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Les outils de bio-indication basés sur les réponses des peuplements piscicoles aux pressions anthropiques dans les cours d'eau ont fait l'objet de développements récents dans un cadre national et européen. La méthode initiale développée aux États-Unis (indice d'intégrité biotique) a été améliorée afin de prendre en compte la variabilité environnementale et d'évaluer la réponse biologique en terme d'écart par rapport à une situation de référence explicite. / Recently, new methods for the assessment of rivers based on the response of fish assemblage to human alterations have been developed at the national and European scales. The original approach developed in US (Index of Biotic Integrity) has been improved in order to consider the natural environmental variability and to quantify the biological response as a deviation from an explicit reference condition.

Dendritic cells (DC) are professional antigen-presenting cells (APC) that play an essential role in the induction of immune responses. DCs develop from CD34+ hematopoietic stem cells in bone marrow and their role is uptake, processing and presentation of antigens to T cells. DCs can be divided into two distinct subset of cells, myeloid a plasmacytoid DCs. Myeloid DCs (mDC) develop from hematopoietic cells in the presence of GM-CSF and TNF-α or from monocytes in the culture with GM-CSF and IL-4, then with CD40L they mature and produce a large number of IL-12, which is important in driving CD4+ T cell to type Th1. The development of pDC is CD40L and IL-3 dependent and Flt3-L supports this process as well. The essential role of pDC is that they secrete a large amounts of type I IFN in the responses to viruses and so they maintain the antiviral stage. To recognize the viruses pDC express Toll-like receptors 7/9. DCs have on the surface also other groups of receptors, e.g. C-type lectin-like receptors, RIG-I-like receptors and NOD-like receptors. They play the role in the various diseases, mostly autoimmune diseases, in which the immune system recognizes self tissues and activates against them the immune response. Dendritic cells function is that they are competent to activate T cells, in the most cases...

International audience; Celiac disease is characterized by the secretion of IgA-class autoantibodies that target tissue transglutaminase (tTG). It is now recognized that anti-tTG antibodies are functional and not mere bystanders in the pathogenesis of celiac disease. Here we report that interaction between anti-tTG antibodies and extracellular membrane-bound tTG inhibits peptide 31-43 (but not peptide 57-68) uptake by cells, thereby impairing the ability of p31-43 to drive Caco-2 cells into S-phase. This effect did not involve tTG catalytic activity. Because anti-tTG antibodies interfered with epidermal growth factor endocytosis, we assume that they exert their effect by reducing peptide 31-43 endocytosis. Our results suggest that cell-surface tTG plays a hitherto unknown role in the regulation of gliadin peptide uptake and endocytosis.

The Future Internet is not envisaged to be simply a faster way to go online. What is expected to fundamentally change the way that people use the Internet is the ability to produce, and seamlessly deliver and share their own multimedia content. In this paper, we introduce and analyse innovative architecture components to offer media scalable content delivery, increasing the robustness, enriching the PQoS and protecting the content from unauthorized access over heterogeneous physical architecture and P2P logical overlay network topologies. Technology pillars in which the system is based are described: i.e. Multi-layered/Multi-viewed content coding, Multi-source/multi-network streaming & adaptation, content protection and lightweight asset management.

Pollen-assoziierte Lipidmediatoren (PALMs) hemmen die LPS-induzierte Zytokinproduktion von Monozyten-abgeleiteten dendritischen Zellen. Da es sich bei diesen Zellen allerdings um in vitro generierte Zellen handelt, sollte im Rahmen dieser Arbeit der Einfluss von PALMs auf die verschiedenen dendritschen Subpopulationen aus humanem peripherem Blut untersucht werden. Dazu wurden slanDCs, myleoide- und plasmazytoide dendritische Zellen isoliert. Dabei konnte erstmals gezeigt werden, dass wässrige Pollenextrakte von Betula alba (Bet.-APE) die reifungsinduzierte Zytokinproduktion sowie die Aufregulation von Maturationsmarkern bei allen DC-Subpopulationen hemmten. Weiterhin wurde herausgefunden, dass ein nicht-proteinerger Faktor aus wässrigen Pollenextrakten von Betula Alba mit einem Molekulargewicht

The IP protocol is based on a model called best effort, where all packets are treated the same way, without any discrimination or explicit delivery guarantees. It was develop to deal with application without QoS (Quality of service) requirements such as e-mail and FTP (File Transfer Protocol). However, more and more communication systems are supporting different kinds of real-time transmission, such as voice over IP (VoIP), interactive TV and videoconferencing. Of course, the best effort model is not suitable to cope with these new high quality real-time communication systems, so a new model needs to be develop. The challenges of transmitting high quality streaming over best-effort networks include delay, packet loss, varying bandwidth and have led to several different approaches to efficiently support multimedia streaming applications. In this context, path diversity and MDC (Multiple Description Coding) have emerged as promising techniques for robust transmission of multimedia traffic over lossy packet networks as the Internet. Path diversity is a technique that exploits different paths available between two specific hosts in the internet. MDC is a technique where the video stream is divided into multiple sub-streams (called descriptions), such that the quality of the received video increases with the number of descriptions received. In this paper, a set of admission control disciplines was developed in a DiffServ environment which take into consideration path diversity, in which one flow can be accept using more than one single path. Our main goal is to provide the fundamental understanding of the benefits of using methodologies like MDC and path diversity together to deliver continuous media stream over the internet. The parameters for admission are the bandwidth, the request start and stop time. Our results show that the use of path diversity exhibits better QoS characteristics when compared with the traditional methodology, where the best path is always used. The experiments indicate that the approach used was able to use the network resources efficiently and to achieve a better level of request accepted as well as decreases the packet loss rate. O protocolo IP é baseado em um modelo chamado de melhor esforço, no qual todos os pacotes são tratados de maneira igual, sem nenhum tipo de diferenciação ou mecanismo explícito de entrega. Este modelo foi desenvolvido para lidar com aplicações que não possuem nenhum requisito de QoS (Quality of service) como aplicações de correio eletrônico e transferência de arquivos. Contudo, mais e mais sistemas de comunicações suportam diferentes tipos de transmissões em tempo real, como voz sobre IP (VOIP), TV com interatividade e videoconferência. Obviamente, o modelo de maior esforço não é adequado com esses novos tipos de sistemas de comunicação em tempo real. Logo, novos modelos precisam ser desenvolvidos. Os desafios de transmitir fluxos de dados de alta qualidade sobre redes baseadas no modelo de melhor esforço incluem retardo de pacotes, perda de pacotes, variações de atraso fim-a-fim e tem motivado o desenvolvimento de diferentes soluções com o objetivo de suportar aplicações multimídia de forma eficiente. Neste contexto, o método de diversidade de caminhos (path diversity e MDC (Multiple Description Coding) surgiram como técnicas transmissoras para a transmissão robusta de tráfego multimídia de redes com a possibilidade de perda de pacotes como é o caso da internet. O método de diversidade de caminhos é uma técnica que explora diferentes caminhos diferentes disponíveis entre os hosts específicos da internet. MDC é uma técnica na qual um fluxo de vídeos é dividido em múltiplos subfluxos (chamados de descrições), de tal forma que a qualidade do vídeo recebido aumenta com o numero de descrições recebidas. Neste trabalho, foi desenvolvido um numero de disciplinas de controle de admissão para uma rede DiffServ que leva em consideração a utilização o método de diversidade de caminhos (um fluxo pode ser admitido utilizando-se mais de um caminho). Nosso principal objetivo foi prover um entendimento dos benefícios de usar as técnicas de MDC e de diversidade de caminhos combinadas para se enviar fluxos de vídeos sobre a internet. Os parâmetro para a admissão de um fluxo são a banda passante necessária, o tempo de inicio e o tempo de fim do fluxo. Os resultados apresentados neste trabalho mostram que a utilização do método de diversidades de caminhos exibe uma melhora nas características de QoS se comparando com o método tradicional, no qual o melhor caminho é sempre utilizado. Os experimentos indicam que a abordagem utilizada foi capaz de utilizar os recursos da rede de uma forma mais eficiente e atingir um melhor nível de requisições aceitas, assim como uma menor taxa de perda de pacotes.

Undeveloped immune system in infants is considered to be responsible for the severe RSV infections in infants (i.e. bronchiolitis) since virus can skew antiviral type-1 to less effective type-2 immune reaction. Accumulation of lymphocytes in the lungs, during RSV infection, is mediated by type-1 chemokines (IP-10, MIG and fractalkine) through binding of CXCR3 and CX3CR1. Opposing type-2 chemokines (TARC and MDC) are responsible for migration of CCR4-positive lymphocytes involved in allergic immune responses. We postulate that RSV- infected infants produce elevated type-2 chemokines and compromise antiviral response. PBMC from RSV-, adenovirus/influenza-infected infants and RSV-infants collected 4-6 weeks after first sampling were simultaneously stained with antibodies for chemokine receptors (CCR4, CXCR3, CX3CR1) and lymphocyte subpopulation markers. Serum chemokines (TARC, MDC, IP-10, MIG, fractalkline) were determined by ELISA. CD4+ T- lymphocytes bearing CCR4 and CXCR3 were depleted from peripheral blood in RSV-infected infants, compared to infants with adenovirus/influenza infections. Interestingly, more B-lymphocytes of RSV-infected infants express CCR4, CXCR3 and CX3CR1 compared to adenovirus/influenza-infected infants. In convalescent phase, percentages of CCR4+ and CXCR3+ CD4+ T-lymphocytes increased while percentages of CCR4+, CXCR3+ and CX3CR1+ B- cells decreased. In acute phase of RSV infections, the predominant chemokines were TARC, MDC and IP- 10. In convalescent phase serum levels of TARC, MDC and IP-10 decreased. In conclusion, we observed a mixed type of chemokine production and chemokine receptors level during acute phase of RSV infection. Higher TARC levels and CCR4 positive lymphocytes could contribute to type-2 cytokine synthesis and confront effective type-1 cytokine-driven antiviral immune response.

Objectives: Respiratory syncytial virus (RSV) causes lower respiratory tract infection (bronchiolitis) in newborns/infants directed by the mononuclear cell accumulation to the lungs. Undeveloped immune system in infants is considered to be cause of severe form of illness, although RSV itself has potential to skew the effective antiviral type-1 immune reaction to less effective type-2. Type-1 related chemokines (IP-10, MIG and fractalkine) predominantly induce migration of CXCR3 and CX3CR1 positive, type-1 profiled lymphocytes that are necessary to control viral infections. Opposing type-2 related chemokines (TARC and MDC) are responsible for migration of CCR4-positive type-2 lymphocytes involved in allergic immune responses. We postulate that RSV-infected infants produce elevated type-2 vs. type-1 cytokine-associated chemokines that compromise effective antiviral response. Methods: PMBC were isolated from blood samples of RSV-infected hospitalized infants (N=14), 6 infants infected with influenza and adenovirus, 9 age-matched healthy controls and from blood samples of 10 infants collected 4-6 weeks after first sampling. PBMC were simultaneously stained with mAb´s for chemokine receptors (CCR4, CXCR3, CX3CR1), and lymphocyte subpopulation markers. Multiparametric analyis was performed on LSRII flow cytometer. Frozen serum samples were used to measure soluble chemokine (TARC, MDC, IP-10, MIG, fractalkline, I-TAC, TSLP) concentration. Results: In acute phase of RSV- and other viruse-infected infants, the predominant chemokine in serum is IP-10. TARC is overproduced in RSV while fractalkine and MIG are predominant in acute influenza and adenovirus infections. Interestingly, 4-6 weeks after first sampling, serum levels of TARC, MDC, IP-10 and MIG increased even more in RSV-infected infants. In acute phase, higher percentages of B-lymphocytes and CTL's express CCR4, CXCR3 and CX3CR1 compared to healthy and other-viruses infected infants. In convalescent phase, percentages of CCR4-positive B-lymphocytes and CTL's didn't change while there was increase of CXCR3 expression. Conclusion: Mixed type of cytokine production during acute phase of RSV infection could be observed on both the chemokine and chemokine receptors level. Higher TARC concentration imposes type-2 immune reaction at inflammatory site that could lead to more pronounced RSV-driven inflammatory process with severe clinical findings since CCR4-positive lymphocytes contribute to type-2 cytokine synthesis and confront effective type-1 cytokine-driven antiviral immune reaction.

Peer-to-peer (P2P) streaming systems grow in numbers and potential and several commercial products are already competing. Internet home users - through the diffusion of xDSL connections - represent the potential market of IPTV channels that Content Generators may distribute at reduced costs. This work describes the state of the art of P2P streaming clients and poses some questions about the end-user perspective in heterogeneous networks. To this aim, a representative set of experiments has been performed on a popular P2P system. The client offers live streaming content from some European broadcasters, start-up delay is a few seconds and the user satisfaction rank is good. The trend moves toward solutions that try to optimize the whole network stack, pursuing flexibility in terms of user needs and system requirements. This work is aimed at focusing on the key-drives in the design of P2P streaming clients. © 2009 The authors and IOS Press. All rights reserved.

International audience; nce escaped from the quiescence niche, precursor cells interact with stromal components that support their survival, proliferation, and differentiation. We examined interplays between human myogenic precursor cells (mpc) and monocyte/macrophages (MP), the main stromal cell type observed at site of muscle regeneration. mpc selectively and specifically attracted monocytes in vitro after their release from quiescence, chemotaxis declining with differentiation. A DNA macroarray-based strategy identified five chemotactic factors accounting for 77% of chemotaxis: MP-derived chemokine, monocyte chemoattractant protein-1, fractalkine, VEGF, and the urokinase O system. MP showed lower constitutive chemotactic activity than mpc, but attracted monocytes much strongly than mpc upon cross-stimulation, suggesting mpc-induced and predominantly MP-supported amplification of monocyte recruitment. Determination of [ 3 H]thymidine incorporation, oligosomal DNA levels and annexin-V binding showed that MP stimulate mpc proliferation by soluble factors, and rescue mpc from apoptosis by direct contacts. We conclude that once activated, mpc, which are located close by capillaries, initiate monocyte recruitment and interplay with MP to amplify chemotaxis and enhance muscle growth.

One focus of the HADES experiment (High Acceptance Di-Electron Spectrometer; Gesellschaft für Schwerionenforschung (GSI) mbH (Germany)) is the investigation of the decay of light vector mesons inside a dense medium into lepton pairs. These decays provide a conceptually ideal tool to study the invariant mass of the vector meson in-medium, since the lepton pairs of these meson decays leave the reaction without further strong interaction. Thus, no final state interaction affects the measurement. Unfortunately, the branching ratios of vector mesons into lepton pairs are very small (ca. 0.00001). This calls for a high rate, high acceptance experiment. In addition, a sophisticated real time trigger system is used in HADES to enrich the interesting events in the recorded data. The focus of this thesis is the development of a next generation real time trigger method to improve the enrichment of lepton events in the HADES trigger. In addition, a flexible hardware platform (GE-MN (Gigabit-Ethernet-Multi-Node)) was developed to implement and test the trigger method. The GE-MN features two Gigabit-Ethernet interfaces for data transport, a VMEbus for slow control and configuration, and a TigerSHARC DSP for data processing. It provides the experience to discuss the challenges and benefits of using a commercial standard network technology based system in an experiment. The developed and tested trigger method correlates the ring information of the HADES RICH (RICH detector: Ring Imaging Cherenkov detector) with the fired wires (cells) of the HADES MDC detector (MDC: Mini Drift Chambers; drift chamber based detector system for the tracking of charged particles). This correlation method operates by calculating for each event the cells which should have seen the signal of a traversing lepton, and compares these calculated cells to all the cells that did see a signal. The cells which should have fired are calculated from the polar and azimuthal angle information of the RICH rings by assuming a straight line in space, which is starting at the target and extending into a direction given by the ring angles. The line extends through the inner MDC chambers and the traversed cells are those that should have been hit. To compensate different sources for inaccuracies not the exact cell numbers are required, but instead the cells in a matching window are investigated, and only a fraction of the MDC layers that should be hit are required to have seen a hit. It is demonstrated that the use of the correlation method can enhance the number of events which contain leptons by an experiment dependent factor. The possible enhancements of different reactions are approx. 30 for p+p, approx. 50 for C+C and approx. 5.5 for Ar+KCl. The efficiency at these enhancements is above 80%, and it is constant in relation to the parameters polar angle, azimuthal angle and momentum. It is demonstrated how to obtain the correlation parameters from the online available raw data only. The performance of the correlation method in terms of the events analyzed per second has been studied with the GE-MN. The performance depends on the input data and ranges from 6600 events/s for p+p data to 1400 events/s for Ar+KCl data for a single GE-MN system. Eines der Hauptaufgabengebiete des HADES Experiments (High Acceptance Di-Electron Spectrometer; Gesellschaft für Schwerionenforschung (GSI) mbH (Germany)) ist die Erforschung des Zerfalls leichter Vektormesonen in Leptonenpaare innerhalb eines dichten Mediums. Diese Zerfälle sind ein konzeptionell ideales Werkzeug zur Erforschung der invarianten Masse von Vektormesonen in einem Medium, da diese das Medium in dem sie zerfallen ohne weitere starke Wechselwirkung verlassen. Daher wird die Messung nicht von Wechselwirkungen im Endzustand beeinflusst. Unglücklicherweise sind die Verzweigungsverhältnisse von Vektormesonen nach Leptonenpaaren sehr klein (ca. 0,00001), was es nötig macht Experimente mit hohen Reaktionsraten und hoher Akzeptanz durchzuführen. Zusätzlich verfügt das HADES Experiment über ein leistungsfähiges Trigger-System, um die physikalisch relevanten Ereignisse in den aufgenommenen Daten anzureichern. Das Augenmerk dieser Arbeit liegt in der Entwicklung der nächsten Generation eines in Echtzeit arbeitenden Trigger-Verfahrens für das HADES Experiment zur signifikanten Verbesserung der Anreicherung von Leptonen. Des weiteren wurde eine Hardwareplatform (das GE-MN (Gigabit-Ethernet-Multi-Node)) zur Entwicklung und zur Erprobung des Trigger-Verfahrens entwickelt. Das GE-MN System besitzt zwei Gigabit-Ethernet Schnittstellen für den Transport von Daten, eine VMEbus Schnittstelle zur Konfiguration und Überwachung sowie einen TigerSHARC DSP zur Datenverarbeitung. Es ermöglicht die Diskussion der Herausforderungen und Vorteile beim Einsatz eines solchen, auf Standard-Netzwerktechnologie aufbauenden, Systems in physikalischen Experimenten. Die vorgestellte Trigger-Methode korreliert die Ring-Informationen des HADES RICH Detektors (RICH Detektor: Ring Imaging Cherenkov Detektor) mit den angesprochenen Drahtkammern des HADES MDC Detektors (MDC: Mini Drift Chambers; Driftkammer basiertes Detektorsystem zur Spurverfolgung geladener Teilchen). Sie berechnet die Drahtkammern, die durch das Signal eines hindurch fliegenden Leptons hätten ansprechen sollen und vergleicht diese mit den tatsächlich angesprochenen Drahtkammern. Die angesprochenen Drähte werden ausgehend von den Polar- und Azimutwinkelinformationen berechnet, indem ausgehend vom Target eine Gerade mit den Winkeln des Ringes in den Raum gelegt wird. Diese Gerade führt durch die inneren Drahtkammern. Die geschnittenen Drahtkammern sind diejenigen, die einen Treffer registrieren sollten. Zur Kompensation verschiedener Ungenauigkeiten werden nicht Treffer der berechneten Driftzellen gefordert, sondern lediglich Treffer in einem Korrelationsfenster verlangt, und nur ein Bruchteil der berechneten Drahtkammerlagen muss einen Treffer registriert haben. Im Weiteren wird gezeigt, daß die Verwendung dieser Korrelationsmethode die Anzahl an Ereignissen, die Leptonen enthalten, um einen von dem Experiment abhängigen Faktor anreichern kann. Die möglichen Anreicherungsfaktoren für verschiedene Reaktionen sind ca. 30 für p+p, ca. 50 für C+C und ca. 5,5 für Ar+KCl. Hierbei liegt die Effizienz immer über 80% und zeigt keine Abhängigkeit von den Größen Polarwinkel, Azimuthalwinkel und Leptonenimpuls. Es wird gezeigt wie die Einstellungen zum Betrieb der Trigger-Methode vollständig aus den in Echtzeit verfügbaren Rohdaten gewonnen werden kann. Die Geschwindigkeit der Methode in analysierten Ereignissen pro Sekunde wird mit dem GE-MN untersucht. Sie hängt ab von den Eingangsdaten und reicht von 6600 Ereignisse/s für p+p Daten bis zu 1400 Ereignisse/s für Ar+KCl Daten unter Verwendung lediglich eines GE-MN Systems.

Background: The usefulness of thin-slice mult-detector computed tomography (MDCT) has been highly expected to assess the lumens of coronary artery stents. We evaluated the usefulness of 16-slice MDCT to assess the in-stent lumen after coronary artery stenting. Methods: In 42 consecutive patients after coronary artery stenting, retrospective ECG-gated CT-angiography using 16-slice MDCT (0.5sec rotation time, 16×0.625-mm detector collimation) was performed. The qualitative assessability of the lumens of 61 coronary stents (14 different types) by MDCT and the reasons for nonassessability were investigated. Furthermore, the evaluation of in-stent restenosis in 21 assessable stents of 16 patients, including quantitative density analysis by MDCT, was performed and the results were compared with those of conventional coronary angiography (CAG). Results: Of 61 stents, 42 (68.9%) were assessable. The assessability of diameter 3.5-mm stents made of stainless steel or cobalt was high (88.6%, 31/35), that of 3.0-mm stents was low (57.9%, 11/19) and all 2.5-mm stents were non-assessable due to partial volume effects and metal artifacts of stents. The lumens of stents made of tantalum were totally obscured and the metal artifacts of Bestent2 (gold markers) and S670 were severer than others. All non-assessable stents due to banding artifact and calcification were implanted in segment #1-3 and #6, respectively. In comparison to CAG, MDCT correctly detected the 5 in-stent restenoses and identified absence of restenosis in the remaining 16 stents. The quantitative density analysis of in-stent restenoses was influenced strongly by the stent strut. Conclusion: Despite some limitations, 16-slice MSCT is sufficiently useful for assessment of various coronary stents in patients and can detect in-stent restenoses of assessable stents with high accuracy in comparison to CAG.

The Internet has rapidly evolved from being a scientific experiment to a commercial network connecting millions of hosts that carries traffic generated by a large amount of applications with diverse requirements. Its architecture was however designed to enable efficient point-to-point delivery of bulk data, and can not provide statistical guarantees on the timely delivery of delay sensitive data such as streaming and real-time multimedia. Thus, applications that require low loss probabilities in today's Internet have to use some end-to-end error recovery mechanism. For delay sensitive applications the introduced latency by the applied schemes has to be low as well. Traffic control functions such as delay limited shaping and forward error correction (FEC), and multiple description coding (MDC) have been proposed for variable bitrate video. Their major drawback is, however, that it is difficult to predict their efficiency, as it depends on many factors like the characteristics of the stream itself, the characteristics of the traffic in the network and the network parameters. Consequently, it is difficult to decide which control mechanisms to employ, how to combine them and to choose the right parameters (e.g. block length, code rate) for optimal performance. In this thesis we present results on the efficiency of traffic control functions and MDC for video transmission based on mathematical models and simulations. We investigate the efficiency of delay limited traffic shaping and the trade-offs in the joint use of traffic shaping and forward error correction. We identify the packet size distribution of the traffic in the network as an additional factor that may influence the efficiency of FEC, and present a thorough analysis of its possible effects. We present an analytical comparison of MDC versus media-dependent FEC and media-independent FEC, and based on the results we conclude that MDC is a promising error control solution for multimedia communications with very strict delay bounds in an environment with bursty losses. We combine the analytical results with traces from measurements performed on the Internet to evaluate how efficient these error control schemes are under real loss patterns. We compare the efficiency of MDC and media-dependent FEC in the presence of channel estimation errors; we propose a new rate allocation method, which is robust to mis-estimations of the channel state and which improves error resilience on non-stationary channels. Finally we present an analytical model of the performance of an end-point-based multimedia streaming architecture based on multiple distribution trees and forward error correction, and analyze the behavior of the architecture for a large number of nodes. QC 20101115

The role of p53, the original “guardian of the genome”, in skin has remained elusive. We have explored p53 function in human epidermal cells and demonstrated the importance of a mitosis-differentiation checkpoint to suppress potentially precancerous cells. This model places epidermal endoreplication as an antioncogenic mechanism in the face of irreparable genetic alterations.