A new deep SCUBA survey of gravitationally lensing clusters

We have conducted a new deep SCUBA survey, which has targetted 12 lensing galaxy clusters and one blank field. In this survey we have detected several sub-mJy sources after correcting for the gravitational lensing by the intervening clusters. We here present the preliminary results and point out two highlights.Comment: 4 pages, 2 figures, "Multiwavelength Cosmology" Mykonos, June 2003, conference proceeding

VITAL: an IDEAL stage 2b feasibility study of a randomised controlled trial evaluating whether virtual reality technology can improve surgical training in Sierra Leone

Background: Training surgeons is costly and resource intensive, often requiring extended periods of expert supervision. Virtual reality (VR) has shown potential in enhancing surgical skill acquisition, but its use in low- and middle-income countries (LMICs) remains limited. This study aimed to evaluate the feasibility of using smartphone VR for surgical training in LMICs. Methods: We conducted a prospective randomised controlled feasibility study involving surgical trainees recruited from a government teaching hospital in Freetown, Sierra Leone. Participants were randomised 1:1 VR vs non-VR and received a 2-day hands-on course on lower limb amputation. The VR group received additional VR training consisting of two 30-minute modules with narrated live surgery videos. Feasibility outcomes included recruitment rates, VR intervention adherence, fidelity and acceptability. Results: A total of 30 participants were randomised, 15 to the VR group and 15 to the control group. The recruitment period lasted 2 days, and 29 participants (96.7%) completed the course. The VR intervention had high fidelity and acceptability, with 100% of participants completing the intervention. There was no unblinding. Compared to the control group, the VR group reported statistically significantly higher engagement during the hands-on course. Conclusion: Our findings suggest that smartphone VR is technically feasible for surgical training in LMICs, and may improve engagement and perceived learning. With minor modifications to the intervention and assessments, a larger-scale trial is feasible. These results highlight the potential for VR to address the challenges of surgical training in LMICs, where access to expert supervision and costly training resources may be limited

Visual Disamenity in the Queensland Wet Tropics: Estimating the Economic Impacts of Overhead Transmission Lines

This paperexamines procedures and findings in estimation of the 'visual disamenity cost' associated with installation of high-voltage overhead power lines in the Wet Tropics of Queensland. The study was performed within a short timeframe and small budget, hence the need to design a relatively simple and cost-effective approach, yet one which would yield acceptable information on environmental values. An extensive literature review and advice from a number of resource economists indicated that there was little information from previous studies to support benefit transfer methodology. It was found possible to estimate disamenity costs to ecotourism operation (using a simplified travel cost approach), agricultural operations (based on compensation payments) and residential property values (through a simplified hedonic price approach). A planned contingent valuation of the intrusive effect of the transmission lines through rainforest areas did not proceed, due at least in part to the political sensitivity of this issue

Hide your pain : social threat increases pain reports and aggression, but reduces facial pain expression and empathy

Earlier research studying the effects of social threat on the experience and expression of pain led to mixed results. In this study, female participants (N = 32) came to the lab with 2 confederates. Both confederates administered a total of 10 painful electrocutaneous stimuli to the participant. The framing of the administration was manipulated in a within-subjects design: In the low social threat condition the participant was told that the confederate could choose between 10 and 20 pain stimuli, thus they believed that this confederate chose to administer the minimum allowed number of pain stimuli. In the high social threat condition the confederate had a choice between 1 and 10 stimuli, thus they believed that this confederate chose to administer the maximum allowed number of stimuli. Participants reported on the intensity, unpleasantness, and threat value of the painful stimuli, and their facial expression was recorded. Moreover, aggression and empathy toward the confederates were assessed. As hypothesized, participants reported increased pain intensity, unpleasantness, and threat in the high social threat condition compared to the low social threat condition, but showed less facial pain expression. Finally, participants exhibited increased aggression and reduced empathy toward the confederate in the high social threat condition. Perspective: Social threat reduces painful facial expression, but simultaneously increases pain reports, leading to a double burden of the person in pain. Additionally, social threat affected social relationships by increasing aggression and reducing empathy for the other

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

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

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