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Selected AbstractsExpression and regulation of the pattern recognition receptors Toll-like receptor-2 and Toll-like receptor-4 in the human placentaIMMUNOLOGY, Issue 1 2002Ulrika Holmlund Summary The placenta constitutes a physical and immunological barrier against invading infectious agents and has been suggested to be a pregnancy-specific component of the innate immune system. The aim of this study was to investigate the presence and regulation of Toll-like receptors-2 and -4 (TLR2 and TLR4) in the human placenta, because these receptors are believed to be important for immune responses against pathogens. Twenty-eight placentas from normal term pregnancies were analysed with immunohistochemistry, which showed a strong immunoreactivity for TLR2 and TLR4 in the villous and the intermediate trophoblasts. The regulation of TLR2 and TLR4 by microbial stimulus was assessed by incubating explants of term chorionic villi with zymosan or lipopolysaccharide (LPS) and analysed with real-time reverse transcriptase,polymerase chain reaction. Stimulation with zymosan and LPS readily induced interleukin (IL)-6 and IL-8 cytokine production in the placenta cultures, whereas TLR2 and TLR4 mRNA and protein expression remained at the same high level as in unstimulated explants. These data suggests a novel mechanism for the fetoplacental unit to interact with micro-organisms. [source] Pyramiding of Xa7 and Xa21 for the improvement of disease resistance to bacterial blight in hybrid ricePLANT BREEDING, Issue 6 2006J. Zhang Abstract ,Minghui 63' is a restorer line widely used in hybrid rice production in China for the last two decades. This line and its derived hybrids, including ,Shanyou 63', are susceptible to bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo). To improve the bacterial blight resistance of hybrid rice, two resistance genes Xa21 and Xa7, have been introgressed into ,Minghui 63' by marker-assisted selection and conventional backcrossing, respectively. The single resistance gene-introgressed lines, Minghui 63 (Xa21) and Minghui 63 (Xa7) had higher levels of resistance to bacterial blight than their derived hybrids, Shanyou 63 (Xa21) or Shanyou 63 (Xa7). Both Xa21 and Xa7 showed incomplete dominance in the heterozygous background of rice hybrids by infection with GX325 and KS-1-21. The improved restorer lines, with the homozygous genotypes, Xa21Xa21 or Xa7Xa7, were more resistant than their hybrids with the heterozygous genotypes Xa21xa21 or Xa7xa7. To further enhance the bacterial blight resistance of ,Minghui 63' and its hybrids, Xa21 and Xa7 were pyramided into the same background using molecular marker-aided selection. The restorer lines developed with the resistance genes Xa21 and Xa7, and their derived hybrids were evaluated for resistance after inoculation with 10 isolates of pathogens from China, Japan and the Philippines, and showed a higher level of resistance to BB than the restorer lines and derived hybrids having only one of the resistance genes. The pyramided double resistance lines and their derived hybrids have the same high level of resistance to BB. These results clearly indicate that pyramiding of dominant genes is a useful approach for improving BB resistance in hybrid rice. [source] Experimental evidence of parasitic shunting in silicon nitride rear surface passivated solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 4 2002Stefan Dauwe Many solar cells incorporating SiNx films as a rear surface passivation scheme have not reached the same high level of cell performance as solar cells incorporating high-temperature-grown silicon dioxide films as a rear surface passivation. In this paper, it is shown by direct comparison of solar cells incorporating the two rear surface passivation schemes, that the performance loss is mainly due to a lower short-circuit current while the open-circuit voltage is equally high. With a solar cell test structure that features a separation of the rear metal contacts from the passivating SiNx films, the loss in short-circuit current can be reduced drastically. Besides a lower short- circuit current, dark I,V curves of SiNx rear surface passivated solar cells exhibit distinct shoulders. The results are explained by parasitic shunting of the induced floating junction (FJ) underneath the SiNx films with the rear metal contacts. The floating junction is caused by the high density of fixed positive charges in the SiNx films. Other two-dimensional effects arising from the injection level dependent SRV of the Si/SiNx interfaces are discussed as well, but, are found to be of minor importance. Pinholes in the SiNx films and optical effects due to a different internal rear surface reflectance can be excluded as a major cause for the performance loss of the SiNx rear surface passivated cells. Copyright © 2002 John Wiley & Sons, Ltd. [source] A population-based study of macular thickness in full-term children assessed with Stratus OCT: normative data and repeatabilityACTA OPHTHALMOLOGICA, Issue 7 2009Urban Eriksson Abstract. Purpose:, We aimed to determine normal macular thickness values, assessed with optical coherence tomography (OCT), in a population of full-term children of normal birthweight. Methods:, A total of 56 children, aged 5,16 years, randomly chosen from the population register, were examined with Stratus OCT. Only children with visual acuity < 0.2 logMAR, spherical equivalent of , 3 to + 3 D and astigmatism < 2 D were included. The fast macular map protocol was used and three examinations were performed in each eye. One eye was then randomized for further analyses. Mean values for the nine ETDRS areas, foveal minimum thickness and macular volume were calculated for 55 eyes. Coefficients of variance and intraclass correlations were calculated for each area. Results:, All children co-operated well and no child was excluded for lack of concentration. Mean ± standard deviation central macular thickness was 204 ± 19 ,m. Mean total macular volume was 7.11 ± 0.35 mm3. No correlations were found between age, gender and macular thickness. Coefficients of variance were < 2% and intraclass correlations were > 0.9 in all areas, except the foveal minimum. Conclusions:, Normal values for macular thickness in healthy full-term children were reported. As the Stratus OCT provides normal values only for adults, these data are a better alternative for comparison with children with retinal abnormalities. We concluded that OCT is suitable for examining the retina in children aged 5,16 years and has the same high level of repeatability as in adults. [source] Evaluation of the CLSI cefoxitin 30-µg disk-diffusion method for detecting methicillin resistance in staphylococciCLINICAL MICROBIOLOGY AND INFECTION, Issue 10 2006L.-X. Zhu Abstract Methicillin susceptibility of 415 staphylococcal isolates from Chinese hospitals was assessed using the CLSI disk-diffusion method with a cefoxitin 30-µg disk in comparison with an oxacillin 1-µg disk. PCR-based detection of mecA was the reference standard. The cefoxitin 30-µg disk performed with almost the same high level of accuracy as the oxacillin 1-µg disk in detecting methicillin resistance in Staphylococcus aureus. For coagulase,negative staphylococci (CoNS), the sensitivity of the cefoxitin 30-µg disk was 90.5%, compared with 83.4% for the oxacillin 1-µg disk. Confirmatory testing of isolates with borderline susceptibility and revision of the cefoxitin breakpoint are proposed in order to categorise CoNS more accurately. [source] Seeing without being seen: a removal experiment with mixed flocks of Willow and Crested Tits Parus montanus and cristatusIBIS, Issue 4 2001INDRIK IS KRAMS This paper tests the hypothesis that foraging site selection reflects a trade-off between the various needs for concealment from predators, to find food, and for the individual to maintain some view of its surroundings. After removal of Crested Tits Parus cristatus (the dominant species in mixed flocks), Willow Tits P. montanus did not decrease their foraging heights as expected but remained in the most exposed parts of young pines. In contrast, after removal of Willow Tits, Crested Tits increased their foraging height from the sheltered lower canopy to sites previously occupied by Willow Tits. When flock size was reduced, the birds maintained the same high levels of vigilance without concealing themselves in dense vegetation. I suggest that flock members may benefit from foraging in sites that afford good anti-predator vigilance. [source] | |||||||||||||