282 research outputs found

    Overexpression of an activated REL mutant enhances the transformed state of the human B-lymphoma BJAB cell line and alters its gene expression profile

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    The human REL proto-oncogene encodes a transcription factor in the nuclear factor (NF)-kappaB family. Overexpression of REL is acutely transforming in chicken lymphoid cells, but has not been shown to transform any mammalian lymphoid cell type. In this report, we show that overexpression of a highly transforming mutant of REL (RELDeltaTAD1) increases the oncogenic properties of the human B-cell lymphoma BJAB cell line, as shown by increased colony formation in soft agar, tumor formation in SCID (severe combined immunodeficient) mice, and adhesion. BJAB-RELDeltaTAD1 cells also show decreased activation of caspase in response to doxorubicin. BJAB-RELDeltaTAD1 cells have increased levels of active nuclear REL protein as determined by immunofluorescence, subcellular fractionation and electrophoretic mobility shift assay. Overexpression of RELDeltaTAD1 in BJAB cells has transformed the gene expression profile of BJAB cells from that of a germinal center B-cell subtype of diffuse large B-cell lymphoma (DLBCL) (GCB-DLBCL) to that of an activated B-cell subtype (ABC-DLBCL), as evidenced by increased expression of many ABC-defining mRNAs. Upregulated genes in BJAB-RELDeltaTAD1 cells include several NF-kappaB targets that encode proteins previously implicated in B-cell development or oncogenesis, including BCL2, IRF4, CD40 and VCAM1. The cell system we describe here may be valuable for further characterizing the molecular details of REL-induced lymphoma in humans.P42 ES007381 - NIEHS NIH HHS; R01 CA047763 - NCI NIH HHS; CA047763 - NCI NIH HHS; R01 CA047763-20 - NCI NIH HHS; P42 ES007381-140019 - NIEHS NIH HHS; 5 P42 ES07381 - NIEHS NIH HHS; P42 ES007381-150019 - NIEHS NIH HHS; R01 CA047763-19 - NCI NIH HH

    Use of control to maintain period-1 motions during wind-up or wind-down operations of an impacting driven beam

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    We consider the dynamical response of a thin beam held fixed at one end while excited by an external driving force. A motion limiting constraint, or stop, causes the beam to impact. During wind-up or wind-down operations, in which the driving frequency is continuously altered, the system can undergo complicated motions close to the value of frequency at which impacts may first occur, the grazing bifurcation. In this region, the beam may experience several impacts within a long period-repeating solution or even chaotic behavior which, in practical terms, may be undesirable to the long-term integrity of the system. The first task is to identify the zones in the space of parameters (forcing amplitude or, alternatively, the gap between the beam and the stop) in which period-1 motions can be guaranteed. In this paper, in the areas in which complicated or chaotic motion occurs, a control strategy is proposed which stabilises unstable period-1 motions. As a consequence, numerical simulations indicate that, for any choice of parameter in the range, simple period-1 motions can be maintained, limiting the number of impacts (together with their velocity)

    Autler-Townes splitting in two-color photoassociation of 6Li

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    We report on high-resolution two-color photoassociation spectroscopy in the triplet system of magneto-optically trapped 6Li. The absolute transition frequencies have been measured. Strong optical coupling of the bound molecular states has been observed as Autler-Townes splitting in the photoassociation signal. The spontaneous bound-bound transition rate is determined and the molecule formation rate is estimated. The observed lineshapes are in good agreement with the theoretical model.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev. A (Rapid Communication

    Simulation of Flow of Mixtures Through Anisotropic Porous Media using a Lattice Boltzmann Model

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    We propose a description for transient penetration simulations of miscible and immiscible fluid mixtures into anisotropic porous media, using the lattice Boltzmann (LB) method. Our model incorporates hydrodynamic flow, diffusion, surface tension, and the possibility for global and local viscosity variations to consider various types of hardening fluids. The miscible mixture consists of two fluids, one governed by the hydrodynamic equations and one by diffusion equations. We validate our model on standard problems like Poiseuille flow, the collision of a drop with an impermeable, hydrophobic interface and the deformation of the fluid due to surface tension forces. To demonstrate the applicability to complex geometries, we simulate the invasion process of mixtures into wood spruce samples.Comment: Submitted to EPJ

    The pressure of hot QCD up to g^6 ln(1/g)

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    The free energy density, or pressure, of QCD has at high temperatures an expansion in the coupling constant g, known so far up to order g^5. We compute here the last contribution which can be determined perturbatively, g^6 ln(1/g), by summing together results for the 4-loop vacuum energy densities of two different three-dimensional effective field theories. We also demonstrate that the inclusion of the new perturbative g^6 ln(1/g) terms, once they are summed together with the so far unknown perturbative and non-perturbative g^6 terms, could potentially extend the applicability of the coupling constant series down to surprisingly low temperatures.Comment: 18 pages. Small clarifications added. To appear in Phys.Rev.

    Structural and dynamical properties of superfluid helium: a density functional approach

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    We present a novel density functional for liquid 4He, properly accounting for the static response function and the phonon-roton dispersion in the uniform liquid. The functional is used to study both structural and dynamical properties of superfluid helium in various geometries. The equilibrium properties of the free surface, droplets and films at zero temperature are calculated. Our predictions agree closely to the results of ab initio Monte Carlo calculations, when available. The introduction of a phenomenological velocity dependent interaction, which accounts for backflow effects, is discussed. The spectrum of the elementary excitations of the free surface and films is studied.Comment: 37 pages, REVTeX 3.0, figures on request at [email protected]

    Modern topics in theoretical nuclear physics

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    Over the past five years there have been profound advances in nuclear physics based on effective field theory and the renormalization group. In this brief, we summarize these advances and discuss how they impact our understanding of nuclear systems and experiments that seek to unravel their unknowns. We discuss future opportunities and focus on modern topics in low-energy nuclear physics, with special attention to the strong connections to many-body atomic and condensed matter physics, as well as to astrophysics. This makes it an exciting era for nuclear physics.Comment: 8 pages, 1 figure, prepared for the Nuclear Physics Town Hall Meeting at TRIUMF, Sept. 9-10, 2005, comments welcome, references adde

    Regulatory T cells are paramount effectors in progesterone regulation of embryo implantation and fetal growth

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    Published: June 8, 2023Progesterone (P4) is essential for embryo implantation, but the extent to which the pro-gestational effects of P4 depend on the maternal immune compartment is unknown. Here, we investigate whether regulatory T cells (Treg cells) act to mediate luteal phase P4 effects on uterine receptivity in mice. P4 antagonist RU486 administered to mice on days 0.5 and 2.5 post coitum (dpc) to model luteal phase P4 deficiency caused fewer CD4+Foxp3+ Treg cells and impaired Treg functional competence, along with dysfunctional uterine vascular remodeling and perturbed placental development in mid-gestation. These effects were linked with fetal loss and fetal growth restriction, accompanied by a Th1/CD8-skewed T cell profile. Adoptive transfer at implantation of Treg cells - but not T conventional (Tconv) cells - alleviated fetal loss and fetal growth restriction by mitigating adverse effects of reduced P4 signaling on uterine blood vessel remodeling and placental structure, and restoring maternal T cell imbalance. These findings demonstrate an essential role for Treg cells in mediating P4 effects at implantation, and indicate that Treg cells are a sensitive and critical effector mechanism through which P4 drives uterine receptivity to support robust placental development and fetal growth.Ella S. Green, Lachlan M. Moldenhauer, Holly M. Groome, David J. Sharkey, Peck Y. Chin, Alison S. Care, Rebecca L. Robker, Shaun R. McColl, and Sarah A., Robertso

    N-body simulations of gravitational dynamics

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    We describe the astrophysical and numerical basis of N-body simulations, both of collisional stellar systems (dense star clusters and galactic centres) and collisionless stellar dynamics (galaxies and large-scale structure). We explain and discuss the state-of-the-art algorithms used for these quite different regimes, attempt to give a fair critique, and point out possible directions of future improvement and development. We briefly touch upon the history of N-body simulations and their most important results.Comment: invited review (28 pages), to appear in European Physics Journal Plu
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