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Se hace un recuento de la cultura del trabajo como algo fundamental de la vida humana la cual se construye socialmente. En ese sentido, se hace un recorrido de los aspectos más importantes desde el punto de vista de las experiencias latinoamericana en la construcción de prácticas culturales, las cuales son reflejo de un legado y una interacción de resitencias ante modelos ideológicos hegemónicos.

Malpositioned implants always result in significant mechanical and aesthetic restorative challenges. This case report describes the correction of position of an unserviceable osseointegrated implant also protruding into the maxillary sinus cavity. This surgical technique facilitated the relocation of an implant-bony segment into a more favorable aesthetic and biomechanical position in a single stage surgery.

In some shipwrecks we can recognize factors such as units of measurement, use of segments and arcs, and repetition of shapes, which may have been rationalised during the transition from craft shipbuilding to a formal design process. This is an a posteriori assessment, as we do not know how hull-shapes were planned and controlled in Antiquity. However the Cheops boat, and the Madrague de Giens, Anse des Laurons II, Fiumicino 4 and Yassi Ada II wrecks, display measurements and geometries suggesting rational approaches to hull-moulding, with principles common to those of medieval and Renaissance shipbuilding and the traditional Mediterranean garbi. © 2012 The Author

A recent hypothesis on the giant ship Syrakosia, built around 235 B.C under the rule of Jeron II of Syracuse, is presented. In this enterprise Archimedes was a minister or a supervisor of the architect (Archias from Corinth). Comparison is made about opinions on the possibilities Archimedes could have had to plan the ship and to foresee her stability properties. The reconstruction of the actual procedures available to him to evaluate volumes and centres of buoyancy of different solids is studied also with models of the volumes of the ship and of the geometric solids mentioned in the “Floating bodies”, to conclude that he could evaluate the stability properties on a quantitative basis only for the orthoconoid, the features of which were exhaustively studied in previous Archimedes’ works. Therefore he must have left to the architect the task of both planning and evaluating empirically the stability of the ship. The last propositions of the first book of the “Floating bodies” suggest that Archimedes may have taken the experience of the Syrakosia as a guideline to approach the problem of stability of sectors of spheres, as the ship was launched when the hull reached the floating line and then she was completed afloat. Stability features of these phases appear to be comparable to those of different portions of sectors of the same sphere as presented by Archimedes.

SOMMARIO Le zattere dell' antichita sono documentate solo da raffigurazioni e da fonti letterarie, che trovano una continuazione nei foderi, zattere, zatteroni e fassoni tradizionali, tra la Campania, la Toscana e la Sardegna. In Campania ed in Sardegna si ha la conferma della evoluzione tecnica ha originato le barche tradizionali dei laghi Trasimeno, di Bracciano e di Bolsena e le bufale maremmane; sulla base di questi criteri costruttivi appare derivata dalle zattere la barca dipinta da A. Lorenzetti(1338–40) ed una della veduta di Firenze del 1470, mentre tale derivazione e ipotizzabile per una terra-cotta di Vulci e per due bronzetri sardi (VII sic.a.C.). Le piroghe monossili rinvenute sono databili tra I'VII sec.a.C. ed il 1200 (Furbara, Bientina, Nemi, Trasimeno), ma illustrazioni rinascimentali ed ottocentesche, fino agli ultimi ricordi della tradizione mostrano una maggiore continuita d-impiego e di tipi. Dalle monossili appaiono sviluppate le barche tradizionali di Posta Fibreno, di Nemi e di Pie...