145 research outputs found
The German Aerospace Center M-42 radiation detector—A new development for applications in mixed radiation fields
In the last few years, the Biophysics Working Group of the Institute of Aerospace Medicine of the German Aerospace Center (DLR) started
the development of a small low power consumption radiation detector system for the measurement of the absorbed dose to be applied in
various environments, such as onboard aircraft, in space, and also as a demonstration tool for students. These so called DLR M-42 detectors
are based on an electronics design, which can easily be adjusted to the user- and mission-requirements. M-42 systems were already applied
for measurements in airplanes, during two MAPHEUS (Materialphysikalische Experimente unter Schwerelosigkeit) rocket missions, and
are currently prepared for long term balloon experiments. In addition, they will be part of the dosimetry suite of the upcoming Matroshka
AstroRad Radiation Experiment on the NASA Artemis I mission. This paper gives an overview of the design and the testing of the DLR M-42
systems and provides highlighted results from the MAPHEUS campaigns where the detectors were tested for the first time under space flight
conditions. Results clearly show that the system design enables independent measurements starting upon rocket launch due to the built-in
accelerometer sensors and provides data for the relevant 6 min of μ-gravity as given for the MAPHEUS missions. These 6 min of the μ-gravity
environment at altitudes between 100 and 240 km lead to a total absorbed dose of 1.21 ± 0.15 μGy being equivalent to half a day of radiation
background measured with the M-42 in the laboratory at DLR, Cologne, Germany
Measuring Cosmic Rays with the RadMap Telescope on the International Space Station
The RadMap Telescope is a new radiation-monitoring instrument operating in the U.S. Orbital
Segment (USOS) of the International Space Station (ISS). The instrument was commissioned in
May 2023 and will rotate through four locations inside American, European, and Japanese modules
over a period of about six months. In some locations, it will take data alongside operational,
validated detectors for a cross-check of measurements. RadMap’s central detector is a finely
segmented tracking calorimeter that records detailed depth-dose data relevant to studies of the
radiation exposure of the ISS crew. It is also able to record particle-dependent energy spectra of
cosmic-ray nuclei with energies up to several hundred MeV per nucleon. A unique feature of the
detector is its ability to track nuclei with omnidirectional sensitivity at an angular resolution of two
degrees. In this contribution, we present the design and capabilities of the RadMap Telescope and
give an overview of the instrument’s commissioning on the ISS
New AMS 14C dates track the arrival and spread of broomcorn millet cultivation and agricultural change in prehistoric Europe
Broomcorn millet (Panicum miliaceum L.) is not one of the founder crops domesticated in Southwest Asia in the early Holocene, but was domesticated in northeast China by 6000 bc. In Europe, millet was reported in Early Neolithic contexts formed by 6000 bc, but recent radiocarbon dating of a dozen 'early' grains cast doubt on these claims. Archaeobotanical evidence reveals that millet was common in Europe from the 2nd millennium bc, when major societal and economic transformations took place in the Bronze Age. We conducted an extensive programme of AMS-dating of charred broomcorn millet grains from 75 prehistoric sites in Europe. Our Bayesian model reveals that millet cultivation began in Europe at the earliest during the sixteenth century bc, and spread rapidly during the fifteenth/fourteenth centuries bc. Broomcorn millet succeeds in exceptionally wide range of growing conditions and completes its lifecycle in less than three summer months. Offering an additional harvest and thus surplus food/fodder, it likely was a transformative innovation in European prehistoric agriculture previously based mainly on (winter) cropping of wheat and barley. We provide a new, high-resolution chronological framework for this key agricultural development that likely contributed to far-reaching changes in lifestyle in late 2nd millennium bc Europe
Orion EM-1 Internal Environment Characterization: The Matroshka AstroRad Radiation Experiment
Presentation Outline: Orion Multipurpose Crew Vehicle (MPCV); Radiation Vest for Astronauts - AstroRad; ISS (International Space Station) Matroshka; Matroshka AstroRad Radiation Experiment (MARE) on Exploration Mission 1 (EM-1)
Improving the iMM904 S. cerevisiae metabolic model using essentiality and synthetic lethality data
<p>Abstract</p> <p>Background</p> <p><it>Saccharomyces cerevisiae </it>is the first eukaryotic organism for which a multi-compartment genome-scale metabolic model was constructed. Since then a sequence of improved metabolic reconstructions for yeast has been introduced. These metabolic models have been extensively used to elucidate the organizational principles of yeast metabolism and drive yeast strain engineering strategies for targeted overproductions. They have also served as a starting point and a benchmark for the reconstruction of genome-scale metabolic models for other eukaryotic organisms. In spite of the successive improvements in the details of the described metabolic processes, even the recent yeast model (i.e., <it>i</it>MM904) remains significantly less predictive than the latest <it>E. coli </it>model (i.e., <it>i</it>AF1260). This is manifested by its significantly lower specificity in predicting the outcome of grow/no grow experiments in comparison to the <it>E. coli </it>model.</p> <p>Results</p> <p>In this paper we make use of the automated GrowMatch procedure for restoring consistency with single gene deletion experiments in yeast and extend the procedure to make use of synthetic lethality data using the genome-scale model <it>i</it>MM904 as a basis. We identified and vetted using literature sources 120 distinct model modifications including various regulatory constraints for minimal and YP media. The incorporation of the suggested modifications led to a substantial increase in the fraction of correctly predicted lethal knockouts (i.e., specificity) from 38.84% (87 out of 224) to 53.57% (120 out of 224) for the minimal medium and from 24.73% (45 out of 182) to 40.11% (73 out of 182) for the YP medium. Synthetic lethality predictions improved from 12.03% (16 out of 133) to 23.31% (31 out of 133) for the minimal medium and from 6.96% (8 out of 115) to 13.04% (15 out of 115) for the YP medium.</p> <p>Conclusions</p> <p>Overall, this study provides a roadmap for the computationally driven correction of multi-compartment genome-scale metabolic models and demonstrates the value of synthetic lethals as curation agents.</p
Expanding Functionality of Recombinant Human Collagen Through Engineered Non-Native Cysteines
Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing.
Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage
Infrared Studies on the Interaction of Carbon Monoxide with Divalent Nickel in Hydrogenase from Chromatium vinosum
The ALICE experiment at the CERN LHC
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008
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