Asphaltene aggregation mechanism is still a nebulous and controversial issue. Many authors argue that the aggregation of its components is due to π-stacking interactions, nonetheless, alkyl chains, heteroatoms, and even acidic groups are also constituents of asphaltenes and can play an important role in the chemistry of asphaltene. Excimers from pyrene are easily detected by fluorescence and were used in the current study to probe the effect of the side chain on the π-stacking capacity of pyrene. Pyrene was acylated with acyl chains varying from two to twelve carbon atoms, and the effect of the variation of the acyl chain length on excimer formation was followed by fluorescence emission spectroscopy. The results revealed that as the side chain grows from two to twelve carbon atoms the excimer/monomer ratio decreases and the excimer heat of formation drops from ΔH = -6.00 to -1.29 kcal mol-1. Further, the crystal structure of octanoyl pyrene (PC8) indicates that in the crystal structure, the aromatic moiety faces the acyl chain. This result was corroborated by density functional theory (DFT) calculations. Finally, the results were compared with two different asphaltenes and indicate that π-stacking cannot be assumed as the main driving force for asphaltene aggregation. issue πstacking π stacking interactions nonetheless heteroatoms spectroscopy excimermonomer monomer 6.00 600 6 00 -6.0 1.29 129 1 29 -1.2 mol1. mol1 mol 1. mol-1 Further PC8 PC (PC8 DFT (DFT calculations Finally 6.0 60 0 -6. 1.2 12 2 -1. mol- (PC 6. -6 -1 -

Abstract Fifteen polar extracts from leaf, seed, pod, stem, flower and root of Crotalaria spectabilis were prepared using aqueous systems, based on the principles of green chemistry, and showed different protease inhibitor (PI) activities on trypsin, papain, pepsin and the extracellular L. amazonensis serine protease (LSPIII). The most pronounced inhibitory effect on LSPIII was observed in leaf (CS-P), root, stem, flower (CS-FPVPP) and pod (CS-VA) extracts. Crotalaria extracts exhibited low cytotoxicity on macrophages; however, they decreased the viability of L. amazonensis promastigotes and amastigotes, as observed in leaf (CS-AE, CS-P, CS-T and CS-PVPP), seed (CS-ST), flower and root (CS-RA) extracts. CS-P was chosen to study PI and secondary metabolites and a 10-12 kDa protein, analyzed by mass spectrometry, was identified as a serine PI homologous with papaya latex serine PI. Glycosylated flavonoids, such as quercetins, vitexin and tricin were the major secondary metabolites of CS-P. The presence of PIs in C. spectabilis is a new finding, especially in other organs than seeds since PIs have been reported only in seed legumes. Besides, this is the first report of antileishmanial activity of C. spectabilis extracts and the identification of serine polypeptide PI and glycosylated flavonoids from leaf. stem systems chemistry (PI trypsin papain L LSPIII. . (LSPIII) CSP, CSP CS P , (CS-P) CSFPVPP FPVPP (CS-FPVPP CSVA VA (CS-VA macrophages however amastigotes CSAE, CSAE AE, AE (CS-AE P, CST T CSPVPP, CSPVPP PVPP CS-PVPP) CSST, CSST ST (CS-ST) CSRA RA (CS-RA 1012 10 12 10-1 protein spectrometry quercetins CSP. P. C finding legumes Besides (LSPIII (CS-P CS-PVPP (CS-ST 101 1 10-

Abstract Different fluids can permeate the soil collapsing at various levels of severity depending on their physicochemical characteristics. This work evaluated the effect of pH and electrical conductivity (ECf) of different soaking fluids on the collapsible behavior of a lateritic silty clay. Double and single oedometer tests were performed using four chemically distinct soaking fluids (water, leachate and two laboratory solutions, one alkaline and one acid). The collapse index (I) was evaluated according to two criteria. In addition, physical-chemical analysis of the soil and measurements of pH and ECf were done. According to the results, the soil is collapsible for the four soaking fluids. No single relationship was found between fluid pH and collapse index, although, the highest values of collapse index were found in the tests soaked with alkaline and acid solutions. Finally, a unique direct relationship was found between the collapse index and the ECf, that is, the higher this parameter, the higher the collapse index value.

A alimentação de peixes e os padrões ecomorfológicos estão relacionados com vários fatores como ontogenia. O presente trabalho foi realizado a fim de testar a hipótese de que a dieta e os padrões ecomorfológicos apresentam correlações positivas entre os diferentes estágios de ontogenia de Plagioscion squamosissimus (Heckel, 1840), pois à medida que a espécie passa da fase jovem para adulta altera a sua alimentação e morfologia. A pescada foi escolhida por ser a espécie mais abundante no reservatório da Estação Ecológica de Tapacurá, Estado de Pernambuco. Os padrões ecomorfológicos foram avaliados e relacionados com a alimentação dos indivíduos capturados no reservatório no mês de abril de 2013. As medidas morfométricas foram retiradas de todos os indivíduos capturados e posteriormente recolhidos seus estômagos. Os peixes foram separados de acordo com a fase de desenvolvimento, juvenis e adultos. Também foram tomados seu peso total, comprimento padrão e aferidas onze medidas lineares, utilizadas para obter os índices que representam os atributos ecomorfológicos. Os itens alimentares foram identificados e separados até menor nível taxonômico possível, sendo o mais frequente o camarão Macrobrachium amazonicum (Heller, 1862). Foi possível observar que nos juvenis os itens ingeridos apresentavam maior amplitude no tamanho em comparação com os adultos. Dos dados morfométricos observa-se que os valores de largura da cabeça são maiores nos juvenis e os valores da altura do corpo são mais elevados nos adultos, sendo estes fatores importantes para determinar o tamanho da presa ingerida pelo peixe. Conclui-se que a espécie Plagioscion squamosissimus mostrou relação positiva entre a morfologia e alimentação ao longo do desenvolvimento ontogenético evidenciado pela variação de comprimento dos itens ingeridos entre juvenis e adultos, porém não houve distinção em relação ao alimento ingerido entre eles.

The fish feeding and the ecomorphological patterns are related to several factors such as ontogeny. The present report was realized to test the hypothesis that the diet and the ecomorphological patterns present positive correlations between the different ontogeny stages of Plagioscion squamosissimus (Heckel, 1840) because as the species pass the young to adult phase to alter their diet and morphology. The croaker was chosen because is the more abundant specie in reservoir of Tapacurá Ecologic Station, state of Pernambuco. The ecomorphological patterns were valued and related with the feeding of individuals captured in a reservoir in April 2013. The morphometric measures were taken of all captured individuals and after were collected their stomachs. Fish were separated according to development stage, in juveniles and adults. Also total weight and their standard length were measured and eleven linear measurements were taken, used to obtain the indices that represent ecomorphological attributes. The food items were identified and separated until the smaller taxonomic level, been the most abundant the shrimp Macrobrachium amazonicum (Heller, 1862). It was observed that in the juveniles the items ingest presented wide amplitude size than adults. Through morphometric data it was observed that the head width values are bigger in juveniles and the body weight values are bigger in adults, being this important factors to determine the prey size ingested by the fish. It is concluded that the specie Plagioscion squamosissimus showed the relationship positive between morphology and feeding along the ontogenetic development evidenced by the variation in length of the ingest items between juveniles and adults, but there was no distinction in relation to ingest food between them.

Latex is an endogenous milky fluid synthesized and accumulated under pressure in a network of laticifer cells. In this study, latices from five plant species were examined for deterrent effect on oviposition of two Coleoptera (Bruchidae) pests. The latex from Euphorbia tirucalli, Calotropis procera and Plumeria rubrae exhibited deterrent activity on oviposition of both Callosobruchus maculatusand Zabrotis subfasciatus beetles. The latex from Cryptostegia grandiflora and Himathantus drasticus were less effective to C. maculatus and Z. subfasciatus oviposition, respectively. Eggs laid on latex-treated seeds were not affected.The emergence and the mean time of development and weight of larvae grown in treated seeds were similar to the controls. The deterrent activity of C. procera and P. rubra was dose and time-dependent for Z. subfasciatus rather than to C. maculatus. The deterrent effect was completely eliminated if the whole latices were fractionated in protein fractions, rubber and small metabolites. Exposing insects to crude latices did not alter ovipostion on untreated seeds. These RESULTSsuggest that latices possess deterrent activity on insect oviposition mediated by a repellent effect, but that proteins and volatile substances are probably not involved. The repellent-like activity can be considered as a defensive role played by these fluids that relies on the combined action of their components.