cssi/SciSciGPT-SciSciNet huggingface dataset:
Discrete Element Method Analysis of Railtrack Ballast Degradation during Cyclic Loading

Ballast materials forming part of railway structures are subjected to cyclic loads. As a result of these loads, ballast densification, aggregate degradation, and lateral spread of the ballast material underneath the ties takes place inducing permanent deformations on the railways. Maintenance and rehabilitation costs of railtracks due to problems related with ballast performance are substantial, and millions of dollars are annually spent around the world in these activities. Understanding the crushable behavior of railtrack ballast could lead to the design of better railways that will reduce these costs. This paper presents the results of two discrete element method simulations intended to study the effect of crushing on the behavior of a simulated track ballast material forming part of a simulated track section. Even though the two simulations consider the same idealized material, crushing was allowed only in one simulation. The simulated track sections were subjected to a cyclic load, and the values of permanent deformation as a function of number of cycles were recorded. The obtained results showed that the induced permanent deformation strongly increased when considering particle crushing even though only a few particles were broken. Moreover, it was found that crushing concentrated underneath the simulated sleepers. Snap shots of the track sections are presented allowing a visualization of the evolution of crushing.
Abstract 1037: Lysophosphatidic acid upregulates Bcl-2 production and secretion in ovarian cancer cells

Lysophosphatidic acid (LPA) is elevated in the plasma and ascites fluid of ovarian cancer (OC) patients and has been proposed as a diagnostic tool for OC. LPA is the simplest glycerophospholipid and has been shown to have an extensive range of biological activities. LPA is involved in wound healing and tissue regeneration, cell proliferation and survival, platelet aggregation, and tumor cell invasion. In addition, LPA elicits anti-apoptotic activity through upregulation of Bcl-2 in other systems. Bcl-2, the prototypical anti-apoptotic protein, is commonly overexpressed in OC. The purpose of this study was to determine whether LPA regulates Bcl-2 in OC. Using an in vitro cell culture model system, OC cells were treated ± LPA. We found that LPA increased Bcl-2 expression at the protein and message levels using western immunoblotting, ELISA and luciferase reporter assays. Interestingly, LPA also promoted Bcl-2 secretion by OC cells, which is a novel action of Bcl-2. Secreted Bcl-2 appears to modulate angiogenesis by affecting endothelial cell migration as well as tube formation in an in vitro angiogenesis assay using HUVECs. Given that both LPA and Bcl-2 are potential targets in ovarian cancer intervention, elucidating their inter- and regulatory relationships may be of clinical importance and warrants further investigation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1037.
Using Ada and C++ in computer science education

Undergraduate students of Computer Science or Software Engineering must become familiar with imperative programming languages, due to the extensive use of these languages in industry. Perhaps the two most interesting imperative languages, from a technical standpoint, are Ada and C++, as these two languages include a number of modern features and enjoy widespread popularity. We argue that a four-year undergraduate curriculum in Computer Science which emphasizes imperative programming languages benefits from a thorough coverage of Ada in the first two years, while deferring the direct use of C++ until the junior year. The argument is supported by an overview of the technical features of Ada and C++ which both aid and hinder the learning of software development skills.
E-innovation: an emerging platform for a networked economy

This paper aims to examine the changes to innovation brought about by the internet, and paints an overall picture about e-innovation. Based on a systematic survey of the current efforts made by industry and academia in using the term of e-innovation and in promoting the concept of e-innovation, it found that e-innovation is expanding traditional innovation in two aspects: application of innovation and delivery of innovation. These expansions are leading e-innovation to become a new platform, which is characterised by five Ds: digital form, distributed nature, decoupling activities, dedication to channel change, and deployment of different rules. To develop further the platform, six barriers have to be overcome.
Prenatal, perinatal, and neonatal factors associated with autism spectrum disorders.

OBJECTIVE. To investigate prenatal, perinatal, and neonatal risk factors for autism spectrum disorders by using participants identified through broad ascertainment and reliable classification methods. METHODS. The targeted population was 8-year-old children born in 1994 and residing in 1 of the 3 most populous counties in Utah who were identified as having an autism spectrum disorder on the basis of methodology used by the 2002 Autism and Developmental Disabilities Monitoring Network. Of those identified, 132 children (115 boys, 17 girls) had birth certificate records available. Each child was matched by gender and birth year to 100 controls (11 500 boys, 1700 girls) from the birth certificate database in a nested case-control design. Birth certificate records of participants and controls were surveyed for 23 potentially pathologic prenatal, perinatal, and neonatal factors. RESULTS. The prenatal factors that occurred significantly more frequently among children with autism spectrum disorders were advanced maternal age and parity. Increased duration of education among mothers of children with autism spectrum disorders was small but statistically significant. Significant perinatal factors were breech presentation and primary cesarean delivery. When corrected for breech presentation, a known indication for cesarean delivery, the association between primary cesarean delivery and autism spectrum disorders was eliminated. There were no significant associations found between autism spectrum disorders and neonatal factors. CONCLUSIONS. In the absence of other complications suggesting fetal distress, the association between breech presentation and autism spectrum disorders in this study suggests a shared etiology rather than causal relationship. Additional investigation focused on both genetic and environmental factors that link these autism spectrum disorder risk factors individually or collectively is needed.
Effect of Iron-deficiency Anæmia on the Metabolism of the Heterogenic Hæmoglobins in Sickle Cell Trait

HAEMOGLOBIN S is found in a concentration of 35–45 per cent of the total haemoglobin in most individuals with sickle cell trait under non-stress conditions1,2. It is believed that the relative concentrations of the heterogenic haemoglobins, haemoglobin S and haemoglobin A, in these individuals remain fairly constant throughout life. However, on rare occasions, changes in these relative concentrations have been demonstrated. In 1956, Zuelzer, Neel and Robinson3 described an 8-month-old infant with sickle cell trait and severe iron-deficiency anaemia in whom haemoglobin S could not be demonstrated by paper electrophoresis until the anaemia had been corrected with iron therapy. More recently, Heller, Yakulis, Epstein and Friedland4 have described a patient with sickle cell trait and coexistent megaloblastic anaemia in whom the haemoglobin S concentration increased from an initial level of 10.6 per cent to a concentration of 38.5 per cent following therapy with folic acid.
Identification of a Drosophila glucose receptor using Ca2+ imaging of single chemosensory neurons.

Evaluation of food compounds by chemosensory cells is essential for animals to make appropriate feeding decisions. In the fruit fly Drosophila melanogaster, structurally diverse chemicals are detected by multimeric receptors composed of members of a large family of Gustatory receptor (Gr) proteins. Putative sugar and bitter receptors are expressed in distinct subsets of Gustatory Receptor Neurons (GRN) of taste sensilla, thereby assigning distinct taste qualities to sugars and bitter tasting compounds, respectively. Here we report a Ca2+ imaging method that allows association of ligand-mediated responses to a single GRN. We find that different sweet neurons exhibit distinct response profiles when stimulated with various sugars, and likewise, different bitter neurons exhibit distinct response profiles when stimulated with a set of bitter chemicals. These observations suggest that individual neurons within a taste modality are represented by distinct repertoires of sweet and bitter taste receptors, respectively. Furthermore, we employed this novel method to identify glucose as the primary ligand for the sugar receptor Gr61a, which is not only expressed in sweet sensing neurons of classical chemosensory sensilla, but also in two supersensitive neurons of atypical taste sensilla. Thus, single cell Ca2+ imaging can be employed as a powerful tool to identify ligands for orphan Gr proteins.
Effect of single dose of intravenous Heparin on plasma levels of angiogenic growth factors

M, Matsuda T, Nakao S. Elevated plasma levels of free-form of TFPI antigen in hypercholesterolemic patients. Atherosclerosis 2001;154:203–212. 15. Petit L, Lesnik P, Dachet C, Moreau M, Chapman J. Tissue factor pathway inhibitor is expressed by human monocyte-derived macrophages. Relationship to tissue factor induction by cholesterol and oxidized LDL. Arterioscler Thromb Vasc Biol 1999;19:309–315. 16. Koh KK. Effects of HMG-CoA reductase inhibitor on hemostasis. Int J Cardiol 2000;76:21–30. 17. Koh KK. Effects of statins on vascular wall: vasomotor function, inflammation, and plaque stability. Cardiovasc Res 2000;47:648–657. 18. Diomede L, Albani D, Sottocorno M, Donati MB, Bianchi M, Fruscella P, Salmona M. In vivo anti-inflammatory effect of statins is mediated by nonsterol mevalonate products. Arterioscler Thromb Vasc Biol 2001;21:1327–1332. 19. Sparrow CP, Burton CA, Hernandez M, Mundt S, Hassing H, Patel S, Rosa R, Hermanowski-Vosatka A, Wang PR, Zhang D, et al. Simvastatin has antiinflammatory and antiatherosclerotic activities independent of plasma cholesterol lowering. Arterioscler Thromb Vasc Biol 2001;21:115–121. 20. Wilson SH, Simari RD, Best PJM, Peterson TE, Lerman LO, Aviram M, Nath KA, Holmes DR Jr, Lerman A. Simvastatin preserves coronary endothelial function in hypercholesterolemia in the absence of lipid lowering. Arterioscler Thromb Vasc Biol 2001;21:122–128.
Isobaric Bubble Growth: A Consequence of Altering Atmospheric Gas

During certain treatments of decompression sickness following dives made with compressed air, the U.S. Navy advocates breathing helium-oxygen mixtures. However, stable nitrogen bubbles created within gelatin by decompression have been found to enlarge when the atmosphere was switched from nitrogen to helium without changing ambient pressure. This suggests that decompression sickness would be worsened by switching from nitrogen to helium in the breathing gas mixture.
High-order harmonic generation from intense laser-driven inner electrons of Rydberg atoms

By solving the time-dependent Schroedinger equation of a two-electron system, we demonstrate that efficient high-order harmonics can be emitted by inner electrons of Rydberg atoms exposed to an intense laser pulse, while the Rydberg electron turns out to be stabilized. Due to stabilization of the Rydberg electron, more intense laser fields may essentially interact with inner electrons, which have high ionization potentials, thereby efficiently generating high-order harmonics. The process has the advantage of producing the very high harmonics, seen in intense laser-ion interactions, while maintaining the higher target densities of a neutral Rydberg (n{approx}10) gas.
Enhancement of naringenin solution concentration by solid dispersion in cellulose derivative matrices

Naringenin (Nar) is an important bioactive flavonoid with poor organic solubility and oral bioavailability. It is highly promising for treatment of conditions including diabetes, hyperlipidemia, and hepatitis C infection. Amorphous solid dispersion (ASD) of Nar is an appealing way to enhance its solubility, and carboxylated cellulose esters are attractive polymers for this purpose because of their ability to stabilize drugs against crystallization in both solid and solution phases, while restricting drug release to the pH of the small intestine (ca. 6.8). We demonstrate that ASDs of Nar can be formed using such carboxylated cellulose derivatives as cellulose acetate adipate propionate (CAAdP), carboxymethylcellulose acetate butyrate (CMCAB) and hydroxypropylmethylcellulose acetate succinate (HPMCAS). We compare Nar solution concentrations and release profiles from these cellulosic ASDs to those from pure crystalline Nar, and to Nar ASD in poly(vinylpyrrolidinone) (PVP). We show that all polymers in this study form ASDs with Nar, that the PVP ASDs release Nar at both gastric (1.2) and small intestine (6.8) pH, and that the cellulosic polymers release Nar selectively at neutral pH. Solution concentrations of Nar are significantly enhanced from these ASDs. These preliminary studies indicate that HPMCAS, CAAdP, and CMCAB are practical ASD polymers for Nar due to their ability to generate and stabilize high solution concentrations, and their pH-triggered drug release.
Command of an upper extremity FES system using a simple set of commands

The purpose of this project is to develop a method of providing a complete set of movement commands to an upper extremity neuroprosthesis when the number of command signals available is fewer than required by the mechanical system. The functional relevance of the developed command interface will be tested in a virtual reality environment, where users-able bodied and paralyzed-will use a limited number of commands to control a simulated neuroprosthesis capable of executing a set of important daily activities that require coordinated motion of a larger number of mechanical degrees of freedom.
In situ measurement of the aerosol size distribution in stratospheric solid rocket motor exhaust plumes

The concentration and size distribution of aerosol in the stratospheric exhaust plumes of two Space Shuttle rockets and one Titan IV rocket were measured using a two component aerosol sampling system carried aboard a WB-57F aircraft. Aerosol size distribution in the 0.01 µm to 4 µm diameter size range was measured using a two component sampling system. The measured distributions display a trimodal form with modes near 0.005 µm, 0.09 µm, and 2.03 µm and are used to infer the relative mass fractionation among the three modes. While the smallest mode has been estimated to contain as much as 10% of the total mass of SRM exhaust alumina, we find show that the smallest mode contains less than 0.05% of the alumina mass. This fraction is so small so as to significantly reduce the likelihood that heterogeneous reactions on the SRM alumina surfaces could produce a significant global impact on stratospheric chemistry.
ATP RELEASE MEDIATES OXYGEN INDUCED PULMONARY VASODILATION IN FETAL LAMBS. † 2031

The pulmonary vascular resistance (PVR) undergoes a dramatic decrease at birth to facilitate gas exchange by the lung in postnatal life. Oxygen is the most important stimulus that causes this pulmonary vasodilation. We proposed the hypothesis that exposure to O2 causes an increase in oxidative phosphorylation and ATP synthesis in pulmonary vascular endothelial cells and/or red cells. Increased release of this ATP into plasma then mediates the pulmonary vasodilation caused by O2. We previously reported that ATP causes pulmonary vasodilation in fetal lambs by stimulating the P2y purinergic receptor on the endothelial cells. The objectives of this study were to investigate the effects of 2,4 dinitrophenol (DNP), an uncoupler of oxidative phosphorylation, on (1) plasma ATP levels in pulmonary artery during O2 exposure and (2) changes in PVR caused by O2 exposure. We studied three fetal lambs that had catheters inserted in left pulmonary artery(LPA), aorta and right and left atria and a flow transducer around the LPA. Control studies were done by giving the pregnant ewe 100% O2 resulting in a 6±3 torr increase in fetal PaO2. Exposure to O2 was repeated after giving 1 mg of DNP, into the LPA over ten min. Data are shown as mean±SD. * P<0.05 from baseline (BL), # from control and $ from 10 min O2. PAP & SAP = pulmonary and systemic pressures. The increase in plasma ATP levels and LPA flow and decrease in PVR caused by O2 was attenuated by DNP. These preliminary data indicate that release of ATP mediates O2 induced pulmonary vasodilation in fetal lamb.Table
Plasma edge model for tokamaks

Abstract The discharge characteristics in fusion experiments, particularly tokamaks, are often determined by the coupling between the core plasma and the region between the limiter and the vacuum wall. A zero dimensional scrape-off model is developed which incorporates the essential atomic physics and plasma/wall interactions. This model is coupled to a one dimensional radial transport code for the analysis of tokamak discharges. It is demonstrated that the discharge characteristics predicted can be substantially altered by the inclusion of such a model.
Homage to Norman Borlaug

It is a great honor to replace Norman Borlaug on the advisory board of The International Journal of Environmental Studies. Although Norman and I only met once briefly, our paths have crossed in the...
The integration of knowledge and experimentation strategies in understanding a physical system

This study investigated how people integrate different kinds of knowledge in coming to understand the functions of components of a physical system. Twenty-three undergraduates worked on a hypothesis-testing task in which they constructed test circuits to decide the identity of electrical components hidden inside boxes. The students' problem-solving was driven by qualitative causal models that included ideas about cause and effect, task demands, and functions of circuits and circuit components. There was a hierarchy of four causal models, with higher levels representing increasing understanding and supporting increasingly successful problem solution. These causal models were associated with characteristic experimentation strategies, including strategies for generating evidence, interpreting evidence, and managing memory requirements. Some of these strategies followed directly from the causal model a student held, whereas others appeared to be more general. The level of understanding a student eventually attained about this physical system was a function of both domain knowledge and proficiency in experimentation strategies. Language: en
Congruent Pattern of Accessibility within the Pore of a Voltage-Gated Na+ Channel

Voltage-gated ion channels open a gate in response to membrane depolarization which allows ions to pass through the transmembrane pore of the channel. MTSET accessibility studies within the Shaker potassium channel revealed that K+ permeation is controlled by an intracellular gate, whereas Cd2+ and Ag+ accessibility measurements in the cyclic nucleotide-gated channel suggests that this process occurs at the selectivity filter. Modification data of cysteine residues introduced into the DIV S6 of a fast-inactivation removed voltage-gated sodium channel (VGSC) by MTSET indicate that sodium channel gating is also regulated by an intracellular gate. However, unlike the Shaker potassium channel, VGSCs are not composed of four identical subunits. Despite sequence similarity between each S6 helix, the multi-domain nature of VGSCs implies that there may be asymmetry within the pore that may have consequences in regard to channel gating. Thus, we sought to determine if analogous positions within the S6 helices of a VGSC act together to form an intracellular gate which occludes the pore while channels are closed. We scanned the MTSET accessibility of substituted cysteines in the pore lining helices of the first three domains (DI-DIII) in the rat skeletal muscle sodium channel. The modification data at these sites, selected on the basis of sequence alignment and MTSET accessibility data of DIV-S6, confirms that DII and DIII follow the same pattern of accessibility as that of DIV; however, the extent of block is quite varied across each domain. Along with DI accessibility data, these findings will be discussed in the context of pore gating in related voltage-gated ion channels.
Performance Characterization of BLAST for the Grid

BLAST is a commonly used bioinformatics application for performing query searches and analysis of biological data. As the amount of search data increases so does job search times. As means of reducing job turnaround times, scientists are resorting to new technologies such as grid computing to obtain needed computational and storage resources. Inherent with advent of new technologies, are additional complexities that arise, forcing scientists to deal with them. Grid computing exemplifies dynamic and transient state of heterogeneous resources that become a major obstacle in realizing user-desired levels of service. Many users do not realize that techniques applied in more traditional cluster environments do not simply transition into grid environment. This paper analyzes resource and application dependencies for BLAST in terms of job parameters that result in performance tradeoffs. We present a set of examples showing performance variability and point out a set of guidelines, which lead to establishing job performance tradeoffs.
Neuroticism, extroversion, and response to stress

Abstract The study evaluated the role of dispositional determinants in the mediation of response to stress. Thirty-five undergraduate females were assigned to one of four groups according to scores on the neuroticism and extroversion scales of the Eysenck Personality Inventory. The Induced Affect research paradigm was adapted as a stress analog procedure and, following a baseline phase, subjects were run in alternating relaxation and arousal phases. Both univariate and multivariate analyses were completed. Neurotic introverts tended to label IA generated arousal as fear whereas neurotic extroverts tended to label arousal as anger.
Integrating “depth first” and “breadth first” models of computing curricula

Traditional undergraduate Computer Science curricula have been increasingly challenged on a host of grounds: undergraduate computing education is attracting fewer majors, is not producing graduates who satisfy the needs of either graduate programs or business and industry, and is not effectively responding to the increasing needs for computing education among the larger student population. In the face of such challenges, there has been a recent movement to restructure undergraduate computing curricula.At Georgia Tech we have design (AY 91-92) and implemented (AY92-93) a new computing curriculum that features a radical restructuring of subject matter. During the design and implementation process, we paid close and critical attention to the particulars of both the ACM recommendations and reports from our colleagues at other institutions who had already gained some experience with “Breadth First” approaches. We have conclude that curriculum modernization should integrate key aspects of both “Depth First” and “Breadth First” approaches. Our new curriculum is an example of such integration. We present data (measures of student performance and of student and faculty opinion) that confirm that our approach is viable, and we now believe that it can be a useful model for others. In this paper, we outline the structure of our integrated curriculum and report on key facets of our experience with it.
Respiratory Disease Caused by Corynebacterium pseudotuberculosis

Corynebacterium pseudotuberculosis is a common cause of external abscesses in horses. Approximately 8% of affected horses develop internal infection, which is associated with increased mortality and expense. Respiratory disease caused by C. pseudotuberculosis occurs in approximately 40% of horses that develop internal C. pseudotuberculosis infection. The lower respiratory tract may be the only organ system affected and infection can manifest as pneumonia or pleuropneumonia. Approximately half of the horses that develop C. pseudotuberculosis lower respiratory tract infection have concurrent abdominal organ involvement. The liver is the site most commonly affected, although renal and splenic involvement also occurs. Abdominal ultrasound is an important diagnostic technique to specifically identify affected abdominal organs. With early diagnosis, a high proportion of horses with internal C. pseudotuberculosis infection respond well to long-term antimicrobial therapy; however, pregnant mares are at risk for fetal loss.
Effects of Noise on Modal Parameters Identified by the Eigensystem Realization Algorithm

The basic concept of the Eigensystem Realization Algorithm for modal parameter identification and model reduction is extended to minimize the distortion of the identified parameters caused by noise. The mathematical foundation for the properties of accuracy indicators, such as the singular values of the data matrix and modal amplitude coherence, is provided, based on knowledge of the noise characteristics. These indicators quantitatively discriminate noise from system information and are used to reduce the realized system model to a better approximation of the true model. Monte Carlo Simulations are included to support the analytical studies.
A Ca2+-inhibited non-selective cation conductance contributes to pacemaker currents in mouse interstitial cell of Cajal

Interstitial cells of Cajal (ICC) provide pacemaker activity in some smooth muscles. The nature of the pacemaker conductance is unclear, but studies suggest that pacemaker activity is due to a voltage-independent, Ca(2+)-regulated, non-selective cation conductance. We investigated Ca(2+)-regulated conductances in murine intestinal ICC and found that reducing cytoplasmic Ca(2+) activates whole-cell inward currents and single-channel currents. Both the whole-cell currents and single-channel currents reversed at 0 mV when the equilibrium potentials of all ions present were far from 0 mV. Recordings from on-cell patches revealed oscillations in unitary currents at the frequency of pacemaker currents in ICC. Voltage-clamping cells to -60 mV did not change the oscillatory activity of channels in on-cell patches. Depolarizing cells with high external K(+) caused loss of resolvable single-channel currents, but the oscillatory single-channel currents were restored when the patches were stepped to negative potentials. Unitary currents were also resolved in excised patches. The single-channel conductance was 13 pS, and currents reversed at 0 mV. The channels responsible were strongly activated by 10(-7) M Ca(2+), and 10(-6) M Ca(2+) reduced activity. The 13 pS channels were strongly activated by the calmodulin inhibitors calmidazolium and W-7 in on-cell and excised patches. Calmidazolium and W-7 also activated a persistent inward current under whole-cell conditions. Murine ICC express Ca(2+)-inhibited, non-selective cation channels that are periodically activated at the same frequency as pacemaker currents. This conductance may contribute to the pacemaker current and generation of electrical slow waves in GI muscles.
The significance of “Lord Rochester's monkey’

(1997). The significance of “Lord Rochester's monkey’. Studia Neophilologica: Vol. 69, No. 1, pp. 11-20.
Exact Solution of the Problem of the Entropy of Two-Dimensional Ice

At low temperatures ice has a residual entropy caused, presumably, by an indeterminacy of the crystal structure. The oxygen atoms constitute a periodic crystal lattice that is hydrogen bonded. The hydrogen atoms are not at the centers of the bonds, however, so that there are two possible states for each bond corresponding to the two positions of the hydrogen atom relative to the bond midpoint. Nevertheless, not all bond configurations are allowed, for there is a constraint called the “ice condition” such that for the four bonds emanating from each oxygen atom, exactly two of the bonds must have the hydrogen atoms close to the oxygen atom.
Effect of interphase modulus and cohesive energy on the critical aspect ratio in short-fibre composites

The effect of interphase modulus and cohesive energy on critical fibre length in short-fibre reinforced brittle composites has been investigated employing computer simulation. The simulation consists of a two-dimensional computer model based upon a discrete network of grid points. Failure is defined in terms of an energy criterion, where the energy is calculated on the basis of a two- and three-body interaction between the grid points. Simulation results show that for a whisker-type fibre, a thick interphase (i.e. Ai>Af where A represents the cross sectional area) with an elastic modulus less than that of the matrix in combination with an increased interphase toughness greatly reduce the critical aspect ratio, for both metal-matrix and ceramic-reinforced brittle polymer composites. The results also show a variation in the failure mode from tensile failure in the matrix to tensile and shear failure in the interphase as a function of the fibre-interphase modulus ratio. In particular, a significant increase in the load transfer efficiency in metal-matrix composites is found, for an interphase modulus Ei less than the matrix modulus Em. Better load transfer properties in metal-matrix composites cause the yield point to occur at higher values of applied strain, and hence may significantly increase the toughness (area under the stress-strain curve) for certain metal-matrix composites. The computer results are compared with the predictions of Cox's shear-lag theory as well as with a new theoretical development presented in this work. The new theory is found to provide a better description of the fibre and matrix stress distribution.
Reflections—In Praise of Consilience

AbstractConsilience refers to the linking together of principles from different disciplines to form new constructs. How important has consilience been in bringing new ideas to the management of nat...
An Interview with John V. Murra

lIi,i)'Wlllie Americall Historical Rer.;ierc (;4 (4i, 19S4, 6:J.1~65,3 An Interview with John V. Murra Introduction by JOHN HOWLAND ROWE Murra is an anthropologist who has devoted much of his professional career to studying the historical ethnology of the Incas and other Andean peoples of Ecuador, Peru, and Bolivia, using historical sources and working by historical methods, In the course of this work, he has edited a number of documents of the greatest importance and interest to historians, done a substantial amount of archival research, and worked harder than anyone else to bring histo­ rians and anthropologists together on three continents and to keep them talking to 01H' another. What has sparked his archival research is his con­ viction that in order to learn more about Andean historical ethnology, we need to turn up new sources. He has always had a special interest in eco­ nomic problems. What Murra would like to do is find out how the Inca state, or another Andean polity, worked in the years immediately preced­ ing 1;;32, particularly in the economic realm, He has depended on histor­ ical documents !()r this endeavor. I have referred to what he does as his­ torical ethnology, His vertical archipelago hypothesis has stimulated research ancl discussion among scholars in terested in the Andes from Ecuador to Bolivia, In 1963 MuITa received a major grant from the National Science Foun­ dation for a three-year project to provide anthropological context for the 1;;62 visita of Huanuco, The idea was to recruit a team of archaeologists, ethnographers, an ethnobotanist, and other specialists to do research in the area covered by the visita. As Murra said to me, previous area study projects had developed out of the interest of an archaeologist or an eth­ nographer in a particular area, and then a search was made for historical documents rclating to the area. Because of the spotty preservation of his­ torical documents, it usually turned out that there were few documents availahle f()r the area chosen. The II uanuco visita provided an oppor­ tunity, possibly unique in Peru, to organize an area research project in which the historical documentation, or at any rate the part of it that J OHN ' Professor of Anthropology, University of California, Berkelev.
Effects of catalyst particle size on multiple steady states

Carbon monoxide oxidation experiments were carried out over Pt-alumina catalyst particles of various sizes. The width of the conversion-temperature hysteresis loop goes through a maximum as the degree of intrapellet diffusion resistances (i.e., catalyst particle size) is varied. No hysteresis was observed over finely powdered catalysts. The above observations are in agreement with the qualitative predictions of diffusion-reaction theory, and provide further evidence to suggest that the steady-state multiplicities observed here were caused by the interactions between reaction and intrapellet diffusion resistances. The hysteresis loop was found to shift along the temperature axis as the pellet size was varied. The hysteresis occurred at the lowest temperature when catalyst particles of an intermediate size were used. Both larger and smaller particles showed multiplicity at higher temperatures. This observation is also consistent with diffusion-reaction theory.
Photorefractive Properties of Undoped and Doped Single Crystal SBN:60

We present the results of our theoretical and experimental studies of the photorefrac-tive effect in single crystal SBN:60, SBN:Ce, and SBN:Fe. Specifically, the two-beam coupling coefficients, response times and absorption coefficients of these materials are given.
The effect of length and diameter on the resistivity of bromine intercalated graphite fibers

The resistivity of bromine intercalated graphite fibers has been shown to vary with both the diameter and the length of the fibers. This is due to bromine depletion from the fiber surface. Model calculations assuming a 1.0 micron bromine depletion zone for P-100, and 3.0 microns for vapor-grown graphite fibers fit the respective diameter dependence of their resistivities quite well. Length dependence data imply a bromine depletion zone along the length of P-100 fibers which is also a few microns, but that of vapor grown fibers appears to be as large as 300 microns. Despite these values, microfilaments, which are much smaller than the expected depletion zones, do form residual bromine intercalation compounds with resistivities about one-half of their pristine value.
Measurement of the bubble nucleation temperature of water on a pulse-heated thin platinum film supported by a membrane using a low-noise bridge circuit

Abstract This study describes the performance of stress-minimized platinum (Pt) films supported by thin membranes (200 nm thick) to promote bubble nucleation of water near its theoretical superheat limit. The membrane configurations consist of Pt films deposited on 200 nm thick SiN films over bulk Si, with membranes being formed by etching Si from the back side of the films. Results are compared with more conventional Pt films supported by SiO2 and Si substrates. The average metal temperature is monitored by a bridge circuit with capacitive and inductive filtering to reduce noise in the output signal. Voltage pulses with durations ranging between 0.5 and 10 μs are imposed on the bridge to electrically heat the Pt film. The paper includes discussion of fabrication of the films, their treatment prior to using them as temperature sensors, the bridge circuit design for monitoring the change in electrical resistance during the power pulse, the calibration process of the films, and results of the bubble nucleation temperatures for the range of pulse durations examined. The results show that significantly less power is needed to trigger bubble nucleation on a membrane-supported platinum film compared to a platinum film on a bulk Si substrate. The nucleation temperatures which were closest to the theoretical limit of water were realized at heating rates of nearly 109 C/s. The potential for employing back-side etched devices is suggested for fundamental studies of phase transitions of highly superheated liquids and in applications where bubble nucleation is an important process such as for ink-jet printers and microscale bubble pump concepts.
The PI3K/Akt Pathway Contributes to Arenavirus Budding

Several arenaviruses, chiefly Lassa virus (LASV), cause hemorrhagic fever (HF) disease in humans and pose a significant public health concern in regions where they are endemic. On the other hand, evidence indicates that the globally distributed prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is a neglected human pathogen. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway participates in many cellular processes, including cell survival and differentiation, and also has been shown to play important roles in different steps of the life cycles of a variety of viruses. Here we report that the inhibition of the PI3K/Akt pathway inhibited budding and to a lesser extent RNA synthesis, but not cell entry, of LCMV. Accordingly, BEZ-235, a PI3K inhibitor currently in cancer clinical trials, inhibited LCMV multiplication in cultured cells. These findings, together with those previously reported for Junin virus (JUNV), indicate that targeting the PI3K/Akt pathway could represent a novel antiviral strategy to combat human-pathogenic arenaviruses.
Electrochemical studies of vanadium-riboflavin interactions in dimethyl sulfoxide

Abstract The electrochemistry and complexation of VO(ClO 4 ) 2 , VCl 3 , and VOF 3 with singly-reduced riboflavin have been studied by cyclic voltammetry and controlled-potential coulometry in dimethyl sulfoxide at a platinum electrode. The UV, visible, and near-IR spectra of solutions of these species have also been examined. Vanadium(IV) forms the complex VO(Rib) 2 (Rib − = singly reduced riboflavin) which is reduced to VO(Rib) 2− 2 at −0.74 V vs. SCE. VO(Rib) 2 is oxidized at −0.15 V producing free VO 2+ and neutral riboflavin. Reduced riboflavin forms a complex with VCl 3 having an oxidation potential of −0.12 V, which is similar to that for the vanadium(IV) complex. A mixture of reduced riboflavin and VOF 3 results in the spontaneous reduction of the metal and oxidation of the riboflavin anion to neutral riboflavin.
Chemical shifts and three-dimensional protein structures.

During the past three years it has become possible to compute ab initio the 13C, 15N and 19F NMR chemical shifts of many sites in native proteins. Chemical shifts are beginning to become a useful supplement to more established methods of solution structure determination, and may find utility in solid-state analysis as well. From 13C NMR, information on ϕ, Ψ and χ torsions can be obtained, permitting both assignment verification, and structure refinement and prediction. For 15N, both torsional and hydrogen-bonding effects are important, while for 19F, chemical shifts are primarily indicators of the local charge field. Chemical shift calculations are still slow, but shielding hypersurfaces — the shift as a function of the dihedral angles that define the molecular conformation — are becoming accessible. Over the next few years, theoretical and computer hardware improvements will enable more routine use of chemical shifts in structural studies, including the study of metal-ligand interactions, the analysis of drug and substrate binding and catalysis, the study of folding/unfolding pathways, as well as the characterization of conformational substates. Rather than simply being a necessary prerequisite for multidimensional NMR, chemical shifts and chemical shift non-equivalence due to folding are now beginning to be useful for structural characterization.
Exact forms of the unrestricted Gibbs-Duhem equation

Abstract The exact forms of the Gibbs-Duhen equation in terms of fugacities and activity coefficients, applicable to any multicomponent phase, are developed in a straightforward manner. Reduction to restricted equations valid for constant temperature, constant pressure, or constant composition becomes a simple matter of dropping terms.
Laboratory measures of aggressive responding in male parolees with violent and nonviolent histories

Males on parole were recruited into a study to determine the external validity of the ©Point Subtraction Aggression Paradigm, a laboratory procedure for measuring human aggressive responding. Subjects were assigned to either a violent or nonviolent group based on their criminal record and the Brown History of Violence Questionnaire. Subjects participated in six 25-min sessions and completed a series of questionnaires. During the laboratory sessions subjects were given two response options: 1) Pressing button A to accumulate points exchangeable for money, and 2) pressing button B which ostensibly subtracted points from another fictitious person. Responding on button B was defined as aggressive since it resulted in the ostensible delivery of an aversive stimulus to another person. Results indicated that the subjects in the violent group emitted significantly more aggressive responses than subjects in the nonviolent group. The two groups also differed on psychometric measures of aggression. This study provides external validity for this laboratory measurement of human aggressive responding, even among males with very similar backgrounds. © 1996 Wiley-Liss, Inc.
Pharmacologic Management of Feline Hyperthyroidism

Radioiodine is considered the treatment of choice for hyperthyroidism, but in some situations, methimazole therapy is preferred, such as in cats with preexisting renal insufficiency. Unfavorable outcomes from methimazole are usually attributable to side effects, such as gastrointestinal upset, facial excoriation, thrombocytopenia, neutropenia, or liver enzyme elevations. Because restoration of euthyroidism can lead to a drop in glomerular filtration rate, all cats treated with methimazole should be monitored with blood urea nitrogen and creatinine levels in addition to serum thyroxine (T 4 ) and a complete blood cell count. Transdermal methimazole is associated with fewer gastrointestinal side effects and can be used in cats with simple vomiting or inappetence from oral methimazole. Hypertension may not resolve immediately when serum T 4 is normalized, and moderate to severe hypertension should be treated concurrently with atenolol, amlodipine, or an angiotensin-converting enzyme inhibitor.
Gabor wavelet transform and application to problems in early vision

Some of the work on the use of Gabor wavelets, a nonorthogonal family of functions, in the analysis of image data is reviewed. Applications to low-level vision problems such as boundary detection, feature detection and localization, and shape recognition are illustrated. A brief introduction to the Gabor wavelet transformation is included. >
Frequency Modulation between Low- and High-Frequency Components of the Heart Rate Variability Spectrum May Indicate Sympathetic-Parasympathetic Nonlinear Interactions

Interactions among physiological mechanisms are abundant in biomedical signals, and they may exist to maintain efficient homeostasis. For example, sympathetic and parasympathetic neural activities interact to either elevate or depress the heart rate, to maintain homeostasis. There has been considerable effort devoted to developing algorithms that can detect interactions between various physiological mechanisms. However, methods used to detect the presence of interactions between the sympathetic and parasympathetic nervous systems, to take one example, have had limited success. This may be because interactions in physiological systems are nonlinear and nonstationary. The goal of this work was to identify nonlinear interactions between the sympathetic and parasympathetic nervous systems in the form of frequency and amplitude modulations in human heart rate data. To this end, wavelet analysis was performed, followed by frequency analysis of the resultant wavelet decomposed signals in several frequency brackets we define as: very low frequency (f<0.04 Hz), low frequency (0.04-0.15 Hz) and high frequency (0.15-0.4 Hz). Our analysis suggests that the HF bracket is significantly modulated by the LF bracket in the heart rate data obtained in both supine and upright body positions. Furthermore, the strength of modulations is stronger in the upright than supine position, which is consistent with elevated sympathetic nervous activities in the upright position. However, there was no evidence of amplitude modulation among these frequencies.
Instituting Software Metrics in Small Organizations: A Practical Approach

Literature reports indicate that software companies with less than 50 employees may represent up to 85% of the software organizations in several countries, including the United States. While the well-known process models may not be ideal in a relatively small setting, there is good news. Some of the large process models are being scaled down at the same time that new models are being developed specifically for smaller software organizations. The best news is that software process research metrics have been studied for years, and there are many options available for metrics utilization, either within or outside of a process improvement framework, regardless of the size of the setting. This work explores the challenges and benefits of using software metrics in small organizations, and outlines a practical framework, based on the Goal/Question/Metric paradigm, for instituting metrics programs in small organizations. This approach is motivated by industrial experiences reported in the literature and contributes to improving software development practices.
Progressive Education and Museum Education: Anna Billings Gallup and Louise Connolly.

AbstractMuseum education and progressive education both arose at the same historical period, approximately a century ago, and share not only a common history but also common features. Both emphasize pedagogy based on experience, interaction with objects, and inquiry. They also share a social vision of serving the entire society, including underserved audiences. The work of Anna Billings Gallup at The Brooklyn Children's Museum and Louise Connolly at the Newark Museum, exemplary museum educators during the early decades of the 20th century, illustrate the pedagogic and social aims of museum education in the progressive tradition. Their accomplishments can inspire us today.