109 research outputs found

    Land-Use and Transport

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    Numerous studies of the interaction between land use and transport have been carried out in the past. In this paper we evaluate a selection of Dutch studies. Before reviewing the studies, we present a conceptual model for passenger transport (section 2), give an overview of the way in which land-use influences travel behaviour (section 3). We also give an overview of transport in Dutch land-use policy plans (section 4) and a categorisation of research (section 5). We then review empirical studies (section 6) and model-simulation studies (section 7) of the impact of land-use on transport. This is followed by a synthesis of the results and look at the transferability of results to other countries (section 8), a discussion of the policy implications of our findings (section 9) and some suggestions for further research (section 10)

    Three Decades of Transport Infrastructure Development and Travel Behaviour Change in the Netherlands

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    It is argued that improvements in the supply of transport infrastructure networks affect accessibility, which in turn influences the distribution of land uses, activities linked to them and eventually the travel behaviour of individuals. Identifying the extent and rate of change in travel behaviour as a response to change in spatial and socio-demographic characteristics, requires long-term empirical investigation of their interrelation. The assessment of long-term trends can provide guidelines for the type, extent and location of future investments in transport and land use development. This paper explores trends in access to transport infrastructure (proximity to the railway stations), land use (location of inhabitants), socio-demographic characteristics of the travellers and travel behaviour (distance travelled by car, train and active modes and total number of trips per day) over three decades. It uses data from Dutch National Travel Surveys at seven time points of five-year intervals from 1980 to 2010 in the Randstad, the Netherlands. The results indicate that while the total number of trips per day has remained stable over time, total kilometres travelled has risen until the mid-1990s after which it has witnessed a decrease. Further more, the findings suggest that train is increasingly used for travelling longer distances and the location of home municipality and proximity to train stations (within a distance of 500 to 1250 m) are closely related to the total train kilometres travelled

    Self-reported music perception is related to quality of life and self-reported hearing abilities in cochlear implant users

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    Objectives To investigate the relationship between self-reported music perception and appreciation and (1) quality of life (QoL), and (2) self-assessed hearing ability in 98 post-lingually deafened cochlear implant (CI) users with a wide age range. Methods Participants filled three questionnaires: (1) the Dutch Musical Background Questionnaire (DMBQ), which measures the music listening habits, the quality of the sound of music and the self-assessed perception of elements of music; (2) the Nijmegen Cochlear Implant Questionnaire (NCIQ), which measures health-related QoL; (3) the Speech, Spatial and Qualities (SSQ) of hearing scale, which measures self-assessed hearing ability. Additionally, speech perception was behaviorally measured with a phoneme-in-word identification. Results A decline in music listening habits and a low rating of the quality of music after implantation are reported in DMBQ. A significant relationship is found between the music measures and the NCIQ and SSQ; no significant relationships are observed between the DMBQ and speech perception scores. Conclusions The findings suggest some relationship between CI users' self-reported music perception ability and QoL and self-reported hearing ability. While the causal relationship is not currently evaluated, the findings may imply that music training programs and/or device improvements that improve music perception may improve QoL and hearing ability

    The Effect of Static Ear Canal Pressure on Human Spontaneous Otoacoustic Emissions: Spectral Width as a Measure of the Intra-cochlear Oscillation Amplitude

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    Spontaneous otoacoustic emissions can be detected as peaks in the Fourier spectrum of a microphone signal recorded from the ear canal. The height, center frequency, and spectral width of SOAE peaks changed when a static pressure was applied to the ear canal. Most commonly, with either increasing or decreasing static pressure, the frequency increased, the amplitude decreased, and the width increased. These changes are believed to result from changes in the middle ear properties. Specifically, reduced middle ear transmission is assumed to attenuate the amplitude of emissions. We reconsidered this explanation by investigating the relation between peak height and width. We showed that the spectral width of SOAE peaks is approximately proportional to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}1/peak  height 1/\sqrt {{{\hbox{peak}}\;{\hbox{height}}}} \end{document}. This is consistent with a (Rayleigh) oscillator model in which broadening of the SOAE peak is caused by broadband intra-cochlear noise, which is assumed to be independent of static ear canal pressure. The relation between emission peak height and width implicates that the intra-cochlear oscillation amplitude attentuates relative to the intra-cochlear noise level when a static ear canal pressure is applied. Apparently, ear canal static pressure directly affects the active mechanics in the inner ear

    Carbamazepine induces upward frequency shifts of spontaneous otoacoustic emissions

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    In three subjects, we measured spontaneous otoacoustic emissions (SOAEs) when they were using carbamazepine (CBZ), and compared this to the SOAE measurement when they were not using CBZ. We observed 14 SOAEs showing a consistent upward shift of center frequency, related to CBZ intake. On average, the magnitude of the frequency shift increased with increasing frequency. The magnitude of the shift was 30-104 Hz, at frequencies ranging from 1.3 to 2.3 kHz, corresponding to a shift between 2.3 and 4.5%. Compared to other causes and manipulations known to change SOAE frequency, these shifts are relatively large. The underlying mechanism is most likely an increased stiffness of the cochlear partition. This would also explain the downward pitch shift due to CBZ, which has been reported by subjects with absolute pitch

    Comparison of Two Music Training Approaches on Music and Speech Perception in Cochlear Implant Users

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    In normal-hearing (NH) adults, long-term music training may benefit music and speech perception, even when listening to spectro-temporally degraded signals as experienced by cochlear implant (CI) users. In this study, we compared two different music training approaches in CI users and their effects on speech and music perception, as it remains unclear which approach to music training might be best. The approaches differed in terms of music exercises and social interaction. For the pitch/timbre group, melodic contour identification (MCI) training was performed using computer software. For the music therapy group, training involved face-to-face group exercises (rhythm perception, musical speech perception, music perception, singing, vocal emotion identification, and music improvisation). For the control group, training involved group nonmusic activities (e.g., writing, cooking, and woodworking). Training consisted of weekly 2-hr sessions over a 6-week period. Speech intelligibility in quiet and noise, vocal emotion identification, MCI, and quality of life (QoL) were measured before and after training. The different training approaches appeared to offer different benefits for music and speech perception. Training effects were observed within-domain (better MCI performance for the pitch/timbre group), with little cross-domain transfer of music training (emotion identification significantly improved for the music therapy group). While training had no significant effect on QoL, the music therapy group reported better perceptual skills across training sessions. These results suggest that more extensive and intensive training approaches that combine pitch training with the social aspects of music therapy may further benefit CI users

    The musician effect:does it persist under degraded pitch conditions of cochlear implant simulations?

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    Cochlear implants (CIs) are auditory prostheses that restore hearing via electrical stimulation of the auditory nerve. Compared to normal acoustic hearing, sounds transmitted through the CI are spectro-temporally degraded, causing difficulties in challenging listening tasks such as speech intelligibility in noise and perception of music. In normal hearing (NH), musicians have been shown to better perform than non-musicians in auditory processing and perception, especially for challenging listening tasks. This "musician effect" was attributed to better processing of pitch cues, as well as better overall auditory cognitive functioning in musicians. Does the musician effect persist when pitch cues are degraded, as it would be in signals transmitted through a CI? To answer this question, NH musicians and non-musicians were tested while listening to unprocessed signals or to signals processed by an acoustic CI simulation. The task increasingly depended on pitch perception: (1) speech intelligibility (words and sentences) in quiet or in noise, (2) vocal emotion identification, and (3) melodic contour identification (MCI). For speech perception, there was no musician effect with the unprocessed stimuli, and a small musician effect only for word identification in one noise condition, in the CI simulation. For emotion identification, there was a small musician effect for both. For MCI, there was a large musician effect for both. Overall, the effect was stronger as the importance of pitch in the listening task increased. This suggests that the musician effect may be more rooted in pitch perception, rather than in a global advantage in cognitive processing (in which musicians would have performed better in all tasks). The results further suggest that musical training before (and possibly after) implantation might offer some advantage in pitch processing that could partially benefit speech perception, and more strongly emotion and music perception

    An auditory brainstem implant for treatment of unilateral tinnitus:protocol for an interventional pilot study

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    INTRODUCTION: Tinnitus may have a very severe impact on the quality of life. Unfortunately, for many patients, a satisfactory treatment modality is lacking. The auditory brainstem implant (ABI) was originally indicated for hearing restoration in patients with non-functional cochlear nerves, for example, in neurofibromatosis type II. In analogy to a cochlear implant (CI), it has been demonstrated that an ABI may reduce tinnitus as a beneficial side effect. For tinnitus treatment, an ABI may have an advantage over a CI, as cochlear implantation can harm inner ear structures due to its invasiveness, while an ABI is presumed to not damage anatomical structures. This is the first study to implant an ABI to investigate its effect on intractable tinnitus. METHODS AND ANALYSIS: In this pilot study, 10 adults having incapacitating unilateral intractable tinnitus and ipsilateral severe hearing loss will have an ABI implanted. The ABI is switched on 6 weeks after implantation, followed by several fitting sessions aimed at finding an optimal stimulation strategy. The primary outcome will be the change in Tinnitus Functioning Index. Secondary outcomes will be tinnitus burden and quality of life (using Tinnitus Handicap Inventory and Hospital Anxiety and Depression Scale questionnaires), tinnitus characteristics (using Visual Analogue Scale, a tinnitus analysis), safety, audiometric and vestibular function. The end point is set at 1 year after implantation. Follow-up will continue until 5 years after implantation. ETHICS AND DISSEMINATION: The protocol was reviewed and approved by the Institutional Review Board of the University Medical Centre Groningen, The Netherlands (METc 2015/479). The trial is registered at www.clinicialtrials.gov and will be updated if amendments are made. Results of this study will be disseminated in peer-reviewed journals and at scientific conferences. TRIAL REGISTRATION NUMBER: NCT02630589. TRIAL STATUS: Inclusion of first patient in November 2017. Data collection is in progress. Trial is open for further inclusion. The trial ends at 5 years after inclusion of the last patient

    Intragraft interleukin 2 mRNA expression during acute cellular rejection and left ventricular total wall thickness after heart transplantation

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    OBJECTIVE: To assess whether diastolic graft function is influenced by intragraft interleukin 2 (IL-2) messenger RNA (mRNA) expression in rejecting cardiac allografts. DESIGN: 16 recipients of cardiac allografts were monitored during the first three months after transplantation. The presence of IL-2 mRNA in endomyocardial biopsies (n = 123) was measured by reverse transcriptase polymerase chain reaction. To determine heart function, concurrent M mode and two dimensional Doppler echocardiograms were analysed. RESULTS: Histological signs of acute rejection (International Society for Heart and Lung Transplantation (ISHLT) rejection grade > 2) were strongly associated with IL-2 mRNA expression (IL-2 mRNA was present in 12 of 20 endomyocardial biopsies (60%) with acute rejection and in 24 of 103 endomyocardial biopsies (23%) without acute rejection, p = 0.002). No significant relation was found between either histology or IL-2 mRNA expression alone and the studied echocardiographic parameters. However, stratification of the echocardiographic data into those of patients with and those without acute rejection showed that during acute rejection IL-2 mR

    Intragraft heme oxygenase-1 and coronary artery disease after heart transplantation

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    Peri-operative tissue injury triggers the development of Transplant Coronary Artery Disease (TCAD). Animal studies have shown that induction of heme oxygenase (HO)-1 protects the donor organ from the development of TCAD. To investigate the role of HO-1 in TCAD after clinical heart transplantation, we measured intragraft mRNA expression of HO-1, HIF-1α, TGF-β, FLIP, and the Bcl-2/Bax balance. Immunohistochemical staining of HO-1 was performed to determine its origin. Myocardial biopsies taken at the end of the transplantation procedure (time 0), at 1 week and at 10 months after transplantation were studied from recipients with or without angiographic signs of accelerated TCAD, diagnosed after 1 year. At time 0, no differences in mRNA expression for any of the measured parameters were found between TCAD positive and negative patients. At 1 week, mRNA expression of HO-1 and TGF-β was higher in grafts that developed accelerated TCAD (p=0.001 and p=0.0002). These higher mRNA levels were accompanied by a pro-apoptotic shift in Bcl-2/Bax (p=0.02), suggesting proneness for apoptosis via the mitochondrial pathway. Immunohistochemical staining showed that HO-1 was mainly produced by infiltrating macrophages. At 10 months, again HO-1 and TGF-β levels were high in TCAD positive patients (p=0.02 and p=0.05), but the expression of apoptotic markers was comparable at this time point. Our results suggest that a higher HO-1 by macrophages in our patient population might be an adaptive response to tissue injury and inflammation, reflecting damage due to the transplantation procedure that finally results in TCAD
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