Joint coding/decoding techniques and diversity techniques for video and HTML transmission over wireless point/multipoint: a survey

I. Introduction The concomitant developments of the Internet, which offers to its users always larger and more evolved contents (from HTML (HyperText Markup Language) files to multimedia applications), and of wireless systems and handhelds integrating them, have progressively convinced a fair share of people of the interest to always be connected. Still, constraints of heterogeneity, reliability, quality and delay over the transmission channels are generally imposed to fulfill the requirements of these new needs and their corresponding economical goals. This implies different theoretical and practical challenges for the digital communications community of the present time. This paper presents a survey of the different techniques existing in the domain of HTML and video stream transmission over erroneous or lossy channels. In particular, the existing techniques on joint source and channel coding and decoding for multimedia or HTML applications are surveyed, as well as the related problems of streaming and downloading files over an IP mobile link. Finally, various diversity techniques that can be considered for such links, from antenna diversity to coding diversity, are presented...L’engouement du grand public pour les applications multimédia sans fil ne cesse de croître depuis le développement d’Internet. Des contraintes d’hétérogénéité de canaux de transmission, de fiabilité, de qualité et de délai sont généralement exigées pour satisfaire les nouveaux besoins applicatifs entraînant ainsi des enjeux économiques importants. À l’heure actuelle, il reste encore un certain nombre de défis pratiques et théoriques lancés par les chercheurs de la communauté des communications numériques. C’est dans ce cadre que s’inscrit le panorama présenté ici. Cet article présente d’une part un état de l’art sur les principales techniques de codage et de décodage conjoint développées dans la littérature pour des applications multimédia de type téléchargement et diffusion de contenu sur lien mobile IP. Sont tout d’abord rappelées des notions fondamentales des communications numériques à savoir le codage de source, le codage de canal ainsi que les théorèmes de Shannon et leurs principales limitations. Les techniques de codage décodage conjoint présentées dans cet article concernent essentiellement celles développées pour des schémas de codage de source faisant intervenir des codes à longueur variable (CLV) notamment les codes d’Huffman, arithmétiques et les codes entropiques universels de type Lempel-Ziv (LZ). Faisant face au problème de la transmission de données (Hypertext Markup Language (HTML) et vidéo) sur un lien sans fil, cet article présente d’autre part un panorama de techniques de diversités plus ou moins complexes en vue d’introduire le nouveau système à multiples antennes d’émission et de réception

EPITOME-2: An open-label study assessing the transition to a new formulation of intravenous epoprostenol in patients with pulmonary arterial hypertension.

Background Continuous infusion of epoprostenol is the treatment of choice in patients with pulmonary arterial hypertension in functional classes III to IV. However, this treatment's limitations include instability at room temperature. A new epoprostenol formulation offers improved storage conditions and patient convenience. Methods The EPITOME-2 trial was an open-label, prospective, multicenter, single-arm, phase IIIb study. Patients with pulmonary arterial hypertension on long-term, stable epoprostenol therapy were transitioned from epoprostenol with glycine and mannitol excipients (Flolan; GlaxoSmithKline, Durham, NC) to epoprostenol with arginine and sucrose excipients (Veletri; Actelion Pharmaceuticals Ltd, Allschwil, Switzerland). Patients were followed up for 3 months, and dose adjustments were recorded. Efficacy measures included the 6-minute walk distance, hemodynamics assessed by right heart catheterization, and New York Heart Association functional class. Safety and tolerability of the transition were also evaluated. Quality of life was assessed using the Treatment Satisfaction Questionnaire for Medication. Results Forty-two patients enrolled in the study, and 1 patient withdrew consent before treatment; thus, 41 patients received treatment and completed the study. Six patients required dose adjustments. There were no clinically relevant changes from baseline to month 3 in any of the efficacy end points. Adverse events were those previously described with intravenous prostacyclin therapy. Treatment Satisfaction Questionnaire for Medication scores showed an improvement from baseline to month 3 in the domain of treatment convenience. Conclusions Transition from epoprostenol with glycine and mannitol excipients to epoprostenol with arginine and sucrose excipients did not affect treatment efficacy, raised no new safety or tolerability concerns, and provided patients with an increased sense of treatment convenience

On the use of antibiotics to control plant pathogenic bacteria: a genetic and genomic perspective

Despite growing attention, antibiotics (such as streptomycin, oxytetracycline or kasugamycin) are still used worldwide for the control of major bacterial plant diseases. This raises concerns on their potential, yet unknown impact on antibiotic and multidrug resistances and the spread of their genetic determinants among bacterial pathogens. Antibiotic resistance genes (ARGs) have been identified in plant pathogenic bacteria (PPB), with streptomycin resistance genes being the most commonly reported. Therefore, the contribution of mobile genetic elements (MGEs) to their spread among PPB, as well as their ability to transfer to other bacteria, need to be further explored. The only well-documented example of ARGs vector in PPB, Tn5393 and its highly similar variants (carrying streptomycin resistance genes), is concerning because of its presence outside PPB, in Salmonella enterica and Klebsiella pneumoniae, two major human pathogens. Although its structure among PPB is still relatively simple, in human- and animal-associated bacteria, Tn5393 has evolved into complex associations with other MGEs and ARGs. This review sheds light on ARGs and MGEs associated with PPB, but also investigates the potential role of antibiotic use in resistance selection in plant-associated bacteria

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

Cork oak vulnerability to fire: the role of bark harvesting, tree characteristics and abiotic factors

Forest ecosystems where periodical tree bark harvesting is a major economic activity may be particularly vulnerable to disturbances such as fire, since debarking usually reduces tree vigour and protection against external agents. In this paper we asked how cork oak Quercus suber trees respond after wildfires and, in particular, how bark harvesting affects post-fire tree survival and resprouting. We gathered data from 22 wildfires (4585 trees) that occurred in three southern European countries (Portugal, Spain and France), covering a wide range of conditions characteristic of Q. suber ecosystems. Post-fire tree responses (tree mortality, stem mortality and crown resprouting) were examined in relation to management and ecological factors using generalized linear mixed-effects models. Results showed that bark thickness and bark harvesting are major factors affecting resistance of Q. suber to fire. Fire vulnerability was higher for trees with thin bark (young or recently debarked individuals) and decreased with increasing bark thickness until cork was 3–4 cm thick. This bark thickness corresponds to the moment when exploited trees are debarked again, meaning that exploited trees are vulnerable to fire during a longer period. Exploited trees were also more likely to be top-killed than unexploited trees, even for the same bark thickness. Additionally, vulnerability to fire increased with burn severity and with tree diameter, and was higher in trees burned in early summer or located in drier south-facing aspects. We provided tree response models useful to help estimating the impact of fire and to support management decisions. The results suggested that an appropriate management of surface fuels and changes in the bark harvesting regime (e.g. debarking coexisting trees in different years or increasing the harvesting cycle) would decrease vulnerability to fire and contribute to the conservation of cork oak ecosystemsinfo:eu-repo/semantics/publishedVersio

Multi-dimensional modeling and simulation of semiconductor nanophotonic devices

Self-consistent modeling and multi-dimensional simulation of semiconductor nanophotonic devices is an important tool in the development of future integrated light sources and quantum devices. Simulations can guide important technological decisions by revealing performance bottlenecks in new device concepts, contribute to their understanding and help to theoretically explore their optimization potential. The efficient implementation of multi-dimensional numerical simulations for computer-aided design tasks requires sophisticated numerical methods and modeling techniques. We review recent advances in device-scale modeling of quantum dot based single-photon sources and laser diodes by self-consistently coupling the optical Maxwell equations with semiclassical carrier transport models using semi-classical and fully quantum mechanical descriptions of the optically active region, respectively. For the simulation of realistic devices with complex, multi-dimensional geometries, we have developed a novel hp-adaptive finite element approach for the optical Maxwell equations, using mixed meshes adapted to the multi-scale properties of the photonic structures. For electrically driven devices, we introduced novel discretization and parameter-embedding techniques to solve the drift-diffusion system for strongly degenerate semiconductors at cryogenic temperature. Our methodical advances are demonstrated on various applications, including vertical-cavity surface-emitting lasers, grating couplers and single-photon sources

The microbiome and rheumatoid arthritis

Rheumatoid Arthritis (RA) is a severe, chronic autoimmune disease that affects 1% of the world's population. Familial risk contributes 50% of the risk of seropositive RA, with strongest risks seen in first-degree relatives. Smoking increases the risk of developing anti-citrullinated peptide antibody (ACPA) RA, particularly in individuals with high-risk RA-susceptibility alleles. Other contributory environmental risks including particulate exposure, periodontal disease, bronchiectasis, diet, obesity and the oral contraceptive impact respiratory, oral, intestinal and genital tract mucosal sites. Furthermore, the first signs of autoimmunity may appear at mucosal sites e.g. sputum ACPA-IgA and IgG. While oral and faecal dysbiosis are well described, there is no consistent single bacterial species that appears to drive RA. Animal and human data suggest a model in which multiple environmental influences impact mucosal immune function through the host genetics through enhanced mucosal permeability and the traffic of pro-inflammatory PAMPs and the amplification of autoimmune responses. In some cases, autoimmunity may be driven by cross-reactivity, or mimicry, to pathogen-specific antigens, particularly where the host immune system fails to support their rapid control and elimination

Regulatory T cells induced by single-peptide liposome immunotherapy suppress islet-Specific T cell responses to multiple antigens and protect from autoimmune diabetes

Ag-specific tolerizing immunotherapy is considered the optimal strategy to control type 1 diabetes, a childhood disease involving autoimmunity toward multiple islet antigenic peptides. To understand whether tolerizing immunotherapy with a single peptide could control diabetes driven by multiple Ags, we coencapsulated the high-affinity CD4 mimotope (BDC2.5) of islet autoantigen chromogranin A (ChgA) with or without calcitriol (1α,25-dihydroxyvitamin D3) into liposomes. After liposome administration, we followed the endogenous ChgA-specific immune response with specific tetramers. Liposome administration s.c., but not i.v., induced ChgA-specific Foxp3 and Foxp3 PD1 CD73 ICOS IL-10 peripheral regulatory T cells in prediabetic mice, and liposome administration at the onset of hyperglycemia significantly delayed diabetes progression. After BDC2.5/calcitriol liposome administration, adoptive transfer of CD4 T cells suppressed the development of diabetes in NOD severe combined immunodeficiency mice receiving diabetogenic splenocytes. After BDC2.5/calcitriol liposome treatment and expansion of ChgA-specific peripheral regulatory T cells. IFN-γ production and expansion of islet-specific glucose-6-phosphatase catalytic subunit-related protein-specific CD8 T cells were also suppressed in pancreatic draining lymph node, demonstrating bystander tolerance at the site of Ag presentation. Thus, liposomes encapsulating the single CD4 peptide, BDC2.5, and calcitriol induce ChgA-specific CD4 T cells that regulate CD4 and CD8 self-antigen specificities and autoimmune diabetes in NOD mice

Adoptive Transfer of T Lymphocytes Sensitized against the Prion Protein Attenuates Prion Invasion in Scrapie-Infected Mice

There is to date no effective way of preventing or curing neurodegenerative diseases such as Alzheimer disease or transmissible spongiform encephalopathies. The idea of treating those conditions by immunological approaches has progressively emerged over the last ten years. Encouraging results have been reported in Alzheimer disease and in peripheral forms of mouse prion diseases following passive injection of Abs or active immunization against the peptides or proteins presumably at the origin of those disorders. Still, major difficulties persist due to some characteristics of those conditions such as slow evolution, brain location, uncertainties regarding precise pathogenic pathways, and, above all, the fact that the target Ag is self, meaning that it is poorly immunogenic and potentially harmful if tolerance was transgressed. To analyze some of those difficulties, we are developing adoptive cell transfer approaches. In this study, lymphocytes sensitized against the prion protein in nontolerant Prnp mice were transferred into histocompatible wild-type recipients which were partly or totally devoid of their own lymphocytes. Under such conditions, we found that the engrafted T lymphocytes resisted peripheral tolerance, remained reactive for several months against epitopes of the prion protein, and significantly attenuated the progression of prions in secondary lymphoid organs with subsequent delay in the evolution of the neurological disease. Interestingly, those protective T lymphocytes secreted lymphokines and migrated more readily into the host CNS but did not appear to be engaged in cooperation with host B cells for Ab production