gebhart/patrepeval huggingface dataset:
High-Resolution Three-Dimensional Extracellular Recording of Neuronal Activity With Microfabricated Electrode Arrays (2008)

Microelectrode array recordings of neuronal activity present significant opportunities for studying the brain with single-cell and spike-time precision. However, challenges in device manufacturing constrain dense multisite recordings to two spatial dimensions, whereas access to the three-dimensional (3D) structure of many brain regions appears to remain a challenge. To overcome this limitation, we present two novel recording modalities of silicon-based devices aimed at establishing 3D functionality. First, we fabricated a dual-side electrode array by patterning recording sites on both the front and back of an implantable microstructure. We found that the majority of single-unit spikes could not be simultaneously detected from both sides, suggesting that in addition to providing higher spatial resolution measurements than that of single-side devices, dual-side arrays also lead to increased recording yield. Second, we obtained recordings along three principal directions with a multilayer array and demonstrated 3D spike source localization within the enclosed measurement space. The large-scale integration of such dual-side and multilayer arrays is expected to provide massively parallel recording capabilities in the brain.
Improved Error Protection for Uplink Control Signaling in 3GPP-LTE via Complex-Field Coding (2010)

We study the uplink control signaling in 3GPP-Long Term Evolution (LTE) systems. Specifically, we propose a precoding method that uses complex-field coding (CFC) to improve the performance of the PUCCH format 2 control signaling. In the case of perfect channel state information (CSI) at the receiver and with a single receive antenna, the proposed method offers significant gains compared to the coding currently used in 3GPP-LTE. However the gains are marginal with two receive antennas. In order to examine the impact of channel estimation errors, we also derive the optimal detector for the case of imperfect receiver CSI, both for conventional coding and for the proposed CFC method.
Characterization of normal dispersion mode-locked Yb-doped fiber laser with birefringent spectral filter (2017)

We present an investigation into the characteristics of a normal dispersion mode-locked Yb-doped fiber laser using a birefringent plate as a spectral filter. Before implementing mode locking using a birefringent plate, the transmission characteristics of the birefringent plate were analyzed. It was observed that the center wavelength and the full width at half maximum (FWHM) of the transmitted light varied according to the azimuthal angle and optical axis of the birefringent plate. The total dispersion value of the laser cavity was 0.04673 ps2 at a center wavelength of 1.03 μm. The mode locking was therefore achieved in the normal-dispersion region. The total cavity length of the Yb-doped fiber laser was about 1.9 m including free space, and the repetition rate of the mode-locked pulse was ∼104.2 MHz. The FWHM of the optical spectrum was ∼18.09 nm, and the pulse width measured by an autocorrelator was ∼1.71 ps assuming a Gaussian pulse shape. To obtain the transform limited pulse, a pulse was compressed using a pair of diffraction gratings outside the cavity. We achieved a compressed pulse of ∼148 fs assuming a Gaussian pulse shape. The output characteristics of the mode-locked Yb-doped fiber laser were observed while rotating the optical axis of the birefringent plate in the laser cavity. It was found that the center wavelength and FWHM of the optical spectrum could be varied by rotating the optical axis of the birefringent plate. The center wavelength changed by about 18.7 nm from 1026.9 to 1045.6 nm during rotation of the optical axis of the birefringent plate.
Broadband, Angle- and Polarization-Invariant Antireflective and Absorbing Films by a Scalable Synthesis of Monodisperse Silicon Nanoparticles (2022)

Optically induced magnetic resonances (OMRs) are highly tunable scattering states that cannot be reproduced in systems that only support electric resonances, such as in metals, lossy, or low-index materials. Despite offering unique scattering and coupling behavior, the study of OMRs in thin films has been limited by synthesis and simulation constraints. We report on the absorption and scattering response of OMR-based thin films composed of monodisperse crystalline silicon nanoparticles synthesized using a scalable nonthermal plasma growth technique and tractable simulation framework. The synthesis is solvent and ligand free, ensuring minimal contamination, and crystalline particles form with high yield and a narrow size distribution at close to room temperature. Using a scalable high-throughput deposition method, we deposit random particle films, without the need of a solid host matrix, showing near complete blackbody absorption at the collective OMR. This is achieved using 70% less material than an optimized antireflective-coated crystalline silicon thin film. The film exhibits strongly directional forward scattering with very low reflectivity, thus giving rise to angle- and polarization-insensitive antireflection properties across the visible spectrum. We find that, while commonly used effective medium models cannot capture the optical response, a modified effective medium accounting for multipole resonances and interparticle coupling shows excellent agreement with experiment. The effective permittivity and permeability are written in a mode and cluster resolved form, providing useful insight into how individual resonances and nanoparticle clusters affect the overall film response. Electric and magnetic-mode coupling show dramatically different behavior, resulting in uniquely different spectral broadening.
A Matched CBCT Projector-Backprojector Based on the Convolution of B-splines (2020)

International audience
IL-2/CD25: A Long-Acting Fusion Protein That Promotes Immune Tolerance by Selectively Targeting the IL-2 Receptor on Regulatory T Cells (2018)

Low-dose IL-2 represents an immunotherapy to selectively expand regulatory T cells (Tregs) to promote tolerance in patients with autoimmunity. In this article, we show that a fusion protein (FP) of mouse IL-2 and mouse IL-2Rα (CD25), joined by a noncleavable linker, has greater in vivo efficacy than rIL-2 at Treg expansion and control of autoimmunity. Biochemical and functional studies support a model in which IL-2 interacts with CD25 in the context of this FP in <i>trans</i> to form inactive head-to-tail dimers that slowly dissociate into an active monomer. In vitro, IL-2/CD25 has low sp. act. However, in vivo IL-2/CD25 is long lived to persistently and selectively stimulate Tregs. In female NOD mice, IL-2/CD25 administration increased Tregs within the pancreas and reduced the instance of spontaneous diabetes. Thus, IL-2/CD25 represents a distinct class of IL-2 FPs with the potential for clinical development for use in autoimmunity or other disorders of an overactive immune response.
Reference governors: Theoretical Extensions and Practical Applications. (2015)

As systems become downsized and operate at the limits of performance, control systems must be designed to ensure that system state and control constraints are satisfied; however, conventional control schemes are often designed without taking constraints into account. Reference governors and the related, more flexible, extended command governors are add-on, constraint enforcement schemes that modify reference signals to conventionally designed, closed-loop systems for the purpose of enforcing output constraints. The focus of this dissertation is on theoretical and methodological extensions of reference and extended command governors, and on their practical applications. Various theoretical results are presented. The first is the development of reduced-order reference and extended command governors, which enables constraint enforcement schemes using simplified models. The second, related development is that of reference governors for decentralized systems that may or may not communicate over a network. The third considers command governors with penalty functions that are used to enforce prioritized sets of constraints, as well as reference governors that are applied to a sequence of prioritized references. The fourth considers the often overlooked case of applying reference governors to linear systems subject to nonlinear constraints; various formulations of constraints are considered, including quadratic constraints and mixed logical-dynamic constraints. The final theoretical development considers using contractive sets to design reference governors for systems with time-varying reference inputs or subject to time-dependent constraints. Numerical simulations are used throughout to illustrate the theoretical advances. The design of reference governor schemes for three systems arising in practical applications is also presented. The first scheme enforces compressor surge constraints for turbocharged gasoline engines, ensuring that the compressor does not surge. The second scheme is designed for an airborne wind energy system that is subject to various flight constraints including constraints on altitude and angle of attack. The third and final scheme is designed for the constrained control of spacecraft attitude, whose discrete-time dynamics evolve on the configuration space SO(3). In the case of the first application, experimental vehicle results are reported that show successful avoidance of surge. For the other two applications, nonlinear model simulation results are reported that show enforcement of system constraints.
Hepatitis C Virus Core Inhibits the Fas-mediated p38 Mitogen Activated Kinase Signaling Pathway in Hepatocytes (2002)

The p38 mitogen activated kinase (MAPK) signaling pathway plays an essential role in regulating many cellular processes, including inflammation, cell differentiation, and cell death. Here, we report that the hepatitis C virus (HCV) core inhibits the Fas-mediated p38 signaling pathway. The Fas-mediated p38 activation is suppressed in core-expressing HepG2 cell lines, as well as in the hepatocytes of transgenic mice. In addition, core protein blocked the Fas-mediated activation of apoptosis signal-regulating kinase 1 (ASK1), a major upstream MAPKKK of p38. Treatment of a specific p38 inhibitor (SB203580) or overexpression of a kinase-defective mutant, ASK1 (K709R), promoted Fas-mediated cell death in HepG2 cells. This suggests that the p38 and ASK1 activation is required for cell survival against Fas-mediated cell death. In addition, we observed that the HCV core protein enhances Fas-mediated liver injury and lethality in transgenic mice. Collectively, our findings suggest that the HCV core inhibits the Fas-mediated p38 signaling pathway, which results in accelerated Fas-mediated cell death.
Resolving Nano Recording Bits on Phase-Change Rewritable Optical Disk (2005)

Nano-recording bits on DVD+RW were recorded by a dynamic optical disk tester and studied by a high spatial resolution conductive-AFM with excellent contrast. Writing strategy and energy dose of nano-recorded bits are studied in detail.
ChemInform Abstract: Fossil Fuel Decarbonization: In the Quest for Clean and Lasting Fossil Energy (2012)

Abstract Review: 195 refs.
An Autonomous Proximity Navigation Testbed for Nanosatellites (2014)

The goal of this work is to develop techniques and tools to enhance small-spacecraft in-orbit autonomy. The focus is on developing perception and control algorithms to enable autonomous proximity operations, and performing preliminary validation in a laboratory air-bearing testbed. To achieve this, we have developed CubeSat engineering models equipped with a simple cold-gas propulsion system, on-board vision-based sensing and embedded computer for perception and control algorithms, and integrated them in the air-bearing testbed. Basic point-to-point autonomous navigation and obstacle avoidance tasks on such a planar environment have been successfully demonstrated.
Pegfilgrastim support for full delivery of BEACOPP-14 chemotherapy for patients with high-risk Hodgkin's lymphoma: results of a phase II study. (2006)

The primary endpoint of this feasibility study was to determine whether pegfilgrastim support could enable the delivery of the full dose of BEACOPP chemotherapy every 14 days on schedule. Forty-one patients with high-risk Hodgkin's lymphoma were randomized to receive pegfilgrastim (6 mg) on day 4 or 8 of each cycle. Eighty-one percent of cycles administered were delivered at full dose and on schedule (FDOS). Response was retrospectively assessed in 27 patients at 6 months; 23 of these 27 patients (85%) achieved a complete response and one (4%) achieved a partial response. Toxicities were mostly moderate in intensity. These results support the feasibility of delivering full dose, on schedule BEACOPP-14, chemotherapy with pegfilgrastim support.
Effect of air mass on carrier losses in bifacial silicon heterojunction solar cells (2021)

We investigate the effect of incident spectra on current loss as a function of depth and voltage into high efficiency textured bifacial silicon heterojunction solar cells. We integrate thin-film ellipsometry measurements with a 3D optical model and a 2D electronic model and validate our model with measurements of external quantum efficiency and Suns-Voc. For front illumination at normal incidence, an increasing air mass of AM1.5 to 10 reduces current density loss due to parasitic absorption in ITO and a-Si:H from 8.1% to 4.0%, and increases recombination loss at maximum power from 4.2% to 4.7%, resulting in an overall increase in collected current (88.2% to 90.5%). Cell performance metrics are summarized as a function of air mass, with efficiency peaking at AM5.0 for front illuminated and rear illuminated cells with an albedo of unity. We further demonstrate the impact of spectra on bifacial efficiency by calculating rear-side performance with the spectral albedo of dry grass. Overall, current-collection and efficiency trends emphasize the importance of considering spectral effects in energy yield models. These results are of particular importance for cell structures with high bifaciality and significant spectral albedo contributions, locations with large proportions of diffuse light, and high air mass locations as in mid-to-high latitudes.
Nanoelectrode-mediated single neuron activation (2020)

Elucidating cellular dynamics at the level of a single neuron and its associated role within neuronal circuits is essential for interpreting the complex nature of the brain. To investigate the operation of neural activity within its network, it is necessary to precisely manipulate the activation of each neuron and verify its propagation path via the synaptic connection. In this study, by exploiting the intrinsic physical and electrical advantages of a nanoelectrode, a vertical nanowire multi electrode array (VNMEA) is developed as a neuronal activation platform presenting the spatially confined effect on the intracellular space of individual cells. VNMEA makes a distinct difference between the interior and exterior cell potential and the current density, deriving the superior effects on activating Ca2+ responses compared to extracellular methods under the same conditions, with about 2.9-fold higher amplitude of Ca2+ elevation and a 2.6-fold faster recovery rate. Moreover, the synchronized propagation of evoked activities is shown in connected neurons implying cell-to-cell communications following the intracellular stimulation. The simulation and experimental consequences prove the outstanding property of temporal/spatial confinement of VNMEA-mediated intracellular stimulation to activate a single neuron and show its potential in localizing spiking neurons within neuronal populations, which may be utilized to reveal the connection and activation modalities of neural networks.
Guided evolutionary strategies: Augmenting random search with surrogate gradients (2018)

Many applications in machine learning require optimizing a function whose true gradient is unknown, but where surrogate gradient information (directions that may be correlated with, but not necessarily identical to, the true gradient) is available instead. This arises when an approximate gradient is easier to compute than the full gradient (e.g. in meta-learning or unrolled optimization), or when a true gradient is intractable and is replaced with a surrogate (e.g. in certain reinforcement learning applications, or when using synthetic gradients). We propose Guided Evolutionary Strategies, a method for optimally using surrogate gradient directions along with random search. We define a search distribution for evolutionary strategies that is elongated along a guiding subspace spanned by the surrogate gradients. This allows us to estimate a descent direction which can then be passed to a first-order optimizer. We analytically and numerically characterize the tradeoffs that result from tuning how strongly the search distribution is stretched along the guiding subspace, and we use this to derive a setting of the hyperparameters that works well across problems. Finally, we apply our method to example problems, demonstrating an improvement over both standard evolutionary strategies and first-order methods (that directly follow the surrogate gradient). We provide a demo of Guided ES at https://github.com/brain-research/guided-evolutionary-strategies
A Signal Adaptive Prediction Filter for Video Coding Using Directional Total Variation: Mathematical Framework and Parameter Selection (2020)

In this paper we combine video compression and modern image processing methods. Iterative filter methods for prediction signals based on classic inpainting methods are introduced and extensive parameter tests are described. In order to construct an alternative prediction filter for video coding, techniques originally employed for inpainting are applied. Thereby, the structures of the underlying prediction were incorporated into the filter construction making it signal adaptive. The resulting optimization problem is solved using the so-called Alternating Direction Method of Multipliers (ADMM). The undertaken novel parameter tests are described and it is shown that they improve the coding efficiency of the tool. The suggested filter is embedded into a software based on HEVC with additional QTBT (Quadtree plus Binary Tree) and MTT (Multi-Type-Tree) block structure. Overall, the proposed filter method obtains average bitrate savings of 1.35% at an average encoder runtime increase of 28% and decoder runtime increase of 38%. UHD test sequences achieve bitrate savings of up to 3.66% for Random Access.
Effect of Ohmic Pretreatment on the Drying Rate of Grapes and Adsorption Isotherm of Raisins (2005)

Abstract Effects of ohmic pretreatment on the drying rates of seedless red grapes and adsorption isotherms of the raisins produced were investigated. The treated grape samples were heated in a medium containing 2% citric acid to a final medium temperature of 60oC using an alternating current at 14 V/cm field strength and 30 Hz, 60 Hz, and 7.5 kHz frequencies. Results of this study reveal that the drying rate of the grapes was significantly increased by the ohmic pretreatment, especially at low electrical frequencies. The effect of the ohmic pretreatment on equilibrium moisture content of the raisins produced was evident at 0.75 or higher water activities but there was no or limited effect at low to moderate water activities.
Modelling plasticity of Ni3Al-based L12intermetallic single crystals. I. Anomalous temperature dependence of the flow behaviour§ (2007)

Abstract A comprehensive mechanism-based crystallographic constitutive model has been developed for L12-structured Ni3Al-based intermetallic single crystals. This model represents the unusual thermomechanical behaviours of Ni3Al, such as the anomalous temperature dependence of both the flow stress and strain-hardening rate (SHR), the strain dependence of these anomalous behaviours and an orientation-dependent tension–compression asymmetry. The model framework was based on two major contributions to plastic flow, namely the repeated cross-slip exhaustion and athermal defeat of screw-character dislocations, and the motion of macro-kinks (MKs). The contribution of irreversible obstacle storage was incorporated into the constitutive formulations as a resistance against the glide of MKs. The model was implemented in a finite element method numerical framework, and the simulation results showed qualitative agreement with experimental observations. §This paper is dedicated to Dr. Peter M. Hazzledine (1940–2005), one of few pioneers who brought the unique dislocation behaviour of L12 intermetallics to scientific attention. Acknowledgements The present work was supported by the U.S. Defense Advanced Research Projects Agency and the Air Force Office of Scientific Research. YSC and TAP acknowledge support from the Materials and Manufacturing Directorate under contract #FA8650-04-D-5233 F33615-96-C-5258 and F33615-01-5214. The authors acknowledge fruitful discussion with Drs. S. Rao, UES, Inc, and C. Woodward, AFRL/MLLM. The computations described in this study were performed using computer resources at the Ohio Supercomputer Centre (grant #'s PAS0191 and PAS0647) with the collaboration of Professors S. Ghosh and G. Daehn of The Ohio State University. Notes §This paper is dedicated to Dr. Peter M. Hazzledine (1940–2005), one of few pioneers who brought the unique dislocation behaviour of L12 intermetallics to scientific attention.
Biased reconstruction of wavelet coefficients in JPEG2000 decoding (2003)

Lossy wavelet compression with JPEG2000 results in the loss of information through coefficient quantization. When decoding a lossy JPEG2000 compressed image, the exact original value of a quantized coefficient is unknown to the decoder, which must try to optimally assign a reconstruction value to the coefficient within the appropriate quantization interval. Typically, JPEG2000 decoders reconstruct a wavelet coefficient at the midpoint of its quantization interval. In this paper, alternative reconstruction algorithms are proposed that utilize statistics accumulated throughout decoding to improve the selection of reconstruction points. Biased reconstruction algorithms are described for zero-quantized coefficients as well as non-zero-quantized coefficients. The computational complexity of the algorithms is also analyzed. At bit rates ranging from 0.25-2 bits per pixel, the proposed techniques yield PSNR improvements on average of 0.1-0.15 dB relative to midpoint reconstruction.
Function Cultivation of Transparent Oxides Utilizing Built‐In Nanostructure (2006)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.