Phantom of the Hartle-Hawking instanton: connecting inflation with dark energy

If the Hartle-Hawking wave function is the correct boundary condition of our universe, the history of our universe will be well approximated by an instanton. Although this instanton should be classicalized at infinity, as long as we are observing a process of each history, we may detect a non-classicalized part of field combinations. When we apply it to a dark energy model, this non-classicalized part of fields can be well embedded to a quintessence and a phantom model, i.e., a quintom model. Because of the property of complexified instantons, the phantomness will be naturally free from a big rip singularity. This phantomness does not cause perturbative instabilities, as it is an effect emergent from the entire wave function. Our work may thus provide a theoretical basis for the quintom models, whose equation of state (EoS) can cross the cosmological constant boundary (CCB) phenomenologically.Comment: 20 pages, 7 figure

FDI AND SPILLOVERS IN CHINA: NON-LINEARITY AND ABSORPTIVE CAPACITY

Using a fixed effect variance decomposition model, we estimate SUR models to analyze FDI spillovers from contagion and spillovers from competition on local firms in China. While the former type of spillover mainly depends on the degree of foreign presence in the local industry, the latter kind is related to how foreign and local firms interact. The main conclusion is that FDI has been beneficial for the Chinese economy, but that spillovers are not evenly distributed across firms and industries. Spillovers from contagion tend to exhibit an inverse U-shaped pattern with respect to the degree of foreign presence at the industry level, whereas spillovers from competition exhibit a more linear pattern with respect to the level of technological sophistication in foreign firms. Industries with high absorptive capacity and/or high efficiency are the ones best equipped to take advantage of spillovers from foreign-owned firms. Moreover, there are signs of substantial competition between foreign-owned firms: an increase in the foreign capital share in an industry seems to have a stronger effect on incumbent foreign-owned firms than on domestic firms.Spillovers; China; FDI; Fixed effect variance decomposition

A Study of the Relationship Between the Grade Nine Students’ Perception Toward the School Climate and Their Satisfaction in the Xingyi No.1 Secondary School, Guizhou, China

The main purpose of this study was to determine the relationship between the grade nine students’ perception toward the school climate and their satisfaction in the Xingyi.No.1 Secondary School, Guizhou of China. In this study, the researcher used a quantitative research method. The study surveyed totally 200 ninth grade of students from four classes in the Xingyi No.1 Secondary School. In this research, for the perception of school climate, the concept of school climate by Haynes, Emmons & Comer (2002) was used and for the satisfaction part, Maslow’s Theory (1943) was used. Firstly, assessed the students’ perception toward the school climate and their level of satisfaction, then tested the relationship between the school climate and their satisfaction. Mean and the Standard Deviations were used to test the students’ perception toward the school climate and their satisfaction; Pearson Product Moment Correlation Coefficient Analysis was used to test the relationship between the school climate and their satisfaction. The results of this study showed that the level of students’ perception toward school climate was high, however, the students had negative perception in some dimensions of the school climate in the Xingyi No.1 Secondary School. And the level of students’ satisfaction was high. According to the Pearson-Moment Correlation Analysis, there was a week positive significant relationship between the grade nine students’ perception toward the school climate and their satisfaction in the school. And students had negative perception in some dimensions of the school climate at the selected school

DnaK Functions as a Central Hub in the E. coli Chaperone Network

Upon emerging from the ribosomal exit tunnel, folding of the polypeptide chain is necessary to form the fully functional protein. In E. coli, correct and efficient protein folding is mainly secured by an organized and complex chaperone system which includes two main principles: The first principle consists of the nascent binding chaperones including trigger factor (TF) and the DnaK/DnaJ system, while the second principle is represented by the downstream GroEL/ES chaperonin system. The identification of ~250 natural GroEL substrates demonstrated that GroEL/ES specifically folds a small group of proteins with complex domain topologies (Kerner et al., 2005) which include some essential proteins. Although the structural, functional and mechanistic aspects of DnaK, the E. coli Hsp70 chaperone, have been extensively studied, a systematic profiling of the natural DnaK substrates is still missing. Moreover, the cooperation between the two main chaperone systems remains to be elucidated. Here we analyzed the central role of DnaK in the bacterial chaperone network and its cooperation with the ribosome-associated chaperone TF and the downstream chaperonin GroEL/GroES using SILAC-based proteomics of DnaK-pulldowns. In parallel, we also analyzed the changes at the global proteome level under conditions of single or combined chaperone deletion. Our measurements show that DnaK normally interacts with at least ~700 newly-synthesized and pre-existent proteins (~30 % of all cytosolic proteins), including ~200 aggregation-prone substrates. Individual deletion of TF or depletion of GroEL/ES at 30 oC-37 oC leads to limited but highly specific changes in the DnaK interactome and in global proteome composition. Specifically, loss of TF results in increased interaction of DnaK with ribosomal and other small, basic proteins, and in a specific defect in the biogenesis of outer membrane -barrel proteins. While deletion of DnaK/DnaJ leads to the degradation or aggregation of ~150 highly DnaK-dependent proteins of large size, massive proteostasis collapse is only observed upon combined deletion of the DnaK system and TF, and is accompanied by extensive aggregation of GroEL substrates and ribosomal proteins. We conclude that DnaK is a central hub in the cytosolic E. coli chaperone network, interfacing with the upstream TF and the downstream chaperonin. These three major chaperone machineries have partially overlapping and non-redundant functions

Statistics of X-ray flares of Sagittarius A*: evidence for solar-like self-organized criticality phenomenon

X-ray flares have routinely been observed from the supermassive black hole, Sagittarius A$^\star$ (Sgr A$^\star$), at our Galactic center. The nature of these flares remains largely unclear, despite of many theoretical models. In this paper, we study the statistical properties of the Sgr A$^\star$ X-ray flares, by fitting the count rate (CR) distribution and the structure function (SF) of the light curve with a Markov Chain Monte Carlo (MCMC) method. With the 3 million second \textit{Chandra} observations accumulated in the Sgr A$^\star$ X-ray Visionary Project, we construct the theoretical light curves through Monte Carlo simulations. We find that the $2-8$ keV X-ray light curve can be decomposed into a quiescent component with a constant count rate of $\sim6\times10^{-3}~$count s$^{-1}$ and a flare component with a power-law fluence distribution $dN/dE\propto E^{-\alpha_{\rm E}}$ with $\alpha_{\rm E}=1.65\pm0.17$. The duration-fluence correlation can also be modelled as a power-law $T\propto E^{\alpha_{\rm ET}}$ with $\alpha_{\rm ET} < 0.55$ ($95\%$ confidence). These statistical properties are consistent with the theoretical prediction of the self-organized criticality (SOC) system with the spatial dimension $S = 3$. We suggest that the X-ray flares represent plasmoid ejections driven by magnetic reconnection (similar to solar flares) in the accretion flow onto the black hole.Comment: to appear in Ap