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Background Recently, increasing evidence supports that some complex diseases are not attributed to a given pathogen, but dysbiosis in the host intestinal microbiota (IM). The full intestinal ecosystem alterations, rather than a single pathogen, are associated with white feces syndrome (WFS), a globally severe non-infectious shrimp disease, while no experimental evidence to explore the causality. Herein, we conducted comprehensive metagenomic and metabolomic analysis, and intestinal microbiota transplantation (IMT) to investigate the causal relationship between IM dysbiosis and WFS. Results Compared to the Control shrimp, we found dramatically decreased microbial richness and diversity in WFS shrimp. Ten genera, such as Vibrio , Candidatus Bacilloplasma, Photobacterium , and Aeromonas , were overrepresented in WFS, whereas 11 genera, including Shewanella , Chitinibacter , and Rhodobacter were enriched in control. The divergent changes in these populations might contribute the observation that a decline of pathways conferring lipoic acid metabolism and mineral absorption in WFS. Meanwhile, some sorts of metabolites, especially lipids and organic acids, were found to be related to the IM alteration in WFS. Integrated with multiomics and IMT, we demonstrated that significant alterations in the community composition, functional potentials, and metabolites of IM were closely linked to shrimp WFS. The distinguished metabolites which were attributed to the IM dysbiosis were validated by feed-supplementary challenge. Both homogenous selection and heterogeneous selection process were less pronounced in WFS microbial community assembly. Notably, IMT shrimp from WFS donors eventually developed WFS clinical signs, while the dysbiotic IM can be recharacterized in recipient shrimp. Conclusions Collectively, our findings offer solid evidence of the causality between IM dysbiosis and shrimp WFS, which exemplify the ‘microecological Koch’s postulates’ (an intestinal microbiota dysbiosis, a disease) in disease etiology, and inspire our cogitation on etiology from an ecological perspective. FQ9SoidJJGxv1orPr3YvZs Video abstract

Wetland restoration and creation efforts have been widely attempted as a way to compensate for wetland losses and to recover wetland functions; however, to date, there has been no comprehensive evaluation of the efficacy of soil carbon (C) and nitrogen (N) content recovery at a regional scale. This meta-analysis synthesizes 48 articles to identify the general patterns of soil C and N change after wetland restoration and creation in the United States. Our results indicate that, after 11–20 years, soil C and N in restored and created wetlands are still significantly lower by 51.7% and 50.3%, respectively, than those in natural wetlands. The soil C and N in restored wetlands recovered faster than in created wetlands. Furthermore, the soil C in restored organic flat and created depressional wetlands recovered more rapidly than in restored and created hydrologically open wetlands (riverine and tidal), respectively. Mean annual temperature and soil texture were recognized as two crucial abiotic factors affecting soil C and N recovery. Linear regression analysis revealed a positive relationship between the restoration and creation effect sizes on soil C and N, indicating that wetlands may alleviate N limitations intrinsically during C recovery processes.

The Pacific white shrimp, with the largest production in shrimp industry, has suffered from multiple severe viral and bacterial diseases, which calls for a more reliable and environmentally friendly system to promote shrimp culture. The “Aquamimicry system”, mimicking the nature of aquatic ecosystems for the well-being of aquatic animals, has effectively increased shrimp production and been adapted in many countries. However, the microbial communities in the shrimp intestine and surrounding environment that act as an essential component in Aquamimicry remain largely unknown. In this study, the microbial composition and diversity alteration in shrimp intestine, surrounding water and sediment at different culture stages were investigated by high throughput sequencing of 16S rRNA gene, obtaining 13,562 operational taxonomic units (OTUs). Results showed that the microbial communities in shrimp intestine and surrounding environment were significantly distinct from each other, and 23 distinguished taxa for each habitat were further characterized. The microbial communities differed significantly at different culture stages, confirmed by a great number of OTUs dramatically altered during the culture period. A small part of these altered OTUs were shared between shrimp intestine and surrounding environment, suggesting that the microbial alteration of intestine was not consistent with that of water and sediment. Regarding the high production of Aquamimicry farm used as a case in this study, the dissimilarity between intestinal and surrounding microbiota might be considered as a potential indicator for healthy status of shrimp farming, which provided hints on the appropriate culture practices to improve shrimp production.

In closed-loop supply chain systems for power battery remanufacturing, recycling and dismantling tasks will be relegated to third-party recyclers. This has significant disadvantages, inasmuch as the asymmetric exchange of information regarding the level of recycling capacity and effort after signing a contract fiscal risks to the manufacturers. The purpose of this paper is to study the “adverse selection” of recyclers and “moral hazards” hidden in their purported effort levels, based on Information Screening Models in the principal-agent theory. Our information screening model for revenue sharing will be presented, and subsequently verified using numerical simulation to demonstrate the impact of the screening contract on the expected returns of both parties. Our results show that the sharing coefficient of the remanufacturing revenue for low-capability recyclers is distorted downwards, and only truthful reporting can retain profits. High-capacity recyclers will obtain additional information while retaining profit. At the same time, as the proportion of high-capacity recyclers in the market increases, the expected return of the entrusting party increases. One critical area where this will impact the Chinese economy is in the area of new energy vehicles. We investigate a case study of our approach in new energy vehicles, which are being used to reduced CO 2 emissions, but have environmentally hazardous batteries that must be recycled safely and economically.

Non-structural carbohydrates (NSC) play an important role in yield formation. In this paper, the relationships of NSC accumulation and translocation with yield formation were investigated under elevated CO2 concentrations ([CO2]) and nitrogen (N) application rates. A japonica rice (Oryza sativa L.) cultivar, “Nanjing 9108,” was grown at three [CO2]—Ambient (T0), ambient + 160 μmol·mol−1 (T1), and ambient + 200 μmol·mol−1 (T2)—in open-top chambers (OTC), with three levels of N fertilizer application rates—10 gN·m−2 (N1), 20 gN·m−2 (N2), and 30 gN·m−2 (N3)—Which were set in OTCs using pot experiments. The results showed that the concentration of NSC (CNSC) and the total mass of NSC stored in stems (TMNSC) under T1 and T2 were higher than those in the T0 treatment, and the CNSC and TMNSC of N3 were lower than those of N1 and N2 at the heading stage. The CNSC and the TMNSC were significantly positively correlated with the stem biomass during the growth period and were notably negatively correlated with the N content in leaves (Nleaf) at the heading and filling stages. The seed setting rate was significantly positively related to the apparent transferred mass of NSC from stems to grains (ATMNSC) at the filling stage, while the relationship between yield and the ATMNSC was not statistically significant. Although there was no difference in the apparent contribution of transferred NSC to grain yield (ACNSC) between treatments, NSC stored in stems further accumulated obviously during the late filling stage, implying that the grain yield of “Nanjing 9108” was predominantly sink-limited. We concluded that elevated [CO2] improved the concentration of NSC at the rice heading stage. The interaction between elevated [CO2] and N fertilizer rates significantly influenced the concentration of NSC at the filling stage. Rice stems NSC reaccumulated at the late grain filling stage, which implies a restriction on NSC transference to grain.

Consumers focus on level of service while purchasing electronic products. This study focuses on consumer buying behavior. We determine the Stackelberg outcome for a market when a durable electronic product has three different forms: new product, remanufactured product and refurbished product. Under the dynamic game model, the optimal differential pricing strategy is implemented, and the double marginal effect is coordinated through a revenue-sharing contract and two toll contracts to increase the system’s revenue capacity. Our research shows that as the degree of consumer preference increases, the service differentiation of the three products is reduced. A lower level of consumer preference affects the pricing decision of new products and significantly affects the pricing of remanufactured products and refurbished products.

Collar structures are widely used to protect monopile foundations from scour, but their geometric obstruction hinders direct observation of the surrounding flow in physical experiments. To overcome this limitation, this study employs large-eddy simulation (LES) to investigate the flow characteristics around a monopile with collar protection. The LES model was validated against well-documented experimental data of pile-induced flow, confirming its reliability. Simulations under flat-bed and equilibrium scour conditions were conducted to evaluate the effects of the collar on time-averaged velocity, vortex dynamics, and turbulence intensity. The results show that the collar substantially weakens the upstream accelerated flow, suppresses horseshoe vortex formation, and reduces both the strength and extent of sidewall currents. Under flatbed conditions, the side-flow intensity decreases by 24.3% and the accelerated flow area is reduced by 93.3%. A counter-rotating vortex beneath the collar dissipates kinetic energy and simplifies the near-bed vortex system, thereby mitigating scour. However, the protective effect diminishes with increasing inflow velocity, with turbulence intensity rising by 159% for a 14% velocity increase. Overall, this study provides deeper insights into the protective mechanisms of collar structures, advancing the understanding of their effectiveness and limitations in monopile scour protection.

Background Nitrogen (N) addition profoundly alters soil phosphatase activities and induces widespread microbial phosphorus (P) limitation in grassland ecosystems. However, the long-term effects of different rates and chemical forms of N addition on soil acid phosphatase (ACP) activity and P availability remain unclear. Here, based on a 10-year N addition experiment, we investigated the effects of a range of N addition rates (0–50 g N m −2  yr −1 ) applied as either (NH 4 ) 2 SO 4 or urea on ACP activity in a northern China meadow steppe, with and without mowing management. Results We found that ACP activity remained unaffected by N addition until certain thresholds were reached (< 10 g N m −2  yr −1 for [(NH 4 ) 2 SO 4 ] and < 20 g N m −2  yr −1 for urea), beyond which it declined sharply. (NH 4 ) 2 SO 4 exerted a stronger inhibitory effect on ACP activity compared to urea, with the former primarily acting through soil acidification and the latter through a decrease in bacterial diversity. In contrast, mowing regimes did not significantly alter ACP activity under either N form. Conclusions Our findings underscore the necessity of accounting for both N addition rates and N forms when assessing atmospheric N deposition impacts on soil phosphatase activity. These results inform the development of management strategies to mitigate declines in soil enzyme activity and enhance the long-term sustainability of grassland ecosystems.

Routing in mobile social networks is a challenging task due to the characteristic of intermittent connectivity, especially when the nodes behave selfishly in real world. Selfish behaviors of node always influence its altruism to provide forwarding service for others and degrade network performance strongly. In this paper, to address the selfishness problem in MSNs, we propose a service-based selfish routing protocol, SSR. When making forwarding decision, SSR employ user altruism and the amount of service that the relay nodes provide. User altruism is determined by the social selfishness and the individual selfishness. The services include pairwise services and social services, which is also considered as the incentives to stimulate node to be more cooperative. The more services the node provides, the more chance the node has to be served. The node with higher altruism and fewer services is the preferred relay node. Simulation results show SSR achieves better performance when the user altruism is low and demonstrate the effectiveness of the service-based scheme.

Routing in vehicular network is a challenging task due to the characteristic of intermittent connectivity, especially when nodes behave selfishly in the real world. Previous works usually assume that all nodes in the network are willing to forward packets for others, which is impractical in real world. Selfish behaviors of nodes would degrade network performance greatly. In this paper, we propose SCR, a social contribution-based routing protocol, for selfish vehicular network. When making forwarding decision, SCR considers both the delivery probability to the destination and the social contributions of the relay node. The delivery probability is determined by the social relations among nodes and social contribution is used as the incentive to stimulate selfish nodes to be more cooperative, which consists of reciprocal contribution and community contribution. The node with higher delivery probability and lower social contributions is the preferred candidate for the next hop. Simulation results show that SCR achieves better performance than other social routing protocols with the incentive scheme.