cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of Selenium Status on Bovine Mononuclear Cell Function

The effects of selenium (Se) status on the distribution and functional capabilities of bovine peripheral blood mononuclear cells (PBMC) were examined. No differences in proliferative responses to mitogens, interleukin (IL)-2 production, IL-2 receptor expression, or lymphocyte trafficking patterns were observed between PBMC from dairy cows maintained on Se adequate or Se deficient diets. In contrast, Se deficiency significantly reduced the numbers of circulating monocytes when compared to cows fed a Se adequate diet. Differences in the number of circulating monocytes had no apparent effect on the accessary functions of these cells with respect to antigen presentation and IL-2 production. These results suggest that the effect of Se-modified diets on bovine defense mechanisms is not mediated by the ability of peripheral blood lymphocytes to respond to antigen and mature into immunocompetent cells.
The Formation and Dynamics of Super-Earth Planets

Super-Earths, objects slightly larger than Earth and slightly smaller than Uranus, have found a special place in exoplanetary science. As a new class of planetary bodies, these objects have challenged models of planet formation at both ends of the spectrum and have triggered a great deal of research on the composition and interior dynamics of rocky planets in connection to their masses and radii. Being relatively easier to detect than an Earth-sized planet at 1 AU around a G star, super-Earths have become the focus of worldwide observational campaigns to search for habitable planets. With a range of masses that allows these objects to retain moderate atmospheres and perhaps even plate tectonics, super-Earths may be habitable if they maintain long-term orbits in the habitable zones of their host stars. Given that in the past two years a few such potentially habitable super-Earths have in fact been discovered, it is necessary to develop a deep understanding of the formation and dynamical evolution of these ...
Picking Planar Edges; or, Drawing a Graph with a Planar Subgraph

Given a graph G and a subset F⊆EG of its edges, is there a drawing of G in which all edges of F are free of crossings? We show that this question can be solved in polynomial time using a Hanani-Tutte style approach. If we require the drawing of G to be straight-line, but allow up to one crossing along each edge in F, the problem turns out to be as hard as the existential theory of the real numbers.
Interpolation with Fourier-radial adaptive thresholding

Many interpolation methods are effective with regularly sampled or randomly sampled data, whereas the spatial sampling of seismic reflectivity data is typically neither regular nor random. Fourier-radial adaptive thresholding (FRAT) is a sparsity-promoting method in which the interpolated result is sparse in the frequency-wavenumber domain and is coherent in a manner consistent with that of a collection of unaliased plane waves. The sparsity and the desired pattern in the f-k domain are promoted by iterative soft thresholding and adaptive weighting; data in the f-k domain are transformed to polar coordinates and then low-pass filtered along the radial axis to generate the nonlinear weight. FRAT interpolates data that are randomly sampled and aliased; i.e., where the minimum distance between adjacent traces is greater than the Nyquist sampling interval. A conventional approach to solving this problem is to apply a cascade of two procedures: first a sparsity-based method, such as projection onto convex sets...
THE TRIGONOMETRIC PARALLAX OF CYGNUS X-1

We report a direct and accurate measurement of the distance to the X-ray binary Cygnus X-1, which contains the first black hole to be discovered. The distance of 1.86{sup +0.12}{sub -0.11} kpc was obtained from a trigonometric parallax measurement using the Very Long Baseline Array. The position measurements are also sensitive to the 5.6 day binary orbit and we determine the orbit to be clockwise on the sky. We also measured the proper motion of Cygnus X-1 which, when coupled to the distance and Doppler shift, gives the three-dimensional space motion of the system. When corrected for differential Galactic rotation, the non-circular (peculiar) motion of the binary is only about 21 km s{sup -1}, indicating that the binary did not experience a large 'kick' at formation.
Supramolecular assembly of a quaterthiophene surfactant

A newly synthesized oligothiophene surfactant self-assembles into unilamellar vesicles in aqueous solution and exhibits semiconductive behavior as a cast film.
Monopsony in the Low-Wage Labor Market? Evidence from Minimum Nurse Staffing Regulations

This paper provides direct evidence on the extent of monopsony power in the low-wage labor market by estimating the firm-level elasticity of labor supply for nurse aides in the long-term care (nursing home) industry. Using exogenous variation in hiring induced by the passage of a state minimum nurse staffing law, I find that facilities initially out of compliance with the new law did not have to raise their wage offers relative to their competitors in order to hire more nurses. While this is consistent with perfect competition in simple monopsony models of the labor market, I discuss how the results may be more ambiguous in more complicated models.
Optimal use of correlated information in mechanism design when full surplus extraction may be impossible

We study the mechanism design problem when the principal can condition the agent’s transfers on the realization of ex post signals that are correlated with the agent’s types. Cremer and McLean [Econometrica 53(1985) 345–361; 56(1988) 1247–1257], McAfee and Reny [Econometrica 60(2)(1992) 395–421], and Riordan and Sappington [J. Econ. Theory, 45(1988) 189–199] studied situations where the signals are such that full surplus can be extracted from every agent type. We study optimal utilization of the signals when there are fewer signals than types and the Riordan and Sappington conditions do not always hold. For some special cases, we show the level of surplus that can be extracted, and identify the agent types who obtain rent.
Cognitive Impairment in Older Patients With Breast Cancer Before Systemic Therapy: Is There an Interaction Between Cancer and Comorbidity?

Purpose To determine if older patients with breast cancer have cognitive impairment before systemic therapy. Patients and Methods Participants were patients with newly diagnosed nonmetastatic breast cancer and matched friend or community controls age > 60 years without prior systemic treatment, dementia, or neurologic disease. Participants completed surveys and a 55-minute battery of 17 neuropsychological tests. Biospecimens were obtained for APOE genotyping, and clinical data were abstracted. Neuropsychological test scores were standardized using control means and standard deviations (SDs) and grouped into five domain z scores. Cognitive impairment was defined as any domain z score two SDs below or ≥ two z scores 1.5 SDs below the control mean. Multivariable analyses evaluated pretreatment differences considering age, race, education, and site; comparisons between patient cases also controlled for surgery. Results The 164 patient cases and 182 controls had similar neuropsychological domain scores. Howeve...
Parton Saturation: An Overview

The idea of partons and the utility of using light-cone gauge in QCD are introduced. Saturation of quark and gluon distributions are discussed using simple models and in a more general context. The Golec-Biernat Wusthoff model and some simple phenomenology are described. A simple, but realistic, equation for unitarity, the Kovchegov equation, is discussed, and an elementary derivation of the JIMWLK equation is given.
Conflicts of Interest, Institutional Corruption, and Pharma: An Agenda for Reform:

When physicians' conflicts of interest arise from ties with drug firms, we should shift our focus to the pharmaceutical industry and improper dependencies that cause institutional corruption. This article analyzes eight forms of improper dependencies on pharma and proposes reforms.
Supporting reconfigurable object distribution for customizable web applications

Web applications are tightly coupled with the platforms that a particular service provider intends to support and the execution scenario envisioned at the design time Consequently, the resulting applications do not adapt well to all clients and runtime execution contexts The goal of our research is to develop methods and software to support reconfigurable distributed applications which can be customized to specific requirements Thinking in terms ofsoftware product line engineering [2], we need a product line for a given Web application, each instance of which is for a specific execution platform and context To achieve such a product line, we have to satisfy two requirements: universal accessibility and context-dependent component distribution.
Some aspects of the political philosophy of Frantz Fanon

Political philosophy is concerned with the ends and purposes of government. It involves a conception of “the good life” and is primarily, though perhaps not exclusively, concerned with human beings. A conception of the good life presumably implies a view of how to attain that end. In this view, then, political philosophy is also concerned with the question of means, or how is the good life to he won and secured for the members of a particular community or society or state? Of those people of African ancestry who have done systematic thinking about the ends and purposes of government in Africa in the period since the end of World War II, there are few who measure up to the stature and originality of Frantz Fanon. (For biographical sketches on Fanon, see Caute 1970; Geismar 1969, 1970; Cesaire et al. 1962; de Beauvoir 1965, Ch. 5, especially pp. 583, 591-597, 606-607.) A rejected evolue in both Martinique and France, Fanon came to realize the extent of his own depersonalization and that of other blacks. It was this awareness which, in Geismar's words (1969, p. 24), led him first to make “a revolutionary carthartic break with the past,” and then to “a more definite African revolutionary ending.” His life, as Aime Cesaire (1962, p. 119) pointed out, was short, active and full of personal tragedy.
O-SILYLATION OF SOME UNSATURATED CYCLIC PHOSPHINE OXIDES

Abstract The phosphoryl oxygen of 1.6-dihydrophosphinine oxides is silylated rapidly at room temperature by bis(trimethylsilyl)trifluoroacetamide; the product loses a ring proton to establish the resonance stabilized γ5-phosphinine ring system. Similar events take place with a 3-keto derivative of a tetrahydrophosphinine oxide, which also undergoes silylation of the keto oxygen. 1,4-Dihydro-lazaphosphinine are silylated to give 1,4-aza-γ5-phosphinines; their dibenzo derivatives (5,10-dihydrophenophosphazine oxides) require more forcing conditions (triethylsilyl bromide at 100°C) for phosphoryl silylation. These conditions are also effective for silylation of a 3-phospholene oxide.
On some integrals arising in mathematical physics

Abstract This paper presents in the first section the exact evaluation of three single integrals relating to the dielectric behavior of two-dimensional electron plasmas. In the second section we present a procedure for reducing 3d-dimensional integrals of the form: ∫∫∫ d q d p d k D(q)α( p + k + q )ƒ( p )[1−ƒ( p + q )]ƒ(k)[1−ƒ( k + q )] , where the vectors lie in d-dimensional space and ƒ denotes the Fermi function, to tractable form. The second-order exchange integral for a d-dimensional electron gas is taken as an example and is evaluated in closed form as a function of d.
Nuclear physics with a medium-energy Electron-Ion Collider

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy √s ∼ 20–70 GeV and luminosity ∼1034 cm−2 s−1 would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.
Capacity and Performance of Adaptive MIMO System Based on Beam-Nulling

In this paper, we propose a scheme called "beam-nulling". In the beam-nulling scheme, the eigenvector of the weakest subchannel is fed back and then signals are sent over a generated subspace orthogonal to the weakest subchannel. Theoretical analysis and numerical results show that the capacity of beam-nulling is closed to the optimal water-filling at medium SNR. Additionally, signal-to-interference-plus-noise ratio (SINR) of MMSE receiver is derived for beam-nulling. Then the associated average bit-error rate (BER) of beam-nulling is given numerically and verified by simulation. Simulation results are provided to compare beam-nulling with beamforming. To improve performance further, beam-nulling is concatenated with linear dispersion code. Simulation results are also provided to evaluate the concatenated scheme beamforming at the same data rate.
Entrepreneurship in Developing Countries

Between 1945 and 1980 nearly 100 colonies in Africa, Asia, and the Caribbean gained their independence and began the process of initiating a development strategy for their citizens. Sadly, many of those countries experienced neither significant per capita growth nor economic development (Easterly, 2001, 141–43). Indeed, moderate and extreme poverty remains a significant concern for many developing countries (Sachs, 2005, 22–23)
Intramolecular and Intermolecular Schmidt Reactions of Alkyl Azides with Aldehydes.

Abstract Despite recent advances in the use of alkyl azides in ring expansion reactions of ketones, there has been little work done on the corresponding chemistry of aldehydes. In the present study, the Lewis acid-promoted reactions of alkyl azides with aldehydes were studied in both intermolecular and intramolecular contexts. The intramolecular reactions of azidoalkyl aldehydes in which the azide and carbonyl groups were separated by 2–5 carbons were examined. Although the examples having the shortest tether failed (3-azidopropanals), each of the other systems gave good yields of either NH-substituted lactams (resulting from hydride migration in the initially formed azidohydrin adduct) or formamides (alkyl migration). The product formed was dependent on the chain length of the starting azido aldehyde. The intermolecular reactions were less efficient, requiring TiCl4 promotion for even moderate yields, and in each case gave mixtures of products resulting from hydride and alkyl migration.
3-Nitropropionic Acid Is a Suicide Inhibitor of Mitochondrial Respiration That, upon Oxidation by Complex II, Forms a Covalent Adduct with a Catalytic Base Arginine in the Active Site of the Enzyme

We report three new structures of mitochondrial respiratory Complex II (succinate ubiquinone oxidoreductase, E.C. 1.3.5.1) at up to 2.1 A resolution, with various inhibitors. The structures define the conformation of the bound inhibitors and suggest the residues involved in substrate binding and catalysis at the dicarboxylate site. In particular they support the role of Arg(297) as a general base catalyst accepting a proton in the dehydrogenation of succinate. The dicarboxylate ligand in oxaloacetate-containing crystals appears to be the same as that reported for Shewanella flavocytochrome c treated with fumarate. The plant and fungal toxin 3-nitropropionic acid, an irreversible inactivator of succinate dehydrogenase, forms a covalent adduct with the side chain of Arg(297). The modification eliminates a trypsin cleavage site in the flavoprotein, and tandem mass spectroscopic analysis of the new fragment shows the mass of Arg(297) to be increased by 83 Da and to have the potential of losing 44 Da, consistent with decarboxylation, during fragmentation.
Ex Post Regret and the Decentralized Sharing of Information

Abstract Firms reveal private information about the value of investment through their investment decisions. As a consequence they may have ex post regret once they see other firms' investments. We define a notion of rational expectations equilibrium for games which imposes a “no-regret” property. In this equilibrium, all firms make the same investment decision, but despite the absence of ex post regret, the investment herd can be inefficient. In addition equilibrium might not exist. We introduce a notion of probabilistic existence, and identify conditions under which, if the number of firms is large, enough information comes out so that investment herds are first-best efficient with high probability, and equilibrium exists with high probability.Journal of Economic LiteratureClassification Numbers: C7, D8.
Cooperative Robot Control and Concurrent Synchronization of Lagrangian Systems

Concurrent synchronization is a regime where diverse groups of fully synchronized dynamic systems stably coexist. We study global exponential synchronization and concurrent synchronization in the context of Lagrangian systems control. In a network constructed by adding diffusive couplings to robot manipulators or mobile robots, a decentralized tracking control law globally exponentially synchronizes an arbitrary number of robots, and represents a generalization of the average consensus problem. Exact nonlinear stability guarantees and synchronization conditions are derived by contraction analysis. The proposed decentralized strategy is further extended to adaptive synchronization and partial-state coupling.
Necessity as the mother of invention: Innovative responses to natural disasters

Abstract How do innovators respond to the shock of a natural disaster? Do natural disasters spur technical innovations that can reduce the risk of future hazards? This paper examines the impact of three types of natural disasters—floods, droughts and earthquakes—on the innovation of their respective mitigation technologies. Using patent and disaster data, our study is the first to empirically examine adaptation responses across multiple sectors at the country level. Considering the potential endogeneity of disaster damages, we use meteorological and geophysical data to create hazard intensity measures as instrumental variables. Overall, we show that natural disasters lead to more risk-mitigating innovations, while the degree of influence varies across different types of disasters and technologies.
What is a Blue Chip Recruit Worth? Estimating the Marginal Revenue Product of College Football Quarterbacks

The National Collegiate Athletic Association has faced growing scrutiny due to the perceived disparity between the compensation athletes receive and their contribution to athletic revenue. Our novel use of college football game–level statistics shows a gap of millions of dollars between compensation and marginal revenue product (MRP) for elite quarterbacks, consistent with previous studies. Professional sports typically weight pay toward ex ante expected value of performance rather than incentives that pay ex post of performance. Using high school prospect rankings, we show ex ante estimates of elite quarterback expected MRP are substantially lower, roughly US$400,000, and have limited statistical significance with respect to winning or revenue. Our ex ante measurements suggest that expected player value may be closer to the value of scholarships than previous research suggests due to the difficulty in predicting which high school quarterbacks will excel in college.
Game Theoretic Formation of a Centrality Based Network

We model the formation of networks as a game where players aspire to maximize their own centrality by increasing the number of other players to which they are path-wise connected, while simultaneously incurring a cost for each added adjacent edge. We simulate the interactions between players using an algorithm that factors in rational strategic behavior based on a common objective function. The resulting networks exhibit pair wise stability, from which we derive necessary stable conditions for specific graph topologies. We then expand the model to simulate non-trivial games with large numbers of players. We show that using conditions necessary for the stability of star topologies we can induce the formation of hub players that positively impact the total welfare of the network.
Evidence for Mass-dependent Circumstellar Disk Evolution in the 5 Myr Old Upper Scorpius OB Association

We present 4.5, 8, and 16 µm photometry from the Spitzer Space Telescope for 204 stars in the Upper Scorpius OB association. The data are used to investigate the frequency and properties of circumstellar disks around stars with masses between ~0.1 and 20 M_☉ at an age of ~5 Myr. We identify 35 stars that have emission at 8 or 16 µm in excess of the, stellar photosphere. The lower mass stars (~0.1–1.2M_☉) appear surrounded by primordial optically thick disks based on, the excess emission characteristics. Starsmoremassive than ~1.8M_☉ have lower fractional excess luminosities suggesting, that the inner ~10 AU of the disk has been largely depleted of primordial material. None of the G and F stars (~1.2–1.8 M_☉) in our sample have an infrared excess at wavelengths ≤16 µm. These results indicate that the mechanisms for, dispersing primordial optically thick disks operate less efficiently, on average, for low-mass stars, and that longer timescales are available for the buildup of planetary systems in the terrestrial zone for stars with masses ≾1 M_☉.
An inverse signal approach to computing the envelope of a real valued signal

We address the problem of estimating the envelope of a real valued signal, s(t), that is observed for a duration of T seconds. We model s(t) using a Fourier series, by considering periodic extensions of the signal. By using an analog of the autocorrelation method of linear prediction on the Fourier coefficients of s(t), the envelope of the signal is estimated without explicitly computing the analytic signal through Hilbert transformation. Using this method the envelope of a non-stationary signal can be computed by processing the signal through a sliding T-second window.
Coding for two-head recording systems

A reduction in the track width in disc-recording systems results in a desirable increase in areal density, but also in the undesirable appearance of inter-track interference (ITI) and loss of signal-to-noise ratio (SNR). One way the effects of ITI may be alleviated is through the use of multiple-head systems simultaneously writing and reading a number of adjacent tracks. In this paper we investigate the performance of two-track detectors, and design codes that combat two-dimensional interference patterns, ISI in the axial dimension, and ITI in the radial dimension, and recover the loss in SNR due to track-narrowing. Sliding-block decoders and reduced-complexity Viterbi detectors are also designed for these codes, which are seen to more than compensate for the performance loss for a large range of ITI levels. >
Stability of a strongly anisotropic thin epitaxial film in a wetting interaction with elastic substrate

The linear dispersion relation for surface perturbations, as derived by Levine et al., Phys. Rev. B, 75 (2007) 205312, is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained solid films.
Return Chasing in Bond Funds

We use a unique dataset of SEC Form N-SAR filings to examine the gross flows of U.S. bond funds. We find that gross inflows and outflows average around 4% of total net assets per month, but net flows average only 0.26%. When modeling these flows, we see that, as with equity funds, bond fund investors chase returns. Most of the return chasing is done by inflows. Funds with the highest decile of returns average 1% higher net flow and inflow per month, and the lowest-decile funds lose nearly 0.6% in assets per month. Next, we find that positive net flows cause bond funds to diversify their holdings regardless of fund size. Finally, we test whether flows predict returns and find that an inflow-weighted portfolio generates alphas of 0.8% per year. Bond inflows appear to be “smart money.”
PI(4,5)P2 regulates myoblast fusion through Arp2/3 regulator localization at the fusion site

Cell-cell fusion is a regulated process that requires merging of the opposing membranes and underlying cytoskeletons. However, the integration between membrane and cytoskeleton signaling during fusion is not known. Using Drosophila, we demonstrate that the membrane phosphoinositide PI(4,5)P2 is a crucial regulator of F-actin dynamics during myoblast fusion. PI(4,5)P2 is locally enriched and colocalizes spatially and temporally with the F-actin focus that defines the fusion site. PI(4,5)P2 enrichment depends on receptor engagement but is upstream or parallel to actin remodeling. Regulators of actin branching via Arp2/3 colocalize with PI(4,5)P2 in vivo and bind PI(4,5)P2 in vitro. Manipulation of PI(4,5)P2 availability leads to impaired fusion, with a reduction in the F-actin focus size and altered focus morphology. Mechanistically, the changes in the actin focus are due to a failure in the enrichment of actin regulators at the fusion site. Moreover, improper localization of these regulators hinders expansion of the fusion interface. Thus, PI(4,5)P2 enrichment at the fusion site encodes spatial and temporal information that regulates fusion progression through the localization of activators of actin polymerization.
Optimal PMU Placement for Power System Dynamic State Estimation by Using Empirical Observability Gramian

In this paper, the empirical observability Gramian calculated around the operating region of a power system is used to quantify the degree of observability of the system states under specific phasor measurement unit (PMU) placement. An optimal PMU placement method for power system dynamic state estimation is further formulated as an optimization problem which maximizes the determinant of the empirical observability Gramian and is efficiently solved by the NOMAD solver, which implements the Mesh Adaptive Direct Search algorithm. The implementation, validation, and the robustness to load fluctuations and contingencies of the proposed method are carefully discussed. The proposed method is tested on WSCC 3-machine 9-bus system and NPCC 48-machine 140-bus system by performing dynamic state estimation with square-root unscented Kalman filter. The simulation results show that the determined optimal PMU placements by the proposed method can guarantee good observability of the system states, which further leads to smaller estimation errors and larger number of convergent states for dynamic state estimation compared with random PMU placements. Under optimal PMU placements an obvious observability transition can be observed. The proposed method is also validated to be very robust to both load fluctuations and contingencies.
From Submit to Submitted via Submission: On Lexical Rules in Large-Scale Lexicon Acquisition

This paper deals with the discovery, representation, and use of lexical rules (LRs) during large-scale semi-automatic computational lexicon acquisition. The analysis is based on a set of LRs implemented and tested on the basis of Spanish and English business- and finance-related corpora. We show that, though the use of LRs is justified, they do not come cost-free. Semi-automatic output checking is required, even with blocking and preemtion procedures built in. Nevertheless, large-scope LRs are justified because they facilitate the unavoidable process of large-scale semi-automatic lexical acquisition. We also argue that the place of LRs in the computational process is a complex issue.
The N2K Consortium. VI. Doppler Shifts without Templates and Three New Short-Period Planets*

We present a modification to the iodine cell Doppler technique that eliminates the need for an observed stellar template spectrum. For a given target star, we iterate toward a synthetic template spectrum beginning with an existing template of a similar star. We then perturb the shape of this first-guess template to match the program observation of the target star taken through an iodine cell. The elimination of a separate template observation saves valuable telescope time, a feature that is ideally suited for the quick-look strategy employed by the "Next 2000 Stars" (N2K) planet search program. Tests using Keck HIRES (High Resolution Echelle Spectrometer) spectra indicate that synthetic templates yield a short-term precision of 3 m s^(-1) and a long-term, run-to-run precision of 5 m s^(-1). We used this new Doppler technique to discover three new planets: a 1.50M_J planet in a 2.1375 day orbit around HD 86081; a 0.71M_J planet in circular, 26.73 day orbit around HD 224693; and a Saturn-mass planet in an 18.179 day orbit around HD 33283. The remarkably short period of HD 86081b bridges the gap between the extremely short period planets detected in the Optical Gravitational Lensing Experiment (OGLE) survey and the 16 Doppler-detected hot Jupiters (P < 15 days), which have an orbital period distribution that piles up at about 3 days. We have acquired photometric observations of two of the planetary host stars with the automated photometric telescopes at Fairborn Observatory. HD 86081 and HD 224693 both lack detectable brightness variability on their radial velocity periods, supporting planetary-reflex motion as the cause of the radial velocity variability. HD 86081 shows no evidence of planetary transits in spite of a 17.6% transit probability. We have too few photometric observations to detect or rule out transits for HD 224693.
The field-assisted turn-off thyristor: a regenerative device with voltage-controlled turn-off

A solid-state switching element, the field-assisted turn-off (FATO) thyristor, has been developed. This is a regenerative device, which implies that it is capable of carrying very large current densities, with a very small forward voltage drop when it is in its on-state. Most regenerative devices cannot be turned off with a control signal; however, the structure of the FATO thyristor allows it to be switched off by applying a voltage to a high impedance, insulated-gate terminal. This device can also be fabricated with an insulated-gate turn-on structure, so that it is fully switchable using only low-current control signals. The design, fabrication, and characterization of the FATO thyristor are described. >
Contributions to the Muon's Anomalous Magnetic Moment from a Hidden Sector

Abstract The measurement of the anomalous magnetic moment of the muon provides a stringent test of the standard model and of any physics that lies beyond it. There is currently a deviation of 3.1σ between the standard model prediction for the muon’s anomalous magnetic moment and its experimental value. We calculate the contribution to the anomalous magnetic moment in theories where the muon couples to a particle in a hidden sector (that is, uncharged under the standard model) and a connector (which has nontrivial standard model gauge and hidden sector quantum numbers).
Space-efficient algorithms for approximating polygonal curves in two-dimensional space

Given an n-vertex polygonal curve P = [p1, p2, …, pn] in the 2-dimensional space R2, we consider the problem of approximating P by finding another polygonal curve such that the vertex sequence of P′ is an ordered subsequence of the vertices along P. The goal is to either minimize the size m of P′ for a given error tolerance ∊ (called the min-# problem), or minimize the deviation error ∊ between P and P′ for a given size m of P′ (called the min-∊ problem). We present useful techniques and develop efficient algorithms for solving the 2-D min-# and min-∊ problems under two commonly-used error criteria for curve approximations. Our algorithms improve substantially the space bounds of the previously best known results on the same problems while maintain the same time bounds as those of the best known algorithms. We further show that our 2-D techniques can be used to improve the time and space bounds for a special case of the 3-D min-# and min-∊ problems.
Single-Electron-Spin Measurements in Si-Based Semiconductor Nanostructures

In this chapter, we review the experimental efforts that focus on the measurement of single-electron spins in two particular Si-based semiconductor nanostructure systems. First, we describe experiments in a real transistor structure (i.e., a submicrometer commercial Si field effect transistor) in which the source/drain channel is used to electrically detect the spin states of an adjacent single paramagnetic spin center. This transistor structure is similar to a number of proposed spin-based qubit architectures that can be used as a potential quantum information processor. Second, we describe the effort to fabricate similar devices in specially designed semiconductor structures that promise greater control over electron spin, the ability to entangle two spins, and to eventually build a scalable quantum processor. In these engineered structures, quantum dots are created by metallic gates patterned over a 2D electron gas in a strained silicon-germanium heterostructure. In addition to the discussion of fabrication issues, we also show examples of single-electron-spin measurements in the few-electron regime of quantum dots.
Controlling manifold covers of orbifolds

In this article we prove a generalization of Selberg's lemma on the existence of torsion free, finite index subgroups of arithmetic groups. Some of the geometric applications are the resolution a conjecture of Nimershiem and answers to questions of Long-Reid and the author.
Citizen restraints on “Leviathan” government: transition politics in Bulgaria

Abstract Standard theories of government in transition countries [Olson, M., Jr., 1995. Why the transition from communism is so difficult. Eastern Economic Journal 21, 437–462.] regard politicians and bureaucracies as “bandits” who extract the maximum resources from the public. Extraction is limited when the bandit expects to maintain power for a longer period of time and when the public can resist. When “bandits” try to gain wealth quickly and then leave, it is hard for them to work together — they become “disorganized roving bandits.” In the transition, the public begins to act together to restrain the ability of the government to extract rents, changing the constraint faced by “bandits”. The paper uses these principles to analyze the politics of transition in Bulgaria. While some political actors extracted rents for their personal use, others followed traditional authoritarian principles, producing the leader's idea of the public good — a concept of government as Leviathan. Four episodes of transition policy are considered. In each, the government followed policies that led to its collapse under citizen resistance. Either governments were too “disorganized” to carry out utility-maximizing policies, or they underestimated the willingness of the public to resist their policies.
Global Crisis and Latin America

Author(s): Robinson, William I. | Abstract: This essay examines Latin America’s experience in the crisis and restructuring of world capitalism from the 1970s into the twenty first century, with particular emphasis on the neo-liberal model, social conflicts and institutional quagmires that have engulfed the region, and the rise of a new resistance politics. The empirical and analytical sections look at: Latin America’s changing profile in the global division of labour; the domination of speculative finance capital; the continued debt crisis, its social effects and political implications; capital–labour restructuring, the spread of informalisation and the new inequality; the passage from social explosions to institutional crises; the new popular electoral politics and the fragility of the neo-liberal state. These issues are approached through the lens of global capitalism theory. This theory sees the turn-of-century global system as a new epoch in the history of world capitalism, emphasising new patterns of power and social polarisation worldwide and such concepts as a transnational accumulation, transnational capitalists and a transnational state. Finally, the essay argues that global capitalism faces a twin crisis in the early twenty first century, of overaccumulation and of legitimacy, and explores the prospects for social change in Latin America and worldwide.
Topological strings on noncommutative manifolds

We identify a deformation of the N=2 supersymmetric sigma model on a Calabi–Yau manifold X which has the same effect on B-branes as a noncommutative deformation of X. We show that for hyperkahler X such deformations allow one to interpolate continuously between the A-model and the B-model. For generic values of the noncommutativity and the B-field, properties of the topologically twisted sigma-models can be described in terms of generalized complex structures introduced by N. Hitchin. For example, we show that the path integral for the deformed sigma-model is localized on generalized holomorphic maps, whereas for the A-model and the B-model it is localized on holomorphic and constant maps, respectively. The geometry of topological D-branes is also best described using generalized complex structures. We also derive a constraint on the Chern character of topological D-branes, which includes A-branes and B-branes as special cases.
Palladium-Catalyzed α-Arylation of Carbonyl Compounds and Nitriles

The palladium-catalyzed α-arylation of ketones has become a useful and general synthetic method. In this process, an enolate is generated from a ketone and base in the presence of an aryl halide, and a palladium catalyst couples this enolate with the aryl halide. With the advent of new catalysts composed of sterically hindered, electron-rich alkylphosphine and N-heterocyclic carbene ligands, this process now encompasses a broad range of enolates and related anions, including those derived from amides, esters, aldehydes, nitriles, malonates, cyanoesters, nitroalkanes, sulfones, and lactones. In the proposed mechanism for this reaction, the carbon−carbon bond of the product is formed by reductive elimination from an arylpalladium enolate intermediate. The structures and reactions of arylpalladium complexes of enolate, cyanoalkyl, and malonate ions have been studied to determine how the binding mode and electronic and steric parameters influence the rate and mechanism of reductive elimination.
Spatial Mismatch or Automobile Mismatch? An Examination of Race, Residence and Commuting in US Metropolitan Areas.

This paper uses data from the metropolitan samples of the American Housing Survey in 1977-78 and 1985 to examine the commute patterns of whites, blacks and Hispanics in US metropolitan areas, with a particular focus on the commutes of workers living in predominantly minority residential areas. Overall, the commute patterns of white and minority workers appear to be converging rather than diverging over time, even among low-skilled workers. Contrary to the spatial mismatch hypothesis, black and Hispanic workers living in minority areas had both shorter commutes and commutes that increased more slowly between 1977-78 and 1985 compared to workers in other areas. Further, a longitudinal analysis shows that the average commute times of non-moving minority workers in predominantly minority areas decreased during the study period. We find no evidence in these commuting data to support the spatial mismatch hypothesis.
Turbulence analysis of an experimental flux-rope plasma

We have previously generated elongated Taylor double-helix flux-rope plasmas in the SSX MHD wind tunnel. These plasmas are remarkable in their rapid relaxation (about one Alfv´ en time) and their description by simple analytical Taylor force-free theory despite their high plasma β and high internal flow speeds. We report on the turbulent features observed in these plasmas including frequency spectra, autocorrelation function, and probability distribution functions of increments. We discuss here the possibility that the turbulence facilitating access to the final state supports coherent structures and intermittency revealed by non-Gaussian signatures in the statistics. Comparisons to a Hall-MHD simulation of the SSX MHD wind tunnel show similarity in several statistical measures.
New synthesis of 2-aminobicyclo[2.1.1]hexane-2,5-dicarboxylic acid-I (ABHxD-I), a potent metabotropic receptor agonist

Abstract A new versatile synthesis of racemic ABHxD-I, a potent mGluR agonist, is presented. The synthesis was achieved by means of a Wolff rearrangement, which converted a 3-diazobicyclo[2.2.1]heptan-2-one into a bicyclo[2.1.1]hexane derivative.
Alzheimer's Disease Amyloid-β Links Lens and Brain Pathology in Down Syndrome

Down syndrome (DS, trisomy 21) is the most common chromosomal disorder and the leading genetic cause of intellectual disability in humans. In DS, triplication of chromosome 21 invariably includes the APP gene (21q21) encoding the Alzheimer's disease (AD) amyloid precursor protein (APP). Triplication of the APP gene accelerates APP expression leading to cerebral accumulation of APP-derived amyloid-β peptides (Aβ), early-onset AD neuropathology, and age-dependent cognitive sequelae. The DS phenotype complex also includes distinctive early-onset cerulean cataracts of unknown etiology. Previously, we reported increased Aβ accumulation, co-localizing amyloid pathology, and disease-linked supranuclear cataracts in the ocular lenses of subjects with AD. Here, we investigate the hypothesis that related AD-linked Aβ pathology underlies the distinctive lens phenotype associated with DS. Ophthalmological examinations of DS subjects were correlated with phenotypic, histochemical, and biochemical analyses of lenses obtained from DS, AD, and normal control subjects. Evaluation of DS lenses revealed a characteristic pattern of supranuclear opacification accompanied by accelerated supranuclear Aβ accumulation, co-localizing amyloid pathology, and fiber cell cytoplasmic Aβ aggregates (~5 to 50 nm) identical to the lens pathology identified in AD. Peptide sequencing, immunoblot analysis, and ELISA confirmed the identity and increased accumulation of Aβ in DS lenses. Incubation of synthetic Aβ with human lens protein promoted protein aggregation, amyloid formation, and light scattering that recapitulated the molecular pathology and clinical features observed in DS lenses. These results establish the genetic etiology of the distinctive lens phenotype in DS and identify the molecular origin and pathogenic mechanism by which lens pathology is expressed in this common chromosomal disorder. Moreover, these findings confirm increased Aβ accumulation as a key pathogenic determinant linking lens and brain pathology in both DS and AD.
Resistivity of Graphene Nanoribbon Interconnects

Graphene nanoribbon (GNR) interconnects are fabricated, and the extracted resistivity is compared to that of Cu. It is found that the average resistivity at a given linewidth(18 nm < W< 52 nm) is about three times that of a Cu wire, whereas the best GNR has a resistivity that is comparable to that of Cu. The conductivity is found to be limited by impurity scattering as well as line-edge roughness scattering; as a result, the best reported GNR resistivity is three times the limit imposed by substrate phonon scattering. This letter reveals that even moderate-quality graphene nanowires have the potential to outperform Cu for use as on-chip interconnects.
Acceptorless Photocatalytic Dehydrogenation for Alcohol Decarbonylation and Imine Synthesis

It has come to light: Renewed interest in conversions of highly oxygenated materials has motivated studies of the organometallic-catalyzed photocatalytic dehydrogenative decarbonylation of primary alcohols into alkanes, CO, and H2 (see scheme). Methanol, ethanol, benzyl alcohol, and cyclohexanemethanol are readily decarbonylated. The photocatalysts are also active for amine dehydrogenation to give N-alkyl aldimines and H2.
Decentralized Control of Active Vehicle Suspensions With Preview

In this paper, decentralized control of active vehicle suspensions with preview of road irregularities is considered using a two-degree-of-freedom vehicle model. It is shown that by taking advantage of the separation between the eigenvalues of the slow subsystem representing the body mode, and the fast subsystem corresponding to the wheel mode, the design of the preview controller can be decoupled. Since decentralized preview controllers are synthesized independently for two single-degree-of-freedom systems, analytical solutions are obtained. The results of the analysis and simulations demonstrate that the performance of the system with the proposed controller is comparable to that of the optimal preview controller based on a fully interconnected system.
Carry-over round robin: a simple cell scheduling mechanism for ATM networks

We propose a simple mechanism named carry-over round robin (CORR) for scheduling cells in asynchronous transfer mode networks. We quantify the operational complexity of CORR scheduling and show that it is comparable to that of a simple round-robin scheduler. We then show that, albeit its simplicity, CORR is very competitive with much more sophisticated and significantly more complex scheduling disciplines in terms of performance. We evaluate the performance of CORR using both analysis and simulation, We derive analytical bounds on the worst case end-to-end delay achieved by a CORR scheduler for different traffic arrival patterns. Using traffic traces from MPEG video streams, we compare the delay performance of CORR with that of packet-by-packet generalized processor sharing (PGPS) and stop-and-go (SG). Our results show that, in terms of delay performance, CORR compares favorably with both PGPS and SG. We also analyze the fairness properties of CORR and show that it achieves near perfect fairness.
Critical Groups of Simplicial Complexes

We generalize the theory of critical groups from graphs to simplicial complexes. Specifically, given a simplicial complex, we define a family of abelian groups in terms of combinatorial Laplacian operators, generalizing the construction of the critical group of a graph. We show how to realize these critical groups explicitly as cokernels of reduced Laplacians, and prove that they are finite, with orders given by weighted enumerators of simplicial spanning trees. We describe how the critical groups of a complex represent flow along its faces, and sketch another potential interpretation as analogues of Chow groups.
The New Diversification: Open Your Eyes to Alternatives

During the 2008 financial crisis, many portfolios considered widely diversified failed to fulfill their expected function of protecting against large drawdowns. Historically, correlations among various types of stocks and bonds have usually increased during financial shocks, but the diversification shortcomings of standard portfolio allocations still surprised investors. Six years later, managers have a more sophisticated understanding of portfolio drawdown risk and how to mitigate it through diversification. In this article, the author advocates a focus on the risk exposures within a portfolio and inclusion of risk diversifiers—often sourced through so-called alternatives—to design portfolios more resistant to volatility spikes and major shocks.