392 research outputs found
Real-Time Feedback of Air Quality in Childrenâs Bedrooms Reduces Exposure to Secondhand Smoke
Introduction:Secondhand smoke (SHS) exposure creates health risks for nonsmokers and is especially detrimental to children. This study evaluated whether immediate feedback in response to poor indoor air quality in childrenâs bedrooms can reduce the potential for SHS exposure, as measured by adherence to a World Health Organization (WHO) indoor air standard.Methods:Homes that contained children and an adult who regularly smoked inside (n=298) had an air particle monitor installed in the childâs bedroom. These devices measured the concentration of particulate matter (PM2.5) for approximately three months and, for half of the participants, immediately provided aversive feedback in response to elevated PM2.5. Hierarchical linear models were fit to the data to assess whether the intervention increased the probability that: 1) a given day was below the WHO guideline for daily exposure, and 2) a household established and maintained a smoke-free home (SFH), operationalized as achieving 30 consecutive days below the WHO guideline. The interventionâs impact was calculated as groupby- time effects.Results:The likelihood that a childâs bedroom met the WHO indoor air quality standard on a given day increased such that the baseline versus post-baseline odds ratio (OR) of maintaining indoor PM2.5 levels below the WHO guideline was 2.38 times larger for participants who received the intervention. Similarly, the baseline versus post-baseline OR associated with achieving an SFH was 3.49 times larger for participants in the intervention group.Conclusions:The real-time intervention successfully drove clinically meaningful changes in smoking behavior that mitigated indoor PM2.5 levels in childrenâs bedrooms and thereby reduced SHS exposure. These results demonstrate the effectiveness of targeting sensitive microenvironments by giving caregivers actionable information about childrenâs SHS risks. Future extensions should examine additional microenvironments and focus on identifying the potential for SHS exposure before it occurs
Proper Orthogonal Decomposition Methods for the Analysis of Real-Time Data: Exploring Peak Clustering in a Secondhand Smoke Exposure Intervention
This work explores a method for classifying peaks appearing within a data-intensive time-series. We summarize a case study from a clinical trial aimed at reducing secondhand smoke exposure via the installation of air particle monitors in households. Proper orthogonal decomposition (POD) in conjunction with a k-means clustering algorithm assigns each data peak to one of two clusters. Aversive feedback from the monitors increased the proportion of short-duration, attenuated peaks from 38.8% to 96.6%. For each cluster, a distribution of parameters from a physics-based model of airborne particles is estimated. Peaks generated from these distributions are correctly identified by POD/clustering with \u3e60% accuracy
Comparison between GC-MS-SIM and GC-ECD for the determination of residues of organochlorine and organophosphorus pesticides in Brazilian citrus essential oils.
Ăleos essenciais cĂtricos brasileiros (mandarina, laranja, limĂŁo, bergamota e tangerina) foram analisados a fim de determinar resĂduos de pesticidas organoclorados (aldrin, clordano, dieldrin e dicofol) e organofosforados (clorpirifĂłs metĂlico, dimetoato, metidationa e paration metĂlico). Um estudo comparativo entre cromatografia gasosa acoplada a espectrometria de massas em modo de monitoramento seletivo de Ăons (CG-EM-MSI) e cromatografia gasosa com detector por captura de elĂ©trons (CG-DCE) foi realizado usando extração em fase sĂłlida (EFS) com fase FlorisilÂź para prĂ©-concentração dos pesticidas. A recuperação mĂ©dia dos pesticidas foi de 71 a 83% por CG-EM-MSI e de 99 a 104% por CG-DCE. O limite de quantificação foi de 0,93 a 3,93 mg L-1 por CG-EM-MSI e de 0,09 a 0,12 mg L-1 por CG-DCE. Quinze amostras comerciais de Ăłleos essenciais cĂtricos brasileiros foram analisadas e seis amostras apresentaram contaminação com valores acima do limite mĂĄximo de resĂduos (LMR) permitido pelo Codex Alimentarius
Dissolution of Cadmium Sulphide at pH = 2 in Aqueous Solutions of Sulphuric Acid and Sulphuric Acid Containing Cadmium Sulphate
Dissolution of particulate CdS suspended in aqueous solution of H2SO4 (pH = 2) containing 0.00, 0.05 and 0.10 mol m*3 CdSC>4 respectively was followed by measuring cadmium concentration in suspension filtrates. It takes about 150 days for cadmium concentration in solution to become constant. An exponential type relation correlating cadmium concentration with system parameters (initial cadmium concentration in solution, mass transfer coefficient, weight and specific surface area of CdS, solution volume) and the time. All systems aligned with a single, experimentally determined (mean) mass transfer coefficient value of (8.0 ±
± 1.4) X 10â11 ms-1. Dissolution of CdS was not solute diffusion but probably a surface chemical reaction controlled process
Parameterizing and Validating Existing Algorithms for Identifying Out-of-Bed Time Using Hip-Worn Accelerometer Data from Older Women
Objective: To parameterize and validate two existing algorithms for identifying out-of-bed time using 24-hour hip-worn accelerometer data from older women. Approach: Overall, 628 women (80±6 years old) wore ActiGraph GT3X+ accelerometers 24 hours/day for up to 7 days and concurrently completed sleep-logs. Trained staff used a validated visual analysis protocol to measure in-bed periods on accelerometer tracings (criterion). The Tracy and McVeigh algorithms were adapted for optimal use in older adults. A training set of 314 women was used to choose two key thresholds by maximizing the sum of sensitivity and specificity for each algorithm and data (vertical axis, VA, and vector magnitude, VM) combination. Data from the remaining 314 women were then used to test agreement in waking wear time (i.e., out-of-bed time while wearing the accelerometer) by computing sensitivity, specificity, and kappa comparing the algorithm output with the criterion. Waking wear time-adjusted means of sedentary time, light-intensity physical activity (light PA) and moderate-to-vigorous-intensity physical activity (MVPA) were then estimated and compared. Main results: Waking wear time agreement with the criterion was high for Tracy_VA, Tracy_VM, McVeigh_VA, and highest for McVeigh_VM. Compared to the criterion, McVeigh_VM had mean sensitivity=0.92, specificity=0.87, kappa=0.80, and overall mean difference (±SD) of -0.04±2.5 hours/day. Minutes of sedentary time, light PA, and MVPA adjusted for waking wear time using the criterion measure and McVeigh_VM were not statistically different (p \u3e0.43 | all). Significance: The McVeigh algorithm with optimal parameters using VM performed best compared to criterion sleep-log assisted visual analysis and is suitable for automated identification of waking wear time in older women when visual analysis is not feasible
A Radiotracer Study of CadmiumTransport Across the CdS/ Aqueous Solution Interface
Information on interfacial mass transport of cadmium in cadmium
sulfide suspensions and er equilibrium conditions has been obtained by probing with a radiotracer for cadmium. The transport of Cd2+ ions from the cadmium sulfide solid particles to the saturated solution and visa versa is followed by adding radioactive 109Cd2+ to the solution and measuring the amount of radioactivity present in the solution as a function of time. The amount of exchangeable cadmium in or at the solid/liquid interface, which is deduced from the final value of radioactivity in the solution appeared to be 1.8 to 2.3 times the amount of cadmium in one lattice layer. Compartmental analysis of the experimental data revealed that 4 different cadmium species are involved in the exchange processes, one of which being the cadmium in the bulk of the solution, and another one, representing 40% to 50 of one lattice layer, which exchanges rapidly with the solution in comparison with the other two species left
- âŠ