gebhart/patrepeval huggingface dataset:
On the cramer-rao bound for carrier frequency estimation in the presence of phase noise (2007)

We consider the carrier frequency offset estimation in a digital burst-mode satellite transmission affected by phase noise. The corresponding Cramer-Rao lower bound is analyzed for linear modulations under a Wiener phase noise model and in the hypothesis of knowledge of the transmitted data. Even if we resort to a Monte Carlo average, from a computational point of view the evaluation of the Cramer-Rao bound is very hard. We introduce a simple but very accurate approximation that allows to carry out this task in a very easy way. As it will be shown, the presence of the phase noise produces a remarkable performance degradation of. the frequency estimation accuracy. In addition, we provide asymptotic expressions of the Cramer-Rao bound, from which the effect of the phase noise and the dependence on the system parameters of the frequency offset estimation accuracy clearly result. Finally, as a by-product of our derivations and approximations, we derive a couple of estimators specifically tailored for the phase noise channel that will be compared with the classical Rife and Boorstyn algorithm, gaining in this way some important hints on the estimators to be used in this scenario
Three-dimensional in vivo imaging by spectral OCT (2004)

Speed improvement in the Spectral Optical Coherence Tomography (SOCT) technique allows to obtain three-dimensional images in vivo in time that does not cause discomfort to a patient. The device allows high speed imaging at 64 μs per line (15,000 A-scans/s) with less than 200 μW light power on the surface of the eye. Three alternative methods of 3-D presentations are demonstrated for images of a pupil and human skin in vivo.
Do we want more cancer patients on clinical trials If so, what are the barriers to greater accrual (2008)

It is often stated that only a small proportion of adult cancer patients participate in clinical trials. This is said to be a bad thing, with calls for more trials to include more patients. Here I argue that whether or not greater accrual to clinical trials would be a good thing depends on the trials we conduct. The vast majority of clinical trials in cancer are currently early phase trials, and most do not lead to further studies even if they have encouraging results. The key metric is thus not the number of patients on clinical trials, but the number on the sort of large, randomized, Phase III trials that can be used as a basis for clinical decisions. I also address two important barriers to greater clinical trial participation. The first barrier is financial: clinical research has long been the poor cousin of basic research, with perhaps no more than a nickel in the cancer research dollar going to clinical research. The second barrier is regulatory: clinical research has become so overburdened by regulation that it takes years to initiate a trial, and dedicated staff just to deal with the paperwork once the trial starts. This not only adds significantly to the costs of clinical research, but scares many young investigators away. It has been estimated that nearly half of all US-sponsored trials are being conducted abroad, and it is plausible that excessive regulation is at least partly responsible. That statistic should serve as a wake-up call to the US clinical research community to implement the recommendations of the now decade-old report of National Cancer Institute Clinical Trials Program Review Group, which largely center around simplifying trials and streamlining trial procedures.
Discrepancy between in vitro and in vivo passaged U-937 human leukemic cells: tumorigenicity and sensitivity to differentiating drugs. (1992)

The treatment of nude mice bearing tumors of transplanted human leukemic cells with drugs known to induce differentiation of the same leukemic cells in vitro does not always affect tumor yield, tumor cell differentiation or nude mice survival. We have transplanted human monoblastic leukemic cells of the U-937 cell line into newborn Swiss nu/nu mice. Priming with cyclophosphamide, followed by subcutaneous injections of at least 10 x 10(6) cells allowed us to obtain solid tumors. The cytology, HLA phenotype and in vitro proliferation characteristics of the U-937 tumor cells were conserved. However, these tumor cells were more tumorigenic when reinjected into nude mice and showed a modified response to differentiation induction. A decreased capacity to differentiate with retinoic acid (RA) and a resistance to 1-beta-D arabinofuranosyl cytosine (Ara-C) and 1-25 dihydroxy vitamin D3 (1-25 (OH)2 D3) were noted in three tumor cell lines tested. With regard to the latter, the resistance was not due to a modification of the number of cell receptors. The study shows that though in vivo transplantation of human leukemic cells in nude mice may lead to a selection of resistant cells, systematic checking of in vitro differentiation characteristics of the tumor cells permits the nude mouse model to be maintained for the in vivo screening of new differentiating agents.
The accuracy of fetal pulse oximetry in the second stage of labour. (1991)

The aim of this study is to assess the accuracy of fetal monitoring with pulse oximetry at delivery. The pulse oximetry reading from the fetus at delivery was compared to fetal condition at birth. There is poor correlation between fetal scalp oximetry readings at delivery and fetal condition (Apgar scores), umbilical venous or arterial blood gas analysis or pH. Although there are good theoretical reasons why the correlation should not be perfect, the wide deviation from expected values suggest that readings taken during delivery are particularly prone to errors. Examination of the unprocessed photodetector signal during the second stage of labour reveals considerable movement interference. The signal may also be affected by congestion and transmitted venous pulsation in the scalp as the head crowns. The current generation of reflectance pulse oximeters can predict fetal hypoxemia during labour but a single reading during delivery is subject to too much movement interference to produce useful data.
The Clonal Activity of Marked Hematopoietic Stem Cells (2006)

This chapter contains sections titled: Introduction Characterization of In-vivo Clonal Activity of HSCs by Genetic Marking Retroviral Integration Site Analysis Clonality Analysis in Animal Model and Human Gene Therapy Trials Clonal Activity of Marked HSCs in Mouse Models Clonal Activity of Marked HSCs in Non-Human Primate Models Clonal Activity of Marked HSCs in Human Gene Therapy Clinical Trials Clonality Analysis in ADA-SCID Gene Therapy Clinical Trial Clonality Analysis in SCID-X1 Gene Therapy Clinical Trial LMO2 Insertion Leads to Malignant Expansion of Marked HSCs Interaction of Retroviral Integration Site and Transgene Expression with Clonal Activity of the Respective HSC Impact of Transgene Expression on Clonal Activity of Marked HSCs Clinical Interventions Affect the Clonal Activity of Marked HSCs Perspectives
Physical characteristics of TTV03, a new high spatial resolution time-of-flight positron tomograph (1990)

TTV03, a novel high-spatial-resolution TOF-PET (time-of-flight positron emission tomography) system, is presented. The machine consists of four 89-cm-diameter rings made of 7-mm-wide, 18-mm-high, 45-mm-deep BaF/sub 2/ crystals (324 per ring) individually coupled to 11-mm-diameter phototubes. The transaxial resolution (full width at half maximum or FWHM) in the reconstructed image is 5.7 mm at center, 5.7 mm (tangential), and 6.5 mm (radial) at 10 cm. The axial resolution is 8.8 mm (direct plane) and 6.7 mm (crossplane) at center, and 10.3 mm (direct) and 11.2 mm (cross) at 10 cm from center. With a 150-keV threshold, the TOF resolution is 750 ps (FWHM), and, with a 4.18-ns coincidence window, the sensitivity (true evts/s per mu Ci/cm/sup 3/) is 9800 (direct plane) and 14300 (crossplane). At 1 mu Ci/cm/sup 3/, the ratio of random events to true events is .20 for the total and .03 per image element, and the scatter fraction is 22%. Dead time losses are 8.3% at 2.5 mu Ci/cm/sup 3/ (four rings), but the tomograph can handle activities over 50 mu Ci/cm/sup 3/ in small regions with negligible losses. These characteristics make TTV03 particularly suitable for dynamic brain and heart H/sub 2//sup 15/ bolus studies.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Effect of Weed on Physiology and Nutrient of Corn under Different Planting Patterns (2009)

The effects of weed community and alfalfa on crops in cropping patterns and density were studied.A factor was the cropping pattern,including planting only corns and interplanting of corn and alfalfa.B factor was the weed density of mixed group.On the basis of the weed community composition in past year and according to the proportion of mixed population of weeds,six different weed density treatments,including 0,25,50,100,200,400 weeds per square meters were established.The conclusion was drawn that: chlorophyll a and total chlorophyll content of maize under two cropping patterns were significantly different when the weed density was 25 plant/m2,chlorophyll b of maize under two cropping patterns were significantly different when the weed density was 100 plant/m2.The MDA content in corns by single planting was higher than that by inteplanting of corn and alfalfa.In the grain-filling stage,the soluble protein in corns was the highest,there was a significant difference in the two planting ways when the weed density were 100 and 200 plants/m2.
A novel method to enhance quantum yield of silica-coated quantum dots for biodetection (2008)

In this paper, based on selecting the appropriate type of quantum dots (QDs), a novel method is developed to enhance the quantum yield (QY) of silica-coated QD nanoparticles (SQDNPs). The effect of varying types of QDs on the QY after silica encapsulation is systematically studied. The results show that QDs with appropriate structure and composition of shells can much better retain the initial QY after silanization. The seven-layered shell/core QDs with QY of 47.8% nearly completely retain the original QY and is the best type among six types of QDs for silica modification. In the aspect of shell composition, the CdS plays an important role for QY retention since the lattice mismatch between CdSe and CdS is lower than that of CdSe and ZnS. After the appropriate type of QDs is chosen for silica coating, the highly fluorescent SQDNPs are chemically modified with amine, thiol and carboxyl groups, and then labeled by antibodies for particle-based immunofluorescence assay. The results indicate that the SQDNPs-antibody bioconjugates are alternative fluorescent probes useful for biodetection.
Effects of Melatonin and Pycnogenol on Small Artery Structure and Function in Spontaneously Hypertensive Rats (2010)

It was suggested that oxidative stress has a key role in the development of endothelial dysfunction, as well as microvascular structural alterations. Therefore, we have investigated 2 substances with antioxidant properties: melatonin and Pycnogenol. We treated 7 spontaneously hypertensive rats (SHRs) with melatonin and 7 with Pycnogenol for 6 weeks. We compared results obtained with those observed in 7 SHRs and 7 Wistar-Kyoto normotensive control rats kept untreated. Mesenteric small resistance arteries were dissected and mounted on a wire myograph, and a concentration-response curve to acetylcholine was performed. Aortic contents of metalloproteinase 2, Bax, inducible NO synthase, and cyclooxygenase 2 were evaluated, together with the aortic content of total collagen and collagen subtypes and apoptosis rate. A small reduction in systolic blood pressure was observed. A significant improvement in mesenteric small resistance artery structure and endothelial function was observed in rats treated with Pycnogenol and melatonin. Total aortic collagen content was significantly greater in untreated SHRs compared with Wistar-Kyoto control rats, whereas a full normalization was observed in treated rats. Apoptosis rate was increased in the aortas of untreated SHRs compared with Wistar-Kyoto control rats; an even more pronounced increase was observed in treated rats. Bax and metalloproteinase 2 expressions changed accordingly. Cyclooxygenase 2 and inducible NO synthase were more expressed in the aortas of untreated SHRs compared with Wistar-Kyoto control rats; this pattern was normalized by both treatments. In conclusion, our data suggest that treatment with Pycnogenol and melatonin may protect the vasculature, partly independent of blood pressure reduction, probably through their antioxidant effects.
Strength conditioning in older men: skeletal muscle hypertrophy and improved function (1988)

The effects of strength conditioning on skeletal muscle function and mass were determined in older men. Twelve healthy untrained volunteers (age range 60-72 yr) participated in a 12-wk strength training program (8 repetitions/set; 3 sets/day; 3 days/wk) at 80% of the one repetition maximum (1 RM) for extensors and flexors of both knee joints. They were evaluated before the program and after 6 and 12 wk of training. Weekly measurements of 1 RM showed a progressive increase in strength in extensors and flexors. By 12 wk extensor and flexor strength had increased 107.4 (P less than 0.0001) and 226.7% (P less than 0.0001), respectively. Isokinetic peak torque of extensors and flexors measured on a Cybex II dynamometer increased 10.0 and 18.5% (P less than 0.05) at 60 degrees/s and 16.7 and 14.7% (P less than 0.05) at 240 degrees/s. The torque-velocity relationship showed an upward displacement of the curve at the end of training, mainly in the slow-velocity high-torque region. Midthigh composition from computerized tomographic scans showed an increase (P less than 0.01) in total thigh area (4.8%), total muscle area (11.4%), and quadriceps area (9.3%). Biopsies of the vastus lateralis muscle revealed similar increases (P less than 0.001) in type I fiber area (33.5%) and type II fiber area (27.6%). Daily excretion of urinary 3-methyl-L-histidine increased with training (P less than 0.05) by an average 40.8%. Strength gains in older men were associated with significant muscle hypertrophy and an increase in myofibrillar protein turnover.
Unveiling two deuteration effects on hydrogen-bond breaking process of water isotopomers (2019)

The quantum nature of hydrogen bonds in water manifests itself in peculiar physicochemical isotope effects: While deuteration often elongates and weakens the hydrogen bonds of typical hydrogen-bonded systems composed of bulky constituent molecules, it elongates but strengthens the hydrogen bonds of water molecular aggregates. The origin of this unique isotope effect of water molecules remains to be elucidated at the molecular level. By means of isotope-selective measurements on the sublimation of water ices with various H/D compositions, we disentangle two opposite deuteration effects on the hydrogen-bond breaking process of water molecules: (1) Deuterating a desorbing water molecule increases the energy needed for desorption ${E}_{d}$, while (2) deuterating water molecules neighboring a desorbing molecule reduces its ${E}_{d}$. The increase in ${E}_{d}$ originates from zero-point energy in the hindered rotation of the desorbing molecule, whereas the decrease in ${E}_{d}$ is caused by quantum anharmonic couplings between the inter- and intramolecular vibrational modes involved in the hydrogen-bonding interactions of desorbing water molecules. On the basis of these findings, we discuss the peculiar nature of hydrogen bonds of water molecules in comparison with bulky hydrogen-bonded molecules.
Modeling and Validation of a 3D Velocity Structure for the Santa Clara Valley, California, for Seismic-Wave Simulations (2006)

A 3D seismic velocity and attenuation model is developed for Santa Clara Valley, California, and its surrounding uplands to predict ground motions from scenario earthquakes. The model is developed using a variety of geologic and geophysical data. Our starting point is a 3D geologic model developed primarily from geologic mapping and gravity and magnetic surveys. An initial velocity model is constructed by using seismic velocities from boreholes, reflection/refraction lines, and spatial autocorrelation microtremor surveys. This model is further refined and the seismic attenuation is estimated through waveform modeling of weak motions from small local events and strong-ground motion from the 1989 Loma Prieta earthquake. Waveforms are calculated to an upper frequency of 1 Hz using a parallelized finite-difference code that utilizes two regions with a factor of 3 difference in grid spacing to reduce memory requirements. Cenozoic basins trap and strongly amplify ground motions. This effect is particularly strong in the Evergreen Basin on the northeastern side of the Santa Clara Valley, where the steeply dipping Silver Creek fault forms the southwestern boundary of the basin. In comparison, the Cupertino Basin on the southwestern side of the valley has a more moderate response, which is attributed to a greater age and velocity of the Cenozoic fill. Surface waves play a major role in the ground motion of sedimentary basins, and they are seen to strongly develop along the western margins of the Santa Clara Valley for our simulation of the Loma Prieta earthquake.
Force and Stiffness Changes During Ilizarov Leg Lengthening (1990)

Biomechanical considerations of limb lengthening procedures are fundamental to their clinical outcome. The purpose of this study was to determine the relationships among force, stiffness, and distracted length in a patient whose leg was lengthened 50 mm with the Ilizarov procedure. A modified Ilizarov apparatus with force transducers in its three columns was surgically applied to the left tibia of an 11-year-old female patient after corticotomy of the proximal metaphysis. The leg was distracted 0.25 mm four times daily for 50 days, commencing six days after surgery. At approximately weekly intervals, forces at rest were recorded before and after distraction. Resting predistractional force magnitudes increased almost linearly during the first three weeks of lengthening, from 49 N to 223 N. The rate of increase slowed markedly thereafter with a further force increase of 11 N in the next three weeks. The stiffness of the limb, derived from the change in force accompanying the 0.25-mm change in length, increased by approximately 3.9%/mm of distracted length with 95% confidence limits of 6.8% and 0.9%. These results show marked differences from the nonlinearly increasing force-displacement relationship during in vitro limb distraction.
Rethinking Lossy Compression: The Rate-Distortion-Perception Tradeoff (2019)

Lossy compression algorithms are typically designed and analyzed through the lens of Shannon's rate-distortion theory, where the goal is to achieve the lowest possible distortion (e.g., low MSE or high SSIM) at any given bit rate. However, in recent years, it has become increasingly accepted that "low distortion" is not a synonym for "high perceptual quality", and in fact optimization of one often comes at the expense of the other. In light of this understanding, it is natural to seek for a generalization of rate-distortion theory which takes perceptual quality into account. In this paper, we adopt the mathematical definition of perceptual quality recently proposed by Blau & Michaeli (2018), and use it to study the three-way tradeoff between rate, distortion, and perception. We show that restricting the perceptual quality to be high, generally leads to an elevation of the rate-distortion curve, thus necessitating a sacrifice in either rate or distortion. We prove several fundamental properties of this triple-tradeoff, calculate it in closed form for a Bernoulli source, and illustrate it visually on a toy MNIST example.
Development of an Active, Large Volume, Discrete Seawater Sampler for Autonomous Underwater Vehicles (2007)

Engineers and researchers at the Monterey Bay Aquarium Research Institute (MBARI) have developed a water sampler that rapidly captures a 2-liter sample of seawater. This syringe-like sampler is spring actuated and can acquire a full sample in less than two seconds. This sampler will complement the wide array of sensors currently integrated on MBARI's autonomous underwater vehicles (AUVs). Although many properties of seawater can be analyzed by AUV onboard sensors, these measurements alone are often insufficient to fully investigate important scientific questions. Returning a discrete sample of seawater from the field, via an AUV, for laboratory analysis will expand the spectrum of research possible with AUV platforms. Using AUV onboard intelligence, designated sites and important phenomena can be targeted for acquiring water samples. This paper addresses the development, testing, and initial deployments of this sampler.
Digital Simulation of Sound Transmission in Reverberant Spaces (1970)

Digital computers, through their capability for accurate simulation of complex phenomena, have permitted new insights into a number of important problems arising in sound transmission in reverberant spaces: (1) Reverberation theories, based on the geometrical acoustics, are being refined by ray-tracing studies on digital computers. These studies have revealed significant discrepancies in existing reverberation-time formulas and unexpected large dependencies of the decay rate on the shape of the enclosure and the distribution of sound-absorbing materials. (2) Starting with reverberation-free speech or music signals as inputs, computers can add echoes and reverberation with specified delays, spectral content, and decay characteristics. The computer produces several output signals that—when radiated from loudspeakers in an anechoic chamber—produce, at a listener's ears, sound-pressure waves resembling those in real halls. To ensure “externalization” and proper directions of echo arrivals, the computer program is based on the measured sound diffraction around the listener's head. This digital simulation method is useful to “preaudit” architectural designs before construction and to investigate subjective correlates of a wide variety of reverberation processes. (3) Digital computers have made possible the simulation of frequency and space response of stationary sound fields and the calculation of their statistical properties. These properties are important for the design of electroacoustic systems and the evaluation of measurements in reverberant enclosures.
Fuzzy Clustering in Biochemical Analysis of Cancer Cells (2005)

Currently there is considerable effort investigating whether infrared spectroscopy can be used as a diagnostic probe to identify early stages of cancer since these techniques are sensitive to biological changes within cells. Cluster analysis is often used to try and unravel complex vibrational images. In this paper, a Fuzzy C-Means (FCM) based model selection algorithm was used to automatically cluster sets of infrared spectral data taken from lymph node tissue sections. Initial results were often prone to the creation of excessive clusters in comparison with clinical diagnosis which is partly due to the complexities of biological tissue. A new method to merge clusters was developed with the ability to successfully find and combine the two most similar clusters in order to address this problem. This new method was applied to four sets of infrared spectral data, from two types of human cancers (lymph node and oral). The experimental results clearly show that this new method can successfully combine the most similar clusters together and potentially improve the accuracy of diagnosis.
Limitations and solutions for the use of integrated λ/4-Shifted distributed Bragg resonators in wavelength-division multiplexing applications (1994)

A new paradigm for writing long-range, spatially-coherent multiple-quarter-wave shifted Bragg gratings is described. The implementation of such a paradigm is essential for fabricating integrated optical devices for wavelength-division multiplexed applications.