cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurements of aerosol product in an axisymmetric co-flow jet

An experimental investigation explored the effects of varying reactant concentration and Reynolds number on the formation of product in a jet of air/N2/HCl flowing into a co-issuing stream of air/NH3. Turbulent mixing resulted in the production of NH4Cl particles by a chemical reaction with negligible heat release. Laser light was elastically scattered in the transition regime between Rayleigh and Mie scattering from the particles. Scattered light intensity served as an indicator of particle mass concentration. Radial profiles of mean and root mean square concentrations were obtained in the self-similar far field region of the jet. The stoichiometric mixture fraction was varied by varying the concentration of NH3 in the co-flowing stream. It was found that the “flame” length decreased with increasing stoichiometric mixture fraction, and was independent of Reynolds number. The overall amount of product decreased as the stoichiometric mixture fraction was increased from 0.06 to 0.27, while the amount of limiting reactant was the same in both cases.
Simple guitar string system for teaching fundamental concepts in a variety of ECE and ME courses

This paper presents an inexpensive, portable experimental platform that, when coupled with student-owned data acquisition boards, can be used in a variety of lecture-based courses including signals and systems, circuits, electronics, electromagnetics, system dynamics, and vibrations. This paper presents the model, simulation results, and experimental results obtained from a data acquisition board.
Structural characterization of the protein cce_0567 from Cyanothece 51142, a metalloprotein associated with nitrogen fixation in the DUF683 family.

Abstract The genomes of many cyanobacteria contain the sequence for a small protein with a common “Domain of Unknown Function” grouped into the DUF683 protein family. While the biological function of DUF683 is still not known, their genomic location within nitrogen fixation clusters suggests that DUF683 proteins may play a role in the process. The diurnal cyanobacterium Cyanothece sp. PCC 51142 contains a gene for a protein that falls into the DUF683 family, cce_0567 (78 aa, 9.0 kDa). In an effort to elucidate the biochemical role DUF683 proteins may play in nitrogen fixation, we have determined the first crystal structure for a protein in this family, cce_0567, to 1.84 A resolution. Cce_0567 crystallized in space group P2 1 with two protein molecules and one Ni 2+ cation per asymmetric unit. The protein is composed of two α-helices, residues P11 to G41 (α1) and L49–E74 (α2), with the second α-helix containing a short 3 10 -helix (Y46–N48). A four-residue linker (L42–D45) between the helices allows them to form an anti-parallel bundle and cross over each other towards their termini. In solution it is likely that two molecules of cce_0567 form a rod-like dimer by the stacking interactions of ∼ 1/2 of the protein. Histidine-36 is highly conserved in all known DUF683 proteins and the N2 nitrogen of the H36 side chain of each molecule in the dimer is coordinated with Ni 2+ in the crystal structure. The divalent cation Ni 2+ was titrated into 15 N-labeled cce_0567 and chemical shift perturbations were observed only in the 1 H– 15 N HSQC spectra for residues at, or near, the site of Ni 2+ binding observed in the crystal structure. There was no evidence for an increase in the size of cce_0567 upon binding Ni 2+ , even in large molar excess of Ni 2+ , indicating that a metal was not required for dimer formation. Circular dichroism spectroscopy indicated that cce_0567 was extremely robust, with a melting temperature of ∼ 62 °C that was reversible.
Perioperative Management of Pheochromocytoma

Pheochromocytomas are rare neuroendocrine tumors that produce and store catecholamines. Without adequate preparation, the release of excessive amounts of catecholamines, especially during anesthetic induction or during surgical removal, can produce life-threatening cardiovascular complications. This review focuses on the perioperative management of pheochromocytoma/paragangliomas, initially summarizing the clinical aspects of the disease and then highlighting the current evidence available for preoperative, intraoperative, and postoperative anesthetic management.
Parenteral and oral alimentation in the treatment of the nonspecific protracted diarrheal syndrome of infancy

Clinical experience in the management of 10 infants who had protracted diarrhea which started before 3 months of age is presented. The first 7 patients died; clearly identifiable pathologic entity was not established as a cause of the diarrhea, and treatment was ineffectual. The last 3 patients were initially evaluated in accord with a prearranged diagnostic protocol and then were started on a therapeutic regimen which included intravenous administration of hypertonic solutions of protein hydrolysate, dextrose, and alcohol and oral feedings of medium-chain triglycerides. This regimen could supply up to 400 calories per kilogram per day. The infants grew and developed while on this treatment and tolerated it for periods of up to 18 weeks without any serious problems. A specific cause for the diarrhea in the 3 infants who recovered could not be demonstrated. However, after recovery, each had an adverse reaction temporally associated with the change from Nutramigen to Enfamil or whole milk feedings, thus suggesting the presence of milk protein allergy.
Inactivation kinetics of adenovirus serotype 2 with monochloramine.

Abstract The effect of pH (6–10), temperature (10–30 °C), disinfectant concentration (1–11 mg/l as Cl2), and ammonia nitrogen-to-chlorine molar ratio (1.3–52) on the inactivation kinetics of adenovirus serotype 2 with monochloramine was investigated by performing batch-reactor experiments with synthetic 0.01 M buffer (phosphate or borate) solutions. The inactivation kinetics was independent of monochloramine concentration and ammonia nitrogen-to-chlorine molar ratio but had strong pH dependence, with the rate of inactivation decreasing with increasing pH. The kinetics at pH 6 and 8 were consistent with pseudo-first-order kinetics, while curves at pH 10 were characterized by a lag phase followed by a pseudo-first-order phase. The rate of inactivation increased with increasing temperature-activation energies of 56.5 kJ/mole (pH 8) and 72.6 kJ/mole (pH 10). The results obtained in this study revealed that monochloramine disinfection might not generally provide adequate control of adenoviruses in drinking water at high pH and low temperature.
Effects of pressure and humidity on positive corona inception from thundercloud hydrometeors

This paper reports a study on the inception condition of positive corona discharges around thundercloud hydrometeors that are simulated as a spherical point electrode. The corona inception from the hydrometeor is investigated using a model developed by Naidis (2005), which suggests that the discharge becomes self-sustaining when the number of ionizing photons produced by all secondary electron avalanches is equal to that by a primary avalanche. For an isolated, charged hydrometeor in dry air of varying pressure, the results show that the onset of positive corona discharges from a large hydrometeor at high pressure requires a stronger avalanche multiplication than those from a small hydrometeor at low pressure. The onset voltage and surface electric field are obtained for thundercloud hydrometeors of different radii. For a hydrometeor of a radius of 1 mm at atmospheric pressure, the onset surface field reaches about 2.75 times the conventional breakdown threshold field. In humid air (a gas mixture of dry air and water vapor), it is found that a stronger avalanche is required for the corona onset, and the effect of humidity is more pronounced for large hydrometeors. The absorption of the ionizing photons by water vapor is the main reason why a stronger avalanche is required for the corona inception in humid air. As corona discharges from an isolated hydrometeor remove the charge on it, this discharging mechanism sets an upper limit on hydrometeor charge that agrees reasonably with the reported observations of maximum precipitation charge. Finally, we discuss the corona inception condition from a charged hydrometeor in non-zero ambient field of thundercloud condition.
Octreotide for refractory Diarrhea associated with capecitabine

Objective: To describe the effect of low-dose subcutaneous octreotide on refractory diarrhea associated with capecitabine. Case Summary: A 67-year-old white woman with recurrent metastatic breast cancer received monotherapy with capecitabine after failing docetaxel. The first 2 consecutive capecitabine cycles were well tolerated. The patient, however, developed severe watery diarrhea after the third cycle. Diphenoxylate, atropine, loperamide, and attapulgite, along with conventional supportive measures, did not significantly improve the diarrhea, resulting in prolonged hospitalization. Octreotide 100 μg every 8 hours was administered subcutaneously. Immediate relief in stool frequency was observed during the first day. The stool became more formed on the next day. The patient was ready for discharge after learning how to perform subcutaneous injections. Octreotide was continued at home for 3 more days. After discontinuation of octreotide, no recurrent diarrhea occurred. Capecitabine was not reinitiated. Discussion: Diarrhea is a potentially life-threatening complication from treatment with capecitabine, an oral fluoropyrimidine analog. Octreotide has shown efficacy for diarrhea from many conditions, including chemotherapy with irinotecan and intravenous fluoropyrimidines such as fluorouracil. Our report suggests that octreotide also is effective for diarrhea associated with capecitabine. The patient's rapid response shortened her hospital stay and improved her quality of life. Conclusions: In our patient, subcutaneous octreotide, along with other conventional antidiarrheal therapies, was associated with rapid resolution of refractory diarrhea attributed to capecitabine.
A non-equilibrium kinetic description of shock-wave structure

A formulation for the shock-wave structure is devised by the approximation of Boltzmann's equation by a simpler kinetic model. Initially, the distribution function in Boltzmann's collision integral is expressed in terms of a function of deviation from local equilibrium, the magnitude of which is unrestricted, and the analysis is specialized to hard sphere molecules. A model is then derived by assigning to the deviation function the first-order term of Chapman-Enskog's sequence which leads to Navier-Stokes equations. The model equation is shown to possess a description of a gas in a non-equilibrium state and to imply a Prandtl number value of $\frac{2}{3}$, the formulation also containing the Bhatnagar-Gross-Krook model as a special case. In applying the kinetic model to the shock problem, the collision frequency of the loss term is replaced by a set of mean frequencies (independent of the molecular velocity) each of which characterizes a specific macroscopic quantity. The shock equations are evaluated numerically for argon employing an interation scheme that is initiated by the Navier-Stokes solution. One iteration only to the flow variables is performed. For weak shocks the iteration proves to be in very close agreement with the Navier-Stokes solution for a Prandtl number of $\frac{2}{3}$; at higher Mach numbers, the iteration predicts a progressively larger deviation, especially in the temperature profile. In addition, the density and velocity profiles exhibit a 'kink' at Mach numbers 5 and 10. Unlike the Navier-Stokes predictions, the results also show that for high Mach numbers the total enthalpy within the shock no longer remains sensibly constant.
Percutaneous nephrostomy using real-time sonographic guidance

The technique of percutaneous antegrade pyelography and percutaneous nephrostomy has been well described. In the past these procedures have used fluoroscopy with or without intravenous contrast material, standard gray scale sonography, or a combination of both for localization [1 -7]. Experience with early generation real-time sonography scanners in aiding localization for percutaneous nephrostomy has been encouraging [6, 7]. We report our experience using modern real-time sonography in directing percutaneous nephrostomy tube placement.
Dynamics of Phenanthrenequinone on Carbon Nano-Onion Surfaces Probed by Quasielastic Neutron Scattering

We used quasielastic neutron scattering (QENS) to study the dynamics of phenanthrenequinone (PQ) on the surface of onion-like carbon (OLC), or so-called carbon onions, as a function of surface coverage and temperature. For both the high- and low-coverage samples, we observed two diffusion processes; a faster process and nearly an order of magnitude slower process. On the high-coverage surface, the slow diffusion process is of long-range translational character, whereas the fast diffusion process is spatially localized on the length scale of ∼4.7 A. On the low-coverage surface, both diffusion processes are spatially localized; on the same length scale of ∼4.7 A for the fast diffusion and a somewhat larger length scale for the slow diffusion. Arrhenius temperature dependence is observed except for the long-range diffusion on the high-coverage surface. We attribute the fast diffusion process to the generic localized in-cage dynamics of PQ molecules, and the slow diffusion process to the long-range translatio...
Downhole Water Sink (DWS) Completion Enchance OIL Recovery in Reservoirs with Water Coning Problem

To date, field trials of wells with DWS completions have shown that this new technology could control water coning and increase oil production rate. None of these tests, however, was long enough to show DWS potential to improve process of oil recovery comparing to conventional wells. Presented in this paper are results from a recent project of the RD A five-fold increase of the oil production rate was reached without changing the rate at the top completion - by adjusting the drainage rate at the bottom completion. The results also showed a 70-percent increase of oil recovery; from 0.521 up to 0.882 for conventional and DWS completions, respectively. The computer-simulated experiments with commercial reservoir simulator confirmed the thesis on better recovery with the DWS completions by showing a 30-percent increase of recovery factor from 0.61 to 0.79 for conventional and DWS completions, respectively. The results also gave a five-fold reduction of the time required to reach the limiting 0.98 value of water cut. However, accelerated recovery process with DWS required a substantial up to 3.5-fold increase of total water production. The simulation experiments clearly showed that the main advantage of using DWS is its flexibility of controlling the recovery process. For conventional completions, the recovery could be slightly increased by reducing production rates and largely increasing production times. For DWS, on the other hand, production process could be optimized for maximum recovery, minimum time, or minimum cumulative water produced by seeking a best combination of the top and bottom rates.
Index-tracking optimal portfolio selection

This paper considers a portfolio selection problem with multiple risky assets where the portfolio is managed to track a benchmark market barometer, such as the S&P 500 index. A tracking optimization model is formulated and the tracking-efficient (TE) portfolios are shown to inherit interesting properties compared with Markowitz mean-variance (MV) optimal portfolios. In comparison to an MV-portfolio, both the beta and the variance of a TE-portfolio are higher by fixed amounts that are independent of the expected portfolio return. These differences increase with index variance, are convex quadratic in the asset betas, and depend on the asset means and covariance matrix. Furthermore, a TE portfolio is obtained by simply extending an MV portfolio by constant adjustments to portfolio weights, independent of the specified mean return of the portfolio, but dependent on the index variance and asset return parameters. Consequently, at lower thresholds of risk, TE portfolios are better-diversified than MV portfolios.
Measurements of the Effectiveness of Concave Spherical Dimples for Enhancement Heat Transfer

Measurements of the heat transfer enhancement effects of concave spherical dimples have been performed under hydrogen–oxygen hot-fire conditions in a subscale combustion chamber. Seven configurations were tested with a range of area densities from 15–70% and depth-to-diameter ratios of 0.111 to 0.333. Enhancements of 15–82% relative to a smooth surface weremeasured. TheReynolds number was varied by a factor of 5 andwas found to have an insignificant effect on the enhancement factor.Results correlatedwellwith previous studies conductedunder coldflow conditions with similar values of area fraction, depth-to-diameter ratio, and channel height-to-dimple diameter. These results are suitable for use by analysts and designers considering the use of heat transfer enhancement features on hot-gas walls for example in the design of high-performing expander cycle engines. Concave spherical dimples may have advantages over other approaches for enhancing heat transfer, such as protruding ribs with respect to the integrity of the chamberwall and the efficiency of the heat transfer enhancement relative to the associated increase in skin friction.
Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields

Abstract A direct ethanol fuel cell has been operated under sinusoidal (AC) potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At 80 °C, faradaic yields of CO2 as high as 25% have been achieved with a PtRu anode catalyst, while the maximum CO2 production at constant potential was 13%. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO. These results will be important in the optimization of operating conditions for direct ethanol fuel cells, where the benefits of potential cycling are projected to increase as catalysts that produce CO2 more efficiently are implemented.
A compact ion source and accelerator based on a piezoelectric driver

Compact ion sources and accelerators using piezoelectric devices for the production of energetic ion beams are being evaluated. A coupled source-accelerator is being tested as a neutron source to be incorporated into oil-well logging diagnostics. Two different ion sources are being investigated, including a piezoelectric transformer-based plasma source and a silicon-based field ion source. The piezoelectric transformer plasma ion source uses a cylindrical, resonantly driven piezoelectric crystal to produce high voltage inside a confined volume filled with low pressure deuterium gas. The plasma generated in the confined chamber is ejected through a small aperture into an evacuated drift region. The silicon field ion source uses localized electric field enhancement produced by an array of sharp emitters etched into a silicon blank to produce ions through field desorption ionization. A second piezoelectric device of a different design is used to generate an accelerating potential on the order of 130 kV; this potential is applied to a deuterated target plate positioned perpendicular to the ion stream produced by either plasma source. This paper discusses the results obtained by the individual components as they relate to the final neutron source.
Is a metabolic enzyme complex involved in the efficient and accurate control of Ipecac alkaloid biosynthesis in Psychotria ipecacuanha

Ipecac alkaloids produced in the medicinal plant Psychotria ipecacuanha, such as emetine and cephaeline, possess a monoterpenoid-tetrahydroisoquinoline skeleton, which is formed by condensation of dopamine and secologanin. The condensation products are deglucosylated, and the resulting aglycon is further processed to protoemetine, which is condensed with the second molecule of dopamine, followed by conversion into cephaeline and emetine. Although four hydroxy groups derived from two molecules of dopamine need to be methylated to form emetine, the order of O-methylation reactions had been veiled. We recently identified three Ipecac alkaloid O-methyltransferases (IpeOMT1-IpeOMT3) that are sufficient for catalyzing O-methylations of all four hydroxy groups. Detailed characterization of their catalytic properties with integration of that of the previously identified Ipecac alkaloid β-glucosidase (IpeGlu1) revealed a large portion of the biosynthetic pathway of Ipecac alkaloids. The results provide proof-of-concept to the significance and the usefulness of the biosynthetic pathway strategy by EST analysis coupled with recombinant enzyme characterization. At the same time, however, the results raised an intriguing question about the subcellular network between the biosynthetic enzymes and intermediates. Here, we provide additional discussion about this point and indicate what remains to be elucidated.
Sexual Dimorphism in Physiological Performance of Whiptail Lizards (Genus Cnemidophorus)

ABSTRACT Numerous studies have examined sexual dimorphism in the morphology and behavior of vertebrates; very few, however, have explicitly investigated the possibility of gender differences in physiological performance, despite the observations of such differences in humans. In this study, I investigated physiological sexual dimorphism in the lizard genus Cnemidophorus by measuring five whole‐animal traits, all of which are likely to influence fitness in these species: burst speed, endurance, maximal exertion capacity, standard metabolic rate, and evaporative water loss rate. Because at least some of these traits are known to be strongly influenced by body size, I tested for dimorphism using both absolute and size‐corrected trait values. An examination of six Cnemidophorus species and subspecies revealed a strong trend toward higher absolute trait values in males for all variables except endurance. Most of the dimorphism in standard metabolic rate and evaporative water loss rate could be explained by dif...
Preserving Routes during Fast Convergence

We present a protocol for maintaining a routing tree that is maximal with respect to any given (bounded and monotonic) routing metric. This protocol has three adaptive properties. First, the protocol is stabilizing: starting from any state, the protocol stabilizes to a state where a maximal tree is present. Second, the protocol assumes no upper bound on the length L of the longest network path, nonetheless, its stabilization time is O (L deg), where deg is the node degree in the network. Third, the spanning tree remains connected while adapting to a change in the edge weights in the network. This last property makes the protocol suitable for a routing policy that ensures each message is delivered to its destination, even while the routing tree is adapting to the new edge weights.
A Data Intensive Statistical Aggregation Engine: A Case Study for Gridded Climate Records

Satellite derived climate instrument records are often highly structured and conform to the "Data-Cube" topology. However, data scales on the order of tens to hundreds of Terabytes make it more difficult to perform the rigorous statistical aggregation and analytics necessary to investigate how our climate is changing over time and space. It is especially cumbersome to supply the full derivation (provenance) of this analysis, as is increasingly required by scientific conferences and journals. In this paper, we address our approach toward the creation of a 55 Terabyte decadal record of Outgoing Long wave Spectrum (OLS) from the NASA Atmospheric Infrared Sounder (AIRS), and describe our open source data-intensive statistical aggregation engine "Gridderama" intended primarily for climate trend analysis, and may be applicable to other aggregation problems involving large structured datasets.
Imputation techniques for incomplete data in quadratic discriminant analysis

We have compared the efficacy of five imputation algorithms readily available in SAS for the quadratic discriminant function. Here, we have generated several different parametric-configuration training data with missing data, including monotone missing-at-random observations, and used a Monte Carlo simulation to examine the expected probabilities of misclassification for the two-class quadratic statistical discrimination problem under five different imputation methods. Specifically, we have compared the efficacy of the complete observation-only method and the mean substitution, regression, predictive mean matching, propensity score, and Markov Chain Monte Carlo (MCMC) imputation methods. We found that the MCMC and propensity score multiple imputation approaches are, in general, superior to the other imputation methods for the configurations and training-sample sizes we considered.
Time for a neonatal–specific consensus definition for sepsis

Objective To review the accuracy of the pediatric consensus definition of sepsis in term neonates and to determine the definition of neonatal sepsis used. Study selection The review focused primarily on pediatric literature relevant to the topic of interest. Conclusions Neonatal sepsis is variably defined based on a number of clinical and laboratory criteria that make the study of this common and devastating condition very difficult. Diagnostic challenges and uncertain disease epidemiology necessarily result from a variable definition of disease. In 2005, intensivists caring for children recognized that as new drugs became available, children would be increasingly studied and thus, pediatric-specific consensus definitions were needed. Pediatric sepsis criteria are not accurate for term neonates and have not been examined in preterm neonates for whom the developmental stage influences aberrations associated with host immune response. Thus, specific consensus definitions for both term and preterm neonates are needed. Such definitions are critical for the interpretation of observational studies, future training of scientists and practitioners, and implementation of clinical trials in neonates.
On the informativeness and accuracy of pooled testing in estimating prevalence of a rare disease: Application to HIV screening

SUMMARY When screening for a rare disease the large number of expected false positives makes it difficult to obtain a positive estimate of prevalence using current screening methodology. Pooled testing not only reduces the probability of this occurring, but also improves the accuracy of the estimator. These findings are illustrated by screening for the human immunodeficiency virus.
Intact negative feedback of four cardiac hormones in congestive heart failure

In 30 individuals with class III congestive heart failure (CHF), negative feedback of 4 cardiac peptide hormones, ie, long-acting natriuretic peptide (LANP), vessel dilator, kaliuretic peptide, and atrial natriuretic factor (ANF) from the same 126-amino acid (aa) prohormone were studied with the infusion of 100 ng/kg body weight (BW) for 60 minutes of each of the 4 cardiac hormones and a saline control (n = 6 for each). LANP decreased the circulating concentrations of vessel dilator, kaliuretic peptide, and ANF by 24%, 55%, and 30%, respectively. Vessel dilator decreased the circulating concentrations of ANF, kaliuretic peptide, and LANP 27%, 12%, and 62%, respectively. Kaliuretic peptide decreased the circulating concentrations of LANP, ANF, and vessel dilator 89%, 67%, and 70%, respectively. ANF decreased the circulating concentrations of LANP, vessel dilator, and kaliuretic peptide 88%, 59%, and 98%, respectively. Infusion of each of these 4 cardiac hormones decreased the excretion of the other 3 hormones into the urine by 11% to 92%. These results suggest that the respective cardiac hormones inhibit the release of each other rather than their breakdown, which would have increased their urinary concentrations. The feedback regulation of these hormones found previously in healthy humans is, thus, preserved in persons with CHF despite their increased endogenous circulating concentrations.
Artifactual power curves in forgetting

Recent studies of the mathematical relationship between time and forgetting suggest that it is a power function rather than an exponential function, a finding that has important theoretical consequences. Through computational analysis and reanalyses of published data, we demonstrate that arithmetic averaging of exponential curves can produce an artifactual power curve, particularly when there are large and systematic differences among the slopes of the component curves. A series of simulations showed that the amount of power artifact is small when the slopes of the component curves are normally or rectangularly distributed and when the performance measure is noise free. However, the simulations also showed that the artifact can be quite large, depending on the shape of the noise distribution and restrictions in the performance range. We conclude that claims concerning the form of memory functions should consider whether the data are likely to contain artifact caused by averaging or by the presence of range-restricted noise.
Increasing protein stability: Importance of ΔCp and the denatured state

Increasing the conformational stability of proteins is an important goal for both basic research and industrial applications. In vitro selection has been used successfully to increase protein stability, but more often site-directed mutagenesis is used to optimize the various forces that contribute to protein stability. In previous studies, we showed that improving electrostatic interactions on the protein surface and improving the β-turn sequences were good general strategies for increasing protein stability, and used them to increase the stability of RNase Sa. By incorporating seven of these mutations in RNase Sa, we increased the stability by 5.3 kcal/mol. Adding one more mutation, D79F, gave a total increase in stability of 7.7 kcal/mol, and a melting temperature 28°C higher than the wild-type enzyme. Surprisingly, the D79F mutation lowers the change in heat capacity for folding, ΔCp, by 0.6 kcal/mol/K. This suggests that this mutation stabilizes structure in the denatured state ensemble. We made other mutants that give some insight into the structure present in the denatured state. Finally, the thermodynamics of folding of these stabilized variants of RNase Sa are compared with those observed for proteins from thermophiles.
Holland environments as reinforcement systems

Holland's (1973, 1985) theory of vocational choice stipulates that model environments seek toreinforce the characteristic predispositions and attitudes of their corresponding personality types. The results of this longitudinal study of the self-perceptions of more than 2,000 graduates from eight types of colleges and universities (Carnegie Commission, 1971) generally support the validity of this premise. For example, graduates prepared in investigative environments have higher intellectual self-esteem scores and those prepared in artistic environments have higher artistic self-esteem scores, when pre- and postcollege measures are controlled. These general patterns are consistent for graduates from the eight institutional types. The implications of these findings are discussed for those who study the intra- and interinstitutional diversity of colleges and universities and their differential impact on student developmental patterns.
Juice viscosity as related to various juice constituents and fruit characters in tomatoes

Alcohol insoluble solid content (AIS) of tomato fruits was found to be highly correlated with viscosity. The correlation coefficient values, based on 12 cultivars, were r=0.97 for AIS of whole fruit extracted with 50% ethanol and r=0.94, extraction with 75% ethanol. The correlation of AIS with viscosity was high for outer pericarp, r=0.93, and inner pericarp, r=0.78, but low for locular contents, r=0.18. A principal component analysis indicated that fruit size, shape and firmness, total solids, proportion of outer and inner pericarp, and locular contents were not highly associated with either AIS or viscosity. Their consequences for a breeding program are discussed.
Operation and testing of the PULSTAR reactor intense slow positron beam and PALS spectrometers

An intense slow positron beam has been established at the 1-MW PULSTAR nuclear reactor. The beam is operational generating mono-energetic positrons with an energy of 1-keV. The maximum measured intensity slightly exceeds 109 e+/s. The beam is operated routinely with an intensity of approximately 5×108 e+/s. The positrons are generated through gamma-ray pair production interactions in two back-to-back banks of tungsten converter/moderators. The gamma-rays are produced in the PULSTAR core and by thermal neutron capture in a cadmium shroud that surrounds the tungsten. The primary utilization of the PULSTAR positron beam is the characterization of nanoscale structure in materials. Consequently, the beam has been equipped with two state-of-the-art PALS spectrometers. The first spectrometer is dedicated to measurements in materials such as metals and semiconductors. This spectrometer is based on pulsing and bunching of the primary beam and is currently operating with a timing resolution of approximately 390 picoseconds. The second spectrometer is dedicated to measurements in materials where positronium formation is promoted. The timing resolution of this spectrometer is designed to be ~ 0.5 nanosecond with an on-sample spot size of 1–2 mm. For both spectrometers, the energy of the positrons can be varied to allow depth profiling with on-sample intensity exceeding 106 e+/s.
Computation of the Instantaneous Frictional Losses of Internal Combustion Engine Components

An inverse dynamics scheme, based on a detailed differential-algebraic model of the crank-slider mechanism of a single cylinder internal combustion (IC) engine, is developed for the computation of the instantaneous frictional losses of engine components. The proposed approach requires accurate measurements of the independent and superfluous coordinates of the crank-slider mechanism as well as their time derivatives. This was achieved by implementing a sliding mode observer, previously developed by the authors, to provide the required estimates of the state variables. The aforementioned observer is suitable for use with differential-algebraic nonlinear equations of motion and was shown to be robust to both modeling imprecision and external disturbances. The digital simulation results show the capability of the combined inverse dynamics scheme with the observer in producing good estimates of the instantaneous frictional losses of the various engine components.Copyright © 2010 by ASME
Far IR spectra and electrical conductivity of Li and Na glasses by laboratory and computer simulation experiments

Abstract Admittance bridge measurements in the frequency range 0.1–106 Hz have been combined with Fourier transform interferometric spectral measurements in the range 1012−1013 to yield major portions of the complete a.c. field response function for some highly conducting lithium fluoroborate and sulfoborate glasses. Interpretation of these results has been assisted by studies of the detailed dynamics of ion motion revealed by ion dynamics computer simulation studies of high fictive temperature lithium and sodium silicate glasses, and of some unphysical glasses with (a) massive, slowly vibrating “oxygen ions”, and (b) light Na+ ions of the same mass as the Li ions.
Mesenchymal hamartoma of the liver demonstrating peripheral calcification in a 12-year-old boy.

Mesenchymal hamartoma of the liver is a rare benign hepatic tumor that typically presents in the first 2 years of life. Approximately 85% of affected children present before the age of 3 years and less than 5% present after the age of 5 years. Although spontaneous regression has been reported in this benign tumor, most mesenchymal hamartomas gradually increase in size and can reach enormous proportions. We present an atypical case of mesenchymal hamartoma in a 12-year-old boy. The boy’s age and presence of calcifications on CT demonstrate a unique presentation of this rare entity.
A square multiflare horn with 1-megawatt CW power-handling capability

The analysis and low-power testing of a square multiflare horn designed for 1-megawatt CW operation is described. Design considerations for the five-port input section are discussed. The required aperture modes are determined from radiation pattern considerations, and analysis of the multiflare section is carried out using mode matching. Measurements demonstrate that a circularly symmetric beam is produced with relatively low sidelobes.
A structural theory of explanation-based learning

The impact of Explanation-Based Learning (EBL) on problem-solving efficiency can vary greatly from one problem space to another. Although EBL has been tested experimentally, no theory has been put forth which predicts and explains when EBL will work and why. This dissertation presents such a theory. The theory makes use of Problem Space Graphs (PSGs), a graph representation of problem spaces that makes their structure explicit. The theory consists of four hypotheses: (1) The nonrecursive hypothesis. EBL is effective when it is able to curtail search via nonrecursive explanations. (2) The recursive hypothesis. EBL is not effective, on sufficiently uniform problem distributions, when it relies on recursive explanation. (3) The structural hypothesis. EBL's explanations are isomorphic to PSG subgraphs. (4) The complementary target concepts hypothesis. Target concepts whose proofs do not mirror the problem solver's plans are essential for EBL's effectiveness in recursive problem spaces. When applied to scPRODIGY/ scEBL, a state-of-the-art EBL system, the theory yields a number of surprising predictions. For example, the recursive hypothesis predicts that scPRODIGY/ scEBL will be foiled in a representational variant of the Blocksworld which has been stripped of its nonrecursive explanations. The structural hypothesis suggests that a static analyzer of problem space definitions can match EBL's performance. To test this prediction, a program (called scSTATIC) was written that extracts nonrecursive explanations from problem space definitions by constructing and analyzing PSGs. Unlike scPRODIGY/ scEBL, scSTATIC does not require training examples, utility evaluation, or rule compression. scSTATIC was tested in each of scPRODIGY/ scEBL's problem spaces. In the experiments, scSTATIC generated control knowledge from twenty six to seventy seven times faster than scPRODIGY/ scEBL, and was up to three times as effective in speeding up scPRODIGY.
Amphetamine infusions into the prefrontal cortex attenuate the sensitization to amphetamine

Abstract 1. 1. Adult male rats were implanted with chronic medial prefrontal cortex cannulae. 2. 2. On each of 5 consecutive days, rats received bilateral 0.5 ml intra-prefrontal cortex injections of either 5 mg d-amphetamine or saline, followed by a subcutaneous injection of either 1 mg/kg d-amphetamine or saline. 3. 3. Immediately after the drug treatments each rat was placed into a photocell equipped locomotor activity chamber for 60 min. 4. 4. Administration of d-amphetamine into the prefrontal cortex did not block the acute locomotor response to subcutaneous d-amphetamine nor did it in itself produce an increase in locomotor activity. However, prefrontal cortex amphetamine treatments did attenuate the sensitized locomotor effects of subcutaneous amphetamine that developed over trials/days. 5. 5. Dopamine in the prefrontal cortex may be involved in the development of amphetamine-induced behavioral sensitization.
Chromatin disruption and histone acetylation in regulation of the human immunodeficiency virus type 1 long terminal repeat by thyroid hormone receptor.

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) controls the expression of HIV-1 viral genes and thus viral propagation and pathology. Numerous host factors participate in the regulation of the LTR promoter, including thyroid hormone (T3) receptor (TR). In vitro, TR can bind to the promoter region containing the NF-κB and Sp1 binding sites. Using the frog oocyte as a model system for chromatin assembly mimicking that in somatic cells, we demonstrated that TR alone and TR/RXR (9-cis retinoic acid receptor) can bind to the LTR in vivo independently of T3. Consistent with their ability to bind the LTR, both TR and TR/RXR can regulate LTR activity in vivo. In addition, our analysis of the plasmid minichromosome shows that T3-bound TR disrupts the normal nucleosomal array structure. Chromatin immunoprecipitation assays with anti-acetylated-histone antibodies revealed that unliganded TR and TR/RXR reduce the local histone acetylation levels at the HIV-1 LTR while T3 treatment reverses this reduction. We further demonstrated that unliganded TR recruits corepressors and at least one histone deacetylase. These results suggest that chromatin remodeling, including histone acetylation and chromatin disruption, is important for T3 regulation of the HIV-1 LTR in vivo.
High Performance Isolated LDMOS with Source Spacer and Asymmetric Hetero-doped Architectures

A novel isolated LDMOS structure, using a simple yet effective concept of an asymmetric hetero-doped source/drain, is proposed. The asymmetric hetero-doped source/drain reduces the on-state resistance of the transistor due to the high n-type doping used for device drain drift, provides excellent ruggedness for parasitic NPN turned-on due to a minimized n+ source spacer, and also raises the device breakdown voltage due to charge compensation in the composite drain drift region. Therefore, the asymmetric hetero-doped source/drain structure allows the isolated LDMOS to have a high current handling capability with a small device size. Measured results show that a 24 V breakdown voltage new device with a low cost two-layer metal (Al) back-end achieves very low R (sp, on) of 16.6 mOmega.mm2. Furthermore, the new device with 65 V high-side capability achieves good isolation performance even when switching source/drain to -20 V and also gets a cut-off frequency of 13 GHz at a gate voltage of 5.5 V
Dual wavelength tunable IR dye laser system synchronously pumped by a ND:YAG laser

We describe a laser system that can provide synchronized pulses matched to the band gap of AlGaAs/GaAs and to InGaAsP/InP.
On Scheduling and Real-Time Capacity of Hexagonal Wireless Sensor Networks

Since wireless ad-hoc networks use shared communication medium, accesses to the medium must be coordinated to avoid packet collisions. Transmission scheduling algorithms allocate time slots to the nodes of a network such that if the nodes transmit only during the allocated time slots, no collision occurs. For real-time applications, by ensuring deterministic channel access, transmission scheduling algorithms have the added significance of making guarantees on transmission latency possible. In this paper we present a distributed transmission scheduling algorithm for hexagonal wireless ad-hoc networks with a particular focus on Wireless Sensor Networks. Afforded by the techniques of ad-hoc networks topology control, hexagonal meshes enable trivial addressing and routing protocols. Our transmission scheduling algorithm constructs network-wide conflict-free packet transmission schedule for hexagonal networks, where the overhead of schedule construction in terms of message exchanges is zero above and beyond that for topology control and other network control related functions. Furthermore, the schedule is optimal in the sense that the bottleneck node does not idle. We also present an implicit clock synchronization algorithm to facilitate scheduling. We derive the real time capacity of our scheduling algorithm. We present evaluations of our scheduling algorithm in the presence of topological irregularities using simulation.
A model and heat transfer correlation for rooftop integrated photovoltaics with a passive air cooling channel

Photovoltaic (PV) panels can experience undesirably high temperatures due to the heat input by that part of the absorbed solar radiation which is not converted into electricity. Regulation of the temperature rise is necessary to maintain maximum solar to electric conversion. One approach for temperature regulation, suitable for rooftop integrated PV, involves fitting an open channel beneath the PV module. The panels are cooled by radiation and free convection as ambient air rises through the channel. A scale analysis and numerical study of PV modules with a back mounted air channel provides heat transfer rates over a practical range of operating conditions and channel geometries. A generalized correlation for the average channel Nusselt number for the combined convective–radiative cooling is developed for modified channel Rayleigh numbers from 10 2 to 10 8 , channel aspect ratios between 15 and 50 and inclination angles between 30 and 90. The usefulness of a passive cooling channel to improve PV efficiency is illustrated by system analyses of typical PV modules. 2009 Elsevier Ltd. All rights reserved.
Computed tomography in acute disseminated encephalomyelitis

Computed tomographic (CT) scans were obtained for eleven patients with acute disseminated encephalomyelitis (ADE). Four patients had normal CT scans despite repeated examination. Abnormalities were found in seven patients and included cortical-enhancing lesions, low-density lesions in the deep white matter and basal ganglia, and edema of the brainstem. These findings support the hypothesis that both vascular injury and demyelination are involved in the pathogenesis of ADE. A delay between the onset of clinical signs and the appearance of lesions on CT scan was common. Clinical improvement was accompanied by improvement in CT abnormalities. There was a limited correlation between the clinical course and the anatomical distribution and type of abnormality seen on CT scan.
Minireview: kisspeptin neurons as central processors in the regulation of gonadotropin-releasing hormone secretion.

The Kiss1 gene encodes a family of peptides called kisspeptins, which bind to the G protein-coupled receptor GPR54. Kisspeptin(s) and its receptor are expressed in the forebrain, and the discovery that mice and humans lacking a functional GPR54 fail to undergo puberty and exhibit hypogonadotropic hypogonadism implies that kisspeptin signaling plays an essential role in reproduction. Studies in several mammalian species have shown that kisspeptins stimulate the secretion of gonadotropins from the pituitary by stimulating the release of GnRH from the forebrain after the activation of GPR54, which is expressed by GnRH neurons. Kisspeptin is expressed abundantly in the arcuate nucleus (Arc) and the anteroventral periventricular nucleus (AVPV) of the forebrain. Both estradiol and testosterone regulate the expression of the Kiss1 gene in the Arc and AVPV; however, the response of the Kiss1 gene to these steroids is exactly opposite between these two nuclei. Estradiol and testosterone down-regulate Kiss1 mRNA in...
Continuous Control in Bacterial Regulatory Circuits

We show that for two well-characterized regulatory circuits in Escherichia coli, Tn10 tetracycline resistance and porin osmoregulation, the transcriptional outputs in individual cells are graded functions of the applied stimuli. These systems are therefore examples of naturally occurring regulatory circuits that exhibit continuous control of transcription. Surprisingly, however, we find that porin osmoregulation is open loop; i.e., the porin expression level does not feed back into the regulatory circuit. This mode of control is particularly interesting for an organism such as E. coli, which proliferates in diverse environments, and raises important questions regarding the biologically relevant inputs and outputs for this system.