Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The percentages of dispersal modes per plot are included as Supporting Information (Table S7, based on 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests in Amazonia). The dispersal modes assigned to these 5433 species and morphospecies are also included as Supporting Information (Table S8).Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.Colombian institution Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIASFaculty of Sciences, Universidad de los Ande

Mutagenic and cytotoxic activity of an isocoumarin (Paepalantine) isolated from Paepalanthus vellozioides

A new isocoumarin with antimicrobial activity was isolated from Paepalanthus vellozioides (a native Brazilian plant) and called paepalantine. This study was carried out to assess the mutagenic activity of this new agent in assays with Salmonella typhimurium TA100, TA98, and TA102 and in Chinese hamster ovary (CHO) cell cultures, as well as cytotoxicity to McCoy cells. Paepalantine caused a significant dose-dependent increase in the frequency of revertants in the three strains used in the assay, both with and without S9 mix, in concentrations varying from 2 to 128 mu g/ plate. The mutagenicity was confirmed in assays with CHO cells treated in the G(1), S, and G(2) phases of the cell cycle. There was an increase in the chromosomal aberration frequency, mainly in the G(2) phase. Furthermore, the mitotic index of the treated cultures (40,80, and 160 mu g/ml) was significantly lower, indicating cytotoxicity. The midpoint cytotoxicity values to McCoy cells by the neutral red (NR) and microculture tetrazolium (MTT) techniques resulted in a NR50, and MTT50 of 30 and 38 mu g/ml, respectively. Alterations to the paepalantine structure are suggested to reduce its mutagenic and cytotoxic activity in investigations for its antineoplasic potential (C) 1997 Wiley-Liss, Inc

Perfil dos usuários de crack que buscam atendimento em Centros de Atenção Psicossocial Crack cocaine users who attend outpatient services

O artigo descreve o perfil de 95 usuários de crack acolhidos em três Centros de Atenção Psicossocial (CAPS) da Região Metropolitana de Porto Alegre, no Sul do Brasil, entre agosto de 2009 e março de 2010. Todos os usuários de crack que buscaram atendimento no período foram entrevistados. Utilizou-se questionários desenvolvidos pela equipe, mais o Self-Reporting Questionnaire (SRQ-20) e inventários de critérios de dependência e abuso (SAMHSA). Houve predomínio de pacientes homens, adultos jovens, com escolaridade fundamental, sem ocupação regular, mas com renda individual informada, em uso frequente e pesado há mais de um ano, e a maioria preenchia critérios para dependência e abuso do crack e tinha escores elevados de SRQ-20. Os resultados evidenciam que os CAPS são buscados por usuários de crack em sofrimento, que deve ser valorizado, mas também a existência de algum tipo de seleção na oferta destes serviços, caracterizada pelas especificidades de renda, escolaridade e grupo primário de apoio aos entrevistados.<br>This paper describes the profile of 95 crack cocaine users attending three community mental health services (CAPS) in Greater Metropolitan Porto Alegre, Rio Grande do Sul State, Brazil, from August 2009 to March 2010. The instruments employed were questionnaires developed by the team, the Self-Reporting Questionnaire (SRQ-20), and inventories of criteria for dependence and abuse (SAMHSA). The data depict a group of users consisting predominantly of young males with elementary schooling, without regular employment but reporting individual income, none of whom living on the streets. They were currently addicted, with heavy daily use of crack for more than two years, and with high SRQ-20 score. This group's characteristics showed that the community mental health services are attended by crack users that suffer losses resulting from their addiction, but also some possible selection process in the supply of these health services (based mainly income, schooling, or primary support network)