cssi/SciSciGPT-SciSciNet huggingface dataset:
Energy balance in female distance runners

Metabolic efficiency was assessed in ovulatory eumenorrheic female distance runners and untrained control subjects of similar age, body weight, and fat-free mass (FFM). Energy intake (EI) was estimated from 3-d dietary records. Energy expenditure (EE) was determined during the same 3-d period from individual heart rate oxygen uptake (HR/VO2) curves during rest and exercise, 24-h HR records, and the thermic effect of meals. The runners and control subjects did not differ in resting metabolic rate statistically adjusted for FFM (kJ/min), the thermic effect of a test meal (kJ/3 h), the energy cost of submaximal physical activity, or EI. EE was higher (P = 0.01) in the runners. Reported EI was lower than EE in both the runners (P = 0.007) and control subjects, (P = 0.006), resulting in energy deficits of -4131 +/- 1185 kJ/d and -1652 +/- 456 kJ/d, respectively. These female runners did not exhibit an enhanced metabolic efficiency compared with the control subjects. It is possible that the energy deficit for both the runners and control subjects was due to both restricted eating and underreporting during the measurement period. Additional studies using longer measurement periods, more sophisticated technology (ie, doubly labeled water, more subjects, and subjects of varying menstrual and energy intake status) are needed to truly answer this question.
Practical aspects of a-posteriori estimation for reliable finite element analysis

Abstract In this paper we study the problem of a-posteriori estimation of the error in the derivatives, strains and stresses in finite element solutions of the elasticity problem. Given any small patch of elements, we split the error in the patch into two components: the local (or near-field) error which is the response of the elastic continuum in the patch when the domain is loaded only by the near-field residuals, i.e. the residuals of the finite element solution in the elements in the neighborhood of the patch (the patch and a few, e.g. one, surrounding mesh-layers), and the pollution (or far-field) error which is the response in the patch when the domain is loaded by the residuals of the finite element solution in the elements outside the neighborhood of the patch (the far-field residuals). The local error can be estimated by employing element error indicators, which are determined using local computations in the neighborhood of the patch (element residual problems, or local averagings), while the estimation of the pollution error requires a global extraction. This extraction can be based on the ability of the code to compute energy inner products of error indicator functions corresponding to the finite element solution and finite element approximations of a few auxiliary functions which are determined (with negligible cost when a direct solver is employed) by solving the global finite element equations for a few additional auxiliary loads.
THE CHARACTERIZATION OF STAPHYLOCOCCAL TOXINS : II. THE ISOLATION AND CHARACTERIZATION OF A HOMOGENEOUS STAPHYLOCOCCAL PROTEIN POSSESSING ALPHA HEMOLYTIC, DERMONECROTIC, LETHAL, AND LEUCOCIDAL ACTIVITIES.

The continuous flow paper electrophoretic methods used to isolate alpha hemolysin are presented. The purity of the alpha hemolysin preparation is demonstrated by double agar diffusion, immunoelectrophoretic, and ultracentrifugation techniques. Indirect evidence of purity is provided by the fact that rabbit immunized with purified alpha hemolysin produced detectable antibody only to alpha hemolysin. Direct support is given to the "unitarian theory" by the demonstration that purified alpha hemolysin also possessed dermonecrotic, lethal, and leucocidal activities. Further studies dependent on the availability of purified alpha hemolysin are outlined.
A catalytic switch and the conversion of streptokinase to a fibrin-targeted plasminogen activator.

Plasminogen (Pg) activators such as streptokinase (SK) save lives by generating plasmin to dissolve blood clots. Some believe that the unique ability of SK to activate Pg in the absence of fibrin limits its therapeutic utility. We have found that SK contains an unusual NH2-terminal “catalytic switch” that allows Pg activation through both fibrin-independent and fibrin-dependent mechanisms. Unlike SK, a mutant (rSKΔ59) fusion protein lacking the 59 NH2-terminal residues was no longer capable of fibrin-independent Pg activation (kcat/Km decreased by >600-fold). This activity was restored by coincubation with equimolar amounts of the NH2-terminal peptide rSK1–59. Deletion of the NH2 terminus made rSKΔ59 a Pg activator that requires fibrin, but not fibrinogen, for efficient catalytic function. The fibrin-dependence of the rSKΔ59 activator complex apparently resulted from selective catalytic processing of fibrin-bound Pg substrates in preference to other Pg forms. Consistent with these observations, the presence (rSK) or absence (rSKΔ59) of the SK NH2-terminal peptide markedly altered fibrinolysis of human clots suspended in plasma. Like native SK, rSK produced incomplete clot lysis and complete destruction of plasma fibrinogen; in contrast, rSKΔ59 produced total clot lysis and minimal fibrinogen degradation. These studies indicate that structural elements in the NH2 terminus are responsible for SK’s unique mechanism of fibrin-independent Pg activation. Because deletion of the NH2 terminus alters SK’s mechanism of action and targets Pg activation to fibrin, there is the potential to improve SK’s therapeutic efficacy.
Inhibitory effect of glucose on enzyme formation.

THE induced biosynthesis of many microbial enzymes is susceptible to the inhibitory effect of glucose1. The physiological significance of this phenomenon has been indicated by the study of an L-histidine-requiring mutant strain of Aerobacter aerogenes in which glucose inhibits the formation of histidase, thereby conserving the L-histidine for its specific role as growth factor2. Under conditions that permit a gratuitous, linear production of myoinositol dehydrogenase (another inducible enzyme in A. aerogenes) in the absence of the inducing agent, the glucose effect is still operative, indicating that glucose interferes with the production of enzyme rather than with .the process of induction3.
Quantum Electrodynamics in a Photon Sea

Thermal photons are present in every initial state, and nonthermal photons are present in many systems of interest. Furthermore, stimulated emission promotes the infrared divergence of quantum electrodynamics from logarithmic to an inverse power in a Planck distribution. I have calculated to order ${e}^{2}$ the background-photon corrections to the cross section for scattering a charged particle off an external Coulomb potential. I demonstrate the cancelation of infrared divergences, and derive a formal shift in the masses of charged particles. I interpret this shift, and discuss atomic spectra.
An algebraic approach to modeling

Abstract Problems constraining the successful application of large-scale models in a strategic planning environment are examined and indequate modeling languages and software are identified as the major source of difficulties. A General Algebraic Modeling System (GAMS), in use at the World Bank, is a possible solution. This system uses a language comprehensible by both people and computers and has automated most stages in the modeling process, thus making modeling quicker, cheaper, and less demanding of specialized skills, while reducing the likelihood of errors.
Erosion and surface structure development of metal–diamond particulate composites

Abstract Metal-matrix/diamond-abrasive composites are commonly employed in precision grinding of glasses and ceramics. Erosion, to replace worn diamond cutting points, is essential to proper tool functioning. However, the erosion behavior of these materials has not been well characterized or understood. In this study, the results of experiments on bronze-matrix, diamond-abrasive composite tool materials are described. The effects of systematic changes in the metal-matrix (“bond hardness” and measured mechanical properties) and diamond particles (size and concentration) on both the erosion rate and surface structure of the composites at different angles of attack were studied using a design of experiments approach. The composites exhibited ductile erosion behavior, characterized by an increase in erosion as the angle of attack was decreased. Changes in the metal-matrix produced statistically significant but relatively small effects. However, changes in diamond size and concentration strongly affected both the rate of erosion and the morphology of the eroded surface. Diamond particles smaller than the erodent had little protective effect. In contrast, diamond particles larger than the erodent protected the bond material immediately behind them, producing a comet tail structure and reducing erosion. The resultant surface morphologies closely resemble those produced during precision grinding of glasses and ceramics.
The Land Surface Climatology of the NCAR Land Surface Model Coupled to the NCAR Community Climate Model

Abstract The National Center for Atmospheric Research (NCAR) Land Surface Model (LSM, version 1.0) provides a comprehensive treatment of land surface processes for the NCAR Community Climate Model version 3 (CCM3). It replaces the prescribed surface wetness, prescribed snow cover, surface albedo, and surface flux parameterizations used in the CCM2. A 15-yr simulation of the coupled atmosphere (CCM3) and land (LSM1.0) models using observed sea surface temperatures for the period December 1978–September 1993 is used to document the model’s land surface climate. The model simulates many of the observed geographic and seasonal patterns of surface air temperature, precipitation, and soil water. In general, the transition seasons (spring, autumn) are better simulated than winter and summer. Annual precipitation and runoff are well simulated for some river basins and poorly simulated for others. In general, precipitation is better simulated than runoff. The inclusion of net land–atmosphere CO2 exchange is an imp...
Sustained high-dose nitroglycerin transcutaneous patch therapy in angina pectoris: evidence for attenuation of effect over time.

The safety and efficacy of using continuous high-dose transcutaneous nitroglycerin in doses up to 100 mg/24 hours in chronic stable angina was assessed in 20 patients using serial treadmill testing. Patients had first to show a response to sublingual nitroglycerin with a 20% improvement in exercise time. All patients were then titrated with 20 mg (40 cm2), 60 mg (120 cm2), 80 mg (160 cm2) or 100 mg (200 cm2) patches, until intolerable headache in association with a 10 mmHg reduction in blood pressure and a ten-beat increment in heart rate. Drug was then discontinued for 2 days and patients underwent three repeat stress tests to reestablish a consistent drug-free baseline. Patients were then randomized in double-blind fashion to receive either active patch (N = 11) in previous titration dose or placebo patch (N = 9), with treadmill tests performed at 0 (1 hour after previous patch removal), 4, and 24 hours after patch application at baseline and at weeks 1 and 2. Venous blood was obtained for measurement of plasma nitroglycerin levels. After the first 24 hours of active patch therapy, there was a significant reduction in systolic blood pressure (P = .05), a significant increase in heart rate (P = .01), and a minor increase in exercise tolerance (P = .06) compared to placebo. At weeks 1 and 2, there was an attenuation of drug effect in all of these parameters. Plasma nitroglycerin levels demonstrated consistently high plasma levels over each 24-hour dosing interval, on day 1, week 1, and week 2.(ABSTRACT TRUNCATED AT 250 WORDS)
1837 TRIIODOTHYRONINE PRODUCES PARADOXIC EFFECTS ON ANTIOXIDANT ENZYMES AND SURFACTANT IN FETAL RAT LUNG

1837 TRIIODOTHYRONINE PRODUCES PARADOXIC EFFECTS ON ANTIOXIDANT ENZYMES AND SURFACTANT IN FETAL RAT LUNG
Determiners of the Drift of the Eye during Monocular Fixation

The nature of the drift of the eye during monocular fixation was investigated by recording vertical and horizontal components of eye movements under a variety of viewing conditions. Extinguishing the fixation mark, or placing it at 30 cm instead of at optical infinity was found to increase the net absolute drift rate, as well as to alter the preferred direction of drift. This suggests, as do some previous findings, that the drift of the eye is at least indirectly influenced by visual factors. Changing the position of the viewing eye in the head produced systematic shifts in the preferred direction of drift. The relationship of these findings to various aspects of monocular and binocular fixation were discussed.
Laszlo, semantics, and systems definitions: A critique

This paper examines Laszlo's solution to the semantic problems of system definitions which hinder development of general systems theory. Laszlo's set theoretic structure is shown to add little to the reduction of semantic difficulties encountered in the development of an explication of the concept of a system. It is also suggested that the construal approach used by Marchal is more useful to produce a rigorous yet functional explication of the term system.
Oh no not again: recurring meningitis in a child: a case study

Abstract The purpose of this study is to document the sequela of events and changes in performance in a child whose hearing loss was secondary to meningitis, was implanted and contracted meningitis a second time. The results indicate that there was a significant change in M levels. More importantly, there was a significant change in speech perception performance after one month. However, after repeated MAPings and 6 months, performance did start to return to initial implant levels.
Pore-grain boundary interactions during sintering of pure nickel under variable pressure

It has been demonstrated that applied pressure and the resulting entrapped gas can significantly alter the microstructural evolution during the sintering of pure nickel compacts. High internal gas pressure can stabilize pore size, retarding pore coalescence, coarsening, sintering, and grain growth. In contrast, in normally sintered and hot-pressed bodies, small pores may be dragged with the boundaries and coalesce and coarsen to produce large, widely-spaced, and relatively immobile pores which then experience break-away
Lipopolysaccharide effects on sensitive and resistant variant Chinese hamster ovary cell lines.

Chinese hamster ovary (CHO . K1 . PRO) cell growth was inhibited by addition of a gram-negative bacterial lipopolysaccharide (LPS) to the cell culture medium. Growth inhibition began after three or four days of incubation, was dose-dependent up to a maximum at an LPS concentration of 500 microgram/ml and was accompanied by cell shape changes and enhanced cytoplasmic vacuolization. Formation of bizarre CHO . K1 . PRO cell shapes and vacuole formation were most pronounced after seven days of incubation with LPS and could be observed by light and electron microscopy. An LPS-resistant cell population was obtained by intermittent in vitro exposure to high levels of LPS; these variant cells or clones derived from them failed to display growth inhibition in the presence of LPS. A clone from the LPS-resistant variant population showed altered cell properties compared to the parental cell line which included changes in cell morphology, adhesion, and endocytosis. Parental cells was markedly density-inhibited, whereas the cariant clone exhibited considerable growth after confluency. The LPS-resistant variant cells showed a more elongated morphology than the parental line. No significant differences were observed between rates of detachment of parental and variant cells when sparse cultures of either line were removed from tissue culture dishes by ethylenediaminetetracetate (EDTA). However, at confluency approximately 100% of the variant cells versus 35% of the parental cells were removed by EDTA in one hour. Measurements of 125I-ferritin uptake by parental and variant cells showed approximately twenty-fold and twofold increases, respectively, in uptake induced by LPS when compared to untreated control cultures.
Phytosterol Ester Constituents Affect Micellar Cholesterol Solubility in Model Bile

Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.
Conservation laws and constitutive relations for density-gradient-dependent viscous fluids

Conservation laws and constitutive relations for a density-gradient-dependent viscous fluid as a multipolar continuum obeying an entropy inequality with generalized entropy flux and supply density are considered in this paper. A decomposition of the rate of work of dipolar stress, which reveals the contribution of various parts of this stress to the energy equation, is used to discuss the inconsistencies between the results obtained here and those obtained by Bluestein and Green [1] on the basis of the pioneering work of Green and Rivlin [8]. Furthermore, we discuss the connection between the model presented here and the materials of Korteweg type considered by Dunn and Serrin [6]. In particular, we relate the rate of work of dipolar stress and the interstitial working introduced by Dunn and Serrin [6].
Black Kids’ (B.K.) Stories: Ta(l)king (About) Race Outside of the Classroom

One approach to talking about race and racism in the classroom is to promote dialogic communication through open-ended dialogue and autoethnographic storytelling. In an effort to understand and con...
Miscibility and viscoelastic properties of acrylic polyhedral oligomeric silsesquioxane–poly(methyl methacrylate) blends

Abstract We investigate the miscibility of acrylic polyhedral oligomeric silsesquioxanes (POSS) [characteristic size d ≈2 nm] and poly(methyl methacrylate)(PMMA) in order to determine the effect of well-dispersed POSS nanoparticles on the thermomechanical properties of PMMA. Two different acrylic POSS species (unmodified and hydrogenated) were blended separately with PMMA at volume fractions up to ϕ =0.30. Both POSS species have a plasticizing effect on PMMA by lowering the glass transition temperature T g and decreasing the melt-state linear viscoelastic moduli measured in small amplitude oscillatory shear flow. The unmodified acrylic-POSS has better miscibility with PMMA than the hydrogenated form, approaching complete miscibility for loadings ϕ ϕ =0.05, the unmodified acrylic POSS induces a 4.9 °C decrease in the T g of PMMA, far less than the 17.4 °C decrease in the glass transition temperature observed in a blend of 5 vol% dioctyl phthalate (DOP) in PMMA; however, the decrease in the glass transition temperature per added plasticizer molecule is nearly the same in the unmodified acrylic-POSS–PMMA blend compared with the DOP–PMMA blend. Time-temperature superposition (TTS) was applied successfully to the storage and loss moduli data and the resulting shift factors were correlated with a significant increase in free volume of the blends. The fractional free volume f 0 =0.046 for PMMA at T 0 =170 °C while for a blend of 5 vol% unmodified acrylic-POSS in PMMA f 0 =0.057, which corresponds to an addition of 0.47 nm 3 per added POSS molecule at ϕ =0.05. The degree of dispersion was characterized using both wide-angle X-ray diffraction (WAXD) and dynamic mechanical analysis (DMA). Diffraction patterns for both blend systems show clear evidence of phase separation at ϕ =0.20 and higher, but no significant phase separation is evident at ϕ =0.10 and lower. The storage modulus measured in DMA indicates appreciable phase separation for unmodified acrylic POSS loadings ϕ ≥0.10, while no evidence of phase separation is present in the ϕ =0.05 blend in DMA.
Canonical quantization of the generalized axial gauge

Abstract The incompatibility of the constraint A3=0 with canonical commutation rules is discussed. A canonical formulation is given of QED and QCD in the axial gauge with n1=n2=0, n3=α and n0=β, where α and β are arbitrary real numbers. A Hilbert space is established for the perturbative theory, and a propagator is derived by obtaining an expression for the interaction picture gauge fields, and evaluating the vacuum expectation value of its time-ordered products in the perturbative vacuum. The propagator is expressed in terms of the parameter γ= α β and is shown to reproduce the light cone gauge propagator when γ=1, and the temporal gauge propagator when γ=0, accommodating various prescriptions for the spurious propagator pole, including the Mandelstam-Leibbrandt and principal value prescriptions. When γ→∞, the generalized axial gauge propagator leads to an expression for the propagator in the A3=0 gauge, though in that case the order in which the integration over k0 is performed, and the limit γ→∞ is taken, affects the resulting expression. Another Hilbert space is established, in which the constraints that include all interactions are implemented in a time independent fashion. It is pointed out that this Hilbert space, and the Hilbert space of the perturbative theory are unitarily equivalent in QED, but they cannot be unitarily equivalent in QCD. Implications of this fact for the nonperturbative states of QCD are discussed.
VITA measurements of transition in transitional hypersonic boundary layer flows

The variable interval time-averaging (VITA) technique is applied to the hot-wire measurements made in three axisymmetric, transitional hypersonic boundary layers. The average duration of conditionally sampled events is used to detect the transition region. It is found that the stability Reynolds number at the peak in the average duration of conditionally sampled events correlates well with the stability Reynolds number that is intermediate to the onset of transition and peak heating. This VITA-identified location of transition moves upstream under the effects of both an adverse pressure gradient and wall cooling; this agrees with previous experimental and computational studies. The VITA technique, therefore, offers an alternative method to obtain details of the location of transition in hypersonic stability experiments, in which hot-wire measurements of the transitioning boundary layers are made.
Minimizing makespan in hybrid flowshops

We consider flowshop environments that consist of multiple stages and multiple machines in each stage. The flowshops are flexible in the sense that a task within a stage can be processed by any of the machines in the stage. We refer to this design as the hybrid flowshop. Our objective is to schedule a set of n jobs so as to minimize makespan. The problem is N P-complete even in the case of a single stage. We develop a heuristic H for the 2-stage hybrid flowshop that has complexity O (n log n) (where n is the number of jobs) and an error bound of 2 -1/max {m"1, m"2} (where m"i is the number of machines at stage i, i = 1, 2). This bound extends a recent bound for the case m"1 = 1, m"2 = m and significantly improves all other results that have been developed for some special cases of the 2-stage hybrid flowshop. We develop five new lower bounds which are used in a computational experiment to show that the relative gap of H from optimality is small. We extend H to the case of more than two stages. We perform error bound analysis on the resulting heuristic H' whose complexity is O (kn log n) (where k is the number of stages). This is the first error bound analysis for the general hybrid flowshop problem and extends the current best error bound for the traditional k-machine flowshop problem.
Rheumatic pericarditis with effusion in patients under two years of age

Summary Pericarditis with effusion in two patients below the age of 2 years is reported as being of rheumatic etiology.
Tumor Necrosis Factor-α-Mediated Suppression of Adipocyte Apolipoprotein E Gene Transcription: Primary Role for the Nuclear Factor (NF)-κB Pathway and NFκB p50

The adipose tissue inflammation accompanying obesity has important consequences for adipocyte lipid metabolism, and increased adipose tissue TNFα plays an important role for mediating the effect of inflammation on adipocyte function. Recent studies have shown that apolipoprotein E (apoE) is highly expressed in adipose tissue where it plays an important role in modulating adipocyte triglyceride metabolism, triglyceride mass, and adipocyte size. We have previously reported that TNFα reduces adipocyte apoE, and the current studies were undertaken to evaluate the molecular mechanism for this regulation. TNFα repression of adipocyte apoE gene expression required an intact nuclear factor (NF)-κB binding site at −43 in the apoE promoter. Site-directed mutagenesis at this site completely eliminated TNFα regulation of an apoE gene reporter. TNFα treatment activated binding of NFκB p50, isolated from adipocyte nuclei, to the apoE promoter. Two structurally distinct inhibitors of NFκB complex activation or translocation abrogated the TNFα effect on the apoE gene. Using chromatin immunoprecipitation assays, we demonstrated that treatment of adipocytes with TNFα led to increased binding of NFκB p50, and decreased binding of p65 and Sp1, to this region of the apoE promoter in living cells. The key role played by increased p50 binding was confirmed by p50 knockdown experiments. Reduction of p50 expression using small interference RNA completely eliminated TNFα-mediated reduction of endogenous adipocyte apoE gene expression. These results establish the molecular link between adipose tissue inflammation and apoE gene expression in adipocytes. The suppression of adipocyte apoE by the proinflammatory adipose tissue milieu associated with obesity will have important downstream effects on adipocyte triglyceride turnover and content.
Sera from preeclamptic women specifically activate human umbilical vein endothelial cells in vitro: morphological and biochemical evidence.

: Endothelial cell dysfunction could explain many of the pathophysiological changes observed in preeclampsia. Markers of endothelial cell activation including increased circulating Von Willebrand factor (VWF) and cellular fibronectin (cFN) antedate clinically evident disease. We have therefore proposed that alteration of endothelial cell function by circulating agent(s) produced by the placenta initiates the clinical syndrome. This hypothesis predicts that there are a factor(s) in the blood of women with preeclampsia that are capable of altering endothelial cell function. We and others have examined in vitro interactions of maternal serum and endothelial cells to test this hypothesis. Our initial report indicating increased release of [51Cr]chromate from human umbilical vein endothelial cells (HUVE) suggested a lethal, lytic effect of serum from preeclamptic women. However, more specific indicators of endothelial cell structure and function do not support such a nonspecific effect. The morphology of HUVE was minimally altered after exposure to sera of preeclamptic women, and the entry of propidium iodide entry into cells, a sensitive indicator of membrane integrity, also was not increased. These findings, in combination with the increased expression of mRNA for platelet-derived growth factor (PDGF), suggest endothelial cell activation rather than cell death in response to sera from preeclamptic women. Comparison of the effects of endotoxin and sera from preeclamptic women also supports the specificity of this response. Whereas endotoxin strikingly increased VWF on the surface of HUVE and tissue factor activity in conditioned media while minimally increasing cFN, preeclamptic sera increased cFN but had no demonstrable effect on VWF or tissue factor activity. Thus, under the conditions of our in vitro assays, sera from preeclamptic women are not diffusely toxic but rather act selectively on specific activation pathways.
An experimental overview of the effects of hydrogen impurities on polymer electrolyte membrane fuel cell performance

Abstract Hydrogen quality is critical for increasing the reliability, stability, and durability of polymer electrolyte (PEM) fuel cells. In this work, several hydrogen impurities have been studied to understand their effects on PEM fuel cell performance at various operating concentrations. Our studies have shown that the following impurities suggested by industry stakeholders do not result in substantial fuel cell degradation when they are the sole impurity in hydrogen: 5 ppm formaldehyde, 2 ppm formic acid, 19 ppm chloromethane, 30 ppm acetaldehyde, 5% ethylene, 20 ppm toluene, and 10 ppm benzene. In addition, a specific mixture of impurities called the “specification concentration level cocktail” consisting of 0.2 ppm carbon monoxide, 4 ppb hydrogen sulphide, 0.2 ppm formic acid, 2 ppm benzene, and 0.1 ppm ammonia in hydrogen, also does not show significant effects on cell performance. In comparison, when a cocktail having five times the specification concentration is introduced into the cell, significant performance loss is evident.
Vector Solitons and Their Internal Oscilliations in Birefringent Nonlinear Optical Fibers

In this article, the vector solitons in birefringent nonlinear optical fibers are studied first. Special attention is given to the single-hump vector solitons due to evidences that only they are stable. Questions such as the existence, uniqueness, and total number of these solitons are addressed. It is found that the total number of them is continuously infinite and their polarizations can be arbitrary. Next, the internal oscillations of these vector solitons are investigated by the linearization method. Discrete eigenmodes of the linearized equations are identified. Such modes cause to the vector solitons a kind of permanent internal oscillations, which visually appear to be a combination of translational and width oscillations in the A and B pulses. The numerically observed radiation shelf at the tails of interacting pulses is also explained. Finally, the asymptotic states of the perturbed vector solitons are studied within both the linear and nonlinear theory. It is found that the state of internal oscillations of a vector soliton is always unstable. It invariably emits energy radiation and eventually evolves into a single-hump vector soliton state.
Somatosensory evoked potential and brain water content in post-asphyxic immature piglets

Depression of somatosensory evoked potentials (SEP) after a single episode of complete asphyxia with near cardiac arrest was evaluated to determine whether persistent SEP depression is related to postresuscitation edema in cortical gray matter or subcortical white matter. Piglets (< 7 d of age) were anesthetized with sodium pentobarbital and fentanyl. Asphyxia was produced by occlusion of the endotracheal tube for 7 min. Arterial O2 saturation fell to 5%. Resuscitation was achieved in < 2 min with ventilation, epinephrine, and chest compressions. Regional brain water content was determined from the difference between wet and dry weight. Two control groups were also analyzed; one immediately after (n = 5) and one 6 h after induction (n = 7) of anesthesia. SEP amplitude became isoelectric during asphyxia and recovered to 50 +/- 13% (n = 7) of baseline 6 h after resuscitation. In the 6-h control group, SEP amplitude remained above baseline. The percent water content (mean +/- SEM) among the three groups (asphyxia versus time control versus brief anesthesia control) was not different in the cortical gray matter (83.0 +/- 0.7% versus 82.4 +/- 0.4% versus 83.2 +/- 0.3%) or subcortical white matter (75.6 +/- 0.8% versus 74.8 +/- 0.9% versus 75.6 +/- 0.5%). In seven other piglets, cerebral blood flow and O2 consumption recovered to baseline by 1 h after asphyxia. Therefore, we found that the sustained depression of SEP amplitude, after 7 min of asphyxia in immature piglets, is not related to brain edema or persistent decreases in global cerebral O2 consumption.
Topoisomerase IIalpha mediates E2F-1-induced chemosensitivity and is a target for p53-mediated transcriptional repression.

Mutations of the retinoblastoma tumor suppressor, pRb, or its cyclin-cyclin-dependent kinase (CDK) regulatory kinases or CDK inhibitors, allows unrestrained E2F activity, leading to unregulated cell cycle progression. However, overexpression of E2F-1 also sensitizes cells to apoptosis, suggesting that targeting this pathway may be of therapeutic benefit. Enforced expression of E2F-1 in interleukin-3-dependent myeloid cells led to preferential sensitivity to the topoisomerase II inhibitor, etoposide, which was independent of p53 accumulation. Pretreatment of the E2F-1-expressing cells with ICRF-193, a second topoisomerase II inhibitor that does not cause DnA damage, protected these cells against etoposide-induced apoptosis. However, ICRF-193 cooperated with other DNA-damaging agents to induce apoptosis. Enforced expression of E2F-1 led to accumulation of p53 protein. An E2F-1 mutant that is defective in inducing cell cycle progression also induced p53, suggesting that p53 was responding directly to E2F, and not to secondary events caused by inappropriate cell cycle progression (i.e., DNA damage). Thus, topoisomerase II inhibition and DNA damage cooperate to selectively induce apoptosis in cells that have mutations in the pRb pathway.
The IRR, NPV and the Fallacy of the Reinvestment Rate Assumptions

ABSTRACT The Internal Rate of Return and Net Present Value decision criteria are probably the most well known economic decision criteria: they are also probably the most misunderstood. The ‘reinvestment rate assumptions’ attributed by some writers are two such misconceptions and they appear to be the result of a misunderstanding of two fundamental principles of economic decision making: an economic decision should be (1) based on the prospective differences in the (2) real (out-of-pocket) monetary consequences. This paper illustrates the fallacy of the ‘reinvestment rate assumptions’ numerically, mathematically, and intuitively.
Design and synthesis of β-methoxyacrylate analogues via click chemistry and biological evaluations

A library of potential antifungal triazole-modified beta-methoxyacrylate analogues was designed and synthesized via a Cu(I)-catalyzed 1,3-dipolar alkyne-azide coupling reaction or 'click chemistry'. Subsequent biological screening revealed that some compounds displayed low to moderate antifungal activity toward pathogenic fungi and low phytotoxicity.
Differing Perceptions of Job Priorities for Marketing Educators

This study tests the hypothesis that different perceptions of the relative importance of teaching, service, and research may exist between deans, marketing department heads, and marketing faculty at master's degree granting AACSB-accredited business schools. Findings indicate that significantly different perceptions of the marketing educator's role, both presently and desired, exist across organizational levels.
A comparison of the coordination preferences of Zn, Co, and Cd(II) with the heteroscorpionate ligand (2-hydroxy-3-t-butyl-methylphenyl)bis (3,5-dimethylpyrazolyl)methane

Reaction of the Zn, Cd, or Co nitrate salts with the deprotonated ligand (2-hydroxy-3-t-butyl-methylphenyl)bis(3,5-dimethylpyrazolyl)methane (L1O−) in methanol produced the following complexes: [(L1OH)Zn(NO3)2] in two isomorphs, a = 40.983(8) A, b = 9.571(2) A, c = 15.667(8) A, α = 90○, β = 106.38(1)○, γ = 90○, C2/c, and a = 13.027(3) A, b = 14.781(4) A, c = 16.107(3) A, α = 90○, β = 105.30(1)○, γ = 90○, P21/n; [(L1OH)Cd(pz)(NO3)2] a = 14.7476(2) A, b = 13.5411(2) A, c = 16.7223(2) A, α = 90○, β = 110.3840(10)○, γ = 90○, P21/c; and [(L1O)Co(pz)(NO3)] a = 11.4240(2) A, b = 13.4498(2) A, c = 13.8056(2) A, α = 105.2080(10)○, β = 105.8130(10)○, γ = 112.7470(10)○, P\({\bar 1}\). The Zn adopts a pseudotetrahedral four-coordinate geometry where the potentially tridentate ligand is actually bidentate with a protonated and uncoordinated phenoxy arm. The Co complex is pseudooctahedral six-coordinate where the phenoxy arm is deprotonated and coordinated. Finally the Cd complex is seven-coordinate but the metal is not coordinated through the phenoxy group that is again protonated.
Craving cocaine pERKs up the amygdala

In a rat model of cocaine craving, a new study shows that activation of the protein kinase ERK in the amygdala is necessary and sufficient for the growth of craving over time in withdrawal. The combination of experimental approaches used by these authors will serve as a model for future studies examining the molecular mechanisms underlying a cognitive or behavioral process.
Nonfundamentals and value returns

The study examines additions to and deletions from the Russell Value Index and the Russell 2000 Growth Index. The study documents stronger comovement in value reconstitutions relative to growth reconstitutions. This result is consistent with the hypothesis that nonfundamental comovement is related to the common factor in value stock returns. The mechanism of causality is difficult to determine, however; trade demand, firm characteristics and information diffusion are presented as potential sources that could explain why comovement of small to mid-cap value stocks is greater than the comovement of small to mid-cap growth stocks.
Assessing information technology personnel: toward a behavioral rating scale

Performance ratings are used as a means to measure and record performance of individuals on any particular job. Results can then be used for promotion, increases in pay and other incentives. They, therefore, can have a large impact on a person's career and are viewed by both employers and employees as extremely important. Performance ratings vary widely and typically include a variety of measures - some of which the employee can control, and others over which the employee has no direct control. Overall, the various types of performance ratings are not perfect; each has its flaws along with its advantages. In this study, one particular type of scale - a behavioral rating scale - is proposed by taking the results of a previous study performed by Green (1989) and empirically testing a set of critical skills for use as a performance assessment instrument for information technology (IT) personnel. The instrument is provided for researchers who wish to incorporate a behavior-oriented measure in their research and for practitioners who may be looking for a behavior-oriented scale to evaluate IT personnel. The psychometric properties of the instrument as observed in this study are also presented.
Three-dimensional drawings in isometric conditions: planar segmentation of force trajectory

Normal human subjects grasped an isometric handle with an unrestrained, pronated hand. They were asked to exert forces continuously to draw lemniscates (figure eights) in specified or self-chosen planes and in the presence or absence of a three-dimensional visual feedback cursor and a visual template. In every condition, the mean plane orientation in the force space differed appreciably between the two loops of the figure, as described previously by Soechting and Terzuolo (1987a) for free drawing arm movements. These findings suggest that the planar segmentation of the motor trajectory is not a consequence of joint motion but arises from central constraints related to the production of motor trajectory in space.
Statistical comparison between inductively coupled plasma-mass spectrometry, and Hall effect techniques using antimony-doped germanium

Abstract Two independent characterization techniques, Hall effect, and inductively coupled plasma-mass spectrometry (ICP-MS) were used to measure the antimony (Sb) concentration in antimony-doped germanium single crystals and then these results were directly compared to each other. The three single liquid-encapsulated Czochralski-grown crystals had initial concentrations ranging from 1×10 15 to 1×10 17 at/cm 3 Sb. The reproducibility of the ICP-MS measurements was quantified and an estimate of error was obtained using a reproducibility study and a components of variation study for the concentration range of the crystals investigated. The total average error for the ICP-MS measurements was found to be 8.66% with a future prediction interval of ±14.22%. The two techniques were shown to be statistically significantly correlated with each other. The ICP-MS and the Hall effect techniques had nearly identical agreement when these two techniques were directly compared to each other.
Enzymatic basis for increased expression of GD3 on human melanoma cells derived from metastatic lesions

The expression of disialoganglioside GD3 is examined in human melanoma cell lines derived from primary (WM 115 and WM 75) or metastatic (WM 266 and WM 373) lesions resected from the same two patients. GD3 is demonstrated to be preferentially expressed by the metastatic cell lines relative to their primary cell line counterparts as shown by thin layer chromatography and flow cytometric analysis. The enhanced expression of GD3 in the metastatic cell lines is due to the increased activity of its biosynthetic enzyme, cytidine-5′-monophospho-N-acetylneuraminic acid:GMS sialyltransferase (GD3 synthetase), as evident from assays of GD3 synthetase activity of these cell lines. The activity of this enzyme in membrane extracts of all 4 cell lines is dependent on protein concentration and time, with peak activity occurring after 30 min. GD3 synthetase in both WM 115 and WM 266 exhibits a relatively broad pH optima between 6.2 and 6.6, is stimulated by Mn2+ and Mg2+, and inhibited by EDTA and Hg2+. Subcellular fractionation indicates that GD3 synthetase activity is localized primarily within the Golgi-enriched fraction. The enhanced expression of GD3 on the metastatic melanoma cell lines WM 266 and WM 373 relative to that of their primary cell line counterparts cannot be attributed to blocked synthesis of other gangliosides utilizing GD3 as a precursor, but is primarily due to the increased activity of GD3 synthetase.
In utero exposure to benzophenone-2 causes hypospadias through an estrogen receptor dependent mechanism.

Purpose: Additives such as benzophenone-2 are commonly used in cosmetic products and food container plastics to filter out ultraviolet light. In pregnant women exposure may result in transplacental transfer of benzophenone-2 to fetuses. Benzophenone-2 is estrogenic in vitro and in the rat uterotropic assay. Estradiol causes hypospadias in mice and estrogen-like compounds are also postulated to cause hypospadias. We determined whether hypospadias would develop in male mice exposed to benzophenone-2 in utero and whether this outcome depended on estrogen receptor pathways.Materials and Methods: Timed pregnant C57BL/6 mice were administered benzophenone-2 (6.25 mg) or control vehicle by oral gavage from gestational days 12 through 17 and they were sacrificed on day 18. Fetuses were weighed and sexed, anogenital distance was measured and genital tubercles were harvested for paraffin sections or quantitative reverse transcriptase-polymerase chain reaction analysis of genes purportedly involved in genital tuberc...
Body weight, static and dynamic skinfold thickness in small premature infants during the first month of life

Abstract The growth of prematurely born infants is different from the growth of fetuses of the same age remaining in utero. This is in part due to changes in body composition that occur after birth. In search for a practical and reliable method to assess the growth of small prematures, we analyzed data obtained in two anthropometric studies that included 180 premature infants of 750–1750 g weight at birth, and we studied the relationships between weight, static skinfold thickness (SSFT) and dynamic skinfold thickness (ΔSFT, i.e. the percentage of change in skinfold thickness between 15 and 60 s after application of the Harpenden caliper). The results show that the SSFT increases steadily after birth in spite of a significant decrease in weight and ΔSFT. Whether it contains fat or not, the fold of the skin is increasing in thickness at a time when by weight alone, one would have considered that there was no growth. The nutritional implication of this finding remains to be studied. Serial correlations of measures obtained at each period indicate that weight and SSFT have a good correlation to same measures in subsequent weeks (P
Control of Curvature in Highly Compliant Probe Cantilevers during Carbon Nanotube Growth

Direct growth of a sharp carbon nanotube (CNT) probe on a very thin and highly flexible cantilever by plasma-enhanced chemical vapor deposition (PECVD) is desirable for atomic force microscopy (AFM) of nanoscale features on soft or fragile materials. Plasma-induced surface stresses in such fabrication processes, however, tend to cause serious bending of these cantilevers, which makes the CNT probe unsuitable for AFM measurements. Here, we report a new tunable CNT growth technique that controls cantilever bending during deposition, thereby enabling the creation of either flat or deliberately curved AFM cantilevers containing a CNT probe. By introducing hydrogen gas to the (acetylene + ammonia) feed gas during CNT growth and adjusting the ammonia to hydrogen flow ratio, the cantilever surface stress can be altered from compressive to tensile stress, and in doing so controlling the degree of cantilever bending. The CNT probes grown under these conditions have high aspect ratios and are robust. Contact-mode imaging has been demonstrated using these probe tips. Such CNT probes can be useful for bio-imaging involving DNA and other delicate biological features in a liquid environment.
Altered cerebral glucose and acetate metabolism in succinic semialdehyde dehydrogenase-deficient mice: evidence for glial dysfunction and reduced glutamate/glutamine cycling.

Succinic semialdehyde dehydrogenase (SSADH) catalyzes the NADP-dependent oxidation of succinic semialdehyde to succinate, the final step of the GABA shunt pathway. SSADH deficiency in humans is associated with excessive elevation of GABA and c-hydroxybutyrate (GHB). Recent studies of SSADH-null mice show that elevated GABA and GHB are accompanied by reduced glutamine, a known precursor of the neurotransmitters glutamate and GABA. In this study, cerebral metabolism was investigated in urethane-anesthetized SSADH-null and wild-type 17-day-old mice by intraperitoneal infusion of [1,6- 13 C2]glucose or [2- 13 C]acetate for different periods. Cortical extracts were prepared and measured using high-resolution 1 H-[ 13 C] NMR spectroscopy. Compared with wild-type, levels of GABA, GHB, aspartate, and alanine were significantly higher in SSADH-null cortex, whereas glutamate, glutamine, and taurine were lower. 13 C Labeling from