1,014 research outputs found

    Partitioning of Phenylalanine Ammonia-lyase from Rhodotorula glutinis in Aqueous Two-phase Systems of PEG/salts

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    In this work, the partitioning of phenylalanine ammonia-lyase was investigated in different systems of PEG1000, PEG2000, PEG3350, PEG6000 and PEG8000 with (NH4)2SO4, Na2SO4, Na2CO3 and potassium phosphate. The results showed that the partition of phenylalanine ammonia-lyase in PEG/salt aqueous two-phase systems was mainly influenced by hydrophobicity, excluded volume effect and salting-out effect; compared with other PEG/salt systems, PEG1000/Na2SO4 was the most effective for phenylalanine ammonia-lyase partitioning. The result further supports that PEG/salt aqueous two-phase system provides a new and applicable route for the purification of phenylalanine ammonia-lyase, as shown in our published paper.1

    The HI Bias during the Epoch of Reionization

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    The neutral hydrogen (HI) and its 21 cm line are promising probes to the reionization process of the intergalactic medium (IGM). To use this probe effectively, it is imperative to have a good understanding on how the neutral hydrogen traces the underlying matter distribution. Here we study this problem using semi-numerical modeling by combining the HI in the IGM and the HI from halos during the epoch of reionization (EoR), and investigate the evolution and the scale-dependence of the neutral fraction bias as well as the 21 cm line bias. We find that the neutral fraction bias on large scales is negative during reionization, and its absolute value on large scales increases during the early stage of reionization and then decreases during the late stage. During the late stage of reionization, there is a transition scale at which the HI bias transits from negative on large scales to positive on small scales, and this scale increases as the reionization proceeds to the end.Comment: 11 pages, 11 figures, MNRAS accepte

    Towards Omni-Tomography—Grand Fusion of Multiple Modalities for Simultaneous Interior Tomography

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    We recently elevated interior tomography from its origin in computed tomography (CT) to a general tomographic principle, and proved its validity for other tomographic modalities including SPECT, MRI, and others. Here we propose “omni-tomography”, a novel concept for the grand fusion of multiple tomographic modalities for simultaneous data acquisition in a region of interest (ROI). Omni-tomography can be instrumental when physiological processes under investigation are multi-dimensional, multi-scale, multi-temporal and multi-parametric. Both preclinical and clinical studies now depend on in vivo tomography, often requiring separate evaluations by different imaging modalities. Over the past decade, two approaches have been used for multimodality fusion: Software based image registration and hybrid scanners such as PET-CT, PET-MRI, and SPECT-CT among others. While there are intrinsic limitations with both approaches, the main obstacle to the seamless fusion of multiple imaging modalities has been the bulkiness of each individual imager and the conflict of their physical (especially spatial) requirements. To address this challenge, omni-tomography is now unveiled as an emerging direction for biomedical imaging and systems biomedicine

    Colias IV: The Affordable Micro Robot Platform with Bio-inspired Vision

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    Vision is one of the most important sensing modalities for robots and has been realized on mostly large platforms. However for micro robots which are commonly utilized in swarm robotic studies, the visual ability is seldom applied or with only limited functions and resolution, due to the challenging requirements on the computation power and high data volume to deal with. This research has proposed the low-cost micro ground robot Colias IV, which is particularly designed to meet the requirements to allow embedded vision based tasks onboard, such as bio-inspired collision detection neural networks. Numerous of successful approaches have demonstrated that the proposed micro robot Colias IV to be a feasible platform for introducing visual based algorithms into swarm robotics

    Novel and Recurrent Mutations of WISP3 in Two Chinese Families with Progressive Pseudorheumatoid Dysplasia

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    BACKGROUND: The WNT1-inducible signaling pathway protein 3 (WISP3), which belongs to the CCN (cysteine-rich protein 61, connective tissue growth factor, nephroblastoma overexpressed) family, is a secreted cysteine-rich matricellular protein that is involved in chondrogenesis, osteogenesis and tumorigenesis. WISP3 gene mutations are associated with progressive pseudorheumatoid dysplasia (PPD, OMIM208230), an autosomal recessive genetic disease that is characterized by the swelling of multiple joints and disproportionate dwarfism. METHODOLOGY/PRINCIPAL FINDINGS: Four PPD patients from two unrelated Chinese families were recruited for this study. The clinical diagnosis was confirmed by medical history, physical examinations, laboratory results and radiological abnormalities. WISP3 mutations were detected by direct DNA sequence analysis. In total, four different mutations were identified, which consisted of two missense mutations, one deletion and one insertion that spanned exons 3, 5 and 6 of the WISP3 gene. One of the missense mutations (c.342T>G/p.C114W) and a seven-base pair frameshift deletion (c.716_722del/p.E239fs*16) were novel. The other missense mutation (c.1000T>C/p. S334P) and the insertion mutation (c.866_867insA/p.Q289fs*31) had previously been identified in Chinese patients. All four cases had a compound heterozygous status, and their parents were heterozygous carriers of these mutations. CONCLUSIONS/SIGNIFICANCE: The results of our study expand the spectrum of WISP3 mutations that are associated with PPD and further elucidate the function of WISP3

    The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey

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    We report on extragalactic sources detected in a 455 square-degree map of the southern sky made with data at a frequency of 148 GHz from the Atacama Cosmology Telescope 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15 to 1500 mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies. Three of the sources appear to be associated with the brightest cluster galaxies of low redshift X-ray selected galaxy clusters. Estimates of the radio to mm-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (>50 mJy) 148 GHz-selected sample with complete cross-identifications from the Australia Telescope 20 GHz survey, we observe an average steepening of the spectra between 5, 20, and 148 GHz with median spectral indices of α520=0.07±0.06\alpha_{\rm 5-20} = -0.07 \pm 0.06, α20148=0.39±0.04\alpha_{\rm 20-148} = -0.39 \pm0.04, and α5148=0.20±0.03\alpha_{\rm 5-148} = -0.20 \pm 0.03. When the measured spectral indices are taken into account, the 148 GHz differential source counts are consistent with previous measurements at 30 GHz in the context of a source count model dominated by radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20 mJy is C^{\rm Sync} = (2.8 \pm 0.3) \times 10^{-6} \micro\kelvin^2.Comment: Accepted to Ap

    The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectrum at 148 and 218 GHz from the 2008 Southern Survey

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    We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results clearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the {\Lambda}CDM cosmological model. At l > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < l < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8{\sigma} level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.Comment: 19 pages, 13 figures. Submitted to ApJ. This paper is a companion to Hajian et al. (2010) and Dunkley et al. (2010

    A Novel Splicing Mutation Alters DSPP Transcription and Leads to Dentinogenesis Imperfecta Type II

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    Dentinogenesis imperfecta (DGI) type II is an autosomal dominant disease characterized by a serious disorders in teeth. Mutations of dentin sialophosphoprotein (DSPP) gene were revealed to be the causation of DGI type II (DGI-II). In this study, we identified a novel mutation (NG_011595.1:g.8662T>C, c.135+2T>C) lying in the splice donor site of intron 3 of DSPP gene in a Chinese Han DGI-II pedigree. It was found in all affected subjects but not in unaffected ones or other unrelated healthy controls. The function of the mutant DSPP gene, which was predicted online and subsequently confirmed by in vitro splicing analysis, was the loss of splicing of intron 3, leading to the extended length of DSPP mRNA. For the first time, the functional non-splicing of intron was revealed in a novel DSPP mutation and was considered as the causation of DGI-II. It was also indicated that splicing was of key importance to the function of DSPP and this splice donor site might be a sensitive mutation hot spot. Our findings combined with other reports would facilitate the genetic diagnosis of DGI-II, shed light on its gene therapy and help to finally conquer human diseases
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