414 research outputs found
A role of Schmidt-Lanterman Incisures for sustaining Schwann cell function in Charcot-Marie-Tooth Disease type 1A
No full textA role of Schmidt-Lanterman Incisures for sustaining Schwann cell function in Charcot-Marie-Tooth Disease type 1A
No full textWestwards component of ice surface velocity on the Greenland Ice Sheet measured in spring/summer 2012
No full textIce surface motion was recorded by five dual-frequency Leica SR520 GPS receivers deployed on poles drilled 2 m into the ice surface, within 700 m of Moulin L41A at 66.97N -49.27E. GPS data were post-processed kinematically (King, 2004, http://dx.doi.org/10.3189/172756504781829747) with Track v.1.27 software (Chen, 1998, Ph.D. thesis, Cambridge MA, USA) against bedrock-mounted reference stations using a precise ephemeris from the International GNSS Service )Dow et al., 2009, http://dx.doi.org/10.1007/s00190-008-0300-3). Reference stations were located 1 km from the terminus of Russell Glacier and at Kellyville, giving baseline lengths less than 41 km. Due to gaps in the time series caused by power outage, we averaged the horizontal velocities recorded at the five stations with the fewest gaps to give a single record. Positions were recorded at 30 s intervals; 1-hr means were then smoothed using a 5-point binomial filter. Since there was generally little difference in velocity between the stakes, the mean velocity across the network gives a better indication of the seasonal pattern of ice motion with fewer gaps than in the individual records. Velocities are centred differences of hourly displacements. GPS stakes required periodic re-drilling as they gradually melted out
Ice ablation record from the Greenland Ice Sheet measured in spring/summer 2012
No full textSurface ablation rates were measured daily using changes in ice surface height at five ablation stakes arranged in a cross configuration at ~2 m separation. The stakes were located in the supraglacial hydrological catchment feeding Moulin L41A. The stakes were installed in holes deeper than the length of the stake (so each measurement of ice surface height was made from the ice surface down to the top of the stake) to avoid the problem of enhanced surface melting caused by solar radiation absorbed by the stake. All ablation measurements were carried out by the same observer to ensure consistency for example in the interpretation of the level of a rough ice surface. A full description was provided by Chandler et al. (2015) at https://doi.org/10.5194/tc-9-487-2015
Author Correction: The NLR gene family: from discovery to present day
No full textAuthor Correction: The NLR gene family: from discovery to present da
Mobile computing in medical and healthcare industry
No full textWe believe the specific development of applications for mobile devices is the most important issue for ensuring the integration of mobile computing within the medical industry. This must reflect the individual device design and the individual user groups
FACT - Highlights from more than Five Years of Unbiased Monitoring at TeV Energies
No full textThe First G-APD Cherenkov Telescope (FACT) is monitoring blazars at TeV energies. Thanks to the observing strategy, the automatic operation and the usage of solid state photosensors (SiPM, aka G-APDs), the duty cycle of the instrument has been maximized and the observational gaps minimized. This provides a unprecedented, unbiased data sample of almost 9000~hours of data of which 2375 hours were taken in 2016. An automatic quick look analysis provides results with low latency on a public website. More than 40 alerts have been sent in the last three years based on this. To study the origin of the very high energy emission from blazars simultaneous multi-wavelength and multi-messenger observations are crucial to draw conclusions on the underlying emission mechanisms, e.g. to distinguish between leptonic and hadronic models. FACT not only participates in multi-wavelength studies, correlation studies with other instruments and multi-messenger studies, but also collects time-resolved spectral energy distributions using a target-of-opportunity program with X-ray satellites. At TeV energies, FACT provides an unprecedented, unbiased data sample. Using up to 1850 hours per source, the duty cycle of the sources and the characteristics of flares at TeV energies are studied. In the presentation, the highlights from more than five years of monitoring will be summarized including several flaring activities of Mrk 421, Mrk 501 and 1ES 1959+650.D. Dorner, J. Adam, M.L. Ahnen, D. Baack, M. Balbo, A. Biland, M. Blank, T. Bretz, a, K. Bruegge, M. Bulinski, J. Buss, A. Dmytriiev, S. Einecke, D. Elsaesser, C. Hempfling, T. Herbst, D. Hildebrand, L. Kortmann, L. Linhoff, M. Mahlke, a, K. Mannheim, S.A. Mueller, D. Neise, A. Neronov, M. Noethe, J. Oberkirch, A. Paravac, F. Pauss, W. Rhode, B. Schleicher, F. Schulz, A. Shukla, V. Sliusar, F. Temme, J. Thaele, R. Walte
FACT - Time-resolved blazar SEDs
No full textBlazars are highly variable objects and their spectral energy distribution (SED) features two peaks. The emission at low energies is understood, however, the origin of the emission at TeV energies is strongly debated. While snapshots of SEDs usually can be explained with simple models, the evolution of SEDs challenges many models and allows for conclusions on the emission mechanisms. Leptonic models expect a correlation between the two peaks, while hadronic models can accommodate more complex correlations. To study time-resolved SEDs, we set up a target-of-opportunity program triggering high-resolution X-ray observations based on the monitoring at TeV energies by the First G-APD Cherenkov Telescope (FACT). To search for time lags and identify orphan flares, this is accompanied by X-ray monitoring with the Swift satellite. These observations provide an excellent multi-wavelength (MWL) data sample showing the temporal behaviour of the blazar emission along the electromagnetic spectrum. To constrain the origin of the TeV emission, we extract the temporal evolution of the low energy peak from Swift data and calculate the expected flux at TeV energies using a theoretical model. Comparing this to the flux measured by FACT, we want to conclude on the underlying physics. Results from more than five years of monitoring will be discussed.D. Dorner, J. Adam, M.L. Ahnen, D. Baack, M. Balbo, A. Biland, M. Blank, T. Bretz, a, K. Bruegge, M. Bulinski, J. Buss, A. Dmytriiev, S. Einecke, D. Elsaesser, C. Hempfling, T. Herbst, D. Hildebrand, L. Kortmann, L. Linhoff, M. Mahlke, a, K. Mannheim, S.A. Mueller, D. Neise, A. Neronov, M. Noethe, J. Oberkirch, A. Paravac, F. Pauss, W. Rhode, B. Schleicher, F. Schulz, A. Shukla, V. Sliusar, F. Temme, J. Thaele, R. Walter, FACT Collaboration, A. Kreikenbohm, K. Leite
Single photon extraction for FACT's SiPMs allows for novel IACT event representation
No full textImaging Atmospheric Cherenkov Telescopes provide large gamma-ray collection areas > 104 m2 and successfully probe the high energetic gamma-ray sky by observing extensive air-showers during the night. The First G-APD Cherenkov Telescope (FACT) explores silicon based photoelectric converters (called G-APDs or SiPMs) which provide more observation time with strong moonlight, a more stable photon gain over years of observations, and mechanically simpler imaging cameras. So far, the signal extraction methods used for FACT originate from sensors with no intrinsic quantized responses like photomultiplier tubes. This standard signal extraction is successfully used for the long time monitoring of the gamma-ray flux of bright blazars. However, we now challenge our classic signal extraction and explore single photon extraction methods to take advantage of the highly stable and quantized single photon responses of FACT’s SiPM sensors. Instead of having one main pulse with one arrival time and one photon equivalent extracted for each pixel, we extract the arrival times of all individual photons in a pixel’s time line which opens up a new dimension in time for representing extensive air-showers with an IACT.S. A. Mueller, J. Adam, M. L. Ahnen, D. Baack, M. Balbo, A. Biland, M. Blank, T. Bretz, K. Bruegge, J. Buss, A. Dmytriiev, D. Dorner, S. Einecke, D. Elsaesser, C. Hempfling, T. Herbst, D. Hildebrand, L. Kortmann, L. Linhoff, M. Mahlke, K. Mannheim, D. Neise, A. Neronov, M. Noethe, J. Oberkirch, A. Paravac, F. Pauss, W. Rhode, B. Schleicher, F. Schulz, A. Shukla, V. Sliusar, F. Temme, J. Thaele, R. Walte
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