cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatially Resolved Non-Contact Surface Photovoltage In Semiconductors

The early work of Brattain and Bardeen demonstrated that under illumination, a semi-conductor surface develops a potential which can be measured with non-contact capacitive coupling. Since then, the surface photo-voltage (PV) effect has received sporadic experimental as well as theoretical considerations. A number of experiments have been reported (with and without contacts) which make use of both DC and AC surface PV. In the latter form, the incident light is modulated at frequencies ranging from a few Hz to a few MHz. Both the DC and AC embodiments of the surface photo-voltage effect have been used to study various minority and majority carrier transport mechanisms in the presence of various degrees of inversion (or accumulation) of the semiconductor surface. Theoretical treatment of the PV effect has also been sporadic and lacking in completeness. Existing models for the PV effect are either too simplified to accurately represent a physical semiconductor surface, or are too general to be useful for the interpretation of experimental data. It is nevertheless clear from theoretical considerations and from existing experimental results (using incident photon energies above and below the semiconductor bandgap) that the PV effect contains valuable quantitative information which is specific to the space charge region of a semiconductor surface or junction. It is the object of this paper to demonstrate that the PV effect affords the opportunity to quantitatively measure many of the technologically important properties of a semicon-ductor surface or junction without contacting the sample and with a spatial resolution that is consistent with very large scale integration (VLSI) technology. It is also shown that non-contact PV is very sensitive to junction bias and can therefore be used to detect the on-off state of an operating transistor.
GUS, a frame driven dialog system

GUS is the first of a series of experimental computer systems that we intend to construct as part of a program of research on language understanding. In large measure, these systems will fill the role of periodic progress reports, summarizing what we have learned, assessing the mutual coherence of the various lines of investigation we have been following, and suggesting where more emphasis is needed in future work. GUS (Genial Understander System) is intended to engage a sympathetic and highly cooperative human in an English dialog, directed towards a specific goal within a very restricted domain of discourse. As a starting point, GUS was restricted to the role of a travel agent in a conversation with a client who wants to make a simple return trip to a single city in California. There is good reason for restricting the domain of discourse for a computer system which is to engage in an English dialog. Specializing the subject matter that the system can talk about permits it to achieve some measure of realism without encompassing all the possibilities of human knowledge or of the English language. It also provides the user with specific motivation for participating in the conversation, thus narrowing the range of expectations that GUS must have about the user's purposes. A system restricted in this way will be more able to guide the conversation within the boundaries of its competence.
3D mapping of visual attention for smart rehabilitation

The estimation of human attention as input modality has been suggested as a method for an advanced human-computer interaction. With an increasing interest and development of augmented reality tools, the advent of Microsoft HoloLens glasses and increasingly affordable wearable eye-tracking devices, monitoring the human attention will soon become ubiquitous. Also visual heat-maps have become very popular and simpler to create in the 2D space over the last few years. They are very compelling and can be effective in summarizing and communicating data. The innovation in our work is the implementation of visual 3D heat-maps of the real world combined with advanced Computer Vision libraries. Finally, we have incorporated the visual 3D heat-maps for rehabilitation purposes that deal with the loss of concentration in children with learning disabilities, or disabled patients to select items of interest for them across a room.
In vivo changes of cellulose, trehalose and glycogen during differentiation of Dictyostelium discoideum

Abstract Changes in the concentration of three major carbohydrates, e.g., glycogen, trehalose, and cellulose, were determined during differentiation of Dictyostelium discoideum in a stage study. These three carbohydrates consituted 50–63% of the total carbohydrates. Total carbohydrate content per cell aliquot did not change between the aggregation and sorocarp stages of differentiation. The isolation, purification, and characterization of cellulose is described. Cellulose consisted of an alkali-insoluble (alpha) and an alkali-soluble (beta) fraction. Total cellulose accumulated from very low amounts in late pseudoplasmodium cells to about 35% of carbohydrates in mature sorocarps at a rate of 0.07 μmole glucose equiv/min/ml packed cell volume. Purified alkali-insoluble cellulose constituted about 19% of total carbohydrates in mature sorocarps and accumulated at a rate of 0.035 μmole glucose equiv/min/ml packed cell volume. Trehalose constituted 10–11% of the carbohydrates in sorocarps and accumulated at a rate of 0.035 μmole glucose equiv/min/ml packed cell volume. Glycogen, comparing several methods of determination, was rapidly degraded between the culmination and sorocarp stages of differentiation at an average rate of 0.05 μmole glucose equiv/min/ml packed cell volume. The major portion of glycogen was soluble in TCA and constituted 35% of total carbohydrates in aggregated cells and about 11% in mature sorocarps. A minor fraction of glycogen, about 15% of total carbohydrates in aggregated cells, was solubilized by KOH from a TCA precipitate. A mild acidic treatment of solubilized cell constituents increased the glycogen content by 55%, as judged by an enzymatic assay.
Cytochrome c turnover in skeletal muscle.

Summary The half-life of skeletal muscle cytochrome c has previously been found, by the use of [ 14 C]delta-aminolevulinate, to be approximately 30 days. This turnover value has been re-evaluated by a procedure that does not involve tracer techniques. Transition curves of an approach to steady-state cytochrome c concentrations were determined during: 1) a return from elevated levels following cessation of exercise training, and 2) the decline in cytochrome c following thyroidectomy. The half-lives obtained, 8.1 days and 10.7 days respectively, indicate that this mitochondrial component of skeletal muscle turns over at rates very similar to liver and cardiac muscle.
No material benefits, and a fertilization cost, for multiple mating by female leaf beetles

When females mate multiple times it presents an intriguing problem for evolutionary biologists due to the high costs and not very apparent benefits. Yet, this behaviour must have higher benefits than costs to be maintained by natural selection. We studied possible benefits for multiple mating by female leaf beetles, Leptinotarsa decemlineata, both with multiple males (polyandry) and multiple times with the same male (repeated matings). For polyandry, we tested the material benefits hypothesis, as well as fertility insurance, by mating females to varying numbers of males and looking at sperm received and fecundity. Although there was a relationship between amount of stored sperm and number of matings, we did not find the predicted positive relationship between fecundity and number of matings. Thus, the material benefits hypothesis was not supported. For repeated matings, we tested the sperm and nonsperm material benefit hypotheses by mating females to a single male varying numbers of times on one mount. For this set of tests neither sperm number nor fecundity was positively correlated with number of matings, therefore neither hypothesis was supported. Interestingly, in both experiments, there was a significant decrease in hatch rate with an increase in matings, demonstrating a cost of polyandry. These findings, along with previous research, suggest a cost of multiple mating with a possible role of seminal fluids in the reduction in female fecundity.
Precise determination of melting and boiling points by differential thermal analysis and differential scanning calorimetry

Abstract The theory, operation and instrumentation of differential thermal analysis (DTA) and differential scanning calorimetry (DSC) are sufficiently well developed to determine melting and boiling points with a high degree of certainty and reproducibility. However, certain precautions must be taken if data of maximum value are to be obtained. Sampling techniques, encapsulation, instrumental parameters and theoretical considerations will be treated in detail. In addition to the very small amount of material required for a melting or boiling point determination, DTA and DSC have other advantages. If certain precautions are observed it is possible to use several equations from classical thermodynamics to obtain absolute purity. A complete Cox Chart of a pure liquid can be obtained and the heat of vaporization determined in a few hours. Complex solid phase diagrams are easily studied. The success or failure of fractionation techniques can be predicted from single thermograms if several phase transitions are present.
Does preincubation with prostaglandin e1 or prostaglandin e2 enhance oxytocin-induced myometrial contractility in vitro?

Objective To determine if preincubation with prostaglandin E1 (PGE1) and E2 (PGE2) enhances oxytocin-induced myometrial contractility in vitro. Study Design Myometrial strips from 13 women were incubated with PGE1 (10 −5 mol/L or 10 −6 mol/L), PGE2 (10 −5 mol/L or 10 −6 mol/L) or solvent before adding cumulative concentrations of oxytocin (10 −10 to 10 −6 mol/L). The area under the contraction curve was calculated after addition of each agent. One- and two-way analysis of variance was used for comparison (significance p Results PGE2 10 −5 mol/L reduced response to oxytocin 10 −9 to 10 −6 mol/L ( p p −8 mol/L (10 −5 mol/L > 10 −6 mol/L; p Conclusion Contrary to the hypothesis, neither PGE1 nor PGE2 enhanced oxytocin-induced myometrial contractility; in fact, PGE2 decreased contractility.
Propagating phase interface with intermediate interfacial phase: Phase field approach

An advanced three-phase phase field approach (PFA) is suggested for a nonequilibrium phase interface that contains an intermediate phase, in particular, a solid-solid interface with a nanometer-sized intermediate melt (IM). A thermodynamic potential in the polar order parameters is developed that satisfies all thermodynamic equilibrium and stability conditions. The special form of the gradient energy allowed us to include the interaction of two solid-melt interfaces via an intermediate melt and obtain a well-posed problem and mesh-independent solutions. It is proved that for stationary 1D solutions to two Ginzburg-Landau equations for three phases, the local energy at each point is equal to the gradient energy. Simulations are performed for $\ensuremath{\beta}\ensuremath{\leftrightarrow}\ensuremath{\delta}$ phase transformations (PTs) via IM in an HMX energetic material. The obtained energy IM width dependence is described by generalized force-balance models for short- and long-range interaction forces between interfaces but not far from the melting temperature. A force-balance model is developed that describes phase field results even 100 K below the melting temperature. The effects of the ratios of width and energies of solid-solid and solid-melt interfaces, temperature, and the parameter characterizing interaction of two solid-melt interfaces, on the structure, width, energy of the IM and interface velocity are determined by finite element method. Depending on parameters, the IM may appear by continuous or discontinuous barrierless disordering or via critical nucleus due to thermal fluctuations. The IM may appear during heating and persist during cooling at temperatures well below than it follows from sharp-interface approach. On the other hand, for some parameters when IM is expected, it does not form, producing an IM-free gap. The developed PFA represents a quite general three-phase model and can be extended to other physical phenomena, such as martensitic PTs, surface-induced premelting and PTs, premelting/disordering at grain boundaries, and developing corresponding interfacial phase diagrams.
Polypropylene Surface Modification by Entrapment Functionalization

A new approach to prepare surface-functionalized polypropylene using block cooligomers of propylene and acrylate esters is described. Using boron-promoted radical polymerization and a vinyl-terminated polypropylene oligomer, block cooligomers of propylene and tert-butyl acrylate were prepared. Codissolution of such cooligomers with excess isotactic polypropylene and film casting produced functionalized films. Acidolysis of the tert-butyl esters at the surface of these films produced a poly(acrylic acid)-grafted polypropylene film that could be further modified chemically. Incorporation of pH-sensitive dyes into this poly(acrylic acid) surface in turn produced films whose reactivity in proton-transfer chemistry in various solvent suspensions was studied as a function of solvent.
Lysophosphatidic acid prevents apoptosis of Caco-2 colon cancer cells via activation of mitogen-activated protein kinase and phosphorylation of Bad.

Lysophosphatidic acids (LPA) exert growth factor-like effects through specific G protein-coupled receptors. The presence of different LPA receptors often determines the specific signaling mechanisms and the physiological consequences of LPA in different environments. Among the four members of the LPA receptor family, LPA2 has been shown to be overexpressed in colon cancer suggesting that the signaling by LPA2 may potentiate growth and survival of tumor cells. In this study, we examined the effect of LPA on survival of colon cancer cells using Caco-2 cells as a cell model system. LPA rescued Caco-2 cells from apoptosis elicited by the chemotherapeutic drug, etoposide. This protection was accompanied by abrogation of etoposide-induced stimulation of caspase activity via a mechanism dependent on Erk and PI3K. In contrast, perturbation of cellular signaling mediated by the LPA2 receptor by knockdown of a scaffold protein NHERF2 abrogated the protective effect of LPA. Etoposide decreased the expression of Bcl-2, which was reversed by LPA. Etoposide decreased the phosphorylation level of the proapoptotic protein Bad in an Erk-dependent manner, without changing Bad expression. We further show that LPA treatment resulted in delayed activation of Erk. These results indicate that LPA protects Caco-2 cells from apoptotic insult by a mechanism involving Erk, Bad, and Bcl-2.
Compound semiconductors for low-noise microwave MESFET applications

In order to determine the low-noise potential of microwave MESFET's fabricated from materials other than GaAs, a one-dimensional FET model is employed. From material parameters and device geometry the model enables the calculation of a small-signal equivalent circuit from which performance information is acquired. Material parameters, as predicted from Monte Carlo calculations, are used to simulate 1-µm devices fabricated from GaAs as well as InP, Ga 0.47 In 0.53 As, InP 0.8 As 0.2 , Ga 0.27 In 0.73 P 0.4 As 0.6 , and Ga 0.5 In 0.5 As 0.96 Sb 0.04 . Results obtained from simulations comparing a Ga 0.5 In 0.5 As 0.96 - Sb 0.04 device to an equivalent GaAs device indicate that a decrease in minimum noise figure of almost a factor of two is possible. Considerable improvement in noise performance over a GaAs device is also predicted for devices fabricated from Ga 0.47 In 0.53 As and Ga 0.27 In 0.73 P 0.4 As 0.6 . In addition, the quaternary and ternary devices as well as the InP device should exhibit superior gain and high-frequency performance compared to GaAs devices.
Trypanosoma brucei: two-dimensional gel analysis of the major glycosomal proteins during the life cycle.

Abstract Kinetoplastid organisms possess a unique organelle, the glycosome, which compartmentalizes the Embden-Meyerhof segment of glycolysis and several other metabolic pathways. In Trypanosoma brucei many of the enzyme activities localized to the glycosome are stage regulated. Two-dimensional gel analysis was used to examine the characteristics, expression, and biosynthesis of the major glycosomal proteins. Two-dimensional gel maps of glycosomes from slender bloodforms and late intermediatestumpy bloodforms (the precursors of procyclic forms) were indistinguishable, while those of procyclic form glycosomes showed extensive differences. Glycosomal phosphoenolpyruvate carboxykinase and malate dehydrogenase were identified to have subunit molecular weights of 60 and 34 kDa, respectively. We detected two hitherto undescribed glycosomal proteins, one of which is found only in bloodforms. All of the major proteins, except glucose phosphate isomerase, were highly basic. Stage regulation of glycosomal enzyme activities correlated with stage regulation of specific protein biosynthesis.
Infections of parotid gland

Abstract 1. 1. Review of current literature has been given presenting theories of the etiology of infections of the parotid gland. 2. 2. Experimental proof together with clinical reports have been given showing that hematogenous infection of the parotid while uncommon does occur. It has also been shown that the two types of infection can be differentiated by clinical observation. 3. 3. Further reports have been given on the use of dilatation of Stenson's duct in infections of the parotid of the ascending type. 4. 4. Description of our technique in making sialograms has been given. 5. 5. Sialograms of normal and abnormal glands including tumors have been shown accompanied by drawings representing the detail of the glands which is only seen on the original negative. We feel that further studies along the lines suggested is necessary before settling the questions involved in this paper. We also urge that further studies of sialograms which are published be accompanied by illustrations so that sufficient criteria be available to the reader for making definite diagnosis in those cases.
Characterization of the non-Newtonian flow behavior of drag-reducing fluids

Abstract The steady streaming flow induced by a cylinder oscillating in a fluid otherwise at rest has been employed to characterize the rheological properties of drag-reducing fluids. Flow reversal and several features common with turbulence make this flow on alternative to conventional viscometric measurements, which do not provide adequate information at very low polymer concentrations. Relevant fluid relaxation times are determined by measuring the steady secondary velocity profiles and then fitting theoretical predictions to the data. Laser Doppler velocimetry has been used to measure steady streaming velocities of well-characterized solutions of polyacrylamide, polyethylene oxide, and a surfactant mixture. Results show that the effective fluid elasticity, or relaxation time, increases with concentration or with frequency of oscillation of the primary flow. Furthermore, the relaxation time appropriate for characterizing steady streaming has been found to be far smaller than the longest relaxation time obtained from viscometric flows. The sensitivity to frequency is important, especially when associating a relaxation time with drag-reducing capability. A comparison with drag-reduction experiments suggests that ranking additives according to elasticity provides information about drag-reducing effectiveness. Steady streaming is proposed as a useful tool for characterizing the response of polymers and surfactants in a variety of unsteady nonviscometric flows.
Editorial: protecting and sustaining indigenous people’s traditional environmental knowledge and cultural practice

As applied to the circumstances faced by particular indigenous communities—from theYorta Yorta of Australia to the Bhotiya of Nepal—and to indigenous communities aroundthe world, the ﬁve intellectual tasks of the policy sciences enable the authors in this specialissue to clarify the values and goals of the participants, and whether and how they relate tothe protection of human dignity, as a critical ﬁrst step toward developing an effectivestrategy to combat an evident wrong. This initial inquiry raises what Lasswell termed the‘‘historical question’’ (1963, 2), and so each analysis in this issue was informed by anexamination of the events and conditioning factors over time in relation to the realizationof the goals identiﬁed. In the light of this ‘‘trend and factor knowledge’’ (Lasswell 1963, 2),the authors have been able to explore the ways in which future developments might unfoldand policy alternatives can be devised. Each contributor to this special issue has thusaddressed an aspect of the question of the role of indigenous peoples’ knowledge andpractices for a range of outcomes including poverty alleviation for indigenous peoples andthe sustainable management of biodiversity, among others. The intention is to raiseimportant questions on juxtaposing human rights with the collaborative development ofculturally sensitive strategies through which indigenous peoples may move closer to therealization of sustainable self-determination and human dignity.For millennia, the Earth’s geophysical environment has co-evolved with the biosphere,resulting in a diversity of uniquely adapted species and systems, and ultimately fosteringhuman civilization. The twentieth century saw the emergence of human beings as thedominant catalyst of change in the earth system—by almost any measure we have begun a
SOA and Web Services

This tutorial presents the foundational knowledge for the researchers and practitioners on Service- Oriented Architecture (SOA) and Web services. The traditional ?triangle? SOA and variations that better support SOA services and solutions will be examined. Critical Web services infrastructures will be covered, such as WSDL, BPEL, WSRF, Discovery, Composition, Registry, and Web services invocation and relationship binding. How Web 2.0 and SOA can benefit with each other will also be explored. An IEEE SOA Solution Reference Architecture standardization initiative will be introduced in this tutorial to illustrate how different pieces of technology components can be used to build reusable, flexible, and extensible SOA solutions. Finally, the presenter will depict research and development challenges and directions in the field of SOA and Web services. The target audiences are all-level researchers, practitioners, and students. This tutorial material is created for the IEEE Body of Knowledge initiative on Services Computing, which is sponsored by the IEEE Computer Society Technical Committee on Services Computing.
Workshop - tablet PCs in engineering education & research

Tablet PCs are one of the newest innovations in computing and communications tools, offering an opportunity to positively impact the way in which students and faculty use technology to support teaching and learning. In this three hour workshop faculty will receive a hands-on introduction to the use of several tablet-based software tools including OneNote, Classroom Presenter, WriteOn, ChemPad, VectorPad and Math Journal. We will provide sufficient instruction for faculty to have a basic competency with the technology. Most importantly, we will show faculty various pedagogical practices that we have found helpful in using these technology tools in the classroom over the past three years. Active learning exercises for various disciplines will be emphasized. Faculty will be tasked with developing short active learning exercises starting from the development of goals for the exercise, through the desired student interaction, and ending with the exercise assessment and improvement strategy. Assessment processes will be discussed so that future practitioners can better understand how to measure the effectiveness of the use of technology tools.
Life-cycle cost optimal design of passive dissipative devices

The cost-effective performance of structures under natural hazards such as earthquakes and hurricanes has long been recognized to be an important topic in the design of civil engineering systems. A realistic comprehensive treatment of such a design requires proper integration of (i) methodologies for treating the uncertainties related to natural hazards and to the structural behavior over the entire life-cycle of the building, (ii) tools for evaluating the performance using socioeconomic criteria, as well as (iii) algorithms appropriate for stochastic analysis and optimization. A systematic probabilistic framework is presented here for detailed estimation and optimization of the life-cycle cost of engineering systems. This framework is a general one but the application of interest here is the design of passive dissipative devices for seismic risk mitigation. A comprehensive methodology is initially presented for earthquake loss estimation; this methodology uses the nonlinear time-history response of the structure under a given excitation to estimate the damage in a detailed, component level. A realistic probabilistic model is then presented for describing the ground motion time history for future earthquake excitations. In this setting, the life-cycle cost is uncertain and can be quantified by its expected value over the space of the uncertain parameters for the structural and excitation models. Because of the complexity of these models, calculation of this expected value is performed using stochastic simulation techniques. This approach, though, involves an unavoidable estimation error and significant computational cost, features which make efficient design optimization challenging. A highly efficient framework, consisting of two stages, is discussed for this stochastic optimization. An illustrative example is presented that shows the efficiency of the proposed methodology; it considers the seismic retrofitting of a four-story non-ductile reinforced-concrete building with viscous dampers.
Measuring the Precision of Statistical Cost Allocations

This article examines the use of regression analysis for allocating indirect costs. When multiple regression is used to estimate the weights of several allocation factors, conventional standard errors and correlation coefficients can be misleading with respect to the statistical precision of the cost allocations. This article develops alternative allocation approaches and measures of precision that use linear prediction theory and Bayesian inference. The proposed methods are illustrated using a university indirect cost study.
Sensitivity of High-Frequency RF Circuits to Total Ionizing Dose Degradation

The combined effects of TID, process corner, and temperature on the performance of high frequency RF circuits are presented. TID experiments at 25°C and 100°C on NMOSFETs and PMOSFETs fabricated in a commercial 45 nm technology show varied degradation in DC and RF performance. The combination of variation due to TID, process, and temperature causes the NMOSFET parameters to fall out of the pre-irradiation process/voltage/temperature (PVT) operating space. TID-aware compact models of MOSFETs are developed based on measured parametric degradation of the transistor behavior. The compact models are used to design a K-band LC voltage-controlled oscillator (VCO), operating at 22 GHz without any compensation circuitry. Circuit simulations show that a 500 krad(SiO2) dose on the VCO operating at 100°C and at the slow process corner can result in circuit failure for biases less than 500 mV. For higher biases, TID causes degradation in frequency, amplitude, and phase noise, causing inability of the VCO to meet the desired performance specifications.
Failure of fiber composites: A lattice Green function model

A new powerful numerical technique for investigating the failure of fiber reinforced composites is presented. The technique utilizes 3D lattice Green's functions to calculate load transfer from broken to unbroken fibers, and also includes the important effects of fiber/matrix sliding. The inherent flexibility of the technique in adjusting the spatial extent of load transfer allows for the study of many aspects of real composite failure processes which have been unobtainable to date. Using this technique, composite reliability, the influence of manufacturing defects on performance, and the overall optimization of composite performance can all be investigated in detail. Initial results using this approach show that load transfer and the existence of spatially-staggered fiber breaks play an important role in determining strength and toughness of composites. Furthermore, the critical configurations of fiber breaks that initiate catastrophic failure are complicated 3D objects and any single spatial plane is composed mainly of sliding fibers rather than broken fibers, with a few strong fibers intact within the critical defect.
Boundary layer intrusions from a sloping bottom: A mechanism for generating intermediate nepheloid layers

[1] Laboratory experiments were used to investigate the growth of intrusions due to internal-wave reflection from a sloping boundary. When normalized by the incident energy density flux, the average intrusion spreading velocity was found to be a linear function of the frequency ratio ω/ωc, where ω is the frequency of the incident wave and ωc is the critical frequency, at which the wave characteristic has the same angle as the bottom slope. Evenly spaced layers, indicating thin perturbations in the background density gradient, developed within the mixing region and spread into the tank interior. The vertical spacing of these layers also bore a linear relationship to ω/ωc. A linear model of internal-wave reflection suggests that these layers may be related to an isopycnal displacement, or overturn, scale. Intrusion growth occurred at a range around the critical frequency and was strongest at slightly supercritical conditions. A balance relating the spreading rate of intrusions to the divergence of energy density flux across the boundary layer is derived. Fitting the laboratory results to this theoretical prediction suggested a weak net buoyancy flux. This balance might be of use in predicting spreading rates of intermediate nepheloid layers generated by internal-wave mixing at oceanic margins.
Evaluation of a Rural-Based Early Intervention Personnel Preparation Project:

To meet the critical need for early intervention/early childhood special education (EI/ECSE) personnel in rural areas, the Rural Early Intervention Training Project was developed. The content of this program was designed to assist students in developing competencies in 8 areas, with an emphasis on practicum activities in the rural locale. University professors traveled to a designated rural community to conduct coursework each month, and a practicum supervisor observed students bi-monthly. Project evaluation results suggested student acquisition of intervention skills and high student satisfaction with coursework, supervisors, and instructors. In addition, results on the Early Intervention Self-Rating Instrument (Ryan-Vincek & Losardo, 1987) reflected a significant positive linear trend in students' self-ratings for 14 of 16 ratings.
Localization of charged excitations in polyaniline

Abstract Photogenerated polarons in the emeraldine base form of polyaniline have been extensively studied by using the infrared and optical photoexcitation, photoconductivity, and light-induced electron spin resonance (LESR) techniques. The photogenerated polarons in polyaniline are strongly localized and stable for the experimental time scales (≥ 1 msec.) at both 2.0 eV and 4.0 eV optical pumping energies as proved by infrared and LESR studies. The dynamic mass of the charged excitations in polyaniline is found to be two orders of magnitude larger than the electron band mass. Steady state photoconductivity measurements demonstrate that the photogenerated charges are highly immobile for both 2.0 eV and 4.0 eV pumping, consistent with the infrared studies. Significantly different results were obtained in the fast time scale (≤ 800 psec.) photoconductivity measurements. Photoexcitation at 4.0 eV leads to a measured photoconductivity one order of magnitude less than that of other conjugated polymers. The 2.0 eV optical pumping yields a factor of 30 smaller photoconductivity than that of the 4.0 eV pumping for equal number of incident photons. We propose that photogenerated holes are responsible for the transport, and the photogenerated electrons are mainly localized on the benzene ring (as monitored by the softening of the ring deformation mode caused by losing the aromaticity of the benzenoid structure).
Propagation of a nonlinear seismic pulse in an anelastic homogeneous medium

Seismic surveys are often conducted using dynamite charges buried near the surface in unconsolidated material. In such material a large zone near the source should exist wherein nonlinear anelastic wave propagation, can be expected to take place, and have a significant impact on the way in which a seismic pulse forms and how its energy gets distributed into the surrounding medium. To obtain a solution for a propagating pulse in this zone, the equations of motion for nonlinear anelastic wave propagation, good to second order in the displacements, are solved numerically for the problem of a Gaussian pressure pulse acting on the interior cavity of a cylindrically symmetric hole in the medium. An implicit finite‐difference algorithm is used for the solution to the equations of motion for this problem. The anelastic medium is characterized by multivalued stress‐strain relations that exhibit hysteresis, and therefore a loss of energy per cycle, corresponding to a medium with a constant Q factor. Several numeric...
β-galactoside transport in E. coli : a functional dissection of lac permease

The polytopic membrane protein lac permease harnesses energy from the electrochemical H+ gradient to transport beta-galactosidases against a concentration gradient. Although high-resolution structural information is still lacking, the permease is thought to possess 12 membrane-spanning alpha-helical segments. Various experimental strategies, including site-directed mutagenesis, have been employed to probe the function of this membrane protein at the molecular level.
Plasticizer Types and Coating Methods Affect Quality and Shelf Life of Eggs Coated with Chitosan

Effects of different plasticizer types (glycerol, propylene glycol, and sorbitol) and coating methods (brushing, dipping, and spraying) on the internal quality and shelf life of chitosan-coated eggs were evaluated during 5 wk of storage at 25 degrees C. The Haugh unit and yolk index values suggested that chitosan coating, irrespective of the plasticizer types, extended the shelf life of eggs by almost 3 wk at 25 degrees C compared with noncoated eggs. After 5 wk of storage, plasticizer types did not significantly affect the quality (weight loss, Haugh unit, and yolk index) of chitosan-coated eggs. However, there was an observable trend indicating that use of sorbitol rather than propylene glycol and glycerol as a plasticizer was better in reducing weight loss (whole egg) of chitosan-coated eggs during a 5-wk storage. After a 5-wk storage, there were no significant differences in weight loss and weight of albumen and yolk among chitosan-coated eggs, regardless of the coating methods. However, both brushing and dipping methods yielded chitosan-coated eggs with better yolk (higher yolk index values) and albumen (lower pH) qualities than did the spraying method. During 3 to 5 wk of storage, the Haugh unit values of chitosan-coated eggs by the brushing method were higher than or comparable to those by dipping or spraying. Therefore, coating of eggs with chitosan using sorbitol as a plasticizer and by the brushing method may offer a protective barrier in preserving the internal quality and thus extending shelf life of eggs.
On the reliability of a multicomponent series system

Consider a series system consisting of several independent components where the components are assumed to have exponential distributions with unknown and possibly unequal failure rates. The objective here is to infer about the reliability of the whole system at a given time t based on independent samples from each component. In this article, we first consider testing a hypothesis on the reliability of the whole system against a suitable alternative and try to follow the likelihood ratio (LR) method. However, closed expressions for the maximum likelihood estimators (MLEs) of the model parameters are not available under the null (alternative) hypothesis, which hinders the development of the traditional LR test method. To avoid this problem, we have found approximate MLEs of the model parameters under the null (and alternative) hypothesis, which are then used to derive an approximate likelihood ratio (ALR) statistic. Using the ALR statistic, we then find a conditional test procedure whose cut-off point can b...
An unusually large zero-field splitting in the molecule xanthione

Abstract An unusually large zero-field splitting of the lowest triplet state has been observed directly in the phosphorescence spectrum of the xanthione molecule in a xanthone host crystal. There are two xanthione guest sites in the host crystal. In one of the sites the zero-field parameter D is −11 cm −1 and in the other it is −20 cm −1 . These results have been confirmed by measurements of the Zeeman splittings. It is argued that the large D values are due to spin-orbit coupling.
Azaindole hydroxamic acids are potent HIV-1 integrase inhibitors.

HIV-1 integrase (IN) is one of three enzymes encoded by the HIV genome and is essential for viral replication. Recently, HIV-1 IN inhibitors have emerged as a new promising class of therapeutics. Herein, we report the discovery of azaindole carboxylic acids and azaindole hydroxamic acids as potent inhibitors of the HIV-1 IN enzyme and their structure−activity relationships. Several 4-fluorobenzyl substituted azaindole hydroxamic acids showed potent antiviral activities in cell-based assays and offered a structurally simple scaffold for the development of novel HIV-1 IN inhibitors.
Mn-doping effect on dielectric and electromechanical losses in the system Pb(ZrxTi1−x)O3–Pb(Zn1/3Nb2/3)O3

Dielectric and electromechanical losses play a critical role in the performance of the transducer in high power conditions. In this study, we report a systematic study on the effect of Mn-doping on the losses in the Pb(ZrxTi1−x)O3–Pb(Zn1/3Nb2/3)O3 (PZT–PZN) system. Two types of sintering conditions were employed to synthesize ceramics with varying grain sizes. The Zr/Ti ratio in the PZT system was fixed at 52/48 corresponding to morphotropic phase boundary (MPB) and Mn concentration was varied from 0 to 0.9 wt%. The results show that the composition 0.9PZT–0.1PZN + 0.5 wt% Mn provides optimized magnitude for the dielectric, piezoelectric, and loss properties.
The effect of salts on the binding of α-bungarotoxin in the brain of the horseshoe crab, limulus polyphemus

1. The binding of 125I-labelled α-bungarotoxin in the brain of the horseshoe crab, Limulus polyphemus, has been investigated in Chao's, a physiological salt solution. 2. Toxin binding was inhibited by the salts in Chao's solution. 3. Inhibition was due to a decrease in the rate of association of toxin and was attributed to the metal cations. 4. At the concentrations at which they occur in Chao's, NaCl, CaCl2 and KCl produced 84, 61 and 25% inhibition of α-bungarotoxin binding, respectively. 5. The inhibition of binding by NaCl was concentration-dependent with an I50 of 0.12 M. 6. The pharmacological specificity of toxin binding was unaffected by salts. At a concentration of 10−5 M, d-tubocurarine inhibited binding by 84%, and nicotine at the same concentration produced 75% inhibition.
Relative performance of gene- and pathway-level methods as secondary analyses for genome-wide association studies

Despite the success of genome-wide association studies (GWAS), there still remains “missing heritability” for many traits. One contributing factor may be the result of examining one marker at a time as opposed to a group of markers that are biologically meaningful in aggregate. To address this problem, a variety of gene- and pathway-level methods have been developed to identify putative biologically relevant associations. A simulation was conducted to systematically assess the performance of these methods. Using genetic data from 4,500 individuals in the Wellcome Trust Case Control Consortium (WTCCC), case–control status was simulated based on an additive polygenic model. We evaluated gene-level methods based on their sensitivity, specificity, and proportion of false positives. Pathway-level methods were evaluated on the relationship between proportion of causal genes within the pathway and the strength of association. The gene-level methods had low sensitivity (20-63%), high specificity (89-100%), and low proportion of false positives (0.1-6%). The gene-level program VEGAS using only the top 10% of associated single nucleotide polymorphisms (SNPs) within the gene had the highest sensitivity (28.6%) with less than 1% false positives. The performance of the pathway-level methods depended on their reliance upon asymptotic distributions or if significance was estimated in a competitive manner. The pathway-level programs GenGen, GSA-SNP and MAGENTA had the best performance while accounting for potential confounders. Novel genes and pathways can be identified using the gene and pathway-level methods. These methods may provide valuable insight into the “missing heritability” of traits and provide biological interpretations to GWAS findings.
Active Cigarette Smoking, Household Passive Smoke Exposure, and the Risk of Developing Pancreatic Cancer

Abstract Objective The objective of this study was to examine the association between active cigarette smoking, household passive smoke exposure, and pancreatic cancer risk using a prospective cohort design. Methods Two cohorts were established in Washington County, Maryland in 1963 ( n = 45,749) and 1975 ( n = 48,172). The Washington County Cancer Registry was used to ascertain the occurrence of pancreatic cancer in the 1963 cohort from 1963–1978 and in the 1975 cohort from 1975–1994. Poisson regression was used to analyze the associations between active smoking and household passive smoke exposure and pancreatic cancer risk. Results Current active smoking was associated with a two-fold increased risk of pancreatic cancer in both cohorts. Among never-smokers in each cohort, exposure to household passive smoke was not associated with an increased risk of pancreatic cancer, although the confidence limits were wide due to a small number of cases. Conclusions This study further documents the approximate doubling of pancreatic cancer risk in current active smokers. Our results also indicate that household passive smoke exposure is not associated with pancreatic cancer risk, although our risk estimates lacked precision.
Laser photolysis of 2-phenylheptamethyltrisilane

Two transient absorptions have been detected in the 266 nm laser photolysis of 2-phenylheptamethyltrisilane in cyclohexane solution at room temperature, and their time evolution was recorded in the presence and absence of air and added trapping agents. The shorter-lived 440 nm transient (t1/2 < 20μs) is tentatively assigned to the silylene :SiMePh and the more persistent 380 nm transient to the disilene MePhSiSiMePh. The reactivity of this silylene is much lower than had been expected.
Characterization of intracellular ice formation in Drosophila melanogaster embryos.

Abstract Cryomicroscopy and differential scanning calorimetry (DSC) were used to characterize the incidence of intracellular ice formation (IIF) in 12- to 13-hr-old embryos of Drosophila melanogaster (Oregon-R strain P2) as influenced by the state of the eggcase (untreated, dechorionated, or permeabilized), the composition of the suspending medium (with and without cryoprotectants), and the cooling rate. Untreated eggs underwent IIF over a very narrow temperature range when cooled at 4 or 16 °C/min with a median temperature of intracellular ice formation (TIIF 50 ) of −28 °C. The freezable water volume of untreated eggs was approximately 5.4 nl as determined by DSC. IIF in dechorionated eggs occurred over a much broader temperature range (−13 to −31 °C), but the incidence of IIF increased sharply below −24 °C, and the cumulative incidence of IIF at −24 °C decreased with cooling rate. In permeabilized eggs without cryoprotectants (CPAs), IIF occurred at much warmer temperatures and over a much wider temperature range than in untreated eggs, and the TIIF 50 was cooling rate dependent. At low cooling rates (1 to 2 °C/min), TIIF 50 increased with cooling rate; at intermediate cooling rates (2 to 16 °C/min), TIIF 50 decreased with cooling rate. The total incidence of IIP in permeabilized eggs was 54% at 1 °C/min, and volumetric contraction almost always occurred during cooling. Decreasing the cooling rate to 0.5 °C/min reduced the incidence of IIF to 43%. At a cooling rate of 4 °C/min, ethylene glycol reduced the TIIF 50 by about 12 °C for each unit increase in molarity of CPA (up to 2.0 M ) in the suspending medium. The TIIF 50 was cooling rate dependent when embryos were preequilibrated with 1.0 M propylene glycol or ethylene glycol, but was not so in x1.0 M DMSO. For embryos equilibrated in 1.5 M ethylene glycol and then held at −5 °C for 1 min before further cooling at 1 °C/min, the incidence of IIF was decreased to 31%. Increasing the duration of the isothermal hold to 10 min reduced the incidence of IIF to 22% and reduced the volume of freezable water in embryos when intracellular ice formation occurred. If the isothermal hold temperature was −7.5 or −10 °C, a 10- to 30-min holding time was required to achieve a comparable reduction in the incidence of IIF.
Comparisons of nuclear moments of inertia with particle number conserving states

Abstract A comparison is made along moments of inertia for several rare-earth nuclei calculated with BCS states, projected BCS states and projected states where minimization followed projection.
Biphasic electrophysiological effects of phenytoin on neural tissue cultures.

Abstract Cerebellar and cerebral neocortical explants were exposed to concentrations of phenytoin (DPH) ranging from 2 to 22.5 μg/ml of buffered balanced salt solution while extracellular electrical activity was recorded. DPH applied to cerebellar cultures produced a biphasic effect on cortical spontaneous activity, with an initial excitatory phase followed by more sustained suppression. The duration of each of these phases was dose dependent. A similar biphasic effect of DPH on stimulus-elicited responses in cultures of cerebral neocortex was noted. An enhancement of the amplitudes of these responses and prolonged oscillatory afterdischarges were early consequences of DPH application. After variable intervals up to 1 2 hour later, there was a prolonged attenuation of these responses. The initial excitatory effect of DPH demonstrated upon direct application to neurons in culture raises the possibility that intravenous DPH may not be the most appropriate drug for the rapid treatment of status epilepticus in man.