Extreme South Of Brazil Research Articles

Protein enrichment and digestibility of soft rush (Juncus effusus) and rice residues using edible mushrooms Pleurotus ostreatus and Pleurotus sajor-caju

Pleurotus species are found to be among the most efficient lignocellulolytic types of white-rot fungi. Rice is the main grain cultivated in the extreme south of Brazil. Defatted rice bran and straw are by-products of low aggregate value. Soft rush (Juncus effusus) is a common native plant also very abundant in the region. In the present work, we evaluated changes in substrate composition after growth of two white-rot fungal species: Pleurotus ostreatus and Pleurotus sajor-caju, aiming to increase protein content and digestibility from substrates through solid fermentations and obtain edible mushrooms of high aggregate value. For that, defatted rice bran, defatted rice straw and soft rush were utilized as substrate. The influence of the variables thermal treatment temperature of substrate, substrate moisture and concentration were evaluated on the protein content, digestibility and biological efficiency. The highest protein enrichment of rice bran in P. sajor-caju-fermented medium was due the fact that there was no fructification in these media, while for the P. ostreatus-fermented medium, part of the synthesized protein was converted into mushrooms. The highest protein enrichments were verified in medium with 80% moisture and 25% soft rush (47.1% using P. ostreatus and 49.0% using P. sajor-caju). A higher digestible protein increase was obtained for both species in media with 70% moisture and 25% soft rush.

Frog diversity in the Floresta Nacional de Chapecó, Atlantic Forest of southern Brazil

The Atlantic Forest is considered one of the world's biological diversity hotspots but is nevertheless increasingly threatened with the rapid destruction and fragmentation of its natural areas. In the state of Santa Catarina, southern Brazil, remnants of the mixed ombrophilous forest and seasonal deciduous forest exist as islands within large areas of agriculture, pastures and human settlements. Here we present information on species richness and habitat use by anurans in the Floresta Nacional de Chapecó, located in the western portion of the state of Santa Catarina. Anurans were surveyed by active search of potential reproductive sites from December 1998 to December 2001. A total of 29 species were recorded, most of which have a known distribution restricted to southern Brazil and adjacent countries (Argentina, Paraguay, and Uruguay) and use open areas for reproduction. The species composition was most similar to other areas of mixed ombrophilous forest and seasonal deciduous forest from the extreme south of Brazil. The information in this study may support the implementation of conservation and management strategies in the area.

Outdoor and Indoor Cultivation of Spirulina platensis in the Extreme South of Brazil

Water supplemented with 10% or 20% (v/v) of Zarrouk medium was used to cultivate Spirulina platensis in closed and open bioreactors under controlled conditions (30 degrees C, 32.5 micromol m(-2) s(-1), 12 h light/dark photoperiod) and in a greenhouse (9.4 to 46 degrees C, up to 2800 micromol m(-2) s(-1), variable day length photoperiod) using different initial biomass concentrations (X0) in the extreme south of Brazil (32.05 degrees S, 52.11 degrees W). Under controlled conditions the maximum specific growth rate (micromax) was 0.102 d(-1), the biomass doubling time (t(d)) was 6.8 d, the maximum dry biomass concentration (Xmax) was 1.94 g L(-1) and the maximum productivity (Pmax) was 0.059 g L(-)1 d(-1), while the corresponding values in the greenhouse experiments were micromax = 0.322 d(-1), t(d) = 2.2 d, Xmax = 1.73 g L(-1) and Pmax = 0.112 g L(-1) d(-1). Under controlled conditions the highest values for these parameters occurred when X0 = 0.15 g L(-1), while in the greenhouse X0 = 0.4 g L(-1) produced the highest values. These results show that the cultivation of S. platensis in greenhouses in the extreme south of Brazil is technically viable and that the S. platensis inoculum and the concentration of Zarrouk medium can be combined in such a way as to obtain growth and productivity parameters comparable, or superior, to those occurring in bioreactors under controlled conditions of temperature, illuminance and photoperiod.

Variabilidade Temporal em Longo Período da Descarga Fluvial e Níveis de Água da Lagoa dos Patos, Rio Grande do Sul, Brasil

The influence of river discharge in the marine environment is expressed in several time scales, but in long time scales it tends to control the residual pattern of behavior of these ecosystems. Studies on the dynamics of the Patos Lagoon, located in the extreme south of Brazil, are limited to considering the effect of wind and river discharge on synoptic time scales. In this sense, the objective of the study is to investigate the time variability scale of the dominant processes over the long term in river discharge and water levels in Patos Lagoon. Several time series of river discharge, water levels and Southern Oscillation Index were used to perform the study. A polynomial model based on the least squares method was used to re-construct series of water levels and statistical analysis methods were used to determine the main cycles of variability and their possible cause and effect relationship in the variables analyzed. The time series analysis suggests that on a scale of years, the river discharge accounts for over 80% of the variability in the lagoonal portion of Patos Lagoon. The river discharge in the main tributaries and the water levels in Patos lagoon are influenced on interannual scales (cycles between 3.3 and 5 years) by El Nino Southern Oscillation. The river discharge and the water levels in the region also follow a pattern of temporal variability with a decadal scale (10.8 year cycle)., which may have been associated with El Nino Southern Oscillation events, or with other oceanic and atmospheric processes of climatic kind on global scales

Diversity and natural hybridization in a highly endemic species of Petunia (Solanaceae): a molecular and ecological analysis

Intrinsic reproductive barriers among the species of Petunia are weak and genetic isolation is obtained mainly by geographical separation and ecological diversification. The Serra do Sudeste region in the extreme south of Brazil is one of the centres of diversity of this genus and is characterized by the presence of species with different pollination syndromes. Petunia exserta is known only from four sandstone towers in a restricted area of this region (about 500 km(2)) and is characterized by its differentiated habitat (shelters in the sandstone towers) and by its floral characteristics adapted to ornithophily. In towers where this species is sympatric with the sphingophilous Petunia axillaris, phylogenetically close to P. exserta, we found plants with intermediate floral morphology, suggesting hybridization between them. To test this hypothesis and to better understand its consequences we analysed the sequences of the plastid trnH-psbA, trnS-trnG and psbB-psbH intergenic spacers in 121 individuals sampled all over the P. exserta distribution. The joint analysis of the three markers revealed 13 haplotypes and the network showed two main genetic clades, which probably represent the original gene pool of the two species in the region. In general, individuals of a given population presented the same haplotype, independently of phenotype, corroborating the hybridization hypothesis. Field observations suggest that hummingbirds are responsible for the interspecific gene flow. Analysis of molecular variance revealed high interpopulational diversity among the towers. The low gene flow between populations is possibly related to the autochoric seed dispersion system.

Tuberculosis: a study of 111 cases in an area of high prevalence in the extreme south of Brazil

Tuberculosis is an increasingly important public health problem in developing countries. We studied 111 tuberculosis patients confirmed by mycobacteria isolation between 1998 and 2000 in Rio Grande, in south Brazil. One-hundred-thirteen pulmonary and extrapulmonary clinical materials were examined through culture by the Ogawa-Kudoh method and through smear examination by the Ziehl-Nielsen or Kinyoun methods. The identification of Mycobacterium tuberculosis was done through the usual phenotypical methods. The proportion method (indirect technique) was used to determine the resistance of isolates. The man/woman ratio was 2.6:1, 75% were white, and the group had a mean age of 39.7+/-12.7. Risk factors were present in 38.7% (34 men and 9 women, p=0.2), with a mean age of 35 (p=0.002); infection by HIV was the most frequent (28.8%), followed by alcoholism (16.2%) and injected drug use (15.3%). The frequency of M. tuberculosis isolates was 99.1%. Pulmonary disease occurred in 88.3% of the cases, extrapulmonary in 9.9% and 1.8% in both. There was an association between extrapulmonary tuberculosis and the presence of risk factors (p=0.0001). Resistance to isoniazid was found in 4% of the isolates and to isoniazid and rifampin in 2%, all being patients with some risk factors. The profile of tuberculosis in the population of this study followed the pattern described for developing regions of the world.

Simultaneous Cultivation of Spirulina platensis and the Toxigenic Cyanobacteria Microcystis aeruginosa

Mangueira Lagoon, located in the extreme south of Brazil, has water with physicochemical characteristics such as alkaline pH and carbonate levels propitious for the growth of the cyanobacterium Spirulina platensis. Previously published studies have shown that Mangueira Lagoon water supplemented with small quantities of carbon and nitrogen is suitable for S. platensis cultivation and can significantly reduce production costs. We studied mixed cultures of Spirulina platensis and the toxic cyanobacterium Microcystis aeruginosa using a 2(3) factorial design in which the three factors were the initial biomass concentration of S. platensis and M. aeruginosa and the type of culture medium (100% Zarrouk's medium or 80% Mangueira Lagoon water plus 20% Zarrouk's medium). The highest S. platensis maximum specific growth rate (mu(max)) occurred in the culture with the highest M. aeruginosa biomass concentration and when undiluted culture medium was used (micro(max) = 0.283 d(-1)). The highest M. aeruginosa specific death rate (k) was obtained in the presence of S. platensis (k = 0.555 d(-1)) and was independent of the initial M. aeruginosa biomass concentration and culture medium, demonstrating that S. platensis cultures are not susceptible to contamination by M. aeruginosa. The culture medium had no significant influence (p > 0.05) on S. platensis micro(max) values, indicating that production costs could be reduced by using a medium consisting of 80% Mangueira Lagoon water plus 20% Zarrouk's medium.

Cohort Profile: The 1982 Pelotas (Brazil) Birth Cohort Study

Pelotas is a city in the extreme south of Brazil, near the border of Uruguay, with 214 000 urban inhabitants in 1982. At the time, we were assistant professors, each working in one of the two medical schools in the city, and both undergoing post-graduate training at the University of London. We were inspired by the findings of the British perinatal study, and one of us (FCB) decided to do a similar study for his doctoral thesis. The lack of reliable data on perinatal mortality in Brazil, due to poor registration of births and deaths—particularly stillbirths— justified the launch of the study. Funding from the International Development Research Center (Canada) was obtained for the perinatal survey, which led to FCB’s PhD thesis. 1,2

O desenho infantil na ótica da ecologia do desenvolvimento humano

Este trabalho resultou de reflexões sobre a Abordagem Ecológica do Desenvolvimento Humano de Urie Bronfenbrenner associada ao pensamento de estudiosos da Educação Ambiental. O foco deste artigo será compreender a relação entre percepção, o desenho e o conceito de atividade molar na perspectiva ecológica de Bronfenbrenner. Pressupõe-se que o desenho é também uma forma de expressar criativamente a percepção que as crianças têm dos ambientes que habitam. Será ressaltada a importância da imaginação e potencial da expressão do desenho como importante ferramenta na construção de conhecimentos e integração de experiências originadas em contextos variados. Estas experiências gráficas fazem parte do crescimento psicológico e são essenciais para a formação de indivíduos sensíveis, criativos e capazes de transcender e transformar a realidade. Para trabalhar com estas idéias são exemplificados desenhos de crianças de uma ONG no Extremo Sul do Brasil que propõe educação ambiental através de arte-educação.

Periodicity of atmospheric phenomena occurring in the extreme South of Brazil

Spectral analysis revealed oscillations associated to atmospheric phenomena in the extreme south of Brazil. Cycles from 36 to 77 days, linked to Madden–Julian Oscillation, from 18 to 28 days, related to the bipolar South Atlantic Convergence Zone-Subtropics mode and 10-day oscillations due to the passage of frontal systems were detected.

Fenologia de uma comunidade de duna frontal no sul do Brasil

Este estudo visou descrever os padrões fenológicos em uma comunidade de dunas costeiras em Santa Catarina (27ºS), avaliar suas relações a fatores climáticos e comparar estes padrões aos de comunidades situadas em outras latitudes na costa brasileira. O estudo foi realizado com espécies da duna frontal da Praia da Joaquina, Ilha de Santa Catarina, SC. Empregou-se um método com base em freqüência, calculando-se mensalmente a ocorrência das espécies e de suas fenofases (n=73 quadrados fixos de 1x1m). Ocorreram espécies florescendo e frutificando ao longo de todo o ano. como observado nas comunidades situadas a menores latitudes (SP: 24ºS e ES: 20ºS). O maior número de espécies em floração e frutificação ocorreu no período quente e super-úmido. De forma distinta ao que ocorre no extremo sul do Brasil (RS: 32ºS), observaram-se várias espécies em floração nos meses mais frios de inverno. Muitas destas, entretanto, com floração longa, mostraram redução em suas amplitudes de floração neste período. Isto pode sugerir certa limitação por temperaturas mais baixas e/ou refletir o déficit hídrico ocorrido neste período. Das 34 espécies monitoradas, 15 mostraram episódios de germinação, sendo estes mais freqüentes em meses de outono/inverno, com temperatura e umidade em declínio. A germinação no outono/inverno é discutida como estratégia utilizada pelas espécies de duna como forma de escapar das condições de maior temperatura e evapotranspiração no verão. Processos de rebrota foram registrados para 17 espécies, sendo também mais freqüentes no período do outono/inverno. Restrições de umidade com ocorrência de déficit hídrico afetam tanto os eventos de floração e frutificação, como os de germinação e brotamento.

CORRELAÇÃO DO MAGMATISMO DAS BACIAS DA MARGEM CONTINENTAL BRASILEIRA COM O DAS ÁREAS EMERSAS ADJACENTES

The available information on the Cretaceous-Tertiary magmatism in Brazilian marginal basins is synthesized, aiming at a comparison with similar events that affected the emerged adjacent areas. The Eocretaceous pre-Aptian basaltic volcanism is more common in the basins from Espirito Santo to the Sduth, where it can be correlated with dikes and lava flows of the Serra Geral Formation. It is also present in Northeast Brazil, at the southern part of the submerged Potiguar Basin. At the extreme south of Brazil, the presence of acid magmatism in the Parana Basin allows one to suppose the existence of similar compositions in the poorly known Pelotas Basin. The quiescence of magmatism during Aptian-Albian time is a common characteristic of almost all Brazilian marginal basins, as well as in the emerged continental area, but rocks belonging to this age are present in the Ceara Basin and in the Cabo area (PE). Neocretaceous-Eocene magmatism of alkaline trend is present in the emerged region of the Cabo Frio Magmatic Lineament. Possibly it can be extended to the submerged margin. Eocene volcanism is very important at the Cabo Frio Platform and south of Campos Basin. The islands situated along the Santos BasirTs margin are composed by feldspathoid-bearing alkaline rocks, the emplacement of which is related to the Rio de Janeiro Lineament. The Tertiary volcanism in Northeast Brazil lasted until Miocene, in the Potiguar Basin and emerged region, but in South-Southeast Brazil it seems to have ceased after Eocene. The Fernando de Noronha Fracture Zone extended up to the coast, allowing the onset of Oligocene alkaline volcanism. The Remanche Fracture Zone extends up to the Ceara Basin and the Sao Luis Craton, and controls the acid magmatism observed in the Atlântico and Ceara highs. The Vitoria-Trindade Fracture Zone also seems to extend to the continent, as suggested by the structures and basic dikes of the Fundao Suite. The basins situated between the Ceara State and the Marajo Island are amagmatic, as well as the Reconcavo Basin, in part because they have been installed on rigid crust of Sao Luis and Sao Francisco cratons. It is suggested that the faster continent withdrawal in the South as compared to the Northeast Brazil associated to different rift processes could have been the cause for cessation of volcanism only after the Miocene in the last region.

Experimental results from measurements performed during the 12 November 1966 total solar eclipse with a 4.28-cm radio polarimeter

Radio observations of the Sun with a 4.28-cm radio polarimeter were performed during the 12 November 1966 total solar eclipse at a site located near the city of Bagé, in the extreme south of Brazil. The solar activity during that period is discussed, giving additional data for the eclipse measurements themselves. The difference between radio and optical contacts indicated that there is a significant radio emission at a height near 0.12 solar radii over the photosphere, and the basic residual flux due to the contribution of the ring during the totality was found to be 12.2% of the total flux. An important “radio spot” was present near the center of the solar disk, contributing almost alone to the observed basic left-handed circularly polarized component of solar radiation. During totality no important residual polarization was found and if it still existed it is neglectable.