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Abstract Bacteria induced metamorphosis observed in nearly all marine invertebrates. However, the mechanism of bacteria regulating the larvae-juvenile metamorphosis remains unknown. Here, we test the hypothesis that c-di-GMP, a ubiquitous bacterial second-messenger molecule, directly triggers the mollusc Mytilus coruscus larval metamorphosis via the stimulator of interferon genes (STING) receptor. We determined that the deletion of c-di-GMP synthesis genes resulted in reduced c-di-GMP levels and biofilm-inducing activity on larval metamorphosis, accompanied by alterations in extracellular polymeric substances. Additionally, c-di-GMP extracted from tested varying marine bacteria all exhibited inducing activity on larval metamorphosis. Simultaneously, through pharmacological and molecular experiments, we demonstrated that M. coruscus STING (McSTING) participates in larval metamorphosis by binding with c-di-GMP. Our findings reveal that new role of bacterial c-di-GMP that triggers mussel larval metamorphosis transition, and extend knowledge in the interaction of bacteria and host development in marine ecosystems.

Abstract Biofilms serve as crucial cues for settlement and metamorphosis in marine invertebrates. Within bacterial systems, c-di-GMP functions as a pivotal signaling molecule regulating both biofilm formation and dispersion. However, the molecular mechanism of how c-di-GMP modulates biofilm-induced larval metamorphosis remains elusive. Our study reveals that the deletion of a c-di-GMP related gene in Pseudoalteromonas marina led to an increase in the level of bacterial c-di-GMP by knockout technique, and the mutant strain had an enhanced ability to produce more outer membrane vesicles (OMVs) and lipopolysaccharides (LPS). The mutant biofilms had higher induction activity for larval metamorphosis in mussels Mytilus coruscus, and OMVs play a major role in the induction activity. We further explored the function of LPS in OMVs. Extracted LPS induced high larval metamorphosis rate, and LPS content were subject to c-di-GMP and LPS-biosynthesis gene. Thus, we postulate that the impact of c-di-GMP on biofilm-induced metamorphosis is mediated through OMVs and LPS.

Marine invertebrates are the backbone of marine biodiversity and play a pivotal role in the marine ecosystem. The life cycle of most marine invertebrates includes the settlement and metamorphosis stage, which is induced by marine biofilms, but the mechanism is still enigmatic. In the present study, we constructed the capsular polysaccharide (CPS) synthesis gene capC-deleted mutant of Pseudoalteromonas marina by gene knockout and then compared the phenotype, the biofilm-forming ability, the effect on settlement and metamorphosis of Mytilus coruscus, and the exopolysaccharide and CPS levels between the mutant and the wild-type strains to explicate the relationship between bacteria and mussels. The study presented that the phenotype and biofilm-forming ability between the wild-type and ΔcapC strains had no significant difference, but the inducing activity of ΔcapC biofilms on larval settlement and metamorphosis decreased significantly (p < 0.05). Compared with the wild-type, the CPS content of ΔcapC strain significantly decreased by 38.07%, accompanied by the increase of c-di-GMP. Meanwhile, the biomass of α-polysaccharides and β-polysaccharides on ΔcapC biofilms decreased significantly (p < 0.05). Thus, the CPS synthesis gene could modulate c-di-GMP, which regulates bacterial polysaccharide secretion, and then impact larval settlement and metamorphosis of mussels. This work brings an entry point to deeply understand the interaction between bacterial polysaccharide and larval recruitment.

The aim of this study was to investigate the protective function and mechanism of TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) from skipjack tuna cardiac arterial bulbs on skin photoaging using UVB-irradiated HaCaT cell model. The present results indicated that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) had significant cytoprotective effect on UVB-irradiated HaCaT cells (p < 0.001). Hoechst 33342 staining showed that apoptosis of UV-irradiated HaCaT cells could be significantly reduced by the treatment of TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM); JC-1 staining showed that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could protect HaCaT cells from apoptosis by restoring mitochondrial membrane potential (MMP); Furthermore, TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could significantly down-regulate the ratio of Bax/Bcl-2 and reduce the expression level of the apoptosis-executing protein Caspase-3 by decreasing the expression of protein Caspase-8 and Caspase-9 (p < 0.05). The action mechanism indicated that TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) could up-regulate the expression levels of Nrf2, NQO1 and HO-1 (p < 0.05), which further increased the activity of downstream proteases (SOD, CAT and GSH-Px), and scavenged reactive oxygen species (ROS) and decreased the intracellular levels of malondialdehyde (MDA). In addition, molecular docking indicated that TCP3 (PKK) and TCP6 (YEGGD) could competitively inhibit the Nrf2 binding site because they can occupy the connection site of Nrf2 by binding to the Kelch domain of Keap1 protein. TCP9 (GPGLM) was inferred to be non-competitive inhibition because it could not bind to the active site of the Kelch domain of Keap1 protein. In summary, the antioxidant peptides TCP3 (PKK), TCP6 (YEGGD) and TCP9 (GPGLM) from cardiac arterial bulbs of skipjack tuna can effectively protect HaCaT cells from UVB-irradiated damage and can be used in the development of healthy and cosmetic products to treat diseases caused by UV radiation.

Cardiac arterial bulbs of Skipjack tuna (Katsuwonus pelamis) are rich in elastin, and its hydrolysates are high quality raw materials for daily cosmetics. In order to effectively utilizing Skipjack tuna processing byproducts-cardiac arterial bulbs and to prepare peptides with high antioxidant activity, pepsin was selected from six proteases for hydrolyzing proteins, and the best hydrolysis conditions of pepsin were optimized. Using ultrafiltration and chromatographic methods, eleven antioxidant peptides were purified from protein hydrolysate of tuna cardiac arterial bulbs. Four tripeptides (QGD, PKK, GPQ and GLN) were identified as well as seven pentapeptides (GEQSN, GEEGD, YEGGD, GEGER, GEGQR, GPGLM and GDRGD). Three out of them, namely the tripeptide PKK and the pentapeptides YEGGD and GPGLM exhibited the highest radical scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and superoxide anion assays. They also showed to protect plasmid DNA and HepG2 cells against H2O2-induced oxidative stress. Furthermore, they exhibited high stability under temperature ranged from 20-100 °C, pH values ranged from 3-11, and they simulated gastrointestinal digestion for 240 min. These results suggest that the prepared eleven antioxidant peptides from cardiac arterial bulbs, especially the three peptides PKK, YEGGD, and GPGLM, could serve as promising candidates in health-promoting products due to their high antioxidant activity and their stability.

In the work, defatted muscle proteins of monkfish (Lophius litulon) were separately hydrolyzed by pepsin, trypsin, and in vitro gastrointestinal (GI) digestion methods, and antioxidant peptides were isolated from proteins hydrolysate of monkfish muscle using ultrafiltration and chromatography processes. The antioxidant activities of isolated peptides were evaluated using radical scavenging and lipid peroxidation assays and H2O2-induced model of HepG2 cells. In which, the cell viability, reactive oxygen species (ROS) content, and antioxidant enzymes and malondialdehyde (MDA) levels were measured for evaluating the protective extent on HepG2 cells damaged by H2O2. The results indicated that the hydrolysate (MPTH) prepared using in vitro GI digestion method showed the highest degree of hydrolysis (27.24 ± 1.57%) and scavenging activity on a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (44.54 ± 3.12%) and hydroxyl radical (41.32 ± 2.73%) at the concentration of 5 mg protein/mL among the three hydrolysates. Subsequently, thirteen antioxidant peptides (MMP-1 to MMP-13) were isolated from MPTH. According to their DPPH radical and hydroxyl radical scavenging activity, three peptides with the highest antioxidant activity were selected and identified as EDIVCW (MMP-4), MEPVW (MMP-7), and YWDAW (MMP-12) with molecular weights of 763.82, 660.75, and 739.75 Da, respectively. EDIVCW, MEPVW, and YWDAW showed high scavenging activities on DPPH radical (EC50 0.39, 0.62, and 0.51 mg/mL, respectively), hydroxyl radical (EC50 0.61, 0.38, and 0.32 mg/mL, respectively), and superoxide anion radical (EC50 0.76, 0.94, 0.48 mg/mL, respectively). EDIVCW and YWDAW showed equivalent inhibiting ability on lipid peroxidation with glutathione in the linoleic acid model system. Moreover, EDIVCW, MEPVW, and YWDAW had no cytotoxicity to HepG2 cells at the concentration of 100.0 µM and could concentration-dependently protect HepG2 cells from H2O2-induced oxidative damage through decreasing the levels of reactive oxygen species (ROS) and MDA and activating intracellular antioxidant enzymes of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). These present results indicated that the protein hydrolysate and isolated antioxidant peptides from monkfish muscle, especially YWDAW could serve as powerful antioxidants applied in the treatment of some liver diseases and healthcare products associated with oxidative stress.

Many studies have explored the social consequences of ethnic essentialism in recent decades. In addition, a few studies have focused on the impact of perceived cultural context on ethnic essentialism. However, it is not clear why perceived cultural context can lead to changes in ethnic essentialism. In the present study, we hypothesized that the cultural anxiety of ethnic minorities may trigger a strong endorsement of and support for a multicultural ideology, thereby affecting beliefs about ethnic groups. To address the issue, 226 Tibetan and 102 Hui college students from Mainland China completed our questionnaires. The results across the two samples showed that (1) cultural anxiety was positively associated with both the endorsement of a multicultural ideology and ethnic essentialism, (2) cultural anxiety and the endorsement of a multicultural ideology positively predicted ethnic essentialism after controlling for demographic variables, and (3) cultural anxiety had both a direct effect on ethnic essentialism and an indirect effect on ethnic essentialism through the endorsement of a multicultural ideology. Our findings suggest that when ethnic minorities experience cultural anxiety, they might endorse a multicultural ideology and adopt essentialism to affirm their ethnic identities.

Reliable monitoring and thorough spatiotemporal prediction of meteorological drought are crucial for early warning and decision-making regarding drought-related disasters. The utilisation of multiscale methods is effective for a comprehensive evaluation of drought occurrence and progression, given the complex nature of meteorological drought. Nevertheless, the nonlinear spatiotemporal features of meteorological droughts, influenced by various climatological, physical and environmental factors, pose significant challenges to integrated prediction that considers multiple indicators and time scales. To address these constraints, we introduce an innovative deep learning framework based on the shifted window transformer, designed for executing spatiotemporal prediction of meteorological drought across multiple scales. We formulate four prediction indicators using the standardized precipitation index and the standard precipitation evaporation index as core methods for drought definition using the ERA5 reanalysis dataset. These indicators span time scales of approximately 30 d and one season. Short-term indicators capture more anomalous variations, whereas long-term indicators attain comparatively higher accuracy in predicting future trends. We focus on the East Asian region, notable for its diverse climate conditions and intricate terrains, to validate the model's efficacy in addressing the complexities of nonlinear spatiotemporal prediction. The model's performance is evaluated from diverse spatiotemporal viewpoints, and practical application values are analysed by representative drought events. Experimental results substantiate the effectiveness of our proposed model in providing accurate multiscale predictions and capturing the spatiotemporal evolution characteristics of drought. Each of the four drought indicators accurately delineates specific facets of the meteorological drought trend. Moreover, three representative drought events, namely flash drought, sustained drought and severe drought, underscore the significance of selecting appropriate prediction indicators to effectively denote different types of drought events. This study provides methodological and technological support for using a deep learning approach in meteorological drought prediction. Such findings also demonstrate prediction issues related to natural hazards in regions with scarce observational data, complex topography and diverse microclimate systems.

Quantification of currently attainable yield and fertilizer requirements can provide detailed information for assessing the food supply capacity and offer data support for agricultural decision-making. Datasets from a total of 5 408 field experiments were collected from 2000 to 2015 across the major wheat production regions in China to analyze the spatial distribution of wheat yield, the soil nutrient supply capacity (represented by relative yield, defined as the ratio of the yield under the omission of one of nitrogen (N), phosphorus (P) and potassium (K) to the yield under the full NPK fertilizer application), and N, P and K fertilizer requirements by combining the kriging interpolation method with the Nutrient Expert Decision Support System for Wheat. The results indicated that the average attainable yield was 6.4 t ha–1, with a coefficient of variation (CV) of 24.9% across all sites. The yields in North-central China (NCC) and the northern part of the Middle and Lower reaches of the Yangtze River (MLYR) were generally higher than 7 t ha–1, whereas the yields in Southwest China (SWC), Northeast China (NEC), and the eastern part of Northwest China (NWC) were usually less than 6 t ha–1. The precentage of area having a relative yield above 0.70, 0.85, and 0.85 for N, P, and K fertilizers accounted for 52.3, 74.7, and 95.9%, respectively. Variation existed in N, P, and K fertilizer requirements, with a CV of 24.8, 23.9, and 29.9%, respectively, across all sites. More fertilizer was needed in NCC and the northern part of the MLYR than in other regions. The average fertilizer requirement was 162, 72, and 57 kg ha–1 for N, P2O5, and K2O fertilizers, respectively, across all sites. The incorporation of the spatial variation of attainable yield and fertilizer requirements into wheat production practices would benefit sustainable wheat production and environmental safety.

Previous studies have reported that inhibitor of DNA binding 1 (ID1) exerts an oncogenic role in a number of tumors. In the present study, the role of ID1 in the growth, invasion and migration of salivary adenoid cystic carcinoma (SACC) cells was investigated. ID1 expression in clinical SACC samples was compared with that in normal salivary tissues using immunohistochemical staining, and the correlation between ID1 expression and clinical pathological characteristics was then determined. Subsequently, ID1 was overexpressed or silenced to investigate the effects of ID1 expression on SACC cell proliferation, invasion and migration. In addition, the gene expression levels of known ID1 target genes, including S100A9, CDKN2A and matrix metalloproteinase 1 (MMP1) was measured using reverse transcription-quantitative polymerase chain reaction to elucidate the potential mechanisms of ID1 in SACC. The results of the present study indicated that the protein expression levels of ID1 were significantly increased in the SACC tissues compared with that in the normal salivary tissues (P<0.001), and a positive correlation between ID1 expression and tumor stage (P=0.001), tumor invasion (P=0.002) and metastasis (P=0.019) in SACC was observed. Knockdown of ID1 in SACC cells significantly inhibited cell growth, invasion and migration (all P<0.01), whereas overexpression of ID1 promoted cell proliferation, invasion and migration (all P<0.01). The gene expression level of MMP1 was significantly reduced following ID1 knockdown in SACC-83 cells when compared with negative controls (P<0.05), whereas S100A9 and CDKN2A expression levels were significantly upregulated (both P<0.05). The results suggest that ID1 may regulate the growth, invasion and migration of SACC cells, and that MMP1, S100A9 and CDKN2A may serve as target genes of ID1 and mediate the effects of ID1 in SACC cells. Therefore, ID1 may present a potential target gene for the treatment of patients with SACC to inhibit cancer cell growth and metastasis. [ABSTRACT FROM AUTHOR]

Shanghai is physically and socio-economically vulnerable to accelerated sea level rise because of its low elevation, flat topography, highly developed economy and highly-dense population. In this paper, two scenarios of sea level rise and storm surge flooding along the Shanghai coast are presented by forecasting 24 (year 2030) and 44 (year 2050) years into the future and are applied to a digital elevation model to illustrate the extent to which coastal areas are susceptible to levee breach and overtopping using previously developed inflow calculating and flood routing models. Further, the socio-economic impacts are examined by combining the inundation areas with land use and land cover change simulated using GeoCA-Urban software package. This analysis shows that levee breach inundation mainly occurs in the coastal zones and minimally intrudes inland with the conservative protection of dike systems designed. However, storm surge flooding at the possible maximum tide level could cause nearly total inundation of the landscape, and put approximately 24 million people in Shanghai under direct risk resulting from consequences of flooding (e.g. contamination of potable water supplies, failure of septic systems, etc.). [ABSTRACT FROM AUTHOR]

We address the occurrence of the warm anomaly, known as the Blob, that developed from late 2013 to 2015 in the northeast Pacific and its connection with the El Niño–Southern Oscillation (ENSO) variability. The warm Blob results from the enhanced second ocean–atmosphere (O–A) coupled mode of variability in the tropical and North Pacific, representing a small part of the Victoria mode (VM) in the northeast Pacific forced by the strengthened North Pacific Oscillation-like atmospheric pattern since 2013. We also show that this second O–A mode reflects the meridional variability through the tropical–extratropical teleconnection and is an important precursor to the ENSO variability. The process is confirmed by the coupled patterns that evolved from late 2013 to 2016 and the multi-year persistence of the warm Blob. We emphasize the role of evolving basin-scale VM but not the warm Blob itself prior to the ENSO variability. Hence, the Blob and the most recent 2015/16 El Niño, which differs significantly from the other large El Niños in terms of the triggering hemisphere, are actually linked rather than independent phenomena.