460 research outputs found
Mathematical Model for The Transmission of Lymphatic Filariasis and Its Applications
We have constructed a stochastic transmission model for lymphatic filariasis caused by Wuchereria bancrofti, and have analyzed its prevalence using computer simulations. In Pondicherry, India, where Wuchereria bancrofti has been spreading, the Vector Control Research Centre has carried out an integrated vector control strategy against malaria and filariasis for five years (1981~1985) with good results reported. Our study was aimed at evaluating the effect of vector control in the context of Pondicherry, and in particular the continuous effect for the post-control period. In this paper, we have used the LYMFASIM model proposed by Plaisier et al., the carrying capacity model by Rochet and the population dynamics model by us. In the LYMFASIM model and the carrying capacity model, we have modified the quantities of parameters in order to fit the models to the parasitological, entomological and epidemiological data in Pondicherry. We have combined the improved LYMFASIM model with the other models. Through simulations of our combinated model, we have compared the prevalence rate in the human population as well as the mean number of L3-larvae in the mosquito population, with and without vector control. As a result, the simulations show that the prevalence rate would be restrained for a long time even if only a small continuous effect of the vector control remains in the post-control period. However, the mean number of L3-larvae would recovered within a short time comparatively. This is because of the differences in life spans between human and mosquito as well as the incubation periods between the adult worm in the human host and L3-larvae in the mosquito vector
THE INFLUENCE OF WALKING SPEED ON SYMMETRY FOR TEMPORAL-SPATIAL AND GRF PARAMETERS IN BACKWARD WALKING
In general, changes in walking speed are known to influence many biomechanical characteristics of human locomotion. Backward walking (BW) is one of the unique strategies of human locomotion, but there is a little information in BW. The purpose of this study was to investigate whether or not walking speed influences on symmetry for temporal-spatial parameters and GRF in BW. Ten healthy subjects were asked to walk on a walk-way with force platform at three times on three speed conditions. The influence of walking speed on temporal-spatial parameters and GRF parameters were founded, and some gait parameters showed asymmetry. And also .the calculated SI were showing asymmetry, so the characteristics of backward walking would be influenced walking speed and have possibility of exist some asymmetrical movements in lower leg
The prevalence of Plasmodium vivax in Vanuatu Islands: Computer simulation of malaria control trails
We have estimated the degree of transmission of Plasmodium vivax malaria in Vanuatu Islands, eastern Melanesia with the aid of the computer simulations, which has been carried out on the platform of a mathematical transmission model. The malaria caused by Plasmodium vivax has a relapse character, which arises from hypnozoites in the liver. This phenomen makes a malaria control strategy difficult. When the mass drug administration is executed, the prevalence of Plasmodium vivax decreases moderately as compared with that of Plasmodium falciparum, and it recovers before long being affected by the relapses. The simulations suggest that one cannot attain the eradication of Plasmodium vivax malaria without the concentrated execution of the mass drug administration and the vector control that fairly reduces the vactorial capacity
A COMPARATIVE STUDY BETWEEN CROSS AND DOWN-THE-LINE FOREHAND
The purpose of this study was to clarify the mechanics involved in making two different shots, namely, cross (C) and down-the-line (D), under a two-choice reaction condition in soft-tennis. Using the images from two high-speed cameras, forehand drive motions under these conditions were analyzed with the direct linear transformation procedure. The authors considered that for the selected objects of analysis, the experimental environment significantly affected the actions. Anatomical rotations of the upper extremity and center of gravity (COG) of the subjects during forehand motions were compared between C and D. Some differences were observed in the external rotation of the shoulder and the lateral component of COG. The results were discussed from the perspective of the way in which expert players made ball-racket contact under the choice reaction condition. This was considered to be a high time-pressure condition
MEASURING OPEN SPACE QUANTITATIVELY IN ONE-UP-ONE-BACK FORMATION DURING SOFT-TENNIS DOUBLES GAME
The purpose of this study was to quantitatively define and measure the area of open space in one-up-one-back formation adopted in soft-tennis doubles game. Using the film images of real games, the variables of forehand ground strokes and ball bounces for 153 shots were analyzed with the direct linear transformation procedure. Further taking types of stroke technique and game situations into considerations, horizontal distance between contact point and landing point of shots were predicted by multiple regression analysis. As the result, four scales (two for stroke characteristics, stroke technique, and game situation) were selected as significant predictors. Then on the basis of these data, we predicted the horizontal distance of shots and defined the potential areas on court as "open space" in which shots could be landed, and actually computed the area of open space on one case in the game
M-protein kinetics in multiple myeloma treated with melphalan, ifosfamide, prednisolone, nitrosourea and vincristine in combination.
Patients with multiple myeloma were treated chemotherapeutically with a combination of melphalan, ifosfamide, prednisolone, nitrosourea and vincristine (MIP-NV therapy). The M-protein kinetics during the course of MIP-NV therapy was studied. The kinetics of serum and urinary M-protein in the first cycle of the chemotherapy was classified into four patterns, and the mode of change in the M-protein level over the entire course of chemotherapy was classified into four prototypes. There were intimate relationships among M-protein kinetics patterns in the first cycle of the chemotherapy, the effect of the chemotherapy on M-protein reduction, maturity of myeloma cells, pretreatment labeling index and clinical stage of the disease. Moreover, analyzing the prototypes, it was found that both the time for maximum M-protein reduction and the rate of increase in the M-protein level after maximum M-protein reduction affected the survival time. To predict the effect of the chemotherapy on M-protein reduction and survival time, it was useful to analyze subgroups, which were classified according to the M-protein kinetics pattern in the first cycle, the time for maximum M-protein reduction and the rate of increase in the M-protein level after maximum M-protein reduction.</p
Prevalence of periCardial effusion in patients with rheumatoid arthritis -An echocardiographic study-
In order to determine the incidence of pericardial effusion in rheumatoid arthritis (RA), echocardiographic studies were performed on patients with classical or definite RA as determined by ARA criteria, none of whom showed any clinical cardiac symptoms at the time of examination. Of 50 RA patients studied so far, fifteen (30%) showed evidence of posterior pericardial effusion, as recorded on the strip charts. Additionally, in one full-blown case of rheumatoid vasculitis, massive accumulation of pericardial fluid was demonstrable. Compared to those without pericardial effusion, patients shown to have pericardial fluid tended to have decreased RBC, Hct, Hgb, serum protein concentration and increased ESR. The statistical difference between the two groups was significant (P<0.005). The most conspicuous difference between the two, however, was noted in the degree of hypoalbuminemia that is more profound in the effusion positive group (P<0.005). The possible cause of fluid retention in the pericardial cavity in RA was briefly discussed
Simulations on Prevalence of Echinococcus multilocularis in Hokkaido on the Basis of Vole Population Dynamics
In our study, we have investigated the influence of the intermediate host population density on the prevalence of Echinococcus multilocularis in the definitive host using a mathematical model of transmission. For the vole population (intermediate host) in Hokkaido, a model of population dynamics has been constructed in this paper which follows the seasonal and annual fluctuations. In the northeastern area, the vole density appears to fluctuate periodically with a 4 year cycle. The prevalence of Echinococcus multilocularis in the fox population (definitive host) can be affected by the density of vole through the fox ingesting infectious voles. Therefore we have prepared a food habit function of foxes and the logistic distribution has been proposed. The simulations which have been carried out using the mathematical model for transmission of Echinococcus multilocularis together with the vole dynamics have indicated that the prevalence in foxes is correlated and synchronized with the population dynamics of vole. In addition they have also made us recognize that it is necessary to introduce a suitable food habit function into the transmission model
THE STEREOSCOPIC EFFECT OF A SPINNING BATON FLIGHT
INTRODUCTION: In baton twirling, catching a spinning baton is one of fundamental skills. For successful baton-catching, baton twirlers acquire the efficient visual search behavior setting their gaze not only to parabolic flight but spin of baton (Takahashi et al., 2007). Mazyn et al. (2007) reported that the learning to catch a ball is affected by stereo vision providing accurate depth perception of the ball’s movement. We consider a CAVE Automatic Virtual Environment system, 3D virtual reality display with stereoscopic effect, may be used as a training tool for baton-catching. This preliminary study aimed to examine the stereoscopic effect on the virtual reality simulation of baton-catching in a CAVE system. We reconstructed stereo- and monoscopic stimuli of spinning baton flight simulated by 3D motion capture data and assessed observer’s impression of them
COMPUTER-BASED LEARNING USING CAPTURED TENNIS SERVE MOTION
INTRODUCTION: Motion analysis techniques have revealed kinetic and kinematic aspects of the sport motions, however, more intuitive resources, e.g. visual feedback, would be recommended to the sport practitioners. Féry & Crognier (2001) showed that essential anticipatory information is contained in the opponent’s stroke motion whatever the tactical significance of the situation. Fukuhara et al (2005) proposed that computer graphics animation have possibilities to be utilized in the sport visual training. This study aimed to explore the effect of computer-based visual learning in tennis by testing the judgment performance of novice player who viewed a captured tennis serve animation
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