221 research outputs found

    The Mark 3 Haploscope

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    A computer-operated binocular vision testing device was developed as one part of a system designed for NASA to evaluate the visual function of astronauts during spaceflight. This particular device, called the Mark 3 Haploscope, employs semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phoria, fixation disparity, refractive state and accommodation/convergence relationships. Test procedures are self-administered and can be used repeatedly without subject memorization. The Haploscope was designed as one module of the complete NASA Vision Testing System. However, it is capable of stand-alone operation. Moreover, the compactness and portability of the Haploscope make possible its use in a broad variety of testing environments

    Four-color flow cytometric analysis of peripheral blood donor cell chimerism

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    Passenger leukocytes have been demonstrated to play significant roles in initiating and also regulating immune reactions after organ transplantation. Reliable techniques to detect donor leukocytes in recipients after organ transplantation are essential to analyze the role, function, and behavior of these leukocytes. In this report we describe a simple, reliable method to detect donor cells with low frequencies using peripheral blood samples. Detection of small numbers of major histocompatibility complex (MHC) mismatched cells was first studied using four-color flow cytometry in artificially created cell mixtures. By selecting the CD45+ population and simultaneous staining with several leukocyte lineage markers (CD3, CD4, CD8, CD56, and CD19), MHC-mismatched leukocytes were consistently detected in cell suspensions prepared from directly stained whole blood samples with a threshold sensitivity as low as 0.1%-0.2%. When the fresh peripheral blood mononuclear cells were separated by conventional Ficoll gradient purification, similar, but slightly lower levels of donor cells were detected. Blood samples obtained 1-5 months after liver, kidney, and intestine transplants revealed that the kind of organ allograft influenced levels and lineage pattern of the circulating donor cells. This procedure provided a simple and reliable method in determining early chimerism in transplant recipients. However, the detection of MHC-mismatched leukocytes of all lineages was much lower when frozen peripheral blood mononuclear cells were used. © American Society for Histocompatibility and Immunogenetics, 2003. Published by Elsevier Inc

    Dystrophy in Istria: Molecular Genetic Approach. Part II: Analysis of Genetic Polymorphisms

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    One of the world highest prevalence estimates of myotonic dystrophy (DM) has been reported in the Croatian region Istria. To analyse the population genetic characteristics of DM locus in Istria, two intragenic and three extragenic polymorphic markers were tested. The Southern blot technique was used for D19S63 locus analysis, whereas PCR analysis was performed for CKMM, Alu polymorphism, DMPK (G/T) intron 9/HinfI polymorphism, and D19S207 genetic markers. The compound haplotypes segregating with DM were established. A complete association between the DM mutation and D19S63, D19S207, intron 9/HinfI polymorphism and Alu polymorphism markers were found. In all DM chromosomes: D19S63 and Alu markers had the allele 1 in common; D19S207 had the allele 3 in common, DMPK (G/T) intron 9/HinfI marker had the allele 2 in common. The analysis of CKMM polymorphism revealed genotype heterogeneity; in DM chromosomes either allele 2 or allele 4 were found. The haplotype analysis in the population of Croatian Istria supports the linkage disequilibrium between the DM mutation and Alu polymorphism, intron 9/HinfI polymorphism, D19S63 and D19S207 markers as reported worldwide. The results of the haplotype analysis suggest a common origin of the mutation in Istrian population

    The use of softer X-rays in the structure elucidation of microporous materials

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    Enhancing oxygen evolution functionality through anodization and nitridation of compositionally complex alloy

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    Compositionally complex materials (CCMs) have recently attracted great interest in electrocatalytic applications. To date, very few materials were systematically developed and tested due to the highly difficult preparation of high-surface-area CCMs. In this work, a surface of a compositionally complex FeCoNiCuZn alloy (CCA) was nitridated with subsequent anodization leading to morphological and compositional modifications. Notably, the electrochemical surface area and surface roughness as well as the electrocatalytic activity of the anodized material exhibit significant enhancement. Oxygen evolution reaction (OER) activity by the anodized CCN (CCN–AO) proceeds with remarkably small overpotential (233 mV) at 10 mA cm−2 in 1 M KOH. Experimental characterization indicates that the oxidation state of Co plays a critical role in the Fe–Co–Ni electrocatalyst. The developed approach and design strategy open up immense prospects in the preparation of a new, affordable, scalable and effective type of complex and high-performance electrocatalytic electrodes with tunable properties

    Structural investigations in pure-silica and Al-ZSM-12 with MTEA or TEA cations

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    Two different quaternary ammonium cations, methyltriethyl- (MTEA) and tetraethylammonium cations (TEA) were used as templates in the synthesis of pure-silica as well as aluminosilicate ZSM-12 (MTW-type) frameworks. The distribution of the template cations in the 12-membered rings channels in the 1-dimensional framework topology was studied; thus the as-prepared products were characterized by means of X-ray powder diffraction, Raman, transmission FTIR, solid-state NMR spectroscopy, thermogravimetric and elemental analyses and SEM. It was shown that in pure-silica (PS) ZSM-12, TEA cations are well ordered - a superstructure with three-times longer b edge (in comparison to unit cell of empty framework) along the channel is formed, which can be seen by virtue of a few additional peaks in the X-ray powder pattern. Herein we describe that its aluminosilicate counterpart with TEA also contains ordered TEA cations and is isostructural to PS-ZSM-12. Conversely, in both pure-silica and aluminosilicate ZSM-12 frameworks with MTEA, the cations are disordered and no superstructure is formed

    Review article: assessing the costs of natural hazards - state of the art and knowledge gaps

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    Efficiently reducing natural hazard risks requires a thorough understanding of the costs of natural hazards. Current methods to assess these costs employ a variety of terminologies and approaches for different types of natural hazards and different impacted sectors. This may impede efforts to ascertain comprehensive and comparable cost figures. In order to strengthen the role of cost assessments in the development of integrated natural hazard management, a review of existing cost assessment approaches was undertaken. This review considers droughts, floods, coastal and Alpine hazards, and examines different cost types, namely direct tangible damages, losses due to business interruption, indirect damages, intangible effects, and the costs of risk mitigation. This paper provides an overview of the state-of-the-art cost assessment approaches and discusses key knowledge gaps. It shows that the application of cost assessments in practice is often incomplete and biased, as direct costs receive a relatively large amount of attention, while intangible and indirect effects are rarely considered. Furthermore, all parts of cost assessment entail considerable uncertainties due to insufficient or highly aggregated data sources, along with a lack of knowledge about the processes leading to damage and thus the appropriate models required. Recommendations are provided on how to reduce or handle these uncertainties by improving data sources and cost assessment methods. Further recommendations address how risk dynamics due to climate and socio-economic change can be better considered, how costs are distributed and risks transferred, and in what ways cost assessment can function as part of decision support

    Sustainability of Global Golden Inland Waterways

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    Sustainable inland waterways should meet the needs of navigation without compromising the health of riverine ecosystems. Here we propose a hierarchical model to describe sustainable development of the Golden Inland Waterways (GIWs) which are characterized by great bearing capacity and transport need. Based on datasets from 66 large rivers (basin area > 100,000 km2) worldwide, we identify 34 GIWs, mostly distributed in Asia, Europe, North America, and South America, typically following a three-stage development path from the initial, through to the developing and on to the developed stage. For most GIWs, the exploitation ratio, defined as the ratio of actual to idealized bearing capacity, should be less than 80% due to ecological considerations. Combined with the indices of regional development, GIWs exploitation, and riverine ecosystem, we reveal the global diversity and evolution of GIWs' sustainability from 2015 to 2050, which highlights the importance of river-specific strategies for waterway exploitation worldwide
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