gebhart/patrepeval huggingface dataset:
Improved accuracy in the estimation of blood velocity vectors using matched filtering (2002)

The blood velocity can be estimated by finding the shift in position of the blood scatterers between subsequent ultrasonic pulse emissions through cross-correlation of the received RF signals. Usually only the velocity component along the beam direction is found. It was shown in a previous paper that the complete velocity vector can be found, if the received signals are focused along lines parallel to the direction of the blood flow. A fairly broad beam is emitted in the approach, and this gives rise to a widening in the profiles of the estimated velocity. To reduce this effect, a focused ultrasound emission is used in this study to decrease the size of the beam. The transverse beam lines are then constructed by using filters matched to the response of the individual channels. The filters matched to the points on the focusing lines are obtained by considering the field response of the employed array transducer. The effect of the processing is studied through simulations with the Field II program. A 64-elements linear array with a center frequency of 3 MHz, pitch of 0.3 mm, and element height of 5 mm is used in the simulations. A parabolic velocity profile is considered for different angles between the flow and the ultrasound beam (30, 45, 60, and 90 degrees). The parabolic flow has a peak velocity of 0.5 m/s and the pulse repetition frequency is 3.5 kHz. Simulating twenty emissions and calculating the cross-correlation using four pulse-echo lines for each estimate, the parabolic flow profile is found with a standard deviation of 0.014 m/s at 45 degrees (corresponding to an accuracy of 2.8%) and 0.022 m/s (corresponding to an accuracy of 4.4%) at 90 degrees, which is transverse to the ultrasound beam.
Prostaglandin F<sub>2</sub>α, but Not Latanoprost, Increases the Ca<sup>2+</sup>Sensitivity of the Pig Iris Sphincter Muscle (2006)

PGF(2)alpha, but not latanoprost, induced Ca(2+) sensitization of the pig iris sphincter muscle in an MLC phosphorylation-dependent manner through the rho-rho kinase pathway. The effect of latanoprost on the Ca(2+) sensitization mechanism was different from that of PGF(2)alpha and was thought to play a beneficial role in glaucoma treatment.
Thalamic model of awake alpha oscillations and implications for stimulus processing (2012)

We describe a unique conductance-based model of awake thalamic alpha and some of its implications for function. The full model includes a model for a specialized class of high-threshold thalamocortical cells (HTC cells), which burst at the alpha frequency at depolarized membrane potentials (~-56 mV). Our model generates alpha activity when the actions of either muscarinic acetylcholine receptor (mAChR) or metabotropic glutamate receptor 1 (mGluR1) agonists on thalamic reticular (RE), thalamocortical (TC), and HTC cells are mimicked. In our model of mGluR1-induced alpha, TC cells are equally likely to fire during any phase of alpha, consistent with in vitro experiments. By contrast, in our model of mAChR-induced alpha, TC cells tend to fire either at the peak or the trough of alpha, depending on conditions. Our modeling suggests that low levels of mGluR1 activation on a background of mAChR agonists may be able to initiate alpha activity that biases TC cells to fire at certain phases of alpha, offering a pathway for cortical control. If we introduce a strong stimulus by increasing the frequency of excitatory postsynaptic potentials (EPSPs) to TC cells, an increase in alpha power is needed to mimic the level of phasing of TC cells observed in vivo. This increased alpha power reduces the probability that TC cells spike near the trough of alpha. We suggest that mAChR-induced alpha may contribute to grouping TC activity into discrete perceptual units for processing, whereas mGluR1-induced alpha may serve the purpose of blocking unwanted stimuli from reaching the cortex.
Comparison of Plantar Loads During Running on Different Overground Surfaces (2012)

The objective of this study is to compare plantar loads during running on different overground surfaces. Fifteen heel-to-toe runners participated in the study. Plantar load data were collected and analyzed using an insole sensor system during running on concrete, synthetic rubber, and grass surfaces at a running speed of 3.8 m/s. Compared with running on concrete surface, running on natural grass showed a lower magnitude of maximum plantar pressure at the total foot (451.8 kPa vs. 401.7 kPa, p = 0.016), lateral midfoot (175.3 kPa vs. 148.0 kPa, p = 0.004), central forefoot (366.3 kPa vs. 336.8 kPa, p = 0.003), and lateral forefoot (290.2 kPa vs. 257.9 kPa, p = 0.004). Moreover, running on natural grass showed a longer relative contact time compared with running on a concrete surface at the central forefoot (81.9% vs. 78.8%, p = 0.017) and lateral forefoot (75.2% vs. 73.1%, p = 0.007). No significant difference was observed in other multiple comparisons. Different surfaces affected the plantar loads while running. The differences may help us to understand potential injury mechanisms.
Cathepsin A in human brain and spleen (<i>Short Communication</i>) (1973)

A striking loss of cathepsin A activity occurs when relatively crude preparations of the enzyme are maintained at even a mildly basic pH value. This may explain the failure of others to detect the enzyme.
Minimum bias multiple taper spectral estimation (1995)

Two families of orthonormal tapers are proposed for multitaper spectral analysis: minimum bias tapers, and sinusoidal tapers {/spl upsisup (k/)}, where /spl upsisub nsup (k/)=/spl radic/(2/(N+1))sin(/spl pi/kn/N+1), and N is the number of points. The resulting sinusoidal multitaper spectral estimate is S/spl circ/(f)=(1/2K(N+1))/spl Sigmasub j=1sup K/|y(f+j/(2N+2))-y(f-j/(2N+2))|/sup 2/, where y(f) is the Fourier transform of the stationary time series, S(f) is the spectral density, and K is the number of tapers. For fixed j, the sinusoidal tapers converge to the minimum bias tapers like 1/N. Since the sinusoidal tapers have analytic expressions, no numerical eigenvalue decomposition is necessary. Both the minimum bias and sinusoidal tapers have no additional parameter for the spectral bandwidth. The bandwidth of the jth taper is simply 1/N centered about the frequencies (/spl plusmn/j)/(2N+2). Thus, the bandwidth of the multitaper spectral estimate can be adjusted locally by simply adding or deleting tapers. The band limited spectral concentration, /spl intsub -wsup w/|V(f)|/sup 2/df of both the minimum bias and sinusoidal tapers is very close to the optimal concentration achieved by the Slepian (1978) tapers. In contrast, the Slepian tapers can have the local bias, /spl intsub - 1/2 sup 1/2 /f/sup 2/|V(f)|/sup 2/df, much larger than of the minimum bias tapers and the sinusoidal tapers.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Reactive processing of thermoset/thermoplastic blends: A potential for injection molding (1996)

Abstract Poly(2,6‐dimethyl‐1,4‐phenylene ether) (PPE) is an engineering plastic with high heat distortion temperature. Melt processing of neat PPE is usually accompanied with thermal degradation. The degradation problem is solved by blending with polystyrene to reduce the processing temperature. We propose an alternative using triallylisocyanurate (TAIC). TAIC is a low viscosity liquid that can be cured by peroxide, e.g. α,α′‐bis(t‐butylperoxy‐m‐isopropyl)benzene (PBP), to provide a thermoset. The PPE/TAIC mixture was shown to have the upper critical solution temperature (UCST) type phase behavior. At the single‐phase regime above UCST and below the cure temperature (∼180°C for PBP), the mixture had a low viscosity, less viscous than a conventional thermoplastic such as PC and PP. That is, a nice window for injection molding was available, e.g., at 100°C to 160°C for a 50/50 blend. After injecting into a hot mold set at cure temperature, the blend cured in a short time (∼80% conversion in 5 min). Then the molded and partly cured material kept its shape and dimensions during post‐cure in a hot chamber at higher temperature (e.g. 250°C). Using transmission electron microscopy and dynamic mechanical analyses, it was shown that the cured blend had a bicontinuous two‐phase structure with periodic spacings of ∼30 nm, suggesting a structure formation via a spinodal decomposition driven by the increase in molecular weight of TAIC during cure. The cured material showed excellent flexural strength and high chemical resistance.
Control of L‐type calcium current during the action potential of guinea‐pig ventricular myocytes (1998)

1. During an action potential the L-type Ca2+ current (ICa,L) activates rapidly, then partially declines leading to a sustained inward current during the plateau phase. The reason for the sustained part of ICa,L has been investigated here. 2. In the present study the mechanisms controlling the ICa,L during an action potential were investigated quantitatively in isolated guinea-pig ventricular myocytes by whole-cell patch clamp. To measure the actual time courses of ICa,L and the corresponding L-type channel inactivation (fAP) during an action potential, action potential-clamp protocols combined with square pulses were applied. 3. Within the first 10 ms of the action potential the ICa,L rapidly inactivated by about 50 %; during the plateau phase inactivation proceeded to 95 %. Later, during repolarization, the L-type channels recovered up to 25 %. 4. The voltage-dependent component of inactivation during an action potential was determined from measurements of L-type current carried by monovalent cations. This component of inactivation proceeded rather slowly and contributed only a little to fAP. ICa,L during an action potential is thus mainly controlled by Ca2+-dependent inactivation. 5. In order to investigate the source of the Ca2+ controlling fAP, internal Ca2+ homeostasis was manipulated by the use of Ca2+ buffers (EGTA, BAPTA), by blocking Na+-Ca2+ exchange, or by blocking Ca2+ release from the sarcoplasmic reticulum (SR). Internal BAPTA markedly reduced the L-type channel inactivation during the entire action potential, whereas EGTA affected fAP only during the middle and late plateau phases. Inhibition of Na+-Ca2+ exchange markedly increased inactivation of L-type channels. Although blocking SR Ca2+ release decreased the fura-2-measured cytoplasmic Ca2+ concentration ([Ca2+]i) transient by about 90 %, it reduced L-type channel inactivation only during the initial 50 ms of the action potential. Thus, it is Ca2+ entering the cell through the L-type channels that controls the inactivation process for the majority of the action potential. Nevertheless, SR Ca2+-release contributes 40-50 % to L-type channel inactivation during the initial period of the action potential. However, the maximum extent of inactivation reached during the plateau is independent of Ca2+ released from the SR. 6. For the first time, the actual time course of L-type channel inactivation has been directly determined during an action potential under various defined [Ca2+]i conditions. Thereby, the relative contribution to ICa,L inactivation of voltage, Ca2+ entering through L-type channels, and Ca2+ being released from the SR could be directly demonstrated.
Handbook for Digital Signal Processing (1994)

From the Publisher:
Digital signal processing (DSP) revolutionized the electronics industry. Its flexibility, cost effectiveness, grammability, precision and broad range of applications - including applications in telecommunications, consumer electronics, radar, sonar, and more - have made it the methodology of choice over analog signal processing. Over the past two decades, advances in DSP technology have been so rapid and so massive that, until now, no single volume has offered comprehensive theoretical coverage of this fascinating field along with practical DSP applications. Handbook for Digital Signal Processing is the definitive source of detailed information on all important topics in modern digital signal processing. The only up-to-date handbook of its kind, it fills the needs of practicing engineers and designers of hardware, systems, and software. Written and edited by internationally known authorities on DSP, Handbook for Digital Signal Processing is supplemented with hundreds of informative tables and illustrations. For professional engineers, designers, and researchers in electronics and telecommunications, this book will be an indispensable reference, now and for years to come.
From Stochastic to Bit Stream Computing: Accurate Implementation of Arithmetic Circuits and Applications in Neural Networks (2018)

In this study, we propose a novel computing paradigm "Bit Stream Computing" that is constructed on the logic used in stochastic computing, but does not necessarily employ randomly or Binomially distributed bit streams as stochastic computing does. Any type of streams can be used either stochastic or deterministic. The proposed paradigm benefits from the area advantage of stochastic logic and the accuracy advantage of conventional binary logic. We implement accurate arithmetic multiplier and adder circuits, classified as asynchronous or synchronous; we also consider their suitability of processing successive streams. The proposed circuits are simulated both in gate level and in transistor level with AMS 0.35um CMOS technology to show the circuits' potential for practical use. We thoroughly compare the proposed adders and multipliers with their predecessors in the literature, individually and in a neural network application. Comparisons made in terms of area and accuracy clearly favor the proposed designs. We believe that this study opens up new horizons for computing that enables us to implement much smaller yet accurate arithmetic circuits compared to the conventional binary and stochastic ones.
Composition and Antifungal Activity on Soil-Borne Pathogens of the Essential Oil of <i>Salvia</i> <i>sclarea</i> from Greece (2002)

The hydrodistilled essential oils of the aerial parts of wild-growing Salvia sclarea originated from two localities in Greece were analyzed by GC-MS. Sixty-six compounds, representing 93.26-98.19% of the oils, were identified. Linalyl acetate (19.75-31.05%), linalool (18.46-30.43%), geranyl acetate (4.45-12.1%), and alpha-terpineol (5.08-7.56%) were the main components. The antifungal activity of the oil of one locality and of the main components, linalyl acetate and linalool, was evaluated in vitro against three soil-borne pathogens.
Entanglement Purification of Gaussian Continuous Variable Quantum States (2000)

We describe an entanglement purification protocol to generate maximally entangled states with high efficiencies from two-mode squeezed states or from mixed Gaussian continuous entangled states. The protocol relies on a local quantum nondemolition measurement of the total excitation number of several continuous variable entangled pairs. We propose an optical scheme to do this kind of measurement using cavity enhanced cross-Kerr interactions.
Hypertext and higher education: a reality check (1989)

This panel discussion will examine the extent to which today's hypermedia systems are actually used and usable in higher education instruction and research. The panel will seek to foster dialog between hypermedia systems developers, corpus authors, and faculty users. A series of questions will be addressed by the panel and audience, including: How are hypermedia corpuses actually used in classes? How well do today's systems meet the exploratory learning goals so often described as being at the heart of the hypermedia movement? What kinds of assignments make sense pedagogically? Are there system features which tend to discourage or prevent such uses?What are the difficulties involved in administering a course using hypertext? Are there unusual logistical problems? How does one monitor or manage the annotation and expansion of the corpus during the semester?Are today's hypermedia environments, tools, and practices proving to be useful for the faculty researcher? the student researcher? For faculty considering a hypertext to organize data, is periodic porting to new hardware and software a safe bet? or does the faculty member risk marooning two years of work inside an obsolete system?What are the prospects for published hypertext corpuses? What system features are likely to affect the economics of publication and distribution? What are the special problems in creating hypertext materials that can be used on other campuses and in other courses?
Enhancing the margin of selectivity of RPA 201772 in<i>Zea mays</i>with antidotes (1999)

The antidotes dichlormid, MON-4660, CGA-154281, R-29148, and MON-13900 were tested in the greenhouse to protect Zea mays L. (corn) against RPA 201772 injury. High rates of RPA 201772 injured four Z. mays hybrids > 30%. R-29148 and MON-13900 were the most effective of the five antidotes evaluated. R-29148 applied at rates ⩾ 45 g ha −1 provided excellent protection against RPA 201772 injury and also prevented injury to Z. mays from diketonitrile, the active metabolite of RPA 201772. In laboratory studies, R-29148 did not alter absorption of 14 C-RPA 201772 from soil; however, R-29148 significantly enhanced the rate of RPA 201772 metabolism and inactivation in Z. mays. The mixed function oxidase inhibitor piperonyl butoxide (PBO) increased RPA 201772 injury on all hybrids. These results demonstrate that Z. mays tolerance to RPA 201772 can be enhanced with the use of antidotes such as R-29148 and MON-13900, that R-29148 protects Z. mays from RPA 201772 and diketonitrile by the enhancement of metabolism, and that oxidative reactions may be involved in the metabolism of RPA 201772 in Z. mays.
Multiple Imaging and Multiple Fourier Transformation Using Microlens Arrays (1990)

A new type of coherent multiple imaging system using microlens arrays has been developed. The principles, features, basic functions and possible applications are also discussed with some experimental results which are implemented by using a planar microlens array fabricated by an ion exchange technique. An experimental result of the multichannel matched filtering has also been demonstrated.
Structural Insights into Fibrinogen Dynamics Using Amide Hydrogen/Deuterium Exchange Mass Spectrometry (2013)

We determined the amide hydrogen/deuterium exchange profile of native human fibrinogen under physiologic conditions. After optimization of the quench and proteolysis conditions, more than 1,200 peptides were identified by mass spectrometry, spanning more than 90% of the constituent Aα, Bβ, and γ chain amino acid sequences. The compact central and distal globular regions of fibrinogen were well protected from deuterium exchange, with the exception of the unfolded amino-terminal segments of the Aα and Bβ chains extending from the central region, and the short γ chain "tail" extending from each distal globular region. The triple-helical coiled-coil regions, which bridge the central region to each distal region, were also well protected with the exception of a moderately fast-exchanging area in the middle of each coiled-coil adjacent to the γ chain carbohydrate attachment site. These dynamic regions appear to provide flexibility to the fibrinogen molecule. The γ chain "out loop" contained within each coiled-coil also exchanged rapidly. The αC domain (Aα 392-610) exchanged rapidly, with the exception of a short segment sandwiched between a conserved disulfide linkage in the N-terminal αC subdomain. This latter finding is consistent with a mostly disordered structure for the αC domain in native fibrinogen. Analysis of the dysfibrinogen Bβ 235 Pro/Leu, which exhibits abnormal fibrin structure, revealed enhanced deuterium exchange surrounding the Pro/Leu substitution site as well as in the vicinity of the high affinity calcium binding site and the A knob polymerization pocket within the γC domain. The implication of these changes with respect to fibrin structure is discussed.
Partial purification and characterization of a macromolecule which enhances fluoride activation of adenylate cyclase. (1980)

Fluoride activation of adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] is significantly enhanced (2 to 5 times) by a protein factor isolated from rat brain. The fluoride-dependent adenylate cyclase stimulator (FCS) is nondialyzable, trypsin-labile, and stable at 90 degrees C for 10 min. FCS stimulates adenylate cyclase activity only in the presence of NaF (2-25 mM) and this effect is independent of added GTP, 5'-guanylylimidodiphosphate, or calcium. FCS has been purified roughly 3000-fold from a 12,000 X g supernatant fraction of rat brain homogenate. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and sucrose density gradient sedimentation suggest that FCS is a monomer with an apparent Mr of 59,000. Isoelectric focusing indicates FCS has a pI of 8.9. FCS from rat brain stimulates fluoride-activated adenylate cyclase from a variety of cell types, and FCS can also be isolated from rat liver. The effects of FCS are not reversed by washing membranes when the membranes and FCS are preincubated with NaF. The Km of adenylate cyclase for ATP and the fluoride concentration causing half-maximal activation are unchanged by FCS; however, FCS increases the Vmax by 2.5-fold. FCS may act to increase the catalytic efficiency of fluoride-activated complexes of the GTP-binding unit with adenylate cyclase or to enhance the formation of additional active complexes.
Introduction to the ACR-NEMA DICOM standard. (1992)

In 1982, the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) formed a committee to develop standards for the interconnection of digital imaging devices. Version 1.0 of the standard, published in 1985, specifies a hardware interface supporting point-to-point (not network) image transmission, a data dictionary (a set of rules for encoding information), and a set of commands to initiate transactions. Version 2.0, published in 1988, also addresses point-to-point image transmission and provides semantic rules by which messages (streams of bits representing information in transit from one device to another) are organized. Version 3.0, also referred to as DICOM (Digital Imaging and Communications in Medicine), will be finalized in 1992. The DICOM standard encourages open systems interconnection of imaging equipment over standard networks, while maintaining compatibility with earlier point-to-point connection standards. The DICOM standard conforms fully with the International Standards Organization reference model for network communications (ISORM), addresses the issue of conformance, and incorporates the concept of object-oriented design.