1,493 research outputs found
Linux Based Ethernet Communication for Xilinx FPGAs
This article presents the implementation of an Ethernet communication platform for use on Xilinx FPGAs. The proposed solution relies on a synthesized embedded system to provide network data transfer and control capabilities, for use with synthesizable electronic devices. Most TCP/IP stack services and protocols were implemented and the design is flexible to allow adaptation and/or expansion for different application scenarios. Currently this platform is being used on the development of a FPGA based JTAG controller, with remote access. The embedded system hardware requires a MicroBlaze softcore microprocessor running a Petalinux operating system.info:eu-repo/semantics/publishedVersio
Case report: Fulminant pneumococcal sepsis in an unvaccinated asplenic patient in Italy
We report a fatal case of overwhelming pneumococcal infection in an asplenic young adult not vaccinated against Streptococcus pneumoniae (S. pneumoniae). Post-mortem microbiological investigations revealed the presence of S. pneumoniae in blood samples and lungs. Serotyping by molecular methods identified the presence of a 6C serotype not comprised in the current 23-valent pneumococcal vaccine, highlighting that a risk of fatal infections may persist even in vaccinated splenectomised individuals
HIV awareness: A kap study among students in Italy reveals that preventive campaigns still represent a public health priority
Background. Improving knowledge about HIV/AIDS among young people is crucial for preventing new infections. The aim of the study was to investigate knowledge, attitudes and practices regarding HIV infection among students attending university courses related to the healthcare professions, in order to better target future preventive and informative HIV campaigns tailored for young people. Study Design. A knowledge, attitude and practices study was conducted among university students attending the following university courses in Bari (Southern Italy): Medicine and Surgery (MS), Dentistry and Dental Prostheses, Health Assistance, Motor Activities and Sports Sciences, Sciences and Technology of Herbal and Health Products, Nursing, Biomedical Laboratory Techniques, and Dietetics. Methods. Students completed a self-administered questionnaire designed to assess their knowledge/attitudes re/ HIV and their own sexual practices. The general part of the questionnaire requested information about age, gender, nationality, religion and marital status. The second part included questions asking about knowledge, attitude and practices with respect to HIV, which required true/false answers or graduated answers (reported as agree, quite agree, quite disagree, and disagree). Results. Four hundred students were invited to fill in the questionnaire. The response rate was 91.2% (n=365). Almost all students were aware that HIV is transmitted through sexual intercourse and blood, but only 34% knew that breastfeeding is a route of transmission. Of the respondents, 86.8% referred to previous sexual intercourse (25.8% reported using a condom in all cases of sexual intercourse, 43.5% in most cases, 18.6% rarely and 12.1 never). Sexual intercourse with casual partners was reported by 37.5% of these students and 63.9% of them did not always use a condom. Conclusions. The results of the study show that knowledge about some aspects of HIV is insufficient even though the students participating in the present study are students attending university courses related to the healthcare professions. Moreover, high-risk behaviors as the lack of the use of condom during sexual intercourse with casual partners are also common among interviewed students. Programs aimed at providing information that can prevent/reduce transmission of HIV in young people and new strategies to improve knowledge should be stressed as a public health priority
Fresh Activity in Old Systems: Radio AGN in Fossil Groups of Galaxies
We present the first systematic 1.4 GHz Very Large Array radio continuum
survey of fossil galaxy group candidates. These are virialized systems believed
to have assembled over a gigayear in the past through the merging of galaxy
group members into a single, isolated, massive elliptical galaxy and featuring
an extended hot X-ray halo. We use new photometric and spectroscopic data from
SDSS Data Release 7 to determine that three of the candidates are clearly not
fossil groups. Of the remaining 30 candidates, 67% contain a radio-loud
(L_1.4GHz > 10^23 W Hz^-1) active galactic nucleus (AGN) at the center of their
dominant elliptical galaxy. We find a weak correlation between the radio
luminosity of the AGN and the X-ray luminosity of the halo suggesting that the
AGN contributes to energy deposition into the intragroup medium. We only find a
correlation between the radio and optical luminosity of the central elliptical
galaxy when we include X-ray selected, elliptically dominated non-fossil
groups, indicating a weak relationship between AGN strength and the mass
assembly history of the groups. The dominant elliptical galaxy of fossil groups
is on average roughly an order of magnitude more luminous than normal group
elliptical galaxies in optical, X-ray, and radio luminosities and our findings
are consistent with previous results that the radio-loud fraction in elliptical
galaxies is linked to the stellar mass of a population. The current level of
activity in fossil groups suggests that AGN fueling continues long after the
last major merger. We discuss several possibilities for fueling the AGN at the
present epoch.Comment: Accepted for publication in A
Minkowski's Object: A Starburst Triggered by a Radio Jet, Revisited
We present neutral hydrogen, ultraviolet, optical and near-infrared imaging,
and optical spectroscopy, of Minkowski's Object (MO), a star forming peculiar
galaxy near NGC 541. The observations strengthen evidence that star formation
in MO was triggered by the radio jet from NGC 541. Key new results are the
discovery of a 4.9E8 solar mass double HI cloud straddling the radio jet
downstream from MO, where the jet changes direction and decollimates; strong
detections of MO, also showing double structure, in UV and H-alpha; and
numerous HII regions and associated clusters in MO. In UV, MO resembles the
radio-aligned, rest-frame UV morphologies in many high redshift radio galaxies
(HzRGs), also thought to be caused by jet-induced star formation. MO's stellar
population is dominated by a 7.5 Myr-old, 1.9E7 solar mass instantaneous burst,
with current star formation rate 0.52 solar masses per year (concentrated
upstream from where the HI column density is high). This is unlike the
jet-induced star formation in Centaurus A, where the jet interacts with
pre-existing cold gas; in MO the HI may have cooled out of a warmer, clumpy
intergalactic or interstellar medium as a result of jet interaction, followed
by collapse of the cooling clouds and subsequent star formation (consistent
with numerical simulations). Since the radio source that triggered star
formation in MO is much less luminous, and therefore more common, than powerful
HzRGs, and because the environment around MO is not particularly special in
terms of abundant dense, cold gas, jet-induced star formation in the early
universe might be even more prevalent than previously thought.Comment: 52 pages, 15 figures, accepted for publication in Ap
The Extinction and Distance of Maffei 1
We have obtained low- and high-resolution spectra of the core of the
highly-reddened elliptical galaxy Maffei 1. From these data, we have obtained
the first measurement of the Mg2 index, and have measured the velocity
dispersion and radial velocity with improved accuracy. To evaluate the
extinction, a correlation between the Mg2 index and effective V-I colour has
been established for elliptical galaxies. Using a new method for correcting for
effective wavelength shifts, we find A_V = 4.67 +/- 0.19 mag, which is lower by
0.4 mag than previously thought. To establish the distance, the Fundamental
Plane for elliptical galaxies has been constructed in I. The velocity
dispersion of Maffei 1, measured to be 186.8 +/- 7.4 km/s, in combination with
modern wide-field photometry in I, leads to a distance of 2.92 +/- 0.37 Mpc.
The Dn-sigma relation, which is independently calibrated, gives 3.08 +/- 0.85
Mpc and 3.23 +/- 0.67 Mpc from photometry in B and K`, respectively. The
weighted mean of the three estimates is 3.01 +/- 0.30 Mpc. The distance and
luminosity make Maffei 1 the nearest giant elliptical galaxy. The radial
velocity of Maffei 1 is +66.4 +/- 5.0 km/s, significantly higher than the
accepted value of -10 km/s. The Hubble distance corresponding to the mean
velocity of Maffei 1, Maffei 2 and IC342 is 3.5 Mpc. Thus, it is unlikely that
Maffei 1 has had any influence on Local Group dynamics
Status of the Cylindical-GEM project for the KLOE-2 Inner Tracker
The status of the R&D on the Cylindrical-GEM (CGEM) detector foreseen as
Inner Tracker for KLOE-2, the upgrade of the KLOE experiment at the DAFNE
phi-factory, will be presented. The R&D includes several activities: i) the
construction and complete characterization of the full-size CGEM prototype,
equipped with 650 microns pitch 1-D longitudinal strips; ii) the study of the
2-D readout with XV patterned strips and operation in magnetic field (up to
1.5T), performed with small planar prototypes in a dedicated test at the H4-SPS
beam facility; iii) the characterization of the single-mask GEM technology for
the realization of large-area GEM foils.Comment: 4 pages, 10 figures, Presented at Vienna Conference on
Instrumentation (Feb 15-20, 2010, Vienna, Austria). Submitted to the
Proceeding
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