Cochlear filtering results in earlier responses to high than to low frequencies. This study examined potential perceptual correlates of cochlear delays by measuring the perception of relative timing between tones of different frequencies. A brief 250-Hz tone was combined with a brief 1-, 2-, 4-, or 6-kHz tone. Two experiments ...

The question whether or not double basses can benefit from a compliant and radiating stage floor in the low end of their tonal register, similar to the well-known tuning fork-tabletop effect, was examined through field experiments in five concert halls. The topic comprises several aspects: (1) How well the mechanical ...

Jatropha curcas (L.) trees under north Indian conditions (Lucknow) produce fruits in two major flushes, once during autumn-winter (October-December). The leaves at this time are at the senescence stages and already shedding. The second flush of fruit setting occurs during the summer (April-June) after the leaves have formed during spring ...

Photoperiod, or the daily sequence of light and dark, has dramatic effects on many physiological systems across animal species. Light patterns alter melatonin secretion profiles and, subsequently, the release profiles and circulating concentrations of a number of hormones that influence a variety of physiological responses. Although the impact of photoperiod ...

Fluorescence imaging of transmembrane voltage-sensitive dyes is used to study electrical activation in cardiac tissue. However, the fluorescence signals typically have low signal to noise ratios and may be contaminated with motion artifact. In this report, we introduce a new processing approach for fluoresced transmembrane potentials (fTmps) that is based ...

Autofluorescence (primary fluorescence (AF)) of fruiting bodies and stems of the fungus Morchella conica var. rigida was studied by fluorescence microscopy including sporangia and ascospores. The ascospores were characterized by a weak green-yellow AF at blue excitation. Using a green excitation, no AF was observed. The hyphae located under the ...

The time-resolved fluorescence intensity fluctuations from single, immobilized complexes of the main light-harvesting complex (LHCII) of plants were investigated in different pH environments close to room temperature and under different light conditions. The efficiency of light harvesting, which was represented by complexes typically residing for long periods in strongly fluorescing ...

We present a simple method to resolve discrete intensity shifts from time-resolved single-molecule emission data. This new method uses multiples of the standard deviation of the measured intensities that are integrated into short time bins. By applying the technique to trimeric units of the main light-harvesting complex (LHCII) of plants, ...

Switchable supramolecular self-assemblies on the basis of interaction between melamine group containing photochromic diarylethene unit (DTE) and naphthalimide derivate (1) were designed and fabricated. 1 can gelate several aprotic solvents with different morphologies. The gel turned into partial gel in ethyl acetate with the addition of DTE as a guest ...

We demonstrate a compact, low cost and practical fluorescence detection system for lab-on-a-chip applications. The system comprises a commercially available InGaN light emitting diode (501 nm) as light source, an organic or silicon photodiode detector, absorptive dye coated colour filters and linear and reflective polarisers. An injection moulded polystyrene microfluidic ...

Initially developed so that an individual could be recognized in mark-recapture studies of aquatic animals, fluorescent visible implant elastomer (VIE) tags are used here for a new application in ethometry: the study of the behavior of transparent animals in dim light or in darkness using automatic tracking technology. The application ...

In this paper, a compact and inexpensive light emitting diode induced fluorescence (LED-IF) detector with simplified optical configuration was developed and assembled in an integrated microfluidic device for microscale electrophoresis. The facile detector mainly consisted of an LED, a focusing pinhole, an emission filter and a photodiode, and was encapsulated ...

Under specific light illumination, particularly ultraviolet (UV) and near-UV light stimulation, the skin produces both specular light reflectance and, possibly, specific fluorescent emission. These properties offer diagnostic clues and disclose some peculiar functions of the skin. A series of superficial infections (erythrasma, some tinea capitis types, tinea/pityriasis versicolor, dermatophytoses, etc.) ...

Herein, we unveiled the first zinc complex based chemosensor for cyanide (CN(-)). The changed visual color from light reddish orange to dark reddish orange, the enhanced fluorescence intensity at approximately 600 nm and the near-linear correlation A(495)/A(325)versus the cyanide concentration were observed after adding CN(-).

: To determine whether an "optimal" distortion product otoacoustic emission (DPOAE) protocol that (1) used optimal stimulus levels and primary-frequency ratios for each f2, (2) simultaneously measured 2f2 - f1 and 2f1 - f2 distortion products, (3) controlled source contribution, (4) implemented improved calibration techniques, (5) accounted for the influence ...

Strong and stable visible-light-emitting boron nitride nanotube (BNNT)/biomolecule nanohybrids were successfully fabricated via noncovalent functionalization of BNNTs with flavin mononucleotides (FMN). Atomic force microscopy showed excellent dispersion of the nanohybrids in aqueous solution. Infrared absorption spectroscopy revealed strong π-π stacking interactions between FMN and BNNT sidewalls. Importantly, the fluorescence spectra ...

Observing individual molecules in a complex environment by fluorescence microscopy is becoming increasingly important in biological and medical research, for which critical reduction of observation volume is required. Here, we demonstrate the use of vertically aligned silicon dioxide nanopillars to achieve below-the-diffraction-limit observation volume in vitro and inside live cells. ...

The lower oxygen limit (LOL) in plants may be identified through the measure of respiratory gases [i.e. the anaerobic compensation point (ACP) or the respiratory quotient breakpoint (RQB)], but recent work shows it may also be identified by a sudden rise in dark minimum fluorescence (F (o)). The interrelationship between ...

Multi-coloured homologues of the green fluorescent protein generate some of the most striking visual phenomena in the ocean. Despite their natural prominence in reef-building corals and widespread use in biotechnology, their biological role remains obscure. Here, we experimented with larvae of Acropora millepora to determine what can be learned about ...

UV light below 300 nm is shown to generate the first photocycle intermediate in the blue light photoreceptor Photoactive Yellow Protein. Fluorescence and ultrafast transient absorption measurements indicate two excitation pathways: UV-B absorption by the chromophore and Fluorescence Resonant Energy Transfer (FRET) from tryptophan and tyrosine residues.

Chlorophyll a fluorescence is a highly sensitive, non-destructive, and reliable tool for measuring, rather quickly, photosynthetic efficiency, particularly of Photosystem II (PSII), the water-plastoquinone oxidoreductase. We briefly review here the connection between the fast (up to 2s) chlorophyll fluorescence rise and PSII, as well as the empirical use of the ...

Hope CK, de Josselin de Jong E, Field MRT, Valappil SP, Higham SM. Photobleaching of red fluorescence in oral biofilms. J Periodont Res 2010; doi: 10.1111/j.1600-0765.2010.01334.x. © 2010 John Wiley & Sons A/S Background and Objective:  Many species of oral bacteria can be induced to fluoresce due to the presence ...

The self-assembly of a blue-emitting light-harvesting organogelator and specifically designed highly fluorescent tetracenes yields nanofibers with tunable emissive properties. In particular, under near-UV excitation, white light emission is achieved in organogels and dry films of nanofibers. Confocal fluorescence microspectroscopy demonstrates that each individual nanofiber emits white light. A kinetic study ...

A conceptually new "light-up" biosensor with a high specificity for d-glucose (Glu) in aqueous media has been developed. The emission from a tetraphenylethene (TPE)-cored diboronic acid (1) was greatly boosted when the fluorogen was oligomerized with Glu because of restriction of the intramolecular rotations of the aryl rotors of TPE ...

Concentration is a key determining factor in the fluorescence properties of organic fluorophores. We studied self-quenching of disodium fluorescein (uranin) fluorescence in polyvinyl alcohol (PVA) thin films. The concentration dependent changes in brightness and anisotropy were followed by a lifetime decrease. We found that at a concentration of 0.54 M, ...

This work describes a method for limiting internal losses of a luminescent solar concentrator (LSC) due to reabsorption through patterning the fluorescent dye doped coating of the LSC. By engineering the dye coating into regular line patterns with fill factors ranging from 20 - 80%, the surface coverage of the ...

The tympanal organ of the bushcricket Mecopoda elongata emits pronounced distortion-product otoacoustic emissions (DPOAEs). Their characteristics are comparable to those measured in other insects, such as locusts and moths, with the 2f1-f2 emission being the most prominent one. Yet the site of their generation is still unclear. The spatial separation ...

The aim of this study was to investigate the functionality of cochlear active mechanisms in normal-hearing subjects affected by Williams syndrome (WS). Transient evoked otoacoustic emissions (TEOAEs) were recorded in a group of young WS subjects and a group of typically developing control subjects, all having normal-hearing thresholds and normal ...

Firefly luciferase utilizes the chemical energy of ATP and oxygen to convert its substrate, D-luciferin, into an excited-state oxyluciferin molecule. Relaxation of this molecule to the ground state is responsible for the yellow-green light emission. Synthetic cyclic alkylaminoluciferins that allow robust red-shifted light emission with the modified luciferase Ultra-Glo are ...

To develop normative data for wideband middle-ear reflectance in a newborn hearing-screening population and to compare test performance with 1-kHz tympanometry for prediction of otoacoustic emission (OAE) screening outcome. Wideband middle-ear reflectance (using both tone and chirp stimuli from 0.2 to 6 kHz), 1-kHz tympanometry, and distortion-product (DP) OAEs were ...

The aim of this study was to investigate whether distortion product otoacoustic emissions (DPOAEs) are a suitable means for detecting changes in outer hair cell (OHC) functionality due to exposure to three hours of discotheque music and whether efferent reflex strength of the medial olivocochlear bundle is able to predict ...

Subclinical conductive hearing losses (CHLs) can affect otoacoustic emissions and therefore limit their potential in the assessment of the cochlear function. Theoretical considerations to estimate a minor CHL from DPOAE measurements [Kummer et al. (2006). HNO 54, 457-467] are evaluated experimentally. They are based on the fact, that the level ...

Distortion product otoacoustic emissions (DPOAEs) are traditionally evoked by two-tone stimuli. In this study, emission data from Mongolian gerbils are reported that were obtained with stimuli consisting of six to 10 tones. The stimuli were constructed by replacing one of the tones of a tone pair by a narrowband multitone ...

Several lines of evidence suggest that medial olivocochlear (MOC) efferent neurons modify cochlear output to improve signal detection in noise. In animal models, stimulation of MOC efferents reduces the amount of compression in basilar membrane (BM) growth functions. Linearization of BM growth functions may assist in extending the neural response ...

Upconverting luminescent nanoparticles (UCNPs) display the unique property of emitting visible light following photoexcitation with near-infrared laser light. This results in features such as virtually zero autofluorescence of (biological) matter and easy separation of the emission peaks from stray light. Other features include rather narrow emission bands, very high chemical ...

The middle ear transmits sound efficiently from the air in the ear canal (EC) to the fluid filled cochlea. In gerbil, middle ear transmission produces a constant pressure gain between the EC and the cochlea of ∼25 dB from 2 to 40 kHz, and a delay-like phase corresponding to a ...

Focused ultrasound therapy can be enhanced with microbubbles by thermal and cavitation effects. However, localization of treatment is difficult as bioeffects can occur outside of the target region. Spatial control of bubbles can be achieved by ultrasound-induced conversion of liquid perfluorocarbon droplets to gas bubbles. This study was undertaken to ...

Distortion-product otoacoustic emission (DPOAE) stimulus calibrations are typically performed in sound pressure level (SPL) before DPOAE measurements. These calibrations may yield unpredictable DPOAE response levels, presumably because of the presence of standing waves in the ear canal. Forward pressure level (FPL) has been proposed as an alternative method for stimulus ...

Acute acoustic trauma (AAT) is a sudden sensorineural hearing loss caused by exposure of the hearing organ to acoustic overstimulation, typically an intense sound impulse, hyperbaric oxygen therapy (HOT), which favors repair of the microcirculation, can be potentially used to treat it. Hence, this study aimed to assess the effects ...

DPOAE (2f(1)-f(2)) phase was measured across a 3-octave frequency range from two groups of newborns using ER10B+ and ER10C probe microphones. A marked phase shift was noted in the mid-to-high frequency range for newborn data recorded with the ER10C only. In contrast, the ER10B+ produced phase that was approximately invariant ...

This composite article is intended to give the experts in the field of cochlear mechanics an opportunity to voice their personal opinion on the one mechanism they believe dominates cochlear amplification in mammals. A collection of these ideas are presented here for the auditory community and others interested in the ...

Spontaneous otoacoustic emissions (SOAEs) and synchronized spontaneous otoacoustic emissions (SSOAEs) were recorded using both the standard closed-canal method of recording and a novel open-canal method which involved suspending the probe at the entrance to the ear canal with no occluding tip. In both conditions, a probe tube microphone was inserted ...

The hearing status of an experimental animal is typically assessed in the laboratory setting by the combined use of auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAEs), carried out in succession, with the former assay preceding the latter. This study reports a cautionary finding that the use of ...

Cochlear microphonics are electrical stimulus responses of the inner ear. They are generated by mechanical displacement of the hair cells caused by acoustic stimulation and can be recorded from the cochlear promontory via a needle electrode. In individuals with post-meningitic deafness, fibrous obliteration or ossification of the cochlea may occur. ...

The aim of this study was to analyze the fine structure of transient evoked otoacoustic emissions (TEOAEs) and contralateral suppression effects in tinnitus subjects with normal hearing in order to assess whether a minor cochlear or efferent dysfunction, possibly limited in narrow cochlear regions, might play a role in tinnitus. ...

Auditory discrimination is limited by the performance of the cochlea whose acute sensitivity and frequency tuning are underpinned by electromechanical feedback from the outer hair cells. Two processes may underlie this feedback: voltage-driven contractility of the outer hair cell body and active motion of the hair bundle. Either process must ...

The auditory sensory organ, the cochlea, not only detects but also generates sounds. Such sounds, otoacoustic emissions, are widely used for diagnosis of hearing disorders and to estimate cochlear nonlinearity. However, the fundamental question of how the otoacoustic emission exits the cochlea remains unanswered. In this study, emissions were provoked ...

To determine the output levels of a commercially available MPEG layer-3 (MP3) player and to evaluate changes in hearing after 1 hour of listening to the MP3 player. First, A-weighted sound pressure levels (measured in decibels [dBA]) for 1 hour of pop-rock music on an MP3 player were measured on ...

The hearing status of workers (N = 233) in a printing office was assessed twice within seventeen months by pure-tone audiometry and otoacoustic emissions (OAEs). One of the questions was how a quality criterion of OAE-measurements based on a minimum signal-to-noise-ratio (SNR) would affect the applicability on the entire population. ...

Previous studies have shown a high within-subject correspondence between distortion product otoacoustic emission (DPOAE) input/output (I/O) curves and behaviorally inferred basilar membrane (BM) I/O curves for frequencies above approximately 2 kHz. For lower frequencies, DPOAE I/O curves contained notches and plateaus that did not have a counterpart in corresponding behavioral ...