2,432 research outputs found

    YY1 negatively regulates mouse myelin proteolipid protein (Plp1) gene expression in oligodendroglial cells

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    YY1 (Yin and Yang 1) is a multifunctional, ubiquitously expressed, zinc finger protein that can act as a transcriptional activator, repressor, or initiator element binding protein. Previous studies have shown that YY1 modulates the activity of reporter genes driven by the myelin PLP (proteolipid protein) (PLP1/Plp1) promoter. However, it is known that Plp1 intron 1 DNA contains regulatory elements that are required for the dramatic increase in gene activity, coincident with the active myelination period of CNS (central nervous system) development. The intron in mouse contains multiple prospective YY1 target sites including one within a positive regulatory module called the ASE (anti-silencer/enhancer) element. Results presented here demonstrate that YY1 has a negative effect on the activity of a Plp1-lacZ fusion gene [PLP(+)Z] in an immature oligodendroglial cell line (Oli-neu) that is mediated through sequences present in Plp1 intron 1 DNA. Yet YY1 does not bind to its alleged site in the ASE (even though the protein is capable of recognizing a target site in the promoter), indicating that the down-regulation of PLP(+)Z activity by YY1 in Oli-neu cells does not occur through a direct interaction of YY1 with the ASE sequence. Previous studies with Yy1 conditional knockout mice have demonstrated that YY1 is essential for the differentiation of oligodendrocyte progenitors. Nevertheless, the current study suggests that YY1 functions as a repressor (not an activator) of Plp1 gene expression in immature oligodendrocytes. Perhaps YY1 functions to keep the levels of PLP in check in immature cells before vast quantities of the protein are needed in mature myelinating oligodendrocytes

    Controlled Growth of Carbon Spheres Through the Mg-Reduction Route

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    Hollow spheres, hollow capsules and solid spheres of carbon were selectively synthesized by Mg-reduction of hexachlorobutadiene at appropriate reaction conditions. X-ray powder diffraction and Raman spectra reveal that the as-prepared materials have a well-ordered structure. A possible formation mechanism has been proposed

    DecGPU: distributed error correction on massively parallel graphics processing units using CUDA and MPI

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    <p>Abstract</p> <p>Background</p> <p>Next-generation sequencing technologies have led to the high-throughput production of sequence data (reads) at low cost. However, these reads are significantly shorter and more error-prone than conventional Sanger shotgun reads. This poses a challenge for the <it>de novo </it>assembly in terms of assembly quality and scalability for large-scale short read datasets.</p> <p>Results</p> <p>We present DecGPU, the first parallel and distributed error correction algorithm for high-throughput short reads (HTSRs) using a hybrid combination of CUDA and MPI parallel programming models. DecGPU provides CPU-based and GPU-based versions, where the CPU-based version employs coarse-grained and fine-grained parallelism using the MPI and OpenMP parallel programming models, and the GPU-based version takes advantage of the CUDA and MPI parallel programming models and employs a hybrid CPU+GPU computing model to maximize the performance by overlapping the CPU and GPU computation. The distributed feature of our algorithm makes it feasible and flexible for the error correction of large-scale HTSR datasets. Using simulated and real datasets, our algorithm demonstrates superior performance, in terms of error correction quality and execution speed, to the existing error correction algorithms. Furthermore, when combined with Velvet and ABySS, the resulting DecGPU-Velvet and DecGPU-ABySS assemblers demonstrate the potential of our algorithm to improve <it>de novo </it>assembly quality for <it>de</it>-<it>Bruijn</it>-graph-based assemblers.</p> <p>Conclusions</p> <p>DecGPU is publicly available open-source software, written in CUDA C++ and MPI. The experimental results suggest that DecGPU is an effective and feasible error correction algorithm to tackle the flood of short reads produced by next-generation sequencing technologies.</p

    Vehicles for atopic dermatitis therapies: more than just a placebo

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    A topical vehicle is a ‘carrier system’ for an active pharmaceutical (or cosmetic) substance, referred to hereafter as the drug, but a vehicle may also be used on its own as an emollient to ameliorate dry skin. It is well established that the vehicle plays an important role in determining the bioavailability of a given drug at its ultimate target within the skin. Yet in the treatment of atopic eczema/dermatitis (AD), wherein the structure and function of the skin's outer barrier play a pivotal role in the development and course of the condition, the interaction of the vehicle with this barrier carries a particular importance. It is now clear that the often-considered inert excipients of a vehicle bring about changes within the skin at the molecular level that promote barrier restoration and enhance innate immune defenses with therapeutic value to AD patients. Moreover, the vehicle control in randomized controlled trials (RCTs) increasingly displays significant efficacy. In light of this, we consider the implications of vehicle design in relation to AD pathophysiology and the role vehicles play as controls in RCTs of new drug treatments for this condition

    A New Era in the Quest for Dark Matter

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    There is a growing sense of `crisis' in the dark matter community, due to the absence of evidence for the most popular candidates such as weakly interacting massive particles, axions, and sterile neutrinos, despite the enormous effort that has gone into searching for these particles. Here, we discuss what we have learned about the nature of dark matter from past experiments, and the implications for planned dark matter searches in the next decade. We argue that diversifying the experimental effort, incorporating astronomical surveys and gravitational wave observations, is our best hope to make progress on the dark matter problem.Comment: Published in Nature, online on 04 Oct 2018. 13 pages, 1 figur

    Therapy-induced tumour secretomes promote resistance and tumour progression.

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    Drug resistance invariably limits the clinical efficacy of targeted therapy with kinase inhibitors against cancer. Here we show that targeted therapy with BRAF, ALK or EGFR kinase inhibitors induces a complex network of secreted signals in drug-stressed human and mouse melanoma and human lung adenocarcinoma cells. This therapy-induced secretome stimulates the outgrowth, dissemination and metastasis of drug-resistant cancer cell clones and supports the survival of drug-sensitive cancer cells, contributing to incomplete tumour regression. The tumour-promoting secretome of melanoma cells treated with the kinase inhibitor vemurafenib is driven by downregulation of the transcription factor FRA1. In situ transcriptome analysis of drug-resistant melanoma cells responding to the regressing tumour microenvironment revealed hyperactivation of several signalling pathways, most prominently the AKT pathway. Dual inhibition of RAF and the PI(3)K/AKT/mTOR intracellular signalling pathways blunted the outgrowth of the drug-resistant cell population in BRAF mutant human melanoma, suggesting this combination therapy as a strategy against tumour relapse. Thus, therapeutic inhibition of oncogenic drivers induces vast secretome changes in drug-sensitive cancer cells, paradoxically establishing a tumour microenvironment that supports the expansion of drug-resistant clones, but is susceptible to combination therapy

    Image informatics strategies for deciphering neuronal network connectivity

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    Brain function relies on an intricate network of highly dynamic neuronal connections that rewires dramatically under the impulse of various external cues and pathological conditions. Among the neuronal structures that show morphologi- cal plasticity are neurites, synapses, dendritic spines and even nuclei. This structural remodelling is directly connected with functional changes such as intercellular com- munication and the associated calcium-bursting behaviour. In vitro cultured neu- ronal networks are valuable models for studying these morpho-functional changes. Owing to the automation and standardisation of both image acquisition and image analysis, it has become possible to extract statistically relevant readout from such networks. Here, we focus on the current state-of-the-art in image informatics that enables quantitative microscopic interrogation of neuronal networks. We describe the major correlates of neuronal connectivity and present workflows for analysing them. Finally, we provide an outlook on the challenges that remain to be addressed, and discuss how imaging algorithms can be extended beyond in vitro imaging studies

    SiC Nanowires Synthesized by Rapidly Heating a Mixture of SiO and Arc-Discharge Plasma Pretreated Carbon Black

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    SiC nanowires have been synthesized at 1,600 °C by using a simple and low-cost method in a high-frequency induction furnace. The commercial SiO powder and the arc-discharge plasma pretreated carbon black were mixed and used as the source materials. The heating-up and reaction time is less than half an hour. It was found that most of the nanowires have core-shell SiC/SiO2nanostructures. The nucleation, precipitation, and growth processes were discussed in terms of the oxide-assisted cluster-solid mechanism

    A Potential Role for Drosophila Mucins in Development and Physiology

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    Vital vertebrate organs are protected from the external environment by a barrier that to a large extent consists of mucins. These proteins are characterized by poorly conserved repeated sequences that are rich in prolines and potentially glycosylated threonines and serines (PTS). We have now used the characteristics of the PTS repeat domain to identify Drosophila mucins in a simple bioinformatics approach. Searching the predicted protein database for proteins with at least 4 repeats and a high ST content, more than 30 mucin-like proteins were identified, ranging from 300–23000 amino acids in length. We find that Drosophila mucins are present at all stages of the fly life cycle, and that their transcripts localize to selective organs analogous to sites of vertebrate mucin expression. The results could allow for addressing basic questions about human mucin-related diseases in this model system. Additionally, many of the mucins are expressed in selective tissues during embryogenesis, thus revealing new potential functions for mucins as apical matrix components during organ morphogenesis
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