268 research outputs found
Identifying Geographic Clusters: A Network Analytic Approach
In recent years there has been a growing interest in the role of networks and
clusters in the global economy. Despite being a popular research topic in
economics, sociology and urban studies, geographical clustering of human
activity has often studied been by means of predetermined geographical units
such as administrative divisions and metropolitan areas. This approach is
intrinsically time invariant and it does not allow one to differentiate between
different activities. Our goal in this paper is to present a new methodology
for identifying clusters, that can be applied to different empirical settings.
We use a graph approach based on k-shell decomposition to analyze world
biomedical research clusters based on PubMed scientific publications. We
identify research institutions and locate their activities in geographical
clusters. Leading areas of scientific production and their top performing
research institutions are consistently identified at different geographic
scales
La territorializzazione spontanea del centro storico: il caso di Viterbo
Lo studio qui proposto ha preso l’avvio da due eventi fondamentali per lo sviluppo urbanistico
della cittĂ di Viterbo, nessuno dei quali possiamo dire costituisca la conseguenza di una politica
urbana di indirizzo.
Il primo ha decretato, a partire dagli anni Ottanta del secolo scorso, lo spopolamento e il
progressivo degrado del centro storico a seguito del vero e proprio esodo verso i nuovi
insediamenti di edilizia economica e popolare e soprattutto verso le innumerevoli ville, costruite
facendole passare per fabbricati rurali, nelle zone agricole a ridosso della cittĂ ; il secondo,
tuttora in atto, registra una tendenza opposta in virtĂą dei mutamenti profondi occorsi nel tessuto
sociale e della mutata situazione economica.
Le scarse disponibilitĂ economiche hanno reso infatti nuovamente appetibili, da parte di nuovi
fruitori con scarse possibilitĂ economiche, i numerosi immobili del centro rimasti liberi e in
cattive condizioni di manutenzione, dapprima senza operare alcuna alterazione nel tessuto
edilizio esistente; quindi è iniziata un’operazione sistematica di portata ben diversa, mirata alla
trasformazione in unitĂ abitative minime dei locali situati al livello stradale adibiti un tempo a
magazzini e cantine.
Esigenze differenti di persone differenti hanno indotto una nuova territorializzazione della cittĂ
storica. Resta da capire in che misura questo processo sia stato previsto o valutato, e se la
costituzione di un tessuto sociale così omogeneo nella struttura possa considerarsi
positivamente ai fini del riequilibrio socio-economico complessivo, di cui il problema edilizioabitativo
rappresenta solo uno degli aspettiThe aim of this paper is to reflect on two major trends concerning the urban development of the
city of Viterbo, neither of which appears to stem from a precise urban policy.
The first one was the depopulation and progressive decline of the ancient city centre caused by
the relocation of the inhabitants towards the new council housing settlements and especially
towards the countless new villas, originally intended as farm houses on agricultural land
adjacent to the city.
The second one, still ongoing, is an opposite trend, the result of profound changes in the social
fabric of the society and of the present economic stagnation. Many unoccupied and neglected
houses and flats in the city centre are appealing to people with limited financial means, in spite
of the lack of upgrading. In addition, basements and cellars are being converted into actual
housing units.
The needs of the abovementioned people have triggered a new territorialisation of the historic
centre. It is yet to be determined to what extent this phenomenon has been contemplated and understood, and whether the rise of such a uniform social fabric should be construed as positive
for the general socioeconomic balance, of which the housing issue is only one of the factors.Peer Reviewe
The anatomy and clinical importance of the collateral circles between the vertebral arteries and the cervical, costo-cervical, and occipital branches in 52 living subjects.
The anatomy and clinical importance of the collateral circle between the external carotid arteries through an anastomosis between the superior thyroid arteries.
The measurement of the calibers and blood-flow velocities of the arteries of the circle of Willis: a statistical investigation of 120 living subjects using transcranial color-Doppler ultrasonography.
Internal carotid artery: relationship among arterial caliber, haematocrit and cerebral vascular resistance, investigation in eighty healthy men by echodoppler
The valves of the internal jugular veins: a statistical investigation in 120 living subjects using ultrasonic tomography.
Clinical Importance of the Supra-Isthmic Anastomosis between the Superior Thyroid Arteries in Six Cases of Occlusion of the Common Carotid Artery
The anatomy and clinical significance of the collateral circulation between the internal and external carotid arteries through the ophthalmic artery.
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