The First VERITAS Telescope

The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description of the instrument and a summary of its performance. The calibration methods are described, along with the results of Monte Carlo simulations of the telescope and comparisons between real and simulated data. The analysis of TeV $\gamma$-ray observations of the Crab Nebula, including the reconstructed energy spectrum, is shown to give results consistent with earlier measurements. The telescope is operating as expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic

Pengaruh Pemberian Ketotifen terhadap Jumlah Sel Fibroblas dan Kepadatan Sel Kolagen pada Luka Insisi Tikus Wistar

Ingga Hadian, S-501202027. PENGARUH PEMBERIAN KETOTIFEN TERHADAP JUMLAH SEL FIBROBLAS DAN KEPADATAN SEL KOLAGEN PADA LUKA INSISI TIKUS WISTAR. Pembimbing I : DR. Untung Alfianto, dr, Sp.Bs, Pembimbing II : dr. Ardana Tri Arianto. Msi. Med. Sp.An-KNA. Program studi Magister Kedokteran Keluarga, Minat Utama Ilmu Biomedik, Fakultas Kedokteran Universitas Sebelas Maret, Surakarta, 2016. Latar Belakang : Sel mast merupakan salah satu yang berperan dalam proses inflamasi pada penyembuhan luka. Sel mast dikaitkan dengan kejadian luka kronis, sehingga sel mast diduga ikut memelihara proses inflamasi secara berlebihan. Hambatan pada degranulasi sel mast diharapkan akan mempercepat penyembuhan luka yang ditandai dengan meningkatnya jumlah sel fibroblas dan kepadatan sel kolagen. Ketotifen mampu mengurangi dreganulasi sel Mast dan mengurangi pelepasan Histamin, protease sel Mast, myeloperoxidase, leukotriens, PAF dan bermacam-macam Prostaglandin. Ketotifen juga menghambat agregasi polimorfonuklear serta mengurangi respon inflamasi dan mempercepat migrasi fibroblas di fase proliferasi. Tujuan :Mengetahui perbedaan jumlah sel fibroblas dan kepadatan sel kolagen pada tikus wistar yang diberikan Ketotifen oral dosis 0.3 mg/kg dibandingkan plasebo pada penyembuhan luka insisi tikus wistar. Metode : Penelitian ini termasuk true eksperimental laboratorik dengan desain Randomized Controlled Trial yang menggunakan tikus wistar sebagai obyek penelitian. 14 tikus Wistar dibagi dalam 2 kelompok, masing masing kelompok terdiri atas 7 tikus Wistar. Kelompok 1 merupakan kelompok kontrol yang dilakukan insisi sepanjang 2cm pada kulit punggung tikus dan diberikan plasebo per oral selama 6 hari. Kelompok 2 merupakan kelompok perlakuan yang dilakukan insisi sepanjang 2cm pada kulit punggung tikus dan diberikan Ketotifen 0,3 mg/kgBB per oral setiap 12 jam selama 6 hari. Analisis data untuk membandingkan rerata antar kedua kelompok yaitu kelompok perlakuan dan kelompok kontrol menggunakan uji independent samples t-test, dengan tingkat kemaknaan p < 0,05 (dikatakan bermakna secara statistik). Hasil : Pada kelompok kontrol didapatkan rerata persentase kepadatan sel kolagen sebesar 26,05 %, sedangkan pada kelompok Ketotifen didapatkan rerata persentase kepadatan sel kolagen sebesar 36,13 %. Untuk jumlah sel fibroblas pada kelompok kontrol didapatkan rerata sebesar 423 per lapang pandang, sedangkan pada kelompok Ketotifen didapatkan rerata sebesar 555,43 per lapang pandang. Kesimpulan : Ketotifen mempercepat penyembuhan luka ditandai dengan peningkatan sel fibroblas dan sel kolagen. Kata Kunci : Sel Mast, Ketotifen, Sel fibroblas, Serabut Kolagen. ABSTRACT Ingga Hadian, S-501202027. EFFECTS OF KETOTIFEN ON FIBROBLAST CELL COUNT AND COLLAGEN DENSITY ON INCISED WISTAR RATS. DR. Untung Alfianto, dr., Sp.BS, dr. Ardana Tri Arianto, Msi, Med, Sp.An-KNA. Background: Mast cells have a pivotal role in every healing process that involves inflammation of the cells, usually in wounds of chronic nature. If the degranulation process of the mast cells are inhibited, the healing process of the wound will accelerate, indicated by a raise in fibroblast cells and collagen density. Ketotifen are shown to inhibit the degranulation process and decreasing the release of histamin, mast cells proteases, myeloperoxidases, leukotriens, PAF, and various prostaglandins. Ketotifen can also inhibit the aggregation of polymorphonuclear cells, increasing the rate of fibroblast migration in the proliferation phase. This study was aimed to identify the effects of ketotifen on fibroblast cell count and collagen density tested on a wistar rats model. Methods: This study was a true laboratoric experimental study with randomized controlled trial using wistar rats model as objects. 14 rats were divided into two groups, each group contained seven rats. The first group was the control group, where the rats were incised 2 cm above the back skin, and were given per oral placebo for 6 days. The second group were given the same treatment, only the rats were given ketotifen 0.3 mg/kg per oral, every 12 hours lasting 6 days. The data were then collected and tested with independent sample t-test, with p value less than 0,05 is statistically significant. Results: In the control group, the mean percentage of the thickest collagen density were marked at 26.05%, whereas in the treatment group collagen density were marked at 36.13%. The mean fibroblast cell count were marked at 423 and 555.43 each viewing field, on the control group and the treatment group respectively. Conclusion: Ketotifen can accelerate the healing process, marked by the significant increase in collagen density and fibroblast cell count. Keywords: mast cells, ketotifen, fibroblast cells, collagen fibers

Multiwavelength observations of a TeV-Flare from W comae

We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z = 0.102) during a strong outburst of very high energy gamma-ray emission in 2008 June. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) =(5.7 0.6) × 10-11 cm-2 s -1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high-energy gamma rays (AGILE; E γ≥ 100 MeV), X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution of the source from contemporaneous data taken throughout the flare. © 2009. The American Astronomical Society. All rights reserved

Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society

Boron isotopes in Central American volcanics indicate a key role for the subducting oceanic crust

The geochemistry of arc magmas can shed light on chemical outfluxes from subducting slabs to the overlying mantle. Boron (B) abundances and isotope ratios are valuable tracers of slab-derived components due to the distinct compositions of the mantle and subducting materials and distinctive isotopic fractionation during dehydration. New Be/B and δ11B measurements in olivine-hosted melt inclusions (MIs) from three Nicaraguan volcanic centers (Telica, Cerro Negro, and Masaya) are consistent with a B-rich slab component that has δ11B ranging from +2.9‰ to +5.9‰, slightly higher than new measurements of hemipelagic (δ11B = +0.7‰±0.03 and +2.1‰±0.08; 1σ n = 3) and carbonate (δ11B = +2.9‰±0.06 and 3.7±0.09; 1σ n = 3) sediments sampled by DSDP Hole 495 on the Cocos plate. A thermochemical model of the Nicaraguan subduction zone is used to quantitatively model B loss and isotopic fractionation during slab dehydration and melting. In contrast to previous studies regarding B systematics in Central America and elsewhere, this model reproduces the range of δ11B preserved in Nicaraguan olivine-hosted MIs without the involvement of serpentinite-derived fluids. The model indicates that Nicaraguan MI δ11B signatures are primarily controlled by input from subducted altered oceanic crust (AOC), with a minor contribution from subducted sediments. This finding implies that the volatile element budget delivered from the slab to the volcanic arc is also mostly derived from the ocean crust, and that volatiles carried in deeper layers of the slab may be recycled beyond the arc into the deeper mantle beneath Central America

ELEVATED ALANINE AMINOTRANSFERASE (ALT) IN BLOOD DONORS: AN ASSESSMENT OF THE MAIN ASSOCIATED CONDITIONS AND ITS RELATIONSHIP TO THE DEVELOPMENT OF HEPATITIS C

The determination of aminotranferases levels is very useful in the diagnosis of hepatopathies. In recent years, an elevated serum ALT level in blood donors has been associated with an increased risk of post-transfusion hepatitis (PTH). The purpose of the study was to research the factors associated with elevated ALT levels in a cohort of voluntary blood donors and to evaluate the relationship between increased ALT levels and the development of hepatitis C (HCV) infection. 166 volunteer blood donors with elevated ALT at the time of their first donation were studied. All of the donors were questioned about previous hepatopathies, exposure to hepatitis, exposure to chemicals, use of medication or drugs, sexual behaviour, contact with blood or secretions and their intake of alcohol. Every three months, the serum levels of AST, ALT, alkaline phosphatase, gamma glutamyl transpeptidase, cholesterol, triglyceride and glycemia are assessed over a two year follow-up. The serum thyroid hormone levels as well as the presence of auto-antibodies were also measured. Abdominal ultrasound was performed in all patients with persistently elevated ALT or AST levels. A needle biopsy of liver was performed in 9 donors without definite diagnostic after medical investigation. The presence of anti-HCV antibodies in 116 donors were assayed again the first clinical evaluation. At the end of follow-up period (2 years later) 71 donors were tested again for the presence of anti-HCV antibodies. None of donors resulted positive for hepatitis B or hepatitis C markers during the follow-up. Of the 116 donors, 101 (87%) had persistently elevated ALT serum levels during the follow-up. Obesity and alcoholism were the principal conditions related to elevated ALT serum levels in 91/101 (90.1%) donors. Hypertriglyceridemia, hypercholesterolemia, hypothyroidism and diabetes mellitus also were associated with increased ALT levels. Only 1/101 (0.9%) had mild chronic active non A-G viral hepatitis and 3/101 (2.9%) had liver biopsy with non-specific reactive hepatitis. The determination of ALT levels was not useful to detect donors infected with HCV at donation in Brazil, including the initial seronegative anti-HCV phase.<br>A determinação dos níveis de alanina aminostransferase (ALT) tem sido útil para o diagnóstico de hepatopatias. Ultimamente, a elevação dos níveis séricos de ALT em doadores de sangue, tem sido associada a um maior risco de hepatites pós-transfusionais. Este estudo busca identificar os fatores associados com elevados níveis de ALT entre doadores voluntários de sangue e avaliar as relações entre estes aumentos de ALT e o desenvolvimento de infecção pelo vírus da hepatite C. Assim, 116 doadores voluntários de sangue com níveis de ALT elevados, quando da primeira doação, foram estudados. Todos foram questionados sobre hepatopatias prévias, exposição a hepatites, exposição a produtos químicos, uso de drogas ou medicamentos, comportamento sexual, contacto com sangue ou secreções e consumo de álcool. A cada 3 meses foram medidos os níveis de AST, ALT, fosfatase alcalina, gama-glutamil transferase, colesterol, triglicérides e glicemia durante o período de 1-2 anos. Os níveis séricos de hormônios tireoidianos e a presença de auto-anticorpos também foram mensurados. Ultrassonografia abdominal foi realizada em todos os pacientes com elevação persistente dos níveis de AST ou ALT. Foi realizada biópsia hepática em 9 doadores sem diagnóstico definido após investigação clínica. A presença de anticorpos anti-HCV foi novamente pesquisada em 116 doadores no momento da primeira avaliação clínica. Ao final do follow-up (2 anos) 71 doadores foram re-testados para a presença do anti-HCV. Nenhum doador se tornou reagente para os marcadores dos virus da hepatite B ou hepatite C, durante o seguimento. Dos 116 doadores, 101 (87%) mantiveram níveis séricos de ALT persistentemente aumentados. Obesidade e alcoolismo foram as principais condições associadas à elevação dos níveis séricos de ALT em 91/101 (90,1%) doadores. Hipertrigliceridemia, hipercolesterolemia, hipotireoidismo e diabetes mellitus também se associaram a níveis aumentados de ALT. Somente 1/101 (0,9%) apresentou hepatite crônica ativa não A-G e 3/101 (2,9%) apresentaram biópsia hepática com diagnóstico de hepatite reacional. A determinação rotineira dos níveis de ALT, em bancos de sangue não foi útil para detectar doadores infectados com o vírus da hepatite C no Brasil no período que antecede a soroconversão para anti-vhc

X-ray polarimetry with the Polarization Spectroscopic Telescope Array (PolSTAR)

This paper describes the Polarization Spectroscopic Telescope Array (PolSTAR), a mission proposed to NASA’s 2014 Small Explorer (SMEX) announcement of opportunity. PolSTAR measures the linear polarization of 3–50 keV (requirement; goal: 2.5–70 keV) X-rays probing the behavior of matter, radiation and the very fabric of spacetime under the extreme conditions close to the event horizons of black holes, as well as in and around magnetars and neutron stars. The PolSTAR design is based on the technology developed for the Nuclear Spectroscopic Telescope Array (NuSTAR) mission launched in June 2012. In particular, it uses the same X-ray optics, extendable telescope boom, optical bench, and CdZnTe detectors as NuSTAR. The mission has the sensitivity to measure ∼1% linear polarization fractions for X-ray sources with fluxes down to ∼5 mCrab. This paper describes the PolSTAR design as well as the science drivers and the potential science return