27 research outputs found
Interval Slopes as Numerical Abstract Domain for Floating-Point Variables
The design of embedded control systems is mainly done with model-based tools
such as Matlab/Simulink. Numerical simulation is the central technique of
development and verification of such tools. Floating-point arithmetic, that is
well-known to only provide approximated results, is omnipresent in this
activity. In order to validate the behaviors of numerical simulations using
abstract interpretation-based static analysis, we present, theoretically and
with experiments, a new partially relational abstract domain dedicated to
floating-point variables. It comes from interval expansion of non-linear
functions using slopes and it is able to mimic all the behaviors of the
floating-point arithmetic. Hence it is adapted to prove the absence of run-time
errors or to analyze the numerical precision of embedded control systems
Transjugular Intrahepatic Portosystemic Shunts With Covered Stents Increase Transplant-Free Survival of Patients With Cirrhosis and Recurrent Ascites
BACKGROUND & AIMS: There is controversy over the ability of transjugular intrahepatic portosystemic shunts (TIPS) to increase survival times of patients with cirrhosis and refractory ascites. The high rate of shunt dysfunction with the use of uncovered stents counteracts the benefits of TIPS. We performed a randomized controlled trial to determine the effects of TIPS with stents covered with polytetrafluoroethylene in these patients.
METHODS: We performed a prospective study of 62 patients with cirrhosis and at least 2 large-volume paracenteses within a period of at least 3 weeks; the study was performed at 4 tertiary care centers in France from August 2005 through December 2012. Patients were randomly assigned to groups that received covered TIPS (n = 29) or large-volume paracenteses and albumin as necessary (LVP+A, n = 33). All patients maintained a low-salt diet and were examined at 1 month after the procedure then every 3 months until 1 year. At each visit, liver disease-related complications, treatment modifications, and clinical and biochemical variables needed to calculate Child-Pugh and Model for End-Stage Liver Disease scores were recorded. Doppler ultrasonography was performed at the start of the study and then at 6 and 12 months after the procedure. The primary study end point was survival without a liver transplant for 1 year after the procedure.
RESULTS: A higher proportion of patients in the TIPS group (93%) met the primary end point than in the LVP+A group (52%) (PÂ = .003). The total number of paracenteses was 32 in the TIPS group vs 320 in the LVP+A group. Higher proportions of patients in the LVP+A group had portal hypertension-related bleeding (18% vs 0%; PÂ = .01) or hernia-related complications (18% vs 0%; PÂ = .01) than in the TIPS group. Patients in LVP+A group had twice as many days of hospitalization (35 days) as the TIPS group (17 days) (PÂ = .04). The 1-year probability of remaining free of encephalopathy was 65% for each group.
CONCLUSIONS: In a randomized trial, we found covered stents for TIPS to increase the proportion of patients with cirrhosis and recurrent ascites who survive transplantation-free for 1 year, compared with patients given repeated LVP+A. These findings support TIPS as the first-line intervention in such patients. ClinicalTrials.gov ID: NCT00222014
The tectonic significance of the Cabo Frio Tectonic Domain in the SE Brazilian margin: a Paleoproterozoic through Cretaceous saga of a reworked continental margin
CA53 - Prévalence et facteurs clinico-biologiques associés à la dénutrition protéino-énergétique (DPE) : Analyse prospective chez 105 malades cirrhotiques
CA52 - Analyse des facteurs modulant lâalbuminĂ©mie au cours de la cirrhose : Ă©tude prospective chez 115 malades
Géographie et cultures n° 2
Lieu de confrontation d'idĂ©es et d'expĂ©riences, GĂ©ographie et cultures rĂ©pond Ă l'intĂ©rĂȘt renouvelĂ© de la gĂ©ographie pour les faits de civilisation, et des sciences sociales pour l'environÂnement. Quel est le rĂŽle de l'espace gĂ©ographique dans la structuration d'une culture ? Comment se perçoit l'influence d'une civilisation dans l'organisation par les hommes de leur espace et de leur milieu ? Un domaine fĂ©cond et encore peu explorĂ© s'ouvre Ă l'analyse, lorsqu'on observe les relations entre phĂ©nomĂšnes gĂ©ographiques (espace, milieu, territoire, paysage, rĂ©gions...) et phĂ©nomĂšnes culturels (identitĂ©, valeur, mĂ©moire, reprĂ©Âsentations...). Cette revue de gĂ©ographie culturelle et d'ethnogĂ©ographie s'adresse Ă tous ceux qui s'interrogent sur les interactions entre espace et culture, sous toutes les latitudes et Ă toutes les Ă©chelles : historiens, ethnologues, sociologues, psychologues, gĂ©ographes ou Ă©crivains
An Abstract Domain to Infer Octagonal Constraints with Absolute Value
International audienceThe octagon abstract domain, devoted to discovering octagonal constraints (also called Unit Two Variable Per Inequality or UTVPI constraints) of a program, is one of the most commonly used numerical abstractions in practice, due to its quadratic memory complexity and cubic time complexity. However, the octagon domain itself is restricted to express convex sets and has limitations in handling non-convex properties which are sometimes required for proving some numerical properties in a program. In this paper, we intend to extend the octagon abstract domain with absolute value, to infer certain non-convex properties by exploiting the absolute value function. More precisely, the new domain can infer relations of the form {±X ± Y †c, ±X ± |Y| †d, ±|X| ± |Y| †e}. We provide algorithms for domain operations such that the new domain still enjoys the same asymptotic complexity as the octagon domain. Moreover, we present an approach to support strict inequalities over rational or real-valued variables in this domain, which also fits for the octagon domain. Experimental results of our prototype are encouraging; The new domain is scalable and able to find non-convex invariants of interest in practice but without too much overhead (compared with that using octagons)
Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei
7 pags., 4 figs.Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at âŒ250 MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.We thank the RIBF and BigRIPS teams for providing a
stable beam and optimum settings over the two experimental campaigns. A. F. acknowledges support from the
DFG under Grant No. SFB1245. M. G.-R. acknowledges
support from the Alexander von Humboldt foundation.
A. O. thanks the European Research Council for its support
through ERC Grant No. MINOS-258567, the JSPS
Japanese Society for the Promotion of Science for the
long-term fellowship L-13520, the German DFG for its
support from the SFB Grant No. 1245, and the Alexander
von Humboldt Foundation for its support. K. Mo. acknowledges support from German BMBF Grant
No. 05P15PKFNA. M. L. C., M. L., and V. W. acknowledge support from German BMBF Grants
No. 05P15RDFN1, and No. 05P19RDFN1, as well as
DFG Grant No. SFB 1245. L. X. C. and B. D. L. are
supported by the Vietnam MOST through Physics
Development Program Grant No. Ă TĂ LCN.25/18 and
acknowledge the Radioactive Isotope Physics Laboratory
of the RIKEN Nishina Center for supporting their stay
during the experiment. A. J. and V. V. acknowledge
support from the Spanish Ministerio de EconomĂa y
Competitividad under Contract No. FPA2017-84756-C4-2-
P. U.K. participants acknowledge support from the Science
and Technology Facilities Council (STFC). Collaborators
from I. M. P. were supported by the National Natural
Science Foundation of China and the Chinese Academy
of Sciences. R. T. was supported by the JSPS Grant-in-Aid
for JSPS Research Fellows JP14J08718. Zs. D., Z. K., and
Zs. V. acknowledge the support from Projects No. OTKA
K128947 and No. GINOP-2.3.3-15-2016-00034. C.
Santamaria acknowledges support by the IPA program at
the RIKEN Nishina Center