Order flow dynamics around extreme price changes on an emerging stock market

We study the dynamics of order flows around large intraday price changes using ultra-high-frequency data from the Shenzhen Stock Exchange. We find a significant reversal of price for both intraday price decreases and increases with a permanent price impact. The volatility, the volume of different types of orders, the bid-ask spread, and the volume imbalance increase before the extreme events and decay slowly as a power law, which forms a well-established peak. The volume of buy market orders increases faster and the corresponding peak appears earlier than for sell market orders around positive events, while the volume peak of sell market orders leads buy market orders in the magnitude and time around negative events. When orders are divided into four groups according to their aggressiveness, we find that the behaviors of order volume and order number are similar, except for buy limit orders and canceled orders that the peak of order number postpones two minutes later after the peak of order volume, implying that investors placing large orders are more informed and play a central role in large price fluctuations. We also study the relative rates of different types of orders and find differences in the dynamics of relative rates between buy orders and sell orders and between individual investors and institutional investors. There is evidence showing that institutions behave very differently from individuals and that they have more aggressive strategies. Combing these findings, we conclude that institutional investors are more informed and play a more influential role in driving large price fluctuations.Comment: 22 page

Preferred numbers and the distribution of trade sizes and trading volumes in the Chinese stock market

The distribution of trade sizes and trading volumes are investigated based on the limit order book data of 22 liquid Chinese stocks listed on the Shenzhen Stock Exchange in the whole year 2003. We observe that the size distribution of trades for individual stocks exhibits jumps, which is caused by the number preference of traders when placing orders. We analyze the applicability of the "$q$-Gamma" function for fitting the distribution by the Cram\'{e}r-von Mises criterion. The empirical PDFs of trading volumes at different timescales $\Delta{t}$ ranging from 1 min to 240 min can be well modeled. The applicability of the $q$-Gamma functions for multiple trades is restricted to the transaction numbers $\Delta{n}\leqslant8$. We find that all the PDFs have power-law tails for large volumes. Using careful estimation of the average tail exponents $\alpha$ of the distribution of trade sizes and trading volumes, we get $\alpha>2$, well outside the L{\'e}vy regime.Comment: 7 pages, 5 figures and 4 table

Growth Hormone Therapy Benefits Pituitary Stalk Interruption Syndrome Patients with Short Stature: A Retrospective Study of 75 Han Chinese

Objective. We aim to investigate the long-term benefits of growth hormone (GH) therapy in short stature adolescents and adults with pituitary stalk interruption syndrome (PSIS), which would be beneficial for future clinical applications. Design and Methods. In this study, initial height, final height, total height gain, and GH treatment history were retrospectively investigated in 75 Chinese PSIS patients. We compared height gain between the GH treated cohort and untreated cohort and explored the impact of different GH therapy duration on height gain. Results. For GH treated patients, their final height (SDS) increased from -1.99±1.91 (−6.93~2.80) at bone age (BA) of 11.2 (5.0~17.0) years to -1.47±1.64 (−7.82~1.05) at BA of 16.6 (8.0~18.0) years (P=0.016). And GH treated patients had more height gain than the untreated patients (P<0.05). There was a significant difference between the different GH therapy duration groups (P=0.001): GH 0 versus GH 3, P=0.000; GH 1 versus GH 3, P=0.028; GH 2 versus GH 3, P=0.044. Conclusion. Adult Chinese PSIS patients with short stature benefited the most from at least 12 months of GH therapy. Although patient diagnosis age was lagged behind in the developing countries, GH treatment was still effective for them and resulted in a higher final height and more height gain

Relaxation dynamics of aftershocks after large volatility shocks in the SSEC index

The relaxation dynamics of aftershocks after large volatility shocks are investigated based on two high-frequency data sets of the Shanghai Stock Exchange Composite (SSEC) index. Compared with previous relevant work, we have defined main financial shocks based on large volatilities rather than large crashes. We find that the occurrence rate of aftershocks with the magnitude exceeding a given threshold for both daily volatility (constructed using 1-minute data) and minutely volatility (using intra-minute data) decays as a power law. The power-law relaxation exponent increases with the volatility threshold and is significantly greater than 1. Taking financial volatility as the counterpart of seismic activity, the power-law relaxation in financial volatility deviates remarkably from the Omori law in Geophysics.Comment: 8 EPL pages including 3 figures and 3 table

Fasciolopsis buski (Digenea: Fasciolidae) from China and India may represent distinct taxa based on mitochondrial and nuclear ribosomal DNA sequences

Sequences of primers used to amplify fragments of Fasciolopsis buski mitochondrial genome. (DOCX 17 kb

Elevated Monocyte to High-density Lipoprotein Ratio Is a Risk Factor for New-onset Atrial Fibrillation after Off-pump Coronary Revascularization

Atrial fibrillation (AF) is a common complication of coronary revascularization. Currently, the mechanisms of postoperative AF are unclear. This study was aimed at investigating the risk factors for new-onset AF (NOAF) after coronary revascularization and exploring the early warning effects of clinical inflammatory markers. A retrospective analysis was conducted on 293 patients with unstable angina pectoris who underwent coronary artery revascularization in Beijing Chao-Yang Hospital, Capital Medical University, between April 2018 and June 2021, including 224 patients who underwent coronary artery bypass grafting and 69 patients who underwent one-step hybrid coronary revascularization. Baseline data, clinical data, blood indicators and AF episodes within 7 days after the surgery were collected. Participants were divided into two groups according to whether AF occurred, and the data were analyzed between groups. In addition, multivariate logistic regression was used to explore the independent risk factors for developing AF post coronary revascularization. Aging, a larger left atrial inferior-superior diameter, use of an intra-aortic balloon pump, a greater blood volume transfused during perioperative period and a higher monocyte to high-density lipoprotein ratios on postoperative day 1 were independent risk factors for NOAF after coronary artery surgery

The expression of cytoglobin as a prognostic factor in gliomas: a retrospective analysis of 88 patients

BACKGROUND: Evidence suggests that cytoglobin (Cygb) may function as a tumor suppressor gene. METHODS: We immunohistochemically evaluated the expression of Cygb, phosphatidylinositol-3 kinase (PI-3K), phosphorylated (p)-Akt, Interleukin-6 (IL-6), tumor necrosis factor-α (TNFα) and vascular endothelial growth factor (VEGF) in 88 patients with 41 high-grade gliomas and 47 low-grade gliomas. Intratumoral microvessel density (IMD) was also determined and associated with clinicopathological factors. RESULTS: Low expression of Cygb was significantly associated with the higher histological grading and tumor recurrence. A significant negative correlation emerged between Cygb expression and PI3K, p-Akt, IL-6, TNFα or VEGF expression. Cygb expression was negatively correlated with IMD. There was a positive correlation between PI3K, p-Akt, IL-6, TNFα and VEGF expression with IMD.High histologic grade, tumor recurrence, decreased Cygb expression, increased PI3K expression, increased p-Akt expression and increased VEGF expression correlated with patients’ overall survival in univariate analysis. However, only histological grading and Cygb expression exhibited a relationship with survival of patients as independent prognostic factors of glioma by multivariate analysis. CONCLUSIONS: Cygb loss may contribute to tumor recurrence and a worse prognosis in gliomas. Cygb may serve as an independent predictive factor for prognosis of glioma patients

Preparation of intergrown P/O-type biphasic layered oxides as high-performance cathodes for sodium ion batteries

This study reports on the solid-state synthesis and characterization of novel quaternary P/O intergrown biphasic Na$_{0.8}$MnyNi$_{0.8-y}$Fe$_{0.1}$Ti$_{0.1}$O$_{2}$ (y = 0.6, 0.55, 0.5, 0.45) cathode materials. Electrochemical tests reveal superior performance of the P/O biphasic materials in a sodium ion battery compared to the single P2 or O3 phases, proving the beneficial effect of the intergrowth of P2 and O3 materials. The nature of the P/O interface was studied by transmission electron microscopy. The analysis shows a semi-coherent interface grown along the a/b and c axes with local differences in the transition metal concentration along the interface between the two phases. EDX and EELS characterization revealed a charge compensation mechanism across the phase boundary based on variation of the transition element distribution, balancing the different sodium contents in the P and O phases. The results reported in this study provide a better understanding of P/O biphasic materials

A New Type of Quartz Smog Chamber : Design and Characterization

Publisher Copyright: ©Since the 1960s, many indoor and outdoor smog chambers have been developed worldwide. However, most of them are made of Teflon films, which have relatively high background contaminations due to the wall effect. We developed the world's first medium-size quartz chamber (10 m(3)), which is jointed with 32 pieces of 5 mm thick polished quartz glasses and a stainless-steel frame. Characterizations show that this chamber exhibits excellent performance in terms of relative humidity (RH) (2-80%) and temperature (15-30 +/- 1 degrees C) control, mixing efficiency of the reactants (6-8 min), light transmittance (>90% above 290 nm), and wall loss of pollutants. The wall loss rates of the gas-phase pollutants are on the order of 10(-4) min(-1) at 298 K under dry conditions. It is 0.08 h(-1) for 100-500 nm particles, significantly lower than those of Teflon chambers. The photolysis rate of NO2 (J(NO2)) is automatically adjustable to simulate the diurnal variation of solar irradiation from 0 to 0.40 min(-1). The inner surface of the chamber can be repeatedly washed with deionized water, resulting in low background contaminations. Both experiments (toluene-NOx and alpha-pinene-ozone systems) and box model demonstrate that this new quartz chamber can provide high-quality data for investigating SOA and O-3 formation in the atmosphere.Peer reviewe