Une nouvelle approche pour la gestion de flux temps réels basée sur l'algorithme EDF

Pour répondre aux exigences temporelles de flux temps réels, beaucoup de techniques d'ordonnancement de paquets ont été proposées dans la littérature, pour être utilisées au niveau de routeurs IP. La technique utilisant l'algorithme EDF a attiré une attention particulière, car l'optimalité de cet algorithme a été prouvée pour un nombre important de critères. Cependant la complexité et le surcoût induits par l'algorithme EDF ont constitué toujours un handicap majeur empêchant son implémentation. Dans ce papier, nous proposons une nouvelle approche d'ordonnancement, dite hybride, qui permet de combiner la puissance de EDF et la simplicité de l'algorithme standard FIFO. l'approche proposée a une complexité beaucoup plus réduite que celle de EDF. Les résultats de simulation soulignent l'efficacité de cette approche hybride

Comparison between Visibility and Diffraction Criteria on SIF and �-Integral Value for Mode � Crack Using RKPM

Recently, mesh-free methods are increasingly utilized in solving various types of boundary value problems. Much research has been done on mesh-free methods for solving differential equation problems including crack and also obtained satisfactory results. Among these methods, reproducing kernel particle method (RKPM) has been used increasingly in fracture mechanic problems. The �-integral and the stress intensity factor (SIF) are the most important parameters for crack problems. In this study �-integral has been used to calculate the SIF in the crack tip. The mode � SIF at the crack tip in a work-hardening material is obtained for various dilation parameters using RKPM. A comparison between two conventional treatments, visibility and diffraction on SIF and �-integral value, is conducted. Visibility and diffractionmethods increase the accuracy of RKPM results and effect on the �-integral results at the crack tip. In comparing between the visibility and diffraction methods to modify the shape functions, the diffraction criterion seems to have better results for the �-integral and SIF value

Cloning, expression and purification of the general stress protein Yhbo from Escherichia coli.

We cloned, expressed and purified the Escherichia coli yhbO gene product, which is homolog to the Bacillus subtilis general stress protein 18 (the yfkM gene product), the Pyrococcus furiosus intracellular protease PfpI, and the human Parkinson disease protein DJ-1. The gene coding for YhbO was generated by amplifying the yhbO gene from E. coli by polymerase chain reaction. It was inserted in the expression plasmid pET-21a, under the transcriptional control of the bacteriophage T7 promoter and lac operator. A BL21(DE3) E. coli strain transformed with the YhbO-expression vector pET-21a-yhbO, accumulates large amounts of a soluble protein of 20 kDa in SDS-PAGE that matches the expected YhbO molecular weight. YhbO was purified to homogeneity by HPLC DEAE ion exchange chromatography and hydroxylapatite chromatography and its identity was confirmed by N-terminal sequencing and mass spectrometry analysis. The native protein exists in monomeric, trimeric and hexameric forms

The effect of indentation force and displacement on visual perception of compliance

This paper investigates the effect of maximum indentation force and depth on people's ability to accurately discriminate compliance using indirect visual information only. Participants took part in two psychophysical experiments in which they were asked to choose the 'softest' sample out of a series of presented sample pairs. In the experiments, participants observed a computer-actuated tip indent the sample pairs to one of two conditions; maximum depth (10mm) or maximum force (4N). This indentation process simulates tool operated palpation in laparoscopic surgery. Results were used to plot psychometric functions as a measure of accuracy of compliance discriminability. A comparison indicated that participants performed best in the task where they judged samples being indented to a pre-set maximum force relying solely on visual cues, which demonstrates the effect of visual information on compliance discrimination. Results also show that indentation cues such as force and deformation depth have different effects on our ability to visually discriminate compliance. These findings will inform future work on designing a haptic feedback system capable of augmenting visual and haptic information independently for optimal compliance discrimination performance

The Escherichia coli thioredoxin homolog YbbN/Trxsc is a chaperone and a weak protein oxidoreductase.

Escherichia coli contains two thioredoxins, Trx1 and Trx2, and a thioredoxin-like protein, YbbN, which presents a strong homology in its N-terminal part with thioredoxin 1 and 2. YbbN, however, does not possess the canonical Cys-x-x-Cys active site of thioredoxins, but instead a Ser-x-x-Cys site. In addition to Cys-38, located in the SxxC site, it contains a second cysteine, Cys-63, close to Cys-38 in the 3D model. Cys-38 and Cys-63 undergo an oxidoreduction process, suggesting that YbbN functions with two redox cysteines. Accordingly, YbbN catalyzes the oxidation of reduced RNase and the isomerization of scrambled RNase. Moreover, upon oxidation, its oligomeric state changes from dimers to tetramers and higher oligomers. YbbN also possesses chaperone properties, promoting protein folding after urea denaturation and forming complexes with unfolded proteins. This is the first biochemical characterization of a member of the YbbN class of bacterial thioredoxin-like proteins, and in vivo experiments will allow to determine the importance of its redox and chaperone properties in the cellular physiology

EPQ Model with Imperfect Quality Raw Material

MSC 2010: 26A33, 33E12, 33C60, 44A20The classical economic production model (EPQ) has been extended in many directions to incorporate factors encountered in real-life situations. In this paper, an EPQ model that accounts for the cost of raw material needed for production is examined. It is assumed that the raw material acquired from the supplier contains a percentage of imperfect quality items. At the beginning of the inventory cycle, the raw material is received instantaneously, and a 100% screening process for detecting the imperfect quality items is conducted. Two different scenarios are considered. In the first, the imperfect quality items of the raw material are sold at a discounted price at the end of the screening period. In the second scenario, the imperfect quality items are kept in stock until the end of the inventory cycle and returned to the supplier when the next order is received

Partitioning a graph into disjoint cliques and a triangle-free graph

A graph G=(V,E) is partitionable if there exists a partition {A,B} of V such that A induces a disjoint union of cliques (i.e., G[A] is P_3-free) and B induces a triangle-free graph (i.e., G[B] is K_3-free). In this paper we investigate the computational complexity of deciding whether a graph is partitionable. The problem is known to be NP-complete on arbitrary graphs. Here it is proved that if a graph G is bull-free, planar, perfect, K_4-free or does not contain certain holes then deciding whether G is partitionable is NP-complete. This answers an open question posed by Thomassé, Trotignon and Vušković. In contrast a finite list of forbidden induced subgraphs is given for partitionable cographs

Amino Acid Requirements in Critically Ill Patients with Acute Kidney Injury Treated with Continuous Renal Replacement Therapy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90284/1/phco.28.5.600.pd

Working sick and out of sorts: a cross-cultural approach on presenteeism climate, organizational justice and work-family conflict

A climate of presenteeism has important effects on employee well-being and the organization itself. Our study, based on surveys of health sector employees in six different countries (Brazil, Ecuador, Lebanon, Portugal, Russia and Spain) examines whether organizational justice plays a mediating role in the relationship between a presenteeism climate in the organization and work-family conflict (WFC). Our results indicate that the perception of organizational justice and the presenteeism climate do influence WFC. Moreover, higher levels of WFC were found in non-Latin countries. This study contributes to the work attendance and life balance field by providing cross-cultural empirical evidence corroborating the effect of justice and presenteeism climate on the WFC

Modeling circadian clock-cell cycle interaction effects on cell population growth rates

Accepted for publication in Journal of Theoretical Biology, post-print versionInternational audienceThe circadian clock and the cell cycle are two tightly coupled oscillators. Recent analytical studies have shown counter-intuitive effects of circadian gating of the cell cycle on growth rates of proliferating cells which cannot be explained by a molecular model or a population model alone. In this work, we present a combined molecular-population model that studies how coupling the circadian clock to the cell cycle, through the protein WEE1, affects a proliferating cell population. We show that the cell cycle can entrain to the circadian clock with different rational period ratios and characterize multiple domains of entrainment. We show that coupling increases the growth rate for autonomous periods of the cell cycle around 24 h and above 48 h. We study the effect of mutation of circadian genes on the growth rate of cells and show that disruption of the circadian clock can lead to abnormal proliferation. Particularly, we show that $\mathit{Cry1}$, $\mathit{Cry2}$ mutations decrease the growth rate of cells, $\mathit{Per2}$ mutation enhances it and $\mathit{Bmal1}$ knockout increases it for autonomous periods of the cell cycle less than 21 h and decreases it elsewhere. Combining a molecular model to a population model offers new insight on the influence of the circadian clock on the growth of a cell population. This can help chronotherapy which takes benefits of physiological rhythms to improve anti-cancer efficacy and tolerance to drugs by administering treatments at a specific time of the day