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Shigeru Makita - One of the best experts on this subject based on the ideXlab platform.
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Test-retest reliability of and age-related changes in the subjective postural vertical on the Diagonal Plane in healthy subjects
Attention Perception & Psychophysics, 2019Co-Authors: Kazuhiro Fukata, Kazu Amimoto, Daisuke Sekine, Yuka Ikarashi, Yuji Fujino, Masahide Inoue, Mamiko Inoue, Shunichi Ishihara, Hidetoshi Takahashi, Shigeru MakitaAbstract:The subjective postural vertical (SPV) reflects gravity perception when the eyes are closed. Changes in the SPV on both the frontal and sagittal Planes occur in response to neurological disorders and aging; however, these changes on the Diagonal Plane are unclear. Here we examined test–retest reliability (n=16) of and age-related changes (n=38) in the SPV on the Diagonal Plane. Subjects sat on an electrical vertical board (EVB), which was used to measure the SPV on the Diagonal Plane. An experimenter controlled and moved the EVB seat at a constant speed on the Diagonal Plane and measured the seat’s tilt using a digital inclinometer when subjects verbally reported that they had reached a true vertical position. Measurement was performed for eight trials, and the mean (tilt direction) and standard deviation (variability) were calculated. To determine test–retest reliability, the same experimenter repeatedly measured the SPV 1 week later. To assess age-related changes, tilt direction and variability were compared between the young (n=20) and elderly (n=18) groups. Test–retest reliability on the right and left Diagonal Planes was 0.61 or more. Moreover, tilt direction on the right Diagonal Plane – but not on the left Diagonal Plane – indicated a significant Diagonally backward deviation in the elderly group compared with that in the young group. Variability was significantly higher in the elderly group on both Planes. SPV measurement on the Diagonal Plane was indicated, and age-related changes were identified. Thus, future studies should assess the potential clinical applications of SPV in neurological disorders.
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Analysis of the subjective postural vertical on Diagonal Plane in elderly subjects and left hemiparetic patients after stroke
Annals of Physical and Rehabilitation Medicine, 2018Co-Authors: Daisuke Sekine, Kazuhiro Fukata, Kazu Amimoto, Yuji Fujino, Mamiko Inoue, Hidetoshi Takahashi, Yosuke Takahashi, Shigeru MakitaAbstract:Introduction/Background The subjective postural vertical (SPV) in healthy subjects is robustly maintained by integrating somatosensory and vestibular information, and extremely correct on frontal and sagittal Plane. It is well-known that brain injury patients indicate disturbance of SPV on frontal or sagittal Plane. On the other hand, stroke patients frequently fall paretic side and backward, but SPV on Diagonal Plane in normal subjects and stroke patients is unclear. The purpose of present study was to clarify the difference of SPV on Diagonal Plane between elderly subjects and stroke patients. Material and method The subjects comprised 14 elderly subjects (control group) and 10 left hemiparetic patients (LHP group). All subjects provided their written informed consent to take part in the study. SPV was measured using an electrical vertical board (EVB). The subjects sat on the EVB and were moved in the opposite direction from the left-backward or right-forward. The tilt of the seat when the subject feels and judges vertical position was recorded with a digital inclinometer. The mean (tilt direction) and standard deviation (variability) of eight trials were calculated. A true vertical position was considered 0°, Diagonally backward and Diagonally forward was treated as negative and positive, respectively. The values of SPV were compared between groups using the unpaired t-test (P Results There was no difference between control group (66.8 ± 9.2 years [mean ± SD]) and LHP groups (67.5 ± 10.8 years) in age. In tilt direction, LHP group (−2.5 ± 0.7°) demonstrated significant tilt backward to the left than control group (−1.3 ± 1.4°). Variability was significantly higher in LHP (5.4 ± 2.0°) than control (2.5 ± 0.9°). Conclusion In stroke patients, tilt direction deviated to the Diagonally backward and the judgement of verticality was unstable. These results suggest a possibility to explain the tilt of sitting posture and the difficulty of transfer movement in stroke patients.
Katepalli R. Sreenivasan - One of the best experts on this subject based on the ideXlab platform.
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Reorientations of the large-scale flow in turbulent convection in a cube.
Physical Review E, 2017Co-Authors: Najmeh Foroozani, Joseph Niemela, Vincenzo Armenio, Katepalli R. SreenivasanAbstract:Large-eddy simulations of turbulent Rayleigh-Benard convection were conducted for a fluid of Prandtl number Pr=0.7 confined in a cube, for Rayleigh numbers of 10^{6} and 10^{8}. The model solves the unsteady Navier-Stokes equations under the Boussinesq approximation, using a dynamic Smagorinsky model with a Lagrangian averaging technique for the subgrid terms. Under fully developed conditions the flow topology is characterized by a large-scale circulation (LSC) developing in a Plane containing one of the Diagonals of the cell, while two counter-rotating vortices consequently develop in the other Diagonal Plane, resulting in a strong inflow at the horizontal midPlane. This flow structure is not static, with the LSC undergoing nonperiodic reorientations, or switching, between the two Diagonal Planes; hence, we supplement the observations of the three-dimensional time-averaged flow structures with single point measurements (time series) to shed light on the dynamics of the reorientations. For all observations, this switching results from a lateral rotation of the LSC in which some finite time spent in a transient state where the large-scale circulation is parallel to one set of side walls; there are, importantly, no observations consistent with so-called cessations of the LSC, in which it decays and then reforms in another Plane without such a rotation. The average switching rate for the LSC is in excellent agreement with the results of Bai et al. [K. Bai, D. Ji, and E. Brown, Phys. Rev. E 93, 023117 (2016)PLEEE81539-375510.1103/PhysRevE.93.023117].
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Reorientations of the large-scale flow in turbulent convection in a cube.
Physical review. E, 2017Co-Authors: Najmeh Foroozani, Vincenzo Armenio, J J Niemela, Katepalli R. SreenivasanAbstract:Large-eddy simulations of turbulent Rayleigh-Bénard convection were conducted for a fluid of Prandtl number Pr=0.7 confined in a cube, for Rayleigh numbers of 10^{6} and 10^{8}. The model solves the unsteady Navier-Stokes equations under the Boussinesq approximation, using a dynamic Smagorinsky model with a Lagrangian averaging technique for the subgrid terms. Under fully developed conditions the flow topology is characterized by a large-scale circulation (LSC) developing in a Plane containing one of the Diagonals of the cell, while two counter-rotating vortices consequently develop in the other Diagonal Plane, resulting in a strong inflow at the horizontal midPlane. This flow structure is not static, with the LSC undergoing nonperiodic reorientations, or switching, between the two Diagonal Planes; hence, we supplement the observations of the three-dimensional time-averaged flow structures with single point measurements (time series) to shed light on the dynamics of the reorientations. For all observations, this switching results from a lateral rotation of the LSC in which some finite time spent in a transient state where the large-scale circulation is parallel to one set of side walls; there are, importantly, no observations consistent with so-called cessations of the LSC, in which it decays and then reforms in another Plane without such a rotation. The average switching rate for the LSC is in excellent agreement with the results of Bai et al. [K. Bai, D. Ji, and E. Brown, Phys. Rev. E 93, 023117 (2016)PLEEE81539-375510.1103/PhysRevE.93.023117].
Daisuke Sekine - One of the best experts on this subject based on the ideXlab platform.
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Test-retest reliability of and age-related changes in the subjective postural vertical on the Diagonal Plane in healthy subjects
Attention Perception & Psychophysics, 2019Co-Authors: Kazuhiro Fukata, Kazu Amimoto, Daisuke Sekine, Yuka Ikarashi, Yuji Fujino, Masahide Inoue, Mamiko Inoue, Shunichi Ishihara, Hidetoshi Takahashi, Shigeru MakitaAbstract:The subjective postural vertical (SPV) reflects gravity perception when the eyes are closed. Changes in the SPV on both the frontal and sagittal Planes occur in response to neurological disorders and aging; however, these changes on the Diagonal Plane are unclear. Here we examined test–retest reliability (n=16) of and age-related changes (n=38) in the SPV on the Diagonal Plane. Subjects sat on an electrical vertical board (EVB), which was used to measure the SPV on the Diagonal Plane. An experimenter controlled and moved the EVB seat at a constant speed on the Diagonal Plane and measured the seat’s tilt using a digital inclinometer when subjects verbally reported that they had reached a true vertical position. Measurement was performed for eight trials, and the mean (tilt direction) and standard deviation (variability) were calculated. To determine test–retest reliability, the same experimenter repeatedly measured the SPV 1 week later. To assess age-related changes, tilt direction and variability were compared between the young (n=20) and elderly (n=18) groups. Test–retest reliability on the right and left Diagonal Planes was 0.61 or more. Moreover, tilt direction on the right Diagonal Plane – but not on the left Diagonal Plane – indicated a significant Diagonally backward deviation in the elderly group compared with that in the young group. Variability was significantly higher in the elderly group on both Planes. SPV measurement on the Diagonal Plane was indicated, and age-related changes were identified. Thus, future studies should assess the potential clinical applications of SPV in neurological disorders.
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Analysis of the subjective postural vertical on Diagonal Plane in elderly subjects and left hemiparetic patients after stroke
Annals of Physical and Rehabilitation Medicine, 2018Co-Authors: Daisuke Sekine, Kazuhiro Fukata, Kazu Amimoto, Yuji Fujino, Mamiko Inoue, Hidetoshi Takahashi, Yosuke Takahashi, Shigeru MakitaAbstract:Introduction/Background The subjective postural vertical (SPV) in healthy subjects is robustly maintained by integrating somatosensory and vestibular information, and extremely correct on frontal and sagittal Plane. It is well-known that brain injury patients indicate disturbance of SPV on frontal or sagittal Plane. On the other hand, stroke patients frequently fall paretic side and backward, but SPV on Diagonal Plane in normal subjects and stroke patients is unclear. The purpose of present study was to clarify the difference of SPV on Diagonal Plane between elderly subjects and stroke patients. Material and method The subjects comprised 14 elderly subjects (control group) and 10 left hemiparetic patients (LHP group). All subjects provided their written informed consent to take part in the study. SPV was measured using an electrical vertical board (EVB). The subjects sat on the EVB and were moved in the opposite direction from the left-backward or right-forward. The tilt of the seat when the subject feels and judges vertical position was recorded with a digital inclinometer. The mean (tilt direction) and standard deviation (variability) of eight trials were calculated. A true vertical position was considered 0°, Diagonally backward and Diagonally forward was treated as negative and positive, respectively. The values of SPV were compared between groups using the unpaired t-test (P Results There was no difference between control group (66.8 ± 9.2 years [mean ± SD]) and LHP groups (67.5 ± 10.8 years) in age. In tilt direction, LHP group (−2.5 ± 0.7°) demonstrated significant tilt backward to the left than control group (−1.3 ± 1.4°). Variability was significantly higher in LHP (5.4 ± 2.0°) than control (2.5 ± 0.9°). Conclusion In stroke patients, tilt direction deviated to the Diagonally backward and the judgement of verticality was unstable. These results suggest a possibility to explain the tilt of sitting posture and the difficulty of transfer movement in stroke patients.
Kazuhiro Fukata - One of the best experts on this subject based on the ideXlab platform.
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Test-retest reliability of and age-related changes in the subjective postural vertical on the Diagonal Plane in healthy subjects
Attention Perception & Psychophysics, 2019Co-Authors: Kazuhiro Fukata, Kazu Amimoto, Daisuke Sekine, Yuka Ikarashi, Yuji Fujino, Masahide Inoue, Mamiko Inoue, Shunichi Ishihara, Hidetoshi Takahashi, Shigeru MakitaAbstract:The subjective postural vertical (SPV) reflects gravity perception when the eyes are closed. Changes in the SPV on both the frontal and sagittal Planes occur in response to neurological disorders and aging; however, these changes on the Diagonal Plane are unclear. Here we examined test–retest reliability (n=16) of and age-related changes (n=38) in the SPV on the Diagonal Plane. Subjects sat on an electrical vertical board (EVB), which was used to measure the SPV on the Diagonal Plane. An experimenter controlled and moved the EVB seat at a constant speed on the Diagonal Plane and measured the seat’s tilt using a digital inclinometer when subjects verbally reported that they had reached a true vertical position. Measurement was performed for eight trials, and the mean (tilt direction) and standard deviation (variability) were calculated. To determine test–retest reliability, the same experimenter repeatedly measured the SPV 1 week later. To assess age-related changes, tilt direction and variability were compared between the young (n=20) and elderly (n=18) groups. Test–retest reliability on the right and left Diagonal Planes was 0.61 or more. Moreover, tilt direction on the right Diagonal Plane – but not on the left Diagonal Plane – indicated a significant Diagonally backward deviation in the elderly group compared with that in the young group. Variability was significantly higher in the elderly group on both Planes. SPV measurement on the Diagonal Plane was indicated, and age-related changes were identified. Thus, future studies should assess the potential clinical applications of SPV in neurological disorders.
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Analysis of the subjective postural vertical on Diagonal Plane in elderly subjects and left hemiparetic patients after stroke
Annals of Physical and Rehabilitation Medicine, 2018Co-Authors: Daisuke Sekine, Kazuhiro Fukata, Kazu Amimoto, Yuji Fujino, Mamiko Inoue, Hidetoshi Takahashi, Yosuke Takahashi, Shigeru MakitaAbstract:Introduction/Background The subjective postural vertical (SPV) in healthy subjects is robustly maintained by integrating somatosensory and vestibular information, and extremely correct on frontal and sagittal Plane. It is well-known that brain injury patients indicate disturbance of SPV on frontal or sagittal Plane. On the other hand, stroke patients frequently fall paretic side and backward, but SPV on Diagonal Plane in normal subjects and stroke patients is unclear. The purpose of present study was to clarify the difference of SPV on Diagonal Plane between elderly subjects and stroke patients. Material and method The subjects comprised 14 elderly subjects (control group) and 10 left hemiparetic patients (LHP group). All subjects provided their written informed consent to take part in the study. SPV was measured using an electrical vertical board (EVB). The subjects sat on the EVB and were moved in the opposite direction from the left-backward or right-forward. The tilt of the seat when the subject feels and judges vertical position was recorded with a digital inclinometer. The mean (tilt direction) and standard deviation (variability) of eight trials were calculated. A true vertical position was considered 0°, Diagonally backward and Diagonally forward was treated as negative and positive, respectively. The values of SPV were compared between groups using the unpaired t-test (P Results There was no difference between control group (66.8 ± 9.2 years [mean ± SD]) and LHP groups (67.5 ± 10.8 years) in age. In tilt direction, LHP group (−2.5 ± 0.7°) demonstrated significant tilt backward to the left than control group (−1.3 ± 1.4°). Variability was significantly higher in LHP (5.4 ± 2.0°) than control (2.5 ± 0.9°). Conclusion In stroke patients, tilt direction deviated to the Diagonally backward and the judgement of verticality was unstable. These results suggest a possibility to explain the tilt of sitting posture and the difficulty of transfer movement in stroke patients.
Najmeh Foroozani - One of the best experts on this subject based on the ideXlab platform.
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Reorientations of the large-scale flow in turbulent convection in a cube.
Physical Review E, 2017Co-Authors: Najmeh Foroozani, Joseph Niemela, Vincenzo Armenio, Katepalli R. SreenivasanAbstract:Large-eddy simulations of turbulent Rayleigh-Benard convection were conducted for a fluid of Prandtl number Pr=0.7 confined in a cube, for Rayleigh numbers of 10^{6} and 10^{8}. The model solves the unsteady Navier-Stokes equations under the Boussinesq approximation, using a dynamic Smagorinsky model with a Lagrangian averaging technique for the subgrid terms. Under fully developed conditions the flow topology is characterized by a large-scale circulation (LSC) developing in a Plane containing one of the Diagonals of the cell, while two counter-rotating vortices consequently develop in the other Diagonal Plane, resulting in a strong inflow at the horizontal midPlane. This flow structure is not static, with the LSC undergoing nonperiodic reorientations, or switching, between the two Diagonal Planes; hence, we supplement the observations of the three-dimensional time-averaged flow structures with single point measurements (time series) to shed light on the dynamics of the reorientations. For all observations, this switching results from a lateral rotation of the LSC in which some finite time spent in a transient state where the large-scale circulation is parallel to one set of side walls; there are, importantly, no observations consistent with so-called cessations of the LSC, in which it decays and then reforms in another Plane without such a rotation. The average switching rate for the LSC is in excellent agreement with the results of Bai et al. [K. Bai, D. Ji, and E. Brown, Phys. Rev. E 93, 023117 (2016)PLEEE81539-375510.1103/PhysRevE.93.023117].
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Reorientations of the large-scale flow in turbulent convection in a cube.
Physical review. E, 2017Co-Authors: Najmeh Foroozani, Vincenzo Armenio, J J Niemela, Katepalli R. SreenivasanAbstract:Large-eddy simulations of turbulent Rayleigh-Bénard convection were conducted for a fluid of Prandtl number Pr=0.7 confined in a cube, for Rayleigh numbers of 10^{6} and 10^{8}. The model solves the unsteady Navier-Stokes equations under the Boussinesq approximation, using a dynamic Smagorinsky model with a Lagrangian averaging technique for the subgrid terms. Under fully developed conditions the flow topology is characterized by a large-scale circulation (LSC) developing in a Plane containing one of the Diagonals of the cell, while two counter-rotating vortices consequently develop in the other Diagonal Plane, resulting in a strong inflow at the horizontal midPlane. This flow structure is not static, with the LSC undergoing nonperiodic reorientations, or switching, between the two Diagonal Planes; hence, we supplement the observations of the three-dimensional time-averaged flow structures with single point measurements (time series) to shed light on the dynamics of the reorientations. For all observations, this switching results from a lateral rotation of the LSC in which some finite time spent in a transient state where the large-scale circulation is parallel to one set of side walls; there are, importantly, no observations consistent with so-called cessations of the LSC, in which it decays and then reforms in another Plane without such a rotation. The average switching rate for the LSC is in excellent agreement with the results of Bai et al. [K. Bai, D. Ji, and E. Brown, Phys. Rev. E 93, 023117 (2016)PLEEE81539-375510.1103/PhysRevE.93.023117].