Blocking DDoS attacks at the network level

Denial of service (DDoS) is a persistent and continuously growing problem. These attacks are based on methods that flood the victim with messages that it did not request, effectively exhausting its computational or bandwidth resources. The variety of attack approaches is overwhelming and the current defense mechanisms are not completely effective. In today’s internet, a multitude of DDoS attacks occur everyday, some even degrading the availability of critical or governmental services. In this dissertation, we propose a new network level DDoS mitigation protocol that iterates on previous attempts and uses proven mechanisms such as cryptographic challenges and packet-tagging. Our analysis of the previous attempts to solve this problem led to a ground-up design of the protocol with adaptability in mind, trying to minimize deployment and adoption barriers. With this work we concluded that with software changes only on the communication endpoints, it is possible to mitigate the most used DDoS attacks with results up to 25 times more favourable than standard resource rate limiting (RRL) methods

Santarém e a Reconquista: a tomada da cidade em 1147

A presente dissertação debruça-se sobre a tomada de Santarém, que ocorreu na madrugada de 15 de março de 1147. O trabalho foi dividido em três capítulos, cada um com a sua própria temática e metodologia. Assim sendo, o primeiro capítulo é sobretudo introdutório, dando a conhe-cer, de forma muito genérica, o processo da Reconquista em território português desde a conquista definitiva de Coimbra (1064) até 1146, ano da véspera da tomada de Santarém. Para além disso, recorrendo às fontes árabes, procedeu-se também ao levantamento da ocupação muçulmana em toda a linha do Tejo durante o período em estudo, terminado com a análise dos exércitos cristãos e muçulmanos e respetivas estruturas defensivas. O segundo capítulo procura já entrar na principal temática do trabalho. Nele pre-tendemos abordar a importância geoestratégica de Santarém no plano da Reconquista, ao mesmo tempo que fazemos o estudo das suas estruturas e sistemas defensivos à data da conquista desta praça. Os preparativos para o assalto também são abordados neste capí-tulo. Por fim, o terceiro e último capítulo trata do assalto à vila escalabitana, dando a conhecer a viagem que o exército cristão tomou desde Coimbra até Santarém, assim como toda a ação militar que se desenrolou na dita madrugada e as suas consequências para o futuro da Reconquista em território português. A partir deste estudo concluímos que a tomada de Santarém marca uma mudança estratégica de Afonso Henriques, assim como uma mudança na arte de fazer a guerra em território português. Para além disso, e ao contrário do que se poderia pensar, Santarém não possuiria, afinal, muitas estruturas defensivas. O exército cristão que conquista a ci-dade escalabitana seria pequeno e não contaria com as principais figuras nobres, pelo que o sucesso deveu-se principalmente à missão de reconhecimento de Mem Ramires, o ver-dadeiro “cérebro” de toda a operação. Por fim, a tomada de Santarém permitiu os futuros ataques sobre Lisboa e além-Tejo e ainda consolidar a presença cristã na linha do Tejo.The present study focuses on the conquest of Santarém, which occurred in the early hours of March 15, 1147. The assignment was divided in three chapters, each one with its own subject-mat-ter and methodology. Therefore, the first chapter is mainly introductory, and aims to know, very generically, the process of the Reconquista in Portuguese territory since the final conquest of Coimbra (1064) until 1146, the year before the conquest of Santarém. Furthermore, using Arab sources, a survey of Muslim occupation was also carried out along the Tagus during the period under study, ending with the analysis of Christian and Muslim armies and their defensive structures. The second chapter seeks to enter into the main theme of the assignment. In it we intend to address the geo-strategic importance of Santarém in the Reconquista plan, at the same time that we study its defensive structures and systems at the date of the conquest of this square. Preparations for the assault are also covered in this chapter. Finally, the third and last chapter deals with the assault on the Scalabitan village, making known the journey that the Christian army took from Coimbra to Santarém, as well as all the military action that took place in the said dawn and its consequences for the future of Reconquista in Portuguese territory. From this study we conclude that the conquest of Santarém marks a strategic change by Afonso Henriques, as well as a change in the art of waging war in Portuguese territory. Furthermore, and contrary to what one might think, Santarém would not have, in the end, many defensive structures. The Christian army that conquered the Scalabitan city would be small and would not have the main noble figures, so the success was mainly due to the reconnaissance mission of Mem Ramires, the real “brain” of the entire opera-tion. Finally, the conquest of Santarém allowed the future attacks against Lisbon and be-yond the Tagus and still consolidate the Christian presence on the Tagus line

Relação entre os estados de humor e a síndrome de Overtraining em jovens atletas

O presente estudo analisou a associação entre estados humor e Síndrome de Overtraining (SOT) em jovens atletas e as possíveis diferenças nos estados de humor e na SOT em função do nível competitivo e em função das idades. Métodos: No total, 219 jovens atletas, com idades compreendidas entre os 13 e os 17 anos (M = 14.81; DP = 1.35), foram considerados para análise deste estudo. Resultados: Os resultados demonstraram que existe uma relação positiva e significativa entre a depressão, o desajuste ao treino, a confusão (negativo) e a tensão com a SOT. Foram, também, encontradas diferenças significativas nos estados de humor hostilidade e depressão em função do nível competitivo e nos estados de humor confusão (positivo) e hostilidade em função da idade. Conclusão Estes dados indicam, não só, que existe uma associação positiva entre estados de humor negativos e a SOT, como a existência de diferenças entre níveis competitivos e entre idades, sendo, por isso, necessário ter em conta essas variáveis.info:eu-repo/semantics/publishedVersio

A Pipeline for Clustering by Compression with Application to Patient Stratification in Spondyloarthritis

Funding Information: The authors acknowledge Fundação para a Ciência e Tecnologia, LASIGE Research Unit, ref. UIDB/00408/2020 and ref. UIDP/00408/2020 and Instituto de Telecomunicações Research Unit, ref. UIDB/50008/2020, and UIDP/50008/2020. The authors also acknowledge the Project PREDICT (PTDC/CCI-CIF/29877/2017), funded by Fundo Europeu de Desenvolvimento Regional (FEDER), through Programa Operacional Regional LISBOA (LISBOA2020), and by national funds, through Fundacção para a Ciência e Tecnologia (FCT), and projects MATISSE (DSAIPA/DS/0026/2019), MONET (PTDC/CCI-BIO/4180/2020) and SmartGlauco (PTDC/CTM-REF/2679/2020). Publisher Copyright: © 2023 by the authors.The normalized compression distance (NCD) is a similarity measure between a pair of finite objects based on compression. Clustering methods usually use distances (e.g., Euclidean distance, Manhattan distance) to measure the similarity between objects. The NCD is yet another distance with particular characteristics that can be used to build the starting distance matrix for methods such as hierarchical clustering or K-medoids. In this work, we propose Zgli, a novel Python module that enables the user to compute the NCD between files inside a given folder. Inspired by the CompLearn Linux command line tool, this module iterates on it by providing new text file compressors, a new compression-by-column option for tabular data, such as CSV files, and an encoder for small files made up of categorical data. Our results demonstrate that compression by column can yield better results than previous methods in the literature when clustering tabular data. Additionally, the categorical encoder shows that it can augment categorical data, allowing the use of the NCD for new data types. One of the advantages is that using this new feature does not require knowledge or context of the data. Furthermore, the fact that the new proposed module is written in Python, one of the most popular programming languages for machine learning, potentiates its use by developers to tackle problems with a new approach based on compression. This pipeline was tested in clinical data and proved a promising computational strategy by providing patient stratification via clusters aiding in precision medicine.publishersversionpublishe

Development of biocompatible plasmonic thin films composed of noble metal nanoparticles embedded in a dielectric matrix to enhance Raman signals

This work focused on the production of nanocomposite thin films, composed of noble nanoparticles embedded in a dielectric matrix, to be tested as biocompatible plasmonic platforms for detection of molecules using Surface Enhance Raman Spectroscopy (SERS). Three different thin films systems were deposited by reactive DC magnetron sputtering, namely Au-Al2O3, Au-TiO2 and Ag-TiO2. The depositions were followed by a thermal treatment at different temperatures to promote the growth of the nanoparticles. Localized Surface Plasmon Resonance (LSPR) bands appeared already at 300 °C, related to the presence of Au nanoparticles, and at 500 °C in the case of Ag nanoparticles. Furthermore, at 700 °C, the Ag-TiO2 films showed a broadband optical response due to the formation of Ag clusters at the film's surface. The biological experiments showed that the presence of the thin films didn't affect the growth of C. albicans, which is very convenient if one needs to detect low concentrations of this microorganism using SERS platforms. As for the SERS measurements, an enhancement of R6G Raman spectra intensity was clearly perceivable, but only for the TiO2 matrix. Furthermore, the application of a plasma treatment allowed to better expose the nanoparticles, providing a further enhancement of Raman signals.FCT - Fundação para a Ciência e a Tecnologia (PTDC/FIS-NAN/1154/2014

Abordagem das atividades rítmicas expressivas na EF

info:eu-repo/semantics/publishedVersio

Color stability, surface roughness and microhardness of composites submitted to mouthrinsing action

OBJECTIVE:The purpose of this study was to evaluate the effect of mouth rinse solutions on color stability, surface roughness and microhardness of two composite resins. MATERIAL AND METHODS: Fifty test specimens of each composite (Filtek Z250 and Z350; 3M ESPE) were made using a teflon matrix (12x2 mm). Color, surface roughness and Knoop microhardness baseline measurements of each specimen were made and specimens (n=10) were immersed in 5 mouth rinse solutions: G1: distilled water (control), G2: Plax Classic, G3: Plax alcohol-free; G4: Periogard, and G5: Listerine. Final measurements of color, roughness and microhardness were performed and the results submitted to statistical analysis (2-way ANOVA, Bonferroni s test;

Criação do percevejo-verde usando dieta artificial seca e planta artificial

Laboratory and greenhouse studies were conducted with an artificial dry diet to rear nymphs, and with an artificial plant as substrate for egg laying by the southern green stink bug, Nezara viridula (L.). The artificial diet was composed of: soybean protein (15 g); potato starch (7.5 g); dextrose (7.5 g); sucrose (2.5 g); cellulose (12.5 g); vitamin mixture (niacinamide 1 g, calcium pantothenate 1 g, thiamine 0.25 g, riboflavin 0.5 g, pyridoxine 0.25 g, folic acid 0.25 g, biotin 0.02 mL, vitamin B12 1 g – added to 1,000 mL of distilled water) (5.0 mL); soybean oil (20 mL); wheat germ (17.9 g); and water (30 mL). Nymphs showed normal feeding behavior when fed on the artificial diet. Nymphal development time was longer than or similar to that of nymphs fed on soybean pods. Total nymphal mortality was low (ca. 30%), both for nymphs reared on the artificial diet, and for nymphs fed on soybean pods. At adult emergence, fresh body weights were significantly (P < 0.01) less on the artificial diet than on soybean pods. Despite the lower adult survivorship and fecundity on artificial plants than on soybean plants, it was demonstrated for the first time that a model simulating a natural plant, can be used as a substrate for egg mass laying, in conjunction with the artificial diet.Foram conduzidos estudos em laboratório e em casa de vegetação, com uma dieta artificial seca para a criação de ninfas e com um modelo de planta artificial como substrato para a colocação de ovos por adultos do percevejo-verde, Nezara viridula (L.). Os componentes da dieta artificial foram: proteína de soja (15 g); fécula de batata (7,5 g); dextrose (7,5 g); sacarose (2,5 g); celulose (12,5 g); mistura vitamínica (niacinamida 1 g, pantotenato de cálcio 1 g, tiamina 0,25 g, riboflavina 0,5 g, piridoxina 0,25 g, ácido fólico 0,25 g, biotina 0,02 mL, vitamina B12 1 g, adicionada em 1.000 mL de água destilada) (5,0 mL); óleo de soja (20 mL); germe de trigo (17,9 g); e água (30 mL). As ninfas alimentaram-se normalmente da dieta, embora o tempo de desenvolvimento tenha sido em um caso, maior, e em outro, semelhante, ao das ninfas que se alimentaram de vagens da soja. A mortalidade total das ninfas foi baixa (ca. 30%), tanto na dieta como na vagem de soja. Na emergência, os adultos apresentaram peso fresco significativamente (P < 0,01) menor na dieta que na soja. Apesar de a sobrevivência e a fecundidade terem sido menores nas plantas artificiais do que na soja, fica demonstrado, pela primeira vez, que um modelo simulando uma planta natural pode ser usado como substrato para oviposição pelo percevejo N. viridula, em conjunto com a dieta artificial

Successful management of bilateral orbital metastases from invasive lobular breast cancer with abemaciclib and letrozole: a case report and literature review

Breast cancer is a significant global health concern, contributing to substantial morbidity and mortality among women. Hormone receptor-positive (HR+)/HER2-negative (HER2-) breast cancer constitutes a considerable proportion of cases, and significant advancements have been made in its management. CDK4/6 inhibitors (CDK4/6is) are a new targeted therapy that has demonstrated efficacy in adjuvant, advanced and metastatic settings. The propensity of lobular breast carcinomas for estrogen-rich sites, such as periocular tissues and orbital fat, may explain their tendency for orbital metastases. Current treatment strategies for these cases are predominantly palliative, and the prognosis remains poor. This article presents a unique case of a 51-year-old female with progressive right periorbital edema, pain, and limited ocular motility. An imaging work-up showed bilateral intra and extraconal orbital infiltration, which was biopsied. The histopathologic analysis disclosed mild chronic inflammatory infiltrate with thickened fibrous tissue and moderately differentiated lobular carcinoma cells, positive for GATA3 and CK7 markers, with 100% of tumor nuclei expressing estrogen receptors (ER+). A systemic evaluation showed a multicentric nodular formation in both breasts. Further diagnostic assessments unveiled an HR+/HER2- bilateral lobular breast carcinoma with synchronous bilateral orbital metastases. Systemic treatment was initiated with abemaciclib 150mg twice daily and letrozole 2.5mg once a day. However, this regimen was interrupted due to toxicity. After two weeks, treatment was resumed with a reduced abemaciclib dose (100mg twice daily) alongside letrozole, with a reasonable tolerance. Nearly two years after the initial diagnosis of inoperable metastatic cancer, the patient remains on the same systemic treatment regimen with no signs of invasive disease. This case report is the first of a patient presenting with bilateral orbital metastases from bilateral lobular breast cancer, showing an impressive and sustained response to a first-line treatment regimen combining abemaciclib and letrozole. A literature review on bilateral orbital metastases from breast cancer is also presented