The ZEPLIN-III dark matter detector: instrument design, manufacture and commissioning

We present details of the technical design and manufacture of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase xenon detector which measures both the scintillation light and the ionisation charge generated in the liquid by interacting particles and radiation. The instrument design is driven by both the physics requirements and by the technology requirements surrounding the use of liquid xenon. These include considerations of key performance parameters, such as the efficiency of scintillation light collection, restrictions placed on the use of materials to control the inherent radioactivity levels, attainment of high vacuum levels and chemical contamination control. The successful solution has involved a number of novel design and manufacturing features which will be of specific use to future generations of direct dark matter search experiments as they struggle with similar and progressively more demanding requirements.Comment: 25 pages, 19 figures. Submitted to Astropart. Phys. Some figures down sampled to reduce siz

Research Paper - Effect of folate treatment on homocysteinemia in cardiac patients: A prospective study

OBJECTIVE: To study the effect of folate treatment on homocysteine (HCY) levels in patients with Coronary Artery Disease (CAD). We also made an attempt to analyze HCY levels in relation to other risk factors present in these patients. MATERIALS AND METHODS: The study was a randomised, non-blind clinical trial carried out in 84 angiographically documented CAD patients and 40 controls (angiographically proved normal or treadmill test negative). Biochemical analyses of glucose, insulin, HCY, lipid profile and C-Reactive Proteins (CRP) were conducted in serum samples collected from these patients. Treatment with folic acid (5 mg/day) for 3 months was given to patients with hyperhomocysteinemia and the post-treatment HCY levels were analyzed. RESULTS: The mean plasma HCY level in control volunteers was found to be 17.85±1.4 µmol/L, which was significantly lower than those in CAD patients (24.69±2.8 µmol/L). The levels were higher in non-diabetic patients (30.33±3.9 µmol/L) as compared to non-diabetic controls (18.18±1.6 µmol/L) as well as diabetic patients (14.53±1.43 µmol/L), irrespective of the presence of hypertension. No correlation was found between total HCY (t-HCY) levels and serum glucose, insulin, triglycerides, VLDL, LDL, HDL, cholesterol or CRP levels. A negative correlation was found between t-HCY levels and the age of the patients. The HCY levels were highest in the younger age group of patients (30-40 years) (49±7.8 µmol/L). There was a significant reduction in t-HCY levels after the folate treatment in mild and moderate hyperhomocystienemic patients but the reduction in patients with severe hyperhomocysteinemia was not significant. CONCLUSION: CAD patients have higher HCY levels than subjects without CAD. Indian diabetic patients have lower levels of t-HCY irrespective of the presence of cardiac disease. Folate treatment decreases the t-HCY levels in homocysteinemia and thus can be used in treatment of homocysteinemia

Lentiviral Gene Therapy for Artemis-Deficient SCID.

BackgroundThe DNA-repair enzyme Artemis is essential for rearrangement of T- and B-cell receptors. Mutations in DCLRE1C, which encodes Artemis, cause Artemis-deficient severe combined immunodeficiency (ART-SCID), which is poorly responsive to allogeneic hematopoietic-cell transplantation.MethodsWe carried out a phase 1-2 clinical study of the transfusion of autologous CD34+ cells, transfected with a lentiviral vector containing DCLRE1C, in 10 infants with newly diagnosed ART-SCID. We followed them for a median of 31.2 months.ResultsMarrow harvest, busulfan conditioning, and lentiviral-transduced CD34+ cell infusion produced the expected grade 3 or 4 adverse events. All the procedures met prespecified criteria for feasibility at 42 days after infusion. Gene-marked T cells were detected at 6 to 16 weeks after infusion in all the patients. Five of 6 patients who were followed for at least 24 months had T-cell immune reconstitution at a median of 12 months. The diversity of T-cell receptor β chains normalized by 6 to 12 months. Four patients who were followed for at least 24 months had sufficient B-cell numbers, IgM concentration, or IgM isohemagglutinin titers to permit discontinuation of IgG infusions. Three of these 4 patients had normal immunization responses, and the fourth has started immunizations. Vector insertion sites showed no evidence of clonal expansion. One patient who presented with cytomegalovirus infection received a second infusion of gene-corrected cells to achieve T-cell immunity sufficient for viral clearance. Autoimmune hemolytic anemia developed in 4 patients 4 to 11 months after infusion; this condition resolved after reconstitution of T-cell immunity. All 10 patients were healthy at the time of this report.ConclusionsInfusion of lentiviral gene-corrected autologous CD34+ cells, preceded by pharmacologically targeted low-exposure busulfan, in infants with newly diagnosed ART-SCID resulted in genetically corrected and functional T and B cells. (Funded by the California Institute for Regenerative Medicine and the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT03538899.)

The ZEPLIN III Detector; Results from Surface Calibrations

ZEPLIN-III is a direct dark-matter search instrument using liquid xenon as a target.Both the scintillation light and the ionisation charge are measured.The instrument has been built and it is currently being testing in a surface laboratory.We present results from some of the initial testing, including design thermal control system verification, photomultiplier calibration (including spectral measurements with 60 keV photons from 241Am) and two-phase operation showing simultaneous measurement of scintillation and charge and position reconstruction

Investigation of stressful life events as significant predictors on depressive symptoms among Cypriot University students: a cross-sectional descriptive correlational study.

Background: Previous findings suggest that stressful life events have a causal relationship with depressive symptoms. However, to date little is known concerning the contribution of the number and severity of recent stressful life events on the prevalence of depressive symptoms among university students. The aim of this study was to investigate the prevalence of depressive symptoms and its association with the number and the severity of self-reported stressful life events among university students in Cyprus. Methods: A descriptive correlational design with cross sectional comparison was used. The CES-D scale was applied for the assessment of depressive symptoms and the LESS instrument for stressful life events. Both scales were completed anonymously and voluntarily by 1.500 students (response rate 85%). Results: The prevalence of mild to moderate depressive symptoms [CES-D score between 16 and 21] and of clinically significant depressive symptoms [CES-D score ≥ 22] were 18.8% and 25.3% respectively. There were statistically significant differences in clinically significant depressive symptoms by gender, with higher rates among women (x2 = 8.53, df = 1, p = 0.003). Higher scores on the LESS scale were associated with more frequent reports of clinical depressive symptoms (x2 = 70.63, df = 4, p < 0.001). Similarly, an association was found between the number of life events and clinical depressive symptoms (x2 = 40.06, df = 4, p < 0.001). Logistic regression analysis after adjusting for socio-demographic characteristics confirmed that the responders who reported a high number (n = 12–21) of stressful life events during the previous year (OR = 2.64 95% CI: 1.02, 6.83) and a severe degree of stress due to these events (total LESS score > 351, OR = 3.03 95% CI: 1.66, 5.39) were more likely to manifest clinical depressive symptoms. Conclusions: The high frequency of occurrence of depressive symptoms among Cypriot university students, as well as the strong association with stressful life events, highlights the need for psychological empowerment strategies towards students by institutional counseling services