Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni) in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of Sao Carlos, Sao Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

Background: Preclinical and clinical evidence suggest that low-dose cannabinoids could ameliorate Alzheimer's disease (AD) signs and symptoms. We designed this trial to evaluate the safety and efficacy of low-dose THC-CBD balanced cannabinoid extract in the treatment of patients with AD-associated dementia. Objective: The objective of this phase 2 trial was to evaluate the safety and efficacy of a balanced THC-CBD cannabinoid extract for symptomatic patients with AD. Methods: A Phase 2, randomized, double-blind, placebo-controlled, clinical trial including patients between 60 and 80 years-old diagnosed with AD-associated dementia. For 26 weeks, participants orally received either placebo or THC-CBD extract (0.350 mg/THC and 0.245 mg/CBD), daily. Results: At week 26, Mini-Mental State Exam total score was significantly higher in cannabis- when compared to placebo-treated patients, which was assessed using the mixed model analysis. No significant difference was detected between placebo and cannabis groups in terms of secondary outcomes and adverse events incidence. Conclusions: To this date, this is the longest clinical trial evaluating cannabinoids effects on AD patients. We initially demonstrate that low-dose THC-CBD potentially can be an effective and safe therapeutic option for AD-related dementia. Nonetheless, larger and longer trials are necessary to confirm this finding and establish cannabinoid administration as therapy for AD dementia. Trial Registration: The Brazilian Registry of Clinical Trials (ReBEC) registration #U1111-1258-2058 - REBEC (ensaiosclinicos.gov.br).

Background: Promoting changes in abiotic conditions and ecosystem processes, such as decomposition, is a mechanism by which some exotic plant species displace native plants and become invasive. Aims: We monitored ramets of Hedychium coronarium over 30 months to estimate the litter decay rate, biomass dynamics and litter accumulation over time in riparian sites invaded by the species in southeastern Brazil. Methods: We measured the number, height, emergence and mortality of ramets in three environments invaded by H. coronarium (natural, rural and urban). We also measured litter decay in situ and in in vitro experiments. We used sinusoidal models to describe height fluctuation and exponential models to simulate litter decay and litter accumulation. Results: Ramets of H. coronarium showed high seasonal variation in terms of height and emergence, as well as low litter decay. Accordingly, our models predicted high litter production and a seasonal pattern of litter accumulation in invaded sites. Conclusions: H. coronarium produces a great amount of litter, which shows slow decay and hence seems to affect decomposition processes. Investigating seasonal variation on the effects of invasive species on ecosystem functioning shed light on the factors driving the success and impact of invasive plants.

Este trabalho apresenta uma análise da climatologia de frentes frias e do regime de ventos induzido por esses fenômenos sobre a Região Metropolitana de São Paulo (RMSP), no período de 21 anos (1987 a 2007). Foram utilizados dados de vento da estação meteorológica do IAG/USP, localizada no bairro da Água Funda - São Paulo - SP. Os resultados mostram que três frentes, em média, chegam a RMSP mensalmente, sendo que sua freqüência é maior nos meses de março a maio, e de agosto a dezembro. Com relação ao vento, esse mostrou-se mais intenso nos dias anteriores a passagem da frente fria, mínimo na chegada, aumentando gradativamente nos dias seguintes (quando sua direção é predominantemente de sudeste (90% da velocidade média, e 70% das rajadas). As correlações feitas entre frentes frias e a dinâmica nos reservatórios mostraram que, em média, o tempo de resposta de um evento para outro foi de 2 a 3 dias na represa Guarapiranga, e 3 a 4 dias na represa Billings. Os parâmetros físico-químicos medidos nas represas foram temperatura (C), pH e Turbidez (NTU). This study presents an analysis of climatology of cold fronts and wind regimes induced by these phenomena over the Metropolitan Region of São Paulo (MRSP) within a time period of 21 years from 1987 to 2007. The wind data series were acquired from the IAG/USP meteorological station, located at Água Funda neighborhood of São Paulo City. The results showed that three fronts, on average, reached the MRSP monthly, and their frequency is higher from March to May and from August to December. Winds showed to be more intense few days before the cold front passage. During the cold front arriving day, wind velocity was at lowest value, increasing gradually in the following days, when the direction was predominantly from southeast quadrant (90 % around the mean velocity and 70 % of the gusts). The correlations between the cold fronts and the dynamics of the reservoirs showed that, in average, the time lag between these events was 2 to 3 days for Guarapiranga Reservoir and 3 to 4 days for Billings Reservoir. The physical-chemical parameters measured in the reservoirs were temperature (C), pH and Turbidity (NTU)