14,268 research outputs found

    Mycoplasma Pneumoniae infections in the Maltese Islands

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    Mycoplasma pneumoniae is a free living micro-organism which is classified in the family Mycoplasmataceae. It is primarily a human respiratory pathogen and the infection may vary from a mild pharyngitis to a pneumonia. M. pneumoniae infections are usually endemic in the community but periodic epidemics can also occur. These micro-organisms are sensitive to specific antibiotics such as tetracycline and erythromycin and a laboratory diagnosis using rapid methods is therefore important. Studies were carried out at the Virology Laboratory, St. Luke’s Hospital involving 1,022 cases during the period 1995 to 1998. These were examined for specific anti-mycoplasmal IgM antibodies using an enzyme immunoassay (EIA) technique. One hundred and forty samples or 13.7% were found to be reactive. Compared to the traditional cultural methods, EIA techniques are very rapid laboratory diagnostic methods, the result being communicated to the clinician within a few hours. The differential diagnosis of the particular case can thus be resolved quickly and appropriate antibiotic therapy instituted without much delay for the maximum benefit to the patient.peer-reviewe

    Microscopic theory of pion production and sidewards flow in heavy ion collisions

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    Nuclear collisions from 0.3 to 2 GeV/nucleon are studied in a microscopic theory based on Vlasov's self-consistent mean field and Uehling-Uhlenbeck's two-body collision term which respects the Pauli principle. The theory explains simultaneously the observed collective flow and the pion multiplicity and gives their dependence on the nuclear equation of state

    Rapidity dependence of entropy production in proton- and nucleus-induced reactions on heavy nuclei

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    The entropy of hot nuclear systems is deduced from the mass distribution of fragments emitted from high energy proton- and nucleus-induced reactions via a quantum statistical model. It is found that the entropy per baryon, S/A, of intermediate rapidity ("participant") fragments is higher than the entropy of target rapidity ("spectator") fragments. The spectator fragments exhibit S/A values of ≅ 1.8 independent of the projectile energy from 30 MeV/nucleon up to 350 GeV. This value of the entropy coincides with the entropy at which nuclear matter becomes unbound

    Optimal Decompositions of Barely Separable States

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    Two families of bipartite mixed quantum states are studied for which it is proved that the number of members in the optimal-decomposition ensemble --- the ensemble realizing the entanglement of formation --- is greater than the rank of the mixed state. We find examples for which the number of states in this optimal ensemble can be larger than the rank by an arbitrarily large factor. In one case the proof relies on the fact that the partial transpose of the mixed state has zero eigenvalues; in the other case the result arises from the properties of product bases that are completable only by embedding in a larger Hilbert space.Comment: 14 Pages (RevTeX), 1 figure (eps). Submitted to the special issue of the J. Mod. Opt. V2: Change in terminology from "ensemble length" to "ensemble cardinality

    On the Detectability of Oxygen X-ray Fluorescence and its Use as a Solar Photospheric Abundance Diagnostic

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    Monte Carlo calculations of the O Kalpha line fluoresced by coronal X-rays and emitted just above the temperature minimum region of the solar atmosphere have been employed to investigate the use of this feature as an abundance diagnostic. While quite weak, we estimate line equivalent widths in the range 0.02-0.2 AA, depending on the X-ray plasma temperature. The line remains essentially uncontaminated by blends for coronal temperatures T =< 3e6 K and should be quite observable, with a flux >~ 2 ph/s/arcmin^2. Model calculations for solar chemical mixtures with an O abundance adjusted up and down by a factor of 2 indicate 35-60% changes in O Kalpha line equivalent width, providing a potentially useful O abundance diagnostic. Sensitivity of equivalent width to differences between recently recommended chemical compositions with ``high'' and ``low'' complements of the CNO trio important for interpreting helioseismological observations is less accute, amounting to 20-26% at coronal temperatures T ~< 2e6 K. While still feasible for discriminating between these two mixtures, uncertainties in measured line equivalent widths and in the models used for interpretation would need to be significantly less than 20%. Provided a sensitive X-ray spectrometer with resolving power >= 1000 and suitably well-behaved instrumental profile can be built, X-ray fluorescence presents a viable means for resolving the solar ``oxygen crisis''.Comment: To appear in the Astrophysical Journa

    On the role of depletive tests. a review analysis

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    An overview of the diagnostic role of depletion tests for staging Meniere’s disease, especially in the first phase of the disease, is reported. Pros and cons, as well reliability and specificity of this diagnostic procedure is thoroughly analysed

    An artificial neural network approach for modelling the ward atmosphere in a medical unit

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    Artificial neural networks (ANNs) have been developed, implemented and tested on the basis of a four-year-long experimental data set, with the aim of analyzing the performance and clinical outcome of an existing medical ward, and predicting the effects that possible readjustments and/or interventions on the structure may produce on it. Advantages of the ANN technique over more traditional mathematical models are twofold: on one hand, this approach deals quite naturally with a large number of parameters/variables, and also allows to identify those variables which do not play a crucial role in the system dynamics; on the other hand, the implemented ANN can be more easily used by a staff of non-mathematicians in the unit, as an on-site predictive tool. As such, the ANN model is particularly suitable for the case study. The predictions from the ANN technique are then compared and contrasted with those obtained from a generalized kinetic approach previously proposed and tested by the authors. The comparison on the two case periods shows the ANN predictions to be somewhat closer to the experimental values. However, the mean deviations and the analysis of the statistical coefficients over a span of multiple years suggest the kinetic model to be more reliable in the long run, i.e., its predictions can be considered as acceptable even on periods that are quite far away from the two case periods over which the many parameters of the model had been optimized. The approach under study, referring to paradigms and methods of physical and mathematical models integrated with psychosocial sciences, has good chances of gaining the attention of the scientific community in both areas, and hence of eventually obtaining wider diffusion and generalization.

    Are there plasminos in superconductors?

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    Hot and/or dense, normal-conducting systems of relativistic fermions exhibit a particular collective excitation, the so-called plasmino. We compute the one-loop self-energy, the dispersion relation and the spectral density for fermions interacting via attractive boson exchange. It is shown that plasminos also exist in superconductors.Comment: 15 pages, 14 figures, revte
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