396 research outputs found

    Marine epibiosis. IV The periwinkle Littonna littorea lacks typical antifculing defences - why are some populations so little fouled?

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    Epibiosis on the shells of Littorina littorea (L.) varies between populations. While snails from the Helgoland intertidal zone (North Sea) rarely carry any epibionts, subtidal snails from the Kiel Bight (Baltic Sea) are frequently fouled. This study shows that L. littorea lacks typical anti-fouling defence adaptations such as mechanical, physical or chemical defences. Our enclosure experiments suggest that epibiosis on the shells is inversely correlated to L. littorea population density. At high densities snails frequently pass over one another and subsequent grazing, bulldozing and/or foot mucus secretion may contribute to the inhibition of epibionts. Consequently, the observed differences in shell epibiosis between the 2 L. littorea populations may to a large extent be explained by considerably higher L. littorea abundances in the Helgoland intertidal zone. Differences in habitat conditions probably play a secondary role. We suggest that the fouling inhibiting factors associated with high population density (mucus secretion, bulldozing, mutual grazing) are to be considered as a biological disturbance which effectively blocks recruitment by most potential colonizers

    Adenovirus RIDα regulates endosome maturation by mimicking GTP-Rab7

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    The small guanosine triphosphatase Rab7 regulates late endocytic trafficking. Rab7-interacting lysosomal protein (RILP) and oxysterol-binding protein–related protein 1L (ORP1L) are guanosine triphosphate (GTP)–Rab7 effectors that instigate minus end–directed microtubule transport. We demonstrate that RILP and ORP1L both interact with the group C adenovirus protein known as receptor internalization and degradation α (RIDα), which was previously shown to clear the cell surface of several membrane proteins, including the epidermal growth factor receptor and Fas (Carlin, C.R., A.E. Tollefson, H.A. Brady, B.L. Hoffman, and W.S. Wold. 1989. Cell. 57:135–144; Shisler, J., C. Yang, B. Walter, C.F. Ware, and L.R. Gooding. 1997. J. Virol. 71:8299–8306). RIDα localizes to endocytic vesicles but is not homologous to Rab7 and is not catalytically active. We show that RIDα compensates for reduced Rab7 or dominant-negative (DN) Rab7(T22N) expression. In vitro, Cu2+ binding to RIDα residues His75 and His76 facilitates the RILP interaction. Site-directed mutagenesis of these His residues results in the loss of RIDα–RILP interaction and RIDα activity in cells. Additionally, expression of the RILP DN C-terminal region hinders RIDα activity during an acute adenovirus infection. We conclude that RIDα coordinates recruitment of these GTP-Rab7 effectors to compartments that would ordinarily be perceived as early endosomes, thereby promoting the degradation of selected cargo

    Жанровые особенности корпоративного сайта (на материале сайтов российской и французской нефтегазовых компаний)

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    Исследование посвящено выявлению жанровых особенностей сайта как элемента корпоративной культуры организации. Рассмотрены коммуникативные цели, образ автора и адресата, диктумное содержание (контент), образ прошлого и будущего, особенности языковых средств и лингвистического дизайна корпоративных сайтов российской и французской нефтегазовых компаний. Описаны типологические характеристики корпоративного сайта как ядерного речевого жанра виртуального дискурса, выявлена реализация в жанровых параметрах сайта специфики корпоративной культуры организации, обнаружено проявление в жанре корпоративного сайта национально-культурных особенностей.The purpose of the study is to identify genre features of commercial website as a part of organizational culture. The study analyzed communicative purposes, images of author and recipient, content, images of past and future, language features and linguistic design of commercial site of Russian and French oil and gas companies. In the process of the research typological features of commercial site as a central speech genre of virtual discourse are described, realisation of organisational culture features in genres parametres was identified, national and cultural features were revealed in the genre of organizational website

    Efficient unidirectional nanoslit couplers for surface plasmons

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    Plasmonics is based on surface plasmon polariton (SPP) modes which can be laterally confined below the diffraction limit, thereby enabling ultracompact optical components. In order to exploit this potential, the fundamental bottleneck of poor light-SPP coupling must be overcome. In established SPP sources (using prism, grating} or nanodefect coupling) incident light is a source of noise for the SPP, unless the illumination occurs away from the region of interest, increasing the system size and weakening the SPP intensity. Back-side illumination of subwavelength apertures in optically thick metal films eliminates this problem but does not ensure a unique propagation direction for the SPP. We propose a novel back-side slit-illumination method based on drilling a periodic array of indentations at one side of the slit. We demonstrate that the SPP running in the array direction can be suppressed, and the one propagating in the opposite direction enhanced, providing localized unidirectional SPP launching.Comment: 13 pages, 4 figure

    Nanoantennas for visible and infrared radiation

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    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-ofstates engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of optical antennas based on the background of both well-developed radiowave antenna engineering and the emerging field of plasmonics. In particular, we address the plasmonic behavior that emerges due to the very high optical frequencies involved and the limitations in the choice of antenna materials and geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.Comment: Review article with 76 pages, 21 figure

    Effectiveness of the Austrian disease-management-programme for type 2 diabetes: study protocol of a cluster-randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Due to its rising prevalence type 2 diabetes plays an important role concerning population health in Austria and other western countries. In various studies deficiencies in the care of diabetic patients have been revealed. These deficiencies may be overcome by disease-management-programmes (DMPs), but international experience shows that the effectiveness of DMPs is inconsistent. In particular large programmes designed by state-affiliated public health insurances have not been evaluated in randomized controlled trials (RCTs). We are therefore conducting a large scale RCT of the Austrian DMP for type 2 diabetic patients in the province of Salzburg to evaluate the programme regarding its effects on metabolic control, guideline adherent care and the quality of life of diabetic patients.</p> <p>Methods/Design</p> <p>The study is open for participation to all GPs and internists in the province of Salzburg. Physicians are randomized before recruitment of patients with the districts of Salzburg as clusters of randomisation. A total of over 1200 patients with type 2 diabetes will then be recruited. In the intervention group the DMP is applied for one year. Controls receive usual care. Endpoints are a decrease in HbA1c in the intervention group > 0,5% compared to controls, a higher percentage of patients with required diagnostic measures according to guidelines, improved cardiovascular risk profile and higher quality of life scores within one year.</p> <p>Current status of the study</p> <p>98 Physicians agreed to participate in the study. 96 of them recruited 1494 patients, 654 in the intervention and 840 in the control group.</p> <p>Trail Registration</p> <p>This trial has been registered with Current Controlled Trials Ltd. (ISRCTN27414162).</p

    Enhanced plasmonic behavior of bimetallic (Ag-Au) multilayered spheres

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    In this article we study the plasmonic behavior of some stable, highly biocompatible bimetallic metal-dielectric-metal (MDM) and double concentric nanoshell (DCN) structures. By simply switching the material of the inner structure from Au to Ag, the intensity of their surface plasmon resonance could be increased in the optical transparency region of the human tissues up to 20 and 60 percent for the MDM and DCN, respectively, while the biocompatibility is retained. The obtained results indicate that these novel structures could be highly suitable for surface enhanced Raman scattering and photothermal cancer therapy

    An image analysis toolbox for high-throughput C. elegans assays

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    We present a toolbox for high-throughput screening of image-based Caenorhabditis elegans phenotypes. The image analysis algorithms measure morphological phenotypes in individual worms and are effective for a variety of assays and imaging systems. This WormToolbox is available through the open-source CellProfiler project and enables objective scoring of whole-worm high-throughput image-based assays of C. elegans for the study of diverse biological pathways that are relevant to human disease.National Institutes of Health (U.S.) (U54 EB005149

    The effectiveness of the Austrian disease management programme for type 2 diabetes: a cluster-randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Disease management programmes (DMPs) are costly and impose additional work load on general practitioners (GPs). Data on their effectiveness are inconclusive. We therefore conducted a cluster-randomised controlled trial to evaluate the effectiveness of the Austrian DMP for diabetes mellitus type 2 on HbA1c and quality of care for adult patients in primary care.</p> <p>Methods</p> <p>All GPs of Salzburg-province were invited to participate. After cluster-randomisation by district, all patients with diabetes type 2 were recruited consecutively from 7-11/2007. The DMP, consisting mainly of physician and patient education, standardised documentation and agreement on therapeutic goals, was implemented in the intervention group while the control group received usual care. We aimed to show superiority of the intervention regarding metabolic control and process quality. The primary outcome measure was a change in HbA1c after one year. Secondary outcomes were days in the hospital, blood pressure, lipids, body mass index (BMI), enrolment in patient education and regular guideline-adherent examination. Blinding was not possible.</p> <p>Results</p> <p>92 physicians recruited 1489 patients (649 intervention, 840 control). After 401 ± 47 days, 590 intervention-patients and 754 controls had complete data. In the intention to treat analysis (ITT) of all 1489 patients, HbA1c decreased 0.41% in the intervention group and 0.28% in controls. The difference of -0.13% (95% CI -0.24; -0.02) was significant at p = 0.026. Significance was lost in mixed models adjusted for baseline value and cluster-effects (adjusted mean difference -0.03 (95% CI -0.15; 0.09, p = 0.607). Of the secondary outcome measures, BMI and cholesterol were significantly reduced in the intervention group compared to controls in ITT after adjustments (-0.53 kg/m²; 95% CI -1.03;-0.02; p = 0.014 and -0.10 mmol/l; 95% CI -0.21; -0.003; p = 0.043). Additionally, more patients received patient education (49.5% vs. 20.1%, p < 0.0001), eye- (71.0% vs. 51.2%, p < 0.0001), foot examinations (73.8% vs. 45.1%, p < 0.0001), and regular HbA1c checks (44.1% vs. 36.0%, p < 0.01) in the intervention group.</p> <p>Conclusion</p> <p>The Austrian DMP implemented by statutory health insurance improves process quality and enhances weight reduction, but does not significantly improve metabolic control for patients with type 2 diabetes mellitus. Whether the small benefit seen in secondary outcome measures leads to better patient outcomes, remains unclear.</p> <p>Trial Registration</p> <p>Current Controlled trials Ltd., ISRCTN27414162.</p
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