133 research outputs found

    THE CURRENT SITUATION OF MASTICATORY BEHAVIOR OF FIRST GRADER AT ELEMENTARY SCHOOL: A RELATIONSHIP BETWEEN MASTICATORY ABILITY AND STUDENTS’ LIKES AND DISLIKES

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    Twenty percent of first-graders of a public elementary school in Kanagawa Prefecture were unable to masticate school lunch properly. Teachers encouraged masticate training at school, but it showed no improvement. The purpose of this research was to investigate the characteristics of mastication to find possible methods and more specific mastication education. The subjects were 100 first graders(6~7years old) at public elementary school where school lunch was served with an individual tray. The survey was conducted during school lunchtime by recording the bread crust eating situation. Every student was provided with 8g of bread crust cut into three equal parts. Within one month, on the days when kibinago (herring-like forage fish), cabbage, potatoes, curry rice, bonito, and komatsuna (Japanese Spinach) were served, the subjects were asked about their “Likes or Dislikes” and the food was “Easy to Masticate or Hard to Masticate”.The average of masticatory time during eating bread crust was 76 seconds, the maximum was 151 seconds, and the minimum was 19 seconds. The average of masticatory frequency was 72 times, the maximum was 155 times and the minimum was 27 times. The average masticatory speed was 58 beats per minute (bpm), the fastest was 113 bpm and the slowest was 29 bpm. The most favorite dish was curry rice (99%) and the least favorite dishes were kibinago and bonito (13%, respectively). The highest percentage (27%) of the subjects answered bonito dish as “Hard to Masticate” and the lowest percentage (1%) was curry rice. “Dislike” was significantly associated with “Hard to Masticate” in cabbage (p<0.01) and bonito (p<0.01). The first graders had individual differences in masticatory behavior. It was suggested that “Likes and Dislikes” are related to masticatory ability. If the children practice the mastication of solid foods before entering school, the children might eat more smoothly

    Seismometer Detection of Dust Devil Vortices by Ground Tilt

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    We report seismic signals on a desert playa caused by convective vortices and dust devils. The long-period (10-100s) signatures, with tilts of ~107^{-7} radians, are correlated with the presence of vortices, detected with nearby sensors as sharp temporary pressure drops (0.2-1 mbar) and solar obscuration by dust. We show that the shape and amplitude of the signals, manifesting primarily as horizontal accelerations, can be modeled approximately with a simple quasi-static point-load model of the negative pressure field associated with the vortices acting on the ground as an elastic half space. We suggest the load imposed by a dust devil of diameter D and core pressure {\Delta}Po is ~({\pi}/2){\Delta}PoD2^2, or for a typical terrestrial devil of 5 m diameter and 2 mbar, about the weight of a small car. The tilt depends on the inverse square of distance, and on the elastic properties of the ground, and the large signals we observe are in part due to the relatively soft playa sediment and the shallow installation of the instrument. Ground tilt may be a particularly sensitive means of detecting dust devils. The simple point-load model fails for large dust devils at short ranges, but more elaborate models incorporating the work of Sorrells (1971) may explain some of the more complex features in such cases, taking the vortex winds and ground velocity into account. We discuss some implications for the InSight mission to Mars.Comment: Contributed Article for Bulletin of the Seismological Society of America, Accepted 29th August 201

    Estimations of the Seismic Pressure Noise on Mars Determined from Large Eddy Simulations and Demonstration of Pressure Decorrelation Techniques for the Insight Mission

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    The atmospheric pressure fluctuations on Mars induce an elastic response in the ground that creates a ground tilt, detectable as a seismic signal on the InSight seismometer SEIS. The seismic pressure noise is modeled using Large Eddy Simulations (LES) of the wind and surface pressure at the InSight landing site and a Green’s function ground deformation approach that is subsequently validated via a detailed comparison with two other methods: a spectral approach, and an approach based on Sorrells’ theory (Sorrells,Geophys. J. Int. 26:71–82, 1971; Sorrells et al., Nat. Phys. Sci. 229:14–16, 1971). The horizontal accelerations as a result of the ground tilt due to the LES turbulence-induced pressure fluctuations are found to be typically ∼ 2–40 nm/s2 in amplitude, whereas the direct horizontal acceleration is two orders of magnitude smaller and is thus negligible in comparison. The vertical accelerations are found to be ∼ 0.1–6 nm/s2 in amplitude. These are expected to be worst-case estimates for the seismic noise as we use a half-space approximation; the presence at some (shallow) depth of a harder layer would significantly reduce quasi-static displacement and tilt effects. We show that under calm conditions, a single-pressure measurement is representative of the large-scale pressure field (to a distance of several kilometers), particularly in the prevailing wind direction. However, during windy conditions, small-scale turbulence results in a reduced correlation between the pressure signals, and the single-pressure measurement becomes less representative of the pressure field. The correlation between the seismic signal and the pressure signal is found to be higher for the windiest period because the seismic pressure noise reflects the atmospheric structure close to the seismometer. In the same way that we reduce the atmospheric seismic signal by making use of a pressure sensor that is part of the InSight Auxiliary Payload Sensor Suite, we also the use the synthetic noise data obtained from the LES pressure field to demonstrate a decorrelation strategy. We show that our decorrelation approach is efficient, resulting in a reduction by a factor of ∼ 5 in the observed horizontal tilt noise (in the wind direction) and the vertical noise. This technique can, therefore, be used to remove the pressure signal from the seismic data obtained on Mars during the InSight mission

    SUPERSHELLS AS MOLECULAR CLOUD FACTORIES: PARSEC RESOLUTION OBSERVATIONS OF Hi AND (CO)-C-12(J=1-0) IN GSH 287+04-17 AND GSH 277+00+36

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    We present parsec-scale resolution observations of the atomic and molecular ISM in two Galactic supershells, GSH 287+04–17 and GSH 277+00+36. Hi synthesis images from the Australia Telescope Compact Array are combined with 12CO(J=1–0) data from the NANTEN telescope to reveal substantial quantities of molecular gas closely associated with both shells. These data allow us to confirm an enhanced level of molecularization over the volumes of both objects, providing the first direct observational evidence of increased molecular cloud production due to the influence of supershells. We find that the atomic shell walls are dominated by cold gas with estimated temperatures and densities of T ∼ 100 K and n0 ∼ 10 cm−3. Locally, the shells show rich substructure in both tracers, with molecular gas seen elongated along the inner edges of the atomic walls, embedded within Hi filaments and clouds, or taking the form of small CO clouds at the tips of tapering atomic ‘fingers’. We discuss these structures in the context of different formation scenarios, suggesting that molecular gas embedded within shell walls is well explained by in-situ formation from the swept up medium, whereas CO seen at the ends of fingers of Hi may trace remnants of molecular clouds that pre-date the shells. A preliminary assessment of star formation activity within the shells confirms ongoing star formation in the molecular gas of both GSH 287+04–17 and GSH 277+00+36

    Endothelium-derived Hyperpolarizing Factor (EDHF) Mediates Endothelium-dependent Vasodilator Effects of Aqueous Extracts from Eucommia ulmoides Oliv. Leaves in Rat Mesenteric Resistance Arteries

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    The vascular effects of an aqueous extract prepared from the leaves of Eucommia ulmoides Oliv. (ELE), a medicinal herb commonly used in antihypertensive herbal prescriptions in China, were investigated in rat mesenteric resistance arteries. The mesenteric vascular bed was perfused with Krebs solution and the perfusion pressure was measured with a pressure transducer. In preparations with an intact endothelium and precontracted with 7&#956;M methoxamine, perfusion of ELE (10&#65293;7&#65293;10&#65293;2mg/ml for 15min) caused a concentration-dependent vasodilatation, which was abolished by chemical removal of the endothelium. The ELE-induced vasodilatation was inhibited by neither indomethacin (INDO, a cyclooxygenase inhibitor) nor NG-nitro-L-arginine-methyl ester (L-NAME, a nitric oxide inhibitor). The ELE-induced vasodilatation was significantly inhibited by tetraethylammonium (TEA, a K+ channel blocker) and 18&#945;-glycyrrhetinic acid (18&#945;-GA, a gap-junction inhibitor), and abolished by high K+ -containing Krebs&#700; solution. Atropine (a muscarinic acetylcholine receptor antagonist) significantly inhibited the vasodilatation induced by ELE at high concentrations. These results suggest that the ELE-induced vasodilatation is endothelium-dependent but nitric oxide (NO)- and prostaglandin I2 (PGI2)-independent, and is mainly mediated by the endothelium-derived hyperpolarizing factor (EDHF) in the mesenteric resistance arteries. Furthermore, the ELE-induced EDHF-mediated response involves the activation of K+-channels and gap junctions.</p

    Evaluating the Wind-Induced Mechanical Noise on the InSight Seismometers

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    The SEIS (Seismic Experiment for Interior Structures) instrument onboard the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. Here we analyse in-situ wind measurements from previous Mars space missions to understand the wind environment that we are likely to encounter on Mars, and then we use an elastic ground deformation model to evaluate the mechanical noise contributions on the SEIS instrument due to the interaction between the Martian winds and the InSight lander. Lander mechanical noise maps that will be used to select the best deployment site for SEIS once the InSight lander arrives on Mars are also presented. We find the lander mechanical noise may be a detectable signal on the InSight seismometers. However, for the baseline SEIS deployment position, the noise is expected to be below the total noise requirement > 97 % of the time and is, therefore, not expected to endanger the InSight mission objectives

    X-ray absorption spectroscopy and novel electronic properties in heavy fermion compounds YbT2Zn20 (T: Rh and Ir)

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    YbT2Zn20 (T: Rh and Ir), which crystallizes in the cubic CeCr2Al20-type structure, is a member of the well-known heavy fermion compounds, indicating a huge electronic specific heat coefficient γ ≊ 500 mJ/(K2centerdotmol). We have measured temperature and magnetic field dependences of Yb valence in YbT2Zn20(T: Rh and Ir) at ambient pressure by the Lm edge x- ray absorption spectroscopy in order to investigate the valence state of Yb 4f electrons in these compounds. It is revealed that the Yb valence in both compounds significantly decreases with temperature below about 100 K and increases with increasing magnetic field at low temperatures in contrast to the case of YbCo2Zn20.International Conference on Strongly Correlated Electron Systems 2014 (SCES2014), 7–14 July 2014, Grenoble, Franc

    Giant gate modulation of antiferromagnetic spin reversal by the magnetoelectric effect

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    Ujimoto K., Sameshima H., Toyoki K., et al. Giant gate modulation of antiferromagnetic spin reversal by the magnetoelectric effect. NPG Asia Materials 16, 20 (2024); https://doi.org/10.1038/s41427-024-00541-z.In this study, using the Pt/Cr2O3/Pt epitaxial trilayer, we demonstrate the giant voltage modulation of the antiferromagnetic spin reversal and the voltage-induced 180° switching of the Néel vector in maintaining a permanent magnetic field. We obtained a significant modulation efficiency of the switching field, Δμ0HSW/ΔV (Δμ0HSW/ΔE), reaching a maximum of −500 mT/V (−4.80 T nm/V); this value was more than 50 times greater than that of the ferromagnetic-based counterparts. From the temperature dependence of the modulation efficiency, X-ray magnetic circular dichroism measurements and first-principles calculations, we showed that the origin of the giant modulation efficiency relied on the electric field modulation of the net magnetization due to the magnetoelectric effect. From the first-principles calculation and the thickness effect on the offset electric field, we found that the interfacial magnetoelectric effect emerged. Our demonstration reveals the energy-efficient and widely applicable operation of an antiferromagnetic spin based on a mechanism distinct from magnetic anisotropy control
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