Three-Dimensional Software- and MR-Imaging-Based Muscle Volumetry Reveals Overestimation of Supraspinatus Muscle Atrophy Using Occupation Ratios in Full-Thickness Tendon Tears

Supraspinatus muscle atrophy is widely determined from oblique-sagittal MRI by calculating the occupation ratio. This ex vivo and clinical study aimed to validate the accuracy of 3D software- and MR-imaging-based muscle volumetry, as well as to assess the influence of the tear pattern on the occupation ratio. Ten porcine muscle specimens were volumetrized using the physical water displacement volumetry as a standard of reference. A total of 149 individuals with intact supraspinatus tendons, partial tears, and full-thickness tears had 3T MRI. Two radiologists independently determined occupation ratio values. An excellent correlation with a Pearson's r of 0.95 for the variables physical volumetry using the water displacement method and MR-imaging-based muscle volumetry using the software was found and formed the standard of reference for the patient study. The inter-reader reliability was 0.92 for occupation ratios. The correlation between occupation ratios and software-based muscle volumes was good in patients with intact tendons (0.84) and partial tears (0.93) but considerably lower in patients with full-thickness tears (0.68). Three-dimensional-software- and MR-imaging-based muscle volumetry is reliable and accurate. Compared to 3D muscle volumetry, the occupation ratio method overestimates supraspinatus muscle atrophy in full-thickness tears, which is most likely due to the medial retraction of the myotendinous unit

Large-scale mapping of mutations affecting zebrafish development

BACKGROUND: Large-scale mutagenesis screens in the zebrafish employing the mutagen ENU have isolated several hundred mutant loci that represent putative developmental control genes. In order to realize the potential of such screens, systematic genetic mapping of the mutations is necessary. Here we report on a large-scale effort to map the mutations generated in mutagenesis screening at the Max Planck Institute for Developmental Biology by genome scanning with microsatellite markers. RESULTS: We have selected a set of microsatellite markers and developed methods and scoring criteria suitable for efficient, high-throughput genome scanning. We have used these methods to successfully obtain a rough map position for 319 mutant loci from the Tübingen I mutagenesis screen and subsequent screening of the mutant collection. For 277 of these the corresponding gene is not yet identified. Mapping was successful for 80 % of the tested loci. By comparing 21 mutation and gene positions of cloned mutations we have validated the correctness of our linkage group assignments and estimated the standard error of our map positions to be approximately 6 cM. CONCLUSION: By obtaining rough map positions for over 300 zebrafish loci with developmental phenotypes, we have generated a dataset that will be useful not only for cloning of the affected genes, but also to suggest allelism of mutations with similar phenotypes that will be identified in future screens. Furthermore this work validates the usefulness of our methodology for rapid, systematic and inexpensive microsatellite mapping of zebrafish mutations

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Towards a Reusable First Stage Demonstrator: CALLISTO - Technical Progresses & Challenges

In order to investigate the capabilities of a reusable launch system, JAXA, CNES and DLR have jointly initiated the project CALLISTO ("Cooperative Action Leading to Launcher Innovation for Stage Toss-back Operations"). The goal of this cooperation is to launch, recover and reuse a first stage demonstrator to increase the maturity of technologies necessary for future operational reusable launch vehicles (RLV) and to build up know-how on such vehicles under operational and developmental aspects. As the project has now turned into the detailed design phase, significant technical progresses have been made in definition, analysis and testing of systems and subsystems. The CALLISTO vehicle itself constitutes a subscale vertical take-off vertical landing (VTVL) stage with an overall length of 13.5 m and a take-off mass of less than 4 tons, which is propelled by a throttleable LOX/LH2 engine. It is capable to perform up to 10 consecutive flights during the planned flight campaign in French Guiana. Globally, the development effort on this system is equally shared between the three project partners. This paper presents the recent achievements in development of the key technologies for the reusable launch vehicle. While the design of critical subsystems has reached PDR level, detailed analyses and first breadboard tests have been performed successfully. These results are presented and discussed within the perimeter of the CALLISTO development roadmap. Possible technical challenges are indicated and their resolution methods are examined. Finally, the upcoming development steps are described which are foreseen to move forward to the qualification and maiden flight campaign

Absolute energy calibration of the Pierre Auger observatory using radio emission of extensive air showers

Ultra-high-energy cosmic rays can be measured by short radio pulses in the MHz regime emitted by extensive air showers. This radio technique is complementary to existing techniques such as surface detector arrays or fluorescence telescopes. It has a duty cycle of almost 100% and is sensitive to all main air-shower observables such as the cosmic-ray energy, mass, and arrival direction. In this thesis, we developed a new method to determine the cosmic-ray energy. We showed that the radio technique is especially useful to determine the cosmic-ray energy with high accuracy and is superior to existing techniques in term of achievable accuracy. This is because the radio emission from air showers can be calculated from first principles, and radio waves are less influenced by environmental conditions compared to, e.g., fluorescence light. As an accurate energy scale is crucial for the interpretation of cosmic-ray measurements, the radio technique will thus be able to significantly advance this field of research. We first studied the energy released in air showers in the form of MHz radiation in detail, using CoREAS air-shower simulations. Depending on the distance between the observer and the region in the atmosphere where the radiation is released, the shape of the signal distribution on the ground changes significantly. For small distances to the emission region, the signal distribution is narrow around the shower axis with large energies per unit area, whereas for large distances to the emission region the radiation energy is distributed over a larger area resulting in a broad signal distribution with a small amount of energy per unit area. As soon as the air shower has emitted all its radiation energy, the total radiation energy, i.e., the integral over the signal distribution on the ground, remains constant. In particular, it does not depend on the spacial signal distribution on the ground or on the observation altitude and is thus directly comparable between different experiments.The simulated radiation energy – corrected for the dependence on the geomagnetic field – correlates best with the energy contained in the electromagnetic part of the air shower and exhibits quadratic scaling with the electromagnetic shower energy, as is expected for coherent emission. The electromagnetic shower energy can be converted to the primary cosmic-ray energy using predictions from hadronic interaction models or a direct measurement of the invisible energy fraction alternatively.The simulated radiation energy has a second-order dependency on the air density of the emission region. After correcting this effect, the corrected radiation energy and the electromagnetic shower energy have a scatter of less than 3%. In addition, we presented a more practical parametrization of the dependence between radiation energy and electromagnetic shower energy using only the geometry of the air shower, i.e., without using Xmax information, and obtained a resolution of 4%. This scatter of 4% is well below current experimental uncertainties, so that the radiation energy is well suited to estimate the cosmic-ray energy.If the radiation energy is detected at a particular observation height, the air shower may not have released all its radiation energy. The strength of this clipping effect depends on the atmospheric depth between observation height and shower maximum. We presented a parametrization of this effect that can be used in experiments to correctly determine the full radiation energy and thereby estimate the cosmic-ray energy. The radiation energy is influenced less by clipping than the electromagnetic part of the air shower as the radiation energy is released earlier in the shower development.Then, we used data from the Auger Engineering Radio Array (AERA) which is the radio detector of the Pierre Auger Observatory. AERA is located within the low-energy extension of the Observatory where additional surface detector stations with a smaller spacing are present, which enables access to cosmic-ray energies down to 0.1 EeV. To most accurately determine the cosmic-ray energy, we only use the thoroughly calibrated 24 LPDA radio stations of the first stage of AERA deployment, with data collected between April 2011 and March 2013. At several observer positions, the energy deposit per area of the radio pulse of an extensive air shower is measured. Using recent progress in understanding the lateral signal distribution of the radio signals, this distribution is described by an empirical function. The spatial integral of the lateral distribution function gives the amount of energy that is transferred from the primary cosmic ray into radio emission in the 30 to 80 MHz frequency band of AERA during the air-shower development. We measured on average 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to a geomagnetic field of 0.24 G. The systematic uncertainty is 28% on the radiation energy and 16% on the cosmic-ray energy.Using the results from the simulation study, the radiation energy is corrected for different emission strengths at different angles between shower axis and geomagnetic field, for changing emission strengths due to different air densities in the emission region as well as for missing radiation energy of air showers that are not fully developed before reaching the ground. This corrected radiation energy is compared with the calorimetric air-shower energy obtained from the the surface-detector reconstruction. Investigating the scatter around the calibration curve and subtracting the resolution of the surface detector we found that the energy resolution of the radio detector is 20% for the full data set, and 14% for the events with more than four stations with signal, where the core position could be determined in the radio LDF fit. Given the small shower-to-shower fluctuations of the electromagnetic component, we expect that with a deeper understanding of the detector and environmental effects, an even improved precision of the energy measurement can be achieved.The first-principles calculations are compared to the measurement of the radiation energy with respect to the energy scale of the fluorescence detector (FD). We found that the first-principles calculations predict 19% larger cosmic-ray energies than given by the FD energy scale at energies around 1 EeV. The systematic uncertainty of the radio energy scale is 15% and is dominated by the detector calibration that contributes with 14%. Hence, the radio technique is well competitive to the fluorescence technique with its systematic uncertainty of 14% at energies above 1 EeV and 16% at energies of around 0.3 EeV. In particular, the difference in the energy scales is well compatible within the systematic uncertainties. In the future, a significant improvement in the systematic uncertainty of the radio energy scale is expected. Using the results of a recently performed calibration campaign of the antenna response, the total systematic uncertainty can be reduced to 10%. With further improvements in the antenna calibration and more detailed first-principles calculations, a reduction of the uncertainty to 7% or below seems realistic. Hence, the radio technique together with the methods developed in this thesis can deliver unprecedented accuracy of the cosmic-ray energy scale. This will allow for a significant improvement in the interpretation of the results of the Pierre Auger Observatory