cssi/SciSciGPT-SciSciNet huggingface dataset:
Starr-Edwards Mitral Valve Failure Ten Years After Replacement Surgery: Chronic Fibrous Obstruction of the Prosthesis Frustrum Area: Report of a Case

A case of malfunction of a Starr-Edwards caged-ball mitral prosthesis occurring ten years after implantation is presented. The possibility of late malfunction must be suspected in any patient who redevelops symptoms after valve replacement. Preservation of normal prosthetic opening and closing clicks does not prove that the device is functioning normally. The diagnosis is difficult, with cardiac catheterization and demonstration of mitral obstruction providing the most valuable information. Once the diagnosis of prosthesis obstruction is made, reoperation and replacement is mandatory. This clinical pattern will be seen with increasing frequency as patients with artificial valves are followed over longer periods of time.
Generation of tumor-targeted human T lymphocytes from induced pluripotent stem cells for cancer therapy

Progress in adoptive T-cell therapy for cancer and infectious diseases is hampered by the lack of readily available, antigen-specific, human T lymphocytes. Pluripotent stem cells could provide an unlimited source of T lymphocytes, but the therapeutic potential of human pluripotent stem cell-derived lymphoid cells generated to date remains uncertain. Here we combine induced pluripotent stem cell (iPSC) and chimeric antigen receptor (CAR) technologies to generate human T cells targeted to CD19, an antigen expressed by malignant B cells, in tissue culture. These iPSC-derived, CAR-expressing T cells display a phenotype resembling that of innate γδ T cells. Similar to CAR-transduced, peripheral blood γδ T cells, the iPSC-derived T cells potently inhibit tumor growth in a xenograft model. This approach of generating therapeutic human T cells 'in the dish' may be useful for cancer immunotherapy and other medical applications.
Shape coexistence and their configuration mixing in 98 Sr and 100 Zr

The configuration mixing between the first two ${0}^{+}$ states in ${}^{98}\mathrm{Sr},$ which have very different deformation, has been reanalyzed by introducing the term involving the intrinsic $E2$ matrix element between them in a two-state-mixing model calculation. A mixing strength of $\ensuremath{\approx}2.6%$ was determined using the known $E0$ strength and the intrinsic $E2$ matrix elements for those two ${0}^{+}$ states. This mixing strength is nearly a factor of 4 weaker than that of the early analysis. Comparison is made to a similar case of configuration mixing in ${}^{100}\mathrm{Zr}.$
Time and money: The universals of macroeconomic theorizing☆

Abstract A broad overview of the macroeconomic literature suggests that two objects of economizing behavior, time and money, are the universals or common denominators of macroeconomic theory. Explicit recognition of these universals allows for a fruitful comparison of Keynesians and Monetarists. The former tend to deny the possibility of a market solution to macroeconomic problems, while the latter tend to deny the problems themselves. Austrian macroeconomics, which consists of an integration of capital theory and monetary theory and lies between these two extreme positions, is used to assess recent developments in the mainstreams of macroeconomics.
Characterization of coal before and after supercritical CO2 exposure via feature relocation using field-emission scanning electron microscopy

Abstract The solvent and swelling effects of supercritical CO2 on coal structure and porosity were examined using high-resolution field-emission scanning electron microscopy (FE-SEM) and surface area techniques to investigate any irreversible CO2 induced alterations of the micro-, meso-, and macropores. Dry, 1 in. unconfined cores of Pittsburgh and Sewickly bituminous coals were exposed to supercritical CO2 at 15.3 MPa (2200 psig) and 328 K (55 °C) for 104 days. Prior to CO2 exposure, coal structure and porosity – specifically macropores (>50 nm) – were imaged using FE-SEM. After CO2 exposure, the imaged features were relocated, reimaged, and analyzed for structural changes. Brunauer–Emmett–Teller (BET) surface areas were evaluated from the adsorption isotherms of N2 at 77 K and P/P0 = 0.1–0.3. Micropore surface areas were determined from the low-pressure adsorption isotherms of CO2 at 293 K using the Dubinin–Polanyi equation. FE-SEM analysis indicated that there were no significant changes observed in the pore areas in all coal samples after CO2 exposure. Meso- and micropore characteristics were slightly affected by supercritical CO2 exposure.
Catalase: Its role in xenobiotic detoxification

Catalase activity is found primarily in peroxisomes although in some species and in some organ systems, cytosolic catalase also may be involved in intracellular oxidant stress protection. Toxicology studies with repeat exposures to xenobiotics producing hydrogen peroxide either directly or indirectly generally indicate that the organisms develop resistance to the toxin (adaptation). This adaptation would result from induction of catalase activity in most target organs. The induction of hepatic peroxisomes accompanied by less than compensatory increase in catalase activity is now recognized as suggesting a potential for hepatotoxic and hepatocarcinogenic effects. Although these effects seem to also require mobilization of fatty acids, it is not clear if such mobilization is an absolute requirement. As would be expected, there are great differences among species in catalase activity thus making animal-human extrapolations difficult. Finally, with the exception of premature and neonatal animals, age-related variations in catalase activity do not seem to be large enough to have toxicological relevance. However, in old animals, their apparent inability to replace lost catalase activity after repeated stress may have major significance in explaining observed young-old differences in toxicity resulting from oxidant stress.
HFE and Transferrin Directly Compete for Transferrin Receptor in Solution and at the Cell Surface

Transferrin receptor (TfR) is a dimeric cell surface protein that binds both the serum iron transport protein transferrin (Fe-Tf) and HFE, the protein mutated in patients with the iron overload disorder hereditary hemochromatosis. HFE and Fe-Tf can bind simultaneously to TfR to form a ternary complex, but HFE binding to TfR lowers the apparent affinity of the Fe-Tf/TfR interaction. This apparent affinity reduction could result from direct competition between HFE and Fe-Tf for their overlapping binding sites on each TfR polypeptide chain, from negative cooperativity, or from a combination of both. To explore the mechanism of the affinity reduction, we constructed a heterodimeric TfR that contains mutations such that one TfR chain binds only HFE and the other binds only Fe-Tf. Binding studies using a heterodimeric form of soluble TfR demonstrate that TfR does not exhibit cooperativity in heterotropic ligand binding, suggesting that some or all of the effects of HFE on iron homeostasis result from competition with Fe-Tf for TfR binding. Experiments using transfected cell lines demonstrate a physiological role for this competition in altering HFE trafficking patterns.
Structural and thermal studies on the V1−2xMx3+NbxO2 and V1−2xMx2+Mx6+O2, systems

Abstract It has long been known that the crystal structure and the transition temperature of VO2 can be altered by introducing simple and charge coupled substituent ions into crystalline solution. Experiments have been continued in the present study to discover the effect of charge coupled substitutions of the type M3+Nb5+O4 (M  Fe or Cr) and M2+M6+O4 (M2+  Ni, Cu or Mn and, M6+  W, Mo or Te). The structural transitions monoclinic-monoclinic-tetragonal or monoclinic-tetragonal have been identified for each composition and their dependence on the amounts of dopants and ionic radii of ions substituted for V4+ determined. The results of the present findings show that the crystalline solutions containing M3++Nb5+ show an initial decrease in the Ttr followed by an increase as M3+NbO4 is added, while in all M6++M2+ substitutions Ttr is always lowered. The substitution of Cr2WO6 and MnWO4 in the binary V1−2xCrxVxO2 crystalline-solution series showed first an increase and then a decrease in the Ttr for these ternarysolid-solutions.
Trends in Land–Atmosphere Interactions from CMIP5 Simulations

AbstractData from 15 models of phase 5 of the Coupled Model Intercomparison Project (CMIP5) for preindustrial, historical, and future climate change experiments are examined for consensus changes in land surface variables, fluxes, and metrics relevant to land–atmosphere interactions. Consensus changes in soil moisture and latent heat fluxes for past-to-present and present-to-future periods are consistent with CMIP3 simulations, showing a general drying trend over land (less soil moisture, less evaporation) over most of the globe, with the notable exception of high northern latitudes during winter. Sensible heat flux and net radiation declined from preindustrial times to current conditions according to the multimodel consensus, mainly due to increasing aerosols, but that trend reverses abruptly in the future projection. No broad trends are found in soil moisture memory except for reductions during boreal winter associated with high-latitude warming and diminution of frozen soils. Land–atmosphere coupling i...
The electron beam‐induced cationic polymerization of epoxy resins

The rapid, efficient electron beam-induced cationic polymerization of epoxy resins containing cyclohexene epoxide (Cye) units (Cye)CH 2 CH 2 Si(Me) 2 OSi(Me) 2 CH 2 CH 2 (Cye), R-Si[OSiCH 2 CH 2 (Cye)] 3 (R = CH 3 , Ph), Si 4 O 4 (CH 3 ) 4 (CH 2 CH 2 Cye) 4 was carried out in the presence of diaryliodonium and triarylsulfonium salts. These polymerizations take place at low doses (1-3 Mrad), which make them attractive for commercial applications. The factors that contribute to the high reactivity of these monomers are discussed.
Coping predicts depression and disability in heart transplant candidates

Abstract Objective The aim of this study was to describe the coping strategies used by cardiac patients who are pursuing heart transplant and to determine which coping strategies are related to depression and self-reported disability. Method This is a cross-sectional design with 50 cardiac patients (74% male) who were inpatients being evaluated for heart transplant at a large medical center. Coping styles were measured using the COPE Inventory (Carver CS, Scheier MF, Weintraub, JK. Assessing coping strategies: a theoretically based approach. J Pers Soc Psychol 1989;56:267–83). Depression was assessed with the Structured Interview Guide for the Hamilton Depression Rating Scale (HAM-SIGH-D; Hamilton M. A rating scale for depression. J Neurol Neurosurg Psychiatry 1960;23:56–62), and disability was assessed using the Sickness Impact Profile (SIP; Bergner M, Bobbitt R, Carter W, Gilson B. The Sickness Impact Profile: development and final revision of a health status measure. Med Care 1981;19:787–805). Results Patients reported using a variety of adaptive coping strategies, but depression and disability were only significantly correlated with maladaptive coping strategies. Multiple regressions demonstrated that denial had the strongest association with depression, and focusing on and venting emotions had the strongest association with disability. Conclusions Maladaptive coping styles, such as denial and focusing and venting of emotions, can serve as markers of emotional distress and disability that may identify patients who may benefit from psychologic and psychiatric interventions.
Method for determining iron-binding capacity of serum.

Summary1. A simple radioisotopic method is described for determining the iron-binding capacity of serum. 2. In principle, iron labelled with a radioactive tracer is added to a serum sample in excess of the binding capacity, and that which becomes attached is separated by protein precipitation and measured isotopically. 3. The method was evaluated by measurement of: (a) the recovery of radioiron added in increments to serum samples, (b) the amount of iron exchanged between the saturated iron proteinate and the excess iron in solution, and (c) the difference in residual binding capacities from the original value after the addition of increments of nonradioactive Fe ascorbate to serum samples.
Consumer innovativeness: Impact on expectations, perceptions, and choice among retail formats

Abstract Individual differences in innovativeness may drive consumer expectations and perceptions regarding retail environments, influencing preferences for particular store formats. This research investigates the impact of consumer innovativeness on expectations for, and perceptions of, service design elements, including employee performance, process design, design of physical evidence, and reliability of the shopping experience. Findings indicate that the majority of consumers expect high performance along all dimensions and dislike surprising stores, specifically those they perceive as risky. Moreover, innovative consumers expect even higher levels of store attributes and in fact perceive stores differently than do less innovative consumers.
Simulated annealing with floating Gaussians: Hellmann-Feynman forces without corrections.

An all-electron density-functional-based molecular-dynamical algorithm for static and dynamic studies of atomic clusters is formulated and discussed. A time-dependent fictitious Lagrangian that depends on both the classical nuclear positions as well as the quantum-mechanical electronic variational parameters is introduced. By integrating the resulting equations of motion, the static ground state of a many-electron and -nuclei system may be found. A floating Gaussian formulation is introduced, and we demonstrate that, by allowing the nonlinear Gaussian parameters and positions to vary so as to minimize the total energy, the Pulay corrections to the Hellmann-Feynman force vanish. Further advantages of this method over conventional diagonalization schemes are that it allows for a compact self-optimizing basis set and that the algorithm is not susceptible to numerical instabilities when nearly, or exact, linear dependencies are encountered. By expanding the electronic wave functions in terms of floating s-type Gaussian orbitals, the method is illustrated with applications to the ${\mathrm{Li}}_{2}$ molecule and the Ne atom. Results are in excellent agreement with other theoretical results and experiments.
Percolation and the Potts model

The Kasteleyn-Fortuin formulation of bond percolation as a lattice statistical model is rederived using an alternate approach. It is shown that the quantities of interest arising in the percolation problem, including the critical exponents, can be obtained from the solution of the Potts model. We also establish the Griffith inequality for critical exponents for the bond percolation problem.
Behavioral alterations due to diesel exhaust exposure

Abstract Several experiments examining the effects of diesel exhaust on the behavior of rats are reported. Animals were exposed either as adults or neonates. The spontaneous locomotor activity (SLA), measured in standard running wheel cages, of adult rats exposed for 8 h/day, 7 days/week was significantly less than that of controls. Experiments involving diesel exhaust exposure to neonatal rats indicated that adult rats, exposed to diesel exhaust during their neonatal lives, were significantly less active as measured by SLA. Adult rats, exposed to 20 h diesel per day as neonates, were placed in skinner boxes after the SLA experiment described above had been completed. The exhaust exposed animals showed significantly decreased acquisition of a food reinforced bar pressing task. All animals that learned this task extinguished at the same rate. The results of the neonatal diesel exhaust experiments support the hypothesis that diesel exhaust exposure during development of an organism can lead to behavioral differences in adulthood.
Holographic video display based on guided-wave acousto-optic devices

We introduce a new holo-video display architecture ("Mark III") developed at the MIT Media Laboratory. The goal of the Mark III project is to reduce the cost and size of a holo-video display, making it into an inexpensive peripheral to a standard desktop PC or game machine which can be driven by standard graphics chips. Our new system is based on lithium niobate guided-wave acousto-optic devices, which give twenty or more times the bandwidth of the tellurium dioxide bulk-wave acousto-optic modulators of our previous displays. The novel display architecture is particularly designed to eliminate the high-speed horizontal scanning mechanism that has traditionally limited the scalability of Scophony- style video displays. We describe the system architecture and the guided-wave device, explain how it is driven by a graphics chip, and present some early results.
Designing efficiencies: The parallel narratives of distance education and composition studies

Abstract Distance education (DE) programs at many universities have been initiated to generate new efficiencies for the academic process, particularly cost efficiency and pedagogical efficiency. In writing studies, this move toward digitally mediated instruction has, in some classrooms, recreated practices that resonate with the pedagogy that resulted from Current-Traditional Rhetoric (CTR). Thus, a trace of distance education's and composition studies’ parallel narratives demonstrates that writing studies has already addressed some of the questions (and concerns) that online writing instruction raises. By specifically focusing on the tensions created by negotiating cost efficiencies and pedagogical efficiencies with communication efficiencies and medium efficiencies, we interrogate current administrative decisions as well their pedagogical outcomes. We conclude by proposing strategies for rearticulating future narratives about online writing instruction in potentially productive ways.
Serial order in writing— A study of misspelled words in “developmental dysgraphia”

Abstract This report is based on the analysis of the systematically erroneous spelling noted in the diary of an adult of “bright normal intelligence”. The vocabulary used in that text is quite rich, hence providing a material rarely available as the spontaneous production of a “poor speller”. 1. (1) A morphological classification of the misspellings is presented: 1.1. I. Addition e.g. “SERVERAL” (several), 1.2. II. Deletion e.g. “ELDERY” (elderly), 1.3. III. Substitution e.g. “MIGNIGHT” (midnight), 1.4. IV. Inversion e.g. “PRESENEC” (presence). Nearly all of the few hundred erroneous words found in the diary, several of which contain more than one misspelling (e.g. “FORIENGRESS” for “foreigners”), can be classified under these headings. Faulty word ordering in a sentence occurs less frequently, but when present assumes similar patterns. 2. (2) It is suggested that the significant factor in the production of such misspellings is a difficulty with the temporo-spatial reproduction of letters in conventional serial order. The phonetic structure of a word can occasionally act as a reinforcing element in the appearance of such sequential errors. 3. (3) A common denominator of all these types of errors is the role played by an actual or virtual pair of identical letters. A comparative study of the structure of the correct and of the misspelled words tends to show the influence of symmetrical components in the genesis of faulty sequences. 4. (4) It is stressed that sequencial errors can appear as the result of an acquired lesion just as they can persist in the presence of a developmental deficit. 5. (5) A diagnosis of developmental dysgraphia is put forward for the case reported. It is, however, suggested that cases such as the one analyzed are primarily disorders of spelling. It is implied that in such cases of developmental dysgraphia and dyslexia, comprehension is only secondarily impaired, namely, if the difficulty with the serial order of symbols become sufficiently severe.
Determinacy in L(ℝ, μ)

Assume V = L(ℝ, μ) ⊨ ZF + DC + Θ > ω2 + μ is a normal fine measure on &#x1d4ab;ω1(ℝ). We analyze what sets of reals are determined and in fact show that L(ℝ, μ) ⊨ AD. This arguably gives the most optimal characterization of AD in L(ℝ, μ). As a consequence of this analysis, we obtain the equiconsistency of the theories: "ZFC + there are ω2 Woodin cardinals" and "ZF + DC + Θ > ω2 + there is a normal fine measure on &#x1d4ab;ω1(ℝ)".
The use of neural networks in determining operational policies for manufacturing systems

Abstract In a dynamic manufacturing environment, an operational policy prescribes when and how tasks are assigned to resources. Recent research has investigated the behavior of operational policies that can be tailored to specific manufacturing situations through the selection and evaluation of pertinent manufacturing decision making (MADEMA) criteria. Often, however, the relationship between the relative importance of these criteria and the overall performance of the manufacturing system is impossible to analytically establish. This paper explores the use of neural networks for identifying the relative importance of these criteria for given performance goals of the manufacturing system.
The stunned atrial lead: Transient malfunction of a permanent atrial pacer lead following acute myocardial infarction

Proximal right coronary artery occlusion caused transient loss of sensing and capture of the atrial lead of a permanent dual-chamber pacemaker. Forty-five days after percutaneous revascularization, the atrial lead was discovered to be functioning normally. We hypothesize that ischemia of the right atrium caused stunning of the atrial myocardium at the pacer-lead interface, which gradually improved following percutaneous coronary intervention (PCI), leading to return of lead function over time. So far only one similar case has been described in the literature.
Microstructural observations of as-prepared and thermal cycled NiCoCrAlY bond coats

Abstract Microstructures of as-prepared and 1100 °C/100 h isothermally annealed NiCoCrAlY bond coat specimens as well as a bond coat obtained from an end of life turbine blade were characterized with TEM. In all specimens the γ grains were observed to consist of fine γ′ precipitates, which form during cooling and are unstable at the higher operating temperatures. The β grains present in the as-prepared specimens were observed to transform to L1 0 martensite in the 1100 °C/100 h isothermally annealed specimen. As a result of substrate-bond coat interdiffusion the M s temperature increases during thermal cycling due to an increase in Ni and decrease in the Cr concentrations of the β-phase. The turbine blade bond coat was also found to contain Cr and Co-rich σ-phase precipitates.
A recombination assay of high molecular weight nerve growth factor protein complexes.

— The 7S Nerve Growth Factor (NGF) found in mouse is a protein composed of three dissimilar subunits designated α, γ, and β. Mouse NGF reversibly dissociates into its component subunits at pH values lower than 5 or greater than 8. The 7S protein complex is in fast equilibrium wiih the free subunits. A quantitative determination of 7S NGF based on the reversible dissociation of the molecule into its subunits is reported here. The basis for this procedure is the addition of [125I]α subunit which competes with the native alpha in the 7S complex. The level of NGF present in a sample can be measured in terms of the displacement of [125I]α from the α to the NGF position in a linear sucrose gradient. Measurements are sensitive to 3.5ng of NGF, linear, and specific for the NGF molecule. This exchange is unaffccted by competing unrelated growth factors and inhibiting enzymes. Its specificity was checked by the standard bioassay and by radioimmunoassay. In addition, the assay technique overrides masking by biological inhibitors and/or by the presence of antibodies directed against the IgG contaminant in murine 75 NGF.
A Narrative Therapy Approach to Counseling: A Model for Working with Adolescents and Adults with Language-Literacy Deficits.

Purpose Remediation efforts with adolescents and adults with language-literacy deficits (LLD) may be hindered by concomitant factors such as decreased self-esteem and self-efficacy. Despite sound l...
Hydrodynamics code calculations of debris clouds produced by ball-plate impacts

Abstract When a metal projectile hits a thin metal plate at a high enough velocity to penetrate it, a cloud of debris is produced, whose structure for normal impacts provides a unique test for hydrodynamic computer simulation. Since the equations of state (EOS) of the materials involved are a vital ingredient for hydrocode calculations, we would like to determine how important it is to use an accurate EOS. This paper reports results of benchmark calculations of hypervelocity impacts of a lead sphere on a lead plate where significant vaporization occurs. The results are somewhat sensitive to the EOS used, particularly in the regime where the material is expanded. The results are greatly affected when an attempt is made to include nonequilibrium effects by allowing negative pressures in the EOS.
Gas-Phase Molecular, Molecular Pair, and Molecular Triplet Fe+ Affinities of Pyridines

The relative molecular, molecular pair, and molecular triplet Fe+ affinities of pyridines are determined by the kinetic method through examination of the competitive dissociation of Fe+-bound dimer...
LOCALIZATION OF LONGITUDINAL WAVES IN BI-PERIODIC ELASTIC STRUCTURES WITH DISORDER

A formulation for studying the effect of random variation in the transfer matrix on the attenuation behavior of disordered one-dimensional bi-periodic layered structures is developed. This formulation, however, can be used for both stochastically and deterministically disordered systems. The mean and variance of localization factors for the disordered systems are numerically evaluated under the assumption that the source of disorder is the variance in the Young's modulus of the first layer of a set, and this variation is modelled by a random variable with uniform probability density function. In the calculations for the mean localization factor and its variance for two layered systems with different elasticity properties are considered for four different levels of disorder. The results presented in the current work is used to explain how the attenuation zones of a perfect system expand into adjacent propagation zones due to disorder. It is found that while the existence of disorder affects the structures of all propagation zones, its significance is most predominant in the first propagation zones of both systems. However, as the frequency increases, the disorder level and the effect of elastic coupling become less significant. Therefore, the wave components corresponding to higher propagation zones penetrate deeper into a structure. It is observed that the right boundary of the propagation zones is the mean localization factor asymptote. The behavior of the mean Lyapunov curves near the right propagation zone boundaries explains how the disorder level governs the expansion of attenuation zones into propagation zones. This expansion is strongest in the first propagation zone. Since the power density of motion induced by an external force is high in the first propagation zone, the structure and size of first propagation zone are of a particular interest in transient analysis. The structures of the variance curves exhibit similar behavior to those for the mean localization factor.
Characterization of 2n-periodic binary sequences with fixed 2-error or 3-error linear complexity

The linear complexity of sequences is an important measure of the cryptographic strength of key streams used in stream ciphers. The instability of linear complexity caused by changing a few symbols of sequences can be measured using k-error linear complexity. In their SETA 2006 paper, Fu et al. (SETA, pp. 88---103, 2006) studied the linear complexity and the 1-error linear complexity of 2 n -periodic binary sequences to characterize such sequences with fixed 1-error linear complexity. In this paper we study the linear complexity and the k-error linear complexity of 2 n -periodic binary sequences in a more general setting using a combination of algebraic, combinatorial, and algorithmic methods. This approach allows us to characterize 2 n -periodic binary sequences with fixed 2- or 3-error linear complexity. Using this characterization we obtain the counting function for the number of 2 n -periodic binary sequences with fixed k-error linear complexity for k = 2 and 3.
Rates of reaction of pyrite and marcasite with ferric iron at pH 2

Abstract The relative reactivities of pulverized samples (100–200 mesh) of 3 marcasite and 7 pyrite specimens from various sources were determined at 25°C and pH 2.0 in ferric chloride solutions with initial ferric iron concentrations of 10−3 molal. The rate of the reaction: FeS 2 + 14 Fe 3+ + 8 H 2 O = 15 Fe 2+ + 2 SO 2− 4 + 16 H + was determined by calculating the rate of reduction of aqueous ferric ion from measured oxidation-reduction potentials. The reaction follows the rate law: −dm Fe 3+ dt = k( A M )m Fe 3+ where mFe3+ is the molal concentration of uncomplexed ferric iron, k is the rate constant and A M is the surface area of reacting solid to mass of solution ratio. The measured rate constants, k, range from 1.0 × 10−4 to 2.7 × 10−4 sec−1 ± 5%, with lower-temperature/early diagenetic pyrite having the smallest rate constants, marcasite intermediate, and pyrite of higher-temperature hydrothermal and metamorphic origin having the greatest rate constants. Geologically, these small relative differences between the rate constants are not significant, so the fundamental reactivities of marcasite and pyrite are not appreciably different. The activation energy of the reaction for a hydrothermal pyrite in the temperature interval of 25 to 50°C is 92 kJ mol−1. This relatively high activation energy indicates that a surface reaction controls the rate over this temperature range. The BET-measured specific surface area for lower-temperature/early diagenetic pyrite is an order of magnitude greater than that for pyrite of higher-temperature origin. Consequently, since the lower-temperature types have a much greater A M ratio, they appear to be more reactive per unit mass than the higher temperature types.
Cosmetics in the Treatment of Acne Vulgaris

This article describes scenarios of patients who have acne vulgaris have tried over-the-counter products and cosmetics and are disheartened by the persistence of their disease and the resulting scars. They may have seen an aesthetician, plastic surgeon, or even a general practitioner before seeing a well-informed skin specialist. Patients perceive the dermatologist to be the skin care expert and seek guidance to obtain otherwise unobtainable results. Therefore, practicing dermatologists should take advantage of the available tools to treat patients aggressively and completely. Appropriately applied cosmetics can play a role in achieving this goal. This article describes scenarios that integrate cosmetics into an anti-acne treatment regimen that is effective and safe for all ethnic groups and is well tolerated by both male and female patients.
Performance Assessment of Probe for Radio-Frequency Ablation

Radio-frequency (RF) ablation is one of the most widely used methods for the treatment of hepatic malignancies. A finite element method (FEM) analysis was employed to determine the thermal dose delivered to the tumor/tissue region. We simulated heating within a RF probe implanted in generic tumor surrounded by healthy tissue using ANSYS. The 3-D model consists of a tumor / tissue region into which the RF probe is embedded inside the tumor. One-quarter symmetry was then invoked. The blood flow was modeled using Penne’s bio-heat transfer equation with differing perfusion rates between the healthy tissue and tumor volume based on literature values. The resulting temperature distribution throughout the region was determined over time. A program was written in Visual Basic to extract the temperature distribution data in the tumor/tissue region and calculate the thermal dose throughout the region. This was done by using a time–temperature Arrhenius relationship for chemical and physical rate process. Tissue necrosis is assumed complete when a thermal dose of one hour has been achieved at 43 °C. In the present study, the geometry of the electrode had a significant effect on the size of the volume of necrosis. It was found that the lower portion of the tumor did not receive the specified thermal dose relative to the upper portion of the tumor in single setting during the RF ablation therapy. This might be due to the Ni-Ti electrode, which protruded only from the top surface of the trocar. The effectiveness of the existing probe can be improved by having one more set of electrodes protruding out from the lower curved surface of the trocar. It was found that the modified probe significantly improved heating in the lower portion of tumor/tissue area, providing more symmetry between the upper and lower portion.Copyright © 2004 by ASME
Oxygen and hydrogen isotope compositions of Permian pedogenic phyllosilicates: Development of modern surface domain arrays and implications for paleotemperature reconstructions

Abstract Mineralogic, chemical, and oxygen and hydrogen isotope compositions of 15 different phyllosilicate samples from Permo–Pennsylvanian-age paleosols of the eastern shelf of the Midland basin of Texas and the southern Anadarko basin are presented. Mixtures of 2 : 1 phyllosilicates and kaolinite dominate most samples, although some samples consist of relatively pure 2 : 1 phyllosilicates. Chemical and mineralogic data are used in conjunction with published thermodynamic data to calculate hydrogen and oxygen isotope fractionation factors for each sample. In turn, application of measured oxygen and hydrogen isotope compositions of the phyllosilicates to temperature-dependent fractionation equations are used to calculate paleotemperatures of crystallization. The δD values of the phyllosilicates range from − 69‰ to − 55‰. The δ18O values range from 19.5‰ to 22.7‰. If these samples preserve a record of equilibrium with paleo-meteoric waters, the isotopic compositions of the phyllosilicates correspond to paleotemperatures of phyllosilicate crystallization ranging from 22 ± 3 °C to 35 ± 3 °C. In particular, the stratigraphic trend of calculated temperatures from Midland basin samples suggests that Early Permian surface temperatures may have been up to 10 °C warmer than those of the latest Pennsylvanian.
Phases of Ba adsorption on Si(100)-(2×1) studied by LEED and AES

Abstract Phase transitions of Ba adsorption on a clean Si(001)-(2×1) studied by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) are reported. The depositions of the Ba were performed with (a) the substrate held at room temperature followed by annealing at elevated temperatures, and (b) the substrate held at 900°C. While confirming earlier established phases, the existence of 4× streaks in the (3×2)+c(6×2) and (2×1) phases has been identified. Also found was a real-time phase transition from a (3×2) phase to a mixture of (3×2) and c(6×2) phases during sample cooling. Finally, it was found that AES of Ba/Si peak ratios exhibit plateaus in the phase vs. temperature diagram for the (3×2), (3×2)+c(6×2), and (2×1)+4× streak phases, indicating a temperature-dependent mechanism limiting the Ba coverage.
Interaction and reactivity of nitric oxide and carbon monoxide on ruthenium surfaces

A multifaceted investigation of the reduction of nitric oxide by carbon monoxide using a ruthenium (102) single crystal catalyst in the pressure range 10/sup -3/ to 10 Torr and temperature range of 300 to 475/sup 0/C has been undertaken. Kinetic and isotopic results indicate that the reaction products CO/sub 2/ and N/sub 2/ were produced via two reaction mechanisms. Using a reducing gas mixture (low P/sub NO//P/sub CO/ ratio) a two site mechanism was operative involving NO dissociation. The carbon monoxide kinetic order varied from +1 to -3 and the nitric oxide order varied from +1 to 0. The catalyst under these conditions was determined to be metallic ruthenium with oxygen bonded within the first surface layer. The oxygen was unreactive and formed a (1 x 3)-0 LEED pattern. Under oxidizing conditions (high P/sub NO//P/sub CO/ ratio) the catalyst was ruthenium dioxide and the functional mechanism under these reaction conditions yielded a nitric oxide order of +2 to -4. Inclusion of a site poisoning mechanism under reducing conditions and an RuO/sub 2/ growth mechanism involving ruthenium cation transfer under oxidizing conditions into the kinetic rate laws led to an overall rate law which could be fit to the carbon monoxidemore » and nitric oxide order plots. Using isotopically oxygen labelled reactants, it was observed that the three possible isotopes of carbon dioxide were produced. A ..gamma..-CO surface species is postulated as an intermediate in the exchange process. The reaction was observed to be initially surface structure insensitive and the reaction kinetics were derived using a Langmuir-Hinshelwood formalism.« less
Maturation of an Escherichia coli Ribosomal Peptide Antibiotic by ATP-Consuming N−P Bond Formation in Microcin C7

Synthetic phosphoramidate analogues of nucleosides have been used as enzyme inhibitors for decades and have therapeutic applications in the treatments of HIV and cancer, but little is known about how N-P bonds are fashioned in nature. The heptapeptide MccA undergoes post-translational processing in producer strains of Escherichia coli to afford microcin C7 (MccC7), a "Trojan horse" antibiotic that contains a phosphoramidate linkage to adenosine monophosphate at its C-terminus. We show that the enzyme MccB, encoded by the MccC7 gene cluster, is responsible for formation of the N-P bond in MccC7. This modification requires the consumption of two ATP molecules per MccA peptide and formation and breakdown of a peptidyl-succinimide intermediate.
A low-height 15-ton mine locomotive for low vein haulage

Mechanization has opened up new possibilities to the coal mining industry. One of these is the mining of coal seams formerly considered too narrow for practical working. Such operations impose severe restrictions on much of the equipment employed. To meet these requirements, a low-height haulage locomotive was designed with the objective of keeping vertical dimensions to a minimum. The fact that a number of these units are now operating successfully on various properties attests the basic soundness of the design.
Differentiated Thyroid Cancer

Differentiated thyroid cancer, which includes papillary and follicular histologies, is a common malignancy and is increasing in incidence. It carries a favorable prognosis compared to other cancers. However, optimal outcomes are achieved only via coordinated multimodal therapy. Of these treatments, surgery is the cornerstone of initial management. Most patients should undergo thyroidectomy with concomitant central neck (level VI) lymph node dissection. On the other hand, thyroidectomy alone may be appropriate for patients with smaller tumors (T1 or T2) and no evidence of suspicious lymphadenopathy. Surgery is also indicated in cases of cervical lymph node metastases and locoregional recurrence. The principal adjuvant therapy is radioactive iodine, which should be considered in patients with a high risk of locoregional recurrence or with metastatic disease. Similarly, suppression of endogenous thyroid-stimulating hormone is recommended in patients with an elevated risk of recurrence. External-beam radiotherapy is indicated in patients with gross extrathyroidal extension or residual disease not amenable to surgery. Finally, molecular therapies, especially those targeting key tyrosine kinases and/or inhibiting angiogenesis, are emerging treatment modalities that could replace the limited efficacy of conventional chemotherapy.
Impaired cognitive function and mental performance in mild dehydration

Dehydration is a reliable predictor of impaired cognitive status. Objective data, using tests of cortical function, support the deterioration of mental performance in mildly dehydrated younger adults. Dehydration frequently results in delirium as a manifestation of cognitive dysfunction. Although, the occurrence of delirium suggests transient acute global cerebral dysfunction, cognitive impairment may not be completely reversible. Animal studies have identified neuronal mitochondrial damage and glutamate hypertransmission in dehydrated rats. Additional studies have identified an increase in cerebral nicotinamide adenine dinucleotide phosphate-diaphorase activity (nitric oxide synthase, NOS) with dehydration. Available evidence also implicates NOS as a neurotransmitter in long-term potentiation, rendering this a critical enzyme in facilitating learning and memory. With ageing, a reduction of NOS activity has been identified in the cortex and striatum of rats. The reduction of NOs synthase activity that occurs with ageing may blunt the rise that occurs with dehydration, and possibly interfere with memory processing and cognitive function. Dehydration has been shown to be a reliable predictor of increasing frailty, deteriorating mental performance and poor quality of life. Intervention models directed toward improving outcomes in dehydration must incorporate strategies to enhance prompt recognition of cognitive dysfunction.
Magnetosphere‐ionosphere coupling during plasmoid evolution: First results

The influence of magnetosphere-ionosphere coupling on the dynamic evolution of the magnetotail is investigated by a three-dimensional resistive MHD code that includes the effects of the closure of field-aligned currents in a simple resistive model ionosphere. Particular emphasis is on the role of this coupling during substorm evolution and the modification of the latter by the convection driven by the ionospheric electric fields. For comparison, results are presented from a simulation which uses an infinitely conducting ionosphere but is otherwise identical. Comparison of the two simulations shows that the major impact of magnetosphere-ionospheric communication is an acceleration of magnetotail evolution. Otherwise, phenomena in the two models are qualitatively similar. It is concluded that ionospheric effects do not significantly affect substorm associated magnetotail dynamics.
Promoting Student Active Classroom Participation Skills Through Instruction to Promote Self-Regulated Learning and Self-Determination:

Promoting self-determination has been identified as a means to both promote access to the general education curriculum and focus on transition-related skills. In particular, the Self-Determined Learning Model of Instruction (SDLMI) has been found to be effective in producing successful transition and academic outcomes for students with cognitive disabilities. The SDLMI enables teachers to teach students a self-directed problem-solving process that enables students to self-regulate learning. This study investigates the effects of the SDLMI on a variety of academic skills for three junior high students with extensive support needs included in a general education health class. Positive changes were reported for all students. The implications of these findings are discussed.
Parameter Estimator Design with Application to a Chemical Reactor

A new method of on-line parameter estimation for a class of nonlinear systems is presented in this paper. The parameter estimator includes a left inverse of process model and at each time instant calculates least-squared-error estimates of parameters by using readily available on-line measurements. The estimator is computationally efficient and easy to implement. The application and performance of the parameter estimation method are illustrated and compared with those of parameter estimation via state estimation, by using a jacketed chemical reactor example for which the reaction-heat rate and overall heat-transfer coefficient are estimated. The simulation results show that the inversion-based estimator outperforms the state-estimation-based parameter estimator in the presence of measurement noise and plant−model mismatch.
DNA helicases in inherited human disorders

Abstract Six known or predicted helicases that are mutated in human syndromes are now recognized. These syndromes include xeroderma pigmentosum, Cockayne's syndrome, trichothiodystrophy, Bloom's syndrome, Werner's syndrome, and α-thalassemia mental retardation on the X chromosome. The clinical abnormalities in these syndromes cover a broad spectrum, pointing to different cellular processes of DNA manipulation that are defective in these syndromes.
Toxicity of ammonia to early life stages of the green sunfish Lepomis cyanellus

Toxicity of ammonia to early life stages of green sunfish Lepomis cyanellus was studied. One chronic and four acute exposure studies were conducted. During the chronic study green sunfish were exposed to a series of ammonia concentrations from the blastula stage through 40 days post-hatching. During the acute studies, juvenile green sunfish were exposed at four pH levels, 6·6, 7·2, 7·7 and 8·7, to derive 3-, 6-, 12-, 24-, 48-, 72- and 96-h LC50 and EC50 concentrations of un-ionised (NH3) and total ammonia (NH3N). Pre-hatching embryological stages were found to be the most resistant stages studied. Hatching success was unaffected when incubation was at ammonia concentrations ranging from undetectable through 0·91 mg litre−1 NH3, the highest concentration tested. Growth was inhibited at 0·49 mg litre−1 NH3 but not at 0·22 mg litre−1 NH3. All larvae died within 10 days of hatching at 1·02 mg litre−1 NH3. The 96-h LC50 concentrations at pH values of 6·6, 7·2, 7·7 and 8·7 were 0·50, 1·06, 1·34 and 1·73 mg litre−1 NH3, or 272, 139, 57 and 9 mg litre−1 NH3N, respectively.
We know who you followed last summer: inferring social link creation times in twitter

Understanding a network's temporal evolution appears to require multiple observations of the graph over time. These often expensive repeated crawls are only able to answer questions about what happened from observation to observation, and not what happened before or between network snapshots. Contrary to this picture, we propose a method for Twitter's social network that takes a single static snapshot of network edges and user account creation times to accurately infer when these edges were formed. This method can be exact in theory, and we demonstrate empirically for a large subset of Twitter relationships that it is accurate to within a few hours in practice.We study users who have a very large number of edges or who are recommended by Twitter. We examine the graph formed by these nearly 1,800 Twitter celebrities and their 862 million edges in detail, showing that a single static snapshot can give novel insights about Twitter's evolution. We conclude from this analysis that real-world events and changes to Twitter's interface for recommending users strongly influence network growth.
ENTRY INTO MARRIAGE AND PARENTHOOD BY YOUNG MEN AND WOMEN: THE INFLUENCE OF FAMILY BACKGROUND

We investigate the influence of family background on early entry into marriage and parenthood among white, Hispanic, and black men and women ages 14 to 22 in the first (1979) wave of the National Longitudinal Survey of Youth. Family background is highly associated with early entry into marriage for whites of both genders and female Hispanics and also with early entry into parenthood for all groups except black males. Large group differences in family characteristics explain most of the difference between white and Hispanic women in early marriage and parenthood and about half the difference in early parenthood between black and white women but do not explain the observed variations among other race-gender groups.