1,188 research outputs found

    Initial Comparison of Single Cylinder Stirling Engine Computer Model Predictions with Test Results

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    A Stirling engine digital computer model developed at NASA Lewis Research Center was configured to predict the performance of the GPU-3 single-cylinder rhombic drive engine. Revisions to the basic equations and assumptions are discussed. Model predictions with the early results of the Lewis Research Center GPU-3 tests are compared

    Experiencing space–time: the stretched lifeworlds of migrant workers in India

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    In the relatively rare instances when the spatialities of temporary migrant work, workers’ journeys, and labour-market negotiations have been the subject of scholarly attention, there has been little work that integrates time into the analysis. Building on a case study of low-paid and insecure migrant manual workers in the context of rapid economic growth in India, we examine both material and subjective dimensions of these workers’ spatiotemporal experiences. What does it mean to live life stretched out, multiplyattached to places across national space? What kinds of place attachments emerge for people temporarily sojourning in, rather than moving to, new places to reside and work? Our analysis of the spatiotemporalities of migrant workers’ experiences in India suggests that, over time, this group of workers use their own agency to seek to avoid the experience of humiliation and indignity in employment relations. Like David Harvey, we argue that money needs to be integrated into such analysis, along with space and time. The paper sheds light on processes of exclusion, inequality and diff erentiation, unequal power geometries, and social topographies that contrast with neoliberalist narratives of ‘Indian shining

    Dissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soil

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    This dataset contains the data to the article: "Dissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soil" published in BiogeosciencesDFG/108154260/Elementkreisläufe in Grünland- und Waldökosystemen der Biodiversitätsexploratorien in Abhängigkeit von Landnutzungsintensität und damit verknüpfter Biodiversität/BECycle

    The TreaT-Assay: A Novel Urine-Derived Donor Kidney Cell-Based Assay for Prediction of Kidney Transplantation Outcome

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    Donor-reactive immunity plays a major role in rejection after kidney transplantation, but analysis of donor-reactive T-cells is not applied routinely. However, it has been shown that this could help to identify patients at risk of acute rejection. A major obstacle is the limited quantity or quality of the required allogenic stimulator cells, including a limited availability of donor-splenocytes or an insufficient HLA-matching with HLA-bank cells. To overcome these limitations, we developed a novel assay, termed the TreaT (Transplant reactive T-cells)-assay. We cultivated renal tubular epithelial cells from the urine of kidney transplant patients and used them as stimulators for donor-reactive T-cells, which we analyzed by flow cytometry. We could demonstrate that using the TreaT-assay the quantification and characterization of alloreactive T-cells is superior to other stimulators. In a pilot study, the number of pre-transplant alloreactive T-cells negatively correlated with the post-transplant eGFR. Frequencies of pre-transplant CD161+ alloreactive CD4+ T-cells and granzyme B producing alloreactive CD8+ T-cells were substantially higher in patients with early acute rejection compared to patients without complications. In conclusion, we established a novel assay for the assessment of donor-reactive memory T-cells based on kidney cells with the potential to predict early acute rejection and post-transplant eGFR

    Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability.

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    Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa

    Designing for digital wellbeing: A research & practice agenda

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    Traditionally, many consumer-focused technologies have been designed to maximize user engagement with their products and services. More recently, many technology companies have begun to introduce digital wellbeing features, such as for managing time spent and for encouraging breaks in use. These are in the context of, and likely in response to, renewed concerns in the media about technology dependency and even addiction. The promotion of technology abstinence is also increasingly widespread, e.g., via digital detoxes. Given that digital technologies are an important and valuable feature of many people's lives, digital wellbeing features are arguably preferable to abstinence

    Niobium based intermetallics as a source of high-current/high-magnetic field superconductors

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    The article is focused on low temperature intermetallic A15 superconducting wires development for Nuclear Magnetic Resonance, NMR, and Nuclear Magnetic Imaging, MRI, magnets and also on cryogen-free magnets. There are many other applications which would benefit from new development such as future Large Hadron Collider to be built from A15 intermetallic conductors. This paper highlights the current status of development of the niobium based intermetallics with special attention to Nb 3 (Al 1-x, Ge x). Discussion is focused on the materials science aspects of conductor manufacture, such as b-phase (A15) formation, with particular emphasis on the maximisation of the superconducting parameters, such as critical current density, Jc, critical temperature, Tc, and upper critical field, Hc2 . Many successful manufacturing techniques of the potential niobium-aluminide intermetallic superconducting conductors, such as solid-state processing, liquid-solid processing, rapid heating/cooling processes, are described, compared and assessed. Special emphasis has been laid on conditions under which the Jc (B) peak effect occurs in some of the Nb3(Al,Ge) wires. A novel electrodeoxidizing method developed in Cambridge whereby the alloys and intermetallics are produced cheaply making all superconducting electromagnetic devices, using low cost LTCs, more cost effective is presented.This new technique has potential to revolutionise the existing superconducting industry enabling reduction of cost orders of magnitude.Comment: Paper presented at EUCAS'01 conference, Copenhagen, 26-30 August 200

    The NRPD1 N-terminus contains a Pol IV-specific motif that is critical for genome surveillance in Arabidopsis

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    RNA-guided surveillance systems constrain the activity of transposable elements (TEs) in host genomes. In plants, RNA polymerase IV (Pol IV) transcribes TEs into primary transcripts from which RDR2 synthesizes double-stranded RNA precursors for small interfering RNAs (siRNAs) that guide TE methylation and silencing. How the core subunits of Pol IV, homologs of RNA polymerase II subunits, diverged to support siRNA biogenesis in a TE-rich, repressive chromatin context is not well understood. Here we studied the N-terminus of Pol IV’s largest subunit, NRPD1. Arabidopsis lines harboring missense mutations in this N-terminus produce wild-type (WT) levels of NRPD1, which co-purifies with other Pol IV subunits and RDR2. Our in vitro transcription and genomic analyses reveal that the NRPD1 N-terminus is critical for robust Pol IV-dependent transcription, siRNA production and DNA methylation. However, residual RNA-directed DNA methylation observed in one mutant genotype indicates that Pol IV can operate uncoupled from the high siRNA levels typically observed in WT plants. This mutation disrupts a motif uniquely conserved in Pol IV, crippling the enzyme's ability to inhibit retrotransposon mobilization. We propose that the NRPD1 N-terminus motif evolved to regulate Pol IV function in genome surveillance

    Schnelle und direkte Quantifizierung verschiedenartiger Kohlenstoffbindungsformen in Böden (incl. humusarme, Fe-oxidreiche Unterböden) mittels synchrotronstrahlenbasierter Röntgenabsorptionsspektroskopie (C K-edge XANES)

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    Die Speziierung verschiedenartiger C-Bindungsformen in Böden mit traditionellen nasschemischen oder instrumentellen Methoden (z.B. C-13-NMR-Spektroskopie) ist besonders für Proben mit geringen Humus- und hohen Eisenoxidgehalten (z.B. aus B- oder BC-Horizonten) langwierig und methodisch problembehaftet. Wir zeigen, dass synchrotronstrahlenbasierte Röntgenabsorptionsspektroskopie (C K-edge XANES) eine schnelle (benötigte Zeit pro Analyse ca. 30 Minuten), direkte (keine Bodenvorbehandlung außer ggf. Sieben und Mahlen) und erstaunlich akkurate Quantifizierung verschiedenartiger Kohlenstoffbindungsformen in Böden erlaubt – auch in humusarmen, eisenoxidreichen Unterbodenhorizonten. Dazu werden Ergebnisse einer Auswertung von C K-edge-XANES-Spektren unterschiedlicher bekannter Mischungen wichtiger „building blocks“ der organischen Bodensubstanz (Lignin, Cellulose, Aminosäuren) bzw. von C-Komponenten mit klar definierten C-Bindungsformen bzw. funktionellen C-Gruppen (Graphit: aromatischer C, Glucose: o-alkyl-C, Ca-Formiat: Carboxyl-C) vorgestellt und mit den jeweiligen theoretisch erwartbaren Werten verglichen. Außerdem werden C K-edge-XANES-Tiefenprofile unterschiedlicher Bodentypen unter Wald (Rendzina, Braunerde, Podsol) und die daraus berechneten Anteile verschiedenartiger C-Bindungsformen miteinander verglichen. Die vorgestellte Methode kann unseren Ergebnissen zufolge maßgeblich zur Aufklärung der Zusammensetzung und Struktur der organischen Substanz in Böden beitragen. Dies gilt insbesondere für Unterbodenhorizonte, deren Relevanz für die langfristige C-Speicherung in Böden und für wichtige bodenökologische Prozesse in den letzten Jahren als sehr bedeutsam erkannt wurde, deren Analyse mit bisher etablierten Verfahren aber besonders mühevoll und vermutlich auch oft fehlerbehaftet ist

    Imaging foreign bodies in head and neck trauma: a pictorial review

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    Open injuries bear the risk of foreign body contamination. Commonly encountered materials include gravel debris, glass fragments, wooden splinters or metal particles. While foreign body incorporation is obvious in some injury patterns, other injuries may not display hints of being contaminated with foreign body materials. Foreign objects that have not been detected and removed bear the risk of leading to severe wound infections and chronic wound healing disorders. Besides these severe health issues, medicolegal consequences should be considered. While an accurate clinical examination is the first step for the detection of foreign body materials, choosing the appropriate radiological imaging is decisive for the detection or non-detection of the foreign material. Especially in cases of impaired wound healing over time, the existence of an undetected foreign object needs to be considered. Here, we would like to give a practical radiological guide for the assessment of foreign objects in head and neck injuries by a special selection of patients with different injury patterns and various foreign body materials with regard to the present literature
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