423 research outputs found

    Dichopetala And New Related North American Genera: A Study In Genitalic Similarity In Sympatry And Genitalic Differences In Allopatry (Tettigoniidae: Phaneropterinae: Odonturini)

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    The genus Dichopetala Brunner von Wattenwyl, 1878 sensu Rehn and Hebard, 1914 is revised, with the description of 6 new genera and 14 new species...http://deepblue.lib.umich.edu/bitstream/2027.42/122723/1/OLD_MP_203.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122723/2/OLD_MP_203_sm.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122723/3/Dichopetala Locality Database.xlshttp://deepblue.lib.umich.edu/bitstream/2027.42/122723/4/Dichopetala Tables for Diagnosis.xlshttp://deepblue.lib.umich.edu/bitstream/2027.42/122723/8/MP_203-REV2.pdfDescription of OLD_MP_203.pdf : OLD: MP 203 high res. [Superseded]Description of OLD_MP_203_sm.pdf : OLD: MP 203 lo res. [Superseded]Description of Dichopetala Locality Database.xls : DatasetDescription of Dichopetala Tables for Diagnosis.xls : Datase

    The Clustering of Massive Halos

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    The clustering properties of dark matter halos are a firm prediction of modern theories of structure formation. We use two large volume, high-resolution N-body simulations to study how the correlation function of massive dark matter halos depends upon their mass and formation history. We find that halos with the lowest concentrations are presently more clustered than those of higher concentration, the size of the effect increasing with halo mass; this agrees with trends found in studies of lower mass halos. The clustering dependence on other characterizations of the full mass accretion history appears weaker than the effect with concentration. Using the integrated correlation function, marked correlation functions, and a power-law fit to the correlation function, we find evidence that halos which have recently undergone a major merger or a large mass gain have slightly enhanced clustering relative to a randomly chosen population with the same mass distribution.Comment: 10 pages, 8 figures; text improved, references and one figure added; accepted for publication in Ap

    Sentiment analysis with genetically evolved Gaussian kernels

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    Sentiment analysis consists of evaluating opinions or statements based on text analysis. Among the methods used to estimate the degree to which a text expresses a certain sentiment are those based on Gaussian Processes. However, traditional Gaussian Processes methods use a prede- fined kernels with hyperparameters that can be tuned but whose structure can not be adapted. In this paper, we propose the application of Genetic Programming for the evolution of Gaussian Process kernels that are more precise for sentiment analysis. We use use a very flexible representation of kernels combined with a multi-objective approach that considers si- multaneously two quality metrics and the computational time required to evaluate those kernels. Our results show that the algorithm can outper- form Gaussian Processes with traditional kernels for some of the sentiment analysis tasks considered

    Fast Algorithms For Josephson Junction Arrays : Bus--bars and Defects

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    We critically review the fast algorithms for the numerical study of two--dimensional Josephson junction arrays and develop the analogy of such systems with electrostatics. We extend these procedures to arrays with bus--bars and defects in the form of missing bonds. The role of boundaries and of the guage choice in determing the Green's function of the system is clarified. The extension of the Green's function approach to other situations is also discussed.Comment: Uuencoded 1 Revtex file (11 Pages), 3 Figures : Postscript Uuencode

    The engine reformer: Syngas production in an engine for compact gas-to-liquids synthesis

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    Methane (CH[subscript 4]) reforming was carried out in an internal combustion engine (an “engine reformer”). We successfully produced syngas from the partial oxidation of natural gas in the cylinder of a diesel engine that was reconfigured to perform spark ignition. Performing the reaction in an engine cylinder allows some of the exothermicity to be captured as useful work. Intake conditions of 110 kPa and up to 480 °C allowed low cycle-to-cycle variability (COV[subscript nimep]  2.4, but < 1 mg/L below these equivalence ratios. These results demonstrate that the engine reformer could be a key component of a compact gas-to-liquids synthesis plant by highlighting the operating conditions under which high gas conversion, high H[subscript 2]-to-CO ratios close to 2.0, and low soot production are possible.United States. Advanced Research Projects Agency-Energy (Award DE-AR0000506)Research Triangle InitiativeMIT Energy InitiativeMassachusetts Institute of Technology. Tata Center for Technology and Desig

    HIV Prevention in Care and Treatment Settings: Baseline Risk Behaviors among HIV Patients in Kenya, Namibia, and Tanzania.

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    HIV care and treatment settings provide an opportunity to reach people living with HIV/AIDS (PLHIV) with prevention messages and services. Population-based surveys in sub-Saharan Africa have identified HIV risk behaviors among PLHIV, yet data are limited regarding HIV risk behaviors of PLHIV in clinical care. This paper describes the baseline sociodemographic, HIV transmission risk behaviors, and clinical data of a study evaluating an HIV prevention intervention package for HIV care and treatment clinics in Africa. The study was a longitudinal group-randomized trial in 9 intervention clinics and 9 comparison clinics in Kenya, Namibia, and Tanzania (N = 3538). Baseline participants were mostly female, married, had less than a primary education, and were relatively recently diagnosed with HIV. Fifty-two percent of participants had a partner of negative or unknown status, 24% were not using condoms consistently, and 11% reported STI symptoms in the last 6 months. There were differences in demographic and HIV transmission risk variables by country, indicating the need to consider local context in designing studies and using caution when generalizing findings across African countries. Baseline data from this study indicate that participants were often engaging in HIV transmission risk behaviors, which supports the need for prevention with PLHIV (PwP). TRIAL REGISTRATION: ClinicalTrials.gov NCT01256463

    Varying uses of the ABCD2 scoring system in primary and secondary care: a qualitative study.

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    OBJECTIVES: To explore the usage of the ABCD2 risk stratification score by general practitioners (GPs) and hospital staff during the referral of patients with suspected transient ischaemic attack (TIA) or minor stroke. DESIGN: Qualitative study using semistructured interviews. SETTING: Nine general practices and two hospital sites in England (Birmingham and Cambridge). PARTICIPANTS: Nine GPs and nine hospital staff (two consultants, four nurses, two ultrasonographers and one administrator). RESULTS: In both sites, clinicians used a referral proforma based around the ABCD2 scoring system for a range of purposes including self-education, to assist emphasising urgency to the patient, as a referral pathway facilitator and as a diagnostic tool. Negative views of its role included potential medicolegal threats, that it was a barrier to appropriate care, and led to misdiagnoses. Despite having differing uses by different clinicians, the ABCD2 proforma was the central means of interprofessional communication in TIA referrals across both sites. CONCLUSIONS: Understanding how prediction rules are used in practice is key to determining their impact on processes of care and clinical outcomes. In practice, GPs and their colleagues use the ABCD2 score in subtly different ways and it functions as a 'boundary object' by both accommodating these multiple purposes, yet still successfully aiding communication between them

    Pyrite-induced hydroxyl radical formation and its effect on nucleic acids

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    BACKGROUND: Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested. RESULTS: Using a combination of electron spin resonance (ESR) spin-trapping techniques and scavenging reactions involving nucleic acids, the formation of hydroxyl radicals in pyrite/aqueous suspensions is demonstrated. The addition of EDTA to pyrite slurries inhibits the hydrogen peroxide-to-hydroxyl radical conversion, but does not inhibit the formation of hydrogen peroxide. Given the stability of EDTA chelation with both ferrous and ferric iron, this suggests that the addition of the EDTA prevents the transformation by chelation of dissolved iron species. CONCLUSION: While the exact mechanism or mechanisms of the hydrogen peroxide-to-hydroxyl radical conversion cannot be resolved on the basis of the experiments reported in this study, it is clear that the pyrite surface promotes the reaction. The formation of hydroxyl radicals is significant because they react nearly instantaneously with most organic molecules. This suggests that the presence of pyrite in natural, engineered, or physiological aqueous systems may induce the transformation of a wide range of organic molecules. This finding has implications for the role pyrite may play in aquatic environments and raises the question whether inhalation of pyrite dust contributes to the development of lung diseases

    ‘It Takes Two Hands to Clap’: How Gaddi Shepherds in the Indian Himalayas Negotiate Access to Grazing

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    This article examines the effects of state intervention on the workings of informal institutions that coordinate the communal use and management of natural resources. Specifically it focuses on the case of the nomadic Gaddi shepherds and official attempts to regulate their access to grazing pastures in the Indian Himalayas. It is often predicted that the increased presence of the modern state critically undermines locally appropriate and community-based resource management arrangements. Drawing on the work of Pauline Peters and Francis Cleaver, I identify key instances of socially embedded ‘common’ management institutions and explain the evolution of these arrangements through dynamic interactions between individuals, communities and the agents of the state. Through describing the ‘living space’ of Gaddi shepherds across the annual cycle of nomadic migration with their flocks I explore the ways in which they have been able to creatively reinterpret external interventions, and suggest how contemporary arrangements for accessing pasture at different moments of the annual cycle involve complex combinations of the formal and the informal, the ‘traditional’ and the ‘modern’
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