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Frank Preusser, Jan-Hendrik May, David Eschbach, Mareike Trauerstein and Laurent Schmitt

Abstract

Knowledge of the age of fluvial deposits is an important aspect in the understanding of river dynamics, which is pre-requisite for sustainable river management and restoration back to more natural conditions and processes. Presented here is a case study on using feldspar Infrared Stimulated Luminescence (IRSL) to date low-energy fluvial sediments that formed after correction of the Upper Rhine River in the first half of the 19th century. A rigorous testing programme is carried out to characterise the IRSL properties of the samples, including thermal transfer, dose recovery and fading. All samples reveal complex distributions of equivalent dose, implying the presence of differential bleach-ing in the samples. It is shown that multi-grain aliquots overestimate the known-age by up-to 200 years, i.e. apparent IRSL ages are twice as old as the true age of the sediment. The use of single grains results in ages that are in excellent agreement with the expected age, therefore the age overestimation in multi-grain aliquot measurements is likely explained by signal averaging effects. While the application of single grains appears mandatory for dating young low-energy fluvial deposits, the small absolute offset associated with the multi-grain approach might be acceptable when dating sediments of such type that are older than a few 1000 years.

Open access

Septimiu Daniel Popescu, Alex Otniel Popescu, Mihaela Dănilă, Mihaela Dobria, David Maior and Valentin Nădăşan

Abstract

Background: The quality of online health-related information may affect users’ understanding and medical decision-making with dramatic impact, particularly in case of stroke. Objective: The objective of this study was to assess the quality of information about stroke on the Romanian and Hungarian websites in terms of completeness and accuracy. Methods: The research was designed as an observational cross-sectional study. The sample included 25 Romanian and 25 Hungarian websites presenting information about stroke for the general public. General characteristics such as website ownership, main goal, website genre and medical approach were identified by the evaluators using a predetermined set of common instructions. The completeness and accuracy of the information were assessed by two independent assessors against a quality benchmark. Results: Overall, most of the websites were owned by private commercial companies (42%), had educational goal (66%), were designed as medical web-portals (46%) and had a conventional medicine approach (72%). Mean completeness score was 5.6 points (SD± 1.9) for Romanian sites and 4.1 points (SD ± 2.4) for Hungarian sites (p = 0.017). Mean accuracy score was 6.2 points (SD ± 1.1) for Romanian sites and 7.0 points (SD ± 0.7) for Hungarian sites (p = 0.02). Conclusions: The information about stroke on the Romanian and Hungarian websites had poor quality. Although we found statistically significant differences between the quality scores of the two language sub-samples and two site characteristics associated with significantly higher quality, the practical relevance of these findings for online health information seekers should be interpreted with caution.