744 research outputs found
Phase diagrams of classical spin fluids: the influence of an external magnetic field on the liquid-gas transition
The influence of an external magnetic field on the liquid-gas phase
transition in Ising, XY, and Heisenberg spin fluid models is studied using a
modified mean field theory and Gibbs ensemble Monte Carlo simulations. It is
demonstrated that the theory is able to reproduce quantitatively all
characteristic features of the field dependence of the critical temperature
T_c(H) for all the three models. These features include a monotonic decrease of
T_c with rising H in the case of the Ising fluid as well as a more complicated
nonmonotonic behavior for the XY and Heisenberg models. The nonmonotonicity
consists in a decrease of T_c with increasing H at weak external fields, an
increase of T_c with rising H in the strong field regime, and the existence of
a minimum in T_c(H) at intermediate values of H. Analytical expressions for
T_c(H) in the large field limit are presented as well. The magnetic para-ferro
phase transition is also considered in simulations and described within the
mean field theory.Comment: 14 pages, 12 figures (to be submitted to Phys. Rev. E
Analysis of BRAF and NRAS Mutation Status in Advanced Melanoma Patients Treated with Anti-CTLA-4 Antibodies: Association with Overall Survival?
Ipilimumab and tremelimumab are human monoclonal antibodies (Abs) against cytotoxic T-lymphocyte antigen-4 (CTLA-4). Ipilimumab was the first agent to show a statistically significant benefit in overall survival in advanced melanoma patients. Currently, there is no proven association between the BRAFV600 mutation and the disease control rate in response to ipilimumab. This analysis was carried out to assess if BRAFV600 and NRAS mutation status affects the clinical outcome of anti-CTLA-4-treated melanoma patients. This is a retrospective multi-center analysis of 101 patients, with confirmed BRAF and NRAS mutation status, treated with anti-CTLA-4 antibodies from December 2006 until August 2012. The median overall survival, defined from the treatment start date with the anti-CTLA-4. Abs-treatment to death or till last follow up, of BRAFV600 or NRAS mutant patients (n = 62) was 10.12 months (95% CI 6.78-13.2) compared to 8.26 months (95% CI 6.02-19.9) in BRAFV600/NRASwt subpopulation (n = 39) (p = 0.67). The median OS of NRAS mutated patients (n = 24) was 12.1 months and although was prolonged compared to the median OS of BRAF mutated patients (n = 38, mOS = 8.03 months) or BRAFV600/NRASwt patients (n = 39, mOS = 8.26 months) the difference didn't reach statistical significance (p = 0.56). 69 patients were able to complete 4 cycles of anti-CTLA-4 treatment. Of the 24 patients treated with selected BRAF- or MEK-inhibitors, 16 patients received anti-CTLA 4 Abs following either a BRAF or MEK inhibitor with only 8 of them being able to finish 4 cycles of treatment. Based on our results, there is no difference in the median OS in patients treated with anti-CTLA-4 Abs implying that the BRAF/NRAS mutation status alone is not sufficient to predict the outcome of patients treated with anti-CTLA-4 Abs
Understanding Giardia infections among rural communities using the one health approach
The epidemiology of giardiasis in rural villages in Peninsular Malaysia was examined in the context of the One
Health triad that encompasses humans, animals and environment (i.e. river water). A cross-sectional study was
carried out among five rural communities in Malaysia to determine the prevalence of Giardia duodenalis in
humans, animals and river water. Fecal samples collected from humans and animals were examined by light
microscopy. Water was sampled from the rivers adjacent to the target communities and investigated for the
occurrence of Giardia cysts. The isolated cysts were further genotyped targeting the glutamate dehydrogenase
and triosephosphate isomerase genes. The overall prevalence of G. duodenalis was 6.7% (18/269) and 4.7% (8/
169) among humans and animals, respectively. Giardia cysts (mean concentration range: 0.10–5.97 cysts/L)
were also found in adjacent rivers at four out of the five villages examined. At Kemensah and Kuala Pangsun,
Giardia cysts were isolated from humans [rate: 3.7% each (of 54 each)], animals [rates: 6.3% (of 62) and 11.3%
(of 16), respectively] and river water [average concentration of 9 samples each: 0.83 ± 0.81 and 5.97 ± 7.00,
respectively]. For both villages at Pos Piah and Paya Lebar, 12.2% (of 98) and 6.1% (of 33) of collected human
samples were infected, respectively whilst none of the collected animals samples in these villages were found to
be positive. The river water samples of these two villages were also contaminated (average concentration:
0.20 ± 0.35 (of 9) and 0.10 ± 0.19 (of 3), respectively). In conclusion, Giardia cysts were simultaneously
observed in the human-animal-environment (i.e., river water) interfaces in at least two of five studied communities highlighting a vital need to improve understanding on the interplay of transmission dynamics, the role
of infected humans and animals in contaminating the water sources and the role of water as a vehicle of disease
transmission in these communities. Indeed, this study illustrates the One Health approach which is to recognize
that the optimal health of humans are interconnected with the well-being of animals and their environment
Effects of a Cognitive Behavioral Therapy Intervention Trial to Improve Disease Outcomes in Children with Inflammatory Bowel Disease:
Studies testing the efficacy of behavioral interventions to modify psychosocial sequelae of IBD in children are limited. This report presents outcomes through a six month follow up from a large RCT testing the efficacy of a cognitive-behavioral intervention for children with IBD and their parents
The role of coping with symptoms in depression and disability: Comparison between Inflammatory Bowel Disease and Abdominal Pain
Inflammatory Bowel Disease (IBD) and abdominal pain of functional origin (AP) are common gastrointestinal disorders in children that are associated with increased risk for depression and disability. Both symptom severity and coping with symptoms may contribute to these outcomes. We hypothesized that children with AP use different coping strategies compared to those with IBD for a number of reasons, including the fact that fewer treatment options are available to them. We also examined if coping was related to depression and functional disability beyond the contributions of symptom severity
Cognitive Mediators of Treatment Outcomes in Pediatric Functional Abdominal Pain
Cognitive-behavioral interventions improve outcomes for many pediatric health conditions, but little is known about which mechanisms mediate these outcomes. The goal of this study was to identify whether changes in targeted process variables from baseline to one week post-treatment mediate improvement in outcomes in a randomized controlled trial of a brief cognitive-behavioral intervention for idiopathic childhood abdominal pain
A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007
We present the results of the first search for gravitational wave bursts
associated with high energy neutrinos. Together, these messengers could reveal
new, hidden sources that are not observed by conventional photon astronomy,
particularly at high energy. Our search uses neutrinos detected by the
underwater neutrino telescope ANTARES in its 5 line configuration during the
period January - September 2007, which coincided with the fifth and first
science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed
for candidate gravitational-wave signals coincident in time and direction with
the neutrino events. No significant coincident events were observed. We place
limits on the density of joint high energy neutrino - gravitational wave
emission events in the local universe, and compare them with densities of
merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at
http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access
area to figures, tables at
https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
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