cssi/SciSciGPT-SciSciNet huggingface dataset:
Seeing Merit as a Vehicle for Opportunity and Equity: Youth Respond to School Choice Policy

School choice policy is ubiquitous in urban school districts. Evidence suggests that it has not fully delivered on its proponents’ promises of equitable educational opportunity. While scholars and policymakers scrutinize data to determine school choice’s equity outcomes, little attention has been paid to how school choice policy directly influences youth understanding of educational equity and opportunity. This study therefore explores how youth who engage with school choice policy come to understand and act upon the distribution of educational opportunities, and the extent to which their understandings and actions vary by social identity, family resources, school resources and admissions outcomes. 36 youth, engaged in the high school choice process, participated in this study, which is guided by policy enactment theory. Across subgroups, participants overwhelmingly valued merit as the best principle by which to distribute educational opportunity. Alongside this near-universal embrace of merit and widespread participation in choice policy-required actions, those who accessed the highest-performing schools often did so by activating non-academic resources that required financial capital. These findings highlight a shared ritual that serves to instantiate and reinforce ideals of meritocracy. Findings inform our discussion of school choice policy’s educational equity and civic implications.
Learning Latent Multi-Criteria Ratings from User Reviews for Recommendations

Multi-criteria recommender systems have been increasingly useful for helping consumers identify the most relevant items based on different dimensions of user experiences and highlighting their most valued features. Therefore, researchers have proposed various multi-criteria models to improve recommendation performance. However, most of the existing methods utilize only multi-criteria ratings explicitly provided by the users. Note that explicit multi-criteria ratings are sparse and have the problem of missing values. User reviews, on the other hand, contain richer information of user experiences and reveal multi-dimensional user preferences. Therefore, we propose to use latent multi-criteria ratings generated from user reviews, as opposed to explicit multi-criteria ratings, to provide recommendations and capture latent complex heterogeneous user preferences. Specifically, we propose two novel models for the latent multi-criteria rating generation process: the one-stage model LatentMC-1S that utilizes document hashing method to directly compute latent ratings and the two-stage model LatentMC-2S that uses GRU and Gumbel-Softmax for indirect rating generation. Extensive experiments show that the proposed latent multi-criteria rating approaches outperform explicit ratings across different datasets and performance measures. We also show that latent multi-criteria ratings could be used for imputing missing explicit multi-criteria ratings and thus further improving multi-criteria recommender systems.
The Role of Interaural Differences, Head Shadow, and Binaural Redundancy in Binaural Intelligibility Benefits Among School-Aged Children.

In complex listening environments, children can benefit from auditory spatial cues to understand speech in noise. When a spatial separation is introduced between the target and masker and/or listen...
Towards Robust VSLAM in Dynamic Environments: A Light Field Approach

There is a general expectation that robots should operate in urban environments often consisting of potentially dynamic entities like people, automobiles etc. Dynamic objects pose challenges to visual SLAM algorithms by introducing errors into the front-end. This paper presents a Light Field powered SLAM front-end which is robust to dynamic environments. A Light Field captures a bundle of light rays emerging from a single point in space, allowing us to see through dynamic objects occluding the static background via Synthetic Aperture Imaging (SAI). We detect apriori dynamic objects using semantic segmentation and perform semantic guided SAI on the Light Field acquired from a linear camera array. The combined use of SAI with semantic segmentation results in a significant reduction of the dynamic content and also adds valuable observations from the occluded static parts of the scene. The GPU implementation of our algorithm facilitates running at a speed of ~6 fps. We demonstrate considerable improvement in robustness and accuracy of pose estimation in dynamic environments by comparing it with state of the art VSLAM algorithms. Link to video demo: https://rb.gy/mwt5tv
Mesh Size Control of Polymer Fluctuation Lubrication in Gemini Hydrogels

Abstract Polyacrylamide (PAAm) hydrogels are excellent synthetic materials for in vitro biotribology studies. Recent work with hydrogels sliding in a Gemini contact has revealed unique friction behavior at low speed that is contrary to the classic Stribeck curve. In these interfaces the friction coefficients are minimum at low speeds and appear to be speed-independent. In this report, we investigate the role of mesh size, ξ , on the low friction regime, termed thermal fluctuation lubrication, and we also explore the origins of a transition from this behavior at higher speeds to polymer relaxation lubrication. PAAm hydrogels of varying concentration were prepared and tested in a Gemini configuration using a pin-on-disk microtribometer with an applied load of 2 mN and over a range of sliding speeds from 0.03 mm/s to 100 mm/s. We found that increasing mesh size or decreasing polymer concentration promotes lower friction coefficients. Many samples underwent a transition from a low friction behavior to an increasing friction coefficient with increasing sliding speed that scaled with speed to the 1/2 power. This transition speed was found to correlate with the mesh size and relaxation time of the polymer network.
A decision analysis study of the value of a liver biopsy in nonalcoholic steatohepatitis.

Objectives: Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent clinical syndrome reflecting a mixture of pathological liver histology with the potential to progress to cryptogenic cirrhosis. Liver biopsy (LB) is the only way to determine the severity of disease. However, LB is invasive, has complications and financial costs. The aim of this study is to determine the benefits of early LB for diagnosis and early treatment. Methods: A decision tree model tracked the potential outcomes of NAFLD between an LB-directed approach vs. no initial LB. Each specific biopsy category determined subsequent care actions. The baseline probabilities were determined by literature review and expert opinion. Results: An initial LB strategy was projected to have a lower mortality compared with the no initial LB group and fewer transplant eligible patients after 5 years. If the prevalence of NAFLD is increased, the mortality increases in both the study groups. With improved efficacy of medical and/or surgical intervention, the mortality rate was decreased. Conclusion: This decision tree model provides a context for balancing the risk and benefit of LB in NAFLD. With early biopsy, and early intervention, the relative return of preventing advanced liver disease per LB was high.
Software test and analysis: Department of Defense policy directions

Summary form only given. A list is presented of policy documents which are undergoing change. Additional US Department of Defense policies affecting system and/or software acquisition that are expected to be revised in the near term include: DoD Directive 5000.1, 'Major and Non-Major Defense Acquisition Programs'; DoD Instruction 5000.2, 'Defense Acquisition Program Procedures'; and DoD 5000.3-M-3, 'Software Test and Evaluation Manual'. >
Modification of the generalized Shwartzman reaction by therapeutic agents

Abstract Various therapeutic agents known to produce vasodilation diminish the deposition of fibrin in the renal glomeruli after exposure to bacterial endotoxin. Hexamethonium was most effective, followed by cryptenamine and Mg ++ and K + ions. Interest in these agents centers around the fact that the first 3 have been used to ameliorate eclampsia with apparently beneficial results.
The Complexity of Equivalence and Containment for Free Single Variable Program Schemes

Non-containment for free single variable program schemes is shown to be NP-complete. A polynomial time algorithm for deciding equivalence of two free schemes, provided one of them has the predicates appearing in the same order in all executions, is given. However, the ordering of a free scheme is shown to lead to an exponential increase in size.
Effects of nocebo on neurogenic inflammation: Does conditioning matter?

Experimental pain can be modulated by nocebo manipulations through Pavlovian conditioning and expectancy. Neurogenic inflammation plays an important role in pain hypersensitivity and locally-exaggerated immune reactions yet its susceptibility to conditioning remains under investigated. This pilot study used a 4-day within-subject differential conditioning paradigm to investigate conditioning of capsaicin-induced neurogenic inflammation in healthy participants. On days 1–3, capsaicin solution (US) was applied to one forearm using colored filter paper as conditioned stimulus (CS+) while a neutral control solution associated with another color (CS−) was applied to the contralateral forearm. To test conditioning on day 4, the CS+ and CS− colors were applied as before using only control solution. CS applications were randomized between arms over days. Pain intensity and unpleasantness were assessed every 5 minutes for 35 minutes following CS application. Flare, a measure of neurogenic inflammation, was evaluated daily on both forearms pre- and post-application using a Laser Doppler Imager. Daily within-session flare changes were calculated for each forearm and were used to compute difference scores between forearms. Although 10 of 11 participants developed contingency awareness (expectancy), we found no conditioning of pain intensity, pain unpleasantness, or flare using a within-subject repeated measures design ( ps > . 05 ). This might be related to the USs (capsaicin-induced pain) gradually increasing and persistent effects suggesting that nocebo may not occur for pain-producing stimuli with gradual onsets.
Population structure and movements of Atlantic menhaden,Brevoortia tyrannus, as inferred from back-calculated length frequencies

As part of a continuing program begun in 1955, catches of Atlantic menhaden,Brevoortia tyrannus, were sampled for age and length at reduction plants from Florida to Massachusetts. For the years 1955–1964, lengths at the time of first annulus formation were back-calculated from age-1, −2, and −3 menhaden collected at each port, Length frequency distributions, derived from monthly and seasonal totals were plotted for the 1953–1963 year classes. Meristic data on population structure were reviewed. General conclusions drawn from these and other supporting data were (1) mixing of menhaden of all ages from all areas occurs south of Cape Hatteras, North Carolina, during the winter, (2) at the time of first annulus formation in early spring, age-1 menhaden segregate along the coast by size, which increases from south to north, (3) all menhaden do not return to the same area they occupied the previous year, (4) for normal year classes, recruitment into the fishable population may not be complete until late in the second summer of life (age-1); for exceptionally large year classes recruitment may not be complete until the beginning of the third summer (age-2), and (5) Atlantic menhaden constitute a single homogeneous population, rather than two or more subpopulations as previously hypothesized.
Coordinate-permutable cubic harmonics and their determination.

In this work, the two classes of cubic harmonics [F. C. Von der Lage and H. A. Bethe, Phys. Rev. 71, 612 (1947)] which are invariant under permutations of their Cartesian coordinates, are constructed as orthonormal polynomial functions of the latter. Each such function is conveniently expressed as a linear combination of a term of highest degree and other cubic harmonics of lesser degree. All needed expansion coefficients and normalization constants are determined explicitly in terms of the degrees of the functions that are involved.
Nanomechanical Control of Glucopyranose Rotamers

Single molecules of β-1 → 6-linked d-glucose polysaccharides, when stretched in an atomic force microscope, display a hookean-like elasticity unusual for polymers. High-level ab initio calculations and microsecond-scale molecular dynamics simulations reveal that this elasticity is governed by force-induced rotations of the exocyclic group on the glucopyranose rings from their short and less energetic gt and gg conformations to the extended and high-energy tg state. These observations indicate that a simple stretching of 1 → 6-linked glucose polysaccharides provide a unique means to control glucopyranose rotamer populations.
Laboratory Tire Groove Cracking Test

Abstract A new laboratory test for evaluating groove cracking of tire treads was developed. The tread section, including the carcass of a tire, is flexed under similar stress and temperature conditions as in actual tire service. Whole or multiple tread sections may be tested. The test is much less expensive than either road or indoor wheel tests. The test gives results that are reproducible and which are in accord with actual tire performance. In SBR/BR passenger tire tread formulations, finer carbon blacks or lower structure carbon blacks produce more groove cracking in this laboratory test; trends also observed in actual service. The inhibiting effect of antioxidants on groove cracking was demonstrated. In NR/BR treads, inversion of the structure effect was observed. Evidence has also been obtained that the test is capable of correctly predicting the effect of a tread design change upon groove cracking.
Optoelectronic closed loop auto-oscillator for fluorescence lifetime detection : a new fluorimetry technique with applications to chemical/biosensors

We present a new approach to excited state fluorescence lifetime-based measurements which is inexpensive and highly sensitive. The detection system consists of a closed-loop optoelectronic arrangement containing an intermediate frequency resonance amplifier, a fluorescence excitation light source (for example, a light emitting diode or a semiconductor laser), a fiber optic delay line, and a photodetector. The system exhibits self-oscillations in the vicinity of the frequency (Omega) approximately 1/(tau) (where (tau) is the excited state lifetime) which manifest themselves as modulation of the light. Changes in the excited state lifetime alter the phase delay of the loop, which in turn causes a frequency shift in the modulation signal. The frequency shift can be measured very precisely with a frequency counter. With appropriate averaging, this technique can yield sub-picosecond resolution of shifts in lifetime. This technique is suited for chemical/biological sensing applications, and can be easily duplicated for chemical/biological sensor arrays.
Fidelity of Eucaryotic DNA Polymerase δ Holoenzyme fromSchizosaccharomyces pombe

Abstract The fidelity of Schizosaccharomyces pombe DNA polymerase δ was measured in the presence or absence of its processivity subunits, proliferating cell nuclear antigen (PCNA) sliding clamp and replication factor C (RFC) clamp-loading complex, using a synthetic 30-mer primer/100-mer template. Synthesis by pol δ alone was distributive. Processive synthesis occurred in the presence of PCNA, RFC, and Escherichia coli single strand DNA-binding protein (SSB) and required the presence of ATP. “Passive” self-loading of PCNA onto DNA takes place in the absence of RFC, in an ATP-independent reaction, which was strongly inhibited by SSB. The nucleotide substitution error rate for pol δ holoenzyme (HE) (pol δ + PCNA + RFC) was 4.6 × 10−4 for T·G mispairs, 5.3 × 10−5 for G·G mispairs, and 4.5 × 10−6 for A·G mispairs. The T·G misincorporation frequency for pol δ without the accessory proteins was unchanged. The fidelity of pol δ HE was between 1 and 2 orders of magnitude lower than that measured for the E. coli pol III HE at the same template position. This relatively low fidelity was caused by inefficient proofreading by the S. pombepolymerase-associated proofreading exonuclease. The S. pombe 3′-exonuclease activity was also extremely inefficient in excising primer-3′-terminal mismatches in the absence of dNTP substrates and in hydrolyzing single-stranded DNA. A comparison of pol δ HE with E. coli pol IIIα HE (lacking the proofreading exonuclease subunit) showed that both holoenzymes exhibit similar error rates for each mispair.
Spectral representation of transient signals

Signal processing techniques exploiting natural and efficient representations of a class of signals with an underlying parametric model have been extensively studied and successfully applied across many disciplines. In this paper, we focus attention to the representation of one such class, i.e. transient structured signals. The class of transient signals in particular often results in computationally ill-conditioned problems which are further degraded by the presence of noise. We develop the Discrete Transient Transform, a biorthogonal transform to a basis parameterized by decay rate, along with algorithms for its implementation which mitigate these numerical issues and enable a spectral approach to parameter identification, estimation, and modeling for signals with transient behavior. The three algorithms developed have varying degrees of numerical robustness for generating the biorthogonal transient basis. Issues pertaining to transient spectral leakage and resolution are characterized and discussed in the context of an example related to Vandermonde system inversion.
Toward a Theory of Intrinsically Motivating Instruction

First, a number of previous theories of intrinsic motivation are reviewed. Then, several studies of highly motivating computer games are described. These studies focus on what makes the games fun, not on what makes them educational. Finally, with this background, a rudimentary theory of intrinsically motivating instruction is developed, based on three categories: challenge, fantasy, and curiosity. Challenge is hypothesized to depend on goals with uncertain outcomes. Several ways of making outcomes uncertain are discussed, including variable difficulty level, multiple level goals, hidden information, and randomness. Fantasy is claimed to have both cognitive and emotional advantages in designing instructional environments. A distinction is made between extrinsic fantasies that depend only weakly on the skill used in a game, and intrinsic fantasies that are intimately related to the use of the skill. Curiosity is separated into sensory and cognitive components, and it is suggested that cognitive curiosity can be aroused by making learners believe their knowledge structures are incomplete, inconsistent, or unparsimonious.
Business combinations: The next accounting albatross?

The FASB's business combinations project could become a troublesome burden. ©1999 John Wiley & Sons, Inc.
Chondrosarcoma, lupus anticoagulant and cerebral ischaemia

Chondrosarcoma is a malignant disease of cartilage. Systemic embolisation usually arises from cancerous invasion of pulmonary vessels or the left atrium but cerebral embolisation or ischaemia is rarely recognised. We report a man with left leg amputation for tibial myxoid chondrosarcoma who suffered multiple cerebral embolisms one year later. Cerebral angiography and aortogram did not reveal luminal stenosis and a cardiac survey was normal. Lupus anticoagulant (LAC) and a prolonged activated partial thromboplastin time were detected. A molecular mimicry between prothrombin and paracrine hormones may have accounted for his LAC. A procoagulant autoantibody reacting against metastatic cancer cells may contribute to cancerous thrombosis, such as in chondrosarcoma.
Surveying for “artifacts”: The susceptibility of the OCB–performance evaluation relationship to common rater, item, and measurement context effects.

Despite the increased attention paid to biases attributable to common method variance (CMV) over the past 50 years, researchers have only recently begun to systematically examine the effect of specific sources of CMV in previously published empirical studies. Our study contributes to this research by examining the extent to which common rater, item, and measurement context characteristics bias the relationships between organizational citizenship behaviors and performance evaluations using a mixed-effects analytic technique. Results from 173 correlations reported in 81 empirical studies (/V = 31,146) indicate that even after controlling for study-level factors, common rater and anchor point number similarity substantially biased the focal correlations. Indeed, these sources of CMV (a) led to estimates that were between 60% and 96% larger when comparing measures obtained from a common rater, versus different raters; (b) led to 39% larger estimates when a common source rated the scales using the same number, versus a different number, of anchor points; and (c) when taken together with other study-level predictors, accounted for over half of the between-study variance in the focal correlations. We discuss the implications for researchers and practitioners and provide recommendations for future research. [ABSTRACT FROM AUTHOR]
Influence of charge placement on the thermal and morphological properties of sulfonated segmented copolyesters

Abstract A new synthetic strategy using melt transesterification enabled selective control of ionic charge placement into the hard segment or soft segment block of segmented copolyesters. Dynamic mechanical analysis of sulfonated soft segment copolyesters revealed an increase in the low-Tg transition and rubbery plateau storage modulus as a function of sulfonation level. Sulfonated hard segment copolyesters displayed similar rubbery plateau moduli and decreasing flow temperature from 145 to 90 °C. Dynamic melt rheology and in situ, variable temperature small-angle X-ray scattering determined the non-sulfonated copolyester order-disorder transition at 150 ± 5 °C, which was ∼60 °C above the hard segment Tg. Atomic force microscopy revealed sulfonated hard segment copolyesters contained more disordered surface morphologies. Sulfonated soft segment copolyesters demonstrated increased tensile stress and improved tensile strain from 18 to 170% with increasing ion content. The enhanced mechanical performance of sulfonated soft segment was attributed to the preserved microphase-separated morphology and the presence of physical crosslinks from electrostatic interactions.
The Effect of Waiting Time and Affective Reactions on Customers' Evaluation of Service Quality in a Cafeteria

Abstract This study investigated the impact of waiting time on the evaluation of satisfaction and service quality. Research procedures included two phases. During the first phase, data on wait times, expected wait times, and satisfaction were collected by survey and observation. Surveys on service quality were distributed to customers of a university cafeteria service area in an Eastern city in the United States. The second phase investigated the relationships among waiting time, affective reactions, satisfaction, and service quality. Correlation analyses, regression, and t-tests were used to examine relationships between these variables. Results indicate that failing to meet customers' expected waiting time and reasonablewaiting time could negatively impact their satisfaction and evaluation of service quality. The study confirmed that customers' affective reaction plays a mediating role between discrepancies and satisfaction, and that waiting time is related to the reliability aspect of service quality. ...
All massive transfusion criteria are not created equal: defining the predictive value of individual transfusion triggers to better determine who benefits from blood.

Background:As familiarity with military massive transfusion (MT) triggers has increased, there is a growing interest in applying these in the civilian population to initiate MT protocols (MTP) earlier. We hypothesize that these triggers do not have equal predictability for MT and understanding the c
Length-based encoding of binary data in DNA

We developed a system to encode digital information in DNA polymers based on the partial restriction digest (PRD). Our encoding method relies on the length of the fragments obtained by the PRD rather than the actual content of the nucleotide sequence, thus eliminating the need for expensive sequencing machinery. In this letter, we report on the encoding of 12 bits of data in a DNA fragment of 110 nucleotides and the process of recovering the data.
Study of penicillin antibodies by fluorescence polarization and immunodiffusion.

1. Antibodies prepared in the rabbit to penicilloyl-rabbit serum albumin or to penicilloyl-bovine serum albumin were demonstrated by immunodiffusion and absorption methods to be apparently directed exclusively against the penicilloyl moiety. The antibodies could precipitate heavily substituted penicilloyl polylysine, as well as each other, with "reactions of identity". All could mutually deplete detectable antibodies by cross-absorption. 2. Small haptens containing both fluorescein and the penicilloyl group were synthesized. They were also capable of completely absorbing the antipenicilloyl antibodies from rabbit antiserum, as evidenced by immunodiffusion tests. The haptens were used in fluorescence polarization tests with gamma globulin from normal and immunized rabbits, and from normal and allergic humans. The rabbit antipenicilloyl gamma globulins in concentrations as low as 5 to 10 µg of protein/ml could significantly increase the polarization of the haptens. Normal gamma globulin had no effect at the highest concentrations tested, 1200 µg/ml. In all tests, rabbit and human antibody reacted similarly. 3. Fluorescence polarization titration curves for both human and rabbit antipenicilloyl gamma globulins were analyzed by computer and the antibody concentrations, avidities, and heterogeneity constants were determined. For the human antibody, the latter two values were 3.0 x 107 M–1 and 0.78, while for the rabbit, they were 8.7 x 106 M–1 and 0.71. The data were employed to estimate the limit of sensitivity of fluorescence polarization for detecting antipenicilloyl antibodies. Under the conditions employed, this value was roughly 0.4 µg antibody/ml. 4. When the whole rabbit sera were tested for penicilloyl antibodies by fluorescence polarization, both normal (preimmune) and immune sera revealed striking and equivalent increases in polarization with the penicilloyl haptens. This non-specific binding was shown to be due at least in part to serum albumin. Indications were obtained that it might be significantly reduced by increasing the pH or the salt concentration of the medium, or by addition of certain anions.
Impacted teeth in denture-bearing areas: A potential source of problems

Abstract Impacted teeth, even if deeply located in bone, are a potential source of problems if left in denture-bearing areas. A case is described wherein an impacted lower premolar was exposed to the oral environment because of advanced resorption of the alveolar ridge and became infected. Pathologic fracture of the mandible would probably have occurred if the tooth had not been removed. However, the possibility of fracture also existed at the time the tooth was extracted. Atraumatic removal was achieved with a high-speed air turbine.
Operative and Immediate Postoperative Outcomes of Using a Latham-Type Dentomaxillary Appliance in Patients With Unilateral Complete Cleft Lip and Palate.

Objective: The objective of this study is to examine the operative and immediate postoperative effects of the use of a dentomaxillary appliance (DMA). Design: Retrospective chart review of 40 treated patients with unilateral complete cleft lip and palate who had a comprehensive set of pre-, peri-, and postoperative records. Setting: Boston Children's Hospital. Patients: Forty treated patients with unilateral complete cleft lip and palate. Interventions: Use of DMA. Main Outcome Measures: Outcome variables of interest included cleft lip width reduction following use of DMA and odds of having primary gingivoperiostetoplasty (GPP). Results: The study sample included 40 subjects (31 boys and 9 girls). The average age at the time of DMA insertion was 11 weeks. The average width of the alveolar cleft prior to DMA insertion was 10.77 mm. The mean cleft width reduction was 8.66 mm. Each 1-mm increase in pre-DMA cleft width was associated with a 0.631-mm reduction in cleft width (P < .001). Thirty-three patients (...
The Biology and Natural History of Aphaenogaster rudis

Workers from the genus Aphaenogaster are among the most abundant ants in the hardwood forests of eastern North America. The biology of these so-called rudis-group ant species, including details about their sociometry, productivity, natural history, and behavior, are synthesized here using published and newly collected data. The latter was collected, in part, using an artificial field nest, and its construction and use are explained. Ants of the rudis group occur in high densities in forest habitats (0.5–1.3 nests m2), have moderate sized colonies (population means from 266 to 613 workers per nest), and are keystone seed dispersers. Many aspects of their life history and behavior follow an annual cycle that tracks seasonal changes. These include foraging, reproduction, the production of new workers and nest migrations. This synthesis highlights what is known about these ants and reveals gaps in our knowledge that require further study.
A New MANET Accessing Internet Method Based on Complex Network

Considering the complex network characteristics of mobile ad hoc network, a new MANET accessing Internet model was proposed. In this model, transmit power was adjusted by residual energy of the node, and added long-range edge in network to make MANET with more obvious small world characteristics. On this basis, the paper proposed a gateway programming model, which introduced a decision node to harmonize the utilization of gateways and routes. The model, as the basis of the gateway configuration, optimized the placement of the gateway. The simulation results indicate that the performance of delay, overhead and throughput has promoted after the model was introduced, which validates the validity of the model.
The significance of difference between means without reference to the frequency distribution function.

Most existing tests for significance of difference between means require specific assumptions concerning the distribution function in the parent population. The need for a test which can be applied without making any such assumption is stressed. Such a statistical test is derived. The application of the test involves converting scores to rank orders. The exact probabilities may then be calculated for specified differences between samples by means of which the null hypothesis may be tested. The application of the test is simple and requires a minimum of calculation. The test loses in precision because of the conversion to rank orders but gains in generality since it may be safely used with any kind of distribution.
Calculated minimum energy conformations of nonactin.

Nonactin is a cyclic actinomycete metabolite which has been implicated as an ion carrier in the passive transport of potassium across certain biological membranes. In order to discover the conformations of the molecule which are involved in its biochemical function, computer calculations were initiated to derive the energetically favored conformations of the nonactin ring. By assuming that all the relevant three-dimensional conformations of nonactin have the same symmetry property as that suggested by the chemical structure of the molecule (S4) it was possible to generate a representative sample of all sterically allowed conformations of nonactin. The energies of these conformations were calculated by taking into account the nonbonded interactions among the 116 atoms of the molecule and the torsional potential energy of the 20 rotatable backbone bonds of the ring. The initial results reported in this paper indicate that even in the absence of potassium ion the nonactin ring folds into the same compact tennis-ball seam-like conformation that was found by an X-ray crystallographic investigation of the nonactin/KNCS complex.
Synthesis, Properties, and Tunable Supramolecular Architecture of Regioregular Poly(3-alkylthiophene)s with Alternating Alkyl and Semifluoroalkyl Substituents

A series of regioregular poly(3-alkylthiophene)s, Rg(Th-m,n/p) (m = 5, 8, 11; n = 4; p = 4, 8, 12), with alternating alkyl and semifluoroalkyl substituents has been synthesized by the GRIM polymeri...
Parameter estimation for a Volterra integro-differential equation

Abstract We consider identification of parameters in a Volterra integro-differential system with a weakly singular kernel. Such kernels arise in fractional derivative damping models of viscoelastic materials. A quasilinearization method is used to identify damping parameters in the system. Numerical methods are used which are adapted to weakly singular systems whose kernels are not continuous at the origin.
The Solar Wind and Interplanetary Field during Very Low Amplitude Sunspot Cycles

Cosmogenic isotope records indicate that a solar-cycle modulation persists through extended periods of very low sunspot activity. One immediate implication is that the photospheric field during such grand minima did not consist entirely of ephemeral regions, which produce a negligible amount of open magnetic flux, but continued to have a large-scale component originating from active regions. Present-day solar and heliospheric observations show that the solar wind mass flux and proton density at the coronal base scale almost linearly with the footpoint field strength, whereas the wind speed at Earth is uncorrelated with the latter. Thus a factor of ~4-7 reduction in the total open flux, as deduced from reconstructions of the interplanetary magnetic field (IMF) during the Maunder Minimum, would lead to a similar decrease in the solar wind densities, while leaving the wind speeds largely unchanged. We also demonstrate that a decrease in the strengths of the largest active regions during grand minima will reduce the amplitude of the Sun's equatorial dipole relative to the axial component, causing the IMF strength to peak near sunspot minimum rather than near sunspot maximum, a result that is consistent with the phase shift observed in the 10Be record during the Maunder Minimum. Finally, we discuss the origin of the 5 yr periodicity sometimes present in the cosmogenic isotope data during low and medium amplitude cycles.
Effect of CO2 on the stability of strontium doped lanthanum manganite cathode

Abstract Strontium doped lanthanum manganite cathode stability in 0–10% carbon dioxide containing air has been studied in the temperature range of 1023–1123 K with cathodic biases of 0 V and 0.5 V. The current density of the LSM cathode remains stable after an initial decrease. Surface analyses of the pre-test and post-test LSM cathodes using Auger electron spectroscopy (AES) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) techniques suggest that the formation of SrCO 3 at the LSM surface leads to initial performance degradation. Our observations also indicate that CO 2 does not affect the current density after an initial LSM activation in air. Overall, the LSM performance degradation in CO 2 -containing air is less severe than in humidified air.
Watching My Weight: Self-Weighing, Body Surveillance, and Body Dissatisfaction

Understanding of the benefits of self-weighing are currently mixed, particularly with respect to women’s psychological health. Applying Objectification theory (Fredrickson and Roberts 1997), we explored the role of body surveillance as a mechanism in the link between self-weighing, a common weight management technique, and body dissatisfaction. The study was cross-sectional and the sample included primarily Caucasian, US college students from the Northeast (N = 145). Participants completed measures of self-weighing, body surveillance, and body dissatisfaction. We predicted that body surveillance would mediate the positive relation between self-weighing and body dissatisfaction. Results supported our prediction; however additional work is necessary to clarify the potential negative effects of self-weighing on women’s body image.
Mechanical behavior of austenitic stainless steel weld metals with microfissures

Abstract Mechanical behavior of all-weld-metal specimens of 308L and 316L weld with and without microfissures was evaluated by standard and pre-strain tensile testing. The test results show a similar yield strength, and a small difference on tensile strength for fissured and fissure-free 316L weld deposits. There is virtually no effect on yield and tensile strength for 308L. Microfissures in these weld metals negatively affect ductility of 316L and 308L.
A comparison of quantitative EEG frequency analysis and conventional EEG in patients with focal brain lesions

Abstract The sensitivity and specificity of quantified EEG frequency analysis (EEGFA) were assessed in a group of patients with CT or MRI verified unilateral cerebral lesions and compared with the results of conventional EEG interpretations. Digital EEG recordings were obtained in 25 patients and 25 normal control subjects during performance of an alerting task. Recording artifacts were carefully eliminated. The results of EEGFA were then statistically compared with those of 75 additional normal subjects in the same age range. Complete conventional EEGs were blindly interpreted by two independent electroencephalographers using a structured reporting procedure. We observed similar overall sensitivities for the two methods. Optimal yeild for EEGFA was associated with the use of longer edited EEG lengths, longitudinal bipolar montage, and normative data bases on total EEG power. In those recordings with normal or mildly abnormal EEG backgrounds the two techniques were to an extent complimentary, each detecting abnormalities missed by the other. In such circumstances EEGFA may be useful as an extension of conventional EEG interpretation.
Insect Herbivore Responses to Management Practices in Conifer Forests in North America

ABSTRACT Pine-dominated forests in southeastern North America and at low-to-mid elevations in western North America historically were characterized by frequent, low-intensity fire that maintained wide spacing of site-adapted tree species, conditions that optimized biochemical defenses of trees and dispersal distances of herbivorous insects. Mixed conifer forests at higher elevations were wetter, denser, and characterized by infrequent stand-replacing fire and relatively isolated insect outbreaks. Increased density and altered tree species composition in managed forests have increased forest vulnerability to extensive outbreaks of bark beetles and defoliators. Herbivore-generated tree mortality and litter accumulation increase the likelihood of catastrophic fire. Management practices that produce an appropriate mixture of site-adapted tree species and wide host spacing are recommended to minimize the negative effects of herbivorous insects and fire. However, the creation of stumps, as a result of mechanica...
Diameter series of lattice covering simplices

We develop an interesting relationship between finite sets in a lattice and the minimal density of simplex coverings of n-space.
Comparison of Three Methods and Two Cooking Times in the Determination of Total Dietary Fiber Content of Dried Legumes

Abstract Freeze-dried samples of a variety of dried legumes cooked according to package instructions were analyzed for their total dietary fiber using a recently published method (I) which utilizes porcine pancreatic enzymes. The values from the latest study compared those obtained previously using simplified single enzyme method (II) and an AOAC/MES-Tris buffer method 991.43 (III). Total dietary fiber content varied form 17% (g/100 g dry weight) for chickpeas to 30% for kidney beans as determined by methods (I) and (II), and 30 to 58% with the same legumes using method (III). Comparisons were also made using (II) and (III) on the effect of cooking time on the total dietary fiber values for 10 legumes. Greater variations were found in fiber content between cooking times with method (III). Variations between brands of the same legumes were also more pronounced with the AOAC method. This may be accounted for by the day to day variability of the method when used on samples containing high starch.
Characterizing the protonation states of the catalytic residues in apo and substrate-bound human T-cell leukemia virus type 1 protease

Display Omitted Protonation states of the catalytic residues in HTLV-1 protease were investigated.In apo HTLV-1 protease, the two catalytic residues are both unprotonated.In HTLV-1 protease-substrate complex, Asp32 is protonated, Asp32' is unprotonated.Substrate binding favors a protonated Asp32 over protonated Asp32' by 2.8kcal/mol.The HTLV-1 protease-substrate complex structure was analyzed in detail. Human T-cell leukemia virus type 1 (HTLV-1) protease is an attractive target when developing inhibitors to treat HTLV-1 associated diseases. To study the catalytic mechanism and design novel HTLV-1 protease inhibitors, the protonation states of the two catalytic aspartic acid residues must be determined. Free energy simulations have been conducted to study the proton transfer reaction between the catalytic residues of HTLV-1 protease using a combined quantum mechanical and molecular mechanical (QM/MM) molecular dynamics simulation. The free energy profiles for the reaction in the apo-enzyme and in an enzyme - substrate complex have been obtained. In the apo-enzyme, the two catalytic residues are chemically equivalent and are expected to be both unprotonated. Upon substrate binding, the catalytic residues of HTLV-1 protease evolve to a singly protonated state, in which the OD1 of Asp32 is protonated and forms a hydrogen bond with the OD1 of Asp32', which is unprotonated. The HTLV-1 protease-substrate complex structure obtained from this simulation can serve as the Michaelis complex structure for further mechanistic studies of HTLV-1 protease while providing a receptor structure with the correct protonation states for the active site residues toward the design of novel HTLV-1 protease inhibitors through virtual screening.
Structures of Thiolate- and Carboxylate-Ligated Ferric H93G Myoglobin: Models for Cytochrome P450 and for Oxyanion-Bound Heme Proteins†,‡

Crystal structures of the ferric H93G myoglobin (Mb) cavity mutant containing either an anionic proximal thiolate sulfur donor or a carboxylate oxygen donor ligand are reported at 1.7 and 1.4 A resolution, respectively. The crystal structure and magnetic circular dichroism spectra of the H93G Mb β-mercaptoethanol (BME) thiolate adduct reveal a high-spin, five-coordinate complex. Furthermore, the bound BME appears to have an intramolecular hydrogen bond involving the alcohol proton and the ligated thiolate sulfur, mimicking one of the three proximal N−H···S hydrogen bonds in cytochrome P450. The Fe is displaced from the porphyrin plane by 0.5 A and forms a 2.41 A Fe−S bond. The Fe3+−S−C angle is 111°, indicative of a covalent Fe−S bond with sp3-hybridized sulfur. Therefore, the H93G Mb·BME complex provides an excellent protein-derived structural model for high-spin ferric P450. In particular, the Fe−S bond in high-spin ferric P450-CAM has essentially the same geometry despite the constraints imposed by cov...
Some Problems and Priorities in Health-Care Technology

What should be the priorities for health-care technology a decade from now? Given enormous population expansion and pressure, given increased concern with health care, given diminished efficiency of care owing to these overpressures, and given an enticing banquet of sophisticated technology-what should we do now to shape the future, explicitly and deliberately, so that ten years from now we will not regret lost opportunities?
Using vapor phase tomography to measure the spatial distribution of vapor concentrations and flux for vadose-zone VOC sources

A test was conducted at a chlorinated-solvent contaminated site in Tucson, AZ, to evaluate the effectiveness of vapor-phase tomography (VPT) for characterizing the distribution of volatile organic contaminants (VOC) in the vadose zone. A soil vapor extraction (SVE) system has been in operation at the site since 2007. Vapor concentration and vacuum pressure were measured at four different depths in each of the four monitoring wells surrounding the extraction well. The test provided a 3D characterization of local vapor concentrations under induced-gradient conditions. Permeability data obtained from analysis of borehole logs were used along with pressure and the vapor-concentration data to determine VOC mass flux within the test domain. A region of higher mass flux was identified in the deepest interval of the S-SW section of the domain, indicating the possible location of a zone with greater contaminant mass. These results are consistent with the TCE-concentration distribution obtained from sediment coring conducted at the site. In contrast, the results of a standard soil gas survey did not indicate the presence of a zone with greater contaminant mass. These results indicate that the VPT test provided a robust characterization of VOC concentration and flux distribution at the site.
Children's response to sales promotions and their impact on purchase behavior

Abstract Despite the growth in children's purchasing power, surprisingly little is known about how children respond to sales promotions. We conduct two experiments to address this issue. Study 1 shows that elementary-aged (second and fifth grade) children's purchase decisions are influenced by the presence of sales. Study 2 demonstrates that both age groups favor conceptually easier promotions, even when the sale is inferior. Additionally, we find that children have difficulty applying mathematical concepts to sales promotions, regardless of classroom mastery of the associated operations. Together, these results indicate that elementary-aged children routinely incorporate sales into purchase decisions, sometimes with suboptimal results.