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sinusoidal rotation

Manbir Nagra, Bernard Gilmartin, Nicola S Logan, Stephen J Anderson
SIGNIFICANCE: Poor peripheral visual acuity in myopia may reflect, in part, photoreceptor misalignment with the exit pupil of the eye. We speculate that if such misalignment causes sufficient visual deprivation and/or disrupts retinal feedback processes, it may influence eye growth itself. PURPOSE: It is known that myopic eyes have a reduced peripheral resolution acuity relative to emmetropic eyes, though it remains unclear how mechanical stretching of the retina in myopia impacts on peripheral visual performance...
March 16, 2018: Optometry and Vision Science: Official Publication of the American Academy of Optometry
Mohd Suhail Rizvi, Alexander Farutin, Chaouqi Misbah
The self-propelled microswimmers have recently attracted considerable attention as model systems for biological cell migration as well as artificial micromachines. A simple and well-studied microswimmer model consists of three identical spherical beads joined by two springs in a linear fashion with active oscillatory forces being applied on the beads to generate self-propulsion. We have extended this linear microswimmer configuration to a triangular geometry where the three beads are connected by three identical springs in an equilateral triangular manner...
February 2018: Physical Review. E
Yoshinobu Shimohigashi, Fujio Araki, Masato Maruyama, Keisuke Yonemura, Yuji Nakaguchi, Yudai Kai, Ryo Toya
In this study, qualities of 4D cone-beam CT (CBCT) images obtained using various gantry rotation speeds (GRSs) for liver stereotactic body radiation therapy (SBRT) with fiducial markers were quantitatively evaluated. Abdominal phantom containing a fiducial marker was moved along a sinusoidal waveform, and 4D-CBCT images were acquired with GRSs of 50-200° min-1 . We obtained the 4D-CBCT projection data from six patients who underwent liver SBRT and generated 4D-CBCT images at GRSs of 67-200° min-1 , by varying the number of projection data points...
January 2018: Physica Medica: PM
Dianzhong Chen, Xiaowei Liu, Haifeng Zhang, Hai Li, Rui Weng, Ling Li, Wanting Rong, Zhongzhao Zhang
Stable rotor levitation is a challenge for rotational gyroscopes (magnetically suspended gyroscopes (MSG) and electrostatically suspended gyroscopes (ESG)) with a ring- or disk-shaped rotor, which restricts further improvement of gyroscope performance. In addition, complicated pick-up circuits and feedback control electronics propose high requirement on fabrication technology. In the proposed gyroscope, a ball-disk shaped rotor is supported by a water-film bearing, formed by centrifugal force to deionized water at the cavity of the lower supporting pillar...
January 31, 2018: Sensors
Pengyu Ren, Bowen Li, Shiyao Dong, Lin Chen, Yuelin Zhang
Although many mathematical methods were used to analyze the neural activity under sinusoidal stimulation within linear response range in vestibular system, the reliabilities of these methods are still not reported, especially in nonlinear response range. Here we chose nonlinear least-squares algorithm (NLSA) with sinusoidal model to analyze the neural response of semicircular canal neurons (SCNs) during sinusoidal rotational stimulation (SRS) over a nonlinear response range. Our aim was to acquire a reliable mathematical method for data analysis under SRS in vestibular system...
2018: PloS One
P L Read, X Morice-Atkinson, E J Allen, A A Castrejón-Pita
A series of laboratory experiments in a thermally driven, rotating fluid annulus are presented that investigate the onset and characteristics of phase synchronization and frequency entrainment between the intrinsic, chaotic, oscillatory amplitude modulation of travelling baroclinic waves and a periodic modulation of the (axisymmetric) thermal boundary conditions, subject to time-dependent coupling. The time-dependence is in the form of a prescribed duty cycle in which the periodic forcing of the boundary conditions is applied for only a fraction δ of each oscillation...
December 2017: Chaos
Stuart W Mackenzie, Raymond F Reynolds
BACKGROUND: Eye movements evoked by electrical vestibular stimulation (EVS) offer potential for diagnosing vestibular dysfunction. However, ocular recording techniques are often too invasive or impractical for routine clinical use. Furthermore, the kinematic nature of the EVS signal is not fully understood in terms of movement sensations. NEW METHOD: We apply sinusoidal EVS stimuli varying from 0.05 to 20Hz, and record the eye in darkness using an infrared camera...
January 15, 2018: Journal of Neuroscience Methods
David H Peterzell, Ignacio Serrano-Pedraza, Michael Widdall, Jenny C A Read
Threshold functions for sinusoidal depth corrugations typically reach their minimum (highest sensitivity) at spatial frequencies of 0.2-0.4 cycles/degree (cpd), with lower thresholds for horizontal than vertical corrugations at low spatial frequencies. To elucidate spatial frequency and orientation tuning of stereoscopic mechanisms, we measured the disparity sensitivity functions, and used factor analytic techniques to estimate the existence of independent underlying stereo channels. The data set (N=30 individuals) was for horizontal and vertical corrugations of spatial frequencies ranging from 0...
November 15, 2017: Vision Research
Xin Wang, Ke Chen, Linbo Liu, Nan Xiang, Zhonghua Ni
Nanowire assembly based on dielectrophoresis (DEP) could be a useful and efficient tool for fabricating nanowire-based devices. Although there have been extensive reports on the DEP nanowire assembly, the new approaches that make DEP more facile and affordable are still desirable. Herein, we present an approach using the reusable electrodes to assemble silver nanowires onto a removable, independent polyethylene terephthalate (PET) film. The PET film is placed on the reusable electrodes, and a sinusoidal AC voltage is applied to the electrodes to induce DEP force for nanowire assembly upon the flexible film...
January 12, 2018: Nanotechnology
Christian Liebsch, Julia Zimmermann, Nicolas Graf, Christoph Schilling, Hans-Joachim Wilke, Annette Kienle
Biomechanical in vitro tests analysing screw loosening often include high standard deviations caused by high variabilities in bone mineral density and pedicle geometry, whereas standardized mechanical models made of PU foam often do not integrate anatomical or physiological boundary conditions. The purpose of this study was to develop a most realistic mechanical model for the standardized and reproducible testing of pedicle screws regarding the resistance against screw loosening and the holding force as well as to validate this model by in vitro experiments...
October 25, 2017: Journal of the Mechanical Behavior of Biomedical Materials
Michael Strupp, Ji-Soo Kim, Toshihisa Murofushi, Dominik Straumann, Joanna C Jen, Sally M Rosengren, Charles C Della Santina, Herman Kingma
This paper describes the diagnostic criteria for bilateral vestibulopathy (BVP) by the Classification Committee of the Bárány Society. The diagnosis of BVP is based on the patient history, bedside examination and laboratory evaluation. Bilateral vestibulopathy is a chronic vestibular syndrome which is characterized by unsteadiness when walking or standing, which worsen in darkness and/or on uneven ground, or during head motion. Additionally, patients may describe head or body movement-induced blurred vision or oscillopsia...
2017: Journal of Vestibular Research: Equilibrium & Orientation
Jiawen Ma, Tian Wang, Vedran Lovric, Kenneth A Johnson, William R Walsh
BACKGROUND: The physis is the weakest component of immature long bones, and physeal fractures constitute about 30% of fractures in growing dogs. Fractures of the proximal humeral physis typically have a Salter Harris type I or II configuration. These fractures require accurate reduction and adequate stabilization to allow for any potential continued longitudinal bone growth, in conjunction with physeal fracture healing. Conventional internal fixation of these fractures involves insertion of two parallel Kirschner wires, although other methods described include tension band wiring, Rush pinning, and lag screws...
October 25, 2017: BMC Veterinary Research
Leslie M Theunissen, Nikolaus F Troje
Stabilization of the head in animals with limited capacity to move their eyes is key to maintain a stable image on the retina. In many birds, including pigeons, a prominent example for the important role of head stabilization is the characteristic head-bobbing behavior observed during walking. Multimodal sensory feedback from the eyes, the vestibular system and proprioceptors in body and neck is required to control head stabilization. Here, we trained unrestrained pigeons (Columba livia) to stand on a perch that was sinusoidally moved with a motion platform along all three translational and three rotational degrees of freedom...
2017: Frontiers in Neuroscience
Yunlong Meng, Wei Lin, Chenglin Li, Shih-Chi Chen
We present a new two-snapshot structured light illumination (SLI) reconstruction algorithm for fast image acquisition. The new algorithm, which only requires two mutually π phase-shifted raw structured images, is implemented on a custom-built temporal focusing fluorescence microscope (TFFM) to enhance its axial resolution via a digital micromirror device (DMD). First, the orientation of the modulated sinusoidal fringe patterns is automatically identified via spatial frequency vector detection. Subsequently, the modulated in-focal-plane images are obtained via rotation and subtraction...
September 18, 2017: Optics Express
Minbum Kim, Kyu-Sung Kim
HYPOTHESIS: A vasopressin-induced endoymphatic hydrops model can represent an acute vertiginous attack in Menière's disease (MD). BACKGROUND: Previous animal models are not appropriate to evaluate the efficacy of new treatments for hydrops because they cannot represent an acute attack of MD. Recently, a new dynamic model was introduced for acute hydrops exacerbation using the vasopressin type 2 receptor agonist, desmopressin (1-deamino-8-D-Arginine vasopressin, VP); however, resulting changes in vestibular function have not been investigated...
December 2017: Otology & Neurotology
Sayaka Yamao, Chota Matsumoto, Hiroki Nomoto, Takuya Numata, Mariko Eura, Marika Yamashita, Shigeki Hashimoto, Sachiko Okuyama, Shinji Kimura, Kenzo Yamanaka, Yasutaka Chiba, Makoto Aihara, Yoshikazu Shimomura
PURPOSE: A newly developed head-mounted perimeter termed "imo" enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject's head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results...
2017: PloS One
Joanna Rupa-Matysek, Lidia Gil, Ewelina Wojtasińska, Zuzanna Kanduła, Adam Nowicki, Magdalena Matuszak, Mieczysław Komarnicki
Hepatic sinusoidal obstruction syndrome (previously named veno-occlusive disease, SOS/VOD) is a serious complication of allogeneic stem cell transplantation (HSCT). Early identification of patients at risk of SOS/VOD may possibly improve the outcome and reduce mortality. Rotation thromboelastometry (ROTEM) is global assay allowing for the precise assessment of both bleeding and thrombotic conditions, however, its usefulness in patients undergoing HSCT for acute leukaemia has not been studied. We evaluated the thromboelastometry parameters in patients undergoing allogeneic HSCT for acute leukaemia to identify candidate biomarkers of SOS/VOD occurrence...
August 29, 2017: Oncotarget
U H Patel, Chintan Jotaniya, D A Shah, Bhavesh Socha
In the title mol-ecule, C12H13FN2O3, the central pyrrole ring makes a dihedral angle of 9.2 (3)° with the eth-oxy carbonyl moiety whereas the fluoro-phenyl ring is rotated by 67.6 (2)° from the pyrrole ring. Supra-molecular aggregation is due to off-centric π-π stacking inter-actions involving screw-related pairs of mol-ecules, which are further connected by N-H⋯O and C-H⋯O inter-actions, forming a sinusoidal pattern along the [001] direction on the bc plane. Three-dimensional Hirshfeld surface analysis and two-dimensional fingerprint plots confirm the contributions of these inter-actions...
September 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
Matthias Knobe, Simon Altgassen, Klaus-Jürgen Maier, Gertraud Gradl-Dietsch, Chris Kaczmarek, Sven Nebelung, Kajetan Klos, Bong-Sung Kim, Boyko Gueorguiev, Klemens Horst, Benjamin Buecking
OBJECTIVES: To reduce mechanical complications after osteosynthesis of femoral neck fractures, improved fixation techniques have been developed including blade or screw-anchor devices. This biomechanical study compares different fixation systems used for treatment of unstable femoral neck fractures with evaluation of failure mode, load to failure, stiffness, femoral head rotation, femoral neck shortening and femoral head migration. METHODS: Standardized Pauwels type 3 fractures (AO/OTA 31-B2) with comminution were created in 18 biomechanical sawbones using a custom-made sawguide...
February 2018: International Orthopaedics
Patrick P Hübner, Serajul I Khan, David M Lasker, Americo A Migliaccio
Core body temperature has been shown to affect vestibular end-organ and nerve afferents so that their resting discharge rate and sensitivity increase with temperature. Our aim was to determine whether these changes observed in extracellular nerve recordings of anaesthetized C57BL/6 mice corresponded to changes in the behavioural vestibulo-ocular reflex (VOR) of alert mice. The VOR drives eye rotations to keep images stable on the retina during head movements. We measured the VOR gain (eye velocity/head velocity) and phase (delay between vestibular stimulus and response) during whole-body sinusoidal rotations ranging 0...
December 2017: Journal of the Association for Research in Otolaryngology: JARO
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