Dynamic Voids Surrounded by Shocked Conventional Polytropic Gas Envelopes

With proper physical mechanisms of energy and momentum input from around the centre of a self-gravitating polytropic gas sphere, a central spherical "void" or "cavity" or "bubble" of very much less mass contents may emerge and then dynamically expand into a variety of surrounding more massive gas envelopes with or without shocks. We explore self-similar evolution of a self-gravitating polytropic hydrodynamic flow of spherical symmetry with such an expanding "void" embedded around the center. The void boundary supporting a massive envelope represents a pressure-balanced contact discontinuity where drastic changes in mass density and temperature occur. We obtain numerical void solutions that can cross the sonic critical surface either smoothly or by shocks. Using the conventional polytropic equation of state, we construct global void solutions with shocks travelling into various envelopes including static polytropic sphere, outflow, inflow, breeze and contraction types. In the context of supernovae, we discuss the possible scenario of separating a central collapsing compact object from an outgoing gas envelope with a powerful void in dynamic expansion. Initially, a central bubble is carved out by an extremely powerful neutrinosphere. After the escape of neutrinos during the decoupling, the strong electromagnetic radiation field and/or electron-positron pair plasma continue to drive the cavity expansion. In a self-similar dynamic evolution, the pressure across the contact discontinuity decreases with time to a negligible level for a sufficiently long lapse and eventually, the gas envelope continues to expand by inertia. We describe model cases of polytropic index $\gamma=4/3-\epsilon$ with $\epsilon>0$ and discuss pertinent requirements to justify our proposed scenario.Comment: 20 pages, 12 Figures. Accepted for publication in MNRA

Quantum algorithm for association rules mining

Association rules mining (ARM) is one of the most important problems in knowledge discovery and data mining. Given a transaction database that has a large number of transactions and items, the task of ARM is to acquire consumption habits of customers by discovering the relationships between itemsets (sets of items). In this paper, we address ARM in the quantum settings and propose a quantum algorithm for the key part of ARM, finding out frequent itemsets from the candidate itemsets and acquiring their supports. Specifically, for the case in which there are $M_f^{(k)}$ frequent $k$-itemsets in the $M_c^{(k)}$ candidate $k$-itemsets ($M_f^{(k)} \leq M_c^{(k)}$), our algorithm can efficiently mine these frequent $k$-itemsets and estimate their supports by using parallel amplitude estimation and amplitude amplification with complexity $\mathcal{O}(\frac{k\sqrt{M_c^{(k)}M_f^{(k)}}}{\epsilon})$, where $\epsilon$ is the error for estimating the supports. Compared with the classical counterpart, classical sampling-based algorithm, whose complexity is $\mathcal{O}(\frac{kM_c^{(k)}}{\epsilon^2})$, our quantum algorithm quadratically improves the dependence on both $\epsilon$ and $M_c^{(k)}$ in the best case when $M_f^{(k)}\ll M_c^{(k)}$ and on $\epsilon$ alone in the worst case when $M_f^{(k)}\approx M_c^{(k)}$.Comment: 8 page

Guanxi, Economic Policy Uncertainty and Corporate Social Responsibility

Masteroppgave(MSc) in Master of Science in Finance - Handelshøyskolen BI, 2022Informal systems can have a significant impact on corporate behavior, and 'Guanxi' is part of the informal system that can have a significant impact on corporate social responsibility. Based on the data of A-share listed companies in China, we take the relationship between local officials and corporate executives as an entry point to study the impact of Guanxi on Corporate Social Responsibility in the context of China's Economic Policy Uncertainty. It is found that Guanxi has a positive effect on CSR, and this effect is more significant when Economic Policy Uncertainty is low. Further research finds that there is a benefit swap effect between local officials and corporate executives, which is more pronounced when Economic Policy Uncertainty is high, while the heterogeneity study also finds that state-owned enterprises have stronger incentives to exploit hometown relationships compared to non-state-owned enterprises, especially when Economic Policy Uncertainty is low. The research in this paper facilitates the understanding of the mechanism of the influence of Guanxi on corporate behavior in the informal system and provides a new perspective for the study of corporate social responsibility

FSD-C10: A more promising novel ROCK inhibitor than Fasudil for treatment of CNS autoimmunity.

Rho-Rho kinase (Rho-ROCK) triggers an intracellular signalling cascade that regulates cell survival, death, adhesion, migration, neurite outgrowth and retraction and influences the generation and development of several neurological disorders. Although Fasudil, a ROCK inhibitor, effectively suppressed encephalomyelitis (EAE), certain side effects may limit its clinical use. A novel and efficient ROCK inhibitor, FSD-C10, has been explored. In the present study, we present chemical synthesis and structure of FSD-C10, as well as the relationship between compound concentration and ROCK inhibition. We compared the inhibitory efficiency of ROCKI and ROCK II, the cell cytotoxicity, neurite outgrowth and dendritic formation, neurotrophic factors and vasodilation between Fasudil and FSD-C10. The results demonstrated that FSD-C10, like Fasudil, induced neurite outgrowth of neurons and dendritic formation of BV-2 microglia and enhanced the production of neurotrophic factor brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3). However, the cell cytotoxicity and vasodilation of FSD-C10 were relatively small compared with Fasudil. Although Fasudil inhibited both ROCK I and ROCK II, FSD-C10 more selectively suppressed ROCK II, but not ROCK I, which may be related to vasodilation insensitivity and animal mortality. Thus, FSD-C10 may be a safer and more promising novel ROCK inhibitor than Fasudil for the treatment of several neurological disorders

South China Sea surface water evolution over the last 12 Myr: A south-north comparison from Ocean Drilling Program Sites 1143 and 1146

Planktonic foraminifera (PF) from Ocean Drilling Program (ODP) Sites 1143 and 1146 in the southern and northern South China Sea (SCS), respectively, were quantitatively analyzed in order to reconstruct the sea-surface environment over the last 12 Myr. The observed decrease in deep-dwelling PF species after ∼10 Ma at both sites is interpreted to reflect a depression of the upper water thermocline, corresponding to the closure of the Indonesian Seaway around 11-9 Ma. This upper water column structure implies the intensification of equatorial Pacific warm currents and the initial formation of the western Pacific "warm pool" (WPWP) during the early Late Miocene. The consistent pattern of south-north thermocline evolution and the synchronous disappearance of Globoquadrina dehiscens (9.8 Ma) at both Sites 1143 and 1146 together imply that the entire SCS was likely under the influence of the newly developed WPWP at ∼10 Ma. After ∼8 Ma, sea-surface temperatures and thermocline variations evolved differently between the southern and northern SCS. The total deep-dwelling PF fauna at Site 1143 decreased gradually in abundance from 6.6 to 2 Ma, indicating a deepening of the thermocline in the southern SCS. In contrast, deep-dwelling PF species increased in abundance from 3.1 to 2 Ma at Site 1146, reflecting a shoaling of the thermocline in the northern SCS. This south-north contrast reflects two major environmental regimes: (1) the southern SCS, which has mainly been under the influence of the WPWP since the late Late Miocene, and (2) the northern SCS, where effects of the east Asian winter monsoon have prevailed, especially since the Late Pliocene. Estimate of past sea-surface temperatures (SSTs) at Site 1143 suggests a relatively stable and warm environment in the southern SCS since about 2.5 Ma, with an increased influence of warm subsurface waters after the mid-Pleistocene transition (1.2-0.9 Ma). In the northern SCS, however, a gradual decrease in winter SST recorded at Site 1146 over the last 4 Myr records east Asian monsoon evolution, especially the enhancement of the east Asian winter monsoon between 3.1 and 2 Ma. Copyright 2004 by the American Geophysical Union.Baohua Li, Jiliang Wang, Baoqi Huang, Qianyu Li, Zhimin Jian, Quanhong Zhao, Xin Su and Pinxian Wan