthened alloy

    Request for Proposal Automated Data Processing Equipment and Software for the Papio Natural Resources District

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    This Request for Proposal (RFP) is submitted to solicit proposals from qualified vendors of computer hardware, software, and support for the Papio Natural Resources District. In order to receive consideration, a proposed system must meet the requirements of the Papio Natural Resources District as herein described

    Data Processing and Information Management in the City of Omaha, Nebraska: Analysis and Recommendations

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    The city of Omaha has an extensive and complex data processing system. It is so large, in fact, that no single person inside or out of city government is fully knowledgeable about it. The system as it exists today cannot be described as an information management system as it is neither coordinated nor comprehensive. It consists instead of numerous components that have come together over time without the benefit of an overall plan or clear policy direction. The system is rarely viewed from a citywide perspective or from the perspective of providing information required by management for operational and planning purposes. Rather, it is viewed from the perspective of individual departments or divisions as a component of city operations that collects something called data and produces something called reports

    Microcomputers and Local Government: A Handbook -- Instructors\u27 Manual

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    This handbook, and its accompanying instructor\u27s manual, was written to be used with a one- or two-day workshop on microcomputers and local governments. The handbook was designed· for the local government official with little or no familiarity with microcomputers and their applications to the world of government
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