Determining Potential Invasion of Kudzu Bug (Megacopta cribraria) in North and South America and Estimating Its Invasion Dynamics with Geopolitical-Unit Level Records

Biological invasions have put growing threats on ecosystems and human society, exacerbate effects of climate change, and cause economic loss globally. Modeling invasion risk and processes of pest species are essential for early prediction and warning and are increasingly used for detection and control of invasion outbreaks. Kudzu bug, Megacopta cribraria (F.), native to Asia, has become a pest in both agricultural and urban areas since its initial discovery in the United States (U.S.) in 2009. As the establishment of kudzu bug is relatively new in the U.S., its potential invasion risk in the Americas, spread dynamics, and factors that may impact its spread, are not well understood. Thus, this research was intended to address these gaps. This project also evaluated methods that can better estimate invasion risk and dynamics. Findings of this research can guide management of kudzu bug and also provide guidance on approaches to estimate invasion risk and dynamics. High invasion risk of kudzu bug was predicted by species distribution models (SDMs) in eastern U.S., Central America, and central South America. Kudzu bugs generally inhabit warm (annual mean temperature around 15℃) and humid (annual mean precipitation around 1300mm) regions. Due to non-adaptive niche shift, kudzu bugs occupied different environmental conditions between the native and invaded ranges. Using kudzu bug as a case study and seven SDMs, non-adaptive niche shift does not necessarily challenge transferability of SDMs. Additionally, the spatial range where PAs are extracted can significantly impact both interpolation and transferability of SDMs. Geopolitical-unit invasion record is capable of estimating invasion dynamics. Boundary displacement methods have the best estimations for both overall rate and spread dynamics. However, for spread without a clear infestation outline, area-based regression methods can be good alternatives for estimating invasion dynamics. The spread rate of kudzu bug was 76 km/year during 2010-2016, however, the rate varied largely among different regions (45 - 144 km/year). The availability of host plants seemed to play an important role on the spread of kudzu bug in the southern region, while the low temperature in January was the most important factor in the northern region

Identification and characterization of CBL and CIPK gene families in canola (Brassica napus L.)

BACKGROUND: Canola (Brassica napus L.) is one of the most important oil-producing crops in China and worldwide. The yield and quality of canola is frequently threatened by environmental stresses including drought, cold and high salinity. Calcium is a ubiquitous intracellular secondary messenger in plants. Calcineurin B-like proteins (CBLs) are Ca(2+) sensors and regulate a group of Ser/Thr protein kinases called CBL-interacting protein kinases (CIPKs). Although the CBL-CIPK network has been demonstrated to play crucial roles in plant development and responses to various environmental stresses in Arabidopsis, little is known about their function in canola. RESULTS: In the present study, we identified seven CBL and 23 CIPK genes from canola by database mining and cloning of cDNA sequences of six CBLs and 17 CIPKs. Phylogenetic analysis of CBL and CIPK gene families across a variety of species suggested genome duplication and diversification. The subcellular localization of three BnaCBLs and two BnaCIPKs were determined using green fluorescence protein (GFP) as the reporter. We also demonstrated interactions between six BnaCBLs and 17 BnaCIPKs using yeast two-hybrid assay, and a subset of interactions were further confirmed by bimolecular fluorescence complementation (BiFC). Furthermore, the expression levels of six selected BnaCBL and 12 BnaCIPK genes in response to salt, drought, cold, heat, ABA, methyl viologen (MV) and low potassium were examined by quantitative RT-PCR and these CBL or CIPK genes were found to respond to multiple stimuli, suggesting that the canola CBL-CIPK network may be a point of convergence for several different signaling pathways. We also performed a comparison of interaction patterns and expression profiles of CBL and CIPK in Arabidospsis, canola and rice, to examine the differences between orthologs, highlighting the importance of studying CBL-CIPK in canola as a prerequisite for improvement of this crop. CONCLUSIONS: Our findings indicate that CBL and CIPK family members may form a dynamic complex to respond to different abiotic or hormone signaling. Our comparative analyses of the CBL-CIPK network between canola, Arabidopsis and rice highlight functional differences and the necessity to study CBL-CIPK gene functions in canola. Our data constitute a valuable resource for CBL and CPK genomics

Mapping Vegetation at Species Level with High-Resolution Multispectral and Lidar Data Over a Large Spatial Area: A Case Study with Kudzu

Mapping vegetation species is critical to facilitate related quantitative assessment, and mapping invasive plants is important to enhance monitoring and management activities. Integrating high-resolution multispectral remote-sensing (RS) images and lidar (light detection and ranging) point clouds can provide robust features for vegetation mapping. However, using multiple sources of high-resolution RS data for vegetation mapping on a large spatial scale can be both computationally and sampling intensive. Here, we designed a two-step classification workflow to potentially decrease computational cost and sampling effort and to increase classification accuracy by integrating multispectral and lidar data in order to derive spectral, textural, and structural features for mapping target vegetation species. We used this workflow to classify kudzu, an aggressive invasive vine, in the entire Knox County (1362 km2) of Tennessee (U.S.). Object-based image analysis was conducted in the workflow. The first-step classification used 320 kudzu samples and extensive, coarsely labeled samples (based on national land cover) to generate an overprediction map of kudzu using random forest (RF). For the second step, 350 samples were randomly extracted from the overpredicted kudzu and labeled manually for the final prediction using RF and support vector machine (SVM). Computationally intensive features were only used for the second-step classification. SVM had constantly better accuracy than RF, and the producer’s accuracy, user’s accuracy, and Kappa for the SVM model on kudzu were 0.94, 0.96, and 0.90, respectively. SVM predicted 1010 kudzu patches covering 1.29 km2 in Knox County. We found the sample size of kudzu used for algorithm training impacted the accuracy and number of kudzu predicted. The proposed workflow could also improve sampling efficiency and specificity. Our workflow had much higher accuracy than the traditional method conducted in this research, and could be easily implemented to map kudzu in other regions as well as map other vegetation species

Dissection of molecular events involved in saul1-mediated autoimmunity

Plant intracellular nucleotide binding and leucine-rich repeat proteins (NB-LRR, NLRs) function as immune receptors to detect microbial pathogens directly or indirectly. Most NLRs guard host proteins that are the direct targets of pathogen effectors. A typical NLR sometimes cooperates with another atypical NLR for effector recognition. Upon effector recognition, plant NLRs oligomerize for defense activation, the mechanism of which is poorly understood. As a positive regulator of plant immunity, E3 ligase SAUL1 is guarded by NLR protein SOC3. The mutant saul1-1 displays seedling lethality from its autoimmunity, which makes it a suitable background for genetic screens. In chapter 2, by using CRISPR/Cas9 gene editing, genetic analysis and biochemical assays, I identified the differential pairings of typical NLR receptor SOC3 with atypical NLR proteins CHS1 or TN2 to guard the homeostasis of the E3 ligase SAUL1. The differential pairing results in autoimmunity with distinct morphological outcomes. SOC3 forms a head-to-head genomic arrangement with CHS1 and TN2, indicative of transcriptional co-regulation. Such cooperative interactions can likely enlarge the recognition spectrum and increase the functional flexibility of NLRs. In chapter 3, SUSA2 and SUSA3 were identified from the saul1-1 suppressor screen. SUSA2 encodes an F-box protein Actin-Related Protein 8 (ARP8) and SUSA3 encodes the chaperone protein HSP90.3. Further characterization showed that susa2-2 only suppresses the autoimmunity mediated by either CHS1-SOC3 or TN2-SOC3 paired NLR proteins, indicating that SUSA2 is specifically involved in NLR protein SOC3-mediated immunity. Moreover, both SUSA proteins are parts of an SCFSUSA2 E3 ligase, forming SCFSUSA2-NLR complex with CHS1-SOC3 or TN2-SOC3 paired NLR proteins. This is the first example of the assembly of plant NLRs into an SCF complex, which likely enables the ubiquitination and degradation/activation of an unknown downstream component to activate defense, a mechanism with remote similarity to mammalian NLR inflammasome activation. Overall, my Ph.D. thesis provides a better understanding of the molecular mechanisms by which NLR immune receptors are activated upon pathogen recognition. Such knowledge will be critical in the future design of pathogen-resistant crops.Science, Faculty ofBotany, Department ofGraduat

SUSA2 is an F-box protein required for autoimmunity mediated by paired NLRs SOC3-CHS1 and SOC3-TN2

Plant NLR immune receptors detect pathogen effectors and oligomerize upon immune activation. Here Liang et al. show that an F-box protein, SUSA2, and SUSA3/HSP90.3 interact with the paired NLRs SOC3-CHS1 and SOC3-TN2 and are required for autoimmunity mediated by these NLRs

Nonlinear Associations between Medical Expenditure, Perceived Medical Attitude, and Sociodemographics, and Older Adults’ Self-Rated Health in China: Applying the Extreme Gradient Boosting Model

Background: although China’s total health expenditure has been dramatically increased so that the country can cope with its aging population, inequalities among individuals in terms of their medical expenditures (relative to their income level) have exacerbated health problems among older adults. This study aims to examine the nonlinear associations between each of medical expenditure, perceived medical attitude, and sociodemographics, and older adults’ self-rated health (SRH); it does so by using data from the 2018 China Family Panel Studies survey. Method: we used the extreme gradient boosting model to explore the nonlinear association between various factors and older adults’ SRH outcomes. We then conducted partial dependence plots to examine the threshold effects of each factor on older adults’ SRH. Results: older adults’ medical expenditure exceeded their overall income. Body mass index (BMI) and personal health expenditure play an essential role in predicting older adults’ SRH outcomes. We found older adult age, physical exercise status, and residential location to be robust predictors of SRH outcomes in older adults. Partial dependence plots of the results visualized the nonlinear association between variables and the threshold effects of factors on older adults’ SRH outcomes. Conclusions: findings from this study underscore the importance of medical expenditure, perceived medical attitudes, and BMI as important predictors of health benefits in older adults. The potential threshold effects of medical expenditure on older adults’ SRH outcomes provide a better understanding of the formation of appropriate medical policy interventions by balancing the government and personal medical expenditure to promote health benefits among older adults

Estimating Invasion Dynamics with Geopolitical Unit-Level Records: The Optimal Method Depends on Irregularity and Stochasticity of Spread

Biological invasions are an ongoing threat for sustainability of ecosystems, and estimating the spread of invasive species is critical for making management decisions. Geopolitical unit-level data (GULD) are often used to estimate invasions due to their wide availability, and researchers had evaluated the abilities of multiple methods to estimate invasion with GULD. However, earlier studies were case based and only addressed limited information on the spread, thus making it inadequate to determine which method to choose to estimate invasions with GULD under various spread scenarios. Here, we conducted a simulation study to (1) evaluate performances of eight methods on estimating expansion patterns, spread rates, and spread dynamics of invasive species with GULD; (2) assess the impact of size and homogeneity of size of geopolitical unit on the estimations by studied methods; (3) evaluate the similarities of all studied methods. Additionally, we presented a concave hull boundary displacement method (Ctd_BD) and an area-based regression method (SqrtNA_R) to estimate spread with GULD. Three regions with varying sizes of counties in the United States (U.S.) were selected to conduct the simulations, and three spread scenarios and three expansion patterns were simulated. AIC, and R2 and root mean square error (RMSE) were used to evaluate the accuracy of methods on estimating expansion pattern, and overall spread rate and spread dynamics, respectively. Correlation coefficient and RMSE were used to assess the similarity of eight methods. We found Ctd_BD and area-based regression methods consistently estimated the right expansion patterns. Boundary displacement and area-based regression methods estimated highly correlated spread rates and dynamics. Distance-based regression methods provided a high accuracy on estimating overall spread rate without long-distance jump dispersal but performed poorly on estimating the spread dynamics. We recommend boundary displacement method, especially Ctd_BD, for estimating spread with GULD, whereas for spread without clear infestation boundaries, distance-based regression can be used to estimate overall spread rate and area-based regression can be used to estimate spread dynamics.Forestry, Faculty ofNon UBCEngineering, School of (Okanagan)ReviewedFacultyResearche

The Mediation Effect of Perceived Attitudes toward Medical Service on the Association between Public Satisfaction with the Overall Medical Service and Self-Rated Health among the General Population in China: A Cross-Sectional Study

This study aimed to examine the association between public satisfaction with the overall medical service and individuals’ self-rated health among 18,852 Chinese adults aged 16–60 years by using data from the 2018 China Family Panel Studies. We further test whether such an association is mediated by perceived attitudes toward the medical service. The logistic regression model is used to explore the association between public satisfaction with the overall medical service and individuals’ self-rated health (SRH) outcomes. Mediation analysis was conducted by using the Karlson–Holm–Breen (KHB) method. We found that public satisfaction with the overall medical service was associated with good SRH. Additional results indicated that the association between public satisfaction with the overall medical service and SRH was significantly mediated by perceived attitudes toward the medical service. The degree of mediation is much larger for individuals’ satisfaction with the level of medical expertise than for trusting in doctors, attitudes toward medical service problems, and the attitude toward the level of the hospital. Targeted medical policy interventions are designed to promote individuals’ perceived attitudes toward the medical service, which might help to improve individuals’ health benefits

Effects and interaction of meteorological factors on hemorrhagic fever with renal syndrome incidence in Huludao City, northeastern China, 2007-2018.

BackgroundHemorrhagic fever with renal syndrome (HFRS), a rodent-borne disease, is a severe public health threat. Previous studies have discovered the influence of meteorological factors on HFRS incidence, while few studies have concentrated on the stratified analysis of delayed effects and interaction effects of meteorological factors on HFRS.ObjectiveHuludao City is a representative area in north China that suffers from HFRS with primary transmission by Rattus norvegicus. This study aimed to evaluate the climate factors of lag, interaction, and stratified effects of meteorological factors on HFRS incidence in Huludao City.MethodsOur researchers collected meteorological data and epidemiological data of HFRS cases in Huludao City during 2007-2018. First, a distributed lag nonlinear model (DLNM) for a maximum lag of 16 weeks was developed to assess the respective lag effect of temperature, precipitation, and humidity on HFRS incidence. We then constructed a generalized additive model (GAM) to explore the interaction effect between temperature and the other two meteorological factors on HFRS incidence and the stratified effect of meteorological factors.ResultsDuring the study period, 2751 cases of HFRS were reported in Huludao City. The incidence of HFRS showed a seasonal trend and peak times from February to May. Using the median WAT, median WTP, and median WARH as the reference, the results of DLNM showed that extremely high temperature (97.5th percentile of WAT) had significant associations with HFRS at lag week 15 (RR = 1.68, 95% CI: 1.04-2.74) and lag week 16 (RR = 2.80, 95% CI: 1.31-5.95). Under the extremely low temperature (2.5th percentile of WAT), the RRs of HFRS infection were significant at lag week 5 (RR = 1.28, 95% CI: 1.01-1.67) and lag 6 weeks (RR = 1.24, 95% CI: 1.01-1.57). The RRs of relative humidity were statistically significant at lag week 10 (RR = 1.19, 95% CI: 1.00-1.43) and lag week 11 (RR = 1.24, 95% CI: 1.02-1.50) under extremely high relative humidity (97.5th percentile of WARH); however, no statistically significance was observed under extremely low relative humidity (2.5th percentile of WARH). The RRs were significantly high when WAT was -10 degrees Celsius (RR = 1.34, 95% CI: 1.02-1.76), -9 degrees Celsius (1.37, 95% CI: 1.04-1.79), and -8 degrees Celsius (RR = 1.34, 95% CI: 1.03-1.75) at lag week 5 and more than 23 degrees Celsius after 15 weeks. Interaction and stratified analyses showed that the risk of HFRS infection reached its highest when both temperature and precipitation were at a high level.ConclusionsOur study indicates that meteorological factors, including temperature and humidity, have delayed effects on the occurrence of HFRS in the study area, and the effect of temperature can be modified by humidity and precipitation. Public health professionals should pay more attention to HFRS control when the weather conditions of high temperature with more substantial precipitation and 15 weeks after the temperature is higher than 23 degrees Celsius

Empirical Analysis of Population Urbanization and Residents’ Life Satisfaction—Based on 2017 CGSS

As the greatest potential of domestic demand, new urbanization shoulders the important mission of improving the living standards of residents. Based on the theory of exploitation, this paper systematically established the theoretical relationships among population urbanization rate, human capital, family capital, and life satisfaction. Through the 2017 China Comprehensive Social Survey of 1940 micro-individuals for empirical analysis, the results show that: (1) the urbanization rate of the core explanatory variable has a significant and robust positive effect on individual life satisfaction and on human capital and family capital; (2) the urbanization rate of the core explanatory variable has a significant positive effect on human capital and family capital; (3) human capital and family capital have significant positive effects on life satisfaction; (4) in the heterogeneity discussion, the male capital accumulation is higher than the female, but life satisfaction is the opposite. With the increase in age, the individuals accumulated the highest human capital and family capital in 26–34 years old and reached the peak in life satisfaction after retirement in 60–83 years old. As far as regional differences are concerned, individual human capital, family capital, and life satisfaction are decreasing from the east to the west. The results of the study will help to establish a healthy and perfect regional urbanization and to enhance the mental health of residents by promoting talent development and advocating family-friendly construction