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Fighting obesity by targeting factors regulating beige adipocytes.
Purpose of reviewThe current review provides an update on secreted factors and mechanisms that promote a thermogenic program in beige adipocytes, and their potential roles as therapeutic targets to fight obesity.Recent findingsWe outline recent studies revealing unrecognized mechanisms controlling beige adipocyte physiology, and summarize in particular those that underlie beige thermogenesis independently of classical uncoupling. We also update strategies aimed at fostering beige adipogenesis and white-to beige adipocyte conversion. Finally, we summarize newly identified endogenous secreted factors that promote the thermogenic activation of beige adipocytes and discuss their therapeutic potential.SummaryThe identification of novel endogenous factors that promote beiging and regulate beige adipocyte-specific physiological pathways opens up new avenues for therapeutic engineering targeting obesity and related metabolic disorders
On the effects of Cosmions upon the structure and evolution of very low mass stars
A number of recent studies have suggested that cosmions, or WIMPS, may play an important role in the energetics of the solar interior; in particular, it has been argued that these hypothetical particles may transport sufficient energy within the nuclear-burning solar core so as to depress the solar core temperature to the point of resolving the solar neutrino problem. Solutions to the solar neutrino problem have proven themselves to be quite nonunique, so that it is of some interest whether the cosmion solution can be tested in some independent manner. It is argued that if cosmions solve the solar neutrino problem, then they must also play an important role in the evolution of low mass main sequence stars; and, second, that if they do so, then a simple (long mean free path) model for the interaction of cosmions with baryons leads to changes in the structure of the nuclear-burning core which may be in principal observable. Such changes include suppression of a fully-convective core in very low mass main sequence stars; and a possible thermal runaway in the core of the nuclear burning region. Some of these changes may be directly observable, and hence may provide independent constraints on the properties of the cosmions required to solve the solar neutrino problem, perhaps even ruling them out
Loss of purity by wave packet scattering at low energies
We study the quantum entanglement produced by a head-on collision between two
gaussian wave packets in three-dimensional space. By deriving the two-particle
wave function modified by s-wave scattering amplitudes, we obtain an
approximate analytic expression of the purity of an individual particle. The
loss of purity provides an indicator of the degree of entanglement. In the case
the wave packets are narrow in momentum space, we show that the loss of purity
is solely controlled by the ratio of the scattering cross section to the
transverse area of the wave packets.Comment: 7 pages, 1 figur
S-wave quantum entanglement in a harmonic trap
We analyze the quantum entanglement between two interacting atoms trapped in
a spherical harmonic potential. At ultra-cold temperature, ground state
entanglement is generated by the dominated s-wave interaction. Based on a
regularized pseudo-potential Hamiltonian, we examine the quantum entanglement
by performing the Schmidt decomposition of low-energy eigenfunctions. We
indicate how the atoms are paired and quantify the entanglement as a function
of a modified s-wave scattering length inside the trap.Comment: 10 pages, 5 figures, to be apear in PR
Incidence of advanced cutaneous malignant melanoma in the UK: a systematic review
Objectives: Cutaneous melanoma (CM) is one of the most aggressive forms of skin cancer. In 2008, CM was found to be the sixth most common cancer in the UK. The aim of this review was to systematically identify patients with advanced CM, limited to stage IIIc and stage IV disease.
Methods: Literature searches were undertaken in the Cochrane Library, MEDLINE, CINAHL and EMBASE between December 2010 and March 2011. Webpages of the Office of National Statistics, Cancer Research UK and the Welsh Cancer Intelligence and Surveillance Unit were also scanned. A narrative synthesis was undertaken due to the heterogeneity of included studies.
Results: Three observational studies were identified. One study was in East Anglia, England while the remaining two were in Scotland. Both studies in Scotland estimated that 2% of all melanoma patients had advanced CM at the time of diagnosis. It was also noted that, in East Anglia, the incidence of stage IV CM decreased from 0.42 to 0.13 per 100,000 population per year between 1991 and 2004. The review highlighted the challenges in identifying patients with advanced CM from available data.
Conclusions: This review highlighted the lack of, and the need for primary studies to estimate the incidence of advanced CM in the UK. Defining this subgroup of patients is important for identifying patients for targeted treatment. We suggest that researchers must clearly define this population of patients in future studies
A Chandra observation of GRO J1744-28: the bursting pulsar in quiescence
We present a Chandra/ACIS-I observation of GRO J1744-28. We detected a source
at a position of R.A = 17h 44m 33.09s and Dec. = -28degr 44' 27.0'' (J2000.0;
with a 1sigma error of ~0.8 arcseconds), consistent with both ROSAT and
interplanetary network localizations of GRO J1744-28 when it was in outburst.
This makes it likely that we have detected the quiescent X-ray counterpart of
GRO J1744-28. Our Chandra position demonstrates that the previously proposed
infrared counterpart is not related to GRO J1744-28. The 0.5-10 keV luminosity
of the source is 2 - 4 x 10^{33} erg/s (assuming the source is near the
Galactic center at a distance of 8 kpc). We discuss our results in the context
of the quiescent X-ray emission of pulsating and non-pulsating neutron star
X-ray transients.Comment: Accepted for publication in ApJ Letters, 20 February 200
Uncorrelated Measurements of the Cosmic Expansion History and Dark Energy from Supernovae
We present a method for measuring the cosmic expansion history H(z) in
uncorrelated redshift bins, and apply it to current and simulated type Ia
supernova data assuming spatial flatness. If the matter density parameter
Omega_m can be accurately measured from other data, then the dark energy
density history X(z)=rho_X(z)/rho_X(0) can trivially be derived from this
expansion history H(z). In contrast to customary ``black box'' parameter
fitting, our method is transparent and easy to interpret: the measurement of
H(z)^{-1} in a redshift bin is simply a linear combination of the measured
comoving distances for supernovae in that bin, making it obvious how systematic
errors propagate from input to output.
We find the Riess et al. (2004) ``gold'' sample to be consistent with the
``vanilla'' concordance model where the dark energy is a cosmological constant.
We compare two mission concepts for the NASA/DOE Joint Dark Energy Mission
(JDEM), the Joint Efficient Dark-energy Investigation (JEDI), and the Supernova
Accelaration Probe (SNAP), using simulated data including the effect of weak
lensing (based on numerical simulations) and a systematic bias from
K-corrections. Estimating H(z) in seven uncorrelated redshift bins, we find
that both provide dramatic improvements over current data: JEDI can measure
H(z) to about 10% accuracy and SNAP to 30-40% accuracy.Comment: 7 pages, 4 color figures. Expanded and revised version; PRD in pres
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