581 research outputs found

    Intra-Domain Pathlet Routing

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    Internal routing inside an ISP network is the foundation for lots of services that generate revenue from the ISP's customers. A fine-grained control of paths taken by network traffic once it enters the ISP's network is therefore a crucial means to achieve a top-quality offer and, equally important, to enforce SLAs. Many widespread network technologies and approaches (most notably, MPLS) offer limited (e.g., with RSVP-TE), tricky (e.g., with OSPF metrics), or no control on internal routing paths. On the other hand, recent advances in the research community are a good starting point to address this shortcoming, but miss elements that would enable their applicability in an ISP's network. We extend pathlet routing by introducing a new control plane for internal routing that has the following qualities: it is designed to operate in the internal network of an ISP; it enables fine-grained management of network paths with suitable configuration primitives; it is scalable because routing changes are only propagated to the network portion that is affected by the changes; it supports independent configuration of specific network portions without the need to know the configuration of the whole network; it is robust thanks to the adoption of multipath routing; it supports the enforcement of QoS levels; it is independent of the specific data plane used in the ISP's network; it can be incrementally deployed and it can nicely coexist with other control planes. Besides formally introducing the algorithms and messages of our control plane, we propose an experimental validation in the simulation framework OMNeT++ that we use to assess the effectiveness and scalability of our approach.Comment: 13 figures, 1 tabl

    La "Tavola Strozzi" della Napoli Aragonese come progetto di Francesco di Giorgio

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    Dopo una breve ricostruzione del periodo storico ed una sintetica rassegna degli studi sulla Tavola Strozzi, custodita al museo di San Martino di Napoli, si fa riferimento alla attività di Francesco di Giorgio a Napoli, prima come inviato dal Duca di Urbino e poi come, oggi diremmo, libero professionista e si pone l’ipotesi che la tavola sia una esposizione grafica del suo progetto per mostrare e quindi poter poi far approvare un radicale cambiamento del porto e delle nuove opere di difesa da realizzare a Napoli. Si hanno così motivi per allargare lo spazio temporale della rappresentazione pensando ai momenti più significativi del regno Aragonese, superando le varie obiezioni degli studiosi che hanno contestato la contemporaneità degli eventi rappresentati. Da un attento esame dell’opera, delle cedole Aragonesi, dei dispacci degli ambasciatori, della Croniche di Notar Jacopo e del Ferraiolo, delle tante analogie con il dipinto della predica di San Bernardino, dal confronto con la città ideale di Berlino, si conferma l’impressione che si ha quando si vede la tavola per la prima volta e cioè che riguardi un progetto per il nuovo ciclopico porto, per opere di difesa della città e che sia frutto dell’intelligenza di Francesco di Giorgio

    Laparoscopy in liver transplantation: The future has arrived

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    In the last two decades, laparoscopy has revolutionized the field of surgery. Many procedures previously performed with an open access are now routinely carried out with the laparoscopic approach. Several advantages are associated with laparoscopic surgery compared to open procedures: reduced pain due to smaller incisions and hemorrhaging, shorter hospital length of stay, and a lower incidence of wound infections. Liver transplantation (LT) brought a radical change in life expectancy of patients with hepatic endstage disease. Today, LT represents the standard of care for more than fifty hepatic pathologies, with excellent results in terms of survival. Surely, with laparoscopy and LT being one of the most continuously evolving challenges in medicine, their recent combination has represented an astonishing scientific progress. The intent of the present paper is to underline the current role of diagnostic and therapeutic laparoscopy in patients waiting for LT, in the living donor LT and in LT recipients

    Ten-Year Experience with Endomyocardial Biopsy after Orthotopic Heart Transplantation: Comparison between Trans-Jugular and Trans-Femoral Approach

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    Background: Endomyocardial biopsy (EMB) is considered the gold standard for monitoring allograft rejection after heart transplantation. EMB is an invasive procedure that may be performed via a trans-jugular or a trans-femoral approach with a complication rate reported as less than 6%. The aim of this study was to evaluate the complication rate after EMBs in heart recipients and to compare the results of EMBs performed via a trans-jugular or a trans-femoral approach. Methods: Medical records of heart recipients undergoing EMBs between January 2012 and December 2022 were retrospectively reviewed. EMB-related complications were classified as major (death, pericardial effusion, hemopericardium, cardiac tamponade requiring a pericardiocentesis or an urgent cardiac surgery, ventricular arrythmias, permanent atrio-ventricular block requiring permanent pacing, hemothorax, pneumothorax and retroperitoneal bleeding) and minor (de novo tricuspid regurgitation, arrhythmias, coronary artery fistula, vascular access site complications). Results: A total of 1698 EMBs were performed during the study period at our institution in 212 heart recipients. There were 927 (55%) EMBs performed through a trans-jugular approach (TJ group) and 771 (45%) EMBs performed through a trans-femoral approach (TF group). A total of 60 (3.5%) complications were recorded, including nine (0.5%) major complications (six cardiac tamponades, two pneumothorax and one retroperitoneal bleeding) and 51 (3%) minor complications (seven coronary fistulae, five de novo tricuspid regurgitation, four supraventricular arrythmias and thirty-five vascular access site complications). No difference was found in total (38 [4%] vs. 22 [3%]; p = 0.16) and major (6 [1%} vs. 3 [0.4%]; p = 0.65) complications (32 [3%] vs. 19 [2%]; p = 0.23) between the TJ group and the TF group. No difference was found in male sex, age at time of EMB and time from HT between complicated and not complicated EMBs. Conclusions: EMBs represent a safe procedure with a low risk of complications. In our experience, EMBs performed via a trans-jugular approach are as safe as the trans-femoral approach

    Measurement of Sea Waves

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    Sea waves constitute a natural phenomenon with a great impact on human activities, and their monitoring is essential for meteorology, coastal safety, navigation, and renewable energy from the sea. Therefore, the main measurement techniques for their monitoring are here reviewed, including buoys, satellite observation, coastal radars, shipboard observation, and microseism analysis. For each technique, the measurement principle is briefly recalled, the degree of development is outlined, and trends are prospected. The complementarity of such techniques is also highlighted, and the need for further integration in local and global networks is stressed

    Resilience and response of the congenital cardiac network in Italy during the COVID-19 pandemic

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    : The worldwide response to the current COVID-19 pandemic has been focused on how to prevent the disease and to protect the high-risk patient from a potentially lethal infection. Several consensus and guidelines articles have been published dealing with the cardiac patient with systemic hypertension, heart transplant or heart failure. Very little is known about the patients, both in the pediatric as well as in the adult age, with congenital heart disease. The peculiar physiology of the heart with a native, repaired or palliated congenital heart defect deserves a specialized care. Hereby we describe the early recommendations issued by the Italian Society of Pediatric Cardiology and Congenital Heart Disease and how the network of the congenital cardiac institutions in Italy reacted to the threat of potential wide spread of the infection among this fragile kind of patient

    Vrtlarski rad i izloženost teškim metalima u gradskom okružju

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    Urban soil may be a source of occupational exposure to various pollutants in gardening and land cultivation. This paper presents data of a one-year follow-up of lead, cadmium, nickel, chromium, and vanadium in the environment of the city of Bologna. Samples of soil and leaves were collected at three locations; gardens from the inner-city high-traffic area, parks in moderatetraffic area, and parks in suburban, low-traffic area. The top and deeper layers of soil and leaves were mainly polluted by lead at all locations, which corresponded to the traffic density. Personal samplers recorded greater concentrations of airborne metals than did the area samplers but the values kept below the threshold limit established by the American Conference of Governmental Industrial Hygienists for the working environment. Due to cumulative nature and interactive effects of toxic metals with other toxic and essential elements, long-term exposure to metals in the urban environment may be a health risk for occupationally exposed gardeners.Gradsko tlo može biti izvorom profesionalne izloženosti različitim onečišćivačima u vrtlara, uključujući otrovne teške metale koji se talože iz onečišćenog zraka na tlo i lišće. U radu su prikazani podaci jednogodišnjeg praćenja koncentracija olova, kadmija, niklja, kroma i vanadija u talijanskom gradu Bologni. Uzorci tla i lišća skupljani su na tri mjesta s različitom gustoćom prometa; u središtu grada s velikom gustoćom prometa, u parkovima s umjerenim prometom u okolišu i u prigradskim parkovima sa slabim prometom. Na svim lokacijama gornji i dublji slojevi tla bili su podjednako onečišćeni ponajprije olovom i to je bilo u svezi s prometnom gustoćom. Koncentracije metala u zraku utvr|ene u filtrima osobnih skupljača bile su više od koncentracija u skupljačima na tlu. Vrijednosti metala u zraku bile su niže od graničnih vrijednosti utvr|enih za radni okoliš od Američke konferencije vladinih industrijskih higijeničara (American Conference of Governmental Industrial Hygienists). Zaključeno je da vrtlari, u usporedbi s općim stanovništvom, i pri niskim razinama izloženosti u gradskom okolišu imaju povećan zdravstveni rizik za štetna djelovanja otrovnih metala i drugih onečišćivača okoliša zbog dugotrajne izloženosti u svezi s njihovim radom

    A framework for multi‐provider virtual private networks in software‐defined federated networks

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    Federated networks represent a remunerable operational way, allowing federated partners to increase their incomes through a sharing resource process. They have been primarily used in the context of cloud computing; nowadays, they are also used to provide connectivity services, like virtual private networks. However, providing such a service by using standard technologies in federated networks requires a nonnegligible effort from different points of view (e.g., configuration effort). In this paper, we propose an software‐defined network (SDN)–based framework aiming at overcoming limitations in currently adopted best practices to issue virtual private networks in federated networks. Relying on the SDN architecture, we propose a method allowing federated providers to quickly and easily create federated networks, reducing unneeded costs (e.g., new hardware), and a way for customers to fast‐access federated services, without any explicit actions from providers. We evaluate our framework by using SDNetkit. We focus on analyzing the impact of our implementation on both control and data plane, in terms of number of control messages exchanged in the network and size of the forwarding tables, respectively.BMBF, 01IS18025A, Verbundprojekt BIFOLD-BBDC: Berlin Institute for the Foundations of Learning and DataBMBF, 01IS18037A, Verbundprojekt BIFOLD-BZML: Berlin Institute for the Foundations of Learning and DataTU Berlin, Open-Access-Mittel – 202
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