cssi/SciSciGPT-SciSciNet huggingface dataset:
The luminosity and stellar mass Fundamental Plane of early‐type galaxies

From a sample of ∼50 000 early-type galaxies from the Sloan Digital Sky Survey, we measured the traditional Fundamental Plane in the g, r, i and z bands. We then replaced luminosity with stellar mass, and measured the 'stellar mass' Fundamental Plane. The Fundamental Plane, R α σ a /I B , steepens slightly as one moves from shorter to longer wavelengths: the orthogonal fit has slope α = 1.40 in the g band and 1.47 in z, with a statistical random error of ∼0.02. However, systematic effects can produce larger uncertainties, of the order of ∼0.05. The Fundamental Plane is thinner at longer wavelengths: it has an intrinsic scatter of 0.062 dex in g and 0.054 dex in z. We have clear evidence that the scatter is larger at small galaxy sizes/masses; at large masses, measurement errors account for essentially all of the observed scatter (about 0.04 dex), suggesting that the Plane is rather thin for the very massive galaxies. The Fundamental Plane steepens further when luminosity is replaced with stellar mass to 1.54 or 1.63 when stellar masses are estimated from broad-band colours or from spectra, respectively. The intrinsic scatter also reduces further to 0.048 dex on average. Since colour and stellar-mass-to-light ratio are closely related, this explains why colour can be thought of as the fourth Fundamental Plane parameter. However, the slope of the stellar mass Fundamental Plane remains shallower than the value of 2 associated with the virial theorem. This is because the ratio of dynamical to stellar mass increases at large masses: M dyn /M * α M 0.17±0.01 dyn . This scaling is the edge-on projection of the stellar mass κ-space. The face-on view suggests that there is an upper limit to the stellar density for a given dynamical mass, and this decreases at large masses: M * /R 3 e α M ―4/3 dyn . All these trends can be used to constrain early-type galaxy formation models. We also study how the estimated coefficients a and B of the Plane are affected by other selection effects, whether in apparent or in absolute quantities. For example, if low-luminosity objects are missing from the sample, and one does not account for this, then a and B are both biased low from their true values. If objects with small velocity dispersions are missing, then a is biased high, although this matters more for the orthogonal than the direct-fitted quantities. These biases are seen in Fundamental Planes which have no intrinsic curvature, so the observation that a and B scale with L and σ is not, by itself, evidence that the Plane is warped. On the other hand, we show that the Plane appears to curve sharply downwards at the small-size/mass end, and more gradually downwards as one moves towards larger sizes/masses. Whereas the drop at small sizes is real, most of the latter effect is due to correlated errors.
A biased review of tau neutrino mass limits

Abstract After a quick review of astrophysically relevant limits, I present a summary of MeV scale tau neutrino mass limits derived from accelerator based experiments. I argue that the current published limits appear to be too consistent, and that we therefore cannot conclude that the tau neutrino mass limit is as low as usually claimed. I provide motivational arguments calling into question the assumed statistical properties of the usual maximum likelihood estimators, and provide a prescription for deriving a more robust and understandable mass limit.
Dominating sets in plane triangulations

In 1996, Matheson and Tarjan conjectured that any n-vertex plane triangulation with n sufficiently large has a dominating set of size at most n/4. We prove this for graphs of maximum degree 6.
The biosynthesis of sinefungin-investigations using a cell-free system

Abstract The origin of the adenylyl moiety of sinefungin has been investigated by administration of doubly-labeled forms of ATP and adenosine to cell-free extracts of Streptomyces griseolus . The results demonstrated that both ATP and adenosine are significantly degraded by the extract before incorporation into sinefungin. However, the ribose ring of adenosine was shown to be incorporated into sinefungin intact, and without loss of tritium from C-5′. This observation rules out the intermediacy of A9145C in sinefungin biosynthesis. Additional experiments are described which suggest that CC bond formation between C-5 of arginine and C-5 of a ribose derivative may precede attachment of the adenine ring.
ChangiNOW: A mobile application for efficient taxi allocation at airports

We present an application that uses a predictive queueing model to efficiently allocate taxis. The system uses observed taxi and flight data at each of the four terminals of Singapore's Changi Airport to estimate the expected waiting time and queue length for taxis arriving at these terminals, and then sends taxis to terminals where demand is highest. We propose a service model that enables our system to be deployed on a smartphone platform to participating taxi drivers. We present the theoretical details which underpin our prediction engine and corroborate our theory with several targeted numerical simulations. Finally, we evaluate the performance of this system in large-scale experiments and show that our system achieves a significant improvement in both passenger and taxi waiting time.
Minimal holographic superconductors from maximal supergravity

We study a truncation of four-dimensional maximal gauged supergravity that provides a realization of the minimal model of a holographic superconductor. We find various flow solutions in this truncation at zero and finite temperature with a non-trivial profile for the charged scalar. Below a critical temperature we find holographic superconductor solutions that represent the thermodynamically preferred phase. Depending on the choice of boundary conditions, the superconducting phase transition is either first or second order. For vanishing temperature we find a flow with a condensing charged scalar that interpolates between two perturbatively stable AdS4 vacua and is the zero-temperature ground state of the holographic superconductor.
WALKS ON GROUPS, COUNTING REDUCIBLE MATRICES, POLYNOMIALS, AND SURFACE AND FREE GROUP AUTOMORPHISMS

We prove sharp limit theorems on random walks on graphs with values in finite groups. We then apply these re- sults (together with some elementary algebraic geometry, number theory, and representation theory) to finite quotients of lattices in semisimple Lie groups (specifically SL(n,Z) and Sp(2n,Z)) to show that a "random" element in one of these lattices has irre- ducible characteristic polynomials (overZ). The term "random" can be defined in at least two ways (in terms of height and also in terms of word length in terms of a generating set) - we show the result using both definitions. We use the above results to show that a random (in terms of word length) element of the mapping class group of a surface is pseudo-Anosov, and that a a random free group automorphism is irreducible with irreducible powers (or strongly irreducible 1 ).
Design and operation of spin valve sensors

Two types of patterned, unshielded Giant MagnetoResistance (GMR) spin valve sensors have been fabricated: nano-layered NiFe/Co/Cu/Co/NiFe and simpler NiFe/Cu/Co spin valves. GMR values of 7.6% for /spl Delta/H=10 Oe were measured for the nano-layered structures on coupons. Transfer curves in uniform fields were obtained and were in agreement with theoretical expectations. The sensors were highly linear and well biased. Optimum biasing of the free layer in the spin valve sensor has new features over that in AMR sensors. These were explored in shielded as well as unshielded spin valves using micromagnetic simulation. >
Locally Estimating Core Numbers

Graphs are a powerful way to model interactions and relationships in data from a wide variety of application domains. In this setting, entities represented by vertices at the 'center' of the graph are often more important than those associated with vertices on the 'fringes'. For example, central nodes tend to be more critical in the spread of information or disease and play an important role in clustering/community formation. Identifying such 'core' vertices has recently received additional attention in the context of network experiments, which analyze the response when a random subset of vertices are exposed to a treatment (e.g. Inoculation, free product samples, etc). Specifically, the likelihood of having many central vertices in any exposure subset can have a significant impact on the experiment. We focus on using k-cores and core numbers to measure the extent to which a vertex is central in a graph. Existing algorithms for computing the core number of a vertex require the entire graph as input, an unrealistic scenario in many real world applications. Moreover, in the context of network experiments, the sub graph induced by the treated vertices is only known in a probabilistic sense. We introduce a new method for estimating the core number based only on the properties of the graph within a region of radius a#x03B4; around the vertex, and prove an asymptotic error bound of our estimator on random graphs. Further, we empirically validate the accuracy of our estimator for small values of a#x03B4; on a representative corpus of real data sets. Finally, we evaluate the impact of improved local estimation on an open problem in network experimentation posed by Ugander et al.
Dark Matter and the Solar Neutrino Problem: Can Particle Physics Provide a Single Solution?

We show how a relatively simple extension of the standard model can give a natural'' explanation for both the solar neutrino and dark matter problems. What is required is a new stable neutral lepton with a mass in the 4--8 GeV range. One possibility is a fourth generation neutrino interacting with matter either electromagnetically or via higgs-exchange (in addition, of course, to Z{degree}-exchange). In the former case, a new charged lepton with mass {approximately}10GeV would be required in order to generate a sufficiently large magnetic moment. The present experimental situation makes this possibility rather doubtful. In the latter case, a light higgs with mass {approximately}1GeV is required; this is still not ruled out experimentally. In any case, direct (or indirect) detection of dark matter will, during the next year, seal the fate of this model. 29 refs.
Computational Study of Vibrationally Relaxing Gas past Blunt Body in Hypersonic Flows

Numerical simulations are presented of a steady-state, hypersonic e ow over a two-dimensional cylinder of 1 m radius under conditions where the relaxation of the vibrational modes is signie cant. A Mach 6.5 nitrogen e ow was simulated atfreestream pressuresof50, 250, and500 Pa, witha freestream translational temperatureof300K.Two differentfreestream vibrationaltemperatures,300K (causing vibrationalheating )and4000K(causing vibrational cooling)were considered to study the effects on the e owe eld. An upwind-difference numerical scheme was used to solve the inviscid Euler equations coupled to the vibrational kinetic models of diatomic nitrogen, assumed as an anharmonic oscillator of 40 quantum levels using two sets of reaction rates. Comparison with previously reported computations showed a maximum variation of 10% in translational and e rst-level vibrational temperature along thesurfaceduetodifferencesinnumericalschemesandgriddensities;variationcausedbythetwodifferentreaction rate sets was less than 2%. The vibrational cooling case showed a 10% higher shock-standoff distance than the vibrational heating case. The population distribution for the cooling case was non-Boltzmann due to nonresonant energy exchangesin the postshock region, greaterin theshoulder region than in thestagnation region. An increase in freestream pressure for the cooling case increased the shock-standoff distance and non-Boltzmann behavior in the postshock region and near the surface. There was, however, a larger equilibrium region in between, in the stagnation region.
Intermolecular nonreductive alkylation of enamides via radical-polar crossover.

A carbon−carbon bond construction method is disclosed which involves radical addition of α-haloesters or iodoacetonitrile to enamides. Despite the presence of tri-n-butylstannane, nonreductive addition was predominant; H-atom transfer from tin hydride was not observed. Rapid iodine atom transfer to (or electron transfer from) the radical adduct, resulting in an iminium ion intermediate and radical chain propagation, is consistent with the observed reactivity.
Gravitational waves from extragalactic inspiraling binaries: Selection effects and expected detection rates

We examine the selection effects that determine how the population of inspiraling binary compact objects (BCOs) is reflected by those potentially observed with ground-based interferometers like LIGO. We lay the groundwork for the interpretation of future observations in terms of constraints on the real population and, correspondingly, binary star evolution models.To determine the extragalactic population of inspiraling binaries, we combine data on distance and blue luminosity from galaxy catalogs with current models of the Galactic BCO mass distribution to simulate the physical distribution of binaries in the nearby universe. We use Monte Carlo methods to determine the fraction of binaries observable by the LIGO detectors from each galaxy as a function of the BCO chirp mass. We examine separately the role of source distance, sky position, time of detection, and binary system chirp mass on the detection efficiency and selection effects relevant to the three LIGO detectors. Finally, we discuss the implications of the nearby geography of space on anticipated gravitational wave detection and compare our results to those of previous studies, which have assumed uniform galaxy volume density and fixed chirp mass for BCOs. From these considerations, actual BCO inspiral observations or significant upper limits on the coalescence rate anticipated in the near future by ground-based interferometers can be used to improve our knowledge of the Galactic binary inspiral rate and to constrain models of radio pulsar characteristics and binary star evolution channels leading to neutron star or black hole binaries.
Fine-Scale Simulation of Sandstone Acidizing

We have developed a fine-scale model of the sandstone core acid flooding process by solving acid and mineral balance equations for a fully three-dimensional flow field that changed as acidizing proceeded. The initial porosity and mineralogy field could be generated in a correlated manner in three dimensions; thus, a laminated sandstone could he simulated. The model has been used to simulate sandstone acidizing coreflood conditions, with a I in. diam by 2 in. long core represented by 8000 grid blocks, each having different initial properties. Results from this model show that the presence of small-scale heterogeneities in a sandstone has a dramatic impact on the acidizing process. Flow field heterogeneities cause acid to penetrate much farther into the formation than would occur if the rock were homogeneous, as is assumed by standard models. When the porosity was randomly distributed (sampled from a nominal distribution), the acid penetrated up to twice as fast as in the homogeneous case. When the porosity field is highly correlated in the axial direction, which represents a laminated structure, acid penetrates very rapidly into the matrix along the high-permeability streaks, reaching the end of the simulated core as much as 17 times faster than for a homogeneous case.
PWM Impact on CM Noise and AC CM Choke for Variable-Speed Motor Drives

This paper analyzes pulsewidth modulation (PWM) methods' impact on the motor drives' common-mode (CM) noise current and CM choke saturation. The modulation in the motor drive terminals serves as the CM noise source. A few improved PWM methods could reduce the CM voltage amplitude in comparison with the conventional space vector PWM and discontinuous PWM. However, some harmonics of the improved PWM methods increase when considering the spectrum. Because the CM loop of the motor drive system is an L-R-C circuit which has its resonant frequency, the CM noise current is highly influenced by the noise near the resonant frequency. This paper studies the CM current with different PWM methods and claims that the design of PWM methods and switching frequency should be together with the CM loop impedance. Reduced CM voltage does not mean reduced CM current. With a CM choke to attenuate the CM noise, the choke size is determined by the CM volt-seconds on the choke. This paper studies the general case and the worst case of the choke size. The conclusions are supported by simulation and experimental results.
One-instanton test of a Seiberg-Witten curve from M-theory: the antisymmetric representation of SU(N)

Abstract One-instanton predictions are obtained from the Seiberg-Witten curve derived from M-theory by Landsteiner and Lopez for the Coulomb branch of N = 2 supersymmetric SU(N) gauge theory with a matter hypermultiplet in the antisymmetric representation. Since this cubic curve describes a Riemann surface that is non-hyperelliptic, a systematic perturbation expansion about a hyperelliptic curve is developed, with a comparable expansion for the Seiberg-Witten differential. Calculation of the period integrals of the SW differential by the method of residues of D'Hoker, Krichever, and Phong enables us to compute the prepotential explicitly to one-instanton order. It is shown that the one-instanton predictions for SU(2), SU(3), and SU(4) agree with previously available results. For SU(N), N ⩾ 5, our analysis provides explicit predictions of a curve derived from M-theory at the one-instanton level in field theory.
Determinants of Mortality in Patients With Severe Blunt Head Injury

Context Head injury is the leading cause of traumatic death in the United States. Hypothesis A set of clinical parameters available soon after injury can be used to accurately predict outcome in patients with severe blunt head trauma. Design Validation cohort study. Setting Urban level I trauma center. Patients and Methods Data from patients with severe blunt head injury, as defined by inability to follow commands, were prospectively entered into a neurosurgical database and analyzed. The impact on survival of 23 potentially predictive parameters was studied using univariate analysis. Logistic regression models were used to control for confounding factors and to assess interactions between variables, whose significance was determined by univariate analysis. Goodness of fit was calculated with the Hosmer-Lemeshow c statistic. The predictability of the logistic model was evaluated by measuring the area under the receiver operating characteristic curve (AUC). Results Logistic regression analysis revealed that 5 risk factors were independently associated with death. These variables included systemic hypotension in the emergency department, midline shift on computed tomographic scan, intracranial hypertension, and absence of pupillary light reflex. A low Glasgow Coma Scale score and advanced age were found to be highly correlated risk factors that, when combined, were independently associated with mortality. The model showed acceptable goodness of fit, and the AUC was 80.5%. Conclusions Systemic hypotension and intracranial hypertension are the only independent risk factors for mortality that can be readily treated during the initial management of patients with severe head injuries. When used together, Glasgow Coma Scale score and age are significant predictors of mortality.
Efficient topology-controlled sampling of implicit shapes

Sampling from distributions of implicitly defined shapes enables analysis of various energy functionals used for image segmentation. Recent work [1] describes a computationally efficient Metropolis- Hastings method for accomplishing this task. Here, we extend that framework so that samples are accepted at every iteration of the sampler, achieving an order of magnitude speed up in convergence. Additionally, we show how to incorporate topological constraints.
Prevalence of the Metabolic Syndrome Among US Adults: Findings From the Third National Health and Nutrition Examination Survey

ContextThe Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) highlights the importance of treating patients with the metabolic syndrome to prevent cardiovascular disease. Limited information is available about the prevalence of the metabolic syndrome in the United States, however.ObjectiveTo estimate the prevalence of the metabolic syndrome in the United States as defined by the ATP III report.Design, Setting, and ParticipantsAnalysis of data on 8814 men and women aged 20 years or older from the Third National Health and Nutrition Examination Survey (1988-1994), a cross-sectional health survey of a nationally representative sample of the noninstitutionalized civilian US population.Main Outcome MeasuresPrevalence of the metabolic syndrome as defined by ATP III (≥3 of the following abnormalities): waist circumference greater than 102 cm in men and 88 cm in women; serum triglycerides level of at least 150 mg/dL (1.69 mmol/L); high-density lipoprotein cholesterol level of less than 40 mg/dL (1.04 mmol/L) in men and 50 mg/dL (1.29 mmol/L) in women; blood pressure of at least 130/85 mm Hg; or serum glucose level of at least 110 mg/dL (6.1 mmol/L).ResultsThe unadjusted and age-adjusted prevalences of the metabolic syndrome were 21.8% and 23.7%, respectively. The prevalence increased from 6.7% among participants aged 20 through 29 years to 43.5% and 42.0% for participants aged 60 through 69 years and aged at least 70 years, respectively. Mexican Americans had the highest age-adjusted prevalence of the metabolic syndrome (31.9%). The age-adjusted prevalence was similar for men (24.0%) and women (23.4%). However, among African Americans, women had about a 57% higher prevalence than men did and among Mexican Americans, women had about a 26% higher prevalence than men did. Using 2000 census data, about 47 million US residents have the metabolic syndrome.ConclusionsThese results from a representative sample of US adults show that the metabolic syndrome is highly prevalent. The large numbers of US residents with the metabolic syndrome may have important implications for the health care sector.
Hydroboration with pyridine borane at room temperature.

Treatment of pyridine borane (Py·BH3) with iodine, bromine, or strong acids affords activated Py·BH2X complexes that are capable of hydroborating alkenes at room temperature. Evidence is presented for an unusual hydroboration mechanism involving leaving group displacement. In contrast to THF·BH3, hydroboration with Py·BH2I selectively affords the monoadducts. The crude hydroboration products are converted into synthetically useful potassium alkyltrifluoroborate salts upon treatment with methanolic KHF2.
On the homology of low-dimensional cohomogeneity one manifolds

In this paper we give a characterization of the possible homology groups that can occur for compact simply connected cohomogeneity one manifolds in dimensions 7 and lower.
EFFECTS OF HYDROSTATIC PRESSURE AND OF JAHN-TELLER DISTORTIONS ON THE MAGNETIC PROPERTIES OF RbFeF3

The first-order transitions at ${T}_{1}=40$\ifmmode^\circ\else\textdegree\fi{}K and ${T}_{2}=87$\ifmmode^\circ\else\textdegree\fi{}K in RbFe${\mathrm{F}}_{3}$ have been measured as a function of hydrostatic pressure and applied magnetic field. It was not possible to observe the ${T}_{N}=102$\ifmmode^\circ\else\textdegree\fi{}K transition with a magnetic-susceptibility measurement. It was found that ${(\frac{\ensuremath{\Delta}{T}_{1}}{\ensuremath{\Delta}{H}_{a}})}_{p}=\frac{{0.35}^{\ensuremath{\circ}}}{\mathrm{kOe}}$, ${(\frac{\ensuremath{\Delta}{T}_{2}}{\ensuremath{\Delta}{H}_{a}})}_{p}=\frac{{0.19}^{\ensuremath{\circ}}}{\mathrm{kOe}}$, ${(\frac{\ensuremath{\Delta}{T}_{1}}{\ensuremath{\Delta}P})}_{H}=\frac{{0.18}^{\ensuremath{\circ}}}{\mathrm{kbar}}$ and ${(\frac{\ensuremath{\Delta}{T}_{2}}{\ensuremath{\Delta}P})}_{H}=\frac{\ensuremath{-}{0.81}^{\ensuremath{\circ}}}{\mathrm{kbar}}$. These results correspond to latent heats of 0.006 and 0.04 cal/g at ${T}_{1}$ and ${T}_{2}$, respectively, and relative volume changes $\frac{\ensuremath{\Delta}{V}_{1}}{{V}_{1}}=1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $\frac{\ensuremath{\Delta}{V}_{2}}{{V}_{2}}=\ensuremath{-}22\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. It is pointed out that a Jahn-Teller distortion to tetragonal ($\frac{c}{a}g1$) symmetry in the interval ${T}_{2}lTl{T}_{N}$ introduces a strong magnetoelastic coupling. This causes the heavy twinning that has been observed below ${T}_{N}$, and the resulting twinned structure is retained in the entire temperature interval $0lTl{T}_{N}$. In the temperature interval ${T}_{1}lTl{T}_{2}$, ${\mathrm{Rb}}^{+}$-${\mathrm{F}}^{\ensuremath{-}}$ interactions induce distortions to orthorhombic or tetragonal symmetries that are superimposed on the Jahn-Teller distortion. The orthorhombic distortion is cooperative across twin boundaries caused by the Jahn-Teller distortion and also permits spin canting, which introduces a ferromagnetic component below ${T}_{2}$. It is shown how the interplay of these distortions plus strong magnetoelastic coupling can explain the appearance of two sets of M\"ossbauer peaks below ${T}_{2}$ and results in macroscopic ferromagnetic components having cubic symmetry even though the microscopic crystallographic symmetry is "orthorhombic" (${T}_{1}lTl{T}_{2}$). The Jahn-Teller distortion changes to rhombohedral ($\ensuremath{\alpha}l{60}^{\ensuremath{\circ}}$) for $Tl{T}_{1}$; in combination with the existing orthorhombic structure, this produces monoclinic symmetry on a microscopic scale. Nevertheless, it is shown that the macroscopic magnetization retains its cubic symmetry, that the easy magnetization direction changes from $〈100〉$ to the $〈110〉$, that the apparent moment increases, and that there may still be two sets of M\"ossbauer peaks.
Quantal response equilibria with heterogeneous agents

Abstract This paper introduces a model of quantal response equilibrium with heterogeneous agents and demonstrates the existence of a representative agent for such populations. Except in rare cases, the representative agentʼs noise terms cannot be independently and identically distributed across the set of actions, even if that is assumed for the individual agents. This result demonstrates a fundamental difference between a representative agent and truly heterogeneous quantal responders and suggests that when fitting quantal response specifications to aggregate data from a population of subjects, the noise terms should be allowed to be jointly dependent across actions. Even though this introduces additional degrees of freedom, it makes the model well specified. The representative agent inherits a regular quantal response function from the actual agents, so this model does impose falsifiable restrictions.
New Reactor Neutrino Experiments besides Double-CHOOZ

Several new reactor neutrino experiments are being considered to measure the parameter θ 13 . The current plans for Angra, Braidwood, Daya Bay, KASKA and KR2DET are reviewed. A case is made that, together with Double-CHOOZ, a future world program should include at least three such experiments.
Bacteriophage PBS2-Induced Deoxycytidine Triphosphate Deaminase in Bacillus subtilis

The dCTP deaminase induced by Bacillus subtilis bacteriophage PBS2, whose DNA contains uracil instead of thymine, requires metal ion and thiol activators and has a molecular weight of 125,000. The enzyme displays sigmoidal substrate saturation kinetics and inhibition by dUTP, consistent with the deaminase's proposed role of providing balanced levels of dUTP and dCTP for PBS2 uracil-DNA synthesis.
A methodology for multi-criteria information system design

The design dilemma faced by the designer is to satisfy a set of conflicting user demands and resolve a set of conflicting resource requirements concurrently. In light of the complexity of modern systems, it is assumed that good system design need only produce satisfactory performance for both criteria. Current evaluative techniques, however, concentrate on either the user criterion or the system criterion aspect of the total design problem, but not both. A methodology has been developed that establishes a formal liaison between the evaluation of user goals as a function of system activity and the evaluation of resource utilization as a function of user demand, thereby creating a design/evaluation process that encompasses both criteria. The methodology employs three stages in an iterative manner to produce a "satisfactory" design. The IPSS simulator models and measures system activity, multiple goal programming evaluates both user and system goals, and heuristic procedures determine design modifications to improve performance. A functional description of the methodology and an example of its use will be presented.
Performance of low-density parity-check coded modulation

This paper reports the performance of a family of nine accumulate-repeat-4-jagged-accumulate (AR4JA) low-density parity-check (LDPC) codes [4] when used in conjunction with binary phase-shift-keying (BPSK), quadrature PSK (QPSK), 8-PSK, 16-ary amplitude PSK (16-APSK), and 32-APSK. We also report the performance under various mappings of bits to modulation symbols, hard decision decoding, log-likelihood ratio (LLR) approximations, and decoder iterations. One of the simple and well-performing LLR approximations can be expressed in a general equation that applies to all of the modulation types.
Chaotic scattering in solitary wave interactions: a singular iterated-map description.

We derive a family of singular iterated maps—closely related to Poincare maps—that describe chaotic interactions between colliding solitary waves. The chaotic behavior of such solitary-wave collisions depends on the transfer of energy to a secondary mode of oscillation, often an internal mode of the pulse. This map allows us to go beyond previous analyses and to understand the interactions in the case when this mode is excited prior to the first collision. The map is derived using Melnikov integrals and matched asymptotic expansions and generalizes a “multipulse” Melnikov integral. It allows one to find not only multipulse heteroclinic orbits, but exotic periodic orbits. The maps exhibit singular behavior, including regions of infinite winding. These maps are shown to be singular versions of the conservative Ikeda map from laser physics and connections are made with problems from celestial mechanics and fluid mechanics.
Measuring Stellar Velocity Dispersions in Active Galaxies

We present stellar velocity dispersion (σ*) measurements for a significant sample of 40 broad-line (type 1) active galaxies for use in testing the well-known relation black hole mass and stellar velocity dispersion. The objects are selected to contain Ca II triplet, Mg I b triplet, and Ca H+K stellar absorption features in their optical spectra so that we may use them to perform extensive tests of the systematic biases introduced by both template mismatch and contamination from the active galactic nucleus (AGN). We use the Ca II triplet as a benchmark to evaluate the utility of the other spectral regions in the presence of AGN contamination. Broad Fe II emission, extending from ~5050 to 5520 A, in combination with narrow coronal emission lines, can seriously bias σ* measurements from the Mg I b region, highlighting the need for extreme caution in its use. However, we argue that at luminosities constituting a moderate fraction of the Eddington limit, when the Fe II lines are both weak and smooth relative to the stellar lines, it is possible to derive meaningful measurements with careful selection of the fitting region. In particular, to avoid the contamination of coronal lines, we advocate the use of the region 5250-5820 A, which is rich in Fe absorption features. At higher AGN contaminations, the Ca H+K region may provide the only recourse for estimating σ*. These features are notoriously unreliable, due to a strong dependence on spectral type, a steep local continuum, and large intrinsic broadening. Indeed, we find a strong systematic trend in comparisons of Ca H+K with other spectral regions. Luckily the offset is well described by a simple linear fit as a function of σ*, which enables us to remove the bias and thus extract unbiased σ* measurements from this region. We lay the groundwork for an extensive comparison between black hole mass and bulge velocity dispersion in active galaxies, as described in a companion paper by Greene & Ho.
Insiders, Outsiders, and Market Breakdowns

A simple classical Walrasian framework is proposed for the study of manipulation among asymmetrically informed risk-averse traders in financial markets, and it is used to analyze the occurrence of a market breakdown in the trading system. Such a phenomenon occurs when the outsiders refuse to trade with the insiders because the informational motive for trade of the insider outweighs her hedging motive. We demonstrate the robustness of our results by proving that the market collapse condition extends not only to the linear strategy function, but to the whole class of feasible nonlinear strategy function, but to the whole class of feasible nonlinear strategy functions. Implications for insider-trading regulation are sketched. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Regioselective cyclopropanation reactions using iodonium ylides: Synthesis of prostaglandin precursors

Abstract Iodonium ylides of methyl 3-oxo- trans,trans -6,8-tetradecadienoate ( 1 ) and diprotected methyl 3,5-di(t-butyldimethyl-silyloxy)-2,6,8-tetrahecatrieneoate ( 5 ) undergo regio- and stereoselective intramolecular cyclopropanation with Cu(I)Cl catalysis to form key bicyclo[3.1.0] intermediates for prostaglandin synthesis.
Detecting the transition from Pop III to Pop II stars

Abstract We discuss the cosmological significance of the transition from the Pop III to Pop II mode of star formation in the early universe, and when and how it may occur in primordial galaxies. Observations that could detect this transition include those of element abundances in metal-poor Galactic halo stars, and of the helium reionization and associated heating of the intergalactic medium. We suggest that γ-ray bursts may be a better probe of the end of the first-stars epoch than of Pop III stars.
1,6-ADDITION OF ORGANOCOPPER REAGENTS TO 3-ALKYNYL-2-CYCLOALKENONES : REGIOSPECIFIC SYNTHESES OF DIENONES AND ALLENES

To investigate the preparation of allenes by means of 1,6-addition reactions to 2-alken-4-ynones, 3-ethynyl-2-cycloalkenones were synthesized and reacted with a variety of organocopper nucleophiles. Such nucleophiles undergo regiospecific 1,6-additions to generates intermediate allenyl enolates, which are regiospecifically and stereoselectively protonated to yield a preponderance of (Z)-3-alkenyl-2-cycloalkenones. The reaction is sensitive to the nature of the organocopper reagent used; higher order cyanocuprates derived from organolithium reagents are the reagents of choice
Patterns of remittances and labor migration in the Arab world.

This is a review of the history of labor migration as it has affected the Arab world from the oil boom of the early 1970s to the present with particular attention to the changing flow of remittances from migrants to their country of origin. (SUMMARY IN FRE AND SPA) (ANNOTATION)
Why are some mutual funds closed to new investors

Abstract Fund families typically claim that closing a fund protects the fund's superior performance by preventing it from growing too large to be managed efficiently. Even though funds with better performance and larger size are more likely to be closed, there is no evidence that closing a fund can indeed protect its performance. Instead, fund closing decisions are more likely to be motivated by spillover effects – by closing a star fund, the fund family signals its superior performance and also brings investors' attention and investments to other funds in the family. Some evidence exists to suggest that the closing strategy is effective in generating higher inflows into the rest of the family, at least in the short run.
The chaos router: a practical application of randomization in network routing

We present the chaos router, an asynchronous adaptive router, which under certain circumstances can send messages farther from their destinations. The chaos router greatly simplifies the routing logic by removing the livelock protection of previous schemes. Through an effective use of randomness, whose sources include that due to the adaptively processed load, the natural timing differences of selftimed circuitry and explicitly injected randomization, the chaos router avoids long message routes with high probability. In this paper the router is described, it is argued that the chaos router is deadlock free and probabilistically live-lock and starvation free, and simulation results are presented showing that the chaos router performs well.
Hard Limiting in Synthetic Aperture Signal Processing

In synthetic aperture radar a large linear phased array is formed from the rapid movement of a single element through each position in the array. Storage and coherent combining of the successive radar echoes are central to the array-forming process. Optical processing is the most common technique because of the efficiency with which Fourier transformation may be accomplished with simple optics. Real-time operation, however, requires all-electronic processing, which is difficult to accomplish because of the huge quantity of data to be manipulated. Dynamic range compression by hard limiting may ease the problem by reducing the number of bits per frame. The effects of hard limiting are analyzed in this paper. It is shown that large targets simultaneously illuminated by the radar antenna will produce image targets or ghosts displaced in angle. Statistically homogeneous clutter will "linearize" the hard-limited receiver and suppress the ghosts without loss in contrast, as does thermal noise if it is larger than the target echoes. Pulse compression reduces the probability of images from prominent targets. Judicious choice of the pulse-compression waveform is a powerful tool for destroying coherent buildup of images from all large targets not in the same range resolution cell. Linear FM, the most common choice, unfortunately does not exhibit this desirable property.
Fermions in loop quantum cosmology and the role of parity

Fermions play a special role in homogeneous models of quantum cosmology because the exclusion principle prevents them from forming sizable matter contributions. They can thus describe the matter ingredients only truly microscopically and it is not possible to avoid strong quantum regimes by positing a large matter content. Moreover, possible parity-violating effects are important especially in loop quantum cosmology whose basic object is a difference equation for the wavefunction of the universe defined on a discrete space of triads. The two orientations of a triad are interchanged by a parity transformation, which leaves the difference equation invariant for ordinary matter. Here, we revisit and extend loop quantum cosmology by introducing fermions and the gravitational torsion they imply, which renders the parity issue non-trivial. A treatable locally rotationally symmetric Bianchi model is introduced which clearly shows the role of parity. General wavefunctions cannot be parity-even or odd, and parity-violating effects in matter influence the microscopic big bang transition which replaces the classical singularity in loop quantum cosmology.
Occupational Therapists and Physical Therapists: Vital Members in the Rehabilitation and Educational Process of Disabled Students

The services of physical and occupational therapists are being used more in public school settings as a result of the mandate of United States Public Law 94–142. These professionals help educators in developing the students' gross and fine motor skills, vocational skills, and self-help skills. In addition, physical therapists and occupational therapists serve with educators on transdisciplinary teams in developing goals and objectives to more appropriately meet the educational needs of disabled students.
How much anonymity does network latency leak

Low-latency anonymity systems such as Tor, AN.ON, Crowds, and Anonymizer.com aim to provide anonymous connections that are both untraceable by “local” adversaries who control only a few machines and have low enough delay to support anonymous use of network services like Web browsing and remote login. One consequence of these goals is that these services leak some information about the network latency between the sender and one or more nodes in the system. We present two attacks on low-latency anonymity schemes using this information. The first attack allows a pair of colluding Web sites to predict, based on local timing information and with no additional resources, whether two connections from the same Tor exit node are using the same circuit with high confidence. The second attack requires more resources but allows a malicious Web site to gain several bits of information about a client each time he visits the site. We evaluate both attacks against two low-latency anonymity protocols—the Tor network and the MultiProxy proxy aggregator service—and conclude that both are highly vulnerable to these attacks.
Inference of Population Splits and Mixtures from Genome-Wide Allele Frequency Data

Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In our model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data, we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively) to wolves subsequent to domestication and that East Asian toy breeds (the Shih Tzu and the Pekingese) result from admixture between modern toy breeds and “ancient” Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.com.
QCD in extreme environments

Abstract I review present challenges that QCD in extreme environments presents to lattice gauge theory. Recent data and impressions from RHIC are emphasized. Physical pictures of heavy ion wavefunctions, collisions and the generation of the Quark Gluon Plasma are discussed, with an eye toward engaging the lattice and its numerical methods in more interaction with the experimental and phenomenological developments. Controversial, but stimulating scenarios which can be confirmed or dismissed by lattice methods are covered. In the second half of the talk, several promising developments presented at the conference Lattice 2002 are reviewed.
Holography and Education

Holography can be taught to anyone in context as art, craft, or science using safe and low cost equipment. Leith gave me a hologram in 1965 that started my career in holography to this day.
Quantum Supergroups I. Foundations

In this part one of a series of papers, we introduce a new version of quantum covering and super groups with no isotropic odd simple root, which is suitable for the study of integrable modules, integral forms, and the bar involution. A quantum covering group involves parameters q and π with π2 = 1, and it specializes at π = −1 to a quantum supergroup. Following Lusztig, we formulate and establish various structural results of the quantum covering groups, including a bilinear form, quasi-\( \mathcal{R} \)-matrix, Casimir element, character formulas for integrable modules, and higher Serre relations.
D-BigBand: sensing GHZ-wide non-sparse spectrum on commodity radios

This paper presents D-BigBand, a system that senses a GHz-wide spectrum in real time using ADCs sampling at only tens of MS/s speed. It is an advanced version of our previous work, BigBand, which senses GHz-wide sparse spectrum using commodity radios. However, unlike BigBand that requires the spectrum to be sparse, D-BigBand does not assume sparsity utilization of the spectrum. This is particularly important for the spectrum under 2GHz which is typically not sparse, crowded with different wireless technologies like TV broadcasting, mobile, AM radios, etc. The key idea of D-BigBand is to run sparse recovery on the changes of the spectrum: since only a small fraction of the spectrum is likely to change its occupancy over short intervals of a few milliseconds, the changes of the spectrum is sparse and we can apply sparse recovery to it. Our evaluation shows that D-BigBand works even if 95% of the spectrum is occupied.
Referendum contingent valuation, anchoring, and willingness to pay for public goods

This study reports on experiments that examine anchoring in single referendum questions in contingent valuation surveys on willingness to pay for public goods, and on objective estimation. Strong anchoring effects are found that lead to systematically higher estimated mean responses from Yes/No referendum responses than from open-ended responses. This response pattern is similar for contingent valuation questions and for objective estimation questions. The paper concludes that psychometric anchoring effects, rather than incentive effects, are the likely cause of results commonly found in contingent valuation studies, and that the currently popular single referendum elicitation format is highly vulnerable to anchoring.
CPG-based control of a turtle-like underwater vehicle

This paper presents biologically inspired control strategies for an autonomous underwater vehicle (AUV) propelled by flapping fins that resemble the paddle-like forelimbs of a sea turtle. Our proposed framework exploits limit cycle oscillators and diffusive couplings, thereby constructing coupled nonlinear oscillators, similar to the central pattern generators (CPGs) in animal spinal cords. This paper first presents rigorous stability analyses and experimental results of CPG-based control methods with and without actuator feedback to the CPG. In these methods, the CPG module generates synchronized oscillation patterns, which are sent to position-servoed flapping fin actuators as a reference input. In order to overcome the limitation of the open-loop CPG that the synchronization is occurring only between the reference signals, this paper introduces a new single-layered CPG method, where the CPG and the physical layers are combined as a single layer, to ensure the synchronization of the physical actuators in the presence of external disturbances. The key idea is to replace nonlinear oscillators in the conventional CPG models with physical actuators that oscillate due to nonlinear state feedback of the actuator states. Using contraction theory, a relatively new nonlinear stability tool, we show that coupled nonlinear oscillators globally synchronize to a specific pattern that can be stereotyped by an outer-loop controller. Results of experimentation with a turtle-like AUV show the feasibility of the proposed control laws.