bluuebunny/crossref_metadata_2025 huggingface dataset:
Rolling sphere problems on spaces of constant curvature
Authors: JURDJEVIC V. , ZIMMERMAN J.
Published: March 2008

The rolling sphere problem on Euclidean space consists of determining the path of minimal length traced by the point of contact of the oriented unit sphere$\mathbb{S}^{n}$as it rolls on$\mathbb{E}^{n}$without slipping between two points of$\mathbb{E}^{n}\times SO_{n+1}(\mathbb{R})$. This problem is extended to situations in which an oriented sphere$\mathbb{S}_{\rho}^{n}$of radius ρ rolls on a stationary sphere$\mathbb{S}_{\sigma}^{n}$and to the hyperbolic analogue in which the spheres$\mathbb{S}_{\rho}^{n}$and$\mathbb{S}_{\sigma}^{n}$are replaced by the hyperboloids$\mathbb{H}_{\rho}^{n}$and$\mathbb{H}_{\sigma}^{n}$respectively. The notion of “rolling” is defined in an isometric sense: the length of the path traced by the point of contact is measured by the Riemannian metric of the stationary manifold, and the orientation of the rolling object is measured by a matrix in its isometry group. These rolling problems are formulated as left invariant optimal control problems on Lie groups whose Hamiltonian extremal equations reveal two remarkable facts: on the level of Lie algebras the extremal equations of all these rolling problems are governed by a single set of equations, and the projections onto the stationary manifold of the extremal equations havingI4=0, whereI4is an integral of motion, coincide with the elastic curves on this manifold. The paper then outlines some explicit solutions based on the use of symmetries and the corresponding integrals of motion.
Characteristic elements, pairings and functional equations over the false Tate curve extension
Authors: ZÁBRÁDI GERGELY
Published: March 2008

We construct a pairing on the dual Selmer group over false Tate curve extensions of an elliptic curve with good ordinary reduction at a primep≥5. This gives a functional equation of the characteristic element which is compatible with the conjectural functional equation of thep-adicL-function. As an application we compute the characteristic elements of those modules – arising naturally in the Iwasawa-theory for elliptic curves over the false Tate curve extension – which have rank 1 over the subgroup of the Galois group fixing the cyclotomic extension of the ground field. We also show that the example of a non-principal reflexive left ideal of the Iwasawa algebra does not rule out the possibility that all torsion Iwasawa-modules are pseudo-isomorphic to the direct sum of quotients of the algebra by principal ideals.
Gravity Recovery and Climate Experiment (GRACE) alias error from ocean tides
Authors: Seo K. W. , Wilson C. R. , Han S. C. , Waliser D. E.
Published: March 2008

Gravity Recovery and Climate Experiment (GRACE) is able to observe interannual and longer‐period mass redistribution driven by climate changes. However, alias errors due to inaccurate ocean tide models may contaminate these signals. To quantify this problem, we estimate alias contamination due to expected errors in eight tidal constituents (Q1, O1, P1, K1, N2, M2, S2, and K2) for the period August 2002 to February 2006. Differences between GOT00.2 and TPXO6.2 tide models are used as estimates of tide model errors. The alias estimate is based on an approximate method employing least squares fits of spherical harmonics to potential differences between the two GRACE satellites. Results from this method are similar to previous estimates, confirming this is a useful and efficient way to study the alias problem. New findings are (1) the period of the M2 tide alias is about 140 d, much longer than the predicted period (13.5 d) because of monthly sampling of the 13.5‐d period; (2) there are two alias periods for K1 (one about 90 d and one longer than 7 years); and (3) the slow decay in the GRACE orbit causes tide component aliases to differ from pure frequencies as the orbit evolves. We also find that aliases can contaminate in both space and time and thus may affect estimates of mass changes over land. Finally, we compare the simulated S2 alias with the estimated S2 alias in GRACE data. They are similar, but our approximate method appears to overestimate alias error over high‐latitude oceans and along certain coastlines while underestimating error over low‐latitude oceans.
Seasonal variations of magnesium atoms in the mesosphere‐thermosphere
Authors: Correira J. , Aikin A. C. , Grebowsky J. M. , Pesnell W. D. , Burrows J. P.
Published: March 2008

UV radiances from the Global Ozone Monitoring Experiment (GOME) spectrometer on the ERS‐2 satellite are used to determine long‐term dayside temporal variations of the total vertical column density below 795 km of the meteoric metal species Mg and Mg+ in the upper atmosphere. The GOME instrument has the ability to observe the ground state transition lines of Mg I at 285.2 nm and resolve the Mg II at 280 nm. A retrieval algorithm has been developed to determine column densities and applied to the years 1996–1997. Results show the middle latitude dayside Mg+ peaks in total vertical content during the summer, while neutral Mg demonstrates a much more subtle maximum in summer. Dayside trends are opposite previous midlatitude nighttime lidar observations, with the exception of calcium. The Mg+/Mg ratio has a seasonal variation, reaching a maximum in the summer. The total content of Mg+ is twice that of neutral Mg.
A parametric model for ocean wave period from Ku band altimeter data
Authors: Mackay E. B. L. , Retzler C. H. , Challenor P. G. , Gommenginger C. P.
Published: March 2008

Using a large collocated data set of altimeter and buoy measurements, we examine the relationship between the altimeter Ku‐band measurements of significant wave height, Hs, backscatter coefficient, σ0, and the buoy wave period. This is used to derive an empirical altimeter wave period model for TOPEX, Poseidon, Jason‐1, ERS‐2, Envisat, and GEOSAT follow‐on. We show that there is a step change in the response of σ0 at around 13 dB and above this value σ0 is not related to wave period. The results are compared to algorithms proposed by two previous authors (Gommenginger et al., 2003; Quilfen et al., 2004) and examined in terms of absolute accuracy (RMS error), ability to replicate the joint distribution of wave height and period, and residual trends with various parameters. The new algorithm is shown to perform better than the previous algorithms in all metrics considered. Finally, we demonstrate that there is a limiting accuracy achievable for a function of the form f(Hs, σ0) and that our model comes close to this.
Mixed-mode oscillations in a homogeneous
p
H-oscillatory chemical reaction system
Authors: Bakeš Daniel , Schreiberová Lenka , Schreiber Igor , Hauser Marcus J. B.
Published: March 2008

We examine experimentally a chemical system in a flow-through stirred reactor, which is known to provide large-amplitude oscillations of the pH value. By systematic variation of the flow rate, we find that the system displays hysteresis between a steady state and oscillations, and more interestingly, a transition to chaos involving mixed-mode oscillations. The basic pattern of the measured pH in the mixed-mode regime includes a large-scale peak followed by a series of oscillations on a much smaller scale, which are usually highly irregular and of variable duration. The bifurcation diagram shows that chaos sets in via a period-doubling route observed on the large-amplitude scale, but simultaneously small-amplitude oscillations are involved. Beyond the apparent accumulation of period doubling bifurcations, a mixed-mode regime with irregular oscillations on both scales is observed, occasionally interrupted by windows of periodicity. As the flow rate is further increased, chaos turns into quasiperiodicity and later to a simple small-amplitude periodic regime. Dynamics of selected typical regimes were examined with the tools of nonlinear time-series analysis, which include phase space reconstruction of an attractor and calculation of the maximal Lyapunov exponent. The analysis points to deterministic chaos, which appears via a period doubling route from below and via a route involving quasiperiodicity from above, when the flow rate is varied.
The selection of mixed-mode oscillations in a Hodgkin-Huxley model with multiple timescales
Authors: Rubin Jonathan , Wechselberger Martin
Published: March 2008

In recent work [J. Rubin and M. Wechselberger, Biol. Cybern. 97, 5 (2007)], we explained the appearance of remarkably slow oscillations in the classical Hodgkin-Huxley (HH) equations, modified by scaling a time constant, using recently developed theory about mixed-mode oscillations (MMOs). This theory is only rigorously valid, however, for ε sufficiently small, where ε is a parameter that arises from nondimensionalization of the HH system. Here, we illustrate how the parameter regime over which MMOs exist, and the features of the MMO patterns within this regime, vary with respect to several key parameters in the nondimensionalized HH equations, including ε. Moreover, we explain our findings in terms of the effects that these parameters are expected to have on certain organizing structures within the corresponding flow, generalized from analysis done previously in the singular limit.
Stochastic phase dynamics and noise-induced mixed-mode oscillations in coupled oscillators
Authors: Yu Na , Kuske Rachel , Li Yue Xian
Published: March 2008

Synaptically coupled neurons show in-phase or antiphase synchrony depending on the chemical and dynamical nature of the synapse. Deterministic theory helps predict the phase differences between two phase-locked oscillators when the coupling is weak. In the presence of noise, however, deterministic theory faces difficulty when the coexistence of multiple stable oscillatory solutions occurs. We analyze the solution structure of two coupled neuronal oscillators for parameter values between a subcritical Hopf bifurcation point and a saddle node point of the periodic branch that bifurcates from the Hopf point, where a rich variety of coexisting solutions including asymmetric localized oscillations occurs. We construct these solutions via a multiscale analysis and explore the general bifurcation scenario using the λ−ω model. We show for both excitatory and inhibitory synapses that noise causes important changes in the phase and amplitude dynamics of such coupled neuronal oscillators when multiple oscillatory solutions coexist. Mixed-mode oscillations occur when distinct bistable solutions are randomly visited. The phase difference between the coupled oscillators in the localized solution, coexisting with in-phase or antiphase solutions, is clearly represented in the stochastic phase dynamics.
Return maps of folded nodes and folded saddle-nodes
Authors: Guckenheimer John
Published: March 2008

Folded nodes occur in generic slow-fast dynamical systems with two slow variables. Open regions of initial conditions flow into a folded node in an open set of such systems, so folded nodes are an important feature of generic slow-fast systems. Twisting and linking of trajectories in the vicinity of a folded node have been studied previously, but their consequences for global dynamical behavior have hardly been investigated. One manifestation of the twisting is as “mixed mode oscillations” observed in chemical and neural systems. This paper presents the first systematic numerical study of return maps for trajectories that flow through a region with a folded node. These return maps are approximated by rank-1 maps, and the local twisting of trajectories near a folded node gives rise to multiple turning points in the approximating one dimensional maps. A variant of the forced van der Pol system is used here to illustrate that folded nodes can be a “chaos-generating” mechanism. Folded saddle-nodes occur in generic one-parameter families of slow-fast dynamical systems with two slow variables. These bifurcations give birth to folded nodes. Numerical simulations demonstrate that return maps of systems that are close to a folded saddle-node can be even more complex than those of folded nodes that are far from folded saddles.
Comparison of explicit atom, united atom, and coarse-grained simulations of poly(methyl methacrylate)
Authors: Chen Chunxia , Depa Praveen , Maranas Janna K. , Garcia Sakai Victoria
Published: March 2008

We evaluate explicit atom, united atom, and coarse-grained force fields for molecular dynamics simulation of poly(methyl methacrylate) (PMMA) by comparison to structural and dynamic neutron scattering data. The coarse-grained force field is assigned based on output of the united atom simulation, for which we use an existing force field. The atomic structure of PMMA requires the use of two types of coarse-grained beads, one representing the backbone part of the repeat unit and the other representing the side group. The explicit atom description more closely resembles dynamic experimental data than the united atom description, although the latter provides a reasonable approximation. The coarse-grained description provides structural and dynamic properties in agreement with the united atom description on which it is based, while allowing extension of the time trajectory of the simulation.
A computational investigation of thermodynamics, structure, dynamics and solvation behavior in modified water models
Authors: Chatterjee Swaroop , Debenedetti Pablo G. , Stillinger Frank H. , Lynden-Bell Ruth M.
Published: March 2008

We investigate the properties of geometrically modified water models by performing molecular dynamics simulations of perturbations of the extended simple point charge (SPC/E) model of water over a wide range of temperatures at 1bar. The geometric modification consists of altering the H–O–H angle in SPC/E. The dipole moment is held constant by altering the O–H bond length, while the electrostatic charges are left unchanged. We find that a H–O–H angle of at least 100° is necessary for the appearance of density anomalies and of solubility extrema with respect to temperature for small apolar solutes. We observe the occurrence of two incompatible types of structural order in these models: Tetrahedral, with waterlike translational order for bent models with H–O–H angles in excess of 100°; and linear, with Lennard–Jones–like orientationally averaged translational order for smaller H–O–H angles. Increasing the H–O–H angle causes the density to increase, while at the same time shifting waterlike anomalies to progressively higher temperatures. For bent models with H–O–H angle greater than SPC/E’s, we observe arrest of translational motion at 300K (115°) and 330K (120°).
Error exponents in hypothesis testing for correlated states on a spin chain
Authors: Hiai Fumio , Mosonyi Milán , Ogawa Tomohiro
Published: March 2008

We study various error exponents in a binary hypothesis testing problem and extend recent results on the quantum Chernoff and Hoeffding bounds for product states to a setting when both the null hypothesis and the alternative hypothesis can be correlated states on a spin chain. Our results apply to states satisfying a certain factorization property; typical examples are the global Gibbs states of translation-invariant finite-range interactions as well as certain finitely correlated states.
Structural and spectroscopic properties of an aliphatic boronic acid studied by combination of experimental and theoretical methods
Authors: Cyrański Michał K. , Jezierska Aneta , Klimentowska Paulina , Panek Jarosław J. , Żukowska Grażyna Z. , Sporzyński Andrzej
Published: March 2008

Boronic acids have emerged as one of the most useful class of organoboron molecules, with application in synthesis, catalysis, analytical chemistry, supramolecular chemistry, biology, and medicine. In this study, the structural and spectroscopic properties of n-butylboronic acid were investigated using experimental and theoretical approaches. X-ray crystallography method provided structural information on the studied compound in the solid state. Infrared and Raman spectroscopy served as tools for the data collection on vibrational modes of the analyzed system. Car–Parrinello molecular dynamics simulations in solid state were carried out at 100 and 293K to investigate an environmental and temperature influence on molecular properties of the n-butylboronic acid. Analysis of interatomic distances of atoms involved in the intermolecular hydrogen bond was performed to study the proton motion in the crystal. Subsequently, Fourier transform of autocorrelation functions of atomic velocities and dipole moment was applied to study the vibrational properties of the compound. In addition, the inclusion of quantum nature of proton motion was performed for O–H stretching vibrational mode by application of the envelope method for intermolecular hydrogen-bonded system. The second part of the computational study consists of simulations performed in vacuo. Monomeric and dimeric forms of the n-butylboronic acid were investigated using density functional theory and Møller–Plesset second-order perturbation method. The basis set superposition error was estimated. Finally, atoms in molecules (AIM) theory was applied to study electron density topology and properties of the intermolecular hydrogen bond. Successful reproduction of the molecular properties of the n-butylboronic acid by computational methodologies, presented in the manuscript, indicates the way for future studies of large boron-containing organic systems of importance in biology or materials science.
Bifurcation analysis of a normal form for excitable media: Are stable dynamical alternans on a ring possible?
Authors: Gottwald Georg A.
Published: March 2008

We present a bifurcation analysis of a normal form for traveling waves in one-dimensional excitable media. The normal form that has been recently proposed on phenomenological grounds is given in the form of a differential delay equation. The normal form exhibits a symmetry-preserving Hopf bifurcation that may coalesce with a saddle node in a Bogdanov–Takens point, and a symmetry-breaking spatially inhomogeneous pitchfork bifurcation. We study here the Hopf bifurcation for the propagation of a single pulse in a ring by means of a center manifold reduction, and for a wave train by means of a multiscale analysis leading to a real Ginzburg–Landau equation as the corresponding amplitude equation. Both the center manifold reduction and the multiscale analysis show that the Hopf bifurcation is always subcritical independent of the parameters. This may have links to cardiac alternans, which have so far been believed to be stable oscillations emanating from a supercritical bifurcation. We discuss the implications for cardiac alternans and revisit the instability in some excitable media where the oscillations had been believed to be stable. In particular, we show that our condition for the onset of the Hopf bifurcation coincides with the well known restitution condition for cardiac alternans.
Efficient Schottky-quantum-dot photovoltaics: The roles of depletion, drift, and diffusion
Authors: Johnston Keith W. , Pattantyus-Abraham Andras G. , Clifford Jason P. , Myrskog Stefan H. , Hoogland Sjoerd , Shukla Harnik , Klem Ethan J. D. , Levina Larissa , Sargent Edward H.
Published: March 2008

PbS colloidal quantum dot photovoltaic devices in a Schottky architecture have demonstrated an infrared power conversion efficiency of 4.2%. Here, we elucidate the internal mechanisms leading to this efficiency. At relevant intensities, the drift length is 10μm for holes and 1μm for electrons. Transport within the 150nm wide depletion region is therefore highly efficient. The electron diffusion length of 0.1μm is comparable to neutral region width. We quantitatively account for the observed 37% external quantum efficiency, showing that it results from the large depletion width and long carrier lifetime combined.
Biomolecular simulations of membranes: Physical properties from different force fields
Authors: Siu Shirley W. I. , Vácha Robert , Jungwirth Pavel , Böckmann Rainer A.
Published: March 2008

Phospholipid force fields are of ample importance for the simulation of artificial bilayers, membranes, and also for the simulation of integral membrane proteins. Here, we compare the two most applied atomic force fields for phospholipids, the all-atom CHARMM27 and the united atom Berger force field, with a newly developed all-atom generalized AMBER force field (GAFF) for dioleoylphosphatidylcholine molecules. Only the latter displays the experimentally observed difference in the order of the C2 atom between the two acyl chains. The interfacial water dynamics is smoothly increased between the lipid carbonyl region and the bulk water phase for all force fields; however, the water order and with it the electrostatic potential across the bilayer showed distinct differences between the force fields. Both Berger and GAFF underestimate the lipid self-diffusion. GAFF offers a consistent force field for the atomic scale simulation of biomembranes.
Scaling laws for jet pulsations associated with high-resolution electrohydrodynamic printing
Authors: Choi Hong Kyoon , Park Jang-Ung , Park O Ok , Ferreira Placid M. , Georgiadis John G. , Rogers John A.
Published: March 2008

This paper presents simple scaling laws that describe the intrinsic pulsation of a liquid jet that forms at the tips of fine nozzles under electrohydrodynamically induced flows. The jet diameter is proportional to the square root of the nozzle size and inversely proportional to the electric field strength. The fundamental pulsation frequency is proportional to the electric field strength raised to the power of 1.5. These scaling relationships are confirmed by experiments presented here and by data from the literature. The results are important for recently developed high-resolution ink jet printing techniques and other applications using electrohydrodynamics.
Opaline metallic photonic crystals possessing complete photonic band gaps in optical regime
Authors: Kuo Cheng-Yu , Lu Shih-Yuan
Published: March 2008

We report the fabrication of opaline gold photonic crystals possessing complete photonic band gaps in the optical regime. The three-dimensional gold opaline photonic crystals exhibited two complete photonic band gaps in the optical regime.
Diversity predicts stability and resource use efficiency in natural phytoplankton communities
Authors: Ptacnik Robert , Solimini Angelo G. , Andersen Tom , Tamminen Timo , Brettum Pål , Lepistö Liisa , Willén Eva , Rekolainen Seppo
Published: March 2008

The relationship between species diversity and ecosystem functioning has been debated for decades, especially in relation to the “macroscopic” realm (higher plants and metazoans). Although there is emerging consensus that diversity enhances productivity and stability in communities of higher organisms; however, we still do not know whether these relationships apply also for communities of unicellular organisms, such as phytoplankton, which contribute ≈50% to the global primary production. We show here that phytoplankton resource use, and thus carbon fixation, is directly linked to the diversity of phytoplankton communities. Datasets from freshwater and brackish habitats show that diversity is the best predictor for resource use efficiency of phytoplankton communities across considerable environmental gradients. Furthermore, we show that the diversity requirement for stable ecosystem functioning scales with the nutrient level (total phosphorus), as evidenced by the opposing effects of diversity (negative) and resource level (positive) on the variability of both resource use and community composition. Our analyses of large-scale observational data are consistent with experimental and model studies demonstrating causal effects of microbial diversity on functional properties at the system level. Our findings point at potential linkages between eutrophication and pollution-mediated loss of phytoplankton diversity. Factors reducing phytoplankton diversity may have direct detrimental effects on the amount and predictability of aquatic primary production.
The lack of anti-idiotypic antibodies, not the presence of the corresponding autoantibodies to glutamate decarboxylase, defines type 1 diabetes
Authors: Oak Shilpa , Gilliam Lisa K. , Landin-Olsson Mona , Törn Carina , Kockum Ingrid , Pennington Christina R. , Rowley Merrill J. , Christie Michael R. , Banga J. Paul , Hampe Christiane S.
Published: March 2008

Autoantibodies to glutamate decarboxylase 65 (GAD65Ab) are commonly believed to be a major characteristic for type 1 diabetes (T1D). We investigated the presence of GAD65Ab in healthy individuals (n= 238) and first-degree relatives (FDRs) of T1D patients (n= 27) who tested negative for GAD65Ab in conventional RIAs. Sera were applied to affinity columns coated with GAD65-specific mAbs to absorb anti-idiotypic antibodies (anti-Ids). The absorbed sera were analyzed for binding to GAD65 by RIAs. Both healthy individuals and FDRs present GAD65Ab that are inhibited by anti-Id, masking them in conventional detection methods. The presence of GAD65Ab-specific anti-Ids was confirmed by competitive ELISA. Remarkably, T1D patients (n= 54) and Stiff Person Syndrome patients (n= 8) show a specific lack of anti-Ids to disease-associated GAD65Ab epitopes. Purified anti-Ids from healthy individuals and FDRs inhibited the binding of GAD65Ab from T1D patients to GAD65. We conclude that masked GAD65Ab are present in the healthy population and that a lack of particular anti-Ids, rather than GAD65Abper se, is a characteristic of T1D. The lack of these inhibitory antibodies may contribute to T cell activation by GAD65Ab.
Nerve Growth Factor Regulation of Cyclin D1 in PC12 Cells through a p21RASExtracellular Signal-regulated Kinase Pathway Requires Cooperative Interactions between Sp1 and Nuclear Factor-κB
Authors: Marampon Francesco , Casimiro Mathew C. , Fu Maofu , Powell Michael J. , Popov Vladimir M. , Lindsay Jaime , Zani Bianca M. , Ciccarelli Carmela , Watanabe Genichi , Lee Richard J. , Pestell Richard G.
Published: March 2008

The PC12 pheochromocytoma cell line responds to nerve growth factor (NGF) by exiting from the cell cycle and differentiating to induce extending neurites. Cyclin D1 is an important regulator of G1/S phase cell cycle progression, and it is known to play a role in myocyte differentiation in cultured cells. Herein, NGF induced cyclin D1 promoter, mRNA, and protein expression via the p21RASpathway. Antisense- or small interfering RNA to cyclin D1 abolished NGF-mediated neurite outgrowth, demonstrating the essential role of cyclin D1 in NGF-mediated differentiation. Expression vectors encoding mutants of the Ras/mitogen-activated protein kinase pathway, and chemical inhibitors, demonstrated NGF induction of cyclin D1 involved cooperative interactions of extracellular signal-regulated kinase, p38, and phosphatidylinositol 3-kinase pathways downstream of p21RAS. NGF induced the cyclin D1 promoter via Sp1, nuclear factor-κB, and cAMP-response element/activated transcription factor sites. NGF induction via Sp1 involved the formation of a Sp1/p50/p107 complex. Cyclin D1 induction by NGF governs differentiation and neurite outgrowth in PC12 cells.
South Korea: Economic and Social Consequences of Globalization
Authors: You Jong‐Ii , Lee Ju‐Ho
Published: March 2008

Only a while ago, the South Korean economy was the envy of the developing world, and its success was scrutinized by numerous analysts, with most agreeing that the secret of this success was a judicious mix of the state and the market. However, the exact mix of the state and the market has undergone through some changes, with, in particular, a steady, albeit gradual and patchy, move toward liberalization since the early 1980s; the impact of this on the labor market and social policy is not easily observable in the Korean case because of the very gradual nature of the process. The liberalization took a serious turn only a few years ago with a series of measures concerning capital accounts; the end result was the catastrophic financial crisis of 1997–8, which, no doubt, will have profound effects on the labor market and social policy for years to come. In this chapter, the overall developments in the political economy of Korea since 1980 are reviewed, with a focus on the connections among liberalization policies, the macroeconomic and labor market developments, and the social consequences. The chapter is organized as follows: the first section analyzes the political economy of liberalization in Korea – how it happened, why it happened, and why it went wrong; the second section describes the macroeconomic developments in the era of liberalization; the third section takes a closer look at the labor market, discussing changes in wage inequalities; the next section examines problems of social policy; this is followed by conclusions and recommendations.
Introduction
Authors: Silvia Paul J.
Published: March 2008

Psychology has long been attracted to the study of interest, curiosity, and intrinsic motivation. Many areas of psychology have grappled with interest, particularly with why some things are interesting and how stable interests develop. The study of interest sorts into two fields: (1) interest as a part of emotional experience, curiosity, and momentary motivation (the study of “interest”); and (2) interest as a part of personality, motivation, and people's idiosyncratic hobbies, goals, and avocations (the study of “interests”). This chapter points out that interest and interests have been studied in diverse and isolated areas of psychology; this book's central goal is to bring these disparate areas of research together, using an emphasis on cognition and emotion. The chapter concludes by foreshadowing the chapters that follow.
Interest as an Emotion
Authors: Silvia Paul J.
Published: March 2008

This chapter reviews research on interest as an emotion. Modern theories in affective science propose that emotions consist of components, such as facial and vocal expressions, subjective experience, motivational functions, and physiological changes. A small body of work suggests that the experience of interest involves changes in facial expressions and vocal expressions. The function of interest is to motivate knowledge-seeking and exploration, which over time builds knowledge and competence. Interest's subjective quality is positive and active, consistent with its approach-oriented function. These components are coherent: subjective, expressive, and behavioral components of interest correlate with each other, indicating an organized emotional response. Finally, many experiments on emotion and aesthetics show that interest is distinct from the similar emotion of happiness/enjoyment: they have different causes and different effects on exploration.
Ecology and Evolution of Mating Behavior in Freshwater Amphipods
Authors: Wellborn Gary A. , Cothran Rickey D.
Published: March 2008

Freshwater amphipods are used as a research model for studies of female mating preferences, the nature of benefits that drive female choice, and the influence of sexual conflict on female preference. Direct selection on female mating preferences is hypothesized to occur during the contact pairing phase, because costs incurred or benefits gained by females during pairing are likely to depend on traits of guarding males. Comparative studies of ecomorphs in the genus Hyalella shed light on the evolution of female preference and preferred male traits. In species from habitats where large body size is favored by ecological processes females prefer larger males. In species subject to intense fish predation, however, mortality selection favors small body size and female preference for larger males is weak. These divergent mating biases are consistent with direct and indirect selection on female preference acting under the disparate regimes of natural selection faced by the ecomorphs.
The Mating System of Symbiotic Crustaceans
Authors: Baeza J. Antonio , Thiel Martin
Published: March 2008

This chapter proposes a conceptual model predicting the mating system of symbiotic crustaceans. It assumes that males and females have different optimal mating strategies which they attempt to attain by defending and moving between hosts, and that host characteristics and predation risk limit the behavioral options of symbiotic individuals. Five mating systems are predicted: (i) monogamy when predation risk is high, hosts are scarce, morphologically simple, and small in size; (ii) host-defense polygyny when predation risk is high, hosts are scarce, simple, and intermediate in size; (iii) pure-search polygynandry of mobile females when predation risk is low, hosts are abundant, complex, and large; (iv) pure-search polygynandry of sedentary females when predation risk is moderate to high, hosts are scarce, and extremely small; and (v) female-centered polygyny when predation risk is moderate, hosts are neither abundant nor scarce, and intermediate in size. Empirical evidence supports the model's predictions.
Comparative Sociobiology of Spiny Lobsters
Authors: Childress Michael J.
Published: March 2008

Spiny lobsters show a wide range of social behaviors along a continuum from solitary asocial species to highly gregarious social species. Phylogenetic comparative analysis of social condition was unable to determine if the spiny lobster common ancestor was social or asocial, but suggests that several modern asocial taxa may have evolved from social ancestors. All asocial spiny lobsters are obligate coral reef species that settle directly into their adult habitat and do not undergo the ontogenetic habitat transition common among social species. Species that change habitats during their lifetime have strong attraction to conspecific cues, leading to shelter sharing, coordinated group defense behaviors, and even single-file migratory queues. Using conspecific cues as a form of public information to assess the quality of new habitats may provide an important and widespread advantage to spiny lobsters and many other social species.
Liquidating in Chapter 11
Authors: Branch Dr. Ben S. , Ray Hugh M. , Russell Robin
Published: March 2008

This chapter explains the liquidation of a business in a proceeding under Chapter 11 of the United States Bankruptcy Code using a liquidating plan of reorganization. The negotiation, confirmation, and implementation of a liquidating plan — sometimes referred to as a “pot plan” — together with the substantial advantages of liquidating under such a plan are discussed. Vehicles for managing the liquidation, such as liquidating trusts and limited liability companies, are outlined. The central focus is on the duties, powers, oversight, and compensation of the liquidator under the plan. This person is often referred to as the liquidating trustee.
Locating and Disposing of Assets
Authors: Branch Dr. Ben S. , Ray Hugh M. , Russell Robin
Published: March 2008

This chapter sets out the process for finding and evaluating the liquid assets, illiquid assets, disputed assets, wasting assets, and contingent assets of the business. To describe what to do with them, the standard asset valuation and sale methods are discussed. The bankruptcy sale procedure guidelines and the guidelines for employing investment bankers, art dealers, appraisers, auctioneers, and the like to assist in the sale process are set forth. The aim is to understand the appropriate disposition methods for particular assets (i.e., sale options), determine the price of each asset to be liquidated, and understand the abandonment option if circumstances so warrant.
Expression in Natural Speech
Authors: Tatham Mark , Morton Katherine
Published: March 2008

This chapter details some contributions of the results of biological and cognitive processing to natural speech. It presents the general concept of classifying basic and secondary emotions. A vector model of emotion is suggested and the importance of dynamic modeling is emphasized. The problems of an adequate approach to modelling variability, and the relationship between variability and adequate acoustic modeling is discussed. Problems inherent in collecting useable data bases are identified.
The Perception of Expression
Authors: Tatham Mark , Morton Katherine
Published: March 2008

This chapter emphasizes the goal of the speaker as the production of a speech waveform containing the components, which will trigger adequate perception in the listener. Current limitations to characterizing acoustic triggers are discussed, including the listener’s ability to differentiate acoustic signals and the non-linearity in the relation between the signal and listener. The relationship between rendering the speaker’s plan and the ability to assign a perceptually useful label to the speech waveform is emphasized.
Expressive Synthesis: The Longer Term
Authors: Tatham Mark , Morton Katherine
Published: March 2008

Synthesis systems need to address several difficulties to produce acceptable expressive synthetic speech. It is argued that the role of adequate phonological description, robust biological models of the speaking system, and the need for a supervisory agent — the cognitive phonetic agent — are essential to building expressive synthesis systems. Such agents are sometimes referred to as ‘cerebral tools’.
Linear time-varying models can reveal non-linear interactions of biomolecular regulatory networks using multiple time-series data
Authors: Kim Jongrae , Bates Declan G. , Postlethwaite Ian , Heslop-Harrison Pat , Cho Kwang-Hyun
Published: March 2008

Motivation: Inherent non-linearities in biomolecular interactions make the identification of network interactions difficult. One of the principal problems is that all methods based on the use of linear time-invariant models will have fundamental limitations in their capability to infer certain non-linear network interactions. Another difficulty is the multiplicity of possible solutions, since, for a given dataset, there may be many different possible networks which generate the same time-series expression profiles.

Results: A novel algorithm for the inference of biomolecular interaction networks from temporal expression data is presented. Linear time-varying models, which can represent a much wider class of time-series data than linear time-invariant models, are employed in the algorithm. From time-series expression profiles, the model parameters are identified by solving a non-linear optimization problem. In order to systematically reduce the set of possible solutions for the optimization problem, a filtering process is performed using a phase-portrait analysis with random numerical perturbations. The proposed approach has the advantages of not requiring the system to be in a stable steady state, of using time-series profiles which have been generated by a single experiment, and of allowing non-linear network interactions to be identified. The ability of the proposed algorithm to correctly infer network interactions is illustrated by its application to three examples: a non-linear model for cAMP oscillations in Dictyostelium discoideum, the cell-cycle data for Saccharomyces cerevisiae and a large-scale non-linear model of a group of synchronized Dictyostelium cells.

Availability: The software used in this article is available from http://sbie.kaist.ac.kr/software

Contact:  ckh@kaist.ac.kr

Supplementary information: Supplementary data are available at Bioinformatics online.
Rheological Properties of Fermented Rice Flour Gel
Authors: Lu Zhan‐Hui , Yuan Mei‐Lan , Sasaki Tomoko , Li Li‐Te , Kohyama Kaoru
Published: March 2008

To clarify the rheological properties of fermented rice noodle (sour mifen) produced in South China, we studied the mechanical properties of gels made from fermented and nonfermented (control) rice flours using static tensile testing, two‐bite testing, and dynamic viscoelastic measurement. Rheological measurement under large deformation showed that retrogradation in fermented rice gel proceeded more slowly than in nonfermented rice gel. Lower hardness and brittleness and higher cohesiveness and resilience (degree of recovery) for gels made from fermented rice flour demonstrated that the gel was less firm but more elastic and flexible. Storage moduli of both types of gel increased with time, but the starch retrogradation was suppressed for fermented rice gel. Fermented rice gel exhibited higher resilience and lower rigidity than nonfermented gel, thus the gel stability improved. The chemical analysis of both starches suggests that the partial hydrolysis of amylopectin occurred during the fermentation process.
Relationship of Bread Quality to Kernel, Flour, and Dough Properties
Authors: Dowell F. E. , Maghirang E. B. , Pierce R. O. , Lookhart G. L. , Bean S. R. , Xie F. , Caley M. S. , Wilson J. D. , Seabourn B. W. , Ram M. S. , Park S. H. , Chung O. K.
Published: March 2008

This study measured the relationship between bread quality and 49 hard red spring (HRS) or 48 hard red winter (HRW) grain, flour, and dough quality characteristics. The estimated bread quality attributes included loaf volume, bake mix time, bake water absorption, and crumb grain score. The best‐fit models for loaf volume, bake mix time, and water absorption had R2 values of 0.78–0.93 with five to eight variables. Crumb grain score was not well estimated, and had R2 values ≈0.60. For loaf volume models, grain or flour protein content was the most important parameter included. Bake water absorption was best estimated when using mixograph water absorption, and flour or grain protein content. Bake water absorption models could generally be improved by including farinograph, mixograph, or alveograph measurements. Bake mix time was estimated best when using mixograph mix time, and models could be improved by including glutenin data. When the data set was divided into calibration and prediction sets, the loaf volume and bake mix time models still looked promising for screening samples. When including only variables that could be rapidly measured (protein content, test weight, single kernel moisture content, single kernel diameter, single kernel hardness, bulk moisture content, and dark hard and vitreous kernels), only loaf volume could be predicted with accuracies adequate for screening samples.
Corn Gluten Meal as a Thermoplastic Resin: Effect of Plasticizers and Water Content
Authors: Lawton J. W. , Selling G. W. , Willett J. L.
Published: March 2008

Corn gluten meal (CGM) was studied to investigate the effect plasticizers and water have on its melt processing, and how this melting affects its mechanical properties. GCM containing varying amounts of water were mixed with 23% (w/w) plasticizers; (glycerol, triethylene glycol (TEG), dibutyl tartrate, and octanoic acid in a Haake bowl mixer at 80°C. The amount of water in the CGM affected the amount of torque produced in the Haake mixer. This increase in torque was correlated with how well the CGM melted in the mixer. SEM images of CGM melted in the mixer showed a more uniform homogenous structure when processed at its optimum moisture content. Glycerol, TEG, and dibutyl tartrate produced the greatest torque when the CGM contained <1% water. Octanoic acid produced the greatest torque when the CGM was processed at 8% moisture. CGM plasticized with TEG and octanoic acid were mixed at either their optimum moisture or at 9.6% moisture and then compression molded into tensile bars. The tensile strengths of the bars that were mixed at their optimum moisture content were significantly greater than the bars mixed at 9.6% moisture. The tensile properties of the CGM samples were affected by relative humidity (rh). The tensile strength decreased and elongation increased as relative humidity increased. CGM plasticized with TEG saw a greater changes in its tensile properties due to relative humidity than did octanoic acid plasticized CGM.
Staling Effects When Adding Low Amounts of Normal and Heat‐Treated Barley Flour to a Wheat Bread
Authors: Purhagen Jeanette K. , Sjöö Malin E. , Eliasson Ann‐Charlotte
Published: March 2008

The properties of a white wheat bread could be changed by adding normal or heat‐treated barley flour in small amounts (2 and 4%) to a white wheat bread recipe. Differences regarding gelatinization as well as retrogradation properties were found when analyzing the two flours in model systems. The heat‐treated flour was fully gelatinized due to prior time, temperature, and pressure treatment and could therefore absorb larger amounts of water than the other flours. In gelatinized model systems with 40% flour (dwb), the heat‐treated barley flour contained less retrograded amylopectin as compared with normal barley flour after storage for up to 14 days, whereas no differences were found with 20% flour (dwb). However, stored breads showed an increased retrogradation of amylopectin (as measured by differential scanning calorimetry [DSC]) when 2% pretreated barley flour was added as compared with addition of 2% normal barley flour. On the other hand, there were no significant differences at the 4% level. Addition of either of the barley flours resulted in less firm breads during storage as compared with the control breads. Increased water absorption in barley flour and thus increased water content in the breads or different water‐binding capacities of the flour blends could explain these results. The present study indicated that water had a stronger influence on bread firmness than the retrogradation of amylopectin. This conclusion was based on breads with pretreated barley flour being less firm than breads with normal barley flour, although the retrogradation, as determined by DSC, was higher.
Effect of DDGS, Moisture Content, and Screw Speed on Physical Properties of Extrudates in Single‐Screw Extrusion
Authors: Chevanan Nehru , Rosentrater Kurt A. , Muthukumarappan Kasiviswanathan
Published: March 2008

Three isocaloric (3.5 kcal/g) ingredient blends containing 20, 30, and 40% (wb) distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, and mineral and vitamin mix, with net protein adjusted to 28% (wb) for all blends, were extruded in a single‐screw laboratory‐scale extruder at screw speeds of 100, 130, and 160 rpm, and 15, 20, and 25% (wb) moisture content. Increasing DDGS content from 20 to 40% resulted in a 37.1, 3.1, and 8.4% decrease in extrudate durability, specific gravity, and porosity, respectively, but a 7.5% increase in bulk density. Increasing screw speed from 100 to 160 rpm resulted in a 20.3 and 8.8% increase in durability and porosity, respectively, but a 12.9% decrease in bulk density. On the other hand, increasing the moisture content from 15 to 25% (wb) resulted in a 28.2% increase in durability, but an 8.3 and 8.5% decrease in specific gravity and porosity, respectively. Furthermore, increasing the screw speed and moisture content of the blends, respectively, resulted in an increase of 29.9 and 16.6% in extruder throughput. The extrudates containing 40% DDGS had 8.7% lower brightness, as well as 20.9 and 16.9% higher redness and yellowness, compared with the extrudates containing only 20% DDGS. Increasing the DDGS content from 20 to 40% resulted in a 52.9 and 51.4% increase in fiber and fat content, respectively, and a 7.2% decrease in nitrogen free extract. As demonstrated in this study, ingredient moisture content and screw speed are critical considerations when producing extrudates with ingredient blends containing DDGS, as they are with any other ingredients.