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Identifying and quantifying water nitrate pollution is crucial for managing aquatic environment of a bay. Dongshan Bay, a significant semi-enclosed bay in the southeastern coastal area of Fujian Province, features mangrove and coral reef ecosystems at its estuary and bay mouth, respectively. Dongshan Bay is impacted by human activities such as mariculture. We quantified and analyzed nitrate pollution status in the surface waters of Dongshan Bay by measuring physicochemical parameters, stable isotopes (δ15N-NO3-, δ18O-NO3- and δ15N-NH4+) of the surface waters, and using statistical methods including the MixSIAR isotope mixing model. The results showed that the concentrations of chlorophyll a and dissolved inorganic nitrogen in the surface waters exhibited a noticeable gradient change, decreasing from the estuary of the Zhangjiang River to the mouth of Dongshan Bay. The maximum concentrations of chlorophyll a, NH4+, NO3- and NO2- were 45.2 µg • L-1, 52.67 µmol • L-1, 379.2 µmol • L-1 and 3.93 µmol • L-1, respectively. The nitrogen and oxygen isotope values of NH4+ and NO3 in the surface waters showed significant spatial variations. According to the MixSIAR model results, nitrogen sources in the surface waters of Dongshan Bay were mainly freshwater inputs of the Zhangjiang River estuary, aquaculture wastewater, and groundwater. The freshwater input from the Zhangjiang River estuary contributed the most (25.2%), while aquaculture wastewater, groundwater and urban sewage accounted for 24.6%, 19.0%, and 15.1%, respectively. It is evident that freshwater input from the Zhangjiang River estuary is the primary source of nitrate in the surface waters of Dongshan Bay. [ABSTRACT FROM AUTHOR]

In this study, we investigated the feasibility of using electroencephalogram (EEG) signals to differentiate between four distinct subject-driven cognitive states: resting state, narrative memory, music, and subtraction tasks. EEG data were collected from seven healthy male participants while performing these cognitive tasks, and the raw EEG signals were transformed into time–frequency maps using continuous wavelet transform. Based on these time–frequency maps, we developed a convolutional neural network model (TF-CNN-CFA) with a channel and frequency attention mechanism to automatically distinguish between these cognitive states. The experimental results demonstrated that the model achieved an average classification accuracy of 76.14% in identifying these four cognitive states, significantly outperforming traditional EEG signal processing methods and other classical image classification algorithms. Furthermore, we investigated the impact of varying lengths of EEG signals on classification performance and found that TF-CNN-CFA demonstrates consistent performance across different window lengths, indicating its strong generalization capability. This study validates the ability of EEG to differentiate higher cognitive states, which could potentially offer a novel BCI paradigm. [ABSTRACT FROM AUTHOR]

In this study, the complete mitogenome sequence of the stony coral, Turbinaria bifrons Brüggemann, 1877, has been decoded for the first time by next-generation sequencing (NGS) and genome assembly. The assembled mitogenome was 18,880 bp in length, contained 13 protein coding genes, 2 transfer RNAs, and 2 ribosomal RNAs. The complete mitogenome of T. bifrons showing 97.09% identities to Tubastraea tagusensis. The complete mitogenome provides essential and important DNA molecular data for further phylogenetic and evolutionary analysis for coral phylogeny. [ABSTRACT FROM AUTHOR]

The particular environmental characteristics of deep water such as its immense scale and high pressure systems, presents technological problems that have prevented research to broaden our knowledge of deep-sea fish. Here, we described the mitogenome sequence of a deep-sea fish, Cetonurus globiceps. The genome is 17,137 bp in length, with a standard set of 22 transfer RNA genes (tRNAs), two ribosomal RNA genes, 13 protein-coding genes, and two typical non-coding control regions. Additionally, a 70bp tRNAThr-tRNAPro intergenic spacer is present. The C. globiceps mitogenome exhibited strand-specific asymmetry in nucleotide composition. The AT-skew and GC-skew values in the whole genome of C. globiceps were 0 and -0.2877, respectively, revealing that the H-strand had equal amounts of A and T and that the overall nucleotide composition was C skewed. All of the tRNA genes could be folded into cloverleaf secondary structures, while the secondary structure of tRNASer(AGY) lacked a discernible dihydrouridine stem. By comparing this genome sequence with the recognition sites in teleost species, several conserved sequence blocks were identified in the control region. However, the GTGGG-box, the typical characteristic of conserved sequence block E (CSB-E), was absent. Notably, tandem repeats were identified in the 3' portion of the control region. No similar repetitive motifs are present in most of other gadiform species. Phylogenetic analysis based on 12 protein coding genes provided strong support that C. globiceps was the most derived in the clade. Some relationships however, are in contrast with those presented in previous studies. This study enriches our knowledge of mitogenomes of the genus Cetonurus and provides valuable information on the evolution of Macrouridae mtDNA and deep-sea fish. [ABSTRACT FROM AUTHOR]

Meiofauna are important components of marine benthic communities. However, knowledge of meiofauna in Antarctica is limited, especially in East Antarctica. Samples of meiofauna from sixteen stations were collected in Prydz Bay and its neighboring area from February to March 2013, and could be divided into three regions by depth: Bay area (BA), continental Shelf area (SA), and Deep-sea area (DA). Up to twelve taxa were identified. Nematodes were the dominant taxon, accounting for 97% of the abundance. The average abundance of meiofauna were 1181 ± 1137 ind·10 cm−2 and decreased with increasing distance from coast, as did the number of meiofauna taxa. More than a half of meiofauna individuals occupied the upper 2 cm of sediments. Many individuals (41.5%) were 65–125 μm, but there were differences among the four dominant taxa. Cluster analysis at the taxon level showed that the sixteen stations could be separated into three clusters, which were nearly strongly associated with geographic location. Large differences in abundance were found in the three regions, and environmental factors such as food availability, grain size of surface sediments, and depth greatly shaped the distribution. It was unusual that abundance of meiofauna was significantly and positively correlated with depth in Prydz Bay, which was likely resulted from food supply, topography and circulation, as well as relatively suitable sediment size and reduced disturbance from icebergs. • First report on the abundance of meiofauna in Prydz Bay. • Environmental conditions prompt meiofauna community to flourish in deep waters than in shallow shelf in summer. • Food supply is the main factor in sharping meiofauna community in summer Prydz Bay. [ABSTRACT FROM AUTHOR]

Lack of mitochondrial genome data of Scleractinia is hampering progress across genetic, systematic, phylogenetic and evolutionary studies. In this study, the complete mitogenome sequence of the stony coral, Acropora valida (Dana, 1846), has been decoded for the first time by next-generation sequencing and genome assembly. The assembled mitogenome was 18,385 bp in length, containing 13 protein-coding genes (PCGs), two transfer RNAs and two ribosomal RNAs. All genes were encoded on the same strand. The A + T content of the mitochondrial genome was 62.0% (25.0% A, 37.0% T, 24.3% G, and 13.8% for C). The complete mitogenome of Acropora valida has the same gene content and structure as other Acropora species. The complete mitogenome provides essential and important DNA molecular data for further phylogenetic and evolutionary analyses for coral phylogeny. [ABSTRACT FROM AUTHOR]

In this study, the complete mitogenome sequence of Pentacheles validus has been decoded for the first time. The overall base composition is 33.4% for A, 25.0% for C, 10.8% for G, and 30.9% for T and has low GC content of 35.8%. The assembled mitogenome, 16,079 bp in length, has unique 13 protein-coding genes (PCGs), 22 transfer RNAs and 2 ribosomal RNAs. The mitogenome shares 80% identity to Polycheles typhlops. The complete mitogenome of P. validus provides essential DNA molecular data for further phylogenetic and evolutionary analysis for Polychelidae and deep-sea faunas. [ABSTRACT FROM AUTHOR]

As a key environmental parameter to induce radiation dose and effect on non-human species, radioactivity level is rarely evaluated in typical ecosystems of coral reefs, mangroves, and hydrothermal vents. In this study, naturally occurring radionuclides (238U, 226Ra, 228Ra, and 40K) in carbonate, silicate, and sulfide sediments collected from coral reefs, mangroves, and hydrothermal vents were simultaneously measured using high purity germanium (HPGe) γ spectrometry. Radioactivity levels and radionuclide fingerprints (226Ra/238U and 228Ra/226Ra) were interpreted and explored for tracking sources and formation processes of marine sediments in distinct marine ecosystems. Additionally, ionizing radiation dose rate on representative marine biotas (mollusc-bivalve, crustacean, polychaete worm, benthic fish, and pelagic fish) was evaluated using the ERICA tool with an increasing rank in coral reefs < mangroves < hydrothermal vents. Polychaete worm received the highest radiation dose relative to other marine biotas. We also emphasized the dominant contribution of 210Po to total radiation dose rate on marine biotas. Unlabelled Image • Radioactivity levels were studied in coral reefs, mangroves, and hydrothermal vents. • Radionuclide fingerprints were closely related to chemical components in sediments. • Radiation dose rate on marine biotas was evaluated using the ERICA tool. • The dominant role of 210Po in radiation dose rate on marine biotas was emphasized. [ABSTRACT FROM AUTHOR]