883 research outputs found

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    Multipole Analysis of Kicks in Collision of Binary Black Holes

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    Thorne and Kidder give expressions which allow for analytical estimates of the "kick", it i.e. the recoil, produced from asymmetrical gravitational radiation during the interaction of black holes, or in fact any gravitating compact bodies. (The Thorne-Kidder formula uses momentum flux calculations based on the linearized General Relativity of gravitational radiation.) We specifically treat kicks arising in the binary interaction of equal mass black holes, when at least one of the black holes has significant spin, a. Such configurations can produce very large kicks in computational simulations. We consider both fly-by and quasicircular orbits. For fly-by orbits we find substantial kicks from those Thorne-Kidder terms which are linear in a. For the quasi-circular case, we consider in addition the nonlinear contribution (O(a^2)) to the kicks, and provide a dynamical explanation for such terms. However, in the cases of maximal kick velocities, the dependence on spin is largely linear (reproduced in numerical results).Comment: 14 pages, 2 figures. Version 2: Title refined, slight wording and typo changes, new reference. Version 3: Version in press at General relativity and Gravitatio

    Hildesheimer Geographische Studien, Band 5

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    In diesem Band enthalten: Hannah Graen, Robin Stadtmann & Martin Sauerwein: Modellierung von Temperaturdaten und Temperaturveränderungen im Nationalpark Asinara, Sardinien (S. 1-27); Sarah Matheis, Nico Herrmann & Martin Sauerwein: Entwicklung eines Monitoringkonzeptes für Niedermoore am Beispiel des Bergen-Weißacker Moores, Süd-Brandenburg (S. 28-63); Martin Sauerwein, Jan-Philip Dieck & Robin Stadtmann: Urbane Böden im Kontext von Ecosystem Services (S. 64-89); Martin Sauerwein, Julia Jaquemotte & Lars Germershausen: Ursachen der Nitratbelastung des Grundwassers im Raum Hannover/Hildesheim (S. 90-110); Sabine Panzer-Krause: Einkaufen in der Hildesheimer Innenstadt. Auswirkungen der Arneken Galerie auf den innerstädtischen Einzelhandel (S. 111-132); Robin Stadtmann, Nico Herrmann, Jasmin Karaschewski & Martin Sauerwein: Bodenbewusstsein: Hildesheimer Aktivitäten zum Jahr des Bodens 2015 (S. 133-140

    Characterization of fluorescent proteins with intramolecular photostabilization

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    Genetically encodable fluorescent proteins have revolutionized biological imaging in vivo and in vitro. Since there are no other natural fluorescent tags with comparable features, the impact of fluorescent proteins for biological research cannot be overemphasized. Despite their importance, their photophysical properties, i.e., brightness, count-rate and photostability, are relatively poor compared to synthetic organic fluorophores or quantum dots. Intramolecular photostabilizers were recently rediscovered as an effective approach to improve photophysical properties. The approach uses direct conjugation of photostablizing compounds such as triplet-state quenchers or redox-active substances to an organic fluorophore, thereby creating high local concentrations of photostabilizer. Here, we introduce an experimental strategy to screen for the effects of covalently-linked photostabilizers on fluorescent proteins. We recombinantly produced a double cysteine mutant (A206C/L221C) of α-GFP for attachment of photostabilizer-maleimides on the ß-barrel in close proximity to the chromophore. Whereas labelling with photostabilizers such as Trolox, Nitrophenyl, and Cyclooctatetraene, which are often used for organic fluorophores, had no effect on α-GFP-photostability, a substantial increase of photostability was found upon conjugation of α-GFP to an azobenzene derivative. Although the mechanism of the photostabilizing effects remains to be elucidated, we speculate that the higher triplet-energy of azobenzene might be crucial for triplet-quenching of fluorophores in the near-UV and blue spectral range. Our study paves the way towards the development and design of a second generation of fluorescent proteins with photostabilizers placed directly in the protein barrel by methods such as unnatural amino acid incorporation

    A blinded, randomized, controlled trial assessing conservative management strategies for frozen shoulder

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    BACKGROUND: There is little evidence for the optimal form of nonoperative treatment in the management of frozen shoulder. This study assesses the efficacy of current physiotherapy strategies. METHODS: All primary care referrals of frozen shoulder to our physiotherapy department were included during a 12-month period. Of these referrals, 17% met the inclusion criteria for primary idiopathic frozen shoulder. The 75 patients were randomly assigned to 1 of 3 groups: group exercise class, individual physiotherapy, and home exercises alone. A single independent physiotherapist, who was blinded to the treatment groups, made all assessments. Range of motion, Constant score, Oxford Shoulder Score, Short Form 36, and Hospital Anxiety and Disability Scale (HADS) outcome measures were performed at baseline, 6 weeks, 6 months, and 1 year. RESULTS: The exercise class group improved from a mean Constant score of 39.8 at baseline to 71.4 at 6 weeks and 88.1 at 1 year. There was a significant improvement in shoulder symptoms on Oxford and Constant scores (P < .001). This improvement was greater than with individual physiotherapy or home exercises alone (P < .001). The improvement in range of motion was significantly greater in both physiotherapy groups over home exercises (P < .001). HADS scores significantly improved during the course of treatment (P < .001). The improvement in HADS anxiety score was significantly greater in both physiotherapy intervention groups than in home exercises alone. CONCLUSIONS: A hospital-based exercise class can produce a rapid recovery from a frozen shoulder with a minimum number of visits to the hospital and is more effective than individual physiotherapy or a home exercise program
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