6,247 research outputs found
Multichannel operation of an integrated acousto-optic wavelength routing switch for WDM systems
Polarization independent acousto-optic tunable filters (PIAOTF's) can operate as transparent wavelength-selective crossconnects to route signals in wavelength division multiplexed optical networks. In this paper, a new low power PIAOTF is characterized as a switch in multiwavelength operation, using four equally spaced lightwave signals with wavelengths between 1546 nm and 1558 nm. Interchannel interference due to sidelobe excitation is lower than -11 dB for single wavelength switching and is equal to -6 dB in the extreme case of simultaneous switching of all wavelength channels. Sources of interport and interchannel crosstalk for single and multiple wavelength switching are identified
Human tularemia in Italy. Is it a re-emerging disease?
In order to evaluate whether tularemia is re-emerging in Italy, data on mortality and morbidity (obtained by the National Institute of Statistics; ISTAT), Italian cases described in the scientific literature and data concerning hospitalizations for tularemia (obtained by the National Hospital Discharge Database) were analysed. From 1979 to 2010, ISTAT reported 474 cases and no deaths. The overall number of cases obtained from the literature review was at least 31% higher than that reported by ISTAT. Moreover, the number of cases reported by ISTAT was 3·5 times smaller than hospitalized cases. The real frequency of the disease should be carefully investigated and taken into account in order to implement specific prevention measures.Tularemia is a contagious infectious disease due to Francisiella tularensis that can cause serious clinical manifestations and significant mortality if untreated. Although the frequency and significance of the disease has diminished over the last decades in Central Europe, over the past few years, there is new evidence suggesting that tularemia has re-emerged worldwide. To know the real epidemiology of the disease is at the root of correct control measures. In order to evaluate whether tularemia is re-emerging in Italy, data on mortality and morbidity (obtained by the National Institute of Statistics; ISTAT), Italian cases described in the scientific literature and data concerning hospitalizations for tularemia (obtained by the National Hospital Discharge Database) were analysed. From 1979 to 2010, ISTAT reported 474 cases and no deaths. The overall number of cases obtained from the literature review was at least 31% higher than that reported by ISTAT. Moreover, the number of cases reported by ISTAT was 3·5 times smaller than hospitalized cases. In Italy tularemia is sporadic, rarely endemic and self-limiting; but, although the trend of reported tularemia does not support the hypothesis of a re-emerging disease, the study demonstrates a wide underreporting of the disease. The real frequency of the disease should be carefully investigated and taken into account in order to implement specific prevention measures
A pediatric digital storytelling system for third year medical students: The Virtual Pediatric Patients
BACKGROUND: Computer-based patient simulations (CBPS) are common, effective, instructional methods for medical students, but have limitations. The goal of this project was to describe the development of a CBPS designed to overcome some of these limitations and to perform an online evaluation. METHODS: In 1996, patients and families experiencing a common pediatric problem were interviewed, photographed and a chart review completed. A digital storytelling template was developed: 1. patient's story, evaluation and clinical course, 2. problem-based approach to the evaluation, and 3. discussion of disease process. The media was digitized and placed onto the Internet. The digital stories and a 10-question online survey were pilot tested. Online survey responses were collected from 1999–2003. Overall use of the digital stories was measured by computer server logs and by the number of hyperlinks to the CBPS. RESULTS: Eight stories were created using this system. Over 4.5 years, 814,148 digital story pages were read by 362,351 users. Hyperlink citations from other websites to the CBPS were 108. Online survey respondents (N = 393) described the overall quality as excellent or very good (88.4%). The stores were clearly written (92%) at an appropriate level (91.4%). Respondents felt they could begin to evaluate a similar case presentation (95.4%), and would remember the case in the future (91%). CONCLUSIONS: A new type of CBPS, the digital storytelling system, has been developed and evaluated which and appears to be successful in overcoming some of the limitations of earlier CBPS by featuring patient's stories in their own words, by focusing on problems rather than diseases, and by having stories that are quick for students to work through
Observations of microglitches in HartRAO radio pulsars
A detailed observation of microglitch phenomenon in relatively slow radio
pulsars is presented. Our analyses for these small amplitude jumps in pulse
rotation frequency () and/or spin down rate () combine the
traditional manual detection method (which hinges on careful visual inspections
of the residuals of pulse phase residuals) and a new, and perhaps more
objective, automated search technique (which exploits the power of the
computer, rather than the eyes, for resolving discrete events in pulsar spin
parameters). The results of the analyses of a sample of 26 radio pulsars reveal
that: (i) only 20 pulsars exhibit significant fluctuations in their arrival
times to be considered suitable for meaningful microglitch analyses; (ii) a
phenomenal 299 microglitch events were identified in and/or :
266 of these events were found to be simultaneously significant in and
, while 19 and 14 were noticeable only in and ,
respectively; (iii) irrespective of sign, the microglitches have fractional
sizes which cover about 3 orders of magnitude in and
( and ) with median values as
and , respectively.Comment: 12 pages, 3 figures, 2 Tables. Accepted for publication in Monthly
Notices of the Royal Astronomical Society Main Journa
Riuso delle acque grigie in ambiente domestico: implicazioni per la sanità pubblica
The Authors describe the main microbiological characteristics of gray and rain waters, the evidence of infections related to the reuse of such waters and the main Italian and international standards and guidelines in this regard. In light of the review, the authors conclude that the limits defined by the Italian regulations are very precautionary and should ensure a very low risk of bacterial and/or viral infection (< 10.5 and 10.9 cases/year). It remains an open problem the risk of parasitic infections, for which the evidences to draw final conclusions are not sufficient yet
Classification and Statistical Trend Analysis in Detecting Glaucomatous Visual Field Progression
Aim. To evaluate the agreement between different methods in detection of glaucomatous visual field progression using two classification-based methods and four statistical approaches based on trend analysis. Methods. This is a retrospective and longitudinal study. Twenty Caucasian patients (mean age 73.8 \ub1 13.43 years) with open-Angle glaucoma were recruited in the study. Each visual field was assessed by Humphrey Field Analyzer, program SITA standard 30-2 or 24-2 (Carl Zeiss Meditec, Inc., Dublin, CA). Full threshold strategy was also accepted for baseline tests. Progression was analyzed by using Hodapp-Parrish-Anderson classification and the Advanced Glaucoma Intervention Study visual field defect score. For the statistical analysis, linear regression (r2) was calculated for mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI), and when it was significant, each series of visual field was considered progressive. We also used Progressor to look for a significant progression of each visual field series. The agreement between methods, based on statistical analysis and classification, was evaluated using a weighted kappa statistic. Results. Thirty-eight visual field series were analyzed. The mean follow-up time was 6.2 \ub1 1.53 years (mean \ub1 standard deviation). At baseline, the mean MD was-7.34 \ub1 7.18 dB; at the end of the follow-up, the mean MD was-9.25 \ub1 8.65 dB; this difference was statistically significant (p<0.001). The agreement to detect progression was fair between all methods based on statistical analysis and classification except for PSD r2. A substantial agreement ( = 0.698 \ub1 0.126) was found between MD r2 and VFI r2. With the use of all the statistical analysis, there was a better time-saving. Conclusions. The best agreement to detect progression was found between MD r2 and VFI r2. VFI r2 showed the best agreement with all the other methods. GPA2 can help ophthalmologists to detect glaucoma progression and to help in treatment decisions. PSD r2 was the worse method to detect progression
Magnetic Component of Quark-Gluon Plasma
We describe recent developments of the "magnetic scenario" of sQGP. We show
that at there is a dense plasma of monopoles, capable of
supporting metastable flux tubes. Their existence allows to quantitatively
explained the non-trivial -dependence of the static potential
energy calculated on the lattice. By molecular dynamics simulation we derived
transport properties (shear viscosity and diffusion constant) and showed that
the best liquid is given by most symmetric plasma, with 50%-50% of electric and
magnetic charges. The results are close to those of the ``perfect liquid''
observed at RHIC.Comment: Contribution to the 20th International Conference on Nucleus Nucleus
Collisions (Quark Matter 2008
The additional-mode garden of RR Lyrae stars
Space-based photometric missions revealed a surprising abundance of
millimagnitude-level additional modes in RR Lyrae stars. The modes that appear
in the modulated fundamental-mode (RRab) stars can be ordered into four major
categories. Here we present the distribution of these groups in the Petersen
diagram, and discuss their characteristics and connections to additional modes
observed in other RR Lyrae stars.Comment: 4 pages, 4 figures, proceedings of the Joint
TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant
Stars 2016", to be published in EPJ Wo
Spar buoy numerical model calibration and verification
The present paper describes the experiences gained from the design methodology
and operation of a 3D physical model experiment aimed to investigate the dynamic behavior of a spar
buoy (SB) off-shore floating wind turbine (WT) under different wind and wave con- ditions.
The physical model tests have been performed at Danish Hydraulic Institute (DHI) off-shore wave
basin within the European Union-Hydralab IV Integrated Infrastructure Initiative, in
October 2012. The floating WT model has been subjected to a combination of regular and
irregular wave attacks and steady wind loads. Observations of hydrodynamics, displacements of the
floating structure, wave induced pressures and tensions at critical points of the structure and at
the mooring lines have been carried out. Based on the observed data, the numerical model
Sesam [1], developed by Det Norske Veritas (DNV), has been calibrated and verified. The adopted
numerical model took into account the wave induced response and the effects of the mooring lines on
the overall system.
The calibration of the numerical model has been performed both for static and dynamic condi- tions.
At the end of the calibration procedure, the numerical model has been successfully used to
simulate two selected irregular wave attacks
Aqueye+: a new ultrafast single photon counter for optical high time resolution astrophysics
Aqueye+ is a new ultrafast optical single photon counter, based on single
photon avalanche photodiodes (SPAD) and a 4-fold split-pupil concept. It is a
completely revisited version of its predecessor, Aqueye, successfully mounted
at the 182 cm Copernicus telescope in Asiago. Here we will present the new
technological features implemented on Aqueye+, namely a state of the art timing
system, a dedicated and optimized optical train, a high sensitivity and high
frame rate field camera and remote control, which will give Aqueye plus much
superior performances with respect to its predecessor, unparalleled by any
other existing fast photometer. The instrument will host also an optical
vorticity module to achieve high performance astronomical coronography and a
real time acquisition of atmospheric seeing unit. The present paper describes
the instrument and its first performances.Comment: Proceedings of the SPIE, Volume 9504, id. 95040C 14 pp. (2015
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