Exploring the key factors affecting the seasonal variation of phytoplankton in the coastal Yellow Sea

Marine phytoplankton play crucial roles in the ocean’s biological pump and have great impacts on global biogeochemical cycles, yet the knowledge of environmental variables controlling their seasonal dynamics needs to be improved further, especially in the coastal ecosystems. In order to explore the determinants affecting the seasonal variation of phytoplankton, here we conducted three surveys during spring, summer and autumn along the coastal Yellow Sea. Among the phytoplankton community, 49 species of diatoms and 9 species of dinoflagellates were observed in spring, 63 species of diatoms and 10 species of dinoflagellates in summer, and 62 species of diatoms and 11 species of dinoflagellates in autumn. These results thus suggested that there were obvious differences in the number of species across the three seasons, of which diatoms were the most diverse group, followed by dinoflagellates. Additionally, diatoms were the most dominant species of the phytoplankton community and varied largely during different seasons. According to the redundancy analysis, the abundance of phytoplankton community was mainly related to water temperature and dissolved inorganic nitrogen (DIN) during the three seasons, indicating that water temperature and DIN could be the key factors controlling the seasonal variability of phytoplankton community along the coastal Yellow Sea. Also, significant correlations were observed between phytoplankton abundance and heavy metals Zn, As, and Hg during the three seasons, suggesting that these metals also had potential influences on the seasonal dynamics of phytoplankton community in the coastal Yellow Sea

New insights into the impact of polystyrene micro/nanoplastics on the nutritional quality of marine jacopever (Sebastes schlegelii)

Microplastics (MPs) and nanoplastics (NPs) are ubiquitous in the marine environments due to the wide use and mismanagement of plastics. However, the effect of MPs/NPs on the nutrition quality of economic species is poorly understood, and their underlying mechanisms remained unclear. We therefore investigated the impacts of polystyrene MPs/NPs on the nutrition composition of marine jacopever Sebastes schlegelii from the perspective of assimilation and metabolism. Results showed that NPs reduced more nutrition quality than MPs. Despite no notable impact on intestinal microbiota function, MPs/NPs influenced the assimilation of fish through intestinal damage. Furthermore, NPs induced greater damage to hepatocyte metabolism than MPs, caused by hepatocyte uptake through membrane protein pumps/channels and clathrin/caveolin-mediated endocytosis for NPs, while through phagocytosis/pinocytosis for MPs. NPs triggered more cell apoptosis signals in Ferroptosis and FoxO signaling pathways than MPs, destroying mitochondria structure. Compared with MP treatments, a significant upregulation of genes (PRODH and SLC25A25A) associated with the electron transfer chain of mitochondria was detected in the NP treatments, influencing the tricarboxylic acid cycle and interfering with liver metabolism of proteins, fatty acid, glycerol phospholipids, and carbohydrates. This work provides new insights into the potential impacts of MPs/NPs on the quality and safety of seafood.publishedVersio

A study of HIV/AIDS related knowledge, attitude and behaviors among female sex workers in Shanghai China

<p>Abstract</p> <p>Background</p> <p>China is currently facing a rapid and widespread increase in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). The activities of female sex workers (FSWs) have contributed to the mounting epidemic of HIV/AIDS and other sexually transmitted diseases (STDs). Therefore, this study aimed to assess the HIV/AIDS-related knowledge, attitude and risk behaviors among FSWs operating in Shanghai China.</p> <p>Methods</p> <p>A cross-sectional study was conducted in five districts of Shanghai, including three suburbs and two downtown locales. We adopted a cluster randomized sampling method to obtain ten geographic sites which consisted of one or more communities/villages proximal to a location where FSWs were accessible. A total of 324 FSWs from 109 Xitou Fang, massage parlors and hair salons who explicitly provided sexual services were enrolled in the study. Each participant completed a questionnaire survey and interview aimed to collect information on the individual's knowledge, attitude, and behaviors associated with risk for HIV/AIDs.</p> <p>Results</p> <p>The overall correct answer rate of HIV/AIDS-related knowledge was 60.8%, and the knowledge of FSWs from downtown areas was significantly higher than those from suburban areas (<it>P </it>< 0.05). The percentage of FSWs who reported having experiences in commercial sexual services without the use of condoms was 33.6%. Condom slippage or breakage was reported as having occurred at least once by 51.2% of the FSWs. FSWs from suburban areas were found to more often engage in high-risk behaviors, including oral and anal sex, than those from downtown areas (<it>P </it>< 0.001). Many of the FSWs (65.7%) reported having non-client sexual partners (most were identified as boyfriends or husbands); however, condom usage with these partners were lower (34.3%).</p> <p>Conclusions</p> <p>Based on the findings from our survey, we advise that promotion of HIV/AIDS-related knowledge be targeted towards FSWs in Shanghai, especially those operating in the suburbs. HIV prevention efforts, such as urging constant condom usage with both clients and steady partners, should be sustained and reinforced among the female sex workers population.</p

Effects of plant cover on properties of rhizosphere and inter-plant soil in a semiarid valley, SW China

Plant establishment is widely recognized as an effective way to prevent soil erosion in arid and semiarid ecosystems. Artemisia gmelinii, a pioneering species in many degraded ecosystems in China, is effective in improving soil properties and controlling runoff and soil loss, but mechanisms underlying soil improvement are not well understood. We therefore investigated how the presence and cover of A. gmelinii affect soil physico-chemical properties and soil microbial communities in differently sized soil aggregates in the rhizosphere and inter-plant soil in the Upper Minjiang River arid valley of China. We found that A. gmelinii presence significantly improved soil quality in terms of soil structure, water content, aggregate-associated carbon and nutrients, and soil microbial biomass and activities. Interestingly, also inter-plant soils were strongly influenced by adjacent-plant-cover, showing enhanced soil organic carbon, total carbon, nitrogen and phosphorus, and reduced soil bulk density and pH with increasing A. gmelinii cover in plots. In turn, the A. gmelinii-induced changes in inter-plant soil properties could explain a large part of the observed variation in microbial biomass, carbon and nitrogen. Importantly, effects of the presence and cover of A. gmelinii on soil properties were mostly specific for particular aggregate size classes. Specifically, A. gmelinii significantly increased P accumulation only in small macroaggregates (250-2000 um) illustrating the importance of this aggregate class in terms of plant-mediated phosphorus accumulation, critical for P uptake in this P limited area. Our results thus indicate that A. gmelinii not only improves soil physical and microbial conditions in its rhizosphere but also in inter-plant soil, and that increasing A. gmelinii cover has the potential to reduce runoff and soil loss and to promote revegetation

A Low-Cost Electrochemical Method for the Determination of Sulfadiazine in Aquaculture Wastewater

As the concept of green development spreads worldwide, environmental protection awareness for production and life has been continuously strengthened. Antibiotic residues in aquaculture wastewaters aggravate environmental pollution and threaten human health. Therefore, the detection of residual antibiotics in wastewater is crucial. In this paper, a new, simple, and low-cost method based on the glassy carbon electrode electrochemical sensor for the detection of sulfadiazine in aquaculture wastewater was developed without using complex materials to modify the electrode surface, to detect sulfadiazine which electrochemically oxidizes directly. The electrochemical performance of the sensor was studied and optimized with differential pulse voltammetry and cyclic voltammetry in the three-electrode system. The optimal electrolyte was acetic acid-sodium acetate buffer, and the optimal pH was 4.0. Finally, based on the optimized conditions, the newly established method showed satisfactory results for detecting sulfadiazine in aquaculture wastewater. The concentration of sulfadiazine and the peak current intensity showed a linear relationship in the range of 20 to 300 &mu;mol/L, and the limit of detection was 6.14 &mu;mol/L, the recovery rate of standard addition was 87&ndash;95%, with satisfactory reproducibility and low interference

Research status and Prospect of integrated energy system collaborative control based on energy Internet

As the only way to build the energy Internet, the key and difficult point of integrated energy system is to plan it reasonably and efficiently. This paper analyzes and summarizes the basic strategy, key technologies, control difficulties and influencing factors of integrated energy system control, summarizes the existing problems at home and abroad, and summarizes the content framework and control model of general integrated energy system control covering the source, network, load and storage links in a comprehensive way based on the latest research progress. According to the latest research progress, the paper analyzes the current control schemes, and concludes the development trend of the current integrated energy system collaborative control, makes a reasonable outlook on the future, and provides a way of thinking for people to study the integrated energy system in the future

Graphene Oxide Molecularly Imprinted Polymers as Novel Adsorbents for Solid-Phase Microextraction for Selective Determination of Norfloxacin in the Marine Environment

In this study, a novel sample pretreatment strategy of solid-phase microextraction using graphene oxide molecularly imprinted polymers as adsorbents coupled with high-performance liquid chromatography was developed to detect norfloxacin in the marine environment. As a carrier, the imprinted polymers were synthesized by precipitation polymerization with graphene oxide. Compared with graphene oxide non-imprinted polymers, the graphene oxide molecularly imprinted polymers exhibited higher adsorption capacity towards norfloxacin. The synthesized polymeric materials were packed into a molecularly imprinted solid-phase microextraction cartridge, and critical parameters affecting the extraction process were optimized. Under the optimized molecular imprinted solid-phase microextraction condition, the proposed method was applied to the analysis of norfloxacin for seawater and fish with satisfactory recovery (90.1–102.7%) and low relative standard deviation (2.06–5.29%, n = 3). The limit of detection was 0.15 μg L−1 and 0.10 μg kg−1 for seawater and fish, respectively. The study revealed that the proposed molecularly imprinted solid-phase microextraction represents an attractive sample pretreatment strategy for the analysis of norfloxacin in the marine environment

Changes and Influencing Factors of the Zooplankton Community in the Eutrophic Waters of Jinghai Bay

Coastal ecosystems are critical to biodiversity owing to the strong interactions between terrestrial and marine environments. Zooplankton are important secondary producers and major drivers of biological pumps in marine ecosystems and changes in their communities may affect coastal ecosystems. Therefore, it is important to comprehensively evaluate the effects of various environmental factors on the changes in zooplankton communities in coastal ecosystems. Previous research has been limited to a single study on the environmental quality or biological communities in Jinghai Bay, and there have been no relevant reports on the analysis and evaluation of the relationship between changes in zooplankton communities and environmental factors in Jinghai Bay. To study the relationship between zooplankton communities and environmental factors in Jinghai Bay, four survey voyages of environmental factors and zooplankton were conducted in May (spring) and August (summer) from 2021 to 2022. Redundancy analysis (RDA) and Pearson correlation analysis were used to explore the effects of environmental factors on dominant zooplankton species and communities. The results showed that the degree of eutrophication in Jinghai Bay increased significantly from 2021 to 2022, particularly during the summer of 2022 (average eutrophication index EI > 200). The distribution of EI showed that the EI was higher in estuaries in the surveyed sea area, and the source of nutrients may be river-diluted water. In addition, there were significant seasonal changes in salinity, especially in the summer of 2022 (the average salinity dropped to 12.06). The average zooplankton abundance in 2021 was higher than that in 2022, and in the summer of 2022, when eutrophication was most severe, the average zooplankton abundance dropped to 54.07 ind./m3. However, during the summer of 2022, which had the lowest abundance, the biomass did not show the same proportion of decline, which requires further study. In addition, Principal Co-ordinates Analysis (PCoA) revealed significant differences between the 2022 summer zooplankton communities and the previous three voyages. A total of 47 species of 10 groups of zooplankton were identified during the four voyages, among which copepods were the most dominant species in spring and pelagic larvae in summer. Acartia pacifica and Zoea larva (Brachyura) were the dominant species on all four voyages. From 2021 to 2022, the dominance of Acartia pacifica showed a continuously decreasing trend. In the spring and summer of 2022, Zoea larva (Brachyura) became the dominant species in the sea area, but the relative abundance and dominance of Zoea larva (Brachyura) decreased in summer. The number of dominant species, across both years, reached an apex (7 species) in the summer of 2022. The interannual and seasonal variation trends of the zooplankton communities, as shown by the Shannon-Wiener diversity index (H′) and Pielou's evenness index (J), in Jinghai Bay were similar. In terms of seasonal changes, H′ and J in spring 2021 were higher than those in summer. In 2022, the opposite trend was observed, with H′ and J higher in summer than in spring. From the perspective of inter-annual change, both the H′ and J in 2022 were higher than those in 2021. Generally, from 2021 to 2022, the trend of change of zooplankton biodiversity in the Jinghai Bay area gradually increased. RDA showed that the dominant species, Acartia pacifica and Zoea larva (Brachyura), which appeared in all four surveys, were negatively correlated with EI during spring and summer in both years. Eurytemora pacifica, which only appeared in spring, was positively correlated with salinity during the spring of the two years, whereas in the summer of 2022, the newly emerged dominant species Penilia avirostris, Gammaridae, and Schmackeria poplesia were positively correlated with EI, dissolved inorganic phosphate (DIP), and chemical oxygen demand (COD), and negatively correlated with salinity. Pearson correlation analysis showed that EI was negatively correlated with the abundance of zooplankton in all four voyages, positively correlated with abundance and biomass in spring, and negatively correlated with abundance and biomass in summer. In addition, Pearson correlation analysis showed that salinity had an impact on the zooplankton diversity index. Based on the correlation analysis of the RDA and Pearson correlation coefficient, eutrophication was found to be the main environmental factor affecting the community structure and abundance of zooplankton in Jinghai Bay, and salinity affected the seasonal variation in zooplankton. In addition, through PCoA analysis and comparison of data from 2021 and 2022, it was found that occasional events, such as typhoons, may also be an important reason for changes in the zooplankton community. The results of this study will be conducive to a follow-up study of the ecosystem of Jinghai Bay and understanding the factors controlling the dynamics of its zooplankton community, which in turn will contribute to the scientific management of the ecological environment of Jinghai Bay and an in-depth understanding of the mechanisms of zooplankton community change in the bay