Articulated elastic-loop roving vehicles

Prototype vehicle features exceptional obstacle-negotiating and slope-climbing capabilities plus high propulsive efficiency. Concept should interest designers of polar or ocean-bottom research vehicles. Also, its large footprint and low ground pressure will minimize ecological damage on terrain with low bearing strength, as in off-the-road application

Optimum rendezvous guidance study Interim report

Minimum fuel rendezvous guidance of powered interceptor from parking orbit to target in coplanar circular orbi

Extending the Strategy Based Risk Model Using the Delphi Method: An Application to the Validation Process for Research and Developmental (R&D) Satellites

The validation between a research and developmental satellite and its ground system is critical to ensuring the success on-orbit. However, the exact process for completing validation is not documented, frequently underfunded, and accomplished ad hoc. This leads to debate regarding maintenance of budget and schedule, while ensuring on-orbit success. This thesis examines readiness and on-orbit activities within the U.S. Air Force Space Development and Test Wing\u27s Research Development Test and Evaluation Support Complex. Combining historical data with the consultation of subject matter experts, a validation process was defined. Risks associated with this process were then analyzed using the Strategy Based Risk Model, and were evaluated based on the probability of occurrence and severity of impact. The validation process and associated costs were validated using the Delphi Method. Next, we transformed the results into a simulation that generates distributions of possible costs and risk outcomes. Finally we applied the simulation to a program, and distributed it to program managers for feedback. The simulation will be distributed to program offices to support tailoring a validation plan relative to their budget. The simulation will give decision makers greater fidelity into the expected risks and costs associated with the selected validation process

Operational loopwheel suspension systems for Mars Rover demonstration model: Loopwheel failure report

The results are presented from the analysis of a failure which occurred in the fiberglass loop of one of the Loopwheel traction elements delivered to the Jet Propulsion Laboratory (JPL) for use on the JPL Mars Rover demonstration model. The loop failed in compression in the outer fibers forming a hinge which, through cycling, caused the inner fibers to break. The probable cause of this failure was the load being introduced as point loads at the center of the loop causing high compressive stresses and early buckling. To decrease the stress level and delay buckling, the tread lugs can be reshaped so that the entire lug contacts the ground when the loop is loaded. This can be accomplished through removal of lug material, starting with zero removal at the outer edge and linearly increasing to one-half of the lug thickness at the center

Pressure-induced changes of the vibrational modes of spin-crossover complexes studied by nuclear resonance scattering of synchrotron radiation

Nuclear inelastic scattering (NIS) spectra were recorded for the spin-crossover complexes STP and ETP (STP = [Fe(1,1,1-trisf[N-(2-pyridylmethyl)-N-methylamino]methylg- ethane)](ClO4)2 and ETP = [Fe(1,1,1-trisf[N-(2-pyridylmethyl)-N-methylamino]methylg-butane)](ClO4)2) at 30 K and at room temperature and also at ambient pressure and applied pressure (up to 2.6 GPa). Spin transition from the high-spin (HS) to the low-spin (LS) state was observed by lowering temperature and also by applying pressure at room temperature and has been assigned to the hardening of iron-bond stretching modes due to the smaller volume in the LS isomer

Gemcitabine alters the proteasome composition and immunopeptidome of tumour cells

The antigenic makeup of tumour cells can have a profound effect on the progression of cancer and success of immunotherapies. Therefore, one strategy to improve the efficacy of cancer treatments is to augment the antigens displayed by tumours. The present study explores how the recognition of tumour cells may be altered by non-cytotoxic concentrations of gemcitabine (GEM). Testing a panel of chemotherapeutics in human cancer cell lines in vitro, it was found that GEM increased surface expression of HLA-A,B,C and that underlying this were specific increases in β-2-microglobulin and immunoproteasome subunit proteins. Furthermore, the peptide antigen repertoire displayed on HLA class I was altered, revealing a number of novel antigens, many of which that were derived from proteins involved in the DNA-damage response. Changes in the nature of the peptide antigens eluted from HLA-A,B,C after GEM treatment consisted of amino acid anchor-residue modifications and changes in peptide length which rendered peptides likely to favour alternative HLA-alleles and increased their predicted immunogenicity. Signalling through the MAPK/ERK and NFκB/RelB pathways was associated with these changes. These data may explain observations made in previous in vivo studies, advise as to which antigens should be used in future vaccination protocols and reinforce the idea that chemotherapy and immunotherapy could be used in combination

Density functional theory calculations and vibrational spectroscopy on iron spin-crossover compounds

Iron complexes with a suitable ligand field undergo spin-crossover (SCO), which can be induced reversibly by temperature, pressure or even light. Therefore, these compounds are highly interesting candidates for optical information storage, for display devices and pressure sensors. The SCO phenomenon can be conveniently studied by spectroscopic techniques like Raman and infrared spectroscopy as well as nuclear inelastic scattering, a technique which makes use of the M\"ossbauer effect. This review covers new developments which have evolved during the last years like, e.g. picosecond infrared spectroscopy and thin film studies but also gives an overviewon newtechniques for the theoretical calculation of spin transition phenomena and vibrational spectroscopic data of SCO complexes

Associations of social processing abilities with psychosocial stress sensitivity

Through the long-term activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, chronic psychosocial stress can compromise mental and bodily health. Psychosocial stress is determined by the perception of social interactions as ego-threatening, and thus strongly influenced by individual social processing capacities. In the current study, we investigated whether three key components of social processing are linked to how individuals respond to the experience of acute psychosocial stress exposure. Empathy, compassion, and Theory of Mind (ToM) were assessed using a state-of-the-art paradigm, the EmpaToM. Participants (N = 118) also underwent the Trier Social Stress Test (TSST), a standardized psychosocial laboratory stress test. Stress responses were measured in terms of salivary cortisol and alpha-amylase, heart-rate, high-frequency heart-rate variability (HF-HRV), and subjective stress experience. ToM performance correlated with different aspects of the acute psychosocial stress response. More specifically, higher levels of ToM were linked to increased alpha-amylase and reduced HF-HRV sensitivity to stress. Empathy and compassion levels had no influence on stress sensitivity. We conclude that ToM performance has a stable albeit contradictory association with acute psychosocial stress, while empathy and compassion tendencies appear to be largely unrelated. Overall, the relationship between EmpaToM-derived empathy, compassion, and ToM characteristics with stress sensitivity in the TSST is relatively weak