1,070 research outputs found

    A quark model framework for the study of nuclear medium effects

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    A quark-model framework for studying nuclear medium effects on nucleon resonances is described and applied here to pion photoproduction on the deuteron, which is the simplest composite nucleon system and serves as a first test case. Pion photoproduction on nuclei is discussed within a chiral constituent quark model in which the quark degrees of freedom are explicitly introduced through an effective chiral Lagrangian for the quark-pseudoscalar-meson coupling. The advantage of this model is that a complete set of nucleon resonances can be systematically included with a limited number of parameters. Also, the systematic description of the nucleon and its resonances at quark level allows us to self-consistently relate the nuclear medium's influence on the baryon properties to the intrinsic dynamic aspects of the baryons. As the simplest composite nucleus, the deuteron represents the first application of this effective theory for meson photoproduction on light nuclei. The influence of the medium on the transition operators for a free nucleon is investigated in the Delta resonance region. No evidence is found for a change of the Delta properties in the pion photoproduction reaction on the deuteron since the nuclear medium here involves just one other nucleon and the low binding energy implies low nuclear density. However, we show that the reaction mechanism is in principle sensitive to changes of Delta properties that would be produced by the denser nuclear medium of heavier nuclei through the modification of the quark model parameters.Comment: Revtex, 8 pages, 4 figure

    Effect of Boundary-Layer Bleed Hole Inclination Angle and Scaling on Flow Coefficient Behavior

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    Phase II data results of the Fundamental Inlet Bleed Experiments study at NASA Glenn Research Center are presented which include flow coefficient behavior for 21 bleed hole configurations. The bleed configurations are all round holes with hole diameters ranging from 0.795 to 6.35 mm, hole inclination angles from 20deg to 90deg, and thickness-to-diameter ratios from 0.25 to 2.0. All configurations were tested at a unit Reynolds number of 2.46 10(exp 7)/m and at discrete local Mach numbers of 1.33, 1.62, 1.98, 2.46, and 2.92. Interactions between the design parameters of hole diameter, hole inclination angle, and thickness-to-diameter as well as the interactions between the flow parameters of pressure ratio and Mach number upon the flow coefficient are examined, and a preliminary statistical model is proposed. An existing correlation is also examined with respect to this data

    Post-traumatic stress disorder following childbirth: an update of current issues and recommendations for future research

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    Objective: This paper aimed to report the current status of research in the field of post-traumatic stress disorder following childbirth (PTSD FC), and to update the findings of an earlier 2008 paper. Background: A group of international researchers, clinicians and service users met in 2006 to establish the state of clinical and academic knowledge relating to PTSD FC. A paper identified four key areas of research knowledge at that time. Methods: Fourteen clinicians and researchers met in Oxford, UK to update the previously published paper relating to PTSD FC. The first part of the meeting focused on updating the four key areas identified previously, and the second part on discussing new and emerging areas of research within the field. Results: A number of advances have been made in research within the area of PTSD FC. Prevalence is well established within mothers, several intervention studies have been published, and there is growing interest in new areas: staff and pathways; prevention and early intervention; impact on families and children; special populations; and post-traumatic growth. Conclusion: Despite progress, significant gaps remain within the PTSD FC knowledge base. Further research continues to be needed across all areas identified in 2006, and five areas were identified which can be seen as ‘new and emerging’. All of these new areas require further extensive research. Relatively little is still known about PTSD FC

    Chiral bosonization for non-commutative fields

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    A model of chiral bosons on a non-commutative field space is constructed and new generalized bosonization (fermionization) rules for these fields are given. The conformal structure of the theory is characterized by a level of the Kac-Moody algebra equal to (1+θ2)(1+ \theta^2) where θ\theta is the non-commutativity parameter and chiral bosons living in a non-commutative fields space are described by a rational conformal field theory with the central charge of the Virasoro algebra equal to 1. The non-commutative chiral bosons are shown to correspond to a free fermion moving with a speed equal to c=c1+θ2 c^{\prime} = c \sqrt{1+\theta^2} where cc is the speed of light. Lorentz invariance remains intact if cc is rescaled by ccc \to c^{\prime}. The dispersion relation for bosons and fermions, in this case, is given by ω=ck\omega = c^{\prime} | k|.Comment: 16 pages, JHEP style, version published in JHE

    From social rights to the market: neo-liberalism and the knowledge economy

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    Public higher education has a long history, with its growth associated with mass higher education and the extension of a social right to education from secondary schooling to university education. Following the rise in student numbers since the 1970s, the aspiration to higher education has been universalized, although opportunities remain structured by social background. This paper looks at changing policies for higher education in the UK and the emergence of a neoliberal knowledge regime. This subordinates higher education to the market and shifts the burden of paying for degree courses onto students. It seeks to stratify institutions and extend the role of for-profit providers. From a role in the amelioration of social inequality, universities are now asked to participate actively in the widening inequalities associated with a neoliberal global market order

    The sedimentation of an institution: changing governance in UK financial services

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    Post-print version. Final version published by Sage; available online at http://jmi.sagepub.com/The Financial Services Act (FSA) 1986 was the first comprehensive attempt to create a unified statutorily based system of regulation within the UK financial sector. It generated a framework of regulation that is in a continuous state of development and modification. In this paper we study the development of UK financial regulation between 1986 and 2011. We trace how competing theorizations and logics of regulation have led to the institutionalization of a meta-form of financial regulation. In doing so, we address the conundrum of conscious, strategic theorizations leading to cognitive taken-for-granted institutions by identifying four catalysts that contribute to institutionalization when concurring with theorization. These are: the evocation of political ideologies, the appropriation of scandals, the growing number of actors and the increasing organization of actors. Finally, we argue that sedimentation is the appropriate metaphor for the version of institutionalization occurring in this setting

    A Case Study of the Military Utility of Telemedicine

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    This paper is designed to relate the rationale used by the Department of Defense to determine the military utility of the Joint Medical Operations – Telemedicine Advanced Concept Technology Demonstration (JMO-T ACTD). The paper also develops Critical Operational Issues (COI) and Measures of Effectiveness (MOE) as methodologies for investigating the military utility of telemedicine. In order to meet increasing global crises, the U.S. military must find ways to more effectively manage manpower and time. Joint Medical Operations – Telemedicine (JMO-T) has been developed by the Department of Defense (DOD) to collect and transmit near-real-time, far-forward medical data and to assess how this improved capability enhances medical management of the battlespace. JMO-T has been successful in resolving uncertain organizational and technological military deficiencies and in improving medical communications and information management. The deployable, mobile Telemedicine Teams are the centerpieces of JMO-T. These teams have the capability of inserting essential networking and communications capabilities into austere theaters and establishing an immediate means for enhancing health protection, collaborative planning, situational awareness, and strategic decision-making
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