Ferida da moda: epidemiologia, diagnóstico, tratamento e experiência com eqüinos infectados no Pantanal.

A pitiose é uma doença granulomatosa que atinge eqüinos, caninos, bovinos, felinos e humanos e ocorre em áreas tropicais, subtropicais ou temperadas (Meireles et al., 1993; Mendoza et al., 1996), causada pelo omiceto Pythium insidiosum (De Cock et al., 1987). A espécie eqüina é a mais atingida, principalmente nas formas cutânea e subcutânea, seguida dos caninos (Mendoza et al., 1996). A enfermidade em eqüinos caracteriza-se pela formação de granulomas eosinofílicos, com a presença de massas necróticas chamadas de kunkers (Mendoza e Alfaro, 1986; Meireles et al., 1993). Em humanos, a doença é mais comum no sudeste asiático, caracterizando-se por formas sistêmicas com arterites e também formas oftálmicas e subcutâneas, sendo as duas últimas associadas a a e b-talassemias (Imwidthaya, 1994; Imwidthaya, 1995). Vários tratamentos têm sido utilizados, principalmente em eqüinos, incluindo tratamento químico (antifúngicos), cirúrgico e imunoterápico. A imunoterapia, proposta inicialmente por Miller (1981), surgiu como uma alternativa concreta para o controle da doença e tem apresentado resultados promissores (Monteiro, 1999). Pythium insidiosum; Epidemiologia; Pitiose nos eqüinos; Imunoterapia; Diagnóstico; Tratamento; Experiência no Pantanal; Pitiose em bovinos; Pitiose experimental; Perspecivas para o controle da pitiose.bitstream/item/79509/1/COT34.pd

The scenario of two-dimensional instabilities of the cylinder wake under EHD forcing: A linear stability analysis

We propose to study the stability properties of an air flow wake forced by a dielectric barrier discharge (DBD) actuator, which is a type of electrohydrodynamic (EHD) actuator. These actuators add momentum to the flow around a cylinder in regions close to the wall and, in our case, are symmetrically disposed near the boundary layer separation point. Since the forcing frequencies, typical of DBD, are much higher than the natural shedding frequency of the flow, we will be considering the forcing actuation as stationary. In the first part, the flow around a circular cylinder modified by EHD actuators will be experimentally studied by means of particle image velocimetry (PIV). In the second part, the EHD actuators have been numerically implemented as a boundary condition on the cylinder surface. Using this boundary condition, the computationally obtained base flow is then compared with the experimental one in order to relate the control parameters from both methodologies. After validating the obtained agreement, we study the Hopf bifurcation that appears once the flow starts the vortex shedding through experimental and computational approaches. For the base flow derived from experimentally obtained snapshots, we monitor the evolution of the velocity amplitude oscillations. As to the computationally obtained base flow, its stability is analyzed by solving a global eigenvalue problem obtained from the linearized Navier–Stokes equations. Finally, the critical parameters obtained from both approaches are compared

Numerical modelling of compound channel flow

Most natural rivers have compound cross-section. Compound channel flow is characterized by complicated three-dimensional flow structures. These structures are called secondary flows and have been classified into two categories by Prandtl (1952). He distinguished the secondary flows of the first kind and of the second kind. The secondary flows of the the second type are typically about 2-3% of the maximum streamwise velocity (Nezu and Rodi, 1985), however, they have a major impact on the mean flow and turbulence structures

Tratamento imunoterápico da pitiose equina.

A pitiose e causada pelo fungo Pythium insidiosum e acomete eqüinos, felinos, caninos, bovinos e humanos. A especie equina é a mais atingida e a lesao causada pelo fungo se restringe, geralmente, a pele e tecidos subcutaneos. Casos de pitiose com envolvimento de outros tecidos, como ossos, linfonodos, olhos, arterias e orgaos dos sistemas digestivo e respiratorio, ja foram descritos nas diferentes especies susceptiveis. Para viabilizar o uso da imunoterapia no tratamento da pitiose equina, nas condicoes dessa regiao, produziu-se e testou-se a eficiencia de um imunoterapico liofilizado (Pythium-Vac®) que permitisse armazenamento por periodo longo e em temperatura ambiente. Para o preparo do imunoterapico usaram-se isolados de P. insidiosum, obtidos de lesoes de equinos com pitiose no Pantanal e no Rio Grande do Sul. Entre março e junho de 1996, 19 animais de varias fazendas da sub-regiao da Nhecolandia, Mato Grosso do Sul, com lesoes recentes e antigas de pitiose foram reunidos na fazenda Nhumirim, da Embrapa Pantanal. Os equinos foram tratados com injecoes subcutaneas na regiao do pescoco a cada 14 dias. Sessenta e tres por cento dos animais estavam recuperados apos 5,3 aplicacoes do imunoterapico. Diferentemente do esperado, 83% dos animais com lesoes antigas e 60% com lesoes recentes foram curados. Esses resultados sao opostos aos encontrados em outros estudos sobre a eficiência do tratamento imunoterapico.bitstream/item/105021/1/COT67.pdfCNPGC

Maximum level and time to peak of dam-break waves on mobile horizontal bed

Journal of Hydraulic Engineering, Vol. 135, No. 11, November 1, 2009This experimental study focuses the influence of bed material mobility and initial downstream water level on maximum water level and time to peak of dam-break waves. It covers horizontal bed conditions on fixed bed, sand bed, and pumice bed. Results include water surface level time evolution, maxima wave levels and time to peak. The influence of bed material mobility and downstream water level was identified and characterized, stressing the importance of using mathematical models with appropriate sediment transport formulations instead of purely hydrodynamic models to simulate dam-break waves on mobile bed channels

Soft lubrication: the elastohydrodynamics of non-conforming and conforming contacts

We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g. a shell) or constitutive properties (e.g. a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving parallel to a soft layer coating a rigid substrate; a soft cylinder moving parallel to a rigid substrate; a cylindrical shell moving parallel to a rigid substrate; and finally a cylindrical conforming journal bearing coated with a thin soft layer. In addition, for the particular case of a soft layer coating a rigid substrate we consider both elastic and poroelastic material responses. For all these cases we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness parameter = hydrodynamic pressure/elastic stiffness = surface deflection/gap thickness which characterizes the fluid-induced deformation of the interface. The corresponding cases for a spherical slider are treated using scaling concepts.Comment: 61 pages, 20 figures, 2 tables, submitted to Physics of Fluid

Verification and validation of computational fluid dynamics simulations of compound channel

In this study the verification and validation of a 2nd order turbulence closure model is performed for an experimental compound channel flow, where the velocity field was measured by a Laser Doppler Velocimeter. Detailed Explicit Algebraic Reynolds Stress Model (EARSM) simulation is reported. The Grid Convergence Index (GCI) approach proposed by Roache (1998) was adopted to evaluate the uncertainty associated to grid resolution. The velocity components, the turbulent kinetic energy (TKE) and the dissipation rate were used as variables of interest. The GCI results present low values for the streamwise velocity, TKE and dissipation rate, but higher values in what concerns vertical and spanwise velocities. This indicates that the mean primary flow has converged but the secondary flow field still depends on grid resolution. Based on GCI values distribution, the mesh was locally refined. Comparison of numerical and experimental results shows good agreemen

Verification and validation of computational fluid dynamics simulations of compound channel

In this study the verification and validation of a 2nd order turbulence closure model is performed for an experimental compound channel flow, where the velocity field was measured by a Laser Doppler Velocimeter. Detailed Explicit Algebraic Reynolds Stress Model (EARSM) simulation is reported. The Grid Convergence Index (GCI) approach proposed by Roache (1998) was adopted to evaluate the uncertainty associated to grid resolution. The velocity components, the turbulent kinetic energy (TKE) and the dissipation rate were used as variables of interest. The GCI results present low values for the streamwise velocity, TKE and dissipation rate, but higher values in what concerns vertical and spanwise velocities. This indicates that the mean primary flow has converged but the secondary flow field still depends on grid resolution. Based on GCI values distribution, the mesh was locally refined. Comparison of numerical and experimental results shows good agreemen