Gauge invariant investigation of the nature of Confinement

We observe a strong correlation between the decrease in the number of action density peaks in SU(2) Yang-Mills configurations with cooling and that of the string tension. The nature and distribution of these peaks is investigated. The relationship with monopole currents after the abelian projection is also considered.Comment: uuencoded and Z-compressed file of the Postcript version of our contribution to LATTICE 95. 4 pages of text and 4 figure

Peeping into the SU(2) Gauge Vacuum

We study thermalised configurations of SU(2) gauge fields by cooling. An analysis of the effect of cooling is presented and global and statistical information is extracted.Comment: 3 pages, uuencoded compressed postscript file, contribution to LAT 9

SGSDesigner, the ODESGS Environment User Interface

In this demo, we will show SGSDesigner, the ODESGS Environment user interface. ODESGS Environment (the realization of the ODESGS Framework [1]) is an environment for supporting both a) the annotation of pre-existing Grid Services(GSs) and b) the design of new complex Semantic Grid Services(SGSs) in a (semi) automatic way. In the demo we will focus in the annotation of a WSRF GS, using the annotation process proposed by the ODESGS Framework

SWSDesigner: The Graphical Interface of ODESWS

ODESWS is a development environment to design Semantic Web Services (SWS) at the knowledge level. ODESWS describe the service following a problem-solving approach in which the SWS are modelled using tasks, to represent the SWS functional features, and methods, to describe the SWS internal structure. In this paper, we describe the ODESWS graphical interface (called SWSDesinger). This interface enables users to design SWS independently of the semantic markup language in which the service will be implemented, and once the design has been export the service to an SWS implementation languag

ODESWS, A Semantic Web Service Development

ODE SWS is a development environment to design Semantic Web Services (SWS) at the knowledge level. ODE SWS describe the service following a problem-solving approach in which the SWS are modeled using tasks, to represent the SWS functional features, and methods, to describe the SWS internal structure. In this paper, we describe the ODE SWS architecture and the capabilities of its graphical interface, which enables users to design SWS independently of the semantic markup language used to represent them

A Framework for Design and Composition of Semantic Web Services

Semantic Web Services (SWS) are Web Services (WS) whose description is semantically enhanced with markup languages (e.g., OWL-S). This semantic description will enable external agents and programs to discover, compose and invoke SWSs. However, as a previous step to the specification of SWSs in a language, it must be designed at a conceptual level to guarantee its correctness and avoid inconsistencies among its internal components. In this paper, we present a framework for design and (semi) automatic composition of SWSs at a language-independent and knowledge level. This framework is based on a stack of ontologies that (1) describe the different parts of a SWS; and (2) contain a set of axioms that are really design rules to be verified by the ontology instances. Based on these ontologies, design and composition of SWSs can be viewed as the correct instantiation of the ontologies themselves. Once these instances have been created they will be exported to SWS languages such as OWL-S

Gauge invariant structures and Confinement

By looking at cooled configurations on the lattice, we study the presence of peaks in the action density, or its electric and magnetic components, in the SU(2) gauge vacuum. The peaks are seen to be of instanton-like nature and their number variation takes care of the drop in the string tension observed when cooling. Possible explanations of this finding are analysed.Comment: uuencoded and compressed file of the Postcript file newpaper.ps, fig1.ps,fig2.eps,fig3.ps and fig4.ps. 13 pages of text and 4 figures Style modifications and misprints correcte

Hypoxic Cell Waves around Necrotic Cores in Glioblastoma: A Biomathematical Model and its Therapeutic Implications

Glioblastoma is a rapidly evolving high-grade astrocytoma that is distinguished pathologically from lower grade gliomas by the presence of necrosis and microvascular hiperplasia. Necrotic areas are typically surrounded by hypercellular regions known as "pseudopalisades" originated by local tumor vessel occlusions that induce collective cellular migration events. This leads to the formation of waves of tumor cells actively migrating away from central hypoxia. We present a mathematical model that incorporates the interplay among two tumor cell phenotypes, a necrotic core and the oxygen distribution. Our simulations reveal the formation of a traveling wave of tumor cells that reproduces the observed histologic patterns of pseudopalisades. Additional simulations of the model equations show that preventing the collapse of tumor microvessels leads to slower glioma invasion, a fact that might be exploited for therapeutic purposes.Comment: 29 pages, 9 figure

Vector magnetic hysteresis of hard superconductors

Critical state problems which incorporate more than one component for the magnetization vector of hard superconductors are investigated. The theory is based on the minimization of a cost functional ${\cal C}[\vec{H}(\vec{x})]$ which weighs the changes of the magnetic field vector within the sample. We show that Bean's simplest prescription of choosing the correct sign for the critical current density $J_c$ in one dimensional problems is just a particular case of finding the components of the vector $\vec{J}_c$. $\vec{J}_c$ is determined by minimizing ${\cal C}$ under the constraint $\vec{J}\in\Delta (\vec{H},\vec{x})$, with $\Delta$ a bounded set. Upon the selection of different sets $\Delta$ we discuss existing crossed field measurements and predict new observable features. It is shown that a complex behavior in the magnetization curves may be controlled by a single external parameter, i.e.: the maximum value of the applied magnetic field $H_m$.Comment: 10 pages, 9 figures, accepted in Phys. Rev.