The High Energy Cosmic Radiation Detection (HERD) facility onboard the future China's Space Station (CSS) will provide high quality data on charged cosmic rays and gamma rays reaching the measured ...range from few GeV to PeV energies. Because of this capability, HERD experiment would give a valuable contribution in several scientific topics as dark matter searches, study of cosmic ray chemical composition and high energy gamma-ray observations. HERD will be equipped with a deep 3D cubic calorimeter surrounded by a microstrip Si tracker detector. The entire instrument will be surrounded by a plastic scintillator detector (PSD). The PSD will be used to discriminate charged from neutral particles in order to correctly identify gamma-rays and nuclei. One configuration proposed and studied for the HERD PSD detector the geometry of scintillator segmented in tiles coupled to Silicon Photomultipliers (SiPMs). SiPMs provide similar or even better performances to the standard photomultiplier tubes (PMTs) with lower power consumption and cost benefits. In 2018, beam test campaigns were performed at CERN SPS with ion beam to study the scintillator response with a SiPM-based readout and to test the capability of the PSD to discriminate the ion charges. The results will be presented.
Galaxy clusters are expected to be dark matter (DM) reservoirs and storage
rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's
formation history. Accordingly, they are ...excellent targets to search for
signals of DM annihilation and decay at gamma-ray energies and are predicted to
be sources of large-scale gamma-ray emission due to hadronic interactions in
the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope
Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy
cluster. We perform a detailed spatial and spectral modelling of the expected
signal for the DM and the CRp components. For each, we compute the expected CTA
sensitivity. The observing strategy of Perseus is also discussed. In the
absence of a diffuse signal (non-detection), CTA should constrain the CRp to
thermal energy ratio within the radius $R_{500}$ down to about $X_{500}<3\times
10^{-3}$, for a spatial CRp distribution that follows the thermal gas and a CRp
spectral index $\alpha_{\rm CRp}=2.3$. Under the optimistic assumption of a
pure hadronic origin of the Perseus radio mini-halo and depending on the
assumed magnetic field profile, CTA should measure $\alpha_{\rm CRp}$ down to
about $\Delta\alpha_{\rm CRp}\simeq 0.1$ and the CRp spatial distribution with
10% precision. Regarding DM, CTA should improve the current ground-based
gamma-ray DM limits from clusters observations on the velocity-averaged
annihilation cross-section by a factor of up to $\sim 5$, depending on the
modelling of DM halo substructure. In the case of decay of DM particles, CTA
will explore a new region of the parameter space, reaching models with
$\tau_{\chi}>10^{27}$s for DM masses above 1 TeV. These constraints will
provide unprecedented sensitivity to the physics of both CRp acceleration and
transport at cluster scale and to TeV DM particle models, especially in the
decay scenario.
To assess the efficacy of an interdisciplinary protocol for treating obesity in a group of patients with BMI > or = 35 and with altered respiratory function that was not necessarily related to ...obesity or not.
Forty obese individuals between 18 and 60 years of age with altered respiratory function were enrolled. Spirometric values, plethysmograph volumes, arterial blood gases, and nighttime respiratory polygraphs were recorded. Following psychological and nutritional evaluation, the patients commenced year-long treatment for obesity involving a personalized diet and psychological counseling. Follow-up was weekly and individualized at first; in later sessions, patients were grouped. Lung function tests were repeated after loss of 5 kg. Sleep polygraphy was repeated after loss of 10 kg.
Weight loss over 15 kg was achieved by 48.6% of the patients. Respiratory function variables: FVC, FEV1, RV, ERV, PaO2 and SatO2 after treatment changed significantly from initial levels. Significant differences were also seen in the severity of sleep apnea and pressures needed for continuous positive airway pressure. Uric acid, glucose and triglyceride blood levels became normal in 89%, 61% and 50% of the patients, respectively, after weight loss. No characteristic psychological profile was identified for severe obesity, although levels of anxiety, eating behavior, marital adjustment and perception of body image were aspects that were fundamentally altered.
In the difficult group of obese patients with BMI > or = 35, interdisciplinary treatment has proven effective for achieving substantial weight loss, while improving respiratory function and severity of sleep disorder. This therapy, which is at present viable for few centers, deserves consideration in the interest of benefiting the increasing number of obese patients.
GRB 131108A is a bright long gamma-ray burst (GRB) detected by the Large Area Telescope and the Gamma-rayBurst Monitor on board the Fermi Gamma-ray Space Telescope. Dedicated temporal and spectral ...analyses revealthree γ-ray flares dominating above 100 MeV, which are not directly related to the prompt emission in the GammarayBurst Monitor band (10 keV–10 MeV). The high-energy light curve of GRB 131108A (100 MeV–10 GeV)shows an unusual evolution: a steep decay, followed by three flares with an underlying emission, and then a longlastingdecay phase. The detailed analysis of the γ-ray flares finds that the three flares are 6–20 times brighter thanthe underlying emission and are similar to each other. The fluence of each flare, (1.6∼2.0)×10−6 erg cm−2, iscomparable to that of emission during the steep decay phase, 1.7×10−6 erg cm−2. The total fluence from threeγ-ray flares is 5.3×10−6 erg cm−2. The three γ-ray flares show properties similar to the usual X-ray flares thatare sharp flux increases, occurring in ∼50% of afterglows, in some cases well after the prompt emission. Also, thetemporal and spectral indices during the early steep decay phase and the decaying phase of each flare show theconsistency with a relation of the curvature effect (aˆ =2 + bˆ ), which is the first observational evidence ofthe high-latitude emission in the GeV energy band.
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