Software-Defined Networking: A Comprehensive Survey Kreutz, Diego; Ramos, Fernando M. V.; Verissimo, Paulo Esteves ...
Proceedings of the IEEE,
2015-Jan., 2015-1-00, 20150101, Letnik:
103, Številka:
1
Journal Article
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The Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks ...are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms - with a focus on aspects such as resiliency, scalability, performance, security, and dependability - as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.
Stalled progress in controlling Plasmodium falciparum malaria highlights the need for an effective and deployable vaccine. RTS,S/AS01, the most effective malaria vaccine candidate to date, ...demonstrated 56% efficacy over 12 months in African children. We therefore assessed a new candidate vaccine for safety and efficacy.
In this double-blind, randomised, controlled, phase 2b trial, the low-dose circumsporozoite protein-based vaccine R21, with two different doses of adjuvant Matrix-M (MM), was given to children aged 5–17 months in Nanoro, Burkina Faso—a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals before the malaria season, with a fourth dose 1 year later. All vaccines were administered intramuscularly into the thigh. Group 1 received 5 μg R21 plus 25 μg MM, group 2 received 5 μg R21 plus 50 μg MM, and group 3, the control group, received rabies vaccinations. Children were randomly assigned (1:1:1) to groups 1–3. An independent statistician generated a random allocation list, using block randomisation with variable block sizes, which was used to assign participants. Participants, their families, and the local study team were all masked to group allocation. Only the pharmacists preparing the vaccine were unmasked to group allocation. Vaccine safety, immunogenicity, and efficacy were evaluated over 1 year. The primary objective assessed protective efficacy of R21 plus MM (R21/MM) from 14 days after the third vaccination to 6 months. Primary analyses of vaccine efficacy were based on a modified intention-to-treat population, which included all participants who received three vaccinations, allowing for inclusion of participants who received the wrong vaccine at any timepoint. This trial is registered with ClinicalTrials.gov, NCT03896724.
From May 7 to June 13, 2019, 498 children aged 5–17 months were screened, and 48 were excluded. 450 children were enrolled and received at least one vaccination. 150 children were allocated to group 1, 150 children were allocated to group 2, and 150 children were allocated to group 3. The final vaccination of the primary series was administered on Aug 7, 2019. R21/MM had a favourable safety profile and was well tolerated. The majority of adverse events were mild, with the most common event being fever. None of the seven serious adverse events were attributed to the vaccine. At the 6-month primary efficacy analysis, 43 (29%) of 146 participants in group 1, 38 (26%) of 146 participants in group 2, and 105 (71%) of 147 participants in group 3 developed clinical malaria. Vaccine efficacy was 74% (95% CI 63–82) in group 1 and 77% (67–84) in group 2 at 6 months. At 1 year, vaccine efficacy remained high, at 77% (67–84) in group 1. Participants vaccinated with R21/MM showed high titres of malaria-specific anti-Asn-Ala-Asn-Pro (NANP) antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres after the primary series of vaccinations after a fourth dose administered 1 year later.
R21/MM appears safe and very immunogenic in African children, and shows promising high-level efficacy.
The European & Developing Countries Clinical Trials Partnership, Wellcome Trust, and National Institute for Health Research Oxford Biomedical Research Centre.
Myelodysplastic syndrome (MDS) is a group of clonal disorders that arise in pluripotent bone marrow stem cells and present with characteristic phenotypical features (both morphological and flow ...cytometrical), as well as genotypical abnormalities ....
This collection brings together new insights around current translation and interpreting
practices in national and supranational settings. The book illustrates the importance of
further reflection on ...issues around quality and assessment, given the increased
development of resources for translators and interpreters. The first part of the volume
focuses on these issues as embodied in case studies from a range of national and
regional contexts, including Finland, Switzerland, Italy, Spain and the United States.
The second part takes a broader perspective to look at best practices and questions of
quality through the lens of international bodies and organizations and the shifting
roles of translation and interpreting practitioners in working to manage these issues.
Taken together, this collection demonstrates the relevance of critically examining
processes, competences and products in current institutional translation and
interpreting settings at the national and supranational levels, paving the way for
further research and quality assurance strategies in the field.
Este artículo analiza la producción de Víctor Erice en el siglo XXI entendiéndola como especialmente significativa para ilustrar algunos de los cambios del cine español de esos años. El análisis se ...centra en la forma en que estas obras (corto- y mediometrajes, fragmentos de obras colectivas, ensayos fílmicos, documentales e instalaciones para museos) han planteado una reflexión sobre la experiencia cinematográfica. Para explorar esta relación entre experiencia y lugares, entre la obra del artista y la cultura cinematográfica, el texto se apoyará en uno de los conceptos más comunes en la exégesis de la carrera de Erice: la cinefilia. Al mismo tiempo explora su reformulación teniendo en cuenta los trabajos más relevantes en el campo de los estudios fílmicos a lo largo los últimos veinte años. En base a dos categorías centrales dentro de esta redefinición metodológica de la cinefilia (momento cinéfilo y relocalización), en la parte final de este texto se procederá a un análisis de una serie de obras representativas de la producción audiovisual del director.
In-band Network Telemetry (INT) is gaining traction as an advanced network monitoring approach. Despite a few recent initiatives to orchestrate the collection of in-band network statistics, ...state-of-the-art approaches fall short when it comes to efficiently collect telemetry items while subjected to real-world constraints. In this letter, we propose Probe Planning for In-Band Network Telemetry (P 2 INT) to coordinate how probing packets are generated and routed to ensure that all links are covered so that the required in-band network telemetry data is collected. We theoretically formalize the problem as a Integer Linear Programming model and propose an efficient mathematical programming-based heuristic to solve it. Our results show that P 2 INT outperforms the closest contender by a factor of up to 6x concerning the number of probing cycles generated.
Multi-componential models of translation competence are widely used in translator training as a yardstick for curricular and syllabus design. These models must be adapted to reflect professional ...trends, such as the impact of artificial intelligence, and machine translation in particular, on working methods. This paper describes the process of adapting a pioneering model of legal translation competence to the broader scope of institutional translation in light of recent trends, as verified by triangulating information from multiple interviews, analyses of translation volumes and job descriptors and other professional inputs. The resulting revised descriptor was validated through a survey of 474 translation professionals from 24 international organisations of diverse sizes and domain specialisations. The suitability of the descriptor was corroborated across the board, but variations were found in perceptions of the relevance of sub-competences to ensure translation quality. Profiles with a stronger specialisation in legal translation or more experience in institutional translation showed higher awareness of the relevance of all the sub-competences, especially the core language, strategic and thematic competences, and even more so for translating texts of a legal or administrative nature. The implications of these findings for training purposes in particular are discussed.
L. (lupine) is a legume whose grain/seed has gained increasing interest. Its recognized nutritional properties, namely a high content of protein, dietary fiber and its low fat content, make lupine a ...suitable alternative not only for animal protein, but also as a substitute for more processed and less balanced flours from a nutritional point of view, used in the preparation of bread, cakes and cookies, among others. In addition, its nutritional and bioactive compounds have potential benefits for human health in the prevention and treatment of some diseases. However, the existence of some anti-nutritional compounds and contaminants reveal some concern, requiring effective methods for their detection and eventual removal. This review intends to address the potential of lupine (
) in food and human health and to balance the pros and cons. Nutritional and anti-nutritional components of
seeds and possible contaminants of lupine seeds are examined. The potential health benefits of lupine (seeds), including energy metabolism, cardiovascular diseases, hypertension, glucose and insulin metabolism, bower function and anticonvulsant action, are discussed based on scientific evidence (both clinical trials and studies performed with animal models).
Known as a degenerative and progressive dementia, Alzheimer's disease (AD) affects about 25 million elderly people around the world. This illness results in a decrease in the productivity of people ...and places limits on their daily lives. Electroencephalography (EEG), in which the electrical brain activity is recorded in the form of time series and analyzed using signal processing techniques, is a well-known neurophysiological AD biomarker. EEG is noninvasive, low-cost, has a high temporal resolution, and provides valuable information about brain dynamics in AD. Here, we present an original approach based on the use of quantile graphs (QGs) for classifying EEG data. QGs map frequency, amplitude, and correlation characteristics of a time series (such as the EEG data of an AD patient) into the topological features of a network. The five topological network metrics used here-clustering coefficient, mean jump length, betweenness centrality, modularity, and Laplacian Estrada index-showed that the QG model can distinguish healthy subjects from AD patients, with open or closed eyes. The QG method also indicates which channels (corresponding to 19 different locations on the patients' scalp) provide the best discriminating power. Furthermore, the joint analysis of delta, theta, alpha, and beta wave results indicate that all AD patients under study display clear symptoms of the disease and may have it in its late stage, a diagnosis known a priori and supported by our study. Results presented here attest to the usefulness of the QG method in analyzing complex, nonlinear signals such as those generated from AD patients by EEGs.
Duality between time series and networks Campanharo, Andriana S L O; Sirer, M Irmak; Malmgren, R Dean ...
PloS one,
08/2011, Letnik:
6, Številka:
8
Journal Article
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Studying the interaction between a system's components and the temporal evolution of the system are two common ways to uncover and characterize its internal workings. Recently, several maps from a ...time series to a network have been proposed with the intent of using network metrics to characterize time series. Although these maps demonstrate that different time series result in networks with distinct topological properties, it remains unclear how these topological properties relate to the original time series. Here, we propose a map from a time series to a network with an approximate inverse operation, making it possible to use network statistics to characterize time series and time series statistics to characterize networks. As a proof of concept, we generate an ensemble of time series ranging from periodic to random and confirm that application of the proposed map retains much of the information encoded in the original time series (or networks) after application of the map (or its inverse). Our results suggest that network analysis can be used to distinguish different dynamic regimes in time series and, perhaps more importantly, time series analysis can provide a powerful set of tools that augment the traditional network analysis toolkit to quantify networks in new and useful ways.
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