484 research outputs found

    Advanced visual rendering, gesture-based interaction and distributed delivery for immersive and interactive media services

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    The media industry is currently being pulled in the often-opposing directions of increased realism (high resolution, stereoscopic, large screen) and personalisation (selection and control of content, availability on many devices). A capture, production, delivery and rendering system capable of supporting both these trends is being developed by a consortium of European organisations including partners from the broadcast, film, telecoms and academic sectors, in the EU-funded FascinatE project. This paper reports on the latest project developments in the delivery network and end-user device domains, including advanced audiovisual rendering, computer analysis and scripting, content-aware distributed delivery and gesture-based interaction. The paper includes an overview of existing immersive media services and concludes with initial service concept descriptions and their market potential.Peer ReviewedPreprin

    Salinity control on Na incorporation into calcite tests of the planktonic foraminifera Trilobatus sacculifer – Evidence from culture experiments and surface sediments

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    The quantitative reconstruction of past seawater salinity has yet to be achieved and the search for a direct and independent salinity proxy is ongoing. Recent culture and field studies show a significant positive correlation of Na/Ca with salinity in benthic and planktonic foraminiferal calcite. For accurate paleoceanographic reconstructions, consistent and reliable calibrations are necessary, which are still missing. In order to assess the reliability of foraminiferal Na/Ca as a direct proxy for seawater salinity, this study presents electron microprobe Na/Ca data, measured on cultured specimens of Trilobatus sacculifer. The culture experiments were conducted over a wide salinity range of 26 to 45, while temperature was kept constant. To further understand potential controlling factors of Na incorporation, measurements were also performed on foraminifera cultured at various temperatures in the range of 19.5 °C to 29.5 °C under constant salinity conditions. Foraminiferal Na/Ca ratios positively correlate with seawater salinity (Na/Caforam = 0.97 + 0.115 ⋅ Salinity, R = 0.97, p < 0.005). Temperature on the other hand exhibits no statistically significant relationship with Na/Ca ratios indicating salinity to be the dominant factor controlling Na incorporation. The culturing results are corroborated by measurements on T. sacculifer from Caribbean and Gulf of Guinea surface sediments. In conclusion, planktonic foraminiferal Na/Ca can be applied as a reliable proxy for reconstructing sea surface salinities, albeit species-specific calibrations might be necessary

    On the sedimentological origin of down-core variations of bulk sedimentary nitrogen isotope ratios

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    Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA2009, doi:10.1029/2004PA001081.The bulk sedimentary nitrogen isotopic composition of two cores from nearby sites on the northern slope of the South China Sea (Site 17940 and Ocean Drilling Program (ODP) Site 1144) differs by up to >2‰ during the last glacial period. Given their close proximity, both core sites are located in the same biogeographic zone and nutrient regime, and it is thus unlikely that this offset is due to a true gradient in surface ocean conditions. In an attempt to resolve this offset, we have investigated the possible effects of two sedimentological parameters that can affect bulk sedimentary δ15N, namely, the variable contribution of inorganic N to bulk N in the sediment and the grain-size dependence of bulk δ15N. We find that neither effect, singly or in combination, is sufficient to explain the significant δ15N offset between the two down-core records. By elimination the most likely explanation for the observed discrepancy is a different origin of both the organic and inorganic nitrogen at each site. This study adds to the growing body of evidence highlighting the complex nature and origin of the sedimentary components in sediment drifts, such as ODP Site 1144.Funding from NSERC Canada (to S.E.C. and M.K.) and NSF (OCE-0214365 and OCE-0318371 to M.J.H. and OCE-0327405 to T.I.E.) is gratefully acknowledged, as well as Woods Hole Oceanographic Institution Postdoctoral Fellowships (M.K. and G.M.), the Camille and Henry Dreyfus Postdoctoral Program in Environmental Chemistry (M.J.H.), and a Geological Society of America student research grant (M.K.)

    Carbonates from the ancient world's longest aqueduct:A testament of Byzantine water management

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    The fourth‐ and fifth‐century aqueduct system of Constantinople is, at 426 km, the longest water supply line of the ancient world. Carbonate deposits in the aqueduct system provide an archive of both archaeological developments and palaeo‐environmental conditions during the depositional period. The 246‐km‐long aqueduct line from the fourth century used springs from a small aquifer, whereas a 180‐km‐long fifth‐century extension to the west tapped a larger aquifer. Although historical records testify at least 700 years of aqueduct activity, carbonate deposits in the aqueduct system display less than 27 years of operation. This implies that the entire system must have been cleaned of carbonate, presumably during regular campaigns. A 50‐km‐long double‐aqueduct section in the central part of the system may have been a costly but practical solution to allow repairs and cleaning of the aqueducts of carbonate to ascertain a continuous water supply to the city. The fifth‐century channel was commonly contaminated with clay, caused by the nature of the aqueduct system and possible local damage to the channel. This clay‐rich water could have been one of the reasons for the construction of large reservoirs in Constantinople. imageLeverhulme Trust http://dx.doi.org/10.13039/501100000275Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/50110000165

    The Functional DRD3 Ser9Gly Polymorphism (rs6280) Is Pleiotropic, Affecting Reward as Well as Movement

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    Abnormalities of motivation and behavior in the context of reward are a fundamental component of addiction and mood disorders. Here we test the effect of a functional missense mutation in the dopamine 3 receptor (DRD3) gene (ser9gly, rs6280) on reward-associated dopamine (DA) release in the striatum. Twenty-six healthy controls (HCs) and 10 unmedicated subjects with major depressive disorder (MDD) completed two positron emission tomography (PET) scans with [11C]raclopride using the bolus plus constant infusion method. On one occasion subjects completed a sensorimotor task (control condition) and on another occasion subjects completed a gambling task (reward condition). A linear regression analysis controlling for age, sex, diagnosis, and self-reported anhedonia indicated that during receipt of unpredictable monetary reward the glycine allele was associated with a greater reduction in D2/3 receptor binding (i.e., increased reward-related DA release) in the middle (anterior) caudate (p<0.01) and the ventral striatum (p<0.05). The possible functional effect of the ser9gly polymorphism on DA release is consistent with previous work demonstrating that the glycine allele yields D3 autoreceptors that have a higher affinity for DA and display more robust intracellular signaling. Preclinical evidence indicates that chronic stress and aversive stimulation induce activation of the DA system, raising the possibility that the glycine allele, by virtue of its facilitatory effect on striatal DA release, increases susceptibility to hyperdopaminergic responses that have previously been associated with stress, addiction, and psychosis

    Woodlands and steppes: Pleistocene vegetation in Yakutia's most continental part recorded in the Batagay permafrost sequence

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    © 2018 Elsevier Ltd Based on fossil organism remains including plant macrofossils, charcoal, pollen, and invertebrates preserved in syngenetic deposits of the Batagay permafrost sequence in the Siberian Yana Highlands, we reconstructed the environmental history during marine isotope stages (MIS) 6 to 2. Two fossil assemblages, exceptionally rich in plant remains, allowed for a detailed description of the palaeo-vegetation during two climate extremes of the Late Pleistocene, the onset of the last glacial maximum (LGM) and the last interglacial. In addition, altogether 41 assemblages were used to outline the vegetation history since the penultimate cold stage of MIS 6. Accordingly, meadow steppes analogue to modern communities of the phytosociological order Festucetalia lenensis formed the primary vegetation during the Saalian and Weichselian cold stages. Cold-resistant tundra-steppe communities (Carici rupestris-Kobresietea bellardii) as they occur above the treeline today were, in contrast to more northern locations, mostly lacking. During the last interglacial, open coniferous woodland similar to modern larch taiga was the primary vegetation at the site. Abundant charcoal indicates wildfire events during the last interglacial. Zoogenic disturbances of the local vegetation were indicated by the presence of ruderal plants, especially by abundant Urtica dioica, suggesting that the area was an interglacial refugium for large herbivores. Meadow steppes, which formed the primary vegetation during cold stages and provided potentially suitable pastures for herbivores, were a significant constituent of the plant cover in the Yana Highlands also under the full warm stage conditions of the last interglacial. Consequently, meadow steppes occurred in the Yana Highlands during the entire investigated timespan from MIS 6 to MIS 2 documenting a remarkable environmental stability. Thus, the proportion of meadow steppe vegetation merely shifted in response to the respectively prevailing climatic conditions. Their persistence indicates low precipitation and a relatively warm growing season throughout and beyond the late Pleistocene. The studied fossil record also proves that modern steppe occurrences in the Yana Highlands did not establish as late as in the Holocene but instead are relicts of a formerly continuous steppe belt extending from Central Siberia to Northeast Yakutia during the Pleistocene. The persistence of plants and invertebrates characteristic of meadow steppe vegetation in interior Yakutia throughout the late Quaternary indicates climatic continuity and documents the suitability of this region as a refugium also for other organisms of the Pleistocene mammoth steppe including the iconic large herbivores

    Разработка импульсной системы питания сварочной дуги на базе искусственной формирующей линии

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    Объектом исследования является импульсная система питания сварочной дуги, горящей в динамическом режиме. Предмет исследования – система импульсного питания сварочной дуги на базе искусственной формирующей линии неплавящимся электродом. Цель работы – анализ и разработка импульсной системы питания сварочной дуги на базе искусственной формирующей линии неплавящимся электродом в аргоне. Создана действующая экспериментальная установка для сварки дугой горящей в динамическом режиме с униполярными импульсами. Достоверность результатов и выводов подтверждена их сходимостью с экспериментальными данными, полученными методом осциллографированияSubject of research – power system for welding in dynamic mode nonconsumable electrode unidirectional pulses of current. Purpose of research – research and development of the power system for non-consumable electrode arc welding in argon in dynamic mode. The acting experimental setup for non-consumable electrode arc welding in argon in dynamic mode was created. The validity of results and inferences was confirmed by their convergence with experimental data obtained by oscillographic testing of developed power system for non-consumable electrode arc welding in argon in dynamic mode

    The sinus tarsi approach in displaced intra-articular calcaneal fractures: a systematic review

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    Purpose: Although open reduction and internal fixation is currently considered the gold standard in surgical treatment of displaced intra-articular calcaneal fractures, various different approaches exist including the limited lateral approach. The aim of this systematic review was to combine the results of studies using the sinus tarsi approach, which is the most frequently applied limited lateral approach. Method: A literature search in the electronic databases of the Cochrane Library and Pubmed Medline, between January 1st 2000 to December 1st 2010, was conducted to identify studies in which the sinus tarsi approach or a modified sinus tarsi approach was utilized for the treatment of displaced intra-articular calcaneal fractures. The methodological quality of the included studies was assessed using the Coleman methodology score. Results: A total of eight case series reporting on 256 patients with 271 calcaneal fractures was identified. Overall good to excellent outcome was reached in three-quarters of all patients. An average complication rate of minor wound complications of 4.1% was reported and major wound complications in 0.7%. The need for a secondary subtalar arthrodesis occurred at an average rate of 4.3%. The average Coleman methodology score was 56.8 (range 39-72) points. Conclusion: The results, i.e. functional outcome and complication rates, of the sinus tarsi approach compare similarly or favourably to the extended lateral approach. Therefore, in the process of tailoring the best treatment modality to the right patient and the right fracture type, the sinus tarsi approach might be a valuable asset

    Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago

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    Past sea-level records provide invaluable information about the response of ice sheets to climate forcing. Some such records suggest that the last deglaciation was punctuated by a dramatic period of sea-level rise, of about 20 metres, in less than 500 years. Controversy about the amplitude and timing of this meltwater pulse (MWP-1A) has, however, led to uncertainty about the source of the melt water and its temporal and causal relationships with the abrupt climate changes of the deglaciation. Here we show that MWP-1A started no earlier than 14,650 years ago and ended before 14,310 years ago, making it coeval with the Bolling warming. Our results, based on corals drilled offshore from Tahiti during Integrated Ocean Drilling Project Expedition 310, reveal that the increase in sea level at Tahiti was between 12 and 22 metres, with a most probable value between 14 and 18 metres, establishing a significant meltwater contribution from the Southern Hemisphere. This implies that the rate of eustatic sea-level rise exceeded 40 millimetres per year during MWP-1A
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