Inconsistent phylogeographic pattern between a sperm dependent fish and its host: in situ hybridization vs dispersal

Characteristics of the different sampled sites. List of sampled sites with their geographical coordinates and biotypes composition. E, N and H respectively refer to Chrosomus eos, C. neogaeus and the hybrids. Hybrid lineages of each site are identified. (PDF 73 kb

Symmetries of Lagrangian fibrations

We construct fiber-preserving anti-symplectic involutions for a large class of symplectic manifolds with Lagrangian torus fibrations. In particular, we treat the K3 surface and the quintic threefold. We interpret our results as corroboration of the view that in homological mirror symmetry, an anti-symplectic involution is the mirror of duality. In the same setting, we construct fiber-preserving symplectomorphisms that can be interpreted as the mirror to twisting by a holomorphic line bundle.Comment: 45 page

Cell-cell interactions in synovitis: Interactions between T lymphocytes and synovial cells

Mechanisms whereby T lymphocytes contribute to synovial inflammation in rheumatoid arthritis are poorly understood. Here we review data that indicate an important role for cell contact between synovial T cells, adjacent macrophages and fibroblast-like synoviocytes (FLS). Thus, T cells activated by cytokines, endothelial transmigration, extracellular matrix or by auto-antigens can promote cytokine, particularly TNFα, metalloproteinase production by macrophages and FLS through cell-membrane interactions, mediated at least through β-integrins and membrane cytokines. Since soluble factors thus induced may in turn contribute directly to T cell activation, positive feedback loops are likely to be created. These novel pathways represent exciting potential therapeutic targets

Role of interleukin-15 and nitric oxide expression in chronic inflammatory disease

Interleukin-15 (IL-15) is a pleiotropic cytokine produced by macrophages and fibroblasts, which mediates biological activities primarily through binding to the beta and gamma components of the IL-2 receptor, together with its own unique a chain. IL-15 induces T cell migration and activation, NK cell activation, B cell maturation and antibody production and monocyte activation. IL-15 mRNA is widely expressed in both immune and non-immune tissues and cells lines. However, the role of IL-15 in the context of any pathological situation remains unclear. Therefore, the role of IL-15 in a T helper-1 (Th1) disease prototype, rheumatoid arthritis (RA), and a Th2 disease prototype, asthma, was investigated in the present study. IL-15 was identified in RA synovial fluids. Following IL-15-mediated activation, peripheral blood (PB) T cells were capable of inducing TNF-alpha production from a macrophage cell line, from syngeneic PB monocytes, and from synovial macrophage / synoviocyte co-cultures, through a cell-contact dependent mechanism which required no T cell cytokine synthesis. RA synovial fluid (SF) T cells exhibited similar properties, which were IL-15-dependent in vitro. IL-15 up-regulated CD69 expression on CD45RO+ T cells and neutralisation studies determined that such CD69 expression, in combination with LFA-1 and ICAM-1, was partly responsible for cell- contact mediated macrophage activation by T cells. Furthermore, a similar mechanism operated in regulating cell-contact-induced IL-15 production by monocytes. Thus, activated T cells appeared to be effective costimulators of TNF-alpha and IL-15 production by monocytes via cell-cell contact, thereby generating a positive feedback loop. IL-15 also modulated cytokine production and adhesion molecule expression by RA neutrophils. Finally, in a murine model, IL-15 blockade profoundly suppressed the development of collagen-induced arthritis (CIA). This was accompanied in vitro by marked reductions in antigen-specific proliferation and interferon-gamma (IFN-y) synthesis by spleen cells from treated compared with control mice and in vivo by 4 significant reduction in serum anti-collagen antibody levels. Taken together, these data clearly demonstrated an important role for IL-15 in the development of inflammatory arthritis. Parallel studies established that epithelial cells and inflammatory leukocytes from the respiratory tract of asthma patients expressed IL-15. Moreover, such cells also expressed high levels of inducible nitric oxide synthase and produced NO in vitro. Expression of both IL-15 and iNOS was significantly suppressed in patients receiving inhaled corticosteroid therapy. In vitro studies demonstrated synergistic upregulation of TNF-alpha by IL-15 and NO providing evidence for interactions between radical inflammatory mediators and cytokines in chronic inflammatory responses

Urotensin II and the Circulatory System

Urotensin II (UII), first isolated from the spinal cord of teleost fish, is the most potent vasoconstrictor known. It is more potent than endothelin-1 and acts through UT-II, a seven-transmembrane-domain, G-protein-coupled receptor. Human UII is an 11-amino-acid cyclic peptide that is expressed in various tissues, including the central nervous system, heart, kidney, and blood vessels. It circulates in human plasma, and its plasma level is elevated in renal failure, congestive heart failure, diabetes, and portal hypertension. In the kidney, UII has vasodilatory and natriuretic effects, mediated through nitric oxide. The development of UII-receptor antagonists may provide a useful research tool, and a novel treatment for cardiorenal diseases

Applications of Partially Quenched Chiral Perturbation Theory

Partially quenched theories are theories in which the valence- and sea-quark masses are different. In this paper we calculate the nonanalytic one-loop corrections of some physical quantities: the chiral condensate, weak decay constants, Goldstone boson masses, B_K and the K+ to pi+ pi0 decay amplitude, using partially quenched chiral perturbation theory. Our results for weak decay constants and masses agree with, and generalize, results of previous work by Sharpe. We compare B_K and the K+ decay amplitude with their real-world values in some examples. For the latter quantity, two other systematic effects that plague lattice computations, namely, finite-volume effects and unphysical values of the quark masses and pion external momenta are also considered. We find that typical one-loop corrections can be substantial.Comment: 22 pages, TeX, refs. added, minor other changes, version to appear in Phys. Rev.

Preparation and Characterization of Monoclonal Antibodies Directed Against Antigenic Determinants of Recombinant Human Tumour Necrosis Factor (rTNF)

A large number of monoclonal antibodies (McAb) binding to antigenic determinants of human tumour necrosis factor (TNF) were prepared from two fusions of mouse myeloma NSO cells with spleen cells from Balb/c mice immunized with highly purified recombinant (r)TNF. Several of these McAbs were highly neutralizing with respect to the biological activity (cytotoxicity) of TNF manifested in L-929 C1.10 cells. Antibody competition experiments suggested the presence of at least two antigenic determinants on the rTNF molecule through which binding of McAb effects neutralization of biological activity. Some of these McAbs were shown to be suitable for the development of immuoassays to quantify rTNF

On Lattice Computations of K+ --> pi+ pi0 Decay at m_K =2m_pi

We use one-loop chiral perturbation theory to compare potential lattice computations of the K+ --> pi+ pi0 decay amplitude at m_K=2m_pi with the experimental value. We find that the combined one-loop effect due to this unphysical pion to kaon mass ratio and typical finite volume effects is still of order minus 20-30%, and appears to dominate the effects from quenching.Comment: 4 pages, revte

Dense and accurate motion and strain estimation in high resolution speckle images using an image-adaptive approach

Digital image processing methods represent a viable and well acknowledged alternative to strain gauges and interferometric techniques for determining full-field displacements and strains in materials under stress. This paper presents an image adaptive technique for dense motion and strain estimation using high-resolution speckle images that show the analyzed material in its original and deformed states. The algorithm starts by dividing the speckle image showing the original state into irregular cells taking into consideration both spatial and gradient image information present. Subsequently the Newton-Raphson digital image correlation technique is applied to calculate the corresponding motion for each cell. Adaptive spatial regularization in the form of the Geman-McClure robust spatial estimator is employed to increase the spatial consistency of the motion components of a cell with respect to the components of neighbouring cells. To obtain the final strain information, local least-squares fitting using a linear displacement model is performed on the horizontal and vertical displacement fields. To evaluate the presented image partitioning and strain estimation techniques two numerical and two real experiments are employed. The numerical experiments simulate the deformation of a specimen with constant strain across the surface as well as small rigid-body rotations present while real experiments consist specimens that undergo uniaxial stress. The results indicate very good accuracy of the recovered strains as well as better rotation insensitivity compared to classical techniques