cssi/SciSciGPT-SciSciNet huggingface dataset:
Nonlocal Tug-of-War and the Infinity Fractional Laplacian

Motivated by the “tug-of-war” game studied by Peres et al. in 2009, we consider a nonlocal version of the game that goes as follows: at every step two players pick, respectively, a direction and then, instead of flipping a coin in order to decide which direction to choose and then moving a fixed amount e > 0 (as is done in the classical case), it is an s-stable Levy process that chooses at the same time both the direction and the distance to travel. Starting from this game, we heuristically derive a deterministic nonlocal integrodifferential equation that we call the “infinity fractional Laplacian.” We study existence, uniqueness, and regularity, both for the Dirichlet problem and for a double-obstacle problem, both problems having a natural interpretation as tug-of-war games. © 2011 Wiley Periodicals, Inc.
ULTRAVIOLET INACTIVATION OF THE MIDI VARIANT OF Qβ RNA: UV-INDUCED ‘KINETIC BARRIERS’ TO REPLICATION AT TWO TEMPERATURES

— MDV-1 RNA is a small variant of bacteriophage Qβ, and is an active template in replication reactions catalyzed by Qβ replicase. The predominant lesion formed when MDV-1 is irradiated with 254 nm light with a dose of 2500 Jm-2 is uridine hydrate, which is chemically closely related to the major thymidine products formed in DNA by ionizing radiation. We have found that the replication of irradiated MDV-1 RNA is inhibited at 37°C as well as 12°C. However, while replication appears to be blocked at the sites of photolesions at 12°C, Qβ replicase ‘pauses’ at the lesions before continuing elongation at 37°C. This effect is not caused by reversion of the photoproducts to parent material at the higher temperature. ‘Pauses’ (caused by ‘kinetic modulators’) during the synthesis of nucleic acids from unirradiated templates have been reported to occur in a number of systems and may play a role in the regulation of transcription and replication. Our results suggest that one consequence of radiation damage to nucleic acid bases may be the introduction of lesions which mimic such modulators, leading to aberrations in the regulation of nucleic acid synthesis.
The spatial averaging theorem revisited

Abstract The derivation of the spatial averaging theorem is presented directly rather than as an appendage of the general transport theorem. This is done in order to clarify in what sense the theorem is an “approximation”.
Biochemical mediators of the effects of mechanical forces and electric currents on mineralized tissues.

Cyclic nucleotides (cAMP and cGMP) and prostaglandin E (PGE) have been implicated as possible mediators of the effects of external stimuli on bone cells. The objective of this study was to determine changes in relative levels of these substances in mineralized tissue cells in response to mechanical and electrical stimuli, by the use of a combined immunohistochemical-microphotometric procedure. Canine teeth of eight 10–12 month-old female cats were tipped distally with 80 g force for either 1 h or 14 days. After 1 h, a slight elevation of staining intensity in alveolar bone osteoblasts and periodontal ligament (PDL) cells was observed at sites of tension and compression. After 14 days of treatment, this effect was markedly increased. Fifteen female cats, 10–12 months old, received electric stimulation (20 µ amperes d.c.) to the gingiva of 1 maxillary canine for 1, 5, 15, 30, or 60 min. At the cathode, significant increases of staining intensity in periosteal osteoblasts for cAMP, cGMP, and PGE were found at 15 and 60 min. At the anode, a significant rise in the staining intensity of these cells for PGE was seen at 15 min; at 60 min, cGMP and PGE, but not cAMP, were elevated. These results demonstrate the usefulness of the immunohistochemical technique in detecting relative changes in mineralized tissue cell content of cyclic nucleotides and prostaglandins in response to local application of physical stimuli of short and long duration.
Dispersion characteristics of a nonlinear elastic metamaterial

We study wave dispersion in a one-dimensional nonlinear elastic metamaterial consisting of a thin rod with periodically attached local resonators. Our model is based on an exact finite-strain dispersion relation for a homogeneous solid, utilized in conjunction with the standard transfer matrix method for a periodic medium. The nonlinearity considered stems from large elastic deformation in the thin rod, whereas the metamaterial behavior is associated with the dynamics of the local resonators. We derive an approximate dispersion relation for this system and provide an analytical prediction of band-gap characteristics. The results demonstrate the effect of the nonlinearity on the characteristics of the band structure, including the size, location, and character of the band gaps. For example, large deformation alone may cause a pair of isolated Bragg-scattering and local-resonance band gaps to coalesce. We show that for a wave amplitude on the order of one-eighth of the unit cell size, the effect of the nonlinearity in the structure considered is no longer negligible when the unit-cell size is one-fourteenth of the wavelength or larger.
Views and over-views on/of U.S. government documents

Abstract In this periodic review of government publications, the judgments expressed are those of the reviewer, Dr. Frederic O'Hara, Professor of Library Science, Graduate Library School, Long Island University, Greenvale, New York 11548. Unless otherwise indicated, all items may be purchased from the Superintendent of Documents, Government Printing Office, Washington, D.C., 20402. Dr. O'Hara does not handle the distribution of any documents.
Effect of external beam irradiation on neointimal hyperplasia after experimental coronary artery injury.

Abstract Human coronary artery restenosis after percutaneous revascularization is a response to mechanical injury. Smooth muscle cell proliferation is a major component of restenosis, resulting in obstructive neointimal hyperplasia. Because ionizing radiation inhibits cellular proliferation, this study tested in a porcine coronary injury model the hypothesis that the hyperplastic response to coronary artery injury would be attenuated by X-irradiation. Deep arterial injury was produced in 37 porcine left anterior descending coronary artery segments with overexpanded, percutaneously delivered tantalum wire coils. Three groups of pigs were irradiated with 300-kV X-rays after coil injury: Group I (n = 10), 400 cGy at 1 day; Group II (n = 10), 400 cGy at 1 day and 400 cGy at 4 days and Group III (n = 9), 800 cGy at 1 day. Eight pigs in the control group underwent identical injury but received no radiation. Treatment efficacy was histologically assessed by measuring neointimal thickness and percent area stenosis. Mean neointimal thickness in all irradiated groups was significantly higher than in the control groups and thickness was proportional to X-ray dose. X-irradiation delivered at these doses and times did not inhibit proliferative neointima. Rather, it accentuated the neointimal response to acute arterial injury and may have potentiated that injury.
Use of monkeys to demonstrate allergic cross-reactions among the euphorbiaceae: Ricinus communis, poinsettia pulcherrima, euphorbia esula

Abstract Individuals who are sensitized by or allergic to one species of Euphorbiaceae may be allergic to other species also. Guinea pigs passively sensitized with sera from rabbits that had been sensitized to Ricinus communis (castor bean) exhibited passive cutaneous anaphylaxis with extravasation of Evans blue dye when challenged with antigens extracted from the blossoms and seeds of Poinsettia pulcherrima , or Euphorbia esula. Macaca irus monkeys passively sensitized with blood sera from castor bean-allergic human beings exhibited PCA reactions when challenged with blossom antigens from either of these euphorbias.
RELATIONSHIP OF MYOFIBRIL FRAGMENTATION INDEX TO MEASURES OF BEEFSTEAK TENDERNESS

Samples were removed from 6 veal, 35 A-maturity and 12 C-maturity bovine longissimus (L) muscles at 1 and 7 days postmortem. Myofibril fragmentation index (MFI), Warner-Bratzler (W-B) shear-force, sensory panel evaluation and sodium dodecyl sulfate (SDS) polyacrylamide gels of myofibrils were determined on muscle samples and steaks. Correlation coefficients between MFI and W-B shear-force were -0.95, -0.73 and -0.65 and, between MFI and sensory tenderness, were 0.97, 0.75 and 0.72 for steaks postmortem aged for 7 days at 2°C from veal, A-maturity and C-maturity carcasses, respectively. SDS-polyacrylamide gels showed that the intensity of the 30,000-dalton component corresponded to the tenderness level of the steaks. These results demonstrate that MFI accounts for about 50% of the variation in tenderness and that myofibril fragmentation and the intensity of the 30,000-dalton component offer potential usefulness as indices of tenderness.
Shattering the myth of the resonantly photo-pumped neon-like titanium laser

We will present results which show lasing on the 3p yields 3s (J equals 0 yields 1) transition in neon-like chromium (Z equals 24), iron (Z equals 24), iron (Z equals 26), and nickel (Z equals 28) at 285, 255, and 231 angstroms respectively. This destroys the myth of titanium being unique and makes highly unlikely that the previously mentioned photo-pumping mechanism is playing a significant role in the titanium laser. The chromium, iron, and nickel experiments all require a prepulse in order to lase and our calculations suggest that the prepulse is an exciting new way to create a uniform low density plasma when illuminating a thick slab target. This allows the proper conditions for gain and laser propagation for low Z neon-like ions and may also be applicable to other systems such as low Z nickel-like ions. We also will present experiments done on other low-Z materials and offer an explanation as to how the hyperfine effect is destroying the gain of neon-like ions with odd Z.
Elimination of isoproterenol-induced prolinerich protein biosynthesis in rat salivary glands after adult thyroidectomy

Abstract Surgical thyroidectomy of adult rats resulted in a gradual decrease in β-adrenergic receptor density on the cell surface of parotid and submandibular glands. The decrease in β-adrenergic receptors was 29 and 50% by 2 and 4 weeks, respectively, for the parotid gland. In the submandibular gland, a decrease of 50% of the total β-receptor density was evident after 2 weeks. After 4 weeks no further decrease in β-adrenergic receptor was observed. Subsequent challenge of the salivary glands with chronic treatment of isoproterenol (β-adrenergic receptor agonist) failed to induce proline-rich protein and glycoprotein biosynthesis in the submandibular gland 2 weeks after thyroidectomy, whereas the parotid gland showed induced proline-rich protein but not the glycoprotein synthesis. By 4 weeks the parotid gland did not show the induced synthesis of the glycoprotein or proline-rich proteins. The inability to induce protein synthesis was reflected by decreased cAMP accumulation in both glands after injection with isoproterenol. Partial reversal of these effects on protein synthesis and cAMP accumulation was obtained by triiodothyronine treatment of thyroidectomized rats.
An activity theoretic model for information quality change

To manage information quality (IQ) effectively, one needs to know how IQ changes over time, what causes it to change, and whether the changes can be predicted. In this paper we analyze the structure of IQ change in Wikipedia, an open, collaborative general encyclopedia. We found several patterns in Wikipedia’s IQ process trajectories and linked them to article types. Drawing on the results of our analysis, we develop a general model of IQ change that can be used for reasoning about IQ dynamics in many different settings, including traditional databases and information repositories.
Neoplastic progression in crown gall in tobacco without elevated auxin levels.

We have isolated two stable variants from a crown-gall teratoma tissue of tobacco (Nicotiana tabacum L.) transformed by Agrobacterium tumefaciens strain A66, a mutant of the virulent A6 strain containing an insertion sequence in the tumor-inducing (Ti) plasmid at the locus coding for auxin biosynthesis. Normally tobacco cells transformed by strain A66 spontaneously form shoots in culture and will not grow on hormone-free medium unless shoots develop. The variant tissue lines, isolated from the teratoma tissue after prolonged culture in the dark, grew as friable and unorganized tissues on hormone-free growth medium. Growth of the variants was more sensitive to auxin feeding than growth of the parental teratoma line, and the auxin dose-response curves of the variant lines were similar to those obtained with A6-transformed tobacco cells. Southern blot analysis of DNA from the parental teratoma line and one of the variants showed no differences in copy number or organization of the oncogenic DNA sequence (T-DNA) transferred from the bacterium, indicating that the variant phenotype did not result from reversion of the A66 mutation. Radio-immunoassay analysis showed similar levels of indole-3-acetic acid (IAA) in the variants and parental teratoma line (3–50 and 38–42 pmol·(gFW)-1, respectively), whereas an A6-transformed cell line contained much higher IAA levels (150–1200 pmol·(g FW)-1). Low levels of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid in the variants and the parental teratoma line ( 100 nmol· (g FW)-1) provided additional, indirect evidence for low auxin levels in the variant lines. These results indicate that crown-gall teratoma tissues of tobacco may switch to the unorganized, auxin-sensitive phenotype without an increase in auxin content.
Case Against Angioplasty and Stenting of Atherosclerotic Renal Artery Stenosis

Atherosclerotic renal artery stenosis (RAS) is a relatively common problem, estimated to affect between 1% and 5% of patients with hypertension.1,2 Given the high prevalence of hypertension, it follows that there are from 2 million to 4 million individuals with RAS in the United States alone. A challenging feature of the disease is the high incidence of adverse cardiovascular events in affected individuals compared with those with normal renal arteries, which also presents a potential opportunity. On the one hand, there may be such a large burden of atherosclerotic disease by the time patients present that it is too late for an intervention in a single vascular bed to significantly alter outcomes. On the other hand, it is possible that an effective intervention might reduce adverse events, which has led some physicians to take an aggressive approach to diagnosing and correcting RAS. Response by Cooper and Murphy p 276 In fact, although individual patients sometimes appear to benefit, whether renal artery revascularization reduces adverse cardiovascular and renal events is currently unknown. Nevertheless, stenting of RAS is performed commonly, with ≈40 000 procedures reported each year in the United States alone. Most often, revascularization is undertaken in 1 of 3 clinical settings and with a specific goal: (1) in patients with resistant hypertension to achieve better blood pressure control, (2) in patients with renal insufficiency to prevent progression to end-stage renal failure, or (3) in patients with congestive heart failure to prevent recurrent exacerbations requiring hospitalization. The present article discusses these “indications” and reviews the data suggesting that revascularization is no better than medical therapy in these settings. Furthermore, just as interventional techniques progress, advances in medical therapy have significantly improved outcomes for patients treated conservatively, making it less likely that revascularization will provide significant benefits to future patients. There …
Further characterization of a clinically relevant model of melanoma metastasis and an effective vaccine.

A major problem in evaluating the effectiveness of tumor cell vaccination and other biological therapies is the variability of experimental models. In this study we have further developed and characterized a model for metastatic melanoma that approximates the major clinical stages of metastatic dissemination: stage I-growth of the primary (local) tumor, stage II-dissemination to regional lymph nodes, and stage III-metastasis to distant organs (lungs). C57BL/6 mice were challenged subcutaneously with B16 F10 murine melanoma cells in the midtail, and within 3 weeks 100% of the mice had local tumors growing in their tails. By 5–7 weeks after challenge, most of the mice had developed metastases to the inguinal lymph nodes and subsequently had metastatic colonies in the lungs and in the bone marrow. Preimmunization of mice with a formalinized extracellular antigen vaccine, derived from B16F10 melanoma cells, provided partial inhibition of the growth of the primary melanoma tumors, as well as reducing the number of metastases to the regional (inguinal) lymph nodes and lungs along with concomitantly increasing survival time. This model for melanoma metastasis provides a reasonable and reproducible test system for the study of anti-melanoma immunity and the different cellular and humoral mechanisms involved.
THE PREPARATION OF AMINO ACID-TRANSFER RIBONUCLEIC ACID FROM ESCHERICHIA COLI BY DIRECT PHENOL EXTRACTION OF INTACT CELLS.

Abstract A method for the preparation of transfer-RNA from Escherichia coli by direct phenol extraction of intact cells is described. The transfer-RNA preparation contains only traces of DNA and protein but polysaccharide contamination ranges from 3 to 11% of the transfer-RNA present. The success of the method depends upon harvesting the cells for extraction while they are in the logarithmic phase of growth. Sedimentation analyses of extracts from log phase cells show very little contamination with RNA of higher molecular weight than the transfer-RNA while analyses of extracts from stationary phase cells show gross contamination with high molecular weight RNA.
Is Hierarchical Governance in Decline? Evidence from Empirical Research

The growing acceptance of ‘‘governance’’ as an organizing concept for public management reform reflects a widespread, though not universal, belief that the focus of administrative practice is shifting from hierarchical government toward greater reliance on horizontal, hybridized, and associational forms of governance. Recent arguments to this effect, however, make limited recourse to the body of empirical evidence that might shed light on the actual extent of this transformation. In this article we report on our review of over eight hundred individual research studies in order to assess what we know about governance based on available empirical evidence across a range of disciplines and substantive fields. We find that hierarchical investigations of the nature and consequences of governmental action predominate in the literature. We supplement this primary finding with additional analyses of research on performance and on public management. We then discuss possible reasons for the observed hierarchical orientation of research. While we cannot rule out the possibility that our findings reflect researchers’ biases rather than actual governance, we infer that the shifts away from hierarchical government toward horizontal governing reflect instead a gradual addition of new administrative forms that facilitate governance within a system of constitutional authority that is necessarily hierarchical. In conclusion, we propose additional research that might confirm or refute this inference and that could fill the gaps of our understanding of public governance.
Distinctive human social motivations in a game-theoretic framework

I discuss implications of Tomasello et al's hypothesis that humans exhibit distinctive collective intentionality for game-theoretic approaches to modeling human evolution. Representing the hypothesis game-theoretically forces a question about whether it implies only distinctively human motivations or both distinctive motivations and distinctive cognitive capacities for representation of intentions. I also note that the hypothesis explains uniquely human ideological conflict and invites game-theoretic modeling of this.
Toward synergistic engineering of computer systems

Our objective is to provide a forum for sharing problems, experiences, and solutions that can help establish bridges among hardware engineers, software engineers, systems engineers, and project managers. We seek to publicize innovative solutions and engineering methodologies that address: complexity, model-based engineering (as exemplified by hardware/software codesign), and process management. We believe these three areas are critical to advancing the successful, integrated engineering of computer-based systems.
Mutation-absorption model of the enzyme

Abstract Gradual changes in function of proteins in response to single changes in primary structure are often observed to occur and are a necessary condition for evolution by variation and natural selection at the protein level. A probabilistic (entropy theory) analysis of the effect of changes in primary structure on three-dimensional shape and function shows that such gradualism is based on the presence of a control system in the molecule involving a definite general form of structure-function degeneracy. The assumptions of the analysis are that primary structure determines tertiary structure (or a thermal distribution of tertiary configurations and allosteric forms), tertiary structure determines function (characterized by rate and other parameters), and that certain features of tertiary structure may be specialized for particular functions. The main conclusion is that embodied in the molecule is a subsystem which serves as a buffer, absorbing mutation or other forms of genetic variation and expressing these as graceful variations in features of the shape critical for function. This buffer system may be realized by numerical redundancy of amino acids or other mechanisms which increase the redundancy of weak interactions responsible for folding, utilization of amino acids having a greater number of analogs with redundant features, or local and global structural formats which allow for more effective utilization of redundancy. The mutation-absorption model has implications for the interpretation of structure-function relations in biology, the topology of the adaptive landscape, the interpretation of isoenzymes and allozymes, the relationship between selection and neutralism in evolution, and the relation between the complexity of and energy required by biological systems and the effectiveness of evolutionary optimization.
Tandem mass spectrometry of peptides: sequence information based on neutral losses. I: Isomeric dipeptides

The neutral losses arising on the collisionally activated dissociation (CAD) of protonated dipeptides (MH + ) are reionized by collision and detected in neutral fragment-reionization (N f R) mass spectra. For the dipeptides investigated, which encompass Ala-Gly/Gly-Ala, Asp-Gly/Gly-Asp, Phe-Gly/Gly-Phe and Trp-Ala/Ala-Trp, the N f R spectra of each pair of isomers are distinct and permit the identification of the correct C-terminal amino acid. The precise structure of this amino acid is elucidated by comparison of the N f R spectra with reference collision-induced dissociative ionization (CIDI) mass spectra of authentic Gly, Ala, Asp, Phe and Trp, acquired from beams of these amino acids formed by dissociation of their proton-bound dimers
A kinetic investigation of the addition of diazomethane to styrenes. Role of dipolar aprotic solvents in predicting direction of dipole orientation

The addition of diazomethane to a series of substituted styrenes has been kinetically investigated with emphasis on polar, solvent, and solvation effects. Although the reaction is generally insensitive to solvent polarity, a sizeable substituent effect (ρ = +0.90) has been observed. Also, a sizeable increase in rate was generally observed in protic solvents such as water, and a considerable rate enhancement occurred in the case of nitrostyrene in the dipolar aprotic solvent, dimethylformamide. The results are discussed in terms of a concerted mechanism involving a partially-charged transition state II, with negative charge formation on the α-carbon of the styrene. The methoxystyrene offers an exception to the Hammett equation and the unexpectedly high rate constant for this compound could be discussed in terms of a possible participation of the highly nucleophilic resonance form of p-methoxystyrene and an α-addition via the transition state III. However, solvation effects in dimethylformamide (failure to obtain the anticipated rate increase) and the formation of a 3-substituted pyrazoline adduct from the cycloaddition reaction indicate steric control to predominate over electronic factors and β-addition to prevail unequivocally. It is proposed that solvation effects in protic solvents can be utilized to advantage in cycloaddition reactions leading to 1-pyrazolines, for which no other routes are available at the present time.
Associated production of Higgs bosons with tt¯ pairs

Associated production of Higgs bosons with top-antitop pairs at hadron colliders, pp\ensuremath{\rightarrow}Htt\ifmmode\bar\else\textasciimacron\fi{}X, is examined. By tagging on an isolated secondary lepton, e or \ensuremath{\mu}, from the t or t\ifmmode\bar\else\textasciimacron\fi{} decay, discovery of an intermediate-mass Higgs boson, ${\mathit{m}}_{\mathit{H}}$\ensuremath{\simeq}80--150 GeV, via H\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma} is rendered feasible at the Superconducting Super Collider (SSC) (\ensuremath{\surd}s =40 TeV). Allowing a factor-of-0.4 signal reduction for isolation cuts and selection efficiencies leaves about 21 events per SSC year for ${\mathit{m}}_{\mathit{H}}$\ensuremath{\simeq}80--130 GeV, and somewhat less for 130--150 GeV, above an anticipated small background. At the CERN Large Hadron Collider (\ensuremath{\surd}s =16 TeV), the cross section is reduced by about a factor of 1/8.
Behavior of Steiner systems of M 24

In this paper we show that no pair of Steiner systems S(5, 8, 24) can intersect in the octads of certain subspaces of the binary Golay code C, the 12-dimensional vector space over the field of two elements. In fact, we produce different numbers of Steiner systems that intersect in the octads of these subspaces. For every pair of Steiner systems S(5, 8, 24), and S1(5, 8, 24), there exists a permutation γ of $24, the symmetric group of degree 24, that maps the octads of S onto the octads of S1. An interesting method of finding γ is discussed.
A comprehensive overview of computational protein disorder prediction methods

Over the past decade there has been a growing acknowledgement that a large proportion of proteins within most proteomes contain disordered regions. Disordered regions are segments of the protein chain which do not adopt a stable structure. Recognition of disordered regions in a protein is of great importance for protein structure prediction, protein structure determination and function annotation as these regions have a close relationship with protein expression and functionality. As a result, a great many protein disorder prediction methods have been developed so far. Here, we present an overview of current protein disorder prediction methods including an analysis of their advantages and shortcomings. In order to help users to select alternative tools under different circumstances, we also evaluate 23 disorder predictors on the benchmark data of the most recent round of the Critical Assessment of protein Structure Prediction (CASP) and assess their accuracy using several complementary measures.
The immunoelectroadsorption method

Abstract The use of ellipsometry in immunological studies is described. After adsorption of an antigen on a slide, antibodies are then adsorbed. Ellipsometer thickness measurements accompany these procedures. Well denned differences are obtained between homologous and heterologous sera where an electric current of proper polarity is applied during the antigen and antibody adsorptions.
Responses of macaque ganglion cells to far violet lights

Abstract In a sample of 487 colour-opponent ganglion cells recorded in the central retina of the rhesus and cynomolgus monkeys, 9% of these neurones were found to have responses with the same sign at both ends of the visible spectrum mediated by red-sensitive cones and mid-spectral responses of opposite sign mediated by green-sensitive cones. Selective chromatic adaptation showed that the responses to far violet lights (400–420 nm) were due to input from red- and not blue-sensitive cones. These responses were enhanced by backgrounds depressing the sensitivity of blue- and green-sensitive cones and they were depressed by backgrounds depressing the sensitivity of red-sensitive cones; the sensitivity of these responses was yoked to that of responses to far red lights. The relative incidence of these ganglion cells was maximal at the foveal region and decreased towards the peripheral retina. The properties of these cells are consistent with some psychophysical observations of human vision at the short wave-lengths.
Modeling Ethylene/Methyl Methacrylate and Ethylene/Methacrylic Acid Copolymers Using Acyclic Diene Metathesis Chemistry

The synthesis, characterization, and thermal behavior of ADMET models of ethylene/methyl methacrylate (EMMA) and ethylene/methacrylic acid (EMAA) copolymers are described. These model copolymers exhibit sharper melting transitions and lower melting points relative to random copolymers made using chain-growth polymerization methods. The EMMA and EMAA model copolymers are compared with ADMET ethylene-based model copolymers reported previously, comparisons which support the earlier finding that melting points decrease with an increase in the steric bulk of the pendant group.
Monitoring and Performance: A Comparison of Computer and Supervisor Monitoring

This research addresses how computer monitoring affects the way individual workers perform on their jobs. The study tests the effects of a supervisor's physical versus electronic presence on individual worker performance. Forty-two women were hired to perform a simple data entry task. The women worked in one of three conditions: (a) alone, (b) in the physical presence of the supervisor who monitored their work, or (c) computer-monitored (electronic presence) by the data entry system without the physical presence of the supervisor. It was hypothesized that social facilitation effects would result from either the physical or electronic presence conditions. Electronic presence does seem to result in social facilitation, though the mean differences are not statistically significant. The results for physical presence are mixed. Profile analysis indicates that there are significant differences in the patterns of performance. When subjects work alone or with electronic presence, performance follows a steady pattern. When subjects work with physical presence, performance is somewhat lower than in the alone condition, except when the supervisor is actively monitoring, then individual performance is significantly increased. There are no satisfaction differences between the three conditions. The results of this research suggest that “Big Brother” is not lurking inside every computer-monitoring system.
Nonlinear Optical Properties of Structured Nanoparticle Composites

The effective nonlinear susceptibility X ( 3 ) for a composite that consists of a dilute suspension of structured nanoparticles that utilizes the surface mediated plasmon resonance can be enhanced by orders of magnitude compared to the intrinsic X (3) for a film of the same neat material. Here we report calculations for various multilayer spherical nanoparticle models in a host dielectric: i) polymeric core and metallic shell, ii) semiconductor core and metallic shell, iii) metallic core, polymeric shell and metallic second shell, and iv) metallic core, semiconductor shell and metallic second shell. The polymer is polydiacetylene, FDA, the semiconductor is Si, the metal is Ag, and the host is water, a GaAs 2 glass or Si. Enhancements as great as 10 4 can be obtained in both x (3) and the figure of merit with no degradation in the intrinsic speed of the nonlinearity. The choice of geometrical parameters and of component materials permit tailoring of the wavelength dependence and bandwidth characteristics of the nonlinear response. However, fabrication of these structured nanoparticle suspensions remians the key challenge.
Bioinformatic analysis of xenobiotic reactive metabolite target proteins and their interacting partners

Protein covalent binding by reactive metabolites of drugs, chemicals and natural products can lead to acute cytotoxicity. Recent rapid progress in reactive metabolite target protein identification has shown that adduction is surprisingly selective and inspired the hope that analysis of target proteins might reveal protein factors that differentiate target- vs. non-target proteins and illuminate mechanisms connecting covalent binding to cytotoxicity. Sorting 171 known reactive metabolite target proteins revealed a number of GO categories and KEGG pathways to be significantly enriched in targets, but in most cases the classes were too large, and the "percent coverage" too small, to allow meaningful conclusions about mechanisms of toxicity. However, a similar analysis of the directlyinteracting partners of 28 common targets of multiple reactive metabolites revealed highly significant enrichments in terms likely to be highly relevant to cytotoxicity (e.g., MAP kinase pathways, apoptosis, response to unfolded protein). Machine learning was used to rank the contribution of 211 computed protein features to determining protein susceptibility to adduction. Protein lysine (but not cysteine) content and protein instability index (i.e., rate of turnover in vivo) were among the features most important to determining susceptibility. As yet there is no good explanation for why some low-abundance proteins become heavily adducted while some abundant proteins become only lightly adducted in vivo. Analyzing the directly interacting partners of target proteins appears to yield greater insight into mechanisms of toxicity than analyzing target proteins per se. The insights provided can readily be formulated as hypotheses to test in future experimental studies.
Practicing Critical Democracy: A Perspective from Students

Through the experiences and voices of three high school students, this paper contributes to the conversation about utilizing a critical framework for civics education. Findings reveal that the traditional approach to civics education offers a strong content base, but fails to prepare students to expand notions about “good” citizens who are active participants in the democratic process. A critical approach that values civic participation through deliberation better prepares students to find multiple ways to participate in local, national, and global contexts.
Why Do Principals Change Schools? A Multivariate Analysis of Principal Retention

This study uses multivariate analysis of a large panel dataset to examine the determinants of principal retention (and, thus, the determinants of attracting a principal away from her current position). The empirical model incorporates measures of a principal's traits and of the organizational structure, culture, and situational context within a school. The discussion focuses on (1) the impact of salary, school characteristics, and principal traits and on (2) their associated policy implications. Evidence from the study suggests that schools with higher proportions of at-risk students and less-qualified teachers are disadvantaged with respect to their ability to retain (and attract) principals. At the same time, the evidence suggests that higher salaries can be used to compensate for these disparities.
Effect of an educational intervention about breastfeeding on the knowledge, confidence, and behaviors of pediatric resident physicians.

Objective. Breastfeeding is the preferred nutrition for infants, but many pediatricians report inadequate training to advise mothers who breastfeed. This study was designed to examine the effect of an educational intervention on pediatric residents’ knowledge about breastfeeding, their confidence in addressing lactation issues, and their management skills during clinical encounters with breastfeeding mothers. Design. An interactive multimedia curricular intervention was designed for pediatric residents to increase their knowledge about common lactation issues. The residents completed questionnaires before and after the intervention to measure knowledge and confidence. Resident behaviors in the clinical setting were measured before and after the intervention using telephone surveys of breastfeeding mothers after a clinic visit with a pediatric resident. Results. Forty-nine pediatric residents participated in the study. Mean knowledge scores increased from 69% before the intervention to 80% after the intervention. Significant increases in knowledge included advising mothers about low milk supply, mastitis, abscess, or using medication, and in recognizing the benefit of the decreased risk of maternal cancer. Management skills with breastfeeding mothers and infants in the clinical setting improved significantly. Before the intervention residents performed an acceptable number of behaviors 22% of the time, while after the intervention their performance was acceptable 65% of the time. Particular behaviors that showed significant improvement after the intervention included discussing signs of breastfeeding adequacy with the mother and correct management of lactation problems. Conclusions. These results indicate that not only breastfeeding knowledge and confidence, but most importantly clinical behaviors of pediatric residents can be enhanced through innovative educational opportunities. Appropriate counseling for breastfeeding mothers by pediatricians might contribute to an increase in the duration of breastfeeding.
Nocturnal methane accumulation in the pycnocline of an anoxic estuarine basin

Diel studies of vertical methane distributions were made on scvcn dates during five field expeditions over a period of 3 yr to the permanently anoxic southern basin of the Pettaquamscutt River estuary. On five occasions, methane concentrations were constant over a diel cycle, indicating balanced production and consumption. On two other occasions, methane concentrations varied dramatically between sunset and sunrise, increasing (and then decreasing) by up to several pmoles per liter between sunset and sunrise in the chlorophyll-rich pycnocline. Our observations on these two dates require a nocturnal imbalance between methane production and methane oxidation. Data from 1992 suggest that production exceeds oxidation in the early part of the cvcning and that oxidation exceeds production after around midnight. On other dates, production and consumption are balanced, although turnover rates could still be high. Methane concentration variations that occurred nocturnally did not seem to be associated with tidal or advective effects, as comparisons were made on density horizons, and very little lateral variability in methane concentrations was found along a longitudinal transect of the basin. Methane profiles taken during the day were essentially identical during each 2-week experiment. In all cases, methane concentrations in the surface waters above the pycnocline were -0.1-0.2 PM and remained constant over the sampling period.
SOME OBSERVATIONS ON THE NUCLEAR ENVELOPE

In maize root meristem cells, fixed in KMnO4, embedded in epoxy resin, ultrathin sectioned, and studied with an electron microscope, the nuclear envelope is demonstrated to be a double membrane structure. In the nuclear envelope there are: pores of the sort reported in many species of animals and plants; different types of openings associated with extensions of both nuclear membranes into the cytoplasm; and also, often, large discontinuities. The nuclear envelope is a component of the general vesicular reticulum. The reticula of neighboring cells including the nuclear envelopes make up, at certain stages at least, a "systemic" structure. The status of the nuclear envelope as a component of the general cellular reticulum is recognized to change during differentiation. The existence of several types of discontinuities in the nuclear envelope and the extent of nuclear-cytoplasmic surface relationships indicated suggests alteration in concepts of transport and exchanges between nucleus and cytoplasm.
Acutely administered ethanol participates in testosterone synthesis and increases testosterone in rat brain.

Background: The interaction of alcohol and testosterone has long been of interest, mainly due to the effect of alcohol on aggression and sexual behavior. To date, there have been very few, if any, studies examining the effect of acute alcohol administration on testosterone concentrations in the brain. The administration of 1,1-dideuteroethanol ([1,1- 2 H2]ethanol) provided the opportunity to trace the deuterium label into newly synthesized deuterotestosterone in brain samples to determine whether ethanol oxidation was directly linked to testosterone synthesis. Methods: Unoperated and adrenalectomized-gonadectomized (ADX/GDX) rats were given either ethanol or [1,1- 2 H2]ethanol in a single intraperitoneal dose of 2 g/kg body weight. We used gas chromatography/mass spectrometry to accurately determine both the amount of steroids present and the degree of deuterium incorporation into specific steroids isolated from brain samples. Results: Thirty minutes after alcohol administration, the level of total testosterone increased 4-fold in the frontal cortex and 3-fold in the plasma of unoperated male Wistar rats. The relative increase in the abundance of monodeuterated testosterone 30 min after [1,1- 2 H2]ethanol administration was significant (p 0.05) in both brain and plasma. ADX/GDX animals treated with alcohol had testosterone concentrations that were 5% of those found in unoperated animals dosed with ethanol. Conclusions: Acutely administered ethanol increased brain concentrations of testosterone 4-fold in male Wistar rats. ADX/GDX surgery reduced brain concentrations of testosterone in response to alcohol by 95%. The deuterium labeling of testosterone after [1,1- 2 H2]ethanol showed that ethanol oxidation is directly linked to testosterone biosynthesis and that the deuterium-labeled testosterone is present in the central nervous system. These results demonstrate that peripherally administered ethanol directly contributes to the concentrations of testosterone in the central nervous system and that the testosterone found in brain samples is primarily synthesized in the periphery. These findings may be important for understanding the behavioral changes associated with acute alcohol consumption.
Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability.

A blue light (cryptochrome) photoreceptor from Arabidopsis, cry1, has been identified recently and shown to mediate a number of blue light–dependent phenotypes. Similar to phytochrome, the cryptochrome photoreceptors are encoded by a gene family of homologous members with considerable amino acid sequence similarity within the N-terminal chromophore binding domain. The two members of the Arabidopsis cryptochrome gene family ( CRY1 and CRY2 ) overlap in function, but their proteins differ in stability: cry2 is rapidly degraded under light fluences (green, blue, and UV) that activate the photoreceptor, but cry1 is not. Here, we demonstrate by overexpression in transgenic plants of cry1 and cry2 fusion constructs that their domains are functionally interchangeable. Hybrid receptor proteins mediate functions similar to cry1 and include inhibition of hypocotyl elongation and blue light–dependent anthocyanin accumulation; differences in activity appear to be correlated with differing protein stability. Because cry2 accumulates to high levels under low-light intensities, it may have greater significance in wild-type plants under conditions when light is limited.
CMOS-compatible AlN piezoelectric micromachined ultrasonic transducers

Piezoelectric micromachined ultrasonic transducers for air-coupled ultrasound applications were fabricated using aluminum nitride (AlN) as the active piezoelectric layer. The AlN is deposited via a low-temperature sputtering process that is compatible with deposition on metalized CMOS wafers. An analytical model describing the electromechanical response is presented and compared with experimental measurements. The membrane deflection was measured to be 210 nm when excited at the 220 kHz resonant frequency using a 1V pp input voltage.
Corporate Communications: Comparing Executives' Private and Public Statements

People frame and make sense of their worlds through the use of cognitive categories, which researchers can only indirectly access. Public corporate statements are easily accessible and comparable a...
Atomic Electron Affinities

New binding energy information is presented for P$sup 3$ and Fe$sup 4$. A table is given showing the recommended electron affinities for the ground state atom of the main body of the periodic table and the three long series. (JFP)
Effect of Interfacial Resistance on Determination of Transport Properties of Mixed‐Conducting Electrolytes

Combination of impedance spectroscopy and open‐cell voltage measurements has been used to determine the transport properties of mixed‐conducting electrolytes. It is clearly demonstrated experimentally that the ratio of open‐cell voltage to the applied Nernst potential can be quite different from the average ionic transference number; the effect of interfacial polarization resistance on determination of transference numbers of a mixed‐conducting electrolyte must be carefully analyzed, particularly for a cell based on a thin electrolyte, tested at low temperatures, or exposed to an atmosphere containing low activities of electroactive species.
Ultrasonic metamaterials with negative modulus

The emergence of artificially designed subwavelength electromagnetic materials, denoted metamaterials, has significantly broadened the range of material responses found in nature. However, the acoustic analogue to electromagnetic metamaterials has, so far, not been investigated. We report a new class of ultrasonic metamaterials consisting of an array of subwavelength Helmholtz resonators with designed acoustic inductance and capacitance. These materials have an effective dynamic modulus with negative values near the resonance frequency. As a result, these ultrasonic metamaterials can convey acoustic waves with a group velocity antiparallel to phase velocity, as observed experimentally. On the basis of homogenized-media theory, we calculated the dispersion and transmission, which agrees well with experiments near 30 kHz. As the negative dynamic modulus leads to a richness of surface states with very large wavevectors, this new class of acoustic metamaterials may offer interesting applications, such as acoustic negative refraction and superlensing below the diffraction limit.
The Peopling of the New World: Perspectives from Molecular Anthropology

▪ Abstract A number of important insights into the peopling of the New World have been gained through molecular genetic studies of Siberian and Native American populations. These data indicate that the initial migration of ancestral Amerindian originated in south-central Siberia and entered the New World between 20,000–14,000 calendar years before present (cal yr BP). These early immigrants probably followed a coastal route into the New World, where they expanded into all continental regions. A second migration that may have come from the same Siberian region entered the Americas somewhat later, possibly using an interior route, and genetically contributed to indigenous populations from North and Central America. In addition, Beringian populations moved into northern North America after the last glacial maximum (LGM) and gave rise to Aleuts, Eskimos, and Na-Dene Indians.