Showing papers by "University of São Paulo published in 1990"

Fire in the Ecology of the Brazilian Cerrado

Abstract: In the broad sense, the cerrado may be considered part of a large ecocline, occurring in Brazil under a single, tropical, seasonal climate (climate zone II of Walter 1970) and determined primarily by gradients of soil fertility and the incidence of fire. In fact, the cerrado represents the final portion of the transition from eutrophic tropical seasonal forest to a pedo- and peinobiome of tropical moist savanna and grassland (Fig. 1).

Variability of mangrove ecosystems along the brazilian coast

Abstract: Brazilian mangroves extend from 4°30′N to 28°30′S, varying greatly in growth form, species distribution patterns, and stand structure, in spite of a limited floristic diversity. We divided the Brazilian coastline into eight units, within which physiographic and climatic conditions are relatively uniform, and described mangrove occurrence, species distribution and structural attributes characteristic of each segment. In general, greates mangrove coverage and greatest forest stature are found in areas with a large surplus of rainfall over potential evapotranspiration and macrotidal regimes. An exception was the segment containing the mouth of the Amazon river, where freshwater systems dominate over brackish or marine associations. We believe that the variability in species associations and the dominance of each in a given environment is predominantly determined by the characteristics of the landforms that can be colonized by each species in a given region. The type, size, and frequency of occurrence of available landforms is a function of the particular mix of fluvial, tidal, and wave energies found in a region. Different species colonize these sites depending on their adaptations and edaphic preferences. Climate affects mangrove colonization and growth. We suggest that Brazilian mangroves play a minor role in modifying the geomorphic setting; the spatial arrangement of the various forest types is a response to the underlying topography and edaphic conditions, and to the constraints imposed by climatic and hydrologic factors. The spatial arrangement of species does not necessarily show successional processes, but may be the result of direct and differential colonization on appropriate substrates.

Antianxiety effect of cannabidiol in the elevated plus-maze

Abstract: In order to assess the presence of anxiolytic properties in cannabidiol (CBD) the drug was tested in an elevated plus-maze model of anxiety, in rats. Doses of 2.5, 5.0 and 10.0 mg/kg significantly increased the entry ratio (open/total number of entries), an anxiolytic-like effect. CBD at a dose of 20.0 mg/kg was no longer effective. None of the doses of CBD used changed total number of entries, a measure of total exploratory activity. Diazepam (2.0 mg/kg) also caused an anxiolytic-like effect in this model. These results indicate that CBD causes a selective anxiolytic effect in the elevated plus-maze, within a limited range of doses.

Haemophilia B: database of point mutations and short additions and deletions, 7th edition.

Abstract: The seventh edition of the haemophilia B database lists in easily accessible form all known factor IX mutations due to small changes (base substitutions and short additions and/or deletions of <30 bp) identified in haemophilia B patients. The 1535 patient entries are ordered by the nucleotide number of their mutation. Where known, details are given on: factor IX activity, factor IX antigen in circulation, presence of inhibitor and origin of mutation. References to published mutations are given and the laboratories generating the data are indicated.

Dynamic phase transition in the kinetic Ising model under a time-dependent oscillating field

Abstract: We analyze within a mean-field approach the stationary states of the kinetic Ising model described by the Glauber stochastic dynamics and subject to a time-dependent oscillating external field We have found that the magnetization of the system oscillates in time around a certain value that is zero at high temperatures or large field amplitudes and nonzero at low temperatures and small field amplitudes The transition from one regime to the other, which corresponds to a spontaneous symmetry breaking, is found to be continuous for sufficiently small values of the field amplitudes For higher values the transition becomes discontinuous and the system exhibits a dynamical tricritical point

Important bee plants for stingless bees (Melipona and Trigonini) and Africanized honeybees (Apis mellifera) in neotropical habitats: a review

Abstract: HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Important bee plants for stingless bees (Melipona and Trigonini) and Africanized honeybees (Apis mellifera) in neotropical habitats: a review M Ramalho, A Kleinert-Giovannini, Vl Imperatriz-Fonseca

Caste Development, Reproductive Strategies, and Control of Fertility in Honey Bees and Stingless Bees

Abstract: In the highly eusocial honey bees (Apinae) and stingless bees (Meliponinae) marked caste syndromes have evolved. The typical queen and worker characteristics are different from one another not just with regard to the reproductive organs but include many other morphological, physiological, and behavioral differences as well. These striking caste distinctions are the result of postembryonic divergences in development which depend on ecological conditions, mainly on the external factor of larval nutrition. Caste development in social insects in general belongs to the widespread phenomena of insect polymorphism and, in accordance with environmental control, castes in bees were called ecomorphs (de Wilde and Wirtz 1974; de Wilde 1975). The trophogenic basis for caste induction is provided by the nursing workers, although in a colony brood rearing including gyne production is strongly influenced by the queen. The queen also rigidly controls all reproduction of the workers. On the other hand, her own reproductive output depends completely on the helper functions of the workers, her daughters.

Mantle plumes and flood-basalt stratigraphy in the Paraná, South America

Abstract: Geochemical studies of the Parana continental flood basalts in Brazil have led to the recognition of distinct magma types, which have been used to infer the internal stratigraphy of the lava pile. The overstepping of stratigraphic units toward the north and a similar compositional change in sills within the underlying Parana basin sedimentary rocks imply that the site of magnatism migrated ∼750 km toward the north during this volcanic event. This has important implications for recent plume-related models that have argued whether fithospheric rifting must accompany the presence of a mantle plume in order to generate continental flood-basalt magmatism. It is difficult to ascribe the magnitude and direction of the shift in the locus of the Parana magmatism to movement of the Brazilian lithosphere relative to the underlying Tristan mantle plume. Instead, it is suggested that the observed lava distribution and internal structure of the Parana-Etendeka flood-basalt province were imposed by the intracacies of the rifting process during the initial opening of the South Atlantic Ocean.

Thomas-Fermi theory of δ-doped semiconductor structures: Exact analytical results in the high-density limit

Abstract: The nonlinear Thomas-Fermi formulation of \ensuremath{\delta} doping is proven to represent an exactly solvable model which is equivalent to the Hartree model in a wide range of doping densities. Analytical solutions to the eigenvalue problem of Schr\"odinger's equation in the Thomas-Fermi field are proven to exist and to represent the exact solutions to the many-body inhomogeneous electron system in the limit of high densities.

Periprosthetic fractures in patients with total knee arthroplasties.

Abstract: Ten patients with total knee arthroplasties sustained periprosthetic fractures. Nine of these were supracondylar fractures, and one occurred in the middle one-third of the tibia. These patients were treated with conservative methods in two cases and internal fixation with plate and screws in three cases. The remaining five patients were treated with intramedullary fixation using a specially designed revision prosthesis with long intramedullary stems. The best results wer achieved through the revision arthroplasty, based on walking ability, range of motion, and early rehabilitation.

Recombinant interleukin-1 and tumor necrosis factor induce neutrophil migration “in vivo” by indirect mechanisms

Abstract: The α and β forms of recombinant interleukin-1 (IL-1α and IL-1β) and of recombinant Tumor Necrosis Factor (TNFα and TNFβ) induced dose-dependent neutrophil migration into rat peritoneal cavities. Migration induced by both IL-1s showed a bell-shaped dose-response curve and IL-1β was 3-fold more potent than IL-1α. Pretreatment of the animals with dexamethasone or depletion of the peritoneal macrophage population, abolished the neutrophil migration induced by the four cytokines. “In vitro” stimulation of macrophage monolayers with IL-1β and the TNFs released a factor into the supernatant which, unlike these cytokines, induced neutrophil migration in dexamethasone pretreated animals. These results suggest that the neutrophil migration induced by IL-1α, IL-1β and TNFβ is not due to a direct effect on neutrophils, but occurs via the release of a chemotactic factors(s) from resident macrophages.

Padrões de distribuição geográfica dos gêneros de Eriocaulaceae

Abstract: Sao apresentados neste trabalho, os padroes de distribuicao geografica dos generos de Eriocaulaceae, com enfase nos generos americanos. A divisao generica da familia especialmente na regiao neotropical ainda nao e definitiva, porem existem alguns padroes de distribuicao que podem ser detectados. Os nove generos americanos, incluem-se em quatro padroes gerais de distribuicao: amplamente distribuidos nos tropicos; amplamente distribuido na Africa e America do Sul; limitado a America do Norte; limitado a America do Sul.

Myocardial revascularization without extracorporeal circulation. Seven-year experience in 593 cases.

Abstract: The authors present the results of 593 consecutive and non-selected patients who underwent direct myocardial revascularization without extracorporeal circulation in the period September 1981 to December 1988. The results are compared with 3086 patients who underwent conventional bypass surgery over the same period of time. The ages varied from 33 to 80 years (mean = 56) with 40 patients older than 70. The overall mortality in the group without cardiopulmonary bypass (CPB) was 1.7% (10/593) compared with 3.8% for conventional revascularization. Our mortality in the last 3 years has been 0.5% and 0% in the last 203 patients revascularized without CPB. The number of grafts varied from 1 to 5 (average 1.6). The treated arteries were: anterior descending (557), right (282) marginal (5) and circumflex marginal (4). Immediate postoperative complications were fewer and hospital discharge was earlier in the group treated without CPB. The authors conclude that this tactical alternative has the advantages of: lower morbidity and mortality, lower cost and no need for blood transfusion. Drawbacks are the need for greater technical expertise and it seems to be possible in about 19% of all patients who undergo myocardial revascularization.

Dip-coated TiO2CeO2 films as transparent counter-electrode for transmissive electrochromic devices☆

Abstract: The dip-coating process is an attractive way for the preparation of thin films used in the field of electrochromism. The scope of the present paper is focused on the TiO 2 CeO 2 compounds since they exhibit a reversible electrochemical insertion of lithium ions maintaining a high optical transmissivity. These films can be used as transparent counter-electrode in an all solid state electrochromic transmissive device with, for example, WO 3 as electrochromic material and a lithium conductive polymer as electrolyte.

Geostrophic transport in the Brazil current region north of 20°S

Abstract: Geostrophic volume transports in the upper 500 m are computed from historical hydrographic data for the area off the Brazilian coast west of 30°W and between 7° and 20°S. On the basis of water mass distributions, potential density surfaces of σθ = 27.05 kg m−3 (360–670 m) and σθ = 27.6 kg m−3 (∼1200 m) are used for referencing the meridional and zonal components of the geostrophic shears, respectively. Near 15°S a northwestward flow of 8 Sv crosses 30°W. This current reaches the shelf near 10°S in February and March, the only two months for which observations are available near that latitude along the coast; of the 8 Sv, about 4 Sv continue towards the northwest into the North Brazil Current while another branch also carrying 4 Sv turns southward as the beginning of the Brazil Current. Between 10° and 20°S the Brazil Current does not appear to strengthen appreciably, but because of the likely existence of flow on the shelf these transport values represent lower limits to the actual ones. At 30°W, another westward flow of approximately 8–10 Sv enters the area near 10°S and serves to strengthen the North Brazil Current. The total transfer of 12 Sv or more from the South Equatorial Current into the North Brazil Current and later to other currents and the northern hemisphere may be an important factor contributing to the well-known weakness of the Brazil Current in its more northerly latitudes.

Hyalohyphomycosis by Paecilomyces lilacinus in a renal transplant patient and a review of human Paecilomyces species infections

Abstract: A case of hyalohyphomycosis caused by Paecilomyces lilacinus is described in a renal transplant patient. Infection was localized on the left forearm. Two separate cultures of the lesions yielded the same organism. Histological sections disclosed hyaline elements in the tissue. The infection responded well to therapy with oral griseofulvin (500 mg daily) and the patient was cured within 45 days. Forty-six cases of human infection due to Paecilomyces species have been reported previously in the literature, most of them occurring in conjunction with prosthesis implants or immunosuppression. The antifungal sensitivity of Paecilomyces varies widely among the species but the general trend is for Paecilomyces variotii isolates to be almost universally sensitive to amphotericin B and 5-fluorocytosine, while P. lilacinus and Paecilomyces marquandii isolates are resistant to these antifungals but sensitive to the imidazoles.

The Cananéia Lagoon estuarine system, São Paulo, Brazil.

Abstract: The Cananeia Lagoon estuarine system lies at 25°S, near the latitudinal limit for mangroves. It is 110 km long, consisting of 1–3 km wide channels behind a barrier island, with narrow inlets at the southern and northern ends. Average and maximum depths are 6 m and 12 m. The system is microtidal and subtropical. Mean annual temperature is 21.4°C (annual amplitude=7.0°C). When the area receives sporadic frosts, temperatures close to 2°C occur in the estuary. Annual precipitation (2,270 mm) exceeds annual potential evapotranspiration (1,656 mm). The water budget of the 1,339 km2 watershed is controlled primarily by local rainfall. Before 1978, a large river discharged a significant portion of its flow into the lagoon, but closure of the diversionary channel has since caused changes in salinity, phytoplankton populations, and mangrove coverage. About 90 km2 of intertidal habitat is occupied by mangroves and tidal marsh; mangroves are dominant. Fringe and riverine forests (dominated byRhizophora) are more structurally developed than the basins dominated byLaguncularia and have higher litterfall rates (2.08 g m−2 d−1, fringes; 1.04 g m−2d−1, basins). Primary production exhibits pronounced seasonal pulses; heterotrophic processes lag photosynthetic production and are partially driven by particulate matter inputs. Synthetic models must consider the spatial and temporal heterogeneity of this region.

Latissimus dorsi cardiomyoplasty in the treatment of patients with dilated cardiomyopathy.

Abstract: Stimulated skeletal muscle grafts have been proposed as a means to reinforce ventricular wall in the treatment of severe myocardial failure. Latissimus dorsi cardiomyoplasty was performed in 11 patients with advanced heart failure due to cardiomyopathy who were in New York Heart Association (NYHA) class III or IV despite maximal medical therapy. There were no operative deaths. Eight patients were followed for a mean of 10.8 months. Two patients remain in muscle conditioning protocol. One patient died with latissimus dorsi ischemia and congestive heart failure. Four of the eight patients in long-term follow-up are in NYHA class I, three in class II, and one in class III. At 3 months of follow-up, rest radioisotopic left ventricular ejection fraction increased from 20.5 +/- 3.6% to 26.8 +/- 8.1% (p less than 0.01). Doppler-echocardiography demonstrated that left ventricular segmental wall shortening improved from 11.3 +/- 2.5% to 16.5 +/- 3.9% (p less than 0.01) and left ventricular stroke volume from 22.9 +/- 4.6 to 33.1 +/- 10 ml (p less than 0.01). Cardiopulmonary exercise test showed that maximal oxygen consumption during treadmill test increased from 14.8 +/- 3.7 to 18.2 +/- 3.3 ml/kg.min (p less than 0.05). At 6 months of follow-up, all the above values remained essentially unchanged. Furthermore, nonsustained ventricular tachycardia was abolished without specific medical therapy in four patients. Thus, cardiomyoplasty improves left ventricular function, reverses congestive heart failure, and may improve long-term survival in severe cardiomyopathies.