On thermal radiation of de Sitter space in the semiclassical Jackiw-Teitelboim model

In general, the Gibbons-Hawking temperature based on the Euclidean functional approach shows that de Sitter space in the Bunch-Davies vacuum is globally thermal. In the exactly soluble semiclassical Jackiw-Teitelboim model, we investigate thermal property of de Sitter space by taking into account the quantum back reaction of the geometry. The temperature of de Sitter space in the Bunch-Davies vacuum is found to vanish. In case of a certain quantum state breaking the de Sitter symmetry, de Sitter space can be made thermally exited; however, in this case the dilaton singularity cannot be avoided. Consequently, in the Jackiw-Teitelboim model the temperature of de Sitter space in the Bunch-Davies vacuum turns out to be zero and the Bunch-Davies vacuum is found to be the only physical vacuum without any naked singularities.Comment: 14 pages, 1 figure, comments and references adde

policy and managerial implications

Thesis(Master) --KDI School:Master of Development Policy,2017Countries are in transition to a low-carbon and climate-resilient economy to achieve sustainable development. One of the important ways into the sustainable growth path is carbon reduction, which is especially true in Korea with high proportion of road vehicle. Therefore, this paper investigates bicycle sharing economy as an emerging and alternative mode of transportation service and provides potential managerial and policy implications. Since bicycle sharing economy is still at an early stage of introduction as a transportation mode, the government is promoting public bicycle sharing to encourage bike riding as a substitute for private car. This study analyzed the current status of bicycle sharing programs through survey which was distributed randomly to users and non-users across the country. Using factor analysis, the overall attitudes such as satisfaction and loyalty for the existing users, and intention to use and expected satisfaction for the potential users were examined in relation with utility factors. The findings of the study could be applicable to the future direction of sharing economy as a means to follow sustainable development of society.I. Introduction II. Literature Reviews III. Theoretical Background IV. Hypotheses Developments V. Methodology VI. Data Analysis VII. ConclusionOutstandingmasterpublishedHwajin KIM

Unruh effect of nonlocal field theories with a minimal length

The nonlocal field theory commonly requires a minimal length, and so it appears to formulate the nonlocal theory in terms of the doubly special relativity which makes the speed of light and the minimal length invariant simultaneously. We set up a generic nonlocal model having the same set of solutions as the local theory but allowing Lorentz violations due to the minimal length. It is exactly corresponding to the model with the modified dispersion relation in the doubly special relativity. For this model, we calculate the modified Wightman function and the rate of response function by using the Unruh-DeWitt detector method. It turns out that the Unruh effect should be corrected by the minimal length related to the nonlocality in the regime of the doubly special relativity. However, for the Lorentz-invariant limit, it is shown that the Wightman function and the Unruh effect remain the same as those of the local theory.Comment: 16 pages, version to appear in PL

Photochemical Organonitrate Formation in Wet Aerosols

Water is the most abundant component of atmospheric fine aerosol. However, despite rapid progress, multiphase chemistry involving wet aerosols is still poorly understood. In this work, we report results from smog chamber photooxidation of glyoxal and OH &ndash; containing ammonium sulfate or sulfuric acid particles in the presence of NOx and O3 at high and low relative humidity. Particles were analyzed using ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). During the 3 hour irradiation, OH oxidation products of glyoxal that are also produced in dilute aqueous solutions (e.g., oxalic acids and tartaric acids) were formed in both ammonium sulfate (AS) aerosols and sulfuric acid (SA) aerosols. However, the major products were organonitrogens (CHNO), organosulfates (CHOS), and organonitrogen-sulfates (CHNOS). These were also the dominant products formed in the dark chamber indicating non-radical formation. In the humid chamber (> 70 % RH), two main products for both AS and SA aerosols were organonitrates, which appeared at m/z&minus; 147 and 226. They were formed in the aqueous phase via non-radical reactions of glyoxal and nitric acid, and their formation was enhanced by photochemistry because of the photochemical formation of nitric acid via reactions of peroxy radicals, NOx and OH during the irradiation.</html

Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy

AIM: To study the contribution of tonicity response element binding protein (TonEBP) in retinal ganglion cell (RGC) death of diabetic retinopathy (DR). METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin (STZ). Control mice received vehicle (phosphate -buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of TonEBP and aldose reductase (AR) were examined. RESULTS: The TonEBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase (TdT) -mediated dUTP nick end labeling (TUNEL) -positive signals co -localized with TonEBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls. CONCLUSION: The present data show that AR and TonEBP are upregulated in the DR and TonEBP may contribute to apoptosis of RGC in the DR.close2

CLASP promotes microtubule rescue by recruiting tubulin dimers to the microtubule

Spatial regulation of microtubule (MT) dynamics contributes to cell polarity and cell division. MT rescue, in which a MT stops shrinking and reinitiates growth, is the least understood aspect of MT dynamics. Cytoplasmic Linker Associated Proteins (CLASPs) are a conserved class of MT-associated proteins that contribute to MT stabilization and rescue in vivo. We show here that the Schizosaccharomyces pombe CLASP, Cls1p, is a homodimer that binds an αβ-tubulin heterodimer through conserved TOG-like domains. In vitro, CLASP increases MT rescue frequency, decreases MT catastrophe frequency, and moderately decreases MT disassembly rate. CLASP binds stably to the MT lattice, recruits tubulin, and locally promotes rescues. Mutations in the CLASP TOG domains demonstrate that tubulin binding is critical for its rescue activity. We propose a mechanism for rescue in which CLASP-tubulin dimer complexes bind along the MT lattice and reverse MT depolymerization with their bound tubulin dimer

CLASP promotes microtubule rescue by recruiting tubulin dimers to the microtubule

Spatial regulation of microtubule (MT) dynamics contributes to cell polarity and cell division. MT rescue, in which a MT stops shrinking and reinitiates growth, is the least understood aspect of MT dynamics. Cytoplasmic Linker Associated Proteins (CLASPs) are a conserved class of MT-associated proteins that contribute to MT stabilization and rescue in vivo. We show here that the Schizosaccharomyces pombe CLASP, Cls1p, is a homodimer that binds an αβ-tubulin heterodimer through conserved TOG-like domains. In vitro, CLASP increases MT rescue frequency, decreases MT catastrophe frequency, and moderately decreases MT disassembly rate. CLASP binds stably to the MT lattice, recruits tubulin, and locally promotes rescues. Mutations in the CLASP TOG domains demonstrate that tubulin binding is critical for its rescue activity. We propose a mechanism for rescue in which CLASP-tubulin dimer complexes bind along the MT lattice and reverse MT depolymerization with their bound tubulin dimer