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The yellowcheek carp (Elopichthys bambusa) is a large and aggressive carnivorous fish. Weaning represents a significant bottleneck in the large-scale aquaculture of yellowcheek carp. To investigate the appropriate timing for weaning and its effects on growth and intestinal health, 15 days post-hatching (dph) weaning group (W15), a 22 dph weaning group (W22), and a 29 dph weaning group (W29) were set up to wean yellowcheek carp at 15 dph, 22 dph, and 29 dph, respectively. We investigated the effects of weaning starting time on growth, survival, and intestinal development. The results showed that the total length, body weight, and survival rate of juvenile yellowcheek carp in the W22 and W29 groups were significantly higher than that in the W15 group at different periods. Additionally, intestinal villus height and muscle thickness were significantly higher in the W22 and W29 groups compared to the W15 group. At 36 dph, the W22 group exhibited the highest specific growth rate, while the W29 group had the highest survival rate. During the weaning period, when the prey's body depth equaled the predator's mouth width, the predator's total length was approximately 1.5 times the prey's total length, described by the relationship TLprey=0.53×TLpredator+3.63. Moreover, the trypsin activity in the fast-growing (FB) group of juvenile yellowcheek carp was significantly higher than that in the slow-growing (FS) group, whereas the activity of amylase, lipase, and alkaline phosphatase were significantly lower. Deferentially expressed genes in the FB and FS groups were significantly enriched in lipid metabolic pathways, including the PPAR signaling pathway, fatty acid metabolism, and fatty acid biosynthesis. qPCR confirmed significant differences in the expression of four lipid metabolism-related genes: FABP7, FAS, CPT1, and GYS2. The results indicated that initiating weaning at 22-29 dph can obtain the best growth and survival outcomes. Additionally, selecting larger individuals, approximately 1.5 times the average length of the population, can prevent cannibalism and improve survival rate during weaning. The growth performance of juvenile yellowcheek carp post-weaning may be linked to differences in intestinal digestive enzyme activities and lipid metabolism ability. This study provides important gui dance for the weaning and post-weaning cultivation of juvenile yellowcheek carp and may inform weaning research for other carnivorous fish species. [ABSTRACT FROM AUTHOR]

Skeletal muscle comprises 30%--80% of fish body weight, which is very important for the health and economic value of fish. Elopichthys bambusa is a high-value economic fish, but the molecular mechanisms underlying muscle development in its juveniles remain unclear. In this study, the muscle development characteristics of juvenile Elopichthys bambusa at different developmental stages and under different domestication strategies were discussed by using histological and transcriptome analysis, complemented by fluorescence quantitative PCR verification. The results showed that the mosaic proliferation of muscle fibers of Elopichthys bambusa larvae began on the 22nd day post-hatching (dph). During the early stage of muscle mosaic proliferation, genes related to MyoGenic regulators (myog and myod), the myostatin gene (mstn), muscle satellite cell marker gene (pax7), and muscle differentiation-related genes (myl3, tnni2, myoz2, tpm1) were actively involved. In addition, the use of artificial compound feed can improve muscle metabolism and promote growth in juvenile Elopichthys bambusa, with the 22 dph group showing higher weaning efficiency and better weaning effect. This study provides a foundation for understanding the characteristics and molecular mechanism of muscle development in Elopichthys bambusa and provide a theoretical reference for large-scale farming practices. [ABSTRACT FROM AUTHOR]

Brown adipose tissue (BAT) represents a valuable target for treating obesity in humans. BAT losses of thermogenic capacity and gains a “white adipose tissue-like (WAT-like)” phenotype (BAT whitening) under thermoneutral environments, which could lead to potential low therapy responsiveness in BAT-based obesity treatments. However, the epigenetic mechanisms of BAT whitening remain largely unknown. In this study, BATs were collected from rabbits at day0 (D0), D15, D85, and 2 years (Y2). RNA-sequencing (RNA-seq) and the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) were performed to investigate transcriptome and chromatin accessibility of BATs at the four whitening stages, respectively. Our data showed that many genes and chromatin accessible regions (refer to as “peaks”) were identified as significantly changed during BAT whitening in rabbits. The BAT-selective genes downregulated while WAT-selective genes upregulated from D0 to Y2, and the de novo lipogenesis-related genes reached the highest expression levels at D85. Both the highly expressed genes and accessible regions in Y2 were significantly enriched in immune response-related signal pathways. Analysis of different relationships between peaks and their nearby genes found an increased proportion of the synchronous changes between chromatin accessibility and gene expression during BAT whitening. The synergistic changes between the chromatin accessibility of promoter and the gene expression were found in the key adipose genes. The upregulated genes which contained increased peaks were significantly enriched in the PI3K-Akt signaling pathway, steroid biosynthesis, TGF-beta signaling pathway, osteoclast differentiation, and dilated cardiomyopathy. Moreover, the footprinting analysis suggested that sequential regulation of potential transcription factors (TFs) mediated the loss of thermogenic phenotype and the gain of a WAT-like phenotype of BAT. In conclusion, our study provided the transcriptional and epigenetic frameworks for understanding BAT whitening in rabbits for the first time and might facilitate potential insights into BAT-based obesity treatments.

Purpose: To address the issues of low localization and mapping accuracy, as well as map ghosting and drift, in indoor degraded environments using light detection and ranging-simultaneous localization and mapping (LiDAR SLAM), a real-time localization and mapping system integrating filtering and graph optimization theory is proposed. By incorporating filtering algorithms, the system effectively reduces localization errors and environmental noise. In addition, leveraging graph optimization theory, it optimizes the poses and positions throughout the SLAM process, further enhancing map accuracy and consistency. The purpose of this study resolves common problems such as map ghosting and drift, thereby achieving more precise real-time localization and mapping results. Design/methodology/approach: The system consists of three main components: point cloud data preprocessing, tightly coupled inertial odometry based on filtering and backend pose graph optimization. First, point cloud data preprocessing uses the random sample consensus algorithm to segment the ground and extract ground model parameters, which are then used to construct ground constraint factors in backend optimization. Second, the frontend tightly coupled inertial odometry uses iterative error-state Kalman filtering, where the LiDAR odometry serves as observations and the inertial measurement unit preintegration results as predictions. By constructing a joint function, filtering fusion yields a more accurate LiDAR-inertial odometry. Finally, the backend incorporates graph optimization theory, introducing loop closure factors, ground constraint factors and odometry factors from frame-to-frame matching as constraints. This forms a factor graph that optimizes the map's poses. The loop closure factor uses an improved scan-text-based loop closure detection algorithm for position recognition, reducing the rate of environmental misidentification. Findings: A SLAM system integrating filtering and graph optimization technique has been proposed, demonstrating improvements of 35.3%, 37.6% and 40.8% in localization and mapping accuracy compared to ALOAM, lightweight and ground optimized lidar odometry and mapping and LiDAR inertial odometry via smoothing and mapping, respectively. The system exhibits enhanced robustness in challenging environments. Originality/value: This study introduces a frontend laser-inertial odometry tightly coupled filtering method and a backend graph optimization method improved by loop closure detection. This approach demonstrates superior robustness in indoor localization and mapping accuracy. [ABSTRACT FROM AUTHOR]

The AlInGaN/GaN heterojunction epitaxy material with high cutoff frequency and saturated power density has become a very popular candidate for millimeter wave applications in next-generation mobile communication. In this study, an advanced voltage-controllable capacitor based on the AlInGaN/GaN-Si (111) epitaxy was proposed by employing a bi-directional series MIS capacitor structure. The capacitor was fabricated by using a pad area of 40 μm × 40 μm, with a 1 μm distance between the positive and negative electrodes. The test results show that the capacitance is turned on with a saturation capacitance density and a maximum leakage current density of 0.30 fF/μm2 of 0.37 pA/μm2, respectively, for the control voltage from −6.5 V to 6 V. In particular, in the proposed design method, the saturation capacitance required for the practical application can be obtained by simply adjusting the capacitance area. The capacitor showcases characteristics of rapid turn-on and turn-off responses coupled with low loss, underscoring its promising prospects for deployment in RF switching applications. [ABSTRACT FROM AUTHOR]

On-chip electrostatic discharge (ESD) protection poses a challenge in the chip fabrication process. In this study, a novel electric fuse (E-fuse) device featuring a simple structure of Ni metal on a SiO2 dielectric for ESD protection was proposed, and the physical mechanism of its operation was investigated in detail. Experimental evaluations, utilizing transmission line pulse (TLP) testing and fusing performance analyses, reveal that the E-fuse, constructed with a Ni metal layer measuring 5 μm in width, 100 μm in length, and 5 nm in thickness, achieved a significant ESD protection voltage of 251 V (VHBM) and demonstrates low-voltage fusing at a bias voltage of 7 V. Compared to traditional ESD protection devices, the E-fuse boasts a smaller size and removability. To assess fusing performance, devices of varying sizes were tested using a fusing lifetime model. This study supports both theoretical and empirical evidence, enabling the adoption of cost-effective, straightforward E-fuse devices for ESD protection. [ABSTRACT FROM AUTHOR]

Due to the current situation of Chinese high-speed motor train unit（EMU） gearbox monopolized by foreign for a long time,and facing the gearbox body cracking problems frequently,the aluminum alloy box body of high-speed EMU is redesigned.By using the three-dimensional modeling software Solid Works,the box body model is created,and the load calculation of the designed box body under two conditions of short circuit and startup is carried out separately.By using the finite element analysis software Workbench,the strength is analyzed,then the simulation test results verify the designed box body won’t appear plastic deformation and crack in both working conditions.According to the analysis results evaluated by TJ / JW064-2015 in startup conditions,to testify that the designed housing meet the requirement of train operation.The research has important reference value to the independent research and development of the high speed Emu gearbox.

The study was to investigate the effect of laying hen's diet on the body weight, serum biochemical indexes, testicular morphology and semen quality of Wannan yellow chicken roosters. Sixty 30-week-old Wannan yellow chicken roosters were randomly divided into two groups (laying hen's diet group and rooster's diet group), roosters were fed a laying hen's diet and a rooster's diet, respectively. The experiment lasted eight weeks. The results showed that the serum calcium content of the roosters fed the laying hen's diet was higher than those fed the rooster's diet in the middle stage of the experiment (P<0.05), and the glucose content was lower than that in the rooster's diet group (P<0.05). At the end of the experiment, the content of serum calcium in the laying hen's diet group was higher than that in the rooster's diet group (P<0.05), and the androgen level was lower than that in the rooster's diet group (P<0.05). The number of leydig cells per unit area, semen volume, semen color and sperm concentration of the rooster's diet group was higher than those of the hen's diet group. The study indicates that the laying hen's diet can increase the serum calcium content and decrease the number of testicular interstitial cells, which can lead to the decrease of serum androgen level and sperm density. [ABSTRACT FROM AUTHOR]

Fuzzy control theory is adopted to study the position control system framework of 3R underactuated robot. Lagrange equation is used to establish the block matrix to solve the trajectory tracking control issue. Later, fuzzy control strategy is used to further plot the control flow chart and establish the simulation model. Based on the comparison between expected value and experiment value, the maximum of related error is 2.22% and the maximum absolute error is 1.43°. The system framework designed in this article may achieve better control over the position of 3D underactuated robot.

The leakage of harmful chemical sources will cause great harm to the environment and human beings; therefore, it is of great social significance to use intelligent mobile robots to achieve accurate and rapid positioning and control of chemical sources. Based on the basic Glowworm Swarm Optimization (GSO), this paper proposes a self-searching mechanism and variable step size optimized GSO for solving the problems of low accuracy and slow convergence speed. This paper studies chemical source positioning problem of multi- robots under no-ventilation environment, and establishes an improved multi-source superposition Gaussian smoke-plume model and a robot model for the simulation experiments. The results show that the accuracy and speed of the positioning of chemical sources by the optimized GSO have been significantly improved.

The evolution of pore structure is very important to the frost resistance of concrete. In order to study the effect of nano-TiO2 on pore structure and frost resistance of concrete, the nano-TiO2 concrete with substitution rates of 0%, 1%, 3%, 5% (mass fraction, the same below) were selected as research object, and the quick freezing test, compressive strength test, nuclear magnetic resonance test and scanning electron microscope test were carried out. The changes of mass, dynamic elastic modulus, compressive strength, pore structure and micro-morphology of nano-TiO2 concrete before and after freeze-thaw cycle were analyzed to evaluate the freeze-thaw damage at - 18 ~ 5 °C and to analyze the improvement mechanism of nano-TiO2 on concrete properties. At the same time, the response models of compressive strength, relative dynamic modulus, free water saturation and crack ratio were established to determine the optimum content of nano-TiO2. The results show that an appropriate content of nano-TiO2 effectively improves the micro-morphology of concrete, increases the proportion of micropores and medium pores of concrete, and reduces the proportion of macropores and cracks, while excessive nano-TiO2 increases the proportion of macropores and cracks in concrete, which is not conducive to the improvement of frost resistance of concrete. When the content of nano-TiO2 is 1%, the frost resistance of concrete is the best. Based on the frost resistance performance index and pore test results, the response model is established, and the optimal content of nano-TiO2 is close to 1%, which is consistent with the test results. [ABSTRACT FROM AUTHOR]