Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory

The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal

The Role of IL-6, 8, and 10, sTNFr, CRP, and Pancreatic Elastase in the Prediction of Systemic Complications in Patients with Acute Pancreatitis

Background and Aim. Early assessment of severity in acute pancreatitis (AP) is a key measure to provide rational and effective management. The aim of our study is to determine the prognostic value of interleukins (IL) 6, 8, and 10, soluble receptor for tumor necrosis factor (sTNFr), pancreatic elastase (E1), and C-reactive protein (CRP) as predictors of systemic complications in AP. Patients and Methods. A hundred and fifty patients with confirmed AP were enrolled in the study. The severity of AP was defined according to Atlanta criteria. Measurements of interleukins and sTNFr were performed on the first day of admission. CRP and E1 levels were assessed on admission and after 48 hours. ROC analysis was performed for all parameters. Results. Interleukins and sTNFr significantly differentiated patients with systemic complications from those without. Elevation of IL-6 showed the highest significance as a predictor (). CRP and elastase levels did not differ between mild and severe cases on admission, but reached statistical significance when measured on the third day ( and , resp.). Conclusion. Our study confirmed that IL-6, IL-8, IL-10, and sTNFr measured on admission, and CRP and pancreatic elastase measured on third day of admission represent valuable prognostic factors of severity and systemic complications of AP

Early nasojejunal tube feeding versus nil-by-mouth in acute pancreatitis: A randomized clinical trial

BACKGROUND/OBJECTIVES: There is substantial evidence of superiority of enteral nutrition (EN) to parenteral nutrition in acute pancreatitis (AP) treatment, but few studies evaluated its effectiveness compared to no intervention. The objective of our trial was to compare the effects of EN to a nil-by-mouth (NBM) regimen in patients with AP. METHODS: Patients with AP were randomized to receive either EN via a nasojejunal tube initiated within 24 h of admission or no nutritional support. Systemic inflammatory response syndrome (SIRS) was assessed as the primary outcome. Secondary outcomes included mortality, organ failure, local complications, infected pancreatic necrosis, surgical interventions, length of hospital stay, adverse events and inflammatory response intensity. Outcomes were compared using Student's t-test and Mann- Whitney U test as appropriate. RESULTS: 214 patients were randomized in total, 107 to each group. SIRS occurrence was similar between groups, with 48 (45%) versus 51 (48%), respectively (RR 0.94 ; 95% CI 0.71-1.26). No significant reduction of persistent organ failure (RR 0.81 ; 95% CI 0.52-1.27) and mortality (RR 0.59 ; 95% CI 0.28-1.23) was present in the EN group. There were no significant differences in other outcomes between the groups. When analyzing the occurrence of SIRS and mortality in subgroup of patients with severe disease no significant differences were noted. CONCLUSION: Our results showed no significant reduction of persistent organ failure and mortality in patients with AP receiving early EN compared to patients treated with no nutritional support (NCT01965873)

Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory

Extent: 50p.The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.The Pierre Auger Collaboration, P. Abreu... K. B. Barber... J. A. Bellido... R. W. Clay... M. J. Cooper... B. R. Dawson... T. A. Harrison... A. E. Herve... V. C. Holmes... J. Sorokin... P. S. Wahrlich.. B. J. Whelan... et al