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The optical response of graded index spherical particles is studied using an effective medium approach, where the homogenization of the graded particle is achieved by using a static effective dielectric function available in the literature. Full-wave calculation using the standard Mie theory for this “homogenized system” shows that for a plasmonic particle, such an approximation can lead to highly-accurate results compared to the exact ones, especially for slowly and smoothly varying index profiles. An illustration is provided via an application of this method to the design of an optical cloak using a graded plasmonic coating based on the scattering cancellation scheme. This approach thus surpasses the various long-wavelength approximations currently available in the literature and provides an efficient numerical treatment of light scattering from these inhomogeneous particles without having to solve directly the Maxwell’s equations with spatially varying dielectric functions.

This study evaluates the two-dimensional (2D) stress intensity factors (SIFs) of a sharp V-notch using the image-correlation experiment and least-square method for isotropic materials. First, the William's eigenfunction and complex displacement function approach are deduced into a least-square form, and then displacement fields from the image-correlation experiment are substituted into the least-square equation to evaluate the 2D SIFs. Compared with the SIFs from finite element and body force methods, the least-squares method can be used to calculate SIFs more accurately, if more than two displacement terms are included. The SIFs calculated from this least-squares method are not sensitive to the maximum or minimum radius of the area from which data is included. The major advantage of the proposed method is that the procedure is simple and systematic, so it can be applied to any finite element or experimental methods that obtain displacement fields.

Ciglitizone, a class of thiazolidinediones, acts as a potent activator of the adipose differentiation program in established preadipose cell lines. Thiazolidinediones have also been investigated in diabetic patients and have been reported to act as peroxisome proliferator-activated receptor-γ ligands. Intramuscular adipogenesis or marbling through transdifferentiation of satellite cells in cattle was successfully conducted earlier. In this report, the effects of ciglitizone on the differentiation pathway of porcine myogenic satellite cells was investigated. Semitendinosus muscle was aseptically taken from 10-d-old piglets under general anesthesia, and porcine satellite cells were obtained and grown to near confluence. Postconfluent cells (d 0) were further cultured in differentiation medium containing an adipogenic mixture plus ciglitizone (10 μM) for 48 h. From d 2 onward, the cells were cultured only in the presence of ciglitizone until d 10. Controls were cultured in differentiation medium only. Exposure of porcine satellite cells to the adipogenic mixture plus ciglitizone generated lipid droplets on d 2, and subsequently, exposure of cells to ciglitizone alone helped in cytoplasmic lipid filling, providing them with the acquisition of adipocyte morphology. An increase (P< 0.05) in the fusion (structures containing 2 to 3 nuclei) of satellite cells was observed, and myosin heavy chain appeared with greater intensity (immunohistochemistry) in the control group from d 2 onward. Adipocyte-specific transcriptional factors (i.e., CCAAT/enhancer binding protein-α and peroxisome proliferator-activated receptor-γ) were predominant during transdifferentiation and were observed with immuhistochemistry, Western blot (~47.2 and ~60.4 kDa, respectively), and real-time PCR. Ciglitizone appeared to convert the differentiation pathway of satellite cells into that of adipoblasts.

When a T cell hybridoma, 707.7, was treated with a Ca²⁺ ionophore (A23187), apoptotic cell death was induced. Interestingly, we observed that the expression of Tcf-1, a T cell-specific transcription factor, mRNA was reduced by 5-fold in the A23187-treated apoptotic cells compared to an ethanol-treated control. The hybridoma cells, however, did not display such a reduced expression of Tcf-1 mRNA upon treatment with buthionine sulfoxide, which is known to induce a necrosis-like cell death. When another T cell hybridoma, KMIs-8.3.5, was treated with A23187 and phorbol myristate acetate, which leads to activation-induced apoptosis, Tcf-1 expression was again greatly reduced. However, a mutant line (KCIT1-8.5) derived from KMIs-8.3.5, which produces IL-2 upon activation and is resistant to apoptosis, did not show such reduction in Tcf-1 expression. We also showed that the reduced expression level of CD3_ε mRNA and surface TCR-CD3 complex in apoptotic T cells is caused by the reduced expression of Tcf-1. When 70.7 cells were transfected with a plasmid DNA pSVtcf-1, in which Tcf-1 gene expression is driven by the SV40 promoter, such reduction of the Tcf-1 mRNA and the surface expression of the TCR-CD3 complex were not observed upon apoptosis induction. Our results suggest that the reduced expression of Tcf-1 is specific for the apoptotic, but not for the activating, process of T cells and is also responsible for the reduced surface expression of the TCR-CD3 in apoptotic T cells.

Effective transposon tagging with theAc/Ds system in heterologous plant species relies on the accomplishment of a potentially high transposon-induced mutation frequency. The primary parameters that determine the mutation frequency include the transposition frequency and the transposition distance. In addition, the development of a generally applicable transposon tagging strategy requires predictable transposition behaviour. We systematically analysedDs transposition frequencies andDs transposition distances in tobacco. An artificialDs element was engineered with reporter genes that allowed transposon excision and integration to be monitored visually. To analyse the variability ofDs transposition between different tobacco lines, eight single copy T-DNA transformants were selected. Fortrans-activation of theDs elements, differentAc lines were used carrying an unmodifiedAc+ element, an immobilizedsAc element and a stableAc element under the control of a heterologous chalcone synthas (chsA) promoter. With allAc elements, eachDs line showed characteristic and heritable variegation patterns at the seedling level. SimilarDs line-specificity was observed for the frequency by whichDs transpositions were germinally transmitted, as well as for the distances of theDs transpositions. ThesAc element induced transposition ofDs late in plant development, resulting in low germinal transposition frequencies (0.37%) and high incidences of independent transposition (83%). The majority of theseDs elements (58%) transposed to genetically closed linked sites (≤10 cM).

An approach for the constrained variance control of nonlinear stochastic systems, which uses the theory of covariance control of linear stochastic systems, is proposed. The nonlinear stochastic systems are linearised by the use of describing functions. Two cases of nonlinear systems are considered: zero-mean nonlinear stochastic systems and nonzero-mean nonlinear stochastic systems. The application of this approach to a position servomechanism is illustrated by a numerical example.

The resistance mechanisms of more than 2,000 aminoglycoside-resistant gram-negative aerobic bacteria were estimated by a method that assigned a biochemical mechanism based on susceptibility to selected aminoglycosides. Strains from hospitals in Japan, Formosa, and Korea (the Far East) were compared with strains from Chile and the United States. Of the strains from Chile, 90% had an aminoglycoside resistance pattern indicative of the 3-N-acetyltransferase [AAC(3)-V] enzyme. Of the strains from the Far East, 78% had susceptibility patterns suggesting the presence of AAC(6') enzymes. In contrast, strains from the United States had a wider variety of resistance mechanisms including 2''-O-adenylyltidyltransferase [ANT(2'')], AAC(3), AAC(6'), and AAC(2'). Reflecting these differences in resistance patterns, the frequencies of resistance to gentamicin, tobramycin, dibekacin, and amikacin in strains from the United States were different from those in strains from the Far East. These differences seem to be correlated with different aminoglycoside usage in the two regions. In the United States, where gentamicin was the most widely used aminoglycoside, 92% of the strains were resistant to gentamicin, 81% were resistant to dibekacin, and 8.8% were resistant to amikacin. In the Far East, dibekacin and kanamycin were widely used in the past and more recently amikacin has been frequently used. Of the strains from this region, 99% were resistant to dibekacin, 85% were resistant to gentamicin, and 35% were resistant to amikacin.

When a T cell hybridoma, 70.7, was treated with a Ca2+ ionophore (A23187), apoptotic cell death was induced. Interestingly, we observed that the expression of Tcf-1, a T cell-specific transcription factor, mRNA was reduced by approximately 5-fold in the A23187-treated apoptotic cells compared to an ethanol-treated control. The hybridoma cells, however, did not display such a reduced expression of Tcf-1 mRNA upon treatment with buthionine sulfoxide, which is known to induce a necrosis-like cell death. When another T cell hybridoma, KMIs-8.3.5, was treated with A23187 and phorbol myristate acetate, which leads to activation-induced apoptosis, Tcf-1 expression was again greatly reduced. However, a mutant line (KCIT1-8.5) derived from KMIs-8.3.5, which produces IL-2 upon activation and is resistant to apoptosis, did not show such reduction in Tcf-1 expression. We also showed that the reduced expression level of CD3epsilon mRNA and surface TCR-CD3 complex in apoptotic T cells is caused by the reduced expression of Tcf-1. When 70.7 cells were transfected with a plasmid DNA pSVtcf-1, in which Tcf-1 gene expression is driven by the SV40 promoter, such reduction of the Tcf-1 mRNA and the surface expression of the TCR-CD3 complex were not observed upon apoptosis induction. Our results suggest that the reduced expression of Tcf-1 is specific for the apoptotic, but not for the activating, process of T cells and is also responsible for the reduced surface expression of the TCR-CD3 in apoptotic T cells.

An attempt is made to characterise, qualitatively and quantitatively, the major differences between H∞ and H2-optimal model matching control. Conditions under which the effectiveness of model matching in H∞-norm space is superior to that in H2-norm space are derived. According to these conditions, designers can easily decide between H∞ and H2 approaches to meet the required performance.

Bioassay-guided fractionation of an organic extract of the broth from the marine-derived fungus culture of Aspergillus parasiticus led to the isolation and subsequent structural elucidation of a new gabosine derivative, parasitenone (1), and two known benzyl alcohols, 3-chloro-4,5-dihydroxybenzyl alcohol (2) and gentisyl alcohol (3). The benzyl alcohols (2, 3) were identified as the principal free radical scavenging components. Parasitenone (1) also showed moderate activity in the free radical scavenging assay.

From an extract of the red alga Symphyocladia latiuscula, a bromophenol (1) was isolated and characterized as (2R)-2-(2,3,6-tribromo-4,5-dihydroxybenzyl)-cyclohexanone based on the spectroscopic evidence. The bromophenol was found to be a scavenger of 1,1-diphenyl-2-picrylhydrazyl radical.