cssi/SciSciGPT-SciSciNet huggingface dataset:
Compensation to a department of medicine and its faculty members for the teaching of medical students and house staff

Background Changes in the organization and financing of health care threaten to alter the prevailing system of financing the teaching of medical students and residents. Little information is available from private medical schools and teaching hospitals about the extent of teaching by faculty members or the mechanisms and levels of reimbursement for teaching. Methods We surveyed faculty members in the Department of Medicine at Columbia–Presbyterian Medical Center to ascertain the extent of their teaching activities. A standard number of hours was assigned to each activity, and the total number of teaching hours was calculated for each faculty member. Teaching of fellows and in continuing medical education programs was excluded. We also determined how much money the Department of Medicine received in payment for faculty members' teaching activities, and the sources of this compensation. Results In the 1992–1993 academic year, the 188 full-time faculty members spent a total of 46,086 hours teaching (mean [±S...
Precision Measurements of the Cluster Red Sequence using an Error Corrected Gaussian Mixture Model

The red sequence is an important feature of galaxy clusters and plays a crucial role in optical cluster detection. Measurement of the slope and scatter of the red sequence are affected both by selection of red sequence galaxies and measurement errors. In this paper, we describe a new error-corrected Gaussian Mixture Model for red sequence galaxy identification. Using this technique, we can remove the effects of measurement error and extract unbiased information about the intrinsic properties of the red sequence. We use this method to select red sequence galaxies in each of the 13,823 clusters in the maxBCG catalog, and measure the red sequence ridgeline location and scatter of each. These measurements provide precise constraints on the variation of the average red galaxy populations in the observed frame with redshift. We find that the scatter of the red sequence ridgeline increases mildly with redshift, and that the slope decreases with redshift. We also observe that the slope does not strongly depend on cluster richness. Using similar methods, we show that this behavior is mirrored in a spectroscopic sample of field galaxies, further emphasizing that ridgeline properties are independent of environment. These precise measurements serve as an important observational check on simulations and mock galaxy catalogs. The observed trends in the slope and scatter of the red sequence ridgeline with redshift are clues to possible intrinsic evolution of the cluster red sequence itself. Most importantly, the methods presented in this work lay the groundwork for further improvements in optically based cluster cosmology.
If people vote because they like to, then why do so many of them lie?

Of those eligible, about 40% do not vote in presidential elections. When asked, about a quarter of those nonvoters will lie to the survey takers and claim that they did. Increases in education are associated with higher voting rates and lower rates of lying overall, but with increased rates of lying conditional on not voting. This paper proposes a model of voter turnout in which people who claim to vote get praise from other citizens. Those who lie must bear the cost of lying. The model has a stable equilibrium with positive rates of voting, honest non-voting, and lying. Reasonable parameter changes produce changes in these proportions in the same direction as the changes actually observed across education levels. I argue that a model where people vote because they want to be known as voters provides a better explanation for observed voting behavior than does a model where people vote because they want to vote.
Acetylenic Vinyllithiums: Consecutive Cycloisomerization-[4 + 2] Cycloaddition Reactions.

Acetylenic vinyllithiums (2), which were generated from the corresponding acetylenic vinyl bromides (3) by low-temperature lithium−bromine exchange, cyclize on warming to give, following quench with water, isomerically pure conjugated bis-exocyclic 1,3-dienes (1) in good to excellent yield. Both five-membered and six-membered outer-ring dienes may be prepared: 5-exo closure of an acetylenic vinyllithium, which proceeds with total stereocontrol via syn-addition to give the E-isomer of a five-membered outer-ring diene, tolerates aryl-, silyl-, or alkyl-substituents at the distal acetylenic carbon; the corresponding 6-exo process is less facile and seems to be confined to substrates bearing an anion-stabilizing substituent, such as phenyl or trimethylsilyl, at the terminal acetylenic carbon. The highly reactive bis-exocyclic 1,3-dienes serve as precursors to polycyclic materials through subsequent Diels−Alder reaction with a wide variety of dienophiles. The consecutive exchange−cyclization−cycloaddition met...
A molecular orbital model for the electronic structure of transition metal atoms in silicate and aluminate alloys

Abstract A classification scheme that separates non-crystalline dielectrics into three groups with different amorphous morphologies reveals an approximately linear relationship between oxygen atom coordination and average bond ionicity. When applied to transition metal (TM) and rare earth (RE) lanthanide oxides, and their silicate and aluminate alloys, this approach demonstrates a correlation between stability against crystallization and oxygen atom coordination. It also provides a local bonding model for local molecular orbital calculations that are based on the coordination and symmetry of TM and RE atoms and the orbital energies of their oxygen neighbors. These calculations provide important insights into the electronic structure of TM and RE dielectrics, and in particular the role of atomic d-state energies in providing a scaling parameter for conduction band offset energies between gate dielectrics and the Si substrate.
Reaction of 2-Naphthylamine with Sodium Iodate/Sodium Sulfite: Synthesis of 2-Amino-1-iodonaphthalene

Abstract The reaction of 2-naphthylamine with NaIO3/Na2SO3/HCl yields exclusively 2-amino-1-iodonaphthalene and not regioisomer 2-amino-3-iodonaphthalene as was previously reported. The assigned structure is supported by spectroscopic data.
Adiabatic nonlinear waves with trapped particles. III. Wave dynamics

The evolution of adiabatic waves with autoresonant trapped particles is described within the Lagrangian model developed in Paper I, under the assumption that the action distribution of these particles is conserved, and, in particular, that their number within each wavelength is a fixed independent parameter of the problem. One-dimensional nonlinear Langmuir waves with deeply trapped electrons are addressed as a paradigmatic example. For a stationary wave, tunneling into overcritical plasma is explained from the standpoint of the action conservation theorem. For a nonstationary wave, qualitatively different regimes are realized depending on the initial parameter S, which is the ratio of the energy flux carried by trapped particles to that carried by passing particles. At S 1/2, the trapped-particle modulational instability (TPMI) develops, in contrast with the existing theories of the TPMI yet in agreement with the general sideband insta...
Discussion of “are executive stock options associated with future earnings?” ☆

Abstract Hanlon, Rajgopal, and Shevlin conclude that grant of stock options to executives is associated with a positive impact on future operating performance. This discussion comment examines the impact of endogeneity, model structure, and the choice of a benchmark model on this conclusion. While some results indicate that there is a position relation between stock option grants and operating performance, alternative econometric approaches produce distinctly different results.
Detecting embedded Horn structure in propositional logic

We show that the problem of finding a maximum renamable Horn problem within a propositional satisfiability problem is NP-hard but can be formulated as a set packing and therefore a maximum clique problem, for which numerous algorithms and heuristics have been developed.
Network Design with Weighted Players

We consider a model of game-theoretic network design initially studied by Anshelevich et al. (Proceedings of the 45th Annual Symposium on Foundations of Computer Science (FOCS), pp. 295–304, 2004), where selfish players select paths in a network to minimize their cost, which is prescribed by Shapley cost shares. If all players are identical, the cost share incurred by a player for an edge in its path is the fixed cost of the edge divided by the number of players using it. In this special case, Anshelevich et al. (Proceedings of the 45th Annual Symposium on Foundations of Computer Science (FOCS), pp. 295–304, 2004) proved that pure-strategy Nash equilibria always exist and that the price of stability—the ratio between the cost of the best Nash equilibrium and that of an optimal solution—is Θ(log k), where k is the number of players. Little was known about the existence of equilibria or the price of stability in the general weighted version of the game. Here, each player i has a weight w i ≥1, and its cost share of an edge in its path equals w i times the edge cost, divided by the total weight of the players using the edge. This paper presents the first general results on weighted Shapley network design games. First, we give a simple example with no pure-strategy Nash equilibrium. This motivates considering the price of stability with respect to α-approximate Nash equilibria—outcomes from which no player can decrease its cost by more than an α multiplicative factor. Our first positive result is that O(log w max )-approximate Nash equilibria exist in all weighted Shapley network design games, where w max is the maximum player weight. More generally, we establish the following trade-off between the two objectives of good stability and low cost: for every α=Ω(log w max ), the price of stability with respect to O(α)-approximate Nash equilibria is O((log W)/α), where W is the sum of the players’ weights. In particular, there is always an O(log W)-approximate Nash equilibrium with cost within a constant factor of optimal. Finally, we show that this trade-off curve is nearly optimal: we construct a family of networks without o(log w max / log log w max )-approximate Nash equilibria, and show that for all α=Ω(log w max /log log w max ), achieving a price of stability of O(log W/α) requires relaxing equilibrium constraints by an Ω(α) factor.
Synthesis and biological activity of C-4 and C-15 Aryl azide derivatives of anguidine

Abstract Potential trichothecene photoaffinity reagents were prepared by coupling either the C-4 or C-15 alcohols derived from anguidine with (3-azido-5-methoxyphenoxy) acetic acid, 4-(3-azido-5-methoxyphenoxy)butyric acid, or N-(3-azido-5-methoxyphenyl) N'-(carboxymethyl) urea. The C-15 anguidine deriviatives of (3-azido-5-methoxyphenoxy)acetic acid and (3-azido-4-iodo-5-methoxyphenoxy) acetic acid possessed protein synthesis inhibition activity comparable to that of anguidine itself in Chinese hamster ovary and African Green Monkey kidney cell lines.
Klazar trees and perfect matchings

Martin Klazar computed the total weight of ordered trees under 12 different notions of weight. The last and perhaps the most interesting of these weights, w"1"2, led to a recurrence relation and an identity for which he requested combinatorial explanations. Here we provide such explanations. To do so, we introduce the notion of a ''Klazar violator'' vertex in an increasing ordered tree and observe that w"1"2 counts what we call Klazar trees-increasing ordered trees with no Klazar violators. A highlight of the paper is a bijection from n-edge increasing ordered trees to perfect matchings of [2n]={1,2,...,2n} that sends Klazar violators to even numbers matched to a larger odd number. We find the distribution of the latter matches and, in particular, establish the one-summation explicit formula @?"k"="1^@?^n^/^2^@?(2k-1)!!^2{n+12k+1} for the number of perfect matchings of [2n] with no even-to-larger-odd matches. The proofs are mostly bijective.
On certain vanishing identities for Gromov-Witten invariants

In this paper we study certain vanishing identities for Gromov-Witten invariants conjectured by K. Liu and H. Xu. We will prove their conjectures when the summation range is big compared to the genus. In such cases, we actually obtained vanishing identities which are stronger than their conjectures. We also prove these conjectures in low genus cases.
Concise synthesis of indolizidines: total synthesis of (−)-coniceine

The Ti-mediated allylsilane addition to bicyclic lactams occurs with high stereoselectivity and combined with a ring closure metathesis provides the title compounds in high ee.
Simulation of the Magnetothermal Instability

In many magnetized, dilute astrophysical plasmas, thermal conduction occurs almost exclusively parallel to magnetic field lines. In this case, the usual stability criterion for convective stability, the Schwarzschild criterion, which depends on entropy gradients, is modified. In the magnetized long mean free path regime, instability occurs for small wavenumbers when (∂ P/∂z) (∂ ln T/∂ z) > 0, which we refer to as the Balbus criterion. We refer to the convective-type instability that results as the magnetothermal instability (MTI). We use the equations of MHD with anisotropic electron heat conduction to numerically simulate the linear growth and nonlinear saturation of the MTI in plane-parallel atmospheres that are unstable according to the Balbus criterion. The linear growth rates measured from the simulations are in excellent agreement with the weak field dispersion relation. The addition of isotropic conduction, e.g. radiation, or strong magnetic fields can damp the growth of the MTI and affect the nonlinear regime. The instability saturates when the atmosphere becomes isothermal as the source of free energy is exhausted. By maintaining a fixed temperature difference between the top and bottom boundaries of the simulation domain, sustained convective turbulence can be driven. MTI-stable layers introduced by isotropic conduction are used to prevent the formation of unresolved, thermal boundary layers. We find that the largest component of the time-averaged heat flux is due to advective motions as opposed to the actual thermal conduction itself. Finally, we explore the implications of this instability for a variety of astrophysical systems, such as neutron stars, the hot intracluster medium of galaxy clusters, and the structure of radiatively inefficient accretion flows.
A silicon-tethered allenic Pauson–Khand reaction

Abstract This manuscript describes a silicon-tethered Pauson–Khand reaction and subsequent cleavage of the resulting vinyl silane to afford functionalized alkylidene cyclopentenones. Altering the reaction conditions affords a selective reaction with either π-bond of the allene.
Income inequality and redistribution in post-industrial democracies: demographic, economic and political determinants

This article analyses the determinants of market income distribution and governmental redistribution. The dependent variables are Luxembourg Income Study data on market income inequality (measured by the Gini index) for households with a head aged 25–59 years and the per cent reduction in the Gini index by taxes and transfers. We test the generalizability of the Goldin–Katz hypothesis that inequality has increased in the USA because the country failed to invest sufficiently in education. The main determinants of market income inequality are (in order of size of the effect) family structure (single mother households), union density, deindustrialization, unemployment, employment levels and education spending. The main determinants of redistribution are (in order of magnitude) left government, family structure, welfare state generosity, unemployment and employment levels. Redistribution rises mainly because needs rise (that is, unemployment and single mother households increase), not because social policy becomes more redistributive.
Dynamic spatial replenishment of femtosecond pulses propagating in air

We present numerical simulations of nonlinear pulse propagation in air whereby an initial pulse is formed, absorbed by plasma generation, and subsequently replenished by power from the trailing edge of the pulse. This process can occur more than once for high-power input pulses and produce the illusion of long-distance propagation of one self-guided pulse.
THREE-VARIABLE MAHLER MEASURES AND SPECIAL VALUES OF MODULAR AND DIRICHLET L-SERIES

In this paper we prove that the Mahler measures of the Laurent polynomials (x+x−1)(y+y−1)(z+z−1)+k1/2, (x+x−1)2(y+y−1)2(1+z)3z−2−k, and x4+y4+z4+1+k1/4xyz, for various values of k, are of the form r1L′(f,0)+r2L′(χ,−1), where \(r_{1},r_{2}\in \mathbb{Q}\), f is a CM newform of weight 3, and χ is a quadratic character. Since it has been proved that these Mahler measures can also be expressed in terms of logarithms and 5F4-hypergeometric series, we obtain several new hypergeometric evaluations and transformations from these results.
Using VLBI to Probe the Orion KL Outflow on AU Scales

We present the first contemporaneous 43 and 86 GHz VLBI images of the v = 1, J = 2 → 1 and J = 1 → 0 SiO masers in the Orion KL nebula. Both maser species exhibit the same general morphology of earlier J = 1 → 0 maser images, which appear to trace the edges of a bipolar conical outflow. Surprisingly, the J = 2 → 1 masers form farther from the central protostar than the J = 1 → 0 masers, a fact not readily explained by current SiO maser pumping models. The average magnitude of offsets between corresponding regions of the two masing transitions is approximately 14% of the total radial extent of the SiO maser emission. This offset indicates that each transition must trace different physical conditions.
An Unexpected Bis-ligation of S-Nitrosothiols

A bis-ligation reaction of S-nitrosothiols using triaryl substituted phosphine-thioester substrates has been developed. This reaction converts unstable primary S-nitrosothiols to stable disulfide-iminophosphorane products in high yields under mild conditions. It can potentially be applied for the detection of S-nitrosation in protein systems.
Capping Amyloid β-Sheets of the Tau-Amyloid Structure VQIVYK with Hexapeptides Designed To Arrest Growth. An ONIOM and Density Functional Theory Study

We present ONIOM calculations using density functional theory (DFT) as the high and AM1 as the medium level that explore the abilities of different hexapeptide sequences to terminate the growth of a model for the tau-amyloid implicated in Alzheimer’s disease. We delineate and explore several design principles (H-bonding in the side chains, using antiparallel interactions on the growing edge of a parallel sheet, using all-d residues to form rippled interactions at the edge of the sheet, and replacing the H-bond donor N–H’s that inhibit further growth) that can be used individually and in combination to design such peptides that will have a greater affinity for binding to the parallel β-sheet of acetyl-VQIVYK-NHCH3 than the natural sequence and will prevent another strand from binding to the sheet, thus providing a cap to the growing sheet that arrests further growth. We found peptides in which the Q is replaced by an acetyllysine (aK) residue to be particularly promising candidates, particularly if the rev...
Introduction to the Abrupt Wing Stall (AWS) Program

The Abrupt Wing Stall (AWS) Program has addressed the problem of uncommanded, transonic lateral motions, such as wing drop, with experimental, computational, and simulation tools. Background to the establishment of the AWS program is given as well as program objectives. In order to understand the fundamental flow mechanisms that caused the undesirable motions for a pre-production version of the F/A-18E, steady and unsteady flow field details were gathered from dedicated transonic wind-tunnel testing and computational studies. The AWS program has also adapted a free-toroll (FTR) wind-tunnel testing technique traditionally used for low-speed studies of lateral dynamic stability to the transonic flow regime. This FTR capability was demonstrated first in a proof-of-concept study and then applied to an assessment of four different aircraft configurations. Figures of merit for static testing and for FTR testing have been evaluated for two configurations that demonstrated wing drop susceptibility during full-scale flight conditions (the pre-production F/A-18E and the AV-8B at the extremes of its flight envelope) and two configurations that do not exhibit wing drop (the F/A-18C and the F-16C). Design insights have been obtained from aerodynamic computational studies of the four aircraft configurations and from computations quantifying the impact of the various geometric wing differences between the F/A-18C and the F/A-18E wings. Finally, the AWS program provides guidance for assessing, in the simulator, the impact of experimentally determined lateral activity on flight characteristics before going to flight. SYMBOLS AND ABBREVIATIONS
Revised reference model for nitric acid

A nearly global set of data on the nitric acid distribution was obtained for seven months by the Limb Infrared Monitor of the Stratosphere (LIMS) experiment on the Nimbus 7 spacecraft. The evaluation of the accuracy, precision, and resolution of these data is described, and a description of the major features of the nitric acid distributions is presented. The zonal mean for nitric acid is distributed in a stratospheric layer that peaks near 30 mb, with the largest mixing ratios occurring in polar regions, especially in winter.
Parity in professional sports when revenues are maximized

Abstract There are two major hypotheses regarding the talent distribution among the teams that would maximize the total revenues in a sports league; dominant teams versus parity. This paper examines the revenue structure of National Football League and proposes policy recommendations regarding talent distribution among the teams. By using a unique, rich data set on game day stadium attendance and TV ratings we are able to measure the total demand as a function of involved teams' talent levels. Reduced form regression results indicate that TV viewers are more interested in close games, on the other hand stadium attendees are more interested in home team's dominance, in other words stadium demand and TV demand work against each other. We therefore propose a policy that promotes slight parity among the teams where big market teams have a slight advantage over the others. Total revenues of the league are maximized under such policy.
Synthesis of 12 Stereochemically and Structurally Diverse C-Trisaccharides

Cell surface carbohydrates and their analogs may be used to study the cellular interactions responsible for adhesion to pathogenic bacteria, viruses, and other cells and may represent leads for drug discovery. We have generated 12 C-trisaccharides (7−18) as potential inhibitors for the cell surface proteins of the bacterium Helicobactor pylori. The strategy used has resulted in the generation of C-trisaccharides structures that are represented by the formula Fuc-α(1-2)-hexose-(1-3)-GlcNAc where each of the 12 compounds possesses a central sugar that has been systematically replaced with stereochemically diverse structures, including d and l sugars, through de novo synthesis. This approach relies upon an organometallic coupling of terminal monosaccharides 19 and 20 to prepare a “disaccharide” in a convergent manner. This intermediate is then divergently derivatized to form a variety of structural analogs about the central hexose. For the separable compounds, the assignment of stereochemistry was done using...
Ligand and metal effects on the reactivity of metal carbonyls

Abstract The reactivity of metal carbonyl complexes is surveyed. The effect of charge, electron count, row and electronic configuration of the metal are examined for mononuclear carbonyls and more limited information is examined for metal clusters. Ligand effects are also examined for the metal carbonyls. The reactivity of metal carbonyl complexes changes by at least 15 orders of magnitude. This paper provides a framework for understanding such a range of reactivity.
The wave equation on asymptotically anti de Sitter spaces

In this paper we describe the behavior of solutions of the Klein–Gordon equation, (□g+λ)u=f, on Lorentzian manifolds (X∘,g) that are anti de Sitter-like (AdS-like) at infinity. Such manifolds are Lorentzian analogues of the so-called Riemannian conformally compact (or asymptotically hyperbolic) spaces, in the sense that the metric is conformal to a smooth Lorentzian metric ĝ on X, where X has a nontrivial boundary, in the sense that g=x−2ĝ, with x a boundary defining function. The boundary is conformally timelike for these spaces, unlike asymptotically de Sitter spaces studied before by Vasy and Baskin, which are similar but with the boundary being conformally spacelike. Here we show local well-posedness for the Klein–Gordon equation, and also global well-posedness under global assumptions on the (null)bicharacteristic flow, for λ below the Breitenlohner–Freedman bound, (n−1)2∕4. These have been known before under additional assumptions. Further, we describe the propagation of singularities of solutions and obtain the asymptotic behavior (at ∂X) of regular solutions. We also define the scattering operator, which in this case is an analogue of the hyperbolic Dirichlet-to-Neumann map. Thus, it is shown that below the Breitenlohner–Freedman bound, the Klein–Gordon equation behaves much like it would for the conformally related metric, ĝ, with Dirichlet boundary conditions, for which propagation of singularities was shown by Melrose, Sjostrand and Taylor, though the precise form of the asymptotics is different.
Taut foliations in surface bundles with multiple boundary components

Let M be a fibered 3-manifold with multiple boundary components. We show that the fiber structure of M transforms to closely related transversely oriented taut foliations realizing all rational multislopes in some open neighborhood of the multislope of the fiber. Each such foliation extends to a taut foliation in the closed 3-manifold obtained by Dehn filling along its boundary multislope. The existence of these foliations implies that certain contact structures are weakly symplectically fillable. Any closed, orientable 3-manifold can be realized by Dehn filling a 3-manifold which is fibered over S 1 [Alexander 1920; Myers 1978]. In other words, any closed oriented 3-manifold can be realized by Dehn filling a 3-manifold M0, where M0 has the form of a mapping torus M0D ST 0; 1U= ; where S is a compact orientable surface with nonempty boundary and is an equivalence relation given by .x; 1/ .h.x/; 0/ for some orientation-preserving homeomorphism hV S! S which fixes the components of@S setwise. Although we shall not appeal to this fact in this paper, it is interesting to note that it is possible to assume that h is pseudo-Anosov [Colin and Honda 2008] and hence M0 is hyperbolic [Thurston 1988]. It is also possible to assume that S has positive genus. Any nonorientable closed 3-manifold admits a double cover of this form. Taut codimension-one foliations are topological objects which have proved very useful in the study of 3-manifolds. The problem of determining when a 3-manifold contains a taut foliation appears to be a very difficult one. A complete classification exists for Seifert fibered manifolds [Brittenham 1993; Eisenbud et al. 1981; Jankins and Neumann 1985; Naimi 1994], but relatively little is known for the case of hyperbolic 3-manifolds. There are many partial results demonstrating existence
In situ TEM study of ion-beam-induced amorphization of complex silicate structures

Abstract The in situ transmission electron microscopy (TEM) with ion-irradiation technique has been used for the first time to study the radiation-induced amorphization (metamictization) process of naturally occurring silicates: neptunite [Na2KLi(Fe,Mn)2Ti2(SiO3)8], titanite (CaTiSiO5), gadolinite (REE2FeBe2Si2O10), zircon (ZrSiO4) and olivine [(Mg,Fe)2SiO4]. These phases were irradi 1.5 MeV Kr+ ions in the Argonne HVEM-Tandem facility at room temperature with the electron diffraction pattern monitored in situ. The critical doses required for amorphization of the electron transparent thickness of neptunite, titanite, gadolinite, zircon and olivine have been determined to be 1.7, 2.0, 2.3, 4.8 and 6.0 × 1014 ions/cm2, respectively. The results show a correlation between amorphization dose and the chemical and structural complexity of these five phases. The most complex structure (e.g. neptunite) becomes amorphous at the lowest critical dose. The critical amorphization dose also increases with the increasing melting temperature of the minerals.
ARITHMETIC QUANTUM UNIQUE ERGODICITY FOR SYMPLECTIC LINEAR MAPS OF THE MULTIDIMENSIONAL TORUS

We look at the expectation values for quantized linear symplectic maps on the multidimensional torus and their distribu- tion in the semiclassical limit. We construct super-scars that are stable under the arithmetic symmetries of the system and localize on invariant manifolds. We show that these super-scars exist only when there are isotropic rational subspaces, invariant under the linear map. In the case where there are no such scars, we com- pute the variance of the fluctuations of the matrix elements for the desymmetrized system, and present a conjecture for their limiting distributions.
Reading with central field loss: number of letters masked is more important than the size of the mask in degrees.

When the center of a readers, visual field is blocked from view, reading rates decline and eye movement patterns change. This is true whether the central visual field is blocked artificially (i.e. a mask) or through disease (e.g. a retinal scotoma due to macular degeneration). In past studies, when mask size was defined in terms of the number of letters masked from view, reading rates declined sharply as number of letters masked increased. Patients with larger central scotomas (in degrees of visual angle) also read slower. We sought to determine whether number of letters masked or size of the mask in degrees is the predominant factor affecting reading rates and eye movement behavior. By matching number of letters masked across several mask sizes (and compensating for reduced acuity in the periphery), we found that number of letters masked is the more important factor until mask size is quite large (> or = -7.5 degrees) and number of letters masked from view is more than seven.
Structure and function of DNA photolyase and cryptochrome blue-light photoreceptors.

1. Electron Donor 2223 2. Electron Transfer Path 2225 3. Electron Transfer Mechanism 2226 4. Physiological Relevance 2226 D. Radical Reactions in Photolyase 2226 E. “Dark Function” of Photolyase 2227 F. Regulation of Photolyase 2227 III. (6−4) Photolyase 2228 IV. Cryptochromes 2230 A. Structure 2231 B. Function 2231 1. Circadian Rythm 2231 2. Mammalian Circadian System 2231 3. Cryptochromes and the Circadian Clock 2232 V. Perspectives 2234 VI. Acknowledgment 2235 VII. References 2235
Partial median nerve entrapment in the distal arm because of an accessory bicipital aponeurosis

We present a newly described entrapment of the median nerve caused by compression in the distal arm because of an accessory bicipital aponeurosis. It is characterized by the paresis or paralysis of muscles innervated by the anterior interosseous branch of the median nerve-the flexor pollicis longus, the flexor digitorum profundus, and the pronator quadratus-as well as other more proximal median nerve innervated muscles, namely, the pronator teres and flexor carpi radialis. Sensibility is intact. The site of the Tinel's sign in the distal arm and the clinical appearance of an accessory bicipital aponeurosis help to localize the lesion. Electrodiagnostic studies are also important in establishing the site of the entrapment. The clinical and surgical findings are correlated with the internal topography of the median nerve at its site of compression. It is important to differentiate this syndrome from the classic anterior interosseous syndrome and other nerve entrapments at the elbow and arm. Surgical exploration is indicated if there is no clinical or electromyographic improvement in three to four months after the onset of symptoms.
A 12b 50MS/s 2.1mW SAR ADC with redundancy and digital background calibration

A 12-bit 50MS/s SAR ADC implemented in 65nm CMOS technology is presented. The design employs redundancy to relax the DAC settling requirement and to provide sufficient room for errors such that the static nonlinearity caused by capacitor mismatches can be digitally removed. The redundancy is incorporated into the design using a tri-level switching scheme and our modified split-capacitor array to achieve the highest switching efficiency while still preserving the symmetry in error tolerance. A new code-density based digital background calibration algorithm that requires no special calibration signals or additional analog hardware is also developed. The calibration is performed by using the input signal as stimulus and the effectiveness is verified both in simulation and through measured data. The prototype achieves a 67.4dB SNDR at 50MS/s, while dissipating 2.1mW from a 1.2V supply, leading to FoM of 21.9fJ/conv.-step at Nyquist frequency.
The predictability of real exchange rate changes in the short and long run

Abstract Nominal exchange rates do not move to offset differences in inflation rates on a month to month, quarter to quarter, or even year to year basis, resulting in sizable real exchange rate changes. Are these changes predictable? We address this question in three ways. First, we describe a variety of tests of predictability and explain how the different tests are related. Next, we implement the tests for the U.S. dollar relative to four currencies and find statistically significant evidence that real exchange rate changes are predictable. Finally, we examine whether the predictability is of an economically interesting magnitude.
Electron‐phonon interaction in correlated electronic systems: polarons and the formation of orbital ordering

The properties of a dilute electron gas, coupled to the latti ce degrees of freedom, are studied and compared with the properties of an electron gas at half-filling, where spinless fermions with two orbitals per lattice site are considered. The simplest model which includes both the local electron-lattice interaction of the Jahn-Teller type and the electronic correlations is the E �-Jahn-Teller-Hubbard model. We analyze the formation and stability of Jahn-Teller polarons and bipolarons, respectively. Our approach is based on a hopping expansion in the strong-coupling regime. The results are compared with recently published findings for the Hubbard-Holstein model [1, 2]. The special case of the Jahn-Teller-Hubbard model at half-filling is mapped on a spin-1/2 Heisenberg model with phonon-dependent coupling constants. This has been derived within a projection formalism that provides a continued-fraction representation of the Green’s function. We study the exact solution for two and three particles and compare it with the effective theory on the infinite lattice with one particle per site.
Optimal Control of a Magnetically Suspended Under Actuated Robot for Swing-Up Motion

This paper describes the analysis, design, and implementation of an under-actuated robot control system for swing up motion. The robot, called the “Mag-Foot” robot, uses permanent magnets to adhere to steel surfaces. This robot uses a novel tilting foot design for locomotion and can swing over small obstacles using an underactuated swinging motion. Since the robot can only adhere to the surface using limited (and relatively small) magnetic forces, it may fall down due to the reaction forces caused by the swing-up motion. To prevent failure, an optimal swing up trajectory is designed so that the maximum reaction force during the trajectory is minimized. The trajectories are parameterized using sigmoids and are determined by solving the dynamic equations as a 2 point boundary value problem. Finally, experiments are performed to evaluate the validity of this approach. The results of these experiments are promising and illustrate the validity of our approach.Copyright © 2009 by ASME
Bowling Alone: a review essay

Abstract This paper is a critical review of Robert Putnam’s influential analysis of social capital in America: Bowling Alone. The review argues that Bowling Alone reflects many of the strengths and weaknesses of the social capital literature. Like this literature, Bowling Alone describes a remarkable number of facts concerning community life in America. At the same time, the book suffers from many of the conceptual problems and empirical weaknesses that have plagued the social capital literature. I conclude that Bowling Alone does not succeed in establishing the importance of social capital in understanding various socioeconomic phenomena it purports to explain.
Evidence of a Curved Synchrotron Spectrum in the Supernova Remnant SN 1006

A joint spectral analysis of some Chandra ACIS X-ray data and Molonglo Observatory Synthesis Telescope radio data was performed for 13 small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut off power law, with one notable difference: The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the synchrotron spectrum of SN 1006 seems to flatten with increasing energy. The effective power-law index of the electron spectrum is 2.2 at 1 GeV (i.e., radio synchrotron-emitting momenta) and 2.0 at about 10 TeV (i.e., X-ray synchrotron-emitting momenta). This amount of change in the index is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant. The evidence of spectral curvature implies that cosmic rays are dynamically important instead of being "test" particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest-energy electrons. The critical frequency seems to vary along the northeastern rim, with a maximum value of 1.1+1.0−0.5 × 1017 Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of ~4.5-21 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km s−1. Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 1017 Hz.
Higgsstrahlung from R-hadrons

If R-hadrons are discovered at the LHC, investigation of their properties will be of paramount importance. One important question is how much of the R-hadron mass is due to electroweak symmetry breaking, i.e. the coupling of the Higgs to R-hadrons. In this paper we show that in models where the Higgs has a sizable coupling to R-hadrons we can readily observe Higgs production in association with a pair of R-hadrons (“Higgsstrahlung”). This process can be used to distinguish between different models of R-hadrons. It may be the discovery mode of the Higgs for low mass Higgs bosons, and provides a low-background Higgs sample to study $ h \to \overline b b $ .
Mechanisms for incorporation of hydrogen in and on terrestrial planetary surfaces

Abstract Storage of hydrogen atoms in or on a planetary surface can take place via several different mechanisms. If the hydrogen atom reacts to form a hydroxyl (OH) group or water molecule, an absorption band near 3 μm will be present. Many possible mechanisms for sequestering atomic hydrogen are discussed: internal hydrogen in the form of non-structural OH and H 2 O in nominally-anhydrous minerals, structural OH in minerals, structural H 2 O in minerals, H 2 O in fluid inclusions, and OH and H 2 O in glasses; bulk H 2 O as either liquid water or ice; and surficial hydrogen that is either physisorbed as H 2 O, chemisorbed as an H 2 O surface complex, or chemically-bound as an OH group on surface terminal sites and grain boundary regions. Understanding the spectroscopic distinctions among these various phenomena is of critical importance in constraining both the evolution of planetary interiors and the cycling of water on planetary surfaces. Proper interpretation of 3-μm bands in reflectance spectra is shown to depend upon the relative contributions from surficial vs. interior hydrogen, which vary with effective surface area (i.e., the grain size and surface roughness) and the volume sampled by the spectrometer.
Utilization of Mobile VLBI for Geodetic Measurements

Three mobile VLBI systems have been fabricated under the direction of the Jet Propulsion Laboratory of the California Institute of Technology for the NASA Crustal Dynamics Project. These include the 9-m-diameter MV-1 telescope, the 3.6-m MV-2 telescope, and the 5-m-diameter MV-3 telescope. Since 1980, mobile systems have been operated in conjunction with several fixed-base stations in the Western United States as part of a geodetic survey program determining relative motions and regional strain fields near the tectonic plate boundaries in California and Alaska. In this paper, we present a description of the three mobile systems and the environment in which they must function. The inherent accuracy of moble VLBI measurements is assessed, based on a considcration of major sources of error. Some recent results are presented. which serve to illustrate various aspects of the error model and are of geodetic interest as they span the broad region surrounding the surface trace of the San Andreas Fault. These results indicate that baseline measurements utilizing the current mobile VLBI systems have attained an accuracy of 2 cm or better in the horizontal plane. Since average geological rates of horizontal motion are of order 5 cm/year across the plate boundary regions being studied, it is likely that crustal motions, will be detected within the next few years, provided they are presently occurring at the geological rates.
Olefin Metatheses and Related Reactions Initiated by Carbene Derivatives of Metals in Low Oxidation States

Experiments carried out 24 years ago with tantalum carbenes have led to the much cited hypothesis that metals (other than ruthenium) must be in their highest oxidation states for their carbene derivatives to initiate olefin metatheses. The hypothesis legitimizes the uniqueness of high-oxidation-state molybdenum and tungsten carbenes as effective initiators, and it means that the Fischer tungsten carbenes that even earlier were found to initiate olefin metatheses and related transformations must be oxidized before they can be effective. The newer initiators have been termed "well-defined", the older "ill-defined". But what does the evidence show?
A criterion for weak convergence on Berkovich projective space

We give a criterion for the weak convergence of unit Borel measures on the N-dimensional Berkovich projective space $${{\bf P}^{N}_K}$$ over a complete non-archimedean field K. As an application, we give a sufficient condition for a certain type of equidistribution on $${{\bf P}^{N}_K}$$ in terms of a weak Zariski-density property on the scheme-theoretic projective space $${{\mathbb P}^N_{\tilde{K{}_{\vphantom{0}}}}}$$ over the residue field $${\tilde{K}}$$ . As a second application, in the case of residue characteristic zero we give an ergodic-theoretic equidistribution result for the powers of a point a in the N-dimensional unit torus $${{\mathbb T}^N_K}$$ over K. This is a non-archimedean analogue of a well-known result of Weyl over $${\mathbb C}$$ , and its proof makes essential use of a theorem of Mordell-Lang type for $${{\mathbb G}_m^N}$$ due to Laurent.
Energy confinement scaling in the low aspect ratio National Spherical Torus Experiment (NSTX)

Systematic and statistical studies have been conducted in order to develop an understanding of the parametric dependences of both the global and thermal energy confinement times at low aspect ratio in high power National Spherical Torus Experiment discharges. The global and thermal confinement times of both L- and H-mode discharges can exceed values given by H-mode scalings developed for conventional aspect ratio. Results of systematic scans in the H-mode indicate that the confinement times exhibit a nearly linear dependence on plasma current and a power degradation weaker than that observed at conventional aspect ratio. In addition, the dependence on the toroidal magnetic field is stronger than that seen in conventional aspect ratio tokamaks. This latter trend is also evident in statistical analyses of the available dataset. These statistical studies also indicate a weaker parametric dependence on plasma current than found in the systematic scans, due to correlations among the predictor variables. Regressions based on engineering variables, when transformed to dimensionless physics variables, indicate that the dependence of BτE on βt can range from being negative to null. Regressions based directly on the dimensionless physics variables are inexact because of large correlations among these variables. Scatter in the confinement data, at otherwise fixed operating parameters, is found to be due to variations in ELM activity, low frequency density fluctuations and plasma shaping.
Nonlinear dynamics of aeroelastic systems

Aeroelastic systems are those that involve the coupled interaction between a convecting fluid and a flexible elastic structure. The nonlinear dynamical response of such systems is known to encounter limit cycle oscillations (LCO) in certain flight regimes and relatively simple experimental wind tunnel models have been designed to exhibit LCO as well. In the present paper, the results of these wind tunnel experiments are discussed and compared to comparable results from mathematical models. The physical models include (1) an airfoil and a control surface attached with an elastic spring including free‐play, and (2) a delta wing with elastic geometrical nonlinearities due to bending and torsional deformations. Both self‐excited oscillations such as flutter and LCO, as well as forced oscillations due to an aerodynamic gust, are discussed. The advantages of representing the unsteady aerodynamic flow field in terms of global modes for such studies are emphasized and illustrated.
MAGNETIC DYNAMO ACTION IN RANDOM FLOWS WITH ZERO AND FINITE CORRELATION TIMES

Hydromagnetic dynamo theory provides the prevailing theoretical description for the origin of magnetic fields in the universe. Here, we consider the problem of kinematic, small-scale dynamo action driven by a random, incompressible, non-helical, homogeneous, and isotropic flow. In the Kazantsev dynamo model, the statistics of the driving flow are assumed to be instantaneously correlated in time. Here, we compare the results of the model with the dynamo properties of a simulated flow that has similar spatial characteristics as the Kazantsev flow but different temporal statistics. In particular, the simulated flow is a solution of the forced Navier-Stokes equations and hence has a finite correlation time. We find that the Kazantsev model typically predicts a larger magnetic growth rate and a magnetic spectrum that peaks at smaller scales. However, we show that by filtering the diffusivity spectrum at small scales it is possible to bring the growth rates into agreement and simultaneously align the magnetic spectra.