In this experiment, testicle fragments of 14 adult White-eyed Parakeets (Aratinga leucophthalma) were evaluated as for their seasonal reproductive activities using the following quantitative parameters: average thickness of the testicular tunica albuginea, volumetric proportion of tubular and extratubular compartments, average diameter of the seminiferous tubules and corporal weight. Parameters were ...

A study to quantify the UV exposure of vineyard workers was carried out using polysulphone dosimetry. The study took place in Tuscany (Italy) involving 32 vineyard workers and covering three different stages of the vines growth. The level of personal exposure expressed as a function on the available ambient UV ...

The acquisition of hypsodont molars is often regarded as a key innovation in the history of ruminant ungulates. Hypsodont ruminants diversified rapidly during the later Neogene, circa 15-2 Myr ago, and came to dominate the ruminant fossil record in terms of species diversity. Here we show that hypsodont clades had ...

Shining a light on click chemistry: The use of UV-radiation as trigger signal provides a facile means to obtain spatial and temporal control over polymer conjugation reactions in addition to providing a further means of achieving orthogonality in click transformations. In the current contribution, UV-radiation was employed to induce a ...

Optical radiation (light) safety standards can be difficult to use for the evaluation of light hazards to the retina, even for persons experienced in radiometry and photometry. This paper reviews terminology and methodology for evaluating optical radiation hazards to the retina in accordance with international standard ISO 15004-2 Ophthalmic instruments-Fundamental ...

Photochemical damage to the retina occurs for prolonged exposures of intense light. Two action spectra exist for this phenomenon. In rat an action spectrum matching the absorption spectrum of rhodopsin was found. In macaque, the susceptibility for photochemical damage decreased continuously from the UV to long visible wavelengths. Later, such ...

Circadian clocks regulate many molecular and physiological processes in Arabidopsis (Arabidopsis thaliana) with a 24 h period, allowing the timing of these processes to the most appropriate time of the day. The accuracy of timing relies on the synchrony of the clock and the environmental day/night cycle. Visible light is ...

Increased solar ultraviolet radiation (UV) reaches the surface of the Earth as a consequence of a depleted stratospheric ozone layer and changes in factors such as cloud cover, land-use patterns and aerosols. Climate change is expected to result in a 1.1-6.4 °C increase in average temperature by the end of ...

This article is a highlight of the paper by Li et al. in this issue of Photochemistry and Photobiology as well as a short summary of the research on the effects of solar UV-B radiation on primary production in the oceans. Laboratory experiments under controlled conditions using artificial light sources indicate ...

Measurements of impulses produced by bursting balloons are presented. Various sizes of balloons were popped with a mechanical device in an anechoic chamber and recorded with a spherical microphone array. The power responses and directivity of the balloons are analyzed. Results indicate that power responses have two emphasized frequencies which ...

The headmass is a key element in tonpilz transducer design. As an acoustic radiator, a successful headmass must be built from a material that is both light and stiff. To assess the suitability of ceramics for this application, the authors used the mechanical properties of candidate materials to perform a ...

The purpose of this study was to validate through experiments that frequency modulation (FM) of microembolic signatures was principally due to the radiation force. Several experiments were required to prove that such a frequency modulation originates from microdisplacements induced by the radiation force acting on microbubbles. The first experiment was ...

OBJECTIVE: To assess the extent to which UV-A and UV-B radiation can penetrate the human fingernail plate. DESIGN: The Dermalite UV light machine (National Biological, Beachwood, Ohio) was used as the source of UV radiation. The amount of UV-A and UV-B penetrating the nail plate was measured using a radiometer ...

Aqueous photocatalytic oxidation (PCO) of a non-biodegradable sulphonamide antibiotic sulfamethizole was studied. The impacts of photocatalyst dose, initial pH, and substrate concentration in the range from 1 to 100 mg L(-1) were examined with a number of organic and inorganic by-products determined, suggesting the initial break-up of the SMZ molecule ...

The objective of the present study was to investigate the possible electrophysiological time-related changes in auditory pathway during mobile phone electromagnetic field exposure. Thirty healthy rabbits were enrolled in an experimental study of exposure to GSM-900 radiation for 60 min and auditory brainstem responses (ABRs) were recorded at regular time-intervals ...

The risk of falls from height on a construction site increases under conditions which degrade workers' postural control. At elevation, workers depend heavily on sensory information from their feet to maintain balance. The study tested two hypotheses: "sensory enhancement" - sub-sensory (undetectable) random mechanical vibrations at the plantar surface of ...

The aim of this study was to investigate the performance of four frequency weightings for hand-transmitted vibration to predict the incidence of vibration-induced white finger (VWF). In a longitudinal study of vibration-exposed forestry and stone workers (N=206), the incidence of VWF was related to measures of vibration exposure expressed in ...

Assassin bugs (Stenolemus bituberus) hunt web-building spiders by invading the web and plucking the silk to generate vibrations that lure the resident spider into striking range. To test whether vibrations generated by bugs aggressively mimic the vibrations generated by insect prey, we compared the responses of spiders to bugs with ...

High-frequency oscillatory ventilation (HFOV) is thought to protect the lungs of acute respiratory distress syndrome (ARDS) patients. The performance and mechanical characteristics of high-frequency oscillatory ventilators, especially with regard to delivering appropriate tidal volume (V (T)) to compromised lungs, might affect the outcome of patients. We evaluated the performance of ...

Objectives To determine the extent of hand transmitted vibration exposure problems, particularly hand-arm vibration syndrome (HAVS), among construction workers in Malaysia. Methods A cross-sectional study was conducted on a construction site in Kuala Lumpur, Malaysia. 243 workers were recruited. Questionnaire interviews and hand examinations were administered to 194 respondents. Vibration ...

OBJECTIVE: To examine the immediate effects of 2 vibration protocols with different vibration frequencies that yielded the same maximum acceleration (106.75ms(-2)) on muscle peak torque and stiffness of knee extensor and flexor. DESIGN: Randomized crossover study with repeated measures. SETTING: Laboratory setting. PARTICIPANTS: Recreationally active male adults (N=10). INTERVENTION: Participants ...

The bone-anchored-hearing-aid (BAHA) transduces airborne sound into skull vibration. Current bilateral BAHA configurations, for sounds directly facing listeners, will apply forces that are in-phase with each other and directed roughly towards the center of the head. Below approximately 1000 Hz the two cochleae respond in approximately the same direction and ...

Group Ia afferents are activated vigorously with high-frequency tendon vibration and provide excitatory input to the agonist muscle and inhibitory input to the antagonist muscle group via inhibitory interneurons. The purpose of this experiment was to determine whether the afterhyperpolarization (AHP) time course in humans is altered in response to ...

Bushcrickets have a tonotopically organised hearing organ, the so-called crista acustica, in the tibia of the forelegs. This organ responds to a frequency range of about 5-80 kHz and lies behind the anterior tympanum on top of a trachea branch. We analyzed the sound-induced vibration pattern of the anterior tympanum, ...

Lungfishes are the closest living relatives of the tetrapods, and the ear of recent lungfishes resembles the tetrapod ear more than the ear of ray-finned fishes and is therefore of interest for understanding the evolution of hearing in the early tetrapods. The water-to-land transition resulted in major changes in the ...

The question of whether sound vibration of a medium can bring about any kind of molecular or macromolecular events is a long-standing scientific controversy. Although it is known that ultrasonic vibrations with frequencies of more than 1 MHz are able to align certain macromolecules in solution, no effect has yet ...

Whole-body vibration (WBV) may enhance human performance via augmented muscular strength and motor function if used before performance. Because warm-up is a crucial aspect of preparation for performance, it remains unknown if WBV may enhance bat speed. The purpose of this study was to investigate the effect of WBV warm-up ...

BACKGROUND: High-frequency jet ventilation is an optimal mode of ventilation for many surgical procedures of the trachea and larynx but has limited monitoring modalities to assess adequacy of oxygenation and/or ventilation. Respiratory inductance plethysmography is a noninvasive monitor of chest and abdominal wall movement with well-established applications in the sleep ...

We experimentally study a monolayer of vibrated disks with a built-in polar asymmetry which enables them to move quasibalistically on a large persistence length. Alignment occurs during collisions as a result of self-propulsion and hard core repulsion. Varying the amplitude of the vibration, we observe the onset of large-scale collective ...

Replying to: U. Wittrock 466, 10.1038/nature09156 (2010)Wittrock suggests that a stylohyal-tympanic connection in laryngeally echolocating bats as the one described in our studycould transmit laryngeal vibrations to both ears. This could represent a 'local oscillator', forming part of a heterodyne-like detection system for precise target detection and localization. The essence ...

Dual-axis cervical accelerometry is an emerging approach for the assessment of swallowing difficulties. However, the baseline signals, i.e., vibration signals with only quiet breathing or apnea but without swallowing, are not well understood. In particular, to comprehend the contaminant effects of head motion on cervical accelerometry, we need to study ...

Soft-tissue vibrations can be used to quantify selected properties of human tissue and their response to impact. Vibrations are typically quantified using high-speed motion capture or accelerometry. The aim of this study was to compare the amplitude and frequency of soft-tissue vibrations during running when quantified by highspeed motion capture ...

High-frequency percussive ventilation (HFPV) by the VDR-4(R) has been a successful mode of ventilation in the management of inhalation injuries for nearly 20 years. A limitation of the standard VDR-4 ventilator circuit is that the sliding venturi manifold is heavy in weight and is normally connected directly to the patient's ...

Individuals of the insect order Mantophasmatodea use species-specific substrate vibration signals for mate recognition and location. In insects, substrate vibration is detected by mechanoreceptors in the legs, the scolopidial organs. In this study we give a first detailed overview of the structure, sensory sensitivity, and function of the leg scolopidial ...

We study a nanoscale system composed of one corrugated cylinder (pinion) placed between two corrugated plates (racks). The pinion and racks have no mechanical contact, but are coupled via the lateral Casimir force-one of the most spectacular consequences of quantum fluctuations of the electromagnetic field. The noncontact design of the ...

Modulation of lower limb somatosensory information by tendon or plantar vibration produces directionally specific, vibration-induced falling reactions that depend on the tendon or the region of the sole that is vibrated. This study characterized the effects of different patterns of plantar cutaneo-muscular vibration and bilateral Achilles tendon vibration (ATV) on ...

Excited-state relaxation of cis- and trans-stilbene is traced with femtosecond stimulated Raman spectroscopy, exploiting S(n) <-- S(1) resonance conditions. For both isomers, decay in Raman intensity, shift of spectral positions, and broadening of the bands indicate intramolecular vibrational redistribution (IVR). In n-hexane this process effectively takes 0.5-0.7 ps. Analysis of ...

This study applied bone-conducted vibration (BCV) stimuli at various repetition rates to investigate the effects of repetition rate on both ocular and cervical vestibular-evoked myogenic potentials (oVEMPs and cVEMPs). Twenty-five healthy subjects underwent oVEMP tests in BCV mode at repetition rates of 1, 5, 10, 20, 30 and 40Hz. The ...

Accumulating evidence indicates that mammalian cochlear frequency-position maps (location of maximum vibration of the basilar membrane as a function of frequency) depend on the physiological condition of the inner ear. Cochlear damage desensitizes the ear, after the damage the original location of maximum vibration is tuned to a lower sound ...

OBJECTIVE: The current frequency weighting proposed in the International Standards Organization-5349 standard may underestimate the risk of injury associated with exposure to vibration >100 Hz. The goal of this study was to assess the frequency-dependent responses of the peripheral vascular system to repeated bouts of vibration. METHODS: The effects of ...

The purpose of this study was to compare the vocal fold vibratory characteristics of ex vivo bovine, canine, ovine, and porcine larynges to human male and female vocal fold vibrations to determine the best model organism for laryngeal studies concerning vibratory and kinetic characteristics. Prospective experimental. High-speed videos of phonation ...

SUMMARY: Fifteen anaesthetists attempted to intubate the trachea of a manikin lying supine on the ground using the Airway Scope, Airtraq or Macintosh laryngoscope in three simulated conditions: (1) in room light; (2) in the dark and (3) in daylight. The main outcome measure was the time to ventilate the ...

To investigate prospectively the relation between vibration-induced sensory dysfunction and measures of daily exposure to hand-transmitted vibration (HTV). Thermal perception thresholds for warmth and cold (TPT in °C) and vibrotactile perception thresholds (VPT in dB) at 31.5 and 125 Hz were measured at the fingertips of digit II (for the median ...

Swallowing dysfunction, or dysphagia, is a serious condition that can result from any structural or neurological impairment (such as stroke, neurodegenerative disease or brain injury) that affects the swallowing mechanism. The gold-standard method of instrumental swallowing assessment is an x-ray examination known as the videofluoroscopic swallowing study, which involves radiation ...

Vibratory auditory stimulation or bone conduction (BC) reaches the inner ear through both osseous and non-osseous structures of the head, but the contribution of the different pathways of BC is still unclear. In this study, BC thresholds in response to stimulation at several different locations including the eye were assessed, ...

A cryogenic sapphire oscillator (CSO) has been implemented at 11.2 GHz using a low-vibration design pulsetube cryocooler. Compared with a state-of-the-art liquid helium cooled CSO in the same laboratory, the square root Allan variance of their combined fractional frequency instability is sigma(y) = 1.4 x 10(-15)tau(-1/2) for integration times 1 ...

This paper describes two methods for vibration damping in a broad band frequency range using a piezoelectric patch. The first method, applied to an adaptive device, uses a bias (static voltage control), which applies stresses or releases stresses in a piezoelectric component to modify its mechanical characteristics and thereby its ...

This study investigates the performance of a touch screen, mouse and trackball in a motion environment. A Stewart motion platform was used to generate a six-degree-of-freedom motion environment. Participants were placed in an environment where vehicle vibration was simulated. Tasks were used according to Fitts' Law to obtain the movement ...

The piezoresponse (PR) amplitude and phase signals for antiparallel ferroelectric domains were investigated with different feedback parameters. It is found that the drive frequency and setpoint can strongly alternate the PR image contrast, while the drive phase can be considered as a constant adding to the PR phase signal. The ...

Whole-body vibration experiments with subjects under vertical vibration were performed to examine and evaluate effects of backrest inclination on vibration transmitted through seats to the human body by using biodynamic response parameters represented by apparent mass (APMS) and vibration power absorption (VPA). The biodynamic response parameters of twelve male subjects, ...