Signatures of strong correlation effects in RIXS on Cuprates

Recently, spin excitations in doped cuprates are measured using the resonant inelastic X-ray scattering (RIXS). The paramagnon dispersions show the large hardening effect in the electron-doped systems and seemingly doping-independence in the hole-doped systems, with the energy scales comparable to that of the antiferromagnetic magnons. This anomalous hardening effect was partially explained by using the strong coupling t-J model but with a three-site term(Nature communications 5, 3314 (2014)). However we show that hardening effect is a signature of strong coupling physics even without including this extra term. By considering the t-t'-t"-J model and using the Slave-Boson (SB) mean field theory, we obtain, via the spin-spin susceptibility, the spin excitations in qualitative agreement with the experiments. These anomalies is mainly due to the doping-dependent bandwidth. We further discuss the interplay between particle-hole-like and paramagnon-like excitations in the RIXS measurements.Comment: 7 pages, 6 figure

Plastic circular economy in the EU: Material Flow Analysis and Transition Analysis

Plastic is valued for its versatility, but concerns have been raised over the environmental impacts of plastic waste. A more in-depth investigation of the plastic system is still needed to understand current flows and factors to close the plastic cycle. This research applied a material flow analysis (MFA) and transition analysis (TA), using multilevel perspectives, to the plastic circular economy transition in the EU. The MFA covers over 400 categories of plastic-containing products with a detailed analysis of the final destination of waste. The TA identifies the interaction of barriers and drivers to use secondary plastics, with a focus on the regime level along the plastic value chain. The MFA results indicate the EU produced over 66  million tonnes (Mt) of plastic polymers/fibres and an estimated consumption for plastic products of 73 Mt in 2016. Plastic waste increases amounted to over 37 Mt, and a significant amount of plastic waste was not recovered back into plastics in the EU. The uncertainty analysis of MFA highlights important data quality issues that need to be addressed. To understand why using secondary plastics presents challenges, the TA mapped the factors across policies and standards, markets and business models, technology, and consumer preferences and behaviours that create a web of constraints and a web of drivers. TA results highlight that data-information-knowledge is the key gap as most of the aspects are cross-cutting. Different actors are involved in new business networks and play multiple roles in driving the co-evolutionary dynamic. The thesis concludes that significant data gaps need MFA-based knowledge to inform policies that address the barriers and the potential socio-technical changes that can reshape plastic flows. The cases playing out across the whole value chain and four different application areas provide insights that are potentially more widely applicable to the circular economy transition processes in Europe

Lipid and Protein Organizations in Model Membrane Systems- Membrane Curvature, Lipid Structure, Domain Formation, and Membrane Binding Kinetics

The composition and morphology of cellular membranes are highly dynamic. Potential parameters modulating protein and lipid distributions in different organelles include membrane shapes and the structures of lipids and proteins. Moreover, the concept of lipid rafts provides a prevailing view where nanodomains serve as centers for signal transduction, membrane trafficking, and cytoskeletal organization. In this contribution, we first investigated the lipid and protein organizations as a function of membrane curvature. To this end, a system consisting of solid-supported wavy membranes that exhibits a continuous curvature distribution with positive and negative curvature ranges was fabricated. Spatial distributions of ENTH (epsin N-terminal homology) domain and N-BAR (Bin-Amphiphysin-Rvs) domains derived from the proteins Endophilin and BIN-1 were found to vary approximately linearly with membrane curvature. In contrast, streptavidin and fluorescent lipid analogues exhibited homogenous distributions on wavy membranes. Fluorescence recovery after photobleaching and single-molecule tracking experiments revealed that protein domains remain laterally fluid in the curved regions. We next studied the membrane organization with respect to lipid structures, more specifically, the length and degree of saturation of acyl chains of lipids. The ganglioside GM1 binds cholera toxin (CT) on host cells and carries it retrograde from the plasma membrane (PM) through endosomes, the trans-Golgi network (TGN), and the endoplasmic reticulum (ER) to induce toxicity. To elucidate how a membrane lipid can specify trafficking in these pathways, GM1 isoforms with alternate ceramide domains were synthesized and their partitioning between liquid-ordered (Lo) and liquid-disordered (Ld) phases in GUVs was imaged. GM1 with differing ceramides showed distinct phase-partitioning behaviors. Furthermore, crosslinking of GM1 by cholera toxin subunit B (CTB) was found to drive phase partitioning shift from less preferential phase preference to exclusively Ld or Lo phases. To shed light on the stability of lipid domains, factors qwhich affect line tension were discussed and potential line-active molecules were examined. We found that the presence of cone-shaped diacylglycerol decreases line tension, while the commonly used fluorescent lipid, Texas-Red DHPE tends to increase line tension. Additionally, to bridge the connection between thermodynamics to highly dynamic cellular environments, we developed a single liposome-based kinetics system which allowed us to examine membrane binding kinetics of proteins as a function of membrane curvature. Overall, these measurements help provide an integrated view of biophysical and structural parameters underlying organizations of lipids and proteins

SARS-CoV Regulates Immune Function-Related Gene Expressions in Human Monocytic Cells

Background: Severe Acute Respiratory Syndrome (SARS) is characterized by acute respiratory distress (ARDS) and pulmonary fibrosis, and the monocyte/macrophage is the key player in the pathogenesis of SARS.
 
Methods: In this study, we compared the transcriptional profiles of SARS coronavirus (SARS-CoV) infected monocytic cells against that infected by coronavirus 229E (CoV-229E). Total RNA was extracted from infected DC-SIGN transfected monocytes (THP-1-DC-SIGN) at 6 and 24 h after infection and the gene expression was profiled by oligonucleotide-based microarray. 

Results: Analysis of immune-related gene expression profiles showed that 24 h after SARS-CoV infection, (i) IFN-alpha/beta-inducible and cathepsin/proteosome genes were down-regulated; (ii) the hypoxia/hyperoxia-related genes were up-regulated; and (iii) the TLR/TLR-signaling, cytokine/cytokine receptor-related, chemokine/chemokine receptor-related, the lysosome-related, MHC/chaperon-related, and fibrosis-related genes were differentially regulated. 

Conclusion: These results elucidate that monocyte/macrophage dysfunction and dysregulation of fibrosis-related genes are two important pathogenic events of SARS. 
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Generalized quantum measurement

We overcome one of Bell's objections to `quantum measurement' by generalizing the definition to include systems outside the laboratory. According to this definition a {\sl generalized quantum measurement} takes place when the value of a classical variable is influenced significantly by an earlier state of a quantum system. A generalized quantum measurement can then take place in equilibrium systems, provided the classical motion is chaotic. This paper deals with this classical aspect of quantum measurement, assuming that the Heisenberg cut between the quantum dynamics and the classical dynamics is made at a very small scale. For simplicity, a gas with collisions is modelled by an `Arnold gas'.Comment: 11 pages, LaTeX, no figures, title change

The P/E Ratio And Profitability

This paper examines the relation between the forward price-to-earnings (P/E) ratio and profitability. Consistent with the theoretical predictions of Ohlson and Zhan (2006), this paper finds a U-shaped relation between the forward P/E ratio and return on equity (ROE). Besides, firms with high P/E ratios tend to have lower ROE in the subsequent years, and their ROE is very volatile and wide-distributed. Using the GSCORE from Mohanram (2005), this paper separates winners from losers among high P/E firms. Firms with high GSCORE yield higher earnings growth, sale growth, ROE, and excess stock returns in the following years