125 research outputs found

    Networks of equities in financial markets

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    We review the recent approach of correlation based networks of financial equities. We investigate portfolio of stocks at different time horizons, financial indices and volatility time series and we show that meaningful economic information can be extracted from noise dressed correlation matrices. We show that the method can be used to falsify widespread market models by directly comparing the topological properties of networks of real and artificial markets.Comment: 9 pages, 8 figures. Accepted for publication in EPJ

    il volto della morte: le maschere funerarie della sepoltura dei preti morti di Gangi

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    riassunto — Le mummie moderne e il signifcato recondito della doppia sepoltura nelle culture mediterranee moderne sono da tempo ampiamente dibattuti. In questo lavoro si discute di una particolare “collezione” di corpi di ecclesiastici, mummifcati ed esposti in un comune montano madonita della Sicilia, Gangi. I corpi, principalmente risalenti al XIX secolo, mummifcati per colatura come nella tradizione del tempo e vestiti degli abiti talari, sono esposti nel piano sottostante della Chiesa Madre, in quella che nella tradizione è detta la “fossa dei parrini” (fossa dei preti). Le mummie, a differenza di altri siti siciliani e mediterranei, sono altresì corredate di sonetto commemorativo e di maschera mortuaria realizzata in cera fne. L’interesse precipuo del nostro studio si è rivolto proprio a questa particolare manifestazione complessa della doppia sepoltura, che risiede nella rappresentazione del volto. Il lavoro esprime una disamina del concetto di maschera mortuaria nell’antichità e porta alla conclusione che il luogo, per le sue valenze scenografche e per la sofsticatezza della ritualizzazione dovesse essere stato ideato per l’ostentazione e il consolidamento dell’immagine della Chiesa e del suo potere all’interno della piccola società rurale

    Fatal cranial injury in an individual from Messina (Sicily) during the times of the Roman Empire

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    Forensic and archaeological examinations of human skeletons can provide us with evidence of violence. In this paper, we present the patterns of two cranial lesions found on an adult male (T173) buried in a grave in the necropolis ‘Isolato 96’, Messina, Sicily, dating back to the Roman Empire (1st century BC - 1st century AD). The skull reveals two perimortem traumatic lesions, one produced by a sharp object on the right parietal bone and the other one on the left parietal bone, presumably the result of a fall. The interpretation of fracture patterns found in this cranium are an illustration of how forensic approaches can be applied with great benefit to archaeological specimens. 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved

    Osteoradionecrosis of the jaws due to teeth extractions during and after radiotherapy: A systematic review

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    Teeth extractions before or after radiotherapy (RT) could be procedures at high risk for osteoradionecrosis (ORN) onset. This systematic review was performed to investigate the ORN incidence following teeth extractions during and after RT for head and neck (H&N) cancer and to evaluate any other possible risk factor. Methods: This systematic review was conducted according to PRISMA protocol, and the PROSPERO registration number was CRD42018079986. An electronic search was performed on the following search engines: PubMed, Scopus, and Web of Science. A cumulative meta‐analysis was performed. Results: Two thousand two hundred and eighty‐one records were screened, and nine were finally included. This systematic review revealed an ORN incidence of 5.8% (41 patients out of 462, 95% CI = 2.3–9.4); 3 ORN developed in the maxilla. No other clinical risk factors were detected. Conclusion: Post‐RT teeth extractions represent a major risk factor for ORN development, especially in the mandible, with a diminishing trend in the last years. Further research on other possible risk factors might improve this evidence

    Statistical Regularities in ATM: network properties, trajectory deviations and delays

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    One of the key enabler to the productivity and efficiency shift foreseen by SESAR will be the business-trajectory concept. The path to a deep understanding of how this new concept impacts on the future SESAR Air Traffic Management scenario goes through a better understanding of the actual air traffic network, and this will be done in the present paper by analyzing traffic data within the framework of complex network analysis. In this paper we will consider flights trajectory data from the Data Demand Repository database. In a first investigation, we perform a network study of the air traffic infrastructure starting from the airports and then refining our analysis at the level of navigation points in order to understand what are the main features that may help explaining why some nodes of the network happen to be found in the same community, i.e. cluster. In a second investigation we perform a study at the level of flight trajectories with the aim of identify statistical regularities in the spatio-temporal deviations of flights between their planned and actual 4D trajectories

    Morphological variability of upper paleolithic and mesolithic skulls from Sicily

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    Scenarios for the dispersal of Homo sapiens in Southern Europe and in the Mediterranean basin have been uncertain, given the scarceness of osteological samples and the simplicity of the proposed archaeologically-based settlement hypotheses. According to available data, the first anatomically modern humans entered Sicily during the Late Pleistocene, coming from the Italian peninsula. A presumably small Late Epigravettian population colonised coastal sites. Later, North-Western archaeological horizons gave hospitality to a significant Mesolithic expansion. In order to verify a hypothesis of continuity in the peopling of the island, we analyzed Sicilian skulls from the Late Epigravettian site of San Teodoro, Eastern Sicily (AMS14C dated at 14,500 BP) and from the Mesolithic period (14C dated from 9,500 to 8,500 BP) coming from various sites (Uzzo, Molara, Grotta d’Oriente) located on the North Western coast of the island. The aims were to test the biological variability through time within the island as well as to evaluate the relationships of Sicilian Pleistocene hunter-gatherers with Old World populations. We also evaluated the Sicilian Mesolithic uniformity especially between the Uzzo and Grotta d’Oriente sites, given their vicinity and accessibility during the Early Holocene. We applied 3D geometric morphometric methods to assess shape variation as well as geographic and diachronic morphological patterns. All analyzed specimens, plus a comparative sample from the Old World dated from the Upper Paleolithic to recent periods, were transformed in digital images and standard craniofacial landmarks were extracted from the 3D models. Our results underline a high variability among the Mesolithic specimens, as well as a large craniometric distance from the presumed founder Paleolithic settler representatives (San Teodoro specimens) that have closer morphological affinities with other European Upper Paleolithic specimens

    The Harvesting Memories Project: Historical ecology and landscape changes of the Sicani Mountains in Sicily

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    The Harvesting Memories project aims to investigate the historical landscape dynamics in an inner area of the Sicani Mountains district in Western Sicily (Contrada Castro, Corleone-Palermo). The interdisciplinary approach of the project allowed us to combine and integrate methods from different disciplines such as historical ecology, landscape archaeology, archaeobotany and GIS-based spatial analysis. In this paper some results have been summarized. The comparison between land mosaic change during the last 60 years, the relationship between site catchment area and land suitability and the correlation between archaeobotanical and phytosociological data. This approach underlined the relevance of the historical ecology for understanding landscape trajectories and planning strategy of suitable development of rural areas

    An Agent Based Model of Air Traffic Management

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    The WP-E ELSA project aims at developing an empirically grounded agent based model that describes some of the stylized facts observed in the Air Traffic Management of the European airspace. The model itself has two main parts: (i) The strategic layer, focused on the interaction between the Network Manager and the Airline Operators and (ii) the tactical layer, focused on aircraft and controllers behaviour in Air Traffic Control (ATC) sectors. The preliminary results for the strategic layer show that when we have a mixing of re-routing and shifting companies, the overall satisfaction can even increase together with the number of flights, which is an effect not observed when only one type of companies is present. The preliminary results for the tactical layer indicate that when shocks in the system are confined in small areas, the interplay between the re-routing and change of flight level strategies may even lead to trajectory modifications that give smaller average delays as long as the number of shocks increases

    The extensions of gravitational soliton solutions with real poles

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    We analyse vacuum gravitational "soliton" solutions with real poles in the cosmological context. It is well known that these solutions contain singularities on certain null hypersurfaces. Using a Kasner seed solution, we demonstrate that these may contain thin sheets of null matter or may be simple coordinate singularities, and we describe a number of possible extensions through them.Comment: 14 pages, LaTeX, 6 figures included using graphicx; to appear in Gen. Rel. Gra

    Preliminary finite element analysis of the stainless-steel liner of the maintainable test cell concept of IFMIF-DONES

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    The main purpose of IFMIF-DONES facility is to provide a neutron source for irradiating small specimens and producing experimental data of material properties for the construction of DEMO fusion power plant. The Test Cell (TC) of the DONES is a confined and well-shielded room, where the strong irradiation environment is created. The biological shielding of the TC mainly consists of several meters thick concrete walls and shielding plugs, and a stainless-steel liner. The TC liner and the concrete walls are actively cooled by water because of the high volumetric heating coming from nuclear reactions. Although, the TC is designed to be fully functional for the complete life span of the facility, still there is a very low probability of defect of the TC biological shielding due to their exposure of intense neutron and gamma irradiation. Therefore, the original TC configuration, which was a monolithic approach, had to be revised. Due to this reason, at the end of 2019 the project team has changed the TC concept from the monolithic design to the so-called Maintainable TC Concept (MTCC) design, which allows a maintenance possibility in case of unexpected damage
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