8,066 research outputs found

    A homogenous nature of native Chinese duck matrilineal pool

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    <p>Abstract</p> <p>Background</p> <p>China, with around 30 unique breeds, has a diverse duck genetic pool. Currently, there is no systematic report which investigates the genetic diversity, phylogenetic relationship, and matrilineal genetic structure of these domestic breeds and wild mallards (<it>Anas platyrhynchos</it>).</p> <p>Results</p> <p>In this study, we sequenced the mitochondrial DNA (mtDNA) control region segments in 278 domestic ducks (<it>Anas platyrhynchos domestica</it>) from 19 indigenous breeds/populations and 70 wild mallard samples and analyzed them together with the 101 control region sequences from published sources. Fifty-two samples were then sequenced for a cytochrome <it>b </it>(Cyt <it>b</it>) gene fragment to solidify the pattern emerged from the control region sequences. All domestic duck and wild mallard haplotypes were essentially indistinguishable and were clustered together in the phylogenetic tree. There was no geographic differentiation and breed/population-specific distribution of duck lineages.</p> <p>Conclusion</p> <p>Our results showed that unlike other domesticated farm animals in China such as chicken, cattle, goat, and yak with multiple matrilineal components, the matrilineal pool of Chinese ducks was homogenous.</p

    Comparative analysis of SOFC-MGT top-level and new bottom-level system performance

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    In order to make the SOFC-MGT system more widely used, the mathematical simulation models of the SOFC-MGT top-level circulatory system and the new bottom circulatory system were first established, and then the performance of the two systems was analyzed and compared using Matlab/Simulink simulation software. The research results show that the output performance of the SOFC-MGT top-level circulation system is due to the new bottom-level circulation system, and the stack output performance of the two systems is not much different

    Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor

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    Alkali-doped iron selenide is the latest member of high Tc superconductor family, and its peculiar characters have immediately attracted extensive attention. We prepared high-quality potassium-doped iron selenide (KxFe2-ySe2) thin films by molecular beam epitaxy and unambiguously demonstrated the existence of phase separation, which is currently under debate, in this material using scanning tunneling microscopy and spectroscopy. The stoichiometric superconducting phase KFe2Se2 contains no iron vacancies, while the insulating phase has a \surd5\times\surd5 vacancy order. The iron vacancies are shown always destructive to superconductivity in KFe2Se2. Our study on the subgap bound states induced by the iron vacancies further reveals a magnetically-related bipartite order in the superconducting phase. These findings not only solve the existing controversies in the atomic and electronic structures in KxFe2-ySe2, but also provide valuable information on understanding the superconductivity and its interplay with magnetism in iron-based superconductors

    Identification of <em>CHIP</em> as a novel causative gene for autosomal recessive cerebellar ataxia

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    Autosomal recessive cerebellar ataxias are a group of neurodegenerative disorders that are characterized by complex clinical and genetic heterogeneity. Although more than 20 disease-causing genes have been identified, many patients are still currently without a molecular diagnosis. In a two-generation autosomal recessive cerebellar ataxia family, we mapped a linkage to a minimal candidate region on chromosome 16p13.3 flanked by single-nucleotide polymorphism markers rs11248850 and rs1218762. By combining the defined linkage region with the whole-exome sequencing results, we identified a homozygous mutation (c.493CT) in CHIP (NM_005861) in this family. Using Sanger sequencing, we also identified two compound heterozygous mutations (c.389AT/c.441GT; c.621C>G/c.707GC) in CHIP gene in two additional kindreds. These mutations co-segregated exactly with the disease in these families and were not observed in 500 control subjects with matched ancestry. CHIP colocalized with NR2A, a subunit of the N-methyl-D-aspartate receptor, in the cerebellum, pons, medulla oblongata, hippocampus and cerebral cortex. Wild-type, but not disease-associated mutant CHIPs promoted the degradation of NR2A, which may underlie the pathogenesis of ataxia. In conclusion, using a combination of whole-exome sequencing and linkage analysis, we identified CHIP, encoding a U-box containing ubiquitin E3 ligase, as a novel causative gene for autosomal recessive cerebellar ataxia

    Effects of crude fiber level on growth performance, serum biochemical indicators, and digestibility in zhedong white geese

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    The purpose of this study was to investigate the feasibility and supplementation level of rice hull as a dietary fiber source for geese. The effect of rice hull addition level on growth performance, serum biochemical indices, and digestive performance of geese was explored. Three hundred 28-day-old Zhedong white geese (half male and half female) with similar body weights were selected and divided into three groups. The crude fiber (CF) level of the groups was 4.8%, 6.1% and 6.9%, respectively. The pre-feeding period was 7 days, and the formal test period was 21 days. The growth performance and serum biochemical indexes, amylase, lipase, and protease activities, and apparent digestibility were determined. CF level of 6.1% and 6.9% were higher than 4.8%, but the feed/gain at 6.9% CF level was higher than that at 4.8% (P<0.05). Serum total cholesterol and high-density lipoprotein cholesterol concentrations decreased at CF levels of 6.1% and 6.9%, and insulin or insulin-like growth factor-1 levels were increased. The intestinal amylase activity at 6.9% CF level was lower than that at 6.1%. In contrast, pancreatic amylase activity at 6.9% CF level was higher than that at 4.8%. The digestibility of crude ash and crude fat in CF level of 6.9% and 6.1% were lower than that at 4.8%, whereas the digestibility of crude protein increased. Rice hull as the main fiber source, with fiber level between 6.1% and 6.9%, maintains growth performance and improves some beneficial serum biochemical indicator levels and crude protein digestibility

    Regular Patterns for Proteome-Wide Distribution of Protein Abundance across Species

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    A proteome of the bio-entity, including cell, tissue, organ, and organism, consists of proteins of diverse abundance. The principle that determines the abundance of different proteins in a proteome is of fundamental significance for an understanding of the building blocks of the bio-entity. Here, we report three regular patterns in the proteome-wide distribution of protein abundance across species such as human, mouse, fly, worm, yeast, and bacteria: in most cases, protein abundance is positively correlated with the protein's origination time or sequence conservation during evolution; it is negatively correlated with the protein's domain number and positively correlated with domain coverage in protein structure, and the correlations became stronger during the course of evolution; protein abundance can be further stratified by the function of the protein, whereby proteins that act on material conversion and transportation (mass category) are more abundant than those that act on information modulation (information category). Thus, protein abundance is intrinsically related to the protein's inherent characters of evolution, structure, and function

    Protein profiling in hepatocellular carcinoma by label-free quantitative proteomics in two west african populations.

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    Background Hepatocellular Carcinoma is the third most common cause of cancer related death worldwide, often diagnosed by measuring serum AFP; a poor performance stand-alone biomarker. With the aim of improving on this, our study focuses on plasma proteins identified by Mass Spectrometry in order to investigate and validate differences seen in the respective proteomes of controls and subjects with LC and HCC. Methods Mass Spectrometry analysis using liquid chromatography electro spray ionization quadrupole time-of-flight was conducted on 339 subjects using a pooled expression profiling approach. ELISA assays were performed on four significantly differentially expressed proteins to validate their expression profiles in subjects from the Gambia and a pilot group from Nigeria. Results from this were collated for statistical multiplexing using logistic regression analysis. Results Twenty-six proteins were identified as differentially expressed between the three subject groups. Direct measurements of four; hemopexin, alpha-1-antitrypsin, apolipoprotein A1 and complement component 3 confirmed their change in abundance in LC and HCC versus control patients. These trends were independently replicated in the pilot validation subjects from Nigeria. The statistical multiplexing of these proteins demonstrated performance comparable to or greater than ALT in identifying liver cirrhosis or carcinogenesis. This exercise also proposed preliminary cut offs with achievable sensitivity, specificity and AUC statistics greater than reported AFP averages. Conclusions The validated changes of expression in these proteins have the potential for development into high-performance tests usable in the diagnosis and or monitoring of HCC and LC patients. The identification of sustained expression trends strengthens the suggestion of these four proteins as worthy candidates for further investigation in the context of liver disease. The statistical combinations also provide a novel inroad of analyses able to propose definitive cut-offs and combinations for evaluation of performance
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