NIHSS Scores in Ischemic Small Vessel Disease: A Study in CADASIL

Background: The National Institutes of Health Stroke Scale (NIHSS) is widely used to measure neurological deficits, evaluate the effectiveness of treatment and predict outcome in acute ischemic stroke. It has also been used to measure the residual neurological deficit at the chronic stage after ischemic events. However, the value of NIHSS in ischemic cerebral small vessel disease has not been specifically evaluated. The purpose of this study was to investigate the link between the NIHSS score and clinical severity in a large population of subjects with CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), a unique model to investigate the pathophysiology and natural history of ischemic small vessel disease. Methods: Demographic and clinical data of 220 patients with one or more lacunar infarcts confirmed by MRI examination and enrolled from a prospective cohort study were analyzed. Detailed neurological examinations, including evaluation of the NIHSS and modified Rankin Scale score (mRS) for evaluating the clinical severity, were performed in all subjects. The sensitivity, specificity, positive and negative predictive values of various NIHSS thresholds to capture the absence of significant disability (mRS = 3, but only 16 (7.3%) had NIHSS >5. All but 1 subject with NIHSS >5 showed mRS >= 3. NIHSS = 3 showed a lower MMSE score than those with mRS = 3 presented either with gait disturbances or MMSE score <25. Conclusions: The present results suggest that the NIHSS cannot reflect the extent of neurological deficit and clinical severity in subjects with lacunar infarctions in the context of a chronic and diffuse small vessel disease. A specific and global neurological scale, including the assessment of cognitive and gait performances, should be developed for ischemic cerebral microangiopathy. Copyright (C) 2012 S. Karger AG, Base

Confluent Thalamic Hyperintensities in CADASIL

Background: CADASIL is responsible for diffuse hyperintensities in the white matter on FLAIR images. These lesions are often associated with focal lesions in the basal ganglia such as lacunar infarctions. The prevalence and significance of diffuse or confluent thalamic hyperintensities (CTH) remain unknown. Methods: The frequency of hyperintensities on FLAIR images in the thalamus was assessed in 147 CADASIL patients, and signal abnormalities on both FLAIR and T(1)-weighted images were categorized as focal/punctuate or diffuse/confluent by the same reader. The areas of increased diffusion were also analyzed on apparent diffusion coefficient maps. The association of CTH with vascular risk factors, the main clinical manifestations of the disease and MRI markers (brain parenchymal fraction, volume of white matter hyperintensities, volume of lacunar infarcts and number of microbleeds) was analyzed with generalized linear regression models. Results: CTH were detected in 12% of the CADASIL subjects in association with hypointensities on T(1)-weighted images. CTH corresponded to areas of increased diffusion apparent diffusion coefficient maps. CTH were found significantly associated with age and independently related to the volume of white matter hyperintensities but not to that of lacunar infarctions or to cerebral atrophy after adjustment for age and sex. No significant association was found between CTH and global cognitive performances. Conclusion: CTH are observed on FLAIR images in a sizeable proportion of CADASIL patients. They are mainly related to the extent of white matter hyperintensities and do not correlate with cognitive decline. Demyelination and/or loss of glial cells appear to be the most plausible cause of these confluent signal changes in the thalamus. Copyright (C) 2010 S. Karger AG, Base

Stratification of the Information Space in Web Based Information Systems

Web-based Information Systems (WIS) are used for diffusing and processing information over the Internet. Because of the large amounts of information they manage, it is crucial to adapt the delivered information to users and to give them a progressive access to information. For this purpose, we propose to stratify the Information Space of a WIS by decomposing it into personalized sub- Information Spaces. Multimedia data can also be stratified into multiple formats used for their presentation. These stratifications are described through a Progressive Access Model (PAM) written in UML. In order to personalize the progressive access, the PAM is linked to both the data model of the application domain and to a Generic User Model describing the rights and preferences of users. We also show that, based on these stratifications, navigation mechanisms allow users to access first some minimum and essential information, and then larger and/or smaller personalized Information Spaces

Is Open Hardware Worthwhile? Learning from Thales' Experience with RISC-V

Overview In this article we frame the concept of a hardware-rich open source ecosystem (H-ROSE) that generates software and hardware components. In an H-ROSE, the designs of some components are accessible under open source licenses, while other component designs remain proprietary. We describe seven adoption factors used by the multinational French firm Thales to assess the efficacy of RISC-V to design processors. Other companies can use these adoption factors to explore whether an open hardware initiative supported by an H-ROSE is worthwhile.Peer reviewe

Towards investigation of external oil flow from a journal bearing in an epicyclic gearbox

High loads and bearing life requirements make journal bearings the preferred choice for use in high power, planetary gearboxes in jet engines. With the planet gears rotating about their own axis and orbiting around the sun gear, centrifugal forces generated by both motions interact with each and generate complex kinematic conditions. This paper presents a literature and state-of-the-art knowledge review to identify existing work performed on cases similar to external journal bearing oil flow. In order to numerically investigate external journal bearing oil flow, an approach to decompose an actual journal bearing into simplified models is proposed. Preliminary modeling considerations are discussed. The findings and conclusions are used to create a three dimensional (3D), two-component computational fluid dynamic (CFD) sector model with rotationally periodic boundaries of the most simplistic approximation of an actual journal bearing: a non-orbiting representation, rotating about its own axis, with a circumferentially constant, i.e. concentric, lubricating gap. In order to track the phase interface between the oil and the air, the Volume of Fluid (VoF) method is used. External journal bearing oil flow is simulated with a number of different mesh densities. Two different operating temperatures, representing low and high viscosity oil, are used to assess the effect on the external flow field behaviour. In order to achieve the future objective of creating a design tool for routine use, key areas are identified in which further progress is required

Performance consistency of fed-batch cultures across multiple systems used in upstream process development

Each stage of cell culture process development requires fit for purpose tools. The selection of a fed-batch cultivation system is often based on throughput and cost. However, the process knowledge derived from different systems and scales is not necessarily identical. Hence, a careful evaluation of systems which are already established or newly implemented is essential. We recently introduced a novel high throughput fed-batch screening system (1) and the objective of this study was to provide data on how it compares with other systems used in early and late stage cell culture process development. We describe the performance of 12 different recombinant CHO cell lines expressing the same antibody in fed-batch culture systems ranging from a few hundred microliters to lab scale. The 12 cell lines were selected based on distinct phenotypes covering a range which can be expected in typical industrial process development projects. The cell lines were cultivated using the same expansion and fed-batch protocol (proprietary fed-batch system). The following cultivation systems were evaluated: shaking 96-deepwell plates, 50 mL vented shake tubes, micro-scale bioreactors (ambr15TM system) and lab-scale bioreactors (3L). The results of this study show both the limitations and the potential of each cultivation system and their suitability for process development, process characterization and scale-up. The shaking systems offer unprecedented parallel throughput but are limited with respect to culture control (e. g. lack of pH and pO2 control). Despite their limitations, they are expected to be used in the future as important tools for early process development and for the improvement of fed-batch platform processes. On the other hand, the data obtained from this study show that micro- and lab-scale bioreactors represent ideal tools for the confirmation of process consistency. Both micro- and lab-scale systems will be extensively used in the future to support tech transfers and perform process characterization studies

Can a quantum mixmaster universe undergo a spontaneous inflationary phase?

We study a semi-classical model of the mixmaster universe. We first derive the quantum model and then introduce its semi-classical approximation. We employ a general integral quantization method that respects the symmetries of the model given by the affine and the Weyl-Heisenberg groups, and can produce a wide class of quantum models. The semi-classical approximation is based on the coherent states. The semi-classical dynamics is complex and can not be solved by analytical methods. We focus on a key qualitative feature of the dynamics, namely, we investigate whether the primordial anisotropic universe can undergo a spontaneous inflationary phase driven by the anisotropic energy combined with semi-classical corrections. The answer to this question provides a useful perspective on the inflationary paradigm as well as on alternative bouncing models.Comment: 15 pages, 6 figure

Finite volume method in curvilinear coordinates for hyperbolic conservation laws

International audienceThis paper deals with the design of finite volume approximation of hyperbolic conservation laws in curvilinear coordinates. Such coordinates are encountered naturally in many problems as for instance in the analysis of a large number of models coming from magnetic confinement fusion in tokamaks. In this paper we derive a new finite volume method for hyperbolic conservation laws in curvilinear coordinates. The method is first described in a general setting and then is illustrated in 2D polar coordinates. Numerical experiments show its advantages with respect to the use of Cartesian coordinates

On the use of the sterile insect technique or the incompatible insect technique to reduce or eliminate mosquito populations

Vector control is critical to limit the circulation of vector-borne diseases like chikungunya, dengue or zika which have become important issues around the world. Among them the Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) recently aroused a renewed interest. In this paper we derive and study a minimalistic mathematical model designed for Aedes mosquito population elimination by SIT/IIT. Contrary to most of the previous models, it is bistable in general, allowing simultaneously for elimination of the population and for its survival. We consider dierent types of releases (constant, periodic or impulsive) and show necessary conditions to reach elimination in each case. We also estimate both sucient and minimal treatment times. Biological parameters are estimated from a case study of an Aedes polynesiensis population, for which extensive numerical investigations illustrate the analytical results. The applications of this work are twofold: to help identifying some key parameters that may need further eld investigations, and to help designing release protocols