Search results for "560"
showing 10 items of 630 documents
Chemical composition of modern and fossil Hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 1: M…
2012
Bioapatite in mammalian teeth is readily preserved in continental sediments and represents a very important archive for reconstructions of environment and climate evolution. This project provides a comprehensive data base of major, minor and trace element and isotope tracers for tooth apatite using a variety of microanalytical techniques. The aim is to identify specific sedimentary environments and to improve our understanding on the interaction between internal metabolic processes during tooth formation and external nutritional control and secondary alteration effects. Here, we use the electron microprobe to determine the major and minor element contents of fossil and modern molar enamel, …
Photovoltaic plant array reconfiguration: Design of a new device
2014
An efficient strategy to improve unequally irradiated PV plants performances is based on the reconfiguration of the connections between the modules. In this paper, an algorithm, for this purpose conceived, is presented. Moreover, the design, realization and finally also the set up of a new reconfiguration system device is fully shown and discussed. The algorithm conceived simulates several possible series-parallel connections under varying irradiation conditions, and determines the optimal modules connection in order to get the maximum output power. In this way, the reconfiguration system may set up the reconfiguration strategy. The reconfiguration system prototype set up, basically consist…
Echi dal mondo antico nel racconto della natività: il Protoevangelium Jacobi e il Liber de nativitate Salvatoris
2018
La sociedad y el espacio público
2019
El espacio público y los actos de la propia sociedad, ¿hasta dónde llega el límite de unos para que comience el derecho de los otros? Son muchas las actuaciones que se suceden en la vía pública y que tienen una repercusión, en la mayoría de los casos, negativa para el paisaje urbano. En esta fina línea, entre la preservación del paisaje urbano y los derechos que la ley confiere a los ciudadanos, se enmarcan las ordenanzas de convivencia ciudadana como el mecanismo adecuado que normativice las conductas que inciden en el espacio público. Se juzga imprescindible analizar las normas de convivencia que presiden nuestro país, a fin de dar con soluciones ecuánimes que garanticen la viabilidad de …
The last of the large-sized tortoises of the Mediterranean islands
2022
Altres ajuts: CERCA Programme/Generalitat de Catalunya Altres ajuts: Operational Programme Research, Development and Education Project (CZ.02.2.69/0.0/0.0/16_027/0008360) Archaeological investigations carried out in the cave Zubbio di Cozzo San Pietro, Bagheria, Sicily, revealed the presence of a few skeletal elements of a large-sized tortoise in a funerary area dating to the Copper/Bronze Age. The tortoise has been AMS-dated revealing an age of 12.5 ± 0.5 kyr BP and therefore it pre-dates the funerary activities. The morphology of the retrieved skeletal elements differs from that of the only native tortoise currently living in Sicily, Testudo hermanni. The tortoise's size significantly exc…
Gastropod evidence against the Early Triassic Lilliput effect
2010
4 pages; International audience; Size reduction in the aftermath of the Permian-Triassic mass extinction event has repeatedly been described for various marine organisms, including gastropods (the Lilliput effect). A Smithian gastropod assemblage from Utah, USA, reveals numerous large-sized specimens of different genera as high as 70 mm, the largest ever reported from the Early Triassic. Other gastropods reported from Serbia and Italy are also as large as 35 mm. Size frequency distributions of the studied assemblages indicate that they were not unusually small when compared with later Mesozoic and modern faunas. The occurrence of large-sized gastropods less than 2 Ma after the Permian-Trias…
Post-mortem enamel surface texture alteration during taphonomic processes—do experimental approaches reflect natural phenomena?
2022
Experimental approaches are often used to better understand the mechanisms behindand consequences of post-mortem alteration on proxies for diet reconstruction.Dental microwear texture analysis (DMTA) is such a dietary proxy, using dental wearfeatures in extant and extinct taxa to reconstruct feeding behaviour and mechanicalfood properties. In fossil specimens especially, DMTA can be biased by post-mortemalteration caused by mechanical or chemical alteration of the enamel surface. Herewe performed three different dental surface alteration experiments to assess the effectof common taphonomic processes by simplifying them: (1) tumbling in sedimentsuspension to simulate fluvial transport, (2) s…
A new Meckel's cartilage from the Devonian Hangenberg black shale in Morocco and its position in chondrichthyan jaw morphospace.
2022
Fossil chondrichthyan remains are mostly known from their teeth, scales or fin spines only, whereas their cartilaginous endoskeletons require exceptional preservational conditions to become fossilized. While most cartilaginous remains of Famennian (Late Devonian) chondrichthyans were found in older layers of the eastern Anti-Atlas, such fossils were unknown from the Hangenberg black shale (HBS) and only a few chondrichthyan teeth had been found therein previously. Here, we describe a Meckel’s cartilage from the Hangenberg black shale in Morocco, which is the first fossil cartilage from these strata. Since no teeth or other skeletal elements have been found in articulation, we used elliptica…
Comment on "Lethally hot temperatures during the Early Triassic greenhouse".
2013
Sun et al . (Reports, 19 October 2012, p. 366) reconstructed Permian to Middle Triassic equatorial seawater temperatures. After correct temporal positioning of their data points, their presumed trends of temperature changes, and hence their assumption of a one-to-one relationship between putative "lethally hot" seawater temperatures and a disputable equatorial "eclipse" of some organisms, are no longer supported by their data.
Economising failure and assembling a failure regime
2023
Sociologists have largely neglected the topic of failure, and particularly the economising of failure, notwithstanding notable exceptions. This is puzzling, given the many adjacent literatures that have addressed the practices and processes of economising. Four features define our approach. First, it is argued that failure has none of the objectivity or inevitability often attributed to it. Second, it is suggested that failure be viewed as a variable ontology object. Third, attention is directed to the calculative infrastructures that operationalise the ideas of failing and failure, and enable them to be acted upon. Fourth, emphasis is placed on the importance of distinguishing between fail…