185 research outputs found
Loosely bound hyperons in the SU(3) Skyrme model
Hyperon pairs bound in deuteron like states are obtained within the SU(3)
Skyrme model in agreement with general expectations from boson exchange models.
The central binding from the flavor symmetry breaking terms increases with the
strangeness contents of the interacting baryons whereas the kinetic non-linear
-model term fixes the spin and isospin of the bound pair. We give a
complete account of the interactions of octet baryons within the product
approximation to baryon number configurations.Comment: 35 pages REVTEX including 2 figs, with 3 further figs available on
request from [email protected] or from [email protected]
SI-94-TP3S2; STPHY-Th/94-
Unveiling faculty conceptions of academic risk taking:a phenomenographic study
Among recent developments in the field of higher education is the emergence of New Public Management and of what has been labelled as ‘risk university’. The aim of this paper is to redress the lack of discussion over the role that risk taking plays in academic practice by exploring what faculty understand academic risk taking to be and how they enact this understanding in their tasks. Drawing on a phenomenographic perspective and semi-structured interviews with 20 faculty members from a high-profile UK university, we find that academic risk taking is experienced in four qualitatively different ways. Our results suggest that although academics engage in relatively similar endeavours, they exhibit various approaches to these endeavours due to their different conceptions of what constitutes academic risk taking. These findings have implications for the literature on identity construction and the debate over how the greater accountability of academic activity is affectively experienced
Properties of vector mesons at finite temperature -effective lagrangian approach-
The properties of -mesons at finite temperature () are examined with
an effective chiral lagrangian in which vector and axial-vector mesons are
included as massive Yang-Mills fields of the chiral symmetry. It is shown that,
at order, the effective mass is not changed but only the mixing effect in
vector and axial-vector correlator appears.Comment: 13 pages (REVTeX), two figures
On different lagrangian formalisms for vector resonances within chiral perturbation theory
We study the relation of vector Proca field formalism and antisymmetric
tensor field formalism for spin-one resonances in the context of the large N_C
inspired chiral resonance Lagrangian systematically up to the order O(p6) and
give a transparent prescription for the transition from vector to antisymmetric
tensor Lagrangian and vice versa. We also discuss the possibility to describe
the spin-one resonances using an alternative "mixed" first order formalism,
which includes both types of fields simultaneously, and compare this one with
the former two. We also briefly comment on the compatibility of the above
lagrangian formalisms with the high-energy constraints for concrete VVP
correlator.Comment: 34 pages, 3 figure
Presence of exon 5-deleted oestrogen receptor in human breast cancer: functional analysis and clinical significance.
A variant form of the human oestrogen receptor (ER) mRNA lacking sequences encoded within exon 5 has been described (Fuqua SAW, Fitzgerald SD, Chamness GC, Tandon AK, McDonnell DP, Nawaz Z, O'Malloy BW, McGuire WL 1991, Cancer Res 51: 105-109). We have examined the expression of the exon 5-deleted ER (HE delta5) mRNA variant in breast biopsies using reverse transcriptase polymerase chain reaction (RT - PCR). HE delta5 mRNA was present in only 13% of non-malignant breast tissues compared with 32% of carcinomas (95% CI, P=0.05). Presence of the HE delta5 mRNA was associated with the presence of immunohistochemically detected ER (P=0.015) and progesterone receptor (PR) (P=0.02). There was a positive correlation between the presence of HE delta5 and disease-free survival (P=0.05), suggesting that the presence of HE delta5 may be an indicator of better prognosis. We have raised a monoclonal antibody specific to the C-terminal amino acids of HE delta5. This antibody recognized the variant but not the wild-type ER protein. We show that HE delta5 protein is present in breast cancer using immunohistochemical techniques. We also analysed trans-activation by HE delta5 in mammalian cells and showed that, in MCF-7 cells, HE delta5 competes with wild-type ER to inhibit ERE-dependent trans-activation. Our results indicate that this variant is unlikely to be responsible for endocrine resistance of breast cancer, but its presence at both the mRNA and protein level suggest that it may, nevertheless, be involved in regulating the expression of oestrogen-responsive genes in breast cancer
Off-shell effects in dilepton production from hot interacting mesons
The production of dielectrons in reactions involving a_1 mesons and pions is
studied. We compare results obtained with different phenomenological
Lagrangians that have been used in connection with hadronic matter and finite
nuclei. We insist on the necessity for those interactions to satisfy known
empirical properties of the strong interaction. Large off-shell effects in
dielectron production are found and some consequences for the interpretation of
heavy ion data are outlined. We also compare with results obtained using
experimentally-extracted spectral functions.Comment: 14 pages, LaTeX2e, 2 figure
Chiral Fluid Dynamics and Collapse of Vacuum Bubbles
We study the expansion dynamics of a quark-antiquark plasma droplet from an
initial state with restored chiral symmetry. The calculations are made within
the linear model scaled with an additional scalar field representing
the gluon condensate. We solve numerically the classical equations of motion
for the meson fields coupled to the fluid-dynamical equations for the plasma.
Strong space-time oscillations of the meson fields are observed in the course
of the chiral transition. A new phenomenon, the formation and collapse of
vacuum bubbles, is also predicted. The particle production due to the
bremsstrahlung of the meson fields is estimated.Comment: 12 pages Revtex,5 figures, Figures modified, minor changes in text.
To be published in Phys. Rev. Let
Between overt and covert research: concealment and disclosure in an ethnographic study of commercial hospitality
This article examines the ways in which problems of concealment emerged in an ethnographic study of a suburban bar and considers how disclosure of the research aims, the recruitment of informants, and elicitation of information was negotiated throughout the fieldwork. The case study demonstrates how the social context and the relationships with specific informants determined overtness or covertness in the research. It is argued that the existing literature on covert research and covert methods provides an inappropriate frame of reference with which to understand concealment in fieldwork. The article illustrates why concealment is sometimes necessary, and often unavoidable, and concludes that the criticisms leveled against covert methods should not stop the fieldworker from engaging in research that involves covertness
The Hidden Curriculum of Veterinary Education: Mediators and Moderators of Its Effects
The “hidden curriculum” has long been supposed to have an effect on students' learning during their clinical education, and in particular in shaping their ideas of what it means to be a professional. Despite this, there has been little evidence linking specific changes in professional attitudes to the individual components of the hidden curriculum. This study aimed to recognize those components that led to a change in students' professional attitudes at a UK veterinary school, as well as to identify the attitudes most affected. Observations were made of 11 student groups across five clinical rotations, followed by semi-structured interviews with 23 students at the end of their rotation experience. Data were combined and analyzed thematically, taking both an inductive and deductive approach. Views about the importance of technical competence and communication skills were promoted as a result of students' interaction with the hidden curriculum, and tensions were revealed in relation to their attitudes toward compassion and empathy, autonomy and responsibility, and lifestyle ethic. The assessment processes of rotations and the clinical service organization served to communicate the messages of the hidden curriculum, bringing about changes in student professional attitudes, while student-selected role models and the student rotation groups moderated the effects of these influences
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