A Protective dsRNA is Crucial for Optimum RNAi Gene Silencing in Chilo partellus

RNAi technology is currently employed as an alternate control measure for agricultural pests. However, the variability of RNAi efficiency in insect pests limits the extensive usage of this technology and demands identifying the best target gene for effective RNAi. Four different bacterially-expressed dsRNA and purified dsRNAs coated on artificial diet were fed to the larvae. The transcripts expression was analyzed at 5 days and 15 days post-exposure to various dsRNAs. In the larvae fed on bacterially-expressed dsRNA, knockdown percentages were 80 and 57% knockdown in Acetylcholinesterase transcript, 40 and 60% gene knockdown in Arginine kinase, 74 and 73% knockdown in Chymotrypsin, and 80 and 20% reduction in V-ATPase transcript expression. Overall, the mRNA knockdown percentages in the targeted genes were more pronounced at 5 days of exposure to bacterially-expressed crude dsRNA than 15 days of exposure. However, most purified dsRNAs rarely induce any significant knockdown except dsARG, which reduced the arginine kinase transcript by 40%. Our findings suggest that for optimum RNAi in C. partellus, the dsRNA must be protected from direct access with nucleases. © 2021 Friends Science Publishers

Risk Identification of Lijiadagou Landslide and Debris Flow Hazards Chain in Yong'an Town, Fengjie County of Chongqing City

Lijiadagou landslide and debris flow hazards chain in Yong’an Town of Fengjie county is one of the representative geohazards. By using satellite remote sensing technology, field investigation and observation, survey and analysis, mechanical analysis and other technical means, this paper makes qualitative or semi quantitative analysis on the hazard environment, instability probability, vulnerability analysis of elements at risk, risk loss, etc. The risk factors of Lijiadagou landslide and debris flow were identified. The conclusion shows that the unique landform and climate of Lijiadagou lay a foundation for the occurrence of multiple debris flows in the history. Under the alternate control of multiple factors such as the nature of the rock and soil mass, the stratum structure that controls the sliding, the complex geomorphic environment, continuous heavy rainfall and the rise and fall of the water level, there are high risks of landslides and debris flows, threatening about 6,000 residents in the middle and front range of Lijiadagou. The risk economic loss of hazards is about 80 million yuan, and will cause serious social impact. It is urgent to strengthen monitoring and early warning, and at the same time take targeted measures against the landslide source area to cut off the hazards chain from the source, so as to achieve a multiplier effect with half the effort.

Re-current Epizootics of Highly Pathogenic Avian Influenza in Nigeria: Status of Vaccination as Alternate control

Epizootic of Highly Pathogenic Avian Influenza subtype H5N1 in Nigeria was successfully contained during the first wave that lasted from 2006 to 2008 without the use of vaccine. Re-current and more severe outbreak was witnessed in 2015 and there are suspicions that some farmers may have resorted to vaccination to prevent infections in their flocks. We investigate evidence of vaccination in farms and the status of vaccination as alternate control for HPAI in Nigeria. The study was carried out in a cross section of 24 commercial poultry farms in four States in South West and North Central Nigeria. Five hundred and one sera collected randomly were screened by agar gel immunodiffusion (AGID) assay for antibody to group specific influenza A nucleoprotein. One hundred and eight sera obtained from five H5N1 infected poultry farms were also concurrently screened. Reactive sera were further analysed by Hemagglutinin Inhibition (HI) test against H5 antigen using 1% suspension of pooled washed chicken red blood cells. Only 8 out of 501 sera (1.6%) had evidence of influenza A antibody. All of the 8 samples were from one farm with 20 samples collected representing 40% seroconversion at farm level. Three out of those sera were positive for H5 at HI titer of 3log2. All other sera including those obtained from HPAI infected farms were negative for influenza antibody. This study confirms limited antibody response to avian influenza subtype H5 most likely due to vaccination in one commercial flock. Vaccination against avian influenza by farmers desperate to protect their investments may lead to unregulated and suboptimal application of vaccines requiring farmers’ and stakeholders’ engagement to forestall negative impact. Keywords: Avian influenza; Control measures; Recurrent outbreaks; Vaccination status.

Illustrating potential effects of alternate control populations on real-world evidence-based statistical analyses

Objective Case–control study designs are commonly used in retrospective analyses of real-world evidence (RWE). Due to the increasingly wide availability of RWE, it can be difficult to determine whether findings are robust or the result of testing multiple hypotheses. Materials and Methods We investigate the potential effects of modifying cohort definitions in a case–control association study between depression and type 2 diabetes mellitus. We used a large (>75 million individuals) de-identified administrative claims database to observe the effects of minor changes to the requirements of glucose and hemoglobin A1c tests in the control group. Results We found that small permutations to the criteria used to define the control population result in significant shifts in both the demographic structure of the identified cohort as well as the odds ratio of association. These differences remain present when testing against age- and sex-matched controls. Discussion Analyses of RWE need to be carefully designed to avoid issues of multiple testing. Minor changes to control cohorts can lead to significantly different results and have the potential to alter even prospective studies through selection bias. Conclusion We believe this work offers strong support for the need for robust guidelines, best practices, and regulations around the use of observational RWE for clinical or regulatory decision-making.

Illustrating Potential Effects of Alternate Control Populations on Real-World Evidence-based Statistical Analyses

Case-control study designs are commonly used in retrospective analyses of Real-World Evidence (RWE). Due to the increasingly wide availability of RWE, it can be difficult to determine whether findings are robust or the result of testing multiple hypotheses. We investigate the potential effects of modifying cohort definitions in a case-control association study between depression and Type 2 Diabetes Mellitus (T2D). We found that small permutations to the criteria used to define the control population result in significant shifts in both the demographic structure of the identified cohort as well as the odds ratio of association. These differences remain present when testing against age and sex-matched controls. We believe this offers strong support for the need for robust guidelines, best practices and regulations around the use of observational RWE for clinical or regulatory decision making.

Influenza Vaccine Effectiveness in the Inpatient Setting: Evaluation of Potential Bias in the Test-Negative Design by Use of Alternate Control Groups

The test-negative design is validated in outpatient, but not inpatient, studies of influenza vaccine effectiveness. The prevalence of chronic pulmonary disease among inpatients can lead to nonrepresentative controls. Test-negative design estimates are biased if vaccine administration is associated with incidence of noninfluenza viruses. We evaluated whether control group selection and effects of vaccination on noninfluenza viruses biased vaccine effectiveness in our study. Subjects were enrolled at the University of Michigan and Henry Ford hospitals during the 2014–2015 and 2015–2016 influenza seasons. Patients presenting with acute respiratory infection were enrolled and tested for respiratory viruses. Vaccine effectiveness was estimated using 3 control groups: negative for influenza, positive for other respiratory virus, and pan-negative individuals; it was also estimated for other common respiratory viruses. In 2014–2015, vaccine effectiveness was 41.1% (95% CI: 1.7, 64.7) using influenza-negative controls, 24.5% (95% CI: −42.6, 60.1) using controls positive for other virus, and 45.8% (95% CI: 5.7, 68.9) using pan-negative controls. In 2015–2016, vaccine effectiveness was 68.7% (95% CI: 44.6, 82.5) using influenza-negative controls, 63.1% (95% CI: 25.0, 82.2) using controls positive for other virus, and 71.1% (95% CI: 46.2, 84.8) using pan-negative controls. Vaccination did not alter odds of other respiratory viruses. Results support use of the test-negative design among inpatients.