L’utilisation des réseaux sociaux (Snapchat, WhatsApp et Instagram) et le cyberbullying

100% des jeunes possèdent un téléphone portable, 99% ont un ordinateur et 97% ont accès à Internet (Waller et al., 2016). Ces nouveaux moyens technologiques font partie de notre quotidien. Depuis l’apparition de ces réseaux, un nouveau mouvement est né : le cyberbullying. Ce harcèlement par Internet consiste à l’utilisation de technologies modernes de communication afin de nuire aux autres de manière délibérée et agressive. Quand les jeunes arrivent en classe, ils apportent avec eux l’entier de leur vécu quotidien, familial ou encore émotionnel. Les problèmes liés à l’utilisation massive de ces réseaux font partie de notre quotidien d’enseignant. Malheureusement, les études faites jusqu’au jour d’aujourd’hui portent en majeure partie sur les élèves entre 13 ans et plus. Mais qu’en est-il des jeunes âgés entre 9 et 12 ans ? Notre travail de recherche porte donc sur l’utilisation des réseaux sociaux (Snapchat, Instagram et WhatsApp) et le cyberbullying. Deux outils différents ont été utilisés lors de cette recherche : des questionnaires afin d’avoir des résultats quantitatifs et deux entretiens afin d’avoir un point de vue qualitatif. Nos résultats montrent que WhatsApp est le réseau social le plus utilisé, suivi d’Instagram en deuxième position et finalement de Snapchat. Les élèves considèrent le nombre de dangers et de conflits sur les réseaux comme très faibles. Ils avouent tout de même donner plus d’informations personnelles sur WhatsApp que sur les autres réseaux choisis dans l’étude. Concernant leur vision du contrôle des parents, ils l’estiment très faible. Cependant, il s’agit uniquement de leur avis, il serait intéressant de savoir la réalité des faits en interrogeant les parents. Les deux sujets interrogés savent définir le cyberbullying et connaissent les différents acteurs agissant au sein de cette forme de harcèlement. Ils sont également conscients des différents risques, conséquences ou sentiments que peut ressentir une cyber-victime mais n’abordent pas du tout ceux concernant le témoin ou le cyber-harceleur. En conclusion, notre recherche montre que les réseaux sociaux font partie intégrante du quotidien d’un grand nombre d’élèves. Il est donc essentiel que les enseignants s’interrogent sur les moyens de gérer les problèmes que ceux-ci peuvent amener en classe mais également les moyens de les éviter

The association between genetic variants in hMLH1 and hMSH2 and the development of sporadic colorectal cancer in the Danish population

<p>Abstract</p> <p>Background</p> <p>Mutations in the mismatch repair genes <it>hMLH1 </it>and <it>hMSH2 </it>predispose to hereditary non-polyposis colorectal cancer (HNPCC). Genetic screening of more than 350 Danish patients with colorectal cancer (CRC) has led to the identification of several new genetic variants (e.g. missense, silent and non-coding) in <it>hMLH1 </it>and <it>hMSH2</it>. The aim of the present study was to investigate the frequency of these variants in <it>hMLH1 </it>and <it>hMSH2 </it>in Danish patients with sporadic colorectal cancer and in the healthy background population. The purpose was to reveal if any of the common variants lead to increased susceptibility to colorectal cancer.</p> <p>Methods</p> <p>Associations between genetic variants in <it>hMLH1 </it>and <it>hMSH2 </it>and sporadic colorectal cancer were evaluated using a case-cohort design. The genotyping was performed on DNA isolated from blood from the 380 cases with sporadic colorectal cancer and a sub-cohort of 770 individuals. The DNA samples were analyzed using Single Base Extension (SBE) Tag-arrays. A Bonferroni corrected Fisher exact test was used to test for association between the genotypes of each variant and colorectal cancer. Linkage disequilibrium (LD) was investigated using HaploView (v3.31).</p> <p>Results</p> <p>Heterozygous and homozygous changes were detected in 13 of 35 analyzed variants. Two variants showed a borderline association with colorectal cancer, whereas the remaining variants demonstrated no association. Furthermore, the genomic regions covering <it>hMLH1 </it>and <it>hMSH2 </it>displayed high linkage disequilibrium in the Danish population. Twenty-two variants were neither detected in the cases with sporadic colorectal cancer nor in the sub-cohort. Some of these rare variants have been classified either as pathogenic mutations or as neutral variants in other populations and some are unclassified Danish variants.</p> <p>Conclusion</p> <p>None of the variants in <it>hMLH1 </it>and <it>hMSH2 </it>analyzed in the present study were highly associated with colorectal cancer in the Danish population. High linkage disequilibrium in the genomic regions covering <it>hMLH1 </it>and <it>hMSH2</it>, indicate that common genetic variants in the two genes in general are not involved in the development of sporadic colorectal cancer. Nevertheless, some of the rare unclassified variants in <it>hMLH1 </it>and <it>hMSH2 </it>might be involved in the development of colorectal cancer in the families where they were originally identified.</p

DFI-seq identification of environment-specific gene expression in uropathogenic Escherichia coli

Abstract Background During infection of the urinary tract, uropathogenic Escherichia coli (UPEC) are exposed to different environments, such as human urine and the intracellular environments of bladder epithelial cells. Each environment elicits a distinct bacterial environment-specific transcriptional response. We combined differential fluorescence induction (DFI) with next-generation sequencing, collectively termed DFI-seq, to identify differentially expressed genes in UPEC strain UTI89 during growth in human urine and bladder cells. Results DFI-seq eliminates the need for iterative cell sorting of the bacterial library and yields a genome-wide view of gene expression. By analysing the gene expression of UPEC in human urine we found that genes involved in amino acid biosynthesis were upregulated. Deletion mutants lacking genes involved in arginine biosynthesis were outcompeted by the wild type during growth in human urine and inhibited in their ability to invade or proliferate in the J82 bladder epithelial cell line. Furthermore, DFI-seq was used to identify genes involved in invasion of J82 bladder epithelial cells. 56 genes were identified to be differentially expressed of which almost 60% encoded hypothetical proteins. One such gene UTI89_C5139, displayed increased adhesion and invasion of J82 cells when deleted from UPEC strain UTI89. Conclusions We demonstrate the usefulness of DFI-seq for identification of genes required for optimal growth of UPEC in human urine, as well as potential virulence genes upregulated during infection of bladder cell culture. DFI-seq holds potential for the study of bacterial gene expression in live-animal infection systems. By linking fitness genes, such as those genes involved in amino acid biosynthesis, to virulence, this study contributes to our understanding of UPEC pathophysiology