PulsarSpectrum: simulating gamma-ray pulsars for the GLAST mission

We present here an overview of PulsarSpectrum, a program that simulates the gamma ray emission from pulsars. This simulator reproduces not only the basic features of the observed gamma ray pulsars, but it can also simulate more detailed effects related to pulsar timing. It is a very useful tool to understand the GLAST capabilities in the pulsar science.Comment: 6 pages, 3 figures, contribution for "Third Workshop on Science with the New Generation of High Energy Gamma-ray Experiments", May 2005, Cividale del Friuli (UD), Ital

Quality of reporting on the vegetative state in Italian newspapers. The case of Eluana Englaro.

Background: Media coverage of the vegetative state (VS) includes refutations of the VS diagnosis and describes behaviors inconsistent with VS. We used a quality score to assess the reporting in articles describing the medical characteristics of VS in Italian newspapers. Methodology/Principal Findings: Our search covered a 7-month period from July 1, 2008, to February 28, 2009, using the online searchable databases of four major Italian newspapers: Corriere della Sera, La Repubblica, La Stampa, and Avvenire. Medical reporting was judged as complete if three core VS characteristics were described: patient unawareness of self and the environment, preserved wakefulness (eyes open), and spontaneous respiration (artificial ventilator not needed). We retrieved 2,099 articles, and 967 were dedicated to VS. Of these, 853 (88.2%) were non-medical and mainly focused on describing the political, legal, and ethical aspects of VS. Of the 114 (11.8%) medical articles, 53 (5.5%) discussed other medical problems such as death by dehydration, artificial nutrition, neuroimaging, brain death, or uterine hemorrhage, and 61 (6.3%) described VS. Of these 61, only 18 (1.9%) reported all three CORE characteristics and were judged complete. We found no differences among the four investigated newspapers (Fisher’s exact = 0.798), and incomplete articles were equally distributed between journalistic pieces and expert opinions (x2 = 1.8854, P = 0.170). Incorrect descriptions of VS were significantly more common among incomplete articles (13 of 43 vs. 1 of 18; Fisher’s exact P = 0.047). Conclusions/Significance: Core VS characteristics are rarely reported in Italian newspaper articles, which can alter adequate comprehension of new developments and (mis)inform political, legal, and ethical decisions

Reading a GEM with a VLSI pixel ASIC used as a direct charge collecting anode

In MicroPattern Gas Detectors (MPGD) when the pixel size is below 100 micron and the number of pixels is large (above 1000) it is virtually impossible to use the conventional PCB read-out approach to bring the signal charge from the individual pixel to the external electronics chain. For this reason a custom CMOS array of 2101 active pixels with 80 micron pitch, directly used as the charge collecting anode of a GEM amplifying structure, has been developed and built. Each charge collecting pad, hexagonally shaped, realized using the top metal layer of a deep submicron VLSI technology is individually connected to a full electronics chain (pre-amplifier, shaping-amplifier, sample and hold, multiplexer) which is built immediately below it by using the remaining five active layers. The GEM and the drift electrode window are assembled directly over the chip so the ASIC itself becomes the pixelized anode of a MicroPattern Gas Detector. With this approach, for the first time, gas detectors have reached the level of integration and resolution typical of solid state pixel detectors. Results from the first tests of this new read-out concept are presented. An Astronomical X-Ray Polarimetry application is also discussed.Comment: 11 pages, 14 figures, presented at the Xth Vienna Conference on Instrumentation (Vienna, February 16-21 2004). For a higher resolution paper contact [email protected]

The Micro-Groove Detector

We introduce the Micro-Groove Detector (MGD), a new type of position-sensitive gas proportional counter produced using advanced printed circuit board (PCB) technology. The MGD is based on a thin kapt on foil, clad with gold-plated copper on both sides. An array of micro-strips at a typical pitch of 200um is defined on the top metal layer. Using as a protection mask the metal left after the patter ning, charge amplifying micro-grooves are etched into the kapton layer. These end on a second micro-strip pattern which is defined on the bottom metal plane. The two arrays of micro-strips can have a n arbitrary relative orientation and so can be used for read-out to obtain 2-D positional information. First results from our systematic assessment of this device are reported: gas gain > 15000, rat e capability above 10^6mm-2s-1, energy resolution 22% at 5.4 keV, no significant charging or aging effects up to 5mC/cm, full primary charge collection efficiency even at high drift fields

The WELL Detector

We introduce the WELL detector, a new type of position-sensitive gas proportional counter produced using advanced printed circuit board (PCB) technology. The WELL is based on a thin kapton foil, copp erclad on both sides. Charge amplifying micro-wells are etched into the first metal and kapton layers. These end on a micro-strip pattern which is defined on the second metal plane. The array of micr o-strips is used for read-out to obtain 1-D positional information. First results from our systematic assessment of this device are reported

Brain death as a moral definition and an act of love: The tale of Moon, Nehviel and Fate

The vital status of people with a destroyed brain is one of the most discussed topics in medical literature. According to the current legal narrative, people whose brain is destroyed are dead. Nevertheless, a clear biological rationale to support with certainty such a narrative is still lacking. The purported rationale of the “the brain as the central integrator of the body” has proven to be biologically untenable. Persons with a destroyed brain can be maintained viable for long periods of time, showing clear signs of good biological integration. This fact stirs up a continuous seething of heated discussions among scholars, and generates uncertainty among lay people, loss of trust towards the medical community, and highly controversial cases in the media. To try to settle this unresolved situation, we propose a moral narrative, according to which people whose brain is destroyed should be considered as dead. Defining those people as biologically dead is impossible. Their clinical condition is neither life nor death; it is something in between, an artifice created by modern medicine. Yet, we can well state that the irreversible loss of all brain functions is a clinically and scientifically useful point of no return in the process of dying which can guide sound decisions. Through a personal reinterpretation of the myth of Orpheus and Eurydice, we would like to show that the choice to consider people with a destroyed brain as dead is a sound moral decision and an act of love

Low energy polarization sensitivity of the Gas Pixel Detector

An X-ray photoelectric polarimeter based on the Gas Pixel Detector has been proposed to be included in many upcoming space missions to fill the gap of about 30 years from the first (and to date only) positive measurement of polarized X-ray emission from an astrophysical source. The estimated sensitivity of the current prototype peaks at an energy of about 3 keV, but the lack of readily available polarized sources in this energy range has prevented the measurement of detector polarimetric performances. In this paper we present the measurement of the Gas Pixel Detector polarimetric sensitivity at energies of a few keV and the new, light, compact and transportable polarized source that was devised and built to this aim. Polarized photons are produced, from unpolarized radiation generated with an X-ray tube, by means of Bragg diffraction at nearly 45 degrees. The employment of mosaic graphite and flat aluminum crystals allow the production of nearly completely polarized photons at 2.6, 3.7 and 5.2 keV from the diffraction of unpolarized continuum or line emission. The measured modulation factor of the Gas Pixel Detector at these energies is in good agreement with the estimates derived from a Monte Carlo software, which was up to now employed for driving the development of the instrument and for estimating its low energy sensitivity. In this paper we present the excellent polarimetric performance of the Gas Pixel Detector at energies where the peak sensitivity is expected. These measurements not only support our previous claims of high sensitivity but confirm the feasibility of astrophysical X-ray photoelectric polarimetry.Comment: 15 pages, 12 figures. Accepted for publication in NIM