cssi/SciSciGPT-SciSciNet huggingface dataset:
SEMIQUINONE CATION ADSORPTION ON MONTMORILLONITE AS A FUNCTION OF SURFACE ACIDITY

Semiquinone cations derived from aromatic diamines by one-electron oxidation in aqueous solution possess characteristic colors that depend on hydrogen ion concentration. The colored free radicals are formed by oxidation on the surface of certain montmorillonite clay minerals, where they are stabilized by adsorption, apparently in cation exchange positions, but many clays react anomalously when the procedure is employed as a diagnostic test for montmorillonite. One of the problems involved is the chemical nature of the various semiquinones. Another is the effect of clay mineral crystal structure on the color that is produced. The dihydrochlorides of benzidine, p-phenylenediamine, and N, N-dimethyl-p-phenylenediamine in aqueous solution have been used with a centrifuged Wyoming bentonite (montmorillonite) and a centrifuged hectorite clay, each suspended in various buffered solutions, to study the pH effect and the quantity and nature of the semiquinones formed. Hypothetical structures differing by one hydrogen (or hydronium) ion have been assumed for two semiquinone forms of each diamine, each formula representing a distinct hue, with the divalent cation formed at low pH and the monovalent cation at a higher pH. Mixtures of the two cations were assumed to exist at intermediate acidities corresponding to mixtures of the two hues. A simple set of equations was postulated to describe these reactions, and the theory was tested experimentally by determining the amount of nitrogen adsorbed on each clay sample at a series of fixed pH values ranging from 0.5 to 6.5. The milligram atoms (mga) of nitrogen (or 2 x millimoles of diamine) adsorbed were found to increase with increasing pH in approximately the amount predicted in the range 1.0-4.2. In this pH range, however, the calculated base exchange capacity (BEC) for each clay was lower than the accepted value, presumably because an approximately constant fraction of the base exchange sites was occupied by nonexchangeable cations, probably aluminum and hydrogen ions. Amounts of base adsorbed were the same whether sodium or calcium ions were initially in exchange positions. At pH values of 5.5 and 6.5 the mga of nitrogen adsorbed showed a sharp increase, apparently because colloidally dispersed reagent diamine was formed as the free base and no aluminum or hydronium cations were adsorbed. When corrections were made for nonadsorbed free base (not adsorbed on exchange positions but physically adsorbed to the floccules) and, in the case of benzidine, for base lost in filtration, the calculated BEC's for each clay were in satisfactory agreement with accepted values.
Steady-State Versus Run-Down Tests of Structures

Steady-state and run-down vibration tests have been made on two modern multistory buildings. The response curves from the tests have been analyzed and the results compared. Damping determined from a run-down test is up to 2.5 times as large as the damping determined from a steady-state test. Accurate speed control is needed to precisely define the resonance curve from a steady-state test. It is concluded that the data from past forced vibration tests must be treated with caution. For various levels of excitation the damping in the lowest translational mode was found to vary between 0.5% and 1.0% for a steel frame structure and between 1.0% and 2.0% for a reinforced concrete building. These values of damping are considerably lower than values usually cited in the literature.
The Fundamental Ideas of the Integral and Differential Calculus

The fundamental limiting processes of calculus are integration and differentiation. Isolated instances of these processes of calculus were considered even in antiquity (culminating in the work of Archimedes), and with increasing frequency in the sixteenth and seventeenth centuries. However, the systematic development of calculus, started only in the seventeenth century, is ussually credited to the two great pioneers of science, Newton and Leibnitz. The key to this systematic development is the insight that the two processes of differentiation and integration, which had been treated separately, are intimately related by being reciprocal to each other.1
Green-wave phenology

Phenology, the traditional study of seasonal plant and animal activity driven by environmental factors, has found new relevance in research into global climate change1,2,3,4. Global phenology research so far has concentrated on measurements obtained by satellites, downplaying connections of these measures to information obtained on the surface1,4, perhaps because of a lack of conventional, surface-based phenological data. However, an integration of conventional and satellite-derived measures is needed to understand better the mid-latitude spring onset of photosynthesis, known as the ‘green wave’ or ‘green-up’5,6,7. Here I show how a surface-based green-wave model can extend the monitoring of climatic variability back to 1900, providing a longer-term context for the more limited, recent data obtained from satellites.
Knowledge acquisition via three learning processes in enterprise information portals: learning-by-investment, learning-by-doing, and learning-from-others

An enterprise information portal (EIP) is viewed as a knowledge community. Activity theory provides a framework to study such a community: members of an EIP conduct specific tasks that are assigned through a division of labor. Each member of an enterprise information portal can undergo three distinct types of learning processes: learning-by-investment, learning-by-doing, and learning-from-others. Through these three types of learning processes, each member achieves specialized knowledge that is related to his or her own task. Cumulative knowledge resulting from the learning processes is considered in terms of two distinct attributes: depth and breadth of knowledge. This paper formulates a mathematical model and defines the goal of an EIP member as maximizing the net benefits of knowledge resulting from individual investment and effort. Numerical examples are provided to analyze patterns of optimal investment and effort plans as well as the resulting accumulated knowledge. The results provide useful managerial implications. In business conditions characterized by high interest rates or high internal rate of returns, it is preferable for members to delay spending their resources for learning. Intensive investment and efforts to obtain knowledge are preferable when the discount rate of costs is high, when knowledge is durable, when the value of knowledge is high, when the initial level of knowledge is high, when the productivity of the learning process is high, and when sufficient knowledge is transferred from other members. On the other hand, the size of the EIP has a positive or negative effect depending on the attribute of knowledge and the productivity of learning processes. Further properties of the optimal decisions and learning processes are analyzed and discussed.
Aspirin for the Primary Prevention of Cardiovascular Events: A Systematic Evidence Review for the U.S. Preventive Services Task Force.

This systematic review for the U.S. Preventive Services Task Force examines evidence about the benefits of aspirin for the primary prevention of cardiovascular events in adults aged 40 years or old...
The Emergence of a New Form of Mexican Nationalism in San Antonio, Texas

This article explores the role played by a growing community of Mexican national entrepreneurs who are crafting a new form of Mexican nationalism in San Antonio, Texas. This population of Mexican business people is growing in size and influence in the city. The experiences of Mexican entrepreneurs differ from understood forms of Mexican immigration and acculturation to the United States. They differ from previous waves of affluent groups of political and religious Mexican refugees that flourished in San Antonio from 1908 through the 1940s. The integration and cultural adaptation experiences of Mexican entrepreneurs represent a new form of Mexican nationalism that engages both Mexican and American nationalisms in a bidirectional acculturation process. Blending attitudes, values, beliefs, and behaviours of both countries represent a new form of Mexican and American culture emerging in San Antonio at the beginning of the twenty-first century. To better understand the experiences and dynamics of these business people, this study builds on Pierre Bourdieu's principles of capital and power.
Novel Nanoporous Carbon Derived from Coal Tar Pitch/polyethylene Glycol Diacid Blends as Electrodes for Ultracapacitors

Nanoporous carbon materials with high surface area (1500 – 2000 m2/g) and narrow pore size distribution ranging from 1 – 3 nm were synthesized using polyfurfuryl alcohol/polyethylene glycol diacid and coal tar pitch/polymer blends. Electrical double layer capacitance of synthesized carbon was measured using cyclic voltammetry. There is a strong correlation between the surface area of the carbon and the specific capacitance. Carbon that had surface area smaller than 1000 m2/g had specific capacitance less than 50 F/g while the carbons having surface area from 1000 – 1500 m2/g showed specific capacitances in the order of 200 -250 F/g. It was shown that the mesoporosity and macroporosity in the parent carbon are critical for both activation and as well as the specific capacitance of the material. The use of these carbons in EDLCs was also demonstrated by fabricating a two-electrode ultracapacitor.
Carbon-14 Distribution in Peanut Fruit Parts During Maturation Following 14CO Treatment of Intact Plants1

Abstract Effects of sampling date and developmental stage on the distribution of radioactivity within the crude ethanol, lipid, and starch fractions from fruit, seed coat, and seed of peanut were investigated. Major differences were found between the first and fourth feeding dates in the amount of 14C-labeled photo-synthate translocated to individual peanut fruit parts. Maximum levels of radioactivity in the pericarp, seed coat, and seed were attained at progressively later developmental stages as the respective part became the dominant metabolic sink. Within the fruit, maximum radioactivity in starch was reached during early maturity (stage 3) and total radioactivity generally decreased with successive feeding dates. Thus the level of photosynthate being translocated to a given fruit decreases as more fruit develop on the plant. Observed relationships between level of radioactivity and specific activity of fruit-part components were interpreted as indicating that metabolic reserves are built up in the fr...
Re: Neonatal nitric oxide use: Predictors of response and financial implications

OBJECTIVE : To determine predictors of sustained response to inhaled nitric oxide (INO) and the financial impact of INO commercialization. DESIGN/METHODS : We evaluated the records of extra-corporeal membrane oxygenation (ECMO)-eligible infants consecutively treated with INO. We calculated the charges for INO therapy and for ECMO for each patient so treated. PUBLISHED BY ELSEVIER SCIENCE LTD.RESULTS: In total; 52 (59%) of 88 infants avoided ECMO; all received INO for >48 hour; all survived. A total of 36 infants received ECMO; 21 infants after 48 hours; and eight iinfants >48 hours of INO; one infant died. In iotal, 51 infants had sustained responses to INO; 19 infants were nonresponders and 18 were transient responders. Infants with PPHN and those older than 24 hours were more likely to respond to INO. Total INO charges for all 88 infants were $1,048,000. Total ECMO charges for the 36 infants so treated were $1.7,710,000. CONCLUSIONS: INO has added a charge-saving therapy to selective infants who can avoid ECMO.
Life cycle, demography, and production of Marenzelleria viridis in a salt marsh of southern New England

Population dynamics and production of the spionid polychaete Marenzelleria viridis were studied at Great Sippewissett salt marsh (Massachusetts, USA) for two years. Marenzelleria viridis was the main contributor in biomass and production to the macroinfaunal assemblages of the sandy organic sediments of the marsh. Marenzelleria viridis spawned during the cold part of the year and the appearance of settled larvae on sediments was observed from January to May. The density of M. viridis rose sharply from winter to late spring followed by a striking drop through summer. The estimated mean annual production of M. viridis was 60.0 g dry weight m2 during the first year and 26.3 g dry weight m2 during the second year. The population of M. viridis is affected by different processes during the year. The number of initial recruits seems to be largely governed by meteorological conditions. The numbers of recruits are then affected by competition for resources, and later, as predators become active, predation pressure determines the abundance of the population of M. viridis.
Social support and pain behavior

Research has shown that social support is generally associated with better adaptation to chronic disease. However, the role that social support plays in adjustment to chronic pain syndromes has received less research attention. The present study was designed to examine the relation of high versus low levels of social support to pain behavior in chronic pain patients. Fifty-one patients with chronic pain completed the Social Support Questionnaire (SSQ) and the McGill Pain Questionnaire. Patients were also observed using a standard observation system to assess pain behaviors. In order to compare pain behaviors displayed by subjects with high versus low levels of social support, a median split was performed on the 2 dimensions of the SSQ: satisfaction with support, and availability of people for support. The results indicated that pain behavior varied as a function of level of satisfaction with social support. Individuals reporting high satisfaction with social support exhibited significantly higher levels of total pain behavior and higher levels of individual pain behaviors such as guarding, rubbing, and bracing. There was no significant difference in total pain behaviors between those high versus low in terms of level of availability of support. There also were no differences between high versus low social support groups in total pain ratings as measured by the McGill Pain Questionnaire. The results are discussed in terms of an operant conditioning perspective on social support. Individuals who are satisfied with the quality of their social support may be satisfied because they receive positive reinforcement from the social environment when they engage in pain behavior.
InGaAs‐GaAs strained‐layer quantum well buried heterostructure lasers (λ>1 μm) by metalorganic chemical vapor deposition

Data are presented on long‐wavelength (λ>1 μm) strained‐layer InGaAs‐GaAs quantum well buried heterostructure lasers grown by a two‐step metalorganic chemical vapor deposition (MOCVD) process. Wet chemical etched mesas with an active region width of 3.5 μm are formed in a step‐graded InGaAs‐GaAs quantum well structure using an oxide mask. Selective MOCVD regrowth is used to form the buried heterostructure. Data are presented for devices having output powers of greater than 130 mW/facet, pulsed threshold currents of less than 7 mA, and internal quantum efficiencies of greater than 60%, for an emission wavelength of 1.074 μm. The near‐field patterns indicate stable index‐guided fundamental mode operation to greater than 30Ith.
Planetary science: Tectonic overturn on Enceladus

The south pole of Saturn's icy moon Enceladus is anomalously warm, geologically youthful and cryovolcanically active. Episodic convective overturn explains how the moon's modest sources of internal heat can be channelled into intense geological activity.
Digital materiality? How artifacts without matter, matter

It sounds rather odd to say that digital artifacts -- like software -- have material properties because people generally think of materials or materiality as physical substances such as wood, steel, and stone. Yet scholars increasingly talk about the "materiality" of digital artifacts. What do they mean? In this paper, I explore two definitions of the adjective "material" -- practical instantiation and significance -- in addition to its normal connotation as matter. I argue that treating materiality as the practical instantiation of theoretical ideas (like policies that allow women to vote help make material the idea that sexes are equal) or as what is significant in the explanation of a given context (like material evidence in a courtroom trial) provides a more useful framework for understanding how digital artifacts affect the process of organizing. I contend that moving away from linking materiality to notions of physical substance or matter may help scholars of technology integrate their work more centrally with studies of discourse, routine, institutions and other phenomena that lie at the core of organization theory, specifically, and social theory more broadly.
Aerobic metabolism of Crithidia fasciculata

1. 1. Asparagine, aspartate, glucose, glutamate, glutamine, alanine, isocitrate, and oxalacetate (at pH 7.4) stimulated the oxygen consumption of intact cells of C. fasciculata. 2. 2. Krebs' tricarboxylic acid cycle intermediates (excepting isocitrate and oxalacetate) did not stimulate the oxygen consumption of the intact cells at the same pH. 3. 3. The lack of stimulation observed at pH 7.4 was shown to be attributable to the impermeability of the cell membrane to the non-stimulatory substrates since succinate, malate, fumarate, cis-aconitate, and citrate stimulated the respiration of cell-free extracts, and alpha-ketoglutarate and pyruvate stimulated the O2 uptake of the intact cells at pH 3.0. 4. 4. Malonate inhibited the oxidation of succinate by the cell-free extracts, and the inhibition was partially released by increased concentrations of succinate. Mathematically the inhibition was shown to be of the competitive type. 5. 5. Aconitase, TPN-isocitric dehydrogenase, succinic dehydrogenase, malic dehydrogenase, fumarase, pyruvic oxidase, and acetic-thiokinase have been demonstrated in cell-free extracts. 6. 6. Succinic dehydrogenase was the least active of the enzymes studied; lending an explanation to the production of succinic acid as the predominant end-product of aerobic carbohydrate metabolism in this species. 7. 7. The results present strong evidence for the operation of the tricarboxylic acid cycle as a metabolic pathway in C. fasciculata.
Generation and Analysis of an Artificial Gene Dosage Series in Tomato to Study the Mechanisms by Which the Cloned Quantitative Trait Locus fw2.2 Controls Fruit Size

It has been proposed that fw2.2 encodes a negative fruit-growth regulator that underlies natural fruit-size variation in tomato ( Lycopersicon spp.) via heterochronic allelic variation of fw2.2 expression, rather than by variation in the structural protein itself. To further test the negative regulator and the transcriptional control hypotheses, a gene dosage series was constructed, which produced a wider range of fw2.2 transcript accumulation than can be found in natural tomato populations. Fruit developmental analyses revealed that fw2.2 transcript levels were highly correlated (negatively) with fruit mass, supporting the negative regulator and transcriptional regulation hypotheses. Further, the effect of fw2.2 on fruit mass was mediated by repressing three- and two-dimensional cell division in placental and pericarp tissues, respectively. Finally, fw2.2 had little effect on fertility and seed size/number, indicating that fruit size effects of fw2.2 are due largely to expression in the maternal tissues of developing fruit and not mediated through fertility or seed-setting-related processes.
Loss of palladium from model platinum-palladium supported catalysts during annealing

Abstract The phenomena taking place during the annealing of bimetallic-supported catalysts may differ in several respects from those involving monometallic-supported systems. One such phenomenon can be the preferential loss from the catalyst of one of its active components. Reported here are the results of experiments on the thermal stability of model, supported platinum-palladium catalysts in which preferential loss of palladium was indeed observed. These experiments sought to determine the factors responsible for the loss. The variables investigated included the atmosphere surrounding the catalyst, the substrate material, and the effects of time and temperature.
Lysosomes in the cessation of vitellogenin secretion by the mosquito fat body; selective degradation of Golgi complexes and secretory granules

A massive and selective degradation of Golgi complexes, secretory granules, and RER is the mechanism responsible for the rapid termination of Vg secretion by trophocytes of the mosquito fat body. These cells are involved in an intensive synthesis of a glycoprotein, vitellogenin (Vg), which is accumulated by developing oocytes as yolk protein. Previously, assays for lysosomal enzymes have demonstrated that the cessation of Vg synthesis is characterized by a sharp increase in lysosomal activity; and fluorescent microscopy has shown that, during this intense lysosomal activity, Vg concentrates in lysosomes. In this report, electron microscopy combined with cytochemistry for lysosomal enzymes and localization of Vg with colloidal gold immunocytochemistry has shown that this lysosomal activity is directed towards selective degradation of Vg and organelles associated with its synthesis and secretion. Three organelles undergo lysosomal breakdown: the Golgi complex, Vg-containing secretory granules, and RER. The degradation of Golgi complexes occurs in two steps similar to that for RER: first, the organelle is sequestered by double isolation membranes, and the resulting pre-lysosome then fuses with a primary or secondary lysosome. In contrast, mature Vg-containing secretory granules fuse with lysosomes directly. This combination of crino- and autophagy is a specific, highly intense, and precisely timed event.
Marking Single Neurons by Staining with Intracellular Recording Microelectrodes

Glass microelectrodes filled with a saturated solution of methyl blue or fast green in 1.0 M potassium acetate can be used to mark penetrated ne. urons from which intracellular recordings have been made. Many cells can be marked in one experiment and can easily be located in subsequent histologic section.
Epistemological development and academic performance among secondary students.

This is an investigation of the development of secondary students' beliefs about the nature of knowledge and learning, or epistemological beliefs, and the influence that these beliefs have on academic performance. An epistemological questionnaire that assesses students' beliefs about simple knowledge, certain knowledge, quick learning, and fixed ability to learn was modified and administered to more than 1,000 high school students. Factor analysis of students' responses replicated the factor structure found in previous research. Differences in epistemological beliefs among students across the high school years and between genders were examined. Belief in simple knowledge, certain knowledge, and quick learning decreased from freshman to senior year
Interactive clustering and merging with a new fuzzy expected value

Abstract Major problems exist in both crisp and fuzzy clustering algorithms. The fuzzy c-means type of algorithms use weights determined by a power m of inverse distances that remains fixed over all iterations and over all clusters, even though smaller clusters should have a larger m. Our method uses a different “distance” for each cluster that changes over the early iterations to fit the clusters. Comparisons show improved results. We also address other perplexing problems in clustering: (i) find the optimal number K of clusters; (ii) assess the validity of a given clustering; (iii) prevent the selection of seed vectors as initial prototypes from affecting the clustering; (iv) prevent the order of merging from affecting the clustering; and (v) permit the clusters to form more natural shapes rather than forcing them into normed balls of the distance function. We employ a relatively large number K of uniformly randomly distributed seeds and then thin them to leave fewer uniformly distributed seeds. Next, the main loop iterates by assigning the feature vectors and computing new fuzzy prototypes. Our fuzzy merging then merges any clusters that are too close to each other. We use a modified Xie-Bene validity measure as the goodness of clustering measure for multiple values of K in a user-interaction approach where the user selects two parameters (for eliminating clusters and merging clusters after viewing the results thus far). The algorithm is compared with the fuzzy c-means on the iris data and on the Wisconsin breast cancer data.
Empirical Relations of Crease Recovery and Time

A technique for measuring short-time crease recovery is described. Data from this method and from the standard Monsanto method were used to establish several empiri cal relationships between crease recovery and time which give linear plots and which permit extrapolation to very short and very long times. One of these relationships gives a linear plot over the time range of 5 sec. to several days. These relationships lead to several new parameters for characterizing fabric recovery : very short time crease recovery, rate of delayed recovery, and recovery after infinite time. These parameters depend primarily on fiber type and to a much lesser extent on fabric construction.
On the function of guanosine triphosphate in the formation of N-acetyl-phenylalanyl puromycin.

In the presence of washed E. coli ribosomes, the formation of N-Ac-phenylalanyl puromycin from N-Ac-phe-RNA and puromycin at 5 mM Mg++ does not proceed unless initiation factors (ribosomal wash) and GTP are also added. GMPPCP cannot replace GTP under these conditions. However, if the N-Ac-Phe-RNA is prebound to the ribosomes in the presence of initiation factors and GMPPCP, and the N-Ac-phe-RNA-ribosome-polyU complex is first diluted and adsorbed on a cellulose nitrate filter, then the bound N-Ac-phe-RNA reacts efficiently with puromycin. Thus, in this system the conversion of GTP to GDP does not appear to be a prerequisite for the binding of N-Ac-phe-RNA to the ribosome in a puromycin-reactive state.
Irradiation Effects in Space Solar Cells Made of Multiple Absorbers

Solar cells made of multiple absorbers are a commonly used approach for improving efficiency due to their extended range of spectral sensitivity. Indeed, efficiencies nearing the theoretical maximum have been achieved with a triple-junction device made of In0.51Ga0.49P (InGaP2), GaAs, and Ge solar cells connected in series. For extraterrestrial applications, there is the added requirement of radiation tolerance. The main challenge for space power-generation is therefore the development of highly efficient and radiation-tolerant devices. We have investigated several aspects of the radiation response of solar cells made of multiple absorbers, such as multijunction devices and quantum-well solar cells. Novel possibilities such as quantumdot solar cells and ordered-disordered heterostructures are proposed.
Ecology and Control of the Sand Fly Vectors of Leishmania donovani in East Africa, with Special Emphasis on Phlebotomus orientalis

A literature review is provided on the state of knowledge of the ecology and control of the sand fly vectors of Leishmania donovani in East Africa, with a special emphasis on Phlebotomus orientalis. Visceral leishmaniasis caused by L. donovani is a major health problem in several areas in East Africa. Studies conducted in the past 70 years identified P. orientalis Parrot and P. martini Parrot as the principal vectors of L. donovani in Sudan, Ethiopia and Kenya and P. celiae Minter as the secondary vector of the parasite in one focus in Ethiopia. Findings on sand fly fauna and other circumstantial evidence indicate that P. martini is also responsible for transmission of L. donovani in VL endemic foci of Somalia and Uganda. Several studies showed that P. orientalis occupy distinct habitat characterized by black cotton soil and Acacia seyal-Balanites aegyptiaca vegetation, whereas P. martini and P. celiae are associated with termite mounds. Little knowledge exists on effective control measures of sand fly vectors of L. donovani in East Africa. However, recent evidence showed that use of insecticide impregnated bednets and insect repellents may reduce exposure to the bites of P. orientalis.
Osteoarthritis of the Ankle: Bridging Concepts in Basic Science with Clinical Care

Trends in science are beginning to suggest that cartilage degeneration may be related to a chronic imbalance in extracellular matrix metabolism. In cartilage, a combination of biomechanical, biochemical, and matrix-related signaling pathways regulates the equilibrium between cartilage anabolism and catabolism. A potential limitation of many current treatments of osteoarthritis is that they may not comprehensively restore regulation of a balance between cartilage anabolism and catabolism.
Silicon increases boron tolerance and reduces oxidative damage of wheat grown in soil with excess boron

The effect of silicon on the growth, boron concentrations, malondialdehyde (MDA) content, lipoxygenase (LOX) activity, proline (PRO) and H2O2 accumulation, and the activities of major antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX)] and non-enzymatic antioxidants (AA) of wheat grown in soil originally with toxic B concentrations were investigated. Applied of 5.0 and 10.0 mM Si to the B toxic soil significantly increased Si concentration of the wheat and counteracted the deleterious effects of B on shoot growth. The contents of PRO, H2O2, MDA, and LOX activity of wheat grown in B toxic soil were significantly reduced by Si treatments. Compared with control plants, the activities of SOD, CAT, APX and content of AA were decreased by applied Si. Based on the present work, it can be concluded that Si alleviates B toxicity of wheat by preventing oxidative membrane damage and also translocation of B from root to shoot and/or soil to plant.
Influence of microstructure on the carbon damping peak in iron-carbon alloys

Abstract The internal-friction peak due to the stress-induced migration of carbon in b.c.c. iron has been studied in a series of high-purity iron-carbon alloys with variations in grain size and intercarbide distance. It is found that when these microstructural parameters are small the height of the carbon damping peak does not correspond to the equilibrium solubility at the solutionizing temperature. An explanation is suggested in terms of the rapid precipitation of carbon during the quench from the solution temperature, the sites being provided by grain boundaries or ferrite-carbide interfaces. Only when the grain size and mean distance between carbides are sufficiently large can the equilibrated carbon content be retained in solution on quenching to room temperature. The same phenomena are involved when martensite is tempered to ferrite-carbide aggregates.
Environmentally Assisted Growth Rate Response of Nonsensitized AISI 316 Grade Stainless Steels in High Temperature Water

Abstract Experiments were performed on a compact tension specimen of AISI 316L stainless steel (SS) to determine its susceptibility to intergranular environmentally assisted cracking in 288 C water. Crack growth rates were measured using a reversing DC potential drop technique as a function of mechanical loading variables in 288 C water containing 200 ppb dissolved oxygen and 0.5 µS/cm Na2SO4. The specimen was tested in the as-received plus 650 C/1 h heat treatment condition. The crack propagation rate at constant stress intensity of 27.5 MPa m was 4.2×10−9 cm/s (6.0×10−6 in./h), about a factor of 8 lower than the typical crack growth rate for sensitized AISI 304 SS (EPR=15 C/cm2) under similar test conditions. Additionally, a database of crack growth rates on fracture mechanics specimens in high temperature water for AISI 316L and 316NG SSs was developed and compared with predictive modeling. The accuracy of the prediction algorithms has been demonstrated for sensitized AISI 304 SSs; an objective of this...
Determination of SBS Induced Damage Limits in Large Fused Silica Optics for Intense, Time-Varying Laser Pulses

The propagation of intense 3rd harmonic light (0351 μm) through large optical components of the Nova laser results in fracture damage of the center of the component. This damage is caused by an intense acoustical wave brought to focus in the center by reflecting off the circular edge of the optic. The source of this wave is light generated by transverse stimulated Brillouin scattering (SBS). By taking into account the transient gain characteristics of the SBS, we can correctly predict the pulse energy that would cause damage for any time variation in intensity in the pump beam, and predict the relative intensity of the Brillouin light. Our model is based on the transient behavior of a first order linear system.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Efficacy of lomefloxacin as compared to norfloxacin in the treatment of uncomplicated urinary tract infections in adults

The efficacy and safety of 7-10-day courses of lomefloxacin (single daily dose of 400 mg) or norfloxacin (twice-daily doses of 400 mg) for the treatment of uncomplicated urinary tract infections were compared in two large, multicenter, randomized trials. This article presents the combined results of these trials, which were conducted in a total of 27 centers throughout the United States. A total of 727 adults, mostly women, with symptoms of acute urinary tract infection were enrolled; 370 patients were randomized to lomefloxacin treatment, and 357 received norfloxacin. The bacteriologic cure rate at 5-9 days post-therapy was 98.2% in the lomefloxacin group and 96.3% in the norfloxacin group (p = nonsignificant). The clinical success rate of 99.1% in the lomefloxacin group was significantly higher than the success rate of 93.5% in the norfloxacin group (p = 0.002). Adverse events were reported by 157 lomefloxacin-treated patients and 129 patients receiving norfloxacin. Adverse events attributable to drug treatment occurred in 41 patients (11.1%) in the lomefloxacin group and 27 (7.6%) in the norfloxacin group. Eight lomefloxacin (2.2%) and three norfloxacin patients (0.8%) were withdrawn from treatment because of adverse events probably attributable to the drug. The incidence of dizziness, tremor, and photosensitivity rash was higher in the lomefloxacin group than in the norfloxacin group, while the incidence of nausea was higher in the norfloxacin group. The results of these trials demonstrate that once-daily administration of 400 mg lomefloxacin is as safe and effective clinically as, and superior bacteriologically to, twice-daily administration of 400 mg norfloxacin in the treatment of acute uncomplicated urinary tract infections in adult patients.
Effects of Conserved Residues on the Regulation of Rabbit Muscle Pyruvate Kinase

Abstract A cDNA encoding the complete rabbit muscle pyruvate kinase isozyme (RMPK) was cloned using the method of rapid amplification of cDNA ends. The sequence encodes a polypeptide chain of 530 amino acids which differs in three amino acid residues from a sequence reported by Larsen et al. (Larsen, T. M., Laughlin, T., Holden, H. M., Rayment, I., and Reed, G. H.(1994) Biochemistry 33, 6301-6309). Glu-Gln and Ala were identified instead of Asp-Glu and Ser, respectively. The recombinant RMPK was overexpressed in the Escherichia coli JM 105 cells. Purified recombinant pyruvate kinase displayed identical physical and enzymatic properties as the authentic enzyme. Three point mutants of RMPK were constructed using site-directed mutagenesis. Like the wild type RMPK, sedimentation, and CD spectroscopic studies show that purified R119C and T340M are tetrameric proteins with similar secondary and tertiary structures. Mutant R119C enzyme exhibits 0.6% of the value of k and an order of magnitude decrease in the apparent affinity for ADP as compared to the wild type PK. The overall response to inhibitor and activator, Phe and FBP, respectively, were not affected by the R119C mutation. The T340M mutant enzyme is only half as active as the wild type PK. T340M is more susceptible to inhibition by Phe but apparently is not responsive to the activator FBP. The kinetic behavior of the Q377K mutant enzyme is in between that of the R119C and T340M mutants exhibiting 5% of the wild type enzymatic activity and an enhanced sensitivity to the inhibitor, Phe, while maintaining the same responsiveness to FBP and apparent affinities for substrates. The significant decrease in activity in all three mutants mimics the exact consequences of the same mutations in human erythrocyte PK from hemolytic anemia patients. Thus, this study demonstrates not only the effects of these conserved residues in the regulatory properties of mammalian PK but also that the observed effects are most likely applicable to all isozymic forms of PK.
Introduction to the intelligence special issue on the development of expertise: is ability necessary?

Abstract The question asked in this special issue is if abilities are necessary to explain the development of expert performance. The issue consists of eight papers written by experts on expertise. A brief but incomplete summary of these papers is presented in this introduction. Ericsson presents his rebuttal to these eight papers. He argues that much of what has been presented is not relevant to expertise when it is defined as repeatable, high level performance by an adult. The eight authors then briefly respond to Ericsson's rebuttal. This issue is of major importance to intelligence researchers since it was Binet's original goal to find interventions that would undo the correlation between IQ and educational outcome. An example of height and National Basketball Association (NBA) players is used to demonstrate some of the methodological difficulties of expertise research when study samples are selected from experts. Height is largely uncorrelated with either points scored or salary of NBA players nonsensically suggesting that height is not important in basketball. The evidence presented here suggests that intelligence is important in the development of expertise and the lack of correlation with IQ sometimes found is probably due to methodological problems. Despite these problems, research on expertise has the potential of identifying factors that could be important in achieving Binet's goal of undoing the correlation between IQ and educational outcomes in the future.
Acute Lead Toxicosis in a Harbor Seal (Phoca vitulina richardsi) Consequent to Ingestion of a Lead Fishing Sinker

An adult female harbor seal (Phoca vitulina richardsi) stranded in northern California on 25 June 2004, exhibited progressive weakness, disorientation, and seizures, and despite therapy, died within 4 days. On pathologic examination, a lead fishing sinker was in the stomach, and changes in the brain, heart, kidney, liver, lymph nodes, and spleen were supportive of acute lead toxicosis. The diagnosis was made on the basis of concentrations of lead in the sinker (90–98% lead), antemortem whole blood (0.66 ppm), and postmortem tissues (84 ppm, wet weight liver). This first documented case of lead toxicosis in a wild marine mammal demonstrates an additional way in which human fishing activities can harm marine mammals.
Effects of tumor necrosis factor alpha on skeletal muscle amino acid metabolism studied in-vivo.

The present study was performed to determine the chronology of the effects of a single 50 ug subcutaneous dose of TNF on food intake, weight gain, and skeletal muscle protein metabolism in normal rats. Earlier work demonstrated that a single subcutaneous dose of 50 ug of tumor necrosis factor alpha (TNF) significantly increased skeletal muscle protein synthesis and breakdown in the tumor bearing rat [1]. Some of the earlier work demonstrated that TNF can reduce food intake, weight gain and enhance muscle catabolism.Twenty-five male Sprague Dawley rats were randomized assigned to treatment or saline arms of the study. Rates of in vivo incorporation of L-1-14C-leucine into skeletal muscle were measured by the flooding dose technique. Rats were studied 6 and 60 hours after TNF or saline.Six hours after administration of the TNF, the total skeletal muscle amino acid concentration was significantly reduced by 20%. The greatest reductions were seen in lysine, arginine, and isoleucine (39-53%) followed by serine...
Using Lie algebra for shape estimation of medical snake robots

Highly articulated robots have the potential to play a key role in minimally invasive surgeries by providing improved access to hard-to-reach anatomy. Estimating their shape inside the body and combining it with 3D preoperative scans of the anatomy enable the surgeon to visualize how the entire robot interacts with the internal organs. As the robot progresses inside the body, the position and orientation of every link comprising the robot, evolves over a coordinate-free Lie algebra, se(3). To capture the full motion and uncertainty of the system, we use an extended Kalman filter where the state vector is defined using elements of se(3). We show that this approach describes the shape of the robot more accurately, than the ones where the state vector is a conventional parametrization, such as Cartesian coordinates and Euler angles. We perform two experiments to demonstrate the effectiveness of this new filtering approach.
Effects of Different Listening-While-Reading Rates on Comprehension in Secondary Students with Reading Deficits

Abstract Effects of instructing students to read silently as another person reads aloud (listening-while-reading) on comprehension in secondary students with learning disabilities were examined. Two separate treatment conditions were implemented. During student rate listening-while-reading, (SLWR), experimenters read aloud at rates that approximated each student's oral reading rate. During fast rate listening-while-reading, (FLWR), experimenters increased their reading rates. A silent reading (SR) control condition was also implemented. Following each intervention the students answered five literal and five inferential questions. SLWR resulted in lower inferential accuracy than FLWR and SR. Discussion focuses on future research and implications for accommodating secondary students with reading skills deficits in general education classrooms.
The Effect of Continuous Flow Left Ventricular Assist Device (CF-LVAD) Implantation on Serum Uric Acid Levels

Purpose Hyperuricemia is common in patients with severe heart failure. Change in uric acid level following continuous flow ventricular assist device (CF-VAD) placement has not previously been reported. We hypothesized that uric acid levels would decrease following CF-VAD implant. Methods and Materials 238 consecutive patients undergoing implantation of a CF-LVAD between 6/2005 and 4/2012 were identified. Retrospective chart review was conducted in the 36 patients who were noted to have serum uric acid values measured prior to and following CF-LVAD implant. Results Mean age was 58.6 ± 9.5 years; 29 were male. Serum uric acid values decreased significantly from 9.2± 2.7 to 6.6± 3.1 mg/dL following implant (p Conclusions Serum uric acid values decreased after CF-LVAD implant, although several mechanisms may be operative. Further work may clarify these mechanisms. [ figure 1 ] Characteristics at baseline and on LVAD therapy Characteristics All patients (n=36) - Pre-LVAD All patients (n=36) - On LVAD p-value Age (years) 58.7±9.5 Sex 29M/7F Uric acid (mg/dL) 9.2±2.7 6.6±3.1 Mean Cr. (mg/dL) 1.56±0.52 1.39±0.66 0.20 Mean RAP (mmHg) 14±6 13± 9 0.40 Mean PAP (mmHg) 36±8 28±9 Mean PCWP (mmHg) 24±7 17±9 Diuretic use (furosemide equivalent mg/d) 125±89 87±103 0.07
Households, forests, and fire hazard vulnerability in the American West: A case study of a California community

Abstract Due to amplified biophysical risks, rapid population growth, and inadequacies of existing political mechanisms, wildland—urban interface (WUI) fire hazards have become increasingly acute throughout the American West. Using a case study approach, I test the applicability of four social determinants of household level WUI fire hazard vulnerability in the community of Forest Ranch, California. Previous studies have independently identified (1) risk perceptions, (2) amenity value conflicts, and (3) institutional incentive structures as determinants of household fire hazard vulnerability. I introduce (4) political economic constraints as determinants. findings confirm the role of three social determinants in household risk management decision-making: while determinant (1) is not a significant correlate of household vulnerability, determinants (2)–(4) are significant correlates. Also, findings demonstrate that political economic theory offers concepts applicable to studies of WUI hazard vulnerability. ...
Increase in thickness of cerebral cortex in response to environmental enrichment in brattleboro rats deficient in vasopressin

Abstract Changes in cortical thickness were observed in male Brattleboro rats killed at 60 and 90 days of age from standard environmental conditions, and at 90 days of age after 30 days in an enriched condition. When 60- and 90-day-old standard animals were compared, both homozygous Brattleboro rats with diabetes insipidus and also heterozygous nondiabetic rats showed reduction in cortical thickness with age. When 90-day-old enriched animals were compared with the 90-day-old standard group: the homozygous rats with enrichment showed statistically significant thickening in frontal, parietal, and occipital cortices, and the heterozygous rats showed statistically significant thickening with enrichment in parietal and occipital regions. In both heterozygous and homozygous Brattleboro rats the most significant increases were in the occipital cortex. These results are in general agreement with previously reported developmental and enrichment studies in the normal Long-Evans strain of rats, with an important difference: both heterozygous and homozygous animals showed greater and more generalized response to enrichment. We speculate that this greater responsiveness to environmentally induced cortical thickening in the Brattleboro rats is due to increased arousal, and it may be related to alterations in norepinephrine concentration and/or turnover associated with absence of, or abnormalities in, vasopressin in the brain.
Discovering the Ebb and Flow of Ideas from Text Corpora

Changes in word usage patterns in text corpora can yield insight into historic events and discoveries.
The Precedence Effect in Sound Localization

In ordinary listening environments, acoustic signals reaching the ears directly from real sound sources are followed after a few milliseconds by early reflections arriving from nearby surfaces. Early reflections are spectrotemporally similar to their source signals but commonly carry spatial acoustic cues unrelated to the source location. Humans and many other animals, including nonmammalian and even invertebrate animals, are nonetheless able to effectively localize sound sources in such environments, even in the absence of disambiguating visual cues. Robust source localization despite concurrent or nearly concurrent spurious spatial acoustic information is commonly attributed to an assortment of perceptual phenomena collectively termed “the precedence effect,” characterizing the perceptual dominance of spatial information carried by the first-arriving signal. Here, we highlight recent progress and changes in the understanding of the precedence effect and related phenomena.