cssi/SciSciGPT-SciSciNet huggingface dataset:
Natural lipid extracts and biomembrane-mimicking lipid compositions are disposed to form nonlamellar phases, and they release DNA from lipoplexes most efficiently

A viewpoint now emerging is that a critical factor in lipid-mediated transfection (lipofection) is the structural evolution of lipoplexes upon interacting and mixing with cellular lipids. Here we report our finding that lipid mixtures mimicking biomembrane lipid compositions are superior to pure anionic liposomes in their ability to release DNA from lipoplexes (cationic lipid/DNA complexes), even though they have a much lower negative charge density (and thus lower capacity to neutralize the positive charge of the lipoplex lipids). Flow fluorometry revealed that the portion of DNA released after a 30-min incubation of the cationic O-ethylphosphatidylcholine lipoplexes with the anionic phosphatidylserine or phosphatidylglycerol was 19% and 37%, respectively, whereas a mixture mimicking biomembranes (MM: phosphatidylcholine/phosphatidylethanolamine/phosphatidylserine /cholesterol 45:20:20:15 w/w) and polar lipid extract from bovine liver released 62% and 74%, respectively, of the DNA content. A possible reason for this superior power in releasing DNA by the natural lipid mixtures was suggested by structural experiments: while pure anionic lipids typically form lamellae, the natural lipid mixtures exhibited a surprising predilection to form nonlamellar phases. Thus, the MM mixture arranged into lamellar arrays at physiological temperature, but began to convert to the hexagonal phase at a slightly higher temperature, {approx} 40-45 C. Amore » propensity to form nonlamellar phases (hexagonal, cubic, micellar) at close to physiological temperatures was also found with the lipid extracts from natural tissues (from bovine liver, brain, and heart). This result reveals that electrostatic interactions are only one of the factors involved in lipid-mediated DNA delivery. The tendency of lipid bilayers to form nonlamellar phases has been described in terms of bilayer 'frustration' which imposes a nonzero intrinsic curvature of the two opposing monolayers. Because the stored curvature elastic energy in a 'frustrated' bilayer seems to be comparable to the binding energy between cationic lipid and DNA, the balance between these two energies could play a significant role in the lipoplex-membrane interactions and DNA release energetics.« less
Mechanisms of cholinesterase inhibition in senile dementia of the alzheimer type: Clinical, pharmacological, and therapeutic aspects

Senile dementia of the Alzheimer type (SDAT) is a degenerative disease of the brain that affects up to 20% or more of individuals who live beyond 80 years of age. A deficiency of cholinergic function is expected to play a major role in the development of SDAT psychopathology. Possible existence of an underactive cholinergic system has led to clinical trials of cholinomimetic drugs to attempt to reverse the deficit in SDAT. Some improvement in memory function has followed the administration of cholinesterase (ChE) inhibitors, but in general the affected individuals have not been returned to normal or mildy impaired mental functions or activities of daily living functioning. This paper is a critical review of results of acute and chronic trials performed with ChE inhibitors in experimental animals and humans. We also review and discuss mechanisms of decvelopment of pharmacological behavioral tolerance to ChE inhibitors. Behavioral changes following ChE inhibition appear to coincide with predicted peak levels of acetulcholine (ACh) concentration in the brain. Yet we find an inconsistent relationship among the degree of ChE inhibition, changes in brain acetylcholine concentrations, and behavioral changes, both therapeutic and adverse effects, following administration of ChE inhibitors. ChE inhibition is associated with distressing adverse effects. The therapeutic effects of increased ACh levels in the brain may be masked by these side effects. We suggest that an adequate test of the efficacy of ChE inhibition may await the use of new and improved ChE inhibitors that produce significantly fewer side effects and greater therapeutic effects than drugs presently being tested for efficacy in the treatment of SDAT patients.
Estimating Flow Properties of Porous Media With a Model For Dynamic Diffusion

We present an approach for estimating effective compressibility and permeability from Differential acoustic resonance spectroscopy (DARS) laboratory measurements. The effective compressibility of fluid-saturated porous medium, located in a harmonic pressure field, is a function of the loading frequency and the fluid in the pore space, as well as the permeability and porosity of the medium. The process is describable by a diffusion process that relates effective compressibility and permeability. DARS is used to measure the effective compressibility. Then the diffusion model is used to estimate the permeability. This method is tested with DARS lab data.
Eying the Thought Awry: The Anamorphosis of John Donne's Poetry

AbstractBy applying the concept of anamorphosis to the logical structures of John Donne's poetry, this essay extends the concept of anamorphosis from the visual peculiarity of an obscured image whose revelation requires finding an eccentric point of view to the epistemological process experienced by the viewer. An encounter with anamorphosis possesses its own strict logic; likewise, anamorphic constructions engender a rhetoric specific to their needs. Riehl argues that literary criticism should extend the study of anamorphosis in early modern literary texts in a new direction: both visual and verbal anamorphic models are engendered by the habits of thought, patterns of thinking that, by the seventeenth century, pervade various media and modes of representation. Even in the absence of explicit references to perspective, seeing, or painting, a text may nevertheless operate according to the rules of anamorphic logic and rhetoric. Aiming the anamorphic lens at Donne, this essay unravels anew the complex argum...
Genetic and environmental factors that affect gestation length in dairy cattle.

Abstract Genetic and environmental factors that might affect gestation length (GL) were investigated. Data included information from >11million parturitions from 1999 through 2006 for 7 US dairy breeds. Effects examined were year, herd-year, month, and age within parity of conception; parturition code (sex and multiple-birth status); lactation length and standardized milk yield of cow; service sire; cow sire; and cow. All effects were fixed except for service sire, cow sire, and cow. Mean GL for heifers and cows, respectively, were 277.8 and 279.4 d for Holsteins, 278.4 and 280.0 d for Jerseys, 279.3 and 281.1 d for Milking Shorthorns, 281.6 and 281.7 d for Ayrshires, 284.8 and 285.7 d for Guernseys, and 287.2 and 287.5 d for Brown Swiss. Estimated standard deviations of GL were greatly affected by data restrictions but generally were approximately 5 to 6 d. Year effects on GL were extremely small, but month effects were moderate. For Holstein cows, GL was 2.0 d shorter for October conceptions than for January and February conceptions; 4.7 and 5.6 d shorter for multiple births of the same sex than for single-birth females and males, respectively; 0.8 d longer for lactations of ≤250 d than for lactations of ≥501 d; and 0.6 d shorter for standardized yield of ≤8,000kg than for yield of ≥14,001kg. Estimates for GL heritability from parities 2 to 5 were 33 to 36% for service sire and 7 to 12% for cow sire; corresponding estimates from parity 1 were 46 to 47% and 10 to 12%. Estimates of genetic correlations between effects of service sire and cow sire on GL were 0.70 to 0.85 for Brown Swiss, Holsteins, and Jerseys, which indicates that those traits likely are controlled by many of the same genes and can be used to evaluate each other. More accurate prediction of calving dates can help dairy producers to meet management requirements of pregnant animals and to administer better health care during high-risk phases of animals' lives. However, intentional selection for either shorter or longer GL is not recommended without consideration of its possible effect on other dependent traits (e.g., calving ease and stillbirth).
Student Teachers' Use of Instructional Choice in Physical Education.

Abstract Guided by self-determination theory and research on teacher beliefs, we examined student teachers' (STs) use of instructional choices in teaching physical education classes. Participants included 131 STs (52 men and 79 women) from a major university in the United States. STs completed questionnaires assessing three types of instructional choices (cognitive, organizational, and procedural) they provided and their rationale for providing their students with choices. The STs reported they gave students cognitive, organizational, and procedural choices. They firmly believed instructional choice promotes students' motivation, autonomy, and engagement in physical education. They also believed teachers should consider factors such as student characteristics and the beneficial effects when implementing choice in their classes.
Probabilistic Torsional Vibration Analysis of a Marine Diesel Engine Shafting System: The Level Crossing Problem

In this analysis, the shafting shear stress is found to be a Gaussian, harmonizable cyclostationary process with a harmonic series representation consisting of two complex conjugate components. In this paper, the level crossing problem for this stress process is studied
Structure and Property Relationships in Mixed-Conducting Sr4(Fe1−xCox)6O13±δMaterials

Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid-oxide fuel cells, batteries, sensors, and oxygen-permeable membranes. The Sr4(Fe1−xCox)6O13±δsystem combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry or to partially oxidize methane to produce synthesis gas (syngas, CO+H2). Samples of Sr4(Fe1−xCox)6O13±δ(wherex=0, 0.1, 0.2, 0.333, and 0.467) were prepared by a solid-state reaction method in atmospheres with various oxygen partial pressure (pO2) and were characterized by powder X-ray diffraction, scanning electron microscopy, and electrical conductivity testing. The proportion of phase components in the samples is dependent on both cobalt content andpO2. The total conductivity increases with both temperature and cobalt substitution in the material. Current–voltage characteristics determined in a gas-tight cell indicate that a bulk effect, rather than a surface exchange effect, is the main limiting factor for oxygen permeation through membranes made of Sr4Fe4Co2O13±δ(x=0.333 sample). Oxygen permeability measurements at various temperatures showed that, as expected, permeability increases with increasing temperature. At 900°C, an oxygen permeation flux of 2.5 scc·cm−2·min−1was obtained from an Sr4Fe4Co2O13±δdisk membrane that was 2.9 mm thick.
Neuronal and non-neuronal properties of neuroblastoma cells

Abstract Three different mouse neuroblastoma cell lines (S20Y, N2CL10, N115) were examined for acetylcholinesterase activity, ganglioside composition, cell processes, and affinity for protargol silver (i.e., argyrophilia). Assays were made on cloned cells, corresponding tumors which developed after subcutaneous injection of A J strain male mice with 2 × 10 6 cells, and primary and secondary cultures. Acetylcholinesterase activity was present in all cells assayed, with maximal activity noted in cloned cells. Ganglioside patterns of neuroblastoma cells differed from those of neural cells, but remained qualitatively unchanged for a given cell line grown in vivo or in vitro. Some cells were stained with protargol silver in primary cultures, but few cells in cloned or secondary cultures, or those in in vivo tissues, were impregnated with protargol silver. These findings show that while neuroblastoma cell lines maintain some neuronal characteristics (i.e., high acetylcholinesterase levels, cell processes), they do not express other accepted neuronal properties (i.e., ganglioside patterns, argyrophilia), and suggest that direct analogies between normal neurons and “differentiated” neuroblastoma cells should be made with caution.
Evidence that cholesteryl ester hydrolase and triglyceride lipase are different enzymes in rat liver

Studies on intracellular cholesteryl ester hydrolase (CEH) and triglyceride lipase (TGL) from rat adipose tissue and adrenal cortex have suggested that a single protein is responsible for both activities. To determine whether one hepatic protein catalyzes both reactions, we studied several properties of CEH and TGL in rat liver. During liver perfusion with heparin, perfusate peaks of TGL and CEH did not consistently coincide, and TGL activity was considerably higher and less heat-stable than that of CEH. Significant TGL, but not CEH, activity was released during incubation of isolated hepatocytes. Although microsomes isolated from hepatocytes contained both activities, the specific activities of CEH and TGL in cytosol from hepatocytes were 95% and 3%, respectively, of those found in cytosol from whole liver. Preincubation of liver cytosol with 5 mM Mg2+ decreased CEH, but not TGL, activity. Intracellular CEH and TGL activities were completely separated by prep-disc gel electrophoresis. Finally, both cytosolic and microsomal TGL, but not CEH, activities were inhibited by antiserum against rat hepatic TGL. We conclude that extracellular TGL does not have CEH activity and intracellular CEH differs from TGL.
An Objective Study of the Effects of Expectation on Competitive Performance

(1972). An Objective Study of the Effects of Expectation on Competitive Performance. The Journal of Psychology: Vol. 81, No. 1, pp. 69-72.
DEPURATION AND PUBLIC HEALTH

This paper reviews briefly the viral, bacterial, and toxic diseases borne by shellfish that are transmissible to man. Methods available to cleanse or depurate contaminated bivalves are also presented. Each method is evaluated with regard to 1) present and past use, 2) economic cost benefits, and 3) ability to prevent disease transmission.
The Financial and Operating Performance of Privatized Firms during the 1990s

This study compares the pre- and postprivatization financial and operating performance of 85 companies from 28 industrialized countries that were privatized through public share offerings for the period from 1990 through 1996. We document significant increases in profitability, output, operating efficiency, and dividend payments-and significant decreases in leverage ratios-for our full sample of firms after privatization, and for most subsamples examined. Capital expenditures increase significantly in absolute terms, but not relative to sales. Employment declines, but insignificantly. Combined with results from two previous, directly comparable studies, these findings strongly suggest that privatization yields significant performance improvements. DURING THE PAST TWO DECADES, the privatization of state-owned enterprises has moved from being a radical, almost desperate, policy initiative of the Thatcher government in Britain to being an accepted economic policy for governments of all ideological stripes. According to Gibbon (1998), $860 billion has been raised by governments worldwide through privatizations, with the bulk of this total coming since 1987, and at least one commentator (Roche (1996)) predicts that no less than $6 trillion will be raised through privatizations over the next two decades. In 1997 alone, sales of public enterprises totaled a record $161 billion worldwide, with more than $110 billion of the total coming during the second half of the year, and 1998's total of almost $140 billion indicates that the pace shows no sign of slackening as we approach a new millennium.
On the lowest T = 32 state in 41Sc

Abstract Precise energies of β+-delayed protons emitted from the lowest T = 3 2 analoque states in several T z = − 1 2 nuclei have been measured. The lowest T = 3 2 level in 41Sc was found to lie at Ex = 5935 ± 8 keV, in substantial disagreement with the previously accepted value.
Is stress concentration relevant for nanocrystalline metals

Classical fracture mechanics as well as modern strain gradient plasticity theories assert the existence of stress concentration (or strain gradient) ahead of a notch tip, albeit somewhat relaxed in...
Organization of the human superior olivary complex.

The distinctive morphology of the human superior olivary complex reflects its primate origins, but functional evidence suggests that it plays a role in auditory spatial mapping which is similar to olivary function in other mammalian species. It seems likely that the well-developed human medial olivary nucleus is the basis for extraction of interaural time and phase differences. The much smaller human lateral olivary nucleus probably functions in analysis of interaural differences in frequency and intensity, but the absence of a human nucleus of the trapezoid body implies some difference in the mechanisms of this function. A window on human olivary function is provided by the evoked auditory brainstem response (ABR), including its binaural interaction component (BIC). Anatomical, electrophysiological, and histopathological studies suggest that ABR waves IV and V are generated by axonal pathways at the level of the superior olivary complex. Periolivary cell groups are prominent in the human olivary complex. The cell groups located medial, lateral, and dorsal are similar to periolivary nuclei of other mammals, but the periolivary nucleus at the rostral pole of the human olivary complex is very large by mammalian standards. Within the periolivary system, immunostaining for neurotransmitter-related substances allows us to identify populations of medial and lateral olivocochlear neurons. The human olivocochlear system is unique among mammals in the relatively small size of its lateral efferent component. Some consideration is given to the idea that the integration provided by periolivary cell groups, particularly modulation of the periphery by the olivocochlear system, is an extension of the spatial mapping function of the main olivary nuclei. Microsc. Res. Tech. 51:403–412, 2000. © 2000 Wiley-Liss, Inc.
Applications of Optical Parametric Process

Recent progress in parametric waveband conversion for grouped-wavelength path allocation and features of the phase-sensitive parametric amplifier are described after briefly introducing the application of the optical parametric process to optical communication.
Synthesis of binary mixed homopolymer brushes by combining atom transfer radical polymerization and nitroxide-mediated radical polymerization

Abstract This communication describes a novel strategy to synthesize binary mixed homopolymer brushes from mixed self-assembled monolayers (SAMs) on silica substrates by combining atom transfer radical polymerization (ATRP) and nitroxide-mediated radical polymerization (NMRP). Mixed SAMs terminated by ATRP and NMRP initiators were prepared by coadsorption of two corresponding organotrichlorosilanes from toluene solutions. Mixed poly(methyl methacrylate) (PMMA)/polystyrene (PS) brushes were synthesized by ATRP of MMA at 80 °C followed by NMRP of styrene at 115 °C. Corresponding ‘free’ initiators were added into the solutions to control the polymerizations. We have found that the brush thickness increases with molecular weight in a nearly linear fashion. For a series of binary brushes consisting of PMMA of molecular weight of 26,200 and PS of various molecular weights, we have observed a transition in water contact angles with increasing PS molecular weight after CH2Cl2 treatment. Moreover, binary mixed polymer brushes with comparable molecular weights for two grafted polymers undergo reorganization in response to environmental changes, exhibiting different wettabilities.
Design and Characterization of Integrated Submillimeter-Wave Quasi-Vertical Schottky Diodes

This work reports on a new approach to realizing vertically oriented Schottky diodes, with ohmic contact formed directly below the anode, that can be readily integrated into planar millimeter and submillimeter-wave circuits. The diode structure is based on backside processing and bonding of the diode epitaxy to a host, high-resistivity silicon substrate that supports both the vertical diode and its associated circuitry. A set of prototype diodes of different anode diameters are fabricated for characterization at both dc and (for the first time) submillimeter-wave frequencies (325–750 GHz) using micromachined on-wafer probes. Device equivalent circuit parameters extracted from these measurements are in good agreement with those expected from fundamental Schottky barrier diode theory and indicate the vertically oriented diodes yield series resistance values that are comparable to or lower than planar-oriented diodes of similar dimensions.
A Note on Determining Amylopectin A-to-B Chain Ratios†

The A-to-B chain ratio is one method being used to characterize amylopectin. We found it difficult to obtain reproducable A-to-B chain ratios. The major problem appears to be related to the series of mathematical steps involved in the calculations rather than variations in the primary data. Small changes in Nelson reducing power gave relatively large differences in A-to-B ratios. Determination of the standard deviation in determining reducing power at various glucose concentrations followed by calculation of theoretical A-to-B chain ratios and their corresponding 95% confidence internals showed that reducing power must be determined with extreme precision if the A-to-B ratios are to be meaningful. Bemerkung zur Bestimmung des AB-Kettenverhaltnisses von Amylopektin. Die Bestimmung des A/B-Kettenverhaltnisses ist eine Methode, die zur Charakterisierung des Amylopektins herangezogen wird. Wir fanden, das es schwierig ist, reproduzierbare A/B-Kettenverhaltnisse zu erhalten. Das wesentliche Problem dabei scheint eher mit der Serie von mathematischen Schritten bei den Berechnungen als mit Schwankungen der ersten Daten zusammenzuhangen. Geringe Anderungen des Reduktionswertes nach Nelson ergaben relativ grose Unterschiede hinsichtlich der A/B-Verhaltnisse. Die Ermittlung der Standardabweichung bei der Bestimmung des Reduktionswertes bei verschiedenen Glucose-Konzentrationen gefolgt von der Berechnung der theoretischen A/B-Kettenverhaltnisse und ihrer korrespondierenden 95%igen Zuverlassigkeit zeigte, das die Bestimmung des Reduktionswertes mit groster Genauigkeit erfolgen mus, wenn die A/B-Verhaltnisse aussagekraftig sein sollen.
Astrocytic responses to the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in cat and mouse brain.

Glial fibrillary acidic protein immunohistochemistry was used as a selective marker for regional reactive gliosis in the striatum and ventral mesencephalon in cats and mice exposed to the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Thirty mice (C-57 black strain) were injected with 30 mg/kg intraperitoneally (IP) MPTP.HCl for seven days. Five adult cats were injected with 10 mg/kg IP MPTP.HCl for seven days. Animals were killed five to seven days after the last MPTP injection. Reactive gliosis was observed throughout the mouse striatum but not in the substantia nigra. In contrast, reactive gliosis was topographically represented in the cat caudate nucleus with a dorsal-ventral and medial-lateral gradient evident. Gliosis was also observed in the putamen and the substantia nigra, pars compacta. Tyrosine hydroxylase immunocytochemistry revealed a loss of dopamine in the mouse striatum but no loss of substantia nigra neurons. Nigral neurons were destroyed in the cat. These results suggest that MPTP may destroy nigrostriatal dopamine cell bodies and terminals in the cat while destruction in the mouse is at least initially confined to striatal terminals.
The role of sequential processing models in marketing research

Abstract Mathematical models, derived from underlying assumptions of the threshold concept and the utility maximization principle, continue to grow. Current applied applications of multiple-choice problems, have generally used simultaneous compensatory models. The models of this class are the multinomial logit, probit and the generalized extreme value. Within choice modeling, logit is the most commonly used, generally in a linear functional form. However, these simultaneous compensatory evaluation models do not appear to reflect the cognitive process by which individuals make their choice. Work in such areas as psychology, marketing, information theory and artificial intelligence posit that individuals often use a sequential decision process. This process assumes that individuals process through the ranking of attributes (ranked according to order of importance), eliminating alternatives in a sequential manner. The focus of this paper centers around the discussion of sequential processing models. Within this framework, mathematical models that generate and estimate threshold tolerances and provide choice probabilities are presented. Furthermore, the use of choice models as a function of individual differences, and various factors that increase the credibility of the role of sequential processing models are discussed.
Prospects for studying chemisorption kinetics using current fluctuations

Abstract The rates of surface catalytic reactions are, in principle, reflected in the frequency spectrum of adsorbate density fluctuations. These fluctuations change the incremental current (i.e., increment over the average current corresponding to the average surface coverage) noise due to electron transfer between the adsorbate and the substrate and to the scattering of the substrate electrons from the adsorbates. In an adiabatic limit, the incremental current noise is proportional to the conductivity modulation induced by the adsorbate density fluctuations and to the square of the applied voltage. Thus, the noise in the substrate current provides information about the surface reaction kinetics. This reaction may proceed either in equilibrium or in nonequilibrium. The adsorbate density spectrum has been calculated both in and out of equilibrium for two specific reactions. No major difference is found between the in and out of equilibrium cases. When these involve two-step processes, the adsorbate density correlation function is the sum of two decaying exponentials and the spectrum is the sum of two Lorentzians.
Perylene excimer fluorescence in cyclohexane

Abstract The blue monomer fluorescence of perylene in cyclohexane is replaced by an orange excimer fluorescence emission upon freezing the solution with increasing pressure. The temperature dependence of the excimer decay is characterized by a radiative lifetime of 80 nsec and an activation energy of 670 cm −1 .
Transforming activity in single-stranded DNA from Bacillus subtilis

Abstract Low concentrations of EDTA, which inhibit transformation of Bacillus subtilis by native DNA ( Young & Spizizen, 1963 ), enhance transformation by denatured DNA. In the absence of EDTA, transforming activity in denatured DNA is due to cross-linked molecules which resist denaturation and have native-like buoyant density ( Rownd, 1963 ; Alberts, 1965 ; Alberts & Doty, 1968) . Evidence is presented here that EDTA inhibits transformation by these native-like cross-linked species in denatured DNA and facilitates transformation by a new DNA species having buoyant density and sedimentation properties of denatured DNA. The EDTA-active species are shown to have separated from their original complements and not to have re-associated with other DNA strands.
Genetic polymorphism of the mouse major histocompatibility complex-associated proteasome subunit Lmp7.

Major histocompatibility complex (MHC) class I molecules mainly resent antigenic peptides derived from cytosolic and nucleic proteins. The discovery of four new genes, namely Tap1, Tap2, Lmp2, and Lmp7, in the human, mouse, and rat MHC class II regions has shed light on the mechanisms repsonsible for the production and transport of these antigenic peptides for presentation by MHC class I molecules. Little is known about the polymorphism of LMP2 and LMP7 molecules. We have shown previously that three amino acid variants of LMP2 are distributed among 12 inbred mouse strains. Here, we have extended this analysis by sequencing the Lmp7 gene in different strains of mice. Altogether, our studies provide a clear insight into the distribution of LMP2 and LMP7 alleles among mouse haplotypes. 20 refs., 1 fig., 3 tabs.
Simplified Model for Analysis and Optimization of Skyscrapers with Outrigger and Belt Trusses

AbstractA simplified skyscraper model (SSM) based on dominant degrees of freedom and superelements was developed and implemented in a spreadsheet for use in preliminary design of skyscrapers with outrigger and belt trusses. The SSM was used to analyze and optimize the linear and nonlinear response to gravity, wind, and seismic loading of four configurations of an example 100-story skyscraper. Results from the SSM were compared with those from a detailed finite element model (DFEM), and the difference was less than 1% for displacement and 6% for maximum stress. The SSM properly predicted the deflected shape of the core including curvature reversals typical of skyscrapers with outrigger and belt trusses. The speed of execution, data preparation, data extraction, and optimization were found to be much faster with the SSM than with the DFEM.
Pulmonary Rehabilitation Increases Gait Speed in Patients With Chronic Lung Diseases

Introduction:Gait speed provides an integrated index of physical performance; changes in gait speed could reflect deterioration in the underlying medical disorder or a response to medical/surgical ...
Clinical and Parental Assessment of Sleep in Children with Attention-Deficit/Hyperactivity Disorder Referred to a Pediatric Sleep Medicine Center

Frequently reported sleep problems in children with attention deficit-hyperactivity disorder (ADHD) referred to a pediatric sleep medicine center were assessed and compared with objective sleep assessments. A retrospective review of 97 children with ADHD (mean age of 8.3 ± 3.0 years) was conducted. Polysomnography in 69 children revealed periodic limb movement disorder (PLMD) in 36% and sleep-disordered breathing in 7%, while actigraphy uncovered substantial variability in sleep schedules of 16 patients. Although parental subjective sleep complaints were verified by objective sleep assessments in a small proportion of cases, PLMD and night-to-night variability in sleep patterns were common.
The role of motivational and incentive levels in the determination of successive discrimination reversal (SDR) performance of Chukar partridge

The performances of Chukar partridge on a spatial successive discrimination reversal task was studied at two levels of drive (D) and at two levels of incentive (K). Variation in both D and K led to variation in errors across reversal problems. High D tended to increase errors, while high K yielded a decrement in errors.
Opening of the burke-schumann flame tip and the effects of curvature on diffusion flame extinction

Effects of flame curvature on diffusion flame extinction have been studied via the model problem of the opening of the Burke-Schumann flame tip. Asymptotic analysis of the flame structure in the tip region shows that increasing the extent of the flame curvature facilitates near-complete reaction and theraby enhances the burning intensity. Consequently, for unity Lewis number flames, increases in the flow velocity tend to inhibit tip opening because of the corresponding decrease in the radius of the flame tip. Expermental results using nearunity Lewis number acetylene/air flames agree with the predicted flame geometry and its inability to achieve tip opening. Tip opening, however, can be achieved by using a sub-unity Lewis number fuel stream of hydrogen and carbon dioxide, which causes a general lowering of flame temperature in the entire flame tip region. Further experiments then confirm the theoretical result that negative stretch, in the form of compressive flame curvature, promotes burning and thereby retards extinction.
Bacterial Contamination of Blood DNA Samples is Associated with Donor's Health Condition.

Bacterial contamination often occurs in human blood DNA samples, possibly due to bacteremia or an inappropriate procedure during sample preparation. This study aimed at analyzing the clinical significance of bacterial DNA contamination in human blood DNA samples and to assess its influence on experimental data. DNA samples (N = 1359) were randomly selected from population-based cohort samples to determine bacterial DNA contamination by polymerase chain reaction and direct DNA sequencing. Bacterial DNA contaminated samples (N = 150) were then assessed for experimental quality of single nucleotide polymorphism (SNP) chip data, compared with uncontaminated DNA samples (N = 1209). DNA sequencing data showed that a major source of bacterial contaminants was derived from Alcaligenes species. The occurrence of bacterial DNA contaminations was significantly associated with some clinical variables including a postprandial glucose level at 60 min, % body fat, and waist-to-hip ratio. It was also found that there was...
Absence of tight junctions in endothelium of marrow sinuses: possible significance for marrow cell egress.

Summary. The nature of contact between endothelial cells in rat marrow sinuses was studied. Colloidal lanthanum permeated freely into the interendothelial space. Moreover, using freeze-fracture technique, we failed to show junctional structures where these endothelial cells came into contact. With thin sectioning electron microscopy, we observed occasional submembranous densities but the interendothelial distance measured 20 nm and no membrane fusion was seen. Absence of tight junctions between endothelial cells of marrow sinuses may serve a function in marrow cell egress by permitting these cells to slide over each other, thereby changing the luminal size. Within the fixed volume of marrow, an increase in luminal size results in displacement of haemopoietic cells into the lumen.
High-index dielectric substrates with nearly constant reflectance for incident unpolarized or circularly polarized light over a wide range of incidence angles

Dielectric substrates with refractive indices in the range n1 ≤ n ≤ n2, n1=2+3=3.7321 and n2=(2+1)+2(2+1)=4.6116, exhibit nearly constant reflectance for incident unpolarized or circularly polarized light Ru(ϕ) over a wide range of incidence angle ϕ. For n1=2+3, Ru(ϕ) increases monotonically from Ru(0)=R0=0.3333¯ at normal incidence by only 0.06% at ϕ = 45° and 1% at ϕ = 60°. For n2 = 4.6116, Ru(ϕB)=R0=2-1=0.4142 at the Brewster angle ϕB = 77.77° and the normalized reflectance shift |(Ru − R0)/R0| is <4.64% over the extended range 0 ≤ ϕ ≤ 80°. Apart from a small imaginary part (k << n), refractive indices of semiconductor substrates (e.g. Ge and GaAs) fall in the range n1 ≤ n ≤ n2 and hence exhibit nearly constant reflectance for incident unpolarized light over a wide range of incidence angles at IR and visible wavelengths.
Piezoelectric measurements with atomic force microscopy

An atomic force microscope (AFM) is used to measure the magnitude of the effective longitudinal piezoelectric constant (d33) of thin films. Measurements are performed with a conducting diamond AFM tip in contact with a top electrode. The interaction between the tip and electric field present is a potentially large source of error that is eliminated through the use of this configuration and the conducting diamond tips. Measurements yielded reasonable piezoelectric constants of X-cut single-crystal quartz, thin film ZnO, and nonpiezoelectric SiO2 thin films.
Carbonic anhydrase activity in isolated osteoclasts.

Abstract Osteoclasts were isolated from the long bones of chicks by a nylon mesh filtering system. The cell purity, in terms of area of the slide occupied, was on the average 77.5% osteoclasts, 22% aggregated osteoblasts and matrix debris, and 1.5% individual blood and marrow cells. Viability, as measured by cytochalasin-blockable phagocytosis, of up to 99% was obtained. Electron microscopic examination revealed good retention of ultrastructural features. The presence of carbonic anhydrase and acid phosphatase in osteoclasts was verified by selective staining methods; the aggregates were positive for alkaline phosphatase. Carbonic anhydrase activity was 0.89 ± 0.13 × 10 −4 micro Wilbur-Anderson units per osteoclast, and red blood cells had 0.12 ± 0.03 × 10 −4 units/cell. Neither calcitonin nor parathyroid hormone influenced the activity of carbonic anhydrase. A review of other hormonal effects on carbonic anhydrase is provided.
Role of Defects in the Adsorption of Aliphatic Alcohols on the TiO2(110) Surface

The role of defects in the adsorption of aliphatic alcohols on TiO2(110) was studied by means of TPRS and XPS. Point defects (oxygen vacancies) were created by electron bombardment in order to minimize the structural damage inflicted to the surface. Ethanol, n-propanol, and 2-propanol adsorbed dissociatively on the TiO2(110) surfaces at room temperature, forming alkoxide and hydroxide groups. Adsorbed alkoxides evolved from the surface in two different reaction channels. About half of the alkoxide species recombined at 345 K with hydroxyl groups and desorbed as the parent alcohols. The rest of the alkoxide groups underwent reactions to produce the corresponding aldehydes, alkenes, and alcohols at temperatures above 550 K. The creation of point defects increased the alkoxide coverage and shifted the product distribution toward the high-temperature channel, favoring alkoxide decomposition over recombination. Within the decomposition products, formation of the dehydration product (alkene) was promoted at the...
Nocturnal asthma and timing of treatment

Nocturnal deterioration of pulmonary function in asthmatic patients is a well-recognized and well-documented phenomenon. The mechanism of this "morning dip," however, remains uncertain. Although the circadian rhythms of body temperature, corticosteroid, catecholamine, histamine, and opiate peptide levels, and even sleep itself have been shown to be in phase with the diurnal variation in asthma, a causal relationship has yet to be established. Increased nighttime bronchial reactivity to histamine, acetylcholine, and house dust allergen have been demonstrated. In general, continuous treatment with theophylline, beta-adrenergic agonists, or corticosteroids attenuates the degree of morning dip but does not completely eliminate the circadian rhythm of asthma. The significance of nocturnal asthma is emphasized by the observation that asthma deaths occur more frequently during nighttime hours and are often preceded by large daily swings in peak expiratory flow. Further studies examining the etiology and treatment of nocturnal asthma are needed.
High-Accuracy Settling Time Measurements

Methods are described for measuring the settling times and other dynamic characteristics of voltage and current output D/A converters (DAC's), operational amplifiers, and precision voltage step generators. Circuits are described for measuring voltage-output device settling times as short as 1?s to within a settling error of ±2 ppm, and current-output device settling times as short as 40 ns to within a settling error of ±0.012 percent.
Transformational Leadership and Healthcare

There are numerous published observations, surveys and recommendations that provide insight and advice on how to become an effective leader in healthcare, although much of this literature is not empirically based. This paper reviews the basic tenets and approach to transformational leadership and describes it in the context of several factors that are important for adoption in the healthcare environment. Transformational leadership is an empirically based form of leadership whose basic tenets and approach make it appealing for greater adoption in health care settings. Medical trainees at all levels and their supervisors should be trained in the principles and application of transformational leadership.
Pancreatic head excavation: a variation on the theme of duodenum-preserving pancreatic head resection.

Hypothesis Despite the introduction of new methods for duodenum-preserving pancreatic head resection, such as the Beger and Frey procedures, the management of benign lesions of the proximal pancreas remains controversial. We developed a modification of the duodenum-preserving pancreatic head resection in which the proximal pancreatic duct or central core of the pancreatic head is excised by ultrasonic dissection and examined the feasibility, safety, and outcomes of this new procedure. Design and Setting Prospective cohort study in an academic tertiary care referral center. Patients From April 1, 2001, to September 8, 2003, 6 patients with either chronic pancreatitis (4) or benign tumors of the pancreatic head (2) underwent ultrasonic excavation of the pancreatic head, with reconstruction by a single longitudinal, Roux-en-Y pancreaticojejunostomy. Main Outcome Measures Safety and cost were assessed by measures of operative time, blood loss, nasogastric drainage, and length of stay. Any complications and the degree of full functional recovery were noted. Results The technique of ultrasonic excavation of the central pancreatic head is reviewed in detail. Operative time ranged from 344 to 427 minutes (average, 390 minutes); blood loss ranged from 200 to 1300 mL (average, 475 mL); nasogastric drainage ranged from 3 to 5 days; and length of stay ranged from 6 to 8 days. No major complications occurred. Two patients had transient, probable drug-related ileus after discharge. All patients had full functional recovery. Conclusions Our modification of the technique of duodenum-preserving pancreatic head resection using ultrasonic dissection and longitudinal reconstruction appears feasible, safe, and effective for benign disease of the proximal pancreas.
Dose escalation with three-dimensional conformal radiation therapy affects the outcome in prostate cancer.

Abstract Purpose: Three-dimensional conformal radiation therapy (3D-CRT) is a technique designed to deliver prescribed radiation doses to localized tumors with high precision, while effectively excluding the surrounding normal tissues. It facilitates tumor dose escalation which should overcome the relative resistance of tumor clonogens to conventional radiation dose levels. The present study was undertaken to test this hypothesis in patients with clinically localized prostate cancer. Methods and Materials: A total of 743 patients with clinically localized prostate cancer were treated with 3D-CRT. As part of a phase I study, the tumor target dose was increased from 64.8 to 81 Gy in increments of 5.4 Gy. Tumor response was evaluated by post-treatment decrease of serum prostate-specific antigen (PSA) to levels of ≤1.0 ng/ml and by sextant prostate biopsies performed ≥2.5 years after completion of 3D-CRT. PSA relapse-free survival was used to evaluate long-term outcome. The median follow-up was 3 years (range: 1–7.6 years). Results: Induction of an initial clinical response was dose-dependent, with 90% of patients receiving 75.6 or 81.0 Gy achieving a PSA nadir ≤1.0 ng compared with 76% and 56% for those treated with 70.2 Gy and 64.8 Gy, respectively ( p p p p Conclusions: The data provide evidence for a significant effect of dose escalation on the response of human prostate cancer to irradiation and defines new standards for curative radiotherapy in this disease.
Protein folding: Protection from the outside.

Protein folding is a high-stakes process, with cell dysfunction and death being the unforgiving penalties for failure. Work in bacteria hints that organisms manage this process beyond the boundaries of the cytoplasm — and even the cell.
Environmental influences, employment status, and religious activity predict current cigarette smoking in the elderly

Abstract The objective of this study was to describe the smoking histories, patterns of cigarette use, and quitting behaviors in a predominantly African American sample of older adults. Study participants were a convenience sample of senior center attendees in the Washington, DC metropolitan area. Self-report questionnaires were used to measure depression, nicotine dependence, smoking motives, and readiness to quit. Results showed that living with another smoker increased the likelihood of current smoking (odds ratio=2.07, 95% CI=1.72–36.73). Being employed or seeking work was also associated with a higher likelihood of current smoking (odds ratio=2.73, 95% CI=2.00–118.76). Subjects who reported less frequent participation in organized religious activities were also more likely to smoke (odds ratio=2.04, 95% CI=1.17–50.38). Both former and current smokers identified personal will power and physician advice as the two most influential factors in successful smoking cessation. However, current smokers believed that nicotine replacement would aid in a successful cessation attempt, while former smokers did not endorse the efficacy of these products. The findings are discussed in terms of implications for intervention.
Detailed Spectroscopic and Theoretical Studies on [Fe(EDTA)(O2)]3-: Electronic Structure of the Side-on Ferric−Peroxide Bond and Its Relevance to Reactivity

A spectroscopic study of the Fe(III)−EDTA−peroxide complex using electron paramagnetic resonance (EPR), low-temperature absorption (LT-ABS), variable-temperature−variable-field (VTVH) magnetic circular dichroism (MCD), and resonance Raman (rR) spectroscopies is reported. Density functional (DFT) and INDO/S-CI molecular orbital (MO) calculations are used to derive an experimentally calibrated bonding scheme. The molecule is described as a 6-coordinate, mononuclear, high-spin ferric−peroxide complex with a side-on η2-FeO2 arrangement. EPR spectroscopy shows that the zero-field splitting (ZFS) is negative with D = −1.0 ± 0.25 cm-1 and E/D = 0.21. MCD and LT-ABS spectroscopies lead to the identification of at least six excited states below 35 000 cm-1. The lowest two are assigned as ligand field sextet→quartet transitions, and the remaining transitions have peroxide to iron ligand-to-metal charge transfer (LMCT) character. The polarization of the LMCT bands in the principal axis system of the D-tensor are der...
Metabolism of a disulfiram metabolite, S-methyl N,N-diethyldithiocarbamate, by flavin monooxygenase in human renal microsomes.

S-Methyl N,N-diethyldithiocarbamate (MeDDC), a metabolite of the alcohol deterrent disulfiram, is converted to MeDDC sulfine and then S-methyl N,N-diethylthiocarbamate sulfoxide, the proposed active metabolite in vivo. Several isoforms of CYP450 and to a lesser extent flavin monooxygenase (FMO) metabolize MeDDC in the liver. The human kidney contains FMO1 and several isoforms of CYP450, including members of the CYP3A, CYP4A, CYP2B, and CYP4F subfamilies. In this study the metabolism of MeDDC by the human kidney was examined, and the enzymes responsible for this metabolism were determined. MeDDC was incubated with human renal microsomes from five donors or with insect microsomes containing human FMO1, CYP4A11, CYP3A4, CYP3A5, or CYP2B6. MeDDC sulfine was formed at 5 microM MeDDC by renal microsomes at a rate of 210 +/- 50 pmol/min/mg of microsomal protein (mean +/- S.D., n = 5) and by FMO1 at 7.6 +/- 0.2 nmol/min/nmol (n = 3). Oxidation of 5 microM MeDDC was negligible by all CYP450 tested (< or =0.03 nmol/min/nmol). Inhibition of FMO by methimazole or heat diminished MeDDC sulfine formation 75 to 89% in renal microsomes. Inhibition of CYP450 in renal microsomes by N-benzylimidazole or antibody to the CYP450 NADPH reductase had no effect on MeDDC sulfine production. Benzydamine N-oxidation, a probe for FMO activity, correlated with MeDDC sulfine formation in renal microsomes (r = 0.951, p = 0.013). The K(M) values for MeDDC sulfine formation by renal microsomes and recombinant human FMO1 were 11 and 15 microM, respectively. These results demonstrate a role for the kidney and FMO1 in the metabolism of MeDDC in humans.