38,331 research outputs found
Epidemics with containment measures
(14 pages, 6 figures)(14 pages, 6 figures
Pleistocene plateau ice fields in the High Atlas, Morocco
Large ice fields (>25 kmÂČ ) formed over the Tazaghart and Iouzagner plateaux of the High Atlas, Morocco, during the Late Pleistocene. The plateau ice fields were drained by large valley glaciers forming a series of moraine assemblages. Four moraine units have been mapped and subdivided on the basis of morphostratigraphy and the degree of soil weathering. Soil profile development index (PDI) values indicate that the moraine units are widely separated in time with the oldest moraines deeply weathered and degraded whereas soils are absent on the youngest moraines. The highest moraine unit was formed by a small niche glacier which was present as recently as the mid 20th Century. Pleistocene glaciers are likely to have been associated with wetter conditions than today in addition to colder air temperatures. Combined with ice in neighbouring areas, such as the Toubkal Massif, the SW High Atlas supported some of the largest glaciers in Africa during the Pleistocene. The extent of glaciation with ice exploiting and breaching drainage divides has major implications for landscape development. The evolution of the High Atlas is therefore strongly shaped by glaciation and this is closely intertwined with tectonic, fluvial and slope processes
A nonlinear, data-driven, ANNs-based approach to culture-led development policies in rural areas: The case of Gjakove and Pee districts, Western Kosovo
We develop a computational approach to the analysis of cultural vibrancy and to the role of the cultural and cre-ative sectors in the socio-economic organization of two districts of Western Kosovo, Gjakove and Pee. Our anal-ysis is built on a geolocalized mapping of the cultural activities and facilities, and on the main socio-economic variables for the two districts, and makes use of innovative data analysis techniques: Theory of Impossible Words (TIW), the Topological Weighted Centroid (TWC), and the AutoCM ANN. We find that the dynamics of cul-tural vibrancy of the territory is mainly driven by the competing attraction pulls of the nearby countries of Serbia and Albania, that also form the region's main and often conflicting ethnicities, and that such dynamics are likely to further polarize in the future. We also find that the cultural system plays a marginal role in the territory's socio-economic organization. This situation makes a case for a more active role of cultural policy in shaping future local developmental models in rural areas and in acting as an agent of social cohesion.(c) 2022 Elsevier Ltd. All rights reserved
Constant-angle surfaces in liquid crystals
We discuss some properties of surfaces in R3 whose unit normal has constant angle with an assigned direction field. The constant angle condition can be rewritten as an Hamilton-Jacobi equation correlating the surface and the direction field. We focus on examples motivated by the physics of interfaces in liquid crystals and of layered fluids, and discuss the properties of the constant-angle surfaces when the direction field is singular along a line (disclination) or at a point (hedgehog defect
Fully Automatic and Real-Time Catheter Segmentation in X-Ray Fluoroscopy
Augmenting X-ray imaging with 3D roadmap to improve guidance is a common
strategy. Such approaches benefit from automated analysis of the X-ray images,
such as the automatic detection and tracking of instruments. In this paper, we
propose a real-time method to segment the catheter and guidewire in 2D X-ray
fluoroscopic sequences. The method is based on deep convolutional neural
networks. The network takes as input the current image and the three previous
ones, and segments the catheter and guidewire in the current image.
Subsequently, a centerline model of the catheter is constructed from the
segmented image. A small set of annotated data combined with data augmentation
is used to train the network. We trained the method on images from 182 X-ray
sequences from 23 different interventions. On a testing set with images of 55
X-ray sequences from 5 other interventions, a median centerline distance error
of 0.2 mm and a median tip distance error of 0.9 mm was obtained. The
segmentation of the instruments in 2D X-ray sequences is performed in a
real-time fully-automatic manner.Comment: Accepted to MICCAI 201
Toward a precision, complexity-informed cultural policy design: Structural bottlenecks to culture-led development in Skaraborg, Sweden
We analyze the spatial-temporal dynamics of cultural vibrancy in the Swedish sub-region of Skaraborg. Our database consists of 4170 geo-localized cultural activities and facilities, mapped between October 2013 and March 2014. We make use of the TWC methodology for the dynamic simulation of the evolution of geo-localized activity starting from an observed distribution of events, and of the AutoCM ANN architecture to understand how cultural variables are related to the rest of the Skaraborg socio-economy. We find that cultural vibrancy in Skaraborg is likely characterized by a 'flaring' pattern of initial, widespread activity followed by a re-concentration into the main local urban hubs. The deep reason behind this unsuccessful developmental trajectory is the lack of centrality of cultural production in the local socio-economy, and of integration across cultural production sectors. This is in turn due also to structural bottlenecks of a non-cultural nature such as insufficient access of women to higher education. We make a case for the necessity to develop a new precision cultural policy design approach founded upon the science of complexity for both policy design and assessment, and we provide and illustrate a first technical toolkit to this purpose.(c) 2022 Elsevier B.V. All rights reserved
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