Population structure and canopy use by Coussapoa microcarpa, a strangler hemiepiphyte from the Brazilian Atlantic Forest

We studied density, size structure, and establishment sites of Coussapoa microcarpa in the Brazilian Atlantic rain forest. This species is a hemiepiphyte that begins its life in the tops of trees and survives the death of its host to become a free-standing tree. All individuals of C. microcarpa already rooted in the ground were recorded in a 3.43 ha (1.75 ha in lowland and 1.68 ha in submontane) sample of forest plots. Data on total height, root diameter at breast height, host height and diameter at breast height, as well as height, type and diameter of the establishment site were collected. Coussapoa microcarpa present a high density (36.5 ind. ha-1) and the population studied was composed mainly of young individuals. Young and adults differed in establishment sites. The diameter of establishment sites of young was narrower than the diameter of establishment sites of adults, which points out to a limiting factor (diameter of establishment site) regulating the establishment of C. microcarpa. © 2013 Cambridge University Press.

Initial description of the phylogeography, population structure and genetic diversity of Atlantic spotted dolphins from Brazil and the Caribbean, inferred from analyses of mitochondrial and nuclear DNA

We provide initial information regarding the population structure and genetic diversity of Stenella frontalis from the Caribbean and southeastern Brazil from analyses of mitochondrial control region sequences and sequences from the first intron of the α-lactalbumin gene. Comparisons with previously described S. frontalis sequences showed a high number of haplotypes shared between populations throughout their distribution range. High diversity was found for southeastern Brazil and Caribbean samples, and population structure analyses indicate significant differentiation among population units at the FST level, but not at the ΦST level. Significant differentiation at the FST level was found between the Caribbean population unit and all other populations units. These results suggest historical or present connectivity between the Azores and Madeira and the southeastern Brazil groups and population differentiation between the Caribbean and southeastern Brazil, supporting the notion of two separate stocks in the waters around the Atlantic coast of South America. © 2013 Elsevier Ltd.

The population genetic structure of Rhizoctonia solani AG-3PT from potato in the Colombian Andes

The soilborne fungus Rhizoctonia solani anastomosis group 3 (AG-3PT) is a globally important potato pathogen. However, little is known about the population genetic processes affecting field populations of R. solani AG-3PT, especially in the South American Colombian Andes, which is near the center of diversity of the two most common groups of cultivated potato, Solanum tuberosum and S. phureja. We analyzed the genetic structure of 15 populations of R. solani AG-3PT infecting potato in Colombia using 11 simple-sequence repeat (SSR) markers. In total, 288 different multilocus genotypes were identified among 349 fungal isolates. Clonal fractions within field populations were 7 to 33%. R ST statistics indicated a very low level of population differentiation overall, consistent with high contemporary gene flow, though moderate differentiation was found for the most distant southern populations. Genotype flow was also detected, with the most common genotype found widely distributed among field populations. All populations showed evidence of a mixed reproductive mode, including both asexual and sexual reproduction, but two populations displayed evidence of inbreeding. © 2013 The American Phytopathological Society.

Structure-function relationships of the peptide Paulistine: A novel toxin from the venom of the social wasp Polybia paulista

Background: The peptide Paulistine was isolated from the venom of wasp Polybia paulista. This peptide exists under a natural equilibrium between the forms: oxidised - with an intra-molecular disulphide bridge; and reduced - in which the thiol groups of the cysteine residues do not form the disulphide bridge. The biological activities of both forms of the peptide are unknown up to now. Methods: Both forms of Paulistine were synthesised and the thiol groups of the reduced form were protected with the acetamidemethyl group [Acm-Paulistine] to prevent re-oxidation. The structure/activity relationships of the two forms were investigated, taking into account the importance of the disulphide bridge. Results: Paulistine has a more compact structure, while Acm-Paulistine has a more expanded conformation. Bioassays reported that Paulistine caused hyperalgesia by interacting with the receptors of lipid mediators involved in the cyclooxygenase type II pathway, while Acm-Paullistine also caused hyperalgesia, but mediated by receptors involved in the participation of prostanoids in the cyclooxygenase type II pathway. Conclusion: The acetamidemethylation of the thiol groups of cysteine residues caused small structural changes, which in turn may have affected some physicochemical properties of the Paulistine. Thus, the dissociation of the hyperalgesy from the edematogenic effect when the actions of Paulistine and Acm-Paulistine are compared to each other may be resulting from the influence of the introduction of Acm-group in the structure of Paulistine. General significance: The peptides Paulistine and Acm-Paulistine may be used as interesting tools to investigate the mechanisms of pain and inflammation in future studies. © 2013 Elsevier B.V.

Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma Klotzsch

Estudos fitoquímicos com as cascas do caule e com as folhas de Croton palanostigma Klotzsch (Euphorbiaceae) levaram ao isolamento do novo diterpeno clerodânico 8-epicordatina (2), além de éster metílico do ácido 12-oxohardwickiico (3), aparisthmano, cordatina (1), ácido ent-trachiloban-18-óico, óxido de ent-13-epimanoila, óxido de ent-3-oxo-13-epimanoila, óxido de ent-3β-hidroxi-13-epimanoila, sitosterol, estigmasterol, estigmastan-3-ona, 6β-hidroxiestigmast-4-en-3-ona, 6β-hidroxiestigmasta-4,22-dien-3-ona, estigmast-4-en-3-ona, estigmasta-4,22-dien-3-ona, ácido 3-O-acetilaleuritolico, 11α-hidroxiurs-12-en-3-ona, α-amirenona, 24-metilenocicloartenona e lupenona. Estas substâncias foram isoladas através de procedimentos fitoquímicos usuais e suas estruturas foram deduzidas por estudos espectroscópicos, incluindo experimentos em 2D. Adicionalmente, a estrutura cristalina de 8-epicordatina (2) foi determinada por difração de raios-X. Cálculos teóricos de RMN ao nível B3PW91/DGDZVP foram usados para confirmação dos assinalamentos dos deslocamentos químicos dos hidrogênios H-7α e H-7β de 8-epicordatina.

Biflagellate spermatozoon structure of the hermaphrodite fish Satanoperca jurupari (Heckel, 1840) (Teleostei, Cichlidae) from the Amazon River

Foram estudados aspectos ultra-estruturais do espermatozóide do teleósteo hermafrodita Satanoperca jurupari (HECKEL, 1840) do rio Amazonas. Em diferentes oocistos testiculares encontram-se fases evolutivas de espermatócitos, espermátides e espermatozóides. Nos estádios mais jovens, nos espermatócitos, foram observados os respectivos complexos sinaptonêmicos. O espermatozóide maduro do tipo "introsperm" apresenta cabeça pequena de ~ 3 mm de comprimento e 1,3 mm de largura, sem acrosoma, com uma pequena peça intermediária de ~ 1,2 mm de comprimento e 1,8 mm de largura, contendo algumas mitocôndrias esféricas, circundando os dois centríolos e formando um colar mitocondrial. Esse espermatozóide apresenta 2 flagelos, cada um com ~ 15 mm de comprimento e com a formação microtubular comum de 9 + 2. Cada flagelo tem 2 extensões citoplasmáticas lateralmente opostas, sendo formadas cerca de 3 mm abaixo da peça intermediária, acompanhando o flagelo até a parte final.

Shading effects on community composition and food web structure of a deforested pasture stream: Evidences from a field experiment in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure and post-translational modifications of the web silk protein spidroin-1 from Nephila spiders

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure of the polypeptide crotamine from the Brazilian rattlesnake Crotalus durissus terrificus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of monomeric and polymeric structure on the physical properties of thermoplastic polyesters derived from hydroxy fatty acids

The physical properties of three vegetable oil derived medium and long chain poly(-hydroxy fatty ester)s (P(Me--OHFA)s), namely poly(-hydroxynonanoate) [P(Me--OHC9)], poly(-hydroxytridecanoate) [P(Me--OHC13)] and poly(-hydroxyoctadecanoate) [P(Me--OHC18)] (n = 8, 12 and 17, respectively), of the [-(CH2)(n)-COO-](x) polyester homologous series are presented. The effect of M-n (M-n 10-40 kg mol(-1)) and n on the crystal structure and thermal and mechanical properties of the P(Me--OHFA)s were investigated by wide-angle X-ray diffraction (WAXD), TGA, DSC, dynamic mechanical analysis (DMA) and tensile analysis and are discussed in the context of the [-(CH2)(n)-COO-](x) polyester homologous series, contrasted with linear polyethylene (PE). For all P(Me--OHFA)s the WAXD data indicated an orthorhombic crystal phase reminiscent of linear PE with crystallinity (X-c = 50%-80%) depending strongly on M-n. The glass transition temperature and Young's modulus for P(Me--OHFA)s increased with X-c. The DSC, DMA and TGA studies for P(Me--OHFA)s (n = 8, 12 and 17) indicated strong correlations between the melting, glass transition and thermal degradation behavior and n. The established predictive structure relationships can be used for the custom engineering of polyester materials suitable for specialty and commodity applications. (c) 2014 Society of Chemical Industry

Genetic diversity and population structure of the New World screwworm fly from the Amazon region of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Insights on the structure of native CNF, an endogenous phospholipase A(2) inhibitor from Crotalus durissus terrificus, the South American rattlesnake

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A structure-based proposal for a comprehensive myotoxic mechanism of phospholipase A(2)-like proteins from viperid snake venoms

Envenomation via snakebites is an important public health problem in many tropical and subtropical countries that, in addition to mortality, can result in permanent sequelae as a consequence of local tissue damage, which represents a major challenge to antivenom therapy. Venom phospholipases A(2) (PLA(2)s) and PLA(2)-like proteins play a leading role in the complex pathogenesis of skeletal muscle necrosis, nevertheless their precise mechanism of action is only partially understood. Recently, detailed structural information has been obtained for more than twenty different members of the PLA(2)-like myotoxin subfamily. In this review, we integrate the available structural, biochemical and functional data on these toxins and present a comprehensive hypothesis for their myotoxic mechanism. This process involves an allosteric transition and the participation of two independent interaction sites for docking and disruption of the target membrane, respectively, leading to a five-step mechanism of action. Furthermore, recent functional and structural studies of these toxins complexed with ligands reveal diverse neutralization mechanisms that can be classified into at least three different groups. Therefore, the data summarized here for the PLA(2)-like myotoxins could provide a useful molecular basis for the search for novel neutralizing strategies to improve the treatment of envenomation by viperid snakes. (C) 2014 Elsevier B.V. All rights reserved.

Observation of a peaking structure in the J/psi phi mass spectrum from B-+/- -> J/psi phi K-+/- decays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)