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Background: Few studies have investigated alterations of olfactory neuroepithelium (ONE) as a biomarker of schizophrenia, and none its association with cognitive functioning. Method: Fresh ONE cells from twelve patients with schizophrenia and thirteen healthy controls were collected by nasal brushing, cultured in proper media and passed twelve times. Markers of cell proliferation (BrdU incorporation, Cyclin-D1 and p21 protein level) were quantified.Cognitive function was measured using Brief Neuropsychological Examination-2. Primary outcome: proliferation of ONE cells from schizophrenic patients at passage 3. Secondary outcome: association between alteration of cell proliferation and cognitive function. Results: Fresh ONE cells from patients showed a faster cell proliferation than those from healthy controls at passage 3. An opposite trend was observed at passage 9, ONE cells of patients with schizophrenia showing slower cell proliferation as compared to healthy controls. In schizophrenia, overall cognitive function (Spearman's rho -0.657, p < 0.01), verbal memory – immediate recall, with interference at 10 s and 30 s (Spearman's rho from -0.676 to 0.697, all p < 0.01) were inversely associated with cell proliferation at passage 3. Conclusion: Fresh ONE cells collected by nasal brushing might eventually represent a tool for diagnosing schizophrenia based upon markers of cell proliferation, which can be easily implemented as single-layer culture. Cell proliferation at passage 3 can be regarded as a promising proxy of cognitive functioning in schizophrenia. Future studies should replicate these findings, and may assess whether ONE alterations are there before onset of psychosis, serving as an early sign in patients with at risk mental state.

Compensatory dynamics, overyielding and statistical averaging are mechanisms promoting the temporal stability of natural communities. Using the model of European intertidal rocky shore assemblages and collating 17 datasets, we investigated how the strength of these stability-enhancing mechanisms varies with latitude and how it can be altered by the loss of habitat-formers (e.g. canopy-forming macroalgae). Community stability decreased with increasing latitude, mostly as a consequence of a greater synchronization of species fluctuations. Statistical averaging and overyielding (i.e. richness effects) promoted stability, but their strength did not vary with latitude. The experimental removal of macroalgal canopies caused a strengthening of the statistical averaging effect that was consistent across the latitudinal gradient investigated. Nonetheless, the loss of canopies depressed stability by enhancing the synchronization of species fluctuations on southernmost shores, while it had weak effects on shores at higher latitudes. Variation in life-history traits among canopy-forming species and/or in prevailing environmental conditions across a gradient of latitude could underlie variable effects of habitat-formers on species fluctuations. Our study shows i) that the stability of intertidal assemblages and strength of compensatory dynamics varies with latitude, ii) that canopy-forming macroalgae, exerting a strong control on understorey species, can influence the strength of compensatory dynamics and iii) that biological forcing (i.e. facilitation) can be as important as environmental forcing in enhancing the synchronization of species fluctuations.

Many studies in marine coastal lagoons have focused on the marine-to-terrestrial gradient as a main source of variation for the structure of assemblages. In this paper, the magnitude of differences among locations arranged along the marine-to-terrestrial gradient of the western lagoon of Orbetello (Grosseto, Italy) was contrasted with the amount of spatial variability occurring among sets of locations that were not positioned along this axis. We propose that if the most important processes influencing assemblages were those associated with the external-internal gradient of the lagoon, as usually supposed, then assemblages should differ more among these locations than among any other locations. To test the above proposition, four locations arranged along the two major axes of the lagoon were established in November 2000. Each location was sampled three times (November 2000, April 2001, August 2001) to test for temporal consistency in spatial patterns. At each time of sampling, three replicate sites were established in each location. This design enabled estimates of spatial variability to be obtained at three scales: among locations hundreds of meters apart, among sites tens of meters apart and among quadrats hundreds of centimeters apart. Non-metric multidimensional scaling (nMDS) ordination plots on abundance data revealed differences among assemblages hundreds of meters apart. Assemblages in the inner part of the lagoon were separated from those closer to the sea inlet, depending on the marine-to-terrestrial gradient. In addition to this pattern, differences also occurred among assemblages hundreds of meters apart, but positioned at a similar distance from the sea. Multifactorial Anovas on abundance of the most common taxa showed significant differences in mean values at the scales of location and site, with patterns changing over time. These results indicated that spatial structure in assemblages was not a distinctive feature of locations arranged along the marine, Beaucoup de recherches sur les lagunes côtières se sont focalisées sur le gradient terre-mer comme principale source de variation de la structure des assemblages. Dans cet article, l'importance des différences d'un lieu à l'autre le long d'un tel gradient dans la partie ouest de la lagune d'Orbetello (Grosseto, Italie) est comparée avec l'importance de la variabilité spatiale de sites qui ne sont pas situés sur cet axe. Si l'influence dominante était bien liée à ce gradient interne-externe, les assemblages devraient différer plus nettement au sein de ces lieux, comparé à tout autre lieu. Pour tester cette proposition, quatre lieux le long des deux axes majeurs de la lagune ont été échantillonnés à trois reprises : novembre 2000, avril 2001 et août 2001. À chaque sortie, trois sites-répliques ont été établis pour chaque lieu. Cette stratégie permet d'estimer la variabilité spatiale à trois échelles : au sein des lieux à des distances de 100 mètres, au sein des sites à des distances de 10 mètres et au sein des quadrats à des distances d'un mètre. Des diagrammes d'abondance classés suivant une échelle multidimensionnelle non métrique révèlent des différences au sein des assemblages distants de centaines de mètres. Les assemblages dans la partie intérieure de la lagune sont séparés de ceux plus près du grau, en accord avec le gradient terre-mer. À côté de ce schéma, des différences apparaissent également parmi les assemblages distants de plusieurs centaines de mètres mais situés à une même distance de la mer. Une analyse multifactorielle utilisant le test Anovas sur l'abondance des taxons les plus fréquents montre des différences significatives des valeurs moyennes aux échelles du lieu et du site, avec des schémas d'organisation variant au cours du temps. Ces résultats montrent que la structure spatiale des assemblages n'est pas un trait caractéristique des lieux bâti autour du terre-mer dans la lagune d'Orbetello. Des différences similaires se rencontrent également par