Limited evidence of autocorrelation signaling upcoming affective episodes: a 12-month e-diary study in patients with bipolar disorder.

BACKGROUND: Increased autocorrelation (AR) of system-specific measures has been suggested as a predictor for critical transitions in complex systems. Increased AR of mood scores has been reported to anticipate depressive episodes in major depressive disorder, while other studies found AR increases to be associated with depressive episodes themselves. Data on AR in patients with bipolar disorders (BD) is limited and inconclusive. METHODS: Patients with BD reported their current mood via daily e-diaries for 12 months. Current affective status (euthymic, prodromal, depressed, (hypo)manic) was assessed in 26 bi-weekly expert interviews. Exploratory analyses tested whether self-reported current mood and AR of the same item could differentiate between prodromal phases or affective episodes and euthymia. RESULTS: A total of 29 depressive and 20 (hypo)manic episodes were observed in 29 participants with BD. Self-reported current mood was significantly decreased during the two weeks prior to a depressive episode (early prodromal, late prodromal), but not changed prior to manic episodes. The AR was neither a significant predictor for the early or late prodromal phase of depression nor for the early prodromal phase of (hypo)mania. Decreased AR was found in the late prodromal phase of (hypo)mania. Increased AR was mainly found during depressive episodes. CONCLUSIONS: AR changes might not be better at predicting depressive episodes than simple self-report measures on current mood in patients with BD. Increased AR was mostly found during depressive episodes. Potentially, changes in AR might anticipate (hypo)manic episodes.

Two thrush species as dispersers of Miconia prasina (Sw.) DC. (Melastomataceae): an experimental approach / Duas espécies de Turdus como dispersoras de Miconia prasina (Melastomataceae): uma abordagem experimental

We carried out a seed germination experiment using two thrush species in captivity. We compared the number of germinated seeds and germination time of control seeds (manually removed from fruits) and ingested seeds of Miconia prasina by two bird species, Turdus albicollis and T. amaurochalinus, and also compared retention times of seeds by both thrush species. Control seeds germinated more frequently than those ingested for one species, T. albicollis. The germination time of ingested seeds by T. amaurochalinus was similar to the control seeds but seeds ingested by T. albicollis took longer to germinate than the controls. Both thrush species had a similar seed defecation pattern. The cumulative number of defecated seeds increased by 2 hours after fruit ingestion. At the end of the first 30 minutes both species had already defecated approximately 50 percent of the seeds ingested Our results suggest that both species could act as disperser agents of M. prasina.

Realizamos um experimento de germinação utilizando duas espécies de Turdus em cativeiro. Comparamos o número de sementes germinadas e o tempo de germinação entre sementes controle (manualmente removidas dos frutos) e ingeridas de Miconia prasina por duas espécies de aves, Turdus albicollis e T. amaurochalinus, e também comparamos o tempo de retenção das sementes pelas duas espécies de Turdus. Sementes controle germinaram com maior freqüência do que as ingeridas por uma das espécies, T. albicollis. O tempo de germinação das sementes ingeridas por T. amaurochalinus foi semelhante ao das sementes controle, mas as sementes ingeridas por T. albicollis demoraram mais para germinar do que as sementes controle. Ambas as espécies de Turdus tiveram um padrão similar de defecação das sementes. O número acumulado de sementes defecadas aumentou por 2 horas após a ingestão dos frutos. Ao final dos primeiros 30 minutos ambas espécies já haviam defecado aproximadamente 50 por cento das sementes ingeridas Nossos resultados sugerem que as duas espécies de aves podem atuar como agentes dispersores de sementes de M. prasina.