Sex plays a role in the construction of epiphytic bacterial communities on the algal bodies and receptacles of Sargassum thunbergii

The community structures of epiphytic bacteria on the surface of macroalgae are closely related to their host algae, but there is a lack of research on the differences between the epiphytic bacterial communities of male and female algae and their reproductive tissues. In this study, high-throughput sequencing was used to compare epiphytic bacterial community structures on the intertidal macroalgae Sargassum thunbergii and their receptacles between male and female samples. The epiphytic bacteria on the male and female algal bodies and receptacles had similar community structures with a large number of shared bacteria, but the samples clearly clustered separately, and the abundances of dominant taxa, specific bacteria, and indicator species differed, indicating that epiphytic bacterial communities differed significantly between the male and female S. thunbergii and their receptacles. In addition, the abundance of many predicted functional genes was significantly different between epiphytic bacteria on male and female algal bodies and receptacles, especially metabolism-related genes, and the abundances of predicted functional genes of epiphytic bacteria were significantly higher on both types of male samples than on female samples. Our study confirmed that the sex of the host algae influenced the epiphytic bacterial community structures on algae and algal reproductive tissues, and this role was mainly related to the host metabolism. The results reveal the role of host plant sex in the formation of epiphytic bacterial communities. These findings are helpful for obtaining an in-depth understanding of the construction mechanism of algae-associated bacteria

Brown Carbon Aerosol in Urban Xi’an, Northwest China: TheComposition and Light Absorption Properties

Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) was found to correlate strongly with both parent polycyclic aromatic hydrocarbons (parent-PAHs, 27 species) and their carbonyl oxygenated derivatives (carbonyl-OPAHs, 15 species) in all seasons (r(2) > 0.61). These measured parent-PAHs and carbonyl-OPAHs account for on average similar to 1.7% of the overall absorption of methanol-soluble BrC, about 5 times higher than their mass fraction in total organic carbon (OC, similar to 0.35%). The fractional solar absorption by BrC relative to element carbon (EC) in the ultraviolet range (300-400 nm) is significant during winter (42 +/- 18% for water-soluble BrC and 76 +/- 29% for methanol-soluble BrC), which may greatly affect the radiative balance and tropospheric photochemistry and therefore the climate and air quality

Mapping Provincial Stocks and Wastes of Passenger-Vehicle Plastics in China Based on Dynamic Material Flow Analysis and GIS: 1985–2019

As a polymer material, plastic is widely used in passenger vehicles for its light weight and low-cost advantages. China has accumulated a large amount of discarded automotive plastic in recent years, which has put increasing pressure on the environment and the recycling industry. A dynamic material flow model for estimating the plastic stock and waste in passenger vehicles was developed. Additionally, geospatial models were used to study the spatiotemporal evolution trend of passenger vehicle plastics. The results show: (1) passenger-vehicle plastic stock and waste in China increased rapidly from 1985 to 2019. By 2019, the passenger-vehicle plastic stock was 36.94 million tons, and the waste amount was 1.64 million tons, of which polypropylene accounted for the greatest proportion, and polyoxymethylene (POM) accounted for the least. (2) The stock and waste of passenger-vehicle plastics showed spatial dependency. (3) The spatial center of plastic waste was located in Henan Province, and the spatial center is shifting from north to south. (4) The GDP and the annual population are the main driving factors of passenger-vehicle plastic waste. This study will improve plastic waste management, resource recovery, and environmental sustainability decisions

Abnormal Ship Behavior Detection Based on AIS Data

With the development of navigation globalization and ship dehumanization, the contradiction between the increasing demand for ship behavior supervision and limited traffic service resources is obvious, and the frequent occurrence of accidents at sea is a problem. The monitoring of abnormal ship behavior is an important link in maritime transportation. With the popularization of the automatic identification system and increasing research in the maritime field, the AIS is widely used in the management of ship static information and the real-time sharing of dynamic information. The generated moving ship trajectory data provide a new opportunity for research into abnormal ship behavior and its detection. In light of the current situation of abnormal ship behavior research, we detected abnormal ship behavior from the point of view of spatial information and thematic information based on moving ship trajectory data. Therefore, this study first modeled the cognition of abnormal ship behavior. Then, based on the cognition of group ship behavior rules, we used a method based on graph structure learning to mine maritime routes from the perspective of ship spatial information. Next, we used Rayda’s criterion to detect the anomalous behavior of ships in space. Then, based on the isolation forest algorithm, we detected and described the abnormal behavior shown by ship thematic information. The experimental results show that the framework proposed in this paper can effectively detect the abnormal behavior of ships

Supplementary material on the effects of elevated pCO2 levels on the extracellular polymer metabolism of Phaeodactylum tricornutum

Supplementary Table S1. Seawater dissolved inorganic carbon characteristics in the LC and HC treatments, before and after partial renewal of the medium in semi-continuous cultures. Total inorganic carbon (DIC), pH, salinity, nutrient concentrations, and temperature were used to derive all other parameters using a CO2 system analyzing software (CO2SYS). DIC, total dissolved inorganic carbon; TA, total alkalinity. Data are shown as the means ± SD (n=3). Supplementary Table S2. Sequencing data quality and sequence read alignment analysis. Raw_reads, original reads; Raw_bases, number of bases in the original sequencing data; Clean_reads, the number of clean reads obtained after filtering; Clean_bases, the number of bases in clean reads after filtering; valid_base, valid base percentage; Q30, the percentage of bases with a Qphred value > 30 as a percentage of the total number of bases; GC, total G + C content in the clean bases as a percentage of the total number of bases. For read mapping analyses: Total reads, the number of reads after sequence filtering (e.g., the clean reads); Total mapped, the number of sequences mapped to the genome; Multiple mapped, the number of sequences with multiple alignment positions on the reference genome; Uniquely mapped, the number of sequences with unique alignment positions on the reference genome; Splice reads: uniquely mapped reads that were segmentally aligned two exons (also known as Junction reads) where non-splice reads show the sequences aligned to the exon with reads mapped in proper pairs and the number of sequences on the double-ended alignment. Supplementary Table S3. RT-qPCR primers and amplification results. Supplementary Table S4. Gene identifiers, abbreviations, and annotations for 115 EPS metabolism-related genes. Supplementary Figure 1. Hierarchical clustering of expression values (mean fragments per kilobase of transcript per million mapped reads; FPKM) among samples for 194 genes encoding carbohydrate-active enzymes in the Phaeodactylum tricornutum genome (http://protists.ensembl.org/Phaeodactylum_tricornutum/Info/Index). The enzymes were identified based on the CArbohydrate-Active enZYmes (CAZy) database. The color scale ranges from saturated red indicating highly expressed genes to saturated blue indicating weakly expressed genes, while white indicates relatively moderate expression. The heatmap was generated using the ComplexHeatmap program (Gu et al., 2016) using k-means clustering with a one minus Pearson correlation distance metric and average linkage method to cluster genes into a dendrogram

Abnormal Ship Behavior Detection Based on AIS Data

With the development of navigation globalization and ship dehumanization, the contradiction between the increasing demand for ship behavior supervision and limited traffic service resources is obvious, and the frequent occurrence of accidents at sea is a problem. The monitoring of abnormal ship behavior is an important link in maritime transportation. With the popularization of the automatic identification system and increasing research in the maritime field, the AIS is widely used in the management of ship static information and the real-time sharing of dynamic information. The generated moving ship trajectory data provide a new opportunity for research into abnormal ship behavior and its detection. In light of the current situation of abnormal ship behavior research, we detected abnormal ship behavior from the point of view of spatial information and thematic information based on moving ship trajectory data. Therefore, this study first modeled the cognition of abnormal ship behavior. Then, based on the cognition of group ship behavior rules, we used a method based on graph structure learning to mine maritime routes from the perspective of ship spatial information. Next, we used Rayda’s criterion to detect the anomalous behavior of ships in space. Then, based on the isolation forest algorithm, we detected and described the abnormal behavior shown by ship thematic information. The experimental results show that the framework proposed in this paper can effectively detect the abnormal behavior of ships

Uncovering the Structural Effect Mechanisms of Natural and Social Factors on Land Subsidence: A Case Study in Beijing

Understanding the effect mechanisms of various factors on land subsidence may help in the development of scientific measures to control land subsidence. Previous studies mainly focused on exploring local effect mechanisms, such as extracting hotspots and analyzing their spatiotemporal distribution characteristics and identifying the interaction mechanisms of the associated factors. However, the scarcely discussed structural effect mechanisms on a small scale suggests a need to further explore the effects on land subsidence. Therefore, in this paper, an analytical framework was proposed to elaborate the structural effect mechanisms of influencing factors on land subsidence. First, the local effect mechanisms were identified using the geographically and temporally weighted regression (GTWR) model, followed by a spatial clustering analysis and the detection of their aggregation pattern using the spatially constrained multivariate clustering (SCMC) model to show the structural mechanisms. Study datasets included the monitoring results of land subsidence during 2003–2010 and the related socioeconomic factors by using synthetic aperture radar (SAR) images from Beijing. Factors such as population, annual average rainfall, underground water, and static load were identified to measure the changes in land subsidence, and all of these had both negative and positive impacts. Among these, the annual average rainfall had the largest coefficient variation range. These four geographically associated factors revealed various spatiotemporal effects on land subsidence in Beijing, showing land subsidence changes resulting from the urbanization process of Beijing during that period