The aim of this study was to provide technical means and data support for enhancing the filtration pretreatment capacity of a recirculating aquaculture system. A continuous flow electrocoagulation ...(EC)-filtration system was designed and its application in the pretreatment of marine aquaculture wastewater was studied. The influences of anode combination modes, hydraulic retention times (HRTs) of the EC reactor and filter pore sizes on the water treatment capacity were investigated. Results showed that EC could significantly enhance the treatment efficiency of the filtration equipment used in subsequent steps. Al-Fe electrodes used as anode led to better processing capacity of this system, and the optimum anode was 3Al + Fe. With the increase of HRT and decrease of filter pore size, the enhanced effect of the EC process on the filter was more obvious. When the current density was 19.22 A/m
, the anode was 3Al + Fe, the HRT was 4.5 min and the filter pore size was 45 μm, the removal efficiency of the system for Vibrio, chemical oxygen demand, total ammonia nitrogen, nitrite nitrogen (NO
-N), nitrate nitrogen (NO
-N) and total nitrogen was 69.55 ± 0.93%, 48.99 ± 1.42%, 57.06 ± 1.28%, 34.09 ± 2.27%, 18.47 ± 1.88% and 55.26 ± 1.42%, respectively, and the energy consumption was (26.25 ± 4.95) × 10
kWh/m
.
Despite the mitochondrial antiviral signalling protein (MAVS)-dependent RIG-I-like receptor (RLR) signalling pathway in the cytosol plays an indispensable role in the antiviral immunity of the host, ...surprising little is known in invertebrates. Here we characterized the major members of RLR pathway and investigated their signal transduction a Molluscs. We show that genes involved in RLR pathway were significantly induced during virus challenge, including CgRIG-I-1, CgMAVS, CgTRAF6 (TNF receptor-associated factor 6), and CgIRFs (interferon regulatory factors. Similar to human RIG-I, oyster RIG-I-1 could bind poly(I:C) directly in vitro and interact with oyster MAVS via its caspase activation and recruitment domains. We also show that transmembrane domain-dependent self-association of CgMAVS may be crucial for its signalling and that CgMAVS can recruit the downstream signalling molecule, TRAF6, which can subsequently activate NF-κB signal pathway. Moreover, oyster IRFs appeared to function downstream of CgMAVS and were able to activate the interferon β promoter and interferon stimulated response elements in mammalian cells. These results establish invertebrate MAVS-dependent RLR signalling for the first time and would be helpful for deciphering the antiviral mechanisms of invertebrates and understanding the development of the vertebrate RLR network.
•The influence of electron–phonon interaction on the conductivity of metal-based epitaxial graphene is studied.•The temperature-dependent variation pattern of conductivity induced by vacancy defect ...concentration is revealed.•The influence of anharmonic effects on the conductivity and its variation pattern are revealed.
Metal-based epitaxial graphene exhibits extremely high conductivity at room temperature, making the study of its conductance crucial for understanding electron transport mechanisms in two-dimensional materials. In this paper, we applied solid-state physics theories and methods to investigate factors influencing the conductivity of metal-based epitaxial graphene. We considered the variation of conductivity and its temperature stability coefficient with temperature, taking into account the anharmonic vibrations of atoms, and explored the impact of anharmonic effects on conductivity. Using copper-based graphene as an example, we established relationships between temperature and several key parameters: electronic conductivity (σe), conductivity contributed by electron–phonon interactions (σp), conductivity contributed by vacancy defects (σn), and total conductivity (σ), along with its temperature stability coefficient (ασ). All research results were obtained within the temperature range of 300 K to 1200 K. The study reveals that σ decreases nonlinearly as temperature increases, with a magnitude on the order of (Ω ∙ m)-1, which is approximately equal to σp. The conductivity of copper-based epitaxial graphene is found to be greater than that of lithium-based epitaxial graphene. The anharmonic effects of atomic vibrations increase σ, and this increase is more pronounced at higher temperatures. The temperature stability coefficient ασ rapidly decreases with increasing temperature before tending to a constant, indicating that conductivity exhibits better temperature stability at higher temperatures. This paper provides theoretical guidance for understanding electron transport characteristics of metal-based epitaxial graphene and contributes to the design and application of high-performance electronic devices.
Aeromonas salmonicida (A. salmonicida) is a pathogenic bacterium that causes furunculosis and poses a significant global risk, particularly in economic activities such as Atlantic salmon (Salmo ...salar) farming. In a previous study, we identified proteins that are significantly upregulated in kidneys of Atlantic salmon challenged with A. salmonicida. Phosphoproteomic analyses were conducted to further clarify the dynamic changes in protein phosphorylation patterns triggered by bacterial infection. To our knowledge, this is the first study to characterize phosphorylation events in proteins from A. salmonicida-infected Atlantic salmon. Overall, we identified over 5635 phosphorylation sites in 3112 proteins, and 1502 up-regulated and 77 down-regulated proteins quantified as a 1.5-fold or greater change relative to control levels. Based on the combined data from proteomic and motif analyses, we hypothesize that five prospective novel kinases (VRK3, GAK, HCK, PKCδ and RSK6) with common functions in inflammatory processes and cellular pathways to regulate apoptosis and the cytoskeleton could serve as potential biomarkers against bacterial propagation in fish. Data from STRING-based functional network analyses indicate that fga is the most central protein. Our collective findings provide new insights into protein phosphorylation patterns, which may serve as effective indicators of A. salmonicida infection in Atlantic salmon.
Hatchery-reared larvae of the Pacific oyster (Crassostrea gigas) often suffer from massive mortality induced by Ostreid herpesvirus 1 (OsHV-1) infection, indicating the importance of better ...understanding of oyster immune defense systems. The accuracy of measurements of gene expression levels based on quantitative real-time PCR assays relies on the use of housekeeping genes as internal controls; however, few studies have focused on the selection of such internal controls. In this study, we conducted a comprehensive investigation of internal control genes during oyster development in virus-infected and uninfected samples. Transcriptome data for 38 developmental stages were downloaded and the gene expression patterns were classified into 30 clusters. A total of 317 orthologs of classical housekeeping genes in the oyster genome were annotated. After combining the expression profiles and oyster housekeeping gene dataset, 14 candidate internal controls were selected for further investigation: Elongation factor-1α (EF-1α), 18S rRNA (18S), 28S rRNA (28S), Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-actin (ACT), Ribosomal protein L7 (RL7), Ribosomal protein L27 (RL27), Ribosomal protein L36 (RL36), Ribosomal protein S18 (RS18), Heterogeneous nuclear ribonucleoprotein A2/B1 (RO21), Eukaryotic translation elongation factor 2 (EF2), Ubiquitin-conjugating enzyme E2D2 (UBCD1), S-phase kinase-associated protein 1 (SKP1) and Heterogeneous nuclear ribonucleoprotein Q (HNRPQ). RNA was extracted from oyster larvae infected with OsHV-1 (group A; GA), and OsHV-1 free larvae (group B; GB). The expression levels of the 14 candidate internal controls were studied in GA and GB larvae by real-time PCR. Their expression stabilities were further analyzed using the GeNorm program. RL7 and RS18 were the most stable genes in both OsHV-1 infected (GA) and uninfected (GB) larvae. These results suggest that RL7 and RS18 could be used as internal controls for studying gene expression in normal growing oyster larvae and in OsHV-1 infected larvae. These high quality internal controls will be a valuable resource in future studies of oyster larval mortality.
► Describing the evaluation of C. gigas housekeeping genes in developmental stages. ► RL7 and RS18 are the most suitable internal controls for qRT-PCR in C. gigas larvae. ► EF-1α, 18S, 28S, GAPDH and ACT are not suitable internal controls in C. gigas larvae.
The Pacific oyster Crassostrea gigas belongs to one of the most species-rich but genomically poorly explored phyla, the Mollusca. Here we report the sequencing and assembly of the oyster genome using ...short reads and a fosmid-pooling strategy, along with transcriptomes of development and stress response and the proteome of the shell. The oyster genome is highly polymorphic and rich in repetitive sequences, with some transposable elements still actively shaping variation. Transcriptome studies reveal an extensive set of genes responding to environmental stress. The expansion of genes coding for heat shock protein 70 and inhibitors of apoptosis is probably central to the oyster's adaptation to sessile life in the highly stressful intertidal zone. Our analyses also show that shell formation in molluscs is more complex than currently understood and involves extensive participation of cells and their exosomes. The oyster genome sequence fills a void in our understanding of the Lophotrochozoa.
Caspase-3 and caspase-7 are two key effector caspases that play important roles in apoptotic pathways that maintain normal tissue and organ development and homeostasis. However, little is known about ...the sequence, structure, activity, and function of effector caspases upon apoptosis in mollusks, especially marine bivalves. In this study, we investigated the possible roles of two executioner caspases in the regulation of apoptosis in the Pacific oyster Crassostrea gigas. A full-length caspase-3-like gene named Cgcaspase-3 was cloned from C.gigas cDNA, encoding a predicted protein containing caspase family p20 and p10 domain profiles and a conserved caspase active site motif. Phylogenetic analysis demonstrated that both Cgcaspase-3 and Cgcaspase-1 may function as effector caspases clustered in the invertebrate branch. Although the sequence identities between the two caspases was low, both enzymes possessed executioner caspase activity and were capable of inducing cell death. These results suggested that Cgcaspase-3 and Cgcaspase-1 were two effector caspases in C. gigas. We also observed that nucleus-localized Cgcaspase-3, may function as a caspase-3-like protein and cytoplasm-localized Cgcaspase-1 may function as a caspase-7-like protein. Both Cgcaspase-3 and Cgcaspase-1 mRNA expression increased after larvae settled on the substratum, suggesting that both caspases acted in several tissues or organs that degenerated after oyster larvae settlement. The highest caspase expression levels were observed in the gills indicating that both effector caspases were likely involved in immune or metabolic processes in C. gigas.
Electrocoagulation (EC) is an environmentally friendly and effective water treatment technique. It has been recently applied in combination with a filtration process. This study investigated the ...effects of an alternating pulse current (APC) on the electrodes, treatment efficiency, and energy consumption of an EC−filtration system during the treatment of mariculture tailwaters, from the aspects of current density and current conversion period (CCP), to generate ideas for improving the performance of the system. Results showed that using direct current (DC) would aggravate the electrode passivation, resulting in many white insoluble substances covering the surface of the electrodes. Moreover, the electrode passivation was more intense at a higher current density and longer system operation time (SOT). Significantly, the electrode weight increased by 1546.67 ± 54.50 mg when the system was operated for 90 min under DC at a current density of 45 A/m2. Unlike DC, APC significantly alleviated electrode passivation, enhanced the treatment efficiency, and reduced energy consumption. A shorter CCP produced better results. When the CCP was 1 min, current density was 45 A/m2, and SOT was 10 min, the removal efficiency of the EC−filtration system for total suspended solids (TSS), chemical oxygen demand (CODMn), and total nitrogen (TN) was 53.55 ± 1.66%, 47.76 ± 0.18%, and 15.55 ± 0.31%, respectively, and the energy consumption was 11.88 × 10−3 kWh/m3.
Mollusk shell is one kind of potential biomaterial, but its vague mineralization mechanism hinders its further application. Mollusk shell matrix proteins are important functional components that are ...embedded in the shell, which play important roles in shell formation. The proteome of the oyster shell had been determined based on the oyster genome sequence by our group and gives the chance for further deep study in this area. The classical model of shell formation posits that the shell proteins are mantle-secreted. But, in this study, we further analyzed the shell proteome data in combination with organ transcriptome data and we found that the shell proteins may be produced by multiple organs though the mantle is still the most important organ for shell formation. To identify the transport pathways of these shell proteins not in classical model of shell formation, we conducted a shell damage experiment and we determined the shell-related gene set to identify the possible transport pathways from multiple organs to the shell formation front. We also found that there may exist a remodeling mechanism in the process of shell formation. Based on these results along with some published results, we proposed a new immature model, which will help us think about the mechanism of shell formation in a different way.
Designing good recirculating aquaculture systems (RASs) is challenging in shrimp aquaculture. In this study, two sets of RASs were constructed using sea cucumber nursery tanks for rearing Litopenaeus ...vannamei. Recirculating aquaculture was supported by key technologies such as sewage collection and aeration systems adapted to the rectangular tanks and technologies for the removal of sewage, shrimp shells, and dead individuals. Six-hundred and eighty-five thousand juveniles were selected for rearing in the newly constructed RASs, where the average stocking density was 1013 shrimp/m3. During the recirculating aquaculture period of 53 days, the water temperature of the tanks was 24–31 °C, the salinity was 25–32‰, the pH was 6.4–8.2, the DO was ≥ 4.9 mg/L, the concentration of total ammonia nitrogen (TAN) was maintained between 0.17 and 4.9 mg/L, the concentration of nitrite nitrogen (NO2-N) was between 0.12 and 4.7 mg/L, and the total number of Vibrio bacteria remained between 330 and 9700 cfu/mL. At the end of the experiment, the final average weight of individual shrimp was 13.43 g, and the average yield reached 12.92 kg/m3. The great improvement in growth performance marks a breakthrough in RAS technology of shrimp, and it supports the use of an innovative methodology for the retrofitting and utilization of idle sea cucumber nursery tanks.
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