cssi/SciSciGPT-SciSciNet huggingface dataset:
Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

Optical Coherence Tomography (OCT) has seen broad application in dentistry including early carious lesion detection and imaging defects in resin composite restorations. This study investigates expanding the clinical usefulness by investigating methods to use OCT for obtaining three-dimensional (3D) digital impressions, which can be integrated to CAD/CAM manufacturing of indirect restorations. 3D surface topography ‘before’ and ‘after’ a cavity preparation was acquired by an intraoral cross polarization swept source OCT (CP-OCT) system with a Micro-Electro-Mechanical System (MEMS) scanning mirror. Image registration and segmentation methods were used to digitally construct a replacement restoration that modeled the original surface morphology of a hydroxyapatite sample. After high resolution additive manufacturing (e.g. polymer 3D printing) of the replacement restoration, micro-CT imaging was performed to examine the marginal adaptation. This study establishes the protocol for further investigation of integrating OCT with CAD/CAM of indirect dental restorations.
Avoiding the Emptiness: The Full Infant

The recently reported findings of cognitive competence in young infants are, in several ways, puzzling. Phenomena that hundreds of years of study had not revealed have been displayed in our journals over the last decade. This paper explores the displays as part of a pervasive loss of confidence in science in general and in positive developmental psychology in particular. The full infant may have been constructed to save us from the disorder of no longer having shared conceptual models, or even assured research procedures.
Natural history and the clinic: the regional ecology of allergy in America

Abstract This paper challenges the presumed triumph of laboratory life in the history of twentieth-century biomedical research through an exploration of the relationships between laboratory, clinic, and field in the regional understanding and treatment of allergy in America. In the early establishment of allergy clinics, many physicians opted to work closely with botanists knowledgeable about the local flora in the region to develop pollen extracts in desensitization treatments, rather than rely upon pharmaceutical companies that had adopted a principle of standardized vaccines beholden to bacteriology that gave no thought to the particularities of place where their products were to be sold. Natural historical sciences like plant ecology and systematics furnished important knowledge, resources, and practices in establishing a medical marketplace for allergy in America. And botanists similarly profited from biomedicine and allergic bodies in extending their network of knowledge about the plant world.
Hard‐segment polymorphism in MDI/diol‐based polyurethane elastomers

X-ray analyses of methylene-bis(4)phenyl isocynate(MDI)/diol/poly(tetramethylene adipate) polyurethane elastomers prepared using hexanediol (HDO), butanediol (BDO), and propanediol (PDO) point to the development of a second crystalline structure in the hard segments as a result of thermal elongation and annealing. The HDO polymer crystallizes initially in the fully extended conformation, but a second crystal structure, a contracted form, develops with stretching and annealing at 130°C. In contrast, the BDO and PDO polymers crystallize initially in contracted conformation, but fully extended forms develop as a result of elongation and annealing. Only a contracted conformation has been seen so far in hard segments prepared using ethylene glycol (EDO) as the chain extender. These results correlate very well with DSC data for the same polymers. The development of the new crystal structures is accompanied by the appearance of new hard-segment melting peaks in the DSC traces. For the HDO polymer, the new peak for the contracted form appears at a higher temperature than that for the original extended form; for the BDO and PDO polymers the new peaks for the extended forms appear at lower temperatures than those for the contracted forms. Only a single peak is seen for the EDO polymer, for which only one crystal structure has been detected for the hard segments. These results indicate that the development of polymorphic crystal structures must be taken into account in interpreting the multiple melting phenomena seen for the hard domains in polyurethane elastomers.
A Microtubule-associated Protein (MAP2) Kinase Restores Microtubule Motility in Embryonic Brain

Motility driven by the microtubule motors, kinesin and cytoplasmic dynein, is inhibited by MAP2 (Lopez, L. A., and Sheetz, M. P.(1993) Cell Motil. Cytoskeleton 24, 1-16). The MAP2 inhibition is reversed by a kinase that is co-purified with chicken embryonic MAP2, completely releasing MAP2 from the microtubules. We have identified this activity with a kinase, embryonic MAP2 kinase (Mr = 100,000), which phosphorylates MAP2 at serine amino acid residues. This kinase is c-AMP independent and inhibited by potassium fluoride and glycerol 2-phosphate. Only the phosphorylation produced by embryonic MAP2 kinase can change the affinity of MAP2 by microtubules. Bovine MAP2 kinase, Cdc2 kinase, mitogenic activated protein kinase, and the NIMA kinase are able to phosphorylate MAP2 but do not change the affinity for microtubules. In vivo, embryonic MAP2 kinase could play a major role in the regulation of motility and positioning of membranous organelles within the cells even at substoichiometric levels.
Host protein requirements for in vitro site-specific DNA inversion

Flagellar phase variation is mediated by a recombination event that occurs at specific sites leading to inversion of a chromosomal segment of DNA. The presence of a 60 bp recombinational enhancer sequence on the DNA substrate molecule results in a 150-fold stimulation in the initial rate of inversion. The protein components required for inversion have been purified. They include the 21,000 dalton recombinase (Hin), a 12,000 dalton host protein (Factor II), and one of the major histone-like proteins of E. coli HU. The dependence of the initial rate of recombination on HU varies with respect to the location of the recombinational enhancer. The role of HU, Factor II, and the enhancer in facilitating site-specific recombination is discussed.
Unsteady Fluid Structure Interaction in a Turbine Blade

An unsteady, three dimensional Navier-Stokes solution in rotating frame formulation for turbomachinery applications has been described. Casting the governing equations in a rotating frame enables the freezing of grid motion and results in substantial savings in computer time. Heat transfer to a gas turbine blade was computationally simulated by finite element methods and probabilistically evaluated in view of the several uncertainties in the performance parameters. The interconnection between the CFD code and finite element structural analysis code was necessary to couple the thermal profiles with the structural design. The stresses and their variations were evaluated at critical points on the turbine blade. Cumulative distribution functions and sensitivity factors were computed for stresses due to the aerodynamic, geometric, material and thermal random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The analysis leads to the selection of the appropriate materials to be used and to the identification of both the most critical measurements and parameters.© 2005 ASME
Direct Relations Between Curvatures of Surfaces Being in Continuous Tangency

The motion of two solids provided with surfaces Σ1 and Σ2 being in continuous tangency either along a line or at a point at every instant is considered. The authors propose an approach for determining direct relations between: (i) the principal curvatures and directions of Σ1 and Σ2, (ii) the normal curvatures of Σ1 and Σ2 along two mutually perpendicular directions chosen in the tangent plane. The performed diagonalization of the curvature matrix enables to determine the directions and magnitude for the extreme relative normal curvatures of Σ1 and Σ2. The proposed approach enables: (i) to simplify substantially the determination of curvatures when one of the surfaces is represented in threeparametric form but with related parameters, (ii) to simplify the computerized simulation of contact of gear tooth surfaces, and (iii) to simplify the determination of curvatures of a surface generated by a tool with the given surface. The approach is illustrated with the example of generation of a worm (screw) by a cone surface of the tool. Es wird die Bewegung zweier Festkorper mit Oberflachen Σ1 und Σ1 betrachtet, die in stetiger Beruhrung entweder entlang einer Linie oder zu jedem Zeitpunkt in einem Punkt sind. Die Autoren schlagen einen Ansatz vor zur Bestimmung direkter Beziehungen zwischen: (i) den Hauptkrummungen und Richtungen von Σ1 und Σ2, (ii) den Normalkrummungen von Σ1 und Σ2 entlang der beiden aufeinander senkrecht stehenden Richtungen, die in der Tangentialebene gewahlt wurden. Die vorgestellte Diagonalisierung der Krummungsmatrix gestattet, die Richtungen und Grosen der extremalen relativen Normalkrummungen von Σ1 und Σ2 zu bestimmen. Der vorgeschlagene Ansatz erlaubt: (i) die Bestimmung der Krummungen wesentlich zu vereinfachen, wenn eine der Oberflachen in dreiparametrischer Gestalt, jedoch mit aufeinander bezogenen Parametern dargestellt ist, (ii) die Computersimulation des Kontakts von Getriebezahnoberflachen zu vereinfachen und (iii) die Bestimmung der Krummungen einer Oberflache zu vereinfachen, die von einem Werkzeug mit gegebener Oberflache erzeugt wird. Der Ansatz wird durch das Beispiel der Erzeugung eines Schneckengetriebes durch eine Kegeloberflache des Werkzeugs illustriert.
Photoconduction and photorefraction in molecularly doped polymers

Abstract During the past 20 years organic photoconductors have found increasing application in electrophotographic copying and printing. Charge carrier mobility in these materials is achieved by doping a polymer matrix with up to 50% by weight of a molecular donor (acceptor) which provides sites for the hopping of holes (electrons). Sensitization to the desired wavelength of light is obtained via a suitable charge generation dye or pigment, frequently in the form of a second layer distinct from the transport layer. More recently, optically nonlinear polymers have been synthesized by the incorporation of conjugated donor-acceptor species into macromolecular chains and/or networks. When the donor-acceptor chromophores are aligned, for example, by poling in an electric field, second-order optical nonlinearity, including an electro-optic effect, is observed. Photoconductivity and nonlinearity can be combined for example, by doping a nonlinear polymer with a molecular charge transport agent, to yield a potentially photorefractive material. The photorefractive effect in several such formulations has been confirmed and characterized by a combination of absorption, photoconductivity, mobility, electro-optic, four-wave mixing (holography) and grating phase measurements. The results are discussed in terms of a mechanism involving (i) charge generation on the nonlinear chromophore, (ii) transport of holes by hoping among molecular donor sites, (iii) charge trapping to develop a space-charge electric field and (iv) modulation of the refractive index via the electro-optic effect.
INVERSE SCATTERING OF FIRST ORDER SYSTEMS IN THE PLANE RELATED TO NONLINEAR MULTIDIMENSIONAL EQUATIONS

A method for solving the inverse problem of certain hyperbolic as well as elliptic systems of $n$ equations in the plane is given. This result can be used to linearize the initial-value problem of several physically significant nonlinear evolution equations in two spatial and one temporal dimension.
A perturbation theory treatment of oscillating magnetic fields in the radical pair mechanism

Abstract This paper describes an application of time-dependent perturbation theory to the calculation of singlet-to-triplet yields in radical pair reactions for oscillating magnetic fields. It outlines an iterative approach, based on the Schrodinger equation, that should hold for any order of perturbation theory and then gives explicit expressions up to second order in the oscillating field strength for the dependence of the singlet-to-triplet yield on the frequency of the oscillating field. It then compares this method to other methods, namely, numerical integration and the rotating frame treatment, and gives sample results for exponential and Noyes time-dependences. Finally, assuming the radical pair mechanism can explain certain magnetic field effects in biology, this paper discusses several counterintuitive behaviors of the singlet-to-triplet yields that may account for conflicts in the magnetic field bioeffects literature.
A metamaterial-based series connected rectangular patch antenna array for UHF RFID Readers

In this paper, a new metamaterial-based printed antenna for UHF Radio Frequency Identification (RFID) Readers is presented. This antenna is designed such that several can be connected in series to provide local RFID coverage. In this work, simulation and measurements are shown to agree very well and that confined UHF communication can be achieved with this antenna. Furthermore, the geometry of the new metamaterial-based UHF RFID antenna is altered and the resonant frequency is computed using simulations. It is shown that by varying certain geometrical features of the array, the operating frequency can be increased and decreased in a predictable manner.
Energy Storage and Radiation $Q$ of Infinite Planar Dipole Phased Arrays

The exact stored energy, radiated power, and radiation quality factor of infinite planar phased arrays of dipole elements are presented for configurations in free space, over a ground plane, and on a grounded dielectric substrate. Radiated power and stored electric and magnetic energies are evaluated in terms of the two-dimensional spectral domain Floquet mode series representation of the element current. Characteristics of the radiated power and stored energies are clearly identified from propagating and evanescent spectra. In the presence of a ground plane, the dominant (0, 0) Floquet mode contributes to the stored energy, but not in the free-space case. Standard array configurations are analyzed, and the Q results are compared with impedance-derived values available by independent calculation.
Stability of reducible quadrature methods for Volterra integral equations of the second kind

Stability analysis of reducible quadrature methods for Volterra integral equations based on the test equation $$y(t) = 1 + \int\limits_0^t {(\lambda + \mu t + vs)y(s)ds,t \geqq 0} $$ is presented. The concept of absolute stability is defined and necessary and sufficient conditions for the method to be absolutely stable for given ?, μ, andv are derived. These conditions are illustrated for the class of ?-methods for integral equations. The main tool in our stability analysis is the theory of difference equations of Poincare type.
Inverse Correlation between the Extent of N-Glycan Branching and Intercellular Adhesion in Epithelia CONTRIBUTION OF THE Na,K-ATPase β1 SUBUNIT

The majority of cell adhesion molecules are N-glycosylated, but the role of N-glycans in intercellular adhesion in epithelia remains ill-defined. Reducing N-glycan branching of cellular glycoproteins by swainsonine, the inhibitor of N-glycan processing, tightens and stabilizes cell-cell junctions as detected by a 3-fold decrease in the paracellular permeability and a 2-3-fold increase in the resistance of the adherens junction proteins to extraction by non-ionic detergent. In addition, exposure of cells to swainsonine inhibits motility of MDCK cells. Mutagenic removal of N-glycosylation sites from the Na,K-ATPase β1 subunit impairs cell-cell adhesion and decreases the effect of swainsonine on the paracellular permeability of the cell monolayer and also on detergent resistance of adherens junction proteins, indicating that the extent of N-glycan branching of this subunit is important for intercellular adhesion. The N-glycans of the Na,K-ATPase β1 subunit and E-cadherin are less complex in tight renal epithelia than in the leakier intestinal epithelium. The complexity of the N-glycans linked to these proteins gradually decreases upon the formation of a tight monolayer from dispersed MDCK cells. This correlates with a cell-cell adhesion-induced increase in expression of GnT-III (stops N-glycan branching) and a decrease in expression of GnTs IVC and V (promote N-glycan branching) as detected by real-time quantitative PCR. Consistent with these results, partial silencing of the gene encoding GnT-III increases branching of N-glycans linked to the Na,K-ATPase β1 subunit and other glycoproteins and results in a 2-fold increase in the paracellular permeability of MDCK cell monolayers. These results suggest epithelial cells can regulate tightness of cell junctions via remodeling of N-glycans, including those linked to the Na,K-ATPase β1-subunit.
Using rule mining to understand appliance energy consumption patterns

Managing energy in the home is key to creating a sustainable future for our society. More tools are increasingly available to measure home energy usage, however these tools provide little insight into questions such as why an appliance consumes more energy than normal or what kinds of behavioral changes might be most likely to reduce energy usage in the home. To answer these questions, a deeper understanding of the causal factors that influence energy usage is necessary. In this work, we conduct a broad study of factors that influence energy consumption of individual devices in the home. Our first contribution is collection of a context-rich data set from six homes across the United States. The second contribution of this work is a set of insights into key factors influencing energy usage derived by the novel application of a rule mining algorithm to identify significant associations between energy usage and four key features: hour of the day, day of the week, use of other appliances in the home, and user-supplied annotations of activities such as working or cooking. Our analysis confirms our hypothesis that, though most devices show a regular pattern of daily or weekly use, this is not true for all devices. Associations that relate use of two different devices in the same home are often stronger, and are observed for nearly 25% of device uses. Overall, we observe that the associations derived from the first five weeks of data in our data set are sufficient to explain nearly 70% of the device uses in the subsequent five weeks of data, and over 90% of the associations identified during the first five weeks recur in the latter portion of the data set. The associations identified by our approach may be used to to aid in end-user applications that heighten awareness and encourage energy savings, improve energy disaggregation algorithms, or even detect anomalous uses that may signal problems in aging-in-place homes.
Correlation of symptoms, myocardial perfusion imaging, and anatomic narrowing of the left anterior descending artery

The use of myocardial perfusion imaging in assisting clinical decisions in patients with known coronary artery disease is well documented. Occasionally myocardial perfusion imaging may be also useful in patients with other causes of chest pain syndromes.
Ontology based policy interoperability in geo-spatial domain

With advances of digital technology two or more organizations form a federation for a temporary purpose. It is possible that an employee of an organization needs to access resource of another organization. While languages like XACML are very good for access control of a single organization, they are not able to address interoperability issues of such federations. Lack of interoperability of access control policies does not allow someone to access remote resources. In this paper we propose an approach by augmenting with knowledge-base, Ontology that will facilitate access control policies to provide resources of remote organizations. In addition, we introduce a new effect of the rule, partial permit in our application domain (Geo-Spatial).
Partitioned signature files: design issues and performance evaluation

A signature file acts as a filtering mechanism to reduce the amount of text that needs to be searched for a query. Unfortunately, the signature file itself must be exhaustively searched, resulting in degraded performance for a large file size. We propose to use a deterministic algorithm to divide a signature file into partitions, each of which contains signatures with the same “key.” The signature keys in a partition can be extracted and represented as the partition's key. The search can then be confined to the subset of partitions whose keys match the query key. Our main concern here is to study methods for obtaining the keys and their performance in terms of their ability to reduce the search space.Owing to the reduction of search space, partitioning a signature file has a direct benefit in a sequential search (single-processor) environment. In a parallel environment, search can be conducted in parallel effectively by allocating one or more partitions to a processor. Partitioning the signature tile with a deterministic method (as opposed to a random partitioning scheme) provides intraquery parallelism as well as interquery parallelism.In this paper, we outline the criteria for evaluating partitioning schemes. Three algorithms are described and studied. An analytical study of the performance of the algorithms is provided and the results are verified with simulation.
Regional differences in the contractile apparatus of intrafusal muscle fibers.

In spindles of rat muscles, the particular class of intrafusal fiber that is unreactive over its entire striated length when incubated for alkali-stable “myofibrillar” ATPase, exhibits pronounced regional differences in staining following incubation for acid-stable ATPase. This variation along the contractile polar regions of the fiber can easily lead to misinterpretations of intrafusal fiber type, as well as the erroneous suggestion of two distinct populations of muscle spindles. Furthermore, such regional staining differences are strongly suggestive of variations in the contractile apparatus along certain intrafusal muscle fibers.
Sex, money, and premarital partnerships in southern Malawi

In this paper, I argue two main points. First, in premarital, sexual partnerships in rural Malawi, the purpose of money exchange extends beyond the alleviation of female partners' economic constraints, and, second, by clarifying this broader purpose, it becomes possible to recognize where women exert control over their own sexual selves. These findings come from field observations and a rich set of in-depth interviews (N=54), bolstered on occasion by survey data, conducted with young women and men, aged 15-24 years, in the Balaka district in the southern region of the country. This research demonstrates that, contrary to typical expectations, money and gift transfers in sexual partnerships are part and parcel of the courting practices of young Malawian women and men. Transfers are as much about the expression of love and commitment as they are about meeting the financial needs of women or the acquisition of sex for men. Using narrative information to shed light on the semiotics of the sex-money link, these findings from Malawi offer a new perspective that broadens usual interpretations of transactional sex, the understanding of which is critical in fighting AIDS.
Study of the 84Sr(α, p) reaction

The 84Sr(α, p)87Y reaction is found to excite low-lying states with strengths very nearly equal to those observed in 86Sr(3He, d)87Y. Additional states observed in (α, p) but not in (3He, d) are candidates for states expected from a weak-coupling model.
Privacy, cryptography and free research

Early in July 1977, Mr. E.K. Gannett, IEEE Staff Director of Publishing Services, received a letter (with enclosures) from IEEE member J.A. Meyer of Bethesda, Maryland. The letter warned that some of those presenting papers at the forthcoming International Symposium on Information Theory sponsored by the IEEE Professional Group on Information Theory and possibly the Institute itself might be subject to prosecution by the Federal Government for violation of the Arms Export Control Act.
A method for quantifying the reliability of instrumentation for engineered safety features to improve accident sequence recognition in reactor control rooms

Abstract This work adapts fault trees from plant-specific probabilistic risk analyses (PRAs) to quantitatively evaluate the reliability of the instrumentation for engineered safety features (ESFs). The purpose is to help improve reactor operator recognition and identification of potential accident sequences. The PRA system fault trees provide a framework for assessing the plant indicators so that the plant conditions are made more readily apparent to plant personnel through the conversion of system fault trees to alarm trees. In the alarm tree, possible states of each instrumented alarm are identified as “true” or “false”. In addition, a “warning” status is also defined and integrated into the alarm analysis routine. The impact of this additional status condition on the Boolean laws used to evaluate the alarm trees is examined. An application is described for a BWR high pressure coolant injection system (HPCI) that would be utilized during many severe reactor accidents.
Sensory-Motor Networks Involved in Speech Production and Motor Control: An fMRI Study

Abstract Speaking is one of the most complex motor behaviors developed to facilitate human communication. The underlying neural mechanisms of speech involve sensory–motor interactions that incorporate feedback information for online monitoring and control of produced speech sounds. In the present study, we adopted an auditory feedback pitch perturbation paradigm and combined it with functional magnetic resonance imaging (fMRI) recordings in order to identify brain areas involved in speech production and motor control. Subjects underwent fMRI scanning while they produced a steady vowel sound /a/ (speaking) or listened to the playback of their own vowel production (playback). During each condition, the auditory feedback from vowel production was either normal (no perturbation) or perturbed by an upward (+ 600 cents) pitch-shift stimulus randomly. Analysis of BOLD responses during speaking (with and without shift) vs. rest revealed activation of a complex network including bilateral superior temporal gyrus (STG), Heschl's gyrus, precentral gyrus, supplementary motor area (SMA), Rolandic operculum, postcentral gyrus and right inferior frontal gyrus (IFG). Performance correlation analysis showed that the subjects produced compensatory vocal responses that significantly correlated with BOLD response increases in bilateral STG and left precentral gyrus. However, during playback, the activation network was limited to cortical auditory areas including bilateral STG and Heschl's gyrus. Moreover, the contrast between speaking vs. playback highlighted a distinct functional network that included bilateral precentral gyrus, SMA, IFG, postcentral gyrus and insula. These findings suggest that speech motor control involves feedback error detection in sensory (e.g. auditory) cortices that subsequently activate motor-related areas for the adjustment of speech parameters during speaking.
Cooperative Folding Units of Escherichia coli Tryptophan Repressor

A previously published computational procedure was used to identify cooperative folding units within tryptophan repressor. The theoretical results predict the existence of distinct stable substructures in the protein chain for the monomer and the dimer. The predictions were compared with experimental data on structure and folding of the repressor and its proteolytic fragments and show excellent agreement for the dimeric form of the protein. The results suggest that the monomer, the structure of which is currently unknown, is likely to have a structure different from the one it has within the context of the highly intertwined dimer. Application of this method to the repressor monomer represents an extension of the computations into the realm of evaluating hypothetical structures such as those produced by threading.
Desire and dread from the nucleus accumbens: cortical glutamate and subcortical GABA differentially generate motivation and hedonic impact in the rat.

Background GABAergic signals to the nucleus accumbens (NAc) shell arise from predominantly subcortical sources whereas glutamatergic signals arise mainly from cortical-related sources. Here we contrasted GABAergic and glutamatergic generation of hedonics versus motivation processes, as a proxy for comparing subcortical and cortical controls of emotion. Local disruptions of either signals in medial shell of NAc generate intense motivated behaviors corresponding to desire and/or dread, along a rostrocaudal gradient. GABA or glutamate disruptions in rostral shell generate appetitive motivation whereas disruptions in caudal shell elicit fearful motivation. However, GABA and glutamate signals in NAc differ in important ways, despite the similarity of their rostrocaudal motivation gradients. Methodology/Principal Findings Microinjections of a GABAA agonist (muscimol), or of a glutamate AMPA antagonist (DNQX) in medial shell of rats were assessed for generation of hedonic “liking” or “disliking” by measuring orofacial affective reactions to sucrose-quinine taste. Motivation generation was independently assessed measuring effects on eating versus natural defensive behaviors. For GABAergic microinjections, we found that the desire-dread motivation gradient was mirrored by an equivalent hedonic gradient that amplified affective taste “liking” (at rostral sites) versus “disliking” (at caudal sites). However, manipulation of glutamatergic signals completely failed to alter pleasure-displeasure reactions to sensory hedonic impact, despite producing a strong rostrocaudal gradient of motivation. Conclusions/Significance We conclude that the nucleus accumbens contains two functional affective keyboards for amino-acid signals: a motivation-generating keyboard and a hedonic-generating keyboard. Corticolimbic glutamate signals and subcortical GABA signals equivalently engage the motivation keyboard to generate desire and-or dread. Only subcortical GABA signals additionally engage the hedonic keyboard to amplify affective “liking” and “disliking” reactions. We thus suggest that top-down cortical glutamate signals powerfully regulate motivation components, but are relatively unable to penetrate core hedonic components of emotion. That may carry implications of limits to therapeutic regulation of pathological emotions.
Adaptive Nonlinear Attitude Control and Momentum Management of Spacecraft

An indirect adaptive nonlinear controller is investigated for attitude control and momentum management of evolutionary spacecraft. The control law is based on the theory of nonlinear feedback linearization. A new state transformation is introduced: one that converts the original nonlinearsystem into normal canonical form. Once in canonical form, nonlinear feedback is used to generate a linear response in the transformed coordinates. To make the nonlinear controller adaptive, a parameter identie cation scheme, utilizing an extended Kalman e lter, is added for mass property estimation. Probing signals are introduced to enhance the observability of the mass properties. Simulation results show that the adaptive nonlinear controller stabilizes the International Space Station during mass property changes, successfully performs momentum management, and provides real-time estimates of the mass properties in a realistic environment.
Identification of Enzymes Homologous to Isocitrate Dehydrogenase That Are Involved in Coenzyme B and Leucine Biosynthesis in Methanoarchaea

Two putative Methanococcus jannaschii isocitrate dehydrogenase genes, MJ1596 and MJ0720, were cloned and overexpressed in Escherichia coli, and their gene products were tested for the ability to catalyze the NAD- and NADP-dependent oxidative decarboxylation of dl-threo-3-isopropylmalic acid, threo-isocitrate, erythro-isocitrate, and homologs of threo-isocitrate. Neither enzyme was found to use any of the isomers of isocitrate as a substrate. The protein product of the MJ1596 gene, designated AksF, catalyzed the NAD-dependent decarboxylation of intermediates in the biosynthesis of 7-mercaptoheptanoic acid, a moiety of methanoarchaeal coenzyme B (7-mercaptoheptanylthreonine phosphate). These intermediates included (−)-threo-isohomocitrate [(−)-threo-1-hydroxy-1,2,4-butanetricarboxylic acid], (−)-threo-iso(homo)2citrate [(−)-threo-1-hydroxy-1,2,5-pentanetricarboxylic acid], and (−)-threo-iso(homo)3citrate [(−)-threo-1-hydroxy-1,2,6-hexanetricarboxylic acid]. The protein product of MJ0720 was found to be α-isopropylmalate dehydrogenase (LeuB) and was found to catalyze the NAD-dependent decarboxylation of one isomer of dl-threo-isopropylmalate to 2-ketoisocaproate; thus, it is involved in the biosynthesis of leucine. The AksF enzyme proved to be thermostable, losing only 10% of its enzymatic activity after heating at 100°C for 10 min, whereas the LeuB enzyme lost 50% of its enzymatic activity after heating at 80°C for 10 min.
The Archaeology of Food Preference

Food preference is a socially constructed concept in which both consumers and producers define what is “good to eat.” Staple crops and daily meals are an important component of these definitions, as the regular use of particular foods reinforces norms of identity. Food preferences also affect agricultural systems because choices among cultivars are based on social needs in addition to economic variables such as yield and caloric value. Through textual and archaeological evidence, the trajectory of rice production is examined for Sri Lanka, the Brahmaputra Valley, the Tamil region, and Vijayanagara. In these regions and elsewhere in South Asia, shared ideologies of food preference resulted in a consensus mode of agricultural production: Irrigation works increased the tax base for political leaders and the donation base for temple economies, but they also benefited local inhabitants who would have been able to partake of a preferred food on a more regular basis.
Importance of resource selection and social behavior to partitioning of hostile space by sympatric canids

Investigations into mechanisms of resource partitioning are particularly suited to systems where nascent interactive behaviors are observable. Wolf (Canis lupus) recolonization of the Greater Yellowstone Ecosystem provided such a system, and we were able to identify behaviors influencing the partitioning of resources by coyotes (Canis latrans) and wolves. We observed coyote-wolf interactions immediately after wolf recolonization, when reemergent behaviors mediating the outcome of competitive interactions were detectable and mechanisms of spatial avoidance were identifiable. Although coyotes used the same space as wolves, they likely minimized risk of encounter by making adaptive changes in resource selection based on perception of wolf activity and potential scavenging opportunities. When exploiting carrion subsidies (i.e., wolf-killed ungulates), coyotes relied on social behaviors (i.e., numerical advantage in concert with heightened aggression) to mitigate escalating risk from wolves and increase resource-holding potential. By adapting behaviors to fluctuating risk, coyotes might reduce the amplitude of competitive asymmetries. We concluded coyotes do not perceive wolves as a threat requiring generalized spatial avoidance. Rather, the threat of aggressive interactions with wolves is spatially discrete and primarily contained to areas adjacent to carrion resources.
Moving beyond narrative in nonlinear Web site design

The problems of nonlinear information design are not unique to modern media technologies such as the World-Wide Web. Newspaper writers have traditionally used guiding questions (who, what, when and where) to formulate the summary leads that allow each reader to idiosyncratically navigate a nonlinear narrative path through a newspaper. Thus, user access to nonlinear information on the World Wide Web likewise improves with the inclusion of question-guided summary leads. To formulate those summary leads, a site designer should likewise use guiding questions, but the designer should be aware that not all information belongs to the genre of narrative. Leading summaries in each genre differ in terms of their guiding questions.
Particle-based Variational Inference for Continuous Systems

Since the development of loopy belief propagation, there has been considerable work on advancing the state of the art for approximate inference over distributions defined on discrete random variables. Improvements include guarantees of convergence, approximations that are provably more accurate, and bounds on the results of exact inference. However, extending these methods to continuous-valued systems has lagged behind. While several methods have been developed to use belief propagation on systems with continuous values, recent advances for discrete variables have not as yet been incorporated. In this context we extend a recently proposed particle-based belief propagation algorithm to provide a general framework for adapting discrete message-passing algorithms to inference in continuous systems. The resulting algorithms behave similarly to their purely discrete counterparts, extending the benefits of these more advanced inference techniques to the continuous domain.
Computing the perspective projection aspect graph of solids of revolution

An algorithm for computing the aspect graph for a class of curved-surface objects based on an exact parcellation of 3-D viewpoint space is presented. The object class considered is solids of revolution. A detailed analysis of the visual events for this object class is given, as well as an algorithm for constructing the aspect graph. Numerical search techniques, based on a geometric interpretation of the visual events, have been devised to determine those visual event surfaces that cannot be calculated directly. The worst-case complexity of the number of cells in the parcellation of 3-D viewpoint space, and, hence, the number of nodes in the aspect graph, is O(N/sup 4/), where N is the degree of a polynomial that defines the object shape. A summary of the results for 20 different object descriptions is presented, along with a detailed example for a flower vase. >
Application to enhance the teaching and understanding of basic image processing techniques

Scientific visualization is the representation of data graphically as a means of gaining understanding and insight into the data. An excellent place to start learning scientific visualization is in the field of image processing, since it involves algorithms that help convert data into images. In today's technology-oriented world, the term 'image processing' generally refers to the processing of a two-dimensional data set using a computer. This was the main reason that the initial research was completed in the implementation of image processing techniques using a software called Advanced Visual Systems Express (AVS Express). There is a definite need to show how that would benefit instruction as a teaching aid, and also how it helps optimize the time taken to implement these different techniques using this software. It also increases user understanding of these techniques. It is possible to fully implement many of the different image processing techniques such as edge extraction, gradient operators, convolution, compression and extraction, as well as many others in a relatively short time. In comparison to previous attempts with other popular software such as MATLAB, the time difference proved to be immense. The main advantage of AVS software is that it provides a visual programming environment which allows the user to see the flow of information of the different algorithms as they are being implemented. Since no time is spent writing and correcting code, the understanding of the image processing techniques becomes much clearer in a shorter period of time, and thus in depth study is possible. We have developed a number of techniques and are in the process of integrating AVS Express into the curriculum for the Digital Image Processing (EE523) course at Tennessee State University as a teaching and study aid.
DOES RACE MODERATE SOCIAL SUPPORT AND PSYCHOLOGICAL DISTRESS AMONG RURAL OLDER ADULTS

Greater social support is associated with decreased psychological distress among older adults. Researchers have found racial differences in psychological distress. Might race moderate social support and psychological distress? The authors hypothesized African American collectivistic values could increase the importance of social support. Participants were rural adults aged 60 and older (N = 100). Multiple regression analyses controlled for health, income, education, and sex. Race moderated satisfaction with social support and psychological distress. However, greater satisfaction predicted less psychological distress among Caucasians while it was not associated with African Americans' distress in this sample. Achieving satisfaction with social support may be particularly important for Caucasians receiving therapy. Interventions may also address strategies to improve physical health, emotional support, and quality of social support, which significantly predicted psychological distress for both groups.
Test selection for a mass screeening program

Periodic mass screening is the scheduled application of a test to all members of a population to provide early detection of a randomly occurring defect or disease. This paper considers periodic mass screening with particular reference to the imperfect capacity of the test to detect an existing defect and the associated problem of selecting the kind of test to use. Alternative kinds of tests differ with respect to their reliability characteristics and their cost per application. Two kinds of imperfect test reliability are considered. In the first case, the probability that the test will detect an existing defect is constant over all values of elapsed time since the incidence of the defect. In the second case, the test will detect the defect if, and only if, the lapsed time since incidence exceeds a critical threshold T which characterizes the test. The cost of delayed detection is an arbitrary increasing function (the “disutility function”) of the duration of the delay. Expressions for the long-run expected disutility per unit time are derived for the above two cases along with results concerning the best choice of type of test (where the decision rules make reference to characteristics of the disutility function).
An integrated approach to evaluating urban forest functionality

Despite the fact that forests in urban areas play multiple and often conflicting roles, research and management efforts are typically geared towards a single role or purpose. Urban ecology addresses this multiplicity of function by viewing human and natural systems in urban areas not as separate entities, but as interacting components of an integrated whole. We present an interdisciplinary approach for evaluating the different ways that forests are often valued: economically, socially, and ecologically in residential areas of King County, WA. Economic function is measured as the change in housing prices attributed to location on the gradient, using a hedonic price model. For social function we use a survey to measure (1) residents’ use of parks and forests, and (2) satisfaction with their neighborhoods. We measure ecological function as songbird species richness, using bird survey data. Overlaying the curves of economic, social, and ecological function on the common axis of our urban gradient allows for relationships and tradeoffs to be qualitatively evaluated. Each function responds differently to the gradient. The housing price response is strongest at high and low levels of urbanization, with positive premiums in both areas. Satisfaction with neighborhood attributes decreases with increasing urbanization, while the likelihood of mentioning ‘parks’ as an important element of a resident’s neighborhood increases. Songbird richness peaks in less-developed areas. Evaluating the different functions together is an important step in recognizing and understanding the multiple roles forested areas play.
Is fibrillation chaos

Ventricular fibrillation is examined to determine whether it is an instance of deterministic chaos. Surface ECGs from dogs in fibrillation were used to generate a state space representation of fibrillation. Our analysis failed to identify a low-dimensional attractor that could be associated with fibrillation. The results suggest that fibrillation is similar to a nonchaotic random signal. We note, however, that such random-looking but nonchaotic behavior can also be generated by a nonlinear deterministic system.
Sunspot Group Decay

We examine daily records of sunspot group areas (measured in millionths of a solar hemisphere or μHem) for the last 130 years to determine the rate of decay of sunspot group areas. We exclude observations of groups when they are more than 60° in longitude from the central meridian and only include data when at least three days of observations are available following the date of maximum area for a group’s disk passage. This leaves data for over 18 000 measurements of sunspot group decay. We find that the decay rate increases linearly from 28 μHem day−1 to about 140 μHem day−1 for groups with areas increasing from 35 μHem to 1000 μHem. The decay rate tends to level off for groups with areas larger than 1000 μHem. This behavior is very similar to the increase in the number of sunspots per group as the area of the group increases. Calculating the decay rate per individual sunspot gives a decay rate of about 3.65 μHem day−1 with little dependence upon the area of the group. This suggests that sunspots decay by a Fickian diffusion process with a diffusion coefficient of about 10 km2 s−1. Although the 18 000 decay rate measurements are lognormally distributed, this can be attributed to the lognormal distribution of sunspot group areas and the linear relationship between area and decay rate for the vast majority of groups. We find weak evidence for variations in decay rates from one solar cycle to another and for different phases of each sunspot cycle. However, the strongest evidence for variations is with latitude and the variations with cycle and phase of each cycle can be attributed to this variation. High latitude spots tend to decay faster than low latitude spots.
Electroabsorption Measurements on Bifacial CIGS Solar Cell Devices

We report the first studies of electroabsorption in Cu(InGa)Se2 (CIGS) solar cell devices. We utilized a bifacial CIGS device with a Ga/(In+Ga) ratio of 0.8 (bandgap of 1.5 eV) deposited onto semi-transparent (40 nm thick) Mo coated glass as the back contact. By modulating the electric field using a small sinusoidal potential of amplitude δV across the CIGS layer, we were able to detect the modulation ΔT of the transmitted light. This was examined as a function of photon energy, DC bias, temperature, and modulation frequency (100 Hz to 10 kHz) and had a maximum amplitude of ΔT/T ≈ 10−5 for δV = 0.3 V. Very different characteristics were obtained for near bandgap light (1.3 eV) compared to photon energies considerable smaller (<0.95 eV). While the latter exhibited a strong temperature and frequency dependence, indicating an important role for deep defects in the effect, the former exhibited very little change with temperature or frequency, indicating the predominance of transitions involving bandtail states. Different metastable states of the CIGS layer produced by prolonged light soaking above the bandgap energy were also examined.