Synergistic effects of tilapia head protein hydrolysate and walnut protein hydrolysate on the amelioration of cognitive impairment in mice.

BACKGROUND: Cognitive impairment (CI) is a significant public health concern, and bioactive peptides have shown potential as therapeutic agents. However, information about their synergistic effects on cognitive function is still limited. Here, we investigated the synergistic effects of tilapia head protein hydrolysate (THPH) and walnut protein hydrolysate (WPH) in mitigating CI induced by scopolamine in mice. RESULTS: The results showed that the combined supplementation of THPH and WPH (mass ratio, 1:1) was superior to either individual supplement in enhancing spatial memory and object recognition abilities in CI mice, and significantly lessened brain injury in CI mice by alleviating neuronal damage, reducing oxidative stress and stabilizing the cholinergic system. In addition, the combined supplementation was found to be more conducive to remodeling the gut microbiota structure in CI mice by not only remarkably reducing the ratio of Firmicutes to Bacteroidota, but also specifically enriching the genus Roseburia. On the other hand, the combined supplementation regulated the disorders of sphingolipid and amino acid metabolism in CI mice, particularly upregulating glutathione and histidine metabolism, and displayed a stronger ability to increase the expression of genes and proteins related to the brain-derived neurotrophic factor (BDNF)/TrkB/CrEB signaling pathway in the brain. CONCLUSION: These findings demonstrate that tilapia head and walnut-derived protein hydrolysates exerted synergistic effects in ameliorating CI, which was achieved through modulation of gut microbiota, serum metabolic pathways and BDNF signaling pathways. © 2024 Society of Chemical Industry.

Rumen bacteria and meat fatty acid composition of Sunit sheep reared under different feeding regimens in China.

BACKGROUND: Rumen bacteria play a critical role in feed degradation and productivity. This study evaluated the impact of feeding regimen on the rumen microbial populations and fatty acid composition of the meat of sheep. Twenty-four Sunit sheep were raised on a grass pasture from birth to 9 months of age, at which time they were randomly divided into two feeding groups: pasture feeding (PF) and barn feeding (BF). Sheep in the PF group were allowed to graze freely on wild grassland for 3 months. Sheep in the BF group were confined for 3 months to a dry barn, in which they roamed freely with corn straw and corn. RESULTS: Sheep in the PF group had greater rumen bacteria diversity. The relative abundances of the genera Butyrivibrio_2, Saccharofermentans and Succiniclasticum were increased, and that of the genus RC9_gut_group was decreased, in the PF compared to the BF sheep. The n-3 polyunsaturated fatty acid contents were greater in meat from PF sheep than from BF sheep. In addition, the α-linolenic acid (C18:3 n-3, ALA) and conjugated linoleic acid (CLA) contents were positively correlated with the abundance of Butyrivibrio_2. CONCLUSION: Grazing may improve the diversity of rumen bacteria and increase the proportion of ALA and CLA in sheep meat. © 2020 Society of Chemical Industry.

Accumulation, biodegradation and toxicological effects of N-ethyl perfluorooctane sulfonamidoethanol on the earthworms Eisenia fetida exposed to quartz sands.

While N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE) is a precursor of perfluorooctane sulfonate (PFOS), its bioaccumulation, transformation and toxicological effects in earthworms (Eisenia fetida) exposed to quartz sands are poorly understood. The present study showed that except for parent EtFOSE, N-ethylperfluorooctane sulfonamide acetate (EtFOSAA), N-ethyl perfluorooctane sulfonamide (EtFOSA), perfluorooctane sulfonamide acetate (FOSAA), perfluorooctane sulfonamide (FOSA) and PFOS were detected in earthworms, with EtFOSAA as the primary biotransformation product. The biota-to-sand accumulation factor (BSAF) and uptake rate coefficient (ku) of EtFOSE were 5.7 and 0.542/d, respectively. The elimination rate constants (ke) decreased in the order EtFOSA (0.167/d) ∼ FOSAA (0.147/d) > FOSA (0.119/d) ∼ EtFOSAA (0.117/d) > EtFOSE (0.095/d) > PFOS (0.069/d). No significant effects were observed in malondialdehyde (MDA) contents and acetylcholinesterase (AChE) activities between EtFOSE treatments and controls. EtFOSE could cause significant accumulation of reactive oxygen species (ROS) in earthworms. Peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were significantly activated by 41.4-74.3%, 37.2-44.4% and 32.4-52.3% from day 4-10, respectively, while 8-Hydroxy-2-deoxyguanosine (8-OHdG) levels were elevated by 47.7-70.3% from day 8-10, demonstrating that EtFOSE induced oxidative stress and oxidative DNA damage in earthworms. Significant increase of glutathione-S-transferase (GST) with 41.6-62.8% activation (8-10 d) gave indirect evidence on the conjugation of EtFOSE or its corresponding metabolites during phase II of detoxication. This study provides important information on the fate and potential risks of EtFOSE to terrestrial invertebrates.

Biotransformation and responses of antioxidant enzymes in hydroponically cultured soybean and pumpkin exposed to perfluorooctane sulfonamide (FOSA).

Perfluorooctane sulfonamide (FOSA) is an important perfluorooctane sulfonate (PFOS) precursor used for commercial applications. In order to investigate the transformation and responses of selected antioxidant and degradation enzymes of FOSA in the plants, in vivo exposure of soybean (Glycine max L. Merrill) and pumpkin (Cucurbita maxima L.) were conducted in the solution-plant microcosms. FOSA was readily taken up by soybean and pumpkin roots and translocated to shoots, and metabolized to PFOS, perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS). Although morphological and biomass effects were not visible, significant changes in oxidative stress response were observed except for thiobarbituric acid reactive substances (TBARS). Superoxide dismutase (SOD) and peroxidase (POD) activities were significantly increased by 19.2-30.8% and 19.2-20.7% in soybean (8-12 d) respectively, and increased by 39.2-92.8% and 21.1-37.6% in pumpkin (3-12 d) respectively, suggesting an activation of the antioxidant defense system in the plants exposed to FOSA. Glutathione-S-transferase (GST) activities were decreased in soybean (2-12 d) with 9.0-36.1% inhibition and increased in pumpkin (3-12 d) with 22.5-47.3% activation respectively; cytochrome P450 (CYP450) activities were increased markedly in soybean and pumpkin with 13.2-53.6% and 26.7-50.2% activation respectively, giving indirect evidences on the involvement of CYP450 and GST in degradation of FOSA in plants.

Cloning and expression analysis of an MYB gene associated with calyx persistence in Korla fragrant pear.

KEY MESSAGE: We isolated an MYB-like gene from Korla fragrant pear using differential display RT-PCR. Expression of this gene in flowers appears to be correlated with calyx persistence. Korla fragrant pear (Pyrus brestschneideri Rehd) is an economically important pear cultivar in China. A persistent calyx results in the deformation of the fruit. We used differential display RT-PCR to obtain 42 cDNA fragments from Korla fragrant pear flowers. Alignments of nucleotide and amino acid sequences suggested that two fragments (kfp1and kfp4) were related to calyx persistence. The fragments were 78% homologous with Malus × domestica SPL transcription factor (SPL3) and 83% homologous with Malus × domestica MYB transcription factor (MYB12). The complete cDNA sequence of kfpMYB was determined to clarify the role of MYB in calyx persistence. kfpMYB contained a 116 bp 5'-UTR, a 1122 bp open reading frame encoding 374 amino acids, and a 319 bp 3'-UTR. The nucleotide and amino acid sequences of the cDNA in Korla fragrant pear were highly homologous with those of MYB transcription factors in other plant species, suggesting that the sequence is a MYB transcription factor gene. The abundance of kfpMYB mRNA varied significantly between the second and fourth flowers on the branch. Furthermore, kfpMYB expression changed significantly during anthesis and was significantly higher in Jinfeng pear (persistent calyx) and Korla fragrant pear than in Yali pear (deciduous calyx). Expression of kfpMYB was significantly reduced by naphthalene (NAA), abscisic acid (ABA), PBO, and paclobutrazol (PP333). Uniconazole, ethylene (ETH), and gibberellic acid (GA3) had no signicant effect on kfpMYB expression. In conclusion, the expression of kfpMYB appears to be correlated with calyx persistence in Korla fragrant pear.

Organic semiconductor distributed feedback (DFB) laser as excitation source in Raman spectroscopy.

As an application of organic semiconductor distributed feedback (DFB) lasers we demonstrate their use as excitation sources in Raman spectroscopy. We employed an efficient small molecule blend, a high quality resonator and a novel encapsulation method resulting in an improved laser output power, a reduced laser line width and an enhanced power stability. Based on theses advances, Raman spectroscopy on selected substances was enabled. Raman spectra of sulfur and cadmium sulfide are presented and compared with the ones excited by a helium-neon laser. We also fabricated a spectrally tunable organic semiconductor DFB laser to optimize the Raman signals for a given optical filter configuration.

Composite Observer-Based Optimal Attitude-Tracking Control With Reinforcement Learning for Hypersonic Vehicles.

This article proposes an observer-based reinforcement learning (RL) control approach to address the optimal attitude-tracking problem and application for hypersonic vehicles in the reentry phase. Due to the unknown uncertainty and nonlinearity caused by parameter perturbation and external disturbance, accurate model information of hypersonic vehicles in the reentry phase is generally unavailable. For this reason, a novel synchronous estimation is proposed to construct a composite observer for hypersonic vehicles, which consists of a neural-network (NN)-based Luenberger-type observer and a synchronous disturbance observer. This solves the identification problem of nonlinear dynamics in the reference control and realizes the estimation of the system state when unknown nonlinear dynamics and unknown disturbance exist at the same time. By synthesizing the information from the composite observer, an RL tracking controller is developed to solve the optimal attitude-tracking control problem. To improve the convergence performance of critic network weights, concurrent learning is employed to replace the traditional persistent excitation condition with a historical experience replay manner. In addition, this article proves that the weight estimation error is bounded when the learning rate satisfies the given sufficient condition. Finally, the numerical simulation demonstrates the effectiveness and superiority of the proposed approaches to attitude-tracking control systems for hypersonic vehicles.

Robust Packetized MPC for Networked Systems Subject to Packet Dropouts and Input Saturation With Quantized Feedback.

This article develops a robust packetized predictive control framework to deal with the quantized-feedback control problem of networked systems subject to Markovian packet dropouts and input saturation. In the proposed framework, the Markov chain model of packet dropout is established from the link of the controller to the actuator. To deal with the quantized measurements, a robust packetized predictive control method is presented with a quantized-feedback law. The problem of unreliable transmission is addressed by proposing a packet dropout compensation strategy with a forgetting factor. An augmented Markovian jump system model is established to take the packet dropouts into account. The synthesis of packetized predictive control is then developed by minimizing a worst case cost function with respect to the model uncertainties. The recursive feasibility of the proposed controller design problem and the mean-square stability of the closed-loop systems are proved, respectively. The proposed packetized predictive control method is demonstrated by simulating a four-tank process system.

Sparse Actuator Attack Detection and Identification: A Data-Driven Approach.

This article aims to investigate the data-driven attack detection and identification problem for cyber-physical systems under sparse actuator attacks, by developing tools from subspace identification and compressive sensing theories. First, two sparse actuator attack models (additive and multiplicative) are formulated and the definitions of I/O sequence and data models are presented. Then, the attack detector is designed by identifying the stable kernel representation of cyber-physical systems, followed by the security analysis of data-driven attack detection. Moreover, two sparse recovery-based attack identification policies are proposed, with respect to sparse additive and multiplicative actuator attack models. These attack identification policies are realized by the convex optimization methods. Furthermore, the identifiability conditions of the presented identification algorithms are analyzed to evaluate the vulnerability of cyber-physical systems. Finally, the proposed methods are verified by the simulations on a flight vehicle system.

Identification and Characterization of Novel ACE Inhibitory and Antioxidant Peptides from Sardina pilchardus Hydrolysate.

Sardina pilchardus is a valuable source of bioactive peptides with potential applications in functional foods. In this study, we investigated the angiotensin-converting enzyme (ACE) inhibitory activity of Sardina pilchardus protein hydrolysate (SPH) produced using dispase and alkaline protease. Our results showed that the low molecular mass fractions (<3 kDa) obtained through ultrafiltration exhibited more effective ACE inhibition, as indicated by screening with ACE inhibitory activity. We further identified the low molecular mass fractions (<3 kDa) using an LC-MS/MS rapid screening strategy. A total of 37 peptides with potential ACE inhibitory activity were identified based on high biological activity scores, non-toxicity, good solubility, and novelty. Molecular docking was used to screen for peptides with ACE inhibitory activity, resulting in the identification of 11 peptides with higher -CDOCKER ENERGY and -CDOCKER INTERACTION ENERGY scores than lisinopril. The sequences FIGR, FILR, FQRL, FRAL, KFL, and KLF were obtained by synthesizing and validating these 11 peptides in vitro, all of which had ACE inhibitory activity, as well as zinc-chelating capacity. All six peptides were found to bind to the three active pockets (S1, S2, and S1') of ACE during molecular docking, indicating that their inhibition patterns were competitive. Further analysis of the structural characteristics of these peptides indicated that all six peptides contain phenylalanine, which suggests that they may possess antioxidant activities. After experimental verification, it was found that all six of these peptides have antioxidant activities, and we also found that the SPH and ultrafiltration fractions of SPH had antioxidant activities. These findings suggest that Sardina pilchardus may be a potential source of natural antioxidants and ACE inhibitors for the development of functional foods, and using LC-MS/MS in combination with an online database and molecular docking represents a promising, effective, and accurate approach for the discovery of novel ACE inhibitory peptides.

Effects of Probiotics Supplementation on the Intestinal Metabolites, Muscle Fiber Properties, and Meat Quality of Sunit Lamb.

The development of animal husbandry is closely related to the meat quality of small ruminants. Intestinal metabolites and the muscle fiber types of lambs are important factors that affect their meat quality, but few studies have examined the regulation of the "intestinal muscle axis" by probiotics. In this study, 12 Sunit lambs were divided into a control group (C) and a probiotics group (P). The gene expressions of the myosin heavy chain, metabolic enzyme activity, and short-chain fatty acids in the intestines were analyzed using gas chromatography-mass spectrometry (GC-MS) and quantitative real-time PCR. The results showed that levels of propionic acid and butyric acid in the intestines of group P were significantly higher than in group C (p < 0.05). In addition, probiotics increased the number and area ratio of type I muscle fibers. They also increased the mRNA expression of MyHC IIA and the activity of malate dehydrogenase (MDH) and succinate dehydrogenase (SDH). Propionic acid was negatively correlated with the number ratio of type IIB muscle fibers. Butyric acid was found to be significantly positively correlated with the number ratio of type IIA muscle fibers. Cooking loss, pH24h, and shear force decreased significantly in group P. In conclusion, intestinal metabolites (SCFAs) altered the activity of oxidative-myofibril-metabolizing enzymes and the expression of myosin heavy-chain type IIA, reduced the meat shear values, and improved meat tenderness. This study provides a new basis for improving the production and meat quality of small ruminants.

Distributed Observer Design for Linear Systems to Achieve Omniscience Asymptotically Under Jointly Connected Switching Networks.

The distributed observer problem is motivated by the case where the output information of the system is decentralized in different subsystems. In this scene, all the subsystems form an observer network, and each of them has access to only a part of output information and the information exchanged via the given communication networks. Due to the limitation of communication conditions among subsystems, the communication network is often time varying and disconnected. However, the existing research about the aforementioned scene is still not enough to solve this problem. To this end, this article is concerned with the challenge of the distributed observer design for linear systems under time-variant disconnected communication networks. The design method is successfully established by fixing both completely decentralized output information and incompletely decentralized output information into account. Our work overcomes the limitation of the existing results that the distributed observer can only reconstruct the full states of the underlying systems by means of fast switching. In the case of completely decentralized output information, a group of sufficient conditions is put forward for the system matrix, and it is proved that the asymptotical omniscience of the distributed observer could be achieved as long as anyone of the developed conditions is satisfied. Furthermore, unlike similar problems in multiagent systems, the systems that can meet the proposed conditions are not only stable and marginally stable systems but also some unstable systems. As for the case where the output information is not completely decentralized, the results show with the observable decomposition and states reorganization technology that the distributed observer could achieve omniscience asymptotically without any constraints on the system matrix. The validity of the proposed design method is emphasized in two numerical simulations.

Adaptive-Critic Design for Decentralized Event-Triggered Control of Constrained Nonlinear Interconnected Systems Within an Identifier-Critic Framework.

This article studies the decentralized event-triggered control problem for a class of constrained nonlinear interconnected systems. By assigning a specific cost function for each constrained auxiliary subsystem, the original control problem is equivalently transformed into finding a series of optimal control policies updating in an aperiodic manner, and these optimal event-triggered control laws together constitute the desired decentralized controller. It is strictly proven that the system under consideration is stable in the sense of uniformly ultimate boundedness provided by the solutions of event-triggered Hamilton-Jacobi-Bellman equations. Different from the traditional adaptive critic design methods, we present an identifier-critic network architecture to relax the restrictions posed on the system dynamics, and the actor network commonly used to approximate the optimal control law is circumvented. The weights in the critic network are tuned on the basis of the gradient descent approach as well as the historical data, such that the persistence of excitation condition is no longer needed. The validity of our control scheme is demonstrated through a simulation example.

Impact of dietary Lactobacillus supplementation on intramuscular fat deposition and meat quality of Sunit sheep.

To investigate the impacts of dietary Lactobacillus supplementation on meat quality such as edible quality and nutritional value of Sunit sheep, a 90-day feeding experiment (Lactobacillus dietary group, R group; non-Lactobacillus dietary group, C group) using twelve 3-month-old Sunit sheep was conducted. The deposition of intramuscular fat (IMF) was increased (p < .05) while the share force and cooking loss were decreased (p < .05) in the R group compared with the C group. The proportions of seven kinds of fatty acids (FAs) have changed significantly (p < .05), especially with higher functional FAs and lower trans-FA in the R group. Metabonomics analysis showed that the metabolites and pathway-related lipid syntheses, such as carnitine cycle, tricarboxylic acid cycle, and glycerophosphocholine metabolic pathway, have significantly changed in the R group. The Lactobacillus dietary supplements impacted the variation of IMF deposition and FAs composition by altering the lipid metabolism pathways of Sunit sheep and then changed the edible quality and nutritional value. PRACTICAL APPLICATIONS: It is well known that the intramuscular fat (IMF) and fatty acids composition in livestock is positively correlated with various aspects of meat quality such as edible quality and nutritional value, which are related to consumer preference. The present study analyzed the effects of Lactobacillus supplement on the intramuscular fat deposition and meat quality of Sunit sheep, which resulted in the increase of IMF, and the differences of fatty acids composition, especially the functional fatty acids. It was explored the mechanism of Lactobacillus affect the variation of lipid metabolism pathways and key metabolites in sheep, which suggested that altering the feeding regimen could improve the meat quality of agri-animals.

Effect of dietary probiotics supplementation on meat quality, volatile flavor compounds, muscle fiber characteristics, and antioxidant capacity in lambs.

This study investigated the effects of probiotics on growth performance, meat quality, muscle fiber characteristics, volatile compounds, and antioxidant capacity in lambs. A total of 24 Sunit lambs were randomly allocated into two groups, each consisting of three replicates of four lambs. Throughout the experiment period, the lambs were fed with based diet (CON) and 10 g probiotics/d supplemented diet (PRO). Compared with the CON group, the number of lactic acid bacteria in fecal samples of PRO group was significantly increased (p < .05) and the coliforms were significantly decreased (p < .05). Dietary probiotics supplementation decreased pH24h, L*, and shear force (p < .05). The muscle fibers were switched from type IIB to type I, with a decrease in the mean cross-sectional area (CSA) (p < .05) of longissimus thoracis (LT) muscle. Also, probiotics altered the composition of meat volatile flavor compounds, such as nonanal, undecanal, 1-pentanol, 1-hexanol, and 2,3-octanedione. In addition, probiotics increased the total antioxidative capacity (T-AOC) and catalase (CAT) activity of LT muscle, while it decreased superoxide dismutase (SOD) activity (p < .05). Overall, these results indicated that probiotics could be used as an effective feed additive by improving meat tenderness and flavor.

Impact of Feeding Probiotics on Blood Parameters, Tail Fat Metabolites, and Volatile Flavor Components of Sunit Sheep.

Sheep crude tail fat has unique nutritional values and is used as a raw material for high-quality natural oil. The purpose of this study was to investigate the effects of probiotics on the metabolites and flavor of sheep crude tail fat. In this study, 12 Sunit sheep were randomly divided into an experimental group (LTF, basal feed + Lactiplantibacillusplantarum powder) and a control group (CTF, basal feed). The results of sheep crude tail fat analysis showed that blood lipid parameters were significantly lower and the expression of fatty acid synthase and stearoyl-CoA desaturase genes higher in the LTF group than in the CTF group (p < 0.05). Metabolomic analysis via liquid chromatography−mass spectrometry showed that the contents of metabolites such as eicosapentaenoic acid, 16-hydroxypalmitic acid, and L-citrulline were higher in the LTF group (p < 0.01). Gas chromatography−mass spectrometry detection of volatile flavor compounds in the tail fat showed that nonanal, decanal, and 1-hexanol were more abundant in the LTF group (p < 0.05). Therefore, Lactiplantibacillus plantarum feeding affected blood lipid parameters, expression of lipid metabolism-related genes, tail fat metabolites, and volatile flavor compounds in Sunit sheep. In this study, probiotics feeding was demonstrated to support high-value sheep crude tail fat production.

Effects of energy supplements on the differentiation of skeletal muscle satellite cells.

To investigate the effects of the activator of AMPK and high glucose on the differentiation of mouse SMSCs, primary SMSCs were isolated from mouse extensor digitorum longus muscle and grown to near confluence (80%). Postconfluent cells were cultured in a growth medium with different inductors: AICAR, glucose, and AICAR mixed with glucose. The specific protein expressions of SMSCs, myoblasts, adipocytes, and brown adipocytes were analyzed on days 0, 3, 5, 7, and 10. The results showed treatment with AICAR in SMSCs markedly activated AMPK phosphorylation (p < .05) and increased protein expression of Pax7 and MyoD (p < .05), high concentrations of intracellular glucose upregulated UCP-1 protein expression and enhanced lipid accumulation (p < .05), the cowork of AICAR and glucose affected a decrease on MyoD, PPARg, and UCP-1 expression (p < .05) and an increase on Pax7. The present study indicated that the certain energy supplements influence the direction of SMSC differentiation which may contribution on the structure of muscle and meat quality, sequentially.

Assistive Navigation Using Deep Reinforcement Learning Guiding Robot With UWB/Voice Beacons and Semantic Feedbacks for Blind and Visually Impaired People.

Facilitating navigation in pedestrian environments is critical for enabling people who are blind and visually impaired (BVI) to achieve independent mobility. A deep reinforcement learning (DRL)-based assistive guiding robot with ultrawide-bandwidth (UWB) beacons that can navigate through routes with designated waypoints was designed in this study. Typically, a simultaneous localization and mapping (SLAM) framework is used to estimate the robot pose and navigational goal; however, SLAM frameworks are vulnerable in certain dynamic environments. The proposed navigation method is a learning approach based on state-of-the-art DRL and can effectively avoid obstacles. When used with UWB beacons, the proposed strategy is suitable for environments with dynamic pedestrians. We also designed a handle device with an audio interface that enables BVI users to interact with the guiding robot through intuitive feedback. The UWB beacons were installed with an audio interface to obtain environmental information. The on-handle and on-beacon verbal feedback provides points of interests and turn-by-turn information to BVI users. BVI users were recruited in this study to conduct navigation tasks in different scenarios. A route was designed in a simulated ward to represent daily activities. In real-world situations, SLAM-based state estimation might be affected by dynamic obstacles, and the visual-based trail may suffer from occlusions from pedestrians or other obstacles. The proposed system successfully navigated through environments with dynamic pedestrians, in which systems based on existing SLAM algorithms have failed.

Contributions of enzymes and gut microbes to biotransformation of perfluorooctane sulfonamide in earthworms (Eisenia fetida).

Perfluorooctane sulfonamide (FOSA) is known as a key intermediate of perfluorooctane sulfonic acid (PFOS) precursors, which can be frequently detected in the environment and biota. FOSA could be bioaccumulated in earthworms from soil, but the contributions of enzymes and gut microbes involved in the biotransformation of FOSA in earthworms have not been identified. Therefore, the effects of enzyme inhibitors and intestinal microflora on biotransformation of FOSA in earthworms were investigated in the present study. FOSA was biotransformed to form PFOS by earthworms obtained from in vivo and in vitro tests. The addition of FOSA had significantly positive effects on cytolchrome P450 (CYP450) and glutathione-s-transferase (GST) activities, suggesting CYP450 and GST are likely involved in the enzymatic transformation. In addition, both 1-Aminobenzotriazole (ABT) and ezatiostat hydrochloride (TLK199), which were selected to inhibit the CYP and GST enzymes, respectively, demonstrated inhibition effects on biotransformation of FOSA in earthworms with a dose-dependent relationship. However, the concentrations of FOSA weren't changed by the bacteria isolated from worm gut, suggesting that gut bacteria did not contribute to FOSA biotransformation in earthworms. The results of this study confirm that the transformation of FOSA in earthworms is mediated mainly by enzymes rather than by gut microbes.

Effect of feeding regimen on meat quality, MyHC isoforms, AMPK, and PGC-1α genes expression in the biceps femoris muscle of Mongolia sheep.

The effects of two feeding regimens on meat quality, myosin heavy chain (MyHC) types, and key factors regulating muscle fiber type (AMP-activated protein kinase [AMPK] and peroxisome proliferator-activated receptor-coactivator-1α [PGC-1α]) in the biceps femoris muscle of Mongolia sheep were investigated. A total of 20 Mongolia sheep were weaning for 90 days and divided into two groups (pasture group (P) and confinement group (C)) at 10.36 ± 0.35 kg of weaning weight. After weaning, sheep were pasture fed or confinement fed for 9 months. The results showed that live weights, carcass weight, intramuscular fat (IMF), and Warner-Bratzler shear force (WBSF) in P group were significantly lower (p < .05) than that in C group. Compared with P group, color evaluations with respect to L* and b* values were significantly higher (p < .05) in C group. Expression of the MyHC I gene in the P group was significantly higher, while MyHC IIa and MyHC IIb genes expression was significantly lower (p < .05) than that in C group. Also, AMPK activity and expression of AMPKα2 and PGC-1α genes were significantly higher (p < .05) in P group compared with C group. The present study indicated that muscle fiber composition was one of the key differences leading to the differences of meat quality in different feeding regimens. AMPK, particularly AMPKα2, and PGC-1α were considered to be two key factors regulating muscle fiber types in Mongolia sheep. The results support that AMPK activity and the expression of AMPKα2 and PGC-1α genes may affect the composition of muscle fibers; thus, AMPK activity and the expression of AMPKα2 and PGC-1α genes had an effect on meat quality by changed composition of muscle fibers.