Circulation and suspended particulate matter transport in a tidally dominated estuary: caravelas estuary, Bahia, Brazil

The circulation and transport of suspended particulate matter in the Caravelas Estuary are assessed. Nearly-synoptic hourly hydrographic, current (ADCP velocity and volume transport) and suspended particulate matter data were collected during a full semidiurnal spring tide, on the two transects Boca do Tomba and Barra Velha and on longitudinal sections at low and high tide. On the first transect the peak ebb currents (-1.5 ms-1) were almost twice as strong as those of the wider and shallow Barra Velha inlet (-0.80 ms-1) and the peak flood currents were 0.75 and 0.60 ms-1, respectively. Due to the strong tidal currents both inlets had weak vertical salinity stratification and were classified with the Stratification-circulation Diagram as Type 2a (partially mixed-weakly stratified) and Type 1a (well mixed). Volume transports were very close, ranging from -3,500 to 3,100 m³s-1 at the ebb and flood, respectively, with a residual -630 m³s-1. The concentration of the suspended particulate matter was closely related to the tidal variation and decreased landwards from 50 mg.L-1 at the estuary mouth, to 10 mg.L-1 at distances of 9 and 16 km for the low and high tide experiments, respectively. The total residual SPM transport was out of the estuary at rates of -18 tons per tidal cycle.

Presença de culicídeos em município de porte médio do Estado de São Paulo e risco de ocorrência de febre do Nilo Ocidental e outras arboviroses

INTRODUÇÃO: O objetivo deste estudo foi mensurar a diversidade de espécies de culicídeos, descrever sua abundância e variação sazonal em áreas urbanas e matas de São José do Rio Preto, SP, e discutir o risco de ocorrência de arboviroses. MÉTODOS: Coletas de larvas e de mosquitos adultos foram realizadas mensalmente, em 2006 e 2007, em área urbana e em quatro fragmentos de mata. No perímetro urbano, coletaram-se larvas nos sítios mais prováveis de oviposição para mosquitos do gênero Culex e nas matas foi realizada a coleta de mosquitos adultos, sendo que em duas utilizaram-se armadilhas CDC à noite e, em duas, aspirador de Nasci de dia. RESULTADOS: Na área urbana identificaram-se 34 espécies de culicídeos em um total de 8.683 exemplares; destes, 80,7% corresponderam ao Culex quinquefasciatus, 9,6% ao Culex grupo Coronator, 3,2% ao Aedes albopictus (3,2%) e 1,1% ao Ochlerotatus fluviatilis. A abundância de larvas de Cx. quinquefasciatus correlacionou-se negativamente com a chuva. Nas quatro matas, foram coletados 2.268 mosquitos distribuídos entre 10 gêneros, 46 espécies ou grupos. As mais abundantes foram Aedeomyia squamipennis, Culex. coronator, Culex (Mel.) seção Melanoconion, Culex declarator, Ochlerotatus scapularis, Anopheles triannulatus, Culex bidens/interfor e Culex habilitator/pseudojhantinosoma. CONCLUSÕES: A abundância de Cx. quinquefasciatus na área urbana e a presença de outros culicídeos nas áreas urbanas e de matas apontam para a possibilidade de transmissão do vírus do Nilo Ocidental e de outras arboviroses em São José do Rio Preto e outras cidades do Brasil, sendo fundamental o estabelecimento de medidas visando à vigilância destas arboviroses.

Establishment of a protocol for obtention of neuronal stem cells lineages from the dog olfactory epithelium

A morphological and cell culture study from nasal mucosa of dogs was performed in order to establish a protocol to obtain a cell population committed to neuronal lineage, as a proposal for the treatment of traumatic and degenerative lesions in these animals, so that in the future these results could be applied to the human species. Twelve mongrel dogs of 60-day aged pregnancy were collected from urban pound dogs in São Paulo. Tissue from cribriform ethmoidal lamina of the fetuses was collected at necropsy under sterile conditions around 1h to 2h postmortem by uterine sections and sections from the fetal regions described above. Isolated cells of this tissue were added in DMEM/F-12 medium under standard conditions of incubation (5% CO², >37ºC). Cell culture based on isolated cells from biopsies of the olfactory epithelium showed rapid growth when cultured for 24 hours, showing phase-bright sphere cells found floating around the fragments, attached on culture flasks. After 20 days, a specific type of cells, predominantly ellipsoids or fusiform cells was characterized in vitro. The indirect immunofluorescence examination showed cells expressing markers of neuronal precursors (GFAP, neurofilament, oligodendrocyte, and III â-tubulin). The cell proliferation index showed Ki67 immunostaining with a trend to label cell groups throughout the apical region, while PCNA immunostaining label predominantly cell groups lying above the basal lamina. The transmission electron microscopy from the olfactory epithelium of dogs revealed cells with electron-dense cytoplasm and preserving the same distribution as those of positive cell staining for PCNA. Metabolic activity was confirmed by presence of euchromatin in the greatest part of cells. All these aspects give subsidies to support the hypothesis about resident progenitor cells among the basal cells of the olfactory epithelium, committed to renewal of these cell populations, especially neurons.

Morphological aspects of buffaloes (Bubalus bubalis) umbilical cord

Buffalo is an important livestock resource, with a great participation in agricultural systems, providing milk, meat, and work power. Umbilical cord is responsible for maternal-fetal nutrients exchange during pregnancy, and its alterations can compromise the fetal development. We investigated ten pregnant uteruses collected from cross-bread buffaloes in different stages of gestation. Pregnancy and fetal age was determined by measuring the apex sacral length and development period was calculated by previously published formula. Umbilical cords were measured for length determination. Umbilical cord vascular net and anastomosis were observed by injection of Neoprene latex. Histological sections of the umbilical cord were studied after stain with HE, picrossirius, toluidine blue, orceine, and PAS reaction. Buffaloes' umbilical cord was formed by two central arteries, an allantois duct and two peripheral veins. The artery wall was composed by large quantity of collagen, elastic fibers, fibroblasts and large number of vasa vasorum. The allantois duct was located between the arteries and presented a great number of small nourishing vessels. Small nourishing vessels should be carefully considered to avoid to be mistaken to the arterials and veins vasa vasorum. Medium length of umbilical cord from buffalos was 11.8cm (minimum of 6.8cm and maximum of 17.4cm).

AT1-receptor mediated vascular damage in myocardium, kidneys and liver in rats

The systemic aspect of vascular damage induced by angiotensin II (ANG II) has been poorly explored in the literature. Considering the presence of ANG II and its specific receptor AT1, in several organs, all tissues might be potentially affected by its effects. The aims of this study were: To evaluate the early histological changes in the heart, liver and kidneys, produced by ANG II infusion, to evaluate the protective effect of losartan. Wistar rats were distributed into three groups: control (no treatment), treated with ANG II, and treated with ANG II + losartan. ANG II was continuously infused over 72 hours by subcutaneous osmotic pumps. Histological sections of the myocardium, kidneys and liver were stained and observed for the presence of necrosis. There were ANG II-induced perivascular inflammation and necrosis of the arteriolar wall in the myocardium, kidney, and liver by, which were partially prevented by losartan. There was no significant correlation between heart and kidney damage. Tissue lesion severity was lower than that of vascular lesions, without statistical difference between groups. ANG II causes vascular injury in the heart, kidneys and liver, indicating a systemic vasculotoxic effect; the mechanisms of damage/protection vary depending on the target organ; perivascular lesions may occur even when anti-hypertensive doses of losartan are used.

Achados clínico patológicos durante um surto de disenteria de inverno em bovinos no Rio Grande do Sul

Descreve-se um surto de disenteria de inverno que afetou 10 vacas leiteiras de uma propriedade localizada em Viamão, Rio Grande do Sul. O quadro clínico caracterizou-se por uma diarréia inicialmente líquida esverdeada com estrias de sangue e muco, evoluindo, em alguns animais, para uma diarréia de coloração marrom escura à sanguinolenta, que persistiu, em média, cinco dias. Drástica diminuição na produção de leite e no consumo de alimentos, além de graus variados de depressão também foram observados. Apenas um dos 10 animais afetados morreu. Durante a necropsia, observaram-se mucosas pálidas, conteúdo sanguinolento com presença de grande quantidade de coágulos, principalmente no cólon espiral e petéquias na mucosa do cólon. Os principais achados histológicos foram encontradas no cólon espiral, onde havia criptas dilatadas, sem epitélio de revestimento ou revestidas por epitélio pavimentoso e/ou cuboidal, por vezes com núcleos grandes e nucléolos proeminentes. Algumas criptas eram preenchidas por debris necróticos e polimorfonucleares. Na imuno-histoquímica com anticorpo monoclonal para coronavírus bovino (8F2) em cortes do cólon espiral, havia marcações positivas no citoplasma de enterócitos das criptas, nos debris necróticos destas e em macrófagos na lâmina própria.

Expression and distribution of connexin 32 in rat liver with experimentally induced fibrosis

The connexin 32 (Cx32) is a protein that forms the channels that promote the gap junction intercellular communication (GJIC) in the liver, allowing the diffusion of small molecules through cytosol from cell-to-cell. Hepatic fibrosis is characterized by a disruption of normal tissue architeture by cellular lesions, and may alter the GJIC. This work aimed to study the expression and distribution of Cx32 in liver fibrosis induced by the oral administration of dimethylnitrosamine in female Wistar rats. The necropsy of the rats was carried out after five weeks of drug administration. They presented a hepatic fibrosis state. Sections from livers with fibrosis and from control livers were submitted to immunohistochemical, Real Time-PCR and Western-Blot analysis to Cx32. In fibrotic livers the Cxs were diffusely scattered in the cytoplasm, contrasting with the control livers, where the Cx32 formed junction plaques at the cell membrane. Also it was found a decrease in the gene expression of Cx32 without reduction in the protein quantity when compared with controls. These results suggest that there the mechanism of intercellular communication between hepatocytes was reduced by the fibrotic process, which may predispose to the occurrence of a neoplastic process, taken in account that connexins are considered tumor suppressing genes.

Ornato e despojamento no mundo fabril

O artigo investiga algumas das tendências da arquitetura gerada por fábricas - galpões industriais, moradias, igrejas, escolas, clubes etc. -, erguida no Brasil entre as duas últimas décadas do século XIX e as primeiras do XX. Apoia-se em amplo inventário, como base para um esforço de análise que se propõe a identificar os temas e usos predominantes dos ornatos aplicados a construções geradas por fábricas, as referências historicistas mobilizadas e eventuais rupturas de signos arquitetônicos tipológicos, e, no limite, a abolição de ornatos e dos referidos signos. Assim, de um lado, trata da penetração da linguagem eclética nessas construções, investigando o repertório formal utilizado em diferentes tipologias. De outro, trata da simultânea difusão de uma estética tipicamente fabril, fundamentada em noções de economia, eficiência, utilidade e funcionalidade. Mostra como tais noções se expressam ora em uma simplificação ou ausência de ornatos, ora no uso de ornatos cujos temas remetem ao mundo das máquinas; às vezes, no distanciamento ou abandono de signos arquitetônicos tipológicos consagrados; ou, ainda, no emprego de materiais produzidos industrialmente e que se difundiram a partir, sobretudo, da arquitetura de fábricas.

Immediate reconstruction following breast-conserving surgery: management of the positive surgical margins and influence on secondary reconstruction

The efficacy of breast-conserving surgery for the local control of early breast cancer has been repeatedly evidenced. Although immediate reconstruction following breast-conserving surgery has been described, little information is available regarding surgical management in reoperative settings due to positive margins. We studied the influence of intraoperatively assessed and postoperatively controlled surgical margin status on the type of breast-conserving surgery and report our results regarding complications in a reoperative breast reconstruction scenario. All patients were seen by a multidisciplinary team who recommended breast-conserving surgery. According to the breast volume, ptosis and tumor size/location, the patients were also evaluated by a plastic surgeon, who recommended reconstruction with the appropriate technique. Intraoperative assessment of surgical margins was determined by histological examination of frozen sections. The mean follow-up time was 48months. Two hundred and eighteen patients (88.5 per cent ) underwent breast-conserving surgery and immediate reconstruction. Twelve (5.5 per cent ) patients had a positive tumor margin after review of the permanent section. All patients underwent re-exploration. In 1.3 per cent , a second reconstructive technique was indicated and in 2.2 per cent a skin-sparing mastectomy with total reconstruction was performed. Our findings support the important role of the intraoperative assessment of surgical margins and its interference in the selection of reconstruction techniques and negative margins; however, it will not guarantee complete excision of the tumor. Success depends on coordinated planning with the oncologic surgeon and careful intraoperative management

Turbulence in collisionless plasmas: statistical analysis from numerical simulations with pressure anisotropy

In recent years, we have experienced increasing interest in the understanding of the physical properties of collisionless plasmas, mostly because of the large number of astrophysical environments (e. g. the intracluster medium (ICM)) containing magnetic fields that are strong enough to be coupled with the ionized gas and characterized by densities sufficiently low to prevent the pressure isotropization with respect to the magnetic line direction. Under these conditions, a new class of kinetic instabilities arises, such as firehose and mirror instabilities, which have been studied extensively in the literature. Their role in the turbulence evolution and cascade process in the presence of pressure anisotropy, however, is still unclear. In this work, we present the first statistical analysis of turbulence in collisionless plasmas using three-dimensional numerical simulations and solving double-isothermal magnetohydrodynamic equations with the Chew-Goldberger-Low laws closure (CGL-MHD). We study models with different initial conditions to account for the firehose and mirror instabilities and to obtain different turbulent regimes. We found that the CGL-MHD subsonic and supersonic turbulences show small differences compared to the MHD models in most cases. However, in the regimes of strong kinetic instabilities, the statistics, i.e. the probability distribution functions (PDFs) of density and velocity, are very different. In subsonic models, the instabilities cause an increase in the dispersion of density, while the dispersion of velocity is increased by a large factor in some cases. Moreover, the spectra of density and velocity show increased power at small scales explained by the high growth rate of the instabilities. Finally, we calculated the structure functions of velocity and density fluctuations in the local reference frame defined by the direction of magnetic lines. The results indicate that in some cases the instabilities significantly increase the anisotropy of fluctuations. These results, even though preliminary and restricted to very specific conditions, show that the physical properties of turbulence in collisionless plasmas, as those found in the ICM, may be very different from what has been largely believed.

Students' collective knowledge construction in the virtual learning environment ""ToLigado - your school interactive newspaper""

Introduction. The ToLigado Project - Your School Interactive Newspaper is an interactive virtual learning environment conceived, developed, implemented and supported by researchers at the School of the Future Research Laboratory of the University of Sao Paulo, Brazil. Method. This virtual learning environment aims to motivate trans-disciplinary research among public school students and teachers in 2,931 schools equipped with Internet-access computer rooms. Within this virtual community, students produce collective multimedia research documents that are immediately published in the portal. The project also aims to increase students' autonomy for research, collaborative work and Web authorship. Main sections of the portal are presented and described. Results. Partial results of the first two years' implementation are presented and indicate a strong motivation among students to produce knowledge despite the fragile hardware and software infrastructure at the time. Discussion. In this new environment, students should be seen as 'knowledge architects' and teachers as facilitators, or 'curiosity managers'. The ToLigado portal may constitute a repository for future studies regarding student attitudes in virtual learning environments, students' behaviour as 'authors', Web authorship involving collective knowledge production, teachers' behaviour as facilitators, and virtual learning environments as digital repositories of students' knowledge construction and social capital in virtual learning communities.

Chaotic Patterns in Aeroelastic Signals

This work presents the analysis of nonlinear aeroelastic time series from wing vibrations due to airflow separation during wind tunnel experiments. Surrogate data method is used to justify the application of nonlinear time series analysis to the aeroelastic system, after rejecting the chance for nonstationarity. The singular value decomposition (SVD) approach is used to reconstruct the state space, reducing noise from the aeroelastic time series. Direct analysis of reconstructed trajectories in the state space and the determination of Poincare sections have been employed to investigate complex dynamics and chaotic patterns. With the reconstructed state spaces, qualitative analyses may be done, and the attractors evolutions with parametric variation are presented. Overall results reveal complex system dynamics associated with highly separated flow effects together with nonlinear coupling between aeroelastic modes. Bifurcations to the nonlinear aeroelastic system are observed for two investigations, that is, considering oscillations-induced aeroelastic evolutions with varying freestream speed, and aeroelastic evolutions at constant freestream speed and varying oscillations. Finally, Lyapunov exponent calculation is proceeded in order to infer on chaotic behavior. Poincare mappings also suggest bifurcations and chaos, reinforced by the attainment of maximum positive Lyapunov exponents. Copyright (C) 2009 F. D. Marques and R. M. G. Vasconcellos.

Trapezoidal cross-sectional influence on FinFET threshold voltage and corner effects

Fin field effect transistors (FinFETS) are silicon-on-insulator (SOI) transistors with three-dimensional structures. As a result of some fabrication-process limitations (as nonideal anisotropic overetch) some FinFETs have inclined surfaces, which results in trapezoidal cross sections instead of rectangular sections, as expected. This geometric alteration results in some device issues, like carrier profile, threshold voltage, and corner effects. This work analyzes these consequences based on three-dimensional numeric simulation of several dual-gate and triple-gate FinFETs. The simulation results show that the threshold voltage depends on the sidewall inclination angle and that this dependence varies according to the body doping level. The corner effects also depend on the inclination angle and doping level. (C) 2008 The Electrochemical Society.

Resprouting from roots in four Brazilian tree species

Previous studies pointed out that species richness and high density values within the Leguminosae in Brazilian forest fragments affected by fire could be due, at least partially, to the high incidence of root sprouting in this family. However, there are few Studies of the factors that induce root sprouting in woody plants after disturbance. We investigated the bud formation on root cuttings, and considered a man-made disturbance that isolates the root from the shoot apical dominance of three Leguminosae (Bauhinia forficata Link., Centrolobium tomentosum Guill. ex Benth, and Inga laurina (Sw.) Willd) and one Rutaceae (Esenbeckia febrifuga (St. Hit.) Juss. ex Mart.). All these species resprout frequently after fire. We also attempted to induce bud formation on root systems by removing the main trunk, girdling or sectioning the shallow lateral roots from forest tree species Esenbeckia febrifuga and Hymenaea courbaril L. We identified the origin of shoot primordia and their early development by fixing the samples in Karnovsky solution, dehydrating in ethyl alcohol series and embedding in plastic resin. Serial sections were cut on a rotary microtome and stained with toluidine blue O. Permanent slides were mounted in synthetic resin. We observed different modes of bud origin on root cuttings: close to the vascular cambium (C. tomentosum), from the callus (B. forficata and E febrifuga) and from the phloematic parenchyma proliferation (L laurina). Fragments of B. forficala root bark were also capable of forming reparative buds from healing phellogen formed in callus in the bark's inner side. In the attempt of bud induction on root systems, Hymenaea courbaril did not respond to any of the induction tests, probably because of plant age. However, Esenbeckia febrifuga roots formed suckers when the main trunk was removed or their roots were sectioned and isolated from the original plant. We experimentally demonstrated the ability of four tree species to resprout from roots after disturbance. Our results suggest that the release of apical dominance enables root resprouting in the studied species. Rev. Biol. Trop. 57 (3): 789-800. Epub 2009 September 30.

WOOD DENSITY VARIATION AND TREE RING DEMARCATION IN Gmelina arborea TREES USING X-RAY DENSITOMETRY

Due to its relationship with other properties, wood density is the main wood quality parameter. Modern, accurate methods - such as X-ray densitometry - are applied to determine the spatial distribution of density in wood sections and to evaluate wood quality. The objectives of this study were to determinate the influence of growing conditions on wood density variation and tree ring demarcation of gmelina trees from fast growing plantations in Costa Rica. The wood density was determined by X-ray densitometry method. Wood samples were cut from gmelina trees and were exposed to low X-rays. The radiographic films were developed and scanned using a 256 gray scale with 1000 dpi resolution and the wood density was determined by CRAD and CERD software. The results showed tree-ring boundaries were distinctly delimited in trees growing in site with rainfall lower than 25 10 mm/year. It was demonstrated that tree age, climatic conditions and management of plantation affects wood density and its variability. The specific effect of variables on wood density was quantified by for multiple regression method. It was determined that tree year explained 25.8% of the total variation of density and 19.9% were caused by climatic condition where the tree growing. Wood density was less affected by the intensity of forest management with 5.9% of total variation.