Bounds on the spectrum and reducing subspaces of a J-self-adjoint operator

Given a self-adjoint involution J on a Hilbert space H, we consider a J-self-adjoint operator L=A+V on H where A is a possibly unbounded self-adjoint operator commuting with J and V a bounded J-self-adjoint operator anti-commuting with J. We establish optimal estimates on the position of the spectrum of L with respect to the spectrum of A and we obtain norm bounds on the operator angles between maximal uniformly definite reducing subspaces of the unperturbed operator A and the perturbed operator L. All the bounds are given in terms of the norm of V and the distances between pairs of disjoint spectral sets associated with the operator L and/or the operator A. As an example, the quantum harmonic oscillator under a PT-symmetric perturbation is discussed. The sharp norm bounds obtained for the operator angles generalize the celebrated Davis-Kahan trigonometric theorems to the case of J-self-adjoint perturbations.Comment: (http://www.iumj.indiana.edu/IUMJ/FULLTEXT/2010/59/4225

OPA1 processing controls mitochondrial fusion and is regulated by mRNA splicing, membrane potential, and Yme1L

OPA1, a dynamin-related guanosine triphosphatase mutated in dominant optic atrophy, is required for the fusion of mitochondria. Proteolytic cleavage by the mitochondrial processing peptidase generates long isoforms from eight messenger RNA (mRNA) splice forms, whereas further cleavages at protease sites S1 and S2 generate short forms. Using OPA1-null cells, we developed a cellular system to study how individual OPA1 splice forms function in mitochondrial fusion. Only mRNA splice forms that generate a long isoform in addition to one or more short isoforms support substantial mitochondrial fusion activity. On their own, long and short OPA1 isoforms have little activity, but, when coexpressed, they functionally complement each other. Loss of mitochondrial membrane potential destabilizes the long isoforms and enhances the cleavage of OPA1 at S1 but not S2. Cleavage at S2 is regulated by the i-AAA protease Yme1L. Our results suggest that mammalian cells have multiple pathways to control mitochondrial fusion through regulation of the spectrum of OPA1 isoforms

Operation of Ageing Reactors: Approaches and associated Research in the European Union

Plant Life Management (PLiM) of existing nuclear power plants in EU may consider longer term operability. This becomes an option with specific advantages and is under consideration in some Member States. It however unveils number of challenges that are closely related with extending the operational life of structures and components (SC) beyond the established operational time frame at the time they were designed. Safety related aspects of long term operations are obvious; for those SC important to safety that are selected for evaluation it is necessary to demonstrate that they perform the intended safety functions with sufficient safety margins for the entire period of operations. The ageing phenomena needs to be timely and carefully considered, in particular by structural integrity assessment, accident analysis, nuclear power plant ageing assessment and mitigation, systems interactions and risk assessment with related human factor aspects. A broad and effective dissemination of related scientific results is a further objective. The European Union, which sees a large diversity of nuclear plant types, needs a targeted investigation to upgrade knowledge on their objective safety levels. Research activities therefore concentrate on providing the scientific and technical knowledge in relation to safety important issues needed for Community policy support and for helping to enhance nuclear safety in EU and beyond. The European Commission launched within the EURATOM framework programme FP7 a research and support programme related to PLiM issues under progress at Joint Research Centre and involves partners from nuclear industry and Technical Support Organizations through several dedicated networks and projects. This report aims to provide overview of approaches proposed or followed in the USA and in EU countries when longer term operability (LTO) is considered as part of PLiM. A special attention is given to discussing existing regulatory framework available, as well as requirements set for ageing reactors in the corresponding IAEA safety reports and safety guides. A comparison of the US Licence Renewal Rule and Periodic Safety Review as a tool for assessment of Structure, Systems and Components (SSC) for PLiM and LTO is provided too. The present report also discuses several current challenges, and shows some examples how the research is supporting / or can support the safety assessment of ageing nuclear power plants in the European Union.JRC.F.5-Nuclear Reactor Safety Assessmen

In-Situ Defect Detection in Laser Powder Bed Fusion by Using Thermography and Optical Tomography—Comparison to Computed Tomography

Among additive manufacturing (AM) technologies, the laser powder bed fusion (L-PBF) is one of the most important technologies to produce metallic components. The layer-wise build-up of components and the complex process conditions increase the probability of the occurrence of defects. However, due to the iterative nature of its manufacturing process and in contrast to conventional manufacturing technologies such as casting, L-PBF offers unique opportunities for in-situ monitoring. In this study, two cameras were successfully tested simultaneously as a machine manufacturer independent process monitoring setup: a high-frequency infrared camera and a camera for long time exposure, working in the visible and infrared spectrum and equipped with a near infrared filter. An AISI 316L stainless steel specimen with integrated artificial defects has been monitored during the build. The acquired camera data was compared to data obtained by computed tomography. A promising and easy to use examination method for data analysis was developed and correlations between measured signals and defects were identified. Moreover, sources of possible data misinterpretation were specified. Lastly, attempts for automatic data analysis by data integration are presented

PRIVACY-RELATED DECISION-MAKING IN THE CONTEXT OF WEARABLE USE

The widespread use of wearables for self-tracking activities despite potential privacy risks is an intriguing phenomenon. For firms, the data collected from individuals’ wearable use are highly valuable for generating in-depth customer insights. Accordingly, firms have an increasing desire for these data. Despite the undisputed relevance of self-tracking activities in practice, there is scarce knowledge among information systems (IS) scholars about the perceived values of wearables that drive individuals’ use and the reasons why these values prevail over the privacy risks. Against this background, our research set out to better understand why people use wearables despite privacy risks by investigating the perceived values of wearables that drive individuals’ use and disclosure of data and the reasons why these values prevail over privacy risks of wearable use. Based on the concept of the privacy calculus and concepts from behavioural decision-making, we conducted in-depth interviews with 22 wearable users from Switzerland. As a result, we reveal eight values that individuals perceive through the use of wearable devices. Furthermore, we illustrate the low awareness regarding privacy risks and explain how the reliance on prominent dimensions and heuristics are influencing individuals’ value-risk assessment

"Manchmal ist der Hang zu steil" : von Praktikantinnen und Praktikanten der Landschaftsstation

"Es ist noch kein Meister vom Himmel gefallen", sagt das Sprichwort, aber schon manch Praktikant oder Praktikantin der Landschaftsstation hat die Steilheit und Viskosität eines Kalkmagerrasen("KMR")-Hanges oder auch "nur" einer Waldrandfläche unterschätzt. Jan-Eric REITH aus Wrexen zum Beispiel, Dipl.-Agraringenieur mit Abschluss an der Rheinischen Friedrich-Wilhelms-Universität zu Bonn, sowie Praktikant der Landschaftsstation im Jahr 2008, "fiel" im Frühjahr von der "Waldrand"-Projektfläche an den Weserhängen "unterhalb des Nierenberges" bei Beverungen und freute sich, dass hangabwärts Bäume standen. So blieben nur blaue Flecken, die von der mitkartierenden Kollegin Vera GLANERT, Studentin an der Hochschule Ostwestfalen-Lippe - University of applied sciences im Studiengang "Landschaftsarchitektur", mit viel Mitgefühl begutachtet und versorgt wurden. Zum Glück ist es guter Brauch in Borgentreich, auch beim Kartieren die Praktikanten im "Doppelpack" einzusetzen. In der praktischen Landschaftspflege, d. h. beim Arbeiten mit Werkzeug und Maschinen, gehen Praktikanten, Zivildienstleistende, Ehrenamtliche und sonstige Naturschützer mindestens zu zweit auf die Fläche, so wie es Berufsgenossenschaft und Unfallversicherung vorsehen. Aber Kalkmagerrasen-Hänge sind nun mal meist sehr steil und lassen häufig nur spezielle selbst fahrende Maschinen zu, geschweige denn solche mit "Sitz", wie der damalige kaufmännische Leiter der Landschaftsstation und weiterhin hauptberufliche Geschäftsführer des Maschinenrings Warburg-Höxter, Norbert HOFNAGEL, bei einer Praxiserprobung feststellen musste: „Wie will man da Maschinen einsetzen oder überhaupt erst auf die Fläche bringen?“ Besagter Norbert HOFNAGEL und die Kollegen der Landschaftsstation haben dann später eine passende Maschine auch für jene Fläche gefunden: "Rapid" mit Schlegelmulcher, inzwischen beim Maschinenring zu mieten für die Pflege für den Naturschutz wertvoller Flächen. Freundlicher Förderer war die Nordrhein-Westfalen-Stiftung. Hauptnutzer ist bisher die Landschaftsstation im Kreis Höxter - Wen wundert's? Zurück zu den Hängen, die vom wissenschaftlichen Personal im "Alleingang" auf ihre Artenausstattung hin überwacht (wir sagen: "gemonitort"), betreut und kartiert werden, denn sonst würde die Arbeit ja nie fertig. Sie haben selbstverständlich zur Sicherheit ein Handy und im Auto einen Verbandskasten dabei, plus die Erfahrung im "Sich-nicht-wehtun". Aber weshalb waren Vera und Jan-Eric eigentlich am Nierenberg

Phosphorylation in liquid sulfur dioxide under prebiotically plausible conditions

In nature, organophosphates provide key functions such as information storage and transport, structural tasks, and energy transfer. Since condensations are unfavourable in water and nucleophilic attack at phosphate is kinetically inhibited, various abiogenesis hypotheses for the formation of organophosphate are discussed. Recently, the application of phosphites as phosphorylation agent showed promising results. However, elevated temperatures and additional reaction steps are required to obtain organophosphates. Here we show that in liquid sulfur dioxide, which acts as solvent and oxidant, efficient organophosphate formation is enabled. Phosphorous acid yields up to 32.6% 5′ nucleoside monophosphate, 3.6% 5′ nucleoside diphosphate, and the formation of nucleoside triphosphates and dinucleotides in a single reaction step at room temperature. In addition to the phosphorylation of organic compounds, we observed diserine formation. Thus, we suggest volcanic environments as reaction sites for biopolymer formation on Early Earth. Because of the simple recyclability of sulfur dioxide, the reaction is also interesting for synthesis chemistry

Fano interference in quantum resonances from angle-resolved elastic scattering

Asymmetric spectral line shapes are a hallmark of interference of a quasi-bound state with a continuum of states. Such line shapes are well known for multichannel systems, for example, in photoionization or Feshbach resonances in molecular scattering. On the other hand, in resonant single channel scattering, the signature of such interference may disappear due to the orthogonality of partial waves. Here, we show that probing the angular dependence of the cross section allows us to unveil asymmetric Fano profiles also in a single channel shape resonance. We observe a shift in the peak of the resonance profile in the elastic collisions between metastable helium and deuterium molecules with detection angle, in excellent agreement with theoretical predictions from full quantum scattering calculations. Using a model description for the partial wave interference, we can disentangle the resonant and background contributions and extract the relative phase responsible for the characteristic Fano-like profiles from our experimental measurements

Oral capecitabine in gemcitabine-pretreated patients with advanced pancreatic cancer

Objective: To date, no standard regimen for salvage chemotherapy after gemcitabine (Gem) failure has been defined for patients with advanced pancreatic cancer (PC). Oral capecitabine (Cap) has shown promising activity in first-line chemotherapy trials in PC patients. Methods: Within a prospective single-center study, Cap was offered to patients who had already received at least 1 previous treatment regimen containing full-dose Gem (as a single agent, as part of a combination chemotherapy regimen or sequentially within a chemoradiotherapy protocol). Cap was administered orally at a dose of 1,250 mg/m(2) twice daily for 14 days followed by 7 days of rest. Study endpoints were objective tumor response rate by imaging criteria (according to RECIST), carbohydrate antigen 19-9 (CA19-9) tumor marker response, time to progression, overall survival and toxicity. Results: A median of 3 treatment cycles (range 1-36) was given to 39 patients. After a median follow-up of 6.6 months, 27 patients were evaluable for response: no complete or partial responses were observed, but 15 patients (39%) had stable disease. A CA19-9 reduction of >20% after 2 cycles of Cap was documented in 6 patients (15%). Median time to progression was 2.3 months (range 0.5-45.1) and median overall survival (since start of Cap treatment) was 7.6 months (range 0.7-45.1). Predominant grade 2 and 3 toxicities (per patient analysis) were hand-foot syndrome 28% (13% grade 3); anemia 23%; leg edema 15%; diarrhea 13%; nausea/vomiting 10%, and leukocytopenia 10%. Conclusion: Single-agent Cap is a safe treatment option for Gem-pretreated patients with advanced PC. Further evaluation of Cap in controlled clinical trials of Gem-pretreated patients with advanced PC is recommended. Copyright (C) 2008 S. Karger AG, Basel

Isocyanide Multicomponent Reactions on Solid-Phase-Coupled DNA Oligonucleotides for Encoded Library Synthesis

Isocyanide multicomponent reactions play a prominent role in drug discovery. This chemistry has hardly been investigated for compatibility with DNA-encoded combinatorial synthesis. The Ugi, Ugi-azide, and Groebke-Blackburn-Bienaymé reactions are well-tolerated by DNA on the solid phase and show a broad scope. However, an oxadiazole-forming variant of the Ugi reaction caused DNA depurination, requiring a more stable hexathymidine DNA for encoded library synthesis. Cheminformatic analysis revealed that isocyanide multicomponent-reaction-based encoded libraries cover a diverse chemical space