880,582 research outputs found

    The Cost of Quality Out-of-School-Time Programs

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    Funders and program planners want to know: What does it cost to operate a high-quality after-school or summer program? This study answers that question, discovering that there is no "right" number. Cost varies substantially, depending on the characteristics of the participants, the goals of the program, who operates it and where it is located. Based on detailed cost data collected from 111 out-of-school-time programs in six cities, this report, along with an online calculator (www.wallacefoundation.org/cost-of-quality), provides cost averages and ranges for many common types of programs

    On the theory of the CO+OH reaction, including H and C kinetic isotope effects

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    The effect of pressure, temperature, H/D isotopes, and C isotopes on the kinetics of the OH+CO reaction are investigated using Rice-Ramsperger-Kassel-Marcus theory. Pressure effects are treated with a step-ladder plus steady-state model and tunneling effects are included. New features include a treatment of the C isotope effect and a proposed nonstatistical effect in the reaction. The latter was prompted by existing kinetic results and molecular-beam data of Simons and co-workers [J. Phys. Chem. A 102, 9559 (1998); J. Chem. Phys. 112, 4557 (2000); 113, 3173 (2000)] on incomplete intramolecular energy transfer to the highest vibrational frequency mode in HOCO*. In treating the many kinetic properties two small customary vertical adjustments of the barriers of the two transition states were made. The resulting calculations show reasonable agreement with the experimental data on (1) the pressure and temperature dependence of the H/D effect, (2) the pressure-dependent 12C/13C isotope effect, (3) the strong non-Arrhenius behavior observed at low temperatures, (4) the high-temperature data, and (5) the pressure dependence of rate constants in various bath gases. The kinetic carbon isotopic effect is usually less than 10 per mil. A striking consequence of the nonstatistical assumption is the removal of a major discrepancy in a plot of the kOH+CO/kOD+CO ratio versus pressure. A prediction is made for the temperature dependence of the OD+CO reaction in the low-pressure limit at low temperatures

    Judicial Activism of the Shari\u27ah Appeals Court in Israel (1994 - 2001): Rise and Crisis

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    The main thesis of this Article is that after 1994, with the nomination of new qadis to the Shari‘ah Court, a process of judicial activism began, which continues until this day. This process has been characterized by the qadis\u27 attempts to strengthen the position of the Shari‘ah Appeals Court. In some fields the qadis\u27 activism has been more successful than in others. Recently however, it seems that the Shari‘ah system is undergoing a crisis. The author will analyze the actions of the Shari‘ah Appeals Court on several parallel levels: (1) the strengthening of its position compared with those of the civil courts and the regional Shari‘ah Courts; and (2) a symbolic strengthening of its position in relation to (i) Israeli Law; (ii) the litigants and their attorneys; and (iii) the Muslim public. The author will then analyze the current crisis of the Shari‘ah system and the need for reform. The author will focus upon the internal dynamics of the Shari‘ah Court of Appeals, the interaction of its different actors, and suggest reforms to be made that will strengthen the legitimacy of its position in relation to the State of Israel and with the Muslim populous. Before proceeding to the analysis, however, some background regarding the religious Muslim world in Israel is necessary

    Inter-Epidemic Transmission of Rift Valley Fever in\ud Livestock in the Kilombero River Valley, Tanzania:\ud A Cross-Sectional Survey

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    In recent years, evidence of Rift Valley fever (RVF) transmission during inter-epidemic periods in parts of Africa has increasingly been reported. The inter-epidemic transmissions generally pass undetected where there is no surveillance in the livestock or human populations. We studied the presence of and the determinants for inter-epidemic RVF transmission in an area experiencing annual flooding in southern Tanzania. A cross-sectional sero-survey was conducted in randomly selected cattle, sheep and goats in the Kilombero river valley from May to August 2011, approximately four years after the 2006/07 RVF outbreak in Tanzania. The exposure status to RVF virus (RVFV) was determined using two commercial ELISA kits, detecting IgM and IgG antibodies in serum. Information about determinants was obtained through structured interviews with herd owners. An overall seroprevalence of 11.3% (n = 1680) was recorded; 5.5% in animals born after the 2006/07 RVF outbreak and 22.7% in animals present during the outbreak. There was a linear increase in prevalence in the post-epidemic annual cohorts. Nine inhibition-ELISA positive samples were also positive for RVFV IgM antibodies indicating a recent infection. The spatial distribution of seroprevalence exhibited a few hotspots. The sex difference in seroprevalence in animals born after the previous epidemic was not significant (6.1% vs. 4.6% for females and males respectively, p = 0.158) whereas it was significant in animals present during the outbreak (26.0% vs. 7.8% for females and males respectively, p,0.001). Animals living .15 km from the flood plain were more likely to have antibodies than those living ,5 km (OR 1.92; 95% CI 1.04–3.56). Species, breed, herd composition, grazing practices and altitude were not associated with seropositivity. These findings indicate post-epidemic transmission of RVFV in the study area. The linear increase in seroprevalence in the post-epidemic annual cohorts implies a constant exposure and presence of active foci transmission preceding the survey

    [Book Review of] Life and Death Decision-Making, by Baruch Brody

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    Case Notes

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    VIRTUAL ROBOT LOCOMOTION ON VARIABLE TERRAIN WITH ADVERSARIAL REINFORCEMENT LEARNING

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    Reinforcement Learning (RL) is a machine learning technique where an agent learns to perform a complex action by going through a repeated process of trial and error to maximize a well-defined reward function. This form of learning has found applications in robot locomotion where it has been used to teach robots to traverse complex terrain. While RL algorithms may work well in training robot locomotion, they tend to not generalize well when the agent is brought into an environment that it has never encountered before. Possible solutions from the literature include training a destabilizing adversary alongside the locomotive learning agent. The destabilizing adversary aims to destabilize the agent by applying external forces to it, which may help the locomotive agent learn to deal with unexpected scenarios. For this project, we will train a robust, simulated quadruped robot to traverse a variable terrain. We compare and analyze Proximal Policy Optimization (PPO) with and without the use of an adversarial agent, and determine which use of PPO produces the best results
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