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Observations indicate that the distributions of stock returns in financial markets usually do not conform to normal distributions, but rather exhibit characteristics of high peaks, fat tails and biases. In this work, we assume that the effects of events or information on prices obey normal distribution, while financial markets often overreact or underreact to events or information, resulting in non normal distributions of stock returns. Based on the above assumptions, we for the first time propose a reaction function for a financial market reacting to events or information, and a model based on it to describe the distribution of real stock returns. Our analysis of the returns of China Securities Index 300 (CSI 300), the Standard & Poor’s 500 Index (SPX or S &P 500) and the Nikkei 225 Index (N225) at different time scales shows that financial markets often underreact to events or information with minor impacts, overreact to events or information with relatively significant impacts, and react slightly stronger to positive events or information than to negative ones. In addition, differences in financial markets and time scales of returns can also affect the shapes of the reaction functions.

We point out that the electroweak fine-tuning problem in the supersymmetric Standard Models (SSMs) is mainly due to the high energy definition of the fine-tuning measure. We propose super-natural supersymmetry which has an order one high energy fine-tuning measure automatically. The key point is that all the mass parameters in the SSMs arise from a single supersymmetry breaking parameter. In this paper, we show that there is no supersymmetry electroweak fine-tuning problem explicitly in the Minimal SSM (MSSM) with no-scale supergravity and Giudice-Masiero (GM) mechanism. We demonstrate that the Z-boson mass, the supersymmteric Higgs mixing parameter μ at the unification scale, and the sparticle spectrum can be given as functions of the universal gaugino mass M1/2. Because the light stau is the lightest supersymmetric particle (LSP) in the no-scale MSSM, to preserve R parity, we introduce a non-thermally generated axino as the LSP dark matter candidate. We estimate the lifetime of the light stau by calculating its 2-body and 3-body decays to the LSP axino for several values of axion decay constant fa, and find that the light stau has a lifetime ττ-1 in [10-4,100] s for an fa range [109,1012] GeV. We show that our next to the LSP stau solutions are consistent with all the current experimental constraints, including the sparticle mass bounds, B-physics bounds, Higgs mass, cosmological bounds, and the bounds on long-lived charge particles at the LHC. [ABSTRACT FROM AUTHOR]

Cellular collective motion in confluent epithelial monolayers is involved in many processes such as embryo development, carcinoma invasion, and wound healing. The development of new chemical strategies to achieve large-scale control of cells’ collective motion is essential for biomedical applications. Here a series of DNA nanostructures with different dimensions were synthesized and their influences on cells’ collective migration and packing behaviors in epithelial monolayers were investigated. We found that the framed DNA nanoassemblies effectively reduced the cells’ speed by increasing the rigidity of cells, while the lipid-DNA micelles had a more pronounced effect on cells’ projection area and shape factor. These DNA nanostructures all significantly enhanced the dependence of cells’ speed on their shape factor. Our results indicate that cells’ mobility in the monolayer can be manipulated by chemical intercellular interactions without any genetic intervention. This may open a new chemical strategy for tissue engineering and tumor therapy.