cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 16419: A Comparative Analysis of Prasugrel versus Ticagrelor on Rates of High On-Treatment Platelet Reactivity Following Switch From Clopidogrel Therapy

Background: Clopidogrel is characterized by non-uniform pharmacodynamic (PD) effects leading to considerable rates of high on-treatment platelet reactivity (HPR), a marker of increased atherothrombotic risk. Prasugrel and ticagrelor have greater potency and more uniform PD effects compared with clopidogrel. The effects of switching from clopidogrel to prasugrel or ticagrelor and how this impacts HPR rates has been poorly explored. Methods: This was a prospective, randomized PD study conducted in patients with coronary artery disease on maintenance aspirin (81mg/qd) and clopidogrel (75mg/qd) therapy. Patients were randomized to switch to prasugrel (60mg loading dose/10mg maintenance dose qd) or ticagrelor (180mg loading dose/90mg maintenance dose bid) for 1 week. PD assessments were performed at 5 time points: before (while on clopidogrel) and 30 min, 2 hrs, 24 hrs and 1 week after switch. HPR was defined by a platelet reactivity index (PRI) > 50% assessed by VASP and platelet reaction unit (PRU) > 208 assessed by VerifyNow P2Y12 (VN). Results: A total of 110 patients were studied. HPR on clopidogrel therapy as defined by VASP-PRI was observed in 67.3% of the overall population. HPR rates were similarly distributed among patients subsequently randomized to prasugrel vs ticagrelor (69.8% vs 64.7%, p=0.57). After switching to prasugrel or ticagrelor, HPR rates significantly reduced as early as 30 min and continued to decrease consistently in both groups over the study time period. At 1 week, HPR was found in 13.7% and 15.6% of patients randomized to prasugrel and ticagrelor, respectively (p=0.80) (Figure). Parallel findings were observed when assessing HPR rates defined by VN-PRU (Figure). Conclusions: Switching from clopidogrel to a more potent P2Y 12 inhibiting agent significantly reduces HPR rates. Reduction in HPR rates occur to a similar extent between prasugrel and ticagrelor in both the acute and maintenance phases of therapy.
Spatially sparse spatio-spectral filters for feature extraction in BMI applications

The common spatio-spectral pattern method is an extension of the traditional common spatial pattern technique that combines spectral filtering with the original spatial filtering. All recording channels are combined when extracting the variance as input features for a brain machine interface. This results in overfitting and robustness problems of the constructed system in presence of high number of channels. Here, we construct spatially sparse common spatio-spectral pattern method in which only a subset of all available channels is linearly combined when extracting the features. We utilized a modified version of the recently introduced recursive weight elimination technique to select a subset of electrodes for spatio-spectral projections. We evaluate the performance of the proposed method to distinguish between the movements of the first three fingers of the hand using electrocorticogram signals of the brain computer interfaces competition 2005. We observed that spatially sparse spatio-spectral filter outperforms both original common spatial pattern and non-sparse spatio-spectral filter and results in improved generalization in classification.
Editorial Comment—Epistasis Is Coming Are We Ready?

For physicians and patients, the central challenge of human genetics is unraveling the genetic architecture of human diseases. Depending on the disease, this architecture can range from simple to complex. In the so-called mendelian diseases, 1 mutation in a single gene is sufficient to cause disease, whereas more complex diseases may involve changes in single genes, multiple genes, or even combinations of alleles within the same gene. The payoff for successful disease-gene discovery is likely to be enormous, leading to novel biologic discoveries and innovative interventions that can alleviate human suffering. The search so far, however, has been slower than we would all like. The nagging problem is that for most common diseases, the culprit gene variants contribute only a small proportion of disease risk. Successful studies must therefore detect relatively weak associations, and finding weak associations requires very large samples of patients. Epistasis, broadly defined, is the interaction between alleles at different loci, or positions, in the genome. Most simply, a variant at 1 locus can prevent a variant at another locus from manifesting its effect.1,2 These combinations of variants may be in different genes, or they may be within the same gene, eg, within the regulatory and coding regions. Ultimately, epistatic interaction is synergistic, with an effect that differs from the simple sum …
Increasing capture efficiency of pallid sturgeon Scaphirhynchus albus (Forbes and Richardson, 1905) and the reliability of catch rate estimates

Summary This study evaluated the effects of environmental parameters on the probability of capturing endangered pallid sturgeon (Scaphirhynchus albus) using trotlines in the lower Mississippi River. Pallid sturgeon were sampled by trotlines year round from 2008 to 2011. A logistic regression model indicated water temperature (T; P < 0.01) and depth (D; P = 0.03) had significant effects on capture probability (Y = −1.75 − 0.06T + 0.10D). Habitat type, surface current velocity, river stage, stage change and non-sturgeon bycatch were not significant predictors (P = 0.26–0.63). Although pallid sturgeon were caught throughout the year, the model predicted that sampling should focus on times when the water temperature is less than 12°C and in deeper water to maximize capture probability; these water temperature conditions commonly occur during November to March in the lower Mississippi River. Further, the significant effect of water temperature which varies widely over time, as well as water depth indicate that any efforts to use the catch rate to infer population trends will require the consideration of temperature and depth in standardized sampling efforts or adjustment of estimates.
Resolving Quasi Logical Forms

The paper describes intermediate and resolved logical form representations of sentences involving referring expressions and a reference resolution process for mapping between these representations. The intermediate representation, Quasi Logical Form (or QLF), may contain unresolved terms corresponding to anaphoric noun phrases covering bound variable anaphora, reflexives, and definite descripitions. Implict relations arising in constructs such as compound nominals appear in QLF as unresolved formulae. The QLF representation is also neutral with respect to ambiguities corresponding to quantifier scope and the collective/distributive distinction, the latter being treated as quantifier resolution. Reference candidates are proposed according to an ordered set of "reference resolution rules" producing possible resolved logical forms to which linguistic and pragmatic constraints are then applied.
State of the Multiple Imputation Software

Owing to its practicality as well as strong inferential properties, multiple imputation has been increasingly popular in the analysis of incomplete data. Methods that are not only computationally elegant but also applicable in wide spectrum of statistical incomplete data problems have also been increasingly implemented in a numerous computing environments. Unfortunately, however, the speed of this development has not been replicated in reaching to "sophisticated" users. While the researchers have been quite successful in developing the underlying software, documentation in a style that would be most reachable to the greater scientific society has been lacking. The main goal of this special volume is to close this gap by articles that illustrate these software developments. Here I provide a brief history of multiple imputation and relevant software and highlight the contents of the contributions. Potential directions for the future of the software development is also provided.
Characterization of Polymer and Solute Bound Water by Pulsed NMR

Pulsed NMR signals from water in combination with two polymers and two solutes, individually and in mixtures, was measured over aw range 0.75–0.95. Both spin-lattice (T1) and spin-spin (T2) relaxation curves showed negligible slopes for water with starch and casein (polymer water) and large for water with sucrose and salt (solute water). Mixtures of polymer and solute waters showed intermediate slopes. Dilution of a sucrose solution gave T1 and T2 responses approaching that of pure water. T2 from NaCl indicated less and from sucrose more water structure than pure water. NMR data coincided with sorption isotherms. It was concluded that polymer and solute waters show different NMR responses and can coexist in a food.
5.4.3 A Case Study in Modeling Company Policy Documents as a Source of Requirments

This paper describes an approach that was developed to produce structured models that graphically reflect the requirements contained within a text document. The document used in this research is a draft policy document governing business in a research and development environment. In this paper, we present a basic understanding of why this approach is needed, the techniques developed, lessons learned during modeling and analysis, and recommendations for future investigation. The modeling method applied on the policy document was developed as an extension to entity relationship (ER) diagrams, which built in some structural information typically associated with object oriented techniques. This approach afforded some structure as an analysis tool, while remaining flexible enough to be used with the text document. It provided a visual representation that allowed further analysis and layering of the model to be done.
Droplet Freezing by Surface Nucleation

Abstract Droplet freezing by surface nucleation has been observed during the course of studies of ice nucleation in our laboratories. A constant rate of cooling apparatus and a specially constructed cold chamber were used for this study. Silver iodide particles sprinkled on supercooled, millimeter-size water drops are effective in freezing the drops at −5C. Particles of naturally occurring silicates were found to be effective in the range −7 to −10C. Thus, the ice nucleating ability of such dry particles is much greater by the surface contact mechanism than when particles are embedded in the drops. The importance of the surface nucleation mechanism in forming solid hydrometeors in cumulus clouds is assessed.
Modified Langmuir isotherm for a two-domain adsorbate: derivation and application to antifreeze proteins.

Many organisms are exposed to subzero temperatures in nature and can survive these temperatures by the effect of antifreeze proteins (AFPs), which inhibit ice crystal growth and change the morphology of ice crystals. Although the effects of these proteins, such as recrystallization inhibition, ice growth inhibition, and crystal habit changes, are known, a conclusive description of the protein–ice crystal interaction including interaction energy, surface coverage, and lifetime of adsorbate has been elusive. In this study, we determine the binding equilibrium constant for a type III fish antifreeze protein and the relationship between thermal hysteresis and surface coverage for this protein. This is possible using experimental data from a two-domain antifreeze protein and its related single domain protein. The classical Langmuir isotherm is used to describe the equilibrium exchange of the single domain type III AFP molecules at the ice crystal surface, while a modification of the Langmuir isotherm is derived to describe the adsorption of the two-domain AFP. Because the protein adsorption is governed by different isotherm relationships, there are two independent data sets allowing the determination of the two unknowns of surface coverage and binding energy. The data yield an equilibrium binding constant of 1.9 mM−1 for the type III AFP–ice interaction. The analysis results in a relationship between surface coverage and thermal hysteresis, as well as kinetic equations of the adsorption of the proteins onto the ice surface.
Controlled excitations of the Belousov-Zhabotinsky reaction: Experimental procedures.

The purpose of this research was to explore the unstirred, ferroin-catalyzed Belousov−Zhabotinsky (BZ) reaction as an experimental model for the response of excitable media to small perturbations (slightly larger than the threshold for excitations). Following Showalter et al. (Showalter, K.; Noyes, R. M.; Turner, H. J. Am. Chem. Soc. 1979, 101, 7463−69), we used a positively biased silver electrode to release silver ions into a BZ reaction mixture, removing bromide ions and causing an excitation if sufficient bromide was removed. We found (1) a scaling region in which the delay before activation increased linearly as the size of the perturbation decreased, qualitatively consistent with but not fully explained by the Oregonator of Field et al. (Field, R. J.; Koros, E.; Noyes, R. M. J. Am. Chem. Soc. 1972, 94, 8649−64); (2) evidence for a 10 s oligomerization time scale; and (3) that activations were always delayed until after the end of a pulse of current, with the delay essentially constant for sufficient...
Cumulants: A powerful tool in signal processing

The impulse response of a linear, time-invariant system is related in a simple closed-form solution to the output cumulants, when the input is assumed to be non-Gaussian and independent. This expression permits the use of one-dimensional processing of the output cumulants for identification of non-minimum-phase systems, and opens new directions in other signal processing applications.
Brand Library & Art Center, Glendale Public Library, Glendale, California

The Brand Library & Art Center is nestled in the foothills of California's Verdugo Mountains. The Glendale landmark was built in 1904 and opened as a library and art center in 1956. It is currently...
Genetic Testing for Developmental Delay: Keep Searching for an Answer

A 6-year-old girl of Irish, English, and French ancestry was referred to a pediatric neurologist for evaluation of developmental delay. She presented with expressive language delay with disarticulation. She did not speak in phrases until age 3, and formal testing revealed a language equivalent of 3 years 4 months when she was 5 years 6 months old (Clinical Evaluation of Language Fundamentals–Preschool) and an IQ of 64 (Wechsler Preschool & Primary Scale of Intelligence). Gross motor development was also delayed; she first walked at age 17–18 months. She never had any developmental regression. There was a family history of learning disability in her mother and a maternal uncle, and a maternal first cousin once removed was born with myelomeningocele. She was delivered at term after an uncomplicated pregnancy that was conceived by in vitro fertilization. At 10 days of age, she was diagnosed with atrioventricular (A-V)1 canal malformation and coarctation of the aorta. She underwent surgical repair of her coarctation at age 10 days and of her A-V canal defect at age 4 months. She had a bifid uvula, a finding often associated with presence of a submucous cleft palate. Modified barium swallow demonstrated a poorly coordinated swallow reflex leading to poor feeding and aspiration. As an infant, she had true vocal cord paralysis, believed to be a complication from intubation. She had gastroesophageal reflux disease, treated with ranitidine (Zantac), and was diagnosed with mild vesicoureteral reflux after a urinary tract infection at age 7 months. She has not had any episodes suggesting seizures or any features of autism other than language delay. Notable physical exam features include widely spaced eyes (hypertelorism), bulbous nasal tip, high arched palate, and fifth finger clinodactyly. Her neurologist ordered an MRI that showed mild thinning of the corpus callosum with prominence of the …
Increased eosinophil infiltration and degranulation in colonic tissue from patients with collagenous colitis

Increased eosinophil infiltration and degranulation in colonic tissue from patients with collagenous colitis
Skeletal muscle vasculitis exclusive of inflammatory myopathic conditions: A clinicopathologic study of 40 patients

Vasculitis is an infrequently encountered pathology in skeletal muscle biopsy specimens, the diagnosis of which has significant therapeutic implications. This study retrospectively reviewed the clinicopathologic features of 40 patients with vasculitis (infiltration of vessel walls by inflammatory cells) diagnosed via skeletal muscle biopsy during a 27-year period of time. Cases of vasculitis associated with inflammatory myopathic conditions, such as polymyositis or dermatomyositis, were excluded from study. Forty patients, including 21 women and 19 men ranging in age from 19 to 83 years (mean of 52 years), formed the study group. The most common clinical presentations included muscle pain (n = 22, 55%), paresthesias (n = 16, 40%), and weight loss (n = 15, 38%). Westergren erythrocyte sedimentation rate was known in 31 patients and ranged from 12 to >150 mm/h (mean, 61 mm/h). Necrotizing vasculitis was identified in 35 patients (88%). The vasculitic process involved multiple vessels in 30 cases (75%). Vessel wall scarring and/or fibrosis were identified in 11 patients (28%), thrombi in 3 patients (8%), eosinophils in 2 patients (5%), and granulomas in 1 patient (3%). Neurogenic changes were observed in the majority of biopsy specimens as follows: angular atrophic esterase-positive muscle fibers (n = 35, 88%), grouped atrophy (n = 14, 35%), fiber type grouping (n = 17, 43%), and target fibers (n = 6, 15%). Other commonly identified pathologies included scattered degenerating muscle fibers (n = 15, 38%), regenerating muscle fibers (n = 17, 43%), and type II muscle fiber atrophy (n = 10, 25%). Thirty-three patients also underwent sural nerve biopsy. Vasculitis was identified in the nerve in 26 of 33 of these patients (79%). Peripheral nerve vasculitis was classified as necrotizing in 15 cases (57.7%) and as nonnecrotizing in 11 cases (42.5%). Seventeen of 33 patients (52%) with known follow-up showed clinical improvement with steroid/immunosuppressive therapy. The following 2 conclusions were made: the majority of vasculitis cases arising outside the setting of inflammatory myopathy in skeletal muscle are necrotizing, and the predominant muscle pathology in the setting of vasculitis is neurogenic atrophy, likely caused by concomitant involvement of the peripheral nervous system.
Surgical Treatment of Achalasia: Results with Esophagomyotomy and Belsey Repair

To address the controversy regarding the choice of operation for achalasia, the cases of 57 patients having operation, 38 for the first time (Group 1) and 19 with a previous procedure (Group 2), were reviewed. Surgical emphasis was on hiatal dissection to maximize exposure and use of the Belsey fundoplication to achieve cardiac competence without obstruction. Operative mortality was 1 (1.8%) of 57 patients. In group 1, 21 of the 38 had prior pneumatic dilations. All were treated with esophagomyotomy and a Belsey fundoplication. Clinical results are excellent or good in 30 (88%) of the 34 patients for whom follow-up is available, and are similar in patients with and without prior dilation. Lower esophageal sphincter (LES) pressure decreased from 22.3 to 7.7 mm Hg (p less than 0.001), and pH testing shows no reflux in any of 13 patients. In Group 2, previous operations were esophagomyotomy in 13, esophagomyotomy plus a Nissen fundoplication in 3, and a Nissen fundoplication only in 3. The initial operation failed because of inadequate myotomy in 6 patients, an obstructive Nissen fundoplication in 6, and reflux esophagitis in 7. In these 7 patients, acid reflux testing documented reflux due to cardiac incompetence and delayed clearance. Reoperations included takedown of a Nissen fundoplication in 6, esophagomyotomy and Belsey procedure in 15, Belsey procedure in 1, and resection plus colon interposition in 2. Clinical results are excellent or good in 12 (75%) of the patients with follow-up. These conclusions can be drawn. (1) Esophagomyotomy and Belsey fundoplication lowers LES pressure and provides good results with low risk, even after pneumatic dilation.(ABSTRACT TRUNCATED AT 250 WORDS)
Planar imaging of soot formation in turbulent ethylene diffusion flames: Fluctuations and integral scales

Abstract Planar imaging of soot in a series of atomspheric ethylene diffusion flames ranging from laminar to turbulent is reported. From single shot images of 532 nm light scattered at right angles by soot, the fluctuations, intermittency, and integral scales of soot are determined. The soot in turbulent (Re = 5500) ethylene flames occurs in highly convolved regions, suggestive of roll-up vortices. The regions are thin and elongated, lying somewhat perferrentially in the axial direction. The soot integral scales are smaller than velocity integral scales in corresponding cold jet flows. The soot in the late oxidative stages of the flame occurs in a few, highly intermittent, high concentration regions. The regions of low concentration have been oxidized away. This suggests that the soot emissions of turbulent flame are determined by (1) the regions of highest soot concentration, which may avoid oxidation by radiative cooling, as suggested by Kent, or (2) a few regions of high soot concentration that, by stochastic chance, fail to mix adequately with hot oxidizing gases in the transit time to the cooler gases above the flame. At given axial distances from the flame, there is little radial variation in the integral scale and strength of scattering within soot-containing eddies, but the number density of soot eddies does vary. This suggests that the soot chemistry is fast only within selective eddies, presumably of high temperature, and that the radial profiles are determined by mixing.
Evaluating habitat effects on population status: influence of habitat restoration on spring‐run Chinook salmon

SUMMARY 1. A key element of conservation planning is the extremely challenging task of estimating the likely effect of restoration actions on population status. To compare the relative benefits of typical habitat restoration actions on Pacific salmon (Oncorhynchus spp.), we modelled the response of an endangered Columbia River Chinook salmon (O. tshawytscha) population to changes in habitat characteristics either targeted for restoration or with the potential to be degraded. 2. We applied a spatially explicit, multiple life stage, Beverton-Holt model to evaluate how a set of habitat variables with an empirical influence on spring-run Chinook salmon survivorship influenced fish population abundance, productivity, spatial structure and diversity. Using habitat condition scenarios – historical conditions and future conditions with restoration, no restoration, and degradation – we asked the following questions: (i) how is population status affected by alternative scenarios of habitat change, (ii) which individual habitat characteristics have the potential to substantially influence population status and (iii) which life stages have the largest impact on population status? 3. The difference in population abundance and productivities resulting from changes in modelled habitat variables from the ‘historical’ to ‘current’ scenarios suggests that there is substantial potential for improving population status. Planned restoration actions directed toward modelled variables, however, produced only modest improvements. 4. The model predicted that population status could be improved by additional restoration efforts directed toward further reductions in the percentage of fine sediments in the streambed, a factor that has a large influence on egg survival. Actions reducing fines were predicted to be especially effective outside the national forest that covers most of the basin. Scenarios that increased capacity by opening access to habitat in good condition also had a positive but smaller effect on spawner numbers. 5. Degradation in habitat quality, particularly in percent fine sediments, within stream reaches located in the national forest had great potential to further reduce this population’s viability. This finding supports current forest planning efforts to minimise road density and clear-cut harvests and to return forest stand structure in dry regions to the historical condition that promoted frequent low-intensity fires rather than catastrophic standreplacing fires, as these landscape factors have been shown to influence percent fine sediment in streams.
Trilingualism in the Barrio: Mayan Indians in Los Angeles

RESUMOTrilingvismo en la "barrio": Majaaj indianoj en LosangelesoMajaaj enmigrintoj al Losangeleso, Kalifornio, daǔre submetigas al la procedo de hispanigo, kiu komencigis en Gvatemalo. Ili pli multe uzas la hispanan lingvon ol ili tion faris en Gvatemalo kaj ili plue lernas ĝin en la latina komunumo kie ili loĝas. Krome, tiu plejparte dulingva (majaa kaj hispana) grupo trovigas en komenca stadio de trilingviĝo dum kelkaj, precipe la viroj, infanoj kaj delongaj enmigrintoj, ekakiras la anglan. La virinoj, malpli klerigitaj ol la viroj, uzas la indigenan lingvon pli ofte kaj estas malpli alfabetigitaj kaj malpli kapablaj en hispana kaj angla ol la viroj, eĉ kiam oni tenas en konsidero la nombron de jaroj de klerigo. La estonteco de la majaa en Losangeleso farigas duba car la infanoj rezistas lerni gin kaj estas multe pli malfermaj al lernado de la hispana kaj angla. La nuna stadio de komenca, nestabila trilingvismo eventuale kondukos al pli-malpli stabila hispana-angla dulingvismo.SUMARIOEl trilinguismo en el barrio: Los indios Mayas en los AngelesLos inmigrantes Mayas, de los Angeles (California) todavia continuan el proceso de Hispanizacion que empezaron en Guatemala; como resultado, hablan mas Espanol en los Angeles que en su pais nativo, y al mismo tiempo estan aprendiendo mas Espanol en la comunidad latina donde viven.La comunidad latina donde predominantemente hablan Maya y Espanol se esta viviendo trilingue porque ya todos empiezan a aprender el Ingles (especialmente los ninos, los hombres y los residentes con mas tiempo). Las mujeres, que tienen una educa-cion menor que la de los hombres, usan su idioma nativo mas y estân menos instruidas en Espafiol e Ingles, aun despues de varios anos de eseuela.El futuro de los Mayas en los Angeles es dudoso porque los ninos se resisten a aprender el idioma Maya, mostrando una mejor disposition para el Espanol y el Ingles. Por lo tanto, el incipiente e inseguro nivel trilingue pude conducir a un nivel bilingue (Espanol-Ingles) mas o menos estable.
Plasma BDNF levels associate with Pittsburgh Compound B binding in the brain

Abstract Background Brain-derived neurotrophic factor (BDNF) plays an important role in Alzheimer's disease (AD) and other neurodegenerative disorders. BDNF function is adversely affected by amyloid beta in AD. BDNF levels in brain and peripheral tissues are lower in patients with AD and mild cognitive impairment (MCI) than in controls. Here we examined the association between plasma levels of BDNF and amyloid deposition in the brain measured with Pittsburgh Compound B (PiB). Method Our data set consisted of 18 AD, 56 MCI, and 3 normal control Alzheimer's Disease Neuroimaging Initiative-1 (ADNI1) subjects with available [ 11 C] PiB and peripheral blood protein data. Magnetic resonance imaging (MRI)-coregistered positron emission tomography data were smoothed with a 15 mm kernel and mapped onto three-dimensional (3D) hemispheric models using the warping deformations computed in cortical pattern matching of the associated MRI scans. We applied linear regression to examine in 3D the associations between BDNF and PiB standard uptake value ratio, while adjusting for age and sex. We used permutation statistics thresholded at P Results Plasma BDNF levels showed significant negative associations with left greater than right amyloid burden in the lateral temporal, inferior parietal, inferior frontal, anterior and posterior cingulate, and orbitofrontal regions (left P corrected = .03). Conclusions As hypothesized, lower plasma levels of BDNF were significantly associated with widespread brain amyloidosis.
Temporal and spatial occurrence of deep non‐volcanic tremor: From Washington to northern California

[1] Regional network data reveal deep non-volcanic tremor occurs in five independent sections along the U.S. section of the Cascadia subduction zone with different recurrence intervals. Sizeable tremor episodes occur during periods with no measurable geodetic deformation as well as coincident with episodic slow slip events, and the displacement amplitudes of the tremor with and without geodetic deformation are similar. The tremor depths cover a wide range that does not coincide directly with the subducting slab interface. The tremor can migrate bi-directionally from the point of initiation, and more than one spatially distinct tremor source can be active at a given time. These results indicate that the tremor is not directly related to the slow slip event. Instead we suggest that the tremor is related to the presence and movement of fluids at depth, which can explain the locations and episodic occurrence as well as the seismic signal characteristics themselves; namely, the limited frequency content, small size, emergent onsets, and prolonged durations with and without geodetic deformation.
Deactivation of a composite automobile catalyst pellet: II. Bimolecular Langmuir reaction

Abstract In this work, the deactivation of a composite catalyst pellet is analyzed for reaction and deactivation conditions similar to those found in automobile catalytic converters. The composite catalyst is made of two layers; the inner layer supports the active metal in a high-area support, whereas the outer layer consists of an inert support that protects the active metal from poisons that deactivate the catalyst. The reaction kinetics used is a bimolecular Langmuir kinetics characteristic of CO oxidation on Pt Al 2 O 3 catalysts, and it is assumed that the catalyst operates under diffusion-controlled conditions. It is also assumed that the catalyst deactivates following a pore mouth-poisoning mechanism which is characteristic of Pb or P poisoning of automobile catalysts. The results obtained show that using a composite catalyst one obtains an enhancement of the activity when operating in the region of high reactant concentration. However, at low reactant concentration, the kinetics becomes first order and only the catalyst lifetime can be improved. The results presented here further support previous findings for the first-order reaction indicating that both long-term activity and catalyst lifetime can be improved by using a composite catalyst.
Sparsest cuts and bottlenecks in graphs

Abstract The problem of determining a sparsest cut in a graph is characterized and its computation shown to be NP-hard. A class of sparsest cuts, termed bottlenecks, is characterized by a dual relation to a particular polynomial time computable multicommodity flow problem. Efficient computational techniques for determining bottlenecks in a broad class of instances are presented.
D/H fractionation in the H2–H2O system at supercritical water conditions: Compositional and hydrogen bonding effects

Abstract A series of experiments has been conducted in the H 2 –D 2 –D 2 O–H 2 O–Ti–TiO 2 system at temperatures ranging from 300 to 800 °C and pressures between ∼0.3 and 1.3 GPa in a hydrothermal diamond anvil cell, utilizing Raman spectroscopy as a quantitative tool to explore the relative distribution of hydrogen and deuterium isotopologues of the H 2 and H 2 O in supercritical fluids. In detail, H 2 O–D 2 O solutions (1:1) were reacted with Ti metal (3–9 h) in the diamond cell, leading to formation of H 2 , D 2 , HD, and HDO species through Ti oxidation and H–D isotope exchange reactions. Experimental results obtained in situ and at ambient conditions on quenched samples indicate significant differences from the theoretical estimates of the equilibrium thermodynamic properties of the H–D exchange reactions. In fact, the estimated enthalpy for the H 2(aq) –D 2(aq) disproportionation reaction (Δ H rxn ) is about −3.4 kcal/mol, which differs greatly from the +0.16 kcal/mol predicted for the exchange reaction in the gas phase by statistical mechanics models. The exothermic behavior of the exchange reaction implies enhanced stability of H 2 and D 2 relative to HD. Accordingly, the significant energy difference of the internal H 2(aq) –D 2(aq) –HD (aq) equilibrium translates to strong differences of the fractionation effects between the H 2 O–H 2 and D 2 O–D 2 isotope exchange relationships. The D/H fractionation factors between H 2 O–H 2(aq) and D 2 O–D 2(aq) differ by 365‰ in the 600–800 °C temperature range, and are indicative of the greater effect of D 2 O contribution to the δD isotopic composition of supercritical fluids. The negative Δ H rxn values for the H 2(aq) –D 2(aq) –HD (aq) equilibrium and the apparent decrease of the equilibrium constant with increasing temperature might be because of differences of the Henry’s law constant between the H- and D-bearing species dissolved in supercritical aqueous solutions. Such effects may be attributed to the stronger hydrogen bonding in the O–H⋯O relative to the O–D⋯O environment. This difference allows enhanced gas solubility in the denser and more polar H 2 O clusters, and thus, affects the D/H exchange between the H 2 –D 2 volatiles and the coexisting H 2 O–D 2 O mixtures. The proposed role of temperature in promoting differences in the density and polarity of hydrogen-bonded OHO and ODO molecules may be explained with isotope-specific molar volume effects similar to those suggested to account for the hydrogen isotope fractionation between H 2 O and hydroxide mineral phases (e.g. brucite) across large pressure intervals.
The in vitro metabolism of azinphosmethyl by mouse liver

Abstract The in vitro metabolism of methoxy- 14 C- or 32 P-azinphosmethyl by subcellular fractions from mouse liver was studied. The major degradative activity was associated with the microsomal and soluble fractions. Since the microsomal activity required NADPH and was inhibited by carbon monoxide, it is reasonable to assume that the mixed function oxidases were involved. The microsomal system catalyzed the dearylation reaction resulting in the formation of dimethyl phosphorothioic acid and dimethyl phosphoric acid. The system was also responsible for the oxidative desulfuration of azinphosmethyl resulting in the formation of azinphosmethyl oxygen analog. The degradative activity of the soluble fraction was lost upon dialysis but was restored by the addition of glutathione. It was strongly inhibited by methyl iodide suggesting the involvement of glutathione alkyl transferase. The enzyme catalyzed the conjugation reaction of azinphosmethyl with glutathione and the only products found were S -methyl glutathione and desmethyl szinphosmethyl. No evidence of aryl transferase activity was obtained with this compound. The enzyme, however, showed little activity against the oxygen analog of azinphosmethyl.
Heterogeneous Domain Decomposition for Multi-Scale Problems

The objective of this work is to develop numerical tools useful for the understanding of fundamental phenomena in Blood Flow, including some biochemistry and cellular dynamics. An open problem that may benefit from multi-scale numerical tools is for example the understanding of the relation ship between inflammation and cholesterol plaque. The corresponding topics we address in this paper are (1) Heterogeneous Domain Decomposition for Multi-Scale Problem (2) Fluid-Structure Interaction in the Boundary Layer and (3) Immersed Boundary Method for the dynamic of cells (ref. C.Peskin et Al). In this present paper we concentrate on (1) and give preliminary results on (2) and (3) in the framework of heterogeneous domain decomposition.
Clinical risk stratification for gastrointestinal hemorrhage: still no consensus

A lack of consensus exists in the pre-endoscopic risk stratification of patients with upper or lower gastrointestinal hemorrhage. The work by Das and colleagues in the previous issue of Critical Care serves to externally validate the BLEED criteria. Their results suggest that hemodynamically stable patients without evidence of ongoing bleeding or unstable comorbidities may be at lower risk for hospital complications. While their results reinforce previous studies, further investigation is needed before comprehensive practice guidelines can be established.
Genetic elimination of the binding motif on fibrinogen for the S. aureus virulence factor ClfA improves host survival in septicemia.

Fibrinogen can support host antimicrobial containment/clearance mechanisms, yet selected pathogens appear to benefit from host procoagulants to drive bacterial virulence. Here, we explored the hypothesis that host fibrin(ogen), on balance, supports Staphylococcus aureus infection in the context of septicemia. Survival studies following intravenous infection in control and fibrinogen-deficient mice established the overall utility of host fibrin(ogen) to S. aureus virulence. Complementary studies in mice expressing mutant forms of fibrinogen-retaining clotting function, but lacking either the bacterial ClfA (FibγΔ5) binding motif or the host leukocyte integrin receptor αMβ2 (Fibγ390–396A) binding motif, revealed the preeminent importance of the bacterial ClfA–fibrin(ogen) interaction in determining host survival. Studies of mice lacking platelets or the platelet integrin receptor subunit αIIb established that the survival benefits observed in FibγΔ5 mice were largely independent of platelet αIIbβ3–mediated engagement of fibrinogen. FibγΔ5 mice exhibited reduced bacterial burdens in the hearts and kidneys, a blunted host proinflammatory cytokine response, diminished microscopic tissue damage, and significantly diminished plasma markers of cardiac and other organ damage. These findings indicate that host fibrin(ogen) and bacterial ClfA are dual determinants of virulence and that therapeutic interventions at the level of fibrinogen could be advantageous in S. aureus septicemia.
Feasibility of seawater desalination to solve water shortage problems of the Salina Cruz (PEMEX) Refinery

Abstract As a part of Mexico's Pacific Coastline Project, the Salina Cruz Refinery with an actual capacity of 165000 bbld. is beeing expanded to 330000 bbld (Crude oil). The local water shortage problem has led to consider Seawater Desalination as the source of fresh water to the refinery and other uses. History, information, process selection and design criterion are given for 15,000 cumd, modular desalination units. Special emphasis is made on national fabrication vs. importation, as an economical alternative for third world countries in need of technology.
Poly(ADP-ribosyl)ation basally activated by DNA strand breaks reflects glutamate–nitric oxide neurotransmission

Poly(ADP-ribose) polymerase (PARP) transfers ADP ribose groups from NAD+ to nuclear proteins after activation by DNA strand breaks. PARP overactivation by massive DNA damage causes cell death via NAD+ and ATP depletion. Heretofore, PARP has been thought to be inactive under basal physiologic conditions. We now report high basal levels of PARP activity and DNA strand breaks in discrete neuronal populations of the brain, in ventricular ependymal and subependymal cells and in peripheral tissues. In some peripheral tissues, such as skeletal muscle, spleen, heart, and kidney, PARP activity is reduced only partially in mice with PARP-1 gene deletion (PARP-1−/−), implicating activity of alternative forms of PARP. Glutamate neurotransmission involving N-methyl-d-aspartate (NMDA) receptors and neuronal nitric oxide synthase (nNOS) activity in part mediates neuronal DNA strand breaks and PARP activity, which are diminished by NMDA antagonists and NOS inhibitors and also diminished in mice with targeted deletion of nNOS gene (nNOS−/−). An increase in NAD+ levels after treatment with NMDA antagonists or NOS inhibitors, as well as in nNOS−/− mice, indicates that basal glutamate-PARP activity regulates neuronal energy dynamics.
Solution chemistry within stress-corrosion cracks in alloy steels

Abstract The acidity and the concentrations of metal ions in the solution within progressing stress-corrosion(s.c.) cracks in some alloy steels were estimated. It was found that the solution is always pH 3·6–3·8 near the crack tip regardless of the particular type of alloy steel. In quenched-and-tempered alloy carbon steels the metallic elements are found in the solution in about the same proportions as in the steel. The relatively constant acidity produced during s.c.c. of the alloy steels is discussed in terms of the hydrolysis of Fe ions.
Contractions and expansions of Lie groups and the algebraic approach to scattering

A recently introduced algebraic approach to scattering is recast in the language of group contractions and expansions. The expansion describes the deformation of the physical states from one kind of symmetry to another and allows the algebraic derivation of an S-italic matrix. The method is illustrated for scattering models in n-italic-dimensional space of the type SO(n-italic,1) and SO(n-italic,m-italic) with m-italic> or =2.
Blockade of NMDA Receptors during Song Model Exposure Impairs Song Development in Juvenile Zebra Finches

Juvenile zebra finches (Poephila guttata) learn their courtship song by memorizing and then reproducing the song of an adult male. Several brain regions involved in song behavior contain N-methyl-D-aspartate (NMDA) receptors, and within one brain nucleus necessary for normal song development, the density of these receptors is twice as high in juveniles that are learning song then in adults that can no longer modify their songs. To determine whether NMDA receptor activation is necessary for normal song development, juvenile zebra finches were systemically injected with the NMDA receptor antagonist MK-801 (0.1 mg/kg) before exposure to an adult male tutor. One control group received the same number of MK-801 injections 24 h out of phase with tutoring, and another received saline before tutoring. In adulthood, birds given MK-801 before tutoring showed little evidence of learning from the tutor, and their songs contained abnormal syllables typical of untutored birds. In contrast, all control birds developed normal songs and copied an average of 72.5% of the tutor's syllables. Acute injections of MK-801 did not alter auditory brainstem evoked potentials in juveniles, indicating that the behavioral effects of MK-801 on song learning were not due to temporary hearing loss. Our results suggest that normal song development in juvenile zebra finches requires NMDA receptor activation during song model presentation.
Seasonal brain acetylcholinesterase activity in three species of shorebirds overwintering in Texas

There was no seasonal variation in average brain AChE activity for the 3 species of wild birds collected between October and February. Further work needs to be done, however, covering an even broader time frame which includes the reproductive cycle. It appears that some birds feeding at the mouth of an agricultural drain, at some distance from the nearest pesticide applications, were affected by AChE inhibitors.
Patterns of alliance formation and postconflict aggression indicate spotted hyaenas recognize third-party relationships

The social complexity hypothesis posits that natural selection has favoured the evolution of intelligence in animals living in challenging social environments. Although several primate species have been shown to use information about the social relationships between conspecifics in activities such as recruiting allies or reconciling after fights, this ability to recognize third-party relationships has never been demonstrated in nonprimate mammals. However, the social complexity hypothesis predicts that nonprimates should show some of the same cognitive abilities as primates when many features of their social lives resemble those of primates. Here we tested this prediction with data from a group of free-living spotted hyaenas, Crocuta crocuta, which are gregarious carnivores that live in primate-like societies. First, we examined whether hyaenas consistently supported dominant animals over subordinates when they joined in dyadic fights. The hyaenas overwhelmingly supported the dominant animal in each fight, even when both fighting animals ranked below the supporter, and even when the dominant individual was losing the fight. Next, we examined whether hyaenas preferentially attacked relatives of their opponents after a fight. We found that they were more likely to attack relatives of their opponents after a fight than during a control period, and that they were also more likely to attack relatives of their opponents than to attack low-ranking animals unrelated to their opponents. These results suggest that hyaenas can recognize third-party relationships, and support the idea that social complexity drives the evolution of intelligence in phylogenetically disparate taxa.
Stimulation of poly-β-hydroxybutyrate oxidation in Sphaerotilus discophorus by manganese and magnesium

When grown with glucose, S. discophorus synthesized large amounts of poly-β-hydroxybutyrate which accumulated intracellularly as sudanophilic granules. The rate of endogenous oxygen consumption by such cells was markedly increased by Mn++ and even more by Mg++. It has been shown that these inorganic ions stimulate the oxidation of the intracellular poly-β-hydroxybutyrate.
Adsorption of Alkanolamines onto Semiconductor Surfaces: Cadmium Selenide Photoluminescence as a Probe of Binding and Film Reactivity toward Carbon Dioxide

Films of ethanolamine, 3-aminopropanol, and 4-aminobutanol, 1−3, serve as transducers for the detection of CO2 when deposited onto emissive CdSe substrates: the band-gap photoluminescence (PL) intensity of the semiconductor is reversibly quenched by exposure to CO2, while uncoated CdSe samples display no response relative to a nitrogen reference ambient. Infrared (IR) spectra obtained with films of these alkanolamines and related alcohols and amines, 4−13, are consistent with selective reaction of the amine functionality in these films to form carbamates. The direction of the PL response corresponds to an enhancement of Lewis acidity accompanying the reaction with CO2, and use of a dead-layer model permits an estimation of the adduct-induced expansion of the depletion width as being roughly a few hundred Angstroms. Both IR and PL data reveal that the film response to CO2 begins at ∼0.1 atm and saturates by ∼0.3 atm, and their similarity indicates that the partition coefficient for binding CO2 to the bulk...