Intraerythrocytic pH variations during hemodialysis: A 31P NMR study

Intraerythrocytic pH variations during hemodialysis: A 31P NMR study. Before hemodialysis, patients have an intraerythrocytic pH (pHi) and an extracellular pH, measured in whole blood (pHo), which are lower than those of healthy controls. During bicarbonate hemodialysis, pHi values continuously increase, approaching a normal value at the end of the session. Concomitantly, pHo values follow similar variations. During acetate hemodialysis, pHi values exhibit a steep initial decrease, reaching a minimum after about 15 minutes. Concurrently, however, pHo values decrease only slightly. This phenomenon seems to originate in the intraerythrocytic medium and might be due to a shift in intracellular CO2/bicarbonate equilibrium. This drop in pHi exhibits interpatient variability, suggesting that the magnitude of pH decrease would be correlated with the degree of the problems observed in some patients undergoing acetate hemodialysis

Mathematical morphology for grey-tone functions, structuring elements 2D and 3D, processor in video real-time

This work is dedicated to two new mathematical morphology algorithms. The first take over the "top hat transformation" but discriminate the grey topes . The second is general and develop the volumic structuring elements, the third dimension is the grey tone . A large part of this study is also reserved to develop a programmable mathematical morphology processor in video real time, it includes : 8 binary cells, 2 operators treating images with 64 grey tones and look-up tables for calculs .On présente 2 nouveaux algorithmes de morphologie mathématique. Le premier reprend la «transformation par chapeau haut de forme» en discriminant les niveaux de gris, le second concerne les éléments structurants volumiques, la troisième dimension est représentée par l'intensité lumineus

Smart sensing and multisensorial data fusion for road obstacle detection and tracking

In this article, we present a multisensorial solution for road obstacle detection and tracking . This solution is based on a mixe d camera/3D sensor mounted on the front of an experimental vehicle . The multisensor is described . The calibration step enables the matching of the heterogeneous data . Two capabalities of the senso r have been developped : the controlled perception making possible the acquisition of depth data in an area defined in the intensit y image; the visual servoing carrying out the focusing of the laser beam on a moving target detected in the intensity image . These two capabalities allow a Feedback control on the acquisition mode of the sensor according to the environment . ' The perception strategy is based on the selection of the best sensor for a given goal . The obstacle detection is based on th e segmentation and interpretation of depth data which are well suited in this context . However, the rate of acquisition of these dat a is too slow in order to extract the kinematic state of the obstacle . So, the tracking process is based on the collaboration betwee n intensity image processing which ensures the tracking itself and a 3D process which returns the obstacle model size to search in th e image. This algorithm of heterogeneous data fusion, associated with a Kalman filtering, permits to compute the state of obstacles . This work fits into the european project PROMETHEUS . Experimental results have been validated in real situation on the Prola b vehicle .Dans cet article, nous présentons une solution multisensorielle temps réel pour la détection et le suivi d'obstacles sur route. Cette solution est basée sur l'utilisation d'un capteur mixte caméra vidéo/capteur de profondeur placé à l'avant d'un véhicule expérimental. Le capteur multisensoriel est décrit. Le calibrage permet l'alignement des données hétérogènes. Deux facultés du capteur sont développées : la perception dirigée permet l'acquisition d'une image de profondeur dans une zone définie dans l'image de luminance ; l'asservissement visuel réalise la focalisation du faisceau laser sur un point de l'image de luminance. De façon générale, ces facultés permettent un contrôle par rétroaction sur le mode d'acquisition du capteur en fonction de la situation dans laquelle se trouve le système de perception. La stratégie de perception est basée sur la sélection du capteur adéquat pour un objectif donné. La détection d'obstacle repose sur la segmentation et l'interprétation des données de profondeur qui sont d'une grande pertinence dans ce contexte. En revanche, la cadence d'acquisition de ces données n'est pas suffisante si l'on souhaite dériver les caractéristiques cinématiques des obstacles. En conséquence, le suivi des obstacles combine un traitement de l'image de luminance rapide avec un traitement de l'information 3D. Le premier permet de réactualiser la position de l'obstacle afin d'asservir le faisceau laser sur celui-ci et le second assure la connaissance de la taille du modèle de l'obstacle à chercher dans l'image. Cet algorithme de fusion de données hétérogènes accompagné d'un filtrage de Kalman permet d'inférer les caractéristiques cinématiques des obstacles dont la connaissance est indispensable pour aborder ceux-ci dans de bonnes conditions. Ces recherches sont menées dans le cadre du projet européen PROMETHEUS et sont validées en situation réelle à bord du véhicule expérimental Prolab

Phase appearance or disappearance in two-phase flows

This paper is devoted to the treatment of specific numerical problems which appear when phase appearance or disappearance occurs in models of two-phase flows. Such models have crucial importance in many industrial areas such as nuclear power plant safety studies. In this paper, two outstanding problems are identified: first, the loss of hyperbolicity of the system when a phase appears or disappears and second, the lack of positivity of standard shock capturing schemes such as the Roe scheme. After an asymptotic study of the model, this paper proposes accurate and robust numerical methods adapted to the simulation of phase appearance or disappearance. Polynomial solvers are developed to avoid the use of eigenvectors which are needed in usual shock capturing schemes, and a method based on an adaptive numerical diffusion is designed to treat the positivity problems. An alternate method, based on the use of the hyperbolic tangent function instead of a polynomial, is also considered. Numerical results are presented which demonstrate the efficiency of the proposed solutions

Cryogenic SiPM arrays for the DUNE photon detection system

In this paper we report on the characterization of SiPM tiles developed for the R & D on the DUNE Photon Detection System. The tiles were produced by Fondazione Bruno Kessler (FBK) employing NUV-HD-SF SiPMs. Special emphasis is given on cryo-reliability of the sensors, i.e. the stability of electric and mechanical properties after thermal cycles at room and 77K temperature. The characterization includes the determination of the I-V curve, a high sensitivity measurement of Dark Count Rate at different overvoltages, and correlated noise. The single p.e. sensitivity is measured as a function of the number of sensors connected to a single electronic channel, after amplification at 77K using a dedicated cold amplifier.Comment: 17 pages, 10 figures, 4 table, submitted to NIM-

Rethinking the Gains from Immigration: Theory and Evidence from the U.S.

Recent influential empirical work has emphasized the negative impact immigrants have on the wages of U.S.-born workers, arguing that immigration harms less educated American workers in particular and all U.S.-born workers in general. Because U.S. and foreign born workers belong to different skill groups that are imperfectly substitutable, one needs to articulate a production function that aggregates different types of labor (and accounts for complementarity and substitution effects) in order to calculate the various effects of immigrant labor on U.S.-born labor. We introduce such a production function, making the crucial assumption that U.S. and foreign-born workers with similar education and experience levels may nevertheless be imperfectly substitutable, and allowing for endogenous capital accumulation. This function successfully accounts for the negative impact of the relative skill levels of immigrants on the relative wages of U.S. workers. However, contrary to the findings of previous literature, overall immigration generates a large positive effect on the average wages of U.S.-born workers. We show evidence of this positive effect by estimating the impact of immigration on both average wages and housing values across U.S. metropolitan areas (1970-2000). We also reproduce this positive effect by simulating the behavior of average wages and housing prices in an open city-economy, with optimizing U.S.-born agents who respond to an inflow of foreign-born workers of the size and composition comparable to the immigration of the 1990s

Ethnic Minorities Rewarded: Ethnostratification on the Wage Market in Belgium

Several previous researches have confirmed the hypothesis of ethnostratification, which holds that the labour market is divided into different ethnic layers. While people of a European origin are over-represented in the top layers (the primary market), people with non-European roots and/or nationalities are more concentrated in bottom layers (the secondary market). Relative to the primary market, this secondary market is characterized by a higher chance of unemployment, lower wages, poorer working conditions and greater job insecurity. This paper deals with a very important condition of work: the wage. Does origin have an impact on the level of wage? We make a distinction between nine origin groups: Belgians, North en West Europeans, South Europeans (from Greece, Spain, Portugal), Italians, East Europeans, Moroccans, Turks, Sub Sahara Africans and Asians. The first part of this article briefly describes the database used for the analyses and presents a few general figures for the total Belgian population. In the second part we examine the impact of origin on wage levels. For each origin group we will give an overview of the average daily wages and the partition over the wage classes. For the weaker populations, gender and age are taken into account. Finally, by means of a regression analysis, we will examine the influence of origin while controlling a few other variables that may influence the wage level

A Future for the Dead Sea Basin: Water Culture among Israelis, Palestinians and Jordanians

The Dead Sea basin plays a major role for regional economic development (industry, tourism and agriculture) in the Middle East. This potential is threatened by the steady disappearance of the Dead Sea. Since around 1930 the water level of the Dead Sea has fallen by about 25 m, about half of this alone in the last 20 years. The Dead Sea is a transboundary resource shared by Israel, the Palestinian Authority and Jordan. The Dead Sea is the terminal point of the Jordan River watershed and as such, it serves as a barometer for the health of the overall system. Its rapid decline reflects the present water management strategies of the riparian and upstream countries. This includes the different water cultures of the three countries. Throughout history, the Dead Sea basin has served as a source of refuge and inspiration for followers of Judaism, Christianity and Islam. Today, the religious significance of the Dead Sea is being overshadowed by its rapid disappearance. This may be explained in part by the water cultures of the three countries that influence water policy in the region. Ideology, together with culture and tradition, such as that of Zionism in Israel, has played a central role in water development in the region. In many cases, this has been at the expense of the environment. Elements pertaining to environmental security and water culture and tradition, whereby a sustainably managed environment provides for social, economic as well as environmental benefits are evident with regards the Dead Sea. The decline for example, undermines its potential as a tourist destination, despite the enormous investment in hotel and resort infrastructures in Israel and in Jordan. The decline also raises ethical issues about the exploitation of water resources by present generations at the expense of this natural heritage to future generations. This paper provides an analysis of a European Union funded project whose aims are to synthesize and assess existing physical and socio-economic data and to assess options for a better future for the Dead Sea. It will identify the patterns of water supply and use in the region, and the factors that control these patterns, including those of water culture. The underlying assumption is that solutions for a more sustainable development than todays scenario will not come from simply providing more water for more development, but from a new land and water management system, indeed ethic, that is sensitive to social, cultural and ecological resources thereby providing security and stability across cultures, economic sectors and nations