Changes in the milk metabolome of the Giant Panda (Ailuropoda melanoleuca) with time after birth: three phases in early lactation and progressive individual differences

Ursids (bears) in general, and giant pandas in particular, are highly altricial at birth. The components of bear milks and their changes with time may be uniquely adapted to nourish relatively immature neonates, protect them from pathogens, and support the maturation of neonatal digestive physiology. Serial milk samples collected from three giant pandas in early lactation were subjected to untargeted metabolite profiling and multivariate analysis. Changes in milk metabolites with time after birth were analysed by Principal Component Analysis, Hierarchical Cluster Analysis and further supported by Orthogonal Partial Least Square-Discriminant Analysis, revealing three phases of milk maturation: days 1–6 (Phase 1), days 7–20 (Phase 2), and beyond day 20 (Phase 3). While the compositions of Phase 1 milks were essentially indistinguishable among individuals, divergences emerged during the second week of lactation. OPLS regression analysis positioned against the growth rate of one cub tentatively inferred a correlation with changes in the abundance of a trisaccharide, isoglobotriose, previously observed to be a major oligosaccharide in ursid milks. Three artificial milk formulae used to feed giant panda cubs were also analysed, and were found to differ markedly in component content from natural panda milk. These findings have implications for the dependence of the ontogeny of all species of bears, and potentially other members of the Carnivora and beyond, on the complexity and sequential changes in maternal provision of micrometabolites in the immediate period after birth

Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20–30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates

Research on Heat Transfer Inside the Furnace of Large Scale CFB Boilers

Field tests in one unit of 135MWe and two units of 300MWe commercial Circulating Fluidized bed (CFB) boilers (A&B) with different structures were carried out. The influence of operating conditions on the thermal boundary layer, local heat transfer coefficient and peripheral distribution of heat transfer coefficient were studied. It was found that, in the 135MWe and 300MWe-A CFB furnace, the thickness of the thermal boundary layer was almost constant, about 100mm, and independent of the height above the distributor and the boiler load. The local heat transfer coefficient increased with increasing load as well as the coal feeding rate and air volume in both the 135MWe and 300MWe-A CFB boilers. The boiler structure and heating surface layout had a great influence on the distribution of the heat transfer coefficient in the large-scale CFB boilers. In both the 135MWe furnace and the 300MWe-B CFB boilers, the heat transfer coefficient was lower in the center than near the corner due to higher suspension density in the corner. In the 300MWe-B CFB with heating surfaces in the furnace, because of the uneven layout of the heating surface and the mal-distribution of gas-solid flow caused by the asymmetric arrangement of cyclones, heat transfer coefficients tended to be higher in the middle part than at the walls

Coal Ignition Temperature in Oxygen-Enriched CFB Boiler

The oxygen-enriched Circulating fluidized bed (CFB) combustion technology is a new method to reduce CO2 emissions. The coal ignition temperature, Ti F, in an oxygen-enriched CFB boiler is an important parameter for designing the startup burner and for choosing the operating strategy during the startup process. The combustion of five types of coal under four different atmospheres (air, O2 27 %, O2 40%, O2 53%, CO2 as balance gas) was measured in a laboratory scale fluidized bed (FB) with an under-bed preheat system. Using thermocouples and a Gas Analyzer, the changes in bed temperature and the concentration of the different components, such as O2, CO2 and CO, in flue gas were directly measured to determine Ti F. It was found that Ti F decreased with increasing O2 concentration. The differences between the ignition temperatures determined in air and with 27 % O2 were not significant. At lower bed temperatures, for two coal types with higher volatiles, a two stage-ignition for volatiles and char was observed under a high O2 concentration. The time delay between the two stages decreased and finally merged into one with increasing bed temperature. Similar results were obtained in air. The coal with the higher volatile content had a lower ignition temperature in an oxygen-enriched CFB. Comparison of the ignition temperatures obtained by different methods and the feed temperatures in industrial CFB boilers showd that the measured result in a fluidized bed can be used as a reference for oxygen-enriched CFB boilers

Building extraction from high-resolution aerial imagery using a generative adversarial network with spatial and channel attention mechanisms.

Segmentation of high-resolution remote sensing images is an important challenge with wide practical applications. The increasing spatial resolution provides fine details for image segmentation but also incurs segmentation ambiguities. In this paper, we propose a generative adversarial network with spatial and channel attention mechanisms (GAN-SCA) for the robust segmentation of buildings in remote sensing images. The segmentation network (generator) of the proposed framework is composed of the well-known semantic segmentation architecture (U-Net) and the spatial and channel attention mechanisms (SCA). The adoption of SCA enables the segmentation network to selectively enhance more useful features in specific positions and channels and enables improved results closer to the ground truth. The discriminator is an adversarial network with channel attention mechanisms that can properly discriminate the outputs of the generator and the ground truth maps. The segmentation network and adversarial network are trained in an alternating fashion on the Inria aerial image labeling dataset and Massachusetts buildings dataset. Experimental results show that the proposed GAN-SCA achieves a higher score (the overall accuracy and intersection over the union of Inria aerial image labeling dataset are 96.61% and 77.75%, respectively, and the F1-measure of the Massachusetts buildings dataset is 96.36%) and outperforms several state-of-the-art approaches

Investigation on The Hydrodynamic Properties in The External Loop of Circulating Fluidized Bed With a Loop Seal

The pressure balance and mass balance are influenced by the characteristics of different components in the loop of a circulating fluidized bed (CFB). Experiments were conducted in a 4.3 m high cold laboratory CFB test rig with a loop seal. With a fixed bed inventory and superficial gas velocity, the pressure drop of the loop seal decreased with increasing aeration, thus causing an increase in the solid circulation flux (Gs). Correspondingly, the pressure drop in the riser became higher with increasing Gs; the pressure drop of the cyclone had a non-linear relationship with Gs, and the transition point was determined in the experiment. Using the laser fiber and gas tracer method, hydrodynamic characteristics in the standpipe were directly measured. It was found that the pressure gradient, voidage, and solid height in the standpipe were affected by the pressure balance in the whole loop. By adjusting the gas flow rate and direction in the standpipe, the gas-solid slip velocity and pressure gradient changed correspondingly. Therefore, the standpipe could maintain the pressure balance and realize self-equilibrium of the loop by absorbing the pressure drop variations of other parts in the system

Investigation of the Lipid-Lowering Effect of Vitamin C Through GSK-3β/β-Catenin Signaling in Zebrafish

Vitamin C (VC) is an essential nutrient for most fish species because of the absence of L-gulonolactone oxidase in the bodies of fish. VC plays a significant role in maintaining the physiological functions and in improving the growth performance, immunity, and survival of fish. In this study, zebrafish (Danio rerio) were treated with 8.2, 509.6, and 1007.5 mg/kg VC diets for 2 weeks, and the muscle samples were collected for gene expression analysis and biochemical index analysis. The results indicated that 509.6 and 1007.5 mg/kg VC diets inhibited glycogen synthase kinase-3β (GSK-3β) expression and induced the expression of β-catenin in the muscle of zebrafish. The mRNA expression of CCAAT/enhancer-binding protein α (C/EBPα) and fatty acid synthase (FAS), FAS activity, and the content of glycerol and triglyceride (TG) were decreased in the muscle by 509.6 and 1007.5 mg/kg VC diets. In addition, GSK-3β RNA interference was observed in zebrafish fed with 8.2 and 1007.5 mg/kg VC diets. It was found that GSK-3β RNA interference induced the mRNA expression of β-catenin but decreased the mRNA expression of C/EBPα and FAS, FAS activity, as well as the content of glycerol and TG in the muscle of zebrafish. In ZF4 cells, the mRNA expression of GSK-3β, C/EBPα, and FAS was decreased, but β-catenin expression was increased by 0.1 and 0.5 mmol/L VC treatments in vitro. The glycerol and TG content, and FAS activity in ZF4 cells were decreased by 0.1 and 0.5 mmol/L VC treatments. Moreover, the result of western blot indicated that the protein expression level of GSK-3β was significantly decreased and that of β-catenin was significantly increased in ZF4 cells treated with 0.1 and 0.5 mmol/L VC. The results from in vivo and in vitro studies corroborated that VC exerted the lipid-lowering effect through GSK-3β/β-catenin signaling in zebrafish

Dynamic reliability sensitivity analysis for inter-story isolation structure under stochastic excitations

Considering the uncertainties of seismic excitation and stochastic parameters of the Inter-story Isolation Structure, the implicit structural response function is transformed into an explicit one by the Stochastic Response Surface Method (SRSM), combined with a probabilistic collocation method based on the linear independence principle. By using the reliability analysis method based on the first-passage failure, the reliability of isolation structure is analyzed and the sensitivity of the reliability of each sub-structure is further analyzed. The results show that conducting sensitivity research based on reliability analysis can provide an important theoretical basis for an optimized and robust design of a random vibration system. The changes of the stiffness and damping ratio of the Isolation Layer have a great influence on the reliability of the system and have different effects on the reliability of different parts of the system. The analysis results of reliability sensitivity could provide system reliability indexes to rank stochastic parameters by their importance, thus improving the efficiency of the structure reliability analysis and optimization design

Helicobacter zhangjianzhongii sp. nov., isolated from dog feces

In 2019, two distinct bacterial isolates were independently isolated from the fecal samples of separate dogs in Beijing, China. These cells exhibit microaerobic, are Gram-negative, motile, and possess a characteristic spiral shape with bipolar single flagellum. They display positive results for the oxidase test while being negative for both catalase and urease. These organisms measure approximately 0.2–0.3 μm in width and 4.5–6 μm in length. The colonies are wet, flat, grey, circular, and smooth with sizes ranging from 1 to 2 mm in diameter after 2 days of growth. However, strains may exhibit variations in size and morphology following extended incubation. Phylogenetic analyses based on the 16S rRNA gene and core genome indicated that these two isolates belong to the genus Helicobacter and formed a robust clade that was remains distinctly separate from currently recognized species. These two isolates shared low dDDH relatedness and ANI values with their closest species Helicobacter canis CCUG 32756T, with these values falling below the commonly cutoff values for strains of the same species. The genomic DNA G + C contents of strain XJK30-2 were 44.93 mol%. Comparing the phenotypic and phylogenetic features between these two isolates and their closely related species, XJK30-2 represents a novel species within the genus Helicobacter, for which the name Helicobacter zhangjianzhongii sp. nov. (Type strain XJK30-2T = GDMCC 1.3695T) is proposed

SMA1, a homolog of the splicing factor Prp28, has a multifaceted role in miRNA biogenesis in Arabidopsis

MicroRNAs (miRNAs) are a class of small non-coding RNAs that repress gene expression. In plants, the RNase III enzyme Dicer-like (DCL1) processes primary miRNAs (pri-miRNAs) into miRNAs. Here, we show that SMALL1 (SMA1), a homolog of the DEADbox pre-mRNA splicing factor Prp28, plays essential roles in miRNA biogenesis in Arabidopsis. A hypomorphic sma1-1 mutation causes growth defects and reduces miRNA accumulation correlated with increased target transcript levels. SMA1 interacts with the DCL1 complex and positively influences primiRNA processing. Moreover, SMA1 binds the promoter region of genes encoding pri-miRNAs (MIRs) and is required for MIR transcription. Furthermore, SMA1 also enhances the abundance of the DCL1 protein levels through promoting the splicing of the DCL1 pre-mRNAs. Collectively, our data provide new insights into the function of SMA1/Prp28 in regulating miRNA abundance in plants