La ràpida evolució d’Internet i l’àmplia gamma de noves aplicacions (per exemple, multimèdia, videoconferència, jocs en línia, etc.) ha fomentat canvis revolucionaris en la manera com ens comuniquem. A més, algunes d’aquestes aplicacions demanden grans quantitats de recursos d’ample de banda amb diversos requeriments de qualitat de servei (QoS). El desenvolupament de la multiplexació per divisió de longitud d’ona (WDM) en els anys noranta va fer molt rendible la disponibilitat d’ample de banda. Avui dia, les tecnologies de commutació òptica de circuits són predominants en el nucli de la xarxa, les quals permeten la configuració de canals (lightpaths) a través de la xarxa. No obstant això, la granularitat d’aquests canals ocupa tota la longitud d’ona, el que fa que siguin ineficients per a proveir canals de menor ample de banda (sub-longitud d’ona). Segons la comunitat científica, és necessari augmentar la transparència dels protocols, així com millorar l’aprovisionament d’ample de banda de forma dinàmica. Per tal de fer això realitat, és necessari desenvolupar noves arquitectures. La commutació òptica de ràfegues i de paquets (OBS/OPS), són dues de les tecnologies proposades. Aquesta tesi contribueix amb tres arquitectures de xarxa destinades a millorar el transport de dades sub-longitud d’ona. En primer lloc, aprofundim en la naturalesa sense connexió en OBS. En aquest cas, la xarxa incrementa el seu dinamisme a causa de les transmissions a ràfega. A més, les col·lisions entre ràfegues degraden el rendiment de la xarxa fins i tot a càrregues molt baixes. Per fer front a aquestes col·lisions, es proposa un esquema de resolució de col·lisions pro actiu basat en un algorisme d’encaminament i assignació de longitud d’ona (RWA) que balanceja de forma automàtica i distribuïda la càrrega en la xarxa. En aquest protocol, el RWA i la transmissió de ràfegues es basen en l’explotació i exploració de regles de commutació que incorporen informació sobre contencions i encaminament. Per donar suport a aquesta arquitectura, s’utilitzen dos tipus de paquets de control per a l’encaminament de les ràfegues i l’actualització de les regles de commutació, respectivament. Per analitzar els beneficis del nou algorisme, s’utilitzen quatre topologies de xarxa diferents. Els resultats indiquen que el mètode proposat millora en diferents marges la resta d’algorismes RWA en funció de la topologia i sense penalitzar altres paràmetres com el retard extrem a extrem. La segona contribució proposa una arquitectura híbrida sense i orientada a connexió sobre la base d’un protocol de control d’accés al medi (MAC) per a xarxes OBS (DAOBS). El MAC ofereix dos mètodes d’accés: arbitratge de cua (QA) per a la transmissió de ràfegues sense connexió, i pre-arbitratge (PA) per serveis TDM orientats a connexió. Aquesta arquitectura permet una àmplia gamma d’aplicacions sensibles al retard i al bloqueig. Els resultats avaluats a través de simulacions mostren que en l’accés QA, les ràfegues de més alta prioritat tenen garantides zero pèrdues i latències d’accés molt baixes. Pel que fa a l’accés PA, es reporta que la duplicació de la càrrega TDM augmenta en més d’un ordre la probabilitat de bloqueig, però sense afectar en la mateixa mesura les ràfegues sense connexió. En aquest capítol també es tracten dos dels problemes relacionats amb l’arquitectura DAOBS i el seu funcionament. En primer lloc, es proposa un model matemàtic per aproximar el retard d’accés inferior i superior com a conseqüència de l’accés QA. En segon lloc, es formula matemàticament la generació i optimització de les topologies virtuals que suporten el protocol per a l’escenari amb tràfic estàtic. Finalment, l’última contribució explora els beneficis d’una arquitectura de xarxa òptica per temps compartit (TSON) basada en elements de càlcul de camins (PCE) centralitzats per tal d’evitar col·lisions en la xarxa. Aquesta arquitectura permet garantir l’aprovisionament orientat a connexió de canals sub-longitud d’ona. En aquest capítol proposem i simulem tres arquitectures GMPLS/PCE/TSON. A causa del enfocament centralitzat, el rendiment de la xarxa depèn en gran mesura de l’assignació i aprovisionament de les connexions. Amb aquesta finalitat, es proposen diferents algorismes d’assignació de ranures temporals i es comparen amb les corresponents formulacions de programació lineal (ILP) per al cas estàtic. Per al cas de tràfic dinàmic, proposem i avaluem mitjançant simulació diferents heurístiques. Els resultats mostren els beneficis de proporcionar flexibilitat en els dominis temporal i freqüencial a l’hora d’assignar les ranures temporals. / The rapid evolving Internet and the broad range of new data applications (e.g., multimedia, video-conference, online gaming, etc.) is fostering revolutionary changes in the way we communicate. In addition, some of these applications demand for unprecedented amounts of bandwidth resources with diverse quality of service (QoS). The development of wavelength division multiplexing (WDM) in the 90's made very cost-effective the availability of bandwidth. Nowadays, optical circuit switching technologies are predominant in the core enabling the set up of lightpaths across the network. However, full-wavelength lightpath granularity is too coarse, which results to be inefficient for provisioning sub-wavelength channels. As remarked by the research community, an open issue in optical networking is increasing the protocol transparency as well as provisioning true dynamic bandwidth allocation at the network level. To this end, new architectures are required. Optical burst/packet switching (OBS/OPS) are two such proposed technologies under investigation. This thesis contributes with three network architectures which aim at improving the sub-wavelength data transport from different perspectives. First, we gain insight into the connectionless nature of OBS. Here, the network dynamics are increased due to the short-lived burst transmissions. Moreover, burst contentions degrade the performance even at very low loads. To cope with them, we propose a proactive resolution scheme by means of a distributed auto load-balancing routing and wavelength assignment (RWA) algorithm for wavelength-continuity constraint networks. In this protocol, the RWA and burst forwarding is based on the exploitation and exploration of switching rule concentration values that incorporate contention and forwarding desirability information. To support such architecture, forward and backward control packets are used in the burst forwarding and updating rules, respectively. In order to analyze the benefits of the new algorithm, four different network topologies are used. Results indicate that the proposed method outperforms the rest of tested RWA algorithms at various margins depending on the topology without penalizing other parameters such as end-to-end delay. The second contribution proposes a hybrid connectionless and connection-oriented architecture based on a medium access control (MAC) protocol for OBS networks (DAOBS). The MAC provides two main access mechanisms: queue arbitrated (QA) for connectionless bursts and pre-arbitrated (PA) for TDM connection-oriented services. Such an architecture allows for a broad range of delay-sensitive applications or guaranteed services. Results evaluated through simulations show that in the QA access mode highest priority bursts are guaranteed zero losses and very low access latencies. Regarding the PA mode, we report that doubling the offered TDM traffic load increases in more than one order their connection blocking, slightly affecting the blocking of other connectionless bursts. In this chapter, we also tackle two of the issues related with the DAOBS architecture and its operation. Firstly, we model mathematically the lower and upper approximations of the access delay as a consequence of the connectionless queue arbitrated access. Secondly, we formulate the generation of the virtual light-tree overlay topology for the static traffic case.

In this thesis, we present the spectral and timing variabilities of anomalous X-ray pulsar 1E 2259+586 observed with European Photon Imaging PN Camera (EPIC PN) on board X-ray Multi Mirror Mission (XMM), Proportional Counter Array (PCA) on board Rossi X-ray Timing Explorer (RXTE) and Advanced CCD Imaging Spectrometer (ACIS) on board Chandra X-ray Observatory. We presented the results of spectral analysis of 2000 January 11 ACIS observation. Pulse phase spectroscopy was performed on two XMM observations before and after the outburst. Pulse profiles of two XMM observations before the outburst and three XMM observations after the outburst were studied. Results are consistent with the those presented by Patel et al. (2001) and Woods et al. (2004). We searched for the spectral variations versus spin rate during the outburst. Long-term spectral, frequency and spin-down rate variations are presented between 1996 and 2006 including 98 RXTE and 4 XMM observations. However, except outburst region (Woods et al. 2004) no significant spectral and spin rate variabilities were seen. Around the outburst region we confirmed the spectral hardening with increasing spin rate and flux.

The disciplines of informatics and information visualization have developed in response to societal needs to find new insight in complex datasets and have been enabled by technological advancements. Joint application of these fields can demonstrate themes and connections that are otherwise not apparent. Methodological approaches, such as direct network analysis, can be applied to policy documents to determine if action or policy recommendations match the goals or objectives stated in the within the same documents. Informatics and information visualization can also be used to analyze changes of themes found within the documents over time. This paper seeks to leverage informatics and information visualization methodologies as a novel approach to policy analysis. In particular, directed network and time burst techniques are used to analyze water management policy documents for the State of Texas. The congruency between the stated goals or objectives and recommendations sections is evaluated at a topical level within each planning document and possible changes in important water policy concepts over time are highlighted by comparing among multiple planning documents. Although there limitations to the process at the time of publication due to the newness of the software utilized, this paper demonstrates that the products still lead to unique and insightful conclusions. / text

Τα σύγχρονα τηλεπικοινωνιακά δίκτυα οπτικών ινών χρησιμοποιούν την τεχνολογία WDM Wavelength Division Multiplexing) η οποία έχει κάνει εφικτή την αξιοποίηση – ως ένα βαθμό– του τεράστιου εύρους ζώνης της οπτικής ίνας. Στα πλαίσια της παρούσας διπλωματικής εργασίας θα παρουσιαστούν οι τρεις βασικές οπτικές αρχιτεκτονικές μεταγωγής (οπτική μεταγωγή κυκλώματος –OCS–, οπτική μεταγωγή πακέτου –OPS–, οπτική μεταγωγή ριπής–OBS–) οι οποίες μετατρέπουν τη διαθέσιμη χωρητικότητα σε ωφέλιμο throughput. Ιδιαίτερη έμφαση θα δοθεί στην αρχιτεκτονική OBS, η οποία έχει τραβήξει το ερευνητικό ενδιαφέρον τα τελευταία χρόνια, σαν μια ενδιαφέρουσα εναλλακτική της (ώριμης πλέον) αρχιτεκτονικής OCS. Συγκεκριμένα, θα διερευνηθεί η μετάδοση του TCP πρωτοκόλλου πάνω από OBS δίκτυα μέσα από λεπτομερείς προσομοιώσεις, και θα προταθούν κατάλληλες βελτιώσεις της αρχιτεκτονικής OBS. Ακόμα, θα περιγραφεί μια πρωτότυπη υβριδική αρχιτεκτονική οπτικής μεταγωγής ριπής. / Internet traffic has faced an exploding growth in recent years. The ever-growing demand for multimedia web services, as well as the advent of P2P technology, are driving core networks to their limits. This calls for the design of high capacity core networks, being able to serve the user’s high bandwidth requests. Optical networks have become a key part of the solution, mainly due to the vast capacity of optical fibers. Specifically, the advent of WDM technology has resulted in transmission capacities that have increased manifold in recent years. It is the router/switch throughput, however, that really transforms the raw bit rates into effective bandwidth. In this diploma thesis, we study the three basic optical architectures, that is Optical Circuit Switching (OCS), Optical Packet Switching (OPS) and Optical Burst Switching (OPS). Emphasis is given on OBS architecture, which has drawn research interest in recent year, as a possible replacement for the well-established OCS architecture. Specifically, we will study the transmission of TCP traffic over OBS networks through simulation, and propose modifications for the OBS architecture. Finally, a novel hybrid switch architecture will be proposed, combining the merits of OBS and OCS.

The goal of this thesis was to find agonists of Toll-like recptors that would interact with ligands of phagocytic receptors synergistically, would cause a strong suppresion of tumour growth, and could be safely used in human medicine.

GABA is the major inhibitory neurotransmitter in the central nervous system. It binds to two types of receptors –ionotropic GABAA and metabotropic GABAB. The GABAA receptor directly gates a Clionophore that causes hyperpolarization in mature excitatory neurons while GABAB receptor mediates a slower hyperpolarizing response via G-protein coupled receptor (GPCR) activated potassium channels. This signaling mechanism gets further complicated by the heterogeneous GABA receptor subunit composition that influences the response kinetics in the postsynaptic membrane. In this thesis, the focus has been to decipher the role of GABAA receptors in relation to cellular excitability in the subiculum under physiological and pathophysiological conditions. The subiculum, considered as the output structure of hippocampus, modulates information flow from hippocampus to various cortical and sub-cortical areas and has been implicated in learning and memory, rhythm generation and various neurological disorders. It gates hippocampal activity with its well orchestrated and fine tuned intrinsic and local network properties. Over the years many studies have shown the involvement of subiculum in temporal lobe epilepsy where it forms the focal point of epileptiform activities with altered cellular and network properties. The subiculum is characterized by the presence of a significant population of burst firing neurons that lead local epileptiform activity. By virtue of its bursting nature and recurrent connections, it is a potential site for seizure generation and maintenance. Epileptiform activities are dynamic in nature and change temporally and spatially according to the alterations in electrophysiological properties of neurons. Transitions to different electrical activities in neurons following a prolonged challenge with epileptogenic stimulus have been shown in other brain structures, but not in the subiculum. Considering the importance of the subicular burst firing neurons in the propagation of epileptiform activity to the entorhinal cortex, we have explored the phenomenon of electrophysiological phase transitions in the burst firing neurons of the subiculum in an in vitro brain slice model of epileptogenesis. Whole-cell patch clamp and extracellular field recordings revealed a distinct phenomenon in the subiculum wherein an early hyperexcitable phase was followed by a late suppressed phase upon continuous perfusion with epileptogenic 4-amino pyridine and magnesium-free medium. The late suppressed phase was characterized by inhibitory post-synaptic potentials (IPSPs) in pyramidal excitatory neurons and bursting activity in local fast spiking interneurons at a frequency of 0.1-0.8 Hz. The IPSPs were mediated by GABAA receptors that coincided with excitatory synaptic inputs to attenuate action potential discharge. These IPSPs ceased following a cut between the CA1 and subiculum. Our results suggest the importance of feedforward inhibition in the suppression of epileptiform activity in subiculum to mediate a homeostatic response towards the induced hyper-excitability. GABA release from presynaptic nerve endings activates postsynaptic GABAA receptors, which evoke faster phasic inhibitory postsynaptic currents (IPSCs) and non-inactivating inhibitory tonic current, mediated through extrasynaptic GABAA receptors. These receptors are heteropentameric GABA-gated channels assembled from 19 possible subunits (α1-6, β1-3, γ1-3, δ, π, ρ1-3, θ, and ε). The 2 major subunits involved in tonic GABAA currents in the hippocampus are α5 and δ subunits. Tonic GABAA receptor mediated inhibitory current plays an important role in neuronal physiology as well as pathophysiology such as mood disorders, insomnia, epilepsy, autism spectrum disorders and schizophrenia. While the alterations of various electrical properties due to tonic inhibition have been studied in neurons from different regions, its influence on intrinsic subthreshold resonance in pyramidal excitatory neurons having hyperpolarization-activated cyclic nucleotide-gated (HCN) channels is not known. In the present study, we show the involvement of α5βγ GABAA receptors in mediating picrotoxin sensitive tonic current in subicular pyramidal neurons using known pharmacological agents that target specific GABAA receptor subunits. We further investigated the contribution of tonic conductance in regulating subthreshold electrophysiological properties using current clamp and dynamic clamp experiments. Our experiments suggest that tonic GABAergic inhibition can actively modulate subthreshold properties of subicular pyramidal neurons including resonance due to HCNchannels that may potentially alter the response dynamics in an oscillating neuronal network.

Three CMEs which erupted on 2017 Sep 4 and 6 underwent mutual interaction before reaching Earth on Sep 6-9, where it gave rise to a complex and unexpectedly geoeffective structure as detected by WIND at L1. The spacecraft first observed an interplanetary (IP) shock on Sep 6 followed by a turbulent sheath. The leg of the CME flux rope is detected on Sep 7, in which clear signatures of a shock-in-a-cloud can be distinguished, coming from the third CME which propagated into the preceding flux rope. We model the source of this complex ejecta with WSA-ENLIL+Cone and EUHFORIA to assess and compare the overall performance for interacting CMEs as opposed to single CME events. We find that following the conventional algorithm for determination of input parameters give large deviation in the event prediction at L1. The overestimated density of the IP shock 1 is due to the way of implementation of the magnetogram in WSA model. Excluding the slow CME from the input leads to even larger deviation. The prediction of IP shock 1 drastically improves by introducing of a customized density enhancement factor (dcld) based on coronagraph image observations. This novel approach, is simple and accessible, and could be applied to improve the forecast for fast, undisturbed CMEs. The deviation in the prediction of IP shock 2 comes from its interaction with the low proton temperature environment of the preceding magnetic cloud, giving rise to an expansion of the shock front. Additionally, the properties of the background solar wind plasma have been preconditioned by passage of the previous IP shock. This was confirmed from the kilometric type II radio burst emission following the eruption of the third CME. The propagation profile of this CME implies an almost non-existent deceleration in the interplanetary medium, in contrast to the expected CME deceleration due to interaction with the background plasma. In summary, this study presents clear indications that magnetic interaction must be taken into account to reliably forecast multiple CME events. Preconditioning of previous CMEs must also be considered in more depth, and ultimately requires a realistic, time-dependent model of the ambient solar wind which responds well to propagating shock waves. Models in space physics presents us with the perfect tools for understanding not only the physical processes that the simplified models can predict, but perhaps more importantly, help us begin to understand what the models fail to predict.

Orientador: Paulo César Ciarlini / Banca: Mary Marcondes / Banca: Raimundo Souza Lopes / Resumo: O metabolismo oxidativo e apoptose dos neutrófilos de pacientes humanos nefropatas e sua relação com as toxinas urêmicas tem sido, nos últimos anos, amplamente investigados devido sua importância como elemento imunossupressor. Recentemente surgiram evidências de que a uremia causa disfunção neutrofílica em cães nefropatas, porém não se sabe se o acúmulo de compostos nitrogenados, que também ocorrem nas azotemias não renais, igualmente afeta a função dos neutrófilos. O objetivo do presente estudo foi testar ex vivo a hipótese de que plasmas urêmicos e azotêmicos igualmente afetam o metabolismo oxidativo e a apoptose dos neutrófilos de cães. Para tal, neutrófilos de cães sadios foram isolados e incubados com plasma autólogo, plasma de cão azotêmico e urêmico. A produção de superóxido, com e sem o estimulo com PMA, foi estimada pelo método de redução do nitroazul tetrazólio (NBT) e por citometria de fluxo capilar utilizando-se a sonda hidroetidina (HE). A taxa de neutrófilos viáveis, em apoptose inicial e final, foi quantificada por citometria utilizando-se Anexina V-PE e o índice apoptótico mensurado pelo método morfométrico. A produção de superóxido gerada pelos neutrófilos isolados, em ambos os tratamentos (plasma urêmico e azotêmico) apresentou significante redução (p<0,05). Já a apoptose dos neutrófilos de cães sadios foi acelerada, quando incubados com plasmas urêmico e azotêmico. Pode-se concluir que os componentes presentes nos plasmas urêmicos e azotêmicos alteram ex vivo o metabolismo oxidativo e a apoptose dos neutrófilos, fortalecendo a hipótese de que in vivo ambas condições podem comprometer a imunidade inata de cães / Abstract: The oxidative metabolism and apoptosis of neutrophils from human patients with nephropathy and its relation with uremic toxins has been widely investigated in the last years because of its importance as an immunosuppressive element. Recently evidences suggests that uremia causes neutrophil dysfunction in dogs with renal disease, but it is unclear whether the accumulation of nitrogen compounds, which also occur in non-renal azotemia, can as well affect the role of neutrophils. The objective of this study was to test ex vivo the hypothesis that uremic and azotemic plasma also affects the oxidative metabolism and apoptosis of neutrophils in dogs. To this end, neutrophils from healthy dogs were isolated and incubated with autologous plasma, plasma of azotemic and uremic dog. The production of superoxide, with and without PMA stimulation was estimated by the method of nitroblue tetrazolium reduction (NBT) and by capillary flow cytometry using the hydroethidine probe (HE). The rate of viable, in early and late apoptosis neutrophils was quantified by flow cytometry using Annexin V-PE and theapoptotic index was measured by morphometric method. The production of superoxide generated by isolated neutrophils in both treatments (azotemic and uremic plasma) showed a significant reduction (p <0.05). Neutrophil apoptosis of healthy dogs was accelerated when incubated with uremic and azotemic plasma. In conclusion, the components present in uremic and azotemic plasma change ex vivo the oxidative metabolism and apoptosis of neutrophils, emphasizing the hypothesis that in vivo both conditions can compromise the innate immunity of dogs / Mestre

INTRODUÇÃO. O trauma grave está associado a complexas alterações hemodinâmicas e microcirculatórias. A hipovolemia resultante da perda sanguínea e a inflamação desencadeada pelo trauma tecidual, além da própria isquemia tecidual sistêmica, são os principais fatores que levam a estas alterações. A solução salina hipertônica hiperoncótica (HSD) e a pentoxifilina vem sendo propostas como opções na ressuscitação volêmica do choque hemorrágico, mostrando efeito de modulação da resposta inflamatória e eficácia na restauração dos parâmetros hemodinâmicos. OBJETIVOS. Avaliar a evolução dos mediadores inflamatórios e do burst oxidativo durante 4 horas, após reposição volêmica inicial no tratamento do choque hemorrágico controlado, com três diferentes tipos de solução: Ringer lactato, solução hipertônica hiperoncótica (HSD) e solução hipertônica hiperoncótica associada a pentoxifilina (PTX). MÉTODOS. Anestesiamos e instrumentamos 20 porcos da raça Landrace de 28-32 kg. 5 animais foram randomizados para grupo Sham (apenas anestesiados e monitorizados) e outros 15 submetidos a choque hemorrágico controlado, com pressão arterial média (PAM) mantida em 40 mmHg por 30 minutos. Após o choque 5 animais foram tratados com 32 ml/kg de ringer lactato (grupo RL), 5 animais com 4 ml/kg de HSD (grupo HSD) e 5 animais com 4 ml/kg de HSD + 25 mg/kg de pentoxifilina. Além de medidas hemodinâmicas sistemicas e regionais, procedemos a determinação do burst oxidativo dos neutrófilos circulantes e dos mediadores inflamatórios (TNF alfa, interleucina 1, interleucina 6 e interleucina 10). RESULTADOS. Os animais dos grupos HSD e PTX apresentaram diminuição significativa do burst oxidativo após a reposição volêmica, ao contrário do grupo RL, que apresentou comportamento contrário (p<0,001 para HSD versus RL e PTX versus RL após tratamento). TNF alfa e interleucinas também apresentaram valores estáveis nos grupos tratados com HSD e PTX, enquanto nos animais tratados com RL houve aumento importante destes mediadores. O HSD mostrou-se ineficaz em normalizar algumas variáveis regionais e sitêmicas (p<0,05 após tratamento em T0 para HSD versus Sham e HSD versus PTX), apresentando melhora quando associado a pentoxifilina. CONCLUSÕES. Em modelo experimental de choque hemorrágico controlado, durante observação de 4 horas, a solução salina hipertônica hiperoncótica, utilizada como solução de reposição volêmica em volume de 4ml/kg de peso, demonstrou causar menor ativação de neutrófilos e menor produção de mediadores inflamatórios quando comparada a solução de Ringer lactato. Quando associada a pentoxifilina 25 mg/kg seus efeitos na modulação da resposta inflamatória foram semelhantes. / INTRODUCTION. Major trauma is associated with complex hemodynamic and microcirculatory changes. Volume depletion resulting from blood loss and inflammation triggered by tissue trauma, besides the systemic tissue ischemia, are the main factors leading to these changes. Hypertonic saline hyperoncotic (HSD) and pentoxifylline has been proposed as options in the resuscitation of hemorrhagic shock, showing the effect of modulation of the inflammatory response and efficacy in the restoration of hemodynamic parameters. OBJECTIVES. To evaluate the progression of inflammatory mediators and oxidative burst during 4 hours after initial resuscitation in the treatment of hemorrhagic shock, with three different solutions: Ringer lactate, hypertonic hyperoncotic solution (HSD) and hypertonic hyperoncotic solution associated with pentoxifylline (PTX). METHODS. anesthetized and instrumented 20 Landrace pigs of 28-32 kg 5 animals were randomized to Sham group (only anesthetized and monitored) and 15 submitted to hemorrhagic shock. The mean arterial pressure (MAP) was maintained at 40 mmHg by 30 minutes. After shock 5 animals were treated with 32 ml / kg Ringer\'s lactate (RL group), 5 animals with 4 ml / kg HSD (HSD group) and 5 animals with 4 ml / kg of HSD + 25 mg / kg pentoxifylline. In addition to systemic and regional hemodynamic parameters, we determine the oxidative burst of circulating neutrophils and inflammatory mediators (TNF-alpha, interleukin 1, interleukin 6 and interleukin 10). RESULTS. The animals in the HSD and PTX groups showed a significant decrease in oxidative burst after resuscitation, unlike the RL group, which showed an opposite (p<0.001 for HSD versus RL and RL PTX versus after treatment). TNF alpha and interleukins also showed stable values in the groups treated with HSD and PTX, whereas in animals treated with RL was significant increase of these mediators. The HSD was ineffective in normalizing some regional and systemic hemodynamic variables (p<0.05 after treatment at T0 for HSD versus HSD versus Sham and PTX), which improved when combined with pentoxifylline. CONCLUSIONS. In an experimental model of hemorrhagic shock during the observation of 4 hours, hypertonic saline hyperoncotic used as a solution for volume replacement in volume 4ml/Kg weight, shown to cause less activation of neutrophils and decreased production of inflammatory mediators when compared to Ringer\'s lactate. When coupled with pentoxifylline 25 mg / kg effects on modulation of inflammatory response were similar.

Orientadores: Nelson Luis Saldanha da Fonseca, Marcos Rogério Salvador / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-16T21:55:02Z (GMT). No. of bitstreams: 1 Figueiredo_GustavoBittencourt_D.pdf: 3834927 bytes, checksum: ec5c4028c4e9daddb1935b922f19a729 (MD5) Previous issue date: 2009 / Resumo: A demanda cada vez maior por largura de banda tem levado a implantação de uma Internet de nova geração, com backbones com alta capacidade de transmissão baseados nas tecnologia de multiplexação Wavelength Division Multiplexing (WDM). Para o eficiente transporte do tráfego da Internet, é necessário o uso de um paradigma de transmissão flexível e capaz de se adequar às flutuações do tráfego da rede. Devido a imaturidade da tecnologia de comutação de pacotes ópticos (do inglês Optical Packet Switching - OPS) e das desvantagens da comutação de circuitos ópticos (do inglês Optical Circuit Switching - OCS), a comutação de rajadas ópticas (do inglês Optical Burst Switching - OBS) é uma opção atrativa, dada a sua flexibilidade, maturidade tecnológica e eficiência. Nas redes OBS, os pacotes IP são agrupados em unidades de transmissão maiores, denominadas rajadas, cuja transmissão é precedida por um pacote de controle que sinaliza, entre outras coisas, o momento em que os recursos devem ser reservados. O processo de reserva de recursos é feito em uma via, o que indica que o transmissor não necessita aguardar confirmação por parte do receptor antes de enviar as rajadas. Se não houver recursos disponíveis no momento da transmissão, a rajada é sumariamente descartada. O fato do transmissor não esperar confirmação por parte do receptor para a transmissão das rajadas, implica na necessidade de um dimensionamento adequado da rede, sob pena de alta probabilidade de bloqueio. Nesta tese, são propostos diferentes mecanismos de controle para redes OBS que podem ser usados conjuntamente, a fim de melhorar o desempenho da rede. Esta tese apresenta, inicialmente, um estudo sobre a ocorrência de transformações nas propriedades estatísticas do tráfego submetido à redes OBS, devido ao processo de montagem de rajadas, que ocorre na borda das redes OBS. Verificou-se que a transformação do tráfego está relacionada à escala limitante do tráfego multifractal. Além disso, verificou-se que o tráfego transformado em monofractal demanda menos recursos da rede. Assim, foi proposto um método para identificação automática da escala limitante de fluxos multifractais, além de um conjunto de algoritmos de montagem capazes de induzir as transformações nas propriedades estatísticas do tráfego. Foi proposto, também, na tese, um algoritmo adaptativo para escalonamento de canais em redes OBS que aloca comprimentos de onda com menor chance de reutilização por rajadas futuras. Analisou-se também, nesta tese, o problema de escalonamento em lote de canais em redes OBS. Foram propostos dois algoritmos ótimos: um para o caso quando as requisições que transitam pela rede não possuem diferenciação, e outro para quando a rede exige tratamento diferenciado das requisições. Além disso, foi proposta uma estratégia para a formação dos lotes que pode ser considerada uma extinção do protocolo Just Enough Time - JET. Os mecanismos propostos foram avaliados em comparação com outros existentes na literatura. Os resultados obtidos evidenciam ganhos e a adequabilidade para implementação em redes OBS, a fim de melhorar o desempenho destas redes / Abstract: The growth of the number of Internet users has led to the increase of the bandwidth demand which, consequently, led to the need of adoption of high capacity links in the Internet backbone. Moreover, a flexible switching paradigm is necessary to provide efficient transport of Internet traffic. Due to the limitations of both optical packet switching (OPS) and optical circuit switching (OCS), optical burst switching (OBS) emerged as an attractive switching choice. In OBS networks, IP packets are aggregated into larger transmission units, called bursts. The transmission of a burst follows the transmission of its associated control packet, which carries among other information, the time that bandwidth should be reserved for that burst. In OBS networks, the process of bandwidth reservation is done in one way, which means that the burst is discarded if there is not enough bandwidth for the transmission of the burst at a node when the burst arrives. Therefore, scheduling and burst assembling mechanisms should be conceived to avoid burst loss as well as to support the quality of service of applications running over an OBS network. Initially, a study on traffic transformation at the edge of the network was conducted for the derivation of efficient mechanisms. The study aimed at verifying the changes of traffic descriptors due to the assembly of packets into bursts. It was found that the cutoff time scale of multifractal traffic impacts the traffic transformation. Moreover, it was found that these transformations can lead to smaller bandwidth demands. Based on findings, an automatic method was proposed for the identification of the cutoff time scale of multifractal flows, and a set of burst assembly algorithms for inducing such transformations were introduced. Furthermore, an adaptive algorithm for channel scheduling that allocates wavelengths with small chances of being reused by future requests was proposed. Two optimal algorithms were introduced for the provisioning of differentiated services. In addition, a batch assembly strategy, which can be considered an extension of JET protocol, was created. The proposed mechanisms were evaluated in comparison with other mechanisms in the literature via simulation. Results evince that the mechanisms introduced in this thesis are effective for the improvement of OBS networks performance / Doutorado / Redes de Computadores / Doutor em Ciência da Computação