2,622 research outputs found

    N-fold Supersymmetry in Quantum Mechanics - Analyses of Particular Models -

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    We investigate particular models which can be N-fold supersymmetric at specific values of a parameter in the Hamiltonians. The models to be investigated are a periodic potential and a parity-symmetric sextic triple-well potential. Through the quantitative analyses on the non-perturbative contributions to the spectra by the use of the valley method, we show how the characteristic features of N-fold supersymmetry which have been previously reported by the authors can be observed. We also clarify the difference between quasi-exactly solvable and quasi-perturbatively solvable case in view of the dynamical property, that is, dynamical N-fold supersymmetry breaking.Comment: 32 pages, 10 figures, REVTeX

    First Meeting of the joint IOC-ICES Study Group on Nutrient Standards (SGONS)

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    A meeting of the joint IOC-ICES Study Group on Nutrient Standards (SGONS) was held in Paris, France on 23-24 March 2010. It focused on the ongoing activities of the SGONS and plans for extended international collaborations to establish global comparability of the nutrient data from the world’s ocean. Thirty two scientists and experts from 11 countries and 2 delegates from IOC attended the meeting. The discussions followed the Terms of References of SGONS established in July 2009. Development of the reference materials for nutrients in seawater (RMNS) were also discussed in collaboration with the producers. The background and history of SGONS and an international nutrients scale system INSS and the progress with the production of RMNS materials and their current availability were reported. The production of RMNS and the latest status of the RMNS production facility, current status on the certification of RMNS for nitrate, nitrite, phosphate and silicate at the National Metrology Institute of Japan were also reported. The revised nutrients analysis manual which is being undertaken by the SGONS hopefully would be completed by 1 August 2010, and it will be published on line at the Go-Ship website. Results obtained with RMNS solutions used on the P6 reoccupation cruise in 2009-2010 by SIO (Scripps Institute of Oceanography, USA) showed that considerable improvement could be made in the internal comparability of the data by referencing it to the RMNS results and related good comparability with the previous P6 cruise in 2003 by JAMSTEC when RMNS were also used. The meeting strongly endorsed the idea of a ship board workshop in 2013/14 during which major groups would carry out a full inter-comparison of all procedures including analytical methods on board a research ship. The global stability test of RMNS by ten core laboratories of SGONS which started in 2009 will continue for more two years. It also was agreed to set up an international steering committee to plan the next inter-laboratory comparison study which will extend the study to about 70 laboratories working globally on deep sea hydrography. This will happen in early 2011. Future arrangements were considered for the collection of more batches of seawater for the preparation of RMNS waters suitable for use in all major water masses, and a list of candidate cruises in 2010/2011 was prepared. The related point of the extension of the use of RMNS for work in shelf sea water was also discussed, this followed on from discussions at the ICES Marine Chemistry Working Group (MCWG) meeting in 2010. The ICES MCWG considered that the use of suitable RMNS solutions would be valuable for improving the inter comparability of shelf sea data and be a valuable complement to work with the existing QUASIMEME proficiency testing scheme

    Testing new physics with the electron g-2

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    We argue that the anomalous magnetic moment of the electron (a_e) can be used to probe new physics. We show that the present bound on new-physics contributions to a_e is 8*10^-13, but the sensitivity can be improved by about an order of magnitude with new measurements of a_e and more refined determinations of alpha in atomic-physics experiments. Tests on new-physics effects in a_e can play a crucial role in the interpretation of the observed discrepancy in the anomalous magnetic moment of the muon (a_mu). In a large class of models, new contributions to magnetic moments scale with the square of lepton masses and thus the anomaly in a_mu suggests a new-physics effect in a_e of (0.7 +- 0.2)*10^-13. We also present examples of new-physics theories in which this scaling is violated and larger effects in a_e are expected. In such models the value of a_e is correlated with specific predictions for processes with violation of lepton number or lepton universality, and with the electric dipole moment of the electron.Comment: 34 pages, 7 figures. Minor changes and references adde

    Impaired glycolytic metabolism causes chondrocyte hypertrophy-like changes via promotion of phospho-Smad1/5/8 translocation into nucleus

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    SummaryObjectiveHypertrophy-like changes are often observed in chondrocytes during the development of osteoarthritis (OA). These changes play a crucial part in the OA-associated cartilage degradation and osteophyte formation. However, the pathogenesis leading to such changes is still unknown. In this study, we investigated the mechanism by which these hypertrophy-like changes are induced from the viewpoint of impaired glycolytic metabolism.MethodsThe effect of sodium fluoride (NaF) on glycolytic metabolism of cultured chondrocytes was confirmed by measurement of intracellular adenosine triphosphate (ATP) production. Translocation of phosphorylated Smad1/5/8 to the nucleus was evaluated by subcellular fractionation and Western blotting. Chondrocyte hypertrophy-like changes were investigated by real-time RT-PCR and Western blot analysis of differentiation markers.ResultsATP production was dose-dependently decreased by NaF in the human chondrocytic cell line HCS-2/8. In addition, both chondrocyte proliferation and differentiation were inhibited, whereas cell death was promoted by treatment with NaF. Interestingly, combinational treatment with NaF and lactate enhanced translocation of phospho-Smad1/5/8 to the nucleus, as well as gene expression of ALP, VEGF, COL10a1, and matrix metalloproteinase13 (MMP13), which were the markers of late mature and hypertrophic chondrocytes. Furthermore, the production of type X collagen and activation of MMP9 were also promoted under the same conditions.ConclusionsThese findings suggest that decreased ATP production by NaF promotes hypertrophy-like changes via activation of phospho-Smad1/5/8 in the presence of lactate. Novel metabolic aspects of OA pathogenesis are indicated herein

    Dipole excited states in 11^{11}Li with complex scaling

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    The 1^- excitations of the three--body halo nucleus 11^{11}Li are investigated. We use adiabatic hyperspherical expansion and solve the Faddeev equations in coordinate space. The method of complex scaling is used to compute the resonance states. The Pauli forbidden states occupied by core neutrons are excluded by constructing corresponding complex scaled phase equivalent two-body potentials. We use a recently derived neutron--core interaction consistent with known structure and reaction properties of 10^{10}Li and 11^{11}Li. The computed dipole excited states with Jπ=1/2+J^\pi=1/2^+, Jπ=3/2+J^\pi=3/2^+, and Jπ=5/2+J^\pi=5/2^+ have energies ranging from 0.6 MeV to 1.0 MeV and widths between 0.15 MeV and 0.65 MeV. We investigate the dependence of the complex energies of these states on the 10^{10}Li spectrum. The finite spin 3/2 of the core and the resulting core-neutron spin-spin interaction are important. The connection with Coulomb dissociation experiments is discussed and a need for better measurements is pointed out.Comment: 28 pages, 6 figures, Nuclear Physics A, in pres

    Origin of Borromean systems

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    The complex energies of the three-body resonances for one infinitely heavy particle and two non-interacting light particles are the sum of the two contributing two-body complex resonance energies. The bound state of a Borromean system originates from a resonance when the third interaction is introduced, a finite mass is allowed and proper angular momentum coupling is included. The relative importance of these contributions are investigated and the resulting structure of Borromean systems are traced back to the two-body continuum properties. The 0+0^+ and 2+2^+ states in 6^{6}He result from neutron-core p-states and the ground and first excited state of 11^{11}Li originate from neutron-core s2s^2 and spsp-states.Comment: Physics Letters B, in pres

    Inhomogeneous superconducting states of mesoscopic thin-walled cylinders in external magnetic fields

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    We theoretically investigate the appearance of spatially modulated superconducting states in mesoscopic superconducting thin-wall cylinders in a magnetic field at low temperatures. Quantization of the electron motion around the circumference of the cylinder leads to a discontinuous evolution of the spatial modulation of the superconducting order parameter along the transition line Tc(H). We show that this discontinuity leads to the nonmonotonic behavior of the specific heat jump at the onset of superconductivity as a function of temperature and field. We argue that this geometry provides an excellent opportunity to directly and unambiguously detect distinctive signatures of the Fulde-Ferrell-Larkin-Ovchinnikov modulation of the superconducting order. © 2013 American Physical Society

    Primary palliative care in Japan: needs estimation and projections – national database study with international comparisons

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    Objectives We aimed to estimate the potential population that requires palliative care, clarify the relationship between this population and the rate of ageing in Japan, and compare these trends with those of other countries.Design We used the national death registration data and population projections for Japan to estimate the population in need of palliative care using the minimal estimate method developed by Murtagh et al. Linear regression was used to create a model of mortality using sex, age at intervals of 5 years, and each major disease classification. We calculated the future population in need of palliative care until 2040 and compared the ageing data to those of other countries.Setting/participants All adults in Japan who died from 1980 to 2040 at intervals of 5 years.Results The number of people who might need palliative care from 2020 to 2040 will also increase linearly from 1 059 000 to 1 405 000. The proportion of Alzheimer’s, dementia and senility of the total need for palliative care will increase to 43.4% in 2040. The correlation coefficient between the proportion of the population in need of palliative care and the rate of ageing was 0.24 in developed countries.Conclusion In Japan, the population requiring palliative care in 2040 will be 1.5 times that in 2015. Palliative care needs to be provided urgently for people with Alzheimer’s disease, dementia and senility. The proportion of patients in need of palliative care may not change, although the number of patients requiring such gradually increases in developed countries

    Superconformal mechanics and nonlinear supersymmetry

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    We show that a simple change of the classical boson-fermion coupling constant, 2α2αn2\alpha \to 2\alpha n , nNn\in \N, in the superconformal mechanics model gives rise to a radical change of a symmetry: the modified classical and quantum systems are characterized by the nonlinear superconformal symmetry. It is generated by the four bosonic integrals which form the so(1,2) x u(1) subalgebra, and by the 2(n+1) fermionic integrals constituting the two spin-n/2 so(1,2)-representations and anticommuting for the order n polynomials of the even generators. We find that the modified quantum system with an integer value of the parameter α\alpha is described simultaneously by the two nonlinear superconformal symmetries of the orders relatively shifted in odd number. For the original quantum model with α=p|\alpha|=p, pNp\in \N, this means the presence of the order 2p nonlinear superconformal symmetry in addition to the osp(2|2) supersymmetry.Comment: 16 pages; misprints corrected, note and ref added, to appear in JHE

    Algebraic Model for scattering of three-s-cluster systems. II. Resonances in the three-cluster continuum of 6He and 6Be

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    The resonance states embedded in the three-cluster continuum of 6He and 6Be are obtained in the Algebraic Version of the Resonating Group Method. The model accounts for a correct treatment of the Pauli principle. It also provides the correct three-cluster continuum boundary conditions by using a Hyperspherical Harmonics basis. The model reproduces the observed resonances well and achieves good agreement with other models. A better understanding for the process of formation and decay of the resonance states in six-nucleon systems is obtained.Comment: 8 pages, 10 postscript figures, submitted to Phys. Rev.
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