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With the swift progression of three-dimensional (3D) modeling and multimedia technology, the unauthorized duplication and manipulation of 3D point cloud data has become more prevalent. Existing watermarking algorithms designed for 3D point cloud data lack robustness against rotation, cropping, and random point addition attacks. To address the aforementioned issues, we propose a robust watermarking algorithm based on the Mahalanobis distance (MD) and feature point extraction, including zero-watermarking algorithm based on MD and watermarking algorithm based on the Intrinsic Shape signatures (ISS) feature points. Firstly, calculate the MD of point cloud data and use it to construct feature matrix. A zero-watermark image is constructed through the XOR operation of the feature matrix and the copyright information matrix. Secondly, ISS feature points can be extracted from point cloud data, which using the X and Y coordinates of the feature points as indexes. The color information of the feature points is used as host data to embed the watermark. The scale invariance of MD and the stability of ISS feature points augment the robustness of the algorithm. Experimental results demonstrate that the scheme we propose exhibits strong robustness against geometric attacks, simplification attacks, cropping attacks, reordering, and noise attacks while ensuring point cloud data coordinates are lossless. [ABSTRACT FROM AUTHOR]

Copepoda are one of the most significant animal groups present in aquatic ecosystems. Ecologists, evolutionary biologists, and biotechnologists continue to test new methods to study the application of Copepoda as model organisms in various fields of pure and applied science, from evolution and ecology to aquaculture as live feed, as biological control of mosquito larvae, as biological indicators of water and sediment quality, in environmental monitoring and as a source of protein in the food industry. This paper reviews the current progress and trends within copepod research from a number of different perspectives. We emphasize the importance of Copepoda and the necessity of strengthening research on various topics related to copepod biology, some of which are of great significance to local sustainable development. [ABSTRACT FROM AUTHOR]

Nickel acts as an essential trace nutrient or toxicant for organisms, depending on its concentration. The increased concentrations of nickel, due to anthropogenic activity, in the aquatic environment are potential threats to aquatic organisms. However, the knowledge on toxic mechanisms of nickel to microalgae remains incompletely understood. In the present study, we investigated the toxic effects of nickel in the cosmopolitan diatom Phaeodactylum tricornutum via evaluation of physiological and transcriptome responses. The results showed that the median effective concentration-72 h (EC50-72 h) and EC50-96 h of nickel was 2.48 ± 0.33 and 1.85 ± 0.17 mg/L, respectively. The P. tricornutum cell abundance and photosynthesis significantly decreased by 1 mg/L of nickel. Results from photosynthetic parameters including efficiency of the oxygen evolving complex (OEC) of photosystem II (PSII) (Fv/F0), maximum photosynthetic efficiency of PS II (Fv/Fm), electron transport rate (ETR), actual photosynthetic efficiency of PS II (Y(II)), non-photochemical quenching (NPQ), and photochemical quenching (qP) indicated that OEC of PS II might be impaired by nickel. The transcriptome data also reveal that OEC apparatus coding gene PS II oxygen-evolving enhancer protein 2 (PsbP) was regulated by nickel. Moreover, induced reactive oxygen species (ROS) production and chlorophyll a content were also detected under nickel stress. Transcriptome analysis revealed that nickel affected a variety of differentially expressed genes (DEGs) that involved in redox homeostasis, nitrogen metabolisms, fatty acids, and DNA metabolism. However, thiol-disulfide redox system might play important roles in nickel-induced oxidative stress resistance. This study improved the understanding of the toxic effect of nickel on the diatom P. tricornutum. [ABSTRACT FROM AUTHOR]

CaBi8−xEuxTi7O27 (CBT-BIT-xEu3+, x = 0.00, 0.05, 0.10, 0.15, and 0.20) intergrowth-structured ceramics were synthesized using a solid-state reaction method. The intergrowth structures were successfully obtained and clearly observed by HR-TEM along the [1¯10] zone axis. Raman patterns indicated that Eu3+ preferred to occupy the A sites in pseudo-perovskite layers and increased the orthorhombicity and structural distortion degree of TiO6 octahedra, which was further supported by refined structural parameters produced by GSAS software. As a consequence of increased orthorhombicity, the Curie temperature was increased from 736 °C for pure CBT-BIT to 758 °C for CBT-BIT-0.1Eu3+ ceramic. Simultaneously, CBT-BIT-0.1Eu3+ achieved the strongest red-orange emission and the CIE chromaticity coordinates calculated to be (0.627, 0.372), which suggested the potential applications of this material in high-temperature electrooptic applications. [ABSTRACT FROM AUTHOR]