cssi/SciSciGPT-SciSciNet huggingface dataset:
TH-D-BRC-04: Improved Dose-Image Quality Trade-Off in Cone-Beam CT by Optimization of Beam Modulation Filter Shape

Purpose: To introduce a method for optimizing the bow‐tie filter (BTF) shape in CBCT to achieve the maximum imagecontrast and minimum imagenoise relative to the patient dose. Materials and Methods: The proposed method finds the BTF shape that minimizes an objective function that accounts for dose delivered by the CBCT scan, imagenoise and contrast. The BTF shape, constant for all projections, is described by parallel translation of a curve, represented by few (4–8) drive points. The objective function combines dose and contrast‐to‐noise ratio at the central slice, reconstructed by filtered backprojection. Dose and projection data can be computed either by analytical model or by the Monte Carlo method. Nelder‐Mead optimization is used to find the set of drive point coordinates that minimizes the objective function. Results: The method was applied for two cylindrical water phantoms of diameters of 18 cm and 22 cm. The computation time for MC‐based optimization was four hours, mainly spent on MC calculations. We currently investigate how the (time‐dependent) MC statistical fluctuation affects the convergence of the process. The convergence also does not depend on the selection of the drive points that describe the BTF shape, however the convergence is not achieved when the objective function is not sensitive to location of one or more drive points. Conclusions: Our method is an important tool for improving the trade‐off between dose and image quality in CBCT. Describing the BTF shape description by a few drive points simplifies the problem and makes it solvable by a simple optimization method, while coupling the optimization code with the MC simulator gives the possibility of realistic modeling of the CBCT unit, at the expense of increased computation time. This work was supported by a research grant provided by Varian Medical Systems.
The relationship between species of RNA synthesized and levels of different DNA- dependent RNA polymerases in isolated nuclei of Rana pipiens embryos.

Abstract Experiments have been performed to investigate changes in nuclear DNA-dependent RNA polymerase during early development of Rana pipiens embryos. Nuclei were isolated from different stage embryos and incubated in the presence of either high or low ionic strength. Calf thymus or frog liver DNA was added to the incubated nuclei to serve as a template for unbound RNA polymerase. Under conditions of high ionic strength, the percent stimulation of RNA synthesis was the same at all stages studied, while under conditions of low ionic strength, there was a three-fold stimulation in RNA synthesis with added calf thymus DNA at tailbud stage when the rate of rRNA synthesis in vivo is normally high. Studies using α-amanitin confirmed that at stages synthesizing ribosomal RNA at a high rate in vivo there was a greater activity of form I RNA polymerase present in the nuclei.
Particle transport and electric fields in a laser-generated focused proton beam

Summary form only given. Recent experiments and simulations of proton generation and focusing in cone geometries have led to a better understanding of the important effects of the electric fields in and around the focused beam.1 The surrounding cone structure is shown to improve the focusing significantly, resulting in beam fluence diameters ≈ 55µm for protons with energies Ep >3 MeV. PIC-hybrid simulations predict that a strong sheath field on the inner surface of the cone wall channels the beam and results in a reduced beam diameter. The electric fields in the plasma due to the hot electron pressure also affect the focusing and particle trajectories, bending the beam near the axis. This combination of fields leads to complicated trajectories, inconsistent with simple linear acceleration near the target surface. Simulations predict that further improvement in focusing is possible by better control of the laser beam uniformity.
Evaluating the economic value of the precautionary principle: using cost benefit analysis to place a value on precaution

Abstract The assessment of environmental risks and appropriate policy action is often confounded by uncertainty, due to the complexity of environmental and human systems and their interactions. Support for precautionary action to hedge against uncertain, but potential damaging environmental risks, often appears in environmental policy, but the economic value of precaution is often difficult to evaluate. This paper proposes three ways to quantify precautionary action consistent with a cost–benefit paradigm and based on the precautionary saving model. The three proposed methods are: (1) a precautionary premium, analogous to an insurance premium; (2) a precautionary response that alters current actions to hedge against possible future negative welfare shocks; and (3) a modification to risk assessment that takes into consideration the implications of low-probability, but high-consequence outcomes for precautionary measures. An illustrative example is developed using the third method to evaluate global climate policy. Each method demonstrates that uncertainty itself imposes a penalty beyond risk aversion that stimulates an additional precautionary response to future uncertainty. The value of these applications is to place the precautionary principle on firmer economic foundations by connecting the precautionary principle criteria with cost–benefit analysis.
Coping With Job Loss: An Attributional Model

Coping strategies used by workers who have been laid off are examined in the context of attributions, particularly workers' causal attributions. Different categories of attributions are linked to subsequent strategies for coping.
Stereoscopic laparoscopy using depth information from 3D model

Laparoscopic surgery is indispensable from the current surgical procedures. Conventional laparoscope (endoscope) systems produce 2D colored video images which do not provide surgeons an actual depth perception of the scene. In this work, the problem was formulated as synthesizing a stereo image of the monocular (conventional) laparoscope image by incorporating into them the depth information from a 3D CT model. The current method was applied to the laparoscope video at the rate of up to 5 frames per second to visualize its stereo video. Correlation coefficients between the depth maps calculated with our method with those from the shape from shading algorithm were within the range of 0.70 to 0.95 (P < 0.05).
Simulation of aerosol cloud transport and diffusion with OMEGA

The Operational Multiscale Environment model with Grid Adaptivity (OMEGA) is a new atmospheric simulation system that merges state-of-the-art computational fluid dynamics techniques with a comprehensive non-hydrostatic equation set. OMEGA is based upon an unstructured triangular prism grid that permits a horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from a few tens of meters in the boundary layer to 1 km in the free troposphere. OMEGA also contains an embedded aerosol transport algorithm that permits the simulation at high resolution of the transport and diffusion of either grid-based aerosols or of Lagrangian parcels. OMEGA represents a significant advance in the field of weather prediction and aerosol transport. Current operational forecast models are scale- specific and have a limit to their resolution caused by their fixed rectangular grid structure. OMEGA, on the other hand, is naturally scale spanning and its unstructured grid permits the addition of grid elements at any point in space and time. This means that OMEGA can readily adapt its grid to fixed surface or terrain features, or dynamic features in the evolving weather. In addition, OMEGA can provide enhanced grid resolution in localized regions such as in the vicinity of a dust, smoke, or chemical cloud. The flexible grid adaptivity of OMEGA provides it with an important advantage over previous models. It permits the resolution of orographic and land/water boundary features improving the fine scale meteorological simulation and, in turn, the simulation of the aerosol transport. The coupling of a very high resolution (1 km) atmospheric simulation tool with an aerosol transport and diffusion model creates a flexible tool for a variety of applications and scales to be used anywhere that small scale features could have an impact on the local meteorology. Among these is aerosol transport in complex terrain and near land/water boundaries. In this paper, we will present an overview of the atmospheric simulation capabilities of OMEGA. We will discuss both its numerical techniques and its physics. We will also present an overview of the aerosol transport and diffusion model included in OMEGA; both its physical basis as well as its implementation on the adaptive unstructured grid that forms the basis of OMEGA. We will then discuss the application of this aerosol transport capability to the problem of simulating the transport of dust, smoke, or chemical clouds.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The growth of short fatigue cracks under compressive and/or tensile cyclic loading

Under cyclic compressive loading, fatigue cracks can initiate and propagate a short distance before being arrested. Recent studies have shown that the process of crack closure is importantly involved in the arrest process. An analytical means for dealing with this type of crack propagation is presented. Calculations based on the method of analysis compare favorably with experimental results. The method is general in nature and can also deal with short crack propagation under tension-compression and tension-tension types of loading.
Battery-ultracapacitor active parallel interface with indirect control of battery current

A battery and ultracapacitor active-parallel interface creates a power source with greater power and energy density than either source can alone. This paper explores a control scheme which allows an active-parallel interface between a battery and ultracapacitor to be implemented using one converter on the fast source only. This scheme is shown in simulation to be effective at keeping large current transients from reaching the battery, while allowing the bus voltage to float with battery state-of-charge. An analysis of the effects of loss on circuit performance is performed and guidelines for component sizing are established.
Polyclonal B cell activators and in vitro induction of auto-antibody reactive with collagen.

Cells producing autoantibodies are known to be present in chronically inflamed periodontal tissues. In sites of chronic inflammation, polyclonal B cell activators (PBA) are known to exhibit adjuvant activity when combined with foreign antigens. These results prompted an examination of PBA in eliciting an antibody response to an autoantigen (i.e. collagen type I). Rat lymphocytes were stimulated with rat collagen (type I), microbial PBA (LPS) or the combination of LPS plus rat collagen in vitro. Anti-collagen antibody-forming cells (AFC) were enumerated using an ELISPOT assay. Collagen or LPS alone elicited few anti-collagen AFC but the addition of LPS to collagen resulted in a substantial adjuvant effect and yielded maximal responses to collagen. Comparisons of anti-collagen AFC from short-term immunized (2-6 wk after booster), non-immunized and long-term immunized (3-4 months after booster) animals were performed. It revealed that cells from recently immunized rats were significantly easier to activate than the other 2 groups. The adjuvant effect of microbial PBA may be important in anti-collagen antibody production and thus the localization of PBA in periodontal pockets may explain why anti-collagen AFC are restricted to the chronically inflamed periodontal tissues.
Stress Corrosion Cracking of Candidate Material for Nuclear Waste Containers

Types 304L and 316L stainless steel (SS), Incoloy 825, Cu, Cu-30%Ni, and Cu-7%Al have been selected as candidate materials for the containment of high-level nuclear waste at the proposed Yucca Mountain Site in Nevada. The susceptibility of these materials to stress corrosion cracking has been investigated by slow-strain-rate tests (SSRTs) in water which simulates that from well J-13 (J-13 water) and is representative of the groundwater present at the Yucca Mountain site. The SSRTs were performed on specimens exposed to simulated J-13 water at 93{degree}C and at a strain rate 10{sup {minus}7} s{sup {minus}1} under crevice conditions and at a strain rate of 10{sup {minus}8} s{sup {minus}1} under both crevice and noncrevice conditions. All the tests were interrupted after nominal elongation strains of 1--4%. Examination by scanning electron microscopy showed some crack initiation in virtually all specimens. Optical microscopy of metallographically prepared transverse sections of Type 304L SS suggests that the crack depths are small (<10 {mu}m). Preliminary results suggest that a lower strain rate increases the severity of cracking of Types 304L and 316L SS, Incoloy 825, and Cu but has virtually no effect on Cu-30%Ni and Cu-7%Al. Differences in susceptibility to cracking were evaluated in terms of a stress ratio, which is defined as the ratio of the increase in stress after local yielding in the environment to the corresponding stress increase in an identical test in air, both computed at the same strain. On the basis of this stress ratio, the ranking of materials in order of increasing resistance to cracking is: Types 304L SS < 316L SS < Incoloy 825 {congruent} Cu-30%Ni < Cu {congruent} Cu-7%Al. 9 refs., 12 figs., 7 tabs.
Fixed point theorems for semidifferentiable k-set-contractions in ordered Banach spaces

Soit X un espace de Banach reel, K un cone dans X, et «≤» un ordre dans X induit par K en definissant y≥x si et seulement si y−x∈K. La paire (X,K) est appelee un espace de Banach ordonne avec cone positif K si X est d'ordre donne induit par K. On etend certains theoremes de point fixe pour des contractions ensemble T:K→K qui sont differentiables de Frechet en 0 et/ou a l'infini
Effect of chitosan on lingual hemostasis in rabbits with platelet dysfunction induced by epoprostenol.

Abstract Chitosan, a complex carbohydrate derivative of shellfish exoskeleton, is shown to enhance lingual hemostasis in rabbits treated with a known antagonist of platelet function, epoprostenol (prostacyclin or PGI2). Bleeding times were measured for bilateral (15 mm × 2 mm) tongue incisions in 10 New Zealand white rabbits. Using a randomized, blinded experimental design, one incision in each animal was treated with chitosan and the other was treated with control vehicle without chitosan. Extraoral bleeding and coagulation times were measured for each animal before, during, and after infusion of epoprostenol. Continuous infusion of epoprostenol increased mean systemic bleeding time 95%. In this platelet dysfunction animal model, lingual incisions receiving the experimental substance showed a 56% improvement in bleeding time in comparison with lingual incisions receiving control solution (P = .003).
Late Na currents affected by α subunit isoform and β1 subunit co-expression in HEK293 cells

Peak Na current underlies excitability and conduction in the heart, and late non-inactivating or slowly inactivating Na current plays a role in action potential duration. We hypothesized that different alpha subunit isoforms or beta1 subunit co-expression might affect late Na current. The human Na channel alpha subunits hNa(v)1.5 (hH1a) and hNa(v)1.4 (hSkM1) were transfected with and without the hNa(V)beta1 (beta1) subunit in HEK293 cells and studied by whole cell patch clamp. The inactivation relationship for hH1a was 28mV negative to that for hSkM1, and beta1 shifted the midpoint positively by 22mV for hH1a and 8mV for hSkM1. When pre-pulse duration was varied from 10ms to 10s, "steady-state" was approached more slowly for hH1a. beta1 caused hH1a but not hSkM1 to reach "steady-state" earlier. Both isoforms showed two recovery components but hH1a showed a "cardiac phenotype" with a smaller slow component that was unaffected by beta1. The amplitude of a late current (at 750ms) was significantly greater for hH1a than hSkM1, but beta1 decreased late current for hH1a and eliminated the difference. Under the study conditions the alpha subunit isoforms have distinct functional phenotypes and co-expression with beta1 tends to diminish these distinctions. These properties may provide mechanisms for regional and transmural distribution of late Na current and late Na current amplitudes during development and in disease states.
A comparison of gradient dependent techniques for the minimization of an unconstrained function of several variables

Minimization of unconstrained function of several variables by gradient dependent techniques, discussing applications to boundary value problems in optimal control
POES companion: Objectives, methodology, and benefits

Abstract POES Companion is a small satellite that would carry an atmospheric sounding instrument identical to one on a nearby operational polar orbiting spacecraft. The spacing between the two satellites would be controlled and variable. The mission is designed to establish the upper bound on the distance between the two satellites within which data from the instruments are statistically equivalent, and further would demonstrate that two neighboring spacecraft can be managed safely and efficiently. POES Companion will validate new Companion options outlined in this paper that could substantially reduce costs attributable to satellite-based atmospheric sounders for both operational and research programs.
Development of a Conceptual Structure for Aquatic Education and Its Application to Existing Aquatic Curricula and Needed Curriculum Development.

(1984). Development of a Conceptual Structure for Aquatic Education and its Application to Existing Aquatic Curricula and Needed Curriculum Development. The Journal of Environmental Education: Vol. 15, No. 2, pp. 12-16.
Effects of Defects and Impurities in Starting Material on Radiation Hardness of CMOS/SOS Devices

Some of the relationships between defects and impurities in SOS starting materials and the radiation hardness of CMOS/SOS devices have been investigated. It is shown that a direct correlation exists between contaminants in the epitaxial silicon film and the radiation-induced back-channel leakage currents. Radiation-induced shifts in device threshold voltage were observed, but these shifts appeared to be more closely related to variations in device processing than to silicon film contamination.
Bone, bones and biomechanics

The Mechanical Adaptations of Bones. By John Currey. Princeton University Press: 1984. Pp.294. 37.50, 37.20.
ELEVATED CO2 DIFFERENTIATES ECOSYSTEM CARBON PROCESSES: DECONVOLUTION ANALYSIS OF DUKE FOREST FACE DATA

Quantification of the flux of carbon (C) through different pathways is critical to predict the impact of global change on terrestrial ecosystems. Past research has en- countered considerable difficulty in separating root exudation, root turnover rate, and other belowground C fluxes as affected by elevated CO2. In this study we adopted a deconvolution analysis to differentiate C flux pathways in forest soils and to quantify the flux through those pathways. We first conducted forward analysis using a terrestrial-C sequestration (TCS) model to generate four alternative patterns of convolved responses of soil surface respiration to a step increase in atmospheric CC)2. The model was then validated against measured soil respiration at ambient CO2 before it was used to deconvolve the CO2 stim- ulation of soil respiration. Deconvolved data from the Duke Forest free-air CO2 enrichment (FACE) experiment suggest that fast C transfer processes, e.g., root exudation, are of minor importance in the ecosystem C cycling in the Duke Forest and were not affected by elevated CO2. The analysis indicates that the fine-root turnover is a major process adding C to the rhizosphere. This C has a residence time of several months to -2 yr and increases signif- icantly with increased CO2. In addition, the observed phase shift in soil respiration caused by elevated CO2 can be only reproduced by incorporation of a partial time delay function in C fluxes into the model. This paper also provides a detailed explanation of deconvolution analysis, since it is a relatively new research technique in ecology.
Distribution of lumbar afferent axons in muscle coat of cat urinary bladder

Lumbar spinal ganglia, L2,3,4 were ablated in four cats to determine the distribution of degenerating lumbar afferents in the urinary bladder. Bladders were collected at 7, 14, 21 and 35 days following ganglionectomy. Six regions of the urinary bladder were sampled bilaterally and examined ultrastructurally in each cat. Overall, 3,033 terminal axons were counted, of which 2.6% were degenerating; of these, 9% had synaptic vesicles and were interpreted as efferent axons of postganglionic neurons with cell bodies in spinal ganglia. Lumbar afferents were most numerous in the trigone region, followed next by the ventral neck region; regions cranial to the ureters had similar small populations of lumbar afferents. A similar distribution pattern was observed for terminal axons containing granular synaptic vesicles. The relative concentration of lumbar innervation caudal to the ureters seems to account for the increased density of terminal axons observed in this region. Lumbar afferents were distributed bilaterally to the bladder and were numerically similar within and outside muscle fascicles. Ultrastructural evidence supports the position that bladder receptors are free nerve endings except for sparse Pacinian corpuscles.
A Search for a Sodium Atmosphere around Ganymede

Long-slit high-resolution spectra have revealed that Ganymede has an atmospheric sodium column density, between a distance of 7800 and 15600 km from the satellite surface, of less than 1 × 10^8 atoms cm^(−2), a factor of 13 times smaller than the sodium density in the atmosphere of Europa at the same distance. Assuming similar processes creating sodium on both Europa and Ganymede, we estimate that the source rate for sodium production on Ganymede should be within a factor of 2 of that on Europa. Two possibilities for the lack of detectable sodium around Ganymede are that Ganymede's surface is depleted in native sodium compared to Europa's or that Ganymede has a magnetic field capable of standing off impacting energetic particles.
Abstract B36: Respiratory symptoms after smoking cessation among college students

Introduction: Data about respiratory symptoms and lung function are available for middle-aged adults post-cessation. Similar evidence is lacking for those aged 18 to 24 years. This study addresses that gap. Procedures: This report is a secondary analysis of data derived from two randomized controlled smoking cessation trials among a subset of 18- to 24-year-old college students. Data from both studies were combined regardless of treatment condition. Some participants received an active intervention while controls were provided with self-help smoking materials. Self-reported respiratory symptoms were longitudinally analyzed in 273 quitters. The change in respiratory symptoms was calculated by subtracting the final scores from those at baseline. Summary of Data: The respiratory symptoms of continued smokers were compared to the quitters at the final visit using t-tests. Significant improvements in respiratory symptoms were found among quitters for morning cough, (p =.002) daytime cough, (p =.007), and chest pain (p =.007). Statement of Conclusions: Young individuals rarely respond to quit-smoking motivation based on long-term health consequences, such as risk of tobacco-attributable cancers. A more appropriate motivational strategy for young adults appears to be emphasizing the existing respiratory symptoms caused by smoking. Clinicians are encouraged to detect and discuss respiratory symptoms with their young tobacco-using patients as a part of smoking cessation counseling and treatment. Highlighting post-cessation reduction in these symptoms is likely to reinforce continued abstinence. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B36.
A strategy to decide whether to move the last case of the day in an operating room to another empty operating room to decrease overtime labor costs.

UNLABELLED We examined how to program an operating room (OR) information system to assist the OR manager in deciding whether to move the last case of the day in one OR to another OR that is empty to decrease overtime labor costs. We first developed a statistical strategy to predict whether moving the case would decrease overtime labor costs for first shift nurses and anesthesia providers. The strategy was based on using historical case duration data stored in a surgical services information system. Second, we estimated the incremental overtime labor costs achieved if our strategy was used for moving cases versus movement of cases by an OR manager who knew in advance exactly how long each case would last. We found that if our strategy was used to decide whether to move cases, then depending on parameter values, only 2.0 to 4.3 more min of overtime would be required per case than if the OR manager had perfect retrospective knowledge of case durations. The use of other information technologies to assist in the decision of whether to move a case, such as real-time patient tracking information systems, closed-circuit cameras, or graphical airport-style displays can, on average, reduce overtime by no more than only 2 to 4 min per case that can be moved. IMPLICATIONS The use of other information technologies to assist in the decision of whether to move a case, such as real-time patient tracking information systems, closed-circuit cameras, or graphical airport-style displays, can, on average, reduce overtime by no more than only 2 to 4 min per case that can be moved.
Analysis of large LNG spills on water part 1: Liquid spread and evaporation

Abstract The first part of this two-part review considers the theoretical and experimental results obtained on liquid spread and evaporation on large LNG spills on water. Both instantaneous spills, in which the spill time is much smaller than the time for complete vaporization, and continuous spills are considered. Also applications of the correlations are discussed.
The detection of the 2π* orbital of CO and NO chemisorbed on Ni(111) by surface penning ionization electron spectroscopy

Abstract We use surface Penning ionization spectroscopy (SPIES) to study the electronic properties of CO and NO adsorbed on Ni(111). In this experiment an atomic beam containing ground-state and 2 1 S He atoms collides with the adsorbate covered Ni(111) surface. This causes the transfer of ≈20.6 eV energy into the electronic degrees of freedom of the adsorbate molecules, forcing them to emit electrons. The SPIE spectrum is obtained by analysing the energy of these electrons. The high surface sensitivity of this method allows us to measure the binding energy of the partly filled 2π* orbitals of CO and NO.
Local Solvability Of First Order Differential Operators Near A Critical Point, Operators With Quadratic Symbols And The Heisenberg Group

We study questions of solvability for operators of the form p(x,D)+b, where p(x,ξ) is a real quadratic form and b∊C. As one consequence, we obtain a necessary and sufficient condition for the local solvability of operators of the form L= near the critical point x=0, and prove the existence of tempered fundamental solutions whenever L is locally solvable.Our analysis of these operators is largely based on recent results about the solvabilitiy of left–invariant second order differential operators on the Heisenberg group and a transference principle for the Schrodinger representation.
Preliminary SMOS Salinity Measurements and Validation in the Indian Ocean

Global sea surface salinity (SSS) measurements retrieved from the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission are the first highest resolution salinity data available from space. There are many challenges to measuring salinity from space and obtaining a targeted accuracy of 0.1 psu. Comparisons of Level 2 (L2) SMOS SSS data with the 1/12° high resolution HYbrid Coordinate Ocean Model (HYCOM) simulations of SSS reveal large differences. These differences are minimized for an extent during the creation of Level 3 (L3) SMOS data through spatial and temporal averaging. Depending on the retrieval algorithm used, there are differences between ascending and descending passes with data collected during the descending pass exhibiting a bias toward lower SSS. It is challenging to process SMOS SSS data in the northern Indian Ocean due to radio frequency interference and large seasonal variability due to monsoonal circulation. Comparisons of SMOS L3 data with Argo float SSS and HYCOM SSS indicate the lowest discrepancies in SSS for these data sets occur in the southern tropical Indian Ocean and the largest differences between the compared salinity products are noticed in the Arabian Sea and Bay of Bengal with an erratic root mean square error in the latter region. Higher errors in SSS occurred in coastal areas compared to the open ocean. The accuracy of SMOS salinity measurements is increasing with the maturity of the data and new algorithms.
Wigner function studies of spin transport in dilute magnetic semiconductor barrier structures

The spin dependent Wigner function is implemented to obtain the IV characteristics of a double barrier resonant tunneling diode with DMS layers. The structure distinguishes between spin-up and spin-down carriers, each of which experiences resonance at different magnetic field dependent bias levels. The results demonstrate the magnetic field dependence of the IV characteristics and illustrate the magnetic field dependence of relative spin-up and spin-down carriers.
Lion-tailed macaques (Macaca silenus) manufacture and use tools

Lion-tailed macaques (Macaca silenus) in captive social groups spontaneously manufactured and used tools to extract syrup from an apparatus that was designed to accommodate probing behavior. An attempt to replicate these findings with mandrills (Mandrillus sphinx) was unsuccessful. This report is the first to describe spontaneous manufacture of tools in any group of Old World monkeys and provides evidence of greater continuity among primates for the expression of complex cognitive abilities. These data are consistent with hypotheses that lion-tailed macaques have extensive propensities for advanced sensorimotor skills and that omnivorous, extractive foraging is associated with the manufacture and use of tools. I present a proximate model that integrates sensorimotor and social factors to account for diverse expression of tool-related behavior.
Stimulus number, duration and intensity encoding in randomly connected attractor networks with synaptic depression

Randomly connected recurrent networks of excitatory groups of neurons can possess a multitude of attractor states. When the internal excitatory synapses of these networks are depressing, the attractor states can be destabilized with increasing input. This leads to an itinerancy, where with either repeated transient stimuli, or increasing duration of a single stimulus, the network activity advances through sequences of attractor states. We find that the resulting network state, which persists beyond stimulus offset, can encode the number of stimuli presented via a distributed representation of neural activity with non-monotonic tuning curves for most neurons. Increased duration of a single stimulus is encoded via different distributed representations, so unlike an integrator, the network distinguishes separate successive presentations of a short stimulus from a single presentation of a longer stimulus with equal total duration. Moreover, different amplitudes of stimulus cause new, distinct activity patterns, such that changes in stimulus number, duration and amplitude can be distinguished from each other. These properties of the network depend on dynamic depressing synapses, as they disappear if synapses are static. Thus, short-term synaptic depression allows a network to store separately the different dynamic properties of a spatially constant stimulus.
Inner city leisure resources

Research into urban leisure is a response to various developments: more free time, the revaluation of urban areas, changing characteristics of the urban population and awareness of unused leisure resources. Dutch leisure policy features both sector planning and facet planning. Leisure opportunities in inner cities are based on a variety of facilities: the catering sector, shopping, tourist facilities and historical elements. In recent tourist overall recreational plans the inner city is treated as a leisure product. A further evaluation of inner-city leisure resources is required, especially in historic smaller towns. Several case studies indicate the line of research to be pursued, although a theoretical framework is lacking.
Exploring Candidate Gene Associations With Neuropsychological Performance

We hypothesize that quantitative phenotypes related to Alzheimer's disease (AD), rather than the dichotomous disease phenotype, will increase the statistical power for identifying genetic risk factors. Neuropsychological test scores, which allow for the measurement of loss of cognitive function over time, are a particularly promising option for this approach. Using data from a cohort study of prodromal AD in 365 community-recruited subjects with and without memory problems with a baseline and often one or more follow-up administrations of a detailed neuropsychological test battery, we performed both cross-sectional and longitudinal analyses using the known AD gene APOE and four other putative AD genes as predictors. APOE and a promoter polymorphism in insulin degrading enzyme (IDE_4U) showed evidence for association with cross-sectional and longitudinal changes in memory (P = 0.016-0.025) and other cognitive functions. APOE and a polymorphism in the alpha-2-macroglobulin gene (A2M18i) also showed evidence for association with cross-sectional and longitudinal changes in executive functioning (P = 0.010-0.042). In some cases, longitudinal analysis offered stronger evidence for association than could be seen cross-sectionally. These preliminary results suggest that this approach has promised the development of a quantitative phenotype related to AD, but more elaborate methods will be required to address multiple comparisons issues in the setting of correlated data.
A simple asset pricing model with social interactions and heterogeneous beliefs

Abstract This paper investigates the dynamics of a simple present value asset pricing model with social interactions and heterogeneous beliefs. Investors revise their beliefs in each period according to two features: the ‘fitness measure’ which is the past realized profit and the exogenous ‘social interactions measure’ which is the interaction among traders’ expectations of the mean choice level in the economy. The endogenous type of social interactions arises naturally when there exist both exogenous social interactions and heterogeneous beliefs among traders. Furthermore, it is shown that the characteristics of the steady state and the dynamic behavior of asset prices are mainly determined by the strength of the endogenous type of social interactions.
The Power of Personal Narratives in Illuminating Political Struggles

they fare less well when subjected to the scrutiny of sociological thinking. For all their good intentions in honoring these "good white men," the authors end up uncritically adapting "white men" as a pre-constructed category: a category of practice becomes a category of analysis (or, actually, a criteria for selecting who to interview and why). The authors thus miss a chance to actually explain how and why "race" is constructed both as an analytical category and as a principle of domination. On the "story" side of the book, something should be said about the authors' use of narratives. For a while now, sociologists have been acknowledging that narratives present certain kinds of problems to our craft. The main problem with the stories of "white men challenging racism" is not that they are bound to be romantic (as many a reader might suspect), but that as stories, they are, as Charles Tilly (1998) boldly states, "execrable guides for sociological explanation." The profiles presented in this book illustrate what Tilly would call "standard stories," that is "the sequential, explanatory accounts of self-motivated human action." As
An analysis of the placebo phenomenon.

Abstract Any change in a patient's signs or symptoms which is the result of the therapeutic intent, and not the specific physico-chemical nature, of a medical procedure can be called a placebo effect. The history of the placebo effect extends from the pre-Christian era when Egyptian doctors found their patients improved after giving them lizard's blood to drink to the present day finding of relief of pain and anxiety after sugar pills or saline injections. Although several investigations have shown that certain people react to placebos repeatedly under the same laboratory or clinical situation, no study has been made to test for consistent reactions under different experimental situations. Thus the question of whether or not placebo reactivity is bound to definable therapeutic situations has not been answered. In this paper, the placebo phenomenon is conceived as being a resultant of four major groups of factors: (1) the observable doctor-patient therapeutic situation which includes the attitudes and behavior of the doctor, the physical environment (hospital versus home), and the type of treatment, (2) the predispositions of the patient such as attitudes toward doctors and medicines, self-esteem and need for social approval, authoritarian and dependency tendencies, and anticipatory ability, (3) the patient's ‘internal mediating processes’ of attention, comprehension, evaluation, and acceptance which interact with the therapeutic stimuli and the predispositions to produce (4), the observed placebo effect. Future research should aim at better understanding of the etiology and dynamics of the placebo effect by controlled experimentation involving the above four categories. The many operative variables which affect placebo responsiveness must be held constant or at least quantitated when assessing the relative importance of the one variable under study. Experiments must also eliminate spurious placebo effects such as the spontaneous appearance or disappearance of signs and symptoms and ‘faking’ responses by the patient or experimental subject.
Problems Associated With Prolonged Wear Soft Contact Lenses

Complications of prolonged wearing of soft contact lenses are corneal infection, peripheral vascularization, giant papillary conjunctivitis and allergy, sterile ulcers, corneal warping, lens infection, protein and calcium deposits, lens fragility, and problems with disinfecting solutions. Further long-term studies are needed to compare the safety of prolonged wear soft contact lenses with the safety of intraocular lenses, on which long-term studies are currently being done.
Levodopa pharmacokinetic mechanisms and motor fluctuations in Parkinson's disease

The contribution of the peripheral and central pharmacokinetic mechanisms of levodopa to the pathogenesis of the motor fluctuations that complicate its long-term administration was studied in 28 parkinsonian patients. The rate of levodopa clearance from the general circulation, its plasma half-life, and apparent volume of distribution were indistinguishable between patients with the on-off or the wearing-off phenomenon and those with a stable response to levodopa or those who had not been previously treated with levodopa. Peripheral pharmacokinetic factors are thus unlikely to account for the development of these response fluctuations. Conversely, the efficacy half-time of levodopa differed markedly among the four response groups studied and may provide a quantitative index of central mechanisms that favor the development of the wearing-off and on-off phemonena. Although symptom duration was the best predictor of the severity of untreated parkinsonism, levodopa dose correlated best with response half-time. The wearing-off phenomenon may primarily reflect the loss of buffering capacity caused by degeneration of the dopamine neurons, while the development of the on-off phenomenon appears to require additional postsynaptic changes, possibly at the receptor level.
Postoperative pain relief following laparoscopic tubal sterilization with silastic bands.

Objective To evaluate postoperative pain relief of intramuscular ketorolac, topical bupivacaine, and placebo in patients undergoing laparoscopic tubal sterilization with silastic bands. Methods One hundred five women undergoing laparoscopic tubal sterilization with silastic bands were randomized to one of three groups: one received intramuscular ketorolac and topical placebo applied to the fallopian tubes, the second received intramuscular placebo and topical bupivacaine, and the third received intramuscular placebo and topical placebo. Surgical procedures, anesthesia, and recovery were conducted with standardized protocols. Postoperative pain perception was graded using the modified McGill pain intensity scale at 30 minutes postoperatively, at discharge from the recovery room, and the next morning by telephone interview. Other measured variables included postoperative vomiting, additional analgesia requirement, and length of time spent in the recovery room. Results Only topical bupivacaine was found to decrease postoperative pain scores significantly over those with placebo, at 30 minutes postoperatively (median score 2 compared with 4, P = .002) and at discharge from the recovery room (median score 2 compared with 3, P = .03). There was no significant decrease in pain scores with intramuscular ketorolac compared with placebo. No differences in pain scores were found between the three groups at the next morning phone call. There were no significant differences between the three groups with respect to requirements for supplemental pain medications in the recovery room, incidence of postoperative vomiting, or length of time spent in the recovery room. Conclusion Topical bupivacaine decreases postoperative pain scores significantly compared with placebo in women undergoing laparoscopic tubal sterilization with silastic bands.
Metabolic Status and Growth Hormone Secretion in Man

The metabolic state influences GH secretion and, in turn, GH secretion influences overall body metabolism. While these are distinct physiological entities, separation of these interrelated phenomena should be considered artificial since the overall result is an organism which retains functional capacity in the setting of a variety of circumstances.
Computer simulation of gates for ion-implanted devices

A computer simulator has been constructed which can be used to model the operation of current-activated gates used in ion-implanted magnetic bubble devices. Input parameters for the simulator include the geometry of the implanted patterns, magnetic characteristics of the bubble film, implanted layer thickness, conductor geometry, amplitude and phase of currents in conductors, and the frequency and amplitude of the drive field. The forces that act on the bubble are computed, and the resultant bubble wall motion is computed. The operation of various gates for ion-implanted devices has been analyzed. Simulation of propagation on ion-implanted patterns has been performed, and the predicted failure modes are the same as those observed in experimental devices. The simulated bias margins of both propagation and gate operation correspond well with experimentally obtained margins. >
Compact Coherent Light Valve Processor

The coherent light valve (CLV) processor is a video input signal processor which employs a CLV tube as a two-dimensional optical modulator . This CLV tube is a modified version of one used in a commercial General Electric TV Video Display Projector. CLV optical processors have been used for some time for wideband spectrum analysis and other specialized signal processing operations. They can provide large time-bandwidth processing with a 200 Hz or less spectral resolution over a 10 to 20 MHz bandwidth. Processor configurations range from the usual optical bench and optical table installations to electronic enclosures. Continued work has been directed to a system configuration more suited to the user environment. This paper discusses a current project development, termed the compact CLV Processor. In this configuration the processor is packaged to fit into a standard relay rack, almost the size of the present CLV projector unit. This configuration and extended versions will be described.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Réflexions sur la réflexivité théâtrale

Narcissique, le theâtre exhibe toujours son fonctionnement. Phenomene le plus abouti de metatheâtralite, le « theâtre dans le theâtre » est loin de constituer la seule manifestation d’ostension theâtrale. Si on considere le theâtre dans sa traditionnelle analogie avec le tableau, et en empruntant aux analyses de Louis Marin concernant le fond, le plan et le cadre (De la representation), on constate que ces marqueurs de reflexivite ne sont pas specifiques a la peinture, mais qu’ils s’appliquent aussi au texte spectaculaire. Objet regardant et regard sur cet objet, le theâtre est doue d’un double regard sur le monde et sur l’art dramatique. Loin que ces regards divergents perturbent la vision, ils la rendent au contraire beaucoup plus percante. Reflechi comme fait, le theâtre ne cesse pas de representer comme signe et, a l’instar de la fonctionnalite de celui-ci, fait de la reflexivite a la fois une irremediable necessite et une vertu admirable.
Extreme landscapes of leisure: not a hap-hazardous sport

Extreme landscapes of leisure: not a hap-hazardous sport, by Patrick Laviolette, Surrey, England, Ashgate Publishing, 2010, 226 pp., £50.00 (hardback), ISBN 978-0-7546-7958-5 Few academic books on ...
Extensions of the Ostrowski-Reich theorem for SOR iterations

Abstract The Ostrowski-Reich theorem states that for a system Ax =b of linear equations with A nonsingular, if A is hermitian and if the diagonal of A is positive, then the SOR method converges for each relaxation parameter in (0,2) if and only if A is positive definite. This is actually a special case of the Householder-John theorem, which states that for A=M−N with A,M nonsingular, if A is hermitian and M ∗ +N is positive definite, then M−1N is a convergent matrix if and only if A is positive definite. Our purposes here are to generalize the Householder-John theorem and to provide an insight into how and why the SOR method can converge. As a result the Ostrowski-Reich theorem is extended in two directions; one is when A is hermitian but the diagonal of A is not necessarily positive, so that A is not necessarily positive definite, and the other is when A+A ∗ is positive definite but A is not necessarily hermitian. In the process, several other convergence results are obtained for general splittings of A. However, no claims are made concerning the case in which the convergence results obtained here can be applied to practical situations.
Role of wheat root exudates in associative nitrogen fixation.

Abstract Root exudates and related exudate diffusion gradients were studied using 14C-radioisotope techniques. With inoculated wheat plants (Triticum aestivum cv. Nugaines), 3.7% of the 14C-labeled photosynthate was released as soluble exudate whereas 3.0% was found with axenic plants. Root surface areas averaged 54 cm2 plant−1. The microbial cells produced were sufficient to colonize 7.4%, of the root surface with a cell monolayer. Gradient studies showed that with inoculated root systems, rapid utilization of soluble exudate markedly decreased the distance of exudate diffusion. Microbial colonization also was a function of the physiological features of the test culture. The relationship between root colonization, exudate production and potential for associative nitrogen fixation is discussed.