Showing papers by "State University of Campinas published in 1994"
TL;DR: Hierarchical decomposition has proved to be an efficient heuristic for coping with nonconvexity, as illustrated in the test results section of the paper.
Abstract: This paper presents a hierarchical decomposition approach for optimal transmission network expansion planning. A major difficulty in obtaining global optimal solutions for complex, real-life networks is due to the nonconvexity of the problem. Hierarchical decomposition has proved to be an efficient heuristic for coping with nonconvexity, as illustrated in the test results section of the paper. Significant reductions in investment costs have been obtained in some practical cases for which results are available in the literature. The current implementation of the hierarchical decomposition approach utilizes three different levels of network modeling: transportation models, hybrid models, and linearized power flow models. An initial solution is obtained for the simplest model (transportation model) and as one moves towards the final solution the algorithm successively switches to more accurate models. >
388 citations
TL;DR: In this paper, the authors studied the existence of solutions for the elliptic upomega problem in a bounded open subset of the Euclidean space with smooth boundary, where the smooth boundary is bounded by a smooth boundary.
Abstract: In this article we study the existence of solutions for the elliptic system \( - \Updelta u = \frac{\partial H}{\partial v}\left( {u,v,x} \right)\,{\text{in}}\Upomega , \) \( - \Updelta v = \frac{\partial H}{\partial v}\left( {u,v,x} \right)\,{\text{in}}\Upomega , \) \( u = 0,v = 0\,{\text{on}}\,\partial \Upomega \)where \( \Upomega \) is a bounded open subset of \( {\mathbb{R}}^{N} \) with smooth boundary \( \partial \Upomega \) and the function H: \( {\mathbb{R}}^{2} \times \overline{\Upomega } \to {\mathbb{R}} \), is of class C 1.
297 citations
TL;DR: In this paper, the authors describe a neural network model based on the synaptic organization of the cerebellum that can generate timed responses in the range of tens of milliseconds to seconds, and demonstrate that a network based on cerebellar circuitry can learn appropriately timed responses by encoding time as the population vector of granule cell activity.
Abstract: Substantial evidence has established that the cerebellum plays an important role in the generation of movements. An important aspect of motor output is its timing in relation to external stimuli or to other components of a movement. Previous studies suggest that the cerebellum plays a role in the timing of movements. Here we describe a neural network model based on the synaptic organization of the cerebellum that can generate timed responses in the range of tens of milliseconds to seconds. In contrast to previous models, temporal coding emerges from the dynamics of the cerebellar circuitry and depends neither on conduction delays, arrays of elements with different time constants, nor populations of elements oscillating at different frequencies. Instead, time is extracted from the instantaneous granule cell population vector. The subset of active granule cells is time-varying due to the granule---Golgi---granule cell negative feedback. We demonstrate that the population vector of simulated granule cell activity exhibits dynamic, nonperiodic trajectories in response to a periodic input. With time encoded in this manner, the output of the network at a particular interval following the onset of a stimulus can be altered selectively by changing the strength of granule ’ Purkinje cell connections for those granule cells that are active during the target time window. The memory of the reinforcement at that interval is subsequently expressed as a change in Purkinje cell activity that is appropriately timed with respect to stimulus onset. Thus, the present model demonstrates that a network based on cerebellar circuitry can learn appropriately timed responses by encoding time as the population vector of granule cell activity.
243 citations
22 Oct 1994
TL;DR: This paper discusses a conceptual model of groupware consisting of three complementary components or models: a description of the objects and operations on these objects available in the system; a descriptions of the activities (and their orderings) that the users of the system can perform; and the interface of users with the system, and with other users.
Abstract: This paper discusses a conceptual model of groupware consisting of three complementary components or models: a description of the objects and operations on these objects available in the system; a description of the activities (and their orderings) that the users of the system can perform; and a description of the interface of users with the system, and with other users.
239 citations
TL;DR: A new model of Petri nets based on the use of logic based neurons is proposed, aimed at neural-type modeling of the entire concept with a full exploitation of the learning capabilities of the processing units being used there.
Abstract: The paper proposes a new model of Petri nets based on the use of logic based neurons. In contrast to the existing generalizations, this approach is aimed at neural-type modeling of the entire concept with a full exploitation of the learning capabilities of the processing units being used there. The places and transitions of the net are represented by OR and AND-type and DOMINANCE neurons, respectively. A correspondence between this model and the previous two-valued counterpart is also revealed. The learning aspects associated with the nets are investigated. >
175 citations
TL;DR: In this paper, a zero-one implicit enumeration method applied to an integer programming subproblem is proposed to obtain an optimal solution for a transmission expansion planning problem by hierarchical Benders decomposition.
Abstract: This paper presents a zero-one implicit enumeration method applied to an integer programming subproblem which has to be solved as part of a more general process of obtaining an optimal solution for a transmission expansion planning problem by hierarchical Benders decomposition. The proposed algorithm has been successfully implemented and tested in a real-life system. The reasons why the implicit enumeration approach is particularly suited for the static expansion planning problem are fully discussed in the paper. >
151 citations
TL;DR: The decentralized control problem for linear dynamic systems is revisited using a parameter space approach which enables the definition of the decentralized feedbacks from the existence of non-empty parameter convex sets.
147 citations
TL;DR: A priori estimates for solutions of superlinear elliptic problems can be established by a blow up technique as discussed by the authors, which has been used by Gidas-Spruck [GS1] for the case of a single equation.
Abstract: A priori estimates for solutions of superlinear elliptic problems can be established by a blow up technique. Such a method has been used by Gidas-Spruck [GS1] for the case of a single equation. Similar arguments can also be used in the case of systems. We refer to the work of Jie Qing [J] and M.A. Souto [S]. As in the scalar case, the treatment of systems poses the question of the validity of a result which is referred as a Liouville-type theorem for solutions of systems of elliptic equations in \( {\mathbb{R}}^{N} . \)
136 citations
TL;DR: In semideciduous forests where fleshy fruits are less abundant than in the wet forests capuchins are important seed predators and flowereaters, and several fruits eaten by capuchin in the dry season were not consumed by other frugivorous vertebrates, such as howler monkeys, parrots or squirrels, allowing capuchin monkeys to avoid competition with other arboreal frugIVores.
Abstract: The diet of capuchin monkeys, Cebus apella, in a 250 ha semideciduous forest in south-east Brazil was studied for 44 consecutive months. Based on 367 feeding bouts the diet of capuchins was 53.9% fruit pulp, 16.0% seeds, 11.1% flowers, 6.3% leaves and new shoots, 1.5% roots and 13.9% corn from plantations surrounding the forest. Seventy-one plant species were consumed by capuchins. Food availability was markedly seasonal. During the dry season the fleshy fruit availability decreased, and at that time the capuchins became seed predators and flower- eaters. Several fruits eaten by capuchins in the dry season were not consumed by other frugivorous vertebrates, such as howler monkeys, parrots or squirrels, allowing capuchins to avoid competition with other arboreal frugivores. In semideciduous forests where fleshy fruits are less abundant than in the wet forests capuchins are important seed predators.
135 citations
TL;DR: It is proved that the global convergence of the main algorithm and a result concerning the identification of the active constraints in finite time are correct.
Abstract: We introduce a new algorithm of trust-region type for minimizing a differentiable function of many variables with box constraints. At each step of the algorithm we use an approximation to the minimizer of a quadratic in a box. We introduce a new method for solving this subproblem, that has finite termination without dual nondegeneracy assumptions. We prove the global convergence of the main algorithm and a result concerning the identification of the active constraints in finite time. We describe an implementation of the method and we present numerical experiments showing the effect of solving the subproblem with different degrees of accuracy.
134 citations
TL;DR: In this article, a quantum chemical (AM1) combined with a classical study of structure-activity relationships for 1,4-dihydropyridines (nifedipine analogues) was performed.
TL;DR: In this paper, the change of workpiece surface roughness caused by the increase of tool wear, through the variation of the vibration in finish turning, under different cutting conditions, was measured by two accelerometers attached to the tool.
TL;DR: In the SJL model of EAE oral administration of an autoantigen from the target tissue suppresses disease independent of whether it is or is not the inciting antigen, which has important implications for the use of oral tolerance as a therapeutic approach for the treatment of T cell‐mediated inflammatory autoimmune diseases in man.
Abstract: Immunomodulatory treatment paradigms have been applied to animal models of T cell-mediated autoimmune diseases in an attempt to develop an immunospecific and non-toxic form of therapy which can be applied to humans. These treatment paradigms are often directed to T cells with a restricted T cell receptor repertoire or that react with dominant peptide determinants. Experimental data, however, suggests that even if the initial T cell response is restricted to a specific self-protein in the target organ, spreading autoimmunity may develop with broadening of T cell autoreactivity to additional epitopes of the same autoantigen or to different autoantigens in the target organ. Thus, multiple autoantigens may become targets of the autoimmune response. This makes immunotherapeutic strategies based on suppressing responses to restricted proteins or clones of cells problematic. We have previously shown that suppression of experimental autoimmune encephalomyelitis (EAE) in the Lewis rat by oral myelin basic protein (MBP) is mediated by the release of transforming growth factor-β after triggering by the oral tolerogen. Here, we report that in the SJL model of EAE oral administration of an autoantigen from the target tissue suppresses disease independent of whether it is or is not the inciting antigen. Thus, orally administered MBP or MBP peptides suppress proteolipid protein (PLP)-induced EAE, whereas intravenously administered MBP does not. Both oral and intravenous PLP, however, suppressed PLP disease. These findings have important implications for the use of oral tolerance as a therapeutic approach for the treatment of T cell-mediated inflammatory autoimmune diseases in man in which the inciting autoantigen is unknown or in which there is autoreactivity to multiple autoantigens in the target tissue.
Journal Article•
TL;DR: The clinical presentation and course of SLE may be influenced by the age at disease onset, as younger patients showed a poorer prognosis with more seizures, gastrointestinal involvement, nephrotic syndrome, and a higher rate of mortality than the other groups.
Abstract: OBJECTIVE To analyse the clinical and laboratory parameters in patients with SLE according to their age at disease onset a retrospective study was undertaken of 272 Brazilian patients fulfilling the 1982 ARA criteria for SLE who were referred to the University Hospital of Campinas between 1973-1992. METHODS The patients were divided into three groups according to their age at disease onset: Group A: under the age of 16 (39 patients); Group B age 17 to 49 (223 patients); Group C over the age of 50 (10 patients). Various clinical and laboratorial parameters were analysed and compared among these groups. RESULTS There were no significant differences in terms of race, time of disease onset or time of follow-up. Group A had more male patients than Groups B (p < 0.05) or C. Alopecia as an early manifestation, seizures and gastrointestinal involvement were more frequent in Group A (p < 0.05). Raynaud's phenomenon was lower in Group A than in Groups B and C (p < 0.05). Pericarditis was higher in Group C than in Groups A or B (p < 0.05). Nephrotic syndrome was lower in Group C than in Group A (p < 0.05). Positive LE cells were higher in Groups A and C than in Group B (p < 0.05). Anti-DNA antibodies were more prevalent in Group A than in B (p < 0.05). Anti-cardiolipin antibodies were more frequent in adult patients (p < 0.05) (Group B). The mortality rate was higher in Group A than in B or C (p < 0.05). CONCLUSION The clinical presentation and course of SLE may be influenced by the age at disease onset. Younger patients showed a poorer prognosis with more seizures, gastrointestinal involvement, nephrotic syndrome, and a higher rate of mortality than the other groups. Group A included more male patients and also exhibited more positive LE cells and anti-DNA antibodies. Raynaud's phenomenon was lower in these young patients. Elderly patients (C) presented more pericarditis and showed mild disease.
TL;DR: O presente trabalho procura resgatar de forma sintetica a trajetoria historica e conceitual da Saude Coletiva, evidenciando as suas raizes nos projetos preventivistas e da medicina social as discussed by the authors.
Abstract: O presente trabalho procura resgatar de forma sintetica a trajetoria historica e conceitual da "Saude Coletiva", evidenciando as suas raizes nos projetos preventivistas e da medicina social. Estes projetos, que se estenderam a partir dos anos 50 e que culminam com a ideia da chamada "Saude Coletiva", apresentam aspectos que os diferenciam na apreensao do social e do coletivo. Ao tratar especificamente da ideia de uma Saude Coletiva, o texto aponta para a sua triplice dimensao: como corrente de pensamento, como movimento social e como pratica teorica.
TL;DR: This study supports the idea that subjects with Down syndrome can use patterns of muscle activation that are qualitatively indistinguishable from those used by individuals who are neurologically normal.
Abstract: Background and Purpose. The purpose of this study was to investigate the effects of prolonged practice of a simple motor task (a fast, unidirectional single-joint movement) on different indexes of motor performance in individuals with Down syndrome. Subjects. Eight individuals with Down syndrome were tested before and after practice involving 1,100 movements. Methods. The test consisted of three series of elbow flexion movements. In the first series, the subjects were asked to move “as fast as possible” over four distances. In the second series, the subjects moved over one distance at a “comfortable speed.” The initial position of the elbow joint for these two series of movements was 55 degrees into flexion (full elbow extension equals 0°). In the third series, the subjects were also asked to move “as fast as possible” over two distances, but from another initial elbow position (73° into flexion). Results. After training over a 2-week period, all subjects improved their performance on all tasks as reflected by both kinematic and electromyographic data. In particular, they increased the quantity of the agonist activity, decreased the antagonist onset latency, and doubled their peak velocity. They were able to transfer the improvement in their performance to the nontrained distances and to the different starting position. Subjects decreased their movement time by proportionally decreasing both the acceleration and deceleration times. Conclusion and Discussion. This study supports the idea that subjects with Down syndrome can use patterns of muscle activation that are qualitatively indistinguishable from those used by individuals who are neurologically normal. With appropriate training, individuals with Down syndrome achieved similar levels of motor performance to that described in the literature for individuals who are neurologically normal.
TL;DR: It is proposed that the decreased density of intramembrane particles decreases the stability of the membrane lipid bilayer and causes release of lipid microvesicles that leads to surface area deficiency and spherocytosis.
Abstract: We describe a duplication of 10 nucleotides (2,455-2,464) in the band 3 gene in a kindred with autosomal dominant hereditary spherocytosis and a partial deficiency of the band 3 protein that is reflected by decreased rate of transmembrane sulfate flux and decreased density of intramembrane particles. The mutant allele potentially encodes an abnormal band 3 protein with a 3.5-kD COOH-terminal truncation; however, we did not detect the mutant protein in the membrane of mature red blood cells. Since the mRNA levels for the mutant and normal alleles are similar and since the band 3 content is the same in the light and dense red cell fractions, we conclude that the mutant band 3 is either not inserted into the plasma membrane or lost from the membrane prior to the release of red blood cells into circulation. We further show that the decrease in band 3 content principally involves the dimeric laterally and rotationally mobile fraction of the band 3 protein, while the laterally immobile and rotationally restricted band 3 fraction is left essentially intact. We propose that the decreased density of intramembrane particles decreases the stability of the membrane lipid bilayer and causes release of lipid microvesicles that leads to surface area deficiency and spherocytosis.
29 Jun 1994
TL;DR: In this paper, it was shown that the existence of an output feedback gain is equivalent to a positive definite matrix belonging to a convex set such that its inverse belongs to another convex setting.
Abstract: The main objective of this paper is to solve the following stabilizing output feedback control problem. Given matrices (A, B/sub 2/, C/sub 2/) with appropriate dimensions, find (if one exists), a static output feedback gain L such that the closed-loop matrix A-B/sub 2/LC/sub 2/ is asymptotically stable. Using linear matrix inequalities, it is shown that the existence of L is equivalent to the existence of a positive definite matrix belonging to a convex set such that its inverse belongs to another convex set. Conditions are provided for global convergence of the min/max algorithm which decomposes the determination of the aforementioned matrix by a sequence of convex programs. Some examples borrowed from the literature are solved hi order to illustrate the theoretical results.
TL;DR: In this article, a linear-quadratic penalty approach is applied to enforce the coupling between hydro and electric variables, and the problem's natural network flow structure is fully exploited through special-purposed network flow algorithms.
Abstract: This paper is concerned with the short-term hydrothermal scheduling (STHS) of hydro-dominated power systems. The problem's formulation includes the representation of operational constraints such as the hydraulic coupling between hydro plants in cascade and the transmission limits in the electric network. In order to allow the problem's decomposition into hydraulic and electric subproblems, a linear-quadratic penalty approach is applied to enforce the coupling between hydro and electric variables. As a result, the problem's natural network flow structure is fully exploited through special-purposed network flow algorithms. The technique has been implemented in FORTRAN in a SUN SPARCstation IPX and tested in a 440 kV subsystem of the main interconnected Brazilian power system. >
TL;DR: A Brazilian family with hereditary gingival fibromatosis was described in this article with multiple affected subjects in four generations and a total of 50 (48%), of 105 at-risk offspring in a family of 132 members were affected, consistent with an autosomal dominant mode of inheritance.
TL;DR: It is shown how the transition between those two fundamentally different states occurs, employing quasiprobability distributions in phase space, and is provided, at the same time, an interesting picture for the origin of second-order quadrature squeezing.
Abstract: We investigate the nonclassical properties of the single-mode binomial states of the quantized electromagnetic field. We concentrate our analysis on the fact that the binomial states interpolate between the coherent states and the number states, depending on the values of the parameters involved. We discuss their statistical properties, such as squeezing (second and fourth order) and sub-Poissonian character. We show how the transition between those two fundamentally different states occurs, employing quasiprobability distributions in phase space, and we provide, at the same time, an interesting picture for the origin of second-order quadrature squeezing. We also discuss the phase properties of the binomial states using the Hermitian-phase-operator formalism.
Book•
01 Jan 1994TL;DR: In this chapter, a short description of Weber’s life and some of his experimental researches in electromagnetism are presented.
Abstract: In this chapter we present a short description of Weber’s life and some of his experimental researches in electromagnetism. For a biography of Weber and further references see, for instance, (Woodruff, 1976), (Jungnickel and McCormmach, 1986), (Atherton, 1989), (Thomson, 1885), (O’Rahilly, 1965, Vol. 2, Chapter 11), (Whittaker, 1973, Vol. 1, Chapter 7), (Wise, 1981), (Assis, 1991 a), (Harman, 1982, pp. 32, 96 and 103 – 107), (Archibald, 1989).
TL;DR: Histologic type and tumor weight were the most reliable predictors of outcome in PACN, while proliferative index was marginally related to failure.
Abstract: Although the relationship between pathologic features and clinical outcome is well established in adult adrenocortical neoplasms, the prognostic value of these features in pediatric adrenocortical neoplasms (PACN) is unclear. In a series of PACNs from 54 Brazilian children, the authors retrospectively investigated the prognostic value of histologic classification, ploidy, proliferative index, and size (as tumor weight or greatest diameter). Histologic classification was most predictive of clinical behavior: there were no failures in 11 adenomas, 5 failures in 27 low-grade carcinomas, and 9 failures in 16 high-grade carcinomas ( P = .0003). Tumor weight was predictive of failure in tumors weighing ≥ 100 versus < 100 g ( P = .04), and a trend was found toward failure among tumors measuring ≥ 5 cm, as opposed to those < 5cm ( P = .07). Proliferative index was marginally related to failure ( P = .05 at < 11% vs. ≥ 11% and .07 at < 10% vs. ≥ 10%), and ploidy was not significantly predictive of outcome ( P = .25). Histologic type and tumor weight were the most reliable predictors of outcome in PACN.
TL;DR: In this paper, a review of FIR laser lines from CH[sub 3]OH was presented, and the authors extended this work to the other methanol isotopes, namely CH[ sub 3]OD, CD[sub 2]OH, CHD[sub 1]OD and CHD [sub 2]-OD.
Abstract: The technique of optical pumping in polar molecules is the most efficient for Far-Infrared (FIR) laser generation, providing also a versatile and powerful tool for molecular spectroscopy in this spectral region. Methanol (CH[sub 3]OH) and its isotopic varieties are the best media for optically pumped FIR laser, with over thousand lines observed, and the most widely used for investigations and applications. In this sense, it is important to organize and make available catalogues of FIR laser lines as complete as possible. Since the last critical reviews of 1984 on methanol and its isotopic varieties, over a hundred papers have been published dealing with hundreds of new FIR laser lines. In 1992 a review of FIR laser lines from CH[sub 3]OH was presented. In this communication we extend this work to the other methanol isotopes, namely CH[sub 3]OD, CD[sub 3]OH, CD[sub 3]OD, [sup 13]CH[sub 3]OH, [sup 13]CD[sub 3]OH, [sup 13]CD[sub 3]OD, CH[sub 3][sup 18]OH, CH[sub 2]DOH, CHD[sub 2]OH and CH[sub 2]DOD. 82 refs., 11 tabs.
TL;DR: The relationship between the original time pulse and the depth pulse after migration can be explained and quantified in terms of a prestack, Kirchhoff type, diffraction stack migration theory.
Abstract: When migrating seismic primary reflections obtained from arbitrary source‐receiver configurations (e.g., common shot or constant offset) into depth, a pulse distortion occurs along the reflector. This distortion exists even if the migration was performed using the correct velocity model. Regardless of the migration algorithm, this distortion is a consequence of varying reflection angle, reflector dip, and/or velocity variation. The relationship between the original time pulse and the depth pulse after migration can be explained and quantified in terms of a prestack, Kirchhoff‐type, diffraction‐stack migration theory.
TL;DR: Intravaginal misoprostol at the dose of 100 micrograms every 12 hours appears to be a safe, effective, practical, and inexpensive new method for induction of labor in intrauterine fetal death.
TL;DR: A close relationship between moisture, pretein and ash vaiues was found, suggesting the possibility of using the resulting charqui A(w) value as a parameter to define the product instead of the official moisture and mineral residue contents.
TL;DR: Radio-isotope studies indicated not only that l-tryptophan can serve as carbon source for synthesis of the trypanocide, violacein by Chromobacterium violaceum but also that isatin and indole 3-acetic acid are both important metabolic intermediates.
Abstract: Radio-isotope studies indicated not only that l-tryptophan can serve as carbon source for synthesis of the trypanocide, violacein by Chromobacterium violaceum (BB-78 strain) but also that isatin and indole 3-acetic acid are both important metabolic intermediates. Using 3-indolyl [2-14C] and [1-14C] acetic acid, it was found that the carboxylic carbon was not eliminated and that indole-3-acetic acid was incorporated intact into the pigment structure. N-Ethyl(5-hydroxy-indol-3-yl)-2-indolylethylamide is also an important metabolic intermediate in the violacein biosynthesis. This is the first report of a metabolic scheme for violacein synthesis which includes an intermediate other than l-tryptophan.
TL;DR: The diet of a group of six brown howlers was studied weekly during 12 months in a reserve of 250 ha of secondary, mesophytic, semi-deciduous forest and was poorer in fruits and richer in young leaves of lianas in comparison to other howler monkey species studies, probably as a consequence of the liana abundance in this forest fragment.
Abstract: The diet of a group of six brown howlers was studied weekly during 12 months in a reserve of 250 ha of secondary, mesophytic, semi-deciduous forest. The phenology of 186 trees of 72 species and 29 families was monitored simultaneously. Scan sampling was used to record the diet from dawn until dusk on a total of 60 days of observation, yielding 718 hr of animal-observer contact and 2,943 feeding scans. The diet was composed of leaves (73%), flowers (12%), and fruits (5%), from 68 identified plant species.Celtis iguanae, Cassia ferruginea, andInga spp. were the main food sources, accounting for approximately 50% of the diet. Young leaves (59%) were preferred to mature leaves (31%), trees contributing 56% and lianas 41% of the leaf diet. The ingestion of young leaves was correlated to the availability of these items, however, the correlations were not significant for flowers and fruits. The diet was poorer in fruits and richer in young leaves of lianas in comparison to other howler monkey species studies, probably as a consequence of the liana abundance in this forest fragment.
TL;DR: In this article, an alternative extraction procedure was developed, consisting in the extraction of boron with a 1.25 g/L solution of barium chloride (BaCl2) or with water heated in a domestic microwave oven.
Abstract: Extraction with hot water is the most widely used procedure to determine boron (B) in soils for the diagnosis of the nutrient availability for plants. However, this procedure is tedious for routine conditions and requires some special precautions. An alternative extraction procedure was developed, consisting in the extraction of B with a 1.25 g/L solution of barium chloride (BaCl2) or with water heated in a domestic microwave oven. Boron was determined either by inductively coupled argon plasma emission spectrometry (ICP‐AES) and by spectrophotometry with azomethine‐H. Good correlations were found between the extraction by boiling water under reflux and the extraction by the microwave heating for 13 Brazilian soils, and the contents of B obtained by spectrophotometry did not differ significantly from those obtained by ICP‐AES. Considering the calculated standard deviations, it can be concluded that microwave heating followed by ICP‐AES determination is an adequate procedure for the determination ...