Market Volatility around U.S. Presidential Election (1928-2016): The Role of Political Uncertainty

This paper investigates the changes in market volatility around the United States presidential elections and inaugurations between the period of 1928 and 2016 during selected event windows: (-10, -1) vs. (+1, +10), (-20, -1) vs. (+1, +20), … (-90, -1) vs. (+1, +90), respectively. To isolate the corresponding impact of different types of political uncertainty, market volatility is examined under three partitions: magnitude of surprise in voting results, incumbency, and change in ruling party. The result indicates that the market volatility is more willing to settle down after an election with new president or a change in ruling party, mainly due to the comparatively higher volatility induced by such political events during the pre-election window. The results have implications for both individual and institutional investors who are exposed towards volatility risk

Gravity Effects on Information Filtering and Network Evolving

In this paper, based on the gravity principle of classical physics, we propose a tunable gravity-based model, which considers tag usage pattern to weigh both the mass and distance of network nodes. We then apply this model in solving the problems of information filtering and network evolving. Experimental results on two real-world data sets, \emph{Del.icio.us} and \emph{MovieLens}, show that it can not only enhance the algorithmic performance, but can also better characterize the properties of real networks. This work may shed some light on the in-depth understanding of the effect of gravity model

Dual mTOR/PI3K inhibition limits PI3K-dependent pathways activated upon mTOR inhibition in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of kidney cysts leading to kidney failure in adulthood. Inhibition of mammalian target of rapamycin (mTOR) slows polycystic kidney disease (PKD) progression in animal models, but randomized controlled trials failed to prove efficacy of mTOR inhibitor treatment. Here, we demonstrate that treatment with mTOR inhibitors result in the removal of negative feedback loops and up-regulates pro-proliferative phosphatidylinositol 3-kinase (PI3K)-Akt and PI3K-extracellular signal-regulated kinase (ERK) signaling in rat and mouse PKD models. Dual mTOR/PI3K inhibition with NVP-BEZ235 abrogated these pro-proliferative signals and normalized kidney morphology and function by blocking proliferation and fibrosis. Our findings suggest that multi-target PI3K/mTOR inhibition may represent a potential treatment for ADPKD

Interfacial microstructure and strengthening mechanism of dissimilar laser al/steel joint via a porous high entropy alloy coating

Publisher Copyright: © 2023 The Authors This work was supported by the National Natural Science Foundation of China (No. 52275155) and Class III Peak Discipline of Shanghai-Materials Science and Engineering. JPO acknowledges funding by national funds from FCT-Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nano-modelling and Nanofabrication-i3N.A porous high entropy alloy (HEA) coating was prepared on a steel surface by vacuum sintering. The coating was then used as a transition layer during dissimilar laser joining of Al to steel. Compared with the uncoated laser joints, the liquid alloy spread and infiltrated into the porous structure, the contact angle of the weld reduced from 65.8° to 56.7°, and the brazed width increased from 5.1 mm to 5.9 mm, which improved the wettability and spreadability of the molten filler wire on the substrate. In the case of the uncoated steel, the fusion zone/steel interfacial microstructure consisted of laminated Al7·2Fe1·8Si and Fe(Al,Si)3, while it changed to a composite-like structure containing a soft HEA skeleton and hard IMCs which included Al7·2Fe1·8Si, Al3Ni, and (Al,Si)2Cr. In addition, due to the sluggish diffusion effect of HEAs, a layer of gradient nanocrystalline composed of Al7·2Fe1·8Si was generated, which significantly strengthened the dissimilar laser joints with improvements in both the fracture load (∼26.5%) and the displacement (∼101.8%). The fracture mode changed from brittle to ductile failure when the porous HEA coating was applied, with fracture propagating through the HEA skeleton. This work provides a novel solution for the strengthening of hard-to-join dissimilar combinations.publishersversionpublishe