Plants respond to herbivory through sequential induction of cheaper defenses before more costly ones.

Plants encounter natural antagonist threats of varying intensity and respond by activating multiple defense traits. Due to the fitness costs associated with producing defense traits, plants are expected to activate less costly traits first, reserving more costly defenses for potentially more severe damage ("cheaper first hypothesis"), but evidence to date is scarce. Here, we tested this hypothesis by measuring six putative defense traits in the annual plant Ambrosia artemisiifolia.

Soil microbial legacies and drought mediate diversity-invasibility relationships in non-native communities.

High native species diversity generally suppresses non-native invasions, but many ecosystems are now characterized by non-native assemblages that vary in species diversity. How this non-native species diversity affects subsequent invaders and its environmental dependence remain unclear. We conducted a plant-soil feedback experiment.

Pathogenicity and transmission of novel highly pathogenic H7N2 variants originating from H7N9 avian influenza viruses in chickens.

The H7 subtype avian influenza viruses are circulating widely worldwide, causing significant economic losses to the poultry industry and posing a serious threat to human health. In 2019, H7N2 and H7N9 co-circulated in Chinese poultry, yet the risk of H7N2 remained unclear. We isolated and sequenced four H7N2 viruses from chickens, revealing them as novel reassortants with H7N9-derived HA, M, NS genes and H9N2-derived PB2, PB1, PA,NP, NA genes.

Specialist reassociation and residence time modulate the evolution of defense in invasive plants: A meta-analysis.

Invasive plants typically escape specialist herbivores but are often attacked by generalist herbivores in their introduced ranges. The shifting defense hypothesis suggests that this will cause invasive plants to evolve lower resistance against specialists, higher resistance against generalists, and greater tolerance to herbivore damage. However, the duration and direction of selective pressures can shape the evolutionary responses of resistance and tolerance for invasive plants.

[Spatiotemporal Distribution Characteristics of Air Pollution and Health Risks in Key Cities of China].

Based on the monitoring data of five pollutants in 168 key cities under air pollution prevention and control in China from 2015 to 2020, using the MAKESENS model and the aggregate risk index(ARI), this study quantitatively analyzed the spatial and temporal distribution characteristics of air pollution and health risks in China and the six urban agglomerations. The results showed that:① PM pollution was the most serious pollution in Chinese key cities. Only 15% of the cities' six-year average concentrations of PM reached the National Secondary Standard, followed by that of NO; 77% of the cities' six-year average concentrations of NO reached the National Secondary Standard.

[Spatiotemporal Evolution Characteristics of PM-O Compound Pollution in Chinese Cities from 2015 to 2020].

Based on the monitoring data of PM and O concentrations in 333 cities in China from 2015 to 2020, using spatial clustering, trend analysis, and the geographical gravity model, this study quantitatively analyzed the characteristics of PM-O compound pollution concentrations and its spatiotemporal dynamic evolution pattern in major cities in China. The results showed that:① there was a synergistic change in PM and O concentrations. When (PM_mean) ≤ 85 μg·m, for every 10 μg·m increase in (PM_mean), the peak of the mean value of (O_perc90) increased by 9.

Eye tracking metrics of orthopedic surgeons with different competency levels who practice simulation-based hip arthroscopic procedures.

Objective: This study aimed to investigate the feasibility of using eye tracking data to identify orthopedic trainees' technical proficiency in hip arthroscopic procedures during simulation-based training.

Design: A cross sectional study.

Setting: A simulation-based training session for hip arthroscopy was conducted.

A three-dimensional (3D) printed simulator as a feasible assessment tool for evaluating hip arthroscopy skills.

Purpose: The aims of this study were (1) to develop a three-dimensional (3D) printed simulator that facilitates the simulation of surgical skills for portal placement, intra-articular identification of anatomical structures and arthroscope navigation for hip arthroscopy and (2) to concurrently examine the feasibility of using this simulator as an assessment tool to evaluate trainees' surgical competencies.

Methods: A simulator was developed using a combination of medical imaging, computer-aided design, and 3D printing. A cross-sectional study was conducted with 29 participants divided into 3 subgroups (novice, intermediate and experienced).

Dynamic evaluation of the ecological civilization of Jiangxi Province: GIS and AHP approaches.

Faced with the increasingly severe ecological environment, China promotes the construction of ecological civilization vigorously. Therefore, it is of great significance to adopt scientific, effective and comprehensive methods to evaluate development status of ecological civilization. Based on the panel data from 2010 to 2014, this paper employs GIS and AHP methods to dynamically examine the level of ecological civilization construction in Jiangxi Province.

Training surgical skills on hip arthroscopy by simulation: a survey on surgeon's perspectives.

Purpose: The purpose of this study is to investigate the importance of general and specific surgical skills for hip arthroscopy from the perspective of surgeons in China. Concurrently, we intend to identify the preferred type of simulation that would facilitate competency of surgical trainees in performing arthroscopy and reinforce their preparation for carrying out the actual surgical procedure.

Methods: An online survey comprising 42 questions was developed by experts in hip arthroscopy and sent to 3 online communities whose members are arthroscopic surgeons in China.

Exposure Risk of Global Surface O During the Boreal Spring Season.

Unlabelled: Surface ozone (O) is an oxidizing gaseous pollutant; long-term exposure to high O concentrations adversely affects human health. Based on daily surface O concentration data, the spatiotemporal characteristics of O concentration, exposure risks, and driving meteorological factors in 347 cities and 10 major countries (China, Japan, India, South Korea, the United States, Poland, Spain, Germany, France, and the United Kingdom) worldwide were analyzed using the MAKESENS model, Moran' analysis, and Generalized additive model (GAM). The results indicated that: in the boreal spring season from 2015 to 2020, the global O concentration exhibited an increasing trend at a rate of 0.

[Spatial Variation of Surface Ozone Concentration During the Warm Season and Its Meteorological Driving Factors in China].

The concentration of surface ozone (O) in China increased consistently from 2015 to 2018, and became an important air pollutant, followed by particulate matter. This study uses real-time O and meteorological data, obtained in 337 cities in China during the warm seasons (April to September) of 2015 to 2018, to determine the spatial variation of surface O and its meteorological driving factors in major cities in China, via trend analysis, spatial autocorrelation, hotspot analysis, and multi-scale geographically weighted regression (MGWR) modeling. The results show that: ① during the warm season, O concentrations showed a significant growth trend (<0.