Search results for "threshold"
showing 10 items of 688 documents
Influence of nerve branch of origin and extracanalicular extension of the tumor on hearing after middle fossa removal of vestibular schwannoma
2007
Neither nerve branch of origin nor extracanalicular (up to 1 cm) extension of a vestibular schwannoma (VS) influence the postoperative hearing outcome in patients operated via a middle cranial fossa (MCF) approach.To test whether the nerve branch of tumor origin and an extracanalicular, up to 1 cm, tumor extension influences hearing outcome after MCF VS surgery.This was a retrospective case review of 50 patients with postoperative pure-tone audiogram (PTA) performed later than 90 days after surgery. Twenty patients had a superior vestibular nerve (SVN) tumor and 27 patients had an inferior vestibular nerve (IVN) tumor. In three patients the nerve branch of origin of the VS could not be uneq…
Longitudinal Study on Sustained Attention to Response Task (SART): Clustering Approach for Mobility and Cognitive Decline
2022
The Sustained Attention to Response Task (SART) is a computer-based go/no-go task to measure neurocognitive function in older adults. However, simplified average features of this complex dataset lead to loss of primary information and fail to express associations between test performance and clinically meaningful outcomes. Here, we combine a novel method to visualise individual trial (raw) information obtained from the SART test in a large population-based study of ageing in Ireland and an automatic clustering technique. We employed a thresholding method, based on the individual trial number of mistakes, to identify poorer SART performances and a fuzzy clusters algorithm to partition the da…
Genetic and environmental influences on hearing at different frequencies separately for the better and worse hearing ear in older women
2007
The purpose of the present study was to examine the relative contribution of genetic and environmental effects on the air-conducted hearing threshold levels at low (0.125-0.5 kHz), mid (1-2 kHz), and high (4-8 kHz) frequencies separately for the better and worse hearing ear in older women. We also examined the distribution of audiogram configurations. Data was analysed using quantitative genetic modelling. As part of the Finnish twin study on aging (FITSA), hearing was measured in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Approximately every third subject had a flat type, and two-thirds a descending type of audiogram configuration. No significant difference was o…
Hearing as a Predictor of Falls and Postural Balance in Older Female Twins
2009
BACKGROUND: The purpose of the present study was to examine, first, whether hearing acuity predicts falls and whether the potential association is explained by postural balance and, second, to examine whether shared genetic or environmental effects underlie these associations. METHODS: Hearing was measured using a clinical audiometer as a part of the Finnish Twin Study on Aging in 103 monozygotic and 114 dizygotic female twin pairs aged 63-76 years. Postural balance was indicated as a center of pressure (COP) movement in semitandem stance, and participants filled in a fall-calendar daily for an average of 345 days after the baseline. RESULTS: Mean hearing acuity (better ear hearing threshol…
Genetic and environmental influences on hearing in older women.
2007
Background. This study examined the relative contribution of genetic and environmental effects on the air-conducted hearing threshold level (0.5‐4 kHz) and speech recognition threshold level of the better ear as well as self-reported hearing in older women. Methods. Hearing was measured as a part of the Finnish Twin Study on Aging in 103 monozygotic (MZ) and 114 dizygotic (DZ) female twin pairs aged 63‐76 years. Audiometric measured hearing was tested using standardized methods in soundproof conditions. Self-reported hearing was assessed by a structured question. Quantitative genetic modeling was used for data analyses. Results. No significant differences in age, exposure to noise, hearing-…
Pain perception in Parkinson's disease: A systematic review and meta-analysis of experimental studies
2017
While hyperalgesia (increased pain sensitivity) has been suggested to contribute to the increased prevalence of clinical pain in Parkinson's disease (PD), experimental research is equivocal and mechanisms are poorly understood. We conducted a meta-analysis of studies comparing PD patients to healthy controls (HCs) in their response to experimental pain stimuli. Articles were acquired through systematic searches of major databases from inception until 10/2016. Twenty-six studies met inclusion criteria, comprising 1292 participants (PD = 739, HCs = 553). Random effects meta-analysis of standardized mean differences (SMD) revealed lower pain threshold (indicating hyperalgesia) in PD patients d…
Amplified spontaneous emission of pyranyliden derivatives in PVK matrix
2016
One of the well-known red light emitting laser dyes is 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4Hpyran ( DCM ). Amplified spontaneous emission (ASE) has been widely investigated of DCM molecules or its derivatives in polymer or low molecular weight matrix. The main issue for these molecules is aggregation which limits doping concentration in matrix. Lowest ASE threshold values within concentration range of 2 and 4 wt% were obtained. In this work ASE properties of two original DCM derivatives in poly(N-vinylcarbazole) ( PVK ) at various concentrations will be discussed. One of the derivatives is the same DCM dye with replaced butyl groups at electron donor part with bulky try…
Stimulated emission and optical properties of pyranyliden fragment containing compounds in PVK matrix
2017
This work has been supported by National Research program “Multifunctional materials and composites, photonics and nanotechnology (IMIS2)”. Financial support provided by Scientific Research Project for Students and Young Researchers No. SJZ2015/12 realised at the Institute of Solid State Physics, University of Latvia is greatly acknowledged.
Investigating the level of significance of the coherence function in cardiovascular variability analysis
2002
Although the presence of significant coupling between cardiovascular variability series is usually verified according to the threshold value of 0.5 in the coherence function (CF), spectral estimator parameters should also be considered. In this study, the surrogate data technique was introduced to define the level of significance of the CF. The proposed method determined a frequency-dependent threshold over which the hypothesis of zero coherence was rejected. The weighted covariance method and the autoregressive method were used to estimate the CF on simulated series with different degrees of linear coupling and on real cardiovascular data. The threshold was dependent on the type and parame…
Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns
2012
Background The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal’s behaviour, which contributes to an understanding of species’ responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. Methodology/Principal Findings We used speed to determine movement changes of between 8 and 14 GPS…