302 research outputs found
ASSOCIATION OF CHANGES IN SPATIOTEMPORAL VARIABLES AT EACH STEP WITH 100-M SPRINT PERFORMANCE IN PREADOLESCENT SPRINTERS
The purpose of this study was to investigate the association of acceleration and changes in spatiotemporal variables at each step with 100-m sprint performance in preadolescent sprinters. Twenty-six boys performed 100-m sprints, and their spatiotemporal variables were measured at each step. Acceleration was negatively correlated with the 100-m sprint time from the 1st to 21st step. The rates of change in step frequency were positively correlated with acceleration at the 2nd and 3rd step. Posterior to 3rd step, rates of change in step length were positively correlated with acceleration. The results suggest that the acceleration caused by increase in step frequency and step length up to reaching to the maximal sprint velocity is effective for improving the 100-m sprint time
Near-Ultraviolet and Visible Spectroscopy of HAYABUSA Spacecraft Re-entry
HAYABUSA is the first spacecraft ever to land on and lift off from any
celestial body other than the moon. The mission, which returned asteroid
samples to the Earth while overcoming various technical hurdles, ended on June
13, 2010, with the planned atmospheric re-entry. In order to safely deliver the
sample return capsule, the HAYABUSA spacecraft ended its 7-year journey in a
brilliant "artificial fireball" over the Australian desert. Spectroscopic
observation was carried out in the near-ultraviolet and visible wavelengths
between 3000 and 7500 \AA at 3 - 20 \AA resolution. Approximately 100 atomic
lines such as Fe I, Mg I, Na I, Al I, Cr I, Mn I, Ni I, Ti I, Li I, Zn I, O I,
and N I were identified from the spacecraft. Exotic atoms such as Cu I, Mo I,
Xe I and Hg I were also detected. A strong Li I line (6708 \AA) at a height of
~55 km originated from the onboard Li-Ion batteries. The FeO molecule bands at
a height of ~63 km were probably formed in the wake of the spacecraft. The
effective excitation temperature as determined from the atomic lines varied
from 4500 K to 6000 K. The observed number density of Fe I was about 10 times
more abundant than Mg I after the spacecraft explosion. N2+(1-) bands from a
shock layer and CN violet bands from the sample return capsule's ablating heat
shield were dominant molecular bands in the near-ultraviolet region of 3000 -
4000 \AA. OH(A-X) band was likely to exist around 3092 \AA. A strong shock
layer from the HAYABUSA spacecraft was rapidly formed at heights between 93 km
and 83 km, which was confirmed by detection of N2+(1-) bands with a vibration
temperature of ~13000 K. Gray-body temperature of the capsule at a height of
~42 km was estimated to be ~2437 K which is matched to a theoretical
prediction. The final message of the HAYABUSA spacecraft and its sample return
capsule are discussed through our spectroscopy.Comment: Accepted for publication in PASJ, 22 pages, 7 figures, 6 table
Role of proline residue in the channel-forming and catecholamine-releasing activities of the peptaibol, trichosporin-B-VIa
AbstractTrichosporin-B-VIa (TS-B-VIa) has a Pro14-kinked helical structure which is considered to be important for the formation of peptaibol-type ion-channels in lipid bilayer membranes. TS-B-VIa and its analog [Aid14]TS-B-VIa with Pro → Aib substitution at position 14, resulting in a straight helical structure, were tested for ion-channel-forming activity in planar lipid bilayer membranes and for ability to induce catecholamine secretion from cultured bovine adrenal chromaffin cells. Voltage-dependent multi-channel conductance, which is characteristic of TS-B-VIa, was also observed for [Aid14]TS-B-VIa. In single-channel measurements, current fluctuations induced by [Aid14]TS-B-VIa had a shorter life-time and showed fewer substates than those induced by TS-B-VIa. Catecholamine secretion induced by these peptides at low concentrations is completely Ca2+-dependent. At high concentrations, TS-B-VIa-induced secretion was partly independent of external Ca 2+, but this was not the case for the analog. The differences of behavior can be explained in terms of the differences of hydrophobicity, amphiphilicity, and magnitude of dipole moment due to the conformational changes around position 14 and the C-terminal domain caused by the Pro → Aib substitution
Asymmetrical membrane fluidity of bovine adrenal chromaffin cells and granules and effect of trichosporin-B-VIa
AbstractWe examined membrane fluidity of bovine adrenal chromaffin cells and chromaffin granules using cationic trimethylammonium derivative of diphenylhexatriene (TMA-DPH) as a fluorescence probe. After adding TMA-DPH to the suspension of chromaffin cells and that of granules, it first bound to the outer layer of the plasma membrane of the cells and that of the granule membrane, then gradually penetrated the inner layer of each membrane and distributed to both leaflets of the respective membranes. Accompanying increases in the ratio of incorporated probe on the cytoplasmic side of the chromaffin cell membrane, its fluorescence anisotropy gradually decreased. However, in chromaffin granules, the fluorescence anisotropy gradually increased with increases in the ratio of incorporated probe. These findings suggest that the inner layer of the plasma membrane and outer layer of the granular membrane are more fluid than the corresponding side of each membrane, which is suitable for the fusion between both membranes. We also examined the effect of trichosporin-B-VIa, a fungal ion channel forming α-aminoisobutyric acid-containing peptide, on the fluidity of chromaffin cells using TMA-DPH. The peptide decreased the fluorescence anisotropy and increased the fluorescence intensity in the concentration range that induced Ca2+ dependent catecholamine secretion, suggesting that a change in lipid dynamics of the lipid bilayer of the plasma membrane was induced by this peptide
Developing a Curriculum for Explorative Proving in Lower Secondary School Geometry
ArticleProceedings of the 13th International Congress on Mathematical Education (ICME-13).Hamburg, Germany, 2016-7-24/31.conference pape
Successful Management of Pregnancy Complicated by Klippel-Trenaunay Syndrome Using MR Angiography-Based Evaluation
Klippel-Trenaunay syndrome (KTS) is a rare congenital disease, and extensive cutaneous hemangiomas and abnormal venous vessels are characteristic. In our case, to manage her pregnancy with KTS, whole-body MRA was performed before delivery. A 29-year-old woman was referred at 28 weeks because of prominent vulvovaginal varicosities due to KTS. At 35 weeks, hypertrophy and multiple venous varicosities of her leg as well as massive vulvovaginal varicosities became prominent with a normal coagulation profile. Systematic MRAs revealed hemangiomas and varicosities in the right leg, the lower abdomen, and the pubic region, while no obvious AVM was detected around the bronchial tube and spine. We decided to deliver her baby by cesarean section at 37 weeks under general anesthesia, and a healthy baby was delivered. No blood transfusion was required. Prophylaxis against thrombosis was performed after the operation. She was discharged with her baby. Her vulvovaginal varicosities shrunk considerably one month later
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