Analytic sensitivity of the Abbott BinaxNOW lateral flow immunochromatographic assay for the SARS-CoV-2 Omicron variant

The emergence of the SARS-CoV-2 Omicron variant has motivated a re-evaluation of the test characteristics for lateral flow immunochromatographic assays (LFIAs), commonly referred to as rapid antigen tests. To address this need, we evaluated the analytic sensitivity of one of the most widely used LFIAs in the US market, the Abbott BinaxNOW COVID-19 Ag At-Home Card using 32 samples of Omicron and 30 samples of the Delta variant. Samples were chosen to intentionally over-represent the range of viral loads where differences are most likely to appear. We found no changes in the analytic sensitivity of the BinaxNOW assay by variant even after controlling for variation in cycle threshold values in the two populations. Similar to prior studies, the sensitivity of the assay is highly dependent on the amount of virus present in the sample. While the analytic sensitivity of the BinaxNOW LFIA remains intact versus the Omicron variant, its clinical sensitivity is influenced by the interaction between viral replication, the dynamics of tissue tropism and the timing of sampling. Further research is necessary to optimally adapt current testing strategies to robustly detect early infection by the Omicron variant to prevent transmission.

Productivity of medium-fiber cotton genotypes selected according to test characteristics in combination with classical breeding methods

The most important factor in the intensification and rise of the production of the cotton industry in Tajikistan is the selection of new varieties characterized by high yield and its quality. The increase in the production of the cotton industry can be achieved not by expansion of acreage, since this possibility is very limited in a mountainous country, but by breeding new varieties of cotton and spreading them into production. The use of photosynthetic test characteristics in breeding contributes to the process of creating new varieties that meet the demand of agricultural production and the textile industry, i.e. varieties with a complex of economically useful features — precocity, high productivity, resistance to diseases and pests, optimal adaptive properties, characterized by high fiber yield and its technological quality. By methods of hybridization and selection by offspring on the basis of photosynthetic test characteristics from domestic and foreign variety samples, 28 introgressive genotypes were created that are characterized by complex of economically useful traits. It was found that out of the 28 genotypes of medium-fiber cotton studied by us, according to the main indicators of productivity — the number of full-fledged boxes per plant, the mass of raw cotton of one box and the yield — 6 genotypes were notable. The number of boxes per plant in the most productive was 12–15 pieces, the mass of raw cotton of one box is up to 6.6 g, and the yield of raw cotton is from 71.5 to 93.0 g/plant, which is significantly higher than in the standard Hisor variety.

Anti-NMDAR Encephalitis in the Netherlands, Focusing on Late-Onset Patients and Antibody Test Accuracy

Background and ObjectivesTo describe the clinical features of anti-NMDAR encephalitis, emphasizing on late-onset patients and antibody test characteristics in serum and CSF.MethodsNationwide observational Dutch cohort study, in patients diagnosed with anti-NMDAR encephalitis between 2007 and 2019.ResultsOne hundred twenty-six patients with anti-NMDAR encephalitis were included with a median age of 24 years (range 1–86 years). The mean annual incidence was 1.00/million (95% CI 0.62–1.59). Patients ≥45 years of age at onset (19%) had fewer seizures (46% vs 71%, p = 0.021), fewer symptoms during disease course (3 vs 6 symptoms, p = 0.020), and more often undetectable serum antibodies compared with younger patients (p = 0.031). In the late-onset group, outcome was worse, and all tumors were carcinomas (both p < 0.0001). CSF was more accurate than serum to detect anti-NMDAR encephalitis (sensitivity 99% vs 68%, p < 0.0001). Using cell-based assay (CBA), CSF provided an unconfirmed positive test result in 11/2,600 patients (0.4%); 6/11 had a neuroinflammatory disease (other than anti-NMDAR encephalitis). Patients with anti-NMDAR encephalitis, who tested positive in CSF only, had lower CSF antibody titers (p = 0.003), but appeared to have an equally severe disease course.DiscussionAnti-NMDAR encephalitis occurs at all ages and is less rare in the elderly patients than initially anticipated. In older patients, the clinical phenotype is less outspoken, has different tumor association, and a less favorable recovery. Detection of antibodies in CSF is the gold standard, and although the CBA has very good validity, it is not perfect. The clinical phenotype should be leading, and confirmation in a research laboratory is recommended, when in doubt.

Graphical analysis to determine the stability and adaptability of yield characteristics of dwarf cashew trees

The cashew culture provides jobs and boosts the economy of the Northeast region and is therefore of great socioeconomic importance. In genetic improvement programs, the existence of an interaction between genotypes and environments has been observed, making studies of adaptability and stability essential for effective selection. Thus, the objective was to study the performance of early dwarf cashew clones using the GGE Biplot in three agricultural years (2016–2018). The experimental design was in randomized blocks with 25 treatments (clones) and three replications. The plot consisted of four plants spaced 8 × 8 m apart. The variables evaluated were nut yield throughout the harvest (PRC), average nut weight (PMC), and percentage of nuts pierced (PCF). The clones most characterized as ideotypes were T25, T14, T7, T8, T2, T10, T15, and T22 for PRC; T12, T1, and T16 for PMC; and T5, T24, T21, and T8 for PCF, with coincidence for T8 in PC and PCF. Clones with values above the general average, with emphasis on stability, were T14 and T2 for PRC; T12, T1, T16, T8, and T22 for PMC; and T5 and T22 for PCF. The years with test characteristics, that is, those with average environmental factors for all years, were 2016 for PRC and 2018 for PCF, with no test year for PMC; the every years were more discriminating to PCF, with the exception of 2016 for PRC.

Improving the Efficiency of the Digits-in-Noise Hearing Screening Test: A Comparison Between Four Different Test Procedures

Purpose: This study compared the test characteristics, test–retest reliability, and test efficiency of three novel digits-in-noise (DIN) test procedures to a conventional antiphasic 23-trial adaptive DIN (D23). Method: One hundred twenty participants with an average age of 42 years ( SD = 19) were included. Participants were tested and retested with four different DIN procedures. Three new DIN procedures were compared to the reference D23 version: (a) a self-selected DIN (DSS) to allow participants to indicate a subjective speech recognition threshold (SRT), (b) a combination of self-selected and adaptive eight-trial DIN (DC8) that utilized a self-selected signal-to-noise ratio (SNR) followed by an eight-trial adaptive DIN procedure, and (c) a fixed SNR DIN (DF) approach using a fixed SNR value for all presentations to produce a pass/fail test result. Results: Test–retest reliability of the D23 procedure was better than that of the DSS and DC8 procedures. SRTs from DSS and DC8 were significantly higher than SRTs from D23. DSS was not accurate to discriminate between normal-hearing and hard of hearing listeners. The DF and DC8 procedures with an adapted cutoff showed good hearing screening test characteristics. All three novel DIN procedure durations were significantly shorter (< 70 s) than that of D23. DF showed a reduction of 46% in the number of presentations compared to D23 (from 23 presentations to an average of 12.5). Conclusions: The DF and DC8 procedures had significantly lower test durations than the reference D23 and show potential to be more time-efficient screening tools to determine normal hearing or potential hearing loss. Further studies are needed to optimize the DC8 procedure. The reference D23 remains the most reliable and accurate DIN hearing screening test, but studies in which the potentially efficient new DIN procedures are compared to pure-tone thresholds are needed to validate these procedures.