Reliability assessment and correlation analysis of 3 protocols to measure trunk muscle strength and endurance

Different methods have been developed to quantify trunk muscle strength and endurance. However, some important protocol characteristics are still unclear, hindering the selection of the most suitable tests in each specific situation. The aim of this study was to examine the reliability and the relationship between 3 representative tests of the most common type of protocols used to assess trunk muscle strength and endurance. Twenty-seven healthy men performed each test twice spaced 1 month apart.Trunk strength and endurance were evaluated with an isokinetic dynamometer and 2 field tests including Biering-Sørensen test and Flexion–rotation trunk test.

All tests showed a good relative consistency (intraclass correlation coefficient [ICC]> 0.75), except for the isokinetic endurance variables which had low–moderate reliability (0.37 < ICC > 0.65). Absolute reliability seemed slightly better in the isokinetic protocol than in the field tests, which showed about 12% of test–retest score increase. No significant correlations were found between test scores.

After a familiarisation period for the field tests, the 3 protocols can be used to obtain reliable measures of trunk muscle strength and endurance. Based on the correlation analysis, these measures are not related, which highlights the importance of selecting the most suitable trunk test for each situation.     

Definitional Elasticity in the Measurement of Intergenerational Continuity in Substance Use

Increasingly, three generation studies have investigated intergenerational (IG) continuity and discontinuity in substance use and related problem behaviors. However, surprisingly little attention has been paid to the conceptual definition of continuity or to different types of discontinuity (resilience and escalation) or to measurement sensitivity, which affects not only the magnitudes of observed continuity but also factors that correlate with this linkage. This study uses longitudinal data on 427 parent–child dyads from the Rochester IG Study to study continuity and discontinuity in substance use over ages 14–18. Results suggest that the degree of IG continuity, resilience, and escalation in adolescent substance use, as well as correlates of each, depend heavily on how heterogeneity in the behavior is taken into account.     

Academic self‐attributions for success and failure in mathematics and school refusal

The aim of this research is twofold: to analyze the mean differences scores in mathematic self‐attributions based on school refusal and to verify its predictive capability on high scores in school refusal. The Sydney Attribution Scale and the School Refusal Assessment Scale‐Revised were administered to 1078 Spanish students (50.8% boys) aged between 8 and 11 years (M = 9.63; SD = 1.12). School refusers based on negative affect or anxiety attributed their failures more to the lack of capacity and effort, whereas students searching for tangible reinforcements outside of the school were more likely to attribute their successes to capacity. In turn, academic attributions acted as both positive and negative predictors of high‐school refusal. Results are discussed considering more adaptive attributional styles.     

The Progression of Prospective Primary Teachers’ Conceptions of the Methodology of Teaching

This article describes the evolution of prospective primary teachers’ conceptions of the methodology of teaching. Three categories were analyzed: the concept of activity, the organization of activities, and the concept of teaching resources. The study was conducted with five teams of prospective teachers, who were participating in teacher education courses of a constructivist orientation. The results showed very different itineraries in the processes of change, and the presence of two major obstacles—the belief that teaching is the direct cause of learning, and epistemological absolutism. The study allows us to deduce some implications for initial teacher education.     

Choosing among alternative technological strategies: an empirical analysis of formal sources of innovation

This work aims to offer a detailed conceptual and empirical analysis of the inter-firm differences in deciding the composition of their technological efforts. Using data for Spanish firms in the period 1990-1996, the study begins with the standard analysis of the determinants of innovative investment, then moves on to the less analysed question of the determinants of the generate versus import alternative and ends with a novel analysis of the characteristics which lead firms to organise research internally as compared to the possibility of contracting R&D services externally. In contrast to standard practice, the econometric approach takes into account the existence of non-linearities in the used data. The results obtained support the conceptual ideas on which they are based.     

A constructivist approach to studying the bullwhip effect by simulating the supply chain

The Cider Game is a simulator for a supply chain-related learning environment. Its main feature is that it provides support to students in the constructivist discovery process when learning how to make logistics decisions, at the same time as noting the occurrence of the bullwhip phenomenon. This learning environment seeks a balance between direct instruction in the learning process on the part of the tutor, and a suitable and sufficient degree of freedom to regulate independent learning on the part of students. This article describes the basic learning mechanisms using the Cider Game and the graphical learning environments that it provides. We describe the functionality provided by this application, and analyse the effect over the rational understanding of the bullwhip phenomenon by the students and whether they are able to make decisions to minimise its impact, studying the differences when that decision-making learning is done individually or in groups.     

Microfluidic system for near-patient extraction and detection of miR-122 microRNA biomarker for drug-induced liver injury diagnostics

Drug-induced liver injury (DILI) results in over 100 000 hospital attendances per year in the UK alone and is a leading cause for the post-marketing withdrawal of new drugs, leading to significant financial losses. MicroRNA-122 (miR-122) has been proposed as a sensitive DILI marker although no commercial applications are available yet. Extracellular blood microRNAs (miRNAs) are promising clinical biomarkers but their measurement at point of care remains time-consuming, technically challenging, and expensive. For circulating miRNA to have an impact on healthcare, a key challenge to overcome is the development of rapid and reliable low-cost sample preparation. There is an acknowledged issue with miRNA stability in the presence of hemolysis and platelet activation, and no solution has been demonstrated for fast and robust extraction at the site of blood draw. Here, we report a novel microfluidic platform for the extraction of circulating miR-122 from blood enabled by a vertical approach and gravity-based bubble mixing. The performance of this disposable cartridge was verified by standard quantitative polymerase chain reaction analysis on extracted miR-122. The cartridge performed equivalently or better than standard bench extraction kits. The extraction cartridge was combined with electrochemical impedance spectroscopy to detect miR-122 as an initial proof-of-concept toward an application in point-of-care detection. This platform enables the standardization of sample preparation and the detection of miRNAs at the point of blood draw and in resource limited settings and could aid the introduction of miRNA-based assays into routine clinical practice.