40 research outputs found
Code Merging for Programmable Data Plane Virtualization
Tese de mestrado, Engenharia Informática (Arquitetura, Sistemas e Redes de Computadores) Universidade de Lisboa, Faculdade de Ciências, 2021Recent advances in the hardware capabilities of switching chips have enabled programmability of the data plane. The development of new network protocols and functions, which historically demanded long ASIC design lifecycles to be operated, can now happen quickly and flexibly on Programmable Data Planes (PDPs). Network administrators can directly deploy custom packet processing logic as programs (written in high-level languages such as P4) into their programmable switching ASICs. There are, however, some unresolved problems associated with current PDPs, which hinder their adoption in production networks. One such problem is that a PDP target (e.g., a switch) is currently only capable of running one program at any given time. This limitation has several important consequences. First, it constrains network administrators to write large and complex programs whenever they need to deploy multiple functionalities, which is the common case. Second, it precludes resource sharing between multiple programs, potentially written by different users, limiting resource utilization and thus impacting efficiency. Inspired by the success story of virtualization in the domain of operating systems, researchers have started proposing solutions to overcome the above issue by virtualizing PDPs. Unfortunately, existing solutions are either very inefficient or lack generality. Hence, this work aims at designing a programmable data plane virtualization platform that enables the deployment of many independently-developed P4 programs on a PDP while introducing the minimum resource overhead. We achieve virtualization at the compiler-level by merging network functionalities into a single, monolithic program, where the individual P4 programs coexist fully isolated from each other. We leverage a state-of-the-art system for code merging, P4Visor, but we improve it by extending the number and variety of P4 programs that can be virtualized, from only two to multiple, and by improving resource efficiency, specifically in the packet parsing module
The national inventory of geological heritage: methodological approach and results
A existência de um inventário nacional de património geológico é fundamental para se poderem implementar estratégias de geoconservação. Este trabalho apresenta a metodologia usada no desenvolvimento do mais completo inventário de geossítios, realizado até ao momento em Portugal, assim como os principais resultados obtidos. O inventário vai integrar o Sistema de Informação do Património Natural e o Cadastro Nacional dos Valores Naturais Classificados, ambos geridos pelo Instituto de Conservação da Natureza e da Biodiversidade.The existence of a national inventory of the geological heritage is of paramount importance for the implementation of a geoconservation strategy. This paper presents the methodological approach used to produce the most complete geosites inventory in Portugal, so far, and the obtained results. This inventory will be uploaded into the National Database of Natural Heritage managed by the Portuguese authority for nature conservation.Este trabalho é apoiado pela Fundação para a Ciência e a Tecnologia, através do financiamento plurianual do CGUP e do projecto de investigação “Identificação, caracterização e conservação do património geológico: uma estratégia de geoconservação para Portugal” (PTDC/CTE-GEX/64966/2006).info:eu-repo/semantics/publishedVersio
SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal
Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by
the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration
with more than 50 laboratories distributed nationwide.
Methods By applying recent phylodynamic models that allow integration of individual-based
travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal.
Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from
European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland),
which were consistent with the countries with the highest connectivity with Portugal.
Although most introductions were estimated to have occurred during early March 2020, it is
likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the
first cases were confirmed.
Conclusions Here we conclude that the earlier implementation of measures could have
minimized the number of introductions and subsequent virus expansion in Portugal. This
study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and
Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with
the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team,
IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation
(https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing
guidance on the implementation of the phylodynamic models; Joshua L. Cherry
(National Center for Biotechnology Information, National Library of Medicine, National
Institutes of Health) for providing guidance with the subsampling strategies; and all
authors, originating and submitting laboratories who have contributed genome data on
GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions
expressed in this article are those of the authors and do not reflect the view of the
National Institutes of Health, the Department of Health and Human Services, or the
United States government. This study is co-funded by Fundação para a Ciência e Tecnologia
and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on
behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study
come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by
COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation
(POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal
Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL
2020 Partnership Agreement, through the European Regional Development Fund
(ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Practical guide for the use of biological therapies in rheumatoid arthritis - Update of December 2011
The authors review the practical aspects of biologi -cal therapy use for rheumatoid arthritis patients, commenting safety issues before and after treatment initiation and the best treatment strategies to optimize efficacy.publishersversionpublishe
Portuguese recommendations for the prevention, diagnosis and management of primary osteoporosis - 2018 update
Background: Advances in osteoporosis (OP)case definition, treatment options, optimal therapy duration and pharmacoeconomic evidence in the national context motivated the Portuguese Society of Rheumatology (SPR) to update the Portuguese recommendations for the diagnosis and management of osteoporosis published in 2007.
Methods: SPR bone diseases’ working group organized meetings involving 55 participants (rheumatologists, rheumatology fellows and one OP specialist nurse) to debate and develop the document. First, the working group selected 11 pertinent clinical questions for the diagnosis and management of osteoporosis in standard clinical practice. Then, each question was investigated through literature review and draft recommendations were built through consensus. When insufficient evidence was available, recommendations were based on experts’ opinion and on good clinical practice. At two national meetings, the recommendations were discussed and updated. A draft of the recommendations full text was submitted to critical review among the working group and suggestions were incorporated. A final version was circulated among all Portuguese rheumatologists before publication and the level of agreement was anonymously assessed using an online survey.
Results: The 2018 SPR recommendations provide comprehensive guidance on osteoporosis prevention, diagnosis, fracture risk assessment, pharmacological treatment initiation, therapy options and duration of treatment, based on the best available evidence. They attained desirable agreement among Portuguese rheumatologists. As more evidence becomes available, periodic revisions will be performed.
Target audience and patient population: The target audience for these guidelines includes all clinicians. The target patient population includes adult Portuguese people.
Intended use: These recommendations provide general guidance for typical cases. They may not be appropriate in all situations - clinicians are encouraged to consider this information together with updated evidence and their best clinical judgment in individual cases
Portuguese recommendations for the use of methotrexate in the treatment of rheumatoid arthritis
Objectives:To develop Portuguese evidence-based recommendations for the use of methotrexate (MTX) in daily clinical practice in rheumatic disorders. Methods:The Portuguese project was integrated in the multinational 3E Initiative (Evidence, Expertise, Exchange) 2007-2008 where a total of 751 rheumatologists from 17 countries have participated. Ten clinical questions concerning the use of MTX in rheumatic diseases were formulated and the Portuguese group added three more questions. A systematic literature search in Medline, Embase, Cochrane Library and 2005-2007 ACR/EULAR meeting abstracts was conducted. Selected articles were systematically reviewed and the evidence was appraised according to the Oxford Levels of Evidence. In Portugal, a national meeting was held in Obidos on February 15 th and 16 th, 2008, involving 50 rheumatologists who discussed and voted by Dephi method the recommendations. Finally, the agreement among the rheumatologists and the potential impact on their clinical practice was assessed. Results: Thirteen national key recommendations on the use of MTX were formulated: work-up before starting MTX, optimal dosage and route of administration, use of folic acid, monitoring, management of hepatotoxicity, long-term safety, mono versus combination therapy, management in the perioperative period, during infections, before/during pregnancy and after clinical remission, screening and treatment of tuberculosis and the role of MTX as a steroid-sparing agent in rheumatic diseases. Discussion: The Portuguese recommendations for the use of MTX in daily clinical practice were developed, which are evidence-based and supported by a panel of 50 rheumatologists, enhancing their validity and practical use. This project was integrated in a multinational initiative that led to the recent publication of ten multinational recommendations which differ from ours in some specific aspects.publishersversionpublishe
The national inventory of geosites in Portugal
During the last three years geoscientists of various institutions have developed a project aiming the setup of a geoconservation strategy in Portugal (Brilha, 2009). One of the main goals of the project was the establishment of an inventory of the most important Portuguese geosites, under the scientific point of view. In a near future, national authorities will consider this inventory as a technical support for the implementation of nature conservation policies and land-use strategies.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTE-GEX76496672006 "Identification, characterisation and conservation of geological heritage : a geoconservation strategy for Portugal
O inventário nacional do património geológico : abordagem metodológica e resultados = The national inventory of geological heritage : methodological approach and results
A existência de um inventário nacional de património geológico é fundamental para se poderem implementar estratégias de
geoconservação. Este trabalho apresenta a metodologia usada no desenvolvimento do mais completo inventário de geossítios.
realizado até ao momento em Portugal, assim como os principais resultados obtidos. O inventário vai integrar o Sistema de
Informação do Património Natural e o Cadastro Nacional dos Valores Naturais Classificados, ambos geridos pelo Instituto de
Conservação da Natureza e da Biodiversidade