Rapid Task-Models Development Using Sub-models, Sub-routines and Generic Components

International audienceWhilst task models are perceived as critical artifacts within User Centered Design methods, task models development is often considered as a resource and time consuming activity. Structuring techniques can support handling issues such as reuse and scalability and can improve analysts’ productivity and the overall quality of models. In this paper we propose (based on the notation of the HAMSTERS project) several means to structure task models and present how they can be used in order to increase reusability and scalability in task models. Besides sub-models and sub-routines, generic components are described. These mechanisms are duly illustrated within a project for the ground segments of satellite missions. This paper shows, by example, how such elements look like and how both readability and quality of models is improved by their use

Anchoring of proteins to lactic acid bacteria

The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been explored for their efficiency in attaching hybrid proteins to the cell membrane or cell wall of LAB. The most exploited anchoring regions are those with the LPXTG box that bind the proteins in a covalent way to the cell wall. In recent years, two new modes of cell wall protein anchoring have been studied and these may provide new approaches in surface display. The important progress that is being made with cell surface display of chimaeric proteins in the areas of vaccine development and enzyme- or whole-cell immobilisation is highlighted.

ISML: an interface specification meta-language

In this paper we present an abstract metaphor model situated within a model-based user interface framework. The inclusion of metaphors in graphical user interfaces is a well established, but mostly craft-based strategy to design. A substantial body of notations and tools can be found within the model-based user interface design literature, however an explicit treatment of metaphor and its mappings to other design views has yet to be addressed. We introduce the Interface Specification Meta-Language (ISML) framework and demonstrate its use in comparing the semantic and syntactic features of an interactive system. Challenges facing this research are outlined and further work proposed

Turbulent mixing of particles under tidal bores: An experimental analysis

A tidal bore develops in an estuary when the tidal range exceeds 4.5-6 m and the estuarine bathymetry amplifies the tidal wave. The bore is an abrupt rise in water depth associated with a discontinuity in velocity and pressure fields at the front. Herein the free-surface properties and the turbulent mixing of light-weight particles were investigated during the passage of tidal bores. The free-surface properties were recorded using a non-intrusive technique, while particle tracking was performed under undular and breaking bores. A basic result was the identification of a broad spectrum of particle trajectories, linked with the existence of large-scale vortical structures. These turbulent structures were responsible for the vertical water mixing as a tidal bore propagates upstream in an estuary. The large-scale eddies were also responsible for the rapid longitudinal dispersion of particulates, such as fish eggs, with some form of preferential motion, depending upon the particle's vertical elevation

The APEX framework: prototyping of ubiquitous environments based on Petri Nets

The user experience of ubiquitous environments is a determining factor in their success. The characteristics of such systems must be explored as early as possible to anticipate potential user problems, and to reduce the cost of redesign. However, the development of early prototypes to be evaluated in the target environment can be disruptive to the ongoing system and therefore unacceptable. This paper reports on an ongoing effort to explore how model-based rapid prototyping of ubiquitous environments might be used to avoid actual deployment while still enabling users to interact with a representation of the system. The paper describes APEX, a framework that brings together an existing 3D Application Server with CPN Tools. APEX-based prototypes enable users to navigate a virtual world simulation of the envisaged ubiquitous environment. The APEX architecture and the proposed CPN-based modelling approach are described. An example illustrates their use.Fundação para a Ciência e a Tecnologia (FCT) - bolsa de doutoramento SFRH/BD/41179/200

Mars Sample Return: The Value of Depth Profiles

Sample return from Mars offers the promise of data from Martian materials that have previously only been available from meteorites. Return of carefully selected samples may yield more information about the history of water and possible habitability through Martian history. Here we propose that samples collected from Mars should include depth profiles of material across the interface between weathered material on the surface of Mars into unweathered parent rock material. Such profiles have the potential to yield chemical kinetic data that can be used to estimate the duration of water and information about potential habitats on Mars

Identification of sortase A (SrtA) substrates in Streptococcus uberis: evidence for an additional hexapeptide (LPXXXD) sorting motif

Sortase (a transamidase) has been shown to be responsible for the covalent attachment of proteins to the bacterial cell wall. Anchoring is effected on secreted proteins containing a specific cell wall motif toward their C-terminus; that for sortase A (SrtA) in Gram-positive bacteria often incorporates the sequence LPXTG. Such surface proteins are often characterized as virulence determinants and play important roles during the establishment and persistence of infection. Intramammary infection with Streptococcus uberis is a common cause of bovine mastitis, which impacts on animal health and welfare and the economics of milk production. Comparison of stringently produced cell wall fractions from S. uberis and an isogenic mutant strain lacking SrtA permitted identification of 9 proteins likely to be covalently anchored at the cell surface. Analysis of these sequences implied the presence of two anchoring motifs for S. uberis, the classical LPXTG motif and an additional LPXXXD motif

Engajamento Político Transnacional e a Incorporação Cívica de Imigrantes Mexicanos nos Estados Unidos

Many migrants to the U.S. are engaged in public affairs in their country of origin. Whether such engagement impedes or encourages engagement in American politics remains an open question. Drawing from a unique two-wave panel survey of Mexican immigrants conducted in 2006, with surveys waves fielded to correspond to national elections in Mexico and the United States, we examine the relationship between transnational political engagement and attentiveness to American politics. The findings indicate that remote political engagement in Mexican politics is not a barrier to incorporation in the U.S. context. On the contrary, engagement in Mexican campaigns can stimulate interest and participation in U.S. elections.Muchos de los migrantes a los Estados Unidos se involucran en la vida cívica de su país de origen. Es pregunta abierta si tal participación impide o promueve la participación en la política norteamericana. Utilizando datos de una encuesta de inmigrantes mexicanos en dos olas llevadas a cabo en 2006, coordinadas con las elecciones nacionales en México y los Estados Unidos, investigamos la relación entre la participación política trasnacional y la atención a la política norteamericana. Los hallazgos señalan que la participación en la política mexicana no es obstáculo a la incorporación cívica en el contexto norteamericano. Al contrario, la atención a las campañas mexicanas puede estimular el interés y la participación en las elecciones estadunidenses.Muitas pessoas que migram para os Estados Unidos continuam engajadas em assuntos públicos em seu país de origem, mas não está claro se esse engajamento impede ou incentiva o envolvimento na política americana. O presente estudo examina a relação entre o engajamento político transnacional e a atenção à política americana, com base em uma pesquisa de painel de duas ondas realizada com imigrantes mexicanos em 2006. As duas ondas da pesquisa correspondem às eleições nacionais no México e nos Estados Unidos. Os resultados indicam que o engajamento à distância na política mexicana não é uma barreira para a incorporação no contexto dos Estados Unidos. Pelo contrário, o engajamento em campanhas mexicanas pode estimular o interesse e a participação nas eleições americanas

A biochemical analysis of the interaction of victorin and oats

Victoria blight of oats is caused by the fungus Cochhobolus victoriae. This fungus is pathogenic due to its ability to produce the host-selective toxin victorin. Previously, a 100-kD protein that binds victorin in vivo only in susceptible genotypes was identified as the P protein of the glycine decarboxylase complex (GDC). Victorin is a potent in vivo inhibitor of GDC. Leaf slices pretreated with victorin displayed an effective Victorin inhibited the concentration for 50% inhibition (EC₅₀) of 81 μM for GDA. glycine-bicarbonate exchange reaction in vitro with an EC₅₀ of 23 μM. We also identified a 15-kD mitochondrial protein in susceptible and resistant genotypes that hound victorin. Amino acid sequence analysis indicated this protein is the H protein component of the GDC. Thus, victorin specifically binds to two components of the GDC. Victorin had no detectable effect on GDC in isolated mitochondria, apparently due to the inability of isolated mitochondria to import victorin. The interaction of victorin with the GDC may be central to victorin's mode of action. Supporting this observation is the finding that CO₂ gives partial protection against victorin. Elevated CO₂ is known to ameliorate the effect of GDC inhibition. Victorin treated plants incubated in the light develop more severe symptoms than dark-incubated plants. Victorin appears to induce a plant-wide signal transduction cascade, resulting in diverse effects. Victorin induces specific proteolytic cleavage of the Rubisco large subunit (LSU). Leaf slices incubated with victorin for 4 hours in the dark accumulate a form of LSU which is cleaved after the N-terminal lysine 14. LSU cleavage in leaf slices is prevented by the protease inhibitors E-64 and calpeptin. LaCl₃ prevents this cleavage of LSU and LaCl₃ also confers complete protection against victorin at the whole plant level. Victorin also causes lipid peroxidation as measured by MDA accumulation. DNA laddering is seen in leaves after 3 hr treatment with toxin. The ethylene inhibitors AOA and STS give significant protection against victorin at the whole plant level, and also prevent LSU cleavage