In search of disorders: internalizing symptom networks in a large clinical sample.

Background The co‐occurrence of internalizing disorders is a common form of psychiatric comorbidity, raising questions about the boundaries between these diagnostic categories. We employ network psychometrics in order to: (a) determine whether internalizing symptoms cluster in a manner reflecting DSM diagnostic criteria, (b) gauge how distinct these diagnostic clusters are and (c) examine whether this network structure changes from childhood to early and then late adolescence. Method Symptom‐level data were obtained for service users in publicly funded mental health services in England between 2011 and 2015 (N = 37,162). A symptom network (i.e. Gaussian graphical model) was estimated, and a community detection algorithm was used to explore the clustering of symptoms. Results The estimated network was densely connected and characterized by a multitude of weak associations between symptoms. Six communities of symptoms were identified; however, they were weakly demarcated. Two of these communities corresponded to social phobia and panic disorder, and four did not clearly correspond with DSM diagnostic categories. The network structure was largely consistent by sex and across three age groups (8–11, 12–14 and 15–18 years). Symptom connectivity in the two older age groups was significantly greater compared to the youngest group and there were differences in centrality across the age groups, highlighting the age‐specific relevance of certain symptoms. Conclusions These findings clearly demonstrate the interconnected nature of internalizing symptoms, challenging the view that such pathology takes the form of distinct disorders

Biologie et écologie des poissons d'eau douce africains = Biology and ecology of african freshwater fishes

Ce chapitre porte essentiellement sur les pêcheries dans les systèmes aquatiques non dégradés par les autres activités humaines, telles que la pollution toxique, l'eutrophisation intense, la sédimentation excessive, la canalisation des cours d'eaux. Chacune de ces agressions a cependant bien été caractérisée par des approches comparatives, qualitatives ou quantitatives ... Le contenu de ce chapitre illustre quelques développements prometteurs obtenus à partir de généralisations empiriques concernant divers écosystèmes aquatiques dans différentes parties du monde. D'importants développements ultérieurs sont encore possibles et peuvent être adaptés aux pêcheries africaine

Likely responses to climate change of fish associations in the Laurentian Great Lakes Basin: concepts, methods and findings

How a water body’s temperature characteristics constrain organisms ecologically has been a continuing focus of interest in limnology and aquatic ecology for over a century now. A number of complementary scientific approaches are reviewed briefly. Progress in assessment of climate change is hampered by the still fragmentary and scattered scientific literature. A number of tentative generalizations are sketched. We expect that climate change of a type consistent with currently available scenarios will have severe consequences for Great Lakes fish and fisheries: in rivers that flow south, east or west and which contain isolated endemic species at the northerly edge of their ranges and which have no opportunity to migrate northwards; and where effects on the aquatic ecosystem of climate change interact synergistically and harmfully, as seems likely, with bad effects of other cultural stresses such as damming and nutrient loading.peerReviewe