Uniqueness of Gibbs Measure for Models With Uncountable Set of Spin Values on a Cayley Tree

We consider models with nearest-neighbor interactions and with the set $[0,1]$ of spin values, on a Cayley tree of order $k\geq 1$. It is known that the "splitting Gibbs measures" of the model can be described by solutions of a nonlinear integral equation. For arbitrary $k\geq 2$ we find a sufficient condition under which the integral equation has unique solution, hence under the condition the corresponding model has unique splitting Gibbs measure.Comment: 13 page

Mapping H4K20me3 onto the chromatin landscape of senescent cells indicates a function in control of cell senescence and tumor suppression through preservation of genetic and epigenetic stability

Background: Histone modification H4K20me3 and its methyltransferase SUV420H2 have been implicated in suppression of tumorigenesis. The underlying mechanism is unclear, although H4K20me3 abundance increases during cellular senescence, a stable proliferation arrest and tumor suppressor process, triggered by diverse molecular cues, including activated oncogenes. Here, we investigate the function of H4K20me3 in senescence and tumor suppression. Results: Using immunofluorescence and ChIP-seq we determine the distribution of H4K20me3 in proliferating and senescent human cells. Altered H4K20me3 in senescence is coupled to H4K16ac and DNA methylation changes in senescence. In senescent cells, H4K20me3 is especially enriched at DNA sequences contained within specialized domains of senescence-associated heterochromatin foci (SAHF), as well as specific families of non-genic and genic repeats. Altered H4K20me3 does not correlate strongly with changes in gene expression between proliferating and senescent cells; however, in senescent cells, but not proliferating cells, H4K20me3 enrichment at gene bodies correlates inversely with gene expression, reflecting de novo accumulation of H4K20me3 at repressed genes in senescent cells, including at genes also repressed in proliferating cells. Although elevated SUV420H2 upregulates H4K20me3, this does not accelerate senescence of primary human cells. However, elevated SUV420H2/H4K20me3 reinforces oncogene-induced senescence-associated proliferation arrest and slows tumorigenesis in vivo. Conclusions: These results corroborate a role for chromatin in underpinning the senescence phenotype but do not support a major role for H4K20me3 in initiation of senescence. Rather, we speculate that H4K20me3 plays a role in heterochromatinization and stabilization of the epigenome and genome of pre-malignant, oncogene-expressing senescent cells, thereby suppressing epigenetic and genetic instability and contributing to long-term senescence-mediated tumor suppression

Specification Composition for the Verification of Message Passing Program Composition

We present a specification composition technique, for improving the reliability of message passing applications composed by the Ensemble methodology. In Ensemble, applications are built by composing reusable executable program components designed with scalable communication interfaces. The composition is controlled by scripts. We define reusable specification components associated to program components, as well as their composition directed by the same Ensemble scripts, thus obtaining specifications of applications. We propose an extension of coloured Petri nets, which is used to define specification components. Composed specifications and applications may be validated or verified by available tools. Keywords: Message Passing Composition, Specification Composition, Reusable Program Component, Reusable Specification Component, Software Reliability, Coloured Petri Net.

Semantic Approaches to Structuring and Querying Web Sites

In order to pose effective queries to Web sites, some form of site data model must be implicitly or explicitly shared by users. Many approaches try to compensate for the lack of such a common model by considering the hypertextual structure of Web sites; unfortunately, this structure has usually little to do with data semantics. In this paper a different technique is proposed that allows for both navigational and logical/conceptual description of Web sites. The data model is based on WG-log, a query language based on the graph-oriented database model of GOOD [Gys94] and G-log [Par95], which allows the description of data manipulation primitives via (sets of) graph(s). The WG-log description of a Web site schema is lexically based on standard hypermedia design languages, thus allowing for easy schema generation by current hypermedia authoring environments. The use of WG-log for queries allows graphic query construction with respect to both the navigational and the logical parts of schema..

On the predictive validity of automatically activated approach/avoidance tendencies in abstaining alcohol-dependent patients.

Prominent addiction models posit that automatically activated approach/avoidance tendencies play a critical role in addiction. Nevertheless, only a limited number of studies have actually documented the relationship between relapse and automatically activated approach/avoidance tendencies. We compared automatically activated approach/avoidance tendencies towards alcohol in 40 abstaining alcohol-dependent patients and 40 controls. We also examined whether individual differences in automatically activated approach/avoidance tendencies towards alcohol are predictive of relapse in patients.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe