A first look at equid “idols” from Tepecik-Ciftlik, southern Cappadocia, Turkey

Desde el año 2000, el profesor Erhan Biçakçi de la Universidad de Estambul, ha dirigido diversas campañas de excavación en el yacimiento arqueológico de Tepeçik-Çiftlik, en la región Niğde, al sur de la Capadocia. Allí se han podido documentar niveles pertenecientes al Neolítico Pre-cerámico, Neolítico Cerámico y Calcolítico Antiguo. Las excavaciones han sacado a la luz un rico conjunto de objetos de hueso datados en el Neolítico y Calcolítico. Una de las características más destacadas de este conjunto es la presencia de aproximadamente 250 “ídolos” de hueso. Estos objetos fueron realizados sobre la primera falange de équidos, aplanando la superficie dorsal y plantar/volar de ésta. Algunos de ellos incluso muestran una decoración mucho más elaborada. Las medidas tomadas en estos huesos indican que las falanges proximales de caballo salvaje (Equus ferus) e hydruntino (Equus hemionus hydruntinus) fueron empleadas para manufacturar estos objetos de hueso. Este artículo ilustrará cómo estos elementos óseos fueron realizados y cómo se distribuyen cronológicamente en el sitio.Excavation at the Pre-Pottery Neolithic, Pottery Neolithic, and Early Chalcolithic site of Tepecik-Çiftlik in the Niğde region of Southern Cappadocia, Turkey have been conducted since 2000 under the direction of Professor Erhan Biçakçi of Istanbul University. The excavations have yielded a rich assemblage of worked bone objects dating to the Neolithic and Chalcolithic Periods. One of the striking features of the assemblage is the presence of approximately 250 bone “idols”. These objects were made by flattening the dorsal and plantar/volar surfaces of equid first phalanges. Some also show more elaborate decoration. Measurements taken on these bones indicate that wild horse (Equus ferus) and hydruntine (Equus hemionus hydruntinus) proximal phalanges were used to produce these bone objects. This paper will illustrate how these how these bone objects were manufactured and how they were distributed chronologically within the site

Oscillatory dynamics of a superconductor vortex lattice in high amplitude ac magnetic fields

In this work we study by ac susceptibility measurements the evolution of the solid vortex lattice mobility under oscillating forces. Previous work had already shown that in YBCO single crystals, below the melting transition, a temporarily symmetric magnetic ac field (e.g. sinusoidal, square, triangular) can heal the vortex lattice (VL) and increase its mobility, but a temporarily asymmetric one (e.g. sawtooth) of the same amplitude can tear the lattice into a more pinned disordered state. In this work we present evidence that the mobility of the VL is reduced for large vortex displacements, in agreement with predictions of recent simulations. We show that with large symmetric oscillating fields both an initially ordered or an initially disordered VL configuration evolve towards a less mobile lattice, supporting the scenario of plastic flow.Comment: 5 pages, 4 figures. To appear in Phys. Rev.

Problematising international placements as a site of intercultural learning

This paper theorises some of the learning outcomes of a three-year project concerning student learning in international social work placements in Malaysia. The problematic issue of promoting cultural and intercultural competence through such placements is examined, where overlapping hegemonies are discussed in terms of isomorphism of social work models, that of the nation state, together with those relating to professional values and knowledge, and the tyrannies of received ideas. A critical discussion of cultural competence as the rationale for international placements is discussed in terms of the development of the graduating social worker as a self-reflexive practitioner. The development of sustainable international partnerships able to support student placement and the issue of non-symmetrical reciprocation, typical of wide socio-economic differentials across global regions, is additionally discussed

Plasticity in current-driven vortex lattices

We present a theoretical analysis of recent experiments on current-driven vortex dynamics in the Corbino disk geometry. This geometry introduces controlled spatial gradients in the driving force and allows the study of the onset of plasticity and tearing in clean vortex lattices. We describe plastic slip in terms of the stress-driven unbinding of dislocation pairs, which in turn contribute to the relaxation of the shear, yielding a nonlinear response. The steady state density of free dislocations induced by the applied stress is calculated as a function of the applied current and temperature. A criterion for the onset of plasticity at a radial location $r$ in the disk yields a temperature-dependent critical current that is in qualitative agreement with experiments.Comment: 11 pages, 4 figure