Stream type diversity in the Atlantic lowland of the Jureia area (Subtropical Brazil)

Different combinations of the three basic streaming water types in the Jureia area (São Paulo), namely blackwater with low pH, clearwater with low pH and estuarine water, are described. The hydrological situation is compared to that of the Amazonian basin and some paleolimnological and potamological observations are added.Scientific Contribution No. 6 from the Jureia Ecological Station (São Paulo, Brasil).Scientific Contribution No. 6 from the Jureia Ecological Station (São Paulo, Brasil).     

Determination of the enzymatic activity of pectinases from different microorganisms

The decrease in viscosity is widely used to estimate the activity of pectinolytic enzymes. This method is shown to be influenced by the production strain and this prevents an accurate comparison between the activities of different microorganisms, especially under different conditions.A.E. Maiorano and Y. Ogaki are with the Divisão de Quimica, with the Agrupamento de Biotecnologia, Instituto de Pesquisas Tecnológicas do Estado de São Paulo S/A.-IPT, Cidade Universitária, Caixa Postal 7141, CEP 01064-970, São Paulo, SP, Brazil; W. Schmidell is with the Departamento de Engenharia Quimica, Escola Politécnia, Universidade de São Paulo, Caixa Postal 61548, CEP 05424-970, São Paulo, SP, Brazil.     

Quantification of trehalose in biological samples with a conidial trehalase from the thermophilic fungus Humicola grisea var. thermoidea

The partially-purified, thermally-stable trehalase from conidia of Humicola grisea was highly specific for trehalose and was free of potentially interfering activities. The enzyme was fully stable when stored in solution at -15°C for at least 6 months. This preparation could be used to quantify trehalose from 0.05 to 1.25 mol/ml either in carbohydrate mixtures or in complex biological materials.M.J. Neves, H.F. Terenzi and J.A. Jorge are with Departmento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirao Preto, Universidade de São Paulo, 14040-901-Ribeirão Preto, São Paulo, Brazil; F.A. Leone is with Departamento de Quimica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901-Ribeirão Preto, São Paulo, Brazil.     

Floristic comparison of mesophytic semideciduous forests of the interior of the state of São Paulo,Southeast Brazil

The floristic composition (trees) of 26 forests in the state of São Paulo, Brazil, was compared using cluster analysis and Principal Coordinates Analysis (PCO) with simple Euclidean distance. The results obtained indicate the existence of two floristically distinct groups of forests. One group contains forests from higher areas (above 700 m) with a colder climate (Cfa and Cfb) and includes surveys from Angatuba, Atibaia, Guarulhos, Jundiaí, São José dos Compos and São Paulo. The second group is floristically less homogeneous and includes forests of the central and western parts of the state, usually at lower altitudes (500–700 m) and subject to hotter climatic conditions (Cwa).     

Improved culture media for growth of Bradyrhizobium japonicum

A freshly-prepared yeast extract at 30 or 50 g/l improved the growth of Bradyrhizobium japonicum SEMIA 587 in a 5-l stirred fermenter. Monosodium glutamate or a commercial yeast extract at 2.0 g/l almost doubled cell mass productivity and cell viability when added at the end of the first exponential growth phase.The authors are with the Divisão de Quimica, Agrupamento de Biotecnologia, Instituto de Pesquisas Tecnológicas do Estado de São Paulo, S/A.-IPT-Cidade Universitária s/n., Caixa Postal 7141, CEP 01064-970, São Paulo, SP, Brazil     

Disseminated dermatophytosis caused by Microsporum gypseum in two patients with the acquired immunodeficiency syndrome

Microsporum gypseum is not a common agent of human dermatophytosis. To the best of our knowledge, this fungus has not been described in human immunodeficiency virus (HIV)-infected patients. We report a tinea corporis infection with atypical presentation caused by M. gypseum in two patients with the acquired immunodeficiency syndrome (AIDS) studied at the São Paulo Hospital (São Paulo, Brazil).This revised version was published online in October 2005 with corrections to the Cover Date.     

Reproductive isolation in the saltans group of Drosophila. I. The saltans subgroup

In order to study isolation within the salians subgroup, pair mating crosses involving its 7 species were performed. The results of testing different interspecific combinations varied from complete isolation at the insemination level to the production of fertile hybrids. Some isolation indices are proposed: Ii (isolation index at the insemination level), Fi (isolation index at the fertilization level), Ti (total isolation index), and Ai (average isolation index). A schema of the biological relationships on the basis of the isolation degree is also presented for the 7 species of the subgroup.Part of this study was included in the thesis submitted for the PH.D. degree at the University of São Paulo and was performed during the tenure of a fellowship supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo.     

Histoplasmosis in individuals with acquired immunodeficiency syndrome (AIDS): Report of six cases with cutaneous-mucosal involvement

The authors report the first six cases of disseminated histoplasmosis and acquired immunodeficiency syndrome (AIDS) seen at the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo, from 1987 to 1989, with emphasis on dermatological clinical manifestations, nasal mucosa lesions and treatment. The mycosis was the first manifestation of AIDS in four patients. It is concluded that biopsies of the lesions for histopathologic study and fungal culture are important for diagnosis.     

Predation on and by pelagic Turbellaria in some lakes in Brazil

Planktonic Turbellaria are of common occurrence in both natural and man-made lakes in Brazil. Experiments were performed in 1987 and 1989 to determine which zooplankton species are consumed by predatory Mesostoma sp. from three natural lakes in the Rio Doce Valley. Experiments were also performed in 1989 with a yet unidentified flatworm from Barra Bonita reservoir. Both predators consumed Daphnia and Ceriodaphnia at a high rate: 4 individuals per day in the case of Mesostoma sp., a large species and 1.5 ind day^–1 in the case of the smaller species from Barra Bonita reservoir. Consumption of copepod nauplii, copepodids and adults was much lower, and Ostracoda were not consumed at all. Experiments on food selectivity showed a clear preference by the flatworms for cladocerans.In the lakes studied, flatworms are heavily preyed upon by larvae of Chaoborus and by Mesocyclops species.Turbellaria densities in the natural lakes were around 300 individuals per cubic meter, whereas in Barra Bonita reservoir, 1000 individuals per cubic meter was a mean value in a fifteen days study.Federal University of São Carlos - Laboratory of LimnologyUniversity of São Paulo - Canter of Water Resource and Applied EcologyPost-graduate student - University of São Paulo     

A Late carboniferous palynoflora from the Itararé Subgroup (Paraná Basin) in Campinas, São Paulo State, Brazil

Upper Paleozoic sedimentary sequences from several localities of the northeastern Paraná Basin were sampled for paleobotanical and palynological studies. Well-preserved terrestrial assemblages from samples of Campinas, São Paulo State, from an outcrop at the 97 km mark on the Bandeirantes Highway, located at the Municipality of Campinas, São Paulo State were recorded where fertile bryophytes and megaspores were previously also found. The Campinas palynoflora is composed of 23 species of bryophytic and pteridophytic spores, 16 species of pollen grains, and one algae (Botryococcus braunii Kützing). Among the sporomorphs, Reticulatisporites asperidictyus Playford and Helby is described for the first time from the Paraná Basin. Assemblages bear diagnostic species of the Ahrensisporites cristatus Interval Zone, such as Anapiculatisporites argentinensis Azcuy, Cristatisporites inordinatus (Menéndez and Azcuy) Playford, and Psomospora detecta Playford and Helby, of Late Carboniferous age (Pennsylvanian). Palynological content suggests a glacio-deltaic/lacustrine environment of deposition. This is supported by lithological data and by the absence of marine palynomorphs.     

Predation on Ceriodaphnia cornuta and Brachionus calyciflorus by two Mesocyclops species coexisting in Barra Bonita reservoir (SP,Brazil)

Feeding experiments with two species of carnivorous copepod, Mesocyclops longisetus (Thiebaud) and Mesocyclops kieferi Van de Velde from Barra Bonita, a eutrophic reservoir in São Paulo, Brasil, were performed using two common types of prey: Ceriodaphnia cornuta, a cladoceran, with a mean body length of 464 µm (including spines) or 393 µm (without spines), and Brachionus calyciflorus, a rotifer with a mean body length of 350 µm (including spines) or 279 µm (without spines).Both species showed higher consumption rates on Brachionus than on Ceriodaphnia. For Mesocyclops longisetus, the average rates were: 2.19 prey ind^–1 h^–1 (Brachionus), and 1.30 prey ind^–1 h^–1 (Ceriodaphnia). For Mesocyclops kieferi, the rates were 1.85 prey ind^–1 h^–1 (Brachionus) and 0.60 prey ind^–1 h^–1 (Ceriodaphnia). These experimental data are discussed with reference to the dynamics of the predator and prey populations in the reservoir.Laboratorio de Limnologia, Departamento de Ciencias Biologicas, Universidade Federal de São CarlosCentro de Recursos Hidricos e Ecologia Aplicada Lab. de Limnologia, Departamento de Hidraulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo     

Humic substance mineralization in a tropical oxbow lake (São Paulo,Brazil)

We evaluated the mineralization rates of humic substances in Infernão oxbow lake (State of São Paulo, Brazil). Experiments were conducted under aerobic and anaerobic conditions using fulvic acid and humic acid from four sources: Scirpus cubensis and Cabomba piauhyensis leachate submitted to a 120-day degradation process, sediment, and dissolved organic matter from the lake water. A fixed amount of substrate was added to 450 ml of water from Infernão lake, filtered over glass wool. After adding substrate, the flasks were incubated at 21.0°C under aerobic and anaerobic conditions. The dissolved organic carbon was monitored during 95 days. The results were fitted to first-order kinetics model, which pointed to one labile and one refractory fraction. The refractory fractions predominated, ranging from 71.4 to 84.3% for fulvic acid and from 73.4 to 85.0% for humic acid. Mineralization rates of the labile fractions of dissolved organic carbon were higher under aerobic than anaerobic conditions, while the converse was true for the refractory fractions.     

Effects of genotoxic agents on his + revertants and survival of spores of Streptomyces aureofaciens

The effects of u.v. light and of several chemical agents on spores of the tetracycline producer Streptomyces aureofaciens MT1 were studied using survival curves and induction of histidine prototrophic revertants (his ⁺). Spores were highly resistant to u.v.; NTG induced most his ⁺ revertants. 4-Nitroquinoline-1-oxide and methyl methanesulphonate also gave good yields of revertants. Whereas ethyl methanesulphonate had the least effect on inducing the revertants.M. Marins is with the Department of Biochemistry, Institute of Chemistry, University of São Paulo, SP, Brazil. S.O.P. Costa and G. Padilla are with the Department of Microbiology, Biomedical Science Institute, University of São Paulo, Avenida Prof. Lineu Prestes 1374, SP, Brazil, CEP 05508-900     

Paternal or maternal origin of human i(Xq) isochromosomes

Summary We present a method to test if the proportion of 45,X cases resulting from loss of the maternal chromosome or of cases of 46,X,i(Xq) with the isochromosome of maternal origin is different from 1/2. The available data are consistent with the hypothesis that the normal X present in i(Xq) patients originates with equal probabilities in the fathers and mothers of the patientsThis paper was supported in part by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)     

Pectinase production by Penicillium frequentans

High activities of extracellular pectinase with viscosity-diminishing and reducing groups-releasing activities were produced by Penicillium frequentans after 48 h at 35°C, in agitated cultures supplemented with 0.5% citrus pectin and initial pH of 2.5. Under these conditions the fungus also produced high activity of pectinesterase. At an initial pH of 7.0 or 8.0, pectin lyase activity was also detected. Enzyme activity releasing reducing sugars was more stable at 50°C than viscosity-diminishing activity. Both activities were maximal at pH 2.5 to 5.2 and at 55°C.The authors are from the Faculdade de Ciências Farmacêuticas de Ribeirão Preto da Universidade de São Paulo, Avenida do Café, s/n^o, Bairro Monte Alegre, 14.049 Ribeirão Preto, S.P., Brazil.     

Sensitivity facilitation in the insect eye

Summary ERG amplitude facilitation, observed in the eye ofAtta sexdens after light adaptation, was studied as a function of duration and intensity of adaptation, of dark interval between adapting and test stimuli, and of level of steady background illumination. Results show that sensitivity facilitation in this eye cannot be regarded as a minor effect since it covers a 2 log unit range, the same as that obtained for conditions that produce sensitivity reduction. Maximum facilitation occurs with short and intense light adaptation. The time span of the effect is close to 2 min, and its maximum amplitude may be attained up to 20 s after light adaptation. Increase in background illumination gradually erases facilitation. However, the facilitated response is less sensitive to background illumination than the dark adapted response. Long durations of light adaptation cause ERG decrease, or inhibition. A comparison of these two end results of light adaptation suggests that they arise from different processes, perhaps with distinct origins.Supported by a grant from Fundação de Amparo à Pesquisa do Estado de São Paulo, to the senior author (Contract n 71/1141)With a Fellowship from Fundação de Amparo à Pesquisa do Estado de São Paulo (N 74/388)We wish to express our appreciation to Henrique Fix for his editorial assistance, and to Celia Jablonka for laboratory help.     

Discrete, subsurface layers of the autotrophic ciliate Mesodinium rubrum off Brazil

Highly constrained, subsurface layers of Mesodinium rubrum (Lohmann)were observed and sampled on the continental shelf off the northerncoast of São Paulo State, Brazil in calm, sunny weather.The layers of this autotrophic ciliate occurred as visible lenticularbillows of red water lying 1.5—2 m below the sea surface.Upper and lower limits of the discolored layers, as seen bydivers, were defined by sharp visual discontinuities. Maximumvertical thickness of the layers was     

Analytical solution of the evolution dynamics on a multiplicative-fitness landscape

In an infinite population the frequency distribution of individuals carrying a given number of mutations obeys a set of recursion equations, the equilibrium solution of which describes the mutation-selection balance. Although this solution is well-known in the case of a multiplicative-fitness landscape, where it is assumed that all mutations are deleterious and that each new mutation reduces the fitness of the individual by the same fraction, we are not aware of the existence of an analytical solution for the full dynamics. Using the generating function approach, we present here an explicit analytical solution for the frequency distribution recursion equations valid for all generations and initial conditions.This research was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Proj. No. 99/09644-9. The work of J.F.F. was supported in part by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).     

Plankton studies in a lacustrine environment

Summary Weekly zooplankton samples were taken during the period February, 1972 to January, 1973 at station III in a shallow and turbulent tropical reservoir (Broa Reservoir, São Carlos, São Paulo, State-Brazil). The samples were taken by plankton standard net with 68 mesh size, and collected through the horizontal hawls during 3 min. Rotifera was the most abundant group with 77.6%; Cladocera 13.6%, and Copepoda 8.7% (adult and naupliae stages). Other forms like Chaoborus larvae and some worms occurred sporadically. The seasonal fluctuation of the total zooplankton was very irregular in warm and rainy season and more stable in the dry and cold season. The composition of the zooplankton and its patterns of seasonal variation for eutrophic and oligotrophic aquatic ecosystems, in tropical regions, may differ significantly from temperate waters.     

Sequential production of pectinases byPenicillium frequentans

The pectinases produced byPenicillium frequentans were subjected to pectin- or sodium polypectate-PAGE. The fungus secreted one endo- and one exo-polygalacturonase during the first 10 h of incubation, either in media supplemented with pectin or in the absence of carbohydrate source. After 17 h of cultivation, another two exo-and three endo-polygalacturonases were detected in cultures supplemented with pectin. The results indicate that two constitutive polygalacturonases are secreted initially, followed by the synthesis of other inducible pectinases, in a sequential production of the pectinolytic complex. Monogalacturonic acid and sodium polypectate were better inducers for exo- than for endo-polygalacturonases, indicating that these enzymes are independently controlled.The authors are with the Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Avenida do Café s/n^o, 14040-903 Ribeirão Preto, São Paulo, Brazil