4,473 research outputs found
A long hard look at MCG-6-30-15 with XMM-Newton and BeppoSAX
We summarise the primary results from a 320 ks observation of the bright
Seyfert 1 galaxy MCG-6-30-15 with XMM-Newton and Beppo-SAX.Comment: 4 pages, 6 figures. Proc. of the meeting: "The Restless High-Energy
Universe" (Amsterdam, The Netherlands), E.P.J. van den Heuvel, J.J.M. in 't
Zand, and R.A.M.J. Wijers Ed
Role of interference in MM-wave driven DC transport in two dimensional electron gas
In this paper we point out that in addition to the density of states effect
proposed in Ref.\cite{durst,anderson} one should consider the effect of
constructive interference between the multi-MM-wave-photon processes shown in
Fig.2. This process enhances the dark value of the conductivity. When the
sample is very pure, i.e., when the transport life time is very long, this
interference effect quickly diminishes as the MM-wave frequency deviates from
the cyclotron frequency. In this paper we also present the linear response
theory in the presence of strong harmonic time-dependent perturbation
Prevalence of musculoskeletal injuries among young squash players in Malaysia
The aim of the study was to investigate the prevalence of musculoskeletal injuries sustained by young squash players in Malaysia. This study was conducted retrospectively by usingStandardized Nordic Questionnaire (NSQ) during SUKMA 2016 at Kuching, Sarawak, Malaysia. The questionnaires were distributed to the squash players after getting the approval from the authorities. Totally 94 questionnaires were distributed and 60 questionnaires (62.5%) were returned with completed answers. The mean age of the respondents were 17.58 ± 3.042 years with 8.85 ± 3.013 years of experience of playing squash. Among the respondents 83.33% were reported that they had musculoskeletal problems during last 12 months. The wrist and hand were the area with the highest (31.7%) prevalence of musculoskeletal symptoms, and the elbow with least (8.3%) prevalence among the respondents.Key Words: Squash, musculoskeletal, injury, survey, evaluatio
Atomic X-ray Spectroscopy of Accreting Black Holes
Current astrophysical research suggests that the most persistently luminous
objects in the Universe are powered by the flow of matter through accretion
disks onto black holes. Accretion disk systems are observed to emit copious
radiation across the electromagnetic spectrum, each energy band providing
access to rather distinct regimes of physical conditions and geometric scale.
X-ray emission probes the innermost regions of the accretion disk, where
relativistic effects prevail. While this has been known for decades, it also
has been acknowledged that inferring physical conditions in the relativistic
regime from the behavior of the X-ray continuum is problematic and not
satisfactorily constraining. With the discovery in the 1990s of iron X-ray
lines bearing signatures of relativistic distortion came the hope that such
emission would more firmly constrain models of disk accretion near black holes,
as well as provide observational criteria by which to test general relativity
in the strong field limit. Here we provide an introduction to this phenomenon.
While the presentation is intended to be primarily tutorial in nature, we aim
also to acquaint the reader with trends in current research. To achieve these
ends, we present the basic applications of general relativity that pertain to
X-ray spectroscopic observations of black hole accretion disk systems, focusing
on the Schwarzschild and Kerr solutions to the Einstein field equations. To
this we add treatments of the fundamental concepts associated with the
theoretical and modeling aspects of accretion disks, as well as relevant topics
from observational and theoretical X-ray spectroscopy.Comment: 63 pages, 21 figures, Einstein Centennial Review Article, Canadian
Journal of Physics, in pres
Pareto's Law of Income Distribution: Evidence for Germany, the United Kingdom, and the United States
We analyze three sets of income data: the US Panel Study of Income Dynamics
PSID), the British Household Panel Survey (BHPS), and the German Socio-Economic
Panel (GSOEP). It is shown that the empirical income distribution is consistent
with a two-parameter lognormal function for the low-middle income group
(97%-99% of the population), and with a Pareto or power law function for the
high income group (1%-3% of the population). This mixture of two qualitatively
different analytical distributions seems stable over the years covered by our
data sets, although their parameters significantly change in time. It is also
found that the probability density of income growth rates almost has the form
of an exponential function.Comment: Latex2e v1.6; 16 pages with 5 figure
Two different quasiparticle scattering rates in vortex line liquid phase of layered d-wave superconductors
We carry out a quantum mechanical analysis of the behavior of nodal
quasiparticles in the vortex line liquid phase of planar d-wave
superconductors. Applying a novel path integral technique we calculate a number
of experimentally relevant observables and demonstrate that in the low-field
regime the quasiparticle scattering rates deduced from photoemission and
thermal transport data can be markedly different from that extracted from
tunneling, specific heat, superfluid stiffness or spin-lattice relaxation time.Comment: Latex, 4 pages, no figure
Magnetic monopoles from gauge theory phase transitions
Thermal fluctuations of the gauge field lead to monopole formation at the
grand unified phase transition in the early Universe, even if the transition is
merely a smooth crossover. The dependence of the produced monopole density on
various parameters is qualitatively different from theories with global
symmetries, and the monopoles have a positive correlation at short distances.
The number density of monopoles may be suppressed if the grand unified symmetry
is only restored for a short time by, for instance, nonthermal symmetry
restoration after preheating.Comment: 5 pages, updated to match the version published in PRD
(http://link.aps.org/abstract/PRD/v68/e021301) on 11 July 200
Spontaneous breaking of superconformal invariance in (2+1)D supersymmetric Chern-Simons-matter theories in the large N limit
In this work it is studied the spontaneous breaking of superconformal and
gauge invariances in the Abelian N=1,2 three-dimensional supersymmetric
Chern-Simons-matter theories in a large N limit. It is computed the K\"ahlerian
effective superpotential at subleading order and shown that the
Coleman-Weinberg mechanism is the responsible for the dynamical generation of a
mass scale in the N=1 model. This effect appears due to two-loop diagrams that
are logarithmic divergent. In particular, the Coleman-Weinberg mechanism fails
when we lift the N=1 to N=2 Supersymmetric Chern-Simons-Matter model, like what
happens in a perturbative expansion in the coupling constants.Comment: 10 pages, 2 figures, PLB versio
Enzymatic hydrolysate from velvet antler suppresses adipogenesis in 3T3-L1 cells and attenuates obesity in high-fat diet-fed mice
The purpose of the current study was to investigate the potential anti-obesity activity of an enzymatic hydrolysate of velvet antler in inhibiting adipogenesis in 3T3-L1 cells and in high-fat diet (HFD)-fed obese mice. The enzy- matic hydrolysate was prepared using the commercial food grade protease, Protamex. The velvet antler Protamex hydrolysate (VAPH) indicated profound inhibitory effects on adipogenesis dose-dependently by decreasing the accumulation of triglycerides and down-regulating expression levels of adipogenesis-related proteins C/EBPα, SREBP-1, and PPARγ. In a mouse model of HFD-induced obesity, oral administration of VAPH (100 and 300 mg/kg for 13 weeks) significantly reduced the body weight gain that had resulted from the HFD. VAPH treat- ment also lowered the serum glucose and triglyceride levels, while increasing the HDL-C level. Furthermore, the treatment greatly reduced hepatic lipid droplet accumulation as well as the size of adipocytes. Current findings H has profound anti-obesity effects and could be an effective candidate for preventing obesity and obesity-related chronic diseases
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