2,967 research outputs found
Jet substructure as a new Higgs search channel at the LHC
It is widely considered that, for Higgs boson searches at the Large Hadron
Collider, WH and ZH production where the Higgs boson decays to b anti-b are
poor search channels due to large backgrounds. We show that at high transverse
momenta, employing state-of-the-art jet reconstruction and decomposition
techniques, these processes can be recovered as promising search channels for
the standard model Higgs boson around 120 GeV in mass.Comment: 4 pages, 3 figure
Regulation of protein kinase B and glycogen synthase kinase-3 by insulin and beta-adrenergic agonists in rat epididymal fat cells - Activation of protein kinase B by wortmannin-sensitive and -insensittve mechanisms
Previous studies using L6 myotubes have suggested that glycogen synthase kinase-3 (GSK-3) is phosphoryl ated and inactivated in response to insulin by protein kinase B (PKB, also known as Akt or RAG) (Cross, D, A, E., Alessi, D, R., Cohen, P., Andjelkovic, M., and Hemmings, B, A. (1995) Nature 378, 785-789), In the present study, marked increases in the activity of PKB have been shown to occur in insulin-treated rat epididymal fat cells with a time course compatible with the observed decrease in GSK-3 activity, Isoproterenol, acting primarily through beta(3)-adrenoreceptors, was found to decrease GSK-3 activity to a similar extent (approximately 50%) to insulin, However, unlike the effect of insulin, the inhibition of GSK by isoproterenol was not found to be sensitive to inhibition by the phosphatidylinositol 3'-kinase inhibitors, wortmannin or LY 294002, The change in GSK-3 activity brought about by isoproterenol could not be mimicked by the addition of permeant cyclic AMP analogues or forskolin to the cells, although at the concentrations used, these agents were able to stimulate lipolysis. Isoproterenol, but again not the cyclic AMP analogues, was found to increase the activity of PKB, although to a lesser extent than insulin. While wortmannin abolished the stimulation of PKB activity by insulin, it was without effect on the activation seen in response to isoproterenol, The activation of PKB by isoproterenol was not accompanied by any detectable change in the electrophoretic mobility of the protein on SDS-polyacrylamide gel electrophoresis. It would therefore appear that distinct mechanisms exist for the stimulation of PKB by insulin and isoproterenol in rat fat cells
Who is in the transition gap? Transition from CAMHS to AMHS in the Republic of Ireland
Objective: The ITRACK study explored the process and predictors of transition between Child and Adolescent Mental Health Services (CAMHS) and Adult Mental Health Services (AMHS) in the Republic of Ireland. Method: Following ethical approval, clinicians in each of Ireland's four Health Service Executive (HSE) areas were contacted, informed about the study and invited to participate. Clinicians identified all cases who had reached the transition boundary (i.e. upper age limit for that CAMHS team ) between January and December 2010. Data were collected on clinical and socio-demographic details and factors that informed the decision to refer or not refer to AMHS and case notes were scrutinised to ascertain the extent of information exchanged between services during transition
The length of time's arrow
An unresolved problem in physics is how the thermodynamic arrow of time
arises from an underlying time reversible dynamics. We contribute to this issue
by developing a measure of time-symmetry breaking, and by using the work
fluctuation relations, we determine the time asymmetry of recent single
molecule RNA unfolding experiments. We define time asymmetry as the
Jensen-Shannon divergence between trajectory probability distributions of an
experiment and its time-reversed conjugate. Among other interesting properties,
the length of time's arrow bounds the average dissipation and determines the
difficulty of accurately estimating free energy differences in nonequilibrium
experiments
Medical Care Costs Associated with Postmenopausal Estrogen Plus Progestogen Therapy
OBJECTIVE: To investigate the medical management costs of estrogen plus progestogen hormone therapy (HT) among postmenopausal women taking HT primarily as a preventive treatment for osteoporosis. DESIGN: Retrospective longitudinal comparative analysis of HT users and demographically matched nonusers using administrative databases on physician services, hospital stays and prescription medications. SETTING: Saskatchewan, Canada. PATIENTS: a total of 5762 women aged 55 years or more who took HT sometime between 1990 and 1997 and 5762 demographically matched controls who did not take HT from 1990 to 1997. MAIN OUTCOME MEASURES: total medical care expenditures and apparent costs of managing adverse events associated with HT. RESULTS: Excluding drug acquisition costs for HT and costs of care for osteoporosis, women in their first year of postmenopausal HT had total medical care costs about 90 to 390 during the first year of therapy and 110 per annum after the first year of therapy. These excess costs primarily are the result of excess rates of resource utilization for uterine- and breast-related diagnostic and treatment procedures. CONCLUSION: Medical management costs for HT may be substantial during the first year of therapy, and some medical management costs may persist over several years. These short-term management costs, combined with recent data about the long-term safety of HT as a preventive therapy, reinforce the importance of considering therapeutic alternatives to HT
Classical pion fields in the presence of source
Classical pion field similar to Disoriented Chiral Condensate (DCC) is
considered in the presence of the external source. This field is similar to DCC
in the sense that its isotopic orientation is specified with a single vector at
the whole space. We study the classical field solutions in the nonlinear
sigma-model both in the chiral limit with massless pion and for the finite pion
mass. In both cases the field resembles the Coulomb field of charged particle
however the nonlinear pion interactions lead to the existence of several
solutions. In the massless case and for the very small size of the source there
is the lot of classical solutions with finite discrete energies. In the more
realistic situation of large nucleus (heavy ion) there are no stable solutions
of the above type, but there is the possibility for the formation of the
quasistationary states. They can live for a long time slowly decaying through
the emission of very soft pions. The structure and the energies of these
solutions is investigated numerically.Comment: 10 pages, LaTeX, 1 figure, epsfig.sty, corrected typos, added
reference
Is Anomalous Production of Omega and anti-Omega Evidence for Disoriented Chiral Condensates?
No conventional picture of nucleus-nucleus collisions has yet been able to
explain the abundance of Omega and anti-Omega hyperons in central collisions
between Pb nuclei at 158 A GeV at the CERN SPS. We argue that this is evidence
that they are produced as topological defects arising from the formation of
disoriented chiral condensates (DCC) with an average domain size of about 2 fm.Comment: version 2 containing formulas, accepted by PR
The BTC40 Survey for Quasars at 4.8 < z < 6
The BTC40 Survey for high-redshift quasars is a multicolor search using
images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope
in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The
survey covers 40 sq. deg. in B, V, & I and 36 sq. deg. in z. Limiting
magnitudes (3 sigma) reach to V = 24.6, I = 22.9 and z = 22.9. We used the
(V-I) vs. (I-z) two-color diagram to select high-redshift quasar candidates
from the objects classified as point sources in the imaging data. Follow-up
spectroscopy with the AAT and CTIO 4-m telescopes of candidates having I < 21.5
has yielded two quasars with redshifts of z = 4.6 and z = 4.8 as well as four
emission line galaxies with z = 0.6. Fainter candidates have been identified
down to I = 22 for future spectroscopy on 8-m class telescopes.Comment: 27 pages, 8 figures; Accepted for publication in the Astronomical
Journa
Looking For Disoriented Chiral Condensates From Pion Distributions
We suggest two methods for the detection of the formation of disoriented
chiral condensates in heavy ion collisions. We show that the variance in the
number of charged pions (in a suitable range of momentum space) provides a
signature for the observation of a disoriented chiral condensate. The signal
should be observable even if multiple domains of DC form provided the
average number of pions per domain is significantly larger than unity. The
variance of the number charged pions alone provides a signal which can be used
even if the number of neutral pions cannot be measured in a given detector. On
the other hand, the probability distribution in , the proportion of neutral
pions to all pions emitted in heavy ion collisions in certain kinematic
regions, has been suggested as a signal of a disoriented chiral condensate.
Here we note that the signature can be greatly enhanced by making suitable cuts
in the data. In particular, we consider reducing the data set such that the
pions with lowest are all neutral. We find that, given such cuts,
can be substantially different from 1/3. For example, for a single D$\chi$C
domain without contamination due to incoherently emitted pions, is 3/5
given the pion with lowest is neutral, and 5/7 given the two pions with
lowest are both neutral, {\it etc.}. The effects of multi-domain DC
formation and noise due to incoherent pion emission can be systematically
incorporated. Potential applications to experiments and their limitations are
briefly discussed.Comment: 16 pages in REVTeX, 7 figures. Combined and updated version of
nucl-th/9903029 and nucl-th/9904074. Accepted by Phys. Rev.
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