cssi/SciSciGPT-SciSciNet huggingface dataset:
Increasing ferromagnetic resonance frequency using lamination and shape

The magnetic permeability frequency spectrum is one of the most critical properties for the operation of high frequency magnetic devices in the gigahertz regime. Permeability is fairly constant up to the ferromagnetic resonance (FMR) frequency, at which point the relative permeability drops to unity. Extending FMR to higher frequencies is thus imperative for developing GHz-range magnetic devices. The simulation and experimental investigations presented in this paper demonstrate how stacking layers to form a laminated film increases the FMR frequency by allowing flux closure between layers along the induced easy-axis direction. This flux closure reduces the demagnetization factor along the easy-axis direction by two orders of magnitude. This effect, however, is only observable in patterned films where the shape anisotropy is enough to result in variation of the FMR frequency. Experiments using patterned magnetic cores were performed to illustrate this effect. Through detailed investigation of the permeability spectra of both single layer and laminated CoTaZr magnetic films patterned into 500 μm × L films (where L ranged from 200 μm to 1000 μm), the FMR frequency was extracted and proven to increase as a result of lamination. The degree to which the frequency is boosted by lamination increases exponentially as the length of the film is decreased. Through a combination of lamination and shape demagnetization, the effective anisotropy, which directly relates to FMR frequency, was shown to increase by about 100%.
Biochemical characterization of atherosclerotic plaque constituents using FTIR spectroscopy and histology.

The behavior of vulnerable atherosclerotic plaques is believed to be closely related to plaque composition. There is a need for an effective in vivo technique for examining plaque constituent properties. In this study, Fourier transform infrared spectroscopy using attenuated total reflectance (FTIR-ATR) was used to assess and analyze the biochemical properties of human atherosclerotic plaques. FTIR spectra clearly revealed prominent spectral features corresponding to plaque constituents of interest: the 2930 cm−1 and 2850 cm−1 peaks (indicating the presence of lipids), the 1730 cm−1 peak (lipid esters), the 1550 cm−1 and 1650 cm−1 peaks (fibrous tissues), and the 1100–1000 cm−1 broad phosphate peak (calcification). Spectral data examined on a qualitative basis correlated well with both gross tissue anatomy and histologic features. Gross spatial mappings of tissue sections of both lipidic and calcified plaques were performed. Spectra from various regions of the plaques demonstrated the evolution of lipid peaks, fibrous tissue peaks, and the phosphate calcification band within the plaques. Histologic analysis corroborated the spectral findings in this study. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 197–206, 2003
Robust moveout without velocity picking

At every point in a CMP gather, a local estimate of RMS velocity is: V 2 R M S D x t d x dt , where dt=d x is the local stepout. We form a median stack of these local velocity estimates to obtain stable estimates of RMS velocity without the conventional need to form many hyperbolic stacks.
Infant feeding and infant health in American Samoa.

This study examines the association between infant feeding patterns and health for 6,267 Samoan children born between 1976 and 1982, and represented in the Well Baby Clinic records at the LBJ Tropical Medical Center, American Samoa. The visits to the clinic were aggregated by trimester of age during the first year of life. For each trimester, the principal source of milk was determined, and the children were categorized as breast-fed if they were taking only breast milk, bottle-fed if they were getting no breast milk, or mixed-fed if they were getting both breast milk and milk from other sources. Symptoms and complaints noted in the records were assigned to ICD categories. Associations between source of milk and disease category were analyzed. The Samoan infants were found to be quite healthy for a tropical developing population, as evidenced by both growth in weight and length, as well as by frequency of illnesses. The most common specific disease category, aside from miscellaneous symptoms, was ICD 8, respiratory problems. Gastrointestinal diseases were rare for a developing area. There was an association between source of milk and illness (yes/no) for both the second and third trimesters. In both cases breast-fed infants were healthier than the mixed-fed infants, and during the second trimester the contrast was significant with bottle-fed infants also. When examined by ICD category, breast-fed infants tended to be less likely to have problems in any of the categories, but the only significant differences were between mixed-fed (lower prevalence) and bottle-fed infants during the first trimester for ICD 3, primarily nutritional problems; and for breast-fed (lower prevalence) and mixed-fed infants for ICD 9, digestive problems. These findings highlight the need for additional household work to delineate associations with the growth and health of Samoan infants.
Narragansett Basin Argillite: Lithology, Chronology, and Prehistoric Tool Manufacture:

This article examines the use of one low-grade raw material, Narragansett Basin argillite, by prehistoric peoples in southeastern New England. Petrographic sections analyzed by Dr. Dan Murray (Geologist, University of Rhode Island) have provided a detailed account of the lithology of this material. Rock formation processes and lithic sources are also discussed. Artifact analysis has provided data pertaining to the prehistoric periods when Narragansett Basin argillite was most often used by prehistoric populations in Rhode Island and southeastern Massachusetts. An examination of tool manufacturing techniques has brought to light striking similarities between argillite and quartz Small Stemmed points further supporting the hypothesis of an in situ development of the Small Stemmed Point tradition in New England.
Sensitivity of somatic mutations in human umbilical cord blood to maternal environments

To assess the potential effect of maternal environments on human embryonic/fecal somatic mutation, we measured the frequencies of hypoxanthine-guanine phosphoribosyltransferase (HPRT, hprt gene), mutant T lymphocytes (M{sub f}) and glycophorin A (GPA) variant erythrocytes (V{sub f}) of both allele-loss ({phi}/N) and allele-loss-and duplication (N/N) phenotypes in umbilical cord blood. The mean hprt M{sub F} were significantly lower than those previously reported for adult populations. In addition, the hprt M{sub f} was significantly higher than that of a published study of newborn cord blood samples from a geographically distant population (0.64 {+-} 0.41 x 10{sup -6}, N = 45, P < 0.01; t test, P < 0.01, Mann-Whitney U test). An examination of the demographic data from these two populations led to the sampling of 10 additional newborns specifically matched to the published study for maternal socioeconomic status. The hprt M{sub f} (0.70 {+-} 0.49 x 10{sup -6}) of this selected population was consistent with the published report and significantly lower than that of our initial population (P < 0.03, t test; P < 0.01, Mann-Whitney U test). These results indicate that there is an environmental effect related to maternal socioeconomic status of the frequency of embryonic/fetal somatic mutations. Molecular analysesmore » of hprt mutants from this cohort with elevated M{sub f} revealed a significant decrease in the relative contribution of gross structural mutations to the overall M{sub f} (25 of 38, 66% vs. 34 of 41, 83%, P = 0.024, {chi}{sup 2} test), suggesting that the higher M{sub f} resulted from an elevated level of {open_quotes}point{close_quotes} mutations. No individual maternal demographic or environmental factor was identified as contributing more significantly than any other factor to the observed variability in hprt M{sub f} or GPA V{sub f}. 43 refs., 4 tabs.« less
Reflections on teaching discrete math for the first time

Teaching a class for the first time is always a challenge. Add to the new experience a team-teaching approach and a professor teaching outside of his comfort zone, and things get even more complicated. In this article we evaluate our team-teaching of Discrete Math to computer science majors at the United States Military Academy. We share the aspects of the course that we think were successful as well as those that we would alter the next time around. This article should help any instructor as he/she prepares to teach a new course, particularly one in discrete mathematics.
DFW microburst model based on AA-539 data

Analysis of the August 2, 1985 crash for an L-1011 jumbo jet (DL-191) on approach to the Dallas-Ft. Worth International Airport (DFW) in a thunderstorm indicates that the severe windshear microburst that caused the crash was composed not only of a strong downflow and outflow but also included several large-scale vortex rings entrained in the flowfield. This paper presents a detailed two-dimensional model of the DFW microburst based on data from the MD-80 (AA-539) that followed behind DL-191 and flew through the microburst about two minutes after the crash of DL-191. The model was developed using wind-vector and flight-path data reconstructed by NASA Ames Research Center and a combination of interactive graphics and least-squares error best fit between the modeled and measured wind vectors along the AA-539 flight path. The model indicates that the flowfield contains some significant elements and vortices not previously reported. The alternating direction of rotation of the vortices in the model suggests a microburst structure based on a von Karman vortex street rather than on a Kelvin-Helmholtz instability. The model also indicates that the reconstructed wind-vector data contain a time lag of at least one second in the horizontal winds.
Partitioning of F between H2O and CO2 fluids and topaz rhyolite melt - Implications for mineralizing magmatic-hydrothermal fluids in F-rich granitic systems

Fluid/melt distribution coefficients for F have been determined in experiments conducted with peraluminous topaz rhyolite melts and fluids consisting of H2O and H2O+CO2 at pressures of 0.5 to 5 kbar, temperatures of 775°–1000°C, and concentrations of F in the melt ranging from 0.5 to 6.9 wt%. The major element, F, and Cl concentrations of the starting material and run product glasses were determined by electron microprobe, and the concentration of F in the fluid was calculated by mass balance. The H2O concentrations of some run product glasses were determined by ion microprobe (SIMS). The solubility of melt in the fluid phase increases with increasing F in the system; the solubility of H2O in the melt is independent of the F concentration of the system with up to 6.3 wt% F in the melt. No evidence of immiscible silica- and fluoriderich liquids was detected in the hydrous but water-undersaturated starting material glasses (≦8.5 wt% F in melt) or in the water-saturated run product glasses. F concentrates in topaz rhyolite melts relative to coexisting fluids at most conditions studied; however, DF (wt% F in fluid/wt% F in melt) increases strongly with increasing F in the system. Maximum values of DF in this study are significantly larger than those previously reported in the literature. Linear extrapolation of the data suggests that DF is greater than one for water-saturated, peraluminous granitic melts containing ≧8 wt% F at 800° C and 2 kbar. DF increases as temperature and as (H2O/H2O+CO2) of the fluid increase. For topaz rhyolite melts containing ≦1 wt% F and with H2O-rich fluids, DF is independent of changes in pressure from 2 to 5 kbar at 800° C; for melts containing ≦1 wt% F and in equilibrium with CO2-bearing fluids the concentrations of F in fluid increases with increasing pressure. F-and lithophile element-enriched granites may evolve to compositions containing extreme concentrations of F during the final stages of crystallization. If F in the melt exceeds 8 wt%, DF is greater than one and the associated magmatic-hydrothermal fluid contains >4 molal F. Such F-enriched fluids may be important in the mass transport of ore constituents, i.e., F, Mo, W, Sn, Li, Be, Rb, Cs, U, Th, Nb, Ta, and B, from the magma.
The economic costs of a nuclear moratorium

Abstract Although the present average cost of generating electricity from nuclear reactors is less than the average cost of power from fossil fuel plants, the pressures for additional regulatory controls on nuclear power plants raise the possibility that nuclear power might become unavailable as an energy alternative. With the help of a model of U.S. interfuel competition developed at SRI, implications of various alternative assumptions about the future availability of nuclear power are examined. The economic costs of a nuclear moratorium are evaluated for two different forecasts of energy-demand growth. The impacts of a nuclear moratorium on coal-production levels and petroleum imports are examined. Although the loss of the nuclear option is offset by a substantial increase in eastern and western coal production, the net present cost of this replacement—more than $100 billion—is substantial.
Lack of effect of naloxone on autoanalgesia.

Abstract Autoanalgesia (behaviorally-induced antinociception) may be elicited by acute stress or classically conditioned fear. Antinociception within both of these paradigms is reportedly associated with increased CNS opioid peptide activity. Large doses of naloxone (20 mg/kg) failed to modify antinociception elicited by acute footshock or conditioned fear in rats. Naloxone (4 mg/kg) was also ineffective against antinociception following footshock in mice. These data suggest that if an endorphin does mediate autoanalgesia, the affinity of its receptor for naloxone is very low. Alternatively, parallel opioid and non-opioid systems may be activated by autoanalgesic procedures, with antagonism of the opioid component being insufficient to reduce the antinociception.
Whole life asset management maximising the lifecycle value of infrastructure assets

Infrastructure represent very valuable national assets. Shutdown of infrastructure systems, even for a few hours, can result in significant disruption to service, economic losses and reputational damage.
Sedimentologic and dynamic differences between hot and cold laharic debris flows of Mayon Volcano, Philippines

Numerous hot lahars produced during and immediately after the 1984 eruption of Mayon Volcano, along with frequent cold lahars of the succeeding wet-monsoon seasons, have left widespread debris-flow deposits. Fresh deposits of hot debris flows have thin crusts that are remarkably resistant to erosion and to vegetal growth; these crusts contain clasts with uniform thermoremanent magnetization directions, rare soft-sediment deformation structures, and gas-escape tubes. Deposits of unchannelized hot and cold debris flows both have sheetlike or lobate geometry, non-erosional bases, poor sorting, relatively minor silt and only traces of clay-sized ash, either matrix or clast support, and common out-sized clasts at their tops. It is difficult to distinguish between the deposits after burial, but they have subtle, significant sedimentologic differences. The inversely graded bases of hot debris-flow deposits are thick, suggesting a lack of cohesion and considerable dispersive pressure; they have long clast axes aligned parallel to bedding due to strongly sheared laminar flow, and generally they are succeeded by gradual normal grading from waning-flow conditions. In cold debris-flow beds, only the basal few centimeters may be inversely graded, the bulk being commonly ungraded, indicating the active role of cohesive forces. In the hot flows, vaporization of water by heat from large clasts may have facilitated mobility by decreasing internal friction. Indirect velocity calculations indicate that they moved faster and traveled farther than did cold flows. Proximal hot debris flows were all supercritical, with Froude numbers decreasing enroute. The most distal hot debris flows and all of the cold ones were subcritical. Cold debris flows show no correlation between Froude number and distance of transport.
Adaptive speed term based on homogeneity for level-set segmentation

We tested on an edge map computed from a local homogeneity measurement, which is a potential replacement for the traditional gradient-based edge map in level-set segmentation. In existing level-set methods, the gradient information is used as a stopping criteria for curve evolution, and also provides the attracting force to the zero level-set from the target boundary. However, in a discrete implementation, the gradient-based term can never fully stop the level-set evolution even for ideal edges, leakage is often unavoidable. Also the effective distance of the attracting force and blurring of edges become a trade-off in choosing the shape and support of the smoothing filter. The proposed homogeneity measurement provides easier and more robust edge estimation, and the possibility of fully stopping the level-set evolution. The homogeneity term decreasing from a homogenous region to the boundary, which dramatically increases the effective distance of the attracting force and also provides additional measurement of the overall approximation to the target boundary. Therefore, it provides a reliable criteria of adaptively changing the advent speed. By using this term, the leakage problem was avoided effectively in most cases compared to traditional level-set methods. The computation of the homogeneity is fast and its extension to the 3D case is straightforward.
CD34 Staining Density as a Diagnostic Test for Predicting Giant Cell Clinical Behavior

Purpose: While aggressive and nonaggressive giant cell lesions (GCLs) of the jaws can be differentiated based on clinical and radiographic characteristics, their histologic appearances are indistinguishable. Our group has identified CD34, a cell adhesion marker found in hematopoietic precursor and endothelial cells, as a possible biomarker of GCL clinical behavior. In a retrospective study, CD34 staining density was more than two times higher in aggressive compared to nonaggressive GCLs.1 The purpose of this study was to answer the clinical question: “Among patients with GCLs, does CD34 staining density predict phenotype?” Methods: Using retrospective study design, a cohort composed of patients with GCLs treated at Massachusetts General Hospital between 1992–2006 were enrolled. The primary predictor variable was GCL clinical behavior (aggressive versus non-aggressive). GCLs were classified as aggressive if they were 5 cm in size, recurred after treatment or showed three of the following radiographic signs: root resorption, tooth displacement, cortical bone thinning or perforation. 2 The outcome measure was the average CD34 staining density of GCL tissue. Different CD34 levels were evaluated as possible thresholds for a positive diagnostic test using a receiver-operator characteristic curve. Based on this curve, a CD34 staining density of 2.5% was selected as being positive for aggressive GCLs. Lesions with CD34 levels 2.5% were classified as nonaggressive GCLs. Secondary predictor variables were age and sex. Bivariate analyses were computed to evaluate the association between CD34 staining density and the primary and secondary predictors. Predictors with p 0.15 in bivariate analyses were included in a multiple logistic regression model, which was used to evaluate the association between the clinical behavior and a positive test (CD34 2.5%), after controlling for confounders/effect modifiers. For all analyses, a p-value 0.05 was considered statistically significant. Results: The study sample consisted of 32 subjects with a mean age of 24.4 19.8 years (range 2-83), including 23 females (71.8 percent), who were treated for giant cell lesions during the study period. There were 26 aggressive lesions and 6 non-aggressive lesions, with mean CD34 staining densities of 5.1 3.3% and 2.2 0.65%, respectively (p 0.02). Using a threshold CD34 staining level of 2.5% as indicative of a positive test, the sensitivity, specificity, positive and negative predictive values were 0.74, 0.75, 0.89 and 0.50, respectively. In the logistic regression model, clinical behavior was statistically significantly associated with a positive test; aggressive lesions were 16.7 times more likely to have a CD34 level 2.5% when compared to non-aggressive lesions (95% CI: 1.6, 172; p 0.02). Conclusions: The results of this study suggest that CD34 staining density levels are good predictors giant cell clinical behavior, with levels 2.5% strongly associated with aggressive lesions.
Progress of analog/hybrid computation

Solid-state circuits and the integrated circuits succeeding them are improving analog-computing-element reliability by an order of magnitude, speed by two orders of magnitude, and still reducing system cost. The effects of integrated-circuit technology on the price, reliability, and sophistication of digital computers are even more pronounced, and the resulting system-design tradeoffs shape the future course of hybrid-computer techniques. This review article discusses the design of fast analog/hybrid computer systems, including recent developments in integrated operational amplifiers, electronic mode-control switches, digital attenuators, and new packaging techniques.
Metachronous seeding of lymph node metastases in rats bearing the MT-100-TC mammary carcinoma: the effect of elective lymph node dissection.

Following the introduction of cancer cells into the lymphatic system, metastases in ‘down-stream’ lymph nodes often appear in a sequential manner. This could be due to synchronous seeding of the in-line nodes with progressively diminishing numbers of tumorigenic cancer cells, or alternatively, by discrete, stepwise (metachronous) seeding of ‘down-stream’ nodes by ‘up-stream’ nodal metastases acting as ‘generalizing’ sites. Metachronous seeding to local lymph nodes is potentially curable by elective lymph node dissection; synchronous seeding is not.
Body stability and muscle and motor cortex activity during walking with wide stance

Biomechanical and neural mechanisms of balance control during walking are still poorly understood. In this study, we examined the body dynamic stability, activity of limb muscles, and activity of m...
Variation in the Application of the “Promiscuous Female” Stereotype and the Nature of the Application Domain: Influences on Sexual Harassment Judgments after Exposure to the Jerry Springer Show

This study was designed to explore how the impact of exposure to a few stereotyped group members can be mediated by individual variation in stereotype application to other group members. When compared to participants exposed to nonpromiscuous women on an episode of the Jerry Springer Show, those exposed to promiscuous women perceived a victim of sexual harassment as less traumatized and more responsible for the event. In addition, exposure condition had no impact on judgments when the man physically touched the victim. Conversely, when he made a verbal comment or verbal request, those in the promiscuous condition reported perceptions of less victim trauma and made greater attributions of victim responsibility. The findings also indicate that the effects of exposure to the promiscuous woman depictions were mediated by individual variation in attributions of victim promiscuity. Finally, activation of the promiscuous female stereotype was also shown to have generalized to judgments of women in a nonsexual domain.
Shoot, I'm Sorry: An Examination of Narrative Functions and Effectiveness within Dick Cheney's Hunting Accident Apologia

Although narrative is established as a critical part of human communication, recent typologies of apologia have neglected to account for its prominence. In this essay, I argue that narrative is not just a decorative strategy but rather an essential component within successful apologia when a negative action cannot be denied outright. Well-designed narratives are central to effective apologia statements for several reasons: First, humans are storytellers by nature; second, narratives are uniquely suited to providing explanations for behavior; and third, the framing and identification functions of narrative within apologia are quite powerful. Narratives function as a framing device that can shape the facts of the story and create a deeper sense of identification with the audience. To illuminate these arguments, the essay turns to the case of Dick Cheney's apologia after accidentally shooting a hunting partner.
When chasing your tail saves time

On explique pourquoi l'evaluation en temps d'un programme fonctionnel depend de la representation des expressions recursives par des structures de donnees cycliques
A Converse Lyapunov Theorem and Robustness for Asymptotic Stability in Probability

A converse Lyapunov theorem is established for discrete-time stochastic systems with non-unique solutions. In particular, it is shown that global asymptotic stability in probability implies the existence of a continuous Lyapunov function, smooth outside of the attractor, that decreases in expected value along solutions. The keys to this result are mild regularity conditions imposed on the set-valued mapping that characterizes the update of the system state, and the ensuing robustness of global asymptotic stability in probability to sufficiently small state-dependent perturbations.
Adaptive digital techniques for audio noise cancellation

Discusses two adaptive digital techniques for audio noise cancellation. The first technique, adaptive predictive deconvolution, uses an adaptive linear predictor to estimate and cancel (time) correlated noise components on an audio signal. The second technique, adaptive filtering, employs two audio signal inputs, the first having the desired audio signal along with noise and the second sensing principally the noise. The second, noise signal is adaptively filtered and subtracted from the first signal cancelling noise components common to the two inputs. A stand-alone digital signal processor has been developed to carry out these two noise cancellation techniques. This automatic digital audio processor, ADAP, carries out these processes in real time with up to a 256th order digital filter.
Effects of semantic elaboration and typicality on picture naming in Alzheimer disease.

Abstract Purpose Individuals with probable Alzheimer disease (pAD) are frequently impaired at picture naming. This study examined whether a semantic elaboration task would facilitate naming in pAD, and whether training either semantically typical or atypical stimulus items facilitated generalized improvement in picture naming and category generation tasks. Methods Twelve adults with mild-moderate pAD participated in the study. Participants performed an experimental semantic elaboration training task using a subset of typical items from one category and atypical items from another category. The third category, acted as a control (i.e., no items were trained). The study assessed change in category generation and a picture naming within the three target categories. Results Individuals showed significantly improved category generation and naming, but changes were not limited to trained categories. Naming of trained atypical items improved significantly. Participants showed significantly improved naming of untrained typical items from categories trained with typical items. Conclusions Semantic elaboration of typical items within a semantic category can lead to generalized improvement in other typical items in the category in mild-moderate pAD. This is consistent with theories postulating that typical category items share overlapping distributed representations. Further exploration of the effects of semantic elaboration on word-finding in pAD is warranted, especially the possibility of within-category generalization. Learning outcomes: After reading this article, the reader will be able to: (1) explain how word-finding is affected by probable Alzheimer disease; (2) identify ways word finding is usually assessed in Alzheimer's disease; (3) describe the effects of training typical versus atypical items from a category in people with aphasia; and (4) describe the effects of training people with Alzheimer's disease on typical versus atypical items from a category.
Imaging near-contact transport in the planar-collector geometry for a Schottky contact on high-purity GaAs

Variable temperature electron beam induced current (EBIC) and cathodoluminescence (CL) were combined to image electric fields and charge transport for a Schottky contact on high purity epitaxial GaAs in the planar-collector geometry. Simultaneous EBIC and CL imaging proves that the near-contact EBIC signal is dominated by depletion effects, even in material where the bulk diffusion length greatly exceeds the intercontact distance. In forward bias, an EBIC dipole is observed, providing direct spatial indication of the transition between drift and diffusion transport of locally generated charge.
Conformationally locked nucleoside analogues. Synthesis of dideoxycarbocyclic nucleoside analogues structurally related to neplanocin C

The glycon moiety of nucleosides in solution is known to exist in a rapid dynamic equilibrium between extreme northern and southern conformations as defined by the pseudorotation cycle. The concept of preparing rigid nucleoside analogues with the glycon conformation locked in one of these two extremes was tested with the synthesis of some cyclopropane-fused dideoxycarbocyclic nucleosides, similar to the well-known class of anti-HIV active dideoxynucleosides. The new compounds described here are dideoxynucleoside analogues of the fermentation product neplanocin C (6) which exhibits a typical northern geometry for its 6-oxabicyclo[3.1.0]hexane pseudosugar moiety. However, in view of the lability of the epoxide ring in this system, the equivalent cyclopropane-fused bicyclo[3.1.0]hexane system was used instead to prepare the corresponding dideoxynucleoside analogues bearing all the common bases [(+/-)-9-13]. Due to the well-documented preference of unrestricted bicyclo[3.1.0]hexane systems to exist exclusively in a boat conformation, the resulting nucleosides are structurally locked in a typical northern conformation similar to that of neplanocin C. The locked northern conformation in these nucleosides remained unchanged in solution in the 20-80 degrees C temperature range according to variable temperature 1H NMR studies. For the synthesis of these compounds, racemic trans-1-[(benzyloxy)methyl]-4-hydroxybicyclo[3.1.0]hexane [(+/-)-18] was prepared by a samarium-promoted cyclopropanation reaction with the antecedent cyclopentenol. All of the bases were incorporated under Mitsunobu conditions and converted to the desired final products following a standard methodology. Anti-HIV evaluation revealed that only the adenosine analogue (+/-)-9 possessed enough activity to warrant resolution into its optical antipodes. This was realized by chiral HPLC chromatography to give the individual enantiomers (-)-32 and (+)-33. Adenosine deaminase was used to identify isomer (+)-33 as the enantiomer with the "natural" configuration which was solely responsible for the observed biological activity and toxicity of (+/-)-9. It is possible that the exclusive northern conformation adopted by these nucleosides reduces their substrate affinity for the various activating kinases, except in the case of the adenosine analogue.
Noble gases in carbonaceous chondrites

Carbonaceous chondrites noble gases measurement by mass spectroscopy, discussing compositional trends and origins
Sertraline pharmacokinetics and dynamics in adolescents.

ABSTRACT Objective To determine the pharmacokinetics of sertraline in adolescents and assess its effect on a surrogate marker of serotonin transport. Method Pharmacokinetic parameters of a single 50-mg dose of sertraline were determined in 10 adolescents. Steady-state withdrawal kinetics were determined in 12 adolescents taking 50 mg/day and in 6 adolescents taking 100 to 150 mg/day. Platelet serotonin reuptake was measured before and after 2 weeks of daily 50-mg dosing. Results The mean steady-state half-life of 50 mg was significantly shorter (15.3 ± 3.5 hours) than the single-dose half-life (26.7 ± 5.2 hours; t = 6.4, p t = 2.9, p = .01). Platelet serotonin reuptake was inhibited by 61 ± 15% after approximately 2 weeks of sertraline 50 mg/day. Conclusions The half-life of sertraline 50 mg becomes significantly shorter from the initial dose to steady-state, and many adolescents may benefit from twice-per-day dosing. The steady-state half-life increases as the dose increases. The moderate levels of platelet reuptake inhibition at 50 mg/day indicate that most adolescents may need sertraline doses higher than 50 mg/day to attain a therapeutic response.
Cephaloridine-induced biochemical changes and cytotoxicity in suspensions of rabbit isolated proximal tubules

Abstract Cephalosporin antibiotics, such as cephaloridine (Cld), are known to be nephrotoxic in vivo and in vitro. In vivo , Cld causes proximal tubule necrosis in rabbits which is preceded by glutathione (GSH) depletion and, under certain conditions, inhibition of mitochondrial function. In vitro , Cld causes GSH depletion, lipid peroxidation, and inhibition of rat kidney slice organic ion uptake. The present investigations were designed to evaluate the temporal relationships of the biochemical “lesions” caused by Cld to the onset of lethal cell injury in suspensions of isolated rabbit proximal tubules. Cld was cytotoxic to suspensions of rabbit proximal tubules (EC50 = 1.10 ± 0.33 m m ) in the absence of amino acids (to support GSH synthesis). In this model, Cld also caused GSH and ATP depletion, lipid peroxidation (malondialdehyde formation), and inhibition of tubule respiration. Probenecid prevented Cld accumulation, tubule injury, ATP depletion, and lipid peroxidation and markedly attenuated the GSH depletion. Addition of glycine, cystine, and glutamate to the incubation buffer to support GSH synthesis decreased the tubule accumulation of Cld (due solely to the presence of glutamate) and blocked Cld-induced tubule lethality, lipid peroxidation, ATP depletion, and GSH depletion. Glycine or glutamate alone had no effect on Cld-induced cytotoxicity, whereas cystine was cytoprotective. Buthionine sulfoximine partially reversed the amino acid protection against Cld-induced tubule injury. Thus amino acid-induced protection of tubules from Cld cytotoxicity was due to the combination of a high intracellular GSH content and cytoprotection by cystine. The antioxidant N-N′ -diphenyl- p -phenylenediamine (DPPD) blocked tubule injury, ATP depletion, and lipid peroxidation but had no effect on Cld-induced GSH depletion when tubules were incubated for 3 hr. However, when incubations were allowed to run for up to 8 hr, DPPD had no effect on Cld cytoxicity, despite continued inhibition of lipid peroxidation. These data demonstrate that Cld-induced tubule injury in short-term (3 hr) incubations in vitro occurs by a mechanism probably involving lipid peroxidation and occurs only in the absence of amino acids to support GSH synthesis. Inhibition of tubule respiration and ATP depletion could not clearly be causally linked to the onset of cell death in this model. The mechanism of the peroxidation-independent Cld toxicity in tubules incubated for 8 hr or longer is not known at this time.
Private dental and prescription-drug coverage in children: data from the medical expenditure panel survey.

Objective.—Most studies on health insurance have examined primarily basic medical insurance coverage; few have looked at supplemental insurance and/or dental-insurance coverage. Prescription-drug and dental-insurance coverage are becoming increasingly important due to continued increase in health care costs and changes in cost-sharing structure of health plans. This study examined prescription-drug coverage and dental-insurance coverage in the context of overall insurance coverage. Method.—This study utilized the Household Component File from the 2000 Medical Expenditure Panel Survey (MEPS), a national survey on medical care conducted by the Agency for Healthcare Research and Quality (AHRQ). Univariate and bivariate analyses were performed to provide estimates on children's prescription-drug and dental-insurance coverage. Multivariate logistic regression analyses were conducted to identify demographic and socioeconomic factors that influence coverage. Results.—In 2000, 68.5% of US children had private insurance, 22.2% had public insurance, and 9.3% were uninsured. Among children with private insurance, only 56.9% had dental-insurance coverage and 76.3% had prescription-drug coverage. Family income level, maternal education, and race were significant predictors of dental insurance and prescription-drug coverage. Conclusion.—Although significant strides have been made to insure US children, a large percentage of children still do not have comprehensive coverage. Even among privately insured children, many are without dental or prescription-drug coverage. Those who were poor, minority, and with low maternal education had lower likelihood of dental and prescription-drug coverage.
Driving and flying with epilepsy

Transportation issues in industrialized nations play an important role in the lives of most citizens. The acts of flying and driving, especially in the United States, intersect with many peoples’ lives on almost a daily basis. Although some larger cities have modern and efficient public transportation systems, many do not, thus placing considerable responsibility on the individual to manage their own transportation needs. A person with epilepsy faces considerable challenges when it comes to transportation. Defining these challenges and understanding how to deal with the person with epilepsy and transportation issues is the focus of this article.
On gauge fields – string duality as an integrable system

Abstract We show that the equations of an immersion of a minimal surface into the constant negative curvature space of dimensions 3 and 5 are integrable, in the sense that those equations admit a Lax pair representation with a spectral parameter. Minimal surfaces in the constant negative curvature space are classical solutions for the equations of motion of a string theory with the constant negative curvature target space. We compare the variational calculus of surfaces and of holonomy functionals in the Yang–Mills theory.
Weighted leaf AVL-trees

A new data structure called a weighted leaf AVL-tree is presented for representing a collection of weighted items drawn from a totally ordered set. It is shown that using this data structure, the average access time of an item is optimal to within a constant factor while the worst-case access time is “logarithmic.” The data structure is a generalization of a leaf AVL-tree to the weighted-item case and retains its restructuring simplicity. It is shown that the data structure supports a number of update operations in a simple and worst-case efficient manner.
Radiative equilibrium of a gray medium in a rectangular enclosure

Abstract Radiative equilibrium temperature distributions are calculated for an absorbing-emitting gray medium enclosed by rectangular walls of different temperatures. A “modified differential approximation” is used to obtain an approximate solution, which compares favorably with direct numerical computations carried out using a zonal method.
Mechanisms of persistence of low numbers of bacteria preyed upon by protozoa

Abstract Tetrahymena pyriformis cultures were maintained when transferred serially in solutions containing 10 5 to 10 7 Klebsiella pneumoniae cells.ml −1 , bacterial numbers that were observed to persist in the presence of protozoa. The number of cells of one strain of K. pneumoniae surviving predation in solution was essentially the same in the absence of an alternative prey as in the presence of a second K. pneumoniae strain. Toxins deleterious to protozoa did not appear as the animal consumed the bacteria. T. pyriformis reduced the abundance of Escherichia coli from about 10 8 to 10 6 .ml −1 . but the latter number persisted for 15 days; however, in solutions containing chloramphenicol, the abundance of E. coli fell to 590 cells. ml −1 in 15 days. In solutions containing the antibiotic, T. pyriformis reduced the Rhizobium sp. population from more than 10 6 to less than 10 3 cells in 10 days and K. pneumoniae from more than 10 8 .ml −1 to zero in 18 days. An appreciable decline in abundance of these bacteria did not occur in the antibiotic-amended liquid free of protozoa. T. pyriformis did not greatly reduce Rhizobium sp. numbers when both were added to irradiated soil, but the predator caused the bacterial population to decline from 4 × 10 8 to fewer than 10 5 .g −1 in 16 days in chloramphenicol-treated soil. Colpoda sp. inoculated with Rhizobium sp. into soil sterilized by autoclaving only reduced the prey abundance from 10 9 to 10 8 .g −1 , but the protozoan caused the bacterial population to fall to about 100.g −1 in 15 days in the presence of the antibiotic. The population of Rhizobium sp. added to nonsterile soil dropped from in excess of 10 8 to 6 × 10 6 .g −1 in 29 days. but it declined to 550. g −1 in the same period when chloramphenicol was also introduced. It is concluded that the ability of these bacteria to maintain themselves in solution and in soil is governed by their capacity to reproduce and replace the cells consumed by predation.
Implicit sexual portrayals in the movies: Interpretations of young women

In this study I explored how young women make interpretations about the implicit portion (i.e., the fade‐to‐black part) of an implicit sex act portrayed in an R‐rated movie clip. Undergraduate women (N = 39) were interviewed about their interpretations of an implicit sexual portrayal from a movie clip. Viewers used a variety of sexual schemata and scripts to interpret the sexual episode. For inferences regarding sexual intercourse, viewers mostly relied on their observations of sequences of verbal / behavior events that seemed to indicate that sexual intercourse had happened. For judgments about safer sexual behaviors, viewers tended to rely more on generalizations regarding personalities, goals, relationships, situations, and sexual behavior in real life and in the movies than on their observations of verbal/behavioral events. The results are discussed in terms of their implications for future media research in sexuality.
The solar wind-magnetosphere energy coupling and magnetospheric disturbances

Energy coupling between the solar wind and the magnetosphere is examined and the influence of this coupling on magnetospheric disturbances is discussed. Following a review of the components of the total energy production rate of the magnetosphere and progress in the study of solar wind-magnetosphere correlations, the derivation of the solar wind-magnetosphere energy coupling function, which has been found to correlate well with the total magnetospheric energy production rate, is presented. Examination of the relations between the energy coupling function and the type of magnetic disturbance with which it is associated indicates that magnetic storms with a large sudden storm commencement and a weak main phase are associated with small energy coupling, while values of the coupling function greater than 5 x 10 to the 18th to 10 to the 19th erg/sec are required for the development of a major geomagnetic storm. The magnetospheric substorm is shown to be a direct result of increased solar wind-magnetosphere energy coupling rather than the sudden conversion of stored magnetic energy. Finally, it is indicated that at energy couplings greater than 10 to the 19th erg/sec, the positive feedback process responsible for substorms breaks down, resulting in the abnormal growth of the ring current.
Supporting synthesis in geovisualization

Geovisualization tools are intended to support analysts in complex task domains like crisis management, disease surveillance, and threat analysis. It is likely that analysts in these domains will use geovisualizations to develop many analytical results over time. This calls for attention to the problem of collecting, organizing, and making sense out of groups of analytical results-a stage of analysis called synthesis. The research reported here aims to characterize the process of synthesis as it is conducted by analysts working alone, and to suggest design guidelines for new tools to support synthesis in that setting. We have developed a new experimental method for observing and characterizing the process of synthesis. This approach has participants work with a collection of physical data artifacts on a paper-covered workspace to devise hypotheses under the guise of a disease outbreak scenario. From experiment video recordings we identified and coded actions that participants undertook to complete the synthesis task. In this article we report results from synthesis experiments with analysts from Pacific Northwest National Laboratory and experts from The Pennsylvania State University. Experiment results are then distilled into a design framework that can be used to shape the development of geovisual synthesis tools.
Zinc Toxicity Thresholds for Reclamation Forb Species

Zinc toxicity thresholds for reclamation plants are largely unknown. As a result, ecological risk assessments often rely on toxicity thresholds for agronomic species, which may differ from those of restoration species. Our objective was to provide Zn toxicity thresholds for forb species that are commonly used in reclamation activities. We used a greenhouse screening study where seedlings of yarrow (Achillea millefolium L.), Bigelow's tansyaster (Machaeranthera bigelovii (Gray) Greene var. bigelovii), blue flax (Linum perenne L. var. Appar), alfalfa (Medicago sativa L. var. Ladak), Palmer's penstemon (Penstemon palmeri Gray), and Rocky Mountain penstemon (Penstemon strictus Benth. var. Bandera) were grown in sand culture and exposed to increasing concentrations of Zn. Lethal concentrations (LC50 – substrate Zn concentration resulting in 50% mortality), effective concentrations (EC50 – substrate Zn concentration resulting in 50% biomass reduction), and phytotoxicity thresholds (PT50 – tissue Zn concentration resulting in 50% biomass reduction) were then determined. Phytotoxicity thresholds and effective concentrations for these reclamation species were relatively consistent between species. Our estimates of PT50-shoot for these species range from 1258 to 3214 mg Zn kg−1 . Measures of EC50-plant for these restoration forbs ranged from 82 to 214 mg Zn L−1 . These thresholds might be more useful for risk assessors working on reclamation sites than those based on non-reclamation species that are widely used.