Gateways as inter-modal nodes in different ages: The Venetian region, eighteenth to twentieth centuries

This paper focuses on the theoretical implications of a regional case studyfor the analysis of transportation networks and gateway functions. Thestarting point is the result of a research on the changing role of gateways,and on the relocation of the gateway function from one city to a series ofcities in the Venetian region from the eighteenth to the twentieth century.Against this evolution, I test the validity and usefulness of a definition of thegateway as a point of inter-modal exchange for its historical interpretation.Changing transport technologies involve different organisations of inter-modal exchanges, and imply more or less intense economic functions ofgateway cities. These changes intertwine with political events and deci-sions, and more general economic changes: they could at the same time beread as an effect of these transformations, and as a causal factor. From this perspective, a study of intermodality shows to be useful to shed new lighton specific changes in the structure of urban hierarchie

Premature Age-Related Comorbidities Among HIV-Infected Persons Compared With the General Population

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Late Holocene volcanic stratigraphy and eruption chronology of the dacitic Young Doña Juana volcano, Colombia

We present the late Holocene eruption his-tory of the poorly known Dona Juana volcanic complex, in SW Colombia, which last erupted in the twentieth century. This represents a case study for potentially active volcanism in the rural Northern Andes, where tropical climate conditions and a fragmented social memory blur the record of dormant volcanoes. We re-constructed the volcanic stratigraphy of the central-summit vent area by integrating new mapping at 1:5000 scale with radiocarbon ages, sedimentology analysis, and historical chronicles. Our results revealed cyclic transi-tions from lava-dome growth phases and col-lapse to explosive Vulcanian and possibly sub-plinian phases. Pyroclastic density currents were generated by dome collapse producing block-and-ash flows or by pyroclastic foun-tain/column collapse and were rapidly chan-nelized into the deeply incised fluvial valleys around the volcano summit. The pyroclastic density currents were similar to 4-10 x 106 m3 in vol -ume and deposited under granular flow- or fluid escape-dominated depositional regimes at high clast concentrations. In places, more dilute upper portions reached a wider areal distribution that affected the inhabited areas on high depositional terraces. The coefficient of friction (Delta H/L) is higher for block-and-ash flows and dense lava-bearing fountain/low-column-collapse pyroclastic density currents compared to pumice-bearing, column-col-lapse pyroclastic density currents. Associated mass-wasting processes included syneruptive and intereruptive debris flows, with the last one documented in 1936 CE

L'et\ue0\ua0 moderna

Storia di Padova dall'et\ue0 romana al 200