A game-theoretic approach for federated learning:A trade-off among privacy,accuracy and energy

Benefiting from the development of Federated Learning(FL)and distributed communication systems,large-scale intelligent applications become possible.Distributed devices not only provide adequate training data,but also cause privacy leakage and energy consumption.How to optimize the energy consumption in distributed communication systems,while ensuring the privacy of users and model accuracy,has become an urgent challenge.In this paper,we define the FL as a 3-layer architecture including users,agents and server.In order to find a balance among model training accuracy,privacy-preserving effect,and energy consumption,we design the training process of FL as game models.We use an extensive game tree to analyze the key elements that influence the players’decisions in the single game,and then find the incentive mechanism that meet the social norms through the repeated game.The experimental results show that the Nash equilibrium we obtained satisfies the laws of reality,and the proposed incentive mechanism can also promote users to submit high-quality data in FL.Following the multiple rounds of play,the incentive mechanism can help all players find the optimal strategies for energy,privacy,and accuracy of FL in distributed communication systems.

Development of a DFN-based probabilistic block theory approach for bench face angle design in open pit mining

In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.

Effects of adjuvant Chinese patent medicine therapy on major adverse cardiovascular events in patients with coronary heart disease angina pectoris:a population-based retrospective cohort study

Objective: This study aimed to explore the effects of Chinese patent medicine(CPM) in reducing the incidence of major adverse cardiovascular events(MACE) in patients with coronary heart disease(CHD) angina pectoris and improving clinical effectiveness and provide evidence for its use as clinical adjuvant therapy.Methods: Twenty-eight thousand five hundred and seventeen patients hospitalized with CHD angina pectoris from 6 hospitals were divided into CPM group(n = 11,374) and non-CPM group(n = 17,143) to evaluate the incidence of MACE, including myocardial infarction, percutaneous coronary intervention, and coronary artery bypass grafting.Results: The incidence of MACE in the CPM group was lower than that in the non-CPM group. CPM therapy was an independent protective factor that reduced the overall risk of MACE [adjusted hazard ratio = 0.40, 95% confidence interval(0.33;0.49)]. Patients in the CPM group who received one, two, or three types of CPM could benefit from adjuvant treatment with CPM, and taking more types of CPM was associated with a lower risk of MACE. In addition, the male population was better than the female population at taking CPM, and middle-aged people aged 55 to 64 were more suited to take CPM based on Western medicine.Conclusions: The use of CPM as adjuvant therapy can decrease the occurrence of MACE in patients with CHD angina pectoris,especially in men and middle-aged people, and the drug treatment plan should be optimized accordingly. However, this conclusion needs further verification by prospective cohort studies in the future.

Sensitivity of two drug-resistant bacteria to low-temperature air plasma in catheterassociated urinary tract infections under different environments

The high incidence of catheter-associated urinary tract infections,which are dominated by drugresistant bacteria,has attracted an increasing number of researchers interested in solving this public health problem.The purpose of this study was to explore the killing effect of lowtemperature air plasma(LTAP)on extended-spectrum beta-lactamase-producing Escherichia coli and high level gentamycin resistance enterococci under two simulated environments in vitro.The results showed that the survival rate of these two kinds of bacteria decreased to less than20%after being treated by LTAP in different environments for 5 min.A comparison of the LTAP treatments showed that the killing efficacy of the two kinds of bacteria in the early stage(0-1 min)was up to 50%.Moreover,the results of transmission electron microscopy,reactive nitrogen species measurement,and a temperature test indicated that the bactericidal effect of the LTAP treatment on the two kinds of bacteria worked through the destruction of the ribosome and other organelles inside the bacteria,rather than the thermal effect,to achieve sterilization.

聚二甲基硅氧烷-水性聚氨酯的合成与性能

为了提高水性聚氨酯的耐水性和耐候性,文中以羟烷基聚二甲基硅氧烷(PDMS)和聚己二酸丁二醇酯二醇(PBA)为混合软段,间苯二亚甲基二异氰酸酯(XDI)和1,4-丁二醇(BDO)、二羟甲基丙酸(DMPA)为硬段,采用二步本体法合成一系列的聚二甲基硅氧烷-水性聚氨酯(Si-XWPUs),研究了PDMS在软段中的含量对水性聚氨酯的表面性能、力学性能和耐水性的影响。研究发现,随着PDMS在软段中的含量从0%到20%逐渐增加,Si-XWPUs的微相分离程度略有提高,拉伸强度均达到10 MPa以上,作为涂层材料均具有较好的力学性能。同时,随PDMS在软段中比例的升高,Si-XWPUs薄膜表面Si元素的百分比呈增加趋势,并且表面的Si/C含量远远高于本体中理论Si/C含量,最高的迁移率达24倍,表现出良好的疏水性,同时吸水率降低。

Being Chinese in Lived Intercultural Experiences:A Discourse Analysis of Chinese Undergraduates’Perceptions of Chinese Culture

The current study investigates a group of Chinese undergraduates’perceptions of Chinese culture.It examines the discourses that the students drew on to assign meaning to Chinese culture and how the students used these discourses in constructing their Chinese cultural identity.A qualitative study was conducted collecting written self-reflective reports on critical intercultural incidents from 39 Chinese undergraduates at a university in Beijing.Questions designed to evoke reports from the students had them describe incidents in their past intercultural experiences that made them acutely aware of themselves“being Chinese”and specify aspects of Chinese culture that they felt such awareness could be attributed to.A discourse analysis reveals the multiplicity and contextuality of the students’notions of Chinese culture.The findings raise important considerations for contemporary Chinese undergraduates’cultural identity and their much debated“identity crisis.”

Combination of photodynamic therapy and stimulator of interferon genes(STING)agonist inhibits colorectal tumor growth and recurrence

Dear Editor,Great progress has been made in the clinical use of photodynamic therapy(PDT)for the treatment of patients with superficial tumors[1].However,cancer recurrence and metastasis have limited the application of PDT in the treatment of solid tumors and advanced cancers.In this context,combining PDT with other complementary immunotherapy regimens may overcome these limitations of PDT[2].

Petrologic and geochemical characteristics of high-quality saline lacustrine source rocks in western Qaidam Basin

The main oil source in western Qaidam Basin is the Paleogene saline lacustrine source rocks.Traditionally,it was considered that these source rocks were characterized by low abundance and poor type of organic matter as well as limited oil generation potential,but this poor source rock condition was very inconsistent with good hydrocarbon exploration results.A previous study has just confirmed that this area develops high-quality source rocks,which is of great significance for recognizing potential of hydrocarbon resource and consolidating confidence to search large and medium-sized oil and gas fields in western Qaidam Basin.Based on fine geochemical analysis of source rocks,petrology,element geochemistry and organic geochemistry are applied to discuss development conditions of high-quality source rocks in this area.The results showed that the saline lacustrine sediments in western Qaidam Basin were deposited in relatively shallow and quiet water with relatively high salinity and low nutrient content;influenced by the drought and cold climate,the terrigenous supply of fresh water was limited,and few aquatic organisms were developed.Good preservation condition is favorable for rapid preservation of oil generating biomass(such as aquatic organisms),to form source rocks rich in hydrogen element with high soluble organic matter content;but relatively lower paleo-productivity makes organic matter abundance lower than that in the eastern saline lacustrine basins.The semi-deep lake,with relatively low salinity and abundant nutrients,is the most favorable are for development of high-quality source rocks;the source rocks have large thickness in the sedimentary depression areas,but due to high water salinity and far away from the provenance area,the water stratification was obvious,so it have moderate to high organic matter abundance.

Aerodynamic analysis of insect-like flapping wings in fan-sweep and parallel motions with the slit effect

In this study,the aerodynamic performance of flapping wings using a parallel motion was investigated and compared with the insect-like‘‘fan-sweep’’motion,and the effect of adding a slit to the wings was analyzed.First,numerical simulations were performed to analyze the wing aerodynamics of two flapping motions with equivalent stroke amplitudes over a range of pitching angles based on computational fluid dynamics(CFD).The simulation results indicated that flapping wings with a rapid and short parallel motion achieved better lift and efficiency than those of the fan-sweep motion while maintaining the same aerodynamic characteristics regarding stall delay and leading-edge vortices.For a parallel motion with a pitching angle of 25◦and 100 mm stroke amplitude,the wings generated an average lift of 8.4 gf with a lift-to-drag ratio of 1.06,respectively,which were 1.8%and 26%greater than those of the fan-sweep motion with a corresponding 96◦stroke amplitude.This situation was reversed when the pitching angle and stroke amplitude were increased to 45◦and 144◦for the fan-sweep motion,which was equivalent to the parallel motion with a 150 mm stroke amplitude.The slit effect in the parallel motion was also evaluated,and the CFD results indicated that a slit width of 1 mm(1/50 wing chord)increased the lift of the wing by approximately 27%in the case of the 150 mm stroke amplitude.Further,the slit width slightly influenced the lift and aerodynamic efficiency.

Working principle and application of photocatalytic optical fibers for the degradation and conversion of gaseous pollutants

Photocatalytic optical fibers are promising for the degradation of gaseous and volatile pollutants in air due to their high specific surface area,high light utilization efficiency,easy regeneration,and sustainability.In particular,photocatalytic optical fibers have proven highly useful for the removal and conversion of different kinds of air pollutants in air.However,these fibers suffer from low photocatalytic degradation efficiencies.In this review,we have focused on introducing photocatalytic quartz optical fibers and photocatalytic plastic optical fibers for the degradation and transformation of gas-phase air pollutants.The principle of photocatalytic optical fibers and main methods for improving their photocatalytic and light utilization efficiencies based on semiconductor photocatalytic coatings are summarized.Moreover,the Langmuir-Hinshelwood kinetic rate equation was summarized to analyze the photocatalytic reduction of gaseous pollutants.Finally,an outlook on the future of photocatalytic optical fibers toward the removal and conversion of gaseous air pollutants is discussed.

Lightnin内插件强化混合器内湍流混合及反应特性

采用计算流体力学组分输运模型和SST k-ω湍流模型,在Re=3000~9000范围内研究Lightnin静态混合器内萘酚(组分A)与对氨基苯磺酸(组分B)偶合氮化串联竞争反应,分析化学反应场中各组分浓度分布规律、湍流流动及微观混合特性。Lightnin内插件能够推进管内主反应的高效进行,副产物S较少且其浓度在0.0004~0.03 mol/L,而主产物R的浓度较副产物S高两个数量级。湍流强度随着雷诺数的增大呈现明显上升趋势,Re=3000时z/l=2处的湍流强度峰值(达到2.95)是出口处的2.02倍。湍流耗散率ε随径向位置的增加而减小,w_(A)=0.5~0.6时浓度对ε的影响微弱,而w_(A)=0.7~0.9时ε的轴向和径向分布随着浓度的增大逐渐减小,w_(A)=0.6~0.9时z/l=10处的ε相比于w_(A)=0.5时依次减小2.43%,8.86%,19.80%,42.25%。Re=6000~9000时径流数呈周期规律分布,偶数旋流元件内形成小峰值,奇数元件内则内凹。组分A与组分B在摩尔比一定的条件下,Re=4000~9000出口位置处的微观混合特性相比于Re=3000时分别增强18.22%~55.34%。

Depression and stress levels increase risk of liver cancer through epigenetic downregulation of hypocretin

Recent studies suggest that Hypocretin (HCRT, Orexin) are involved in stress regulation of depression through the hypothalamic-pituitary-adrenal (HPA) axis. However, the molecular mechanism by which Hypocretin regulate neurobiological responses is unknown. Herein, the effects of chronic stress on the epigenetic modification of HCRT and its association with depression were explored with regard to a potential role in cancer progression. In the study, Sprague Dawley (SD) rats were used to establish an animal model of cancer with depression by administrating n-nitrosodiethylamine (DEN) and chronic unpredictable mild stress (CUMS). RNA-sequencing was used to detect differentially expressed genes in the hippocampus of rats and quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the results of RNA-sequencing. The status of HCRT promoter methylation was assessed by methylation specific polymerase chain reaction. Behavioral tests showed that rats exposed to CUMS had significant depressive-like behaviors. The number of liver tumors and tumor load in depressed rats exposed to CUMS was higher than in SD rats without CUMS. RNA-sequencing revealed that HCRT was one of the most siginificantly downregulated gene in the hippocampus of SD rats with CUMS compared to non-stressed group, which was validated by qRT-PCR. HCRT mRNA expression was downregulated and the promoter for HCRT was hyper-methylated in those with depression. These results identified a critical role for chronic psychological stressors in tumorigenesis and cancer progression, via epigenetic HCRT downregulation. Such epigenetic downregulation may be the molecular basis for the association of cancer with depression.