Maude: specification and programming in rewriting logic

Maude is a high-level language and a high-performance system supporting executable specification and declarative programming in rewriting logic. Since rewriting logic contains equational logic, Maude also supports equational specification and programming in its sublanguage of functional modules and theories. The underlying equational logic chosen for Maude is membership equational logic, that has sorts, subsorts, operator overloading, and partiality definable by membership and equality conditions. Rewriting logic is reflective, in the sense of being able to express its own metalevel at the object level. Reflection is systematically exploited in Maude endowing the language with powerful metaprogramming capabilities, including both user-definable module operations and declarative strategies to guide the deduction process. This paper explains and illustrates with examples the main concepts of Maude's language design, including its underlying logic, functional, system and object-oriented modules, as well as parameterized modules, theories, and views. We also explain how Maude supports reflection, metaprogramming and internal strategies. The paper outlines the principles underlying the Maude system implementation, including its semicompilation techniques. We conclude with some remarks about applications, work on a formal environment for Maude, and a mobile language extension of Maude

Scintillation in the Circinus Galaxy water megamasers

We present observations of the 22 GHz water vapor megamasers in the Circinus galaxy made with the Tidbinbilla 70m telescope. These observations confirm the rapid variability seen earlier by Greenhill et al (1997). We show that this rapid variability can be explained by interstellar scintillation, based on what is now known of the interstellar scintillation seen in a significant number of flat spectrum AGN. The observed variability cannot be fully described by a simple model of either weak or diffractive scintillation.Comment: 10 pages, 5 figures. AJ accepte

Electrochemistry and application of a novel monosubstituted squarate electron-transfer mediator in a glucose oxidase-doped poly(phenol) sensor

Electrosynthetic poly(phenol) nanofilms were deposited in situ on platinum electrodes in the presence and absence of glucose oxidase. The synthesis charges and currents of the nonconducting polymer films were recorded at various applied potentials for films grown from 25–100 mM phenol concentrations. Film parameters such as the standard rate constant for film deposition, film thickness, and surface concentration of the poly(phenol) films were evaluated from the cyclic and step voltammograms of the polymerization process. A novel electron-transfer mediator consisting of monosubstituted 4-hydroxycyclobut-3-ene-1,2-dione (squarate) was used as a mediator for Pt/poly(phenol) nano-film/GOx amperometric glucose biosensors. Amperometric responses for 3-diphenylamino-4-hydroxycyclobut-3-ene-1,2- dione (diphenylaminosquarate: E°′ = of +328 mV/Ag-AgCl at pH 7.0)-mediated systems were measured by both steady-state amperometric and cyclic voltammetry. The sensor sensitivity was calculated to be 558 nA cm –2 (µM) –1

Gallus GBrowse: a unified genomic database for the chicken

Gallus GBrowse (http://birdbase.net/cgi-bin/gbrowse/gallus/) provides online access to genomic and other information about the chicken, Gallus gallus. The information provided by this resource includes predicted genes and Gene Ontology (GO) terms, links to Gallus In Situ Hybridization Analysis (GEISHA), Unigene and Reactome, the genomic positions of chicken genetic markers, SNPs and microarray probes, and mappings from turkey, condor and zebra finch DNA and EST sequences to the chicken genome. We also provide a BLAT server (http://birdbase.net/cgi-bin/webBlat) for matching user-provided sequences to the chicken genome. These tools make the Gallus GBrowse server a valuable resource for researchers seeking genomic information regarding the chicken and other avian species

Sox9 Transcriptionally Represses Spp1 to Prevent Matrix Mineralization in Maturing Heart Valves and Chondrocytes

Sox9 is an SRY-related transcription factor required for expression of cartilaginous genes in the developing skeletal system and heart valve structures. In contrast to positively regulating cartilaginous matrix, Sox9 also negatively regulates matrix mineralization associated with bone formation. While the transcriptional activation of Sox9 target genes during chondrogenesis has been characterized, the mechanisms by which Sox9 represses osteogenic processes are not so clear. Using ChIP-on-chip and luciferase assays we show that Sox9 binds and represses transactivation of the osteogenic glycoprotein Spp1. In addition, Sox9 knockdown in post natal mouse heart valve explants and rib chondrocyte cultures promotes Spp1 expression and matrix mineralization, while attenuating expression of cartilage genes Type II Collagen and Cartilage Link Protein. Further, we show that Spp1 is required for matrix mineralization induced by Sox9 knockdown. These studies provide insights into the molecular mechanisms by which Sox9 prevents pathologic matrix mineralization in tissues that must remain cartilaginous

Overcoming gaps to advance global health equity: a symposium on new directions for research

<p>Abstract</p> <p>The 20^thanniversary of the groundbreaking report of the Commission on Health Research for Development inspired a Symposium to assess progress made in strengthening essential national health research capacity in developing countries and in global research partnerships. Significant aspects of the health gains achieved in the 20^thcentury can be attributed to the advancement and translation of knowledge, and knowledge continues to occupy center stage amidst growing complexity that characterizes the global health field. The way forward will entail a reinvigoration of research-generated knowledge as a crucial ingredient for global cooperation and global health advances. To do this we will need to overcome daunting gaps, including the divides between domestic and global health, among the disciplines of research (biomedical, clinical, epidemiological, health systems), between clinical and public health approaches, public and private investments, and between knowledge gained and action implemented. Overcoming systematically these obstacles can accelerate progress towards research for equity in health and development.</p