Capacity Performance Research Articles

Artificial neural networks computing system for Ree-Eyring hybrid nanofluid flow over a solar panel sheet: Hamilton–Crosser model

Background: The utilisation of solar radiation for generating thermal energy has garnered a significant amount of attention, especially with the rising demand for sustainable power and heating sources. Nanofluids appeared as promising options for enhancing the efficiency of solar-thermal systems owing to their superior heat transmission properties. In this aspect, the present research deals with Ree-Eyring hybrid nanofluid ( SWCNT − MWCNT / H 2 O ) flow in the presence of thermal radiation effect and shape factor to examine the thermal behaviour in solar panels. Additionally, the innovation lies in the field of artificial neural networks and fluid flow analysis as an integrated approach. Methodology: The considered physical interpretation is stated in the form of nonlinear partial differential equations. To facilitate the computation process, the governing equations turned into nondimensional ordinary differential equations with the help of invariant transformations. The converted equations are treated scientifically using the NDSolve methodology, which automatically adjusts the step size. In further, an artificial neural network-based multi-layer perceptron deploying the Levenberg–Marquardt model is employed to forecast the measurements of physical quantities. Core Findings: The markable outcomes from this advanced work imply that the stretching surface has an important role in analysing the thickness of the boundary layer. The improving Weissenberg number enhances the boundary layer thickness, leading to a magnification in the momentum field of the non-Newtonian fluid. In addition, thermal radiation is captured as a second significant influence on temperature distribution. It follows that enhancing the Radiation parameter upsurges the thermal layer. The variation of the volume fraction of nanoparticles resulted in higher temperatures due to the Hamilton–Crosser model, which involves the cylindrical shape of the nanoparticles. Validation: The validation of the current work is explored by comparing it with the existing literature in certain instances. The incorporation of multi-layer perceptron for hybrid nanofluid delivers the performance capacity of high prediction with the error 4.83E−06, 1.11E−10 and 2.4E−08. Applications: The existing optimisation approach provides a new perspective on solar-powered offshore, solar vehicles, solar-powered charging stations, solar power greenhouse and solar water pump implementation.

Effect of Gardeniae Fructus Powder on Growth Performance, Antioxidant Capacity, Intestinal Barrier Function, and Colonic Microbiota of Weaned Piglets.

The present study aimed to explore the effect of GF powder on the growth performance, diarrhea rate, antioxidant and immune capacity, and intestinal health of weaned piglets. A total of 144 weaned piglets (8.29 ± 0.11 kg) at 21 d old were randomly assigned to four groups, with each treatment consisting of six replicate pens, with six piglets per pen, and each pen containing three barrows and three gilts. The piglets were fed a basal diet supplement with 0%, 0.4%, 0.6%, and 0.8% GF powder (n = 36). Our results indicated that compared with the basal diet, the F/G and diarrhea rate were remarkably decreased in the 0.8% GF group (p < 0.05). Serum biochemical parameters showed that supplementation with GF significantly increased the content of HDL-C (0.6 and 0.8% levels), IL-6 (0.8% level), IL-10 (0.4, 0.6, and 0.8% levels), Ig G (0.4% level), and Ig A (0.8% level) compared with the basal diet (p < 0.05). The index of antioxidant capacity showed that compared with a basal diet, supplementation with GF significantly decreased serum MDA content (0.4% and 0.8% levels) and jejunal and ileal MDA content (0.4%, 0.6%, and 0.8% levels) (p < 0.05). Additionally, compared with the basal diet, supplementation with GF significantly increased serum and ileal T-AOC content (0.4%, 0.6%, and 0.8% levels), serum T-SOD content (0.4% and 0.8% levels), ileal T-SOD content (0.4%, 0.6%, and 0.8% levels), CAT content (0.4%, 0.6%, and 0.8% levels), and jejunal GSH-Px content (0.8% level) (p < 0.05). The results of gene expression indicate that compared with the basal diet, supplementation with GF significantly increased Nrf 2 (0.4% level), NQO (0.4% level), SOD 1 (0.4% and 0.8% levels), and GCLC (0.4% level) and GCLM (0.8% level) abundance in jejunal mucosa; supplementation with GF significantly increased Nrf 2 (0.4%, 0.6%, and 0.8% levels), HO-1 (0.4% level), NQO (0.8% level), SOD 1 (0.4% and 0.8% levels), and GCLC (0.4% level) and GCLM (0.8% level) abundance in ileal mucosa (p < 0.05). Ulteriorly, the present results indicate that supplementation with GF at the 0.8% level significantly increased the villus height in the jejunum and ileum as well as the villus/crypt ratio in the ileum compared with the basal diet (p < 0.05). Compared with the basal diet, 0.4% GF significantly increased Occludin gene expression in ileal mucosa (p < 0.05), 0.6% GF significantly increased ZO-1, Claudin-1, and Occludin gene expression in jejunal mucosa (p < 0.05), and 0.8% GF significantly increased ZO-1 and Occludin gene expression in jejunal mucosa along with Occludin expression in ileal mucosa (p < 0.05). Furthermore, colonic microbiota composition showed that Shannon, observed species, and Chao 1 indices were significantly increased in the 0.8% GF group compared with the basal diet (p < 0.05). At the phylum level, in comparison with the basal diet, the relative abundance of Firmicutes significantly decreased in the 0.4%, 0.6%, and 0.8% GF groups, and Bacteroidetes increased in the 0.8% GF group (p < 0.05). At the genus level, compared with the basal diet, 0.6% and 0.8% GF significantly increased Prevotella abundance, and 0.6% GF significantly decreased Coprococcus abundance (p < 0.05). At the species level, compared with the basal diet, 0.8% GF significantly increased Prevotella copri abundance, and 0.4%, 0.6%, and 0.8% GF significantly decreased Blautia obeum abundance (p < 0.05). In summary, a dietary supplement with 0.8% Gardeniae Fructus powder significantly decreased the F/G and diarrhea rate and improved antioxidant capacity and intestinal barrier function, which may be associated with the improvement of the relative abundance of Prevotella copri. These findings indicate that Gardeniae Fructus powder may be used as a feed additive in swine weaning.

Dietary Fiber-Rich Spartina anglica Improves Intestinal Health and Antioxidant Capacity of Zhedong White Geese.

Spartina anglica (SA), a plant rich in dietary fiber, has demonstrated considerable potential for enhancing gut health and antioxidant capacity in animals. This study investigates the integration of SA as a novel dietary ingredient for Zhedong white geese, with a specific focus on evaluating its effects on growth performance, nutrient digestibility, antioxidant capacity, intestinal health, and cecal microbiota composition. A total of 360 1-day-old Zhedong white geese with an average weight of 114.94 ± 0.81 g were randomly allocated to 4 dietary treatments, with 6 replicates per treatment and 15 geese per pen. The 4 dietary treatments included different SA supplement levels: a control group receiving a basal diet (CON), and three experimental groups supplemented with 3% SA (SA3), 6% SA (SA6), and 12% SA (SA12). Supplementation with 6% SA significantly enhanced the final body weight, average daily gain, and feed conversion ratio (FCR) compared to the CON group (p < 0.05). In contrast, the SA12 group exhibited reduced digestibility of crude protein and ether extract, relative to the SA3 and SA6 groups (p < 0.05). The highest antioxidant capacity was observed in the SA6 and SA12 groups, while the lowest was recorded in the CON group. SA supplementation did not significantly influence serum biochemical parameters or organ indices but increased cecum length (p < 0.05). Notably, SA supplementation markedly improved intestinal morphology, although excessive levels appeared to compromise these benefits. Additionally, SA supplementation significantly enhanced the richness and diversity of cecal microbiota and increased short-chain fatty acid concentrations. In conclusion, SA at an optimal supplementation level of 6% may be effectively utilized in Zhedong white geese diets to improve growth performance, gut health, and antioxidant capacity.

Impact of Feeding Frequency on Growth Performance and Antioxidant Capacity of Litopenaeus vannamei in Recirculating Aquaculture Systems.

Feeding frequency is crucial for the growth and development of white shrimp (Litopenaeus vannamei) at various life stages. Although higher feeding frequencies can enhance growth, manual feeding methods significantly increase labor costs. Automatic feeding systems offer a cost-effective and efficient alternative, yet their application in intensive shrimp culture remains under-researched. This study evaluates different feeding frequencies for L. vannamei in intensive aquaculture tanks, focusing on growth performance, survivability, feed utilization, digestive and antioxidant capacities, and economic viability. Juvenile shrimp (3.85 ± 0.3 g) were cultured for 63 days with feeding frequencies of 6, 8, 10, and 12 times/day (A6, A8, A10, and A12 groups, respectively) using automatic feeders, with a control group fed manually 6 times/day (M6). Results indicated that automatic feeding significantly improved final body weight, specific growth rate, and feed conversion ratio compared to manual feeding. Among automatic feeding groups, A6 and A8 showed optimal performance, with a quadratic regression identifying 7.83 times/day as the optimal frequency. While digestive enzyme activity remained consistent across groups, A6 and A8 demonstrated significantly higher antioxidant enzyme levels (superoxide dismutase (SOD) and glutathione peroxidase (GPx)) and lower lipid peroxidation (MDA), suggesting superior digestive and antioxidant capacities. Pearson's correlation confirmed a positive relationship between SOD and GPx. Economically, the A8 group achieved the highest profitability. Consequently, a feeding frequency of 6-8 times/day using automatic feeders is recommended as an optimal and feasible strategy for intensive white shrimp culture in this life stage.

Synergistically Boosted Na+ Migration and Deep Desodiation Stability of NASICON Cathode via High Entropy Regulation.

Mn-containing sodium superionic conductor (NASICON) compounds have shown considerable potential as cathode for sodium-ion batteries (SIBs) owing to higher working voltage (V5+/V4+: 3.9V), lower cost, and lower toxicity compared to full vanadium-based NASICON Na3V2(PO4)3. Taking Na3.3V1.7Mn0.3(PO4)3 (NVMP) as an example, its practical application is still restricted by poor electronic conductivity, sluggish intrinsic Na+ diffusion, and poor high-voltage stability. In this work, a high entropy strategy is proposed to develop Na3.3V1.613Mn0.3(Cr, Fe, Co, Ni, Zr)0.1(PO4)3 (HE-NVMP) cathode for not only enabling more and rapid Na+ migration but also significantly improving deep desodiation stability. Based on theoretical calculations and experimental findings, such high entropy modification can efficiently alter the coordination environments of both V/Mn and Na sites for reducing Na+ diffusion energy barrier, increasing the occupancy of Na+ at Na(2)sites, and consolidating the structure stability. Thus, the obtained HE-NVMP delivers superior high-rate capability (91.7 mAh g-1) up to 50 C and excellent cycling performance (capacity retention: 81.2%) after 10000 cycles at 20 C at the cutoff voltage of 4.1V. More importantly, such cathode also exhibits superior sodium storage properties at a higher cutoff voltage (4.5V) with electrochemical polarization with 75% reduction at 1 C and higher capacity retention of 80.3% after 2000 cycles at 20 C compared to pristine counterpart, indicating a great potential for practical rechargeable batteries with excellent overcharge resistance capability.

Effects of Different Levels of Lycium barbarum Flavonoids on Growth Performance, Immunity, Intestinal Barrier and Antioxidant Capacity of Meat Ducks.

Background: In vitro findings on the biological functions of Lycium barbarum flavonoids (LBFs) as feed additives are limited. This study aimed to explore the effects of different concentrations of LBFs on the growth performance, immune function, intestinal barrier, and antioxidant capacity of meat ducks. A total of 240 one-day-old male meat ducks were randomly allocated to four groups, each receiving a basal diet supplemented with 0 (control), 250, 500, or 1000 mg/kg of LBFs for 42 d. Results: The results showed that dietary supplementation with 500 mg/kg of LBFs resulted in a significant increase in average daily feed intake, body weight, average daily gain, and feed conversion ratio. Dietary supplementation with 500 or 1000 mg/kg of LBFs resulted in significant decreases in serum levels of D-lactic acid and lipopolysaccharide. Dietary supplementation with 500 mg/kg LBFs significantly decreased diamine oxidase activity and enhanced the activities of catalase, total antioxidant capacity, and glutathione peroxidase in the jejunal mucosa, as well as the activity of total superoxide dismutase and the content of glutathione in the ileal mucosa, while significantly lowering the content of malondialdehyde in the ileal mucosa. Dietary supplementation with 500 mg/kg LBFs significantly up-regulated the mRNA expression of genes associated with intestinal barrier function and antioxidant capacity in the jejunal and ileal mucosa, as well as the protein expression of these antioxidant genes, and led to a significant reduction in the mRNA expression of pro-apoptotic and inflammatory-related genes. Conclusions: The addition of LBFs to the diet improved the growth performance, intestinal barrier function, immune response, and antioxidant capacity of the ducks, which may be closely associated with the activation of the Nrf2 signaling pathway and the inhibition of the NF-κB signaling pathway. The optimal dietary inclusion level of LBFs in ducks was 500 mg/kg.

Activities of Daily Living in a Iranian Man With Cervical Spinal Cord Injury Based on the Model of Human Occupation

Background and Objectives: Since all aspects of occupational performance are affected by cervical spinal cord injury (SCI), one of the goals of occupational therapy for these clients is to restore the abilities and routines necessary for independence in activities of daily living (ADL). The model of human occupation (MOHO) seems to help occupational therapists develop a framework for clinical reasoning about the living conditions of people with cervical SCI emphasizing the interaction between volition, habituation, and performance capacity. This study aims to investigate the use of MOHO in occupational therapy for cervical SCI and focuses on the significance of comprehending and adjusting to these specific needs to improve their participation in purposeful daily activities leading to occupational adaptation. Case Presentation: The focus of this study is on a 26-year-old man who experienced a cervical SCI at the C6 level due to a diving accident. He exhibits varying degrees of motor and sensory deficits, characterized by partial upper extremity function and complete loss of function in the lower extremities. The client expresses a strong desire to develop skills for safe and effective transfers, the need for strategies that promote community reintegration and social interaction, and adaptive strategies and utilize assistive devices that will enable him to perform ADLs with greater independence. Conclusion: Because in a person with cervical SCI, values and interests, internalized roles, and performance capacities are affected by impairment, designing a program based on the MOHO will help occupational therapists perform more effectively.

Inclusion of Ora-Pro-Nóbis (Pereskia aculeata) Leaf Meal in the Diet of Adult Nile Tilapia Improves Growth Performance and Intestinal Absorption Capacity Without Compromising Metabolic and Hematological Variables.

Corn and soybeans are commodities and ingredients of global interest, whose prices fluctuate based on global demands. In this sense, this study aimed to assess ora-pro-nóbis (Pereskia aculeata) leaf meal (OLM) as an alternative to be included in the diets of Nile tilapia (Oreochromis niloticus). The optimal inclusion level of OLM in tilapia diets is investigated herein, aiming to improve their growth performance and health. Five diet variations containing OLM (0%, 5%, 10%, 15%, and 20%) were tested. Feed conversion and protein efficiency rates in the 5% and 10% OLM groups were statistically similar to the control group (p ≤ 0.05) and lower in the 15% and 20% OLM groups. Fish fed 5% and 10% OLM diets showed better feed efficiency, while higher OLM levels (15% and 20%) led to reduced carcass protein and ether extract levels. Increasing OLM levels enhanced intestinal villi height and area, associated with improved nutrient absorption and decreased liver fat degeneration, suggesting dietary adaptation and healthier liver conditions. Thus, OLM can be included up to 10% in tilapia diets, improving their growth performance, feed efficiency, and intestinal absorptive capacity without adversely affecting other parameters.

Dual-Functional SnO2-CNT-PANI||PP||SnO2 Separator for Enhanced Lithium-Sulfur Battery Stability and Capacity

Lithium-sulfur batteries (LSBs) provide high capacity and energy density for advanced energy storage but encounter performance and safety issues due to lithium polysulfides (LiPSs) dissolution and dendrite formation. This study introduces a dual-functional SnO2-CNT-PANI||PP||SnO2 separator (DF-SNCPS) aimed at improving the stability and safety of LSBs. The separator includes a SnO2-CNT-PANI layer on the sulfur cathode side for enhanced electrical conductivity and polysulfide adsorption and a SnO2 nanoparticle (nano-SnO2) layer on the lithium anode side to regulate lithium-ion concentration and inhibit dendrite growth. Density functional theory (DFT) and the phase field method have verified the relevant material's catalytic performance and dendrite suppression ability. These methods have provided a comprehensive understanding of the underlying mechanisms, providing auxiliary explanations for their role in catalyzing polysulfide conversion and suppressing lithium dendrite growth. This innovative design mitigates the shuttle effect and enhances cyclic stability and sulfur utilization, achieving a notable cyclic performance with a capacity retention of 0.05% per cycle over 800 cycles at 1C. The synergistic effects of the modified separator present a viable pathway for LSB commercialization.

Seismic performance and shear capacity theory of assembled steel reinforced recycled concrete frame under earthquake action

Seismic performance and shear capacity theory of assembled steel reinforced recycled concrete frame under earthquake action

The influence of diamond grain sizes on the tribological performance and ultimate loading capacity of polycrystalline diamond self-mated friction pairs under water lubricated condition

The influence of diamond grain sizes on the tribological performance and ultimate loading capacity of polycrystalline diamond self-mated friction pairs under water lubricated condition

Si-doped NASICON-type Li1.4Al0.4Ti1.6(PO4)3 solid electrolytes for enhanced stability and performance of Li-CO2 batteries

Li-CO2 batteries (LCBs) have attracted significant research interest owing to their potential as energy storage devices and their contribution to carbon neutrality. In this study, we synthesized a solid electrolyte using Si-doped Li1.4Al0.4Ti1.6(PO4)3 (LASTP), by incorporating Si into the NASICON-structured LATP. Through Si doping, P in the tetrahedral PO4 units within the NASICON framework is substituted with Si, and bridging oxygen bonds are formed after high-temperature heat treatment The LASTP powder synthesized via a solution-based method exhibited uniform particle size and composition, and the resulting pellet achieved high densification and the formation of interconnected structures. The pellet exhibited an ionic conductivity of approximately 8.8 × 10-4S/cm at 25℃. The LCB utilizing LASTP demonstrated a maximum discharge capacity of 23,887mAh/g and successfully operated for 200 cycles at a current density of 100mA/g with a cut-off capacity of 500mAh/g. The post-cycling analysis of the cathode confirmed the reversible reactions of the LCB. Additionally, comparative post-cycling XPS analysis of LATP and LASTP revealed that Si doping in LASTP mitigated the reduction of Ti4+ to Ti3+, thereby enhancing the chemical stability of the solid electrolyte. Also, the structural stability of the solid electrolyte was enhanced owing to the formation of new bonds, surpassing the cycle performance and full-depth capacity of LCBs using conventional solid electrolytes. The introduction of structurally and chemically stabilized LASTP enabled the realization of long-lasting, high-capacity LCBs.

Supplemented with Astragalus dregs improves growth performance, immunity, and antioxidant capacity in fattening pigs

Supplemented with Astragalus dregs improves growth performance, immunity, and antioxidant capacity in fattening pigs

Supplementation of VLT and marine-derived probiotic BA-9 promotes the growth performance and antioxidant capacity at early life of ruminants

Supplementation of VLT and marine-derived probiotic BA-9 promotes the growth performance and antioxidant capacity at early life of ruminants

Audio Watermarking System in Real-Time Applications

Watermarking is widely employed to protect audio files. Previous research has focused on developing systems that balance performance criteria, including robustness, imperceptibility, and capacity. Most existing systems are designed to work with pre-recorded audio signals, where the characteristics of the host signal are known in advance. In such cases, processing time is not a critical factor, as these systems generally do not account for real-time signal acquisition or report tests for real-time signal acquisition nor report the elapsed time between signal acquisition and watermarking output, known as latency. However, the increasing prevalence of audio sharing through real-time streams or video calls is a pressing issue requiring low-latency systems. This work introduces a low-latency watermarking system that utilizes a spread spectrum technique, a method that spreads the signal energy across a wide frequency band while embedding the watermark additively in the time domain to minimize latency. The system’s performance was evaluated by simulating real-time audio streams using two distinct methods. The results demonstrate that the proposed system achieves minimal latency during embedding, addressing the urgent need for such systems.

Force-Motion Coupled Mechanism Synthesis Method of Heavy Load Parallel Kinematic Mechanism for Multi-DoF Forming Process

Abstract At present, the design of parallel kinematic mechanism (PKM) generally starts from type synthesis based on the motion pattern and then the dimensions are synthesized based on performance requirements The synthesized type of PKM with optimal load-bearing capacity is hard to determine because the above type synthesis is just based on the motion pattern and the number of synthesized types of PKM is huge. Therefore, this paper aims to investigate a force-motion coupled mechanism synthesis method for heavy load PKM with optimal motion performance and load-bearing capacity. First, the optimal load-bearing conditions for PKM are derived, namely, the wrench screw of a limb is parallel to the external force acting on the moving platform and is reciprocal with the wrench of the actuator. Furthermore, a novel force-motion coupled type synthesis method is proposed, in which the wrench of the limb is added to the constrained screw system. In this situation, the synthesized PKM is singular. Therefore, dimension synthesis is carried out based on the workspace, and a near-singular 6-PHSS PKM is then synthesized. Finally, a novel multi-DoF forming machine with a forming force of 6000 kN is developed. Compared with the Stewart platform (6-UPS PKM), the maximum forces of the actuator and limb of the new near-singular 6-PHSS PKM were reduced by 80% and 10%, respectively, validating the proposed force-motion coupled synthesis method for heavy load PKM.

Perceived Nuisance Caused by Air Pollution on Amateur Endurance Athletes/Exercisers: Development of a Psychometric Scale

Air pollution is a major health-related environmental challenge that affects many aspects of people’s daily lives. For amateur endurance athletes/exercisers, air pollution can cause, apart from the common health issues, reduced performance capacity during training and races. The most significant inconveniences that these amateur athletes/exercisers have to deal with, are related to breathing difficulty, increased heart rate, cough or respiratory problems, and eye or nose discomfort. The aim of this study is to create a psychometric scale that estimates the nuisance/discomfort that amateur endurance athletes/exercisers (triathlon, cycling, running, swimming) feel during their training, under conditions of increased air pollution, and to see how this is linked to demographic characteristics. The main overall purpose is the identification of possible correlation between air pollution and reduced athletic performance, as well as between air pollution and the wellbeing of amateur endurance athletes/exercisers, and to thus enable recommendations on training in a polluted environment. To this aim, a questionnaire was developed, initially through a pilot stage. The fully developed scale was provided to two hundred and ninety-two (292) amateur endurance athletes/exercisers for an exploratory factor analysis to be carried out. The exploratory factor analysis indicated three (3) factors accounting for 37.11% of the overall variance. The first factor “Physical discomfort” included nine (9) questions, the second factor “Lack of discomfort” five (5) questions, and the third factor “No general discomfort” six (6) questions. The degree of reliability was satisfactory, since Cronbach’s a coefficient was 0.841 for the first factor, 0.642 for the second, and 0.766 for the third factor. Subsequently, fluctuation analysis (ANOVA), multivariate fluctuation analysis (MANOVA), and Pearson’s r coefficient were used to indicate correlations between the independent variables and the three factors identified. Correlation between discomfort due to air pollution and the place of residence, as well as the presence or absence of allergies, was indicated. On the other hand, there were no significant statistical differences between gender, type of sport, the volume of training, the presence or not of respiratory problems, and smoking. Overall, the scale can be considered both valid and reliable.

Wooden Structures in Sustainable Design: AI-Based Energy Efficiency and Environmental Impact

This study aims to analyze the integration of wooden structures into green building designs and the effects of this integration on sustainable architecture. Wood, as a renewable building material, offers advantages such as low carbon footprint, energy efficiency and environmental sustainability. The study examines the thermal performance, energy efficiency and acoustic properties of wooden structures and evaluates the potential of these structures as a sustainable solution in future green building projects. In the study, select wooden structures such as Brock Commons Tallwood House (Canada), Mjøstårnet (Norway), Treet (Norway), Forté Building (Australia) and The Edge (Netherlands) were analyzed. Artificial intelligence-supported simulations were performed on these structures and evaluations were made in terms of thermal performance, energy efficiency and carbon storage capacity. Artificial intelligence methods were used to optimize energy efficiency and reduce environmental impacts. For example, EnergyPlus software and artificial intelligence techniques such as genetic algorithms were used for energy modeling to optimize the performance of buildings in different climatic conditions. Life Cycle Analysis (LCA) has determined that the carbon storage capacity of wooden structures is superior to traditional materials such as steel and concrete. The results show that wooden structures reduce energy consumption, minimize heating and cooling needs, increase acoustic comfort and contribute to environmental sustainability. In particular, structures such as Mjøstårnet and The Edge are exemplary in both reducing carbon emissions and saving energy.

Physiological and intestinal microbiota responses of sea cucumber Apostichopus japonicus to various stress and signatures of intestinal microbiota dysbiosis.

Identifying the signatures of intestinal dysbiosis caused by common stresses is fundamental to establishing efficient health monitoring strategies for sea cucumber. This study investigated the impact of six common stress experienced frequently in aquaculture on the growth performance, intestinal homeostasis and microbiota of sea cucumber, including thermal (23°C), hypoosmotic (22‰ salinity), ammonium (0.5 mg/L NH4 +-N), and nitrite (0.25 mg/L NO2 --N) stress exposure for 30 days, as well as starvation and crowding (6 kg/m3 density) stress exposure for 60 days. Results demonstrated that all stress led to reduced growth performance and digestive capacity of sea cucumber, along with varying degrees of oxidative stress and immune responses. Various stresses significantly altered the diversity, community structure (except for crowding stress), and composition of intestinal microbiota. The ratios of Bacteroidota: Proteobacteria (B: P) and Firmicutes: Proteobacteria (F: P) declined markedly compared to the control. Potentially pathogenic bacteria of Shewanellaceae, Vibrionaceae, and Moraxellaceae significantly increased under crowding, ammonium, and nitrite stress, respectively, whereas beneficial microbes of Achromobacter and Rhodobacteraceae were, respectively, enriched under hypoosmotic and starvation stresses. The complexity and stability of microbial ecological networks were further altered by these stresses. KEGG predictions revealed the reduced functional pathways of intestinal microbiota involved in host immunity under different stresses. Correlation analysis further confirmed a strong link between microbiota response and host immunity under different stresses. The increased abundance of Verrucomicrobia species could also be identified as the sensitive indicator for diagnosing whether the host was under stressful pressure by random forest analysis.

Effects of dietary carbohydrate and lipid levels on growth performance, hepatic histology and antioxidant capacity and flesh texture of mandarin fish (Siniperca chuatsi).

In this study, nine isonitrogenous experimental diets containing graded levels of carbohydrates (40 g/kg, 80 g/kg and 120 g/kg) and crude lipids (80 g/kg, 120 g/kg and 160 g/kg) were formulated in a two-factor (3 × 3) orthogonal design. A total of 945 mandarin fish with similar body weights were randomly assigned to twenty-seven tanks, and the experiment diets were fed to triplicate tanks twice daily for 10 weeks. Results showed that different dietary treatments did not significantly affect the survival rate and growth performance of mandarin fish. However, high dietary lipid and carbohydrate levels significantly decreased the protein content of the whole body and muscle of cultured fish. The lipid content of the whole body, liver and muscle all significantly increased with increasing levels of dietary lipid, while only liver lipid level was significantly affected by dietary carbohydrate level. Hepatic glycogen content increased significantly with increasing dietary carbohydrate levels. As to liver antioxidant capacity, malondialdehyde content increased significantly with increasing dietary lipid or carbohydrate content, and catalase activity showed an opposite trend. Superoxide dismutase activity increased significantly with increasing levels of dietary lipid but decreased first and then increased with increasing dietary carbohydrate levels. Additionally, the increase in both dietary lipid and carbohydrate levels resulted in a significant reduction in muscle hardness. Muscle chewiness, gumminess and shear force were only affected by dietary lipid levels and decreased significantly with increasing dietary lipid levels. In conclusion, considering all the results, the appropriate dietary lipids and carbohydrate levels for mandarin fish were 120 g/kg and 80 g/kg, respectively.