Showing papers by "Federal University of São Carlos published in 1982"
TL;DR: In this article, an euclidean functional integral approach for the construction of local kink operators and disorder variables is proposed and investigated, where the main difference from the existing quasiclassical approach is the emphasis on local fields instead of kink states and collective coordinate methods.
70 citations
TL;DR: The s-MDH activity of Leiostomus xanthurus and many other species of fish and amphibian appears in three sharp, equally-spaced, anodal bands as discussed by the authors.
Abstract: 1.
1. Following electrophoresis the s-MDH activity of Leiostomus xanthurus and many other species of fish and amphibian appears in three sharp, equally-spaced, anodal bands. Each band is a dimer (AA, AB and BB) and two loci are active.
2.
2. In Leiostomus tissue extracts A and B subunits are present at differing quantitative levels and their activities can be modified by changes in environmental temperature.
3.
3. Thermostability and thermal dependency tests show that, similar to what occurs during acclimatization, the AA isozyme is more stable to heat than is the BB isozyme. The BB isozyme is activated by low temperatures and is rapidly inactivated by high temperatures.
4.
4. Extracts from a variety of fishes, amphibians, reptiles and birds suggest that when only one or two s-MDH bands are present, they behave as does the AA homodimer in Leiostomus xanthurus, i.e., are stable at elevated temperatures.
45 citations
TL;DR: The influence of deoxidation product size distribution in determining the prior austenite grain and the subsequent balance between inter-and intragranular nucleation has been studied in C-Mn-Nb weld metals as discussed by the authors.
Abstract: The influence of the deoxidation product size distribution in determining the prior austenite grain and the subsequent balance between inter- and intragranular nucleation has been studied in C-Mn-Nb weld metals. The growth of austenite appears to be controlled by pinning of the grain boundaries by the deoxidation inclusions, and follows the classical Zener precipitate-boundary interaction equations. Some evidence of the direct nucleation by inclusions of the acicular ferrite phase has been obtained.
45 citations
TL;DR: It was found that skeletal muscle samples of the 30degree C-acclimated spot were more stable to heat than the 20 degrees and 15 degrees C-ACclimated fishes.
Abstract: 1. 1. Isozyme patterns and thermostability of the skeletal muscle and heart malate dehydrogenase (s-MDH) from the spot acclimated to different temperatures were examined. 2. 2. No changes in isozyme patterns were seen for MDH in any of the tissues examined in response to 15° and 20°C acclimation. 3. 3. The A- homodimer , which was more thermostable, showed an increase in its relative activity, whereas the B- homodimer , which was more heat sensitive, showed a decrease during warm acclimation. However, after different periods of low temperature incubation, these samples showed a decrease in their subunit ratios. 4. 4. Concerning the effect to thermal acclimation on the thermostability of MDH, it was found that skeletal muscle samples of the 30°C-acclimated spot were more stable to heat than the 20° and 15°C-acclimated fishes.
30 citations
TL;DR: Neste trabalho esta descrito aspectos do ciclo silvestre do Trypanosoma cruzi em regiao do cerrado do Brasil Central, endemica para doenca de Chagas, quanto a interacoes entre roedores, D. albivetris e triatomineos.
Abstract: Neste trabalho esta descrito aspectos do ciclo silvestre do Trypanosoma cruzi em regiao do cerrado do Brasil Central, endemica para doenca de Chagas. Entre 151 roedores (11 especies) e 73 Didelphis albiventris, capturados em ambiente silvestre, respectivamente 4 (2,6%) e 15 (20,6%), estavam naturalmente infectados pelo T. cruzi. Triatomineos, pertencentes a cinco especies (Rhodnius neglectus, Psammolestes tertius, Triatoma costalimai, Triatoma pseudomaculata e Triatoma sordida) foram tambem capturados em ambiente silvestre e em diferentes tipos de biotopos. Entre 165 exemplares, destes insetos, coletados, dois estavam parasitados pelo T. cruzi (T. costalimai e T. pseudomaculata). Foram ainda realizadas observacoes ecologicas, quanto a interacoes entre roedores, D. albivetris e triatomineos.
30 citations
01 Jan 1982
26 citations
TL;DR: In this article, the changes in texture and substructure induced in commercial purity aluminum by conventional (cross-rolling) and shock wave deformation (peak pressure, 5.8 GPa; pulse duration, 2.8 μs) were studied by X-ray diffraction and transmission electron microscopy.
16 citations
TL;DR: An optimum medium for culturing Melosira italica (subsp. subartica) is described and the optimum concentration of humic acid for growth of this species in culture was found to be 46 µg/ml.
Abstract: An optimum medium for culturing Melosira italica (subsp. subartica) is described. The optimum concentration of humic acid for growth of this species in culture was found to be 46 µg/ml. Tolerance to cupric ions also increased by addition of humic acid. Cultures tended to maintain a pH of about 6.0. Some ecological implications are discussed.
14 citations
TL;DR: The electrochemical oxidation of some p-substituted benzylic derivatives of Co(III) dimethylglyoximato and Co( III)bis(salicylaldehyde)o-phenylenediimine, in dimethylformamide, 0.2 M in tetraethylammonium perchlorate, on a platinum electrode, at several temperatures, is described as an ECE type, the first electrochemical step being a quasi-reversible one-electron charge transfer at room temperature.
14 citations
TL;DR: In this paper, a more convenient procedure to synthesize organic sulfides is described, which is based on the reaction of alkali metal salts of thiols with alkyl halides in polar organic solvents.
10 citations
Journal Article•
TL;DR: A benzene extract of the trunk wood of an Aniba species contained 3a-allyl-2-aryl-5-methoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran as mentioned in this paper.
TL;DR: The electrokinetic and thermostability properties of phosphoglucose isomerase (PGI) in five species of tropical fish--Leporinus friderici, L. silverstrii, Schizodon nasuttus, Hypostomus sp and Pimelodus maculatus--have been studied in order to study the adaptative nature of protein heterogeneity found in ectotherms.
Abstract: 1.
1. The electrokinetic and thermostability properties of phosphoglucose isomerase (PGI) in five species of tropical fish (Ostariophysi)—Leporinus friderici, L. silvestrii, Schizodon nasuttus, Hypostomus sp and Pimelodus maculatus—have been studied in order to study the adaptative nature of protein heterogeneity found in ectotherms.
2.
2. Unlike most diploid fishes, the PGI of these species seemed to be encoded by three, four or rive loci.
3.
3. The subunits encoded by these loci occurred at different levels in the different tissues and organs analyzed.
4.
4. Genetic variants at the three PGI loci were detected in two species of the family Anostomidae (L. friderici and S. nasuttus). In the family Pimelodidae, P. maculatus showed a genetic variant as the Pgi-1 locus.
5.
5. The product of these loci could be separated in three PGI regions based on their electrophoretic mobility, tissue distribution and thermostability properties.
6.
6. The more anodal region (including isozymes and allozymes) was more thermolabile than the less anodal one, which is predominant in a single tissue-skeletal muscle.
TL;DR: In this paper, an Ag/Ag+ this paperERENCE electrode in ethanolic solution was investigated and a method of ethanol purification for electrochemical purposes was also presented, where simple preparation, fast response and high exchange current density characterize this electrode.
Abstract: An investigation of an Ag/Ag+ REFERENCE electrode in ethanolic solution is reported. Simple preparation, fast response and high exchange current density characterize this REFERENCE electrode. A method of ethanol purification for electrochemical purposes is also presented.
Journal Article•
TL;DR: In this paper, the Dirac-bracket formalism for a non-Abelian gauge field coupled to fermions is developed in detail, and the theory is then quantized in the Coulomb gauge by abstracting the equal-time commutators from the corresponding Dirac brackets.
Abstract: We develop in detail the Dirac-bracket formalism for a non-Abelian gauge field coupled to fermions. The theory is then quantized in the Coulomb gauge by abstracting the equal-time commutators from the corresponding Dirac brackets. Our results, obtained by a significantly different method, coincide with those of Schwinger. The role of book-keeper played by the classical theory in the elaboration of the quantum dynamics is clarified.
TL;DR: In this paper, the structural instability wavevector continuously varies along the (2nd order) critical line of the d = 1 first-neighbour spin-1 2 magnetostrictive model in the presence of a magnetic field along the Z-axis.
Journal Article•
TL;DR: In this article, the electrochemical reduction of europium, ytterbium and samarium in propylene carbonate was investigated by cyclic voltammetry, where the first stage is due to the formation of divalent ions.
DOI•
01 Jan 1982TL;DR: In this article, a procedure to use control samples to avoid errors in the technique of dissolved organic matter (DOM) analysis by the liquid cintillation counter is described, and experiments on the validity of stocking preserved filtrates of natural plankton populations and algal cultures were also carried out for long periods prior to the radioactivity measurements.
Abstract: Some aspects of the procedures to measure dissolved organic matter (DOM) released by phytoplankton account for important sources of errors. These aspects include: cell damage upon filtration of samples, residual inorganic 14C in the filtrates, NaH14CO3 ampoule contaminations and the low radiation activity proper to the released samples. Some experiments on these procedural problems were carried out and their effects on the released DOM were evaluated. A procedure to use control samples to avoid errors in the technique of DOM analysis by the liquid cintillation counter is described. Experiments on the validity of stocking preserved filtrates of natural plankton populations and algal cultures were also carried out for long periods prior to the radioactivity measurements.
TL;DR: Foi feita reanalise do conjunto de dados publicados na literatura sobre a associacao entre grupo sanguineo A e esquistossomose mansonica, a qual revelou significante heterogeneidade entre as amostras estudadas.
Abstract: Foi feita reanalise do conjunto de dados publicados na literatura sobre a associacao entre grupo sanguineo A e esquistossomose mansonica, a qual revelou significante heterogeneidade entre as amostras estudadas. Foi sugerido que a associacao deva refletir os efeitos raciais sobre a evolucao clinica da doenca, tendo por base a distribuicao dos grupos sanguineos nos diferentes grupos raciais brasileiros e a maior resistencia do negro ao desenvolvimento das formas graves da molestia.
01 Jan 1982
TL;DR: Neste trabalho esta descrito aspectos do ciclo silvestre do Trypanosoma cruzi em regiao do cerrado do Brasil Central, endemica para doenca de Chagas, quanto a interacoes entre roedores, D. albivetris e triatomineos.
Abstract: Neste trabalho esta descrito aspectos do ciclo silvestre do Trypanosoma cruzi em regiao do cerrado do Brasil Central, endemica para doenca de Chagas. Entre 151 roedores (11 especies) e 73 Didelphis albiventris, capturados em ambiente silvestre, respectivamente 4 (2,6%) e 15 (20,6%), estavam naturalmente infectados pelo T. cruzi. Triatomineos, pertencentes a cinco especies (Rhodnius neglectus, Psammolestes tertius, Triatoma costalimai, Triatoma pseudomaculata e Triatoma sordida) foram tambem capturados em ambiente silvestre e em diferentes tipos de biotopos. Entre 165 exemplares, destes insetos, coletados, dois estavam parasitados pelo T. cruzi (T. costalimai e T. pseudomaculata). Foram ainda realizadas observacoes ecologicas, quanto a interacoes entre roedores, D. albivetris e triatomineos.
TL;DR: In this paper, a literatura produzida by estes se situava noplano normativo, defmindo como o trabalho nos siste-mas de producao.
Abstract: 1. INTRODUCAOAte 1978, epoca em que desenvolvemos esta pesquisa, aliteratura existente sobre processos de trabalho no Brasilremetia a problematica para o plano sociologico e politi-co, pouco enfatizando o aspecto organizacional propria-mente dito. Em realidade, parecia haver uma certa divi-sao de interesses, de forma que o aspecto organizacionalficava por conta de engenheiros e administradores. Noentanto, a literatura produzida por estes se situava noplano normativo, defmindo como o trabalho nos siste-mas de producao
Journal Article•
TL;DR: In this paper, the authors extend the result of Shub for expanding endomorphisms of K preserving the branch set B to the space lm(K) of all immersions of K, and prove that structural stability is not generic.
Abstract: In this paper, in Part 4, we extend this result of Jakobson to the space lm~K) of all C ~ immersions of K preserving the branch set B: in Part 3, we extend the result of Shub for expanding endomorphisms of K preserving B. In Part 2 we give a necessary condition for structural stability of certain endomorphisms of K. We also prove that expanding endomorphisms on a branched l-manifold with non empty branch set are unstable. Using this fact we prove that structural stability is not generic. This paper contains parts of the author's thesis at the Instituto de Matemfitica Pura e Aplicada do C.N.Pq. of Brazil (t980). The author takes the opportunity to thank Professor Jorge Sotomayor, his thesis advisor, for his advice and constant encouragement.
01 Jan 1982
TL;DR: In this article, the excreted dissolved organic matter (DOM) was measured using natural phytoplankton populations from "Enseada do Flamengo" (Lot. 23° 30'S-Long) and enriched artificially with nutrients.
Abstract: Measurements of excreted dissolved organic matter (DOM) were carried out twice (in simmer and winter) using natural phytoplankton populations from "Enseada do Flamengo" (Lot. 23° 30'S-Long. 045°069'W) and enriched artificially with nutrients. The bioassays were carried out inoculating samples of an integral sea water in ten liters flasks, incubated "in situ". Measures were taken in populations growing in: integral " f " media, "f" - N, "f" - P, "f" - (H + P), "f" - (Vit. + Metal traces), and in a control without enrichment. The absolute amount of excreted DOM generally followed the quantity of total carbon assimilated. In the meantime, with the populations with nitrogen deficiency occurred an increase of relatives rates of excretion, not only due to the total carbon assimilation diminution, but effectively also to the absolute increase of the quantity of excreted DOM.