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The temporal-spatial distribution of the carbon and nitrogen contents and their isotopic compositions of suspended matter and sediments from the Yellow River estuary reach (YRER), the estuary to the offshore area were measured to identify the source of organic matter. The higher relative abundances of suspended and sedimentary carbon and nitrogen (POC, TOC, PN and TN) in the offshore marine area compared to those of the riverine and estuarine areas may be due to the cumulative and biological activity impact. The organic matter in surface sediments of YRER, the estuary and offshore area of Bohai Sea is basically the mixture of continental derived material and marine material. The values of δ 13 C sed fluctuate from values indicative of a land source (− 22.50‰ ± 0.31) to those indicative of a sea source (− 22.80‰ ± 0.38), which can be attributed to the fine particle size and decrease in terrigenous inputs to the offshore marine area. Contrary to the slight increase of POC and PN during the dry season, TOC and TN contents of the surface sediments during the flood season (October) were higher than those during the dry season (April). The seasonal differences in water discharge and suspended sediment discharge of the Yellow River Estuary may result in seasonal variability in TOC, POC, TN and PN concentrations in some degree. Overall, the surface sediments in the offshore area of Bohai Sea are dominated by marine derived organic carbon, which on average, accounts for 58–82% of TOC when a two end-member mixing model is applied to the isotopic data. [ABSTRACT FROM AUTHOR]

It is well known that accurate estimation of the loop delay between the input and output feedback signals is the key to behavioral modeling and digital predistortion of power amplifier. Nevertheless, most of the traditional loop‐delay compensation algorithms have the disadvantage of high computational complexity. For the purpose of solving this problem, a loop‐delay estimation algorithm based on sliding window has been proposed in this paper, where the first derivative characteristic of the signal is employed to evaluate the correlation between the input and output feedback signals. The simulation and experiment are carried out with different bandwidth signals in this paper. The results show that the proposed algorithm and the traditional cross‐correlation‐based method could align the input and output feedback signals successfully. But in terms of resource consumption, the proposed algorithm could reduce the multiplier nearly by 100% and the adder by approximately 93.2%. [ABSTRACT FROM AUTHOR]

Simple Summary: In commercial duck farming, the photoperiod is a crucial farming parameter that can influence physiological and health indicators. Among these indicators, duck activeness, which is directly affected by the photoperiod, is one of the most intuitive and currently a hot research topic in the field of animal welfare. However, there are existing limitations in the calculation methods for activeness, which often focus on relationships between adjacent frames, neglecting medium- to long-term features and sometimes lacking intuitiveness. Additionally, the relationship between duck activeness and the photoperiod has not been clearly defined, making it challenging to provide practical guidance for production. This study introduces a duck activeness estimation method based on machine vision technology. It involves tracking the movement of group-raised ducks over a 6 min period. The average displacement of all ducks within each frame is used as an indicator to measure activeness, resulting in more accurate results. This method is applied to assess duck activeness under different photoperiods, and the experimental results are analyzed to determine the most suitable lighting cycle for duck farming, demonstrating the superiority of the model. The proposed method and the conclusions regarding the optimal photoperiod provide both a methodology and data support to enhance duck breeding and farming efficiency. The regulation of duck physiology and behavior through the photoperiod holds significant importance for enhancing poultry farming efficiency. To clarify the impact of the photoperiod on group-raised duck activeness and quantify duck activeness, this study proposes a method that employs a multi-object tracking model to calculate group-raised duck activeness. Then, duck farming experiments were designed with varying photoperiods as gradients to assess this impact. The constructed multi-object tracking model for group-raised ducks was based on YOLOv8. The C2f-Faster-EMA module, which combines C2f-Faster with the EMA attention mechanism, was used to improve the object recognition performance of YOLOv8. Furthermore, an analysis of the tracking performance of Bot-SORT, ByteTrack, and DeepSORT algorithms on small-sized duck targets was conducted. Building upon this foundation, the duck instances in the images were segmented to calculate the distance traveled by individual ducks, while the centroid of the duck mask was used in place of the mask regression box's center point. The single-frame average displacement of group-raised ducks was utilized as an intuitive indicator of their activeness. Farming experiments were conducted with varying photoperiods (24L:0D, 16L:8D, and 12L:12D), and the constructed model was used to calculate the activeness of group-raised ducks. The results demonstrated that the YOLOv8x-C2f-Faster-EMA model achieved an object recognition accuracy (mAP@50-95) of 97.9%. The improved YOLOv8 + Bot-SORT model achieved a multi-object tracking accuracy of 85.1%. When the photoperiod was set to 12L:12D, duck activeness was slightly lower than that of the commercial farming's 24L:0D lighting scheme, but duck performance was better. The methods and conclusions presented in this study can provide theoretical support for the welfare assessment of meat duck farming and photoperiod regulation strategies in farming. [ABSTRACT FROM AUTHOR]

Abstract: Sea cucumbers are regarded as traditional, delicious and luxurious seafood in Asia. Generally, it is difficult for species identification of sea cucumbers based on morphological characterization. In this study, Multiplex-PCR was developed to identify four sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, and Parastichopus californicus). After constructing the 692bp fragments of mitochondrial cytochrome oxidase I (COI) gene, four sets of species-specific primer were designed. The amplified lengths of fragments were 212bp for A. japonicus, 301bp for C. frondosa, 261bp for T. ananas and 358bp for P. californicus respectively, which could be obviously differentiated on DNA electrophoresis. The four sets of species-specific primer were mixed and applied to detect sea cucumber species simultaneously. Therefore, multiplex-PCR provided a convenient, useful, specific and academic technique to authenticate the sea cucumber species. This methodology can be very useful for traceability of sea cucumber species. [Copyright &y& Elsevier]

• P sorption capacity in soils increased with wetland restoration age. • Elevated P sorption related to the improvement of soil properties in restored wetland. • The P loss potential was less affected by the wetland restoration age. • The restored wetland was identified as the P storage hotspot at the landscape scale. Coastal wetlands, located at the intersection of land and sea, are considered to be a phosphorus (P) sink, source, and reactor in the global P cycle. However, the variation in P sorption capacity with wetland age and the related sorption mechanisms are not well understood. In this study, we collected the surface soil samples (0–20 cm) from 10 coastal freshwater wetlands that had been restored for 0–44 years surrounding China's Bohai Rim. Through a series of batch experiments, we studied the factors controlling P sorption and release in these soils. The results showed that the maximum P sorption capacity (Q max) in these wetlands was 294–2447 mg kg−1, with an average of 1472 mg kg−1. The Q max generally increased with increasing wetland restoration age. The degree of P saturation (DPS) and the P eutrophication risk index (ERI) for coastal wetlands were 0.5–9.5% and 0.9–21.1%, respectively. The DPS and ERI values did not vary significantly with wetland age. These data suggest that freshwater restoration significantly increases P sorption capacity, while not greatly affecting the P release potential in the coastal wetlands surrounding Bohai Rim. These observations may be related to the soil desalination and organic matter and amorphous Fe and/or Al accumulation that occur during the freshwater restoration of degraded wetlands. Coastal wetlands (especially restored wetlands) were suggested as P storage hotspots among upland, wetland, and offshore along the coastal watersheds of Bohai. These findings indicate that the freshwater restoration significantly improved the soil properties in the degraded coastal wetlands, and therefore increased P sorption capacity in the restored wetlands. [ABSTRACT FROM AUTHOR]

Nine units in new-born intertidal zone of the Yellow River estuary, China were examined for concentrations of heavy metals (Pb, Cr, Cu, Zn and Ni) in sediments and plants. Heavy metal levels in surface sediments were in the order of Zn > Pb ≈ Cr > Cu ≈ Ni and generally increased in a seaward direction except for Z6 ( Tamarix chinensis - Suaeda salsa zone) and Z7 ( S. salsa - T. chinensis zone) units. Significant differences in metal concentrations of the 9 units were observed in the profiles ( p < 0.01). Heavy metal levels in the shoots or roots of different plants decreased in the order of Zn > Cu > Pb > Ni > Cr and differed among plants or tissues. The roots at Z2 ( Calamagrostis pseudophragmites zone), Z3 ( Imperata cylindrical zone) and Z4 ( Phramites australis zone) units accumulated greater metals than shoots [TFs (translocation factors) < 1], while the shoots at Z1 ( Sparganium minimum - Potentilla supina zone), Z7 and Z8 ( S. salsa zone) units accumulated greater metals than roots (TFs > 1), implying that intertidal plants showed different pathways in metal accumulation and internal transportation. Except for Pb, the concentrations of Cr, Cu, Zn and Ni in sediments were lower than the criteria of Class I recommended by the Environmental Quality Standard for Soils of China. Although heavy metal levels in intertidal zone were generally the lowest (Cr, Cu, Zn and Ni) or relatively moderate (Pb) compared with other estuaries or bays in Asia and Europe, high eco-toxic risk of Pb and Ni exposure still could be observed at Z4, Z6 and Z9 (mudflat zone) units. S. salsa was more suitable for the potential biomonitor or phytoremediation of all five heavy metals if intertidal sediments was seriously contaminated with increasing of pollutants loading in the Yellow River estuary. [ABSTRACT FROM AUTHOR]