Radboud University Nijmegen

About: Radboud University Nijmegen is a education organization based out in Nijmegen, Gelderland, Netherlands. It is known for research contribution in the topics: Population & Context (language use). The organization has 35417 authors who have published 83035 publications receiving 3285064 citations. The organization is also known as: Catholic University of Nijmegen & Radboud University.

2015 Gout Classification Criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative.

Abstract: Objective Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout. Methods An international group of investigators, supported by the American College of Rheumatology and the European League Against Rheumatism, conducted a systematic review of the literature on advanced imaging of gout, a diagnostic study in which the presence of monosodium urate monohydrate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multicriterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent data set. Results The entry criterion for the new classification criteria requires the occurrence of at least 1 episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (i.e., synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time course of symptomatic episodes), laboratory (serum urate, MSU-negative synovial fluid aspirate), and imaging (double-contour sign on ultrasound or urate on dual-energy computed tomography, radiographic gout-related erosion). The sensitivity and specificity of the criteria are high (92% and 89%, respectively). Conclusion The new classification criteria, developed using a data-driven and decision analytic approach, have excellent performance characteristics and incorporate current state-of-the-art evidence regarding gout.

Population genetics, molecular markers and the study of dispersal in plants

Abstract: Summary 1 Long-distance dispersal events are biologically very important for plants because they affect colonization probabilities, the probabilities of population persistence in a fragmented habitat, and metapopulation structure. They are, however, very difficult to investigate because of their low frequency. We reviewed the use of molecular markers in the population genetics approach to studying dispersal. With these methods the consequences of long-distance dispersal are studied, rather than the frequency of the dispersal events themselves. 2 Molecular markers vary, displaying different amounts of variation and different modes of inheritance: they may be either dominant or codominant, and may or may not be subjected to genetic recombination. Use of markers has inspired the development of maximum likelihood techniques that take the evolutionary history of alleles into account while estimating gene flow. 3 Inferring seed dispersal rates from indirect measurements of gene flow involves three steps: (i) quantifying genetic differentiation among populations and using this to estimate the rate of gene flow; (ii) producing a genetic dispersal curve by regressing geographical distance among populations against the amount of gene flow; and (iii) separating seed-mediated from pollen-mediated gene flow, by comparing differentiation in nuclear vs. cytoplasmic molecular markers. In this way, potentially very low levels of gene flow can be detected. 4 The indirect approach is based on a number of assumptions. The validity of each assumption should be assessed by independent methods or the estimates of gene flow and dispersal should be mainly used in a comparative context. In metapopulations, with frequent extinction and colonization, the relationship between genetic differentiation and gene flow is not straightforward, and other methods should be used. 5 Highly variable molecular markers, especially microsatellites, have facilitated a direct genetic approach to measuring gene flow, based on parental analyses. 6 The population genetic approach provides different information about dispersal than ecological methods. Thus population genetic and ecological methods may supplement each other, and together lead to a better insight into the dispersal process than either of the methods on its own.

Distinct neural signatures detected for ADHD subtypes after controlling for micro-movements in resting state functional connectivity MRI data.

Abstract: In recent years, there has been growing enthusiasm that functional magnetic resonance imaging (MRI) could achieve clinical utility for a broad range of neuropsychiatric disorders. However, several barriers remain. For example, the acquisition of large-scale datasets capable of clarifying the marked heterogeneity that exists in psychiatric illnesses will need to be realized. In addition, there continues to be a need for the development of image processing and analysis methods capable of separating signal from artifact. As a prototypical hyperkinetic disorder, and movement-related artifact being a significant confound in functional imaging studies, ADHD offers a unique challenge. As part of the ADHD-200 Global Competition and this special edition of Frontiers, the ADHD-200 Consortium demonstrates the utility of an aggregate dataset pooled across five institutions in addressing these challenges. The work aimed to (1) examine the impact of emerging techniques for controlling for "micro-movements," and (2) provide novel insights into the neural correlates of ADHD subtypes. Using support vector machine (SVM)-based multivariate pattern analysis (MVPA) we show that functional connectivity patterns in individuals are capable of differentiating the two most prominent ADHD subtypes. The application of graph-theory revealed that the Combined (ADHD-C) and Inattentive (ADHD-I) subtypes demonstrated some overlapping (particularly sensorimotor systems), but unique patterns of atypical connectivity. For ADHD-C, atypical connectivity was prominent in midline default network components, as well as insular cortex; in contrast, the ADHD-I group exhibited atypical patterns within the dlPFC regions and cerebellum. Systematic motion-related artifact was noted, and highlighted the need for stringent motion correction. Findings reported were robust to the specific motion correction strategy employed. These data suggest that resting-state functional connectivity MRI (rs-fcMRI) data can be used to characterize individual patients with ADHD and to identify neural distinctions underlying the clinical heterogeneity of ADHD.

Language proficiency and reading ability in first- and second-language learners

Abstract: The purpose of the present study was to investigate the development of and interrelations between the language proficiencies and reading abilities of children learning to read in either a first language or a second language. The authors compared the reading-comprehension, word-decoding, and oral-language skills of both high and low SES Dutch third and fourth graders to the skills of low SES minority third and fourth graders from a Turkish or Moroccan background living in the Netherlands. Several tests of reading comprehension, word decoding, oral text comprehension, morphosyntactic knowledge, and vocabulary knowledge were administered at the beginning of third grade, the end of third grade, and the end of fourth grade. The results showed the minority children to be faster decoders than the Dutch low SES children. With respect to reading comprehension and oral language proficiency, however, the minority children were found to lag behind the Dutch children in all respects. With respect to the interrelations between oral-language skills and reading skills, the development of reading comprehension was found to be influenced more by top-down comprehension-based processes than by bottom-up word-decoding processes for both the first- and second-language learners. The oral Dutch skills of the minority children played a more prominent role in the explanation of their reading-comprehension skills than the oral-language skills of the Dutch children, however.