The ethnoecology of Caiçara metapopulations (Atlantic Forest, Brazil): ecological concepts and questions

The Atlantic Forest is represented on the coast of Brazil by approximately 7,5% of remnants, much of these concentrated on the country's SE coast. Within these southeastern remnants, we still find the coastal Caiçaras who descend from Native Indians and Portuguese Colonizers. The maintenance of such populations, and their existence in spite of the deforestation that occurred on the Atlantic Forest coast, deserves especial attention and analysis. In this study, I address, in particular, the Caiçaras who live on the coast of São Paulo and Rio de Janeiro States, illustrating with examples of coastal inhabitants from other areas, such as Bahia State (NE coast) and of other forested areas (riverine caboclos of the Amazon). The major focus of this study, based on previous research, performed since 1986 in several populations or villages of the Atlantic Forest coast, is to understand the resilience of the Caiçaras, which is analyzed using ecological concepts, such as metapopulation, resilience and adaptive cycles. The Caiçara populations are located on islands (Búzios, Comprida, Grande, Ilhabela, Jaguanum, Gipóia) and on the coast (Bertioga, Puruba, Picinguaba, among others). Information gathered about the Caiçaras regarding the economic cycles of the local regions, along with ecological, historical and economic data available, are used to understand such resilience, and are complemented with comparative examples from the Brazilian Amazon and with variables such as the local restrictions imposed by environmental governmental agencies

Neuroprotection by adenosine in the brain: From A1 receptor activation to A2A receptor blockade

Adenosine is a neuromodulator that operates via the most abundant inhibitory adenosine A1 receptors (A1Rs) and the less abundant, but widespread, facilitatory A2ARs. It is commonly assumed that A1Rs play a key role in neuroprotection since they decrease glutamate release and hyperpolarize neurons. In fact, A1R activation at the onset of neuronal injury attenuates brain damage, whereas its blockade exacerbates damage in adult animals. However, there is a down-regulation of central A1Rs in chronic noxious situations. In contrast, A2ARs are up-regulated in noxious brain conditions and their blockade confers robust brain neuroprotection in adult animals. The brain neuroprotective effect of A2AR antagonists is maintained in chronic noxious brain conditions without observable peripheral effects, thus justifying the interest of A2AR antagonists as novel protective agents in neurodegenerative diseases such as Parkinson’s and Alzheimer’s disease, ischemic brain damage and epilepsy. The greater interest of A2AR blockade compared to A1R activation does not mean that A1R activation is irrelevant for a neuroprotective strategy. In fact, it is proposed that coupling A2AR antagonists with strategies aimed at bursting the levels of extracellular adenosine (by inhibiting adenosine kinase) to activate A1Rs might constitute the more robust brain neuroprotective strategy based on the adenosine neuromodulatory system. This strategy should be useful in adult animals and especially in the elderly (where brain pathologies are prevalent) but is not valid for fetus or newborns where the impact of adenosine receptors on brain damage is different

Assessment of variation in bacterial composition among microhabitats in a mangrove environment using DGGE fingerprints and barcoded pyrosequencing

Here, we use DGGE fingerprinting and barcoded pyrosequencing data, at six cut-off levels (85-100%), of all bacteria, Alphaproteobacteria and Betaproteobacteria to assess composition in the rhizosphere of nursery plants and nursery-raised transplants, native plants and bulk sediment in a mangrove habitat. When comparing compositional data based on DGGE fingerprinting and barcoded pyrosequencing at different cut-off levels, all revealed highly significant differences in composition among microhabitats. Procrustes superimposition revealed that ordination results using cut-off levels from 85-100% and DGGE fingerprint data were highly congruent with the standard 97% cut-off level. The various approaches revealed a primary gradient in composition from nursery to mangrove samples. The affinity between the nursery and transplants was greatest when using Betaproteobacteria followed by Alphaproteobacteria data. There was a distinct secondary gradient in composition from transplants to bulk sediment with native plants intermediate, which was most prevalent using all bacteria at intermediate cut-off levels (92-97%). Our results show that PCR-DGGE provides a robust and cost effective exploratory approach and is effective in distinguishing among a priori defined groups.This study was funded by the Deutsche Forschungsgemeinschaft SM59/4-1 and 4-2 (www.dfg.de/en/index.jsp), FAPERJ-Brazil (www.faperj.br), Centre for Environmental and Marine Studies (CESAM, Portugal) (www.cesam.ua.pt), Foundation for Science and Technology (FCT, Portugal) PTDC/AAC-CLI/107916/2008 (http://alfa.fct.mctes.pt) and the European Regional Development Fund (ERDF) through COMPETE- (FCOMP-01-0124-FEDER-008657). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.publishe