cssi/SciSciGPT-SciSciNet huggingface dataset:
Portals and the human factor: Bringing virtual services to the life of the mind or the scholarly stargate

L'A. examine le concept de portail d'information savant, veritable porte des etoiles, en terme de services concus pour aider l'utilisateur non seulement a s'orienter mais aussi a localiser et appliquer son contenu dans le cadre de sa recherche et de son apprentissage. Elle examine differents types de portails, uniques ou multiples, y compris les services permettant l'integration au sein ou entre portails. L'exemple des portails institutionnels et leur lien avec les initiatives de bibliotheques electroniques fournit l'occasion de traiter la question des interactions avec l'utilisateur. Les portails de l'avenir devraient voir augmenter leurs fonctionnalites et leur portee.
Melatonin Synthesis: Multiplicity of Regulation

N-acetyl-5-methoxytryptamine, commonly known as melatonin, was initially thought to be synthesized exclusively in the pineal gland (Ebadi, 1984). However, subsequent examination of a variety of tissues indicates melatonin is very likely produced in the retina (Gern et al., 1978), the Harderian glands (Bubenik et al., 1976), the extra-orbital lacrimal glands (Mhatre et al., 1988), portions of the gastrointestinal tract (Vakkuri et al., 1985), and certain blood cells (Finocchiaro et al., 1988). The regulation of melatonin synthesis likely differs at these sites; the current brief survey will consider melatonin production exclusively in the mammalian pineal gland. Much of what is known concerning pineal melatonin production has been derived from studies in two species, the rat and the Syrian hamster (Mesocricetus auratus). Thus, the current review will summarize the findings primarily from these species and the assumption will be made that the regulation of the conversion of serotonin to melatonin is similar in the pineal gland of other mammals.
Regulation of the murine αA-crystallin promoter in transgenic mice

To identify sequences necessary for lens-specific gene expression, lines of transgenic mice were generated which contain murine alpha A-crystallin promoter sequences [-111 to +46 (alpha 111), -88 to +46 (alpha 88), and -34 to +46 (alpha 34)] fused to the bacterial chloramphenicol acetyltransferase (CAT) gene and CAT expression was analyzed. Mice carrying the alpha 111-CAT or the alpha 88-CAT fusion transgene expressed CAT exclusively in lens, except for one line containing alpha 111-CAT, which expressed low levels of CAT in several nonlenticular tissues. Transcription from these promoters in lens initiated at the same site as the endogenous alpha A-crystallin promoter. In one line of mice alpha 88-CAT transgene became active in the lens during embryonic development at approximately the same time that the alpha A-crystallin gene normally begins to be expressed. In contrast, the alpha 34-CAT fusion transgene, containing the TATA box but no sequences further upstream, was inactive in transgenic mice. Our data suggest that 134 bp of sequence (-88 to +46) in the murine alpha A-crystallin gene is sufficient to provide lens specificity, although we cannot rule out the possibility that other sequences also contribute to promoter function.
Setting the MoUbius Strip Straight: John Barth's Once Upon a Time: A Floating Opera

Abstract After all these years of dismay with what he considered a violation of his privacy by biographical critics, John Barth has published his own semifictionalized autobiography, or at least as much as his wife, Shelly, would permit—if we are to believe Barth's latest narrator. The key to the admitted portion—from infancy to the beginning of the 1970s—confirms some scholarly speculation, while exciting more, and includes much that Barth has already detailed in articles, interviews, and dialogues between his characters. Why an autobiographical book now? And why the structural conceit of music, more pointedly an opera? How much of it are we to believe, how much to accept as another fiction? Why conceive of it as a fiction or a fiction within a fiction, and why admit admittedly fictive characters?
Effects of a powered ankle-foot prosthesis on kinetic loading of the contralateral limb: A case series

Lower-extremity amputees encounter a series of stress-related challenges. Among them is an increased risk of chronic joint disorders. For unilateral, transtibial amputees, we hypothesize that increasing the power output of the trailing, ankle-foot prosthesis during powered plantar flexion could mitigate kinetic loading applied to the leading, contralateral leg during walking. Here, we present a case series that analyzes kinetic factors of unilateral, transtibial amputee gait and forms a comparison between two types of ankle prostheses with varying power outputs. The factors examined here are impact resultant force, peak foot pressure at heel-strike, step-to-step transition work, and knee external adduction moment. The two prostheses are the amputee participant's daily-use passive ankle-foot prosthesis and the BiOM powered ankle-foot prosthesis capable of biologically accurate powered plantar flexion during late stance. In a preliminary study on two transtibial amputees walking over level terrain at a controlled speed (1.25 m/s), we observed average reductions of 8% in peak impact resultant force, 18% in impact resultant force loading rate, 8% in peak heel-strike foot pressure, and 15% in the 1st peak knee external adduction moment when the powered ankle-foot prosthesis was compared to the conventional passive prosthesis. Overall, our preliminary results suggest that more biomimetic prosthetic ankle-foot push-off during late stance may limit leading-leg musculoskeletal stress in walking.
Cumulative Risk Assessment for Combined Health Effects From Chemical and Nonchemical Stressors

Cumulative risk assessment is a science policy tool for organizing and analyzing information to examine, characterize, and possibly quantify combined threats from multiple environmental stressors. We briefly survey the state of the art regarding cumulative risk assessment, emphasizing challenges and complexities of moving beyond the current focus on chemical mixtures to incorporate nonchemical stressors, such as poverty and discrimination, into the assessment paradigm. Theoretical frameworks for integrating nonchemical stressors into cumulative risk assessments are discussed, the impact of geospatial issues on interpreting results of statistical analyses is described, and four assessment methods are used to illustrate the diversity of current approaches. Prospects for future progress depend on adequate research support as well as development and verification of appropriate analytic frameworks.
Selective formation of isobutane and isobutene from synthesis gas over zirconia catalysts prepared by a modified sol-gel method

Zirconium oxide was synthesized by a modified sol-gel method, and was evaluated for the selective formation of isobutane and isobutene from synthesis gas. Due to increased basicity, zirconia from sol-gel preparation showed higher selectivities to iso-C[sub 4]'s while maintaining the same level of activity as zirconia prepared by calcination of zirconyl salts. The catalysts was further modified with Group I and II elements, and the activity tests showed increased iso-C[sub 4] and decreased methane production for the catalysts doped with potassium, magnesium, calcium, or barium. 29 refs., 10 figs., 1 tab.
A modified MM2 force field for high-valent di-μ-oxo manganese dimers

Abstract We have modified the MM2 force field to energy minimize the structure of high-valent di-μ-oxo manganese dimers with trapped valences. This modified force field is applicable to any oxygen/nitrogen ligation around the manganese centers. Two structurally distinct oxidation states of manganese (manganese(III) and manganese(IV)) can be minimized simultaneously. This is the first such example of a force field which can accommodate a mixed-valence dinuclear metal complex. Systematic modifications to the original MM2 force field and subsequent minimizations of various oxomanganese dimers have been presented.
Preparation of GDP-d-mannose specifically labeled with tritium in the d-mannosyl moiety

Abstract The multistep enzymatic conversion of d -[5-3H]glucose to d -[5-3H]mannose is described. The d -5-3H]mannose was in turn converted to guanosine 5′-(α- d -[5-3H]mannopyranosyl pyrophosphate) using an extract from Arthrobacter viscosus, NRRL 1973. The overall radiochemical yield was 25%.
Calculations of Dihydrogen Binding to Doped Carbon Nanostructures

We used second-order Moller-Plesset perturbation theory to calculate the binding energies of hydrogen molecules to various carbon nanostructures, in an effort to find improved hydrogen storage materials. For the central concave site of corannulene, a new binding geometry was found, with the H2 molecule in a parallel configuration, and an improved corrected binding energy of 9.8 kJ/mol was discovered. We studied the binding of hydrogen to B and Be doped small carbon nanostructures. For B doped corannulene, Kubas binding was observed in a metastable state. For C11H8Be, a binding energy of 17.5 kJ/mol and, for C16Be2H8, a binding energy of 12.3 kJ/mol due to Kubas-type non-dissociative adsorption were found. Benzene-B,N-2COOH and pyrazine dicarboxylate were proposed as higher binding energy building blocks for the metal−organic framework materials. For both benzene-B,N-2COOH and pyrazine dicarboxylate, we found low physisorption binding energies.
Effect of acute gamma irradiation on the incidence of tumor-like structures and adventitious roots in lettuce plants

Abstract Acute γ-irradiation caused tumor-like structures and an increase in the incidence of adventitious roots on lettuce ( Lactuca sativa H V great lakes). While untreated plants of this variety only occasionally develop adventitious roots on stems, the number of plants with adventitious roots increased after exposures of 4 and 6 kR and reached 100 per cent after 7 kR. Similarly, the number of adventitious roots per plant increased with exposure dose. Some roots formed directly on the stems, but they occurred more frequently on small (1–5 mm diam) bulbous, nonchlorophyllous tumors which developed on leaves as well as on stems. Larger (up to 30 mm diam) chlorophyllous tumors formed after exposures of 6 and 7 kR. They were associated with basal leaves, being most common at the bases of the blades. In some cases they occurred along the leaf margins. Of the plants exposed to 6 kR, 80 per cent became tumorous whereas only 50 per cent of those exposed to 7 kR formed tumors.
Analysis of routing protocols and interference-limited communication in large wireless networks via continuum modeling

The evaluation and assessment of the design of large wireless networks is an important problem in numerous applications. Direct simulation is a traditional approach for studying such networks but is severely limited in its utility as the size of the network increases. This necessitates other means for studying large networks, one of which is the modeling of large networks with continuum models. In this paper, we introduce nonlinear partial differential equations whose solutions approximate the expected behavior of large networks governed by probabilistic communication rules. The relative speed at which solutions can be obtained from the continuum models allows for the investigation of routing protocols and communication limitations due to interference—a feat that is not feasible via simulation methods. Specifically, we investigate the effects of a directed diffusion routing protocol and explore communication limitations in an interference-sensitive network. Network design studies using the approximating continuum models are then presented.
Boards of Directors and the Adoption of a CEO Performance Evaluation Process: Agency — and Institutional — Theory Perspectives

Using both agency and institutional theories, we examined factors associated with the board’s adoption of a formal process for evaluating the performance of the corporation’s chief executive officer (CEO). Our sample was drawn from the hospital industry. Results show that an independent board chairperson, the level of market competition and the degree of managed care penetration were significant predictors of whether or not the board had adopted a formal CEO evaluation process. These findings imply that initiatives to improve governance effectiveness based on agency theory should take into account the institutional environment of corporate boards.
THE BEST OF THE BEST: LESSONS FROM THE TOP PERFORMING AMERICAN CORPORATIONS, 1954-2005

Purpose – To derive and apply a new composite performance metric to top performing US companies in order to identify consistently excellent performers and explain their success over the last half‐century. The ten firms topping the list for this new composite performance metric represent the “best of the best” of American corporations during the fifty‐one years of Fortune magazine listings.Design/methodology/approach – Data for this analysis were gleaned from the annual lists of the top 500 companies reported by Fortune from 1954 to 2005. Using Fortune's annual rankings of companies according to the four performance criteria of return on investment/equity, net profits, total assets, and revenues dimensions, the authors firstly computed, for each of these four performance dimensions, an average ranking based on a company's particular rank each year and its total number of appearances during the 51‐year period; and then, secondly, by assigning each of the four performance criteria a weight reflecting its imp...
Selection of relaying quantities for differential feeder protection

Differential feeder protection, in general, uses a single relaying quantity derived from all phases of the system being protected. The paper contains a comprehensive analysis of the nature of this relaying quantity for the whole range of single shunt faults and all likely combinations of phase-sequence quantities extracted from the faulted system. The analysis includes the well-established case of the summation transformer, this device having an output which contains positive, negative and zero phase-sequence components of current. The analysis is presented in the form of curves giving the relaying quantity in terms of the important components of the various phase-sequence impedances of the power system. From these curves it is possible compare the different ways of deriving the single-phase relaying quantity and thence to specify the general rules for selection phase-sequence networks. In order to provide a comprehensive method for determining a differential relaying quantity in magnitude and phase, a general chart has been developed; from this, the magnitude and phase of the relaying quantity, derived from any specified phase-sequence network, may be obtained graphically in terms of the positive and zero phase-sequence reactances and the zero-sequence resistance of the power system. Finally, the effect of load current on the magnitude of a derived relaying quantity has been considered. The corresponding effect on phase has not been treated since it has already appeared elsewhere, although the results have been included for purposes of comparison and completeness.
Experimental and computational results for 5 degree blunt cones with shock generators at high velocity

Experiments and computations have been performed under laminar conditions in air on 5-deg blunt cones at velocities of 5 km/s and 6 km/s and at Reynolds numbers of 100,000 and 1 million. The computations were performed using ideal-, equilibrium- and nonequilibrium-chemistry models for air. At the conditions of the tests, the aerodynamic coefficients are sensitive to the real-gas effects present, and both experimental and computational aerodynamic coefficients show real-gas and nonlinear effects. The nonequilibrium computations show that a large amount of oxygen is dissociated in the blunt nose region of the flow and much of the oxygen remains dissociated over the entire length of the body, providing an insight into the source of the observed effects in the aerodynamic coefficients. The experimental and computational shock-shapes are in good agreement.
Investigation of the nucleation and growth of thin-film phosphors

The deposition of CaGa{sub 2}S{sub 4}:Ce has been accomplished using a commercial liquid delivery system on two substrate surfaces: ZnS and SrS. However, the film deposited on ZnS was not of satisfactory quality because of the formation of an amorphous layer and a high amount of residual porosity within the deposition. The use of a SrS layer on top of the ZnS improved the nucleation by reducing the interfacial energy between the substrate and deposition. It greatly reduced the porosity in the coating and reduced the formation of the amorphous layer. The crystallinity of the CaGa{sub 2}S{sub 4} 400 peak was also increased by a factor of ten when a layer of SrS was used. Further, the FWHM of the 400 peaks from the two depositions was not significantly different, indicating that the crystallite size and strain was approximately the same. The B{sub 40} was increased by a factor of two, from 1.84 cd/m{sup 2} for ZnS to 3.67 cd/m{sup 2} for SrS. This increase is an improvement in the performance of the films and is attributable to the increase in the crystallinity.
Attribution and Impacts of Upper-Ocean Biases in CCSM3

The largest and potentially most important ocean near-surface biases are examined in the Community Climate System Model coupled simulation of present-day conditions. They are attributed to problems in the component models of the ocean or atmosphere, or both. Tropical biases in sea surface salinity (SSS) are associated with precipitation errors, with the most striking being a band of excess rainfall across the South Pacific at about 8°S. Cooler-than-observed equatorial Pacific sea surface temperature (SST) is necessary to control a potentially catastrophic positive feedback, involving precipitation along the equator. The strength of the wind-driven gyres and interbasin exchange is in reasonable agreement with observations, despite the generally too strong near-surface winds. However, the winds drive far too much transport through Drake Passage [190 Sv (1 Sv 10 6 m 3 s 1 )], but with little effect on SST and SSS. Problems with the width, separation, and location of western boundary currents and their extensions create large correlated SST and SSS biases in midlatitudes. Ocean model deficiencies are suspected because similar signals are seen in uncoupled ocean solutions, but there is no evidence of serious remote impacts. The seasonal cycles of SST and winds in the equatorial Pacific are not well represented, and numerical experiments suggest that these problems are initiated by the coupling of either or both wind components. The largest mean SST biases develop along the eastern boundaries of subtropical gyres, and the overall coupled model response is found to be linear. In the South Atlantic, surface currents advect these biases across much of the tropical basin. Significant precipitation responses are found both in the northwest Indian Ocean, and locally where the net result is the loss of an identifiable Atlantic intertropical convergence zone, which can be regained by controlling the coastal temperatures and salinities. Biases off South America and Baja California are shown to significantly degrade precipitation across the Pacific, subsurface ocean properties on both sides of the equator, and the seasonal cycle of equatorial SST in the eastern Pacific. These signals extend beyond the reach of surface currents, so connections via the atmosphere and subsurface ocean are implicated. Other experimental results indicate that the local atmospheric forcing is only part of the problem along eastern boundaries, with the representation of ocean upwelling another likely contributor.
Perinatal induction of immunotolerance to cardiac and pulmonary allografts.

Abstract Objectives: Tolerance appears to be more easily induced in the fetus before full immunocompetence is established, but elucidation of this process is needed. A model of perinatal tolerance induction to neonatal skin allografts followed by cardiac and pulmonary allografts is described. Methods: Sixty Lewis (RT1 1 ) rat fetuses were inoculated intraperitoneally at 18 days' gestation with 1 × 10 7 ACI (RT1 a ) rat fetal liver cells (group I); 20 Lewis fetuses were inoculated with 2 × 10 7 ACI fetal liver cells (group II). Control groups consisted of Lewis fetuses inoculated with saline solution ( n = 25, group III) and fetuses that were not inoculated ( n = 25, group IV). Twenty-five of the 50 surviving group I rats received ACI skin ( Results: Abortion rates in groups I, II, III, and IV were 17% (10/60), 65% (13/20), 8% (2/25), and 4% (1/25), respectively. Specific tolerance to skin, cardiac, and lung allografts was observed in seven of 25 group IA recipients (28%) and seven of seven group II recipients (100%) compared with no tolerance in any group IB, III, or IV recipients ( p = 0.03, χ 2 test). A 100-fold reduction of precursor cytotoxic T lymphocytes and significant splenocyte and bone marrow chimerism in tolerant versus nontolerant rats were noted ( p = 0.0001, Student's t test). Conclusions: Using donor-strain fetal liver cells and neonatal skin grafts, we achieved higher frequencies of tolerance to solid organ grafts in adulthood with lower cell inocula and abortion rates than previously described. Chimerism and depressed precursor cytotoxic T lymphocyte frequencies in tolerant recipients suggest that hematopoietic stem cell engraftment and clonal deletion/anergy are involved in induction of perinatal tolerance(J Thorac Cardiovasc Surg 1997;114:64-75)
Surfactant raw material outlook for the eighties

Over the next decade, the surfactant industry should be able to secure an adequate supply of the raw materials necessary to provide its need for surfactant intermediates. Since the U.S. will continue to rely on foreign imports for marginal crude supplies, periodic disruptions in raw material supply are likely to occur. World crude prices are expected to rise more rapidly than the general U.S. inflation rate and surfactant feedstocks are expected to track world crude prices as a whole. Over the next few years, ethylene prices should increase faster than other surfactant feedstocks. This should occur as a result of natural gas price decontrol and improved ethylene profit margins. Otherwise, in the long term, the major driving force for all three synthetic feedstocks should be the price of world crude. Of course, short term perturbations, e.g., plant shutdowns and over-supply situations, may cause one feedstock or the other to increase at somewhat higher or somewhat lower rates for short periods of time. Natural oils may represent an interesting alternative to crude-oil-based alcohols. Longer term, average prices for natural oils should increase at lower rates than world crude oil. However, natural oil prices have historically been much more cyclic than crude prices and “natural” alcohol producers run the risk of being noncompetitive during tight supply/demand periods.
The exclusion principle for symmetric multi-prize all-pay auctions with endogenous valuations

Abstract This paper explains why contest designers may limit entry into a symmetric multi-prize all-pay auction. The revenue-maximizing size of the group of ‘finalists’ depends on the extent to which prize values decrease or increase with the number of contestants.
The potential for free and mixed convection in sedimentary basins

Free thermal convection and mixed convection are considered as potential mechanisms for mass and heat transport in sedimentary basins. Mixed convection occurs when horizontal flows (forced convection) are superimposed on thermally driven flows. In cross section, mixed convection is characterized by convection cells that migrate laterally in the direction of forced convective flow. Two-dimensional finite-element simulations of variable-density groundwater flow and heat transport in a horizontal porous layer were performed to determine critical mean Rayleigh numbers for the onset of free convection, using both isothermal and semi-conductive boundaries. Additional simulations imposed a varying lateral fluid flux on the free-convection pattern. Results from these experiments indicate that forced convection becomes dominant, completely eliminating buoyancy-driven circulation, when the total forced-convection fluid flux exceeds the total flux possible due to free convection. Calculations of the thermal rock alteration index (RAI=q·∇T) delineate the patterns of potential diagenesis produced by fluid movement through temperature gradients. Free convection produces a distinct pattern of alternating positive and negative RAIs, whereas mixed convection produces a simpler layering of positive and negative values and in general less diagenetic alteration.
Relative Clauses in English conversation: Relativizers, frequency, and the notion of construction

This paper is a usage-based study of the grammar of that set of English Relative Clauses with which a relativizer has been described as optional. We argue that the regularities in the use of relativizers in English can be seen as systematically arising from pragmatic-prosodic factors, creating frequency effects, resulting in some cases highly grammaticized formats: the more the Main Clause and the Relative Clause are integrated with each other, that is, approach monoclausal status, the more likely we are to find no relativizer used; conversely, the more separate the two clauses are, the more likely we are to find an overt relativizer. These findings have led us to suggest that the more monoclausal combinations have become unitary storage and processing chunks. We thus see these findings as a contribution not only to our understanding of Relative Clauses, but to our understanding of syntactic organization in general and of the nature of the grammatical practices in which speakers engage in everyday interactions.
Photosynthetic characteristics of a tropical forest understory herb, Alocasia macrorrhiza, and a related crop species, Colocasia esculenta grown in contrasting light environments

Photosynthetic acclimation to 5 light environments ranging from 2 to 60% full sun was determined in Alocasia macrorrhiza, a shade tolerant species from tropical forest understories, and Colocasia esculenta, a cultivated species which occurs naturally in open marshy areas. Photosynthetic capacities of both species increased nearly 3 fold with increased photon flux density (PFD). In a given environment, however, photosynthetic capacities of C. esculenta were double those of A. macrorrhiza. Stomatal limitations explained only a small part of this difference. Respiration rates and estimated biochemical capacities increased in parallel to photosynthetic capacity. No differences were observed either between species or environments in the ratio of RuBP regeneration capacity to carboxylation capacity as determined from the CO2 dependence response of photosynthesis. Quantum yields of both species decreased only slightly with increasing growth PFD, providing little evidence for photoinhibition at high PFD. The results are discussed in terms of the mechanisms of and limitations on acclimation in these two species.
Convenient synthesis of substituted 3-aminothiophene-2-carbonitriles from α-acetylenic nitriles and their conversion to thieno[3,2-d]pyrimidines

Several novel 2,4,6-trisubstituted thieno[3,2-d]pyrimidines were synthesized from the hitherto unknown 3-amino-5-methyl-(or 5-phenyl)thiophene-2-carbonitriles 7 and 8. o-Aminonitriles 7 and 8 were obtained in a single step by conjugate addition of mercaptoacetonitrile (generated in situ) to substituted acetylenic nitriles 4 and 5 and annelation of the intermediate vinylic thioethers.
Inhibitory effects of ambient levels of solar UV‐A and UV‐B radiation on growth of cucumber

The influence of solar UV-A and UV-B radiation at Beltsville, Maryland, on growth and flavonoid content in four cultivars of Cucumis sativus L. (Ashley, Poinsett, Marketmore, and Salad Bush cucumber) was examined during the summers of 1994 and 1995. Plants were grown from seed in UV exclusion chambers consisting of UV-trans-mitting Plexiglas, lined with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or cellulose acetate to transmit UV-A and UV-B. Despite previously determined differences in sensitivity to supplemental UV-B radiation, all four cultivars responded similarly to UV-B exclusion treatment. After 19-21 days, the four cultivars grown in the absence of solar UV-B (polyester) had an average of 34, 55, and 40% greater biomass of leaves, stems, and roots, respectively, 27% greater stem height, and 35% greater leaf area than those grown under ambient UV-B (cellulose acetate). Plants protected from UV-A radiation as well (Llumar) showed an additional 14 and 22% average increase, respectively, in biomass of leaves and stems, and a 22 and 19% average increase, respectively, in stem elongation and leaf area over those grown under polyester. These findings demonstrate the extreme sensitivity of cucumber not only to present levels of UV-B but also to UV-A and suggest that even small changes in ozone depletion may have important biological consequences for certain plant species.
Capacity and Optimal Collusion Attack Channels for Gaussian Fingerprinting Games

In content fingerprinting, the same media covertext - image, video, audio, or text - is distributed to many users. A fingerprint, a mark unique to each user, is embedded into each copy of the distributed covertext. In a collusion attack, two or more users may combine their copies in an attempt to "remove" their fingerprints and forge a pirated copy. To trace the forgery back to members of the coalition, we need fingerprinting codes that can reliably identify the fingerprints of those members. Researchers have been focusing on designing or testing fingerprints for Gaussian host signals and the mean square error (MSE) distortion under some classes of collusion attacks, in terms of the detector's error probability in detecting collusion members. For example, under the assumptions of Gaussian fingerprints and Gaussian attacks (the fingerprinted signals are averaged and then the result is passed through a Gaussian test channel), Moulin and Briassouli 1 derived optimal strategies in a game-theoretic framework that uses the detector's error probability as the performance measure for a binary decision problem (whether a user participates in the collusion attack or not); Stone 2 and Zhao et al . 3 studied average and other non-linear collusion attacks for Gaussian-like fingerprints; Wang et al. 4 stated that the average collusion attack is the most efficient one for orthogonal fingerprints; Kiyavash and Moulin 5 derived a mathematical proof of the optimality of the average collusion attack under some assumptions. In this paper, we also consider Gaussian cover signals, the MSE distortion, and memoryless collusion attacks. We do not make any assumption about the fingerprinting codes used other than an embedding distortion constraint. Also, our only assumptions about the attack channel are an expected distortion constraint, a memoryless constraint, and a fairness constraint. That is, the colluders are allowed to use any arbitrary nonlinear strategy subject to the above constraints. Under those constraints on the fingerprint embedder and the colluders, fingerprinting capacity is obtained as the solution of a mutual-information game involving probability density functions (pdf's) designed by the embedder and the colluders. We show that the optimal fingerprinting strategy is a Gaussian test channel where the fingerprinted signal is the sum of an attenuated version of the cover signal plus a Gaussian information-bearing noise, and the optimal collusion strategy is to average fingerprinted signals possessed by all the colluders and pass the averaged copy through a Gaussian test channel. The capacity result and the optimal strategies are the same for both the private and public games. In the former scenario, the original covertext is available to the decoder, while in the latter setup, the original covertext is available to the encoder but not to the decoder.
The solubility dependence of canavalin on pH and temperature

Abstract The solubility dependence of canavalin on both pH and temperature was determined. The results are presented both as a function of a single parameter (pH or temperature) and as a function of both. The final pH was studied as a function of initial pH and temperature. An estimate of the heat of crystallization of canavalin was made from the solubility data. The implications of solubility data for crystal growth are discussed.
Differential regulation of H4 histone gene expression in 3T3‐L1 pre‐adipocytes during arrest of proliferation following contact inhibition or differentiation and its modulation by TGFβ1

The aim of this study was to address whether there is a fundamental difference in regulation of histone gene expression in cells that have become quiescent but retain the ability to proliferate, compared with those cells that have differentiated. We compared multiple levels of regulation of histone gene expression during 3T3-L1 pre-adipocyte differentiation. Confluent cells induced to differentiate by treatment with insulin, dexamethasone, and isobutylmethylxanthine initially exhibited an increased proliferative response compared with cells given serum alone. This initial differentiation response was associated with a twofold increase in both histone gene transcription and cellular histone mRNA levels, as well as with enhanced sequence-specific binding of nuclear factors to the proximal cell-cycle-regulatory element of the H4 histone promoter. Transforming growth factor beta 1, an inhibitor of 3T3-L1 differentiation, increased both the percentage of proliferating cells and the cellular levels of histone mRNA when given in addition to serum stimulation, but no enhancement of these parameters was observed upon addition of TGF beta 1 to the differentiation treatment. Interestingly, although TGF beta 1 enhanced binding of nuclear factors to the proximal cell cycle regulatory element of the histone promoter, these protein/DNA interactions were not associated with an increase in histone transcription. Our results are consistent with the down-regulation of histone gene expression at confluency being controlled primarily at the post-transcriptional level, in contrast to an increased involvement of transcriptional down-regulation at the onset of differentiation.
Nondestructive evaluation of the semiconductor interface states' density using the transverse acoustoelectric voltage

Abstract Nondestructive determination of the interface states' density (Dit) is presented. The measurement technique, utilizing the surface acoustic waves, is applied to silicon/thermal oxide structure. The detected signal is the transverse acoustoelectric voltage amplitude (TAV) which is monitored as a function of the applied bias voltage (TAV-V). Dit is measured by comparing the theoretical and experimental TAV-V curves. The calculation procedure of the Dit and the experimental example are presented.
Brain atrophy in relapsing multiple sclerosis: relationship to relapses, EDSS, and treatment with interferon β-1a:

Brain atrophy is a relevant surrogate marker of the disease process in multiple sclerosis (MS) because it represents the net effect of various pathological processes leading to brain tissue loss. There are various approaches to quantifying central nervous system atrophy in MS. We have focused on a normalized measure of whole brain atrophy, the brain parenchymal fraction (BPF). BPF is defined as the brain parenchymal volume, divided by the volume within the surface of the brain. We applied this method to an MRI data set generated during a phase III clinical trial of interferon β-1a (AVONEX). The purpose of the current study is to further explore clinical and MRI correlates of the BPF, particularly as they relate to relapse rate and Kurtzke's Expanded Disability Status Score (EDSS); and to further explore the therapeutic effects observed in interferon β-1a recipients. Of all demographic and disease measures in the clinical trial data base, T2 lesion volume most closely correlated with BPF in cross sectional...
Evolution of North Atlantic ERA40 tropical cyclone representation

[1] The evolving representation of Atlantic tropical cyclones (TCs) in the ERA40 reanalysis dataset from 1957 through 2001 is analyzed using metrics of intensity and the three-dimensional cyclone phase space. On average, TC structural representation within the ERA40 has shifted two Saffir-Simpson (SS) categories over the 45 years. Thus, a category three TC during 1957–1971 is comparable in ERA40 representation to a category one during 1988–2001. Further, the ERA40 does not statistically distinguish between category three and four hurricanes within any given tercile. It is also found that less than seven millibars of ERA40 MSLP separate a category one from a five TC, mean ERA40 MSLP does not always decrease with increasing SS category, and not all SS categories are statistically significant with regard to MSLP. It follows that great caution should be exercised when using ERA40 to diagnose long-term trends in TC structure and intensity within the Atlantic.
Equivalent wave-function approach to the 4 He structure factor and excitation spectrum

A new method for the calculation of the excitation spectrum of liquid $^{4}\mathrm{He}$ is developed based on the wave function ${\ensuremath{\chi}}_{\ensuremath{\alpha}}({x}_{1},{x}_{2})=〈0|T{\ensuremath{\Psi}}^{\ifmmode\dagger\else\textdagger\fi{}}({x}_{1})\ensuremath{\Psi}({x}_{2})|\ensuremath{\alpha}〉$ that is directly related to and completely determines the dynamic structure factor $S(\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}},\ensuremath{\omega})$ of liquid $^{4}\mathrm{He}$, and then employing this method a calculation of the sound spectrum of liquid $^{4}\mathrm{He}$ is performed taking explicitly into account the depletion effect although it is based on the McMillan's data for the ground-state momentum distribution of liquid $^{4}\mathrm{He}$. First, by employing the exponential-decay and effective-mass approximation for the single-particle Green's function, the two-time Bethe-Salpeter integral equation for ${\ensuremath{\chi}}_{\ensuremath{\alpha}}({x}_{1},{x}_{2})$ is transformed into the one-time Schr\"odinger equation. This is thus an approximate Schr\"odinger equation the solutions of which give $S(\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}},\ensuremath{\omega})$ of liquid $^{4}\mathrm{He}$. In the exponential-decay approximation, the numerators of the single-particle Green's function are the true momentum distribution ${N}_{ \mathrm{q}}^{\ensuremath{\rightarrow}}$ of the ground state of liquid $^{4}\mathrm{He}$, which then enters into the Schr\"odinger equation in an essential way. Through this ${N}_{ \mathrm{q}}^{\ensuremath{\rightarrow}}$, both the presence of a condensate and the large depletion of particles from the zero-momentum state in $^{4}\mathrm{He}$ can be properly taken into account. And the effective mass of a helium atom is determined using the McMillan's data and the Lennard-Jones potential. The Schr\"odinger equation is then solved in the limit $k\ensuremath{\rightarrow}0$ using the McMillan's data, and an excitation spectrum of $^{4}\mathrm{He}$ of the form ${[{\ensuremath{\epsilon}}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}^{\ensuremath{'}2}+\frac{2\ensuremath{\alpha}nv(\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}){\ensuremath{\epsilon}}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}^{\ensuremath{'}}}{(1+D)]}}^{\frac{1}{2}}$ in the limit $k\ensuremath{\rightarrow}0$ is obtained, which differs from the Bogoliubov form by the factor ${(1+D)}^{\ensuremath{-}1}$ and the replacement of the bare mass $m$ by the effective mass ${m}^{*}$. $D$, being proportional to $(1\ensuremath{-}\ensuremath{\alpha})n$, represents the depletion effect. The expansion of the above expression gives for the sound velocity of liquid $^{4}\mathrm{He}$ $c=190$ m/sec and verifies the positive phonon dispersion.
Multiscale modelling of dislocation/grain boundary interactions. II. Screw dislocations impinging on tilt boundaries in Al

The interaction of dislocations with grain boundaries (GBs) determines a number of important aspects of the mechanical performance of materials, including strengthening and fatigue resistance. Here, the coupled atomistic/discrete-dislocation (CADD) multiscale method, which couples a discrete dislocation continuum region to a fully atomistic region, is used to study screw-dislocations interacting with Σ3, Σ11, and Σ9 symmetric tilt boundaries in Al. The low-energy Σ3 and Σ11 boundaries absorb lattice dislocations and generate extrinsic grain boundary dislocations (GBDs). As multiple screw dislocations impinge on the GB, the GBDs form a pile-up along the GB and provide a back stress that requires increasing applied load to push the lattice dislocations into the GB. Dislocation transmission is never observed, even with large GBD pile-ups near the dislocation/GB intersection. Results are compared with experiments and previous, related simulations. The Σ9 grain boundary, composed from a more complex set of str...
Eye movements of monkeys during performance of ambiguous cue problems

Eye movements of four stumptailed monkeys were measured during performance of simple and ambiguous form discriminations. Duration of fixations increased during learning of the simple discrimination, whereas the number of shifts in fixation from one stimulus to the other (scanning) increased and subsequently decreased. The asymptotic levels of scanning in both simple and ambiguous discriminations were consistent with predictions generated by a minimum frequency of observing hypothesis. Duration of fixations other than the last fixation preceding the choice response did not change significantly during performance of an ambiguous cue problem in comparison with the simple discrimination, but duration of the last fixation increased significantly. This result was discussed in terms of altered information processing requirements.
Transverse flow measurement using photoacoustic Doppler bandwidth broadening: phantom and in vivo studies

In photoacoustic (PA) imaging of microvascular networks, the transverse component of the blood flow that is perpendicular to the acoustic probing beam is usually dominant. We propose a new method to measure the transverse flow, based on the Doppler bandwidth broadening. The bandwidth broadening is inversely proportional to the transit time spent by the absorbers passing through the focus. Because the photoacoustic signal in one A-scan has a wide band, multiple successive A-scans are used to estimate the relatively small signal variance. Then the bandwidth broadening can be calculated from the standard derivation of the Doppler spectrum. By exploiting the pulse excitation and bidirectional raster motor scanning, threedimensional structural and flow information can be obtained simultaneously. From a flow of a suspension of carbon particles (diameter: 6 μm), transverse flow speeds from 0 to 2.5 mm/s were measured using optical-resolution photoacoustic microscopy. The bandwidth broadening at each speed was in good agreement with the theoretical prediction. The blood flow in a mouse brain was also imaged.
A practical approach to patch testing for cosmetic allergens

Cosmetics are widely used products in our society today. The cosmetic industry is huge and continues to grow. Contact dermatitis to cosmetics is a major issue. Approximately 6% of all individuals patch tested are suspected of having a cosmetic allergic contact dermatitis. Patch testing is the gold standard for evaluating, diagnosing, and directing the management of patients with cosmetic allergic contact dermatitis. Patch testing beyond the standard tray is necessary to accurately diagnose and treat patients, and can be guided, in part, by patient history. Educating patients about the allergens identified via patch testing is crucial in the successful management of these patients.
Integration of hybrid silicon lasers and electroabsorption modulators.

We present an integration platform based on quantum well intermixing for multi-section hybrid silicon lasers and electroabsorption modulators. As a demonstration of the technology, we have fabricated discrete sampled grating DBR lasers and sampled grating DBR lasers integrated with InGaAsP/InP electroabsorption modulators. The integrated sampled grating DBR laser-modulators use the as-grown III-V bandgap for optical gain, a 50 nm blue shifted bandgap for the electrabosprtion modulators, and an 80 nm blue shifted bandgap for low loss mirrors. Laser continuous wave operation up to 45 ?C is achieved with output power >1.0 mW and threshold current of 2GHz with 5 dB DC extinction.
Overweight teens at increased risk for weight gain while using depot medroxyprogesterone acetate.

Abstract Study Objective: To determine if factors such as body mass index (BMI), race, and age are associated with weight gain in adolescents receiving depot medroxyprogesterone acetate (DMPA). Design/Setting: Retrospective chart review at three rural health department family planning clinics and a university-based adolescent clinic in rural eastern North Carolina. Participants: Adolescent females, aged 12–19, who used either oral contraceptive pills (OCPs) or DMPA consistently for the first year of use. Main Outcome Measure: Weight change at one year. Results: A total of 239 adolescent females were included in the analysis; 117 were DMPA users and 122 were OCP users. The mean weight gain for the DMPA group was 8.9 lbs. compared with 4.79 lbs. in the OCP group ( P = .002). The change in BMI from baseline was greater among the DMPA group (1.51 ± 1.94) than the OCP group (.75 ± 1.65), P = .001. After adjusting for age, race, and contraceptive method, initial BMI was associated with weight gain ( P = .009). Conclusions : Adolescent females using DMPA gained significantly more weight over one year than those girls using OCPs. Adolescent females who are overweight at the initiation of DMPA may be more likely to have significant weight gain during the first year of use.
Comparison of the cell cycle and cell migration in the intestinal epithelium of suckling and adult mice.

Die Zellwanderung sowie die Zellvermehrung in den Krypten und auf den Zotten der Dunndarmwandung werden bei saugenden Mausen mit dem Adulttier verglichen. Die scheinbar herabgesetzte Zellmigration ist auf das bei jungen Mausen stattfindende Wachstum der Krypten und Zotten zuruckzufuhren, ist also nicht geringer als bei adulten Tieren.
Active Management of Real Options

Business opportunities to introduce new products at a later date are treated as real options. These real options are modeled as exchange options for which both the underlying and strike assets are risky. The distance to breakeven for an exchange option measures how far a real option is currently expected to be from having a net present value of zero on its expiration date. Because the underlying and strike assets are risky, the distance to breakeven and the value of the real option change randomly during the option's life. The distance to breakeven and the value of the business opportunity may be actively managed during the real option's life. Product design and process design may be used to change the values of the underlying and strike assets while the firm is waiting to introduce the new product. A case study shows that the distance to breakeven is an important measure for a business opportunity, active management can create substantial positive incremental value for good and marginal opportunities, an...