4,133 research outputs found

    Gauging the Association of EFL Learnersā€™ Writing Proficiency and their Use of Metaphorical Language

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    This study examines whether higher-proficiency learners of English as a foreign language (EFL) produce expository writing that exhibits a greater density of metaphorically used words and expressions than what is found in texts produced by lower-proficiency peers. A comparison was made between essays written by 257 undergraduate English majors at three different year levels at a university in Viet Nam. The proportion of metaphorical language making up these essays was indeed found to be positively related to the studentsā€™ year levels and also to the grades awarded to the essays by independent assessors. A closer inspection of the data revealed that this positive association between proficiency and quantity of metaphorical expressions held true exclusively for grammatically correct instances of metaphorical language. The findings suggests that learners stand to gain considerablyā€”in terms of perceived writing proficiencyā€”from using words in their non-basic senses, as long as this use is also grammatically target-like

    The small heat-shock proteins IbpA and IbpB reduce the stress load of recombinant Escherichia coli and delay degradation of inclusion bodies

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    BACKGROUND: The permanently impaired protein folding during recombinant protein production resembles the stress encountered at extreme temperatures, under which condition the putative holding chaperones, IbpA/IbpB, play an important role. We evaluated the impact of ibpAB deletion or overexpression on stress responses and the inclusion body metabolism during production of yeast Ī±-glucosidase in Escherichia coli. RESULTS: Deletion of ibpAB, which is innocuous under physiological conditions, impaired culture growth during Ī±-glucosidase production. At higher temperatures, accumulation of stress proteins including disaggregation chaperones (DnaK and ClpB) and components of the RNA degradosome, enolase and PNP, was intensified. Overexpression of ibpAB, conversely, suppressed the heat-shock response under these conditions. Inclusion bodies of Ī±-glucosidase started to disaggregate after arrest of protein synthesis in a ClpB and DnaK dependent manner, followed by degradation or reactivation. IbpA/IbpB decelerated disaggregation and degradation at higher temperatures, but did hardly influence the disaggregation kinetics at 15Ā°C. Overexpression of ibpAB concomitant to production at 42Ā°C increased the yield of Ī±-glucosidase activity during reactivation. CONCLUSIONS: IbpA/IbpB attenuate the accumulation of stress proteins, and ā€“ at high temperatures ā€“ save disaggregated proteins from degradation, at the cost, however, of delayed removal of aggregates. Without ibpAB, inclusion body removal is faster, but cells encounter more intense stress and growth impairment. IbpA/IbpB thus exert a major function in cell protection during stressful situations

    Experimental Copper Deficiency, Chromium Deficiency and Additional Molybdenum Supplementation in Goats ā€“ Pathological Findings

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    Secondary copper (Cu) deficiency, chromium (Cr) deficiency and molybdenosis (Mo) has been suggested to cause the "mysterious" moose disease in the southwest of Sweden. The present experiment was performed on goats to investigate the clinical, chemical, and pathological alterations after 20 months feeding of a semi-synthetic diet deficient in Cu and Cr. Four groups were included in the study: control group (n = 4), Cu-deficient group (group 1, n = 4), Cr-deficient group (group 2, n = 2) and Cu+Cr-deficient group (group 3, n = 3). Group 3 was additionally supplemented with tetrathiomolybdate during the last 2 months of the experiment. Main histopathological findings in groups 1 and 3 were the lesions in the liver, characterised by a severe active fibrosis, bile duct proliferation, haemosiderosis and mild necroses. Additionally, degenerative alterations of the exocrine pancreas were prominent in groups 1 and 3. Lesions in group 3 were more pronounced than in group 1. In group 3, the skin showed an atrophic dermatosis, while in group 2 a crusty dermatitis caused by Candida spp. was observed. This study shows that liver, pancreas and skin are mainly affected by a long term deficiency of copper and the findings are complicated by molybdenum application while chromium deficiency produced no histomorphological effects in our study

    Entropic, electrostatic, and interfacial regimes in concentrated disordered ionic emulsions

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    We develop a free energy model that describes two key thermodynamic properties, the osmotic pressure Ī  and the linear elastic shear modulus Gā€²p (i.e. plateau storage modulus), of concentrated monodisperse emulsions which have isotropic, disordered, droplet structures, and are stabilized using ionic surfactants. This model effectively incorporates the concept of random close packing or jamming of repulsive spheres into a free energy F that depends on droplet volume fraction Ļ• and shear strain Ī³ both below and above the a critical jamming point Ļ•cā€‰ā‰ˆā€‰0.646. This free energy has three terms: entropic, electrostatic, and interfacial (EEI). By minimizing F with respect to an average droplet deformation parameter that links all three terms, we show that the entropic term is dominant for Ļ• well below Ļ•c, the electrostatic term is dominant for Ļ• near but below Ļ•c, and the interfacial term dominates for larger Ļ•. This EEI model describes measurements of Gā€²p(Ļ•) for charge-stabilized uniform emulsions having a wide range of droplet sizes, ranging from nanoscale to microscale, and it also is consistent with measurements of Ī (Ļ•). Moreover, it describes Gā€²p(Ļ•) for similar nanoemulsions after adding non-amphiphilic salt, when changes in the interfacial tension and the Debye screening length are properly taken into account. By unifying existing approaches, the EEI model predicts constitutive properties of concentrated ionic emulsions that have disordered, out-of-equilibrium structures through near- equilibrium free energy minimization, consistent with random driving Brownian excitations

    Derivation of Delay Equation Climate Models Using the Mori-Zwanzig Formalism

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    This is the author accepted manuscript. The final version is available from The Royal Society via the DOI in this record.Data access: The codes supporting this article have been uploaded as part of the supplementary material. They can also be found on the online repository figshare: https://doi.org/10.6084/m9.figshare.8085683.v1Models incorporating delay have been frequently used to understand climate variability phenomena, but often the delay is introduced through an ad-hoc physical reasoning, such as the propagation time of waves. In this paper, the Mori-Zwanzig formalism is introduced as a way to systematically derive delay models from systems of partial differential equations and hence provides a better justification for using these delay-type models. The Mori-Zwanzig technique gives a formal rewriting of the system using a projection onto a set of resolved variables, where the rewritten system contains a memory term. The computation of this memory term requires solving the orthogonal dynamics equation, which represents the unresolved dynamics. For nonlinear systems, it is often not possible to obtain an analytical solution to the orthogonal dynamics and an approximate solution needs to be found. Here, we demonstrate the Mori-Zwanzig technique for a two-strip model of the El Nino Southern Oscillation (ENSO) and explore methods to solve the orthogonal dynamics. The resulting nonlinear delay model contains an additional term compared to previously proposed ad-hoc conceptual models. This new term leads to a larger ENSO period, which is closer to that seen in observations.European Union Horizon 2020Dutch Science Foundation (NWOEngineering and Physical Sciences Research Council (EPSRC

    Integrated Access and Backhaul via Satellites

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    To allow flexible and cost-efficient network densification and deployment, the integrated access and backhaul (IAB) was recently standardized by the third generation partnership project (3GPP) as part of the fifth-generation new radio (5G-NR) networks. However, the current standardization only defines the IAB for the terrestrial domain, while non-terrestrial networks (NTNs) are yet to be considered for such standardization efforts. In this work, we motivate the use of IAB in NTNs, and we discuss the compatibility issues between the 3GPP specifications on IAB in 5G-NR and the satellite radio regulations. In addition, we identify the required adaptation from the 3GPP and/or satellite operators for realizing an NTN-enabled IAB operation. A case study is provided for a low earth orbit (LEO) satellite-enabled in-band IAB operation with orthogonal and non-orthogonal bandwidth allocation between access and backhauling, and under both time- and frequency-division duplex (TDD/FDD) transmission modes. Numerical results demonstrate the feasibility of IAB through satellites, and illustrate the superiority of FDD over TDD transmission. It is also shown that in the absence of precoding, non-orthogonal bandwidth allocation between the access and the backhaul can largely degrades the network throughput.Comment: This paper has been accepted for publication at the 2023 IEEE PIMRC conferenc
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