5,730 research outputs found

    Ceramic composition at Chalcolithic Shiqmim, northern Negev desert, Israel: investigating technology and provenance using thin section petrography, instrumental geochemistry and calcareous nannofossils

    Get PDF
    Technological innovations in ceramic production and other crafts are hallmarks of the Chalcolithic period (4500–3600 BCE) in the southern Levant, but details of manufacturing traditions have not been fully investigated using the range of analytical methods currently available. This paper presents results of a compositional study of 51 sherds of ceramic churns and other pottery types from the Chalcolithic site of Shiqmim in the northern Negev desert. By applying complementary thin section petrography, instrumental geochemistry and calcareous nannofossil analyses, connections between the raw materials, clay paste recipes and vessel forms of the selected ceramic samples are explored and documented. The study indicates that steps in ceramic manufacturing can be related to both technological choices and local geology. Detailed reporting of the resulting data facilitates future comparative ceramic compositional research that is needed as a basis for testable regional syntheses and to better resolve networks of trade/exchange and social group movement

    Selected results on Strong and Coulomb-induced correlations from the STAR experiment

    Full text link
    Using recent high-statistics STAR data from Au+Au and Cu+Cu collisions at full RHIC energy I discuss strong and Coulomb-induced final state interaction effects on identical (π−π\pi-\pi) and non-identical (π−Ξ\pi-\Xi) particle correlations. Analysis of π−Ξ\pi-\Xi correlations reveals the strong and Coulomb-induced FSI effects allowing for the first time to estimate space extension of π\pi and Ξ\Xi sources and average shift between them. Source imaging technique providing clean separation of these effects from effects due to the source function itself is applied to one-dimensional relative momentum correlation function of identical pions. For low momentum pions and/or non-central collisions large departure from a single-Gaussian shape is observed

    The Iron Age copper industrial complex: A preliminary study of the role of ground stone tools at Khirbat en-Nahas, Jordan

    Get PDF
    The first industrial revolution in the southern Levant crystallized during the Iron Age when copper production reached scales never before seen in this part of the Middle East. Ever since copper ore was first smelted during the Chalcolithic period, the Arabah valley, and its widespread distribution of copper mineralization, was the main source for copper ore in the region. The main ore deposits are located in Timna (Israel) in the southern part of the valley, and some 105 km to the north, in the Faynan region (Jordan). Faynan is the largest copper ore resource zone in the southern Levant. Excavations at the Iron Age Faynan site of Khirbat en-Nahas and the recent final publication of that project have revealed peaks in industrial-scale production during the 10th and 9th centuries BCE. However, the role of ground stone tools in the Iron Age copper industry in Faynan has not been systematically presented. This paper presents a preliminary study of the ground stone assemblage from one excavation season at Khirbat en-Nahas, thereby highlighting the great potential for ground stone tools research at the site. Using the chaîne opératoire method of technological study, this paper takes a quantitative approach to the typological, material, and spatial distribution of ground stone artefacts at Khirbat en-Nahas to understand their role in copper production. Ethnoarchaeological study of hereditary bronze casting workshops in southern India provides a compelling model of how ground stone tools played a critical role in one of the most important dimensions of metal production in all periods - recycling - in an Iron Age copper factory

    An integration of attachment theory and reinforcement sensitivity theory

    Get PDF
    This thesis examined how relationship experiences shape people\u27s sensitivity to detect threat and reward in romantic relationships and substance use scenarios. Findings indicated that anxious individuals experienced difficulty in distinguishing between threat and reward. In contrast, avoidant individuals were quick to detect threat either fleeing or confronting the problem aggressively

    Stellar Proper Motions in the Galactic Bulge from deep HST ACS/WFC Photometry

    Full text link
    We present stellar proper motions in the Galactic bulge from the Sagittarius Window Eclipsing Extrasolar Search (SWEEPS) project using ACS/WFC on HST. Proper motions are extracted for more than 180,000 objects, with >81,000 measured to accuracy better than 0.3 mas/yr in both coordinates. We report several results based on these measurements: 1. Kinematic separation of bulge from disk allows a sample of >15,000 bulge objects to be extracted based on >6-sigma detections of proper motion, with <0.2% contamination from the disk. This includes the first detection of a candidate bulge Blue Straggler population. 2. Armed with a photometric distance modulus on a star by star basis, and using the large number of stars with high-quality proper motion measurements to overcome intrinsic scatter, we dissect the kinematic properties of the bulge as a function of distance along the line of sight. This allows us to extract the stellar circular speed curve from proper motions alone, which we compare with the circular speed curve obtained from radial velocities. 3. We trace the variation of the {l,b} velocity ellipse as a function of depth. 4. Finally, we use the density-weighted {l,b} proper motion ellipse produced from the tracer stars to assess the kinematic membership of the sixteen transiting planet candidates discovered in the Sagittarius Window; the kinematic distribution of the planet candidates is consistent with that of the disk and bulge stellar populations.Comment: 71 pages, 30 figures, ApJ Accepte

    Molecular line mapping of the giant molecular cloud associated with RCW 106 - II. Column density and dynamical state of the clumps

    Full text link
    We present a fully sampled C^{18}O (1-0) map towards the southern giant molecular cloud (GMC) associated with the HII region RCW 106, and use it in combination with previous ^{13}CO (1-0) mapping to estimate the gas column density as a function of position and velocity. We find localized regions of significant ^{13}CO optical depth in the northern part of the cloud, with several of the high-opacity clouds in this region likely associated with a limb-brightened shell around the HII region G333.6-0.2. Optical depth corrections broaden the distribution of column densities in the cloud, yielding a log-normal distribution as predicted by simulations of turbulence. Decomposing the ^{13}CO and C^{18}O data cubes into clumps, we find relatively weak correlations between size and linewidth, and a more sensitive dependence of luminosity on size than would be predicted by a constant average column density. The clump mass spectrum has a slope near -1.7, consistent with previous studies. The most massive clumps appear to have gravitational binding energies well in excess of virial equilibrium; we discuss possible explanations, which include magnetic support and neglect of time-varying surface terms in the virial theorem. Unlike molecular clouds as a whole, the clumps within the RCW 106 GMC, while elongated, appear to show random orientations with respect to the Galactic plane.Comment: 17 pages, to appear in MNRA

    Effect of insulin on glucose metabolism in the dog after portacaval transposition

    Get PDF
    The effect of insulin on hepatic glucose metabolism was studied by a multiple-catheter technique in unanesthetized dogs with Eck fistula and with portacaval transposition. With the latter preparation, blood entering and leaving the liver was sampled from peripherally inserted catheters. In the unanesthetized Eck-fistula animals, insulin infusion produced a decrease in the hepatic glucose output. In the dogs with portacaval transposition, a constant infusion of insulin was given alternately by systemic and by intraportal routes. There was no significant difference between the effects of insulin administered by the two routes. During insulin infusion, glucose concentration differences across the liver were reduced, hepatic plasma flow was transiently elevated, and hepatic glucose output was decreased. After discontinuance of insulin, there was a transient rise of hepatic glucose output to above control values. </jats:p

    An Analysis of Private School Closings

    Get PDF
    We add to the small literature on private school supply by exploring exits of K-12 private schools. We find that the closure of private schools is not an infrequent event, and use national survey data from the National Center for Education Statistics to study closures of private schools. We assume that the probability of an exit is a function of excess supply of private schools over the demand, as well as the school's characteristics such as age, size, and religious affiliation. Our empirical results generally support the implications of the model. Working Paper 07-0

    Permeating the social justice ideals of equality and equity within the context of Early Years: challenges for leadership in multi-cultural and mono-cultural primary schools

    Get PDF
    The ideology and commitment of social justice principles is central to Early Years practice, however, the term social justice in education is complex and remains contested. This paper explores the ideology of social justice through links between equality and equity and how it is embedded within Early Years, and what remain the potential challenges for leadership. Interviews in English multi-cultural and mono-cultural primary schools were conducted. Findings showed that the ideology of social justice, equality and equity was interpreted differently. Multi-cultural schools appear to use a greater variety of activities to embed social justice principles that involved their diverse communities more to enrich the curriculum. In mono-cultural schools leadership had to be more creative in promoting equality and equity given the smaller proportion of their diverse pupil and staff population. Tentative conclusions suggest that the vision for permeating equality and equity in Early Years, at best, is at early stages

    Artery tertiary lymphoid organs control aorta immunity and protect against atherosclerosis via vascular smooth muscle cell lymphotoxin β receptors

    Get PDF
    Tertiary lymphoid organs (TLOs) emerge during nonresolving peripheral inflammation, but their impact on disease progression remains unknown. We have found in aged Apoe−/− mice that artery TLOs (ATLOs) controlled highly territorialized aorta T cell responses. ATLOs promoted T cell recruitment, primed CD4+ T cells, generated CD4+, CD8+, T regulatory (Treg) effector and central memory cells, converted naive CD4+ T cells into induced Treg cells, and presented antigen by an unusual set of dendritic cells and B cells. Meanwhile, vascular smooth muscle cell lymphotoxin β receptors (VSMC-LTβRs) protected against atherosclerosis by maintaining structure, cellularity, and size of ATLOs though VSMC-LTβRs did not affect secondary lymphoid organs: Atherosclerosis was markedly exacerbated in Apoe−/−Ltbr−/− and to a similar extent in aged Apoe−/−Ltbrfl/flTagln-cre mice. These data support the conclusion that the immune system employs ATLOs to organize aorta T cell homeostasis during aging and that VSMC-LTβRs participate in atherosclerosis protection via ATLOs
    • …
    corecore