3,000 research outputs found

    An Interview with Milton Friedman

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    Fabrication and Testing of Low Cost 2D Carbon-Carbon Nozzle Extensions at NASA/MSFC

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    Subscale liquid engine tests were conducted at NASA/MSFC using a 1.2 Klbf engine with liquid oxygen (LOX) and gaseous hydrogen. Testing was performed for main-stage durations ranging from 10 to 160 seconds at a chamber pressure of 550 psia and a mixture ratio of 5.7. Operating the engine in this manner demonstrated a new and affordable test capability for evaluating subscale nozzles by exposing them to long duration tests. A series of 2D C-C nozzle extensions were manufactured, oxidation protection applied and then tested on a liquid engine test facility at NASA/MSFC. The C-C nozzle extensions had oxidation protection applied using three very distinct methods with a wide range of costs and process times: SiC via Polymer Impregnation & Pyrolysis (PIP), Air Plasma Spray (APS) and Melt Infiltration. The tested extensions were about 6" long with an exit plane ID of about 6.6". The test results, material properties and performance of the 2D C-C extensions and attachment features will be discussed

    Big data and data repurposing – using existing data to answer new questions in vascular dementia research

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    Introduction: Traditional approaches to clinical research have, as yet, failed to provide effective treatments for vascular dementia (VaD). Novel approaches to collation and synthesis of data may allow for time and cost efficient hypothesis generating and testing. These approaches may have particular utility in helping us understand and treat a complex condition such as VaD. Methods: We present an overview of new uses for existing data to progress VaD research. The overview is the result of consultation with various stakeholders, focused literature review and learning from the group’s experience of successful approaches to data repurposing. In particular, we benefitted from the expert discussion and input of delegates at the 9th International Congress on Vascular Dementia (Ljubljana, 16-18th October 2015). Results: We agreed on key areas that could be of relevance to VaD research: systematic review of existing studies; individual patient level analyses of existing trials and cohorts and linking electronic health record data to other datasets. We illustrated each theme with a case-study of an existing project that has utilised this approach. Conclusions: There are many opportunities for the VaD research community to make better use of existing data. The volume of potentially available data is increasing and the opportunities for using these resources to progress the VaD research agenda are exciting. Of course, these approaches come with inherent limitations and biases, as bigger datasets are not necessarily better datasets and maintaining rigour and critical analysis will be key to optimising data use

    Persistence of self-recruitment and patterns of larval connectivity in a marine protected area network

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    The use of marine protected area (MPA) networks to sustain fisheries and conserve biodiversity is predicated on two critical yet rarely tested assumptions. Individual MPAs must produce sufficient larvae that settle within that reserve's boundaries to maintain local populations while simultaneously supplying larvae to other MPA nodes in the network that might otherwise suffer local extinction. Here, we use genetic parentage analysis to demonstrate that patterns of self-recruitment of two reef fishes (Amphiprion percula and Chaetodon vagabundus) in an MPA in Kimbe Bay, Papua New Guinea, were remarkably consistent over several years. However, dispersal from this reserve to two other nodes in an MPA network varied between species and through time. The stability of our estimates of self-recruitment suggests that even small MPAs may be self-sustaining. However, our results caution against applying optimization strategies to MPA network design without accounting for variable connectivity among species and over time

    Narcissism in Midlife: Longitudinal Changes in and Correlates of Women's Narcissistic Personality Traits

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    We examined changes in and correlates of 3 kinds of narcissism—hypersensitivity, willfulness, and autonomy—during middle adulthood. Few studies have examined narcissistic personality traits beyond young adulthood, and none has assessed longitudinal changes in narcissism during midlife. In a sample of 70 college‐educated women, we found that observer ratings of hypersensitive narcissism were associated with more negative outcomes at ages 43 and 53 (i.e., more depressive symptoms and physical health problems, lower life satisfaction and well‐being). Ratings of willfulness and autonomy predicted more positive outcomes. All 3 kinds of narcissism showed considerable rank‐order stability over 10 years, but there were also mean‐level changes: Hypersensitivity and autonomy decreased, whereas willfulness increased. More positive outcomes were associated with decreases in hypersensitivity and increases in willfulness and autonomy. However, in multivariate analyses, autonomy did not show any significant associations with women's health and well‐being outcomes, suggesting that it may have less predictive utility compared to hypersensitivity and willfulness. Our findings highlight developmental changes in and correlates of women's narcissistic personality traits and the importance of assessing different aspects of narcissism in midlife.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93646/1/jopy755.pd

    Designing indicators for assessing the effects of marine protected areas on coral reef ecosystems : a multidisciplinary standpoint

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    The present paper aims at identifying and assessing indicators of the effects of Marine Protected Areas (MPAs) in coral reef regions, based on a bibliography review in ecology, economics and social sciences. First the various effects Studied within each of these domains and the variables used to measure them were censused. Potential ecological indicators were assessed through their link with the question used (here termed "relevance") and their "effectiveness" which encompasses the issues of precision, accuracy and statistical power. Relevance and effectiveness were respectively measured by the frequency of use of each indicator and the proportion of significant results in the reviewed articles. For social and economic effects, the approach was not possible due to the low number of references: we thus discussed the issue of finding appropriate indicators for those fields. Results indicate: 1- the unbalance in literature between disciplines: 2- the need for protocols and methodologies which include controls in order to assess MPA effects: 3- an important proportion of ecological indicators with low effectiveness: 4- the large number of ecological effects still not studied or not demonstrated at present

    Soft-bottom fishes and spatial protection: findings from a temperate marine protected area

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    Numerous studies over the last decades have focused on marine protected areas (MPAs) and their effects on fish communities. However, there is a knowledge gap regarding how species that live associated with soft-substrates (e.g., sand, mud) respond to spatial protection. We analyzed abundance, biomass and total lengths of the soft-bottom fishes in a multiple-use MPA in the north-eastern Atlantic, the Luiz Saldanha Marine Park (Portugal), during and after the implementation of its management plan. Data were collected by experimental fishing in areas with three different levels of protection, during the implementation period and for three years after full implementation of the MPA. Univariate analysis detected significant biomass increases between the two periods. Fish assemblages were mainly structured by depth and substrate, followed by protection level. Community composition analyses revealed significant differences between protection levels and between the two periods. Species exhibited a broad variation in their response to protection, and we hypothesize that factors such as species habitat preferences, body size and late maturity might be underlying determinants. Overall, this study provides some evidence of protection effectiveness in soft-bottom fish communities, supported by the significant increase in biomass in the protected areas and the positive trends of some species.project LIFE-BIOMARES [LIFE06 NAT/P/000192]; project BUFFER (ERA-Net BiodivERsA); company SECIL-Companhia Geral de Cal e Cimento S.A.; FCT-Foundation for Science and Technology [CCMAR/Multi/04326/2013, SFRH/BD/80771/2011]; Foundation for Science and Technology [SFRH/BD/80771/2011]; 2012 Sesimbra Scientific Priz

    Making champs and super-champs - Current views, contradictions, and future directions

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    In our 2016 paper (Collins et al., 2016a), we proposed that superchamps (athletes who have achieved the highest level in their sport) were differentiated from their less successful counterparts by their use of positive proactive coping and a "learn from it" approach to challenge. This skill-based focus to talent development (TD) is supported extensively in the literature (e.g., MacNamara et al., 2010a,b) and suggests that the differences between levels of adult achievement relate more to what performers bring to the challenges than what they experience (Collins et al., 2016a). In this focused review we present and discuss a number of key concepts related to this paper and other parallel research in TD. We begin by presenting our pragmatic objectives and the importance of considering how we evaluate the research with an emphasis on its application to the applied setting. We then consider commonalities and differences in recent psychological approaches to TD, namely the experiential, attitudinal, and skill-based. The paper then provides further exploration of the Psychological Characteristics of Developing Excellence and their role in TD processes. We conclude with a consideration of future research and the application of research in TD. Reflecting our pragmatic stance as researchers, we hope that this focused review provides suggestions for progress and stimulates critical debate amongst practitioners, researchers and policy makers
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