Search Results (60)

This study investigates the spatiotemporal distribution and evolution of traditional villages in southern Jiangsu Province, China. By integrating historical documents, remote sensing images, and socio-economic statistics, we have applied standard geographic information system (GIS) methods, including kernel density estimation, nearest neighbor analysis, and standard deviation ellipse analysis, to examine the patterns and driving forces behind village formation and transformation. The findings are as follows: (1) The spatial distribution of the villages exhibits a spatial pattern of “peripheral agglomeration and central decline,” with a nearest neighbor index value of 0.84 (z = −2.52, p < 0.05), indicating a significantly clustered distribution. Kernel density analysis revealed high-density zones along the southwestern coast of Taihu Lake and southeastern Dianshan Lake. (2) From the Song to the Qing Dynasty, village migration followed three sequential phases, “stabilizing near water → avoiding risks around water → adapting inland,” showing strong spatiotemporal linkages to climate change and warfare. (3) The density of the villages showed a significant negative correlation with the per capita GDP (Moran’s I = −0.69, p < 0.05; 0.69, p < 0.01) and was positively correlated with the proportion of primary industry. These findings highlight the spatial resilience characteristics of traditional villages under combined natural and socio-economic pressures and provide a theoretical foundation for regional heritage conservation and rural revitalization strategies. Full article

Reducing fertilizer and pesticide use is a crucial path for the green transformation of agricultural production, which has garnered sustained attention in research on sustainable agricultural development. Based on the theoretical analysis, this article analyzes the spatiotemporal evolution characteristics of fertilizer and pesticide usage intensity (FUI and PUI) in the Yangtze River Delta (YRD) over the past 20 years and uses a Two-Way Fixed Effects Model to test their impacts and mechanisms. Findings show that agricultural development in the YRD shows a pattern of specialization and intensification with a significant north–south divide, with zero growth and reduction in fertilizer and pesticide use across the region from 2010 to 2015, but the current FUI and PUI are still nearly three and five times higher than the global average. Over the past 20 years, the FUI is high in the north and low in the south, high in the plains and low in mountainous-hilly areas, and high in suburban areas and low in remote counties. Adversely, the PUI is high in the south and low in the north, high in mountainous-hilly areas and low in plains, and high in suburban areas and low in remote counties. The FUI and PUI of characteristic agricultural areas of fruit, tea, and forestry in southern Anhui and southwestern Zhejiang, as well as the agroecological and facility agriculture clusters in southern Jiangsu and the suburbs of Shanghai, have approached the peak and successfully moved into the new green development stage earlier compared to other areas. In contrast, the grain and oil production plains areas along the Yangtze River, the coast, in northern Anhui, and in northern Jiangsu are relatively lagging behind. The combination of soil, water, light, and heat resource conditions and modes of agriculture production shape the absolute figures of FUI and PUI, and factors such as the level of local economic development and public fiscal expenditure significantly influence the trajectories of spatiotemporal differentiation in the progress of reducing fertilizer and pesticide in the YRD. Full article

The gut microbiota plays important functions in human health and influences immune responses, metabolic processes, and several physiological activities. The modulation of the gut microbiota through dietary interventions has emerged as a promising approach, leading to significant interest in the development of functional foods that provide health benefits. In this context, our study investigated the effects of raspberry juice fermented by Limosilactobacillus fermentum FUA033 on the structure and metabolism of the gut microbiota. We performed 16S rRNA gene sequencing and nontargeted metabolomics analyses to evaluate changes in the microbial composition and metabolite profiles resulting from fermentation. Our findings revealed that fermented raspberry juice considerably increased the gut microbial diversity and promoted the abundance of beneficial genera. Fermentation substantially increased the production of short-chain fatty acids, such as acetate and butyrate, which increased from 30.09 ± 5.23 mmol/L to 43.07 ± 3.31 mmol/L, and from 7.72 ± 1.72 mmol/L to 15.01 ± 1.26 mmol/L, respectively. Metabolomic analyses also showed significant enhancements in amino acid metabolism pathways, particularly those involving tyrosine, arginine, and proline. These results highlight the potential of fermented raspberry juice as a functional food to improve gut health and metabolic functions. Full article

Traditional methods for the construction of intertidal digital elevation models (DEMs) require the integration of long-term multi-sensor datasets and struggle to capture the spatiotemporal variation caused by ocean dynamics. The SWOT (surface water and ocean topography) mission, with its wide-swath interferometric altimetry technology, provides instantaneous full-swath elevation data in a single pass, offering a revolutionary data source for high-precision intertidal topographic monitoring. This study presents a framework for SWOT-based intertidal DEM extraction that integrates data preprocessing, topographic slope map construction, and tidal channel masking. The radial sand ridge region along the Jiangsu coast is analyzed using SWOT L2 LR (Low Resolution) unsmoothed data from July 2023 to December 2024. Multisource validation data are used to comprehensively assess the accuracy of sea surface height (SSH) and land elevation derived from LR products. Results show that the root mean square error (RMSE) of SSH at Dafeng, Yanghe, and Gensha tide stations is 0.25 m, 0.19 m, and 0.32 m, respectively. Validation with LiDAR data indicates a land elevation accuracy of ~0.3 m. Additionally, the topographic features captured by LR products are consistent with the patterns observed in the remote sensing imagery. A 16-month time-series analysis reveals significant spatiotemporal variations in the Tiaozini area, particularly concentrated in the tidal channel areas. Furthermore, the Pearson correlation coefficient for the DEMs generated from SWOT data decreased from 0.94 over a one-month interval to 0.84 over sixteen months, reflecting the persistent impact of oceanic dynamic processes on intertidal topography. Full article

Surf zones are important nursery grounds for fish larvae and juveniles. However, little is known about fish larvae and juveniles in the surf zone along the coast of Jiangsu Province. To describe the species composition of fish larvae and juveniles, monthly collections were conducted at eight stations during the spring tide from February 2024 to January 2025. The fish larvae and juveniles were sampled using a seine net (1m × 4m; 1 mm mesh aperture), with sampling repeated three times at each station per month. A total of 1435 fish larvae and juveniles were collected, belonging to 42 species and 37 genera in 21 families. Almost half of them were postflexion larvae. Gobiidae, with 14 species, was the most diverse family. Based on the index of relative importance (IRI) result, the dominant species was Amoya pflaumi, accounting for 35.33% of the total number of individuals collected. Common species were Mugil cephalus, Amblychaeturichthys hexanema, Tridentiger trigonocephalus, Acanthogobius ommaturus, Mugilogobius abei, Thryssa mystax, Periophthalmus modestus, Sillago sihama, and Mugilogobius myxodermus. All other species were classified as rare. No fish larvae or juveniles were collected in February 2024 and January 2025. The species number, catch per unit effort (CPUE), Margalef’s richness index, Pielou’s evenness index, and Shannon–Wiener diversity index showed similar trends, and significant differences could be found for each parameter among sampling months. The cluster analysis from the ten months (excluding February 2024 and January 2025) indicated a significant seasonal change in the community structure of fish larvae and juveniles. Fish larvae and juveniles were abundant and diverse at one station near an aquaculture tidal flat for seaweed. This study provides essential basic data to support the management and conservation of fishery resources in the surf zone along the coast of Jiangsu Province. Full article

Siltation around the harbour entrance poses significant challenges to the navigational safety and operational stability of coastal ports. Previous research has predominantly focused on sedimentation mechanisms in sandy coastal environments, while studies on silt-muddy coasts remain scarce. This paper investigates the causes of siltation around the entrance of Binhai Port in Jiangsu Province, China, utilising field observation data and a two-dimensional tidal current numerical model, with emphasis on hydrodynamic variations and sediment dynamics. Observations reveal that tidal currents induce sediment deposition in the outer harbour entrance area, whereas pronounced scouring occurs near breakwater heads. During extreme weather events, such as Typhoons Lekima (2019) and Muifa (2022), combined wind–wave interactions markedly intensified sediment transport and accumulation, particularly amplifying siltation at the entrance, with deposition thicknesses reaching 0.5 m and 1.0 m, respectively. The study elucidates erosion–deposition patterns under combined tidal, wave, and wind forces, identifying two critical mechanisms: (1) net sediment transport directionality driven by tidal asymmetry, and (2) a lagged dynamic sedimentary response during sediment migration. Notably, the entrance zone, functioning as a critical conduit for water– sediment exchange, exhibits the highest siltation levels, forming a key bottleneck for navigational capacity. The insights gleaned from this study are instrumental in understanding the morphodynamic processes triggered by artificial structures in silt-muddy coastal systems, thereby providing a valuable reference point for the sustainable planning and management of ports. Full article

Owing to the abundant land resources in the intertidal zone, the central coastal area of Jiangsu Province, China, has implemented large-scale activities such as tidal flat reclamation, aquaculture, and harbor construction, which have strongly affected the local hydrodynamic environment and the evolution of the mudflat. In this study, based on the 1984–2022 multisource remote sensing image data, an enhanced waterline method (EWM) combined with an average slope method (ASM) were adopted to obtain the spatial–temporal evolution characteristics of the continental coastline and intertidal zone in central Jiangsu Province for six typical years, exhibiting the coastal variations at critical year intervals in response to former large-scale coastal development and subsequent coastal zone protection. Results showed that the coastlines significantly advanced toward the sea. The deposited coast moved toward the seaside at an annual rate of 85.91 m, and the reclaimed coast advanced toward the seaside at a yearly rate of 129.25 m, which were dominated by natural siltation and reclamation activities of mudflats. In the past forty years, the coast’s erosion and siltation transition node has gradually moved southward from the Sheyang Estuary to the Simaoyou Estuary. Affected by reclamation and coastal erosion, the most drastic changes in the slope of the erosive intertidal zone occurred in the section from Binhai Port to the Biandan Estuary, ranging from 2‰ to 14‰. The silted coastal section from the Sheyang Estuary to the Xinyang Estuary increased in average slope from 0.89‰ to 2.43‰ as a result of the continuous intensification of erosion. The area of the intertidal mudflat decreased by 47.76% from 1378.59 to 720.11 km², whereas the mean width of the intertidal zone decreased by 48.02%, from 5518.44 m to 2868.36 m. This study provides current situations of the dynamic changes in the muddy coast of the central Jiangsu coast, which could be a comparison and reference for the sustainable development, utilization, and protection of similar muddy coasts globally. Full article

Coastal areas are essential for global ‘blue carbon’ burial, significantly impacting the global carbon cycle. To better understand the carbon burial capacity, impact factors, and response mechanisms of surface sediments in different coastline regions, this study investigated the surface sediments of the Spartina alterniflora vegetation, transition, and bare flat areas along Jiangsu coast in China. The results indicated significant changes in organic carbon (OC), inorganic carbon (IC), and various physicochemical property indicators between the three coastal environments. There were also significant differences in the important impact factors of OC and IC in each region. In areas of vegetation, OC and IC influenced each other, while nitrogen (N), clay, and sand were common impact factors. The pH only had a significant impact on OC. In the bare flat area, the important impact factors of OC and IC were identical: OC/IC, clay, salinity (SAL), and sand. However, the important impact factors of OC and IC in the transition area have undergone significant changes. The important impact factors of OC were N, total phosphorus (TP), total sulfur (TS), SAL, and sand. The partial least squares regression analysis results of IC were poor, and there were no important impact factors. This study refined the spatial distribution patterns and response mechanisms to the important impact factors of carbon in different coastal subregions, providing a basis for accurately evaluating the role of coastal wetlands in mitigating global climate change. Full article

Mycosporine-like amino acids (MAAs) and glyceroglycolipids have promising applications in various fields, but limited research exists on their simultaneous extraction from macroalgae. This study optimized the key parameters (liquid–solid ratio, extraction temperature and extraction time) in the extraction of MAAs and glyceroglycolipids from Ecklonia kurome and Ulva lactuca using single factor and response surface experiments. The yields of MAAs from E. kurome and U. lactuca were 169.71 mg/g and 177.33 mg/g, respectively, while glyceroglycolipids were extracted from the residue with yields of 163.51 mg/g and 213.45 mg/g, respectively. Both extracts showed concentration-dependent antioxidant activities, with the MAAs extracted from U. lactuca demonstrating the strongest effect. The addition of MAA extract to flaxseed oil significantly reduced oxidation rancidity, highlighting its potential as a natural antioxidant for oils. The glyceroglycolipid extract from E. kurome exhibited significant moisture absorption, and a water-retaining agent prepared from this extract showed excellent moisture retention and resistance to high temperatures, freezing, and pressure. A silica gel column chromatography method confirmed the presence of MGDG in the purified glyceroglycolipid extract. These findings suggested that E. kurome and U. lactuca can be converted into high-value-added compounds with potential applications in food, cosmetics, and pharmaceuticals. Full article

The oceanic fronts play an important role in marine ecosystems and fisheries. This study investigates the seasonal variability of sea surface temperature (SST) fronts in Zhoushan and its adjacent seas for the period 1982–2021. The influences of various underlying dynamic processes on the fronts are also discussed. The horizontal gradient of SST is calculated as frontal intensity, and a threshold value of 0.03 °C/km is set to count the frontal frequency. The fronts in Zhoushan and its adjacent seas show significant seasonal variability, with high (0.1 °C/km and 60–90%) and low (0.03 °C/km and 30–60%) frontal activity in winter and summer, respectively. In summer, the fronts along Jiangsu and the north of the Changjiang River Estuary show higher frontal intensity and frequency, which is mainly influenced by the Changjiang diluted water and southerly wind, and fronts around Zhoushan Island are highly related with Zhoushan upwelling. In winter, the fronts strengthen into regular bands offshore and parallel to the coast, which are mainly influenced by coastal currents. Frontal intensity and frequency show a more significant long-term increasing trend in winter than in summer. Full article

Activities, particularly harbor construction, often exert significant and non-negligible impacts on coastal environments. Therefore, it is of great practical importance to quantitatively assess the effects of such construction on the surrounding topography, such as tidal flats. This study focuses on the coast of Jiangsu Binhai Harbor. Using multi-source and multi-temporal remote sensing images, digital elevation models of tidal flats surrounding Binhai Harbor were generated for the years 2013, 2015, and 2017 through the waterline method. A quantitative analysis was conducted utilizing GIS spatial analysis techniques to examine erosion–deposition patterns, contour changes, and typical cross-sectional comparisons. The findings reveal that, although the overall coastline is in a state of erosion, the localized impacts of harbor construction are evident. Between 2013 and 2017, the northern tidal flats experienced overall erosion, whereas deposition occurred near the harbor’s root areas. Compared to 2013–2015, there was a significant decrease in erosion between 2015 and 2017, indicating that the construction of the project had a significant impact on the northern tidal flats. Throughout the five-year study period, the tidal flats within the breakwater underwent continuous adjustment, shifting from being close to the shoreline to being concentrated on both sides of the breakwater. Significant siltation was observed on the inner side of the breakwater at Binhai Harbor between 2015 and 2017, with an increase of 0.86 km² in the area above −2 m. This study demonstrates that remote sensing technology is highly effective in monitoring changes in coastal topography, especially under the influence of human activities. Full article

Since 2007, Ulva prolifera (U. prolifera) originating in northern Jiangsu (NJ) has consistently expanded to the southern coast of the Shandong Peninsula. However, the underlying reasons for the 2007 sudden bloom of U. prolifera on a large scale remain unknown. This study uses remote sensing data from MODIS/AQUA spanning the period 2003–2022 to investigate the sea surface temperature (SST) structure changes in the southern Yellow Sea (SYS) over the past 20 years. The results demonstrate the following. (1) Since 2007, the NJ northward current and the Yangtze estuary warm current have exhibited higher temperatures, earlier northward intrusions, and larger influence areas, leading to a faster warming rate in NJ before mid-May. This rapid increase in SST to a level suitable for early U. prolifera growth triggers large-scale blooms. (2) The change in temperature structure is primarily induced by a prolonged and intense La Niña event in 2007–2008. However, since 2016, under stable global climate conditions, the temperature structure of the SYS has returned to the pre-2007 state, corresponding to a decrease in the scale of U. prolifera blooms. Full article

Carotenoids are tetraterpene compounds acting as precursors to vitamin A, with functions that include protecting eyesight, enhancing immunity, promoting cell growth and differentiation, and providing antioxidative benefits. Lycopene, β-carotene, and astaxanthin are particularly critical for health and have diverse applications in food, health products, and medicine. However, natural carotenoids are encased within cell structures, necessitating mechanical methods to disrupt the cell wall for their extraction and purification—a process often influenced by environmental conditions. Thus, improving the efficiency of carotenoid extraction from natural resources is of great interest. This review delves into the research progress made on the extraction processes, structures, and biological functions of carotenoids, focusing on lycopene, β-carotene, and astaxanthin. Traditional extraction methods primarily involve organic solvent-assisted mechanical crushing. With deeper research and technological advancements, more environmentally friendly solvents, advanced machinery, and suitable methods are being employed to enhance the extraction and purification of carotenoids. These improvements have significantly increased extraction efficiency, reduced preparation time, and lowered production costs, laying the groundwork for new carotenoid product developments. Full article

This study explored the performance and reliability of three predictive models—extreme gradient boosting (XGB), convolutional neural network (CNN), and residual neural network (ResNet)—for determining the moisture content in Porphyra yezoensis using near-infrared (NIR) spectroscopy. We meticulously selected 380 samples from various sources to ensure a comprehensive dataset, which was then divided into training (300 samples) and test sets (80 samples). The models were evaluated based on prediction accuracy and stability, employing genetic algorithms (GA) and partial least squares (PLS) for wavelength selection to enhance the interpretability of feature extraction outcomes. The results demonstrated that the XGB model excelled with a determination coefficient (R²) of 0.979, a root mean square error of prediction (RMSEP) of 0.004, and a high ratio of performance to deviation (RPD) of 4.849, outperforming both CNN and ResNet models. A Gaussian process regression (GPR) was employed for uncertainty assessment, reinforcing the reliability of our models. Considering the XGB model’s high accuracy and stability, its implementation in industrial settings for quality assurance is recommended, particularly in the food industry where rapid and non-destructive moisture content analysis is essential. This approach facilitates a more efficient process for determining moisture content, thereby enhancing product quality and safety. Full article

This study investigates the characteristics of the raindrop size distribution (DSD) for five typhoons that made landfall or passed by Zhejiang on the eastern coast of China, from 2019 to 2022. Additionally, it examines the raindrop shape–slope (µ-Λ) relationship, as well as the local Z-R relationship for these typhoons. The DSD datasets were collected by the DSG1 disdrometer located in Ningbo, Zhejiang Province. Based on rainfall rate (R), the DSD can be categorized into convective and stratiform rainfall types. Some rainfall parameters can also be derived from the DSDs to further analyze the specific characteristics of rainfall. The histograms of the generalized intercept parameter (log₁₀N_w) exhibit negative skewness in both convective and stratiform rainfall, whereas the histograms of the mass-weighted mean diameter (D_m) of raindrops display positive skewness. During typhoon periods on the eastern coast of China, the DSD characteristic was composed of a lower number concentration of small and midsize raindrops (3.42 for log₁₀N_w, 1.43 mm for D_m in the whole dataset) as compared to Jiangsu in eastern China, Tokyo, in Japan, Miryang, in South Korea, and Thiruvananthapuram in south India, respectively. At the same time, the scatter plots of D_m and log₁₀N_w indicate that the convective rain during typhoon periods exhibits characteristics that are intermediate between “maritime-like” and “continental-like” clusters. Additionally, the raindrop spectra of convective rainfall and midsize raindrops in stratiform rainfall are well-represented by a three-parameter gamma distribution. The µ-Λ relation in this region is similar to Taiwan and Fujian, located along the southeastern coast of China. The Z-R relationship for eastern coastal China during typhoons based on filtered disdrometer data is Z = 175.04R^1.53. These results could offer deeper insights into the microphysical characteristics of different rainfall types along the eastern coast of China and potentially improve the accuracy of precipitation estimates from weather radar observations. Full article