We present a comprehensive theoretical study of the resonance fluorescence spectra of an coherently-driven quantum dot (QD) placed inside a high-Q semiconductor cavity and interacting with an ...acoustic-phonon bath. We derive a quantum master equation (ME) in the polaron frame, which includes exciton-phonon and exciton-cavity coupling to all orders. This work details and extends the theory used in a recent paper to describe the QD Mollow triplet in the regime of semiconductor cavity QED. Here, we introduce two ME forms, Nakajima-Zwanzig and time convolutionless (TC), both to second order in the system-phonon-reservoir perturbation. We show how the full width at half maximum of the Mollow-triplet sidebands varies as a function of the square of the Rabi frequency of the cw pump. Phonon-mediated cavity coupling also contributes to the spectral broadening of the Mollow-triplet, depending upon the exciton-cavity detuning and the strength of the exciton-cavity coupling rate. Finally, we calculate the fluorescence spectra for off-resonance cw driving and investigate the resulting Mollow-triplet line-widths.
Slope stability models traditionally use simple indicators of root system structure and strength when vegetation is included as a factor. However, additional root system traits should be considered ...when managing vegetated slopes to avoid shallow substrate mass movement. Traits including root distribution, length, orientation and diameter are recognized as influencing soil fixation, but do not consider the spatial and temporal dimensions of roots within a system. Thick roots act like soil nails on slopes and the spatial position of these thick roots determines the arrangement of the associated thin roots. Thin roots act in tension during failure on slopes and if they traverse the potential shear zone, provide a major contribution in protecting against landslides. We discuss how root traits change depending on ontogeny and climate, how traits are affected by the local soil environment and the types of plastic responses expressed by the plant. How a landslide engineer can use this information when considering slope stability and management strategies is discussed, along with perspectives for future research. This review encompasses many ideas, data and concepts presented at the Second International Conference ‘Ground Bio- and Eco-engineering: The Use of Vegetation to Improve Slope Stability—ICGBE2' held at Beijing, China, 14-18 July 2008. Several papers from this conference are published in this edition of Plant and Soil.
Understanding SARS-CoV-2 associated immune pathology is crucial to develop pan-effective vaccines and treatments. Here we investigate the immune events from the acute state up to four weeks post ...SARS-CoV-2 infection, in non-human primates (NHP) with heterogeneous pulmonary pathology. We show a robust migration of CD16 expressing monocytes to the lungs occurring during the acute phase, and we describe two subsets of interstitial macrophages (HLA-DR
CD206
): a transitional CD11c
CD16
cell population directly associated with IL-6 levels in plasma, and a long-lasting CD11b
CD16
cell population. Trafficking of monocytes is mediated by TARC (CCL17) and associates with viral load measured in bronchial brushes. We also describe associations between disease outcomes and high levels of cell infiltration in lungs including CD11b
CD16
macrophages and CD11b
neutrophils. Accumulation of macrophages is long-lasting and detectable even in animals with mild or no signs of disease. Interestingly, animals with anti-inflammatory responses including high IL-10:IL-6 and kynurenine to tryptophan ratios show less severe illness. Our results unravel cellular mechanisms of COVID-19 and suggest that NHP may be appropriate models to test immune therapies.
The tenderness of meat influences consumers' perceptions of its quality. Meat tenderness is a key quality characteristic that influences consumer satisfaction, repeat purchases, and willingness to ...pay higher prices for meat. Muscle fibers, connective tissues, and adipocytes are the main structural components of meat that contribute to its tenderness and texture. In the present review, we have focused on the role of connective tissue and its components in meat tenderness, specifically perimysial intramuscular connective tissue (IMCT) and its concept as an immutable "background toughness." The collagen contribution to cooked meat toughness can be altered by animal diet, compensatory growth, slaughter age, aging, and cooking. As well, progressive thickening of the perimysium leads to a progressive increase in shear force values in beef, pork, chicken, and this may occur prior to adipocyte formation as cattle finish in feedlots. Conversely, adipocyte accumulation in the perimysium can decrease cooked meat shear force, suggesting that the contribution of IMCT to meat toughness is complex and driven by both collagen structure and content. This review provides a theoretical foundation of information to modify IMCT components to improve meat tenderness.
This study explores whether partnering with the World Bank’s International Finance Corporation (IFC) protects foreign investors from aggressive actions by host countries’ governments. Building on the ...obsolescing bargaining model, we theorize that host states fear that hostile actions towards IFC-supported investments will damage their relationships with the World Bank. Within this context IFC support deters host government aggression towards investments. We assess our argument using country-level panel data as well as interviews with a sample of high-level managers. Findings suggest that IFC-support helps to reduce host state aggression against investing firms.
The di-heme family of succinate:quinone oxidoreductases is of particular interest, because its members support electron transfer across the biological membranes in which they are embedded. In the ...case of the di-heme-containing succinate:menaquinone reductase (SQR) from Gram-positive bacteria and other menaquinone-containing bacteria, this results in an electrogenic reaction. This is physiologically relevant in that it allows the transmembrane electrochemical proton potential Δp to drive the endergonic oxidation of succinate by menaquinone. In the case of the reverse reaction, menaquinol oxidation by fumarate, catalysed by the di-heme-containing quinol:fumarate reductase (QFR), evidence has been obtained that this electrogenic electron transfer reaction is compensated by proton transfer via a both novel and essential transmembrane proton transfer pathway (“E-pathway”). Although the reduction of fumarate by menaquinol is exergonic, it is obviously not exergonic enough to support the generation of a Δp. This compensatory “E-pathway” appears to be required by all di-heme-containing QFR enzymes and results in the overall reaction being electroneutral. In addition to giving a brief overview of progress in the characterization of other members of this diverse family, this contribution summarizes key evidence and progress in identifying constituents of the “E-pathway” within the framework of the crystal structure of the QFR from the anaerobic epsilon-proteobacterium Wolinella succinogenes at 1.78Å resolution. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.
•Progress in characterization of diverse di-heme complex-II family members.•Evidence for electrogenic catalysis by di-heme succinate:menaquinone reductases.•Evidence for electroneutral catalysis by di-heme menaquinol:fumarate reductases.•Water is an essential feature of transmembrane proton transfer via the “E-pathway”.•Bifurcation of the E-pathway via transient His-heme propionate H-bonded interaction.
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