679 research outputs found
Elaia, Pergamon's maritime satellite:The rise and fall of an ancient harbour city shaped by shoreline migration
Throughout human history, communication and trade have been key to society. Because maritime trade facilitated the rapid transportation of passengers and freight at relatively low cost, harbours became hubs for traffic, trade and exchange. This general statement holds true for the Pergamenian kingdom, which ruled wide parts of today's western Turkey during Hellenistic times. Its harbour, located at the city of Elaia on the eastern Aegean shore, was used extensively for commercial and military purposes. This study reconstructs the coastal evolution in and around the ancient harbour of Elaia and compares the observed environmental modifications with archaeological and historical findings. We use micropalaeontological, sedimentological and geochemical proxies to reconstruct the palaeoenvironmental dynamics and evolution of the ancient harbour. The geoarchaeological results confirm the archaeological and historical evidence for Elaia's primacy during Hellenistic and early Roman times, and the city's gradual decline during the late Roman period. Furthermore, our study demonstrates that Elaia holds a unique position as a harbour city during ancient times in the eastern Aegean region, because it was not greatly influenced by the high sediment supply associated with river deltas. Consequently, no dredging of the harbour basins is documented, creating exceptional geo-bioarchives for palaeoenvironmental reconstructions
IUPAC-NIST solubility data series. 81. Hydrocarbons with water and seawater-revised and updated. Part 5. C7 hydrocarbons with water and heavy water
The mutual solubility and related liquid-liquid equilibria of C7 hydrocarbons with water and heavy water are exhaustively and critically reviewed. Reports of experimental determination of solubility in 23 chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For 9 systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of the all experimental data for a given homologous series of aliphatic and aromatic hydrocarbons was used
IUPAC-NIST solubility data series. 81. Hydrocarbons with water and seawater - Revised and updated. Part 8. C9 hydrocarbons with water
The mutual solubility and related liquid-liquid equilibria of C9 hydrocarbons with water are exhaustively and critically reviewed. Reports of the experimental determination of solubility in 18 chemically distinct binary systems that appeared in the primary literature prior to the end of 2002 are compiled. For 8 systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction, as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Date Series, a new method based on the evaluation of the all experimental data for a given homologous series of aliphatic and aromatic hydrocarbons was used
Description in occam and simulation on a transputer network of a systolic processor for image processing
The most significant drawback in using neighbourhood processing (linear filtering, morphology) is the cost of ils
implementation, particularly in the area of image processing where the cost grows in proportion to the kernel size squared .
However, in PIR [1] it was shown that a large amount of classical algorithms could be described as a cascade of peculiar
elementary tells. Being highly integrable, these tells brought about the design of a neighbourhood systolic processor.
Converting a functional description (e .g . flow graph, mathematical model) into a hardware structure raises several technical
problems . In addition, the cost of designing an integrated circuit requires special cure, making it necessary to perform many
simulations .
The first part of this paper gives a short description of the décomposition method. It then goes on ta describe the power of
occam as a design formalism, applying it to the cascaded tells modelisation . Furthermore, the obtained model can be compiled
into a code directly loadable into a Transputer network, resulting in a performant simulation . The hierarchy of occam allows a
description at différent levels of abstraction, in order to fit the precision of the model to the desired type of simulation .L'inconvénient majeur des algorithmes de voisinage (filtrage linéaire, morphologique) réside dans le coût associé à leur mise
en oeuvre, principalement dans le domaine du traitement d'images où il croît avec le carré de la taille du voisinage . Il a
toutefois été montré dans PIR [1] que de nombreux algorithmes couramment utilisés pouvaient être décrits sous la forme
d'une cascade de cellules élémentaires particulières . Le caractère hautement intégrable de ces cellules nous a amené à
concevoir un processeur systolique de voisinage basé sur le principe de la synthèse par cascades de cellules .
Le passage d'une représentation fonctionnelle (graphe de fluence, modèle mathématique) à une structure matérielle soulève
un certain nombre de problèmes . En outre, le coût lié à la réalisation d'un circuit intégré exige une extrême prudence,
imposant généralement le recours à de nombreuses simulations .
Le présent papier fournit un bref aperçu de la méthode de synthèse par cascades de cellules . Il montre ensuite la puissance
du langage occam comme outil de formalisation appliquant celui-ci à la modélisation des cascades de cellules . La
compilation du modèle au moyen d'outils adéquats fournit un code directement exécutable par un réseau de Transputers, ce
qui conduit à une simulation performante . La hiérarchie incluse dans le langage permet une décomposition en niveaux
d'abstraction de plus en plus fins, en vue d'ajuster la précision du modèle au type de simulation désiré
Quantum entanglement and information processing via excitons in optically-driven quantum dots
We show how optically-driven coupled quantum dots can be used to prepare
maximally entangled Bell and Greenberger-Horne-Zeilinger states. Manipulation
of the strength and duration of the selective light-pulses needed for producing
these highly entangled states provides us with crucial elements for the
processing of solid-state based quantum information. Theoretical predictions
suggest that several hundred single quantum bit rotations and Controlled-Not
gates could be performed before decoherence of the excitonic states takes
place.Comment: 3 separate PostScript Figures + 7 pages. Typos corrected. Minor
changes added. This updated version is to appear in PR
The Late Neandertal permanent lower left third premolar from Walou Cave (Trooz, Belgium) and its context
Objectives
We describe a hominin permanent lower left third premolar unearthed in 1997 at Walou Cave (Belgium), found in direct association with a Mousterian lithic industry, in a layer directly dated to 40–38,000 years BP.
Materials and methods
The taxonomical attribution of the tooth is addressed through comparative morphometric analyses, and stable isotope analyses aimed at determining the diet of the individual.
Results
The Walou P3 plots within the Neandertal range of variation and is significantly different from recent modern humans in all morphometric assessments. The isotope data showed that like other Neandertals, the Walou individual acquired its dietary proteins primarily from terrestrial food sources.
Discussion
We discuss the implications of the existence of a clearly Neandertal premolar dating to the period of the Middle to Upper Paleolithic transition in the Meuse river basin
Digenic inheritance of human primary microcephaly delineates centrosomal and non-centrosomal pathways.
Primary microcephaly (PM) is characterized by a small head since birth and is vastly heterogeneous both genetically and phenotypically. While most cases are monogenic, genetic interactions between Aspm and Wdr62 have recently been described in a mouse model of PM. Here, we used two complementary, holistic in vivo approaches: high throughput DNA sequencing of multiple PM genes in human patients with PM, and genome-edited zebrafish modeling for the digenic inheritance of PM. Exomes of patients with PM showed a significant burden of variants in 75 PM genes, that persisted after removing monogenic causes of PM (e.g., biallelic pathogenic variants in CEP152). This observation was replicated in an independent cohort of patients with PM, where a PM gene panel showed in addition that the burden was carried by six centrosomal genes. Allelic frequencies were consistent with digenic inheritance. In zebrafish, non-centrosomal gene casc5 -/- produced a severe PM phenotype, that was not modified by centrosomal genes aspm or wdr62 invalidation. A digenic, quadriallelic PM phenotype was produced by aspm and wdr62. Our observations provide strong evidence for digenic inheritance of human PM, involving centrosomal genes. Absence of genetic interaction between casc5 and aspm or wdr62 further delineates centrosomal and non-centrosomal pathways in PM
Networks or structures? : organizing cultural routes around heritage values : case studies from Poland
The most common way of managing cultural heritage recently takes form of cultural routes as they seem to offer a new model of participation in culture to their recipients; they are often a peculiar anchor point for inhabitants to let them understand their identity and form the future; they offer actual tours to enter into interaction with culture and history, to build together that creation of the heritage, which so is becoming not only a touristic product, but, first of all, the space for cultural, social and civic activity. Yet, so far, according to what we know, the research problem concerning the method of cultural route organization (points on the route) into solid structures or more of the networked nature, has not been deliberated. A question arises, what values are brought by routes and how to organize routes to be the carriers of the values important for communities, where routes are functioning. And, as a consequence, if, from the point of view of the values of local communities, organizing solid route structures or organizing more widely-spaced, network-based routes would bring effects and what those effects would be. Thus, the posed question is of course scientifically imprecise because a network is a type of structure but presents a given direction for the development of cultural route structures. Our objective here is to present a certain solidity and rigidity of structure with dynamic and smooth understanding of the network. The research presented in the article is based on 3 case studies. We have selected for this purpose the three largest cultural routes in Poland, organized to various degrees. The outcome of the research was referred also to other cultural route organization research
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