A comprehensive semantic framework for data integration systems

A data integration system provides the user with a unified view, called global schema, of the data residing at different sources. Users issue their queries against the global schema, and the system computes answers to queries by suitably accessing the sources, through the mapping, i.e., the specification of the relationship between the global schema and the sources. Since sources are in general autonomous subsystems, the information provided by the data at the sources and the mapping is likely not to be consistent with the knowledge expressed by the global schema. Therefore, the question arises of how to interpret user queries in such a situation, i.e., in the presence of data contradicting the global schema and the mapping. In this paper, we provide an in-depth analysis of the problem of dealing with inconsistencies in data integration systems. In this respect, we highlight the central role played by the mapping, and propose a general “mapping-centered” semantics that allows for computing significant answers to user queries even in the presence of inconsistent information. Based on such a semantic analysis, we define a general formal framework for data integration. Then, we argue that our semantic approach formalizes a very reasonable way of handling inconsistency in such systems, since practically all the existing proposals in the literature can be reconstructed in our framework. This allows for comparing and evaluating the different existing proposals.     

Are the inhibitory and faciliatory effects during retrieval of semantically related items present in amnestic mild cognitive impairment?

Prefrontal functions subserve inhibition control for retrieval of semantically related items inducing forgetting 19 a-MCI patients and 29 controls underwent neuropsychological evaluation and retrieval-practice paradigm (RPP) to estimate baseline remember (BR), retrieval-induced facilitation (FAC) and retrieval-induced forgetting (RIF). A-MCI patients underwent also 3 T-MRI to assess relationship between regional grey matter (rGM) volumes and RPP indexes Behaviourally, RIF and FAC were both observed controls, while RIF only was observed in a-MCI patients. In patients but not in controls, RIF was associated with cognitive efficiency and FAC with memory performance. Patients showed also associations between BR and rGM volumes in the precuneus, no association was found between rGM volumes and RIF and FAC. A-MCI patients did not benefit from repeated practice during retrieval of studied items, which is likely due to their memory disorder. In contrast, patient cognitive efficiency would drive retrieval suppression of interfering stimuli.     

Brief report: Building choice opportunities within a robot-assisted occupational program: A case study

Choice opportunities were built within an existing robot-assisted occupational program. The new version of the program (with choice opportunities) was then employed with a low-functioning, multiply handicapped man who had previously been trained in the old version of the same program (the one with no choice opportunities). The results have shown that the man responded “purposefully” to choice situations and maintained highly accurate activity engagement. The importance of providing choice opportunities to people with severe and multiple handicaps and the cost and benefits of the program used in this study are discussed.     

Divergent Thinking and Age-Related Changes

Aging can affect cognition in different ways. The extent to which aging affects divergent thinking is unclear. In this study, younger and older adults were compared at the performance on the Torrance Test of Creative Thinking in visual and verbal form. Results showed that older adults can think divergently as younger participants, although they produce fewer visual ideas. This finding involves implications for active aging, given that also older adults can be still capable to produce original ideas and improve living conditions surrounding them.     

The Ambivalent Effects of Participation on Performance and Job Stressors: The Role of Job Crafting and Autonomy

ABSTRACT

Literature provides mixed results on the effect of participatory practices on outcomes such as individual performance and job stressors. By examining these relationships via the mediation of job crafting behaviors, while considering the moderating effect of autonomy, we help clarifying the reasons behind the apparently ambiguous effects of participation. We surveyed 318 employees in an Italian mass retail company. On the one hand, we found a positive effect of participation on performance and a reduction of both role conflict and role overload thanks to increased job crafting behaviors aimed at seeking job resources. On the other hand, we also found that participation and autonomy may augment job stressors because of an associated increase of job crafting behaviors aimed at seeking challenging demands.