750 research outputs found
Cystic Dilation of Extrahepatic Bile Ducts in Adulthood: Diagnosis, Surgical Treatment and Long. Term Results
To evaluate the long-term results of surgery for choledohal cyst in adulthood, a series of 13 patients over the age of 16 operated on for choledochal cyst during a period of six years and followed-up for a minimum of 3 years was analyzed. Patients with type I and IVa cysts underwent extrahepatic cyst resection and Roux-en-Y hepatico-jejunostomy. Choledochoceles (type III) were managed endoscopically. No operative mortality or morbidity occurred. Type I and III cysts showed almost ideal follow-up with no sign of stricture on HIDA scan. One type IVa cyst patients developed recurrent cholangitis due to anastomotic stricture, managed percutaneously. Whenever possible, complete cyst resection and Roux-en-Y reconstruction is the treatment of choice for all extrahepatic biliary cysts. Intra- and extrahepatic dilatations are adequately treated by extrahepatic resection and careful endoscopic or radiologic surveillance. Small choledochoceles can be safely managed by endoscopic sphincterotomy
How Many Templates for GW Chirp Detection? The Minimal-Match Issue Revisited
In a recent paper dealing with maximum likelihood detection of gravitational
wave chirps from coalescing binaries with unknown parameters we introduced an
accurate representation of the no-signal cumulative distribution of the
supremum of the whole correlator bank. This result can be used to derive a
refined estimate of the number of templates yielding the best tradeoff between
detector's performance (in terms of lost signals among those potentially
detectable) and computational burden.Comment: submitted to Class. Quantum Grav. Typing error in eq. (4.8) fixed;
figure replaced in version
NICMOS Imaging of the Host Galaxies of z ~ 2 - 3 Radio-Quiet Quasars
We have made a deep NICMOS imaging study of a sample of 5 z ~ 2 - 3
radio-quiet quasars with low absolute nuclear luminosities, and we have
detected apparent host galaxies in all of these. Most of the hosts have
luminosities approximately equal to present-day L*, with a range from 0.2 L* to
about 4 L*. These host galaxies have magnitudes and sizes consistent with those
of the Lyman break galaxies at similar redshifts and at similar rest
wavelengths, but are about two magnitudes fainter than high-z powerful radio
galaxies. The hosts of our high-z sample are comparable to or less luminous
than the hosts of the low-z RQQs with similar nuclear absolute magnitudes.
However, the high z galaxies are more compact than the hosts of the low z
quasars, and probably have only 10 - 20% of the stellar mass of their low-z
counterparts. Application of the M(bulge)/M(BH) relation found for present-day
spheroids to the stellar masses implied for the high z host galaxies would
indicate that they contain black holes with masses around 10^8 Msolar.
Comparison to their nuclear magnitudes implies accretion rates that are near or
at the Eddington limit. Although these high z hosts already contain
supermassive black holes, the galaxies will need to grow significantly to
evolve into present-day L* galaxies. These results are basically consistent
with theoretical predictions for the hierarchical buildup of the galaxy host
and its relation to the central supermassive black hole.Comment: 25 pages, 13 figures, accepted for publication in Ap
Correlator Bank Detection of GW chirps. False-Alarm Probability, Template Density and Thresholds: Behind and Beyond the Minimal-Match Issue
The general problem of computing the false-alarm rate vs. detection-threshold
relationship for a bank of correlators is addressed, in the context of
maximum-likelihood detection of gravitational waves, with specific reference to
chirps from coalescing binary systems. Accurate (lower-bound) approximants for
the cumulative distribution of the whole-bank supremum are deduced from a class
of Bonferroni-type inequalities. The asymptotic properties of the cumulative
distribution are obtained, in the limit where the number of correlators goes to
infinity. The validity of numerical simulations made on small-size banks is
extended to banks of any size, via a gaussian-correlation inequality. The
result is used to estimate the optimum template density, yielding the best
tradeoff between computational cost and detection efficiency, in terms of
undetected potentially observable sources at a prescribed false-alarm level,
for the simplest case of Newtonian chirps.Comment: submitted to Phys. Rev.
MLIP genotype as a predictor of pharmacological response in primary open-angle glaucoma and ocular hypertension.
Predicting the therapeutic response to ocular hypotensive drugs is crucial for the clinical treatment and management of glaucoma. Our aim was to identify a possible genetic contribution to the response to current pharmacological treatments of choice in a white Mediterranean population with primary open-angle glaucoma (POAG) or ocular hypertension (OH). We conducted a prospective, controlled, randomized, partial crossover study that included 151 patients of both genders, aged 18 years and older, diagnosed with and requiring pharmacological treatment for POAG or OH in one or both eyes. We sought to identify copy number variants (CNVs) associated with differences in pharmacological response, using a DNA pooling strategy of carefully phenotyped treatment responders and non-responders, treated for a minimum of 6 weeks with a beta-blocker (timolol maleate) and/or prostaglandin analog (latanoprost). Diurnal intraocular pressure reduction and comparative genome wide CNVs were analyzed. Our finding that copy number alleles of an intronic portion of the MLIP gene is a predictor of pharmacological response to beta blockers and prostaglandin analogs could be used as a biomarker to guide first-tier POAG and OH treatment. Our finding improves understanding of the genetic factors modulating pharmacological response in POAG and OH, and represents an important contribution to the establishment of a personalized approach to the treatment of glaucoma
A forecasting model to estimate the drop in blood supplies during the SARS-CoV-2 pandemic in Italy
Objectives: To estimate the number of actually Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infected blood donors applying a statistical forecasting model. Background: Following the outbreak of the SARS-CoV-2 epidemic, a drop in blood donation has been observed. It is crucial to determine the actual number of potential SARS-CoV-2-positive donors to define the measures and ensure adequate blood supply. Methods: The cumulative incidence of SARS-CoV-2 positivity, calculated on the general population, was applied to the donor population by estimating the number of positive subjects. The calculation model was validated by the linear interpolation method. The number of blood units actually discarded based on post-donation information was also taken into account. Results: Three months after the outbreak, 5322 donors were estimated to be positive for SARS-CoV-2 and were therefore potentially excluded from donation. A total of units of blood components were discarded following post donation information. The estimated number of donors deceased (180) and the number of clinically recovered individuals in the same period was also considered. Conclusion: This forecasting model can be used to obtain information on blood donors' involvement during future SARS-CoV-2 outbreaks, especially in case of changes concerning epidemiology, incidence by age bracket and geographical distribution and also for new outbreaks of emerging viruses
A rare case of cerebral venous thrombosis and disseminated intravascular coagulation temporally associated to the covid-19 vaccine administration
Globally, at the time of writing (20 March 2021), 121.759.109 confirmed COVID-19 cases have been reported to the WHO, including 2.690.731 deaths. Globally, on 18 March 2021, a total of 364.184.603 vaccine doses have been administered. In Italy, 3.306.711 confirmed COVID-19 cases with 103.855 deaths have been reported to WHO. In Italy, on 9 March 2021, a total of 6.634.450 vaccine doses have been administered. On 15 March 2021, Italian Medicines Agency (AIFA) decided to temporarily suspend the use of the AstraZeneca COVID-19 vaccine throughout the country as a precaution, pending the rulings of the European Medicines Agency (EMA). This decision was taken in line with similar measures adopted by other European countries due to the death of vaccinated people. On 18 March 2021, EMAâs safety committee concluded its preliminary review about thromboembolic events in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting, confirming the benefits of the vaccine continue to outweigh the risk of side effects, however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e., low levels of blood platelets with or without bleeding, including rare cases of cerebral venous thrombosis (CVT). We report the case of a 54-year-old woman who developed disseminated intravascular coagulation (DIC) with multi-district thrombosis 12 days after the AstraZeneca COVID-19 vaccine administration. A brain computed tomography (CT) scan showed multiple subacute intra-axial hemorrhages in atypical locations, including the right frontal and the temporal lobes. A plain old balloon angioplasty (POBA) of the right coronary artery was performed, without stent implantation, with restoration of distal flow, but with persistence of extensive thrombosis of the vessel. A successive thorax angio-CT added the findings of multiple contrast filling defects with multi-vessel involvement: at the level of the left upper lobe segmental branches, of left interlobar artery, of the right middle lobe segmental branches and of the right interlobar artery. A brain magnetic resonance imaging (MRI) in the same day showed the presence of an acute basilar thrombosis associated with the superior sagittal sinus thrombosis. An abdomen angio-CT showed filling defects at the level of left portal branch and at the level of right suprahepatic vein. Bilaterally, it was adrenal hemorrhage and blood in the pelvis. An evaluation of coagulation factors did not show genetic alterations so as the nasopharyngeal swab ruled out a COVID-19 infection. The patient died after 5 days of hospitalization in intensive care
The VIMOS Integral Field Unit: data reduction methods and quality assessment
With new generation spectrographs integral field spectroscopy is becoming a
widely used observational technique. The Integral Field Unit of the VIsible
Multi-Object Spectrograph on the ESO-VLT allows to sample a field as large as
54" x 54" covered by 6400 fibers coupled with micro-lenses. We are presenting
here the methods of the data processing software developed to extract the
astrophysical signal of faint sources from the VIMOS IFU observations. We focus
on the treatment of the fiber-to-fiber relative transmission and the sky
subtraction, and the dedicated tasks we have built to address the peculiarities
and unprecedented complexity of the dataset. We review the automated process we
have developed under the VIPGI data organization and reduction environment
(Scodeggio et al. 2005), along with the quality control performed to validate
the process. The VIPGI-IFU data processing environment is available to the
scientific community to process VIMOS-IFU data since November 2003.Comment: 19 pages, 10 figures and 1 table. Accepted for publication in PAS
The VVDS data reduction pipeline: introducing VIPGI, the VIMOS Interactive Pipeline and Graphical Interface
The VIMOS VLT Deep Survey (VVDS), designed to measure 150,000 galaxy
redshifts, requires a dedicated data reduction and analysis pipeline to process
in a timely fashion the large amount of spectroscopic data being produced. This
requirement has lead to the development of the VIMOS Interactive Pipeline and
Graphical Interface (VIPGI), a new software package designed to simplify to a
very high degree the task of reducing astronomical data obtained with VIMOS,
the imaging spectrograph built by the VIRMOS Consortium for the European
Southern Observatory, and mounted on Unit 3 (Melipal) of the Very Large
Telescope (VLT) at Paranal Observatory (Chile). VIPGI provides the astronomer
with specially designed VIMOS data reduction functions, a VIMOS-centric data
organizer, and dedicated data browsing and plotting tools, that can be used to
verify the quality and accuracy of the various stages of the data reduction
process. The quality and accuracy of the data reduction pipeline are comparable
to those obtained using well known IRAF tasks, but the speed of the data
reduction process is significantly increased, thanks to the large set of
dedicated features. In this paper we discuss the details of the MOS data
reduction pipeline implemented in VIPGI, as applied to the reduction of some
20,000 VVDS spectra, assessing quantitatively the accuracy of the various
reduction steps. We also provide a more general overview of VIPGI capabilities,
a tool that can be used for the reduction of any kind of VIMOS data.Comment: 10 pages, submitted to Astronomy and Astrophysic
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