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The dipeptide DL-methionyl-DL-Methionine (Met-Met) has extremely low water solubility and better absorption than other methionine sources (such as DL-methionine and L-methionine) available in the market. Therefore, six diets (D1, D2, D3, D4, D5 and D6) containing 0 %, 0.07%, 0.15%, 0.21%, 0.28% and 0.38% Met-Met were formulated to investigate the effects of Met-Met on Oreochromis niloticus. The results indicated that percent weight gain and specific growth rate of fish fed with D2 and D3 diets were higher than those fed with D1, D4-D6 diets. The levels of total essential amino acid in whole body of fish fed with D3 and D4 diets were significantly higher than those fed the D1 diet. Superoxide dismutase activity and malondialdehyde content were no significant difference in fed the diet with or without Met-Met supplementation. Majority of reads derived from the fish intestines belonged to members of Fusobacteria, followed by Bacteroidetes, Proteobacteria. Diversity of intestinal microbiota and total antioxidant capacity in fish fed with D3 diet was significantly higher than that of other groups. Since due to the growth results the authors conclude the optimal proportion of Met was 0.61%, and the addition of Met-Met was 0.15% in O. niloticus.
North-east China occupies an important geographic position for understanding the process of Neolithisation in East Asia. Although archaeologists have long debated the trajectory of change in this region, a lack of intensive survey and excavation has precluded convincing interpretations. This article presents research on the newly excavated sites of Huayang and Taoshan in the southern Lesser Khingan Mountains, with a particular focus on the lithic assemblages. Comparative and environmental analyses demonstrate the largely uniform trajectory of lithic technologies across north-east China and close correspondence with Late Glacial palaeoclimatic and palaeoenvironmental changes.
This study examined Echinococcus spp. genotypes and genetic variants isolated from humans as well as domestic and wild animals from the Qinghai-Tibetan Plateau Area using the cox1 gene. All samples except the pika isolates were identified as the Echinococcus granulosus sensu stricto. Sixteen different haplotypes with considerable intraspecific variation were detected and characterized in mitochondrial cox1 sequences. The parsimonious network of cox1 haplotypes showed star-like features, and the neutrality indexes computed via Tajima's D and Fu's Fs tests showed high negative values in E. granulosus s. s., indicating deviations from neutrality; the Fst values were low among the populations, implying that the populations were not genetically differentiated. The pika isolates were identified as E. multilocularis and E. shiquicus. Only one haplotype was recognized in the pika isolates. E. granulosus s. s. was the predominant species found in animals and humans, followed by E. multilocularis and E. shiquicus, with high genetic diversity circulating among the animals and humans in this area. Further studies are needed to cover many sample collection sites and larger numbers of pathogen isolates, which may reveal abundant strains and/or other haplotypes in the hydatid cysts infecting human and animal populations of the QTPA, China.
Compared with commercial polyolefin membranes, polyacrylonitrile (PAN) membrane prepared by electrostatic spinning has higher porosity, electrolyte uptake, thermal stability, and lithium-ion conductivity, etc. However, poor mechanical performance has largely limited the application of electrospun PAN separators. In this study, PAN/polyimide (PI) composite membrane is prepared by electrostatic spinning to improve the mechanical and electrochemical performances. Scanning electron microscopy, thermal analysis method, and electrochemical methods were used for evaluation of the electrospun composite membrane. The results show that the composite membrane possesses good thermal stability and exhibits better mechanical performance than pristine PAN membrane (increasing by 1.1 times in tension strength). The addition of PI can increase porosity and fluid absorption rate obviously. In addition, the composite membrane has high ionic conductivity (18.77 × 10−4 S/cm), wide electrochemical window (about 4.0 V), and excellent cycling performance. It can retain a discharge specific capacity of 153 mA h/g even after 50 cycles at 0.5 C. The electrospun PAN/PI membrane may be a promising candidate for lithium-ion battery separators.
To investigate the protein-sparing effect of α-lipoic acid (LA), experimental fish (initial body weight: 18·99 (sd 1·82) g) were fed on a 0, 600 or 1200 mg/kg α-LA diet for 56 d, and hepatocytes were treated with 20 μm compound C, the inhibitor of AMP kinase α (AMPKα), treated for 30 min before α-LA treatment for 24 h. LA significantly decreased lipid content of the whole body and other tissues (P<0·05), and it also promoted protein deposition in vivo (P<0·05). Further, dietary LA significantly decreased the TAG content of serum and increased the NEFA content of serum (P<0·05); however, there were no significant differences among all groups in the hepatopancreas and muscle (P>0·05). Consistent with results from the experiment in vitro, LA activated phosphorylation of AMPKα and notably increased the protein content of adipose TAG lipase in intraperitoneal fat, hepatopancreas and muscle in vivo (P<0·05). Meanwhile, LA significantly up-regulated the mRNA expression of genes involved in fatty acid β-oxidation in the same three areas, and LA also obviously down-regulated the mRNA expression of genes involved in amino acid catabolism in muscle (P<0·05). Besides, it was observed that LA significantly activated the mammalian target of rapamycin (mTOR) pathway in muscle of experimental fish (P<0·05). LA could promote lipolysis and fatty acid β-oxidation via increasing energy supply from lipid catabolism, and then, it could economise on the protein from energy production to increase protein deposition in grass carp. Besides, LA might directly promote protein synthesis through activating the mTOR pathway.
Suboptimal vitamin B2 status is encountered globally. Riboflavin deficiency depresses growth and results in a fatty liver. The underlying mechanisms remain to be established and an overview of molecular alterations is lacking. We investigated hepatic proteome changes induced by riboflavin deficiency to explain its effects on growth and hepatic lipid metabolism. In all, 360 1-d-old Pekin ducks were divided into three groups of 120 birds each, with twelve replicates and ten birds per replicate. For 21 d, the ducks were fed ad libitum a control diet (CAL), a riboflavin-deficient diet (RD) or were pair-fed with the control diet to the mean daily intake of the RD group (CPF). When comparing RD with CAL and CPF, growth depression, liver enlargement, liver lipid accumulation and enhanced liver SFA (C6 : 0, C12 : 0, C16 : 0, C18 : 0) were observed. In RD, thirty-two proteins were enhanced and thirty-one diminished (>1·5-fold) compared with CAL and CPF. Selected proteins were confirmed by Western blotting. The diminished proteins are mainly involved in fatty acid β-oxidation and the mitochondrial electron transport chain (ETC), whereas the enhanced proteins are mainly involved in TAG and cholesterol biosynthesis. RD causes liver lipid accumulation and growth depression probably by impairing fatty acid β-oxidation and ETC. These findings contribute to our understanding of the mechanisms of liver lipid metabolic disorders due to RD.
Excited by the great success of metal halide perovskites in the optoelectronic and electro-optic fields and the interesting emerging physics (Rashba splitting, quantum anomalous hall effect) of layered metal halides, metal halides have recently been attracting significant attentions from both research and industrial communities. It is shown that most progresses have been made when these materials are obtained at reduced dimensions. Among several growth methods, vapor phase epitaxy has been demonstrated with a universal control on morphology, phase, and composition. We thus believe that a thorough understanding on the physical properties and on the growth of general metal halide compounds at reduced dimensions would be very beneficial in the study of recent perovskites and layered metal halide materials. This review covers the physical properties of most studied metal halides and summarizes the vapor phase epitaxial growth knowledge collected in the past century. We hope that this comprehensive review could be helpful in designing new physical properties and in planning growth parameters for emerging metal halide crystals.
Partial differential equations (PDE) on manifolds arise in many areas, including mathematics and many applied fields. Due to the complicated geometrical structure of the manifold, it is difficult to get efficient numerical method to solve PDE on manifold. In the paper, we propose a method called point integral method (PIM) to solve the Poisson-type equations from point clouds. Among different kinds of PDEs, the Poisson-type equations including the standard Poisson equation and the related eigenproblem of the Laplace-Beltrami operator are one of the most important. In PIM, the key idea is to derive the integral equations which approximates the Poisson-type equations and contains no derivatives but only the values of the unknown function. This feature makes the integral equation easy to be discretized from point cloud. In the paper, we explain the derivation of the integral equations, describe the point integral method and its implementation, and present the numerical experiments to demonstrate the convergence of PIM.
Tungstate based phosphors have efficient absorption in the UV region and can be used for UV-pumped light emitting. For novel and effective materials and synthesis methods in this system, a series of Eu3+ and Tb3+ co-doped NaY(WO4)2 phosphors have been synthesized via the molten salt method. The powder X-ray diffraction (PXRD) patterns, scanning electronic microscope (SEM), and photoluminescent spectra have been characterized for the prepared samples. The results show the flux (NaCl) not only decreases the reaction temperature (700–900 °C) than the normal solid state synthesis (∼1000 °C), but also controls the morphology of the products. The shape and size of products can be changed simply and effectively by the reaction conditions, such as temperature and heating time. It is also found that the emission colors of the samples can be tuned from red to green by simply adjusting the doping concentrations of Eu3+ and Tb3+ ions under the same wave length excitation, which has potential applications for multi-color display and illumination as a single-component phosphor.
Semi-Lagrangian (S-L) methods have no CFL stability constraint, and are more stable than the Eulerian methods. In the literature, the S-L method for the level-set re-initialization equation was complicated, which may be unnecessary. Since the re-initialization procedure is auxiliary, we propose to use the first-order S-L scheme coupled with a projection technique to improve the accuracy at the grid points just adjacent to the interface. Standard second-order S-L method is used for evolving the level-set convection equation. The implementation is simple, including on the block-structured adaptive mesh. The efficiency of the S-L method is demonstrated by extensive numerical examples including passive convection of interfaces with corners/kinks/large deformation under given velocity fields, a geometrical flow with topological changes, simulations of bubble/ droplet dynamics in incompressible two-phase flows. In terms of accuracy it is comparable to the other existing methods.
is a prime with
. A relation between the support weight distribution of a linear code
and the dual code
Little is known about the status of the snow leopard Panthera uncia in Qomolangma National Nature Reserve, located on the northern aspect of Mount Everest in Tibet. To address this, during May–September 2014 we conducted line transects, camera trapping, household interviews, and socioeconomic statistics analysis. We surveyed 14 transects and located 287 putative snow leopard signs, with a mean density of 1.9 sign sites km–1, 3.8 signs km–1, and 1.4 scrapes km–1. We set 41 camera traps and recorded a minimum of seven individual snow leopards. Our results were comparable to snow leopard abundance estimates for neighbouring protected areas in Nepal. Semi-structured interviews with 46 (59%) households found that local people were generally supportive of snow leopard conservation, for a variety of economic, legislative, and religious reasons. The socio-economic situation in the Reserve underwent dramatic changes between 2000 and 2014. The human population increased by 28.9%, the livestock population decreased by 9.9%, the number of tourists in 2014 was 6.8 times greater than in 2005, and the local gross domestic product underwent an annual increase of 15%. We discuss the current threats to snow leopards, and recommend that more rigorous, comprehensive, and interdisciplinary research be undertaken to provide an evidential basis for the formulation of effective conservation policies and programmes.
Observations (Espey et al. 1989, Carswell et al. 1991, Marziani et al. 1996) at high resolution have shown relative shifts between the Balmer lines and the C iv line in a number of QSOs. In this paper, we suggest that in the BLR there are many cloudlets with dense gas that is optically thick, and the BLR is not only illuminated by UV-X radiation, but also by relativistic electrons. Therefore the Čerenkov line radiation has to be taken into consideration, and we calculate the Čerenkov line redshifts and the profiles.
In 1980, You & Cheng (1980) suggested that in a dense gas medium, relativistic electrons will produce Čerenkov atomic or molecular emission lines of widths Δλ ≈ 1 – 10Å. The Čerenkov line is broader than a normal emission line and has small redshift (ΔZc ≡ Δλp/λlu ≈ 10–3), so the apparent velocity is about a few hundred km s−1. We refer to this as the ‘Čerenkov redshift’. In 1986, You & Cheng gave simplified formulae for Čerenkov line emission and the mechanism was confirmed by a series of elegant experiments (Xu et al. 1988, 1989). Recent progress in studies of AGNs, both in theory and observation, provide support for the Čerenkov line-emission model of the BLR of AGNs. In this paper, we prove that for a dense gas, if there are enough relativistic electrons, the Čerenkov line emission is strong enough to compare with the observations, and the Čerenkov line emission dominates over the spontaneous emission lines in the optically thick case.
Vertical Integrative Analysis (General Methods)
Jin Liu, Duke-NUS Graduate Medical School,
Xingjie Shi, Shanghai University of Finance and Economics, China,
Jian Huang, University of Iowa,
Shuangge Ma, Capital University of Economics and Business, China
With omics data, results generated from single-dataset analysis are often unsatisfactory. Integrative analysis methods conduct the joint analysis of data from multiple independent studies or on multiple correlated responses, can effectively increase power, and outperform single-dataset analysis and meta-analysis. In this chapter, we review the penalized integrative analysis methods under both the homogeneity and heterogeneity models. Computation using the coordinate descent approach is described. We also discuss several important extensions. The analysis of a genome-wide association study demonstrates the applicability of reviewed methods.
In the study of complex diseases such as cancer, cardiovascular diseases, and autoimmune diseases, profiling studies are nowroutinely conducted, generating “large d, small n” data, where the number of omics features profiled (genes, SNPs, methylation loci, etc.) d is much larger than the sample size n. Many different types of analyses can be conducted. For example, Chapters 3 and 4 were focused on identifying meaningful networks. In this chapter, our analysis goal is to identify a small subset of omics measurements that are associated with disease outcomes or phenotypes. Such measurements are also referred to as “markers” in the literature and in this chapter. Statistically, this is a variable selection problem. The development of integrative analysis methods has been partly motivated by the following examples.
8.1.1 Example 1
Consider the analysis of data generated in multiple independent studies with comparable designs. For example, in Ma et al. (2011), four pancreatic cancer data sets are collected and analyzed. The four data sets were generated in four independent studies, all having a case-control design, collecting mRNA gene expression measurements and searching for genes associated with the risk of pancreatic cancer. In high-dimensional omics studies, it has been recognized that the results generated in single-data-set analysis often have unsatisfactory properties such as low reproducibility. Among many possible contributing factors, the most important one is perhaps the small n. Multi-data-set analysis can effectively increase sample size and outperform single-data-set analysis (Guerra and Goldstein, 2009). This perspective has been explained in multiple chapters of this book. When the designs of multiple studies are “close enough”, it can be reasonable to expect that they identify the same set of markers.
The NASA Kepler satellite has provided unprecedented high duty-cycle, high-precision light curves for a large number of stars by continuously monitoring a field of view in Cygnus-Lyra region, leading to great progress in both discovering exoplanets and characterizing planet-hosting stars by means of asteroseismic methods. The asteroseismic survey allows the investigation of stars covering the whole H-R diagram. However, the low precision of effective temperatures and surface gravities in the KIC catalogue and the lack of information on chemical composition, metallicity and rotation rate prevent asteroseismic modeling, requiring spectroscopic observations for thousands of asteroseismic targets in the Kepler field in a homogeneous way.
As a recently proposed concept, multiple-input multiple-output (MIMO) radars exhibit much higher spatial resolution than traditional transmitter based radars because of the synthesized virtual array. In this paper, the problem of minimum redundancy (MR)-MIMO array synthesis is addressed, which seeks to maximize the virtual array aperture of MIMO radars for a given number of transmitting and receiving elements. A hybrid method combining autocorrelation property of cyclic difference sets (CDSs) and global search characteristics of ant colony optimization (ACO) is proposed for a rapid and numerically-effective exploration of MR-MIMO array configurations. Numerical experiments validate the proposed method, showing improvements in convergence rate and computational cost with respect to bare ACO-based search as well as improvements in the generality and configuration variety with respect to the CDS-based method.