cssi/SciSciGPT-SciSciNet huggingface dataset:
A mathematical model of the deposition rate and layer height during electrochemical additive manufacturing

Electrochemical additive manufacturing (ECAM) is a novel non-thermal metal additive manufacturing technology. The layer height is an important parameter in additive manufacturing processes which determines the resolution and quality of the parts manufactured. The modeling of the rate of deposition enables the prediction of the layer size and time of deposition for a particular feature. The developed model takes the electrical process parameters and the horizontal scan speed as inputs and gives the rate of deposition and deposited layer height as the output. The current density was calculated based on an existing model considering ion transport and electrode kinetics. The predicted deposition rates were validated with experimental findings. It was found that the pulsed voltage with a 75% duty cycle had the highest deposition rate. While the deposition rates varied between 1 and 3 μm/s, the scan speed was found to be between 0.1 to 2 mm/s for a diameter 250-μm tool. The scan speed had a lower limit for each interelectrode gap below which a possibility of short-circuiting exists. The influence of the pulse duty cycle on the layer height reduces at larger interelectrode gaps.
SAFETY AND EFFICACY OF MITRACLIP IN FUNCTIONAL VERSUS DEGENERATIVE MITRAL REGURGITATION: A META-ANALYSIS OF OBSERVATIONAL STUDIES

The utility of percutaneous mitral valve repair (MitraClip) in functional mitral regurgitation (FMR) is unknown. A systematic electronic search of the scientific literature was performed in PubMed, EMBASE, Google Scholar and ClinicalTrials. gov. Studies comparing safety and efficacy of MitraClip in
Optical Stability of 1,1'-Binaphthyl Derivatives.

The racemization process of various 1,1′-binaphthyl derivatives is studied by quantum calculations. The preferred racemization pathway passes through a transition state belonging to the Ci symmetry...
Demonstration of opiate receptor sub-types in vivo.

Abstract Using a modification of the rapid membrane filtration technique and various opiate tracers, we have developed in vivo labeling techniques that differentiate three, and possibly four, opiate receptor sub-types in intact rats. [3H]Etorphine appears to label a subset of receptors (15–20 pmol/g brain) labeled by [3H]diprenorphine (25–30 pmol/g brain), and [3H]naloxone labeled an additional binding site population that is not labeled by [3H]diprenorphine.
Carbon negative oil: A pathway for CO2 emission reduction goals

Abstract There is a carbon sequestration benefit to the ethanol manufacturing process if the CO2 that is created in the fermentation process in an ethanol plant is geologically stored by an enhanced oil recovery (EOR) project. In order to recover one barrel of oil using CO2-EOR, an equal or greater amount of CO2 must be sequestered in order to recover the oil (∼1.0–2.5 tonnes of CO2 are stored for each tonne of CO2 emissions resulting from combustion of the recovered oil). The oil produced from a CO2-EOR sequestration project is therefore either carbon neutral or carbon negative if the CO2 is sourced from the fermentation emissions from an ethanol plant. The 40.3 million metric tonnes of CO2 fermentation emissions vented during the production of 53.4 million liters of ethanol per year in the U.S. could result in production of 40–100 million barrels of carbon negative oil annually. A carbon value chain (CVC) based on carbon credits could incentivize the construction of a CCS infrastructure in the United States that begins with the capture of corn ethanol CO2 fermentation emissions. Utilization of biofuel fermentation emissions worldwide in bio-CO2-EOR sequestration projects would help achieve global CO2 emission reduction goals.
Design of Capacitive Sensor for Phase Concentration Measurement in Two-phase Flow

Concave capacitive sensors are widely applied for phase concentration measurement in two-phase flow. Fringing electric fields exist between any two concave capacitance electrodes of finite length and the additional capacitance these fields add is not easily accounted for. It is important to account for fringe effect in many capacitive sensing applications in order to ensure accurate measurement results. In this paper, a capacitive sensor with axis and radial grounded guard electrodes is proposed. The performance of the sensor with and without guard electrodes in term of fringe effect and output linearity is investigated. For the determination of the optimal structure of the capacitive sensor, numerical simulation and response surface method are adopted. Numerical simulation and static phantom experiments show the effectiveness of the proposed capacitive sensor which allowed a significant reduction of the fringe effect and good linearity and good sensing field homogeneity.
Accuracy of liver ablation zone prediction in a single 2450 MHz 100 Watt generator model microwave ablation system: An in human study

Abstract Purpose To compare manufacturer provided predictions and realized ablation dimensions in the liver using one 2450 MHz 100 Watt generator model microwave ablation (MWA) system. Materials and method Between 1/1/2015 and 2/1/2018, MWAs were performed in 86 patients who underwent a total of 103 MWAs with a single MWA system. There were 64 men and 22 women with a mean age of 63.9 ± 9.9 (SD) years (range: 30–88 years). Demographic, procedural, and outcomes data was recorded. The manufacturer predicted ablation zone sizes in three dimensions (anterior-posterior [AP], transverse [TR], and cranial caudal [CC]) were recorded and then compared to the actual ablation zone sizes at one month follow-up imaging. Results MWAs were most commonly performed to treat hepatocellular carcinoma (92/103, 89.3%). Dividing the actual ablation size by the manufacturer prediction in the AP, TR, and CC directions resulted in a mean of 88.3 ± 20.6 (SD) % (range: 33.3–156.4%), 80.2 ± 26.5 (SD) % (range: 29.6–182.9%), and 86.7 ± 25.1 (SD) % (range: 37–186.1%), respectively. The realized AP direction was statistically closer to the manufacturer prediction than the TR (P Conclusions This 2450 MHz 100 Watt generator MWA system manufacturer provided model fairly accurately predicts ablation zone dimensions, but tends to over predict realized dimensions in this mainly hepatocellular carcinoma, and therefore cirrhotic, cohort. The TR is the most inaccurately predicted dimension and manufacturer predictions appear to be best in the 100 W setting, important aspects for interventionalists to consider during ablation planning and execution.
Survival advantage of chemoradiotherapy in anaplastic thyroid carcinoma: Propensity score matched analysis with multiple subgroups

BACKGROUND We compared overall survival (OS) between radiation therapy (RT) and chemoradiotherapy (CRT) in patients with anaplastic thyroid carcinoma (ATC) using a large database. METHODS The National Cancer Data Base was queried for ATC patients diagnosed between 2004 and 2013 who received RT or CRT. Groups were balanced by propensity score matching (PSM) on nine relevant variables. OS was also examined in five paired subgroups given known patient heterogeneity. RESULTS Of 858 total patients, 575 received CRT and 283 received RT. CRT was associated with decreased risk of death (hazard ratio [HR] 0.66, P < .001), 1-year OS 25.5% vs 14.3%. A survival advantage to CRT was seen using PSM cohorts (HR 0.75, P = .006). Those receiving definitive surgery saw the greatest benefit to CRT over RT (HR 0.65, P = .009), 1-year OS 39.6% vs 20.4%. CONCLUSIONS CRT is associated with decreased risk of death in ATC; the magnitude of CRT vs RT benefit varied by subgroup.
Long-term follow-up of all-polyethylene tibial components when used for oncological endoprosthetic reconstruction.

Aims We aimed to examine the long-term mechanical survivorship, describe the modes of all-cause failure, and identify risk factors for mechanical failure of all-polyethylene tibial components in en...
Minding the Empagran Gap

The Supreme Court has made clear how it expects courts to analyze the presumption against extraterritoriality as applied to federal statutes. But it has not provided similarly clear guidance for what comes after: how courts should determine the reach of statutes that do rebut the presumption against extraterritoriality? The closest the Court has come to an answer is F. Hoffman-La Roche Ltd. v. Empagran S.A., in which the Court explained that it “ordinarily construes ambiguous statutes to avoid unreasonable interference with the sovereign authority of other nations.” The Court was perhaps purposefully vague, however, when it came to what “unreasonable interference” might mean, nor have the lower courts settled on an answer. Reflecting this uncertainty, the new Restatement (Fourth) of the Foreign Relations Law of the United States acknowledges that there may be a limit on the reach of an extraterritorial statute without settling on how that limit should be determined (beyond categorizing it as an act of statutory interpretation). This essay explores the Empagran “gap” in the Court’s—and thus the Restatement (Fourth)’s—treatment of extraterritorial federal statutes. It argues that the Restatement (Fourth)’s collection of statutory interpretation tools is insufficient to address fully the reach of extraterritorial federal statutes. Further, the current indeterminacy of this analysis carries costs in terms of possible doctrinal distortion. What the gap calls for is a conflicts of law analysis focused on the question of priority, which is effectively what the lower courts have been doing. But explicitly adopting a conflicts of law approach raises its own challenges, ones that are potentially surmountable but will require significant work. The essay thus concludes on an imperfect but pragmatic note, mirroring the Restatement (Fourth)’s embrace of constructive ambiguity to suggest how the gap might be narrowed, even if not completely resolved.
Prevalence of lateral epicondylosis in veteran manual wheelchair users participating in adaptive sports.

Objective: Determine the prevalence of lateral epicondylosis (LE) of the dominant elbow in manual wheelchair users based on ultrasound assessment and physical exam. Design: Prospective, cross-secti...
Enabling In-SRAM Pattern Processing With Low-Overhead Reporting Architecture

The demand for accelerated pattern matching has motivated several recent in-memory accelerator architectures for automata processing, which is an efficient computation model for sophisticated pattern matching. Existing in-memory pattern matching architectures focus on accelerating the pattern matching kernel, but either fail to support a practical reporting solution or overlook the reporting stage. However, gathering and processing the reports can be the main bottleneck, especially for applications with high reporting frequency. Moreover, all the existing in-memory architectures work with a fixed processing rate (mostly 8 bits per cycle), and they do not adjust the input consumption rate based on the properties of the applications, which can lead to throughput and capacity loss. To address these issues, we present Sunder, an in-SRAM pattern matching architecture to processes a reconfigurable number of nibbles (4-bit symbols) in parallel, instead of fixed-rate processing, by adopting an algorithm/architecture methodology to perform hardware-award transformations. The key insight of our work is that transforming the commonly-used 8-bit processing to nibble-processing reduces required hardware resources (i.e., number of used memory rows) exponentially and achieves higher information density. This frees up space for storing reporting data in-place, which significantly eliminates host communication and reporting overhead. As a result, Sunder enables a low-overhead, energy-efficient, and high-performance in-memory pattern matching solution. Our results confirm that Sunder reporting architecture has zero performance overhead for 95% of the applications and incurs only 2% additional hardware overhead compared to the state-of-the-art solutions with no support for the reporting stage.
SARS-CoV-2 infection increases tacrolimus concentrations in solid-organ transplant recipients.

Calcineurin inhibitors (CNI) are narrow therapeutic index medications, with drug concentrations altered by factors such as drug-drug interactions, clinical symptoms including diarrhea, and hepatic dysfunction. Supratherapeutic CNI concentrations can produce a myriad of toxicities, the most worrisome of which are renal injury and seizures.
State-Level Variation in Waitlist Mortality and Transplant Outcomes Among Patients Listed for Heart Transplantation in the US From 2011 to 2016

Importance Little is known about geographic variation in the outcomes of adult patients listed for heart transplantation in the US. Identifying the patterns and extent of variation is important to minimize disparity in outcomes. Objective To evaluate the geographic patterns, extent, and factors associated with state-level variation in outcomes of adult patients listed for heart transplantation in the US. Design, Setting, and Participants This nationwide retrospective cohort study used data from the United Network for Organ Sharing database to identify adult patients listed for heart transplantation at status 1A between January 1, 2011, and December 31, 2016. Patients were followed up until March 31, 2018. Data were analyzed from November 1, 2019, to September 19, 2020. Main Outcomes and Measures The study evaluated state-level variation in the 3 main organ transplant measures: waitlist mortality, transplant rate, and risk-adjusted 1-year graft survival. The rate of death while on the waitlist and the rate of transplant were calculated for each state per 1000 waitlist person-days listed at status 1A over the study period. Risk-adjusted 1-year graft survival was calculated based on the Scientific Registry of Transplant Recipients risk-adjustment model. State-level variation in each outcome measure was evaluated via multivariable-adjusted models. Results Across 50 states and the District of Columbia, a total of 15 036 patients (mean [SD] age, 52 [13] years; 3531 women [24%]; 9626 White [64%]) were listed at status 1A for adult heart transplantation between 2011 and 2016. Of those, 2146 patients (14.3%) died while on the waitlist, and 10 982 patients (73.0%) received transplants. Among those who received transplants, the median time on the waitlist was 31 days (interquartile range, 13-61 days). State-level outcomes ranged from 1.0 to 7.8 deaths per 1000 waitlist person-days for waitlist mortality, 5.6 to 34.5 transplants per 1000 waitlist person-days for transplant rate, and 87% to 92% for risk-adjusted 1-year graft survival. In a comparison of the highest and lowest quartiles, significant state-level variation was found in waitlist mortality (hazard ratio [HR], 1.53; 95% CI, 1.27-1.86), transplant rate (HR, 1.57; 95% CI, 1.31-1.87), and 1-year graft survival (odds ratio, 2.07; 95% CI, 1.64-2.62). Conclusions and Relevance The study’s findings indicate that significant state-level variation exists in the outcomes of patients listed for heart transplantation in the US. Identifying and addressing the factors associated with these geographic variations in outcomes is important to ensure a fair allocation system.
Evaluating livetrapping and camera-based indices of small-mammal density

Density estimates are integral to wildlife management, but they can be costly to obtain. Indices of density may provide efficient alternatives, but calibration is needed to ensure the indices accur...
A Bias-Flip Interface and Dual-Input DC-DC Converter for Piezoelectric and RF Energy Harvesting

Energy harvesting converts nonelectrical energy into electrical energy to power low-power integrated circuits for the Internet of Things and wearable devices. This paper presents an energy harvesting power management integrated circuit implemented in 180 nm SOI CMOS. The proposed system improves piezoelectric energy harvesting power extraction by using an improved bias-flip interface and increases power output by simultaneously scavenging multiple energy sources using a dual-input buck-boost converter. The implemented bias-flip interface, when using a 2.2 mH inductor and 6 switched capacitors, offers a bias-flip efficiency up to 95.1%. At 113.4 Hz vibration excitation of 0.6 g, the proposed interface provides a 7.62×, 2.47×, and 1.22× power extraction improvement when compared to an ideal full-bridge rectifier, and synchronized switch harvesting on inductor (SSHI) and on capacitor (SSHC) circuits, respectively. Furthermore, the bias-flip inductor is shared with the integrated dual-input DC-DC converter simultaneously scavenging high­voltage piezoelectric and low-voltage RF energy to increase output power and improve environmental adaptability of the system.
Clinical outcomes in revision lumbar spine fusions: an observational cohort study

OBJECTIVE The authors compared primary lumbar spine fusions with revision fusions by using patient Oswestry Disability Index (ODI) scores to evaluate the impact of the North American Spine Society (NASS) evidence-based medicine (EBM) lumbar fusion indications on patient-reported outcome measures of revision surgeries. METHODS This study was a retrospective analysis of a prospective observational cohort of patients who underwent elective lumbar fusion between January 2018 and December 2019 at a single quaternary spine surgery service and had a minimum of 6 months of follow-up. A prospective quality improvement database was constructed that included the data from all elective lumbar spine surgeries, which were categorized prospectively as primary or revision surgeries and EBM-concordant or EBM-discordant revision surgeries based on the NASS coverage EBM policy. In total, 309 patients who met the inclusion criteria were included in the study. The ODIs of all groups (primary, revision, revision EBM concordant, and revision EBM discordant) were statistically compared. Differences in frequencies between cohorts were evaluated using chi-square and Fisher's exact tests. The unpaired 2-tailed Student t-test and the Mann-Whitney U-test for nonparametric data were used to compare continuous variables. Logistic regression was performed to determine the associations between independent variables (surgery status and NASS criteria indications) and functional outcomes. RESULTS Primary lumbar fusions were significantly associated with improved functional outcomes compared with revisions, as evidenced by ODI scores (OR 1.85, 95% CI 1.16-2.95 to achieve a minimal clinically important difference, p = 0.01). The percentage of patients whose functional status had declined at the 6-month postoperative evaluation was significantly higher in patients who had undergone a revision surgery than in those who underwent a primary surgery (23% vs 12.3%, respectively). An increase in ODI score, indicating worse clinical outcome after surgery, was greater in patients who underwent revision procedures (OR 2.14, 95% CI 1.17-3.91, p = 0.0014). Patients who underwent EBM-concordant revision surgery had significantly improved mean ODI scores compared with those who underwent EBM-discordant revision surgery (7.02 ± 5.57 vs -4.6 ± 6.54, p < 0.01). CONCLUSIONS The results of this prospective quality improvement program investigation illustrate that outcomes of primary lumbar fusions were superior to outcomes of revisions. However, revision procedures that met EBM guidelines were associated with greater improvements in ODI scores, which indicates that the use of defined EBM guideline criteria for reoperation can improve clinical outcomes of revision lumbar fusions.
Economic modeling of fault tolerant flight control systems in commercial applications

This paper describes the current development of a comprehensive model which will supply the assessment and analysis capability to investigate the economic viability of Fault Tolerant Flight Control Systems (FTFCS) for commercial aircraft of the 1990's and beyond. An introduction to the unique attributes of fault tolerance and how they will influence aircraft operations and consequent airline costs and benefits is presented. Specific modeling issues and elements necessary for accurate assessment of all costs affected by ownership and operation of FTFCS are delineated. Trade-off factors are presented, aimed at exposing economically optimal realizations of system implementations, resource allocation, and operating policies. A trade-off example is furnished to graphically display some of the analysis capabilities of the comprehensive simulation model now being developed.
The Behavior of Moderately and Severely Retarded Persons

Publisher Summary This chapter discusses the behavior of retardates who score below IQ 50 on a standardized test. Severely retarded persons, especially those in residential centers, most frequently do not dress themselves, are not totally toilet trained, and in many instances do not even feed themselves. Their social reactions to people vary a great deal. The chapter provides the solution of practical problems through the use of operant techniques. The social reactions of moderately retarded children to adults are somewhat more varied than those of the severely retarded, and they usually exhibit a more extensive verbal repertoire. In cases where operant techniques are applied, the reported results are encouraging. Thus, it may be expected that these advances will lead to the development of training and educational programs, which one day will allow these people to live in and contribute to the noninstitutional community. The extent to which such a goal is accomplished depends primarily on the ingenuity and effort of interested workers.
Abstract P244: Combined Measures of Total and Abdominal Adiposity and the Likelihood of Subclinical Myocardial Damage

Background: Obesity has been independently associated with subclinical myocardial damage. Both body mass index (BMI) and waist circumference (WC) are recommended for cardiovascular risk assessment, and they provide complementary information about heart failure (HF) risk. However, their combined relationship with subclinical myocardial damage is presently unknown. Hypothesis: We hypothesized that high measures of both BMI and WC would have the strongest association with subclinical myocardial damage, as indexed by a high-sensitivity assay for cardiac troponin T (hs-cTnT). Methods: We performed a cross-sectional analysis of 9,507 participants at ARIC Visit 4 (1996-99). We excluded individuals with prior cardiovascular disease, with BMI 14 ng/L) measured at Visit 4, after adjustment for confounding variables. R...
Commercial Buildings as Clean Domestic Energy Assets by 2025? DOE’s Roadmap for a Net-zero Energy Built Environment

ABSTRACT A net-zero energy building (NZEB) is a highly energy-efficient residential or commercial building that, over the course of a year, uses renewable technology to produce as much energy as it consumes from the grid. In the commercial sector, building owners and tenants stand to realize attractive returns on their NZEB investments while reducing their carbon footprints. Considering that buildings are our nation's highest energy-consuming and carbon-emitting sector, NZEBs have a vital role in reducing U.S. energy demand and greenhouse gas emissions (GHGs). This article outlines the U.S. Department of Energy's (DOE's) goals for the energy use by our nation's commercial buildings, the research and development (R&D) efforts most critical to realizing NZEBs, and DOE's strategy of collaborating with the private sector to speed the arrival of NZEBs in the marketplace.
Feasibility Study of a Compact Ignition Tokamak Based upon GyroBohm Scaling Physics

The design of a reduced size (R = 4.45 m, B{sub T} = 5.04 T) ignition tokamak (Q = {infinity}) with superconducting coils using a standard ELMing H-mode plasma appears to be feasible. This effective size (B{sub T}{sup 2/3}R{sup 5/6}) is smaller than current proposals for Q = 10 burning (D-T) plasma experiments. The good confinement required for ignition with this small effective size is obtained by operating along a gyroBohm scaling path starting from the existing tokamak database at high beta ({beta} = 4.1%) so that the loss power from core transport exceeds the H-mode threshold power. Using a design that can achieve a high normalized current (I{sub p} /aB{sub T} = 1.63) also helps to decrease the size of the machine. The design of this relatively compact ignition tokamak satisfies reasonable engineering constraints on the superconducting toroidal field coils and central solenoid, and allows for a sufficiently long burn time for the plasma current to relax to its final state.
Rapid, single-tube method for quantitative preparation and analysis of RNA and DNA in samples as small as one cell

Current methods for accurate quantification of nucleic acids typically begin with a template preparation step in which DNA and/or RNA are freed of bound proteins and are then purified. Isolation of RNA is particularly challenging because this molecule is sensitive to elevated temperatures and is degraded by RNases, which therefore have to be immediately inactivated upon cell lysis. Many protocols for nucleic acids purification, reverse transcription of RNA and/or amplification of DNA require repeated transfers from tube to tube and other manipulations during which materials may be lost. This paper introduces a novel and highly reliable single-tube method for rapid cell lysis, followed by quantitative preparation and analysis of both RNA and/or DNA molecules in small samples. In contrast to previous approaches, this procedure allows all steps to be carried out by sequential dilution in a single tube, without chemical extraction or binding to a matrix. We demonstrate the utility of this method by quantification of four genes, Xist, Sry and the two heat-inducible hsp70i (hsp70.1 and hsp70.3), as well as their RNA transcripts in single mouse embryos and in isolated blastomeres. This method virtually eliminates losses of nucleic acids and is sensitive and accurate down to single molecules.
Cross-spectrum symbol synchronization

A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.
Comparative analysis of unaided emmetropic and unaided noncorrected myopic underwater visual acuity.

Abstract This study was undertaken to explore the effect of an underwater environment on unaided emmetropic and unaided noncorrected myopic visual acuity. University of Oregon men and women students (N = 60) having a swimming ability of intermediate or better volunteered for the study. A lighted Snellen letter chart was used to classify 30 subjects as emmetropes with a visual acuity of 20/20 or better and 30 subjects as myopes with a visual acuity of 20/200 or worse. Each of the 30 subjects in both classifications was randomly assigned to treatments of either bright or dim target illumination and one of three solutions (hypotonic, isotonic, and hypertonic). The measurement of unaided underwater visual acuity was determined by means of an adapted Landolt broken circle target and an instrument designed to measure the distance at which an individual can perceive the direction of the break in the circle. The results indicated that (1) myopes (20/200 or worse) can, on the average, see significantly (.055 level...
A priori estimates of smoothness of solutions to difference Bellman equations with linear and quasi-linear operators

A priori estimates for finite-difference approximations for the first and second-order derivatives are obtained for solutions of parabolic equations described in the title.
Risk of exogenous estrogen therapy and endometrial cancer

A retrospective study was carried out on 431 patients with endometrial cancer and 431 control subjects matched as to age, race, and parity. They were seen at Duke University Medical Center from 1940 to 1975. The study was performed in order to evaluate the risk of exogenous estrogen therapy and the development of adenocarcinoma of the endometrium. The overall risk was 2.38, with certain subgroups demonstrating different degrees of risk. Increased risk was associated with estrogen therapy of longer than 5 years' duration in white patients. The risk also was confined to Stage I, grade 1 lesions and more superficial myometrial invasion. Five-year survival for patients who used estrogen replacement and had Stage I, grade 1 lesions was 94.7%. The risks associated with exogenous estrogens are real but should be considered in a risk/benefit context when prescribing for the needs of an individual patient.
Bowtie filters for dedicated breast CT: Analysis of bowtie filter material selection

Purpose: For a given bowtie filter design, both the selection of material and the physical design control the energy fluence, and consequently the dose distribution, in the object. Using three previously described bowtie filter designs, the goal of this work is to demonstrate the effect that different materials have on the bowtie filter performance measures. Methods: Three bowtie filter designs that compensate for one or more aspects of the beam-modifying effects due to the differences in path length in a projection have been designed. The nature of the designs allows for their realization using a variety of materials. The designs were based on a phantom, 14 cm in diameter, composed of 40% fibroglandular and 60% adipose tissue. Bowtie design #1 is based on single material spectral matching and produces nearly uniform spectral shape for radiation incident upon the detector. Bowtie design #2 uses the idea of basis-material decomposition to produce the same spectral shape and intensity at the detector, using two different materials. With bowtie design #3, it is possible to eliminate the beam hardening effect in the reconstructed image by adjusting the bowtie filter thickness so that the effective attenuation coefficient for every ray is the same. Seven different materials were chosen to represent a range of chemical compositions and densities. After calculation of construction parameters for each bowtie filter design, a bowtie filter was created using each of these materials (assuming reasonable construction parameters were obtained), resulting in a total of 26 bowtie filters modeled analytically and in the penelope Monte Carlo simulation environment. Using the analytical model of each bowtie filter, design profiles were obtained and energy fluence as a function of fan-angle was calculated. Projection images with and without each bowtie filter design were also generated using penelope and reconstructed using FBP. Parameters such as dose distribution, noise uniformity, and scatter were investigated. Results: Analytical calculations with and without each bowtie filter show that some materials for a given design produce bowtie filters that are too large for implementation in breast CT scanners or too small to accurately manufacture. Results also demonstrate the ability to manipulate the energy fluence distribution (dynamic range) by using different materials, or different combinations of materials, for a given bowtie filter design. This feature is especially advantageous when using photon counting detector technology. Monte Carlo simulation results from penelope show that all studied material choices for bowtie design #2 achieve nearly uniform dose distribution, noise uniformity index less than 5%, and nearly uniform scatter-to-primary ratio. These same features can also be obtained using certain materials with bowtie designs #1 and #3. Conclusions: With the three bowtie filter designs used in this work, the selection of material is an important design consideration. An appropriate material choice can improve image quality, dose uniformity, and dynamic range.
Use of analytical gel chromatography to analyze tertiary and quaternary structural changes in E. coli aspartate transcarbamylase.

Abstract E. coli aspartate transcarbamylase (ATCase) is large (310 kDa) protein that undergoes major changes in quaternary structure when substrates and regulatory nucleotides bind. We have used analytical gel chromatography to detect quaternary structure changes in both the holoenzyme and its catalytic subunit (c 3 ), to characterize the quaternary structure of single site mutant proteins and to monitor urea-induced dissociation and unfolding of c 3 . Binding of the bisubstrate analog PALA ( N -(phosponacetyl)-L-aspartate) to ATCase and c 3 has been shown to alter s 20,w by −3.3% and + 1.4%, respectively [Howlett, G.J. and Schachman, H.K. (1977), Biochemistry 23, 5077–5083]. The corresponding changes in the chromatographic partition coefficient (σ) are −2.6±0.3% and 5.5±1.9% on Sephacryl S400HR and S200, respectively. Partition coefficients of mutant ATCases with single site mutations in the c chain differ from those of the wild-type protein by ±0.5% in small zone experiments, for example, mutations Arg 269 → Gly and Glu 239 → Gln alter the partition coefficient by 0.4% and −0.5%, respectively. The partition coefficient of mutant Glu 50 → Gln and Arg 269 → Gly, but not Glu 239 → Gln are identical to those of the wild type. Results for Glu 239 → Gln are consistent with measurements of activity, small angle X-ray scattering and sedimentation coefficient that indicate that mutations at this site shift the quaternary structure towards the R state [Ladjimi and Kantrowitz (1988), Biochemistry 27, 276–283; Vachette and Herve, cited by Kantrowitz and Lipscomb (1988), Science 241, 669–674; Newell and Schachman (1988), FASEB J. 2, A551]. Results for Glu 50 → Gln are also consistent with measurements of activity (Ladjimi et al. (1988), Biochemistry 27, 268–276). The changes in tertiary and quaternary structure that result from urea-induced denaturation of c 3 result in larger changes in the partition coefficient. Dissociation into folded monomers in 1–1.75 M urea is accompanied by a 4.6% increase in partition coefficient, while denaturation at > 5 M urea gives rise to a 43% decrease on S-300 Sephacryl. The bisubstrate analog PALA suppresses dissociation and increases the copperativity of the unfolding reaction.
Analyses of the performance of liquid dampers for nutation in spacecraft

This paper deals with the performance of liquid-filled dampers for nutation damping of a spacecraft that uses a momentum wheel for attitude stabilization. The damper coupling factor is analyzed for toroidal and rectangular dampers completely filled with liquid, and for the same dampers containing a void, or bubble. Further analysis is made for a U-tube type of resonantly coupled liquid damper. In each case, the damper performance is evaluated relative to the completely filled toroidal liquid damper, illustrating the design regions wherein the damper effectiveness may be substantially improved by the presence of a void, or bubble, in the fluid path. Analysis of the performance of the U-tube resonant damper shows the potential for large gains in coupling factor, and increasingly better time-constant performance (the time constant being inversely proportional to the coupling factor).
''Shielding'' the Knowledge Transfer Process in Human Service Research

Knowledge utilization studies aim to understand the pathways whereby research moves from a specific set of producers to a specific set of consumers. Broadly speaking, two sets of explanations exist: (1) the engineering model, which focuses on the inevitability of science in advancing knowledge, and (2) the socio-organizational model, which stresses the importance of communication between and among groups as the critical factor in promoting utilization. This study asks both research managers at the Department of Health and Human Services and representatives from a particular set of consumer organizations to elaborate on the qualities of the research process that make knowledge most useful to them. We find that the qualities valued in both communities signal convergence around a novel third approach—the shield model—in which aspects of the original two models reinforce a powerful professional norm of objectivity that shelters the knowledge production and transmission process from external political pressures.
Use of Ketorolac after Lower Abdominal Surgery Effect on Analgesic Requirement and Surgical Outcome

BackgroundKetorolac is a nonsteroidal antiinflammatory agent with opioid-sparing properties. The effect of ketorolac on postoperative opioid analgesic requirement and surgical outcome was evaluated in 198 women after abdominal hysterectomy procedures using a double-blind protocol design.MethodsPatie
MLR-induced inhibition of barosensory cells in the NTS.

A central motor command arising from the mesencephalic locomotor region (MLR) is widely believed to be one of the neural mechanisms that reset the baroreceptor reflex upward during exercise. The nu...
Stability of controllers with on-line computations

The dynamical systems theory developed in [4, 7, 8, 9] is applied to the stability analysis of control systems in which the feedback control law requires in real time the solution of a set of nonlinear algebraic equations. Since small sampling period is assumed, the stability and performance of the controlled process can be studied with a continuous-time formulation. A singularly perturbed system is used to model the combined dynamics of the system being controlled and a numerical iterative algorithm required to compute the control law. An updating control procedure has been proposed based on the iterative nature of the control algorithm. The results obtained in [9] regarding the behavior of a dynamical system that models the numerical algorithms lead to a considerable simplification in the analysis. For the case of control problem involving inverse kinematics, the numerical algorithm which solves for inverse kinematics can be considered as an observer (or an estimator) of the state space variables. The study provides an estimate of the required speed of computations to preserve the stability of the controller.
Effect of castration on plasma luteinizing hormone in postpubertal boars

Abstract Two experiments were conducted to test the working hypothesis that mean plasma concentrations of luteinizing hormone (LH) increase as a result of an increase in the frequency and amplitude of the pulsatile releases of LH in postpubertal boars after removal of gonadal steroid hormones by castration. It was further hypothesized that these changes in secretion of LH would be the result of changes in sensitivity of the pituitary to gonadotropin releasing hormone (GnRH). In Experiment 1, plasma LH was monitored in 10 postpubertal crossbred boars (13 to 14 mo old and weighing 159 ± 6.0 kg) at 12-min intervals for 6 h before and 1 h after GnRH (375 ng/kg of body weight) on Days −1, 7, 14, 21 and 29 relative to castration. In Experiment 2, plasma LH was monitored in four castrated and five intact postpubertal boars (11 to 12 mo old and weighing 150 ± 5.1 kg) after each of three doses of GnRH (94, 188 and 375 ng/kg) were administered to each animal. Sample collection occurred 5 wk after castration. Mean LH and frequency of pulsatile releases of LH increased as a result of castration (P
Magnetic field effects on lagrangians and neutrino self-energies in the Salam-Weinberg theory in arbitrary gauges

Abstract An analytic expression for the W-field propagator of the Salam-Weinberg theory in a constant magnetic field is obtained. To obtain the result in an arbitrary weak (ξ) gauge, gauge-fixing terms (different from those usually chosen) must be introduced which are manifestly invariant under electromagnetic gauge transformations. This W-propagator is then used to calculate an expression for the neutrino self-energy in a magnetic field. The result implies an effective neutrino “mass” analogous to that found in the MSW effect. Such a “mass” may be observable in collapsing supernovae. The effective electromagnetic lagrangian is found in an arbitrary (ξ) gauge and shown to be gauge invariant.
Effects of strophanthidin upon contraction and ionic exchange in rabbit ventricular myocardium: relation to control of active state.

Abstract The mechanical responses (active and resting tension, d P d t , TPT) and ionic exchange characteristics (Ca, K, Na) which follow upon perfusion with cardiac glycoside were studied in the arterially perfused rabbit interventricular septum. The augmentation of tension by glycoside is associated with an increase of maximum d P d t and an unchanged or decreased TPT. This inotropic response is accompanied by a net uptake of cellular Ca, a net loss of K and a net uptake of Na. The appearance of toxicity (ectopic beating and contracture) correlates with further net changes in the same direction. The component of Na and K active transport which is affected by glycoside is coupled at a ratio of approximately 2.5 Na : 1 K. Glycoside results in the retention of a fraction of Na influx in a very slowly exchangeable, kinetically inhomogeneous, cellular “compartment”. No significant inotropic response can be measured without evidence for inhibition of Na transport. The study is consistent with the hypothesis that inhibition of active cellular Na transport results in an increased Ca uptake. The latter is the basis for the augmentation of the rate of development of active state typical of glycosidic action. It is proposed that the ionic mechanisms associated with the inotropic response which follows increased frequency of contraction (Bowditch Staircase) and glycoside administration are essentially the same.
A mutual information based approach for target detection through foliage using UWB radar

In this paper, we propose, one novel information theoretic method for target detection through foliage, using ultra wide-band (UWB) radars. This method is based on mutual information between subsequent radar return that makes use of the fact, that there is more random phenomenon in the targeted region. Mutual information is a robust method to extract dependent information and insensitive to nonlinearities. When echoes are in good quality, the detection of target can be achieved by applying our method. Finally, we propose radar sensor network (RSN) and rake structure for poor signal quality, which will integrate the information in the fusion center. Results show that accurate detection can be achieved by this method. The performance of the algorithm was evaluated, based on real world data.
An assessment of the on-orbit performance of the CALIPSO wide field camera

The Wide Field Camera (WFC) is one of three instruments in the CALIPSO science payload, with the other two being the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and the Infrared Imaging Radiometer (IIR). The WFC is a narrow-band, push-broom imager that provides continuous high-spatial-resolution imagery during the daylight segments of the orbit over a swath centered on the CALIOP footprint. The instantaneous field of view of each WFC pixel is approximately 125 m × 125 m when projected on the Earth's surface from an orbit altitude of 705 km. The spectral band of the WFC, with a center wavelength of 645 nm and a FWHM bandwidth of 50 nm, is designed to match the Aqua MODIS instrument's channel 1. The primary WFC Level 1 products are radiance and reflectance registered to an Earth-based grid centered on the CALIOP ground track. "First light" WFC images were acquired on 18 May 2006 and routine data acquisition began in early June 2006. An initial science assessment of the WFC on-orbit performance was conducted based on analysis of the first twelve months of flight data. Comparisons of the WFC measurements with the well-calibrated Aqua MODIS channel 1 data were performed to evaluate the on-orbit radiometric performance of the WFC. Overall agreement is excellent, especially over bright deep convective clouds where the WFC measurements agree to within a few percent of MODIS. This paper provides a summary of our overall assessment of the on-orbit radiometric performance of the WFC.
Modeling poly(vinyl alcohol)-stabilized vinyl acetate emulsion polymerization. II. Comparison with experiment

The mathematical model presented in Part I, accommodating the emulsion polymerization of vinyl acetate stabilized with poly(vinyl alcohol), predicts experimental conversion and particle size data with reasonable accuracy. Model predictions of measurable variables exhibit sensitivity to variables affecting either primary ungrafted particle nucleation of flocculation kinetics, but are relatively insensitive to variables affecting poly(vinyl alcohol) grafting reactions and the resulting primary grafted particle concentration. Semibatch simulations indicate that independent increases in the vinyl acetate, poly(vinyl alcohol), and initiator levels of all increase the primary grafted particle population. It is unlikely, however, that this population exceeds the ungrafted counterpart under most commercial polymerization conditions. This relative insignificance of grafting during particle nucleation is also noted in literature data simulations where, with appropriate parameter adjustments, the model predictions agree well with the batch, thermal initiation data. © 1993 John Wiley & Sons, Inc.
Spatial Characterization of the Atmospheric-Pressure Moderate-Power He Microwave-Induced Plasma

Three-dimensional emission profiles of several metallic and nonmetallic elements from a moderate-power (450 W) atmospheric-pressure helium microwave-induced plasma (He MIP) are presented. A torch using a tangential flow for plasma centering was developed, but the initial goal of forming a stable annular plasma was not achieved. Helium emission gave a symmetrical distribution with maximum emission in the center of the plasma both radially and longitudinally. Calcium atomic emission reached its longitudinal maximum about 3 mm from the cavity bottom and was radially much broader than most nonmetals. The maximum metal ionic emission occurred about 6 mm above the cavity bottom. Maximum chlorine emission occurred still higher and was not affected by nebulized water in the plasma. Emission distribution and behavior suggests that different excitation mechanisms exist for metals and nonmetals.
Analog field plotter — Description and use

The conductive-sheet analog field plotter is a versatile instrument for the study of various types of 2-dimensional field patterns. By means of a field plotter, one can frequently optimize the design of a device without having to fabricate several experimental models. Thus, a substantial savings in both time and money can be achieved.
Enzymatic degradation of succinyl-coenzyme A by rat liver homogenates

Abstract When a dilute suspension of the mitochondrial fraction of rat liver homogenates was incubated with chemically synthesized succinyl-CoA, a product was rapidly formed which was retained at pH 3.9 on Dowex 50 (H+). Although its acid-base properties were indistinguishable from those of δ-aminolevulinic acid, the product did not form a pyrrole with acetylacetone, nor was its enzymatic formation dependent on added glycine. The enzyme which cleaved succinyl-CoA to the δ-aminolevulinic acid-like product was inhibited by phenylmethyl sulfonylfluoride. The first substance formed by the peptidase was the unstable thioester of succinic acid and cysteamine which underwent rearrangement to the more stable N-succinyl cysteamine above pH 4.0. It is apparent that the assay of δ-aminolevulinic acid synthetase (EC 2.3.1.37) by the ion-exchange method of Ebert et al. (Ebert, P.S., Tschudy, D.P., Choudhry, J.N. and Chirigos, M.A. (1970) Biochim. Biophys. Acta 208, 236–250) can yield erroneous results with succinyl-coenzyme A as substrate, especially when incubations are carried out for less than 25 min.