3,720 research outputs found

    Inflation with Non-minimal Gravitational Couplings and Supergravity

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    We explore in the supergravity context the possibility that a Higgs scalar may drive inflation via a non-minimal coupling to gravity characterised by a large dimensionless coupling constant. We find that this scenario is not compatible with the MSSM, but that adding a singlet field (NMSSM, or a variant thereof) can very naturally give rise to slow-roll inflation. The inflaton is necessarily contained in the doublet Higgs sector and occurs in the D-flat direction of the two Higgs doublets.Comment: 13 pages, 1 figur

    Intercultural New Media Studies: The Next Frontier in intercultural Communication

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    New media (ICT\u27s) are transforming communication across cultures. Despite this revolution in cross cultural contact, communication researchers have largely ignored the impact of new media on intercultural communication. This groundbreaking article defines the parameters of a new field of inquiry called Intercultural New Media Studies (INMS), which explores the intersection between ICT\u27s and intercultural communication. Composed of two research areas—(1) new media and intercultural communication theory and (2) culture and new media—INMS investigates new digital theories of intercultural contact as well as refines and expands twentieth-century intercultural communication theories, examining their salience in a digital world. INMS promises to increase our understanding of intercultural communication in a new media age and is the next frontier in intercultural communication

    Development of a PPE visor for female healthcare workers

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    During the COVID-19 pandemic the demand for personal protective equipment (PPE) has increased dramatically. However, the lack of PPE designed specifically for women is leaving many without adequate protection, as current “universal” solutions fail to address female healthcare workers’ varied needs. Instead, current solutions present users with a host of problems, including discomfort, hindrance, incompatibility with other wearable items, and adjustment difficulties. This paper explores and reflects upon the design thinking approach used to develop a PPE visor for female healthcare workers while following a user-centred design approach/methodology

    Spur pruning leads to distinctly different phenolic profiles of base sparkling wines than cane pruning

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    Winter pruning is the principal method for regulating yield in viticulture. The aim of this work was to investigate the effectiveness of cane and spur pruning on yield, and on grape and wine composition. Cane and spur pruning were investigated in Vitis vinifera L. 'Pinot noir' and 'Chardonnay' vertically-shoot-positioned vines over three seasons. Effects on vine carbohydrates, yield components, leaf area, grape and base wine composition were determined. The canopies of spur pruned vines established more rapidly than cane pruned vines in the 2009/10 season, for both 'Pinot noir' and 'Chardonnay'. The canopies were denser under spur pruning than cane pruning. Pruning treatment had no effect on total yield for either cultivar in any of the three seasons. Total soluble solids (TSS) and titratable acidity were unaffected by pruning treatment, except in 2012 where TSS and pH were higher for spur pruned 'Chardonnay' vines. Apart from spur pruned 'Pinot noir' vine wood being higher in starch in the winter of 2011, overwintering starch and soluble sugar concentrations were not different between pruning treatments for 'Pinot noir' and 'Chardonnay'. Although not different in yield or basic fruit composition, fruit from spur pruned vines resulted in distinctly different phenolic profiles of base wines, with cane pruning appearing to negatively impact on the low molecular weight phenolics in the wine. The results presented here provide confidence that quality is not lessened, in fact could be improved, by shifting from the industry norm of cane to spur pruning for sparkling wine production in cool climates

    Representing complex data using localized principal components with application to astronomical data

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    Often the relation between the variables constituting a multivariate data space might be characterized by one or more of the terms: ``nonlinear'', ``branched'', ``disconnected'', ``bended'', ``curved'', ``heterogeneous'', or, more general, ``complex''. In these cases, simple principal component analysis (PCA) as a tool for dimension reduction can fail badly. Of the many alternative approaches proposed so far, local approximations of PCA are among the most promising. This paper will give a short review of localized versions of PCA, focusing on local principal curves and local partitioning algorithms. Furthermore we discuss projections other than the local principal components. When performing local dimension reduction for regression or classification problems it is important to focus not only on the manifold structure of the covariates, but also on the response variable(s). Local principal components only achieve the former, whereas localized regression approaches concentrate on the latter. Local projection directions derived from the partial least squares (PLS) algorithm offer an interesting trade-off between these two objectives. We apply these methods to several real data sets. In particular, we consider simulated astrophysical data from the future Galactic survey mission Gaia.Comment: 25 pages. In "Principal Manifolds for Data Visualization and Dimension Reduction", A. Gorban, B. Kegl, D. Wunsch, and A. Zinovyev (eds), Lecture Notes in Computational Science and Engineering, Springer, 2007, pp. 180--204, http://www.springer.com/dal/home/generic/search/results?SGWID=1-40109-22-173750210-

    Small Molecule Glycomimetics Inhibit Vascular Calcification via c-Met/Notch3/HES1 Signalling

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    © Copyright by the Author(s). Published by Cell Physiol Biochem Press. BACKGROUND/AIMS: Vascular calcification represents a huge clinical problem contributing to adverse cardiovascular events, with no effective treatment currently available. Upregulation of hepatocyte growth factor has been linked with vascular calcification, and thus, represent a potential target in the development of a novel therapeutic strategy. Glycomimetics have been shown to interrupt HGF-receptor signalling, therefore this study investigated the effect of novel glycomimetics on osteogenic signalling and vascular calcification in vitro. METHODS: Primary human vascular smooth muscle cells (HVSMCs) were induced by β-glycerophosphate (β-GP) and treated with 4 glycomimetic compounds (C1-C4). The effect of β-GP and C1-C4 on alkaline phosphatase (ALP), osteogenic markers and c-Met/Notch3/HES1 signalling was determined using colorimetric assays, qRT-PCR and western blotting respectively. RESULTS: C1-C4 significantly attenuated β-GP-induced calcification, as shown by Alizarin Red S staining and calcium content by day 14. In addition, C1-C4 reduced ALP activity and prevented upregulation of the osteogenic markers, BMP-2, Runx2, Msx2 and OPN. Furthermore, β-GP increased c-Met phosphorylation at day 21, an effect ameliorated by C2 and C4 and the c-Met inhibitor, crizotinib. We next interrogated the effects of the Notch inhibitor DAPT and confirmed an inhibition of β-GP up-regulated Notch3 protein by C2, DAPT and crizotinib compared to controls. Hes-1 protein upregulation by β-GP, was also significantly downregulated by C2 and DAPT. GOLD docking analysis identified a potential binding interaction of C1-C4 to HGF which will be investigated further. CONCLUSION: These findings demonstrate that glycomimetics have potent anti-calcification properties acting via HGF/c-Met and Notch signalling

    Estradiol and testosterone levels in patients undergoing partial hepatectomy - A possible signal for hepatic regeneration?

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    In five adult male patients undergoing a 40-60% partial hepatectomy, serum sex hormone levels before and after hepatic resection were determined. Blood was drawn immediately prior to each surgical procedure and at specified time points postoperatively. Compared to hormone levels found prior to surgery, following major hepatic resection, estradiol levels increase at 24 and 48 hr, while testosterone levels decline, being significantly reduced at 96 and 144 hr. These data demonstrate that adult males who undergo a 40-60% partial hepatectomy experience alterations in their sex hormone levels similar to those observed in male rats following a 70% hepatectomy. These changes in sex hormone levels have been associated in animals with an alteration of the sex hormone receptor status of the liver that is thought to participate in the initiation of the regenerative response. These studies suggest, but do not prove, that in man, as in the case of the rat, sex hormones may participate in the initiation of or at least modulate in part the regenerative response that occurs following a major hepatic resection. © 1989 Plenum Publishing Corporation

    The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation

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    The bacteria Pseudomonas syringae is a pathogen of many crop species and one of the model pathogens for studying plant and bacterial arms race coevolution. In the current model, plants perceive bacteria pathogens via plasma membrane receptors, and recognition leads to the activation of general defenses. In turn, bacteria inject proteins called effectors into the plant cell to prevent the activation of immune responses. AvrPto and AvrPtoB are two such proteins that inhibit multiple plant kinases. The tomato plant has reacted to these effectors by the evolution of a cytoplasmic resistance complex. This complex is compromised of two proteins, Prf and Pto kinase, and is capable of recognizing the effector proteins. How the Pto kinase is able to avoid inhibition by the effector proteins is currently unknown. Our data shows how the tomato plant utilizes dimerization of resistance proteins to gain advantage over the faster evolving bacterial pathogen. Here we illustrate that oligomerisation of Prf brings into proximity two Pto kinases allowing them to avoid inhibition by the effectors by transphosphorylation and to activate immune responses

    The Nrf2 inhibitor brusatol is a potent antitumour agent in an orthotopic mouse model of colorectal cancer

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    © Evans et al. Nrf2 is a transcription factor that regulates cellular stress response and irinotecan-metabolising pathways. Its aberrant activity has been reported in a number of cancers, although relatively few studies have explored a role for Nrf2 in colorectal cancer (CRC). This study assessed the expression of Nrf2 in patient CRC tissues and explored the effect of Nrf2 modulation alone, or in combination with irinotecan, in human (HCT116) and murine (CT26) cell lines in vitro and in an orthotopic syngeneic mouse model utilising bioluminescent imaging. Using a tissue microarray, Nrf2 was found to be overexpressed (p < 0.01) in primary CRC and metastatic tissue relative to normal colon, with a positive correlation between Nrf2 expression in matched primary and metastatic samples. In vitro experiments in CRC cell lines revealed that Nrf2 siRNA and brusatol, which is known to inhibit Nrf2, decreased viability and sensitised cells to irinotecan toxicity. Furthermore, brusatol effectively abrogated CRC tumour growth in subcutaneously and orthotopicallyallografted mice, resulting in an average 8-fold reduction in luminescence at the study end-point (p=0.02). Our results highlight Nrf2 as a promising drug target in the treatment of CRC

    Glycomimetics; A Novel Class of Drugs to Protect Against Free Fatty Acid-Induced Endothelial Dysfunction

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    Background Endothelial dysfunction is a key player in cardiovascular disease (CVD) complications and novel drugs are required to treat this pathological process. Glycosaminoglycans (GAGs) are key molecules that regulate signalling in many biological processes and drugs that mimic their structure could be a novel source of therapeutics to target specific CVD pathways. Purpose We have synthesised a set of four glycomimetic compounds and our objective was to determine whether they could activate protective pathways in endothelial cells subjected to fatty acid-induced endothelial dysfunction. Methods Glycomimetics, C1-C4, were synthesised by the stepwise transformation of 2,5-dihydroxybenzoic acid to a range of 2,5-substituted benzoic acid derivatives, incorporating the key sulphate groups to mimic heparan sulphate. Human Umbilical Vein Endothelial Cells (HUVECs) were treated with glycomimetics (1µM) in the presence or absence of the free fatty acid, palmitate. DAF-2 and H2DCF-DA assays were used to determine NO and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity ssays were also carried out. RT-PCR and western blotting were utilised to measure Akt, eNOS, Nrf-2, NQO-1 and HO-1 expression. Endothelial function was determined ex vivo using acetylcholine-induced endothelium-dependent relaxation in mouse thoracic aortic rings by wire myography. Results All four glycomimetics protected against palmitate-induced oxidative stress and enhanced NO production in vitro via upregulation of Akt/eNOS signalling, activation of the Nrf2/ARE pathway and down-regulation of ROS-induced lipid peroxidation. Under palmitate-induced oxidative stress, ex vivo endothelium-dependent relaxation was significantly enhanced by all four glycomimetics. Furthermore, the glycomimetics did not induce HUVEC activation, as determined by lack of ICAM-1 protein. Conclusion We have developed a new set of small molecule glycomimetics that do not activate ECs and protect against free fatty acid-induced endothelial dysfunction both in vitro and ex vivo. Future work will focus on developing the glycomimetics into drug-like therapies that target endothelial damage
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