cssi/SciSciGPT-SciSciNet huggingface dataset:
Diffraction managed solitons: asymptotic validity and excitation thresholds

Solitons in discrete optical systems have been a topic of keen interest over the past decade. In a diffraction managed waveguide array, where the waveguide's diffraction profile is varied periodically in the direction of propagation, the slow evolution of the electric field envelope is modelled by a nonlocal discrete equation that exhibits soliton solutions numerically. In this paper, we verify the validity of the asymptotic approximation, demonstrating that solutions of the averaged equation are close in the l2 sense to those of the original model for long time scales. Moreover, we prove that the averaged equation has stable ground state solutions, complementing previous experimental and numerical observations. Finally, we show that for a generalization of the averaged equation, ground states of an associated Hamiltonian exist if and only if their l2 norm exceeds a certain excitation threshold, which depends on the system's dimension and degree of nonlinearity.
Relationships among grocery nutrition label users and consumers’ attitudes and behavior toward restaurant menu labeling

In the United States (US), based on the 2010 Affordable Care Act, restaurant chains and similar retail food establishments with 20 or more locations are required to begin implementing calorie information on their menus. As enacting of the law begins, it is important to understand its potential for improving consumers' healthful behaviors. Therefore, the objective of this study was to explore relationships among users of grocery nutrition labels and attitudes toward restaurant menu labeling, along with the caloric content of their restaurant menu selection. Study participants were surveyed and then provided identical mock restaurant menus with or without calories. Results found that participants who used grocery nutrition labels and believed they would make healthy menu selections with nutrition labels on restaurant menus made healthier menu selections, regardless of whether the menu displayed calories or not. Consumers' nutrition knowledge and behaviors gained from using grocery nutrition labels and consumers' desire for restaurants to provide nutrition menu labels have a positive effect on their choosing healthful restaurant menu items.
Bone Resorption and Humoral Hypercalcemia of Malignancy: Stimulation of Bone Resorption in Vitro by Tumor Extracts is Inhibited by Prostaglandin Synthesis Inhibitors*

Extracts of tumors from patients with humoral hypercalcemia of malignancy (HHM) were tested using an in vitro bone resorption assay in order to investigate the pathogenesis of the hypercalcemia. Bone resorption was assessed by comparing the percent release of previously incorporated 45Cafrom paired halves of newborn mouse calvaria. Saline extracts of three out of five tumors from HHM patients caused a significant increase in 45Ca release relative to controls. Extracts of liver and non-HHM tumor did not cause significant resorption. Tumorstimulated bone resorption was blocked by indomethacin and eicosatetraynoic acid, inhibitors of the synthesis of prostaglandins (PGs) and related metabolites of arachidonic acid, whereas resorption stimulated by parathyroid hormone (PTH), PGE2, or 1,25-(OH)2D3 was not. Furthermore, levels of immunoreactive PTH or PGE2 in tumor extracts were not sufficient to account for the degree of resorption observed. These observations indicate that PTH or PGE2 are not responsible for ...
A Stepped-Pole Writer to Minimize Side Erasure on Barium Ferrite Tape

Side erasure is investigated for non-oriented and perpendicularly oriented barium ferrite particulate tape media without a soft-underlayer. While notching is efficient to avoid side writing from the leading pole, the perpendicular head fields originating from the outer edge of the trailing pole result in curved transitions and non-negligible side erasure. We find that such side erasure effects can be suppressed by recessing part of the trailing pole, thereby forming a stepped pole. Magnetic force microscopy and cross-track profiling experiments demonstrate the efficacy of this novel stepped-pole writer design to minimize side writing effects in non-oriented and perpendicular particulate tape media. This writer geometry will enable tape recording at 50 ktpi and beyond.
An AES-SIMS study of silicon oxidation induced by ion or electron bombardment

Abstract We have investigated bombardment-induced oxidation of silicon at room temperature in an AES-SIMS system. Most of the results described were obtained by AES. SIMS was used only to reproduce previous work under the conditions of this study. It was found that bombardment of sputter-cleaned silicon with either electrons (2 keV) or argon ions (5–10 keV) at elevated oxygen pressures (up to 10-3 Pa) results in strongly enhanced oxygen uptake and oxidation of silicon, as evidenced by the appearance of a strong ( Si O2)LVV line at ≈78 eV. At base pressure almost complete oxidation can be produced by direct implantation of oxygen (15 keV O+2) at normal incidence, whereas O+2 impact at 45° results in incomplete oxidation. The ( Si O2)LVV intensity increases as the n-th power of the OKLL intensity, where n = 2.4 and 3.7 for argon and oxygen bombardment, respectively. Deviations from the expected growth kinetics (n = 2) are attributed mostly to differences in escape depth of the ( Si O2)LVV and OKLL electrons. Electron impact results in oxide structures similar to those induced by ion impact, the main difference being that the thickness of the altered layer is apparently smaller under electron irradiation. Comparison of AES and SIMS results suggests that the oxygen-induced enhancement of the Si+ intensity is directly related (most likely proportional) to the concentration of SiO2. Oxygen uptake from the ambient has also been investigated by ion-excited AES. It was found that the ion excited Si signals are much less sensitive to variations in the average oxygen content than the respective electron-excited signals. This suggests rapid oxygen emission from the cascade center prior to deexcitation of the collisionally excited Si atom.
Growth ofCururbita maxima L. plants in the presence of the cycloartenol synthase inhibitor U18666A1

Squash, like other Cucurbitaceae, have unique sterol profiles that offer an excellent opportunity to examine the relationship between sterol biosynthesis and plant growth. To determine the effect of sterol biosynthesis inhibition on squash growth, Cucurbita maxima seedlings with and without cotyledons were subjected to increasing concentrations of the cycloartenol synthase (EC 5.4.99.8) inhibitor 3β-(2-diethylaminoethoxy) androstenone (U18666A). Inhibition of shoot growth was concentration-dependent (from 0, 2, 5, 10, and 20 μM); plants with intact cotyledons grew to 26.4, 23.7, 21.6, 20.0, and 15.6 cm, respectively, at the above inhibitor concentrations, compared to 25.5, 19.4, 17.0, 12.0, and 11 cm for plants with severed cotyledons. In plants with severed cotyledons, 10 and 20 μM U18666A caused rapid necrosis of the first two, newly emerged, primary leaves, and halted new leaf formation. Secondary root formation was initially affected at all inhibitor concentrations regardless of whether cotyledons were present or not. Vegetative tissue showed a decrease in the accumulation of the major squash sterol, 7, 22-stigmastadienol, accompanied by increased accumulation of minor sterol components. Sterol profiles in cotyledons were unaltered. The data show that sterols are crucial for maintaining plant growth and viability, but do not address the cotyledonary effect on growth with respect to sterol biosynthesis.
Relationships between the energetics of impulsive and gradual emissions from solar flares

The gradual soft X-ray emissions associated with a homogeneous set of solar flares have been investigated in the context of a thermal model proposed to explain the impulsive components. The parametric techniques which successfully characterized the hard X-ray and microwave observations are employed in an event-by-event analysis to test for quantitative and correlative relationships between the impulsive and gradual emissions. The results of this investigation are consistent with the hypothesis that the hard X-ray and microwave emissions are produced by bulk heating of a common thermal source. The quantitative relationships require an additional source to explain the soft X-ray observations, consistent with previous results. Correlations between the energetics of the impulsive and gradual emissions, identified in the present work, provide the first clear evidence that their energizing mechanisms are related.
Strong Gender Egalitarianism

Perhaps the most intractable aspect of gender inequality concerns inequalities within the family around the domestic division of labor, especially over child care and other forms of caregiving. The...
Influence of erythrocyte velocity on impedance plethysmographic measurements

Impedance plethysmography has been widely used clinically. However, uncertainty exists concerning the source of the impedance signal. The present study was designed to indicate the relative contributions made by blood volume changes and blood flow changes. Anin vitro flow system containing a pulsatile pump, a bovine carotid artery, a rigid tube, and a terminal resis tance was assembled. Impedance recordings were made on both the expansile artery and the rigid tube. The impedance signal from the rigid tube was taken as the flow-related component. The signal from the expansile artery represented the combined effects of volume changes and flow changes. The recordings were made over the full physiological range of pulse pressures and peak flow values, using both normal saline and blood (haematocrit =26±4%). No impedance change was detected in the rigid vessel using saline as the perfusate. When blood was used, the impedance signal from the rigid tube averaged about 10% of that from the expansile vessel and its morphology was different. Changes in erthrocyte velocity produced a small but definite change in the impedance signal recorded from the artery.
Amorphous ribbon formatin and the effects of casting velocity

Abstract Experimental relations between melt puddle length and ribbon thickness in the steady state spin casting of Fe81.5B14.5Si4 amorphous ribbons are analyzed with a continoues casting model to estimated the ribbon formation temperature Tt and the metal-wheel interfacial conductance h. The result Tt ≈ 1000 °C indicates that a high viscosity liquid layer contributes to the final ribbon thickness about as much as the amorphous solid layer defined by the isotherm Tg = 450 °C. It is also shown that Tt remains constant but that h increases from 12 to 50 cal cm−2 s−1 K−1 with increasing wheel speed. The improved h value at higher casting speeds results from better melt-wheel contact as revealed in the contact pattern on the wheel-side surface of the ribbons.
Acquisition of a novel behavior induces higher levels of Arc mRNA than does overtrained performance.

Abstract Arc (also termed activity-regulated cytoskeleton-associated protein or Arg3.1), is an effector immediate early gene whose upregulation has been demonstrated during events of synaptic plasticity. In the present study, the possibility that Arc would be specifically upregulated in rats during the acquisition of a quickly learned behavioral task but not in overtrained animals was investigated. Three groups of rats, pseudotrained, newly trained and overtrained, were examined with respect to Arc expression following training on a simple operant lever-pressing task. Newly trained animals were killed 30 min following the session in which they demonstrated acquisition of the task, and overtrained animals were trained on the same task for 13–14 days and then killed. Relative to base level measures taken 6 h following the session, all three groups demonstrated significant levels of induction of Arc mRNA; however, newly trained animals exhibited heightened induction of Arc mRNA relative to both pseudotrained and overtrained animals. The increased levels of Arc mRNA in newly trained animals were located in the CA1 and CA3 fields of hippocampus, the subiculum, and the anterior cingulate, piriform, infra/prelimbic, perirhinal and entorhinal cortical areas. Additionally, Arc mRNA was expressed differentially across the above anatomic structures in a relative pattern that was the same in all three groups. Finally, levels of Arc mRNA in specific brain regions of newly trained animals correlated negatively with the rate of task acquisition, such that slow learners exhibited higher levels of Arc mRNA than fast learners. From these results we suggest that Arc is upregulated in an experience-dependent manner, with higher levels of induction occurring during the initial stage of learning. Furthermore, the finding of increased Arc levels in slow versus fast learners indicates that Arc expression may be associated with the length of time required to: (1) form new associations or (2) remodel existing connections. These results confirm other reports that Arc is a critical substrate for the synaptic plasticity underlying the acquisition of new behaviors.
A fast response magnetic servo amplifier

IN SERVOMECHANISMS used in military applications, one of the weakest links is the electronic amplifier. The electronic amplifier is undesirable primarily because of its fragility, maintenance requirements, low power efficiency, and often objectionable warm-up time. The magnetic amplifier is much more rugged, has a much longer life, has a greater power efficiency, requires much less maintenance, and has no warm-up time. Thus, one of the most obvious and potentially fruitful applications of magnetic amplifiers is in the control of 2-phase motors in servomechanisms.
Fetal and Neonatal Cardiac Tumors

Primary tumors of the heart are uncommon in the fetus and neonate. Nevertheless, the widespread use of new imaging techniques has contributed significantly to earlier diagnosis, treatment, and thus improved survival. The clinical findings, imaging studies, pathology, and outcome of 224 fetuses and neonates with cardiac tumors collected from the literature are evaluated and discussed. Most tumors are benign, and of these rhabdomyoma is the most common, followed by teratoma, fibroma, oncocytic cardiomyopathy, vascular tumors, and myxoma. Malignant and metastatic tumors are described but are rare. Murmurs, arrhythmias, cyanosis, respiratory distress, and cardiac failure are the main presenting signs of cardiac tumors in the perinatal period. Disturbances in hemodynamic function are correlated with the size and location of the tumor. Cardiac vascular tumors have the best outcome, whereas malignant tumors have the worst. The purpose of this review is to concentrate on the fetus and neonate in an attempt to determine the various ways cardiac tumors differ clinically and morphologically in this age group from those occurring in older children and adults and to show that certain types of tumors have a better prognosis than others.
Sociometric choice, visual presence, and game-playing behavior

This study reports the effects of prior patterns of social interaction measured sociometrically, and visual presence upon Ss' cooperative and competitive choice behavior during 100 trials of a Maximizing Difference Game. The results of the present study, which are consistent with prior studies, indicate: (a) “strangers” play to maximize the difference between their own and the other's outcomes more frequently than non-friends who do so more frequently than friends; and (b) the opportunity to view the other player does not affect Ss' choice behavior.
SU‐FF‐T‐60: SPECT‐Guided Radiation Therapy Planning for Yttrium‐90 Microspheres Therapy

Purpose: 90Y based microspheres are used for unresectable liver metastases by selectively transporting the radioactive spheres to the metastases via hepatic‐arteries. This is due to the fact that livertumors receive most of their blood supply from the hepatic‐arteries, while the normal liver receives the blood through the portal‐vein. The microspheres prescription is based on the body surface area and several studies attempted dose‐calculations using MIRD formalism assuming activity distribution is uniform in tumors and liver. In reality, microsphere distribution is not uniform because the radioactivity selectively administered through the hepatic‐artery. In the absence of commercial radiation treatment planning systems for microsphere therapy, it becomes difficult to determine the radiationdose distribution and the dose volume histograms to determine the target coverage and dose‐volume tolerance of normal liver. In this work we have outlined a method based on intensity volume histogram (IVH) determined from 99mTc‐macroaggregated albumin (MAA) SPECT scan. Methods: Both volumetric SPECT/CT scans and contrast‐enhanced CT scan were acquired for the patient. Liver is contoured on both the SPECT/CT and the contrast CT.Tumor is contoured only on the contrast CT. Both scans were then registered in CERR (Computational Environment for Radiotherapy Research). Intensity values of SPECT scan are converted to dose distribution based on their relative intensity values and the assumption that the microspheres would have the same intensity distribution as the MAA scan. Result: DVH is derived from the converted dose distribution and the contoured structures. Administrable activity is adjusted based on the normal liver DVH with an ultimate goal of keeping 800–1000cc of normal liver below 30 Gy. This methodology is also helpful in determining the activity to be delivered incase of retreatment taking into account the previously administered dose to the normal liver.Conclusion: Using DVH of the normal liver administrable activity can be determined
Synaptic Delay and Conduction Time in Brain during Exposure to Simulated High Altitudes

RELATIVELY few techniques are available for the investigation of the long-term effects of physiological variables on conduction times and synaptic delay in the brain. The lateral olfactory tract (LOT) and prepyriform cortex provide a system whereby these parameters may be measured in rats chronically implanted with electrodes1. Fibres of the LOT synapse with dendrites of the prepyriform pyramidal cells2. When the LOT is electrically stimulated by a single shock, both the presynaptic LOT potential and the postsynaptic prepyriform response may be recorded from electrodes placed in the prepyriform cortex (Fig. 1). As the LOT potential first approaches and then invades the recording area, the adjacent cortex acts first as a current source and then as a sink; hence the presynaptic potential is biphasic—first positive, then negative. The time from stimulus artefact to negative crest of the presynaptic potential is a measure of conduction time along the LOT and the time from the negative peak to beginning of the prepyriform response is a measure of synaptic delay (Fig. 1).
Another comment on 'Eccentricity as a vector'

Defining the eccentricity vector as the dimensionless Runge–Lenz vector provides an alternative elementary derivation of the Keplerian polar orbit equation.
Learning assessment of a videoconference-based training: lessons from medical training between USA and Ethiopia

This study looks at videoconference-based training for medical professionals. Four videoconference locations in the USA were connected to a videoconference center in Ethiopia to provide HIV/AIDS training for medical professionals. The training was conducted for 6 weeks. The overall research question guiding this study was: Can videoconferencing serve as an effective medium to facilitate training between high-and low-income countries? The study addresses participants' perception of videoconferencing as a potential training medium. Furthermore, the study explores implications of the training using communities of practice theory. Constraining and promoting factors for videoconferencing were identified from communication media choice and systems analysis and design theories. Survey questionnaires and open-ended questions were used to collect data. The findings show promise for videoconference-based training that can bridge the knowledge gap in low-income countries by linking them with high-income countries. We also found support for communities of practice attributes including access to experts, knowledge transfer, sharing experience, and sense of community. The paper concludes with three lessons learned with implications for research and practice including cultural context, IT infrastructure, and sustainable community of practice.
Characterization of monocarboxylate transport in human kidney HK-2 cells.

The objectives of this study were to characterize the expression and function of monocarboxylate transporters (MCTs) in human kidney HK-2 cells and to compare the expression of MCTs in HK-2 cells to that found in human kidney. mRNA and protein expression of MCTs were determined by RT-PCR and Western analyses, respectively, while immunofluorescence staining was used to determine the membrane localization of MCT1. The driving force, transport kinetics, and inhibition of two MCT substrates, d-lactate and butyrate, were characterized in HK-2 cells. mRNA of MCT1, -2, -3, -4 isoforms were present in HK-2 cells and in human kidney cortex. MCT1 was present predominantly on the basal membranes of HK-2 cells. The cellular uptake of d-lactate and butyrate exhibited pH- and concentration-dependence (d-lactate, Km of 26.5 ± 2.2 mM and Vmax of 72.0 ± 14.5 nmol mg-1 min-1; butyrate, Km of 0.8 ± 0.3 mM, Vmax of 29.3 ± 2.5 nmol mg-1 min-1, and a diffusional clearance of 2.1 μL mg-1 min-1). The uptake of d-lactate and buty...
Tyrosine phosphorylation-dependent activation of NFκB is compromised in T cells from the elderly

NFkappaB induction and gene regulation are compromised in T lymphocytes during aging. This has been attributed to altered proteasomal function resulting in decreased ubiquitin-mediated degradation of IkappaBalpha. However, little is known about the impact of aging on the mechanisms that lead to the release of active NFkappaB employing pro-oxidant pathways. Oxidant-mediated activation of NFkappaB has been previously shown to involve proteasome independent mechanisms and hence may be an important alternate conduit to the induction of this central transcription factor in aging. Employing H(2)O(2) and pervanadate we not only demonstrate lowered tyrosine phosphorylation of IkappaBalpha, but also compromised induction of nuclear NFkappaB in T cells from the elderly. Lowered tyrosine phosphorylation of IkappaBalpha may be due to a decrease in activity of p56(lck) and ZAP-70, since treatment with piceatannol, an inhibitor of syk and src family kinases, mimics age associated decline in tyrosine phosphorylation of IkappaBalpha in T cells from young donors. Thus, alternate pathways of NFkappaB induction are also impaired in T cells from the elderly and may underlie immune-deficit accompanying aging.
Enzymes Catalyzing the Reversible Conversion of Fructose-6-Phosphate and Fructose-1,6-Bisphosphate in Maize (Zea mays L.) Kernels

The significance of the glycolytic and gluconeogenic conversion of fructose-6-phosphate and fructose-1,6-bisphosphate on sugar metabolism was investigated in maize (Zea mays L.) kernels. Maximum extractable activities of the pyrophosphate (PPi) dependent phosphofructokinase, fructose-1,6-bisphosphatase, and the ATP-dependent phosphofructokinase were measured in normal and four maize genotypes, which accumulate relatively more sugars and less starch, to determine how these enzymes are affected by the genetic lesions. Normal endosperm accumulated more dry matter than the high sugar/low starch genotypes, but protein contents did not differ greatly among the genotypes. Mutation of several starch biosynthetic enzymes had little impact on the activities of PPi-dependent phosphofructokinase, fructose-1,6-bisphosphatase, and ATP-dependent phosphofructokinase, despite the altered capacity of the cell to synthesize starch. The PPi-dependent phosphofructokinase appeared to be more active toward glycolysis in all genotypes studied. Activity of the PPi-dependent phosphofructokinase in shrunken (low sucrose synthase genotype) did not differ from the activity in other genotypes, suggesting that the gluconeogenic production of PPi may not be the primary role of the enzyme. As expected, shrunken kernels contained more sugars and less starch than normal kernels throughout kernel development except at the very early stages. Developmental profiles of normal kernels also showed marked changes in the PPi-dependent phosphofructokinase activity, whereas the level of ATP-dependent phosphofructokinase activity remained relatively steady during kernel development. In addition, the ATP-dependent phosphofructokinase, and not the PPi-dependent phosphofructokinase, appeared to correlate more closely with respiration rate. These findings suggest that glycolysis catalyzed by the ATP-dependent phosphofructokinase may serve primarily to support energy production, and glycolysis catalyzed by the PPi-dependent phosphofructokinase may contribute mainly to generation of biosynthetic intermediates.
Synthetic iron-oxo "diamond core" mimics structure of key intermediate in methane monooxygenase catalytic cycle.

Molecular oxygen (O2) is the principal oxidant used by aerobic organisms to carry out a wide range of metabolic reactions and transformations. The enzymes involved in these processes use a rich variety of different active sites to activate O2, such as heme cofactors, mono- and binuclear nonheme iron centers, mono- and binuclear copper complexes, and heteronuclear heme iron/copper clusters (1). Typically, oxygen is activated in a tightly controlled manner to ensure that the formation of the key reactive species in the corresponding catalytic cycle occurs only when the target substrate is present, thereby suppressing potentially harmful side reactions in the enzyme active site (2). A particularly well studied example of an enzyme that follows this general strategy is provided by cytochrome P450 (3). As outlined in Fig. 1 Upper , binding of substrate to the heme-containing active site of cytochrome P450 causes dissociation of the FeIII-bound water ligand, thereby triggering the reduction of the iron center to the reactive FeII state. The FeII species binds and activates O2 to generate an iron(IV)-oxo porphyrin radical intermediate. This highly potent oxidant then proceeds to incorporate one of the O atoms derived from molecular oxygen into a specific C![Graphic][1] H bond of the substrate, in a process that yields the oxidized product and restores the resting FeIII state of the enzyme. High-valent intermediates have also been identified in the catalytic cycles of an increasing number of nonheme diiron enzymes (1, 4), such as methane monooxygenase (MMO) (2, 5). Found in methanotropic bacteria, MMO catalyzes the chemically challenging conversion of methane to methanol (Fig. 1 Lower ), thereby reducing the amount of this greenhouse gas that is being released into the atmosphere by nearly 1 billion tons per year … *E-mail: brunold{at}chem.wisc.edu [1]: /embed/inline-graphic-1.gif
Requirements of State Regulatory Agencies for Monitoring Ground-Water Quality at Waste Disposal Sites

A survey of the requirements of State regulatory agencies responsible for monitoring ground-water quality at waste disposal sites was conducted in order to gain a concise profile of monitoring practices across the country, and also to provide the basis for a monitoring manual to serve as technical background and guidance for the citizens of Minnesota. The survey considered a variety of topics including the regulatory framework for requiring monitoring, chemical parameters analyzed, recommended methods of monitoring well construction and sample collection, laboratory quality control, data interpretation, and post-operational monitoring requirements. The survey showed that most State monitoring programs are in their infancy. Many States, however, are beginning to devote serious effort and manpower commitments to the development of monitoring programs, although there is considerable divergence of opinion regarding how these programs should be conducted. Federal legislation establishing minimum performance criteria instead of detailed operating requirements for waste disposal sites will increase the need for sound water monitoring programs at these sites in the future.
Xenopus transcription factor IIIA (XTFIIIA): after a decade of research

Xenopus transcription factor IIIA (XTFIIIA) is the first eukaryotic transcription factor purified to homogeneity and is specifically required for the 5S RNA gene transcription. It contains two structural domains and nine zinc finger motifs through which it recognizes the promoter region of the 5S RNA gene. It also binds to 5S RNA and serves to store 5S RNA in the form of 7S ribonucleoprotein particles in oocytes. Additionally, it forms a metastable complex with 5S DNA and promotes the formation of stable and competent transcription complexes. Its expression is developmentally controlled at the level of transcription and translation. Moreover, it participates in the assembly of active chromatin templates and at least, in part, is responsible for the developmental regulation of two kinds of 5S RNA genes in Xenopus.
Infrared-infrared double resonance spectroscopy of Ar-HF. Intermolecular state dependence of the dipole moment and vibrational predissociation in vHF = 2

Abstract Stark spectra have been measured for Ar-HF in several intermolecular bending and stretching states associated with v HF = 1. The resulting dipole moments are compared with those calculated using the most recent potential energy surface. Infrared-infrared double resonance spectroscopy is used to access the corresponding states in v HF = 2 where, in the absence of intermolecular excitation, dissociation occurs before the molecules can reach the detector. Simultaneous excitation of the Σ or Π bending vibrations, which have the effect of making the hydrogen atom point away from argon atom on average, results in lifetimes in excess of the molecular flight time (0.3 ms).
Effects of maternal antioxidant supplementation on maternal and fetal antioxidant levels: a randomized, double-blind study.

Abstract Objective We sought to determine whether vitamins C and E could be delivered to the fetal-placental unit through maternal oral supplementation. Study design In a randomized, double-blind study, 20 women received a daily prenatal vitamin with or without 400 IU of vitamin E and 500 mg of vitamin C, starting at 35 weeks' gestation. At randomization, a nutritional questionnaire, plasma vitamin C and E and red blood cell (RBC) vitamin E levels were determined. At delivery, concentrations of maternal and fetal plasma vitamin C and E, maternal and fetal RBC vitamin E, amniotic fluid vitamin C, and chorioamnion vitamin E and tensile strength were determined. Results Maternal plasma vitamin E levels increased in the supplemented women but not in the control subjects. No changes in maternal vitamin C levels were noted. Maternal plasma vitamin C concentrations at delivery correlated closely with amniotic fluid vitamin C levels. Similarly, maternal plasma vitamin E levels at delivery correlated with the chorioamnion concentration of vitamin E. Conclusions Maternal plasma vitamin E levels are increased by oral supplementation. Maternal plasma vitamin C and E concentrations correlate with the concentration of vitamin C in the amniotic fluid and vitamin E in the chorioamnion, respectively.
Developing Model‐Based Reasoning

Key elements of the structure and function of models in mathematics and science are identified. These elements are used as a basis for discussing the development of model‐based reasoning. A microgenetic study examines the beginnings of model‐based reasoning in a pair of fourth‐ and fifth‐grade children who solved several problems about chance and probability. Results are reported in the form of a cognitive model of children's problem‐solving performance. The cognitive model explains a transition in children's reasoning from tacit reliance on empirical regularity to a form of model‐based reasoning. Several factors fostering change in children's thinking are identified, including the role of notations, peer interaction, and teacher assistance. We suggest that model‐based reasoning is a slowly‐developing capability that emerges only with proper contextual and social support and that future study should be carried out in classrooms, where these forms of assistance can also be part of the object of study. Mode...
Toward a theory and method for cooperative systems, with application to auditing

Abstract Cooperative distributed knowledge-base systems—sometime termed distributed artificial Intelligence (DAI)—offer computer methods for coordinating group expertise in the solving of problems. Much of the research to the present has been empirical testing of informal methods. There is a need for more formal methods to guide the design and development of DAI. At the same time, object-oriented programming methods provide a natural means or representing real-world objects in a way that facilitates communication among those objects. In this paper we propose a methodology for integrating formal methods of knowledge theory with object-oriented methods in a way that may facilitate the development of more robust DAI systems. Our exposition takes the reader from conceptual development to fundamentals of an application in auditing.
The effects of crystallization on the microhardness of Fe-22.5Al-10Zr metallic glass ribbons

Mesure de la microdurete de rubans metalliques amorphes d'alliage Fe-Al-Zr a l'etat brut et apres 20mn de recuit a des temperatures variant par intervalles de 100˚C de 200 a 800˚C. Les variations de la microdurete fournissent un excellent moyen d'estimer le degre de cristallisation provoques par les traitements thermiques de recuit. Les implications de ces resultats sur les cinetiques de cristallisation sont discutees.
Radiative lifetime of the b3⩞+ state of CO☆

Abstract The lifetime of the b 3 ⩞ + state of CO was measured at six different pressures; 10, 25, 50, 75, 100, and 125 μ; by observing the decay of the (0, 1), (0, 2), (0, 3), and (0, 4) bands of the 3+ system. No pressure dependence of the lifetime was noted. No variation in lifetime was observed over the above progression of states so that transition moment can be assumed constant for transitions arising from the v ' = 0 level. The measured lifetimes from the (0, 1), (0, 2), (0, 3), and (0, 4) transitions are 57.5±0.9, 57.2±1.0, 58.8±0.7, and 56.9±1.5 nsec, respectively. The average lifetime of the v ' = 0 state was 57.6±1.2 nsec.
Conservation organizations and the option value to preserve: an application to debt-for-nature swaps

Abstract This paper presents an analytical model of the option to preserve environmental goods motivated by the existence of debt-for-nature swaps. Conservation organizations' option value arises from the option to reject or accept the terms of a bargain concerning the exchange of the debt holding of a conservation organization for land preservation. From the resulting closed form solution of the option to preserve, simulations are performed showing the importance of the conservation organization's willingness to pay for preservation and the correlation between the willingness to pay and the value of the asset to be exchanged on the option value.
A kinetic study of the autoxidation of methyl linoleate and linoleic acid emulsions in the presence of sodium chloride

Autoxidation of linoleic acid and methyl linoleate emulsions in aqueous buffer solutions was studied by the rate of oxygen uptake. The oxidation rates of methyl linoleate emulsions increased with an inerease in the pH of the buffer solution. With linoleic acid, oxidation rates rose until the increase reached its peak at pH 5.50 and then decreased gradually to a minimum at pH 8.00.
Unsteady Effects in Flow Rate Measurement at the Entrance of a Pipe

Unsteady flow in pipes and nozzles occur frequently in engineering applications and they pose special problems of measurement and calibration. When the Reynolds number is high the entrance region of a pipe (following a smooth contraction) is characterized by a thin boundary layer and the unsteady effects are then bound up in the unsteady behavior of the boundary layer. Woblesse and Farrell [1]2 have recently considered unsteady effects in laminar pipe entrance flows that start from rest by an integral method. Periodic disturbances also arise which require a different treatment. The primary interest of the present work is for thin entrance boundary layers subject to peridodic disturbances. In either case the ratio of the average velocity to the velocity in the potential core is V[sub]avg/V[sub]core = 1- 2[delta]*/R [equation 1] where [delta]* is the usual displacement thickness and R is the pipe radius. In steady flow this ratio is just the "discharge coefficient", c[sub]d. In unsteady flow it is very desirable to know how this ratio changes with time because many of the presently available experimental methods enable one to measure V[sub]core but not V[sub]avg readily. In this brief note we will estimate the unsteady effects of a periodic, fluctuating main flow on the displacement thickness of a laminar, flat plate boundary layer. It is assumed that the boundary layer is sufficiently thin compared to the radius of a pipe so that the pressure gradient caused by this effect in a pipe can be neglected; the results should then be directly applicable to equation (I).
Progress and challenges in animal handling and slaughter in the U.S.

Abstract Both well-designed equipment and trained employees are required to maintain a high standard of animal welfare during slaughter. When McDonald's Corporation started auditing U.S. beef and pork slaughter plants in 1999, there were great improvements in handling and stunning. They used a numerical objective scoring system. It contained five basic measurements: (1) the percentage of animals stunned on the first attempt, (2) percentage rendered insensible prior to hoisting, (3) percentage vocalizing during handling and stunning, (4) percentage that fall down and (5) percentage moved with an electric goad. Each variable was scored on a simple yes/no basis. Baseline data was collected prior to the McDonald's audits in 1996. The most striking improvements were in beef. The average effective first shot stunning score was 89.5% in 1996, 96.2% in 1999 and 98.6% 5 years later in 2003. The average percentage of cattle vocalizing during stunning and handling was 10% in 1996, 2.4% in 1999 and 2.0% in 2003. A total of 50 plants were audited. Most plants were able to greatly improve welfare by improving stunner maintenance; installing non-slip floor gratings in stun boxes and better training. They also had to make simple, low cost changes to eliminate distractions that cause animals to balk and refuse to move. The most common ways to improve animal movement were: (1) install a lamp on a dark race entrance, (2) move ceiling lamps to eliminate sparkling reflections, (3) muffle air hissing, (4) install shields and solid sides on races to prevent animals from seeing moving people up ahead and (5) eliminate air drafts that blow in the faces of approaching animals. A major remaining problem area is in plants that are not in a program of yearly audits by restaurants. Serious animal abuse has occurred in some of these non-audited plants.
Prevention of brain aging and dementia

The brain is subjected to multiple factors that result in damage to its cellular constituents, the neuron and supporting cells, and the neural networks that form the bases of cognitive ability. Like other systems, the brain has remarkable capacity to repair that damage and to adapt or compensate for the loss of neurons and the disruption of the neural architecture. Brain aging and dementia can be conceptualized as a balance between neuronal injury and repair. This balance can be affected not only by genetic and age-related factors but also by multiple environmental factors. The latter includes many factors, including education, nutrition, exercise, socialization, and stress. As individuals, we have the potential to modify these factors through lifestyle choices. Advances in neuroscience have led to the development of pharmacologic agents that can ameliorate the effects of even genetic (e.g., statins and antihypertensive agents) and age-related (e.g., antioxidants and estrogen replacement) factors. By altering the balance between neuronal injury and repair, we can delay the expression and progression of the neurodegenerative processes of brain aging, AD, and related dementias.
Instantaneous dynamics of the cratonic Congo basin

Understanding the formation mechanisms of cratonic basins provides an examination of the rheological, compositional and thermal properties of continental cratons. However, these mechanisms are poorly understood because there are few currently active cratonic basins. One cratonic basin thought to be active is the Congo basin located in equatorial Africa. The Congo basin is coincident with a large negative free-air gravity anomaly, an anomalous topographic depression, and a large positive upper mantle shear wave velocity anomaly. Localized admittance models show that the gravity anomaly cannot be explained by a flexural support of the topographic depression at the Congo. We analyze these data and show that they can be explained by the depression of the Congo basin by the action of a downward dynamic force on the lithosphere resulting from a high-density object within the lithosphere. We formulate instantaneous dynamic models describing the action of this force on the lithosphere. These models show that the gravity and topography of the Congo basin are explained by viscous support of an anomalously dense region located at 100 km depth within the lithosphere. The density anomaly has a magnitude within the range of 27–60 kg m^−3 and is most likely compositional in origin. Our models do not provide a constraint on the lithospheric viscosity of the Congo craton because the shallow location of the anomaly ensures strong coupling of the anomaly to the surface regardless of viscosity structure.
Oxalate-induced activation of PKC-α and -δ regulates NADPH oxidase-mediated oxidative injury in renal tubular epithelial cells

Oxalate-induced oxidative stress contributes to cell injury and promotes renal deposition of calcium oxalate crystals. However, we do not know how oxalate stimulates reactive oxygen species (ROS) in renal tubular epithelial cells. We investigated the signaling mechanism of oxalate-induced ROS formation in these cells and found that oxalate significantly increased membrane-associated protein kinase C (PKC) activity while at the same time lowering cytosolic PKC activity. Oxalate markedly translocated PKC-α and -δ from the cytosol to the cell membrane. Pretreatment of LLC-PK1 cells with specific inhibitors of PKC-α or -δ significantly blocked oxalate-induced generation of superoxide and hydrogen peroxide along with NADPH oxidase activity, LDH release, lipid hydroperoxide formation, and apoptosis. The PKC activator PMA mimicked oxalate's effect on oxidative stress in LLC-PK1 cells as well as cytosol-to-membrane translocation of PKC-α and -δ. Silencing of PKC-α expression by PKC-α-specific small interfering RNA significantly attenuated oxalate-induced cell injury by decreasing hydrogen peroxide generation and LDH release. We believe this is the first demonstration that PKC-α- and -δ-dependent activation of NADPH oxidase is one of the mechanisms responsible for oxalate-induced oxidative injury in renal tubular epithelial cells. The study suggests that the therapeutic approach might be considered toward attenuating oxalate-induced PKC signaling-mediated oxidative injury in recurrent stone formers.
Uncoupling of endothelial nitric oxide synthase in cerebral vasculature of Tg2576 mice

In this study, we tested the hypothesis that reduced bioavailability of tetrahydrobiopterin (BH4) is a major mechanism responsible for pathogenesis of endothelial dysfunction in cerebral microvessels of transgenic mice expressing the Swedish double mutation of human amyloid precursor protein (APP) (Tg2576 mice). Endothelial nitric oxide synthase (eNOS) protein expression was significantly increased in cerebral vasculature of Tg2576 mice. In contrast, bioavailability of BH4 was significantly reduced (p < 0.05). Moreover, superoxide anion production was increased in cerebral microvessels of Tg2576 mice (p < 0.05). Incubation with NOS inhibitor, Nω-nitro-L-arginine methyl ester, decreased superoxide anion indicating that uncoupled eNOS is most likely the source of superoxide anion. Increasing BH4 bioavailability either exogenously by BH4 supplementation or endogenously by treatment with the selective peroxisome proliferator-activated receptor--delta activator GW501516 (2 mg/kg/day, 14 days) attenuated eNOS uncoupling and decreased superoxide anion production in cerebral microvessels of Tg2576 mice (p < 0.05). Treatment with GW501516 restored the biological activity of endothelial nitric oxide in cerebral microvessels of Tg2576 mice, as indicated by the increased nitrite/nitrate content and 3,5-cyclic guanosine monophosphate levels (p < 0.05). Our studies indicate that sub-optimal BH4 bioavailability in cerebral vasculature is an important contributor to oxidant stress and endothelial dysfunction in Tg2576 mouse model of Alzheimer's disease. Existing evidence suggests that Aβ peptides-induced up-regulation of expression and activity of NADPH oxidase causes increased production of superoxide anion (.O2(-)). .O2(-) can also be converted to hydrogen peroxide (H2O2) by enzymatic activity of superoxide dismutase (SOD) or spontaneous dismutation. Elevation of .O2(-) and H2O2 might cause oxidation of tetrahydrobiopterin (BH4) to dihydrobiopterin (BH2) and subsequent uncoupling of endothelial nitric oxide synthase (eNOS) (a) thus reducing levels of nitric oxide (NO) and 3',5'-cyclic guanosine monophosphate (cGMP). Supplementation of BH4 or activation of PPARδ prevents detrimental effects of eNOS uncoupling by restoring bioavailability of BH4 and scavenging of .O2(-), respectively (b). Activation of PPARδ also increases expression of catalase thereby inactivating H2O2. Generation of H2O2 by uncoupled eNOS in cerebral microvessels of Tg2576 mice is hypothetical.
Exact representation of the second-order moments for resubstitution and leave-one-out error estimation for linear discriminant analysis in the univariate heteroskedastic Gaussian model

This paper provides exact analytical expressions for the bias, variance, and RMS for the resubstitution and leave-one-out error estimators in the case of linear discriminant analysis (LDA) in the univariate heteroskedastic Gaussian model. Neither the variances nor the sample sizes for the two classes need be the same. The generality of heteroskedasticity (unequal variances) is a fundamental feature of the work presented in this paper, which distinguishes it from past work. The expected resubstitution and leave-one-out errors are represented by probabilities involving bivariate Gaussian distributions. Their second moments and cross-moments with the actual error are represented by 3- and 4-variate Gaussian distributions. From these, the bias, deviation variance, and RMS for resubstitution and leave-one-out as estimators of the actual error can be computed. The RMS expressions are applied to the determination of sample size and illustrated in biomarker classification.