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A six-week feeding trial was conducted to investigate the effects of dietary starch levels on growth performance, glucose and lipid metabolism and insulin signaling pathway of juvenile Scylla paramamosain. Three isonitrogenous (41.51% ± 0.31%) and isolipidic (8.68% ± 0.53%) experimental diets were formulated to contain 10%, 20% and 30% starch levels, respectively. A total 96 crabs were divided into 3 treatment groups. There were 4 replicates per treatment group and 8 crabs per replicate (initial weight 5.12 ± 0.05 g). The crabs fed the diet with 20% starch showed the best growth performance, with higher weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER), and feed efficiency (FE) compared to the other diets. Increasing starch levels in the diet resulted in higher levels of glycogen and lipid in the muscles and hepatopancreas. The levels of glucose (GLU), triglyceride (TG), and free fatty acid (FFA) displayed a significant increase in both hemolymph and hepatopancreas with the escalating dietary starch concentrations. In contrast, as the dietary starch levels increased, the concentrations of crustacean hyperglycemic hormone (CHH) and insulin-like peptides (ILPs) in hemolymph and hepatopancreas demonstrated a notable decline. The glycolysis and pentose phosphorylation pathways were significantly promoted, while the gluconeogenic pathway was significantly inhibited, with dietary starch levels increasing from 10% to 30%. Additionally, increasing dietary starch levels led to a significant down-regulation of genes related to the lipid synthesis, lipolysis and insulin signaling pathway. Histological results showed that hepatopancreas fat accumulation increased with the increase of dietary starch level. Overall, the findings of this study suggest that adding 20% starch to the diet can promote growth and improve nutrient utilization. In addition, the level of dietary starch had significant effects on the glucose and lipid metabolism and insulin signaling pathway of mud crabs, thus affecting the deposition of lipid reserves in hepatopancreas.

It is fundamental to obtain accurate land surface temperature (LST) to study surface energy process. Infrared thermal imagers are commonly used for deriving LST on the basis of radiance measurements. However, when deriving LST from brightness temperature of a blackbody in thermal imagers, thermal imagers only allow setting a fixed land surface emissivity (LSE). This causes uncertainty in retrieving thermal infrared (TIR) temperature from heterogeneous surfaces with varied LSE, such as those covered in vegetation. Corrections can be made using the Normalized Vegetation Index (NDVI). However, commercial thermal imagers provide only red (R), green (G), and blue (B) bands without a near infrared band so NDVI cannot be calculated on the same instrument and is commonly not available. We propose an alternative method to estimate LSE using RGB-based vegetation index. Thereafter the estimated LSE was used to correct the TIR temperature derived from the fixed LSE. An experiment was conducted to validate the proposed correcting method. The results show that 1) the corrected LST values were closer to the ground truth, with a mean absolute error (MAE) of 0.41 ± 0.34 °C, whereas the MAE was 0.75 ± 0.56 °C for the uncorrected LST; 2) the more heterogeneous the surface, the greater the difference between the corrected and uncorrected LST values, indicating the necessity of LST correction when applying thermal imagers over heterogeneous surface.

Cadmium (Cd) is a major pollutant in water, and long-term Cd exposure seriously threatens aquatic organisms. This study evaluated the effects of dietary Cd on growth performance, tissue Cd accumulation, oxidative stress, endoplasmic reticulum (ER) stress, inflammation, apoptosis, and anti-stress response in juvenile black seabream (Acanthopagrus schlegelii). Six experimental diets containing different concentration of Cd were formulated: 0.02 (Control, Cd0.02), 1.60 (Cd1.60), 24.29 (Cd24.29), 49.04 (Cd49.04), 117.26 (Cd 117.26), and 289.65 (Cd289.65) mg/kg. A feeding experiment was performed on 540 juvenile black seabreams (initial weight, 1.42 ± 0.01 g), which were conducted for ten weeks. The findings revealed that Cd in the diet lowered weight gain (WG) and specific growth rate (SGR), but had no effect on survival. Dramatically positive linear trends were found between increasing dietary Cd contents and tissue Cd accumulation, including liver, kidney, and muscle. Dietary Cd exposure increased malondialdehyde (MDA) production in both serum and liver, hence, caused oxidative stress. The endoplasmic reticulum (ER) stress-related genes, including grp78, atf6, and xbp1, were markedly increased with increased dietary Cd levels, showing ER stress was triggered. Likewise, transcriptional expression levels of genes related to anti-stress response mt2, hsp70, and hsp90 were linearly up-regulated with increased dietary Cd contents. Regarding apoptosis, the transcriptional expression levels of pro-apoptosis genes caspase7, caspase9, and bax and anti-apoptosis gene bcl-2 were all significantly promoted with the increasing dietary Cd levels. Similar patterns were found for gene expression levels linked to inflammatory response, as the dietary Cd contents increased, nuclear transcription factor nf-κb, pro-inflammatory cytokines tnfα and il-1β, and anti-inflammatory il-10 and tgfβ were dramatically elevated. In conclusion, dietary Cd supplementation suppressed growth performance, increased Cd deposition in tissues, induced oxidative stress, ER stress, apoptosis, and inflammation. In contrast, black seabream juveniles also showed substantial tolerance for dietary Cd exposure by promoting anti-stress ability.

Three isonitrogenous diets (41% crude protein) with 4.87%, 10.75% and 16.10% lipid were designed to evaluate the effects of dietary lipid levels growth, antioxidant capacity, expression levels of genes related to lipid and glucose metabolism of juvenile Scylla paramamosain. Each diet was fed to four replicates of 32 crabs with initial weight 5.10 ± 0.05 g for 6 weeks. The results indicated that crabs fed diet with 10.75% lipid exhibited significantly higher percent weight gain (PWG) and specific growth rate (SGR) than those fed diet with 4.87% lipid (P

As a functional fatty acid, Arachidonic acid (ARA) plays an important role in immunity due to its metabolites in mammals, which have been extensively studied in mammals. However, studies on the function of metabolites produced by dietary ARA in aquatic animals are not comprehensive and in-depth. Hence, an eight-week feeding trial was conducted to evaluated the regulatory effects of dietary ARA and its metabolites-eicosanoids on inflammation, oxidative stress and apoptosis in the liver of Acanthopagrus schlegelii with an initial weight of 0.99 ± 0.10 g. Six isonitrogenous and isolipidic (41% protein, 14% lipid) diets were formulated with gradient levels of ARA: 0% (ARA0.10), 0.5% (ARA0.59), 1.0% (ARA1.04), 1.5% (ARA1.42), 2.0% (ARA1.94), 2.5% (ARA2.42), respectively, and palmitic acid was used to regulate lipid levels. Results showed that the key enzyme contents of ARA metabolic pathway such as phospholipase A2 (PLA2), cyclooxygenase-2 (COX-2), lipoxygenase (LOX) cytochrome P450 (CYP450), prostaglandin E2 (PGE2), leukotriene C4 (LTC4) and 20-hydroxyeicosatetraenoic acid (20-HETE) in the liver were increased with dietary ARA levels increased. High levels of dietary ARA (1.94% and 2.42%) activated the gene expression levels of nuclear factor kappa B (nf-κb), which were confirmed by the results of immunofluorescence assay. Likewise, the expression levels of pro-inflammatory cytokines (tnf-α and il-1β) were up-regulated by ARA1.94 and ARA2.42 groups. Fish fed with excess ARA level has significantly low antioxidant capacity by decreasing the activity of related antioxidant parameters and down-regulating the expression level of related genes. The pro-apoptotic related genes (bax and caspase 7/9) were markedly up-regulated as dietary ARA levels increased from 1.04% to 2.42%. Collectively, excess dietary ARA levels (1.92% and 2.42%) produced excess eicosanoids, triggering inflammation via activating NF-κB expression and promoting its nuclear translocation, resulting in oxidative stress by reducing antioxidant parameters (SOD, GSH and GPX), inducing cell apoptosis through up-regulating pro-apoptotic gene expression levels.

Vegetable oil (VO) is increasingly replacing fish oil (FO) in the commercial diet of crustaceans, partly due to a global shortage of FO. But little is known about how different amounts of substitution affect the health and metabolism of crustaceans. A six-week feeding trial was conducted to evaluated the effects of different replacement levels of FO with linseed oil (LO) on growth performance, antioxidant and digestive capacity and fatty acid metabolism in swimming crab, Portunus trituberculatus. Five isonitrogenous and isolipidic diets (480 g kg−1 protein and 120 g kg−1 lipid) were formulated to contain graded levels of LO, and FO was replaced with LO at 0%, 25%, 50%, 75% and 100%, respectively. The results showed that 50% of FO could be replaced by LO without affecting the growth performance and feed utilization for juvenile swimming crab. In hemolymph, 100% dietary replacement of FO with LO, the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) exhibited significantly higher than those fed the other diets, the concentrations of triacylglycerol (TAG), total cholesterol (T-CHO) and high-density lipoprotein cholesterol (HDL-C) significantly increased with increase of dietary replacement of FO with LO, which may lead to hyperlipidemia in swimming crabs. The number of R cells and their lipid droplets in hepatopancreas gradually increased with increase of replacement of FO with LO, the results confirmed the occurrence of lipid accumulation in the hepatopancreas. The activities of glutathione (GSH), and glutathione peroxidase (GPX) in hepatopancreas significantly decreased with increase of replacement of FO with LO, and crabs fed diet with 50% replacement of FO with LO had higher activities of trypsin and lipase (LPS) than those fed the other diets. Long-chain polyunsaturated fatty acids (LC-PUFA), n-3/n-6 PUFA in hepatopancreas and muscle significantly decreased with the increase of substitution level of FO with LO. Moreover, the expression of genes related to LC-PUFA synthesis as well as fatty acid β-oxidation, such as elongase 4 (elovl4), hepatocyte nuclear factor 4-α (hnf4α), retinoid X receptor (rxr), carnitine palmitoyltransferase 2 (cpt2) and acyl-CoA oxidase (acox2), were down-regulated with increase of dietary replacement of FO with LO. In conclusion, it is suggested that the optimal substitution ratio of LO for FO should be less than 50% in the diet of Portunus trituberculatus.

Summary: Background: Determining the origin of bone metastatic cancer (OBMC) is of great significance to clinical therapeutics. It is challenging for pathologists to determine the OBMC with limited clinical information and bone biopsy. Methods: We designed a regional multiple-instance learning algorithm to predict the OBMC based on hematoxylin-eosin (H&E) staining slides alone. We collected 1041 cases from eight different hospitals and labeled 26,431 regions of interest to train the model. The performance of the model was assessed by ten-fold cross validation and external validation. Under the guidance of top3 predictions, we conducted an IHC test on 175 cases of unknown origins to compare the consistency of the results predicted by the model and indicated by the IHC markers. We also applied the model to identify whether there was tumor or not in a region, as well as distinguishing squamous cell carcinoma, adenocarcinoma, and neuroendocrine tumor. Findings: In the within-cohort, our model achieved a top1-accuracy of 91.35% and a top3-accuracy of 97.75%. In the external cohort, our model displayed a good generalizability with a top3-accuracy of 97.44%. The top1 consistency between the results of the model and the immunohistochemistry markers was 83.90% and the top3 consistency was 94.33%. The model obtained an accuracy of 98.98% to identify whether there was tumor or not and an accuracy of 93.85% to differentiate three types of cancers. Interpretation: Our model demonstrated good performance to predict the OBMC from routine histology and had great potential for assisting pathologists with determining the OBMC accurately. Funding: National Science Foundation of China (61875102 and 61975089), Natural Science Foundation of Guangdong province (2021A15-15012379 and 2022A1515 012550), Science and Technology Research Program of Shenzhen City (JCYJ20200109110606054 and WDZC20200821141349001), and Tsinghua University Spring Breeze Fund (2020Z99CFZ023).

An eight-week feeding trial was conducted to investigate the effects of dietary lipid sources on growth performance, fatty acids composition in tissue and expression of genes related to lipid metabolism in juvenile largemouth bass (Micropterus salmoides). Four experimental diets were formulated to contain 6% coconut oil (CO), rapeseed oil (RO), linseed oil (LO) and fish oil (FO), respectively. Each diet was fed to triplicate groups of juvenile for 8 weeks. The results indicated that final body weight (FBW), percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), survival, hepatopancreas index (HSI), viscerosomatic index (VSI) and intraperitoneal fat ratio (IPF) were not significantly influenced by dietary different lipid sources (P＞0.05). Moreover, proximate composition in whole body, dorsal muscle and liver were also not significantly affected by dietary different lipid sources (P ＞0.05). Fish fed with FO diet was significantly higher MDA concentration in hepatic and serum than those fed with CO, RO and LO diets (P

Helicoverpa armigera (cotton bollworm) is one of the most destructive pests worldwide. Due to resistance to Bacillus thuringiensis and conventional insecticides, an effective management strategy to control this pest is urgently needed. Spinosad, a natural pesticide, is considered an alternative; however, the mechanism underlying the developmental effects of sublethal spinosad exposure remains elusive. In this study, the mechanism was examined using an insect model of H. armigera. Results confirmed that exposure to sublethal spinosad led to reduced larval wet weight, delayed larval developmental period, caused difficulty in molting, and deformed pupae. Further investigation demonstrated that exposure to sublethal spinosad caused a significant decrease in 20E titer and increase in JH titer, thereby leading to the discordance between 20E and JH titers, and consequently alteration in the expression levels of HR3 and Kr-h1. These results suggested that sublethal spinosad caused hormonal disorders in larvae, which directly affect insect development. Our study serves as a reference and basis for the toxicity evaluation of spinosad on molting and pupation in insect metamorphosis, which may contribute to identifying targets for effective control of cotton bollworm.

Above-ground biomass (AGB) is an essential indicator for assessing ecosystem health and carbon storage in desert shrub-related research. Above-ground volume (AGV) of vegetation is a crucial parameter to estimate the AGB. In unmanned aerial vehicle (UAV) remote sensing, the AGV and AGB are mainly estimated by vegetation feature metrics (for example, spectral indices, textural, and structural metrics). However, there is limited study on the AGV and AGB estimation in desert shrub communities by using UAV, and it is difficult to determine the contribution of these metrics to AGV models under eliminating the influence of background factors. Taking a typical desert shrub area in Inner Mongolia, China as an example, this study develops an improved approach to extracted three types of feature metrics simultaneously using UAV RGB (Red, Green, Blue) images. First, digital orthophoto map (DOM) and digital surface model (DSM) were created through the photogrammetric procedure based on UAV RGB images. Second, the digital terrain model (DTM) for canopy height calculation was generated based on DOM and DSM by object-oriented image binary classification and ground elevation interpolation. Here, we recommended the ENVI Landsat Gap-fill tool to interpolate the ground elevation of vegetation areas. Meanwhile, 21 spectral indices, eight textural metrics, and five structural metrics were extracted. Finally, single-variable and multi-variable commonly used regression models were established based on these metrics and measured AGV with a leave-one-out cross-validation. Results showed that: (1) in the proposed model, the contribution of structural, textural, and spectral metric to shrub AGV models was 86.68, 7.08, and 6.24%, respectively. (2) The horizontal and vertical structural metrics, textural metrics, or spectral indices reflected the one-dimensional change of AGV, which had a saturation effect. (3) The canopy volume, combining the horizontal and vertical characteristics of vegetation canopy, could describe the overall change of AGV and played the most essential role in AGV modelling (R2 = 0.928, relative RMSE = 26.8%). The study findings provide a direct reference in determining suitable vegetation feature metrics for monitoring shrub AGV. The proposed approach for DTM generation and AGV estimation is more efficient, accurate and low-cost than before, and it can be a useful bridge between ground-based investigation and satellite remote sensing.

Since discovery, glucagon biology has remained enigmatic. Studies have shown that glucagon may have physiological effects beyond glucose regulation by binding to its receptor (Gcgr). The potential roles of glucagon and its receptor in the crosstalk between glucose metabolism and immune function of fish remain to be investigated. In the present study, we sequenced and characterized gcgra and gcgrb in grass carp. Phylogenetic analysis showed that they were highly homologous with their counterparts in fish. The gcgra and gcgrb mRNAs were ubiquitously expressed in all the tissues examined. The gcgra mRNA was highly expressed in the liver and gcgrb was mainly expressed in the liver and brain regions of grass carp. Furthermore, the results of oral glucose tolerance test (OGTT) showed that the expression levels of the two receptors were significantly increased at 12 h after treatment. In the hepatocytes, insulin inhibited gcgra and gcgrb mRNA expressions at 3−12 h and 6−12 h, respectively. While glucagon promoted their expressions at 3−12 h and 3 h, respectively. Intraperitoneal injection of lipopolysaccharide (LPS) increased hepatic gcgra mRNA level at 6 h post treatment, and up-regulated gcgrb mRNA abundance in the liver at 24 h. In response to polyinosinic polycytidylic acid [poly (I:C)] stimuli, however, gcgra and gcgrb mRNA levels were decreased. These results suggested that glucagon receptors were affected by bacterial-like and virus-like infection beyond their roles in the glucose metabolism of grass carp.