Localizations of the Category of A∞ Categories and Internal Homs

We prove that the localizations of the categories of dg categories, of cohomologically unital and strictly unital A 1e categories with respect to the corresponding classes of quasi-equivalences are all equivalent. Moreover we show that the last two localizations are equivalent to the corresponding quotients by the relation of being isomorphic in the cohomology of the A 1e category of A 1e functors. As an application we give a complete proof of a claim by Kontsevich stating that the category of internal Homs for two dg categories can be described as the category of strictly unital A 1e functors between them

Extracting exact time bounds from logical proofs

Accurate evaluation of delays of combinatorial circuits is crucial in circuit verification and design. In this paper we present a logical approach to timing analysis which allows us to compute exact stabilization bounds while proving the correctness of the boolean behavior

Snapshots generation via constructive logic

A software information system S allows users to store, retrieve and process information about the external world, typically in the form of a data base. We can differentiate two separate aspects in the data elaborated by S: the first concerns data types, while the second is related to the information on the external \u201creal world\u201d carried by the data. More precisely, a data type is a set of data together with the associated manipulations where the focus is on operations. In contrast, the other information carried by the data stored in S is strongly related to their meaning in the real world. The need for properly treating data according to their meaning is becoming increasingly important, due to the wide quantity of information exchanged on the Internet [5]. In this context, we are developing COOML [4] (Constructive Object Oriented Modeling Language), an OO specification language where the focus is on the information carried by data. The main features of COOML are: \u2013 a data model based on a predicative extension of the constructive intermediate logic E [3], following the Brower-Heyting-Kolmogorov interpretation of logical connectives; \u2013 a multi-layered structure, starting with the COOML logic layer, on top of which lies the problem domain logic, and finally the computation layer; \u2013 a data model based on the notion of \u201dpieces of information\u201d i : P, where i is a structured information (\u201dinformation value\u201d) giving constructive evidence for the truth of a specification P. We believe that COOML may have a role as an OO specification framework, and we are developing different prototypical tools. This work is in progress and more details are available at the COOML web page http://homepages.inf.ed.ac.uk/amomigl1/cooml. In this abstract, we focus on automatic snapshots generation [1]: in modeling languages (we concentrate on the UML [2] as the de-fact standard) a snapshot represents a system state (object diagram) and snapshots generation in the presence of OCL constraints has proved to be useful both for understanding a specification and verifying its consistency in the problem domain. In our approach, snapshots are represented by the pieces of information and our snapshots generation algorithm is driven by the constructive content of COOML specifications

Snapshot generation in a constructive object-oriented modeling language

CooML is an object-oriented modeling language where specifications are theories in a constructive logic designed to handle incomplete information. In this logic we view snapshots as a formal counterpart of object populations, which are associated with specifications via the constructive interpretation of logical connectives. In this paper, we introduce the \u201csnapshot semantics\u201d of CooML and we describe a snapshot generation (SG) algorithm, which can be applied to validate specifications in the spirit of OCL-like constraints over UML models. Differently from the latter and from the standard BHK semantics, the logic allows us to exploit a notion of partial validation that is appropriate to encodings characterised by incomplete information. SG is akin to model generation in answer set programming. We show that the algorithm is sound and complete so that its successful termination implies consistency of the system

On correct program schemas

We present our work on the representation and correctness of program schemas, in the context of logic program synthesis. Whereas most researchers represent schemas purely syntactically as higher-order expressions, we shall express a schema as an open rst-order theory that axiomatises a problem domain, called a specication framework, containing an open program that represents the template of the schema. We will show that using our approach we can dene a meaningful notion of correctness for schemas, viz. that correct program schemas can be expressed as parametric specication frameworks containing templates that are steadfast, i.e. programs that are always correct provided their open relations are computed correctly. © Springer-Verlag Berlin Heidelberg 1998

Novel bicistronic lentiviral vectors correct beta-Hexosaminidase deficiency in neural and hematopoietic stem cells and progeny: implications for in vivo and ex vivo gene therapy of GM2 gangliosidosis

The favorable outcome of in vivo and ex vivo gene therapy approaches in several Lysosomal Storage Diseases suggests that these treatment strategies might equally benefit GM2 gangliosidosis. Tay-Sachs and Sandhoff disease (the main forms of GM2 gangliosidosis) result from mutations in either the HEXA or HERB genes encoding, respectively, the alpha- or beta-subunits of the lysosomal beta-Hexosaminidase enzyme. In physiological conditions, alpha- and beta-subunits combine to generate beta-Hexosaminidase A (HexA, alpha beta) and beta-Hexosaminidase B (HexB, 1313). A major impairment to establishing in vivo or ex vivo gene therapy for GM2 gangliosidosis is the need to synthesize the alpha- and beta-subunits at high levels and with the correct stoichiometric ratio, and to safely deliver the therapeutic products to all affected tissues/organs. Here, we report the generation and in vitro validation of novel bicistronic lentiviral vectors (LVs) encoding for both the murine and human codon optimized Hexa and Hex!) genes. We show that these LVs drive the safe and coordinate expression of the alpha- and beta-subunits, leading to supranormal levels of beta-Hexosaminidase activity with prevalent formation of a functional HexA in SD murine neurons and glia, murine bone marrow-derived hematopoietic stem/progenitor cells (HSPCs), and human SD fibroblasts. The restoration/overexpression of beta-Hexosaminidase leads to the reduction of intracellular GM2 ganglioside storage in transduced and in cross-corrected SD murine neural progeny, indicating that the transgenic enzyme is secreted and functional. Importantly, bicistronic LVs safely and efficiently transduce human neurons/glia and CD34 + HSPCs, which are target and effector cells, respectively, in prospective in vivo and ex vivo GT approaches. We anticipate that these bicistronic LVs may overcome the current requirement of two vectors co-delivering the alpha- or beta-subunits genes. Careful assessment of the safety and therapeutic potential of these bicistronic LVs in the SD murine model will pave the way to the clinical development of LV-based gene therapy for GM2 gangliosidosis

A constructive object oriented modeling language for information systems

One of the central aspects in an Information System is the meaning of data in the external world and the information carried by them. We propose a Constructive Object Oriented Modeling Language (COOML) for information systems, based on a constructive logic of pieces of information. The focus is on the definition of a data model suitable for organizing the information stored in OO systems. The underlying constructive logic supports a correct way of storing, exchanging and elaborating information

Monsters of Darwin: a strategic game based on Artificial Intelligence and Genetic Algorithms

The production of video games is a complex process, which involves several disciplines, spanning from art to computer science. The final goal is to keep entertained the players, by continuously providing them novel and challenging contents. However, the availability of a large variety of pre-produced material is often not possible. A similar problem can be found in many single-player game genres, where the simulated behaviour generated by the Artificial Intelligence algorithms must be coherent, believable, but also adequately variegate to maintain a satisfactory user experience. To this aim, there is a growing interest in the introduction of automatic or semi-automatic techniques to produce and manage the video game contents. In this paper, we present an example of strategic card battle video game based on the applications of Artificial Intelligence and Genetic Algorithms, where the game contents are dynamically adapted and produced during the game sessions

Validation of photographs usage to evaluate meat visual acceptability of young bulls finished in feedlot fed with or without essential oils

Forty ½ Brown Swiss × ½ Nellore crossbred bulls were distributed into three experimental groups: CON – diet without addition of essential oils; CLO – diet with average 5, 000 mg/animal/day of clove essential oils and CIN – diet with average 5, 000 mg/animal/day of cinnamon essential oils to evaluate three methodologies of visual acceptability: with steaks directly in Trays and Sequential and Random photos. Seventeen consumers evaluated visual appearance of meat using a 9-point structured hedonic scale. CON group presented higher shelf-life than essential oils groups. Trays and Sequential scores were similar in the majority of days; thus digital images could be used to evaluate colour evolution. However, Random photos resulted in lower scores and slower acceptability decrease than Trays and Sequential photos (p < 0.05) among the second and fifth day of display. Random photos presented a lower and more constant standard deviation than Trays and Sequential photos (p < 0.01) indicating that this methodology promoted a higher standard situation for meat colour evaluation