2,873 research outputs found
Extended learning program evaluation
The rationale for the development of this project is to improve the quality of education for the gifted education program at the Marion Independent School District. The project was based upon the evaluation instruments employed to parents, students, and teachers effected by the ELP in the grades kindergarten through third grade. Parents were given a survey regarding the ELP program goals and objectives, communication, and satisfaction of the program. Students were given surveys regarding their learning and feelings about the program. Teachers were given surveys discussing a variety of topics dealing with parents, students, and services provided in the program
Methodology for the Integration of Optomechanical System Software Models with a Radiative Transfer Image Simulation Model
Stray light, any unwanted radiation that reaches the focal plane of an optical system, reduces image contrast, creates false signals or obscures faint ones, and ultimately degrades radiometric accuracy. These detrimental effects can have a profound impact on the usability of collected Earth-observing remote sensing data, which must be radiometrically calibrated to be useful for scientific applications. Understanding the full impact of stray light on data scientific utility is of particular concern for lower cost, more compact imaging systems, which inherently provide fewer opportunities for stray light control. To address these concerns, this research presents a general methodology for integrating point spread function (PSF) and stray light performance data from optomechanical system models in optical engineering software with a radiative transfer image simulation model. This integration method effectively emulates the PSF and stray light performance of a detailed system model within a high-fidelity scene, thus producing realistic simulated imagery. This novel capability enables system trade studies and sensitivity analyses to be conducted on parameters of interest, particularly those that influence stray light, by analyzing their quantitative impact on user applications when imaging realistic operational scenes. For Earth science applications, this method is useful in assessing the impact of stray light performance on retrieving surface temperature, ocean color products such as chlorophyll concentration or dissolved organic matter, etc. The knowledge gained from this model integration also provides insight into how specific stray light requirements translate to user application impact, which can be leveraged in writing more informed stray light requirements.
In addition to detailing the methodology\u27s radiometric framework, we describe the collection of necessary raytrace data from an optomechanical system model (in this case, using FRED Optical Engineering Software), and present PSF and stray light component validation tests through imaging Digital Imaging and Remote Sensing Image Generation (DIRSIG) model test scenes. We then demonstrate the integration method\u27s ability to produce quantitative metrics to assess the impact of stray light-focused system trade studies on user applications using a Cassegrain telescope model and a stray light-stressing coastal scene under various system and scene conditions. This case study showcases the stray light images and other detailed performance data produced by the integration method that take into account both a system\u27s stray light susceptibility and a scene\u27s at-aperture radiance profile to determine the stray light contribution of specific system components or stray light paths. The innovative contributions provided by this work represent substantial improvements over current stray light modeling and simulation techniques, where the scene image formation is decoupled from the physical system stray light modeling, and can aid in the design of future Earth-observing imaging systems. This work ultimately establishes an integrated-systems approach that combines the effects of scene content and the optomechanical components, resulting in a more realistic and higher fidelity system performance prediction
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Tryptophan metabolism and its relationship with immune activation, depression, and neurocognitive impairment among HIV-infected individuals
Constellation Program Electrical Ground Support Equipment Research and Development
At the Kennedy Space Center, I engaged in the research and development of electrical ground support equipment for NASA's Constellation Program. Timing characteristics playa crucial role in ground support communications. Latency and jitter are two problems that must be understood so that communications are timely and consistent within the Kennedy Ground Control System (KGCS). I conducted latency and jitter tests using Alien-Bradley programmable logic controllers (PLCs) so that these two intrinsic network properties can be reduced. Time stamping and clock synchronization also play significant roles in launch processing and operations. Using RSLogix 5000 project files and Wireshark network protocol analyzing software, I verified master/slave PLC Ethernet module clock synchronization, master/slave IEEE 1588 communications, and time stamping capabilities. All of the timing and synchronization test results are useful in assessing the current KGCS operational level and determining improvements for the future
Analysis of pathogenic pseudoexons reveals novel mechanisms driving cryptic splicing
Understanding pre-mRNA splicing is crucial to accurately diagnosing and treating genetic diseases. However, mutations that alter splicing can exert highly diverse effects. Of all the known types of splicing mutations, perhaps the rarest and most difficult to predict are those that activate pseudoexons, sometimes also called cryptic exons. Unlike other splicing mutations that either destroy or redirect existing splice events, pseudoexon mutations appear to create entirely new exons within introns. Since exon definition in vertebrates requires coordinated arrangements of numerous RNA motifs, one might expect that pseudoexons would only arise when rearrangements of intronic DNA create novel exons by chance. Surprisingly, although such mutations do occur, a far more common cause of pseudoexons is deep-intronic single nucleotide variants, raising the question of why these latent exon-like tracts near the mutation sites have not already been purged from the genome by the evolutionary advantage of more efficient splicing. Possible answers may lie in deep intronic splicing processes such as recursive splicing or poison exon splicing. Because these processes utilize intronic motifs that benignly engage with the spliceosome, the regions involved may be more susceptible to exonization than other intronic regions would be. We speculated that a comprehensive study of reported pseudoexons might detect alignments with known deep intronic splice sites and could also permit the characterisation of novel pseudoexon categories. In this report, we present and analyse a catalogue of over 400 published pseudoexon splice events. In addition to confirming prior observations of the most common pseudoexon mutation types, the size of this catalogue also enabled us to suggest new categories for some of the rarer types of pseudoexon mutation. By comparing our catalogue against published datasets of non-canonical splice events, we also found that 15.7% of pseudoexons exhibit some splicing activity at one or both of their splice sites in non-mutant cells. Importantly, this included seven examples of experimentally confirmed recursive splice sites, confirming for the first time a long-suspected link between these two splicing phenomena. These findings have the potential to improve the fidelity of genetic diagnostics and reveal new targets for splice-modulating therapies
Introduction to the political economy of the sub-prime crisis in Britain : constructing and contesting competence
It is almost always inadvisable to try to second-guess the character of a General Election campaign before it begins in earnest. Yet, even in today’s shadow-boxing phase in advance of the British General Election due to be called in 2010, a number of important campaign contours are already in evidence. It is one of the unwritten laws of British electoral politics that governments unravel – particularly those of a certain longevity – as events appear ever more to have spiralled out of their control. The task for the Brown Government in the upcoming General Election campaign is to try to convince voters that there is still life left within Labour despite its current travails with the credit crunch and British banks’ self-imposed entrapment in the subprime crisis. Claim and counter-claim are likely to pass between the Government and the opposition parties as to where the blame lies for the current disarray of the banking sector, whose model of regulation is most responsible and who is best placed to ensure a successful clean-up operation. Whoever is perceived to have come out on top in this debate is likely to stand a very good chance of winning the election
A novel reductive transformation of oxazepam to nordiazepam observed during enzymatic hydrolysis
β-Glucuronidase is an enzyme often employed to de-conjugate β-glucuronides during urinary drug testing for benzodiazepines. It is commonly accepted that use of β-glucuronidase is a preferred method of hydrolysis over acid-catalyzed hydrolysis, which is known to induce benzodiazepine degradation and transformation. Literature to date, however, has not reported any cases of benzodiazepine transformation initiated by commercial β-glucuronidase products. In this study, urine specimens containing either oxazepam or oxazepam glucuronide were incubated with β-glucuronidase enzymes obtained from Escherichia coli, Helix pomatia, and Patella vulgata under various incubation conditions. After liquid-liquid extraction, the extract was analyzed by both liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry for the presence of benzodiazepines. All three enzyme preparations examined were capable of reducing oxazepam or oxazepam glucuronide into nordiazepam (desmethyldiazepam). Nordiazepam formation was positively correlated with incubation temperature, incubation time, oxazepam concentration, and enzyme concentration. Under all enzymatic hydrolysis conditions investigated, the percentage of nordiazepam formation is < 2.5% relative to the amount of oxazepam present in the system. The findings of this study have both clinical and forensic implications, and it is clear that the detection of nordiazepam in biological samples subjected to testing involving enzyme-catalyzed hydrolysis should be interpreted with care
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