Long-term Monitoring on Mrk 501 for Its VHE gamma Emission and a Flare in October 2011

As one of the brightest active blazars in both X-ray and very high energy $\gamma$-ray bands, Mrk 501 is very useful for physics associated with jets from AGNs. The ARGO-YBJ experiment is monitoring it for $\gamma$-rays above 0.3 TeV since November 2007. Starting from October 2011 the largest flare since 2005 is observed, which lasts to about April 2012. In this paper, a detailed analysis is reported. During the brightest $\gamma$-rays flaring episodes from October 17 to November 22, 2011, an excess of the event rate over 6 $\sigma$ is detected by ARGO-YBJ in the direction of Mrk 501, corresponding to an increase of the $\gamma$-ray flux above 1 TeV by a factor of 6.6$\pm$2.2 from its steady emission. In particular, the $\gamma$-ray flux above 8 TeV is detected with a significance better than 4 $\sigma$. Based on time-dependent synchrotron self-Compton (SSC) processes, the broad-band energy spectrum is interpreted as the emission from an electron energy distribution parameterized with a single power-law function with an exponential cutoff at its high energy end. The average spectral energy distribution for the steady emission is well described by this simple one-zone SSC model. However, the detection of $\gamma$-rays above 8 TeV during the flare challenges this model due to the hardness of the spectra. Correlations between X-rays and $\gamma$-rays are also investigated.Comment: have been accepted for publication at Ap

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

Contains fulltext : 121524.pdf (preprint version ) (Open Access

Search for Charged Higgs bosons: Combined Results Using LEP Data

The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for pair-produced charged Higgs bosons in the framework of Two Higgs Doublet Models (2HDMs). The data of the four experiments are statistically combined. The results are interpreted within the 2HDM for Type I and Type II benchmark scenarios. No statistically significant excess has been observed when compared to the Standard Model background prediction, and the combined LEP data exclude large regions of the model parameter space. Charged Higgs bosons with mass below 80 GeV/c^2 (Type II scenario) or 72.5 GeV/c^2 (Type I scenario, for pseudo-scalar masses above 12 GeV/c^2) are excluded at the 95% confidence level

L’attività dei Centri Antifumo italiani tra problematiche e aree da potenziare: i risultati di un’indagine svolta attraverso un questionario on-line

Introduzione. In Italia sono 295 i Servizi per la cessazione dal fumo di tabacco (Centri Antifumo - CA) afferenti al Servizio Sanitario Nazionale (SSN) censiti nel 2011 dall’Osservatorio Fumo, Alcol e Droga (OssFAD) dell’Istituto Superiore di Sanità. La presente indagine, condotta dall’OssFAD in collaborazione con i CA, è stata volta a rilevare alcune delle problematiche con le quali il personale dei CA si confronta per portare avanti la propria attività e le iniziative ritenute utili per migliorarla. Materiali e metodi. L’indagine è stata condotta dal 7 al 21 maggio 2012, mediante un questionario compilabile on-line composto da 5 brevi sezioni di domande con un totale di 38 items da completare. Il link al questionario on-line è stato inviato per e-mail a 322 indirizzi dei CA censiti nel 2011 dall’OssFAD. I dati raccolti sono stati elaborati statisticamente con il programma SPSS 20. Risultati. All’indagine hanno risposto 146 operatori dei CA (45,3%). Sebbene ci siano aspetti ormai consolidati dell’attività dei CA, sono ancora molte le criticità che gli operatori riscontrano nella loro attività. Le principali problematiche che influiscono in modo fondamentale/rilevante per la buona attività del centro sono le “Scarse o nulle risorse economiche” per il 60,7% del personale, “la mancanza di personale dedicato” per il 52,4% del personale; il “riconoscimento/mandato istituzionale del CA” per il 40,9% del personale. Tra le azioni ritenute più efficaci per facilitare l’accesso ai CA sono risultate la sensibilizzazione del personale sanitario (91%), in particolare dei medici di famiglia e l’inserimento delle prestazioni antitabagiche nei LEA (76,8%). Conclusioni. È auspicabile che l’attività dei CA riceva una maggiore attenzione, attraverso la dotazione di strutture, personale e finanziamenti adeguati a svolgere un importante ruolo nella tutela e promozione della salute

BEAM TESTS OF THE ZEUS BARREL CALORIMETER

A fully compensating uranium-scintillator calorimeter was constructed for the ZEUS detector at HERA. Several of the barrel calorimeter modules were subjected to beam tests at Fermilab before shipping them to DESY for installation. The calibrations of the modules used beams of electrons and hadrons, measuring the uniformity of the response, and checking the resolution. The runs also provided opportunity to test a large fraction of the actual ZEUS calorimeter readout system in an integrated beam environment more than one year before HERA turn on. The experiment utilized two computer controlled mechanical structures. one of which was capable of holding up to four modules in order to study shower containment, and a magnetic spectrometer with a high resolution beam tracking system. During two running periods, beams of 6 to 110 GeV containing e, mu, pi, and pBAR were used. The results show energy resolutions of 35%/square-root E for hadrons and 19%/square-root E for electrons, uniformities at the 1% level, energy nonlinearity less than 1%, and equal response for electrons and hadrons

Medium scale anisotropy in the TeV cosmic ray flux observed by ARGO-YBJ

Measuring the anisotropy of the arrival direction distribution of cosmic rays provides important information on the propagation mechanisms and the identification of their sources. In fact, the flux of cosmic rays is thought to be dependent on the arrival direction only due to the presence of nearby cosmic ray sources or particular magnetic-field structures. Recently, the observation of unexpected excesses at TeV energy down to an angular scale as narrow as raised the possibility that the problem of the origin of Galactic cosmic rays may be addressed by studying the anisotropy. The ARGO-YBJ experiment is a full-coverage extensive air showers array, sensitive to cosmic rays with the energy threshold of a few hundred GeV. Searching for small-size deviations from the isotropy, the ARGO-YBJ Collaboration explored the declination region , making use of about events collected from November 2007 to May 2012. In this paper, the detection of different significant (up to 13 standard deviations) medium-scale anisotropy regions in the arrival directions of cosmic rays is reported. The observation was performed with unprecedented detail. The relative excess intensity with respect to the isotropic flux extends up to . The maximum excess occurs for proton energies of 10–20 TeV, suggesting the presence of unknown features of the magnetic fields the charged cosmic rays propagate through, or some contribution of nearby sources never considered so far. The observation of new weaker few-degree excesses throughout the sky region is reported for the first time

OBSERVATION OF TeV GAMMA RAYS FROM THE UNIDENTIFIED SOURCE HESS J1841−055 WITH THE ARGO-YBJ EXPERIMENT

We report the observation of a very high energy γ -ray source whose position is coincident with HESS J1841−055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from 2007 November to 2012 July. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function, we estimate an extension σ = (0.40+0.32 −0.22)◦, which is consistent with the HESS measurement. The observed energy spectrum is dN/dE = (9.0 ± 1.6) × 10−13(E/5 TeV)−2.32±0.23 photons cm−2 s−1 TeV−1, in the energy range 0.9–50 TeV. The integral γ -ray flux above 1 TeV is 1.3 ± 0.4 Crab, which is 3.2 ± 1.0 times the flux derived by HESS. The differences in the flux determination between HESS and ARGO-YBJ and possible counterparts at other wavelengths are discussed