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 & Randomized controlled trial. 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.

Stimulation of locomotor activity following injection of dopamine into the nucleus accumbens

Abstract: Recently we have observed that bilateral injection of ergometrine into the nucleus accumbens of rats results in a strong and long-lasting enhancement of locomotor activity (Pijnenburg, Woodruff & van Rossum, 1973). This effect was antagonized by low doses of haloperidol and pimozide. The hypothesis was proposed that this enhanced locomotor activity was elicited by a stimulation of dopamine receptors in the nucleus accumbens. We now report that administration of dopamine directly into the nucleus accumbens of nialamide-pretreated rats produces a pattern of enhanced locomotor activity similar to that seen after ergometrine. Seven male Wistar rats (200-220 g) were implanted with double barrelled cannulas in each side of the nucleus accumbens (coordinates A 9.4, L 1.2 and H -0.6 according to the atlas of Konig & Klippel, 1963). These animals were used for all experiments with 5-8 days between experiments. The animals were subsequently killed and brains were sectioned to determine the position of the cannulas. For details of the experimental procedure see Pijnenburg & others (1973). Injections were made by means of a 5 pl Hamilton syringe with a 31 gauge needle. The injection volume was 0.5 pl. Dopamine HCl and (-)-noradrenaline (-)-hydrogen tartrate were dissolved in saline. Locomotor activity was measured in activity cages, equipped with photoelectric cells and recorded on a cumulative recorder. The rats were always pretreated with the monoamine oxidase inhibitor nialamide (100 mg kg-l i.p.) 18 h before administration of saline, dopamine or noradrenaline. Injection of dopamine ( 5 pg) to each side of the nucleus produced a strong enhancement of locomotor activity, which started in 5 animals within 10 min of injection and lasted for up to 4 h, reaching a peak at about 1 h returning to 0 over the next 3 h with the most rapid decline over the last 30 min. In two rats, in which the injection site was found to be at the border of the nucleus accumbens, stimulation of locomotor activity started after 20 and 30 min respectively and failed to reach the level seen in the other rats. This is probably the reason for the large variability in the results (see Table 1). Injection of noradrenaline (5.0 pg) into each side of the nucleus accumbens of the same rats produced enhanced locomotor activity in 5 of the 7 animals but this was

Factors Affecting Auditory Performance of Postlinguistically Deaf Adults Using Cochlear Implants: An Update with 2251 Patients

Abstract: Objective: To update a 15-year-old study of 800 postlinguistically deaf adult patients showing how duration of severe to profound hearing loss, age at cochlear implantation (CI), age at onset of severe to profound hearing loss, etiology and CI experience affected CI outcome. Study Design: Retrospective multicenter study. Methods: Data from 2251 adult patients implanted since 2003 in 15 international centers were collected and speech scores in quiet were converted to percentile ranks to remove differences between centers. Results: The negative effect of long duration of severe to profound hearing loss was less important in the new data than in 1996; the effects of age at CI and age at onset of severe to profound hearing loss were delayed until older ages; etiology had a smaller effect, and the effect of CI experience was greater with a steeper learning curve. Patients with longer durations of severe to profound hearing loss were less likely to improve with CI experience than patients with shorter duration of severe to profound hearing loss. Conclusions: The factors that were relevant in 1996 were still relevant in 2011, although their relative importance had changed. Relaxed patient selection criteria, improved clinical management of hearing loss, modifications of surgical practice, and improved devices may explain the differences.

Mobility as a Service: A Critical Review of Definitions, Assessments of Schemes, and Key Challenges

Abstract: Mobility as a Service (MaaS) is a recent innovative transport concept, anticipated to induce significant changes in the current transport practices. However, there is ambiguity surrounding the concept; it is uncertain what are the core characteristics of MaaS and in which way they can be addressed. Further, there is a lack of an assessment framework to classify their unique characteristics in a systematic manner, even though several MaaS schemes have been implemented around the world. In this study, we define this set of attributes through a literature review, which is then used to describe selected MaaS schemes and existing applications. We also examine the potential implications of the identified core characteristics of the service on the following three areas of transport practices: travel demand modelling, a supply-side analysis, and designing business model. Finally, we propose the necessary enhancements needed to deliver such an innovative service like MaaS, by establishing the state of art in those fields.