117,383 research outputs found
Seifert manifolds and (1,1)-knots
No full textThe aim of this paper is to investigate the relations between Seifert manifolds and (1,1)-knots. In particular, we prove that each orientable Seifert manifold with invariants{Oo,0| -1; (p,q),..., (p,q),(l, l-1)}, where (p,q) are taken n times, has a cyclically presented fundamental group and, moreover, it is the n-fold strongly-cyclic covering of the lens space L(|nlq - p|, q), branched over a suitable (1,1)-knot
Compact n-manifolds via (n+1)-colored graphs: a new approach
No full textWe introduce a representation via (n+1)-colored graphs of compact n.manifolds with (possibly empty) boundary, which appears to be very convenient for computer aided study and tabulation
Il "razionalismo" e l'architettura italiana tra le due guerre
No full textIl saggio ripercorre le vicende dell'architettura italiana tra le due guerre mondiali, focalizzando gli avvenimenti principali – tra l'esordio del "razionalismo" a Milano e la realizzazione del quartiere "imperiale" dell'E42 in Roma – ed evidenziando l'intreccio costante tra dibattito culturale e compiti politici assegnati all'architettura; l'intento è restituire l'ampio ventaglio di ricerche che impegna negli anni trenta la parte migliore della cultura progettuale italiana nella costruzione di una tradizione della modernità
Regional management of multi-species fisheries on the basis of shared stocks and property rights: a Mediterranean case
No full textFishery management is a complicated task that often results in overfishing, overcapacity, and low profits for the industry. The management of shared fish stocks is particularly problematic, especially if national authorities pursue different objectives. Multi-species fisheries add further complexity to the problem. It is no accident that management tools frequently used in Northern Europe, such as total allowable catches and individual quotas, are not applied in the Mediterranean Sea, where more target species are caught simultaneously. However, the European Commission intends to introduce a market-based driver for a strong, profitable fishing industry by phasing in transferable fishing concessions. This management approach is new for the Mediterranean, and it requires in-depth examination at institutional, legal, and economic levels. In this paper, after a review of the institutional setting, the economic perspective was analyzed by estimating the production function for the Italian small pelagic fishery in the Adriatic Sea. With the addition of Croatia to the European Union, the Adriatic Sea can become a Mediterranean communal exclusive fishing area. The results indicate that output measures such as total allowable catches and individual quotas should not cause serious discarding problems for this multi-species fisheryGestión regional de pesquerías multiespecíficas basada en stocks compartidos y derechos de propiedad: un caso Mediterráneo. – El manejo de la pesca es una tarea difícil que con frecuencia tiene como resultado la sobreexplotación de los recursos, la sobrecapitalización de las pesquerías y la baja rentabilidad de la industria pesquera. El manejo de los stocks compartidos es particularmente problemático, especialmente cuando las autoridades públicas persiguen objetivos diferentes. Las pesquerías multiespecíficas aumentan la complejidad del problema. No es accidental que instrumentos de manejo utilizados con frecuencia en el Norte de Europa, como los Totales Admisibles de Capturas (TACs) y las Cuotas Individuales, no sean aplicadas en el mar Mediterráneo, donde se capturan varias especies objetivo simultáneamente. De otro lado, la Comisión Europea piensa introducir un incentivo de mercado para favorecer el sector pesquero y hacerlo más fuerte y rentable, a través de la introducción paulatina de concesiones de pesca transferibles. Este modo de manejo es nuevo para el Mediterráneo, y requiere un análisis detallado a nivel institucional, legal y económico. En este artículo, además de una reseña del contexto institucional, analizamos la perspectiva económica estimando la función de producción para la flota pelágica italiana del mar Adriático. Con la inclusión de Croacia en la Unión Europea, el mar Adriático podría convertirse en una zona de pesca exclusiva comunitaria del Mediterráneo. Los resultados indican que las medidas de control sobre la producción, como los TACs y las Cuotas Individuales, no ocasionarían serios problemas de descarte para este tipo de pesqueria
La coerenza della modernità
No full textIl testo inquadra la figura dell'architetto Ettore Stella, formatosi a Roma e operante nel difficile contesto sociale ed economico della città di Matera nel secondo dopoguerra, in contatto con intellettuali e studiosi come Rocco Scotellaro, Carlo Levi e Rocco Mazzarone e, immediatamente prima della prematura scomparsa, con adriano Olivetti
Price-quantity relations and choice of the geographical market size in Italian fresh seafood products
No full textA correct planning and management of the fishing activities cannot ignore the market response to fish production. A wrong assumption about the market size during the empirical investigation can induce to errors in the preparation of the management plans. The purpose of this paper is to provide indications on the real extension (and therefore on the response) of the markets for some of the principal seafood species in Italy. An inverse system framework is followed to empirically investigate the price-quantity relations using a panel of five markets along the coast of the Adriatic Sea. The results confirm that considering only a large geographical size (e.g. national level) can be misleading if the markets are not integrated at this level (for example in the case of cuttlefish), while considering too limited geographical sizes (e.g. local level) can be misleading because the potential market integrations at regional (as in the case of hakes), national (anchovies) or intemationallevel are ignored
Bioeconomic equilibrium and supply regime for a multi-species multi-fleet fishery: an analysis in the Mediterranean Sea
No full textFishery authorities are often led by poor scientific knowledge about fish stock dynamics and socio-economic concerns, to adopt management choices that are similar to an open access situation. Management of transboundary fish stocks is particularly problematic because national authorities can pursue different objectives. Supply regimes are also affected by biological variables, strategic interaction and management choices. In this paper, we present a bioeconomic model in the case of two fleets competing for two target species. A numerical application, using a surplus production model and game theory, is performed for the small pelagic fishery in the Adriatic Sea. Different policy choices are assumed in the framework of competitive games.Les autorités responsables de la pêche ont souvent une connaissance insuffi-sante des dynamiques des stocks de poissons et des soucis socio-économiques,ce qui les amène à adopter des décisions en matière d’aménagement qui se rap-prochent d’une condition d’accès ouvert. L’aménagement des stocks de pois-sons transfrontaliers s’avère être particulièrement critique étant donné que lesautorités nationales peuvent poursuivre des objectifs différents. Les régimesd’approvisionnement sont aussi influencés par les variables biologiques, l’in-teraction stratégique et les décisions dans le domaine de l’aménagement. Danscet article, nous allons illustrer un modèle bioéconomique concernant deuxflottes qui sont en compétition pour deux espèces cibles. En nous appuyant surun modèle de production excédentaire et la théorie des jeux, nous proposonsune application numérique pour la pêche des petits pélagiques dans la merAdriatique. Différentes options de politiques sont avancées dans le cadre desjeux compétitif
Complessi residenziali Faenza Cristofani+Lelli A casa nella città diffusa
No full textL' articolo illustra tre diversi progetti residenziali posti in siti diversi. I complessi residenziali sono interessanti dal punto di vista della ricerca sul progetto urbano, infatti ogni opera è inserita in modo diverso in un contesto di periferia rarefatta tipica delle città di provincia
The external and commercial dimensions of the EU fisheries policy: An institutional approach applied to the whitefish case
No full textThis paper discusses the connections that exist between several policy areas concerning fisheries, namely
fisheries management and regulations in internal and external waters as well as commercial policies.
An institutional approach isused to describe the system by indicating the causal interactions and
feedbacks that exist between rules, stocks, catches, imports, and prices.The European Union,as one of
the major players in the fishing industry and market, is considered as the case study. The key argument of
the paper is that when catches decrease, essentially because of the use of inappropriate management
tools and strategy, national interest moves from fishers to other categories such as processors and
consumers, which involves several changes to external policies. Theanalys is presented here in shows that
this is exactly what is happening in the case of whitefish. Furthermore, the changing habits and
preferences of EU consumers have resulted in increasing substitution possibilities between different
species, most of which are imported. This fact combined with there duced level of EU catches means that
the EU is decreasingly able to affect international prices
Different techniques for ultrasound liver elastography
No full textThe advent of vibration controlled transient elastography (VCTE or simply TE) with Fibroscan in 2003 the first tool able to noninvasively quantify liver stiffness using ultrasound, thereby providing evidence of liver disease stage can be considered a milestone in hepatology given the limitations of biopsy in terms of
sampling and invasiveness. Thresholds for the differentiation of no/mild fibrosis from significant fibrosis, or severe fibrosis or cirrhosis have been provided with TE on the basis of many original works using histology as the reference standard.1,2 From 2009 onwards other new quantitative elastography technologies
started to arrive on the market, this time embedded in conventional ultrasound (US) devices. At present almost all ultrasound manufacturers have developed their own liver stiffness quantification modality.2 All share the capacity to assess tissue deformation and measure the speed of shearwaves travelling
perpendicular to the axis of an applied force (consisting of ultrasound energy, unlike the Fibroscan which uses the push of a piston). These technologies are collectively called shearwave elastography (SWE), with the two main categories being point SWE (pSWE), which samples a tiny linear portion of tissue
(few mm), and bidimensional SWE (2D-SWE), which samples large square areas 14cm2. A more detailed illustration of the various technologies is reported in the EFSUMB guidelines2 and is graphically summarized. Strain elastography is another technology that evaluates tissue stiffness and it is provided by
the large majority of manufacturers, since before the advent of SWE. However, it does not provide quantitative measurements of stiffness and did not prove to be as effective as SWE for liver disease: consequently, it has no current role in hepatology
- …
