2,709 research outputs found
Absence of xenotropic murine leukaemia virus-related virus in UK patients with chronic fatigue syndrome
No full textBackground: Detection of a retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), has recently been reported in 67% of patients with chronic fatigue syndrome. We have studied a total of 170 samples from chronic fatigue syndrome patients from two UK cohorts and 395 controls for evidence of XMRV infection by looking either for the presence of viral nucleic acids using quantitative PCR (limit of detection <16 viral copies) or for the presence of serological responses using a virus neutralisation assay.
Results: We have not identified XMRV DNA in any samples by PCR (0/299). Some serum samples showed XMRV neutralising activity (26/565) but only one of these positive sera came from a CFS patient. Most of the positive sera were also able to neutralise MLV particles pseudotyped with envelope proteins from other viruses, including vesicular stomatitis virus, indicating significant cross-reactivity in serological responses. Four positive samples were specific for XMRV.
Conclusions: No association between XMRV infection and CFS was observed in the samples tested, either by PCR or serological methodologies. The non-specific neutralisation observed in multiple serum samples suggests that it is unlikely that these responses were elicited by XMRV and highlights the danger of over-estimating XMRV frequency based on serological assays. In spite of this, we believe that the detection of neutralising activity that did not inhibit VSV-G pseudotyped MLV in at least four human serum samples indicates that XMRV infection may occur in the general population, although with currently uncertain outcomes
Draft toxicological profile for JP-5, JP-8, and jet A fuels
No full textA Toxicological Profile for JP-5 and JP-8 was released in 1998. This present edition supersedes any previously released draft or final profile.Chemical manager(s)/author(s): John Risher, Obaid Faroon, ATSDR, Division of Toxicology and Human Health Sciences, Atlanta, GA; Fernando Llados, Lisa Ingerman, Mario Citra, SRC, Inc., North Syracuse, NY
Shock tube study of JP-10 ignition delay time
No full textJP-10 (exo-tetrahydrodicyclopentadiene, C10H16) ignition delay times were measured in a preheated shock tube. The vapor pressures of the JP-10 were measured directly by using a high-precision vacuum gauge, to remedy the difficulty in determining the gaseous concentrations of heavy hydrocarbon fuel arising from the adsorption on the wall in shock tube experiments. The whole variation of pressure and emission of the OH or CH radicals were observed in the ignition process by a pressure transducer and a photomultiplier with a monochromator. The emission of the OH or CH radicals was used to identify the time to ignition. Experiments were performed over the pressure range of 151-556 kPa, temperature range of 1000-2100 K, fuel concentrations of 0.1%-0.55% mole fraction, and stoichiometric ratios of 0.25, 0.5, 1.0 and 2.0. The experimental results show that for the lower and higher temperature ranges, there are different dependency relationships of the ignition time on the temperature and the concentrations of JP-10 and oxygen
Détermination de l'ordre multipolaire de transitions électromagnétiques dans
No full textNous avons modifié un spectromètre magnétique à
électrons du type Siegbahn-Slätis pour déterminer l'ordre
multipolaire des transitions électromagnétiques. A l’aide
de ce dispositif nous avons étudié la nature multipolaire
des quatre transitions suivantes : 8,92 MeV -> 0 dans
11B — 6,49 MeV -> 0 dans 11C - 3,63 MeV -> 0 dans 18O
et 6,88 MeV -> 0 dans 28Si. Ces mesures nous ont permis
d’attribuer Jp = 5/2- au niveau de 8,92 MeV de nB, Jp = 3/2-,
5/2- ou 7/2- au niveau de 6,49 MeV de 11C, Jp = 0+ au
niveau de 3,63 MeV de l8O et de montrer que le niveau
de 6,88 MeV de 28Si est probablement de caractère Jp = 3-
Dynamics of Network Formation Processes in the Co-Author Model
No full textThis article studies the dynamics in the formation processes of a mutual consent network in game theory setting: the Co-Author Model. In this article, a limited observation is applied and analytical results are derived. Then, 2 parameters are varied: the number of individuals in the network and the initial probability of the links in the network in its initial state. A simulation result shows a finding that is consistent with an analytical result for a state of equilibrium while it also shows different possible equilibria.Dynamics, Network, Game Theory, Model,Simulation, Equilibrium, Complexity
An equivalent formulation of the Fan-Raspaud Conjecture and related problems
No full textIn 1994, it was conjectured by Fan and Raspaud that every simple bridgeless cubic graph has three perfect matchings whose intersection is empty. In this paper we answer a question recently proposed by Mkrtchyan and Vardanyan, by giving an equivalent formulation of the Fan-Raspaud Conjecture. We also study a possibly weaker conjecture originally proposed by the first author, which states that in every simple bridgeless cubic graph there exist two perfect matchings such that the complement of their union is a bipartite graph. Here, we show that this conjecture can be equivalently stated using a variant of Petersen-colourings, we prove it for graphs having oddness at most four and we give a natural extension to bridgeless cubic multigraphs and to certain cubic graphs having bridges
Ephemisms as communication vehicle in the Tiv language and literature
No full textThe beauty of Tiv language and literature is achieved when communication or discourse is laced with euphemistic expressions. Euphemisms aid in turning impolite utterances into polite ones. This study, therefore, investigates the communicative potentials of euphemisms in the Tiv language and literature. The study discusses formations of euphemisms, classifies euphemisms and explores the effects of euphemisms. Connotative theory of meaning has been deployed in this study because the interpretation of euphemisms is contextually and connotatively loaded. Methodologically, the author used primary and secondary materials. The author used a participant-observation tool for data collection. Being a native speaker of the Tiv language, the author collected, translated and classified euphemisms. Secondary materials were sourced from textbooks, journal articles, online sources and dictionaries. The following findings were made: euphemisms constitute phrasal or idiomatic synonyms; they beautify or spice our daily communication; they can becloud meanings. This study will benefit preachers, writers, lecturers/teachers, researchers, semanticists, public speakers, politicians and students
Open Access to Peer-Reviewed Research through Author/Institution Self-Archiving: Maximizing Research Impact by Maximizing Online Access
No full textAll refereed journals will soon be available online; most of them already are. This means that anyone will be able to access them from any networked desk-top. The literature will all be interconnected by citation, author, and keyword/subject links, allowing for unheard-of power and ease of access and navigability. Successive drafts of pre-refereeing preprints will be linked to the official refereed draft, as well as to any subsequent corrections, revisions, updates, comments, responses, and underlying empirical databases, all enhancing the self-correctiveness, interactivity and productivity of scholarly and scientific research and communication in remarkable new ways. New scientometric indicators of digital impact are also emerging <http://opcit.eprints.org> to chart the online course of knowledge. But there is still one last frontier to cross before science reaches the optimal and the inevitable: Just as there is no longer any need for research or researchers to be constrained by the access-blocking restrictions of paper distribution, there is no longer any need to be constrained by the impact-blocking financial fire-walls of Subscription/Site-License/Pay-Per-View (S/L/P) tolls for this give-away literature. Its author/researchers have always donated their research reports for free (and its referee/researchers have refereed for free), with the sole goal of maximizing their impact on subsequent research (by accessing the eyes and minds of fellow-researchers, present and future) and hence on society. Generic (OAi-compliant) software is now available free so that institutions can immediately create Eprint Archives in which their authors can self-archive all their refereed papers for free for all forever <http://www.eprints.org/>. These interoperable Open Archives <http://www.openarchives.org> will then be harvested into global, jointly searchable "virtual archives" (e.g., <http://arc.cs.odu.edu/>). "Scholarly Skywriting" in this PostGutenberg Galaxy will be dramatically (and measurably) more interactive and productive, spawning its own new digital metrics of productivity and impact, allowing for an online "embryology of knowledge.
Why hasn't electronic bill presentment and payment taken off?
No full textThe delivery and payment of bills over the Internet could offer many advantages—low processing costs and enhanced marketing opportunities for billers, savings in time and postage for customers. Nevertheless, electronic billing has not found favor with potential users. A lack of coordination among billers and customers, combined with the high fixed costs of the new technology, may help account for the cool reception.Electronic funds transfers ; Electronic commerce ; Technology ; Payment systems
Author Correction: Discovery of fungal surface NADases predominantly present in pathogenic species.
No full textStromland O, Kallio JP, Pschibul A, et al. Author Correction: Discovery of fungal surface NADases predominantly present in pathogenic species. Nature communications. 2021;12(1): 2004
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