1,794 research outputs found

    Investigation of the AODV and the SDWCA QoS handling at different utilisation levels in adaptive clustering environments

    Get PDF
    A simulation study using NS2 simulator using two main routing protocols with specific design parameters has been carried out to investigate the QoS main parameters such as throughput, delay, Jitter, Control Overhead, Number of packets, number of packets dropped and the rating overheads. The traffic is made of CBR slow video traffic. From the result it is noted that the SDWCA routing protocol outperforms the AODV routing protocols in the throughput, the delay and the jitter issues at different loading levels

    Metagenomic Hi-C of a Healthy Human Fecal Microbiome Transplant Donor.

    Full text link
    We report the availability of a high-quality metagenomic Hi-C data set generated from a fecal sample taken from a healthy fecal microbiome transplant donor subject. We report on basic features of the data to evaluate their quality

    Bridging the Gap: the need for a systems thinking approach in understanding and addressing energy and environmental performance in buildings

    Get PDF
    Innovations in materials, construction techniques and technologies in building construction and refurbishment aim to reduce carbon emissions and produce low-energy buildings. However, in-use performance consistently misses design specifications, particularly those of operational energy use and indoor environmental quality. This performance gap risks reducing design, technology, sustainability, economic, health and well-being benefits. In this paper, we compare settings of the Chinese and the UK buildings sectors and relate their historical context, design, construction and operation issues impacting energy performance, indoor environmental quality, occupant health and well-being. We identify a series of key, common factors of ‘total’ building performance across these two settings: the application of building regulations, the balance between building cost and performance, skills, construction and operation. The dynamic and complex interactions of these factors are currently poorly understood and lead to building performance gaps. We contend that a systems approach in the development of suitable building assessment methods, technologies and tools could enable the formulation and implementation of more effective policies, regulations and practices. The paper illustrates the application of the approach to the UK and Chinese settings. A full application of a systems approach may help to provide a more dynamic understanding of how factor interactions impact the ‘total’ building performance gaps and help address its multiple causes

    Canalization of the evolutionary trajectory of the human influenza virus

    Get PDF
    Since its emergence in 1968, influenza A (H3N2) has evolved extensively in genotype and antigenic phenotype. Antigenic evolution occurs in the context of a two-dimensional 'antigenic map', while genetic evolution shows a characteristic ladder-like genealogical tree. Here, we use a large-scale individual-based model to show that evolution in a Euclidean antigenic space provides a remarkable correspondence between model behavior and the epidemiological, antigenic, genealogical and geographic patterns observed in influenza virus. We find that evolution away from existing human immunity results in rapid population turnover in the influenza virus and that this population turnover occurs primarily along a single antigenic axis. Thus, selective dynamics induce a canalized evolutionary trajectory, in which the evolutionary fate of the influenza population is surprisingly repeatable and hence, in theory, predictable.Comment: 29 pages, 5 figures, 10 supporting figure

    VEZF1 elements mediate protection from DNA methylation

    Get PDF
    There is growing consensus that genome organization and long-range gene regulation involves partitioning of the genome into domains of distinct epigenetic chromatin states. Chromatin insulator or barrier elements are key components of these processes as they can establish boundaries between chromatin states. The ability of elements such as the paradigm β-globin HS4 insulator to block the range of enhancers or the spread of repressive histone modifications is well established. Here we have addressed the hypothesis that a barrier element in vertebrates should be capable of defending a gene from silencing by DNA methylation. Using an established stable reporter gene system, we find that HS4 acts specifically to protect a gene promoter from de novo DNA methylation. Notably, protection from methylation can occur in the absence of histone acetylation or transcription. There is a division of labor at HS4; the sequences that mediate protection from methylation are separable from those that mediate CTCF-dependent enhancer blocking and USF-dependent histone modification recruitment. The zinc finger protein VEZF1 was purified as the factor that specifically interacts with the methylation protection elements. VEZF1 is a candidate CpG island protection factor as the G-rich sequences bound by VEZF1 are frequently found at CpG island promoters. Indeed, we show that VEZF1 elements are sufficient to mediate demethylation and protection of the APRT CpG island promoter from DNA methylation. We propose that many barrier elements in vertebrates will prevent DNA methylation in addition to blocking the propagation of repressive histone modifications, as either process is sufficient to direct the establishment of an epigenetically stable silent chromatin stat

    Rupture by damage accumulation in rocks

    Get PDF
    The deformation of rocks is associated with microcracks nucleation and propagation, i.e. damage. The accumulation of damage and its spatial localization lead to the creation of a macroscale discontinuity, so-called "fault" in geological terms, and to the failure of the material, i.e. a dramatic decrease of the mechanical properties as strength and modulus. The damage process can be studied both statically by direct observation of thin sections and dynamically by recording acoustic waves emitted by crack propagation (acoustic emission). Here we first review such observations concerning geological objects over scales ranging from the laboratory sample scale (dm) to seismically active faults (km), including cliffs and rock masses (Dm, hm). These observations reveal complex patterns in both space (fractal properties of damage structures as roughness and gouge), time (clustering, particular trends when the failure approaches) and energy domains (power-law distributions of energy release bursts). We use a numerical model based on progressive damage within an elastic interaction framework which allows us to simulate these observations. This study shows that the failure in rocks can be the result of damage accumulation

    Bringing Open Data to Whole Slide Imaging

    Get PDF
    Supplementary information associated with Besson et al. (2019) ECDP 2019 Faced with the need to support a growing number of whole slide imaging (WSI) file formats, our team has extended a long-standing community file format (OME-TIFF) for use in digital pathology. The format makes use of the core TIFF specification to store multi-resolution (or "pyramidal") representations of a single slide in a flexible, performant manner. Here we describe the structure of this format, its performance characteristics, as well as an open-source library support for reading and writing pyramidal OME-TIFFs

    A compendium and functional characterization of mammalian genes involved in adaptation to Arctic or Antarctic environments

    Get PDF
    Many mammals are well adapted to surviving in extremely cold environments. These species have likely accumulated genetic changes that help them efficiently cope with low temperatures. It is not known whether the same genes related to cold adaptation in one species would be under selection in another species. The aims of this study therefore were: to create a compendium of mammalian genes related to adaptations to a low temperature environment; to identify genes related to cold tolerance that have been subjected to independent positive selection in several species; to determine promising candidate genes/pathways/organs for further empirical research on cold adaptation in mammals

    The Amino-Terminus of Nitric Oxide Sensitive Guanylyl Cyclase α1 Does Not Affect Dimerization but Influences Subcellular Localization

    Get PDF
    BACKGROUND: Nitric oxide sensitive guanylyl cyclase (NOsGC) is a heterodimeric enzyme formed by an α- and a β₁-subunit. A splice variant (C-α₁) of the α₁-subunit, lacking at least the first 236 amino acids has been described by Sharina et al. 2008 and has been shown to be expressed in differentiating human embryonic cells. Wagner et al. 2005 have shown that the amino acids 61-128 of the α₁-subunit are mandatory for quantitative heterodimerization implying that the C-α₁-splice variant should lose its capacity to dimerize quantitatively. METHODOLOGY/PRINCIPAL FINDINGS: In the current study we demonstrate preserved quantitative dimerization of the C-α₁-splice by co-purification with the β₁-subunit. In addition we used fluorescence resonance energy transfer (FRET) based on fluorescence lifetime imaging (FLIM) using fusion proteins of the β₁-subunit and the α₁-subunit or the C-α₁ variant with ECFP or EYFP. Analysis of the respective combinations in HEK-293 cells showed that the fluorescence lifetime was significantly shorter (≈0.3 ns) for α₁/β₁ and C-α₁/β₁ than the negative control. In addition we show that lack of the amino-terminus in the α₁ splice variant directs it to a more oxidized subcellular compartment. CONCLUSIONS/SIGNIFICANCE: We conclude that the amino-terminus of the α₁-subunit is dispensable for dimerization in-vivo and ex-vivo, but influences the subcellular trafficking
    corecore