1,602 research outputs found
Solvability of some third-order boundary value problems with asymmetric unbounded nonlinearities
In this paper, we present existence and location results for the third-order separated boundary value problems …info:eu-repo/semantics/publishedVersio
Utilização agrícola e compostagem de lamas de origem têxtil
Utilização agrícola e compostagem de lamas de origem têxtil
ZnGa2O4:Mn2+ phosphors grown by Laser Floating Zone
Cubic zinc gallate (c-ZnGa2O4) has attracted the attention of the scientific community due to its potential phosphor applications, namely in field emission displays (FEDs) and other electroluminescent devices. Among other advantages, this oxide matrix shows superior thermal and chemical stability when compared to ZnS based phosphors. Most of the above mentioned works comprise nanostructures, thin films or pressed pellets while scarce information is found on bulk c-ZnGa2O4 material. In particular, no records were found regarding c-ZnGa2O4 crystal growth by the laser floating zone (LFZ) technique. In this work, crystalline fibres of manganese doped (0.01 mol %) zinc gallate were produced via LFZ in order to investigate its applicability in efficient phosphors. The transition metal ions are suitable activators and show some advantages over the widely used rare earths, namely at environmental and economic levels
Composição química e atividade antimicrobiana do óleo essencial de folhas e flores de Aloysia gratissima
Volatile oils from leaves and flowers of Aloysia gratissima were investigated for their chemical composition and antimicrobial activity against the bacteria Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae and the Candida albicans yeast. The minimum inhibitory concentrations (MIC) of the oils were determined by the micro-dilution method, while the chemical composition was determined by GC-MS (gas chromatography mass spectrometry). The fresh leaves and inflorescence were subjected to hydrodistillation for 120 min using a Clevenger-type apparatus, and the essential oil was tested against microorganisms. High concentrations of sesquiterpenes were observed for the inflorescence, and monoterpenes were observed for the leaves. The main compounds of the inflorescence essential oil were E-caryophyllene, germacrene B, guaiol and bulnesol, while in the leaves the main compounds were trans-pinocamphone, trans-pinocarveyl acetate, and guaiol. The essential oil from the leaves showed an effect against P. aeruginosa and S. pneumonia, and the essential oil of the inflorescence showed an effect against P. aeruginosa, S. pneumonia, and Candida albicans.O óleo essencial de folhas e de flores de Aloysia gratissima foi avaliado quanto à composição química e ação antimicrobiana contra as bactérias Bacilus subtilis, Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa, Streptococcus pneumoniae, e a levedura Candida albicans. A concentração mínima inibitória (MIC) dos óleos essenciais foi determinada pelo método da microdiluição e a composição química determinada por CG-EM (Cromatografia Gasosa acoplada a Espectrômetro de Massas). Folhas e inflorescências frescas foram hidrodestiladas por 120 minutos em aparelho Clevenger sendo o óleo essencial testado contra microorganismos. Para as flores foi observada maior concentração de sesquiterpenos, enquanto que as folhas apresentaram maior concentração de monoterpenos. Os principais constituintes do óleo essencial da flor foram: E-cariofileno, germacreno B, guaiol e bulnesol; e das folhas foram: trans-pinocamfona, acetato de trans-pinocarveol e guaiol. O óleo essencial da folha mostrou atividade contra P. aeruginosa e S. pneumoniae, e o óleo essencial da flor mostrou atividade contra P. aeruginosa, S. pneumoniae e Candida albicans.583588Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
LOWER CRETACEOUS DINOSAUR TRACKS FROM THE SEASHORE AREAS OF
Trata-se da descoberta de uma pista na praia de Parede, uma famosa área turística localizada a cerca de 20 km a partir de Lisboa, perto de Cascais, onde um dos poucos
tracksites dinossauro conhecido do Cretáceo Inferior de Portugal podem ser observados. Uma visão geral da pista quase horizontal
nível situado em frente ao "Bar Terraço Xana" põe em evidência uma sequência principal de pegadas interpretado como um saurópode
trackway. Tem uma grande importância pedagógica - turística pela grande facilidade de acesso e observação
Co-existence Of Ants And Termites In Cecropia Pachystachya Trécul (urticaceae)
Individuals of Cecropia pachystachya Trécul (Urticaceae) host Azteca (Hymenoptera: Formicidae) colonies in their hollow internodes and feed them with glycogen bodies produced in modified petiole bases (trichilia). In turn, ants keep trees free from herbivores and lianas. Here, we report for the first time the association of nests of Nasutitermes ephratae Rambur (Isoptera: Termitidae) with these trees, in South-Pantanal (Brazil). We aimed to describe the Cecropia-ant-termite relationship and to investigate how their coexistence is made possible. We hypothesize that: 1) The frequency of termite nests in C. pachystachya is lower than in neighbor trees; 2) Termite nests occur in trees with lower density of foraging ants; 3) The time that ants take to find and remove live termite baits in C. pachystachya trees is lower in leaves (close to trichilia) than in trunks; 4) Termite nests are fixed preferentially in the smallest and less branched trees; and 5) Termite nests are fixed preferentially distant from the canopies. Unexpectedly, termitaria occurred in C. pachystachya at the same frequency as in other tree species; there was no relationship between ant patrol activity and the occurrence of termite nests in C. pachystachya; and they occurred mainly in the tallest and more branched trees. However, termite nests generally were fixed in the trunk, fork or basal branches, where there is better physical support and ant patrol is more modest. The segregation of termite and ant life-areas may represent a escape strategy of termites in relation to ants inhabiting C. pachystachya, specially during nest establishment. 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Federal de Goiás, Instituto de Ciências Bio-lógicas/DBG, GoiâniaDavidson, D.W., Fisher, B.L., Symbiosis of ants with Cecropia as a function of light regime (1991) Ant-Plant Interactions, pp. 289-309. , Huxley, C. & Cutler, D. K. (eds.), New York: Oxford University PressDavidson, D.W., McKey, D., The evolutionary ecology of symbiotic ant-plant relationships (1993) Journal of Hymenoptera Research, 2, pp. 13-83Dejean, A., Fénéron, R., Predatory behaviour in the ponerine ant, Centromyrmex bequaerti: A case of termitolesty (1999) Behavioural Processes, 47, pp. 125-133Dejean, A., Grangier, J., Leroy, C., Orivel, J., Preda-tion and aggressiveness in host plant protection: A generalization using ants of the genus Azteca (2009) Naturwissenschaften, 96, pp. 57-63Delabie, J.H.C., Inquilinismo simultâneo de duas es-pécies de Centromyrmex (Hymenoptera: Formicinae: Pone-rinae) em cupinzeiros de Syntermes sp. 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Probing the Conformational States of Thimet Oligopeptidase in Solution
Thimet oligopeptidase (TOP) is a metallopeptidase involved in the metabolism of oligopeptides inside and outside cells of various tissues. It has been proposed that substrate or inhibitor binding in the TOP active site induces a large hinge‐bending movement leading to a closed structure, in which the bound ligand is enclosed. The main goal of the present work was to study this conformational change, and fluorescence techniques were used. Four active TOP mutants were created, each equipped with a single‐Trp residue (fluorescence donor) and a p‐nitro‐phenylalanine (pNF) residue as fluorescence acceptor at opposite sides of the active site. pNF was biosynthetically incorporated with high efficiency using the amber codon suppression technology. Inhibitor binding induced shorter Donor‐Acceptor (D‐A) distances in all mutants, supporting the view that a hinge-like movement is operative in TOP. The activity of TOP is known to be dependent on the ionic strength of the assay buffer and D‐A distances were measured at different ionic strengths. Interestingly, a correlation between the D‐A distance and the catalytic activity of TOP was observed: the highest activities corresponded to the shortest D‐A distances. In this study for the first time the hinge‐bending motion of a metallopeptidase in solution could be studied, yielding insight about the position of the equilibrium between the open and closed conformation. This information will contribute to a more detailed understanding of the mode of action of these enzymes, including therapeutic targets like neurolysin and angiotensin‐converting enzyme 2 (ACE2)
Accidental and late parasitological diagnosis of Leishmania sp. in a dog from a low disease transmission area of Brazil: a case report
Canine Leishmaniasis diagnosis must be fast and accurate since dogs are urban reservoirs of the disease and earlier therapeutic intervention is more clinically effective. However, this still represents a challenge, particularly in low transmission areas. The present report describes the difficulties of clinical suspicion and the late diagnosis of a dog infected with Leishmania sp
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