3,251 research outputs found

    The 64 Mpixel wide field imager for the Wendelstein 2m Telescope: Design and Calibration

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    The Wendelstein Observatory of Ludwig Maximilians University of Munich has recently been upgraded with a modern 2m robotic telescope. One Nasmyth port of the telescope has been equipped with a wide-field corrector which preserves the excellent image quality (< 0.8" median seeing) of the site (Hopp et al. 2008) over a field of view of 0.7 degrees diameter. The available field is imaged by an optical imager (WWFI, the Wendelstein Wide Field Imager) built around a customized 2 ×\times 2 mosaic of 4k ×\times 4k 15 \mu m e2v CCDs from Spectral Instruments. This paper provides an overview of the design and the WWFI's performance. We summarize the system mechanics (including a structural analysis), the electronics (and its electromagnetic interference (EMI) protection) and the control software. We discuss in detail detector system parameters, i.e. gain and readout noise, quantum efficiency as well as charge transfer efficiency (CTE) and persistent charges. First on sky tests yield overall good predictability of system throughput based on lab measurements.Comment: 38 pages 19 Figures To be published in Springer Experimental Astronom

    A Glance into the Tunnel: Experimental Evidence of Expectations Versus Comparison Considerations

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    Learning that others earn more may reduce individual well-being but can also be informative about the own income prospects. This paper provides experimental evidence that separates direct effects of income comparisons on well-being and informational effects from observing changes in the income of others. In an environment of uncertainty about the own income we find that both the direct comparison effects and the informational effects are asymmetric. Individual beliefs about the own income are adjusted downwards when observing that others are likely to earn less but do not change significantly when observing that others are likely to earn more. Individual satisfaction decreases when observing that others are likely to earn more but does not change significantly when observing that others are likely to earn less. Overall, individuals are more reactive to bad news than to good news

    Heterotrimeric G-protein subunit Gαi2 contributes to agonist-sensitive apoptosis and degranulation in murine platelets

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    Gαi2, a heterotrimeric G-protein subunit, regulates various cell functions including ion channel activity, cell differentiation, proliferation and apoptosis. Platelet-expressed Gαi2 is decisive for the extent of tissue injury following ischemia/reperfusion. However, it is not known whether Gαi2 plays a role in the regulation of platelet apoptosis, which is characterized by caspase activation, cell shrinkage and cell membrane scrambling with phosphatidylserine (PS) translocation to the platelet surface. Stimulators of platelet apoptosis include thrombin and collagen-related peptide (CoRP), which are further known to enhance degranulation and activation of αII bβ3-integrin and caspases. Using FACS analysis, we examined the impact of agonist treatment on activation and apoptosis in platelets drawn from mice lacking Gαi2 and their wild-type (WT) littermates. As a result, treatment with either thrombin (0.01 U/mL) or CoRP (2 μg/mL or 5 μg/mL) significantly upregulated PS-exposure and significantly decreased forward scatter, reflecting cell size, in both genotypes. Exposure to CoRP triggered a significant increase in active caspase 3, ceramide formation, surface P-selectin, and αII bβ3-integrin activation. These molecular alterations were significantly less pronounced in Gαi2-deficient platelets as compared to WT platelets. In conclusion, our data highlight a previously unreported role of Gαi2 signaling in governing platelet activation and apoptosis.Fil: Cao, Hang. Universität Tübingen; AlemaniaFil: Qadri, Syed M.. Canadian Blood Services; Canadá. McMaster University; CanadáFil: Lang, Elisabeth. Heinrich-heine-universität Düsseldorf; AlemaniaFil: Pelzl, Lisann. Universität Tübingen; AlemaniaFil: Umbach, Anja T.. Universität Tübingen; AlemaniaFil: Leiss, Veronika. Universität Tübingen; AlemaniaFil: Birnbaumer, Lutz. National Institutes of Health; Estados Unidos. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Nürnberg, Bernd. Universität Tübingen; AlemaniaFil: Pieske, Burkert. Berlin Institute of Health; Alemania. Universitätsmedizin Berlin; AlemaniaFil: Voelkl, Jakob. Berlin Institute of Health; Alemania. Universitätsmedizin Berlin; AlemaniaFil: Gawaz, Meinrad. Universität Tübingen; AlemaniaFil: Bissinger, Rosi. Universität Tübingen; AlemaniaFil: Lang, Florian. Universität Tübingen; Alemania. Heinrich-heine-universität Düsseldorf; Alemani

    Hyperfine, rotational, and vibrational structure of the triplet ground state of Rb molecules

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    We have performed high-resolution two-photon dark-state spectroscopy of an ultracold gas of Rb molecules in the triplet ground state at a magnetic field of about 1000 G. The vibrational ladder as well as the hyperfine and low-lying rotational structure is mapped out. Energy shifts in the spectrum are observed due to singlet-triplet mixing at binding energies as deep as a few hundred GHz x h. This information together with data from other sources is used to optimize the potentials of the triplet and singlet states in a coupled-channel model. We find that the hyperfine structure depends weakly on the vibrational level. This provides a possible explanation for inaccuracies in recent Feshbach resonance calculations

    Meyer's surgical procedure for the treatment of lip carcinoma

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    Lip carcinomas are generally treated by surgery. A reconstruction is often required if the resected segment exceeds one-third of the lip. Meyer's plasty is an alternate way of reconstructing the lower or upper lip. The aim of this study is to describe the technique, its indications and results. A retrospective review of all patients who underwent a Meyer's plasty in our institution is presented. Twenty-four consecutive patients were treated in Lausanne for T1 and T2 lip carcinomas between 1983 and 2001. Primary surgery associated with Meyer's plasty was performed in all cases. Data were collected from the medical records, and eight patients were recalled for clinical evaluation. The oncological, functional and aesthetic results were analyzed. The 5-year local control was 100%. Three patients developed metachronous lymph node metastasis. No patient died from the disease. A hindering microstomy was found in three cases, and two patients suffered from temporary oral leakage. No speech difficulty was encountered. The aesthetics was described as satisfying or good in 87% of the patients. Meyer's plasty following lip surgery of the upper or lower lip allows an aesthetic and functional one-stage reconstruction without compromising the oncological outcom

    Surgical management of laryngotracheal stenosis in adults

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    The purpose was to evaluate the outcome following the surgical management of a consecutive series of 26 adult patients with laryngotracheal stenosis of varied etiologies in a tertiary care center. Of the 83 patients who underwent surgery for laryngotracheal stenosis in the Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Lausanne, Switzerland, between 1995 and 2003, 26 patients were adults (≥16years) and formed the group that was the focus of this study. The stenosis involved the trachea (20), subglottis (1), subglottis and trachea (2), glottis and subglottis (1) and glottis, subglottis and trachea (2). The etiology of the stenosis was post-intubation injury ( n =20), infiltration of the trachea by thyroid tumor ( n =3), seeding from a laryngeal tumor at the site of the tracheostoma ( n =1), idiopathic progressive subglottic stenosis ( n =1) and external laryngeal trauma ( n =1). Of the patients, 20 underwent tracheal resection and end-to-end anastomosis, and 5 patients had partial cricotracheal resection and thyrotracheal anastomosis. The length of resection varied from 1.5 to 6cm, with a median length of 3.4cm. Eighteen patients were extubated in the operating room, and six patients were extubated during a period of 12 to 72h after surgery. Two patients were decannulated at 12 and 18months, respectively. One patient, who developed anastomotic dehiscence 10days after surgery, underwent revision surgery with a good outcome. On long-term outcome assessment, 15 patients achieved excellent results, 7 patients had a good result and 4 patients died of causes unrelated to surgery (mean follow-up period of 3.6years). No patient showed evidence of restenosis. The excellent functional results of cricotracheal/tracheal resection and primary anastomosis in this series confirm the efficacy and reliability of this approach towards the management of laryngotracheal stenosis of varied etiologies. Similar to data in the literature, post-intubation injury was the leading cause of stenosis in our series. A resection length of up to 6cm with laryngeal release procedures (when necessary) was found to be technically feasibl

    Long Distance Transport of Ultracold Atoms using a 1D optical lattice

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    We study the horizontal transport of ultracold atoms over macroscopic distances of up to 20 cm with a moving 1D optical lattice. By using an optical Bessel beam to form the optical lattice, we can achieve nearly homogeneous trapping conditions over the full transport length, which is crucial in order to hold the atoms against gravity for such a wide range. Fast transport velocities of up to 6 m/s (corresponding to about 1100 photon recoils) and accelerations of up to 2600 m/s2 are reached. Even at high velocities the momentum of the atoms is precisely defined with an uncertainty of less than one photon recoil. This allows for construction of an atom catapult with high kinetic energy resolution, which might have applications in novel collision experiments.Comment: 15 pages, 8 figure
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