9 resultados para circle graph
em Université de Lausanne, Switzerland
Resumo:
Adolescent health surveys, like those for other segments of the population, tend to remain in the hands of researchers, where they can have no real impact on the way critical health issues are dealt with by policy makers or other professionals directly connected to young people in their everyday work. This paper reviews important issues concerning the dissemination of survey results among professionals from various fields. The content, length and wording of the messages should be tailored to the audience one wants to reach as well as the type of channels used for their diffusion. Survey data sets can be used to select priorities for interventions: ad hoc presentations, attractive summaries and brochures, or even films expressing young peoples' opinions have been used by European public health professionals to make data sets usable in various local, regional and national contexts. CONCLUSION: The impact of these diffusion strategies is, however, difficult to assess and needs to be refined. The adequate delivery of survey findings as well as advocacy and lobbying activities require specific skills which can be endorsed by specialized professionals. Ultimately, it is the researchers' responsibility to ensure that such tasks are effectively performed.
Resumo:
In this study we investigated the effect of medial temporal lobe epilepsy (MTLE) on the global characteristics of brain connectivity estimated by topological measures. We used DSI (Diffusion Spectrum Imaging) to construct a connectivity matrix where the nodes represents the anatomical ROIs and the edges are the connections between any pair of ROIs weighted by the mean GFA/FA values. A significant difference was found between the patient group vs control group in characteristic path length, clustering coefficient and small-worldness. This suggests that the MTLE network is less efficient compared to the network of the control group.
Resumo:
Schizophrenia is postulated to be the prototypical dysconnection disorder, in which hallucinations are the core symptom. Due to high heterogeneity in methodology across studies and the clinical phenotype, it remains unclear whether the structural brain dysconnection is global or focal and if clinical symptoms result from this dysconnection. In the present work, we attempt to clarify this issue by studying a population considered as a homogeneous genetic sub-type of schizophrenia, namely the 22q11.2 deletion syndrome (22q11.2DS). Cerebral MRIs were acquired for 46 patients and 48 age and gender matched controls (aged 6-26, respectively mean age = 15.20 ± 4.53 and 15.28 ± 4.35 years old). Using the Connectome mapper pipeline (connectomics.org) that combines structural and diffusion MRI, we created a whole brain network for each individual. Graph theory was used to quantify the global and local properties of the brain network organization for each participant. A global degree loss of 6% was found in patients' networks along with an increased Characteristic Path Length. After identifying and comparing hubs, a significant loss of degree in patients' hubs was found in 58% of the hubs. Based on Allen's brain network model for hallucinations, we explored the association between local efficiency and symptom severity. Negative correlations were found in the Broca's area (p < 0.004), the Wernicke area (p < 0.023) and a positive correlation was found in the dorsolateral prefrontal cortex (DLPFC) (p < 0.014). In line with the dysconnection findings in schizophrenia, our results provide preliminary evidence for a targeted alteration in the brain network hubs' organization in individuals with a genetic risk for schizophrenia. The study of specific disorganization in language, speech and thought regulation networks sharing similar network properties may help to understand their role in the hallucination mechanism.