Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

THE TOXIC EFFECTS OF CARBON DIOXIDE AND ACETAZOLAMIDE IN HEPATIC ENCEPHALOPATHY * By JEROME B.

Striking alterations in respiratory gas and blood ammonia levels usually accompany hepatic coma. The arterial pH is elevated and the carbon dioxide tension reduced (1). The blood ammonia level (2-4) is increased in many instances and the brain arteriovenous ammonia difference is high (5, 6). The cerebral oxygen uptake is depressed (7, 8). Whether the pronounced alkalosis which accompanies many instances of hepatic comiia contributes to the encephalopathy is unknown. Severe blood alkalosis impairs oxyhemoglobin dissociation (9), lowers the arterial oxygen partial pressure and interferes with cerebral function in normal subjects (10). Alkalosis is reported to enhance ammonia toxicity (11-13). These effects led Roberts and associates (14) as well as others (13) to suggest using carbon dioxide inhalation to treat hepatic coma. Prelimiiinary clinical observations on our own services suggested that inhaled CO2 worsened rather than improved patients with the encephalopathy of liver disease. Accordingly, detailed clinical and cerebral metabolic studies were carried out to quantitate the effects on brain function of raising blood and tissue CO2 tensions. The results of the study are reported here. Cerebral blood flow and cerebral oxygen uptake were measured at rest in control and cirrhotic patients and the results were correlated with the patients ' mental and somatic neurological function. Following the baseline study, selected patients inhaled carbon dioxide and the clinical cerebral metabolic observations were repeated. Subsequently, to eliminate the undesirable side effects of hyperpnea and dyspnea as contributing to the observed changes, similar observations were made before and after raising tissue CO2 tensions by rapidly infusing acetazolamide (Diamox). * Aided by a grant (2B-5067) from the United State

The diagnosis of stupor and coma

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