Decentralizing Trust with Resilient Group Signatures in Blockchains

Blockchains have the goal of promoting the decentralization of transactions in a P2Pbased internetworking model that does not depend on centralized trust parties. Along with research on better scalability, performance, consistency control, and security guarantees in their service planes, other challenges aimed at better trust decentralization and fairness models on the research community’s agenda today. Asymmetric cryptography and digital signatures are key components of blockchain systems. As a common flaw in different blockchains, public keys and verification of single-signed transactions are handled under the principle of trust centralization. In this dissertation, we propose a better fairness and trust decentralization model by proposing a service plane for blockchains that provides support for collective digital signatures and allowing transactions to be collaboratively authenticated and verified with groupbased witnessed guarantees. The proposed solution is achieved by using resilient group signatures from randomly and dynamically assigned groups. In our approach we use Threshold-Byzantine Fault Tolerant Digital Signatures to improve the resilience and robustness of blockchain systems while preserving their decentralization nature. We have designed and implemented a modular and portable cryptographic provider that supports operations expressed by smart contracts. Our system is designed to be a service plane agnostic and adaptable to the base service planes of different blockchains. Therefore, we envision our solution as a portable, adaptable and reusable plugin service plane for blockchains, as a way to provide authenticated group-signed transactions with decentralized auditing, fairness, and long-term security guarantees and to leverage a better decentralized trust model. We conducted our experimental evaluations in a cloudbased testbench with at least sixteen blockchain nodes distributed across four different data centers, using two different blockchains and observing the proposed benefits.As blockchains tem principal objetivo de promover a descentralização das transações numa rede P2P, baseada num modelo não dependente de uma autoridade centralizada. Em conjunto com maior escalabilidade, performance, controlos de consistência e garantias de segurança nos planos de serviço, outros desafios como a melhoria do modelo de descentralização e na equidade estão na agenda da comunidade científica. Criptografia assimétrica e as assinaturas digitais são a componente chave dos sistemas de blockchains. Porém, as blockchains, chaves públicas e verificações de transações assinadas estão sobre o princípio de confiança centralizada. Nesta dissertação, vamos propor uma solução que inclui melhores condições de equidade e descentralização de confiança, modelado por um plano de serviços para a blockchain que fornece suporte para assinaturas coletivas e permite que as transações sejam autenticadas colaborativamente e verificadas com garantias das testemunhadas. Isto será conseguido usando assinaturas resilientes para grupos formados de forma aleatória e dinamicamente. A nossa solução para melhorar a resiliência das blockchains e preservar a sua natureza descentralizada, irá ser baseada em assinaturas threshold à prova de falhas Bizantinas. Com esta finalidade, iremos desenhar e implementar um provedor criptográfico modelar e portável para suportar operações criptográficas que podem ser expressas por smart-contracts. O nosso sistema será desenhado de uma forma agnóstica e adaptável a diferentes planos de serviços. Assim, imaginamos a nossa solução como um plugin portável e adaptável para as blockchains, que oferece suporte para auditoria descentralizada, justiça, e garantias de longo termo para criar modelo melhor da descentralização da base de confiança. Iremos efetuar as avaliações experimentais na cloud, correndo o nosso plano de serviço com duas implementações de blockchain e pelo menos dezasseis nós distribuídos em quatro data centres, observando os benefícios da solução proposta

Clinical usefulness of the electroencephalogram in acute stroke: a preliminary study

Introduction: Stroke is the main cause of disability worldwide, being the first cause of death in Portugal. In the first hours of the event, the cranioencephalic CT scan (CT Scan) does not show the lesion in about 74% of cases, making validation of alternative diagnostic approaches of utmost importance. The electroencephalogram (EEG) may provide useful information for the diagnosis and prognosis of stroke. Objective: To study the potential usefulness of the EEG for the early diagnosis of acute stroke in patients with initial negative CT Scan, and for the evaluation of the functional status and risk of epilepsy. Methods: Retrospective analysis of patients with ischemic stroke who underwent EEG and acute phase CT scan between January 2014 and February 2018. Patient characteristics and stroke were classified according to the Oxfordshire Community Stroke Project (OCSP) criteria. The patients were functionally evaluated at 12 months post-stroke by the modified Rankin Scale (mRS) and the existence of post-stroke epilepsy was determined by telephone interview on February 2018. Results: Thirty patients (25 females and 5 males, mean age 70.5 years) were included. According to the OCSP were identified: 40% TACS, 37% PACS, 10% LACS and 13% POCS. 50% with acute vascular injury visible on the initial CT Scan performed with 7 hours of evolution in median. All patients underwent EEG with a median of 3 days of evolution, and slow focal activity was observed in all patients, and focal paroxysmal activity (PA) was seen in 17% of the participants. 17 patients (58% of patients) developed post-stroke epilepsy (PSE) with 4 of these having PA evidence in the initial EEG (24%). One of the patients with PA in the initial EEG did not develop epilepsy during a 4 years follow-up period. In patients without PA, the average of mRs at follow-up was 3.8 and the mortality was 24%, whereas in patients with PA, the mean of the mRs was 5.0 and the mortality was 40%. Conclusion: In this study, unlike CT Scan, the acute-phase EEG presented with abnormal features in all patients with acute stroke, therefore the EEG may potentially provide significant diagnostic information, estimates of risk for developing future epilepsy and also overall risk stratification. Further studies are needed to validate this hypothesis.info:eu-repo/semantics/publishedVersio

Impact of 24H Ambulatory EEG in the clinical approach to patients with suspected Epilepsy

Introdução: O eletroencefalograma constitui a técnica gold-standard para avaliar a atividade cortical epileptógenea. No entanto, a sua sensibilidade revela-se baixa nas modalidades de registo de curta duração, sendo que, neste contexto, a utilização do EEG Ambulatório de 24 horas (EEGa) veio permitir uma maior capacidade diagnóstica, enquanto registo prolongado, a custos controlados. Objetivo: Analisar o impacto do EEGa na avaliação de doentes com suspeita de epilepsia, através da sua sensibilidade e especificidade para esse diagnóstico clínico. Secundariamente, a) avaliar a sensibilidade em função da distância temporal à última crise, b) averiguar se existe relação entre a presença de atividade paroxística e lesão, c) avaliar o follow-up dos doentes e d) determinar possíveis fatores preditivos. Material e Métodos: Estudo observacional retrospetivo de uma amostra contínua dos pacientes com suspeita de epilepsia que realizaram EEGa entre maio de 2011 e maio de 2018 no Laboratório de Neurofisiologia da Unidade Local de Saúde de Matosinhos. Resultados: Amostra de 83 indivíduos, com idade média de 44.5 anos (79 adultos e 4 pediátricos). A sensibilidade foi de 97% e especificidade de 73% para o diagnóstico de epilepsia, com uma taxa de falsos positivos e falsos negativos de 5% e 7%, respetivamente. Conclusões: O EEGa deve ser um estudo neurofisiológico a considerar mais frequentemente na prática clínica, almejando um diagnóstico mais precoce de epilepsia ou contrariando este, designadamente nos casos em que os exames de primeira linha sejam normais e a convicção clínica permaneça. A brevidade obtida para o diagnóstico evita as expectáveis e demais consequências.info:eu-repo/semantics/publishedVersio

A bússola estratégica e o desenvolvimento tecnológico e industrial europeu

Em Março de 2022 foi aprovado o novo documento de orientação político-estratégica da União Europeia. O IDN Brief de Maio de 2022 reúne seis perspectivas sobre várias dimensões deste documento.info:eu-repo/semantics/publishedVersio

Dermatologists' attitude towards psoriasis treatment during the COVID-19 pandemic

Publisher Copyright: Copyright © 2021 Torres T, Pereira M, Paiva Lopes MJ, Rebelo C, Pedro Andrade P, Henrique M, Oliveira H, Ferreira P, Marques Pinto G, Menezes Brandão F, Rozeira J, Filipe P, Tavares Bello R. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Background: The COVID-19 pandemic introduced new challenges in several dimensions in healthcare services. Herein, we describe the real-life strategies and therapeutic options adopted by dermatologists regarding their patients with psoriasis being treated with or with an indication for systemic therapy during the first COVID-19 lockdown period in Portugal. Methods: The study involves a web-based survey on the clinical management of systemic therapy for psoriasis during the COVID-19 pandemic administered to Portuguese dermatologists. The survey consisted of 55 questions (4 openended questions; 51 closed-ended questions), grouped into 6 sections. Results: A total of 60 dermatologists voluntarily participated in this survey. Nearly 63% of the participants opted for suspending biologics during the COVID-19 lockdown period and 23.3% increased the time between drug administrations. Eighty percent of the participants agreed that biologics did not change the probability of acquiring COVID-19 and 58.4% believed that these drugs decreased or did not change the severity of the disease. Approximately one-third of the participants opted not to prescribe a biological agent in patients despite clinical indication over the duration of the pandemic. Nearly 25% of the participants opted for suspending traditional immunosuppressant administration. Virtual appointments were an option for 93.3% of the participants. Conclusion: The COVID-19 pandemic has significantly affected the management of patients with psoriasis being treated with or with an indication for systemic therapy. Some of the decisions made during the first lockdown period were contrary to what we know today. These decisions might have had a significant impact on patients' quality of life and on future therapeutic success. An adequate interpretation and analysis of the available data will be extremely important to an insightful adaptation of the clinical practice in future confinement or restrictive scenarios.publishersversionpublishe

Novel Machado-Joseph disease-modifying genes and pathways identified by whole-exome sequencing

Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases

Novel Machado-Joseph disease-modifying genes and pathways identified by whole-exome sequencing

Funding Information: This work was funded by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020 , and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia / Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/DTP-PIC/2638/2017 ( POCI-01-0145-FEDER-016592 ); GenomePT ( POCI-01-0145-FEDER-022184 ); ICVS Scientific Microscopy Platform , member of the national infrastructure PPBI - Portuguese Platform of Bioimaging ( PPBI-POCI-01-0145-FEDER-022122 ; by National funds , through the Foundation for Science and Technology (FCT) - project UIDB/50026/2020 and UIDP/50026/2020 ; and by the project NORTE-01-0145-FEDER-000013 , supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) . MR is supported by FCT ( CEECIND/03018/2018 ). ARVM ( SFRH/BD/129547/2017 ) and AFF ( SFRH/BD/121101/2016 ) are supported by a PhD grant financed by FCT . CB is supported by the Multiple System Atrophy Trust and Alzheimer's Research UK . MDC received funding from National Ataxia Foundation (NAF) and from FCT ( SFRH/BPD/101925/2014 ); DV-C received a grant from FCT ( SFRH/BD/147826/2019 ). Publisher Copyright: © 2021Machado-Joseph disease (MJD/SCA3) is a neurodegenerative polyglutamine disorder exhibiting a wide spectrum of phenotypes. The abnormal size of the (CAG)n at ATXN3 explains ~55% of the age at onset variance, suggesting the involvement of other factors, namely genetic modifiers, whose identification remains limited. Our aim was to find novel genetic modifiers, analyse their epistatic effects and identify disease-modifying pathways contributing to MJD variable expressivity. We performed whole-exome sequencing in a discovery sample of four age at onset concordant and four discordant first-degree relative pairs of Azorean patients, to identify candidate variants which genotypes differed for each discordant pair but were shared in each concordant pair. Variants identified by this approach were then tested in an independent multi-origin cohort of 282 MJD patients. Whole-exome sequencing identified 233 candidate variants, from which 82 variants in 53 genes were prioritized for downstream analysis. Eighteen disease-modifying pathways were identified; two of the most enriched pathways were relevant for the nervous system, namely the neuregulin signaling and the agrin interactions at neuromuscular junction. Variants at PARD3, NFKB1, CHD5, ACTG1, CFAP57, DLGAP2, ITGB1, DIDO1 and CERS4 modulate age at onset in MJD, with those identified in CFAP57, ACTG1 and DIDO1 showing consistent effects across cohorts of different geographical origins. Network analyses of the nine novel MJD modifiers highlighted several important molecular interactions, including genes/proteins previously related with MJD pathogenesis, namely between ACTG1/APOE and VCP/ITGB1. We describe novel pathways, modifiers, and their interaction partners, providing a broad molecular portrait of age at onset modulation to be further exploited as new disease-modifying targets for MJD and related diseases.publishersversionpublishe

Investigating the role of symptom valorisation in tuberculosis patient delay in urban areas in Portugal

URBANTB group: Patrícia Soares (Representative of the consortium), Mário Carreira, Sofia Pereira, Catarina Alves, Filipe Alves, Ana Rodrigues, Ana Moreira, Márcia Cardoso, Sandra Mota, Ana Gomes, Liliana Ferreira, Marta Lopes, Isabel Correia, Juan Rachadell, Maria Gameiro, Ângela Dias, Manuel Pereira, Jorge Gonçalves, Maria Gonçalves, Adriana Taveira, Celene Neves, Lucinda Silva, Maria Mendes, Maria Teixeira, Maria Pereira, Milena Piedade, Antónia Teixeira & Carlos Carvalho.Background: Diagnosis delay contributes to increased tuberculosis (TB) transmission and morbimortality. TB incidence has been decreasing in Portugal, but median patient delay (PD) has risen. Symptom valorisation may determine PD by influencing help-seeking behaviour. We aimed to analyse the association between symptom valorisation and PD, while characterising individuals who disregarded their symptoms. Methods: A cross-sectional study was conducted among TB patients in Lisbon and Oporto in 2019 - 2021. Subjects who delayed seeking care because they did not value their symptoms or thought these would go away on their own were considered to have disregarded their symptoms. PD was categorised using a 21-day cut-off, and a 30-day cut-off for sensitivity analysis. We estimated the effect of symptom valorisation on PD through a directed acyclic graph. Then, a multivariable regression analysis characterised patients that disregarded their symptoms, adjusting for relevant variables. We fitted Poisson regression models to estimate crude and adjusted prevalence ratios (PR). Results: The study included 75 patients. Median PD was 25 days (IQR 11.5-63.5), and 56.0% of participants had PD exceeding 21 days. Symptom disregard was reported by 38.7% of patients. Patients who did not value their symptoms had higher prevalence of PD exceeding 21 days compared to those who valued their symptoms [PR 1.59 (95% CI 1.05-2.42)]. The sensitivity analysis showed consistent point estimates but wider confidence intervals [PR 1.39 (95% CI 0.77-2.55)]. Being a smoker was a risk factor for symptom disregard [PR 2.35 (95% CI 1.14-4.82)], while living in Oporto [PR 0.35 (95% CI 0.16-0.75)] and having higher household incomes [PR 0.39 (95% CI 0.17-0.94)] were protective factors. Conclusions: These findings emphasise the importance of symptom valorisation in timely TB diagnosis. Patients who did not value their symptoms had longer PD, indicating a need for interventions to improve symptom recognition. Our findings also corroborate the importance of the socioeconomic determinants of health, highlighting tobacco as a risk factor both for TB and for PD.This work was supported by the Fundação para a Ciência e Tecnologia (FCT, Portugal) [Grant: PTDC/SAU-PUB/31346/2017]. The present publication was funded by Fundação para a Ciência e Tecnologia (FCT, Portugal) national support through Comprehensive Health Research Centre (CHRC) [UIDP/04923/2020].info:eu-repo/semantics/publishedVersio

Promoção do Sucesso e Redução do Abandono Académico: Plano de Ação

Projeto financiado: POCH-02-53I2-FSE-000030 - Skills 4 Pós-COVID - Competências para o futuro no Ensino Superior.De forma de criar e potenciar, no Instituto Politécnico de Leiria, um trabalho colaborativo a partir da identificação e utilização de uma metodologia integrada de promoção do sucesso escolar, que permita identificar, no contexto académico, todas as dimensões do problema e um roteiro de intervenção futuro que inclua a identificação de estratégias para promoção do sucesso académico em Instituições de Ensino Superior nacionais e internacionais, foi desenvolvido o “Laboratório da Mudança”. Através de um método sistémico, participativo e criativo para enfrentar, gerir e mitigar problemas sociais complexos, como são o insucesso e abandono escolar, foi desenvolvido um trabalho em conjunto com os diferentes intervenientes da comunidade académica do Instituto Politécnico de Leiria, no qual foi utilizada a ferramenta Teoria da Mudança para a criação de um plano de ação face a problemas sociais complexos. No Laboratório da Mudança foram convidados a participar vários atores da comunidade académica do IP Leiria, desde direções e escolas, coordenações pedagógicas e demais serviços, bem como docentes e estudantes. A equipa multidisciplinar constituída para o desenvolvimento do Laboratório trouxe contributos variados relevantes e inovadores no desenho de uma estratégia colaborativa e na construção do presente plano de ação. Aquando da identificação do problema, e após o término do projeto, estes atores contribuirão na promoção de outras estratégias, além das propostas em desenvolvimento neste projeto, que possam ser concebidas no futuro visando a resolução dos problemas identificados do insucesso e abandono escolar.N/