81 research outputs found

    WhiteHaul: an efficient spectrum aggregation system for low-cost and high capacity backhaul over white spaces

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    We address the challenge of backhaul connectivity for rural and developing regions, which is essential for universal fixed/mobile Internet access. To this end, we propose to exploit the TV white space (TVWS) spectrum for its attractive properties: low cost, abundance in under-served regions and favorable propagation characteristics. Specifically, we propose a system called WhiteHaul for the efficient aggregation of the TVWS spectrum tailored for the backhaul use case. At the core of WhiteHaul are two key innovations: (i) a TVWS conversion substrate that can efficiently handle multiple non-contiguous chunks of TVWS spectrum using multiple low cost 802.11n/ac cards but with a single antenna; (ii) novel use of MPTCP as a link-level tunnel abstraction and its use for efficiently aggregating multiple chunks of the TVWS spectrum via a novel uncoupled, cross-layer congestion control algorithm. Through extensive evaluations using a prototype implementation of WhiteHaul, we show that: (a) WhiteHaul can aggregate almost the whole of TV band with 3 interfaces and achieve nearly 600Mbps TCP throughput; (b) the WhiteHaul MPTCP congestion control algorithm provides an order of magnitude improvement over state of the art algorithms for typical TVWS backhaul links. We also present additional measurement and simulation based results to evaluate other aspects of the WhiteHaul design

    Tumoral calcinosis of the foot: An unusual differential diagnosis of calcaneal mass

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    Introduction Tumoral calcinosis (TC) is a rare disorder characterized by the development of calcified masses within the periarticular soft tissues of large joints. It commonly involves the hip, shoulders, and elbows. TC rarely involves the feet. Case presentation In this report, we describe an unusual case of primary TC of the foot in a 76-year-old female and discuss the pathophysiology, diagnosis, and therapeutic interventions of the condition. Discussion Due to the wide range of conditions mimicking TC, its diagnosis could be challenging. Diagnosis of TC is mainly based on the radiographic findings, the patient's biochemical profile, and the medical history plus differentiating the condition from its mimics. Conclusion TC should be considered in the differential diagnosis of any soft tissue calcification. ©2015 Published by Elsevier Ltd. on behalf of Surgical Associates Ltd

    WhiteHaul: white space spectrum aggregation system for backhaul

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    Today almost half the world's population does not have Internet access. This is particularly the case in rural and undeserved regions where providing Internet access infrastructure is challenging and expensive. To this end, we present demonstration of WhiteHaul [5], a low-cost hybrid cross-layer aggregation system for TV White Space (TVWS) based backhaul. WhiteHaul features a custom-designed frequency conversion substrate that efficiently handles multiple noncontiguous chunks of TVWS spectrum using multiple low-cost COTS 802.11n/ac cards but with a single antenna. At the software layer, WhiteHaul uses MPTCP as a link-level tunnel abstraction to efficiently aggregate multiple chunks of the TVWS spectrum via a novel uncoupled, cross-layer congestion control algorithm. This demo illustrates the unique features of the WhiteHaul system based on a prototype implementation employing a modified version of MPTCP Linux Kernel and a custom-designed conversion substrate. Using this prototype, we highlight the performance of the WhiteHaul system under various configurations and network conditions

    Pupil dilation with intracameral lidocaine during phacoemulsification

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    Purpose: To evaluate pupil dilation by an intracameral injection of nonpreserved lidocaine 1 during phacoemulsification cataract extraction and compare the results with those using conventional topical mydriatics. Setting: Department of Ophthalmology, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Methods: A prospective comparative case series study was conducted. The study included 57 patients who were given topical mydriatics (30 eyes) or intracameral lidocaine (27 eyes) to dilate the pupil for phacoemulsification and intraocular lens implantation. The topical group received 3 drops of cyclopentolate 1 and phenylephrine 5 given 5 minutes apart starting 60 minutes before surgery. The intracameral group received preservative-free lidocaine 1 (0.2 to 0.3 mL) injected just before the procedure began. No epinephrine was added to the irrigating solution. In both groups, the horizontal pupil diameter was measured before and after pupil dilation using the same caliper. Total surgical time, need for a mydriatic agent during the procedure, and subjective surgical performance were recorded. Results: The mean age, sex, cataract density, baseline horizontal pupil diameter, and mean duration of the surgery were the same between the topical group and intracameral group. The mean pupil dilation was 4.52 mm ± 0.08 (SD) in the intracameral group and 4.06 ± 0.09 mm in the topical group; the difference between groups was statistically significant (P = .001). There was no significant difference between groups in the overall subjective surgical performance (P = .74). No patient in the intracameral group and 2 patients in the topical group required an intracameral mydriatic injection. Conclusion: During phacoemulsification, intracameral preservative-free lidocaine 1 provided rapid, effective mydriasis comparable that of topical mydriatics. © 2007 ASCRS and ESCRS

    Programmable Edge-to-Cloud Virtualization for 5G Media Industry: The 5G-MEDIA Approach

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    To ensure high Quality of Experience (QoE) for end users, many media applications require significant quantities of computing and network resources, making their realization challenging in resource constrained environments. In this paper, we present the approach of the 5G-MEDIA project, providing an integrated programmable service platform for the development, design and operations of media applications in 5G networks, facilitating media service management across the service life cycle. The platform offers tools to service developers for efficient development, testing and continuous correction of services. One step further, it provides a service virtualization platform offering horizontal services, such as a Media Service Catalogue and accounting services, as well as optimization mechanisms to flexibly adapt service operations to dynamic conditions with efficient use of infrastructure resources. The paper outlines three use cases where the platform was tested and validated

    Predicting no-show medical appointments using machine learning

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    Health care centers face many issues due to the limited availability of resources, such as funds, equipment, beds, physicians, and nurses. Appointment absences lead to a waste of hospital resources as well as endangering patient health. This fact makes unattended medi- cal appointments both socially expensive and economically costly. This research aimed to build a predictive model to identify whether an appointment would be a no-show or not in order to reduce its consequences. This paper proposes a multi-stage framework to build an accurate predictor that also tackles the imbalanced property that the data exhibits. The first stage includes dimensionality reduction to compress the data into its most important components. The second stage deals with the imbalanced nature of the data. Different machine learning algorithms were used to build the classifiers in the third stage. Various evaluation metrics are also discussed and an evaluation scheme that fits the problem at hand is described. The work presented in this paper will help decision makers at health care centers to implement effective strategies to reduce the number of no-shows

    Corneal confocal microscopy detects a reduction in corneal endothelial cells and nerve fibres in patients with acute ischemic stroke

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    YesEndothelial dysfunction and damage underlie cerebrovascular disease and ischemic stroke. We undertook corneal confocal microscopy (CCM) to quantify corneal endothelial cell and nerve morphology in 146 patients with an acute ischemic stroke and 18 age-matched healthy control participants. Corneal endothelial cell density was lower (P<0.001) and endothelial cell area (P<0.001) and perimeter (P<0.001) were higher, whilst corneal nerve fbre density (P<0.001), corneal nerve branch density (P<0.001) and corneal nerve fbre length (P=0.001) were lower in patients with acute ischemic stroke compared to controls. Corneal endothelial cell density, cell area and cell perimeter correlated with corneal nerve fber density (P=0.033, P=0.014, P=0.011) and length (P=0.017, P=0.013, P=0.008), respectively. Multiple linear regression analysis showed a signifcant independent association between corneal endothelial cell density, area and perimeter with acute ischemic stroke and triglycerides. CCM is a rapid non-invasive ophthalmic imaging technique, which could be used to identify patients at risk of acute ischemic stroke.Qatar National Research Fund Grant BMRP2003865

    Neogene Uplift and Magmatism of Anatolia: Insights from Drainage Analysis and Basaltic Geochemistry

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    It is generally agreed that mantle dynamics have played a significant role in generating and maintaining the elevated topography of Anatolia during Neogene times. However, there is much debate about the relative importance of subduction zone and asthenospheric processes. Key issues concern onset and cause of regional uplift, thickness of the lithospheric plate, and the presence or absence of temperature and/or compositional anomalies within the convecting mantle. Here, we tackle these interlinked issues by analyzing and modeling two disparate suites of observations. First, a drainage inventory of 1,844 longitudinal river profiles is assembled. This geomorphic database is inverted to calculate the variation of Neogene regional uplift through time and space by minimizing the misfit between observed and calculated river profiles subject to independent calibration. Our results suggest that regional uplift commenced in the east at 20 Ma and propagated westward. Secondly, we have assembled a database of geochemical analyses of basaltic rocks. Two different approaches have been used to quantitatively model this database with a view to determining the depth and degree of asthenospheric melting across Anatolia. Our results suggest that melting occurs at depths as shallow as 60 km in the presence of mantle potential temperatures as high as 1400°C. There is evidence that potential temperatures are higher in the east, consistent with the pattern of sub-plate shear wave velocity anomalies. Our combined results are consistent with isostatic and admittance analyses and suggest that elevated asthenospheric temperatures beneath thinned Anatolian lithosphere have played a first order role in generating and maintaining regional dynamic topography and basaltic magmatism
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