Showing papers by "Universidade Federal de Minas Gerais published in 1990"
TL;DR: The predator avoidance behaviour of a free-ranging group of buffy-headed marmosets was recorded in detail during the course of a long-term study of behavioural ecology at the Fazenda Montes Claros, southeastern Brazil.
Abstract: The predator avoidance behaviour of a free-ranging group of buffy-headed marmosets,Callithrix flaviceps, was recorded in detail during the course of a long-term study of behavioural ecology at the Fazenda Montes Claros, southeastern Brazil. Four distinct patterns of predator avoidance behaviour, each with specific vocalisations, were recognised and are described here. The selection and use of sleeping sites by the study group are also described. An analysis of the records indicates that these small monkeys are generally most vulnerable to predation by aerial raptors. Variations in the frequency of alarm calls also indicate that the marmosets tend to be more vigilant at higher levels in the forest and when the leaf cover is less extensive. The implications of group size and social structure for both the evolution and the efficacy of the anti-predator behaviour of marmosets are also discussed.
92 citations
TL;DR: Light and electron microscopic and microbiologic evaluations were performed on mucosa of stomachs from 120 healthy slaughtered pigs, and a tightly spiralled bacterium, not previously described, was seen in histological sections and/or in carbol fuchsin stained smears in 13 bacteria-positive pigs.
88 citations
01 Oct 1990
TL;DR: In this article, cost-performance analysis of heterogeneity in supercomputer architectures is performed using queuing models. And the results show that heterogeneity is a quite promising design approach that deserves further investigation.
Abstract: Heterogeneity has appeared as a cost-effective approach to design high performance computers. This paper analyzes cost-performance of heterogeneity in supercomputer architectures. Queueing models are used to study performance of homogeneous and heterogeneous supercomputer models. Grosch's Law, which states that computer performance increases as the square of its cost, is used to analyze cost aspects of the models. The results of this paper show that heterogeneity in supercomputer architectures is a quite promising design approach that deserves further investigation.
63 citations
TL;DR: This bacterium was morphologically similar to the spiral micro-organism distinct from H. pylori which has been described recently in human antral mucosa from patients with gastritis and may be of potential significance as a pathogen in man.
Abstract: The ultrastructural features of a helical-shaped bacterium occurring in the stomach of pigs, within the mucus on the mucosal surface of antral pits, were examined. The bacterial cell had three to eight spiral turns, flattened and truncated ends and was approximately 4.0 microns long and 0.6 microns wide. In some sections, up to six flagella, about 22 nm in diameter, were seen arising from each pole. The cytoplasm contained sparse, irregular granules, numerous ribosomes and large single-layered membrane-bound granules. In the flagella insertion area, there was a highly electron-dense component, the "polar membrane". This micro-organism differed from similar bacteria described in cats, dogs and monkeys, and may cause inflammation in the antral mucosa of pigs similar to Helicobacter pylori infection in man. Furthermore, it was morphologically similar to the spiral micro-organism distinct from H. pylori which has been described recently in human antral mucosa from patients with gastritis and may be of potential significance as a pathogen in man. The name "Gastrospirillum suis" is proposed for this bacterium.
61 citations
TL;DR: A revisao, buscamos os antecedentes historicos da avaliacao dos servicos de saude e apresentamos as propostas contemporâneas de sistematizacao da avadiacao de qualidade as discussed by the authors.
Abstract: No momento em que se discute a reorganizacao dos servicos de saude no Brasil, a avaliacao da qualidade destes servicos ganha importância. Nesta revisao, buscamos os antecedentes historicos da avaliacao dos servicos de saude e apresentamos as propostas contemporâneas de sistematizacao da avaliacao de qualidade. Atraves da analise dos trabalhos revisados, identificamos duas grandes linhas metodologicas de acordo com seu objeto de estudo: Estudos Corporativos Racionalizadores e Estudos Antropossociais. A maioria destes se referenciam nos trabalhos desenvolvidos por Avedis Donabedian, autor que, nos ultimos vinte anos, vem desenvolvendo estudos de avaliacao dos servicos de saude.
57 citations
TL;DR: This finding demonstrated the predominance of immunoglobulin M antibody in sera of vaccinated subjects and that a component of Leish vaccine 5, gp63, was immunogenic in humans both at the T-cell level and at the antibody level.
Abstract: Brazilian army conscripts were vaccinated against American cutaneous leishmaniasis by using nonliving polyvalent promastigote Leish vaccine 5 or Leish vaccine 6 (vaccines with five or six Leishmania stocks) with or without Corynebacterium parvum. No statistically significant differences in lymphocyte stimulation indices were found between vaccinated groups with or without C. parvum, but lymphocyte stimulation indices of all vaccinees were significantly higher (P less than 0.001) than those of the placebo group. A correlation of 90% was found between positive skin test results and positive lymphocyte stimulation indices. Eight major antigens with estimated molecular masses of 13.5, 25, 40, 63, 73, 85, 97, and 160 kilodaltons were recognized by Leish vaccine 5 sera. Our finding also demonstrated the predominance of immunoglobulin M antibody in sera of vaccinated subjects and that a component of Leish vaccine 5, gp63, was immunogenic in humans both at the T-cell level and at the antibody level.
57 citations
TL;DR: The results showed that prolonged maintenance of T.cruzi in mice by successive passages alters the isoenzyme and k-DNA patterns of some strains and that these alterations tend to move towards zymodeme A, suggesting a selective effect of mice over these T. cruzi populations.
53 citations
TL;DR: A highly polar compound isolated from the stem of Petiveria alliacea was shown to be trans-N-methyl-4- methoxyproline on the basis of its microanalysis and spectral data as mentioned in this paper.
48 citations
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TL;DR: In this paper, the authors describe all smooth vector fields on the torus T2 with a finite number of singularities, no periodic orbits and no saddleconnections, and give a large class of analytic vector fields which have non-trivial recurrence and also sinks.
Abstract: The purpose of this research is to describe all smooth vector fields on the torus T2 with a finite number of singularities, no periodic orbits and no saddleconnections. In this paper we are able to complete the description within the class of vector fields which are area contracting near all singularities. In particular we give a large class of analytic vector fields on the torus T2 which have non-trivial recurrence and also sinks.
41 citations
TL;DR: Dados reforcam a ideia que a mastofauna da Mata Atlântica e bastante diversa deve ser considerado como uma das principais areas para a conservacao de fauna desta regiao e sua protecao deveSer priorizada.
Abstract: Durante um periodo de 29 meses consecutivos foram realizados inventarios de mamiferos em habitais de floresta nativa e exotica, alem de area de campo, todos situados no Parque Florestal Estadual do Rio Doce, localizado na regiao ocidental da Mata Atlântica no estado de Minas Gerais Foram registradas para o Parque um total de 60 especies de mamiferos, distribuidas por 9 ordens, 24 familias e 49 generos De um esforco total de 64300 armadilhas-noite, foram realizados 2129 capturas de pequenos mamiferos nao-voadores pertencentes a 20 especies Foram tambem capturadas 14 especies de quiropteros, representando 12 generos e 4 familias Em 300 Km de censos diurnos repetidos nas areas de mata nativa foram registradas 12 especies de mamiferos de medio e grande porte, alem de 14 outras observadas atraves de meios diversos Estes dados reforcam a ideia que a mastofauna da Mata Atlântica e bastante diversa O Parque Estadual Florestal do Rio Doce deve ser considerado como uma das principais areas para a conservacao de fauna desta regiao e sua protecao deve ser priorizada
TL;DR: Very low serum levels of high density lipoprotein cholesterol ranging from 8.6 to 13.9 mg/dl were detected in four out of 12 sibs of a Brazilian kindred with the non-neuropathic form of Niemann-Pick disease.
Abstract: Very low serum levels of high density lipoprotein cholesterol ranging from 8.6 to 13.9 mg/dl were detected in four out of 12 sibs of a Brazilian kindred with the non-neuropathic form of Niemann-Pick disease. Hepatosplenomegaly, interstitial infiltration of the lungs, absence of neurological signs, sea-blue histiocytes in the bone marrow and liver, and high values for serum acid phosphatase (18 to 32 U/l) were common to all affected children. Leucocyte acid sphingomyelinase activity ranged from 3.6 to 6.5% of mean control values, and fibroblast activity from 9 to 13% of mean controls. The parents had low-normal levels. The relationship between these findings is unclear and deserves further investigation.
TL;DR: Eight cases of chronic pancreatitis, anatomicopathologically studied, have not showed the typical pancreatic changes of either chronic calcifying pancreatitis or of obstructive pancreatitis and were impossible to classify according to the 1984 Marseilles' classification.
Abstract: Summary We observed 797 consecutive cases of chronic pancreatitis from 1963 to 1987 in the cities of Belo Horizonte and Sao Paulo. Alcoholism was the main etiological agent, responsible for 714 cases (89.6%). Chronic calcifying pancreatitis from different etiologies, alcohol, idiopathic, nutritional, and familial, was the most important form of chronic pancreatitis, with 786 cases (98.6%). Only three cases of chronic obstructive pancreatitis were diagnosed. Eight cases of chronic pancreatitis, anatomicopathologically studied, have not showed the typical pancreatic changes of either chronic calcifying pancreatitis or of obstructive pancreatitis and were impossible to classify according to the 1984 Marseilles' classification.
TL;DR: Wildlife surveys were conducted in two stands of Eucalyptus, one homogeneous and the other with a native species understorey in the Atlantic forest region of southeastern Brazil, finding that wildlife communities were depauperate in the homogeneous stand, but richer in eucalyPT forest with native speciesUnderstorey.
Abstract: Wildlife surveys were conducted in two stands of Eucalyptus, one homogeneous and the other with a native species understorey in the Atlantic forest region of southeastern Brazil Deforestation has reduced the original forested habitat to a patchwork of cultivated fields and mono-specific forestry plantations Wildlife communities were depauperate in the homogeneous stand, but richer in eucalypt forest with native species understorey Small mammals, particularly didelphid marsupials, used the understorey rather than the eucalypt emergent trees Primates were absent from both areas The increasing demand for charcoal for the growing steel industry in the region means that eucalypt plantations will persist until an alternative energy source is found It is essential that management efforts be directed towards multi-use strategies in these plantations Eucalypt plantations with a native species understorey might provide sufficient habitat to support some wildlife species of the rapidly disappearing Atlantic coastal forest ecosystem
TL;DR: The Supergrupo Espinhaco Meridional, a unidade e constituida por oito formacoes that can be divided into dois groups distintos, is a group of sedimentacoes in which the most frequent formations are diamantfferos, filhos, and metavulcânicas as mentioned in this paper.
Abstract: As sequencias de quartzitosque estruturam a Serfa do Espinhaco no centro-norte de Minas Gerais e na Bahia integram o Supergrupo Espinhaco. Na regiao de) Espinhaco Meridional, a unidade e constituida por oito formacoes que podem ser reunidas em dois grupos distintos, com base na historia evolutiva e contexto deposicional da bacia de sedimentacao. O Grupo Diamantina, correspondente as tres formacoes basais, ocorre na porcao central e leste da Cordilheira, registrando um dominio deposicional com predominância continental, num periodo de grande instabilidade crustal. Os litotipos mais frequentes sao quartzitos finos e grossos, conglomerados muitas vezes diamantfferos (Formacao Sopa-Brumadinho), filhos e rochas metavulcânicas sin-sedimentares relativas a um magmatismo bimodal. O Grupo Conselheiro Mata, constituido pelas formacoes do topo, e caracteristicamente marinho, assinalando condicoes gerais de tendencias transgressivas em toda a bacia, numa fase de estabilidade tectonica. Litologicamente, a unidade e uma sucessao de quartzitos e filitos em alternância, sem registros de vulcanismo sin-sedimentar. A deposicao do Supergrupo ocorreu durante o Proterozoico Medio, numa bacia do tipo rifte intracratonico, cujo eixo principal se estendia em direcao submeridiana, ligeiramente a oeste de Diamantina. A deformacao impressa a unidade e relativa ao Ciclo Brasiliano. O mecanismo gerador de tensoes foi uma colisao continental a leste da Cordilheira, responsavel pela orogenia contracional que afetou toda a regiao e originou o transporte de massas para oeste, em direcao ao Craton Sao Francisco, num regime de cisalhamento simples progressivo.
TL;DR: Experimental evidence is presented that schisto somiasis may be a predisposing cause for hepatic abscesses and it is reported here 2 patients with acute schistosomiasis and pyogenic liver abscesss and it are presented experimental evidence that schistso- somiasis is a predispose cause for hepatitis.
Abstract: The most common predisposing cause for pyo genic hepatic abscess is currently biliary tract disease. Infection in areas drained by the venous system (e.g., appendicitis, diverticulosis, Crohn’s disease) may also result in pylephlebitis and pyogenic hepatic abscess. Other causes include penetrating or blunt abdominal trauma, septicemia, and infection arising in necrotic primary or secondary tumor deposits. Pyogenic liver abscesses may be single or multiple. Multiple small abscesses occur particularly in association with pylephlebitis, biliary tract obstruction with cholan gitis, and septicemia. In many cases, no predisposing cause is apparent3 6. It is reported here 2 patients with acute schistosomiasis and pyogenic liver abscesses and we present experimental evidence that schisto somiasis may be a predisposing cause for hepatic abscesses.
TL;DR: A survey for intestinal parasites was carried out in a homogenous rice cultivation area, in which people had equal opportunities of acquiring the local endemic helminthiases, including schistosomiasis mansoni, and egg counts were positively correlated with ancylostome infection but inversely correlated with A. lumbricoides and T. trichiura.
Abstract: A survey for intestinal parasites was carried out in a homogenous rice cultivation area, in which people had equal opportunities of acquiring the local endemic helminthiases, including schistosomiasis mansoni. The numbers of Schistosoma mansoni eggs excreted in faeces were counted. Infections with S. mansoni, Ascaris lumbricoides, ancylostomes and Trichuris trichiura were not randomly distributed, but were correlated, depending on the species of worms present. The S. mansoni egg counts were positively correlated with ancylostome infection but inversely correlated with A. lumbricoides and T. trichiura. Patients with schistosomiasis associated with 2 other helminth infections excreted more S. mansoni eggs than the patients with S. mansoni plus only one other helminth infection.
TL;DR: Etude par une approche du groupe de renormalisation en champ moyen determination du diagramme de phases, application aux alliages Fe−Mn−Al.
Abstract: Etude par une approche du groupe de renormalisation en champ moyen. Determination du diagramme de phases. Application aux alliages Fe−Mn−Al. On effectue des ajustements du diagramme de phase experimental et du champ hyperfin moyen reduit, a temperature ambiante
TL;DR: In this paper, an inner sphere mechanism was proposed for the Fe(III) reduction of 2-formylpyridine thiosemicarbazone (FPT) complexes, where the ligand is the reducing agent.
TL;DR: The bark wood of Austroplenckia populnea has been used to obtain pentacyclic triterpenes, including 3-oxoolean-12-ene-20α-car-car and 3β-hydroxy-2-oxofriedelan-20 α-car -car.
TL;DR: It is concluded that δ‐dendrotoxin interacts with a distinct site on the oligomeric acceptor complex in synaptosomes that prevents the labelling of both these bands.
Abstract: With use of biologically active 125I-labelled delta-dendrotoxin, a putative K+-channel ligand, homogeneous, noninteracting, high-affinity acceptors (KD = 0.32 +/- 0.07 nM; Bmax = 0.33 +/- 0.04 pmol/mg) were observed in synaptosomes from guinea-pig cortex. This binding was antagonised noncompetitively by alpha-dendrotoxin, an inhibitor of certain fast-activating, voltage-gated K+ channels. Chemical cross-linking of the delta-dendrotoxin-acceptor complex in synaptosomes yielded two specifically labeled polypeptides with molecular masses of 69 and 82 kilodaltons. Although alpha-dendrotoxin prevents the labelling of both these bands, it cross-linked only a single protein with a molecular mass of 69 kilodaltons. It is concluded that delta-dendrotoxin interacts with a distinct site on the oligomeric acceptors for alpha-dendrotoxin.
TL;DR: The stems of Vismia martiana have been shown to contain sitosterol, dammaradienol, betulic acid, friedelin, euxanthone, 1,1′,8,8′-tetrahydroxy-3,3′-dimethyl-6,6′ -dimethoxy-7,7′-( trans -3-methyl-1-butenyl)-10, 10′-bianthrone ( meso and ±), chrysophanic acid, madagascin, vismiaquinone B,
TL;DR: To the knowledge this is the first time that Leishmania has been shown into the ocular globe, and it is reported that it led to a needle aspiration of the anterior eye chamber content.
Abstract: The Authors report an uncommon case of leishmaniasis with disseminated cutaneous lesions, systemic manifestations and ocular involvement, the latter being characterized by bilateral nongranulomatous iridocyclitis. The severity of the oph-thalmologic lesions and its unresponsiveness to therapy (in spite of satisfactory regression of both systemic and cutaneous manifestations) lead to a needle aspiration of the anterior eye chamber, content. From this material Leishmania sp was isolated. To our knowledge this is the first time that Leishmania has been shown into the ocular globe.
TL;DR: In mice fed on the iron-deficient diet, the disease was more severe for CL strain and less severe for Y and YuYu strains; these findings may be due to intraspecific differences among the strains.
TL;DR: A significant polyclonal activation of B lymphocytes was observed during experimental infection of C57BL/10J mice with Schistosoma mansoni and high levels ofpolyclonal B cell activation were observed after adoptive transfer of spleen cells from infected mice to isogenic recipients pre-treated with hydroxyurea.
Abstract: A significant polyclonal activation of B lymphocytes was observed during experimental infection of C57BL/10J mice with Schistosoma mansoni. The isotypic pattern of this expansion, assessed by the Protein-A plaque-forming cell method, was compared with and found to differ from those occurring after infection by Trypanosoma cruzi or injection of bacterial LPS. In the infection of S. mansoni an early expansion of most immunoglobulin isotypes occurs together with a late, sustained expansion of IgG1-secreting cells. High levels of polyclonal B cell activation were observed after adoptive transfer of spleen cells from infected mice to isogenic recipients pre-treated with hydroxyurea.
TL;DR: A new multistep algorithm is proposed for the simulated-quenching technique in which the Fock-matrix calculations are reduced to a minimum and the slowing down does not occur, and the resulting program is several times faster than standard self-consistent-field HF programs.
Abstract: A molecular-dynamical formulation of the Hartree-Fock (HF) method is presented. The simulated-annealing and simulated-quenching (steepest-descent) techniques are applied to the minimization of the HF energy functional and to the solution of the HF equations. In a test application to the helium atom with Gaussian basis sets both techniques show good performances but have two drawbacks: an excessive number of Fock-matrix calculations and a slowing-down behaviour close to convergence. We propose a new multistep algorithm for the simulated-quenching technique in which both drawbacks are removed: the Fock-matrix calculations are reduced to a minimum and the slowing down does not occur. The resulting program is several times faster than standard self-consistent-field HF programs.
TL;DR: Patients with chronic Trypanosoma cruzi infections have peripheral auto-anti-idiotype T cells that proliferate on exposure to immunoaffinity-purified antibodies against T. cruzi epimastigote antigens (EPI).
Journal Article•
TL;DR: The time of appearance of pontoneocerebellar hypoplasia is commented upon, based on data concerning the ontogenesis of the structure and on the presence or absence of gliosis in the pontine nuclei and persistence of the fetal pattern in the inferior olivary and dentate nuclei.
Abstract: A case of pontoneocerebellar hypoplasia (PNCH) in a 9-day-old child--the youngest in the literature--is described. Right after birth the child showed serious respiratory insufficiency and developed frequent episodes of apnea and cardiorespiratory arrests, dying on the 9th day. Postmortem examination showed significant alterations only in the brain. There was intense neuron reduction in the pontine, arcuate, inferior olivary and dentate nuclei, reduction of Purkinje cells and of the granular layer of the cerebellum and the disappearance of the pontocerebellar fibers, together with dense fibrillary astrocytosis, which seems to have first appeared in the pontine nuclei. This case is compared with others in the literature and attention is drawn to the more intense, and probably initial, involvement of the pontine nuclei. The time of appearance of pontoneocerebellar hypoplasia is commented upon, based on data concerning the ontogenesis of the structure and on the presence or absence of gliosis in the pontine nuclei and persistence of the fetal pattern in the inferior olivary and dentate nuclei. It is suggested that the process may start in the 2nd or 3rd month of fetal life, or even later, as probably occurred in the present case, during the second or third trimester of intrauterine life.
TL;DR: A study to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania found the sand flies proved to be highly susceptible to infections by a strain of Le.
Abstract: A study was undertaken to compare the susceptibility of laboratory-reared female Lutzomyia longipalpis to infection by different species or strains of New World Leishmania. The sand flies proved to be highly susceptible to infection by a strain of Le. guyanensis, with flagellates developing in all (18/18) of the specimens examined. A lower infection rate of 37 per cents (10/27) was recorded in flies exposed to infection by a strain of Le. amazonensis. Flagellates developed in 13 per cents (6/46) of the sand flies that glood fed on dogs in the earlly stage of experimental infection with an old laboratory strain of Le. chagasi. In contrast, promastigotes did not develop in sand flies that blood fed on dogs with naturally acquired Le. chagasi. The naturally infected dogas were in an advanced stage of disease. Flagellates developed in 9// (3/32) of the sand flies that blood fed on lesions of hamsters infected with a strain of Le. braziliensis and in 9 per cents (3/34) of those that fed on hamsters with lesions due to a parasite fo the mexicana complex (strain MHOM/BR/73/BH121). Sand flies did not develop flagellate infections after blood feeding on hamsters bearing lesions induced by strain MHOM/BR/71/BR49. Factors influencing the susceptibility of Lu. longipalpis to infection by New World species of Leishmania are discussed.