On the Nesterov-Todd Direction in Semidefinite Programming

On the Nesterov-Todd Direction in Semidefinite Programmin

Angiogenically active vascular endothelial growth factor is over-expressed in malignant human and rat prostate carcinoma cells

Vascular endothelial growth factor (VEGF) is one of the most potent factors for stimulating angiogenesis, an essential process required for expansion of primary tumour and dissemination of malignant cells. To investigate the possible role of VEGF in facilitating metastasis of prostate cancer via stimulating angiogenesis, we have used Northern and slot blotting, reverse transcription polymerase chain reaction, nucleotide sequence analysis and enzyme-linked immunosorbent assay to compare the VEGF expression in series of human and rat cell lines with either benign or malignant characteristics. We have also employed the chick chorioallantoic membrane (CAM) assay to measure the angiogenic activity of the VEGF derived from both benign and malignant cells. The level of VEGF mRNA expressed in the seven malignant human and rat cell lines is 3.5- to 10-fold higher than that expressed in the benign cell lines. The three metastatic variants, generated by transfection of a benign cell line with DNA extracted from prostate carcinoma cells, expressed 2.5 to 5 times more VEGF mRNA than their parental benign cells. While VEGF 121 and 165 were predominantly expressed by both the benign and malignant cells, the transcript representing VEGF 189 isoform was only detected in the malignant cells. At protein level, three human malignant cell lines produced more VEGF (2.7–7.9 ng ml−1) than the benign cell line (1.3 ng ml−1). CAM assay detected a VEGF-dependent angiogenic activity in the medium from malignant cells, but only a relatively weak VEGF-independent activity in the medium from benign cells. These results demonstrated that malignant cells did over-express VEGF and only the VEGF derived from malignant cells was angiogenically active. Thus, we suggest that the VEGF produced by malignant cells might play an important role in facilitating metastasis of prostatic cancer. © 2000 Cancer Research Campaig

Role of Interleukin 17 in arthritis chronicity through survival of synoviocytes via regulation of synoviolin expression

Background: The use of TNF inhibitors has been a major progress in the treatment of chronic inflammation. However, not all patients respond. In addition, response will be often lost when treatment is stopped. These clinical aspects indicate that other cytokines might be involved and we focus here on the role of IL-17. In addition, the chronic nature of joint inflammation may contribute to reduced response and enhanced chronicity. Therefore we studied the capacity of IL-17 to regulate synoviolin, an E3 ubiquitin ligase implicated in synovial hyperplasia in human rheumatoid arthritis (RA) FLS and in chronic reactivated streptococcal cell wall (SCW)-induced arthritis.<p></p> Methodology/Principal Findings: Chronic reactivated SCW-induced arthritis was examined in IL-17R deficient and wild-type mice. Synoviolin expression was analysed by real-time RT-PCR, Western Blot or immunostaining in RA FLS and tissue, and p53 assessed by Western Blot. Apoptosis was detected by annexin V/propidium iodide staining, SS DNA apoptosis ELISA kit or TUNEL staining and proliferation by PCNA staining. IL-17 receptor A (IL-17RA), IL-17 receptor C (IL-17-RC) or synoviolin inhibition were achieved by small interfering RNA (siRNA) or neutralizing antibodies. IL-17 induced sustained synoviolin expression in RA FLS. Sodium nitroprusside (SNP)-induced RA FLS apoptosis was associated with reduced synoviolin expression and was rescued by IL-17 treatment with a corresponding increase in synoviolin expression. IL-17RC or IL-17RA RNA interference increased SNP-induced apoptosis, and decreased IL-17-induced synoviolin. IL-17 rescued RA FLS from apoptosis induced by synoviolin knockdown. IL-17 and TNF had additive effects on synoviolin expression and protection against apoptosis induced by synoviolin knowndown. In IL-17R deficient mice, a decrease in arthritis severity was characterized by increased synovial apoptosis, reduced proliferation and a marked reduction in synoviolin expression. A distinct absence of synoviolin expressing germinal centres in IL-17R deficient mice contrasted with synoviolin positive B cells and Th17 cells in synovial germinal centre-like structures.<p></p> Conclusion/Significance: IL-17 induction of synoviolin may contribute at least in part to RA chronicity by prolonging the survival of RA FLS and immune cells in germinal centre reactions. These results extend the role of IL-17 to synovial hyperplasia.<p></p&gt

Stabilized Kuramoto-Sivashinsky system

A model consisting of a mixed Kuramoto - Sivashinsky - KdV equation, linearly coupled to an extra linear dissipative equation, is proposed. The model applies to the description of surface waves on multilayered liquid films. The extra equation makes its possible to stabilize the zero solution in the model, opening way to the existence of stable solitary pulses (SPs). Treating the dissipation and instability-generating gain in the model as small perturbations, we demonstrate that balance between them selects two steady-state solitons from their continuous family existing in the absence of the dissipation and gain. The may be stable, provided that the zero solution is stable. The prediction is completely confirmed by direct simulations. If the integration domain is not very large, some pulses are stable even when the zero background is unstable. Stable bound states of two and three pulses are found too. The work was supported, in a part, by a joint grant from the Israeli Minsitry of Science and Technology and Japan Society for Promotion of Science.Comment: A text file in the latex format and 20 eps files with figures. Physical Review E, in pres

Stable two-dimensional solitary pulses in linearly coupled dissipative Kadomtsev-Petviashvili equations

A two-dimensional (2D) generalization of the stabilized Kuramoto - Sivashinsky (KS) system is presented. It is based on the Kadomtsev-Petviashvili (KP) equation including dissipation of the generic (Newell -- Whitehead -- Segel, NWS) type and gain. The system directly applies to the description of gravity-capillary waves on the surface of a liquid layer flowing down an inclined plane, with a surfactant diffusing along the layer's surface. Actually, the model is quite general, offering a simple way to stabilize nonlinear waves in media combining the weakly-2D dispersion of the KP type with gain and NWS dissipation. Parallel to this, another model is introduced, whose dissipative terms are isotropic, rather than of the NWS type. Both models include an additional linear equation of the advection-diffusion type, linearly coupled to the main KP-NWS equation. The extra equation provides for stability of the zero background in the system, opening a way to the existence of stable localized pulses. The consideration is focused on the case when the dispersive part of the system of the KP-I type, admitting the existence of 2D localized pulses. Treating the dissipation and gain as small perturbations and making use of the balance equation for the field momentum, we find that the equilibrium between the gain and losses may select two 2D solitons, from their continuous family existing in the conservative counterpart of the model (the latter family is found in an exact analytical form). The selected soliton with the larger amplitude is expected to be stable. Direct simulations completely corroborate the analytical predictions.Comment: a latex text file and 16 eps files with figures; Physical Review E, in pres

Mutually Penetrating Motion of Self-Organized 2D Patterns of Soliton-Like Structures

Results of numerical simulations of a recently derived most general dissipative-dispersive PDE describing evolution of a film flowing down an inclined plane are presented. They indicate that a novel complex type of spatiotemporal patterns can exist for strange attractors of nonequilibrium systems. It is suggested that real-life experiments satisfying the validity conditions of the theory are possible: the required sufficiently viscous liquids are readily available.Comment: minor corrections, 4 pages, LaTeX, 6 figures, mpeg simulations available upon or reques

Stable periodic waves in coupled Kuramoto-Sivashinsky - Korteweg-de Vries equations

Periodic waves are investigated in a system composed of a Kuramoto-Sivashinsky - Korteweg-de Vries (KS-KdV) equation, which is linearly coupled to an extra linear dissipative equation. The model describes, e.g., a two-layer liquid film flowing down an inclined plane. It has been recently shown that the system supports stable solitary pulses. We demonstrate that a perturbation analysis, based on the balance equation for the field momentum, predicts the existence of stable cnoidal waves (CnWs) in the same system. It is found that the mean value U of the wave field u in the main subsystem, but not the mean value of the extra field, affects the stability of the periodic waves. Three different areas can be distinguished inside the stability region in the parameter plane (L,U), where L is the wave's period. In these areas, stable are, respectively, CnWs with positive velocity, constant solutions, and CnWs with negative velocity. Multistability, i.e., the coexistence of several attractors, including the waves with several maxima per period, appears at large value of L. The analytical predictions are completely confirmed by direct simulations. Stable waves are also found numerically in the limit of vanishing dispersion, when the KS-KdV equation goes over into the KS one.Comment: a latex text file and 16 eps files with figures. Journal of the Physical Society of Japan, in pres

A Simple Model for Anisotropic Step Growth

We consider a simple model for the growth of isolated steps on a vicinal crystal surface. It incorporates diffusion and drift of adatoms on the terrace, and strong step and kink edge barriers. Using a combination of analytic methods and Monte Carlo simulations, we study the morphology of growing steps in detail. In particular, under typical Molecular Beam Epitaxy conditions the step morphology is linearly unstable in the model and develops fingers separated by deep cracks. The vertical roughness of the step grows linearly in time, while horizontally the fingers coarsen proportional to $t^{0.33}$. We develop scaling arguments to study the saturation of the ledge morphology for a finite width and length of the terrace.Comment: 20 pages, 12 figures; [email protected]

Surface-reconstructed Icosahedral Structures for Lead Clusters

We describe a new family of icosahedral structures for lead clusters. In general, structures in this family contain a Mackay icosahedral core with a reconstructed two-shell outer-layer. This family includes the anti-Mackay icosahedra, which have have a Mackay icosahedral core but with most of the surface atoms in hexagonal close-packed positions. Using a many-body glue potential for lead, we identify two icosahedral structures in this family which have the lowest energies of any known structure in the size range from 900 to 15000 lead atoms. We show that these structures are stabilized by a feature of the many-body glue part of the interatomic potential.Comment: 9 pages, 8 figure

Validation of Acute Myocardial Infarction (AMI) in the FDA’s Mini-Sentinel Distributed Database

The Food and Drug Administration’s (FDA) Mini-Sentinel is a pilot program that aims to conduct active surveillance to detect and refine safety signals that emerge for marketed medical products. The purpose of this Mini-Sentinel AMI Validation project was to: (a) develop and design an abstraction and adjudication process to use when full text medical record review is required to confirm a coded diagnosis; and (b) to test this approach by validating a code algorithm for acute myocardial infarction (AMI)