Frontal networks in adults with autism spectrum disorder

It has been postulated that autism spectrum disorder is underpinned by an ‘atypical connectivity’ involving higher-order association brain regions. To test this hypothesis in a large cohort of adults with autism spectrum disorder we compared the white matter networks of 61 adult males with autism spectrum disorder and 61 neurotypical controls, using two complementary approaches to diffusion tensor magnetic resonance imaging. First, we applied tract-based spatial statistics, a ‘whole brain’ non-hypothesis driven method, to identify differences in white matter networks in adults with autism spectrum disorder. Following this we used a tract-specific analysis, based on tractography, to carry out a more detailed analysis of individual tracts identified by tract-based spatial statistics. Finally, within the autism spectrum disorder group, we studied the relationship between diffusion measures and autistic symptom severity. Tract-based spatial statistics revealed that autism spectrum disorder was associated with significantly reduced fractional anisotropy in regions that included frontal lobe pathways. Tractography analysis of these specific pathways showed increased mean and perpendicular diffusivity, and reduced number of streamlines in the anterior and long segments of the arcuate fasciculus, cingulum and uncinate—predominantly in the left hemisphere. Abnormalities were also evident in the anterior portions of the corpus callosum connecting left and right frontal lobes. The degree of microstructural alteration of the arcuate and uncinate fasciculi was associated with severity of symptoms in language and social reciprocity in childhood. Our results indicated that autism spectrum disorder is a developmental condition associated with abnormal connectivity of the frontal lobes. Furthermore our findings showed that male adults with autism spectrum disorder have regional differences in brain anatomy, which correlate with specific aspects of autistic symptoms. Overall these results suggest that autism spectrum disorder is a condition linked to aberrant developmental trajectories of the frontal networks that persist in adult life.

TWISTED CONJUGACY CLASSES IN R. THOMPSON`S GROUP F

In this article, we prove that any automorphism of R. Thompson`s group F has infinitely many twisted conjugacy classes. The result follows from the work of Brin, together with standard facts about R. Thompson`s group F, and elementary properties of the Reidemeister numbers.

Skapandet av skräcken : John Ajvide Lindqvists Låt den rätte komma in

Syftet med denna uppsats är att undersöka hur och med vilka medel det skrämmande i John Ajvide Lindqvists Låt den rätte komma in skapas, hur detta f��rmedlas till läsaren och vilka konsekvenser detta f��r samt att undersöka på vilket sätt vampyren Eli skiljer sig från den traditionella vampyren.Utgångspunkt i romanen är den mänskliga kroppen och särskilt fokus läggs vid kroppsvätskor, kroppslukter, det sexuellt avvikande och den deformerade kroppen. Gestaltningen av detta handlar om ett brytande mot tabun och etablerade normer som finns i vårt samhälle i dag. Detta skapar känslor av obehag och äckel hos läsaren. Ajvide Lindqvist använder sig av det groteska i syfte att illustrera de obekvämligheter som vi inte vill kännas vid.Eli skiljer sig från den traditionella vampyren genom att vara ett barn och genom att kunna uppfattas som flicka. Här finns också en komplexitet vad gäller kön, då Eli kan sägas vara intergender – av ett odefinierbart kön som ligger bortom de vanliga kategorierna "man" och "kvinna".