117,470 research outputs found
Optimal location of resources and Steiner symmetry in a population dynamics model in heterogeneous environments
No full textThe subject of this paper is inspired by Cantrell and Cosner (1989) and Cosner, Cuccu and Porru (2013). Cantrell and Cosner (1989) investigate the dynamics of a population in heterogeneous environments by means of diffusive logistic equations. An important part of their study consists in finding sufficient conditions which guarantee the survival of the species. Mathematically, this task leads to the weighted eigenvalue problem in a bounded smooth domain , , under homogeneous Dirichlet boundary conditions, where and . The domain represents the environment and , called the local growth rate, says where the favourable and unfavourable habitats are located. Then, Cantrell and Cosner (1989) consider a class of weights corresponding to environments where the total sizes of favourable and unfavourable habitats are fixed, but their spatial arrangement is allowed to change; they determine the best choice among them for the population to survive.
In our work we consider a sort of refinement of the result above. We write the weight as sum of two (or more) terms, i.e. , where and represent the spatial densities of the two resources which contribute to form the local growth rate . Then, we fix the total size of each resource allowing its spatial location to vary. As our first main result, we show that there exists an optimal choice of and and find the form of the optimizers. Our proof relies on some results in Cosner, Cuccu and Porru (2013) and on a new property (to our knowledge) about the classes of rearrangements of functions. Moreover, we show that if is Steiner symmetric, then the best arrangement of the resources inherits the same kind of symmetry. (Actually, this is proved in the more general context of the classes of rearrangements of measurable functions
Antonio Valente. Il cinema e la costruzione dell’artificio
No full textIl volume raccoglie una serie di documenti inediti e di contributi che, per la prima volta, rendono conto dell'attività di Antonio Valente, architetteo, architetto per il cinema, scenotecnico e costumista
Logistic hubs and support for radical-right populism: Evidence from Italy
No full textIncreasing discontent and the associated growing support for populist parties have been attributed to several drivers, including globalization, technological change, and migration waves. We analyse a phenomenon that encompasses a mix of economic and cultural grievances — the logistic revolution. The Italian logistics industry is characterized by a heavy reliance on low-paying and precarious contracts, it employs a large number of foreign workers, and is dominated by multinational corporations. The construction of large logistic hubs can increase the feeling of economic insecurity and trigger cultural backlash against foreign workers and large corporations. This, in turn, can create a favourable environment for populist radical right-wing parties that portray themselves as protectors of traditional values and national identity, and as defenders of the working class against the perceived threats posed by globalization, immigration, and large corporations. Through an IV and a DiD approach, we provide evidence that the support for Lega, a populist radical-right party, grew in Italian municipalities where new logistic hubs have been built
Tra estetica e ideologia: il dibattito critico e gli apporti teorici (Chiarini, Aristarco, Ragghianti)
No full text
Il diritto diseguale delle quote di genere nelle società
No full textLa l. 12 luglio 2011, n. 120, ha imposto alle società quotate in mercati regolamentati e a quelle a controllo pubblico un ben preciso criterio di composizione degli organi sociali, in base al quale al genere meno rappresentato spetta almeno un terzo dei componenti. Tale legge, che si fa apprezzare – anche – sotto il profilo della tecnica di redazione degli atti normativi, e che sta producendo gli effetti voluti, considerato che la presenza femminile negli organi di amministrazione e di controllo di tali società è cresciuta in maniera sensibile negli ultimi anni, lascia però qualche perplessità, e presta il fianco a non poche critiche, in particolar modo legate alle modalità con le quali si dovrà raggiungere l’equilibrio di genere, che infatti si occupano solo dell’esito della selezione e non del suo processo.In accordance with law n. 120, passed the 12th of July 2011, listed companies in regulated markets and companies under the control of public authorities have to comply with a very precise criterion for the composition of corporate bodies, on the basis of which the least represented gender has at least one third of the members. On the one hand, it must be said – with no doubt, and for many reasons – that this is a good law, especially for its rule making technique, and in terms of effectiveness, given that the presence of women on companies’ boards has increased significantly in recent years. On the other hand, the law lays itself open to criticism. A criticism especially related to the ways by which gender balance must be achieved, because they only deal with the selection’s outcome and not with its process
Introduzione al linguaggio del film
No full textIl volume si propone quale punto d'inizio per lo studio del cinema, fornendo al lettore le nozioni e le conoscenze di base e tentando al contempo di instillare curiosità e interesse per futuri approfondimenti. A partire dall'inquadratura, il testo prende in esame tutte le componenti del linguaggio cinematografico, guardando da un lato alle definizioni teoriche e dall'altro alle forme storiche in cui sono state tradotte. Il percorso si snoda attraverso l'analisi dei fattori elementari dai movimenti della macchina da presa al montaggio, dalla dimensione figurativa a quella audiovisiva per affrontare infine i problemi più complessi relativi alla narrazione e alle sue regole
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