cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Number of Rich Lines in High Dimensional Real Vector Spaces

In this short note we use the Polynomial Ham Sandwich Theorem to strengthen a recent result of Dvir and Gopi about the number of rich lines in high dimensional Euclidean spaces. Our result shows that if there are sufficiently many rich lines incident to a set of points then a large fraction of them must be contained in a hyperplane.
Price Dispersion on the Internet: Good Firms and Bad Firms

Internet firms charge a wide range of prices for homogeneous products, and high-priced firms remain high-priced and low-priced firms remain low-priced over long periods. One explanation is that high-price firms are charging a premium for superior service. An alternative, price-dispersion explanation is that firms vary the prices for informed and uniformed consumers (Salop and Stiglitz, 1977) or serious shoppers and others (Wilde and Schwartz, 1979). The pricing pattern for a digital camera and a flatbed scanner is consistent with the price-dispersion model and inconsistent with the service-premium hypothesis.
Superstrings: The view from below

We review the Standard Model in a form conducive to formulating its possible short distance extensions. This depends on the value of the Higgs mass, the only unknown parameter of the model. We suggest methods to reproduce many of the small numbers in the model in terms of scale ratios, applying see-saw like ideas to the breaking of chiral symetries. We then investigate how the N=1 Standard Model extrapolated to or near the Planck scale can fit superstring models, emphasizing the use of some non-renormalizable operators generic to superstrings.
Brane Gas Cosmology, M-Theory and Little String Theory

We generalize the Brane Gas Cosmological Scenario to M-theory degrees of freedom, namely M5 and M2 branes. Without brane intersections, the Brandenberger Vafa(BV) arguments applied to M-theory degrees of freedom generically predict a large 6 dimensional spacetime. We show that intersections of M5 and M2 branes can instead lead to a large 4 dimensional spacetime. One dimensional intersections in 11D is related to (2,0) little strings (LST) on NS5 branes in type IIA. The gas regime of membranes in M-theory corresponds to the thermodynamics of LST obtained from holography. We propose a mechanism whereby LST living on the worldvolume of NS5 (M5)-branes wrapping a five dimensional torus, annihilate most efficiently in 3+1 dimensions leading to a large 3+1 dimensional spacetime. We also show that this picture is consistent with the gas approximation in M-theory.
Simulation Approaches to General Probabilistic Inference on Belief Networks

A number of algorithms have been developed to solve probabilistic inference problems on belief networks. These algorithms can be divided into two main groups: exact techniques which exploit the conditional independence revealed when the graph structure is relatively sparse, and probabilistic sampling techniques which exploit the “conductance” of an embedded Markov chain when the conditional probabilities have non-extreme values. In this paper, we investigate a family of “forward” Monte Carlo sampling techniques similar to Logic Sampling [Henrion, 1988] which appear to perform well even in some multiplyconnected networks with extreme conditional probabilities, and thus would be generally applicable. We consider several enhancements which reduce the posterior variance using this approach and propose a framework and criteria for choosing when to use those enhancements.
Kinetics of Oxidation of Carbide and Silicide Dispersed Phases in Oxide Matrices

A variety of oxidizable but self-protective materials are potential candidates for reinforcing media in ceramic-ceramic composites for use as high-temperature structural components in oxidizing environments. The oxidation kinetics of 10% to 30% dispersions of particles of SiC and MoSi{sub 2} as well as SiC whiskers in fully dense matrices of alumina, mullite, and a silicate were determined from 1,200{degree} to 1,500{degree}C. SiC and MoSi{sub 2}, which form self-protective coatings of silica when heated as bulk pieces, exhibit an increase in their parabolic rate constants of 15-fold when incorporated in alumina or mullite matrices and almost 30-fold when incorporated in a strontium-aluminum-disilicate matrix. Reaction mechanisms are discussed.
A Scalable and Efficient Probabilistic Information Retrieval and Text Mining System

A system for probabilistic information retrieval and text mining that is both scalable and efficient is presented. Separate feature extraction or stop-word lists are not needed since the system can remove unneeded parameters dynamically based on a local mutual information measure. This is shown to be as effective as using a global measure. A novel way ofstoring system parameters eliminates the need for a ranking step during information retrieval from queries. Probability models over word contexts provide a method to suggest related words that can be added to a query. Test results are presented on a categorization task and screen shots from a live system are shown to demonstrate its capabilities.
$2$-adic Behavior of Numbers of Domino Tilings

We study the $2$-adic behavior of the number of domino tilings of a $2n \times 2n$ square as $n$ varies. It was previously known that this number was of the form $2^nf(n)^2$, where $f(n)$ is an odd, positive integer. We show that the function $f$ is uniformly continuous under the $2$-adic metric, and thus extends to a function on all of $Z$. The extension satisfies the functional equation $f(-1-n) = \pm f(n)$, where the sign is positive iff $n \equiv 0,3 \pmod{4}$.
Applications of helical-chiral pyridines as organocatalysts in asymmetric synthesis.

: A new family of chiral pyridines has been designed and synthesized for use in asymmetric organocatalysis. Thus, helical-chiral pyridines induce high enantioselectivity in a range of mechanistically unrelated, synthetically significant transformations, including Friedel-Crafts alkylation with nitroalkenes, periselective Diels-Alder reactions with nitroalkenes, the ring-opening of epoxides with a chloride nucleophile, and the propargylation of aldehydes.
Quantum suppression of superconductivity in ultrathin nanowires

It is of fundamental importance to establish whether there is a limit to how thin a superconducting wire can be, while retaining its superconducting character--and if there is a limit, to determine what sets it. This issue may also be of practical importance in defining the limit to miniaturization of superconducting electronic circuits. At high temperatures, the resistance of linear superconductors is caused by excitations called thermally activated phase slips. Quantum tunnelling of phase slips is another possible source of resistance that is still being debated. It has been theoretically predicted that such quantum phase slips can destroy superconductivity in very narrow wires. Here we report resistance measurements on ultrathin ( Rq, which we explain in terms of proliferation of quantum phase slips and a corresponding localization of Cooper pairs.
Appraising the Thailand village fund

The Thailand Village Fund is the second-largest microcredit scheme in the world. Nearly 80,000 elected local Village Fund committees administer loans that reach 30 percent of all households. The value of Village Fund loans has remained steady since 2006, even without new infusions of government funds, and loans go disproportionately to the poor. Based mainly on a custom-built survey of more than 3,000 Village Funds conducted in 2010, this paper evaluates the performance of Village Funds, which it argues are best modeled as altruistic, and do not appear to be subject to elite capture. As expected, profit rates are difficult to model, but the regression analysis shows that loan recovery rates, total lending, credit ratings, and the proportion of loans going to the poor are all higher when a Village Fund borrows additional funds from a formal bank and on-lends to households, as was done by one in five Village Funds. An economic analysis suggests that Village Fund benefits exceed the costs. Most Village Funds are social rather than financial intermediaries; they have little incentive to take risks or to innovate, which explains why Village Fund lending has not kept pace with the growth of the Thai economy.
Variance risk premiums and predictive power of alternative forward variances in the corn market

We propose a fear index for corn using the variance swap rate synthesized from out-of-the-money call and put options as a measure of implied variance. We find negative and time-varying variance risk premiums (realized variance minus implied variance) in the corn market from 1987 to 2009. Our results contrast with Egelkraut, Garcia, and Sherrick (2007), but are in line with the findings of Simon (2002). We conclude that our synthesized model-free implied variance estimation procedure contains superior information about future realized variance relative to traditional model-dependent estimating procedures: the implied variance model by Black (1976) and the seasonal GARCH(1, 1) forecasted variance model. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark 32:587–608, 2012
Intellectual Property Law and Indigenous Peoples: Adapting Copyright Law to the Needs of a Global Community

The definition and scope of intellectual property and associated laws are under intense debate in the emerging discourse surrounding intellectual property and human rights. These debates primarily arise within the context of indigenous peoples' rights to protection and ownership of culturally specific properties. It is true that intellectual property laws are based on Western, developed markets, Western concepts of creation and invention, and Western concepts of ownership. But whatever their origins, those laws have been, and currently are, the primary vehicle for the protection of artistic, literary, and scientific works worldwide. To segregate indigenous interests from this international legal regime, particularly in light of the increasing globalization of markets, is to deny indigenous peoples both a powerful legal shield and a powerful legal sword. This Article argues that copyright laws can, and must, be expanded so as to maintain the vitality of, and protect, the creative artistic and literary works of indigenous cultures. The article proposes three major changes to international copyright law: the incorporation of collective and communal notions of authorship, the expansion of the originality requirement to reflect these forms of authorship, and the application of limits on the duration of copyright protection in a broader community context. The article further proposes that a variety of intellectual property mechanisms be drawn upon to provide special protection for “sacred” cultural works.
Exploration of RNA editing and design of robust genetic algorithms

This paper presents our computational methodology using genetic algorithms (GA) for exploring the nature of RNA editing. These models are constructed using several genetic editing characteristics that are gleaned from the RNA editing system as observed in several organisms. We have expanded the traditional genetic algorithm with artificial editing mechanisms as proposed by (Rocha, 1997). The incorporation of editing mechanisms provides a means for artificial agents with genetic descriptions to gain greater phenotypic plasticity, which is environmentally regulated. Our first implementations of these ideas have shed some light into the evolutionary implications of RNA editing. Based on these understandings, we demonstrate how to select proper RNA editors for designing more robust GAs, and the results show promising applications to real-world problems. We expect that the framework proposed both facilitate determining the evolutionary role of RNA editing in biology, and advance the current state of research in genetic algorithms.
Growth of solutions for QG and 2D Euler equations

The work of Constantin-Majda-Tabak [1] developed an analogy between the Quasi-geostrophic and 3D Euler equations. Constantin, Majda and Tabak proposed a candidate for a singularity for the Quasi-geostrophic equation. Their numerics showed evidence of a blow-up for a particular initial data, where the level sets of the temperature contain a hyperbolic saddle. The arms of the saddle tend to close in finite time, producing a sharp front. Numerics studies done later by Ohkitani-Yamada [8] and Constantin-Nie-Schorghofer [2], with the same initial data, suggested that instead of a singularity the derivatives of the temperature were increasing as double exponential in time. The study of collapse on a curve was first studied in [1] for the Quasi-geostrophic equation where they considered a simplified ansatz for classical frontogenesis with trivial topology. At the time of collapse, the scalar θ is discontinuous across the curve x2 = f(x1) with different limiting values for the temperature on each side of the front. They show that under this topology the directional field remains smooth up to the collapse, which contradicts the following theorem proven in [1]:
Optimization of Radiation Therapy Fractionation Schedules in the Presence of Tumor Repopulation

We analyze the effect of tumor repopulation on optimal dose delivery in radiation therapy. We are primarily motivated by accelerated tumor repopulation toward the end of radiation treatment, which is believed to play a role in treatment failure for some tumor sites. A dynamic programming framework is developed to determine an optimal fractionation scheme based on a model of cell kill from radiation and tumor growth in between treatment days. We find that faster tumor growth suggests shorter overall treatment duration. In addition, the presence of accelerated repopulation suggests larger dose fractions later in the treatment to compensate for the increased tumor proliferation. We prove that the optimal dose fractions are increasing over time. Numerical simulations indicate a potential for improvement in treatment effectiveness.
North American west coast summer low cloudiness: Broadscale variability associated with sea surface temperature

Six decades of observations at 20 coastal airports, from Alaska to southern California, reveal coherent interannual to interdecadal variation of coastal low cloudiness (CLC) from summer to summer over this broad region. The leading mode of CLC variability represents coherent variation, accounting for nearly 40% of the total CLC variance spanning 1950–2012. This leading mode and the majority of individual airports exhibit decreased low cloudiness from the earlier to the later part of the record. Exploring climatic controls on CLC, we identify North Pacific Sea Surface Temperature anomalies, largely in the form of the Pacific Decadal Oscillation (PDO) as well correlated with, and evidently helping to organize, the coherent patterns of summer coastal cloud variability. Links from the PDO to summer CLC appear a few months in advance of the summer. These associations hold up consistently in interannual and interdecadal frequencies.
Electron-Ion Collisions

This discussion will concentrate on basic physics aspects of inelastic processes of excitation, ionization, and recombination that occur during electron-ion collisions. Except for cases of illustration along isoelectronic sequences, only multicharged (at least +2) ions will be specifically discussed with some emphasis of unique physics aspects associated with ionic charge. The material presented will be discussed from a primarily experimental viewpoint with most attention to electron-ion interacting beams experiments.
Compositions, Partitions, and Fibonacci Numbers

A bijective proof is given for the following theorem: the number of compositions of n into odd parts equals the number of compositions of n + 1 into parts greater than one. Some commentary about the history of partitions and compositions is provided.
A one-dimensional $N$ fermion problem with factorized $S$ matrix

A one dimensionalN Fermion problem with attractive or repulsiveδ function interaction is solved by Bethe's hypothesis. TheS matrix factorizes and is explicitly given.
Deep convolutional inverse graphics network

This paper presents the Deep Convolution Inverse Graphics Network (DC-IGN), a model that aims to learn an interpretable representation of images, disentangled with respect to three-dimensional scene structure and viewing transformations such as depth rotations and lighting variations. The DC-IGN model is composed of multiple layers of convolution and de-convolution operators and is trained using the Stochastic Gradient Variational Bayes (SGVB) algorithm [10]. We propose a training procedure to encourage neurons in the graphics code layer to represent a specific transformation (e.g. pose or light). Given a single input image, our model can generate new images of the same object with variations in pose and lighting. We present qualitative and quantitative tests of the model's efficacy at learning a 3D rendering engine for varied object classes including faces and chairs.
Detecting discrepancies in numeric estimates using multidocument hypertext summaries

To aid analysts in detecting discrepancies in numeric estimates in news articles from multiple sources, we propose the automatic generation of hypertext summaries that include a high-level textual overview; tables of all comparable numeric estimates, organized to highlight discrepancies; and targeted access to supporting information from the original articles. The RIPTIDES system, which exemplifies the more flexible human-computer interface we propose, combines information extraction and multidocument summarization techniques to produce such hypertext summaries. In evaluating the system's ability to facilitate discrepancy detection, we find that, on average, the hypertext summaries provide a significantly more complete picture of the available information than the latest article.
Rainbow Connection of Random Regular Graphs

An edge colored graph $G$ is rainbow edge connected if any two vertices are connected by a path whose edges have distinct colors. The rainbow connection of a connected graph $G$, denoted by $rc(G)$, is the smallest number of colors that are needed in order to make $G$ rainbow connected. In this work we study the rainbow connection of the random $r$-regular graph $G=G(n,r)$ of order $n$, where $r\ge 4$ is a constant. We prove that with probability tending to one as $n$ goes to infinity the rainbow connection of $G$ satisfies $rc(G)=O(\log n)$, which is best possible up to a hidden constant.
Recovering spikes from noisy neuronal calcium signals via structured sparse approximation

Two-photon calcium imaging is an emerging experimental technique that enables the study of information processing within neural circuits in vivo. While the spatial resolution of this technique permits the calcium activity of individual cells within the field of view to be monitored, inferring the precise times at which a neuron emits a spike is challenging because spikes are hidden within noisy observations of the neuron's calcium activity. To tackle this problem, we introduce the use of sparse approximation methods for recovering spikes from the time-varying calcium activity of neurons. We derive sufficient conditions for exact recovery of spikes with respect to (i) the decay rate of the spike-evoked calcium event and (ii) the maximum firing rate of the cell under test. We find--both in theory and in practice--that standard sparse recovery methods are not sufficient to recover spikes from noisy calcium signals when the firing rate of the cell is high, suggesting that in order to guarantee exact recovery of spike times, additional constraints must be incorporated into the recovery procedure. Hence, we introduce an iterative framework for structured sparse approximation that is capable of achieving superior performance over standard sparse recovery methods by taking into account knowledge that spikes are non-negative and also separated in time. We demonstrate the utility of our approach on simulated calcium signals in various amounts of additive Gaussian noise and under different degrees of model mismatch.
On the Optimality of Treating Interference as Noise for $K$ -User Parallel Gaussian Interference Networks

It has been recently shown by Geng et al. that in a $K$ -user Gaussian interference network, if for each user, the desired signal strength is no less than the sum of the strengths of the strongest interference from this user and the strongest interference to this user (all signal strengths measured in dB scale), then power control and treating interference as noise (TIN) is sufficient to achieve the entire generalized degrees of freedom (GDoF) region. Motivated by the intuition that the deterministic model of Avestimehr et al. (Avestimehr-Diggavi-Tse deterministic model) is particularly suited for exploring the optimality of TIN, the results of Geng et al. are first re-visited under the ADT deterministic model, and are shown to directly translate between the Gaussian and deterministic settings. Next, we focus on the extension of these results to parallel interference networks, from a sum-capacity/sum-GDoF perspective. To this end, we interpret the explicit characterization of the sum capacity/sum GDoF of a TIN optimal network (without parallel channels) as a minimum weighted matching problem in combinatorial optimization, and obtain a simple characterization in terms of a partition of the interference network into vertex-disjoint cycles. Aided by insights from the cyclic partition, the sum-capacity optimality of TIN for $K$ -user parallel interference networks is characterized for the ADT deterministic model, leading ultimately to the corresponding GDoF results for the Gaussian setting. In both the cases, subject to a mild invertibility condition, the optimality of TIN is shown to extend to parallel networks in a separable fashion.
IL-17A–Mediated Protection against Acanthamoeba Keratitis

Acanthamoeba keratitis (AK) is a very painful and vision-impairing infection of the cornea that is difficult to treat. Although past studies have indicated a critical role of neutrophils and macrophages in AK, the relative contribution of the proinflammatory cytokine, IL-17A, that is essential for migration, activation, and function of these cells into the cornea is poorly defined. Moreover, the role of the adaptive immune response, particularly the contribution of CD4(+) T cell subsets, Th17 and regulatory T cells , in AK is yet to be understood. In this report, using a mouse corneal intrastromal injection-induced AK model, we show that Acanthamoeba infection induces a strong CD4(+) T effector and regulatory T cell response in the cornea and local draining lymph nodes. We also demonstrate that corneal Acanthamoeba infection induces IL-17A expression and that IL-17A is critical for host protection against severe AK pathology. Accordingly, IL-17A neutralization in Acanthamoeba-infected wild-type mice or Acanthamoeba infection of mice lacking IL-17A resulted in a significantly increased corneal AK pathology, increased migration of inflammatory cells at the site of inflammation, and a significant increase in the effector CD4(+) T cell response in draining lymph nodes. Thus, in sharp contrast with other corneal infections such as herpes and Pseudomonas aeruginosa keratitis where IL-17A exacerbates corneal pathology and inflammation, the findings presented in this article suggest that IL-17A production after Acanthamoeba infection plays an important role in host protection against invading parasites.
Global Optimization For Molecular Clusters Using A New Smoothing Approach

Strategies involving smoothing of the objective function have been used to help solve difficult global optimization problems arising in molecular chemistry. This paper proposes a new smoothing approach and examines some basic issues in smoothing for molecular configuration problems. We first propose a new, simple algebraic way of smoothing the Lennard-Jones energy function, which is an important component of the energy in many molecular models. This simple smoothing technique is shown to have close similarities to previously-proposed, spatial averaging smoothing techniques. We also present some experimental studies of the behavior of local and global minimizers under smoothing of the potential energy in Lennard-Jones problems. An examination of minimizer trajectories from these smoothed problems shows significant limitations in the use of smoothing to directly solve global optimization problems.
Magnesium Aluminum Spinel (MgAl2O4)

Publisher Summary Magnesium aluminum spinel (MgAl2O4) is a face-centered cubic material, the prototype for the spinel structural family, which includes binary oxides, sulfides, and selenides. The space group is Fd3m, unit cell length is 0.8084 nm, and the unit cell has eight formula units. The positions of the ions in the unit cell have been determined by both X-ray and neutron diffraction techniques. There is an inverse spinel structure, wherein the aluminum ions occupy both Td and D3d sites, and the magnesium ions occupy some of the D3d sites. The occurrence of the normal, inverse, or in-between structure depends on the ionic size, method of preparation, and composition. Natural magnesium aluminum spinel has the normal spinel structure; however synthetic forms of spinel prepared at high temperature have the inverse structure. The composition of magnesium aluminum spinel varies from near stoichiometric to highly alumina-rich. Optical-quality spinel can be synthetically made with a variety of techniques including: growth using the Czochralski method, the gradient furnace technique, hot pressing of powder, press forging, flame fusion, and fusion casting.
Cubical Convex Ear Decompositions

We consider the problem of constructing a convex ear decomposition for a poset. The usual technique, introduced by Nyman and Swartz, starts with a $CL$-labeling and uses this to shell the 'ears' of the decomposition. We axiomatize the necessary conditions for this technique as a "$CL$-ced" or "$EL$-ced". We find an $EL$-ced of the $d$-divisible partition lattice, and a closely related convex ear decomposition of the coset lattice of a relatively complemented finite group. Along the way, we construct new $EL$-labelings of both lattices. The convex ear decompositions so constructed are formed by face lattices of hypercubes. We then proceed to show that if two posets $P_{1}$ and $P_{2}$ have convex ear decompositions ($CL$-ceds), then their products $P_{1}\times P_{2}$, $P_{1}\check{\times} P_{2}$, and $P_{1}\hat{\times} P_{2}$ also have convex ear decompositions ($CL$-ceds). An interesting special case is: if $P_{1}$ and $P_{2}$ have polytopal order complexes, then so do their products.
Climate stability during the Pliocene warm period

[1] We present a high-resolution climate record from a sediment core spanning an 80-kyr interval of time during the mid-Pliocene epoch, when warmer conditions and lower global ice volume prevailed worldwide. Oxygen and carbon isotope analyses were made on benthic and planktonic foraminifera from ODP Site 981 in the North Atlantic. The amplitude and approximate recurrence interval of suborbital variations in these records are comparable to those of Holocene and marine isotope stage 11 (MIS 11) records from the North Atlantic. We conclude that the mid-Pliocene warm interval was a time of relative climatic stability. These results suggest that warmer climatic conditions alone may not necessarily enhance variability in the climate system, a finding that may facilitate predictions of 21st century climatic response to anthropogenic warming.
Online Updating of Statistical Inference in the Big Data Setting

We present statistical methods for big data arising from online analytical processing, where large amounts of data arrive in streams and require fast analysis without storage/access to the historical data. In particular, we develop iterative estimating algorithms and statistical inferences for linear models and estimating equations that update as new data arrive. These algorithms are computationally efficient, minimally storage-intensive, and allow for possible rank deficiencies in the subset design matrices due to rare-event covariates. Within the linear model setting, the proposed online-updating framework leads to predictive residual tests that can be used to assess the goodness of fit of the hypothesized model. We also propose a new online-updating estimator under the estimating equation setting. Theoretical properties of the goodness-of-fit tests and proposed estimators are examined in detail. In simulation studies and real data applications, our estimator compares favorably with competing approaches...
INFORMAL CONTROL AND ILLICIT DRUG TRADE

Antidrug legislation and enforcement are meant to reduce the trade in illegal drugs by increasing their price. Yet the unintended consequence is an increase in informal control—including retaliation, negotiation, avoidance, and toleration—among drug users and dealers. Little existing theory or research has explored the connections between informal control and drug trading. This article uses the rational choice and opportunity perspectives to explore the question: How and why does the frequency and seriousness of popular justice—as a whole or for each form—affect the price and rate of drug sales? The proposed theory is grounded on and illustrated with qualitative data obtained from drug dealers. This article concludes by discussing the scholarly and policy implications.
Migraine Headache and Labor Market Outcomes

While migraine headache can be physically debilitating, no study has attempted to estimate its effects on labor market outcomes. Using data drawn from the National Longitudinal Study of Adolescent Health, we estimate the effect of being diagnosed with migraine headache on labor force participation, hours worked, and wages. Ordinary least squares (OLS) estimates suggest that migraines are associated with reduced labor force participation and lower wages among females. A negative association between migraine headache and the wages of female respondents is also obtained using an instrumental variables (IV) approach, although the IV estimates are imprecise relative to the OLS estimates.
Superconducting Microwave Technology

Superconductivity is a remarkable state of matter in which electric current can flow inside materials without any detectable resistance. In a superconductor, perfect electric conductivity or zero resistivity occurs only below a “critical temperature” TC. A direct current induced in a superconducting ring has been shown to persist for over 2 years without any measurable decay. Another important characteristic of superconductors was the discovery by W. Meissner and R. Ochsenfeld in 1933 that a superconductor expels all magnetic flux from its interior; that is, a superconductor is also a perfect diamagnet. A key area of technological applications of superconductors is in high-frequency devices, particularly at frequencies in the radiowave, microwave, and millimeterwave spectral ranges. Keywords: superconductivity; critical temperature; zero resistivity; passive devices; active elements
Production of hypertension in the rat by substituting hypertonic sodium chloride solutions for drinking water.

Summary and Conclusions(1) In 3 experiments, systolic blood pressure measurements were made on 27 control rats and on 31 animals watered with hypertonic sodium chloride solutions for a period of 6 weeks.(2)The animals watered with hypertonic saline solutions developed an arterial hypertension after a latent period of one to 4 weeks. At autopsy this was found! to be associated with an hypertrophy of the heart and kidneys relative to body weight.(3)Some possible mechanisms for the development of this hypertension are discussed.(4)The substitution of hypertonic sodium chloride solutions for the drinking water affords a simple, inexpensive, and dependable method for the production of arterial hypertension in the rat.
The type and stable type of the boundary of a Gromov hyperbolic group

Consider an ergodic non-singular action \(\Gamma \curvearrowright B\) of a countable group on a probability space. The type of this action codes the asymptotic range of the Radon–Nikodym derivative, also called the ratio set. If \(\Gamma \curvearrowright X\) is a pmp (probability-measure-preserving) action, then the ratio set of the product action \(\Gamma \curvearrowright B\times X\) is contained in the ratio set of \(\Gamma \curvearrowright B\). So we define the stable ratio set of \(\Gamma \curvearrowright B\) to be the intersection over all pmp actions \(\Gamma \curvearrowright X\) of the ratio sets of \(\Gamma \curvearrowright B\times X\). By analogy, there is a notion of stable type which codes the stable ratio set of \(\Gamma \curvearrowright B\). This concept is crucially important for the identification of the limit in pointwise ergodic theorems established by the author and Amos Nevo. Here, we establish a general criteria for a nonsingular action of a countable group on a probability space to have stable type \(III_\lambda \) for some \(\lambda >0\). This is applied to show that the action of a non-elementary Gromov hyperbolic group on its boundary with respect to a quasi-conformal measure is not type \(III_0\) and, if it is weakly mixing, then it is not stable type \(III_0\).
On the thermodynamic stability of odd-frequency superconductors

The thermodynamic stability of odd-frequency pairing states is investigated within an Eliashberg-type framework. We find the rigorous result that in the weak coupling limit a continuous transition from the normal state to a spatially homogeneous odd-in-ω superconducting state is forbidden, irrespective of details of the pairing interaction and of the spin symmetry of the gap function. For isotropic systems, it is shown that the inclusion of strong coupling corrections does not invalidate this result. We discuss a few scenarios that might escape these thermodynamic constraints and permit stable odd-frequency pairing states.
Heterotic string models in curved spacetime

Abstract We explore the possibility of string theories in only four spacetime dimensions without any additional compactified dimensions. We show that, provided the theory is defined in curved spacetime that has a cosmological interpretation, it is possible to construct consistent heterotic string theories based on a few non-compact current algebra cosets. We classify these models. The gauge groups that emerge fall within a remarkably narrow range and include the desirable low energy flavor symmetry of SU(3)×SU(2)×U(1). The quark and lepton states, which come in color triplets and SU(2) doublets, are expected to emerge in several families.
DENSITY FUNCTIONAL STUDIES OF IRIDIUM CATALYZED ALKANE DEHYDROGENATION

Publisher Summary There are three mechanisms proposed for the acceptorless reaction: the dissociative pathway (D), associative pathway (A) and interchange pathway (I), whose importance may depend on the temperature, concentration of reactive species (alkane, alkene, and dihydrogen), and phosphine substituents. This chapter discusses the elementary reaction steps of these mechanisms focusing primarily on the anthraphos systems. The chapter describes the impact of different methods (coupled cluster, configuration–interaction and various DFT functionals), different basis sets, and phosphine substituents on the oxidative addition of methane to related Iridium (Ir) systems. The chapter compares the elementary reaction steps, including the effect of reaction conditions such as temperature, hydrogen pressure, alkane and alkene concentration, phosphine substituents and alternative metals (Rh). The chapter describes how these elementary steps constitute the reaction mechanisms.
Spin Hall Effect

It is proposed that when a charge current circulates in a paramagnetic metal a transverse spin imbalance will be generated, giving rise to a ``spin Hall voltage.'' Similarly, it is proposed that when a spin current circulates a transverse charge imbalance will be generated, giving rise to a Hall voltage, in the absence of charge current and magnetic field. Based on these principles we propose an experiment to generate and detect a spin current in a paramagnetic metal.
Aiming for the Ideal Synthesis

The field of total synthesis has a rich history and a vibrant future. Landmark advances and revolutionary strides in the logic of synthesis have put the practicing chemist in the enviable position of being able to create nearly any molecule with enough time and effort. The stage is now set for organic chemists to aim for "ideality" in the way molecules are synthesized. This perspective presents a simple and informative definition of "ideality" and demonstrates its use during the self-evaluation of several syntheses from our laboratory.
AUTOREGRESSIVE TRANSFORMATIONS IN COINTEGRATED REGRESSIONS

Standard autocorrelation corrections applied to cointegrating regressions can lead to erroneous first-differencing. Such outcomes are shown to be possible under a range of environments, including cases with autocorrelation coefficients substantially less than 1. First-differencing of a cointegrating regression results in estimates that may bear little relation to the parameters in the original untransformed relation, resulting in misinterpretation of the parameter estimates. These results are proved analytically and demonstrated with simulations and empirical examples.
The Cope rearrangement in theoretical retrospect

Abstract This critical review highlights intricacies of the computational study of the Cope rearrangement of 1,5-hexadiene and its derivatives. It is demonstrated that a realistic potential energy surface in the transition region can be obtained only at very high levels of approximation. The emphasis is on the reasons why some generally reliable methods fail to make even qualitatively correct predictions about this reaction.
Exchange rate pass-through and credit constraints

Abstract The macroeconomic evidence of the short-term impact of exchange rates on exports and prices is notoriously weak. This paper examines the microfoundations of this disconnect. I study the response of firms' export and price setting decisions to fluctuations in exchange rates and credit conditions using firm-level survey data. Financially constrained firms pass through exchange rate changes to prices at almost twice the rate of unconstrained firms. Similarly, their export volumes are about twice as sensitive to exchange rate fluctuations. The effect of borrowing constraints is particularly strong during the recent financial crisis.
hPepT1 mediates bacterial tripeptide fMLP uptake in human monocytes

Here, we examined hPepT1 expression in the monocytic cell line, KG-1. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that hPepT1 is expressed in KG-1 cells, while cDNA cloning and direct sequencing confirmed the sequence of KG-1 hPepT1 (accession number, AY634368). Immunoblotting of cell lysates from KG-1 cells or macrophages isolated from human peripheral blood revealed a approximately 100 kDa immunoreactive band mainly present in the membrane fraction. Uptake experiments showed that the transport of 20 microM radiolabeled Gly-Sarcosine ([14C]Gly-Sar) in KG-1 cells was Na+, Cl- dependent and disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS)-sensitive. In addition, hPepT1 activity was likely to be coupled to a Na+/H+ exchanger, as evidenced by the fact that [14C]Gly-Sar uptake was not affected by the absence of Na+ when cells were incubated at low pH (5.2). Interestingly, hPepT1-mediated transport was reduced in KG-1 cells incubated at low pH as it was also observed in nonpolarized Caco2-BBE cells. This pattern of pH-dependence is due to a disruption of the driving force of hPepT1-mediated transport events. This was supported by our finding that nonpolarized cells, Caco2-BBE cells and KG-1 cells, have an increased permeability to H+ when compared to polarized Caco2-BBE cells. Finally, we showed that hPepT1 is responsible for transporting fMLP into undifferentiated and differentiated (macrophage-like) KG-1 cells. Together, these results show that hPepT1 is expressed in nonpolarized immune cells, such as macrophages, where the transporter functions best at the physiological pH 7.2. Furthermore, we provide evidence for hPepT1-mediated fMLP transport, which might constitute a novel immune cell activation pathway during intestinal inflammation.
Knowledge flows and insider trading

Much insider trading literature focuses on the redistribution of monetary rents. This focus has led to ambiguous and conflicting results, unable to identify who the clear winners and losers of insider trading legislation are. Lacking any clearly defined beneficiary, an analysis of the origins and continued support of such legislation is lacking. This paper rectifies this omission by reassessing the involved agents not in light of their relationship to a company, but from all roles of the knowledge transmission process: creator, distributor and user. Information distributors—large news companies and investment houses—are argued to be sufficiently well organized to lobby for maintained and strengthened legislation to protect rents that would otherwise be greatly diminished.
N=2 supersymmetric RG flows and the IIB dilaton

We show that there is a non-trivial relationship between the dilaton of IIB supergravity, and the coset of scalar fields in five-dimensional, gauged N=8 supergravity. This has important consequences for the running of the gauge coupling in massive perturbations of the AdS/CFT correspondence. We conjecture an exact analytic expression for the ten-dimensional dilaton in terms of five-dimensional quantities, and we test this conjecture. Specifically, we construct a family of solutions to IIB supergravity that preserve half of the supersymmetries, and are lifts of supersymmetric flows in five-dimensional, gauged N=8 supergravity. Via the AdS/CFT correspondence these flows correspond to softly broken N=4, large N Yang–Mills theory on part of the Coulomb branch of N=2 supersymmetric Yang–Mills. Our solutions involve non-trivial backgrounds for all the tensor gauge fields as well as for the dilaton and axion.
The national ignition facility: path to ignition in the laboratory

The National Ignition Facility (NIF) is a 192-beam laser facility presently under construction at LLNL. When completed, NIF will be a 1.8-MJ, 500-TW ultraviolet laser system. Its missions are to obtain fusion ignition and to perform high energy density experiments in support of the US nuclear weapons stockpile. Four of the NIF beams have been commissioned to demonstrate laser performance and to commission the target area including target and beam alignment and laser timing. During this time, NIF demonstrated on a single-beam basis that it will meet its performance goals and demonstrated its precision and flexibility for pulse shaping, pointing, timing and beam conditioning. It also performed four important experiments for Inertial Confinement Fusion and High Energy Density Science. Presently, the project is installing production hardware to complete the project in 2009 with the goal to begin ignition experiments in 2010. An integrated plan has been developed including the NIF operations, user equipment such as diagnostics and cryogenic target capability, and experiments and calculations to meet this goal. This talk will provide NIF status, the plan to complete NIF, and the path to ignition.
Motion Planning for Variable Inertia Mechanical Systems

In this paper, we generate gaits for mixed systems, that is, dynamic systems that are subject to a set of non-holonomic constraints. What is unique about mixed systems is that when we express their dynamics in body coordinates, the motion of these system can be attributed to two decoupled terms: the geometric and dynamic phase shifts. In our prior work, we analyzed systems whose dynamic phase shift was null by definition. Purely mechanical and principally kinematic systems are two classes of mechanical systems that have this property. We generated gaits for these two classes of systems by intuitively evaluating their geometric phase shift and relating it to a volume integral under well-defined height functions.
Heat Kernels, Smoothness Estimates, and Exponential Decay

In this article, we characterize functions whose Fourier transforms have exponential decay. We characterize such functions by showing that they satisfy a family of estimates that we call quantitative smoothness estimates (QSE). Using the QSE, we establish Gaussian decay in the “bad direction” for the □b-heat kernel on polynomial models in ℂn+1. On the transform side, the problem becomes establishing QSE on a heat kernel associated to the weighted \(\bar{\partial}\)-operator on L2(ℂ). The bounds are established with Duhamel’s formula and careful estimation. In ℂ2, we can prove both on and off-diagonal decay for the □b-heat kernel on polynomial models.
Novel entry to the Ergot alkaloids via ring closing metathesis

Abstract A novel entry the Ergot alkaloids has been developed. It features a Heck reaction followed by hydride capture to generate the key tricyclic intermediate 12 and a ring closing metathesis reaction to give the tetracyclic ergoline ring system 3 .
ShaneAO: wide science spectrum adaptive optics system for the Lick Observatory

A new high-order adaptive optics system is now being commissioned at the Lick Observatory Shane 3-meter telescope in California. This system uses a high return efficiency sodium beacon and a combination of low and high-order deformable mirrors to achieve diffraction-limited imaging over a wide spectrum of infrared science wavelengths covering 0.8 to 2.2 microns. We present the design performance goals and the first on-sky test results. We discuss several innovations that make this system a pathfinder for next generation AO systems. These include a unique woofer-tweeter control that provides full dynamic range correction from tip/tilt to 16 cycles, variable pupil sampling wavefront sensor, new enhanced silver coatings developed at UC Observatories that improve science and LGS throughput, and tight mechanical rigidity that enables a multi-hour diffraction-limited exposure in LGS mode for faint object spectroscopy science.
Gamma-ray flares and VLBI outbursts of blazars

A model is developed for the time dependent electromagnetic—radio to gamma-ray—emission of active galactic nuclei, specifically, the blazars, based on the acceleration and creation of leptons at a propagating discontinuity or front of a self-collimated Poynting flux jet. The front corresponds to a discrete relativistic jet component as observed with very long baseline interferometry (VLBI). Equations are derived for the number, momentum, and energy of particles in the front taking into account synchrotron, synchrotron-self-Compton (SSC), and inverse-Compton processes as well as photon-photon pair production. The apparent synchrotron, SSC, and inverse Compton luminosities as functions of time are determined. Predictions of the model are compared with observations in the gamma, optical, and radio bands. The delay between the high-energy gamma-ray flare and the onset of the radio is explained by self-absorption and/or free-free absorption by external plasma. Two types of gamma-ray flares are predicted: Compton dominated or SSC dominated, depending on the initial parameters in the front. The theory is applied to the recently observed gamma-ray flare of the blazar PKS 1622-297 (Mattox et al. 1997). Approximate agreement of theoretical and observed light curves is obtained for a viewing angle θobs ~ 0.1 rad, a black hole mass M ~ 3 × 109 M☉, and a magnetic field at the base of the jet B0 ~ 103 G.
Hadronic penguin B decays in the standard and the two-Higgs-doublet models

Abstract We study in next-to-leading order QCD hadronic penguin B decays in the Standard and two-Higgs-doublet models. Although the gluonic penguin dominates, we find the electroweak contribution non-negligible. In the Standard Model, the branching ratio for B → Xsφ is predicted to be in the range (0.6–2) × 10−4. The ranges of branching ratios for B → Kφ B → K ∗ φ , and Bs → φφ are (0.4−2) × 10−5, (0.2−1) × 10−5, and (0.15−0.5) × 10−5, respectively. The contribution from the charged Higgs boson in two Higgs doublet models depend on cot β, and can be as large as 40%.