gebhart/patrepeval huggingface dataset:
Mitigation of negative delay via half CP shift (2016)

The purpose of Cyclic Prefix (CP) is vital necessity in today's 4G technology. 4G Technology such as Long Tern Evolution (LTE) and Worldwide Interoperability for Microwave Access (WIMAX) function on the principle of Orthogonal Frequency Division Multiplexing (OFDM). When transmitted signals arrive at the receiver by more than one path of different length, the received signals are staggered in time; this is multipath propagation. To mitigate the effect of dispersed channel distortion caused by random channel delay spread, Cyclic Prefix (CP) is introduced to eliminate Inter-Symbol Interference (ISI). However in a scenario of positive delay CP does prove to be useful, but in a case of negative delay, the CP does not aid in the mitigation of ISI considering the FFT window to start at the CP and OFDM symbol boundary. Due to this there can be spillover of the OFDM symbols. Hence causing degradation on the system performance. This paper deals with highlighting the impact of negative delay in technology system and a proposed method to mitigate this issue.
New Cytotoxic Salinosporamides from the Marine Actinomycete Salinispora tropica. (2005)

Abstract For Abstract see ChemInform Abstract in Full Text.
Human Embryonic Stem Cell-Derived Oligodendrocyte Progenitor Cells: Preclinical Efficacy and Safety in Cervical Spinal Cord Injury (2017)

Cervical spinal cord injury (SCI) remains an important research focus for regenerative medicine given the potential for severe functional deficits and the current lack of treatment options to augment neurological recovery. We recently reported the preclinical safety data of a human embryonic cell-derived oligodendrocyte progenitor cell (OPC) therapy that supported initiation of a phase I clinical trial for patients with sensorimotor complete thoracic SCI. To support the clinical use of this OPC therapy for cervical injuries, we conducted preclinical efficacy and safety testing of the OPCs in a nude rat model of cervical SCI. Using the automated TreadScan system to track motor behavioral recovery, we found that OPCs significantly improved locomotor performance when administered directly into the cervical spinal cord 1 week after injury, and that this functional improvement was associated with reduced parenchymal cavitation and increased sparing of myelinated axons within the injury site. Based on large scale biodistribution and toxicology studies, we show that OPC migration is limited to the spinal cord and brainstem and did not cause any adverse clinical observations, toxicities, allodynia, or tumors. In combination with previously published efficacy and safety data, the results presented here supported initiation of a phase I/IIa clinical trial in the U.S. for patients with sensorimotor complete cervical SCI. Stem Cells Translational Medicine 2017;6:1917-1929.
A Promising Evaluation Method of Ultra-Low-Expansion Glasses for the Extreme Ultra-Violet Lithography System by the Line-Focus-Beam Ultrasonic Material Characterization System (2004)

A super-precise method of evaluating the coefficient of thermal expansion (CTE) of ultra-low-expansion glasses was developed using the line-focus-beam ultrasonic material characterization (LFB-UMC) system and was demonstrated for TiO2-doped SiO2 glass. The sensitivity and resolution in the velocity measurement of leaky surface acoustic waves (LSAWs) in CTE were estimated to be 4.40 (ppb/K)/(m/s) and ±0.77 ppb/K for ±2σ (σ: standard deviation) at 225 MHz. LSAW velocity differences caused by different TiO2 concentrations and distributions or striae in the specimens were successfully detected and evaluated, providing two-dimensional information. This ultrasonic method is effective for evaluating ultra-low-expansion glasses needed for extreme ultra-violet lithography (EUVL) systems.
Empirical Tuning of an On-Board Gas Turbine Engine Model for Real-Time Module Performance Estimation (2007)

A practical consideration for implementing a real-time on-board engine component performance tracking system is the development of high fidelity engine models capable of providing a reference level from which performance changes can be trended. Real-time engine models made their advent as State Variable Models (SVM) in the mid-80’s which utilized a piecewise linear model that granted a reasonable representation of the engine during steady state operation and mild transients. Increased processor speeds over the next decade allowed more complex models to be considered, that were a combination of linear and non-linear physics based elements. While the latter provided greater fidelity over both transient operation and the engine operational flight envelope, these models could be further improved to provide the high level of accuracy required for long-term performance tracking, as well as address the issue of engine-to-engine variation. Over time, these models may deviate enough from the actual engine being monitored, as a result of improvements made during an engine’s life cycle such as hardware modifications, bleed and stator vane schedule alterations, cooling flow adjustments, and the like, that the module performance estimations are inaccurate and often misleading. The process described in this paper will address these shortcomings while maintaining the execution speed required for real-time implementation.
Improved zinc oxide surge arresters using high voltage gradient 300 V/mm, 400 V/mm ZnO elements (2000)

Zinc oxide surge arresters using zinc oxide (ZnO) elements have been widely used for insulation coordination in the world's power systems. These ZnO elements have basically reference voltage of about 200 V/mm. Recently, new ZnO elements having about 1.5, 2 times high voltage gradient zinc oxide element have been developed. This paper describes applications of high voltage gradient 300 V/mm ZnO elements to high performance porcelain type surge arresters and oil immersed surge arresters, and 300 V/mm or 400 V/mm ZnO elements to gas insulated tank type surge arresters for power systems. Adequate selection of voltage gradient of ZnO elements makes more compact design of the surge arresters.
Cellulose Ethers (1992)

Functionalization of polysaccharides with silanolate groups, -Si-O-, leads to the formation of a new class of silated polysaccharide derivatives. These polymers are alkali-soluble and self-crosslink upon drying to form water-resistant films. They also exhibit good adhesion to hydroxylic surfaces and crosslink in solution with polyvalent metal ions to form viscoelastic gels. The synthesis and properties of silated hydroxyethylcellulose (SIL-HEC) are described in this article.
Beyond inhibition: lateral modulation of plasticity of feedforward synapses in a spiking model of V1 (2013)

Lateral inhibition is typically used to repel neural receptive fields. Here we introduce an additional learning mechanism that modifies the plasticity for feedforward synapses based on lateral interactions. We show a model, based on evidence from biological recordings[1], in which a heterosynaptic learning rule in conjunction with lateral inhibition introduces competition among neurons for input features.

We demonstrate an STDP learning rule for feedforward connections to a spiking neuron where plasticity is modulated by activity of neighboring neurons. We apply the learning rule to a spiking model of primary visual cortex. In our model, input to V1 cortical neurons comes from the magnocellular pathway of a simulated spiking retina responding to saccades over a natural image. A group of neurons in V1 respond to a particular input feature and convey information that they have spiked to neighboring neurons by way of specialized lateral connections. The connections convey a direct signal of recent spiking activity. Alternatively, lateral inhibitory synapses and the level of inhibition to a neuron can also be used as this signal. If this recent neighbor activity signal is high, feedforward plasticity to the neuron becomes a simple flat depression as opposed to regular exponential STDP, as shown in Figure ​Figure1A.1A. Thus, late spiking neurons are prevented from developing receptive fields similar to those of earlier spiking neurons for a given input feature. This rule in conjunction with lateral inhibition and slow weight updrift ensures competition between neurons for features over a long timescale.



Figure 1

A. Detail of the heterosynaptic rule. Neurons N1 and N2 fire early for the input, and their feedforward synapses undergo normal STDP. They send an activity signal to N3 and N4, whose feedforward synaptic weights are then depressed to prevent learning ...



Our V1 model is built on a spatially distributed grid of single-compartment spiking neurons with parameters configured to model regular spiking cortical pyramidal cells, as detailed in [2]. The model has plastic excitatory feedforward connections and local lateral inhibition between spatially proximal neurons. In our model, we observe a better overall coverage of orientation selectivity of V1 Layer 4 neurons with our heterosynaptic rule than without it. We find a larger range of orientations and less redundancy of receptive field features between neighboring neurons, as shown in Figure ​Figure1B.1B. Such a rule could be used in a generic spiking cortical architecture to enforce independence of neural receptive fields.
Developmental regulation of a mucinlike glycoprotein selectively expressed on natural killer cells. (1993)

Natural killer (NK) cells are CD3:TCR-, CD16+, CD56+ large granular lymphocytes capable of recognizing and eliminating a variety of virus-infected, malignant, and antibody-coated target cells. Two functionally distinct populations of peripheral blood NK cells can be differentiated by their surface expression of an isoform of the neural cell adhesion molecule (CD56). CD56bright NK cells have the attributes of an undifferentiated cell, in that they proliferate in response to exogenous cytokines, but exert poor cytolytic activity. CD56dim NK cells have the attributes of a more differentiated cell, in that they proliferate poorly in response to exogenous cytokines, but are potent cytolytic effector cells. Here we describe the molecular characterization of a NK cell restricted epitope (PEN5) that is selectively expressed on the functionally differentiated CD56dim NK cells. PEN5+ NK cells proliferate poorly in response to interleukin 2 (IL-2), but are potent cytolytic effectors, whereas PEN5- NK cells proliferate in response to IL-2, but are poor cytolytic effectors. Biochemical and immunochemical analyses reveal the PEN5 epitope to be an unusual sulfated poly-N-lactosamine carbohydrate related to keratan sulfate glycosaminoglycans. Immunoprecipitates prepared using a monoclonal antibody reactive with PEN5 include two polydisperse membrane-bound glycoproteins, PEN5 alpha (120-170 kD) and PEN5 beta (210-245 kD). Enzymatic deglycosylation reduces the apparent molecular weight of both PEN5 isoforms by 80-90%, and classifies PEN5 beta as a mucinlike glycoprotein. The surface expression of the PEN5 epitope is downmodulated by stimuli that induce NK cell proliferation, and it is absent from leukemic NK cells of patients with granular lymphocyte proliferative disorder. Taken together, these results indicate that PEN5 is a developmentally regulated poly-N-lactosamine epitope associated with a mucin-type glycoprotein, whose expression is restricted to the population of nonproliferative NK cells fully committed to cytolytic effector function.
The Potential Application of<tex>$rm MgB_2$</tex>Superconducting Magnets in Space (2006)

The low mass density of magnesium diboride (MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) and its high critical temperature make it the ideal candidate for lightweight liquid hydrogen cooled superconducting magnets that are pivotal for space applications, where the cost per kilo to orbit is still such an expensive barrier. The feasibility of MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> magnets strongly depends on the effect of applied stresses during manufacturing and operational procedures. In this work we introduce our research on mechanical properties of PIT processed wires for magnet applications and for the first time we present results on Ti-sheathed MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> wires. Recently we improved our testing capability with new equipment and tested two coils: the first one was a coil with Fe-sheathed wire and the second one, in order to promote the use of this compound for space activities, uses wires with titanium as a sheath material. These wires show similar results to those sheathed with Fe, at 4 K the critical current density J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> is well above 7times10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The Ti-sheathed coil is still under testing
Coverage in Tiered Cellular Networks with Spatial Diversity (2009)

In two-tier networks - comprising a conventional cellular network overlaid with shorter range femtocell hotspots - with universal frequency reuse, the near-far effect from crosstier interference diminishes coverage for users in either tier. Equipping the macrocell and femtocell basestations (BSs) with multiple antennas can enhance robustness against the near-far problem. Given a per-tier outage probability constraint, this work derives coverage radii wherein cross-tier interference bottlenecks cellular and hotspot coverage. Single-user (SU) multiple antenna transmission at each tier is shown to provide significantly superior coverage and spatial reuse relative to multiuser (MU) transmission. We propose a decentralized carrier sensing approach to regulate femtocell transmission powers for ensuring reliable cellular coverage. Simulations using typical path loss scenarios show that our interference management strategy provides reliable cellular coverage with about 60 femtocells per cellsite.
Stimulation of hepatic glutathione formation by administration of L-2-oxothiazolidine-4-carboxylate, a 5-oxo-L-prolinase substrate. (1981)

5-Oxo-L-prolinase, the enzyme that catalyzes the conversion of 5-oxo-L-proline to L-glutamate coupled to the cleavage of ATP to ADP and Pi, also acts on L-2-oxothiazolidine-4-carboxylate (an analog of 5-oxoproline in which the 4-methylene moiety is replaced by sulfur) and ATP to yield cysteine and ADP. The enzyme, which exhibits an affinity for the analog similar to that for the natural substrate, is inhibited by the analog in vitro and in vivo. L-2-oxothiazolidine-4-carboxylate thus serves as a potent inhibitor of the gamma-glutamyl cycle at the step of 5-oxoprolinase. Administration of L-2-oxothiazolidine-4-carboxylate to mice that had been depleted of hepatic glutathione led to restoration of normal hepatic glutathione levels. Since L-2-oxothiazolidine-4-carboxylate is an excellent substrate of the enzyme, it may serve as an intracellular delivery system for cysteine and thus has potential as a therapeutic agent for conditions in which there is depletion of hepatic glutathione.
A geometric perspective on time-of-flight camera design (Conference Presentation) (2019)

The depth resolution achieved by a continuous wave time-of-flight (C-ToF) imaging system is determined by the coding (modulation and demodulation) functions that it uses. We present a mathematical framework for exploring and characterizing the space of C-ToF coding functions in a geometrically intuitive space. Using this framework, we design families of novel coding functions that are based on Hamiltonian cycles on hypercube graphs. The proposed Hamiltonian coding functions achieve up to an order of magnitude higher resolution as compared to the current state-of-the-art. Using simulations and a hardware prototype, we demonstrate the performance advantages of Hamiltonian coding in a wide range of imaging settings.
Text-Free User Interfaces for Illiterate and Semiliterate Users (2007)

We describe work toward the goal of a user interface (UI) designed such that even novice, illiterate users require absolutely no intervention from anyone at all to use. Our text-free UI is based on many hours of ethnographic design conducted in collaboration with a community of illiterate domestic laborers in three Bangalore slums. An ethnographic design process was used to understand what kind of application subjects would be interested in, how they respond to computing technology, and how they react to specific UI elements. We built two applications using these principles, one for job search for domestic laborers and another for a generic map that could be used for navigating a city. The resulting designs are based on key lessons that we gained through the design process. This article describes the design process, the design principles, which evolved out of the process, the final application designs, and results from initial user testing. Our results confirm previous work that emphasizes the need for semiabstracted graphics and voice feedback, but we additionally find that some aspects of design for illiterate users that have been previously overlooked (such as a consistent help feature). Results also show that the text-free designs are strongly preferred over standard text-based interfaces by the communities which we address and that they are potentially able to bring even complex computer functions within the reach of users who are unable to read. (c) 2007 by The Massachusetts Institute of Technology.
Highly Porous Acrylonitrile-Based Submicron Particles for UO<sub>2</sub><sup>2+</sup> Absorption in an Immunosensor Assay (2011)

Our laboratory has previously reported an antibody-based assay for hexavalent uranium (UO(2)(2+)) that could be used on-site to rapidly assess uranium contamination in environmental water samples (Melton, S. J.; et al. Environ. Sci. Technol. 2009, 43, 6703-6709). To extend the utility of this assay to less-characterized sites of uranium contamination, we required a uranium-specific adsorbent that would rapidly remove the uranium from groundwater samples, while leaving the concentrations of other ions in the groundwater relatively unaltered. This study describes the development of hydrogel particles containing amidoxime groups that can rapidly and selectively facilitate the uptake of uranyl ions. A miniemulsion polymerization technique using SDS micelles was employed for the preparation of the hydrogel as linked submicrometer particles. In polymerization, acrylonitrile was used as the initial monomer, ethylene glycol dimethacrylate as the crosslinker and 2-hydroxymethacrylate, 1-vinyl-2-pyrrolidone, acrylic acid, or methacrylic acid were added as co-monomers after the initial seed polymerization of acrylonitrle. The particles were characterized by transmission electron spectroscopy, scanning electron microscopy (SEM) and cryo-SEM. The amidoximated particles were superior to a commercially available resin in their ability to rapidly remove dissolved UO(2)(2+) from spiked groundwater samples.
Spongistatins as Tubulin Targeting Agents (2001)

Recently identified novel agents that disrupt tubulin polymerization include synthetic spiroketal pyrans (SPIKET) targeting the spongistatin binding site of b-tubulin. These agents exhibit anticancer activity by disrupting normal mitotic spindle assembly and cell division as well as inducing apoptosis. At nanomolar concentrations, the SPIKET compound SPIKET-P caused tubulin depolymerization in cell-free turbidity assays and exhibited potent cytotoxic activity against cancer cells as evidenced by destruction of microtubule organization, and prevention of mitotic spindle formation in human breast cancer cells. SPIKET compounds represent a new class of tubulin targeting agents that show promise as anti-cancer drugs.
Characterization of broadband few-cycle laser pulses with the d-scan technique (2012)

We present an analysis and demonstration of few-cycle ultrashort laser pulse characterization using second-harmonic dispersion scans and numerical phase retrieval algorithms. The sensitivity and robustness of this technique with respect to noise, measurement bandwidth and complexity of the measured pulses is discussed through numerical examples and experimental results. Using this technique, we successfully demonstrate the characterization of few-cycle pulses with complex and structured spectra generated from a broadband ultrafast laser oscillator and a high-energy hollow fiber compressor.
Diels−Alder Trapping of Photochemically Generated <i>o</i>-Quinodimethane Intermediates:  An Alternative Route to Photocured Polymer Film Development (2005)

Photolysis of o-methylphenyl ketones generates o-quinodimethane intermediates that can be trapped in situ by dienophiles through Diels−Alder cycloadditions. This well-known photochemical process is applied to a series of six new photoreactive monomers containing bis(o-methylphenyl ketone) functionalities combined with diacrylate and triacrylate esters for the development of acrylic ester copolymer blends. Irradiation of cyclohexanone solutions of the bis(o-methylphenyl ketone)s and acrylate esters produce thin polymer films. Solid state 13C NMR data indicated 47−100% reaction of the bis(o-methylphenyl ketone)s, depending on experimental conditions, to yield the desired products. DSC and TGA analyses were performed to determine the glass transition temperature, Tg, and onset of decomposition, Td, of the resulting polymer films. A statistical “design of experiments” approach was used to obtain a systematic understanding of the effects of experimental variables on the extent of polymerization and the final polymer properties.
Enzymatic production of ascorbic acid-2-phosphate. (1990)

Microorganisms that produce ascorbic acid-2-phosphate (AsA2P) from ascorbic acid (AsA) and ATP were screened from our culture collection. Of 715 strains, three microorganisms, Pseudomonas azotocolligans KY4661, P.paucimobilis KY4084, and an unidentified bacterium KY3132 were selected as AsA2P-producers. When using 50 mg (wet weight) of P. azotocolligans cells per ml as the enzyme source, 3.7 mM AsA2P were produced for 23 hr, from 30 mM AsA and 40 mM ATP. From analytical data of the purified product from the reaction mixture, these microorganisms phosphorylated AsA at the C-2 position specifically.
Combining Spatial Registration With Clutter Filtering for Power-Doppler Imaging in Peripheral Perfusion Applications (2022)

Power-Doppler ultrasonic (PD-US) imaging is sensitive to echoes from blood cell motion in the microvasculature but generally nonspecific because of difficulties with filtering nonblood-echo sources. We are studying the potential for using PD-US imaging for routine assessments of peripheral blood perfusion without contrast media. The strategy developed is based on an experimentally verified computational model of tissue perfusion that simulates typical in vivo conditions. The model considers directed and diffuse blood perfusion states in a field of moving clutter and noise. A spatial registration method is applied to minimize tissue motion prior to clutter and noise filtering. The results show that in-plane clutter motion is effectively minimized. While out-of-plane motion remains a strong source of clutter-filter leakage, those registration errors are readily minimized by straightforward modification of scanning techniques and spatial averaging.