The H.E.S.S. extragalactic sky

The H.E.S.S. Cherenkov telescope array, located on the southern hemisphere in Namibia, studies very high energy (VHE; E>100 GeV) gamma-ray emission from astrophysical objects. During its successful operations since 2002 more than 80 galactic and extra-galactic gamma-ray sources have been discovered. H.E.S.S. devotes over 400 hours of observation time per year to the observation of extra-galactic sources resulting in the discovery of several new sources, mostly AGNs, and in exciting physics results e.g. the discovery of very rapid variability during extreme flux outbursts of PKS 2155-304, stringent limits on the density of the extragalactic background light (EBL) in the near-infrared derived from the energy spectra of distant sources, or the discovery of short-term variability in the VHE emission from the radio galaxy M 87. With the recent launch of the Fermi satellite in 2008 new insights into the physics of AGNs at GeV energies emerged, leading to the discovery of several new extragalactic VHE sources. Multi-wavelength observations prove to be a powerful tool to investigate the production mechanism for VHE emission in AGNs. Here, new results from H.E.S.S. observations of extragalactic sources will be presented and their implications for the physics of these sources will be discussed.Comment: 8 pages, 6 figures, invited review talk, in the proceedings of the "International Workshop on Beamed and Unbeamed Gamma-Rays from Galaxies" 11-15 April 2011, Lapland Hotel Olos, Muonio, Finland, Journal of Physics: Conference Series Volume 355, 201

obesity weight loss and heart failure

Background The current scientific data controversially indicate obesity both as a risk factor for developing congestive heart failure (CHF) and a positive prognostic factor. Aims The present study evaluated the impact of weight loss on clinical and instrumental parameters in a selected group of obese patients with CHF. Methods An overall population of 560 HF patients was sub-grouped on the basis of the Body Mass Index (BMI): 8.2% were underweight (BMI 31). Of the 46 overweight and obese patients, 28 (55.2% men, age 51–80 years) accepted a tailored low-caloric dietary program for at least 4 months. The 28 patients belonged to both obese and overweight groups (BMI>27.8) and were in NYHA classes II–III. Mean follow-up was 5 months. Results The mean loss of body weight was 4 kg in 81.4% of patients, versus 3 kg mean increase in whole (560 patients) population (72.5–75.5 kg). In the 28 patients we recorded a significant ( p <0.05) improvement of NYHA class, better control of arterial blood pressure and statistically significant ( p <0.05) lowering of total cholesterol and triglyceride levels. Conclusions Tailored dietetic program may improve clinical and instrumental parameters in patients with CHF

New AGNs discovered by H.E.S.S

During the last year, six new Active Galactic Nuclei (AGN) have been discovered and studied by H.E.S.S. at Very High Energies (VHE). Some of these recent discoveries have been made thanks to new enhanced analysis methods and are presented at this conference for the first time. The three blazars 1ES 0414+009, SHBL J001355.9-185406 and 1RXS J101015.9-311909 have been targeted for observation due to their high levels of radio and X-ray fluxes, while the Fermi/LAT catalogue of bright sources triggered the observation of PKS 0447-439 and AP Librae. Additionally, the BL Lac 1ES 1312-423 was discovered in the field-of-view (FoV) of Centaurus A thanks to the large exposure dedicated by H.E.S.S. to this particularly interesting source. The newly-discovered sources are presented here and in three companion presentations at this conference.Comment: 8 pages, 3 figures, proceeding from the 25th Texas Symposium on Relativistic Astrophysics (Heidelberg, Germany, 2010

Time variations in the deep underground muon flux measured by MACRO

More than 30 million of high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different natures. Two kinds of studies were carried out: search for periodic variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and Scan Test statistics have been applied to the data.Comment: 6 pages, 4 EPS figures. Talk given at the 29th ICRC, Pune, India, 3-10 August 200

Microclimatic monitoring for the assessment of the conservation conditions of the stucco statues in the UNESCO site of the Longobard Temple in Cividale del Friuli -Udine (Italy)

The Longobard Temple, built around the middle of the 8th century, is part of wider complex including the Saint Maria in Valley monastery edified in the following centuries, located in Cividale del Friuli - Udine (Italy). Both the temple and the monastery have been declared by UNESCO world heritage sites in 2011. The Temple constitute one of the few extraordinary testimonials preserved of the Longobard architecture, testify also by the six saints in high relief placed leaned to the west wall side by side in ternary groups, to the right and to the left of the blind lancet window. A microclimatic monitoring of the temple was performed between 2011 and 2012 by the Padova Unit of the Institute of Atmospheric Sciences and Climate, as part of the diagnostic project promoted by the City Council of Cividale del Friuli, in order to investigate the causes of the different damage features affecting the statues on the two sides of the west wall and to eventually identify suitable actions for the improvement of the current conservation conditions. In order to assess the microclimatic conditions, air temperature and relative humidity were recorded automatically for one year nearby the two central female figures. In addition, seasonal thermographic measurements were carried out to evaluate the thermal variations of the material and then they were compared to the microclimatic measurements. Furthermore some anemometers were installed in strategic points of the Temple for the automatic monitoring of the movement of the air masses to evaluate the impact of the air masses on the statues. The results of the microclimatic monitoring of the Longobard Temple showed that the different conservation conditions of the statues at the two sides of the west wall cannot be directly related to the actual microclimatic conditions. They could be more reasonably related to the history of the Temple (it seems that in the past they have been exposed to weather impact) and to past restoration works. In fact, according to the microclimatic results, the two sides of the west wall are subjected during the course of the year to similar daily thermal variations , even if in different seasons, due to the natural course of solar radiation during the whole year. Moreover, the movement of air masses observed and also simulated by means of a fluid-dynamic model resulted to have a different impact on the two wall sides. Nevertheless, this phenomenon can be more properly related to the risk of airborne particle deposition processes. In conclusions, the actual microclimatic conditions cannot be considered responsible for the different conservation conditions of the statues of the two sides of the west wall, but, if not improved, they could have a different impact on the statues that have different state of conservation

Detection potential to point-like neutrino sources with the NEMO-km3 telescope

The NEMO Collaboration is conducting an R&D activity towards the construction of a Mediterranean km3 neutrino telescope. In this work, we present the results of Monte Carlo simulation studies on the capability of the proposed NEMO telescope to detect and identify point-like sources of high energy muon neutrinos.Comment: To be published on BCN06 proceedings (Barcelona, July 4-7, 2006

Protective Structures for the Conservation of Archaeological Sites : environmental considerations on the shelters over the Hagar Qim and Mnajdra temples of Malta

The Megalithic Temples of Hagar Qim and Mnajdra, constructed in Qrendi between the mid-fourth and mid-third millennia BC, are amongst the oldest free-standing stone buildings of such complexity in the world. They are of great local and international significance and they have been included since 1992 on the UNESCO's World Heritage List. These Temples are currently suffering from a series of severe structural problems as well as different forms of stone deterioration: the Globigerina Limestone shows powdering, flaking and scaling of the surface, as well as alveolar weathering, mainly due to salt crystallisation, in particular of chlorides acting on the very porous stone. Protective structures have long been considered the best in situ measures for preventive conservation of archaeological sites. However, the nature of problems in conserving sites under protective structures varies widely. The design of a new structure should improve the environmental conditions for the archaeological materials and structures themselves and it should also respond to the presentation requirements for visitors to the site. Between 2008 and 2009 the vulnerable prehistoric structures of Hagar Qim and Mnajdra were protected from the direct impact of environmental factors by means of a reversible, lightweight, open-sided shelter, conceived with minimal visual and physical impact. The main protective features of the shelter are its ability to eliminate the effects of water through rainfall, reducing water runoff and preventing the leaching of infills.The shelters also mitigate the effects of solar radiation by directly shading the Temples, thus reducing thermoclastic weathering. Finally they reduce wind impact and herbaceous growth. Several microclimatic campaigns have been performed in different locations and periods of times in the two Temples and their surroundings since 2005, before the sheltering, and they are still going on, to assess the impact of the shelters on the microclimatic conditions of the Temples. Air temperature and relative humidity are being recorded in different points inside and outside the Temples to investigate the effects of the shelters on thermo-hygrometric variations, wetting-and-drying cycles, as well as on the hygrometric levels and consequently on the risk of biological growth. At the same time, the thermal behaviour of the stone under the shelter is being investigated in the Hagar Qim Temple, by means of surface temperature measurements of differently oriented model stone pieces. Moreover, the wind funnelling phenomenon has been studied in the Hagar Qim temple complex. According to the results wind speed does not increase beneath the shelter except at certain points within the temple structure itself. The performance of the shelters is still currently being assessed by environmental monitoring which already indicates a general improvement of the conditions beneath the shelters to the ones on site before sheltering