cssi/SciSciGPT-SciSciNet huggingface dataset:
Study of the growth and stability of ultra-thin films of Au deposited on Si(100) and Si(111)

Abstract The growth and stability of ultra-thin films of Au deposited on Si(1 0 0)-2×1 and Si(1 1 1)-7×7 surfaces have been examined as a function of the quantity of Au deposited and substrate temperature using positron-annihilation-induced auger electron spectroscopy (PAES) in combination with electron-induced auger electron spectroscopy (EAES) and low energy electron diffraction. Previous studies have indicated that the PAES signal originates almost exclusively from the top-most atomic layer due to the trapping of the positron in an “image-correlation-well” at the surface before it annihilates. By making use of the selectivity of PAES for the top layer, it was possible to directly monitor the compositional changes in the topmost atomic layer for monolayer and submonolayer depositions of Au on Si(1 0 0) and Si(1 1 1). The PAES intensity was found to increase with increasing Au deposition and then saturate above ∼1 ML for depositions made at 173 K. In contrast, saturation did not occur until ∼2.5 ML when the deposition was performed at 303 K. Plots of the PAES intensity versus Au thickness show a “plateau” at ∼0.5 ML deposition. We interpret the saturation of the PAES signal from Au as an indication that the surface is completely covered by Au atoms after deposition of 1 ML at 173 K. The larger Au thickness required to achieve saturation and the plateau from ∼0.5 ML to ∼1 ML deposition are taken as an indication that, for 303 K deposition, a mixed alloy layer is formed first followed by the growth of a complete Au layer. A model for Au/Si interface formation in terms of Au and Si concentrations measured by PAES and EAES is presented.
PT symmetry and necessary and sufficient conditions for the reality of energy eigenvalues

Abstract The mathematical requirement that a Hamiltonian H be Hermitian is sufficient to guarantee the reality of its eigenvalues, but it is not necessary. By establishing three theorems, this Letter gives conditions that are both necessary and sufficient. First, it is shown that if the secular equation is real, the Hamiltonian is necessarily PT symmetric. Second, the set of all operators C that nontrivially obey the two equations [ C , H ] = 0 and C 2 = 1 is introduced. For a diagonalizable PT -symmetric Hamiltonian it is shown that the set is nonempty and that the energy eigenvalues of H are all real only if every such C commutes with PT . There is at least one complex-conjugate pair of eigenvalues whenever at least one such C does not commute with PT . Third, the eigenvalues of any nondiagonalizable Jordan-block matrix that possesses just one eigenvector are all real if the block is PT symmetric, and are all complex if it is not. These theorems hold for matrix Hamiltonians of any finite dimensionality.
Nature of the effect of caffeine on the drug-metabolizing enzymes.

Abstract Pretreatment of the rat for 3 days with caffeine resulted in an elevation in the drugmetabolizing activity by the hepatic microsomal system. This effect is counteracted by the simultaneous administration of actinomycin D. Caffeine also shortened the duration of action of zoxazolamine and methyprylon in the rat. The stimulatory effect of caffeine on drug metabolism was additive to that of phenobarbital when acetanilide was the substrate but not when o -nitroanisole or aminopyrine was used. Attempts to show increased amino acid incorporation or an increase in cytochrome P-450 in the microsome were not successful. An interesting feature of the stimulatory effect of caffeine on drug metabolism is its short duration after the termination of treatment. Phenobarbital was used throughout this study as a reference compound.
Design of a 12Gb/s transceiver for high-density links with discontinuities using modal signaling

In high-speed chip-to-chip single-ended signaling links, far-end crosstalk presents one of the dominant noise sources, limiting the link performance. Diagonalizing the channel using modal decomposition has been proposed to mitigate the crosstalk, but so far only the transceiver designed for uniform low-loss homogenous media channels has been investigated. In this paper, the design of a transceiver system which takes advantage of modal decomposition over a typical memory bus with discontinuities is presented. The proposed approach is verified using circuit-based link simulation.
Enhancing adoption of an alcohol abuse prevention program: An application of diffusion theory

The purpose of this study was to apply diffusion theory (Rogers, 1983) to an alcohol abuse prevention program in order to enhance program adoption. Three of the four stages of diffusion theory (dissemination, adoption, and implementation) are discussed relative to the development and implementation of a program designed to increase awareness of the destructive effects upon children who live with an addicted parent of living with that parent. The program also focused upon resiliency building strategies to use with children in order to mitigate the harmful effects of addiction in the home. Empirical data are presented concerning the dissemination, adoption and implementation phases of the program.
Structure of the dihydrofolate reductase gene in Chinese hamster ovary cells

Abstract Overlapping recombinant lambda 1059 phages carrying regions of the dhfr locus from the amplified Chinese hamster ovary (CHO) cell clone MK42 have been isolated. In addition, dhfr cDNAs from this cell line have been cloned into plasmid pBR322. Restriction analysis of these recombinant molecules has led to a map of the Chinese hamster dhfr gene. This gene has a minimum size of 26 kb and contains six exons as defined by hybridization to a combination of mouse and CHO cDNA probes. The latter probes reveal 3' exonic sequences that are not present in mouse cDNA. The CHO dhfr gene thus extends about 700 bp further 3' than in the mouse, consistent with the larger size of the hamster mRNA. At least five intervening sequences are present, of approximate sizes: 0.3, 2.5, 8.6, 2.6 and 9.4 kb. Four sequences from highly repeated families are situated in introns within the dhfr gene. The overall structure of this gene is strikingly similar to that of the mouse. Evolutionary conservation of interrupted gene structure among mammals thus extends to genes that code for household enzymes as well as specialized or structural proteins.
Modeling vulnerability of groundwater to pollution under future scenarios of climate change and biofuels-related land use change: A case study in North Dakota, USA

Modeling groundwater vulnerability to pollution is critical for implementing programs to protect groundwater quality. Most groundwater vulnerability modeling has been based on current hydrogeology and land use conditions. However, groundwater vulnerability is strongly dependent on factors such as depth-to-water, recharge and land use conditions that may change in response to future changes in climate and/or socio-economic conditions. In this research, a modeling framework, which employs three sets of models linked within a geographic information system (GIS) environment, was used to evaluate groundwater pollution risks under future climate and land use changes in North Dakota. The results showed that areas with high vulnerability will expand northward and/or northwestward in Eastern North Dakota under different scenarios. GIS-based models that account for future changes in climate and land use can help decision-makers identify potential future threats to groundwater quality and take early steps to protect this critical resource.
Cardiac hypertrophy cannot proceed without initial suppression of protein synthesis

Stress was induced in rat hearts by heat shock and aortic banding and in cardiac cell cultures by heat shock. Proteins were labeled with [35S]-methionine, resolved by electrophoresis, and isotope incorporation measured. Determinations were made during and following stress. The immediate response was stress protein (SP) synthesis, cessation of normally occurring protein synthesis and reduced isotope incorporation. Following recovery, the prestress protein pattern returned, SP synthesis remained high and label incorporation doubled. Response of hearts to the two stresses were similar. Initial suppression may be an important precursor to accelerated protein synthesis seen in hypertrophy.
Immunomodulating functions of recombinant ovine interferon tau: potential for therapy in mulitple sclerosis and autoimmune disorders:

The interferons (IFN) are a family of complex proteins possessing antiviral, antiproliferative, and immunomodulatory activities. Two type 1 recombinant human IFN have been recently approved for the treatment of multiple sclerosis (MS). However, use of high dose type 1 IFN treatment in MS patients has been limited by dose-related toxicity. Ovine IFNt is a unique type 1 interferon discovered for its role in the animal reproductive cycle. It differs from other type 1 IFNs in that it is remarkably less toxic even at high concentrations, is able to cross species barriers, and is not inducible by viral infection. Ovine IFNt has been shown to be very effective in the treatment of animal models of MS. In this study, we examined the toxicity of OvIFNt on human T-cells at high doses and its immunregulatory properties at equivalent doses. Our experiments confirmed the remarkably non-toxic nature of OvIFNt on human cells at high concentrations as well as immunomodulating properties consistent with other type 1 IFNs i...
Ergot alkaloid concentrations in tall fescue hay during production and storage.

Common tall fescue [Lolium arundinaceum (Schreb.) Darbysh. = Schedonorus arundinaceus (Schreb.) Dumort.] is infected with a fungus that produces ergot alkaloids, a class of compounds associated with fescue toxicosis. The objective of this research was to monitor the change in concentrations of ergot alkaloids from time of clipping through storage of tall fescue hay. A 2-yr field study was conducted in Mt. Vernon, MO, in which tall fescue was baled at high moisture (204-219 g H 2 O kg ―1 dry matter [DM]) and low moisture (102-112 g H 2 O kg ―1 DM) then stored for 18 mo. Hay samples were collected over the 540-d period from clipping through storage and analyzed for ergovaline and total ergot alkaloid concentration. Data were analyzed using standard ANOVA procedures and break-point regression. In both years, ergovaline concentrations decreased sharply within the first month after harvest and gradually over the remaining 17 mo. In three of the four cases, most of the ergovaline disappearance occurred within 3 d after clipping. The final ergovaline concentration remained above 250 μg kg ―1 DM, which is still considered toxic to livestock. In the first year, ergot alkaloid concentration followed a pattern similar to ergovaline concentration. In the second year, however, the decrease in total ergot alkaloid was gradual throughout the entire 18 mo. A general recommendation to producers would be to delay feeding toxic tall fescue hay until at least 1 mo after clipping.
Intracellular kinetics of non-viral gene delivery using polyethylenimine carriers.

Polymeric nucleic acid carriers are designed to overcome one or more barriers to delivery. High molecular weight polyethylenimine (PEI) shows high transfection efficiency but exhibits high cytotoxicity (Fischer et al. Biomaterials, 24:1121–1131 (2003); Peterson et al. Bioconjug. Chem., 13:845–854 (2002)). Nontoxic water-soluble lipopolymer (WSLP) was previously developed using branched poly(ethylenimine) (PEI, mw 1,800) and cholesteryl chloroformate (Han, Mahato, and Kim. Bioconjug. Chem., 12:337–345 (2001)) and is an effective non-viral gene carrier with transfection levels equal or above high molecular weight PEI with a lower cytotoxicity profile. To understand how differences in these polymeric carriers influence transfection, we studied the pharmacokinetics of polymer gene carriers at the cellular level. Cells were exposed in vitro to different polymeric carriers and the transport of the carriers into different cellular compartments was determined using cellular fractionation and real-time quantitative PCR. A multi-compartment mathematical model was applied to time series measurements of the trafficking of plasmids across each cellular barrier. Our result indicates that the chemical modification of WSLP increased the rate parameter for endosomal escape significantly compared to conventional PEI carriers thereby increasing the overall transfection efficiency. These results are consistent with the goal of endosomal destabilization of the carrier design. This method provides a quantitative means for assessing different polymer construct designs for gene delivery.
Options-based structural model estimation of bond recovery rates

Abstract The paper demonstrates that a real options structural model of borrower-creditor debt re-negotiations can help explain the cross-sectional variability of losses on defaulted debt securities. The explanatory power of this approach can be improved even further via a system of equations that incorporates additional information by jointly estimating the market values of debt and equity. Empirical tests with a large number of corporate defaults confirm the usefulness of this method. Moreover, higher volatility and lower discount rates around business cycle turning points can result in stakeholders waiting relatively longer for additional returns from defaulted debt. Such optimal stopping behavior based on a real options model mitigates the reduction in face value of debt but can prolong the duration of financial distress.
A simple method for the solution of mathematical models of annular reactors

Abstract In previous work on the modelling of annular reactors, the mass transfer resistance in the central lumen of the reactor has generally either been ignor
State university boards of trustees: A principal-agent perspective

This paper extends the economic theory of organizations by examining the structure of boards of trustees in public university settings. A major implication of the analysis is that the structure of the board of trustees reflects the costs to politicians of allowing internal agent shirking. Empirical evidence supports this hypothesis and indicates that a system method of governing versus individual board governance of universities is linked to the influence of educators in the political process.
An anatomy of Bullish Underlying Linked Securities

Abstract Bullish Underlying Linked Securities (BULS) represent another type of equity-linked structured notes. BULS are designed to meet the needs of retail investors, who give up certain upside capital appreciation potential over a period of time in exchange for enhanced principal protection. A BULS valuation model is derived through a replication strategy. The application of the valuation model to a particular BULS issue shows that these BULS were overpriced by the market during the seasoning period, but were fairly priced during the rest of the sample period.
Physiological energetics of the ribbed mussel Geukensia demissa (Dillwyn) in response to increased temperature

Abstract The effects of acute and prolonged increase in temperature on the components of the energy budget were determined for the ribbed mussel Geukensia demissa (Dillwyn). With the exception of absorption efficiency, all of the measured physiological parameters exhibited significant change in response to elevated temperature. Aerial respiration increased when temperature was increased from 15 to 25 ° C and then exhibited partial acclimation. Aquatic respiration increased similarly but did not exhibit significant acclimation during the 21 days of the experiment. Clearance rates increased with elevated temperature but then continued to increase over the course of the experiment. Ammonia excretion rate exhibited a minor increase upon acute exposure to 25 ° C, increased greatly during the 1st wk and returned to control values by the end of the experiment. The complex pattern of physiological response resulted in an improvement of energy balance upon exposure to elevated temperature and acclimation processes resulted in a further improvement of energy balance for the group maintained at 25 ° C relative to those maintained at 15 ° C.
Theoretical analysis of a transdermal ferromagnetic implant for retention of magnetic drug carrier particles

The use of a ferromagnetic wire implant placed near an artery to assist the collection of magnetic drug carrier particles (MDCPs) using an external magnet is theoretically studied. Three magnetic drug targeting (MDT) systems are evaluated in terms of their MDCP collection efficiency (CE): a permanent magnet and wire is better than a permanent magnet alone, which is better than a homogeneous magnetic field and wire.
Computerized adaptive testing, anxiety levels, and gender differences

This study compares the amount of test anxiety experienced on a computerized adaptive test (CAT) to a paper-and-pencil test (P&P), as well as the state test anxiety experienced between males and females. Ninety-four middle school CAT examinees were compared to 65 middle school P&P examinees on their responses to the State-Trait Anxiety Inventory for Children (STAIC) after taking a standardized achievement test. Results of a multiple regression showed that P&P examinees had a higher mean STAIC score than CAT examinees after controlling for trait test anxiety and computer anxiety. Evidence of neither a main nor a moderator effect of gender was found. However, a subsequent path analysis gave evidence of an indirect effect of gender on STAIC score mediated by trait test anxiety. Results are discussed in the context of stereotype threat and the implications for the use of CAT in schools, given the digital divide between race and socioeconomic status. Recommendations for future research and practice are offered.
DYNAMIC ICE SURFACE IN THE POLAR STRATOSPHERE

Heterogeneous reactions on polar stratospheric clouds (PSCs), such as ClONO2+HCl — Cl2+HNO3, are important for an understanding of the production of active chlorine species (HOCl, Cl2) and Antarctic ozone depletion. H2O-ice forms the Type II PSCs and the nature of H2O-ice surfaces under stratospheric conditions may affect the heterogeneous chemistry. This review focuses on recent measurements of H2O adsorption kinetics on ice, H2O desorption kinetics from ice, H2O surface diffusion on ice and H2O diffusion into ice. These measurements reveal that the ice surface is extremely dynamic under polar stratospheric conditions. For example, the residence time for an H2O molecule on an ice surface at 188 K is only ~20 milliseconds before desorption and only ~0.4 milliseconds before diffusion into the ice bulk. The dynamic nature of the ice surface may significantly affect the adsorption, solvation, diffusion and reaction of the chlorine reservoir molecules (ClONO2, HCl). The dynamic ice surface may also serve as a model for the surfaces of other molecular solids.
CFD modeling of the effect of polymer elasticity on residual oil saturation at the pore-scale

Abstract Polymers are used in enhanced oil recovery (EOR) to increase sweep efficiency, but recent experimental and field data suggest that viscoelastic polymers such as hydrolyzed polyacrylamide (HPAM) reduce residual oil saturation as well. The observed reduction contradicts decades of belief that polymers could not be used to reduce residual oil because the additional pressure required to overcome capillary pressure is orders of magnitude greater than provided by the more viscous polymer. However, additional forces (such as normal stress forces) may be significant for viscoelastic fluids that are ignored in analysis of purely viscous fluids. We perform computational fluid dynamics (CFDs) simulations of viscoelastic flow around static oil droplets in geometries representative of pore throats. We show that normal forces are significant for viscoelastic fluids and increase with De and the total force imposed on the droplet may be larger than an equivalent Newtonian fluid with the same viscosity. Results indicate that normal forces could dominate and the total, effective force would be enough to mobilize trapped oil.
The geochemistry of strontium

Abstract The geochemistry of strontium has been investigated, using an emission spectrographic technique checked by isotope dilution analyses described elsewhere ( Turekian et al., in press). Hence the determinations are claimed to have good accuracy as well as precision. Approximately 700 analyses have been made on silicate rocks and over 300 on carbonate materials (a detailed analysis of the latter appearing in other papers). An attempt was made at a representative sampling of the crust of the earth. The difference in behaviour of strontium relative to calcium in granitic rocks as compared to basaltic rocks is striking. For granitic rocks there is an increase of strontium content with an increase in calcium not only for samples from a single batholith but also when extended to a universal sampling. On the other hand, though some differentiated basaltic bodies show a covariance of strontium and calcium, it is always with the strontium content increasing as the calcium content decreases. On a worldwide basis, however, this relationship is destroyed because marked regional variations subdue any differentiation effects that might be present locally. The crustal abundance of strontium in basaltic rocks may be estimated without difficulty by taking a simple average, but a similar procedure for granitic rocks is ruled out because of the dependence of strontium content on rock-type. The table below summarizes the abundances of strontium in the various phases of the earth's crust.
Relational priming plays a supporting but not leading role in adult analogy-making.

Leech et al.'s analysis adds to an emerging consensus of the role of priming in analogy-making. However, their model cannot scale up to adult-level performance because not all relations can be cast as functions. One-size-fits-all accounts cannot capture the richness of analogy. Proportional analogies and transitive inferences can be made by nonstructural mechanisms. Therefore, these tasks do not generalize to tasks that require structure mapping.
United States Emergency Department Visits for Acute Decompensated Heart Failure, 1992 to 2001

Heart failure is a significant public health problem. The epidemiology and practice pattern of emergency department (ED) visits for acute decompensated heart failure (ADHF) have not been well characterized. A better description is essential to highlight areas in which improvements or additional research are needed. We analyzed all ED visits for ADHF of patients ≥40 years old using the data of the National Hospital Ambulatory Medical Care Survey from 1992 to 2001. During this 10-year period, an estimated 10.5 million ED visits occurred for ADHF, representing 2.9% of all ED visits. The number of ADHF visits increased on average by 18,500 per year, for a 19.4% absolute increase during the decade. The rate per 1,000 United States population was unchanged. The average patient was 74 years old, and patients ≥65 years accounted for 79% of visits. Loop diuretics were administered in 63% and vasodilators in 29% of visits. The ED visit rate per 1,000 United States population was 53% higher in blacks than in whites (14.2 vs 9.3). In a multivariate model, white race was a significant predictor of hospitalization. In conclusion, during the past decade, the absolute number of ED visits for ADHF has increased owing to the aging population. Diuretics remain the most common treatment. Race-related differences in hospitalization merit additional study.
Clinical Depression and Condom Use Attitudes and Beliefs Among African American Adolescent Females

Depression, HIV, and other sexually transmitted diseases (STDs) are growing concerns among African American adolescent females. Theoretical models contribute to identification of mediators of condom use; however, minimal research has addressed the explicit relationship between clinical depression and condom use in African American adolescent females. The authors report results from quantitative surveys with clinically depressed ( n = 64) and nondepressed ( n = 64) African American adolescent females in two large metropolitan cities in the eastern United States. Theoretical mediators of condom use in the study sample—attitudes, subjective norms, perceived behavioral control, and intentions—were investigated. Significant differences existed between the groups in condom use frequency (U = 356.5, p = .037); however, there were no statistically significant differences in condom use attitudes and beliefs. Although clinically depressed and nondepressed African American adolescent females may hold similar attitudes and beliefs about condom use, differences in condom use frequency may be a psychopathologic occurrence.
A Monte Carlo Method of Solving Heat Conduction Problems

A new approach in the use of Monte Carlo to solve heat conduction problems is developed using a transport equation approximation to the heat conduction equation. A variety of problems is analyzed with this method and their solutions are compared to those obtained with analytical technique. This Monte Carlo approach appears to be limited to the calculation of temperatures at specific points rather than temperature distributions. The method is applicable to the solution of multimedia problems with no inherent limitations as to the goemetric complexity of the problem.
Numerical Simulation of an Innovative PEM Fuel Cell Stack

This paper describes a novel design approach for a fuel cell stack to address the uniformity of reactant streams and eliminate the bipolar plate to reduce cost, size, volume, and weight. Computational analysis for a novel PEM fuel cell stack and two conventional stacks is conducted. Preliminary results based on a comparison study have shown that eliminating bipolar plates from the fuel cell drastically increases power density, while maintaining uniformity in reactant distribution. Specifically, preliminary case studies suggest that the power density using the novel design is four times that of conventional approaches.Copyright © 2008 by ASME
Effect of chronic ibuprofen therapy on early healing of experimentally induced acute myocardial infarction in dogs.

Abstract Anecdotal evidence has suggested that ibuprofen therapy for concomitant pericarditis may be associated with an increased clinical incidence of ventricular septal rupture after acute myocardial infarction. 1 Decreased tensile strength and increased wall tension in the necrotic region have both been proposed as possible pathogenic factors in cardiac rupture. 2,3 Thus, ibuprofen may "weaken" the myocardium—perhaps by altering the integrity of the native collagen fibroskeleton—and thereby predispose the heart to early postinfarction rupture. This study assesses the effect of chronic pretreatment with high-dose ibuprofen on tensile strength of isolated myocardial samples, left ventricular wall thickness and myocardial collagen content during the initial hours after coronary artery occlusion in an anesthetized dog model of acute myocardial infarction.
Electron microscopic study of the development of herpesvirus saimiri.

Abstract Electron microscopic study of herpesvirus saimiri in thin sections of infected OMK and Vero cells showed the apparent intranuclear envelopment of capsids by membranes of vesicles. Clusters of filaments were also encountered. Numerous unenveloped intracytoplasmic capsids were observed in cells devoid of nuclear changes, raising the possibility that differentiation can occur within the cytoplasm.
Testosterone and Immune Function in Primates: A Brief Summary with Methodological Considerations

The endocrine system serves as a mediator by which the body integrates environmental cues to organize physiological alterations, including changes in immunocompetence. Hormones are central mechanisms that contribute to the onset and timing of key life history events, the allocation of time and energy between competing functions, and in general modulate phenotypic development and variation. Here we provide a very brief review of testosterone and immunity, which highlights the physiological costs that elevated testosterone levels can incur as a result of reproductive investments. We focus primarily on nonhuman primates where possible. Although there is substantial evidence that testosterone exerts some influences on immune responses, results from in vivo studies involving human and nonhuman primates have yielded equivocal results regarding such immunomodulatory actions. There may be several reasons for this, including variation in study design, immunological measures used, levels of other hormones present, host energy status, and even social conditions. We therefore review some of these potential methodological issues, concluding that increased care must be taken to analyze seasonal variability in energy budgets, to collect an adequate number of samples from known individuals, to account for status in the dominance hierarchy when applicable, and to use multiple measures of immunity. We must also seek to understand the collaborative effects of multiple hormones (particularly dehydroepiandrosterone and estradiol) with relation to their downstream immunological effects, assessing both individual and multiplicative actions in both males and females. Such efforts would benefit from the development of additional noninvasive immune measures for primates.
Notes: Natural Hybridization of White Bass with Yellow Bass in Texas

Abstract Isoelectric focusing of diagnostic proteins documented natural hybridization of white bass Morone chrysops with striped bass M. saxatilis in four Texas reservoirs. The occurrence of these hybrids suggests that the threat of introgression within the genus Morone may be greater than previously thought.
Kinetics of the photoreduction of cytochrome b-559 by Photosystem II in chloroplasts

Abstract The kinetics of the photoreduction of cytochrome b-559 and plastoquinone were measured using well-coupled spinach chloroplasts. High potential (i.e. hydroquinone reducible) cytochrome b-559 was oxidized with low intensity far-red light in the presence of N-methyl phenazonium methosulfate or after preillumination with high intensity light. Using long flashes of red light, the half-reduction time of cytochrome b-559 was found to be 100±10 ms, compared to 6–10 ms for the photoreduction of the plastoquinone pool. Light saturation of the photoreduction of cytochrome b-559 occurred at a light intensity less than one-third of the intensity necessary for the saturation of ferricyanide reduction under identical illumination conditions. The photoreduction of cytochrome b-559 was accelerated in the presence of dibromothymoquinone with a t 1 2 = 25–35 ms . The addition of uncouplers, which caused a stimulatory effect on ferricyanide reduction under the same experimental conditions, resulted in a decrease in the rate of cytochrome b-559 reduction. The relatively slow photoreduction rate of cytochrome b-559 compared to the plastoquinone pool implies that electrons can be transferred efficiently from Photosystem II to plastoquinone without the involvement of cytochrome b-559 as an intermediate. These results indicate that it is unlikely that high potential cytochrome b-559 functions as an obligatory redox component in the main electron transport chain joining the two photosystems.
SU-E-T-349: Variation in VMAT QA Pass Rate Caused by Detector Setup Errors

Purpose: To test the sensitivity of pass rates of Gamma Index to the detector setup errors in six degrees of freedom. Methods: VMAT (Volumetric Modulated Arc Therapy) treatment technique is used in our clinic on an Elekta Beam Modulator with a HexaPOD couch. The HexaPOD system is a robotic patient positioning platform with six degrees of freedom. ScandiDos Delta4 system is used for our VMAT patient QAs. Delta4 is a pseudo 3D diode detector array which is capable of calculating 3D Gamma Index. Seven prostate and four H&N VMAT treatment plans were delivered. The measurements were compared with the Pinnacle TPS calculations and the pass rates of Gamma Index were calculated. Then the HexPod couch was shifted or rotated either by 1 mm or 1 degree in any of the six degrees of freedom to simulate the setup errors, and the pass rates were re‐measured and re‐calculated. The criterion used for Gamma Index calculation was 3% and 3mm. A detector point is considered pass if the calculated Gamma Index is smaller than 1. Pass rates of Gamma Index with different detector setup errors in the six degrees of freedom were compared. Results: Regarding the rotational setup error of different directions, the changes of pass rates of Gamma Index are significantly different (p 0.1). Conclusions: Although 1 mm or 1 degree machine‐type tolerance was recommended by AAPM TG reports, they don't translate to the same amount of changes in pass rates of Gamma Index for VMAT QA.
African American Women, AIDS, and Resiliency

ABSTRACT Ongoing shifts in the populations affected by the AIDS epidemic are reflected in the increasing proportion of AIDS cases in women-particularly women of color. While African American women represent approximately 13% of the U.S. female population, in 2000, 63% of all reported AIDS cases in women in the United States were among African American/non-Hispanic women. Despite these statistics, relatively few studies in the area of HIV research target African American women exclusively. As part of a larger study, we asked 105 African American women to describe in their own words how their lives have changed since becoming HIV positive. Despite multiple past and current stressors, the majority of participants provided responses that were decidedly positive. Clinical implications as well as future research directions based on these findings are discussed.
Scaffolding Infants’ Play Through Empowering and Individualizing Teaching Practices

Research Findings: Using a qualitative research approach, this article explores teachers’ roles as scaffolders of infants’ play and the changing nature of their individualized support for infants’ learning and development through play in an infant group care setting. Three infant teachers in a child care center were followed over 3 months. Observations, interviews, ongoing conversations, e-mails, and reflective notes were used as data sources. Findings revealed that the teachers thought deeply about their roles as supporters of infants’ play, and they made intentional choices in scaffolding infants’ play. Each teacher's ways of empowering infants in play were grounded in her views of infants as learners and were individualized to accommodate children's unique learning styles and personalities. Practice or Policy: This study provides a window into the ways in which teachers working with the youngest children can set the stage for later learning.
Change management patterns in software product lines

Establishing effective change management practices to prevent uncontrolled evolution of the product platform.
Phase-noise measurement of a 670 GHz source

We present phase-noise measurements in support of terahertz electronics. Using digital phase-noise measurement techniques and an even-harmonic mixer, we achieve a phase-noise measurement system in waveguide (WR1.5). At 670 GHz an upper bound of this system's noise floor is found to be −20, −40, and −60 dBc/Hz at 1, 100, and 10000 Hz offsets, respectively. In addition, a commercial, low-phase-noise, 670 GHz source is measured at offset frequencies from 0.1 Hz to 1 MHz.
The Ultrastructure of Functional Mouse Adrenal Cortical Tumor Cells in vitro

Cells derived from a transplantable mouse adrenal cortical tumor maintain their differentiated function in vitro and secrete steroids in response to ACTH and other stimulatory agents. The cell line has been widely employed for various biochemical investigations but there have been few attempts to correlate this work with morphologic data. This communication describes the electron microscopic appearance of the tumor transplant in vivo and primary cultures derived from it at various intervals after the cells are placed in culture. Tumor cells in vivo bear considerable resemblance to normal adult mouse adrenal cortical cells. Organelles generally considered to be directly involved in steroid biosynthesis (mitochondria, smooth endoplasmic reticulum and lipid droplets) are not drastically altered. Certain modifications of the vasculature and cell membrane, seemingly related to steroidogenesis, are present in both the tumor and normal adrenal cortex. Within 2 days after the tumor cells are introduced to culture, their cytoplasm assumes a more simplified appearance. Smooth endoplasmic reticulum is less conspicuous and free ribosomes and polysomes are very abundant. Mitochondrial inner membranes are reorganized from a saccular arrangement in the cells in vivo into distinct lamellar cristae. The tumor cells now resemble undifferentiated embryonic adrenal cells, or cultured adrenal cells from various mammalian sources which have dedifferentiated in the absence of ACTH. In their morphologically unspecialized state, the normal cells are incapable of functional responses to ACTH. In contrast, the cultured, dedifferentiated tumor cells respond within minutes to this hormone and can demonstrate 5–20 fold increases in their basal steroid output. These data suggest that substantial steroidogenic activity can occur although the characteristic appearance of adrenal mitochondria is absent.
Comment on "Relativistic effects of light in moving media with extremely low group velocity"

A Comment on the Letter by U. Leonhardt and P. Piwnicki, Phys. Rev. Lett. 84, 822 (2000). The authors of the Letter offer a Reply.
Field observation on death feigning: a unique hunting behavior by the predatory cichlid, Haplochromis livingstoni , of Lake Malawi

Haplochromis (=Cyrtocara) livingstoni, one of the predatory cichlids of the sand community of Lake Malawi, Africa, occurs at a density of 1.3 individuals per hectare. They are territorial, defending areas 15 m wide by 40 m long along the interface of sand andVallisneria weed beds. Individuals use a ‘death feigning’ hunting pattern to capture prey. From a position of lying on their sides semiburied in the sand, these fish attack small cichlids. During four hours of SCUBA observations three successful attacks from this position were seen. After an attack the small cichlids scatter and the predator moves on toward a new aggregation of fish where it again plays dead. Individuals feign death an average of seven times per thirty minutes watch. Death feigning behavior is initiated in two ways. The fish either 1) is stationary with its ventral surface on or close to the sand, and then falls onto its side, or 2) drops from the water colum into `lying on side' position. The initial behavioral actions of the latter method are similar to chafing behavior. But instead of chafing the sand and rising again off the bottom, the fish plows into the sand and remains immobile. These data further add to the evidence that cichlids are remarkably flexible in their feeding behavior.
Implementing Home Energy Rating Systems

Abstract We evaluate the implementation of home energy rating and labelling programs (HERS) that are being conducted around the country. We examine the nature of different implementation problems and the kinds of strategies that have been used to deal with them to ensure the effective penetration of HERS to all HERS users. Based on our evaluation of 34 home energy rating and labelling programs, HERS that were actively marketed, had a comprehensive appreciation of the market, were adaptive to the needs of particular users, and included user participation in the operation and revision of the program were more successful in terms of penetration rates and in improving the energy efficiency of the older housing stock. Where successful, HERS have penetrated an estimated 40% of the new construction market and 20% of existing construction, and energy savings have ranged from 10 to 50%.
Accuracy of cardiokymography during exercise testing: Results of a multicenter study

To determine the diagnostic accuracy of cardiokymography, recorded 2 to 3 minutes after exercise, 617 patients undergoing cardiac catheterization were evaluated from 12 participating centers using a standardized protocol. Adequate cardiokymographic tracings, which were obtained in 82 % of patients, were dependent on the skill of the operator and on certain patient characteristics. Of the 327 patients without prior myocardial infarction who had technically adequate cardiokymographic and electrocardiographic tracings, 166 (51%) had coronary disease. Both the sensitivity and specificity of cardiokymography (71 and 88%, respectively) were significantly greater than the values for the exercise electrocardiogram (61 and 76%, respectively, both p Cardiokymography was most helpful in those patients in whom the posttest probability of coronary disease was between 21 and 72% after exercise electrocardiography. In these patients a concordantly positive cardiokymographic result increased the probability of coronary disease to between 67 and 100%, whereas a negative response decreased it to between 12 and 15%. In the subgroup of 102 patients undergoing concomitant exercise thallium testing, the sensitivity and specificity for the thallium scintigraphy (81 and 80%, respectively) were similar to the values for cardiokymography (72 and 84%, respectively; differences not significant). Thus, cardiokymography performed during exercise testing improves the diagnostic accuracy of the electrocardiographic response and provides an additional and cost-effective indicator of myocardial ischemia.
Morality and conformity: The Asch paradigm applied to moral decisions

Morality has long been considered an inherent quality, an internal moral compass that is unswayed by the actions of those around us. The Solomon Asch paradigm was employed to gauge whether moral decision making is subject to conformity under social pressure as other types of decision making have been shown to be. Participants made decisions about moral dilemmas either alone or in a group of confederates posing as peers. On a majority of trials confederates rendered decisions that were contrary to judgments typically elicited by the dilemmas. The results showed a pronounced effect of conformity: Compared to the control condition, permissible actions were deemed less permissible when confederates found them objectionable, and impermissible actions were judged more permissible if confederates judged them so.
Moments of two-time spin-pair correlation functions for a one-dimensional anisotropic Heisenberg model at infinite temperature

Abstract The first ten moments of the infinite-temperature space and frequency dependent two-spin correlation functions, ƒ x r (ω) and ƒ z r (ω) are obtained for the one-dimensional anisotropic Heisenberg model for r = 0 and r = 1. These are compared with those previously known.
Development models, sustainability and occupational and environmental health in the Americas: neoliberalism versus sustainable theories of development

This article describes the inherent contradiction between competitive capitalism and the pursuing of the "three bottom lines": 1) economic prosperity, 2) environmental quality (including the workplace) and 3) social justice. An alternative, genuine, sustainable approach to development; the Integrated Human Ecosystem Approach will be described and contrasted with neoliberal development. The IHE approach was developed by The International Development Research Center of Canada in 2001. In this approach, the triple bottom line is not a simple tool for neoliberal development, but the focus of allocation and management of resources for sustainable development. The acquisition of only state power by governments opposed to neoliberalism is necessary but not sufficient condition to successfully find a human alternative to the market ideology. A road map needs to be developed in which a clear definition of technologies that permit the acquisition and implementation of an alternative ideology to achieve "social power." The IHE model provides developing countries with the basis for that ideology.
Surface-associated vesicles in retinal arterioles and venules.

The surface-associated vesicles in retinal arterioles and venules were studied after fixation in glutaraldehyde-tannic acid or after intravitreal injection of peroxidase or lactoperoxidase. The vesicles were concentrated along the abluminal (basal) surface of the endothelial cells and along the plasma membranes of smooth muscle cells in arterioles and of pericytes in post-capillary venules. They were rarely encountered in the deeper regions of these cells. In perpendicular sections through the cell surface the majority of vesicles were in continuity with the plasma membrane whereas in tangential sections, they appeared to lie “free” in the cytoplasm. All such vesicles were labeled after exposure to tannic acid or to the heme-proteins. Peroxidase-reaction product was never seen in the lumen of the vessels. These observations suggest that the surface vesicles in endothelial cells, smooth muscle cells and pericytes are invaginations of the plasma membrane and are thus not involved in the transcytosis or endocytosis of proteins. The vesicles in the latter two cell types may be involved in some aspect of contractility rather than pinocytosis.
Contemporary Mohs surgery applications.

Purpose of reviewThe incidence of cutaneous malignancies continues to rise and it is likely that the majority of skin cancers referred to otolaryngologists will have characteristics that necessitate a more complex and aggressive approach. Mohs micrographic surgery is a tissue-sparing technique that
[Comment on] Space Physics review articles

I read with approval the announcement (Eos, January 23, 1990, p. 219) that the Journal of Geophysical Research-Space Physics will publish specialized review articles in space physics, filling the unfortunate void left by the changed format of Reviews of Geophysics. Review articles provide newcomers to a subject with an up-to-date introduction, while providing old hands in the field with a useful reference source. However it is unfortunate that JGR-Space Physics will, like Reviews of Geophysics itself, be publishing reviews by invitation only. This regressive policy is doubly wrong. First, there are currently not too many but rather too few widely available review articles in our field; and thus artificial limitations are inappropriate (and unnecessary). Reviews of Geophysics has never managed to publish more than a handful of space physics reviews in a year, and that many only in the quadrennial reports to IUGG. In a field where accurate predictions are rare, one that is almost certain to succeed is that the editor(s) of JGR-Space Physics will have no difficulty whatsoever in limiting the number of review articles to 12 per year.
Recent advances in molecular level understanding of adhesion, friction and lubrication

Abstract In order to investigate the mechanism of boundary friction, adhesion and friction experiments were carried out with a variety of surfactant-monolayer-coated surfaces using the surface forces apparatus. The friction forces were measured as a function of monolayer coverage and phase state, load, temperature, shear rate and relative humidity. We report on two important findings. (i) Stick-slip motion can occur not only between a “static” and a “kinetic” state but also between a static or kinetic state and some “superkinetic” state that exhibits ultralow friction. (ii) The friction coefficient is not directly correlated with adhesion but rather with the adhesion hysteresis, which is a measure of the energy dissipated during an irreversible adhesion ( e.g. loading-unloading) cycle. We also conclude that chain interdigitation is the most important molecular mechanism that gives rise to “boundary” friction and adhesion hysteresis of monolayer-coated surfaces.