First Results from the DRIFT-IIa Dark Matter Detector

Data from the DRIFT-IIa directional dark matter experiment are presented, collected during a near continuous 6 month running period. A detailed calibration analysis comparing data from gamma-ray, x-ray and neutron sources to a GEANT4 Monte Carlo simulations reveals an efficiency for detection of neutron induced recoils of 94+/-2(stat.)+/-5(sys.)%. Software-based cuts, designed to remove non-nuclear recoil events, are shown to reject 60Co gamma-rays with a rejection factor of better than 8x10-6 for all energies above threshold. An unexpected event population has been discovered and is shown here to be due to the alpha-decay of 222Rn daughter nuclei that have attached to the central cathode. A limit on the flux of neutrons in the Boulby Underground Laboratory is derived from analysis of unshielded and shielded data.Comment: 43 pages, 14 figures, submitted to Astroparticle Physic

Track Reconstruction and Performance of DRIFT Directional Dark Matter Detectors using Alpha Particles

First results are presented from an analysis of data from the DRIFT-IIa and DRIFT-IIb directional dark matter detectors at Boulby Mine in which alpha particle tracks were reconstructed and used to characterise detector performance--an important step towards optimising directional technology. The drift velocity in DRIFT-IIa was [59.3 +/- 0.2 (stat) +/- 7.5 (sys)] m/s based on an analysis of naturally-occurring alpha-emitting background. The drift velocity in DRIFT-IIb was [57 +/- 1 (stat) +/- 3 (sys)] m/s determined by the analysis of alpha particle tracks from a Po-210 source. 3D range reconstruction and energy spectra were used to identify alpha particles from the decay of Rn-222, Po-218, Rn-220 and Po-216. This study found that (22 +/- 2)% of Po-218 progeny (from Rn-222 decay) are produced with no net charge in 40 Torr CS2. For Po-216 progeny (from Rn-220 decay) the uncharged fraction is (100 +0 -35)%.Comment: 27 pages, 12 figures, 5 tables. Submitted to Nuclear Instruments and Methods in Physics Research, Section A. Subj-class: Instrumentation and Detector

Measurement of the Range Component Directional Signature in a DRIFT-II Detector using 252Cf Neutrons

The DRIFT collaboration utilizes low pressure gaseous detectors to search for WIMP dark matter with directional signatures. A 252Cf neutron source was placed on each of the principal axes of a DRIFT detector in order to test its ability to measure directional signatures from the three components of very low energy (~keV/amu) recoil ranges. A high trigger threshold and the event selection procedure ensured that only sulfur recoils were analyzed. Sulfur recoils produced in the CS2 target gas by the 252Cf source closely match those expected from massive WIMP induced sulfur recoils. For each orientation of the source a directional signal from the range components was observed, indicating that the detector is directional along all 3 axes. An analysis of these results yields an optimal orientation for DRIFT detectors when searching for a directional signature from WIMPs. Additional energy dependent information is provided to aid in understanding this effect.Comment: 14 pages, 1 Table, 8 Figure

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Oral adjuvant curcumin therapy for attaining clinical remission in ulcerative colitis: A systematic review and meta-analysis of randomized controlled trials

Curcumin has demonstrated anti-inflammatory properties and has been investigated as an adjuvant therapy of ulcerative colitis (UC). The scope of this study was to systematically review and meta-analyze the efficacy of oral curcumin administration as an adjuvant therapy of UC. MEDLINE, Cochrane/CENTRAL, ClinicalTrials.gov, WHO-ICT Registry, EMBASE and grey literature were searched for relevant randomized controlled trials (RCTs). The primary outcome was clinical remission (attainment) and the secondary outcome was clinical response (maintenance/failure). Risk of bias was assessed with the Cochrane tool. Odds ratios (OR) were calculated with a Mantel-Haenszel (M-H) random effects model and with a beta-binomial (B-B) random effects model when zero events/cells occurred. Four RCTs met the criteria, but one was removed from the analyses due to inconsistency in protocol details. With the M-H method, treatment with curcumin was significantly superior to placebo in attaining remission in the per-protocol (PP) analysis (OR = 5.83, 95%CI = 1.24–27.43), but not in the intention-to-treat (ITT) analysis (OR = 4.33, 95%CI = 0.78–24.00). However, with the more accurate B-B method, both analyses were insignificant (for PP OR = 4.26, 95%CI = 0.59–31.00, for ITT OR = 3.80, 95%CI = 0.55–26.28). Based on the current available evidence, oral curcumin administration does not seem superior to placebo in attaining remission in patients with UC. Future RCTs should be planned more cautiously with sufficient size and adhere to the ITT analysis in all outcomes. © 2018 by the authors. Licensee MDPI, Basel, Switzerland