cssi/SciSciGPT-SciSciNet huggingface dataset:
The condensation with partial isolation (CWPI) model of condensation in the solar nebula

— We have developed a nebular condensation model and a computational routine that potentially can account for the unequilibrated mineral assemblages in chondritic meteorites. The model assumes that as condensation proceeds, a specified fraction (called the isolation degree, ξ) of the existing condensate is steadily withdrawn from reactive contact with the residual gas, presumably as a result of the growth and aggregation of condensed mineral grains. The isolated condensates may remain in the condensing system as coarse inert objects; whereas, the mineral grains that are still in reactive contact with residual nebular gases are in the form of fine dust. This paper describes the condensation with partial isolation (CWPI) model of condensation and uses it to study condensation in a nebula of solar composition at a total pressure of 10−5 bar. The systematic isolation of condensates from residual nebular gases has profound effects on the condensation sequence. At ξ values 2.5%, the condensation sequence is also independent of the isolation degree and closely resembles the “inhomogeneous accretion model” or “chemical disequilibrium model” of condensation. In the intermediate range of ξ values, the character of the condensation sequence is very sensitive to the degree of chemical fractionation caused by condensate isolation. The mineralogy of chondritic meteorites is not consistent with condensation sequences having ξ > 2.5; this is an upper limit on the ξ values that is characteristic of condensation in the solar nebula. The mineralogy and chemistry of carbonaceous and enstatite chondrites can be explained by accretion of isolated condensates formed at ξ values of ≤0.1% and 0.7–1.5%, respectively, providing that segregation of the inert coarse objects and fine reactive dust occurred in the nebula. Segregation of these two categories of condensate may have been responsible for the observed volatility-based chemical fractionations among chondritic meteorites.
Environmental implications of power generation via coal-microalgae cofiring

Abstract Electrical power plants are responsible for over one-third of the US emissions, or about 1.7 Gt CO 2 per year. Power-plant flue gas can serve as a source of CO 2 for microalgae cultivation, and the algae can be cofired with coal. The study objective was to conduct a Life Cycle Assessment (LCA) to compare the environmental impacts of electricity production via coal firing versus coal/algae cofiring. The LCA results demonstrate that there are potentially significant benefits to recycling CO 2 toward microalgae production. As it reduces CO 2 emissions by recycling it and uses less coal, there are concomitant benefits of reduced greenhouse gas emissions. However, there are also other energy and fertilizer inputs needed for algae production, which contribute to key environmental flows. Lower net values for the algae cofiring scenario were observed for the following using the direct injection process (in which the flue gas is directly transported to the algae ponds): SO x , NO x , particulates, carbon dioxide, methane, and fossil energy consumption. Lower values for the algae cofiring scenario were also observed for greenhouse potential and air acidification potential. However, impact assessment for depletion of natural resources and eutrophication potential showed much higher values. This LCA gives us an overall picture and impacts across different environmental boundaries, and hence, can help in the decision-making process for implementation of the algae scenario.
The effects of boundary condition asymmetries on the interplanetary magnetic field-moon interaction.

Boundary condition asymmetries inherent in the solar wind flow past the Moon are included in a cylindrical model of the interplanetary magnetic field - Moon interaction. Numerical examinations of the sunward side response of this model are compared in the frequency domain with those of symmetrically excited spherical and cylindrical models and two characteristic differences are observed: the response of the asymmetric model is depressed at low frequencies due to magnetic diffusion around a conducting core, and is flattened at high frequencies because of the finite application time of the incident interplanetary magnetic field. The diffusion of field lines around the core is also evident in the time response of the model in the anti-solar cavity. The above features of the lunar response resulting from boundary condition asymmetries are shown to be evident in observational measurements.
Epidemiology of Human Longevity: The Search for Appropriate Methodology

In contrast to the remarkable progress in genetics of aging of such animal models as yeast, nematodes, and Drosophila, little is known about mechanisms that control human longevity. The main obstacle in human studies is that the opportunities for direct experiments with humans are limited and therefore data collection through observations, i.e., epidemiological methods, are particularly important. To advance scientific knowledge in this area, it is also important to broaden the arsenal of concepts and methods for human longevity studies and to develop alternative tactics to cope with environmental and social confounding. To cope with environmental and social confounding, this paper suggests two robust exploratory tests with low risk of artifactual results, based on the analysis of two kinds of genetic influences on human longevity: (1) parental consanguinity, which increases the proportion of homozygotes in offspring, leading to the expression of recessive traits and an increased incidence of multifactori...
Darwin's missing link—a novel paradigm for evolution education

Microevolutionary mechanisms are taught almost exclusively in our schools, to the detriment of those mechanisms that allow us to understand the larger picture—macroevolution. The results are demonstrable; as a result of the strong emphasis on micro processes in evolution education, students and teachers still have poor understanding of the processes which operate at the macro level, and virtually no understanding at all of the history of life on our planet. Natural selection has become synonymous with the suite of processes we call evolution. This paper makes the case for a paradigm shift in evolution education, so that both perspectives—micro and macro—are given equal weight. Increasingly, issues of bioethics, human origins, cloning, etc., are being cast in a light that requires an understanding of macroevolution. To deny our students access to this debate is to deny the call for universal science literacy. A methodology from professional practice is proposed that could achieve this goal, and discussed in light of its utility, theoretical underpinnings, and historical legacy. A mandate for research is proposed that focuses on learners' understanding of several challenging macroevolutionary concepts, including species, the formation of higher groups, deep time, and hierarchical thinking. © 2006 Wiley Periodicals, Inc. Sci Ed90:767–783, 2006
Normal stages of development of the axolotl. Ambystoma mexicanum.

Abstract Illustrations and descriptions of normal stages of the axolotl Ambystoma mexicanum are given. The time to reach each morphological stage is compared with similar stages in two other species, Ambystoma maculatum and Taricha torosa.
Prosthesis for Correction of Single Ventricle

A prosthetic right ventricular conduit that may be applicable in repair of the single ventricle anomaly is reported. The final conduit evolved from a series of animal experiments, which are described.
The integration of public health and prevention into all years of a medical school curriculum.

Abstract This is one of six short papers that describe additional innovations to help integrate public health into medical education; these were featured in the “Patients and Populations: Public Health in Medical Education” conference. They represent relatively new endeavors or curricular components that had not been explored in prior publications. Although evaluation data are lacking, it was felt that sharing a description of the public health, prevention, population health, and policy (P4) curriculum at the University of Arizona College of Medicine, Phoenix (UACOM-P), would be of value to medical educators.
A PERTURBED-PENDULUM MODEL FOR FLAT-PLATE AUTOROTATION

Abstract Global bifurcations of a perturbed planar-pendulum model for nonconservative systems capable of oscillation and rotation are analysed. The motions correspond to stable and unstable limit cycles following a saddle-node bifurcation. The parameter space may be divided into six regions of topologically distinct behavior. The model is applied to the phenomenon of flat-plate autorotation. Using experimental data, the model parameters are empirically fitted physical quantities. Predictions of angular velocity and the critical values of flow velocity and inertia for the onset of autorotation are in good agreement with the experimental observations of previous investigators.
Social dynamics of mammals: Reproductive success, kinship and individual fitness.

Apparent altruism, in which an individual seemingly decreases its evolutionary fitness by assisting others, can confer benefits if the individual assists kin. Thus, an animal can increase its total or inclusive fitness by producing offspring (direct fitness) and/or helping kin to reproduce (indirect fitness). Although kin selection has been suggested as the mechanism underlying the formation of mammalian societies, many species act as if they attempt to maximize the direct fitness component of their inclusive fitness.
High-Amplitude δ Scuti and SX Phoenicis Stars: The Effects of Chemical Composition on Pulsations and the Period-Luminosity Relation

We present a theoretical study of the radially pulsating δ Scuti and SX Phoenicis variables, concentrating on the blue straggler SX Phoenicis variables found in globular clusters. We have evolved a grid of stellar models with the metal abundance of the globular cluster M55, including models with alpha-enhanced metal abundances, and tested these models for radial pulsations observed in the high-amplitude δ Scuti and SX Phoenicis stars. Our grid includes models with globally enriched helium content to simulate the effects of stellar collisions and global mixing possible in blue stragglers. We find that global enrichment of helium strongly affects the temperature and luminosity of a given star, but the location of the instability strip blue edge and the slope of the period-luminosity (PL) relation are unchanged. This suggests that the PL relation is not affected by blue straggler formation if blue stragglers are fully mixed stellar mergers. Our blue edges and PL relations are in agreement with other theoretical determinations and also with the observational PL relation of M55, but they are not in agreement with the PL relation previously derived for high-amplitude δ Scuti stars in the field. Analysis of the double-mode variable, V41, suggests either that the star may not be pulsating in the first and second overtones as claimed or that normal stellar models may not be accurate models of blue straggler stars.
A test particle Monte Carlo method

Abstract A Monte Carlo technique was developed suitable for investigating rarefield gas dynamics problems. The procedure is based on the ‘test particle’ method. The discontinuous function frequently employed for describing the target molecules' velocity distribution is replaced here by a continuous analytic function, the form of calculations. This modification simplifies the calculations, reduces the computer storage requirements, and facilities the application of the method to multi-dimensional problems. The accuracy and versatility of the technique was evaluated by obtaining solutions to several one dimensional problems for which other results exist.
Two examples in the theory of large deviations

Abstract We consider the usual approach to large deviations via the convex conjugate to log-moment generating function. Our first example shows that in the absence of exponential tightness the procedure may lead to correct results but no point on the graph of the rate function will have a supporting hyperplane. The second example implies that if in addition the condition of strict convexity is dropped, then the lower large deviation bound may fail everywhere.
Fusion-induced differentiation of SV40-infected human keratinocytes

Abstract Cells in cultures of human keratinocytes infected by the oncogenic virus, SV40, were fused by exposure to polyethylene glycol (PEG). Fusion induced differentiation of the infected cells within 1–2 days, as measured by staining with orange G/acid fuchsin and by the production of cornified envelopes. The extent of induced differentiation was found to be correlated with the degree of multinucleation. The inductive effect of fusion was manifest during the early serial passages post-infection, but was eventually lost as the keratinocytes became increasingly transformed over time.
The preschool child: Recent research and its implications for early childhood practice and policy

In a progressive society the education and care of young children should be guided by the best available knowledge. As advancing research forces us to reexamine our understanding of early development, we should reexamine early childhood practices and policies as well. This conviction provided the motivation for this special issue of the Journal of Applied Developmental Psychology and for the conference at The Pennsylvania State University where the articles in this collection were originally presented. All these articles, in various ways, address the challenge of putting early childhood research into practice. This is an especially important time to reconsider the potential applications of early childhood research. Enrollment in early childhood programs has increased dramatically in recent years, leading to increased concern with how to make these programs as beneficial as possible for children. During this same period research on preschool children has also increased dramatically. A constant stream of new findings has led to profound changes in our view of early development, yet the implications of these changes for early childhood practice and policy remain largely unexplored. One consequence of recent research is an increased appreciation for the complexity of development during the preschool years. The theoretical framework that previously dominated early childhood research and practice was quite straightforward in some ways, emphasizing as it did the homogeneous nature of preoperational thinking and the general deficiencies (animism, realism, egocentrism, precausal reasoning) that made preschool children qualitatively different from older children and adults. In contrast to this traditional view, recent research paints a more heterogeneous picture of development during the preschool years, one in which young children are recognized as having a complex mixture of impressive abilities and glaring limitations (e.g., Flavell, Miller, & Miller, 1993). Although this new view of early development may be more accurate than the one it replaces, its implications for early childhood practice remain to be worked out. Some of these implications are explored in the following articles in which researchers who study early development in several domains discuss their recent work and its potential applications. Research that provides a more accurate account of the basic abilities of young
Impact of safety monitoring on error probabilities of binary efficacy outcome analyses in large phase III group sequential trials

In phase III clinical trials, some adverse events may not be rare or unexpected and can be considered as a primary measure for safety, particularly in trials of life-threatening conditions, such as stroke or traumatic brain injury. In some clinical areas, efficacy endpoints may be highly correlated with safety endpoints, yet the interim efficacy analyses under group sequential designs usually do not consider safety measures formally in the analyses. Furthermore, safety is often statistically monitored more frequently than efficacy measures. Because early termination of a trial in this situation can be triggered by either efficacy or safety, the impact of safety monitoring on the error probabilities of efficacy analyses may be nontrivial if the original design does not take the multiplicity effect into account. We estimate the actual error probabilities for a bivariate binary efficacy–safety response in large confirmatory group sequential trials. The estimated probabilities are verified by Monte Carlo simulation. Our findings suggest that type I error for efficacy analyses decreases as efficacy–safety correlation or between-group difference in the safety event rate increases. In addition, although power for efficacy is robust to misspecification of the efficacy–safety correlation, it decreases dramatically as between-group difference in the safety event rate increases. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of salinity-dependent hydraulic conductivity on saltwater intrusion episodes

Abstract The ionic strength of percolating water can greatly alter a soil's hydraulic conductivity. This appears to be the result of dispersion and/or swelling of clay particles, and can alter hydraulic conductivity by several orders of magnitude. In this paper, the potential effects of salinity-dependent changes in hydraulic conductivity during saltwater intrusions are analyzed. Results are presented to show that this can increase the degree to which brackish water will penetrate a coastal aquifer. This can also increase the width of the dispersed salt front, and can lead to a much greater circulation of saltwater within the intruding saltwater toe. These results may help to explain field observations that have previously been attributed to “scale-dependent” dispersivity and domain heterogeneity.
Multinomial Probit and Qualitative Choice: A Computationally Efficient Algorithm

Even though multinomial probit models have many attractive theoretical features and have been proposed for diverse choice problems such as modal split and route choice in the transportation field, they have never been used in practice due to the lack of an adequate numerical technique for their application. The purpose of this paper is to introduce such a technique and to demonstrate the feasibility of forecasting with multinominal probit models. Our limited computational experience with the proposed numerical technique indicates that it is accurate, and can be efficiently applied to large choice problems.
A sodium-dependent, fast block to polyspermy occurs in eggs of fucoid algae.

Abstract More than 70% of Pelvetia fastigiata eggs and about 15% of Fucus distichus eggs become polyspermic when fertilized at natural sperm concentrations in a low-sodium (2.5 mM Na+, 450 mM N-methyl glucamine) artificial seawater. Natural levels of polyspermy are 1–3% for both species. Polyspermic eggs germinate and respond to photopolarization, but do not develop beyond an abnormal, “stumpy,” four-cell stage. They die within 1–1.5 weeks. The sodium-dependent block is a fast block, and it is replaced by a second block (probably cell wall formation) no later than 9 min (Pelvetia) after eggs are shed. The sodium-dependent block in Pelvetia is very efficient; when external sodium is raised to only 47.5 mM, the level of polyspermy drops to about 25%. These results are compared with data on marine invertebrates in the context of factors such as the sperm/egg concentration at fertilization and natural, osmotic (salinity) stress.
Genetic counseling and testing for germline p16 mutations in two pancreatic cancer–prone families

Abstract The mortality from pancreatic cancer coincides closely with its incidence, indicating a dismal outlook. Hereditary factors probably account for approximately 5%–10% of the pancreatic cancer burden. The molecular genetic etiology of pancreatic cancer is only beginning to be identified. We describe our genetic counseling experience with 2 large families prone to pancreatic cancer–malignant melanoma in which p16 ( CDKN2 ) germline mutations had been identified. Members of each family underwent intensive counseling before and at the time of disclosure of p16 germline mutation findings. Two non–cancer-affected siblings from each of the 2 families had p16 mutations identified in DNA from their peripheral blood lymphocytes. In each case, a parent affected with pancreatic cancer also harbored the p16 mutation identified in DNA from their respective tumor blocks. The sibling pairs stated that they would seriously consider prophylactic pancreatectomy if biomarkers or imaging findings suggested a precancerous state. Our experience highlights limited options for managing these families and emphasizes the need for better tools to diagnose pancreatic cancer at a curable stage. GASTROENTEROLOGY 2000;119:1756-1760
Volatiles retention during rehumidification of freeze dried food models

Summary Observations of structural collapse during rehumidification of freeze dried substances are used to interpret previously reported data for volatiles loss v. time. The results are in accord with a diffusion-based analysis. At low moisture contents the diffusion coefficient is so low as to give only very small losses, while at high moisture contents it is high enough to give complete loss in a relatively short time. The behaviour at intermediate moisture contents depends upon whether or not there is simultaneous structure collapse. If there is no collapse, volatiles-loss data appear to agree well with a slab-diffusion analysis based upon constant diffusivity and unchanging slab thickness – the average thickness of webs within the porous substance. When there is simultaneous collapse, it is necessary to take into account the continuous increase in web thickness as diffusion occurs. A model is derived based upon a linear increase in web thickness with increasing time, and is shown to agree with experimental data for volatiles loss at intermediate moisture contents in several different systems which show structural collapse.
Some results on functional perturbations to delay-differential systems

Abstract Sonic sufficient criteria for the convergence of the solutions to a class of riclny-differcntial systems with variable coefficients arc presented. Conditions on / guaranteeing asymptotic stability for x(t)≡0 of (1) are presented which provide on explicit region of asymptotic stability.
Assignment of the hypoxia-inducible factor 1α gene to a region of conserved synteny on mouse chromosome 12 and human chromosome 14q

Hypoxia-inducible factor 1 (HIF-1) is a basic helix-loop-helix transcription factor that mediates homeostatic responses to hypoxia. HIF-1 is a heterodimer consisting of HIF-1{alpha} which is encoded by the HIF1A gene, complexes with HIF-1{beta}, which is encoded by the ARNT gene. In this paper we report the assignment of Hif1a and HIF1A to mouse chromosome 12 and human chromosome 14, respectively. HIF1A was assigned to human chromosome 14q21-q24 by analysis of somatic cell hybrids and by fluorescence in situ hybridization. Hif1a was localized by interspecific backcross analysis within a region of mouse chromosome 12 encompassing >30 cM that demonstrates conservation of synteny with a region of human chromosome 14 extending from PAX9 at 14q12-q13 to IGHC at 14q32.33. 12 refs., 2 figs.
BigSecret: A Secure Data Management Framework for Key-Value Stores

Data storage is one of the most popular cloud services, and is therefore offered by most service providers. Among the various cloud based data storage services, key-value stores has emerged as a popular option for storing and retrieving billions of key-value pairs. Although using such cloud based key-value store services could generate many benefits, companies are reluctant to utilize such services due to security concerns. For example, if keys are used to represent social security numbers of health insurance customers, and values are their medical claim details, then outsourcing such key-value pairs to a public cloud could create significant privacy and security risks. To mitigate such risks, we propose BigSecret, a framework that enables secure outsourcing and processing of encrypted data over public key-value stores. Furthermore, our proposed framework could automatically make use of multiple cloud providers, including existing private clouds, to securely distribute data and workloads for improving efficiency and performance. Our experiments show that efficient and secure processing over outsourced encrypted data residing in key-value stores is possible with a minor overhead in most cases. In addition, we show that BigSecret's data and workload distribution algorithm can lead to major performance gains in a multi-cloud setting.
Toward the manipulation of a single spin in an AlGaAs/GaAs single-electron transistor

Single-electron transistors (SETs) are attractive candidates for spin qubits. An AlGaAs/GaAs SET consists of a confined two-dimensional droplet of electrons, called an artificial atom or quantum dot, coupled by tunnel barriers to two conducting leads. Controlling the voltages on the lithographic gates that define the quantum dot allows us to confine a single electron in the dot, as well as to adjust the tunnel barriers to the leads. By applying a magnetic field, we can split the spin-up and spin-down states of the electron by an energy |g|μ B B; the goal is to utilize coherent superpositions of these spin states to construct a qubit. We will discuss our attempts to observe electron spin resonance (ESR) in this system by applying magnetic fields at microwave frequencies. Observation of ESR would demonstrate that we can manipulate a single spin and allow us to measure the decoherence time T 2 *.
Effect of process design on the open-loop behavior of a jacketed exothermic CSTR

Abstract A great deal of research in the chemical engineering literature on steady-state multiplicity analysis, nonlinear dynamics, and chemical process control has been based on the (now) classic two-state continuous stirred tank reactor (CSTR) model. One assumption of this model is that the cooling jacket temperature dynamics are negligible, hence the cooling jacket temperature is the manipulated input for feedback control of reactor temperature. However, since the dynamics of the jacket and reactor are nonlinearly related via energy transfer through the reactor wall this is not in general a very good assumption. The influence of process design parameters on the open-loop behavior of a three-state CSTR model (which incorporates an energy balance around the cooling jacket) is considered in this work. The effect of cooling jacket feed temperature on isola behavior is studied. We show that infeasible reactor operation regions may occur when the reactor is “scaled up”; process operation changes are recommended to move reactor operation back into a feasible region. A multiple time-scale perturbation analysis is used to understand the effect of cooling jacket size on the oscillation amplitude of the three-state CSTR model at a Hopf bifurcation point.
Photobleaching Correction in Fluorescence Correlation Spectroscopy

Fluorescence correlation spectroscopy (FCS) is a fluorescence technique conventionally used to study the kinetics of fluorescent molecules in a dilute solution. Being a non-invasive technique, FCS is now finding wider applications in the study of more complex systems like the dynamics of DNA or proteins in living cells and cell membranes. Unlike an ordinary dye solution, the dynamics of macromolecules like proteins or entangled DNA, in crowded environments is often slow and subdiffusive in nature. This in turn leads to longer residence times of the attached fluorophores in the excitation volume of the microscope. As a result, photobleaching becomes a problem: the number of photons available to calculate the intensity autocorrelation function is limited, and the decay of the fluorescence intensity itself contributes a spurious signal to the autocorrelation function that can easily obscure the signature of the molecular dynamics of interest.We present a method of calculating the intensity autocorrelation function from the arrival times of the photons on the detector that maximizes the information content while correcting for the effect of photobleaching to yield an autocorrelation function that reflects only the underlying dynamics of the sample. For this purpose, we determine the overall photobleaching rate by fitting a multi-exponential decay to the fluorescence intensity. Then we assign a weight to each photon using the reciprocal of this fit function. The autocorrelation function is then calculated from all photon pairs using the product of the individual photon weights. This gives late-arriving fluorescence photons that come from a partially photobleached sample a higher weight than those photons that arrived earlier, compensating for the loss of some of the fluorophores. We demonstrate the utility of this technique by acquiring artifact-free FCS data from entangled DNA solutions and from chromosomal DNA in E. coli.
Exploratory data analysis in the context of data mining and resampling.

Today there are quite a few widespread misconceptions of exploratory data analysis (EDA). One of these misperceptions is that EDA is said to be opposed to statistical modeling. Actually, the essence of EDA is not about putting aside all modeling and preconceptions; rather, researchers are urged not to start the analysis with a strong preconception only, and thus modeling is still legitimate in EDA. In addition, the nature of EDA has been changing due to the emergence of new methods and convergence between EDA and other methodologies, such as data mining and resampling. Therefore, conventional conceptual frameworks of EDA might no longer be capable of coping with this trend. In this article, EDA is introduced in the context of data mining and resampling with an emphasis on three goals: cluster detection, variable selection, and pattern recognition. TwoStep clustering, classification trees, and neural networks, which are powerful techniques to accomplish the preceding goals, respectively, are illustrated with concrete examples.
Structural, electronic, and optical properties of the In 2 O 3 (ZnO) n system

We studied the structural, electronic, and optical properties of the In 2 O 3 (ZnO) n system by a combination of high-resolution electron microscopy, image simulation, and density-functional theory calculation. We found that the In 2 O 3 (ZnO) n system has a polytypoid structure that consists of wurtzite InZn n O n+1 slabs separated by single In-O octahedral layers. These octahedral layers are inversion domain boundaries and satisfy the electronic octet rule. The InZn n O n+1 slabs contain another type of boundary that inverts the polarities again. This boundary prefers a zigzag modulated structure and also obeys the electronic octet rule. We also found that the red-shift in optical transitions for the In 2 O 3 (ZnO) n system as compared to individual In 2 O 3 and ZnO systems is because the symmetry-forbidden band-edge transitions in In 2 O 3 are overcome by the formation of superlattices, with ZnO contributions to the top of the valence band. We further found that increasing n results in an enhanced valence-band maximum in the ZnO region, while the conduction-band minimum becomes more localized on the InO 2 layers, which introduces confinement to electron carriers. Such enhanced localization explains why Zn-rich compounds (higher n) exhibit lower conductivity.
THE EFFECTS OF PHENYLKETONURIC AND OTHER METABOLITES ON SULFATED GALACTOCEREBROSIDE SYNTHESIS IN VIVO AND IN CULTURE

— Sulfated galactocerebroside synthesis was examined in vitro in mouse spinal cord cultures. This system permitted the study of the effects of phenylketonuric metabolites upon synthesis of a specific myelin component, sulfatide, formed early in postnatal development in mice. A significant reduction of Na235SO4 incorporation into myelin sulfatide was observed when spinal cord cultures were grown in the presence of 1000 μm-l-phenylalanine and 500 μm-phenylpyruvate (51 and 700%, respectively). No reduction was observed with β-phenyllactate (300 μm and) phenylacetate (250 μm). Light microscopy indicated that the phenylpyruvate and phenylalanine treated cultures were less extensively myelinated compared to control and β-phenyllactate or phenylacetate treated cultures. The reduction of sulfatide synthesis by phenylpyruvate was shown to be reversible. Intracerebral bilateral injections (8 μg) of l-phenylalanine, phenylpyruvate, α-ketobutyrate, α-ketoisocaproate, α-ketoisovalerate, β-phenyllactate, and phenylacetate in mice 8–15 days old, followed by i.p. administration of radioactive sulfate, resulted in significantly reduced incorporation (all P < 0.05) of sulfate into brain sulfatides with all compounds tested with the exception of β-phenyllactate and phenylacetate. In adult mouse, phenylpyruvate treatment also resulted in a significant decrease in labelling of brain sulfatide. The effects of phenylpyruvate and other metabolites upon pyruvate oxidation in mouse brain homogenates were examined by measuring 14CO2 release from [1-14C]pyruvate. Both phenylpyruvate and α-ketoisocaproate at 1 × 10-3 resulted in a decrease in 14CO2 produced, while phenylacetate and β-phenyllactate had no effect. Sulfate incorporation into sulfatide was reduced by α-ketoisocaproate and phenylpyruvate, and to a lesser extent by phenylalanine, α-ketobutyrate, and α-ketoisovalerate. Phenyllactate and phenylacetate had no effect, either in vivo, or in culture. This order of effectiveness may be related in part to the effects of these compounds on pyruvate oxidation.
An on-road assessment of the impact of cognitive workload on physiological arousal in young adult drivers

In this paper, we describe changes in heart rate and skin conductance that result from an artificial manipulation of driver cognitive workload during an on-road driving study. Cognitive workload was increased systematically through three levels of an auditory delayed digit recall (n-back) task. Results show that changes in heart rate and skin conductance with increasing levels of workload are similar to those observed in an earlier simulation study. Heart rate increased in a step-wise fashion through the first two increases in load and then showed a less marked increase at the highest task level. Skin conductance increased most dramatically during the first level of the cognitive task and then appeared to more rapidly approach a ceiling (leveling) than heart rate. Findings further demonstrate the applicability of physiological indices for detecting changes in driver workload.
Microstructure and Flow Behavior of Fresh Cement Paste

A rheological technique (creep/recovery) was used, in combination with scanning electron microscopy, to study the effects of hydration on both the microstructure and flow properties of fresh cement paste during the induction period, which is the first few hours after cement and water are mixed. The principal hydration product was calcium silicate hydrate (C-S-H), which was first observed in the neck areas between cement particles. At the same time, yield stress increased progressively, which reflected a strengthening of bonds between particles attributed to the C-S-H. Failure strain also increased, which reflected a fundamental change in the nature of that bond. Based on rheological measurements, the activation energy of the hydration process during this time period was estimated to be 5.2 kcal/mol (˜22 kJ/mol).
Object Tracking With a Range Camera for Augmented Reality Assembly Assistance

This paper introduces a 3D object tracking method for an augmented reality (AR) assembly assistance application. The tracking method relies on point clouds; it uses 3D feature descriptors and point cloud matching with the iterative closest points (ICP) algorithm. The feature descriptors identify an object in a point cloud; ICP align a reference object with this point cloud. The challenge is to achieve high fidelity while maintaining camera frame rates. The point cloud and reference object sampling density are one of the key factors to meet this challenge. In this research, three-point sampling methods and two-point cloud search algorithms were compared to assess their fidelity when tracking typical products of mechanical engineering. The results indicate that a uniform sampling maintains the best fidelity at camera frame rates.
Effects of Site Design on Pedestrian Travel in Mixed Use, Medium-Density Environments

Whether high or low incidence of pedestrian travel in mixed-use, medium-density environments is due to site design characteristics, and specifically to presence of direct, continuous, and safe pedestrian systems, is examined. Twelve neighborhood centers or sites in the Puget Sound area of Washington were selected by matching gross residential density, median income, automobile ownership, and intensity and type of neighborhood commercial development. Pedestrians and bicyclists were recorded that traveled into the commercial area. A clear break emerges between urban and suburban sites. The average urban pedestrian volume is 37.7 pedestrians per hour per 1,000 residents, which is 3 times higher than the 12.5 pedestrians per hour per 1,000 residents in suburban sites. These results strongly support the hypothesis that, when holding other variables constant, the urban versus suburban difference in route directness and completeness of pedestrian facilities (namely, block size and sidewalk length) affects pedestrian volumes. The research also questions the common belief that people do not walk in the suburbs. Given appropriate land use conditions, pedestrian facility improvement programs in suburban areas can support pedestrian travel and have a significant influence on mode choice.
Simulation of ceramic particle formation: Comparison with in-situ measurements

Ceramic particle formation processes have been studied using SiO{sub 2} as a model compound. Silica particles have been synthesized in a counterpropagating diffusion flame reactor, in which in-situ measurements of particle size and number density have been made. In addition, the time-temperature history of the particle field has been calculated from a flame simulation. Numerical simulations using moment and sectional methods for particle formation have been applied and compared to the experimental measurements. The simulations for the particle formation assume a kinetically-constrained approach, allowing a simple representation of nucleation, surface growth and coagulation. The results suggest that, if the source rates are known well enough, particle formation of low vapor pressure species can be predicted. Both models do well in predicting the gross features of particle formation (number density and mean particle size), although the moment solution does a poor job of predicting the polydispersity effects during periods of high monomer generation rates.
On the propagation of diel signals in river networks using analytic solutions of flow equations

Abstract. Several authors have reported diel oscillations in streamflow records and have hypothesized that these oscillations are linked to evapotranspiration cycles in the watershed. The timing of oscillations in rivers, however, lags behind those of temperature and evapotranspiration in hillslopes. Two hypotheses have been put forth to explain the magnitude and timing of diel streamflow oscillations during low-flow conditions. The first suggests that delays between the peaks and troughs of streamflow and daily evapotranspiration are due to processes occurring in the soil as water moves toward the channels in the river network. The second posits that they are due to the propagation of the signal through the channels as water makes its way to the outlet of the basin. In this paper, we design and implement a theoretical model to test these hypotheses. We impose a baseflow signal entering the river network and use a linear transport equation to represent flow along the network. We develop analytic streamflow solutions for the case of uniform velocities in space over all river links. We then use our analytic solution to simulate streamflows along a self-similar river network for different flow velocities. Our results show that the amplitude and time delay of the streamflow solution are heavily influenced by transport in the river network. Moreover, our equations show that the geomorphology and topology of the river network play important roles in determining how amplitude and signal delay are reflected in streamflow signals. Finally, we have tested our theoretical formulation in the Dry Creek Experimental Watershed, where oscillations are clearly observed in streamflow records. We find that our solution produces streamflow values and fluctuations that are similar to those observed in the summer of 2011.
Characterization of an Acyltransferase Capable of Synthesizing Benzylbenzoate and Other Volatile Esters in Flowers and Damaged Leaves of Clarkia breweri

A cDNA encoding a protein with 456 amino acids whose sequence shows considerable similarity to plant acyltransferases was identified among 750 Clarkia breweri flower expressed sequence tags. The cDNA was expressed in Escherichia coli, and the protein produced was shown to encode the enzyme benzoyl-coenzyme A (CoA):benzyl alcohol benzoyl transferase (BEBT). BEBT catalyzes the formation of benzylbenzoate, a minor constituent of the C. breweri floral aroma, but it also has activity with a number of other alcohols and acyl CoAs. The BEBT gene is expressed in different parts of the flowers with maximal RNA transcript levels in the stigma, and no expression was observed in the leaves under normal conditions. However, BEBT expression was induced in damaged leaves, reaching a maximum 6 h after damage occurred. We also show here that a closely related tobacco (Nicotiana tabacum) gene previously shown to be induced in leaves after being challenged by phytopathogenic bacteria also has BEBT activity, whereas the most similar protein to BEBT in the Arabidopsis proteome does not use benzoyl CoA as a substrate and instead can use acetyl CoA to catalyze the formation of cis-3-hexen-1-yl acetate, a green-leaf volatile.
Serum 25-Hydroxyvitamin D and Pulmonary Function in Older Disabled Community-Dwelling Women

PULMONARY function declines slowly through adult life and, after age 70 years, is characterized by a more progressive rate of decline (1). Reduced pulmonary function, assessed by forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), is prevalent in older adults and is most commonly associated with chronic obstructive pulmonary disease, asthma, or fibrotic lung disease (2). Pulmonary function is an independent predictor of impaired physical performance (3) and higher all-cause and cardiovascular mortality (4,5). Vitamin D has recently been implicated in lung health (6). Vitamin D deficiency is common among adults (7) and associated with increased risk of osteopenia, osteoporosis, muscle weakness, poor physical performance (8), falls (9), and fractures (10). Vitamin D plays an important role in the regulation of calcium and phosphorus, bone metabolism, cellular differentiation, immune function, and skeletal muscle performance (11,12). Human vitamin D status depends on both sunlight exposure and dietary intake of vitamin D–rich foods, such as oily fish, vitamin D–fortified dairy products, and dietary supplements containing vitamin D. Despite the tremendous progress that has been made in nutrition in the last several decades, vitamin D deficiency remains a serious public health problem (13). Both sunlight exposure and dietary intake of vitamin D are inadequate in many populations (11). More severe vitamin D deficiency can contribute to the development of elevated circulating parathyroid hormone (PTH) concentrations (11). A recent study showed that among adults, aged 20 years or more, who participated in the Third National Health and Nutrition Examination Survey, serum 25-hydroxyvitamin D concentrations were independently associated with pulmonary function (14). Vitamin D deficiency is also common in adults with chronic obstructive pulmonary disease, and the extent of deficiency correlates with the severity of lung disease (15). Vitamin D may influence pulmonary function through effects on the musculoskeletal system (14,15). The relationship between vitamin D status and pulmonary function has not been examined among older women, who are highly susceptible to vitamin D deficiency and worsening airflow limitation with age. We hypothesized that vitamin D deficiency and elevated PTH concentrations were associated with reduced pulmonary function in older women. To address this hypothesis, we measured serum 25-hydroxyvitamin D and PTH concentrations and assessed pulmonary function in a population-based study of older, moderately to severely disabled women living in the community.
A Review of Tidal, Earth Normal Mode and Seismic Data Obtained with Quartz Torsion Accelerometers

Summary A review of broad-band data obtained with quartz torsion accelerometers is presented. Special emphasis is made on the Earth normal mode and seismic frequency regions. Comparison with more conventional instruments is provided where possible.
A fuzzy logic automatic target detection system for LADAR range images

Describes a fuzzy logic system that performs end-to-end automatic target detection for LADAR imagery. Images are preprocessed with nonlinear fuzzy filters to remove noise. Several target detectors employing fuzzy and robust statistical methods are used to create pixel-based target confidence values that are fused with the Choquet fuzzy integral. Thresholds are determined from ROC curve analysis on a training set and then the detectors are run on a test set. Features are extracted from detected target windows and final target detection is performed by a neural network. Results on the training and test set are analyzed.
Pigment epithelium-derived factor supports normal Müller cell development and glutamine synthetase expression after removal of the retinal pigment epithelium

In conditions in which the retinal pigment epithelium (RPE) is dystrophic, carries a genetic mutation, or is removed physically, Muller cells undergo degenerative changes that contribute to the retinal pathology. We previously demonstrated that pigment epithelium-derived factor (PEDF), a glycoprotein secreted by the RPE cells with neuroprotective and differentiation properties, protects against photoreceptor degeneration induced by RPE removal. The purpose of the present study was to analyze the putative gliosupportive activity of PEDF on Muller cells of RPE-deprived retinas and assess whether protection of Muller cells was correlated with improved photoreceptor outer segment assembly. Eyes were dissected from Xenopus laevis tadpoles, and the RPE was removed before culturing in medium containing purified PEDF, PEDF plus anti-PEDF, or medium alone. Control eyes matured with an adherent RPE or in medium containing PEDF plus nonimmune serum. Muller cell ultrastructure was examined. Glial fibrillary acidic protein (GFAP) and glutamine synthetase were localized immunocytochemically, and the corresponding protein levels were quantified. In control retinas, Muller cells were structurally intact and formed adherens junctions with neighboring photoreceptors. In addition, they did not express GFAP, whereas glutamine synthetase expression was high. RPE removal dramatically altered the ultrastructure and biosynthetic activity of Muller cells; Muller cells failed to form adherens junctions with photoreceptors and glutamine synthetase expression was suppressed. PEDF prevented the degenerative glial response; Muller cells were ultrastructurally normal and formed junctional complexes with photoreceptors. PEDF also preserved the expression of glutamine synthetase at near-normal levels. The morphogenetic effects of PEDF were blocked by the anti-PEDF antibody. Our study documents the glioprotective effects of PEDF and suggests that maintenance of the proper Muller cell ultrastructure and expression of glutamine synthetase may be necessary to support the proper assembly of photoreceptor outer segments.