Metrologické aspekty v analytické chemii: stanovení kovů ve vodách

The monitoring of water quality in the EU is described in detail and regulated by Directives of the European Commission and the Parliament, which underlines the importance of the quality of water (both potable and non-potable). Analysis of trace concentrations of contaminants in water, including metals, still presents challenges to demonstrate the quality and comparability of results. The article provides a detailed overview of the procedures that laboratories can use to assess the reliability of the results obtained by a particular measurement procedure. Emphasis is placed on three basic pillars: metrological traceability, validation and measurement uncertainty. Subsequently continuous evaluation is carried out using internal and external quality management measures. Regional aspects specific for the Czech Republic are also mentioned.

Non-Debye Relaxations: The Ups and Downs of the Stretched Exponential vs. Mittag–Leffler’s Matchings

Experimental data collected to provide us with information on the course of dielectric relaxation phenomena are obtained according to two distinct schemes: one can measure either the time decay of depolarization current or use methods of the broadband dielectric spectroscopy. Both sets of data are usually fitted by time or frequency dependent functions which, in turn, may be analytically transformed among themselves using the Laplace transform. This leads to the question on comparability of results obtained using just mentioned experimental procedures. If we would like to do that in the time domain we have to go beyond widely accepted Kohlrausch–Williams–Watts approximation and become acquainted with description using the Mittag–Leffler functions. To convince the reader that the latter is not difficult to understand we propose to look at the problem from the point of view of objects which appear in the stochastic processes approach to relaxation. These are the characteristic exponents which are read out from the standard non-Debye frequency dependent patterns. Characteristic functions appear to be expressed in terms of elementary functions whose asymptotics is simple. This opens new possibility to compare behavior of functions used to describe non-Debye relaxations. It turnes out that the use of Mittag-Leffler function proves very convenient for such a comparison.

Quality of life study in ophthalmic practice

The article discusses various methods for studying the quality of life in all kinds of eye diseases. General and special questionnaires used in modern ophthalmological practice are presented. The presence of a sufficiently large amount of data indicating the relationship between the quality of life and objective indicators of the visual system was established. A fairly good comparability of results obtained in the assessment of various quality of life questionnaires in a patient with ophthalmic condition was revealed.

Using the vignette methodology to measure access

Background A vignette is a short description of a person or situation designed to simulate key features of a real- world scenario. Usually this vignette is then presented to relevant professionals to solicit their hypothetical response or behaviour. In medical literature, vignettes are mostly used to study clinical judgments, compare hospital prices, self-assess health or examine how age, sex, socioeconomic or insurance status affects chosen treatment. Methods We aimed to develop a method to utilize case vignettes to gain a better understanding of health access challenges. To this end, we studied available access indicators and frameworks and vignette applications as well as possible ways to include internationally recommended care plans to increase comparability of results across countries. Results We developed a five-step approach consisting of (1) selection of vignettes, (2) drafting of vignettes and a questionnaire based on available access framework and best practice guidelines for treatment, (3) expert validation, (4) application of vignette in country context, and (5) systematic analysis of country feedback. Four detailed pilots were carried out for dental care, stroke, depression and palliative care, in up to 12 European countries. Conclusions The vignette approach has the potential to identify gaps in coverage and access as well as differences in treatment and quality. Four detailed pilots have provided valuable insights in the challenges and limitations of the method that can be addressed in future applications. These include suggestions to improve user friendliness, scope, expert selection and complementing the survey with more specific and quantitative questions.

The Ordering of Gambling Severity and Harm Scales: A Cautionary Tale

Question-order effects are known to occur in surveys, particularly those that measure subjective experiences. The presence of context effects will impact the comparability of results if questions have not been presented in a consistent manner. In this study, we examined the influence of question order on how people responded to two gambling scales in the Australian Capital Territory Gambling Prevalence Survey: The Problem Gambling Severity Index and the Short Gambling Harm Screen. The application of these scales in gambling surveys is continuing to grow, the results being compared across time and between jurisdictions, countries, and populations. Here we outline a survey experiment that randomized the question ordering of these two scales. The results show that question-order effects are present for these scales, demonstrating that results from them may not be comparable across jurisdictions if the scales have not been presented consistently across surveys. These findings highlight the importance of testing for the presence of question-order effects, particularly for those scales that measure subjective experiences, and correcting for such effects where they exist by randomizing scale order.

One Metre Plus (1M+): A Multifunctional Open-Source Sensor for Bicycles Based on Raspberry Pi

During the last decade, bicycles equipped with sensors became an essential tool for research, particularly for studies analyzing the lateral passing distance between motorized vehicles and bicycles. The objective of this article is to describe a low-cost open-source sensor called one metre plus (1m+) capable of measuring lateral passing distance, registering the geographical position of the cyclist, and video-recording the trip. The plans, codes, and schematic design are open and therefore easily accessible for the scientific community. This study describes in detail the conceptualization process, the characteristics of the device, and the materials from which they are made. The study also provides an evaluation of the product and describes the sensor’s functionalities and its field of application. The objective of this project is to democratize research and develop a platform/participative project that offers tools to researchers worldwide, in order to standardize knowledge sharing and facilitate the comparability of results in various contexts.

A Recast Framework for Welfare Deservingness Perceptions

Many important societal debates revolve around questions of deservingness, especially when it comes to debates related to inequality and social protection. It is therefore unsurprising that a growing body of research spanning the social and political sciences is concerned with the determinants of deservingness perceptions. In this contribution, we engage with the currently central theoretical framework used in deservingness research and point out an important weakness: Partly ambiguous definitions of the framework’s central concepts, the criteria for perceived deservingness. We also highlight the negative consequences this has for empirical research, including notably varying and overlapping operationalizations and thereby a lacking comparability of results across studies. Our main contribution is a redefinition of the criteria for perceived deservingness and a demonstration of the empirical implications of using this new set of criteria via original vignette survey experiments conducted in Germany and the United States in 2019. Our results provide a clearer image of which criteria drive deservingness perceptions.

Harmonization status of procalcitonin measurements: what do comparison studies and EQA schemes tell us?

Sepsis represents a global health priority because of its high mortality and morbidity. The key to improving prognosis remains an early diagnosis to initiate appropriate antibiotic treatment. Procalcitonin (PCT) is a recognized biomarker for the early indication of bacterial infections and a valuable tool to guide and individualize antibiotic treatment. To meet the increasing demand for PCT testing, numerous PCT immunoassays have been developed and commercialized, but results have been questioned. Many comparison studies have been carried out to evaluate analytical performance and comparability of results provided by the different commercially available immunoassays for PCT, but results are conflicting. External Quality Assessment Schemes (EQAS) for PCT constitute another way to evaluate results comparability. However, when making this comparison, it must be taken into account that the variety of EQA materials consist of different matrices, the commutability of which has not yet been investigated. The present study gathers results from all published comparison studies and results from 137 EQAS surveys to describe the current state-of-the-art harmonization of PCT results. Comparison studies globally highlight a significant variability of measurement results that nonetheless seem to have a moderate impact on medical decision-making. For their part, EQAS for PCT provides highly discrepant estimates of the interlaboratory CV. Due to differences in commutability of the EQA materials, the results from different peer groups could not be compared. To improve the informative value of the EQA data, the existing limitations such as non-harmonized conditions and suboptimal and/or unknown commutability of the EQA materials have to be overcome. The study highlights the need for commutable reference materials that could be used to properly evaluate result comparability and possibly standardize calibration, if necessary. Such an initiative would further improve the safe use of PCT in clinical routine.

Human Milk Metabolic Profiling Using Biocrates MxP® Quant 500 Kit

Objectives Comprehensive metabolic profiling of human milk is a useful tool for examining its composition and relationship to maternal and infant metabolism and status. Methods A pooled milk sample was used to evaluate the Biocrates MxP® Quant 500 kit for human milk metabolomics (107 small molecules and 523 lipids) using an ABSciex 5500QTRAP mass-spectrometer in LC-MS/MS and flow injection analysis (FIA) mode. Additionally, milk from Brazilian mothers (A: 2–8, B: 28–50, C: 88–119d postpartum, ntotal = 25) was analyzed. Results 424 of the 630 assay metabolites were detected in the milkpool above the limit of quantitation (LOQ); 31 metabolites were below the lower limit of quantitation (LLOQ), while 7 were above the upper limit (ULOQ), mostly free fatty acids including arachidonic acid, docohexaenoic acid, and eicosapentaenoic acid. Bile acids were only detected below LLOQ. Concentrations measured in 5 different sample volumes (2–20μL, n = 10) showed satisfactory reproducibility (CV 3.7–20.0%) for 458 metabolites. Acceptable intraday variation (80–120%, 6 replicates) was achieved for 409 metabolites when spiking with 3 levels of QC-standards, but only for 127 metabolites after dilution (1:2 and 1:5). However, 396 metabolites revealed a good intraday variation when only considering the 1:2-dilution. Conclusions The MxP Quant® 500 kit was successfully employed for human milk providing data for over 400 metabolites in 10μL milk. and thus offers ability to use the same assay for both human plasma and milk, enhancing comparability of results by reducing analytical bias and increasing our ability to study milk as a biological system. Funding Sources Bill & Melinda Gates Foundation (OPP1148405), USDA/ARS Intramural Project (5306–51,530-019–00), and CNPq (Brazilian National Council for Science and Technology).

PROVISION OF CONDITIONS OF COMPARABILITY OF RESULTS IN FIELD BIOTECHNOLOGICAL RESEARCH USING A COMPUTER EXPERIMENT

When conducting biotechnological field studies using plant objects, there is a problem of taking into account the heterogeneity of the results, the imperfection of methods leads to the need for multiple repetitions of experiments, but the issue of reproducibility and comparability of research results is not resolved, therefore, the use of mathematical models in research makes it possible not only to identify, but also to explain the obtained patterns. The subject of the study in the article is a simulation model for estimating the mass of corn grains taking into account their genotype and growing conditions. The model is based on an analytical expression that reflects the main reasons for the growth of corn seeds after pollination of the plant. The mass of corn grains depends on a number of biological factors (genotype), technological – soil structure (its fertility and methods of cultivation), and climatic conditions (humidity, light intensity). The aim of the study is to create a simulation model to ensure the comparability of the results obtained when growing corn for grain in different conditions. Biological (cultivation) and mathematical (simulation model) methods were used as methods for obtaining and constructing results. The discrepancy in the estimation of the mass of grain of the same genotype grown in different research farms of different climatic zones of Ukraine and obtained by calculation was not more than 18 % and obtained experimentally up to 64 %. A feature of the model is the independence of the heterogeneity of the bioobject (studied lines and hybrids) from the conditions of their cultivation (soil structure and climatic conditions). The application of mathematical modeling makes it possible to reduce the differences in the studied indicators up to 25 times, which were obtained in different experiments, thereby significantly reducing time, money and provide a condition for comparability of results to obtain a reliable result.