2,913 research outputs found
Etude des couches de passage Couvinien-Givetien entre la vallée de l'Ourthe et la vallée de l'Aisne
This paper deals mainly with the sections in the Aisne Valley, at Rouge-Minière and Sy. A small section at Filot completes that of Sy. Certain observation could also be made in the Pont-le-Prêtre stream section, near Villers-Sainte-Gertrude and at Ferrières. These sections have allowed a better appreciation of the important variations in facies which occur near the Couvinian-Givetian boundary. This boundary has been delimited more exactly on the basis of ostracods, conodonts and corals
Efficient Large-scale Trace Checking Using MapReduce
The problem of checking a logged event trace against a temporal logic
specification arises in many practical cases. Unfortunately, known algorithms
for an expressive logic like MTL (Metric Temporal Logic) do not scale with
respect to two crucial dimensions: the length of the trace and the size of the
time interval for which logged events must be buffered to check satisfaction of
the specification. The former issue can be addressed by distributed and
parallel trace checking algorithms that can take advantage of modern cloud
computing and programming frameworks like MapReduce. Still, the latter issue
remains open with current state-of-the-art approaches.
In this paper we address this memory scalability issue by proposing a new
semantics for MTL, called lazy semantics. This semantics can evaluate temporal
formulae and boolean combinations of temporal-only formulae at any arbitrary
time instant. We prove that lazy semantics is more expressive than standard
point-based semantics and that it can be used as a basis for a correct
parametric decomposition of any MTL formula into an equivalent one with
smaller, bounded time intervals. We use lazy semantics to extend our previous
distributed trace checking algorithm for MTL. We evaluate the proposed
algorithm in terms of memory scalability and time/memory tradeoffs.Comment: 13 pages, 8 figure
Integrating aerodynamics and structures in the minimum weight design of a supersonic transport wing
An approach is presented for determining the minimum weight design of aircraft wing models which takes into consideration aerodynamics-structure coupling when calculating both zeroth order information needed for analysis and first order information needed for optimization. When performing sensitivity analysis, coupling is accounted for by using a generalized sensitivity formulation. The results presented show that the aeroelastic effects are calculated properly and noticeably reduce constraint approximation errors. However, for the particular example selected, the error introduced by ignoring aeroelastic effects are not sufficient to significantly affect the convergence of the optimization process. Trade studies are reported that consider different structural materials, internal spar layouts, and panel buckling lengths. For the formulation, model and materials used in this study, an advanced aluminum material produced the lightest design while satisfying the problem constraints. Also, shorter panel buckling lengths resulted in lower weights by permitting smaller panel thicknesses and generally, by unloading the wing skins and loading the spar caps. Finally, straight spars required slightly lower wing weights than angled spars
Application of multidisciplinary optimization methods to the design of a supersonic transport
An optimization design method is discussed. This method is based on integrating existing disciplinary analysis and sensitivity analysis techniques by means of generalized sensitivity equations. A generic design system implementing this method is described. The system is being used to design the configuration and internal structure of a supersonic transport wing for optimum performance. This problem combines the disciplines of linear aerodynamics, structures, and performance. Initial results which include the disciplines of aerodynamics and structures in a conventional minimum weight design under static aeroelastic constraints are presented
Risk and protective factors for meningococcal disease in adolescents: matched cohort study
Objective: To examine biological and social risk factors for
meningococcal disease in adolescents.
Design: Prospective, population based, matched cohort study
with controls matched for age and sex in 1:1 matching.
Controls were sought from the general practitioner.
Setting: Six contiguous regions of England, which represent
some 65% of the country’s population.
Participants: 15-19 year olds with meningococcal disease
recruited at hospital admission in six regions (representing 65%
of the population of England) from January 1999 to June 2000,
and their matched controls.
Methods: Blood samples and pernasal and throat swabs were
taken from case patients at admission to hospital and from
cases and matched controls at interview. Data on potential risk
factors were gathered by confidential interview. Data were
analysed by using univariate and multivariate conditional
logistic regression.
Results: 144 case control pairs were recruited (74 male (51%);
median age 17.6). 114 cases (79%) were confirmed
microbiologically. Significant independent risk factors for
meningococcal disease were history of preceding illness
(matched odds ratio 2.9, 95% confidence interval 1.4 to 5.9),
intimate kissing with multiple partners (3.7, 1.7 to 8.1), being a
university student (3.4, 1.2 to 10) and preterm birth (3.7, 1.0 to
13.5). Religious observance (0.09, 0.02 to 0.6) and
meningococcal vaccination (0.12, 0.04 to 0.4) were associated
with protection.
Conclusions: Activities and events increasing risk for
meningococcal disease in adolescence are different from in
childhood. Students are at higher risk. Altering personal
behaviours could moderate the risk. However, the development
of further effective meningococcal vaccines remains a key
public health priority
Primary Intravascular Synovial Sarcoma of the Femoral Vein in a Male Patient, Case Report
AbstractSynovial Sarcoma (SS) is an aggressive neoplasm commonly affecting deep soft tissues of the extremities. In rare instances SS can arise in large veins of the lower extremities or trunk. We report the first case of intravascular synovial sarcoma (IVSS) occurring in a male patient. A biphasic tumor was diagnosed by histology and immunohistochemistry. Molecular analysis at RNA level confirmed the diagnosis demonstrating the chromosomal translocation t(X;18) (p11.2;q11.2) in the tumor. Although extremely rare, IVSS should be considered in the differential diagnosis of primary intravascular neoplasms and as a potential cause of deep vein thrombosis and thromboembolism
Systems Level Metabolic Phenotype of Methotrexate Administration in the Context of Non-alcoholic Steatohepatitis in the Rat.
Adverse drug reactions (ADRs) represent a significant clinical challenge with respect to patient morbidity and mortality. We investigated the hepatotoxicity and systems level metabolic phenotype of methotrexate (MTX) in the context of a prevalent liver disease; non-alcoholic steatohepatitis (NASH). A nuclear magnetic resonance spectroscopic-based metabonomic approach was employed to analyze the metabolic consequences of MTX (0, 10, 40, and 100 mg/kg) in the urine and liver of healthy rats (control diet) and in a model of NASH (methionine-choline deficient diet). Histopathological analysis confirmed baseline (0 mg/kg) liver necrosis, liver inflammation, and lipid accumulation in the NASH model. Administration of MTX (40 and 100 mg/kg) led to liver necrosis in the control cohort, whereas the NASH cohort also displayed biliary hyperplasia and liver fibrosis (100 mg/kg), providing evidence of the synergistic effect of MTX and NASH. The complementary hepatic and urinary metabolic phenotypes of the NASH model, at baseline, revealed perturbation of multiple metabolites associated with oxidative and energetic stress, and folate homeostasis. Administration of MTX in both diet cohorts showed dose-dependent metabolic consequences affecting gut microbial, energy, nucleobase, nucleoside, and folate metabolism. Furthermore, a unique panel of metabolic changes reflective of the synergistic effect of MTX and NASH was identified, including the elevation of hepatic phenylalanine, urocanate, acetate, and both urinary and hepatic formiminoglutamic acid. This systems level metabonomic analysis of the hepatotoxicity of MTX in the context of NASH provided novel mechanistic insight of potential wider clinical relevance for further understanding the role of liver pathology as a risk factor for ADRs
Conceptualizing throughput legitimacy: procedural mechanisms of accountability, transparency, inclusiveness and openness in EU governance
This symposium demonstrates the potential for throughput legitimacy as a concept for shedding empirical light on the strengths and weaknesses of multi-level governance, as well as challenging the concept theoretically. This article introduces the symposium by conceptualizing throughput legitimacy as an ‘umbrella concept’, encompassing a constellation
of normative criteria not necessarily empirically interrelated. It argues that in order to interrogate multi-level governance processes in all their complexity, it makes sense for us to develop normative standards that are not naïve about the empirical realities of how power is exercised within multilevel governance, or how it may interact with legitimacy. We argue that while throughput legitimacy has its normative limits, it can be substantively useful for these purposes. While being no replacement for input and output legitimacy, throughput legitimacy offers distinctive normative criteria— accountability, transparency, inclusiveness and openness— and points towards substantive institutional reforms.Published versio
Saharan dust events at the Jungfraujoch: detection by wavelength dependence of the single scattering albedo and analysis of the events during the years 2001 and 2002
International audienceScattering and absorption coefficients have been measured continuously at several wavelengths since March 2001 at the high altitude site Jungfraujoch (3580 m a.s.l.). From these data, the wavelength dependences of the Ångström exponent and particularly of the single scattering albedo are determined. While the exponent of the single scattering albedo is usually positive, it becomes negative during Saharan dust events (SDE) due to the greater size of the mineral aerosols and to their different chemical composition. This change in the sign of the single scattering exponent turns out to be a simple means for detecting Saharan dust events. The occurrence of SDE detected by this new method was largely confirmed by visual inspection of filter colors and by studying long-range back-trajectories. An examination of SDE over a 22 months period shows that SDE are more frequent during the March?June period as well as during October and November. The trajectory analysis indicated a mean traveling time of 96.5 h with the most important source countries situated in the northern and north-western part of the Saharan desert. Most of the SDE do not lead to a detectable increase of the 48 h total suspended particulate matter (TSP) at the Jungfraujoch. During Saharan dust events, the average contribution of this dust to hourly TSP at the JFJ is 16 ?g/m3, which corresponds to an annual mean of 0.8 ?g/m3 or 24% of TSP
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