cssi/SciSciGPT-SciSciNet huggingface dataset:
EPR of triplet excitions in tetracene crystals: spin polarization and the role of singlet exciton fission

Abstract The room temperature electron paramagnetic resonance spectrum of triplet excitons in single-crystal tetracene is reported. From experiment performed at 24 GHz the exciton spin hamiltonian ≻/sc;* = gβH·S + D* [S2z*→ 1 3 S(S + 1)] + E* [S*→S2v*], is fit to the measured angular dependence in the a'b plane. The spin hamiltonian parameters are g = 2.002,D* = −0.0062 cm−1, and E* = +0.0248 ± 0.0005 cm−1. Extensive spin polarization and emission have been observed and are attributed to the formation of the triplet population from singlet exciton fission.
Surface tension theory of pure liquids and polymer melts

Abstract Using the lattice fluid model in conjunction with the Cahn-Hilliard theory of inhomogeneous systems, an accurate method has been developed for calculating the surface tension of nonpolar and slightly polar liquids of arbitrary molecular weight. For low molecular weight liquids, the surface tension can be computed from the triple point to 0.7 of the gas-liquid critical temperature with an error of less than 5%. The theory is somewhat less accurate for polymer melts because it tends to overestimate the surface entropy. The molecular weight dependence of the surface tension and entropy is closely related to the dependence of liquid density on molecular weight.
Structural Disorder in Expanding the Functionome of Aminoacyl-tRNA Synthetases

Over the past decade, aminoacyl-tRNA synthetases (AARSs) have emerged as a new class of regulatory proteins with widespread functions beyond their classic role in protein synthesis. The functional expansion concurs with the incorporation of new domains and motifs to AARSs and coincides with the emergence of the multi-synthetase complex (MSC) during the course of eukaryotic evolution. Notably, the new domains in AARSs are often found to be structurally disordered or to be linked to the enzyme cores via unstructured linkers. We performed bioinformatic analysis and classified the 20 human cytoplasmic AARSs into three groups based on their propensities for structural disorder. The analysis also suggests that, while the assembly of the MSC mainly involves ordered structural domains, structurally disordered regions play an important role in activating and expanding the regulatory functions of AARSs.
A sweet success for substrate engineering.

Chemically synthesizing complex oligosaccharides remains a significant challenge. Through the addition of hydrophobic appendages to 'unnatural' substrates, some oligosaccharide-forming glycosyltransferases can direct the formation of distinct sugar linkages while maintaining stereoselectivity.
Behavioral cross-sensitization between cocaine and enkephalin in the A10 dopamine region

The motor stimulant effect produced by cocaine and the injection of opioids onto A10 dopamine neurons is thought to be mediated by an increase in dopaminergic transmission in mesolimbic dopamine terminal fields such as the nucleus accumbens. Following daily administration, the behavioral stimulant effect of both cocaine and intra-A10 injection of opioids is augmented. The data in this report demonstrate that rats receiving daily injection of enkephalin analogue into the A10 have an enhanced motor stimulant response to intraperitoneal cocaine, but not to saline. Conversely, rats receiving daily injection of intraperitoneal cocaine have an enhanced motor stimulant response to intra-A10 injection of enkephalin analogue.
Strategic and tactical planning of a closed-loop supply chain network under uncertainty

While the strategic planning of a supply chain, which is typically a long range planning, deals with the design aspect of the supply chain (what products should be processed/produced in what facilities etc.), tactical planning is typically a medium-range planning that involves the optimization of flow of goods and services across the supply chain. In this paper, we present a multi-criteria optimization model for the strategic and tactical planning of a closed-loop supply chain under uncertainty, where the aspiration levels for various goals are more likely to be in the "approximately more/less than" and/or "more/less is better" form. We use fuzzy goal programming technique to solve the problem. When solved, the model identifies simultaneously the most economical used-product to re-process in the supply chain, the efficient production facilities and the right mix and quantity of goods to be transported across the supply chain. A numerical example is considered to illustrate the methodology.
Of Fair Markets and Distributive Justice

The authors argue that a free market paradigm facilitates wealth creation but does little to distribute that wealth in a just manner. In order to achieve the social goal of distributive justice, the concept of a fair market is introduced and explored. The authors then examine three drivers that can help improve the lives of all people, especially the poor: civil society, its institutions, and business. After exploring the roles these drivers might play in developing fair markets, we describe three enablers that serve as catalysts for change: the effects of globalization, the impact of technology, and the emergence of entrepreneurial activity. We conclude by making recommendations for establishing fair markets and provide exemplars of two firms that embody the arguments made in the article.
Medullary carcinoma of the thyroid: an update

Medullary carcinoma of the thyroid (MTC) represents 5-10% of differentiated thyroid cancers. It derives from the thyroid C-cells which produce calcitonin and are of neuroendocrine origin. It is a rather rare tumour and is accompanied by considerable mortality as it has frequently already metastasised at diagnosis and is not sensitive to either radiation or chemotherapy. Recently it has been shown that MTC is not infrequent in multinodular thyroid disease and thus universal calcitonin screening has been suggested in the diagnostic workup of thyroid nodules. The prognosis of the disease has recently improved as many of the newly diagnosed cases are now small, non-invasive tumours, that probably were previously missed. MTC is an interesting tumour as it occurs in a familial form in >25% of the cases, as part of the multiple endocrine neoplasia 2 syndromes (MEN2). When familial MTC may occur in combination with pheochromocytomas and, more rarely, with primary hyperparathyroidism. Recent advances in MTC management include preclinical diagnosis using molecular techniques in the case of familial disease and prophylactic thyroidectomy in asymptomatic gene carriers. The gene responsible for transmission of the MEN2 is the ret proto-oncogene, which is a membrane receptor tyrosine kinase; its physiological role is the transmission of neural signals during development. Most of the mutations which are found in MEN2 syndromes are clustered in the cysteine rich extracellular domain of the protein and either cause dimerisation or ligand-independent activation. Novel previously unknown ret mutations across many regions of the gene are currently being recognized. Mutation analysis should be performed in all cases of MTC because these sometimes represent unrecognized familial disease. When a mutation is identified, family members are screened and carriers are offered prophylactic thyroidectomy at a young age. The type of mutation is classified into more or less aggressive and it is important for the penetrance of the disease. The majority of experts suggest prophylactic surgery at 5-10 years, especially when the specific mutation associates with risk for earlier MTC development and more aggressive disease. Several recent publications have examined the success/cure rate of prophylactic treatment. One important development in the field of MTC concerns the use of newer antineoplastic agents, including agents targeting the molecular pathways involved in its pathogenesis. Novel multi targeted tyrosine kinase inhibitors are being tested in advanced disease in the context of clinical trials. Recent publications indicate that a substantial proportion of patients with advanced disease will stabilize with the use of these promising agents. Patients with familial disease appear to respond better to therapy with tyrosine kinase inhibitors. Combination therapies are also being tested.
Carbon use efficiency, and net primary productivity of terrestrial vegetation

Abstract The carbon use efficiency (CUE), defined as the ratio of net carbon gain to gross carbon assimilation during a period, is a highly significant determinant of primary production of terrestrial plant communities. Available data for CUE is summarized. Then, a model for gross assimilation has been run using satellite and ancillary data to calculate annual net carbon gain or net primary productivity for the global land surface during four year period (1987–1990). The results are compared with other estimates. Interannual variability of 30–50% is found in some of the latitude bands.
Mechanistic studies on reaction of [ReH4(η2-H2)(Cyttp)]+ with ketones to give the hydrido-oxo complex [ReH2(O)(Cyttp)]+ (Cyttp = PhP(CH2CH2CH2PCy2)2)

Abstract Mechanistic studies were conducted on reaction of [ReH 4 (η 2 -H 2 )(Cyttp)]OTf ( 1 (OTf); Cyttp = PhP(CH 2 CH 2 CH 2 PCy 2 ) 2 , OTf = O 3 SCF 3 ) with ketones, both neat and in solution. Treatment of 1 (OTf) with excess acetone at 60–65 °C affords [ReH 2 (O)(Cyttp)]OTf ( 2 (OTf)) in high yield, nearly 1 equiv. of H 2 , 2 equiv. of 2-propanol, 1 equiv. of each of 4-hydroxy-4-methyl-2-pentanone ( B ) and 4-methylpent-3-en-2-one ( C ), and smaller amounts of other organic products derived by condensation or related reactions of acetone. The presence of C , apparently arising by dehydration of B , points to the formation of 1 equiv. of H 2 O in the reaction system. Use of acetone-d 6 in conjunction with 1 (OTf) gives 2 (OTf) containing no deuterium, as well as 1 equiv. of each of (CD 3 ) 2 CHOH/OD and (CD 3 ) 2 CDOD/OH. Reactions of 1 (OTf) with cyclohexanone, including cyclohexanone-2,2,6,6-d 4 , under comparable conditions, give analogous results. The ketones cyclopentanone, 2-butanone, and 3-pentanone also convert 1 (OTf) to 2 (OTf) upon heating, as does isobutyraldehyde, but only in the presence of the stabilizer BHT. In contrast, the more robust ketones 2,4-dimethyl-3-pentanone, 2,6-dimethylcyclohexanone, and 2-adamantanone, which do not undergo condensation, failed to effect this transformation. Other organooxygen compounds, i.e., methanol, cyclohexanol, 1,2-butene oxide, cyclohexene oxide, DMSO, and Me 3 NO, also are ineffective. A mechanism is proposed which begins with loss of H 2 by 2 to give a 16-electron “[ReH 4 (Cyttp)] + ” which, depending on the experimental conditions, binds a solvent or ligand molecule. A [ReH 4 (R 2 C O)(Cyttp)] + intermediate generated in this manner reacts spontaneously by elimination of R 2 CHOH (containing methine hydrogen even when deuteriated ketone is used), which results from transfer of two hydride ligands to coordinated ketone. Continued reaction leads to the formation of 2 and another molecule of R 2 CHOH (containing methine deuterium when deuteriated ketone is employed), with the added hydrogens coming from H 2 O, which derives from solvent/reactant ketone.
INCREASED CORNEAL THICKNESS IN PATIENTS WITH OCULAR HYPERTENSION

Background Central corneal thickness greater than 0.520 mm causes true intraocular pressure to be overestimated when the technique of applanation tonometry is used to measure intraocular pressure. Objective To compare the corneal thickness measurements of patients enrolled in a study of ocular hypertension with those of age-matched control subjects with normal intraocular pressure. Methods Central corneal pachymetry using an optical pachymeter was performed on each study subject (n = 55) at baseline and in an independent sample of control subjects. A 2 sample, 2-tailedttest was used to compare the 2 populations. Results The patients with ocular hypertension had significantly higher mean corneal thickness measurements (mean ± SD, 0.594 ± 0.037 mm) than the control group (0.563 ± 0.027 mm) (P Conclusion Corneal thickness may be a confounding factor in the measurement of intraocular pressure, and this may modify the risk for progression to glaucoma in patients with ocular hypertension.
On Hurricane Outflow Structure

Abstract Flow fields from the model of Wu and Emanuel are presented. It is demonstrated that the interaction of background shear with a uniform source of low potential vorticity air at the storm top can produce many of the observed characteristics of hurricane outflow, including outflow jets. Our model is compared to other extant models of hurricane outflow.
The Degenerate Wino-like Chargino-Neutralino Scenario at Hadron Colliders

For some choices of soft SUSY-breaking parameters, the LSP is a stable neutralino , the NLSP is a chargino almost degenerate in mass with the LSP , and all other sparticles are relatively heavy. We discuss the potential of hadron colliders, particularly the LHC, for studying such models.
Absence of localized-spin magnetism in the narrow-gap semiconductor FeSb2

We report on the inelastic neutron scattering measurements aimed at investigating the origin of temperature-induced paramagnetism in narrow-gap semiconductor FeSb${}_{2}$. We find that inelastic response for energies up to 60 meV and at temperatures $\ensuremath{\approx}$$4.2$, $\ensuremath{\approx}$$300$, and $\ensuremath{\approx}$$550$ K is essentially consistent with the scattering by lattice phonon excitations. We observe no evidence for a well-defined magnetic peak corresponding to the excitation from the nonmagnetic $S=0$ singlet ground state to a state of magnetic multiplet in the localized-spin picture. Our data establish the quantitative limit of ${S}_{\text{eff}}^{2}\ensuremath{\lesssim}0.25$ on the fluctuating local spin. However, a broad magnetic scattering continuum in the 15 to 35 meV energy range is not ruled out by our data. Our findings make description in terms of the localized Fe spins unlikely and suggest that paramagnetic susceptibility of itinerant electrons is at the origin of the temperature-induced magnetism in FeSb${}_{2}$.
An implicit adaptation algorithm for a linear model reference control system

This paper presents a stable implicit adaptation algorithm for model reference control. The constraints for stability are found using Lyapunov's second method and do not depend on perfect model following between the system and the reference model. Methods are proposed for satisfying these constraints without estimating the parameters on which the constraints depend.
Tobacco lobby threatens to derail global antismoking treaty.

World Health Organization officials say that a global anti-tobacco pact that becomes law on 27 February still has a long way to go before its tough antismoking measures are adopted in many countries. WHO's 192 member states adopted the Framework Convention on Tobacco Control in 2003. Since then, 168 countries have signed it; 55 of these have ratified it, but only a few have passed its terms into law. The convention includes a comprehensive ban on tobacco advertising, marketing, and sponsorship; tough standards for health warnings on cigarette …
Comparison of vibrotactile threshold and suprathreshold responses in men and women

Vibrotactile tb:resholds were measured on the thenar eminence of 12 men and 12 women at 10 sinusoidal frequencies. No significant differences between the two groups were observed. Magnitude estimation and production procedures carried out with 6 men and 6 women from the same groups showed that women perceive suprathreshold vibration stimuli as more intense than do men, although women and men do not differ in their estimation of the length of lines.
The developing neostriatum of the rabbit: Correlation of fluorescence histochemistry, electron microscopy, endogenous dopamine levels, and [3H]dopamine uptake

Abstract A correlation has been made between the sequential variation of fluorescent profiles during early fetal development and the maturation of growth cones into more differentiated axons with synapses ‘en passage’. The initial ingrowth of fluorescent axons enters the ventromedial putamen, probably in the angle formed by the external capsule, anterior commissure, and internal capsule. Later in fetal life, a second ingrowth of axons running adjacent to the internal capsule enters both the caudate nucleus and putamen. Circumscribed islands of fluorescence which are visible in late fetal and early postnatal stages, may indicate an anatomical and functional organization not previously recognized. The attainment of maximum endogenous dopamine levels in the rabbit lags behind the maturation of the uptake system and the development of the mature number of vesicle-filled processes and synaptic profiles. The maturation of the uptake process and the development of adult numbers of vesicle-filled axonal profiles, on the other hand, appear to correlate quantitatively with one another. The latter observation and the linear character of the fluorescent profiles tend to support the notion that axons having synapses ‘en passage’ and vesicles along their length may correspond to the dopamine-containing axons.
A unity gain cathode follower

Abstract A very high impedance (10 12 ω at D.C.) amplifier has been designed and constructed for use with ultramicroelectrodes in neurophysiological investigations. The amplifier was designed to have exactly unity gain and to neutralize the interelectrode capacity of the input tube without the use of an external feedback capacitor to neutralize the grid to ground capacity of the microelectrode. Response is flat from D.C. to 700 kc., and a voltage step function applied to the input through 10 MΩ produces an output response with a time constant less than 3μ see. Grid current of the low noise input tube, Z729, is adjustable through zero.
The Effect of Teachers' Language on Students' Conceptions of the Nature of Science.

Conveying an adequate conception of the nature of science to students is implicit in the border context of what has come to be known as scientific literacy. However, it has previously been demonstrated that possession of valid conceptions of the nature of science does not necessarily result in the performance of those teaching behaviors that are related to improved student conceptions. The present study examines the possibility that the language teachers use to communicate science content may provide the context (Realist or Instrumentalist orientations) in which students come to formulate a world view of science. Eighteen high school biology teachers and one randomly selected class from each of their sections (n = 409 students) were administered pre- and posttests at the beginning and end of the fall term using the Nature of Scientific Knowledge Scale (NSKS). Composite scores of the student changes on the Testable, Developmental, and Creative subscales were used to compare those six classes that exhibited the greatest change with those six classes that had the least change on the NSKS. Intensive qualitative observations of each teacher were also conducted over the fall semester, resulting in complete transcripts of teacher-student interactions. Qualitative comparisons of classes with respect to six variables related to Realist and Instrumentalist conceptions of the nature of science were conducted. TEACHERS' ordinary language in the presentation of subject matter was found to have significant impact on students' conceptions of the nature of science. These variables represented different contexts (Realist-Instrumental) teachers used to express themselves, scientific information, and concepts. Determining the extent to which TEACHERS' language has an impact on changes in students' conception of the nature of science has direct bearing on all preservice and inservice science teacher education programs.
Visual aids to create a knowledge base with reusable objects across disciplines

This paper describes the design of reusable interactive visual aids to teach abstract concepts in Set Theory and Logic.
Liquidity and Liquidation: Evidence from Real Estate Investment Trusts

This studdy provides evidence that highly leveraged owner-managed properties liquidated assets during the commercial real estate decline of the late 1980s, and that this provided buying opportunities for better capitalized buyers. The analysis documents significant financial distress costs for highly leveraged firms during an industry-wide downturn and shows that these costs are particularly large for ownermanaged firms. THIS PAPER EXMINES THE EFFECTS of the large decline in commercial real estate values that occurred in the late 1980s and early 1990s because of (i) declines in occupancy rates in commercial properties as a result of overbuilding during the 1980s, and (ii) credit problems that limited the financing available for borrowers (see Fergus and Goodman (1994) and Peek and Rosengren (1994)). The analysis compares the effects of the decline in commercial real estate values on highly leveraged owner-managed properties and on less leveraged properties held by real estate management companies with access to public equity markets. The data on owner-managed properties are from mortgage Real Estate Investment Trusts (REITs), publicly traded entities that make commercial real estate loans largely to owner-managed property managers or developers, and the loan-to-value ratio on these loans is typically 80 percent or more. In contrast, equity REITs hold equity positions with much less financial leverage and the properties are managed by corporate property managers. This paper provides a systematic analysis of the mortgage and equity REITs during the real estate downturn and yields three important findings. First, the book value of mortgage loans held by mortgage REITs declines significantly from the end of 1988 to the end of 1991, while the book value of real estate equity positions held by equity REITs increases. During this period, mortgage REITs are net sellers of highly leveraged assets and equity REITs are net purchasers. Second, in spite of the indications that the market for commercial real estate is very depressed, mortgage REITs seldom reorga
Characterization and Theoretical Comparison of Branch-and-Bound Algorithms for Permutation Problems

Branch-and-bound implicit enumeration algorithms for permutation problems (discrete optimization problems where the set of feasible solutions is the permutation group Sn) are characterized in terms of a sextuple (Bp S,E,D,L,U), where (1) Bp is the branching rule for permutation problems, (2) S is the next node selection rule, (3) E is the set of node elimination rules, (4) D is the node dominance function, (5) L is the node lower-bound cost function, and (6) U is an upper-bound solution cost. A general algorithm based on this characterization is presented and the dependence of the computational requirements on the choice of algorithm parameters, S, E, D, L, and U is investigated theoretically. The results verify some intuitive notions but disprove others.
Solving Galerkin approximation to nonlinear two-point boundary value problems bya globally convergent homotopy method

The Chow-Yorke algorithm, i.e., a homotopy method that has been proved globally convergent j problems, certain classes of zero finding and nonlinear programming problems, and two-point, boundary based on shooting, finite differences, and spline collocation. The method is numerically stable and has been applied to a wide range of practical engineering problems. Here the Chow-Yorke algorithm is proved globally c Galerkin approximations to nonlinear two-point boundary value problems. Several numerical implement are briefly described, and computational results are presented for a fairly difficult, magnet-hydrodynamic problem. Key words. homotopy method, Chow-Yorke algorithm, globally convergent,, two-point boundary value method, finite element method, nonlinear equations
Rapid determination of thymidylate synthase activity and its inhibition in intact L1210 leukemia cells in vitro

Abstract A rapid and convinient tritium release assay for measuring thymidylate (dTMP) synthase activity and its inhibition within intact mammalian cells is described in detail. Short-term incubation of murine leukemia L1210 cells with an appropriately labeled substrate precursor, either deoxyuridine ([5- 3 H]dUrd) or deoxycytidine ([5- 3 H]dCyd), allowed for: (1) uptake and intracellular conversion to the substrate deoxyuridylate ([5- 3 H]dUMP); and (2) the obligatory displacement of tritium from [5- 3 H]-dUMP during the dTMP synthase catalyzed reaction. Tritium released into the aqueous environment was quantitated after a quick one-step separation of tritated H 2 O from other radiolabeled materials and cell debris. The amount of tritium released was evaluated as a function of a number of variables, including the concentration of labeled substrate precursors, cell number, and incubation time. Tritium from [5- 3 H]dCyd was released significantly faster than from [5- 3 H]dUrd under a variety of conditions. Both 5-fluorodeoxyuridine (1 μM) and methotrexate (10 μM), which effectively block intracellular dTMP synthesis, completely inhibited the release of tritium from either [5- 3 H]dCyd or [5- 3 H]dUrd demonstrating that the release of tritium is mediated exclusively by the dTMP synthase catalyzed reaction. In addition, there was a good correlation between tritium release, cellular uptake, and incorporation of [2- 14 C]dUrd into DNA. The inhibitory effects of antifolates such as methotrexate were independent of the type of labeled precursor used. In contrast, preferential interference with the release of tritium from [5- 3 H]-dCyd by dCyd derivatives and from [5- 3 H]dUrd by dUrd derivatives was observed, suggesting that competition for uptake and/or phosphorylation may contribute to the overall effects of certain nucleoside analogues on cellular dTMP synthase activity measured using the tritium release assay.
Pre-pregnancy body mass index change between pregnancies and preterm birth in the following pregnancy

Maternal pre-pregnancy body mass index (BMI) may affect the risk of preterm birth. However, it is unclear how changes in BMI between pregnancies modify the risk of preterm birth in the following pregnancy. We studied this effect in the Collaborative Perinatal Project, when obesity was uncommon and the prevalence of induction of labour was low. This analysis included 1892 primiparae whose first enrolled (index) pregnancy was a singleton livebirth and the second enrolled (outcome) pregnancy was a consecutive singleton pregnancy (both pregnancies within 20-51 weeks of gestation). We used the Cox regression model to calculate the hazard ratio (HR) of preterm birth at the outcome pregnancy as a function of reduced BMI ( 75(th) percentile), compared with stable BMI (25(th)-75(th) percentile), adjusted for pre-pregnancy BMI at the index pregnancy and other covariates. Body mass index reduction was associated with a non-significant increased risk of preterm birth, adjusted HR 1.17 [95% confidence interval 0.90, 1.53]; BMI increase had effects close to null (adjusted HR 1.08 [0.83, 1.41]). In the model with linear BMI change, each 1 kg/m(2) increase was associated with an HR of 0.96 [0.89, 1.03]. The estimates associated with a BMI reduction were higher in women whose index pregnancy ended preterm (HR 1.49 [0.90, 2.44]) and in those with BMI < 25 kg/m(2) at the index pregnancy (HR 1.30 [0.98, 1.71]). This study involved mainly low-to-normal weight women with spontaneous deliveries, and might suffer from type II error owing to small sample size. The effect of BMI change in overweight and obese women needs to be studied using contemporary data.
CONTRIBUTION OF COGNITIVE INTERFERENCE TO DECREMENTS IN WALKING PERFORMANCE IN HEMODIALYSIS PATIENTS

Patients with advanced CKD have impaired walking function that predisposes them to falls and disability. Deficits in walking function are traditionally ascribed to declines in physical function. However, walking impairment in certain clinical populations may also result from a phenomenon known as cognitive-motor interference. This is characterized by reductions in motor task performance (e.g., walking speed) when simultaneously performing a cognitive task, and is termed a dual task cost (DTC). The purpose of this study was to compare the contribution of cognitive interference to decrements in walking performance in hemodialysis patients and healthy controls. 14 hemodialysis patients (10M,4F, age=48.5+/-11.8) and 14 age-matched healthy controls (9M, 5F, age=48.5+/- 10.1) participated. Each completed a walking task in a control and dual task condition. The walking task involved walking at a comfortable pace 4 times across a 26’GAITRite TM mat. The first 2 trials were completed with no cognitive task and the last 2 trials with a simultaneous task that consisted of generating a modified word list. Walking performance was quantified with normalized gait speed, step length, base of support, and step time. DTC was determined for each variable as the % difference in performance between the single task and dual task. Major metrics of walking function under standard conditions were impaired by 20-40% in hemodialysis patients vs controls (p These data indicate that walking impairments in hemodialysis patients are not due exclusively to declines in physical function, but that cognitive-motor interference also plays a significant role. This has significant clinical importance, as therapies designed to improve walking performance and physical function, such as nutritional and exercise interventions, may need to be augmented with cognitive training in order to have maximum benefits.
The bubble stripping method for determining dissolved hydrogen (H2) in well water

The bubble stripping method was developed for use at field sites to measure the concentration of dissolved hydrogen (H2) in ground water. This information is useful in assessing the viability of employing monitored natural attenuation (MNA) as a strategy to influence the restoration of sites contaminated with chlorinated solvents. In laboratory studies, a reservoir containing water was employed to simulate a well. The system was constructed so that the concentration of dissolved H2 could be maintained at a constant level. The method was applied by pumping water from the reservoir into a sample cell, and then injecting 20 ml of nitrogen into the cell to produce a headspace (the “bubble”). Stripping was accomplished by pumping water through the cell, which produced agitation between the aqueous phase and the headspace. Pumping was continued for a length of time sufficient for dissolved H2 to partition between the two phases. Analysis of H2 in the headspace by gas chromatography enabled the concentration of dissolved H2 in solution to be calculated with the use of Henry's law. Two sample cell designs were compared in this study, the Microseeps Cell and the Chapelle Cell. Kinetics of equilibration studies were conducted with each cell, employing solution flow rates of 200, 300, and 400 ml/min, at 4 and 21 °C. The Microseeps Cell compared favorably with the Chapelle Cell with regards to kinetics of equilibration, with the added benefit of costing significantly less. © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 283–296, 2000
Building Highly Dependable Wireless Web Services

In this paper, the authors introduce Web services technology and its applications to mobile business transactions. This paper shows that the Web services technology is a powerful tool to build next-generation e-Commerce applications for wireless mobile devices following the service-oriented architecture. Such an approach would bring significant benefits to organizations involved with e-Commerce. The authors further discuss the importance of ensuring high dependability of Web services and provide a literature review of state-of-the-art techniques that are critical to the implementation of practical and dependable wireless Web services. Finally, research on the design, implementation, and performance evaluation of a fault tolerance framework for wireless Web services are described.
Heart-muscle fiber reconstruction from diffusion tensor MRI

In this paper we use advanced tensor visualization techniques to study 3D diffusion tensor MRI data of a heart. We use scalar and tensor glyph visualization methods to investigate the data and apply a moving least squares (MLS) fiber tracing method to recover and visualize the helical structure and the orientation of the heart muscle fibers.
Mixed-Model Reanalysis of Primate Data Suggests Tissue and Species Biases in Oligonucleotide-Based Gene Expression Profiles

An emerging issue in evolutionary genetics is whether it is possible to use gene expression profiling to identify genes that are associated with morphological, physiological, or behavioral divergence between species and whether these genes have undergone positive selection. Some of these questions were addressed in a recent study (Enard et al. 2002) of the difference in gene expression among human, chimp, and orangutan, which suggested an accelerated rate of divergence in gene expression in the human brain relative to liver. Reanalysis of the Affymetrix data set using analysis of variance methods to quantify the contributions of individuals and species to variation in expression of 12,600 genes indicates that as much as one-quarter of the genome shows divergent expression between primate species at the 5% level. The magnitude of fold change ranges from 1.2-fold up to 8-fold. Similar conclusions apply to reanalysis of Enard et al. 2002 parallel murine data set. However, biases inherent to short oligonucleotide microarray technology may account for some of the tissue and species effects. At high significance levels, more differences were observed in the liver than in the brain in each of the pairwise species comparisons, so it is not clear that expression divergence is accelerated in the human brain. Further, there is an apparent bias toward upregulation of gene expression in the brain in both primates and mice, whereas genes are equally likely to be up- or downregulated in the liver when these species diverge. A small subset of genes that are candidates for adaptive divergence may be identified on the basis of a high ratio of interspecific to intraspecific divergence.
Ignition of Ethylene–Air and Methane–Air Flows by Low-Temperature Repetitively Pulsed Nanosecond Discharge Plasma

This paper presents results of low-temperature plasma-assisted combustion experiments in premixed ethylene-air and methane-air flows. The plasma was generated by high-voltage, nanosecond pulse duration, high repetition rate pulses. The high reduced electric field during the pulse allows efficient electronic excitation and molecular dissociation, thereby generating a pool of chemically active radical species. The low duty cycle of the repetitively pulsed discharge improves the discharge stability and helps sustain diffuse, uniform, and volume filling nonequilibrium plasma. Plasma temperature was inferred from nitrogen second positive band system emission spectra and calibrated using thermocouple measurements in preheated flows (without plasma). The experiments showed that adding fuel to the air flow considerably increases the flow temperature in the plasma, up to DeltaT = 250degC-350degC. On the other hand, adding fuel to nitrogen flow at the same flow and discharge conditions resulted in a much less pronounced plasma temperature rise, only by about DeltaT = 50degC. This shows that temperature rise in the air-fuel plasma is due to plasma chemical fuel oxidation reactions initiated by the radicals generated in the plasma. In a wide range of conditions, generating the plasma in air-fuel flows resulted in flow ignition, flameholding, and steady combustion downstream of the discharge. Plasma-assisted ignition occurred at low air plasma temperatures, 100degC-200 degC, and low discharge powers, ~100 W (~1% of heat of reaction). At these conditions, the reacted fuel fraction is up to 85%-95%. The present results suggest that the flow temperature rise caused by plasma chemical fuel oxidation results in flow ignition downstream of the plasma.
Tensor Voting Accelerated by Graphics Processing Units (GPU)

This paper presents a new GPU-based tensor voting implementation which achieves significant performance improvement over the conventional CPU-based implementation. Although the tensor voting framework has been used for many vision problems, it is computationally very intensive when the number of input tokens is very large. However, the fact that each token independently collects votes allows us to take advantage of the parallel structure of GPUs. Also, the good computing power of modern GPUs contributes to the performance improvement as well. Our experiments show that the processing time of GPU-based implementation can be, for example, about 30 times faster than the CPU-based implementation at the voting scale factor sigma = 15 in 5D
High-resolution visualization of oxygen distribution in the liver in vivo

Microcirculatory failure after stress events results in mismatch in oxygen supply and demand. Determination of tissue oxygen distribution in vivo may help elucidate mechanisms of injury, but presen...
Infection of Hydra by Microsporidia

A microsporidian infection in a laboratory clone of Hydra littoralis has been observed, and the parasite has been tentatively identified as a species of Plistophora. Infected hydra continue to bud and regenerate normally and show no significant physiological or morphological changes. Sexual crossing of infected and non-infected animals shows that the infection is transmitted by the ovum but not by the sperm. Continuous exposure of infected hydra to Fumidil B in solution resulted in the disappearance of all Plistophora spores after a five week period of treatment, and the clones of the treated animals have remained parasite-free for more than a year.
Perpetuating U.S. Preeminence: The 1990 Deals to "Bribe the Soviets Out" and Move NATO In

Washington and Bonn pursued a shared strategy of perpetuating U.S. preeminence in European security after the end of the Cold War. As multilingual evidence shows, they did so primarily by shielding the North Atlantic Treaty Organization (NATO) from potential competitors during an era of dramatic change in Europe. In particular, the United States and West Germany made skillful use in 1990 of Soviet leader Mikhail Gorbachev's political weakness and his willingness to prioritize his country's financial woes over security concerns. Washington and Bonn decided “to bribe the Soviets out,” as then Deputy National Security Adviser Robert Gates phrased it, and to move NATO eastward. The goal was to establish NATO as the main post–Cold War security institution before alternative structures could arise and potentially diminish U.S. influence. Admirers of a muscular U.S. foreign policy and of NATO will view this strategy as sound; critics will note that it alienated Russia and made NATO's later expansion possible. Ei...
Trying not to get burned: understanding homeowners' wildfire risk-mitigation behaviors.

Three causes have been identified for the spiraling cost of wildfire suppression in the United States: climate change, fuel accumulation from past wildfire suppression, and development in fire-prone areas. Because little is likely to be performed to halt the effects of climate on wildfire risk, and because fuel-management budgets cannot keep pace with fuel accumulation let alone reverse it, changing the behaviors of existing and potential homeowners in fire-prone areas is the most promising approach to decreasing the cost of suppressing wildfires in the wildland–urban interface and increasing the odds of homes surviving wildfire events. Wildfire education efforts encourage homeowners to manage their property to decrease wildfire risk. Such programs may be more effective with a better understanding of the factors related to homeowners’ decisions to undertake wildfire risk–reduction actions. In this study, we measured whether homeowners had implemented 12 wildfire risk–mitigation measures in 2 Colorado Front Range counties. We found that wildfire information received from local volunteer fire departments and county wildfire specialists, as well as talking with neighbors about wildfire, were positively associated with higher levels of mitigation. Firsthand experience in the form of preparing for or undertaking an evacuation was also associated with a higher level of mitigation. Finally, homeowners who perceived higher levels of wildfire risk on their property had undertaken higher levels of wildfire-risk mitigation on their property.
Perianaesthetic risks and outcomes of abdominal surgery for metastatic carcinoid tumours

Patients with metastatic carcinoid tumours often undergo surgical procedures to reduce the tumour burden and associated debilitating symptoms. These procedures and anaesthesia can precipitate a life-threatening carcinoid crisis. To assess perioperative outcomes, we studied retrospectively the medical records of adult patients from 1983 to 1996 who underwent abdominal surgery for metastatic carcinoid tumours. Preoperative risk factors, intraoperative complications and complications occurring in the 30 days after surgery were recorded. Perioperative complications or death occurred in 15 of 119 patients (12.6%, exact confidence interval 7.2-19.9). None of the 45 patients who received octreotide intraoperatively experienced intraoperative complications compared with eight of the 73 patients (11.0%) who did not receive octreotide (P=0.023). The presence of carcinoid heart disease and high urinary output of 5-hydroxyindoleacetic acid preoperatively were statistically significant risk factors for perioperative complications.
Options for treatment of spontaneous mesenteric artery dissection

Objective Mesenteric artery dissection was once thought to be rare but has been identified more frequently with increasing use of computerized tomographic angiographic imaging. Multiple reports advocate a wide range of treatment including medical therapy, endovascular, and surgical intervention, with no clear guidelines for the application of each treatment. Methods A systematic review of the literature was analyzed and used to create a treatment algorithm that was applied to nine patients in our institution. Results Although medical therapy is adequate for most patients with mesenteric artery dissection, 14% failed medical therapy, sometimes with severe consequences. Asymptomatic status on presentation predicted successful medical therapy for superior mesenteric artery dissection ( P = .0037). Conclusions Intensive surveillance is indicated during medical therapy, and invasive intervention may be necessary.
Evaluation of the patterns of potentially toxic exposures in Mississippi following Hurricane Katrina

Objective. To describe the changes in the frequency of selected toxic exposures reported to the state poison control center following Hurricane Katrina. Methods. The numbers of selected exposures reported to the Mississippi Poison Control Center at 0–2 weeks, 3–4 weeks, and 5–12 weeks following Hurricane Katrina were compared to those for the same time periods in the previous 3 years. Absolute numbers of exposures and odds ratios with confidence intervals were used for comparison. Results. In the first 2 weeks following Hurricane Katrina, there were 44 reported gasoline exposures compared to 7 expected, 8 lamp oil exposures compared to 1 expected, and seven carbon monoxide exposures compared to 1 expected. Only gasoline exposures remained elevated in the second 2 weeks period following the hurricane. Lamp oil exposures were elevated during the 5–12 week recovery period. There was no increase in the frequency of exposures to household cleaning agents, food poisoning, pediatric exposures, drug-related suici...
Avoiding the Short- and Long-Term Complications of Juvenile Diabetes

Type I diabetes (insulin-dependent diabetes mellitus, juvenile diabetes) is by far the most frequent type of diabetes to occur in children and adolescents. The prevalence is approximately 2/1,000 among those less than the age of 20 years in the United States. A second type of diabetes, maturity-onset diabetes in youth, is rare in comparison, is probably inherited as an autosomal dominant trait, and is usually found in overweight teenagers. Type I diabetes results from reduced or absent production of insulin. In patients with maturity-on-set diabetes in youth, insulin production is usually normal or reduced, and C-peptide levels are general low.1 ETIOLOGY The etiology of type I diabetes is not completely understood but probably involves an interaction between genetic, immunologic, and (viral) infectious factors. Only the order of relative importance assigned to the three has shown change in the past several decades; immunologic factors are considered to have increased from the number three to the number two position in recent years. Genetic Factors The human insulin gene is located on the short arm of chromosome 11. The immune response locus (HLA-D) is located on chromosome 6. The genetics of diabetes were previously described as "a geneticist9s nightmare." Earlier studies had shown that when type I diabetes developed in one member of a set of identical twins the other twin had a 50% chance of also having the disease.
Supply of gastropod larvae to hydrothermal vents reflects transport from local larval sources

Variation in larval supply to disjunct marine populations can provide insight into larval transport and delivery mechanisms, especially when compared with observations of physical transport. Daily variability in larval supply at two mussel-dominated hydrothermal vents, East Wall and Choo Choo, near 9u509N, East Pacific Rise, was quantified concurrently with hydrodynamic observations to investigate local dispersal processes. The magnitude and temporal variation in supply differed between the two vent sites despite their close proximity, 1.6 km. Larval supply was relatively high and uninterrupted at East Wall compared to low and episodic at Choo Choo. Observed variation in larval supply was compared to predictions based on advective transport from larval sources at neighboring vents. Variation in larval supply at Choo Choo correlated with along-axis southward currents, consistent with larval transport from a northern larval source. Larval supply to East Wall appeared to be independent of current velocities, suggesting that larvae came from multiple sources north of and south of and possibly including East Wall. Transport of larvae from discrete local sources can explain differences in larval supply to vent communities, even on spatial scales of kilometers.
Application of Many-Body Potentials to Noble Metal Alloys

A significant recent development in the field of interatomic potentials has been the introduction of many-body terms which model the effect of the local electronic density. Different schemes of this type1,2,3, although derived from different approaches, yield strikingly similar models in the case of pure metals. In numerous applications many-body potentials have given reasonable results, generally similar to those obtained using pair potentials, but these models also yield good results in simulating vacancies and surfaces; applications for which traditional pair potentials are inadequate.