Distributional patterns of diatom communities in Mediterranean rivers

Aquesta tesi tracta la jerarquia i l'heterogene��tat dels sistemes fluvials que afecten l'estructura de les comunitats bent��niques de diatomees. A nivell regional, es van buscar diferents grups de punts i les seves esp��cies indicadores, es va estudiar la resposta de les comunitats de diatomees als gradients ambientals, es va avaluar la utilitat de diferents ��ndexs de diatomees i es va buscar el millor sistema de classificaci�� per a condicions de refer��ncia. A nivell de conca, es volien definir els factors que determinen la distribuci�� longitudinal de la diversitat de les comunitats de diatomees. Finalment, a nivell d'h��bitat es van determinar quins factors afecten les algues i els cianobacteris a aquesta escala i es va examinar la contribuci�� relativa de l'ambient i l'espai en la distribuci�� de la biomassa i composici�� d'algues i cianobacteris. Per tant, els diferents cap��tols d'aquesta tesi han estat desenvolupats seguint aquest esquema.

Social perception gaze patterns, symptom severity and resting brain function measured using Arterial Spin Labelling

Autistic spectrum disorder (ASD) is characterised by qualitative alterations in reciprocal social interactions. Some recent studies show alterations in gaze patterns during social perception and rest-functional abnormalities in the ���social brain network���. This study investigated: i) social perception gaze patterns in children with ASD and controls, ii) the relationship between autism clinical severity and social perception gaze patterns, iii) the relationship between resting cerebral blood flow (rCBF) and social perception gaze patterns. Methods: Nine children with ASD and 9 children with typical development were studied. Eye-tracking was used to detect gaze patterns during presentation of stimuli depicting social scenes. Autism clinical severity was established using the Autism Diagnostic Interview Revised (ADI-R). Arterial spin labelling MRI was used to quantify rCBF. Results: The ASD group looked less at social regions and more at non-social regions than controls. No significant correlation was found between ASD clinical severity and social perception gaze patterns. In the ASD group, gaze behaviour was related to rCBF in the temporal lobe regions at trend level. Positive correlations were found between temporal rCBF and gaze to the face region, while negative correlations were found between temporal rCBF and gaze to non-social regions. Conclusions: These preliminary results suggest that social perception gaze patterns are altered in children with ASD, and could be related to temporal rCBF.