cssi/SciSciGPT-SciSciNet huggingface dataset:
Use of the Image Dissector in Photocathode Research

Publisher Summary This chapter describes the usefulness of the image dissector as a tool for photocathode research. The image dissector is a deflectable multiplier phototube with a small defining aperture. The basic elements of the type used, the Vidissector. The Vidissertor contains an electron source, a region of accelerating field, a drift tube section, an image forming electron lens, a means for deflexion, an aperture, and a signal amplifier. It is evident that the image dissector can be a very versatile tool in the experimental study of photoemissive processes. The tube described in this chapter has both focus and deflexion capabilities and contains an electron multiplier, it was possible to carry out experiments examining the statistics of electron secondary emission as a function of the properties of the source or sources of these electrons. The chapter includes descriptions of progress in examining photoemissive materials, and gives results of pulse-height analysis data, structural studies of photoemissive materials, and data obtained by exploring substrate effects on the emission characteristics of photocathodes.
Specification errors and the Chow test

Abstract Predictive forms of the Chow test are used in investigating structural change when the number of predictors exceeds the number of observations. This test has been argued to be more powerful than the more widely used analysis of covariance test even when the number of predictors does not exceed the number of observations. In that circumstance we show that either the hypothesis claimed is not testable or the test is not uniformly most powerful excepting a fortuitous coincidence between the number of predictors and the number of observations. We suggest an alternative test for structural change conditional on a prior specification test adapted from McAleer and Tse (1988).
Murder by proxy.

Although thyrocytes in two autoimmune diseases of the thyroid both express Fas and FasL, the conditions produce opposite results: either hyper- or hypothyroidism. This may be due to cytokine production indirectly supporting pro- or anti-apoptotic gene expression in thyrocytes.
Modelling “shallow loss” crop revenue programs: Issues and implications for the 2013 Farm Bill

Purpose – The purpose of this paper is to investigate changes proposed in 2012 to commodity programs for the new Farm Bill. Both the Senate and House Agriculture Committee versions of the new Farm Bill eliminate current commodity programs including direct payments, create new revenue‐based commodity program options designed to cover “shallow” revenue losses, and also introduce supplemental crop insurance coverage for shallow revenue losses.Design/methodology/approach – This paper documents the payment functions for the new revenue programs proposed in both the Senate and House Ag Committee Farm Bills, and also estimates expected payments for each using a model based on historical county yield data, farmer‐level risk rates from RMA, and commodity price levels from the March 2012 CBO baseline projections.Findings – The authors find significant variation in expected per acre payment across programs, crops, and regions. In general, the Senate's bill would be expected to be preferred over the House's bill for ...
A metabolic enzyme that rapidly produces superoxide, fumarate reductase of Escherichia coli.

Aerobic organisms synthesize superoxide dismutases in order to escape injury from endogenous superoxide. An earlier study of Escherichia coli indicated that intracellular superoxide is formed primarily by autoxidation of components of the respiratory chain. In order to identify those components, inverted respiratory vesicles were incubated with five respiratory substrates. In most cases, essentially all of the superoxide was formed through autoxidation of fumarate reductase, despite the paucity of this anaerobic terminal oxidase in the aerobic cells from which the vesicles were prepared. In contrast, most dehydrogenases, the respiratory quinones, and the cytochrome oxidases did not produce any detectable superoxide. The propensity of fumarate reductase to generate superoxide could conceivably deluge cells with superoxide when anaerobic cells, which contain abundant fumarate reductase, enter an aerobic habitat. In fact, deletion or overexpression of the frd structural genes improved and retarded, respectively, the outgrowth of superoxide dismutase-attenuated cells when they were abruptly aerated, suggesting that fumarate reductase is a major source of superoxide in vivo. Steric inhibitors that bind adjacent to the flavin completely blocked superoxide production, indicating that the flavin, rather than an iron-sulfur cluster, is the direct electron donor to oxygen. Since the turnover numbers for superoxide formation by other flavoenzymes are orders of magnitude lower than that of fumarate reductase (1600 min−), additional steric or electronic factors must accelerate its autoxidation.
STUDIES IN STEROID METABOLISM. XIX. THE RELATION OF GAS-CHROMATOGRAPHIC RETENTION TIME TO THE STRUCTURE OF STEROIDS AND DERIVATIVES.

Abstract Gas-chromatographic retention data for a series of twenty-five C 19 steriods, incorporating twelve C 5 isomeric pairs, were obtained on four columns of varying polarity and selectivity. Three derivatives of the hydroxyl-containing steriods were also chromatographed on these stationary phases. The relation of structure and conformation to retention time and the anomalous behavior of the C 17 -oxygenated isomers has been described. The relative polarity of two polyesters and two silicone elastomers has been determined. Group factors calculated for the frees steriods and the derivatives suggested the use of the acetates as the derivatives of choice for structural studies, while in terms of separation trimethylsilyl ethers were found to be superior.
Gastric Tone Measured by an Electronic Barostat in Health arid Postsurgical Gastroparesis

Using a gastric barostat we have studied interdigestive variations in gastric tone and its response to gastric distention in 17 healthy volunteers and 5 patients with postsurgical gastroparesis: The barostat measures tone by monitoring the volume of air within a flaccid intragastric bag, maintained at a constant, preselected pressure, level by an electronic feedback mechanism. In healthy individuals, interd gestive variations in gastric tone were phaselocked iii advance of duodenal interdigestive motor activity and consisted of three sequential periods: a quiescence period, an intermediate period, and a period of activity. In contrast to controls, gastroparetic patients presented significantly larger intragastric volume at low intragastric pressure (6 mmHg). Gastric distention (14 mmHg) resulted in significantly reduced extension ratio and phasic motor response in the gastric remnant. Furthermore, distention elicited a symptomatic response that resembled their postcibal syndrome (epigastric fullness, pain, nausea). These data suggest that postsurgical gastroparesis is associated with impaired tone of the residual gastric pouch.
Cultivation of Rhinosporidium seeberi in vitro: interaction with epithelial cells

Rhinosporidium seeberi, a fungus that is associated with polyp-like tumors in animals and man, was successfully cultivated. This organism stimulated proliferation of epithelial cells in vitro, producing polyp-like structures. Spores produced in culture required a period of aging or development, or both, before they were capable of reinitiating the growth cycle.
Neural network constitutive model for rate-dependent materials

Neural network (NN) constitutive model adjusts itself to describe given stress and strain relationship. It is capable of capturing complex material behavior, using stress and strain sets from experiments. This paper presents a rate-dependent NN constitutive model formulation and its implementation in finite element analysis. The proposed NN model is verified for a standard solid viscoelasticity model. The model is then applied to analysis of time-dependent behavior of concrete. The proposed model has potential of capturing any rate-dependent material models, provided enough data sets are given. The issue of what constitutes a sufficient data set to train a neural network constitutive model must be addressed in future research.
Differential inhibition and stimulus generalization cannot account for value transfer in simultaneous discrimination learning by pigeons: Reply to Aitken

Aitken (1999) argues that, in a simultaneous discrimination, reports of the transfer of value from the positive to the negative stimulus can be more readily explained in terms of an artifact produced by the procedure in which differential inhibition accrues to the negative test stimuli during training, together with stimulus generalization (similarity between the positive and negative stimuli). We argue that (1) there is little evidence for differential inhibition, and it often occurs in the wrong direction; (2) value transfer can be demonstrated when differential value is established to the positive stimuli afterdiscrimination training, when differential inhibition is not likely to be a factor; and (3) on both logical and empirical grounds, stimulus similarity does not provide an adequate account of the transfer of value from the positive to the negative stimulus (i.e., the strongest evidence for value transfer occurs when there is least stimulus similarity). We propose that value transfer occurs whenever there is relatively little experience with the negative stimuli. However, when there is extended experience with the negative stimuli, contrast will be found.
PASSENGER TRAVEL TIME AND PATH CHOICE IMPLICATIONS OF REAL-TIME TRANSIT INFORMATION

Abstract This paper considers information systems in public transit in which the passenger receives information in real time regarding projected vehicle travel times. Such information systems may have value to passengers in situations where they may choose among different origin-to-destination paths. To provide a preliminary assessment of these systems, an analytic framework is presented to evaluate path choices and travel time benefits resulting from real-time information. A behavioral model of transit path choice is presented that frames the choice in terms of a decision whether to board a departing vehicle. Furthermore, this path choice model accommodates network travel times that are both stochastic and time-dependent, two elements that have been neglected in previous studies but are critical to evaluating real-time information systems. The path choice model is extended to demonstrate how real-time information may be incorporated by the passenger in making a path choice decision. This analytic framework is applied to a case study corridor at the Massachusetts Bay Transportation Authority (MBTA), using a computer simulation to model vehicle movements and passenger path choices in the corridor. The results suggest that real-time information yields only very modest improvements in passenger service measures such as the origin-to-destination travel times and the variability of trip times. Based on this analysis, the quantitative benefits of real-time information for transit passenger path choices appear to be questionable.
Energetics and electronic structure of stacking faults in ZnO

The energetics and electronic structures of basal-plane stacking faults in wurtzite (WZ) ZnO are studied using first-principles density-functional total energy calculations. All the basal-plane stacking faults are found to have very low formations energies. They also introduce a downward shift at the conduction-band minimum (CBM). However, plane-averaged charge densities of the CBM state reveal that the CBM states are not very localized, indicating that these stacking faults should be electronically inert. The high concentration of these stacking faults can result in embedded zinc-blende (ZB) ZnO surrounded by WZ materials. The WZ/ZB interface exhibits a type-II lineup with $\ensuremath{\Delta}{E}_{V}\ensuremath{\approx}0.037\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ and $\ensuremath{\Delta}{E}_{C}\ensuremath{\approx}0.147\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$.
Failure to take antiepileptic drugs as prescribed: a socioeconomic issue after all.

Context: Because of epilepsy's common occurrence, the narrow therapeutic and safety margins of antiepileptic medications, and the recognized complications of medication nonadherence in adults with epilepsy, identifying the rates, patterns, and predictors of nonadherence in children with epilepsy is imperative. The onset and evolution of antiepileptic drug nonadherence in children with newly diagnosed epilepsy remains unknown. Objectives: To identify and characterize trajectories of adherence in children with newly diagnosed epilepsy over the first 6 months of therapy and to determine sociodemographic and epilepsy-specific predictors of adherence trajectories. Design, Setting, and Patients: Prospective, longitudinal observational study of antiepileptic drug adherence in a consecutive cohort of 124 children (2-12 years old) with newly diagnosed epilepsy at Cincinnati Children's Hospital Medical Center. Patients were recruited from April 2006 through March 2009, and final data collection occurred in September 2009. Main Outcome Measure: Objective adherence measured using electronic monitors. Results: Fifty-eight percent of children with newly diagnosed epilepsy demonstrated persistent nonadherence during the first 6 months of therapy. Group-based trajectory models identified 5 differential adherence patterns (Bayesian information criterion = −23611.8): severe early nonadherence (13%; 95% confidence interval [CI], 8%-20%), severe delayed nonadherence (7%; 95% CI, 3%-12%), moderate nonadherence (13%; 95% CI, 8%-20%), mild nonadherence (26%; 95% CI, 19%-34%), and near-perfect adherence (42%; 95% CI, 33%-50%). The adherence pattern of most patients was established by the first month of therapy. Socioeconomic status was the sole predictor of adherence trajectory group status (χ 2 4 = 19.3 [n = 115]; P 2 = 0.25), with lower socioeconomic status associated with higher nonadherence. Conclusion: Five trajectory patterns were identified that captured the spectrum of nonadherence to antiepileptic drugs among children with newly diagnosed epilepsy; the patterns were significantly associated with socioeconomic status.
Perceptions of insurance coverage for screening mammography among women in need of screening

Breast carcinoma remains the second leading cause of cancer death among women in the U.S. The American Cancer Society estimated that 40,580 women died and another 215,990 women were diagnosed with breast carcinoma in 2004 alone.1 Screening mammography is viewed as an important means of detecting breast carcinoma early,2 and mammography utilization has increased over the past decade. Yet in 2002, nearly 25% of women age ≥ 40 years had not received a mammogram within the past 2 years,3 and nearly 40% of low-income women had never had a mammogram.4 As efforts are made to further increase screening, it becomes more important to understand the various barriers to receiving mammograms. Insurance and cost barriers are noticeably salient among concerns reported by women who do not receive mammograms. Studies repeatedly show that health insurance status and type are significantly predictive of mammography use,5–11 although these effects vary.12,13 Cost has also been shown to be a barrier to mammography screening, and has been widely studied.14–22 However, to our knowledge little attention has been paid to considering the barrier of cost in the context of actual cost and coverage information.23 The actual cost of a mammogram varies considerably with insurance coverage. Women with private insurance or Medicaid are typically fully covered for the cost of a screening mammogram. Women insured by Medicare receive 80% coverage, leaving women responsible to pay approximately $30 out-of-pocket, depending on where they live. Women dually insured by Medicare and Medicaid or Medicare and private insurance typically do not have to pay anything. Uninsured women are responsible for the full cost or must take advantage of reduced cost programs such as the Breast and Cervical Cancer Control Program. Data from a population of low-income and minority women who were patients of a rural health clinic in North Carolina and who had not received a mammogram in at least the past year were used to explore the issues of coverage and cost as possible reasons for nonadherence to mammography guidelines. These data included a number of questions regarding cost and insurance coverage in relation to mammography use. The results reported here have important implications for providers and policymakers attempting to promote the use of screening mammograms among women age > 40 years who are in need of a mammogram.
States variations in the provision of bariatric surgery under affordable care act exchanges

The Affordable Care Act (ACA) attempts to reduce healthcare costs while simultaneously providing the means for more Americans to obtain health insurance. Among other things, the ACA expands preventative care for obesity by mandating screening and counseling. However, it permits the states to determine whether to mandate treatments for inclusion in plans offered on the state-run exchanges. Bariatric surgery is a highly cost-effective treatment for obesity, yet states have taken varying stances on whether to mandate its inclusion. In light of the rising cost of obesity and resulting burden placed on the federal government and the economy, this article advocates a comparable mandatory inclusion of bariatric surgery in all plans offered on state and federally run exchanges.
The relationship between the crystallographic order and electronic structure of mercury thin films

Abstract Thin (1–7 monolayer) well ordered, disordered, and liquid Hg overlayers on Ag (100) have been investigated with angle resolved photoemission and low energy electron diffraction. The well ordered overlayers exhibit new electronic states as a result of the strained, cubic, overlayer crystallographic structure. The photoemission cross section of the electronic states depends on the overlayer long range crystallographic order and cannot be explained by photoelectron diffraction. The new electronic states depend upon the long range crystallographic order of the overlayer not simply the local crystallographic symmetry, a heretofore unreported result.
Early down-regulation of K+ channel genes and currents in the postinfarction heart.

Down-Regulation oi K+ Channel Genes and Currents. Introduction: Down-regulaticn of key K+ channel subunit gene expression and K+ currents is a universal response to cardiac hypertrophy, whatever the cause, including the postmyocdardial infarction (post-Ml) remodeled heart. Methods and Results: We investigated the hypothesis that down-regulation of K+ channel genes and currents post-MI occurs early and before significant remodeled hypertrophy of the noninfarcted myocardium could be detected. We investigated (1) the incidence of induced ventricular tachyar-rhythmias (VT) in 3-day post-MI rat heart; (2) action potential (AP) characteristics of isolated left ventricular (LV) myocytes from sham-operated and 3-day post-MI heart; (3) time course of changes in outward K+ currents Ito-fast(f) Ikin isolated myocytes from 3-day and 4-week post-MI noninfarcted LV and compared the changes with sham-operated animals; and (4) changes in the messenger and protein levels of Kv2.1, Kv4.2. and Kv4.3 in the LV and right ventricle of 3-day post-MI heart. Sustained VT was induced in 6 of 10 3-day post-MI rats and in none of 8 sham rats. The membrane capacitance of myocytes isolated from 3-day post-MI noninfarcted LV was not significantly different from control, whereas membrane capacitance 4-week post-MI was significantly higher, reflecting the development of hypertrophy. AP duration was increased and the density of Ito-f and Ik were significantly decreased in 3-day post-MI LV myocytes compared with sham. The reduced density of Ito, did not significantly differ in 4-week post-MI LV myocytes, whereas the density of Ik was decreased further at 4 weeks post-MI. The changes in Ito-f and Ik correlated with decreased messenger and protein levels of Kv4.2/Kv4.3 and Kv2.l, respectively. Conclusion: These results support the hypothesis that down-regulation of K+ channel gene expression and current in the post-MI LV occurs early and may be dissociated from the slower time course of post-MI remodeled hypertrophy. These changes may contribute to early arrhythmogenesis of the post-MI heart.
Cytogenetic findings in the dysmyelopoietic syndrome

Cytogenetic studies of bone marrow specimens from 15 patients with dysmyelopoietic syndrome are presented. The group consists of nine patients with refractory anemia with excess of blasts (RAEB), three patients with chronic myelomonocytic leukemia (CMMoL), and three patients with acquired idiopathic sideroblastic anemia (AISA). None of these patients had a prior history of therapeutic or occupational exposure to potential carcinogenic agents, G(TG)-banding revealed clonal abnormalities in nine of the 15 patients. Five of these patients exhibited one or more of the following cytogenetic abnormalities: 5q deletion, -7, +8, or +21. The AISA group appeared to be unique as chromosome abnormalities were seen in two of the three patients and the clinical course in these patients had been prolonged without progression to acute leukemia. No other clinical correlation could be made in the blast RAEB and CMMoL groups, except for possible survival benefit in patients with normal karyotypes.
One frame and several new infinite families of Z-cyclic whist designs

Abstract In 2001, Ge and Zhu published a frame construction which they utilized to construct a large class of Z -cyclic triplewhist designs. In this study the power and elegance of their methodology is illustrated in a rather dramatic fashion. Primarily due to the discovery of a single new frame it is possible to combine their techniques with the product theorems of Anderson, Finizio and Leonard along with a few new specific designs to obtain several new infinite classes of Z -cyclic whist designs. A sampling of the new results contained herein is as follows: (1) Z -cyclic Wh(3 3 p +1), p a prime of the form 4 t +1; (2) Z -cyclic Wh(3 2 n +1 s +1), for all n ⩾1, s =5,13,17; (3) Z -cyclic Wh(3 2 n s +1), for all n ⩾1, s =35,55,91; (4) Z -cyclic Wh(3 2 n +1 s ), for all n ⩾1, and for all s for which there exist a Z -cyclic Wh(3 s ) and a homogeneous ( s ,4,1)-DM; and (5) Z -cyclic Wh(3 2 n s ) for all n ⩾1, s =5,13. Many other results are also obtained. In particular, there exist Z -cyclic Wh(3 3 v +1) where v is any number for which Ge and Zhu obtained Z -cyclic TWh(3 v +1).
Vocal fold nodules in adult singers: Regional opinions about etiologic factors, career impact, and treatment. A survey of otolaryngologists, speech pathologists, and teachers of singing

Summary This study was undertaken to better understand current regional opinions regarding vocal fold nodules in adult singers. A questionnaire was sent to 298 persons representing the 3 professional groups most involved with the care of singers with vocal nodules: otolaryngologists, speech pathologists, and teachers of singing. The questionnaire queried respondents about their level of experience with this problem, and their beliefs about causative factors, career impact, and optimum treatment. Responses within and between groups were similar, with differences between groups primarily in the magnitude of positive or negative responses, rather than in the polarity of the responses. Prevailing opinions included: recognition of causative factors in both singing and speaking voice practices, optimism about responsiveness to appropriate treatment, enthusiasm for coordinated voice therapy and voice training as first-line treatment, and acceptance of microsurgical management as appropriate treatment if behavioral management fails.
Discordance between direct and PHA-stimulated chromosome preparations from neonates

Four examples of discordance between karyotypes prepared from direct and PHA-stimulated neonatal blood samples are presented. The specimens were initially studied by direct methods to establish a neonatal karyotype rapidly. The patients are described and the significance of the findings is discussed.
Th17 cells and their associated cytokines in liver diseases

T helper 17 (Th17) cells are a newly identified subset of T helper cells that play important roles in host defense against extracellular bacteria as well as in the pathogenesis of autoimmune disease. The functions of Th17 cells are mediated via the production of several cytokines including interleukin (IL)-17 and IL-22. Recent studies show that the frequency of IL-17(+) cells is significantly elevated in a variety of chronic liver diseases including alcoholic liver disease, viral hepatitis and hepatocellular carcinoma. IL-17 receptor is expressed virtually on all types of liver cells, while IL-22 receptor expression is restricted to epithelial cells including hepatocytes in the liver. IL-17 seems to play an important role in inducing liver inflammation via stimulating multiple types of liver nonparenchymal cells to produce proinflammatory cytokines and chemokines, while IL-22 appears to be an important factor in promoting hepatocyte survival and proliferation.
Phase-shifted pulse sequence for measurement of spin-lattice relaxation in complex spin systems: an improvement

For the measurement of spin-lattice relaxation in complex spin systems, most, if not all, phase and amplitude distortions may be removed by cycling the phase of the inversion pulse in increments of 90 Deg while retaining the phase alternation of the monitoring pulse and the add/subtract mode during signal accumulation. The technique is illustrated by the measurements of the nonselective deuteron spin-lattice relaxation time for CDCl3 (10 mol %) in Merck Licristal Phase V. [on SciFinder (R)]
Raman scattering of laser-deposited amorphous carbon.

Raman scattering of thin laser-deposited amorphous-carbon films reveals significant changes in lower and intermediate spectral regions with respect to rf-sputtered, predominantly threefold a-C. The form of the spectrum differs, however, from the expected spectrum for fourfold, diamondlike a-C. It is suggested that mixed bonds between threefold and fourfold sites in diamondlike materials modify the lower-frequency bond-bending modes and Raman scattering.
Preparation of Quaternary Ammonium Organosilane Functionalized Mesoporous Thin Films

The preparation of surfactant-templated periodic mesoporous silica thin films functionalized with N-((trimethoxysilyl)propyl)-N,N,N-trimethylammonium chloride (TMAC) is described. The supramolecular self-assembly of the triblock copolymer, Pluronic 123, served as a template for the formation of these functionalized silane films. In the as-prepared and extracted conditions, the films exhibited the p6 mm type hexagonal mesostructure with a large unit cell (a = 8.5−9.6 nm). Contraction of the films during heat treatment (250 °C for 2 h) reduced the pore spacing perpendicular to the substrate yielding Fm3m pore ordering, confirmed by X-ray diffraction and transmission electron microscopy. Ellipsometry measurements revealed the films to have thickness of ∼400 nm in the as-prepared condition and ∼300 nm in the heat-treated condition, a total shrinkage of ∼25% perpendicular to the substrate. X-ray photoelectron spectroscopy measurements showed the incorporation of the TMAC to be 76−90% of the amount initially ad...
Locating Spatial Variation in the Association Between Wildland Fire Risk and Social Vulnerability Across Six Southern States

Wildland fire in the South commands considerable attention, given the expanding wildland urban interface (WUI) across the region. Much of this growth is propelled by higher income retirees and others desiring natural amenity residential settings. However, population growth in the WUI increases the likelihood of wildfire fire ignition caused by people, as humans account for 93% of all wildfires fires in the South. Coexisting with newly arrived, affluent WUI populations are working class, poor or otherwise socially vulnerable populations. The latter groups typically experience greater losses from environmental disasters such as wildfire because lower income residents are less likely to have established mitigation programs in place to help absorb loss. We use geographically weighted regression to examine spatial variation in the association between social vulnerability (SOVUL) and wildfire risk. In doing so, we identify “hot spots” or geographical clusters where SOVUL varies positively with wildfire risk across six Southern states—Alabama, Arkansas, Florida, Georgia, Mississippi, and South Carolina. These clusters may or may not be located in the WUI. These hot spots are most prevalent in South Carolina and Florida. Identification of these population clusters can aid wildfire managers in deciding which communities to prioritize for mitigation programming.
Novel phases and transitions in color flavor locked matter

We analyze the phases of dense quark matter at nonzero quark masses. We map out the phase diagrams for charged quark matter as well as charge neutral matter containing leptons. We find that in Color Flavor Locked (CFL) quark matter, the symmetric phase with equal numbers of $u$, $d$ and $s$ quarks is unlikely to occur in nature. Various less symmetric phases with additional meson condensates may play a role in neutron star cores, however, in agreement with the analysis of Bedaque and Sch\"afer. We discuss the implications of these novel color superconducting quark matter phases and their transitions for neutron stars.
Determination of trace elements in zinc by isotope dilution spark source mass spectrometry

Abstract The applicability of the isotope dilution technique in spark source mass spectrometry has been investigated for the determination of Pb, Cu, Cd, Ag, Tl, and Sn in zinc metal. In the procedure developed, a solution of the zinc is spiked with known amounts of stable isotopes of the elements to be determined, and the elements are electrodeposited onto gold wires that subsequently serve as electrodes for the mass spectrographic isotopic analysis. Chemical operations, including isothermal distillation of reagents, dissolution of the zinc, and the electro-deposition step are conducted in a closed system to minimize contamination. The results of the analysis of two NBS zinc standard reference materials include determinations ranging from 11 ppm (11 μg g ) for Pb to as low as 0.02 ppm (20 ng g ) for Sn. It is concluded that this method is of general utility for simultaneous multi-element trace analysis and is especially applicable in providing much needed standardization in spark source mass spectrometry.
Comparison of Simulation and Experiment for Soot Concentration in a 2m Diameter JP-8 Fire

A comparison is made between numerical simulations and experimental data for soot and water vapor concentration in a JP-8 fire. Soot concentration depends on soot generated/destroyed per unit flame area (subgrid soot model) and the overall flame area per unit volume (turbulence treatment). Two different turbulence treatments, a steady RANS variant and an unsteady LES variant, are used to determine the effect of overall flame area per unit volume. The results indicate that the difference in the two turbulence treatments is greater than the difference between the data and either approach.Copyright © 2005 by ASME
Polarography of B12 coenzyme

Abstract The polarography of B 12 coenzyme (5,6-dimethylbenzimidazolylcobamide, DBC coenzyme) has been investigated at the dropping mercury electrode. Exposure of solutions of the coenzyme to light and then to oxygen give polarograms comparable to those of B 12 r and hydroxocobalamin (B 12 a ) respectively. At pH 11.6 the coenzyme gives two reduction waves, at −1.43 and −1.62 V vs . the S.C.E.; in less basic solutions the two waves merge to give one multielectron wave.
Control of Microstructure and Orientation in Solution-Deposited BaTiO3 and SrTiO3 Thin Films

Columnar and highly oriented (100) BaTiO{sub 3} and SrTiO{sub 3} thin films were prepared by a chelate-type chemical solution deposition (CSD) process by manipulation of film deposition conditions and seeded growth techniques. Randomly oriented columnar films were prepared on platinum-coated Si substrates by a multilayering process in which nucleation of the perovskite phase was restricted to the substrate or underlying layers by control of layer thickness. The columnar films displayed improvements in dielectric constant and dielectric loss compared to the fine-grain equiaxed films that typically result from CSD methods. Highly oriented BaTiO{sub 3} and SrTiO{sub 3} thin films were fabricated on LaAlO{sub 3} by a seeded growth process that appeared to follow a standard two-step growth mechanism that has been previously reported. The film transformation process involved the bulk nucleation of BaTiO{sub 3} throughout the film, followed by the consumption of this matrix by an epitaxial overgrowth process originating at the seed layer. Both BaTiO{sub 3} and PbTiO{sub 3} seed layers were effective in promoting the growth of highly oriented (100) BaTiO{sub 3} films. Based on the various processing factors that can influence thin film microstructure, the decomposition pathway involving the formation of BaCO{sub 3} and TiO{sub 2} appeared tomore » dictate thin film microstructural evolution.« less
Prevalence of Blue Spot Disease (Esocid Herpesvirus-1) on Northern Pike and Muskellunge in Wisconsin

Abstract Blue spot disease (esocid herpesvirus-1) was observed in populations of northern pike Esox lucius and muskellunge Esox masquinongy in northern Wisconsin during the 1984–1992 spring spawning periods. Prevalence of blue spot disease was as high as 34% for northern pike and 29% for muskellunge. Prevalence differed among lakes and between sexes in some lakes. In general, larger and older northern pike were less likely to have observable lesions. The pathogenesis of blue spot disease is unknown. Clinical signs are present for only a short period when water temperatures are between 2 and 13°C, and they are not visible shortly after fish spawn, when water temperatures reach 14°C.
Spatial Variability in Soil Microbial Communities in a Nitrogen-Saturated Hardwood Forest Watershed

The long-term reference watershed (WS4), at Fernow Experimental Forest, West Virginia, displays symptoms ofN saturation despite considerable spatial heterogeneity in soil properties, such as texture, N pools, and cycling rates. We identified a weathering gradient of three sites within WS4 by assessing differences in clay content across a common geologic substrate. Across these sites (LN, MN, and HN), NO 3 production rates vary significantly (low, medium, and high nitrification, respectively) and are negatively related to clay content. It is unknown whether microbial communities vary across these sites and contribute to variability in N0 3 production. This study characterized soil microbial communities along this gradient and assessed factors potentially important in explaining microbial composition. We sampled mineral soil from each of the sites, analyzing for moisture, pH, organic matter, extractable N, and microbial biomass and community composition via phospholipid fatty acid (PLFA) analysis. Analysis of variance and canonical correspondence analysis indicated that microbial community composition varied among sites, with a predominance of fungal markers (18:2n6 and 18:1n9c) at the most weathered LN site and Gram negative bacteria (18:1n7c) at the less weathered MN and HN sites. Accordingly, the fungi/bacteria ratio increased in the direction of LN plots in ordination space. Correlations between measured environmental parameters and PLFA data suggest that acidic conditions and low NO 3 abundance at the LN site have selected for fungal dominance, although other important factors known to exert an influence on soil microbial communities, such as differences in plant community and clay and organic matter content, may also be playing a role in determining the observed patterns.
Learning and unlearning: the education of teacher educators

Abstract Despite the many expectations that US and other teacher educators around the world are striving to meet, there has been little attention to development of a curriculum for educating teacher educators, or to local and larger policies that might support the development of what teacher educators need to know and do in order to meet the complex demands of preparing teachers for the 21st century. In this article, Cochran-Smith analyzes four teacher educator communities in different contexts and entry points across the career lifespan. She makes the case that the education of teacher educators is substantially enriched when inquiry is a stance on the overall enterprise of teaching, schooling, and teacher education.
The Explicit Teaching of Reading Comprehension in Science Class: A Pilot Professional Development Program.

This pilot study aimed to address persistent gaps in the research regarding effective professional development models associated with reading comprehension pedagogy in content area classrooms (scie...
Auditory amplification: outer hair cells pres the issue

Active feedback mechanisms in the ears of mammals amplify and tune the auditory response to sound stimuli, allowing these organisms to enjoy both exquisite sensitivity and sharp frequency selectivity. A requisite component of this feedback pathway has recently been identified. Targeted deletion of pres, the gene that encodes the novel membrane-bound motor protein prestin, has revealed a hundred-fold loss in hearing sensitivity suggesting that it might be part of the elusive cochlear amplifier.
Effects of a prevention program for divorced families on youth cortisol reactivity 15 years later

Objective: We examined whether an empirically based, randomised controlled trial of a preventive intervention for divorced mothers and children had a long-term impact on offspring cortisol regulation.Design: Divorced mothers and children (age 9–12) were randomly assigned to a literature control condition or the 11-week New Beginnings Program, a family-focused group preventive intervention for mothers and children in newly divorced families.Main Outcome Measures: Fifteen years after the trial, offspring salivary cortisol (n = 161) was measured before and after a social stress task.Results: Multilevel mixed models were used to predict cortisol from internalizing symptoms, externalizing symptoms, group assignment and potential moderators of intervention effects. Across the sample, higher externalizing symptoms were associated with lower cortisol reactivity. There was a significant group-by-age interaction such that older offspring in the control group had higher reactivity relative to the intervention group,...
An Elastic Rod Representation for the LacI-DNA Loop Complex

The well-recognized Lac repressor protein (LacI) regulates transcription by bending DNA into a loop. In addition to the known role of DNA flexibility, there is accumulating evidence suggesting that the flexibility of LacI also plays a role in this gene regulation. Here we extend our elastic rod model for DNA (previously used to model DNA only) to represent LacI. Specifically, we represent sites of concentrated flexibility in the protein with flexible elastic rod domains; and we represent relatively rigid domains of the protein with stiff elastic rod domains. Our analysis shows the sensitivity of looping energetics to the degree of flexibility within the protein over a large range of DNA lengths. In addition, we show that the predicted energetically dominant binding topology (A ) remains upon introducing protein flexibility.Copyright © 2011 by ASME
The neutralization of acidic coal mine lakes by additions of natural organic matter: a mesocosm test

Cylindrical polyethylene enclosures 3 m in length and 1 m in diameter reaching from the surface to the bottom were constructed in an acid (pH=3.1) lake on a coal surface mine in southern Illinois. Wheat straw was added to the enclosures to test the effects of dissimilatory sulfate reduction on water chemistry. Added straw increased sulfide concentrations, raised pH to 6.5, reduced O2 and increased acid neutralizing capacity of the enclosed water columns when compared with a control enclosure and with the open lake. Generation of acid neutralizing capacity exceeded the standing stock of sulfide indicating that sulfide was removed either by precipitation of FeS or outgassing of H2S. The pH and acid neutralizing capacity within the enclosures eventually returned to the level of the surrounding lake because of water exchange around the enclosure walls. Our results show that additions of organic matter to acid surface mine lakes result in the generation of acid neutralizing capacity.
Coherence in electronically excited dimers. III. The observation of coherence in dimers using optically detected electron spin resonance in zero field and its relationship to coherence in one-dimensional excitons

The observation of coherent dimers in their excited triplet state is reported for a molecular crystal of 1,2,4,5-tetrachlorobenzene at low temperatures (below 4.2 K). Utilizing the theory developed in our previous paper, the coherence time (10^-6 sec) and the anisotropy of the resonance interactions in the excited state were established. The identification of the dimer as translationally equivalent, from the zero-field optically detected magnetic-resonance spectra, establishes the effective dispersion for the triplet exciton band of the neat crystal. Morover, the magnitude of the resonance transfer time was shown to be much less than the coherence time: the dimer is coherent for a period of 10^5 times that associated with the stochastic limit.
The State and Dilemmas of Security: the Middle East and the Balkans

This article argues that even if the state represents a solution to the security needs of one group of people, it may be a source of threat to another. This is so because the construction of the state is necessarily an exclusive process, and those who are excluded in some cases become a source of threat. In addition, the state sometimes represents a threat to its own people. In sum, on the basis of an existing critical literature within security studies, the article questions the role of the state in maintaining security. In this context, it utilizes the debate on identity formation to defend the necessity of constructing open and inclusive political spaces. It then applies this theoretical discussion to the cases of the Middle East and the Balkans, and argues that the alternative to the sovereign state that is being put in place in the Balkans might represent a valuable example for the Middle East.
Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope

Abstract Photometric properties of 4 rings and 16 satellites of Uranus are presented, based on 41 Hubble Space Telescope images taken in 1997. Up to 25 filters per object covered the wavelength range 0.27–2 μm. The whole range of phase angles observable from Earth (0.03–3°) was probed. Reflectivities were calibrated on an absolute scale to typically 4% accuracy. Below 1 μm, derived geometric albedos of major satellites are typically 30% higher than previously reported due to previously unobserved steep upturns of the phase curve shortward of 0.2° phase angle, possibly caused by coherent backscatter. Portia is slightly oblong and Juliet and Belinda are very oblong based on their rotational lightcurves. Puck displays a weak spectral feature indicative of water ice absorption. Cordelia and Ophelia were recovered very close to the positions predicted from their gravitational influence on the e ring. They have not been observed since 1986. Subtle color variations within the satellite system were confirmed. Throughout the uranian system, the slope of phase curves below 1° phase angle displays a strong correlation with the albedo and a strong anticorrelation with the slope at higher phase angles. Similar correlations were found for Hapke parameters. The brightness of 20 members of the uranian system is presented in functional form for a wide range of wavelengths, phase angles, and orbital longitudes.
Dynamic Control Model Calculation: A Model Generation Architecture for Autonomous On-Orbit Assembly

Autonomous on-orbit assembly is a key technology that can enable many space applications in a more cost-effective and lower risk manner than human-assisted assembly. During an assembly sequence, an assembler robot can undergo multiple configurations as it attaches to and releases individual modules. This paper addresses how to account for the mass and stiffness property variations that occur with changes in configuration. Proper model generation for each configuration is critical to maintain control system stability and efficiency. A design, called dynamic control model calculation, is presented in this paper to address a gap where models are aggregated online based on module mass property information. This design uses module information obtained at the time of attachment to generate the model for the current configuration onboard. The design, both framework and algorithm parameterization, has been successfully implemented and validated on hardware. Hardware results show a tracking error performance impro...
Sample preparation methods and replicability in macroscopic charcoal analysis

We explored the use of hydrogen peroxide (H2O2) of different strengths (1, 3, 6, and 9%) in the preparation of lake-sediment samples for macroscopic charcoal determination. In previous work we found that soaking sediment samples in 3% H2O2 for 24 h disaggregates samples and removes or bleaches some non-charred organic material, making it easier to distinguish macroscopic charcoal particles from dark, non-charred organic matter. To determine whether this procedure alters charcoal particle abundances and size distributions, we tested the procedure on wood and grass samples containing a known number of laboratory-produced charcoal particles from different size classes (250–500, 500–1,000, and 1,000–2,000 µm). For both sample types, we found that post-treatment numbers were not statistically different from pre-treatment numbers. However, application of hydrogen peroxide solutions of 3, 6, and 9% to fossil charcoal assemblages in a sediment core from northwestern Costa Rica reduced charcoal concentrations markedly, by bleaching or removing particles that were not fully charred. We also tested the replicability of charcoal counts by conducting enumerations on multiple samples from the same stratigraphic depths in a core. Horizontally adjacent samples from the same core may vary in charcoal concentration. This finding has implications for establishing sample volume in macroscopic charcoal analysis.
Clearance of apoptotic corpses

Apoptotic corpses can be engulfed and cleared by many other cell types in addition to 'professional' phagocytes such as macrophage. Studies of several organisms have contributed to the understanding of apoptotic corpse engulfment. Two partially redundant engulfment pathways have been characterized that act even in non-professional phagocytes to promote corpse engulfment. This review summarizes some recent progress in signaling by these pathways, including the exposure of eat-me-signals on apoptotic cells, and insights from Drosophila on the roles of the bridging receptor Six Microns Under, the non-receptor tyrosine kinase Shark, and store-operated calcium release in the Draper/Ced-1 pathway of corpse recognition and internalization. The mechanism of apoptotic phagosome maturation is outlined, and possible connections between corpse engulfment and proliferation, cell competition, and immunity are discussed.