57,763 research outputs found
Evolution of the G+C content frontier in the rat cytomegalovirus genome
No full textWithin the 230138 bp of the rat cytomegalovirus (RCMV) genome, the G+C content changes abruptly at position 142644, constituting a G+C content frontier. To the left of this point, overall G+C content is 69.2%, and to the right it is only 47.6%. A region of extremely low G+C content (33.8%) is found in the 5 kb immediately to the right of the frontier, in which there are no predicted coding sequences. To the right of position 147501, the G+C content rises and predicted coding sequences reappear. However, these genes are much shorter (average 848bp, 50% G+C) than those in the left two-thirds of the genome (average 1462bp, 70% G+C). Whole genome alignment of several viruses indicates that the initial ultra-low G+C region appeared in the common ancestor of the genera Cytomegalovirus and Muromegalovirus, and that the lowering of G+C in the right third has been a subsequent process in the lineage leading to RCMV. The left two-thirds of RCMV has stop codon occurrences at 67.5% of their expected level, based on a modified Markov chain model of stop codon distribution, and the corresponding figure for the right third is 78%. Therefore, despite heavy mutation pressure, selective constraint has operated in the right third of the RCMV genome to maintain a degree of gene length unusual for such low G+C sequences
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
c-myc and c-myb oncoproteins during induced maturation of myeloid and erythroid human leukemic cell lines
No full textc-myc and c-myb mRNAs have been found to be tightly regulated during hemopoietic differentiation. We have studied nuclear c-myc and c-myb oncoproteins through the cell cycle, during macrophage, granulocyte, erythroid, and megakaryocytic differentiation of KG1, HL60, and HEL cells. p62c-myc and p75c-myb content of propidium iodide-stained nuclei was quantitated by flow cytometry using fluoresceinated antibodies CT14-G4 and MB4.3, respectively. In uninduced cells p62c-myc content is highest in HL60, followed by HEL, then KG1, while p75c-myb is highest in HEL, followed by HL60 and KG1. All lines showed a less than 2-fold increment in both oncoproteins over the cell cycle. Macrophage induction of KG1 and HL60 resulted in early increase in both oncoproteins, followed by a decline to less than starting values by 48 h, concurrent with a reduction of S phase cells and the appearance of adherent alpha-naphthyl acetate esterase-positive cells. p62c-myc changes were more pronounced in HL60 and p75c-myb changes in KG1. Different patterns of oncoprotein expression were found when different inducing agents were used for granulocyte differentiation of HL60. Under all conditions, however, both oncoproteins declined to basal levels before granulocyte maturity. Hemin-induced erythroid differentiation of HEL to hemoglobin-containing cells resulted in biphasic p62c-myc and p75c-myb kinetics. In contrast, dimethyl sulfoxide-induced megakaryocytic differentiation of HEL was accompanied by an early and steady decline in both oncoproteins. Despite considerable reduction in oncoprotein levels, HEL cells were still actively cycling at 120 h. It appears that c-myc and c-myb proteins decline with differentiation, well before proliferation ceases in some lineages. The kinetics of the decline differ between the two oncogenes and vary with the lineage induced and the nature of the inducing agent used. The cell cycle distribution of the oncoproteins does not change during maturation. These data suggest disparate roles for c-myc versus c-myb during hemopoietic differentiation and the existence of multiple signal transduction pathways for down-regulation of these genes
R. Iredale, N. Bilik, S. Wang, G. Fei et C. Hoy, Contemporary Minority Migration, Education and Ethnicity in China, Glos, Edward Elgar, 2001, 275 p.
No full textAttané Isabelle. R. Iredale, N. Bilik, S. Wang, G. Fei et C. Hoy, Contemporary Minority Migration, Education and Ethnicity in China, Glos, Edward Elgar, 2001, 275 p.. In: Perspectives chinoises, n°71, 2002. pp. 86-87
Acute Ethanol Administration Rapidly Increases Phosphorylation of Conventional Protein Kinase C in Specific Mammalian Brain Regions in Vivo
No full textBackground
Protein kinase C (PKC) is a family of isoenzymes that regulate a variety of functions in the central nervous system including neurotransmitter release, ion channel activity, and cell differentiation. Growing evidence suggests that specific isoforms of PKC influence a variety of behavioral, biochemical, and physiological effects of ethanol in mammals. The purpose of this study was to determine whether acute ethanol exposure alters phosphorylation of conventional PKC isoforms at a threonine 674 (p-cPKC) site in the hydrophobic domain of the kinase, which is required for its catalytic activity.
Methods
Male rats were administered a dose range of ethanol (0, 0.5, 1, or 2 g/kg, intragastric) and brain tissue was removed 10 minutes later for evaluation of changes in p-cPKC expression using immunohistochemistry and Western blot methods.
Results
Immunohistochemical data show that the highest dose of ethanol (2 g/kg) rapidly increases p-cPKC immunoreactivity specifically in the nucleus accumbens (core and shell), lateral septum, and hippocampus (CA3 and dentate gyrus). Western blot analysis further showed that ethanol (2 g/kg) increased p-cPKC expression in the P2 membrane fraction of tissue from the nucleus accumbens and hippocampus. Although p-cPKC was expressed in numerous other brain regions, including the caudate nucleus, amygdala, and cortex, no changes were observed in response to acute ethanol. Total PKC? immunoreactivity was surveyed throughout the brain and showed no change following acute ethanol injection
Author Correction: A corridor of exposed ice-rich bedrock across Titan’s tropical region (Nature Astronomy, (2019), 3, 7, (642-648), 10.1038/s41550-019-0756-5)
No full textIn the version of this Article originally published, the author Rosaly Lopes was mistakenly affiliated with Northern Arizona University. Her affiliation has now been corrected to: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. © 2019, Springer Nature Limited
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Imaging of mice and men; adventures in multispectral imaging
No full textCancer of the brain and CNS account for only 2% of new cancer cases in the UK however it is responsible for 7% of cancer deaths of those aged under 70 years of age. Although surgery falls short of a cure it is the primary method of treatment. Two of the key problems in tumour surgery in the brain are a) that many tumours are visually indistinguishable from normal tissue even for experienced surgeons and b) that the risk of post-surgical neurological deficit is related to the proximity of functional (or 'eloquent') neurological tissue. In collaboration with surgeons at the Southampton University NHS Hospitals Trust we seek to address both of these problems. Firstly there is literature evidence that normal and neoplastic tissue have different spectral characteristics in the visible and near-infrared region. We investigate whether these can be practically imaged intraoperatively to establish disease state. Secondly the redox state of haemoglobin is known to affect it's visible and near-infrared spectral characteristics. This project investigates whether it is possible to identify the haemodynamic response associated with functional activity intraoperatively in the human brain. Prion diseases are fatal chronic neurodegenerative diseases of animals and man. They have gained notoriety due to recent outbreaks of Bovine Spongiform Encephalopathy (BSE) and the evidence that they can be transmitted between species, including to man. Exposure to BSE infected material has been shown to cause variant Creutzfeldt-Jacob disease in man. Prion disease is also used as a model of other neurodegenerative diseases, such as Alzheimers disease. Remarkably little is known about this class of disease including the specific cause of the neurodegeneration. Prions are a mis-folded protein which have a different conformation than the normal protein. Certain spectral features in the mid infrared region are associated with protein conformation. In collaboration with neuro-biologists within the university and using a synchrotron light source we investigate the application of multispectral imaging in early stage prion disease. By analysis of the protein conformation sensitivity of the mid infrared spectra (with particular interest in the Amide I band) we seek to identify structurally relevant markers in a mouse model before clinical symptoms of the disease are evident. This may lead to better understanding of the disease progression and the neurotoxic element
DFT and experimental study of elemental mercury (Hg<sup>0</sup>) removal by 2D-g-C<sub>3</sub>N<sub>4</sub>
No full text2D-g-C3N4 nanosheet was prepared and employed for the adsorption of elemental mercury (Hg0). The g-C3N4 was analyzed through X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) methods, and the results showed that the prepared sample was well-defined 2D-nanosheet. The 2D-g-C3N4 sorbent exhibited a high Hg0 removal efficiency (> 90%) at the condition of temperature 120 °C. To investigate the mechanism of Hg0 adsorption on the 2D-g-C3N4 surface, corresponding theoretical exploration based on the first principle prediction and X-ray photoelectron spectroscopy (XPS) test was implemented. The DFT calculation results showed that Hg0 was strongly bound to the B1 site of the g-C3N4 surface with an adsorption energy change of -162.2 kJ mol−1, the equilibrium distance of Hg-C was 3.473 Å, and electron transfer between Hg and C atoms was 0.02. The results of XPS showed the main species of mercury was HgO on the surface of 2D-g-C3N4 sample and the interaction between C3N4 surface and Hg0 was physisorption. This study provides a demonstration of proof-of-concept demonstration that g-C3N4 is a promising sorbent capable of capturing Hg0, and presents in-depth understanding of Hg0 adsorption mechanism on 2D-g-C3N4 sorbent.Sanitary Engineerin
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