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Search Results: 1 - 10 of 333969 matches for " Rodrigo S.;Cotta "
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Lixivia??o de nitrato de um substrato minerado tratado com lodo de esgoto doméstico
Paula, Rodrigo ávila de;Corrêa, Rodrigo Studart;Cotta, Taís Pitta;
Bragantia , 2011, DOI: 10.1590/S0006-87052011000100016
Abstract: sewage sludges are significant sources of n, p, organic matter, and other elements for plant nutrition. soil and spoil application of such residues is one of the most efficient ways of nutrient recovery. however, the benefits from sewage sludge soil application have to be weighed against sanitary and environmental risks such as excessive nitrate leaching, which may contaminate water. sanitary and environmental regulations have banned human consumption of waters with nitrate concentrations > 10 mg l-1. therefore, this work aimed to measure the risk of groundwater contamination by nitrate produced in a mined spoil treated with 120 t ha-1 of domestic sewage sludge on wet basis. the amended spoil leached solutions with concentrations up to 78 mg l-1 of nitrate, which poses risks to underground water. under the experimental conditions set in this work, the groundwater table has to rest at 4.5 m depth or deeper to allow the leachate diluting through the soil profile to concentrations < 10 mg l-1, if the soil remains bare. a grass cover on the amended spoil decreased by 40% the amount of nitrate in the leachate and it would allow a groundwater table at 2.5 m depth without an excessive nitrate input from the top sewage sludge amended layer.
Retroperitoneoscopic nephrectomy in benign pathology
Quintela, Rodrigo S.;Cotta, Leonardo R.;Neves, Marcelo F.;Abelha Jr, David L.;Tavora, Jose E.;
International braz j urol , 2006, DOI: 10.1590/S1677-55382006000500004
Abstract: introduction: we report our experience with 43 retroperitoneal laparoscopic nephrectomy for benign kidney disease. materials and methods: all patients had a poor function from obstructive uropathology and renal atrophy. none of these patients had a previous lumbotomy. retroperitoneoscopy was performed with 4 trocar port technique in a lateral position. the retroperitoneal space is created by using a gaur's balloon made of sterile glove. the approach to vascular pedicle was done posteriorly and vessels were clipped by metal and hem-o-lock (weck closure systems, north carolina, usa) clips. the sample was intact extracted in an endo-bag prolonging one trocar incision. results: median operative time was 160 minutes and median blood loss was 200 ml. four cases (9%) were converted to open surgery: one case due to bleeding and 3 cases due to technical difficulties regarding perirenal adherences. most patients (39) checked out from the hospital in day two. four of them were left over 3 days due to wound complications. conclusions: retroperitoneoscopy offers a safe, effective and reproductive access to nephrectomy for benign pathologies.
Determination of oscillator strength of confined excitons in a semiconductor microcavity
E. A. Cotta,P. M. S. Roma
Physics , 2014, DOI: 10.5488/CMP.17.23702
Abstract: We have achieved a significant experimental Rabi-splitting (3.4 meV) for confined polaritons in a planar semiconductor $\lambda$ microcavity for only a single quantum well (SQW) of GaAs (10 nm) placed at the antinode. The Rabi-splitting phenomena are discussed in detail based on the semiclassical theory, where two coupled harmonic oscillators (excitons and photons) are used to describe the system. In this way, we can obtain the dispersion curve of polaritons, the minimum value for the cavity reflectance and the oscillator strength to reach the strong coupling regime. This approach describes an ensemble of excitons confined in a SQW and includes a dissipation component. The results present a weak coupling regime, where an enhanced spontaneous emission takes place, and a strong coupling regime, where Rabi-splitting in the dispersion curve can be observed. The theoretical results are confronted with experimental data for the reflectance behavior in resonant and off-resonant conditions and present a great accuracy. This allows us to determine the oscillator strength of the confined excitons in the SQW with great precision.
Estudo clínico e padr o de heran a em pacientes com retinose pigmentar Clinical study and pattern of inheritance in patients with retinitis pigmentosa
Ana Cristina Cotta de Queiroz,Maria Frasson,Carlos Eduardo dos Reis Veloso,Rodrigo Rezende Arantes
Revista Brasileira de Oftalmologia , 2013,
Abstract: OBJETIVO: Realizar análise epidemiológica de pacientes com retinose pigmentar (RP), caracterizando aspectos clínicos da doen a e o padr o de heran a encontrado em nosso meio, de acordo com a presen a ou n o de síndrome de Usher. MéTODOS: Foram estudados 155 pacientes com RP, tendo sido a amostra dividida em 2 grupos: grupo 1 (n=130), com pacientes diagnosticados com RP clássica, sem associa o com altera es sistêmicas; e grupo 2 (n=25), com pacientes diagnosticados com Síndrome de Usher (USH). Foram caracterizados aspectos clínicos da doen a (sexo, idade, sintomas oculares, acuidade visual, altera es do segmento anterior e posterior e altera es em exames complementares) e o padr o de heran a encontrado. Os dados foram obtidos através de anamnese, exame oftalmológico completo e exames subsidiários (campo visual manual, eletrorretinograma, retinografia simples e fluorescente), no período de fevereiro de 2003 a dezembro de 2009. Foi utilizado o programa SPSS vers o 13.0 para análise dos dados estatísticos. RESULTADOS: A heran a autoss mica recessiva foi a forma mais comumente encontrada (76,2% no grupo 1), mas em propor o maior do que a de outros trabalhos da literatura. Um menor número de casos com padr o recessivo ligado ao X (1,5%) também foi notado no grupo 1. N o houve diferen a estatisticamente significante entre as características clínicas entre os dois grupos. CONCLUS O: O padr o de heran a encontrado nos pacientes com RP clássica foi similar ao encontrado em outros trabalhos. As características clínicas foram semelhantes nos dois grupos estudados. OBJECTIVE: To make an epidemiological analysis of patients with retinitis pigmentosa (RP), characterizing clinical aspects of the disease and the pattern of inheritance found in the population studied, according to the presence or not of Usher Syndrome. METHODS: 155 patients with RP were studied and the sample was divided into two groups: group 1 (n = 130) with patients diagnosed with classical RP not associated with systemic symptoms; and group 2 (n = 25) with patients diagnosed with Usher syndrome (USH). We characterized clinical aspects of the disease (sex, age, ocular symptoms, visual acuity and anterior and posterior segment changes) and the pattern of inheritance. Data were obtained through medical history, complete ophthalmic examination and complementary exams (manual visual field, electroretinogram, retinography and fluorescent angiography) for the period of February 2003 to December 2009. We used SPSS version 13.0 for statistical data analysis. RESULTS: The autosomal recessive inheritance w
Role of Extracellular Matrix-Mediated Interactions in Thymocyte Migration
Wilson Savino,Sérgio Ranto Dalmau,Vinícius Cotta Dealmeida
Clinical and Developmental Immunology , 2000, DOI: 10.1155/2000/60247
Abstract: Cell adhesion, migration, differentiation and survival or death is amongst a large spectrum of biological responses that can be elicited by ligation of extracellular matrix components to their corresponding receptors. As regards the physiology of the thymus, cell migration is a crucial event in the general process of T cell differentiation. Studies on the intrathymic distribution of ECM components revealed that fibronectin, laminin and type IV collagen, are not restrictedly located at typical basement membrane sites, also forming a thick network in the medullary region of the thymic lobules, whereas very thin ECM fibers are found within the cortex. These ECM components are essentially produced by thymic microenvironmental cells, which also drive thymocyte differentiation. Signals triggered by ECM are conveyed into thymocytes or microenvironmental cells through specific membrane receptors, and most of them belong to the integrin type, such as the VLA-3, VLA-4, VLA-5 and VLA-6. In vitro studies revealed that adhesion of thymocytes to thymic microenvironmental cells is mediated by extracellular matrix. Such an adhesion is preferentially done by immature thymocytes. Importantly, ECM-mediated interactions also govern the entrance and exit of thymocytes in the lymphoepithelial complexes named thymic nurse cells. Lastly, pathological conditions, including infectious and autoimmune diseases, in which changes of ECM ligands and receptors are observed, course with alterations in thymocyte migration and death. In conclusion, the fact that ECM can modulate traffic, differentiation, death and survival of normal thymocytes adds clues for understanding how ECM-mediated interactions behave in the thymus, not only in normal, but also in pathological conditions.
Three-dimensional BF Theories and the Alexander-Conway Invariant of Knots
A. S. Cattaneo,P. Cotta-Ramusino,M. Martellini
Physics , 1994, DOI: 10.1016/0550-3213(94)00500-E
Abstract: We study 3-dimensional BF theories and define observables related to knots and links. The quantum expectation values of these observables give the coefficients of the Alexander-Conway polynomial.
Loop observables for BF theories in any dimension and the cohomology of knots
Alberto S. Cattaneo,Paolo Cotta-Ramusino,Carlo A. Rossi
Physics , 2000,
Abstract: A generalization of Wilson loop observables for BF theories in any dimension is introduced in the Batalin-Vilkovisky framework. The expectation values of these observables are cohomology classes of the space of imbeddings of a circle. One of the resulting theories discussed in the paper has only trivalent interactions and, irrespective of the actual dimension, looks like a 3-dimensional Chern-Simons theory.
Configuration spaces and Vassiliev classes in any dimension
Alberto S. Cattaneo,Paolo Cotta-Ramusino,Riccardo Longoni
Physics , 1999, DOI: 10.2140/agt.2002.2.949
Abstract: The real cohomology of the space of imbeddings of S^1 into R^n, n>3, is studied by using configuration space integrals. Nontrivial classes are explicitly constructed. As a by-product, we prove the nontriviality of certain cycles of imbeddings obtained by blowing up transversal double points in immersions. These cohomology classes generalize in a nontrivial way the Vassiliev knot invariants. Other nontrivial classes are constructed by considering the restriction of classes defined on the corresponding spaces of immersions.
BRST Symmetries for the Tangent Gauge Group
A. S. Cattaneo,P. Cotta-Ramusino,M. Rinaldi
Mathematics , 1997, DOI: 10.1063/1.532381
Abstract: For any principal bundle $P$, one can consider the subspace of the space of connections on its tangent bundle $TP$ given by the tangent bundle $T{\cal A}$ of the space of connections ${\cal A}$ on $P$. The tangent gauge group acts freely on $T{\cal A}$. Appropriate BRST operators are introduced for quantum field theories that include as fields elements of $T{\cal A}$, as well as tangent vectors to the space of curvatures. As the simplest application, the BRST symmetry of the so-called $BF$-Yang-Mills theory is described and the relevant gauge fixing conditions are analyzed. A brief account on the topological $BF$ theories is also included and the relevant Batalin-Vilkovisky operator is described.
Algebraic structures on graph cohomology
Alberto S. Cattaneo,Paolo Cotta-Ramusino,Riccardo Longoni
Mathematics , 2003, DOI: 10.1142/S0218216505004019
Abstract: We define algebraic structures on graph cohomology and prove that they correspond to algebraic structures on the cohomology of the spaces of imbeddings of S^1 or R into R^n. As a corollary, we deduce the existence of an infinite number of nontrivial cohomology classes in Imb(S^1,R^n) when n is even and greater than 3. Finally, we give a new interpretation of the anomaly term for the Vassiliev invariants in R^3.
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