711 research outputs found

    Inside‐out: synergising leaf biochemical traits with stomatal‐regulated water fluxes to enhance transpiration modelling during abiotic stress

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    As the global climate continues to change, plants will increasingly experience abiotic stress(es). Stomata on leaf surfaces are the gatekeepers to plant interiors, regulating gaseous exchanges that are crucial for both photosynthesis and outward water release. To optimise future crop productivity, accurate modelling of how stomata govern plant–environment interactions will be crucial. Here, we synergise optical and thermal imaging data to improve modelled transpiration estimates during water and/or nutrient stress (where leaf N is reduced). By utilising hyperspectral data and partial least squares regression analysis of six plant traits and fluxes in wheat (Triticum aestivum), we develop a new spectral vegetation index; the Combined Nitrogen and Drought Index (CNDI), which can be used to detect both water stress and/or nitrogen deficiency. Upon full stomatal closure during drought, CNDI shows a strong relationship with leaf water content (r2 = 0.70), with confounding changes in leaf biochemistry. By incorporating CNDI transformed with a sigmoid function into thermal-based transpiration modelling, we have increased the accuracy of modelling water fluxes during abiotic stress. These findings demonstrate the potential of using combined optical and thermal remote sensing-based modelling approaches to dynamically model water fluxes to improve both agricultural water usage and yields

    Hydroethanolic Allium sativum extract accelerates excision wound healing: evidence for roles of mast-cell infiltration and intracytoplasmic carbohydrate ratio

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    ABSTRACT The present study was designed to evaluate the in vivo effect of Allium sativum (garlic) hydroalcoholic extract on wound healing in rats. For this purpose, 72 mature Wistar rats were divided into four groups (n=18/each) to receive no treatment, placebo, Cicalfate(r), or 2% Allium sativum (AS) extract, administered topically to the wound area, for 21 days. Following the experimental period, tissue samples were dissected out and underwent to histopathological analyses. Fibroblasts, fibrocytes, mast cells, intra-cytoplasmic carbohydrate ratio, neovascularization, collagen deposition, and re-epithelialization were analyzed in all groups. Animals in the treated groups showed significant enhancement in fibroblast, fibrocyte, and mast-cell distribution. Significantly higher neovascularization was observed on day 3 after wound induction in AS-treated animals versus those in the placebo, Cicalfate, and untreated groups (P<0.05). A dose-dependent, significantly higher intra-cytoplasmic carbohydrate storage was observed in treated animals. Our data show that AS promotes wound healing due to its preliminary impact on mast-cell distribution, which enhanced collagen synthesis and upregulated angiogenesis, and shortened the healing process by enhancing the intra-cytoplasmic carbohydrate ratio

    The Vega debris disc: A view from Herschel

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    We present five band imaging of the Vega debris disc obtained using the Herschel Space Observatory. These data span a wavelength range of 70-500 mu m with full-width half-maximum angular resolutions of 5.6-36.9 ''. The disc is well resolved in all bands, with the ring structure visible at 70 and 160 mu m. Radial profiles of the disc surface brightness are produced, and a disc radius of 11 '' (similar to 85AU) is determined. The disc is seen to have a smooth structure thoughout the entire wavelength range, suggesting that the disc is in a steady state, rather than being an ephemeral structure caused by the recent collision of two large planetesimals

    Layered control architectures in robots and vertebrates

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    We revieiv recent research in robotics, neuroscience, evolutionary neurobiology, and ethology with the aim of highlighting some points of agreement and convergence. Specifically, we com pare Brooks' (1986) subsumption architecture for robot control with research in neuroscience demonstrating layered control systems in vertebrate brains, and with research in ethology that emphasizes the decomposition of control into multiple, intertwined behavior systems. From this perspective we then describe interesting parallels between the subsumption architecture and the natural layered behavior system that determines defense reactions in the rat. We then consider the action selection problem for robots and vertebrates and argue that, in addition to subsumption- like conflict resolution mechanisms, the vertebrate nervous system employs specialized selection mechanisms located in a group of central brain structures termed the basal ganglia. We suggest that similar specialized switching mechanisms might be employed in layered robot control archi tectures to provide effective and flexible action selection

    USP50 suppresses alternative RecQ helicase use and deleterious DNA2 activity during replication.

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    Mammalian DNA replication relies on various DNA helicase and nuclease activities to ensure accurate genetic duplication, but how different helicase and nuclease activities are properly directed remains unclear. Here, we identify the ubiquitin-specific protease, USP50, as a chromatin-associated protein required to promote ongoing replication, fork restart, telomere maintenance, cellular survival following hydroxyurea or pyridostatin treatment, and suppression of DNA breaks near GC-rich sequences. We find that USP50 supports proper WRN-FEN1 localisation at or near stalled replication forks. Nascent DNA in cells lacking USP50 shows increased association of the DNA2 nuclease and RECQL4 and RECQL5 helicases and replication defects in cells lacking USP50, or FEN1 are driven by these proteins. Consequently, suppression of DNA2 or RECQL4/5 improves USP50-depleted cell resistance to agents inducing replicative stress and restores telomere stability. These data define an unexpected regulatory protein that promotes the balance of helicase and nuclease use at ongoing and stalled replication forks
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