cssi/SciSciGPT-SciSciNet huggingface dataset:
Penicillin-binding proteins in Streptococcus agalactiae: a novel mechanism for evasion of immune clearance

Group B streptococci (GBS) remain the most significant bacterial pathogen causing neonatal sepsis, pneumonia and meningitis in the USA despite CDC-recommended chemoprophylaxis strategies for preventing infection. To cause infection pathogens such as GBS must evade recognition and clearance by the host's immune system. Strategies for avoidance of opsonization and phagocytic killing include elaboration of antiopsonophagocytic capsules and surface proteins. During screening for mutants of GBS that were attenuated for virulence in a neonatal rat sepsis model, we identified a mutant with a transposon insertion in the ponA gene. ponA encodes an extra-cytoplasmic penicillin-binding protein PBP1a, a newly identified virulence trait for GBS that promotes resistance to phagocytic killing independent of capsular polysaccharide. Complementation analysis in vivo and in vitro confirmed that the altered phenotypes observed in the mutant were due to the transposon insertion in ponA. Deletion of PBP1a does not affect C3 deposition on GBS suggesting that mechanism by which PBP1a protects GBS from phagocytic killing is distinct from the antiopsonic activity of capsular polysaccharide. This is the first report describing expression of an antiphagocytic surface protein by GBS and represents a novel mechanism for evasion of immune recognition and clearance that may explain the decreased virulence observed in Gram-positive bacterial species for penicillin-binding protein mutants.
Development of a physics-based reduced state Kalman filter for the ionosphere

[1] A physics-based data assimilation model of the ionosphere is under development as the central part of a Department of Defense/Multidisciplinary University Research Initiative (MURI)-funded program called Global Assimilation of Ionospheric Measurements (GAIM). With the significant increase in the number of ionospheric observations that will become available over the next decade, this model will provide a powerful tool toward an improved specification and forecasting of the global ionosphere, with an unprecedented accuracy and reliability. The goal of this effort will be specifications and forecasts on spatial grids that can be global, regional, or local (25 km × 25 km). The specification/forecast will be in the form of three-dimensional electron density distributions from 90 km to geosynchronous altitudes (35,000 km). The main data assimilation in GAIM will be performed by a Kalman filter. In this paper we present a practical method for the implementation of a Kalman filter using a new physics-based ionosphere/plasmasphere model (IPM). This model currently includes 5 ion species (O2+, N2+, NO+, O+, and H+) and covers the low and middle latitudes from 90 km to about 20,000 km altitude. A Kalman filter based on approximations of the state error covariance matrix is developed, employing a reduction of the model dimension and a linearization of the physical model. These approximations lead to a dramatic reduction in the computational requirements. To develop and evaluate the performance of the algorithm, we have used an Observation System Simulation Experiment. In this paper, we will initially present the physics-based IPM used in GAIM and demonstrate its use in the reduced state Kalman filter. Initial results of the filter in the South American sector using synthetic measurements are very encouraging and demonstrate the proper performance of the technique.
The Influence of Culture on Services Marketing Research

Abstract As organizations continue to pursue more global strategies, the need to be able to understand consumers in far away places is increasing. Marketing research is the primary mechanism through which companies understand their current as well as potential customers. While many researchers and practitioners comment on cultural differences, the impact of national culture at the various stages of the research process is frequently not fully realized or even ignored. As companies contemplate the global marketplace, they must consider how domestic market research differs when conducted in international markets. This paper presents a comprehensive understanding of the importance of national culture in conducting international marketing research. A framework is provided to closely examine the relationships between culture, marketing research, and consumer behavior. The paper also discusses marketing research using actual company examples in the service industry. Finally, recommendations for researchers cons...
Light Actuation of Graphene-Oxide Incorporated Liquid Crystalline Elastomer Nanocomposites

The authors demonstrate high-performance photo-actuation of nematic liquid crystal elastomer (LCE) nanocomposites incorporating graphene oxide (GO). The nematic LCE serves as the matrix with reversible thermomechanical response. The incorporated GO absorbs photons and converts the photonic energy to heat, thus actuating the LCE nanocomposite. Both infrared and visible lights of wide spectrum (white light) or various wavelength ranges irradiations are able to effectively actuate the LCE nanocomposites, thus proves that they can fully utilize the photo energy of a light source for their mechanical actuation. Attributed to the well dispersity of GO in LCE matrix, sensitive (in seconds) and reversible photo-induced strain of LCE nanocomposites with consistent shape-changing ratio and significantly enhanced mechanical properties are observed. The contraction of the LCE nanocomposite films under light irradiation is about one third of the original length. The effective load-actuation capability is elevated abou...
Simulation in environmental and ecological systems

Computer simulation continues to be an important tool in understanding and managing environmental and ecological systems. Simulation provides a virtual laboratory within which scenarios can be evaluated and theories can be tested. Some basic principles of simulation, numeral methods, and validation relevant to the simulation domain of interest are reviewed. Several aspects of ecological system simulation are discussed including a focus on population ecology. Several topics in environmental system simulation are covered including a general introduction to modeling and a discussion of climate, plume, and noise modeling. Finally, a discussion on visualization of environmental and ecological systems is presented.
Clinical insights by the presence of bipolar disorder in pseudohypoparathyroidism type 1A

Pseudohypoparathyroidism type 1A and its association with bipolar disorder (BD) have never been reported so far. We report a new case with both clinical entities and discuss the potential pathophysiological mechanisms of this association (protein kinase A hypoactivation, parathyroid hormone, hypocalcemia, protein kinase C activation, vitamin D deficiency). In this patient, the correction of the underlying calcium and vitamin D deficiencies leads to a better BD outcome and lower dosage of psychopharmacological agents. The conclusions might be generalized for a better understanding and management of these conditions.
The use of lipotropic factors in the treatment of liver disease.

During the past decade experimental and clinical studies on the role of nutrition in the production and prevention of liver disease have aroused considerable interest in the so-called accessory food factors-particularly the lipotropic agents, methionine and choline. Numerous animal experiments have indicated that certain forms of cirrhosis can be prevented or cured by the use of lipotropic factorsl. While there is still some difference of opinion as to the exact relationship between the cirrhosis induced in animals and that occurring in human patients, many factors found to have protective or therapeutic effects in experimental cirrhosis have also been found to be of value in the treatment of the clinical disease. The specific therapeutic value of methionine and choline in patients with liver disease who are already receiving an adequate diet has been difficult to assess. The known variability of the disease, its chronicity, and the tendency for remissions to occur spontaneously add to the difficulty of evaluating any single agent. The clinical evidence available at the present time leaves considerable doubt as to the value of supplementing the accepted cirrhotic regimen with methionine or choline, although numerous studies have suggested that these factors may exert a favorable influence2• It is obvious that the therapeutic value of methionine or choline in patients with liver disease cannot be determined from routine clinical or laboratory studies. It is generally agreed, however, that both choline and methionine act as lipotropic factors, being either precursors for the formation of phospholipids or essential constituents of these phospholipids which are necessary for the normal removal of fat from the liver. Two procedures have proven of considerable value in the study of this important phase of liver function. The first, not previously used in human patients, is the measurement of the phospholipids entering the blood by way of the liver. This is made possible by the use of the radioactive isotope P32, which is rapidly incorporated into the newly formed phospholipids3• Since the liver is the main, if not the sole, source of the plasma phospholipids4, it would appear that the rate of formation of phospholipids in the liver would be re* This investigation was supported in part by a research grant from the Division of Research Grants and Fellowships of the National Institutes of Health, U. S. Public Health Service. The p32 used in these experiments was obtained from the National Laboratories, Oak Ridge, Tennessee, on allocation from the United States Atomic Energy Commission. t Read at the 52nd Annual Meeting of the American Gastroenterological Association, June, 1951.
Review of Bardo Fassbender and Anne Peters eds., The Oxford Handbook of the History of International Law (2012)

This is a brief review of The Oxford Handbook of the History of International Law, edited by Bardo Fassbender and Anne Peters (2012). In this volume, the editors explicitly seek to map a path "towards a global history of international law." By any measure, the book is a substantial achievement, and it will be widely and rewardingly consulted for many years to come. Yet even with all the knowledge assembled in its thousand-plus pages, the Handbook is unable to accomplish in full what it set out to achieve.
Syndrome of inappropriate antidiuretic hormone associated with chemotherapy-induced tumour lysis in small-cell lung cancer: Case report and literature review

A patient with a small-cell lung cancer (SCLC) developed an asymptomatic hyponatremia, with all features of the syndrome of inappropriate antidiuretic hormone secretion (SIADH), two days after the start of his first cycle of chemotherapy with vindesine, ifosfamide and cisplatin. Progression of the tumour with an increase in paraneoplastic SIADH, or drug-induced causes of hyponatremia, could be ruled out by his further clinical course. The event was interpreted as a consequence of ADH release during the initial tumour cell lysis after effective chemotherapy. The occurrence of hyponatremia during the initial phase of chemotherapy for SCLC should be interpreted with caution. Although it is most commonly due to an increase in paraneoplastic ADH secretion reflecting ineffective therapy, it can also be due to release of ADH from malignant cells in the period of rapid tumour lysis, reflecting effective therapy. Based on this rare occurrence, a review of the aetiology, clinical findings, diagnosis, prognosis and treatment of SIADH in general is presented.
After the Wedding Party

The light bent back the branches, where a mockingbird purled like a hack on trombone. I was involved in a physical act I was unable to understand ?in love, but also walking back to the dining car on a train going 80 miles an hour. I strongly believed the Truth was a fixed point in the trees, watching me travel through the southern nightfall backwards recklessly. I misunderstood. My lover cradled a camera to her weakened eyes?"I want to take a picture of where the night just was." Common decency forbade me from expressing my love down her shirt under the mothering eye of a town's watertower. The tower said "Smile America" and "I plugged Heather Griggs."
The fine structure of the terminal branches of the hepatic arterial system of the rat

The fine structure of the smallest branches of the hepatic arterial system of the rat was studied with the light and electron microscope by means of alternate thick and thin serial sections. The terminal arborizations of the hepatic artery closely follow the pattern of the portal vein and give rise to a dense network of capillaries in the periportal connective tissue which closely surrounds the bile ducts. These periductal capillaries end by joining (a) interlobular veins, (b) terminal distributing veins, (c) sinusoids directly or, (d) sinusoids in common with branches of the portal vein. The capillaries arising from larger arterioles have well developed precapillary sphincters at their origins, while those arising from terminal arterioles have less prominent smooth muscle cuffs. There are no smooth muscle sphincters at the terminal ends of the capillaries where they join branches of the portal vein or sinusoids. Large endothelial cells usually guard these junctions and frequently their nuclei bulge into the lumens of the vessels and may close them off. Occasionally unmyelinated nerves with vesicles about 500 A in diameter, some of which are granulated, are in close proximity to the endothelial cells of the capillaries. Endothelial cells also guard the beginnings of sinusoids originating from the portal vein. The sinusoids arising from periductal capillaries are identical in structure to those directly off from the portal vein. Initially the sinusoids from both types of vessels are like capillaries, with a continuous basement membrane around them and an unfenestrated endothelium. A short distance into the parenchyma they lose their basement membrane, become fenestrated and are typical sinusoids.
Molecular Conformation of Dihydrouridine: Puckered Base Nucleoside of Transfer RNA

The crystal structure of dihydrouridine hemihydrate has been determined by x-ray diffraction. Crystals of dihydrouridine contain two independent molecules in the asymmetric unit and a molecule of water. The x-ray structure determination has shown that the conformations of both molecules differ in important respects in the saturated base and the ribose. The molecular conformation of dihydrouridine has, for the first time, provided structural evidence that the rare nucleoside can proinote "loop" formation in the sugar-phosphate chain.
Model for human use of motion cues in vehicular control

A feedback model for human use of motion cues in tracking and regulation tasks is offered. The motion cue model is developed as a simple extension of a structural model of the human pilot, although other equivalent dynamic representations of the pilot could be used in place of the structural model. In the structural model,it is hypothesized that proprioceptive cues and an internal representation of the vehicle dynamics allow the human to create compensation characteristics that are appropriate for the dynamics of the particular vehicle being controlled. It is shown that an additional loop closure involving motion feedback can improve the pilot/vehicle dynamics by decreasing high-frequency phase lags in the effective open-loop system transfer function. Data from a roll-attitude tracking/regulation task conducted on a moving base simulator are used to verify the modeling approach.
PROPAGATION OF STATISTICAL COUNTING ERROR TO THE PARAMETERS OF A LORENTZIAN.

Abstract It is shown that under some general conditions the uncertainties of least-squares fitted parameters can be estimated before the data are accumulated. Special cases concerning Lorentzian absorption lines are considered in detail.
PROTEOSE INTOXICATIONS AND INJURY OF BODY PROTEIN : V. THE INCREASE IN NON-PROTEIN NITROGEN OF THE BLOOD IN ACUTE INFLAMMATORY PROCESSES AND ACUTE INTOXICATIONS.

Sterile abscess formation in the dog is accompanied by a large increase in output of urinary nitrogen and also by a small but definite increase in the blood non-protein nitrogen. All this nitrogenous material of course is derived from body protein injury and autolysis. Septic inflammation in the dog (pleurisy, pneumonia, peritonitis, etc.) likewise shows a distinct rise in the blood non-protein nitrogen. This rise is not often so great as that frequently observed in the intoxication of intestinal obstruction. Many acute infections in man (septicemia, peritonitis, pneumonia, etc.) show a definite rise in the non-protein nitrogen and urea nitrogen of the blood; some cases show a very great rise above normal (over 100 mg. of non-protein nitrogen per 100 cc. of blood). There may be no anatomical change in the kidney beyond the familiar picture of cloudy swelling. This does not exclude the possibility of some transient functional derangement of the kidney epithelium. Certain obscure intoxications in man may show a considerable rise in the non-protein nitrogen of the blood, indicating a large amount of protein disintegration. These findings must be taken into account in any clinical analysis and interpretation of high non-protein nitrogen of the blood in pathological conditions.
Electropolymerized Films of Macromeric Assemblies.

The polymer poly[4-(2-aminoethyl)styrene], prepared by living anionic polymerization, has been derivatized by amide coupling to [RuII(vbpy)2(4-CO2H-4‘-CH3bpy)]2+ (vbpy is 4-vinyl-4‘-methyl-2,2‘-bipyridine; 4-CO2H-4‘-CH3bpy is 4-methyl-2,2‘-bipyridine-4‘-carboxylic acid). The resulting “macromer” can be electropolymerized on a variety of electrode materials by reductive electropolymerization. Compared to similar films of poly[RuII(vbpy)3](PF6)2: (1) the macromeric films are considerably rougher, apparently having open, local microporous structures; (2) they undergo comparable rates of intrafilm charge transfer; and (3) they have shortened metal-to-ligand charge transfer (MLCT) excited state lifetimes, apparently due to quenching by film-based trap sites. Stable films of a mixed polymer have also been prepared by sequential addition of [RuII(bpy)2(4-CO2H-4‘-CH3bpy)]2+ and then the vbpy derivative.
Reliability and Validity of a Measure of Preschool Teachers' Attributions for Disruptive Behavior

Research Findings: This study examined the quality of teacher attributions for child disruptive behavior using a new measure, the Preschool Teaching Attributions measure. A sample of 153 early childhood teachers and 432 children participated. All teachers completed the behavior attributions measure, as well as measures regarding demographics, beliefs, self-efficacy, child behavior, and the quality of the teacher–child relationship with selected children. Confirmatory factor analysis demonstrated that the hypothesized 2-factor model fit significantly better than a 1-factor model, with the 2 factors being Causal and Responsibility. The resulting Causal and Responsibility subscale scores had solid internal consistency as measured by Cronbach's alpha coefficients. Significant bivariate and partial correlations with teacher practices and beliefs provided preliminary support for the measure's construct validity. Practice or Policy: Findings from this study suggest the importance of including a measure of teache...
Commissural nucleus of the solitary tract lesions reduce food intake and body weight gain in rats

This study investigated the effects of an electrolytic lesion of the commissural subnucleus of the nucleus of the solitary tract (commNTS) on body weight, daily food and water intake, and plasma glucose and insulin in rats. In the first 6 days following brain surgery, commNTS lesioned rats reduced daily food intake by 80% compared to rats with sham lesions. After this period rats with lesions of commNTS started recovering food intake, but intake remained significantly reduced until the 12th day after surgery. A reduction in body weight was observed 4 days after surgery and reached a maximum on the 12th day. After this, a partial recovery of body weight was observed, but weight remained significantly reduced compared to weights of rats with sham lesions through the conclusion of the study. Food intake and body weight gain in other rats with partial lesions of the commNTS or with lesions outside the commNTS did not differ from rats with sham lesions with regard to those variables. Daily water intake and plasma glucose and insulin were not changed by the commNTS lesions. These results suggest that commNTS is involved with mechanisms that control food intake and body weight in rats.
Testing for scaling in natural forms and observables

The general procedure of calculating fractal dimensions or other exponents is based on estimating some quantity as a function of scale and on assessing whether or not this function is a power law. This power law manifests itself in a log (quantity) versus log (scale) plot as a linear region (scaling). It has thus become the practice to estimate dimensions by the slope of some linear region in those log-log plots. When we are dealing with exact fractals (the Koch curve, for example) there are no problems. When, however, we are working with natural forms or observables, problems begin to emerge. In such cases the scaling region is subjectively estimated and often is only the result of the generic property of the quantity to increase monotonically or decrease monotonically as the scale goes to zero irrespective of the geometry of the object. Here we discuss these issues and suggest a procedure to deal with them.
Monte Carlo simulations of image stacking

In image stacking, we combine multiple x-ray angiography images with incomplete arterial filling into a single output image with more completely filled arteries. Among other applications, image stacking is useful in neuroangiography embolization and in CO2 angiography. Using Monte Carlo simulations and tests on clinical image sequences, we compare three methods: (1) traditional extreme-intensity (EI) which consists of a max-dark or max-light operation on the sequence, (2) matched filtering (MF) with spatially varying parameters, and (3) a new algorithm, trimmed-extreme-intensity (TEI). In the simulations, we use Poisson noise and model the time-course of the arterial contrast signal with a gamma variate curve. The figure of merit for comparisons is the contrast-to-noise (CNR) ratio. We find that our spatially-dependent MF method works well with image which have a well-defined direction of flow as in the legs, but not with more complex flow patterns as in neuroangiography. On clinical images, TEI gives good results and is more robust than MF.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Risk-taking behaviors engaged in by early adolescents while on school property.

Purpose. This longitudinal study was guided by a Youth Resilience Framework. The study purpose was to examine the influence of protective resources, contextual factors, and risk factors in middle childhood (grades 4–6) on health-risk behaviors (e.g., smoking cigarettes, using marijuana, drinking alcohol, carrying a weapon) engaged in on school property by early adolescents (grade 7) who live in rural central Texas. Methods. Students in grades 4 to 6, a majority of whom were Mexican American (54.3%) and male (56.4%), completed surveys annually until the 7th grade. Generalized estimating equations were run to determine predictors of 7th graders’ health-risk behaviors on school property. Results. Engaging in healthy behaviors, knowing others cared about them, and having a sense of competence in middle childhood (grades 4–6) were found to be protective factors, while having a large family size and the expectation that they would not complete school were found to be risk factors for engaging in health risk beh...
A Hybrid Cloud Detection Algorithm to Improve MODIS Sea Surface Temperature Data Quality and Coverage Over the Eastern Gulf of Mexico

Cloud contamination can lead to significant biases in sea surface temperature (SST) as estimated from satellite measurements. The effectiveness of four cloud detection algorithms for the Moderate Resolution Imaging Spectroradiometer (MODIS) in retaining valid SST data and masking cloud-contaminated data was assessed for all 2125 daytime and nighttime images during 2010 over the eastern Gulf of Mexico and including the east coast of Florida. None of the cloud detection algorithms was found to be sufficient to reliably differentiate clouds from valid SST, particularly during anomalously cold events. The strengths and weaknesses of each algorithm were identified, and a new hybrid cloud detection algorithm was developed to maximize valid data retention while excluding cloud-contaminated pixels. The hybrid algorithm was based on a decision tree, which includes a set of rules to use existing algorithms in different ways according to time and location. Comparing with >10000 concurrent in situ SST measurements from buoys, images processed with the hybrid algorithm showed increases in data capture and improved accuracy statistics over most existing algorithms. In particular, while keeping the same accuracy, the hybrid algorithm resulted in nearly 20% more SST retrievals than the most accurate algorithm (Quality SST) currently being used for operational processing. The increases in both data coverage and SST range should improve MODIS data products for more reliable SST retrievals in near real time, thus enhancing the ocean observing capacity to detect anomaly events and study short- and long-term SST changes in coastal environments.
The effect of donor atom and ligand size on the molecular and solid state structure of selected tin (IV) compounds

Abstract The arrangement of bonded and nonbonded atoms surrounding the central tin atom in several methyltin halide and pseudohalide compounds has been calculated using a stereochemical model that takes into account the spatial requirements of atoms. Inherent in the analytical procedure is a parameter which provides a measure of the validity of the calculations when applied to a particular compound. The technique calculates an optimum ligand arrangement based upon a balancing of nonbonded intramolecular interactions; the procedure is then completed by calculating the distances of the Sn…X intermolecular interactions that occur when the approach of the associating atom is restricted only by the van der Waals contacts of the ligands on the central tin atom. In general, the calculations reproduce or account for the structural features of the methyltin compounds of known structure. The calculations show that the (CH3)3SnX, (CH3)2SnX2, and CH3SnX3 molecules have ligand arrangements that may accommodate, 1, 2, or 3 strong intermolecular interactions, respectively. This agrees with the known tendency of (CH3)3SnX compounds to possess five-coordination and (CH3)2SnX2 compounds to exhibit six-coordination. The calculated strengths of the intermolecular interactions vary in the order Sn…F > Sn…Cl > Sn…Br > Sn…I. Also, the strength of a particular type of Sn…X intermolecular interaction in a series of (CH3)nSnX4−n compounds varies in the order (CH3)3SnX > (CH3)2SnX2 > CH3SnX3. These calculations correlate with the observed variations in the discretely molecular or polymeric character of the solid states.
The carbon and energy budgets of energy crops

Abstract Global warming is said to be caused by the build up of active greenhouse gases in our atmosphere and carbon dioxide — released on the combustion of fossil fuels is thought to be the most important of these. Agricultural crops, grown specifically for use as a fuel source, might play an important role in reducing our consumption of fossil fuel sources through substitution. However, in order to fully qualify as a “beneficial crop” it must be clearly shown that production entails a net benefit in terms of energy output to energy input i.e.; it has a positive energy balance. This paper considers the difficulties in assessing both carbon and energy budgeting. It describes a recently developed computer model which attempts to define the energy and carbon inputs and outputs of the leading UK energy crop, that is of short rotation coppice (SRC). Preliminary results show that SRC, when displacing fossil fuel, has a very positive energy yield with the added benefit of carbon saving in terms of offset emissions. The computer model takes account of direct and indirect energy and carbon inputs to the crop, allowing the model user to determine the sensitivity of individual cropping operations including establishment, fencing, harvesting operations, rotation and cutting cycle variations, the impact of field size, transport distance from the farm to the point of utilisation, the energy cost of storage and drying. Each management decision influences the final energy or carbon ratio of the SRC crop. Such complexity makes a definitive statement on the energy/carbon ratio for crop production difficult, however if a standard management system is adopted (as described later) the energy ratio of growing SRC for fuel may be assigned. In the case examined here a ratio of 30 : 1 (energy units produced : used) is reported. However, this ratio is sensitive to variation in crop yield and management efficiency and so, although the ratio is positive, this should not encourage a wasteful attitude to crop management systems. In terms of carbon balances, the most important consideration is the substitution value of the material in relation to fossil fuels. In this paper, figures presented refer to wood substituted for coal use and pertain to a field area of 1 hectare (ha). If field size is increased up to 3ha, then the energy and carbon ratios improve by approximately 15 %.
A transport-flux-based directed relation graph method for the spatially inhomogeneous instantaneous reduction of chemical kinetic mechanisms

Abstract A novel, flux-based, directed relation graph (DRG) method is proposed for adaptive and automatic generation of skeletal chemical mechanisms. Unlike many previous approaches for static mechanism reduction, the proposed method does not rely on the complete solution of a set of test problems using the detailed mechanism, but rather it simplifies the model “on the fly,” analyzing the local reaction states with an extended directed relation graph. Compared to the original DRG method of Lu and Law [T. Lu, C.K. Law, Proc. Combust. Inst. 30 (2005)], the flux-based DRG explicitly considers the effect of transport fluxes, as they provide a way to quantify the coupling of the governing equations among adjacent grid cells. The resulting numerical scheme operates on a cell-by-cell basis, so that different chemical submodels are applied in different regions of the flame. This approach leads to very large reduction ratios, in which most of the flame structure is resolved using about 30% of the chemical species employed in the full mechanism, while a more detailed model that considers roughly 70–80% of the total species is used only at ignition. The flux-based DRG method has been employed in the two-dimensional simulation of axisymmetric coflow flames for a variety of fuels and chemical kinetic mechanisms (three steady flames and one oscillating flame), with a speedup factor of about 20 obtained for the largest problem — a JP-8 flame.
Oxidation kinetics of partially reduced vanadyl pyrophosphate catalyst

Abstract The oxidation kinetics of partially reduced vanadyl pyrophosphate (VPO) catalyst were investigated with a novel oscillating microbalance reactor. The oxidation rate of partially reduced VPO catalyst with oxygen is close to half-order with respect to oxygen partial pressure. The activation energy for this oxidation is 70 kJ mol−1. The kinetics obtained from the transient reaction study are applicable in the design and optimization of the circulating fluidized bed riser reactor process for the selective oxidation of butane to maleic anhydride.
Structural and kinetic characterization of an acyl transferase ribozyme.

We have previously isolated, by in vitro selection, an acyl-transferase ribozyme that is capable of transferring a biotinylated methionyl group from the 3‘ end of a hexanucleotide substrate to its own 5‘-hydroxyl. Comparison of the sequences of a family of evolved derivatives of this ribozyme allowed us to generate a model of the secondary structure of the ribozyme. The predicted secondary structure was extensively tested and confirmed by single-mutant and compensatory double-mutant analyses. The role of the template domain in aligning the acyl-donor oligonucleotide and acyl-acceptor region of the ribozyme was confirmed in a similar manner. The significance of different domains of the ribozyme structure and the importance of two tandem G:U wobble base pairs in the template domain were studied by kinetic characterization of mutant ribozymes. The wobble base pairs contribute to the catalytic rate enhancement, but only in the context of the complete ribozyme; the ribozyme in turn alters the metal binding pro...
Wntless in Wnt secretion: molecular, cellular and genetic aspects

Throughout the animal kingdom, Wnt-triggered signal transduction pathways play fundamental roles in embryonic development and tissue homeostasis. Wnt proteins are modified as glycolipoproteins and are secreted into the extracellular environment as morphogens. Recent studies on the intracellular trafficking of Wnt proteins demonstrate multiple layers of regulation along its secretory pathway. These findings have propelled a great deal of interest among researchers to further investigate the molecular mechanisms that control the release of Wnts and hence the level of Wnt signaling. This review is dedicated to Wntless, a putative G-protein coupled receptor that transports Wnts intracellularly for secretion. Here, we highlight the conclusions drawn from the most recent cellular, molecular and genetic studies that affirm the role of Wntless in the secretion of Wnt proteins.
Energetics of cooperative protein-DNA interactions: comparison between quantitative deoxyribonuclease footprint titration and filter binding

Using the binding of cI repressor protein to the lambda right and left operators as a model system, we have analyzed the two common experimental techniques for studying the interactions of genome regulatory proteins with multiple, specific sites on DNA. These are the quantitative DNase footprint titration technique [Brenowitz, M., Senear, D. F., Shea, M. A., & Ackers, G. K. (1986) Methods Enzymol. 130, 132-181] and the nitrocellulose filter binding assay [Riggs, A., Suzuki, H., & Bourgeois, S. (1970) J. Mol. Biol. 48, 67-83]. The footprint titration technique provides binding curves that separately represent the fractional saturation for each site. In principle, such data contain the information necessary to determine the thermodynamic constants for local site binding and cooperativity. We show that in practice, this is not possible for all values of the constants in multisite systems, such as the lambda operators. We show how these constants can nevertheless be uniquely determined by using additional binding data from a small number of mutant operators in which the number of binding sites has been reduced. The filter binding technique does not distinguish binding to the individual sites and yields only macroscopic binding parameters which are composite averages of the various local site and cooperativity constants. Moreover, the resolution of even macroscopic constants from filter binding data for multisite systems requires ad hoc assumptions as to a relationship between the number of ligands bound and the filter retention of the complex. Our results indicate that no such relationship exists. Hence, the technique does not permit determination of thermodynamically valid interaction constants (even macroscopic) in multisite systems.
Hassles, Role Strain, and Peer Relations in Young Adolescents:

The impact of hassles, or daily stressors, on the lives of adults has been demonstrated by Lazarus and his colleagues. Conceptual relevance of the hassles construct for young adolescent populations, theoretical interplay between self-reported hassles and role strain in youth, and the relationship between role strain and adolescent peer relations have received scant research attention to date. To address these issues, the authors developed the Adolescent Hassles Inventory (AHI), patterning it after the Hassles Scale developed for adults by Kanner, Coyne, Schaefer, and Lazarus, and administered it to 246 sixth grade students. AHI reliability data supported feasibility of the measurement approach for young adolescents. Factor analysis of the condensed 50-item AHI scale revealed eight item clusters, five of which suggested underlying scale dimensions reflecting adolescent roles of student, peer, drug user/non-user, son/daughter, and worker. Subscales created from item factor loading data correlated significan...
Women in Science: Should we bother with a Psychoanalytic Viewpoint?

This essay enjoins Lacanian psychoanalysis to address a recurrent question in the philosophy of science regarding the role of gender (or perhaps other social categories) in the production of objective knowledge. Are social categories “merely empirical” and thus mitigated by the formal procedures of scientific investigation or is gender somehow implicated in the constitution of knowledge itself? Evelyn Fox Keller, in her monumentally influential work on gender and science, makes the case for a constitutive effect. This essay, using data from a year-long study of science labs and the concepts of Lacan, attempts to further Fox Keller's project by substituting object relations and the categories one thus has at one's disposal with an understanding of the structural effects of language (as limitation and the introduction of difference) as these are graphed on to embodied being, giving forms of what culture reveres as sexual difference – the phallic one vs the Other. Implications for thinking gender in science are suggested and those for the daily operations of research labs are also noted.
Assessing quality improvement initiatives when expert judgements are uncertain

A new approach for examining quality improvement initiatives regarding errors in the US Census Bureau's Master Address File (MAF) and the Topologically Integrated Geographic and Referencing System (TIGER) databases is presented. A stochastic multi-criteria decision-making method involving Bayesian weighted hierarchical multinomial logit models is used to conduct inference on the priorities in a multiple-expert decision scenario. Quality initiatives regarding basic street address-level address matching, geocoding completeness, and geocoding quality were judged to be the most important for MAF/TIGER improvement at the 95% probability level. The approach allows managers to go one step further in understanding the relative impact of various types of errors on overall quality and thus be better prepared to select approaches to reduce these errors.
The Role of Volunteer Services at Cancer Centers

Volunteer services can be effectively used to provide valuable supportive services to patients with cancer and their family. Providing companionship, a sense of self-worth, information, and respite care are among the important services typically provided by volunteers through outpatient, inpatient, and hospice services. Supportive benefits have been linked with reduced symptoms and may even enhance survival. Offering inpatient and outpatient respite services provides needed relief for family caregivers. Complementary therapies may also be provided through volunteer services, with research studies consistently showing benefits from Reiki and animal-assisted therapy offered through volunteer care.
Increased growth efficiency of Quercus alba trees in a CO2-enriched atmosphere

summary Forests have a prominent role in the global carbon cycle, but their response to a changing atmosphere cannot be measured directly. Experimental observations of small trees in CO2-enriched atmospheres must be interpreted carefully if they are to be relevant to the potential responses of forest trees. We grew1 white oak (Quercus alba L.) saplings for four complete growing seasons in open-top chambers with different partial pressures of atmospheric CO2 White oak saplings produced 58% more dry mass in 50 Pa CO2 and 135% more in 65 Pa, compared with plants in ambient (35 Pa) CO2 Although this result might suggest a substantial potential for increased carbon storage in forests, the large difference in growth rate could be attributed to a stimulation of growth very early in the experiment. There was not a sustained effect of C2 on relative growth rate after the first year, and the increased absolute growth rate could persist only so long as leaf area could increase, a condition that would not occur indefinitely in a forest. Nevertheless, annual stem wood production per unit area (growth efficiency) was 37 %, greater in elevated CO2. This increase in growth efficiency, a response that is consistent across diverse studies, implies a potential increase in carbon sequestration by forests, subject to critical assumptions about forest canopy development in a CO2-enriched atmosphere
Synthesis of endo,exo-7,8,9,10-tetrachlorobicyclo[4.4.0]deca-7,9-diene-3,4-dicarboxylic acid N,N′-bisimides

A one-stage synthesis was developed of N,N′-(3,3′-dimethoxy-4,4′-diphenylmethane)- and N,N′-(1,2-ethane)-endo,exo-7,8,9,10-tetrachlorobicyclo[4.4.0]deca-7,9-diene-3,4-dicarboxylic acids bisimides by reaction of a bisadduct of 1,8,9,10,11,11-hexachlorotricyclo[6.2.1.05,10]-undec-9-ene-4,5-dicarboxylic acid N,N′-R-bisimide with pyridine in DMF. The spatial structure of compounds obtained was established.
Defining nasal bone hypoplasia in second-trimester Down syndrome screening: does the use of multiples of the median improve screening efficacy?

Objective The purpose of this study was to compare the efficacy of the use of nasal bone (NB) multiples of the median (MoM) with the biparietal diameter (BPD)/NB ratio as definitions of NB hypoplasia that is associated with Down syndrome in the second trimester. Study Design We conducted a prospective cohort study of women who underwent an anatomic survey between 16 and 22 weeks of gestation. The fetal NB and other markers of fetal aneuploidy were evaluated. MoMs for the NB length at each gestational age category were calculated and adjusted for maternal race. NB hypoplasia was defined either as an absent NB or by a ratio of the BPD/NB >11 or by NB lengths Results Among 3634 women whose condition was evaluated, NB assessment was obtained in 3197 women (88%). There were 23 cases of Down syndrome that were detected. Receiver operating characteristic curve comparison revealed NB MoM 11. The difference in the sensitivity of 12% (95% CI, −5-31) with the BPD/NB ratio >11 vs with an NB MoM P 11 vs an NB MoM P Conclusion In the second trimester of pregnancy, the use of nasal bone length
Consumer inference and the regulation of consumer information

When consumers are uncertain about the importance of a product attribute, mandatory disclosures have two effects: directly communicating attributes, and an inferential effect that changes how much weight consumers put on product attributes. I model a signaling game between regulators and consumers in which regulators perfectly reveal their private information about the importance of an attribute through the intensive margin of regulation. The model has empirical predictions that distinguish it from traditional models of mandatory disclosure. I also examine inferential mistakes that can lead to over or under-regulation and consumer over or under-estimates of the importance of product attributes.
Tensor products of orthoalgebras

We define a tensor product via a universal mapping property on the class oforthoalgebras, which are both partial algebras and orthocomplemented posets. We show how to construct such a tensor product forunital orthoalgebras, and use the Fano plane to show that tensor products do not always exist.
Steep subthreshold slope nanowire nanoelectromechanical field-effect transistors (NW-NEMFETs)

Significant physical challenges remain for CMOS technology to decrease Ioff as transistor dimension and power supply voltages continue downscaling. However, a fundamental thermodynamic limit in the subthreshold slope SS = |(∂Vg)/(∂lnId)| = ln10 · kBT/q at >60 mV/dec exists at room temperature. We have designed and demonstrated the first semiconductor nanowires (NWs) and nanoelectromechanical system (NEMS) field effect transistor structure (NW-NEMFET). We have previously demonstrated 0.5 ps intrinsic delay and near ballistic operation in quantum confined semiconductor heterostructure NWFETs with diameters less than 15 nm.[1] The current design uses high performance suspended semiconductor NWs as the conduction channel, while the electrostatic pull-in of the NW towards the gate stack enables abrupt switching to the off-state leading to high frequency, low power nanoelectronics. Simulation shows that compared to planar suspended-gate FET (SGFET) design [2], NW-NEMFET allows zero SS with 1015 on-off ratio and near 1V pull-in voltage due to enhanced 3D capacitive coupling, as well as operation at very-high-frequency (VHF) and even ultra-high-frequency (UHF) due to the NW beams high aspect ratio and small dimensions.
Assessing the accuracy of the vibrational infinite order sudden approximation for He+I2(n=5)→He+I2(n′=4,6)

For vibrational excitation, the vibrational infinite order sudden approximation was qualitatively correct using an initial j of 0. The agreement was improved using an average over the initial j states of 0, 2, and 4. For vibrational relaxation, reasonable agreement with experiment was achieved only with the initial j average and n=n.
Understanding and solving probability problems: A developmental study

Abstract Children's understanding of what variables and relations are important in problem structures, and their use of these variables and relations in problem solving, were examined. One hypothesis suggests that knowledge of relevant solution variables is a prerequisite for encoding those variables, which in turn is a prerequisite for learning new strategies that use those variables. An alternative hypothesis holds that knowledge of relevant variables is an outcome, rather than a precursor, of efforts to invent new strategies. In the current studies, children between the ages of 5 and 13 years were given Piaget and Inhelder's (1975, The origin of the idea of chance in children, New York: Norton) two-set, alternative choice probability problems. In Experiment 1, problem understanding was assessed by asking children to construct two-set problems that could test whether a learner understood how to solve a model problem type. In Experiment 2, understanding was assessed by asking children to modify model problems to make them harder for a learner to solve. In both experiments, children modified or reproduced only those properties of model problems used either correctly or incorrectly in solving the models. These results partially support both hypotheses, and suggest a mechanism by which problem solving knowledge develops.