Modified spectral conjugate gradient iterative scheme for unconstrained optimization problems with application on COVID-19 model

In this work, a new class of spectral conjugate gradient (CG) method is proposed for solving unconstrained optimization models. The search direction of the new method uses the ZPRP and JYJLL CG coefficients. The search direction satisfies the descent condition independent of the line search. The global convergence properties of the proposed method under the strong Wolfe line search are proved with some certain assumptions. Based on some test functions, numerical experiments are presented to show the proposed method's efficiency compared with other existing methods. The application of the proposed method for solving regression models of COVID-19 is provided. Mathematics subject classification: 65K10, 90C52, 90C26. Copyright © 2022 Novkaniza, Malik, Sulaiman and Aldila.

Measurement of Relative Efficiency Levels of Southeast Asian Countries in Dealing with the Covid-19 Pandemic Over One Year

Introduction: Handling the COVID-19 outbreak is one of the most novelties modern work is facing by many countries today. Massive outbreak needs countries efficacy and talent in creating new approaches. These approaches need to prevent the spread of the outbreak and increase the citizens' belief as the outbreak will damage the countries' functional capacity. Technical efficiency is used maximally to gain total control of the conditions. This study aims to measure the relative efficiency level of Southeast Asian countries in dealing with COVID-19 pandemic over one year. Methods: The relative efficiency level of the most successful countries in Southeast Asia in managing COVID-19 infection was determined using Frontier 4.1 through Stochastic Frontier Analysis (SFA) and Excel software. The technical efficiency of the SFA model is defined as the ratio of observed output to maximum feasible production. If the country's technical efficiency (TE) is greater than 80%, it is the most effective in Southeast Asia at managing COVID-19 infection, but if it is less than 80% or close to 0, it is inefficient. Results: This research aims at the COVID-19 epidemic in a Southeast Asian country, where the country with the highest technical efficiency score is the most efficient and indicates the country's ability to deal with the COVID-19 outbreak without any complications. Laos was ranked first (TE = 0.99901), with a technical efficiency score that was higher than that of most other Southeast Asian countries. Singapore comes in second position with a technical efficiency score of 0.99882. Brunei is in third place for COVID-19, with a technical efficiency score of 0.99870. Cambodia is in last place, with a score of 0.84675 for technical efficiency. Conclusion: Laos is the highest technical efficiency score among the southeast Asian countries. Various things that can lead to inefficiency include lack of awareness about standard operating procedures (SOP) among the causes of COVID-19 case infection in the workplace, and the community continues to increase. This condition may also be due to the lack of medication or vaccines to cure COVID-19. All communities around the world are expected to adopt standard operating procedures (SOP) such as wearing face masks, hand sanitizers, and social distance to curb the increasingly violent spread of COVID-19. © 2021 Tehran University of Medical Sciences.

Physical activity level and body mass index profile of the working-age population in palembang city

Physical activity levels have decreased during the Covid-19 pandemic because of the lockdown period and related social distancing measures. Although Indonesian government has gradually allowed people to do outdoor activities, there are still large-scale restrictions on doing activities in public places. Palembang is one of biggest cities in Indonesia, in which students and workers have been learning and working from home during the pandemic. The purpose of this study was to analyse the physical activity levels and body mass index (BMI) profiles of the working-age population in Palembang, Indonesia, during the COVID-19 pandemic. In total, 735 participants (M: 416;F: 319) with a minimum age of 15 (26.14±9.46) participated in this study. The method of this study was a survey using an online Short-Form of the International Physical Activity Questionnaire (IPAQ-SF) to assess physical activity and energy expenditure levels based on Metabolic Equivalents of Task (MET). The data was collected for 4 weeks in February 2021 by measuring the height and weight and by observing the physical activity behaviour of the participants through the survey. The results of the BMI calculation showed that almost half of the participants were a combination of underweight, overweight, and obese, while participants in the normal category included only slightly more than half. The results of the physical activity level showed that more than half of the participants were in the low and medium category, while participants in the high category included slightly fewer than 40%. Thus, the working-age population in Palembang City needs to increase their physical activity and maintain their nutritional intake to improve their BMI levels during the COVID-19 pandemic. © 2021, Editura Universitatii din Pitesti. All rights reserved.

A new hybrid conjugate gradient algorithm for optimization models and its application to regression analysis

The hybrid conjugate gradient (CG) method is among the efficient variants of CG method for solving optimization problems. This is due to their low memory requirements and nice convergence properties. In this paper, we present an efficient hybrid CG method for solving unconstrained optimization models and show that the method satisfies the sufficient descent condition. The global convergence prove of the proposed method would be established under inexact line search. Application of the proposed method to the famous statistical regression model describing the global outbreak of the novel COVID-19 is presented. The study parameterized the model using the weekly increase/decrease of recorded cases from December 30, 2019 to March 30, 2020. Preliminary numerical results on some unconstrained optimization problems show that the proposed method is efficient and promising. Furthermore, the proposed method produced a good regression equation for COVID-19 confirmed cases globally. © 2021 Institute of Advanced Engineering and Science. All rights reserved.

Evaluation of the airway viral load in acute sars-cov2 infection as a predictor of clinical outcome

Rationale: Throughout recent studies, data suggests high viral load in the plasma and nasopharynx of patients with severe SARS-CoV2 infection is associated with disease severity (mortality, length of hospitalization, and risk of intubation). Here, we evaluated whether viral load in the airway is associated with poor clinical outcomes in patients with SARS-CoV2. Methods: Lower airway samples in 148 patients from an academic center that were admitted to the ICU (dates: March 10th to May 10th, 2020) with severe respiratory failure requiring mechanical ventilation and underwent bronchoscopy for airway clearance and/or tracheostomy. Clinical outcome was defined as ≤ 28 Day mechanical ventilation vs. > 28 Day mechanical ventilation vs. death. Post-admission followup time was 232 [IQR 226-237] days. RNA was isolated in parallel using zymoBIOMICS™ DNA/RNA Miniprep Kit (Cat: R2002) as per manufacturer's instructions. Viral load was measured by quantitative real-time reverse transcription polymerase chain reaction (rRT -PCR) targeting the virus nucleocapsid (N) gene and an additional primer/probe set to detect the human RNase P gene (RP). Results: Among this bronchoscopy cohort, n=58 39% of the subjects were successfully extubated within 28 days of initiation of mechanical ventilation, n=56 38% required prolonged mechanical ventilation and n=34 23% died. We evaluated the viral load by rRT-PCR for SARSCoV2 N gene adjusted by human RP gene throughout the respiratory tract using supraglottic samples and bronchoalveolar lavage (BAL) samples obtained during bronchoscopy. Paired analysis of upper and lower airway samples shows that there is a subset of subjects (n=31, 21%) where there is greater viral load in the BAL than in the supraglottic area supporting topographical differences in viral replication (Fig 1A). BAL samples from subjects that died had higher viral load in their lower airways than patients that survived, even after adjusting for confounders such as age, gender, BMI and timing of sample collection (Fig 1B magenta dots (deceased) vs. yellow/green dots (alive)). Conclusions: Using samples obtained via bronchoscopy we identified that in a subset of subjects with acute SARS-CoV2 infection, the lower airways are the predominant site for viral replication. From our study, it is unclear if the higher viral load reflects host co-morbidies (e.g., diabetes or immunosuppression) or viral factors favoring higher replication. High viral load can be used as a predictor for disease severity upon hospital admission as viral load in the lower airways correlated with poor outcomes.

Evaluation of the lower airway microbiota in patients with severe sars-cov2

RATIONALE:Secondary infections with bacterial pathogens are thought to be responsible for poor outcomes in the 1918 Spanish and H1N1 pandemics. We postulate that poor prognosis in patients with SARS-CoV2 may be associated with uncontrollable viral replication, co-infection with a secondary pathogen, and over exuberant host immune response. We seek to evaluate whether there is an association between distinct features of the lower airway microbiota and poor clinical outcome in patients with SARS-CoV2. METHODS:We collected lower airway samples in 148 patients from NYU admitted between 3/10/2020 and 5/10/2020 with severe respiratory failure requiring mechanical ventilation and that underwent bronchoscopy for airway clearance and/or tracheostomy. Clinical outcome was defined as dead vs alive. DNA was isolated in parallel using zymoBIOMICS™ DNA/RNA Miniprep Kit (Cat: R2002) as per manufacturer's instructions. The V4 region of the 16S rRNA gene marker was sequenced using Illumina MiSeq. Sequences were analyzed using the Quantitative Insights into Microbial Ecology (QIIME version 1.9.1) pipeline. Total bacterial load was evaluated in lower airway samples using digital droplet PCR targeting the 16S rRNA gene. RESULTS:Of the 148 patients included, 114 survived (77%) and 34 (23%) died. Among those with poor clinical outcome, there was a non-statistically significant trend towards higher age and BMI. Patients who died more commonly had chronic kidney disease and prior cerebrovascular accidents, and more often required dialysis. There was no statistically significant difference in the rate of positive bacterial respiratory or blood cultures among those that survived vs. those that died (75 vs. 73% and 43 vs 38%, respectively). Topographical analysis of the 16S RNA microbiome shows compositional differences between the upper and lower airways based on β diversity comparisons. When comparing across clinical outcomes, the α diversity was lower in the dead group but there was no statistically significant difference in overall community composition (β diversity). Taxonomic differential enrichment analysis using DESeq analysis showed that oral commensals were enriched in the group that survived. Patients that died had a higher bacterial load in their lower airways than those who survived. CONCLUSION:Using samples obtained via bronchoscopy we identified lower airway microbiota signatures associated with mortality among critical patients infected with SARS-CoV2. Taxonomic signals identified as associated with poor prognosis did not reveal bacterial taxa commonly classified as respiratory pathogens. This data is not supportive of the hypothesis that secondary untreated bacterial co-infections are responsible for increased mortality in patients with severe SARS-CoV-2.

Design of mobile learning rhythmic gymnastics materials for high school/vocational high school levels as a distance learning media during the covid-19 pandemic

This study used a survey method, collecting data used observation, questionnaires, and interviews. The data analysis technique used in this study is qualitative descriptive statistics. The results of observations of questionnaires and interviews are that;1) There is a need for innovations in designing or developing a media/learning model based on mobile learning that is adapted to the times and technological advances, especially in the subject of rhythmic gymnastics at the high school/vocational high school level so that students can learn independently safely and healthily during the Copid-19 pandemic. 2) Design of mobile learning material for high school/vocational gymnastics is feasible to be used as a media for distance learning during the Covid-19 pandemic, based on the results of expert validation and field trials, namely;1) the results of the validation of the gymnastics material expert explained that the series of rhythmic gymnastics movements were feasible because they could be applied, 2) the results of the validation by the media expert obtained a value of 80% in the very good category, and 3) the results of the validation of the learning experts were 81% in the very good category. While the results of field trials in both small-scale and large-scale trials, the overall results show that the mobile learning design is attractive, easy to use and students can practice the gymnastics movements that have been developed. This shows that the mobile learning design is suitable for use as a distance learning medium in the high school/vocational high school level rhythmic gymnastics material during the Covid-19 pandemic because the media is easy to use and useful in the learning process so that learning objectives can be achieved properly. © 2021 by authors, all rights reserved.