Measurement Interval Research Articles

Performance evaluation of a novel reticulocyte identification method that uses metachromatic nucleic acid staining based on a crossover analysis of emission DNA/RNA light (RNP Determination™) in hematology analyzer Celltac G.

Assessing the percentage of reticulocytes (%Retic) is useful for diagnosing and treating blood diseases that present with anaemia. The Celltac G+™ hematology analyzer (HA) uses a novel reticulocyte identification method that involves metachromatic nucleic acid staining with acridine orange and crossover analysis of emission light of DNA/RNA (determination of red cells, nucleic acid-containing cells, and platelets, RNP Determination™). The red and green fluorescence generated by stained single-stranded RNA and double-stranded DNA express immaturity and morphological abnormality of erythrocytes by detecting erythrocyte RNA and DNA content. The basic performance of the test automated analyzer (TAA) Celltac G+ was evaluated and compared with the flow cytometry reference method and the comparative automated analyzer (CAA) XN-1000/2000™. In addition, its precision, limit of quantity (LoQ), linearity, analytical measurement interval (AMI), accuracy, and comparability and the effects of interfering substances were evaluated. Evaluation of %Retic by the TAA demonstrated good precision and linearity. The AMI was confirmed from 0.02 to 8.23, and the LoQ in %Retic as the coefficient of variation within an 11% limit (SD, within a 0.01 limit) was 0.14. TAA correlated well with the reference method and routine HA (CAA). Some deviations were found between TAA and CAA in DNA measurements of erythrocytes from abnormal samples. Celltac G+ uses a novel measurement principle and can assess erythrocyte immaturity independent of DNA contents. It represents a new HA that provides novel, useful information on immaturity and morphological abnormality of erythrocytes.

Non-Fasting Hypertriglyceridemia Burden as a Residual Risk of the Progression of Carotid Artery Stenosis.

The relationships between repeated non-fasting triglyceride (TG) measurements and carotid stenosis progression during follow-ups have never been investigated. In 111 consecutive carotid arteries of 88 patients with ≥50% atherosclerotic stenosis on at least one side, who had ≥3 blood samples taken during ≥one-year follow-ups, clinical variables were compared between carotid arteries with and without subsequent stenosis progression. To evaluate non-fasting TG burden, a new parameter area [TG ≥ 175] was calculated by integrating non-fasting TG values ≥ 175 mg/dL (i.e., TG values minus 175) with the measurement intervals (year). Carotid stenosis progression occurred in 22 arteries (19.8%) during the mean follow-up period of 1185 days. Younger age, symptomatic stenosis, higher mean values of TG during follow-ups, the area [TG ≥ 175], mean TG values ≥ 175 mg/dL and maximum TG values ≥175 mg/dL were significant factors related to the progression on univariate analyses. The cut-off value of the area [TG ≥ 175] to discriminate carotid stenosis progression was 6.35 year-mg/dL. Multivariate analyses demonstrated that symptomatic stenosis and the area [TG ≥ 175] ≥ 6.35 year-mg/dL were independently related to carotid stenosis progression. In conclusion, the area [TG ≥ 175] was an independent risk factor for carotid stenosis progression, and this study suggests the importance to continuously control non-fasting TG levels < 175 mg/dL during follow-ups to prevent carotid stenosis progression.

Bayesian Simultaneous Credible Intervals for Effect Measures from Multiple Markers

Inference from multiple markers is often encountered in biomedical research, especially when comparing treatments. Most common statistical methods rely on hypothesis testing with null hypothesis of no effect for each marker and methods based on closed testing for getting the combined p-value. This article proposes the use of simultaneous credible intervals obtained from the joint posterior distribution of effect measures of multiple markers for combined inference. The advantage of this method is that it finds the actual effect sizes and also allows different types of effect measures for various markers. We used equal tailed intervals and highest posterior density regions for effect measures of multiple markers. Simulation studies were carried out to examine frequentist properties of these simultaneous credible regions. These studies revealed that the inference based on simultaneous intervals can be different than the inference based on individual marker. The method is demonstrated through two case studies: (a) an observational study of wet age-related macular degeneration (wet-AMD); and (b) reanalysis of a randomized controlled trial for treatment of migraine. The wet-AMD observational study was the motivation for the present research.

Nonpharmacological Cognitive Impairment Prevention Interventions in Older Adults Undergoing Cardiac Surgery: A Systematic Review.

More than 1 million individuals undergo cardiothoracic surgery for coronary artery bypass graft or valve repair/replacement annually in the United States. There is an increased risk of developing serious cognitive impairment post cardiothoracic surgery. Pharmacological interventions and surgical techniques were associated with improvements in cognitive function in previous systematic reviews. However, a gap in the literature exists regarding how nonpharmacological interventions can mitigate cognitive impairment in adults undergoing cardiac surgery. The aim of this study was to explore the effectiveness of nonpharmacological interventions to reduce the detrimental effects of cardiac surgery on cognitive function in patients after cardiothoracic surgery. CINAHL, MEDLINE, PubMed, EMBASE, PsycINFO, and Web of Science databases were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines from January 2011 to February 2022. Nineteen studies were included in this review. Researchers defined cognitive impairment differently across studies. Various interventions were used to reduce cognitive impairment post cardiothoracic surgery, with the most common being remote ischemic limb conditioning. The interventions used to reduce cognitive impairment were heterogeneous in outcomes, measurements, and time of assessment, but only 2 interventions were associated with a reduction in cognitive impairment. This review is a unique synthesis of the quality of interventions that address broader components of cognition. Researchers used various interventions to reduce cognitive impairment; the outcomes, instruments, and time interval for measurements were heterogeneous. Researchers should conduct future studies at multiple time intervals, using a comprehensive measure of cognitive impairment to better understand the impact of cognitive impairment interventions postoperatively.

How to avoid errors when computing reference interval tables and graphs using regression equations for cross-sectional studies of fetal biometry.

While visualization of fetal anatomy is one of the primary purposes of diagnostic ultrasound, the application of statistical analysis to biological measurements of fetal structures such as the head, abdomen, long bones, and heart, requires equations that compute changes in these measurements over time. One of the challenges for the investigator who desires to compute reference intervals for a fetal measurement is selecting the best equation for the measurements of interest. Fractional polynomial regression equations have been used to describe changes in fetal measurements over time and consists of 44 equations for the investigator to select. Since it would be laborious to analyze each equation to identify the best fit of the data, software programs have been developed for such analysis. However, depending upon the software program, potential errors can occur when translating the coefficients of a complex equation to a format that can be used by the clinician to create reference interval tables and graphs. This study reviews the requirements for statistical output that allows the investigator to generate reference interval tables and graphs using Excel. A step-by-step sequence is explained that enables the investigator to minimize the possibility of errors when reporting complex equations and their associated graphs that result from fractional polynomial regression analysis. Using the techniques described in this opinion paper should decrease the potential for reporting erroneous equations used to compute reference interval tables and graphs. This article is protected by copyright. All rights reserved.

Experimental assessment of the similarity law for a heat conduction problem

Similarities are mathematical laws, which are based on the dimensionless formulation of the governing equation of a physical phenomenon. Consequently, a set of characteristic dimensionless numbers is obtained. Similarities aim, via these numbers, to find equivalences between particular configurations. This approach is widely adopted, especially in fluid and aerodynamic problems. In the building context, the phenomena of heat and mass transfer in porous media occur with slow kinetics. Thus, similarities can be employed to reduce the duration of experimental campaigns to characterize material properties. These laws were investigated here in the case of a heat transfer problem through an experimental campaign. Two equivalent configurations were submitted to a heat stress. Temperatures inside materials were measured and compared to assess the validity of thermal similarity. A complete evaluation of uncertainty propagation was then carried out. Uncertainties related to the sensor position, its response time, the omission of mass transfer, the sensor systematic accuracy, the random measurement aspect, the one-dimensional transfer hypothesis and the boundary condition modeling were evaluated. The comparison of both configurations was carried out based on the confidence interval of both measurements. The results showed a good agreement between the reference and reduced experiment. On the basis of these findings, similarities were experimentally verified within a margin of discrepancy that was justified. Thus, they can be adopted in heat transfer experiments in order to identify equivalent configurations that are easier to conduct.

Parameter estimation for grouped data using EM and MCEM algorithms

Nowadays, the confidentiality of data and information is of great importance for many companies and organizations. For this reason, they may prefer not to release exact data, but instead to grant researchers access to approximate data. For example, rather than providing the exact measurements of their clients, they may only provide researchers with grouped data, that is, the number of clients falling in each of a set of non-overlapping measurement intervals. The challenge is to estimate the mean and variance structure of the hidden ungrouped data based on the observed grouped data. To tackle this problem, this work considers the exact observed data likelihood and applies the Expectation-Maximization (EM) and Monte Carlo EM (MCEM) algorithms for cases where the hidden data follow a univariate, bivariate, or multivariate normal distribution. Simulation studies are conducted to evaluate the performance of the proposed EM and MCEM algorithms. The well-known Galton data set is considered as an application example.

Measured weight loss as a precursor to cancer diagnosis: retrospective cohort analysis of 43302 primary care patients.

BackgroundUnexpected weight loss is a presenting feature of cancer in primary care. Data from primary care are lacking to quantify how much weight loss over what period should trigger further investigation for cancer. This research aimed to quantify cancer diagnosis rates associated with measured weight change in people attending primary care.MethodsRetrospective cohort study of primary care electronic health records data linked to the Surveillance, Epidemiology, and End Results cancer registry (Integrated healthcare delivery system in Washington State, United States). Multivariable Cox regression incorporating time varying covariates using splines to model non‐linear associations (age, percentage weight change, and weight change interval). Fifty thousand randomly selected patients aged 40 years and over followed for up to 9 years (1 January 2006 to 31 December 2014). Outcome measures are hazard ratios (95% confidence intervals) to quantify the association between percentage weight change and cancer diagnosis for all cancers combined, individual cancer sites and stages; percentage risk of cancer diagnosis within 6 months of the end of each weight change episode; and the positive predictive value for cancer diagnosis.ResultsThere were 43 302 included in the analysis after exclusions. Over 287 858 patient‐years of follow‐up, including 24 272 (56.1%) females, 23 980 (55.4%) aged 40 to 59 years, 15 113 (34.9%) 60 to 79 years, and 4209 (9.7%) aged 80 years and over. Adjusted hazard ratios (95% confidence interval) for cancer diagnosis in a 60 years old ranged from 1.04 (1.02 to 1.05, P < 0.001) for 1% weight loss to 1.44 (1.23 to 1.68, P < 0.001) for 10%. An independent linear association was observed between percentage weight loss and increasing cancer risk. The absolute risk of cancer diagnosis increased with increasing age (up to 85 years) and as the weight change measurement interval decreased (<1 year). The positive predictive value for a cancer diagnosis within 1 year of ≥5% measured weight loss in a 60 to 69 years old was 3.41% (1.57% to 6.37%) in men and 3.47% (1.68% to 6.29%) in women. The risk of cancer diagnosis was significantly increased for pancreatic, myeloma, gastro‐oesophageal, colorectal, breast, stage II and IV cancers.ConclusionsWeight loss is a sign of undiagnosed cancer regardless of the interval over which it occurs. Guidelines should resist giving an arbitrary cut‐off for the interval of weight loss and focus on the percentage of weight loss and the patient's age. Future studies should focus on the association between diagnostic evaluation of weight change and risk of cancer mortality.

Systolic blood pressure trajectories after acute ischemic strokes and clinical outcomes: A systematic review.

Blood pressure(BP) varies drastically during the acute phase after stroke onset. BP level and BP variability may have a major impact on acute ischemic stroke (AIS) prognosis. However, the association between trajectories of blood pressure over time and clinical outcomes have not been established. This review sought out existing evidences for associations of systolic blood pressure (SBP) trajectories on outcomes after stroke to determine the connection between SBP trajectories and stroke prognosis. According to a pre‐designed search strategy, literature search was carried out in Embase, Pubmed and Web of Science. Two authors independently evaluated study eligibility and quality, and literature data were extracted. When the literature was eligible, we perform meta‐analysis to determine associations of SBP trajectories with clinical outcomes. Seven studies were finally screened out of 52 studies retrieved. Seven studies received a good risk of bias rating and reported BP measurement methods and intervals, BP trajectories modeling methods, outcome measures, but it was found that final systolic BP trajectories in various papers were significantly different. All studies reported statistically significant associations between systolic blood pressure trajectories and prognosis. Methodological heterogeneity is observed in studies. However, this systematic review suggests that the high SBP group after AIS is related to poor clinical outcomes, while the rapid decline or medium‐to‐low or low SBP group is associated with relatively better clinical outcomes at different period after stroke. More prospective studies are needed to report the full methodology according to standardized criteria and explore relationships between SBP trajectories and prognosis of stroke.

Investigation of variation factors in EMG measurement of swallowing: instruction can improve EMG reproducibility.

Variability in swallowing electromyography (EMG) has been reported to occur due to individual differences, even in studies with appropriate control of factors affecting EMG such as food type, properties, and posture. The increased variability broadens the confidence intervals of measures obtained from EMG, such as time and amplitude, and makes it difficult to detect differences in muscle activity. This makes it impossible to detect slight changes in swallowing function at an early stage, which is required for clinical examination. In this study, we focused on the tipper type and dipper type of oral swallows, which differ in the timing of muscle activity. The frequency of occurrence of both types varies between participants, and both types could occur in the same participant. In this study, we measured swallowing EMG wherein participants were instructed to swallow with a tipper and a dipper. The results showed that there was a significant difference in the between-participant duration between these two types of swallows. Within-participant variability was significantly lower in the tipper-dipper instruction condition compared to the baseline condition, which assumed a mixture of tipper-dipper swallowing. These results demonstrate that instructions on swallowing method are effective in improving the reproducibility of EMG.

Game Theory and an Improved Maximum Entropy-Attribute Measure Interval Model for Predicting Rockburst Intensity

To improve the accuracy of predicting rockburst intensity, game theory and an improved maximum entropy-attribute measure interval model were established. First, by studying the mechanism of rockburst and typical cases, rock uniaxial compressive strength σc, rock compression-tension ratio σc/σt, rock shear compression ratio σθ/σc, rock elastic deformation coefficient Wet, and rock integrity coefficient Kv were selected as indexes for predicting rockburst intensity. Second, by combining the maximum entropy principle with the attribute measure interval and using the minimum distance Di−k between sample and class as the guide, the entropy solution of the attribute measure was obtained, which eliminates the greyness and ambiguity of the rockburst indexes to the maximum extent. Third, using the compromise coefficient to integrate the comprehensive attribute measure, which avoids the ambiguity about the number of attribute measure intervals. Fourth, from the essence of measurement theory, the Euclidean distance formula was used to improve the attribute identification mode, which overcomes the effect of the confidence coefficient taking on the results. Moreover, in order to balance the shortcomings of the subjective weights of the Analytic Hierarchy Process and the objective weights of the CRITIC method, game theory was used for the combined weights, which balances experts’ experience and the amount of data information. Finally, 20 sets of typical cases for rockburst in the world were selected as samples. On the one hand, the reasonableness of the combined weights of indexes was analyzed; on the other hand, the results of this paper’s model were compared with the three analytical models for predicting rockburst, and this paper’s model had the lowest number of misjudged samples and an accuracy rate of 80%, which was better than other models, verifying the accuracy and applicability.

Endodontic working length measurements of premolars and molars in high-resolution dental MRI: a clinical pilot study for assessment of reliability and accuracy

ObjectivesTo prospectively assess the reliability and accuracy of high-resolution, dental MRI (dMRI) for endodontic working length (WL) measurements of premolars and molars under clinical conditions.Materials and methodsThree-Tesla dMRI was performed in 9 subjects who also had undergone cone-beam computed tomography (CBCT) (mean age: 47 ± 13.5 years). A total of 34 root canals from 12 molars (4/8, upper/lower jaw; 22 root canals) and 11 premolars (2/9 upper/lower jaw; 12 root canals) were included. CBCT and dMRI datasets were reconstructed to visualize the root canal in one single slice. Subsequently, two radiologists measured the root canal lengths in both modalities twice in blinded fashion. Reliability and accuracy for both modalities were assessed using intraclass correlation coefficients (ICCs) and Bland–Altman analysis, respectively.ResultsReliability (intra-rater I/II; inter-rater) of dental MRI measurements was excellent and comparable to CBCT for premolars (0.993/0.900; 0.958 vs. 0.993/0.956; 0.951) and for molars (0.978/0.995; 0.986 vs. 0.992/0.996; 0.989). Bland–Altman analysis revealed a mean underestimation/bias (95% confidence interval) of dMRI measurements of 0.8 (− 1.44/3.05) mm for premolars and 0.4 (− 1.55/2.39) mm for molars. In up to 59% of the cases, the accuracy of dMRI for WL measurements was within the underestimation margin of 0 to 2 mm short of the apical foramen AF.ConclusionsIn vivo demonstration and measurement of WL are feasible using dMRI. The reliability of measurements is high and equivalent to CBCT. Nonetheless, due to lower spatial resolution and longer acquisition time, the accuracy of dMRI is inferior to CBCT, impeding its current use for clinical treatment planning.Clinical relevancedMRI is a promising radiation-free imaging technique. Its reliability for endodontic working length measurements is high, but its accuracy is not satisfactory enough yet.

Alignment Efficiency of Nickel-Free Niobium–Titanium–Tantalum–Zirconium Compared to Nickel–Titanium Orthodontic Archwires during Initial Treatment Phase: A Randomized Controlled Trial

Abstract Objective This randomized controlled trial investigated the efficiency of nickel–titanium (NiTi) and nickel-free archwires during the initial leveling and alignment stage. Materials and Methods A total of 30 patients (mean age, 17.81 ± 1.96 years) were randomly grouped to receive either single-strand or niobium–titanium–tantalum–zirconium (nickel-free Gummetal), or multistrand NiTi archwires. All the patients had moderate anterior crowding and were treated via a nonextraction approach. Three-dimensional digital models were taken at baseline (T0) and 4-week intervals for three months (T1, T2, and T3). The amount and percentage variations in Little's Irregularity Index (LII) scores during the 3-month observation period were used to estimate alignment efficiency and rate. Statistical Analysis The Analysis of variance (ANOVA) and Kruskall–Wallis tests were used to test the differences between the three archwire groups. The difference between variables within each group at different measurement intervals was assessed using paired t-test. Results The LII scores were reduced in all the three archwire groups; however, there were insignificant differences in the scores between the tested archwire groups (p &lt; 0.05). For the single-strand NiTi group, the LII scores reduced by 2.15 mm (28.38%) after 4 weeks (T1) by 3.79 mm (47.93%) after 8 weeks (T2), and by 5.61 mm (73.98%) after 12 weeks (T3). The LII scores decreased by 1.90 mm (26.93%) after 4 weeks, 3.59 mm (50.84%) after 8 weeks, and 5.28 mm (74.85%) after 12 weeks with Gummetal archwire. Similar to the other groups, the LII scores for multistrand archwire reduced by 1.82 (27.83%), 3.34 (51.07%), and 4.54 mm (69.38%) at T1, T2, and T3, respectively. There was nonsignificant differences in the alignment rates (mm) and percentage (%) of changes among the groups at all measurement intervals (p &gt; 0.05). Conclusion All three tested archwires were equally effective for correcting moderate mandibular anterior crowding. Furthermore, all three archwires produced a comparable rate of alignment after 12 weeks of initiating orthodontic therapy.

Optimal Number of Clusters by Measuring Similarity Among Topographies for Spatio-Temporal ERP Analysis.

Averaging amplitudes over consecutive time samples (i.e., time window) is widely used to calculate the peak amplitude of event-related potentials (ERPs). Cluster analysis of the spatio-temporal ERP data is a promising tool to determine the time window of an ERP of interest. However, determining an appropriate number of clusters to optimally represent ERPs is still challenging. Here, we develop a new method to estimate the optimal number of clusters utilizing consensus clustering. Various polarity dependent clustering methods, namely, k-means, hierarchical clustering, fuzzy c-means, self-organizing map, spectral clustering, and Gaussian mixture model, are used to configure consensus clustering after assessing them individually. When a range of clusters is applied many times, the optimal number of clusters should correspond to the expectation, which is the average of the obtained mean inner-similarities of estimated time windows across all conditions and groups converge in the satisfactory thresholds. In order to assess our method, the proposed method has been applied to simulated data and prospective memory experiment ERP data aimed to qualify N2 and P3, and N300 and prospective positivity components, respectively. The results of determining the optimal number of clusters meet at six cluster maps for both ERP data. In addition, our results revealed that the proposed method could be reliably applied to ERP data to determine the appropriate time window for the ERP of interest when the measurement interval is not accurately defined.

The Effect of Sunnah Fasting on Blood Pressure and Oral Hygiene Level

The Monday-Thursday fasting, as one of the sunnah highly recommended by Rasulullah, can be a key to maintaining health. This research aims to determine the difference in blood pressure and oral health among the santriwati in Madrasah Mu’allimat Muhammadiyah Yogyakarta who have gotten used to doing and those who have not gotten used to doing Monday-Thursday fasting. It is an observational quantitative research using a cross-sectional design. They were 48 santriwati of 14-18 years old as subjects. Blood pressure was measured thrice with a minimum measurement interval of 15 minutes. The dental and oral hygiene level was obtained using the OHI-S measurement index. The students who habitually carried out sunnah fasting had a normal blood pressure of 20.8% (of a total of 27.1%), and all students had a good level of OHI (27.1%). Meanwhile, among students who are not accustomed to fasting, 45.8% had abnormal blood pressure (a total of 72.9%), and the good level of OHI was only 47.9%. The analysis of Mann-Whitney data showed a significant value for the blood pressure category variable of 0.015 and the OHI-S category of 0.015. The significance level of p 0.05 for each measurement variable (blood pressure and OHI-S categories) illustrated that there were differences in blood pressure and oral hygiene among the santriwati who had gotten used to doing and those who had not gotten used to doing Monday-Thursday fasting.

Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL): high-resolution in situ observations and modeling in and above the nocturnal boundary layer

Abstract. The Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL) program was conceived to improve understanding of the dynamics of thin strongly stratified “sheet” and deeper weakly stratified “layer” (S&amp;amp;L) structures in the lower troposphere under strongly stable conditions. The field portion of the IDEAL program was conducted from 24 October to 15 November 2017 at Dugway Proving Ground, Utah, to target nighttime lower troposphere S&amp;amp;L conditions. It employed a synergistic combination of observations by multiple simultaneous DataHawk-2 (DH2) small unmanned aircraft systems (sUASs) and concurrent ground-based profiling by the NCAR Earth Observing Laboratory Integrated Sounding System (ISS) comprising a wind profiler radar and hourly high-resolution radiosonde soundings. DH2 measurement intervals as well as vertical (∼ 2–4 km) and horizontal (∼ 5–10 km) flight trajectories were chosen based on local high-resolution weather forecasting and guided by near-real-time ISS measurements. These flights combined simultaneous vertical and slant-path profiling, and/or horizontal racetrack sampling, spanning several hours before sunrise. High-spatial- and temporal-resolution data were downlinked in real time to enable near-real-time changes in DH2 flight paths based on observed flow features. The IDEAL field program performed 70 DH2 flights on 16 d, coordinated with 93 high-resolution radiosonde soundings. In this paper, raw and derived measurements from this campaign are outlined, and preliminary analyses are briefly described. This data set, along with “quick look” figures, is available for access by other researchers, as described herein.

The reciprocal relationship between peer victimization and internalizing problems in children and adolescents: A meta-analysis of longitudinal studies

<p id="p00010">There is a close relationship between peer victimization and internalizing problems in children and adolescents. According to the interpersonal risk model, negative interpersonal experiences, such as peer victimization, are important stressors, and they leave children with their basic need for belonging unsatisfied and so lead to a series of problem behaviors. The symptom-driven model emphasizes that internalizing problems leaves individuals vulnerable to attack, so internalizing problems are risk factors for predicting peer victimization. The interaction model shows that childhood and adolescence are in high-incidence periods for peer victimization and internalizing problems, and internalizing problems may lead to negative peer reaction (such as peer victimization and peer rejection), which in turn induces more internalizing problems, and vice versa. <p id="p00015">Many studies have explored the longitudinal relationship between peer victimization and internalizing problems, but the results have been mixed. This meta-analysis was conducted to explore the strength and moderators of the longitudinal relationship between these two variables. Through literature retrieval, 99 independent effect sizes were selected, covering a total of 70, 598 participants, which met the inclusion criteria for meta-analysis. After coding the data, we analyzed the main effect and moderating effect using Comprehensive Meta-analysis Version 2.0. Heterogeneity testing indicated that the random effects model was suitable for the meta-analysis. Based on the funnel plot and Egger’s test of regression to the intercept, no significant publication bias was found in the included studies. <p id="p00020">The main effect test indicated significant prospective pathways from peer victimization to internalizing problems (<italic>β</italic> = 0.097, 95% CI = [0.083, 0.110]) and from internalizing problems to peer victimization (<italic>β</italic> = 0.119, 95% CI = [0.104, 0.135]), which suggests that peer victimization and internalizing problems are related in a reciprocal manner. Moderation analysis revealed that the predictive effect of peer victimization on internalizing problems was moderated by age and also by the type of peer victimization. The predictive effect of internalizing problems on peer victimization was moderated by measurement interval, type of peer victimization, method of assessment, and type of internalizing problems. However, whether the participants lived in Chinese or Western cultures did not moderate the relationships observed. <p id="p00025">The results supported the interaction model, which suggested that peer victimization and internalizing problems are mutually influencing factors. Future research and intervention program design should look for protective factors outside the individual system to help children and adolescents break the vicious circle between these two variables. Moreover, particular attention should be given to the effects of age, type of peer victimization, assessment method, measurement interval, and type of internalizing problems on the relationship between peer victimization and internalizing problems.

Pendulum-type tribometer for express evaluation of tribological characteristics of materials

A pendulum-type tribometer design is developed for express estimation of the moment and coefficient of friction in sliding friction pairs. The confidence interval of measurements is determined, a mathematical description of the principle of operation of the tribometer and formulas for calculating the coefficient and moment of friction are given. Keywords: tribometer, friction, Froude pendulum, friction coefficient, friction moment. palpuch@mail.ru, vitaliyivanov@yandex.ru

Physical properties of Quaternary sediments from the western South Korea Plateau, East Sea

Sediment samples were collected with a piston sampler (114 samples) and a box core sampler (266 samples) during research cruises on the R/V Tamhae 2 of the Korea Institute of Geoscience and Mineral Resources (KIGAM) from 2015 to 2019, to examine the characteristics of seafloor sediments from the western South Korea Plateau of East Sea. The in situ velocity was measured at four sites using a seafloor acoustic probe developed by KIGAM (KISAP). The samples were analyzed for their physical properties and the resulting data were examined to gain insights into the distribution patterns of the sediments and how the physical properties varied by burial depth. The actual velocity of the seafloor sediments was investigated by comparing the velocities in the laboratory and in situ velocity measurements at four sites. Overall, the physical properties agree well with the expected characteristics of marine sediments but there is considerable variation in the mean grain sizes. The sediment distributions either increases or decreases gradually with depth, reflecting transport from topographically high areas (e.g., possible source and/or shelf areas). The relationships between the physical properties of samples from two transects, one east-west and the other south-north, are different, and reflect the presence of tephra with a low grain density at the specified depth intervals. The laboratory velocity is higher (approximately 20–40 m/s) than the in situ velocity measured by the KISAP because of differences in the temperature (approximately 22 °C) and pressure (∼100 atmospheric pressure). However, the corrected laboratory velocity agrees well with the in situ velocity. Inconsistencies in the data, such as the measurement frequency and condition of each system, measurement interval, and sediment grain size, are probably responsible for some of the variations in the physical property data.

Comparative Study of Health Monitoring Sensors based on Prognostic Performance

In the safety critical systems such as industrial plants or aircraft, failure occurs inevitably during the operation, and it is important to prevent this while maintaining high availability. Therefore, a lot of efforts are being directed toward developing advanced prognostics algorithms and sensing techniques as an enabler for predictive maintenance. The key for reliable and accurate prediction not only relies on the prognostics algorithms but also based on the collection of sensor data. However, there is not much in-dept studies toward evaluating the varying sensing techniques based on the prediction performance and inspection scheduling. It would be more reasonable for practitioner to select different cost of sensors based on the sensors’ contribution on reducing the cost on unnecessary inspection or measurement while maintaining its prognosis performance. Thus, the authors try to thoroughly evaluate the cost-effectiveness of the different sensor with respect to sensor resistance to noise. The simulation is conducted to analyze the prediction performance with varying measurement interval and different level of noise during degradation. Then real run-to-fail (RTF) dataset acquired from two different sensors are analyzed to design optimal measurement system for predictive maintenance.