14,749 research outputs found

    Self-Employment and Risk Preference

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    We explore the relationship between self-employment and attitudes towards financial risk using individual level data drawn from the U.S. Survey of Consumer Finances (SCF) and the U.S. Panel Study of Income Dynamics (PSID). Both surveys include questions, which enable us to construct measures of an individual´s willingness to take risk allowing us to explore the implications of interpersonal differences in risk preference for the probability and success of self-employment. Our empirical findings suggest that willingness to take financial risk is positively associated with both the incidence and success of self-employment. We find that this relationship is particularly pronounced in cases where the individual actually started the business. Finally, we exploit the panel aspect of the PSID and find evidence consistent with a causal relationship between attitudes towards risk and self-employment with attitudes towards risk measured over 1969-1972 (i.e. prior to becoming self-employed) having a statistically significant positive influence on the probability of self-employment in 1996

    Temporal And Spatial Turbulent Spectra Of MHD Plasma And An Observation Of Variance Anisotropy

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    The nature of magnetohydrodynamic (MHD) turbulence is analyzed through both temporal and spatial magnetic fluctuation spectra. A magnetically turbulent plasma is produced in the MHD wind tunnel configuration of the Swarthmore Spheromak Experiment. The power of magnetic fluctuations is projected into directions perpendicular and parallel to a local mean field; the ratio of these quantities shows the presence of variance anisotropy which varies as a function of frequency. Comparisons among magnetic, velocity, and density spectra are also made, demonstrating that the energy of the turbulence observed is primarily seeded by magnetic fields created during plasma production. Direct spatial spectra are constructed using multi-channel diagnostics and are used to compare to frequency spectra converted to spatial scales using the Taylor hypothesis. Evidence for the observation of dissipation due to ion inertial length scale physics is also discussed, as well as the role laboratory experiments can play in understanding turbulence typically studied in space settings such as the solar wind. Finally, all turbulence results are shown to compare fairly well to a Hall-MHD simulation of the experiment

    Patient Perceptions of Drug Risks and Benefits

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    This is a report of a pilot study conducted to examine patients\u27 perceptions of drug Risks and benefits. While all of the factors influencing such perceptions are important, the findings about the extent to which views are affected by patient understanding of and confidence in regulatory oversight should be of professional interest to an especially broad audience

    Turbulence Analysis Of An Experimental Flux-Rope Plasma

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    We have previously generated elongated Taylor double-helix flux-rope plasmas in the SSX MHD wind tunnel. These plasmas are remarkable in their rapid relaxation (about one Alfven time) and their description by simple analytical Taylor force-free theory despite their high plasma beta and high internal flow speeds. We report on the turbulent features observed in these plasmas including frequency spectra, autocorrelation function, and probability distribution functions of increments. We discuss here the possibility that the turbulence facilitating access to the final state supports coherent structures and intermittency revealed by non-Gaussian signatures in the statistics. Comparisons to a Hall-MHD simulation of the SSX MHD wind tunnel show similarity in several statistical measures

    1I/2017 U1 (`Oumuamua) is Hot: Imaging, Spectroscopy and Search of Meteor Activity

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    1I/2017 U1 (`Oumuamua), a recently discovered asteroid in a hyperbolic orbit, is likely the first macroscopic object of extrasolar origin identified in the solar system. Here, we present imaging and spectroscopic observations of \textquoteleft Oumuamua using the Palomar Hale Telescope as well as a search of meteor activity potentially linked to this object using the Canadian Meteor Orbit Radar. We find that \textquoteleft Oumuamua exhibits a moderate spectral gradient of 10%±6% (100 nm)−110\%\pm6\%~(100~\mathrm{nm})^{-1}, a value significantly lower than that of outer solar system bodies, indicative of a formation and/or previous residence in a warmer environment. Imaging observation and spectral line analysis show no evidence that \textquoteleft Oumuamua is presently active. Negative meteor observation is as expected, since ejection driven by sublimation of commonly-known cometary species such as CO requires an extreme ejection speed of ∼40\sim40 m s−1^{-1} at ∼100\sim100 au in order to reach the Earth. No obvious candidate stars are proposed as the point of origin for \textquoteleft Oumuamua. Given a mean free path of ∼109\sim10^9 ly in the solar neighborhood, \textquoteleft Oumuamua has likely spent a very long time in the interstellar space before encountering the solar system.Comment: ApJL in pres

    TELL ME HOW THIS BEGINS: INSURGENCY IN THE UNITED STATES

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    In recent years, the United States has exhibited sustained socio-political violence and extremism. This thesis investigates whether the United States is experiencing a pre-insurgency state in the insurgency life cycle. A comparative analysis, utilizing domestic insurgency markers provided by the Central Intelligence Agency’s Guide to the Analysis of Insurgency, examines historical domestic insurgencies in Colombia, Northern Ireland, and North Carolina against the current socio-political environment in the United States. This analysis suggests that the United States is exhibiting characteristics of an open domestic insurgency, as demonstrated in the case studies. This thesis recommends enacting necessary political reforms and instating a national year of service, administered by the U.S. military and modeled after the Israeli Defense Forces.Civilian, Spartanburg County Emergency ServicesApproved for public release. Distribution is unlimited
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