919 research outputs found
When research setting is important: the influence of subordinate self-esteem on reactions to abusive supervision
In this paper, we argue that the conflicting theoretical views regarding the role that self-esteem plays in the decision to become aggressive can be explained by the particular research methodology used. Specifically, we examine how individuals respond to a perceived abusive supervisor in two settings: (1) using scenarios and (2) in a field study. Results indicate that individuals with high selfesteem are more likely to become aggressive in response to an abusive supervisor in settings where they are asked what they would do (using scenarios). However, in field research settings, where they are asked what they did do, individuals with low self-esteem were more likely to become aggressive in response to an abusive supervisor
Effects of Management Support, Team Member Support, and Job Status on Safety Climate and Employee Attitudes
This study examined the impact of management and team member support on employee attitudes through the mediating effect of safety climate. Five hundred fifty-six physicians and nurses from a large teaching hospital in the eastern United States completed survey items assessing their perceptions of management support, team member support, and safety climate as well as job satisfaction and organizational commitment. Results indicated that while job satisfaction and commitment were directly affected by perceptions of management and team member support, these relationships were also partially mediated by safety climate. In addition, the results suggested that team member support contributed to the prediction of safety climate over and above the effect of management support alone indicating that multiple sources of support may be important in developing positive safety climates. The hypothesized moderating effect of job status was not significant. Implications of the results and suggestions for future research are discussed
Big-Bang Nucleosynthesis and the Baryon Density of the Universe
Big-bang nucleosynthesis is one of the cornerstones of the standard
cosmology. For almost thirty years its predictions have been used to test the
big-bang model to within a fraction of a second of the bang. The concordance
that exists between the predicted and observed abundances of D, He, He
and Li provides important confirmation of the standard cosmology and leads
to the most accurate determination of the baryon density, between 1.7 \times
10^{-31}\gcmm3 and 4.1\times 10^{-31}\gcmm3 (corresponding to between about
1\% and 14\% of critical density). This measurement of the density of ordinary
matter is crucial to almost every aspect of cosmology and is pivotal to the
establishment of two dark-matter problems: (i) most of the baryons are dark,
and (ii) if the total mass density is greater than about 14\% of the critical
density as many determinations now indicate, the bulk of the dark matter must
be ``nonbaryonic,'' comprised of elementary particles left from the earliest
moments. We critically review the present status of primordial nucleosynthesis
and discuss future prospects.Comment: 21 pages+6 figs, LaTeX(2.09), FERMILAB-Pub-94/174-A, Figures
available by anonymous ftp in oddjob.uchicago.edu:/pub/bbnrev/fig?.ps
(?=1,2,3,4,5,6) or email from [email protected] REVISIONS include new
discussion and a new figur
Reconciling Present Neutrino Puzzles: Sterile Neutrinos as Mirror Neutrinos
We suggest that recent neutrino puzzles that are the solar and atmospheric
neutrino deficits as well as the possible neutrino oscillations reported by the
LSND experiment and the possibility of massive neutrinos providing the hot
component of the cosmological dark matter, can all be naturally explained by
assuming existence of a mirror world described by an ``electroweak'' gauge
symmetry , with the breaking scale larger by about factor
of 30 than the scale of the standard model. An interesting
aspect of this model is that the sterile neutrinos arise from the hidden mirror
sector of the theory and thus their lightness is more natural than in the usual
neutrino mass scenarios. The needed pattern of the neutrino mass matrix in this
model is obtained by assuming a conserved ZKM-type global lepton number , which is violated by Planck scale effects. One implication
of our proposal is that bulk of the dark matter in the universe is a warm dark
matter consisting of few KeV mass particles rather than the 100 GeV range
particles of the currently popular cold dark matter scenarios.Comment: 10 pages, Latex, no figure
Spin-Flavour Oscillations and Neutrinos from SN1987A
The neutrino signal from SN1987A is analysed with respect to spin-flavour
oscillations between electron antineutrinos, , and muon
neutrinos, , by means of a maximum likelihood analysis.
Following Jegerlehner et al. best fit values for the total energy released in
neutrinos, , and the temperature of the electron antineutrino,
, for a range of mixing parameters and progenitor models are
calculated. In particular the dependence of the inferred quantities on the
metallicity of the supernova is investigated and the uncertainties involved in
using the neutrino signal to determine the neutrino magnetic moment are pointed
out.Comment: 14 pages, RevTeX, 4 figures, to appear in Physical Review
The Insulin Resistance Intervention after Stroke trial: a perspective on future practice and research
The prevention of recurrent events after ischaemic stroke and transient ischaemic attack is well established and based on lifestyle changes, antithrombotics, statins, antihypertensives and carotid surgery. The international IRIS trial assessed whether pioglitazone, a glucose-lowering insulin-sensitizing drug, would reduce recurrent vascular events in patients with ischaemic stroke or transient ischaemic attack. After 4.8 years, pioglitazone therapy was associated with reduced vascular events and new diabetes, and an increase in weight, oedema and bone fractures. Pioglitazone may add to the strategies for preventing further events in patients with stroke or transient ischaemic attack
Neutrino propagation in a random magnetic field
The active-sterile neutrino conversion probability is calculated for neutrino
propagating in a medium in the presence of random magnetic field fluctuations.
Necessary condition for the probability to be positive definite is obtained.
Using this necessary condition we put constraint on the neutrino magnetic
moment from active-sterile electron neutrino conversion in the early universe
hot plasma and in supernova.Comment: 11 page
Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions to Neutrino Anomalies
We propose a four-neutrino model which can reconcile the existing data coming
from underground experiments in terms of neutrino oscillations, together with
the hint from the LSND experiment and a possible neutrino contribution to the
hot dark matter of the Universe. It applies the idea that extra compact
dimensions, probed only by gravity and possibly gauge-singlet fields, can lower
the fundamental scales such as the Planck, string or unification scales. Our
fourth light neutrino ( for sterile) is identified with the zero
mode of the Kaluza-Klein states. To first approximation \nu_sterile combines
with the nu_mu in order to form a Dirac neutrino with mass in the eV range
leaving the other two neutrinos massless. The smallness of this mass scale
(suitable for LSND and Hot Dark Matter) arises without appealing neither to a
see-saw mechanism nor to a radiative mechanism, but from the volume factor
associated with the canonical normalization of the wave-function of the bulk
field in the compactified dimensions. % On the other hand the splitting between
\nm and \nu_sterile (atmospheric scale) as well as the mass of the two other
neutrinos (solar mass scale) arise from the violation of the fermion number on
distant branes. We also discuss alternative scenarios involving
flavour-changing interactions. In one of them \ne can be in the electron-volt
range and therefore be probed in beta decay studies.Comment: 12 pages, latex, no figures, title changed, final version to be
published in Phys Rev
Limits on Active-Sterile Neutrino Mixing and the Primordial Deuterium Abundance
Studies of limits on active-sterile neutrino mixing derived from big bang
nucleosynthesis considerations are extended to consider the dependance of these
constraints on the primordial deuterium abundance. This study is motivated by
recent measurements of D/H in quasar absorption systems, which at present yield
discordant results. Limits on active-sterile mixing are somewhat relaxed for
high D/H. For low D/H (), no active-sterile neutrino
mixing is allowed by currently popular upper limits on the primordial He
abundance . For such low primordial D/H values, the observational inference
of active-sterile neutrino mixing by upcoming solar neutrino experiments would
imply that has been systematically underestimated, unless there is new
physics not included in standard BBN.Comment: 10 pages + 2 figures, uses revtex macros, submitted to Phys. Rev. D.
Corrected figure captions and an added referenc
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