gebhart/patrepeval huggingface dataset:
T1-mapping in the heart: accuracy and precision (2014)

The longitudinal relaxation time constant (T1) of the myocardium is altered in various disease states due to increased water content or other changes to the local molecular environment. Changes in both native T1 and T1 following administration of gadolinium (Gd) based contrast agents are considered important biomarkers and multiple methods have been suggested for quantifying myocardial T1 in vivo. Characterization of the native T1 of myocardial tissue may be used to detect and assess various cardiomyopathies while measurement of T1 with extracellular Gd based contrast agents provides additional information about the extracellular volume (ECV) fraction. The latter is particularly valuable for more diffuse diseases that are more challenging to detect using conventional late gadolinium enhancement (LGE). Both T1 and ECV measures have been shown to have important prognostic significance. T1-mapping has the potential to detect and quantify diffuse fibrosis at an early stage provided that the measurements have adequate reproducibility. Inversion recovery methods such as MOLLI have excellent precision and are highly reproducible when using tightly controlled protocols. The MOLLI method is widely available and is relatively mature. The accuracy of inversion recovery techniques is affected significantly by magnetization transfer (MT). Despite this, the estimate of apparent T1 using inversion recovery is a sensitive measure, which has been demonstrated to be a useful tool in characterizing tissue and discriminating disease. Saturation recovery methods have the potential to provide a more accurate measurement of T1 that is less sensitive to MT as well as other factors. Saturation recovery techniques are, however, noisier and somewhat more artifact prone and have not demonstrated the same level of reproducibility at this point in time.This review article focuses on the technical aspects of key T1-mapping methods and imaging protocols and describes their limitations including the factors that influence their accuracy, precision, and reproducibility.
Online impedance matrix estimation of interconnected power systems (2009)

Grid impedance estimation is important in monitoring and protection of wide-area power systems. In this paper, a recursive least squares estimation algorithm with a forgetting factor is proposed to identify impedance matrix of electrical power grids. This new approach is based on synchronized phasor measurements and makes it possible to track changing parameters due to grid reconfiguration and load changes. The algorithm is tested on a power system using MATPOWER-generated data; the results show that the proposed estimation method is effective and with high accuracy.
Chemiosmotic energy conversion of the archaebacterial thermoacidophile Sulfolobus acidocaldarius: oxidative phosphorylation and the presence of an F0-related N,N'-dicyclohexylcarbodiimide-binding proteolipid (1989)

The energy-transducing mechanism of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius DSM 639 has been studied, addressing the question whether chemiosmotic proton gradients serve as an intermediate energy store driving an F0F1-analogous ATP synthase. At pH 3.5, respiring S. acidocaldarius cells developed an electrochemical potential of H+ ions, consisting mainly of a proton gradient and a small inside-negative membrane potential. The steady-state proton motive force of 140 to 160 mV was collapsed by protonophores, while N,N'-dicyclohexylcarbodiimide (DCCD) caused a hyperpolarization of the membrane, as expected for a reagent commonly used to inhibit the flux through proton channels of F0F1-type ATP synthases. Cellular ATP content was strongly related to the proton motive force generated by respiration and declined rapidly, either by uncoupling or by action of DCCD, which in turn induced a marked respiratory control effect. This observation strongly supports the operation of chemiosmotic ATP synthesis with H+ as the coupling ion. The inhibition of ATP synthesis by [14C]DCCD was correlated with covalent reactions with membrane proteins. The extraction of labeled membranes with organic solvents specifically yielded a readily aggregating proteolipid of 6 to 7 kilodaltons apparent molecular mass. Its amino acid composition revealed significant similarity to the proteolipid found in eubacteria, such as Escherichia coli, as an extremely hydrophobic constituent of the F0 proton channel. Moreover, the N-terminal amino acid sequence of the Sulfolobus proteolipid displays a high degree of homology to eubacterial sequences, as well as to one derived from nucleic acid sequencing of another Sulfolobus strain (K. Denda, J. Konishi, T. Oshima, T. Date, and M. Yoshida, J. Biol. Chem. 264:7119-7121, 1989). Despite certain structural similarities between eucaryotic vacuolar ATPases and the F1-analogous ATPase from Sulfolobus sp. described earlier, the results reported here promote the view that the archaebacterial ATP-synthesizing complex functionally belongs to the F0F1 class of ATPases. These may be considered as phylogenetically conserved catalysts of energy transduction present in all kingdoms of organisms.
Model-based invariants for 3D vision (2002)

A hierarchical representation of the 3D shape of objects that is invariant to affine and rigid 3D transformations is described. Model-based invariant functions of general 3D objects are defined and constructed using this representation. A linear algorithm for invariant structure from motion from a sequence of images is outlined. The model-based invariant functions are used as model-based object recognition operators, operating on raw image features. An efficient invariant implementation of alignment and geometric hashing is discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Adaptive multiuser receiver for shallow-water acoustic telemetry channels (1993)

Recent advances in coherent underwater communications technology are the backbone of an Acoustic Local Area Network (ALAN), which is designed for a real-time underwater telemetry with multiple sensors or unmanned underwater vehicles. In shallow-water areas ALAN is planned to cover 100–1000 km2 with nodes designed to communicate at 10 kbit/s at ranges of 3–4 nm. The communication protocol is optimized for a shallow-water acoustic environment, minimizing retransmission from finite-energy transceivers and taking into account time-variant link reliability and long propagation time between the nodes. One of the key elements of this protocol is a multiuser receiver capable of simultaneously demodulating signals coming from several asynchronous cochannel modems. Unlike spread-spectrum systems the narrow-band transmission is used. The propagation conditions in shallow water are severe due to the highly dynamic multipath structures and the adaptive multiuser receiver performs joint multiple-access cancellation, equalization, phase tracking, and bit timing recovery. It consists of fractionally spaced feedforward section, coupled digital phase-locked loops, and feedback sections, which utilize previous decisions both from the desired and the interfering user. The adaptive algorithm is the combination of the recursive least-squares algorithm for filter tap weights and a second-order phase update for the carrier recovery loop. Extensive testing has been carried out to confirm successful operation of the proposed receiver in a variety of propagation conditions using the experimental data provided by the Woods Hole Oceanographic Institution. The results indicate significant performance gain over the conventional receiver at the expense of a modest increase in complexity.
Neuromorphic pattern learning using HBM electronic synapse with excitatory and inhibitory plasticity (2015)

Bio-inspired neuromorphic system has become a popular domain of research because of its promising potential for low-power and robust fault-tolerant computing beyond the contemporary Von Neumann architecture [1]. The elementary building block of artificial neuromorphic systems is typically depicted as synaptic devices connecting between pre- and post-neuron units (Fig. 1), mimicking the morphology of synapses and neurons in biological systems, e.g. in the human brain [2]. Generally, the connecting strength of synapse is called synaptic weight, which is plastic and can be adjusted by applying an appropriate learning rule, such as the winner-take-all rule [2-3], through the fired signals of pre- and post-neurons. The strengthening (excitatory)/ weakening (inhibitory) processes of synaptic weight are referred as potentiation (P) and depression (D). Furthermore, the rapid development of resistive-switching random access memory (RRAM) recently has inspired significant interests on its memristive applications as high-density electronic synapses in artificial neuromorphic systems [4]. However, most RRAM devices reported in the literatures can only perform gradual SET or gradual RESET operations, and cannot be used as excitatory and inhibitory synapses simultaneously [3, 5-6]. In this paper, we report on a homogeneous barrier modulation (HBM) RRAM [7] that is capable of a simultaneous P and D (P+D) operational scheme. We perform a simulation of pattern learning algorithm based on the winner-take-all rule and experimental synaptic characteristics. The P+D scheme improves the contrast development of pattern learning and immunity to input noise as compared with the P-only scheme. The tolerance on the variations of synaptic cells is also examined with randomness at the initial resistance and P/D characteristics. This study suggests that the reported HBM synapse is a promising building block for future neuromorphic learning systems.
Parts renewal in continuous-time Monte Carlo reliability simulation (2003)

The simulation of complex multicomponent systems by Markov Monte Carlo methods has, to date, been limited to systems where system performance can be modeled by a time-inhomogeneous Markov process. This model is capable of including component dependencies as well as wear phenomenon represented by time-dependent failure rates. A discussion is presented of the formulation and implementation of a generalization of continuous-time Markov Monte Carlo simulation to include the renewal of system components. To demonstrate the use of this generalized Monte Carlo method, it is applied to a variety of problems which include the combined effects of wear and component dependency. Particular emphasis is given to the triple modular redundant system with reconfiguration of spares that is widely used in avionic electronics.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Adiabatic pulses (1997)

Adiabatic pulses are sometimes considered to be mysterious and exotic entities which are difficult to understand, complex to generate and impractical to implement. This work is an attempt to bring familiarity and to fulfill the preliminary needs of anyone interested in learning more about this subject. The response of magnetization to stimuli produced by adiabatic pulses is analyzed using vector representations in a frequency modulated rotating frame. The first section deals with basic principles of amplitude and frequency modulated pulses and a vector representation in a second rotating frame is used to explain how the adiabatic condition can be satisfied. The subsequent section explains the principles of offset independent adiabaticity. These principles are then used to design optimal functions for the amplitude, frequency, and magnetic field gradient modulations for adiabatic inversion pulses. The last section considers some practical aspects for those who want to develop methodologies involving adiabatic pulses.
Neuronal IP<sub>3</sub>3-Kinase is an F-actin–bundling Protein: Role in Dendritic Targeting and Regulation of Spine Morphology (2009)

The actin microstructure in dendritic spines is involved in synaptic plasticity. Inositol trisphosphate 3-kinase A (ITPKA) terminates Ins(1,4,5)P(3) signals emanating from spines and also binds filamentous actin (F-actin) through its amino terminal region (amino acids 1-66, N66). Here we investigated how ITPKA, independent of its kinase activity, regulates dendritic spine F-actin microstructure. We show that the N66 region of the protein mediates F-actin bundling. An N66 fusion protein bundled F-actin in vitro, and the bundling involved N66 dimerization. By mutagenesis we identified a point mutation in a predicted helical region that eliminated both F-actin binding and bundling, rendering the enzyme cytosolic. A fusion protein containing a minimal helical region (amino acids 9-52, N9-52) bound F-actin in vitro and in cells, but had lower affinity. In hippocampal neurons, GFP-tagged N66 expression was highly polarized, with targeting of the enzyme predominantly to spines. By contrast, N9-52-GFP expression occurred in actin-rich structures in dendrites and growth cones. Expression of N66-GFP tripled the length of dendritic protrusions, induced longer dendritic spine necks, and induced polarized actin motility in time-lapse assays. These results suggest that, in addition to its ability to regulate intracellular Ca(2+) via Ins(1,4,5)P(3) metabolism, ITPKA regulates structural plasticity.
A Spectrophotometric Study of the Schiff Reaction as Applied to the Quantitative Determination of Sulfur Dioxide (1960)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Spectrophotometric Study of the Schiff Reaction as Applied to the Quantitative Determination of Sulfur DioxideR. V. Nauman, P. W. West, Francois. Tron, and G. C. GaekeCite this: Anal. Chem. 1960, 32, 10, 1307–1311Publication Date (Print):September 1, 1960Publication History Published online1 May 2002Published inissue 1 September 1960https://pubs.acs.org/doi/10.1021/ac60166a023https://doi.org/10.1021/ac60166a023research-articleACS PublicationsRequest reuse permissionsArticle Views249Altmetric-Citations59LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Feasibility of Assessment of Promoter Methylation of the <i>CD44</i> Gene in Serum of Prostate Cancer Patients (2001)

In the serum of CAP patients, assessment of the methylation status of CpG islands in the promoter region of the CD44 gene is feasible using methylation-specific PCR. However, because of physiologic promoter methylation in normal tissues, including the colorectal mucosa, assessment of methylation of tumor-derived DNA in the serum of cancer patients lacks tissue specificity and seems not to be applicable in clinical settings.
Prediction of user app usage behavior from geo-spatial data (2016)

In the era of mobile Internet, a vast amount of geo-spatial data allows us to gain further insights into human activities, which is critical for Internet Services Providers (ISP) to provide better personalized services. With the pervasiveness of mobile Internet, much evidence show that human mobility has heavy impact on app usage behavior. In this paper, we propose a method based on machine learning to predict users' app usage behavior using several features of human mobility extracted from geo-spatial data in mobile Internet traces. The core idea of our method is selecting a set of mobility attributes (e.g. location, travel pattern, and mobility indicators) that have large impact on app usage behavior and inputting them into a classification model. We evaluate our method using real-world network traffic collected by our self-developed high-speed Traffic Monitoring System (TMS). Our prediction method achieves 90.3% accuracy in our experiment, which verifies the strong correlation between human mobility and app usage behavior. Our experimental results uncover a big potential of geo-spatial data extracted from mobile Internet.
Electric Load Forecasting (2007)

This article illustrates the application of a nonlinear system identification technique to the problem of STLF. Five NARX models are estimated using fixed-size LS-SVM, and two of the models are later modified into AR-NARX structures following the exploration of the residuals. The forecasting performance, assessed for different load series, is satisfactory. The MSE levels on the test data are below 3% in most cases. The models estimated with fixed-size LS-SVM give better results than a linear model estimated with the same variables and also better than a standard LS-SVM in dual space estimated using only the last 1000 data points. Furthermore, the good performance of the fixed-size LS-SVM is obtained based on a subset of M = 1000 initial support vectors, representing a small fraction of the available sample. Further research on a more dedicated definition of the initial input variables (for example, incorporation of external variables to reflect industrial activity, use of explicit seasonal information) might lead to further improvements and the extension toward other types of load series.
Circuit-coupled FEM analysis of the electric-field type intra-body communication channel (2009)

The electric-field (EF) intra-body communication (IBC) is a promising data transmission method for high-speed low-power biomedical sensors. A good model of the EF-IBC channel is needed for better understanding the signal propagation principle and more efficient IBC transceiver design. Although various effective models have been developed for the waveguide IBC channel, the EF-IBC channel has only been modeled by empirical distributed RC network. In this paper, a circuit-coupled finite-element-method (FEM) model is established to analyze the EF-IBC channel. A multi-layer FEM model is developed for the human forearm. The parasitic effects of the probe PCBs and the return path are modeled as circuit elements. The circuit-coupled FEM model is simulated in ANSYS. Simulation results show that the model agrees well with the EF-IBC measurements. The circuit-coupled FEM model provides useful insights into the EF-IBC mechanism.
Immunization with H1, HASPB1 and MML Leishmania proteins in a vaccine trial against experimental canine leishmaniasis (2007)

The protective capabilities of three Leishmania recombinant proteins - histone 1 (H1) and hydrophilic acylated surface protein B1 (HASPB1) immunized singly, or together as a protein cocktail vaccine with Montanide, and the polyprotein MML immunized with MPL-SE adjuvant - were assessed in beagle dogs. Clinical examination of the dogs was carried out periodically under blinded conditions and the condition of the dogs defined as asymptomatic or symptomatic. At the end of the trial, we were able to confirm that following infection with L. infantum promastigotes, five out of eight dogs immunized with H1 Montanide, and four out of eight dogs immunized with either the combination of HASPB1 with Montanide or the combination of H1+HASPB1 with Montanidetrade mark, remained free of clinical signs, compared with two out of seven dogs immunized with the polyprotein MML and adjuvant MPL-SE, and two out of eight dogs in the control group. The results demonstrate that HASPB1 and H1 antigens in combination with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions.
Zirconocene‐catalysed propene polymerisation: kinetics, mechanism, and the role of the anion (2004)

Abstract The olefin polymerisation activity of metallocene catalysts strongly depends on the counteranion provided by the activator system. The relative activities of a number of new diborate anions [Z(BAr 3 ) 2 ] − have been quantified (Z = CN, NH 2 , N(CN) 2 ; Ar = C 6 F 5 or o ‐C 6 F 4 C 6 F 5 ). The kinetic parameters for the initiation, propagation and termination steps of propene polymerisations catalysed by (SBI)ZrCl 2 have been determined using quenched‐flow kinetic and batch techniques [SBI = rac ‐Me 2 Si(1‐Ind) 2 ]. Comparison of two activator systems, (i) CPh 3 [B(C 6 F 5 ) 4 ] / triisobutylaluminium (TIBA) and (ii) methylaluminoxane (MAO) shows, surprisingly, that the concentration of species actively involved in chain growth at any one time is comparable for both systems, although the MAO‐activated catalyst is about 20 times less active than the borate system. It is concluded that the counteranion remains sufficiently strongly bound to the metal centre throughout the chain growth sequence to modulate the energetics of monomer insertion. A model suggesting that the monomer binding follows an associative interchange ( I a ) mechanism is proposed.
Collision detection and untangling for surgical robotic manipulators (2009)

Our system helps alleviate the collision problem by reducing the time in collision.
The central questions in pain perception may be peripheral (1998)

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
Evaluating the power of flexible packet processing for network resource allocation (2017)

Recent hardware switch architectures make it feasible to perform flexible packet processing inside the network. This allows operators to configure switches to parse and process custom packet headers using flexible match+action tables in order to exercise control over how packets are processed and routed. However, flexible switches have limited state, support limited types of operations, and limit per-packet computation in order to be able to operate at line rate.

Our work addresses these limitations by providing a set of general building blocks that mask these limitations using approximation techniques and thereby enabling the implementation of realistic network protocols. In particular, we use these building blocks to tackle the network resource allocation problem within datacenters and realize approximate variants of congestion control and load balancing protocols, such as XCP, RCP, and CONGA, that require explicit support from the network. Our evaluations show that these approximations are accurate and that they do not exceed the hardware resource limits associated with these flexible switches. We demonstrate their feasibility by implementing RCP with the production Cavium CNX880xx switch. This implementation provides significantly faster and lower-variance flow completion times compared with TCP.