Developing a Reliable Service System of Charity Donation During the Covid-19 Outbreak

Drawing upon the functional characteristics of blockchain technology, this article envisages the feasibility and reliability of developing a charity donation service system loaded onto blockchain in response to the complex service demands encountered by charity operators due to the Covid-19 epidemic. With blockchain technology's support as the underlying data book, this article focuses on the practical issues of charity donation fund and material allocation, as well as information release and sharing, charity donation organization, and organization self-management. The paper thereby discusses the key technologies in terms of overall structure design, specific service sector, and functional design of the donation service system and further summarizes the operational mechanism of the system as combined with the needs of help-seeking, receiving, and management users. It is argued that all the above proposals have the potential to alleviate the trust crisis of charity services in China in view of low transparency. The paper expects to provide a useful reference for charity business innovation propelled by blockchain technology

A Hierarchical Decision-Making Method with a Fuzzy Ant Colony Algorithm for Mission Planning of Multiple UAVs

Unmanned aerial vehicles (UAVs) received an unprecedented surge of people’s interest worldwide in recent years. This paper investigates the specific problem of cooperative mission planning for multiple UAVs on the battlefield from a hierarchical decision-making perspective. From the view of the actual mission planning issue, the two key problems to be solved in UAV collaborative mission planning are mission allocation and route planning. In this paper, both of these problems are taken into account via a hierarchical decision-making model. Firstly, we use a target clustering algorithm to divide the original targets into target subgroups, where each target subgroup contains multiple targets. Secondly, a fuzzy ant colony algorithm is used to calculate the global path between target subgroups for a single-target group. Thirdly, a fuzzy ant colony algorithm is also used to calculate the local path between multiple targets for a single-target subgroup. After three levels of decision-making, the complete path for multiple UAVs can be obtained. In order to improve the efficiency of a collaborative task between different types of UAVs, a cooperative communication strategy is developed, which can reduce the number of UAVs performing tasks. Finally, experimental results demonstrate the effectiveness of the proposed cooperative mission planning and cooperative communication strategy for multiple UAVs

Analysis of spatio-temporal transmission characteristicsfor H7N9 infection in China

To reveal the temporal and spatial development and evolution of human H7N9 infection in China, based on the statistical data of human H7N9 infection from 2013 to 2017, time series and standard deviation ellipse analysis were performed. Firstly, the epidemic time series was analyzed with month as time unit, and the peak and trough periods of the epidemic were identified. On this basis, the whole epidemic period was divided into stages, and the epidemic change law of each stage was analyzed. Then the standard deviation ellipse is established according to the location of the epidemic cases, and the spread of the epidemic situation is described by the changes of the ellipse center, azimuth and area in each stage. Finally, through the time and space analysis of the three typical areas, the spread law of the epidemic was further verified. The results show that, the high incidence period is from December to May every year, especially in January and February. The proportion of cases in these two months is as high as 51.74%. September of every year is the low point of epidemic situation, which is the dividing point of epidemic spreading stage. During the whole epidemic period, the number of cases increased, decreased, broke out and returned to zero. Spatially, the center of the standard deviation ellipse shifts from Huzhou City to Fuzhou City and Quzhou City, and the coverage area of the ellipse also expands from coastal areas to inland areas. It shows that the early control measures are not effective enough, and the effect of prevention and control is not obvious, which makes the epidemic spread. In the later period, the strict measures had a good effect, and the epidemic situation was effectively controlled. Study the spatio-temporal transmission mechanism of human infection with H7N9, can provide a theoretical and practical reference for the prediction and Prevention of infectious diseases in China

KO^<i>t</i>Bu/DMF-Mediated Hydroalkylation of Alkenes via Benzylic C–H Bond Activation

Catalytic hydroalkylation reaction of alkenes with benzylic hydrocarbons involving t-BuOK/DMF-mediated benzylic C–H bond activation is demonstrated. This direct and operational simple protocol affords a rapid and reliable access to a wide scope of benzylic compounds in good-to-excellent yields. The benzylic C–H's of either activated diarylmethanes (pKa ∼ 32.2) and benzyl thioethers (pKa ∼ 30.8) or inert alkylbenzenes could all act as useful synthetic platforms to be conveniently alkylated under mild reaction conditions

Integrated Metabolomic and Transcriptomic Analysis Reveals That Amino Acid Biosynthesis May Determine Differences in Cold-Tolerant and Cold-Sensitive Tea Cultivars

Cold stress is one of the major abiotic stresses limiting tea production. The planting of cold-resistant tea cultivars is one of the most effective measures to prevent chilling injury. However, the differences in cold resistance between tea cultivars remain unclear. In the present study, we perform a transcriptomic and metabolomic profiling of Camellia sinensis var. “Shuchazao” (cold-tolerant, SCZ) and C. sinensis var. assamica “Yinghong 9” (cold-sensitive, YH9) during cold acclimation and analyze the correlation between gene expression and metabolite biosynthesis. Our results show that there were 51 differentially accumulated metabolites only up-regulated in SCZ in cold–acclimation (CA) and de–acclimation (DA) stages, of which amino acids accounted for 18%. The accumulation of L-arginine and lysine in SCZ in the CA stage was higher than that in YH9. A comparative transcriptomic analysis showed an enrichment of the amino acid biosynthesis pathway in SCZ in the CA stage, especially “arginine biosynthesis” pathways. In combining transcriptomic and metabolomic analyses, it was found that genes and metabolites associated with amino acid biosynthesis were significantly enriched in the CA stage of SCZ compared to CA stage of YH9. Under cold stress, arginine may improve the cold resistance of tea plants by activating the polyamine synthesis pathway and CBF (C-repeat-binding factor)–COR (cold-regulated genes) regulation pathway. Our results show that amino acid biosynthesis may play a positive regulatory role in the cold resistance of tea plants and assist in understanding the cold resistance mechanism differences among tea varieties

Longitudinal associations between multiple mental health problems and suicidal ideation among university students during the COVID-19 pandemic

BACKGROUND: Recent research suggested that COVID-19-related multiple mental health problems were associated with an increased risk for suicidal ideations (SIs), but population-based data demonstrating these associations are scarce. This study aimed to estimate the cumulative effects of psychological risk factors on SIs during the outbreak and remission periods of COVID-19 using a cumulative risk model, as well as sex differences. METHODS: A total of 68,685 college students in China participated in the survey during two phases of the pandemic (T1 and T2). Mental health risks (acute stress, depression, anxiety, insomnia, and obsessive-compulsive symptoms) and sociodemographic characteristics were measured at T1, and SIs were assessed at T1 and T2. Hierarchical regression analysis was used to determine the combined effect of multiple mental health problems on SIs at T1 and T2. RESULTS: The prevalence of SIs increased from the early periods of the COVID-19 pandemic (7.6%) to the later periods (10.0%). Depression was a powerful risk factor for SIs during the COVID-19 pandemic. Individuals with >3 mental risks would be most likely to experience rapidly increasing SIs during the early periods of the COVID-19 pandemic. Sex exerted different effects on the cumulative risk model of SIs. CONCLUSIONS: Interventions, such as mental health education and improving utilization of student support services, should be implemented. There is a crucial need for early intervention and prevention efforts aimed at males with greater than three mental health problems