cssi/SciSciGPT-SciSciNet huggingface dataset:
Extracellular matrix modifications at fertilization: regulation of dityrosine crosslinking by transamidation

Fertilization is accompanied by the construction of an extracellular matrix that protects the new zygote. In sea urchins, this structure is built from glycoproteins residing at the egg surface and in secretory vesicles at the egg cortex. Four enzymatic activities are required for the transformation of these proteins into the mechanically and chemically resilient fertilization envelope: proteolysis, transamidation, NADPH-dependent oxidation and peroxidation. Here, we identify the Strongylocentrotus purpuratus enzymes responsible for the formation of e(γ-glutamyl)lysine crosslinks (transamidation). We find that these two transglutaminases are activated by local acidification and act on specific substrates within the fertilization envelope (including ovoperoxidase, rendezvin and SFE9). Surprisingly, these enzymes also regulate dityrosine crosslinking both by direct conjugation of ovoperoxidase and by modulating hydrogen peroxide production. Together, these results emphasize how transglutaminases can coordinate the activities of other enzymes during extracellular matrix transmogrifications.
Pass-through of Exchange Rates and Competition Between Floaters and Fixers

This paper studies how a rise in the share of U.S. imports from China, or any country with a fixed exchange rate, could disproportionately lower pass-through of exchange rates to U.S. import prices. We develop a theoretical model showing how changes in the competitive environment induce exporters from other countries to lower markups in response to a dollar depreciation, thereby moderating pass-through. The model indicates that a particular ‘local bias’ condition is necessary for this effect, and that free entry amplifies it. The model also produces an approximately log-linear structural equation for pass-through regressions including the China share. Panel regressions over 1993–2006 indicate that the rising share of trade from China, or from all countries with fixed exchange rates, can explain a decline in pass-through by about onefifth of its size.
Free radical cyclizations of terminal alkynes with oxime ethers

Abstract A benzyl oxime ether tethered to a terminal alkyne efficiently undergoes a free radical hydrostannylation reaction to afford five- and six-membered rings bearing a protected amine and a vinyl stannane functionality. These products were subsequently protiodestannylated to obtain the unsubstituted exo-methylene compounds.
Scattering from a cylindrically conformal slotted waveguide array antenna

A numerical method is developed to investigate electromagnetic scattering by a cylindrically conformal waveguide-fed slot array. The problem is first formulated in terms of integral equations using the equivalence principle. The integral equations are then solved using the method of moments (MoM) in conjunction with global sinusoidal basis functions and Galerkin's testing procedure. The MoM solution requires the evaluation of the generalized admittance matrices involving various dyadic Green's functions. The slow convergence of the series associated with the summation of waveguide modes is accelerated using the Kummer transformation and the slow convergence of the series associated with the summation of the exterior modes is avoided by using the asymptotic solutions with proper treatment for singular integrals. The evaluation of the excitation vector and scattered field is also accelerated using Watson's transformation and asymptotic solutions. Numerical results are presented to illustrate the scattering characteristics of the cylindrically conformal waveguide-fed slot arrays, such as the effects of curvature, slot thickness, and waveguide termination on the radar cross section (RCS) of the arrays.
Radar estimates of aboveground biomass in boreal forests of interior Alaska

Airborne SAR data gathered by the NASA/JPL three-frequency, polarimetric, radar system in winter, spring, and summer over the Bonanza Creek Experimental Forest, near Fairbanks, AK, are compared to estimates of whole-tree aboveground dry biomass from 21 forest stands and two clear-cuts. While C-band radar backscatter shows little sensitivity to biomass, L- and P-band radar backscatter increase by more than 6 dB when biomass increases from 5 to 200 tons/ha. Using second-order polynomial regressions, biomass values are predicted from the radar at L- and P-band and compared to actual biomass values. At P-band HV-polarization, the error in predicted biomass is about 30% of the actual biomass. When HV-, HH-, and VV-polarization are used together in the regression, the error in predicted biomass is about 20%. Errors obtained using L-band data are a few percents larger. These errors are caused by uncertainties in actual stand biomass estimates, significant inner-stand spatial variations in biomass, unusual conditions of forest stands following natural disturbances, along with interactions of the radar signals with a complex three-dimensional structure of the canopy. Multiple incidence angle data reveal that the incidence angle /spl theta//sub i/ of the radar illumination is also a factor influencing the retrieval of biomass, even at HV-polarization, when /spl theta//sub i/>50/spl deg/ or /spl theta//sub i/ >
Potential Impact of the Eurasian Boreal Forest on North Pacific Climate Variability

The authors demonstrate that variability in vegetation cover can potentially influence oceanic variability through the atmospheric bridge. Experiments aimed at isolating the impact of variability in forest cover along the poleward side of the Asian boreal forest on North Pacific SSTs are performed using the fully coupled model, Fast Ocean Atmosphere Model–Lund Potsdam Jena (FOAM-LPJ), with dynamic atmosphere, ocean, and vegetation. The northern edge of the simulated Asian boreal forest is characterized by substantial variability in annual forest cover, with an east–west dipole pattern marking its first EOF mode. Simulations in which vegetation cover is allowed to vary over north/central Russia exhibit statistically significant greater SST variance over the Kuroshio Extension. Anomalously high forest cover over North Asia supports a lower surface albedo with higher temperatures and lower sea level pressure, leading to a reduction in cold advection into northern China and in turn a decrease in cold air transport into the Kuroshio Extension region. Variability in the large-scale circulation pattern is indirectly impacted by the aforementioned vegetation feedback, including the enhancement in upper-level jet wind variability along the north–south flanks of the East Asian jet stream.
Camina pairs that are not p-closed

We show for every prime p that there exists a Camina pair (G, N), where N is a p-group and G is not p-closed.
A geometric crescent model for black hole images

The Event Horizon Telescope (EHT), a global very long baseline interferometry array operating at millimetre wavelengths, is spatially resolving the immediate environments of black holes for the first time. The current observations of the Galactic center black hole, Sagittarius A* (Sgr A*), and M87 have been interpreted in terms of either geometric models (e.g., a symmetric Gaussian) or detailed calculations of the appearance of black hole accretion flows. The former are not physically motivated, while the latter are subject to large systematic uncertainties. Motivated by the dominant relativistic effects of Doppler beaming and gravitational lensing in many calculations, we propose a geometric crescent model for black hole images. We show that this simple model provides an excellent statistical description of the existing EHT data of Sgr A* and M87, superior to other geometric models for Sgr A*. It also qualitatively matches physically predicted models, bridging accretion theory and observation. Based on our results, we make predictions for the detectability of the black hole shadow, a signature of strong gravity, in future observations.
Rational choice, Round Robin, and rebellion: An institutional solution to the problems of revolution

Abstract Two collective action problems plague successful revolution. On the one hand, would-be revolutionaries confront a “participation problem,” whereby no rationally self-interested individual has an incentive to participate in rebellion. On the other hand, individuals face a “first-mover problem” whereby no rationally self-interested individual has an incentive to lead rebellion. This paper argues that 18th-century merchant sailors who confronted these problems devised a novel institution to facilitate maritime revolution and assist them in overthrowing abusive captains. This institution was called a “Round Robin.” Round Robins helped overcome both the participation and first-mover problems by aligning the interests of individual sailors desiring mutiny and restructuring the payoffs of leading versus following maritime rebellion.
Polyfluoroether derivatives via nucleophilic fluorination of glyoxal hydrates with deoxofluor.

Various glyoxal hydrates have been reacted with Deoxofluor [(CH3OCH2CH2)2NSF3]. In concentrated solutions of dichloromethane, Deoxofluor (1) efficiently fluorinates a variety of glyoxal hydrates, RCOCHO·H2O (R = 4-methoxyphenyl, 3,4-methylenedioxyphenyl, 4-methylphenyl, 4-fluorophenyl, phenyl, 2-thienyl, methyl) (6a−g) to form polyfluoroethers 7a−g and 8a−g as meso and racemic mixtures (∼1:1) in good yields. The meso and racemic compounds were separated by flash chromatography and characterized. When the reactant comprised two different glyoxal hydrates, mixed polyfluoroethers (9h−j) were observed as the major products. The yields of the mixed polyfluoroethers depend on the ratio of the two different glyoxal hydrates used. Reactions of some other hydrates, such as hydrindantin dihydrate (10) and 1,1,1,5,5,5-hexafluoro-2,2,4,4-pentanetetrol (11), were also studied with Deoxofluor to give a cyclic polyfluoroether (12) and β-ketoamine (13), respectively. When the reactions of 6a−d were carried out under very...
Protein Phosphatase Type 1, The Product of the Retinoblastoma Susceptibility Gene, And Cell Cycle Control

Cell cycle regulation—three words which conjure in the minds of those conducting research in this area a myriad of proteins and biochemical pathways. In this examination, an overview of the mammalian cell cycle is presented with emphasis on the function of the negative growth regulatory protein, the product of the retinoblastoma susceptibility gene, pRb. Since the activity of this protein itself is regulated by phosphorylation on serine and threonine residues, more elaborate discussions on the enzymes involved in placing the phosphates on, and taking them off, are provided. The focus here is on the activity of the members of the type 1 class of serine/threonine phosphatases. More specifically, the role of PP1 in regulating cell cycle progression by dephosphorylating pRb during mitosis, thereby activating the growth suppressing function of pRb, is presented. Suggested avenues for further investigation regarding the functional significance, and ultimately the effect on cell cycle progression, of the complex...
New Measurements of Phase Velocity at VLF

The purpose of this note is to describe some new phase velocity measurements using signals from the VLF stations NPG (18.6 kc/s) near Seattle, Wash., and WWVL (20.0 kc/s) near Fort Collins, Colo. Previous experimental results have been described by Wait [1961].
Genetic ablation of neural crest cell diversification.

The neural crest generates multiple cell types during embryogenesis but the mechanisms regulating neural crest cell diversification are incompletely understood. Previous studies using mutant zebrafish indicated that foxd3 and tfap2a function early and differentially in the development of neural crest sublineages. Here, we show that the simultaneous loss of foxd3 and tfap2a function in zebrafish foxd3 zdf10 ; tfap2a low double mutant embryos globally prevents the specification of developmentally distinct neural crest sublineages. By contrast, neural crest induction occurs independently of foxd3 and tfap2a function. We show that the failure of neural crest cell diversification in double mutants is accompanied by the absence of neural crest sox10 and sox9a/b gene expression, and that forced expression of sox10 and sox9a/b differentially rescues neural crest sublineage specification and derivative differentiation. These results demonstrate the functional necessity for foxd3 and tfap2a for neural crest sublineage specification and that this requirement is mediated by the synergistic regulation of the expression of SoxE family genes. Our results identify a genetic regulatory pathway functionally discrete from the process of neural crest induction that is required for the initiation of neural crest cell diversification during embryonic development.
reaction of amines with n1,n10-ethylene-bridged flavinium salts: the first nmr spectroscopic evidence of c10a tetrahedral amine adducts.

Abstract Two different 13C-labeled 7-trifluoromethyl-N1,N10-ethyleneisoalloxazinium chlorides were utilized to examine the mechanism of amine dehydrogenation. 1H NMR studies in CD3CN (13C NMR in DMSO-d6), as confirmed using 15N-labeled benzylamine, indicate that primary and secondary amines add to give tetrahedral C10a adducts that persist for hours at 25°C. Upon heating, the C10a amine adducts partition between rearrangement to C4a spirohydantoin amidines, and, in the case of benzylic amines, β-elimination to give reduced flavin and imine dehydrogenation product. A C10a tetrahedral hydroxy adduct, generated under basic conditions when water was present, was also confirmed by 1H/13C NMR.
MyAnMAr: Cross-CuttinG GovernAnCe ChAllenGes

Since 2010, Myanmar has been in the midst of a multifaceted transition, involving economic reforms, the resolution of multiple longstanding civil confl icts, and a nascent transition to democratic rule. Th ese transitions are coinciding with a resource-led economic boom. We assess the current status of governance institutions, as well as their performance in comparison to ASEAN and selected other countries. Specifi cally we discuss outstanding problem areas related to economic governance, particularly in the legal system, the business regulatory framework, and in bureaucratic capacity, as well as the potential use of external policy anchors, particularly in the Extractive Industries Transparency Initiative (EITI) process, to strengthen Myanmar’s ongoing reform eff ort. JEL: N45, P28, D72, D73
Combined Structural and Manufacturing Optimization of Stiffened Composite Panels

Manufacturing considerations have been incorporated into the design optimization of a blade-stiffened composite panel. For the manufacturing analysis, a one-dimensional resin film infusion model is developed to compute the infiltration time of the resin into a fabric preform of the panel. Results are presented showing the effects of design variables that are important for structural performance, such as crosssectional geometry variables and material properties, on the panel manufacturing effort. In addition, the effects of manufacturing process variables, such as pressure and temperature, on the structural performance are studied. The structural problem is formulated to minimize the panel mass subject to buckling constraints. A simplified buckling analysis model for the panel is used to compute the critical buckling loads. The objective of the manufacturing problem is to minimize the resin infiltration time. Optimum panel designs for the manufacturing and structures problems alone, as well as for the combined problem, are generated using a genetic algorithm. The results indicate a strong connection between the structural and manufacturing design variables and tradeoffs between the two responses, and illustrate that a multidisciplinary approach to the problem is essential to incorporate manufacturing into the preliminary design stage.
Thought and Behavior Contagion in Capital Markets

others only through market price, information transmission and processing is simple (without thoughts and feelings), and there is no localization in the influence of an investor on others. In reality, individuals often process verbal arguments obtained in conversation or from media presentations, and observe the behavior of others. We review here evidence concerning how these activities cause beliefs and behaviors to spread, aect financial decisions, and aect market prices; and theoretical models of social influence and its eects on capital markets. Social influence is central to how information and investor sentiment are transmitted, so thought and behavior contagion should be incorporated into the theory of capital markets.
Aircraft Navigation with the Limited Operational Phase of the NAVSTAR Global Positioning System

The navstar Global Positioning System (GPS) will soon be in the limited operational phase. During this phase, a GPS user will not generally be able to determine his position using satellite measurements only. This paper describes the simulation of an aircraft navigation technique which uses the limited operational phase GPS and barometric altimeter measurements. For this research effort, the GPS user was assumed to be a cargo–type aircraft equipped with a single–frequency, sequentially–tracking GPS receiver and a barometric altimeter. The flight profile consisted of a New York to Chicago flight and included takeoff and landing maneuvers. A small amount of wind gusts were simulated. To make the simulation more realistic, random effects were included in the user and satellite clocks, in the atmospheric radio delays, and in the measurement process itself. The tested navigation algorithm is based on the well-known Kalman filter equations. Three different models of aircraft acceleration were evaluated. Results indicate that, for a wide range of filter parameters, navigation errors are generally less than 100 meters. Poor geometry, however, results in kilometer–sized position errors.
MoCCA: A mobile cellular cloud architecture

This paper presents MoCCA — a cellular cloud architecture for building mobile clouds using small-footprint micro-servers running on cell phones. We provide details of this architecture which is based on GSM standard, discuss several challenges, and include performance results to validate the assumptions that a mobile cellular cloud can indeed be in the realm of possibilities.
FORCED OSCILLATIONS OF NONSPHERICAL BUBBLES

The oscillation of a gas bubble in liquid under externally applied sinusoidal pressure field is studied. When the applied pressure amplitude is small and the forcing frequency is not in the neighborhood of the resonance frequency of the bubble, the familiar linear results are obtained. When the applied amplitude is not small, there is a tendency to generate both the subharmonic oscillations of the spherical mode and the surface waves on the bubble. The theoretical study is carried out by using both the normal mode analysis and the variational method. It is found that the variational method can lead to approximate solutions in a simpler way than other conventional methods. Experimental implication of the theoretical results is also discussed.
Architecture of virtual machines

In this paper we develop a model which represents the addressing of resources by processes executing on a virtual machine. The model distinguishes two maps: the o-map which represents the map visible to the operating system software running on the virtual machine, and the f-map which is invisible to that software but which is manipulated by the virtual machine monitor running on the real machine. The o-map maps process names into resource names and the f-map maps virtual resource names into real resource names. Thus, a process running on a virtual machine addresses its resources under the composed map f o o. In recursive operation, f maps from one virtual machine level to another and we have f o f o ... o f o o.The model is used to describe and characterize previous virtual machine designs. We also introduce and illustrate a general approach for implementing virtual machines which follows directly from the model. This design, the Hardware Virtualizer, handles all process exceptions directly within the executing virtual machine without software intervention. All resource faults (VM-faults) generated by a virtual machine are directed to the appropriate virtual machine monitor without the knowledge of processes on the virtual machine (regardless of the level of recursion).
Marriage, Specialization, and the Gender Division of Labor

We consider why the gender division of labor is so often enforced by custom and why customary gender divisions of labor generally involve both direction and prohibition. In our formal model, agents first learn skills and then enter the marriage market. We show that wasteful behavior may emerge due to strategic incentives in specialization choice and human capital acquisition and that both problems may be mitigated through a customary gender division of labor. This division is not Pareto improving. Both the distributional effects and welfare gains of a customary gender division of labor decrease as opportunities for market exchange increase.
A Novel Method for Combining Algebraic Decoding and Iterative Processing

We propose novel error correction coding schemes called Generalized Integrated Interleaving and Sparsely Integrated Interleaving codes. In the context of block interleaved codewords, Generalized Integrated Interleaving allows nonuniform redundancy to be shared among all the interleaves. This allows the redundancy to be adjusted on-the-fly to better suit the error statistics of the channel or storage device. Sparsely Integrated Interleaving groups data nodes in a distributed storage system into subgroups. A data node can belong to several subgroups. Small errors are corrected locally within each subgroup. A localized algebraic iterative decoding algorithm is used to decode across subgroups to correct large errors that cannot be corrected within subgroups. Very little correction capability is sacrificed to achieve fast error correction and lower communication overhead. This scheme improves data access for all the data nodes and allows easy scaling of the distributed storage network.
Momentum and Reversals in Equity‐Index Returns During Periods of Abnormal Turnover and Return Dispersion

We document new patterns in the dynamics between stock returns and trading volume. Speci¢cally, we ¢nd substantial momentum (reversals) in consecutive weekly returns when the latter week has unexpectedly high (low) turnover. This pattern is evident in equity indices, index futures, and individual stocks. Similarly, we also ¢nd that the autocorrelation in equity-index returns is increasing with the unexpected dispersion across the latter week’s ¢rm-level returns. Weeks with extreme turnover and dispersion shocks (both high and low) tend to have more macroeconomic news releases. Our ¢ndings bear on understanding price formation and the economic interpretation of turnover and dispersion shocks. IN THIS PAPER, we document new patterns in the dynamics between stock returns and trading volume. Speci¢cally, we ¢nd substantial momentum in consecutive weekly stock returns when the latter week has abnormally high turnover. 1 Conversely, we ¢nd substantial reversals in consecutive weekly returns when the latter week has abnormally low turnover. By abnormal turnover, we mean the shock in the turnover time series after controlling for its autoregressive properties and for normal movements with the market return. 2 We ¢nd this return pattern in equity indices, index futures, individual stocks, and in the U.S., Japan, and U.K. stock markets.
Bioinspired hydrogen bond motifs in ligand design: the role of noncovalent interactions in metal ion mediated activation of dioxygen.

Hydrogen bonds influence secondary coordination spheres around metal ions in many proteins. To duplicate these features of molecular architecture in synthetic systems, urea-based ligands have have been developed that create rigid organic frameworks when bonded to metal ions. These frameworks position hydro-gen bond donors proximal to metal ion(s) to form specific chem-ical microenvironments. Iron(II) and manganese(II) complexes with constrained cavities activate O2, yielding MIII (MIII = Fe and Mn) complexes with terminal oxo ligands. Installation of anionic sites within the cavity assists the formation of complexes with MII/III−OH and MIII−O units derived directly from water. Opening the cavity promotes M(μ-O)2M rhombs, as illustrated by isolation of a cobalt(III) analogue, the stability of which is promoted by the hydrogen bonds surrounding the bridging oxo ligands.
Palladium-Catalyzed Allylic Alkylation of Carboxylic Acid Derivatives: N-Acyloxazolinones as Ester Enolate Equivalents

A general asymmetric allylic alkylation of ester enolate equivalents at the carboxylic acid oxidation state is reported. N-Acylbenzoxazolinone-derived enol carbonates are synthesized in good yield and employed in the palladium-catalyzed alkylation reaction. Good yields (up to 99%) and enantioselectivities (up to 99% ee) are obtained and the imide products are readily converted to a series of carboxylic acid derivatives without loss of enantiopurity. High enantioselectivity in the reaction is achieved by a new strategy for ligand design involving variation of the steric properties of the diarylphosphine moiety.
Capacitor Calibration by Step-Up Methods

Summary--Step-calibration methods are used in many physical laboratories for the extension of measurements to quantities far removed from the magnitude of greatest accuracy at which absolute determinations are made. The excellent precision of repetitive substitution procedures is exploited by step-up or step-down methods to extend measurements to higher or lower magnitudes without serious degradation of accuracy. The application of step-up techniques to the calibration of variable air capacitors is described in this paper as a practical example of the method.
Dynamic Crystals: Visually Detected Mechanochemical Changes in the Luminescence of Gold and Other Transition‐Metal Complexes

Back to the grindstone: Certain crystalline complexes of gold, platinum, and vanadium undergo dramatic changes in their luminescence or their color upon grinding. The picture shows the transformation of colorless crystals of [(F(5)C(6)Au)(2)(mu-1,4-CN(2)C(6)H(4))] powder from a blue-emitting form (lambda(max) = 415 nm) to a yellow/green-emitting form (lambda(max) = 533 nm) on grinding with a pestle. The process is reversible.
Uniform Uniform Exponential Growth of Subgroups of the Mapping Class Group

Let Mod(S) denote the mapping class group of a compact, orientable surface S. We prove that finitely generated subgroups of Mod(S) which are not virtually abelian have uniform exponential growth with minimal growth rate bounded below by a constant depending only, and necessarily, on S. For the proof, we find in any such subgroup explicit free group generators which are “short” in any word metric. Besides bounding growth, this allows a bound on the return probability of simple random walks.
An interface between continuous and discrete-event controllers for vehicle automation

The work presented is part of a bigger effort to design an automated highway system (AHS) to improve the capacity and safety of current highways. Automation of highways and, in particular, platooning of vehicles raise a number of control issues. In the design proposed by Varaiya,(see IEEE Trans. Automat., Contr., vol.38, no.2, p.195-207, 1993), these issues are addressed by a hierarchical structure consisting of both discrete-event and continuous controllers. Our work is an attempt to construct a consistent interface between these two types of controllers. The proposed design is in the form of a set of finite-state machines (FSMs) that interact with the discrete controllers through discrete commands and with the continuous controllers by issuing commands that get translated to inputs for the vehicle actuators. The operation of the proposed design is verified using COSPAN and tested in simulation. The interface design provides insight into interesting problems related to the hybrid nature of the AHS as it touches on both the discrete and continuous worlds.
Thermohaline Circulation Stability: A Box Model Study. Part I: Uncoupled Model

A thorough analysis of the stability of the uncoupled Rooth interhemispheric three-box model of thermohaline circulation (THC) is presented. The model consists of a northern high-latitude box, a tropical box, and a southern high-latitude box, which correspond to the northern, tropical, and southern Atlantic Ocean, respectively. Restoring boundary conditions are adopted for the temperature variables, and flux boundary conditions are adopted for the salinity variables. This paper examines how the strength of THC changes when the system undergoes forcings that are analogous to those of global warming conditions by applying the equilibrium state perturbations to the moisture and heat fluxes into the three boxes. In each class of experiments, using suitably defined metrics, the authors determine the boundary dividing the set of forcing scenarios that lead the system to equilibria characterized by a THC pattern similar to the present one from those that drive the system to equilibria with a reversed THC. Fast increases in the moisture flux into the northern high-latitude box are more effective than slow increases in leading the THC to a breakdown, while the increases of moisture flux into the southern high-latitude box strongly inhibit the breakdown and can prevent it, as in the case of slow increases in the Northern Hemisphere. High rates of heat flux increase in the Northern Hemisphere destabilize the system more effectively than low ones; increases in the heat fluxes in the Southern Hemisphere tend to stabilize the system.
Averaging algorithms and distributed anonymous discrete function computation

In distributed consensus and averaging algorithms, processors exchange and update certain values (“estimates” or “opinions”) by forming a local average with the values of their neighbors. Under suitable conditions, such algorithms converge to consensus (every processor ends up holding the same value) or even average-consensus (consensus is achieved on the average of the initial values held by the processors). We first review some convergence rate results. We then abstract the problem by introducing a model of deterministic distributed function computation by a network of identical and anonymous nodes, with limited communication and storage capabilities, and where each node only knows its neighbors, not the entire graph. Our goal is to characterize the class of functions that can be computed within this model. In our main result, we provide a necessary condition for computability which we show to be nearly sufficient, in the sense that every function that satisfies this condition can at least be approximated. The problem of computing (suitably rounded) averages in a distributed manner plays a central role in our development, and we provide an algorithm that solves it in time that grows at most quadratically with the size of the network. (Joint work with J. Hendrickx and A. Olshevsky.)
PIRATES OF THE CARIBBEAN: SEIU'S FAILED BID IN PUERTO RICO

In October of 2008, the Service Employees International Union (SEIU) failed to obtain majority support to represent a 40,000-member bargaining unit of public school teachers in Puerto Rico even though it had most of the odds stacked in its favor: a huge war chest, a decertified and bankrupt rival, and the Puerto Rican government qua employer's neutrality, if not outright support. The Federacion de Maestros de Puerto Rico, the SEIU's rival, campaigned against the SEIU's bid for exclusive representation by focusing on rank-and-file mobilization and a message against raiding by a “colonial” union. The event showed that even progressive and successful unions such as the SEIU are not immune to oligarchic tendencies and may raid other unions in pursuit of money and power. Strategies that combine more democratic, bottom-up mobilization, including, in the case of Puerto Rico, strengthening the long-established tradition of minority unionism, could dampen future oligarchic tendencies, buttress industrial democracy, and create better coexistence between trade union organizations. To move forward, especially given the global crisis that has befallen us, unions need to start acting in the most principled of ways and expressing solidarity in the deepest manners.
Efficient Glycosidation of a Phenyl Thiosialoside Donor with Diphenyl Sulfoxide and Triflic Anhydride in Dichloromethane

The formation of sialic acid glycosides with a thiosialic acid derivative, diphenyl sulfoxide, and trifluoromethanesulfonic anhydride is reported. With an excess of diphenyl sulfoxide, glycal formation can be completely suppressed and excellent yields are obtained for coupling to a wide range of primary, secondary, and tertiary acceptors.
Investor Inattention and the Market Impact of Summary Statistics

We show that U.S. stock and Treasury futures prices respond sharply to recurring stale information releases. In particular, we identify a unique macroeconomic series---the U.S. Leading Economic Index® (LEI)---which is released monthly and constructed as a summary statistic of previously released inputs. We show that a front-running strategy that trades S&P 500 futures in the direction of the announcement a day before its release and then trades in the opposite direction of the announcement following its release generates an average annual return of close to 8%. These patterns are more pronounced for high beta stocks, for stocks that are more difficult to arbitrage, and during times when investors' sensitivity to firm-specific stale information is high. Treasury futures exhibit similar, albeit less pronounced, price patterns. Other measures of information arrival, such as price volatility and volume, spike following the release. These empirical findings suggest that some investors are inattentive to the stale nature of the information included in the LEI releases, instead interpreting it as new information, and thereby causing temporary yet significant mispricing. This paper was accepted by Brad Barber, Teck Ho, and Terrance Odean, special issue editors.
VARIABILITY OF NARROW, ASSOCIATED ABSORPTION LINES IN MODERATE- AND LOW-REDSHIFT QUASARS

We present the results of a search for variability in the equivalent widths (EWs) of narrow, associated (jv j� 5000 km s � 1 ) absorption lines found in the UV spectra of z � 1:5 quasars. The goal of this search was to use variability as a means of identifying absorption lines arising in gas that is intrinsic to the quasar central engine. We have compared archival Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra of quasars with recent spectra obtained as part of our own snapshot survey of the same objects with the Space Telescope Imaging Spectrograph (STIS). The intervals between observations are 4-10 yr. We primarily focused on the C iv absorption lines, although we also studied other lines available in the same spectra (e.g., Ly� ,N v ,O vi). Our main result is that 4 out of 15 quasars, or 4 out of 19 associated absorption systems, contained variable narrow absorption lines, which are indicative of intrinsic absorption. We conclude that a minimum of 21% of the associated absorption-line systems are variable. Because not all systems will have necessarily varied, this is a lower limit on this fraction and is consistent with previous estimates based on variability, partial coverage analysis, or statistical arguments. If we interpret the upper limits on the variability timescale as upper limits on the recombination time of the absorber, we constrain the density of the absorber to be ne >3000 cm � 3 and its distance from the ionizing source to be R P100 pc. Moreover, we are now able to pick out specific intrinsic absorption-line systems to be followed up with high-dispersion spectroscopy in order to constrain the geometry, location, and physical conditions of the absorber. We briefly illustrate how follow-up studies can yield such constraints by means of a simulation.
Machine Learning Techniques for Prediction of Early Childhood Obesity.

Objectives: This paper aims to predict childhood obesity after age two, using only data collected prior to the second birthday by a clinical decision support system called CHICA. Methods: Analyses of six different machine learning methods: RandomTree, RandomForest, J48, ID3, Naive Bayes, and Bayes trained on CHICA data show that an accurate, sensitive model can be created. Results: Of the methods analyzed, the ID3 model trained on the CHICA dataset proved the best overall performance with accuracy of 85% and sensitivity of 89%. Additionally, the ID3 model had a positive predictive value of 84% and a negative predictive value of 88%. The structure of the tree also gives insight into the strongest predictors of future obesity in children. Many of the strongest predictors seen in the ID3 modeling of the CHICA dataset have been independently validated in the literature as correlated with obesity, thereby supporting the validity of the model. Conclusions: This study demonstrated that data from a production clinical decision support system can be used to build an accurate machine learning model to predict obesity in children after age two.
Limited angle reconstruction using stabilized algorithms

The stability of solutions to the limited-angle tomography reconstruction problem obtained by using the projections-onto-convex-sets (POCS) technique are examined. Although POCS techniques provide a feasible solution to the reconstruction problem, the solution is only one sample from the intersection of the closed convex sets that define the solution space. A method for evaluating the ensemble of possible solution waveforms that are in the neighborhood of a solution is presented. The ensemble characteristics are used to construct an inverse filter which is then applied to the computed solution. The results obtained using this method are less sensitive to noise amplification and are less dependent on both starting data and the number of iterations. An estimate of the object-dependent extrapolation that is possible using either linear or nonlinear constraints is provided. >
The electrothermal ramjet

An electrothermal ramjet configuration is examined as a possible alternative to rail guns and mass drivers for high acceleration launch missions. For a specific mission (Earth escape), the idealized performance of electrothermal ramjet, electrothermal rocket and electromagnetic acceleration systems are compared. This comparison indicates that the gross performance of the ramjet compares favorably with that of the ideal electromagnetic acceleration system. A specific configuration for the ramjet is chosen, and models for the dynamics, thermodynamics, and fluid mechanics are presented. Results of calculations for a typical supersonic launch cycle suggest that pressure, temperature, and power demand profiles associated with ramjet operation should be reasonable. A light gas gun is proposed to accelerate the vehicle to the critical velocity where efficient ramjet operation can begin. At high velocities the theoretical performance of the ramjet is also shown to be substantially better than that of the light gas gun.
Critical interfaces in organic solar cells and their influence on the open-circuit voltage.

Organic photovoltaics, which convert sunlight into electricity with thin films of organic semiconductors, have been the subject of active research over the past 20 years. The global energy challenge has greatly increased interest in this technology in recent years. Low-temperature processing of organic small molecules from the vapor phase or of polymers from solution can confer organic semiconductors with a critical advantage over inorganic photovoltaic materials since the high-temperature processing requirements of the latter limit the range of substrates on which they can be deposited. Unfortunately, despite significant advances, the power conversion efficiency of organic solar cells remains low, with maximum values in the range of 6%. A better understanding of the physical processes that determine the efficiency of organic photovoltaic cells is crucial to enhancing their competitiveness with other thin-film technologies. Maximum values for the photocurrent can be estimated from the light-harvesting cap...
Minimal Riesz Energy Point Configurations for Rectifiable d-Dimensional Manifolds

We investigate the energy of arrangements of N points on a rectifiable d-dimensional manifold A R d 0 that interact through the power law (Riesz) potential V = 1/r s , where s > 0 and r is Euclidean distance in R d 0 . With Es(A,N) denoting the minimal energy for such N-point configurations, we determine the asymptotic behavior (as N ! 1) of Es(A,N) for each fixed s d. Moreover, if A has positive d-dimensional Hausdor measure, we show that N-point configurations on A that minimize the s-energy are asymptotically uniformly distributed with respect to d-dimensional Hausdor measure on A when s d. Even for the unit sphere S d R d+1 , these results are new.
Satellite altimeter measurements of surface wind

Geophysical model functions (GMFs) for altimeter wind speed measurements are described. These GMFs account for an effect of the actual degree of sea development on the radar cross section by utilizing information on the significant wave height. The wind speed measurement accuracy achieved (the overall bias 0.1 m/s and the rms error about 1.6 m/s) is higher than the accuracy of commonly employed GMFs while the wave-age-related trend is reduced to a geophysically insignificant level. >
Large-scale visual data analysis

Summary form only give, as follows. Modern high performance computers have speeds measured in petaflops and handle data set sizes measured in terabytes and petabytes. Although these machines offer enormous potential for solving very large-scale realistic computational problems, their effectiveness will hinge upon the ability of human experts to interact with their simulation results and extract useful information. One of the greatest scientific challenges of the 21st century is to effectively understand and make use of the vast amount of information being produced. Visual data analysis will be among our most important tools in helping to understand such large-scale information. Our research at the Scientific Computing and Imaging (SCI) Institute at the University of Utah has focused on innovative, scalable techniques for large-scale 3D visual data analysis. In this talk, I will present state-of-the-art visualization techniques, including scalable visualization algorithms and software, cluster-based visualization methods and innovative visualization techniques applied to problems in computational science, engineering, and medicine. I will conclude with an outline for future high performance visualization research challenges and opportunities.
Diffusion of Behavior and Equilibrium Properties in Network Games

Situations in which agents’ choices depend on choices of those in close proximity, be it social or geographic, are ubiquitous. Selecting a new computer platform, signing a political petition, or even catching the flu are examples in which social interactions have a significant role. While some behaviors or states propagate and explode within the population (e.g., Windows OS, the HIV virus) others do not (e.g., certain computer viruses). Our goal in this paper is twofold. First, we provide a general dynamic model in which agents’ choices depend on the underlying social network of connections. Second, we show the usefulness of the model in determining when a given behavior expands within a population or disappears as a function of the environment’s fundamentals. We study a framework in which agents face a choice between two actions, 0 and 1 (e.g., whether to pursue a certain level of education, switch to Linux OS, etc.). Agents are linked through a social network, and an agent’s payoffs from each action depend on the number of neighbors she has and her neighbors’ choices. The diffusion process is defined so that at each period, each agent best responds to the actions taken by her neighbors in the previous period, assuming that her neighbors follow the population distribution of actions (a mean-field approximation). Steady states correspond to equilibria of the static game. Under some simple conditions, equilibria take one of two forms. Some are stable, so that a slight perturbation to any such equilibrium would lead the diffusion process to converge back to that equilibrium point. Other equilibria are unstable, so that a slight change in the distribution of actions leads to a new distribution of actions and eventually to a stable steady state. We call such equilibria tipping points. We analyze how the environment’s fundamentals (cost distribution, payoffs, and network structure) affect the set of equilibria, and characterize the adoption patterns within the network. The paper relates to recent work on network games and network diffusion, including work by Stephen Morris (2000); Pastor-Satorras and Vespignani (2000); Mark E. J. Newman (2002); Dunia Lopez-Pintado (2004); Jackson and Brian W. Rogers (2007); Jackson and Yariv (2005); and Andrea Galeotti et al. (2005, henceforth GGJVY). Its contribution is in characterizing diffusion of strategic behavior and analyzing the stability properties of equilibria, and employing methods that allow us to make comparisons across general network structures and settings. Given that social networks differ substantially and systematically in structure across settings (e.g., ethnic groups, professions, etc.), understanding the implications of social structure on diffusion is an important undertaking for a diverse set of applications.
Fully QED/relativistic theory of light pressure on free electrons by isotropic radiation

A relativistic/QED theory of light pressure on electrons by an isotropic, in particular blackbody, radiation predicts thermalization rates of free electrons over the entire span of energies available in the lab and the nature. The calculations based on the QED Klein?Nishina theory of electron-photon scattering and relativistic Fokker?Planck equation, show that the transition from classical (Thompson) to QED (Compton) thermalization determined by the product of electron energy and radiation temperature, is reachable under conditions for controlled nuclear fusion, and predicts large acceleration of electron thermalization in the Compton domain and strong damping of plasma oscillations at the temperatures near plasma nuclear fusion.
Normalization of flow-mediated dilation to shear stress area under the curve eliminates the impact of variable hyperemic stimulus.

Normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress area under the curve (peak FMD:SSAUC ratio) has recently been proposed as an approach to control for the large inter-subject variability in reactive hyperemia-induced shear stress; however, the adoption of this approach among researchers has been slow. The present study was designed to further examine the efficacy of FMD normalization to shear stress in reducing measurement variability. Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 healthy, physically active young adults (25.3 ± 0. 6 yrs; 10 men, 10 women) by manipulating forearm cuff occlusion duration: 1, 2, 3, 4, and 5 min, in a randomized order. A venous blood draw was performed for determination of baseline whole blood viscosity and hematocrit. The magnitude of occlusion-induced forearm ischemia was quantified by dual-wavelength near-infrared spectrometry (NIRS). Brachial artery diameters and velocities were obtained via high-resolution ultrasound. The SSAUC was individually calculated for the duration of time-to-peak dilation. One-way repeated measures ANOVA demonstrated distinct magnitudes of occlusion-induced ischemia (volume and peak), hyperemic shear stress, and peak FMD responses (all p < 0.0001) across forearm occlusion durations. Differences in peak FMD were abolished when normalizing FMD to SSAUC (p = 0.785). Our data confirm that normalization of FMD to SSAUC eliminates the influences of variable shear stress and solidifies the utility of FMD:SSAUC ratio as an index of endothelial function.