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off vertical axis rotation

O Kuldavletova, S Marie, P Denise, H Normand
NEW FINDINGS: What is the central question of this study? It is known that respiration is affected by graviceptors, but it remains unclear to what extent labyrinthine and non-labyrinthine graviceptors are involved in this process. What is the main finding and its importance? Our results suggest that the respiration modulation is not a result of a simple reflex arc, but that it involves a higher integration of different types of receptors with variable contribution of either type of graviceptors among subjects...
May 8, 2018: Experimental Physiology
Francesca Di Lillo, Giovanni Mettivier, Roberta Castriconi, Antonio Sarno, Andrew W Stevenson, Chris J Hall, Daniel Häusermann, Paolo Russo
The principle of rotational summation of the absorbed dose for breast cancer treatment with orthovoltage X-ray beams was proposed by J. Boone in 2012. Here, use of X-ray synchrotron radiation for image guided external beam rotational radiotherapy treatment of breast cancer is proposed. Tumor irradiation occurs with the patient in the prone position hosted on a rotating bed, with her breast hanging from a hole in the bed, which rotates around a vertical axis passing through the tumor site. Horizontal collimation of the X-ray beam provides for whole breast or partial breast irradiation, while vertical translation of the bed and successive rotations allow for irradiation of the full tumor volume, with dose rates which permit also hypofractionated treatments...
May 1, 2018: Journal of Synchrotron Radiation
Gilles Clément, Millard F Reschke
BACKGROUND: It has been proposed that individual susceptibility to motion sickness is related to the vestibulo-ocular reflex (VOR) through the activation of the velocity storage mechanism. OBJECTIVE: We investigated whether motion sickness level was related to the gain and phase of the VOR. METHODS: VOR gain and phase were measured in 214 subjects while they rotated in yaw at 0.01 Hz, 0.02 Hz, 0.04 Hz, 0.08 Hz, and 0.16 Hz in darkness, and results were compared to the severity of symptoms the subjects experienced during subsequent tests to provoke motion sickness...
April 18, 2018: Journal of Vestibular Research: Equilibrium & Orientation
Jeong-Yoon Choi, Stefan Glasauer, Ji Hyun Kim, David S Zee, Ji-Soo Kim
Here we characterize persistent apogeotropic type of central positional nystagmus, and compare it with the apogeotropic nystagmus of benign paroxysmal positional vertigo involving the lateral canal. Nystagmus was recorded in 27 patients with apogeotropic type of central positional nystagmus (22 with unilateral and five with diffuse cerebellar lesions) and 20 patients with apogeotropic nystagmus of benign paroxysmal positional vertigo. They were tested while sitting, while supine with the head straight back, and in the right and left ear-down positions...
January 24, 2018: Brain: a Journal of Neurology
Sergei B Yakushin, Theodore Raphan, Bernard Cohen
Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic) information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO) and vestibular-pause-saccade (VPS) neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage...
2017: Frontiers in Neurology
Roberto Panichi, Chiara Occhigrossi, Aldo Ferraresi, Mario Faralli, Marco Lucertini, Vito E Pettorossi
BACKGROUND: This paper examines the subjective sense of orientation during asymmetric body rotations in normal subjects. METHODS: Self-motion perception was investigated in 10 healthy individuals during asymmetric whole-body rotation with different head orientations. Both on-vertical axis and off-vertical axis rotations were employed. Subjects tracked a remembered earth-fixed visual target while rotating in the dark for four cycles of asymmetric rotation (two half-sinusoidal cycles of the same amplitude, but of different duration)...
May 1, 2017: Aerospace Medicine and Human Performance
Aasef G Shaikh, David Solomon
Constant velocity rotations in darkness evoke vestibulo-ocular reflex in form of pre- and post-rotational nystagmus under cerebellar supervision. Reorientation of the head with respect to gravity, stimulating otolith and semicircular canal, during post-rotational phase rapidly suppresses the post-rotational nystagmus. We asked if pure otolith stimulation without semicircular canal signal is sufficient for the suppression of post-rotational nystagmus. The experimental paradigm comprised of on-axis rotations in the horizontal plane when the subject was sitting upright, followed by a novel stimulus that combined off-axis centrifugation in the horizontal plane with amplitude matched, yet out-of-phase, on-axis horizontal rotation-double centrifugation...
June 2017: Cerebellum
Samantha B Douglas, Gilles Clément, Pierre Denise, Scott J Wood
Constant velocity Off-Vertical Axis Rotation (OVAR) imposes a continuously varying orientation of the head and body relative to gravity, which generates a modulation of horizontal (conjugate and vergence), vertical, and torsional eye movements. We introduced the head-turn-on-trunk paradigm during OVAR to examine the extent to whether the modulation of these ocular reflexes is mediated by graviceptors in the head, i.e., otoliths, versus other body graviceptors. Ten human subjects were rotated in darkness about their longitudinal axis 20° off-vertical at a constant velocity of 45 and 180°/s, corresponding to 0...
February 8, 2017: Scientific Reports
Yasuhiro Takaki, Mitsuki Nakaoka
Viewing-zone scanning holographic displays can enlarge both the screen size and the viewing zone. However, limitations exist in the screen size enlargement process even if the viewing zone is effectively enlarged. This study proposes a multi-channel viewing-zone scanning holographic display comprising multiple projection systems and a planar scanner to enable the scalable enlargement of the screen size. Each projection system produces an enlarged image of the screen of a MEMS spatial light modulator. The multiple enlarged images produced by the multiple projection systems are seamlessly tiled on the planar scanner...
August 8, 2016: Optics Express
Gilles Clément, Scott J Wood
Two characteristics of otolith-ocular responses - linear vestibulo-ocular reflex and vergence - were examined during constant velocity off-vertical axis rotation (OVAR) in the dark. Sixteen subjects were rotated about their longitudinal axis when tilted 30° relative to the direction of gravity. Rotational velocities were 36 and 288/s corresponding to frequencies of 0.1 and 0.8Hz, respectively. Subjects were asked to imagine stationary targets located at 0.5m, 1m, and 2m in the straight-ahead direction. Binocular eye movements were recorded in the dark using infrared videography...
March 11, 2016: Neuroscience Letters
Masatoshi Akutsu, Akemi Sugita-Kitajima, Koshi Mikami, Izumi Koizuka
OBJECTIVE: We investigated whether adaptive plasticity of the vestibulo-ocular reflex in humans occurs in response to visual-vestibular conflict stimulation during rotation about a 30° incline (off-vertical earth axis rotation, OVAR). METHODS: Subjects were 26 healthy adults (17 males and 9 females), ranging in age from 22 to 33 years (mean: 24.4) with no history of neurotological symptoms. Each testing session consisted of a pre-test, an adaptation period, and a post-test...
August 2016: Auris, Nasus, Larynx
Sophie Bernard, Sylvette Wiener-Vacher, Thierry Van Den Abbeele, Natacha Teissier
BACKGROUND: Congenital cytomegalovirus (CMV) infection is the leading infectious cause of neurologic disabilities and sensorineural hearing loss in children. Sensorineural hearing loss prevalence in CMV suggests a viral tropism for the inner ear. Vestibular disorders induced by CMV infection are underestimated. This is the largest and most thorough study to assess the incidence of vestibular disorders and their correlation with hearing thresholds in children with CMV. METHODS: This retrospective study assessed a cohort of 52 children with congenital CMV infection and sensorineural impairment who received a complete hearing and vestibular assessment...
October 2015: Pediatrics
E I Matsnev, E E Sigaleva
The objective of the present study was the clinical and neurophysiological analysis of the observations of a 42 year-old female patient suffering from benign paroxysmalpositional dizziness (BPPD) associated with the lesion of the posterior semicircular canal. The dynamic evaluation of the utricular function was performed during eccentric rotation of the patient in the vestibulometric chair at a speed of 300 degrees. The chair together with the patients was atomatically displaced during the rotation 3.5--4.0 cm to the right or left off the vertical axis, and the error in subjective perception of the deviation from the vertical was estimated...
2015: Vestnik Otorinolaringologii
Jelte E Bos
BACKGROUND: Motion sickness may reduce passenger comfort and crew performance. Countermeasures are dominated by medication with specific and often undesirable side effects. OBJECTIVE: To shown that sickness due to motion can be reduced by adding an inherent non-sickening vibration and by mental distraction. METHODS: Eighteen blindfolded subjects were exposed to 20 minutes of off-vertical axis rotation (OVAR). Vibration was added by means of a head rest...
2015: Journal of Vestibular Research: Equilibrium & Orientation
Patrick A Armstrong, Scott J Wood, Naoki Shimizu, Kael Kuster, Adrian Perachio, Tomoko Makishima
Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: (1) horizontal angular vestibulo-ocular reflex (hVOR) to evaluate semicircular canal function and (2) otolith-ocular reflex (OOR) to evaluate otolith organ function and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo off-vertical axis rotation to induce an otolith-only stimulus using a custom-made centrifuge...
June 2015: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Anabela Maia, Alex P Sheltzer, Eric D Tytell
In their natural environment, fish must swim stably through unsteady flows and vortices, including vertical vortices, typically shed by posts in a flow, horizontal cross-flow vortices, often produced by a step or a waterfall in a stream, and streamwise vortices, where the axis of rotation is aligned with the direction of the flow. Streamwise vortices are commonly shed by bluff bodies in streams and by ships' propellers and axial turbines, but we know little about their effects on fish. Here, we describe how bluegill sunfish use more energy and are destabilized more often in flow with strong streamwise vorticity...
March 2015: Journal of Experimental Biology
N Shimizu, S Wood, K Kushiro, S Yanai, A Perachio, T Makishima
The central vestibular system plays an important role in higher neural functions such as self-motion perception and spatial orientation. Its ability to store head angular velocity is called velocity storage mechanism (VSM), which has been thoroughly investigated across a wide range of species. However, little is known about the mouse VSM, because the mouse lacks typical ocular responses such as optokinetic after nystagmus or a dominant time constant of vestibulo-ocular reflex for which the VSM is critical. Experiments were conducted to examine the otolith-driven eye movements related to the VSM and verify its characteristics in mice...
January 29, 2015: Neuroscience
Kevin Luttrell, Michael Beltran, Cory A Collinge
OBJECTIVE: To identify the current implant and diagnostic imaging preferences among orthopaedic trauma experts for the treatment of high-energy vertical femoral neck fractures in young adult patients. DESIGN: Web-based survey. SETTING: Not available. PARTICIPANTS: Active members of the OTA. METHODS: A cross-sectional expert opinion survey was administered to the active members of the OTA to determine their preferences for implant use and imaging in the surgical treatment of a vertical femoral neck fracture in a young adult patient (e...
September 2014: Journal of Orthopaedic Trauma
Kevin Luttrell, Michael Beltran, Cory Collinge
OBJECTIVE: To identify the current implant and diagnostic imaging preferences among orthopedic trauma experts for the treatment of high-energy vertical femoral neck fractures in young adult patients. DESIGN: Web-based survey SETTING:: N/A PARTICIPANTS:: Active members of the Orthopaedic Trauma Association (OTA) METHODS:: A cross sectional expert opinion survey was administered to active members of the OTA to determine their preferences for implant use and imaging in the surgical treatment of a vertical femoral neck fracture in a young adult patient (e...
April 1, 2014: Journal of Orthopaedic Trauma
A C Paillard, M Lamôré, O Etard, J-L Millot, L Jacquot, P Denise, G Quarck
The aim of this study was to evaluate the relationship between olfaction and motion sickness. A sample of 18 participants was recruited and submitted to three sessions of nauseogenic stimulations: off vertical axis rotation (OVAR), performed under conditions of olfactory stimulation with limonene (pleasant odor), petrol (unpleasant odor) or distilled water (as a control). Motion sickness was assessed before, during and after each OVAR session. In addition, participants were asked to evaluate the intensity and hedonic valence of four odors (geraniol, limonene, butanol, petrol) as well as distilled water (as a control) before and after each OVAR session...
April 30, 2014: Neuroscience Letters
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