cssi/SciSciGPT-SciSciNet huggingface dataset:
Accelerating Divergent Applications on SIMD Architectures Using Neural Networks

The purpose of this research is to find a neural-network-based solution to the well-known problem of branch divergence in Single Instruction Multiple Data (SIMD) architectures. Our approach differs from existing techniques that handle branch (or control-flow) divergence, which use costly hardware modifications, low-utilization masking techniques, or static prediction methods. As we examine divergent applications, we characterize the degree of data-dependent control flow seen in each and isolate the code regions (or “kernels”) that cause the most performance degradation due to branch divergence. We then train neural networks (NNs) offline to approximate these kernels and inject the NN computations directly into the applications as substitutes for the kernels they approximate. This essentially translates control flow into nondivergent computation, trading off precision for performance. As our methodology manipulates application source code directly, it is inherently platform agnostic and can be adopted as a general means for accelerating divergent applications on data-parallel architectures. In this article, we present the Neuralizer, an automated software flow for kernel identification, NN training, and NN integration, as well as supplementary user-controlled optimization techniques. Evaluating our approach on a variety of divergent applications run on a Graphics Processing Unit (GPU), we on average achieve performance gains of 13.6 × and energy savings of 14.8 × with 96p accuracy.
The performance of coal‐burning electric generating units in the United States: 1960–1980

This paper studies determinants of the thermal efficiency and reliability of coal-burning electric generating units using a new, comprehensive, unbalanced panel data set. For two major technological groups consistent and efficient estimates are obtained of the effects of unit age, vintage, scale, operating practices, and coal quality. Large utilities integrated into design and engineering appear to obtain superior unit performance. Implications of our results for life-cycle generation costs, regulators' performance norms, and the complex pattern of technological change in this industry are discussed.
MOLECULAR MACHINERY MEDIATING VESICLE BUDDING, DOCKING AND FUSION

A general machinery buds and fuses transport vesicles which connect intracellular compartments with each other and allow communication with the extracellular environment. Cytoplasmic coat proteins deform membranes to bud vesicles and interact directly or indirectly with cargo molecules. Compartment-specific SNAREs (SNAP receptors) on vesicles and target membranes dock vesicles and provide a scaffolding for the general fusion machinery to initiate lipid bilayer fusion.
Renal transplantation between identical twins: a review.

The experience of transplantation between identical twins, occurring primarily at the Peter Bent Brigham Hospital, is reviewed. The remarkable success of this human experiment beginning in 1954 and ending, at least for the present in our hospital, in 1976, has confirmed early hopes that clinical renal transplantation may be an extremely effective treatment for end-stage renal failure. Based largely on this seminal experience, investigations into experimental aspects of transplantation immunology, autoimmunity, and the general host responses, as well as developments in the field of nephrology and overall care of patients with endstage renal disease, have burgeoned. Indeed, during recent years, transplantation of several organs including heart, heart-lung, liver, and kidney have proven remarkably successful. As knowledge and application in this field continues to expand, increasing numbers of patients with organ failure can expect to return to relatively normal lives.
The Evolution of the Reference Interview

SUMMARY While the reference interview remains the vehicle whereby librarians are able to understand the information needs of users in order to assist them, the ways in which the reference interview is conducted have changed with time and technology. This chapter provides a brief history of the evolution of the reference interview, from the face-to-face transaction to the current trends of e-mail and chat software mediated reference interviews, and examines application of these current trends in virtual reference services. While the methods of conducting the reference interview have certainly changed, the ultimate goal of meeting the information needs of the user remains constant.
On the converse to a theorem of Atiyah and Bott

Let G be a complex reductive group and let C be a smooth curve of genus at least one. We prove a converse to a theorem of Atiyah-Bott concerning the stratification of the space of holomorphic G-bundles on C. In case the genus of C is one, we establish that one has a stratification in the strong sense. The paper concludes with a characterization of the minimally unstable strata in case G is simple.
Infrared detectors with plasmonic structures

Infrared detectors (3–20 µm) are important due to three main reasons. Firstly, the atmosphere is transparent in the two bands referred to as mid wave infrared (MWIR, 3–5 µm) and long wave infrared (8–12 µm) making it possible to see through fog and smoke under poor visibility conditions. Secondly, a lot of chemical species have characteristic absorption features in this wavelength range making these detectors vital for remote sensing and stand off detection. Finally, there is blackbody emission from living objects at these wavelengths making it possible to use them for “night vision” and thermography applications such as surveillance and medical diagnostics.
Macroeconomic Performance and Collective Bargaining: An International Perspective

This paper critically reviews the research on how collective bargaining systems influence macroeconomic performance in industrialized countries. The review considers effects of bargaining level, coordination, and corporatist institutional arrangements. Key empirical results turn out to be quite fragile, and much of the paper explores issues of measurement and specification that account for the fragility. The paper concludes that complementarities between key institutions and between institutions and the economic environment may be more important for macroeconomic performance than the effects of individual institutions, and it suggests research strategies.
Consequence for Wavefunction Collapse Model of the Sudbury Neutrino Observatory Experiment

It is shown that data on the dissociation rate of deuterium obtained in an experiment at the Sudbury Neutrino Observatory provides evidence that the Continuous Spontaneous Localization wavefunction collapse model should have mass–proportional coupling to be viable.
EXPANSION OF THE SUPERNOVA REMNANT RCW 103

A new CCD image of the supernova remnant RCW 103 was taken in 1995 to compare with a photographic plate taken in 1970. We calculated the proper-motion expansion of the outer edge and several filaments by comparing radial slices through each of the data sets. The mean expansion rate of the outer edge is 1\farcs 8~±~0\farcs 2 per 25 years, or about 1100 km sec-1. At this velocity the remnant is most likely around 2000 years old. In addition, it must have made the transition from the double-shock phase of evolution to the point-blast phase fairly recently for the initial energy of the supernova explosion to be within a reasonable rang.
Brain drain: why top management bolts after M&As

Purpose – This paper aims to analyzes merger, firm, and country characteristics that may explain the root causes of long‐term executive instability in target company top management teams.Design/methodology/approach – Mergers involve two different groups of executives – executives in place at the time of the acquisition (“incumbents”) and those brought into the target after the acquisition (“new‐hires”). In order to understand why many target companies experience long‐term instability in their top management teams, patterns of turnover in these two distinct groups were analyzed over a 17‐year period in 730 target companies.Findings – Analysis of the data revealed that a range of factors create conditions in target companies that lead to prolonged leadership instability. Different deal types such as tender offers, hostile takeovers, divestitures, and leveraged buyouts, the nature of merger negotiations, growth and profitability of the target company, headquarters location of the acquirer–whether foreign or ...
System sketching: the generation of rapid prototypes for transaction based systems

Rapid prototypes are important tools to aid users in formulating their software requirements. The system sketch is a rapid prototype which shows the user the functions of the system he has specified.In this paper we present a system sketch produced by a processor written in LISP which interprets software requirements stated in an expanded PSL-like requirements language. Discussions of the language and the processor are presented.
String theory dynamics in various dimensions

Abstract The strong coupling dynamics of string theories in dimension d ⩾ 4 are studied. It is argued, among other things, that eleven-dimensional supergravity arises as a low energy limit of the ten-dimensional Type IIA superstring, and that a recently conjectured duality between the heterotic string and Type IIA superstrings controls the strong coupling dynamics of the heterotic string in five, six, and seven dimensions and implies S -duality for both heterotic and Type II strings.
Demand system estimation with upward-sloping supply.

This paper motivates the use of three-stage least squares in demand systems estimation in which disaggregated data are used and supply adjustment costs exist. A system of Japanese meat expenditures is used as an example. It is shown that all but one of the meat prices are endogenous to the system. Correcting these prices for endogeneity has a significant effect on the calculated elasticities. Cet ouvrage utilise la technique de minimisation des moindres carres a trois etapes dans un systeme de demande utilisant des donnees desagregees et ou des couts d'ajustement de l'offre existent. Un systeme de depenses pour les viandes au Japon est utilise comme exemple. Il est demontre que tous les prix des viandes sont endogenes a l'exception d'un seul. Les elasticites qui sont derivees sont tres sensibles a l'endogenization des prix. SUMMARY There are three important implications of this work. First, demand systems estimates that overlook supply response are as subject to simultaneous equations bias as single ad hoc demand equations. Theil shows theoretically that assuming supply curves are perfectly elastic, when in fact they are not will underestimate price responsiveness in demand equations. An empirical example is presented that demonstrates that the price elasticities generally increase when upward-sloping supplies are assumed. Second, the iterative testing procedure presented may provide direction for model building when the true structure of the system is unknown. For example, the results of the Wu-Hausman test indicate that assuming chicken supply is perfectly elastic in a model of the Japanese livestock industry is justified. The results also indicate that the supplies of Wagyu beef, dairy beef, pork and fish are upward-sloping and therefore should be modeled as endogenous variables in the demand system. Third, the results emphasize the sensitivity of projections of Japanese beef imports to the assumptions underlying the demand system. If perfectly elastic meat supplies are assumed for an analysis of reducing Japanese beef import liberalization, the results will likely underestimate the impacts on beef imports. In summary, the supply curves for agricultural products tend to slope upward within the time periods used for traditional policy analysis and demand system estimation, which in turn implies that prices are determined endogenously within the system. Endogenous price determination is contrary to the assumptions that underlie the theoretical foundations and many empirical applications of demand systems. We present a methodology to test for and adjust demand systems for endogeneity. The importance of this adjustment is demonstrated by using an analysis of the liberalization of the Japanese beef market.
Computing the complexity of the relation of isometry between separable Banach spaces

We compute here the Borel complexity of the relation of isometry between separable Banach spaces, using results of Gao, Kechris [2], Mayer-Wolf [5], and Weaver [8]. We show that this relation is Borel bireducible to the universal relation for Borel actions of Polish groups. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Data management at the National Space Science Data Center

Data management functions of National Space Science Data Center /NSSDC/, discussing data processing and information system for secondary usage
Robots and humans in space flight: Technology, evolution, and interplanetary travel

Abstract This essay explores the history and possible future for human/robotic space flight. One area where all space flight visionaries failed to make meaningful predictions was in the rapidly advancing capabilities of robotics and electronics. For example, when Arthur C. Clarke envisioned geosynchronous telecommunications satellites in 1945 he believed that they would require humans working onboard. It is, therefore, easy to conceive of the motivation that led people like Clarke and Wernher von Braun to imagine the necessity to station large human crews in space. In this instance some of the most forward-thinking space flight advocates utterly failed to anticipate the electronics/digital revolution then just beginning. Humans, space flight visionaries always argued, were a critical element in the exploration of the solar system and ultimately beyond. Human destiny required our movement beyond this planet, ultimately to the colonization of the galaxy as a means of assuring the survival of the species. With the rapid advance of electronics in the 1960s, however, some began to question the role of humans in space exploration. It is much less expensive and risky to send robot explorers than to go ourselves. This debate reached saliency early on and became an important part of the space policy debate late in the twentieth century. The paper describes the history and an analysis of how we arrived at this point in human space flight, as well as the relative merits of human versus robotic space exploration. In essence, the old paradigm for human exploration—ultimately becoming an interstellar species—is outmoded and ready for replacement. This paper looks to the future of humans and robots in space, and suggests that it is conceivable that a post-human cyborg species may develop in a future extraterrestrial environment.
New directions in legal information processing

Present areas of application of computers to the law fall into three broad categories: (1) those involving applications of business accounting techniques such as in tax preparation and client billing, (2) those involving data management techniques such as law enforcement, criminal justice, and keyword legal source material information systems, and (3) those involving on-line file manipulation in such areas as text-editing and drafting. These systems demonstrate that computers can work very well with problems that can be expressed in terms of numbers or information that can be handled on the basis of its external form.
New Silhouette Disks with Reflection Nebulae and Outflows in the Orion Nebula and M43

We report the detection of several new circumstellar disks seen in silhouette against background nebular light in the outskirts of the Orion Nebula and the neighboring H II region M43. These were detected as part of our Hα survey of Orion with the Advanced Camera for Surveys on board the Hubble Space Telescope. Several of the disks show bipolar reflection nebulae, microjets, or pronounced temporal variability of their central stars. The relatively large fraction of bipolar reflection nebulae and microjets in our sample may be a selection effect caused by the faint nebular background far from the Trapezium. Two disks in our sample are large and particularly noteworthy: A nearly edge-on disk, d216-0939, is located several arcminutes northwest of M43 and resembles the famous HH 30 disk/jet system in Taurus. It drives the 0.15 pc long bipolar outflow HH 667 and exhibits a remarkable asymmetric reflection nebula caused by the tilt of the flared disk. With a diameter of ~26 (1200 AU), d216-0939 is as large as the giant edge-on silhouette disk d114-426 in the core of the Orion Nebula. The large disk d253-1536 is located in a binary system embedded within an externally ionized giant proplyd in M43. The disk exhibits distortions that we attribute to tidal interactions with the companion star. The bipolar jet HH 668 emerges from the proplyd ionization front in a direction orthogonal to the disk and can be traced to the young star embedded within it. A bow shock lies 54'' south of this binary system along the outflow axis. Proper motions over a 1.4 yr baseline confirm that these emission knots are indeed moving away from d253-1536 with speeds as high as ~330 km s-1 in the HH 668 microjet and slower motion farther from the star.
Computer-based Learning of Neuroanatomy: A Longitudinal Study of Learning, Transfer, and Retention

A longitudinal experiment was conducted to evaluate the effectiveness of new methods for learning neuroanatomy with computer-based instruction. Using a three-dimensional graphical model of the human brain and sections derived from the model, tools for exploring neuroanatomy were developed to encourage adaptive exploration. This is an instructional method that incorporates graphical exploration in the context of repeated testing and feedback. With this approach, 72 participants learned either sectional anatomy alone or whole anatomy followed by sectional anatomy. Sectional anatomy was explored either with perceptually continuous navigation through the sections or with discrete navigation (as in the use of an anatomical atlas). Learning was measured longitudinally to a high performance criterion. Subsequent tests examined transfer of learning to the interpretation of biomedical images and long-term retention. There were several clear results of this study. On initial exposure to neuroanatomy, whole anatomy was learned more efficiently than sectional anatomy. After whole anatomy was mastered, learners demonstrated high levels of transfer of learning to sectional anatomy and from sectional anatomy to the interpretation of complex biomedical images. Learning whole anatomy prior to learning sectional anatomy led to substantially fewer errors overall than learning sectional anatomy alone. Use of continuous or discrete navigation through sectional anatomy made little difference to measured outcomes. Efficient learning, good long-term retention, and successful transfer to the interpretation of biomedical images indicated that computer-based learning using adaptive exploration can be a valuable tool in instruction of neuroanatomy and similar disciplines.
Chiral N‐Acylhydrazones: Versatile Imino Acceptors for Asymmetric Amine Synthesis

Addition to C=N bonds with acyclic stereocontrol offers excellent potential for development of new carbon–carbon bond construction approaches to chiral amines. This review features the design and implementation of novel chiral N-acylhydrazones as versatile imino acceptors for addition of radicals and nucleophiles. The initial design was inspired by the goal of asymmetric radical addition to chiral C=N radical acceptors. The chiral N-acylhydrazones are prepared from commercially available materials by amination of 4-alkyl-2-oxazolidinones with NH2+ equivalents to afford N-(amino)oxazolidinones, followed by condensation with aldehydes or ketones. These chiral N-acylhydrazones undergo addition reactions with various partners, including radicals, allylsilanes, allylindiums, silyl enol ethers, and hydride donors. The adducts can be converted to chiral amines by N–N bond cleavage. Reliably high stereoselectivity was observed for addition reactions in the presence of Lewis acids. For the prototype case, N-acylhydrazones derived from (S)-4-benzyl-2-oxazolidinone, two alternative stereocontrol models are consistent with the results. Lewis acids capable of chelate formation activate through two-point binding of the imino nitrogen and the carbonyl oxygen, exposing the si-face for addition. On the other hand, boron trifluoride activates through a monodentate interaction, favoring a rotamer which exposes the re-face. Applications from the author’s research program are reviewed together with results from other groups. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Current Developments in HIV Chemotherapy

HIV infection is the leading cause of death worldwide and despite major advances in treatment, more new cases were diagnosed in 2004 than any previous year. Current treatment regimens are based on the use of two or more drugs from two or more classes of inhibitors termed highly active antiretroviral therapy (HAART). Although HAART is capable of suppressing viral loads to undetectable levels, problems of toxicity, patient adherence, and particularly the emergence of drug-resistant viruses continues to spur the development of new chemotherapeutics to combat HIV. Clinical candidates from the four existing classes of inhibitors are presented in this review along with lead compounds against new viral targets, with special emphasis on HIV integrase.
Evidence for the depletion of ammonia in the Uranus atmosphere

The theoretical disk brightness temperature spectra for Uranus are computed and compared with the observed microwave spectrum. It is shown that the emission observed at short centimeter wavelengths originates deep below the region where ammonia would ordinarily begin to condense. We demonstrate that this result is inconsistent with a wide range of atmospheric models in which the partial pressure of NH3 is given by the vapor-pressure equation in the upper atmosphere. It is estimated that the ammonia mixing ratio must be less than 10 to the minus 6 in the 150 to 200 K temperature range. This is two orders of magnitude less than the expected mixing ratio based on solar abundances. The evidence for this depletion and a possible explanation are discussed.
A New Timescale for Period Change in the Pulsating DA White Dwarf WD 0111+0018

We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10–12 s s–1, exceeds by more than two orders of magnitude the expected rate from cooling alone for this class of slow and simply evolving pulsating WDs. This result indicates the presence of an additional timescale for period evolution in these pulsating objects. We also measure the rates of period change of nonlinear combination frequencies and show that they share the evolutionary characteristics of their parent modes, confirming that these combination frequencies are not independent modes but rather artifacts of some nonlinear distortion in the outer layers of the star.
An approach to the pyrroloquinoline core of martinelline and martinellic acid

Abstract An expedient method for the assembly of the pyrroloquinoline skeleton found in the martinelline alkaloids using a [3+2] cycloaddition of an azomethine ylide and an alkene has been developed.
Continuous families of rational surface automorphisms with positive entropy

For any k we construct k-parameter families of rational surface automorphisms with positive entropy. These are automorphisms of surfaces \({\mathcal{X}}\), which are constructed from iterated blowups over the projective plane. In certain cases we are able to determine the exact automorphism group of \({\mathcal{X}}\), as well as when two of these surfaces are inequivalent.
Lifetimes of Carbon Stripping Foils

The lifetime of carbon foils used as strippers in terminals of tandem electrostatic accelerators or as strippers prior to injection into post accelerators increases with increasing ion velocity. The usefulness of such strippers is affected by foil thickening processes due to hydrocarbon cracking and radiation induced effects as well as by pronounced increases in energy straggling from non-uniformity. The lifetime of the foils is substantially increased if the foil is heated during exposure to temperatures of about 400$sup 0$C.
Ferromagnetic grain boundary signature in die-upset Re-Fe-B magnets

Previous nanostructural and nanocompositional studies performed on the boundaries of deformed grains in two die-upset rare earth magnets with bulk compositions Nd{sub 13.75}fe{sub 80.25}B{sub 6} and Pr{sub 13.75}Fe{sub 80.25}B{sub 6} indicate that the intergranular phase in many grain boundaries is enriched in iron relative to the bulk. The authors present here preliminary magnetic data that provide further evidence that this grain boundary phase is indeed iron-rich, and in fact appears to be ferromagnetic. Hysteresis loops were performed at 800 K on die-upset magnets with the above compositions. Each sample showed a clear hysteresis with coercivities between 34 and 40 Oe and an average remanence 4{pi}B{sub R} of 6.8 G for the Nd-based sample and 10.3 G for the Pr-based sample. The ferromagnetic signals measured at high temperature in these magnets are attributed to the iron-rich grain boundary phase. The implications of this conclusion with respect to coercivity are discussed.
The New X-Ray Transient SAX J1711.6-3808: Decoupling between Its 3-20 keV Luminosity and Its State Transitions

We present a study of the correlated spectral and timing behavior of the new X-ray transient SAX J1711.6-3808 during its 2001 outburst using data obtained with the Rossi X-Ray Timing Explorer (RXTE). We also investigate the correlations between those source properties and the 3-20 keV X-ray luminosity. The behavior of the source during the observations can be divided into two distinct state types. During the "hard" state, the energy spectra are relatively hard and can be described by only a power-law component, and the characteristic frequencies (i.e., the frequency of the 1-7 Hz quasi-periodic oscillations, observed for the first time in this source) in the power spectra are low. However, during the "soft" state, the spectra are considerably softer (in addition to the power-law component, a soft component below 8 keV is necessary to fit the spectra), and the frequencies are the highest observed. Remarkably, this distinction into two separate states cannot be extrapolated to also include the 3-20 keV X-ray luminosity. Except for one observation, this luminosity steadily decreased, but the hard state was observed both at the highest and lowest observed luminosities. In contrast, the soft state occurred only at intermediate luminosities. This clearly demonstrates that the state behavior of SAX J1711.6-3808 is decoupled from its X-ray luminosity and that if the X-ray luminosity traces the mass accretion rate in SAX J1711.6-3808, then the state transitions are not good accretion rate indicators, or vice versa. The RXTE data of SAX J1711.6-3808 do not allow us to conclusively determine the exact nature of the compact object in this system. The source resembles both neutron star and black hole systems when they have low luminosities. We discuss our results with respect to the correlated timing and spectral behavior observed in other low-mass X-ray binaries and the implications of our results for the modeling of the outburst light curves of X-ray transients.
GPU Acceleration of Newton's Method for Large Systems of Polynomial Equations in Double Double and Quad Double Arithmetic

In order to compensate for the higher cost of double double and quad double arithmetic when solving large polynomial systems, we investigate the application of the NVIDIA Tesla K20C graphics processing unit (GPU). The focus on this paper is on Newton's method, which requires the evaluation of the polynomials, their derivatives, and the solution of a linear system to compute the update to the current approximation for the solution. The reverse mode of algorithmic differentiation for a product of variables is rewritten in a binary tree fashion so all threads in a block can collaborate in the computation. For double arithmetic, the evaluation and differentiation problem is memory bound, whereas for complex quad double arithmetic the problem is compute bound. With acceleration we can double the dimension and get results that are twice as accurate in about the same time.
Results from atmospheric neutrinos

With the announcement of new evidence for muon neutrino disappearance observed by the super-Kamiokande experiment, the more than a decade old atmospheric neutrino anomaly moved from a possible indication for neutrino oscillations to an apparently inescapable fact. The evidence is reviewed, and new indications are presented that the oscillations are probably between muon and tau neutrinos. Implications and future directions are discussed.
PRELIMINARY ORBIT OF THE YOUNG BINARY HARO 1-14c

Using the Keck Interferometer, we spatially resolved the orbit of the pre-main-sequence (PMS) binary, Haro 1-14c, for the first time. We present these interferometric observations along with additional spectroscopic radial velocity measurements of the components. We performed a simultaneous orbit fit to the interferometric visibilities and the radial velocities of Haro 1-14c. Based on a statistical analysis of the possible orbital solutions that fit the data, we determined component masses of M 1 = 0.96+0.27 –0.08 M ☉ and M 2 = 0.33+0.09 –0.02 M ☉ for the primary and secondary, respectively, and a distance to the system of 111+19 –18 pc. The distance measurement is consistent with the close distance estimates of the Ophiuchus molecular cloud. Comparing our results with evolutionary tracks suggests an age of 3-4 Myr for Haro 1-14c. With additional interferometric measurements to improve the uncertainties in the masses and distance, we expect the low-mass secondary to provide important empirical data for calibrating the theoretical evolutionary tracks for PMS stars.
Curvature and uniformization

We approach the problem of uniformization of general Riemann surfaces through consideration of the curvature equation, and in particular the problem of constructing Poincare metrics (i.e., complete metrics of constant negative curvature) by solving the equation Δu-e2u=Ko(z) on general open surfaces. A few other topics are discussed, including boundary behavior of the conformal factore2u giving the Poincare metric when the Riemann surface has smoothly bounded compact closure, and also a curvature equation proof of Koebe's disk theorem.
Measuring the invisible Higgs width at the 7 and 8 TeV LHC

The LHC is well on track toward the discovery or exclusion of a light Standard Model (SM)-like Higgs boson. Such a Higgs has a very small SM width and can easily have large branching fractions to physics beyond the SM, making Higgs decays an excellent opportunity to observe new physics. Decays into collider-invisible particles are particularly interesting as they are theoretically well motivated and relatively clean experimentally. In this work we estimate the potential of the 7 and 8 TeV LHC to observe an invisible Higgs branching fraction. We analyze three channels that can be used to directly study the invisible Higgs branching ratio at the 7 TeV LHC: an invisible Higgs produced in association with (i) a hard jet; (ii) a leptonic Z; and (iii) forward tagging jets. We find that the last channel, where the Higgs is produced via weak boson fusion, is the most sensitive, allowing branching fractions as small as 40 % to be probed at 20 inverse fb for masses in the range between 120 and 170 GeV, including in particular the interesting region around 125 GeV. We provide an estimate of the 8 TeV LHC sensitivity to an invisibly-decaying Higgs produced via weak boson fusion and find that the reach is comparable to but not better than the reach at the 7 TeV LHC. We further estimate the discovery potential at the 8 TeV LHC for cases where the Higgs has substantial branching fractions to both visible and invisible final states.
Feedback through overhearing

In this paper we examine the value of feedback that comes from overhearing, without dedicated feedback resources. We focus on a simple model for this purpose: a deterministic two-hop interference channel, where feedback comes from overhearing the forward-links. A new aspect brought by this setup is the dual-role of the relay signal. While the relay signal needs to convey the source message to its corresponding destination, it can also provide a feedback signal which can potentially increase the capacity of the first hop. We derive inner and outer bounds on the sum capacity which match for a large range of the parameter values. Our results identify the parameter ranges where overhearing can provide non-negative capacity gain and can even achieve the performance with dedicated-feedback resources. The results also provide insights into which transmissions are most useful to overhear.
Estimating credibility in Colombia's exchange-rate target zone

Abstract This paper analyzes credibility in the Colombian exchange-rate target zone. A model of imperfect credibility, in the spirit of Bertola and Svensson [Bertola, G., Svensson, L., 1993.“Stochastic devaluation risk and the empirical fit of target zone models. Review of Economic Studies 60, 689–712] is derived, and estimated using Colombian data. The main feature of the model is that central-parity depreciation expectations are endogenous with respect to the position of the exchange rate inside the target zone. The Krugman [Krugman, P., 1991. Target zones and exchange rate dynamics. Quarterly Journal of Economics 56 (3), 669–682] perfectly credible setup is a particular case of this general model. A key implication of the model is that depreciation expectations rise rather than fall as the exchange rate approaches the upper band. Using the method of simulated moments (MSM) to estimate the structural parameters underlying the model, I find evidence suggesting that Colombia's exchange-rate target zone is properly described by a model of this nature.
Paying the doctor: evidence-based decisions at the point-of-care and the role of fee-for-service incentives

This article develops a framework for understanding how financial and nonfinancial incentives can complicate point-of-care decision-making by physicians, leading to the overuse or underuse of healthcare services. By examining the types of decisions that clinicians and patients make at the point-of-care, the framework clarifies how incentives can distort physicians' decisions about testing, diagnosis and treatment, as well as efforts to enhance patient adherence. The analysis highlights contributing factors that promote and impede evidence-based decision-making, using examples from the 'Choosing Wisely' program. It concludes with a summary of how the existing fee-for-service payment system in the USA may contribute to the problems of over- and under-testing, diagnosis and treatment, highlighted through the efforts of Choosing Wisely.
A direct detection of dust in the outer disks of nearby galaxies

We measure the extent of 100 μm galactic emission in two independent galaxy samples using the IRAS 100 μm Sky Survey images and constrain the distribution of dust at large (30 kpc) radii. The first sample consists of 90 nearby (v < 6000 km s-1) galaxies from the Third Reference Catalogue of Bright Galaxies with similar angular sizes and absolute luminosities (5' ≤ D25 ≤ 10' and -22.5 ≤ MB ≤ -18) that are isolated in the 100 μm images. The second sample consists of 24 local galaxies (v < 1500 km s-1, 10' ≤ D25 ≤ 30'). We rescale the 100 μm images of these galaxies using their optical diameters, D25, rotate the images using their optical major-axis position angle, construct the mean and median images, and rebin the final images into polar coordinates to study the 100 μm emission as a function of radius and azimuthal angle. We find that the 100 μm emission extends at least to radii of 33 kpc (2 σ detection) for the typical galaxy in the 5'–10' sample and to 21 kpc (2 σ detection) in the 10'–30' sample (H0 = 75 km s-1 Mpc-1). In both samples, the emission is preferentially elongated along the optical major axis. We fit an exponential to the 100 μm emission along the major axis and measure a scale length of 2.5 ± 0.8 kpc (90% confidence interval). Using a simple model that relates the far-IR emission to the stellar distribution, we examine the range of acceptable dust mass distributions allowed by our data and conclude that the dust is more extended than the starlight.
On the complexity of the uniform homeomorphism relation between separable Banach spaces

We investigate the uniform homeomorphism relation between separable Banach spaces and the related relation of local equivalence. We completely characterize the descriptive complexity of local equivalence in the Borel reducibility hierarchy. This also provides a lower bound for the complexity of the uniform homeomorphism.
Dynamical supersymmetric inflation

Abstract We propose a new class of inflationary models in which the scalar field potential governing inflation is generated by the same nonperturbative gauge dynamics that may lead to supersymmetry breaking. Such models satisfy constraints from cosmic microwave background measurements for natural values of the fundamental parameters in the theory. In addition, they have two particularly interesting characteristics: a “blue” spectrum of scalar perturbations, and an upper bound on the total amount of inflation possible.
Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets

Spitzer Space Telescope infrared observations indicate that several transiting extrasolar giant planets have thermal inversions in their upper atmospheres. Above a relative minimum, the temperature appears to increase with altitude. Such an inversion probably requires a species at high altitude that absorbs a significant amount of incident optical/UV radiation. Some authors have suggested that the strong optical absorbers titanium oxide (TiO) and vanadium oxide (VO) could provide the needed additional opacity, but if regions of the atmosphere are cold enough for Ti and V to be sequestered into solids they might rain out and be severely depleted. With a model of the vertical distribution of a refractory species in gaseous and condensed form, we address the question of whether enough TiO (or VO) could survive aloft in an irradiated planet's atmosphere to produce a thermal inversion. We find that it is unlikely that VO could play a critical role in producing thermal inversions. Furthermore, we find that macroscopic mixing is essential to the TiO hypothesis; without macroscopic mixing, such a heavy species cannot persist in a planet's upper atmosphere. The amount of macroscopic mixing that is required depends on the size of condensed titanium-bearing particles that form in regions of an atmosphere that are too cold for gaseous TiO to exist. We parameterize the macroscopic mixing with the eddy diffusion coefficient Kzz and find, as a function of particle size a, the values that Kzz must assume on the highly irradiated planets HD?209458b, HD?149026b, TrES-4, and OGLE-TR-56b to loft enough titanium to the upper atmosphere for the TiO hypothesis to be correct. On these planets, we find that for TiO to be responsible for thermal inversions Kzz must be at least a few times 107 cm2 s?1, even for a = 0.1 ?m, and increases to nearly 1011 cm2 s?1 for a = 10 ?m. Such large values may be problematic for the TiO hypothesis, but are not impossible.
THE Blast-Wave-Driven Instability as a Vehicle for Understanding Supernova Explosion Structure

Blast-wave-driven instabilities play a rich and varied role in supernovae (SNe) evolution from explosion to remnant, but interpreting their role is difficult due to the enormous complexity of stellar systems. We consider the simpler idealized problem of an interface between two constant-density fluids perturbed from spherical and driven by a central blast wave. Where valid, the existence of unified solutions suggests that general conclusions can be drawn about the likely asymptotic structure of the mixing zone. To this end, we apply buoyancy-drag and bubble merger models that include effects of divergence and compressibility. In general, these effects preclude the true self-similar evolution of classical Rayleigh-Taylor (RT), but can be incorporated into a quasi-self-similar growth model. Loss of memory of initial conditions (ICs) can occur in the model, but requires pre-explosion mode numbers higher than predicted for Type II SNe, suggesting that their late-time structure is influenced by details of the initial perturbations. Where low modes dominate, as in the Type Ia Tycho remnant, they result from initial perturbations rather than generation from smaller scales. Therefore, the structure observed now contains direct information about the explosion process. When large-amplitude modes exist in the ICs, the contribution from the Richtmyer-Meshkov (RM) instability is significant compared to RT. Such RM growth can yield proximity of the forward shock to the growing spikes and structure that strongly resembles that observed in Tycho. Laser-driven laboratory experiments offer a promising avenue for testing model and simulation descriptions of blast-wave-driven instabilities and making connections to their astrophysical counterparts.
Head and Neck Anatomy and Ultrasound Correlation

Thorough knowledge of the complex anatomy of the head and neck is essential to understanding the ultrasonographic appearance of this region. The intimate familiarity with anatomic structures obtained by performing surgical procedures makes active radiographic imaging modalities like ultrasound especially suited for use by surgeons. An understanding of the normal sonographic appearance of head and neck structures is critical to recognizing abnormal pathology.
Communication and Coordination in Social Networks

I model people in a coordination game who use a communication network to tell each other their willingness to participate. The minimal sufficient networks for coordination can be interpreted as placing people into a hierarchy of social roles or "stages": "initial adopters", then "followers", and so on down to "late adopters". A communication network helps coordination in exactly two ways: by informing each stage about earlier stages, and by creating common knowledge within each stage. We then consider two examples: first we show that "low dimensional" networks can be better for coordination even though they have far fewer links than "high dimensional" networks; second we show that wide dispersion of "insurgents", people predisposed toward participation, can be good for coordination but too much dispersion can be bad. Although collective action depends on both social structure and individual incentives, these integral aspects have been formalized separately, in the fields of social network theory and game theory. By considering them together, this paper engages the classic question of which structures are conducive to coordination and shows that structure and strategy are related in a mutually interesting way. Here we consider a coordination game in which each person wants to participate only if others participate. Social structure is thought of as a communication network by which people tell each other their willingness to participate. Each person knows whether her neighbours in the network are willing, but does not know about anyone else. Our model is thus a game of incomplete information in which each person, given his local knowledge, decides whether to participate. The main result is a characterization of the minimal sufficient networks for coordination in terms of a hierarchy of social roles or "stages": "initial adopters", then "followers", and so on down to "late adopters", for example. A communication network helps coordination in exactly two ways: by informing each stage about earlier stages, and by creating common knowledge within each stage. We also consider two simple examples: first, we show that low dimension or "strong link" networks can be better for coordination even though they have far fewer links than high dimension or "weak link" networks; second, we show that wide dispersion of "insurgents", people predisposed toward participation, can be good for coordination but too much dispersion can be bad. This paper is built on the assumption that the most basic and common mechanism for coordination is the "I'll go if you go" mechanism: individuals first communicate with each other about their preferences, and then each individual chooses whether to participate or not. Hence a person's participation depends on what he knows about his neighbours; it does not depend solely on their participation itself, either through learning, adaptation, or social influence. The physical analogies of contagion or diffusion are not
Polynomial algorithms for LP over a subring of the algebraic integers with applications to LP with circulant matrices

We show that a modified variant of the interior point method can solve linear programs (LPs) whose coefficients are real numbers from a subring of the algebraic integers. By defining the encoding size of such numbers to be the bit size of the integers that represent them in the subring, we prove the modified algorithm runs in time polynomial in the encoding size of the input coefficients, the dimension of the problem, and the order of the subring. We then extend the Tardos scheme to our case, obtaining a running time which is independent of the objective and right-hand side data. As a consequence of these results, we are able to show that LPs with real circulant coefficient matrices can be solved in strongly polynomial time. Finally, we show how the algorithm can be applied to LPs whose coefficients belong to the extension of the integers by a fixed set of square roots.
On the signature of short distance scale in the cosmic microwave background

Abstract We discuss the signature of the scale of short distance physics in the Cosmic Microwave Background. In addition to effects which depend on the ratio of Hubble scale H during inflation to the energy scale M of the short distance physics, there can be effects which depend on φ 2 /M 4 where φ is the classical background of the inflaton field. Therefore, the imprints of short distance physics on the spectrum of Cosmic Microwave Background anisotropies generically involve a double expansion . We present some examples of a single scalar field with higher order kinetic terms coupled to Einstein gravity, and illustrate that the effects of short distance physics on the Cosmic Microwave Background can be substantial even for H ⪡ M , and generically involve corrections that are not simply powers of H / M . The size of such effects can depend on the short distance scale non-analytically even though the action is local.
Historical Development of Rapid Methods and Automation in Microbiology

Rapid methods and automation in microbiology comprise a dynamic area of research and study. The field encompasses a wide variety of subjects in theoretical and applied microbiology. This article traces the major developments of this field since the late 1960s, detailed with dares and locations of major international meetings on the subject as well as listing of major books, proceedings, and articles concerning this topic. The article should be of interest to all scientists who want to know the key developments, current status, and possible future trends of the field.