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Search Results: 1 - 10 of 655240 matches for " J. A.;Mesquita "
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Varia??es sazonais em águas costeiras: Brasil Lat. 24o. Parte II
Mesquita, A. R. de;Harari, J.;
Boletim do Instituto Oceanográfico , 1977, DOI: 10.1590/S0373-55241977000200009
Abstract: four years data of temperature from the coastal areas of santos and cananeia are analysed in continuation of part i of this work. earlier tidal wave theories for coastal areas and some basic processes on the determination of nz are summarized. seasonal variations of temperature are found to obey approximately a general harmonic law of propagation with depth and from it estimates of the mean annual values of n are obtained. these estimates (preliminaries) seem to indicate that mixing at the coastal areas of santos is smaller than in the ones of cananéia.
Varia??es sazonais em águas costeiras: Brasil Lat. 24o. Parte II
Mesquita, A. R. de;Harari, J;
Brazilian Journal of Oceanography , 1977, DOI: 10.1590/S1679-87591977000200009
Abstract: four years data of temperature from the coastal areas of santos and cananeia are analysed in continuation of part i of this work. earlier tidal wave theories for coastal areas and some basic processes on the determination of nz are summarized. seasonal variations of temperature are found to obey approximately a general harmonic law of propagation with depth and from it estimates of the mean annual values of n are obtained. these estimates (preliminaries) seem to indicate that mixing at the coastal areas of santos is smaller than in the ones of cananéia.
Hadamard Type Variation Formulas for the Eigenvalues of the $η$-Laplacian and Applications
J. N. Gomes,M. A. M. Marrocos,R. R. Mesquita
Mathematics , 2015,
Abstract: In this paper we consider an analytic family of Riemannian structures on a compact smooth manifold $M$ with boundary. We impose the Dirichlet condition to the $\eta$-Laplacian and show the existence of analytic curves of its eigenfunctions and eigenvalues. We derive Hadamard type variation formulas. As an application we show that for a subset of $C^r$-metrics, $1\leq r<\infty$, all eigenvalues of $\eta$-Laplacian operator are generically simple. Moreover, we consider families of perturbations of domains in $M$ and obtain Hadamard type formulas for the eigenvalues of the $\eta$-Laplacian also in this case. We also establish the generic simplicity of the eigenvalues of the $\eta$-Laplacian operator in this context.
Simulation of Active Control Using Fuzzy Logic Applied to a Pulse Combustor
Botura, C. A.;Botura Jr., G.;Carvalho Jr., J. A.;Mesquita, L.;Ferreira, M. A.;
Journal of the Brazilian Society of Mechanical Sciences , 2002, DOI: 10.1590/S0100-73862002000200010
Abstract: this work analyzes an active fuzzy logic control system in a rijke type pulse combustor. during the system development, a study of the existing types of control for pulse combustion was carried out and a simulation model was implemented to be used with the package matlab and simulink. blocks which were not available in the simulator library were developed. a fuzzy controller was developed and its membership functions and inference rules were established. the obtained simulation showed that fuzzy logic is viable in the control of combustion instabilities. the obtained results indicated that the control system responded to pulses in an efficient and desirable way. it was verified that the system needed approximately 0.2 s to increase the tube internal pressure from 30 to 90 mbar, with an assumed total delay of 2 ms. the effects of delay variation were studied. convergence was always obtained and general performance was not affected by the delay. the controller sends a pressure signal in phase with the rijke tube internal pressure signal, through the speakers, when an increase the oscillations pressure amplitude is desired. on the other hand, when a decrease of the tube internal pressure amplitude is desired, the controller sends a signal 180o out of phase.
Maternal undernutrition and the offspring kidney: from fetal to adult life
Mesquita, F.F.;Gontijo, J.A.R.;Boer, P.A.;
Brazilian Journal of Medical and Biological Research , 2010, DOI: 10.1590/S0100-879X2010007500113
Abstract: maternal dietary protein restriction during pregnancy is associated with low fetal birth weight and leads to renal morphological and physiological changes. different mechanisms can contribute to this phenotype: exposure to fetal glucocorticoid, alterations in the components of the renin-angiotensin system, apoptosis, and dna methylation. a low-protein diet during gestation decreases the activity of placental 11?-hydroxysteroid dehydrogenase, exposing the fetus to glucocorticoids and resetting the hypothalamic-pituitary-adrenal axis in the offspring. the abnormal function/expression of type 1 (at1r) or type 2 (at2r) angii receptors during any period of life may be the consequence or cause of renal adaptation. at1r is up-regulated, compared with control, on the first day after birth of offspring born to low-protein diet mothers, but this protein appears to be down-regulated by 12 days of age and thereafter. in these offspring, at2r expression differs from control at 1 day of age, but is also down-regulated thereafter, with low nephron numbers at all ages: from the fetal period, at the end of nephron formation, and during adulthood. however, during adulthood, the glomerular filtration rate is not altered, due to glomerulus and podocyte hypertrophy. kidney tubule transporters are regulated by physiological mechanisms; na+/k+-atpase is inhibited by angii and, in this model, the down-regulated angii receptors fail to inhibit na+/k+-atpase, leading to increased na+ reabsorption, contributing to the hypertensive status. we also considered the modulation of pro-apoptotic and anti-apoptotic factors during nephrogenesis, since organogenesis depends upon a tight balance between proliferation, differentiation and cell death.
Salmonella spp. em forros de caixa de transporte e órg os de pintos de um dia
Rocha P.T.,Mesquita A.J.,Andrade M.A.,Louly P.R.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2003,
Abstract: Estudou-se a ocorrência de Salmonella spp. em forros de caixa de transporte e em órg os de pintos de corte de um dia, por meio de cultura bacteriológica convencional. Foram avaliadas 378 amostras de 18 lotes pertencentes a três empresas integradoras de frangos de corte do Estado de Goiás. Verificou-se a ocorrência de Salmonella spp. em 55,6 % (10/18) dos lotes sendo 10 lotes positivos oriundos de caixa de transporte e um lote de órg os de pinto de um dia. A freqüência de isolamento de Salmonella spp. nos forros de caixas foi de 11,1%, e nos órg os de pintos de corte de um dia, 3%. Os resultados sugerem a transmiss o vertical do agente. Foram isolados os sorovares Salmonella Enteritidis e Salmonella Heidelberg, o primeiro mais freqüente (92,3%).
Simulation of Active Control Using Fuzzy Logic Applied to a Pulse Combustor
Botura C. A.,Botura Jr. G.,Carvalho Jr. J. A.,Mesquita L.
Journal of the Brazilian Society of Mechanical Sciences , 2002,
Abstract: This work analyzes an active fuzzy logic control system in a Rijke type pulse combustor. During the system development, a study of the existing types of control for pulse combustion was carried out and a simulation model was implemented to be used with the package Matlab and Simulink. Blocks which were not available in the simulator library were developed. A fuzzy controller was developed and its membership functions and inference rules were established. The obtained simulation showed that fuzzy logic is viable in the control of combustion instabilities. The obtained results indicated that the control system responded to pulses in an efficient and desirable way. It was verified that the system needed approximately 0.2 s to increase the tube internal pressure from 30 to 90 mbar, with an assumed total delay of 2 ms. The effects of delay variation were studied. Convergence was always obtained and general performance was not affected by the delay. The controller sends a pressure signal in phase with the Rijke tube internal pressure signal, through the speakers, when an increase the oscillations pressure amplitude is desired. On the other hand, when a decrease of the tube internal pressure amplitude is desired, the controller sends a signal 180o out of phase.
Arterial hypotension at admission as a right ventricle dysfunction marker in patients with pulmonary embolism
A Volschan, M Knibel, PCP Souza, ET Mesquita, J Pantoja, E Cantarino, on behalf of the EMEP Investigators
Critical Care , 2001, DOI: 10.1186/cc1350
Abstract: To evaluate the relation between arterial hypotension and RVD in patients with PE.Data were collected from a cohort of 202 patients (84 men) enrolled in a multicenter prospective registry study of PE. The mean age was 70.9 ± 13.8 years. Patients were admitted to hospitals between January 1998 and January 2001. The diagnosis of PE was confirmed if patients fulfilled at least one of the following criteria: (1) pulmonary artery thrombus visualization by pulmonary arteriography, helicoidal angiotomography, magnetic resonance or echocardiography; (2) high probability pulmonary scintigraphy; and (3) venous duplex scan with thrombus visualization and clinical signs and symptoms of PE. Arterial hypotension was considered if systolic arterial blood pressure was below 90 mmHg, at admission. The transthoracic echocardiogram (TTE) were performed in 193 patients and the RVD was established by subjective analysis of right ventricle function.Arterial hypotension was present in 40 (21%) and the TTE showed RVD in 73 (38%). Arterial hypotension was detected in 21 (29%) patients in RVD group versus 19 (16%) patients in the group without RVD (P = 0.03). The diagnostic accuracy of arterial hypotension regarding RVD was measured as follows: sensitivity 29% and specificity 84%, with a positive predictive value of 52.5% and negative predictive value of 66%. The likelihood ratio of positive test was 1.82 and the likelihood ratio of negative test was 0.85.Arterial hypotension is not a good marker of RVD in patients with PE.
The electrocardiogram as a predictor of right ventricular dysfunction in patients with pulmonary embolism
A Volschan, M Knibel, PCP Souza, ET Mesquita, J Pantoja, E Cantarino, on behalf of the EMEP Investigators
Critical Care , 2001, DOI: 10.1186/cc1349
Abstract: To evaluate the prevalence of ECG changes in patients with PE and its importance as a diagnostic tool in the diagnosis of RVD.Data were collected from a cohort of 202 patients (84 men) enrolled in a multicenter prospective registry study of PE. The mean age was 70.9 ± 13.8 years. Patients were admitted to hospital between January 1998 and January 2001. The diagnosis of PE was confirmed if patients fulfilled at least one of the following criteria: (1) pulmonary artery thrombus visualization by pulmonary arteriography, helicoidal angiotomography, magnetic resonance or echocardiography; (2) high probability pulmonary scintigraphy; and (3) venous duplex scan with thrombus visualization and clinical signs and symptoms of PE. The ECG and transthoracic echocardiogram (TTE) were performed in 190 patients. RVD was established by TTE subjective analysis of the right ventricle contractive function. Abnormal ECG was considered to be indicative of right bundle branch block, S1Q3T3 pattern, negative Twave from V1 to V4, or right AQRS axis deviation.ECG was abnormal in 33% of patients and TTE analysis showed RVD in 38%. In this latter group of patients 49% presented with at least one ECG change. At least one ECG change was found in 23% of patients without RVD (P < 0.0001). The accuracy of ECG for the diagnosis of RVD was: sensitivity 49%, specificity 77%, positive predictive value 57% and negative predictive value 71%. The likelihood ratio of a positive test was 2.1 and of a negative test was 0.6.When transthoracic echocardiography is not available, ECG may be useful to exclude right ventricular dysfunction in patients with PE.
Vegetation structure in cerrado physiognomies in South-eastern Brazil
BATALHA, M. A.;MANTOVANI, W.;MESQUITA JúNIOR, H. N. de;
Brazilian Journal of Biology , 2001, DOI: 10.1590/S1519-69842001000300018
Abstract: we studied three cerrado physiognomies (campo cerrado, a savanna woodland; cerrado sensu stricto, a woodland; and cerrad?o, a tall woodland) in a reserve with 1,225 ha, in santa rita do passa-quatro (21°36-38's and 47°36-39'w), s?o paulo state, south-eastern brazil, to compare plant communities structure. as descriptors of the vegetation structure, we used richness, density, basal area, cylindrical volume, and diversity. ten 40 m2 quadrats were placed randomly in each physiognomy, in which we sampled the woody plants with stem diameter equal or larger than 1 cm (woody component), and ten 2.5 m2 quadrats, in which we sampled the woody plants with stem diameter smaller than 1 cm and all the non-woody individuals (herbaceous component). in the woody component, we found significant differences among the physiognomies for richness, density and cylindrical volume. cylindrical volume increased from campo cerrado to cerrad?o, but richness and density were higher in cerrado sensu stricto. in the herbaceous component, we detected differences for all variables, which were higher in the savanna physiognomies, campo cerrado and cerrado sensu stricto, than in the forest physiognomy, cerrad?o. cylindrical volume was the best variable to distinguish the physiognomies. floristic similarity followed the campo cerrado-cerrado sensu stricto-cerrad?o gradient, and b diversity was higher in the herbaceous component.
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