594 research outputs found

    Free-piston Stirling hydraulic engine and drive system for automobiles

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    The calculated fuel economy for an automotive free piston Stirling hydraulic engine and drive system using a pneumatic accumulator with the fuel economy of both a conventional 1980 spark ignition engine in an X body class vehicle and the estimated fuel economy of a 1984 spark ignition vehicle system are compared. The results show that the free piston Stirling hydraulic system with a two speed transmission has a combined fuel economy nearly twice that of the 1980 spark ignition engine - 21.5 versus 10.9 km/liter (50.7 versus 25.6 mpg) under comparable conditions. The fuel economy improvement over the 1984 spark ignition engine was 81 percent. The fuel economy sensitivity of the Stirling hydraulic system to system weight, number of transmission shifts, accumulator pressure ratio and maximum pressure, auxiliary power requirements, braking energy recovery, and varying vehicle performance requirements are considered. An important finding is that a multispeed transmission is not required. The penalty for a single speed versus a two speed transmission is about a 12 percent drop in combined fuel economy to 19.0 km/liter (44.7 mpg). This is still a 60 percent improvement in combined fuel economy over the projected 1984 spark ignition vehicle

    The narrative self, distributed memory, and evocative objects

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    In this article, I outline various ways in which artifacts are interwoven with autobiographical memory systems and conceptualize what this implies for the self. I first sketch the narrative approach to the self, arguing that who we are as persons is essentially our (unfolding) life story, which, in turn, determines our present beliefs and desires, but also directs our future goals and actions. I then argue that our autobiographical memory is partly anchored in our embodied interactions with an ecology of artifacts in our environment. Lifelogs, photos, videos, journals, diaries, souvenirs, jewelry, books, works of art, and many other meaningful objects trigger and sometimes constitute emotionally-laden autobiographical memories. Autobiographical memory is thus distributed across embodied agents and various environmental structures. To defend this claim, I draw on and integrate distributed cognition theory and empirical research in human-technology interaction. Based on this, I conclude that the self is neither defined by psychological states realized by the brain nor by biological states realized by the organism, but should be seen as a distributed and relational construct

    Expression of miRNA-106b in conventional renal cell carcinoma is a potential marker for prediction of early metastasis after nephrectomy

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    <p>Abstract</p> <p>Background</p> <p>MicroRNAs are endogenously expressed regulatory noncoding RNAs. Previous studies have shown altered expression levels of several microRNAs in renal cell carcinoma.</p> <p>Methods</p> <p>We examined the expression levels of selected microRNAs in 38 samples of conventional renal cell carcinoma (RCC) and 10 samples of non-tumoral renal parenchyma using TaqMan real-time PCR method.</p> <p>Results</p> <p>The expression levels of miRNA-155 (p < 0.0001), miRNA-210 (p < 0.0001), miRNA-106a (p < 0.0001) and miRNA-106b (p < 0.0001) were significantly over-expressed in tumor tissue, whereas the expression of miRNA-141 (p < 0.0001) and miRNA-200c (p < 0.0001) were significantly decreased in RCC samples. There were no significant differences between expression levels of miRNA-182 and miRNA-200b in tumor samples and renal parenchyma. Our data suggest that expression levels of miRNA-106b are significantly lower in tumors of patients who developed metastasis (p = 0.030) and miR-106b is a potential predictive marker of early metastasis after nephrectomy in RCC patients (long-rank p = 0.032).</p> <p>Conclusions</p> <p>We have confirmed previous observations obtained by miRNA microarray analysis using standardized real-time PCR method. For the first time, we have identified a prognostic significance of miRNA-106b, which, after validation on a larger group of patients, maybe useful as a promising biomarker in patients with RCC.</p

    Broadband Alfvénic excitation correlated to turbulence level in the Wendelstein 7-X stellarator plasmas

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    During the first operational phase (OP1) of the Wendelstein 7-X (W7-X) stellarator, poloidal magnetic field fluctuations, B˙θ\dot{B}_{\theta}, were measured in several different plasma scenarios with a system of Mirnov coils. In the spectrograms, multiple frequency bands close together in frequency are observed below f = 600 kHz. Furthermore, a dominant feature is the appearance of a frequency band with the highest spectral amplitude centred between f=180220f = 180-220 kHz. The fluctuations are observed from the beginning of most W7-X plasmas of OP1, which were often operated solely with electron cyclotron resonance heating. The fluctuations show characteristics known from Alfvén waves and possibly Alfvén eigenmodes (AEs). However, the fast particle drive from heating sources, which is generally a driver necessary for the appearance of AEs in magnetic confinement plasmas, is absent in most of the analysed experiments. A characterization of the Alfvénic fluctuations measured during OP1 plasmas is possible using a newly developed tracking algorithm. In this paper, we extensively survey the different spectral properties of the fluctuations in correlation with plasma parameters and discuss possible driving mechanisms. The correlation studies of the dynamics of the possible ellipticity induced AEs indicate that Alfvén activity in the frequency interval between f=100450f = 100-450 kHz could be excited due to an interaction with turbulence, or profile effects also affecting the turbulence amplitude

    Life satisfaction and residential satisfaction among college students at two Stuttgart universities : first descriptive results of a social science study on patterns of general and specific satisfaction among college students at the Vaihingen and the Hohenheim campus

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    In diesem Bericht werden erste Ergebnisse einer im Sommersemester 1999 durchgeführten Befragung unter rund 1000 Studierenden am Campus Vaihingen und Hohenheim vorgestellt. Im Zentrum des Interesses der Umfrage standen neben der allgemeinen Lebenszufriedenheit und den Zufriedenheiten der Studierenden in verschiedenen Lebensbereichen die Bewertung und Wahrnehmung der Wohnsituation und des jeweiligen Campus durch die Studierenden. Das Design der Studie wurde so gewählt, dass zum einem ein Vergleich der Situation der Studierenden am Campus Hohenheim und am Campus Vaihingen möglich ist. Zusätzlich ermöglicht das Studiendesign auch Vergleiche zwischen Studierenden, die am Campus wohnen und studieren, mit solchen, die 'nur' am Campus studieren. Die Ergebnisse belegen recht hohe Grade von Zufriedenheiten, die jedoch z.T. sehr deutlich nach verschiedenen sozialen Kontexten variieren. Als auffälligste Ergebnisse sind zu nennen, dass die Studierenden in Vaihingen mit ihrer Campussituation geringer zufrieden sind als die Studierenden in Hohenheim. Zudem zeigen die Analysen zu verschiedenen Bereichszufriedenheiten (u.a. Lebensstandard, Wohnsituation und Studium) und zur allgemeinen Lebenszufriedenheit, dass die Studierenden, die am Campus Vaihingen wohnen und studieren, im Vergleich zu allen anderen Studierenden stets geringere Zufriedenheiten äußern.This report presents first results of a survey among 1000 college students at the Vaihingen and the Hohenheim campus. The study concentrates on patterns of students general and specific life satisfaction. It explores students perception and evaluation of different areas of living at each campus. Due to its research design comparisons can be made between the situation at the Vaihingen and the Hohenheim campus and between students residing at the campus and students residing at other places outside the college area. The results show rather high degrees of satisfaction with variations according to different social contexts of living. The most striking results document higher degrees of satisfaction at the Hohenheim campus than at the Vaihingen campus. Students doing both residing and studying at the Vaihingen campus show the lowest degrees of satisfaction in comparison to all other groups of students concerning general life satisfaction and satisfaction with different area-specific topics (i.e. general standard of living, specific situations of housing and specific situations of studying and acade-mic activities)

    Die Zufriedenheit von Stuttgarter Studierenden mit ihrer Lebens- und Wohnsituation: erste deskriptive Ergebnisse einer sozialwissenschaftlichen Studie zu allgemeinen und bereichsspezifischen Zufriedenheiten der Studienrenden des Campus Vaihingen und des Campus Hohenheim

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    "In diesem Bericht werden erste Ergebnisse einer im Sommersemester 1999 durchgeführten Befragung unter rund 1000 Studierenden am Campus Vaihingen und Hohenheim vorgestellt. Im Zentrum des Interesses der Umfrage standen neben der allgemeinen Lebenszufriedenheit und den Zufriedenheiten der Studierenden in verschiedenen Lebensbereichen die Bewertung und Wahrnehmung der Wohnsituation und des jeweiligen Campus durch die Studierenden. Das Design der Studie wurde so gewählt, dass zum einem ein Vergleich der Situation der Studierenden am Campus Hohenheim und am Campus Vaihingen möglich ist. Zusätzlich ermöglicht das Studiendesign auch Vergleiche zwischen Studierenden, die am Campus wohnen und studieren, mit solchen, die 'nur' am Campus studieren. Die Ergebnisse belegen recht hohe Grade von Zufriedenheiten, die jedoch z.T. sehr deutlich nach verschiedenen sozialen Kontexten variieren. Als auffälligste Ergebnisse sind zu nennen, dass die Studierenden in Vaihingen mit ihrer Campussituation geringer zufrieden sind als die Studierenden in Hohenheim. Zudem zeigen die Analysen zu verschiedenen Bereichszufriedenheiten (u.a. Lebensstandard, Wohnsituation und Studium) und zur allgemeinen Lebenszufriedenheit, dass die Studierenden, die am Campus Vaihingen wohnen und studieren, im Vergleich zu allen anderen Studierenden stets geringere Zufriedenheiten äußern." (Autorenreferat)"This report presents first results of a survey among 1000 college students at the Vaihingen and the Hohenheim campus. The study concentrates an patterns of students' general and specific life satisfaction. It explores students' perception and evaluation of different areas of living at each campus. Due to its research design comparisons can be made between the situation at the Vaihingen and the Hohenheim campus and between students residing at the campus and students residing at other places outside the college area. The results show rather high degrees of satisfaction with variations according to different social contexts of living. The most striking results document higher degrees of satisfaction at the Hohenheim campus than at the Vaihingen campus. Students doing both residing and studying at the Vaihingen campus show the lowest degrees of satisfaction in comparison to all other groups of students concerning general life satisfaction and satisfaction with different area-specific topics (i.e. general standard of living, specific situations of housing and specific situations of studying and academic activities)." (author's abstract

    Sheep as a potential model of intradiscal infection by the bacterium Cutibacterium acnes

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    The anaerobic bacterium Cutibacterium acnes has been increasingly linked to the development of degenerative disc disease (DDD), although causality is yet to be conclusively proven. To better study how this organism could contribute to the aetiology of DDD, improved animal models that are more reflective of human disc anatomy, biology and mechanical properties are required. Against this background, our proof-of concept study aimed to be the first demonstration that C. acnes could be safely administered percutaneously into sheep intervertebral discs (IVDs) for in vivo study. Following our protocol, two sheep were successfully injected with a strain of C. acnes (8.3 × 106 CFU/disc) previously recovered from a human degenerative disc. No adverse reactions were noted, and at one-month post inoculation all triplicate infected discs in our first animal grew C. acnes, albeit at a reduced load (5.12 × 104 to 6.67 × 104 CFU/disc). At six months, no growth was detected in discs from our second animal indicating bacterial clearance. This pilot study has demonstrated the feasibility of safe percutaneous injection of C. acnes into sheep IVDs under fluoroscopic guidance. The design of follow-up sheep studies to investigate the potential of C. acnes to drive pathological changes within infected discs should now be pursued

    An Enrichment of CRISPR and Other Defense-Related Features in Marine Sponge-Associated Microbial Metagenomes

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    Many marine sponges are populated by dense and taxonomically diverse microbial consortia. We employed a metagenomics approach to unravel the differences in the functional gene repertoire among three Mediterranean sponge species, Petrosia ficiformis, Sarcotragus foetidus, Aplysina aerophoba and seawater. Different signatures were observed between sponge and seawater metagenomes with regard to microbial community composition, GC content, and estimated bacterial genome size. Our analysis showed further a pronounced repertoire for defense systems in sponge metagenomes. Specifically, clustered regularly interspaced short palindromic repeats, restriction modification, DNA phosphorothioation and phage growth limitation systems were enriched in sponge metagenomes. These data suggest that defense is an important functional trait for an existence within sponges that requires mechanisms to defend against foreign DNA from microorganisms and viruses. This study contributes to an understanding of the evolutionary arms race between viruses/phages and bacterial genomes and it sheds light on the bacterial defenses that have evolved in the context of the sponge holobiont

    MicroRNA-296 is enriched in cancer cells and downregulates p21WAF1 mRNA expression via interaction with its 3′ untranslated region

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    MicroRNAs (miRNAs) are a class of noncoding small RNAs that act as negative regulators of gene expression. To identify miRNAs that may regulate human cell immortalization and carcinogenesis, we performed comparative miRNA array profiling of human normal and SV40-T antigen immortalized cells. We found that miR-296 was upregulated in immortalized cells that also had activation of telomerase. By an independent experiment on genomic analysis of cancer cells we found that chromosome region (20q13.32), where miR-296 is located, was amplified in 28/36 cell lines, and most of these showed enriched miR-296 expression. Overexpression of miR-296 in human cancer cells, with and without telomerase activity, had no effect on their telomerase function. Instead, it suppressed p53 function that is frequently downregulated during human cell immortalization and carcinogenesis. By monitoring the activity of a luciferase reporter connected to p53 and p21WAF1 (p21) untranslated regions (UTRs), we demonstrate that miR-296 interacts with the p21-3′UTR, and the Hu binding site of p21-3′UTR was identified as a potential miR-296 target site. We demonstrate for the first time that miR-296 is frequently upregulated during immortalization of human cells and contributes to carcinogenesis by downregulation of p53-p21WAF1 pathway

    In Search for the Rationality of Moods

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    What it is about mood, as a specific type of affect, that makes it not easily amenable to standard models of rationality? It is commonly assumed that the cognitive rationality of an affective state is somehow depended upon how that state is related to what the state is about, its so called intentional object; but, given that moods do not seem to bear an intentional relation to an object, it is hard to see how they can be in the offing for rational assessment. In the first part of the paper I outline three ways of attributing intentionality to moods, raising for each one of them a series of problems, thus casting doubt on the viability of an intentionalist grounding for the rationality of moods. I then move to an examination of the view of moods as background feelings, which are intimately related to how we perceive the world; however, in my view, that approach fails to provide standards of assessment that would permit appraising the mood itself as rational or irrational. Finally, I look at an account of moods as mechanisms whose function is to monitor the balance between environmental demands and one’s physical or psychological resources. That is a promising way to proceed in our exploration of mood states; it faces though some formidable phenomenological challenges. All in all, defending the rationality of moods calls for a rethinking of the assumptions that are prevalent in the current literature over the representational dimension of affective states
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