186,509 research outputs found
Imaging and Spectral Analysis of Counterparts to Accreting Black Holes
No full textContains fulltext :
218469.pdf (Publisher’s version ) (Open Access)Radboud University, 03 april 2020Promotor : Jonker, P.G. Co-promotores : Perez Torres, M.A., Heida, M.219 p
STN activity recorded in vitro:Dissociated cell cultures
No full textIn PD, because of the loss of the dopaminergic nigrostriatal connection, the basal ganglia neurons, including the STN, fire by low-frequency oscillatory bursts and fire in synchrony. Under normal conditions, the basal ganglia neurons fire irregularly. The reciprocal pallido-subthalamic connection can be mimicked in vitro and is capable of burst firing. This pattern can be influenced by co-cultures of striatum and cortex (Plenz and Kitai 1999). The observed bursting activity was unaccompanied by synchronous activity in STN slice preparations after the addition of glutamate, dopamine, GABA, or muscarine receptor agonists and/or antagonists. Therefore, synchrony of STN activity in the parkinsonian state is dependent on its extrinsic connections (Wilson et al. 2004). Dissociation of central nervous system areas of P1 (day 1 postnatal) rat pups makes it possible to culture these neurons in a chemically defined medium (Heida 2003). By placing these cultures on MEAs, their spontaneous electrical activity can be recorded. By using polyethylenimine as substrate, a seemingly monolayered network can be created in culture on the MEA (see Rutten et al. 2001 for an overview).</p
HEIDA : Software Examples for Rapid Introduction of Homomorphic Encryption for Privacy Preservation of Health Data
No full textAdequate privacy protection is crucial for implementing modern AI algorithms in medicine. With Fully Homomorphic Encryption (FHE), a party without access to the secret key can perform calculations and advanced analytics on encrypted data without taking part of either the input data or the results. FHE can therefore work as an enabler for situations where computations are carried out by parties that are denied plain text access to sensitive data. It is a scenario often found with digital services that process personal health-related data or medical data originating from a healthcare provider, for example, when the service is delivered by a third-party service provider located in the cloud. There are practical challenges to be aware of when working with FHE. The current work aims to improve accessibility and reduce barriers to entry by providing code examples and recommendations to aid developers working with health data in developing FHE-based applications. HEIDA is available on the GitHub repository: https://github.com/rickardbrannvall/HEIDA.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Direct determination of transition metals in mussel tissue digests using high-performance chelation ion chromatography with monolithic silica based chelating ion exchangers
No full textA new high performance chelation ion chromatography method was developed for the direct separation and detection of selected transition metals in shellfish (mussel) tissue digest samples. Using two different bonded silica monolithic chelating stationary phases, exhibiting differing selectivities for metals of interest, were applied within the method. The bonded chelating chemistries were N-hydroxyethyliminodiacetic (HEIDA) and N-(2-hydroxyethyl)-N-(2-[phosphonomethyl)amino]acetic (HEPMA) acids. Quantitative determination of Mn(II), Cd(II) and Zn(II) concentrations within shellfish tissue (Mytilus edulis), following microwave assisted acid digestion. Post-column detection was achieved using spectophotometric detection at 510 nm after reaction with 4-(2-pyridylazo) resorcinol. The eluents employed were 0.5 M KNO3, pH 2.4, for the HEIDA-bonded stationary phase, and 0.1 M KNO3, pH 2.6, for the HEPMA-bonded monolithic column. The HEPMA phase provided improved resolution between Mn(II) and interfering alkaline earth metal cations compared to the HEIDA-bonded phase. Concentrations of metals were determined using standard addition, and Cd(II), Mn(II), and Zn(II) cations were detected at <10 mg g1, <50 mg g1 and <700 mg g1, respectively. Sample analysis using sector field inductively coupled plasmamass spectrometry (ICP-MS) was carried out to generate comparative data to that obtained using the chromatographic metho
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