107,774 research outputs found
Rapid identification of Rhodococcus equi by a PCR assay targeting the choE gene
No full textThe actinomycete Rhodococcus equi is an important pathogen of horses and an emerging opportunistic pathogen of humans. Identification of R. equi by classical bacteriological techniques is sometimes difficult, and misclassification of an isolate is not uncommon. We report here on a specific PCR assay for the rapid and reliable identification of R. equi. It is based on the amplification of a fragment of the choE gene encoding cholesterol oxidase. The choE-based PCR was assessed by using a panel of strains comprising 132 isolates from different sources and of different geographical origins, all initially identified biochemically as R. equi, and 30 isolates of representative non-R. equi actinomycete species, including cholesterol oxidase producers. The expected 959-bp amplicon was observed only with R. equi isolates, as confirmed by sequencing of a variable region of the 16S RNA gene from a random sample of 20 PCR-positive isolates. All R. equi isolates gave a positive choE-based PCR result, which correlated with a high degree of conservation of the choE gene. Three of the 132 strains originally identified as R. equi were negative for the choE gene, and subsequent analysis of their 16S RNA gene sequences confirmed that they belonged to other bacterial species (Dietzia maris, Mycobacterium peregrinum, and Staphylococcus epidermidis). All non-R. equi isolates were negative by the choE-based PCR. ATCC 21387, the only known isolate of Brevibacterium sterolicum, gave a 959-bp amplicon whose DNA sequence was virtually identical to that of R. equi choE. Comparison of the 16S RNA genes indicated that ATCC 21387 should be considered an R. equi isolate
Internally controlled real-time PCR method for quantitative species-specific detection and vapA genotyping of Rhodococcus equi
No full textWe developed a novel quantitative real-time PCR (Q-PCR) method for the soil actinomycete Rhodococcus equi, an important horse pathogen and emerging human pathogen. Species-specific quantification was achieved by targeting the chromosomal monocopy gene choE, universally conserved in R. equi. The choE Q-PCR included an internal amplification control (IAC) for identification of false negatives. A second Q-PCR targeted the virulence plasmid gene vapA, carried by most horse isolates but infrequently found in isolates from other sources. The choE-IAC and vapA assays were 100% sensitive and specific as determined using 178 R. equi isolates, 77 nontarget bacteria, and a panel of 60 R. equi isolates with known vapA+ and vapA-negative (including vapB+) plasmid genotypes. The vapA+ frequency among isolate types was as follows: horse, 85%; human, 20%; bovine and pig, 0%; others, 27%. The choE-IAC Q-PCR could detect up to one genome equivalent using R. equi DNA or 100 bacteria/ml using DNA extracted from artificially contaminated horse bronchoalveolar lavage (BAL) fluid. Quantification was linear over a 6-log dynamic range down to approximately 10 target molecules (or 1,000 CFU/ml BAL fluid) with PCR efficiency E of >0.94. The vapA assay had similar performance but appeared unsuitable for accurate (vapA+) R. equi quantification due to variability in target gene or plasmid copy number (1 to 9). The dual-reaction Q-PCR system here reported offers a useful tool to both medical and veterinary diagnostic laboratories for the quantitative detection of R. equi and (optional) vapA+ "horse-pathogenic" genotype determination
A methodology for accurate and redundancy-free business requirements description using ontology
No full textData deluge and changing business environment are considered to be serious in that data in corporate information systems are too conveniently and frequently replicated for companies to make decisions properly. Inaccurate and redundant data would induce erroneous decision making which bases on error-infectious information systems. We report that most of inaccuracy and redundancy can be effectively removed from the very start of information system development using business description. Over the last few decades, a few efforts to make business descriptions correctly have been directed toward ontology for business requirements elicitation. However, due to excessive reliance on stale knowledge of past documents, most ontology based systems have failed to formulate appropriate business requirements for up-to-date business circumstances. We propose a new enhanced method which can formulate a flexible business description on the basis of local domain ontology as well as prior knowledge bases. In addition to utilizing ontology as business requirements description, our method focuses on accuracy and redundancy in business requirements description. To evaluate the methodology, we devised a new system of ontology integration for business requirements description
Disparity estimation using a region-dividing technique and energy-based regularization
No full textA two-stage algorithm is proposed for locating smooth and detailed disparity vector fields in a stereo image pair. The algorithm consists of hierarchical disparity estimation using a region-dividing technique and edge-preserving regularization. The hierarchical region-dividing disparity estimation increases the efficiency and reliability of the estimation process. At the second stage, the vector fields are regularized with an energy model that produces smooth fields while preserving discontinuities resulting from object boundaries. The minimization problem is addressed by solving a corresponding partial differential equation using a finite-difference method. Experiments show that the proposed algorithm provides accurate and spatially correlated dispartly vector fields in various types of stereo images, even in the case of images with large displacements. © 2004 Society of Photo-Optical Instrumentation Engineers
Mod 2 normal numbers and skew products
No full textLet E be an interval in the unit interval [0, 1). For each x is an element of [0, 1) define d(n)(x) is an element of {0, 1} by d(n)(x) := Sigma(i=1)(n) 1(E)({2(i-1)x}) (mod 2), where {t} is the fractional part of t. Then x is called a normal number mod 2 with respect to E if N-1 Sigma(n=1)(N) d(n)(x) converges to 1/2. It is shown that for any interval E not equal (1/6,5/6) a.e. x is a normal number mod 2 with respect to E. For E = (1/6,5/6) it is proved that N-1 Sigma(n=1)(N) d(n) (x) converges a.e. and the limit equals 1/3 or 2/3 depending on x
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Supplementary Material: Integrating Climate Change and Land Use Impacts to Explore Forest Conservation Policy
No full text<p>Supplementary files for Hyeyeong Choe and James H. Thorne, Integrating Climate Change and Land Use Impacts to Explore Forest Conservation Policy. <em>Forests </em><strong>2017</strong>, <em>8</em>, 321. Table S1: A list of climate vulnerable species in this study, Figure S1: Recent forest loss percentage versus forest in 2000 by administrative district, Figure S2: Proportion of forest for each district in current time and in each scenario by 2050, Supplementary File S1: 16 GIS raster layers for the spatial results of this study, Table S2: The average species richness value of each forest category between scenarios, Table S3: Forest Conversion Projection in Each Policy Scenario.</p>
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Rückkehr- und Bleibeperspektiven koreanischer Arbeitsmigranten in der Bundesrepublik Deutschland
No full textChoe J-H, Daheim H. Rückkehr- und Bleibeperspektiven koreanischer Arbeitsmigranten in der Bundesrepublik Deutschland. Beiträge zur Gesellschaftsforschung, 5. Frankfurt a.Main: Lang; 1987.Die Problematik von Bleiben oder Rückkehr wird am Fall einer hinsichtlich Herkunft, Schulbildung und Verhältnissen im Heimatland besonderen Gruppe von Arbeitsmigranten untersucht: Familien von koreanischen Krankenschwestern und Arbeitern. Ihre Perspektiven und Handlungsstrategien werden beschrieben und deren strukturelle Bedingungen aufgezeigt. Die Untersuchung stützt sich in ihrem empirischen Teil auf 18 Einzelinterviews und drei Gruppengespräche mit in der Bundesrepublik Deutschland seit Anfang der 60er Jahre lebenden Koreanern und Koreanerinnen. (IAB2
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