gebhart/patrepeval huggingface dataset:
Multivariate Functional Clustering for the Morphological Analysis of Electrocardiograph Curves (2012)

Summary Cardiovascular ischaemic diseases are one of the main causes of death all over the world. In this class of pathologies, a quick diagnosis is essential for a good prognosis in reperfusive treatment. In particular, an automatic classification procedure based on statistical analysis of teletransmitted electrocardiograph (‘ECG’) traces would be very helpful for an early diagnosis. This work presents an analysis of ECG traces, either physiological or pathological, of patients whose 12-lead prehospital ECG has been sent to the 118 Dispatch Center in Milan by life-support personnel. The statistical analysis starts with a preprocessing step, where functional data are reconstructed from noisy observations and biological variability is removed by a non-linear registration procedure. Then, a multivariate functional k-means clustering procedure is carried out on reconstructed and registered ECGs and their first derivatives. Hence, a new semi-automatic diagnostic procedure, based solely on the ECG morphology, is proposed to classify ECG traces; finally, the performance of this classification method is evaluated.
Low-Dimensional Arrangement of SiO<sub>2</sub> Particles (2002)

Novel processes to realize low-dimensional arrangement of SiO2 particles were proposed. Particle wires and a pattern of the close-packed particle monolayer were fabricated in the solution at room temperature. SAMs (self-assembled monolayers) were formed on Si substrates and modified to be suitable for templates of precise arrangement. Particles were arranged precisely in the desired positions in the solution using well-controlled electrostatic interactions and chemical bond formation between particles and substrates.
Role of electrostatic interactions in the binding of fluorescein by anti-fluorescein antibody 4-4-20 (1993)

Anti-fluorescein antibodies are excellent model systems for studying the biochemical basis of molecular recognition because a prodigious amount of both physico-chemical and structural information is available for these antibodies. Furthermore, recombinant single-chain antibodies have been produced for several anti-fluorescein antibodies, and site-specific mutagenesis studies have defined the energetic contributions of a number of key active-site residues. In previous studies, we determined the three-dimensional structure of an antigen-binding fragment of a high-affinity anti-fluorescein antibody (4-4-20) in complex with fluorescein. These studies showed that fluorescein binds tightly in an aromatic slot and participates in a network of electrostatic interactions. In this report, we examine the role of electrostatic interactions in the 4-4-20 antigen-combining site by observing the effects of pH on the fluorescence of fluorescein and antigen-binding affinity. These studies showed that the salt link between fluorescein and Arg-L34 in 4-4-20 probably accounts for about -1.5 kcal/mol-1 of the observed free energy of interaction. Furthermore, at pH 10 and higher, the affinity decreases by more than 100-fold (delta delta G degrees approximately equal to 3 kcal mol-1). We attributed this decrease to the ionization of Tyr-L32, which probably disrupts a hydrogen bond between tyrosine's hydroxyl group and fluorescein's phenylcarboxylate group. The fluorescence lifetime of the 4-4-20/fluorescein complex was determined at both pH 8 and pH 10.6. Only one lifetime component (0.38 ns) was observed at pH 8, while two components (0.3 and 3.4 ns) were observed at pH 10.6.(ABSTRACT TRUNCATED AT 250 WORDS)
Application of single-transistor smart-power IC for fluorescent lamp ballast (1999)

A single-chip class-E converter was developed for fluorescent lamp ballasts. The IC is based on SIMOX technology and includes a 1200 V DMOS transistor and a low voltage control part. It is applicable for compact and other fluorescent lamps up to 15 Watts. The functionality of the chip includes preheating, self-protection, over- and undervoltage protection, temperature-protection, low temperature detection for increased preheating time, dimming or power control, by changing the supply voltage up to 50%, and an input-voltage independent power control of the lamp. The solution offers possibilities for applications with a reduced input charging capacitor for lower line voltages, or for bootstrap circuitry to achieve a high power factor up to 0.9, universal input, voltage- and capacity-reduced charging capacitors, and inrush-current limiting. A smart-power IC with a low voltage control part, a single 1200 V DMOS transistor, and only 5 pins, gives the possibility of low cost solutions in the future, e.g. with new power technologies like the Cool-Mos technology.
Peer Conversations for e-Learning in the Grid (2005)

We take the view of ‘learning as a conversational process’, and argue that this can be extended to include the notions of peer-group interactions among students, tutors, and even artificial agents. This in turn lends itself to an approach to distributed conversation which builds upon modern Instant Messaging tools, and extends such tools to include what we call enhanced presence: a way of monitoring the availability of (and interacting with) fellow students and tutors at a distance. We describe a scenario being developed in the recently-started European Learning Grid Infrastructure ‘ELeGI’ project, deploying our own BuddySpace tools, and describe the novel contributions that this approach can bring to e-learning.
A Precision Sample and Hold Circuit with Subnanosecond Switching (1964)

This paper is concerned with the analysis, design, and physical embodiment of a sample and hold circuit for use in a high speed, high performance (9-digit) PCM system. A precision bilateral gate employing gallium arsenide diodes is at the heart of the circuit. Subnanosecond recovery time, low capacitance (<1 pf), and large forward conductance characterize the gate diodes. Switching of the gate is accomplished at about a 12 Mc/sec sampling rate by a fast driver circuit. To prevent excess current drain from the signal source a constant current source is switched in by the driver to dominate charging of the holding capacitor when the difference between the input and held voltages is large. As the input and output signals approach correspondence, RC charging from the signal source predominates. The approximate dual mode operation of the gate permits a piecewise linear analysis applicable to transmission and switching performance. An equivalent block diagram for the sample and hold circuit is developed that contains linear filters and zero memory nonlinear networks. Nonlinear distortion is evaluated for a bandlimited white noise probe. To approach an over-all system performance limited largely by quantizing noise, the sample and hold circuit must be designed to introduce minimum signal impairment. This necessitates switching in less than one nanosecond and maintenance of the held waveform flat to within about one part in 5,000. Achievement of these difficult requirements is assured through careful analysis, design, and embodiment and has been verified by experiment.
Turbulent flux calculation in the polar stable boundary layer: Multiresolution flux decomposition and wavelet analysis (2007)

Airborne measurements in the Arctic stable boundary layer were performed using the helicopter‐borne turbulence measurement system Helipod. The observations were carried out during the ARK‐XII summer expedition of the research icebreaker Polarstern in the Arctic ocean. The boundary layer over closed sea ice exhibited mainly weakly stable stratification. Only flights in continuous turbulence were chosen for the analysis. The measurements of sensible heat flux H and latent heat flux λ E were made 200 km away from land to reduce the influence of any captured mesoscale flux. Nevertheless, the analysis of multiresolution (MR) cospectra yield some small mesoscale flux contribution, visible at the larger timescales. A MR gap timescale τ gap was defined to separate the turbulent flux from the mesoscale flux and used for the recalculation of the turbulent fluxes after high‐pass filtering. This procedure also reduced the statistical error of the fluxes significantly. For comparison, wavelet transformations were performed that led to wavelet gap scales of the fluxes in good agreement with the MR gap scale. Additionally, the wavelet covariance gave a good representation of the homogeneity of the kinematic heat flux w ′θ′ and the kinematic moisture flux w ′ m ′ in time.
Functional Relevance of Amino Acid Residues Involved in Interactions with Ordered Nucleic Acid in a Spherical Virus (2005)

In the spherical virion of the parvovirus minute virus of mice, several amino acid side chains of the capsid were previously found to be involved in interactions with the viral single-stranded DNA molecule. We have individually truncated by mutation to alanine many (ten) of these side chains and analyzed the effects on capsid assembly, stability and conformation, viral DNA encapsidation, and virion infectivity. Mutation of residues Tyr-270, Asp-273, or Asp-474 led to a drastic reduction in infectivity. Mutant Y270A was defective in capsid assembly; mutant D273A formed stable capsids, but it was essentially unable to encapsidate the viral DNA or to externalize the N terminus of the capsid protein VP2, a connected conformational event. Mutation of residues Asp-58, Trp-60, Asn-183, Thr-267, or Lys-471 led to a moderate reduction in infectivity. None of these mutations had an effect on capsid assembly or stability, or on the DNA encapsidation process. However, those five mutant virions were substantially less stable than the parental virion in thermal inactivation assays. The results with this model spherical virus indicate that several capsid residues that are found to be involved in polar interactions or multiple hydrophobic contacts with the viral DNA molecule contribute to preserving the active conformation of the infectious viral particle. Their effect appears to be mediated by the non-covalent interactions they establish with the viral DNA. In addition, at least one acidic residue at each DNA-binding region is needed for DNA packaging.
Vibrational relaxation in simple fluids: Comparison of theory and simulation (1993)

General theoretical expressions for the dephasing and energy relaxation times of a stiff oscillator in simple fluids are derived from the GLE and a critical discussion of the dynamic processes in these systems is given. In addition new methodological aspects of stochastic and full molecular dynamics simulations are discussed. The new reversible integrator based on the Trotter factorization of the classical propagator is used to directly simulate the vibrational energy and phase relaxation of a stiff classical oscillator dissolved in a Lennard-Jones bath. We compare the ‘‘real’’ relaxation from full MD simulations with that predicted by Kubo theory and by the generalized Langevin equation (GLE) with memory friction determined from the full molecular dynamics. It is found that the GLE gives very good agreement with MD for the vibrational energy relaxation, even for nonlinear oscillators far from equilibrium. The dephasing relaxation is also well approximated by the GLE.
Quiet Clean Short-haul Experimental Engine (QCSEE) under-the-wing engine composite fan blade design report (1977)

A total of 38 quiet clean short haul experimental engine under the wing composite fan blades were manufactured for various component tests, process and tooling, checkout, and use in the QCSEE UTW engine. The component tests included frequency characterization, strain distribution, bench fatigue, platform static load, whirligig high cycle fatigue, whirligig low cycle fatigue, whirligig strain distribution, and whirligig over-speed. All tests were successfully completed. All blades planned for use in the engine were subjected to and passed a whirligig proof spin test.
Intestinal organoids model human responses to infection by commensal and Shiga toxin producing Escherichia coli (2017)

Infection with Shiga toxin (Stx) producing Escherichia coli O157:H7 can cause the potentially fatal complication hemolytic uremic syndrome, and currently only supportive therapy is available. Lack of suitable animal models has hindered study of this disease. Induced human intestinal organoids (iHIOs), generated by in vitro differentiation of pluripotent stem cells, represent differentiated human intestinal tissue. We show that iHIOs with addition of human neutrophils can model E. coli intestinal infection and innate cellular responses. Commensal and O157:H7 introduced into the iHIO lumen replicated rapidly achieving high numbers. Commensal E. coli did not cause damage, and were completely contained within the lumen, suggesting defenses, such as mucus production, can constrain non-pathogenic strains. Some O157:H7 initially co-localized with cellular actin. Loss of actin and epithelial integrity was observed after 4 hours. O157:H7 grew as filaments, consistent with activation of the bacterial SOS stress response. SOS is induced by reactive oxygen species (ROS), and O157:H7 infection increased ROS production. Transcriptional profiling (RNAseq) demonstrated that both commensal and O157:H7 upregulated genes associated with gastrointestinal maturation, while infection with O157:H7 upregulated inflammatory responses, including interleukin 8 (IL-8). IL-8 is associated with neutrophil recruitment, and infection with O157:H7 resulted in recruitment of human neutrophils into the iHIO tissue.
The Pathways of Thiamine Biosynthesis (1968)

Certain thiamine-requiring auxotrophs of Neurospora crassa synthesize compounds related to the pyrimidine moiety of thiamine. The accumulation of these compounds was inhibited by thiamine and oxythiamine and stimulated by Zn++, Fe+++, and the purine analogues, 4-aminopyrazolo-pyrimidine and 2,6-diaminopurine. Bioautography revealed the presence in this medium of four compounds capable of serving as precursors of the pyrimidine moiety for the test organism, Enterobacter aerogenes strain PD1, and of several other compounds capable of serving as precursors of the thiazole moiety for an Escherichia coli thiazoleless strain.
Effect of inflammatory cytokines on human endothelial cell proliferation (1990)

Neovascularization, a common occurrence in chronic inflammatory lesions, requires endothelial cell (EC) proliferation. Because this form of inflammation is often mediated by immunologically generated cytokines, the effects of such cytokines on human umbilical vein EC proliferation in vitro were investigated. Low concentrations of recombinant interferon gamma (rIFN-gamma) (10-100 U/ml), but not a higher concentration (1,000 U/ml), enhanced both basal and endothelial cell growth factor (ECGF)-stimulated EC proliferation. Recombinant interleukin 1 (rIL-1) and recombinant tumor necrosis factor-alpha (rTNF) had minor effects on basal EC proliferation, but significant inhibition was observed in the presence of ECGF. A combination of rIFN-gamma and rTNF induced marked suppression of EC proliferation, which appeared to be due to a cytotoxic effect on the EC, as demonstrated by 51Cr release. In contrast, the combination of rIFN-gamma and rIL-1 had only an additive effect on EC proliferation, with no evidence of cytotoxicity. These results suggest that cytokines have important regulatory roles in local vascular proliferation. These effects varied not only with the individual cytokine, but also with the combination of cytokines used. The most striking effects were 1) the stimulation of proliferation by IFN-gamma at a low concentration and 2) the inhibition by both rIL-1 and rTNF of ECGF-stimulated proliferation.
The potential beneficial effect of nicardipine in a rat model of transient forebrain ischemia (1987)

In a rat 3-day survival model of 10-minute four-vessel occlusion, halothane anesthesia was used to attenuate the ictal blood pressure elevation of the cerebral ischemic response and thereby maintain an isoelectric EEG. Selectively vulnerable regions of the brain were protected by preischemia plus postischemia maintenance treatment with the calcium entry blocker nicardipine. Compared with untreated animals, repeated doses at 500 micrograms/kg IP were markedly more effective than doses of 50 micrograms/kg. Ongoing studies demonstrate a neurocytoprotective action of nicardipine when deferred treatment is given postischemia.
Alveolar pressure inhomogeneity during low-frequency oscillation of excised canine lobes (1990)

To quantify the inhomogeneity of alveolar pressures (PA) during cyclic changes in lung volume similar to those present during spontaneous breathing, inhomogeneity of PA was measured with an alveolar capsule technique in six excised canine lungs. The lungs were ventilated by a quasi-sinusoidal pump with a constant end-expiratory lung volume and tidal volumes of 10, 20, and 40% of vital capacity at breathing frequencies ranging from 5 to 45 breaths/min. Inhomogeneity of PA was quantified as the sample standard deviation of pressures measured in three capsules. A component of inhomogeneity in phase with flow and a smaller component out of phase with flow were present. The in-phase component increased approximately linearly with flow. The ratio of inhomogeneity to flow was smaller at large tidal volumes and, at the two higher tidal volumes studied, the ratio was greater during inspiration than during expiration. If these data are interpreted in terms of a simple circuit model, this degree of inhomogeneity implies an approximately twofold variation in regional time constants. Despite these considerable differences in time constants, the absolute amount of inhomogeneity as defined by the sample standard deviation of the three PA's was small (maximum 0.57 +/- 0.32 cmH2O at the highest breathing frequency and tidal volume) because airway resistance in the canine lung was small.
Overexpression of a Mutant Basic Helix-Loop-Helix Protein HFR1, HFR1-ΔN105, Activates a Branch Pathway of Light Signaling in Arabidopsis (2003)

The HFR1, a basic helix-loop-helix protein, is required for a subset of phytochrome A-mediated photoresponses in Arabidopsis. Here, we show that overexpression of the HFR1-deltaN105 mutant, which lacks the N-terminal 105 amino acids, confers exaggerated photoresponses even in darkness. Physiological analysis implied that overexpression of HFR1-deltaN105 activated constitutively a branch pathway of light signaling that mediates a subset of photomorphogenic responses, including germination, de-etiolation, gravitropic hypocotyl growth, blocking of greening, and expression of some light-regulated genes such as CAB, DRT112, PSAE, PSBL, PORA, and XTR7, without affecting the light-responsiveness of anthocyanin accumulation and expression of other light-regulated genes such as CHS and PSBS. Although the end-of-day far-red light response and petiole elongation were suppressed in the HFR1-deltaN105-overexpressing plants, flowering time was not affected by HFR1-deltaN105. In addition, the HFR1-deltaN105-overexpressing plants showed hypersensitive photoresponses in the inhibition of hypocotyl elongation, dependently on phytochrome A, FHY1, and FHY3 under FR light or phyB under R light, respectively. Moreover, our double mutant analysis suggested that the hypersensitive photoresponse is due to functional cooperation between HFR1-deltaN105 and other light-signaling components including HY5, a basic leucine zipper protein. Taken together, our results of gain-of-function approach with HFR1-deltaN105 suggest the existence of a complex and important basic helix-loop-helix protein-mediated transcriptional network controlling a branch pathway of light signaling and provide a useful framework for further genetic dissection of light-signaling network in Arabidopsis.
Determination of molecular weights by fluctuation spectroscopy: application to DNA. (1976)

A method for determining molecular weights of macromolecules by measuring spontaneous concentration fluctuations is described. The method is absolute, rapid, and requires no shearing forces on the molecules. We have applied this technique to the determination of molecular weight of DNA molecules. The molecular weight values obtained for T2 phage DNA (1.14 X 10(8)) and replicating Escherichia coli DNA (3.9 X 10(9)) agree with previous results. By monitoring individual molecules, an estimate of the molecular weight of nuclei and individual chromosomal DNA molecules of Drosophila melanogaster was obtained.
Differential expression of Galectin-1 and Galectin-3 during first trimester human embryogenesis (1997)

Development of complex organisms requires specific temporospatial differentiation and expression of the correct phenotype through activation of a variety of genes. Galectins are mammalian lectins able to interact with various extracellular matrix glycoconjugates and have been implicated in several biological events including cell attachment, differentiation, apoptosis, embryogenesis, and cancer invasion and metastasis. In this study, we have examined the expression of galectin-1 and galectin-3 during human first trimester embryogenesis using immunohistochemistry and Western blotting. Variable amounts of galectin-1 and galectin-3 were detected in all tissue protein extracts. Galectin-1 expression was demonstrated in the connective tissue and derived tissues such as smooth and striated muscle cells, and in some epithelia, such as in the basal layers of the skin after 14 weeks and in the epithelial cells of the gonads. Galectin-3 was detected mainly in epithelia, such as the skin, epithelial lining of the digestive and respiratory tract, and urothelium and excretory tubes of the kidney, but also in the myocardial cells, in the peripheral and preossifying hypertrophic chondrocytes, and in the notochord and in the liver. Our study constitutes the first demonstration of galectin-1 and galectin-3 during human embryogenesis. The differential expression of these two lectins suggests that they could participate in the complex processes of tissue differentiation.
Minimal BH3 Peptides Promote Cell Death by Antagonizing Anti-apoptotic Proteins (2003)

The pro-apoptotic "BH3 domain-only" proteins of the Bcl-2 family (e.g. Bid and Bad) transduce multiple death signals to the mitochondrion. They interact with the anti-apoptotic Bcl-2 family members and induce apoptosis by a mechanism that requires the presence of at least one of the multidomain pro-apoptotic proteins Bax or Bak. Although the BH3 domain of Bid can promote the pro-apoptotic assembly and function of Bax/Bak by itself, other BH3 domains do not function as such. The latter point raises the question of whether, and how, these BH3 domains induce apoptosis. We show here that a peptide comprising the minimal BH3 domain from Bax induces apoptosis but is unable to stimulate the apoptotic activity of microinjected recombinant Bax. This relies on the inability of the peptide to directly induce Bax translocation to mitochondria or a change in its conformation. This peptide nevertheless interferes with Bax/Bcl-xL interactions in vitro and stimulates the apoptotic activity of Bax when combined with Bcl-xL. Similarly, a peptide derived from the BH3 domain of Bad stimulates Bax activity only in the presence of Bcl-xL. Thus, BH3 domains do not necessarily activate multidomain pro-apoptotic proteins directly but promote apoptosis by releasing active multidomain pro-apoptotic proteins from their anti-apoptotic counterparts.
Building with Blogs (2003)

Is it a diary? A links page? Or more? The king of blogs and the author of new blog-ranking software outline your choices.