cssi/SciSciGPT-SciSciNet huggingface dataset:
PREDICTORS OF SELENIUM CONCENTRATION IN HUMAN TOENAILS

To assess the validity of the selenium concentration in human toenails as a measure of selenium intake and to determine other correlates of toenail selenium level, the authors examined the predictors of toenail selenium within two subgroups of a large cohort study of US women. Mean toenail selenium was higher among 38 consumers of selenium supplements (0.904 micrograms/g, standard deviation (SD) 0.217) than among 96 nonusers (0.748 micrograms/g, SD 0.149; p less than 0.001), and a dose-response relation was observed among supplement users (Spearman's r = 0.32; p = 0.05). In a second subgroup of 677 women, selenium supplement use was also associated with higher mean toenail selenium (0.906 micrograms/g, SD 0.214, among 18 users and 0.801 micrograms/g, SD 0.148, among 659 nonusers; p = 0.02), and the dose-response relation was also significant (Spearman's r = 0.50; p = 0.03). The geographic variation in toenail selenium levels was consistent with the geographic distribution of selenium in forage crops. Toenail selenium declined with age and was significantly reduced among cigarette smokers (mean = 0.746, SD 0.124, among 146 current smokers and mean = 0.817, SD 0.159, among 311 never smokers; p less than 0.001) but was not materially affected by alcohol consumption. A dietary selenium score calculated from a food frequency questionnaire failed to predict toenail selenium level, demonstrating the suspected inability of diet questionnaires to measure individual selenium intake because of the highly variable selenium composition of different samples of the same food.(ABSTRACT TRUNCATED AT 250 WORDS)
Verification, validation, and accreditation of simulation models

This chapter discusses the role of verification and validation in determining simulation correctness and establishing the credibility that should be given to simulation results. The primary function of verification and validation is to reduce the risk of inappropriate simulation use. That information is the basis for accreditation decisions about use of the simulation. How verification, validation, and accreditation fit in the simulation life cycle is described. Key verification and validation processes are identified, and their use discussed. References to more detailed information are provided.
Potential influence of climatic change on soil organic matter and tropical agroforestry.

Publisher Summary This chapter introduces a simple model for estimating the temperature sensitivity of soil organic matter (SOM) and calculating the change in global SOM distribution that would be likely to accompany global warming. The implications of the predicted changes are outlined in terms of the global carbon cycle and the management of SOM in tropical agroforestry systems. The total amount of organic matter in the soil depends on the balance of biomass production and decomposition, and on the soils capacity for organic matter storage. It is, therefore, sensitive to temperature and precipitation and is quite variable at local scales. The role of temperature in determining the global pattern of SOM follows directly from its differential effects on production (additions to SOM) and decomposition (losses of SOM). The differential temperature sensitivities of production and decomposition processes, reflected in the SOM model, can apparently actuate decrease in the carbon density of the world's soils as global temperature increase. The rate of decomposition changes more rapidly as a function of temperature than does productivity. Management of SOM for productivity maintenance or enhancement is a unifying feature of tropical agricultural and agroforestry practices.
Spatial analysis of elderly access to primary care services

Admissions for Ambulatory Care Sensitive Conditions (ACSCs) are considered preventable admissions, because they are unlikely to occur when good preventive health care is received. Thus, high rates of admissions for ACSCs among the elderly (persons aged 65 or above who qualify for Medicare health insurance) are signals of poor preventive care utilization. The relevant geographic market to use in studying these admission rates is the primary care physician market. Our conceptual model assumes that local market conditions serving as interventions along the pathways to preventive care services utilization can impact ACSC admission rates. We examine the relationships between market-level supply and demand factors on market-level rates of ACSC admissions among the elderly residing in the U.S. in the late 1990s. Using 6,475 natural markets in the mainland U.S. defined by The Health Resources and Services Administration's Primary Care Service Area Project, spatial regression is used to estimate the model, controlling for disease severity using detailed information from Medicare claims files. Our evidence suggests that elderly living in impoverished rural areas or in sprawling suburban places are about equally more likely to be admitted for ACSCs. Greater availability of physicians does not seem to matter, but greater prevalence of non-physician clinicians and international medical graduates, relative to U.S. medical graduates, does seem to reduce ACSC admissions, especially in poor rural areas. The relative importance of non-physician clinicians and international medical graduates in providing primary care to the elderly in geographic areas of greatest need can inform the ongoing debate regarding whether there is an impending shortage of physicians in the United States. These findings support other authors who claim that the existing supply of physicians is perhaps adequate, however the distribution of them across the landscape may not be optimal. The finding that elderly who reside in sprawling urban areas have access impediments about equal to residents of poor rural communities is new, and demonstrates the value of conceptualizing and modelling impedance based on place and local context.
Effects of Hyperbaric Oxygen on Neurologic Outcome for Cerebral Ischemia in Rats

Objective: To evaluate the effect of hyperbaric oxygen (HBO) therapy on neurologic outcome (assessed by the quantal bioassay approach) following acute focal cerebral ischemia in rats. Methods: Two separate experimental trials were conducted. Trial 1, a nonblinded experiment, used 38 rats. Trial 2, a blinded experiment, used 59 rats. Focal cerebral ischemia was induced with a surgically placed intraluminal occlusion of the left middle cerebral artery; subsequent removal allowed reperfusion. Arterial occlusion times were varied from 5 to 90 minutes in trial 1, and from 3 to 45 minutes in trial 2. The control groups were maintained at ambient pressure for the duration of each trial. The trial 1 treatment group received a single 30-minute HBO treatment at 2.0 atmospheres absolute (ATA) on the initial day of ischemia. The trial 2 treatment group received 30-minute HBO treatments at 2.0 ATA daily for 4 consecutive days. The animals underwent daily 5-point neurologic examinations. A computerized quantal bioassay was used to determine the ET50—the occlusion time required to cause a neurologic abnormality in half of the animals. The control and treatment ET50 values were compared in each trial using a 2-tailed t-test. An increased ET50 for the treatment vs the control group implied a beneficial effect of HBO; a decrease, the opposite. The study had a power of 80% to detect a difference of 11.4 minutes in the ET50 for a 2-sided α= 0.05. Results: For trial 1: the HBO ET50 was 18.1 ± 21.9 minutes and the control ET50 was 22.8 ± 25.0 minutes (p > 0.2). For trial 2: the HBO ET50 was 9.49 ± 17.4 minutes and the control ET50 was 14.9 ± 14.2 minutes (p < 0.2). Conclusion: HBO therapy showed no apparent benefit in a rat model as a treatment modality for acute cerebral ischemia with reperfusion.
Closed laboratories with embedded instructional research design for CS1

Closed laboratories are becoming an increasingly popular approach to teaching introductory computer science courses. However, as observed in [1], "Considering the prevalence of closed labs and the fact that they have been in place in CS curricula for more than a decade, there is little published evidence assessing their effectiveness." In this paper we report on an integrated approach to designing and implementing laboratories with embedded instructional research design. The activities reported here are part of our department-wide effort to not only improve student learning in Computer Science and Computer Engineering, but also to improve the agility of our Computer Science and Engineering Department in adapting our curriculum to changing technologies, incorporate research, and validate the instructional strategies used. This paper presents the design and implementation of the labs and the results and analysis of student performance. Also described in this paper is how we have employed cooperative learning in our labs and how it impacts student learning.
On the origin of ice nuclei

Abstract Aerosol particles from the Earth's surface, man-made aerosols, and particles of extraterrestrial origin are discussed as three independent sources of ice nuclei in the atmosphere. Results of airborne measurements of ice nucleus concentration show extreme variability of the concentration over long distances. On a few occasions the highest concentrations were observed in the vicinity of jet streams. In view of these findings, interest in the Findeisen-Bowen hypothesis is being revived and modifications proposed to account for experimental findings.
476: Steroid-free maintenance immunosuppression with Campath-1H induction in cardiac transplantation

Purpose: Campath-1H (Alemtuzumab) is an anti-CD52 monoclonal antibody that been used extensively in abdominal organ transplantation. Campath produces a sustained lymphopenia and has allowed for steroid-free maintenance immunosuppression in abdominal organ recipients. The use of Campath in cardiac transplantation has not previously been reported. We report our early clinical experience using Campath induction and steroid free maintenance therapy in heart transplant patients. Methods and Materials: Six patients underwent heart transplantation and were placed on a Campath-based immunosuppression protocol at a single institution. All data were collected prospectively. Patients received Campath (30 mg) on the day of surgery and on postoperative day 4 as induction therapy. Steroids were limited to a single intraoperative dose and as pre-medication for Campath. Maintenance immunosuppression was achieved with Tacrolimus and Mycophenolate. Results: The mean age of patients was 52.7 /9.8 years (range 41-66), and 83% were male. There were no perioperative deaths. All myocardial biopsies taken at 1 week, 1 month, and 2 months were ISHLT grade 0. One patient had a biopsy of grade I at 3 months, the others were ISHLT grade 0 (n 3). One patient developed prolonged neutropenia. Maintenance steroid therapy was initiated due to the inability to tolerate Mycophenolate, despite ISHLT grade 0 biopsies. Conclusions: These early results demonstrate that patients receiving induction therapy with Campath had no clinically significant graft rejection despite steroid-free immunotherapy. No adverse effects of Campath treatment were identified. Campath induction and maintenance treatment with Prograf-Mycophenolate may allow for the avoidance of acute and chronic morbidity associated with steroid use in cardiac transplant recipients.
Wave-equation Wavefront Migration

The wave-equation wavefront migration (WWM) is an efficient form of wave equation migration by applying a finite-difference stencil around the leading portion of the wavefront. WWM has the accuracy of wave-equation migration, fewer aliasing and migration artifacts, and can sometimes be faster than the standard reverse-time migration. In this report, we test WWM on the 2-D SEG/EAGE salt model and compare the results with the standard reverse-time migration (RTM). For WWM, we follow the procedure for RTM but apply a finite-difference stencil around an expanding rectanglar area that includes the wavefront (WWM reverse-time migration). Results show that WWM reverse-time migration can be 20% faster than RTM without reducing the image quality. Using the information about the angle of incidence as in wavepath migration, WWM can backproject the reflection energy to the actual reflector. A simple point scatterer model is tested and the result is encouraging.
Enterprise-Wide CR Implementation: The Shands Healthcare System Experience

Major healthcare systems are comprised of hospitals and clinics of different sizes and locations. Many such enterprises are already using picture archiving and communication systems (PACS) and computed radiography (CR) in their main hospitals. The integration of other hospitals and clinics into PACS is a more complex problem. The introduction of CR in remote facilities presents problems, as patient populations, department sizes, and work flow patterns may differ among facilities, and inadequate implementation programs may lead to disruption of patient care services. Although the University of Florida has had an operating PACS for years, facilities affiliated with the Shands Healthcare System (SHS) had not been incorporated into PACS until recently. This article presents the 5-year process to convert all film-screen radiological services to CR in the main hospital, five affiliated community hospitals, and four clinics. The article shows the importance of leadership by the medical physicist from inception of the project through installation and clinical implementation.
Opening, Middlegame, Endgame: Three Metaphors for Pharmaceutical Research

Pharmaceutical research has been likened metaphorically to the game of chess. Comparing these endeavors in moderate detail identifies similarities between them, but also important differences. For example, chess is played by individuals against one another, while pharmaceutical research—at least as usually perceived—is conducted by scientific teams. Drawing a comparison between pharmaceutical research and chess exemplifies the role metaphors can play in stimulating scientific thought and discourse that might otherwise be inaccessible.
Topological-insulator-based non-volatile memory cells: A quantum device simulation

We developed a quantum transport model to simulate the spin-resolved transport properties of a topological insulator (TI) spintronic memory device, which can capture the spin-momentum locking of surface states in TIs and deal with Klein tunneling and coupled spin dynamics. We present a simple design of spin-transfer torque (STT) device which consists of a thin layer TI coupled with a top ferromagnetic film. The device removes the requirement of spin-polarized contacts and magnetic tunnel junctions (MTJs) in conventional STT memory cells by exploiting spin-momentum locking of the TI surface states. The analysis shows that by introducing partial perpendicular magnetic anisotropy (PPMA), both fast switching and low switching current can be achieved.
A Practice Guideline Revisited: Screening for Hypertension

In 1993, the Clinical Efficacy Assessment Subcommittee began evaluation of new topics and reevaluation of previous guidelines on common screening tests, which were published in Annals of Internal M...
High resolution transmission electron microscopy study of defect structures in mixed-phase YBaCuO

Mixed-phase superconducting YBaCuO is characterized by means of high-resolution transmission electron microscopy. This technique reveals that such material contains numerous crystallographic defects of various types. Several of these are described in detail, and their origins discussed.
Meandering of water rivulets

Etude des filets de ruissellement produits sur des plaques inclinees de polyethylene, de Mylar, de Plexiglas et d'acetate. Determination des conditions d'instabilite et de formation de meandres. Correlation avec une theorie unidimensionnelle aux grands nombres de Reynolds dans laquelle il y a equilibre entre les gradients de pression dus a la courbure, a la tension superficielle et a l'hysteresis de l'angle de contact
Stretch-activated force-shedding, force recovery, and cytoskeletal remodeling in contractile fibroblasts

Abstract The stress fiber network within contractile fibroblasts structurally reinforces and provides tension, or “tone”, to tissues such as those found in healing wounds. Stress fibers have previously been observed to polymerize in response to mechanical forces. We observed that, when stretched sufficiently, contractile fibroblasts diminished the mechanical tractions they exert on their environment through depolymerization of actin filaments then restored tissue tension and rebuilt actin stress fibers through staged Ca ++ -dependent processes. These staged Ca ++ -modulated contractions consisted of a rapid phase that ended less than a minute after stretching, a plateau of inactivity, and a final gradual phase that required several minutes to complete. Active contractile forces during recovery scaled with the degree of rebuilding of the actin cytoskeleton. This complementary action demonstrates a programmed regulatory mechanism that protects cells from excessive stretch through choreographed active mechanical and biochemical healing responses.
Making space, making race: reconstituting white privilege in Buckhead, Atlanta

The comfortable relationship between the overwhelmingly white, southern Atlanta neighborhood of Buckhead and a major hub of nightlife in the region unraveled in the early 2000s as the entire nightclub cluster was delegitimized, discursively constructed as dangerous and out of control, and ultimately razed to make space for luxury shopping. This paper sets out to query what social and cultural relations account for this massive and unpredicted reconfiguration of urban space in the epicenter of wealth, whiteness, and power in Atlanta. By mobilizing the concept of the socio-spatial dialectic (Soja 1980, Annals of the Association of American Geographers 70: 207–225), we draw on Pulido's (2000, Annals of the Association of American Geographers 90: 12–40) work on the construction and perpetuation of white privilege to argue that the racialized production of space is a relevant framework for understanding the processes at work in Buckhead. We argue that race was an unstated but deeply important social relation s...
Physicochemical characterization of cyanophage SM-2

Cyanophage SM-2 which infects two unicellular cyanobacteria, Synechococcus elongatus UTEX 563 and Microcystis aeruginosa NRC-1 (Synechococcus sp. NRC-1) UTEX 1937 has a buoyant density of 1.483 g/cm3, a DNA buoyant density of 1.729 g/cm3 and a guanine + cytosine (G+C) content of 69–70%. The protein patterns of cyanophage SM-2 particles showed 11 bands, as determined by polyacrylamide gel electrophoresis, with the bulk of the protein mass concentrated at the 39,000 Mr band. There appear to be no cross-reacting anibodies to whole virus particles of cyanophages SM-1, SM-2 and AS-1. Cyanophage SM-2 requires the presence of cations for viral stability.
Measurement of the Ionospheric Faraday Effect by Radio Waves reflected from the Moon

ROTATION of the plane of polarization (the Faraday effect) of radio echoes from the Moon has been used by Browne, Evans, Hargreaves and Murray1 and by Evans2 to determine the total electron content of the ionosphere. The method is based upon the fact that the plane of polarization of a linearly polarized wave during its double passage through the ionosphere is rotated by an amount: where ƒ is the frequency of the transmitted wave in c./s., B is the Earth's magnetic field in gauss at ionospheric levels, θ is the angle between the direction of propagation and the Earth's field, δ is the zenith angle of the path, N is the electron density per cm.3 and dh is an element of height in cm. The limits of integration correspond to the region in which the ionization is large enough to make an appreciable contribution to the rotation. The assumption is made that B is constant throughout this region and has a value of 0.5 gauss. The value of the constant in the above equation published by Browne, et al. 1 appears to be in error by a factor of two, although the value given at a later date by Evans2 is correct. The reason for the error is that the angular rotation was taken to be equal to the phase difference between the ordinary and extraordinary rays. The parameter of interest, however, is the displacement from its initial position of the resultant of two vectors, one of which has rotated clockwise and one counter-clockwise. This resultant is displaced (ϕ1 − ϕ2)/2 from its initial position, where ϕ1 and ϕ2 are the absolute values of the rotations of the two component vectors.
Device fabrication and integration with photodefinable microvalves for protein separation

Plastic microfluidic devices were fabricated with an array of microvalves for two-dimensional protein separation. The devices were made by compression molding, a technique in which plastic resin is introduced into an open mold and formed under heat and pressure. The mold was created, via electroplating, from a silicon or glass master fabricated by photolithography. The fidelity in the pattern transfer from the master, through the mold, to devices was confirmed by the reproduction of channel depth and nanostructures on channel walls, and was independent of the molding temperature and compression force over the range of conditions investigated. An array of microvalves was created at the intersections of orthogonal channels by photodefinable, in situ gel polymerization; these valves enable the introduction of two types of separation media into orthogonal channels for performing two-dimensional protein separation in a microfluidic device. We demonstrated the utility of the device by separating proteins using the mechanism for the first dimension, isoelectric focusing.
Synthesis, nicotinic acetylcholine receptor binding, antinociceptive and seizure properties of methyllycaconitine analogs.

Abstract A series of methyllycaconitine (1a, MLA) analogs was synthesized where the (S)-2-methylsuccinimidobenzoyl group in MLA was replaced with a (R)-2-methyl, 2,2-dimethyl-, 2,3-dimethyl, 2-phenyl-, and 2-cyclohexylsuccinimidobenzoyl (1b–f) group. The analogs 1b–f were evaluated for their inhibition of [125I]iodo-MLA binding at rat brain α7 nicotinic acetylcholine receptors (nAChR). In order to determine selectivity, MLA and the analogs 1b–f were evaluated for inhibition of binding to rat brain α,β nAChR using [3H]epibatidine. At the α7 nAChR, MLA showed a Ki value of 0.87 nM, analogs 1b–e possessed Ki values of 1.67–2.16 nM, and 1f showed a Ki value of 26.8 nM. Surprisingly, the analog 1e containing the large phenyl substituent (Ki = 1.67 nM) possessed the highest affinity. None of the compounds possessed appreciable affinity for α,β nAChRs. MLA antagonized nicotine-induced seizures with an AD50 = 2 mg/kg. None of the MLA analogs were as potent as MLA in this assay. MLA and all of the MLA analogs, with the exception of 1b, antagonized nicotine’s antinociceptive effects in the tail-flick assay. Compound 1c (Ki = 1.78 nM at α7 nAChR) with an AD50 value of 1.8 mg/kg was 6.7 times more potent than MLA (AD50 = 12 mg/kg) in antagonizing nicotine’s antinociceptive effects but was 5-fold less potent than MLA in blocking nicotine-induced seizures. Since MLA has been reported to show neuroprotection against β-amyloid1–42, these new analogs which have high α7 nAChR affinity and good selectivity relative to α,β nAChRs will be useful biological tools for studying the effects of α7 nAChR antagonist and neuroprotection.
Security in a peer-to-peer data grid storage system

The data grid storage systems enable the sharing and coordinated use of data from various sources to fit the needs of many data-intensive applications. Many data grids are being developed in various application domains, such as bioinformatics, health care, geo-science, military information systems, etc. The storage subsystem in a data grid plays an important role and can have significant impact on data grid security, dependability, and access performance.
M-lattice: from morphogenesis to image processing

The paper is based on reaction-diffusion, a nonlinear mechanism first proposed by Turing in 1952 to account for morphogenesis, the formation of shape and pattern in nature. One of the key limitations of reaction-diffusion systems is that they are generally unbounded, making them awkward for digital image processing. In this paper we introduce the "M-lattice", a system that preserves the pattern-formation properties of reaction-diffusion and is bounded. On the theoretical front, we establish how the M-lattice is closely related to the analog Hopfield network and the cellular neural network, but has more flexibility in how its variables interact. Like many "neurally inspired" systems, the bounded M-lattice also enables computer or analog VLSI implementations to simulate a variety of partial and ordinary differential equations. On the practical front, we demonstrate two novel applications of reaction-diffusion formulated as the new M-lattice. These are adaptive filtering, applied to the restoration and enhancement of fingerprint images, and nonlinear programming, applied to image halftoning in both "faithful" and "special effects" styles.
The Controversy at Rockefeller Center: Phantom Publics, Aesthetic Barbarians

This article investigates the Rivera controversy at Rockefeller Center arguing that the controversy illuminates tensions in democratic culture over the role of the masses and their relation to the “legitimate” public, exhibited in anxieties about phantom publics and barbarian crowds. Beginning with critical discourse surrounding the construction of Rockefeller Center, the mural controversy is resituated within a broader frame in which revanchist anxieties and worry about mass media play a crucial role. Appeals during the construction of the building to the “public” character of the structure took on a life of their own during the apex of the Rivera controversy.
Advanced Materials in Automotive Engines

Titanium, magnesium, rapidly solidified aluminum alloys, ceramics, metal matrix composites, ordered aluminides and plastics are among the materials discussed as being of interest for application in future automotive engines. Metal matrix composites, the subject of four talks and mentioned in several others, receive the most attention. The advantages offered by metal matrix composites compared to the properties of the matrix materials, usually aluminum or magnesium, include increased stiffness and wear resistance, improved strength, particularly at elevated temperatures, and a reduced thermal expansion coefficient. An additional advantage of metal matrix composites is the ability to tailor the composite to suit the needs of a particular application by modifying the type and amount of reinforcement or, in some instances, by selective reinforcement. Interest in these materials has been fueled by the development of fabrication methods, such as squeeze casting and powder metallurgy, which promise to reduce costs to levels affordable for high-volume production automotive parts.
Photodisintegration of the Deuteron

The electric dipole cross section for $\ensuremath{\gamma}(d, p)n$ is examined, assuming no forces in $^{3}P$ states. The nonvanishing $D$-state probability ${P}_{D}$ of deuteron gives rise to the isotropic part ${a}_{e}$ in angular distribution of the photoproton: $\frac{d\ensuremath{\sigma}}{d\ensuremath{\omega}}={a}_{e}+{b}_{e}{sin}^{2}\ensuremath{\theta}$. It turns out, however, that the resulting value for ${a}_{e}$ is still small to explain the experimental cross section, even if ${P}_{D}$ is as large as 8 percent.
Guiding lights for antihypertensive treatment in patients with nondiabetic chronic renal disease: proteinuria and blood pressure levels?

In this issue, Jafar and colleagues address three questions about the management of patients with nondiabetic kidney disease and hypertension: Does the amount of urinary protein affect outcomes? Ar...
Single extrachromosomal ribosomal rna gene copies are synthesized during amplification of the rDNA in tetrahymena

A novel form of extrachromosomal rDNA has been identified in conjugating Tetrahymena cells. This rDNA consists of 11 kb linear double-stranded DNA molecules, each containing a single rRNA gene copy. The DNA sequence, tandemly repeated CCCCAA (Blackburn and Gall, 1978) found at the termini of extrachromosomal palindromic rDNA (the macronuclear form found in vegetatively growing cells), is also present at the corresponding terminus of the 11 kb rDNA. The other end of this molecule has an extra 0.3 kb segment of DNA covalently attached to the DNA region corresponding to the center of the palindromic rDNA. The kinetics of appearance and synthesis of the 11 kb rDNA early in macronuclear development are consistent with its being an intermediate in rDNA amplification.
CHANGES IN ACADEMIC RESEARCH PERFORMANCE OVER TIME: A Study of Institutional Accumulative Advantage

This study examines changes in institutional research performance over time by analyzing data from four national surveys of the American professoriate conducted between 1969 and 1988. To assess whether groups of institutions may be accumulating advantage relative to others, research activities are compared across five Carnegie institution types. Weights are created to adjust for sampling differences and research output measures are standardized to adjust for variation by discipline. Findings show an overall strengthening of research emphasis reflected by a stronger orientation toward research (more faculty holding Ph.D.'s and having a primary interest in research) and higher research output (grant and publication performance). While Research-I universities have retained their initial (1969) advantage, they have not accumulated more. Meanwhile, Doctoral-Granting-I universities have gained strength relative to Research-II institutions. Research at Comprehensive-I was also up, but at a slower rate than the other Carnegie groups.
Results of the Randomized Aldosterone Antagonism in Heart Failure with Preserved Ejection Fraction trial (RAAM-PEF).

Abstract Background Cardiac fibrosis is a major determinant of myocardial stiffness, diastolic dysfunction, and heart failure (HF). By reducing cardiac fibrosis, aldosterone antagonists have the potential to be beneficial in heart failure with preserved ejection fraction (HFpEF). Methods and Results In a randomized, double-blind, placebo-controlled trial of 44 patients with HFpEF, we examined the effects of eplerenone, an aldosterone antagonist, on changes in 6-minute walk distance (primary end point), diastolic function, and biomarkers of collagen turnover (secondary end points). All patients had a history of hypertension, 61% were diabetic, and 52% had prior HF hospitalization. After 6 months of treatment, similar improvements in 6 minute walk distance were noted in the eplerenone and placebo groups ( P = .91). However, compared with placebo, eplerenone was associated with a significant reduction in serum markers of collagen turnover (procollagen type I aminoterminal peptide, P = .009 and carboxy-terminal telopeptide of collagen type I, P = .026) and improvement in echocardiographic measures of diastolic function (E/E’, P = .01). Conclusions Although eplerenone was not associated with an improvement in exercise capacity compared to placebo, it was associated with significant reduction in markers of collagen turnover and improvement in diastolic function. Whether these favorable effects will translate into morbidity and mortality benefit in HFpEF remains to be determined.
A SIMPLIFIED PROCEDURE FOR THE CONCENTRATION AND PURIFICATION OF INFLUENZA VIRUS.

Objectives Accurate measurement of syndesmophyte development and growth in ankylosing spondylitis (AS) is needed for studies of biomarkers and of treatments to slow spinal fusion. We tested the longitudinal validity and sensitivity to change of quantitative measurement of syndesmophytes using CT. Methods We performed lumbar spine CT scans on 33 patients with AS at baseline, 1 year and 2 years. Volumes and heights of syndesmophytes were computed in four intervertebral disk spaces. We compared the computed changes to a physician9s ratings of change based on CT scan inspection. Sensitivity to change of the computed measures was compared with that of the modified Stoke AS Spinal Score (radiography) and a scoring method based on MRI. Results At years 1 and 2, respectively 24 (73%) and 26 (79%) patients had syndesmophyte volume increases by CT. At years 1 and 2, the mean (SD) computed volume increases per patient were, respectively 87 (186) and 201 (366) mm3. Computed volume changes were strongly associated with the physician9s visual ratings of change (p Conclusions CT-based syndesmophytes measurements had very good longitudinal validity and better sensitivity to change than radiography or MRI. This method shows promise for longitudinal clinical studies of syndesmophyte development and growth.
Effects of Tobacco Smoke on Lung Tissue as measured by Electron Spin Resonance

THE presence of free radicals in tobacco smoke has been reported already. During the course of a programme concerned with free radicals and alkylating agents in tobacco smoke it was observed that the concentration of free radicals in tobacco smoke condensate varied considerably as a function of methods used for collecting and subsequent treatment with solvents. To determine the biological effects of free radicals it became apparent that a method was needed whereby smoke could be directly applied to lung tissue without first collecting and processing the condensate. The method reported here enabled lung tissue to be directly exposed to cigarette smoke in a manner similar to normal smoking and resulted in the observation of distinct changes in the lung tissue as measured by electron spin resonance (ESR).
Use of Transcutaneous Oxygen Tension Before, During, and After Arterial Reconstructive Surgery

The diagnostic and predictive value of transcutaneous oxygen tension (tcPO2) measurements in patients undergoing lower extremity arterial recon structive surgery were evaluated. Foot tcPO2 was measured preoperatively in 114 patients, intraoperatively in 59 patients, and again seven days after surgery in 82 patients. Preoperative tcPO 2 values less than 30 mmHg were indicative of severe limb ischemia in 90% of patients with rest pain, impending gangrene, or ischemic ulcer. Fifteen minutes after revascularization, tcPO2 greater than 30 mmHg was predictive of a "good" result (determined clinically at one month) in 94% of patients, whereas values less than 30 mmHg predicted a "poor" result in 70% of patients. Measurements obtained seven days postoperatively exhibited an improved negative predictive tcPO2 value (85%) as compared with those ob tained intraoperatively. TCPO2 changes induced by oxygen inhalation were the most promising predictor of the outcome of surgery. TCPO2 was uniformly more reliable than he...
The Proteomic Constraint and Its Role in Molecular Evolution

Recently, the concept of a "Proteomic Constraint" was introduced to explain the frequency of genetic code deviations in mitochondrial genomes. The Proteomic Constraint was proposed to be proportional to the size of the mitochondrially encoded proteome, hence small proteomes are expected to experience smaller total numbers of errors resulting from genetic code deviations, leading to less likelihood of causing lethality. The concept is now extended to encompass several other aspects of the genetic information system. When the Proteomic Constraint is small, it is proposed that there is little selective pressure to evolve or maintain error correction mechanisms, as a result of the smaller total number of errors that accumulate. Conversely, a large Proteomic Constraint is proposed to result in a correspondingly large selective pressure to evolve or maintain error correction mechanisms. Differences in the size of the Proteomic Constraint can help to explain differences in replicational, transcriptional, and translational fidelities between genomes. A key piece of evidence is the existence of negative power law relationships between proteome size and error rates; these are demonstrated to be diagnostic of the action of the Proteomic Constraint. The Proteomic Constraint is argued to be a major factor determining mutation rates in a diverse range of DNA genomes, implying that mutation rates are clock like. A small Proteomic Constraint partly explains why RNA viruses possess high mutation rates. A reduced Proteomic Constraint in intracellular pathogenic bacteria predicts a drift upwards in mutation rates. Differences in the Proteomic Constraint also appear to be linked to differences in recombination rates between eukaryotes. In addition, a reduced Proteomic Constraint may explain features of resident genomes, such as loss of DNA repair pathways, increased substitution rates, and AT biases, in addition to the occurrence of genetic code deviations. Thus, it is argued that the Proteomic Constraint is a universal factor that influences a wide range of properties of the genetic information system.
SAFETY OF INTRAVASCULAR TOCOPHEROL IN A RANDOMIZED DOUBLE BLIND TRIAL IN PREMATURE INFANTS

We prospectively studied the potential side effects of parenteral vitamin E or tocopherol (T) while testing its effectiveness in preventing Retinopathy of Prematurity (ROP). 287 infants grade I, (28% P vs 30% T); hepatomegaly of >2 cm (11% P vs 15% T); proven sepsis occurring after 48 hrs of age (7% P vs 6% T); and proven NEC (4% P vs 4% T) did not differ between the two groups. This sample size permitted 75-95% confidence for an increased incidence of any one side effect of 10 percentage points, alpha = 0.1. The early intravascular, followed by oral, use of tocopherol appears to be safe as used in this study, providing plasma levels are carefully monitored and kept below 3.5 mg/dl.
Video modeling: Why does it work for children with autism?

Video modeling is a well-validated intervention documented in the behavioral sciences. It has been used to target a variety of behaviors across many areas of functioning including language, social behavior, play, academics and adaptive skills. The methodology appears particularly efficacious for children with autism. In this review of research applications of video modeling, we explore several plausible explanations that contribute to the unique benefits of television/video methodology. We discuss the specific characteristics of autism that may provide a rationale for using visually cued instruction that restricts the field of focus while not imposing too much demand on social attention or interaction. The unique aspects of video presentation are presented within a social learning context (Bandura, 1977, 1986). We also discuss additional explanations pertaining to the features video offers, such a restricted field of focus, repetitive presentation of models and situations, and a context that is typically associated with recreation and is thus viewed with greater receptivity and motivation.
The effect of anesthetic charge on anesthetic-phospholipid interactions

Abstract Cationic and uncharged forms of a tertiary amine local anesthetic are reported to have different properties and potencies as nerve blocking agents. However, the relative capacities of each form of the local anesthetic to perturb the properties of different model membrane systems is unknown. For this reason we have studied the effects of uncharged lidocaine (high pH) and its quaternary amine analogue (W49091) on the phase transition properties of DMPS, DPPE and DPPC liposomes using high-sensitivity differential scanning calorimetry. We report that neutral lidocaine interacts similarly with all three phospholipids. This interaction results in a decrease in the temperature of the gel a liquid crystalline phase transition ( T m ), an increase in the enthalpy of the transition ( ΔH ), and a slight decrease in the cooperativity of melting. Quaternary lidocaine (W49091), on the other hand, interacts significantly with only DMPS; the result being again a decrease in the temperature of DMPS melting, an increase in ΔH , and a slight decrease in the cooperativity of the phase transition. These results are interpreted to indicate that uncharged lidocaine enters the membrane during the DPPE and DPPC phase transitions. In the case of DMPS, an influx of both charged forms of lidocaine must occur at T m . These anesthetic fluxes at the lipid's phase transition are suggested to be responsible for the observed elevated enthalpies of the respective transitions. The observation that the cationic form of lidocaine does not significantly modify the behavior of DPPC and DPPE liposomes suggests that these lipids are not important components of the anesthetic's site in nerve membranes. However, the dramatic perturbation of the properties of DMPS by W49091 suggests that phosphatidylserine may comprise part of this inhibitory site.
The bernard-soulier syndrome.

Abstract The Bernard-Soulier syndrome (BSS) is a rare inherited disorder of platelet function due to absence or markedly decreased expression of the platelet GpIb-V-IX receptor. This receptor plays a critical role in hemostasis by initiating platelet adhesion and subsequent activation at the site of vessel injury. Through its link to the platelet cytoskeleton, the GpIb-V-IX complex appears to be required to maintain normal platelet size and structure. Elucidation of the cDNA and genomic structures of the members of this complex, as well as the mutations responsible for BSS, has greatly advanced our knowledge of the structure and function of the GpIb-V-IX complex in hemostasis . (Trends Cardiovasc Med 1997;7:239–244). © 1997, Elsevier Science Inc .
Numerical Simulation of Convection in Triangular Cavities to Predict Solar Still Performance

To improve modeling of solar still behavior, the convection correlations currently used need to be improved upon. Variations in operating parameters and cover geometries make it difficult to use a single correlation to describe the operation of all solar stills. In this work, three right triangles (representing covers at 15, 30, and 45 deg) were modeled, meshed, and solved to predict the convection heat transfer inside for a variety of operating conditions. For a correlation of the form Nu=C·Ran, it was found that C=1.1, 0.60, and 0.71, and n=0.19, 0.24, and 0.24 for 15, 30, and 45 deg, respectively. A grid dependency study implied error of up to 37% for the computational fluid dynamics data (and therefore the correlation). The correlation is useful for Rayleigh numbers ranging from 2.9×103 to 7.1×108, with error up to 37%. The correlation showed some reasonable agreement with Shruti’s correlation, and extends the range of Rayleigh numbers over which an estimate for the Nusselt number can be made. The res...
How good is good enough? Metrics for worm/anti-worm evaluation

Self-replicating code is a huge problem worldwide, with worms like SQL/Slammer becoming pandemic within minutes of their initial release. Because of this, there has been significant interest in worm spread and how this spread is affected by various countermeasures. However, to date, comparative analysis of spread has been carried out “by eye”—there exist no meaningful metrics by which one can quantitatively compare the effectiveness of different protection paradigms. In this paper, we discuss several possible metrics for measuring worm spread and countermeasure effectiveness. We note that the “correct” metric for comparative purposes will vary depending on the goal of the defender, and provide several different measures which can be used to compare countermeasures. Finally, we discuss the idea of significance—that is, what changes induced by worm design or countermeasures are actually meaningful in the real world?
Induction of endothelialization of tissue-engineered cardiovascular constructs via in vivo angiogenesis during post-implant remodeling

Abstract In vivo remodeling of implants is absolutely unavoidable. A major focus of tissue engineering should be the utilization of these remodeling processes to (1) induce capillarization to nourish three-dimensional tissue constructs, (2) recruit desired functional cells, (3) recruit supporting matrix components, (4) minimize fibrosis and apoptosis, (5) control cellular phenotype, (6) minimize immunologic reactions to allogeneic or xenogeneic cells, and (7) circumvent practical limitations and time requirements of in vitro utilization of autologous cells. Selected biomolecules can either be induced endogenously by biomaterial characteristics or can be added exogenously as either proteins or as genes. Induction of capillarization of implanted cardiovascular implants may be promoted using novel polymer chemistry, architecture or mechanics, or by application of either naturally occurring or engineered mutations of naturally occurring biologic agents. As an example of the first approach, lactide/glycolide copolymeric vascular grafts induce an angiogenic network, which provides endothelium to the implant surface, phenomena not occurring in clinically used graft materials. This difference is mediated largely by generation of FGF-2 production and angiogenesis.
Steroid regulation of the synthesis and secretion of retinol-binding protein by the uterus of the pig.

The endometrium of the pig secretes retinol-binding protein (RBP) under the influence of progesterone (P4). The objective of this study was to determine how conceptus-derived estrogen might modulate this production of RBP around days 11-13 of pregnancy when conceptuses elongate from spheres to long thread-like forms. Concentrations of retinol and RBP were low (35 +/- 7 ng/ml) in uterine flushings obtained on days 10-12 of the estrous cycle or from pregnant gilts in which conceptuses had not elongated. Concentrations of retinol and RBP increased 7- to 8-fold (P less than 0.01) in flushings where filamentous conceptuses were present. Size exclusion and ion exchange chromatography demonstrated that virtually all retinol assayed in uterine flushings was associated with RBP. Northern blot analysis with a cDNA representing uterine RBP revealed a single endometrial mRNA 1.1 kilobases in length. Expression of RBP mRNA in uterine endometrium was measured in ovariectomized prepubertal gilts after the administration...
Quantification of mitral regurgitation in the cardiac catheterization laboratory with contrast echocardiography.

Abstract Background There is no method of quantifying the severity of mitral regurgitation (MR) from injection of tracer directly into the left ventricular (LV) cavity, a method commonly used in the cardiac catheterization laboratory. Methods and Results We used a previously validated mathematical model that derives regurgitant fraction (RF) from the relative tracer washout from the left atrial (LA) and LV cavities. Thirty-nine patients referred for diagnostic cardiac catheterization with clinical evidence of possible MR were included in the study. Five milliliters of a microbubble mixture was power-injected into the LV during simultaneously performed contrast echocardiography. Relative changes in background-subtracted video intensity were measured from the LV and LA, and the resultant model-derived RF was correlated with the severity of MR on cineangiography. The severity of MR ranged from 0 to 4+ on cineangiography with corresponding model-derived RF of 0 to 0.69 on contrast echocardiography. A close linear relation was noted between angiographic severity of MR and model-derived RF on contrast echocardiography ( y = 0.1 x + 0.03, r = 0.89, P Conclusions We describe a new method of measuring the severity of MR in the cardiac catheterization laboratory. Apart from being quantitative, this method can be safely used during cardiac catheterization in patients in whom iodinated contrast agents may be potentially harmful. (Am Heart J 2000;139:1109-13.)