Genetic Control of Mosquitoes: population suppression strategies

Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

Modulation Techniques for Multi-Phase Converters and Control Strategies for Multi-Phase Electric Drives

The ever-increasing spread of automation in industry puts the electrical engineer in a central role as a promoter of technological development in a sector such as the use of electricity, which is the basis of all the machinery and productive processes. Moreover the spread of drives for motor control and static converters with structures ever more complex, places the electrical engineer to face new challenges whose solution has as critical elements in the implementation of digital control techniques with the requirements of inexpensiveness and efficiency of the final product. The successfully application of solutions using non-conventional static converters awake an increasing interest in science and industry due to the promising opportunities. However, in the same time, new problems emerge whose solution is still under study and debate in the scientific community During the Ph.D. course several themes have been developed that, while obtaining the recent and growing interest of scientific community, have much space for the development of research activity and for industrial applications. The first area of research is related to the control of three phase induction motors with high dynamic performance and the sensorless control in the high speed range. The management of the operation of induction machine without position or speed sensors awakes interest in the industrial world due to the increased reliability and robustness of this solution combined with a lower cost of production and purchase of this technology compared to the others available in the market. During this dissertation control techniques will be proposed which are able to exploit the total dc link voltage and at the same time capable to exploit the maximum torque capability in whole speed range with good dynamic performance. The proposed solution preserves the simplicity of tuning of the regulators. Furthermore, in order to validate the effectiveness of presented solution, it is assessed in terms of performance and complexity and compared to two other algorithm presented in literature. The feasibility of the proposed algorithm is also tested on induction motor drive fed by a matrix converter. Another important research area is connected to the development of technology for vehicular applications. In this field the dynamic performances and the low power consumption is one of most important goals for an effective algorithm. Towards this direction, a control scheme for induction motor that integrates within a coherent solution some of the features that are commonly required to an electric vehicle drive is presented. The main features of the proposed control scheme are the capability to exploit the maximum torque in the whole speed range, a weak dependence on the motor parameters, a good robustness against the variations of the dc-link voltage and, whenever possible, the maximum efficiency. The second part of this dissertation is dedicated to the multi-phase systems. This technology, in fact, is characterized by a number of issues worthy of investigation that make it competitive with other technologies already on the market. Multiphase systems, allow to redistribute power at a higher number of phases, thus making possible the construction of electronic converters which otherwise would be very difficult to achieve due to the limits of present power electronics. Multiphase drives have an intrinsic reliability given by the possibility that a fault of a phase, caused by the possible failure of a component of the converter, can be solved without inefficiency of the machine or application of a pulsating torque. The control of the magnetic field spatial harmonics in the air-gap with order higher than one allows to reduce torque noise and to obtain high torque density motor and multi-motor applications. In one of the next chapters a control scheme able to increase the motor torque by adding a third harmonic component to the air-gap magnetic field will be presented. Above the base speed the control system reduces the motor flux in such a way to ensure the maximum torque capability. The presented analysis considers the drive constrains and shows how these limits modify the motor performance. The multi-motor applications are described by a well-defined number of multiphase machines, having series connected stator windings, with an opportune permutation of the phases these machines can be independently controlled with a single multi-phase inverter. In this dissertation this solution will be presented and an electric drive consisting of two five-phase PM tubular actuators fed by a single five-phase inverter will be presented. Finally the modulation strategies for a multi-phase inverter will be illustrated. The problem of the space vector modulation of multiphase inverters with an odd number of phases is solved in different way. An algorithmic approach and a look-up table solution will be proposed. The inverter output voltage capability will be investigated, showing that the proposed modulation strategy is able to fully exploit the dc input voltage either in sinusoidal or non-sinusoidal operating conditions. All this aspects are considered in the next chapters. In particular, Chapter 1 summarizes the mathematical model of induction motor. The Chapter 2 is a brief state of art on three-phase inverter. Chapter 3 proposes a stator flux vector control for a three- phase induction machine and compares this solution with two other algorithms presented in literature. Furthermore, in the same chapter, a complete electric drive based on matrix converter is presented. In Chapter 4 a control strategy suitable for electric vehicles is illustrated. Chapter 5 describes the mathematical model of multi-phase induction machines whereas chapter 6 analyzes the multi-phase inverter and its modulation strategies. Chapter 7 discusses the minimization of the power losses in IGBT multi-phase inverters with carrier-based pulse width modulation. In Chapter 8 an extended stator flux vector control for a seven-phase induction motor is presented. Chapter 9 concerns the high torque density applications and in Chapter 10 different fault tolerant control strategies are analyzed. Finally, the last chapter presents a positioning multi-motor drive consisting of two PM tubular five-phase actuators fed by a single five-phase inverter.

Optimization of the Integrated Guidance and Control for a Dual Aerodynamic Control Missile

Las futuras misiones para misiles aire-aire operando dentro de la atm��sfera requieren la interceptaci��n de blancos a mayores velocidades y m��s maniobrables, incluyendo los esperados veh��culos a��reos de combate no tripulados. La intercepci��n tiene que lograrse desde cualquier ��ngulo de lanzamiento. Una de las principales discusiones en la tecnolog��a de misiles en la actualidad es c��mo satisfacer estos nuevos requisitos incrementando la capacidad de maniobra del misil y en paralelo, a trav��s de mejoras en los m��todos de guiado y control modernos. Esta Tesis aborda estos dos objetivos simult��neamente, al proponer un dise��o integrando el guiado y el control de vuelo (autopiloto) y aplicarlo a misiles con control aerodin��mico simult��neo en canard y cola. Un primer avance de los resultados obtenidos ha sido publicado recientemente en el Journal of Aerospace Engineering, en Abril de 2015, [Ibarrondo y Sanz-Aranguez, 2015]. El valor del dise��o integrado obtenido es que permite al misil cumplir con los requisitos operacionales mencionados empleando ��nicamente control aerodin��mico. El dise��o propuesto se compara favorablemente con esquemas m��s tradicionales, consiguiendo menores distancias de paso al blanco y necesitando de menores esfuerzos de control incluso en presencia de ruidos. En esta Tesis se demostrar�� c��mo la introducci��n del doble mando, donde tanto el canard como las aletas de cola son m��viles, puede mejorar las actuaciones de un misil existente. Comparado con un misil con control en cola, el doble control requiere s��lo introducir dos servos adicionales para accionar los canards tambi��n en gui��ada y cabeceo. La secci��n de cola ser�� responsable de controlar el misil en balanceo mediante deflexiones diferenciales de los controles. En el caso del doble mando, la complicaci��n a��adida es que los v��rtices desprendidos de los canards se propagan corriente abajo y pueden incidir sobre las superficies de cola, alterando sus caracter��sticas de control. Como un primer aporte, se ha desarrollado un modelo anal��tico completo para la aerodin��mica no lineal de un misil con doble control, incluyendo la caracterizaci��n de este efecto de acoplamiento aerodin��mico. Hay dos modos de funcionamiento en picado y gui��ada para un misil de doble mando: ���desviaci��n��� y ���opuesto���. En modo ���desviaci��n���, los controles act��an en la misma direcci��n, generando un cambio inmediato en la sustentaci��n y produciendo un movimiento de translaci��n en el misil. La respuesta es r��pida, pero en el modo ���desviaci��n��� los misiles con doble control pueden tener dificultades para alcanzar grandes ��ngulos de ataque y altas aceleraciones laterales. Cuando los controles act��an en direcciones opuestas, el misil rota y el ��ngulo de ataque del fuselaje se incrementa para generar mayores aceleraciones en estado estacionario, aunque el tiempo de respuesta es mayor. Con el modelo aerodin��mico completo, es posible obtener una parametrizaci��n dependiente de los estados de la din��mica de corto periodo del misil. Debido al efecto de acoplamiento entre los controles, la respuesta en bucle abierto no depende linealmente de los controles. El autopiloto se optimiza para obtener la maniobra requerida por la ley de guiado sin exceder ninguno de los l��mites aerodin��micos o mec��nicos del misil. Una segunda contribuci��n de la tesis es el desarrollo de un autopiloto con m��ltiples entradas de control y que integra la aerodin��mica no lineal, controlando los tres canales de picado, gui��ada y cabeceo de forma simult��nea. Las ganancias del autopiloto dependen de los estados del misil y se calculan a cada paso de integraci��n mediante la resoluci��n de una ecuaci��n de Riccati de orden 21x21. Las ganancias obtenidas son sub-��ptimas, debido a que una soluci��n completa de la ecuaci��n de Hamilton-Jacobi-Bellman no puede obtenerse de manera pr��ctica, y se asumen ciertas simplificaciones. Se incorpora asimismo un mecanismo que permite acelerar la respuesta en caso necesario. Como parte del autopiloto, se define una estrategia para repartir el esfuerzo de control entre el canard y la cola. Esto se consigue mediante un controlador aumentado situado antes del bucle de optimizaci��n, que minimiza el esfuerzo total de control para maniobrar. Esta ley de alimentaci��n directa mantiene al misil cerca de sus condiciones de equilibrio, garantizando una respuesta transitoria adecuada. El controlador no lineal elimina la respuesta de fase no-m��nima caracter��stica de la cola. En esta Tesis se consideran dos dise��os para el guiado y control, el control en Doble-Lazo y el control Integrado. En la aproximaci��n de Doble-Lazo, el autopiloto se sit��a dentro de un bucle interior y se dise��a independientemente del guiado, que conforma el bucle m��s exterior del control. Esta estructura asume que existe separaci��n espectral entre los dos, esto es, que los tiempos de respuesta del autopiloto son mucho mayores que los tiempos caracter��sticos del guiado. En el estudio se combina el autopiloto desarrollado con una ley de guiado ��ptimo. Los resultados obtenidos demuestran que se consiguen aumentos muy importantes en las actuaciones frente a misiles con control canard o control en cola, y que la interceptaci��n, cuando se lanza cerca del curso de colisi��n, se consigue desde cualquier ��ngulo alrededor del blanco. Para el misil de doble mando, la estrategia ��ptima resulta en utilizar el modo de control opuesto en la aproximaci��n al blanco y utilizar el modo de desviaci��n justo antes del impacto. Sin embargo la l��gica de doble bucle no consigue el impacto cuando hay desviaciones importantes con respecto al curso de colisi��n. Una de las razones es que parte de la demanda de guiado se pierde, ya que el misil solo es capaz de modificar su aceleraci��n lateral, y no tiene control sobre su aceleraci��n axial, a no ser que incorpore un motor de empuje regulable. La hip��tesis de separaci��n mencionada, y que constituye la base del Doble-Bucle, puede no ser aplicable cuando la din��mica del misil es muy alta en las proximidades del blanco. Si se combinan el guiado y el autopiloto en un ��nico bucle, la informaci��n de los estados del misil est�� disponible para el c��lculo de la ley de guiado, y puede calcularse la estrategia optima de guiado considerando las capacidades y la actitud del misil. Una tercera contribuci��n de la Tesis es la resoluci��n de este segundo dise��o, la integraci��n no lineal del guiado y del autopiloto (IGA) para el misil de doble control. Aproximaciones anteriores en la literatura han planteado este sistema en ejes cuerpo, resultando en un sistema muy inestable debido al bajo amortiguamiento del misil en cabeceo y gui��ada. Las simplificaciones que se tomaron tambi��n causan que el misil se deslice alrededor del blanco y no consiga la intercepci��n. En nuestra aproximaci��n el problema se plantea en ejes inerciales y se recurre a la din��mica de los cuaterniones, eliminado estos inconvenientes. No se limita a la din��mica de corto periodo del misil, porque se construye incluyendo de modo expl��cito la velocidad dentro del bucle de optimizaci��n. La formulaci��n resultante en el IGA es independiente de la maniobra del blanco, que sin embargo se ha de incluir en el c��lculo del modelo en Doble-bucle. Un t��pico inconveniente de los sistemas integrados con controlador proporcional, es el problema de las escalas. Los errores de guiado dominan sobre los errores de posici��n del misil y saturan el controlador, provocando la p��rdida del misil. Este problema se ha tratado aqu�� con un controlador aumentado previo al bucle de optimizaci��n, que define un estado de equilibrio local para el sistema integrado, que pasa a actuar como un regulador. Los criterios de actuaciones para el IGA son los mismos que para el sistema de Doble-Bucle. Sin embargo el problema matem��tico resultante es muy complejo. El problema ��ptimo para tiempo finito resulta en una ecuaci��n diferencial de Riccati con condiciones terminales, que no puede resolverse. Mediante un cambio de variable y la introducci��n de una matriz de transici��n, este problema se transforma en una ecuaci��n diferencial de Lyapunov que puede resolverse mediante m��todos num��ricos. La soluci��n resultante solo es aplicable en un entorno cercano del blanco. Cuando la distancia entre misil y blanco es mayor, se desarrolla una soluci��n aproximada basada en la soluci��n de una ecuaci��n algebraica de Riccati para cada paso de integraci��n. Los resultados que se han obtenido demuestran, a trav��s de an��lisis num��ricos en distintos escenarios, que la soluci��n integrada es mejor que el sistema de Doble-Bucle. Las trayectorias resultantes son muy distintas. El IGA preserva el guiado del misil y consigue maximizar el uso de la propulsi��n, consiguiendo la interceptaci��n del blanco en menores tiempos de vuelo. El sistema es capaz de lograr el impacto donde el Doble-Bucle falla, y adem��s requiere un orden menos de magnitud en la cantidad de c��lculos necesarios. El efecto de los ruidos radar, datos discretos y errores del radomo se investigan. El IGA es m��s robusto, resultando menos afectado por perturbaciones que el Doble- Bucle, especialmente porque el n��cleo de optimizaci��n en el IGA es independiente de la maniobra del blanco. La estimaci��n de la maniobra del blanco es siempre imprecisa y contaminada por ruido, y degrada la precisi��n de la soluci��n de Doble-Bucle. Finalmente, como una cuarta contribuci��n, se demuestra que el misil con guiado IGA es capaz de realizar una maniobra de defensa contra un blanco que ataque por su cola, s��lo con control aerodin��mico. Las trayectorias estudiadas consideran una fase pre-programada de alta velocidad de giro, manteniendo siempre el misil dentro de su envuelta de vuelo. Este procedimiento no necesita recurrir a soluciones t��cnicamente m��s complejas como el control vectorial del empuje o control por chorro para ejecutar esta maniobra. En todas las demostraciones matem��ticas se utiliza el producto de Kronecker como una herramienta practica para manejar las parametrizaciones dependientes de variables, que resultan en matrices de grandes dimensiones. ABSTRACT Future missions for air to air endo-atmospheric missiles require the interception of targets with higher speeds and more maneuverable, including forthcoming unmanned supersonic combat vehicles. The interception will need to be achieved from any angle and off-boresight launch conditions. One of the most significant discussions in missile technology today is how to satisfy these new operational requirements by increasing missile maneuvering capabilities and in parallel, through the development of more advanced guidance and control methods. This Thesis addresses these two objectives by proposing a novel optimal integrated guidance and autopilot design scheme, applicable to more maneuverable missiles with forward and rearward aerodynamic controls. A first insight of these results have been recently published in the Journal of Aerospace Engineering in April 2015, [Ibarrondo and Sanz-Ar��nguez, 2015]. The value of this integrated solution is that it allows the missile to comply with the aforementioned requirements only by applying aerodynamic control. The proposed design is compared against more traditional guidance and control approaches with positive results, achieving reduced control efforts and lower miss distances with the integrated logic even in the presence of noises. In this Thesis it will be demonstrated how the dual control missile, where canard and tail fins are both movable, can enhance the capabilities of an existing missile airframe. Compared to a tail missile, dual control only requires two additional servos to actuate the canards in pitch and yaw. The tail section will be responsible to maintain the missile stabilized in roll, like in a classic tail missile. The additional complexity is that the vortices shed from the canard propagate downstream where they interact with the tail surfaces, altering the tail expected control characteristics. These aerodynamic phenomena must be properly described, as a preliminary step, with high enough precision for advanced guidance and control studies. As a first contribution we have developed a full analytical model of the nonlinear aerodynamics of a missile with dual control, including the characterization of this cross-control coupling effect. This development has been produced from a theoretical model validated with reliable practical data obtained from wind tunnel experiments available in the scientific literature, complement with computer fluid dynamics and semi-experimental methods. There are two modes of operating a missile with forward and rear controls, ���divert��� and ���opposite��� modes. In divert mode, controls are deflected in the same direction, generating an increment in direct lift and missile translation. Response is fast, but in this mode, dual control missiles may have difficulties in achieving large angles of attack and high level of lateral accelerations. When controls are deflected in opposite directions (opposite mode) the missile airframe rotates and the body angle of attack is increased to generate greater accelerations in steady-state, although the response time is larger. With the aero-model, a state dependent parametrization of the dual control missile short term dynamics can be obtained. Due to the cross-coupling effect, the open loop dynamics for the dual control missile is not linearly dependent of the fin positions. The short term missile dynamics are blended with the servo system to obtain an extended autopilot model, where the response is linear with the control fins turning rates, that will be the control variables. The flight control loop is optimized to achieve the maneuver required by the guidance law without exceeding any of the missile aerodynamic or mechanical limitations. The specific aero-limitations and relevant performance indicators for the dual control are set as part of the analysis. A second contribution of this Thesis is the development of a step-tracking multi-input autopilot that integrates non-linear aerodynamics. The designed dual control missile autopilot is a full three dimensional autopilot, where roll, pitch and yaw are integrated, calculating command inputs simultaneously. The autopilot control gains are state dependent, and calculated at each integration step solving a matrix Riccati equation of order 21x21. The resulting gains are sub-optimal as a full solution for the Hamilton-Jacobi-Bellman equation cannot be resolved in practical terms and some simplifications are taken. Acceleration mechanisms with an ��-shift is incorporated in the design. As part of the autopilot, a strategy is defined for proper allocation of control effort between canard and tail channels. This is achieved with an augmented feed forward controller that minimizes the total control effort of the missile to maneuver. The feedforward law also maintains the missile near trim conditions, obtaining a well manner response of the missile. The nonlinear controller proves to eliminate the non-minimum phase effect of the tail. Two guidance and control designs have been considered in this Thesis: the Two- Loop and the Integrated approaches. In the Two-Loop approach, the autopilot is placed in an inner loop and designed separately from an outer guidance loop. This structure assumes that spectral separation holds, meaning that the autopilot response times are much higher than the guidance command updates. The developed nonlinear autopilot is linked in the study to an optimal guidance law. Simulations are carried on launching close to collision course against supersonic and highly maneuver targets. Results demonstrate a large boost in performance provided by the dual control versus more traditional canard and tail missiles, where interception with the dual control close to collision course is achieved form 365deg all around the target. It is shown that for the dual control missile the optimal flight strategy results in using opposite control in its approach to target and quick corrections with divert just before impact. However the Two-Loop logic fails to achieve target interception when there are large deviations initially from collision course. One of the reasons is that part of the guidance command is not followed, because the missile is not able to control its axial acceleration without a throttleable engine. Also the separation hypothesis may not be applicable for a high dynamic vehicle like a dual control missile approaching a maneuvering target. If the guidance and autopilot are combined into a single loop, the guidance law will have information of the missile states and could calculate the most optimal approach to the target considering the actual capabilities and attitude of the missile. A third contribution of this Thesis is the resolution of the mentioned second design, the non-linear integrated guidance and autopilot (IGA) problem for the dual control missile. Previous approaches in the literature have posed the problem in body axes, resulting in high unstable behavior due to the low damping of the missile, and have also caused the missile to slide around the target and not actually hitting it. The IGA system is posed here in inertial axes and quaternion dynamics, eliminating these inconveniences. It is not restricted to the missile short term dynamic, and we have explicitly included the missile speed as a state variable. The IGA formulation is also independent of the target maneuver model that is explicitly included in the Two-loop optimal guidance law model. A typical problem of the integrated systems with a proportional control law is the problem of scales. The guidance errors are larger than missile state errors during most of the flight and result in high gains, control saturation and loss of control. It has been addressed here with an integrated feedforward controller that defines a local equilibrium state at each flight point and the controller acts as a regulator to minimize the IGA states excursions versus the defined feedforward state. The performance criteria for the IGA are the same as in the Two-Loop case. However the resulting optimization problem is mathematically very complex. The optimal problem in a finite-time horizon results in an irresoluble state dependent differential Riccati equation with terminal conditions. With a change of variable and the introduction of a transition matrix, the equation is transformed into a time differential Lyapunov equation that can be solved with known numerical methods in real time. This solution results range limited, and applicable when the missile is in a close neighborhood of the target. For larger ranges, an approximate solution is used, obtained from solution of an algebraic matrix Riccati equation at each integration step. The results obtained show, by mean of several comparative numerical tests in diverse homing scenarios, than the integrated approach is a better solution that the Two- Loop scheme. Trajectories obtained are very different in the two cases. The IGA fully preserves the guidance command and it is able to maximize the utilization of the missile propulsion system, achieving interception with lower miss distances and in lower flight times. The IGA can achieve interception against off-boresight targets where the Two- Loop was not able to success. As an additional advantage, the IGA also requires one order of magnitude less calculations than the Two-Loop solution. The effects of radar noises, discrete radar data and radome errors are investigated. IGA solution is robust, and less affected by radar than the Two-Loop, especially because the target maneuvers are not part of the IGA core optimization loop. Estimation of target acceleration is always imprecise and noisy and degrade the performance of the two-Loop solution. The IGA trajectories are such that minimize the impact of radome errors in the guidance loop. Finally, as a fourth contribution, it is demonstrated that the missile with IGA guidance is capable of performing a defense against attacks from its rear hemisphere, as a tail attack, only with aerodynamic control. The studied trajectories have a preprogrammed high rate turn maneuver, maintaining the missile within its controllable envelope. This solution does not recur to more complex features in service today, like vector control of the missile thrust or side thrusters. In all the mathematical treatments and demonstrations, the Kronecker product has been introduced as a practical tool to handle the state dependent parametrizations that have resulted in very high order matrix equations.

California vector views.

Mode of access: Internet.

Facts about mosquito control and West Nile virus.

A collection of articles about mosquito control and West Nile virus that have been bound into one volume.

Developing a new SVPWM control strategy for open-winding brushless doubly fed reluctance generators

In this paper, a new open-winding control strategy is proposed for a brushless doubly fed reluctance generator (BDFRG) used for stand-alone wind turbine or ship generators. The BDFRG is characterized with two windings on the stator: a power winding and a control winding. The control winding is fed with dual two-level three-phase converters, and a vector control scheme based on space vector pulsewidth modulation is designed. Compared with traditional three-level inverter systems, the dc-link voltage and the voltage rating of power devices in the proposed system are reduced by 50% while still greatly improving the reliability, redundancy, and fault tolerance of the proposed system by increasing the switching modes. Its performance is evaluated by simulation in MATLAB/Simulink and an experimental study on a 42-kW prototype machine.

Perspectives of vaccination in Chagas disease revisited

The perspectives for a Chagas Disease vaccine 30 years ago and today are compared. Antigens and adjuvants have improved, but logistic problems remain the same. Sterilizing vaccines have not been produced and animal models for chronic Chagas have not been developed. Vector control has been successful and Chagas incidence has come to a halt. We do not have a population candidate to vaccination now in Brazil. And if we had, we would not know how to evaluate the success of vaccination in a short time period. A vaccine may not seem important at the moment. However, scientific reasons and incertitudes about the future recommend that a search for a vaccine be continued.

Monitoramento da suscetibilidade de popula����es de Triatoma sordida St��l, 1859 (Hemiptera: Reduviidae) ao inseticida deltametrina, na regi��o Centro-Oeste do Brasil

INTRODU����O: Popula����es de Triatoma sordida St��l, 1859 foram investigadas quanto �� suscetibilidade �� deltametrina. M��TODOS: An��lise por meio de bioensaios por aplica����o t��pica em 11 popula����es de T. sordida procedentes dos Estados de Goi��s, Mato Grosso e Mato Grosso do Sul. RESULTADOS: As estimativas de DL50 e RR50 demonstraram elevados n��veis de suscetibilidade (DL50 < 1 e RR50 < 2). Entretanto, as an��lises do coeficiente angular da curva dose resposta revelaram que as popula����es de triatom��neos dos munic��pios de Firmin��polis/GO, Posse/GO, Poxor��u/MT, Douradina/MS e Aparecida do Taboado/MS apresentam maiores probabilidades de evolu����o de resist��ncia, portanto, mais prop��cias a tolerar o tratamento com deltametrina. CONCLUS��ES: Detectaram-se pequenas altera����es de suscetibilidade e baixos n��veis de resist��ncia, por��m as altera����es temporais de suscetibilidade dever��o ser continuamente monitoradas, a fim de nortear adequadamente as a����es de controle dos vetores da DC.

Gerenciamento participativo em sa��de do trabalhador: uma experi��ncia na atividade de controle de vetores

Este artigo apresenta a experi��ncia de implanta����o de um sistema de gest��o em Sa��de do Trabalhador implantado na Superintendencia de Controle de Endemias (SUCEN), no per��odo de 1998 a 2002, que operava na atividade de controle qu��mico de vetores no Estado de S��o Paulo. OBJETIVO: Descrever o sistema de gest��o participativa, as a����es desenvolvidas e os principais resultados alcan��ados. M��TODO: Relato da experi��ncia vivenciada pela equipe usando abordagem qualitativa, an��lise de documentos e apresenta����o de dados quantitativos. RESULTADOS: Foram eleitas 11 Comiss��es de Sa��de e Trabalho (COMSAT's) que em conjunto com a equipe t��cnica iniciaram a identifica����o dos riscos e de propostas para preven����o e controle dos riscos no trabalho. O mapeamento de riscos resultou em 650 recomenda����es, 45,7% das quais foram executadas. Foram identificadas como doen��as relacionadas ao trabalho: rea����es al��rgicas aos pesticidas, les��es por esfor��os repetitivos, dist��rbios auditivos e patologias de coluna vertebral. Participaram dos cursos b��sicos de sa��de do trabalhador 1.003 servidores (76,3% do total de servidores), sendo que 90,8% dos participantes os consideraram ��timos ou bons. CONCLUS��ES: O sistema de gerenciamento participativo coloca em pr��tica os princ��pios de gest��o democr��tica do Sistema ��nico de Sa��de (SUS); incorpora, por meio do mapeamento de riscos, o saber do trabalhador; inclui os trabalhadores como sujeitos do processo de negocia����o e mudan��as; pratica o direito �� informa����o. As COMSAT's revelaram-se espa��os adequados para a negocia����o das melhorias nas condi����es de trabalho. A aprova����o do sistema de gest��o culminou na valida����o legal por meio de um acordo tripartite assinado em mar��o de 2002.

Density and survival rate of Culex quinquefasciatus at Parque Ecol��gico do Tiet��, S��o Paulo, Brazil

Parity rate, gonotrophic cycle length, and density of a Culex quinquefasciatus female population was estimated at the Parque Ecol��gico do Tiet�� (PET), S��o Paulo, Brazil. Adult Cx. quinquefasciatus females were collected from vegetation along the edges of a polluted drainage canal with the use of a battery-powered backpack aspirator from September to November 2005 and from February to April 2006. We examined 255 Cx. quinquefasciatus ovaries to establish the parity rate of 0.22 and determined the gonotrophic cycle length under laboratory conditions to be 3 and 4 days. From these data, we calculated the Cx. quinquefasciatus survival rate to be 0.60 and 0.68 per day. Density of the Cx. quinquefasciatus female (5.71 females per m2) was estimated based on a population size of 28,810 individuals divided by the sampled area of 5,040 m2. Results of all experiments indicate medium survivorship and high density of the Cx. quinquefasciatus female population. This species is epidemiologically relevant in the PET area and should be a target of the vector control program of S��o Paulo municipality

A proteomic approach to identifying proteins differentially expressed in conidia and mycelium of the entomopathogenic fungus Metarhizium acridum

Metarhizium spp. is an important worldwide group of entomopathogenic fungi used as an interesting alternative to chemical insecticides in programs of agricultural pest and disease vector control. Metarhizium conidia are important in fungal propagation and also are responsible for host infection. Despite their importance, several aspects of conidial biology, including their proteome, are still unknown. We have established conidial and mycelial proteome reference maps for Metarhizium acridum using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF MS). In all, 1130 +/- 102 and 1200 +/- 97 protein spots were detected in ungerminated conidia and fast-growing mycelia, respectively. Comparison of the two protein-expression profiles reveled that only 35 % of the protein spots were common to both developmental stages. Out of 94 2-DE protein spots (65 from conidia, 25 from mycelia and two common to both) analyzed using mass spectrometry, seven proteins from conidia, 15 from mycelia and one common to both stages were identified. The identified protein spots exclusive to conidia contained sequences similar to known fungal stress-protector proteins (such as heat shock proteins (HSP) and 6-phosphogluconate dehydrogenase) plus the fungal allergen Alt a 7, actin and the enzyme cobalamin-independent methionine synthase. The identified protein spots exclusive to mycelia included proteins involved in several cell housekeeping biological processes. Three proteins (HSP 90, 6-phosphogluconate dehydrogenase and allergen Alt a 7) were present in spots in conidial and mycelial gels, but they differed in their locations on the two gels. (c) 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Dog culling and replacement in an area endemic for visceral leishmaniasis in Brazil

Measures employed to control visceral leishmaniasis in Brazil have focused on vector control by residual insecticide spraying and diagnosis of infection with elimination of positive dogs. We describe dog culling and replacement in a Brazilian endemic area (the Alvorada District, Aracatuba, SP) in order to better understand dog population dynamics when elimination of the dog reservoir is adopted as the main control measure. From August 2002 to July 2004, 60.9% of the estimated dog population for the area was culled with a mean age of 34 months old. The presence of anti-Leishmania sp. antibodies was recorded for only 26.7% of the euthanized canines. Replacement was observed in 38.8% of the cases, some of them by 2 or more dogs and in a mean time of 4 months. Dogs were replaced mostly by puppies of both sexes with a mean age of 6.8 months. From August 2002 to April 2005 we were able to follow-up 116 of these dogs, during a mean time of 8.7 months. Canine visceral leishmaniasis seropositivity by ELISA was observed in 42.2% of the followed dogs, 30.6% of which were already positive at the first evaluation. By the end of the follow-up period 37% of the dogs were submitted to euthanasia, with a mean age of 18.3 months. In the studied CVL endemic area of Brazil, euthanasia and the subsequent replacement ratio were high, increasing the dog population turnover and leading to a younger population that might be more susceptible to a variety of other infectious diseases in addition to CVL. Dog culling as a control strategy for VL should be reassessed. (C) 2008 Elsevier B.V. All rights reserved.

Chagas disease

Chagas disease is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi, and was discovered in 1909. The disease affects about 8 million people in Latin America, of whom 30-40% either have or will develop cardiomyopathy, digestive megasyndromes, or both. In the past three decades, the control and management of Chagas disease has undergone several improvements. Large-scale vector control programmes and screening of blood donors have reduced disease incidence and prevalence. Although more effective trypanocidal drugs are needed, treatment with benznidazole (or nifurtimox) is reasonably safe and effective, and is now recommended for a widened range of patients. Improved models for risk stratification are available, and certain guided treatments could halt or reverse disease progression. By contrast, some challenges remain: Chagas disease is becoming an emerging health problem in non-endemic areas because of growing population movements; early detection and treatment of asymptomatic individuals are underused; and the potential benefits of novel therapies (eg, implantable cardioverter defibrillators) need assessment in prospective randomised trials.

Intra-population plasticity of Anopheles darlingi's (Diptera, Culicidae) biting activity patterns in the state of Amap��, Brazil

OBJECTIVE: To assess the variation in Anopheles darlingi's biting activity compared to An. marajoara in the same locality and to biting activity data from other regions. METHODS: Using human bait, eight observations of the biting activity of An. darlingi and An. marajoara were carried out during 1999 and 2000 in the municipality of S��o Raimundo do Pirativa, state of Amap��, Brazil. Each observation consisted of three consecutive 13-hour collections, close to full moon. There were shifts of collectors in the observation points and nocturnal periods. RESULTS: An. darlingi revealed considerable plasticity of biting activity in contrast to An. marajoara, which showed well-defined crepuscular biting peaks. No significant correlation between density and biting activity was found, but a significant correlation existed between time and proportional crepuscular activity, indicating underlying ecological processes not yet understood. Two of the four available data sets having multiple observations at one locality showed considerable plasticity of this species' biting patterns as well. CONCLUSION: Intra-population variation of biting activity can be as significant as inter-population variation. Some implications in malaria vector control and specific studies are also discussed.

Controlo directo de bin��rio de uma m��quina ass��ncrona trif��sica

Disserta����o para obten����o do grau de Mestre em Engenharia Electrot��cnica Ramo de Automa����o e Electr��nica Industrial