Food-delivery behavior under crowd sourcing mobility services

The rapid development of the online food-delivery industry, has led to not only increases in the number of the crowd-sourced shared food-delivery service drivers on our roads, but also growing urban traffic safety management concerns. This study investigates the decision-making behaviors that exist between delivery drivers, their food-delivery platform and their potential impact on traffic safety. Using the evolutionary game theory, stakeholder decision-making behaviors involving traffic safety within the food-delivery industry were analyzed. From our analysis, several behavioral influencers were identified, including penalties for traffic violations, the opportunity cost of delivery drivers complying with traffic rules, the costs associated with risk and strict management approaches, reputation incentives, costs related to the delivery platform being punished, the probability of compliance with traffic rules, and the probability of adopting a strict management approach by the delivery platform. Our study demonstrates that stabilization strategies used by the food service industry differ when the types of government control measures also differ. When the government takes a more aggressive approach to regulation and control, compliance with the traffic rules and the adoption of strict enforcement measures by management are the only evolutionary stability strategies available to food-delivery platforms. As part of a strict management strategy, appropriate compensation or incentive measures should be provided by the distribution platform. Furthermore, the fines given for traffic violations should be increased to create a safer road environment that has fewer traffic accidents involving food-delivery drivers

ASTF: Visual Abstractions of Time-Varying Patterns in Radio Signals

A time-frequency diagram is a commonly used visualization for observing the time-frequency distribution of radio signals and analyzing their time-varying patterns of communication states in radio monitoring and management. While it excels when performing short-term signal analyses, it becomes inadaptable for long-term signal analyses because it cannot adequately depict signal time-varying patterns in a large time span on a space-limited screen. This research thus presents an abstract signal time-frequency (ASTF) diagram to address this problem. In the diagram design, a visual abstraction method is proposed to visually encode signal communication state changes in time slices. A time segmentation algorithm is proposed to divide a large time span into time slices.Three new quantified metrics and a loss function are defined to ensure the preservation of important time-varying information in the time segmentation. An algorithm performance experiment and a user study are conducted to evaluate the effectiveness of the diagram for long-term signal analyses.Comment: 11 pages, 9 figure

Dynamic Evolutionary Analysis of the Impact of Outward Foreign Direct Investment on Green Innovation Heterogeneity—From the Perspective of Binary Innovation

In the current era of increasingly frequent international exchanges and countries’ increasing emphasis on green development, exploring the complex relationship between outward foreign direct investment (OFDI) and green innovation has become an important research topic. Taking the binary innovation perspective as an entry point, this paper is devoted to exploring the heterogeneous impact and dynamic evolution of OFDI on green innovation since China’s accession to the WTO. The purpose is to form a more comprehensive and specific understanding of how OFDI affects green innovation. By sorting out the characteristics of economic development at the early stage of China’s WTO accession and implementation of the “going out” strategy, the period of counter-trend growth of OFDI after the financial crisis, and the “new normal” period of China’s transformation and development, this paper analyzes in detail the impact of OFDI on green innovation and green binary innovation in each stage. According to the study, the coefficients of the effects of OFDI on green innovation in the three stages are 0.214 (fully significant at the 1% level), −0.057 (insignificant), and 0.137 (significant at the 5% level), showing an overall effect of promoting–insignificant–promoting; In addition, the fact that the development orientation of OFDI is different at different stages leads to significant heterogeneity in its impact on green innovation and green binary innovation. The coefficients of OFDI on green exploratory innovation at the three stages are 0.064 (insignificant), −0.107 (significant at 10% level), and 0.099 (significant at 5% level), and the coefficients of OFDI on green exploitative innovation are 0.258 (fully significant at 1% level), −0.036 (insignificant) and 0.142 (significant at 5% level), respectively. The results reveal that OFDI on green binary innovation shifts from focusing on promoting green exploitative innovation to taking green binary innovation into account, and this heterogeneous performance effect matches the development characteristics of each stage. The results of the study show more clearly the association between OFDI and green innovation in China and provide new references for subsequent academic research and management practice

Leymus chinensis Tolerates Mowing Disturbance by Maintaining Photosynthesis in Saline-Alkali Heterogeneous Habitats

Leymus chinensis is a perennial rhizomatous clonal plant with strong tolerance to mowing, grazing, drought, and salt-alkali. However, with patchy soil environment, how mowing affect the photosynthesis of L. chinensis in heterogeneous patches is largely unknown. In this experiment, we tested the effects of mowing intensity (0, 35%, and 70% removal of aboveground biomass) on plant photosynthesis under different heterogeneous patches with different saline-alkali soil. We found that moderate concentrations of salt-alkali under heterogeneous patches have no significant effect on the photosynthesis of L. chinensis. Moderate mowing can maintain photosynthesis under no heterogeneity soil and moderate salt-alkali patch condition. In addition, heavy mowing and high salt-alkali soil under heterogeneous patches both inhibited net photosynthetic rate (PN) and transpiration rate (E), reduced leaf area, and plant height. L. chinensis responded to extreme soil conditions and strong disturbance by increasing water-use efficiency (WUE), reducing relative water content (RWC), and changing stomatal conductance (Gsw). Therefore, our results imply that moderate grazing or mowing can be used to maintain the productivity and economic benefits of grassland when the soil heterogeneous patches with moderate saline-alkali conditions

A Substrate-Activated Efflux Pump, DesABC, Confers Zeamine Resistance to Dickeya zeae

Zeamines are a family of newly identified phytotoxins and potent antibiotics produced by D. zeae EC1. Unlike most bacterial organisms, which are highly sensitive, D. zeae EC1 is tolerant to zeamines, but the mechanisms involved are unknown. Our study showed, for the first time, that a new RND efflux pump, DesABC, is indispensable for D. zeae EC1 against zeamines. We found that the DesABC efflux pump was zeamine specific and appeared to be conserved only in the Dickeya species, which may explain the high potency of zeamines against a wide range of bacterial pathogens. We also showed that expression of DesABC efflux system genes was induced by zeamines. These findings not only provide an answer to why D. zeae EC1 is much more tolerant to zeamines than other bacterial pathogens but also document a signaling role of zeamines in modulation of gene expression.Zeamines are a family of polyamino phytotoxins produced by Dickeya zeae EC1. These phytotoxins are also potent antibiotics against a range of microorganisms. To understand how D. zeae EC1 can protect itself from the antimicrobial activity of zeamines, we tested whether the ABC transporter genes within the zms (zeamine synthesis) gene cluster were related to zeamine resistance. Our results ruled out the possible involvement of these ABC transporters in zeamine resistance and instead unveiled an RND (resistance-nodulation-cell division) efflux pump, DesABC, which plays an important role in zeamine resistance in D. zeae EC1. The desAB genes are located next to the zms gene cluster, but desC is at a distant location in the bacterial genome. Null mutation of the desABC genes in a zeamine-minus derivative of strain EC1 led to about an 8- to 32-fold decrease in zeamine tolerance level. This efflux pump was zeamine specific and appeared to be conserved only in Dickeya species, which may explain the high potency of zeamines against a wide range of bacterial pathogens. Significantly, expression of the desAB genes was abolished by deletion of zmsA, which encodes zeamine biosynthesis but could be induced by exogenous addition of zeamines. The results suggest that sophisticated and coordinated regulatory mechanisms have evolved to govern zeamine production and tolerance. Taken together, these findings documented a novel signaling role of zeamines and the first resistance mechanism against zeamines, which is a family of potent and promising antibiotics against both Gram-positive and Gram-negative bacterial pathogens

Gram-negative bacteria resist antimicrobial agents by a DzrR-mediated envelope stress response

Background: Envelope stress responses (ESRs) are critical for adaptive resistance of Gram-negative bacteria to envelope-targeting antimicrobial agents. However, ESRs are poorly defined in a large number of well-known plant and human pathogens. Dickeya oryzae can withstand a high level of self-produced envelope-targeting antimicrobial agents zeamines through a zeamine-stimulated RND efflux pump DesABC. Here, we unraveled the mechanism of D. oryzae response to zeamines and determined the distribution and function of this novel ESR in a variety of important plant and human pathogens. Results: In this study, we documented that a two-component system regulator DzrR of D. oryzae EC1 mediates ESR in the presence of envelope-targeting antimicrobial agents. DzrR was found modulating bacterial response and resistance to zeamines through inducing the expression of RND efflux pump DesABC, which is likely independent on DzrR phosphorylation. In addition, DzrR could also mediate bacterial responses to structurally divergent envelope-targeting antimicrobial agents, including chlorhexidine and chlorpromazine. Significantly, the DzrR-mediated response was independent on the five canonical ESRs. We further presented evidence that the DzrR-mediated response is conserved in the bacterial species of Dickeya, Ralstonia, and Burkholderia, showing that a distantly located DzrR homolog is the previously undetermined regulator of RND-8 efflux pump for chlorhexidine resistance in B. cenocepacia. Conclusions: Taken together, the findings from this study depict a new widely distributed Gram-negative ESR mechanism and present a valid target and useful clues to combat antimicrobial resistance.Published versionThis study is supported by the National Natural Science Foundation of China (32000085, U22A20480, 32072450, and 31972230), Key Realm R&D Program of Guangdong Province (2018B020205003, 2020B020209001), Guangdong Basic and Applied Basic Research Foundation (2020A1515110465, 2020A1515011534), Guangzhou Science and Technology Plan (201804020066, 202102080488), Guangdong Forestry Science and Technology Innovation Project (2020KJCX009), and Natural Science Foundation of Anhui Province (2108085QC118)

Isolation, Characterization, and Transcriptome Analysis of an ISKNV-Like Virus from Largemouth Bass

Largemouth bass (Micropterus salmoides) is an important commercial fish farmed in China. Challenges related to diseases caused by pathogens, such as iridovirus, have become increasingly serious. In 2017, we detected iridovirus-infected diseased largemouth bass in Zunyi, Guizhou Province. The isolated virus was identified as an infectious spleen and kidney necrosis virus (ISKNV)-like virus (ISKNV-ZY). ISKNV-ZY induces a cytopathic effect after infecting mandarin fish brain (MFB) cells. Abundant hexagonal virus particles were observed in the cytoplasm of ISKNV-ZY-infected MFB cells, using electron microscopy. The whole genome of ISKNV-ZY contained 112,248 bp and 122 open reading frames. Phylogenetic tree analysis showed that ISKNV-ZY was most closely related to BCIV, indicating that it is an ISKNV-like megalocytivirus. ISKNV-ZY-infected largemouth bass started to die on day six and reached a death peak on days 7–8. Cumulative mortality reached 100% on day 10. Using RNA sequencing-based transcriptome analysis after ISKNV-ZY infection, 6254 differentially expressed unigenes (DEGs) were identified, of which 3518 were upregulated and 2673 downregulated. The DEGs were associated with endocytosis, thermogenesis, oxidative phosphorylation, the JAK-STAT signaling pathway, the MAPK signaling pathway, etc. These results contribute to understanding the molecular regulation mechanism of ISKNV infection and provide a basis for ISKNV prevention