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Results 501 - 550 of 911
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Rascón Brenda - - 2005
Resting insects are extremely tolerant of hypoxia. However, oxygen requirements increase dramatically during flight. Does the critical atmospheric P (O)(2) (P(c)) increase strongly during flight, or does increased tracheal conductance allow even flying insects to possess large safety margins for oxygen delivery? We tested the effect of P(O)(2) on resting ...
Kehoe E James - - 2005
Extinguishing a conditioned response (CR) has entailed separating the conditioned stimulus (CS) from the unconditioned stimulus (US). This research reveals that elimination of the rabbit (Oryctolagus cuniculus) nictitating membrane response occurred during continuous CS-US pairings. Initial training contained a mixture of 2 CS-US interstimulus intervals (ISIs): 200 ms and 1,200 ...
Macias Brandon R - - 2005
The detrimental impact of long duration space flight on physiological systems necessitates the development of exercise countermeasures to protect work capabilities in gravity fields of Earth, Moon and Mars. The respective rates of physiological deconditioning for different organ systems during space flight has been described as a result of data ...
Bharadwaj Shrikant R SR School of Optometry, University of California at Berkeley, CA 94720, - - 2006
Velocity and acceleration characteristics provide valuable information about dynamic control of accommodation. We investigated velocity and acceleration of disaccommodation (near-far focusing) from three starting positions. Peak velocity and peak acceleration of disaccommodation increased with the proximity of starting position however for a given starting position they were invariant of response ...
Wraight William M - - 2005
Chest drains are normally inserted in the fifth intercostal space in the mid-axillary line. The classical technique for chest drain insertion involves locating the drain in an interspace just superior to the inferior rib, so as to avoid the neurovascular bundle. While teaching thoracic wall anatomy on cadavers, considerable variation ...
Iwase Satoshi - - 2005
To test the effectiveness of centrifuge-induced artificial gravity with ergometric exercise, 12 healthy young men (20.7 +/- 1.9 yr) were exposed to simulated microgravity for 14 days of -6 degrees head-down bedrest. Half the subjects were randomly selected and loaded 1.2 G artificial gravity with 60 W (four out of ...
Muto Ayako - - 2005
We report on three patients with xeroderma pigmentosum group A (XPA) who showed laryngeal stridor in their 20s. The stridor appeared on feeding and emotional excitation, was exaggerated during respiratory infection and was life-threatening on some occasions. Adduction of the vocal cords during inspiration, observed by laryngoscopy, confirmed laryngeal dystonia ...
Moore Steven T - - 2005
Four payload crewmembers were exposed to sustained linear acceleration in a centrifuge during the Neurolab (STS-90) flight. In contrast to previous studies, otolith-ocular reflexes were preserved during and after flight. This raised the possibility that artificial gravity may have acted as a countermeasure to the deconditioning of otolith-ocular reflexes. None ...
D'Andrea Susan E - - 2005
BACKGROUND: Exercise is a promising countermeasure to the physiological deconditioning experienced in microgravity, but has not proven effective in eliminating the ongoing loss of bone mineral, most likely due to the lack of high-impact forces and loading rates during in-flight activity. We wanted to determine lower-extremity response to high-impact jumping ...
Stemple Joseph C - - 2005
Therapy approaches designed to improve the disordered voice may be equally effective when used to enhance the normal voice. A holistic approach to voice therapy is based on a continuum of voice wellness from the disordered voice to the elite voice of the healthy performer. Individuals take charge of the ...
Johansen Espen Borgå - - 2005
Attention-deficit/hyperactivity disorder (ADHD), affecting 3-5% of grade-school children, is a behavioral disorder characterized by developmentally inappropriate levels of inattention, hyperactivity, and impulsivity. It has been suggested that the symptoms are caused by altered reinforcement and extinction processes, behaviorally described as an abnormally short and steep delay-of-reinforcement gradient in ADHD. The ...
Huey Raymond B - - 2005
A catastrophic extinction occurred at the end of the Permian Period. However, baseline extinction rates appear to have been elevated even before the final catastrophe, suggesting sustained environmental degradation. For terrestrial vertebrates during the Late Permian, the combination of a drop in atmospheric oxygen plus climate warming would have induced ...
Makiyama Kiyoshi - - 2005
OBJECTIVE: To determine the role of the adjustment of expiratory effort in the control of vocal intensity. STUDY DESIGN: An intensity-loading test was performed by using the airway interruption method. Three groups of subjects were used: a control group thought to resemble normal vocal fold closure, a group of patients ...
Prodi Nicola - - 2005
In the framework of opera house acoustics, the term "balance" refers to the acoustical competition between the singer on the stage and the orchestra in the pit. The mechanism allowing the operatic singers to be heard over the orchestra has to do with their skill in enhancing the vocal emission ...
Remage-Healey Luke - - 2005
It is well known that plasma androgens are rapidly released in response to aggressive or sexual stimuli in a broad array of vertebrates. However, experimental work on behavioral functions of rapid androgen elevation is rare. A combination of field-based behavioral experiments and lab-based neuroendocrinological approaches is beginning to show how ...
North Stephen T - - 2005
In Study 1, we examined the independent effects of reinforcer consumption during sessions and meal consumption prior to sessions on performance maintained by food reinforcement. Nine individuals with developmental disabilities participated. On alternate days, a preferred edible item was delivered during (a) seven sessions conducted before lunch (repeated-reinforcement condition) versus ...
Bele Irene Velsvik - - 2005
It is common practice in vocal training to make use of vocal exercise techniques that involve partial occlusion of the vocal tract. Various techniques are used; some of them form an occlusion within the front part of the oral cavity or at the lips. Another vocal exercise technique involves lengthening ...
Strollo F - - 2005
Extraterrestrial exploration has gone on for decades before reversible testicular failure was shown to be a consequence of space flight in humans and animals at the end of the XXth century. This phenomenon was initially thought to depend on the psycho-physical stress expected to derive from a decidedly unusual environment, ...
Farnè Alessandro - - 2005
Recent findings from neurophysiology, neuropsychology and psychology have shown that peri-personal space is represented through an integrated multisensory processing. In humans, the interaction between peri-personal space representation and action execution can be revealed through the use of tools that, by extending the reachable space, modify the strength of visual-tactile extinction. ...
Thompson Rachel H - - 2005
A demonstration of the effects of reinforcement requires comparison of response rates in the presence of a contingency with those in another condition that controls for the influence of extraneous variables. We describe several control conditions that have been used in evaluating the effects of positive and negative reinforcement. The ...
Doughty Adam H - - 2004
Reinstatement refers to the recovery of previously extinguished responding by the response-independent delivery of a stimulus that was a reinforcer in training. Two experiments were conducted to examine relative reinstatement following the training of differential preextinction response rates, either with equal (Experiment 1) or unequal (Experiment 2) preextinction reinforcement rates. ...
Robleto Karla - - 2004
Rabbits (Oryctolagus cuniculus) were presented with 7 daily sessions of tone-alone training after conditioning. Before the beginning of each of the first 4 extinction sessions, an artificial tear solution or tetracaine hydrochloride was administered to the cornea of rabbits in the control group (n = 6) and experimental group (n ...
Lind Johan - - 2004
Migrating birds must accumulate fuel during their journeys and this fuel load should incur an increased risk of predation. Migratory fuelling should increase individual mass-dependent predation risk for two reasons. First, acquisition costs are connected to the increased time a bird must spend foraging to accumulate the fuel loads and ...
Laukkanen Anne-Maria - - 2004
Twenty-four females (mean age 38 years) with varying amounts of vocal training read aloud from a book for 45 min (70 dB at 40 cm distance). Symptoms of the throat and voice were ascertained with a questionnaire before, during and after the test. Fundamental frequency (F(0)) and sound pressure level ...
Riede Tobias - - 2004
Ring doves vocalize with their beaks and nostrils closed, exhaling into inflatable chambers in the head and neck region. The source sound produced at the syrinx contains a fundamental frequency with prominent second and third harmonic overtones, but these harmonics are filtered out of the emitted signal. We show by ...
Hirano Shigeru - - 2004
Vocal fold scarring remains a therapeutic challenge. Hepatocyte growth factor (HGF) has strong antifibrotic activity and has proved to have therapeutic potential in restoration of scar tissues such as liver cirrhosis and lung fibrosis. The present study aimed to clarify the effects of HGF injection into scarred vocal folds in ...
Hambly C - - 2004
The effect of experimentally increased wing loading on the energy cost of flight was examined in cockatiels Nyphicus hollandicus. Five individuals were flown for periods of approximately 2 min, while carrying additional payload mass amounting to between 5 and 20% of unloaded body mass. The energy cost of flight was ...
Carding P N - - 2004
This study aimed to evaluate the reliability and sensitivity to change of three commonly used acoustic parameters as measured by the Multi-Dimensional Voice Programme (MDVP); jitter, shimmer and noise-to-harmonic ratio. A total of 231 subjects' voices were recorded and analysed. The sample comprised 145 dysphonic patients who received intervention (surgery ...
Hambly C - - 2004
Asymmetry is a difference in the sizes of bilaterally paired structures. Wing asymmetry may have an effect on the kinematics of flight, with knock-on effects for the energetic cost of flying. In this study the 13C-labelled bicarbonate technique was used to measure the energy expended during the flight of zebra ...
Schleich Cristian Eric - - 2004
Theoretical signaling models predict that to be honest, begging vocalizations must be costly. To test this hypothesis, oxygen consumption was measured during resting and begging (i.e., vocalizing) activities in pups of the subterranean rodent Ctenomys talarum by means of open-flow respirometry. No statistical differences in individual oxygen consumption between resting ...
Bridge Eli S - - 2004
Large and medium-sized alcids have a very intense wing molt wherein many flight feathers are shed in rapid succession and wing surface area is reduced by as much as 40%. Although these birds are rendered flightless during wing molt, they must still use their wings to propel themselves underwater. A ...
Fallon K E - - 2004
This case concerns an elite road cyclist who complained of occasional dyspnoea and inspiratory difficulty during intense exercise. Clinical examination was normal and the final diagnosis was vocal cord dysfunction, a paradoxical closure of the vocal cords during inspiration which is highly associated with inspiratory stridor at high rates of ...
Moors Hilary B - - 2004
Many vocalizations produced by Weddell seals (Leptonychotes weddellii) are made up of repeated individual distinct sounds (elements). Patterning of multiple element calls was examined during the breeding season at Casey and Davis, Antarctica. Element and interval durations were measured from 405 calls all > 3 elements in length. The duration ...
Kozlovskaya Inessa B - - 2004
The system of countermeasures used by Russian cosmonauts in space flights on board of International Space Station (ISS) was based on the developed and tested in flights on board of Russian space stations. It included as primary components: physical methods aimed to maintain the distribution of fluids at levels close ...
Gottlieb Daniel A - - 2004
Contemporary time accumulation models make the unique prediction that acquisition of a conditioned response will be equally rapid with partial and continuous reinforcement, if the time between conditioned stimuli is held constant. To investigate this, acquisition of conditioned responding was examined in pigeon autoshaping under conditions of 100% and 25% ...
Blomeley Frances J - - 2004
Four rats received training on a mixed FI 30-s FI 150-s schedule, where the different FI values were associated with different levers. During baseline, the reinforcer was a 30% concentration of condensed milk. During subsequent testing sessions, the reinforcer concentration was varied within sessions over values of 10, 30, 50, ...
Caiani E G - - 2004
Aim of the study was to evaluate by transthoracic Doppler the alterations in mitral inflow velocity pattern caused by acute changes in loading conditions occurring during parabolic flights. Each parabola included normogravity (1 Gz, 1 min), mild hypergravity (1.8 Gz, 20 sec), microgravity (0 Gz, 24 sec) and mild hypergravity ...
Popov D V - - 2004
The efficacy of countermeasure exercise for diminishing disturbances induced by microgravity in motor system and its visceral supply during different stages of long-duration flight was evaluated. The results of both bicycle and locomotor testing indicate that physical fitness of cosmonaut does not become worse in the course of the long-duration ...
Reilly Nicole - - 2004
We sought to profile the voice acoustical correlates of simulated, or feigned depression by neurologically and psychiatrically healthy control subjects. We also sought to identify the voice acoustical correlates of feigned sleepiness for these same subjects. Twenty-two participants were asked to speak freely about a cartoon, to count from 1 ...
Tafforin Carole - - 2004
This new ethological study focuses on the co-adaptation of the crew's spatial behavior to social isolation in a polar base thus simulating long-term living and working of a space team. The method consisted in drawing the subjects' position (n=13) on an observation map at the midday and evening meals at ...
Tautz Juergen - - 2004
Recent studies have shown that honeybees flying through short, narrow tunnels with visually textured walls perform waggle dances that indicate a much greater flight distance than that actually flown. These studies suggest that the bee's "odometer" is driven by the optic flow (image motion) that is experienced during flight. One ...
Brownlee Donald E - - 2004
Images taken by the Stardust mission during its flyby of 81P/Wild 2 show the comet to be a 5-kilometer oblate body covered with remarkable topographic features, including unusual circular features that appear to be impact craters. The presence of high-angle slopes shows that the surface is cohesive and self-supporting. The ...
Suthers Roderick A - - 2004
Vocal signals play a very important role in the life of both birds and echolocating bats, but these two unrelated groups of flying vertebrates have very different vocal systems. They nevertheless must solve many of the same problems in producing sound. This brief review examines avian and microchiropteran motor mechanisms ...
Blaber Andrew P - - 2004
Upon return from space many astronauts experience symptoms of orthostatic intolerance. Research has implicated altered autonomic cardiovascular regulation due to spaceflight with further evidence to suggest that there might be pre-flight autonomic indicators of post-flight orthostatic intolerance. We used heart rate variability (HRV) to determine whether autonomic regulation of the ...
Nelson Emily S - - 2004
Experiments are sent to space laboratories in order to take advantage of the low-gravity environment. However, it is crucial to appreciate the distinction between the real microgravity environment and "weightlessness" or "simulated microgravity". The microgravity in space laboratories may be of much smaller magnitude than the gravitational acceleration on earth. ...
Smith Suzanne D - - 2004
INTRODUCTION: Human vibration exposure data relative to military tactical and strategic aircraft operations are required for assessing the potential health risks and performance consequences when using helmet-mounted equipment. The objective of this study was to characterize cockpit seat and pilot helmet vibration in a jet aircraft during aircraft carrier flight ...
Roberts Stephen P - - 2004
We assessed the energetic and aerodynamic limits of hovering flight in the carpenter bee Xylocopa varipuncta. Using normoxic, variable-density mixtures of O(2), N(2) and He, we were able to elicit maximal hovering performance and aerodynamic failure in the majority of bees sampled. Bees were not isometric regarding thorax mass and ...
Greenleaf John E - - 2004
Air passenger miles will likely double by year 2020. The altered and restrictive environment in an airliner cabin can influence haematological homeostasis in passengers and crew. Flight-related deep venous thromboemboli (DVT) have been associated with at least 577 deaths on 42 of 120 airlines from 1977 to 1984 (25 deaths/million ...
Albery William B - - 2004
BACKGROUND: Modern, thrust-vectored jet aircraft have the capability of developing multi-axis accelerations, especially during the performance of "supermaneuvers." These "agile" aircraft are capable of unconventional flight. The human consequences of this agile flight environment are unknown. METHODS: This multi-axis acceleration environment was studied on the Dynamic Environment Simulator gimbaled centrifuge. ...
Shull Richard L - - 2004
By nose poking a lighted key, rats obtained food pellets on either a variable-interval schedule of reinforcement or a schedule that required an average of four additional responses after the end of tile variable-interval component (a tandem variable-interval variable-ratio 4 schedule). With both schedule types, the mean variable interval was ...
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