Genetic variability on worldwide populations of the scale insect Pulvinariella mesembryanthemi

The South African scale insect Pulvinariella mesembryanthemi was introduced worldwide in several coastal areas with Mediterranean climate, probably through infested plants of Carpobrotus sp. Its high host specificity and its capacity to produce severe damages in the invasive Carpobrotus sp. plants makes this insect a potential biocontrol agent. To test the efficiency and host range of insects used for biocontrol, population genetic studies can help to unravel cryptic complexes and intraspecific diversity. In this study we performed a genetic analysis including native and exotic populations of P. mesembryanthemi, through Sanger sequencing of mitochondrial (cytochrome c oxidase I, COI) and ribosomal (D2–D3 expansion segments of the large subunit ribosomal RNA gene 28S) gene fragments. Accidentally, an endosymbiont was sequenced with one of the pair of primers used. The exotic populations of the insect did not show any variability among populations for both studied genes, which suggest a common origin of all studied introduced populations. Contrastingly, native populations showed high variability and seemed to be a cryptic species complex. Moreover, the Gauteng populations (from NE South Africa) were phylogenetically the closest to the exotic ones, suggesting that the exotic populations could be original from somewhere near this area. An endosymbiont of P. mesembryanthemi was detected, and the sequenced coxA gene was similar to that of the Rickettsiaceae family from the α-Proteobacteria, and close to other insect endosymbionts. To the best of our knowledge, this was the first mention of this endosymbiont in P. mesembryanthemi, although α-Proteobacteria endosymbionts have been reported for other sap-sucking insects.info:eu-repo/semantics/publishedVersio

Predicting progression of cognitive decline to dementia using dyadic patterns of subjective reporting: evidence from the CompAS longitudinal study

ObjectiveTo analyze the validity of self and informant reports, depressive symptomatology, and some sociodemographic variables to predict the risk of cognitive decline at different follow-up times.MethodsA total of 337 participants over 50 years of age included in the CompAS and classified as Cognitively Unimpaired (CU), Subjective Cognitive Decline (SCD) and Mild Cognitive Impairment (MCI) groups were assessed at baseline and three follow-ups. A short version of the QAM was administered to assess the severity of subjective cognitive complaints (SCCs), and the GDS-15 was used to evaluate the depressive symptoms. At each follow-up assessment, participants were reclassified according to the stability, regression or progression of their conditions. Logistic regression analysis was used to predict which CU, SCD and MCI participants would remain stable, regress or progress at a 3rd follow-up by using self- and informant-reported complaints, depressive symptomatology, age and education at baseline and 2nd follow-ups as the predictive variables.ResultsOverall, self-reported complaints predicted progression between the asymptomatic and presymptomatic stages. As the objective deterioration increased, i.e., when SCD progressed to MCI or dementia, the SCCs reported by informants proved the best predictors of progression. Depressive symptomatology was also a predictor of progression from CU to SCD and from SCD to MCI.ConclusionA late increase in self-reported complaints make valid estimates to predict subjective decline at asymptomatic stages. However, an early increase in complaints reported by informants was more accurate in predicting objective decline from asymptomatic stages. Both, early and late decrease in self-reported complaints successfully predict dementia from prodromic stage. Only late decrease in self-reported complaints predict reversion from prodromic and pre-symptomatic stages

Effects on soil and alternatives for biological control of the invasive plant Carpobrotus edulis

The invasive plant Carpobrotus edulis can alter soil properties through its necromass (chemically different from natives’). Depending on the accumulated necromass, C. edulis has contrasting effects on soil pH, leading to different effects on nutrient availability. Carpobrotus edulis alters the soil nitrogen cycle through changes in nitrogen fluxes that can limit nitrogen availability. Until now, potential agents for biocontrol of C. edulis had not been studied. The fungus Sclerotinia sclerotiorum can infect C. edulis, but with no long‐term consequences in greenhouse conditions. The insect Pulvinariella mesembryanthemi can reduce survival and growth of the plant. This insect was introduced accidentally in NW Spain, where its potential distribution roughly overlaps that of C. edulis, but its abundance may be restricted by weather conditions in winter, parasitism and predation. Worldwide introductions of P. mesembryanthemi seem to originate from one native population, and most of its genetic variability resides in its native area

VI Encontro da Mocidade Investigadora: Libro de resumos

Libro de resumos correspondentes ás presentacións durante o VI Encontro da Mocidade Investigadora - CienciasUniversidade de Santiago de Compostela. Centro Internacional de Estudos de Doutoramento e Estudos Avanzado

Make EU trade with Brazil sustainable

Brazil, home to one of the planet's last great forests, is currently in trade negotiations with its second largest trading partner, the European Union (EU). We urge the EU to seize this critical opportunity to ensure that Brazil protects human rights and the environment