Acceptable Level Of Agreement Research Articles

Monitoring Bar Velocity to Quantify Fatigue in Resistance Training.

We analyzed the effects of load magnitude and bar velocity variables on sensitivity to fatigue. Seventeen resistance-trained men (age=25.7±4.9 years; height=177.0±7.2 cm; body mass=77.7±12.3 kg; back-squat 1RM=145.0±33.9 kg; 1RM/body mass=1.86) participated in the study. Pre- and post-exercise changes in the mean propulsive velocity (MPV) and peak velocity (PV) in the back-squat at different intensities were compared with variations in the countermovement jump (CMJ). CMJ height decreased significantly from pre- to post-exercise (∆%=-7.5 to -10.4; p<0.01; ES=0.37 to 0.60). Bar velocity (MPV and PV) decreased across all loads (∆%=-4.0 to -12.5; p<0.01; ES=0.32 to 0.66). The decrease in performance was similar between the CMJ, MPV (40% and 80% 1RM; p=1.00), and PV (80% 1RM; p=1.00). The magnitude of reduction in CMJ performance was greater than MPV (60% 1RM; p=0.05) and PV (40% and 60% 1RM; p<0.01) at the post-exercise moment. Low systematic bias and acceptable levels of agreement were only found between CMJ and MPV at 40% and 80% 1RM (bias=0.35 to 1.59; ICC=0.51 to 0.71; CV=5.1% to 8.5%). These findings suggest that the back-squat at 40% or 80% 1RM using MPV provides optimal sensitivity to monitor fatigue through changes in bar velocity.

Reliability of the Maximal Lactate Accumulation Rate in Rowers.

The maximal lactate accumulation rate (VLamax) has been linked to lactic anaerobic performance. Hence, accurate and reliable assessment is crucial in sport-specific performance testing. Thus, between-day reliability data of rowing-specific VLamax assessment was examined. Seventeen trained rowers (eight females and nine males; 19.5±5.2 yrs; 1.76±0.08 m; 70.2±8.9 kg; V̇O2max: 54±13 ml/min/kg) performed 20-s sprint tests on two separate days (one week apart) on a rowing ergometer. VLamax, peak lactate concentration, time to peak lactate, and mean rowing power were measured. Good to excellent intraclass correlation coefficients (ICCs), low standard error of measurement (SEM), and acceptable levels of agreement (LoAs; 90% confidence interval) for VLamax (ICC=0.85; SEM=0.02 mmol/L/s; LoA±0.09 mmol/L/s), peak lactate (ICC=0.88; SEM=0.3 mmol/L; LoA±1.4 mmol/l), time to peak lactate (ICC=0.92; SEM=0.1 min; LoA±0.5 min), and mean rowing power (ICC=0.98; SEM=3 W; LoA±39 W) were observed. In addition, VLamax was highly correlated (r=0.96; p≤0.001) to rowing power. Thus, VLamax and sprint performance parameters can be measured highly reliably using this sport-specific sprint test in rowing.

Angiography-based coronary microvascular assessment with and without intracoronary pressure measurements: a systematic review.

In recent years, several indices have been proposed for quantifying coronary microvascular resistance. We intended to conduct a comprehensive review that systematically evaluates indices of microvascular resistance derived from angiography. The objective of this study was to identify and analyze angiography-derived indices of microvascular resistance that have been validated against an invasive reference method. We aimed to compare their limits of agreement with their reference methods and explore their advantages and inherent limitations. We searched PubMed from inception until 2022 for studies on different techniques for quantifying microvascular resistance. Seven studies met the inclusion criteria. Five studies included techniques that applied calculations based solely on invasive angiography, and were validated against invasively measured thermodilution-derived index of microvascular resistance. The remaining two studies combined angiography with invasively measured intracoronary pressure data, and were validated against invasive Doppler measurements. We converted the ± 1.96 standard deviation limits of agreement with the reference method from the seven studies into percentages relative to the cut-off value of the reference method. The lower limits of agreement for angiography-based methods ranged from - 122 to - 60%, while the upper limits ranged from 74 to 135%. The range of the limits of agreement was considerably lower for the two combined angiography- and pressure-based methods, standing at - 52 to 60% and - 25 to 27%. Our findings suggest that combined angiography- and pressure-based methods provide a more reliable assessment of microvascular resistance compared to methods relying solely on angiography. Central illustration. Comparative assessment of image-based methods quantifying microvascular resistance with and without intracoronary pressure measurements. Angiography-based methods rely on angiography alone to calculate the microvascular resistance by utilizing angiographic frame counting to extrapolate coronary flow (Q) and subsequently deriving distal coronary pressure using fluid dynamic equations. Combined angiography- and pressure-based methods utilize invasive intracoronary pressure gradients measured during rest and maximal vasodilation to determine coronary flow in their calculation of microvascular resistance. The combined methods showed more acceptable levels of agreement with their reference methods compared to angiography-based methods alone.

Determining critical power and W′ in running: Accuracy of different two-point models using the power metric

This study aims to determine the validity of the critical power (CP) and the work capacity over CP (W′) obtained from different two-time trial combinations with respect a five-point model. In a 3-week training period, 15 athletes (age: 23 ± 5 years; height: 166 ± 6 cm; body mass: 58 ± 8 kg; 5 km season-best: 15:29 ± 00:53 mm:ss) performed five time-trials (i.e. 3, 4, 5, 10, 20 min) on a 400 m track, from which the mean power outputs were obtained through the Stryd Power Meter. An acceptable level of agreement was considered if the following criteria were met: low bias and standard error of the estimate (SEE) (&lt;14 W [values corresponding to the ±5% of the mean CP]; W′: &lt;2.0 kJ [values corresponding to the ±10% of the mean W′]), R2 &gt; 0.90, and ICC &gt; 0.81. The CP presented an acceptable SEE for CPwork (1.3 ± 0.5%) and CP1/time (2.7 ± 1.1%) when using the five time-trials. For both CP models, the 3–10 min was the shortest valid combination, whereas the 3–20, 4–20, and 5–20 min showed the greatest level of agreement. The W′ presented a high SEE for CPwork (14.1 ± 5.2%) and CP1/time (13.8 ± 6.2%) when using the five time-trials, therefore, none of the two time-trials combinations were considered. The CP parameter can be accurately estimated from different two time-trial combinations, whereas none reached an acceptable level of accuracy for the determination of W′.

RunScribe Sacral Gait Lab™ Validation for Measuring Pelvic Kinematics during Human Locomotion at Different Speeds.

Optoelectronic motion capture systems are considered the gold standard for measuring walking and running kinematics parameters. However, these systems prerequisites are not feasible for practitioners as they entail a laboratory environment and time to process and calculate the data. Therefore, this study aims to evaluate the validity of the three-sensor RunScribe Sacral Gait Lab™ inertial measurement unit (IMU) in measuring pelvic kinematics in terms of vertical oscillation, tilt, obliquity, rotational range of motion, and the maximum angular rates during walking and running on a treadmill. Pelvic kinematic parameters were measured simultaneously using an eight-camera motion analysis system (Qualisys Medical AB, GÖTEBORG, Sweden) and the three-sensor RunScribe Sacral Gait Lab™ (Scribe Lab. Inc. San Francisco, CA, USA) in a sample of 16 healthy young adults. An acceptable level of agreement was considered if the following criteria were met: low bias and SEE (<0.2 times the between-subject differences SD), almost perfect (r > 0.90), and good reliability (ICC > 0.81). The results obtained reveal that the three-sensor RunScribe Sacral Gait Lab™ IMU did not reach the validity criteria established for any of the variables and velocities tested. The results obtained therefore show significant differences between the systems for the pelvic kinematic parameters measured during both walking and running.

Transient Numerical Simulation of a Large-Sized Cement-Mill Fan for Performance Prediction

In many engineering applications, particle-laden flows are a necessary part of the conveying process, but in other situations, they could have unintended consequences that must be avoided. As a part of the exhausting process, the induced cement-mill fan (FN-280) installed in a cement plant operates under critical conditions with the presence of high content of cement particles. Over time the dragged solid particles erode the rotating and stationary parts of the fan causing their damage. If one decides on a numerical approach to predict regions most prone to erosion and track the solid particle's trajectory within the fan domain by assuming a one-way coupling regime between the continuous and discrete solid phases, a deep insight into the flows physics within the centrifugal fan is required. With this aim, a three-dimensional numerical approach for the hole unsteady flow in a large-sized industrial centrifugal fan has been carried out in this paper. A fully resolved sliding mesh approach was employed to take into account the unsteady interaction between the impeller and the discharge volute. Based on the characteristic performance curves, the numerical results of the unsteady simulation at four operating conditions are validated with the experimental data. The comparisons reveal that the results of the unsteady simulation are in an acceptable level of agreement with the experiment, demonstrating the validity of the modelling approach adopted in this study.

Role of various scattering mechanisms on the resistivity of Pr-doped high-Tc cuprate superconductor YBa2Cu3O7–δ

In this paper, we theoretically studied the electrical resistivity of the heavily Pr-doped YBa2Cu3O7−δ single crystal high-Tc superconductor cuprate. The proposed formulation expands the concept of relaxation times from frequency (energy) line widths for multiple scattering processes by leveraging electron quantum dynamics with the aid of the double-time electron Green function. A thorough analysis was carried out to investigate the effect of dopant-atom scattering as well as magnon scattering on the temperature and reduced frequency dependences of electrical resistivity in the temperature range of 20–300 K. An acceptable level of agreement between theory and experiment has been achieved.

Construction of a Nomogram Model to Identify Atherosclerotic Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus.

Approximately 50.0% of patients with type 2 diabetes mellitus (T2DM) experience macrovascular diseases, and nearly 80.0% of them succumb to macrovascular complications. Atherosclerotic cardiovascular disease (ASCVD) ranks among the most prevalent macrovascular complications in T2DM. In this study, we aim to develop a nomogram model for the early detection of ASCVD in T2DM patients, enabling us to provide valuable recommendations for the clinical prevention and management of macrovascular complications in this patient population. This retrospective analysis encompassed 2620 T2DM patients admitted between June 2015 and June 2021. The cohort comprised 1270 T2DM patients with coexisting ASCVD (referred to as the "ASCVD group") and 1350 individuals who did not experience ASCVD (the "non-ASCVD group"). We conducted a comparative assessment of their baseline characteristics and clinical data. A nomogram model for the identification of ASCVD in T2DM patients was constructed utilizing Logistic regression analysis and the R package. The model's performance was evaluated through receiver operating characteristic (ROC) curve analysis and calibration curves. We developed a nomogram model for the identification of ASCVD in T2DM patients, incorporating ten variables: sex, age, hypertension, smoking history, low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio, alanine transaminase (ALT), adenosine deaminase (ADA), postprandial 2-hour C-peptide, monocyte count (MONO), and eosinophil count (EOS). ROC curves demonstrated that the area under the curve (AUC) of the nomogram model for identifying ASCVD in T2DM patients was 0.673 for the training dataset (with a cut-off value of 0.473, specificity of 0.629, and sensitivity of 0.637) and 0.655 for the validation dataset (with a cut-off value of 0.460, specificity of 0.605, and sensitivity of 0.675). The calibration curve indicated a substantial agreement between the predicted and observed cases of ASCVD in the training dataset and an acceptable level of agreement in the validation dataset. The nomogram model effectively identifies ASCVD in T2DM patients, which can be instrumental in pinpointing the high-risk population for ASCVD among T2DM patients and facilitating timely clinical management.

Simpler Is Better—Calibration of Pipe Roughness in Water Distribution Systems

Hydraulic models of water distribution systems (WDSs) need to be calibrated, so they can be used to help to make informed decisions. Usually, hydraulic model calibration follows an iterative process of comparing the simulation results from the model with field observations and making adjustments to model parameters to make sure an acceptable level of agreement between predicted and measured values (e.g., water pressure) has been achieved. However, the manual process can be time-consuming, and the termination criterion relies on the modeler’s judgment. Therefore, various optimization-based calibration methods have been developed. In this study, three different optimization methods, i.e., Sequential Least Squares Programming (SLSQP), a Genetic Algorithm (GA) and Differential Evolution (DE), are compared for calibrating the pipe roughness of WDS models. Their performance is investigated over four different decision variable set formulations with different levels of discretization of the search space. Results obtained from a real-world case study demonstrate that compared to traditional engineering practice, optimization is effective for hydraulic model calibration. However, a finer search space discretization does not necessarily guarantee better results; and when multiple methods lead to similar performance, a simpler method is better. This study provides guidance on method and formulation selection for calibrating WDS models.

Intrarater and interrater agreement of a 6-item movement control test battery and the resulting diagnosis in patients with nonspecific chronic low back pain

ABSTRACT Objective To investigate the intrarater and interrater agreement of a 6-item test battery in nonspecific chronic low back pain (LBP) and investigate the agreement between raters to assign the resulting movement control (MC) diagnoses. Methods Thirty patients with chronic LBP (18–30 years) were included in this study. Six raters were trained and rated the videos of the patients during the execution of the tests. After one week, the raters re-watched the videos and repeated the examination. A diagnosis of MC was assigned for each patient. Agreement was analyzed using weighted kappa and prevalence-adjusted and bias-adjusted kappa (PABAK) coefficients. Results We showed an acceptable intrarater agreement for the 6-item test battery for four out of six raters, except for one test: prone knee flexion. The results of the interrater agreement between the three pairs of raters showed acceptable agreement levels (k > 0.4), except for two tests, “rocking on all four backward” and “prone knee flexion test.” For the diagnosis of MC impairment, acceptable agreement levels (k > 0.4) were observed for five out of six raters for intrarater agreement. For interrater assessment, we found an acceptable agreement between pairs of raters. Conclusion We showed acceptable levels of agreement between the intrarater and interrater for a 6-item test battery to identify MC impairment, except for two tests. Agreement in the MC diagnoses achieved acceptable levels for five of the six raters (intrarater) and all three pairs of raters (interrater). Such results support the use of the 6-item test battery to detect MC impairment.

Word Fluency Test (WFT): A parallel FAS alternative

The capacity to quickly verbalize words beginning with a specific letter is integral in assessing language skills as well as an essential part of a comprehensive neuropsychological assessment. Using the letters F, A, S as a word fluency measure is limited by having no direct parallel alternative that can use the same F, A, S norms. This observational and cross-sectional study examined the correlation between the Word Fluency Test (WFT), utilizing letters M, D, H, as a parallel alternative to the clinical standard F, A, S to determine if the two are equivalent. This would allow for the use of existing F, A, S norms. Study participants (N = 356) were comprised of both adult control participants and out-patients with normal neuropsychological test results. Between-group differences for both task performances were not statistically significant indicating that patients and controls performed similarly on each of the six letters. Between-letter correlations were moderate in strength indicating an acceptable level of agreement between all of the letters. The results confirm equivalency and support administering the WFT and employing F, A, S norms offering a corresponding parallel alternative measure with strong correlation indicating high level of agreement.

Validation and reproducibility of a semi-qualitative food frequency questionnaire for assessment of sodium intake in Iranian population

BackgroundFew semi-quantitative food frequency questionnaires (SFFQ)s has yet been developed to assess sodium intake in Middle East region. This study was performed to validate a SFFQ for assessment of sodium consumption and food groups΄ contribution to sodium intake.MethodsThis study was performed on 219 healthy participants including 113 adults aged ≥19 years and 106 children aged 6–18 years in Isfahan, Iran. They were administered two SFFQ at the beginning and after 1 year to evaluate the reproducibility. The validity of SFFQ for assessment of sodium intake was compared with 24-h urine sodium and twelve 24-h dietary recalls which were completed monthly during a year as two standard methods.ResultsCorrelation coefficient between the contribution of food groups to sodium intake based on SFFQ and 24-h dietary recalls varied from 0.04 for legumes (P = 0.667) to 0.47 for added salt (P < 0.001). There was a significant correlation between the estimated total sodium intake based on SFFQ and both standard methods (P < 0.01). Intraclass correlation coefficient (95% CI) between first and second SFFQ had a diverse range from 0.10 (-0.05, 0.17) for fats and oils to 0.49 (0.28, 0.69) for bread. According to the Bland-Altman plots, we observed an acceptable level of agreement between the two methods for sodium intake.ConclusionsThe SFFQ was a relatively valid and reproducible method for estimating sodium intake. Combination of this SFFQ with a valid prediction of 24-h urinary sodium excretion can be useful in achieving more accurate results.

Linguistic and cultural adaptation of physical activity readiness questionnaire in Odia language

Background: Regular exercise and proper exercise are two important measures that can control obesity reduce the chances of metabolic disease and promote a healthy life. Many a time, exercise may not be suitable for some individuals. For screening, a Physical Activity Readiness Questionnaire (PAR-Q) is used. However, it is not available in Odia, a language spoken in Odisha, India. Aim and Objective: This study aimed to adapt the PAR-Q linguistically in Odia according to guidelines laid by the World Health Organization. Materials and Methods: The English questionnaire was forward translated from English to Odia by three bilingual experts and a consensus was reached to make a final Odia version. Then, the Odia version was back-translated to English by three language experts and a consensus was reached to form a final back-translated version. Then, the conceptual equivalence was checked between the two versions for finalizing the Odia version. Then, the questionnaire was pre-tested and cognitive interview was conducted. Results: We have successfully forward translated and back-translated the PAR-Q. The Odia version and back-translated English version showed an acceptable level of equivalence by two individual raters with an acceptable level of agreement. The Odia PAR-Q was successfully pre-tested. Conclusion: We have linguistically translated the PAR-Q in Odia. This questionnaire can be used for screening individuals for their fitness for enrolling and engaging in exercise. This questionnaire would help sports authorities as well as paramedical staff in screening Odia speaking subjects who are not comfortable with English.

Validation Principles of Agricultural Machine Multibody Dynamics Models

HighlightsThis study focused on proper validation methodology for agricultural machine multibody dynamic models.Experimental design included categorizing subsystems, data acquisition, testing, and data pre-processing.Three error quantification metrics are proposed to summarize model performance and overall agreement.Abstract. Multibody dynamic (MBD) models are required to be accurate if they are to be used with confidence. To determine the overall accuracy of an agricultural machine MBD model, the model needs to be validated through proper experimental design principles and error analysis. At a high-level, the main methodology concepts for the experimental design involve categorizing dynamic subsystems, creating a data acquisition plan, determining and completing experimental testing, and pre-processing of physical and virtual time series datasets. This paper provides a methodology and example validation process for an MBD model of an agricultural self-propelled sprayer. As part of the experimental testing, a tip test revealed that the vertical center of gravity of the MBD model resulted in a 2.8% error from the physical machine. Furthermore, to summarize simulation model performance against physical data, three error quantification metrics for time-series data comparison are proposed: (1) correlation coefficient, (2) two-sample t-test and two-sample F-test, and (3) standard deviation of absolute error. For determining whether there is an acceptable level of agreement, this study proposes that the correlation coefficient should be greater than 0.7, the two-sample t-test and two-sample F-test should both pass (but with special consideration of the resulting confidence intervals if they fail), and that the standard deviation of absolute error should be less than 25% of the standard deviation of physical time series data. These error metrics, together with their defined sets of agreement criteria, resulted in detecting where the self-propelled sprayer system was experiencing validation issues and eventually the overall practical validation of the MBD model. Keywords: Agricultural machines, Confidence, Error metrics, Models, Multibody dynamics (MBD), Simulation, Validation.

The reliability and validity of triceps surae muscle volume assessment using freehand three-dimensional ultrasound in typically developing infants.

This study assessed the intra-acquirer, intra- and inter-processor reliability, and validity of the in vivo assessment of the medial gastrocnemius (MG), lateral gastrocnemius (LG) and soleus (SOL) muscle volumes using freehand 3D ultrasound (3DUS) in typically developing infants. Reliability assessments of freehand 3DUS were undertaken in infants across three ages groups: three, six and twelve months of age, with validity testing completed against magnetic resonance imaging (MRI) in infants at 3months of age. Freehand 3DUS scanning was carried out by a single acquirer, with two independent processors manually segmenting images to render volumes. MRI images were segmented independently by a separate processor, with the volumes compared to those obtained via freehand 3DUS. Reliability was assessed using intraclass correlation (ICC), coefficient of variance (CV) and minimal detectable change (MDC) across each assessment time point. Validity was assessed using the limits of agreement. ICCs for intra-acquirer reliability of the acquisition process for freehand 3DUS ranged from 0.91 to 0.99 across all muscles. ICCs for intra-processor and inter-processor reliability for the segmentation process of freehand 3DUS ranged from 0.80 to 0.98 across all muscles. Acceptable levels of agreement between muscle volume obtained by freehand 3DUS and MRI were found for all muscles; however, freehand 3DUS overestimated muscle volume of MG and LG and underestimate the SOL compared with MRI, with average absolute differences of MG=0.3ml, LG=0.3ml and Sol=1.2ml. Freehand 3DUS is a reliable method for measuring in vivo triceps surae muscle volume in typically developing infants. We conclude that freehand 3DUS is a useful tool to assess changes in muscle volume in response to growth and interventions in infants.

Discrepancies between self-reported and device-measured sleep parameters in adults with multiple sclerosis.

Sleep problems are a common consequence of multiple sclerosis; however, there is limited evidence regarding the agreement between device-measured and self-reported sleep parameters in adults with multiple sclerosis. The present study examined the agreement between self-reported and device-measured parameters of sleep quality in a sample of adults with multiple sclerosis. Participants (n = 49) completed a 7-day sleep diary and wore a wrist-worn ActiGraph GT3×+ (ActiGraph Corp., Pensecola, FL) for seven consecutive nights to quantify self-reported and device-measured sleep parameters, respectively. There was a significant discrepancy between self-reported and device-measured parameters of total time in bed (mean difference = 19.8 [51.3] min), sleep onset latency (mean difference = 22.2 [19.5] min), and frequency of awakenings during the night (mean difference = 12.8 [6.8]). Intraclass correlation estimates indicated poor agreement between methods on most parameters, except for total time in bed (intraclass correlation = 0.80). Bland-Altman plots suggested that total time in bed and total sleep time had acceptable levels of agreement and linear regression analyses indicated that sleep onset latency (F = 113.91, B = -1.34, P < .001), number of awakenings (F = 543.34, B = 1.85, P < .001), and sleep efficiency (F = 18.39, B = -0.77, P < .001) had significant proportional bias. Our results draw attention to the discrepancies between sleep parameter measurements and highlight the importance of including both self-report and device-measured outcomes for a complete and accurate representation of sleep in adults with multiple sclerosis. Cederberg KLJ, Mathison BG, Schuetz ML, Motl RW. Discrepancies between self-reported and device-measured sleep parameters in adults with multiple sclerosis. J Clin Sleep Med. 2022;18(2):415-421.

Pulse wave velocity in South African women and children: comparison between the Mobil-O-Graph and SphygmoCor XCEL devices.

Background:Carotid-femoral pulse wave velocity (PWV) is the gold-standard noninvasive measure of arterial stiffness. Data comparing tonometry-based devices such as the SphygmoCor XCEL to simpler brachial-cuff-based estimates of PWV, such as from the Mobil-O-Graph in African populations are sparse. We therefore aimed to compare PWV measured by the Mobil-O-Graph and the SphygmoCor XCEL device in a sample of South African women and children.Methods:Women (n = 85) 29 years [interquartile range (IQR): 29–69] and their children/grandchildren (n = 27) 7 years (IQR: 4–11) were recruited for PWV measurement with Mobil-O-Graph and SphygmoCor XCEL on the same day. Wilcoxon signed-rank test, regression analysis, spearman correlation and Bland–Altman plots were used for PWV comparison between devices.Results:For adults, the SphygmoCor XCEL device had a significantly higher PWV (7.3 m/s, IQR: 6.4–8.5) compared with the Mobil-O-Graph (5.9 m/s, IQR: 5.0–8.1, P = 0.001) with a correlation coefficient of 0.809 (P ≤ 0.001). Bland--Altman analysis indicated an acceptable level of agreement but significant bias (mean difference PWV: 0.90 ± 1.02 m/s; limits of agreement: −1.10 to 2.90). The odds of having a PWV difference more than 1 m/s decreased with a higher age [odds ratio (OR): 0.95, 95% confidence interval (95% CI) = 0.92–0.98] and increased with greater height (OR: 1.10, 95% CI = 1.01–1.21, P = 0.03) in multivariable analysis. In children, the Bland–Altman indicated an excellent level of agreement (−0.03 ± 0.63 m/s; limits of agreement: −1.26 to 1.21), but no correlation was found (rs = 0.08, P = 0.71).Conclusion:Particularly in younger and taller women, the Mobil-O-Graph significantly underestimated PWV compared with the SphygmoCor. Although no correlation was found between the two devices for children, further research is required due to the small sample size. Furthermore, the clinical value of both methods in young African populations requires further investigation.

Comparison of CBNAAT and conventional real time RT PCR for HIV 1 viral load testing

PurposeHIV viral load testing is now recommended for monitoring of anti-retroviral treatment failure in PLHIV. Xpert® HIV-1 Viral Load is a fully automated CB-NAAT. A reduced turnaround time leads to prompt clinical management. Hence the current study was undertaken to compare Xpert® HIV-1 Viral Load with the routinely used conventional real time RT PCR. MethodsThe study was conducted in the Department of Microbiology of a tertiary care medical college after ethics committee approval. 100 HIV positive samples were tested by both CB-NAAT and conventional real time RT PCR for HIV 1 viral load. Results were analyzed using Spearman's correlation co-efficient and Bland Altman plot for agreement. The number of samples with inter assay differences in viral loads exceeding 0.5 log copies/ml was also recorded. The sensitivity, specificity, PPV and NPV as well as the possible misclassification were calculated at the clinically significant value of 1000 copies/ml. Results25 samples in each of the four groups with log 10 value of <3, 3 to <4, 4 to <5 and ≥5 respectively were included. The log difference between the groups varied from 0 to 1.54. CB-NAAT has shown a statistically significant correlation with conventional real time RT PCR by Spearman's rank correlation (R = 0.972) (P < 0.01) and acceptable level of agreement with Bland Altman plot. The sensitivity, specificity, PPV, NPV and diagnostic accuracy was 80%, 100%, 100%, 93.75% and 95% respectively. The overall concordance was 95% with an upward misclassification of 6.25% and downward misclassification of 0%. ConclusionsPoint of care technology with sample in/answer out approach makes it an excellent choice especially in resource constrained and remote settings.

Validation of the FRESH Austin food frequency questionnaire using multiple 24-h dietary recalls.

The purpose of the current study was to examine the validity of an FFQ utilised in the Food Retail: Evaluating Strategies for a Healthy Austin (FRESH Austin) study, designed to evaluate changes in the consumption of fruits and vegetables (FV) in diverse low-income communities in Austin, TX. The FRESH Austin FFQ was validated against three 24-h dietary recalls (24hDR). All dietary assessments were administered (in-person or by telephone) by trained investigators. Recruitment was conducted at sites within the geographic areas targeted in the FRESH Austin recruitment. People at a community health clinic, a local health centre and a YMCA within the intervention area were approached by trained and certified data collectors, and invited to participate. Among fifty-six participants, 83 % were female, 46 % were non-White, 24 % had income < $25 K/year and 30 % spoke only/mostly Spanish at home. The FFQ and average of three 24hDR produce similar estimates of average total servings/d across FV (6·68 and 6·40 servings/d, respectively). Correlations produced measures from 0·01 for 'Potatoes' and 0·59 for 'Other Vegetables'. Mean absolute percentage errors values were small for all FV, suggesting the variance of the error estimates was also small. Bland-Altman plots indicate acceptable levels of agreement between the two methods. These outcomes indicate that the FRESH FFQ is a valid instrument for assessing FV consumption. The validation of the FRESH Austin FFQ provides important insights for evaluating community-based efforts to increase FV consumption in diverse populations.

Experimental and numerical investigation on the heat transfer of an automotive engine’s turbocharger

Measuring the temperature distribution in a complex and important engine part, such as a turbocharger, is essential for improving engine performance and efficiency. Heat transfer from the turbine to the compressor can strongly influence the turbocharger performance. One of the main measurement methods involves the installation of multiple K-type sensors. However, the location as well as the maximum and minimum temperatures of the turbocharger and the subsequent critical points may not be obtained by using sensors. In the current study, thermocouples, as well as an infra-red camera, are used to study the temperature distribution of the turbocharger housing in a spark ignition engine. A new method is introduced to determine the thermal radiation coefficient of the turbocharger housing by using a laboratory furnace and an infra-red camera. Together with experiments, the finite element method is used to find the temperature distribution in the turbocharger for all thicknesses. Comparing the temperature distribution obtained from simulation with experimental data, an acceptable level of agreement is observed. The location and temperature of the hottest area in experimental and numerical investigations are close to the waste gate. Temperatures using the finite element method for bearings exhibit maximum and minimum errors of 4.9% and 2.3%, respectively, indicating reasonable accuracy for the simulation.