Modelagem e controle avançado não-linear multivariável por lógica nebulosa : aplicação para um processo de copolimerização

A obtenção de um modelo matemático confiável de um dado processo é um pré-requisito fundamental para o projeto de controladores. Contudo, particularmente para sistemas poliméricos que são intrinsecamente caracterizados por dinâmicas complexas, o delineamento de uma aproximação a partir dos primeiros princípios é uma tarefa bastante árdua e, por vezes, não realizável. Logo, representações matemáticas mais simples, porém reprodutivas das principais peculiaridades do sistema, são bem-vindas. Assim sendo, este trabalho apresenta o desenvolvimento e a implementação de dois esquemas de controle preditivo não-linear multivariável baseado em modelo nebuloso para um processo de copolimerização. Modelos MISO (Multi-Input/Single-Output) lineares e exponenciais são construídos a partir da lógica nebulosa, combinados e aplicados para simulação e predição on-line. Os desempenhos das estruturas de controle propostas foram comparados ao DMC (Dynamic Matrix Control) e a um típico NMPC (Nonlinear Model-based Predictive Control) para o problema servo. Os resultados obtidos comprovaram a eficácia das configurações projetadas

Multivariable nonlinear advanced control of copolymerization processes

A reliable multivariable model of a process is a fundamental prerequisite for the design of an efficient control strategy. Though, such a model is often very hard to obtain via a first-principles approach. The development of two fuzzy model-based multivariable nonlinear predictive control schemes and their implementation on a copolymerization process are described in this paper. Multi-input/single-output models are developed using fuzzy logic and combined to form a parallel system model for simulation and online prediction. The behavior of the outlined controllers were compared to the dynamic matrix control (DMC) and to a typical nonlinear model-based predictive control (NMPC) for regulatory problem and the obtained results showed the effectiveness of the proposed structures

Risk indicators for oral ulcers among people living with HIV during the first wave of the pandemic: A cross-sectional study

Background: Little is currently known about HIV-related parameters that may increase the risk for oral ulcers during the COVID-19 pandemic. This study aimed to overcome this gap in research by assessing the associations between HIV viral load, antiretroviral adherence profile, co-morbidity status, SARS-CoV-2 infection and oral ulcers among people living with HIV (PLHIV). Methods: This was a secondary analysis of data generated from 21,206 to 18 years and above, recruited from 152 countries through an online survey between July and December 2020. Data were extracted for 874 people who reported living with HIV. The dependent variable was reporting having oral ulcer. The independent variables were the viral load, adherence to antiretroviral treatment and a history of SARS-CoV-2 infection. The confounding variables were age at last birthday and sex at birth. A multivariable logistic regression analysis was conducted to determine the associations between the dependent and independent variables after adjusting for the confounding variables. Results: Of the 874 participants, 99 (11.3%) reported having oral ulcers during the first wave of the COVID-19 pandemic. The odds of PLHIV having oral ulcers during the first wave of the COVID-19 pandemic was significantly higher for people who did not know their viral load than those who had undetectable viral load (AOR: 2.036; 95% CI: 1.204–3.443; p = 0.008); and people who did not adhere to the use of antiretroviral treatment than those who adhered (AOR: 4.113; 95% CI: 2.567–6.589; p < 0.001). Also, PLHIV who had SARS-CoV-2 infection had significantly higher odds of having oral ulcers than those who did not have the infection (AOR: 14.556; 95% CI: 4.500-47.078; p < 0.001). PLHIV who had co-morbidities had non-significantly higher odds of having oral ulcers than those without co-morbidities (AOR: 1.170; 95% CI: 0.656–2.085; p = 0.595). Conclusion: Oral ulcers may be an indicator of poor adherence to antiretroviral therapy and unsuppressed viral load among PLHIV. It may also be an indicator of SARS-CoV-2 infection and a signal to take prompt and critical care of affected individuals because of the risk for severe COVID-19 for these individuals.publishedVersio

Detección de Leucoptera sinuella (Reutti) (Lepidoptera: Lyonetiidae) en Chile, con la identificación de algunos parasitoides asociados

En marzo del 2015 el Servicio Agrícola y Ganadero (SAG), a través de actividades de vigilancia forestal, detectó por primera vez en Chile la presencia de Leucoptera sinuella (Reutti), atacando follaje de álamos (Populus spp., Salicaceae), en la comuna de Talagante (Región Metropolitana de Santiago). Actividades de prospección desarrolladas por el SAG han determinado que este microlepidóptero se encuentra distribuido en diversas comunas de las regiones de Valparaíso, Metropolitana de Santiago, Libertador General Bernardo O’Higgins, Maule, Ñuble y Biobío. Adicionalmente, fueron identificadas siete especies de microhimenópteros parasitoides asociados a L. sinuella, pertenecientes a las familias Eulophidae (6 especies) y Chalcididae (1 especie)

The prevalence of brucellosis and bovine tuberculosis in ruminants in Sidi Kacem Province, Morocco

Bovine tuberculosis (BTB) and brucellosis are major endemic zoonoses in ruminants in Morocco that impact on both animal and human health. This study presents an assessment of the epidemiological and socioeconomic burden of bacterial zoonoses in Sidi Kacem Province in Northern Morocco from a cross-sectional survey of 125 cattle and/or small ruminantowning households. In total, 1082 sheep and goats were examined from 81 households. The single intradermal comparative cervical test to screen for bovine tuberculosis was undertaken on 1194 cattle from 123 households and all cattle were blood sampled. Cattle and small ruminant sera were tested for brucellosis using the standard Rose Bengal Test (sRBT) and the modified Rose Bengal Test (mRBT). Bacteriology was performed on 21 milk samples obtained from cattle that were seropositive for brucellosis for isolation and phenotyping of circulating Brucella strains. Individual and herd prevalence for BTB in cattle of 20.4% (95% CI 18%-23%) and 57.7% (95% CI 48%-66%), respectively, were observed in this study. The prevalence of brucellosis in cattle at individual and herd level was 1.9% (95% CI 1.2%-2.8%) and 9% (95% CI 4.5%-1.5%), respectively. Brucella pathogens were isolated from three cattle milk samples and were identified as B. abortus using Bruceladder (R) multiplex PCR and B. abortus biovar 1 by classical phenotyping. All small ruminants were seronegative to sRBT, two were positive to mRBT. A higher risk of BTB and brucellosis was observed in cattle in intensive livestock systems, in imported and crossed breeds and in animals from larger herds (>15). The three risk factors were usually present in the same herds, leading to higher transmission risk and persistence of both zoonoses. These results highlight the importance of implementing control strategies for both BTB and brucellosis to reduce productivity losses and the risk of transmission to humans. Prioritising control for BTB and brucellosis in intensive livestock production systems is essential for human and animal health