The Pierre Auger Observatory has associated a few ultra high energy cosmic rays with the direction of Centaurus A. This source has been deeply studied in radio, infrared, X-ray and γ-rays (MeV-TeV) because it is the nearest radioloud active galactic nuclei. Its spectral energy distribution or spectrum shows two main peaks, the low energy peak, at an energy of 10 −2 eV, and the high energy peak, at about 150 keV. There is also a faint very high energy (E ≥ 100 GeV) γ-ray emission fully detected by the High Energy Stereoscopic System experiment. In this work we describe the entire spectrum, the two main peaks with a Synchrotron/Self-Synchrotron Compton model and, the Very High Energy emission with a hadronic model. We consider pγ and pp interactions. For the pγ interaction, we assume that the target photons are those produced at 150 keV in the leptonic processes. On the other hand, for the pp interaction we consider as targets the thermal particle densities in the lobes. Requiring a satisfactory description of the spectra at very high energies with pγ interaction we obtain an excessive luminosity in ultra high energy cosmic rays (even exceeding the Eddington luminosity). However, when considering pp interaction to describe the γ-spectrum, the obtained number of ultra high energy cosmic rays are in agreement with Pierre Auger observations. Moreover, we calculate the possible neutrino signal from pp interactions on a Km 3 neutrino telescope using Monte Carlo simulations.

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Abstract-The authors present full wave simulations and experimental results of propagation of electromagnetic waves in shallow seawaters. Transmitter and receiver antennas are tenturns loops placed on the seabed. Some propagation frameworks are presented and simulated. Finally, simulation results are compared with experimental ones.

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Objective. Patients with type 2 diabetes are encouraged to lose weight, but excessive weight loss in older adults may be a marker of poor health and subsequent mortality. We examined weight changes during the post-intervention period of Look AHEAD, a randomized trial comparing intensive lifestyle intervention (ILI) and diabetes support and education (DSE; control) in individuals with overweight/obesity and type 2 diabetes and sought to identify predictors of excessive post-intervention weight loss and its association with mortality. <p>Research Design and Methods. These secondary analyses compared post-intervention weight change (year-8 to final visit [median 16 years]) in ILI and DSE in 3999 Look AHEAD participants. Using empirically derived trajectory categories, we compared four subgroups: Weight Gainers (N= 307), Weight Stable (N=1561), Steady Losers (N=1731) and Steep Losers (N=380) on post-intervention mortality, demographic variables and health status at randomization and year-8.</p> <p>Results. Post-intervention weight change averaged -3.7 ±9.5%, with greater weight loss in DSE than ILI. The steep weight loss trajectory subgroup lost on average 17.7 + 6.6%.; 30% of Steep Losers died during post-intervention follow-up vs 10-18% in other trajectories (p<. 0001). The following variables distinguished Steep Losers from Weight Stable: <i>Baseline </i>- older; longer diabetes duration; higher BMI; greater multimorbidity; <i>Intervention </i>– randomization to control group; less weight loss in years 1-8; <i>Year 8 </i>- higher prevalence of frailty, multimorbidity and depressive symptoms; lower use of weight control strategies. </p> <p>Conclusion. Steep weight losses post-intervention were associated with increased risk of mortality. Older individuals with longer duration diabetes and multi-morbidity should be monitored for excessive, unintentional weight loss. </p>