Sensitivity analysis of a relative navigation solution for unmanned aerial vehicles in a GNSS-denied environment

Cooperative navigation between two or more unmanned aerial vehicles (UAVs) is an important enabling technology for problems such as military reconnaissance, disaster response, and search and rescue. In many of these situations Global Navigation Satellite Systems (GNSS), such as Global Positioning System (GPS), may be unreliable or unavailable due to structural impedance or malicious signal jamming. Therefore, the task of maintaining a reliable relative navigation solution without the use of GNSS is an important need for the aforementioned missions.;To meet this need, this thesis focuses on the relative navigation between two UAVs that are operating in a GNSS-denied environment. In particular, the design and sensitivity of a navigation algorithm are presented. The navigation algorithm presented consists of an Unscented Kalman filter that fuses multiple on-board sensors to estimate the relative pose between two UAVs. These sensors include: strap-down inertial measurement units, ultra-wideband ranging radios, strap-down tri-axial magnetometers, and downward facing cameras. Through the use of a Monte Carlo simulation study, the presented algorithm\u27s performance sensitivity to various sensor payload characteristics, flight dynamics, and initial condition errors is evaluated. Additionally, a research platform that will provide for a future experimental evaluation of the algorithm presented in this thesis has been integrated and tested as part of this work

The Impact of Relapses on Pain and Quality of Life in Patients with Multiple Sclerosis Treated with Corticosteroids

Background: We assessed the prevalence and risks associated with pain during and after a multiple sclerosis (MS) relapse, and the impact of pain on quality of life (QoL), in MS patients. // Methods: 117 patients suffering an acute MS relapse were evaluated with clinician- and patient-reported outcomes, including the expanded disability status scale (EDSS), Multiple Sclerosis Impact Scale (MSIS-29), and MS Walking scale-12 (MSWS-12). Relapse-related pain was assessed via the short-form 36 (SF-36) questionnaire upon first visit (relapse onset) and at 6 weeks after treatment with intravenous methylprednisolone (follow-up visit). // Results: Pain was present in 80% of patients at relapse onset. Patients with pain were more impaired physically (higher mean scores on MSIS-29phys and MSWS-12 and lower mean scores on SF-36 role physical, physical, and vitality scales) at relapse and six weeks after. In total, 74% of patients with MS relapse reported a poorer QoL due to pain. A lower psychological well-being was correlated with greater pain (MSIS29psy score). An increased number of prior relapses was a predictor of more pain at relapse onset. // Conclusions: Pain was common at the time of MS relapse and improved, but was still significant, six weeks after treatment with corticosteroids. Further studies are required to better understand relapse-related pain

Editorial:LRRK2-Fifteen Years From Cloning to the Clinic

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Sensitivity Analysis of Detect and Avoid Well Clear Parameter Variations on UAS DAA Sensor Requirements

In support of NASAs Unmanned Aircraft Systems Integration in the National Airspace System project and RTCA Special Committee 228, an analysis has been performed to provide insight in to the trade space between detect and avoid (DAA) Well Clear definition threshold variations, which could affect DAA sensor range and alerting requirements

Analysis of Influence of UAS Speed Range and Turn Performance on Detect and Avoid Sensor Requirements

In support of NASAs Unmanned Aircraft Systems Integration in the National Airspace System project and RTCA Special Committee 228, an analysis has been performed to provide insight in to the trade space between unmanned aircraft speed and turn capability and detect and avoid sensor range requirements. The work was done as an initial part of the effort to understand low size, weight, and power sensor requirements for aircraft that have a limited speed envelope or can limit the envelope for portions of their mission and may be able to turn at higher than standard rate. Range and timeline reductions coming from limiting speed range and from increasing available turn rate in some speed ranges are shown

Principal Leadership in a Virtual Environment

Commissioned by The Wallace Foundation, which supports efforts to promote effective school leadership, this report sets out to define what high-quality, equitable learning looks like in a virtual environment. It poses questions for school district leaders to ask if they want to develop principals who can lead their schools to this type of learning. It also describes strategies for districts to consider in efforts to develop a whole pipeline of principals adept at high-quality, equitable virtual learning—using a definition of an "aligned, comprehensive principal pipeline" that emerged through research and field work funded by The Wallace Foundation. The report is based on an examination of research literature supplemented by interviews with 11 principals and administrators knowledgeable about virtual learning. It also draws on Digital Promise's experience in working with schools and school districts. The final chapter looks at topics that merit further exploration in the areas of virtual learning, equity, and school leadership

Profiles of SUMO and ubiquitin conjugation in an Alzheimer's disease model

► Global levels of ubiquitinated proteins increased in the hippocampus of Tg2576 mice. ► No global changes in either SUMO-1 or SUMO-2/3 conjugation in any brain regions analysed. ► SUMO conjugating and deconjugating enzymes, UBC9 and SENP-1, unaltered in Tg2576 mice. ► Total levels of AMPA and kainate receptors were also unaffected in Tg2576 mice. ► Posttranslational modification by ubiquitin may play a role in Alzheimer's disease

What drives amyloid molecules to assemble into oligomers and fibrils?

We develop a general theory for three states of equilibrium of amyloid peptides: the monomer, oligomer, and fibril. We assume that the oligomeric state is a disordered micelle-like collection of a few peptide chains held together loosely by hydrophobic interactions into a spherical hydrophobic core. We assume that fibrillar amyloid chains are aligned and further stabilized by `steric zipper' interactions -- hydrogen bonding and steric packing, in addition to specific hydrophobic sidechain contacts. The model makes a broad set of predictions, consistent with experiments: (i) Similar to surfactant micellization, amyloid oligomerization should increase with bulk peptide concentration. (ii) The onset of fibrillization limits the concentration of oligomers in the solution. (iii) The average fibril length \emph{vs.} monomer concentration agrees with data on $\alpha$-synuclein, (iv) Full fibril length distributions follow those of $\alpha$-synuclein, (v) Denaturants should `melt out' fibrils, and (vi) Added salt should stabilize fibrils by reducing repulsions between amyloid peptide chains. Interestingly, small changes in solvent conditions can: (a) tip the equilibrium balance between oligomer and fibril, and (b) cause large changes in rates, through effects on the transition-state barrier. This model may provide useful insights into the physical processes underlying amyloid diseases