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

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

Evolutive follow-up of the photocatalytic degradation of real textile effluents in TiO2 and TiO2/H2O2 systems and their toxic effects on Lactuca sativa seedlings

Textile industry wastes raise a great concern due to their strong coloration and toxicity. The objective of the present work was to characterize the degradation and mineralization of textile effluents by advanced oxidative processes using either TiO2 or TiO2/H2O2 association and to monitor the toxicity of the products formed during 6 h irradiation in relation to that of the in natura effluent. The results obtained demonstrated that the TiO2/H2O2 association was more efficient in the mineralization of textile effluents than TiO2 alone, with high mineralized ion concentrations (NH4+, NO3-, and SO4(2-)) and significant organic matter reduction rates (represented by the COD and TOC). The toxicity of the degradation products to lettuce seeds (Lactuca sativa) was not significant, since percent germination was not significantly affected and neither was root and sprout percent growth. However, while the TiO2/H2O2 association was more toxic in the first hours of irradiation and less so in the end of the 6 h irradiation, the toxicity of TiO2 increased only slightly in the end of the experiments. Comparatively, the photogenerated products of both the TiO2 and the TiO2/H2O2 association were less toxic than the in natura effluent

Local Power as the Basis of the Understanding of the Federative Pact

The research aimed to describe the existing problems in the relationship between City, State and Federal Government, through the Brazilian Federative Pact, mainly for municipalities with population of less than 50,000 inhabitants. The research is structured from a qualitative perspective. The theoretical framework was built from the local power of the discussion based on the understanding of the federal pact and local interest and the municipality in Brazil. The paper argues that the federal pact is little debated, discussed, much less questioned by society in general, it only strengthens the lack of a legal and institutional framework for coordination and cooperation among federal entities in the country, which results in public policy fragmented the territory and without direction, causing waste of public resources

Factor Analysis and the Social Capital Index: A Study at the Brazil / Bolivia Border

Objective: The study aimed to build the level of social capital by neighborhoods Guajará-Mirim border region between the State of Rondônia, Brazil and the Republic of Bolivia, which in recent years has been showing signs of social fragility due advance not virtuous practices. Method: This work made use of research in secondary bases as well as in primary bases. The tabulation of qualitative and quantitative data was performed in Excel (2010) and for their processing performance index construction purposes were calculated following the factorial analysis techniques presented by Hair et al. [19] Santana [20, 21]; and Choi [22]. For this, we made use of the statistical tool SPSS (Statistical Package for Social Sciences) for the construction of the indices of social capital. The correlation analysis process was done in Excel. results: It was observed that the capital reached regular levels in Guajará-Mirim neighborhoods not observable, so correlations between the studied parameters, however, it needs to be further studied as factors such as the flooding of the Mamore river may have interfered in any way in the implementation process of the field survey to the residents of the city. It became clear that the municipality of Guajará-Mirim suffers from serious social problems and that most problems are correlated with the increase in alcoholic beverage market in the city and use drugs. However, was not observed as the institutional arrangements are dealing with this problem, that is, as public bodies are relating to discuss actions for concrete solutions to this evil that plagues large portion of the population of Guajará-Mirim, mainly young teenagers residents of Guajá-Mamim. However, we hope to continue this work in order to better understand this mechanism of social network between the actors of this process in the region

Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A) and Cratylia mollis (Cramoll 1 and Cramoll 1, 4) did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column

Hygienisation, gentrification, and urban displacement in Brazil

This article engages recent debates over gentrification and urban displacement in the global South. While researchers increasingly suggest that gentrification is becoming widespread in “Southern” cities, others argue that such analyses overlook important differences in empirical context and privilege EuroAmerican theoretical frameworks. To respond to this debate, in this article, we outline the concept of higienização (hygienisation), arguing that it captures important contextual factors missed by gentrification. Hygienisation is a Brazilian term that describes a particular form of urban displacement, and is directly informed by legacies of colonialism, racial and class stigma, informality, and state violence. Our objective is to show how “Southern” concepts like hygienisation help urban researchers gain better insight into processes of urban displacement, while also responding to recent calls to decentre and provincialise urban theory

Reprogramming energy metabolism and inducing angiogenesis : co-expression of monocarboxylate transporters with VEGF family members in cervical adenocarcinomas

Background: Deregulation of cellular energetic metabolism was recently pointed out as a hallmark of cancer cells. This deregulation involves a metabolic reprogramming that leads to a high production of lactate. Lactate efflux, besides contributing for the glycolytic flux, also acts in the extracellular matrix, contributing for cancer malignancy, by, among other effects, induction of angiogenesis. However, studies on the interplay between cancer metabolism and angiogenesis are scarce. Therefore, the aim of the present study was to evaluate the metabolic and vascular molecular profiles of cervical adenocarcinomas, their co-expression, and their relation to the clinical and pathological behavior. Methods: The immunohistochemical expression of metabolism-related proteins (MCT1, MCT4, CD147, GLUT1 and CAIX) as well as VEGF family members (VEGF-A, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2 and VEGFR-3) was assessed in a series of 232 cervical adenocarcinomas. The co-expression among proteins was assessed and the expression profiles were associated with patients’ clinicopathological parameters. Results: Among the metabolism-related proteins, MCT4 and CAIX were the most frequently expressed in cervical adenocarcinomas while CD147 was the less frequently expressed protein. Overall, VEGF family members showed a strong and extended expression with VEGF-C and VEGFR-2 as the most frequently expressed and VEGFR-1 as the less expressed member. Co-expression of MCT isoforms with VEGF family members was demonstrated. Finally, MCT4 was associated with parametrial invasion and HPV18 infection, CD147 and GLUT1 with distant metastasis, CAIX with tumor size and HPV18 infection, and VEGFR-1 with local and lymphnode metastasis. Conclusions: The results herein presented provide additional evidence for a crosstalk between deregulating cellular energetics and inducing angiogenesis. Also, the metabolic remodeling and angiogenic switch are relevant to cancer progression and aggressiveness in adenocarcinomas.CP received a post-doctoral fellowship (SFRH/BPD/69479/2010) and FM-S received a doctoral fellowship (SFRH/BD/87139/2012) from FCT (Portuguese Foundation for Science and Technology). This work was supported by the FCT grant ref. PTDC/SAU-FCF/104347/2008, under the scope of "Programa Operacional Tematico Factores de Competitividade" (COMPETE) of "Quadro Comunitario de Apoio III" and co-financed by Fundo Comunitario Europeu FEDER, and also by FAPESP 2008/03232-1