309 research outputs found

    Data Warehouse Design and Management: Theory and Practice

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    The need to store data and information permanently, for their reuse in later stages, is a very relevant problem in the modern world and now affects a large number of people and economic agents. The storage and subsequent use of data can indeed be a valuable source for decision making or to increase commercial activity. The next step to data storage is the efļ¬cient and effective use of information, particularly through the Business Intelligence, at whose base is just the implementation of a Data Warehouse. In the present paper we will analyze Data Warehouses with their theoretical models, and illustrate a practical implementation in a speciļ¬c case study on a pharmaceutical distribution companyData warehouse, database, data model.

    An Analisys of Business VPN Case Studies

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    A VPN (Virtual Private Network) simulates a secure private network through a shared public insecure infrastructure like the Internet. The VPN protocol provides a secure and reliable access from home/office on any networking technology transporting IP packets. In this article we study the standards for VPN implementation and analyze two case studies regarding a VPN between two routers and two firewalls.VPN; Network; Protocol.

    Link Stability inWireless Multi-Rate Ad Hoc Networks

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    Wireless ad hoc single-rate environments typically use a Distance Vector routing with a metric based on hop-count minimization. In practice, the technique of minimizing the distance does not reward in the case of multirate, therefore it may be prefereable to use protocols privileging link stability instead of speed and minimum distance. We study link stability in a wireless high mobility environment and propose a Route Discovery mechanism privileging the stablest link.VPN; Network; Protocol.

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    Impact of the COVID-19 Pandemic on Otolaryngology Residency: A Real-Life Experience

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    The coronavirus disease (COVID-19) pandemic as been rapidly spreading worldwide. In our country, the entire Italian Healthcare System has been forced to adapt to this unprecedented condition in this century. The Head and Neck Department clinical and surgical activity was substantially reduced. In this situation, the Ear, Nose and Throat (ENT) residents in University Hospitals find themselves in an uncertain position; we are physicians, facing a deadly disease about which much remains unknown, but we are also trainees, and there is a high risk for our residency training to be affected. With this Letter, we would like to give a testimony of our experience and give some advices to bridge the training gap

    Genetic background of mitral valve prolapse

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    Mitral valve prolapse (MVP) has a prevalence of 2-3% among the population. It involves a heterogeneous group of patients with different expressions and according to the phenotype can be further divided into fibroelastic deficiency, which is mainly considered as a degeneration due to aging, and myxomatous disease, frequently associated with familiar clusters. Thus, MVP can be present in syndromic, when part of a well-defined syndrome, and non-syndromic forms. The latter occurs more often. To the second belong both familiar and isolated or sporadic forms. On one hand, among familial forms, although X-linked transmission related t

    The Brain on Low Power Architectures - Efficient Simulation of Cortical Slow Waves and Asynchronous States

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    Efficient brain simulation is a scientific grand challenge, a parallel/distributed coding challenge and a source of requirements and suggestions for future computing architectures. Indeed, the human brain includes about 10^15 synapses and 10^11 neurons activated at a mean rate of several Hz. Full brain simulation poses Exascale challenges even if simulated at the highest abstraction level. The WaveScalES experiment in the Human Brain Project (HBP) has the goal of matching experimental measures and simulations of slow waves during deep-sleep and anesthesia and the transition to other brain states. The focus is the development of dedicated large-scale parallel/distributed simulation technologies. The ExaNeSt project designs an ARM-based, low-power HPC architecture scalable to million of cores, developing a dedicated scalable interconnect system, and SWA/AW simulations are included among the driving benchmarks. At the joint between both projects is the INFN proprietary Distributed and Plastic Spiking Neural Networks (DPSNN) simulation engine. DPSNN can be configured to stress either the networking or the computation features available on the execution platforms. The simulation stresses the networking component when the neural net - composed by a relatively low number of neurons, each one projecting thousands of synapses - is distributed over a large number of hardware cores. When growing the number of neurons per core, the computation starts to be the dominating component for short range connections. This paper reports about preliminary performance results obtained on an ARM-based HPC prototype developed in the framework of the ExaNeSt project. Furthermore, a comparison is given of instantaneous power, total energy consumption, execution time and energetic cost per synaptic event of SWA/AW DPSNN simulations when executed on either ARM- or Intel-based server platforms

    Topical use of tranexamic acid in coronary artery bypass operations: A double-blind, prospective, randomized, placebo-controlled study

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    AbstractObjectives: We sought to investigate the effect of topical application of tranexamic acid into the pericardial cavity in reducing postoperative blood loss in coronary artery surgery. Methods: A prospective, randomized, double-blind investigation with parallel groups was performed. Forty consecutive patients undergoing primary coronary surgery were randomly assigned to group 1 (tranexamic acid group) or group 2 (placebo group). Tranexamic acid (1 g in 100 mL of saline solution) or placebo was poured into the pericardial cavity and over the mediastinal tissues before sternal closure. The drainage of mediastinal blood was measured hourly. Results: Chest tube drainage in the first 24 hours was 485 Ā± 166 mL in the tranexamic acid group and 641 Ā± 184 mL in the placebo group (P = .01). Total postoperative blood loss was 573 Ā± 164 mL and 739 Ā± 228 mL, respectively (P = .01). The use of banked donor blood products was not significantly different between the two groups. Tranexamic acid could not be detected in any of the blood samples blindly collected from 24 patients to verify whether any systemic absorption of the drug occurred. There were no deaths in either group. None of the patients required reoperation for bleeding. Conclusions: Topical application of tranexamic acid into the pericardial cavity after cardiopulmonary bypass in patients undergoing primary coronary bypass operations significantly reduces postoperative bleeding. Further studies must be carried out to clarify whether a more pronounced effect on both bleeding and blood products requirement might be seen in procedures with a higher risk of bleeding. (J Thorac Cardiovasc Surg 2000;119:575-80

    Similar long-term results of mitral valve repair for anterior compared with posterior leaflet prolapse

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    ObjectiveThe results of mitral valve repair for anterior leaflet prolapse have been less gratifying than those reported for posterior leaflet prolapse. We compared the long-term durability of 2 different surgical techniques: the edge-to-edge repair, which is used for the treatment of anterior leaflet prolapse, and quadrangular resection, which has been adopted for correction of posterior leaflet prolapse.MethodsFrom 1991 through April 2004, 133 patients with anterior leaflet prolapse and 605 with posterior leaflet prolapse caused by degenerative mitral disease underwent valve repair. The edge-to-edge repair was used for correction of anterior leaflet prolapse, and quadrangular resection of the posterior leaflet, with or without sliding plasty, was used for correction of posterior leaflet prolapse. All patients received a concomitant annuloplasty procedure.ResultsNo hospital deaths occurred in the anterior leaflet prolapse group, whereas 2 (0.3%) patients died in the posterior leaflet prolapse group (P = .7). Follow-up was 100% and 97.2% complete in the anterior and posterior leaflet prolapse groups, respectively. At 10 years, overall survival was 91% Ā± 4.06% for anterior leaflet prolapse and 93.5% Ā± 1.81% for posterior leaflet prolapse (P = .18), and freedom from cardiac death was 95.8% Ā± 2.83% for anterior leaflet prolapse and 97.4% Ā± 0.95% posterior leaflet prolapse (P = .27). Freedom from reoperation was 96% Ā± 2.3% in the anterior leaflet prolapse group and 96.5% Ā± 1.18% in the posterior leaflet prolapse group (P = .37). At follow-up (mean, 4.5 Ā± 3.12 years; range, 1 month-13.2 years), New York Heart Association functional class I or II was documented in 93.2% of patients in the anterior leaflet prolapse group and 92.8% in the posterior leaflet prolapse group (P = .98).ConclusionsThe long-term results of the edge-to-edge repair in the setting of anterior leaflet prolapse are similar to those obtained with quadrangular resection for the treatment of posterior leaflet prolapse
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