A THREE-DIMENSIONAL CINEMATOGRAPHIC ANALYSIS OF THE BASEBALL PITCH

Pitching is one of the most important aspects of the game of baseball. However, only a small number of quantitative biomechanical studies have been reported (Feltner & Dapena, 1986). Specifically, there have been few studies of the motion of the forearm and wrist joints during a pitching action. The purpose of this study is to record the changes in angles and angular velocities of the shoulder, elbow, radioulnar and wrist joints during a baseball pitch. In this study, three dimensional (3-D) high-speed cinematography was used to record the fastball pitches of varsity baseball pitchers

A Three-Dimensional Cinematographic Analysis of Badminton Strokes

Badminton and tennis are two of the most popular striking activities, Broer & Zernicke (1979) stated that one evident difference between the two sports skills was the degree to which the wrist snap was used. They stated that the wrist snap just before impact was the most essential action of badminton strokes and it was enabled by the lightness of the badminton racket. Gowitzke & Waddell (1979) analyzed forehand and backhand smash strokes, representative of the most powerful overhead striking motions in badminton. They concluded that medial rotation of the humerus at the shoulder joint and pronation of the forearm at the radio-ulnar joints were the principal contributing movements for the forehand smash, In badminton strokes, many joint actions in three planes are involved in the striking motion, so that two-dimensional procedures are insufficient for analyzing the stroke motion of badminton. Relatively small numbers of biomechanical studies have been completed on kinematic parameters of badminton strokes. Quantitative studies with threedimensional procedures have been even more limited. The purpose of this investigation was to determine the changes of joint angles of the upper body during the execution of the drop shot and the cut shot in badminton using three dimensional cinematography

Relationships between a roller and a dynamic pressure distribution in circular hydraulic jumps

We investigated numerically the relation between a roller and the pressure distribution to clarify the dynamics of the roller in circular hydraulic jumps. We found that a roller which characterizes a type II jump is associated with two high pressure regions after the jump, while a type I jump (without the roller) is associated with only one high pressure region. Our numerical results show that building up an appropriate pressure field is essential for a roller.Comment: 10 pages, 7 PS files. To appear in PR

MOMENT OF FORCE AND MECHANICAL POWER IN GIANT SWING ON THE HORIZONTAL BAR

Introduction In the giant swing backwards, frictional force acts upon the grip and air resistance acts upon the whole body (Hay, 1978; and Kreighbaum and Barthels, 1981). These resistive forces affect the rotation of the body and cause a loss of mechanical energy. Therefore in order to complete the rotation, the gymnast has to offset these energy losses using muscular work (Hay, 1978). It has been reported that changes in mechanical energy occur during the backward giant swing. The total energy of the body is decreased during the second half of the downswing and almost recovered in the first half of the upswing. These results suggest that muscular work is done in the first half of the upswing to offset the loss of mechanical energy in the last half of the downswing (Okamoto, Sakurai, Ikegami and Yabe)

The Changes in Mechanical Energy During the Giant Swing Backward on the Horizontal Bar

In the giant swing backward, mechanical energy of the whole body is decreased due to friction between gymnast hands and the bar, and to air resistance. To complete the rotation, the gymnast has to do muscular work to offset these energy losses. Total mechanical energy changes with the relationship between energy loss and muscular work. Therefore, for biomechanical investigation of the giant swing backward, it is important to have an accurate measure of the mechanical energy changes of the whole body. Although there are many studies of energetics of the human fundamental movement such as walking and running, the mechanical energy changes of the whole body have not been reported during the giant swing backward on the horizontal bar. The purpose of this study is to report the mechanical energy changes of the whole body, and to identify the muscular work donc by the gymnast during the giant swing backward on the horizontal bar

Near-infrared spectroscopy and plasma homovanillic acid levels in bipolar disorder: a case report

Misdiagnosis of bipolar disorder is a serious, but not unusual problem for patients. Nevertheless, there are few biomarkers for distinguishing unipolar and bipolar disorder. Near-infrared spectroscopy (NIRS) is a noninvasive and useful method for the measurement of hemoglobin concentration changes in the cortical surface area, which enables the assessment of brain function. We measured NIRS and plasma monoamine metabolite levels in a patient with bipolar disorder. A 22-year-old man was admitted due to major depression. At admission, NIRS findings showed oxygenated hemoglobin reincrease in the posttask period, which is characteristic of schizophrenia. After treatment with paroxetine, he became manic with psychotic symptoms. His plasma level of homovanillic acid just before the manic switch was ten times higher than that just after paroxetine initiation. Treatment with lithium and antipsychotics was successful, and plasma homovanillic acid decreased after treatment. In this case, the NIRS findings may predict a possible risk of a manic switch, which is likely induced by paroxetine. NIRS may be able to help distinguish unipolar and bipolar disorder in clinical settings

Experimental study of energy transport in thin Al and Au foils irradiated with a 263-nm laser

Copyright 1989 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 65(12), 5068-5071, 1989 and may be found at http://dx.doi.org/10.1063/1.34318

Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies

We report the study of far-IR sizes of submillimeter galaxies (SMGs) in relation to their dust-obscured star formation rate (SFR) and active galactic nuclei (AGN) presence, determined using mid-IR photometry. We determined the millimeter-wave ($\lambda_{\rm obs}=1100 \mu$m) sizes of 69 ALMA-identified SMGs, selected with $\geq10$$\sigma$ confidence on ALMA images ($F_{\rm 1100 \mu m}=1.7$--7.4 mJy). We found that all the SMGs are located above an avoidance region in the millimeter size-flux plane, as expected by the Eddington limit for star formation. In order to understand what drives the different millimeter-wave sizes in SMGs, we investigated the relation between millimeter-wave size and AGN fraction for 25 of our SMGs at $z=1$--3. We found that the SMGs for which the mid-IR emission is dominated by star formation or AGN have extended millimeter-sizes, with respective median $R_{\rm c,e} = 1.6^{+0.34}_{-0.21}$ and 1.5$^{+0.93}_{-0.24}$ kpc. Instead, the SMGs for which the mid-IR emission corresponds to star-forming/AGN composites have more compact millimeter-wave sizes, with median $R_{\rm c,e}=1.0^{+0.20}_{-0.20}$ kpc. The relation between millimeter-wave size and AGN fraction suggests that this size may be related to the evolutionary stage of the SMG. The very compact sizes for composite star-forming/AGN systems could be explained by supermassive black holes growing rapidly during the SMG coalescing, star-formation phase.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in ApJ Lette

SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy

We present a multi-wavelength analysis of five submillimeter sources (S_1.1mm = 0.54-2.02 mJy) that were detected during our 1.1-mm-deep continuum survey in the SXDF-UDS-CANDELS field (2 arcmin^2, 1sigma = 0.055 mJy beam^-1) using the Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy (SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If we exclude the two brightest sources, the contribution of the ALMA-detected faint SMGs to the infrared extragalactic background light is estimated to be ~ 4.1^{+5.4}_{-3.0} Jy deg^{-2}, which corresponds to ~ 16^{+22}_{-12}% of the infrared extragalactic background light. This suggests that their contribution to the infrared extragalactic background light is as large as that of bright SMGs. We identified multi-wavelength counterparts of the five ALMA sources. One of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared region despite its infrared luminosity (L_IR ~ 1e12 L_sun or SFR ~ 100 M_sun yr^{-1}). By fitting the spectral energy distributions (SEDs) at the optical-to-near-infrared wavelengths of the remaining four ALMA sources, we obtained the photometric redshifts (z_photo) and stellar masses (M_*): z_photo ~ 1.3-2.5, M_* ~ (3.5-9.5)e10 M_sun. We also derived their star formation rates (SFRs) and specific SFRs (sSFRs) as ~ 30-200 M_sun yr^{-1} and ~ 0.8-2 Gyr^{-1}, respectively. These values imply that they are main-sequence star-forming galaxies.Comment: PASJ accepted, 15 pages, 6 figures, 2 table

Initial Results from the Nobeyama Molecular Gas Observations of Distant Bright Galaxies

We present initial results from the CO survey toward high redshift galaxies using the Nobeyama 45m telescope. Using the new wide bandwidth spectrometer equipped with a two-beam SIS receiver, we have robust new detections of three high redshift (z=1.6-3.4) submillimeter galaxies (SXDF 1100.001, SDP9, and SDP17), one tentative detection (SDSS J160705+533558), and one non-detection (COSMOS-AzTEC1). The galaxies observed during the commissioning phase are sources with known spectroscopic redshifts from previous optical or from wide-band submm spectroscopy. The derived molecular gas mass and line widths from Gaussian fits are ~10^11 Msun and 430-530 km/s, which are consistent with previous CO observations of distant submm galaxies and quasars. The spectrometer that allows a maximum of 32 GHz instantaneous bandwidth will provide new science capabilities at the Nobeyama 45m telescope, allowing us to determine redshifts of bright submm selected galaxies without any prior redshift information.Comment: 4 pages, 1 figure, PASJ Letter Accepte