20,685 research outputs found

    The Politics of Somali Bantu Identity in the United States

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    Tax Theory & Feral AI

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    This essay is a sci-fi thought experiment about the significance of personhood in income taxation, meant to explore the validity of currently prevailing justifications for the tax

    Stronger Partnerships for Safer Food: An Agenda for Strengthening State and Local Roles in the Nation's Food Safety System

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    Examines federal, state, and local agencies' responsibilities, strengths, and weaknesses in ensuring food safety. Recommends systemwide reforms to enhance state and local roles and improve surveillance, outbreak response, and regulation and inspection

    Opiate Drug Seeking and Addiction: The Influence of Sucrose Consumption on the Acquisition and Expression of Morphine-induced Conditioned Place Preferences (CPP)

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    Sucrose intake may lead to changes in brain and behavior similar to the effects of abused drugs. For example, sucrose may agonize endogenous opiate systems and modulate opiate-seeking behavior. Previous research reported equivocal outcomes where sucrose may either enhance (i.e., cross-sensitization) or attenuate (i.e., cross-tolerance) drug seeking as measured by morphine-induced CPP. The present experiment extends from past work and evaluated the impact of sucrose administered prior to place conditioning. Additionally, unique groups received sucrose prior to tests for CPP to measure sucrose influences on CPP expression. Sprague-Dawley rats (n=24) were assigned to sucrose (15% w/v) or water pre-exposure conditions. Subsequently, subjects received morphine place conditioning where morphine (10mg/kg) was administered on the initially non-preferred side of the apparatus. Three post-tests were conducted and, prior to each test, animals within each pre-exposure group (sucrose or water) received either sucrose or water. Factorial ANOVA was used to analyze data. Results showed robust morphine-induced CPP. Although animals in the sucrose pre-exposure condition displayed enhanced CPP, the outcomes were not statistically significant. The present findings support the value of CPP techniques to measure opiate drug-seeking behavior. Future work may discover the sufficient conditions for detecting sucrose cross-sensitization of morphine CPP

    A Prehispanic Maya Pit Oven? Microanalysis of Fired Clay Balls from the Puuc Region, Yucatán, Mexico

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    This is a postprint (author's final draft) version of an article published in Journal of Archaeological Science in 2013. The final version of this article may be found at http://dx.doi.org/10.1016/j.jas.2012.10.014 (login may be required). The version made available in OpenBU was supplied by the author.Excavations of a kitchen at Escalera al Cielo in the Puuc Maya region of Yucatán, Mexico uncovered a concentration of fired clay balls (ca. 3–5 cm in diameter), in addition to other de facto domestic refuse. The kitchen pertains to an intensively excavated elite residential group that was rapidly abandoned sometime near the end of the Terminal Classic period (A.D. 800–950), resulting in floor assemblages that provide an opportunity to explore the types and distribution of daily household activities. The results of experimental replications and a suite of analyses comprising modal analysis, ceramic petrography, Fourier transform infrared spectroscopy (FTIR), and microbotanical residue analysis reveal aspects of clay preparation, firing temperatures, repeated use of the balls, firing conditions, and specific plant food or fuel residues adhering to them. We show that the fired clay balls were manufactured with local, clay-rich soil and employed by the inhabitants of Escalera al Cielo as heating elements; relatively high concentrations of microbotanical residues from edible plants adhering to them support the hypothesis that they were involved in kitchen activities related to food processing

    Star formation and accretion in the circumnuclear disks of active galaxies

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    We explore the evolution of supermassive black holes (SMBH) centered in a circumnuclear disk (CND) as a function of the mass supply from the host galaxy and considering different star formation laws, which may give rise to a self-regulation via the injection of supernova-driven turbulence. A system of equations describing star formation, black hole accretion and angular momentum transport was solved for an axisymmetric disk in which the gravitational potential includes contributions from the black hole, the disk and the hosting galaxy. Our model extends the framework provided by Kawakatu et al. (2008) by separately considering the inner and outer part of the disk, and by introducing a potentially non-linear dependence of the star formation rate on the gas surface density and the turbulent velocity. The star formation recipes are calibrated using observational data for NGC 1097, while the accretion model is based on turbulent viscosity as a source of angular momentum transport in a thin viscous accretion disk. We find that current data provide no strong constraint on the star formation recipe, and can in particular not distinguish between models entirely regulated by the surface density, and models including a dependence on the turbulent velocity. The evolution of the black hole mass, on the other hand, strongly depends on the applied star formation law, as well as the mass supply from the host galaxy. We suggest to explore the star formation process in local AGN with high-resolution ALMA observations to break the degeneracy between different star formation models.Comment: 13 pages, 15 figures, 6 tables, accepted at A&
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