National Kriging Exposure Estimation: Liao et al. Respond

Szpiro et al. suggest that our findings Liao et al. (2006) do not adequately support using national-scale, log-normal ordinary kriging to estimate daily mean concentrations of PM10 (particulate matter with aerodynamic diameter ≤ 10 µm) at unmonitored locations in the contiguous United States. They posit that the absence of the cross-validation SE prevents evaluating the validity of kriging estimation, as we implemented in this context, and the comparability of both regionalversus national-scale kriging and manually modified versus semiautomated, defaultcalculated semivariograms

GIS Approaches for the Estimation of Residential-Level Ambient PM Concentrations

Spatial estimations are increasingly used to estimate geocoded ambient particulate matter (PM) concentrations in epidemiologic studies because measures of daily PM concentrations are unavailable in most U.S. locations. This study was conducted to a) assess the feasibility of large-scale kriging estimations of daily residential-level ambient PM concentrations, b) perform and compare cross-validations of different kriging models, c) contrast three popular kriging approaches, and d ) calculate SE of the kriging estimations. We used PM data for PM with aerodynamic diameter ≤10 μm (PM10) and aerodynamic diameter ≤ 2.5 μm (PM2.5) from the U.S. Environmental Protection Agency for the year 2000. Kriging estimations were performed at 94,135 geocoded addresses of Women’s Health Initiative study participants using the ArcView geographic information system. We developed a semiautomated program to enable large-scale daily kriging estimation and assessed validity of semivariogram models using prediction error (PE), standardized prediction error (SPE), root mean square standardized (RMSS), and SE of the estimated PM. National- and regional-scale kriging performed satisfactorily, with the former slightly better. The average PE, SPE, and RMSS of daily PM10 semivariograms using regular ordinary kriging with a spherical model were 0.0629, −0.0011, and 1.255 μg/m3, respectively; the average SE of the estimated residential-level PM10 was 27.36 μg/m3. The values for PM2.5 were 0.049, 0.0085, 1.389, and 4.13 μg/m3, respectively. Lognormal ordinary kriging yielded a smaller average SE and effectively eliminated out-of-range predicted values compared to regular ordinary kriging. Semiautomated daily kriging estimations and semivariogram cross-validations are feasible on a national scale. Lognormal ordinary kriging with a spherical model is valid for estimating daily ambient PM at geocoded residential addresses

Ambient Particulate Air Pollution and Ectopy—The Environmental Epidemiology of Arrhythmogenesis in Women's Health Initiative Study, 1999–2004

The relationships between ambient PM2.5 and PM10 and arrhythmia and the effect modification by cigarette smoking were investigated. Data from EPA air quality monitors and an established national-scale, log-normal kriging method were used to spatially estimate daily mean concentrations of PM at addresses of 57,422 individuals from 59 examination sites in 24 US states in 1999-2004. The acute and subacute exposures were estimated as mean, geocoded address-specific PM concentrations on the day of, 0-2 days before, and averaged over 30 days before the ECG (Lag0; Lag1; Lag2; Lag1-30). At the time of standard 12-lead resting ECG, the mean age (SD) of participants was 67.5 (6.9) years (84% non-Hispanic White; 6% current smoker; 15% with coronary heart disease; 5% with ectopy). After the identification of significant effect modifiers, two-stage random-effects models were used to calculate center-pooled odds ratios and 95% confidence intervals (OR, 95% CI) of arrhythmia per 10 μg/m3 increase in PM concentrations. Among current smokers, Lag0 and Lag1 PM concentrations were significantly associated ventricular ectopy (VE) - the OR (95% CI) for VE among current smokers was 2 (1.32-3.3) and 1.32 (1.07-1.65) at Lag1 PM2.5 and PM10, respectively. The interactions between current smoking and acute exposures (Lag0; Lag1; Lag2) were significant in relationship to VE. Acute exposures were not significantly associated with supraventricular ectopy (SVE), or with VE among non-smokers. Subacute (Lag1-30) exposures were not significantly associated with arrhythmia. Acute PM2.5 and PM10 exposure is directly associated with the odds of VE among smokers, suggesting that they are more vulnerable to the arrhythmogenic effects of PM

Mesoscopic prediction on the effective thermal conductivity of unsaturated clayey soil with double porosity system

International audienceThe effect of water distribution on heat conduction in unsaturated structural clayey soils with double porosity system is investigated in the present study. A dual-porosity model consisting of intra-aggregate and inter-aggregate pores is developed to describe the water distribution within intra-aggregate and inter-aggregate pores. Heat transfer using this model is then numerically simulated to determine the soil effective thermal conductivity. The obtained values are compared with available experimental data. The results show that the model can predict the accurate soil thermal conductivity values at various water contents and densities. On one hand, the model shows a higher soil thermal conductivity when water content and/or dry density are higher. On the other hand, the model shows an effect of water distribution on the soil thermal conductivity; this later is higher when water is preferentially distributed within aggregates than between aggregates. In addition, the model can give a direct visualization of heat transfer mechanisms in unsaturated clayey soils with double porosity system. In fact, heat conduction is dominant in the wet region of the dual-porosity space. This study provides both a useful predictive model of thermal conductivity and a better understanding on the physical mechanism of heat conduction in unsaturated structural clayey soils or other multiphase media with double porosity system

Redefining Disease Severity with Special Area Involvement and Reflecting on Treatment Patterns in a Real-World Psoriasis Population

Abstract Background The International Psoriasis Council (IPC) recommends an approach that considers body surface area (BSA), involvement in special areas, and treatment history for classifying patients as candidates for topical or systemic treatment. This study aimed to quantify the burden of psoriasis by describing BSA distribution, special area involvement, and treatments in a real-world population. Methods This retrospective cohort study included patients with psoriasis from the Optum® deidentified Electronic Health Records database with a BSA value ( 10%) recorded between 1 March 2014 and 1 September 2020. Treatments and special area involvement (face, scalp, palms/soles, nails, genitals) were identified within 90 days of the BSA value and stratified by BSA category. Results Among eligible patients (N = 5120), mean age was 51.4 years and 49.3% were women. The majority of patients (78.9%) were treated with any topical. Proportions of patients with BSA  10% were 23.4%, 41.9%, and 34.6%, respectively; proportions with 0, 1, and 2+ special areas were 21.6%, 31.6%, and 45.7%, respectively; and 44.4%, 45.7%, and 45.9% of patients with BSA  10%, respectively, had 2+ special areas. Conclusion The IPC classification can likely identify many more patients who may benefit from systemic therapy than BSA alone. Graphical Abstrac

CRISPR/Cas13a-Assisted accurate and portable hepatitis D virus RNA detection

ABSTRACTBackground & Aims Hepatitis delta virus (HDV) infection accelerates the progression of chronic hepatitis B virus (HBV) infection, posing a large economic and health burden to patients. At present, there remains a lack of accurate and portable detection methods for HDV RNA. Here, we aim to establish a convenient, rapid, highly sensitive and specific method to detect HDV RNA using CRISPR–Cas13a technology.Methods We established fluorescence (F) and lateral flow strip (L) assays based on CRISPR–Cas13a combined with RT–PCR and RT-RAA for HDV RNA detection, respectively. we conducted a cohort study of 144 patients with HDV-IgG positive to evaluate the CRISPR–Cas13a diagnostic performance for identifying HDV in clinical samples, compared to RT–qPCR and RT-ddPCR.Results For synthetic HDV RNA plasmids, the sensitivity of RT–PCR-CRISPR-based fluorescence assays was 1 copy/μL, higher than that of RT–qPCR (10 copies/μL) and RT-ddPCR (10 copies/μL); for HDV RNA-positive samples, the sensitivity of RT-RAA-CRISPR-based fluorescence and lateral flow strip assays was 10 copies/μL, as low as that of RT–qPCR and RT-ddPCR, and the assay took only approximately 85 min. Additionally, the positivity rates of anti-HDV IgG-positive samples detected by the RT–qPCR, RT-ddPCR, RT–PCR-CRISPR fluorescence and RT-RAA-CRISPR lateral flow strip methods were 66.7% (96/144), 76.4% (110/144), 81.9% (118/144), and 72.2% (104/144), respectively.Conclusions We developed a highly sensitive and specific, as well as a portable and easy CRISPR-based assay for the detection of HDV RNA, which could be a prospective measure for monitoring the development of HDV infection and evaluating the therapeutic effect