The influence of individual and colony level variation in behavior on colony performance in ants

In my dissertation I investigated the influence of behavioral variation between and within ant colonies on group performance. In particular, I analyzed how evolution shapes behavior in response to ecological conditions, and whether within-group diversity improves productivity as suggested by theory. Our field and laboratory experiments showed that behavioral diverse groups are more productive. Different aggression levels within colonies were beneficial under competitive field situations, whereas diversity in brood care and exploratory behavior were favored in non-competitive laboratory situations. We then examined whether population density and social parasite presence shape aggression through phenotypic plasticity and/or natural selection. The importance of selection was indicated by the absence of density or parasite effects on aggression in a field manipulation. Indeed, more aggressive colonies fared better under high density and during parasite attack. When analyzing the proximate causes of individual behavioral variation, ovarian development was shown to be linked to division of labor and aggressiveness. Finally, our studies show that differences in the collective behavior can be linked to immune defense and productivity. My dissertation demonstrates that behavioral variation should be studied on multiple scales and when possible combined with physiological analyses to better understand the evolution of animal personalities in social groups.rn

Strategie competitive e innovazioni tecnologiche nel settore dei videogiochi: la Next-Generation

Il mercato video ludico è stato, ed è tuttora uno dei settori più redditizi e innovativi del mercato globale. L’evoluzione tecnologica ha permesso lo sviluppo di device e piattaforme da gioco sempre più performanti e in grado di soddisfare le esigenze dei consumatori. Con le nuove prospettive di gioco ci si sofferma a riflettere su quale sarà l’evoluzione del business dell’intrattenimento interattivo. In questo elaborato andremo a vedere come si sta evolvendo il mercato dei videogiochi, quali sono i nuovi scenari competitivi che si sono affiancati a questo settore, quali sono i segmenti che stanno avendo una crescita considerevole negli ultimi 10 anni, e cercheremo di capire come cambierà il “gameplay” da salotto, quindi quali saranno le prospettive future delle console da gioco.

Recurrent antitopographic inhibition mediates competitive stimulus selection in an attention network

Topographically organized neurons represent multiple stimuli within complex visual scenes and compete for subsequent processing in higher visual centers. The underlying neural mechanisms of this process have long been elusive. We investigate an experimentally constrained model of a midbrain structure: the optic tectum and the reciprocally connected nucleus isthmi. We show that a recurrent antitopographic inhibition mediates the competitive stimulus selection between distant sensory inputs in this visual pathway. This recurrent antitopographic inhibition is fundamentally different from surround inhibition in that it projects on all locations of its input layer, except to the locus from which it receives input. At a larger scale, the model shows how a focal top-down input from a forebrain region, the arcopallial gaze field, biases the competitive stimulus selection via the combined activation of a local excitation and the recurrent antitopographic inhibition. Our findings reveal circuit mechanisms of competitive stimulus selection and should motivate a search for anatomical implementations of these mechanisms in a range of vertebrate attentional systems.