cssi/SciSciGPT-SciSciNet huggingface dataset:
Research frontiers in null model analysis

Null models are pattern-generating models that deliberately exclude a mechanism of interest, and allow for randomization tests of ecological and biogeographic data. Although they have had a controversial history, null models are widely used as statistical tools by ecologists and biogeographers. Three active research fronts in null model analysis include biodiversity measures, species co-occurrence patterns, and macroecology. In the analysis of biodiversity, ecologists have used random sampling procedures such as rarefaction to adjust for differences in abundance and sampling effort. In the analysis of species co-occurrence and assembly rules, null models have been used to detect the signature of species interactions. However, controversy persists over the details of computer algorithms used for randomizing presence-absence matrices. Finally, in the newly emerging discipline of macroecology, null models can be used to identify constraining boundaries in bivariate scatterplots of variables such as body size, range size, and population density. Null models provide specificity and flexibility in data analysis that is often not possible with conventional statistical tests.
Equipment improvement methodology

Today's advanced devices require increasing levels of process complexity. Semiconductor (SC) manufacturers are investigating higher levels of process integration using cluster tools as an approach to decrease process cycle times and increase yields.
A Comparison of Male and Female Student Issues that Affect Enrollment and Retention in Electronics Programs at a For-Profit Institution - Part II

Studying the enrollment and retention of electronics students could improve female enrollment and retention rates, which would help meet the future SMET work-force needs. This paper compared men and women in terms of approachability, concern, and fairness (ACF) of electronics professors and satisfaction with electronics programs. Surveys were administered to 576 students in electronics programs at a for-profit institution. The response rate was 63.9%. The study used 2times3 factorial ANOVAs. There was no statistically significant interaction between gender and program levels or main effects in regard to ACF of electronics professors. Also there was no significant interaction between gender and program levels in regard to satisfaction with electronics programs. Although there was no significant main effect of gender, there was a significant main effect of program level on satisfaction. Both genders at the beginning program level had significantly higher satisfaction ratings than at the middle and at the end program levels
The trade-offs between alternative finite difference techniques used to price derivative securities

Approximating partial differential equations (PDEs) using the finite difference method (FDM) is a common occurrence in contingent claim asset pricing. Past studies have stated that an explicit scheme is being used when a mixed (a combination of an explicit and implicit) scheme is actually being implemented. This study explores the financial and mathematical consequences of using this commonly found method with other FDM approaches. The consequences on valuation and risk management are also briefly addressed.
Natural Competence and Recombination in the Plant Pathogen Xylella fastidiosa

Homologous recombination is one of many forces contributing to the diversity, adaptation, and emergence of pathogens. For naturally competent bacteria, transformation is one possible route for the acquisition of novel genetic material. This study demonstrates that Xylella fastidiosa, a generalist bacterial plant pathogen responsible for many emerging plant diseases, is naturally competent and able to homologously recombine exogenous DNA into its genome. Several factors that affect transformation and recombination efficiencies, such as nutrient availability, growth stage, and methylation of transforming DNA, were identified. Recombination was observed in at least one out of every 10(6) cells when exogenous plasmid DNA was supplied and one out of every 10(7) cells when different strains were grown together in vitro. Based on previous genomic studies and experimental data presented here, there is mounting evidence that recombination can occur at relatively high rates and could play a large role in shaping the genetic diversity of X. fastidiosa.
Comparison of the Small Sample Power of the Chi-Square and Likelihood Ratio Tests of the Assumptions for Stochastic Models

Abstract When applying the Markov model, it is often assumed the transition matrix is stationary and of order one. This article considers the problem of applying the transformed likelihood ratio statistic and the contingency statistic to testing the assumptions of a particular order and of stationarity when the assumptions are not true. A Monte Carlo study of the small sample power of both these test statistics shows that if the true alpha level is kept equal for the two tests they have similar power. However, if the alpha level is set by reference to any standard table of the chi-square distribution the likelihood ratio statistic has larger power.
Two-dimensional electrical stratigraphy of the Siple Dome (Antarctica) ice core

A two-dimensional array of electrical conductivity measurements (ECM) has been used to image the acidity of the Siple Dome (Antarctica) ice core in a vertical plane. Annual layering and possible stratigraphic discontinuities are apparent. A brief disruption to the chemical stratigraphy is detected at 680 m. Below 800 m, weaker layering occurs and is interpreted as the result of post-depositional migration of chemical species. This technique provides a way to observe the horizontal continuity of chemical layers in an ice core and identify some types of flow irregularity.
Incorporation of radioactive sulfur in hair.

The hair of human subjects given radiosulfur-labeled cystine and methionine accumulates much more radioactivity than does the skin. The high levels of radiosulfur do not appear in the hair until approximately 4 to 6 weeks after administration of the labeled compound. Finally, although labeled cystine, methionine, and sulfate are converted to hair keratins in experimental animals, only the first two compounds are utilized in man.
Accessory Growth Factor Requirements of Some Representatives of the Brucella Group

There is little information concerning the accessory growth factor requirements of the Brucella group. In culture mediums composed solely of amino acids, salts, and a non-nitrogenous source of energy, most strains of Brucella either are unable to grow or grow poorly if a large inoculum is used.1,2 The few reports of partial success in cultivating Brucella in synthetic mediums2 have employed one or more of the following technics: a large inoculum, "training," or the use of asparagine, glycerol or lactate, compounds which ordinarily contain growth-promoting substances as impurities. This failure of Brucella to develop in mediums of known chemical composition presents a decided contrast to the prompt growth in infusions of meat, liver and yeast. These sources contain something necessary for growth but the nature of the substances needed and the exact requirements have remained obscure. Preliminary studies have shown that the growth-promoting principles in tissues and yeast may be separated to some extent from other materials and partially purified.3 Kerby4 reported that addition of nicotinic acid and thiamin
Effect of lactic acid on Listeria monocytogenes and Edwardsiella tarda attached to catfish skin.

Abstract This study evaluated the use of lactic acid to decontaminate Listeria monocytogenes and Edwardsiella tarda attached to catfish skin with or without mucus. At the highest inoculum levels (10 4 –10 5 cfu skin −1 ), lactic acid (0·5–2·0%) exposure for 10 min reduced counts of L. monocytogenes firmly attached to catfish skin by 0·9–>1·9 log 10 cfu skin −1 and cells loosely attached by 2·7–>3·7 logs. Counts of E. tarda firmly attached to catfish skin were reduced by 0·9–>3·0 logs and cells loosely attached by 1·5–>3·5 logs. Overall bacterial numbers of lactic acid-treated cells that were firmly attached to skin with mucus were higher than on skin without mucus. Firmly attached L. monocytogenes was more resistant to lactic acid than was firmly attached E. tarda . Catfish skin mucus decreased the antimicrobial effect of lactic acid against attached L. monocytogenes and E. tarda .
Deregulated signal transduction by the K1 gene product of Kaposi’s sarcoma-associated herpesvirus

The Kaposi’s sarcoma (KS)-associated herpesvirus is a lymphotropic virus strongly implicated in the pathogenesis of KS and several lymphoproliferative disorders. The KS-associated herpesvirus K1 gene encodes a transmembrane protein bearing a functional immunoreceptor tyrosine-based activation motif (ITAM)-like sequence; it previously has been proposed to be important in viral tumorigenesis because its expression can trigger cell proliferation in vitro and in vivo. Here we show that expression of the full-length K1 protein can initiate calcium-dependent signal transduction in B cells; however, unlike other ITAM-based signal transduction events, K1 signaling occurs constitutively, in the absence of exogenous crosslinking ligands. This property is caused by its cysteine-rich ectodomain, which when transferred to other consensus ITAMs induces constitutive signaling. Although ITAM-based signaling by K1 involves classical syk and phospholipase C γ2 activation, both ITAM- and syk-independent signaling pathways are activated by K1 expression. These studies indicate that K1 is a deregulated signaling molecule with pleitropic effects that may explain its known growth deregulatory properties.
Robust sampled-data adaptive control of the Rohrs counterexamples

We revisit the Rohrs counterexamples within the context of sampled-data adaptive control. In particular, retrospective cost adaptive control (RCAC) is applied to the sampled continuous-time plant with unmodeled high-frequency dynamics, which involves nonminimum-phase (NMP) sampling zeros. It is shown that, without knowledge of these NMP zeros, RCAC stabilizes the uncertain plant and asymptotically follows the sinusoidal command.
DNA polymerase activity in a repair-deficient human cell line.

Abstract A human low-density-lipoprotein (LDL) receptor-deficient diploid fibroblast cell line (GM1915) was determined to be short patch competent (DNA polymerase-β) and long patch deficient (DNA polymerase-α) for DNA excision repair. Analysis of DNA from GM1915 cells or from WI38 control cells, following treatment with a mutagen known to initiate long patch excision repair, showed that GM1915 cells exhibited decreased resynthesis of oligonucleotide segments excised during repair. When cells deficient in DNA polymerase-α activity were permeabilized to permit LDL entry, repair synthesis immediately increased. These data suggest that DNA polymerase-α is not activated by mutagen treatment in GM1915 cells and that introduction of LDL into the cells results in activation of the enzyme.
Breeding CWG-R crested wheatgrass for reduced-maintenance turf

Using reduced-maintenance turfgrass as an alternative to current high-maintenance turfgrass species would conserve resources, reduce labor, and potentially reduce pollutants in the environment. CWG-R is an experimental population of crested wheatgrass [Agropyron cristatum (L.) Gaertn.] from Iran that has shown potential as a low-maintenance turf. The objective of this research was to estimate the genetic variation for turf traits within the CWG-R population when evaluated under a reduced-maintenance regimen. Ninety CWG-R clonal lines were established in 1998 near Logan, UT, as spaced-plant plots in a RCB design with four replicates. Maintenance of 50% ET 0 replacement, 97.74 kg of nitrogen ha -1 yr -1 , and mowing at 7.62 cm was approximately 40% lower than typical for high-input Kentucky bluegrass (Poa pratensis L.) turf. Critical turf traits, including spring regrowth, season-long (March-October) and mid-summer (June-July) turf quality, color, and rhizomatous spread were evaluated in 1999 and 2000. Significant genetic variation among clonal lines was evident with broad-sense heritabilities of 0.65, 0.76, 0.45, and 0.76 for spring regrowth, season-long turf quality, color, and rhizomatous spread, respectively. Several clonal lines remained green throughout the summer months and maintained acceptable turf quality and color ratings during the critical mid-summer period. The high broad-sense heritability estimates within this population indicate potential for successful improvement of critical turf traits by phenotypic selection. These results indicate that that CWG-R could be an important low-maintenance turf-type crested wheatgrass germplasm.
Electric Currents Accompanying Tornado Activity

Measurements of the magnetic field and earth current in the vicinity of a tornado show large steplike deflections coincident with the touching down of the funnel. Calculations with a simple current model indicate that a minimum current of several hundred amperes must be postulated to account for the observed deflection in magnetic field. The existence of a steady current of 225 amperes for a period of about 10 minutes provides joule heat at the rate of approximately 10(10) joules per second, and involves a total charge transfer of 135,000 coulombs. The calculations imply that a tornado is electrically equivalent to several hundred isolated thunderstorm cells active simultaneously.
Ramp-Rate Effects on Transient Enhanced Diffusion and Dopant Activation

Use of high ramp rates (>400°C/s) in rapid thermal annealing after ion implantation leads to experimentally observed improvements in junction depth and the reverse narrow-channel effect. However, a straightforward explanation for this effect has been lacking. Via modeling, we find that increasing the heating rate permits clusters with dissociation energies lower than the maximum of 3.5-3.7 eV to survive to higher temperatures. This improved survival delays the increase in Si interstitial concentrations near the top of an annealing spike, which decreases the profile spreading.
Surface-imprinted silica particles: the effects of added organosilanes on catalytic activity

Abstract Silicate surfaces were molecularly imprinted with a surfactant derivative of an α-chymotrypsin transition state analog (TSA) during particle formation in a water-in-oil microemulsion. The organosilanes N -(3-aminoethylaminomethyl)-phenyltrimethoxysilane (PEDA), carboxyethylsilanetriol (CTES), and N -(3-triethoxysilylpropyl)-4,5-dihydroimidazole (IPTES) were added along with tetraethoxysilane (TEOS) to imprint the chemical functionality of the imprint molecule. Surfaces imprinted with N -α-decyl- d -phenylalanine-2-aminopyridine enantioselectively catalyzed the hydrolysis of benzoyl- l -arginine- p -nitroanilide ( l -BAPNA). No hydrolysis of d -BAPNA was observed. The catalytic activity of surface-imprinted particles formed with TEOS and PEDA was significantly greater than that of surface-imprinted particles formed with TEOS and IPTES. Particles formed with added 10 mol% (total silica) of PEDA hydrolyzed dl -BAPNA at a rate equivalent to that of surface-imprinted particles formed with the mixture of 5 wt% (total silica) of PEDA, CTES, and IPTES suggesting a cooperative effect with the organosilane mixture that promoted catalytic activity.
Breathing fluctuations in position-specific DNA base pairs are involved in regulating helicase movement into the replication fork

We previously used changes in the near-UV circular dichroism and fluorescence spectra of DNA base analogue probes placed site specifically to show that the first three base pairs at the fork junction in model replication fork constructs are significantly opened by “breathing” fluctuations under physiological conditions. Here, we use these probes to provide mechanistic snapshots of the initial interactions of the DNA fork with a tight-binding replication helicase in solution. The primosome helicase of bacteriophage T4 was assembled from six (gp41) helicase subunits, one (gp61) primase subunit, and nonhydrolyzable GTPγS. When bound to a DNA replication fork construct this complex advances one base pair into the duplex portion of the fork and forms a stably bound helicase “initiation complex.” Replacement of GTPγS with GTP permits the completion of the helicase-driven unwinding process. Our spectroscopic probes show that the primosome in this stable helicase initiation complex binds the DNA of the fork primarily via backbone contacts and holds the first complementary base pair of the fork in an open conformation, whereas the second, third, and fourth base pairs of the duplex show essentially the breathing behavior that previously characterized the first three base pairs of the free fork. These spectral changes, together with dynamic fluorescence quenching results, are consistent with a primosome-binding model in which the lagging DNA strand passes through the central hole of the hexagonal helicase, the leading strand binds to the “outside” surfaces of subunits of the helicase hexamer, and the single primase subunit interacts with both strands.
Understanding and Mapping Institutional Impediments to Walking and Bicycling to School: A Case Study of Hillsborough County, Florida

The Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) legislation calls for the establishment of a Safe Routes to School program in each state that is funded for the five fiscal years from 2005 through 2009. States are required to spend between 70% and 90% for infrastructure and between 10% and 30% on noninfrastructure programs. For each of these components of the program to be successful, the built environment of the community surrounding the school needs to support all modes of travel. Much of the emphasis in Safe Routes to School programs has focused on increasing walking in neighborhoods with the characteristics that support walking, such as high-density residential areas close to schools and connected grid and pedestrian amenities. Using Hillsborough County, Florida, as a case study, this paper focuses on barriers to walking and bicycling to school by examining how decisions about school siting, school attendance boundaries, street network characteristics, and other factors controlled by local governments and school boards affect the potential for children to walk to school. Language: en
A homework exercise in finite elements

We suggest an exercise which illustrates many of the fundamental ideas of finite elements, and is nevertheless easily programmed and quickly solved. It is governed by a partial differential equation on a circular region, but by maintaining symmetry the stiffness matrix becomes small and tridiagonal. The accuracy of linear elements can be studied in detail, and a straightforward extension leads to the eigenvalue problem, elements of higher degree, numerical integration, isoparametric elements, and a simple example in plasticity.
In-situ monitoring of slow light structures in dye-doped polymer waveguide materials

In this work, we describe a technique for positioning the passband and monitoring the slowing factor of Moire gratings written into PMMA-DR1 waveguides during fabrication. Slow light structures made with material platforms such as silicon must fabricated before their actual slowing properties can be measured. In our dye doped polymer waveguides, the slowing can be decided beforehand and the fabrication controlled to achieve the desired performance figure. The resulting group velocity slowing in the composite waveguide can be controlled by varying the index contrast of the grating. In dye-doped polymer materials we use, the index contrast can be changed using the process of irreversible photobleaching. Our technique uses a broadband source to monitor the reflectance spectrum of the grating and the delay of the structure is determined from this measurement. The theory behind the technique is reviewed and results are presented for a Moire grating written into waveguides fabricated in the dye-doped polymer material system, PMMA-DR1.
Deuterium and impurity deposition profiles in the plasma edge of ISX-B

Abstract Quantitative radial profiles have been determined for deuterium and heavy impurities ( A ⩾ 12 ) trapped on deposition probes in the plasma edge of ISX-B. Silicon samples were exposed to 1, 4 and 12 tokamak discharges at distances of 10 to 50 mm behind the limiter radius for both ohmic and beam-heated plasmas. The species, quantities and saturation behavior of the principal impurities were determined by ion backscattering and channeling analysis, while nuclear reaction D( 3 He, p) 4 He and damage analyses were used for the detection and depth profiling of deuterium. The components of stainless steel (Fe, Cr, Ni) were found to increase linearly with the number of discharges, while radial profiles for oxygen and D showed saturation effects in a single discharge. Estimates of D energies and both impurity and D fluxes in the plasma-edge are given for ohmically heated and 350 kW neutral beam injected discharges.
Spanning Borders and Boundaries: Sociology for the Twenty-First Century

Abstract The 1999 NSCA Presidential Address looks at current research in sociology and related disciplines to illustrate the ways in which it is spanning geographic and paradigmatic borders and boundaries moving toward an inclusive race/ethnicity-class-gender scholarship. Late 20th Century perspectives are contrasted with those that prevailed at mid-century.
Robust front-end processing for speaker identification over extremely degraded communication channels

Effective front-end processing, which often involves feature extraction and speech activity detection (SAD), is essential for robustness in speech systems. In this study, we propose an unsupervised SAD scheme based on four different speech voicing measures which are combined with a perceptual spectral flux feature. Effectiveness of the proposed scheme is evaluated and compared against several commonly adopted unsupervised SAD methods under actual harsh acoustic conditions. As an example application, we also evaluate performance of the proposed SAD in the context of an i-vector based speaker identification (SID) system, where the recently introduced mean Hilbert envelope coefficients (MHEC) are benchmarked against conventional MFCCs. Long and spontaneous conversational audio recordings from DARPA program RATS (Phase-I) are used in our evaluations. Experimental results indicate that the proposed SAD solution is highly effective and provides superior performance compared to other unsupervised SAD techniques considered. In addition, it is shown that MHECs are effective alternatives to MFCCs for SID tasks under severe degraded channel conditions.
Soy protein fortification affects sensory, Chemical, and microbiological properties of dairy yogurts

Chemical, microbiological, and sensory properties for low fat yogurts fortified with 0, 1, 2.5, or 5% soy protein concentrate were determined through 1 mo storage at 5 degrees C. Yogurts were adjusted to equivalent total solids with nonfat dried milk. Microbiological counts, fermentation time, and final developed acidity were not affected by soy protein. Instrumental viscosity and sensory thickness, soy aroma, and soy flavor increased with soy protein addition (P less than or equal to 0.05). Soy flavor and aroma did not increase with storage time. Yogurt with 5% soy protein was darker, more chalky, and less sweet compared to control yogurt or yogurts with lower concentrations of soy protein (P less than or equal to 0.05). Yogurts with 1 or 2.5% soy protein were most similar to control yogurt.
The social constitution of action. Objectivity and explanation

It is argued in this article that human actions may be said to be socially constituted : as being behavior that is constituted as human action by social relations and by participant agent and collective representations of behavior. In contrast to recent social constructionist accounts, it is argued that the social constitution of action does not pose any threat to the objectivity of classification or explanation in social psychological science. It does mark some significant ontological differences between natural and social psychological phenomena that have implications for the university and generality, but not the adequacy, of explanations of socially constituted human actions.
ADDITIONAL PERSPECTIVES ON SIMPLE QUANTITATIVE GAIT ANALYSIS

Stuberg, Straw, and Devine (1990) and then Hicik and Radil (1990) present some interesting idormation regarding several relatively simple alternatives for quantitative gait analysis. The purpose of this note is to provide additional perspectives on simple quantitative gait analysis, particularly as it relates to patients with hemiparetic stroke. For such patients the documentation of speed alone can be very useful. Speed is a sensitive and valid measure (Mizrahi, Susak, Heller, & Najenson, 1982; Wade, Wood, Heller, Maggs, & Hewer, 1987) that correlates significantly with other measures such as cadence, appearance, independence, and distance (Bohannon, 1987, 19891, is important in a community setting (Robinett & Vondran, 1988), and can be determined easily with a stopwatch as patients walk over a known distance. As stride length or cadence can be determinants of walking speed oE hemiparetic stroke patients (Nakamura, Handa, Watanabe, & Morohashi, 1988), theu measurement too can be important. A large proportion of such patients walk below the 40 m.min.-' velocity at which Stuberg, Straw, and Devine (1990) found length of step could be measured reliably by a single observer with a tape recorder. When the patient's speed precludes the accurate observation of foot placement on a grid, a second observer can be employed. In a clinical setting in which I once worked, I Found it almost impossible to use the observational grid method of Robinson and Smidt (1981) with patients who had had hemiparetic stroke (in spite of theu slow speed). However, by using a separate observer to record each (left or right) foot's placement on the grid, foot placement could be documented for the reliable measurement of stride length.
Modes for gain maximization of the free electron laser in the low-gain, small-signal regime

Abstract We calculate the maximum gain obtainable from a uniform-wiggler FEL in the small-signal, small-gain regime, taking diffraction into account. The gain and the electron energy detuning at which it is maximal are calculated as a function of the electron-beam Fresnel number F . Gain maximization requires appropriate choice of a resonator. The mirrors need to have larger curvature and aberrations when F is small. In an appendix we generalize our gain formula to a nonuniform wiggler.
APPLICATION OF MARKET MECHANISMS TO POLLUTION

The authors indicate how science and social science can be combined to assess the range and effectiveness of policy alternatives available to environmental decision-makers. They focus on cost-effective regulatory alternatives to the Los Angeles particulate sulfate problem. Both sciences are applied to the relationship of emissions to pollution levels and environmental quality. They reject the notion that a simple reduction in emissions leads to a commensurate reduction in pollution levels. The problem of applying licenses and emissions fees are reviewed, as are the difficulties of political feasibility.
Three-dimensional Numerical Study of the Mixing Behaviour of Twin-screw Elements

Abstract In this work the numerical modeling of the flow inside co-rotating twin-screw extruders is performed and solutions are analyzed to determine the mixing behavior of two screw elements: conveying and mixing elements. The flow around intermeshing screws is computed using an immersed boundary finite element method capable of dealing with complex moving solid boundaries. The flow is considered isothermal and the material behaves as a generalized non-Newtonian fluid. Because the viscosity depends on the shear rate, solutions will be shown for various rotation velocities of the screw. The 3D solutions are then analyzed in order to determine various parameters characterizing the flow mixing such as the residence time and the linear stretch. Residence time distribution inside the twin-screw extruder is first computed by using a particle tracking algorithm based on a fourth order Runge-Kutta method. A large number of particles are tracked inside the extruder and the resulting particle data is used to deter...
Minimum Variance Unbiased Estimation of Software Reliability

As the formal methods of proving correctness of a computer program are still very inadequate, in practice when a new piece of software is developed and all obvious errors are removed, it is tested with different (random) inputs in order to detect the remaining errors and assess its quality. We suppose that whenever the program fails the error causing the failure can be detected and removed correctly. Thus, the quality of the software increases as testing goes on. In this paper, we consider two different models and present the minimum variance unbiased estimators of the expected failure rate of the revised software at any time of testing t, based on the data generated up to that point.
Monoclonal Antibody Based Antigenic Mapping of Norovirus GII.4-2002

Noroviruses are the primary cause of epidemic gastroenteritis in humans, and GII.4 strains cause ∼80% of the overall disease burden. Surrogate neutralization assays using sera and mouse monoclonal antibodies (MAbs) suggest that antigenic variation maintains GII.4 persistence in the face of herd immunity, as the emergence of new pandemic strains is accompanied by newly evolved neutralization epitopes. To potentially identify specific blockade epitopes that are likely neutralizing and evolving between pandemic strains, mice were hyperimmunized with GII.4-2002 virus-like particles (VLPs) and the resulting MAbs were characterized by biochemical and immunologic assays. All of the MAbs but one recognized GII.4 VLPs representing strains circulating from 1987 to 2009. One MAb weakly recognized GII.4-1987 and -1997 while strongly interacting with 2002 VLPs. This antibody was highly selective and effective at blocking only GII.4-2002-ligand binding. Using bioinformatic analyses, we predicted an evolving GII.4 surface epitope composed of amino acids 407, 412, and 413 and subsequently built mutant VLPs to test the impact of the epitope on MAb binding and blockade potential. Replacement of the 2002 epitope with the epitopes found in 1987 or 2006 strains either reduced or ablated enzyme immunoassay recognition by the GII.4-2002-specific blockade MAb. These data identify a novel, evolving blockade epitope that may be associated with protective immunity, providing further support for the hypotheses that GII.4 norovirus evolution results in antigenic variation that allows the virus to escape from protective herd immunity, resulting in new epidemic strains.
Consequences of emotional stimuli: age differences on pure and mixed blocks of the emotional Stroop

Background Studies of aging and emotion suggest that older adults show diminished responsiveness to negative information, possibly resulting from increased emotion regulation, but the mechanisms accounting for this effect are uncertain.
New Product Diffusion with Influentials and Imitators

We model the diffusion of innovations in markets with two segments: influentials who are more in touch with new developments and who affect another segment of imitators whose own adoptions do not affect the influentials. This two-segment structure with asymmetric influence is consistent with several theories in sociology and diffusion research, as well as many “viral” or “network” marketing strategies. We have four main results. 1 Diffusion in a mixture of influentials and imitators can exhibit a dip or “chasm” between the early and later parts of the diffusion curve. 2 The proportion of adoptions stemming from influentials need not decrease monotonically, but may first decrease and then increase. 3 Erroneously specifying a mixed-influence model to a mixture process where influentials act independently from each other can generate systematic changes in the parameter values reported in earlier research. 4 Empirical analysis of 33 different data series indicates that the two-segment model fits better than the standard mixed-influence, the Gamma/Shifted Gompertz, and the Weibull-Gamma models, especially in cases where a two-segment structure is likely to exist. Also, the two-segment model fits about as well as the Karmeshu-Goswami mixed-influence model, in which the coefficients of innovation and imitation vary across potential adopters in a continuous fashion.
Targeted localized degradation of Paired protein in Drosophila development

Abstract Background: Selective spatial regulation of gene expression lies at the core of pattern formation in the embryo. In the fruit fly Drosophila , localized transcriptional regulation accounts for much of the embryonic pattern. Results: We identified a gene, partner of paired ( ppa ), whose properties suggest that localized receptors for protein degradation are integrated into regulatory networks of transcription factors to ensure robust spatial regulation of gene expression. We found that the Ppa protein interacts with the Pax transcription factor Paired (Prd) and contains an F-box, a motif found in receptors for ubiquitin-mediated protein degradation. In normal development, Prd functions only in cells in which ppa mRNA expression has been repressed by another segmentation protein, Even-skipped (Eve). When ppa was expressed ectopically in these cells, Prd protein, but not mRNA, levels diminished. When ppa function was removed from cells that express prd mRNA, Prd protein levels increased. Conclusions: Ppa co-ordinates Prd degradation and is important for expression of Prd to be correctly localized. In the presence of Ppa, Prd protein is targeted for degradation at sites where its mis-expression would disrupt development. In the absence of Ppa, Prd is longer-lived and regulates downstream target genes.
Benchmark experiments for space Reactor neutron shielding of mission electronics

Experiments and calculations simulating the neutron shadow shield for a reactor-powered space vehicle are described, including calculations for a variety of shield configurations and materials, and an experimental benchmark test using a bare fast reactor.
Developmental Changes in Questioning Strategies during Adolescence

Males andfemales from early, middle, and late adolescent age groups were tested with three arrays in a modified version of a 20 Questions problem-solving task The arrays differed by perceptual and conceptual categorical contrasts. The participants'questions were examined to determine (a) how efficiently they used the categorical information present in the arrays and (b) the frequencies of different question types. Analysis showed that the arrays varied in how efficiently they were solved and that late adolescents were the most efficient at reducing alternatives by their third question. Question types differed predictably by array, exceptfor a slight bias favoring conceptual category questions for an array with a balanced mixture ofperceptual and conceptual properties. Developmental differences in both efficiency and question type seem related, and middle adolescent males exhibited a high frequency of syncretic questions, which may constitute aform of risk taking.
Radiofrequency Ablation of Adrenal Tumors and Adrenocortical Carcinoma Metastases

Patients with primary and metastatic adrenocortical carcinoma (ACC) have limited treatment options. Chemotherapy with mitotane has shown limited efficacy and radiation therapy has had little significant effect on the natural course of this disease.1–5 Repeated surgical resection is used in selected patients and is associated with long-term survival. Image-guided local tumor ablation with radiofrequency current may offer a minimally invasive and safe treatment option for patients who have had multiple recurrent surgeries, who are not ideal surgical candidates, or for whom the proven benefits of surgery do not outweigh the risks. Recent advancements in radiofrequency thermal ablation (RFA) make local tissue destruction possible in a rapid, predictable, and inexpensive manner with minimal morbidity and a short recovery time. Radiofrequency ablation has been applied safely and effectively to benign bone tumors, malignant primary and meta-static liver tumors, and renal cell carcinoma.6–11 If aggressive surgical resection improves survival in certain clinical settings, it is possible that local tissue destruction also might benefit specific patients. Radiofrequency ablation may improve survival for patients with solitary or small liver tumors compared with no treatment or medical management alone, although the long-term data are not yet available. This procedure may also provide a treatment option for patients with inoperable liver tumors.8–11
Movement-relevant Theory: Rethinking Social Movement Scholarship and Activism

The dominant American social movement scholarship has become detached from the concerns of actual social movements. But the dramatic growth of social movement activity in recent years, especially the global justice movement, is creating the conditions for an emerging new direction in social movement scholarship which prioritizes the relevance of such work to the movements themselves. A problem in the current social movement literature is that the different schools of thought tend to overemphasize particular variables and pit them against one another. Rather than simply seeking to emphasize a different variable in the lifecycle of a social movement, a movement-relevant approach has the potential to transcend these schisms (such as structure versus culture). At the same time, this approach does not categorically reject earlier theoretical perspectives, but instead seeks to glean what is most useful for movements from these earlier works. Likewise, this emergent direction entails a dynamic engagement with th...
Classification of temporal patterns in dynamic biological networks

A general method is presented to classify temporal patterns generated by rhythmic biological networks when synaptic connections and cellular properties are known. The method is discrete in nature and relies on algebraic properties of state transitions and graph theory. Elements of the set of rhythms generated by a network are compared using a metric that quantifies the functional differences among them. The rhythms are then classified according to their location in a metric space. Examples are given, and biological implications are discussed.
"Leaky" Rationality: How Research on Behavioral Decision Making Challenges Normative Standards of Rationality.

For more than 30 years, decision-making re- search has documented that people often violate various principles of rationality, some of which are so fundamental that theorists of rationality rarely bother to state them. We take these characteristics of decision making as a given but argue that it is problematic to conclude that they typically represent departures from rationality. The very psycho- logical processes that lead to ''irrational'' decisions (e.g., framing, mental accounting) continue to exert their in- fluence when one experiences the results of the decisions. That is, psychological processes that affect decisions may be said also to ''leak'' into one's experience. The implica- tion is that formal principles of rationality do not provide a good enough normative standard against which to assess decision making. Instead, what is needed is a substantive theory of rationality—one that takes subjective experience seriously, considers both direct and indirect consequences of particular decisions, considers how particular decisions fit into life as a whole, and considers the effects of decisions on others. Formal principles may play a role as approxi- mations of the substantive theory that can be used by the- orists and decision makers in cases in which the formal principles can capture most of the relevant considerations and leakage into experience is negligible.
Age differences in default mode activity on easy and difficult spatial judgment tasks

The default network is a system of brain areas that are engaged when the mind is not involved in goal-directed activity. Most previous studies of age-related changes in default mode processing have used verbal tasks. We studied non-verbal spatial tasks that vary in difficulty. We presented old and young participants with two spatial judgment tasks: an easy categorical judgment and a more demanding coordinate judgment. We report that (a) Older adults show markedly less default network modulation than young on the demanding spatial task, but there is age equivalence on the easy task; (b) This Age x Task interaction is restricted to the default network: Brain areas that are deactivated by the tasks, but that are outside the default network, show no interaction; (c) Young adults exhibit significantly stronger functional connectivity among posterior regions of the default network compared with older adults, whereas older adults exhibit stronger connectivity between medial prefrontal cortex and other sites; and (d) The relationship of default activity to reaction time performance on the spatial tasks is mediated by age: in old adults, those who deactivate the default network most also perform best, whereas the opposite is true in younger adults. These results extend the findings of age-related changes in default mode processing and connectivity to visuo-spatial tasks and demonstrate that the results are specific to the default network.
An empirical basis for determining the multidimensional structure of leisure

Abstract To explain fully the structural nature of leisure, there is a need to use strategies that are both direct in approach and empirical in nature. This study examined such a strategy; its purpose was to illustrate a technique for analyzing the dimensionality of leisure. Multidimensional scaling (MDS) was used to develop a potential set of traits that are descriptive of leisure activities and multiple regression provided a means for a direct empirical assessment of this set of traits. It was concluded that (a) multidimensional scaling provides a useful tool for direct investigation of the structural nature of leisure, and (b) multiple regression can provide an empirical alternative to visual interpretations of the results.
Correlation between directly measured and indirectly estimated sinoatrial conduction time in children.

Abstract The indirectly estimated sinoatrial conduction time has been widely used in children to assess sinus node (SN) function, but has never been validated in pediatric patients. Using a standard quadripolar catheter with high amplification and low-pass filters, SN electrograms were recorded in 11 of 26 (42%) pediatrie cardiac patients (age range 10 months to 18 years) with normal SN function. The sinoatrial conduction time was measured directly from the SN electrogram and estimated indirectly by the premature stimulation and continuous pacing methods. The direct sinoatrial conduction time (15 to 91 ms) in these 11 patients (ages 1 to 18 years) correlated well with that estimated by the premature stimulation method (r = 0.81, n = 9, p
Signal Processing With Acousto-Electric Surface Acoustic Wave (SAW) Devices

Interest in acoustoelectric SAW devices has grown rapidly in the past few years. One of the reasons for this expansion is the potential capability of these devices to perform sophisticated real-time programmable signal processing. The essential ingredient in these devices is the acoustoelectric interaction of free carriers in a semiconductor with the evanescent RF electric fields accompanying surface acoustic waves (SAWs) propagating on a nearby piezoelectric substrate. Coupling of the electric fields from the piezoelectric to the semiconductor takes place across a narrow (-300 nm) air gap. The complexity of the semiconductor ranges from the simple distributed surface varactor of the convolver, to the high density diode array (few pm periodicity) of the acoustoelectric devices with charge storage, to the fully integrated microcircuit of the complex charged-coupled devices (SAW/CCD). The convolver provides, in a compact structure, matched filtering with a processing gain in excess of 30 dB and bandwidths up to 200-MHz for spread-spectrum waveforms, a function which would otherwise require a large digital machine operating at 1011 arithmetic operations per second. Other devices, newer than the convolver, are being explored which promise increasingly sophisticated signal processing capability. For instance, the memory correlator and the SAW/CCD programmable matched filter can be used in radar receivers in place of fixed matched filters to reduce the time spent in system alignment and to introduce programmability; the integrating correlator and the SAW/CCD accumulating correlator have the potential to be used in spread-spectrum systems for the correlation of very long (A¢â¬â?msec) waveforms and the coherent integrator could provide a programmable burst-waveform processor for pulse-Doppler radar. As examples of the large variety of acoustoelectric SAW signal processors, three specific air-gap devices, the convolver, the memory correlator, and the coherent integrator will be described.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Synthesis and evaluation in monkey of two sensitive 11C-labeled aryloxyanilide ligands for imaging brain peripheral benzodiazepine receptors in vivo.

We sought to develop 11C-labeled ligands for sensitive imaging of brain peripheral benzodiazepine receptors (PBR) in vivo. Two aryloxyanilides with high affinity for PBR were identified and synthesized, namely, N-acetyl-N-(2-methoxycarbonylbenzyl)-2-phenoxyaniline (3, PBR01) and N-(2-methoxybenzyl)-N-(4-phenoxypyridin-3-yl)acetamide (10, PBR28). 3 was hydrolyzed to 4, which was esterified with [11C]iodomethane to provide [11C]3. The O-desmethyl analogue of 10 was converted into [11C]10 with [11C]iodomethane. [11C]3 and [11C]10 were each injected into monkey to assess their brain kinetics with positron emission tomography (PET). After administration of either radioligand there was moderately high brain uptake of radioactivity. Receptor blocking and displacement experiments showed that a high proportion of this radioactivity was bound specifically to PBR. In monkey and rat, 3 and 10 were rapidly metabolized by ester hydrolysis and N-debenzylation, respectively, each to a single polar radiometabolite. [11C]3...
Religion and the Case Against Ancient Liberty: Benjamin Constant’s Other Lectures

Benjamin Constant’s famous lecture comparing ancient and modern liberty can be better understood if it is read alongside a set of unpublished lectures on ancient religion that he delivered one year earlier. Those lectures suggest that Constant’s commitment to modern liberty was based in part on his deep anxieties about religious freedom, and that he valued religious freedom because he thought the “religious sentiment” was an important manifestation of a natural human capacity for self-development. In putting religion and self-development at the heart of his vision, he tried to show that modern liberty could have a positive moral or spiritual purpose beyond merely assuring people freedom from interference in the pursuit of their interests.
Pulse generators using chemical double layer capacitor technology

The authors describe low-voltage pulsers which combine both batteries and chemical double-layer (CDL) capacitors to achieve long-duration (>1 s), high-power pulses which could be suitable for powering a number of devices such as EMLs, solid-state laser arrays and magnetic-field coils. Several laboratory devices are described ranging from Marx circuits to Type-A Guillemin lines. Since CDL capacitors are inherently low-voltage devices with modest equivalent series resistance (ESR), restrictions exist on operating voltages, allowable ESR, pulser impedance and the absolute value of the capacitors. These parameter restrictions are discussed in terms of what can be achieved as a result of research in progress. >