Calidad de servicio electrónico : una perspectiva integradora en un contexto de servicios puros

XII,347 p.

Conservar o solo: um ato de amor com natureza.

2010

Mata ciliar é vida.

2010

Solo: um patrimônio ameaçado.

2010

Potencial climático da região semiárida do Piauí para a produção de uvas destinadas à elaboração de vinhos finos.

2010

The importance of interaction strength for food web dynamics and ecosystem functioning

Global biodiversity is eroding at an alarming rate, through a combination of anthropogenic disturbance and environmental change. Ecological communities are bewildering in their complexity. Experimental ecologists strive to understand the mechanisms that drive the stability and structure of these complex communities in a bid to inform nature conservation and management. Two fields of research have had high profile success at developing theories related to these stabilising structures and testing them through controlled experimentation. Biodiversity-ecosystem functioning (BEF) research has explored the likely consequences of biodiversity loss on the functioning of natural systems and the provision of important ecosystem services. Empirical tests of BEF theory often consist of simplified laboratory and field experiments, carried out on subsets of ecological communities. Such experiments often overlook key information relating to patterns of interactions, important relationships, and fundamental ecosystem properties. The study of multi-species predator-prey interactions has also contributed much to our understanding of how complex systems are structured, particularly through the importance of indirect effects and predator suppression of prey populations. A growing number of studies describe these complex interactions in detailed food webs, which encompass all the interactions in a community. This has led to recent calls for an integration of BEF research with the comprehensive study of food web properties and patterns, to help elucidate the mechanisms that allow complex communities to persist in nature. This thesis adopts such an approach, through experimentation at Lough Hyne marine reserve, in southwest Ireland. Complex communities were allowed to develop naturally in exclusion cages, with only the diversity of top trophic levels controlled. Species removals were carried out and the resulting changes to predator-prey interactions, ecosystem functioning, food web properties, and stability were studied in detail. The findings of these experiments contribute greatly to our understanding of the stability and structure of complex natural communities.

Mental hoop diaries: emotional memories of a college basketball game in rival fans.

The rivalry between the men's basketball teams of Duke University and the University of North Carolina-Chapel Hill (UNC) is one of the most storied traditions in college sports. A subculture of students at each university form social bonds with fellow fans, develop expertise in college basketball rules, team statistics, and individual players, and self-identify as a member of a fan group. The present study capitalized on the high personal investment of these fans and the strong affective tenor of a Duke-UNC basketball game to examine the neural correlates of emotional memory retrieval for a complex sporting event. Male fans watched a competitive, archived game in a social setting. During a subsequent functional magnetic resonance imaging session, participants viewed video clips depicting individual plays of the game that ended with the ball being released toward the basket. For each play, participants recalled whether or not the shot went into the basket. Hemodynamic signal changes time locked to correct memory decisions were analyzed as a function of emotional intensity and valence, according to the fan's perspective. Results showed intensity-modulated retrieval activity in midline cortical structures, sensorimotor cortex, the striatum, and the medial temporal lobe, including the amygdala. Positively valent memories specifically recruited processing in dorsal frontoparietal regions, and additional activity in the insula and medial temporal lobe for positively valent shots recalled with high confidence. This novel paradigm reveals how brain regions implicated in emotion, memory retrieval, visuomotor imagery, and social cognition contribute to the recollection of specific plays in the mind of a sports fan.

Reflexiones y representaciones del exilio: de El canto del peregrino (1999) a "El sefardí romántico" (2005)

El exilio es un tema recurrente en la obra de Angelina Muñiz-Huberman, miembro del llamado grupo hispanomexicano. La visión del exilio en su obra incluye no solo el exilio republicano sino también el del pueblo judío. Por eso, diferentes Diásporas históricas se superponen enriqueciendo el significado de la experiencia. En su ensayo El canto del peregrino: hacia una poética del exilio (1999) desarrolla sus pensamientos sobre el exilio y analiza numerosos trabajos de autores exiliados (judíos y republicanos españoles) centrándose en como cada uno reflejó la vivencia del exilio en su trabajo.En mi opinión, las ideas desarrolladas en el ensayo se pueden encontrar en su novela El sefardí romántico: la azarosa vida de Mateo Alemán II (2005). El título de la novela establece una conexión directa con la novela picaresca y la vida judía aludiendo al autor converso de Guzmán de Alfarache (1599-1604). Siguiendo el patrón establecido por la novela picaresca clásica, el protagonista de Muñiz-Huberman viaja por España y Europa denunciando la intolerancia que llevó a la Guerra Civil española y a la II Guerra Mundial. Las circunstancias lo llevan al exilio en México, como en el caso de Mateo Alemán. Según la teoría de Ulrich Wicks, pícaros y exiliados tienen mucho en común en su búsqueda continua de libertad, libertad que el exiliado puede encontrar solo en el idioma, como expone Muñiz-Huberman en su ensayo.