cssi/SciSciGPT-SciSciNet huggingface dataset:
CHONDRULES AS PRODUCTS OF DUST COLLISIONS WITH TOTALLY MOLTEN DROPLETS WITHIN A DUST-RICH NEBULAR ENVIRONMENT : AN EXPERIMENTAL INVESTIGATION

Abstract Chondrules are usually interpreted as the products of incomplete melting of mineral aggregates in the solar nebula and have textures controlled by the number of residual nuclei present after melting. If barred olivine (BO) chondrules formed by nearly total melting at their respective liquidi, i.e., over a wide temperature range, it is surprising that there are so few totally glassy chondrules. The occurrence of fine-grained, accretionary rims on chondrules suggests mineral dust in the chondrule-forming environment which might have collided with totally molten droplets to produce chondrule textures. We have, therefore, conducted experiments in which mineral dusts encounter molten droplets during their cooling at 500°C/h and cause nucleation. Our experiments reproduce the majority of common chondrule textures. The production of textures in our experiments is a function of the temperature at which dust is encountered, the number of dust grains encountered and, to a lesser extent, the mineralogy of the encountered mineral grains. Crystal growth rates increase with lower dust encounter temperatures giving a textural range with increasingly skeletal or elongated crystals for lower temperature encounters. We have produced some less commonly discussed types of chondrule textures, e.g., barred-olivine-porphyritic-olivine pyroxene (BO/POP) by dust seeding that have not been reproduced by the incomplete melting of starting materials. The reproduction of BO/POP and excentroradial textures by dust collisions, and the scarcity of natural totally glassy chondrules, suggest that formation by seeding of total melts was common for chondrules with the lowest liquidus temperatures, e.g., FeO-rich chondrules. From these seeding experiments we suggest that the maximum melting temperature chondrules experienced is limited only to the temperature at which evaporation of chondrule liquid occurs. However, we have reproduced the very fine-grained microporphyritic textures characteristic of Type IA chondrules only by incomplete melting. Such chondrules could not have reached average internal temperatures above their liquidus temperatures. The conclusion, that at least some chondrules formed from total melts that collided with mineral dust during cooling, indicates that chondrule formation occurred within a region of the nebula rich in mineral dust.
Applications of tuned mass dampers to improve performance of large space mirrors

Abstract In order for future imaging spacecraft to meet higher resolution imaging capability, it will be necessary to build large space telescopes with primary mirror diameters that range from 10 m to 20 m and do so with nanometer surface accuracy. Due to launch vehicle mass and volume constraints, these mirrors have to be deployable and lightweight, such as segmented mirrors using active optics to correct mirror surfaces with closed loop control. As a part of this work, system identification tests revealed that dynamic disturbances inherent in a laboratory environment are significant enough to degrade the optical performance of the telescope. Research was performed at the Naval Postgraduate School to identify the vibration modes most affecting the optical performance and evaluate different techniques to increase damping of those modes. Based on this work, tuned mass dampers (TMDs) were selected because of their simplicity in implementation and effectiveness in targeting specific modes. The selected damping mechanism was an eddy current damper where the damping and frequency of the damper could be easily changed. System identification of segments was performed to derive TMD specifications. Several configurations of the damper were evaluated, including the number and placement of TMDs, damping constant, and targeted structural modes. The final configuration consisted of two dampers located at the edge of each segment and resulted in 80% reduction in vibrations. The WFE for the system without dampers was 1.5 waves, with one TMD the WFE was 0.9 waves, and with two TMDs the WFE was 0.25 waves. This paper provides details of some of the work done in this area and includes theoretical predictions for optimum damping which were experimentally verified on a large aperture segmented system.
Gunfire performance of stabilized electro-optical sights

The design of stabilized electro-optical sights is a fairly mature technology. As such, many if not most of the major design tradeoffs are well know and characterized. These include basic gimbal configuration, gyroscope technology, servo control configuration, friction and inertia relationships, and structural-servo interactions. Most of these considerations and effects can be adequately treated with the classic design sequence: Design in the linear world, simulate in the non-linear world, and test in the real world. Experience has shown, however, that behavior of a stabilized sight during gunshock is difficult to predict, and the classic design sequence may ont predict gunshock problems until the late-in-the-cycle test phase. Further, evidence indicates that the system that provide excellent nominal stabilization performance may not perform well during gunshock. A discussion of a system in this regard is presented. Tradeoffs in stabilization versus gunshock performance are discussed. A section on suggested risk- reduction activities is also given.
Effect of Melting on the Electronic Spectra of Cs3NiCl5 and CsNiCl3

A method is described for measuring the optical absorption spectra of the crystalline and liquid phases of a transition‐metal salt close to the melting point. Supercooling the liquid permits measuring both phases at the same temperature. This technique was applied to Cs3NiCl5 (mp 547°C) and CsNiCl3 (mp 758°C). It was shown that when Cs3NiCl5 melts, the approximately tetrahedral arrangement of chlorides about nickel is affected only in minor ways, but when CsNiCl3 melts, the octahedral coordination geometry in the crystal is completely destroyed and replaced by a different distribution of geometries. The spectrum of molten CsNiCl3 and its temperature dependence is closely similar to that of nickel centers in molten KMgCl3 at high temperatures. The latter are believed to consist of a single broad distribution of geometries rather than two distinctly separate distributions. It was previously supposed that there are two distinctly different coordination geometries in molten CsNiCl3.
A Note on the Stark Effect in Diatomic Molecules

The hyperfine splitting of the energy levels of a polar diatomic molecule in a constant electric field caused by the presence of I \ifmmode\cdot\else\textperiodcentered\fi{} J interactions between each nucleus and the other charges of the molecule and a quadrupole interaction involving one of the nuclei is calculated. The calculation explains recent measurements of Trischka on molecular beams of CsF and KF. For weak fields a method is given for computing the fine structure splitting resulting from any form of interaction, provided one nucleus interacts more strongly than the other.
Comparison of multiplexed techniques for detection of bacterial and viral proteins.

Immobilized antibody microarrays were compared to the Luminex flow cytometry system that utilizes suspensions of polystyrene microbeads covalently coupled with capture antibodies. The two immunoass...
Effect of Silicone Quenching and Acid Polishing on the Strength of Glass

Soda-lime glass rods 5 mm in diameter were quenched in silicone oil and also in a saturated hydrocarbon oil of similar viscosity. The effect of etching, etching and quenching, and etching, quenching, and re-etching was examined in relation to the strength of the rods. Rods quenched in the silicone oil were no stronger than those quenched in the hydrocarbon oil. Etched rods had a strength of 300,000 psi. Quenching these high-strength rods reduced their strength to 110,000 psi. This decrease in strength may be explained in terms of the formation of crystalline and noncrystalline microflaws during the heating and cooling cycle. Re-etching, after quenching, resulted in rods with a maximum strength of 384,000 psi.
Determinants of Acute Kidney Injury Duration After Cardiac Surgery: An Externally Validated Tool

Background Acute kidney injury (AKI) duration after cardiac surgery is associated with poor survival in a dose-dependent manner. However, it is not known what perioperative risk factors contribute to prolonged AKI and delayed recovery. We sought to identify perioperative risk factors that predict duration of AKI, a complication that effects short and long-term survival. Methods We studied 4,987 consecutive cardiac surgery patients from 2002 through 2007. Acute kidney injury was defined as a 0.3 or greater (mg/dL) or 50% or greater increase in serum creatinine from baseline. Duration of AKI was defined by the number of days AKI was present. Stepwise multivariable negative binomial regression analysis was conducted using perioperative risk factors for AKI duration. The c-index was estimated by Kendall's tau. Results Acute kidney injury developed in 39% of patients with a median duration of AKI at 3 days and ranged from 1 to 108 days. Patients without AKI had a duration of 0 days. Independent predictors of AKI duration included baseline patient and disease characteristics, and operative and postoperative factors. Prediction for mean duration of AKI was developed using coefficients from the regression model and externally validated the model on 1,219 cardiac surgery patients in a separate cardiac surgery cohort (Translational Research Investigating Biomarker Endpoints-AKI). The c-index was 0.65 ( p p Conclusions We identified and externally validated perioperative predictors of AKI duration. These risk factors will be useful to evaluate a patient's risk for the tempo of recovery from AKI after cardiac surgery and subsequent short and long-term survival. The levels of awareness created by working with these risk factors have implications regarding positive changes in processes of care that have the potential to decrease the incidence and mitigate AKI.
Analysis of coal-oil mixture sedimentation by modified continuity wave theory

Coal-oil mixtures which have the potential to stretch oil usages have been analyzed as to their sedimentation behavior by applying a modification of the continuity wave theory as developed by Kynch. Three coal-oil systems have been studied and have been shown to follow the pseudo continuity wave theory by assigning a degree of agglomeration to the coal particles. With the presence of surfactants, the sedimentation of the mixtures could be similarly analyzed. The general effects of particle size of the coal and temperature of the system have been considered and presented as guidelines for design. On a analyse le comportement a la sedimentation de me, langes de charbon et d'huiles qui potentiellement pourraient conduire a de nouvelles applications des huiles; on a employe, a cette fin, une niodification de la theorie de la continuite, ondulatoire developpee par Kynch. On a etudie trois systemes de charbon-hile et on a trouve qu'ils suivaient la pseudotheorie de la continuite ondulatoire, lorsqu'on affectait un certain degre d'agglomeration aux particules de charbon. On a pu analyser, d'une maniere semblable, la sedimentation des melanges en question en presence d'agents tensio-actifs. On a examine les effets generaux des dimensions des particules de charbon et de la temperature du systeme et que I'on suggere d'utiliser comme guides dans les calcols d'appareillage.
Function of the tetraspanin molecule CD81 in B and T cells

A case of a young girl diagnosed with an antibody deficiency syndrome serves to highlight the role of CD81 in B cell biology. Moreover, this case illustrates a fundamental function of the tetraspanin family, namely their association with partner proteins. Characterization of the patient’s B cells revealed lack of surface CD19 although both of her CD19 alleles were normal. Further analysis determined that her antibody deficiency syndrome was due to a mutation in the CD81 gene, which did not enable expression of CD19 on the surface of the patient’s B cells. Actually, the partnership of CD81 with CD19 and the dependency of CD19 for its trafficking to the cell surface expression were first documented in CD81-deficient mice. CD81 is a widely expressed protein, yet the mutation in the antibody-deficient patient impaired mostly her B cell function. CD81 is required for multiple normal physiological functions, which have been subverted by major human pathogens, such as hepatitis C virus. However, this review will focus on the function of CD81 in cells of the adaptive immune system. Specifically, it will highlight studies focusing on the different roles of CD81 in B and T cells and on its function in B–T cell interactions.
Bus routing in a multi-school system

Abstract This paper describes and evaluates a practical computer based method for translating data concerning (1) the location of each school in a multi-school system to be serviced by a bus fleet, (2) the location of each student to be transported to each school, (3) the time period during which students assigned to each school are to be transported, and (4) the available bus facilities into a set of bus routes which specify school-to-school sequencing of each bus and the stop-to-stop route to be followed in traveling to every school. Each route is designed so that bus capacity and student riding time constraints are satisfied while attempting to minimize both total bus travel time (including running empty) and the number of routes required to service all the stops associated with the school. The mathematical models developed were programmed in FORTRAN IV for use on a CDC 6400 computer and were applied to four schools in a Western New York school district. For each school the routing system determined by these mathematical models was better in terms of number of buses and/or travel time than the system in current use. Furthermore, computation time was very reasonable (from 6.9 sec for 596 students, 37 stops to 136.9 sec for 1097 students, 76 stops).
The T3-induced gene KLF9 regulates oligodendrocyte differentiation and myelin regeneration

Hypothyroidism is a well-described cause of hypomyelination. In addition, thyroid hormone (T3) has recently been shown to enhance remyelination in various animal models of CNS demyelination. What are the ways in which T3 promotes the development and regeneration of healthy myelin? To begin to understand the mechanisms by which T3 drives myelination, we have identified genes regulated specifically by T3 in purified oligodendrocyte precursor cells (OPCs). Among the genes identified by genomic expression analyses were four transcription factors, Kruppel-like factor 9 (KLF9), basic helix-loop-helix family member e22 (BHLHe22), Hairless (Hr), and Albumin D box-binding protein (DBP), all of which were induced in OPCs by both brief and long term exposure to T3. To begin to investigate the role of these genes in myelination, we focused on the most rapidly and robustly induced of these, KLF9, and found it is both necessary and sufficient to promote oligodendrocyte differentiation in vitro. Surprisingly, we found that loss of KLF9 in vivo negligibly affects the formation of CNS myelin during development, but does significantly delay remyelination in cuprizone-induced demyelinated lesions. These experiments indicate that KLF9 is likely a novel integral component of the T3-driven signaling cascade that promotes the regeneration of lost myelin. Future analyses of the roles of KLF9 and other identified T3-induced genes in myelination may lead to novel insights into how to enhance the regeneration of myelin in demyelinating diseases such as multiple sclerosis.
Effect of transmembrane electrical potential and micelle geometry on phospholipid head group conformation.

Abstract Phospholipid head group conformation has been measured in egg phosphatidyl choline vesicles with a transmembrane electrical potential. Using 31 P NMR, the proton source of the 31 P[ 1 H] nuclear Overhauser effect has been determined and the head group conformation shown to be unperturbed by a transmembrane electrical potential near 60 mV. The same technique was used to probe polar head group conformation in lysophosphatidyl choline micelles. The geometric constraints of the micelle structure force the head groups apart, preventing the intermolecular head group interactions found in phosphatidyl choline bilayers.
NASA GRC UAS project communications modeling and simulation development status

The integration of Unmanned Aircraft Systems (UAS) in the National Airspace represents new operational concepts required in civil aviation. These new concepts are evolving as the nation moves toward the Next Generation Air Transportation System (NextGen) under the leadership of the Joint Planning and Development Office (JPDO), and through ongoing work by the Federal Aviation Administration (FAA). The desire and ability to fly UAS in the National Air Space (NAS) in the near term has increased dramatically, and this multi-agency effort to develop and implement a national plan to successfully address the challenges of UAS access to the NAS in a safe and timely manner is well underway. As part of the effort to integrate UAS in the National Airspace, NASA Glenn Research Center is currently involved with providing research into Communications systems and Communication system operations in order to assist with developing requirements for this implementation. In order to provide data and information regarding communication systems performance that will be necessary, NASA GRC is tasked with developing and executing plans for simulations of candidate future UAS command and control communications, in line with architectures and communications technologies being developed and or proposed by NASA and relevant aviation organizations (in particular, RTCA SC-203). The simulations and related analyses will provide insight into the ability of proposed communications technologies and system architectures to enable safe operation of UAS, meeting UAS in the NAS project goals (including performance requirements, scalability, and interoperability), and ultimately leading to a determination of the ability of NextGen communication systems to accommodate UAS. This presentation, compiled by the NASA GRC Modeling and Simulation team, will provide an update to this ongoing effort at NASA GRC as follow-up to the overview of the planned simulation effort presented at ICNS in 2013. The objective of presentation will be to describe the progress made in developing both a NAS-Wide simulation architecture application and the detailed radiocomm system models for this research, and will present interim data and information compiled in the process of developing these simulation capabilities to date.
Zooplankton Trophic State Relationships in Four Alabama–Georgia Reservoirs

ABSTRACT In a 16-month study of four Alabama-Georgia reservoirs, data were collected to relate the trophic condition of the reservoirs to the zooplankton density, biomass, composition, diversity and spatial and temporal distribution within the systems. With the Carlson trophic state index (TSI) and using chlorophyll a concentrations in the calculation, the trophic status of the lakes ranged from a TSI of 39 (mesotrophic) to 65 (highly eutrophic). Total zooplankton density (107 organisms L−1 to 1,590 L−1) and rotifer density (70 L−1 to 1,481 L−1) increased with lake trophy. Crustacean zooplankton density and biomass did not respond as clearly to the trophic gradient During the fall/winter months crustacean zooplankton biomass was greater in the mesotrophic lake than in the three eutrophic lakes. An estimated 36% of the crustacean zooplankton of the mesotrophic lake was greater than 500 urn in total length (TL) compared to a range of 11% to 20% in the three eutrophic lakes. Bosmina longirostris (200 μm to 5...
Ionizing Radiation in Abdominal CT: Unindicated Multiphase Scans Are an Important Source of Medically Unnecessary Exposure

Purpose CT radiation exposure has come under increasing scrutiny because of dramatically increased utilization. Multiphase CT studies (repeated scanning before and after contrast injection) are a potentially important, overlooked source of medically unnecessary radiation because of the dose-multiplier effect of extra phases. The purpose of this study was to determine the frequency of unindicated multiphase scanning and resultant excess radiation exposure in a sample referral population. Methods Abdominal and pelvic CT examinations (n = 500) performed at outside institutions submitted for tertiary interpretation were retrospectively reviewed for (1) the appropriateness of each phase on the basis of clinical indication and ACR Appropriateness Criteria ® and (2) per phase and total radiation effective dose. Results A total of 978 phases were performed in 500 patients; 52.8% (264 of 500) received phases that were not supported by ACR criteria. Overall, 35.8% of phases (350 of 978) were unindicated, most commonly being delayed imaging (272 of 350). The mean overall total radiation effective dose per patient was 25.8 mSv (95% confidence interval, 24.2-27.5 mSv). The mean effective dose for unindicated phases was 13.1 mSv (95% confidence interval, 12.3-14.0 mSv), resulting in a mean excess effective dose of 16.8 mSv (95% confidence interval, 15.5-18.3 mSv) per patient. Unindicated radiation constituted 33.3% of the total radiation effective dose in this population. Radiation effective doses exceeding 50 mSv were found in 21.2% of patients (106 of 500). Conclusions The results of this study suggest that a large proportion of patients undergoing abdominal and pelvic CT scanning receive unindicated additional phases that add substantial excess radiation dose with no associated clinical benefit.
Design of a geostationary microwave precipitation radiometer

The Geostationary Microwave Precipitation Radiometer will be a passive microwave radiometer system to be flown on the NASA Geostationary Earth Observatory. This instrument will provide microwave images for meteorology. It will measure radiation from the Earth and its atmosphere in seven frequency bands from 37 to 220 GHz. The instrument will have a 4 m Cassegrain antenna which will be mechanically scanned to provide images of the Earth in approximately equals 2 hours.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Suppression of renal γ-glutamylcysteine synthetase expression in dietary copper deficiency

Abstract A dietary deficiency of copper (CuD) is associated with a 50–70% and a 2-fold increase in hepatic reduced glutathione (GSH) concentration and synthesis, respectively, which leads to a 50–80% increase in plasma GSH. Moreover, the kidneys of CuD rats remove 40% more GSH from the blood than copper adequate (CuA) rats. These findings have led us to propose that the increase in hepatic synthesis of GSH in CuD rats is accompanied by a comparable increase in the hepatic expression of γ-glytamylcysteine synthetase (γ-GCS), the rate limiting enzyme of glutathione biosynthesis, and that the enhanced uptake of GSH by the kidney would lead to a compensatory decrease in renal γ-GCS expression. In experiment I, male weanling rats (3–4 weeks) were ad libitum fed a CuD (0.5 μg Cu/g) or CuA (5.8 μg/g) diet for 70 days; and in experiment II, male weanling rats were pair-meal fed the CuD or CuA diet for 35 days. In both studies, CuD diet caused a significant increase in hepatic GSH concentration, but hepatic γ-GCS activity and mRNA abundance were unchanged. In contrast, renal GSH concentration was unaffected by the CuD diet. However, renal γ-GCS activity was reduced 40% and this was paralleled by a 50% decrease in γ-GCS mRNA. Moreover, the decrease in renal γ-GCS mRNA was caused by a reduction in renal γ-GCS gene transcription. The results of these studies indicate that the increase in renal uptake of GSH resulting from a dietary Cu deficiency is associated with a compensatory decrease in γ-GCS expression.
Depressed myocardial function after transurethral resection of prostate.

Abstract Cardiovascular physiologic monitoring was undertaken in 12 patients undergoing transurethral resection of the prostate with the aid of flow-directed Swan-Ganz catheter and the Automated Physiologic Profile. Cardiac and pulmonary pressures and physiologic parameters were derived pre- and postoperatively. Resecting time, body temperature, intravenous fluid administered, serum hemoglobin, and sodium also were recorded. Of the 12 patients studied, 66 per cent experienced a drop in their cardiac index as well as their left ventricular function after surgery. Myocardial function curves revealed that 7 patients (58 per cent) had decreased cardiac function, 2 had no change, and 3 had increased function. Four patients with preoperative pulmonary wedge pressures (PA w ) over 9 mm. Hg experienced depressed cardiac function. Three patients were resected for over sixty minutes, and all experienced depressed cardiac function. Vital signs, serum hemoglobin, or serum sodium did not reflect this change. We believe that relative hypervolemia, undetected elevation of pulmonary wedge pressure, and prolonged resection are factors that depress cardiac function and increase the risk of cardiovascular complication in transurethral surgery.
Molecular Mechanics (MM3) Conformational Studies of Cyclic and Acyclic Monochloroalkanes

Molecular mechanics calculations play an important role in modern conformational analysis. Alkyl chlorides are useful organic compounds that have been used as important intermediates and target com...
Direct Acidimetric Analysis of Papaverine in Concentrated Lithium Chloride Solution

Hydrochloric acid was used as the titrant for papaverine base in two different media: (a) 18.5% ethanol and 81.5% 8 M lithium chloride solution, and (b) 10% tetrahydrofuran, 5% ethanol, and 85% 8 M lithium chloride solution. Per cents were calculated on a weight to weight basis. All of the titrations were carried out potentiometrically and the end points were determined by the first derivative method. It was found that bromophenol blue indicator could also be used to determine end points in medium a. The mean per cent recovery for the titrations in medium a, with the end points determined by the first derivative method, was 98.85 with a standard deviation of 0.69. In the same medium, using bromophenol blue for end point determination, the recovery was 99.48 with a standard deviation of 0.96. In medium b, the recovery was 100.02 with a standard deviation of 1.27.
A 106ka paleoclimate record from drill core of the Salar de Atacama, northern Chile

Abstract A 100 m long salt core (SQM #2005) from the Salar de Atacama, northern Chile (23°S, 68°W), a dry lake bed, contains a 106 kyr paleoclimate record of hydrologic balances on the western slopes of the central Andes of South America. Six U-series disequilibrium dates range sequentially from 106.1±6.4 to 5.4±2.7 ka. Based on sedimentary structures and petrographic textures of salts and associated siliciclastic sediments, interpretations of paleoenvironments and net hydrologic balance suggest that relatively wet periods (saline lakes and expanded mudflats) existed in the Salar de Atacama from 75.7 to 60.7 ka and from 53.4 to 15.3 ka, with the wettest perennial lake interval from 26.7 to 16.5 ka. Short relatively wet periods also occurred in the Holocene from 11.4 to 10.2 ka and from 6.2 to 3.5 ka. These wet periods at Salar de Atacama correspond well with other late Pleistocene climate records from the central Andes that are a function of the net hydrologic budget. The Minchin–Tauca lake sequence from Salar de Uyuni, Bolivia, is synchronous with the 53.4–15.3 ka saline lake wet period at Salar de Atacama. The Tauca phase coincided with the wettest perennial lake interval at Salar de Atacama from 26.7 to 16.5 ka. The Coipasa lake phase from Uyuni was probably contemporaneous with the early Holocene wet period at Salar de Atacama from 11.4 to 10.2 ka. The early Holocene wet interval at Salar de Atacama was also synchronous with the maximum Holocene lake levels of the Chilean Altiplano lakes to the east and with grass-rich rodent middens between 11.8 and 10.5 ka in age from the Atacama basin. The lake period at Salar de Atacama between 26.7 and 15.3 ka compares closely with low δ18O values, low anion concentrations and high accumulation rates from the Sajama glacial ice core, southwestern Bolivia between 25 and 15.5 ka. It is concluded that wet and dry phases were synchronous in the central Andean plateau of southwestern Bolivia and along the western flank of the Andes of northern Chile over the past 50 kyr. This region, which today receives its moisture from the Amazon Basin to the east, probably also did so in the past. The wet periods at Salar de Atacama are in phase with January insolation maxima at 15°S at 70, 45, and 20 ka, which suggests that past changes in summer insolation influenced precipitation patterns in the central Andes. However, there are no major wet periods linked to the January insolation maximum at 93 ka and the present-day extremely dry climate in the Atacama Desert is associated with a peak in summer insolation. Therefore there must be other important influences over precipitation in the central Andes which modify the first order insolation controls.
Comprehensive Econometric Microsimulator for Daily Activity-Travel Patterns

The Comprehensive Econometric Microsimulator for Daily Activity-Travel Patterns (CEMDAP) is a microsimulation implementation of an activity-travel modeling system. Given as input various land use, sociodemographic, activity system, and transportation level-of-service attributes, the system provides as output the complete daily activity-travel patterns for each individual in each household of a population. The underlying econometric modeling framework and the software development experience associated with CEMDAP are described. The steps involved in applying CEMDAP to predict activity-travel patterns and to perform policy analysis are also presented. Empirical results obtained from applying the software to the Dallas-Fort Worth area demonstrate that CEMDAP provides a means of analyzing policy impacts in ways that are generally infeasible with the conventional four-stage approach.
Effects of meteorological data thresholding on the quality of urban HPAC predictions of the Joint Urban 2003 field trials

Comparisons of field trial observations with predictions created by the US Defense Threat Reduction Agency's Hazard Prediction and Assessment Capability (HPAC) represent an ongoing effort. Intuitively, one might prefer to include meteorological inputs as close to the release location as possible. During Joint Urban 2003, SODARs measured vertical wind profiles?upwind, within the city centre near the releases, and downwind of Oklahoma City. Low altitude SODAR measurements fell within the urban canopy, while the upper altitude measurements were outside the canopy. In this paper, we demonstrate how the mix of lower altitude and upper altitude wind measurements affects HPAC predictions.
Mapping the Process: An Exemplar of Using Situational Analysis in a Grounded Theory Study

An emerging offshoot of traditional grounded theory methods is situational analysis. This article presents an exemplar of conducting situational analysis within a grounded theory study that focuses on the perceptions of changing family boundaries in the process of leaving an abusive partner. Specifically, I used situational maps to supplement open coding and adapted situational mapping techniques to develop a family-level theory of the process of leaving. The practical and theoretical utility of situational analysis to supplement traditional grounded theory methods is immense, which makes the method highly adaptable to fit the needs of various qualitative research endeavors.
Communication apprehension: Resources for the instructor

This essay provides practical information for those interested in implementing a communication apprehension program. It consists of three parts: Part I is a description of twenty‐four communication programs; Part II is a glossary of various methods used to treat communication apprehension; and Part III is a classified bibliography, arranged by treatment method.
Hysteresis in metal hydrides evaluated from data at constant hydrogen content: Application to palladium-hydrogen

Abstract Equations for the entropy production and free-energy dissipation for iso-hydrogen-content hysteresis are derived for metal hydrides. These values should be equal to those previously derived for isobaric, thermal and isothermal, pressure hysteresis. Experimental data for iso-hydrogen-content hysteresis are obtained for the palladium-hydrogen system, and these results confirm that, to within experimental error, the values of entropy production and free-energy dissipation are equal to the values from the other two methods of measuring hysteresis.
Optimization of supercritical carbon dioxide extraction for polychlorinated biphenyls and chlorinated benzenes from sediments

Abstract A method for the simultaneous extraction of polychlorinated biphenyls (PCBs) and chlorinated benzenes in sediments using supercritical fluid extraction (SFE) technique was developed. The best recovery of the above chlorinated pollutants was obtained by using non-modified carbon dioxide at 35 MPa and an extraction temperature of 100°C with a sediment moisture content in the 11 to 50% range. Cleanup of SFE extract was performed on a miniature Florisil column followed by sulfur removal with mercury. PCB levels were quantitated by a mixture of selected PCB congeners using a mass-selective detector so that the level of each PCB homologue series as well as the total PCB concentration in the sample extract could be evaluated. Under the optimized conditions, an extraction time of only 21 minutes was needed to produce PCB results comparable to a 7-h Soxhlet extraction. Meanwhile, the SFE recovery of chlorinated benzenes was up to 50% higher than for the Soxhlet results due to lower evaporative losses in the former procedure.
TECHNIQUE FOR THYROIDECTOMY IN THE PIGEON AND THE EARLY EFFECT OF THYROID REMOVAL ON HEAT PRODUCTION

ALTHOUGH thyroidectomy in fowl (–7), geese (8), ducks (1) and pigeons (9, 10) has been reported, the descriptions of the technique for these operations A. JA. have been found by us to be quite inadequate. The pigeon has many advantages for the study of calcemia, lipemia, and certain aspects of carbohydrate and fat metabolism, but recognition of the role of the thyroid in these processes has been retarded by the difficulty of obtaining large numbers of thyroidectomised birds with unimpaired digestive apparatus. The technique here described has been found to be satisfactory in this respect. White Carneau pigeons about 2 months old have been used in this study. The bird is fastened on its back to the operating board by rubber strips cut from automobile inner tubes. One strip on each side holds each wing and a strip across the end holds the feet in place.
MOVPE growth of GaInAsSb

Ga1−xInxAs1−ySby alloys have been grown by metalorganic vapor phase epitaxy (MOVPE) using trimethyl compounds of Ga In, As, and Sb (TMGa, TMIn, TMAs, and TMSb) plus AsH3 in an atmospheric pressure, horizontal, infrared heated reactor.For the first time, alloys near the center of the region of solid immiscibility have been grown. Alloys with room temperature band gaps of between 0.32 and 0.74 eV (1.7 to 3.9μm) have been grown on InP, InAs and GaSb substrates. The larger band gap alloys, grown on either InP or Gasb substrates, could be grown at temperatures between 580 and 600°C. For the smaller band gap alloys grown on InAs substrates lower temperatures of 480 to 500°C were necessary to avois melting of the layer. These low temperatures caused a reduction of the Ga distribution coefficient from unity value at temperatures of 550°C, to 0.05 at 500°C. The presence of TMSb in the system caused a further reduction in Ga incorporation. The Sb distribution coefficient at 500°C was 0.17. The low temperature photoluminescence of the quaternary alloys routinely consisted of a single peak characteristic of the band gap. The spectral half-width was found to increase for the more metastable alloys. This may indicate the occurence of a significant amount of compositional clustering during growth.
Message caching for local and global resource optimization in shared virtual environments

The use of Shared Virtual Environments is growing in areas such as multi-player video games, military and industrial training, and collaborative design and engineering. As a result, different mixes of computing power and graphics capabilities of the participating computers arise naturally as the variety of people/organizations sharing a virtual environment grows. This paper presents an adaptive mechanism to reduce bandwidth usage and to optimize the use of computing resources of heterogeneous computers mixes utilized in a shared virtual environment. The mechanism is based on caching of both outgoing- and incoming-messages. We also report the results of implementing the proposed scheme in a simple shared virtual environment.
EXCITED-STATE PROPERTIES OF THYMIDINE AND THEIR RELEVANCE TO ITS HETEROGENEOUS EMISSION IN DOUBLE-STRANDED DNA

Published results on synthetic polynucleotides point to T as the major emitting fluorophore in DNA. We have reported also that the bases of the nonalternating polynucleotide poly(dA).poly(dT), in which T was selectively excited, undergo large-amplitude motions on the picosecond-nanosecond time scales (S. Georghiou et al., Biophys. J. 70, 1909-1922, 1996). In that study, the fluorescence decay profile of the T bases of this polynucleotide was found to contain a number of components; these may be considered to be the result of the motions of the bases that give rise to a distribution of stacked geometries of varying rigidity as well as dispersion and polar interactions. Here, we report the results of a study that we have undertaken in order to test this hypothesis. To this effect, we have studied the photophysical properties of thymidine (1) in aqueous buffer and in a number of organic solvents and (2) in aqueous sucrose solutions of viscosity extending to 149 cP. The results suggest that the fluorescence quantum yield decreases with an increase in the polarizability of the solvent, whereas it increases with an increase in the solvent polarity (on the basis of the empirical parameter of solvent polarity ETN) or viscosity. These findings suggest the following for the photophysical properties of the T bases in DNA: (1) Base stacking results in two antagonistic effects, namely it causes a reduction in fluorescence as a result of dispersion interactions and an enhancement as a result of a reduction in the motions of the bases and (2) exposure of the bases to the aqueous environment results in fluorescence enhancement.
The exchange paradigm: Where to now?

This essay restates the main conclusions of “Value and Exchange,” discusses three possible directions of research that flow from it, and evaluates their likely impact on the economics profession. The three directions are (1) the application of the distinction between value paradigm and exchange paradigm to the elucidation of the history of economic thought, (2) formal theorizing within the framework of the exchange paradigm, and (3) empirical work informed by the insights of the exchange paradigm.
Research Note---The Halo Effect in Multicomponent Ratings and Its Implications for Recommender Systems: The Case of Yahoo! Movies

Collaborative filtering algorithms learn from the ratings of a group of users on a set of items to find personalized recommendations for each user. Traditionally they have been designed to work with one-dimensional ratings. With interest growing in recommendations based on multiple aspects of items, we present an algorithm for using multicomponent rating data. The presented mixture model-based algorithm uses the component rating dependency structure discovered by a structure learning algorithm. The structure is supported by the psychometric literature on the halo effect. This algorithm is compared with a set of model-based and instance-based algorithms for single-component ratings and their variations for multicomponent ratings. We evaluate the algorithms using data from Yahoo! Movies. Use of multiple components leads to significant improvements in recommendations. However, we find that the choice of algorithm depends on the sparsity of the training data. It also depends on whether the task of the algorithm is to accurately predict ratings or to retrieve relevant items. In our experiments a model-based multicomponent rating algorithm is able to better retrieve items when training data are sparse. However, if the training data are not sparse, or if we are trying to predict the rating values accurately, then the instance-based multicomponent rating collaborative filtering algorithms perform better. Beyond generating recommendations we show that the proposed model can fill in missing rating components. Theories in psychometric literature and the empirical evidence suggest that rating specific aspects of a subject is difficult. Hence, filling in the missing component values leads to the possibility of a rater support system to facilitate gathering of multicomponent ratings.
Electron paramagnetic resonance studies of membrane proteins in hepatic microsomes.

Abstract Hepatic microsomal membranes, prepared under various conditions that yield either ‘intact’ or ‘disrupted’ microsomal vesicles, have been labeled via the sulfhydryl groups of intrinsic membrane proteins using nitroxide analogs of N- ethylmaleimide . Electron paramagnetic resonance spectra revealed the presence of two dominant classes of bound label corresponding to differing degrees of immobilization, the ratio of which were quantitated using a parameter designated the ‘ W/S ’ ratio. For latent microsomes, the value of this parameter was determined to be 0.65 ± 0.02 and was influenced by factors such as label/protein ratio, incubation period, nitroxide structure, temperature and pH. The W/S ratio was also sensitive to the degree of membrane integrity as revealed by the latency of mannose 6-phosphate activity of glucose-6-phosphohydrolase. In addition, membrane disruption resulted in a corresponding decrease in the order parameter for nitroxide-labeled fatty acids intercalated within the lipid bilayer. The W/S ratio was observed to be dependent upon the method of microsome preparation yielding values of 1.02 ± 0.02 for ‘hypertonically disrupted’ vesicles and 1.28 ± 0.02 for ‘mechanically disrupted’ vesicles. Microsomal marker enzymes such as cytochrome P-450 and FAD-containing monooxygenase retained significant levels of functionally following nitroxide incorporation.
The surgical management of congenital heart disease in the adult

There are an increasing number of adults with congenital heart disease due to greater success with palliative and corrective operations, along with improvements in the medical management of operated and unoperated patients. There are approximately 1 million adult corrected, palliated or uncorrected congenital heart patients; which is estimated to increase by 5% per year w1x The growing importance of this area of cardiology and cardiac surgery is reflected by subspecialty training and education, such as the recent 32nd Bethesda Conference on ‘The Care of Adults with Congenital Heart Disease’ w2x. Surgery on adult congenital heart patients is unique in that the surgical and perioperative care team (cardiology and critical care in particular) should have a thorough understanding of the particular anatomy and physiology involved. In our own experience 260 patients over the age of 18 years have undergone an operation to correct a congenital heart defect over the past 5 years (Table 1). Table 1 represents roughly 15% of our overall operated congenital heart population. These lesions range widely in complexity and include aortic valve disease that has close similarity with acquired heart disease and management to the more complex single ventricle physiology that requires a dedicated congenital heart team. The types of cardiac lesions encountered in adult patients, such as those listed in Table 1 can be divided into lesions by increasing complexity and likelihood of reaching adult age and requiring surgery. Previously operated individuals who require further surgery represent the largest group by far. Need for further intervention is based on a number of factors that include electrophysiologic, valvular (native), prosthetic materials (valves, patches and conduits), myocardial, vascular and neurologic w3x.
The Mechanisms of the Inactivation of Human Alpha-1-Proteinase Inhibitor by Gas-Phase Cigarette Smoke

Abstract Cigarette smoke, either directly or indirectly, causes alpha-1-proteinase inhibitor (a1PI) to lose elastase inhibitory capacity (EIC), leaving lung connective tissues susceptible to proteolytic degradation. This paper discusses possible mechanisms for inactivation by cigarette smoke (CS) and by a model system [NO, isoprene, and air] that duplicates much of CS free radical chemistry. Inactivation of a1PI by either CS or the model is biphasic; a fast inactivation is followed by a slower one. With pre-prepared extracts, only the slow inactivation is observed. Apparently short-lived species in the smoke itself and the model system cause the fast inactivation; they may be peroxynitrates, which form in smoke from nitrogen dioxide and peroxyl radicals. The slower inactivation appears to involve hydrogen peroxide and/or organic hydroperoxides or species produced by them. Incubation of a1PI with linoleic acid produces a slow loss of EIC, prevented by the presence of vitamin E, which supports the hypothesis of a route involving lipid hydroperoxides. Protection of a1PI by various types of compounds shows that unprotonated amines and amino acids protect, but the protonated or acylated compounds do not. Ascorbate and glutathione provide the strongest protection.
Structural materials underpinning functional materials: teaching old dogs new tricks

‘Structural’ polymers are finding new applications underpinning new technology developments based on functional polymers. This paper discusses the use of polyester films as base substrates for flexible electronic applications based on conjugated polymers and low-temperature hydrogenated amorphous silica processing, and discusses the challenges involved in successfully developing substrates ‘fit for purpose’. Copyright © 2008 Society of Chemical Industry
Difference in quality of life in women with urge urinary incontinence compared to women with stress urinary incontinence

Introduction We evaluated whether women with urge urinary incontinence (UUI) have lower quality of life (QOL) than women with other forms of urinary incontinence.
Multielement analysis of Nigerian chewing sticks by instrumental neutron activation analysis

In Nigeria, various parts of various species of native plants have long been used for dental hygiene, with reportedly considerable effectiveness. These materials are known as “chewing sticks”. This study was an effort to ascertain whether any unusual trace element concentrations might be present in Nigerian chewing sticks. Results are presented for 17 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Mn, Fe, Co, Zn, Br, Cs, La, Sm, Au) detected and measured in 12 species of such plants, via instrumental thermal-neutron activation analysis.