378 research outputs found
H5N1 chicken influenza viruses display a high binding affinity for Neu5Acα2-3GalÎČ1-4(6-HSO3)GlcNAc-containing receptors
AbstractTo characterize differences in the receptor-binding specificity of H5N1 chicken viruses and viruses of aquatic birds, we used a panel of synthetic polyacrylamide (PAA)-based sialylglycopolymers that carried identical terminal Neu5Acα2-3Gal fragments but varied by the structure of the next saccharide residues. A majority of duck viruses irrespective of their HA subtype, bound with the highest affinity to trisaccharide Neu5Acα2-3GalÎČ1-3GlcNAc, suggesting that these viruses preferentially recognize sialyloligosaccharide receptors with type 1 core (GalÎČ1-3GlcNAc). Substitution of 6-hydroxyl group of GlcNAc residue of tested sialylglycopolymers by 6-sulfo group had little effect on receptor binding by duck viruses. By contrast, H5N1 chicken and human viruses isolated in 1997 in Hong Kong preferred receptors with type 2 core (GalÎČ1-4GlcNAcÎČ) and bound sulfated trisaccharide Neu5Acα2-3GalÎČ1-4(6-HSO3)GlcNAcÎČ (6-Su-3âČSLN) with the extraordinary high affinity. Another chicken virus, A/FPV/Rostok/34 (H7N1), and several mammalian viruses also displayed an increased affinity for sulfated sialyloligosaccharide receptor. The binding of chicken and mammalian viruses to tracheal epithelial cells of green monkey decreased after treatment of cells with glucosamine-6-sulfatase suggesting the presence of 6-O-Su-3âČSLN determinants in the airway epithelium. It remains to be seen whether existence of the 6-O-Su-3âČSLN groups in the human airway epithelial cells might facilitate infection of humans with H5N1 chicken viruses
Optimised ICP-MS quantification method for using animal faeces as a measure of protected area ecosystem health
Pollution is a key threat to biodiversity and ecosystem health within protected areas. Using a non-invasive, multi-matrix approach, sediment, vegetation and faecal material from lion (Panthera leo) and giraffe (Giraffa camelopardalis) were collected and assessed for the simultaneous quantification of 20 trace elements using an optimised method for Inductively Coupled Plasma-âMass Spectrometry (ICP-MS). Method Linearity was confirmed over an analytical range of 0.1â50 mg/kg for aluminium (Al) and iron (Fe); 0.4â400 ”g/kg for vanadium (V), cobalt (Co), molybdenum (Mo), and cadmium (Cd); 0.5â5 ”g/kg for mercury (Hg); and 1â1 000 ”g/kg for elements arsenic (As), boron (B), barium (Ba), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr) and zinc (Zn). Coefficient of determination (R2) was above 0.99 for all elements. Accuracy (% recovery) and precision (% RSD) of replicate measurements for certified reference material controls fell within 20% of expected value at lower concentrations and 15% at higher concentrations for all elements except Al. Results for instrument and method limit of detections (LOD), method limit of quantification (LOQ) and expanded uncertainty were satisfactory. Preliminary data indicate As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn were present in all matrices evaluated. This raises concerns regarding the combined action of multiple elements at concentrations that can adversely affect ecosystem and wildlife integrity.
âą Sample quantity is reduced due to the power and sensitivity of ICP-MS.
âą The optimised method is capable of detecting differences in trace element concentrations over large orders of magnitude in animal faeces containing different amounts of organic content.
âą The method can be applied to the quantification of essential and potentially toxic elements in faeces across a wide range of terrestrial species.The Department of Science and Technology and National Research foundation SARChI chair of Mammalian Behavioural Ecology and Physiology, South Africa, The University of Pretoria Post-graduate Scholarship Programme and The Tswalu Foundation, South Africa. The National Institute for Science and Technology, Gaithersburg, United States of America is acknowledged for donation of domestic sludge and tomato leaf Certified Reference Materials.http://www.elsevier.com/locate/mexhj2022Mammal Research InstituteZoology and Entomolog
Lagrangian Klein bottles in R^{2n}
It is shown that the n-dimensional Klein bottle admits a Lagrangian embedding
into R^{2n} if and only if n is odd.Comment: V.2 - explicit formula for the Luttinger-type surgery; V.3 - section
3 corrected, section 6 expanded; 6 page
Description and pilot results from a novel method for evaluating return of incidental findings from next-generation sequencing technologies
To develop, operationalize, and pilot test a transparent, reproducible, and evidence informed method to qualify when to report incidental findings from next generation sequencing technologies
Using data mining to identify factors that influence the degree of leg injuries in broilers
University-industry relationships and open innovation: Towards a research agenda
Accepted versio
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
Measurement of the View the tt production cross-section using eÎŒ events with b-tagged jets in pp collisions at âs = 13 TeV with the ATLAS detector
This paper describes a measurement of the inclusive top quark pair production cross-section (ÏttÂŻ) with a data sample of 3.2 fbâ1 of protonâproton collisions at a centre-of-mass energy of âs = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electronâmuon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously ÏttÂŻ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be:
ÏttÂŻ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb,
where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
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