Approximating Nash equilibrium for anti-UAV jamming Markov game using a novel event-triggered multi-agent reinforcement learning.

In the downlink communication, it is currently challenging for ground users to cope with the uncertain interference from aerial intelligent jammers. The cooperation and competition between ground users and unmanned aerial vehicle (UAV) jammers leads to a Markov game problem of anti-UAV jamming. Therefore, a model-free method is adopted based on multi-agent reinforcement learning (MARL) to handle the Markov game. However, the benchmark MARL strategies suffer from dimension explosion and local optimal convergence. To solve these issues, a novel event-triggered multi-agent proximal policy optimization algorithm with Beta strategy (ETMAPPO) is proposed in this paper, which aims to reduce the dimension of information transmission and improve the efficiency of policy convergence. In this event-triggering mechanism, agents can learn to obtain appropriate observation in different moment, thereby reducing the transmission of valueless information. Beta operator is used to optimize the action search. It expands the search scope of policy space. Ablation simulations show that the proposed strategy achieves better global benefits with fewer dimension of information than benchmark algorithms. In addition, the convergence performance verifies that the well-trained ETMAPPO has the capability to achieve stable jamming strategies and stable anti-jamming strategies. This approximately constitutes the Nash equilibrium of the anti-jamming Markov game.

Tourism and Green Development: Analysis of Linear and Non-Linear Effects.

Clarifying the relationship between tourism and green development is conducive to promoting the harmonious coexistence of tourism industry benefits and economic and environmental systems. The externalities of tourism on economies and the environment have sparked numerous fascinating academic research debates; however, few studies have considered the impact of tourism on green development that balances economic growth and environmental protection. This study selects the green development efficiency measured by the super-efficient SBM model with undesired output as a proxy indicator of green development and adopts the panel data regression model and dynamic panel threshold regression model to investigate the linear impact and non-linear characteristics of tourism on the green development efficiency for 284 cities in mainland China at the prefecture level and above. The main findings are as follows: (1) Although China's green development efficiency showed an upward trend during the study period, the overall level was not high. (2) Tourism has significantly promoted the improvement of China's green development efficiency, indicating that tourism has become an effective driver of China's economic green transformation. (3) This type of positive promotion of green development by tourism has a non-linear threshold characteristic, which means that, with the continuous improvement of the development level of the tourism industry, after crossing a specific threshold value and entering a higher level of development, the tourism industry will have an increasing marginal impact on the green development efficiency.

Household air pollution and childhood stunting in China: A prospective cohort study.

Background: Exposure to air pollution, especially indoor air pollution, was associated with an increased risk of childhood stunting. However, few longitudinal studies have explored the long-term impacts of indoor air pollution from household solid fuel use on child growth. We aimed to investigate the association between household air pollution (HAP) from solid fuel use and childhood stunting in Chinese children. Method: The longitudinal data from the Chinese Family Panel Study over 2010-2018 were included in this study with a total of 6,013 children aged 0-15 years enrolled at baseline. Exposure to HAP was measured as solid fuel use for cooking, while solid fuel was defined as coal and firewood/straw according to the questionnaire survey. Stunting was defined as-2SD below the height-for-age z-score (HAZ) of the reference children. Logistic regression and Cox proportional hazards models with time-varying exposures were employed to estimate the association between childhood stunting and HAP exposure. Results: At baseline, children with exposure to HAP from combusting solid fuels had a relatively higher risk of stunting [OR (95%CI): 1.42 (1.24-1.63)]. Among children without stunning at baseline, those living in households with solid fuel use had a higher stunting risk over an 8-year follow-up [HR (95%CI): 2.05 (1.64-2.57)]. The risk of childhood stunting was increased for those with HAP exposure from firewood/straw combustion or with longer exposure duration [HR (95%CI): 2.21 (1.74-2.79) and 3.01 (2.23-4.08), respectively]. Meanwhile, this risk was significantly decreased among children from households switching from solid fuels to clean fuels [HR (95%CI): 0.53 (0.39-0.70)]. Solid fuel use was suggested to be a mediator of the relationship between poor socioeconomic factors (i.e., household income and parental education level) and childhood stunning, with a mediation effect ranging from 11.25 to 14.26%. Conclusions: HAP exposure from solid fuel use was associated with childhood stunting. Poor parental education and low household income might be socioeconomic factors contributing to solid fuel use. Therefore, household energy policies to facilitate access to clean fuels are urgently needed, especially for low-income and low-educated households.

Loss of Selenov predisposes mice to extra fat accumulation and attenuated energy expenditure.

Selenoprotein V (SELENOV) is a new and the least conserved member of the selenoprotein family. Herein we generated Selenov knockout (KO) mice to determine its in vivo function. The KO led to 16-19% increases (P < 0.05) in body weight that were largely due to 54% higher (P < 0.05) fat mass accumulation, compared with the wild-type (WT) controls. The extra fat accumulation in the KO mice was mediated by up-regulations of genes and proteins involved in lipogenesis (Acc, Fas, Dgat, and Lpl; up by 40%-1.1-fold) and down-regulations of lipolysis (Atgl, Hsl, Ces1d, and Cpt1a; down by 36-89%) in the adipose tissues. The KO also decreased (P < 0.05) VO2 consumption (14-21%), VCO2 production (14-16%), and energy expenditure (14-23%), compared with the WT controls. SELENOV and O-GlcNAc transferase (OGT) exhibited a novel protein-protein interaction that explained the KO-induced decreases (P < 0.05) of OGT protein (15-29%), activity (33%), and function (O-GlcNAcylation, 10-21%) in the adipose tissues. A potential cascade of SELENOV-OGT-AMP-activated protein kinase might serve as a central mechanism to link the biochemical and molecular responses to the KO. Overall, our data revealed a novel in vivo function and mechanism of SELENOV as a new inhibitor of body fat accumulation, activator of energy expenditure, regulator of O-GlcNAcylation, and therapeutic target of such related disorders.

A survey of postpartum depression and health care needs among Chinese postpartum women during the pandemic of COVID-19.

BACKGROUND: The COVID-19 pandemic seriously endangers the public's mental health, especially to pregnant and postpartum women. But little is known about postpartum depression and health care needs among Chinese postpartum women. AIM: To investigate the status and risk factors of postpartum depression and health care needs among Chinese postpartum women during the COVID-19 pandemic. METHODS: In this cross-sectional study, 209 Chinese postpartum women were recruited from May to July 2020 by convenience sampling and assessed online with self-designed Maternal General Information Questionnaire, Edinburgh Postpartum Depression Scale (EPDS) and Chinese Version of the Perceived Stress Scale (CPSS). Descriptive statistics, chi-square test, independent samples t-test, one-way ANOVA, Pearson correlation and multiple linear regression were used for data analysis. RESULTS: With the EPDS cut-off value of 10, the incidence of postpartum depressive symptoms was 56.9%. Age, history of abortion and perceived stress were the influencing factors of postpartum depression (adjusted R2 = 0.432, F = 23.611, p < .001). The top three health care needs were infant rearing guidance (78.0%), maternal and infant protection guidance (60.3%) and dietary guidance (45.0%). The proportion of psychological rehabilitation guidance needs in the depressed group was significantly higher than that in the non-depressed group (34.5% vs. 20.0%, p < .05). CONCLUSIONS: Maternal postpartum depression in China was at a high level during the COVID-19 pandemic. Women aged 25-34, with a history of abortion and high stress levels were at higher risk for postpartum depression. Timely psychological counselling, intervention and COVID-19-related health education are in great need for postpartum women.

Structural analysis and allergenicity assessment of an enzymatically cross-linked bovine α-lactalbumin polymer.

Enzymatic cross-linking is frequently used in bio-processing of dairy products since it could change the physiochemical and functional characterization. In our study, bovine α-lactalbumin was cross-linked by polyphenol oxidase from Agaricus bisporus and the changes in the structure, digestibility and allergenicity of α-lactalbumin were explored after cross-linking, and the structural alterations of the polymers were analyzed by circular dichroism spectroscopy, ultraviolet absorption spectroscopy and fluorescence spectroscopy. The digestibility of cross-linked α-lactalbumin was evaluated by simulated digestion in vitro. After that, the allergenicity of α-lactalbumin polymers was evaluated by detection of the specific IgE binding ability using an animal model. The results showed that the secondary and tertiary structures of various α-lactalbumin polymers exhibited a significant variation compared with those of untreated α-lactalbumin, and the cross-linked α-lactalbumin was relatively less susceptible to digestion. Moreover, the allergenicity of cross-linked polymers decreased significantly. These results suggested that there was a direct correlation between a loss of an α-helix and IgE binding to α-lactalbumin, which indicated that enzymatic cross-linking might be an efficient approach to reduce the allergenicity of bovine α-lactalbumin.

A Comparative Study of the Role of Australia and New Zealand in Sustainable Dairy Competition in the Chinese Market after the Dairy Safety Scandals.

After the melamine milk scandal in 2008, China's global imports of dairy products soared, especially after FTAs had been established with Australia and New Zealand. The dairy products of the two countries have a unique competitive trading advantage in the Chinese market. However, at a time when Chinese consumers are increasingly dependent on imported dairy products, a succession of whey protein scandals affecting New Zealand's dairy products in 2013 had a negative psychological impact on Chinese importers and consumers, and this even affected the import status of New Zealand dairy imports to the Chinese market. The present paper, based on the United Nations Comtrade Harmonized System, studies the role of Australia and New Zealand in China's dairy market. It calculates the trade competitiveness index, revealing the relative competitive advantages of Australia and New Zealand, and investigates the impact of the dairy products from these countries on China's imports from the rest of the world across six dairy sectors in the period 1992⁻2017. We find that, under the food safety laws, the relative dairy import prices, milk scandals, and Free Trade Agreements, together with the competitive advantages of Australia and New Zealand, had a varied impact on the corresponding Chinese dairy imports across the relevant sectors in the context of China food safety laws after the melamine milk scandal. These findings acknowledge Australia and New Zealand's competitiveness in the international dairy trade, and also lead to suggestions regarding their competitiveness and sustainable development in the Chinese market.

Field investigations of dissipations and residues of cyazofamid in soil and tomato: risk assessment of human exposure to cyazofamid via tomato intake.

Cyazofamid, as a fungicide of the novel cyanoimidazole chemical class, has been widely used to control tomato late blight. Understanding of cyazofamid residues in environment and crops is an essential prerequisite for its risk assessment. In this study, field investigations in four typical tomato-producing areas were conducted to explore the dissipation kinetics and residues of cyazofamid and its primary metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) in soil and tomato. A robust method using QuEChERS coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for simultaneous analysis of cyazofamid and CCIM, with limits of quantification of 0.33 and 3.8 µg/kg, respectively. Field trials showed that the half-lives of cyazofamid were 3.6-6.9 days in soil and 12.2-18.3 days in tomato. The total residues of cyazofamid and CCIM in tomato collected at three time intervals were all below 0.5 mg/kg. Moreover, the potential risks of total residues via tomato intake to ten population subgroups were evaluated. We found that the risk quotient values were all generally low (0.13-1.3%), indicating that the recommended dose of cyazofamid on tomato will not result in a consumer exposure exceeding the toxicological reference value. Here, the results of field investigation provided important information for further understanding the behavior and risk of cyazofamid in the natural environment.

Gender differences in cerebral regional homogeneity of adult healthy volunteers: a resting-state FMRI study.

OBJECTIVE: We sought to use the regional homogeneity (ReHo) approach as an index in the resting-state functional MRI to investigate the gender differences of spontaneous brain activity within cerebral cortex and resting-state networks (RSNs) in young adult healthy volunteers. METHODS: One hundred and twelve healthy volunteers (56 males, 56 females) participated in the resting-state fMRI scan. The ReHo mappings in the cerebral cortex and twelve RSNs of the male and female groups were compared. RESULTS: We found statistically significant gender differences in the primary visual network (PVN) (P < 0.004, with Bonferroni correction) and left attention network (LAtN), default mode network (DMN), sensorimotor network (SMN), executive network (EN), and dorsal medial prefrontal network (DMPFC) as well (P < 0.05, uncorrected). The male group showed higher ReHo in the left precuneus, while the female group showed higher ReHo in the right middle cingulate gyrus, fusiform gyrus, left inferior parietal lobule, precentral gyrus, supramarginal gyrus, and postcentral gyrus. CONCLUSIONS: Our results suggested that men and women had regional specific differences during the resting-state. The findings may improve our understanding of the gender differences in behavior and cognition from the perspective of resting-state brain function.

Low-cost, high-speed identification of counterfeit antimalarial drugs on paper.

With the emergence of artesunate antimalarial counterfeiting in Southeast Asia and sub-Saharan Africa, we present the production of a rapid, inexpensive and simple colorimetric-based testing kit for the detection of counterfeit artesunate in order to preserve life and prevent the development of multi-drug resistant malaria. The kit works based on paper microfluidics which offer several advantages over conventional microfluidics, and has great potential to generate inexpensive, easy-to-use, rapid and disposable diagnostic devices. Here, we have developed a colorimetric assay that is specific to artesunate and turns yellow upon addition of the sample. The test can be done within minutes, and allows for a semi-quantitative analysis of the artesunate tablets by comparing the developed yellow color on the paper test to a color-coded key chart that comes with the kit. A more accurate and precise analysis is done by utilizing a color analyzer on an iPhone camera that measures the color intensity of the developed color on the paper chip. A digital image of the chip was taken and analyzed by measuring the average gray intensity of the color developed on the paper circle. A plot of the artesunate concentration versus the average gray scale intensity was generated. Results show that the intensity of the yellow color developed on the paper test was consistent and proportional to the amount of artesunate present in the sample. With artesunate concentrations ranging from 0.0 to 20mg/mL, a linear calibration plot was obtained with a detection limit of 0.98 mg/mL.

Safety evaluation of tea (Camellia sinensis (L.) O. Kuntze) flower extract: assessment of mutagenicity, and acute and subchronic toxicity in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Tea (Camellia sinensis (L.) O. Kuntze, Theaceae) flowers possess many physiological functions and have been used in traditional medicines for deodorization, skin care, cough suppressant and expectorant in China. However, there is a little information about its possible toxicity. AIM OF THE STUDY: The present investigation was carried out to evaluate the safety of tea flower extract by mutagenicity and acute and subchronic toxicity studies. MATERIALS AND METHODS: Mutagenicity of tea flower extract was evaluated by the Ames test in Salmonella typhimurium strains TA97, TA98, TA100 and TA102 at concentrations of 0.008, 0.04, 0.2, 1.0, 5.0 mg/plate. In the acute toxicity study, Sprague-Dawley rats were administered a single dose of 12.0 g/kg of body weight by gavage, and were monitored for 14 days. In the subchronic toxicity study, tea flower extract was administered by gavage at doses of 1.0, 2.0 and 4.0 g/kg body weight daily for 13 weeks to Sprague-Dawley rats. RESULTS: In the Ames test, there was no mutagenic effect of tea flower extract (up to 5.0 mg/plate) towards four tested strains (TA97, TA98, TA100, TA102), with or without metabolic activation (S9). In the acute toxicity study, all animals gained weight and appeared active and normal, so the LD(50) value must be >12.0 g/kg body weight. In the subchronic toxicity study, no dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or pathologic lesions were observed. CONCLUSION: These results indicate that tea flower extract does not possess mutagenic potential, and that both acute and subchronic toxicity towards animals is very low. A no-observed adverse-effect level (NOAEL) for tea flower extract is 4.0 g/kg bw/day for rats under the conditions of this study.

Capillary electrophoresis with electrochemiluminescence detection for simultaneous determination of proline and fleroxacin in human urine.

The content of free proline (Pro) in body fluids is a biological parameter for patients with renal insufficiency and chronic uraemia. Fleroxacin (FLX) must be used cautiously because of adverse reactions. Its dosage must be adjusted according to the degree of renal insufficiency. In a clinical setting the simultaneous determination of Pro and FLX in body fluids is necessary for the rational utilization of FLX. A capillary electrophoresis (CE) method based on electrochemiluminescence (ECL) detection with Ru(bpy)(3) (2+) was developed for the simultaneous determination of Pro and FLX in human urine. Parameters related to separation and detection were investigated and optimized. The most favourable resolution and high sensitivity were obtained using a 15 mM phosphate buffer at pH 9.6 with the detection potential at 1.15 V. Under optimized conditions, the standard curves were linear in the range of 0.1-80 microg/mL for Pro and 0.1-100 microg/mL for FLX. Detection limits(3sigma) of 0.3 ng/mL for FLX and 0.02 microg/mL for Pro were obtained. Relative standard derivations (RSDs) of the ECL intensity and the migration time were 3.2% and 0.9% for 4 microg/mL Pro and 3.7% and 1.2% for 4 microg/mL FLX, respectively. The recoveries were in the range of 94.8-99.6% for Pro with RSDs of 2.8%-3.6% and 94.7-97.8% for FLX with RSDs of 2.9%-3.7%. The proposed method was successfully applied to determine the amounts of Pro and FLX in human urine.