cssi/SciSciGPT-SciSciNet huggingface dataset:
Social Presence Theory and Implications for Interaction and Collaborative Learning in Computer Conferences

This paper examines research on social presence theory and the implications for analyzing interaction, communication, collaborative learning, and the social context of computermediated communication (CMC). Two studies that examined whether social presence is largely an attribute of the communication medium or users’ perception of the medium are discussed. It can be concluded from the results that even though CMC is considered to be a medium that is low in social context cues, it can be perceived as interactive, active, interesting, and stimulating by conference participants. However, it is the kind of interactions that take place between the participants, and the sense of community that is created during the conference, that will impact participants’ perceptions of CMC as a “social” medium. Therefore, the impetus falls upon the moderators of computer conferences to create a sense of online community in order to promote interaction and collaborative learning.
Addressing fear of heights through virtual reality

Virtual reality is an area of computer science that provides a method for implementing three-dimensional, immersive, interactive worlds that can allow humans to experience situations that may be unlikely or impossible in the real world. The following research will examine the capabilities of virtual reality to fully immerse individuals within an artificial, three-dimensional environment. Individuals with a varying fear of heights will be immersed within an interactive three-dimensional environment. Furthermore, we will explore the effectiveness of the capability of virtual reality to treat psychological phobias, specifically acrophobia.
Processing of Exogenous Antigens for Presentation by Class I MHC Molecules Involves Post-Golgi Peptide Exchange Influenced by Peptide-MHC Complex Stability and Acidic pH

Vacuolar alternate class I MHC (MHC-I) Ag processing allows presentation of exogenous Ag by MHC-I molecules with binding of antigenic peptides to post-Golgi MHC-I molecules. We investigated the role of previously bound peptides and their dissociation in generating peptide-receptive MHC-I molecules. TAP1-knockout macrophages were incubated overnight with an initial exogenous peptide, producing a large cohort of peptide-K(b) complexes that could influence subsequent peptide dissociation/exchange. Initial incubation with FAPGNYPAL, KVVRFDKL, or RGYVYQGL enhanced rather than reduced subsequent binding and presentation of a readout peptide (SIINFEKL or FAPGNYPAL) to T cells. Thus, K(b) molecules may be stabilized by an initial (stabilizing) peptide, enhancing their ability to bind readout peptide and implicating peptide dissociation/exchange. In contrast, incubation with SIINFEKL as stabilizing peptide reduced presentation of readout peptide. SIINFEKL-K(b) complexes were more stable than other peptide-K(b) complexes, which may limit their contribution to peptide exchange. Stabilizing peptides (FAPGNYPAL, KVVRFDKL, or RGYVYQGL) enhanced alternate MHC-I processing of HB101.Crl-OVA (Escherichia coli expressing an OVA fusion protein), indicating that alternate MHC-I Ag processing involves peptide dissociation/exchange. Stabilizing peptide enhanced processing of HB101.Crl-OVA more than presentation of exogenous OVA peptide (SIINFEKL), suggesting that peptide dissociation/exchange may be enhanced in the acidic phagosomal processing environment. Furthermore, exposure of cells to acidic pH increased subsequent binding and presentation of readout peptide. Thus, peptide dissociation/exchange contributes to alternate MHC-I Ag processing and may be influenced by both stability of peptide-MHC-I complexes and pH.
Lysine, a Precursor of Carnitine in the Rat

Abstract Rats, fed a 20% gluten diet in which lysine is the limiting amino acid, exhibited a reduction of growth, anemia, and hypoproteinemia. Carnitine concentrations in skeletal muscle and heart of such lysine-deficient rats were significantly lower than in rats supplemented with 0.8% lysine, but were higher in the liver. Following intraperitoneal administration in lysine-deficient rats, radioactivity from dl-[6-14C]lysine, but not dl-[2-14C]lysine, was significantly incorporated into carnitine in the liver and skeletal muscle. These data thus establish a role for lysine in carnitine biosynthesis in the rat. A hypothetical scheme postulating transformations of lysine to yield carnitine is considered.
Quantum mean-field theory of collective dynamics and tunneling

A fundamental problem in quantum many-body theory is formulation of a microscopic theory of collective motion. For self-bound, saturating systems like finite nuclei described in the context of nonrelativistic quantum mechanics with static interactions, the essential problem is how to formulate a systematic quantal theory in which the relevant collective variables and their dynamics arise directly and naturally from the Hamiltonian and the system under consideration. Significant progress has been made recently in formulating the quantum many-body problem in terms of an expansion about solutions to time-dependent mean-field equations. The essential ideas, principal results, and illustrative examples are summarized. An exact expression for an observable of interest is written using a functional integral representation for the evolution operator, and tractable time-dependent mean field equations are obtained by application of the stationary-phase approximation (SPA) to the functional integral. Corrections to the lowest-order theory may be systematically enumerated. 6 figures. (RWR)
Properties of inelastic yielding zones generated by in-plane dynamic ruptures—I. Model description and basic results

We discuss results associated with 2-D numerical simulations of in-plane dynamic ruptures on a fault governed by slip-weakening and rate-and-state friction laws with off-fault yielding. The onset of yielding is determined by a Mohr–Coulomb-type criterion whereas the subsequent inelastic response is described by a Duvaut-Lions-type viscoplastic rheology. The study attempts to identify key parameters and conditions that control the spatial distribution and the intensity variation of off-fault yielding zones, the local orientation of the expected microfractures, and scaling relations or correlations among different quantities that can be used to characterize the yielding zones. In this paper, we present example results for crack and pulse ruptures, along with calculations of energy partition and characteristics of the simulated off-fault yielding zones. A companion follow-up paper provides a comprehensive parameter-space study of various examined features. In agreement with previous studies, the location and shape of the off-fault yielding zones depend strongly on the angle ψ of the background maximum compressive stress relative to the fault and the crack versus pulse mode of rupture. Following initial transients associated with nucleation of ruptures, the rate of various energy components (including off-fault dissipation) linearly increases with time for cracks, while approaching a constant level for pulse-like ruptures. The local angle to the fault of the expected microfractures is generally shallower and steeper than ψ in the compressional and extensional quadrants, respectively. The scalar seismic potency density decays logarithmically with increasing fault normal distance, with decay slope and maximum value that are influenced by the operating stress field.
Effects of Deccan volcanism on paleoenvironment and planktic foraminifera: A global survey

Deccan volcanism, one of Earth’s largest fl ood basalt provinces, erupted ~80% of its total volume (phase 2) during a relatively short time in the uppermost Maastrichtian paleomagnetic chron C29r and ended with the Cretaceous-Tertiary boundary mass extinction. Full biotic recovery in the marine realm was delayed at least 500 k.y. or until after the last Deccan eruptions in C29n (phase 3, 14% of the total Deccan volume). For over 30 yr, the mass extinction has been commonly attributed to the Chicxulub impact, and the delayed recovery remained an enigma. Here, we demonstrate that the two phases of Deccan volcanism can account for both the mass extinction and delayed marine recovery. In India, a direct correlation between Deccan eruptions (phase 2) and the mass extinction reveals that ~50% of the planktic foraminifer species gradually disappeared during volcanic eruptions prior to the fi rst of four lava megafl ows, reaching ~1500 km across India, and out to the Bay of Bengal. Another 50% disappeared after the fi rst megafl ow, and the mass extinction was complete with the last megafl ow. Throughout this interval, blooms of the disaster opportunist Guembelitria cretacea dominate shallow-marine assemblages in coeval intervals from India to the Tethys and the Atlantic Oceans to Texas. Similar high-stress environments dominated by blooms of Guembelitria and/or Globoconusa are observed correlative with Deccan volcanism phase 3 in the early Danian C29n, followed by full biotic recovery after volcanism ended. The mass extinction and high-stress conditions may be explained by the intense Deccan volcanism leading to rapid global warming and cooling in C29r and C29n, enhanced weathering, continental runoff, and ocean acidifi cation, resulting in a carbonate crisis in the marine environment. *jpunekar@princeton.edu Punekar, J., Mateo, P., and Keller, G., 2014, Effects of Deccan volcanism on paleoenvironment and planktic foraminifera: A global survey, in Keller, G., and Kerr, A.C., eds., Volcanism, Impacts, and Mass Extinctions: Causes and Effects: Geological Society of America Special Paper 505, p. 91–116, doi:10.1130/2014.2505(04). For permission to copy, contact editing@geosociety.org. © 2014 The Geological Society of America. All rights reserved. on August 25, 2014 specialpapers.gsapubs.org Downloaded from
Membrane glycoprotein transferases: time courses of activity changes in a synchronized cell population and enzyme activity half-lives in an asynchronous population.

Abstract The time course of activity changes of five membrane glycoprotein transferases: the glycoprotein:galactosyl, the fetuin:fucosyl, the PSM:fucosyl, the fetuin:N-acetylglucosaminyl, and the polypeptide: N-acetylgalactosaminyl was determined using defined acceptors and conditions in synchronized L5178Y cells. In addition, time course of activity changes of these transferases was determined for the endogenous acceptors present in the cell extract. Each of the membrane glycoprotein transferases was an S peak enzyme in the L5178Y cell. Activity with endogenous acceptors, in general, was constant throughout the cell cycle indicating that acceptor availability may, in part, control glycoprotein synthesis in vivo. Using an asynchronous population of L5178Y cells growing in 100 μg/ml of cycloheximide half-lives, stability times, and decay rates were determined for each of the membrane glycoprotein transferases. Each of the enzymes was relatively labile with short half-life and stability time and rapid decay rate.
Challenges of DEM: I. Competing bottlenecks in parallelization of gas–solid flows

Abstract An analysis is performed on the computational efficiency of performing gas–solid simulations based on the open source code MFIX, which was recently parallelized by domain decomposition method [1]. Although it is well known that the DEM portion for solving solid-phase flow dominates the computational load, the computational time is impacted both by the total number of particles in a simulation and the particle size, since the former determines the number of force calculations needed in one time step while the latter directly affects the size of the time step. One natural constraint in all simulations is the amount of time the user is willing to wait (wall-clock time) for a given simulation. Another constraint unique to the parallel run is the maximum number of processors available for one simulation, the upper bound of which is limited by the ratio of system dimension (width) to particle size. To evaluate the relative importance of these two bottlenecks, we simulate a number of pseudo-2D fluidized beds filled with particles of increasing size, and in which the static bed height is kept equal to the bed width. For a given particle size, the maximum feasible system dimension can be determined separately via both constraints mentioned above, thereby revealing the limiting computational bottleneck for a given particle size. It is shown that with increasing particle size, the limiting bottleneck switches from the amount of time we are willing to wait until the completion of a simulation to the maximum number of cores (processors) allowable in parallel simulations. The critical particle size at which the transition occurs is dependent on the values of two constraints. The analysis is thus helpful in selecting optimum system sizes for simulations based on tolerable waiting times and available parallel computing capabilities.
Optimal orientation of orthotropic materials using an energy based method

In this paper, an energy based method is proposed to determine the optimal orientation of orthotropic materials under static loading. Instead of assuming that the strain or stress fields are fixed with respect to orientational variables, the dependency of strain and stress fields on material orientation is explored by introducing an energy factor in the inclusion model. From the derivations, the strain based method and the stress based method can be recovered and their limitations are discussed. Numerical examples from these methods are presented and compared.
Fourier's Series

IN all expositions of Fourier's series which have come to my notice, it is expressly stated that the series can represent a discontinuous function.
Stoichiometric operation of a gas engine utilizing synthesis gas and EGR for NOx control

This paper presents the results from an internal research study conducted at the Southwest Research Institute (SwRI) on the effects of stoichiometric mixtures of natural gas and synthesis gas with exhaust gas recirculation (EGR) on engine performance and exhaust emissions. Constant load performance and emissions tests were conducted on a modified, single-cylinder, Caterpillar 1Y540 research engine at 11.0 bar (160 psi) bmep. Engine performance and emissions comparisons between natural gas with EGR, and natural gas with syngas and EGR are presented. In addition, the performance characteristics of the fuel reforming catalyst are presented. Results show that thermal efficiency increases with increasing EGR for both natural gas operation and natural gas with syngas operation at constant load. The use of syngas with natural gas extended the EGR tolerance by 44.4 percent on a mass basis compared to natural gas only, leading to a 77 percent reduction in raw NOx emissions over the lowest natural gas with EGR NOx emissions.
Cytogenetic studies and clinical implications in patients with Sézary syndrome.

Chromosome studies were carried out on 11 National Institutes of Health (N.I.H.) patients who had the diagnosis of Sezary syndrome. Heteroploidy, multiple markers including minute and ring chromosomes, and a lack of modality and clone formation, were the common chromosomal findings in this syndrome. Abundant spontaneous division of heteroploid cells in unstimulated peripheral blood cultures, a high percentage of heteroploid cells in stimulated culture, and finally, clone formation, are signs of a fulminant process and lead to the terminal phase of this disease. Early chemotherapeutic eradication of these heteroploid neoplastic cells would, therefore, be the treatment of choice in this disease.
On a Lagrangian proposed by Pecker, Roberts and Vigier

PECKER, Roberts and Vigier1 have proposed a phenomenological Lagrangian illustration to account for certain galactic redshift anomalies. They gave no quantitative estimate for the magnitude of A, apart from that it had to be much larger than the value (˜ a2) arising from the box diagram (Fig. le) in conventional quantum electrodynamics. They also proposed some experimental tests. Here I point out that a more direct test comes from the rate of the decay of orthopositronium into three photons. The present experimental data2, in fact, already limit the value of A to not more than about 10−1 α. Open image in new window
Carol Poore, The Bonds of Labor: German Journeys to the Working World, 1890–1990. Detroit: Wayne State University Press, 2000. 298 pp. $39.95 cloth.

Approaches to the history of class relations in Germany as elsewhere have changed dramatically over the past two decades or so. Historical class analysis, which once pointed to the clear significance of class as a social marker, a cultural and political identity, in short, as a force of history, has became dulled in the wake of the collapse of socialism, the decline of organized labor, and the intellectual challenges associated with postmodernism, feminism, and race theory. As one student remarked in a recent seminar on the history and historiography of class relations in Europe, class has become the unexamined third pillar of the race, class, gender triad. Historians do not deny the significance of class relations; it has just that figuring out how to theorize and document the history of class is much more complicated than it used to be.
Barrier dune systems: A reassessment

Abstract Barrier dunes are an important and natural part of most migrating barrier island systems. Sediment transfer across a barrier during storms by overwash or inlet dynamics results in temporary planation and/or truncation of the dune field. Post-storm recovery usually includes revegetation and subsequent dune building processes. Barrier dunes have not been shown to accelerate beach erosion, as reported by some scientists, rather they serve as a source of sediment. The effect of eroding dunes on swash processes during storm conditions requires more field and wave tank investigations. It appears that barrier dunes do not affect the long-term, geologic process of landward barrier migration with a rising sea level.
On friction and surface cracking during sliding of ice on ice

As a complement to earlier measurements on the friction of both granular fresh-water ice and S2 columnar salt-water ice, new experiments were performed on the friction of S2 columnar fresh-water ice sliding against itself at low velocities (5 × 10−7 to 5 × 10−1 m s−1) and at −10°C, using the same double-shear device as was used earlier. The results showed that under a given set of experimental conditions the kinetic coefficient of friction of S2 fresh-water ice compares favorably with that of the other two variants.The experiments also revealed friction-induced surface cracks and recrystallized grains.These deformation features are explained, respectively, in terms of fracture mechanics and an earlier model of dynamic recrystallization in ice.
Cannula-Assisted Flap Elevation (CAFE): A Novel Technique for Developing Flaps During Skin-Sparing Mastectomies

Background One of the most challenging procedures in breast surgery is the skin-sparing mastectomy (SSM). Various techniques and incisions have evolved that characterize this procedure; however, what is common in all of them is the smaller the incision, the more difficult it is to develop the skin flaps.
Magnetic properties of Ni in MgO; Ni+2 ions and magnetically ordered precipitates☆

Magnetic properties of Ni in MgO have been investigated, using a vibrating sample magnetometer. The samples were studied in two forms, as prepared with Ni ions in solution and chemically reduced with the Ni in microscopic precipitates. The initial materials exhibited paramagnetic behavior, having a Curie Law susceptibility with an effective moment per ion p = 3.08 ..mu../sub B/. (g = 2.18, with S = 1 for Ni/sup +2/ ions). Upon reduction, magnetic precipitates were formed, characterized by hysteresis and remanent moments. The observed low-temperature saturated moment per Ni of gS = 0.32 ..mu../sub B/, observed for several samples, as well as the temperature dependence of the saturation magnetization, indicates that the magnetic bahavior of the precipitates is rather different from bulk Ni.
REPRODUCTIVE BIOLOGY OF THE SESSILE GASTROPOD VERMICULARIA SPIRATA (CERITHIOIDEA: TURRITELLIDAE)

Cette etude decrit la biologie de la reproduction de V.S.: mode de reproduction, fecondation, type de developpement des larves
Links between dissociation and role play in a nonclinical sample of preschool children.

ABSTRACT Children's role play activities are included in symptom checklists of dissociative disorders, yet little is known about the potential relation between individual differences in role play and dissociative behaviors in normative development. This issue was examined in a study of 147 children aged 3 and 4 from a nonclinical population. Parents completed the Child Dissociative Checklist (CDC; F. W. Putnam, K. Helmers, & P. K. Trickett, 1993) and a questionnaire about their child's role play, fears, behavior problems, and dreams. Children were also interviewed about these same items. Dissociation was significantly related to parent report of fears, problem behaviors, and nightmares. These results are consistent with the view that CDC scores reflect some degree of difficulty in children's lives. Children who engaged in role play, particularly children with imaginary companions, scored higher on the CDC than other children. However, role play was not related to the measures of fears or problem behaviors...
MAC of sevoflurane in humans and the New Zealand white rabbit

The minimum alveolar concentration of sevoflurane necessary to prevent movement in 50 per cent of patients (MAC) was determined to be 2.05 per cent in 20 adult surgical patients. Because this value was higher than the only other experimentally determined human MAC value for sevoflurane (1.71 per cent), MAC was also determined in New Zealand white rabbits. Comparisons of the MAC ratios of sevoflurane to other volatile anaesthetics in both the human and the rabbit suggest that the human MAC value we obtained for sevoflurane is consistent with experimental determinations of MAC of other volatile anaesthetics in humans.
Detrital zircon evidence of Laurentian crustal dominance in the lower Pennsylvanian deposits of the Alleghanian clastic wedge in eastern North America

Abstract The late Paleozoic Alleghanian orogeny culminated with the continent–continent collision between Laurentia and Gondwana in the construction of the supercontinent Pangea. Within the Appalachian basin, the sedimentological record of the early stages of the continental collision is preserved as late Mississippian-age siltstones and mudstones that mark the end of carbonate production. An upward transition to coarse, quartz-rich, cratonward-prograding, fluvial deposits of Pennsylvanian age is cited to mark the initiation of continental collision and cratonward advancement of the tectonic load. Seven samples of early Pennsylvanian (early-middle Morrowan) sandstones and conglomerates from the Appalachian basin were collected along the orogen from eastern Pennsylvania to central Alabama for U–Pb dating of detrital zircons. All of the samples reveal a dominance of zircons with ages that can be attributed to crust-forming events in Laurentia. A small percentage of the detrital zircons have ages (530–680 Ma and 2000–2200 Ma) that correspond to the Pan-African/Brasiliano orogenic belts and Trans-Amazonian/Eburnian cratons typical of Gondwanan crust. Although recycling of pre-orogenic strata may disproportionately bias the detrital-zircon population toward ages of Laurentian affinity, the dominance of the Laurentian “signature” in the Appalachian basin along strike suggests that the early components of the Alleghanian orogen were composed mainly of recycled Laurentian crust. Detrital-zircon populations are not indicative of substantial incorporation of Gondwanan crust in the orogenic highlands. On the basis of the timing of dextral displacement along shear zones in the Appalachian hinterland, the early Pennsylvanian clastic deposits preserved in the Appalachian basin likely correspond to transpressional exhumation of the Laurentian margin, consistent with hypotheses of oblique collision between Gondwana and Laurentia in the late Paleozoic.
Primary-Grade Students' Knowledge and Thinking about Food Production and the Origins of Common Foods.

Abstract Individual interviews were conducted with 96 K-3 students, stratified according to grade level, achievement level, and gender. The students were asked to explain land-to-hand progressions involved in bringing several common foods to our tables, identify products derived from common farm animals, explain why a pound of cereal costs more than a pound of apples and a restaurant meal costs more than the same meal eaten at home, describe the steps involved in growing corn, explain why there are few farms in Alaska, identify inventions that have modernized farming, and explain why many fewer farmers per capita are needed today than in the past. The students knew more about the physical appearances of things than their underlying natures, and more about the uses of finished products than about the land-to-hand transformations involved in creating those products. Response sophistication was related much more closely to age (grade level) and personal experiences out of school than to achievement level or ...
Axial current conservation in the Bethe-Salpeter approach to the nuclear two-body problem

We investigate the structure of the one- and two-nucleon axial-current operators necessary for the partial conservation of the nuclear axial-current elastic matrix element in the one-boson-exchange approximation to the two-nucleon Bethe-Salpeter equation. We use three models for this purpose: (a) the linear sigma model, (b) the nonlinear sigma model, (c) a hybrid model, which is, roughly speaking, a linear combination of (a) and (b). We construct a partially conserved nuclear axial-current elastic matrix element in models (a) and (c) provided that the associated nuclear wave functions are solutions to the Bethe-Salpeter equation with a potential made of one-boson-exchange diagrams. In the nonlinear sigma model the nuclear one-body axial current is partially conserved by itself, without reference to the nuclear wave function, whereas the two-body axial current partial conservation is violated by terms of order 1/${\mathit{f}}_{\mathrm{\ensuremath{\pi}}}^{2}$. The complete axial current in models (a) and (c) and the one-body axial current in model (b) are applicable to the construction of the deuteron electroweak process amplitudes, for example. The divergence of the axial-current matrix element is proportional to the pion absorption nuclear matrix element, which leads to another potential application in the foundation of chiral perturbation theory for pion-two-nucleon processes. Consistency between the nuclear axial-currents and the underlying nuclear dynamics in models (a) and (c) is a new condition imposed by the partial conservation of the nuclear axial-current matrix element. We also examine conditions imposed on the form of the nucleon self-energy by the nucleon and meson axial Ward-Takahashi identities, as well as the approximations that satisfy the said conditions. We show that besides the first Born approximation, the so-called Hartree+random-phase approximation satisfies chiral Ward-Takahashi idenitities in models (a) and (c). \textcopyright{} 1996 The American Physical Society.
Decomposition- and nitrogen-mineralization patterns of Leucaena leucocephala and Cassia siamea mulch under tropical semiarid conditions in Kenya

In agroforestry systems, loppings from trees and shrubs are commonly used, often as mulch, as sources of nutrients for interplanted crops. Therefore, it is important to understand the rates of mulch decomposition. This paper reports the results of a study on the decomposition and nitrogen (N)-mineralization patterns of the leaves, small twigs, and mulch (leaves plus twigs) of Leucaena leucocephala and Cassia siamea in a field experiment in an Alfisol in semiarid Kenya. Plant materials contained in 5mm nylon bags were placed below or on the soil surface in an alleycropping system involving the two tree species, with maize (Zea mays L.) as the intercrop. For plant materials of both species (except Leucaena leaves), there were two phases of decompositions: an initial rapid phase and a slower second one; Leucaena leaves had only a single phase. When placed below the soil surface, the decomposition rates of both Leucaena and Cassia mulch were similar (about 12% week-1 in the first phase and 1% week-1 in the second phase). When placed on the soil surface, Leucaena mulch decomposed 1.3 times more rapidly than Cassia mulch in the first phase. The patterns of N release from the mulch of both species were similar to those of mass loss. In general, mulch-decomposition and N-release rates of both species were related more to their C:N ratios than to polyphenol contents; while C:N ratio predicted the rate of first (rapid) phase, the rate of the second (slow) phase appeared to be regulated by lignin and polyphenol contents.
Increasing participation and improving the quality of discussions in seventh-grade social studies classes.

Abstract An experiment was conducted to evaluate procedures to improve classroom discussions in seventh-grade social studies classes. An increased number of students participated in discussions when rules were stated for discussions, students were praised for their contributions, the teacher restated or paraphrased students' contributions aloud or on the blackboard, the teacher planned an outline of discussion questions, student contributions to discussions were recorded and were used to determine part of the students' grades for the class, and discussion grades were publicly posted. The second part of the study focused on procedures designed to improve quality of classroom discussions. Students were taught to participate in discussions by providing reasons for their statements, comparisons between different points, or examples supporting their statements. As each type of contribution was taught, recorded, and counted toward part of the students' classroom grades, each type of contribution increased. Ratings of discussions by outside judges consisting of junior high school teachers, junior high school students, and persons experienced in conducting discussions, indicated that the training increased the overall quality of the discussions. Use of the quality training procedures, however, resulted in decreased levels of overall participation in discussion, a decrease that was reversed by the use of a group contingency for participation. Finally, the discussions after training seemed to be preferred by both the teacher and the students.
Extended Sugawara construction for the superalgebras SU(M+1||N+1). II. The third-order Casimir algebra.

The machinery developed in paper I is used to compute the operator-productalgebra (OPA) of an operator constructed from the third-order Casimir invariantof the superalgebra SU(/ital m//vert bar//ital n/). The vertex operator construction ofSU(/ital m//vert bar//ital n/)/sup (1)/ is used to find a realization of the OPA forlevel /ital k/=1 in terms of free bosonic fields only. It turns out that inmany respects the conformal structure of the affinized Lie superalgebraSU(/ital m//vert bar//ital n/)/sup (1)/ is similar to that of theKa/hacek c/-Moody algebra SU(/ital m//minus//ital n/)/sup (1)/. Anintermediate result suggests the occurrence of extended conformal symmetries in/ital bc/ systems, to which we will devote a separate discussion.
Jamaican political processes: A system in search of a paradigm

This paper critically examines the explanations for the remarkable stability in the Jamaican socio‐political system provided by conflict pluralist, charismatic authority, dependency and patron‐client approaches. A variation of the patron‐client approach involving three interrelated levels (one external and two internal) is proposed as an alternative conceptual framework. The usefulness of the approach is demonstrated in an analysis of the defeat of the Manley government in the 1980 elections. Attention is drawn to the dynamic interrelationship between internal and external forces, and it is suggested that electoral behaviour during the 1980 elections was largely dictated by existing patron‐client relations.
An RTX operon in hemolytic Moraxella bovis is absent from nonhemolytic strains

Pathogenic isolates of Moraxella bovis express a calcium-dependent transmembrane pore forming cytotoxin that is an RTX toxin encoded by mbxA. The DNA flanking mbxA was cloned and sequenced to determine if M. bovis contained a classical RTX operon. Open reading frames (ORFs) with deduced amino acid sequence homology to putative activation (RTX C) and transport (RTX B and D) proteins were identified and have been designated MbxC, MbxB, and MbxD, respectively. Thus, hemolytic M. bovis contains a typical RTX operon comprised of four genes arranged (5'-3') mbxCABD. In addition, the deduced amino acid sequences of DNA flanking mbxCABD revealed ORFs with amino acid sequence similarity to transposases (5'). At the 3' end of the mbx gene cluster, an ORF with homology to bacterial tolC genes was identified. Thus, as with the cya RTX operon of Bordetella pertussis, M. bovis appears to have a secretion accessory protein linked to RTX genes. Analysis of genomic DNA isolated from 5 nonhemolytic M. bovis strains by PCR and Southern blotting revealed the absence of mbxCABD. These strains did, however, amplify with primers specific for the 5' region flanking mbxC. M. bovis harbors a classical RTX operon that is absent in nonhemolytic strains.
Design of smart window based on electrochromic polymers: new derivatives of 3,4-alkylenedioxythiophene

The synthesis, characterization and polymerization of two new electrochromic (EC) monomers based on 3, 4-alkylenedioxythiophene are reported. One is 3, 4-bis-(2, 2, 2-trifluoro-ethoxy)-thiophene which contains electron withdrawing group. Another is 6, 6-dimethy-6, 7-dihydro-5H-4, 8-dioxa-2-thia-6-sila-azulene which contains an electron donating group. Primary experiment results show that the new monomers have potential to form EC materials with new colors after polymerization. Color mixing of two EC polymers with blue and red color was studied. The principle of subtractive color mixing for achieving new color EC materials is also demonstrated.
Bringing up Java

Java will be big time-even if Microsoft hijacks it. In any event, the computer industry has no choice but to adjust to the inevitability of Java. However, Java and Java technologies like JavaBeans and IIOP (the Internet version of CORBA for Java) are still works in progress. They are half-roasted and inadequate for the task facing developers. When Java and its supporting technologies mature, the computing industry will have created an entirely new species-the Java platform, but the Darwinian forces at work in the software business may vector this evolution down the wrong path. Unless the industry makes a conscious effort to fix Java, everyone will be stuck with millions of lines of low-level hodgepodge. Our best hope is for the entire industry to evolve Java by making appropriate enhancements that will overcome its gross inadequacies and missing facilities. Unless we do, the Java platform won't be safe for anyone. Thus, this article is a call-to-arms, a plea for help and a prescription for what to do about the "Java problem".
Influences of Ligand Environment on the Spectroscopic Properties and Disproportionation Reactivity of Copper−Nitrosyl Complexes

In studies of the chemistry of new copper−nitrosyl complexes supported by tris(3-(trifluoromethyl)-5-methylpyrazol-1-yl)hydroborate (TpCF3,CH3) and tris(3-mesitylpyrazol-1-yl)hydroborate (TpMs,H), significant effects of the scorpionate ligand substituents on the properties of the {CuNO}11 unit were found that have implications for environmental influences on similar species in biological and catalytic systems. The copper(I) complexes TpMs,HCu(THF) and TpCF3,CH3Cu(CH3CN) were structurally characterized by X-ray crystallography, and their respective CO and NO adducts were studied by FTIR, EPR, NMR, and/or UV−vis spectroscopies in solution. Both nitrosyl complexes disproportionate in the presence of excess NO to N2O and TpR,R‘Cu(NO2); an X-ray structure of the latter product supported by TpCF3,CH3 was determined. Unlike previously studied paramagnetic [CuNO]11 compounds that exhibit EPR signals with g < 2.0 and large ANO values at temperatures below ∼40 K (Ruggiero, C. E.; Carrier, S. M.; Antholine, W. E.; W...
Structural studies of graphite intercalation compounds

Electron diffraction through the c-face (layer planes) and scanning electron microscopy (SEM) on the a-face (perpendicular to the layer planes) have been used to study the intralayer crystal structure and the micro-structure of graphite and its intercalation compounds. With the electron diffraction technique, the intra-layer intercalate ordering and the associated order-disorder transformations have been studied in graphitealkali metals (K, Rb, Cs) and graphite-halogens Br2, IBr, ICl). Reported here is the first observation of order-disorder transformations in the graphite-halogen compounds. Direct evidence is given for the presence of intralayer intercalate ordering in even extremely dilute lamellar and residue compounds. Also presented here is a new a-face surface preparation technique, which involves mechanical polishing and back-sputtering. SEM observations of the a-faces reveal large microstructural differences between highly-oriented pyrolytic graphite, chemically-separated single-crystal graphite and mechanically-separated single-crystal graphite. Significant exfoliation along the c-direction occurs upon intercalation. Evidence is given for the preferential trapping of intercalate at defects in both lamellar and residue compounds.
UCP3: An Uncoupling Protein Homologue Expressed Preferentially and Abundantly in Skeletal Muscle and Brown Adipose Tissue

Uncoupling proteins (UCPs) are inner mitochondrial membrane transporters which dissipate the proton gradient, releasing stored energy as heat. UCP1 is expressed exclusively in brown adipocytes while UCP2 is expressed widely. We now report the molecular cloning of a third uncoupling protein homologue, designated UCP3. At the amino acid level, hUCP3 is 71% identical to hUCP2 and 57% identical to hUCP1. UCP3 is distinguished from UCP1 and UCP2 by its abundant and preferential expression in skeletal muscle in humans, and brown adipose tissue and skeletal muscle in rodents. Since skeletal muscle and brown adipose tissue are believed to be important sites for regulated energy expenditure in humans and rodents, respectively, UCP3 may be an important mediator of adaptive thermogenesis. Since UCP3 is minimally expressed in human heart and other critical organs, it is a promising target for anti-obesity drug development aimed at increasing thermogenesis.
Martensitic toughening of ceramics

Abstract Current knowledge of displacive phase transformations in non-metals (in particular, in ceramics) is reviewed. Using the tetragonal-to-monoclinic transformation in zirconia (ΔV = 4.9% at room temperature) as a model system, the factors controlling the metastability of confined particles are discussed, i.e. matrix constraint, chemical composition position and nucleation barrier to the transformation. The model for martensitic nucleation in ceramics is based on a localized soft mode mechanism at strain singularities or concentrations in faceted particles. Other potential transformation togerther alternative to zirconia have been identified. For the first time, preliminary mechanical toughness data using the new tougheners is briefly presented. Composites of 20wt.% BTb2O3 in 80 vol.% MgO causes a thresfold increase at 1400°C. Monoclinic (β) dicalcium silicate dispersed in calcium zirconate exhibits a fivefold increase in toughness. Other new materials including refractory sulfides are examined from the point of view of transformation toughening. The application of high pressures during processing makes it feasible to alter thermodynamic phase fields and to develop yet other new transformation-toughened composites.
The Personal and Interpersonal Significance of Menarche

Abstract The clinical and empirical literature on menarche is reviewed and a descriptive study of girls' expectations and reports of changes associated with menarche—including reorganization of body image, sexual identification, self-perception, and family and peer relations—is presented. Results indicate that menarche may have a positive personal significance insofar as it is associated with greater maturity, but this positive impact is overshadowed by a negative interpersonal significance as girls become increasingly self-conscious, embarrassed, and secretive. These results contribute to a normative data base regarding psychological correlates of menarche and indicate the need for developing new ways of helping girls balance their perceptions of the positive and negative correlates of menarche.
Stability analysis and application of Kalman filtering with irregularly sampled measurements

This paper analyzes the peak covariance stability properties of Kalman filtering for linear discrete-time systems with irregular time intervals for sampling of output measurements. Existing research on Kalman filtering with irregular sampling mostly builds on probabilistic description of sampling intermittence. In this work, we focus on the general case of irregular sampling without probabilistic assumptions. The obtained stability conditions show that the peak covariance stability is influenced by the eigenvalue distribution of the state matrix in the complex plane. The effectiveness of the analysis is illustrated via a simulation based study on ocean flow field estimation using submersible drogues that can measure position intermittently and acceleration incessantly.
Sampling subproblems of heterogeneous Max-Cut problems and approximation algorithms

Recent work in the analysis of randomized approximation algorithms for NP-hard optimization problems has involved approximating the solution to a problem by the solution of a related subproblem of constant size, where the subproblem is constructed by sampling elements of the original problem uniformly at random. In light of interest in problems with a heterogeneous structure, for which uniform sampling might be expected to yield suboptimal results, we investigate the use of nonuniform sampling probabilities. We develop and analyze an algorithm which uses a novel sampling method to obtain improved bounds for approximating the Max-Cut of a graph. In particular, we show that by judicious choice of sampling probabilities one can obtain error bounds that are superior to the ones obtained by uniform sampling, both for unweighted and weighted versions of Max-Cut. Of at least as much interest as the results we derive are the techniques we use. The first technique is a method to compute a compressed approximate decomposition of a matrix as the product of three smaller matrices, each of which has several appealing properties. The second technique is a method to approximate the feasibility or infeasibility of a large linear program by checking the feasibility or infeasibility of a nonuniformly randomly chosen subprogram of the original linear program. We expect that these and related techniques will prove fruitful for the future development of randomized approximation algorithms for problems whose input instances contain heterogeneities. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2008 A preliminary version of this paper with the same title appeared in the Proceedings of the 22nd Annual International Symposium on Theoretical Aspects of Computer Science, Lecture Notes in Computer Science 3404, pp. 57–68, 2005 [13].
The morality behind sustainability

The concepts of sustainable agriculture, organic agriculture, regenerative agriculture, and alternative agriculture are receiving increasing attention in the academic and popular literature on present trends and future directions of agriculture. Whatever the reasons for this interest, there nevertheless remain differences of opinion concerning what counts as a sustainable agriculture. One of the reasons for these differences is that the moral underpinnings of a policy of sustainability are not clear. By understanding the moral obligatoriness of sustainability, we can come to understand precisely what must be sustained, and by implication, how. This article discusses the arguments that can be advanced for sustaining anything and initially concludes that our obligations to future generations entail sustaining more than just sufficient food production or an adequate resource base. Indeed, a tradition of care and community must underlie whatever agricultural and resource strategies we are to develop under the rubric of sustainability. A consideration of the larger social and environmental system in which agriculture operates and the constraints this system places on agriculture forces us to recognize that sustainability has to do with larger institutional issues, including our ability to incorporate our common morality democratically into our institutions, practices, and technologies.
Eras III and IV: My Reflections

Richard Staelin is Edward and Rose Donnell Professor of Business Administration, The Fuqua School of Business, Duke University (email: rstaelin@duke.edu). The author acknowledges the helpful comments of Bill Boulding, Preyas Desai, and Joel Huber on a previous draft of this article. Wilkie and Moore (2003) divide up the historical development of marketing thought into four eras. The goal in this essay is to provide my perspective on the latter two eras, starting with the year-long program in 1959 sponsored by the Ford Foundation and ending with my current experiences with the globalization of the marketing profession. In the process, I hope to provide some useful insights into one of the major concerns that Wilkie and Moore raise—namely, that the field of marketing is becoming fragmented, and as a result, (1) knowledge is being lost, and (2) theoretical and methodological domains are taking precedence over the substantive domain.
Hypoxia and temporal aspects of hypothalamic self-stimulation

Six rats were trained to operantly control the duration of electrical stimulation to the posterior hypothalamus. The duration of the stimulus was equal to the duration of the lever deflection response. Under normoxic conditions (21% 02), increasing stimulus current levels yielded increasing response rates, decreasing response durations and decreasing inter-response times. Hypoxia (8% 02) did not affect response duration at any current level, but lengthened inter-response time. The magnitude of this effect was inversely related to current level. Results are interpreted as suggesting that hypoxia does not affect the neural response concurrent with electrical stimulation but affects the after-effects of stimulation.