Introduction to Statistical Methods for Outlier Detection and Sample Homogeneity Assessment of Reference Materials and Proficiency Test Items

Due to the homogeneity of the product or sample, it will affect whether it meets the scope of application and purpose. For example, the reference materials(RM) produced by the reference material producer(RMP), and the proficiency test items selected by the proficiency testing provider(PTP), in order to ensure the reference materials or proficiency test items have consistent characteristics or comparability, they should be proved to have certain homogeneity. However, before performing homogeneity assessment, it is necessary to measure the characteristic parameters of the reference materials or proficiency test items to obtain a sufficient number of measured values for data analysis, but there may be outliers in the measured values that may affect data analysis and interpretation of the results. Therefore, this article will refer to ASTM E178-16a:2016[1], ISO 5725-2:1994[2], ISO 13528:2015[3], etc., to introduce several outlier detection and homogeneity assessment methods, supplemented by case studies. Finally, this article will remind the precautions for the use of the method, so that readers can choose the appropriate method for use in the actual analysis.

The role and the effects of the ozone paravertebral injections, in lumbar disc herniation patients.

The results obtained from a group of patients suffering from discoradicular conflict syndrome treated with paravertebral oxygen-ozone injections were analyzed. From a total number of 8500 patients treated with ozone during the period 2002/2015, 880 patients underwent intradiscal injection and 7620 patients were treated with paravertebral ozone injections. This paper analyses a subgroup of 1850 patients (24.28% of the patients who were treated with paravertebral injections), including those patients who underwent the total 10-session treatment, complied with a 5-year follow-up and with the sample homogeneity parameters following a predictability therapeutic effectiveness (PET) index devised for such purpose (PET index O3) by us in 2009. The outcomes were assessed based on the VAS score and modified Mac Nab criteria. Definite results determined positive post-treatment outcomes considered excellent and good in 81% of the cases. Such effectiveness percentage resulted lower than the one achieved with the intradiscal injection technique (89%), and higher than the percentage seen in papers on the selective nerve root block technique.

Synchronizing Students Learning Styles in Promoting Learners’ Grammatical Knowledge; a Cultural Dimensions Study

This study aims to examine learning styles based on cultural dimensions theory’s hypothesis. The research focuses to investigate whether styles from cultural view provide an exact description of students’ learning styles and to describe the exactitude of current concept of the theory’s hypothesis. The study employs quasi-experimental design which clusters the experimental design into control and experimental group. In collecting the data, cultural dimensions questionnaire was used to determine students learning styles. As instructed by cultural dimensions theory, one group was assigned with students-centered learning and one was with teacher centered learning. One Way Anove test was conducted to determine the sample homogeneity. The statistical analysis uses Wilcoxon Statistic Test to compare the results of control group and experimental group. The result of experimental group shows moderate learning outcome significance compared to control group. The result is not necessarily significant but consistent. The study suggests that empowering students learning styles will help students learn better compared to conventional teaching.

Improving Outcomes for English Learners Through Technology: A Randomized Controlled Trial

English learners (ELs) in K–12 schools must acquire English while simultaneously mastering content knowledge. Educational technology may support students’ learning through the affordance of individualized language practice. The current randomized controlled trial intervention study examined the effects of Rosetta Stone Foundations software on English learning among middle school ELs. The study took place in Grades 6 to 8 of an urban U.S. school district ( N = 221). Predictors of interest included time of testing (pretest vs. posttest) and software usage, and covariates included grade level, sex, and attendance. Additionally, socioeconomic status and home language were accounted for due to sample homogeneity. Multilevel models indicated that treatment group students showed larger gains than control group students on oral/aural outcomes. These results indicate that the software intervention enables individualized practice that can produce proficiency-related gains over and above the typical classroom curriculum.

Methods of application of Wilcoxone and Manna-Whitney criteria in pedagogical experiment

In [1], we considered the problems of identifying and calculating the criteria for testing the hypothesis of homogeneity of two independent samples. In particular, we drew attention to the ambiguous names of the hypothesis test criterion. We also noted the difference between the assumptions and formulations of the hypothesis. In this case, different formulas for calculations require proof of their equivalence. Our analysis of research and publications has shown that examples of the application of the criteria of homogeneity of Wilcoxon and Mann-Whitney samples are largely technical in nature. That is, these examples usually contain tools for calculating statistics and do not cover all the possibilities of applying the criteria. Therefore, the method of using criteria requires an optimal combination of theoretical principles with the formation of practical skills of hypothesis testing. When conducting a pedagogical experiment, the researcher should be able to consider theoretically sound calculation examples. These examples of the application of criteria should be available primarily to researchers who are not mathematicians. Our experience has confirmed the need for the researcher to acquire stable skills in the practical application of the criteria of sample homogeneity in scientific and pedagogical research. We considered the concept of sample homogeneity in conducting a pedagogical experiment on the examples of statistical information of control and experimental groups. It was noted that the homogeneity of the samples can not always be determined by direct observation of their elements. We formulated an algorithm for applying the Wilcoxon and Mann-Whitney criteria to test the hypothesis �0: F1(x) = F2(x) about the homogeneity of the samples. We have considered examples of the application of criteria in a pedagogical experiment. In particular, the statistical values of the Wilcoxon test and the Mann-Whitney criteria were calculated. Also, we show their connection with the area of acceptance of hypothesis �0 under different alternative hypotheses �1. The prospect of our further research is the formation of methods for applying the criteria most commonly used in scientific and pedagogical research of distributions of random variables. Key words: Wilcoxon criteria, Mann-Whitney criteria, sample homogeneity, hypothesis acceptance area, sample rank.

Long- and Short-Ranged Chiral Interactions in DNA Assembled Plasmonic Chains

Molecular chirality plays a crucial role in innumerable biological processes. The chirality of a molecule can typically be identified by its characteristic optical response, the circular dichroism (CD). CD signals have thus long been used to identify the state of molecules or to follow dynamic protein configurations. In recent years, the focus has moved towards plasmonic nanostructures, as they show potential for applications ranging from pathogen sensing to novel optical materials. The plasmonic coupling of the individual elements of such chiral metallic structures is a crucial prerequisite to obtain sizeable CD signals. We here identified and implemented various coupling entities - chiral and achiral - to obtain chiral transfer over distances close to 100 nm. The coupling is realized by an achiral nanosphere situated between a pair of gold nanorods that are arranged far apart but in a chiral fashion. We synthesized these structures with nanometer precision using DNA origami and obtained sample homogeneity that allowed us to directly demonstrate efficient chiral energy transfer between the distant nanorods. The transmitter particle causes a strong enhancement in amplitude of the CD response, the emergence of an additional chiral feature at the resonance frequency of the nanosphere, and a redshift of the longitudinal plasmonic resonance frequency of the nanorods. Numerical simulations closely match our experimental observations and give insights in the intricate behavior of chiral optical fields and the transfer of plasmons in complex architectures.

Development and Validation of a Highly Generalizable Deep Learning Pulmonary Embolism Detection Algorithm

Several algorithms have been developed for the detection of pulmonary embolism, though generalizability and bias remain potential weaknesses due to small sample size and sample homogeneity. We developed and validated a highly generalizable deep-learning algorithm, Emboleye, for the detection of PE by using a large and diverse dataset, which included 30,574 computed tomography (CT) exams sourced from over 2,000 hospital sites. On angiography exams, Emboleye demonstrates an AUROC of 0.79 with a specificity of 0.99 while maintaining a sensitivity of 0.37 and PPV of 0.77. On non-angiography CT exams, Emboleye demonstrates an AUROC of 0.77 with a specificity of 0.99 while maintaining a sensitivity of 0.18 and PPV of 0.35.

A Novel Procedure of Total Organic Carbon Analysis for Water Samples Containing Suspended Solids with Alkaline Extraction and Homogeneity Evaluation by Turbidity

This study was conducted to develop and validate a more reliable total organic carbon (TOC) analytical procedure for water samples containing suspended solids (SS). The effects of the combined ultrasonic and alkaline pretreatment (CULA) on the TOC measurement were studied in water samples containing SS from three origins (algae, sewage particles, and soil) under different analytical conditions (SS concentration, oxidation methods, and sieve size). The applicability of turbidity as a homogeneity index was also evaluated. With CULA, TOC recovery remained high (>80%) for SS concentration ranges up to four times larger than ultrasonic pretreatment alone (UL) due to enhanced particulate organic carbon (POC) solubilization, and did not significantly differ depending on the oxidation methods, at low SS concentrations, or with varying sieve sizes. In particular, the turbidity change rate (i.e., NTU5/NTU0) of the pretreated water sample showed a high correlation with TOC precision (r2 = 0.73, p < 0.01), which suggests that turbidity can be used as an indicator of sample homogeneity. A novel TOC analytical procedure is expected to be useful for more accurate assessments of the impact of particulate pollutants on water quality than current methods, and for the analysis of the carbon cycle, including POCs, in the environment.