Hyperparameter Importance Across Datasets

With the advent of automated machine learning, automated hyperparameter optimization methods are by now routinely used in data mining. However, this progress is not yet matched by equal progress on automatic analyses that yield information beyond performance-optimizing hyperparameter settings. In this work, we aim to answer the following two questions: Given an algorithm, what are generally its most important hyperparameters, and what are typically good values for these? We present methodology and a framework to answer these questions based on meta-learning across many datasets. We apply this methodology using the experimental meta-data available on OpenML to determine the most important hyperparameters of support vector machines, random forests and Adaboost, and to infer priors for all their hyperparameters. The results, obtained fully automatically, provide a quantitative basis to focus efforts in both manual algorithm design and in automated hyperparameter optimization. The conducted experiments confirm that the hyperparameters selected by the proposed method are indeed the most important ones and that the obtained priors also lead to statistically significant improvements in hyperparameter optimization.Comment: \c{opyright} 2018. Copyright is held by the owner/author(s). Publication rights licensed to ACM. This is the author's version of the work. It is posted here for your personal use, not for redistribution. The definitive Version of Record was published in Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery & Data Minin

Topography-Mediated Fibroblast Cell Migration Is Influenced by Direction, Wavelength, and Amplitude

Biophysical stimuli including topography play a crucial role in the regulation of cell morphology, adhesion, migration, and cytoskeleton organization and have been known to be important in biomaterials design for tissue engineering. However, little is known about the individual effects of topographic direction, structure repetition, and feature size of the substrate on which wound healing occurs. We report on the design of a topographical gradient with wavelike features that gradually change in wavelength and amplitude, which provides an efficient platform for an in vitro wound healing assay to investigate fibroblast migration. The wound coverage rate was measured on selected areas with wavelength sizes of 2, 5, and 8 mu m in perpendicular and parallel orientations. Furthermore, a method was developed to produce independently controlled wavelength and amplitude and study which parameter has greater influence. Cell movement was guided by topographical properties, with a lower wrinkle wavelength (2 mu m) eliciting the fastest migration speed, and the migration speed increased with decreasing amplitude. However, when the amplitudes were matched, cells migrated faster on a larger wavelength. This study also highlights the sensitivity of fibroblasts to the topographic orientation, with cells moving faster in the parallel direction of the topography. The overall behavior indicated that the wavelength and amplitude both play an important role in directing cell migration. The collective cell migration was found not to be influenced by altered cell proliferation. These findings provide key insights into topography-triggered cell migration and indicate the necessity for better understanding of material-directed wound healing for designing bio-inductive biomaterials

Non-radiologist-performed abdominal point-of-care ultrasonography in paediatrics - a scoping review

Background Historically, US in the paediatric setting has mostly been the domain of radiologists. However, in the last decade, there has been an uptake of non-radiologist point-of-care US. Objective To gain an overview of abdominal non-radiologist point-of-care US in paediatrics. Materials and methods We conducted a scoping review regarding the uses of abdominal non-radiologist point-of-care US, quality of examinations and training, patient perspective, financial costs and legal consequences following the use of non-radiologist point-of-care US. We conducted an advanced search of the following databases: Medline, Embase and Web of Science Conference Proceedings. We included published original research studies describing abdominal non-radiologist point-of-care US in children. We limited studies to English-language articles from Western countries. Results We found a total of 5,092 publications and selected 106 publications for inclusion: 39 studies and 51 case reports or case series on the state-of-art of abdominal non-radiologist point-of-care US, 14 on training of non-radiologists, and 1 each on possible harms following non-radiologist point-of-care US and patient satisfaction. According to included studies, non-radiologist point-of-care US is increasingly used, but no standardised training guidelines exist. We found no studies regarding the financial consequences of non-radiologist point-of-care US. Conclusion This scoping review supports the further development of non-radiologist point-of-care US and underlines the need for consensus on who can do which examination after which level of training among US performers. More research is needed on training non-radiologists and on the costs-to-benefits of non-radiologist point-of-care US

A review of neurocognitive functioning of children with sex chromosome trisomies: identifying targets for early intervention

Sex chromosome trisomies (SCT) are among the most common chromosomal duplicationsin humans. Due to recent technological advances in non-invasive screening, SCTcan already be detected during pregnancy. This calls for more knowledge about thedevelopment of (young) children with SCT. This review focused on neurocognitivefunctioning of children with SCT between 0 and 18 years, on domains of global intellectualfunctioning, language, executive functioning, and social cognition, in order toidentify targets that could benefit from early treatment.Online databases were used to identify peer-reviewed scientific articles using specificsearch terms. In total 18 studies were included. When applicable, effect sizes werecalculated to indicate clinical significance.Results of the reviewed studies show that although traditionally, the focus has been onlanguage and intelligence (IQ) in this population, recent studies suggest that executivefunctioning and social cognition may also be significantly affected already in childhood.These findings suggest that neuropsychological screening of children diagnosed withSCT should be extended, to also include executive functioning and social cognition.Knowledge about these neurocognitive risks is important to improve clinical care andhelp identify targets for early support and intervention programs to accommodatefor the needs of individuals with SCT.NWO016.165.397Education and Child Studie

Induction of hyperammonia in irradiated hepatoma cells: a recapitulation and possible explanation of the phenomenon

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