Use of biochemical parameters for non-invasive screening of oesophageal varices in comparison to elastography-based approach in patients with compensated advanced chronic liver disease

IntroductionOesophageal varices are routinely diagnosed by esophagogastroduodenoscopy (EGD), and their bleeding has high mortality. We aimed to evaluate diagnostic performance of biochemical tests in comparison to elastography-based approaches, as non-invasive alternatives to EGD, for ruling-out high risk oesophageal varices (HRV).Material and methodsRetrospective analysis of patients (N = 861) who underwent liver stiffness measurement (LSM) by transient elastography (TE) in a single centre over 5-year period, with available results of EGD (within 3 months from LSM). Only patients with suspicion of compensated advanced chronic liver disease (cACLD) defined by LSM ≥ 10 kPa were included comprising the final cohort of 73 subjects. Original and expanded Baveno VI criteria (B6C), controlled attenuation parameter (CAP), platelet count (PLT), aspartate aminotransferase to PLT ratio index (APRI), Fibrosis-4 index (FIB4), model for end stage liver disease (MELD) score were evaluated against the results of EGD that served as the reference method.ResultsAnalysed patients had median age 62 years, 59/73 (0.81) were males, 54/73 (0.74) had alcoholic/non-alcoholic fatty liver disease, and 21/73 (0.29) had HRV. In multivariate logistic regression analysis only LSM and PLT were independently associated with HRV. The best performing tests for ruling-out HRV (% of spared EGD; % of missed HRV) were respectively: LSM < 20 kPa (53.4%; 0%), B6C (38%; 0%), Expanded B6C (47.9%; 4.8%); PLT > 214x10⁹/L (21.9%; 0%); FIB4 ≤ 1.8 (21.4%; 0%), APRI ≤ 0.34 (12.3%; 0%). CAP, MELD = 6 alone or combined with PLT > 150(x10⁹/L) did not show acceptable performance.ConclusionThe best performing biochemical tests for ruling-out HRV in our cohort of patients were PLT and FIB-4, but they were still outperformed by elastography-based approaches.Keyword: portal hypertension, cirrhosis, platelet count, esophageal varices, non-invasive tests     

Analysis of censored data

Analyzing events over time is often complicated by incomplete, or censored, observations. Special non-parametric statistical methods were developed to overcome difficulties in summarizing and comparing censored data. Life-table (actuarial) method and Kaplan-Meier method are described with an explanation of survival curves. For the didactic purpose authors prepared a workbook based on most widely used Kaplan-Meier method. It should help the reader understand how Kaplan-Meier method is conceptualized and how it can be used to obtain statistics and survival curves needed to completely describe a sample of patients. Log-rank test and hazard ratio are also discussed.     

Geschlechtsspezifische Leistungsunterschiede in Abhängigkeit der sozialen Herkunft. Eine Untersuchung zur Interaktion zweier sozialer Kategorien

Gender differences in educational outcomes are often reported. However, some evidence suggests that these differences are not consistent but vary with social background. In quantitative research, however, the interaction between gender and social background has been underinvestigated. The present study investigates whether the effect of gender on achievement is moderated by socio-economic status (SES). The sample consists of N = 3935 primary school-children in Berlin (6th grade). The results show that the effect of gender on achievement varies with SES, with a stronger correlation between the achievement of boys and their SES. Taken together, the results of the study suggest a differentiated consideration of the achievement of boys and girls and the importance of considering multiple group identities.     

Chameleon effects in homework research: The homework–achievement association depends on the measures used and the level of analysis chosen

Using a data set specifically tailored to homework research, with a sample of 1275 students from 70 classes in Switzerland, the association between homework and achievement in French as a second language was tested at three levels (class level, between-student level, and within-student level). The strength and direction of the homework–achievement association depended on the homework indicator chosen and differed to some degree across analytical levels. At the class level, achievement was higher in classes set frequent homework assignments and in classes where students reported low overall levels of negative emotions when doing homework. At the between-student level, high individual homework effort and low levels of negative homework emotions predicted favorable developments in French achievement, whereas high homework time predicted lower achievement. At the intraindividual level, high homework effort, high homework time, and low levels of negative homework emotions were statistically significantly associated with positive student evaluations of the learning gains from the specific assignment.     

Approximation based on orthogonal and almost orthogonal functions

In this paper, we define a class of almost orthogonal rational functions of Legendre type in a new manner. Relations of these functions with classical exponentional functions orthogonal over interval (0, ∞), as well as classical polynomials orthogonal over (0, 1) are explained. Defining relations of these functions can be used for designing almost orthogonal filters. These filters are generators of orthogonal signals and can be successfully applied in finding the best signal approximation in the sense of the mean square error. The filters orthogonal property enables building of physical (in this case electrical) models of dynamical systems (the sources of signals to be approximated) either with less components for the same model accuracy or higher accuracy for the same number of components than the other known models. New filters represent further improvement of previously designed filters, by the same authors, in the sense of simplicity, higher accuracy, lesser approximation time and even a possibility to approximate signals generated by systems with built-in imperfections. Series of experiments were performed to analyze the dependence of approximation accuracy and the number of filters sections.     

Hearing Where the Eyes See: Children Use an Irrelevant Visual Cue When Localizing Sounds

To reduce sensory uncertainty, humans combine cues from multiple senses. However, in everyday life, many co‐occurring cues are irrelevant to the task at hand. How do humans know which cues to ignore? And does this ability change with development? This study shows the ability to ignore cross‐modal irrelevant information develops late in childhood. Participants performed a sound discrimination task, with or without an irrelevant visual flash, presented synchronously in front of them. Adults ignored the irrelevant visual information, while 7‐ to 10‐year‐olds' responses were biased toward the flash location. The findings show that acquiring mature cue combination mechanisms is a multifaceted process that includes learning to ignore irrelevant cues, as well as to optimally combine relevant cues.     

Soziale Ungleichheiten beim Übergang von der Grundschule in die Sekundarstufe I: Theorie,Forschungsstand, Interventions- und Fördermöglichkeiten

Based on a theoretical model, which distinguishes between primary and secondary effects following Boudon, the present paper summarizes empirical evidence regarding the impact of family background on the transition from elementary into secondary school. In doing so, three types of secondary effects are distinguished: secondary effects of school grades, teacher recommendations, and the transition itself. The empirical literature suggests that both primary and secondary effects exist in the German school system: In addition to having lower achievement, children from disadvantaged backgrounds receive lower grades and fewer recommendations for higher tracks and are less likely to attend a high track even when controlling for their achievement. The paper closes by presenting findings from studies analyzing the relative importance of primary and secondary effects and a discussion on how effects of family background on the transition into secondary school can be reduced.     

Soziale Ungleichheiten in der Kompetenzentwicklung in der Grundschule und der Sekundarstufe I

The article focuses on the question how competencies of students with different social backgrounds develop during elementary and secondary school. In particular, it addresses if achievement disparities which exist before school entrance increase, remain stable, or even diminish during schooling. The article draws on both national and international studies with longitudinal designs examining the achievement development of students of different social backgrounds during primary or secondary school. Although the results are mixed to some extent, a large part indicates that differences in achievement increase during the time of schooling. The evidence seems more consistent for achievement development during elementary school. Additionally, there is some indication that schools and features of the educational system contribute to increasing achievement disparities between students of different social backgrounds.     

Promotion of students’ mastery goal orientations: does TARGET work?

Achievement goal orientations are important for students’ ongoing motivation. Students with a mastery goal orientation show the most advantageous achievement and motivational patterns. Much research has been conducted to identify classroom structures which promote students’ mastery goal orientation. The TARGET framework is one example of these efforts and provides six instructional dimensions (task, authority, recognition, grouping, evaluation, time), which should form a classroom structure that fosters a mastery goal orientation. The aim of this study was to examine the entire multi-dimensional TARGET framework and its impact on mastery goal orientation in a longitudinal study with 1680 secondary school students. CFAs confirmed the existence of one latent factor TARGET comprising the six proposed dimensions. This study also provides the first empirical evidence, based on longitudinal data, that TARGET has a positive impact on student mastery goal orientations.     

Facebook Versus Moodle in Practice

Very few research papers and case studies have shown successful integration of both Facebook and Moodle in the educational experience of students. This study sought to evaluate the educational benefits of the increasingly popular Facebook—which plays an important role in students’ social life as well as their academic life—and to compare it with the widely used course management system Moodle. In this study, the authors surveyed students of the University of Belgrade’s Faculty of Organizational Science in Serbia on their attitude toward Facebook and Moodle as productive online tools for teaching and learning. An analysis of the results was carried out using the SPSS software package. The results of this research answer the question of whether or not using Facebook as an educational tool is more effective than using Moodle and how it affects students’ everyday learning activities.