A Study on anisotropy of cosmic ray distribution with a small array of water-cherenkov detectors

The study of the anisotropy of the arrival directions is an essential tool to investigate the origin and propagation of cosmic rays primaries. A simple way of recording many cosmic rays is to record coincidences between a number of detectors. We have monitored multi-TeV cosmic rays by a small array of water cherenkov detectors in Tehran(35 43 N, 51 20 E, 1200m a.s.l). More than 1.1*10^6 extensive air shower events were recorded. In addition to the Compton- Getting effect due to the motion of the earth in the Galaxy, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms.Comment: 16 pages 9 figs and one tabl

Determination of HCV genotypes, in Iran by PCR-RFLP

Hepatitis C is a major cause of liver related morbidity and mortality worldwide and represents a major public health problem. Depending on genomic organization, the virus is divided into six genotypes and a number of subtypes. Different genotypes are seen in different parts of the world. Genotype one is difficult to treat, while genotypes 2 and 3 are easy to treat. Therefore, identification of HCV genotype in patients is necessary to begin and follow up the treatment. In this study, viral genomic materials of 214 patients' sera were detected by nested-RT PCR. Based on genomic differences among different genotypes, the PCR products were digested with proper enzymes and studied by RFLP. Except for one, sequencing of 1 samples, representative of all genotypes, confirmed the results of PCR-RFLP. The results of PCR-RFLP were as follows: 1a (52.88), 1b (14.01), 3a (27.57), 2a (2.1), 4 (3.44). This indicates that a high percentage of HCV infected patients in Iran are infected with 1a or 3a genotypes. These findings reveal that the pattern of HCV genotypes in Iran differs from those of other middle-eastern countries

Efficacy of tenofovir disoproxil fumarate therapy in nucleoside-analogue naive Iranian patients treated for chronic hepatitis B

Background: Tenofovir disoproxil fumarate (TDF) is a new effective treatment option for patients with chronic hepatitis B (CHB). Objectives: To evaluate TDF efficacy in nucleos(t)ide analogues (NAs)-naive Iranian patients with CHB. Patients and Methods: The NA-naive patients received TDF for at least six months. The primary endpoint was the proportion of patients achieving a complete virological response (CVR) during the treatment. Multivariate Cox regression analysis determined predictive factors independently associated with the time to CVR. The secondary endpoints were biochemical and serological responses, frequency of virological breakthrough, genotypic resistance development, safety and tolerability. Results: In all, 93 patients (64.5 hepatitis B e antigen HBeAg-negative) were eligible. Of these, 70 patients completed 24 months of treatment. The cumulative CVR rates in HBeAg-negative and HBeAg-positive patients were 87% versus 53% at 24 months, respectively. The multivariate Cox regression model showed only HBeAg positivity at baseline and a high baseline HBV DNA level were independent factors predicting a CVR. No patient achieved hepatitis B surface antigen (HBsAg) and HBeAg loss or seroconversion and no virologic breakthrough occurred. A new amino acid substitution (rtD263E) was observed to develop in 60% of patients with viremia. Conclusions: The cumulative CVR rates showed that patients with HBeAg-negative have better virologic respond than those with HBeAg-positive during the same period. The rtD263E mutation might be associated with partial resistance to TDF. © 2015, Kowsar Corp

The Pierre Auger Observatory III: Other Astrophysical Observations

Astrophysical observations of ultra-high-energy cosmic rays with the Pierre Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference, Beijing, China, August 201

An All-Sky Search for Three Flavors of Neutrinos from Gamma-Ray Bursts with the IceCube Neutrino Observatory

We present the results and methodology of a search for neutrinos produced in the decay of charged pions created in interactions between protons and gamma-rays during the prompt emission of 807 gamma-ray bursts (GRBs) over the entire sky. This three-year search is the first in IceCube for shower-like Cherenkov light patterns from electron, muon, and tau neutrinos correlated with GRBs. We detect five low-significance events correlated with five GRBs. These events are consistent with the background expectation from atmospheric muons and neutrinos. The results of this search in combination with those of IceCube's four years of searches for track-like Cherenkov light patterns from muon neutrinos correlated with Northern-Hemisphere GRBs produce limits that tightly constrain current models of neutrino and ultra high energy cosmic ray production in GRB fireballs.Comment: 33 pages, 14 figures; minor changes made to match published version in the Astrophysical Journal, 2016 June 2

The IceCube Neutrino Observatory: Instrumentation and Online Systems

The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review and proofin

Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry

We present an improved event-level likelihood formalism for including neutrino telescope data in global fits to new physics. We derive limits on spin-dependent dark matter-proton scattering by employing the new formalism in a re-analysis of data from the 79-string IceCube search for dark matter annihilation in the Sun, including explicit energy information for each event. The new analysis excludes a number of models in the weak-scale minimal supersymmetric standard model (MSSM) for the first time. This work is accompanied by the public release of the 79-string IceCube data, as well as an associated computer code for applying the new likelihood to arbitrary dark matter models.Comment: 24 pages, 8 figs, 1 table. Contact authors: Pat Scott & Matthias Danninger. Likelihood tool available at http://nulike.hepforge.org. v2: small updates to address JCAP referee repor

Lowering IceCube’s energy threshold for point source searches in the southern sky

Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current nu(mu) interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (similar to 100 TeV) starting event in the sample found that this event alone represents a 2.8 sigma deviation from the hypothesis that the data consists only of atmospheric background

The IceCube Neutrino Observatory - Contributions to ICRC 2015 Part II: Atmospheric and Astrophysical Diffuse Neutrino Searches of All Flavors

Papers on atmospheric and astrophysical diffuse neutrino searches of all flavors submitted to the 34th International Cosmic Ray Conference (ICRC 2015, The Hague) by the IceCube Collaboration.Comment: 66 pages, 36 figures, Papers submitted to the 34th International Cosmic Ray Conference, The Hague 2015, v2 has a corrected author lis