Tardive dyskinesia and DRD2, DRD3, DRD4, 5-HT2A variants in schizophrenia: an association study with repeated assessment.

We performed an association study between four candidate genes, DRD2, DRD3, DRD4 and 5-HT2A for the presence of tardive dyskinesia (TD) on 84 patients with residual schizophrenia. The sample was evaluated again for the presence of TD after an interval of 3 years. The first group did not exhibit TD in either observation ( n =34) while in the second group of patients exhibited TD in at least one of the observations ( n =20+18). The clinical and socio-demographic characteristics were not significantly different between the two groups; the genetic analysis revealed a significant correlation between the C/C genotype of 5-HT2A and TD ( p =0.017). An association trend was observed between the 'short' variant of DRD4 and TD ( p =0.022). We did not observe any significant association for the DRD2 and DRD3 polymorphisms

Influence of an Interaction between Lithium Salts and a Functional Polymorphism in SLC1A2 on the History of Illness in Bipolar Disorder

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Divergence in Cuticular Chemical Signatures between Isolated Populations of an Intraspecific Social Parasite

Parental care is costly enough that species exist which exploit the parental care of other individuals to rear their own brood, as social parasites do among social insects. Intraspecific, facultative social parasites use the nest and worker force of another colony of the same species to rear their own young as a reproductive strategy alternative to independent nest foundation. Intraspecific parasites face barriers similar to those of interspecific social parasites: they must bypass host nestmate recognition abilities and keep host workers under control. In the present study, we investigate the cuticular chemical signature of Polistes biglumis paper wasps when they behave as intraspecific social parasites and invade conspecific colonies. We performed our analysis on three geographically separated populations, which differ in their social structure; in one population foundresses regularly produce workers, whereas in the others they rarely do. We tested whether the chemical signature of females which parasitize conspecific colonies resembles that of females who found their colonies, and if this effect is similar among populations with high and low numbers of workers. Our results show that in the two populations where foundresses produce virtually no workers, the hydrocarbon signatures of intraspecific social parasites were not chemically distinct from those of the foundresses. In contrast, in the population where foundresses usually produce workers, the hydrocarbon signatures of intraspecific social parasites had a significantly larger proportion of long-chained and branched hydrocarbons than those of foundresses. These characteristics may have evolved in that population to facilitate parasite exploitation of the host workforce, as long-chained and branched hydrocarbons are relevant as recognition and fertility cues. The lack of workers in the other populations may have relaxed the selection pressure that host workers impose on the chemical signature of intraspecific social parasites

FIRMS’INVOLVEMENT IN OPEN SOURCE PROJECTS: A CONTROVERSIAL ROLE

In this paper, we focus on Community OS projects with the goal of understanding whether the involvement of firms through their professional developers has an impact on the quality of the software product and on its overall success. We distinguish between two main typologies of firms’ involvement: Development firms contributions and Non-development firms contributions. The paper posits that a higher percentage of code contributed by paid developers has a positive impact of project success and size. However, it also puts forward a negative impact of non-development firms contribution on software design quality. Hypotheses are tested on a sample of 643 applications from the SourceForge.net repository, corresponding to 5,335 versions. Data were collected by means of an online questionnaire and a tool developed ad hoc to calculate software design quality metrics. Empirical findings support our hypotheses. Overall, our data confirm that firms are significantly investing in OS projects and that they can play a crucial role in determining projects’ success when they also take active part in code development. However, most of them are taking a short-term perspective that does not focus on quality. This may lead to higher costs and a lower user satisfaction in the long term