110 research outputs found

    Temporal properties of the speed-accuracy trade-off for arm-pointing movements in various directions around the body

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    Human body movements are based on the intrinsic trade-off between speed and accuracy. Fitts’s law (1954) shows that the time required for movement is represented by a simple logarithmic equation and is applicable to a variety of movements. However, few studies have determined the role of the direction in modulating the performance of upper limb movements and the effects of the interactions between direction and distance and between direction and target size. This study examined the variations in temporal properties of the speed-accuracy trade-off in arm-pointing movements that directly manipulate objects according to the direction, distance, and target size. Participants performed pointing movements to the targets with 3 different sizes presented at 15 locations (5 directions and 3 distances) on a horizontal plane. Movement time (MT) for each trial in each condition was obtained. Subsequently, Mackenzie’s model (1992), MT = a + b log₂(D/W +1), where D and W represent the distance and width of the target, respectively, was fitted. The slope factor b, a fitted parameter in the equation, was calculated and evaluated according to the changes in the direction, distance, and target size. The results showed that MTs exhibited anisotropy in the hemifield, being the smallest in the right-forward direction. Additionally, the slope factor b, as a function of distance, was smaller in the rightward direction than in the forward and left-forward directions. These results suggest that the degree of difficulty of upper limb movements expands heterogeneously in various directions around the body

    Power of Quantum Computation with Few Clean Qubits

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    This paper investigates the power of polynomial-time quantum computation in which only a very limited number of qubits are initially clean in the |0> state, and all the remaining qubits are initially in the totally mixed state. No initializations of qubits are allowed during the computation, nor intermediate measurements. The main results of this paper are unexpectedly strong error-reducible properties of such quantum computations. It is proved that any problem solvable by a polynomial-time quantum computation with one-sided bounded error that uses logarithmically many clean qubits can also be solvable with exponentially small one-sided error using just two clean qubits, and with polynomially small one-sided error using just one clean qubit. It is further proved in the case of two-sided bounded error that any problem solvable by such a computation with a constant gap between completeness and soundness using logarithmically many clean qubits can also be solvable with exponentially small two-sided error using just two clean qubits. If only one clean qubit is available, the problem is again still solvable with exponentially small error in one of the completeness and soundness and polynomially small error in the other. As an immediate consequence of the above result for the two-sided-error case, it follows that the TRACE ESTIMATION problem defined with fixed constant threshold parameters is complete for the classes of problems solvable by polynomial-time quantum computations with completeness 2/3 and soundness 1/3 using logarithmically many clean qubits and just one clean qubit. The techniques used for proving the error-reduction results may be of independent interest in themselves, and one of the technical tools can also be used to show the hardness of weak classical simulations of one-clean-qubit computations (i.e., DQC1 computations).Comment: 44 pages + cover page; the results in Section 8 are overlapping with the main results in arXiv:1409.677

    REMOVAL OF DISSOLVED METAL IONS BY BIOGENIC MANGANESE OXIDES PRODUCED BY ENRICHMENT CULTURES OF MANGANESE-OXIDIZING BACTERIA

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    Joint Research on Environmental Science and Technology for the Eart

    Evaluating on-demand video lectures

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    The popularity of online classes in university education has grown rapidly since the COVID-19 outbreak. This study aims to examine the association between the detailed characteristics / various contexts of students and the evaluation of online classes. An online questionnaire survey administered to third- and fourth-grade medical students of Tokushima University in September 2021—with 101 (42.8%) valid responses—showed the respondents’ general impressions, comprehension, convenience, and desire for online classes even after the pandemic ends were significantly higher for the on-demand lectures than for simultaneous online classes. Notably, students who did not do other things while watching video lectures (10.9%) rated on-demand lectures as facilitating significantly higher impression, comprehension, and convenience than those who did other things (89.1%). A multivariate analysis revealed that students who did not do anything else while watching, whose waking time changed slightly, who commuted to school for shorter periods, who were not good at morning lectures, and who watched at high speed rated the video lectures highly. Thus, video lectures are appreciated by students who are committed to learning, which is a positive result for the future of on-demand education

    PMR and RS3PE Syndrome

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    Polymyalgia rheumatica (PMR) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome are common inflammatory rheumatic diseases in the elderly. In this study, we investigated the difference of the therapeutic responses between patients with PMR and RS3PE syndrome. Twenty-four patients with PMR and 12 patients with RS3PE syndrome were treated with initial dosages of 10-20 mg per day oral prednisolone, and the dosages were then tapered. Percentages of patients with negative c-reactive protein (CRP) after 8-week treatment were significantly more in RS3PE syndrome than in PMR. Percentages of patients with relapse during one-year treatment were less likely to be in RS3PE syndrome than in PMR. These differences observed between the two disorders were not associated with the level of initial CRP. There was no significant difference in percentages of patients with prednisolone-free remission after two-year treatment between PMR and RS3PE syndrome. These results indicate that the early response to the treatment is greater in RS3PE syndrome than in PMR

    Past infections and low ACPA in RA

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    Background : Rheumatoid arthritis (RA), an autoimmune disease of unknown etiology, is believed to occur as the result of actions of genetic and environmental factors. In this study, we examined the relation of past histories about infectious diseases with the levels anti-citrullinated protein autoantibodies (ACPA) in RA. Methods : Results of a questionnaire about histories of infectious diseases were obtained from 85 patients with RA, and were analyzed. Results : Significantly lower level of ACPA was detected in patients with the history of tonsillitis, otitis media or urinary cystitis than in those without it. There was no difference in the level of ACPA in RA patients between with and without cold / influenza, rubella, chickenpox, herpes labialis or herpes zoster. When RA patients were divided into two groups, high-level and low-level ACPA, multiple logistic regression analysis revealed that the history of otitis media was a significantly independent factor for the low level of ACPA. There was no significant relation between the level of rheumatoid factor and histories of infectious diseases. Conclusion : This study clarified that the past history of otitis media is associated with the low level of ACPA in RA

    CRP in PMR and RS3PE syndrome

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    Polymyalgia rheumatica (PMR) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome are common inflammatory rheumatic diseases in the elderly. In this study, we investigate predictive factors which correspond to subsequent disease control of PMR and RS3PE syndrome. Twenty four patients, which contained 18 PMR and 6 RS3PE syndrome, were treated with initial dosages of 10-20 mg per day oral prednisolone, and the dosage of prednisolone was then tapered. Significantly higher initial CRP was observed in patients with poor disease control than in those with good disease control afterwards. The number of patients with negative CRP after 4 weeks was significantly more in patients with good disease control after 1 year than in those with poor disease control. Patients were shown to be in good disease control status after 1 year when CRP after 4 weeks became negative even if they had initial high CRP. Our study clarify that to make CRP negative after 4 weeks is associated with subsequent suppression of the disease activity and with decreased dosages of corticosteroids
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