39 research outputs found
Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV equivalent to 10^(18) eV). Despite the flux of these particles being extremely low, the area of similar to 3000 km^(2) covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultra-high-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of 122,000 km^(2) sr yr, and search it for anisotropies over the 3.4 pi steradians covered with the Observatory. Evidence for a deviation in excess of isotropy at intermediate angular scales, with similar to 15 degrees Gaussian spread or similar to 25 degrees top-hat radius, is obtained at the 4 sigma significance level for cosmic-ray energies above similar to 40 EeV
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
FATTY ACID SYNTHASE IS A MARKER OF INCREASED RISK OF RECURRENCE IN ENDOMETRIAL CARCINOMA
.Purpose. To explore the expression of fatty acid synthase (FAS) and human erythrocyte glucose transporter 1 (GLUT1) in endometrial carcinomas and to detect associations with clinicopathological features and prognosis. FAS and GLUT1 are two molecules involved in energy supply of normal cells. These markers are overexpressed in neoplastic tissues because of their increased necessity of energy. Methods. Ninety-five patients with endometrial carcinoma were followed-up for an average period of 5 years. FAS and GLUT1 expressions were evaluated by immunohistochemistry on formalin-fixed paraffin-embedded tissues. Staining was determined with a semiquantitative method. Negative controls were obtained from patients submitted to hysterectomy for uterine prolapse. Results. Eighty-five cases were endometrioid, 7 were serous, and 1 was a mucinous carcinoma. Seventy-two cases (75%) were stage I, 12 (13%) were stage II, and 11 (12%) were stage III carcinomas. Sixteen (15%) carcinomas recurred. Nine patients (8%) died for cancer during the follow-up period. FAS expression was observed in 53 cases (56%). GLUT1 expression was observed in 32 (43%) cases. Statistical analysis revealed that FAS ( P = 0.04) and stage ( P = 0.001) of the disease were the only two independent predictors of recurrence. GLUT1 and other clinicopathologic parameters had no prognostic association. Conclusions. FAS is a reliable marker of clinically aggressive endometrial carcinomas. The knowledge of FAS expression in endometrial carcinomas is an important finding that may stratify patients into selected groups and determine therapeutic approaches for patient care