3,752 research outputs found

    MAJORIZATION OF MATRICES

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    It is shown that under certain conditions the column majorization of matrices is reversed for the column majorization of their corresponding Moore-Penrose inverses and preserved for the column majorization of their powers. The condition for column majorization of block matrices is determined

    Sero Diagnosis of Tuberculosis in Children Using Two ELISA Kits

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    The diagnosis of childhood tuberculosis is based on circumstantial evidence in the absence of a gold standard in the majority of cases. Sero-diagnosis offers scope for an early diagnosis in a variety of clinical conditions and is simple to perform. A number of mycobacterial antigens have been used for antibody detection assays and several are available as kits in the market. This study was done to evaluate the value of antibody detection kits (ELISA) against the A60 antigen and 38kDa antigen of Mycobacterium tuberculosis in the diagnosis of childhood tuberculosis at the outpatient department of the Institute of Social Paediatrics, Government Stanley Hospital in collaboration with Tuberculosis Research Centre, Chennai. Thirty five children with pulmonary tuberculosis, 7 with TB lymphadenitis and 22 healthy controls were studied. In addition to routine investigations including gastric lavage for AFB culture, serum antibodies against the A60 and 38kDa antigens were assayed using commercially available ELISA kits. With A60, IgM serum levels were positive in 74% of pulmonary TB cases, 57% of TB lymphadenitis cases and 50% of controls. A60 IgG was positive in 17% of pulmonary TB, 86% of TB lymphadenitis and 14% of controls. The 38 kDa IgG antibody was positive in 37% of pulmonary and 86% of TB lymphadenitis cases and 27% of controls. Among 10 culture confirmed cases, A60 IgM was positive in 8, A60 IgG in 3 and 38kDa IgG in 5 patients. The sensitivity of the tests ranged between 29% and 71% and specificity between 50% and 86%. Although the numbers are small, the results suggest that serodiagnosis using the currently available antigens of M. tuberculosis is unlikely to be a confirmatory test for tuberculosis in children

    On tuning passive black-box macromodels of LTI systems via adaptive weighting

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    This paper discusses various approaches for tuning the accuracy of rational macromodels obtained via black-box identification or approximation of sampled frequency responses of some unknown Linear and Time-Invariant system. Main emphasis is on embedding into the model extraction process some information on the nominal terminations that will be connected to the model during normal operation, so that the corresponding accuracy is optimized. This goal is achieved through an optimization based on a suitably defined cost function, which embeds frequency-dependent weights that are adaptively refined during the model construction. A similar procedure is applied in a postprocessing step for enforcing model passivity. The advantages of proposed algorithm are illustrated on a few application examples related to power distribution networks in electronic system

    Some results on the distance r-b-coloring in graphs

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    Given a positive integer r, two vertices u, v ∈ V (G) are r- independent if d(u, v) > r. A partition of V (G) into r-independent sets is called a distance r-coloring. A study of distance r-coloring and distance r-b-coloring concepts are studied in this paper.Publisher's Versio

    Electron-impact excitation of X 1Sigma<sub>g</sub><sup>+</sup>(v[double-prime]=0) to the a[double-prime] 1Sigma<sub>g</sub><sup>+</sup>, b 1Piu, c3 1Piu, o3 1Piu, b[prime] 1Sigma<sub>u</sub><sup>+</sup>, c<sub>4</sub><sup>[prime]</sup> 1Sigma<sub>u</sub><sup>+</sup>, G 3Piu, and F 3Piu states of molecular nitrogen

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    Measurements of differential cross sections (DCSs) for electron-impact excitation of the a[double-prime] 1Sigmag+, b 1Piu, c3 1Piu, o3 1Piu, b[prime] 1Sigmau+, c4[prime] 1Sigmau+, G 3Piu, and F 3Piu states in N2 from the X 1Sigmag+(v[double-prime]=0) ground level are presented. The DCSs were obtained from energy-loss spectra in the region of 12 to 13.82 eV measured at incident energies of 17.5, 20, 30, 50, and 100 eV and for scattering angles ranging from 2° to 130°. The analysis of the spectra follows a different algorithm from that employed in a previous study of N2 for the valence states [Khakoo et al. Phys. Rev. A 71, 062703 (2005)], since the 1Piu and 1Sigmau+ states form strongly interacting Rydberg-valence series. The results are compared with existing data

    Development and characterization of a fibroblastic-like cell line from caudal fin of the red-line torpedo, Puntius denisonii (Day) (Teleostei: Cyprinidae)

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    A fibroblastic-like cell line was established from the ornamental ¢sh, red-line torpedo (Puntius denisonii). The red-line torpedo fin (RTF) cell line is being maintained in Leibovitz’s L-15 mediumsupplementedwith 10% fetal bovine serum (FBS) for over 1year at 28 1C on a continuous basis in normal atmosphere. The growth rate of RTF cells increased as the FBS proportion increased from 5% to 20% at 28 1C with optimum growth at the concentrations of 10% FBS. The morphology of RTF cell was predominantly fibroblastic like. Propagation of these cell lines was serum dependent, with a low plating efficiency (o15%). Karyotyping analysis of RTF cells at the 25th passage indicated that the modal chromosome number was 2n550. The cell line was cryopreserved in liquid nitrogen at �196 1C and could be recovered from storage after 6 months with good cell viability. Polymerase chain reaction amplification of a fragment of two mitochondrial genes, 16S rRNA and CO1, con¢rmed the identity of these cell lines with those reported from this animal species, confirming that the cell lines originated from P. denisonii. The bacterial extracellular products from Vibrio cholerae MTCC3904 and Aeromonas hydrophila were found to be toxic to RTF. The cell lines were not susceptible to viral nervous necrosis virus, a marine ¢sh virus

    SFRP4 signalling of apoptosis and angiostasis uses nitric oxide-cGMP-permeability axis of endothelium

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    Nitric oxide (NO) plays a critical role in endothelial functions such as cellular migration, vascular permeability and angiogenesis. Angiogenesis, the formation of new blood vessels from "pre-existing" ones is a carefully regulated process and essential during reproduction, development and wound healing. Previously our lab group reported that Secreted Frizzled-Related Protein 4 (sFRP4) could inhibit angiogenesis in both in vitro and in vivo conditions. sFRP4 belongs to a family of secreted glycoproteins that function as antagonists of the canonical Wnt signalling pathway. Although the pro-apoptotic role of sFRP4 is well discussed in literature, little is known in regards to its anti-angiogenic property. The objective of this study was to elucidate sFRP4 implications in NO biology of the endothelium. Results demonstrate that sFRP4 causes endothelial dysfunction by suppressing NO-cGMP signaling and elevating corresponding ROS levels. The imbalance between NO and ROS levels results in apoptosis and subsequent leakiness of endothelium as confirmed in vivo (Texas red/Annxin - CAM assay) and in vitro (Monolayer permeability assay) conditions. Furthermore utilizing peptides synthesized from the CRD domain of sFRP4, our results showed that while these peptides were able to cause endothelial dysfunctions, they did not cause apoptosis of the endothelial cells. Thereby confirming that sFRP4 can mediate its anti-angiogenic effect independent of its pro-apoptotic property. In conclusion, the current study reports that sFRP4-mediated anti-angiogenesis occurs as a result of impaired NO-cGMP signaling which in turn allow for elevation of redox levels and promotion of apoptosis of endothelial cells

    Structural basis of the carbohydrate specificities of Jacalin: an X-ray and modeling study

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    The structures of the complexes of tetrameric jacalin with Gal, Me-α-GalNAc, Me-α-T-antigen, GalNAcβ1-3Gal-α-O-Me and Galα1-6Glc (mellibiose) show that the sugar-binding site of jacalin has three components: the primary site, secondary site A, and secondary site B. In these structures and in the two structures reported earlier, Gal or GalNAc occupy the primary site with the anomeric carbon pointing towards secondary site A. The α-substituents, when present, interact, primarily hydrophobically, with secondary site A which has variable geometry. O-H···π and C-H···π hydrogen bonds involving this site also exist. On the other hand, β-substitution leads to severe steric clashes. Therefore, in complexes involving β-linked disaccharides, the reducing sugar binds at the primary site with the non-reducing end located at secondary site B. The interactions at secondary site B are primarily through water bridges. Thus, the nature of the linkage determines the mode of the association of the sugar with jacalin. The interactions observed in the crystal structures and modeling based on them provide a satisfactory qualitative explanation of the available thermodynamic data on jacalin-carbohydrate interactions. They also lead to fresh insights into the nature of the binding of glycoproteins by jacalin
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