cssi/SciSciGPT-SciSciNet huggingface dataset:
Circular dichroism spectra of bichromophorically derivatized methyl-d-galactopyranosides, calculable by pairwise additivity, provide a basis for novel microanalysis of oligosaccharides

Abstract The spectroscopic basis for a novel alternative to methylation microanalysis for linkage determination is presented. The complex c.d. spectra of “bichromophoric” d -galactopyranoside derivatives, i.e., containing two types of exciton-coupling chromophore, namely, p-bromobenzoate (λmax 245 nm) and p-methoxycinnamate (λmax 311 nm), are highly characteristic at nanomolar levels, indicative of the sugar, the substitution pattern, and the d or l configuration. That these spectra are due to a recently demonstrated pairwise additivity is confirmed. Work directed towards an oligosaccharide derivatization-sequence, resulting in the easily identifiable tetrachromophoric monosaccharide residues, is described. Such an analysis can simultaneously accomplish identification of sugar components, linkage pattern, and determination of absolute configuration at the nanomolar level.
Quasi-Classical Trajectory Studies of the Insertion Reactions S(1D) + H2, HD, and D2†

In this work, we present the results of a quasi-classical trajectory (QCT) calculation using a newly developed potential energy surface for the title reactions. The integral cross sections, the product state-resolved differential cross sections, the angle-state-specific energy partitions, and other relevant reaction attributes are computed. The QCT integral cross sections, the differential cross sections, and the gross features of the product distributions are consistent with a simple view of the reaction as mediated by capture dynamics in the entrance channel, followed by the statistical decay of a long-lived complex. We present a comparison to the molecular beam experiments of Lee and Liu, which show agreement in the broad pattern of results but also exhibit significant differences in the more finely resolved quantities.
Molecular determinants of external barium block in Shaker potassium channels

Mutations in the outer pore region of Shaker K+ channels (T449 and D447) can influence external Ba2+ block. Substitution of T449 by A, V or Y differentially reduced Ba2+ block primarily by decreasing the blocking rate. Substitution of D447 by N resulted in a non-conducting channel with apparently normal gating currents. External Ba2+ can speed the OFF gating current of a different non-conducting mutant, W434F; this effect was markedly attenuated by the D447N substitution. These results suggest that D447 contributes to an external Ba2+ binding site while T449 imposes a barrier to the access of that site.
A Klein-Bottle-Based Dictionary for Texture Representation

A natural object of study in texture representation and material classification is the probability density function, in pixel-value space, underlying the set of small patches from the given image. Inspired by the fact that small $$n\times n$$ n × n high-contrast patches from natural images in gray-scale accumulate with high density around a surface $$\fancyscript{K}\subset {\mathbb {R}}^{n^2}$$ K ? R n 2 with the topology of a Klein bottle (Carlsson et al. International Journal of Computer Vision 76(1):1---12, 2008), we present in this paper a novel framework for the estimation and representation of distributions around $$\fancyscript{K}$$ K , of patches from texture images. More specifically, we show that most $$n\times n$$ n × n patches from a given image can be projected onto $$\fancyscript{K}$$ K yielding a finite sample $$S\subset \fancyscript{K}$$ S ? K , whose underlying probability density function can be represented in terms of Fourier-like coefficients, which in turn, can be estimated from $$S$$ S . We show that image rotation acts as a linear transformation at the level of the estimated coefficients, and use this to define a multi-scale rotation-invariant descriptor. We test it by classifying the materials in three popular data sets: The CUReT, UIUCTex and KTH-TIPS texture databases.
Characteristics of oxide-confined AlGaAs/GaAs resonant-cavity light-emitting diodes

Resonant-cavity light-emitting diodes (RCLEDs) are attractive light sources because of their applications in data communications, optical printing, display, and optical interconnects. Lower intensity LEDs with a modulation bandwidth of few hundred MHz are suitable for lower-speed optical fiber communications. In this work, we have made oxide-confied AlGaAs/GaAs RCLEDs for optical communication systems. The epitaxial layers of the RCLEDs were grown by MBE system on the N + -GaAs substrates. T he RCLED epitaxial layers mainly consisted of an n-type DBR (diffractive Bragg reflector), a p-type DBR, and an active region sandwiched between p- and n-type DBR's. The thickness of the optcal cabity is 1$lamda. Reflectance measurement of the RCLED expitaxial wafers showed that the resonance of the RCLED cavity were about 850 nm. The wet oxidation process, which defined the current conducting aperture, was done at 425 degree(s)C under nitrogen flow with steam. P-ohmic and n-ohmic contacts were then formed sequentially using electron beam evaporation and annealing. The optical power of the RCLED is measured as function of current and temperature. The beam pattern and the optical spectrum were also measured and analyzed.
Evidence for a low velocity layer at the base of the oceanic crust

As the quantity of seismic refraction data in the oceans increases it is becoming apparent1–3 that there is a systematic increase in crustal thickness with age, at least out to about 60 Myr (refs 1,2). To explain this phenomenon more precisely the detailed structure of the lower crust is required. We present seismic refraction data from the Northern Cocos plate which shows that thickening occurs by the formation of a low velocity zone (LVZ) at the base of the crust with a velocity < 6.8 km s−1. One possible explanation of this in terms of these relatively low seismic velocities for the lower crust4, is that upper mantle material becomes serpentinised by a hydration reaction as it cools. If so, this implies that the Moho boundary, except at very young ages, is a phase change (hydration) boundary. This supports the ideas of Hess5.
Selection of Antimicrobial Agents for Initial Treatment of Suspected Septicemia in Infants and Children

Septicemia is relatively common in infants and children, and empiric antimicrobial therapy is frequently necessary. In immunocompetent children the most likely causative agents are Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Salmonella species. Effective empiric therapy is often the combination of ampicillin and chloramphenicol. In immunocompromised children the etiologic possibilities in septicemia include a large number of opportunistic pathogens, the most common of which are Escherichia coli and other enteric bacilli, Pseudomonas species and other hospital-related bacilli, and Staphylococcus aureus. Empiric therapy often consists of an aminoglycoside, a penicillinase-resistant penicillin or cephalosporin, and carbenicillin or ticarcillin. The third-generation cephalosporins offer considerable promise in the empiric treatment of septicemia in children. Septicemia-defined as systemic disease resulting from the presence of microorganisms or their toxins in the circulating blood-is relatively common in infants and children. In most instances in immunocompetent children, the septicemic process occurs in association with infection and disease at a specific anatomical site; such associated conditions include meningitis, osteomyelitis, wound infection, and arthritis. Septicemia without a focus is much less common than that which occurs in association with a focus, but it still is a major concern in pediatrics. The etiology and frequency of septicemia in children are determined by host factors, such as age and degree of immunocompetence, and environmental factors, such as season, geography, animals, hospitals, day-care centers, food, and water. In the selection of empiric antimicrobial therapy for suspected septicemia, these host and environmental factors should be considered so that the most appropriate therapeutic regimen can be employed. Unfortunately, the physician all too frequently employs one mode of therapy for all "septicemic" children. This nonspecific approach results in suboptimal care and undue delays in the institution of proper therapy for some children and in the administration of unnecessary antimicrobial agents to other patients.
Facilitation of mediated transfer by instructions, B-C training, and presentation of the mediating response

This study used dominance concepts in a B-C, A-B, A-C mediation paradigm, where B was a noun, or group of nouns, and C was the common descriptive response. Presenting the B-C pairs increased the transfer from A-B to A-C when B was a group of nouns, but simply presenting the C terms had no effect. Instructions concerning the relationship of the A-B and A-C lists and presenting the B terms during the A-C learning produced slightly faster A-C learning when B was a single noun. Increasing the anticipation interval on the A-C list from 2 to 4 sec facilitated the A-C learning when it was preceded by instructions concerning the relationship of the two lists and when the B terms were presented during the A-C learning.
Experimental Investigations of Silicon Wafer Grinding

The majority of integrated circuits are built on silicon wafers. To manufacture high-quality silicon wafers, a series of processes are needed. After a wire sawing process slices silicon ingots into wafers, grinding processes can be used to flatten the sliced wafers. This paper reports three experimental investigations on wafer grinding. The first investigation was to study the effectiveness of soft-pad grinding in removing the wire-sawing induced waviness. The second was to explore the capability of grinding in achieving super flatness. The third was to study the effects of grinding parameters on wafer flatness.
Polyfluorinated compounds in dust from homes, offices, and vehicles as predictors of concentrations in office workers' serum.

Abstract We aimed to characterize levels of polyfluorinated compounds (PFCs) in indoor dust from offices, homes, and vehicles; to investigate factors that may affect PFC levels in dust; and to examine the associations between PFCs in dust and office workers' serum. Dust samples were collected in 2009 from offices, homes, and vehicles of 31 individuals in Boston, MA and analyzed for nineteen PFCs, including perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), fluorotelomer alcohols (FTOHs), and sulfonamidoethanols (FOSEs). Serum was collected from each participant and analyzed for eight PFCs including PFOA and PFOS. Perfluorononanoate, PFOA, perfluoroheptanoate, perfluorohexanoate, PFOS and 8:2 FTOH had detection frequencies > 50% in dust from all three microenvironments. The highest geometric mean concentration in office dust was for 8:2 FTOH (309 ng/g), while PFOS was highest in homes (26.9 ng/g) and vehicles (15.8 ng/g). Overall, offices had the highest PFC concentrations, particularly for longer-chain carboxylic acids and FTOHs. Perfluorobutyrate was prevalent in homes and vehicles, but not offices. PFOA serum concentrations were not associated with PFC dust levels after adjusting for PFC concentrations in office air. Dust concentrations of most PFCs are higher in offices than in homes and vehicles. However, indoor dust may not be a significant source of exposure to PFCs for office workers. This finding suggests that our previously published observation of an association between FTOH concentrations in office air and PFOA concentrations in office workers was not due to confounding by PFCs in dust.
Tailoring Outreach Efforts to Increase Primary Care Use Among Homeless Veterans: Results of a Randomized Controlled Trial.

BACKGROUND Homeless individuals often have significant unmet health care needs that are critical to helping them leave homelessness. However, engaging them in primary and mental health care services is often elusive and difficult to achieve.
Micropropagation of Camptotheca acuminata decaisne from axillary buds, shoot tips, and seed embryos in a tissue culture system

Micropropagation of the anti-cancer plant Camptotheca acuminata Decaisne from axillary buds and seed embryos was investigated. Axillary buds from greenhouse seedlings required a period of culture in media free of N6-benzyladenine (BA) before multiple shoot induction began. Direct induction of multiple shoots on BA-containing medium resulted in high mortality of the axillary buds. Multiple shoot induction from the greenhouse axillary buds was best achieved on B5 with 4.4 μM BA+0.5μM α-naphthaleneacetic acid, forming an average of three 2-mm tall shoots per bud in 8 wk. Elongation of these multiple shoots was successful at a lower BA level (0.22 μM) on B5 medium. Both in vitro and ex vitro rooting of the microcuttings was feasible with indole-3-butyric acid in the culture media, but ex vitro rooting led to high plantlet survival. Seed embryos were not ideal explants for multiple shoot induction. Shoot tips and axillary buds of in vitro-germinated seedlings showed an optimal multiple shoot formation on B5 with 8.9 μM BA, double the optimal BA level for greenhouse axillary buds. Using axillary buds to propagate C. acuminata plants in vitro is feasible for mass propagation of desired clonal lines high in camptothecin concentrations.
Reversible modulus reinforcement of end-linked polydimethylsiloxane ionomer networks

Abstract We report the mechanical behavior and swelling properties of covalently end-linked networks of polydimethylsiloxane with tailored number of monomers between side carboxyl groups and number of carboxyl groups along the chain. Imperfect carboxyl networks are reinforced by neutralization of the carboxyl groups with gallium ions via conversion of pendent chains into elastically active strands due to formation of inter-molecular ionic cross-links. These networks swell in non-polar solvents to a similar degree as unmodified end-linked PDMS networks of comparable moduli. For unannealed samples, the modulus reinforcement is reversed by a polar THF:water solution that breaks the ionic cross-links. Neutralization with transition metal cations such as cobalt causes no initial reinforcement due to weak intra-molecular interactions. Reinforcement in annealed gallium, cobalt or carboxyl networks is not readily reversible.
Mg++ dependent Na+ −K+ stimulated ATPase in the developing rat brain

Abstract The Mg++ dependent Na+ −K+ activated ATPase is already demonstrable in the brain of a 16 day old rat embryo. The ratio of this enzyme to the Mg++ dependent ATPase rapidly increases before birth.
A lattice method for option pricing with two underlying assets in the regime-switching model

Abstract In this work we develop an efficient lattice approach for option pricing with two underlying assets whose prices are governed by regime-switching models. Jump amplitudes are specified in a way such that the lattice achieves complete node recombination along each asset variable and grows quadratically as the number of time steps increases. Jump probabilities are obtained by solving a related quadratic programming problem. The weak convergence of the discrete lattice approximations to the continuous-time regime-switching diffusion processes is established. The lattice is employed to price both European and American options written on the maximum and minimum of two assets in different regimes. Numerical results are provided and compared for the European options with a Monte-Carlo simulation approach.
Developmental response of zygotes exposed to similar mutagens

Exposure of mouse zygotes to ethylene oxide (EtO) or ethyl methanesulfonate (EMS) led to high incidences of fetal death and of certain classes of fetal malformations (Generoso et al., 1987, 1988; Rutledge and Generoso, 1989). These effects were not associated with induced chromosomal aberrations (Katoh et al., 1989) nor are they likely to be caused by gene mutations (Generoso et al., 1990). Nevertheless, the anomalies observed in these studies resemble the large class of stillbirths and sporadic defects in humans that are of unknown etiology, such as cleft palate, omphalocoel, clubfoot, hydrops and stillbirths (Czeizel, 1985; Oakley, 1986). Therefore, we continue to study the possible mechanisms relating to induction of these types of zygote-derived anomalies in mice. Effects of zygote exposure to the compounds methyl methanesulfonate (MMS), dimethyl sulfate (DMS), and diethyl sulfate (DES), which have similar DNA-binding properties as EtO and EMS, were studied. DMS and DES, but not MMS, induced effects that are similar to those induced by EtO and EMS. Thus, no site-specific alkylation product was identifiable as the critical target for these zygote-derived anomalies. We speculate that the developmental anomalies arose as a result of altered programming of gene expression during embryogenesis.
Predicting Performance on State Achievement Tests Using Curriculum-Based Measurement in Reading: A Multilevel Meta-Analysis

The purpose of this synthesis was to examine the relationship between Curriculum-Based Measurement (CBM) and statewide achievement tests in reading. A multilevel meta-analysis was used to calculate the correlation coefficient of the population for 27 studies that met the inclusion criteria. Results showed an overall large correlation coefficient of .689, which was heterogeneous among studies. Study sample size, proportion of English language learners, proportion of students with disabilities, and difference in time from when CBM and statewide achievement tests were administered were statistically significant components affecting the relationship between CBM and state achievement tests. Limitations, educational implications, and directions for future research are presented.
A stochastic model for the synthesis and degradation of natural organic matter part II: molecular property distributions

A stochastic biogeochemical model has been developed to simulate the transformation and degradation of natural organic matter (NOM) using an agent-based algorithm which treats each molecule as a separate and potentially unique entity. Molecules react when a pseudo-random number is lower than the calculated reaction probability in a given time step; repeated time steps simulate the transformation of precursor molecules into a complex NOM assemblage. The data for each molecule—elemental and functional group composition—can be used to calculate many properties directly and exactly for each molecule in the assemblage, e.g., molecular weight (MW), fraction of aromatic C (Ar), and charge at pH 7 (Z). Empirical quantitative structure activity relationships (QSARs) are developed which permit the estimation of thermodynamic quantities K ow (the octanol–water partition coefficient) and pK a (acidity) for each molecule. Root mean square errors for these QSARs are 0.39 log units for log K ow and 0.45 log units for pK a. Distributions of both exactly calculated (MW, Ar, Z) and estimated thermodynamic (K ow, pK a) properties are examined and compared with published experimental data. Molecular weight distributions from size exclusion HPLC experiments on aquatic NOM are quantitatively similar to simulation results. pH titrations and polarity distributions from reversed-phase HPLC are qualitatively similar to simulation results. This agreement suggests that the agent-based model can be used to explore hypotheses regarding both compositional and thermodynamic properties of NOM.
Measurement of Plasma and Intracellular S–Adenosylmethionine and S–Adenosylhomocysteine Utilizing Coulometric Electrochemical Detection: Alterations with Plasma Homocysteine and Pyridoxal 5'–Phosphate. Concentrations

Background: The relative changes in plasma and intracellular concentrations of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) may be important predictors of cellular methylation potential and metabolic alterations associated with specific genetic polymorphisms and/or nutritional deficiencies. Because these metabolites are present in nanomolar concentrations in plasma, methods of detection generally require time-consuming precolumn processing or metabolite derivatization. Methods: We used HPLC with coulometric electrochemical detection for the simultaneous measurement of SAM and SAH in 200 mL of plasma, 10 6 lymphocytes, or 10 mg of tissue. Filtered trichloroacetic acid extracts were injected directly into the HPLC system without additional processing and were eluted isocratically. Results: The limits of detection were 200 fmol/L for SAM and 40 fmol/L SAH. In plasma extracts, the interassay CV was 3.4 ‐5.5% and the intraassay CV was
Multilevel Fast Multipole Acceleration in the Nyström Discretization of Surface Electromagnetic Integral Equations for Composite Objects

The multilevel fast multipole algorithm (MLFMA) based on the Nystrom discretization of surface integral equations (SIEs) is developed for solving electromagnetic (EM) scattering by large composite objects. Traditionally, the MLFMA is based on the method of moments (MoM) discretization for the SIEs and it usually works well when the robust Rao-Wilton-Glisson (RWG) basis function is enough to represent unknown currents. However, the RWG basis function may not represent both the electric and magnetic current in solving the electric field integral equation (EFIE) and magnetic field integral equation (MFIE) for penetrable objects, and how one represents another current could be a problem in the MoM. In this work, we use the Nystrom method as a tool to discretize the SIEs and incorporate the MLFMA to accelerate the solutions for electrically large problems. The advantages of the Nystrom discretization include the simple mechanism of implementation, lower requirements on mesh quality, and no use of basis and testing functions. These benefits are particularly desired in the MLFMA because the solved problems are very large and complex in general. Numerical examples are presented to demonstrate the effectiveness of the proposed scheme.
Virtual-reality monitoring

Investigates whether subjects could separate memories of events experienced in virtual reality from real and imagined events: a decision process we term 'virtual-reality monitoring'. Participants studied 8 separate spatial configurations of red geometric objects arranged on a life-sized chessboard, 8 configurations in virtual reality (an immersive, computer-simulated world), and imagined objects in 8 other configurations. On a later source identification memory test, subjects were generally able to correctly identify the sources of the events. A 'memory characteristics questionnaire' was administered to assess differences in qualitative characteristics of memories for virtual, real and imagined events. Differences were found that could potentially serve as cues to help people decide where their memories originated. Results are interpreted within the Johnson-Raye (1981) theoretical framework.
Internal-flow Nusselt numbers for the low-Reynolds-number end of the laminar-to-turbulent transition regime

For heat exchange devices that operate in the low-Reynolds-number end of the laminar-to-turbulent transition regime, logical design is thwarted by the absence of reliable Nusselt number information. The currently accepted Nusselt number correlation for the transition regime, due to Gnielinski, is restricted to the high-Reynolds-number end of that regime. This limitation results from the need for a valid friction factor—Reynolds correlation for input to the Gnielinski equation. Heretofore, such correlations have been unavailable for the low-Reynolds-number end. By the application of a new fluid flow model which is valid for all flow regimes and smoothly and automatically bridges between regimes, the needed correlations have been determined. On this basis, fully developed Nusselt number results are provided for (a) a round pipe of axially uniform cross section, (b) the downstream end of a round pipe fitted with a conical enlargement (diverging nozzle) at its upstream end, and (c) a parallel-plate channel. All results are for a fluid with Prandtl number equal to 0.7.
THEORY OF NANOTUBE NANODEVICES

The paper reviews quantum and classical effects which arise in physics of nanotube devices. Knowledge of nanotube electronic structure has been used for a calculation of quantum capacitance and quantum terms in van der Waals energy. Combining analytical theory and quantum mechanical micromodels I worked out a description for nanoelectromechanical devices, for example, electromechanical switch. The theory takes into account van der Waals forces which show up at the nanoscale and result in appearing of a principal limitation for scaling down NEMS structures. A model, which has been derived for a nanotube device electrostatics, includes an atomistic polarizability of the nanotube in a selfconsistent way. This calculation yields a charge density distribution for given external fields and specific device parameters. On the basis of these main elements of continual compact modeling: quantum mechanical description of the nanotube electronic structure, theory of the van der Waals forces, quantum capacitance and continuum mechanics,– a general theory of nanodevices is proposed.
The Physical Reality of Space and Surface Waves in the Radiation Field of Radio Antennas

Evidence is presented which indicates that, notwithstanding the change in sign made by Sommerfeld in his 1926 paper on radio wave propagation, the radiation field of a vertical electric dipole may be separated into space and surface wave components. Sommerfeld's original concepts as to the characteristics of two such waves in radio transmission are largely substantiated. It is shown that a space and a surface wave are generated by a simple vertical dipole antenna at the surface of the earth and that this surface wave has the same wave tilt as the Sommerfeld surface wave. Evidence is given which would indicate that this surface wave travels around the curve of the earth in much the same manner as a guided wire wave travels around a bend on a wire. In the appendix formulas are given for the space and surface waves in the radiation fields of a horizontal electric dipole and of horizontal and vertical magnetic dipoles.
Are item-level strategy shifts abrupt and collective? Age differences in cognitive skill acquisition.

Item-level analysis allows for the examination of qualitative age and individual differences in skill acquisition, which are obscured when aggregating data across items. In the present study, item-level strategy shifts were generally gradual and variable, rather than abrupt and collective. Strategy shift reversions were frequent, and the total transition space was extensive, for both younger and older adults. Shift indices were highly variable between items for both younger and older adults. Age differences in item-level shift patterns suggest that older adults’ greater conservatism in strategy selection leads to more gradual strategy shift transitions for individual items as well as to more collective strategy shifts.
Postsynaptic modulation of rectifying electrical synaptic inputs to the LG escape command neuron in crayfish

The lateral giant (LG) tail-flip escape system of crayfish is organized to provide a massive convergence of mechanosensory inputs onto the LG command neuron through electrical synapses from both mechanosensory afferents and interneurons. We used electrophysiological techniques to show that the connections between three major mechanosensory interneurons and LG rectify, and that their inputs to LG can be reduced by postsynaptic depolarization and increased by postsynaptic hyperpolarization. The mechanosensory afferents and interneurons are excited by sensory nerve shock, and the components of the resulting LG PSP can be similarly modulated by the same postsynaptic potential changes. Because these inputs are all made through electrical synapses, we conclude that they are rectifying connections, as well. To test the physical plausibility of this conclusion, we developed an electrical model of the rectifying connection between a mechanosensory interneuron and LG, and found that it can reproduce all the qualitative features of the orthodromic and antidromic experimental responses. The ability of postsynaptic membrane potential to modulate inputs through rectifying electrical synapses is used in the escape system to enhance LG’s relative sensitivity to novel, phasic stimuli. Postsynaptic depolarization of LG produced by earlier inputs “reverse-biases” the rectifying input synapses and reduces their strength relative to times when LG is at rest.
Music Analysis Using Hidden Markov Mixture Models

We develop a hidden Markov mixture model based on a Dirichlet process (DP) prior, for representation of the statistics of sequential data for which a single hidden Markov model (HMM) may not be sufficient. The DP prior has an intrinsic clustering property that encourages parameter sharing, and this naturally reveals the proper number of mixture components. The evaluation of posterior distributions for all model parameters is achieved in two ways: 1) via a rigorous Markov chain Monte Carlo method; and 2) approximately and efficiently via a variational Bayes formulation. Using DP HMM mixture models in a Bayesian setting, we propose a novel scheme for music analysis, highlighting the effectiveness of the DP HMM mixture model. Music is treated as a time-series data sequence and each music piece is represented as a mixture of HMMs. We approximate the similarity of two music pieces by computing the distance between the associated HMM mixtures. Experimental results are presented for synthesized sequential data and from classical music clips. Music similarities computed using DP HMM mixture modeling are compared to those computed from Gaussian mixture modeling, for which the mixture modeling is also performed using DP. The results show that the performance of DP HMM mixture modeling exceeds that of the DP Gaussian mixture modeling.
Fuel cell status: 1996

The technology of fuel cells is heating up. A world that, ten years ago, was unaware of the concept can now witness approximately 200 fuel cell units operating in 15 countries. Energy planners and decision makers are becoming aware that, in addition to a continual increase in installations, the reliability of early commercial units is outstanding and the cost is dropping. They have begun to ask whether fuel cells might fit into their future. While the fuel cell concept is simple, determining which type of fuel cell to consider may prove taxing. The multiplicity of fuel cells and their development programs, coupled with the amount of subject material and claims-versus-reality, may seem overwhelming. Fuel cell commercialization activities in North America are the focus of five manufacturers that are developing four types [fuel cells are typed by electrolyte: the 200/spl deg/C phosphoric acid (PAFC); the 80/spl deg/C proton exchange membrane (PEM); the 650/spl deg/C molten carbonate (MCFC); and the 1,000/spl deg/C solid oxide (SOFC) fuel cells]. Each fuel cell promises the attractive combination of fairly high efficiency and superior environmental performance compared to the presently available fossil-fueled electric generation technologies. As a result, fuel cells are particularly easy to site. There are additional advantages such as: excellent availability; electrical VAR control; quick ramp rate; remote/unattended operation; and redundancy when multiple units are installed. After earlier success in space, fuel cells are being applied to the commercial sector as on-site cogeneration units mostly fueled by natural gas. They are being considered for larger distributed generators (natural gas) and for vehicular power plants (methanol).
Managing nuclear power plant induced disasters.

Objective: To understand the management process of nuclear power plant (NPP) induced disasters. The study shields light on phases and issues associated with the NPP induced disaster management. Setting: This study uses Palo Verde Nuclear Generation Station as study subject and Arizona State as study area. Design: This study uses the Radiological Assessment System for Consequence Analysis (RASCAL) Source Term to Dose (STDose) of the Nuclear Regulatory Commission, a computer software to project and assess the source term dose and release pathway. This study also uses ArcGIS, a geographic information system to analyze geospatial data. A detailed case study of Palo Verde Nuclear Power Generation (PVNPG) Plant was conducted. Results: The findings reveal that the NPP induced disaster management process is conducted by various stakeholders. To save lives and to minimize the impacts, it is vital to relate planning and process of the disaster management. Conclusions: Number of people who expose to the radioactive plume pathway and level of radioactivity could vary depending on the speed and direction of wind on the day the event takes place. This study findings show that there is a need to address the burning issue of different racial and ethnic groups’ unequal exposure and unequal protection to potential risks associated with the NPPs.
The Predicament of Comparative Effectiveness Research Using Observational Data

In this issue, Hansen and colleagues' observational study compared outcomes for patients who had early versus conservative invasive treatment for acute coronary syndromes. The editorialists discuss...
X-ray absorption spectroscopy structural investigation of early intermediates in the mechanism of DNA repair by human ABH2

Human ABH2 repairs DNA lesions by using an Fe(II)- and αKG-dependent oxidative demethylation mechanism. The structure of the active site features the facial triad of protein ligands consisting of the side chains of two histidine residues and one aspartate residue that is common to many non-heme Fe(II) oxygenases. X-ray absorption spectroscopy (XAS) of metallated (Fe and Ni) samples of ABH2 was used to investigate the mechanism of ABH2 and its inhibition by Ni(II) ions. The data are consistent with a sequential mechanism that features a five-coordinate metal center in the presence and absence of the α-ketoglutarate cofactor. This aspect is not altered in the Ni(II)-substituted enzyme, and both metals are shown to bind the cofactor. When the substrate is bound to the native Fe(II) complex with α-ketoglutarate bound, a five-coordinate Fe(II) center is retained that features an open coordination position for O2 binding. However, in the case of the Ni(II)-substituted enzyme, the complex that forms in the prese...
Characteristics of cervical mucus from progestagen-treated cattle

SUMMARY Five characteristics of cervical mucus were investigated to determine if abnormalities might be responsible for the lowered fertility observed in cattle following progestagen administration. Mucus from animals fed 1 mg of melengestrol acetate (MGA) daily for 3 and 14 days did not differ significantly from that of controls in quantity, crystallization patterns or alkaline phosphatase content. However, on the last day of MGA feeding (day 14) treated animals had thicker mucus (P Based on quantity, consistency and alkaline phosphatase content of mucus from treated animals on day 4 after MGA withdrawal and from control animals on the day of oestrus, there appears to be no reason to indict cervical mucus as the cause of lowered fertility in MGA-treated animals. However, the altered crystallization patterns and sperm migration might indicate changes of significance in relation to feritlity.
GONOPORES AND THE REPRODUCTIVE SYSTEM OF NECTIOPODAN REMIPEDIA

Nectiopodan remipedes have two distinct pairs ofgonopores. The previously recognized pore on the fourteenth limb is that of the male system. Another gonopore, located on the seventh trunk limb, is associated with the female system. It occurs on the posterior side of the seventh protopod. In the adults of Lasionectes entrichoma the female gonopore complex consists of a semicircular chitinous ridge and a discoidal soft pad that is partly encircled by the ridge. The actual gonopore is in a trough located between the pad and the ridge. The internal location of the gonads and gonoducts in nectiopodans is now known at least in broad outline.
“We Will Gladly Join You in Partnership in Harrisburg or We Will See You in Court”: The Growth of Large Not-for-Profits and Consequences of the “Eds and Meds” Renaissance in the New Pittsburgh

In 1990, Mayor Sophie Masloff warned large not-for-profits, like the University of Pittsburgh Medical Center (UPMC), that unless they started making an increased financial contribution in the form ...
A visual analytics approach to high-dimensional logistic regression modeling and its application to an environmental health study

In the domain of epidemiology, logistic regression modeling is widely used to explain the relationships among explanatory variables and dichotomous outcome variables. However, logistic regression modeling faces challenges such as overfitting, confounding, and multicollinearity when there is a large number of explanatory variables. For example, in the birth defect study presented in this paper, variable selection for building high quality models to identify risk factors from hundreds of pollutant variables is difficult. To address this problem, we propose a novel visual analytics approach to logistic regression modeling for high-dimensional datasets. It leverages the traditional modeling pipeline by providing (1) intuitive visualizations for inspecting statistical indicators and the relationships among the variables and (2) a seamless, effective dimension reduction pipeline for selecting variables for inclusion in high quality logistic regression models. A fully working prototype of this approach has been developed and successfully applied to the birth defect study, which illustrates its effectiveness and efficiency. Its application in an insurance policy study and feedback from domain experts further demonstrate its usefulness.
Pulmonary embolism: emboli and fibrinolysis inhibition in isolated canine lungs.

The effect of fibrinolysis inhibition with tranexamic acid on pulmonary microvascular permeability during glass bead embolization was investigated in the isolated lung. Lung lobes from nonhepariniz...
Implementation of nanotechnology in improving the environmental compliance of construction projects in the United States

ABSTRACTNanotechnology, defined as the science of very small matter called nanomaterial, comprises the study of chemical and physical properties of particles which are structured in sizes ranging from 1 to 100 nm. At this size range, nanomaterial exhibits superior chemical and physical characteristics as compared to those displayed while existing in normal size. To date, multiple nanotechnology research centers within the United States are investigating the potential use of different types of nanoparticles as titanium dioxide (TiO2) in the construction industry to attain superior characteristics of building materials, improve their rating as environmentally friendly material, and improve the overall LEED rating of construction projects.The major impediments to the widespread implementation of nanotechnology include high nanomaterial cost, lack of industrial experience, and absence of standard specifications for building materials incorporating nanoparticles. This research article presents a research effor...
Quantum calculation of thermal effect in quantum-dot cellular automata: Research Articles

We present a theoretical study of thermal effect in quantum-dot cellular automata (QCA). An extended Hubbard-type model for the Hamiltonian of the QCA arrays, and canonical distribution were used to obtain thermal average of polarization for the QCA cells. A full-basis quantum method has been used for the calculation of response function for a two- and a three-cell array system. Each cell is composed of four dots located at the corners of the cells. Results show that the nonlinear behavior of the response function functions decay with the temperature as well as with the number of cells in the array. © 2005 Wiley Periodicals, Inc. Complexity 10: 73–78, 2005
Widely tunable semiconductor lasers with three interferometric arms

We present a comprehensive study for a new three-branch widely tunable semiconductor laser based on a self-imaging, lossless multi-mode interference (MMI) coupler. We have developed a general theoretical framework that is applicable to all types of interferometric lasers. Our analysis showed that the three-branch laser offers high side-mode suppression ratios (SMSRs) while maintaining a wide tuning range and a low threshold modal gain of the lasing mode. We also present the design rules for tuning over the dense-wavelength division multiplexing grid over the C-band.
Integrating Health Coaching With a Medical Fitness Program to Treat Chronic Health Conditions

Medical fitness and health/wellness coaching (HWC) are emerging health care trends but potential synergistic effects are yet to be studied. Purpose. To determine the impact of integrating HWC withi...
Can Virtual Reality Engage Students with Teamwork

Graduates’ ability to work well in teams is highly valued by employers, but teamwork is seldom taught as an explicit skill at the tertiary level. Rather, students tend to form and retain negative attitudes towards teamwork. Some proponents have proposed that immersive virtual reality (IVR) technology could make student learning more engaging. This study explored whether the immersive nature of VR headsets improved engagement with teamwork in a first-year science communication unit. We measured students’ attitudes and motivation before and after completing a tutorial designed to develop teamwork skills, and asked students to assess their peers’ teamwork behaviours. In small groups, students in IVR tutorials collaboratively solved a puzzle in an IVR maze, while students in control tutorials completed an equivalent paper-based activity. Both interventions resulted in students developing slightly more negative attitudes towards teamwork. The IVR group was slightly more likely to report their teammates displayed dominating behaviours. On most measures, students’ attitudes and motivation toward teamwork remained fixed even when tutors reported positive experiences in class. Feedback regarding drawbacks (such as nausea and costs) suggests that the addition of IVR technology is not a panacea for student engagement with teamwork.
Host noncoding retrotransposons induced by DNA viruses: a SINE of infection?

Our genomes are dominated by repetitive elements. The majority of these elements derive from retrotransposons, which expand throughout the genome through a process of reverse transcription and integration. Short interspersed nuclear elements, or SINEs, are an abundant class of retrotransposons that are transcribed by RNA polymerase III, thus generating exclusively noncoding RNA (ncRNA) that must hijack the machinery required for their transposition. SINE loci are generally transcriptionally repressed in somatic cells but can be robustly induced upon infection with multiple DNA viruses. Recent research has focused on the gene expression and signaling events that are modulated by SINE ncRNAs, particularly during gammaherpesvirus infection. Here, we review the biology of these SINE ncRNAs, explore how DNA virus infection may lead to their induction, and describe how novel gene regulatory and immune-related functions of these ncRNAs may impact the viral life cycle.
Outcomes Following Cordotomy by Coblation for Bilateral Vocal Fold Immobility.

Importance Bilateral vocal fold immobility (BVFI) can result in considerable voice and airway impairment. Although the carbon dioxide (CO2) laser is commonly used in transverse cordotomy, the coblator, a minimally invasive, low-thermal technology, has been increasingly used in otolaryngology. Objective To investigate outcomes associated with coblation to treat BVFI. Design, Setting, and Participants A retrospective case series was conducted between January 2012 and June 2017 including 19 patients with BVFI who underwent cordotomy by coblation in a single tertiary care institution. Main Outcomes and Measures Clinical, operative, and health status data for all patients were reviewed. Quality of life was measured by the EuroQol 5-Dimensions (EQ-5D), and the Voice Handicap Index (VHI) was used to measure vocal cord function. Results Nineteen patients were eligible for inclusion, 15 of which underwent cordotomy by coblation for BVFI without stenosis. Mean age was 57 years with 13 (68%) women. The etiology of BVFI included thyroidectomy in 8 (42%) patients and prolonged intubation in 7 (37%). Mean length of surgery for BVFI without stenosis was 17 minutes; mean operating room (OR) time was 63 minutes compared with 88 scheduled OR minutes (effect size, 25 minutes; 95% CI, 9 to 40 minutes). During follow-up, 4 (27%) of these patients developed granulation tissue postoperatively. Following surgery, patient-reported shortness of breath significantly improved, with 10 of 14 (71%; 95% CI, 45% to 88%) patients with some level of preoperative breathing difficulty experiencing improvement in their breathing. Stridor also significantly improved, with 10 of 12 (83%; 95% CI, 55% to 95%) patients with some level of preoperative stridor improved after surgery. The EQ-5D results trended toward improvement postoperatively (0.67 to 0.80; effect size, 0.13; 95% CI, −0.10 to 0.34). The functional (22 to 12; effect size, −10; 95% CI, −19 to −2), emotional (23 to 11; effect size, −12; 95% CI, −23 to −3), and total VHI all significantly improved (68 to 39; effect size, −29; 95% CI, −49 to −8). Conclusions and Relevance Initial outcomes of cordotomy by coblation revealed that this technique was a safe and efficient approach to treating BVFI. Coblation was associated with significant reduction in OR time compared with scheduled time, and patients experienced significant improvement in shortness of breath, stridor, and vocal cord function.
Cache-tries: concurrent lock-free hash tries with constant-time operations

Concurrent non-blocking hash tries have good cache locality, and horizontally scalable operations. However, operations on most existing concurrent hash tries run in O(log n) time. In this paper, we show that the concurrent hash trie operations can run in expected constant time. We present a novel lock-free concurrent hash trie design that exerts less pressure on the memory allocator. This hash trie is augmented with a quiescently consistent cache, which permits the basic operations to run in expected O(1) time. We show a statistical analysis for the constant-time bound, which, to the best of our knowledge, is the first such proof for hash tries. We also prove the safety, lock-freedom and linearizability properties. On typical workloads, our implementation demonstrates up to 5X performance improvements with respect to the previous hash trie variants.
Argument Mining for Improving the Automated Scoring of Persuasive Essays

End-to-end argument mining has enabled the development of new automated essay scoring (AES) systems that use argumentative features (e.g., number of claims, number of support relations) in addition to traditional legacy features (e.g., grammar, discourse structure) when scoring persuasive essays. While prior research has proposed different argumentative features as well as empirically demonstrated their utility for AES, these studies have all had important limitations. In this paper we identify a set of desiderata for evaluating the use of argument mining for AES, introduce an end-to-end argument mining system and associated argumentative feature sets, and present the results of several studies that both satisfy the desiderata and demonstrate the value-added of argument mining for scoring persuasive essays.