cssi/SciSciGPT-SciSciNet huggingface dataset:
Nest construction, ambient temperature and reproductive success in a cavity-nesting bird

Nest construction is a widespread behaviour that is a critical fitness investment in many taxa. Nests provide stable environments for offspring production, development and at times adult survival. Avian nest structure and composition has been linked to insulative properties and the reduction of energetic requirements for incubating females. However, it is unclear how and why nest structure varies across landscapes within and between species, especially in cavity-nesting species. Here we examined nest size in a secondary cavity nester, the mountain chickadee, Poecile gambeli. Nests were measured across two years at two elevations varying in ambient temperature to test whether variation in nest size was associated with local ambient temperatures and internal nest cavity microclimate. Despite both elevations having high variation in ambient temperature during nest building in both years, there were no significant relationships between multiple nest measurements and temperature. Nest size was highly consistent between years within females, suggesting that individual females are the best predictor of nest size. Large variation in nest size, internal nest cavity microclimate temperature and ambient temperature during development in one year was not associated with significant differences in reproduction; but fluctuating asymmetry, a measure of developmental stress, was significantly lower in fledglings at the higher-elevation site independent of temperature. However, there were no significant differences between elevations in the second year for any reproductive parameter. Overall, our results suggest that chickadees do not adjust nest size in response to large differences in ambient or microclimate temperature and that large variation in nest size, both across and within sites, is a result of consistent individual preferences, which do not seem to have clear fitness consequences.
Evidence for a Link Between Fe K-alpha Emission Line Strength and QPO Phase in a Black Hole

In X-ray binaries, the frequencies revealed in X-ray quasi-periodic oscillations (QPOs) are often interpreted as characteristic frequencies in the inner accretion disk, though the exact oscillation mechanism is unknown at present. Broadened Fe K-alpha lines are also excellent diagnostics of the inner accretion flow, if their broadening is indeed due to inner disk reflection. Herein, we present two cases where the flux and equivalent width of the Fe K-alpha emission lines in spectra of the Galactic black hole GRS 1915+105 vary with the phase of strong 1 Hz and 2 Hz QPOs in the X-ray flux. These results provide strong evidence that both QPOs and the Fe-alpha lines originate in the inner disk. If the 1 Hz QPO is only a Keplerian orbital frequency, the QPO comes from a distance of 84 +/- 26 R_Schw from the black hole; the 2 Hz QPO implies a radius of 50 +/- 15 R_Schw. At these radii, relativistic shaping of a disk line is inevitable. Moreover, the link holds in radio-bright and radio-faint phases, signaling that in systems like GRS 1915+105, the Fe K-alpha line is a disk line and not a jet line as per SS 433. A particularly interesting possibility is that a stable warp in the inner disk, e.g. due to Lense-Thirring precession, may produce the observed QPOs and line modulations. More broadly, the FeK-QPO link provides an unprecedented mechanism for revealing the inner accretion flow and relativistic regime in accreting systems, in that it gives two measures of radius: for a given disk QPO model, the frequency translates into a specific radius, and relativistic line models yield radii directly.
Caffeine and Theophylline Inhibit β-Galactosidase Activity and Reduce Expression in Escherichia coli.

The β-galactosidase enzyme is a common reporter enzyme that has been used extensively in microbiological and synthetic biology research. Here, we demonstrate that caffeine and theophylline, common natural methylxanthine products found in many foods and pharmaceuticals, negatively impact both the expression and activity of β-galactosidase in Escherichia coli. The β-galactosidase activity in E. coli grown with increasing concentrations of caffeine and theophylline was reduced over sixfold in a dose-dependent manner. We also observed decreasing lacZ mRNA transcript levels with increasing methylxanthine concentrations in the growth media. Similarly, caffeine and theophylline inhibit the activity of the purified β-galactosidase enzyme, with an approximately 1.7-fold increase in KM toward o-nitrophenyl-β-galactoside and a concomitant decrease in vmax. The authors recommend the use of alternative reporter systems when such methylxanthines are expected to be present.
Calculation and Analysis of Heat Dissipation Performance of Welded IGBT Device

Power electronic device IGBT is an important part of flexible DC converter valve. Due to the small size of IGBT chip, the high blocking voltage and high conduction current, its heat dissipation performance under the condition of repeatedly switching on/off is directly related to the system operation reliability. Therefore, it is necessary to focus on the analysis of the thermal performance of the device. According to the welding IGBT commonly used in DC converter, the transient hyperbolic method is used to test its thermal resistance. The thermal resistances of each layer as well as the total resistance are determined according to the structure function. In order to analyze the influence of various parts of the device on heat dissipation performance in detail, a complete 3D model of IGBT power electronic devices was established, including chip, substrate, base-plate, silica gel and shell. By calculating the steady state temperature field of the device, the results show that the reasonable heat convection coefficient on the bottom plate is the key factor to determine the heat dissipation performance, and the silicon heat convection coefficient has little effect on the heat dissipation performance. By calculating the transient temperature field, the results show that the maximum temperature difference among IGBTs in the device is about 3 °C, and the maximum temperature difference among diodes is less than 1 °C, which indicates that the device has good temperature uniformity and thermal stability.
Interfacial energies in nanocrystalline complex oxides

Abstract This paper presents a brief description of the role of interfacial energies in the understanding and control of nanocrystalline complex oxides in both particulate and bulk forms. Interfacial energies are fundamental parameters in microstructural evolution processes such as phase transformation, grain growth, and sintering. Although generally considered constant driving forces, experimental evidences confirm the possibility of intentional modification of both surface and grain boundary energies in oxide systems via ionic doping. This opened the perspective for a systematic understanding of their roles as refining parameters in microstructural control during processing and in operation. In this work, the theoretical framework in the context of Gibbs adsorption isotherm and the formation of dopant excess (i.e. interfacial solute segregation) is introduced in a similar manner as formalized for liquid systems. A collection of data demonstrating interfacial energy control in oxides is presented and discussed in terms of microstructural relationships with specific examples. The data advocates for a paradigm shift on nanocrystalline processing control from a traditionally kinetically oriented perspective to a more balanced viewpoint in which thermodynamics can play a governing role, especially at moderate temperatures. The work is not an extensive review, but rather has the goal of introducing the reader to this growing research topic.
Bayesian model averaging sliced inverse regression

Abstract As a popular sufficient dimension reduction method, sliced inverse regression (SIR) (Li, 1991) involves all the predictors. We propose Bayesian model averaging SIR when the central space only involves a subset of the predictors.
Is peripartum magnesium sulfate associated with a reduction in postpartum depressive symptoms

BACKGROUND The prevention of postpartum depression is an important area of investigation given its association with major maternal and neonatal sequelae, yet few evidence-based treatments to reduce the frequency of postpartum depression are used. Recent data suggest that N-methyl-D-aspartate receptor antagonists may lead to rapid improvement of depressive symptoms lasting up to 2 weeks. We hypothesized that the N-methyl-D-aspartate receptor antagonist magnesium sulfate would elicit antidepressant effects subsequent to its receipt by women receiving peripartum seizure prophylaxis for a hypertensive disorder of pregnancy. OBJECTIVE This study aimed to compare the frequency of depressive symptoms at 2 weeks and 6 weeks after delivery between women who did and did not receive peripartum magnesium sulfate for a hypertensive disorder of pregnancy. STUDY DESIGN This prospective cohort study included women with a hypertensive disorder of pregnancy at ≥34 weeks’ gestation with singleton gestations. Magnesium sulfate for seizure prophylaxis was administered at the obstetrician's discretion. The Quick Inventory of Depressive Symptomatology survey was administered before hospital discharge and again at 2 weeks and 6 weeks after delivery to assess for postpartum depressive symptoms. The primary outcome for this study was the change in Quick Inventory of Depressive Symptomatology score from baseline to 2 weeks after delivery, which was analyzed both continuously and categorically (any symptom worsening vs stability or improvement). Secondary outcomes included the change in Quick Inventory of Depressive Symptomatology score from baseline to 6 weeks after delivery and the proportion of women who experienced an increase in Quick Inventory of Depressive Symptomatology score at 6 weeks after delivery. RESULTS Of the 342 women enrolled, 39% (n=134) received magnesium sulfate. Compared with women who did not receive magnesium, women who received magnesium had a significantly smaller change in their mean Quick Inventory of Depressive Symptomatology score (0.6±3.4 vs 1.6±3.0; P=.015) and also were less likely to have an increase in Quick Inventory of Depressive Symptomatology score at 2 weeks after delivery (52% vs 67%; P=.022). These differences were not present at 6 weeks after delivery. After controlling for potential confounders, women who received magnesium continued to have a lower odds of having an increased Quick Inventory of Depressive Symptomatology score from baseline at 2 weeks after delivery than women who did not receive magnesium (adjusted odds ratio, 0.88; 95% confidence interval, 0.78–0.98). CONCLUSION Peripartum magnesium was associated with less of an exacerbation in depressive symptoms in the immediate postpartum period. Given the implications of postpartum depression on maternal and child health and the lack of existing prophylaxis, randomized trials should examine this novel potential prophylactic therapy.
“We’re More Than a Daycare”: Reported Roles and Settings for Early Childhood Professionals and Implications for Professionalizing the Field

In the US, recent efforts have focused on professionalizing the field of early childhood. One way to indicate professionalism is through the terms used to describe both the field and the workers. However, few have examined how practitioners or researchers describe early childhood professionals’ work. Using multiple data sources and analytic strategies, we examined the ways that those working with young children described their role and setting, as well as how these were described in research and practitioner journals. “Teacher” was the preferred term for both journals and professionals, and terms for setting reflected traditional K-12 school structures. Professionals linked these terms to the idea that early childhood education was teaching and preparing children for formal schooling. Many contrasted their work with daycare and babysitting, noting that planning, curriculum use, expertise, program quality, funding mechanisms, professionalism, and early childhood as an important developmental period all contributed to their roles as teachers in preschool settings. Implications are discussed.
Effect of Temperature on the Surface Properties of Aqueous Solution of Arachidonic Acid

The surface tension of aqueous solution of arachidonic acid (AA) was measured with a Du Nouy tensiometer at pH 7.80 and various temperatures, and the effect of temperature on the surface properties of AA was investigated. The value of critical micelle concentration (cmc) of AA increased and the surface tension at the cmc, γcmc, decreased as the temperature was raised from 30 to 60°C. The Langmuir constant k concerning the strength of adsorption decreased, the saturated adsorption ammount of AA, Γ∞, at the air-water interface decreased, and the area occupied by an AA molecule at the saturated adsorption, A∞, increased as the temperature was raised. The standard free energy for the adsorption, ΔGad, was of negative value, and the absolute value |ΔGad| became larger as the temperature was raised because of the negative value of the standard enthalpy change ΔHad and the positive value of the standard entropy change ΔSad. The standard free energy of micellization, ΔGm, was of negative value, and it was similarly found that |ΔGm|became larger as the temperature was raised because of the negative value of the standard enthalpy change ΔHm and the positive value of the standard entropy change ΔSm.
Imperfect Arbitrage with Wealth Effects

This paper presents a continuous-time equilibrium model of arbitrage, based on risk aversion of perfectly competitive arbitrageurs and imperfect capital flows to arbitrage activity. Arbitrageurs make profits from trading against noise trading. Under the assumption of logarithmic utility, arbitrageurs' degree of absolute risk aversion changes with their wealth. When arbitrageurs suffer capital losses due to unfavorable shocks, their willingness to bear risks decreases, and they liquidate some of their risky positions. The liquidation of arbitrageurs' positions tends to amplify the original shocks, and thus generates a wealth effect. The wealth effect can cause arbitrage to be destabilizing in the sense that price volatility can be larger when arbitrageurs are present than when no arbitrageurs exist. The wealth effect offers a mechanism to explain the financial crisis of Long Term Capital Management in 1998. It also produces a motivation for risk managers to take into account the risks created by the trading of other market participants. The model shows that arbitrageurs reduce volatility and provide liquidity on average, but only in extreme circumstances does arbitrage become destabilizing. The wealth effect also provides an explanation for excess volatility and stochastic volatility. In equilibrium, markets are inefficient in the sense that the Sharpe ratio is not driven to zero by arbitrage activity. The long-run mean of the squared Sharpe ratio is primarily determined by the impatience level of arbitrageurs. The equilibrium wealth process for arbitrageurs is endogenously determined. Larger fundamental volatility deters wealth accumulation in arbitrage activity, while larger noise trading volatility induces more.
Studies on enzymes from parasitic helminths. I. Purification and physical properties of malic enzyme from the muscle tissue of Ascaris suum.

Abstract 1. 1. A procedure has been developed for the isolation of the mitochondrial malic enzyme ( l -malate: NAD+ oxidoreductase (decarboxylating), EC 1.1.1.39) from muscle tissue of the roundworm Ascaris suum. 2. 2. The enzyme is adjudged to be homogeneous by the criteria of analytical ultracentrifugation, zone electrophoresis, isoelectric focusing and rechromatography. 3. 3. Concomitant with the homogeneity studies the following physical parameters were established: s020,w = 8.9·10−13s; D20,w = 3.6·10−7cm2·s−1; apparent isoelectric pH = 6.63. 4. 4. Sedimentation velocity, sedimentation equilibrium ultracentrifugation, as well as analytical gel filtration, yield a molecular weight of 250 000 for the native enzyme. The enzyme can be dissociated into four identical monomers of molecular weight 64 000. 5. 5. The isolated enzyme utilizes NAD+ more effectively than NADP+ in the decarboxylation of malate. Oxaloacetate is not decarboxylated in the presence of either coenzyme. 6. 6. The enzyme exhibits an absolute requirement for Mn2+ or Mg2+ and is inhibited by (NH4)2SO4. The inhibition is partially reversed by Mn2+.
Trypsin bound to sephadex beads. A tool for neuronal cell dissociation.

Abstract Trypsin covalently bound to Sephadex beads was used for the histolytic dissociation of neuronal cell bodies from rat brain. In contrast to unbound trypsin, the bound enzyme did not bind to the isolated cells. The histolytic efficiency of the bound enzyme, measured in terms of cell yields, was approx. 100-fold greater than the free enzyme.
Vision, Identity, and Career in the Clinical and Translational Sciences: Building upon the Formative Years

This paper is the second in a five-part series on the clinical and translational science educational pipeline. It focuses on the role that Clinical and Translational Science Award (CTSA) programs can play in supporting science, technology, engineering, and math (STEM) education in primary and secondary schools, as well as in facilitating these interests during transition to undergraduate training. Special emphasis should be placed on helping to form and sustain an identity as a scientist, and on instilling the persistence necessary to overcome numerous barriers to its actualization. CTSAs can contribute to cementing this sense of self by facilitating peer support, mentorship, and family involvement that will reinforce early educational decisions leading to clinical and translational science research careers. Meanwhile, the interests, skills, and motivation induced by participation in STEM programs must be sustained in transition to the next level in the educational pipeline, typically undergraduate study. Examples of CTSA collaborations with local schools, businesses, interest groups, and communities at large illustrate the emerging possibilities and promising directions with respect to each of these challenges.
Modulation of mitochondrial gene expression in pulmonary epithelial cells exposed to oxidants.

Oxidants are important in the regulation of signal transduction and gene expression. Multiple classes of genes are transcriptionally activated by oxidants and are implicated in different phenotypic...
Methods for Evaluating the Validity of Test Scores for English Language Learners

In the United States, when English language learners (ELLs) are tested, they are usually tested in English and their limited English proficiency is a potential cause of construct-irrelevant variance. When such irrelevancies affect test scores, inaccurate interpretations of ELLs' knowledge, skills, and abilities may occur. In this article, we review validity issues relevant to the educational assessment of ELLs and discuss methods that can be used to evaluate the degree to which interpretations of their test scores are valid. Our discussion is organized using the five sources of validity evidence promulgated by the Standards for Educational and Psychological Testing. Technical details for some validation methods are provided. When evaluating the validity of a test for ELLs, the evaluation methods should be selected so that the evidence gathered specifically addresses appropriate test use. Such evaluations should be comprehensive and based on multiple sources of validity evidence.
Scalar Di-Pion Resonance and the Nucleon Axial Form Factor

It is shown that the inclusion of a scalar dipion resonance (395 plus or minus 10 Mev) can improve the agreement between theoretical and experimental information on the nucleon axial form factor. (R.E.U.)
XLIII.—Descriptions and records of bees.—XXIII

(1914). XLIII.—Descriptions and records of bees.—LXIII. Annals and Magazine of Natural History: Vol. 14, No. 83, pp. 361-369.
On Teichmüller’s theorem on the quasi-invariance of cross ratios

Teichmuller’s theorem gives necessary and sufficient conditions for mapping one ordered quadruple by aK-quasiconformal map onto a second ordered quadruple. We give a simple non-computational proof of the necessity part. We then characterize such extremal mappings, and obtain as a consequence a new formula for the modular function, with leads to a very simple derivation of the known expression for the Poincare metric on the thrice-punctured sphere.
Dependence of computed trajectory on step-size in a nonlinear dynamic system: An investigation into cutting tool dynamics

The nonlinear model of an orthogonal cutting process devised by Grabec is studied to demonstrate the importance of choosing an appropriate step-size and evolutionary algorithm for numerically integrating a system of nonlinear differential equations. Two different algorithms are used for computing the system trajectory, and the dependence of the phase portrait on the step-size is shown. A qualitative understanding to connect the proper step-size and the system nonlinearity is established.
Finite type knot invariants and the calculus of functors

We associate a Taylor tower supplied by the calculus of the embedding functor to the space of long knots and study its cohomology spectral sequence. The combinatorics of the spectral sequence along the line of total degree zero leads to chord diagrams with relations as in finite type knot theory. We show that the spectral sequence collapses along this line and that the Taylor tower represents a universal finite type knot invariant.
Lipid‐induced conformational changes in glucagon, secretin, and vasoactive intestinal peptide

The CD of glucagon, secretin, and vasoactive intestinal peptide has been studied as a function of temperature in water and in aqueous solutions of dodecyl sulfate, phosphatidyl glycerol, and L-α-phosphatidic acid (dipalmitoyl). The anionic detergent and lipids induce helix formation in all three peptides, with the amount of induced helical content increasing in the order glucagon < secretin < vasoactive intestinal peptide. These observations are subject to quantitative rationalization using a matrix formulation for the configuration partition function. In this formulation the major conformational consequences of the interaction with anionic lipids or detergents is an increase in the probability for helix formation by arginyl, histidyl, and lysyl residues. The region in which helix formation is maximal is found to be at amino acid residues 13–20 in all three peptides. Other studies have implicated this portion of the polypeptide chain in receptor binding. Thus, the helical segment induced by interaction with anionic lipids may play an important physiological role.
Occupational Stressors in Military Service: A Review and Framework

The identification of stressors and the evaluation of their likely severity in the different settings and phases of military service are essential requirements for developing a comprehensive unders...
Efficacy of an HIV/AIDS and HIV testing video for Spanish-speaking Latinos in healthcare and non-healthcare settings.

We assessed the efficacy of a Spanish-language HIV/AIDS and HIV testing video as a substitute for comparable orally-delivered information in healthcare and non-health care settings for Spanish-speakers regardless of health literacy level. In a non-inferiority clinical trial, Spanish-speaking Latinos from an emergency department, a clinic, and community-based organizations were randomly assigned to receive HIV/AIDS and HIV testing information orally or from a video. Comprehension of the information was measured using a questionnaire. Of the 150 participants, 39 % met criteria for lower health literacy and 75 % previously had been tested for HIV. Mean scores on the questionnaire for the video (20.4; 95 % CI 19.5 ~ 21.3) and the orally-delivered information arms (20.6; 95 % CI 19.7 ~ 21.5) were similar (Δ = −0.15; 95 % CI −1.4 ~ 1.1). Mean scores among lower health literacy participants also were similar (18.3 (video) vs. 19.6 (in-person); p < 0.30). This Spanish-language video is a viable substitute for orally-delivered HIV/AIDS and HIV testing information.
Young woman with a four-year history of epilepsy and progressive focal cortical atrophy — What is the diagnosis?

The pathogenesis of disease progression in drug-refractory epilepsy is poorly understood. We report the case of a young woman with a four-year history of epilepsy that progressed rapidly as evidenced by the development of progressive focal cortical atrophy. She underwent biopsy that showed perinatal ischemia and a prominent inflammatory response, including T-cell infiltration and microglial activation. There was no consensus reached on the final diagnosis although the hypothesis of dual pathology (adult variant of Rasmussen's encephalitis and perinatal stroke) was considered. The possible role of inflammation in the progression of epilepsy caused by a “static” lesion (perinatal stroke) is discussed.
Surface Energy Fluxes of the South Atlantic Ocean

Abstract Fluxes of sensible, latent and radiational energy and momentum across the surface of the South Atlantic Ocean have been calculated by substituting ship meteorological observations into bulk aerodynamic and empirical radiation equations. Upper-air measurements of humidity and temperature have been used to supplement the surface empirical infrared radiation formula. North Atlantic fluxes have been updated using upper-air humidities and the same technique. Charts of annual fluxes and meteorological variable averages are presented and discussed in terms of meteorological conditions, oceanic heat advection, upwelling, and horizontal mixing of water in the various regimes of the South Atlantic. Comparisons between meteorological conditions, oceanic currents, and fluxes over the North and South Atlantic have been made. Summations of total heat flux show that the cold South Atlantic gains 4.7 × 1014 W, while the warm North Atlantic loses 6.6 × 1014 W. Oceanographic calculations based on currents and temp...
Precis of Philosophy and Neuroscience: A Ruthlessly Reductive Account

This book precis describes the motives behind my recent attempt to bring to bear “ruthlessly reductive” results from cellular and molecular neuroscience onto issues in the philosophy of mind. Since readers of this journal will probably be most interested in results addressing features of conscious experience, I highlight these most prominently. My main challenge is that philosophers (even scientifically-inspired ones) are missing the nature and scope of reductionism in contemporary neuroscience by focusing exclusively on higher-level cognitive neuroscience, and ignoring the discipline's cell-physiological and molecular-biological core.
Asking Different Questions: Critical Analyses and Reading Research

The author describes two research frames—functionalist research and critical analyses—focusing on the different questions they raise. Her purpose is to suggest that reading researchers must extend the tendency to conduct policy-driven research toward critical and pragmatic questions about reading education, research, and policy. [Note: This article is reprinted in Reading Education Policy. www.reading.orgpublicationsbbvbooksbk568]
Cellular blue nevus. Clinicopathologic study of forty-five cases.

Some uncertainties exist regarding the natural history and diagnosis of cellular blue nevi. To clarify this situation, 45 cellular blue nevi and 147 blue nevi were studied. The usual history was that of a long-standing sacrococcygeal or gluteal mass in a young woman. Two extracutaneous tumors and six lesions in Negroes, not heretofore reported, are presented. Clinically cellular blue nevi were uniformly misdiagnosed and microscopically confused with malignant melanoma seven times. This resulted in one mastectomy. Prolonged follow-up studies showed only one recurrence and no metastases following conservative surgical treatment. Reports from 267 cellular blue nevi, including 14 which had given “metastases,” and 12 malignant blue nevi are reviewed. Comprehensive criteria are proposed for the differential diagnosis of cellular blue nevus and malignant melanoma. The ultrastructural characteristics of the melanosomes of cellular blue nevus cells are discussed.
Do Job Corps Performance Measures Track Program Impacts

Since the 1993 Government Performance and Results Act, performance measurement systems based on short-term program outcomes have been increasingly used to assess the effectiveness of federal programs. This paper examines the association between program performance measures and long-term program impacts, using nine-year follow-up data from a recent large-scale, national experimental evaluation of Job Corps, the nation's largest federal job training program for disadvantaged youths. Job Corps is an important test case because it uses a comprehensive performance system that is widely emulated. We find that impacts on key outcomes are not associated with measured center performance levels. Participants in higherperforming centers had better outcomes; however, the same pattern holds for comparable controls. Thus, the performance measurement system is not achieving the goal of ranking and rewarding centers on the basis of their ability to improve participant outcomes relative to what these outcomes would have been otherwise. © 2008 by the Association for Public Policy Analysis and Management.
Polynucleotide Phosphorylysis and Synthesis by Lysed Cells of Micrococcus Iysodeikticus

AQUEOUS extracts of Micrococcus lysodeikticus possess a highly active enzyme capable of polymerizing mononucleotides reversibly1. In addition, the bacterial ribonucleic acid is readily phosphorylysed by this enzyme in the presence of inorganic phosphate. Because of these facts, we have attempted in a few preliminary experiments to evaluate the part this enzyme system may play in modifying the properties or content of bacterial cell ribonucleic acid during lysis of the cells and extraction procedures. In these experiments we have measured the acid-insoluble and acid-soluble fractions extractable from the cells during and after lysis in tris buffer, phosphate buffer, and in the presence of adenosine diphosphate in tris buffer, all experiments at pH 9.5. The cells were harvested from submerged 48-hr. cultures2 and washed three times in 0.5 per cent sodium chloride. The concentration of cells was selected empirically by choosing a value which would, after complete lysis, yield an optical density of approximately 1.0 at 260 mµ for the acid-insoluble material when dissolved in 3 ml. of tris solution, pH 8.0, 0.1 M.
INTRINSIC POLARIZATION AND ROTATIONAL DEPOLARIZATION OF FLUORESCENCE OF DNA BASES IN AQUEOUS SOLUTION AT ROOM TEMPERATURE

— A counting procedure is described for determining the polarization characteristics of very weak emission. The degree of polarization of weak emission of DNA bases in aqueous solution at room temperature is found to he high and positive, and shows an inverse correlation with their emission quantum yields which can be understood in terms of a competition between emission lifetimes and rotational relaxation times. For 5-methylcytosine the emission quantum yield can be changed by varying the acidity and the corresponding degrees of polarization show the behavior expected from Perrin's relation. The ratio τo/τrot is discussed in terms of anisotropic relaxation and calculations of τ0.
Temperature dependence of domain motions of calmodulin probed by NMR relaxation at multiple fields.

Interdomain motions of Ca2+-ligated calmodulin were characterized by analyzing the nuclear magnetic resonance 15N longitudinal relaxation rate R1, transverse relaxation rate R2, and steady-state {1H}−15N NOE of the backbone amide group at three different magnetic field strengths (18.8, 14.1, and 8.5 T) and four different temperatures (21, 27, 35, and 43 °C). Between 35 and 43 °C, a larger than expected change in the amplitude and the time scale of the interdomain motion for both N- and C-domains was observed. We attribute this to the shift in population of four residues (74−77) in the central linker from predominantly helical to random coil in this temperature range. This is consistent with the conformation of these residues in the calmodulin−peptide complex, where they are nonhelical. The doubling of the disordered region of the central helix (residues 78−81 at room temperature) when temperature is raised from 35 to 43 °C results in larger amplitude interdomain motion. Our analysis of the NMR relaxation ...
Learning community history

There are deeply rooted connections between learning and community in adult education. The historical examples and issues discussed here shed light on the interactions between individual learning, community, and modern society.
Ankle Fracture Classification Systems: A Case for Integration of the Lauge-Hansen and AO-Danis-Weber Schemes:

The two dominant classification systems for ankle fractures in use are the Lauge-Hansen and AO-Danis-Weber schemes. Each has certain advantages and disadvantages. Because of basic similarities, integration of these systems into one scheme involving three basic patterns with appropriate staging appears to be reasonable. This integration is based upon combining the pronation-abduction and pronation-external rotation injuries in Lauge-Hansen's scheme into one pronation-abduction-external rotation pattern. The resultant system would appear attractive in terms of combining relative simplicity with completeness.
Ruminal Fermentation and Nutrient Digestion by Dairy Cows Fed Varying Amounts of Soyhulls as a Replacement for Corn Grain

Abstract Five multiparous Holstein cows cannulated in the rumen and duodenum that averaged 63 d in milk were used in a 5×5 Latin square design with 14-d periods to evaluate the incremental substitution of soyhulls for corn in the diet. Diets contained 23% alfalfa silage, 23% corn silage, and 54% concentrate on a dry matter (DM) basis. Pelleted soyhulls replaced corn in the concentrate to supply 0, 10, 20, 30, or 40% of the dietary DM. The intakes of DM and organic matter were unaffected by treatments. Intakes of acid detergent fiber and neutral detergent fiber increased linearly, but the intake of nonstructural carbohydrates decreased linearly as soyhulls increased from 0 to 40% of dietary DM. The amount of acid detergent fiber and neutral detergent fiber digested was increased whereas the amount of nonstructural carbohydrate digested was decreased in the rumen, in the lower digestive tract, and in the total digestive tract as soyhulls replaced corn in the diet. Passage to the duodenum of nonammonia N, microbial N, nonammonia nonmicrobial N, total essential amino acids, total nonessential amino acids, and total amino acids were not affected by treatments. Yield of milk (29.5 kg/d) was not affected by treatments in this experiment. In a companion experiment, cows fed the 40% SH diet produced 1.2 kg/day per cow less ( P
Temporal Dependence of Ligand Dissociation and Rebinding at Planar Surfaces

In a previous work, conditions for which a ligand reversibly bound to a planar surface dissociates and then rebinds to the surface were theoretically examined (Lagerholm, B. C.; Thompson, N. L. Biophys. J. 1998, 74, 1215). The coupled differential equations that describe the reversible interaction of ligands in three-dimensional solution with sites on a planar surface were solved to find analytical solutions for the probabilities of finding a ligand on the surface or in solution, given initial placement on the surface. An expression was also found for the probability that a ligand rebinds to the surface at a given position and time after its release. In this work, the formalism is extended to calculate analytical, closed form expressions for the average number and rate of rebinding events that have occurred, on the average, at a given time after placing a ligand on the surface. These functions depend only on the intrinsic dissociation rate and a “rebinding parameter,” which depends on a group of constants...
Organolanthanide-catalyzed intramolecular hydroamination/cyclization of aminoalkynes

This contribution reports the efficient and regiospecific Cp‘2LnCH(SiMe3)2 (Ln = La, Nd, Sm, Lu; Cp‘ = η5-Me5C5)- and Me2SiCp‘‘2LnCH(SiMe3)2 (Ln = Nd, Sm; Cp‘‘ = η5-Me4C5)-catalyzed hydroamination/cyclization of aliphatic and aromatic aminoalkynes of the formula RC⋮C(CH2)nNH2 to yield the corresponding cyclic imines RCH2CN(CH2)n-1CH2, where R, n, Nt h-1 (°C) = Ph, 3, 77 (21 °C); Ph, 3, 2830 (60 °C); Me, 3, 96 (21 °C); CH2CMeCH2, 3, 20 (21 °C); H, 3, 580 (21 °C); Ph, 4, 4 (21 °C); Ph, 4, 328 (60 °C); Ph, 5, 0.11 (60 °C); and SiMe3, 3, >7600 (21 °C), and of aliphatic secondary amino-alkynes of the formula RC⋮C(CH2)3NHR1 to generate the corresponding cyclic enamines RCHCNR1(CH2)2CH2 where R, R1, Nt h-1 (°C) = SiMe3, CH2CHCH2, 56 (21 °C); H, CH2CHCH2, 27 (21 °C); SiMe3, CH2CH(CH2)3, 129 (21 °C); and H, CH2CH(CH2)3, 47 (21 °C). Kinetic and mechanistic evidence is presented arguing that the turnover-limiting step is an intramolecular alkyne insertion into the Ln−N bond followed by rapid protonolysis of the resu...
Algorithm 812: BPOLY: An object-oriented library of numerical algorithms for polynomials in Bernstein form

The design, implementation, and testing of a C++ software library for univriate polynomials in Bernstein form is described. By invoking the class environment and operator overloading, each polynomial in an expression is interpreted as an object compatible with the arithmetic operations and other common functions (subdivision, degree, elevation, differentiation and integration, compoistion, greatest common divisor, real-root solving, etc.) for polynomials in Bernstein form. The library allows compact and intuitive implementation of lengthy manipulation of Bernstein-form polynomials, which often arise in computer graphics and computer-aided design and manufacturing applications. A series of empirical tests indicates that the library functions are typically very accurate and reliable, even for polynomials of surprisingly high degree.
Evaluation of the tungsten oxide denuder tube technique as a method for the measurement of low concentrations of nitric acid in the troposphere

The applicability of the tungsten oxide denuder tube technique for the measurement of nitric acid in the rural troposphere was investigated. The technique is based on selective chemisorption of HNO3 from the gas stream, thermal desorption, conversion to NO, and analysis by NO−O3 chemiluminescence. Ammonia, which is also collected and desorbed as NH3 and NO, was separated from the HNO3-derived NO by linear temperature-programed thermal desorption. Possible interferences by NO2, HCN, PAN, and n-propyl nitrate (NPN) were tested and found to be significant under conditions found in the lower troposphere. Simultaneous ambient measurements of HNO3 were made with the tungsten oxide denuder tube and nylon filter methods at a rural site in the Colorado mountains (Niwot Ridge, CO). Nitric acid levels measured by the tungsten oxide denuder tube averaged a factor of 3 higher than levels measured by the nylon filter technique. Tests involving the placement of nylon materials in front of the tungsten oxide denuder tube show that there are species, as yet unidentified, present in the atmosphere that interfere with the measurement of HNO3 by the tungsten oxide technique.
Restraining the Further Education Market: Closing Pandora's Box.

There has been growing concern that the market‐dominated practice of colleges of further education in England has led to a situation where colleges compete aggressively to the detriment of current and potential students. A recent report suggested that autonomous colleges could not achieve the widening of participation and equity required of vocational education and training, and recommended regional planning and partnership to balance the negative effects of a market‐driven approach. This article reports on interviews with college principals and on the analysis of a sample of college strategic plans, and concludes that although partnership may be welcomed by some, colleges are unlikely to co‐operate unless the system retains a sufficient degree of autonomy for individual institutions and does not damage the interests of individual colleges by a redistribution of resources. It also argues that the suggested planning framework of the National Training and Education Targets and labour market information may ...
Probing electronic density of states and magnetic interactions at the rare-earth site in ErBa2Cu3O7.

By exploiting the $4f$-shell properties of Er in the high-${T}_{c}$ superconductor Er${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$, we find by inelastic magnetic neutron scattering that the electrostatic field around the rare-earth site is anomalously large. Above ${T}_{c}$ there exists considerable magnetic interaction between the conduction electrons and the rare-earth's $4f$ shell: $N({E}_{F}){J}_{\mathrm{ex}}=0.025$. This interaction is lost in the superconducting state. The ground-state magnetic moment of Er in the host lattice is ${\ensuremath{\mu}}_{\mathrm{eff}}=5.3{\ensuremath{\mu}}_{B}$.
Two fatal complications after parallel tracheal-esophageal stenting.

Two patients with malignant obstructions of both the trachea and esophagus underwent parallel stent placement with Gianturco-Roesch Z (GRZ) stents for palliation of symptoms. Fatal hemorrhage occurred in both patients 2 and 3 weeks after stent placement respectively. An autopsy performed on one of these patients demonstrated esophageal tissue necrosis and erosion with perforation of both the tracheal and esophageal walls at sites where the stent struts were in direct opposition, leading to bleeding from the esophageal venous plexus. GRZ stents have been successful in the treatment of both solitary tracheal and esophageal stenoses. However, parallel tracheal-esophageal stenting with GRZ stents places patients at high risk for complications due to the high radial force exerted by this particular stent and the minimal amount of intervening tissue between the two structures.
Hierarchical Silica Nanostructures Inspired by Diatom Algae Yield Superior Deformability, Toughness, and Strength

A universal design paradigm in biology is the use of hierarchies, which is evident in the structure of proteins, cells, tissues, and organisms, as well as outside the material realm in the design of signaling networks in complex organs such as the brain. A fascinating example of a biological structure is that of diatoms, a microscopic mineralized algae that is mainly composed of amorphous silica, which features a hierarchical structure that ranges from the nano- to the macroscale. Here, we use the porous structure found at submicron length scales in diatom algae as a basis to study a bioinspired nanoporous material implemented in crystalline silica. We consider the mechanical performance of two nanoscale levels of hierarchy, studying an array of thin-walled foil silica structures and a hierarchical arrangement of foil elements into a porous silica mesh structure. By comparing their elastic, plastic, and failure mechanisms under tensile deformation, we elucidate the impact of hierarchies and the wall width of constituting silica foils on the mechanical properties, by carrying out a series of large-scale molecular dynamics (MD) simulations with the first principles based reactive force field ReaxFF. We find that by controlling the wall width and by increasing the level of hierarchy of the nanostructure from a foil to a mesh, it is possible to significantly enhance the mechanical response of the material, creating a highly deformable, strong, and extremely tough material that can be stretched in excess of 100 pct strain, in stark contrast to the characteristic brittle performance of bulk silica. We find that concurrent mechanisms of shearing and crack arrest lead to an enhanced toughness and are enabled through the hierarchical assembly of foil elements into a mesh structure, which could not be achieved in foil structures alone. Our results demonstrate that including higher levels of hierarchy are beneficial in improving the mechanical properties and deformability of intrinsically brittle materials. The findings reported here provide insight into general material design approaches that may enable us to transform a brittle material such as silicon or silica into a ductile, yet strong and tough material, solely through alterations of its structural arrangement at the nanoscale.
Monte Carlo Simulations Investigating the Threading of Cyclic Poly(ethylene oxide) by Linear Chains in the Melt

A coarse-grained Monte Carlo algorithm on a modified diamond lattice has been used to study the dependence of threading of cyclic poly(ethylene oxide) molecules by linear poly(ethylene oxide) chains in the melt on the mass fraction (Xc) and the size (Nc) of the cyclics. Both short-range interactions based on the rotational isomeric state model and long-range interactions from a discretized form of the Lennard-Jones (LJ) potential energy function are included. LJ parameters σ and e/kB of 3.76 A and 154 K, respectively, are estimated for the coarse-grained model. In addition, a method is presented for detecting threading of cyclics that have instantaneous conformations that significantly differ from a circle. The percentage of cyclic molecules threaded can be described as a linear function of Xc. When the cyclics consist of 10 or less coarse-grained monomer units, the percentage of cyclic molecules threaded falls to less than 1%, which suggests that spontaneous threading of cyclics smaller than 30-crown-10 ...
The effect of fluoxetine on the pharmacokinetics and psychomotor responses of diazepam

To determine the effect of fluoxetine on diazepam's pharmacokinetic and psychomotor responses, single oral doses of 10 mg diazepam were administered to six normal subjects on three occasions, either alone or in combination with 60 mg fluoxetine. Diazepam was given alone, after a single dose of fluoxetine, and after eight daily doses of fluoxetine. Psychometric data showed that fluoxetine had no significant effect on the psychomotor responses to diazepam. However, the pharmacokinetic data indicated a change in diazepam disposition after fluoxetine administration. Diazepam AUC was larger, the half-life was longer, and the plasma clearance was lower after fluoxetine administration, suggesting that fluoxetine inhibited the metabolism of diazepam. The reduced formation of an active metabolite, N-desmethyldiazepam, also suggested that fluoxetine inhibited diazepam's metabolism. The clinical implications of this pharmacokinetic drug-drug interaction are minor because psychomotor responses were unaffected and offsetting changes in the kinetics of diazepam and its metabolite occurred. Dosage modification of either fluoxetine or diazepam is unlikely to be necessary.
Self-organization in housing choices of persons with disabilities

Complexity theory provides a promising exploratory framework for demonstrating quantifiable improvements of disability interventions. This paper introduces concepts of complex systems theory and applies one particular underlying concept, self-organizing, to a program providing housing and other support services to persons with disabilities. Using this specific component of complexity theory provides a beginning point to explore how consumers and their allies made choices on where their homes would be located.
Bäcklund transformation of a “variable viscosity” burgers equation

Abstract The paper obtains a Hopf-Cole type Backlund transformation for Burgers equation with variable viscosity; the resulting equation is no longer linear. However the linear part belongs to the generalized Focker-Planck type equation, for which exact solutions can be constructed. For slowly varying viscosity, this allows the method of perturbation to be used to improve the solution.