The Fine Guidance Sensor, An Electronic Scanning Star Tracker

The advent of space exploration has placed hitherto unheard of requirements on accuracy and precision sensing devices for guidance and attitude control. The necessity for high reliability, due to non-repairability, required new approaches to this design problem. Rather than try to improve upon existing systems, components, and approaches, a totally new concept evolved which eliminates the mechanical rotors and reticles of yesterday. Instead, a totally new breed of electronic scanning star sensor resulted. This paper describes one such device, a Boresighted Star and Planet Tracker developed for precise attitude sensing and control of an experimental sounding rocket. Discussed are the major elements of the basic sensing system, optics, detector, and electronics. The heart of the new sensor is the electronic scanning multiplier phototube, a small, rugged, highly accurate and highly reliable device. Electronic circuit design to enhance accuracy and precision is outlined

What does it mean to be “prepared for work”? Perceptions of new engineers

Background: Engineering education seeks to prepare students for engineering practice, but the concept of preparedness is often ill-defined. Moreover, findings from studies of different populations or in different contexts vary regarding how well new graduates are prepared. These variations, coupled with the lack of clarity, suggest the need to better understand what it means to be prepared for engineering work. Purpose: This study contributes to research on workplace preparation by exploring how new graduates describe being prepared for engineering work. Method: Applying secondary analysis to data from the multi-institution Capstone To Work (C2W) project, we used thematic analysis to explore new engineers\u27 descriptions of preparedness. We analyzed written responses to structured questions about the school-to-work transition collected weekly during participants\u27 first 12 weeks of work; 105 graduates drawn from four universities provided 956 responses, with a mean of 9 (out of 12 possible) responses per participant. Results: Participants\u27 descriptions of preparedness included applying concrete skills, recognizing familiar situations, and having strategies for approaching challenging tasks even when they lacked relevant knowledge or skill. Conclusion: Our findings suggest that although many discussions about workplace preparation implicitly focus narrowly on mastery of skills and knowledge, that focus may not fully capture new graduates\u27 experiences, and may limit discussions about the ways in which school can (and cannot) prepare students for work. A more expansive understanding may better support both student learning and workplace onboarding, though more research is needed across stakeholders to establish shared understanding

Aerodynamic and Aeroacoustic Performance of Small UAV Propellers in Static Conditions

The proliferation of small multi-rotor UAVs in commercial, recreational, and surveillance spheres has garnered significant interest in the noise produced by these vehicles. The current research aims to study the relationship between the aerodynamic performance and acoustic characteristics of small-scale UAV propellers. Three commercially available propellers for the DJI Phantom 2/3 UAV were selected for preliminary development and validation of an aeroacoustic experimental test setup and associated data reduction methods. Propeller thrust, torque, and power measurements were recorded at static conditions. Upon successful validation of the test bench, acoustic measurements were taken at the propeller disk’s upstream and in-plane locations. The power spectral density of these acoustic signals was estimated using the modified periodogram (Welch’s) method to identify frequency content and calculate sound pressure levels (SPLs) at each of the observation locations. Additionally, time-frequency analysis verified the periodogram results and identified possible sources of transient noise at static thrust. These methods found the nonrotor noise to be a major contributor to the SPL at higher frequencies and the propeller noise dominating the SPL spectra at the lower frequencies. Experimental thrust, torque, power, and sound pressure level (SPL) data were then compared for each propeller to identify relationships between aerodynamic performance and acoustic characteristics with variations in propeller geometry and blade loading

Sneak preview of the Saskatchewan soil information system (SKSIS)

Non-Peer Reviewe

Saskatchewan Soil Information System (SKSIS)-The Launch!

Non-Peer Reviewe

[(11)C]PiB PET in Gerstmann-Sträussler-Scheinker disease

Gerstmann-Sträussler-Scheinker Disease (GSS) is a familial neurodegenerative disorder characterized clinically by ataxia, parkinsonism, and dementia, and neuropathologically by deposition of diffuse and amyloid plaques composed of prion protein (PrP). The purpose of this study was to evaluate if [(11)C]Pittsburgh Compound B (PiB) positron emission tomography (PET) is capable of detecting PrP-amyloid in PRNP gene carriers. Six individuals at risk for GSS and eight controls underwent [(11)C]PiB PET scans using standard methods. Approximately one year after the initial scan, each of the three asymptomatic carriers (two with PRNP P102L mutation, one with PRNP F198S mutation) underwent a second [(11)C]PiB PET scan. Three P102L carriers, one F198S carrier, and one non-carrier of the F198S mutation were cognitively normal, while one F198S carrier was cognitively impaired during the course of this study. No [(11)C]PiB uptake was observed in any subject at baseline or at follow-up. Neuropathologic study of the symptomatic individual revealed PrP-immunopositive plaques and tau-immunopositive neurofibrillary tangles in cerebral cortex, subcortical nuclei, and brainstem. PrP deposits were also numerous in the cerebellar cortex. This is the first study to investigate the ability of [(11)C]PiB PET to bind to PrP-amyloid in GSS F198S subjects. This finding suggests that [(11)C]PiB PET is not suitable for in vivo assessment of PrP-amyloid plaques in patients with GSS

Cerebral hypometabolism and grey matter density in MAPT intron 10 +3 mutation carriers

Multiple systems tauopathy with presenile dementia (MSTD), a form of frontotemporal dementia with parkinsonism-17 with tau inclusions (FTDP-17T), is a neurodegenerative disorder caused by an (a) to (g) transition at position +3 of intron 10 of the microtubule associated protein tau (MAPT) gene. The mutation causes overexpression of 4 repeat (4R) tau isoforms with increased 4R/3R ratio leading to neurodegeneration. Clinically, these patients primarily present with behavioral variant FTD (bvFTD) and show disinhibition, disordered social comportment, and impaired executive function, memory, and speech. While altered glucose metabolism has been reported in subjects with sporadic bvFTD, it has yet to be investigated in an FTDP-17 sample of this size. In this study, eleven mutation carriers (5 males; mean age = 48.0 ± 6.9 years) and eight non-carriers (2 males; mean age = 43.7 ± 12.0 years) from a MSTD family were imaged using [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Eight of the MAPT intron 10 +3 mutation carriers met diagnostic criteria for bvFTD at the time of the PET scan, while three MAPT intron 10 +3 carriers were not cognitively impaired at the time of scan. Non-carriers had no clinically-relevant cognitive impairment at the time of the PET scan. Additionally, ten mutation carriers (5 males; mean age = 48.04 ± 2.1 years) and seven non-carriers (2 males; mean age 46.1 ± 4.1 years) underwent magnetic resonance imaging (MRI) which is an expanded sample size from a previous study. Seven MAPT mutation carriers met diagnostic criteria for bvFTD at the time of the MRI scan. Images were assessed on a voxel-wise basis for the effect of mutation carrier status. SPM8 was used for preprocessing and statistical analyses. Compared to non-carriers, MAPT mutation carriers showed lower [(18)F]FDG uptake bilaterally in the medial temporal lobe, and the parietal and frontal cortices. Anatomical changes were predominantly seen bilaterally in the medial temporal lobe areas which substantially overlapped with the hypometabolism findings. These anatomical and metabolic changes overlap previously described patterns of neurodegeneration in MSTD patients and are consistent with the characteristics of their cognitive dysfunction. These results suggest that neuroimaging can describe the neuropathology associated with this MAPT mutation

Desenvolvimento de um Sistema de Raciocínio Baseado em Casos na Identificação de Transtornos Mentais

Este artigo descreve o desenvolvimento do Sistema Heuristia. O Heuristia é uma ferramenta disponível via web com o objetivo de auxiliar no diagnóstico de transtornos mentais aplicado na área de psiquiatria, utilizandose para tal da técnica de Raciocínio Baseado em Casos. A técnica de raciocínio baseado em casos propõe a solução de novos problemas adaptando soluções que foram utilizadas em problemas anteriores. A similaridade entre os casos baseia-se na comparação entre casos cadastrados por um especialista da área e um “caso alvo” ou “novo caso”, a ser comparado. Além disso, o sistema conta com o HeuristiaHelp que contém informações sobre definições de termos e procedimentos da psiquiatria

KL∗VS heterozygosity reduces brain amyloid in asymptomatic at-risk APOE∗4 carriers

KLOTHO∗VS heterozygosity (KL∗VSHET+) was recently shown to be associated with reduced risk of Alzheimer's disease (AD) in APOE∗4 carriers. Additional studies suggest that KL∗VSHET+ protects against amyloid burden in cognitively normal older subjects, but sample sizes were too small to draw definitive conclusions. We performed a well-powered meta-analysis across 5 independent studies, comprising 3581 pre-clinical participants ages 60–80, to investigate whether KL∗VSHET+ reduces the risk of having an amyloid-positive positron emission tomography scan. Analyses were stratified by APOE∗4 status. KL∗VSHET+ reduced the risk of amyloid positivity in APOE∗4 carriers (odds ratio = 0.67 [0.52–0.88]; p = 3.5 × 10−3), but not in APOE∗4 non-carriers (odds ratio = 0.94 [0.73–1.21]; p = 0.63). The combination of APOE∗4 and KL∗VS genotypes should help enrich AD clinical trials for pre-symptomatic subjects at increased risk of developing amyloid aggregation and AD. KL-related pathways may help elucidate protective mechanisms against amyloid accumulation and merit exploration for novel AD drug targets. Future investigation of the biological mechanisms by which KL interacts with APOE∗4 and AD are warranted