cssi/SciSciGPT-SciSciNet huggingface dataset:
Aortic valve stenosis in community medical practice: Determinants of outcome and implications for aortic valve replacement

Objective To define the objective and subjective measures of aortic stenosis (AS) severity linked to survival after diagnosis in community practice. Methods All 360 Olmsted County, Minnesota residents (74 ± 14 years; 44% men) with AS diagnosed from 1988 to 1997 by echocardiography and without life-threatening comorbid conditions were enrolled. The presentation at first diagnosis, outcomes (mortality, heart failure, cardiac surgery), and coherence of guideline-based criteria for severe AS were analyzed. Results The presentation was challenging. Cardiac symptoms were frequent (59%) and unassociated with the AS severity (all P > .13). Of the patients with severe AS, as determined by a valve area less than 1.0 cm 2 , 67% had low gradient AS (≤40 mm Hg). An aortic valve area less than 1.0 cm 2 was the only objective measure independently determining survival (adjusted risk ratio, 1.81; 95% confidence interval [CI], 1.19–2.70; P P 2 (risk ratio, 1.78; 95% CI, 1.33–2.35; P P = .02). Aortic valve replacement, ultimately performed in only 45% of those with an aortic valve area less than 1.0 cm 2 , reduced mortality (risk ratio, 0.61; 95% CI, 0.39–0.94; P = .02) and heart failure (risk ratio, 0.29; 95% CI, 0.13–0.64; P Conclusions In community practice, AS affects elderly patients, and its presentation is challenging owing to the high frequency of low-gradient severe AS despite a normal ejection fraction and because symptoms are frequently not specific to AS. Consequently, aortic valve replacement is seldom performed despite its considerable benefit. Physicians should be aware that an aortic valve area of less than 1.0 cm 2 predicts for unfavorable outcomes, irrespective of symptoms or gradient. Thus, such patients should undergo a thorough evaluation to detect those who could benefit from aortic valve replacement, despite their challenging presentation.
Supercritical water oxidation of the PCB congener 2-chlorobiphenyl in methanol solutions : A kinetic analysis

Incineration is commonly used to destroy polychlorinated biphenyl (PCB) wastes, but this method of treatment is not ideal for all mixed liquid wastes, especially those containing radioactive materials. Therefore, other remediation technologies are needed to efficiently treat these waste forms. This study examined the supercritical water oxidation (SCWO) of 2-chlorobiphenyl (2-PCB), using hydrogen peroxide as the oxidant and methanol as a cosolvent at 2 vol %. Kinetic studies were carried out in a plug flow reactor at temperatures from 686 to 789 K and a pressure of 250 bar, with reactor residence times ranging from 1.1 to 5.8 s. Least-squares regression of the collective reaction rate data revealed that 2-PCB exhibited second-order kinetics, with an Arrhenius frequency factor, A, equal to 10(18.2+/-2.3) L x mol(-1) x s(-1) and activation energy, Ea, of 181.7 +/- 33.2 kJ/mol. The primary organic reaction products from the SCWO of 2-PCB were biphenyl at low temperatures (<700 K) and CO2 at elevated temperatures. No dioxins or chlorinated dibenzofurans were ever detected in any of the effluent samples. Additional experiments with higher organic feed concentrations (4 vol %) illustrated how the exothermic nature of the organic oxidation reactions can be used to render the process self-sustaining. Finally, SCWO destruction rates greater than 99.98% were achieved for a simulated PCB-contaminated job control waste similar to that encountered at many U.S. Department of Energy sites.
Regulation of Matrix Metalloproteinase-19 Messenger RNA Expression in the Rat Ovary

Matrix metalloproteinases (MMPs) are instrumental in the constant tissue remodeling in the ovary. An induction of MMP-19 mRNA in periovulatory follicles has been reported in mouse ovaries. However, little is known about MMP-19 expression during the follicular and luteal periods or about the ovarian regulation of MMP-19 mRNA expression. We examined the expression pattern of MMP-19 mRNA during various reproductive phases and the periovulatory regulation of MMP-19 mRNA in the rat ovary. In gonadotropin-primed, immature rat ovaries, levels of MMP-19 mRNA transiently increased during both follicular growth and ovulation. The MMP-19 mRNA was localized to the theca-interstitial layer of growing follicles and to the granulosa and theca-interstitial layers of periovulatory follicles. A similar expression pattern of MMP-19 mRNA in periovulatory follicles was observed in ovaries from naturally cycling adult rats. Accumulation of MMP-19 mRNA was detected in regressing corpus luteum. The regulation of MMP-19 mRNA expression during the periovulatory period was investigated via in vivo studies and through in vitro culture studies on follicular cells. The hCG-induction of MMP-19 mRNA was mimicked by treating granulosa cells, but not theca-interstitial cells, from preovulatory follicles with LH or activators of the protein kinase (PK) A or PKC pathways. Cycloheximide blocked the LH- or forskolin-induced MMP-19 mRNA expression, demonstrating the requirement for new protein synthesis. In contrast, blocking activation of the progesterone receptor or prostaglandin synthesis had no effect on the increase in MMP-19 mRNA expression. In conclusion, the induction of MMP-19 mRNA suggests an important role of this proteinase during follicular growth, ovulation, and luteal regression.
Likelihood as approximate pivotal distribution

SUMMARY For a single-parameter curved exponential family, it is shown that the conditional distri- bution of the maximum likelihood estimator is the normalized likelihood function, except for a relative error proportional to inverse sample size. Recently it has been shown (Efron & Hinkley, 1978; Peers, 1978) that there is a conditional normal approximation for the distribution of the maximum likelihood estimator in the one- parameter case. This conditional normal approximation uses an observed characteristic of the likelihood as an approximate variance. In principle the approximation is unnecessary for the special case of estimating a location parameter, because Fisher (1934) derived the exact, fully-informative conditional distribution of the maximum likelihood estimator. That distri- bution is the normalized likelihood function. In this paper we present theoretical evidence that Fisher's special case result is a good approximation in general. Specifically, let lik (0) denote the likelihood for a sample of size n from a curved exponential family distribution indexed by a single parameter 0 and let 6 denote the maximum likelihood estimator. Then we find that the probability density of the pivot #- 0, conditional on a natural approximate ancillary a, is
Prolactin Drives Estrogen Receptor-α-Dependent Ductal Expansion and Synergizes with Transforming Growth Factor-α to Induce Mammary Tumors in Males

Male breast cancer is rare and has been the focus of limited research. Although the etiology is unclear, conditions increasing circulating prolactin (PRL), as well as estrogen, increase the risk of tumorigenesis. We modeled exposure to elevated PRL in transgenic mice, using the mammary-selective, estrogen-insensitive promoter neu-related lipocalin (NRL), to drive PRL expression. Male NRL-PRL mice did not develop mammary tumors. However, in cooperation with the well-characterized oncogene transforming growth factor-α (TGF-α), PRL induced mammary tumors in 100% of male bitransgenic mice. Similar to disease in human males, these tumors expressed variable levels of estrogen receptor-α (ER-α) and androgen receptors. However, carcinogenesis was not responsive to testicular steroids because castration did not alter latency to tumor development or tumor ER-α expression. Interestingly, both NRL-TGF-α/PRL and NRL-PRL males demonstrated increased ductal development, which occurred during puberty, similar to female mice. This outgrowth was diminished in NRL-PRL males treated with ICI 182,780, suggesting that PRL enhances ER-mediated growth. Treatment of MCF-7-derived cells with PRL increased phosphorylation of ER-α at residues implicated in unliganded ER-α activity. Together, these studies suggest that PRL expands the pool of cells susceptible to tumorigenesis, which is then facilitated by PRL and TGF-α cross talk. Activation of ER-α is one mechanism by which PRL may contribute to breast cancer and points to other therapeutic strategies for male patients.
Trajectories of an atomic electron in a magnetic field

Classical trajectories of an atomic electron in a magnetic field are calculated for various values of the field strength $B$. Qualitative properties of these trajectories are examined. With use of a scaling law, it is shown that the equations of motion can be written in a form such that they depend upon only one parameter, which may be regarded as a reduced angular momentum (proportional to ${L}_{z}{B}^{\frac{1}{3}}$). For small values of this parameter there is an "elliptical regime" in which the trajectory may be regarded as a Kepler ellipse with orbital parameters that evolve slowly in time. For large values of the parameter there is a "helical regime" in which the electron circles rapidly around a magnetic field line and bounces slowly back and forth along the field. Between these two regimes there is an irregular regime, with "chaotic" orbits and a "transition regime" in which the trajectories can be described in oblate spheroidal coordinates. Bound states persist even at energies above the escape energy, provided that the angular momentum (or field strength) is sufficiently large. With use of action-variable quantization, some formulas for semiclassical energy eigenvalues are given for regimes where the trajectories are regular.
The American Crucible: Slavery, Emancipation and Human Rights, Robin Blackburn, London: Verso, 2011*

Abstract Plantation slavery in the New World, in particular its relationship to the emergence of capitalism in Europe and North America, has long been a subject of debate and discussion among historians and social scientists. While there are literally thousands of monographs studying various aspects of chattel slavery in the US South, the Caribbean and Brazil, only a handful of works attempt to provide a synthetic account of its rise and decline from the sixteenth through nineteenth centuries. Few scholars, on the Left or Right, have made as profound a contribution to such a history as Robin Blackburn. Blackburn’s latest work, The American Crucible: Slavery, Emancipation and Human Rights, does not simply summarise and update his earlier work, but extends his analysis to the rise and decline of ‘second slavery’ in nineteenth-century Cuba, Brazil and the US South. The American Crucible provides a multi-causal explanation of the origins and abolition of New World plantation slavery, examining the complex interactions between the rise of capitalism, political crises in the metropolitan countries, the transformation of popular and elite attitudes toward slavery, and the struggles of the slaves themselves. However, Blackburn’s inability to grapple with the specific structure and dynamics of capitalist and slave social-property relations, and their changing historical relationship, weakens key elements of his analysis.
The effect of an orally active leukotriene D4/E4 antagonist, LY171883, on antigen-induced airway responses in allergic sheep

Abstract Leukotriene (LT) D 4 is a putative mediator of allergic asthma: inhaled LTD 4 produces early and late increases in specific lung resistance (SR L ) and slows tracheal mucus velocity (TMV) similat to inhaled antigen. In this study we examined the effects of an orally active LTD 4 /LTE 4 antagonist, LY171883 [1- Phenyl>Ethanonel], on early and late changes in SR L and TMV following airway challenge with Ascaris suum antigen in conscious allergic sheep. SR L and TMV were measured before and up to 8 h and 24 h after antigen challenge after either LY171883 (30 mg/kg, p.o. 2 h before challenge) or placebo pretreatment. After placebo pretreatment antigen challenge resulted in significant early (483% over baseline) and late (221% over baseline) increases in SR L (n=9). LY171883 pretreatment, however, significantly reduced the early increase in SR L (163% over baseline) and blocked the late response. LY171883 did not prevent the antigen-induced fall in TMV from 5–8 h post challenge (n=6), but TMV recovered more rapidly in the drug trial returning to baseline values by 24 h. These results suggest that the generation of LTD 4 , and its metabolite LTE 4 , during airway anaphylaxis contributes to the early increase in SR L and is important for eliciting the late increase in SR L as well as contributing to the fall in TMV.
Position paper on operating systems for small systems: the UNIX operating system

Sixteen bit microcomputers appear likely to be a major factor in the 1980's, just as eight bit microcomputers have dominated the late 1970's. The operating system that appears most likely to monopolize these sixteen bit microcomputers is UNIX, from Bell Laboratories, or its look-alikes. We shall examine some reasons why this should be so, and evaluate constraints upon a sixteen bit computer which must provide satisfactory hardware support for UNIX. Since many sixteen bit processors are being designed and purchased now, such discussion is essential to assuring that these machines can properly support this popular operating system. At the outset we can assert that if a powerful and flexible microprocessor is used (such as the Zilog Z8000, Motorola 68000, Intel 8086 or DEC LSI 11/23), then the issues focus upon suitable memory management with sufficient address space and protection, and upon powerful DMA disk I/O that allows efficient swapping of process images with little overhead. More detailed discussion of these issues follows. First we shall examine some reasons why UNIX appears a likely contender for champion of the sixteen bit microcomputer operating systems.
Nuclear data sheets for A = 194*

Abstract Nuclear structure data for the A = 194 mass chain are compiled, and adopted level properties and decay schemes are presented. In addition, several problem areas are noted and discussed. These include β-intensities from 194Os decay, correlation of low-energy γ-transitions in 194Ir reported in thermal-neutron capture and 31-ms 194mIr decay, energies of metastable states in 194Ir, multipolarities for gamma rays from 31-ms 194mIr decay, B(E2)-values and g-factors for 194Pt levels.
Supersonic Flow over a Finite-Width Rectangular Cavity

Two-component and stereoscopic particle image velocimetry measurements have been acquired in the streamwise plane for supersonic flow over a rectangular cavity of variable width, peering over the sidewall lip to view the depths of the cavity. The data reveal the turbulent shear layer over the cavity and the recirculation region within it. The mean position of the recirculation region was found to be a function of the length-to-width ratio of the cavity, as was the turbulence intensity within both the shear layer and the recirculation region. Compressibility effects were observed in which turbulence levels dropped, and the shear layer thickness decreased as the Mach number was raised from 1.5 to 2.0 and 2.5. Supplemental measurements in the crossplane and the planform view suggest that zones of high turbulence were affixed to each sidewall centered on the cavity lip, with a strip of turbulence stretched out across the cavity shear layer for which the intensity was a function of the length-to-width ratio. T...
Pharmacology of angiotensin converting enzyme inhibitors: A review

Two angiotensin converting enzyme inhibitors are currently available for clinical use. Captopril, a sulfhydryl-containing compound, is a direct acting enzyme inhibitor. Enalapril is a non-sulfhydryl pro-drug that requires enzymatic conversion to enalaprilic acid, a potent angiotensin converting enzyme inhibitor. Both drugs lower blood pressure, suppress blood pressure response to angiotensin I infusion, and elevate plasma renin activity. Enalapril bioavailability is unaffected by food, whereas captopril availability is suppressed by food. Dose adjustments are necessary for patients with congestive heart failure and renal failure.
Hegemonic discourse revisited

It is necessary to trust in the oppressed and in their ability to reason. Whoever lacks this trust will fail to initiate (or will abandon) dialogue, reflection, and communication, and will fall into using slogans, communiques, monologues, and instructions. Paulo Freire (1970: 53)
Criterion validity of a coping measure

A paucity of evidence for the validity of coping questionnaires prompted investigation of the Coping Strategy Indicator (CSI; Amirkhan, 1990), a self-report measure of three fundamental modes of coping that has already demonstrated considerable psychometric strength. Three tests of criterion-related validity were performed, with variations in both the types of stressors and respondents sampled. In the first, CSI scores were found to correspond to coping choices made under the threat of electric shock in a laboratory. In the second and third, the CSI correctly identified coping patterns associated with participation in educational and therapeutic programs in more natural settings. Results confirmed the validity and wide applicability of the CSI and suggested avenues for future basic and applied research.
Pneumatic and Semipneumatic Plugs for Large-Diameter Rumen Fistulas in Cattle

Summary Detailed fabrication procedures for large-diameter pneumatic and semipneumatic fistula-plugs are described. They were found, over an 18-mo. period, to be exceptionally durable, moderate in cost, and could be removed and replaced with little discomfort to the animal. They did not irritate the fistula, and required a minimum of attention (no fistula-plug care was required by four fistulated animals during a 4-mo. period). A fistulation technique which produces a uniform fistula particularly suited to the plugs also is described. The fistulas thus produced, in the presence of the rubber plugs, showed little or no swelling immediately postoperative or during healing, and retained their size and shape satisfactorily during an 18-mo. period. No deaths from fistulation occurred.
The effect of niobium additions on the fracture of Ni19Si-based alloys

Abstract The mechanical properties of Ni19Si polycrystals alloyed with niobium and boron were investigated by microhardness and tensile tests. The microstructure change caused by the addition of niobium was also examined by X-ray diffraction, high temperature differential scanning calorimetry, scanning electron microscopy and transmission electron microscopy. The results reveal that the cast Ni19Si x Nb alloys of two phases, α (f.c.c.) and β(Li 2 ). The addition of niobium, which substitutes for silicon in these alloys, will decrease their melting points, but increase their hardness and yield strengths. This strengthening effect arises owing to the lattice expansion of the β phase matrix by the addition of niobium and the hardening by the hard niobium-rich precipitates in the β matrix. In addition, it appears that with 5 at.% Nb, the β phase formed directly from the melt, instead of a liquid-solid or solid-solid reaction. The fracture behavior of the Ni-19Si3.5Nb alloy with boron doping also exhibits significant ductility improvement.
Statistical testing of software based on a usage model

In statistical testing, a model is developed to characterize the population of uses of the software, and the model is used to generate a statistically correct sample of all uses of the software. A software ‘usage model’ characterizes the population of intended uses of the software in the intended environment. Statistical testing based on a software usage model ensures that the failures that will occur most frequently in operational use will be found early in the testing cycle. The usage model is based on the software specification. The model can be developed in parallel with the software, thus shortening the elapsed time required to develop the deliver software. Usage modeling has been demonstrated to be an activity that improves the specification, gives an analytical description of the specification, quantifies the testing costs and, with statistical testing, provides a basis from which inferences of software reliability may be made. This paper describes the justification for statistical testing of software using a usage model, describes procedures for developing and using a usage model and discusses several usage modeling issues and recent advances in usage model applications.
Fragment-Shell Influences in Nuclear Fission

Potential-energy surfaces and shell-correction-energy surfaces for nuclei in the $A\ensuremath{\simeq}200$ region and for actinide ($A\ensuremath{\gtrsim}230$) have been calculated in the improved two-center model. These surfaces are shown in a two-dimensional representation as a function of the elongation and the constriction of the nuclear shape. Both the ground-state shell corrections and the fission barriers in the $A\ensuremath{\cong}200$ region agree well with experiment. It is found that the saddlepoint position in this region is shifted significantly towards smaller deformations compared with the liquid-drop-model prediction, this shift arising from a very pronounced valley in the shell-correction surface at the position of the liquid-drop-model saddle point. The implications of this finding for a nuclear mass formula and for the application of the liquid-drop model to fission of these nuclei are discussed. In both mass regions ($A\ensuremath{\cong}200 \mathrm{and} A\ensuremath{\gtrsim}230$) the shell corrections alone show pronounced structure which changes slowly with mass number. At small deformations, up to the region of the second maximum in the potential, this structure is determined by the compound-nucleus shell structure. At larger deformations this structure is shown to arise from the shell structure of the nascent fragments, thus establishing the importance of fragment shells early in the fission process for the entire mass range $A\ensuremath{\gtrsim}200$. As a consequence of these studies the regions of validity for the liquid-drop model in describing nuclear fission are explained. Finally, it is shown that the recently observed symmetry in the mass distribution of $^{257}\mathrm{Fm}$ is due to the approach to the nucleus $^{264}\mathrm{Fm}$, which can split symmetrically into the two energetically strongly favored $^{132}\mathrm{Sn}$ nuclei.
Degrees of computational complexity

We consider a measure @F of computational complexity. The measure @F determinesa binary relation on the recursive functions; F is no harder to compute than G iff for every index g of G there is an index f of F such that for nearly all x, the difficulty of f at x (as measured by @F) is no more than the difficulty of g at x. The corresponding symmetric relation is an equivalence relation, and the set of equivalence classes (the degrees of complexity) is partially ordered. In this paper we give a simple proof of a result of McCreight: An arbitrary countable partial ordering can be embedded in this ordering of degrees of complexity.
Ultrahigh temperature water gas shift catalysts to increase hydrogen yield from biomass gasification

Abstract Noble metal (Rh, Pt, Pd, Ir, Ru, and Ag) and Ni catalysts supported on CeO2–Al2O3 were investigated for water gas shift reaction at ultrahigh temperatures. Pt/CeO2–Al2O3 and Ru/CeO2–Al2O3 demonstrated as the best catalysts in terms of activity, hydrogen yield and hydrogen selectivity. At 700 °C and steam to CO ratio of 5.2:1, Pt/CeO2–Al2O3 converted 76.3% of CO with 94.7% of hydrogen selectivity. At the same conditions, the activity and hydrogen selectivity for Ru/CeO2–Al2O3 were 63.9% and 85.6%, respectively. Both catalysts showed a good stability over 9 h of continuous operation. However, both catalysts showed slight deactivation during the test period. The study revealed that Pt/CeO2–Al2O3 and Ru/CeO2–Al2O3 were excellent ultrahigh temperature water gas shift catalysts, which can be coupled with biomass gasification in a downstream reactor.
Salmonellae interactions with host processes

Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.
Application of the homomorphic deconvolution for the separation of TDR signals occurring in overlapping time windows

The homomorphic transformation is used to separate a time domain reflectometry (TDR) signal into its rapidly and slowly varying components, respectively. The separation (deconvolution) technique is successful in the case where the multiple reflections cannot be viewed in nonoverlapping time windows as is required by the conventional TDR method.
EFFECT OF SEED DIMORPHISM ON THE DENSITY‐DEPENDENT DYNAMICS OF EXPERIMENTAL POPULATIONS OF ATRIPLEX TRIANGULARIS (CHENOPODIACEAE)

The importance of seed size and density in determining individual plant performance and plant population dynamics in experimental populations of the halophyte Atriplex triangularis was studied. Two distinct seed morphs-large, light seeds and small, dark seeds-are produced by individual A. triangularis plants. Experimental populations consisting of seed size monocultures (large or small seeds) and seed size mixtures were established at three different densities, and the time of germination, plant size, plant survivorship, and plant fecundity were monitored. Marked variation in time of germination was observed among treatments and between seed sizes, but germination within any given treatment occurred over a fiveto ten-day period. Large seeds produced larger plants than small seeds did, and this dichotomy was maintained over the course of the entire experiment. Germination date and seed size interacted such that larger plants grew from seeds which germinated earlier than those which germinated later, regardless of seed size. Germination date had a more pronounced effect than seed size did on plant mortality in high density populations. At high density, large seed monocultures experienced greater mortality than small seed monocultures did, but in seed size mixtures, the mortality was evenly distributed between plants from the two seed sizes. Regardless of density conditions and parentage, large and small seeds were produced in equal proportion by the plants. Total seed production, however, was dramatically affected by plant density, and to a lesser degree by germination date. Although seed size effects alone did not appear to affect directly final plant biomass and fecundity, effects of seed size early in ontogeny may have contributed to differences
Actor-Network Theory and the ethnographic imagination: An exercise in translation

The publication of Bruno Latour’s Reassembling the Social: An Introduction to ActorNetwork-Theory (2005b) was a remarkable event, which capitalized on the steadily growing interest in the works of Latour, Callon, Law, Mol, and others assembled, willfully or not, under the label “Actor-Network Theory” (ANT). For those unfamiliar, Reassembling the Social charges that sociology’s over reliance on a particular metaphor of “the social” has blinded it from the much messier and heterogeneous practices of association that constantly make and remake what we have lazily come to think of as “society.” Turning towards its etymology, Latour defines “the social not as a special domain, a specific realm, or a particular sort of thing, but only as a very peculiar movement of re-association and reassembling” (7). Marshaling over two decades of research and theorizing—his own and that of his colleagues—Latour makes the call for carefully descriptive accounts of this movement. At times a polemic and sweeping broadside against what Latour dismissively calls “traditional” and “critical” sociology, at other times an accessible review of the ANT corpus, and still at others an elaboration of its “amodern” philosophical underpinnings, the book ends with what seems like false modesty:
Monolayer penetration by a charged amphiphile: equilibrium and dynamics

Abstract The penetration of a soluble surfactant into an insoluble monolayer provides a means of understanding intermolecular interactions and their impact on equilibrium and dynamic surface pressures. In this paper, the adsorption of an ionic surfactant into an insoluble monolayer is studied theoretically and numerically. The equilibrium increase in surface pressure Δ π caused by the surfactant adsorption is derived for a Davies adsorption isotherm using a Gibbs adsorption equation properly constrained for the presence of the insoluble monolayer. The dynamic surface pressure is studied using this surface equation of state for Δ π assuming either diffusion controlled or mixed kinetic-diffusion controlled mass transfer. Several trends are predicted with variations of the surface coverage of the insoluble component, the concentration of soluble surfactant and the ionic strength of the surfactant subphase. Experiments in the literature have shown that, for an uncharged monolayer, Δ π at equilibrium is greater the higher is the surface coverage of the insoluble monolayer into which the ionic, soluble surfactant adsorbs. Our results show that this trend can be attributed to the role of the insoluble component in presenting an entropic barrier to adsorption, thereby reducing the repulsive surface charge density at a given net surfactant coverage, allowing more surfactant to adsorb. Greater surface pressures result. Signature trends in the timescales for diffusion controlled mass transfer of an ionic surfactant as a function of initial surface coverage of the insoluble monolayer are derived. This timescale is longer than predicted by simply accounting for the area blocked by the insoluble component using a Langmuir argument, and approaches the Langmuir argument with increasing ionic strength. For mixed kinetic-diffusion controlled mass transfer, because the insoluble component blocks interface, it reduces the amount of surfactant that can adsorb. This decreases the diffusion timescale, and allows adsorption-desorption kinetics to play a controlling role. Since electrostatic repulsion reduces the adsorption of the soluble component, kinetics also play a stronger role the lower is the ionic strength or the higher the surfactant valence. Considering a surfactant with fixed physicochemistry, a shift of controlling mechanism from diffusion control to kinetic control is demonstrated with increasing bulk concentration, surface charge density or surface coverage of insoluble component.
Metal mobility in sediment-covered ridge-crest hydrothermal systems: experimental and theoretical constraints

Abstract The presence of sedimentary organic matter blanketing midocean ridge crests has a potentially strong impact on metal transport in hydrothermal vent fluids. To constrain the role of organic matter in metal mobility during hydrothermal sediment alteration, we reacted organic-rich diatomaceous ooze from Guaymas Basin, Gulf of California, and organic-poor hemipelagic mud from Middle Valley, northern Juan de Fuca Ridge, with seawater and a Na-Ca-K-Cl fluid of seawater chlorinity, at 275° to 400°C, 350 to 500 bars, and initial fluid: sediment mass ratios ranging from 1.6 to 9.8. Reaction of these fluids with both sediment types released CO2 and high concentrations of ore-forming metals (Fe, Mn, Zn, Pb) to solution. Relatively low concentrations of Cu were observed in solution and likely reflect the reducing conditions that resulted from the presence of sedimentary organic matter. Both the concentrations of CO2 and dissolved metals were lower in fluids reacted with Middle Valley sediment compared with aqueous concentrations in fluids reacted with Guaymas Basin sediment. During alteration of both sediment types, metal concentrations varied strongly as a function of temperature, increasing by up to an order of magnitude over the 75°C range of each experiment. Major element fluid chemistry and observed alteration assemblages suggest that during hydrothermal alteration of organic-lean sediment from Middle Valley a feldspar-quartz-illite mineral assemblage buffered in situ pH. In contrast, data from the experimental alteration of organic-rich Guaymas Basin sediment suggest that a calcite-plagioclase-quartz assemblage regulated in situ pH. Fluid speciation calculations suggest that in situ pH during Guaymas Basin sediment alteration was lower than during alteration of Middle Valley sediment and accounts for the substantially greater metal mobility at a given temperature and pressure during the former experiment. Comparison of our results with the results of basalt alteration experiments indicate that except for Cu, hydrothermal sediment alteration results in equal or greater concentrations of ore-forming metals at a given temperature and pressure. Accordingly, the presence of ore-forming metals in fluids currently venting from sediment-covered hydrothermal systems at concentrations substantially lower than in fluids from bare-rock systems may reflect chemical reequilibration during subsurface cooling within the sediment pile.
Harnessing nanoparticles to improve toxicity after head and neck radiation.

Abstract This article reports the evaluation of cerium oxide (CeO 2 ) nanoparticles' ability to decrease xerostomia and radiation-induced dermatitis in mice after head and neck radiation. Mice were irradiated using an IC160 x-ray system. Two cohorts were included: (A) No-radiation and (B) 30 Gy/6 fractions, and were randomized into three groups: (1) saline, (2) 15 nM CeO 2 and (3) 15 μM CeO 2 . Stimulated salivary flow and radiation-induced dermatitis were evaluated post radiation. Stimulated sialometry demonstrated improved salivary production in all CeO 2 groups in comparison with controls (flow: 204 vs. 115 μL/10 minutes , P = 0.0002). One week post radiation, G-III dermatitis decreased in the 15 μM group in comparison with controls (10% versus 100% incidence, respectively). There was decreased skin hyperpigmentation at 12 weeks in the 15-μM group in comparison with 15-nM and non-CeO 2 groups (50%, 70%, and 90% G-II, respectively). This study suggests that CeO 2 may be radioprotective for salivary production and reduces G-III dermatitis and skin hyperpigmentation incidence. CeO 2 as radioprotectant may be a feasible concept during radiotherapy. From the Clinical Editor This study demonstrates in a mouse model that cerium oxide (CeO 2 ) nanoparticles may provide an important mechanism in preventing radiation induced xerostomia, a common complication of head and neck radiation treatments.
The Tennessee Better Schools Program: The Career Ladder

(1985). The Tennessee Better Schools Program: The Career Ladder. School Organisation: Vol. 5, No. 4, pp. 357-364.
Insights into the (1×1)-to-(2×1) phase transition of the α-Fe2O3() surface using EELS, LEED and water TPD

Abstract The (1×1)-to-(2×1) surface reconstruction of α-Fe2O3(0 1 2) (also known as the R-cut or ( 0 1 1 2 ) surface) was examined using low energy electron diffraction (LEED), electron energy loss spectroscopy (EELS) and temperature programmed desorption (TPD). The (1×1) surface is generated by heating in 5×10−7 Torr O2 at 750 K, followed by cooling in O2. The surface prepared in this manner exhibits a p(1×1) LEED pattern consistent with a bulk-terminated structure. EELS analysis of this surface shows a 2 eV bandgap consistent with that of hematite and little or no evidence for Fe2+ surface sites. In contrast, a (2×1) LEED pattern is observed after annealing the (1×1) surface in UHV at 950 K. The EELS spectrum of the (2×1) surface exhibits a prominent loss feature at about 1 eV, which is consistent with Fe2+ sites. The (2×1) surface prepared by annealing at 950 K does not possess a termination film of Fe3O4, as has been reported in the literature for the (0 0 1) surface, since the phonon spectrum remains consistent with that of α-Fe2O3. Both LEED and EELS detect the onset of the (1×1)-to-(2×1) reconstruction process to be at 700 K, whereas water TPD, which shows distinctively different desorption features for those two surface phases, detects the onset to occur at about 600 K. The (1×1)-to-(2×1) surface reconstruction process appears to be highly nucleated based on observations that the (2×1) LEED spots grow in during annealing without streaking and that coverage-dependent water TPD for a half (1×1)–half (2×1) surface shows simultaneous filling of both (1×1) and (2×1) binding sites. Given that the reconstruction process is accompanied by reduction of Fe3+ surface sites to Fe2+ sites, the preference for growth of existing (2×1) domains over initiation of new (2×1) domains implies that the kinetics for hematite reduction (i.e., Fe2+ formation) are more favorable in the vicinity of other Fe2+ sites than in regions rich in Fe3+.
Equivalence between temporal frequency and modulation depth for flicker response suppression: analysis of a three-process model of visual adaptation

We analyze adaptation processes responsible for eliciting and alleviating flicker response suppression, which is a class of phenomena characterized by the selective reduction of visual response to the ac component of a flickering light. Stimulus conditions were chosen that would allow characteristic features of flicker response suppression to be defined and manipulated systematically. Data are presented to show that reducing the sinusoidal modulation depth of an 11-Hz stimulus can correspond precisely to raising the temporal frequency of a fully modulated stimulus. In each case there is a nonmonotonic relation between flicker response and dc test illuminance. The nonmonotonic relation cannot be explained by adaptation models that postulate multiplicative and subtractive adaptation processes followed by a single static saturating nonlinearity, even when temporal frequency filters are incorporated into such models. A satisfactory explanation requires an additional contrast gain-control process. This process enhances flicker response at progressively lower temporal response contrasts as the illuminance of a surrounding field increases.
Analysis of possible paleofecal samples from Pellejo Chico Alto, Peru: results and lessons

The analysis of four presumed paleofecal samples (coprolites) recovered from the Pellejo Chico Alto site in Peru is reported herein. The samples were processed using standard methods for paleofecal specimens but were discovered to be large pieces of intact tissue, rather than coprolites. While the results provided information regarding diet and cuisine at Pellejo Chico Alto, it also serves as an instructive lesson in the identification and analysis of paleofecal samples.
Stochastic networks as models of cognition: derivation of response time distributions using the order-of-processing method

Abstract Researchers in cognitive psychology have devoted a great deal of attention to the temporal nature of cognitive processes. Hypotheses are tested by comparing obtained and theoretical response time distributions for various experimental conditions. This paper extends and refines a method for deriving theoretically expected response time distributions, so that it can be applied under weaker assumptions and to a wider class of mental architectures. Specifically, the Order-of-Processing (OP) method, originally developed to analyze stochastic PERT networks, is extended to apply to much more general structures. The method is also extended to handle more general distributions of cognitive process durations than previously considered. As an example of the OP method, OP diagrams are constructed for models which are not representable as stochastic PERT networks—limited-capacity and self-terminating models of visual search.
Elastohydrodynamic rebound of spheres from coated surfaces

Experiments were performed to measure the rebound velocities of small plastic and metal spheres dropped from various heights onto a smooth quartz surface coated with a thin layer of viscous fluid. The spheres stick without rebounding for low impact velocities, due to viscous dissipation in the thin fluid layer. Above a critical impact velocity, however, the lubrication forces in the thin layer cause elastic deformation and rebound of the spheres. The apparent coefficient of restitution increases with the ratio of the Stokes number to its critical value for rebound, where the Stokes number is a dimensionless ratio of the inertia of the sphere to viscous forces in the fluid. The critical Stokes number required for rebound decreases weakly with increasing values of a dimensionless elasticity parameter which is a ratio of the viscous forces which cause deformation to the elastic forces which resist deformation. The experimental results show good agreement with an approximate model based on lubrication theory for undeformed spheres and scaling relations for elastic deformation.
Consumer Response to Retailers' Use of Partially Comparative Pricing

Abstract Consumers sometimes encounter a combination of comparative and noncomparative prices in the marketplace. For example, a grocer may employ signage that provides favorable price comparisons with those of a competitor for a portion of its products, a practice that the authors refer to as “partially comparative pricing.” The authors examine the effects of partially comparative pricing on consumer response and find that it has both desirable and undesirable effects. On the one hand, such pricing enhances consumers’ beliefs about the relative prices of comparatively priced products and about the retailer’s relative prices in general. On the other hand, such pricing also reduces consumers’ relative price beliefs about noncomparatively priced products and their intentions to purchase such products. The authors further show that the adverse influence of partially comparative pricing stems from consumers’ suspicions about why price comparisons exist for some, but not all, products. They also document how t...
Can electromagnetic augmentation reduce space launch costs

A ground-based electromagnetic (EM) acceleration system to provide a launch-to-orbit capability is described. A study was undertaken to determine if such a system could achieve a useful reduction in launch costs compared with current large chemical boosters, while increasing launch safety and reliability.
Microdetermination of calcium in biological materials

Abstract A simple reliable colorimetric method for microquantities of calcium using glyoxal bis(2-hydroxyanil) as a color reagent has been described. The method has been applied to serum, fresh muscle, and calcified tissue. Values obtained by this technique have been checked by other methods of analysis and the results support the reliability and accuracy of the method.
Use of vibratory cues for detection of insect prey by the sandswimming lizard Scincus scincus

Abstract The sandfish lizard, Scincus scincus, inhabits the Sahara Desert and spends most of its time buried in the sand. Laboratory experiments were performed to determine if Scincus can respond and orient to insects on the sand surface by detecting vibrations produced by movements of the insects. When buried, Scincus can detect and respond to crickets and mealworms moving over the surface at distances up to about 15 cm. These responses were guided by vibratory cues, not olfactory cues, as the lizards responded much less frequently to dead insects placed on the surface at equal distances. The lizards obtain directional information from the vibrations, and can localize the insects, orient toward them, and emerge from the sand to capture them. When walking on the surface of the sand, Scincus often displays a peculiar behaviour of plunging its head into the sand. Experiments determined that this behaviour aids lizards in detecting vibrations produced by insects moving through the sand, and presumably facilitates transmission of sand-borne vibrations to the inner ear.
Effect of LiCl pretreatment on cholinomimetic-induced seizures and seizure-induced brain edema in rats.

Abstract Male Sprague-Dawley rats received LiCl (5 mEq/kg; sc) or saline 24 h prior to injection of cholinomimetics. Physostigmine (PHY, 0.54–0.80 mg/kg), diisopropylfluorophosphate (DFP, 1.3–2.5 mg/kg), pilocarpine (PIL, 23–30 mg/kg), or saline was injected subcutaneously at time 0. Rats were observed for seizure activity for 2 h, survivors were killed 24 h later and edema was measured in samples from parietal and piriform cortices, dorsal thalamus, and hippocampus. None of the rats pretreated with saline had seizures when given doses of cholinomimetics alone. However, rats pretreated with LiCl had the following incidence of seizures: PHY 68%, DFP 71% and PIL 100%. Rats given cholinomimetic agents alone did not have brain edema. In contrast, all LiCl-pretreated rats that seized had pronounced brain edema which was greatest in the piriform cortex. Thus, these studies demonstrate that LiCl pretreatment potentiates cholinomimetic-induced seizures. Further, cholinomimetic-induced seizures produce brain changes resulting in edema.
What does a low-dimensional weather attractor mean?

Abstract Low-dimensional attractors are obtained reliably for a surface thermally-induced atmospheric flow. Different physical processes corresponding with these low dimensions are discussed, and a mathematical mapping of the atmospheric flow patterns from these physical processes is determined.
A transport mechanism in hollow nylon fiber reverse osmosis membranes for the removal of ddt and aldrin from water

Abstract The DuPont hollow nylon fiber reverse osmosis membranes were investigated for use in the removal of DDT and Aldrin from aqueous solution. Because these membranes were developed for the demineralization of brackish waters the removal characteristics for the pesticides were compared with the removal characteristics for the ions commonly found in brackish and hard waters. These membranes rejected 85–95 per cent of the brackish-producing ions. Such inorganic ions with respect to the membrane were classified as membrane-non-interacting solutes. DDT and Aldrin were classified as membrane-interacting solutes, and thus the concept of solute rejection by the membrane was different from that which had been developed for the inorganic ions.
Curriculum redesign: Concurrently addressing content mastery and development of cognitive abilities

Design or redesign of undergraduate engineering curricula is a complex process. Curriculum redesign addresses both development of content mastery as well as development of cognitive abilities that are common across engineering disciplines. Concurrently addressing learning outcomes in both cognitive ability and content mastery presents a substantial challenge for faculty curriculum committees. This paper outlines a process and offers tools to facilitate curriculum redesign for student learning.
Parish nursing and Clinical Pastoral Education.

ABSTRACT Parish nursing is growing within the church. Providing Clinical Pastoral Education (CPE) to parish nurses can be a rich experience for them, their congregations, and persons in leadership positions. In turn, such educational efforts can provide CPE programs with a legitimate and credible community outreach. This contribution describes a CPE Introductory Unit for parish nurses and explores its implications for the nurses, their congregations and the CPE movement.