iRED: A disaggregated P4-AQM fully implemented in programmable data plane hardware

Routers employ queues to temporarily hold packets when the scheduler cannot immediately process them. Congestion occurs when the arrival rate of packets exceeds the processing capacity, leading to increased queueing delay. Over time, Active Queue Management (AQM) strategies have focused on directly draining packets from queues to alleviate congestion and reduce queuing delay. On Programmable Data Plane (PDP) hardware, AQMs traditionally reside in the Egress pipeline due to the availability of queue delay information there. We argue that this approach wastes the router's resources because the dropped packet has already consumed the entire pipeline of the device. In this work, we propose ingress Random Early Detection (iRED), a more efficient approach that addresses the Egress drop problem. iRED is a disaggregated P4-AQM fully implemented in programmable data plane hardware and also supports Low Latency, Low Loss, and Scalable Throughput (L4S) framework, saving device pipeline resources by dropping packets in the Ingress block. To evaluate iRED, we conducted three experiments using a Tofino2 programmable switch: i) An in-depth analysis of state-of-the-art AQMs on PDP hardware, using 12 different network configurations varying in bandwidth, Round-Trip Time (RTT), and Maximum Transmission Unit (MTU). The results demonstrate that iRED can significantly reduce router resource consumption, with up to a 10x reduction in memory usage, 12x fewer processing cycles, and 8x less power consumption for the same traffic load; ii) A performance evaluation regarding the L4S framework. The results prove that iRED achieves fairness in bandwidth usage for different types of traffic (classic and scalable); iii) A comprehensive analysis of the QoS in a real setup of a DASH) technology. iRED demonstrated up to a 2.34x improvement in FPS and a 4.77x increase in the video player buffer fill.Comment: Preprint (TNSM under review

Identification of gifted students by teachers: reliability and validity of the Cognitive Abilities and Learning Scale

Teachers play a relevant role in screening and identifying gifted and talented students. However, many times teacher´s assessments may be biased by personal beliefs about giftedness. In these cases, the quality of screening and identification can be enhanced through the use of measurement devices that present good psychometric properties of validity and reliability. This study presents the examination of the precision and factor validity of the Cognitive Abilities and Learning Scale (CALS: Escala de Habilidades Cognitivas e de Aprendizagem – EHC/A; Almeida, Olivira &Melo, 2000), with a sample of 262 students from fourth and fifth grades. Results suggest the existence of only one factor, not confirming the theoretical model of three factors (intellectual ability, motivation and creativity) that supports the scale. Principal components analysis for three factors shows some problems with item specification for ability and creativity. These problems contrast with high reliability coefficients obtained when arranging items according to the dimension they would theoretically be linked to. These findings suggest the need to include new items with more specificity in terms of the cognitive dimensions of giftedness

Information processing among high-performance managers

O propósito deste estudo foi avaliar o processamento da informação de 43 gestores empresariais de desempenho superior. No seu enquadramento teórico recorremos a três modelos: a Teoria dos Papéis Gerenciais de Henry Mintzberg, a Teoria do Processamento da Informação e o Modelo de Processo de Resposta ao Rorschach de John Exner. A ava-liação dos sujeitos recorreu ao método do Rorschach. Os resultados deste estudo mos-traram que esses gerentes são capazes de recolher dados, avaliá-los e estabelecer ran-kings de maneira adequada. Ao mesmo tempo, verifica-se que são capazes de ser objeti-vos e precisos na avaliação dos problemas. Este estilo de processamento de informação possibilita uma interpretação do mundo a partir de um modo de processamento ou de um estilo cognitivo, próprio e característico.The purpose of this study was to evaluate the information processing of 43 business managers with a professional superior performance. The theoretical framework consid-ers three models: the Theory of Managerial Roles of Henry Mintzberg, the Theory of In-formation Processing, and Process Model Response to Rorschach by John Exner. The participants have been evaluated by Rorschach method. The results show that these managers are able to collect data, evaluate them and establish rankings properly. At same time they are capable of being objective and accurate in the problems assessment. This information processing style permits an interpretation of the world around on basis of a very personal and characteristic processing way or cognitive style.Fundação para a Ciência e a Tecnologia (FCT), no âmbito do Fundo de Apoio à Comunidade Científica - Edição de Publicações Periódicas de Natureza Científica

DESiRED -- Dynamic, Enhanced, and Smart iRED: A P4-AQM with Deep Reinforcement Learning and In-band Network Telemetry

Active Queue Management (AQM) is a mechanism employed to alleviate transient congestion in network device buffers, such as routers and switches. Traditional AQM algorithms use fixed thresholds, like target delay or queue occupancy, to compute random packet drop probabilities. A very small target delay can increase packet losses and reduce link utilization, while a large target delay may increase queueing delays while lowering drop probability. Due to dynamic network traffic characteristics, where traffic fluctuations can lead to significant queue variations, maintaining a fixed threshold AQM may not suit all applications. Consequently, we explore the question: \textit{What is the ideal threshold (target delay) for AQMs?} In this work, we introduce DESiRED (Dynamic, Enhanced, and Smart iRED), a P4-based AQM that leverages precise network feedback from In-band Network Telemetry (INT) to feed a Deep Reinforcement Learning (DRL) model. This model dynamically adjusts the target delay based on rewards that maximize application Quality of Service (QoS). We evaluate DESiRED in a realistic P4-based test environment running an MPEG-DASH service. Our findings demonstrate up to a 90x reduction in video stall and a 42x increase in high-resolution video playback quality when the target delay is adjusted dynamically by DESiRED.Comment: Preprint (Computer Networks under review

El impacto de las expectativas sobre la adaptación académica de los estudiantes en la Educación Superior

Os desafios enfrentados pelos jovens, decorrentes do ingresso no Ensino Superior, têm sido alvo de inúmeras pesquisas, destacando a confluência de variáveis pessoais e contextuais nesse processo de transição e adaptação ao Ensino Superior. O presente estudo teve como objetivo investigar como as expectativas afetam a qualidade das vivências adaptativas dos acadêmicos que iniciam o Ensino Superior. Participaram deste estudo 182 estudantes brasileiros (M=26,2; DP=8,76), sendo 146 mulheres e 36 homens, que responderam a dois questionários reportados às expectativas e vivências acadêmicas. Os resultados indicaram que as expectativas iniciais dos ingressantes foram correlacionadas com a qualidade das suas vivências acadêmicas. Em particular, as expectativas de envolvimento nas relações com os colegas, no projeto vocacional de carreira e nas atividades curriculares do seu curso foram associadas à adaptação acadêmica dos estudantes.Many studies have addressed the challenges faced by students when they access higher education, describing the influence of personal and contextual factors on the transition and adaptation to Higher Education. The present study aimed to investigate how expectations impact the quality of first-year students’ experiences. Participants included 182 Brazilian students (M=26,2; DP=8,76), 146 women and 36 men, who answered two questionnaires focusing on academic expectations and experiences. Results suggest that initial expectations of first-year students are correlated with the quality of their academic experiences. Specifically, expectations about students’ engagement with colleagues, career project, and curricular activities in their undergraduate program, seem to be related with students’ academic adaptation.Los desafíos que enfrentan los jóvenes que resultan del ingreso a la educación superior han sido objeto de numerosas investigaciones, destacando la convergencia de variables personales y contextuales en este proceso de transición y adaptación a la educación superior. El presente estudio tuvo como objetivo investigar cómo las expectativas afectan la calidad de las experiencias de adaptación de los estudiantes que inician la educación superior. Participaron 182 estudiantes brasileños (M=26,2; DP=8,76), siendo 146 mujeres y 36 hombres, que respondieron dos cuestionarios direccionados a las expectativas y experiencias académicas. Los resultados indicaron que las expectativas iniciales de los estudiantes ingresantes se correlacionaron con la calidad de sus experiencias académicas. En particular, las expectativas de participación en las relaciones con los compañeros, en el proyecto de la carrera y en las actividades curriculares del curso fueron relacionadas con la adaptación académica de los estudiantes.Universidade do MinhoUniversidade Salgado de Oliveir

Expetativas académicas de estudantes universitários em Moçambique: validação de uma versão do questionário de perceções académicas (QPA – expetativas)

O ensino superior em Moçambique atravessa mudanças, quer a nível da expansão, quer do volume de alunos que acedem. Esta crescente procura por parte dos jovens moçambicanos está relacionada com elevadas expetativas dos jovens e das famílias a uma formação académica de nível superior, que possibilite o seu melhor enquadramento profissional e social no futuro. Neste sentido, as expectativas académicas dos estudantes são um fator determinante do seu compromisso com a formação e a vida académica, explicando a sua permanência no curso e o seu sucesso académico. Neste artigo apresentamos o processo de adaptação e validação de uma versão do Questionário de Perceções Académicas: Expetativas, à realidade moçambicana. O estudo de validação considerou uma amostra de 210 estudantes inscritos para realizarem exames de admissão para ingresso na Universidade Pedagógica no ano académico de 2014. Os resultados parecem mostrar alguma indefinição dos estudantes nas suas expetativas, uma vez que itens das várias dimensões teóricas se repartem pelos diferentes fatores isolados na análise fatorial.Fundação para a Ciência e a Tecnologia (FCT)Universidade do Minh

Genotoxic and Cytotoxic Safety Evaluation of Papain (Carica papaya L.) Using In Vitro Assays

Papain, a phytotherapeutic agent, has been used in the treatment of eschars and as a debriding chemical agent to remove damaged or necrotic tissue of pressure ulcers and gangrene. Its benefits in these treatments are deemed effective, since more than 5000 patients, at the public university hospital at Rio de Janeiro, Brazil, have undergone papain treatment and presented satisfactory results. Despite its extensive use, there is little information about toxic and mutagenic properties of papain. This work evaluated the toxic and mutagenic potential of papain and its potential antioxidant activity against induced-H2O2 oxidative stress in Escherichia coli strains. Cytotoxicity assay, Growth inhibition test, WP2-Mutoxitest and Plasmid-DNA treatment, and agarose gel electrophoresis were used to investigate if papain would present any toxic or mutagenic potential as well as if papain would display antioxidant properties. Papain exhibited negative results for all tests. This agent presented an activity protecting cells against H2O2-induced mutagenesis

An Earth-Mass Planet In A Time Of Covid-19: Kmt-2020-Blg-0414Lb

We report the discovery of KMT-2020-BLG-0414Lb, with a planet-to-host mass ratio q (2) = 0.9-1.2 x 10(-5) = 3-4 circle plus at 1 sigma, which is the lowest mass-ratio microlensing planet to date. Together with two other recent discoveries (4 less than or similar to q/q (circle plus) less than or similar to 6), it fills out the previous empty sector at the bottom of the triangular (log s, log q) diagram, where s is the planet-host separation in units of the angular Einstein radius theta E. Hence, these discoveries call into question the existence, or at least the strength, of the break in the mass-ratio function that was previously suggested to account for the paucity of very low-q planets. Due to the extreme magnification of the event, A (max) similar to 1450 for the underlying single-lens event, its light curve revealed a second companion with q (3) similar to 0.05 and |log s (3)| similar to 1, i.e., a factor similar to 10 closer to or farther from the host in projection. The measurements of the microlens parallax pi (E) and the angular Einstein radius theta E allow estimates of the host, planet and second companion masses, (M (1), M (2), M (3)) similar to (0.3 M (circle dot), 1.0 M (circle plus), 17 M-J ), the planet and second companion projected separations, (a (perpendicular to,2), a (perpendicular to,3)) similar to (1.5, 0.15 or 15) au, and system distance D (L) similar to 1 kpc. The lens could account for most or all of the blended light (I similar to 19.3) and so can be studied immediately with high-resolution photometric and spectroscopic observations that can further clarify the nature of the system. The planet was found as part of a new program of high-cadence follow-up observations of high-magnification events. The detection of this planet, despite the considerable difficulties imposed by COVID-19 (two KMT sites and OGLE were shut down), illustrates the potential utility of this program

Identification and analysis of seven effector protein families with different adaptive and evolutionary histories in plant-associated members of the Xanthomonadaceae.

The Xanthomonadaceae family consists of species of non-pathogenic and pathogenic γ-proteobacteria that infect different hosts, including humans and plants. In this study, we performed a comparative analysis using 69 fully sequenced genomes belonging to this family, with a focus on identifying proteins enriched in phytopathogens that could explain the lifestyle and the ability to infect plants. Using a computational approach, we identified seven phytopathogen-enriched protein families putatively secreted by type II secretory system: PheA (CM-sec), LipA/LesA, VirK, and four families involved in N-glycan degradation, NixE, NixF, NixL, and FucA1. In silico and phylogenetic analyses of these protein families revealed they all have orthologs in other phytopathogenic or symbiotic bacteria, and are involved in the modulation and evasion of the immune system. As a proof of concept, we performed a biochemical characterization of LipA from Xac306 and verified that the mutant strain lost most of its lipase and esterase activities and displayed reduced virulence in citrus. Since this study includes closely related organisms with distinct lifestyles and highlights proteins directly related to adaptation inside plant tissues, novel approaches might use these proteins as biotechnological targets for disease control, and contribute to our understanding of the coevolution of plant-associated bacteria