An AdaBoost Method with K′K-Means Bayes Classifier for Imbalanced Data

This article proposes a new AdaBoost method with k′k-means Bayes classifier for imbalanced data. It reduces the imbalance degree of training data through the k′k-means Bayes method and then deals with the imbalanced classification problem using multiple iterations with weight control, achieving a good effect without losing any raw data information or needing to generate more relevant data manually. The effectiveness of the proposed method is verified by comparing it with other traditional methods based on numerical experiments. In the NSL-KDD data experiment, the F-score values of each minority class are also greater than the other methods.

Research priorities to reduce the impact of COVID-19 in low- and middle-income countries

Background The COVID-19 pandemic has caused disruptions to the functioning of societies and their health systems. Prior to the pandemic, health systems in low- and middle-income countries (LMIC) were particularly stretched and vulnerable. The International Society of Global Health (ISoGH) sought to systematically identify priorities for health research that would have the potential to reduce the impact of the COVID-19 pandemic in LMICs. Methods The Child Health and Nutrition Research Initiative (CHNRI) method was used to identify COVID-19-related research priorities. All ISoGH members were invited to participate. Seventy-nine experts in clinical, translational, and population research contributed 192 research questions for consideration. Fifty-two experts then scored those questions based on five pre-defined criteria that were selected for this exercise: 1) feasibility and answerability;2) potential for burden reduction;3) potential for a paradigm shift;4) potential for translation and implementation;and 5) impact on equity. Results Among the top 10 research priorities, research questions related to vaccination were prominent: health care system access barriers to equitable uptake of COVID-19 vaccination (ranked 1st), determinants of vaccine hesitancy (4th), development and evaluation of effective interventions to decrease vaccine hesitancy (5th), and vaccination impacts on vulnerable population/s (6th). Health care delivery questions also ranked highly, including: effective strategies to manage COVID-19 globally and in LMICs (2nd) and integrating health care for COVID-19 with other essential health services in LMICs (3rd). Additionally, the assessment of COVID-19 patients’ needs in rural areas of LMICs was ranked 7th, and studying the leading socioeconomic determinants and consequences of the COVID-19 pandemic in LMICs using multi-faceted approaches was ranked 8th. The remaining questions in the top 10 were: clarifying paediatric case-fatality rates (CFR) in LMICs and identifying effective strategies for community engagement against COVID-19 in different LMIC contexts. Interpretation Health policy and systems research to inform COVID-19 vaccine uptake and equitable access to care are urgently needed, especially for rural, vulnerable, and/or marginalised populations. This research should occur in parallel with studies that will identify approaches to minimise vaccine hesitancy and effectively integrate care for COVID-19 with other essential health services in LMICs. ISoGH calls on the funders of health research in LMICs to consider the urgency and priority of this research during the COVID-19 pandemic and support studies that could make a positive difference for the populations of LMICs.

Allelic imbalance of HLA-B expression in human lung cells infected with coronavirus and other respiratory viruses.

The human leucocyte antigen (HLA) loci have been widely characterized to be associated with viral infectious diseases using either HLA allele frequency-based association or in silico predicted studies. However, there is less experimental evidence to link the HLA alleles with COVID-19 and other respiratory infectious diseases, particularly in the lung cells. To examine the role of HLA alleles in response to coronavirus and other respiratory viral infections in disease-relevant cells, we designed a two-stage study by integrating publicly accessible RNA-seq data sets, and performed allelic expression (AE) analysis on heterozygous HLA genotypes. We discovered an increased AE pattern accompanied with overexpression of HLA-B gene in SARS-CoV-2-infected human lung epithelial cells. Analysis of independent data sets verified the respiratory virus-induced AE of HLA-B gene in lung cells and tissues. The results were further experimentally validated in cultured lung cells infected with SARS-CoV-2. We further uncovered that the antiviral cytokine IFNß contribute to AE of the HLA-B gene in lung cells. Our analyses provide a new insight into allelic influence on the HLA expression in association with SARS-CoV-2 and other common viral infectious diseases.

Structural insights revealed by crystal structure of B38-CAP, an isoenzyme of carboxypeptidase ACE2, the receptor of SARS-CoV-2.

The worldwide pandemic of Coronavirus disease 2019 (COVID-19) is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and further worsened by the emergence of a variety of SARS-CoV-2 variants. Angiotensin-converting enzyme 2 (ACE2), a carboxypeptidase of M32 family, serves as the receptor of SARS-CoV-2 and key regulator of host renin-angiotensin system (RAS), both of which are mainly mediated via the carboxypeptidase domain of ACE2 (sACE2) or its activity. sACE2 is thus promising in the treatment of COVID-19 but unfortunately weakened by its unstrigent substrate preference and complex interplay with host RAS. B38-CAP, an isoenzyme of ACE2, partically compensates these defects but still encounters the problem related to carboxypeptidase activity and specificity. In this study, we firstly determined the crystal structure of B38-CAP at a resolution of 2.44 Å which exists in dimeric form with the non-crystallographic two-fold axis being in coincidence with the crystallographic two-fold axis. Further structural analysis revealed the structural conservatism feature among M32 family, particularly the catalytic core and moreover lead us to hypothesize that conformational flexibility might play an pivotal role in the catalysis of B38-CAP and ACE2. The work provided here presents key features of the M32 family carboxypeptidase and provides structural basis for further development of B38-CAP-based anti-SARS-CoV-2 drugs.

Compliance with Health-Related Behaviors Guidelines and Its Relationship with Multiple Factors in Preschool Children Aged 3-6 Years: A National Cross-Sectional Survey in China.

PURPOSE: To investigate the compliance rates of health-related behaviors among Chinese preschool children, and to explore how supportive family environment, parental behavior, sociodemographic and community factors affect children's health-related behavior comprehensively. METHOD: Preschool children aged 3 to 6 years were chosen from 5760 villages (residential) committees from 471 counties (districts) of 31 provinces by use of a stratified random sampling procedure, with 10,967 preschool children aged 3-6 years old included. The survey was conducted from September 2020 to November 2020. RESULTS: The proportion of Chinese preschool children who met the moderate to vigorous physical activity (MVPA), screen time behavior (ST), and sleep behavior (SLP) guidelines were 62.3%, 52.8%, and 53.8%. Among the supportive family environment factors, parents' time with their children on weekends had the most significant impact on children's MVPA, ST, and SLP, with the odds ratio (OR) values of 2.18 (95%CI:1.97, 2.40), 0.69 (0.63, 0.76), and 1.62 (1.48, 1.79), respectively. Among the parental behavior factors, the mother's exercise frequency had a strong association with the children's MVPA and SLP, with OR values of 1.65 (1.50, 1.83) and 1.24 (1.13, 1.37), respectively; the mother's screen time was inversely associated with the children's ST with an OR value of 0.47 (0.44, 0.51). CONCLUSIONS: Different types of family environments were associated with the different levels of MVPA, ST and SLP among Chinese preschool children. In addition to the influence of parents' education and family income, parents could also improve their children's behaviors by providing a supportive family environment. The more of these factors presented in a family, the more likely it was for children to meet the guidelines. Therefore, for those families whose children's health-related behaviors needed to be improved, the parents should create supportive family environments, such as by playing less on mobile phone and spending more time with children.

Changes in Chinese Adults' Physical Activity Behavior and Determinants before and during the COVID-19 Pandemic.

PURPOSE: To investigate the changes in Chinese adults' physical activity (PA) behavior and determinants before and during the COVID-19 pandemic. METHOD: A total of 1028 adults (aged 19-59 years) were recruited from 127 urban and rural neighborhoods in China using stratified three-stage probability sampling. Data collection was conducted in December 2019 and July 2020. RESULTS: Compared with the data before the pandemic, individuals' weekly moderate-to-vigorous-intensity PA (MVPA) decreased significantly from 139 min to 120 min, seven months after the outbreak (p = 0.01), with female and rural populations displaying a more significant decrease (p = 0.02). Overall, 13.7% of participants met the PA guidelines (World Health Organization) both before and during the pandemic, while 21.8% met the guidelines only before the pandemic and 18.1% increased their PA and met the PA guidelines during the pandemic. A total of 46.4% did not meet the PA guidelines before or during the pandemic. Determinants of PA behavior change before and during the pandemic included sports skills, self-determined motivation and support from sports organizations. CONCLUSIONS: The Chinese adults' PA levels decreased significantly from before to during the COVID-19 pandemic, particularly among the female population. It is suggested that the enhancement of self-determined motivation, improvement of sport skills, and support from sports organizations might be effective in facilitating individuals' engagement in PA during the pandemic.

Effectiveness of WeChat for Improving Exclusive Breastfeeding in Huzhu County China: Randomized Controlled Trial.

BACKGROUND: The benefits of breastfeeding for both infants and mothers have been well recognized. However, the exclusive breastfeeding rate in China is low and decreasing. Mobile technologies have rapidly developed; communication apps such as WeChat (one of the largest social networking platforms in China) are widely used and have the potential to conveniently improve health behaviors. OBJECTIVE: This study aimed to assess the effectiveness of using WeChat to improve breastfeeding practices. METHODS: This 2-arm randomized controlled trial was conducted among pregnant women from May 2019 to April 2020 in Huzhu County, Qinghai Province, China. Pregnant women were eligible to participate if they were aged 18 years or older, were 11 to 37 weeks pregnant with a singleton fetus, had no known illness that could limit breastfeeding after childbirth, used WeChat through their smartphone, and had access to the internet. A total of 344 pregnant women were recruited at baseline, with 170 in the intervention group and 174 in the control group. Women in the intervention group received breastfeeding knowledge and promotion information weekly through a WeChat official account from their third month of pregnancy to 6 months postpartum. The primary outcome of exclusive and predominant breastfeeding rate was measured 0-1 month, 2-3 months, and 4-5 months postpartum. RESULTS: At 0-1 month postpartum, the exclusive breastfeeding rate was significantly higher in the intervention group than that in the control group (81.1% vs 63.3%; odds ratio [OR] 2.75, 95% CI 1.58-4.78; P<.001). Similarly, mothers in the intervention group were more likely to provide predominantly breast milk (OR 2.77, 95% CI 1.55-4.96; P<.001) and less likely to give dairy products to their children (OR 0.40, 95% CI 0.21-0.75; P=.005). There was no statistically significant difference for exclusive breastfeeding rate 2-3 months (P=.09) and 4-5 months postpartum (P=.27), though more children in the intervention group were exclusively breastfed than those in the control group 2-3 months postpartum (intervention: 111/152, 73.0%; control: 96/152, 63.2%) and 4-5 months postpartum(intervention: 50/108, 46.3%; control: 46/109, 42.2%). CONCLUSIONS: This study is the first effort to promote exclusive breastfeeding through WeChat in China, which proved to be an effective method of promoting exclusive breastfeeding in early life. WeChat health education can be used in addition to local breastfeeding promotion programs. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800017364; http://www.chictr.org.cn/showproj.aspx?proj=29325. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1186/s12889-019-7676-2.