cssi/SciSciGPT-SciSciNet huggingface dataset:
Extensive tyrosine nitration in human myocardial inflammation: evidence for the presence of peroxynitrite.

Objectives Production of nitric oxide via the cytokine-mediated activation of myocardial inducible nitric oxide synthase decreases myocardial contractility. Whether myocardial dysfunction is mediated directly by nitric oxide or indirectly through the formation of secondary reaction products, such as peroxynitrite, has not been established. Peroxynitrite, but not nitric oxide, reacts with the phenolic ring of tyrosine to form the stable product 3-nitro-L-tyrosine. Demonstration of tissue nitrotyrosine residues, therefore, infers the presence of peroxynitrite or related nitrogencentered oxidants. Design Retrospective analysis of human autopsy specimens. Setting University pathology and basic science laboratories. Patients Formalin-fixed, paraffin-embedded myocardial tissue samples were obtained from 11 patients with a diagnosis of sepsis, seven patients with a diagnosis of viral myocarditis, and five control patients without clinical or pathologic cardiac disease. Interventions None. Measurements and Main Results Specific antibodies to nitrotyrosine were utilized to detect nitrotyrosine residues in human autopsy specimens. Cardiac tissue obtained from patients with myocarditis or sepsis demonstrated intense nitrotyrosine immunoreactivity in the endocardium, myocardium, and coronary vascular endothelium and smooth muscle. In contrast, connective tissue elements were without appreciable immunohistochemical staining. Nitrotyrosine antibody binding was blocked by coincubation with nitrotyrosine or nitrated bovine serum albumin, but not by aminotyrosine, phosphotyrosine, or bovine serum albumin. In situ reduction of tissue nitrotyrosine to aminotyrosine by sodium hydrosulfite also blocked antibody binding. Densitometric analysis of nitrotyrosine immunoreactivity demonstrated significantly higher values for specimens from myocarditis and sepsis patients when compared with control tissue specimens. Conclusion These results demonstrate the formation of peroxynitrite within the myocardium during inflammatory disease states, suggesting a role for peroxynitrite in inflammation-associated myocardial dysfunction. (Crit Care Med 1997; 25:812-819)
Spectre d'absorption de Yb I

Soixante-treize raies d'absorption de l'ytterbium ont ete mesurees dans la region ultraviolette 1 980-2 300 A. Les raies sont interpretees comme etant les transitions entre le niveau fondamental 6s2 1S0 et les niveaux 1P1 et 3P1 des configurations excitees 6s np de Yb I. L'etude de la serie de Rydberg 6s2 1 S0-6s np1P1 pour n variant de 6 a 48 conduit a la valeur de 50 441,0 ± 0,2 cm-1 pour sa limite qui est le niveau fondamental 6s 2S 1/2 de Yb II. Le potentiel d'ionisation de Yb I est donc de : 6,2537 ± 0,0002 volts, la precision etant limitee par la determination du facteur de conversion 8 065,73 ± 0,23 cm-1/eV.
Use of Albumin as a Volume Expander

In some hospitals, albumin products account for 10% of the pharmaceutical budget.4 As much as 60% of these prescriptions are empiric, and from 40 to 70% of albumin that is administered is given for inappropriate reasons.4-6,14,15 Although the reasons for albumin administration vary, prevention or reversal of hypovolemia is part of the reason in the majority of cases. (Journal of Parenteral and Enteral Nutrition 15:484-487, 1991)
Pressure/temperature interactions in relation to development of high pressure convulsions in ectotherm vertebrates

Abstract 1. 1. The effects of varying test temperature ( T 1 ) and acclimation temperature ( T a upon the threshold pressure eliciting HPNS convulsions ( P c ) were measured in three representative ectotherm vertebrates. 2. 2. Test temperature had little effect on P c . 3. 3. Changes in T a gave rise to three distinct species-specific patterns. 4. 4. In the fish, marked negative correlation between P c and T a ; in the newt, a well-defined maximum P c at T a close to habitat temperature; and a P c virtually independent of T a in the lizard. 5. 5. The data revealed an unexpected degree of complexity in P / T interactions with respect to CNS function; specifically, they failed to bear out predictions from analyses of simplified model systems that high pressure effects on excitable tissues should be opposed by increased temperatures.
Kinetics of Ru-catalyzed sodium borohydride hydrolysis

Abstract Chemical hydrides have been identified as a potential medium for on-board hydrogen storage, one of the most challenging technical barriers to the prospective transition from gasoline to hydrogen-powered vehicles. Systematic study of the feasibility of the sodium borohydride systems, and chemical-hydride systems more generally, requires detailed kinetic studies of the reaction for use in reactor modeling and system-level experiments. This work reports an experimental study of the kinetics of sodium borohydride hydrolysis with a Ru-on-carbon catalyst and a Langmuir-Hinshelwood kinetic model developed based on experimental data. The model assumes that the reaction consists of two important steps: the equilibrated adsorption of sodium borohydride on the surface of the catalyst and the reaction of the adsorbed species. The model successfully captures both the reaction's zero-order behavior at low temperatures and the first-order behavior at higher temperatures. Reaction rate constants at different temperatures are determined from the experimental data, and the activation energy is found to be 66.9 kJ mol −1 from an Arrhenius plot.
Toxoplasma gondii Purine Nucleoside Phosphorylase Biochemical Characterization, Inhibitor Profiles, and Comparison with the Plasmodium falciparum Ortholog

Abstract Purine nucleoside phosphorylase (PNP) is an important component of the nucleotide salvage pathway in apicomplexan parasites and a potential target for drug development. The intracellular pathogen Toxoplasma gondii was therefore tested for sensitivity to immucillins, transition state analogs that exhibit high potency against PNP in the malaria parasite Plasmodium falciparum. Growth of wild-type T. gondii is unaffected by up to 10 μm immucillin-H (ImmH), but mutants lacking the (redundant) purine salvage pathway enzyme adenosine kinase are susceptible to the drug, with an IC50 of 23 nm. This effect is rescued by the reaction product hypoxanthine, but not the substrate inosine, indicating that ImmH acts via inhibition of T. gondii PNP. The primary amino acid sequence of TgPNP is >40% identical to PfPNP, and recombinant enzymes exhibit similar kinetic parameters for most substrates. Unlike the Plasmodium enzyme, however, TgPNP cannot utilize 5′-methylthio-inosine (MTI). Moreover, TgPNP is insensitive to methylthio-immucillin-H (MT-ImmH), which inhibits PfPNP with a of 2.7 nm. MTI arises through the deamination of methylthio-adenosine, a product of the polyamine biosynthetic pathway, and its further metabolism to hypoxanthine involves PfPNP in purine recycling (in addition to salvage). Remarkably, analysis of the recently completed T. gondii genome indicates that polyamine biosynthetic machinery is completely lacking in this species, obviating the need for TgPNP to metabolize MTI. Differences in purine and polyamine metabolic pathways among members of the phylum Apicomplexa and these parasites and their human hosts are likely to influence drug target selection strategies. Targeting T. gondii PNP alone is unlikely to be efficacious for treatment of toxoplasmosis.
Aggregation and reactivity of the cesium enolate of 6-phenyl-alpha-tetralone: comparison with the lithium enolate.

The cesium enolate of 6-phenyl-α-tetralone (CsPAT) has a λmax in THF at about 387 nm, but the variation with concentration is too small for application of singular value decomposition. Proton-transfer studies with several indicators show that CsPAT forms monomer−tetramer mixtures with a tetramerization equilibrium constant, K1,4 = 2.3 × 1011 M-3. The pK of the monomer is 23.39 on a scale where fluorene is assigned 22.9 (per hydrogen). For comparison, the lithium enolate, LiPAT, is also a monomer−tetramer with K1,4 = 4.7 × 1010 M-3 and a monomer pK = 14.22. HMPA in large amounts promotes dissociation to monomer with both enolates. Ion-pair SN2 initial rates were measured for CsPAT with several alkyl halides and with methyl tosylate and compared with other rates with LiPAT. In all cases, the enolate monomers are much more reactive than the aggregates. Reaction of CsPAT with alkyl halides is generally C-alkylation but HMPA promotes increasing amounts of O-alkylation. A new indicator, 11-methyl-11H-benzo[b]fl...
Endothelial cell-based systemic gene therapy of metastatic melanoma.

Cancer metastasis accounts for a significant proportion of morbidity and mortality in patients. Effective means of treating disseminated disease remains elusive. The purpose of this study was to determine whether genetically modified endothelial cells (GMEC) can selectively target and deliver recombinant therapeutic molecules to sites of tumor metastases. Following the establishment of lung metastases of 4T1 mammary tumor in mice, intravenously (i.v.) administered, lacZ transgene–expressing endothelial cells ( lacZ -GMEC) accumulated at the tumor sites. An average of 32% and 90% of the pulmonary metastases were X-gal stained following one and three tail vein injections of 105 lacZ -GMEC, respectively. The linear pattern of X-gal staining seen within the tumor sites and the histological appearance of the tumor vasculature were consistent with the incorporation of lacZ -GMEC into blood vessels. In C57Bl/6 mice harboring lung metastases of melanoma, the administration of three sequential i.v. injections of 105 endothelial cells expressing a human interleukin 2 transgene abrogated the tumor metastases and prolonged survival of the animals. These results demonstrate that i.v.-administered GMEC can selectively accumulate, survive, and stably express exogenous genes at multiple tumor sites. These findings support a role for i.v.-administered GMEC as a potential therapeutic strategy for the systemic treatment of cancer metastases. Cancer Gene Therapy (2001) 8, 636–648.
Southern Ocean biogeochemical impact on the tropical ocean: Stable isotope records from the Pacific for the past 25,000 years

Abstract Modeling of oceanic nutrient fields indicates that the Southern Ocean may have a strong impact on the chemistry of the thermocline waters which upwell in the eastern tropical oceans and feed biological productivity there. The subantarctic is a primary source of equatorial undercurrent (EUC) waters. The Southern Ocean to equator connection has been shown through modeling to have a potential influence on atmospheric carbon dioxide content via an increase in the efficiency of the tropical biotic pump (silica leakage hypothesis). On the glacial–interglacial timescale the eastern equatorial Pacific (EEP) has a thermocline (EUC) carbon isotope record which is consistent with that idea and a stronger ice age biologic drawdown in the subantarctic. This carbon isotope record features glacial values more positive than those of the Holocene, which is the reverse of what is seen in the non-equatorial, stratified, ocean. We report planktonic carbon isotope records from the Pacific subantarctic in an effort to trace the unique EEP carbon isotope signature to its source. Our results are compatible with the subantarctic as a source of the tropical carbon isotope signature. Analysis of the glacial to Holocene isotopic pattern in terms of causative process indicates that an increased glacial subantarctic biotic pump accounts best for our observations. This supports the hypothesis of Southern Ocean drive on tropical biological production, and potential impact on the global carbon cycle.
Experimental studies of particle ingestion by the sand fiddler crab Uca pugilator (Bosc)

Abstract Particle ingestion by the sand fiddler crab Uca pugilator (Bosc) was investigated using clean sand sediment inoculated with glass and plastic beads. For all bead types, the number ingested was positively correlated with the initial sediment bead concentration. Ingestion efficiency, however, was inversely correlated with bead diameter, weight, and initial sediment bead concentration. The latter result suggests that the particle sorting mechanism can be saturated at high substratum particle concentrations. Crab size was directly related to the efficiency at which large beads were ingested, but had no effect on the ingestion of small beads. Ciliates, unbound bacteria, and bacteria attached to sand grains were ingested with high efficiency, but the crabs did not preferentially ingest live over inert particles. Other results suggest that maximization of food intake by sand fiddlers occurs at the habitat patch level rather than at the level of particle ingestion. Supporting this view is the observation that inert particles which were ingested with high efficiencies did not stimulate crab feeding. Sediment harvesting rates were inversely related to substratum organic and silt concentrations suggesting that sand fiddlers can control ingestion rates by regulating sediment harvesting rates
Reactive oxygen species and mitochondrial diseases.

A variety of diseases have been associated with excessive reactive oxygen species (ROS), which are produced mostly in the mitochondria as byproducts of normal cell respiration. The interrelationship between ROS and mitochondria suggests shared pathogenic mechanisms in mitochondrial and ROS-related diseases. Defects in oxidative phosphorylation can increase ROS production, whereas ROS-mediated damage to biomolecules can have direct effects on the components of the electron transport system. Here, we review the molecular mechanisms of ROS production and damage, as well as the existing evidence of mitochondrial ROS involvement in human diseases.
Sparse code generation for imperfectly nested loops with dependences

Standard restructuring compiler tools are based on polyhe dral algebra and cannot be used to analyze or restructure sparse matrix codes We have recently shown that tools based on relational algebra can be used to generate an e cient sparse matrix program from the corresponding dense matrix program and a speci cation of the sparse matrix for mat This work was restricted to DO ALL loops and loops with reductions In this paper we extend this approach to loops with dependences Although our results are restricted to Compressed Hyperplane Storage formats they apply to both perfectly nested loops and imperfectly nested loops
IL-11 separates graft-versus-leukemia effects from graft-versus-host disease after bone marrow transplantation

We recently showed that IL-11 prevents lethal graft-versus-host disease (GVHD) in a murine bone marrow transplantation (BMT) model of GVHD directed against MHC and minor antigens. In this study, we have investigated whether IL-11 can maintain a graft-versus-leukemia (GVL) effect. Lethally irradiated B6D2F1 mice were transplanted with either T cell-depleted (TCD) bone marrow (BM) alone or with BM and splenic T cells from allogeneic B6 donors. Animals also received host-type P815 mastocytoma cells at the time of BMT. Recipients were injected subcutaneously with recombinant human IL-11 or control diluent twice daily, from 2 days before BMT to 7 days after BMT. TCD recipients all died from leukemia by day 23. All control- and IL-11-treated allogeneic animals effectively rejected their leukemia, but IL-11 also reduced GVHD-related mortality. Examination of the cellular mechanisms of GVL and GVHD in this system showed that IL-11 selectively inhibited CD4-mediated GVHD, while retaining both CD4- and CD8-mediated GVL. In addition, IL-11 treatment did not affect cytolytic effector functions of T cells after BMT either in vivo or in vitro. Studies with perforin-deficient donor T cells demonstrated that the GVL effect was perforin dependent. These data demonstrated that IL-11 can significantly reduce CD4-dependent GVHD without impairing cytolytic function or subsequent GVL activity of CD8(+) T cells. Brief treatment with IL-11 shortly after BMT may therefore represent a novel strategy for separating GVHD and GVL.
Neural representation of consciously imperceptible speech sound differences.

The concept of subliminal perception has been a subject of interest and controversy for decades. Of interest in the present investigation was whether a neurophysiologic index of stimulus change could be elicited to speech sound contrasts that were consciously indiscriminable. The stimuli were chosen on the basis of each individual subject’s discrimination threshold. The speech stimuli (which varied along anF3 onset frequency continuum from /da/ to /ga/) were synthesized so that the acoustical properties of the stimuli could be tightly controlled. Subthreshold and suprathreshold stimuli were chosen on the basis of behavioral ability demonstrated during psychophysical testing. A significant neural representation of stimulus change, reflected by the mismatch negativity response, was obtained in all but 1 subject in response to subthreshold stimuli. Grand average responses differed significantly from responses obtained in a control condition consisting of physiologic responses elicited by physically identical stimuli. Furthermore, responses to suprathreshold stimuli (close to threshold) did not differ significantly from subthreshold responses with respect to latency, amplitude, or area. These results suggest that neural representation of consciously imperceptible stimulus differences occurs and that this representation occurs at a preattentive level.
Structural analysis of the Pt(110)-( 1×2 ) surface using medium-energy ion scattering

We have studied the geometrical structure of the Pt(110) surface using medium-energy ion scattering. We find that the structure of the reconstructed (1\ifmmode\times\else\texttimes\fi{}2) unit cell corresponds to a missing-row model with, in contrast to previous reports, a large contraction of the first interlayer spacing, and a buckling of the third layer. The model, which includes deep distortions, is very similar to the one recently established for Au(110)-(1\ifmmode\times\else\texttimes\fi{}2). In addition, we have observed the CO-induced (1\ifmmode\times\else\texttimes\fi{}1) phase, and find that it is well described as a disordered surface.
Studies in biogeochemistry—I A biogeochemical periodic table. The data

Abstract Information of interest in biology, geology and chemistry has been collected from the literature and summarized in a biogeochemical periodic table. Available data on abundance, geochemical character, nutritional importance, electronegativity, complexing tendency, oxidation state, covalent and/or ionic radius, ionic potential and ionization potential are reported for each element.
NASA Rotor 37 CFD Code Validation: Glenn-HT Code

In order to advance the goals of NASA aeronautics programs, it is necessary to continuously evaluate and improve the computational tools used for research and design at NASA. One such code is the Glenn-HT code which is used at NASA Glenn Research Center (GRC) for turbomachinery computations. Although the code has been thoroughly validated for turbine heat transfer computations, it has not been utilized for compressors. In this work, Glenn-HT was used to compute the flow in a transonic compressor and comparisons were made to experimental data. The results presented here are in good agreement with this data. Most of the measures of performance are well within the measurement uncertainties and the exit profiles of interest agree with the experimental measurements.
A Programmable Data Acquisition Interface

An on-line data acquisition and analysis system has recently been placed in operation to support the research programs at the Texas A&M University Variable Energy Cyclotron facility. The system consists of an IBM 7094 computer and a programmable experiment-computer interface unit. The interface is a logical extension of the computer system, thereby insuring hardware and software compatibility.
Phorbol esters down-regulate protein kinase C in rat brain cerebral cortical slices.

The effect of phorbol esters on cyclic AMP production in rat cerebral cortical slices was studied using a prelabelling technique to measure cyclic nucleotide accumulation. Cholera toxin-stimulated cyclic AMP accumulation was enhanced approximately 2-fold by phorbol 12-myristate, 13-acetate (PMA) which alone had no effect on cyclic AMP production. The augmentation by PMA was maximal within the first hour of incubation, decreasing progressively thereafter. Protein kinase C activity was decreased 80–90% during a 3 hr exposure to PMA, as was 3H-phorbol 12,13-dibutyrate binding. Both phosphatidyl serine and arachidonic acid were found to enhance protein kinase C activity in a concentration-dependent manner, an effect that was attenuated by prolonged incubation of the brain tissue with PMA. The results indicate that exposure of brain slices to phorbol esters causes a down-regulation of rat brain protein kinase C, and that this modification corresponds with a decrease in the ability of PMA to augment cyclic AMP production, suggesting a functional relationship between the two systems in rat brain.
Hormone-sensitive lipase of rat adipose tissue correlation of activity with a protein of molecular weight 84 000

Hormone-sensitive lipase of rat adipose tissue was partially purified. The enzyme retained its capacity to be activated by cyclic AMP-dependent protein kinase throughout purification. When the partially purified 32P-labeled preparation was subjected to two-dimensional gel electrophoresis, the enzyme activity was found to be associated with a 32P-labeled protein of molecular weight 84 000. The result suggests that this 32P-labeled protein represents hormone-sensitive lipase or the catalytic subunit of the enzyme.
Mycoplasma orale infection affects K+ and Cl- currents in the HSG salivary gland cell line.

The relations between K+ channel and Cl− channel currents and mycoplasma infection status were studied longitudinally in HSG cells, a human submandibular gland cell line. The K+ channel currents were disrupted by the occurrence of mycoplasma infection: muscarinic activation of K+ channels and K+ channel expression as estimated by ionomycin- or hypotonically induced K+ current responses were all decreased. Similar decreases in ionomycin- and hypotonically induced responses were observed for Cl− channels, but only the latter decrease was statistically significant. Also, Cl− currents could be elicited more frequently than K+ currents (63% of cases versus 0%) in infected cells when tested by exposure to hypotonic media, indicating that mycoplasma infection affects K+ channels relatively more than Cl− channels. These changes occurred in the originally infected cells, were ameliorated when the infection was cleared with sparfloxacin, and recurred when the cells were reinfected. Such changes would be expected to result in hyposecretion of salivary fluid if they occurredin vivo.
Mothers’ Infant-Directed Gaze During Object Demonstration Highlights Action Boundaries and Goals

When demonstrating objects to young children, parents use specialized action features, called “motionese,” which elicit attention and facilitate imitation. We hypothesized that the timing of mothers' infant-directed eye gaze in such interactions may provide systematic cues to the structure of action. We asked 35 mothers to demonstrate a series of tasks on objects to their 7- and 12-mo-old infants, with three objects affording enabling sequences leading to a salient goal, and three objects affording arbitrary sequences with no goal. We found that mothers' infant-directed gaze was more aligned with action boundary points than expected by chance, and was particularly tightly aligned with the final actions of enabling sequences. For 7- but not 12-mo-olds, mothers spent more time with arbitrary than enabling-sequence objects, and provided especially tight alignment for action initiations relative to completions. These findings suggest that infants may be privy to patterns of information in mothers' gaze which signal action boundaries and particularly highlight action goals, and that these patterns shift based on the age or knowledge state of the learner.
Current Status of Thymosin Research: Evidence for the Existence of a Family of Thymic Factors that Control T-Cell Maturation

Thymosin fraction 5 contains several distinct hormonal-like factors which are effective in partially or fully inducing and maintaining immune function. Several of the peptide components of fraction 5 have been purified, sequenced and studied in assay systems designed to measure T-cell differentiation and function. These studied indicate that a number of the purified peptides act on different subpopulations of T-cells (see Figure 1). Thymosin beta 3 and beta 4 peptides act on terminal deoxynucleotidyl transferase (TdT) negative precursor T-cells to induce TdT positive cells. Thymosin alpha 1 induces the formation of functional helper cells and conversion of Lyt- cells to Lyt 1+, 2+, 3+ cells. Thymosin alpha 7 induces the formation of functional suppressor T-cells and also converts Lyt- cells to Lyt 1+, 2+, 3+ cells. These studies have provided further evidence that the thymus secretes a family of distinct peptides which act at various sites of the maturation sequence of T-cells to induce and maintain immune function. Phase I and Phase II clinical studied with thymosin in the treatment of primary immunodeficiency diseases, autoimmune diseases, and cancer point to a major role of the endocrine thymus in the maintenance of immune balance and in the treatment of diseases characterized by thymic malfunction. It is becoming increasingly clear that immunological maturation is a process involving a complex number of steps and that a single factor initiating a single cellular event might not be reflected in any meaningful immune reconstitution unless it is the only peptide lacking. Given the complexity of the maturation sequence of T-cells and the increasing numbers of T-cell subpopulations that are being identified, it would be surprising if a single thymic factor could control all of the steps and populations involved. Rather, it would appear that the control of T-cell maturation and function involves a complex number of thymic-specific factors and other molecules that rigidly control the intermediary steps in the differentiation process.
The membrane skeleton of erythrocytes. A percolation model

The spectrin network on the cytoplasmic surface of the erythrocyte membrane is modeled as a triangular lattice of spectrin tetramers. This network obstructs lateral diffusion of proteins and provides mechanical reinforcement to the membrane. These effects are treated in a systematic and unified manner in terms of a percolation model. The diffusion coefficient is obtained as a function of the fraction of normal spectrin tetramers for both static and fluctuating barriers. The elasticity of the network is calculated as a function of the fraction of normal spectrin and the ratio of bending to stretching energies. For static barriers, elasticity and lateral diffusion are incompatible: if a network is connected enough to be elastic, it is connected enough to block long-range lateral diffusion. The elasticity and the force required for mechanical breakdown go to zero at the percolation threshold; experimental evidence suggests the existence of a stability threshold at or near the percolation threshold. The model is qualitatively applicable to other cells with membrane skeletons, such as epithelial cells, in which localization of membrane proteins is essential to differentiation.
A Return to Eye-Movement Training? An Evaluation of the Reading Plus Program

The improvement of reading achievement is a major goal for schools in our society. Many schools are exploring the potential of computer-based reading programs to help improve reading achievement. However, many of these programs lack research-based evidence for their effectiveness. The Taylor Associates, Inc. Reading Plus program has been hypothesized to increase visual reading efficiency and, as a result, to also increase reading skill and achievement. In order to evaluate the effectiveness of the Taylor Associates, Inc. Reading Plus and Guided Reading program, pre- and post-test measures of curriculum-based measurement (CBM) of oral reading fluency and reading comprehension collected from a sample of middle school students were analyzed. A total of 87 students participated in the semester long intervention. Gains in scores on CBM oral reading fluency and reading comprehension were compared to normative gains derived from a district-wide norm sample. Significant differences in discrepancy ratios from pre-...
Kinetics of Delignification: A Molecular Approach

A treelike model has been proposed for the structure of lignin. Kinetics of delignification are formulated to account for the cleavage of linkages along the linear primary chains and at the cross-links. Experimental data obtained from isothermal delignification are used to verify this theory. Good agreement has been obtained in calculating the delignification curves. Activation energies are found to be 172 kilojoules per mole of cross-links and 132 kilojoules per mole of aryl ether bonds.
Extending simulation uses of antithetic variables: partially monotone functions, random permutations, and random subsets

We show how to effectively use antithetic variables to evaluate the expected value of (a) functions of independent random variables, when the functions are monotonic in only some of their variables, (b) Schur functions of random permutations, and (c) monotone functions of random subsets.
The thymus: a house dividing

Comment on Gray et al, page [3777][1] The relative radioresistance of thymic epithelium has led to the assumption that this population is static and exhibits little turnover during postnatal life. Recent studies demonstrating significant proliferation by thymic epithelial cells in the postnatal
Nightly analyses of subjective and objective (actigraphy) measures of sleep in fibromyalgia syndrome: what accounts for the discrepancy?

Objectives To evaluate the concordance between the subjective and objective methods of sleep assessment in patients with fibromyalgia syndrome (FMS) and to delineate factors associated with discrepancy between the 2 sleep assessment methods. Methods Seventy-five patients with FMS completed a 7-day home assessment protocol. They wore an actigraphic device at all times. In the morning, they used the electronic diary to record the subjective report of sleep from the previous night and current severity of the FMS-related symptoms. Results On average, the 2 assessment methods yielded a 73 absolute minute difference per night per patient. About half of the nights, sleep duration was underestimated. Approximately 20% of the nights had greater than 2-hour difference between the 2 methods. Factors related to this large discrepancy were (1) objective indicator of restless sleep, (2) subjective report of difficulty falling asleep, and (3) report of fatigue at the time of reporting. FMS-related symptoms were related to subjective report of poor sleep but not to objective sleep data. Discussion Misestimation of sleep seems common in FMS patients, particularly when their sleep quality is poor. Careful considerations for evaluating the severity of patients' sleep complaints are critical in adequate management of sleep disturbance that is commonly reported by FMS patients.
A GABA Transporter Operates Asymmetrically and with Variable Stoichiometry

Membrane currents produced by the expression of a rat GABA transporter (GAT-1) stably transfected into HEK293 cells were characterized with a whole-cell voltage clamp. Three modes of function were identified: ex-gated currents produced by extracellular GABA, in-gated currents produced by intracellular GABA, and uncoupled currents produced in the absence of GABA. The ex-gated current was not the reversal of the in-gated current; moreover, the stoichiometry between GABA and co-ions was not always fixed. Each mode of function required a different set of ions on the two sides of the membrane. We made rapid solution changes and observed an allosteric effect of Na+ that only occurred at the extracellular surface. Thus, the GAT-1 transporter does not behave like a recirculating carrier but may be described as a pore with ion gates at either end that are controlled in part by allosteric sites.
Optimal dichotomization for repeated screening tests

Repeated use of a screening test for ascertaining a characteristic often can improve screening performance. We propose a Bayesian predictive decision-theoretic approach to choosing an optimal dichotomizer for the screening test variable in the repeat-test setting.
High-dynamic-range quantitative phase imaging with spectral domain phase microscopy

Phase microscopy for high-dynamic-range quantitative phase-contrast imaging of a transparent phase object was demonstrated. Using a common path Fourier domain optical coherence tomography system, this technique is capable of displacement measurement with a sensitivity of 34 pm. The limitation of 2pi ambiguity restriction was overcome by the use of a phase retrieval approach performed in spectral domain. Two-dimensional quantitative phase imaging of human neonatal dermal keratinocyte cells was demonstrated to evaluate the performance of the system for cell imaging.
The p23 molecular chaperone and GCN5 acetylase jointly modulate protein-DNA dynamics and open chromatin status.

Cellular processes function through multistep pathways that are reliant on the controlled association and disassociation of sequential protein complexes. While dynamic action is critical to propagate and terminate work, the mechanisms used to disassemble biological structures are not fully understood. Here we show that the p23 molecular chaperone initiates disassembly of protein-DNA complexes and that the GCN5 acetyltransferase prolongs the dissociated state through lysine acetylation. By modulating the DNA-bound state, we found that the conserved and essential joint activities of p23 and GCN5 impacted transcription factor activation potential and response time to an environmental cue. Notably, p23 and GCN5 were required to maintain open chromatin regions along the genome, indicating that dynamic protein behavior is a critical feature of various DNA-associated events. Our data support a model in which p23 and GCN5 regulate diverse multistep pathways by controlling the longevity of protein-DNA complexes.
Antinociceptive activity of buprenorphine and lumiracoxib in the rat orofacial formalin test: a combination analysis study.

Abstract Combination of two or more analgesics is widely used for the treatment of moderate and severe pain syndromes, allowing usage of lower doses of each compound and thereby limiting side effects; there is currently a large interest in investigating the potential advantages of combinations between opioids and non-steroidal inflammatory drugs (NSAIDs), coxibs in particular. The rat orofacial formalin test is a useful pre-clinical model of inflammatory trigeminal pain for evaluating antinociceptive activity of analgesics and their combinations. Injection of formalin in the rat wiskerpad induces a stereotyped response (rubbing), consisting of two distinct phases: a first ‘phasic’ phase and a second ‘tonic’ phase. In this work we tested a partial agonist to μ-opioid receptors, buprenorphine, and a selective cyclo-oxygenase-2 inhibitor, lumiracoxib, each of which given i.p. either alone or in combination. Buprenorphine reduced nociception both in the first and in the second phase, whereas lumiracoxib induced antinociception in the second phase only. The interaction between the two drugs was assessed through isobolographic analysis after combined administration at a fixed dose ratio. Such combination produced a dose-dependent antinociceptive effect in both phases. We observed a statistical difference between the theoretical and the experimental ED50, which indicated synergistic interaction in the second phase. Concerning the first phase, we assumed that the antinociceptive effects were almost completely to be attributed to buprenorphine, since lumiracoxib was ineffective when administered alone. However, we found an unexpected difference between the theoretical and experimental ED50, suggesting synergism in the first phase as well.
[3H] cortisol binding by young and old human liver cytosol proteins in vitro

Abstract 1. 1. Corticosteroid binding proteins of liver cytosol arc similar in rat and human. 2. 2. There is a significant quantitative decrease in the binding proteins with old age.
The Effect of Lifting vs. Lowering on Spinal Loading

In industry, workers perform tasks requiring both lifting and lowering. During concentric lifting, the muscles are shortening as the force is being generated. Conversely, the muscle lengthens while generating force during eccentric lowering. While research on various lifting tasks is extensive, there has been limited research performed to evaluate the lowering tasks. Most of the research that does exist on lowering has investigated muscle activity and trunk strength. None of these studies have investigated spinal loading. The current study estimated the effects of lifting and lowering on spinal loads and predicted moments imposed on the spine. Ten subjects performed both eccentric and concentric lifts under sagittally symmetric conditions. The tasks were performed under isokinetic trunk velocities of 5, 10, 20, 40, and 80 deg/s while holding a box with weights of 9.1, 18.2, and 27.3 kg. Spinal loads and predicted moments in three dimensional space were estimated by an EMG-assisted model which has been adj...
Donor Hearts Not Offered or Rejected for Transplantation – A Lost Opportunity?

Purpose Heart transplantation remains the most effective therapy for end-stage heart failure but is limited by the scarcity of available donors. Even among standard criteria donors, cardiac donor conversion rates are less than 50% suggesting that a number of potentially acceptable hearts are not transplanted. We evaluated a series of donor hearts not placed and assessed their suitability for transplantation. Methods and Materials 33 donor hearts either rejected or not offered for transplantation and tissue donation were procured in an organ procurement organization approved research protocol from 1/2008 to 2/2012. Clinical data from these research donors were reviewed to determine whether hearts were potentially acceptable or unacceptable. To be deemed acceptable, donors had to be less than 55 years of age with a satisfacory functional evaluation (echocardiography, cardiac catheterization) and/or intraoperative assessment by the procuring surgeon. Donors with recent IV drug use were considered unacceptable. Results 16 hearts were considered acceptable and 17 hearts were considered unacceptable. Among donors 50 years of age or younger, 14/18 were considered acceptable. Acceptable cardiac donors were younger (36±3 vs 53±4 years, p Conclusions In this selected cohort, nearly half of the hearts rejected or not offered for donation were potentially suitable for transplantation. These data suggest a significant number of acceptable donor hearts are not transplanted.
Comparing fecundity in parthenogenetic versus sexual populations of the freshwater snail Campeloma limum: is there a two‐fold cost of sex?

. The predominance of sexuality in eukaryotes remains an evolutionary paradox, given the “two-fold cost of sex” also known as the “cost of males.” [Correction added after online publication 29 January 2009: in the preceding sentence, extraneous words were deleted.] As it requires two sexual parents to reproduce and only one parthenogenetic parent, parthenogens should have twice the reproductive rate compared with their sexual counterparts and their genes should spread twice as fast, if all else is equal. Yet, parthenogenesis is relatively rare and considered an evolutionary dead-end, while sexuality is the dominant form of reproduction in multicellular eukaryotes. Many studies have explored short-term benefits of sex that could outweigh its two-fold cost, but few have compared fecundity between closely related sexuals and parthenogens to first verify that “all else is equal” reproductively. We compared six fecundity measures between sexual and parthenogenetic populations of the freshwater snail, Campeloma limum, during a brooding cycle (1 year) across two drainages. Drainages were analyzed separately because of a significant drainage effect. In the Savannah drainage, fecundity was not significantly different between sexuals and parthenogens, even though parthenogens had significantly more empty egg capsules per brood. In the Ogeechee drainage, parthenogens had significantly more egg capsules with multiple embryos and more hatched embryos than sexuals. Taken over 1 year, embryo size was not significantly different between parthenogens and sexuals in either drainage. Given these results and the close proximity of sexual and parthenogenetic populations, it is perplexing why parthenogenetic populations have not completely replaced sexual populations in C. limum.
Sulfate reduction and the nature of organic matter in estuarine sediments

Abstract The reduction of sulfate by sulfate reducing bacteria in the anoxic zone is an extremely important process during early diagenesis of marine sediments. Our data from Great Bay, NH reinforce the proposal that the rate of sulfate reduction is directly proportional to the reactivity of the organic matter or the amount of readily metabolizable organic matter present in the sediment and, hence, the source of the organic material in the anoxic zone. It appears that organic matter rich in marine organic remains is more easily degraded in the anoxic zone and that sulfate reduction rates can vary considerably in an estuarine system where many types of organic material may be deposited.
Vibration damping in Ni-Mn-Ga composites

Ferromagentic shape memory alloy composites exhibit good qualities as vibration absorbers. Loss ratios in excess of 25% have been measured in polymer samples containing 20 vol% Ni-Mn-Ga. The ability to dissipate large amounts of energy is due to the same mechanism that is also responsible for the large strains observed in single crystals used as actuators, namely twin-boundary motion. The loss ratios of the FSMA-loaded composites are compared to those for pure polymer samples and polymer loaded with inert filler. The effects of the pre-processing of the filler material on its performance are also shown.
Multisubunit RNA Polymerases IV and V: Purveyors of Non-Coding RNA for Plant Gene Silencing

In all eukaryotes, nuclear DNA-dependent RNA polymerases I, II and III synthesize the myriad RNAs that are essential for life. Remarkably, plants have evolved two additional multisubunit RNA polymerases, RNA polymerases IV and V, which orchestrate non-coding RNA-mediated gene silencing processes affecting development, transposon taming, antiviral defence and allelic crosstalk. Biochemical details concerning the templates and products of RNA polymerases IV and V are lacking. However, their subunit compositions reveal that they evolved as specialized forms of RNA polymerase II, which provides the unique opportunity to study the functional diversification of a eukaryotic RNA polymerase family.
A NEW AND SIMPLE CHAOS TOY

We present two new, and perhaps the simplest yet, mechanical chaos demonstrations. They are both designed based on a recipe of competing nonlinear oscillations. One of these devices is simple enough that using the provided description, it can be built using a bicycle wheel, a piece of wood routed with an elliptical track, and a ball bearing. We provide a thorough Lagrangian mechanics based derivation of equations of motion, and a proof of chaos based on showing the existence of an embedded Smale horseshoe using Melnikov's method. We conclude with discussion of a future application.
The determinants of consumers’ online shopping cart abandonment

Despite placing items in virtual shopping carts, online shoppers frequently abandon them —an issue that perplexes online retailers and has yet to be explained by scholars. Here, we identify key drivers to online cart abandonment and suggest cognitive and behavioral reasons for this non-buyer behavior. We show that the factors influencing consumer online search, consideration, and evaluation play a larger role in cart abandonment than factors at the purchase decision stage. In particular, many customers use online carts for entertainment or as a shopping research and organizational tool, which may induce them to buy at a later session or via another channel. Our framework extends theories of online buyer and non-buyer behavior while revealing new inhibitors to buying in the Internet era. The findings offer scholars a broad explanation of consumer motivations for cart abandonment. For retailers, the authors provide suggestions to improve purchase conversion rates and multi-channel management.
The carbon dioxide hydration activity of brush-border carbonic anhydrase from the dog kidney

Abstract The steady-state kinetic parameters for the hydration of CO2 catalyzed by membrane-bound carbonic anhydrase from the renal brush-border of the dog are compared with the same parameters for water-soluble bovine erythrocyte carbonic anhydrase. For the membrane-bound enzyme, the turnover number kcat is 6.5 × 105 s−1 and the Michaelis constant is 7.5 m m for CO2 hydration at pH 7.4 and 25 °C. The corresponding constants for bovine carbonic anhydrase under these conditions are 6.3 × 105 s−1 and 15 m m ( Y. Pocker and D.W. Bjorkquist (1977) Biochemistry16, 5698–5707). The rate constant for the transfer of a proton between carbonic anhydrase and buffer was determined from the dependence of the catalytic rate on the concentration of the buffers imidazole and N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (Hepes); the value of 2 × 108 m −1s−1 describes this constant for both forms of carbonic anhydrase at pH 7.4. Furthermore, the pH dependence of the initial velocity of hydration of CO2 in the range of pH 6.5 to 8.0 is identical for the membrane-bound and soluble enzyme at low buffer concentration (1–2 m m imidazole). We conclude that the membrane plays no detectable role in affecting the CO2 hydration activity and that the active site of the renal, membrane-bound carbonic anhydrase is exposed to the aqueous phase.