406 research outputs found

    Horocycle dynamics: new invariants and eigenform loci in the stratum H(1,1)

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    We study dynamics of the horocycle flow on strata of translation surfaces, introduce new invariants for ergodic measures, and analyze the interaction of the horocycle flow and real Rel surgeries. We use this analysis to complete and extend results of Calta and Wortman classifying horocycle-invariant measures in the eigenform loci. We classify the orbit-closures and prove that every orbit is equidistributed in its orbit-closure. We also prove equidistribution statements regarding limits of sequences of measures, some of which have applications to counting problems.Comment: 100 page

    Generalized parton distributions: Status and perspectives

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    We summarize recent developments in understanding the concept of generalized parton distributions (GPDs), its relation to nucleon structure, and its application to high-Q2 electroproduction processes. Following a brief review of QCD factorization and transverse nucleon structure, we discuss (a) new theoretical methods for the analysis of deeply-virtual Compton scattering (t-channel-based GPD parametrizations, dispersion relations); (b) the phenomenology of hard exclusive meson production (experimental tests of dominance of small-size configurations, model-independent comparative studies); (c) the role of GPDs in small-x physics and pp scattering (QCD dipole model, central exclusive diffraction). We emphasize the usefulness of the transverse spatial (or impact parameter) representation for both understanding the reaction mechanism in hard exclusive processes and visualizing the physical content of the GPDs.Comment: 10 pages, 6 figures. Proceedings of SPIN2008, University of Virginia, October 6-11, 200

    Optimierung von Lupinenmehl fĂĽr die Aquakultur

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    Lupine aus ökologischen Anbau stellt eine nachhaltige und kostengünstige Alternative zu Fisch- und Sojamehl in Futtermitteln für die Aquakultur dar. Das Projekt "Optimierung von Lupinenmehl für die Aquakultur" (OLA) entwickelte Verfahren zur Steigerung der Verdaulichkeit von Lupinenmehl in Futtermitteln für karnivoren Wolfsbarsch, und analysierte die Vermarktungschancen von Lupine in der Fischfutterindustrie. Ein Hindernis in der Nutzung pflanzlicher Proteinquellen stellen Substanzen dar, sogenannte antinutritive Substanzen, die die Futteraufnahme und Verdauung von Fischen negativ beeinflussen können. Der Projektpartner, das ttz Bremerhaven, entwickelte in diesem Projekt ein enzymatisches Fermentationsverfahren um diese Substanzen im Lupinenmehl zu reduzieren und Verdaulichkeit und Akzeptanz zu fördern. Die Aquakulturforschung am AWI testete das fermentierte Lupinenmehl gegen herkömmliches Lupinenmehl in steigenden Mengen als Ersatz für Fischmehl in Akzeptanz- und Wachstumsversuchen. Diese zeigten, dass ein Futter mit 50% Lupine vergleichbare Wachstumsraten wie Futter aus 65% Fischmehl hervorbringt. Obwohl die Fermentation eine starke Reduktion der Phytinsäure im Lupinenmehl herbeiführte, hatte dies keine Wirkung auf die Wachstumsperformance bei Tieren über 15 g. Bei kleineren Tieren hatte die Fermentation jedoch eine positive Wirkung auf Wachstum. Enzymatische Analysen zeigten eine signifikante Beeinträchtigung der Verdauungsenzyme durch Lupine. In-vitro Analysen mit der pH-Stat Methode zeigten, dass diese durch Fermentation sowie Toasting reduziert wird. Stakeholderanalysen zeigten eine grundsätzliche positive Bewertung von Lupinen aus ökologischen Landbau als sinnvollen Futtermittelinhaltsstoff. Jedoch wurden Schwankungen beim Angebot, Qualität und Zusammensetzung sehr häufig bei größeren Abnehmern als Ausschluss Kriterium wahrgenommen. Insgesamt zeigte das Projekt, dass Lupinenbasierte Futtermittel (mit oder ohne thermische/ enzymatische Behandlung) sehr gut geeignet sind um sämtliche nutritiven Bedürfnisse der karnivorer Wolfsbarsche zu decken. Lupine wird aber sein Potential als Futtermittelinhaltsstoff nur erfüllen, wenn Engpässe in der Wertschöpfungskette durch Sicherung der Produkt-Qualität und Supply-Chain überwunden werden

    Prior human polyomavirus and papillomavirus infection and incident lung cancer: a nested case–control study

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    Purpose—To test whether infection with select human polyomaviruses (HPyV) and human papillomaviruses (HPV) is associated with incident lung cancer. Methods—We performed a nested case-control study, testing serum from the Carotene and Retinol Efficacy Trial CARET), conducted 1985–2005, for antibodies to Merkel cell (MCV), KI (KIV), and WU (WUV) HPyVs as well as to six high-risk and two low-risk HPV types. Incident lung cancer cases (n=200) were frequency-matched with controls (n=200) on age, enrollment and blood draw dates, intervention arm assignment, and the number of serum freeze / thaw cycles. Sera were tested using multiplex liquid bead microarray antibody assays. We used logistic regression to assess the association between HPyV and HPV antibodies and lung cancer. Results—There was no evidence of a positive association between levels of MCV, KIV, or WUV antibodies and incident lung cancer (P-corrected>0.10 for all trend tests; odds ratio (OR) range 0.72 to 1.09, P-corrected>0.10 for all). There was also no evidence for a positive association between HPV 16 or 18 infection and incident lung cancer (P-corrected≥0.10 for all trend tests; OR range 0.25 to 2.54, P>0.05 for all OR>1), but the number of persons with serologic evidence of these infections was small. Conclusions—Prior infection with any of several types of HPyV or HPV was not associated with subsequent diagnosis of lung cancer. Infection with these viruses likely does not influence a person’s risk of lung cancer in Western smoking populations

    Novel valosin-containing protein mutations associated with multisystem proteinopathy

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    Over fifty missense mutations in the gene coding for valosin-containing protein (VCP) are associated with a unique autosomal dominant adult-onset progressive disease associated with combinations of proximo-distal inclusion body myopathy (IBM), Paget's disease of bone (PDB), frontotemporal dementia (FTD), and amyotrophic lateral sclerosis (ALS). We report the clinical, histological, and molecular findings in four new patients/families carrying novel VCP mutations: c.474 G > A (p.M158I); c.478 G > C (p.A160P); c.383G > C (p.G128A); and c.382G > T (p.G128C). Clinical features included myopathy, PDB, ALS and Parkinson's disease though frontotemporal dementia was not an associated feature in these families. One of the patients was noted to have severe manifestations of PDB and was suspected of having neoplasia. There were wide inter- and intra-familial variations making genotype-phenotype correlations difficult between the novel mutations and frequency or age of onset of IBM, PDB, FTD, ALS and Parkinson's disease. Increasing awareness of the full spectrum of clinical presentations will improve diagnosis of VCP-related diseases and thus proactively manage or prevent associated clinical features such as PDB. (C) 2018 Published by Elsevier B.V.Peer reviewe

    DarkCarb: An Innovative Approach to Infrared Imaging

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    DarkCarb is a pioneering Earth observation (EO) satellite, under development at SSTL, designed to acquire high resolution Mid Wave Infrared (MWIR) imagery and video from low Earth orbit. The mission will set a precedent in IR performance from a small and capable satellite platform while maintaining the SSTL cost effective approach thereby enabling a spacecraft price which makes building constellations, capable of delivering rapid re-visit and wide area coverage, an attractive and worthwhile commercial investment. The DarkCarb satellite features an innovative low mass and volume MWIR imager which, when combined with the implementation of novel image enhancement algorithms, will achieve high quality 3.5m GSD imagery. The instrument is assembled using COTS devices and components fabricated using standard industry processes, optimised for production and rapid delivery of multiple instruments to meet constellation needs. The high spatial resolution DarkCarb MWIR imagery will deliver provides several key and complementary differentiators to visible imagery and therefore has the potential to become a high value data product for the EO market. MWIR imagery provides the capability to differentiate between objects and surfaces of different temperature and emissivity. As the detectable signal is only dependent on the temperature of the scene, DarkCarb also has the ability to extend imaging opportunities into the night. The video capability allows information on highly dynamic features in scenes to be provided and will be of key interest for applications relating to human activity. The DarkCarb mission is therefore a highly innovative development which has the potential to seriously disrupt the status quo of the commercial satellite imagery market by providing affordable high quality and high resolution MWIR data which will address a range of applications. With the DarkCarb Imager currently in production this paper will showcase the development to date with initial results from recent airborne flight trials and further explain the details of the unique payload which has been designed to meet the market need for responsive delivery at the right price

    Lessons Learned During the Implementation of a Cold Gas Propulsion System for the SunRISE Mission

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    The SunRISE mission utilizes a two-phase cold gas propulsion system, which provides several advantages over other cold gas systems but experienced challenges during assembly and testing. Since 2020, Georgia Tech Research Corporation (GTRC), Utah State University Space Dynamics Laboratory (SDL), and the Jet Propulsion Laboratory (FPL) have implemented several improvements to the SunRISE propulsion system. The SunRISE propulsion system leverages an additively manufactured monolithic structure, commercial off-the-shelf (COTS) valves and transducers, and the benign working fluid R-236fa to provide a suitable propulsion system for the SunRise mission. While the GTRC propulsion system had been developed for other missions, the multi-organizational team found and corrected several previously undetected design issues, including filters with highly variable flow performance, solenoid valve drive circuit issues, and inconsistencies in the tank additive manufacturing process that impacted manufacturing yield, thrust consistency, and quality of seals. Leaks in metallic fittings were also identified, and process improvements were put in place to mitigate them. Solenoid valve stiction was the last issue which was mitigated through valve screening and drive circuit adjustments. In this paper, we present lessons learned from the SunRISE propulsion system effort to aid future teams in identifying and addressing similar issues

    Complete genome sequence of Parvibaculum lavamentivorans type strain (DS-1T)

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    Parvibaculum lavamentivorans DS-1T is the type species of the novel genus Parvibaculum in the novel family Rhodobiaceae (formerly Phyllobacteriaceae) of the order Rhizobiales of Alphaproteobacteria. Strain DS-1T is a non-pigmented, aerobic, heterotrophic bacterium and represents the first tier member of environmentally important bacterial communities that catalyze the complete degradation of synthetic laundry surfactants. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 3,914,745 bp long genome with its predicted 3,654 protein coding genes is the first completed genome sequence of the genus Parvibaculum, and the first genome sequence of a representative of the family Rhodobiaceae
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