Dynamic structure of stock communities: A comparative study between stock returns and turnover rates

The detection of community structure in stock market is of theoretical and practical significance for the study of financial dynamics and portfolio risk estimation. We here study the community structures in Chinese stock markets from the aspects of both price returns and turnover rates, by using a combination of the PMFG and infomap methods based on a distance matrix. We find that a few of the largest communities are composed of certain specific industry or conceptional sectors and the correlation inside a sector is generally larger than the correlation between different sectors. In comparison with returns, the community structure for turnover rates is more complex and the sector effect is relatively weaker. The financial dynamics is further studied by analyzing the community structures over five sub-periods. Sectors like banks, real estate, health care and New Shanghai take turns to compose a few of the largest communities for both returns and turnover rates in different sub-periods. Several specific sectors appear in the communities with different rank orders for the two time series even in the same sub-period. A comparison between the evolution of prices and turnover rates of stocks from these sectors is conducted to better understand their differences. We find that stock prices only had large changes around some important events while turnover rates surged after each of these events relevant to specific sectors, which may offer a possible explanation for the complexity of stock communities for turnover rates

Two variants on T2DM susceptible gene HHEX are associated with CRC risk in a Chinese population

Increasing amounts of evidence has demonstrated that T2DM (Type 2 Diabetes Mellitus) patients have increased susceptibility to CRC (colorectal cancer). As HHEX is a recognized susceptibility gene in T2DM, this work was focused on two SNPs in HHEX, rs1111875 and rs7923837, to study their association with CRC. T2DM patients without CRC (T2DM-only, n=300), T2DM with CRC (T2DM/CRC, n=135), cancer-free controls (Control, n=570), and CRC without T2DM (CRC-only, n=642) cases were enrolled. DNA samples were extracted from the peripheral blood leukocytes of the patients and sequenced by direct sequencing. The χ(2) test was used to compare categorical data. We found that in T2DM patients, rs1111875 but not the rs7923837 in HHEX gene was associated with the occurrence of CRC (p= 0.006). for rs1111875, TC/CC patients had an increased risk of CRC (p=0.019, OR=1.592, 95%CI=1.046-2.423). Moreover, our results also indicated that the two variants of HEEX gene could be risk factors for CRC in general population, independent on T2DM (p< 0.001 for rs1111875, p=0.001 for rs7923837). For rs1111875, increased risk of CRC was observed in TC or TC/CC than CC individuals (p<0.001, OR= 1.780, 95%CI= 1.385-2.287; p<0.001, OR= 1.695, 95%CI= 1.335-2.152). For rs7923837, increased CRC risk was observed in AG, GG, and AG/GG than AA individuals (p< 0.001, OR= 1.520, 95%CI= 1.200-1.924; p=0.036, OR= 1.739, 95%CI= 0.989-3.058; p< 0.001, OR= 1.540, 95%CI= 1.225-1.936). This finding highlights the potentially functional alteration with HHEX rs1111875 and rs7923837 polymorphisms may increase CRC susceptibility. Risk effects and the functional impact of these polymorphisms need further validation

Strength characteristics and failure behavior of ubiquitous-joint rock-like specimens under compressive-shear stress: experimental study and digital speckle correlation method

In nature, rock mass is subjected to compression-shear effect, so it is very important to study the failure mode and mechanical properties of fractured rock mass under compression-shear effect. In order to study the influence of joint inclination on strength characteristics and failure modes of rock mass under different compression-shear angles, a series of compression-shear tests were carried out. The specimens are made of a certain proportion of fine sand, cement and water. The joints are prefabricated by inserting mica sheets and the inclination angle of joints is 0°, 15°, 30°, 45°, 60°, 75°, 90°. Digital speckle correlation method is used to analyze the strain field of the specimen during the whole loading process. The specimens are speckled on the opposite side before the experiment. In the experiment, the front and back sides of the specimen are monitored by the camera, and the images are analyzed after the experiment. The result shows that: 1) The peak shear strength of specimens mainly increases with the increase of joint inclination angle; 2) The weakening degree of shear strength caused by joint inclination angle of specimens tends to increase as the compression-stress ratio increases; and 3) The failure modes can be classified into four types: coplanar shear failure mode, inclined shear failure mode, quasi-complete shear failure mode and step shear failure mode. The digital speckle strain images better prove the failure modes obtained from the experiment

Attenuation of transcriptional bursting in mRNA transport

Due to the stochastic nature of biochemical processes, the copy number of any given type of molecule inside a living cell often exhibits large temporal fluctuations. Here, we develop analytic methods to investigate how the noise arising from a bursting input is reshaped by a transport reaction which is either linear or of the Michaelis-Menten type. A slow transport rate smoothes out fluctuations at the output end and minimizes the impact of bursting on the downstream cellular activities. In the context of gene expression in eukaryotic cells, our results indicate that transcriptional bursting can be substantially attenuated by the transport of mRNA from nucleus to cytoplasm. Saturation of the transport mediators or nuclear pores contributes further to the noise reduction. We suggest that the mRNA transport should be taken into account in the interpretation of relevant experimental data on transcriptional bursting.Comment: 18 pages, 3 figure

Effect of dark matter on shadows and rings of a brane-world black hole illuminated by various accretions

In this paper, by taking the accretions into account, the observational shadows and rings casted by the Brane-world black hole are numerically investigated when the observer located at the cosmological horizon. The results here show that the radius $r_p$ of photon sphere increased with cosmological parameter $\alpha$ and dark matter parameter $\beta$, while the impact parameter $b_p$ decreased with $\alpha$ and increased with $\beta$. For the thin-disk accretion, it turns out that the total observed intensity are mainly composed of the direct emission, while lensing ring and photon ring only contribute a small contribution and a negligible contribution, respectively. And, we find that shadow and rings exhibit some different and interesting features when the disk located at different positions. For the static and infalling spherical accretions, it is obvious that the size of shadow is always the same for both accretions, which means that shadow is only related to the geometry of space time in this case. The luminosity of shadow and photon sphere are closely related to the Doppler effect and the emissivity per unit volume $j({\nu_e})$. In addition, the influence of dark matter and cosmological constant on observed intensity of shadows and rings are carefully emphasized throughout of this paper. Finally, we obtained the burring images of shadows and rings by using the nominal resolution of the Event Horizon Telescope, and studied the upper limits on the X-clod dark matter parameter $\beta$ with the aid of the data of the shadow of M87.Comment: 66figures, 4tables, 26pages,accepted by SCIENCE CHINA Physics, Mechanics & Astronomy,202

Octenylsuccinate quinoa starch granule-stabilized pickering emulsion gels: preparation, microstructure and gelling mechanism

The development of emulsion gels has attracted increasing interests due to their potential applications as oil structuring templates and release-controlled carriers for sensitive lipid-soluble bioactive compounds. This work aimed to elucidate the importance of changing the degree of substitution (DS, 0.0072–0.0286) and oil volume fraction (Φ, 10–90%) to achieve octenylsuccinate (OS) quinoa starch granule-based Pickering emulsion gels. The gelation process, droplet size distribution, rheological properties and microstructure of Pickering emulsion gels formed at various DS and Φ values were evaluated. Octenylsuccinylation did not change the morphology or the granule size of quinoa starch but significantly increased the contact angle from 36.2° to 68.7°. OS quinoa starch granule-stabilized Pickering emulsion gels were formed at a DS of 0.0286 with Φ values ranging from 50 to 70%. At the Φ value of 70%, increasing DS progressively increased the apparent viscosity (η) and storage modulus (G′) of the emulsions as a result of the adsorption of more OS quinoa starch granules at the oil/water interface. Both η and G′ showed an increasing trend as a function of Φ (50–70%) at a DS value of 0.0286, and this was closely related to the microstructure of the formed emulsion gels. The network of OS quinoa starch-based Pickering emulsion gels at high Φ values (e.g., 60% and 70%) was mainly composed of compact “aggregated” oil droplets, which was largely attributed to the inter-droplet interactions. These results are of great help in understanding the gelling mechanism and the development of starch granule-based Pickering emulsion gels

Linezolid and Rifampicin Combination to Combat cfr-Positive Multidrug-Resistant MRSA in Murine Models of Bacteremia and Skin and Skin Structure Infection.

Linezolid resistance mediated by the cfr gene in MRSA represents a global concern. We investigated relevant phenotype differences between cfr-positive and -negative MRSA that contribute to pathogenesis, and the efficacy of linezolid-based combination therapies in murine models of bacteremia and skin and skin structure infection (SSSI). As a group, cfr-positive MRSA exhibited significantly reduced susceptibilities to the host defense peptides tPMPs, human neutrophil peptide-1 (hNP-1), and cathelicidin LL-37 (P &lt; 0.01). In addition, increased binding to fibronectin (FN) and endothelial cells paralleled robust biofilm formation in cfr-positive vs. -negative MRSA. In vitro phenotypes of cfr-positive MRSA translated into poor outcomes of linezolid monotherapy in vivo in murine bacteremia and SSSI models. Importantly, rifampicin showed synergistic activity as a combinatorial partner with linezolid, and the EC50 of linezolid decreased 6-fold in the presence of rifampicin. Furthermore, this combination therapy displayed efficacy against cfr-positive MRSA at clinically relevant doses. Altogether, these data suggest that the use of linezolid in combination with rifampicin poses a viable therapeutic alternative for bacteremia and SSSI caused by cfr-positive multidrug resistant MRSA

Scaling in directed dynamical small-world networks with random responses

A dynamical model of small-world network, with directed links which describe various correlations in social and natural phenomena, is presented. Random responses of every site to the imput message are introduced to simulate real systems. The interplay of these ingredients results in collective dynamical evolution of a spin-like variable S(t) of the whole network. In the present model, global average spreading length \langel L >_s and average spreading time _s are found to scale as p^-\alpha ln N with different exponents. Meanwhile, S behaves in a duple scaling form for N>>N^*: S ~ f(p^-\beta q^\gamma t'_sc), where p and q are rewiring and external parameters, \alpha, \beta, \gamma and f(t'_sc) are scaling exponents and universal functions, respectively. Possible applications of the model are discussed.Comment: 4 pages, 6 Figure