270 research outputs found

    The Cretaceous Continental Intercalaire in central Algeria: subsurface evidence for a fluvial to aeolian transition and implications for the onset of aridity on the Saharan Platform.

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    The Lower Cretaceous Continental Intercalaire of North Africa is a terrestrial to shallow marine continental wedge deposited along the southern shoreline of the Neotethys Ocean. Today it has a wide distribution across the northern Sahara where it has enormous socio-economic importance as a major freshwater aquifer. During the Early Cretaceous major north-south trending basement structures were reactivated in response to renewed Atlantic rifting and in Algeria, faults along the El Biod-Hassi Messaourd Ridge appear to have been particularly important in controlling thickness patterns of the Lower Cretaceous Continental Intercalaire. Subsurface data from the Krechba gas field in Central Algeria shows that the Lower Cretaceous stratigraphy is subdivided into two clear parts. The lower part (here termed the In Salah Formation) is a 200 m thick succession of alluvial deposits with large meandering channels, clearly shown in 3D seismic, and waterlogged flood basins indicated by lignites and gleyed, pedogenic mudstones. The overlying Krechba Formation is a 500 m thick succession of quartz-dominated sands and sandstones whose microstructure indicates an aeolian origin, confirming earlier observations from outcrop. These interbed with brick red, highly oxidised mudstones representing deposition in temporary lakes or lagoons under an arid climate. The switch from fluvial to aeolian sedimentation at Krechba on the Saharan Platform occurred in the late Aptian and Albian and is thus synchronous to a comparable change observed by previous authors in Lower Cretaceous non-marine deposits of NE Spain. This was probably driven by a combination of sea-level fall and the northward shift of global arid belts into western Neotethys caused by oceanic rifting between Africa and South America

    DATASET2050 D5.1 - Mobility assessment

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    This document provides documentation on the mobility assessment metrics and methods for use within DATASET2050. On the one hand it describes what the key performance areas, attributes, indicators and metrics such as seamlessness, cost, duration, punctuality, comfort, resilience, etc. incorporated into the model are. On the other, it gives details about mobility metric computation, modelling methodology, visualisations used etc

    DATASET2050 D4.1 - Current Supply Profile

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    The purpose of this document, Deliverable 4.1, is to describe the Current Supply Profile for its further use in different threads by the DATASET2050 Horizon 2020 coordination and support action. This deliverable comprises the work conducted in order to define and list the door-to-door mobility supply components, as described in task 4.1. It presents the baseline supply situation with respect to current door-to-door trips within Europe, including an assessment, identification and mode of the mobility services currently available in Europe (airport access/egress times, airport processes times etc.) All the above will allow the DATASET2050 project partners to determine the time required to undertake the current processes involved from leaving the place of origin (the "Door") to the point of arrival at the airport (the "Kerb"), from the Kerb to the moment the passenger has had their boarding card scanned immediately prior to embarkation (the "Gate"). The same approach is used for the Gate-to-Gate processes (including connecting flights and the transfer process), and finally Gate-to-Kerb and Kerb-to-Door. The inherent asymmetries of what are, in principle, symmetric processes have been assessed (e.g.: Door-to-Kerb vs. Kerb-to-Door). D4.1 directly feeds the supply side of the mobility model that will be run in WP5 of DATASET2050

    Caudal–rostral progression of alpha motoneuron degeneration in the SOD1G93A mouse model of amyotrophic lateral sclerosis

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    Mice with transgenic expression of human SOD1G93A are a widely used model of ALS, with a caudal–rostral progression of motor impairment. Previous studies have quantified the progression of motoneuron (MN) degeneration based on size, even though alpha (α-) and gamma (γ-) MNs overlap in size. Therefore, using molecular markers and synaptic inputs, we quantified the survival of α-MNs and γ-MNs at the lumbar and cervical spinal segments of 3- and 4-month SOD1G93A mice, to investigate whether there is a caudal–rostral progression of MN death. By 3 months, in the cervical and lumbar spinal cord, there was α-MN degeneration with complete γ-MN sparing. At 3 months, the cervical spinal cord had more α-MNs per ventral horn than the lumbar spinal cord in SOD1G93A mice. A similar spatial trend of degeneration was observed in the corticospinal tract, which remained intact in the cervical spinal cord at 3- and 4- months of age. These findings agree with the corticofugal synaptopathy model that α-MNs and CST of the lumbar spinal cord are more susceptible to degeneration in SOD1G93A mice. Hence, there is a spatial and temporal caudal–rostral progression of α-MN and CST degeneration in SOD1G93A mice

    Plasma-polymerized pericyte patches improve healing of murine wounds through increased angiogenesis and reduced inflammation

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    Pericytes have the potential to be developed as a cell therapy for the treatment of wounds; however, the efficacy of any cell therapy relies on the successful delivery of intact and functioning cells. Here, the effect of delivering pericytes on wound repair was assessed alongside the development of a surface-functionalized pericyte patch. Plasma polymerization (PP) was used to functionalize the surface of silicone patches with heptylamine (HA) or acrylic acid (AA) monomers. Human pericytes were subsequently delivered to murine excisional wounds by intradermal injection or using the pericyte-laden patches and the comparative effects on wound healing, inflammation and revascularization determined. The AA surface provided the superior transfer of the cells to de-epidermized dermis. Excisional murine wounds treated either with pericytes injected directly into the wound or with the pericyte-laden AA patches showed improved healing with decreased neutrophil infiltration and reduced numbers of macrophages in the wounds. Pericyte delivery also enhanced angiogenesis through a mechanism independent of VEGF signalling. Pericytes, when delivered to wounds, improved healing responses by dampening inflammation and promoting angiogenesis. Delivery of pericytes using PP-AA-functionalized patches was equally as effective as direct injection of pericytes into wounds. Pericyte-functionalized dressings may therefore be a clinically relevant approach for the treatment of wounds.Hannah M. Thomas, Parinaz Ahangar, Robert Fitridge, Giles T.S. Kirby, Stuart J. Mills and Allison J. Cowi

    Temporal variations in Holocene slip rate along the central Garlock fault, Pilot Knob Valley, California

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    Average geologic slip rates along the central Garlock fault, in eastern California, are thought to have been relatively steady at 5-7 mm/yr since at least the Late Pleistocene, yet present-day rates inferred from geodetic velocity fields are indistinguishable from zero. We evaluate the possibility of non-steady slip over millennial timescales using displaced Late Holocene alluvium along the central Garlock fault in Pilot Knob Valley. Truncation of a Late Holocene alluvial fan deposit against a shutter ridge requires a minimum of 30-37 m of displacement since deposition of the fan; maximum allowable displacement is 43-50 m. The extent of soil development atop the fan surface and optically stimulated luminescence ages bracket fan deposition between 3.5 and 4.5 ka. Together, these data require that slip rates during the Late Holocene were ̃7-14 mm/yr, with a preferred rate of ̃11-13 mm/yr. Our results, in conjunction with previous estimates of displacement over the past ̃15 ka, require significant temporal variations in strain release along the Garlock fault and confirm previous suggestions that interactions among fault systems in eastern California give rise to alternating periods of fault activity and quiescence

    Theoretical study of the absorption spectra of the sodium dimer

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    Absorption of radiation from the sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X Sigma-g+ state to the first excited singlet A Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the first excited triplet b Sigma-g+ and triplet c Pi-g states are studied quantum-mechanically. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from ab initio calculations, spectroscopy, and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 500 to 3000 K and are compared with previous calculations and measurements where available.Comment: 19 pages, 8 figures, revtex, eps
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