Public Decisions: Solidarity and the Status Quo

A public decision model specifies a fixed set of alternatives A, a variable population, and a fixed set of admissible preferences over A, common to all agents. We study the implications, for any social choice function, of the principle of solidarity, in the class of all such models. The principle says that when the environment changes, all agents not responsible for the change should all be affected in the same direction: either all weakly win, or all weakly lose. We consider two formulations of this principle: population-monotonicity (Thomson, 1983); and replacement-domination (Moulin, 1987). Under weak additional requirements, but regardless of the domain of preferences considered, each of the two conditions implies (i) coalition-strategy-proofness; (ii) that the choice only depends on the set of preferences that are present in the society and not on the labels of agents, nor on the number of agents having a particular preference; (iii) that there exists a status quo point, i.e. an alternative always weakly Pareto-dominated by the alternative selected by the rule. We also prove that replacement-domination is generally at least as strong as population-monotonicity.

Comunidades virtuales, grupos y proyectos de investigación sobre IMS Learning Design : status quo, factores clave y retos inmediatos.

Resumen tomado de la publicación

Economia Criativa e a Mídia Radical: laboratórios experimentais para a inovação de plataformas midiáticas, conteúdos e recursos midiáticos

The Creative Economy is an experimental laboratory for the creation , innovation , invention and reinvention of the universe of media - analog and digital . The scenery in the media and converging technologies favors the process of “ creative destruction and destructive creation “ of this field . The mapping of basins and technological corridors distributed through the territory of concentrated areas creates an infrastructural chassis for the production of content , information and entertainment . As locus and logos of immaterial production , digital ecology that gives speed to the flow of production - planning, fundraising , publishing , distribution and enjoyment - and allows the dispossession of their local clusters , the fragmentation and dilution of their creative chains . The collective cultural production and creation appropriating these capilarizados articles and produce content against political, economic and social status quo . The land is fertile and favorable to the emergence of radical media and rebels that recreate the public sphere , and edit poor public spheres , alternative , radical and efficient , the tactical point of view . This article aims to contribute to studies and research that scour the ecosystem of the media for understanding the management of their creative processes, actors and critics of tangible and intangible resources that support their communication actions .

The international spine registry SPINE TANGO: status quo and first results

With an official life time of over 5 years, Spine Tango can meanwhile be considered the first international spine registry. In this paper we present an overview of frequency statistics of Spine Tango for demonstrating the genesis of questionnaire development and the constantly increasing activity in the registry. Results from two exemplar studies serve for showing concepts of data analysis applied to a spine registry. Between 2002 and 2006, about 6,000 datasets were submitted by 25 centres. Descriptive analyses were performed for demographic, surgical and follow-up data of three generations of the Spine Tango surgery and follow-up forms. The two exemplar studies used multiple linear regression models to identify potential predictor variables for the occurrence of dura lesions in posterior spinal fusion, and to evaluate which covariates influenced the length of hospital stay. Over the study period there was a rise in median patient age from 52.3 to 58.6 years in the Spine Tango data pool and an increasing percentage of degenerative diseases as main pathology from 59.9 to 71.4%. Posterior decompression was the most frequent surgical measure. About one-third of all patients had documented follow-ups. The complication rate remained below 10%. The exemplar studies identified "centre of intervention" and "number of segments of fusion" as predictors of the occurrence of dura lesions in posterior spinal fusion surgery. Length of hospital stay among patients with posterior fusion was significantly influenced by "centre of intervention", "surgeon credentials", "number of segments of fusion", "age group" and "sex". Data analysis from Spine Tango is possible but complicated by the incompatibility of questionnaire generations 1 and 2 with the more recent generation 3. Although descriptive and also analytic studies at evidence level 2++ can be performed, findings cannot yet be generalised to any specific country or patient population. Current limitations of Spine Tango include the low number and short duration of follow-ups and the lack of sufficiently detailed patient data on subgroup levels. Although the number of participants is steadily growing, no country is yet represented with a sufficient number of hospitals. Nevertheless, the benefits of the project for the whole spine community become increasingly visible.