Showing papers by "State University of Campinas published in 1999"

Nonmonotone Spectral Projected Gradient Methods on Convex Sets

Abstract: Nonmonotone projected gradient techniques are considered for the minimization of differentiable functions on closed convex sets. The classical projected gradient schemes are extended to include a nonmonotone steplength strategy that is based on the Grippo--Lampariello--Lucidi nonmonotone line search. In particular, the nonmonotone strategy is combined with the spectral gradient choice of steplength to accelerate the convergence process. In addition to the classical projected gradient nonlinear path, the feasible spectral projected gradient is used as a search direction to avoid additional trial projections during the one-dimensional search process. Convergence properties and extensive numerical results are presented.

Fast Multiplication on Elliptic Curves over GF(2m) without Precomputation

Abstract: This paper describes an algorithm for computing elliptic scalar multiplications on non-supersingular elliptic curves defined over GF(2m). The algorithm is an optimized version of a method described in [1], which is based on Montgomery's method [8]. Our algorithm is easy to implement in both hardware and software, works for any elliptic curve over GF(2m), requires no precomputed multiples of a point, and is faster on average than the addition-subtraction method described in draft standard IEEE P1363. In addition, the method requires less memory than projective schemes and the amount of computation needed for a scalar multiplication is fixed for all multipliers of the same binary length. Therefore, the improved method possesses many desirable features for implementing elliptic curves in restricted environments.

O acolhimento e os processos de trabalho em saúde: o caso de Betim, Minas Gerais, Brasil

Abstract: The subject of this paper is changes in health care when "user embracement" is used as a strategic aim. According to the "user embracement" concept, health care clients are the center of the health services' organization, including the following: 1) care for everyone seeking it, thus guaranteeing universal accessibility; 2) reorganization of the work process, such that its central thrust is shifted from the physician to the multiprofessional staff, or "user embracement team", in charge of "hearing" users and becoming involved in solving their health problems; and 3) solidarity, humanity, and citizenship as parameters for the relationship between health care users and providers. The research showed improvement of non-medical health care productivity and greater accessibility by users. After nine months, the "user embracement team" solved 50% of the health problems themselves. The above-mentioned effects were also linked to workers' motivation, leading to greater creativity in the work process.

On higher order statistics of the Nakagami-m distribution

Abstract: This paper proposes a fading model that leads to a formal, but simple method to obtain the exact formula of the Nakagami-m published in 1960 distribution for m=n/2, with n a nonzero integer number. Based on such a model, the joint distribution of the envelope and its time derivative are accomplished, and exact formulas for the level crossing rate (closed-form formula) and for the average fade duration are derived. Simulation curves and exact formulas are checked against each other and a very good agreement between them is attained. Although derived for discrete values of m (m being an integer multiple of 1/2), there are no mathematical constraints for these expressions to be used for any real value of m/spl ges/1/2.

On the Generation of Spatiotemporal Datasets

Abstract: An efficient benchmarking environment for spatiotemporal access methods should at least include modules for generating synthetic datasets, storing datasets (real datasets included), collecting and running access structures, and visualizing experimental results. Focusing on the dataset repository module, a collection of synthetic data that would simulate a variety of real life scenarios is required. Several algorithms have been implemented in the past to generate static spatial (point or rectangular) data, for instance, following a predefined distribution in the workspace. However, by introducing motion, and thus temporal evolution in spatial object definition, generating synthetic data tends to be a complex problem. In this paper, we discuss the parameters to be considered by a generator for such type of data, propose an algorithm, called "Generate_Spatio_Temporal_Data" (GSTD), which generates sets of moving point or rectangular data that follow an extended set of distributions. Some actual generated datasets are also presented. The GSTD source code and several illustrative examples are currently available to all researchers through the Internet.

Optimal linear filtering under parameter uncertainty

Abstract: This paper addresses the problem of designing a guaranteed minimum error variance robust filter for convex bounded parameter uncertainty in the state, output, and input matrices. The design procedure is valid for linear filters that are obtained from the minimization of an upper bound of the error variance holding for all admissible parameter uncertainty. The results provided generalize the ones available in the literature to date in several directions. First, all system matrices can be corrupted by parameter uncertainty, and the admissible uncertainty may be structured. Assuming the order of the uncertain system is known, the optimal robust linear filter is proved to be of the same order as the order of the system. In the present case of convex bounded parameter uncertainty, the basic numerical design tools are linear matrix inequality (LMI) solvers instead of the Riccati equation solvers used for the design of robust filters available in the literature to date. The paper that contains the most important and very recent results on robust filtering is used for comparison purposes. In particular, it is shown that under the same assumptions, our results are generally better as far as the minimization of a guaranteed error variance is considered. Some numerical examples illustrate the theoretical results.

Magnetic ordering effects in the Raman spectra of La 1 − x Mn 1 − x O 3

Abstract: Temperature-dependent Raman spectra of polycrystalline ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{O}}_{3}$ samples, referred to as ${\mathrm{LaMnO}}_{3+\ensuremath{\delta}}$ for convenience, were correlated to their structural and magnetic properties for different $\ensuremath{\delta}.$ For $\ensuremath{\delta}l~0.05,$ a softening of the $\ensuremath{\sim}610 {\mathrm{cm}}^{\ensuremath{-}1}$ Raman mode is observed below the magnetic ordering temperature. This softening is reduced as $\ensuremath{\delta}$ increases from 0.00 to 0.05. This behavior is not associated with lattice anomalies, and is interpreted in terms of a spin-phonon coupling caused by a phonon modulation of the superexchange integral. A quantitative analysis of this effect is presented.

Electrochemically assisted photocatalytic degradation of reactive dyes

Abstract: The aim of this study was to investigate the efficiency of the electrochemically assisted photocatalytic process in the degradation of C. I. Reactive Blue 19 on a Ti/Ru 0,3 Ti 0,7 O 2 electrode. By using the quartz device and the Ti-supported noble metal oxide coating, decolorizations ratios higher than 95% and TOC reduction of about 52% were observed during a period of 120 min. Comparing this value with the sum of the decolorization ratios obtained by a single application of electrochemical and photochemical procedures, it is possible to observe a significant synergic effect between both processes. The electrochemical process was conduced at 28°C (refrigeration with air) and pH of 11.0, and with a constant potential of 1.8 V versus Ag/AgCl. With these conditions, the mean current was 23 mA. The voltammetric results also confirm the synergic effect of the simultaneous process.

Equipes de referência e apoio especializado matricial: um ensaio sobre a reorganização do trabalho em saúde

Abstract: Este artigo propoe um novo arranjo organizacional para o trabalho em saude. E desenvolvido e ampliado o conceito de equipe de referencia - proposto e experimentado pelo autor desde 1989. E tambem reelaborado o conceito de organizacao matricial do trabalho, invertendo-se em relacao ao esquema original o que seria permanente e aquilo que seria transitorio (recorte matricial) nos servicos de saude. Sao tambem apresentadas consideracoes teoricas que autorizam e justificam a construcao desta nova proposta.

Quimiometria I: calibração multivariada, um tutorial

Abstract: The aim of this work is to present a tutorial on Multivariate Calibration, a tool which is nowadays necessary in basically most laboratories but very often misused. The basic concepts of preprocessing, principal component analysis (PCA), principal component regression (PCR) and partial least squares (PLS) are given. The two basic steps on any calibration procedure: model building and validation are fully discussed. The concepts of cross validation (to determine the number of factors to be used in the model), leverage and studentized residuals (to detect outliers) for the validation step are given. The whole calibration procedure is illustrated using spectra recorded for ternary mixtures of 2,4,6 trinitrophenolate, 2,4 dinitrophenolate and 2,5 dinitrophenolate followed by the concentration prediction of these three chemical species during a diffusion experiment through a hydrophobic liquid membrane. MATLAB software is used for numerical calculations. Most of the commands for the analysis are provided in order to allow a non-specialist to follow step by step the analysis.

Interaction between ants, extrafloral nectaries and insect herbivores in Neotropical coastal sand dunes: herbivore deterrence by visiting ants increases fruit set in Opuntia stricta (Cactaceae)

Abstract: 1. This study examines the anti-herbivore effect of ants visiting the extrafloral nectaries (EFNs) of Opuntia stricta (Cactaceae) and its possible influence on the plant’s reproductive output in Mexican coastal sand dunes. Opuntia’s EFNs are located in the areoles of the developing tissue of emerging cladodes and flower buds. 2. Ants visited the EFNs of O. stricta on a round-the-clock basis. The associated ant assemblage was formed by nine species distributed in four subfamilies, and the species composition of the principal ant visitors changed markedly from day to night period. 3. Cladodes of control (ants present) and treatment (ants excluded) plants of Opuntia were equally infested by sucking bugs and mining dipterans. Damage to buds by a pyralid moth, however, was significantly higher on treatment than on control plants. Ant visitation to Opuntia’s EFNs translated into a 50% increase in the plant’s reproductive output, as expressed by the number of fruits produced by experimental control and treatment branches. Moreover, fruit production by ant-visited branches was positively and significantly associated with the mean monthly rate of ant visitation to EFNs. 4. This is the first demonstration of ant protection leading to increased fruit set in the Cactaceae under natural conditions. Although the consequences of damage by sucking and mining insects remain unclear for Opuntia, the results show how the association of EFNs with vulnerable reproductive plant organs can result in a direct ant-derived benefit to plant fitness.

Endemic regions of paracoccidioidomycosis in Brazil: a clinical and epidemiologic study of 584 cases in the southeast region.

Abstract: This paper describes the clinical-seroepidemiologic characteristics of patients with paracoccidioidomycosis (PCM) who visited the University Hospital at the State University of Campinas (Campinas, Sao Paulo, Brazil). The study group consisted of 584 individuals (492 males and 92 females) with ages ranging from 5 to 87 years. The highest incidence of the disease occurred between the ages of 41 and 50 years for men and between 11 and 40 years for women. Rural activities were the principal occupation of 46% of the patients. The diagnosis was confirmed by histopathologic examination and demonstration of fungus in scrapings, secretions, or in the sputum. Serologic test results for PCM were positive in 80% of the 584 patients studied. The significant number of patients, including 33 children less than 14 years old, indicates the presence of the fungus in the area and that this region is an important endemic area for PCM.

Ca2+-induced increased lipid packing and domain formation in submitochondrial particles. A possible early step in the mechanism of Ca2+-stimulated generation of reactive oxygen species by the respiratory chain.

Abstract: Ca2+ and Pi accumulation by mitochondria triggers a number of alterations leading to nonspecific increase in inner membrane permeability [Kowaltowski, A. J., et al. (1996) J. Biol. Chem. 271, 2929−2934]. The molecular nature of the membrane perturbation that precedes oxidative damage is still unknown. EPR spectra of spin probes incorporated in submitochondrial particles (SMP) and in model membranes suggest that Ca2+−cardiolipin (CL) complexation plays an important role. Ca2+-induced lipid domain formation was detected in SMP but not in mitoplasts, in SMP extracted lipids, or in CL-containing liposomes. The results were interpreted in terms of Ca2+ sequestration of CL tightly bound to membrane proteins, in particular the ADP−ATP carrier, and formation of CL-enriched strongly immobilized clusters in lipid shells next to boundary lipid. The in-plane lipid and protein rearrangement is suggested to cause increased reactive oxygen species production in succinate-supplemented, antimycin A-poisoned SMP, favoring ...

Effects of selective logging on a bird community in the Brazilian Atlantic forest

Abstract: I evaluated the effects of selectie logging upon a bird community in the Brazilian Atlantic forest. Two areas 500 m apart were selected for quantitative (point censuses) avian surveys: a non-fragmented primary forest (PF) and a selectively logged forest (LF). Six of eight quanitative measures of vegetation structure compared between PF and LF were reduced at LF. Indices of avian species richness and diversity were very similar between PF and LF sites; species composition, however, differed strongly. Although the composition of guilds remained largely the same, most guilds differed in membership between PF and LF in at least one species. Understory and terrestrial insectivores were the mot sensitive ecological groups (with most species missing in LF), as also observed in the process of forest fragmentation in other parts of the Neotropics. Based on the results of this study, I recommend the following procedures to minimize adverse effects of selective loging on bird communities in the Atlantic forest: (1) logged areas should be close enough to unfragmented, unlogged forest to allow recolonization of some species, (2) the exploitation of the forest should be carried out using as few roads and as little mechanized equipment as possible, and (3) long-term rotation should be used in areas designed for logging to allow time for forest regeneration.

An LMI optimization approach to multiobjective controller design for discrete-time systems

Abstract: In this paper we investigate the design of multiobjective controllers for linear discrete-time systems. We show that, as for the H/sub 2/ norm, it is possible to extend the linear matrix inequality (LMI) characterization of the H/sub /spl infin// norm condition so that it no longer exhibits the product of the Lyapunov matrix and the system dynamic matrices. Then we develop a parametrization for state-feedback and output-feedback linear controllers which linearizes these extended H/sub 2/ and H/sub /spl infin// norm conditions for synthesis. These parametrizations are applied to the design of controllers with multiobjective constraints. A numerical example illustrates the results and provide a comparison with some of the existing methods.

Carotenoids from guava (Psidium guajava l.): isolation and structure elucidation.

Abstract: Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV−visible, 400 and 500 MHz 1H NMR, 120 and 125 MHz 13C NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-β-carotene, (all-E)-γ-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-β-cryptoxanthin, (all-E,3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3‘R,6‘R)-lutein, (all-E,3S,5R,6R,3‘S,5‘R,8‘R)-, and (all-E,3S,5R,6R,3‘S,5‘R,8‘S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time. Keywords: Carotenoids; isolation; LC/MS; NMR; guava; Psidium guajava L.