1,016 research outputs found
The Generalized Quasi-linearization Method for Reaction Diffusion Equations on an Unbounded Domain
AbstractThe method of generalized quasi-linearization has been well developed for ordinary differential equations. In this paper, we extend the method of generalized quasi-linearization to reaction diffusion equations on an unbounded domain. The iterates, which are solutions of linear equations starting from lower and upper solutions, converge uniformly and monotonically to the unique solution of the nonlinear reaction diffusion equation in an unbounded domain. Initially an existence theorem for the linear nonhomogeneous reaction diffusion equation in an unbounded domain has been proved under improved conditions. The quadratic convergence has been proved by using a comparison theorem of reaction diffusion equations with ordinary differential equations. This avoids the computational complexity of the quasi-linearization method, since the computation of Green's function at each stage of the iterates is avoided
Research of Multi-Information Integration for the Aircraft Ground De-icing Monitoring System Based on GIS and GPRS
Aiming at solving the problem of information dispersed, hysteresis even lost in the process of aircraft ground concentrated de-icing which reduce the efficiency and safety of the aircraft ground de-icing. A multi-information integration system of the whole process of the aircraft ground concentrated de-icing is designed in this paper, which describes the architecture and the function of the information integration system, proposes the hardware structure and implementation of software of the database server and the monitoring terminal. The simulation results show that the system can collect and show the information of the whole process of aircraft ground de-icing properly and provide an efficient monitoring platform for aircraft ground de-icing
Universal scaling of strange particle spectra in pp collisions
As a complementary study to that performed on the transverse momentum
() spectra of charged pions, kaons and protons in proton-proton (pp)
collisions at LHC energies 0.9, 2.76 and 7 TeV, we present a scaling behaviour
in the spectra of strange particles (, ,
and ) at these three energies. This scaling behaviour is
exhibited when the spectra are expressed in a suitable scaling variable
, where the scaling parameter is determined by the quality
factor method and increases with the center of mass energy (). The
rates at which increases with for these strange
particles are found to be identical within errors. In the framework of the
colour string percolation model, we argue that these strange particles are
produced through the decay of clusters that are formed by the colour strings
overlapping. We observe that the strange mesons and baryons are produced from
clusters with different size distributions, while the strange mesons (baryons)
and ( and ) originate from clusters
with the same size distributions. The cluster's size distributions for strange
mesons are more dispersed than those for strange baryons. The scaling behaviour
of the spectra for these strange particles can be explained by the
colour string percolation model in a quantitative way.Comment: 8 pages, 10 figures, accepted by EPJ
Structural Basis of Ligand Interaction with Atypical Chemokine Receptor 3
Chemokines drive cell migration through their interactions with seven-transmembrane (7TM) chemokine receptors on cell surfaces. The atypical chemokine receptor 3 (ACKR3) binds chemokines CXCL11 and CXCL12 and signals exclusively through β-arrestin-mediated pathways, without activating canonical G-protein signalling. This receptor is upregulated in numerous cancers making it a potential drug target. Here we collected over 100 distinct structural probes from radiolytic footprinting, disulfide trapping, and mutagenesis to map the structures of ACKR3:CXCL12 and ACKR3:small-molecule complexes, including dynamic regions that proved unresolvable by X-ray crystallography in homologous receptors. The data are integrated with molecular modelling to produce complete and cohesive experimentally driven models that confirm and expand on the existing knowledge of the architecture of receptor:chemokine and receptor:small-molecule complexes. Additionally, we detected and characterized ligand-induced conformational changes in the transmembrane and intracellular regions of ACKR3 that elucidate fundamental structural elements of agonism in this atypical receptor
The molecular and physicochemical mechanisms by which mushroom functional foods affect obesity associated metabolic diseases : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy
Obesity is rising around the world as a result of many factors, including an imbalance in food intake, an increased consumption of high-calorie diets, and a lack of physical exercise. Obesity not only leads to an increased risk for type 2 diabetes, cardiovascular disease and cancer, but also negatively affects longevity and quality of life. Anti-obesogenic approaches which are safe, widely available, and inexpensive are required to combat metabolic diseases. Mushrooms contain antioxidants, fibre and other phytochemicals, and have been shown to have anti-obesogenic and anti-diabetic effects through the modulation of diverse cellular and physiological pathways.
In this thesis, three edible mushroom species (white button mushroom, shiitake mushroom and oyster mushroom) were selected as sustainable and functional food ingredients. Wheat-flour noodles were enriched with mushroom powder sourced from different parts (cap, stem, whole) at different levels (5%, 10%, 15%) to investigate the effects of mushroom addition on the nutritional composition, physical and textural properties. Noodles containing mushrooms had a nutritional advantage with higher protein and dietary fibre contents compared with wheat-flour noodles. The addition of 15% mushroom powder in the noodles resulted in a significant (p < 0.05) decrease in glycaemic glucose equivalents after in vitro digestion. The antioxidant levels of the samples increased following the in vitro digestion, and were positively correlated with the fibre content (p<0.05). The stems of mushrooms acted as fibre-rich by-products and were able to regulate the glycaemic response of foods and increase antioxidants intake.
The noodles which contained 15% mushroom powder were used in a model food in a mice experiment. Male C57BL/6 mice were divided into four groups and fed with either one of the isocaloric diets as followed: standard chow diet group (CHOW), high-fat diet (HFD), HFD + 30% of wheat-flour noodles (HFD-FL), HFD + 30% shiitake mushroom noodles (HFD-SH), and HFD + 30% white button mushroom noodles (HFD-WB) and HFD + 30% oyster mushroom noodles (HFD-OY). After eight weeks of dietary intervention, all of the diets containing mushrooms were observed to ameliorate HFD-induced metabolic syndrome, with mice exhibiting decreased body weight gain, fat accumulation, glucose intolerance, and insulin resistance.
Dietary mushrooms reduced non-alcoholic fatty liver disease (NAFLD) in mice. Histological studies showed that mushroom diets significantly diminished the liver steatosis of mice compared with those fed with wheat-flour noodles. Analysis of serum markers further revealed decreased contents of total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C). The dysbiosis of the gut microbiome was shifted to the normal level, and the synthesis of bile acids was modulated by mushroom diets. Shiitake enriched diets altered the hepatic and faeces bile acid profile and activated farnesoid X receptor (FXR) signalling via downregulating the FXR antagonists (tauro-α-muricholic acid, tauro-β-muricholic acid). These changes in bile acids were correlated with the expansion of genera (Bacteroides, Akkermansia, Alloprevotella) in the gut microbiome. Shiitake acted as an aryl hydrocarbon receptor (AhR) ligand and a potent inducer of interleukin-22 (IL-22), suggesting its potential protective role in intestinal immunity. These results elucidate the nutraceutical functionalities of mushroom fortified foods via the signalling of bile acids together with the gut microbiome in the liver-gut axis, and provide the evidence of the further application of food matrix in treating and preventing metabolic diseases
Research on Aircraft Cable Defects Locating Method Based on Time-Frequency Domain Reflection
AbstractThis paper presents an aircraft cable fault detection and location method based on TFDR in order to detect the intermittent faults effectively and to cope with the serial and after-connector faults being difficult to be detected in time domain reflection. In this method, the correlation function of reflected and reference signal is utilized to detect and locate the aircraft fault according to the characteristics of reflected and reference signal in time-frequency domain, so the hit rate of detecting and locating intermittent faults can be improved effectively. In the work process, the reflected signal is interfered by the noise and false alarm takes place frequently, so the threshold de-noising method based on wavelet decomposition is utilized to decrease the noise interference and reduce the fault alarm rate. Then the time-frequency cross correlation function of the reference signal and the reflected signal based on Wigner-Ville distribution is computed in order to locate the fault position. At last, LabVIEW is applied to implement operation and control interface, the main function of which is to link and control MATLAB and LABSQL. Utilizing the strong calculating capability and the abundant function library of MATLAB, the signal processing turn to be easily realized, moreover LabVIEW help the system to be more reliable and updated easily
- …