13,055 research outputs found

    The State of the Death Penalty

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    The death penalty is in decline in America and most death penalty states do not regularly impose death sentences. In 2016 and 2017, states reached modern lows in imposed death sentences, with just thirty-one defendants sentenced to death in 2016 and thirty-nine in 2017, as compared with over three hundred per year in the 1990s. In 2016, only thirteen states imposed death sentences, and in 2017, fourteen did so, although thirty-one states retain the death penalty. What explains this remarkable and quite unexpected trend? In this Article, we present new analysis of state-level legislative changes that might have been expected to impact death sentences. First, life without parole (LWOP) statutes, now enacted in nearly every state, might have been expected to reduce death sentences because they give jurors a non-capital option at trial. Second, legislatures have moved, albeit at varying paces, to comply with the Supreme Court’s holding in Ring v. Arizona, which requires that the final decision in capital sentencing be made not by a judge, but by a jury. Third, states at different times have created state-wide public defender offices to represent capital defendants at trial. In addition, the decline in homicides and homicide rates could be expected to contribute to the decline in state-level death sentencing. We find that contrary to the expectations of many observers, changes in the law such as adoption of LWOP and jury sentencing, did not consistently or significantly impact death sentencing. The decline in homicides and homicide rates is correlated with changes in death sentencing at the state level. However, this Article finds that state provision of capital trial representation is far more strongly and robustly correlated with reduced death sentencing than these other factors. The findings bolster the argument that adequacy of counsel has greater implications for the administration of the death penalty than other legal factors. These findings also have implications beyond the death penalty and they underscore the importance of a structural understanding of the Sixth Amendment right to counsel in our system of criminal justice

    Fatigue behavior of flexhoses and bellows due to flow-induced vibrations

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    The analysis and results developed in a fresh approach to calculate flow induced vibration response of a flexible flow passage are summarized. The vibration results are further examined in the frequency domain to obtain dominant frequency information. A cumulative damage analysis due to cyclic strains is performed to obtain the number of cycles to failure for a metallic bellows of particular specifications under a variety of operational conditions. Sample plots of time and frequency domain responses are included. The complex listing of a computer program is provided. The program successively executes each of the analyses needed to calculate the vibration response, the frequency response, the cyclic strains and the number of cycles to failure. The program prompts the user for necessary input information. Sample data from the program is provided. The fatigue life results obtained by the computer model lie within an acceptable range of previously measured available data

    Development and demonstration of an on-board mission planner for helicopters

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    Mission management tasks can be distributed within a planning hierarchy, where each level of the hierarchy addresses a scope of action, and associated time scale or planning horizon, and requirements for plan generation response time. The current work is focused on the far-field planning subproblem, with a scope and planning horizon encompassing the entire mission and with a response time required to be about two minutes. The far-feld planning problem is posed as a constrained optimization problem and algorithms and structural organizations are proposed for the solution. Algorithms are implemented in a developmental environment, and performance is assessed with respect to optimality and feasibility for the intended application and in comparison with alternative algorithms. This is done for the three major components of far-field planning: goal planning, waypoint path planning, and timeline management. It appears feasible to meet performance requirements on a 10 Mips flyable processor (dedicated to far-field planning) using a heuristically-guided simulated annealing technique for the goal planner, a modified A* search for the waypoint path planner, and a speed scheduling technique developed for this project

    Observations of cosmic gamma-ray bursts with IMP-7: Evidence for a single spectrum

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    Spectral observation of nine recent cosmic gamma-ray bursts are reported. The average photon number spectra of all nine events are shown to be consistent with a 150-keV exponential from 100 keV to about 400 keV, and a power law of index -2.5 from 400 keV to 1100 keV. The observations also indicate an event rate of 16 in 1972 and 1973, or 8 + or - 2 per year, higher than the 5 + or - 1 per year initially reported. This corresponds to an approximately 40-percent lower effective intensity threshold, attained by using more sensitive detectors in multiple-satellite coincidence

    Clonal Interference, Multiple Mutations, and Adaptation in Large Asexual Populations

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    Two important problems affect the ability of asexual populations to accumulate beneficial mutations, and hence to adapt. First, clonal interference causes some beneficial mutations to be outcompeted by more-fit mutations which occur in the same genetic background. Second, multiple mutations occur in some individuals, so even mutations of large effect can be outcompeted unless they occur in a good genetic background which contains other beneficial mutations. In this paper, we use a Monte Carlo simulation to study how these two factors influence the adaptation of asexual populations. We find that the results depend qualitatively on the shape of the distribution of the effects of possible beneficial mutations. When this distribution falls off slower than exponentially, clonal interference alone reasonably describes which mutations dominate the adaptation, although it gives a misleading picture of the evolutionary dynamics. When the distribution falls off faster than exponentially, an analysis based on multiple mutations is more appropriate. Using our simulations, we are able to explore the limits of validity of both of these approaches, and we explore the complex dynamics in the regimes where neither are fully applicable.Comment: 24 pages, 5 figure

    The Goddard program of gamma ray transient astronomy

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    Gamma ray burst studies are reviewed. The past results, present status and future expectations are outlined regarding endeavors using experiments on balloons, IMP-6 and -7, OGO-3, ISEE-1 and -3, Helios-2, Solar Maximum Mission, the Einstein Observatory, Solar Polar and the Gamma Ray Observatory, and with the interplanetary gamma ray burst networks, to which some of these spacecraft sensors contribute. Additional emphasis is given to the recent discovery of a new type of gamma ray transient, detected on 1979 March 5

    Placental-mediated increased cytokine response to lipopolysaccharides: a potential mechanism for enhanced inflammation susceptibility of the preterm fetus.

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    BackgroundCerebral palsy is a nonprogressive motor impairment syndrome that has no effective cure. The etiology of most cases of cerebral palsy remains unknown; however, recent epidemiologic data have demonstrated an association between fetal neurologic injury and infection/inflammation. Maternal infection/inflammation may be associated with the induction of placental cytokines that could result in increased fetal proinflammatory cytokine exposure, and development of neonatal neurologic injury. Therefore, we sought to explore the mechanism by which maternal infection may produce a placental inflammatory response. We specifically examined rat placental cytokine production and activation of the Toll-like receptor 4 (TLR4) pathway in response to lipopolysaccharide exposure at preterm and near-term gestational ages.MethodsPreterm (e16) or near-term (e20) placental explants from pregnant rats were treated with 0, 1, or 10 μg/mL lipopolysaccharide. Explant integrity was assessed by lactate dehydrogenase assay. Interleukin-6 and tumor necrosis alpha levels were determined using enzyme-linked immunosorbent assay kits. TLR4 and phosphorylated nuclear factor kappa light chain enhancer of activated B cells (NFκB) protein expression levels were determined by Western blot analysis.ResultsAt both e16 and e20, lactate dehydrogenase levels were unchanged by treatment with lipopolysaccharide. After exposure to lipopolysaccharide, the release of interleukin-6 and tumor necrosis alpha from e16 placental explants increased by 4-fold and 8-9-fold, respectively (P < 0.05 versus vehicle). Conversely, interleukin-6 release from e20 explants was not significantly different compared with vehicle, and tumor necrosis alpha release was only 2-fold higher (P < 0.05 versus vehicle) following exposure to lipopolysaccharide. Phosphorylated NFκB protein expression was significantly increased in the nuclear fraction from placental explants exposed to lipopolysaccharide at both e16 and e20, although TLR4 protein expression was unaffected.ConclusionLipopolysaccharide induces higher interleukin-6 and tumor necrosis alpha expression at e16 versus e20, suggesting that preterm placentas may have a greater placental cytokine response to lipopolysaccharide infection. Furthermore, increased phosphorylated NFκB indicates that placental cytokine induction may occur by activation of the TLR4 pathway
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