Experimental and theoretical investigations of traditional solar still productivity in cold climatic

Solar distillation is an important technology to get potable water from saltwater using clean and free solar energy. In the current study, an experimental and theoretical investigation of a single-slope traditional solar still was carried out, and the freshwater productivity and thermal efficiency were evaluated for four typical days (19/06, 17/07, 22/08, and 15/09) of 2019 by implementing temperature parameters in different points of the solar still, and the weather parameters such as solar radiation, and ambient air temperature. The study showed an acceptable agreement between the experimental and theoretical results with an average of 6.6% measured deviation of the experimental data. It was noticed that the highest values of productivity were recorded on July 17, 2019.

Intra- and inter-observer reproducibility of r-ASRM endometriosis classification system and its components, using edited videotaped laparoscopic procedures

Several classification systems have been proposed for endometriosis but the search for the ideal system is ongoing. While the most commonly used system has historically been r-ASRM, this system is not fit for purpose, particularly for deep endometriosis. In order to explore strategies to devise a new system and learn from problems with the existing ones, this study was designed to assess the reproducibility of each component in r-ASRM and its total score using videotaped laparoscopic procedures. Two surgeons independently scored 64 edited videos of laparoscopic endometriosis procedure, twice. Using the Kappa statistic, the agreement of the scores given was analyzed. r-ASRM showed a moderate inter-observer agreement (ƙ = 0.503) and good intra-observer agreement (ƙ = 0.774 and 0.682 for scorer 1 and 2 respectively) for overall disease staging. The agreement for each component of the system, however, was highly variable. The least agreement was observed for the peritoneum with ƙ = 0.157 and ƙ = 0.362 respectively for inter-observer and intra-observer. The lowest intra-observer agreement was seen for cul-de-sac for scorer 2 (ƙ = 0.382). Whilst the overall rASRM shows acceptable agreement between two scorers, this agreement seems to be the product of inconsistent scoring for each component.

Agreement between heart rate at first ventilatory threshold on treadmill and at 6-min walk test in coronary artery disease patients on β-blockers treatment

The purpose of this study was to verify the accuracy of the agreement between heart rate at the first ventilatory threshold (HRVT1) and heart rate at the end of the 6-min walk test (HR6MWT) in coronary artery disease (CAD) patients on β-blockers treatment. This was a cross-sectional study with stable CAD patients, which performed a cardiopulmonary exercise test (CPET) on a treadmill and a 6-min walk test (6MWT) on nonconsecutive days. The accuracy of agreement between HRVT1 and HR6MWT was evaluated by Bland–Altman analysis and Lin’s concordance correlation coefficient (rc), mean absolute percentage error (MAPE), and standard error of estimate (SEE). Seventeen stable CAD patients on β-blockers treatment (male, 64.7%; age, 61± 10 years) were included in data analysis. The Bland–Altman analysis revealed a negative bias of -0.41 ± 6.4 bpm (95% limits of agreements, -13 to 12.2 bpm) between HRVT1 and HR6MWT. There was acceptable agreement between HRVT1 and HR6MWT (rc = 0.84; 95% confidence interval, 0.63 to 0.93; study power analysis= 0.79). The MAPE of the HR6MWT was 5.1% and SEE was 6.6 bpm. The ratio HRVT1/HRpeak and HR6MWT/HRpeak from CPET were not significantly different (81%± 5% vs. 81%± 6%, P= 0.85); respectively. There was a high correlation between HRVT1 and HR6MWT (r= 0.85, P< 0.0001). Finally, the results of the present study demonstrate that there was an acceptable agreement between HRVT1 and HR6MWT in CAD patients on β-blockers treatment and suggest that HR6MWT may be useful to prescribe and control aerobic exercise intensity in cardiac rehabilitation programs.

Ionospheric Clutter Suppression with an Auxiliary Crossed-Loop Antenna in a High-Frequency Radar for Sea Surface Remote Sensing

Ionospheric clutter is one of the main problems for high-frequency surface wave radars (HFSWRs), as it severely interferes with sea surface state monitoring and target detection. Although a number of methods exist for ionospheric clutter suppression, most are suitable for radars with a large-sized array and are inefficient for small-aperture radars. In this study, we added an auxiliary crossed-loop antenna to the original compact radar antenna, and used an adaptive filter to suppress the ionospheric clutter. The experimental results of the HFSWRs data indicated that the suppression factor of the ionospheric clutter was up to 20 dB. Therefore, the Bragg peaks that were originally submerged by the ionospheric clutters could be recovered, and the gaps in the current maps can, to a large extent, be filled. For an oceanographic radar, the purpose of suppressing ionospheric clutter is to extract an accurate current speed; the radial current fields that were generated by our method showed an acceptable agreement with those generated by GlobCurrent data. This result supports the notion that the ionospheric suppression technique does not compromise the estimation of radial currents. The proposed method is particularly efficient for a compact HFSWRs, and can also be easily used in other types of antennas.

Assessing Heart Rate Using Consumer Technology Association Standards

It is difficult for developers, researchers, and consumers to compare results among emerging wearable technology without using a uniform set of standards. This study evaluated the accuracy of commercially available wearable technology heart rate (HR) monitors using the Consumer Technology Association (CTA) standards. Participants (N = 23) simultaneously wore a Polar chest strap (criterion measure), Jabra Elite earbuds, Scosche Rhythm 24 armband, Apple Watch 4, and Garmin Forerunner 735 XT during sitting, activities of daily living, walking, jogging, running, and cycling, totaling 57 min of monitored activity. The Apple Watch mean bias was within ±1 bpm, and mean absolute percent error (MAPE) was <3% in all six conditions. Garmin underestimated HR in all conditions, except cycling and MAPE was >10% during sedentary, lifestyle, walk-jog, and running. The Jabra mean bias was within ±5 bpm for each condition, and MAPE exceeded 10% for walk-jog. The Scosche mean bias was within ±1 bpm and MAPE was <5% for all conditions. In conclusion, only the Apple Watch Series 4 and the Scosche Rhythm 24 displayed acceptable agreement across all conditions. By employing CTA standards, future developers, researchers, and consumers will be able to make true comparisons of accuracy among wearable devices.

Development and Interrater Reliability of an Observational School Environment Checklist: A Practical, Comprehensive Tool to Assess Healthy Eating and Physical Activity Opportunities in Schools

Introduction Comprehensive, objective assessment of schools’ eating and physical activity environments is critical to developing and evaluating policies and interventions to reduce pediatric obesity inequities; however, few tools exist that describe the entire school comprehensively and are feasible with restricted resources. This study describes development and reliability of the observational school environment checklist (OSEC), a comprehensive observational audit tool. Method We developed the OSEC through iterative adaptations of existing instruments and pilot testing. The tool assesses four focus areas: cafeteria, lobby/hallway, gym, and outdoor areas. For reliability testing, two trained auditors independently completed the OSEC and met to resolve disagreements. For items with poor agreement, a third independent coder coded photographs taken during auditing. Percent agreement and Cohen’s kappa were calculated for all items and across four evidence-based constructs: atmosphere, accessibility, attractiveness, and advertising. Results After iterative development, the 88-item OSEC was tested for reliability in 18 schools. Items with poor (<80%) agreement or redundancy were discarded or reworded ( n = 16 items). All four constructs had acceptable agreement, ranging by focus area: 72.3% (attractiveness), 86.3% to 97.1% (atmosphere), 82.9% to 100% (accessibility), and 92.9% (advertising). Cohen’s kappa ranges were acceptable: 0.66–0.91 (atmosphere), 0.60–1.00 (accessibility), 0.46 (attractiveness), and 0.77 (advertising). After adding similar items across domains ( n = 49) to improve comprehensiveness, the final tool contained 121 binary items. Implications The OSEC reliably and comprehensively captures the school environment. It requires few resources or expertise to administer, has acceptable reliability, and can assess atmosphere, accessibility, attractiveness, and advertising in school areas where students engage in eating and physical activity.

Wrist-Based Photoplethysmography Assessment of Heart Rate and Heart Rate Variability: Validation of WHOOP

Heart rate (HR) and HR variability (HRV) infer readiness to perform exercise in athletic populations. Technological advancements have facilitated HR and HRV quantification via photoplethysmography (PPG). This study evaluated the validity of WHOOP’s PPG-derived HR and HRV against electrocardiogram-derived (ECG) measures. HR and HRV were assessed via WHOOP and ECG over 15 opportunities. WHOOP-derived pulse-to-pulse (PP) intervals were edited with WHOOP’s proprietary filter, in addition to various filter strengths via Kubios HRV software. HR and HRV (Ln RMSSD) were quantified for each filter strength. Agreement was assessed via bias and limits of agreement (LOA), and contextualised using smallest worthwhile change (SWC) and coefficient of variation (CV). Regardless of filter strength, bias (≤0.39 ± 0.38%) and LOA (≤1.56%) in HR were lower than the CV (10–11%) and SWC (5–5.5%) for this parameter. For Ln RMSSD, bias (1.66 ± 1.80%) and LOA (±5.93%) were lowest for a 200 ms filter and WHOOP’s proprietary filter, which approached or exceeded the CV (3–13%) and SWC (1.5–6.5%) for this parameter. Acceptable agreement was found between WHOOP- and ECG-derived HR. Bias and LOA in Ln RMSSD approached or exceeded the SWC/CV for this variable and should be interpreted against its own level of bias precision.

Validation of the European Prospective Investigation into Cancer (EPIC) Food Frequency Questionnaire for use among Adults in Lebanon

Objective: To validate the EPIC food frequency questionnaire (FFQ) in Lebanon. Design: Validation of the EPIC FFQ was done against three 24-hour recalls. Unadjusted and energy adjusted correlations, Bland Altman plots, and weighed kappa statistics were used to assess the agreement between the two methods. Setting: Lebanon. Participants: 119 adults (staff and students) at a Lebanese University. Results: Good unadjusted and energy-adjusted correlation coefficients were found between data from the two methods which ranged from −0.002 (vitamin A) to 0.337 (carbohydrates) and were all statistically significant except for vitamin D, vitamin E, vitamin A, selenium, and niacin. Slight/fair agreement was reported through weighed kappa estimates for unadjusted data ranging from −0.05 (vitamin C) to 0.248 (magnesium) and for energy-adjusted data ranging from −0.034 (vitamin A) to 0.203 (phosphorus). Individuals were categorised into exact and adjacent quartiles with an average of 78% for unadjusted data and 70% for energy-adjusted data, indicating a very good agreement between the EPIC FFQ and the average of the 24-HRs data. The visual inspection of the Bland-Altman plots revealed an over-estimation of energy, carbohydrates, protein, and fat intakes by the FFQ method. Conclusion: Overall, when all tests were taken into consideration, this study demonstrated an acceptable agreement of the EPIC FFQ with the 24-hour dietary recall method and significantly good correlations between dietary intakes. Therefore, the EPIC FFQ can be considered a valid tool for assessing diet in epidemiological studies among Lebanese adults.

Investigation of clinically acceptable agreement between two methods of automatic measurement of limb occlusion pressure: a randomised trial

Background Development of automatic, pneumatic tourniquet technology and use of personalised tourniquet pressures has improved the safety and accuracy of surgical tourniquet systems. Personalisation of tourniquet pressure requires accurate measurement of limb occlusion pressure (LOP), which can be measured automatically through two different methods. The ‘embedded LOP’ method measures LOP using a dual-purpose tourniquet cuff acting as both patient sensor and pneumatic effector. The ‘distal LOP’ method measures LOP using a distal sensor applied to the patient’s finger or toe of the operating limb, using photoplethysmography to detect volumetric changes in peripheral blood circulation. The distal LOP method has been used clinically for many years; the embedded LOP method was developed recently with several advantages over the distal LOP method. While both methods have clinically acceptable accuracy in comparison to LOP measured using the manual Doppler ultrasound method, these two automatic methods have not been directly compared. The purpose of this study is to investigate if the embedded and distal methods of LOP measurement have clinically acceptable agreement. The differences in pairs of LOP measurement in the upper and lower limbs of 81 healthy individuals were compared using modified Bland and Altman analysis. In surgery, it is common for cuff pressure to deviate from the pressure setpoint due to limb manipulation. Surgical tourniquet systems utilise a ± 15 mmHg pressure alarm window, whereby if the cuff pressure deviates from the pressure setpoint by > 15 mmHg, an audiovisual alarm is triggered. Therefore, if the difference (bias) ± SE, 95% CI of the bias and SD of differences ± SE in LOP measurement between the embedded and distal methods were all within ±15 mmHg, this would demonstrate that the two methods have clinically acceptable agreement. Results LOP measurement using the embedded LOP method was − 0.81 ± 0.75 mmHg (bias ± standard error) lower than the distal LOP method. The 95% confidence interval of the bias was − 2.29 to 0.66 mmHg. The standard deviation of the differences ± standard error was 10.35 ± 0.49 mmHg. These results show that the embedded and distal methods of LOP measurement demonstrate clinically acceptable agreement. Conclusions The findings of this study demonstrate clinically acceptable agreement between the embedded and distal methods of LOP measurement. The findings support the use of the embedded LOP method of automatic LOP measurement using dual-purpose tourniquet cuffs to enable accurate, effective and simple prescription of personalised tourniquet cuff pressures in a clinical setting.

Misreporting of Physical Activity and Sedentary Behavior in Parents-to-Be: A Validation Study across Sex

This study validated the International Physical Activity Questionnaire (IPAQ) and the Context-specific Sedentary Behavior Questionnaire (CSBQ) against accelerometry among parents-to-be. Sex-differences in potential misreporting of physical activity (PA) and sedentary behavior (SB) were also investigated. Self-reported total PA (TPA), light-intensity PA (LPA), moderate-intensity PA (MPA), vigorous-intensity PA (VPA), moderate-to-vigorous-intensity PA (MVPA), and SB of 91 parents-to-be (41 men and 50 women) were compared with Actigraph data according to sex. Furthermore, the extent of misreporting was compared between sexes. Strong correlations for TPA and weak-to-moderate correlations for LPA, MPA, VPA, MVPA, and SB were observed. Participants underestimated TPA by 1068 min/week (=17.8 h/week; −50%), LPA by 1593 min/week (=26.6 h/week; −83%), and SB by 428 min/week (=7.1 h/week; −11%) and overestimated MPA by 384 min/week (=6.4 h/week; +176%) and MVPA by 525 min/week (=8.8 h/week; +224%). Males overreported VPA more than females in absolute minutes per week (238 min/week, i.e., 4.0 h/week vs. 62 min/week, i.e., 1.0 h/week), whereas, in relative terms, the opposite (+850% vs. +1033%) was true. The IPAQ and CSBQ can be used with caution to estimate TPA and SB among parents-to-be considering a strong correlation but low agreement for TPA and a weak-to-moderate correlation but acceptable agreement for SB. We disadvise using these self-reports to estimate PA on the distinct intensity levels.