Determination of the Night Sky Background around the Crab pulsar using its optical pulsation

The poor angular resolution of imaging gamma-ray telescopes is offset by the large reflector areas of next generation telescopes such as MAGIC (17~m diameter), which makes the study of optical emission associated with some gamma-ray sources feasible. Furthermore, the extremely fast time response of photomultipliers (PMs) makes them ideal detectors for fast (subsecond) optical transients and periodic sources like pulsars. The optical pulse of the Crab pulsar was detected with the HEGRA CT1 central pixel using a modified PM, similar to the future MAGIC camera PMs. The purpose of these periodic observations was to determine the light of the night sky (LONS) for the galactic anticenter Crab region.Our results are between 2.5 and 3 times larger than the previously measured LONS (outside the galactic plane), as expected since the Crab pulsar is in the galactic plane, which implies a slightly higher energy threshold for Crab observations, if the higher value of CT1 measured LONS rate for galactic sources is used.Comment: 19 pages, 6 figures, accepted by Astroparticle Physic

Local dependence in bivariate copulae with beta marginals

The local dependence function (LDF) describes changes in the correlation structure of continuous bivariate random variables along their range. Bivariate density functions with Beta marginals can be used to model jointly a wide variety of data with bounded outcomes in the (0,1) range, e.g. proportions. In this paper we obtain expressions for the LDF of bivariate densities constructed using three different copula models (Frank, Gumbel and Joe) with Beta marginal distributions, present examples for each, and discuss an application of these models to analyse data collected in a study of marks obtained on a statistics exam by postgraduate students

Production cross-sections and momentum distributions of fragments from neutron-deficient 36Ar at 1.05 A.GeV

We have measured production cross sections and longitudinal momentum distributions of fragments from neutron-deficient 36Ar at 1.05 A.GeV. The production cross-sections show excellent agreement with the predictions of the semiempirical formula EPAX. We have compared these results, involving extremly neutron deficient nuclei, with model calculations to extract informa tion about the response of these models close to the driplines. The longitudinal momentum distributions have also been extracted and are compared with the Goldhaber and Morrissey systematics.Comment: 16 pages, 6 figure

Energy reconstruction in a highly granularity semi-digital hadronic calorimeter

International audienceThe Semi-Digital Hadronic CALorimeter(SDHCAL) using Glass Resistive Plate Chambers (GRPCs) is one of the calorimeters proposed for particle physics experiments at the future electron-positron collider. It is a high granularity calorimeter which is required for the application of the particle flow algorithm in order to improve the jet energy resolution as one of the goals of this experiments. We discuss the energy reconstruction, based on digital and semi-Digital methods, to study the effect on the improvement of the single particle energy resolution and the linearity of the detecor response. This study was performed with the GEANT4 simulation. Results on the energy resolution and linearity, for negative pions over an energy range from 1 to 100 GeV are presented and compared with different energy reconstruction methods including Artificial Neural Networks. 1. Introduction The CALICE collaboration [1] has developed several calorimeter prototypes to evaluate the most appropriate one to be used in the future Linear Collider. One of them is the semi-digital hadronic calorimeter (SDHCAL) constructed in IPNL with the collaboration of other laboratories. In this paper we first present the geometry of this prototype used in simulation. Then, we present the different techniques of energy reconstruction used in SDHCAL. Finally, the results of the energy resolution and linearity obtained are presented and commented upon

The association between childhood hearing loss and self-reported peer victimisation, depressive symptoms, and self-harm: longitudinal analyses of a prospective, nationally representative cohort study

BACKGROUND: Childhood hearing loss (HL) predicts poor mental health and is associated with a higher risk of communication difficulties. The relationship of childhood HL with specific types of poor mental health (such as depressive symptoms or self-harm) and peer victimisation remains unclear. METHODS: We analysed data from the Millennium Cohort Study (MCS), a prospective observational cohort study of children living in the UK at age 9 months and born between 2000 to 2002. Data were available on the children and their families at ages 9 months, then at 3, 5, 7, 11, and 14 years. Participants were 10,858 singleton children with self-reported data on peer victimisation, depressive symptoms, and self-harm at age 14 years. Multivariable logistic regression models were fitted to estimate odds ratios (OR) for HL with peer victimisation, depressive symptoms, and self-harm. HL presence was examined in terms of any HL between ages 9 months and 14 years, as well as by HL trajectory type (defined by onset and persistence). Analyses were adjusted for potential sources of confounding, survey design, and attrition at age 14 years. Interactions between sex and HL were examined in each model and multiple imputation procedures used to address missing data. RESULTS: Children with any HL had increased odds of depressive symptoms (OR: 1.32, 95% CI: 1.09–1.60), self-harm (1.41, 1.12–1.78) and, in girls only, peer victimisation (girls: 1.81, 1.29–2.55; boys: 1.05, 0.73–1.51), compared to those without HL. HL with later age at onset and persistence to age 14 years was the only trajectory associated with all outcomes. CONCLUSIONS: Childhood HL may predict peer victimisation (in girls), depressive symptoms, and self-harm. Further research is needed to identify HL trajectories and methods to facilitate good mental health in children with HL. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-13457-6

Estimating the number of livebirths to Hepatitis C seropositive women in England in 2013 and 2018 using Bayesian modelling.

BACKGROUND: The UK National Screening Committee currently recommends against antenatal screening for Hepatitis C virus (HCV) infection in England due to lack of HCV prevalence data and treatment licensed for use in pregnancy. We aimed to produce regional and national estimates of the number and proportion of livebirths to HCV seropositive women in England in 2013 and 2018. METHODS: A logistic regression model fitted in the Bayesian framework estimated probabilities of HCV seropositivity among 24,599 mothers delivering in the North Thames area of England in 2012 adjusted by maternal age and region of birth. These probabilities were applied to the underlying population structures of women delivering livebirths in England in 2013 and 2018 to estimate the number of livebirths to HCV seropositive women in these years nationally and by region. The Bayesian approach allowed the uncertainty associated with all estimates to be properly quantified. RESULTS: Nationally, the estimated number of livebirths to women seropositive for HCV for England was 464 (95% credible interval [CI] 300-692) in 2013 and 481 (95%CI 310-716) in 2018, or 70.0 (95%CI 45.0-104.1) per 100,000 and 76.9 (95%CI 49.5-114.4) per 100,000 in these years respectively. Regions with the highest estimated number of livebirths to HCV seropositive women in 2013 and 2018 included London with 118.5 and 124.4 and the South East with 67.0 and 74.0 per 100,000 livebirths. CONCLUSION: Few previous studies have investigated HCV among pregnant women in England. These findings complement and supplement existing research by providing national and regional estimates for the number of livebirths to HCV seropositive women in England. Bayesian modelling allows future national and regional estimates to be produced and the associated uncertainty to be properly quantified

Presentation for care and antenatal management of HIV in the United Kingdom:temporal trends and demographic variations, 2009-2014

OBJECTIVES: Despite very low rates of vertical transmission of HIV in the UK overall, rates are higher among women starting antenatal antiretroviral therapy (ART) late. We investigated the timing of key elements of the care of HIV‐positive pregnant women [antenatal care booking, HIV laboratory assessment (CD4 count and HIV viral load) and antenatal ART initiation], to assess whether clinical practice is changing in line with recommendations, and to investigate factors associated with delayed care. METHODS: We used the UK's National Study of HIV in Pregnancy and Childhood for 2009−2014. Data were analysed by fitting logistic regression and Cox proportional hazards models. RESULTS: A total of 5693 births were reported; 79.5% were in women diagnosed with HIV prior to that pregnancy. Median gestation at antenatal booking was 12.1 weeks [interquartile range (IQR) 10.0–15.6 weeks] and booking was significantly earlier during 2012–2014 vs. 2009–2011 (P < 0.001), although only in previously diagnosed women. Overall, 42.2% of pregnancies were booked late (≥ 13 gestational weeks). Among women not already on treatment, antenatal ART commenced at a median of 21.4 (IQR18.1–24.5) weeks and started significantly earlier in the most recent time period (P < 0.001). Compared with previously diagnosed women, those newly diagnosed during the current pregnancy booked later for antenatal care and started antenatal ART later (both P < 0.001). Multivariable analyses revealed demographic variations in access to or uptake of care, with groups including migrants and parous women initiating care later. CONCLUSIONS: Although women are accessing antenatal and HIV care earlier in pregnancy, some continue to face barriers to timely initiation of antenatal care and ART