Search results for "HRES"
showing 10 items of 695 documents
The decision process in forward-masked intensity discrimination: evidence from molecular analyses.
2009
In a two-interval forced-choice intensity discrimination task presenting a fixed increment, the level of the forward masker in interval 1 and interval 2 was sampled independently from the same normal distribution on each trial. Mean and standard deviation of the distribution were varied. Correlational analyses of the trial-by-trial data revealed different decision strategies depending on the relation between mean masker level and standard level. If the two levels were identical, listeners tended to select the interval containing the higher-level masker, behaving like an energy detector at the output of a temporal window of integration. For mean masker level higher than the standard level, m…
Low-Frequency Therapeutic Ultrasound with Varied Duty Cycle: Effects on the Ischemic Brain and the Inner Ear
2009
Sonothrombolysis is a promising modality for acute stroke treatment. In vitro data suggest a duty cycle dependence of sonothrombolytic efficacy of low-frequency applications. The aim of our study was to examine its impact on safety issues in a rat model of middle cerebral artery occlusion. Rats were exposed to transcranial 60-kHz ultrasound with varied duty cycles. To determine effects on the inner ear, the acoustic threshold was determined in additional healthy animals (acoustic evoked potentials). A short duty cycle (20%) resulted in significant adverse effects (ischemic volume, hemorrhage, functional outcome), which was not observed in longer duty cycle (80%). Continuous-wave insonation …
Investigations of the sensory blockade effect of perineurally injected ethanol on the tail nerve of the mouse.
1976
The effect of an alcohol block on the conduction of sensory stimuli in the tail nerve of the mouse was investigated using the perineural injection of solutions of ethanol (35, 40 and 45%). One hundred and fifty white mice of either sex were given 2 X 0.03 ml of the relevant alcohol solution into both sides of the tail. Before and after the injections repeated sensory conduction measurements were made using the rat tail method. Using 35% ethanol a temporary block of pain conduction could be achieved in both sexes. By increasing the concentration to 40 or 45%, a prolongation of the blocking effect and an increase in the accompanying increase of the pain threshold was observed in some animals.…
Sudden sensorineural hearing loss: is there a relationship between routine haematological parameters and audiogram shapes?
2016
Objective: To investigate the relationship between haematological routine parameters and audiogram shapes in patients affected by sudden sensorineural hearing loss (SSNHL). Design: A retrospective study. All patients were divided into four groups according to the audiometric curve and mean values of haematological parameters (haemoglobin, white blood cell, neutrophils and lymphocytes relative count, platelet count, haematocrit, prothrombin time, activated partial thromboplastin time, fibrinogen and neutrophil-to-lymphocite ratio) of each group were statistically compared. The prognostic role of blood profile and coagulation test was also examined. Study sample: A cohort of 183 SSNHL patient…
Temporal weights in loudness: Investigation of the effects of background noise and sound level
2019
Previous research has consistently shown that for sounds varying in intensity over time, the beginning of the sound is of higher importance for the perception of loudness than later parts (primacy effect). However, in all previous studies, the target sounds were presented in quiet, and at a fixed average sound level. In the present study, temporal loudness weights for a time-varying narrowband noise were investigated in the presence of a continuous bandpass-filtered background noise and the average sound levels of the target stimuli were varied across a range of 60 dB. Pronounced primacy effects were observed in all conditions and there were no significant differences between the temporal w…
Central alterations of neuromuscular function and feedback from group III-IV muscle afferents following exhaustive high-intensity one-leg dynamic exe…
2015
The aims of this investigation were to describe the central alterations of neuromuscular function induced by exhaustive high-intensity one-leg dynamic exercise (OLDE, study 1) and to indirectly quantify feedback from group III-IV muscle afferents via muscle occlusion (MO, study 2) in healthy adult male humans. We hypothesized that these central alterations and their recovery are associated with changes in afferent feedback. Both studies consisted of two time-to-exhaustion tests at 85% peak power output. In study 1, voluntary activation level (VAL), M-wave, cervicomedullary motor evoked potential (CMEP), motor evoked potential (MEP), and MEP cortical silent period (CSP) of the knee extensor…
Matters of scale: positive allometry and the evolution of male dimorphisms
2005
J.L.T. was funded by a Biotechnology and Biological Sciences Research Council research fellowship, J.S.K. by the Academy of Finland, and N.R.L. by a Natural Environment Research Council research fellowship. The developmental independence of alternative phenotypes is key to evolutionary theories of phenotypic plasticity and the origins of diversity. Male dimorphisms associated with alternative reproductive tactics are widely cited examples of such facultative expression of divergent fitness optima. Current models for the evolution of male dimorphisms invoke a size-dependent threshold at which the phenotype is reprogrammed. We use predictions derived from allometric modeling to test for the e…
Associations of cardiorespiratory fitness, adiposity, and arterial stiffness with cognition in youth
2020
Abstract Purpose To investigate the associations of cardiorespiratory fitness, adiposity, and arterial stiffness with cognition in 16‐ to 19‐year‐old adolescents. Methods Fifty four adolescents (35 girls; 19 boys) participated in the study. Peak oxygen uptake (V̇O2peak) and peak power output (Wmax) were measured by the maximal ramp test on a cycle ergometer and ventilatory threshold (VT) was determined with ventilation equivalents. Lean mass (LM) and body fat percentage (BF%) were measured using a bioelectrical impedance analysis. Aortic pulse wave velocity (PWVao) and augmentation index (AIx%) were measured by a non‐invasive oscillometric device. Working memory, short term memory, visual l…
Nasal tactile sensitivity in elderly
2010
Conclusion: Although older people varied widely in tactile sensitivity, our results show that tactile thresholds increased with age. Objectives: The aim of this study was to evaluate the effects of aging on nasal tactile sensitivity. Methods: A total of 160 healthy patients aged between 50 and 90 years were included. According to their age, patients were divided into groups (A, B, C, D, E, F, G, and H). From the age of 50, each group included subjects with an age range of 5 years (i.e. group A, 50-55 years; group B, 56-60 years, etc.). Each patient's outcome was assessed through the nasal monofilament test: a set of 20 Semmes-Weinstein monofilaments was used to detect nasal sensitivity for …
Gentamicin increases nitric oxide production and induces hearing loss in guinea pigs.
2008
Objectives/Hypothesis: Gentamicin application is an important therapeutic option for Meniere's disease. However, even if given at intervals, a destruction of the cochlea was often observed in various animal models together with an increased content of nitric oxide (NO) and reactive oxygen species. The present study was undertaken to identify the correlation between hearing threshold alteration and the NO production in the lateral wall and organ of Corti of the guinea pig in response to gentamicin application. Study Design: Prospective animal study in guinea pigs. Methods: A single dose of gentamicin (10 mg/kg body weight) was injected intratympanally into male guinea pigs and the auditory b…