gebhart/patrepeval huggingface dataset:
Preharvest Aflatoxin Contamination (1993)

Aflatoxins are carcinogens produced by Aspergillus flavus and A. parasiticus when these fungi infect crops before and after harvest, thereby contaminating food and feed and threatening both human and animal health. Traditional control methods (such as the use of certain cultural practices, pesticides and resistant varieties), which effectively reduce populations of many plant pests in the field, have not been effective in controlling aflatoxin-producing fungi. Our research, therefore, consists of acquiring knowledge of: 1) the molecular regulation of aflatoxin formation within the fungus, 2) environmental factors and biocompetitive microbes influencing growth of A. flavus and aflatoxin synthesis in crops, and 3) enhancement of host plant resistance to aflatoxin accumulation through understanding the biochemistry of host plant resistance responses. This understanding is expected to lead to development of biocontrol strategies and/or, in longer term research, development of elite crop lines "immune" to aflatoxin producing fungi.
Automated abdominal plane and circumference estimation in 3D US for fetal screening (2018)

Ultrasound is increasingly becoming a 3D modality. Mechanical and matrix array transducers are able to deliver 3D images with good spatial and temporal resolution. The 3D imaging facilitates the application of automated image analysis to enhance workflows, which has the potential to make ultrasound a less operator dependent modality. However, the analysis of the more complex 3D images and definition of all examination standards on 2D images pose barriers to the use of 3D in daily clinical practice. In this paper, we address a part of the canonical fetal screening program, namely the localization of the abdominal cross-sectional plane with the corresponding measurement of the abdominal circumference in this plane. For this purpose, a fully automated pipeline has been designed starting with a random forest based anatomical landmark detection. A feature trained shape model of the fetal torso including inner organs with the abdominal cross-sectional plane encoded into the model is then transformed into the patient space using the landmark localizations. In a free-form deformation step, the model is individualized to the image, using a torso probability map generated by a convolutional neural network as an additional feature image. After adaptation, the abdominal plane and the abdominal torso contour in that plane are directly obtained. This allows the measurement of the abdominal circumference as well as the rendering of the plane for visual assessment. The method has been trained on 126 and evaluated on 42 abdominal 3D US datasets. An average plane offset error of 5.8 mm and an average relative circumference error of 4.9 % in the evaluation set could be achieved.
Laser gas‐assisted nitriding of steel: residual stress analysis (2010)

Purpose The laser nitriding process is involved with high temperature heating and high cooling rates. This, in turn, results in high levels of thermal stresses in the heated region. Moreover, the residual stress in the heated region remains high after the completion of the heating process, which limits the application of the laser nitriding process. The purpose of this paper is to investigate thermal stresses development and residual stress levels in the nitrided region. Design/methodology/approach The microstructural changes and residual stress development in the laser gas‐assisted nitrided zone are examined. Finite element modeling is carried out to predict temperature and stress fields in the laser nitrided layer. The indentation tests and X‐ray diffraction (XRD) technique are used to determine the residual stress levels while previously derived analytical formula is used to predict the residual stress levels in the nitrided region. Findings The residual stress predicted attains values within 230 MPa, which remains almost uniform in the nitrided layer, except in the surface region. In this case, residual stress reduces slightly due to the low temperature gradient developed in this region and the unconstrained expansion of the free surface. When comparing the residual stress predicted with the measurement results as obtained from the XRD technique as well as the indentation tests, all the results are in reasonably good agreement. The small discrepancies between the experimental data and predictions are attributed to the assumptions made in the model study and the measurement errors. Research limitations/implications The depth of nitrided layer is limited 60 μ m. This limits the applicability of the coating for high wearing rates. Practical implications The nitrided surface improves the surface properties of steel, which can be used in industry more efficiently. Originality/value The paper describes an original model study on stress formation, an experiment for surface characterization and estimation of residual stress formation and contains new findings.
GAD65-Specific Cytotoxic T Lymphocytes Mediate Beta-Cell Death and Loss of Function (2009)

Autoimmunity to islet cell antigens like glutamic acid decarboxylase 65kD (GAD65) is associated with the destruction of insulin-producing beta-cells and progression to type 1 diabetes (T1D) in NOD mice and humans. T cell responses to GAD65 are detectable in the spleen of prediabetic NOD mice and in the peripheral blood of humans prior to the onset of overt hyperglycemia. Previous findings from our lab revealed that GAD65(546-554)-specific cytotoxic T lymphocytes (CTL) are present in naïve NOD mice and are able to induce islet inflammation upon adoptive transfer into NOD.scid recipients. Additionally, we found that professional antigen-presenting cells (APC) generate the p546-554 epitope from a soluble GAD65 fragment, p530-554, and from GAD65 released by injured beta-cells in vivo. Here, we report that the GAD65 fragment p546-554 is a dominant CTL-inducing epitope which is naturally processed and presented by a GAD65-expressing beta-cell line. Further, co-culture of GAD65(546-554)-specific CTL with the beta-cells leads to a reduction in insulin production and the induction of perforin-mediated cell death. Collectively, these findings support a role for the cross-presentation of GAD65 antigen in the priming and enhancement of dominant GAD65-specific CTL responses, which can directly target beta-cells that display GAD65 epitopes.
Sulfur Tolerance of Selective Partial Oxidation of NO to NO2 in a Plasma (1999)

<div class="htmlview paragraph">Several catalytic aftertreatment technologies rely on the conversion of NO to NO<sub>2</sub> to achieve efficient reduction of NO<sub>x</sub> and particulates in diesel exhaust. These technologies include the use of selective catalytic reduction of NO<sub>x</sub> with hydrocarbons, NO<sub>x</sub> adsorption, and continuously regenerated particulate trapping. These technologies require low sulfur fuel because the catalyst component that is active in converting NO to NO<sub>2</sub> is also active in converting SO<sub>2</sub> to SO<sub>3</sub>. The SO<sub>3</sub> leads to increase in particulates and/or poison active sites on the catalyst. A non-thermal plasma can be used for the selective partial oxidation of NO to NO<sub>2</sub> in the gas-phase under diesel engine exhaust conditions. This paper discusses how a non-thermal plasma can efficiently oxidize NO to NO<sub>2</sub> without oxidizing SO<sub>2</sub> to SO<sub>3</sub>.</div>
Synthesis of biodegradable thermoplastic elastomers (BTPE) based on ε-caprolactone (2009)

Aiming to mimic blood vessels, biodegradable thermoplastic elastomer (BTPE) is designed to be elastic, flexible and tough. A series of biodegradable triblock copolymers and poly(ester-urethanes) (PEU) based on -caprolactone have been synthesized and studied. The crystallinity of the poly(-caprolactone) used as soft segment has been disrupted by incorporating either L-lactide (L-LA) units or trimethylene carbonate (TMC) units. Our studies suggest that soft segment composition does affect the mechanical properties significantly.
In Vitro Characterization of a Biologically Active Molecular Clone of HIV-2 <sub>NIH-Z</sub> Containing a <i>nef</i> Deletion and Expressing a Full-Length Transmembrane Protein (1990)

We have previously described the cloning and sequencing of a novel stain of human immunodeficiency virus type 2 (HIV-2) called HIV-2NIH-Z. A plasmid clone, pHIV2Z, containing the full-length provirus has now been constructed, and virus particles have been obtained upon transfection into COS-1 and H-9 cells. These particles can infect a number of T-cell lines and exert a cytopathic effect on fresh human and macaque peripheral blood lymphocytes. The cloned virus is biologically and morphologically indistinguishable from its parental uncloned strain as shown by restriction enzyme analysis, electron microscopy, and kinetics of infection. However, as shown by radioimmunoprecipitation assays, the cloned virus-infected cells express a full-length gp41 protein as predicted by the nucleotide sequence, whereas the wild-type parental strain expresses a truncated gp33 protein. Both the parental strain and the cloned virus possess a deletion encompassing the end of the nef gene within the U3 region which apparently does not affect their in vitro cytopathic and replicative capacities.
Neural Steganalysis with Spatial Rich Models for Image Steganography Detection (2020)

Digital image steganalysis is the process of detecting if an image contains concealed data embedded within its pixel space inserted via a steganography algorithm. The detection of these images is highly motivated by Advanced Persistent Threat (APT) groups, such as APT37 Reaper, commonly utilizing these techniques to transmit malicious shellcode to perform further post-exploitation activity on a compromised host. Performing detection has become increasingly difficult due to modern steganography algorithms advancing at a greater rate than the steganalysis techniques designed to combat them. The task of detection is challenging due to modern steganography techniques that embed messages into images with only minor modifications to the original content which varies from image to image. In this paper, we pipeline Spatial Rich Models (SRM) feature extraction, Principal Component Analysis (PCA), and Deep Neural Networks (DNNs) to perform image steganalysis. Our proposed model, Neural Spatial Rich Models (NSRM) is an ensemble of DNN classifiers trained to detect 4 different state-of-the-art steganography algorithms at 5 different embedding rates, allowing for an end-to-end model which can be more easily deployed at scale. Additionally our results show our proposed model outperforms other current state-of-the-art neural network based image steganalysis techniques. Lastly, we provide an analysis of the current academic steganalysis benchmark dataset, BOSSBase, as well as performance of detection of steganography in various file formats with the hope of moving image steganalysis algorithms towards the point they can be utilized in actual industry applications.
Catalytic asymmetric heterogeneous aziridination of alkenes using zeolite CuHY with [N-( p-tolylsulfonyl)imino]phenyliodinane as nitrene donor (1999)

Copper-exchanged zeolite Y (CuHY) is found to be a highly effective heterogeneous catalyst for the aziridination of alkenes using [N-(p-tolylsulfonyl)imino]phenyliodinane (PhINTs) as the nitrogen source. Exchange of zeolite Y with other cations (Ag+, Co2+, Fe3+, Mg2+, Ni2+, Zn2+) was found to be ineffective. This is considered to be due to the ability of these metals to catalyse the breakdown of the PhINTs reagent into iodobenzene and toluene sulfonamide. Modification of the CuHY catalyst with bis(oxazolines) leads to preparation of the first heterogeneous enantioselective aziridination catalyst and the results showing the effect of temperature and modifier concentration are described and discussed. A pyridine-bridged bis(oxazoline) was observed to give the highest enantioselectivity of 61% ee for the aziridination of styrene using acetonitrile as solvent and at –10 °C.
Triggering Passively Q-switched Microlasers (2005)

A passively Q-switched microlaser at 266nm is operated in triggered mode : for repetition rates randomly varying between 10Hz and 1kHz, the output performances (pulse energy and build-up time) exhibit remarkably small variations. Critical design parameters are reviewed, and detailed characterization of a prototype laser head is reported. Its performances are well suited for detection of biological aerosol with UV excited fluorescence, that do not require nanosecond scale timing jitter but need low cost and compact solid-state lasers.
The Structures of Minor Components of the Fortimicin Complex (1980)

The fortimicins are a new group of potent aminoglycoside antibiotics discovered under a joint research agreement between the Kyowa Hakko Kogyo Company and Abbott Laboratories. They are produced by fermentation of a novel micromonospora species, M. olivoasterospora (1,2). The structures of a number of fortimicins have already been elucidated by Egan, et. al. (3) and Shirahata, et. al. (4) and that of fortimicin B confirmed by an x-ray determination (5) on a crystal of the free base. They consist of ψ-disaccharides of purpurosamine C or 6-epi-purpurosamine B and a novel 1,4-diaminocyclitol of chirostereochemistry. One oxygen and adjacent nitrogen of the cyclitol each carry methyl groups. Fortimicins A and D each bear a glycyl group attached in an amide linkage with the secondary amine, and fortimicin C has a hydantoic acid residue in this position. From the fermentation beers of Micromonospora olivoasterospora a large number of minor fortimicins have been isolated
Hyperspectral Imager with Folded Metasurface Optics (2019)

Hyperspectral imaging is a key characterization technique used in various areas of science and technology. Almost all implementations of hyperspectral imagers rely on bulky optics including spectral filters and moving or tunable elements. Here, we propose and demonstrate a line-scanning folded metasurface hyperspectral imager (HSI) that is fabricated in a single lithographic step on a 1 mm thick glass substrate. The HSI is composed of four metasurfaces, three reflective and one transmissive, that are designed to collectively disperse and focus light of different wavelengths and incident angles on a focal plane parallel to the glass substrate. With a total volume of 8.5 mm^3, the HSI has spectral and angular resolutions of ∼1.5 nm and 0.075°, over the 750–850 nm and −15° to +15° degree ranges, respectively. Being compact, light weight, and easy to fabricate and integrate with image sensors and electronics, the metasurface HSI opens up new opportunities for utilizing hyperspectral imaging where strict volume and weight constraints exist. In addition, the demonstrated HSI exemplifies the utilization of metasurfaces as high-performance diffractive optical elements for implementation of advanced optical systems.
Electrolytes for Low-Temperature Operation of Li-CFx Cells (2009)

A report describes a study of electrolyte compositions selected as candidates for improving the low-temperature performances of primary electrochemical cells that contain lithium anodes and fluorinated carbonaceous (CFx) cathodes. This study complements the developments reported in Additive for Low-Temperature Operation of Li-(CF)n Cells (NPO- 43579) and Li/CFx Cells Optimized for Low-Temperature Operation (NPO- 43585), which appear elsewhere in this issue of NASA Tech Briefs. Similar to lithium-based electrolytes described in several previous NASA Tech Briefs articles, each of these electrolytes consisted of a lithium salt dissolved in a nonaqueous solvent mixture. Each such mixture consisted of two or more of the following ingredients: propylene carbonate (PC); 1,2-dimethoxyethane (DME); trifluoropropylene carbonate; bis(2,2,2-trifluoroethyl) ether; diethyl carbonate; dimethyl carbonate; and ethyl methyl carbonate. The report describes the physical and chemical principles underlying the selection of the compositions (which were not optimized) and presents results of preliminary tests made to determine effects of the compositions upon the low-temperature capabilities of Li-CFx cells, relative to a baseline composition of LiBF4 at a concentration of 1.0 M in a solvent comprising equal volume parts of PC and DME.
An acrolein production route from ethanol and methanol mixtures over FeMo-based catalysts (2017)

Acrolein is the simplest unsaturated aldehyde, which – due to its high reactivity – has found application as an intermediate in the chemical industry.
Object-level ranking (2005)

In contrast with the current Web search methods that essentially do document-level ranking and retrieval, we are exploring a new paradigm to enable Web search at the object level. We collect Web information for objects relevant for a specific application domain and rank these objects in terms of their relevance and popularity to answer user queries. Traditional PageRank model is no longer valid for object popularity calculation because of the existence of heterogeneous relationships between objects. This paper introduces PopRank, a domain-independent object-level link analysis model to rank the objects within a specific domain. Specifically we assign a popularity propagation factor to each type of object relationship, study how different popularity propagation factors for these heterogeneous relationships could affect the popularity ranking, and propose efficient approaches to automatically decide these factors. Our experiments are done using 1 million CS papers, and the experimental results show that PopRank can achieve significantly better ranking results than naively applying PageRank on the object graph.
Characterization of viscoelastic media using reverberant shear wave autocorrelation estimator (2022)

The reverberant shear wave (RSW) technique offers a promising framework for elastography. In this study, to characterize fibrotic fatty livers at different fibrotic stages, we employed an autocorrelation (AC) estimator within the RSW framework to evaluate shear wave speed (SWS) of viscoelastic media. To this end, we utilized both simulation and experimental approaches and excited the RSW field in a medium within each approach at the frequency of 150 Hz: (i) the finite element (FE) simulation of a RSW field in a 3D model of a whole organ fatty liver and (ii) the RSW experiments on two castoroil- in-gelatin phantoms fabricated in the lab. In the FE simulations, to represent a more realistic liver model, a thin adipose fat layer and a muscle layer were added as viscoelastic power-law materials on top of the liver model. The SWS estimation from the RSW simulation was compared with predictions from the theory of composite media for verification. For the RSW experiments on phantoms, the SWS estimations were compared with the SWS results obtained from performing the stress relaxation test as an independent modality. The simulation results showed that the RSW-based AC estimator provides good estimates of SWS, within >90% accuracy compared with theory. Also, the RSW estimator results from the phantom experiments at different background stiffness levels provided some experimental support for the utility of the RSW estimator. These results demonstrated that the AC estimator is sensitive to the changes in viscoelastic properties of viscoelastic media.
Haptic holography: a primitive computational plastic (2003)

We describe our work on haptic holography, a combination of computational modeling and multimodal spatial display, which allows a person to see, feel, and interact with three-dimensional freestanding holographic images of material surfaces. In this paper, we combine various holographic displays with a force-feedback device to render multimodal images with programmatically prescribed material properties and behavior. After a brief overview of related work which situates visual display within the manual workspace, we describe our holo-haptic approach and survey three implementations, Touch, Lathe, and Poke, each named for the primitive functional affordance it offers. In Touch, static holographic images of simple geometric scenes are reconstructed in front of the hologram plane, and coregistered with a force model of the same geometry. These images can be visually inspected and haptically explored using a handheld interface. In Lathe, a holo-haptic image can be reshaped by haptic interaction in a dynamic but constrained manner. Finally in Poke, using a new technique for updating interference-modeled holographic fringe patterns, we render a holo-haptic image that permits more flexible interactive reshaping of its reconstructed surface. We situate this work within the context of related research and describe the strengths, shortcomings, and implications of our approach.
Tracking the Mammary Architectural Features and Detecting Breast Cancer with Magnetic Resonance Diffusion Tensor Imaging (2014)

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of life and survival of breast cancer patients. In this paper a new approach for the detection of breast cancer is described, based on tracking the mammary architectural elements using diffusion tensor imaging (DTI). The paper focuses on the scanning protocols and image processing algorithms and software that were designed to fit the diffusion properties of the mammary fibroglandular tissue and its changes during malignant transformation. The final output yields pixel by pixel vector maps that track the architecture of the entire mammary ductal glandular trees and parametric maps of the diffusion tensor coefficients and anisotropy indices. The efficiency of the method to detect breast cancer was tested by scanning women volunteers including 68 patients with breast cancer confirmed by histopathology findings. Regions with cancer cells exhibited a marked reduction in the diffusion coefficients and in the maximal anisotropy index as compared to the normal breast tissue, providing an intrinsic contrast for delineating the boundaries of malignant growth. Overall, the sensitivity of the DTI parameters to detect breast cancer was found to be high, particularly in dense breasts, and comparable to the current standard breast MRI method that requires injection of a contrast agent. Thus, this method offers a completely non-invasive, safe and sensitive tool for breast cancer detection.
Multiple description lattice vector quantization: variations and extensions (2002)

Multiple description lattice vector quantization (MDLVQ) is a technique for two-channel multiple description coding. We observe that MDLVQ, in the form introduced by Servetto et al. (1999), is inherently optimized for the central decoder; i.e., for zero probability of a lost description. With a nonzero probability of description loss, performance is improved by modifying the encoding rule (using nearest neighbors with respect to "multiple description distance") and by perturbing the lattice codebook. The perturbation maintains many symmetries and hence does not significantly affect encoding or decoding complexity. An extension to more than two descriptions with attractive decoding properties is outlined.
Modeling and Analysis of an Electric Power Steering System (1998)

<div class="htmlview paragraph">An Electric Power Steering (EPS) System will be considered in this report. The modeling of this dynamic system will be achieved with both simplicity and usability taken into account. As such, a Reduced Order Model that reveals the important dynamic distinctions of the system will be developed from a more complex one. This model will be used to analyze various closed loop effects such as torque performance, disturbance rejection, noise rejection, road feel, and stability. These fundamental effects (compromises) are used toward the design of a desired control system. This modeling philosophy together with a comprehensive understanding of system compromises is essential to an optimized EPS system.</div>