555 research outputs found

    Angle dependence of the orbital magnetoresistance in bismuth

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    We present an extensive study of angle-dependent transverse magnetoresistance in bismuth, with a magnetic field perpendicular to the applied electric current and rotating in three distinct crystallographic planes. The observed angular oscillations are confronted with the expectations of semi-classic transport theory for a multi-valley system with anisotropic mobility and the agreement allows us to quantify the components of the mobility tensor for both electrons and holes. A quadratic temperature dependence is resolved. As Hartman argued long ago, this indicates that inelastic resistivity in bismuth is dominated by carrier-carrier scattering. At low temperature and high magnetic field, the threefold symmetry of the lattice is suddenly lost. Specifically, a 2π/32\pi/3 rotation of magnetic field around the trigonal axis modifies the amplitude of the magneto-resistance below a field-dependent temperature. By following the evolution of this anomaly as a function of temperature and magnetic field, we mapped the boundary in the (field, temperature) plane separating two electronic states. In the less-symmetric state, confined to low temperature and high magnetic field, the three Dirac valleys cease to be rotationally invariant. We discuss the possible origins of this spontaneous valley polarization, including a valley-nematic scenario.Comment: 15 pages, 14 figure

    Reconstruction of Inclusions for the Inverse Boundary Value Problem of Non-stationary Heat Equation

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    An inverse problem for identifying an inclusion inside an isotropic, homogeneous heat conductive medium is considered. The shape of inclusion can change depending on time. For the one space dimensional case, we developed an analogue of the probe method known for inverse boundary value problems for elliptic equations and gave the reconstruction procedure for identifying the inclusion from the Neumann to Dirichlet map

    Workplace reform with changing management through the user participation workshop : the case study of Seiyo City Office / Ikumi Egawa

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    The research explains about workplace reform, aimed at improving productivity of General Affairs and Policy Planning department of Seiyo officeby changing management through the user participation workshop at 4th floor of Seiyo city office and on the changes of workplace reform. The purpose of this research is to find the changes that are worker's behaviour and worker’s awareness of workplace through workplace reform. The researchers surveyed changes, worker's behaviour and worker's awareness of workplace using workplace reform at 4th floor of Seiyo office as case study. In workplace reform, in order to create a place where new work style can be practiced, the researchers conducted the user participation workshops with workers a total of 6 times. Through the workshops, concept of work style and plan of renovation were proposed. In addition, the researchers did a survey using two methods which were a set of questionnaire and 3 observationsthat is before the workplace renovation, 3 months after the renovation, and 1 year and 3 months after the renovation. The findings obtained from the questionnaire in the first three months after the renovation showed that the opinions of the workers were divided between pros and cons against workplace reform. However, the survey of 1 year and three months after the renovation showed that almost all workers are satisfied with the new environment. In addition, the researchers found that a positive correlation exist between participation rate of workshops and the satisfaction level. The findings suggest the worth of workshops for workplace reform. In the Observation Survey, the workers needed to select a place freely where they can work comfortably after the workplace reform. For example, they chose to work in refresh space. In addition, the findings from the survey showed that the floor became livelier when the participation rate increses at that workplace. Additionally, the participants became more conscious of the work style such as features of work style, after workplace renovation; they are able to clearly differentiate between short intermittent works separated by conversation and phone and personal work on concentration

    The Possible Role of TASK Channels in Rank-Ordered Recruitment of Motoneurons in the Dorsolateral Part of the Trigeminal Motor Nucleus.

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    Because a rank-ordered recruitment of motor units occurs during isometric contraction of jaw-closing muscles, jaw-closing motoneurons (MNs) may be recruited in a manner dependent on their soma sizes or input resistances (IRs). In the dorsolateral part of the trigeminal motor nucleus (dl-TMN) in rats, MNs abundantly express TWIK (two-pore domain weak inwardly rectifying K channel)-related acid-sensitive-K(+) channel (TASK)-1 and TASK3 channels, which determine the IR and resting membrane potential. Here we examined how TASK channels are involved in IR-dependent activation/recruitment of MNs in the rat dl-TMN by using multiple methods. The real-time PCR study revealed that single large MNs (>35 μm) expressed TASK1 and TASK3 mRNAs more abundantly compared with single small MNs (15-20 μm). The immunohistochemistry revealed that TASK1 and TASK3 channels were complementarily distributed in somata and dendrites of MNs, respectively. The density of TASK1 channels seemed to increase with a decrease in soma diameter while there were inverse relationships between the soma size of MNs and IR, resting membrane potential, or spike threshold. Dual whole-cell recordings obtained from smaller and larger MNs revealed that the recruitment of MNs depends on their IRs in response to repetitive stimulation of the presumed Ia afferents. 8-Bromoguanosine-cGMP decreased IRs in small MNs, while it hardly changed those in large MNs, and subsequently decreased the difference in spike-onset latency between the smaller and larger MNs, causing a synchronous activation of MNs. These results suggest that TASK channels play critical roles in rank-ordered recruitment of MNs in the dl-TMN

    Skipping of an alternative intron in the srsf1 3' untranslated region increases transcript stability

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    The srsf1 gene encodes serine/arginine-rich splicing factor 1 (SRSF1) that participates in both constitutive and alternative splicing reactions. This gene possesses two ultraconserved elements in the 3’ untranslated region (UTR). Skipping of an alternative intron between the two elements has no effect on the protein-coding sequence, but it generates a premature stop codon (PTC)-containing mRNA isoform, whose degradation is considered to depend on nonsense-mediated mRNA decay (NMD). However, several cell lines (HCT116, RKO, HeLa, and WI38 cells) constitutively expressed significant amounts of the srsf1 PTC variant. HCT116 cells expressed the PTC variant nearly equivalent to the major isoform that includes the alternative intron in the 3’ UTR. Inhibition of NMD by silencing a key effecter UPF1 or by treatment with cycloheximide failed to increase amounts of the PTC variant in HCT116 cells, and the PTC variant was rather more stable than the major isoform in the presence of actinomycin D. Our results suggest that the original stop codon may escape from the NMD surveillance even in skipping of the alternative intron. The srsf1 gene may produce an alternative splice variant having truncated 3’ UTR to relief the microRNA- and/or RNA-binding protein-mediated control of translation or degradation

    Subarachnoid Hemorrhage Misdiagnosed as an Acute ST Elevation Myocardial Infarction

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    Without significant coronary artery stenosis, ischemic electrocardiographic change including ST segment elevation, segmental wall motion abnormality and elevated serum cardiac-specific markers (creatine kinase-MB, Troponin-T) may develop after central nervous system injuries such as subarachnoid, intracranial or subdural hemorrhage. Misdiagnosing these patients as acute myocardial infarction may result in catastrophic outcomes. By reporting a case of a 55-year old female with subarachnoid hemorrhage mimicking acute ST elevation myocardial infarction, we hope to underline that careful attention of neurologic abnormality is critical in making better prognosis

    Nuclear magnetic relaxation and superfluid density in Fe-pnictide superconductors: An anisotropic \pm s-wave scenario

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    We discuss the nuclear magnetic relaxation rate and the superfluid density with the use of the effective five-band model by Kuroki et al. [Phys. Rev. Lett. 101, 087004 (2008)] in Fe-based superconductors. We show that a fully-gapped anisotropic \pm s-wave superconductivity consistently explains experimental observations. In our phenomenological model, the gaps are assumed to be anisotropic on the electron-like \beta Fermi surfaces around the M point, where the maximum of the anisotropic gap is about four times larger than the minimum.Comment: 10 pages, 8 figures; Submitted versio
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