Showing papers by "University of São Paulo published in 2000"

Democracy and Development: Political Institutions and Well-Being in the World, 1950–1990

Abstract: Introduction 1. Democracies and dictatorships 2. Dynamic of political regimes 3. Political regimes and economic growth 4. Political instability and economic growth 5. Political regimes and population Conclusion.

Subcutaneous and visceral adipose tissue : Their relation to the metabolic syndrome

Abstract: Methods for assessment, e.g., anthropometric indicators and imaging techniques, of several phenotypes of human obesity, with special reference to abdominal fat content, have been evaluated. The correlation of fat distribution with age, gender, total body fat, energy balance, adipose tissue lipoprotein lipase and lipolytic activity, adipose tissue receptors, and genetic characteristics are discussed. Several secreted or expressed factors in the adipocyte are evaluated in the context of fat tissue localization. The body fat distribution and the metabolic profile in nonobese and obese individuals is discussed relative to lipolysis, antilypolysis and lipogenesis, insulin sensitivity, and glucose, lipid, and protein metabolism. Finally, the endocrine regulation of abdominal visceral fat in comparison with the adipose tissue localized in other areas is presented.

Propolis: recent advances in chemistry and plant origin

Abstract: New information published since 1995 about propolis constituents is reviewed. The available information on the biological action of new found components is presented. Recent publi- cations are reviewed on propolis of native South American stingless bees. The plant sources of bee glue are discussed, taking into consideration data based on reliable chemical evidence including comparisons between propolis samples and plant material. Some aspects of the chemical standard- ization of propolis are discussed.

The genome sequence of the plant pathogen Xylella fastidiosa

Abstract: Instituto Ludwig de Pesquisa sobre o Câncer, Rua Prof. Antonio Prudente, 109-4 andar, 01509-010, Sao Paulo-SP

Microsatellite markers reveal a spectrum of population structures in the malaria parasite Plasmodium falciparum.

Abstract: Multilocus genotyping of microbial pathogens has revealed a range of population structures, with some bacteria showing extensive recombination and others showing almost complete clonality. The population structure of the protozoan parasite Plasmodium falciparum has been harder to evaluate, since most studies have used a limited number of antigen-encoding loci that are known to be under strong selection. We describe length variation at 12 microsatellite loci in 465 infections collected from 9 locations worldwide. These data reveal dramatic differences in parasite population structure in different locations. Strong linkage disequilibrium (LD) was observed in six of nine populations. Significant LD occurred in all locations with prevalence <1% and in only two of five of the populations from regions with higher transmission intensities. Where present, LD results largely from the presence of identical multilocus genotypes within populations, suggesting high levels of self-fertilization in populations with low levels of transmission. We also observed dramatic variation in diversity and geographical differentiation in different regions. Mean heterozygosities in South American countries (0.3-0.4) were less than half those observed in African locations (0. 76-0.8), with intermediate heterozygosities in the Southeast Asia/Pacific samples (0.51-0.65). Furthermore, variation was distributed among locations in South America (F:(ST) = 0.364) and within locations in Africa (F:(ST) = 0.007). The intraspecific patterns of diversity and genetic differentiation observed in P. falciparum are strikingly similar to those seen in interspecific comparisons of plants and animals with differing levels of outcrossing, suggesting that similar processes may be involved. The differences observed may also reflect the recent colonization of non-African populations from an African source, and the relative influences of epidemiology and population history are difficult to disentangle. These data reveal a range of population structures within a single pathogen species and suggest intimate links between patterns of epidemiology and genetic structure in this organism.

Output feedback control of Markov jump linear systems in continuous-time

Abstract: This paper addresses the dynamic output feedback control problem of continuous-time Markovian jump linear systems. The fundamental point in the analysis is an LMI characterization, comprising all dynamical compensators that stabilize the closed-loop system in the mean square sense. The H/sub 2/ and H/sub /spl infin//-norm control problems are studied, and the H/sub 2/ and H/sub /spl infin// filtering problems are solved as a by product.

EthoLog 2.2: A tool for the transcription and timing of behavior observation sessions

Abstract: EthoLog is a tool that aids in the transcription and timing of behavior observation sessions--experimental or naturalistic, from video/audio tapes or registering real time. It was created with Visual Basic and runs on Windows (3.x/9x). The user types the key codes for the predefined behavioral categories, and EthoLog registers their sequence and timing and saves the resulting data in ASCII output files. A sequential analysis matrix can be generated from the sequential data. The output files may be edited, converted to plain text files for printing, or exported to a spreadsheet program, such as MS Excel, for further analyses.

Daily load profiles for residential, commercial and industrial low voltage consumers

Abstract: This paper presents the results of the study carried out for the determination of the residential, commercial and industrial consumers daily load curves based on field measurements performed by the Utilities of Electric Energy of Sao Paulo State, Brazil. A methodology for the aggregation of these loads to determine the expected loading in equipment of in a preset part of the distribution network by using the representative daily curves of each consumer's activity and the monthly energy consumption of the connected consumers is also presented.

Methanol oxidation on PtRu electrodes. Influence of surface structure and Pt-Ru atom distribution

Abstract: The activities of different types of PtRu catalysts for methanol oxidation are compared. Materials used were: UHV-cleaned PtRu alloys, UHV-evaporated Ru onto Pt(111) as well as adsorbed Ru on Pt(111) prepared with and without additional reduction by hydrogen. Differences in the catalytic activity are observed to depend on the preparation procedure of the catalysts. The dependence of the respective catalytic activities upon the surface composition is reported. UHV−STM data for Pt(111)/Ru show the formation of two- and three-dimensional structures depending on surface coverage. A molecular insight on the electrochemical reaction is given via in situ infrared spectroscopy. Analysis of the data indicates that the most probable rate-determining step is the reaction of adsorbed CO with Ru oxide.

Mutations in TGIF cause holoprosencephaly and link NODAL signalling to human neural axis determination

Abstract: Holoprosencephaly (HPE) is the most common structural defect of the developing forebrain in humans (1 in 250 conceptuses, 1 in 16,000 live-born infants1,2,3). HPE is aetiologically heterogeneous, with both environmental and genetic causes4,5. So far, three human HPE genes are known: SHH at chromosome region 7q36 (ref. 6); ZIC2 at 13q32 (ref. 7); and SIX3 at 2p21 (ref. 8). In animal models, genes in the Nodal signalling pathway, such as those mutated in the zebrafish mutants cyclops (refs 9,10), squint (ref. 11) and one-eyed pinhead (oep; ref. 12), cause HPE. Mice heterozygous for null alleles of both Nodal and Smad2 have cyclopia13. Here we describe the involvement of the TG-interacting factor (TGIF), a homeodomain protein, in human HPE. We mapped TGIF to the HPE minimal critical region in 18p11.3. Heterozygous mutations in individuals with HPE affect the transcriptional repression domain of TGIF, the DNA-binding domain or the domain that interacts with SMAD2. (The latter is an effector in the signalling pathway of the neural axis developmental factor NODAL, a member of the transforming growth factor-β (TGF-β) family.) Several of these mutations cause a loss of TGIF function. Thus, TGIF links the NODAL signalling pathway to the bifurcation of the human forebrain and the establishment of ventral midline structures.

Chemical characterization of leptin-activated neurons in the rat brain.

Abstract: Leptin has profound effects on food intake, body weight, and neuroendocrine status. The lack of leptin results in hormonal and metabolic alterations and a dramatic increase in body weight. Leptin acts in the brain, especially in the hypothalamus; however, the central nervous system sites that respond to leptin have not been examined comprehensively. In this study, we explored systematically the distribution of leptin-activated neurons throughout the rat brain. Furthermore, we investigated the chemical identity of subsets of these leptin-activated cells. Fos-like immunoreactivity (Fos-IR) was investigated in the rat brain after two different doses of leptin (1.0 mg/kg and 5.0 mg/kg) at 2 hours and 6 hours after injections. The induction of Fos-IR was observed in hypothalamic nuclei, including the paraventricular nucleus (PVH), the retrochiasmatic area (RCA), the ventromedial nucleus (VMH), the dorsomedial nucleus (DMH), the arcuate nucleus (Arc), and the ventral premammillary nucleus (PMV). In addition, leptin-induced Fos-IR was found in several nuclei of the brainstem, including the superior lateral and external lateral subdivisions of the parabrachial nucleus (slPB and elPB, respectively), the supragenual nucleus, and the nucleus of the solitary tract (NTS). By using double-labeling immunohistochemistry or immunohistochemistry coupled with in situ hybridization, leptin-activated neurons were found that contained cocaine- and amphetamine-regulated transcript mRNA in several hypothalamic nuclei, including the RCA, Arc, DMH, and PMV. In the Arc and DMH, leptin-induced Fos-IR was observed in neurons that expressed neurotensin mRNA. Dynorphin neurons in the VMH and in the Arc also expressed Fos-IR. In the brainstem, we found that cholecystokinin neurons in the slPB and glucagon-like peptide-1 neurons in the NTS were activated by leptin. We also investigated the coexpression of Fos-IR and the long form of the leptin receptor (OBRb) mRNA. We found double-labeled neurons surrounding the median eminence and in the RCA, Arc, VMH, DMH, and PMV. However, in brainstem sites, very little OBRb mRNA was found; thus, there were very few double-labeled cells. These results suggest that leptin stimulates brain pathways containing neuropeptides that are involved in the regulation of energy balance, autonomic homeostasis, and neuroendocrine status.

Shifting obesity trends in Brazil.

Abstract: Objective: To describe secular trends in obesity in various settings and socio-economic groups of the adult population of Brazil. Methods: Trend analysis of the prevalence of obesity in adults aged over 20 y (body mass index ≥30.0 kg/m2) applied to anthropometric and socio-economic data collected by three comparable household surveys undertaken in the two most populated Brazilian regions in 1975 (n=95, 062), 1989 (n=15, 585) and 1997 (n=10, 680). Results: While previous trends (1975–1989) showed increasing obesity prevalence for all population groups except for men in rural areas, recent trends (1989–1997) have pointed to a much more complex picture where increases in obesity tend to be more intense in men than in women, in rural than in urban settings and in poorer than in richer families. Particularly notable was the fact that, in the recent period, obesity was actually reduced for women belonging to the upper income groups, especially in urban settings. Conclusion: Earlier obesity trends in Brazil entirely agree with what has been described for both developed and developing countries where reliable secular trend information exists, but the 1989–1997 trend of a substantial reduction in the prevalence of obesity among upper income urban women (12.8–9.2%, or a 28% reduction), is unique in a developing country and, indeed, up to now has only been detected in Scandinavian populations. It is speculated that this declining obesity trend may be a result of an intense mass media work focused on combating a sedentary life style and promoting better food habits. European Journal of Clinical Nutrition (2000) 54, 342–346

Radiosurgery for brain metastases: a score index for predicting prognosis

Abstract: Purpose: To analyze a prognostic score index for patients with brain metastases submitted to stereotactic radiosurgery (the Score Index for Radiosurgery in Brain Metastases [SIR]). Methods and Materials: Actuarial survival of 65 brain metastases patients treated with radiosurgery between July 1993 and December 1997 was retrospectively analyzed. Prognostic factors included age, Karnofsky performance status (KPS), extracranial disease status, number of brain lesions, largest brain lesion volume, lesions site, and receiving or not whole brain irradiation. The SIR was obtained through summation of the previously noted first five prognostic factors. Kaplan-Meier actuarial survival curves for all prognostic factors, SIR, and recursive partitioning analysis (RPA) (RTOG prognostic score) were calculated. Survival curves of subsets were compared by log-rank test. Application of the Cox model was utilized to identify any correlation between prognostic factors, prognostic scores, and survival. Results: Median overall survival from radiosurgery was 6.8 months. Utilizing univariate analysis, extracranial disease status, KPS, number of brain lesions, largest brain lesion volume, RPA, and SIR were significantly correlated with prognosis. Median survival for the RPA classes 1, 2, and 3 was 20.19 months, 7.75 months, and 3.38 months respectively ( p = 0.0131). Median survival for patients, grouped under SIR from 1 to 3, 4 to 7, and 8 to 10, was 2.91 months, 7.00 months, and 31.38 months respectively ( p = 0.0001). Using the Cox model, extracranial disease status and KPS demonstrated significant correlation with prognosis ( p = 0.0001 and 0.0004 respectively). Multivariate analysis also demonstrated significance for SIR and RPA when tested individually ( p = 0.0001 and 0.0040 respectively). Applying the Cox Model to both SIR and RPA, only SIR reached independent significance ( p = 0.0004). Conclusions: Systemic disease status, KPS, SIR, and RPA are reliable prognostic factors for patients with brain metastases submitted to radiosurgery. Applying SIR and RPA classifications to our patients' data, SIR demonstrated better accuracy in predicting prognosis. SIR should be further tested with larger patient accrual and for all patients with brain metastases subjected or not to stereotactic radiosurgery.

Time series analysis of air pollution and mortality: effects by cause, age and socioeconomic status

Abstract: OBJECTIVE—To investigate the association between outdoor air pollution and mortality in Sao Paulo, Brazil. DESIGN—Time series study METHODS—All causes, respiratory and cardiovascular mortality were analysed and the role of age and socioeconomic status in modifying associations between mortality and air pollution were investigated. Models used Poisson regression and included terms for temporal patterns, meteorology, and autocorrelation. MAIN RESULTS—All causes all ages mortality showed much smaller associations with air pollution than mortality for specific causes and age groups. In the elderly, a 3-4% increase in daily deaths for all causes and for cardiovascular diseases was associated with an increase in fine particulate matter and in sulphur dioxide from the 10th to the 90th percentile. For respiratory deaths the increase in mortality was higher (6%). Cardiovascular deaths were additionally associated with levels of carbon monoxide (4% increase in daily deaths). The associations between air pollutants and mortality in children under 5 years of age were not statistically significant. There was a significant trend of increasing risk of death according to age with effects most evident for subjects over 65 years old. The effect of air pollution was also larger in areas of higher socioeconomic level. CONCLUSIONS—These results show further evidence of an association between air pollution and mortality but of smaller magnitude than found in other similar studies. In addition, it seems that older age groups are at a higher risk of mortality associated with air pollution. Such complexity should be taken into account in health risk assessment based on time series studies. Keywords: air pollution; mortality; socioeconomic status

Synergy in a Neural Code

Abstract: We show that the information carried by compound events in neural spike trains—patterns of spikes across time or across a population of cells— can be measured, independent of assumptions about what these patterns might represent. By comparing the information carried by a compound pattern with the information carried independently by its parts, we directly measure the synergy among these parts. We illustrate the use of these methods by applying them to experiments on the motion-sensitive neuron H1 of the fly’s visual system, where we confirm that two spikes close together in time carry far more than twice the information carried by a single spike. We analyze the sources of this synergy and provide evidence that pairs of spikes close together in time may be especially important patterns in the code of H1.

Standard transition aluminas. Electron microscopy studies

Abstract: The aim of this paper is to present the results of characterization of the particle shapes of six standard transition aluminas samples using transmission and scanning electron microscopies; selected area electron diffraction, in parallel with X-ray powder diffraction were used for confirmation of the different transition aluminas types. The transition aluminas - chi; kappa; gamma; theta; delta; and eta were supplied by ALCOA Central Laboratory. The chi-; kappa-;gamma- and delta-Al203 microcrystals are pseudomorphs from their respective precursors gibbsite and boehmite. However, theta-Al203 microcrystals are not pseudomorphs after the standard delta-Al203 sample. Also, eta-Al203 are not pseudomorphs after bayerite somatoids.

The two largest chloroplast genome-encoded open reading frames of higher plants are essential genes

Abstract: The chloroplast genomes of most higher plants contain two giant open reading frames designated ycf1 and ycf2. In tobacco, ycf1 potentially specifies a protein of 1901 amino acids. The putative gene product of the ycf2 reading frame is a protein of 2280 amino acids. In an attempt to determine the functions of ycf1 and ycf2, we have constructed several mutant alleles for targeted disruption and/or deletion of these two reading frames. The mutant alleles were introduced into the tobacco plastid genome by biolistic chloroplast transformation to replace the corresponding wild-type alleles by homologous recombination. Chloroplast transformants were obtained for all constructs and tested for their homoplastomic state. We report here that all transformed lines remained heteroplastomic even after repeated cycles of regeneration under high selective pressure. A balanced selection was observed in the presence of the antibiotic spectinomycin, resulting in maintenance of a fairly constant ratio of wild-type versus transformed genome copies. Upon removal of the antibiotic and therewith release of the selective pressure, sorting out towards the wild-type plastid genome occurred in all transplastomic lines. These findings suggest that ycf1 and ycf2 are functional genes and encode products that are essential for cell survival. The two reading frames are thus the first higher plant chloroplast genes identified as being indispensable.

Mudanças na composição e adequação nutricional da dieta familiar nas áreas metropolitanas do Brasil (1988-1996)

Abstract: OBJETIVO: Atualizar a tendencia secular (1962-1988) da composicao e da adequacao nutricional da dieta familiar praticada nas areas metropolitanas do Brasil, com base em nova pesquisa sobre orcamentos familiares realizada em meados da decada de 90. METODOS: Utilizaram-se como fontes de dados as pesquisas sobre orcamentos familiares (POF) da Fundacao IBGE, realizadas entre marco de 1987 e fevereiro de 1988 (13.611 domicilios) e entre outubro de 1995 e setembro de 1996 (16.014 domicilios), tendo ambas como universo de estudo as areas metropolitanas do Brasil. Nas duas pesquisas chegou-se a disponibilidade domiciliar diaria per capita de alimentos, dividindo-se o total de alimentos adquiridos no mes pelo numero de pessoas residentes no domicilio e pelo numero de dias do mes. O padrao alimentar foi caracterizado com base na participacao relativa de grupos selecionados de alimentos e de nutrientes na disponibilidade calorica total. A comparacao entre as duas pesquisas levou em conta o conjunto das areas metropolitanas do Pais e estratos dessas areas correspondentes as regioes menos desenvolvidas (Norte e Nordeste) e mais desenvolvidas (Centro-Oeste, Sudeste e Sul). RESULTADOS: Observou-se intensificacao do consumo relativo de carnes, de leites e de seus derivados (exceto manteiga) em todas as areas metropolitanas, enquanto o consumo de ovos passou a declinar, sobretudo no Centro-Sul do Pais. Leguminosas, raizes e tuberculos prosseguiram sua trajetoria descendente, mas cereais e derivados tenderam a se estabilizar no Centro-Sul ou mesmo a se elevar ligeiramente no Norte-Nordeste. A participacao relativa de acucar refinado e refrigerantes cresceu em todas as areas, sendo que a participacao de oleos e gorduras vegetais manteve-se constante no Norte-Nordeste e declinou intensamente no Centro-Sul. CONCLUSOES: A tendencia ascendente da participacao relativa de lipidios na dieta do Norte e do Nordeste, o aumento no consumo de acidos graxos saturados em todas as areas metropolitanas do Pais, ao lado da reducao do consumo de carboidratos completos, da estagnacao ou da reducao do consumo de leguminosas, verduras, legumes e frutas e do aumento no consumo ja excessivo de acucar sao os tracos marcantes e negativos da evolucao do padrao alimentar entre 1988 e 1996. Mudancas que podem indicar a adesao da populacao a dietas mais saudaveis -- declinio no consumo de ovos e recuo discreto da elevada proporcao de calorias lipidicas -- foram registradas apenas no Centro-Sul do Pais.