DREW : Un outil Internet pour créer des situations d'apprentissage coopérant

http://archiveseiah.univ-lemans.fr/EIAH2003/Pdf_annexes/Corbel.pdfNational audienceDREW1 (Dialogical Reasoning Educational Web tool) est un environnement informatisé d'apprentissage humain collaboratif, développé en Java. Cet environnement est développé dans le cadre du projet européen SCALE2 (IST-1999) dont l'objectif pédagogique est de favoriser un apprentissage collaboratif basé sur l'argumentation (CABLE). En d'autres mots, l'objectif est d'amener les élèves du secondaire à " apprendre à travers des activités argumentatives ". Pour cela, à partir de l'environnement d'apprentissage DREW, différentes séquences d'enseignement et outils ont été conçus pour aider les élèves à acquérir, raffiner et étendre leur connaissance argumentative dans un domaine donné (le débat sur les OGM). Dans ce papier, nous nous limitons à présenter l'interface des outils élève (outils de communication et construction collaborative) et l'interface enseignant/chercheur proposées dans l'environnement (rejoueur d'interaction et outil de conception de tâches), puis les caractéristiques du système. Nous donnerons quelques propositions d'utilisation de ces outils dans le cadre d'activités pédagogiques

Next generation sequencing sheds light on the natural history of hepatitis C infection in patients that fail treatment

Background and rationale of the study: High rates of sexually-transmitted infection and reinfection with hepatitis C (HCV) have recently been reported in HIV-infected men who have sex with men and reinfection has also been described in monoinfected injecting drug users. The diagnosis of reinfection has traditionally been based on direct Sanger sequencing of samples pre and post-treatment, but not on more sensitive deep sequencing techniques. We studied viral quasispecies dynamics in patients who failed standard of care therapy in a high-risk HIV-infected cohort of patients with early HCV infection to determine whether treatment failure was associated with reinfection or recrudescence of pre-existing infection. Paired sequences (pre- and post- treatment) were analysed. The HCV E2 hypervariable region-1 was amplified using nested RT-PCR with indexed genotype-specific primers and the same products were sequenced using both Sanger and 454 pyrosequencing approaches. Results: Of 99 HIV-infected patients with acute HCV treated with 24-48 weeks of pegylated interferon alpha and ribavirin, 15 failed to achieve a sustained virological response (6 relapsed, 6 had a null response and 3 had a partial response). Using direct sequencing, 10/15 patients (66%) had evidence of a previously undetected strain post-treatment; in many studies, this is interpreted as reinfection. However, pyrosequencing revealed that 15/15 (100%) of patients had evidence of persisting infection. 6/15 (40%) patients had evidence of a previously undetected variant present in the post-treatment sample in addition to a variant that was detected at baseline. This could represent superinfection or a limitation of the sensitivity of pyrosequencing. Conclusion: In this high-risk group, the emergence of new viral strains following treatment failure is most commonly associated with emerging dominance of pre-existing minority variants rather than re-infection. Superinfection may occur in this cohort but reinfection is over-estimated by Sanger sequencing. (Hepatology 2014;

Bis(μ-carboxyl­atoethyl­phospho­nato)bis­[aqua­(2,2′-bipyridine)manganese(II)]

The title compound, [Mn2(HO3PCH2CH2COO)2(C8H8N2)2(H2O)2], was obtained by hydro­thermal synthesis. The manganese(II) ions are six-coordinate and are linked by two 2-carboxy­ethyl­phospho­nate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid distance 4.2754 (4) Å]

Poly[[diaqua-μ6-succinato-di-μ5-succinato-didysprosium(III)] mono­hydrate]

The title compound, {[Dy2(C4H4O4)3(H2O)2]·H2O}n, is isostructural with other lanthanide succinates of the same formula. The DyIII atom is nine-coordinated in a tricapped trigonal–prismatic environment by eight O atoms, derived from six carboxyl­ate groups and a water mol­ecule. One of the independent succinate anions is located about a crystallographic inversion center and the uncoordinated water mol­ecule lies on a twofold axis. The crystal structure comprises edge-shared DyO9 polyhedra linked by succinate bridges, forming a three-dimensional network architecture. Intra- and inter­molecular O—H⋯O hydrogen bonds are present in the crystal structure

Eighth Major Clade for Hepatitis Delta Virus

Hepatitis delta virus is the only representative of the Deltavirus genus, which consists of 7 differentiated major clades. In this study, an eighth clade was identified from 3 distinct strains. Deltavirus genetic variability should be considered for diagnostic purposes. Clinical consequences of the diversity have yet to be evaluated

Stepwise changes in viable but nonculturable Vibrio cholerae cells

Many bacterial species are known to become viable but nonculturable (VBNC) under conditions that are unsuitable for growth. In this study, the requirements for resuscitation of VBNC-state Vibrio cholerae cells were found to change over time. Although VBNC cells could initially be converted to culturable by treatment with catalase or HT-29 cell extract, they subsequently entered a state that was not convertible to culturable by these factors. However, fluorescence microscopy revealed the presence of live cells in this state, from which VBNC cells were resuscitated by co-cultivation with HT-29 human colon adenocarcinoma cells. Ultimately, all cells entered a state from which they could not be resuscitated, even by co-cultivation with HT-29. These characteristic changes in VBNC-state cells were a common feature of strains in both V. cholerae O1 and O139 serogroups. Thus, the VBNC state of V. cholerae is not a single property but continues to change over time

Acute hepatitis C: Current status and remaining challenges

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Gaining Greater Insight into HCV Emergence in HIV-Infected Men Who Have Sex with Men: The HEPAIG Study

OBJECTIVES: The HEPAIG study was conducted to better understand Hepatitis C virus (HCV) transmission among human immuno-deficiency (HIV)-infected men who have sex with men (MSM) and assess incidence of HCV infection among this population in France. METHODS AND RESULTS: Acute HCV infection defined by anti-HCV or HCV ribonucleic acid (RNA) positivity within one year of documented anti-HCV negativity was notified among HIV-infected MSM followed up in HIV/AIDS clinics from a nationwide sampling frame. HIV and HCV infection characteristics, HCV potential exposures and sexual behaviour were collected by the physicians and via self-administered questionnaires. Phylogenetic analysis of the HCV-NS5B region was conducted. HCV incidence was 48/10 000 [95% Confidence Interval (CI):43-54] and 36/10 000 [95% CI: 30-42] in 2006 and 2007, respectively. Among the 80 men enrolled (median age: 40 years), 55% were HIV-diagnosed before 2000, 56% had at least one sexually transmitted infection in the year before HCV diagnosis; 55% were HCV-infected with genotype 4 (15 men in one 4d-cluster), 32.5% with genotype 1 (three 1a-clusters); five men were HCV re-infected; in the six-month preceding HCV diagnosis, 92% reported having casual sexual partners sought online (75.5%) and at sex venues (79%), unprotected anal sex (90%) and fisting (65%); using recreational drugs (62%) and bleeding during sex (55%). CONCLUSIONS: This study emphasizes the role of multiple unprotected sexual practices and recreational drugs use during sex in the HCV emergence in HIV-infected MSM. It becomes essential to adapt prevention strategies and inform HIV-infected MSM with recent acute HCV infection on risk of re-infection and on risk-reduction strategies

Brettanomyces bruxellensis yeasts: impact on wine and winemaking

Yeasts belonging to the Brettanomyces/Dekkera genus are non-conventional yeasts, which affect winemaking by causing wine spoilage all over the world. This mini-review focuses on recent results concerning the presence of Brettanomyces bruxellensis throughout the wine processing chain. Here, culture-dependent and independent methods to detect this yeast on grapes and at the very early stage of wine production are encompassed. Chemical, physical and biological tools, devised for the prevention and control of such a detrimental species during winemaking are also presented. Finally, the mini-review identifies future research areas relevant to the improvement of wine safety and sensory profiles

Trouble with Bleeding: Risk Factors for Acute Hepatitis C among HIV-Positive Gay Men from Germany—A Case-Control Study

OBJECTIVES: To identify risk factors for hepatitis C among HIV-positive men who have sex with men (MSM), focusing on potential sexual, nosocomial, and other non-sexual determinants. BACKGROUND: Outbreaks of hepatitis C virus (HCV) infections among HIV-positive MSM have been reported by clinicians in post-industrialized countries since 2000. The sexual acquisition of HCV by gay men who are HIV positive is not, however, fully understood. METHODS: Between 2006 and 2008, a case-control study was embedded into a behavioural survey of MSM in Germany. Cases were HIV-positive and acutely HCV-co-infected, with no history of injection drug use. HIV-positive MSM without known HCV infection, matched for age group, served as controls. The HCV-serostatus of controls was assessed by serological testing of dried blood specimens. Univariable and multivariable regression analyses were used to identify factors independently associated with HCV-co-infection. RESULTS: 34 cases and 67 controls were included. Sex-associated rectal bleeding, receptive fisting and snorting cocaine/amphetamines, combined with group sex, were independently associated with case status. Among cases, surgical interventions overlapped with sex-associated rectal bleeding. CONCLUSIONS: Sexual practices leading to rectal bleeding, and snorting drugs in settings of increased HCV-prevalence are risk factors for acute hepatitis C. We suggest that sharing snorting equipment as well as sharing sexual partners might be modes of sexual transmission. Condoms and gloves may not provide adequate protection if they are contaminated with blood. Public health interventions for HIV-positive gay men should address the role of blood in sexual risk behaviour. Further research is needed into the interplay of proctosurgery and sex-associated rectal bleeding