63,353 research outputs found

    Diffusion in a continuum model of self-propelled particles with alignment interaction

    Get PDF
    In this paper, we provide the O(ϵ)O(\epsilon) corrections to the hydrodynamic model derived by Degond and Motsch from a kinetic version of the model by Vicsek & coauthors describing flocking biological agents. The parameter ϵ\epsilon stands for the ratio of the microscopic to the macroscopic scales. The O(ϵ)O(\epsilon) corrected model involves diffusion terms in both the mass and velocity equations as well as terms which are quadratic functions of the first order derivatives of the density and velocity. The derivation method is based on the standard Chapman-Enskog theory, but is significantly more complex than usual due to both the non-isotropy of the fluid and the lack of momentum conservation

    Estimates of isospin breaking contributions to baryon masses

    Full text link
    We estimate the isospin breaking contributions to the baryon masses which we analyzed recently using a loop expansion in the heavy baryon approximation to chiral effective field theory. To one loop, the isospin breaking corrections come from the effects of the d,ud, u quark mass difference, the Coulomb and magnetic moment interactions, and effective point interactions attributable to color-magnetic effects. The addition of the first meson loop corrections introduces new structure. We estimate the resulting low-energy, long-range contributions to the mass splittings by regularizing the loop integrals using connections to dynamical models for finite-size baryons. We find that the resulting contributions to the isospin breaking corrections are of the right general size, have the correct sign pattern, and agree with the experimental values within the margin of error.Comment: 15 pages, 5 figures; changed title and conten

    One parameter family of indecomposable optimal entanglement witnesses arising from generalized Choi maps

    Full text link
    In the recent paper [Chru\'{s}ci\'{n}ski and Wudarski, arXiv:1105.4821], it was conjectured that the entanglement witnesses arising from some generalized Choi maps are optimal. We show that this conjecture is true. Furthermore, we show that they provide a one parameter family of indecomposable optimal entanglement witnesses.Comment: 3 page

    Bloch-mode analysis for retrieving effective parameters of metamaterials

    Get PDF
    We introduce a new approach for retrieving effective parameters of metamaterials based on the Bloch-mode analysis of quasi-periodic composite structures. We demonstrate that, in the case of single-mode propagation, a complex effective refractive index can be assigned to the structure, being restored by our method with a high accuracy. We employ both surface and volume averaging of the electromagnetic fields of the dominating (fundamental) Bloch modes to determine the Bloch and wave impedances, respectively. We discuss how this method works for several characteristic examples, and demonstrate that this approach can be useful for retrieval of both material and wave effective parameters of a broad range of metamaterials.Comment: 12 pages, 10 figure

    Biochemical Properties of a Decoy Oligodeoxynucleotide Inhibitor of STAT3 Transcription Factor.

    Get PDF
    Cyclic STAT3 decoy (CS3D) is a second-generation, double-stranded oligodeoxynucleotide (ODN) that mimics a genomic response element for signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. CS3D competitively inhibits STAT3 binding to target gene promoters, resulting in decreased expression of proteins that promote cellular proliferation and survival. Previous studies have demonstrated antitumor activity of CS3D in preclinical models of solid tumors. However, prior to entering human clinical trials, the efficiency of generating the CS3D molecule and its stability in biological fluids should be determined. CS3D is synthesized as a single-stranded ODN and must have its free ends ligated to generate the final cyclic form. In this study, we report a ligation efficiency of nearly 95 percent. The ligated CS3D demonstrated a half-life of 7.9 h in human serum, indicating adequate stability for intravenous delivery. These results provide requisite biochemical characterization of CS3D that will inform upcoming clinical trials

    Spin-Charge Separation at Finite Temperature in the Supersymmetric t-J Model with Long-Range Interactions

    Full text link
    Thermodynamics is derived rigorously for the 1D supersymmetric {\it t-J} model and its SU(K,1K,1) generalization with inverse-square exchange. The system at low temperature is described in terms of spinons, antispinons, holons and antiholons obeying fractional statistics. They are all free and make the spin susceptibility independent of electron density, and the charge susceptibility independent of magnetization. Thermal spin excitations responsible for the entropy of the SU(K,1K,1) model are ascribed to free para-fermions of order K1K-1.Comment: 10 pages, REVTE

    PENGETAHUAN KADER TENTANG PROSES MENUA DENGAN KEAKTIFAN KADER PADA PELAKSANAAN POSBINDU DI KELURAH SENDANGMULYO KECAMATAN TEMBALANG SEMARANG

    Get PDF
    Dari survai pendahuluan pada Posbindu di Kelurahan Sendangmulyo Kecamatan Tembalang Kota Semarang ada 17 Posbindu yang aktif dengan jumlah kader sebanyak 86 orang dan ada beberapa kader masuk kategori tidak aktif. Keaktifan kader diduga berkaitan dengan pengetahuannya tentang proses menua. Tujuan penelitian untuk mengetahui hubungan pengetahuan kader tentang proses menua dengan keaktifan kader pada pelaksanaan Posbindu di Kelurahan Sendangmulyo Kecamatan Tembalang Kota Semarang. Jenis penelitian ini adalah descriptive correlatif dengan pendekatan cross sectional. Teknik sampel menggunakan Total Sampling, sehingga 86 responden. Analisis datamenggunakan Korelasi Person Product Moment karena data berdistribusi normal. Hasil: rata-rata umur kader 41 tahun, perempuan (100%), SMA (62,8%), ibu rumah tangga (77,9%). Sebagian besar kader pengetahuan baik (98,8%), kader aktif (65,1%). Tidak ada hubungan antara pengetahuan kader dengan keaktifan kader di Kelurahan Sendangmulyo Kecamatan Tembalang Kota Semarang dengan p value 0,229 ( >0.05) .Kata Kunci : Pengetahuan, Keaktifan dan Kade

    Singular Cucker-Smale Dynamics

    Full text link
    The existing state of the art for singular models of flocking is overviewed, starting from microscopic model of Cucker and Smale with singular communication weight, through its mesoscopic mean-filed limit, up to the corresponding macroscopic regime. For the microscopic Cucker-Smale (CS) model, the collision-avoidance phenomenon is discussed, also in the presence of bonding forces and the decentralized control. For the kinetic mean-field model, the existence of global-in-time measure-valued solutions, with a special emphasis on a weak atomic uniqueness of solutions is sketched. Ultimately, for the macroscopic singular model, the summary of the existence results for the Euler-type alignment system is provided, including existence of strong solutions on one-dimensional torus, and the extension of this result to higher dimensions upon restriction on the smallness of initial data. Additionally, the pressureless Navier-Stokes-type system corresponding to particular choice of alignment kernel is presented, and compared - analytically and numerically - to the porous medium equation
    corecore