110 research outputs found

    Unconventional Approach with the Likelihood of Correlation Matrices

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    Numerical approximations are important research areas for dealing with complicated functional forms. Techniques for developing accurate and efficient calculation of combined likelihood functions in meta-analysis are studied. The first part of the thesis introduces a B-spline approximation for making a parsimonious model in the simplest case(2-dimensional case) of correlation structure. Inference about the correlation between vitamin C intake & vitamin C serum level is developed by using likelihood intervals and the MLE, along with comparison with conventional methods. The second part studies a multivariate numerical integration method for developing a better approximation of the likelihood for correlation matrices. Analyses for (1) intercorrelations among Math, Spatial and Verbal scores in an SAT exam and (2) intercorrelations among Cognitive Anxiety, Somatic Anxiety and Self Confidence from Competitive State Anxiety Inventory (CSAI-2) are explored. Algorithms to evaluate likelihood and to find the MLE is developed. Comparison with two conventional methods (joint asymptotic weighted average method & marginal asymptotic weighted average method) is shown

    Generating bounded solutions for multi-demand multidimensional knapsack problems: a guide for operations research practitioners

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    A generalization of the 0-1 knapsack problem that is hard-to-solve both theoretically (NP-hard) and in practice is the multi-demand multidimensional knapsack problem (MDMKP). Solving an MDMKP can be difficult because of its conflicting knapsack and demand constraints. Approximate solution approaches provide no guarantees on solution quality. Recently, with the use of classification trees, MDMKPs were partitioned into three general categories based on their expected performance using the integer programming option of the CPLEX® software package on a standard PC: Category A—relatively easy to solve, Category B—somewhat difficult to solve, and Category C—difficult to solve. However, no solution methods were associated with these categories. The primary contribution of this article is that it demonstrates, customized to each category, how general-purpose integer programming software (CPLEX in this case) can be iteratively used to efficiently generate bounded solutions for MDMKPs. Specifically, the simple sequential increasing tolerance (SSIT) methodology will iteratively use CPLEX with loosening tolerances to efficiently generate these bounded solutions. The real strength of this approach is that the SSIT methodology is customized based on the particular category (A, B, or C) of the MDMKP instance being solved. This methodology is easy for practitioners to use because it requires no time-consuming effort of coding problem specific-algorithms. Statistical analyses will compare the SSIT results to a single-pass execution of CPLEX in terms of execution time and solution quality

    Acidic pH shock induces the expressions of a wide range of stress-response genes

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    <p>Abstract</p> <p>Background</p> <p>Environmental signals usually enhance secondary metabolite production in <it>Streptomycetes </it>by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in <it>Streptomyces </it>strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in <it>S. coelicolor </it>A3(2).</p> <p>Results</p> <p>According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of <it>sigH </it>(heat shock), <it>sigR </it>(oxidative stress), <it>sigB </it>(osmotic shock), and <it>hrdD </it>that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of <it>hspR </it>was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall.</p> <p>Conclusion</p> <p>From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.</p

    Antigenic diversity of Theileria major piroplasm surface protein gene in Jeju black cattle

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    Piroplasms are tick-transmitted, intracellular, hemoprotozoan parasites that cause anorexia, fever, anemia, and icterus. Theileriosis is caused by Theileria sergenti and causes major economic losses in grazing cattle in Japan and Korea. In May 2003, we examined the antigenic diversity of the major piroplasm surface protein (MPSP) gene in 35 healthy Jeju black cattle that were born and raised at the National Institute of Subtropical Agriculture. On microscopic examination of Giemsa-stained blood smears, 9 of 35 cattle had intra-erythrocytic piroplasms. Hematological data were within normal range for all 35 cattle. Amplification of DNA from all blood samples using universal MPSP gene primers showed mixed infections with C, I, and B type Theileria spp. Type C was identified in 20 of 35 blood samples, and type B was identified in 17 samples. Allelic variation was seen in type B

    Cooccurrence of Metastatic Papillary Thyroid Carcinoma and Salmonella

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    Cervical lymph node metastasis is common in patients with papillary thyroid carcinoma (PTC). Salmonella species are rarely reported as causative agents in focal infections of the head and neck. The cooccurrence of lymph node metastasis from PTC and a bacterial infection is rare. This report describes a 76-year-old woman with a cervical lymph node metastasis from PTC and Salmonella infection of the same lymph node. The patient presented with painful swelling in her left lateral neck region for 15 days, and neck ultrasonography and computed tomography showed a cystic mass along left levels II–IV. The cystic mass was suspected of being a metastatic lymph node; modified radical neck dissection was performed. Histopathological examination confirmed the presence of PTC in the resected node and laboratory examination of the combined abscess cavity confirmed the presence of Salmonella Typhi. Following antibiotic sensitivity testing of the cultured Salmonella Typhi, she was treated with proper antibiotics. Cystic lesions in lymph nodes with metastatic cancer may indicate the presence of cooccurring bacterial infection. Thus, culturing of specimen can be option to make accurate diagnosis and to provide proper postoperative management

    A Dispermic Chimera with Mixed Field Blood Group B and Mosaic 46,XY/47,XYY Karyotype

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    Chimerism in humans is a rare phenomenon often initially identified in the resolution of an ABO blood type discrepancy. We report a dispermic chimera who presented with mixed field in his B antigen typing that might have been mistaken for the B3 subtype. The propositus is a healthy Korean male blood donor. Neither his clinical history nor initial molecular investigation of his ABO gene explained his mixed field agglutination with murine anti-B. Chimerism was suspected, and 9 short tandem repeat (STR) loci were analyzed on DNA extracted from blood, buccal swabs, and hair from this donor and on DNA isolated from peripheral blood lymphocytes from his parents. The propositus' red blood cells demonstrated mixed field agglutination with anti-B. Exon 6 and 7 and flanking intronic regions of his ABO gene were sequenced and revealed an O01/O02 genotype. B allele haplotype-specific PCR, along with exon 6 and 7 cloning and sequencing demonstrated a third ABO allele, B101. Four STR loci demonstrated a pattern consistent with a double paternal chromosome contribution in the propositus, thus confirming chimerism. His karyotype revealed a mosaic pattern: 32/50 metaphases were 46,XY and 18/50 metaphases demonstrated 47,XYY

    Time Sequence of Airway Remodeling in a Mouse Model of Chronic Asthma: the Relation with Airway Hyperresponsiveness

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    During the course of establishing an animal model of chronic asthma, we tried to elucidate the time sequence of airway hyperresponsiveness (AHR), airway inflammation, airway remodeling, and associated cytokines. Seven-week-old female BALB/c mice were studied as a chronic asthma model using ovalbumin (OVA). After sensitization, mice were exposed twice weekly to aerosolized OVA, and were divided into three groups depending on the duration of 4 weeks, 8 weeks, and 12 weeks. At each time point, airway responsiveness, inflammatory cells, cytokines in bronchoalveolar lavage fluids (BALF), serum OVA-specific IgE, IgG1, IgG2a, and histological examination were carried out. AHR to methacholine, increased levels of OVA-specific IgG1 and IgG2a, and goblet cell hyperplasia were continuously sustained at each time point of weeks. In contrast, we observed a time-dependent decrease in serum OVA-specific IgE, BALF eosinophils, BALF cytokines such as IL-13, transforming growth factor-beta1, and a time-dependent increase in BALF promatrix metalloproteinase-9 and peribronchial fibrosis. In this OVA-induced chronic asthma model, we observed airway remodelings as well as various cytokines and inflammatory cells being involved in different time-dependent manners. However, increased airway fibrosis did not directly correlate with a further increase in airway hyperresponsiveness

    Environmental assessment of advanced partitioning, transmutation, and disposal based on long-term risk-informed regulation: PyroGreen

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    The safety of spent nuclear fuel (SNF) storage has become one of the major issues of nuclear power plant operation. Direct disposal and recycling have both been criticized by the general public due to uncertainty of the long-term safety of SNF and high level waste (HLW) repositories. To meet the goal of sustainable nuclear energy, an innovative recycling approach using pyrochemical partitioning and transmutation termed PyroGreen, which is a conceptually advanced pyrochemical partitioning flowsheet, has been proposed to eliminate the need for HLW repositories. From the previous partitioning process, PyroGreen uses a combination of hull electrorefining, reductive extraction, and selective oxidation to further decontaminate SNF and HLW into low- and intermediate level waste (LILW). This paper examines the long-term environmental performance of a geological repository that houses all of the final PyroGreen-produced wastes while describing the feasibility of PyroGreen partitioning and transmutation. The final PyroGreen wastes are evaluated based on long-term risk-informed criteria: alpha-emitting isotope concentration, heat generation, and radiation dose in the surrounding biosphere. All final wastes arising from PyroGreen are to be disposed of in a geological repository at an intermediate depth, in compliance with new International Atomic Energy Agency Safety Guide for LILW. Migration assessment found that several long-lived fission products including C-14, Cl-36, Se-79, Sn-125, and I-129 dominate the long-term dose rate, whereas transuranic elements govern the risk of an inadvertent human intrusion scenario. In order to turn entire batches of SNF from 24 light water reactors with 1000 MWe with a design life of 40 years into LILW, we determined and compared the required decontamination factors of the key radionuclides for between intermediate-depth and near-surface disposal. (C) 2012 Elsevier Ltd. All rights reservedclose3
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