Maristella Matera

In this paper we propose a framework for the design and development of adaptive Web applications. The framework leverages on the integration of two well established approaches: a conceptual model, complemented with a CASE tool for automatic code generation, and a language for expressing ECA rules, supported by an engine for rule execution. Such integration leads to a versatile and flexible adaptivity environment, whose advantage is twofold: on one hand, conceptual modeling and automatic code generation support an efficient development process; on the other hand a detached rule engine allows us to widen the set of adaptivity requirements that can be handled and to overcome some limitations of current modeling approaches.

ABSTRACT There is a lack of proposals, which consider user tasks for improving user interfaces for databases. In the paper we identify a set of meaningful tasks for this application area and we show how they can be used to provide more effective presentations of query results. This is obtained by allowing the presentation generation process to take into account semantic aspects, indicated by the tasks, which cannot be completely grasped by considering only data relationships.

ABSTRACT Distributed Interactive Workspaces (DIWs) are interactive environments, accessible through different devices, where end users create new content by exploring and aggregating data retrieved from distributed resources in the Web, tailor this content to their own personal needs, use it on different devices, and possibly share and co-create it with others. The need for collaborating with other people by means of DIWs is an important requirement that emerged in field studies conducted in different domains. This paper shows the extension of a platform for mashup composition to support collaboration through DIWs. In particular, it considers the possibility of producing annotated versions of DIWs, to add specific information and make it available to others without corrupting the original resources. It also investigates techniques for synchronous collaboration that enable a distributed creation and execution of the interactive workspaces on different devices and by different users.

Abstract. Through web mashups, web designers with even little programming skills have the opportunity to develop advanced applications by leveraging components accessible over the Web and offered by a multitude of service providers. So far, however, component selection has been merely based on functional requirements only, without considering the quality of the components and that of the final mashup. The quality in this context results from different factors, such as the software API, the contents, and the user interface.

ABSTRACT The spread of mobile devices empowers more and more end users to access services publicly available on the Web. It also encourages users to construct applications satisfying their situational needs, by customizing and combining the huge amount of online resources. Mobile mashups have the potential to accommodate this trend, providing a flexible paradigm for a service-based development of mobile applications. This paper introduces and End User Development (EUD) framework, based on a model-driven approach for the design and the automatic generation of mobile mashups. The approach is characterized by a "lightweight" composition paradigm that exploits visual notations for the specification of data integration and service synchronization rules.

Given the emergent need for usability, during last year's traditional development processes have been extended for enabling the fulfillment of usability requirements. Usability Evaluation Methods (UEMs) have been therefore proposed at any stage of the development process, to verify ...

ABSTRACT This paper presents a Web platform for the user-driven, service-based creation of Common Information Spaces (CISs). Two composition environments, characterized by intuitive visual notations, enable i) the integration of services to create UI-rich components and ii) the synchronization of components into interactive workspaces. Collaborative features allow multiple users to collaborate, synchronously and asynchronously, to share and co-create CISs.

ABSTRACT Context-awareness and adaptivity in web applications have been gaining momentum in web engineering over the last years, and it is nowadays recognized that, more than a mere technology aspect, they represent a first-class design concern. This acknowledgment has led to a revision of existing design methods and languages, finally resulting in runtime adaptation being considered a cross-cutting aspect throughout the whole development process. In this paper, we propose a radically new view on context-awareness and show how a well-done component-based development may allow the fast mashup of context-aware and adaptive web applications. The proposed approach comes with an intuitive graphical development environment, which will finally enable even end users themselves to mash up their adaptive applications.

ABSTRACT The Early Cretaceous Valanginian stage is marked by a pronounced increase in the marine carbonate delta13C record, which has commonly been interpreted as the expression of a global anoxic event (Erba et al., 2004). Here we propose to evaluate changes in paleoredox and paleoclimatic conditions, which occurred during the Valanginian carbon event by investigating phosphorus (P) and redox-sensitive trace-metal (TM) contents. We complement our geochemical analyses by an evaluation of organic-matter contents. We selected a series of representative sections along a basin-shelf transect in the western Tethys with the sections of Capriolo (northern Italy), Breggia (southern Switzerland), Vergol (southeastern France), Alvier (northeastern Switzerland) and Malleval (eastern France). We also analysed samples of Valanginian age from the Shatsky Rise (leg ODP 198, site 1213B). The onset of the carbon excursion is marked by maximal values in phosphorus accumulation rates (0.7, 0.4 and 4.1 mg P/cm2/kyr in the sections of Capriolo, Breggia and Alvier, respectively) and minimal values during the delta13C positive shift (0.3, 0.1 mg and 0.5 mg P/cm2/kyr in the sections of Capriolo, Breggia and Alvier, respectively). The trends in P accumulation observed are comparable to the global long-term trend established from the Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) (Föllmi, 1995), which indicate that the phosphorus enrichment observed in the western Tethyan has to be sought in general changes in the marine phosphorus cycle related to changes in the phosphorus delivery rate from the continent. TOC contents in the dark marly layers present in the sections of Capriolo and Breggia are characterized by values lower than 2 wt% and the HI/OI obtained suggest a terrestrial origin of the preserved organic matter. At Vergol, the organic matter of the "Barande" levels appears predominantly of marine origin. At Shatsky Rise, three of the analysed samples show TOC values of up to 4 w% and HI/OI indicate a type-II origin. The stratigraphic distribution of TM in the analysed sections shows no major excursions during the delta13C excursion in all studied sections. The only possible correlation is observed for the pre-delta13C event "Barande" levels, in which U, V, Co, As and Mo contents show maxima. At Shatsky rise, the organic-rich levels indicate higher TM values compared to the organic-lean samples of the site. Our results show that the onset of the shift is marked by an increase in P content, indicating an increase in continental runoff. This change is coeval with a change in clay-mineral assemblages with the disappearance of kaolinite. We also show that sediments of the western Tethyan realm lack evidence for the persistence of dys- to anaerobic conditions during the Valanginian positive delta13C excursion and that preserved organic matter from this time interval is largely of continental origin. Dysoxic to anoxic zones seem to be restricted to marginal seas of Atlantic (Meyers, 1987) and also to the Pacific. We suggest that the Valanginian delta13C shift is the consequence of an increase in continental carbon storage (as a sink of 12C-enriched organic carbon), coupled with the demise of shallow-water carbonate platforms (diminishing the storage capacity of 13C-enriched carbonate carbon). As such the Valanginian provides a more faithful natural analogue to present-day environmental change than most other Mesozoic OAEs, which are characterized by the development of ocean-wide dysaerobic to anaerobic conditions. REFERENCES Erba, E., Bartolini, A. and Larson, R.L., 2004. Valanginian Weissert oceanic anoxic event. Geology, 32, 149-152. Föllmi, K.B., 1995. 160 m.y. record of marine sedimentary phosphorus burial: coupling of climate and continental weathering under greenhouse and icehouse conditions. Geology 23, 859-862. Meyers, P.A., 1987. Organic-carbon content of sediments and rocks from deep sea drilling project sites 603, 604 and 605, Western marginof the North Atlantic. Init. Reports of the DSDP, 93, 1187-1194.

Abstract The need for better human-computer interaction (HCI) has been widely recognized and discussed, even in the database area. It is generally accepted that the quality of the interaction mainly depends on the interface characteristics. How does one recognize" good" interfaces? The use of a suitable metaphor is crucial. Unfortunately, to put it as a metaphor, speaking about metaphors in HCI is like walking on a slippery floor. We would like to come up with a definition of metaphor that is specific to the particular needs of the database area ...