1,185 research outputs found
KINEMATICAL ANALYSIS OF 110M HURDLES - FOCUSING ON THE STEP LENGTH
The adaptations to each of the four steps are required for good performance in 110m hurdles (McDonald, 2002). However, the motions related with both running velocity and step length are not studied yet. Thus the purpose of this study was to investigate kinematic characteristics of 110m hurdlers with reference to step length
Gigantic Maximum of Nanoscale Noncontact Friction
We report measurements of noncontact friction between surfaces of NbSe
and SrTiO, and a sharp Pt-Ir tip that is oscillated laterally by a quartz
tuning fork cantilever. At 4.2 K, the friction coefficients on both the
metallic and insulating materials show a giant maximum at the tip-surface
distance of several nanometers. The maximum is strongly correlated with an
increase in the spring constant of the cantilever. These features can be
understood phenomenologically by a distance-dependent relaxation mechanism with
distributed time scales.Comment: 5 pages, 4 figure
Trends in antimicrobial-drug resistance in Japan.
Multidrug resistance in gram-positive bacteria has become common worldwide. In Japan until recently, gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella pneumoniae, and Serratia marcescens were controlled by carbapenems, fluoroquinolones, and aminoglycosides. However, several of these microorganisms have recently developed resistance against many antimicrobial drugs
High-pressure phase diagram of NdFeAsO0.9F0.1: Disappearance of superconductivity on the verge of ferromagnetism from Nd moments
We investigated transport and magnetic properties of single crystal NdFeAsO0.9F0.1 under hydrostatic pressures up to 50 GPa. The ambient pressure superconductivity at Tc ∼ 45.4 K was fully suppressed at Pc ∼ 21 GPa. Upon a further increase of pressure, ferromagnetism associated with the order of the rare-earth subsystem was induced at the border of superconductivity. Our finding is supported by the hysteresis in the magnetization M(H) loops and the strong increase in the field cooled data M(T ) toward low temperatures. We also show that the temperature evolution of the electrical resistivity as a function of pressure is consistent with a crossover from a Fermi liquid to non-Fermi liquid to Fermi liquid. The Hall measurements suggest that the multiband electronic structures have changed with pressure, which should also affect the resistivity behavior. These results give access to the high-pressure side of the superconducting phase diagram in the 1111 type of materials
Nonmagnetic-Defect-Induced Magnetism in Graphene
It is shown that a strong impurity potential induces short-range
antiferromagnetic (ferrimagnetic) order around itself in a Hubbard model on a
half-filled honeycomb lattice. This implies that short-range magnetic order is
induced in monolayer graphene by a nonmagnetic defect such as a vacancy with
full hydrogen termination or a chemisorption defect.Comment: 5 pages, 8 figure
Monitoring and predicting crop growth and analysing agricultural ecosystems by remote sensing
LANDSAT/TM data, which are characterized by high spectral/spatial resolutions, are able to contribute to practical agricultural management. In the first part of the paper, the authors review some recent applications of satellite remote sensing in agriculture. Techniques for crop discrimination and mapping have made such rapid progress that we can classify crop types with more than 80% accuracy. The estimation of crop biomass using satellite data, including leaf area, dry and fresh weights, and the prediction of grain yield, has been attempted using various spectral vegetation indices. Plant stresses caused by nutrient deficiency and water deficit have also been analysed successfully. Such information may be useful for farm management. In the latter half of the paper, we introduce the Arctic Science Project, which was carried out under the Science and Technology Agency of Japan collaborating with Finnish scientists. In this project, monitoring of the boreal forest was carried out using LANDSAT data. Changes in the phenology of subarctic ground vegetation, based on spectral properties, were measured by a boom-mounted, four-band spectroradiometer. The turning point dates of the seasonal near-infrared (NIR) and red (R) reflectance factors might indicate the end of growth and the beginning of autumnal tints, respectively
Promoter Sequences Prediction Using Relational Association Rule Mining
In this paper we are approaching, from a computational perspective, the problem of promoter sequences prediction, an important problem within the field of bioinformatics. As the conditions for a DNA sequence to function as a promoter are not known, machine learning based classification models are still developed to approach the problem of promoter identification in the DNA. We are proposing a classification model based on relational association rules mining. Relational association rules are a particular type of association rules and describe numerical orderings between attributes that commonly occur over a data set. Our classifier is based on the discovery of relational association rules for predicting if a DNA sequence contains or not a promoter region. An experimental evaluation of the proposed model and comparison with similar existing approaches is provided. The obtained results show that our classifier overperforms the existing techniques for identifying promoter sequences, confirming the potential of our proposal
Magnetic Properties in Non-centrosymmetric Superconductors with and without Antiferromagnetic Order
The paramagnetic properties in non-centrosymmetric superconductors with and
without antiferromagnetic (AFM) order are investigated with focus on the heavy
Fermion superconductors, CePt_3Si, CeRhSi_3 and CeIrSi_3. First, we investigate
the spin susceptibility in the linear response regime and elucidate the role of
AFM order. The spin susceptibility at T=0 is independent of the pairing
symmetry and increases in the AFM state. Second, the non-linear response to the
magnetic field are investigated on the basis of an effective model for CePt_3Si
which may be also applicable to CeRhSi_3 and CeIrSi_3. The role of
antisymmetric spin-orbit coupling (ASOC), helical superconductivity,
anisotropic Fermi surfaces and AFM order are examined in the dominantly s-, p-
and d-wave states. We emphasize the qualitatively important role of the mixing
of superconducting (SC) order parameters in the p-wave state which enhances the
spin susceptibility and suppresses paramagnetic depairing effect in a
significant way. Therefore, the dominantly p-wave superconductivity admixed
with the s-wave order parameter is consistent with the paramagnetic properties
of CePt_3Si at ambient pressure. We propose some experiments which can
elucidate the novel pairing states in CePt_3Si as well as CeRhSi_3 and
CeIrSi_3.Comment: To appear in J. Phys. Soc. Jpn. (2007) No.1
Role of the Subunits Interactions in the Conformational Transitions in Adult Human Hemoglobin: an Explicit Solvent Molecular Dynamics Study
Hemoglobin exhibits allosteric structural changes upon ligand binding due to
the dynamic interactions between the ligand binding sites, the amino acids
residues and some other solutes present under physiological conditions. In the
present study, the dynamical and quaternary structural changes occurring in two
unligated (deoxy-) T structures, and two fully ligated (oxy-) R, R2 structures
of adult human hemoglobin were investigated with molecular dynamics. It is
shown that, in the sub-microsecond time scale, there is no marked difference in
the global dynamics of the amino acids residues in both the oxy- and the deoxy-
forms of the individual structures. In addition, the R, R2 are relatively
stable and do not present quaternary conformational changes within the time
scale of our simulations while the T structure is dynamically more flexible and
exhibited the T\rightarrow R quaternary conformational transition, which is
propagated by the relative rotation of the residues at the {\alpha}1{\beta}2
and {\alpha}2{\beta}1 interface.Comment: Reprinted (adapted) with permission from J. Phys. Chem. B
DOI:10.1021/jp3022908. Copyright (2012) American Chemical Societ
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