Workshop on Database Programming Languages

These are the revised proceedings of the Workshop on Database Programming Languages held at Roscoff, Finistère, France in September of 1987. The last few years have seen an enormous activity in the development of new programming languages and new programming environments for databases. The purpose of the workshop was to bring together researchers from both databases and programming languages to discuss recent developments in the two areas in the hope of overcoming some of the obstacles that appear to prevent the construction of a uniform database programming environment. The workshop, which follows a previous workshop held in Appin, Scotland in 1985, was extremely successful. The organizers were delighted with both the quality and volume of the submissions for this meeting, and it was regrettable that more papers could not be accepted. Both the stimulating discussions and the excellent food and scenery of the Brittany coast made the meeting thoroughly enjoyable. There were three main foci for this workshop: the type systems suitable for databases (especially object-oriented and complex-object databases,) the representation and manipulation of persistent structures, and extensions to deductive databases that allow for more general and flexible programming. Many of the papers describe recent results, or work in progress, and are indicative of the latest research trends in database programming languages. The organizers are extremely grateful for the financial support given by CRAI (Italy), Altaïr (France) and AT&T (USA). We would also like to acknowledge the organizational help provided by Florence Deshors, Hélène Gans and Pauline Turcaud of Altaïr, and by Karen Carter of the University of Pennsylvania

Who You Gonna Call? Analyzing the Run-time Call-site Behaviour of Ruby Applications

Applications written in dynamic languages are becoming larger and larger and companies increasingly use multi-million line codebases in production. At the same time, dynamic languages rely heavily on dynamic optimizations, particularly those that reduce the overhead of method calls. In this work, we study the call-site behavior of Ruby benchmarks that are being used to guide the development of upcoming Ruby implementations such as TruffleRuby and YJIT. We study the interaction of call-site lookup caches, method splitting, and elimination of duplicate call-targets. We find that these optimizations are indeed highly effective on both smaller and large benchmarks, methods and closures alike, and help to open up opportunities for further optimizations such as inlining. However, we show that TruffleRuby's splitting may be applied too aggressively on already-monomorphic call-sites, coming at a run-time cost. We also find three distinct patterns in the evolution of call-site behavior over time, which may help to guide novel optimizations. We believe that our results may support language implementers in optimizing runtime systems for large codebases built in dynamic languages

The role of WT1 in nephron endowment and glomeruloscerosis (GS) / Chronic Kidney Disease (CKD) /

PhD ThesisThe DDS/+ mouse is a model for glomerulosclerosis in Denys Drash Syndrome (DDS). The mutation results in a 20% reduction in nephron number that triggers a compensatory cascade of events leading to glomerulosclerosis. However, the mechanisms controlling the rate of maturation of nephrons and determining final nephron number within a kidney are not fully known. Stereological examinations on newborn kidneys were performed for glomerular count. Microarray analysis of foetal kidneys was carried out to reveal differentially expressed genes. 1136 differentially expressed genes were identified by microarray, of which the top 5 genes encoded mitochondrial tRNAs. Ingenuity Pathway Analysis indicated the involvement of renal developmental and tRNA splicing in the underlying mechanisms. Cross-database analyses revealed at least 216 genes that contain intragenic WT1 target sequence therefor represent potential direct targets of WT1 that are mis expressed due to the mutation. Given the expression changes of apoptosis related genes, TUNEL staining to identify apoptosis was carried out to reveal insignificant differences between genotypes. Given abnormal expression of mitochondrial tRNAs, immunofluorescence and western blotting were carried out and confirmed the presence of WT1 protein in mitochondrial isolates. Furthermore, metabolic profiling revealed abnormalities in the oxidative phosphorylation system in WT1 mutant cells compared with wild type. This study identified a list of genes that are associated with WT1 induced nephron underdosing, many of which have not previously been linked with nephrogenesis. The data suggests a role for apoptosis in nephron underdosing, however, more strikingly, the differentially expressed genes point to more complex molecular interactions involving mitochondria and WT1. To date, there are no reports of WT1 involvement in any aspect of mitochondrial biology. Molecular analyses verified WT1 protein is found in mitochondria indicating the potential for direct involvement of WT1 in mitochondria and, therefore, a potential for mitochondrial involvement in nephron development and endowment. These data suggest a previously unrecognised component of nephrogenesis that should be considered in future investigations to further uncover the various pathways involved in final nephron endowment

Equational Formulas and Pattern Operations in Initial Order-Sorted Algebras

A pattern, i.e., a term possibly with variables, denotes the set (language) of all its ground instances. In an untyped setting, symbolic operations on finite sets of patterns can represent Boolean operations on languages. But for the more expressive patterns needed in declarative languages supporting rich type disciplines such as subtype polymorphism untyped pattern operations and algorithms break down. We show how they can be properly defined by means of a signature transformation that enriches the types of the original signature. We also show that this transformation allows a systematic reduction of the first-order logic properties of an initial order-sorted algebra supporting subtype-polymorphic functions to equivalent properties of an initial many-sorted (i.e., simply typed) algebra. This yields a new, simple proof of the known decidability of the first-order theory of an initial order-sorted algebra.Partially supported by NSF Grant CNS 13-19109.Ope

Una teoría dinámica orientada a objetos como fundamento formal para el proceso de desarrollo de software basado en modelos

La primera etapa del trabajo consistió en el análisis de las diferentes técnicas de modelado orientado a objetos y su influencia sobre el proceso de desarrollo de software basado en modelos. Este análisis nos condujo a reconocer las claras ventajas que ofrece la integración de técnicas de modelado formales con técnicas no formales aceptadas y usadas por los ingenieros de software típicos.\nEl siguiente paso consistió en estudiar las propuestas existentes acerca de cómo efectivizar la mencionada integración, con el objetivo de identificar aspectos potencialmente mejorables.\nFinalmente y como consecuencia del análisis previo, definimos una nueva propuesta de integración la cual aporta los beneficios esperados para un método de integración standard pero además incorpora ciertas características que no han sido cubiertas satisfactoriamente por las propuestas anteriores, tales como evolución, reusabilidad y métricas de modelos. Además nuestra propuesta se basa en una estructura formal de primer orden que, en contraste con las estructuras de orden superior, facilita los procedimientos para calcular la validez de las fórmulas.\nLa parte restante de esta tesis está organizada de la siguiente forma:\nEn los capítulos 2 y 3 describimos detalladamente un lenguaje gráfico de especificación (UML) y un lenguaje formal (Lógica Dinámica) respectivamente. En el capítulo 4 discutimos las distintas propuestas para lograr la integración de ambas técnicas. En el capítulo 5 presentamos nuestra propuesta: la M&D-theory. El capítulo 6 contiene ejemplos de los principales beneficios standard provistos por la M&D-theory. En los capítulos 7, 8 y 9 demostramos la utilidad de nuestra formalización para expresar evolución de modelos, métricas de calidad y temas de reuso tales como contratos y patrones de diseño. Finalmente el capítulo 10 contiene conclusiones, reflexiones y comentarios acerca del trabajo presentado.Doctor en Ciencias Exactas, orientación Informátic