Traitement de texte et stratégies rédactionnelles

The objective of this experimental observation is to show how the use of a standard word processor changes the writing strategies devised by advanced users during the production of short texts. Empirical research has indicated that word processors, in fact, have a negative impact on writing strategies. Analysis of the conditions under which "man-machine" dialogue takes place, has shown that screen size and linear management both have an effect on writing. Before determining the ways in which a word processor can disrupt common writing practices, we must gain a better understanding of how a text is actually composed in real time, with or without a computer. Although the various writing processes have been clearly identified, the functional scenario describing the succession of writing phases and accompagnying activities is still poorly defined. The marks produced by writers on paper, whether linguistic (words, sentence fragments, sentences) or non-linguistic (arrows, underlining, indexation, diagrams, etc.), reflect the planning, translating, and revising processes being carried out by the writer. Sharples and Pemberton (1990) describe the exact functions of these marks in the elaboration of the ideas to be translated into text form (levels of organization). However, more knowledge about their frequency of use at the different stages of text composition is required. This is one of the goals of the present experimental observation. For the most part, such marks cannot be displayed and manipulated on the screen of a standard word processor as they can on paper. It is therefore crucial that we observe the means employed by writers to adapt their use of these necessary devices to word processing. The main results indicate that writers who use a word processor still resort to "pencil and paper" for the initial planning. The small amount of text preparation done by computer users (manifested by chronological and hierarchical organization marks) compared to writers who produce without a word processor is compensated by extensive revision on the screen. However, while writing strategies are highly dependent on production conditions, the quality of the texts produced does not vary significantly. The possibility of eliminating one of the important drawbacks of computer-assisted writing i. e. the fact that the information must be displayed linearly on the screen, is currently being studied by designers of planning aids that accompagny word processors. Before such aids can actually be developed, however, more knowledge is needed of the phases of writing and the marks used by writers throughout the production process

Monitoring long-term evolution of engineered barrier systems using magnets:Magnetic response

International audienc

Magnetic and crystal structures of the magnetoelectric pyroxene LiCrSi2O6

International audienceWe investigated the magnetic and crystal structures of the recent reported magnetoelectric system LiCrSi2O6 by powder neutron diffraction. Below TN=11.5 K, an antiferromagnetic order appears. It is characterized by an antiferromagnetic coupling within the CrO6 octahedra chains and a ferromagnetic coupling between the chains. The magnetic order is commensurate with the lattice with k=0. The associated magnetic space group is P21 /c. This symmetry is in agreement with the reported magnetoelectric effect. We show that the magnetic frustration in this system is small. Finally, we discuss our results using a Landau phenomenological model and in the light of the literature

Utilization of a deoxynucleoside diphosphate substrate by HIV reverse transcriptase

Background: Deoxynucleoside triphosphates (dNTPs) are the normal substrates for DNA sysnthesis is catalyzed by polymerases such as HIV-1 reverse transcriptase (RT). However, substantial amounts of deoxynucleoside diphosphates (dNDPs) are also present in the cell. Use of dNDPs in HIV-1 DNA sysnthesis could have significant implications for the efficacy of nucleoside RT inhibitors such as AZT which are first line therapeutics fro treatment of HIV infection. Our earlier work on HIV-1 reverse transcriptase (RT) suggested that the interaction between the γ phosphate of the incoming dNTP and RT residue K65 in the active site is not essential for dNTP insertion, implying that this polymerase may be able to insert dNPs in addition to dNTPs. Methodology/Principal Findings: We examined the ability of recombinant wild type (wt) and mutant RTs with substitutions at residue K65 to utilize a dNDP substrate in primer extension reactions. We found that wild type HIV-1 RT indeed catalyzes incorporation of dNDP substrates whereas RT with mutations of residue K645 were unable to catalyze this reaction. Wild type HIV-1 RT also catalyzed the reverse reaction, inorganic phosphate-dependent phosphorolysis. Nucleotide-mediated phosphorolytic removal of chain-terminating 3′-terminal nucleoside inhibitors such as AZT forms the basis of HIV-1 resistance to such drugs, and this removal is enhanced by thymidine analog mutations (TAMs). We found that both wt and TAM-containing RTs were able to catalyze Pi-mediated phosphorolysis of 3′-terminal AZT at physiological levels of Pi with an efficacy similar to that for ATP-dependent AZT-excision. Conclusion: We have identified two new catalytic function of HIV-1 RT, the use of dNDPs as substrates for DNA synthesis, and the use of Pi as substrate for phosphorolytic removal of primer 3′-terminal nucleotides. The ability to insert dNDPs has been documented for only one other DNA polymerase The RB69 DNA polymerase and the reverse reaction employing inorganic phosphate has not been documented for any DNA polymerase. Importantly, our results show that Pi-mediated phosphorolysis can contribute to AZT resistance and indicates that factors that influence HIV resistance to AZT are more complex than previously appreciated. © 2008 Garforth et al

Rapport préliminaire sur les activités de la mission archéologique franco-syrienne dans la micro-région d'Al-Rawda (Shamiyeh) : quatrième et cinquième campagnes (2005 et 2006)

This preliminary report presents the results of two campaigns of excavation and survey in 2005and 2006 on the site of AI-Rawda (West-Central Syria) and in the micro-region of 100 km2 around it. Thesite is a pre-planned circular new town. It was founded around 2400 BCE, in the steppe zone and was inhabitedonly during EB IV, until the end of the 3rd millennium. The work of 2005 and 2006 involved furtherextensive excavation of a sanctuary consisting of two temples and a temenos togeiher with aIl associatedinstallations (including a betyl in situ). The eastem gate of the town was excavated and four lines of defencehave been identified. A stratigraphie sounding in the southwest clarifies the origin of the town. In the necropolisassociated with the site, the excavation of a collective pit burial is presented. Intensive survey wascontinued outside the ancient town, with particular attention to sites that were occupied at the same time asAI-Rawda, to burials, which have been classified by type, and to installations that can be linked to agricultureor pastoralism. This work was supplemented by archaeobotanical, archaeozoological and geo-archaeologicalresearch, as weIl as a study of the environment.Ce rapport préliminaire présente les résultats de deux campagnes de fouilles et de prospection conduites en 2005 et 2006 sur le site d’Al-Rawda (Syrie du centre-ouest) et dans la microrégion de 100 km2 qui l’entoure. Le site, une ville neuve circulaire au plan d’urbanisme préconçu fondé vers 2500 av. J.-C., se trouve en zone steppique. Il n’est habité que durant le Bronze ancien IV, jusqu’à la fin du 3e millénaire.Les travaux en 2005 et 2006 ont porté sur la poursuite du dégagement extensif d’un sanctuaire qui regroupe deux temples et un temenos, avec l’ensemble des installations qu’ils contiennent (dont un bétyle in situ). À l’est, a été mise au jour la porte orientale de la ville tandis que quatre lignes de défense ont été identifiées. Un sondage stratigraphique au sud-ouest éclaire l’origine de la ville. Dans la nécropole associée au site, la fouille d’une tombe en puits collective est présentée.Parallèlement, la prospection intensive autour de la ville antique a été poursuivie en mettant l’accent sur les sites d’habitat contemporains d’Al-Rawda, les tombes caractérisées par type et les aménagements qui peuvent être liés à une mise en valeur agricole du territoire et au pastoralisme. Ces travaux ont été complétés par des études archéobotanique, archéozoologique, géoarchéologique et par une étude des milieux

Functional Polymorphisms in IL13 Are Protective against High Schistosoma mansoni Infection Intensity in a Brazilian Population

IL-13 is a signature cytokine of the helper T cell type 2 (TH2) pathway which underlies host defense to helminthic infection and activates production of IgE in both parasitized populations and in urban settings after allergen exposure.Two functional polymorphisms in IL13, rs1800925 (or c.1-1111C>T) and rs20541 (or R130Q) were previously found to be associated with Schistosoma hematobium infection intensity. They have not been thoroughly explored in S. mansoni-endemic populations, however, and were selected along with 5 tagging SNPs for genotyping in 812 individuals in 318 nuclear families from a schistosomiasis-endemic area of Conde, Bahia, in Brazil. Regression models using GEE to account for family membership and family-based quantitative transmission disequilibrium tests (QTDT) were used to evaluate associations with total serum IgE (tIgE) levels and S. mansoni fecal egg counts adjusted for non-genetic covariates. We identified a protective effect for the T allele at rs20541 (P = 0.005) against high S. mansoni egg counts, corroborated by QTDT (P = 0.014). Our findings also suggested evidence for protective effects for the T allele at rs1800925 and A allele at rs2066960 after GEE analysis only (P = 0.050, 0.0002).The two functional variants in IL13 are protective against high S. mansoni egg counts. These markers showed no evidence of association with tIgE levels, unlike tIgE levels previously studied in non-parasitized or atopic study populations

Estrogen Prevents Oxidative Damage to the Mitochondria in Friedreich's Ataxia Skin Fibroblasts

Estrogen and estrogen-related compounds have been shown to have very potent cytoprotective properties in a wide range of disease models, including an in vitro model of Friedreich's ataxia (FRDA). This study describes a potential estrogen receptor (ER)-independent mechanism by which estrogens act to protect human FRDA skin fibroblasts from a BSO-induced oxidative insult resulting from inhibition of de novo glutathione (GSH) synthesis. We demonstrate that phenolic estrogens, independent of any known ER, are able to prevent lipid peroxidation and mitochondrial membrane potential (ΔΨm) collapse, maintain ATP at near control levels, increase oxidative phosphorylation and maintain activity of aconitase. Estrogens did not, however, prevent BSO from depleting GSH or induce an increased expression level of GSH. The cytoprotective effects of estrogen appear to be due to a direct overall reduction in oxidative damage to the mitochondria, enabling the FRDA fibroblast mitochondria to generate sufficient ATP for energy requirements and better survive oxidative stress. These data support the hypothesis that phenol ring containing estrogens are possible candidate drugs for the delay and/or prevention of FRDA symptoms

Global Policy Barriers and Enablers to Exercise and Physical Activity in Kidney Care

Objective: Impairment in physical function and physical performance leads to decreased independence and health-related quality of life in people living with chronic kidney disease and end-stage kidney disease. Physical activity and exercise in kidney care are not priorities in policy development. We aimed to identify global policy-related enablers, barriers, and strategies to increase exercise participation and physical activity behavior for people living with kidney disease. Design and Methods: Guided by the Behavior Change Wheel theoretical framework, 50 global renal exercise experts developed policy barriers and enablers to exercise program implementation and physical activity promotion in kidney care. The consensus process consisted of developing themes from renal experts from North America, South America, Continental Europe, United Kingdom, Asia, and Oceania. Strategies to address enablers and barriers were identified by the group, and consensus was achieved. Results: We found that policies addressing funding, service provision, legislation, regulations, guidelines, the environment, communication, and marketing are required to support people with kidney disease to be physically active, participate in exercise, and improve health-related quality of life. We provide a global perspective and highlight Japanese, Canadian, and other regional examples where policies have been developed to increase renal physical activity and rehabilitation. We present recommendations targeting multiple stakeholders including nephrologists, nurses, allied health clinicians, organizations providing renal care and education, and renal program funders. Conclusions: We strongly recommend the nephrology community and people living with kidney disease take action to change policy now, rather than idly waiting for indisputable clinical trial evidence that increasing physical activity, strength, fitness, and function improves the lives of people living with kidney disease