Showing papers by "University of São Paulo published in 1981"
TL;DR: In this article, the Schr\"odinger equation of a free particle rigidly bounded to a surface is discussed, considering the Schr''odinger equations of a particle constrained to move, by the action of an external potential, in an infinitely thin sheet of the ordinary three-dimensional space.
Abstract: The motion of a particle rigidly bounded to a surface is discussed, considering the Schr\"odinger equation of a free particle constrained to move, by the action of an external potential, in an infinitely thin sheet of the ordinary three-dimensional space. Contrary to what seems to be the general belief expressed in the literature, this limiting process gives a perfectly well-defined result, provided that we take some simple precautions in the definition of the potentials and wave functions. It can then be shown that the wave function splits into two parts: the normal part, which contains the infinite energies required by the uncertainty principle, and a tangent part which contains "surface potentials" depending both on the Gaussian and mean curvatures. An immediate consequence of these results is the existence of different quantum mechanical properties for two isometric surfaces, as can be seen from the bound state which appears along the edge of a folded (but not stretched) plane. The fact that this surface potential is not a bending invariant (cannot be expressed as a function of the components of the metric tensor and their derivatives) is also interesting from the more general point of view of the quantum mechanics in curved spaces, since it can never be obtained from the classical Lagrangian of an a priori constrained particle without substantial modifications in the usual quantization procedures. Similar calculations are also presented for the case of a particle bounded to a curve. The properties of the constraining spatial potential, necessary to a meaningful limiting process, are discussed in some detail, and, as expected, the resulting Schr\"odinger equation contains a "linear potential" which is a function of the curvature.
536 citations
Journal Article•
TL;DR: Evidence suggests that MT decrease anxiety by impairing the functioning of brain neuron systems integrating defensive behavior, and the depressant action of MT upon both defense systems may be primarily due to facilitation of neurotransmission mediated by gamma-aminobutyric acid (GABA).
Abstract: In this article the participation of different brain neuron systems in the integration of fear responses, and in the anti-anxiety action of minor tranquilizers (MT) is discussed. As necessary background, the molecular mechanisms of MT action disclosed by recent neurochemical research are briefly described. The reviewed evidence suggests that MT decrease anxiety by impairing the functioning of brain neuron systems integrating defensive behavior. These systems are the septo-hippocampal system, together with its afferent mono-aminergic input from the rostral brain stem, which commands behavioral inhibition arising in situations involving threat of punishment or frustration. In addition, the brain aversive system comprising the dorsal periaqueductal gray matter, the periventricular gray matter and the amygdala integrates the active defense patterns of fight or flight as well as elaborates aversive motivation. The depressant action of MT upon both defense systems may be primarily due to facilitation of neurotransmission mediated by gamma-aminobutyric acid (GABA).
103 citations
TL;DR: The results were considered to be a consequence of the supersensitivity of central dopaminergic receptors probably, of the mesostriatal pathway, that occurred in order to maintain the animal's homeostasis.
Abstract: The effects of single and long-term haloperidol administration on rat open field behavior was studied. Withdrawal from long-term haloperidol treatment induced a significant increase in all parameters of activity recorded, expcept rearing. There was a direct relationship between the impairment of motor function induced by the single haloperidol administration and the increment of general activity observed after withdrawal from repeated drug administration. The results were considered to be a consequence of the supersensitivity of central dopaminergic receptors probably, of the mesostriatal pathway, that occurred in order to maintain the animal's homeostasis.
87 citations
TL;DR: The formation of protein-bound aggregates with defined stoichiometries and a high local vesicles concentration, as well as changes in the local degree of hydration, are proposed to be the driving forces for the protein-induced vesicle fusion in this system.
83 citations
TL;DR: Tais feicoes caracterizam quadro que permite atribuir aquele mosquito maiores oportunidades de contato com a populacao humana e, por conseguinte, papel importante na veiculacao de arboviroses, em especial modo, of encefalites.
Abstract: Relatam-se observacoes sobre o ciclo diario de atividade, por parte de mosquitos Culicidae de mata residual, em area de ambiente intensamente modificado por exploracao agropecuaria, no Vale do Ribeira, Estado de Sao Paulo, Brasil. Foram levadas a efeito, com ritmo bimensal, capturas ininterruptas de vinte e cinco horas com isca humana, alem de coletas simultâneas com ardilhas tipo Shannon em ambiente intra e extra florestal. Os resultados evidenciaram o carater diurno e noturno das especies mais frequentes, com destaque para o Ae. scapularis e Ae. serratus que, embora com atividade classificada como diurna, mantem atuacao apreciavel tambem durante a noite. Em relacao ao primeiro acrescenta-se a ocorrencia de nitido pico endocrepuscular vespertino, e a manutencao de sua presenca no meio extraflorestal. De maneira geral, essas duas especies mostram-se presentes todos os meses do ano, com dominância de Ae. scapularis sobre Ae. serratus somente no mes de junho, ocasiao porem em que aquele sobrepuja a este de maneira consideravel. Tais feicoes caracterizam quadro que permite atribuir aquele mosquito maiores oportunidades de contato com a populacao humana e, por conseguinte, papel importante na veiculacao de arboviroses, em especial modo, de encefalites.
78 citations
TL;DR: Epidemiological variables in relation to hypospadias were analyzed in a case-control study of a liveborn population from six Latin American countries and low mean birth weight, twinning, vaginal bleeding, and drug exposure during the 1st trimester (particularly sex hormones) were found to be risk factors.
Abstract: Epidemiological variables in relation to hypospadias were analyzed in a case-control study of a liveborn population from six Latin American countries. The frequency of hypospadias was 7.6 per 10,000 livebirths (324/423,839). The cases were divided into three types: distal (72%), proximal (18.5%) and non-specified cases (9.5%). The control group consisted of the first nonmalformed child born after each of the patients and was matched by sex, place, and time of birth. Other coexisting malformations were found in 13.6% of cases. The Brazilian sample showed the highest incidence rate (17.7/10,000) and also the highest incidence of severe forms (5.0/10,000) as compared with the other countries.
A circannual rhythm was detected using several different statistical procedures. Low mean birth weight, twinning, vaginal bleeding, and drug exposure during the 1st trimester (particularly sex hormones) were found to be risk factors. The more severe forms had a higher neonatal mortality rate and higher inbreeding when compared with the controls or milder forms. The heritability coefficient was 0.6772 ± 0.0675. The possible role of maternal sex hormone intake and disturbances of human chorionic gonadotropin during the first trimester are discussed.
77 citations
TL;DR: The decrease in amylase, cellulase and trypsin activity in the midgut during starvation is of the same order as that recovered from the excreta, which supports the hypothesis that synthesis that synthesis of these enzymes is controlled.
74 citations
TL;DR: A well-constrained Rb-Sr isochron age of157±8m.y.y and an initial 87 Sr/86 Sr ratio of 0.7087 obtained from a pre-tectonic granitic suite suggest a genetic relation between this suite and Upper Jurassic silicic volcanic rocks in the cover sequence (Tobifera Formation) as discussed by the authors.
74 citations
TL;DR: Breed differences were evident for approach and avoidance behavior, which had little relationship with one another, and age took precedence over breed affiliation in investigating the human.
Abstract: Domestic cattle have paradoxical tendencies both to approach and to avoid humans Approach (investigating a person lying on the ground) and avoidance (flight distance) were studied in 21 herds of 12Bos taurus, B indicus, andB taurus x B indicus breeds located in a homogeneous, Brazilian environment Seven herds were compared in their investigatory responses to a human and a ball Breed differences were evident for approach and avoidance behavior, which had little relationship with one another When reactions to the person and ball were compared, the responses were also breed specific but negatively correlated Age took precedence over breed affiliation in investigating the human The results were interpreted in a predator-prey context
66 citations
64 citations
TL;DR: The phase diagram of MnP was determined from magnetostriction and differential susceptibility measurements as mentioned in this paper, and the results were interpreted in terms of predictions for a Lifshitz point (LP) supplemented by considerations of demagnetization effects.
Abstract: The phase diagram of MnP was determined from magnetostriction and differential susceptibility measurements. Data were taken from 4.2 K up to the Curie temperature ${T}_{C}=290.9$ K. The applied magnetic field ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}}_{0}$ was parallel to the $b$ axis. The focus of the measurements was on the upper triple point ($T=121\ifmmode\pm\else\textpm\fi{}1$ K, ${H}_{0}\ensuremath{\cong}16.5$ kOe) where the paramagnetic (para), ferromagnetic (ferro), and fan phases meet. The transitions on the para-ferro boundary ${H}_{0\ensuremath{\lambda}}(T)$ and on the para-fan boundary ${H}_{0\ensuremath{\lambda}}^{*}(T)$ were of second order. The ferro-fan transitions on the boundary ${H}_{01}(T)$ were of first order. At the upper triple point, all three phase boundaries were tangent to each other, and the $\ensuremath{\lambda}$ line [composed of the boundaries ${H}_{0\ensuremath{\lambda}}(T)$ and ${H}_{0\ensuremath{\lambda}}^{*}(T)$] had an inflection point. These qualitative features agree with those expected at a Lifshitz point (LP). A quantitative analysis of the difference ${H}_{0\ensuremath{\lambda}}^{*}\ensuremath{-}{H}_{01}$ as a function of $T$ gave a crossover exponent $\ensuremath{\varphi}=0.63\ifmmode\pm\else\textpm\fi{}0.04$. This value agrees with the calculated value for the LP. The correspondence between the scaling axes near the upper triple point and those in the theory of the LP is discussed. The phase diagram near the upper triple point was also measured as a function of the angle $\ensuremath{\theta}$ between ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}}_{0}$ and the $b$ axis. The field ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}}_{0}$ was in the $\mathrm{bc}$ plane, and its $c$ component ${H}_{0c}$ played the role of the ordering field for the ferro phase. The results were interpreted in terms of predictions for a LP, supplemented by considerations of demagnetization effects. In addition to the usual parallel differential susceptibility, $\frac{\ensuremath{\partial}M}{\ensuremath{\partial}{H}_{0}}$, the transverse differential susceptibility was also measured near the upper triple point. Here, the applied dc field ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{H}}}_{0}$ was parallel to $b$, the applied modulation field ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{h}}}_{0}$ was parallel to $c$, and the measured quantity was $\frac{\ensuremath{\partial}{M}_{c}}{\ensuremath{\partial}{h}_{0}}$. The transverse susceptibility showed the features expected near a LP. Additional evidence, from two recent neutron studies, that the upper triple point is a LP is summarized. The global phase diagram of MnP, the para-ferro boundary near ${T}_{C}$, and the screw-ferro transition at ${T}_{\ensuremath{\alpha}}=46$ K, are also discussed.
TL;DR: As informacoes obtidas no inquerito triatomineo levado a efeito na regiao nordeste do Brasil permitem concluir que, na transmissao regional epidemiologicamente significante da tripanossomiase americana, desempenha papel relevante o P. megistus em relacao as regioes florestais atlânticas e de inclusao.
Abstract: Sao apresentadas as informacoes obtidas no inquerito triatomineo levado a efeito na regiao nordeste do Brasil. As caracteristicas biogeograficas incluem a presenca de areas semi-aridas da caatinga e amplas faixas transicionais com outras feicoes paisagisticas. Entre estas foram incluidas as da floresta tropical atlântica e as inclusoes florestadas mais extensas. No periodo de 1975 a 1980 foram examinados 15.342 triotomineos coletados no ambiente domiciliar, visando detectar as presencas de sangue ingerido e de infeccao natural por Trypanosoma tipo cruzi. O conteudo intestinal foi submetido a reacoes com antisoros para homem, cao, gato, roedor (Kattus), marsupial (Didelphis) e ave (Gallus). Por ordem de frequencia, as especies encontradas foram Triatoma pseudomaculada (40,6%), Panstrongylus megistus (19,7%), Triatoma brasiliensis e T. sordida (ambos com 14,3%), Rhodnius nasutus (6,1%) e Triatoma infestans (1,1%); alem de em algumas outras raras. A presenca de sangue foi detectada em 42,4% e a infeccao em 3,4% desse total de especimens examinados. Observou-se elevada mobilidade alimentar, com coeficientes gerais de 54,8% para ave e 30,0% para homem. Em nivel especifico pode determinar apreciavel grau de antropofilia em P. megistus e, em menor intensidade, em T. brasiliensis. Por sua vez, T. infestans mostrou-se altamente antropofilo. Observou-se apreciavel ornitofilia em T. pseudomaculata e T. sordida, com elevada intensidade em R. nasutus. Por outro lado, a presenca de sangue humano em especimens capturados no peridomicilio indicou a ocorrencia de frequente mobilidade espacial, com excecao de T. infestans que nao mostrou evidencias de abandonar o domicilio. A tendencia a domiciliacao, alem desta, revelou-se apreciavel em P. megistus, moderada em T. brasiliensi, T. pseudomaculata, T. sordida e praticamente nula em R. nasutus. A distribuicao geografica confirmou o carater autoctone de T. brasiliensis, T. pseudomaculata e R. nasutus em relacao a caatinga, e do P. megistus em relacao as regioes florestais atlânticas e de inclusao. Este ultimo revelou carater invasivo no que concerne a caatinga, enquanto T. infestans e T. sordida mostraram o mesmo aspecto quanto a regiao nordeste como um todo. Os resultados permitem concluir que, na transmissao regional epidemiologicamente significante da tripanossomiase americana, desempenha papel relevante o P. megistus, em primeiro lugar, e o T. brasiliensis, em segundo. Dependendo de fatores varios, provavelmente da densidade, poderao atuar secundariamente nesse sentido o T. pseudomaculata e o T. sordida. Quanto a T. infestans, a sua presenca, em numero reduzido, representa, no momento, risco apenas potencial. O controle rotineiro, mediante a desinsetizacao domiciliar, devera fornecer bons resultados no que concerne a interrupcao da transmissao. Todavia a reinfestacao, pelo menos do peridomicilio, devera provavelmente continuar. E isso em virtude de focos extradomiciliares que fornecem especimens com tendencia a colonizacao no ambiente humano. E de se prever que ela se fara a custa do P. megistus nas areas florestais atlânticas e de inclusao e de T. brasiliensis, T. pseudomaculata e R. nasutus nas areas da caatinga. A vigilância epidemiologica devera pois levar em conta esses aspectos e tender a aumentar sua eficiencia pela continuidade das pesquisas.
TL;DR: Estudo morfologico do exocorio de ovos de dez especies de Rhodnius (Hemiptera-Reduviidae) atraves de microscopia eletronica de varredura e microscopia optica, com vistas a classificacao taxionomica.
Abstract: Foi realizado estudo morfologico do exocorio de ovos de dez especies de Rhodnius (Hemiptera-Reduviidae) atraves de microscopia eletronica de varredura e microscopia optica, com vistas a classificacao taxionomica: Rhodnius domesticus Neiva & Pinto, 1923; R. ecuadoriensis Lent & Leon, 1958; R. nasutus Stal, 1859; R. neglectus Lent, 1954; R. neivai Lent, 1953; R. pallescens Barber, 1932; R. paraensis Sherlock, Guitton & Miles, 1977; R. pictipes Stal, 1972; R. prolixus Stal, 1859; e R. robustus, 1927. Sao apresentados dados sobre aspectos gerais das cascas e dos ovos quanto a forma, coloracao e tamanho, bem como as modificacoes que poderao ocorrer quanto a coloracao durante o desenvolvimento embrionario pos-oviposicao. Sao elaboradas chaves dicotomicas para a classificacao destas especies, baseadas na utilizacao de caracteres visiveis pela microscopia optica e microscopia eletronica de varredura.
TL;DR: The results lend support to the proposal that the endo-ectoperitrophic circulation of digestive enzymes is a consequence of fluid fluxes caused by the transport of water into the first two thirds of midgut lumen, and its transference back to the haemolymph in the gastric caeca and in the distal posterior ventriculus.
TL;DR: In this paper, the authors give some rules to define measures which describe heat flow in homogeneous crystals and then study a particular model which is explicitly solvable: the one dimensional nearest neighborhood Ising model.
Abstract: We give some rules to define measures which could describe heat flow in homogeneous crystals. We then study a particular model which is explicitly solvable: the one dimensional nearest neighborhood Ising model. We analyze two cases. In the first one the spins at the two boundaries interact with reservoirs at different temperatures; in the thermodynamical limit the measure we introduce converges locally to Gibbs measures and a temperature profile is so derived. We obtain an explicit expression for the thermal conductivity coefficient which depends on the temperature. In the second case we study the asymptotic behavior starting from an initial state in which each half of the space is at a different temperature. We find again a temperature profile which asymptotically obeys the heat equation with the thermal conductivity coefficient previously derived. From a mathematical point of view, the analysis of the invariant measure is made possible by studying a “time-reversed” process related to a graphical representation of an associated process. This provides us with an explicit formula for then-fold correlation function and we study the limiting behavior using both this representation (for proving an exchangeability result) and a Donsker-type, spacetime renormalization procedure.
TL;DR: In this paper, a Goldstone-type theorem for a wide class of lattice and continuum quantum systems, both for the ground state and at nonzero temperature, was proved.
Abstract: We prove a Goldstone-type theorem for a wide class of lattice and continuum quantum systems, both for the ground state and at nonzero temperature. For the ground state (T=0) spontaneous breakdown of a continuous symmetry implies no energy gap. For nonzero temperature, spontaneous symmetry breakdown implies slow clustering (noL1 clustering). The methods apply also to nonzero-temperature classical systems.
TL;DR: The trunk wood of Clinostemon mahuba contains eight (3R)-2-alkylidene-3-hydroxy-4-methylenebutanolides, seven (3S,4S)-2.5-methylbutanolide side chains with respect to their E- or Z-geometry, ethenyl, ethynyl, or ethyl terminals and lengths (C16 or C18).
TL;DR: Adult and larval population fluctuation of the South American fruit fly Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) has been determined and related to host availability.
Abstract: Adult and larval population fluctuation of the South American fruit fly Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) has been determined and related to host availability. A peak in the adult population on each host occurred five weeks after the peak in larval population. The average number of larvae per fruit is between 1–5 in large hosts (guava, peach and loquat) and it is smaller than one for small fruit (surinam cherry).
TL;DR: The aformentioned results were interpreted as indicating the previous presence of phosphorylase in the preclimacteric phase without new synthesis during ripening, probably due to ribosomal synthesis rather than to nucleic acid synthesis.
Abstract: Starch levels as well as the phosphorylases and acid phosphatase activity during ripening of the banana fruit was investigated The concentrations and sequence of appearance of sucrose, glucose and fructose were determined by use of specific enzymatic reactions During the climacteric period, the phosphatase activity increased while phosphorylase activity, which initially increased before starch transformation began, thereafter decreased in a complex pattern The starch was transformed into sucrose with later formation of glucose and fructose Four bands of phosphorylase multiple forms, detected electrophoretically, did not change during ripening One of them was able to synthesize a branched starch-using amylose as a primer and glucose 1 -phosphate as the substrate Banana slices were infiltrated with water or solutions of cycloheximide or actinomycin D Inhibition of phosphatase-induced activity was recorded only in the cycloheximide group No change in phosphorylase activity was detected in any of these infiltrated groups Sucrose production from starch was partially inhibited both by actinomycin D and cycloheximide The aformentioned results were interpreted as indicating the previous presence of phosphorylase in the preclimacteric phase without new synthesis during ripening The increase of activity of phosphatase was probably due to ribosomal synthesis rather than to nucleic acid synthesis
TL;DR: Sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis show that the glycoproteins ABC and the lipopeptidophosphoglycan are 50- and 10-times more concentrated, respectively, in fractions V and M than in the whole cell homogenate.
TL;DR: The amount of food ingested by rats of both groups was lower than that ingested by the animals with free access to food (as evaluated in 24 hours); nevertheless, both food-restricted groups did not lose weight for the duration of the experiments.
TL;DR: Thalamotomy remains a useful analgesic procedure in patients with chronic pain and in patients who had bilateral center-median thalamotomy, which was superior to basal thalamotom and had fewer side effects.
TL;DR: In this paper, it was shown that the Bloch-Nordsieck inclusive cross sections are not in general infrared finite in non-abelian gauge theories treated by perturbation theory.
TL;DR: Results suggest that in patients with an unusual form of spondyloepiphyseal dysplasia excreted in the urine undersulfated chondroitin 6-sulfate, the skeletal lesions are secondary to a defect in the synthesis of chondDetroitin sulfate involving specifically the sulfotransferase activity.
TL;DR: The efferent connections of the olfactory bulb in the opossum (Didelphis marsupialis aurita) were studied by the aid of the Fink‐Heimer technique.
Abstract: The efferent concentrations of the olfactory bulb (OB) in the opossum (Didelphis marsupialis aurita) were studied by the aid of the Fink-Heimer technique. Following lesions restricted to the OB, ipsilateral degenerating fibers entered the lateral olfactory tract and were treated to terminal fields essentially limited to the outer portion of the plexiform layer (sublamina IA) of the following structures: all the subdivisions of the anterior olfactory nucleus, the rostroventral tenia tecta, the full extent of the olfactory tubercle, the nucleus of the lateral olfactory tract, the anterior portion of the medial amygdaloid nucleus, the whole cortical amygdaloid nucleus (in the posteromedial subdivision of this structure the degeneration was very scanty), and the sulcal, piriform, and lateral entorhinal cortices. Some degree of topographical organization in the OB projections was noticed in the rostral portion of the lateral olfactory tract and within the external and lateral subdivisions of the anterior olfactory nucleus. In another series of experiments, when the lesion also involved the accessory olfactory bulb, heavy terminal degeneration occurred along the whole extent of the medial amygdaloid nucleus and in the posteromedial subdivision of the cortical amygdaloid nucleus. These findings indicate that, although very similar to those described in other mammals, the OB efferent connections in the opossum present some peculiarities; namely, the existence of dense terminal fields in the sulcal cortex and in the rostral district of the medial amygdaloid nucleus.
TL;DR: In this paper, the relationship between the cratonic area and orogenic belts of the southern part of the state of Minas Gerais (Brazil) is analyzed using data from a recent Bouguer anomaly map.
TL;DR: The concomitant consideration of O/M values establishes the concept of generic unity, suggesting that dispersal of original stock from Asia to America and from forest to savanna was accompanied by the evolutionary blocking of the necessary oxidative enzymes.