6,466 research outputs found
Meaningful work and secondary school teachers’ intention to leave
The study investigates the relations between secondary school teachers’ work-role fit, job enrichment, supervisor relationships, co-worker relationships, psychological meaningfulness of work and intention to leave. A cross-sectional survey was used. The participants were 502 secondary school teachers in Namibia. The following measuring instruments were used: Work-role Fit Scale, Job Enrichment Scale, Co-worker and Supervisor Relationships Scales, Psychological Meaningfulness Scale and Turnover Intention Scale. Work-role fit and job enrichment both had direct positive effect on experiences of psychological meaningfulness at work, while poor work-role fit and low psychological meaningfulness both had a direct effect on teachers’ intentions to leave. An analysis of the indirect effects showed that poor work-role fit and poor job enrichment affected intention to leave due to the concomitant experience of low psychological meaningfulness. These findings have implications for the retention of teachers in secondary schools.Keywords: co-worker relationships; intention to leave; job crafting; job enrichment; Namibia; psychological meaningfulness; secondary schools; supervisor relationships; turnover; work-role fi
Effective Low Energy Theories and QCD Dirac Spectra
We analyze the smallest Dirac eigenvalues by formulating an effective theory
for the QCD Dirac spectrum. We find that in a domain where the kinetic term of
the effective theory can be ignored, the Dirac eigenvalues are distributed
according to a Random Matrix Theory with the global symmetries of the QCD
partition function. The kinetic term provides information on the slope of the
average spectral density of the Dirac operator. In the second half of this
lecture we interpret quenched QCD Dirac spectra at nonzero chemical potential
(with eigenvalues scattered in the complex plane) in terms of an effective low
energy theory.Comment: Invited talk at the 10th International Conference on Recent Progress
in Many-Body Theories (MBX), Seattle, September 1999, 13 pages, Latex, with 1
figure, uses ws-p9-75x6-50.cl
The characteristics of thermalization of boost-invariant plasma from holography
We report on the approach towards the hydrodynamic regime of boost-invariant
N=4 super Yang-Mills plasma at strong coupling starting from various
far-from-equilibrium states at tau=0. The results are obtained through
numerical solution of Einstein's equations for the dual geometries, as
described in detail in the companion article arXiv:1203.0755. Despite the very
rich far-from-equilibrium evolution, we find surprising regularities in the
form of clear correlations between initial entropy and total produced entropy,
as well as between initial entropy and the temperature at thermalization,
understood as the transition to a hydrodynamic description. For 29 different
initial conditions that we consider, hydrodynamics turns out to be definitely
applicable for proper times larger than 0.7 in units of inverse temperature at
thermalization. We observe a sizable anisotropy in the energy-momentum tensor
at thermalization, which is nevertheless entirely due to hydrodynamic effects.
This suggests that effective thermalization in heavy ion collisions may occur
significantly earlier than true thermalization.Comment: 4 pages, 5 figures; see also the companion article arXiv:1203.0755;
v2: figure corrected (fixes problem with Acrobat); v3: various clarifications
and additional data points added; v4: typo fixed, publishe
Supergravitons from one loop perturbative N=4 SYM
We determine the partition function of 1/16 BPS operators in N=4 SYM at weak
coupling at the one-loop level in the planar limit. This partition function is
significantly different from the one computed at zero coupling. We find that it
coincides precisely with the partition function of a gas of 1/16 BPS
`supergravitons' in AdS_5xS^5.Comment: 22 pages; v2: references adde
The AdS_5xS^5 superstring worldsheet S-matrix and crossing symmetry
An S-matrix satisying the Yang-Baxter equation with symmetries relevant to
the AdS_5xS^5 superstring has recently been determined up to an unknown scalar
factor. Such scalar factors are typically fixed using crossing relations,
however due to the lack of conventional relativistic invariance, in this case
its determination remained an open problem.
In this paper we propose an algebraic way to implement crossing relations for
the AdS_5xS^5 superstring worldsheet S-matrix. We base our construction on a
Hopf-algebraic formulation of crossing in terms of the antipode and introduce
generalized rapidities living on the universal cover of the parameter space
which is constructed through an auxillary, coupling constant dependent,
elliptic curve. We determine the crossing transformation and write functional
equations for the scalar factor of the S-matrix in the generalized rapidity
plane.Comment: 27 pages, no figures; v2: sign typo fixed in (24), everything else
unchange
Flavors in an expanding plasma
We consider the effect of an expanding plasma on probe matter by determining
time-dependent D7 embeddings in the holographic dual of an expanding viscous
plasma. We calculate the chiral condensate and meson spectra including
contributions of viscosity. The chiral condensate essentially confirms the
expectation from the static black hole. For the meson spectra we propose a
scheme that is in agreement with the adiabatic approximation. New contributions
arise for the vector mesons at the order of the viscosity terms.Comment: 15 pages, 7 figures; v2: accepted for publ. in Phys. Rev. D; revised
mass definition agrees with adiabatic approximatio
Asymptotic perfect fluid dynamics as a consequence of AdS/CFT
We study the dynamics of strongly interacting gauge-theory matter (modelling
quark-gluon plasma) in a boost-invariant setting using the AdS/CFT
correspondence. Using Fefferman-Graham coordinates and with the help of
holographic renormalization, we show that perfect fluid hydrodynamics emerges
at large times as the unique nonsingular asymptotic solution of the nonlinear
Einstein equations in the bulk. The gravity dual can be interpreted as a black
hole moving off in the fifth dimension. Asymptotic solutions different from
perfect fluid behaviour can be ruled out by the appearance of curvature
singularities in the dual bulk geometry. Subasymptotic deviations from perfect
fluid behaviour remain possible within the same framework.Comment: 19 pages, 1 figure; v2: free streaming example changed to s=1;
conclusions unchange
Chasing consistency: an update of the TCP gene family of Malus Ă— domestica
The 52 members of the Teosinte-Branched 1/Cycloidea/Proliferating Cell Factors (TCP) Transcription Factor gene family in Malus Ă— domestica (M. Ă— domestica) were identified in 2014 on the first genome assembly, which was released in 2010. In 2017, a higher quality genome assembly for apple was released and is now considered to be the reference genome. Moreover, as in several other species, the identified TCP genes were named based on the relative position of the genes on the chromosomes. The present work consists of an update of the TCP gene family based on the latest genome assembly of M. Ă— domestica. Compared to the previous classification, the number of TCP genes decreased from 52 to 40 as a result of the addition of three sequences and the deduction of 15. An analysis of the intragenic identity led to the identification of 15 pairs of orthologs, shedding light on the forces that shaped the evolution of this gene family. Furthermore, a revised nomenclature system is proposed that is based both on the intragenic identity and the homology with Arabidopsis thaliana (A. thaliana) TCPs in an effort to set a common standard for the TCP classification that will facilitate any future interspecific analysi
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