cssi/SciSciGPT-SciSciNet huggingface dataset:
Estimating nominal strength of built-up CFRP laminates from standardized specimen tests

Abstract ASTM Standard D7290 defines a standard practice for determining the characteristic strength of polymeric composites for structural engineering applications. The characteristic strength is based on the estimate of the 5th percentile of strength modeled by a two-parameter Weibull distribution, in which the distribution parameters are determined from standardized methods of testing for tensile properties of the composite material, e.g., ASTM D638 or D3039. The situation frequently arises, particularly in field applications involving structural rehabilitation and retrofit, where the composite is applied in layers to achieve the required engineering strength properties. In these circumstances, the 5th percentile strength of the in situ composite laminate system may differ from the 5th percentile strength of the single-layer lamina that has been determined from standard laboratory testing. This technical note employs system reliability methods to determine the characteristic strength of an in situ composite system consisting of 2–25 laminae. It is found that using the 5th percentile strength determined from a standardized test of one lamina to estimate the comparable strength of an n -laminate composite system will lead to an unconservative estimate of the strength of the installed system.
Clinical reactivation of genital herpes simplex virus infection decreases in frequency over time.

Herpes simplex virus type 2 infection continues to be a chronic remitting illness. Over time, however, clinically significant reductions in the frequency of recurrence occur in a majority of patients.
Accumulation of uridine diphosphoglucose pyrophosphorylase in Dictyostelium discoideum via preferential synthesis.

Abstract At the end of the exponential growth phase, the enzyme UDP-glueose pyrophosphorylase is present in the vegetative cells of Dictyostelium discoideum NC4 (haploid) at a low level (about 0.05% of total protein). During the initial stages of fruiting body construction, while the cells are entering into multicellular aggregates, the enzyme level remains constant, but increases dramatically thereafter reaching a peak (about 0.5% of total protein) at the end of fruiting body construction, and then partially decreasing. Previous studies have shown that both the accumulation and disappearance are keyed to the flow of morphogenetic events. In this study, cells were labeled with amino acids for different periods throughout the sequence. The enzyme was quantitatively immune-precipitated from crude cell extracts, the precipitate was washed and redissolved, and the enzyme protein separated by acrylamide gel electrophoresis in order to estimate the differential incorporation ratio, i.e. disints min in enzyme protein per 10 8 cells disints min in total protein per 10 8 cells × 100 for each labeling period. During the initial stages, when the enzyme level remained relatively constant, this ratio was about 0.03 to 0.04%. As the enzyme began to accumulate it rose progressively, attaining levels of 0.6 to 0.8% toward the end of fruiting body construction before declining. The data are not consistent with the theory of Gustafson and Wright (1973) that differential turnover controls the level of this enzyme during the development of D. discoideum. They are consistent with the conclusion that directed changes in the differential rate of synthesis of UDP-glucose pyrophosphorylase is the controlling element. The estimates of enzyme content are based on a value for the specific enzyme activity of 100,000 units/mg enzyme, which had been determined previously using samples of the enzyme purified to apparent physical homogeneity. This figure has been confirmed in the present study by quantitative immuneprecipitation of the enzyme from crude extracts of homogeneously labeled cells. The method can be generally used to determine if a specific biological activity estimate obtained with a purified protein is consistent with its activity when measured before or during purification.
Reaction of tetra-O-acetyl-α-d-hexopyranosyl bromides with sodium p-nitrophenoxide in N,N-dimethylformamide. Formation of p-nitrophenyl 2,3,4,6-tetra-O-acetyl-β-d-hexopyranosides versus 2,3,4,6-tetra-O-acetyl-1,5-anhydro-d-hex-1-enitols

Abstract The reaction of the four acetylated hexopyranosyl bromides ( d -allo, d -gluco, d -gulo, and d -galacto) with sodium p-nitrophenoxide in N,N-dimethylformamide was investigated in order to determine their tendency for displacement at C-1 (to form the p-nitrophenyl 2,3,4,6-tetra-O-acetyl-β- d -hexopyranoside) or β-elimination (to give the 2,3,4,6-tetra-O-acetyl-1,5-anhydro- d -hex-l-enitol). The tendency for the formation of tetra-O-acetyl-1,5-anhydro- d -hex-l-enitols decreased in the following order: d -allo > d -gulo ≳ d -gluco > d -galacto, whereas the preference for the formation of p-nitrophenyl tetra-O-acetyl-β- d -hexopyranosides was in the reverse order ( d -allo d -gulo ≲ d -gluco d -galacto). The conformations of the four tetra-O-acetyl-1,5-anhydro- d -hex-l-enitols ( d -ribo, d -arabino, d -xylo, and d -lyxo) were determined from their 250-MHz >1H-n.m.r. data; the d -lyxo derivative was determined to exist in the H54( d ) conformation, whereas the H45( d ) conformation was demonstrated for the other three isomers. The yields of the four tetra-O-acetyl-1,5-anhydro- d -hex-l-enitols were found to be directly related to factors governing the stability of their conformations.
Gauge fields on the null plane

The theory of gauge fields interacting with fermions is quantized on the null plane. The singularities of the gauge field propagator are related to the infrared divergences of the theory and cancel in the gauge-invariant sector. Ultraviolet divergences are due only to the high-transverse-momentum behavior and in the gauge-invariant sector are eliminated by coupling-constant renormalization. Equivalence to the covariant-gauge formulation is proved by explicitly performing the gauge transformation. Gauge-invariant ultraviolet and infrared cutoffs which preserve unitarity are used wherever necessary. Gauge-variant amplitudes are infrared divergent and non-Lorentz invariant. (AIP)
Electron collisional rate coefficients for low-level transitions in hydrogen

There exists presently no general agreement concerning the collisional excitation rates of atomic hydrogen. The present investigation is concerned with the results reported by various investigators, taking into account the semiempirical rates of Johnson (1972), a study conducted by Aggarwal (1983), empirically based rates of Crandall et al. (1974), and the rates tabulated in Osterbrock (1974), based on the close-coupling calculations of Burke et al. (1967). It is found that there is a major conflict between the 'best' theoretical and Johnson values on the one hand, and the empirical data on the other. A study of the data shows that the Johnson value for the 1 to 2 rate agrees well with other theoretical calculations, and within 25 percent of empirical measurements, but that the Johnson 1 to 3 rate is 40-75 percent of the 'best' theoretical calculations.
Statistical multi-resolution schemes for historical document binarization

In previous work , we proposed the application of the Expectation-Maximization (EM) algorithm in the binarization of historical documents by defining a multi-resolution framework. In this work, we extend the multiresolution framework to the Otsu algorithm for effective binarization of historical documents. We compare the effectiveness of the EM based binarization technique to the Otsu thresholding algorithm on historical documents. We demonstrate how the EM can be extended to perform an effective segmentation of historical documents by taking into account multiple features beyond the intensity of the document image. Experimental results, analysis and comparisons to known techniques are presented using the document image collection from the DIBCO 2009 contest.
BIOCHEMICAL CHARACTERIZATION OF THE HUMAN LIVER CYTOCHROME P450 ARACHIDONIC ACID EPOXYGENASE PATHWAY

Abstract Human liver microsomal fractions metabolized arachidonic acid in the presence of NADPH yielding epoxyeicosatrienoic acids and their hydration products, dihydroxyeicosatrienoic acids, as the principal reaction products. Inhibition studies using polyclonal antibodies prepared against recombinant CYP2C8, an abundant human liver cytochrome P450 epoxygenase, demonstrated 85–90% inhibition of arachidonic acid epoxide formation. Both epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids were detected in large amounts in human liver using gas chromatography/mass spectrometry. Chiral analysis of the endogenous liver epoxides demonstrated a preference for the 14(R),15(S)-, 11(R),12(S)-, and 8(S),9(R)-epoxyeicosatrienoic acid enantiomers. Importantly, the chirality of liver epoxyeicosatrienoic acids matched that previously reported for recombinant CYP2C8 (Zeldinet al.(1995)Arch. Biochem. Biophys.322, 76–86). Incubations of both human liver cytosolic and microsomal fractions with synthetic epoxyeicosatrienoic acids revealed a 10-fold higher rate of dihydroxyeicosatrienoic acid formation with cytosolic relative to microsomal fractions. Recombinant human liver cytosolic epoxide hydrolase rapidly and regioselectively hydrated epoxyeicosatrienoic acids. We conclude, based on these data, that CYP2C8 is one of the primary, constitutive hepatic arachidonic acid epoxygenases responsible for formation of epoxyeicosatrienoic acids and that cytosolic epoxide hydrolase is the principal liver enzyme which forms the dihydroxyeicosatrienoic acids. We speculate that these biologically active eicosanoids may be important in maintaining homeostasis in the liver.
Immobilized enzymes: Lactase bonded to stainless steel and other dense carriers for use in fluidized bed reactors

Abstract Lactase has been attached to stainless steel and other dense carriers for use in fluidized bed reactors. The support is activated by coating it with a layer of titanium oxide. Heating the activated support at 538° before contacting with enzyme solution seems to improve catalytic activity and stability of supported lactase. Optimum pH of free and supported enzyme was 4.5. Optimum temperature for free enzyme was 60°; for steel-supported lactase, it was 70°. Heat treated steel-lactase adduct retained 44.5% of initial activity after 5 weeks at 45° under water. The bonding method has also been applied successfully to α-amylase, amyloglucosidase, asparaginase, catalase and trypsin. Inactivated catalyst can be regenerated by heating to 538°, cooling and recontacting with enzyme solution. This is believed to be the first report of enzymes bonded to stainless steel.
Tracer mixing at fracture intersections

Discrete network models are one of the approaches used to simulate a dissolved contaminant, which is usually represented as a tracer in modeling studies, in fractured rocks. The discrete models include large numbers of individual fractures within the network structure, with flow and transport described on the scale of an individual fracture. Numerical simulations for the mixing characteristics and transfer probabilities of a tracer through a fracture intersection are performed for this study. A random-walk, particle-tracking model is applied to simulate tracer transport in fracture intersections by moving particles through space using individual advective and diffusive steps. The simulation results are compared with existing numerical and analytical solutions for a continuous intersection over a wide range of Peclet numbers. This study attempts to characterize the relative concentration at the outflow branches for a continuous intersection with different flow fields. The simulation results demonstrate that the mixing characteristics at the fracture intersections are a function not only of the Peclet number, but also of the flow field pattern.
Visual search for basic versus nonbasic chromatic targets

At the OSA topical meeting on Applied Vision in July, 1989, we presented evidence showing that, when focal examples of basic colors were employed, as many as nine kinds of irrelevant colors could be added to an information display with very little increase in the time required to search for a target of known color containing a critical spatial element. [1] Here we compare search performance using seven chromatic basic colors with that obtained with seven nonbasic ones. The seven nonbasic colors were selected to be separated from other nonbasic colors by approximately the same number of discriminably-different steps as were the seven basic colors separated from one another. Our prediction that critical targets of basic colors would nevertheless be spotted faster than those of nonbasic colors was not supported. Compared to performance when the critical-target color was unknown, search times were very short and similar for the two color types, including a condition involving 140 stimuli in the display (70 basic and 70 nonbasic), 130 of which were distractors of 13 irrelevant colors. We conclude that useful color coding for visual search probably depends upon the number of discriminable steps separating the colors, rather than their basic or nonbasic character.
Gene-Specific Messenger RNA: Isolation by the Deletion Method

Messenger RNA molecules, homologous to a small portion of the genome of bacteriophage T4, have been isolated. RNA fragments specific to the rII A and the rII B cistrons have been separated by hybridization with DNA isolated from appropriate deletion mutants. An RNA species homologous in nucleotide sequence to a defined part of the rII A cistron has been identified.
Effects of the Initial Boundary-Layer State on Turbulent Jet Mixing

Theme A MAJOR problem in many jet mixing flows is scaling, since research and development tests are usually done at much lower Reynolds numbers than the full scale application. It often occurs that if no special tripping is done, the initial boundary layer in the jet of a subscale test is laminar, while the full scale hardware will have a turbulent boundary layer. One of the primary goals of our investigation of initial boundary layer effects was to evaluate the importance of this difference on the accuracy of full scale predictions deduced from model tests. Secondary objectives included a study of the reasons for the differences in core lengths obtained by different investigators and possible isolation of particular boundary-layer characteristics that enhance turbulent mixing rates. Both axisymmetric and two-dimensional free jet flowfields exhibit a power law dependence for the decay of centerline velocity with distance from nozzle exit at points that are well downstream of the initial mixing region. However, variations in shear layer properties close to the jet exit can cause the centerline velocity profile to shift upstream or downstream under different operating conditions. Measurements made by different investigators in flowfields produced by similar nozzles frequently show significant variations in core length; the far field centerline velocity decay, however, follows a predictable variation with axial distance. Much of this earlier research on turbulent mixing in free jets has addressed cases where the effects of initial conditions were intentionally minimized. The few cases in which data regarding initial conditions are available indicate that the effects of nozzle boundary layers on mixing rates are often significant. While there are many aspects of turbulent mixing that warrant further investigation, it was the consensus of both the attendees and the review committee at the Langley Working Conference on Free Turbulent Shear Flows that the effect of initial conditions is a primary area requiring study. In this paper we describe some effects of nozzle wall boundary-layer conditions on incompressible air jets discharging into quiescent surroundings. This investigation included the influence of the boundary-layer state on the turbulent mixing layer surrounding axisymmetric and two-dimensional free jets and on time averaged measurements obtained in these flows.
Methanol synthesis on a Cu(100) catalyst

The synthesis of methanol on a Cu(100) single crystal surface was studied between 500–550 K and at pressures between 44–102 kPa using a gas mixture of CO2/CO/H2 = 1/2/12. The specific reaction rates found for methanol synthesis were approximately an order of magnitude lower than those rates previously reported for silica supported, Cu-based catalysts. Furthermore the rates observed for the Cu(100) catalyst are estimated to be several orders of magnitude smaller than those rates found for ZnO supported Cu catalysts at comparable reaction conditions. The very low concentration of ionic copper species on the surface is thought to be responsible for the low activity of the Cu(100) catalyst.
Nanoscale protein patterning by imprint lithography

Selective localization of active proteins to patterns or specific sites is important for development of biosensors, bioMEMS, tissue engineering, and basic proteomic research. We present a flexible technique for selectively patterning bioactive proteins with nanoscale resolution using nanoimprint lithography and fluoropolymer surface passivation, and exploiting the specificity of the biotin/streptavidin linkage. This technique achieves high throughput reproducible nanoscale protein patterns with high selectivity and retained biofunctionality, as demonstrated by interactions between patterned antibodies and their antigen.
Probabilistic fatigue damage prognosis of lap joint using Bayesian updating

A general framework for probabilistic prognosis and uncertainty management under fatigue cyclic loading is proposed in this article. First, the general idea using the Bayesian updating in prognosis...
Computing Bessel functions of the second kind in extreme parameter regimes

Abstract A useful method of computing the integral order Bessel functions of the second kind Y n ( x +i y ) when either, the absolute value of the real part, or the imaginary part of the argument z = x +i y is small, is described. This method is based on computing the Bessel functions for extreme parameter regimes when x ∼0 (or y ∼0) and is useful because a number existing algorithms and methods fail to give correct results for small x or small y . The approximating equations are derived by expanding the Bessel function in Taylor series, are tested and discussed. The present work is a continuation of the previous one conducted in regard to the Bessel function of the first kind. The results of our formalism are compared to the available existing numerical methods used in Mathematica, IMSL, MATLAB, and the Amos library. Our numerical method is easy to implement, efficient, and produces reliable results. In addition, this method reduces the computation of the Bessel functions of the second complex argument to that of real argument which simplify the computation considerably.
Inter- and Intraobserver Reliability of Two-dimensional CT Scan for Total Knee Arthroplasty Component Malrotation

Background Rotational malalignment of total knee arthroplasty (TKA) has been correlated with patellofemoral maltracking, knee instability, and stiffness. CT is the most accurate method to assess rotational alignment of prosthetic components after TKA, but inter- and intraobserver reliability of CT scans for this use has not been well documented.
The social dimensions of correctional officer stress

Based on a survey of line staff in a southern correctional system, we analyzed how various stressors, coping factors, and status characteristics influenced three types of stress: work stress, job dissatisfaction, and life stress. The stressors of role problems and perceived dangerousness were positively related to multiple forms of stress. While supervisory support mitigated both work stress and job dissatisfaction, the effects of other coping factors were variable. Black and educated officers had higher levels of dissatisfaction, while female officers experienced more stress on the job. Taken together, the independent variables in our framework accounted for a large amount of the variance of work stress, a moderate amount of job dissatisfaction, and a relatively low amount of life stress. Apart from the specific findings, the data suggest that theoretical models of officer stress must incorporate coping factors and specify how the dimensions of an officer's occupational role and personality differentiall...
Gadolinium Oxide Gate Dielectrics for GaN MOSFETs

Substrate preparation of GaN, both in-situ and ex-situ, and the growth of gadolinium oxide, Gd 2O 3, by Gas source molecular beam epitaxy (GSMBE) have been investigated. Ex-situ cleaning techniques included wet chemical etching and UV-ozone treatments to remove surface contaminants and the native oxide. In-situ cleaning consisted of thermal treatment with and without exposure to an electron cyclotron resonance (ECR) oxygen plasma. A GaN (1x3) streaky RHEED pattern was the final product of this surface treatment study. Various growth initiation techniques were explored to produce Gd 2O 3 films with different microstructures as evidenced by RHEED, TEM, and XRD. Gd 2O 3 films planarized the initial GaN surface and stoichiometry was maintained over a range of substrate temperatures (300° to 650°C). Single crystal gadolinium oxide films were grown at substrate temperatures of 600-650°C. These films exhibited a breakdown field strength (E BD) of ∼1MV/cm, and showed high leakage current at high forward bias due to defects within the oxide. Single crystal oxide films were found to be thermally stable at annealing temperatures up to 1000°C. Quasi-amorphous films were grown at a substrate temperature of 100°C. These films exhibited a higher E BD of ∼3MV/cm and an interface state density of 3 × 10 11 cm −2eV −1. However, the quasi-amorphous films were not thermally stable at 1000°C, showing evidence of re-crystallization in x-ray diffraction (XRD) scans.
A generalized method for deriving the space-domain Green's function in a shielded, multilayer substrate structure with applications to MIS slow-wave transmission lines

An efficient technique for deriving the space-domain Green's function due to an arbitrarily oriented current in shielded, multilayer substrate structures is presented. The derived Green's function is then used to find the dispersion characteristics of single and symmetric coupled line MIS slow-wave structures. These results are compared to published theoretical and experimental data to verify the theory. >
Metabolic alterations in the fetal hepatic and umbilical circulations during glucocorticoid-induced parturition in sheep

Fetal hepatic amino acid metabolism has unique features in comparison to postnatal life. Thus, it seemed likely that this metabolism might be changed by the endocrine changes which precede birth. To explore the changes in placental and fetal carbohydrate and amino acid metabolism that occur during parturition, labor was induced in six ewes at 131 ± 1 d gestation with a fetal infusion of dexamethasone. For purpose of chemical analysis, blood was withdrawn before and approximately 3 and 25 h from the start of the infusion from maternal arterial, uterine venous, umbilical venous, fetal arterial, and left hepatic venous catheters. Fetal oxygenation remained normal. At 25 h, both fetal and maternal arterial plasma glucose concentrations increased(p < 0.01 and p < 0.02, respectively) and umbilical glucose uptake decreased (p < 0.05). Fetal glutamate showed a significant reduction in its hepatic output (p < 0.05) with a concomitant reduction in fetal arterial plasma concentration (p < 0.05) and placental uptake (p < 0.01). Fetal plasma concentrations of several other amino acids were markedly increased. The reduction in placental glutamate uptake was temporally associated with a decline in progesterone release by the pregnant uterus. These data suggest the hypothesis that glutamate plays a role in integrating the complex changes in placental and fetal hepatic metabolism that occur during parturition.
Strong-Field Magnetoresistance of Impurity Conduction in n-Type Germanium

A simple theory is given of the strong-field magnetoresistance in the phonon-induced hopping region of impurity conduction in $n$-type germanium. It is shown to be convenient to consider separately the effect of a magnetic field in three cases: the weak, the moderately strong, and the extremely strong field case. In a moderately strong field the shrinking of a donor wave function and the phase difference produced by the magnetic field between two neighboring donors lead to a formula qualitatively identical with the empirical formula found experimentally by Sladek and Keyes. The magnetoresistance in an extremely strong magnetic field is also discussed, in which the wave function in the plane perpendicular to the field becomes similar to the free-electron wave function in a magnetic field.
Spirituality of Healing Touch Participants

Nurses and nonnurses involved in Healing Touch training were studied to determine if there was a difference in their perception of spirituality. There was no difference between the nurses and nonnurses on either the Spiritual Perspective Scale (F = .001, p = .970) or the Questionnaire on Spiritual and Religious Attitudes (F = .024, p = .878). There was a significant difference between the six levels of training in Healing Touch classes completed by the participants on the Spiritual Perspective Scale (F = 7.079, p = .000). The upper-level classes had higher scores than the lower levels. There was a difference on the Questionnaire on Spiritual and Religious Attitudes between levels of instruction completed (F = 3.326, p = .003). This suggests that there is a heightened sense of spiritual awareness in those in the higher levels of the program. It may be that involvement in an energy-based therapy is one way to develop spiritual awareness.
Gender and economics; Islam and Polygamy - a question of causality

Beginning by contrasting and comparing the fields of (feminist) anthropology and economics, this essay is a response to parts of Barbara Bergmann's article, “Becker's Theory of the Family: Preposterous Conclusions.” In attempting to expose the fallacies in Becker's discussion of the altruism of polygamous families, Bergmann stereotypes polygamous families and conflates Muslims and polygamous societies in the process. Further, she assumes oppression, arguing that most women in the polygamous families (i.e., Muslims) under discussion have an “abysmal status.” This essay argues for acknowledging our social location as researchers, not overgeneralizing about highly diverse societies and the varieties and experiences of women's lives, not assuming oppression, and viewing neither Islam nor polygamy as necessarily central determinants of the conditions of women's lives. Qualitative and quantitative examples of variations in African, Asian, and Middle Eastern women's lives are given – intersecting Muslim/non- Mus...
Effects of soil-applied lead on seedling growth and ectomycorrhizal colonization of loblolly pine

Six-month-old loblolly pine (Pinus taeda) were grown for 15 weeks in two native soils amended with 0, 30, 60, 120, 240 or 480 mg kg−1 Pb as PbCl2. Ectomycorrhizae were quantified, by morphotype, as the total number of tips per centimeter, and as the number of tips for each morphotype and for Cenococcum geophilum. Total numbers of non-ectomycorrhizal short roots and necrotic tips were recorded. Total height and biomass exhibited a non-linear response to soil-applied lead. Growth generally was greatest in the controls and higher treatments, and least in the intermediate treatments. In both soils, Pb concentrations in roots increased linearly with increasing levels of soil-applied Pb. Neither foliage nor stems exhibited significant increases in Pb concentrations with increasing levels of Pb. Significant linear decreases in total numbers of ectomycorrhizal tips and significant linear increases in non-ectomycorrhizal short roots and necrotic tips occurred with increasing levels of Pb in the soil. The majority of individual morphotypes decreased with increasing Pb. However, the number of ectomycorrhizal tips formed by C. geophilium increased with increasing soil Pb levels after 15 weeks of treatment. These results indicate that short-term loblolly pine seedling growth is not inhibited by increasing Pb levels. Ectomycorrhizal formation decreased, and alterations in species composition occurred as a result of increasing concentrations of soil-applied Pb. These effects on ectomycorrhizae may cause long-term changes in nutrient and water balances, which could reduce tree vigor.
Thermo- and pH-Responsive Hydrogel-Coated Gold Nanoparticles

This article describes the structural and optical properties of a new class of hybrid nanoparticles that consists of a small gold core (∼60 nm in diameter) coated with a biocompatible hydrogel polymer shell varying from ∼20 to ∼90 nm in thickness. These nanoparticles are being developed to serve as unique drug-delivery vehicles that have the ability to respond to ambient changes in pH and/or temperature. A particularly attractive feature of these nanoparticles derives from the fact that the hydrogel can be thermally activated by exposure to light via exploitation of the strong plasmon absorption of the gold nanoparticle core. The hydrogel coating consists of a known biocompatible thermo-responsive copolymer derived from the radical polymerization of a selected mixture of N-isoproprylacrylamide and acrylic acid. The morphology and elemental composition of the composite nanoparticles were characterized by field emission scanning electron microscopy and energy-dispersive X-ray scattering, respectively. The o...
Coupled theoretical and experimental analysis of surface coverage effects in Pt-catalyzed NO and O2 reaction to NO2 on Pt(1 1 1)

Abstract Batch reactor results and analysis are reported for the reaction of NO with O2 to form NO2 over a Pt(1 1 1) single crystal at atmospheric pressure. The apparent activation energy and NO, O2, and NO2 reaction orders are found to be 80 kJ mol−1, 1.3, 1, and −2 and are comparable to previous studies on supported Pt catalysts which take inhibition by the product NO2 into account. The absolute rates on a per Pt atom basis are the highest yet reported 0.34 ± 0.02 s−1, at 300 °C, 73 ppm NO, 27 ppm NO2 and 5% O2. Auger electron spectroscopy and X-ray photoelectron spectroscopy are used to show that the surface chemisorbed oxygen coverage under reaction conditions is 0.76 ± 0.06 ML, consistent with a coverage controlled by NO2 dissociation. DFT calculations are used to compare the stability of possible surface intermediates on a clean Pt(1 1 1) surface with those on a p(√3 × √3)-2O (2/3 ML) ordering surface. In contrast to the clean surface, O2 adsorption and dissociation are endothermic at 2/3 ML oxygen, but a peroxynitrite intermediate OONO* is slightly stable and may provide an alternative, associative pathway to NO2 formation that is consistent with the observed first order reaction kinetics in O2.
Examination techniques and therapeutic regimens for the ruminant and camelid eye.

A step-wise procedure and necessary equipment for examination of the ruminant and camelid eye are detailed. Restraint techniques and usage of local anesthetics to facilitate examination are described. Common examination findings and their significance are discussed. Finally, therapeutic options for keratoconjunctivitis and uveitis are explored. A complete ocular examination of ruminants is often not performed in the field because of lack of time, lack of appropriate facilities, and/or lack of equipment. Although individual ophthalmic examinations are not frequently performed as part of a herd health program, they can be of value in select cases. Ocular manifestations of systemic diseases may assist the clinician in establishing a diagnosis on the farm and for little additional cost. For patients with a specific ocular complaint, a complete ophthalmic examination is critical. After completion of the examination and arrival at a diagnosis, one must also be cognizant of the therapeutic regimens that are appropriate for use in ruminants, particularly animals that may be used for meat or milk.
Mediators of fibrosis and apoptosis in obstructive uropathies

Upper urinary tract obstruction, regardless of its cause, often poses a significant clinical challenge to the urologist. Renal cellular and molecular events that occur in response to upper urinary tract obstruction result in a progressive and permanent loss in renal function when left untreated. These pathologic changes include the development of renal fibrosis, tubular atrophy, interstitial inflammation, and apoptotic renal cell death. Several cytokines and growth factors have been identified as major contributors to obstruction-induced renal fibrosis and apoptotic cell death, most notably transforming growth factor-β1 (TGF-β1), angiotensin, nuclear factor-κB (NF-κB), and tumor necrosis factor-α (TNF-α). This review examines the challenges of upper urinary tract obstruction and the role of these mediators in obstruction-induced renal injury.
Cross-Sectional versus Longitudinal Associations of Lean and Fat Mass with pQCT Bone Outcomes in Children

Context: Cross-sectional associations for lean mass (LM) and fat mass (FM) with bone may not reflect longitudinal associations. Objective: Cross-sectional and longitudinal associations of LM and FM with radial bone measurements in children were compared. Design and Participants: We conducted a longitudinal study on 370 (232 females) children, 8–18 yr of age. Main Outcome Measures: LM and FM were measured by dual-energy absorptiometry. Peripheral quantitative computed tomography at the 4% radius (4R) and 20% radius (20R) measured bone mineral content (BMC), volumetric bone mineral density (vBMD), area, and strength [polar stress strain index (pSSI)]. Results: Males at 20R had negative FM cross-sectional and longitudinal associations with cortical area and BMC and pSSI (P < 0.02); negative cross-sectional association with total area (P < 0.001); and negative longitudinal association with cortical thickness (P < 0.001). Females at 20R had FM cross-sectional association with total area, cortical BMC, and pSSI...
Site of protonation and bifunctional group interactions in α,ω‐hydroxyalkylamines

Chemical ionization mass spectrometry and mass analyzed ion kinetic energy spectrometry in conjunction with collision induced dissociation are used to study the fragmentation behavior of a series of α,ω-hydroxyalkylamines. The difference between the ionic population present at equilibrium in the source, and that which is sampled under nonequilibrium conditions, is revealed in the striking differences observed in product distributions in the chemical ionization mass spectra and the mass analyzed ion kinetic energy spectra. The major fragmentations in the mass analyzed ion kinetic energy spectra, loss of NH3 and H2O, show large variations in intensity as a function of the chain length between the hydroxy and amino functionalities. These results are rationalized through analysis of the relevant thermochemical data.
Computational tradeoffs under bounded resources

Over the nearly fifty years of research in Artificial Intelligence, investigators have continued to highlight the computational hardness of implementing core competencies associated with intelligence. Key pillars of AI, including search, constraint propagation, belief updating, learning, decision making, and the associated real-world challenges of planning, perception, natural language understanding, speech recognition, and automated conversation continue to make salient the omnipresent wall of computational hardness. Early pioneers in AI research, including Allen Newell and Herbert Simon, established a long tradition of battling obvious intractabilities by resorting to approximations that relied on heuristic procedures—informal policies that appeared to perform acceptably on subsets of real-world problems. Bounded rationality was conceived and popularized in the context of sample applications that relied on such heuristic procedures to struggle through overwhelming complexity. In the mid-1980s, several researchers began to pursue a line of research aimed at better understanding and formalizing tradeoffs under bounded representational and computational resources. During this time, a palpable shift in perspective occurred with regard to tackling resource limitations. Rather than viewing scarce resources as an unfortunate impediment, foiling at every turn attempts to perform automated problem solving on realistic challenges, investigators began to consider tradeoffs under scarce resources as a rich arena for focused AI research. Passionate researchers suggested that elusive principles of intelligence might actually be founded in developing a deeper understanding of how systems might grapple, in an implicit or explicit resource aware manner, with scarce, varying, or uncertain time and memory resources. Beyond computational resources, the interaction of limited resources and constraints associated with fixed problem-solving architectures were explored. Older, informal notions of bounded rationality soon gave way to richer, more comprehensive approaches to rational computational and real-world actions that incorporate considerations of resource costs and constraints.
EPR of hydroxylamine oxidoreductase from Nitrosomonas europaea

Abstract EPR spectra are reported for the multiheme enzyme hydroxylamine oxidoreductase of Nitrosomonas europaea. Signals arising from several different types of low-spin ( S = 1 2 ) ferric heme were observed in the resting (oxidized) enzyme, but no evidence was obtained for high-spin ( S = 5 2 ) heme, copper or iron-sulfur centers. While overlap of the low-spin heme signals at X-band frequency complicates complete assignment of g values, four species with low field peaks at g 3.4, 3.1, 3.0 and 2.7 were clearly resolved. Complete reduction of the enzyme with sodium dithionite abolished all major signals. Partial reduction of the enzyme by hydroxylamine caused disappearance of signals at g 3.1, g 2.22 and g 1.35 indicating selective reduction of this low-spin component by the substrate.
Crossover scaling functions for exchange anisotropy

The crossover behavior of the susceptibilities ${\ensuremath{\chi}}^{\ensuremath{\alpha}\ensuremath{\alpha}}$ of spin systems with anisotropic exchange coupling is discussed on the basis of an "extended" scaling hypothesis which gives ${\ensuremath{\chi}}^{\ensuremath{\alpha}\ensuremath{\alpha}}(T,g)\ensuremath{\approx}A{t}^{\ensuremath{-}\ensuremath{\gamma}}{X}_{\ensuremath{\alpha}}(\frac{Bg}{{t}^{\ensuremath{\varphi}}})$, where $g$ is the anisotropy parameter, $t=\frac{(T\ensuremath{-}{T}_{c0})}{{T}_{c0}}$, with ${T}_{c0}$ and $\ensuremath{\gamma}$ being the iso tropic critical temperature, and susceptibility exponent, while $A$ and $B$ are model-dependent amplitudes. Analysis of high-temperature series expansions for ${\ensuremath{\chi}}^{\ensuremath{\alpha}\ensuremath{\alpha}}(T,g)$ as polynomials in $g$ for rhombic and axial anisotropy in the fcc, bcc, and simple cubic classical Heisenberg ($n=3$) and classical $XY$ and planar-spin models ($N=2$), verifies the scaling with crossover exponents $\ensuremath{\varphi}=1.25\ifmmode\pm\else\textpm\fi{}0.015$ ($n=3$) and $\ensuremath{\varphi}=1.175\ifmmode\pm\else\textpm\fi{}0.015$ ($n=2$). The universality of the scaling functions ${X}_{\ensuremath{\alpha}}(x)$ is demonstrated both for small $x$ and in the anisotropic limit $T\ensuremath{\rightarrow}{T}_{c}(g)$, where $x\ensuremath{\rightarrow}\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{x}$; for $n=3$, accurate representations are constructed in the form ${X}_{\ensuremath{\alpha}}(x)\ensuremath{\simeq}{P}_{\ensuremath{\alpha}}(\frac{x}{\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{x}}){(1\ensuremath{-}\frac{x}{\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{x}})}^{\ensuremath{-}\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{\ensuremath{\gamma}}}$, where $\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{\ensuremath{\gamma}}$ is the anisotropic susceptibility exponent, while ${P}_{\ensuremath{\alpha}}(z)$ varies smoothly from ${P}_{\ensuremath{\alpha}}(0)=1$ to ${P}_{\ensuremath{\alpha}}(1)\ensuremath{\simeq}1.10$.
Using DIALOG as a book selection tool

Abstract Several databases offered by the DIALOG system were used to locate book reviews in the fields of mathematics, chemistry and computer science; in the first two fields, specific topics were of particular interest. The writer, who has little expertise in these fields, believes that the cost of the searches is worthwhile, inasmuch as he was provided with an essentially complete list of books recently published on the topics of interest and with listings or evaluations of their contents. The DIALOG searches were considered to be more thorough than a manual search would have been, and were much faster than a manual search.
Epidemiology of dementia in Rochester, Minnesota.

Objective To present the results of several retrospective epidemiologic studies of dementia in Rochester, Minnesota. Material and Methods These studies were done by using the medical records-linkage resources of the Rochester Epidemiology Project. Results The incidence and prevalence of dementia increase sharply with advancing age. No difference is noted in overall age-adjusted incidence rates by gender. Rochester studies provide the only 25-year time trend analyses of the incidence of dementia in the United States. Time trends over three prevalence dates indicate an increase in prevalence in this community. Survival is decreased among patients with dementing illness. Case-control studies of Alzheimer's disease (AD) show that general medical conditions, previous head injury, thyroid disease, exposure to therapeutic radiation, anesthesia, and blood transfusion are generally not risk factors for AD. Patients with depression may have an increased risk for the development of AD. Sociodemographic factors such as education, occupation, marital status, and type of dwelling were not significantly different among patients with AD and their age-and gender-matched control subjects. Conclusion The Rochester Epidemiology Project has proved to be an excellent resource for the study of the incidence, prevalence, and risk factors for dementia.
Absolute Hydration Free Energy of the Proton from First-Principles Electronic Structure Calculations

The absolute hydration free energy of the proton, ΔGhyd298(H+), is one of the fundamental quantities for the thermodynamics of aqueous systems. Its exact value remains unknown despite extensive experimental and computational efforts. We report a first-principles determination of ΔGhyd298(H+) by using the latest developments in electronic structure theory including solvation effects. High level ab initio calculations have been performed with a supermolecule-continuum approach based on a recently developed self-consistent reaction field model known as surface and volume polarization for electrostatic interaction (SVPE) or fully polarizable continuum model (FPCM). In the supermolecule-continuum approach, part of the solvent surrounding the solute is treated quantum mechanically and the remaining bulk solvent is approximated by a dielectric continuum medium. With this approach, the calculated results can systematically be improved by increasing the number of quantum mechanically treated solvent molecules. ΔGh...
Kinetic isotope effects in hydroxylation reactions effected by cytochrome P450 compounds I implicate multiple electrophilic oxidants for P450-catalyzed oxidations.

Kinetic isotope effects were measured for oxidations of (S,S)-2-(p-trifluoromethylphenyl)cyclopropylmethane containing zero, two, and three deuterium atoms on the methyl group by Compounds I from t...
Comparative metabolomic analysis of an alternative biosynthetic pathway to pseudosugars in Actinosynnema mirum DSM 43827.

Through a combination of genome mining, gene knockouts, and comparative metabolomic studies, a new biosynthetic pathway to validoxylamine A has been discovered in Actinosynnema mirum DSM 43827. The study revealed the rich diversity of biosynthetic pathways to pseudosugar-containing natural products.
Aerosol black carbon measurements in the Arctic haze during AGASP-II

During the second Arctic Gas and Aerosol Sampling Program conducted in April 1986, we performed measurements of the optically absorbing carbonaceous component of the ambient aerosol from the NOAA WP-3D aircraft operating between sea level and 10 km altitude. We collected the aerosol of filters that were exposed for several hours; we also operated the aethalometer to measure the concentration of aerosol black carbon in real time. The filter analyses represent averages over the altitude range and time span during which the filter was collecting. The real-time results were sorted by altitude to calculate vertical profiles of black carbon concentration. Values typically ranged from 300 to 500 ng m−3 at lower altitudes, decreasing gradually to 25 to 100 ng m−3 at 8–10 km. Strong stratification at lower altitudes was frequently observed. The magnitude of these concentrations suggests that the sources are distant regions of considerable fuel consumption. The presence of this material in the tropospheric column and its probable deposition to the high-albedo surface may result in perturbations of the solar radiation balance. The concentrations measured at the highest altitudes may mean that particulate carbon and accompanying emissions for which it is a tracer are mixing into the stratosphere.
Planning and Integrating Deception into Computer Security Defenses

Deceptive techniques played a prominent role in many human conflicts throughout history. Digital conflicts are no different as the use of deception has found its way to computing since at least the 1980s. However, many computer defenses that use deception were ad-hoc attempts to incorporate deceptive elements. In this paper, we present a model that can be used to plan and integrate deception in computer security defenses. We present an overview of fundamental reasons why deception works and the essential principles involved in using such techniques. We investigate the unique advantages deception-based mechanisms bring to traditional computer security defenses. Furthermore, we show how our model can be used to incorporate deception in many part of computer systems and discuss how we can use such techniques effectively. A successful deception should present plausible alternative(s) to the truth and these should be designed to exploit specific adversaries' biases. We investigate these biases and discuss how can they be used by presenting a number of examples.
Distributed architectures for pen-based input and diagram recognition

We present a system supporting pen-based input and diagram recognition that employs a personal digital assistant (PDA) as an intelligent input device for the system. Functionality is distributed between the PDA and the main computer, with the PDA performing low-level shape recognition and editing functions, and the back-end computer performing high-level recognition functions, including recognition of spatial relations between picture elements. This organization provides a number of advantages over conventional pen-based systems employing simple digitizing tablets. It provides the opportunity to use hardware specially designed for shape recognition and editing in a general diagram recognition system, it allows for improved performance through parallel processing, and it allows diagram entry to be performed remotely through use of the PDA front end in the field, with recognized shapes subsequently downloaded to the main diagram recognizer. We discuss the overall organization of the system, as well as the individual pieces and the communication between them, and describe two ongoing projects employing this architecture.