cssi/SciSciGPT-SciSciNet huggingface dataset:
A Near-Infrared Search for Line Emission from Protogalaxies Using the W. M. Keck Telescope

We present the first results from a near-infrared narrowband search for primeval galaxies (PGs) using the Keck 10 m telescope. We have targeted our fields for three QSOs and one radio galaxy at redshifts z = 2.28 to z = 4.70. We selected narrowband filters in the K band centered on strong emission lines at the redshift of the targets. We reach limiting fluxes between 1.6 × 10-17 and 1.0 × 10-16 ergs s-1 cm-2, and cover a total area of ~4 arcmin2. At the redshifts of interest, these flux limits correspond to typical rest-frame line luminosities of ~1042-1043 ergs s-1, unobscured star formation rates of ~1-100 M☉ yr-1, and a sampled comoving volume of several tens of Mpc3. We have found no candidate PGs at a 2 σ confidence level. We demonstrate that for moderate dust absorption (AV 2 mag) in a simple dust-screen model, our preliminary survey puts a strong constraint on intrinsic PG luminosities during an initial burst of star formation. In the case of the QSOs, we have used point-spread function subtraction to search for the presence of faint, extended line emission surrounding these radio-quiet active galactic nuclei. We find no evidence for extended emission down to 3.7 × 10-17 ergs s-1 cm-2. This imposes limits on the reprocessed fraction of the QSO continuum emission ranging between 0.02% and 0.29%; if beaming effects are not important, then this implies similarly small covering factors for clouds optically thick to the QSO continuum emission.
Temporal Oculomotor Inhibition of Return and Spatial Facilitation of Return in a Visual Encoding Task

*Correspondence: John M. Henderson, Visual Cognition Laboratory, Institute for Mind and Brain and Department of Psychology, University of South Carolina, 1800 Gervais Street, Columbia, SC 29208, USA e-mail: john.henderson@sc.edu Oculomotor inhibition of return (O-IOR) is an increase in saccade latency prior to an eye movement to a recently fixated location compared to other locations. It has been proposed that this temporal O-IOR may have spatial consequences, facilitating foraging by inhibiting return to previously attended regions. In order to test this possibility, participants viewed arrays of objects and of words while their eye movements were recorded.Temporal O-IOR was observed, with equivalent effects for object and word arrays, indicating that temporal O-IOR is an oculomotor phenomenon independent of array content.There was no evidence for spatial inhibition of return (IOR). Instead, spatial facilitation of return was observed: participants were significantly more likely than chance to make return saccades and to refixate just-visited locations. Further, the likelihood of making a return saccade to an object or word was contingent on the amount of time spent viewing that object or word before leaving it. This suggests that, unlike temporal O-IOR, return probability is influenced by cognitive processing. Taken together, these results are inconsistent with the hypothesis that IOR functions as a foraging facilitator. The results also provide strong evidence for a different oculomotor bias that could serve as a foraging facilitator: saccadic momentum, a tendency to repeat the most recently executed saccade program.We suggest that models of visual attention could incorporate saccadic momentum in place of IOR.
A new strategy for cyclopentenone synthesis.

A new strategy for the synthesis of 2,3-disubstituted cyclopentenones emerges from two key reactionsthe ruthenium-catalyzed three-component coupling of an equivalent of HBr, an alkyne, and a vinyl ketone and the Ni−Cr Barbier type reaction. As a result, these important structures are readily accessed from an alkyne and a vinyl ketone (which derive directly from carboxylic acids). Syntheses of tetrahydrodicranenone B and rosaprostol illustrate the new strategy.
Distributed-memory computing with the Langley aerothermodynamic upwind relaxation algorithm (LAURA)

The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), a Navier-Stokes solver, has been modified for use in a parallel, distributed-memory environment using the Message-Passing Interface (MPI) standard. A standard domain decomposition strategy is used in which the computational domain is divided into sub-domains with each sub-domain assigned to a processor. Performance is examined on dedicated parallel machines and a network of desktop workstations. The effect of domain decomposition and frequency of boundary updates on performance and convergence is also examined for several realistic configurations and conditions typical of large-scale computational fluid dynamic analysis.
Self-Efficacy: A Key to Improving the Motivation of Struggling Learners.

(2004). Self-Efficacy: A Key to Improving the Motivation of Struggling Learners. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 77, No. 6, pp. 241-249.
ON GENERALIZED WINDING NUMBERS

Let M m be an oriented manifold, let N m 1 be an oriented closed manifold, and let p be a point in M m . For a smooth map f : N m 1 ! M m , p / 2 Im f, we introduce an invariant awinp(f) that can be regarded as a generalization of the classical winding number of a planar curve around a point. We show that awinp estimates from below the number of times a wave front on M passed through a given point p 2 M between two moments of time. Invariant awinp allows us to formulate the analogue of the complex analysis Cauchy integral formula for meromorphic functions on complex surfaces of genus bigger than one.
Green, red, and IR frequency comb line generation from single IR pump in AlN microring resonator

On-chip frequency comb generations enable compact broadband sources for spectroscopic sensing and precision spectroscopy. Recent microcomb studies focus on the infrared spectral regime and have difficulty accessing the visible regime. We demonstrate comb-like visible frequency line generation through second-harmonic, third-harmonic, and sum-frequency conversion of a Kerr comb within a high-Q aluminum nitride (AlN) microring resonator pumped by a single telecom laser. The strong power enhancement, in conjunction with the unique combination of Pockels (χ2) and Kerr (χ3) optical nonlinearity of AlN, leads to cascaded frequency conversions in the visible spectrum. High-resolution spectroscopic study of the visible frequency lines indicates matched free spectrum range over all the bands. This frequency doubling and tripling effect in a single microcomb structure offers great potential for comb spectroscopy and self-referencing comb.
Tandem transannular radical cyclizations. Total syntheses of (±)-modhephene and (±)-epi-modhephene

Abstract Modhephene and epi -modhephene have been synthesized by a new tandem transannular radical cyclization strategy. The key tandem cyclization is conducted by the Barton thiohydroxamate method with an exo(methylene)cyclooctane.
Effects of Charge on Osmotic Reflection Coefficients of Macromolecules in Fibrous Membranes

A model based on continuum hydrodynamics and electrostatics was developed to predict the combined effects of molecular charge and size on the osmotic reflection coefficient (σo) of a macromolecule in a fibrous membrane, such as a biological hydrogel. The macromolecule was represented as a sphere with a constant surface charge density, and the membrane was assumed to consist of an array of parallel fibers of like charge, also with a constant surface charge density. The flow was assumed to be parallel to the fiber axes. The effects of charge were included by computing the electrostatic free energy for a sphere interacting with an array of fibers. It was shown that this energy could be approximated using a pairwise additivity assumption. Results for σo were obtained for two types of negatively charged fibers, one with properties like those of glycosaminoglycan chains, and the other for thicker fibers having a range of charge densities. Using physiologically reasonable fiber spacings and charge densities, σo for bovine serum albumin in either type of fiber array was shown to be much larger than that for an uncharged system. Given the close correspondence between σo and the reflection coefficient for filtration, the results suggest that the negative charge of structures such as the endothelial surface glycocalyx is important in minimizing albumin loss from the circulation.
The Brightest Point X-Ray Sources in Elliptical Galaxies and the Mass Spectrum of Accreting Black Holes

We propose that the shape of the upper-end X-ray luminosity function (XLF) observed in elliptical galaxies for point sources carries valuable information about the black hole (BH) mass spectrum among old X-ray transients formed in the galaxies. Here we present the line of arguments and analysis that support this connection and the methodology for deriving the BH mass spectrum slope from the observed XLF slope. We show that this underlying BH mass spectrum is modified by a weighting factor that is related to the transient duty cycle, and it generally depends on the host galaxy age, the BH mass, and the X-ray binary (XRB) donor type (main-sequence, red giant, or white dwarf donors). We find that the observed XLF is dominated by transient BH systems in outburst (a prediction possibly testable by future observations) but that the assumption of a constant duty cycle for all systems leads to results inconsistent with current observations. We also find that the derived BH mass slope depends on the strength of the angular momentum loss due to magnetic braking for main-sequence donors. More specifically, we find that for "standard" magnetic braking, BH XRBs with red giant donors dominate the upper-end XLF but that for weaker magnetic braking prescriptions, main-sequence donors are found to be dominant. The methodology presented here can be used in the future as our understanding of the transient duty and its dependence on binary and mass transfer properties improves. Under certain assumptions for this dependence, we derive a differential BH mass spectrum slope of 2.5; an upper BH mass cutoff at 20 M☉ is needed to understand the very brightest of the BH XRBs in elliptical galaxies. We also show that our quantitative results are robust against expected variations by factors of a few of the outburst peak X-ray luminosities. We expect that our analysis will eventually help to constrain binary population synthesis models and the adopted relations between black holes and the masses of their progenitors.
High-Q, low index-contrast polymeric photonic crystal nanobeam cavities

We present the realization of high-Q (Q=36,000) polymeric photonic crystal nanobeam cavities made of two polymers that have an ultra-low index contrast (ratio=1.15), and demonstrate that these polymer cavities are outstanding refractive index sensors (FOM=9190).
Political resistance in Chinese mergers and acquisitions: An interview with Ted Tokuchi

Introduced in Ted’s interview in introductory section, Ted Tokuchi built CITIC Securities’ investment banking division from a nascent group into the top investment banking department in China. A significant part of CITIC Securities’ IB work is advising multinational firms, both Chinese and foreign, about cross-border mergers and acquisitions. In this interview, Ted discusses these efforts and the resistance which different firms encounter when pursuing a foreign target. Again, Ted is tri-lingual in English, Chinese and Japanese, is presently managing director of CITIC Securities Co Ltd and chairman of CITIC Securities International, and is the first foreign senior manager employed by Chinese securities industry.
Spectra for compact quantum group coactions and crossed products

We present definitions of both Connes spectrum and strong Connes spectrum for actions of compact quantum groups on C*-algebras and obtain necessary and sufficient conditions for a crossed product to be a prime or a simple C*-algebra. Our results extend to the case of compact quantum ac- tions the results in (8) which in turn, generalize results by Connes, Olesen and Pedersen and Kishimoto for abelian group actions. We prove in addition that the Connes spectra are closed under tensor products. These results are new for compact nonabelian groups as well.
Still waiting for Mister Right? Asymmetric information, abortion laws and the timing of marriage

Previous studies have suggested that more liberal abortion laws should lead to a decrease in marriage rates among young women as ‘shotgun weddings’ are no longer necessary. Empirical evidence from the United States lends support to that hypothesis. This article presents an alternative theory of abortion access and marriage based on the cost of search which suggests that more liberal abortion laws may actually promote young marriage. An empirical examination of marriage data from Eastern Europe shows that countries that liberalized their abortion laws saw an increase in marriage rates among nonteenage women.
FIRST Bent-Double Radio Sources: Tracers of High-Redshift Clusters*

Bent-double radio sources can act as tracers for clusters of galaxies. We present imaging and spectroscopic observations of the environments surrounding 10 of these sources (most of them wide-angle tails [WATs]) selected from the VLA FIRST survey. Our results reveal a previously unknown cluster associated with eight of the radio sources with redshifts in the range 0.33 < z < 0.85; furthermore, we cannot rule out that the other two bent doubles may be associated with clusters at higher redshift. Richness measurements indicate that these clusters are typical of the majority of those found in the Abell catalog, with a range of Abell richness classes from 0 to 2. The line-of-sight velocity dispersions are very different from cluster to cluster, ranging from approximately 300 to 1100 km s-1. At the upper end of these intervals, we may be sampling some of the highest redshift massive clusters known. Alternatively, the large velocity dispersions measured in some of the clusters may indicate that they are merging systems with significant substructure, consistent with recent ideas concerning WAT formation (Burns et al.).
N-Alkylation of Amino Acid Esters Using Sodium Triacetoxyborohydride

Abstract N-Alkylation of amino acid esters by reductive amination using sodium cyanoborohydride may often be problematic. Sodium triacetoxyborohydride was found to be a convenient reagent for this transformation. This methodology was employed to alkylate various amino acid methyl esters.
Particle-image velocimetry measurement errors when imaging through a transparent engine cylinder

When making particle-image velocimetry measurements through the quartz cylinder of a reciprocating engine, the particle images are aberrated. This work quantifies the practical field-of-view and the errors in the velocity measurements caused by those aberrations. Electro-optical image shifting was used to create a repeatable particle-image displacement distribution for 60 images. Ensemble averaging of these images is used to quantify the rms errors due to the shot-to-shot variation in (1) the particle-image fields, (2) the camera noise, (3) the variance in the correlation-peak detection and (4) the particle-image aberrations. These results demonstrate that the field-of-view is restricted to the centre 66 mm of the 86 mm inside-diameter cylinder due to decreased accuracy, decreased image-to-image precision and decreased displacement-peak detectability of the image-displacement correlation. The correlation-peak detectability was degraded by both particle-image aberrations and decreased transmission of the scattered light.
Creating Ties That Bind

The work of Donaldson and Dunfee (Ties That Bind: A Social Contracts Approach to Business Ethics, 1999) offers an example of how normative and descriptive approaches to business ethics can be integrated. We suggest that to be truly integrative, however, the theory should explore the processes by which such integration happens. We, therefore, sketch some preliminary thoughts that extend Integrative Social Contracts Theory (ISCT) by beginning to consider the process by which microsocial contracts are connected to hypernorms.
Calculations of hot gas ingestion for a STOVL aircraft model

Hot gas ingestion problems for STOVL (Short Take-Off, Vertical Landing) aircraft are typically approached with empirical methods and experience. In this study, the hot gas environment around a STOVL aircraft was modeled as multiple jets in crossflow with inlet suction. The flow field was calculated with a Navier-Stokes, Reynolds-averaged, turbulent, 3D CFD code using a multigrid technique. A simple model of a STOVL aircraft with four choked jets at 1000 K was studied at various heights, headwind speeds, and thrust splay angles in a modest parametric study. Scientific visualization of the computed flow field shows a pair of vortices in front of the inlet. This and other qualitative aspects of the flow field agree well with experimental data.
The magical number seven plus or minus two: some limits on our capacity for processing information

First, the span of absolute judgment and the span of immediate memory impose severe limitations on the amount of information that we are able to receive, process, and remember. By organizing the stimulus input simultaneously into several dimensions and successively into a sequence or chunks, we manage to break (or at least stretch) this informational bottleneck. Second, the process of recoding is a very important one in human psychology and deserves much more explicit attention than it has received. In particular, the kind of linguistic recoding that people do seems to me to be the very lifeblood of the thought processes. Recoding procedures are a constant concern to clinicians, social psychologists, linguists, and anthropologists and yet, probably because recoding is less accessible to experimental manipulation than nonsense syllables or T mazes, the traditional experimental psychologist has contributed little or nothing to their analysis. Nevertheless, experimental techniques can be used, methods of recoding can be specified, behavioral indicants can be found. And I anticipate that we will find a very orderly set of relations describing what now seems an uncharted wilderness of individual differences. Third, the concepts and measures provided by the theory of information provide a quantitative way of getting at some of these questions. The theory provides us with a yardstick for calibrating our stimulus materials and for measuring the performance of our subjects. In the interests of communication I have suppressed the technical details of information measurement and have tried to express the ideas in more familiar terms; I hope this paraphrase will not lead you to think they are not useful in research. Informational concepts have already proved valuable in the study of discrimination and of language; they promise a great deal in the study of learning and memory; and it has even been proposed that they can be useful in the study of concept formation. A lot of questions that seemed fruitless twenty or thirty years ago may now be worth another look. In fact, I feel that my story here must stop just as it begins to get really interesting. And finally, what about the magical number seven? What about the seven wonders of the world, the seven seas, the seven deadly sins, the seven daughters of Atlas in the Pleiades, the seven ages of man, the seven levels of hell, the seven primary colors, the seven notes of the musical scale, and the seven days of the week? What about the seven-point rating scale, the seven categories for absolute judgment, the seven objects in the span of attention, and the seven digits in the span of immediate memory? For the present I propose to withhold judgment. Perhaps there is something deep and profound behind all these sevens, something just calling out for us to discover it. But I suspect that it is only a pernicious, Pythagorean coincidence.
Generation of squeezed radiation from a free electron laser

Abstract We demonstrate that squeezed states of the radiation field in a free electron laser are possible only in the small gain and inverse regimes. Moreover, in these regimes, the feasibility of generating squeezed radiation is severely constrained by the quantum fluctuations in the initial states of the electron beam.
Kimberlitic diatremes in northern Colorado and southern Wyoming

Abstract Thirty-six kimberlitic diatremes and dikes occur in a north-south zone in the Precambrian core of the Colorado-Wyoming Front Range. A group of nineteen of apparent Middle Paleozoic age, near the state line, has been studied in detail. These pipes of intrusive breccia contain a varied assortment of nodular material, including spinel and garnet lherzolite, eclogite, distinctive carbonatite (sovite), and large megacrysts of orthopyroxene, garnet, ilmenite, and both chromian and non-chromian diopside. The upper mantle through which kimberlite rose is interpreted to have consisted of spinel peridotite from the base of the crust at 50 km to about 100 km and garnet peridotite below. Pockets of eclogite occurred at about 85–110 km. Chemistry of peridotites reflects partial melting before inclusion in kimberlite. A melt or melts of different chemical character, possibly cognate to kimberlite, has precipitated diopside, garnet and ilmenite.
An Improved Larock Synthesis of Quinolines via a Heck Reaction of 2-Bromoanilines and Allylic Alcohols

A modified Larock method has been developed for the one-pot synthesis of substituted quinolines via a Heck reaction of 2-bromoanilines and allylic alcohols followed by dehydrogenation with diisopropyl azodicarboxylate (DIAD).
CONVENIENT WACKER OXIDATIONS WITH SUBSTOICHIOMETRIC CUPRIC ACETATE

Abstract A modification of the Wacker oxidation of terminal olefins to methyl ketones using substoichiometric amounts of Cu(OAc) 2 as a redox shuttle reagent is described. The modified procedure is generally high yielding despite reduced levels of copper salt and convenient. Importantly, in a problematic case, the conditions suppressed acidic hydrolysis during oxidation of substrate (+)- 5 containing an acetonide.
Strongly interacting longitudinal gauge bosons in supersymmetric models

Abstract A non-linear sigma model effective lagrangian is analyzed for theories in which supersymmetry is softly broken at scales below the electroweak symmetry breaking scale. Besides the gauge and matter supermultiplets, the low energy theory contains only three Goldstone chiral multiplets. The higgsino, gaugino as well as the charged and neutral Higgs bosons have (light) phenomenologically acceptable masses, the values of which depend on the explicit soft supersymmetry breaking parameters. In addition, the longitudinal vector bosons become strongly interacting at high energies ( M z ⪡ E ⪡ 4 πν ). The equivalence theorem is exploited in order to obtain their scattering amplitudes. Furthermore, supersymmetry results in enhanced longitudinal vector boson production of Higgs bosons.
Site Preference and Si/B Mixing in Mixed-Alkali Borosilicate Glasses: A High-Resolution 11B and 17O NMR Study

In a series of mono and mixed-alkali borosilicate glasses (∼0.7M2O·B2O3·2SiO2, M = Li, Na, K, (1/2Li2O + ∼1/2Na2O), (1/2Li2O + 1/2K2O), and (∼1/2Na2O + 1/2K2O)), we have applied triple-quantum magic-angle spinning (3QMAS) and 11B and 17O NMR to obtain high-resolution information about short-range structure and the connections among various network structural units, to study the effect of mixed cations on the glass structure, and to explore the distribution and mixing of these modifier cations. For a Li-containing glass, a lower fraction of [4]B, a lower fraction of Si−O−B, and a higher fraction of nonbridging oxygen than those found in Na- and K-containing glasses suggests that there is a significant heterogeneity in terms of Si/B mixing in the former. For Li−Na and Li−K mixed cation glasses, anomalously high fractions of nonbridging oxygen were also observed along with smaller fractions of [4]B and Si−O−B, again indicating significant chemical heterogeneity. For Na−K mixed cation glasses, the populations...
Scanning tunneling microscopy of mercapto-hexyl-oligonucleotides attached to gold

6-mercapto hexyl-oligonucleotides bind to a gold surface strongly enough to permit imaging by a scanning tunneling microscope (STM). STM images showed worm-like chains that were approximately 12-(A-wide for single-stranded DNA and 20-(A-wide for double-stranded DNA. The chain lengths corresponded to 3.4 +/- 0.4 A per basepair for double-stranded DNA and 2.2 +/- 0.4 A per base for single-stranded DNA. This unexpectedly short length for single-stranded DNA was confirmed using oligomers with both single- and double-stranded regions. When the attachment of the samples was weakened (by imaging in water or scraping with the STM tip) the images changed to pairs of "blobs," apparently reflecting the attachment points of the molecules to the gold surface. Given this interpretation, images of DNA containing a five-base bulge imply that the bulge bends the oligomer by 90 degrees +/- 20 degrees.
Damage development in bolt bearing of composite laminates

The buildup of damage in bolt-loaded specimens has been investigated. Destructive evaluation by staining, dissection, and microscopy was used to evaluate the complete three-dimensional geometry of the damage zone at several load levels and loading conditions for glass and graphite fiber-reinforced epoxy laminates with the stacking sequence [ [O/ + 457 45] 5/0] s. The assumed stress hybrid finite element method was used to determine the elastic stress distributions, including simulations of no friction and no sliding. Three sets of tests are included: a fastened bolt joint in tension, a fastened bolt joint in compression, and a fastened bolt hole in tension. Complete damage characteristics and stress distributions are even ply by ply through the thickness as a function of load. The local strength around the hole boundary is examined pointwise by the Tsai-Hill criterion; the maximum stress criterion is then used to determine the failure mode. First-ply failure criteria are applied and compared with experiments. The three sets of tests indicate that the damage zones of the net-tension and bearing-compression regions are independent at both the initiation and failure stages. Implications for gross failure criteria are discussed, and the need for more sophisticated methods is demonstrated. Attempts have been made to correlate actual damage zones with Whitney-Nuismer distance parameters, but no physical interpretation of these parameters appears justified.
Gamma-Ray Polarimetry of Two X-Class Solar Flares

We have performed the first polarimetry of solar flare emission at γ-ray energies (0.2-1 MeV). These observations were performed with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES X4.8-class solar flare of 2002 July 23 and the X17-class flare of 2003 October 28. We have marginal polarization detections in both flares, at levels of 21% ± 9% and -11% ± 5%, respectively. These measurements significantly constrain the levels and directions of solar flare γ-ray polarization and begin to probe the underlying electron distributions.
Stochastic surveillance strategies for spatial quickest detection

We design persistent surveillance strategies for the quickest detection of anomalies taking place in an environment of interest. From a set of predefined regions in the environment, a team of autonomous vehicles collects noisy observations, which a control center processes. The overall objective is to minimize detection delay while maintaining the false-alarm rate below a desired threshold. We present joint (i) anomaly detection algorithms for the control center and (ii) vehicle routing policies. For the control center, we propose parallel cumulative sum (CUSUM) algorithms (one for each region) to detect anomalies from noisy observations. For the vehicles, we propose a stochastic routing policy, in which the regions to be visited are chosen according to a probability vector. We study stationary routing policy (the probability vector is constant) as well as adaptive routing policies (the probability vector varies in time as a function of the likelihood of regional anomalies). In the context of stationary policies, we design a performance metric and minimize it to design an efficient stationary routing policy. Our adaptive policy improves upon the stationary counterpart by adaptively increasing the selection probability of regions with high likelihood of anomaly. Finally, we show the effectiveness of the proposed algorithms through numerical simulations and a persistent surveillance experiment.
Surface enhanced Raman spectroelectrochemical studies of the corrosion films on iron and chromium in aqueous solution environments

“In situ” laser Raman spectra of the corrosion films on iron have been observed in aerated 5 M KOH and 0.15 M NaCl solutions via surface enhancement by the electrodeposition of a silver overlayer. Essentially the same spectra are observed in the two solutions as a function of applied potential in spite of a breakdown of passivity on iron in the chloride solution. Fe(OH)2 and Fe3O4 are found in the prepassive potential region while FeOOH is present in the passive region. A film which is very difficult to reduce appears to be always present on the electrode surface even at hydrogen evolution potentials; this film is believed to be α-FeOOH. Surface enhanced Raman spectra of the corrosion films on chromium have also been obtained in NaCl solution for the first time. The passive film has a composition that corresponds most closely to an amorphous form of Cr2O3, with some Cr(OH)3 also present. The film is converted in the transpassive region to a higher oxide form, presumably CrO2−4. Reversible reduction of this species to Cr2O3 is indicated.
When does division of labor lead to increased system output

This paper develops a set of simplified dynamical models with which to explore the conditions under which division of labor leads to optimized system output, as measured by the rate of production of a given product. We consider two models: in the first model, we consider the flow of some resource into a compartment, and the conversion of this resource into some product. In the second model, we consider the growth of autoreplicating systems. In this case, we divide the replication and metabolic tasks among different agents. The general features that emerge from our models is that division of labor is favored when the resource to agent ratio is at intermediate values, and when the time cost associated with transporting intermediate products is small compared to characteristic process times. The results of our model are consistent with the behavior of the cellular slime mold Dictyostelium discodeum, which switches from a single-celled to a multi-celled state when resources become limited. We also argue that division of labor in the context of our replication model suggests an evolutionary basis for the emergence of the stem-cell-based tissue architecture in complex organisms. Finally, the results of this paper may be useful for understanding how, in an economic context, firm productivity is maximized at intermediate firm sizes.
Modified Busemann-Petty problem on sections of convex bodies

The Busemann-Petty problem asks whether convex origin-symmetric bodies in ℝ n with smaller central hyperplane sections necessarily have smallern-dimensional volume. It is known that the answer is affirmative ifn≤4 and negative ifn≥5. In this article we replace the assumptions of the original Busemann-Petty problem by certain conditions on the volumes of central hyperplane sections so that the answer becomes affirmative in all dimensions.
Graphical literacy: the quality of graphs in a large-circulation journal.

Abstract Study objective: We sought to characterize the quantity and quality of graphs in the Journal of American Medicine (JAMA) , contrasting articles published in 1999 with those published in 2000 after the addition of a dedicated tables and figures editor. We also sought to compare the quality of graphs in JAMA with the quality of graphs in Annals of Emergency Medicine . Methods: Two reviewers independently assessed all graphs in original research articles from 12 randomly chosen issues of JAMA , 6 each from 1999 and 2000, using a standardized abstraction form. We noted graph type, clarity, and completeness and identified internal discrepancies. We examined the graphs and articles to observe discrepancies with text, to observe efficiency of graph presentation, and to determine whether the graph portrayed unaggregated data. Results were compared with results from a previously published study of graphs from 18 consecutive issues of Annals of Emergency Medicine beginning in January 1998. Results: The 12 JAMA issues contained 56 research articles, with 64 graphs in the 37 articles that had graphs (28 in 27 1999 articles, 36 in 29 2000 articles). Simple bar or point charts (63%) predominated. We rarely encountered internal errors (8%), contradictions with text (3%), numeric distortion (6%), lack of visual clarity (5%), nonstandard graphing conventions (11%), or extraneous decoration (0%). Graphs generally defined all symbols (98%), but 31% were not self-explanatory; that is, despite knowing the study's design and reading the figure's legend, we could not unambiguously interpret the graph. Fourteen percent contained redundancies. Graphs infrequently portrayed by-subject data (9%) or advanced features (15%) such as pairing, symbolic dimensionality, or small multiples. Forty-eight percent (21/44) of graphs did not illustrate the underlying distribution, 48% (26/54) did not depict important covariates, and 67% (14/21) did not portray pairing inherent in the data. There were no differences between 1999 and 2000 graphs, although we noted more graphs in the 2000 issues. Graph quality was similar in Annals of Emergency Medicine and JAMA , but graphs were more common in the original research articles in JAMA . Although univariate displays predominated in both publications, there were more bivariate displays in Annals of Emergency Medicine but fewer advanced graphic features. Conclusion: The graphs in JAMA were similar to those in Annals of Emergency Medicine and, although generally clear and without errors, often failed to depict detailed data. Authors and editors could improve data presentations by incorporating graphic formats that depict stratified, detailed data. [ Ann Emerg Med. 2002;40:317-322.]
Satellite-observed latent heat release in a tropical cyclone

Data from the Nimbus 5 electrically scanning microwave radiometer (ESMR) are used to make calculations of the latent heat release (L.H.R.) and the distribution of rainfall rate in a tropical cyclone as it grows from a tropical disturbance to a typhoon. The L.H.R. (calculated over a circular area of 4 deg latitude radius) increases during the development and intensification of the storm from a magnitude of 2.7 X 10 to the 21st power ergs/s (in the disturbance stage) to 8.8 X 10 to the 21st power ergs (typhoon stage). The latter value corresponds to a mean rainfall rate of 2.0 mm hr/s. The more intense the cyclone and the greater the L.H.R., the greater the percentage contribution of the larger rainfall rates to the L.H.R. In the disturbance stage the percentage contribution of rainfall rates less than or minus 6 mm hr/s is typically 8%; for the typhoon stage, the value is 38%. The distribution of rainfall rate as a function of radial distance from the center indicates that as the cyclone intensifies, the higher rainfall rates tend to concentrate toward the center of the circulation.
Some Useful Bis(Trimethylsilylamino)Silanes

Abstract The preparation and characterization of CH3(R)Si(Cl)N(SiMe3)2, CH3(R)Si(NH2)N(SiMe3)2 and CH3(R)Si(NHSiMe3)2 (R = H, CH2=CH, Ph, Me) are described, as is the use of CH3(H)Si(NHSiMe3)2 in the synthesis of .
The genetics of addictions: Uncovering the genes

The addictions are common chronic psychiatric diseases that today are prevented and treated using relatively untargeted and only partially effective methods. The addictions are moderately to highly heritable, which is paradoxical because these disorders require use; a choice that is itself modulated by both genes and environment. The addictions are interrelated and related to other psychiatric diseases by common neurobiological pathways, including those that modulate reward, behavioural control and the anxiety or stress response. Our future understanding of addictions will be enhanced by the identification of genes that have a role in altered substance-specific vulnerabilities such as variation in drug metabolism or drug receptors and a role in shared vulnerabilities such as variation in reward or stress resiliency.
Comparison of Tracheobronchial Suction Catheters in Humans: Visualization by Fiberoptic Bronchoscopy

Tracheobronchial suctioning was performed in 20 patients undergoing diagnostic or therapeutic bronchoscopic examination. The effect of a single suctioning procedure on the airway mucosa was observed and recorded by still and cine photography through a fiberoptic bronchoscope. A variety of catheters of various designs were evaluated. All produced a negligible amount of trauma, and none was superior in efficiently evacuating mucus from the airways. Mucosal trauma with tracheobronchial suctioning procedures is more likely due to repetition, vigor, and amount of suction applied, regardless of which type of catheter is used.
Producer Protection Legislation and Termination Damages in the Presence of Contracting Frictions

This study models producer protection legislation (PPL) that would grant growers the right to claim damages if their contracts are prematurely terminated. In the absence of contracting frictions that prevent contractors from redesigning contracts to accommodate exogenous policy changes, producer protection legislation damages (PPLD) would not be distortionary or redistributive. If contracting frictions exist, then PPLD would have efficiency and redistributive effects, though the direction and magnitude depends on the size of PPL damages vis-a-vis expected damages under existing contract law. This study clarifies the conditions under which PPLD would decrease efficiency and protect growers.
Hypoxic conditions differentially regulate TAZ and YAP in cancer cells

The Hippo-YAP pathway is altered and implicated as an oncogenic signaling pathway in many human cancers. Hypoxia is an important microenvironmental factor that promotes tumorigenesis. However, the effects of hypoxia on the two most important Hippo-YAP effectors, YAP (Yes-associated protein) and TAZ (transcriptional co-activator with PDZ-binding motif), have not been reported. In this work, we demonstrated that TAZ was functionally involved in cell proliferation and/or migration in epithelial ovarian cancer (EOC) or human ovarian surface epithelial (HOSE) cells. Hypoxic conditions (1% O2 or hypoxia mimics) induced a reduction of YAP phosphorylation (S127) and total YAP expression in EOC cell lines OVCAR5 and SKOV3. However, these conditions up-regulated levels of S69 phosphorylated TAZ in EOC cells. The known TAZ kinases, Lats1 and Akt, were unlikely to be involved in up-regulated pTAZ by hypoxic conditions. Together, our data revealed new and differential regulating mechanisms of TAZ and YAP in cancer cells by hypoxia conditions.
Area postrema: chemoreceptor trigger zone for vomiting--is that all?

Publisher Summary This chapter discusses the role of area postrema (AP) as chemoreceptor trigger zone for vomiting. The area postrema of Retzius is the most caudal of the circumventricular organs in the brain. It is found that in all mammalian species, as well as in many other vertebrates, astride the opening of the spinal canal into the fourth ventricle. AP is one of an uncertain number of midline structures that are in contact with the cerebrospinal fluid and whose capillaries, like those in the choroid plexuses, are permeable to protein-bound vital dyes. The capillaries of AP are similar to those in choroid plexus in that they consist of a leaky fenestrated endothelium surrounded by a double basement membrane forming a perivascular space with which the capillary blood makes water and solute exchange. Pinocytotic vesicles are often found in the endothelial cells, and luminal microvilli have been observed in the capillaries. The peripapillary space is believed to represent an extension of the subarachnoid space, with the external basement membrane corresponding to the piamater. This arrangement should then permit direct chemical communication between blood and subarachnoid CSF.
Critical Flow Velocities for Collapse of Reactor Parallel-Plate Fuel Assemblies

Theoretical formulas are presented for prediction of the flow velocity at which collapse occurs in long parallelplate assemblies Beyond the critical velocity the pressure-unbalance forces developed as a consequence of a small deflection exceed the corresponding elastic restraining forces, and the plates collapse. Both flat- and curvedplate assemblies are considered, and the applicability of the formulas to design of reactor fuel-plate assemblies is discussed. (auth)
First signs for string breaking in two-flavor QCD

Abstract We have been examining the phenomenon of string breaking in QCD with two flavors of dynamical staggered quarks. We construct a transfer matrix from a combination of “string” and “two-meson” channels. Preliminary results with low statistics show the expected signs of string breaking.
A neuro-genetic approach to design and planning of a manufacturing cell

In this paper, we propose a neuro-genetic decision support system coupled with simulation to design a job shop manufacturing system by achieving predetermined values of targeted performance measures such as flow time, number of tardy jobs, total tardiness and machine utilization at each work center. When a manufacturing system is designed, the management has to make decisions on the availability of resources or capacity, in our setting, the number of identical machines in each work station and the dispatching rule to be utilized in the shop floor to achieve performance values desired. Four different priority rules are used as Earliest due date (EDD), Shortest Processing Time (SPT), Critical ratio (CR) and First Come First Serve (FCFS). In reaching the final decision, design alternatives obtained from the proposed system are evaluated in terms of performance measures. An illustrative example is provided to explain the procedure.
Solving 3 + 1 QCD on the transverse lattice using 1 + 1 conformal field theory

Abstract A new transverse lattice model of 3 + 1 Yang-Mills theory is constructed by introducing Wess-Zumino terms into the 2D unitary non-linear sigma model action for link fields on a 2D lattice. The Wess-Zumino terms permit one to solve the basic non-linear sigma model dynamics of each link, for discrete values of the bare QCD coupling constant, by applying the representation theory of non-abelian current (Kac-Moody) algebras. This construction eliminates the need to approximate the non-linear sigma model dynamics of each link with a linear sigma model theory, as in previous transverse lattice formulations. The non-perturbative behavior of the non-linear sigma model is preserved by this construction. While the new model is in principle solvable by a combination of conformal field theory, discrete light-cone, and lattice gauge theory techniques, it is more realistically suited for study with a Tamm-Dancoff truncation of excited states. In this context, it may serve as a useful framework for the study of non-perturbative phenomena in QCD via analytic techniques.
Phonon spectrum in a nanoparticle mechanically coupled to a substrate

Abstract We calculate the vibrational density-of-states in an insulating nanoparticle that is in weak mechanical contact with a semi-infinite substrate. The work is motivated by a recent experiment by Yang et al., where the low-energy phonon density-of-states of Y2O3 nanoparticles doped with Eu3+ was measured. Preliminary results presented here, based on the conventional quasiparticle-pole approximation for the phonon propagator, are in reasonable agreement with experiment.
On the Methylation of Carboxyl Groups with Methanesulfonyl Chloride in Pyridine

In a recent article Siddiqui et al. described a novel conversion of carboxylic acids to methyl esters,[1a] employing the reagent system methanesulfonyl chloride (MsCl) in pyridine at 0°C (Fig. 1).[...
An improved and facile preparation of SF5Br

Abstract A high yield and facile preparation of SF 5 Br is described. This preparation is carried out either at room temperature or with slight heating in a one-pot procedure.
Being specific about race-specific medicine.

ABSTRACT: Gary Puckrein's paper “BiDil: From Another Vantage Point” misrepresents rather than refutes our previously published analysis of BiDil. Puckrein claims that if our analysis were to prevai...
Effective interaction Hamiltonian of polaron pairs in diluted magnetic semiconductors

The magnetic interaction of a pair of bound magnetic polarons in diluted magnetic semiconductors is analyzed via a generalized Hubbard-type Hamiltonian for two carriers in the presence of effective magnetic fields arising from the magnetic polarization of their respective polarons. For the case where the magnetic fields at the two sites have equal magnitude but are allowed to have arbitrary directions, it is shown that the energy of the two polarons is minimized for a ferromagnetic configuration of the carrier spins (in contrast to the case of hydrogenic centers in nonmagnetic semiconductors) if polaron fields are strong enough. A modified Heisenberg-type Hamiltonian is constructed to describe the low energy states of the resulting system.
HQET and exclusive B-decays

Abstract Exclusive semileptonic B-decays are discussed. The emphasis is on using semileptonic decays to determine | V ub | and | V cb |. Recent progress in our understanding of B semileptonic decays to excited charmed mesons is also reviewed.
Positivity of the universal pairing in 3 dimensions

Associated to a closed, oriented surface S is the complex vector space with basis the set of all compact, oriented 3-manifolds which it bounds. Gluing along S defines a Hermitian pairing on this space with values in the complex vector space with basis all closed, oriented 3-manifolds. The main result in this paper is that this pairing is positive, i.e. that the result of pairing a nonzero vector with itself is nonzero. This has bearing on the question of what kinds of topological information can be extracted in principle from unitary (2+1)-dimensional TQFTs. The proof involves the construction of a suitable complexity function c on all closed 3-manifolds, satisfying a gluing axiom which we call the topological Cauchy-Schwarz inequality, namely that c(AB) ≤max(c(AA),c(BB)) for all A,B which bound S, with equality if and only if A=B. The complexity function c involves input from many aspects of 3-manifold topology, and in the process of establishing its key properties we obtain a number of results of independent interest. For example, we show that when two finite-volume hyperbolic 3-manifolds are glued along an incompressible acylindrical surface, the resulting hyperbolic 3-manifold has minimal volume only when the gluing can be done along a totally geodesic surface; this generalizes a similar theorem for closed hyperbolic 3-manifolds due to Agol-Storm-Thurston.
Intertemporal female labor force behavior in a developing country: what can we learn from a limited panel? ☆

Abstract We analyze intertemporal labor market behavior of women in urban Guinea, West Africa using two distinct methodologies applicable to a short (2-year) panel. A multi-period multinomial logit model with random effects provides evidence of unobserved individual heterogeneity as a factor strongly affecting labor market sector choices over time. Results from simpler single period models that condition on prior sector choices are consistent with either heterogeneity or state dependence. Both approaches perform equally well in predicting individual labor market behavior conditional on past choices. In terms of observable characteristics, the estimates confirm the heterogeneous structure of the urban labor market: informal and formal employment appear to differ significantly in terms of skill requirements, compatibility with child care, and costs of entry.