cssi/SciSciGPT-SciSciNet huggingface dataset:
Flexural fatigue failures and lives of Eco-Core sandwich beams

Abstract Eco-Core is a class of syntactic foam made from small volume of high char yield binder and large volume of a class of flyash for fire resistance application. Very little or no flexural fatigue data of this class of core material is reported in the open literature. This paper presents a flexural fatigue response of Eco-Core in a glass/vinyl ester composite face sheet sandwich beam. A four-point loaded flexural test specimen was designed and tested in static and fatigue loadings to cause tension failure in the core. The fatigue test was conducted at maximum cyclic stress ( σ max ) ranged from 0.7 σ ct to 0.9 σ ct , where σ ct is the static flexural strength of the core. The sinusoidal loading frequency of 2 Hz with the stress ratio of 0.1 was used. Flexural fatigue failure modes of Eco-Core sandwich beam were classified: damage onset (single tension crack), damage progression (multiple tension cracks) and ultimate failure (a combination of tension and shear). These failures were characterized by 1%, 5% and 7% changes in compliance that corresponds to N 1% , N 5% and N 7% lives. The fatigue stress-life (S–N) relationship was found to follow the well-known power law equation, σ max / σ ct = A o N α . The constants A o and α were established for all three types of failures. The endurance limit was established based on 1 million cycles limit and it was found to be 0.65 σ ct , 0.70 σ ct and 0.71 σ ct , respectively for the three modes of failure. Flexural fatigue and static failure modes of Eco-Core sandwich beams were similar.
Computational methods for transcriptional regulation.

How is the information from a thousand gene-expression arrays, the location of more than two hundred regulatory factors, and nine sequenced genomes to be integrated into a global view of the regulatory network in budding yeast? Computational methods that fit incomplete noisy data provide the outlines of regulatory pathways, but the errors are not quantified. In the fly, embryonic patterning has proved amenable to computational prediction, but only when the DNA-binding preferences of the relevant factors are taken into account. In both these model organisms, simply restricting attention to regulatory sequences that align with related species (i.e. ‘conserved’) discards much information regarding what is functional.
Fleas from the archaeological site at Lovelock Cave, Nevada (Siphonaptera)

Adults of Ceratophyllus petrochelidoni and C. celsus, which parasitize Petrochelidon pyrrhonota, and flea larvae were found at 2 levels within bat guano in Lovelock Cave, Nevada, a site occupied by prehistoric man. The older level has been dated by radiocarbon analysis as 4570 ± 110 Before Present. Requirements necessary for maintenance of a nesting colony and probable effects of human occupation on the colony are discussed.
Large-scale rotating filter perfusion system for high-density growth of mammalian suspension cultures.

A system has been developed for growth and maintenance of mammalian cells in suspension culture at high density. In principle, the maintenance of constant levels of required nutrients coupled with the removal of toxic cell byproducts can support much higher suspension cell densities than may be obtained in conventional spinners. The system consisted of 4- or 40-liter reaction vessels equipped with a vertically supported rotating cylindrical filter. Agitation was provided by the magnetically driven, rotating filter. Fresh medium was supplied at a rate of 10 to 20 ml/h per 109 cells and the expended medium free of cells was withdrawn through the rotating filter. Both pH and dissolved O2 and CO2 were monitored and regulated. Walker 256 carcinosarcoma cells have been grown in these reactors to densities 10-to 30-fold greater than that obtained in Bellco spinners. In addition to high cell densities, the yield of cells per liter of medium used was 2- to 3-fold that obtained in the conventional systems. Both 4-and 40-liter versions of this reactor have been operated without the use of antibiotics. The 40-liter reactor also has been modified for chemostat operation. In a single run, for example, the Walker cell density was maintained between 6 and 10×106 cells/ml with a total yield of 8.7×1011 cells from 360 liters of medium.
Neurexins Induce Differentiation of GABA and Glutamate Postsynaptic Specializations via Neuroligins

Formation of synaptic connections requires alignment of neurotransmitter receptors on postsynaptic dendrites opposite matching transmitter release sites on presynaptic axons. β-neurexins and neuroligins form a trans-synaptic link at glutamate synapses. We show here that neurexin alone is sufficient to induce glutamate postsynaptic differentiation in contacting dendrites. Surprisingly, neurexin also induces GABA postsynaptic differentiation. Conversely, neuroligins induce presynaptic differentiation in both glutamate and GABA axons. Whereas neuroligins-1, -3, and -4 localize to glutamate postsynaptic sites, neuroligin-2 localizes primarily to GABA synapses. Direct aggregation of neuroligins reveals a linkage of neuroligin-2 to GABA and glutamate postsynaptic proteins, but the other neuroligins only to glutamate postsynaptic proteins. Furthermore, mislocalized expression of neuroligin-2 disperses postsynaptic proteins and disrupts synaptic transmission. Our findings indicate that the neurexin-neuroligin link is a core component mediating both GABAergic and glutamatergic synaptogenesis, and differences in isoform localization and binding affinities may contribute to appropriate differentiation and specificity.
A new approach to Mueller matrix reconstruction of skin cancer lesions using a dual rotating retarder polarimeter

The Mueller matrix is an elegant mathematical method to fully characterize the polarization properties of an object. If the Mueller matrix of an optical element is known as well as the polarization of an incident beam (and its Stokes vector) then the polarization state of the beam exiting the optical element can be uniquely determined. Over the last thirty years, several polarimeters have been proposed for reconstructing the Mueller matrix of any optical element through a set of measurements. One the most successful polarimeters is the dual rotating retarder polarimeter (DRR), invented by Azzam in 1978. This system is composed of two polarizer and retarder pairs, and is able to reconstruct the Mueller matrix of an object inserted in between the two polarizing pairs via an angular modulation of the retarders. Chenault et al. in 1992 suggested that the Mueller matrix of a sample inserted in a DRR polarimeter could be calculated multiplying the pseudo-inverse of a data reduction matrix by the measurements vector. The pseudo-inverse of the data reduction matrix is calculated with a least-square approach. This method is now of common usage in the scientific community. In this paper we will show that the reconstruction of the Mueller matrix can be done with higher accuracy using singular value decomposition of the data reduction equation. Our method suggests that a vast range of retardations for the retarders of a DRR obtaining identical results and not only the 127° one as recently suggested by few authors.
Water adsorption at a polyimide/silicon wafer interface

Neutron reflectivity (NR) was applied to measure the concentration of water at the buried interfaces between an amorphous polyimide and silicon single crystal wafers. Excess water was discovered within 30 A of the metal/polymer interface, where the water concentration reached 17% (by volume) for the samples without a coupling agent and 12% for the ones with coupling agent. Beyond the interface, the water concentration was measured at 2 to 3%, which is typical of bulk polyimide. The above results demonstrate conclusively the unique power of NR in determining water concentration near a buried interface, and provide the first quantitative evidence for a water concentration profile which peaks in the interface region.
Crisis Intervention Team (CIT) Training: Selection Effects and Long-Term Changes in Perceptions of Mental Illness and Community Preparedness

Survey data were used to assess how training affects changes in officers’ perceptions of persons with mental illness as well as perceptions of police and the mental health system's preparedness in addressing their needs. Officers’ confidence in their ability to handle calls involving people with mental illness in crisis increased most over time. Exploratory analysis indicated that this increase was positively associated with the pretraining degree to which people with mental illness in crisis present a problem for the police department. This increase was positively associated with the perception that the police department's overall effectiveness in meeting the needs of people with mental illness in crisis and negatively associated with the degree to which mental illness was believed to be caused by parental upbringing. These findings suggest that initial salience of the problem for the police department posed by those with mental illness is critical to CIT officer eventual “success.”
Delayed acute toxicity of O,S,S-trimethyl phosphorodithioate and O,O,S-trimethyl phosphorothioate to the rat

Abstract The toxicity and LD 50 of O,S,S -trimethyl phosphorodithioate were reexamined in the rat. Animals treated orally (single dose) with this compound exhibited early cholinergic signs followed at approximately 5 hr by delayed toxic signs, with an LD 50 of 43 mg/kg. Contamination of O,S,S -trimethyl phosphorodithioate by as much as 5% (w/w) O,O,O -trimethyl phosphorothioate provided only limited antagonism to the dithioate's toxicity. In contrast, the addition of 5% O,O,S -trimethyl phosphorodithioate to O,O,S -trimethyl phosphorothioate gave protection against the toxic effects of the latter compound up to 80 mg/kg of toxicant. Pretreatment of rats with as little as 5% O,O,O -trimethyl phosphorothioate, 24 hr prior to treatment with 200 mg/kg O,O,S -trimethyl phosphorothioate, gave complete protection against the toxic effects of this compound. Conversely, administration of 10% (w/w) O,O,O -trimethyl phosphorothioate 4 or 24 hr after treatment with 60 or 80 mg/kg of O,O,S -trimethyl phosphorothioate provided only partial protection at 4 hr and no protection from the effects of the toxicant at 24 hr. The ability of O,O,O -trimethyl phosphorothioate to antagonize the toxicity of this compound depended markedly on the route of administration (oral, intravenous, or intraperitoneal). At 4 hr past treatment with toxicant, only oral administration of the antagonist provided full protection. Intraperitoneal and intravenous administration of antagonist 4 hr after treatment with toxicant were partially effective and completely ineffective, respectively, in halting the toxic effects of this compound.
Glass foams: formation, transport properties, and heat, mass, and radiation transfer

Abstract Energy efficiency, environmental impact, and quality of the final product in glass manufacturing depend, to a large extent, on foams formed on the surface of the molten glass and of the batch due to entrapment of gas bubbles generated by the batch fusion and refining chemical reactions during the melting process. Hence, understanding the mechanisms of foam formation as well as development of theoretical models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams are not only a problem of significant fundamental interest but also of tremendous practical impact. In this paper, the review of the current state-of-the-art in our understanding of glass foams is provided, including some of our recent results in modeling the dynamics of the foam growth and its steady-state thickness, prediction of gas diffusion through glass foams, and thermal radiative properties of glass foams. In addition, the new results on simulation of combined conduction and radiation heat transfer in glass foams and radiative transfer in primary (batch) foams are presented and discussed in some detail. The paper also presents practical means available for reducing foaming in glass melting and concludes with the discussion of unresolved problems and summary of the directions for the future work in the area.
High-fat diets suppress cd3 and cd25 expression on the surface of murine lymphocytes

To determine the effects of dietary fats on surface antigen expression, we tested the effects of amount and type of dietary fat on murine lymphocytes. Mice were fed diets with 12 en%, 23 en%, or 47 en% fat containing coconut, olive, safflower, or linseed oil. After 2 wk of ad libitum feeding, the mice were killed and splenic lymphocytes were harvested. Lymphocytes were incubated with fluorescent-tagged monoclonal antibodies and assayed for mean and total surface expression using flow cytometry. Our results show that high-fat (47 en%) diets suppress expression of CD3 and CD25 antigens. We also found that linseed-oil diets suppress expression of CD11a but enhance expression of CD25 antigens. Both CD3 and CD25 are critical for lymphocyte activation, and we conclude that immunosuppression associated with high-fat diets may be associated with suppression of these surface antigens.
Theoretical Model of Laser Grooving for Composite Materials

The influence of directionally-dependent thermal properties on laser machining effectiveness is analyzed theoretically and experimentally. A laser grooving model was developed which incorporated the effects of directionally-dependent thermal conductivity. Laser grooving experiments on graphite/vinylester composites showed differences in groove depth and profile depending on the laser beam direction relative to fiber orientation. The groove depth predictions from the composite grooving model showed an improved correlation with experimental data compared to predictions from the model with homogeneous material properties. The predictions of groove profiles and centerlines from the composites model are also presented for laser beam impingement parallel and perpendicular to fiber orientation.
Open adoption, human capital formation, and uncertainty

A model of child human capital formation is outlined, which is used to assess the consequences of uncertainty experienced by adoptive parents related to practices of openness in adoption. The model predicts that uncertainty in the adoption environment may lead to lower levels of human capital investments in adopted children. Empirical evidence indicates that uncertainty represented by fear of not bonding with the adopted child is the most important predictor of resistance to open adoption.
Behavioural responses to visual stimuli by the snails Tectarius muricatus, Turbo castanea, and Helix aspersa

Abstract The visual responses of three gastropods were studied for comparison with data previously obtained for the marsh periwinkle, Littorina irrorata. Turbo castanea , an archeogastropod inhabiting subtidal grass beds, had the lowest response thresholds for bar width (0.3–1.4 0 ) and shape reflectance (83%), and showed significant preferences in two binary-choice tests. Tectarius muricatus , a littorinid inhabiting hard substrate in the supratidal zone, had slightly higher response thresholds (1.4–6.5 o ; 75%) than T. castanea , and showed a significant preference in only one binary-choice test. Helix aspersa , a terrestrial pulmonate primarily active e at night, had much higher response thresholds (14.5–24.6°; 19%) than T. castanea and T. muricatus , and showed no significant preferences in binarychoice tests. Assuming that these response threshold estimates approximate actual sensory thresholds, then T. castanea can see slightly better than T. muricatus , and both species can see much better than H. aspersa . This conclusion coincides with expectations based on the light intensities and complexity of visual stimuli present in the habitats of these snails.
Kestrel: an XMPP-based framework for many task computing applications

This paper presents a new distributed computing framework for Many Task Computing (MTC) applications, based on the Extensible Messaging and Presence Protocol (XMPP). A lightweight, highly available system, named Kestrel, has been developed to explore XMPP-based techniques for improving MTC system tolerance to faults that result from scaling and intermittent computing agent presence. By leveraging technologies used in large instant messaging systems that scale to millions of clients, this MTC system is designed to scale to millions of agents at various levels of granularity: cores, machines, clusters, and even sensors, which makes it a good fit for MTC.Kestrel's architecture is inspired by the distributed design of pilot job frameworks on the grid as well as botnets, with the addition of a commodity instant messaging protocol for communications. Whereas botnet command-and-control systems have frequently used a combination of Internet Relay Chat (IRC), Distributed Hash Table (DHT), and other Peer-to-Peer (P2P) technologies, Kestrel utilizes XMPP for its presence notification capabilities, which allow the system to maintain continuous tracking of machine presence and state in real time. XMPP is also easily extensible with application-specific subprotocols, which can be utilized to transfer machine profile descriptions and job requirements. These sub-protocols can be used to implement distributed matching of jobs to systems, using a mechanism similar to ClassAds in the Condor High Throughput Computing (HTC) system.
A THEORETICAL DETERMINATION OF THE COLLECTION RATES OF AEROSOL PARTICLES BY FALLING ICE CRYSTAL PLATES AND COLUMNS

Abstract A theoretical model for the removal of aerosol particles by falling columnar ice crystals is compared to the model results for the removal of aerosol particles by falling planar ice crystals. These results incorporate gravitational, inertial, electrostatic, thermophoretic, diffusiophoretic, and Brownian diffusion mechanisms. Scavenging rates for columnar and planar ice crystals are computed for aerosol particles ranging from 0.001 to 10 μm in radius. The results show that planar ice crystals have greater collection efficiencies than the columnar ice crystals.
Microprocessor-Based Control for Independently-Phased RF Linac Cavities

A microprocessor based system has been built to control the RF amplifiers associated with independently phased linac cavities. The system has an 8080A at each amplifier station, together with associated ROM, RAM, I/O, etc. At a central NOVA 3 computer an additional 8080A system is incorporated in the interface to the NOVA I/O bus. The NOVA interface is connected by a bus of eighteen twisted pairs to each amplifier station, providing bilateral transmission between each station and the NOVA. The system architecture, bus protocol, and operating characteristics are described.
Fractals for functions with rational exponent

Abstract This paper investigates the fractals generated by the iteration of functions of the form f(z)=zα+c, where α is a rational non-integer number larger than 2, and z and c are complex numbers. We will examine both the dynamic and parameter spaces and discuss the consequences of the discontinuity of the function f(z). The images of these fractals allow for remarkable insight into the difficulty encountered in trying to extend results from polynomial cases to more generalized functions.
Hormonal Control of Growth in the Infant Rat

To obtain information on pituitary control of growth in infant rats, we employed a hypophysectomy technique which can be used on 4- to 6-day-old pups with an 80% success rate. A 30–50% reduction in body weight gain and a 30–40% decrease in tail growth were observed in the pups after hypophysectomy. The following hormone replacement injections were administered from days 7–15: ovine GH (oGH) or PRL (oPRL), at 1 or 4 μg/g BW, alone and in combination; T4 (40 ng/g for 4 days then 8 ng/g for 4 days) alone or in combination with the low dose of oPRL and/or oGH; and rat pituitary homogenate at 10 and 100 jug wet weight/g BW. Neither dose of oPRL increased weight gain or tail growth significantly. The high dose of oGH restored body weight gain and tail growth to 95% and 80%, respectively, of that in the sham controls. The low dose of GH increased both parameters to 75% of the sham values. Responses to injections of PRL and GH combined were intermediate between those of the hormones alone. T4 alone had no effect ...
Relation between extinction angle and molecular size

Abstract The relation between the observed extinction angle of flow birefringence measurements and the dimensions of the dissolved macromolecules is presented in graphical form for rapid computation. The calculations are based on a rigid ellipsoidal model for the solute particles.
The chicken clucks defiant: Revisiting male prostitution

David Henry Sterry’s memoir, Chicken, recounts a year in the early 1970s when the author worked as a teenage prostitute in southern California. In recreating Sterry’s encounters with his manager/pimp, other young sex workers, and a primarily female clientele, the book offers a perspective that is unique among the larger genre created by the “sex worker literati.” By broadening our understanding of male prostitution in particular, and sex workers and commercial sex consumers more generally, Sterry’s memoir is important to social scientists and sex researchers as well as to devotees of pop culture.
Value of Carbon Dioxide in Counteracting Oxygen Lack

THE recent paper by Childs, Hamlin and Henderson1 has again centred attention upon the old observations of Mosso2, who showed that in low-pressure chamber experiments the presence of small concentrations of carbon dioxide (2–5 per cent) increased the resistance of his experimental subjects to lowering of the barometric pressure. Similar observations were reported by Margaria3, and Talenti4, who found that the resistance against the lowering of the barometric pressure was increased in the presence of carbon dioxide, provided that the gas mixture in the chamber was pure oxygen. The attempts, however, to prove that carbon dioxide had a similar beneficial effect on oxygen lack when air was diluted by nitrogen gave paradoxically negative results (Margaria5). In view of the contradictory character of these earlier studies, and since it has been shown that oxygen lack produces quantitatively measurable effects on the human central nervous system (Gellhorn and Spiesman6, and Gellhorn and Kraines7), it seemed to be of considerable interest to investigate whether the effects of oxygen lack on the human central nervous system could be alleviated or altered by the presence of carbon dioxide and, furthermore, to ascertain what the mechanism of this reaction might be.
Improving Transmission Privacy Using Optical Layer XOR

We built novel "dual code" OCDMA transmitter and receiver with optical layer XOR, thus achieving data privacy approaching one-time pad security. Enhanced secure communication among users was demonstrated at OC-24 with raw BER < 10-12.
Metabolizable Energy of Feed Ingredients for the Growing Chick

Abstract Hill and Anderson (1958) and Potter et al. (1960) have shown that metabolizable energy of a diet is more precisely measured than is productive energy. In an effort to obtain reliable estimates of useful energy content of poultry feeds, a series of studies have been directed toward determining the metabolizable energy of feed ingredients. Sixty-one samples of feed ingredients, representing 27 poultry feedstuffs, have been evaluated. Using a basal diet patterned after that of Hill and Anderson (1958), experimental diets were formulated by adding, on a dry matter basis, the test ingredient at the expense of a portion of the total diet, or at the expense of cerelose in the basal diet. The rate of substitution was usually between 20 and 66⅔ percent of the diet. Each diet was fed to 2 to 6 groups of 9 chicks each for an experimental period from 2 to 4 weeks of age… .
A systematic procedure for the selection of bulk material handling equipment

Abstract Many companies use materials shipped in bulk and must solve material handling problems associated with these materials. This paper concentrates on the selection of relevant factors that need to be considered in the design of a bulk material handling system and on the selection of equipment once these factors have been considered. A model is presented which takes into account economics, characteristics of the equipment, environmental characteristics, and compatibilities between equipment types.
Venus Lower Atmospheric Composition: Analysis by Gas Chromatography

The first gas chromatographic analysis of the lower atmosphere of Venus is reported. Three atmospheric samples were analyzed. The third of these samples showed carbon dioxide (96.4 percent), molecular nitrogen (3.41 percent), water vapor (0.135 percent), molecular oxygen [69.3 parts per million (ppm)], argon (18.6 ppm), neon (4.31 ppm), and sulfuir dioxide (186 ppm). The amounts of water vapor and sulfur dioxide detected are roughly compatible with the requirements of greenhouse models of the high surface temperature of Venus. The large positive gradient of sulfur dioxide, molecular oxygen, and water vapor from the clould tops to their bottoms, as implied by Earth-based observations and these resuilts, gives added support for the presence of major quantities of aqueous sulfuric acid in the clouds. A comparison of the inventory of inert gases found in the atmospheres of Venus, Earth, and Mars suggests that these components are due to outgassing from the planetary interiors.
Resistivity Response of a Homogeneous Earth with a Contained Vertical Conductor

Using a simple model, we illustrate the influence of a cylindrical conductor on the apparent resistivity for a two-electrode array on a otherwise homogeneous earth. In the formulation, the cylindrical conductor is assumed to be of infinite length. However, by exploiting a simple image plane concept, the solution is applicable to the case where the electrodes are on the surface of a homogeneous half-space model of the earth and the cylindrical conductor extends from the surface vertically downward to infinity. Thus the configuration could correspond, in an ideal sense, to a vertical metal well casing or a similar conductive structure that outcrops to the surface. The calculations indicate the apparent resistivity can be seriously modified by the presence of the cylinder even when the electrodes are located at a distance more than tenfold the cylinder radius. Also, the formulation allows for the presence of an interface impedance at the metal surface of the cylinder. This could be used as a model to examine the induced polarization response.
Optimal control policy for substrate inhibited kinetics with enzyme deactivation in an isothermal CSTR

A slow enzyme deactivation process taking place in parallel with the main enzymatic reaction in a continuous stirred-tank reactor can cause a departure from the optimal operating conditions, or, even a reactor failure. One way of minimizing productivity losses and maintaining optimal reactor conditions is by properly manipulating the flow rate of the reactor. The optimal flow-control policy for typical enzyme kinetics with parallel enzyme deactivation is derived. Both the complete and an approximate analytical solution are presented. The approximate solution, which is actually a quasisteady-state solution, is a very good approximation when the deactivation process is slow compared to the main enzymatic reaction and can be easily implemented as a feedback control based on the current state of the reactor. If the deactivation kinetics is the same as that of the main reaction and the cost of the reactant is negligible compared to that of the product, the quasisteady-state solution is indeed the exact solution.
A comparative analysis of DSS user-friendliness and effectiveness

Both researchers and practitioners consider usability of decision support systems (DSS) to be the most important feature that an effective DSS should possess. The buzzword 'user-friendly' is so overused by vendors and system designers that it has almost lost its meaning. In this era when DSSs are deployed by organizations towards strategic ends, it makes sense to determine at what price userfriendliness should be obtained. The main purpose of this study was to determine empirically whether user-friendliness is indeed associated with DSS effectiveness. Results from a mail survey of 201 DSS users indicated that user-friendliness has a positive association with decision quality and overall satisfaction, but has no significant relationship with time savings and cost effectiveness. The results also indicate that user-friendliness may hinder productivity. This finding has some implications for DSS designers/developers and researchers. Overall, the findings suggest that while user-friendliness is highly desirable of a DSS, it does not contribute to DSS effectiveness in terms of some of the major measures - time savings, productivity, and overall cost effectiveness.
The update on the rationale, use and selection of β-blockers in heart failure

Purpose of reviewThe purpose of this review was to describe important developments in the selection of β-blockers in heart failure.Recent findingsThe superiority of carvedilol over metoprolol tartrate in one clinical trial is demonstrated, and multiple studies investigated the potential mechanisms o
Optimum Filters for Estimating Evoked Potential Waveforms

The design of time-invariant and time-varying minimum mean square error filters for processing event related brain potentials is considered. A model for taking into account the randomness associated with the signal as well as that of the noise is described. Results using simulated data show the perfonnance of the time-varying filter to be greatly superior to that of the time-invariant filter. Results of processing measured visual evoked potentials are presented.
The many meanings of sleep

Abstract Reductions in sleep are concomitant with night shift work. Data are presented showing that these robust differences in sleep are even present in experienced permanent night shift workers who most prefer to work nights. A model is presented which relates these reductions to chronic sleep deprivation. This, in turn, may be associated with performance decrements, and lead to accidents and illness. Better work schedule selection, worker training programs, and preventive medical action are unproven but promising approaches to overturning this model.
Visibility thresholds for compression-induced image blocking: measurements and models

The present investigation compares performance of two objective video quality metrics in predicting the visual threshold for the detection of blocking impairments associated with MPEG-2 compression. The visibility thresholds for both saturated color and gray-scale targets are measured. The test material consists of image sequences in which either saturated color or gray-scale targets exhibiting blocking are varied in luminance contrast from -44 dB to -5 dB against a constant gray background. Stimulus presentation is by the 'method of limits' under International Telecommunications Union Rec. 500 conditions. Results find the detection of blocking impairments at Michelson contrast levels between -28 dB and -33 dB. This result is consistent with values reported by other investigators for luminance contrast detection thresholds. A small, but statistically significant difference is found between the detection threshold of saturated color patterns versus luma-only images. The results suggest, however, that blocking impairment detections controlled mainly by display luminance. Two objective metrics are applied to gray-scale image sequences, yielding measures of perceptible image blocking for each frame. A relatively simple blocking detector and a more elaborate discrete cosine transform error metric correlate well over the contrast range examined. Also, the two measures correlate highly with measured image contrast. Both objective metrics agree closely with visual threshold measurements, yielding threshold predictions of approximately -29 dB.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nondeterministic theories of climatic change

A basic assumption in some climatic theories is that, given the physical properties of the atmosphere and the underlying ocean and land, specified environmental parameters (amount of solar heating, etc.) would determine a unique climate and that climatic changes therefore result from changes in the environment. The possibility that no such unique climate exists and that nondeterministic factors are wholly or partly responsible for long-period fluctuations of the atmosphere-ocean-earth system, is considered. A simple difference equation is used to illustrate the phenomena of transitivity, intransitivity, and almost-intransitivity. Numerical models of moderate size suggest that almost-intransitivity might lead to persistence of atmospheric anomalies for a whole season. The effect of this persistence could be to allow substantial anomalies to build up in the underlying ocean or land, perhaps as abnormal temperatures or excessive snow or ice. These anomalies could subsequently influence the atmosphere, leading to long-period fluctuations. The implications of this possibility for the numerical modeling of climate, and for the interpretation of the output of numerical models, are discussed.
Kinetics of interaction of some α- and β-D-monosaccharides with concanavalin A

Abstract The rates of formation and dissociation of concanavalin A with some 4-methylumbelliferyl and p-nitrophenyl derivatives of α- and β- D -mannopyranosides and glucopyranosides were measured by fluorescence and spectral stopped-flow methods. All process examined were uniphasic. The second-order formation rate constants varied only from 6.8 · 104 to 12.8 · 104 M−. s−1, whereas the first-order dissociation rate constants ranged from 4.1. to 220 s−1, all at ph 5.0, I = 0.3 M, and 25°C. Dissociation rates thus controlled the value of binding constant. The effect of temperature on these reactions was examined, from which enthalpies and entropies of activation and of reaction could be calculated. The effects of pH at 25°C on the reaction rates of 4-methylumbelliferyl α- D -mannopyranoside and 4-methylumbelliferyl α- D -glucopyranoside with concanavalin A were examined. The value of the binding constant Kap (derived from the kinetics) at any pH could be related to the intrinsic binding constant K by the expression Kap = KaK(Ka + [H+])−1. The values of Ka, the ionization constant of the protein segment responsive to sugar binding, were 3 · 10−4 M and 1 · 10−4 M for 4-methylumbelliferyl α- D -mannopyranoside and 4-methylumbelliferyl α- D -glucopyranoside, respectively. The binding constant of p-nitrophenyl α- D -mannopyranoside is surprisingly much less sensitive to a pH change from 5.0 to 2.7. Ionic strength had little effect on the binding characteristics of 4-methylumbelliferyl α- D -mannopyranoside to concanavalin A at pH 5.2 and 25°C.
Stability in parliamentary regimes: The Italian case

In this article, we distinguish legislative stability from government stability and argue that the character of the relationship that exists between them is a complex one in which various combinations are possible. We focus on Italy because of the manner in which it has combined legislative stability with government instability. Our findings indicate that the relationship between legislative and government stability in Italy is best seen as curvilinear, that the analysis of government stability must take the number of governments as well as the duration of governments into account, and that the attributes of the party system that stabilize the legislature destabilize governments. Given these findings, we discuss their implications for explaining stability in parliamentary regimes in terms of events, "strong parties," and strategic calculation. We conclude that legislative stability should not be treated simply as a secondary or derivative effect of government stability and that Italy can serve as a benchmark for further study of the nature and determinants of the relationship between the two in other parliamentary systems.
Stress-intensity factors for surface cracks in functionally graded materials under mode-I thermomechanical loading

Abstract This paper describes the development and application of a general domain integral method to obtain J -values along crack fronts in three-dimensional configurations of isotropic, functionally graded materials (FGMs). The present work considers mode-I, linear-elastic response of cracked specimens subjected to thermomechanical loading, although the domain integral formulation accommodates elastic–plastic behavior in FGMs. Finite element solutions and domain integral J -values for a two-dimensional edge crack show good agreement with available analytical solutions for both tension loading and temperature gradients. A displacement correlation technique provides pointwise stress-intensity values along semi-elliptical surface cracks in FGMs for comparison with values derived from the proposed domain integral. Numerical implementation and mesh refinement issues to maintain path independent J -values are explored. The paper concludes with a parametric study that provides a set of stress-intensity factors for semi-elliptical surface cracks covering a practical range of crack sizes, aspect ratios and material property gradations under tension, bending and spatially-varying temperature loads.
Self-organization of Hebbian Synapses in Hippocampal Neurons

We are exploring the significance of biological complexity for neuronal computation. Here we demonstrate that Hebbian synapses in realistically-modeled hippocampal pyramidal cells may give rise to two novel forms of self-organization in response to structured synaptic input. First, on the basis of the electrotonic relationships between synaptic contacts, a cell may become tuned to a small subset of its input space. Second, the same mechanisms may produce clusters of potentiated synapses across the space of the dendrites. The latter type of self-organization may be functionally significant in the presence of nonlinear dendritic conductances.
Exotic plant species in a C4-dominated grassland: invasibility, disturbance, and community structure

We used data from a 15-year experiment in a C4-dominated grassland to address the effects of community structure (i.e., plant species richness, dominance) and disturbance on invasibility, as measured by abundance and richness of exotic species. Our specific objectives were to assess the temporal and spatial patterns of exotic plant species in a native grassland in Kansas (USA) and to determine the factors that control exotic species abundance and richness (i.e., invasibility). Exotic species (90% C3 plants) comprised approximately 10% of the flora, and their turnover was relatively high (30%) over the 15-year period. We found that disturbances significantly affected the abundance and richness of exotic species. In particular, long-term annually burned watersheds had lower cover of exotic species than unburned watersheds, and fire reduced exotic species richness by 80–90%. Exotic and native species richness were positively correlated across sites subjected to different fire (r = 0.72) and grazing (r = 0.67) treatments, and the number of exotic species was lowest on sites with the highest productivity of C4 grasses (i.e., high dominance). These results provide strong evidence for the role of community structure, as affected by disturbance, in determining invasibility of this grassland. Moreover, a significant positive relationship between exotic and native species richness was observed within a disturbance regime (annually burned sites, r = 0.51; unburned sites, r = 0.59). Thus, invasibility of this C4-dominated grassland can also be directly related to community structure independent of disturbance.
JOYCE: a next generation personal computer

This paper describes the hardware/software design decisions, cost, and development status the JOYCE personal computer. The features of the system are examined in light of scheduled applications such as CAI (a stand alone PLATO system), database management, electronic mail, and other network communication facilities. Plans for continued system development are outlined.Our experiences relating to the acquisition of the components necessary for the realization of JOYCE, including delivery delays, vendor promises, and the gap between vendor product actual operation and documented operational descriptions will be detailed.
Improving Endurance and Range of a UGV with Gimballed Landing Platform for Launching Small Unmanned Helicopters

Design specifications for a high-endurance and range unmanned ground vehicle (UGV) with a gimballed landing platform on top of it for takeoff/landing, transporting to the target area and recharging of small/miniature unmanned helicopters are presented and justified. Specification constraints include UGV strict payload limitations, limited free space affecting power supply availability that impacts on-board available energy, limited endurance and operational range, as well as limitations and restrictions related to electric and non-electric small unmanned vertical takeoff and landing (VTOL) vehicles, similar to those of UGV with the most important being limited flying time. Focusing on the All Terrain Robot Vehicle (ATRV-Jr) UGV and a helicopter of the size of the Maxi Joker 2 as a testbed, a detailed analysis of component power consumption reveals reasons for reduced runtime and operational range. After a comparative study of state of the art power supply and battery technologies, a hybrid battery configuration is proposed that improves more than 500% the manufacturer-specified ATRV-Jr endurance (or 1,000% the currently used custom-made ATRV-Jr endurance) by considering: (1) optimum design with weight, volume, runtime and rechargeability being major restrictions and concerns, and (2) use of lower power sensors and processors without affecting UGV functionality and operability. A sun-tracking solar array that collects and stores energy is integrated with the UGV gimballed landing platform. Simulations demonstrate the validity of the design. Although the testbed is specific, the design itself is generic enough and suitable for other UGV/VTOL vehicles.
An Institution‐Specific Heparin Titration Nomogram: Development, Validation, and Assessment of Compliance

Study Objective. To develop, validate, and assess compliance with a heparin titration nomogram. Design. Prospective, open-label trial. Setting. University teaching hospital. Subjects. Patients admitted with heart failure who required therapy with intravenous unfractionated heparin. Intervention. An in vitro concentration-response was determined by measuring activated partial thromboplastin times (aPTTs) on normal pooled plasma containing known concentrations of heparin. The therapeutic aPTT range was determined from the concentration-response by using the therapeutic heparin concentration range of 0.2-0.4 U/ml (protamine neutralization). Patients were consecutively enrolled, and therapy was managed by using the heparin titration nomogram. Paired aPTT-heparin concentrations were obtained, and nomogram validation was performed by comparing the in vitro and the ex vivo concentration-responses with use of linear regression. Nomogram compliance also was assessed. Measurements and Main Results. The therapeutic aPTT ranges based on in vitro and ex vivo data were determined to be 45-72 seconds and 47-61 seconds, respectively. The ranges were significantly different (p<0.001). Overall compliance with the nomogram was 88%. Conclusion. These results confirm that, even in a relatively homogeneous disease-state patient population, in vitro data do not accurately predict ex vivo data. If in vitro data are used to develop an institution-specific nomogram, a validation procedure should be used to ensure accuracy. Although 100% compliance to a nomogram may not be attainable, it should be expected. Therefore, a compliance rate of 88% is concerning and suggests a need for increased nursing and physician education.
DAI betwixt and between: from 'intelligent agents' to open systems science

The authors discuss the development of open systems science (OSS) beginning with its roots in the fundamentals of concurrency. The nature of actors., which are the primitives of concurrency, is considered. The aim of OSS is to provide a foundation for effective technological solutions to the complex problems of large-scale open systems by providing a scientific discipline that focuses on issues of robustness, manageability, and scalability. In the large-scale open systems of the future, the focus with shift from centralized systems toward decentralized ones, with an emphasis on conflict processing. The evolution of this paradigm presents some challenges and some fruitful new ideas for distributed artificial intelligence that are discussed. >
A Longitudinal Study of Risk-Glorifying Video Games and Reckless Driving

A multiwave longitudinal study investigated the association of playing mature-rated and risk-glorifying video games and risky driving among adolescents. The study involved a large random digit dial telephone survey. Data were analyzed using structural equation modeling and included auto-regressive lags for the major outcome variables. Consistent with predictions, playing the targeted games was associated with increased reports of a variety of risky driving habits (e.g., speeding, tailgating, weaving in traffic), being pulled over by the police, automobile accidents, and willingness to drink and drive. These effects were observed after controlling for a variety of demographic and parenting variables. Finally, the effects of these games were shown to be mediated by increases in sensation seeking and rebelliousness. The results support a view of video games as affecting real-world behavior by altering a sense of self.
Tandem Affinity Purification (TAP) Tags

Cells respond to myriad intra- and extracellular cues often by modulating the formation and function of heteromeric protein complexes (PCs). Thus, developing a comprehensive picture of cellular behavior and understanding biological responses requires characterization of PCs in their proper cellular context. Tandem affinity purification (TAP) is a two-step affinity purification method that aids in rapid isolation of PCs under native conditions. Since its original description in yeast, numerous variations of the affinity tag combinations have been developed to address some of the inadequacies of the original method and to accommodate the expanding scope of applications. The TAP, in combination with mass spectrometry, has paved the way for large-scale characterization of PCs and the dynamic protein interaction networks (PINs) in diverse organisms over the past decade. Key Concepts: Characterizing the architecture of protein complexes and protein interaction networks is essential to decipher the cellular responses to environmental cues. Sequential affinity purification steps employed in tandem-affinity purification aid in specific and rapid purification of protein complexes. Standardized TAP protocols could benefit both intra- and inter-laboratory reproducibility of large-scale protein complex characterization efforts. Keywords: tandem-affinity purification; protein–protein interaction; protein interaction network; protein purification; mass spectrometry