Dual-Mode Based Sliding Mode Control Approach for Nonlinear Chemical Processes.

This paper synthesizes a new sliding mode controller (SMC) approach to enhance tracking and regulation tasks by following dual-mode concepts. The new control law consists of two distinct types of operation, using the combination of higher gain to large error signals (transient) and lower gain to small error signals (the region around the set point). The design is presented from a dual-mode (PD-PID) sliding surface operating in concert, fulfilling desired control objectives to ensure stability and performance. Therefore, a new controller was established, and we called it a dual-mode based SMC. The proposed controller is tested by computer simulations applied to two nonlinear processes, a continuous stirred-tank reactor (CSTR) and a mixing tank with a variable dead time. The results are compared with two different alternatives of SMC. In addition, the merits and drawbacks of the control schemes are analyzed using radial graphs, comparing the control methods with various performance measures for set points and disturbances changes. The ITSE (integral of time multiplied by the squared error), TVu (total variation of control effort) indices, Mp (maximum overshoot), and ts (settling time) were the indices used for performance analysis and comparisons.

Psychological Adjustment Profiles of LGBTQ+ Young Adults Residing with Their Parents during the COVID-19 Pandemic: An International Study.

The COVID-19 pandemic has been associated with poor mental health symptoms, particularly among vulnerable populations such as LGBTQ+ individuals. In the present study, we aimed to (i) identify different psychological adjustment profiles among LGBTQ+ young adults during the COVID-19 pandemic and compare LGBTQ+ young adults in relation to (ii) sociodemographic characteristics and COVID-19-related experiences and (iii) the internal and external protective resources associated with each adjustment profile. An online questionnaire was administered to 1699 LGBTQ+ young adults from six countries (Brazil, Chile, Italy, Portugal, Sweden, and the UK). A cluster analysis was conducted, and four profiles of psychological adjustment were identified: unchallenged, resilient, distressed, and at-risk. The at-risk cluster scored lowest in social support (particularly from family). The profiles of participants who experienced the highest levels of pandemic adversity (at-risk and resilient) comprised mostly South American participants, those under lockdown at the time of survey completion, those who self-identified as transgender and non-binary, and those with a plurisexual sexual orientation. Interventions should consider strategies to help young adults maintain support systems and reinforce the value of positive family relationships. Specific groups within the LGBTQ+ community that seem to be in a particularly vulnerable situation may need additional tailored support.

Mental health in the Chilean LGBT population in times of COVID-19 / Salud mental en población LGBT chilena en tiempos de la COVID-19

Abstract Introduction There are few reports on mental health among the lesbian, gay, bisexual, and transgender (LGBT) population in the context of COVID-19, especially in South America. Objective To describe the prevalence of symptoms associated with mental health disorders, as well as to analyze the risk of their occurrence, in different groups of the Chilean LGBT population in the context of COVID-19. Method A total of 1,181 LGBT people, ranged from 18 to 64 years participated in an online survey, using the Depression Anxiety Stress Scales-DASS-21. The central tendency measures were analyzed, then cut-off points were used to establish prevalence according to sex and sexual orientation. Finally, the probability of symptoms was analyzed using odds ratio. Results Lower levels of mental health were identified among the bisexual and other sexual orientations (pansexual, demisexual, asexual, etc.) population as compared with gays and lesbians, finding a greater presence of depressive symptoms (p = .000), anxious (p = .000) and related to stress (p<.001). Similarly, bisexual women are more likely to present symptoms associated with mental health disorders than men, as lesbians do, as compared with gays in the case of anxiety. Gays are at a higher risk of stress than lesbians. Discussion and conclusion Even though the pandemic affected the entire population, results give evidence of disparities among the various LGBT communities, showing the need to focus on preventive interventions and the implications of increased risk in bisexual population, particularly women, who are affected by various cross discriminations.

Resumen Introducción Existen pocos reportes sobre la salud mental en poblaciones de lesbianas, gays, bisexuales y transexuales (LGBT) en el contexto del COVID-19, especialmente en Sudamérica. Objetivo Describir la prevalencia de síntomas asociados a problemas de salud mental, así como analizar su riesgo de ocurrencia en diferentes grupos de población LGBT chilena en el contexto de la pandemia del COVID-19. Método Participaron en una encuesta en línea un total de 1,181 personas LGBT, con edades comprendidas entre los 18 y los 64 años, quienes completaron el cuestionario DASS-21 (del inglés Depression Anxiety Stress Scales). Primero se analizaron las medidas de tendencia central, luego se estableció la prevalencia según sexo y orientación sexual y finalmente se analizó la probabilidad de presentar síntomas mediante el odss ratio. Resultados Se identificaron menores niveles de salud mental en la población bisexual y otras orientaciones sexuales (pansexual, demisexual, asexual, etc.), en comparación con gays y lesbianas, debido a una mayor presencia de sintomatología depresiva (p = .000), ansiosa (p = .000) y vinculada al estrés (p<.001). Asimismo, las mujeres bisexuales fueron más propensas que los hombres a presentar síntomas asociados a trastornos de salud mental, al igual que las lesbianas, en comparación con los gays en el caso de la ansiedad. Los gays tienen un mayor riesgo de estrés que las lesbianas. Discusión y conclusión Aun cuando la pandemia afectó a toda la población, los resultados evidencian las disparidades entre las distintas comunidades LGBT, mostrando la necesidad de centrarse en las intervenciones preventivas y las implicaciones de un mayor riesgo en la población bisexual, especialmente en las mujeres, que se ven afectadas por diversas discriminaciones cruzadas.

Psychosocial Effects of the COVID-19 Pandemic and Mental Health among LGBTQ+ Young Adults: A Cross-Cultural Comparison across Six Nations.

Across the world, people have seen their lives interrupted by the COVID-19 pandemic. Using an online survey, we explored how the psychosocial effects of the pandemic affected the mental health of LGBTQ+ young adults who were confined with their parents during the lockdown period (N = 1,934), from six countries: Portugal, UK, Italy, Brazil, Chile, and Sweden. South American participants experienced more negative psychosocial effects of the pandemic. Depression and anxiety were higher among participants who were younger, not working, living in Europe and who reported feeling more emotionally affected by the pandemic, uncomfortable at home, or isolated from non-LGBTQ friends. Not attending higher education predicted depression while not being totally confined at home, residing habitually with parents, and fearing more future infection predicted anxiety. LGBTQ+ community groups, as well as health and educational services should remain particularly attentive to the needs of LGBTQ+ young adults during health crises.

Oral manifestations in a patient with a history of asymptomatic COVID-19: Case report.

The pandemic situation has led to public health measures that have forced patients with and without the SARS-CoV-2 virus to remain isolated and take steps to prevent the spread. Many of these patients have been unable to attend the control of medical-dental services, which in many cases complicates their situation. This study reports on the oral manifestations of an asymptomatic COVID-19 patient treated interdisciplinary by teleconsultation due to the sudden appearance of lesions in the oral mucosa. Lesions are diagnosed, therapeutic measures are taken, and improvement is shown. This case shows that the problems that arise in the oral mucosa in patients with suspected or confirmed SARS-CoV-2 infection can be monitored through interdisciplinary teleconsultation during the pandemic with the support of information technology currently available worldwide. It also decreases the risk of transmission of SARS-Cov-2 between patients and health professionals.