A comparative study to determine the effects of breed and feed restriction on glucose metabolism of chickens.

The glucose metabolism of poultry draws wide attention as they have nearly twice the fasting blood glucose than that of mammals. To define the relationship between glucose metabolism and breed of chicken, the outcomes from different growth rate chickens showed that Arbor Acres (AA) broilers, a well-known fast-growing breed, had a lower fasting blood glucose concentration and glucose clearance rate when compared to Silky chickens, a Chinese traditional medicinal chicken with black skin and a slow growth rate. Moreover, AA broilers had a relatively slow rise in blood glucose in response to oral glucose solution than the Silky chickens on 21 and 42 d (P < 0.05), which is probably attributed to downregulated expression of pancreatic insulin (INS), and upregulated transcription of phosphoenolpyruvate carboxy kinase 1 (PCK1) and glucose transporter 2 (GLUT2) in the liver of AA broilers (P < 0.05). In response to feeding restriction from 7 to 21 d, both the fasting blood glucose and the response speed of AA broilers to oral glucose were increased on d 21 (P < 0.05), and the serum glucose concentrations after 3 weeks compensatory growth were improved by early feed restriction in AA broilers. Feed restriction could also upregulate the mRNA level of pancreatic INS on d 21 and 42, as well as decrease the expressions of PCK1, glucose-6-phosphatase catalytic (G6PC), and GLUT2 in the liver on d 21 (P < 0.05) when compared to the free feeding group. These results revealed that Silky chickens have a stronger capability to regulate glucose homeostasis than AA broilers, and feed restriction could improve the fasting blood glucose and the response to oral glucose of AA broilers.

Real time object detection using LiDAR and camera fusion for autonomous driving.

Autonomous driving has been widely applied in commercial and industrial applications, along with the upgrade of environmental awareness systems. Tasks such as path planning, trajectory tracking, and obstacle avoidance are strongly dependent on the ability to perform real-time object detection and position regression. Among the most commonly used sensors, camera provides dense semantic information but lacks accurate distance information to the target, while LiDAR provides accurate depth information but with sparse resolution. In this paper, a LiDAR-camera-based fusion algorithm is proposed to improve the above-mentioned trade-off problems by constructing a Siamese network for object detection. Raw point clouds are converted to camera planes to obtain a 2D depth image. By designing a cross feature fusion block to connect the depth and RGB processing branches, the feature-layer fusion strategy is applied to integrate multi-modality data. The proposed fusion algorithm is evaluated on the KITTI dataset. Experimental results demonstrate that our algorithm has superior performance and real-time efficiency. Remarkably, it outperforms other state-of-the-art algorithms at the most important moderate level and achieves excellent performance at the easy and hard levels.

Cross-attention-map-based regularization for adversarial domain adaptation.

In unsupervised domain adaptation (UDA), many efforts are taken to pull the source domain and the target domain closer by adversarial training. Most methods focus on aligning distributions or features between the source domain and the target domain. However, little attention is paid to the interaction between finer-grained levels, such as classes or samples of the two domains. In contrast to UDA, another transfer learning task, i.e., few-shot learning (FSL), takes full advantage of the finer-grained-level alignment. Many FSL methods implement the interaction between samples of support sets and query sets, leading to significant improvements. We wonder whether we can get some inspiration from these methods and bring such ideas of FSL to UDA. To this end, we first take a closer look at the differences between FSL and UDA and bridge the gap between them by high-confidence sample selection (HCSS). Then we propose cross-attention map generation module (CAMGM) to interact samples selected by HCSS. Moreover, we propose a simple but efficient method called cross-attention-map-based regularization (CAMR) to regularize the feature maps generated by the feature extractor. Experiments on three challenging datasets demonstrate that CAMR can bring solid improvements when added to the original objective. More specifically, the proposed CAMR can outperform original methods by 1% to 2% in most tasks without bells and whistles.

Dynamic changes of blood glucose, serum biochemical parameters and gene expression in response to exogenous insulin in Arbor Acres broilers and Silky fowls.

Silky chicken is a breed of chickens with black skin and slow growth rate used in Chinese traditional medicine, whereas Arbor Acres broiler is a well-known commercial breed in the poultry industry, it is featured by a large size, rapid-growth rate, high feed-conversion rate and strong adaptability. The difference in their rate of growth may be primarily related to different mechanism for glucose metabolism. Here we compared the insulin sensitivity of the two breeds; we investigated the temporal changes (at 0 min, 120 min and 240 min) of serum insulin and other biochemical parameters and determined the spatio-temporal changes of gene mRNA abundance in response to exogenous insulin (80 µg/kg body weight). The results indicated that: (1) Silky chickens showed stronger blood glucose recovery than broilers in the insulin resistance test. (2) The serum urea level in Silky chickens was twice of broilers; exogenous insulin significantly up-regulated serum uric acid level in Silky fowls in a time-dependent manner and increased serum cholesterol content at 120 min. (3) Two breeds showed distinctly different temporal changed in serum insulin in response to exogenous insulin stimulation. The fasting serum insulin concentration of broilers was three-fold of Silky chickens at the basal state; it decreased significantly after insulin injection and the levels at 120 min and 240 min of broilers were only 23% (P < 0.01) and 14% (P < 0.01) of the basal state, respectively. Whereas the serum insulin content in Silky chickens showed stronger recovery, and the 240 min level was close to the 0 min level. (4) GLUT2, GLUT12, neuropeptide Y and insulin receptor (IR) were predominantly expressed in the liver, pectoralis major, olfactory bulb and pancreas, respectively, where these genes presented stronger insulin sensitivity. In addition, the IR mRNA level was strongly positively with the GLUT12 level. In conclusion, our findings suggested that Silky chickens have a stronger ability to regulate glucose homeostasis than broilers, owing to their higher IR levels in the basal state, stronger serum insulin homeostasis and candidate genes functioning primarily in their predominantly expressed tissue in response to exogenous insulin.

The distinct spatiotemporal distribution and effect of feed restriction on mtDNA copy number in broilers.

Mitochondrial DNA (mtDNA) copy number reflects the abundance of mitochondria in cells and is dependent on the energy requirements of tissues. We hypothesized that the mtDNA copy number in poultry may change with age and tissue, and feed restriction may affect the growth and health of poultry by changing mtDNA content in a tissue-specific pattern. TaqMan real-time PCR was used to quantify mtDNA copy number using three different segments of the mitochondrial genome (D-loop, ATP6, and ND6) relative to the nuclear single-copy preproglucagon gene (GCG). The effect of sex, age, and dietary restriction (quantitative, energy, and protein restriction) on mtDNA copy number variation in the tissues of broilers was investigated. We found that mtDNA copy number varied among tissues (P < 0.01) and presented a distinct change in spatiotemporal pattern. After hatching, the number of mtDNA copies significantly decreased with age in the liver and increased in muscle tissues, including heart, pectoralis, and leg muscles. Newborn broilers (unfed) and embryos (E 11 and E 17) had similar mtDNA contents in muscle tissues. Among 42 d broilers, females had a higher mtDNA copy number than males in the tissues examined. Feed restriction (8-21 d) significantly reduced the body weight but did not significantly change the mtDNA copy number of 21 d broilers. After three weeks of compensatory growth (22-42 d), only the body weight of broilers with a quantitatively restricted diet remained significantly lower than that of broilers in the control group (P < 0.05), while any type of early feed restriction significantly reduced the mtDNA copy number in muscle tissues of 42 d broilers. In summary, the mtDNA copy number of broilers was regulated in a tissue- and age-specific manner. A similar pattern of spatiotemporal change in response to early feed restriction was found in the mtDNA content of muscle tissues, including cardiac and skeletal muscle, whereas liver mtDNA content changed differently with age and dietary restriction. It seems that early restrictions in feed could effectively lower the mtDNA content in muscle cells to reduce the tissue overload in broilers at 42 d to some degree.

The spatio-temporal features of chicken mitochondrial ND2 gene heteroplasmy and the effects of nutrition factors on this gene.

Mitochondrial heterogeneity is the presence of two or more types of mitochondrial (mt)DNA in the same individual/tissue/cell. It is closely related to animal health and disease. ND2 is a protein-coding gene in mtDNA, which participates in mitochondrial respiratory chain and oxidative phosphorylation. In previous studies, we observed that the mt.A5703T and mt.T5727G sites in the ND2 gene were the heteroplasmic variation sites. We used pyrophosphate sequencing technology to examine chicken mt.A5703T and mt.T5727G heteroplasmic sites in the ND2 gene, in different tissues and at different development stages in chickens. We also investigated whether nutritional factors could affect the mt.A5703T and mt.T5727G heteroplasmy. Our results showed that chicken mt.A5703T and mt.T5727G heteroplasmy had clear spatio-temporal specificities, which varied between tissues/development stages. The mtDNA heterogeneity was relatively stable upon nutrition intervention, 30% dietary energy restriction (from 18 to 48 days old) and different types of dietary fats (at 5% concentration, from 1 to 42 days old) did not change the breast muscle heteroplasmy of broilers at the mt.A5703T and mt.T5727G sites. In addition, multiple potential heteroplasmic sites were detected by clone sequencing in the ND2 region, which potentially reflected abundant heteroplasmy in the chicken mitochondrial genome. These results provide an important reference for further research on heteroplasmy in chicken mitochondria.

The permeability enhancing mechanism of menthol on skin lipids: a molecular dynamics simulation study.

The stratum corneum (SC), the outermost layer of skin, represents the primary barrier to molecules penetrating the skin. Menthol is widely used in clinical medicine as a penetration enhancer due to its high efficiency and relative safety. In this study, molecular dynamics simulations have been performed to investigate the effect of menthol molecules on the structural and permeability of both single component and ternary mixed bilayers. The lipid matrix is modeled as pure ceramide (CER2) or as a 2:2:1 mixture of CER2, cholesterol (CHOL), and free fatty acid (FFA). The effect of menthol on the SC bilayer was investigated at various concentrations of menthol. For both models, the area per lipid decreases and the membrane thickness increases with increased menthol concentration, which may be due to the fact that menthol molecules penetrate into the bilayer and aggregate at the bilayer center. As for ternary mixed bilayer at high concentration, the lipids rearranged, and one more layer formed inside the former two leaflets. Our simulation results are consistent with the experimental evidence that high concentrations of menthol fluidize the SC lipids and enhance permeability. The penetration enhancement of menthol may take place through direct interactions with lipids rather than by forming water pores. Graphical abstract The effect of menthol on the structural and permeability of skin lipids was investigated using a molecular dynamics simulation method. Increased menthol concentration makes the area per lipid decrease and the membrane thickness increase. Our results show that the penetration enhancement of menthol may take place through direct interactions with lipids.

Molecular simulation study on concentration effects of rofecoxib with POPC bilayer.

The interactions between rofecoxib and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) bilayer were studied using all-atom molecular dynamics simulation method. Four POPC bilayer systems with different number of rofecoxib molecules were constructed to simulate different drug concentration. The free energy of rofecoxib passing across pure POPC bilayer has two minima (at z ∼1.2nm or 1.6nm). As for the high concentration model, the minimum of the free energy profile slightly shifts to the bilayer center. Moreover, the energy change from bulk water to POPC bilayer increases while the central barrier to cross the hydrophobic core of bilayer slightly decreases, suggesting that increasing drug concentration makes it favorable for rofecoxib to partition into the bilayer and easier to pass across bialyer center. Energy analysis show that the stabilization between the selected rofecoxib and other pre-inserted rofecoxib molecule is mainly due to van der Waals interaction energy. The predicted permeability of rofecoxib in high concentration model slightly weakens as compared with low concentration model.

One-pot syntheses and cell imaging applications of poly(amino acid) coated LaVO4:Eu3+ luminescent nanocrystals.

For successful biological applications of luminescent nanocrystals, surface functionalization is very essential. It is very important to develop the facile synthetic methods to gain access to obtaining water-stable and biocompatible NPs with appropriate functional groups as well as high luminescence efficiency. Herein, a green and facile one-pot hydrothermal strategy was developed for the preparation of poly(amino acid) coated LaVO4:Eu(3+)-PASP luminescent nanocrystals by employing the hydrolysis of polysuccinimide (PSI) to polyaspartic acid (PASP) to provide a general platform for the surface modification. Because of the enriched carboxylic groups in the PASP coating, these as-prepared nanoparticles (NPs) demonstrated good water-stability, biocompatibility, and bioconjugatability. Due to their strong red luminescence and good bioconjugatability, the antibody bioconjugated LaVO4:Eu(3+)-PASP NPs were successfully used as the biomarkers for cancer cell specific luminescence imaging. The results indicate that these NPs have the potential to act as luminescent probes for luminescence assay and in vitro imaging.

DFT and GA studies on the QSAR of 2-aryl-5-nitro-1H-indole derivatives as NorA efflux pump inhibitors.

The structures of 2-aryl-5-nitro-1H-indole derivatives were optimized with PM3 and DFT at b3lyp/6-31 g* level successively. Some structural and electric descriptors were obtained from the single point energy calculation and natural bond orbital analysis at the level of b3lyp/6-31 g*. As efflux pump inhibitors, a QSAR model was built with genetic algrithum (GA) and partial least square (PLS) analyses. The high R(2) and R(2)CV indicates the derived model has a good predictive power which can be used in prediction of activity for new 2-aryl-5-nitro-1H-indole derivatives. This model gives us a revelation that the activity of 2-aryl-5-nitro-1H-indole derivatives as efflux pump inhibitor can be improved by properly increasing the molecular volume and Mulliken atomic charge of C(3)(Q(C3)) or lowering the dipole and Mulliken atomic charge of C(4)(Q(C4)) in 2-aryl and it was found from this article that a QSAR relationship can be built for small samples with large descriptors by compressing the descriptors with GA and analyzing with PLS. With this model, a new compound, 2-(2-Azidomethyl-5-phenoxy-phenyl)-5-nitro-1H-indole was predicted to lower the MIC of berberine to 0.091 microg/mL for inhibiting K2361 of S. aureus with NorA efflux pump protein over expression. Figure: Basic structure of 2-aryl-5-nitro-1H-indoles.