16 research outputs found
Detección de Aedes aegypti infectado con el virus dengue como un método complementario para aumentar la sensibilidad de la vigilancia: identificación de los serotipos 1, 2 y 4 por RT-PCR en Quintana Roo, México.
Detection of aedes aegypti mosquitoes infected with dengue virus as a complementary method for increasing the sensitivity of surveillance: identification of serotypes 1, 2, and 4 by rt-pcr in Quintana Roo, Mexico
Abstract. Sensitivity of monitoring Aedes aegypti (L.) populations was determined to identify the distribution of dengue virus (DENV) during epidemics in Quintana
Roo. From September to November 2012, we used a motorized aspirator to collect 2,144 female Ae. aegypti from 569 homes. These were grouped into 220 to use
semi-nested RT-PCR for DENV, and positive groups were analyzed individually. Five groups (2.27%) were positive for DENV. Individual analysis yielded eight
groups that tested positive, six with DENV-2, one DENV-1, and one DENV-4. The latter was not reported by the surveillance system that year. The mean number of female mosquitoes per household was 3.77 ± 5.71, and the rate of viral infection of Ae. aegypti was 0.4%. Most infected mosquitoes (49%) were concentrated in 10% of the houses. Monitoring Ae. aegypti infected with DENV has the potential to complement the current system of clinical and entomological surveillance
Fastest with No-Overshoot Velocity Control Design of a Two-Differential Robotic Formation
Proportional-delayed controllers design for LTI-systems a geometric approach
International audienceThis paper focuses on the design of non-fragile P-controllers for single-input-single-output (SISO) linear time-invariant (LTI) systems. The basis of this work is a geometric approach allowing to partitioning the parameter-space in regions with constant number of unstable roots. This methodology defines the hyperplanes separating the aforementioned regions and characterizes the way in which the number of unstable roots changes when crossing such a hyper-plane. The main contribution of the paper is that it provides an explicit tool to find non-fragile P-gains ensuring the stability of the LTI system under consideration. More precisely, in this work a simple geometric-based algorithm is derived in order to propose a non-fragile P-controller. Several numerical examples illustrate the e↵ectiveness of the proposed approach
A transparent bilateral control scheme for a local teleoperation system using proportional-delayed controllers
International audienceThis paper addresses the closed-loop stability analysis problem of a bilateral local teleoperation system in the presence of delays, with the purpose of maintaining a kinematic correspondence between a master and a slave device. The stability analysis is proposed as a general analysis in the controller's parameter-space under the assumption of two fixed delays, considering one due to the signal and communication processing and one defined as a design delay for the controller. Furthermore, a method for measuring the fragility of the controllers is also proposed. Finally, experimental results obtained from an experimental platform consisting of two Phantom Omni haptic devices and the Matlab-Simulink toolkit Phansim illustrate the performance of the proposed approach and the video of the experiments can be downloaded from the authors' dedicated website 1
Delay Margin in Controlling a Furuta Pendulum
International audienceThis paper focuses on the design of an LQR based control scheme for the stabilization of the Furuta Pendulum in its unstable equilibrium point at the upright position. More precisely, we are interested in characterizing the corresponding delay margin under the assumption that the feedback loop includes time-delay. The paper provides an explicit tool to compute the critical delay value in the state feedback loop and a delicate tuning to reach larger delay values. In order to illustrate the effectiveness of the proposed control scheme, some numerical results are presented
Closed-Loop Stability Analysis of Voltage Mode Buck Using a Proportional-Delayed Controller
International audienceThis paper focuses on the design of a P-δ controller for the stabilization of a buck DC/DC converter. The basis of this work is a geometric approach which allows to partition the parameters space into regions with constant number of unstable roots. The main contribution of the paper is that it provides an explicit tool to find P-δ gains ensuring the stability of the closed-loop system. In addition, the proposed methodology enables the design a non-fragile controller with a desired exponential decay rate σ. In order to illustrate the effectiveness of the proposed controller, some numerical examples are presented
Modeling and Control of an Interactive Tilt-rotor MAV for In-contact Cracks-sensing Operations
International audienc
Co-infection of Dengue, Zika and Chikungunya in a group of pregnant women from Tuxtla Gutiérrez, Chiapas: Preliminary data. 2019.
IntroductionDengue, Zika and Chikungunya are RNA Arboviruses present in some areas of Mexico, mainly in the endemic state of Chiapas that is characterized by presence of the vector that transmit them and an ecology that favors high transmission. According to the national epidemiological surveillance system, Dengue has intensified since 2018 and outbreaks continue in various states while for Zika and Chikungunya a decrease in cases has been reported in recent years. The main objective of this study was to determine the incidence of Dengue, Zika and Chikungunya infections during pregnancy in the state of Chiapas.Principal findingsThe presence of previous and current infections and coinfections diagnosed by molecular (RT-PCR) and immunological (ELISA for IgG determination) techniques indicates a wide circulation of viruses in asymptomatic people, specifically in pregnant women showing that silent infections in dry season contributes to the preservation of viruses.ConclusionsFrom 136 studied samples, 27.7% tested positive for DENV, 8% for ZIKV and 24.1% for CHIKV by RTPCR and the values of IgG in sera show that 83.9% were positive for IgG antibodies against DENV, 65% against ZIKV and 59.1% against CHIKV. Results demonstrated presence of ZIKV and CHIKV, not detected by the epidemiological surveillance system, so the importance of establishing proactive epidemiological systems more strict, especially because these infections in pregnant women can cause severe health problems for newborn children