2,015 research outputs found

    Scientific Highlights from Observations of Active Galactic Nuclei with the MAGIC Telescope

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    Since 2004, the MAGIC gamma-ray telescope has newly discovered 6 TeV blazars. The total set of 13 MAGIC-detected active galactic nuclei includes well-studied objects at other wavelengths like Markarian 501 and the giant radio galaxy M87, but also the distant the flat-spectrum radio quasar 3C 279, and the newly discovered TeV gamma-ray emitter S5 0716+71. In addition, also long-term and multi-wavelength studies on well-known TeV blazars and systematic searches for new TeV blazars have been carried out. Here we report selected highlights from recent MAGIC observations of extragalactic TeV gamma-ray sources, emphasizing the new physics insights MAGIC was able to contribute.Comment: 4 pages, 2 figures, submitted to proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008

    Noise Efficient Integrated Amplifier Designs for Biomedical Applications

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    The recording of neural signals with small monolithically integrated amplifiers is of high interest in research as well as in commercial applications, where it is common to acquire 100 or more channels in parallel. This paper reviews the recent developments in low-noise biomedical amplifier design based on CMOS technology, including lateral bipolar devices. Seven major circuit topology categories are identified and analyzed on a per-channel basis in terms of their noise-efficiency factor (NEF), input-referred absolute noise, current consumption, and area. A historical trend towards lower NEF is observed whilst absolute noise power and current consumption exhibit a widespread over more than five orders of magnitude. The performance of lateral bipolar transistors as amplifier input devices is examined by transistor-level simulations and measurements from five different prototype designs fabricated in 180 nm and 350 nm CMOS technology. The lowest measured noise floor is 9.9 nV/√Hz with a 10 ”A bias current, which results in a NEF of 1.2

    Free-living flatworms under the knife: past and present

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    Traditionally, regeneration research has been closely tied to flatworm research, as flatworms (Plathelminthes) were among the first animals where the phenomenon of regeneration was discovered. Since then, the main focus of flatworm regeneration research was on triclads, for which various phenomena were observed and a number of theories developed. However, free-living flatworms encompass a number of other taxa where regeneration was found to be possible. This review aims to display and to compare regeneration in all major free-living flatworm taxa, with special focus on a new player in the field of regeneration, Macrostomum lignano (Macrostomorpha). Findings on the regeneration capacity of this organism provide clues for links between regeneration and (post-)embryonic development, starvation, and asexual reproduction. The role of the nervous system and especially the brain for regeneration is discussed, and similarities as well as particularities in regeneration among free-living flatworms are pointed out

    Investigation of a Folding Intermediate of RNase H Using Single Molecule FRET Spectroscopy

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    FRET studies were performed on freely diffusing RNase H molecules at pH 7.2 and ph 3.0. The application of ALEX and PIE illumination and detection schemes allowed the accumulation of donor-only free smFRET data with excellent statistics. By imposing physically sensible global restrictions on the fit of the data, an intermediate folding state can be observed and characterized

    Affordance-Experimentation-Actualization Theory in Artificial Intelligence Research – A Predictive Maintenance Story

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    Artificial intelligence currently counts among the most prominent digital technologies and promises to generate significant business value in the future. Despite a growing body of knowledge, research could further benefit from incorporating technological features, human actors, and organizational goals into the examination of artificial intelligence-enabled systems. This integrative perspective is crucial for effective implementation. Our study intends to fill this gap by introducing affordance-experimentation-actualization theory to artificial intelligence research. In doing so, we conduct a case study on the implementation of predictive maintenance using affordance-experimentation-actualization theory as our theoretical lens. From our study, we find further evidence for the existence of the experimentation phase during which organizations make new technologies ready for effective use. We propose extending the experimentation phase with the activity of ‘conceptual exploration’ in order to make affordance-experimentation-actualization theory applicable to a broader range of technologies and the domain of AI-enabled systems in particular

    Introduction to the Special Issue on Biomedical and Bioelectronic Circuits for Enhanced Diagnosis and Therapy

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    The 22 papers in this special issue focus on biomedical and biolectronic circuits for enhanced diagnosis and therapy
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