1,905 research outputs found

    An analysis of value-chains and market development to support the smaller-scale production of pork by ethnic minority women in the Northern Mountainous Region of Vietnam

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    HIGHLIGHTS: *Using information gathered from visits to field sites and interviews with farmers in 2019, the authors of this report or Guidance Memo document the challenges faced by socially and economically-marginalized women in the Northern Mountainous Region (NMR) of Vietnam who raise local or heritage pigs on small-scales to supplement their family income. *These women have been greatly affected by recent growth in industrial-scale pork production in Vietnam. *Moreover, the African Swine Fever crisis in northern Vietnam in mid/late 2019 threatens to put an end to raising local/heritage breeds on small scales in NMR. *But there is clear evidence that smaller-scale pork production in NMR is viable and is good socially, economically, environmentally, and for animal welfare. *A number of concrete, practical ways to support small-scale producers are suggested, from providing training in pig breeding to simple steps like teaching the small producers to use Facebook to attract customers

    Low-Phosphate Chromatin Dynamics Predict a Cell Wall Remodeling Network in Rice Shoots

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    © 2020 American Society of Plant Biologists. All Rights Reserved. Phosphorus (P) is an essential plant macronutrient vital to fundamental metabolic processes. Plant-available P is low in most soils, making it a frequent limiter of growth. Declining P reserves for fertilizer production exacerbates this agricultural challenge. Plants modulate complex responses to fluctuating P levels via global transcriptional regulatory networks. Although chromatin structure plays a substantial role in controlling gene expression, the chromatin dynamics involved in regulating P homeostasis have not been determined. Here we define distinct chromatin states across the rice (Oryza sativa) genome by integrating multiple chromatin marks, including the H2A.Z histone variant, H3K4me3 modification, and nucleosome positioning. In response to P starvation, 40% of all protein-coding genes exhibit a transition from one chromatin state to another at their transcription start site. Several of these transitions are enriched in subsets of genes differentially expressed under P deficiency. The most prominent subset supports the presence of a coordinated signaling network that targets cell wall structure and is regulated in part via a decrease of H3K4me3 at transcription start sites. The P starvation-induced chromatin dynamics and correlated genes identified here will aid in enhancing P use efficiency in crop plants, benefitting global agriculture

    Retigabine holds KV7 channels open and stabilizes the resting potential

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    The anticonvulsant Retigabine is a KV7 channel agonist used to treat hyperexcitability disorders in humans. Retigabine shifts the voltage dependence for activation of the heteromeric KV7.2/KV7.3 channel to more negative potentials, thus facilitating activation. Although the molecular mechanism underlying Retigabine\u27s action remains unknown, previous studies have identified the pore region of KV7 channels as the drug\u27s target. This suggested that the Retigabine-induced shift in voltage dependence likely derives from the stabilization of the pore domain in an open (conducting) conformation. Testing this idea, we show that the heteromeric KV7.2/KV7.3 channel has at least two open states, which we named O1 and O2, with O2 being more stable. The O1 state was reached after short membrane depolarizations, whereas O2 was reached after prolonged depolarization or during steady state at the typical neuronal resting potentials. We also found that activation and deactivation seem to follow distinct pathways, suggesting that the KV7.2/KV7.3 channel activity displays hysteresis. As for the action of Retigabine, we discovered that this agonist discriminates between open states, preferentially acting on the O2 state and further stabilizing it. Based on these findings, we proposed a novel mechanism for the therapeutic effect of Retigabine whereby this drug reduces excitability by enhancing the resting potential open state stability of KV7.2/KV7.3 channels. To address this hypothesis, we used a model for action potential (AP) in Xenopus laevis oocytes and found that the resting membrane potential became more negative as a function of Retigabine concentration, whereas the threshold potential for AP firing remained unaltered

    Rice H2A.Z negatively regulates genes responsive to nutrient starvation but promotes expression of key housekeeping genes

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    © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. The H2A.Z histone variant plays a role in the modulation of environmental responses, but the nature of the associated mechanisms remains enigmatic. We investigated global H2A.Z deposition and transcriptomic changes in rice (Oryza sativa) upon exposure to phosphate (Pi) deficiency and in response to RNAi knockdown of OsARP6, which encodes a key component of the H2A.Z exchange complex. Both Pi deficiency and OsARP6-knockdown resulted in similar, profound effects on global H2A.Z distribution. H2A.Z in the gene body of stress-responsive genes was negatively correlated with gene expression, and this was more apparent in response to Pi deficiency. In contrast, the role of H2A.Z at the transcription start site (TSS) was more context dependent, acting as a repressor of some stress-responsive genes, but an activator of some genes with housekeeping functions. This was especially evident upon OsARP6-knockdown, which resulted in down-regulation of a number of genes linked to chloroplast function that contained decreases in H2A.Z at the TSS. Consistently, OsARP6-RNAi plants exhibited lower chlorophyll content relative to the wild-type. Our results demonstrate that gene body-localized H2A.Z plays a prominent role in repressing stress-responsive genes under non-inductive conditions, whereas H2A.Z at the TSS functions as a positive or negative regulator of transcription

    Universal logic with encoded spin qubits in silicon

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    Qubits encoded in a decoherence-free subsystem and realized in exchange-coupled silicon quantum dots are promising candidates for fault-tolerant quantum computing. Benefits of this approach include excellent coherence, low control crosstalk, and configurable insensitivity to certain error sources. Key difficulties are that encoded entangling gates require a large number of control pulses and high-yielding quantum dot arrays. Here we show a device made using the single-layer etch-defined gate electrode architecture that achieves both the required functional yield needed for full control and the coherence necessary for thousands of calibrated exchange pulses to be applied. We measure an average two-qubit Clifford fidelity of 97.1±0.2%97.1 \pm 0.2\% with randomized benchmarking. We also use interleaved randomized benchmarking to demonstrate the controlled-NOT gate with 96.3±0.7%96.3 \pm 0.7\% fidelity, SWAP with 99.3±0.5%99.3 \pm 0.5\% fidelity, and a specialized entangling gate that limits spreading of leakage with 93.8±0.7%93.8 \pm 0.7\% fidelity

    Lipidomic Analysis of Glioblastoma Multiforme Using Mass Spectrometry

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    Glioblastoma multiforme (GBM) is the most common and malignant form of primary brain tumors. It is highly invasive and current treatment options have not improved the survival rate over the past twenty years. Novel approaches and technologies from systems biology have the potential to identify biomarkers that could serve as new therapeutic targets for GBM. This study employed lipid profiling technology to investigate lipid biomarkers in ectopic and orthotopic human GBM xenograft models. Primary patient cell lines, GBM10 and GBM43, were injected into the flank and the right cerebral hemisphere of NOD/SCID mice. Tumors were harvested from the brain and flank and proteins, metabolites, and lipids extracted from each sample. Reverse phase based high performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry (LC-FTMS) was used to analyze the lipid profiles of tumor samples. Statistical and clustering analyses were performed to detect differences. Over 500 lipids were identified in each tumor model and lipids with the greatest fold effect in the comparison of ectopic versus orthotopic tumor models fell predominantly into four main classes of lipids: glycosphingolipids, glycerophoshpoethanolamines, triradylglycerols, and glycerophosphoserines. Lipidomic analysis revealed differences in glycosphingolipid and triglyceride profiles when the same tumor was propagated in the flank versus the brain. These results underscore the importance of the surrounding physiological environment on tumor development and are consistent with the hypothesis that specific classes of lipids are critical for GBM tumor growth in different anatomical sites

    Lipidomic Analysis of Glioblastoma Multiforme Using Mass Spectrometry

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    Glioblastoma multiforme (GBM) is the most common and malignant form of primary brain tumors. It is highly invasive and current treatment options have not improved the survival rate over the past twenty years. Novel approaches and technologies from systems biology have the potential to identify biomarkers that could serve as new therapeutic targets for GBM. This study employed lipid profiling technology to investigate lipid biomarkers in ectopic and orthotopic human GBM xenograft models. Primary patient cell lines, GBM10 and GBM43, were injected into the flank and the right cerebral hemisphere of NOD/SCID mice. Tumors were harvested from the brain and flank and proteins, metabolites, and lipids extracted from each sample. Reverse phase based high performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry (LC-FTMS) was used to analyze the lipid profiles of tumor samples. Statistical and clustering analyses were performed to detect differences. Over 500 lipids were identified in each tumor model and lipids with the greatest fold effect in the comparison of ectopic versus orthotopic tumor models fell predominantly into four main classes of lipids: glycosphingolipids, glycerophoshpoethanolamines, triradylglycerols, and glycerophosphoserines. Lipidomic analysis revealed differences in glycosphingolipid and triglyceride profiles when the same tumor was propagated in the flank versus the brain. These results underscore the importance of the surrounding physiological environment on tumor development and are consistent with the hypothesis that specific classes of lipids are critical for GBM tumor growth in different anatomical sites

    Flow batteries for energy management : novel algebraic modelling approaches to properly assess their value

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    Redox Flow Battery (RFB) systems are promising technologies for the multi-hour electrical energy storage that will be necessary for on-demand electricity supply based on wind and solar power. Deriving maximum value from a RFB requires optimisation of both the system design and its operation. In this work three novel algebraic modelling approaches are introduced to represent RFB operation more accurately while maintaining quick optimisation times. First the typical linear programming (LP) optimisation problem is re-posed in terms of current-density rather than power, allowing voltaic losses to be expressed as a quadratic function (QP). Secondly, it is then shown that the current-density framework supports a novel constraint for the avoidance of high cell voltage that may damage the stack. Thirdly, for the first time a binary variable (MIQP) to describe active/idle states is introduced. This allows coulombic leakage and pumping losses to be modelled as fixed terms without constantly draining the RFB, and it allows for the optimisation of pump rating in a VRFB. In a day-ahead energy management case study, it is found that the QP optimisation predicts an additional 19 % annual revenue when compared to the LP optimisation. This capture of the true flexibility of the RFB operation allows its full value to be assessed, and therefore advances the case for their deployment within the energy system. Furthermore, the formulations developed are not only applicable to RFBs but to the scheduling of other battery systems, particularly Li-ion, and balance of plant optimisation, such as the sizing of inverters and climate control systems in the context of parasitic losses
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