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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Ferromagnetic particles as ultra-sensitive non-linear response labels for magnetic particles imaging (MPI) and sensing applications
A significant enhancement of detection capabilities of the room temperature MPQ is seen using optical lithography-defined, ferromagnetic iron-nickel alloy microdisks. Irreversible transitions between strongly non-collinear (vortex) and a collinear single domain states, driven by an ac magnetic field, translate into a nonlinear magnetic response that enables ultrasensitive detection of material at relatively small magnetic fields.
Data-driven delta-generalized labeled multi-bernoulli tracker
A system and method for tracking a plurality of objects. Unlabeled measurement data identifying a plurality of targets corresponding to the plurality of objects is received. A multi-target likelihood function is generated using a persistent target density, a birth target density, and a clutter density. The multi-target likelihood function is used to associate persistent targets with the unlabeled measurement data to update persistent tracks and to initiate a new track for each target in the plurality of targets in the measurement data that is not associated with a persistent target.
Convolutional neural networks for classification and labeling of defects on atomic scale silicon surfaces.
Abstract not provided.
Parallel Accelerator and Molecular Mass Spectrometry Measurement of Carbon-14 Labeled Analytes
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RE-LABELING DOMAINS IMPROVES MULTI-DOMAIN GENERALIZATION
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Exploring the strength of weak ties to direct active learning for community label prediction.
Abstract not provided.
Multiplex Chemical Labeling of Amino Acids for Protein Footprinting Structure Assessment
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Reagent to label proteins via lysine isopeptide bonds
Covalently cross-linked pilus polymers displayed on the cell surface of Gram-positive bacteria are assembled by class C sortase enzymes. These pilus-specific transpeptidases located on the bacterial membrane catalyze a two-step protein ligation reaction—first, cleaving the LPXTG motif of one pilin protomer to form an acyl-enzyme intermediate, and second, joining the terminal threonine to the nucleophilic lysine residue residing within the pilin motif of another pilin protomer. Informed by the high-resolution crystal structures of corynebacterial pilus-specific sortase (SrtA) and by developing structural variants of the sortase enzyme whose catalytic pocket has been unmasked by activating mutations, we have developed new reagents capable of forming isopeptide bonds in vitro. The reagents disclosed herein can catalyze ligation of isolated SpaA domains in vitro provide a facile and versatile new platform for protein engineering and bio-conjugation that has major implications for biotechnology.
Ferromagnetic particles as ultra-sensitive non-linear response labels for magnetic particles imaging (MPI) and sensing applications
A significant enhancement of detection capabilities of the room temperature MPQ is seen using optical lithography-defined, ferromagnetic iron-nickel alloy microdisks. Irreversible transitions between strongly non-collinear (vortex) and a collinear single domain states, driven by an ac magnetic field, translate into a nonlinear magnetic response that enables ultrasensitive detection of material at relatively small magnetic fields.
Iterative Error-Driven Ensemble Labeling (IEDEL) Algorithm for Enhanced Data Quality Control for the Atmospheric Radiation Measurement (ARM) Program User Facility
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A Semi-Supervised Model for Multi-Label Radioisotope Classification and Out-of-Distribution Detection
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Identifying Objects via Encased X-Ray-Fluorescent Materials - the Bar Code Inside
Systems for identifying objects by means of x-ray fluorescence (XRF) of encased labeling elements have been developed. The XRF spectra of objects so labeled would be analogous to the external bar code labels now used to track objects in everyday commerce. In conjunction with computer-based tracking systems, databases, and labeling conventions, the XRF labels could be used in essentially the same manner as that of bar codes to track inventories and to record and process commercial transactions. In addition, as summarized briefly below, embedded XRF labels could be used to verify the authenticity of products, thereby helping to deter counterfeiting and fraud. A system, as described above, is called an encased core product identification and authentication system (ECPIAS). The ECPIAS concept is a modified version of that of a related recently initiated commercial development of handheld XRF spectral scanners that would identify alloys or detect labeling elements deposited on the surfaces of objects. In contrast, an ECPIAS would utilize labeling elements encased within the objects of interest. The basic ECPIAS concept is best illustrated by means of an example of one of several potential applications: labeling of cultured pearls by labeling the seed particles implanted in oysters to grow the pearls. Each pearl farmer would be assigned a unique mixture of labeling elements that could be distinguished from the corresponding mixtures of other farmers. The mixture would be either incorporated into or applied to the surfaces of the seed prior to implantation in the oyster. If necessary, the labeled seed would be further coated to make it nontoxic to the oyster. After implantation, the growth of layers of mother of pearl on the seed would encase the XRF labels, making these labels integral, permanent parts of the pearls that could not be removed without destroying the pearls themselves. The XRF labels would be read by use of XRF scanners, the spectral data outputs of which would be converted to alphanumeric data in a digital equivalent data system (DEDS), which is the subject of the previous article. These alphanumeric data would be used to track the pearls through all stages of commerce, from the farmer to the retail customer.
Radiotracers For Lipid Signaling Pathways In Biological Systems
The primary focus of this project continues to be the development of radiotracers and radiotracer methodology for studying physiology and biochemistry. The compounds that have been labeled areacylethanolamines and acylglycerols that are, as classes, represented in both in plants and in animals. In the latter, some of these act as ligands for cannabinoid receptors and they are therefore known as endocannabinoids. Cannabinoid receptors are not found in plant genomes so that plants must contain other receptors and signaling systems that use acylethanolamines. Relatively little work has been done on that issue, though acylethanolamines do modulate plant growth and stress resistance, thus possessing obvious relevance to agriculture and energy production. Progress has been described in five peer-reviewed papers and seven meeting abstracts. Preparation of 2-acylglycerol lipid messengers in high purity. A novel enzymatic synthesis was developedthat gave pure 2-acylglycerols free of any rearrrangement to the thermodynamically more stable 1(3)-acylglycerol byproducts. The method utilized 1,3-dibutyryl-2-acylglycerol substrate ethanolysis by a resinimobilized lipase. Thus, pure radiolabeled 2-acylglycerols can now be conveniently prepared just prior to their utilization. These synthetic studies were published in the Journal of Medicinal Chemistry, 2011. Diacylglycerol lipase assay methodology. Diacylglycerol lipases (DAGLs) generate 2- acylglycerols, and are thus potential targets for disease- or growth-modifying agents, by means of reducing formation of 2-acylglycerols. A radioTLC assay of the hydrolysis of radiolabeled diglyceride substrate [1''-carbon-14]2-arachidonoyl-1-stearoyl-sn-glycerol has been implemented, and used to validate a novel, potentially highthroughput fluorescence resonance energy transfer (FRET) based assay. A number of new DAGL inhibitors that have selectivity for DAGLs were synthesized and screened. This work was very recently published in Bioorganic and Medicinal Chemistry Letters.Acylethanolamines. The work initially focused on myristoylethanolamine (MEA) labeled in the acyl moiety with tritium and with carbon-14. Standard coupling conditions were used and gave the desired radiotracers in decent yields. Tritiated product was needed for the search for binding sites of this signaling messenger, and C-14 labeled product for imaging using phosphorimaging screens. Additionally, C-14 MEA was prepared labeled in the ethanolamine moiety. Fluorine-18 labeled acylethanolamines. A multi-step synthesis was performed to obtain unlabeled N-(16- fluorohexadecanoyl)ethanolamide for an HPLC standard via the precursor 16-bromo-N- [2[(tetrahydro-2Hpyran-2-yl)oxy]ethyl]hexadecanoylamide. Near-anhydrous F-18 and the bromo precursor (approximately 2-3 mg) in acetonitrile (0.5 ml) were heated with a PETWave microwave reactor for 10 min at 80 °C. F-18 incorporation was checked using silica-gel TLC (8:92 methanol/chloroform). Deprotection was carried out using TFA. The crude product was purified by semi-preparative ODS HPLC (80:20 AcN/ H2O). The product peak was diluted in water, concentrated on an SPE column, and eluted in 1 mL EtOH. F-18 incorporation to form the THP protected product was >90% with negligible side products observed. Deprotection and HPLC purification proceeded successfully with >99% radiochemical l purity. Brain distribution studies were done in mice. This work was presented at the Society of Nuclear Medicine meeting in June 2012. Subsequent more detailed studies including whole body tissue distribution studies, microPET experiments and radiochromatographic studies were published in ACS Chemical Neurosciences in 2014. Iodine-125 labeled acylethanolamines. The precursor 12-bromo-N-[2[(tetrahydro-2H-pyran-2-yl)oxy]ethyl]dodecanoylamide was prepared and a 1 mg sample was subject to exchange labeling withradioiodide in refluxing acetonitrile for 1 hour. HPLC analysis as above indicated incorporation of about10% of the radioactivity into a compound with the expected retention time of the corresponding iodocompound. Treatment with TFA converted the radioactivity into a compound with the expected retentiontime of 12-iodododenanoyl ethanolamine. Radiotracer studies in plants. One of the aims of this funding was to follow up the studies of Tripathy et al. (Plant Physiol., 2003) who first reported high affinity binding sites for tritiated myristoylethanolamine in plants, and also reported blockage of these sites by the cannabinoid receptor antagonist AM281. Because plant genomes do not contain genes for cannabinoid receptors, this was an intriguing report. I-125 labeled AM281 was therefore prepared, to facilitate identification of binding sites for this compound in Arabodopsis thaliana plants. However, such sites could not be found, the binding studies were repeated in tobacco plants. Again, binding sites for AM281 were not found. Additionally, it has become evident that clear demonstration of binding sites for tritiated MEA is obscured by metabolic incorporation of radioactivity into plant tissues. Studies on this issue are being aggressively pursued. Binding methodologies used in experiments with animal tissues require modification for their optimal use with plant tissues. Detailed studies of [14C]myristoylethanolamine isotopomers and of [14C]arachidonoylethanolamine isotopomers Since the labeled compounds being prepared for experiments with plants may have utility in Nuclear Medicine, studies were conducted with some of these compounds in mice. The brain uptake of C-14 MEA labeled in either acyl or ethanolamine moiety was 3-4 fold higher than uptake of C-14 myristic acid or C-14 ethanolamine. Carrier MEA increased brain uptake. Autoradiographs of MEA showed regionally specific uptake, with somewhat different patterns for acyl and ethanolamine isotopomers. It is hypothesized that these labeled compounds might form the basis of autoradiographic imaging of regional activity of enzymes such as fatty acid amide hydrolase, which may regulate endocannabinoid tone in animals. Early results were presented at the 2011 ICRS meeting, and at the 2012 Society for Neurosciences. Narachidonoylethanolamine is an endocannabinoid signaling messenger in animals and is known as “anandamide”. It is one of several families of signaling molecules derived from arachidonic acid, the principal omega-6 polyunsaturated fatty acids (PUFA’s) in animal species. Other derivatives of arachidonic acid include thromboxanes and prostaglandins. Full details of the studies with the ethanolamide isotopomers were a part of the PhD dissertation of Kun Hu (nee Qian), and were submitted for publication to Nuclear Medicine and Biology in August 2016. Syntheses of [14C]docosahexanoylethanolamine isotopomers and preliminary biological investigations Docosahexaenoic acid (DHA) is the omega-3 PUFA that can be regarded in some respects as the counterpart of arachidonic acid in the omega-6 series. While arachidonic acid is proinflammatory, DHA is anti-inflammatory, and foods high in DHA (or artificially enriched in DHA) are commonly regarded as promoting health. In contrast to the large literature on the Nethanolamide of arachidonic acid (i.e. the endocannabinoid anandamide) as of now (9/25/2016) there are only six papers on the corresponding ethanolamide of DHA, and when our studies under this grant began there were none. Beneficial actions of endogenously produced DHAethanolamine (“synaptamide”) have been indicated, and to help elucidate the possible roles of synaptamide, we have synthesized this molecule for the first time labeled with C-14 in either the ethanolamine moiety or the fatty acid moiety. Studies of the disposition of endogenously administered isotopomers of DHA-ethanolamine are in progress, to complement tissue culture experiments evaluation hypothesized protective effects of this DHA derivative.
Evaluation of new approaches to the access of official monitoring results for live bivalves molluscs
Abstract Background Live bivalve molluscs, echinoderms, tunicates and marine gastropod are referred in EU food laws, and require member states to implement official controls in classified production areas, with the monitoring and classification of those areas. If, due to contaminant tests results, a production area is closed, any product from there is prohibited to be commercialized. Mobile applications optical character recognition (OCR) functionalities could ease the access to contaminant levels and production area classifications. This study verifies what information is available in live bivalves’ labels, describes an OCR algorithm for those labels and evaluates it. Methods 86 labels were selected from four sale points in Lisbon, and photographed using smartphones. Each label was evaluated by a human to determine what data was available (either required or not). An OCR algorithm was developed and applied on the collected labels and validated against the data extracted by the human analysis. Results The analysis shows that all the labels included the required information, and 63% of the labels included the identifier for the production zone. The label-reading algorithm performs with an accuracy of 79.85% for the individual values. Conclusion High accuracy of the developed label-reading algorithm shows potential for providing instant automatic access to the date and production area, but is affected by the variability on the label structure. Although not required by food laws, the majority of the sampled labels included complementary information (classified production area) that will allow access to more precise information about the existing biotoxin tests and analysis results.
ACCELERATED FITTING OF STELLAR SPECTRA
Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.
Ask-The-Expert: Minimizing Human Review for Big Data Analytics Through Active Learning
In this CIF project, we worked toward semi-automating knowledge discovery from anomaly detection algorithms through the use of active learning. Active learning is an area of research within machine learning that uses an "expert in the loop" to learn from large data sets that have very few annotations or labels available, and where providing such labels is expensive. In our case, the task can be defined as the identification of safety events from flight operational data. Since traditional anomaly detection algorithms cannot differentiate between operationally relevant and irrelevant statistical anomalies, Subject Matter Experts (SMEs) have a lengthy and expensive burden of investigating every example identified by the detection algorithm, classifying and labeling them as relevant or irrelevant. Active learningidentifies the unlabeled example for which a label would most improve the classifier, asks the domain expert for a label, and repeats this process until there are no more resources (time, budget) available for labeling or a minimum required performance is reached. A positive label indicates an operationally significant safety event whereas a negative label indicates otherwise. Based on these few labels we propose to build an active learning system that utilizes the SME's time in the most effective manner by iteratively asking for labels for as few informative instances as possible. Our work was proposed to be a stepping stone toward implementation and deployment of the system with user interface to be pursued by the Aviation Operations and Safety Program (AOSP) given its interest in safety monitoring and discovery of safety incidents.