88 research outputs found

    Dynamic and Multi-functional Labeling Schemes

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    We investigate labeling schemes supporting adjacency, ancestry, sibling, and connectivity queries in forests. In the course of more than 20 years, the existence of logn+O(loglog)\log n + O(\log \log) labeling schemes supporting each of these functions was proven, with the most recent being ancestry [Fraigniaud and Korman, STOC '10]. Several multi-functional labeling schemes also enjoy lower or upper bounds of logn+Ω(loglogn)\log n + \Omega(\log \log n) or logn+O(loglogn)\log n + O(\log \log n) respectively. Notably an upper bound of logn+5loglogn\log n + 5\log \log n for adjacency+siblings and a lower bound of logn+loglogn\log n + \log \log n for each of the functions siblings, ancestry, and connectivity [Alstrup et al., SODA '03]. We improve the constants hidden in the OO-notation. In particular we show a logn+2loglogn\log n + 2\log \log n lower bound for connectivity+ancestry and connectivity+siblings, as well as an upper bound of logn+3loglogn+O(logloglogn)\log n + 3\log \log n + O(\log \log \log n) for connectivity+adjacency+siblings by altering existing methods. In the context of dynamic labeling schemes it is known that ancestry requires Ω(n)\Omega(n) bits [Cohen, et al. PODS '02]. In contrast, we show upper and lower bounds on the label size for adjacency, siblings, and connectivity of 2logn2\log n bits, and 3logn3 \log n to support all three functions. There exist efficient adjacency labeling schemes for planar, bounded treewidth, bounded arboricity and interval graphs. In a dynamic setting, we show a lower bound of Ω(n)\Omega(n) for each of those families.Comment: 17 pages, 5 figure

    Aseptic Meningitis in Children: Analysis of 506 Cases

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    BACKGROUND: Non-polio human enteroviruses are the leading cause of aseptic meningitis in children. The role of enterovirus PCR for diagnosis and management of aseptic meningitis has not been fully explored. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study was conducted to determine the epidemiological, clinical, and laboratory characteristics of aseptic meningitis and to evaluate the role of enterovirus PCR for the diagnosis and management of this clinical entity. The medical records of children who had as discharge diagnosis aseptic or viral meningitis were reviewed. A total of 506 children, median age 5 years, were identified. The annual incidence rate was estimated to be 17/100,000 children less than 14 years of age. Most of the cases occurred during summer (38%) and autumn (24%). The dominant clinical symptoms were fever (98%), headache (94%) and vomiting (67%). Neck stiffness was noted in 60%, and irritation in 46% of the patients. The median number of CSF cell count was 201/mm(3) with polymorphonuclear predominance (>50%) in 58.3% of the cases. Enterovirus RNA was detected in CSF in 47 of 96 (48.9%) children tested. Children with positive enterovirus PCR had shorter hospitalization stay as compared to children who had negative PCR or to children who were not tested (P = 0.01). There were no serious complications or deaths. CONCLUSIONS: Enteroviruses accounted for approximately one half of cases of aseptic meningitis. PCR may reduce the length of hospitalization and plays important role in the diagnosis and management of children with aseptic meningitis

    A Retrospective Overview of Enterovirus Infection Diagnosis and Molecular Epidemiology in the Public Hospitals of Marseille, France (1985–2005)

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    Human enteroviruses (HEV) are frequent human pathogens and, associated in particular with large outbreaks of aseptic meningitis. Here, we have compiled a database of clinical HEV isolates from the Public Hospitals of Marseille, from 1985 to 2005. Amongst 654 isolates that could be characterized by complete sequencing of the VP1 gene, 98% belonged to species HEV-B; the most frequently isolated serotypes were Echovirus E30, E11, E7, E6 and E4. The high incidence of E30 and the recent emergence of E13 are consistent with reports worldwide and peak HEV isolation occurred mostly in the late spring and summer months. The proportion of echoviruses has decreased across the years, while that of coxsackieviruses has increased. Stool (the most frequent sample type) allowed detection of all identified serotypes. MRC5 (Human lung fibroblasts) cell line was the most conducive cell line for HEV isolation (84.9% of 10 most common serotype isolates, 96.3% in association with BGM (Buffalo green monkey kidney cells)). Previous seroneutralization-based serotype identification demonstrated 55.4% accuracy when compared with molecular VP1 analysis. Our analysis of a large number of clinical strains over 20 years reinforced the validity of VP1 serotyping and showed that comparative p-distance scores can be coupled with phylogenetic analysis to provide non-ambiguous serotype identification. Phylogenetic analysis in the VP1, 2C and 3D regions also provided evidence for recombination events amongst clinical isolates. In particular, it identified isolates with dissimilar VP1 but almost identical nonstructural regions

    Identification of Resource Use and Associated Costs for Viral Meningitis

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    ABSTRACT Purpose: This study involved identifying resource use and assigning monetary value to the diagnostic work-up and management of viral meningitis. Methodology: Using a previously established decision analytic framework, various resources were identified as part of routine management of viral meningitis. Secondary database analyses were used to quantify resources and assign a monetary value as a part of routine management of viral meningitis requiring use of the resource units identified in the decision analytic framework. Discharge data sources from the states of California, Florida, and Illinois, and Medicaid data sources from the state of Pennsylvania, were used for the purpose of analysis. Principal Findings: Physician visits, emergency room visits, hospital admissions, procedures, and medications were identified as the major resources used. Lumbar punctures, CT scans, and antibiotics were identified as the major procedures and medications utilized. No significant difference was found in the major resources used between the states' discharge data and the Medicaid data sources. The mean total charges for patient admissions with CT scans were significantly higher than for patient admissions without CT scans (11,531.80vs.11,531.80 vs. 7,841.30, P<0.05). The mean lengths of stay for patients with CT scan were significantly higher than for patient admissions without CT scans (4.71 days vs. 3.88 days, P<0.05). The patient readmission rate was 10.7 percent, while the readmission rate for episodes with more than one hospitalization was 11.1 percent. The mean charge associated with readmission was $12,200

    Neurotropic virus infections as the cause of immediate and delayed neuropathology

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