Context-aware Sequential Recommendation

Since sequential information plays an important role in modeling user behaviors, various sequential recommendation methods have been proposed. Methods based on Markov assumption are widely-used, but independently combine several most recent components. Recently, Recurrent Neural Networks (RNN) based methods have been successfully applied in several sequential modeling tasks. However, for real-world applications, these methods have difficulty in modeling the contextual information, which has been proved to be very important for behavior modeling. In this paper, we propose a novel model, named Context-Aware Recurrent Neural Networks (CA-RNN). Instead of using the constant input matrix and transition matrix in conventional RNN models, CA-RNN employs adaptive context-specific input matrices and adaptive context-specific transition matrices. The adaptive context-specific input matrices capture external situations where user behaviors happen, such as time, location, weather and so on. And the adaptive context-specific transition matrices capture how lengths of time intervals between adjacent behaviors in historical sequences affect the transition of global sequential features. Experimental results show that the proposed CA-RNN model yields significant improvements over state-of-the-art sequential recommendation methods and context-aware recommendation methods on two public datasets, i.e., the Taobao dataset and the Movielens-1M dataset.Comment: IEEE International Conference on Data Mining (ICDM) 2016, to apea

BlockEmulator: An Emulator Enabling to Test Blockchain Sharding Protocols

Numerous blockchain simulators have been proposed to allow researchers to simulate mainstream blockchains. However, we have not yet found a testbed that enables researchers to develop and evaluate their new consensus algorithms or new protocols for blockchain sharding systems. To fill this gap, we develop BlockEmulator, which is designed as an experimental platform, particularly for emulating blockchain sharding mechanisms. BlockEmulator adopts a lightweight blockchain architecture such that developers can only focus on implementing their new protocols or mechanisms. Using layered modules and useful programming interfaces offered by BlockEmulator, researchers can implement a new protocol with minimum effort. Through experiments, we test various functionalities of BlockEmulator in two steps. Firstly, we prove the correctness of the emulation results yielded by BlockEmulator by comparing the theoretical analysis with the observed experiment results. Secondly, other experimental results demonstrate that BlockEmulator can facilitate the measurement of a series of metrics, including throughput, transaction confirmation latency, cross-shard transaction ratio, the queuing size of transaction pools, workload distribution across blockchain shards, etc. We have made BlockEmulator open-source in Github

Mobilization of Mesenchymal Stem Cells by Granulocyte Colony-stimulating Factor in Rats with Acute Myocardial Infarction

Abstract Purpose Intravenous delivery of mesenchymal stem cells (MSCs), a noninvasive strategy for myocardial repair after acute myocardial infarction (MI), is limited by the low percentage of MSCs migration to the heart. The purpose of this study was to test whether granulocyte colony-stimulating factor (G-CSF) would enhance the colonization of intravenously infused MSCs in damaged heart in a rat model of acute MI. Methods After induction of anterior MI, Sprague-Dawley rats were randomized to receive: (1) saline (n=9); (2) MSCs (n=15); and (3) MSCs plus G-CSF (50 μg/kg/day for 5 consecutive days, n=13). Results Flow cytometry revealed that G-CSF slightly increased surface CXCR4 expression on MSCs in vitro. After completion of G-CSF administration, MSCs showed a significantly lower colonization in bone marrow and a trend toward higher localization in the infarcted myocardium. At 3 months, vessel density in the infarct region of heart was significantly increased in MSCs group and trended to increase in MSCs+G-CSF group. However, echocardiographic and hemodynamic parameters, including left ventricular (LV) end-diastolic diameters, ejection fraction, and ±dP/dt max , were not statistically different. Morphological analysis showed that infarct size and collagen content were similar in the three groups. Immunohistochemistry revealed that the combined therapy accelerated endothelial recovery of the blood vessels in the ischemic myocardium. However, myocardial regeneration resulting from MSCs differentiation was not observed. Conclusions G-CSF enhanced the migration of systemically delivered MSCs from bone marrow to infarcted heart. However, the beneficial effect of this kind of migration is limited, as cardiac function did not improve

Spatio-temporal variations of the major meteorological disasters and its response to climate change in Henan Province during the past two millennia

In China, historical documents have recorded large quantities of information related to natural disasters, and these disasters have had long-lasting effects on economic and social activities. Understanding the occurrence of the natural disasters and their spatio-temporal variation characters is crucial for sustainable of our society. Therefore, based on the collection and collation of historical documents, and adopting mathematical statistics, Kriging interpolation, correlation analysis and other methods, we systematically explored the meteorological disasters in Henan Province during the past two millennia in analyzing their spatio-temporal distribution characters and driving forces. The results demonstrate that there were five major types of meteorological disasters in Henan Province, including drought, flood, hails, low temperature and frost and insect pests, which presented obvious spatio-temporal variations and have occurred frequently during the past two millennia. According to the historical documents, the major meteorological disasters occurred 1,929 times in Henan from 221 BCE to 2000 CE. On the whole, the disaster frequency show that the occurrence cycle of the meteorological disasters has obvious changes, which mainly occurred in the middle and late stages during the past two millennia, especially after 1300 CE. Furthermore, we also find that the variation of meteorological disaster events is consistent with the variation of temperature in eastern China and the frequency of meteorological disaster increases in the cold period, but decreases in the warm period. In addition, there are obvious differences in the spatial distribution of the major meteorological disaster, which were mainly distributed in the northwest and southern part region of the Henan Province before 1911 CE. While after 1911 CE, the northern and southeastern parts were the meteorological disaster-prone areas in this region during this period. Spatial correlation analysis of each meteorological disaster before and after 1911 CE points out the droughts disaster frequency-occurring district has transferred in different periods, while the hail and low temperature and frost disasters just have a smaller transferred during these two periods. Conversely, the frequency-occurring districts of floods and insect pest disasters have no obviously transferred in different periods. These results can provide an important scientific basis for governmental decision makers and local people to prevent and mitigate meteorological disaster in the future

Low carbon optimal operation of integrated energy systems considering air pollution emissions

To reduce carbon, sulfur dioxide (SO2) and nitrogen oxide (NOX) emissions from the integrated energy system (IES), a low carbon optimization strategy for the IES is proposed, taking into account carbon, SO2 and NOXemissions. Firstly, hydrogen production, storage and use equipment such as methane reactor, electrolysis tank, hydrogen fuel cell and hydrogen energy storage are added to the traditional IES to build a multi-energy complementary system of electricity, gas, cooling, thermal and hydrogen. Then this paper introduces a stepped carbon trading mechanism and the model of the emissions of SO2 and NOX. Finally, to further reduce its pollutant emissions, the model of combined heat and power units and hydrogen fuel cells with adjustable thermoelectric ratio is built. To compare and account for the impact of air pollutant emissions on the optimal low-carbon operation of IES, this paper construsted three scenarios, with the lowest cost of carbon trading, the lowest penalty cost for SO2 and NOXemissions and total operation cost as objective functions respectively The results show that the strategy is effective in reducing air pollutant emissions from integrated energy systems and the outputs of CHP and HFC with adjustable thermoelectric ratios are more flexible and can effectively achieve carbon reduction and pollutant emission reduction

An evaluation of a tailored intervention on village doctors use of electronic health records

BACKGROUND: To describe and evaluate the effectiveness of tailored intervention on village doctor’s use of electronic health records (EHR) in rural community health services in less developed areas. METHODS: Ten townships were selected. In each township, two similar health service station (CHSS) were chosen. One was randomly as allocated to the intervention group, the other to the control group. Over six monthly visits, a structured on-site intervention including education, supervision and technical support was provided to village doctors in the intervention group tailored to their needs. The Control group received no visits. A sample of 20 families from each CHSS was randomly chosen. An online evaluation of each family’s EHR was conducted by the investigators at baseline and at the end of the 6 month intervention. RESULTS: In the intervention group, the proportion of households with complete records increased: basic personal information from 2.6% to 32.5%, (Z = -15.099, P = 0.000) and health education records from 0.3% to 1.6% (Z = -4.459, P = 0.000). Similarly at baseline none of the 80 elders had her records. This increased in the intervention group to 16.4% recorded in part and 37.0% in full (Z = -7.480, P = 0.000). The proportion of complete health management records for children aged 1 to 2 years and 3 to 6 years increased from 28.6% and 33.3% to 66.7% and 74.2% respectively (the difference of children group 3 to 6 years of age was statistically significant, Z = -3.860, p = 0.000). The proportion of complete basic clinic records in the intervention group increased from 7.6% to 13.9% (Z = -3.252, P = 0.001). There were no significant differences in the control group. CONCLUSIONS: The pilot study showed that a on-site education, supervision and technical support tailored to their needs was associated with improvements in village doctors use of EHR. This model is worthy of implementation in other rural areas

Survey Analysis of Occupational Impact on Perception of Air Pollution and Its Health Effect

Abstract Rapid economic development has brought many pollution problems such as air pollution in China, which also obstructed economic and social development. A cross-sectional survey was conducted among residents with different occupations in Nanchang and Wuyuan, China, from July to August 2015. Anonymous questionnaires were used to understand participant's perception on current air pollution. Descriptive analysis was performed for the general demographic information of the participants and a chi-squared test was conducted to estimate the perception of participants towards air pollution. Binary logistic regression analysis was conducted for the association between socio-demographic and willingness to pay for the air pollution. The result of the chi-squared tests showed that the perception of different occupation groups toward local air quality was statically significantly different (χ2=731.166, p<0.05). This surveyed showed that over 90% of the participants from all the occupational groups considered improving air quality is essentially important and should be the responsibility of both the government and individual citizen. All the participants support the local government to place more funding on air quality improvement, but more than 50% of respondents are not willing to pay additional money for air pollution control (OR=11.025). This information will be useful to the local government in its process of funding preparation and the development of more effective and practical regulation to control air pollution in future

Research on the Relationships between Psychological Problems and School Bullying and Non-Suicidal Self-Injury among Rural Primary and Middle School Students in Developing Areas of China

(1) Purpose: To analyze the role of psychological problems in connection with school bullying and non-suicidal self-injury (NSSI) among rural primary and middle school students in developing areas of China. (2) Methods: A multi-stage, stratified, cluster random sampling method was used to select 2284 rural primary and middle school students in Jiangxi Province for study. Questionnaires regarding the health risk behaviors of children in developing areas were left behind at primary and middle schools, and they were later collected and analyzed by using the mental health diagnostic monitoring scale for Chinese primary and middle school students. Pearson correlation, logistic regression, and bootstrap tests were conducted to analyze the association between psychological problems, school bullying, and NSSI. (3) Results: The incidence of NSSI in rural primary and middle school students in Jiangxi Province was 14.84%. Compared with other children with behavioral problems, those who had experienced school bullying and had mild/severe psychological problems were more likely to have engaged in NSSI behaviors (p < 0.001). Psychological problems have a mediating effect between school bullying and NSSI, which accounted for 12.96% of the total effect. (4) Conclusion: Psychological problems are likely an effect modifier in the connection between school bullying and NSSI behaviors. Therefore, effectively targeting psychological problems in rural primary and middle school students in Jiangxi Province may help prevent and control NSSI behaviors in students who have experienced school bullying

Research on Relationships between Sexual Identity, Adverse Childhood Experiences and Non-Suicidal Self-Injury among Rural High School Students in Less Developed Areas of China

Purpose: The objective of this study was to examine the influence of sexual identity and adverse childhood experiences (ACEs) on non-suicidal self-injury (NSSI) among rural high school students in less developed areas of China. Methods: Behavior risk factors data collected from 1810 students from a high school in Jiangxi province, China. Five measures of childhood abuse and household dysfunction were summarized, and ACE was divided into 0, 1, 2, 3–5 ACEs. Logistic regression analysis was used to explore the influence of sexual identity, adverse childhood experiences, and their interaction with non-suicidal self-injury. Results: Compared with heterosexual students, high school students who identify as lesbian, gay, or bisexual (LGB) have a higher tendency of non-suicidal self-injury (AOR = 3.250, 95% CI = 1.69–6.28, p < 0.01). There was also a graded relationship between cumulative ACEs exposure and non-suicidal self-injury behaviors (AOR = 1.627, 95% CI = 1.02–2.60, p < 0.05). Odds for NSSI are higher among students with both experienced ACEs and identified as LGB (AOR = 2.821, 95% CI = 1.51–5.29, p < 0.05). Conclusions: Non-suicidal self-injury is associated with ACEs exposure and with those who identify as LGB, and the NSSI odds are greater when students identify as LGB and have experienced ACEs. More interventions to reduce non-suicidal self-injury should focus on LGB and ACEs and more attention needs to be paid to those who identify as LGB and have been exposed to ACEs