84 research outputs found
Fault protection method of single-phase break for distribution network considering the influence of neutral grounding modes
Study on Informational Transaction and Its Effect on China's Stock Index Futures Market
Information is one of the important factors that influence the behavior of investors and then have an effect on the price of the risky assets in the market. Firstly, the new procedure developed by Easley et al. (2011) is used to estimate the Volume-Synchronized Probability of Informed Trading (VPIN) of the Chinese stock index futures market. Then VPIN for special scenarios is depicted. As a result, we find that the future contracts generally have a larger number of information transactions. We also find that, for particular scenarios, the probability of informed trading in the market has obvious exceptions. The larger proportion of informed trader is, the higher the volatility of the price is
In-Orbit Instrument Performance Study and Calibration for POLAR Polarization Measurements
POLAR is a compact space-borne detector designed to perform reliable
measurements of the polarization for transient sources like Gamma-Ray Bursts in
the energy range 50-500keV. The instrument works based on the Compton
Scattering principle with the plastic scintillators as the main detection
material along with the multi-anode photomultiplier tube. POLAR has been
launched successfully onboard the Chinese space laboratory TG-2 on 15th
September, 2016. In order to reliably reconstruct the polarization information
a highly detailed understanding of the instrument is required for both data
analysis and Monte Carlo studies. For this purpose a full study of the in-orbit
performance was performed in order to obtain the instrument calibration
parameters such as noise, pedestal, gain nonlinearity of the electronics,
threshold, crosstalk and gain, as well as the effect of temperature on the
above parameters. Furthermore the relationship between gain and high voltage of
the multi-anode photomultiplier tube has been studied and the errors on all
measurement values are presented. Finally the typical systematic error on
polarization measurements of Gamma-Ray Bursts due to the measurement error of
the calibration parameters are estimated using Monte Carlo simulations.Comment: 43 pages, 30 figures, 1 table; Preprint accepted by NIM
Co-creation using crowdsourcing to promote PrEP adherence in China: study protocol for a stepped-wedge randomized controlled trial.
BACKGROUND: Adherent pre-exposure prophylaxis (PrEP) uptake can prevent HIV infections. Despite the high HIV incidence, Chinese key populations have low PrEP uptake and adherence. New interventions are needed to increase PrEP adherence among key populations in China. Co-creation methods are helpful to solicit ideas from the community to solve public health problems. The study protocol aims to describe the design of a stepped-wedge trial and to evaluate the efficacy of co-created interventions to facilitate PrEP adherence among key populations in China. METHODS: The study will develop intervention packages to facilitate PrEP adherence among Chinese key populations using co-creation methods. The study will then evaluate the efficacy of the co-created intervention packages using a stepped-wedge randomized controlled trial. This four-phased closed cohort stepped-wedge design will have four clusters. Each cluster will start intervention at three-month intervals. Seven hundred participants who initiated PrEP will be recruited. Participants will be randomized to the clusters using block randomization. The intervention condition includes receiving co-created interventions in addition to standard of care. The control condition is the standard of care that includes routine clinical assessment every 3 months. All participants will also receive an online follow-up survey every 3 months to record medication adherence and will be encouraged to use a WeChat mini-app for sexual and mental health education throughout the study. The primary outcomes are PrEP adherence and retention in PrEP care throughout the study period. We will examine a hypothesis that a co-created intervention can facilitate PrEP adherence. Generalized linear mixed models will be used for the primary outcome analysis. DISCUSSION: Developing PrEP adherence interventions in China faces barriers including suboptimal PrEP uptake among key populations, the lack of effective PrEP service delivery models, and insufficient community engagement in PrEP initiatives. Our study design addresses these obstacles by using co-creation to generate social media-based intervention materials and embedding the study design in the local healthcare system. The study outcomes may have implications for policy and intervention practices among CBOs and the medical system to facilitate PrEP adherence among key populations. TRIAL REGISTRATION: The study is registered in Clinical Trial databases in China (ChiCTR2100048981, July 19, 2021) and the US (NCT04754139, February 11, 2021)
Monetary incentives and peer referral in promoting secondary distribution of HIV self-testing among men who have sex with men in China: A randomized controlled trial
Background Digital network–based methods may enhance peer distribution of HIV self-testing (HIVST) kits, but interventions that can optimize this approach are needed. We aimed to assess whether monetary incentives and peer referral could improve a secondary distribution program for HIVST among men who have sex with men (MSM) in China. Methods and findings Between October 21, 2019 and September 14, 2020, a 3-arm randomized controlled, single-blinded trial was conducted online among 309 individuals (defined as index participants) who were assigned male at birth, aged 18 years or older, ever had male-to-male sex, willing to order HIVST kits online, and consented to take surveys online. We randomly assigned index participants into one of the 3 arms: (1) standard secondary distribution (control) group (n = 102); (2) secondary distribution with monetary incentives (SD-M) group (n = 103); and (3) secondary distribution with monetary incentives plus peer referral (SD-M-PR) group (n = 104). Index participants in 3 groups were encouraged to order HIVST kits online and distribute to members within their social networks. Members who received kits directly from index participants or through peer referral links from index MSM were defined as alters. Index participants in the 2 intervention groups could receive a fixed incentive (15 USD) for ordering a kit. All index participants were assigned an online 3-month follow-up survey after ordering kits. The primary outcomes were the mean number of alters motivated by index participants in each arm and the mean number of newly tested alters motivated by index participants in each arm. These were assessed using zero-inflated negative binomial regression to determine the group differences in the mean number of alters and the mean number of newly tested alters motivated by index participants. Analyses were performed on an intention-to-treat basis. We also conducted an economic evaluation using microcosting from a health provider perspective with a 3-month time horizon. The mean number of unique tested alters motivated by index participants was 0.57 ± 0.96 (mean ± standard deviation [SD]) in the control group, compared with 0.98 ± 1.38 in the SD-M group (mean difference [MD] = 0.41),and 1.78 ± 2.05 in the SD-M-PR group (MD = 1.21). The mean number of newly tested alters motivated by index participants was 0.16 ± 0.39 (mean ± SD) in the control group, compared with 0.41 ± 0.73 in the SD-M group (MD = 0.25) and 0.57 ± 0.91 in the SD-M-PR group (MD = 0.41), respectively. Results indicated that index participants in intervention arms were more likely to motivate unique tested alters (control versus SD-M: incidence rate ratio [IRR = 2.98, 95% CI = 1.82 to 4.89, p-value < 0.001; control versus SD-M-PR: IRR = 3.26, 95% CI = 2.29 to 4.63, p-value < 0.001) and newly tested alters (control versus SD-M: IRR = 4.22, 95% CI = 1.93 to 9.23, p-value < 0.001; control versus SD-M-PR: IRR = 3.49, 95% CI = 1.92 to 6.37, p-value < 0.001) to conduct HIVST. The proportion of newly tested testers among alters was 28% in the control group, 42% in the SD-M group, and 32% in the SD-M-PR group. A total of 18 testers (3 index participants and 15 alters) tested as HIV positive, and the HIV reactive rates for alters were similar between the 3 groups. The total costs were 24.54, and the average cost per alter tester was 14.90 and 24.65 and $49.07 in the SD-M-PR group. No study-related adverse events were reported during the study. Limitations include the digital network approach might neglect individuals who lack internet access. Conclusions Monetary incentives alone and the combined intervention of monetary incentives and peer referral can promote the secondary distribution of HIVST among MSM. Monetary incentives can also expand HIV testing by encouraging first-time testing through secondary distribution by MSM. This social network–based digital approach can be expanded to other public health research, especially in the era of the Coronavirus Disease 2019 (COVID-19). Trial registration Chinese Clinical Trial Registry (ChiCTR) ChiCTR190002543
Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
The recently discovered neutron star transient Swift J0243.6+6124 has been
monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT).
Based on the obtained data, we investigate the broadband spectrum of the source
throughout the outburst. We estimate the broadband flux of the source and
search for possible cyclotron line in the broadband spectrum. No evidence of
line-like features is, however, found up to . In the absence of
any cyclotron line in its energy spectrum, we estimate the magnetic field of
the source based on the observed spin evolution of the neutron star by applying
two accretion torque models. In both cases, we get consistent results with
, and peak luminosity of which makes the source the first Galactic ultraluminous
X-ray source hosting a neutron star.Comment: publishe
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