Searches for Ultra-High-Energy Photons at the Pierre Auger Observatory

The Pierre Auger Observatory, which is the largest air-shower experiment in the world, offers unprecedented exposure to neutral particles at the highest energies. Since the start of data collection more than 18 years ago, various searches for ultra-high-energy (UHE, E greater than or similar to 10^(17) eV) photons have been performed, either for a diffuse flux of UHE photons, for point sources of UHE photons or for UHE photons associated with transient events such as gravitational wave events. In the present paper, we summarize these searches and review the current results obtained using the wealth of data collected by the Pierre Auger Observatory

A birth cohort study in the Middle East: the Qatari birth cohort study (QBiC) phase I

BACKGROUND: The latest scientific reports raise concerns about the rapidly increasing burden of chronic diseases in the state of Qatar. Pregnant Qatari women often confront complications during pregnancy including gestational diabetes, hypertension, abortion and stillbirth. The investigation of early life environmental, genetic, nutritional and social factors that may affect lifelong health is of great importance. Birth cohort studies offer a great opportunity to address early life hazards and their possible long lasting effects on health. METHODS/DESIGN: The Qatari Birth Cohort study is the first mother-child cohort study in the Middle East Area that aims to assess the synergetic role of environmental exposure and genetic factors in the development of chronic disease and monitor woman and child health and/or obstetric characteristics with high prevalence. The present manuscript describes the recruitment phase of the study (duration: 2 years; expected number: 3000 families), where the pregnant Qatari women and their husbands are being contacted before the 15th week of gestation at the Primary Health Care Centers. The consented participants are interviewed to obtain information on several factors (sociodemographic characteristics, dietary habits, occupational/environmental exposure) and maternal characteristics are assessed based on anthropometric measurements, spirometry, and blood pressure. Pregnant women are invited to provide biological samples (blood and urine) in each trimester of their pregnancy, as well as cord blood at delivery. Fathers are also asked to provide biological samples. DISCUSSION: The present study provides invaluable insights into a wide range of early life factors affecting human health. With a geographical focus on the Middle East, it will be a resource for information to the wider scientific community and will allow the formulation of effective policies with a primary focus on public health interventions for maternal and child health

Effects of cardiac-restricted overexpression of the A2A adenosine receptor on adriamycin-induced cardiotoxicity

Activation of the A2A adenosine receptor (A2AR) has been shown to be cardioprotective. We hypothesized that A2AR overexpression could protect the heart from adriamycin-induced cardiomyopathy. Transgenic (TG) mice overexpressing the A2AR and wild-type mice (WT) were injected with adriamycin (5 mg·kg−1·wk−1 ip, 4 wk). All WT mice survived adriamycin treatment while A2AR TG mice suffered 100% mortality at 4 wk. Telemetry showed progressive prolongation of the QT interval, bradyarrhythmias, heart block, and sudden death in adriamycin-treated A2AR TG but not WT mice. Both WT and A2AR TG demonstrated similar decreases in heart function at 3 wk after treatment. Adriamycin significantly increased end-diastolic intracellular Ca2+ concentration in A2AR TG but not in WT myocytes (P < 0.05). Compared with WT myocytes, action potential duration increased dramatically in A2AR TG myoctyes (P < 0.05) after adriamycin treatment. Expression of connexin 43 was decreased in adriamycin treated A2AR TG but not WT mice. In sharp contrast, A2AR overexpression induced after the completion of adriamycin treatment resulted in no deaths and enhanced cardiac performance compared with WT adriamycin-treated mice. Our results indicate that the timing of A2AR activation is critical in terms of exacerbating or protecting adriamycin-induced cardiotoxicity. Our data have direct relevance on the clinical use of adenosine agonists or antagonists in the treatment of patients undergoing adriamycin therapy