3,146 research outputs found

    The Jammed Phase of the Biham-Middleton-Levine Traffic Model

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    Initially a car is placed with probability p at each site of the two-dimensional integer lattice. Each car is equally likely to be East-facing or North-facing, and different sites receive independent assignments. At odd time steps, each North-facing car moves one unit North if there is a vacant site for it to move into. At even time steps, East-facing cars move East in the same way. We prove that when p is sufficiently close to 1 traffic is jammed, in the sense that no car moves infinitely many times. The result extends to several variant settings, including a model with cars moving at random times, and higher dimensions.Comment: 15 pages, 5 figures; revised journal versio

    Total photoionization cross sections of atomic oxygen from threshold to 44.3A

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    The relative cross section of atomic oxygen for the production of singly charged ions has been remeasured in more detail and extended to cover the wavelength range 44.3 to 910.5 A by the use of synchrotron radiation. In addition, the contribution of multiple ionization to the cross sections has been measured allowing total photoionization cross sections to be obtained below 250 A. The results have been made absolute by normalization to previously measured data. The use of synchrotron radiation has enabled measurements of the continuum cross section to be made between the numerous autoionizing resonances that occur near the ionization thresholds. This in turn has allowed a more critical comparison of the various theoretical estimates of the cross section to be made. The series of autoionizing resonances leading to the 4-P state of the oxygen ion have been observed for the first time in an ionization type experiment and their positions compared with both theory and previous photographic recordings

    Hepatitis B infection in Malta : a retrospective cross sectional study

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    Chronic Hepatitis B infection can lead to significant morbidity and mortality. Case notes of patients who tested positive for HBsAg between 1st Dec 2007 and 29th October 2009 were reviewed (n=197) . The results show that 2/3 (65%) of the study population were male and that HBV infection was detected across all age groups. About ¼ (25.4%) of the study group were foreigners. 79% of Maltese patients testing postive did not have any identifiable risk factors documented in their case notes for acquiring HBV. In more than 60% of patients who tested positive further assessment to determine suitability for treatment was not performed and only 6.6 % of the study population received treatment for HBV.peer-reviewe

    Limits and Confidence Intervals in the Presence of Nuisance Parameters

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    We study the frequentist properties of confidence intervals computed by the method known to statisticians as the Profile Likelihood. It is seen that the coverage of these intervals is surprisingly good over a wide range of possible parameter values for important classes of problems, in particular whenever there are additional nuisance parameters with statistical or systematic errors. Programs are available for calculating these intervals.Comment: 6 figure

    Total and dissociative photoionization cross sections of N2 from threshold to 107 eV

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    The absolute cross sections for the production of N(+) and N2(+) were measured from the dissociative ionization threshold of 115 A. In addition, the absolute photoabsorption and photoionization cross sections were tabulated between 114 and 796 A. The ionization efficiencies were also given at several discrete wave lengths between 660 and 790 A. The production of N(+) fragment ions are discussed in terms of the doubly excited N2(+) states with binding energies in the range of 24 to 44 eV

    Using Networks To Understand Medical Data: The Case of Class III Malocclusions

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    A system of elements that interact or regulate each other can be represented by a mathematical object called a network. While network analysis has been successfully applied to high-throughput biological systems, less has been done regarding their application in more applied fields of medicine; here we show an application based on standard medical diagnostic data. We apply network analysis to Class III malocclusion, one of the most difficult to understand and treat orofacial anomaly. We hypothesize that different interactions of the skeletal components can contribute to pathological disequilibrium; in order to test this hypothesis, we apply network analysis to 532 Class III young female patients. The topology of the Class III malocclusion obtained by network analysis shows a strong co-occurrence of abnormal skeletal features. The pattern of these occurrences influences the vertical and horizontal balance of disharmony in skeletal form and position. Patients with more unbalanced orthodontic phenotypes show preponderance of the pathological skeletal nodes and minor relevance of adaptive dentoalveolar equilibrating nodes. Furthermore, by applying Power Graphs analysis we identify some functional modules among orthodontic nodes. These modules correspond to groups of tightly inter-related features and presumably constitute the key regulators of plasticity and the sites of unbalance of the growing dentofacial Class III system. The data of the present study show that, in their most basic abstraction level, the orofacial characteristics can be represented as graphs using nodes to represent orthodontic characteristics, and edges to represent their various types of interactions. The applications of this mathematical model could improve the interpretation of the quantitative, patient-specific information, and help to better targeting therapy. Last but not least, the methodology we have applied in analyzing orthodontic features can be applied easily to other fields of the medical science.</p

    111. Temporary Protection

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    The authors argue for a humane and dignified conceptualization of temporary protection, in which "refugee containment" is emphatically rejected. Mechanisms to respond to refugee vulnerabilities, safeguard the family, preserve forms of social organization, and meaningfully involve refugees in constructive interaction with their host communities are outlined. A maximum duration of five years is proposed, subject both to early adjustment to meet special needs and a firm commitment to ensure a permanent solution at the expiration of that timefame. The necessity of mandated repatriation in safety and dignity is acknowledged, though proposals are advanced to maximize voluntary repatriation as a preferred response. This is a substantially abbreviated version of the authors' original work. Please refer to the notice at the end of this section if you are interested in obtaining a full copy of the paper, which is expected to be published in mid-1996
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