cssi/SciSciGPT-SciSciNet huggingface dataset:
Stellar Mass Black Holes in Young Galaxies

We explore the potential cumulative energy production of stellar-mass black holes in early galaxies. Stellar-mass black holes may accrete substantially from the higher density interstellar media (ISMs) of primordial galaxies, and their energy release would be distributed more uniformly over the galaxies, perhaps providing a different mode of energy feedback into young galaxies than central supermassive black holes. We construct a model for the production and growth of stellar-mass black holes over the first few gigayears of a young galaxy. With the simplifying assumption of a constant density of the ISM, n {approx} 10{sup 4}-10{sup 5} cm{sup -3}, we estimate the number of accreting stellar-mass black holes to be {approx}10{sup 6} and the potential energy production to be as high as 10{sup 61} erg over several billion years. For densities less than 10{sup 5} cm{sup -3}, stellar-mass black holes are unlikely to reach their Eddington limit luminosities. The framework we present could be incorporated in numerical simulations to compute the feedback from stellar-mass black holes with inhomogeneous, evolving ISMs.
Distributed Synchronization of Heterogeneous Oscillators on Networks With Arbitrary Topology

Many network applications rely on the synchronization of coupled oscillators. For example, such synchronization can provide networked devices with a common temporal reference necessary for coordinating actions or decoding transmitted messages. In this paper, we study the problem of using distributed control to achieve phase and frequency synchronization of a network of coupled heterogeneous nonlinear oscillators. Not only do our controllers guarantee zero-phase error in steady state under arbitrary frequency heterogeneity, but they also require little knowledge of the oscillator nonlinearities and network topology. Furthermore, we provide a global convergence analysis, in the absence of noise and propagation delay, for the resulting nonlinear system whose phase vector evolves on the $\boldsymbol{n}$ -torus.
Branes And The Dynamics Of QCD

Abstract A brane configuration is described that is relevant to understanding the dynamics of N = 1 supersymmetric Yang-Mills theory. Confinement and spontaneous breaking of a discrete chiral symmetry can be understood as consequences of the topology of the brane. Because of the symmetry breaking, there can be domain walls separating different vacua; the QCD string can end on such a domain wall. The model in which these properties can be understood semiclassically does not coincide with supersymmetric Yang-Mills theory but is evidently in the same universality class.
A facile synthesis of novel 3-(aryl/alkyl-2-ylmethyl)-2-thioxothiazolidin-4-ones using microwave heating

(Z)-5-(2-(1H-Indol-3-yl)-2-oxoethylidene)-3-(aryl/alkyl-2-ylmethyl)-2-thioxothiazolidin-4-ones (7a–w) have been synthesized by the Knoevenagel condensation reaction of 3-(aryl/alkyl-2-ylmethyl)-2-thioxothiazolidin-4-ones (3a–d) with suitably substituted 2-(1H-indol-3-yl)2-oxoacetaldehydes (6a–g) under microwave conditions. The thioxothiazolidin-4-ones were prepared from the corresponding aryl/alkyl amines (1a–d) and di-(carboxymethyl)-trithiocarbonyl (2). The aldehydes (6a–g) were synthesized from the corresponding acid chlorides (5a–g) using HsnBu3.
Theory of Laminar Viscous-Inviscid Interactions in Supersonic Flow

This investigation is concerned with those fluid-mechanical problems in which the pressure distribution is determined by the interaction between an external, supersonic inviscid flow and an inner, laminar viscous layer. The boundary-layer approximations are assumed to remain valid throughout the viscous region, and the integral or moment method of Lees and Reeves, extended to include flows with heat transfer; is used in the analysis. The general features of interacting flows are established, including the important distinctions between subcritical and supercritical viscous layers. The eigensolution representing self-induced boundary-layer flow along a semi-infinite flat plate is determined, and a consistent set of departure conditions is derived for determining solutions to interactions caused by external disturbances. Complete viscous-inviscid interactions are discussed in detail, with emphasis on methods of solution for both subcritical and supercritical flows. The method is also shown to be capable of predicting the laminar flow field in the near wake of blunt bodies. Results of the present theory are shown to be in good agreement with the measurements of Lewis for boundary-layer separation in adiabatic and non-adiabatic compression corners, and with the near-wake experiments of Dewey and McCarthy for adiabatic flow over a circular cylinder. Extensions of the method to flows with mass injection at the surface and to subsonic interactions are indicated.
Dielectric nanostructures for broadband light trapping in organic solar cells

We investigate broadband light trapping using only dielectric components to improve organic solar cell efficiency. We show that substantial absorption and photocurrent enhancement is possible using top-surface ITO gratings in these devices.
Sparsity-Exploiting Moment-Based Relaxations of the Optimal Power Flow Problem

Convex relaxations of non-convex optimal power flow (OPF) problems have recently attracted significant interest. While existing relaxations globally solve many OPF problems, there are practical problems for which existing relaxations fail to yield physically meaningful solutions. This paper applies moment relaxations to solve many of these OPF problems. The moment relaxations are developed from the Lasserre hierarchy for solving generalized moment problems. Increasing the relaxation order in this hierarchy results in “tighter” relaxations at the computational cost of larger semidefinite programs. Low-order moment relaxations are capable of globally solving many small OPF problems for which existing relaxations fail. By exploiting sparsity and only applying the higher-order relaxation to specific buses, global solutions to larger problems are computationally tractable through the use of an iterative algorithm informed by a heuristic for choosing where to apply the higher-order constraints. With standard semidefinite programming solvers, the algorithm globally solves many test systems with up to 300 buses for which the existing semidefinite relaxation fails to yield globally optimal solutions.
Rapidly Rotating Relativistic Stars

Within the last decade, significant progress has been made in modelling rotating stars in general relativity and in relating observable properties to the equation of state of matter at high density. A formalism describing rotating perfect fluids is presented and numerical models of neutron stars are briefly discussed, with emphasis on upper limits on mass and rotation. The equations governing small oscillations are reviewed, and a variational principle appropriate both to eulerian and lagrangian perturbations is obtained. This extends to relativity an eulerian principle used to find non-axisymmetric stability points for perfect fluids. A related eulerian approach has been recently used to obtain normal modes of rotating newtonian stars. The review concludes with an outline of this work and of the two types of instability that can restrict the range of neutron stars. In particular, current work shows that several kinds of effective viscosity limit the possible role of a non-axisymmetric instability driven by gravitational waves.
The Elusive closo-Ge102− Zintl Ion: Finally “Captured” as a Ligand in the Complex [Ge10Mn(CO)4]3−

Although often seen in mass spectra, the otherwise elusive closo-Ge102− Zintl ion has been finally structurally characterized as coordinated to manganese in [Ge10Mn(CO)4]3− made by the reaction of nido-Ge94− with Mn2(CO)10 in ethylenediamine. The new cluster is a bicapped square antiprism, as expected for a closo-deltahedron of 10 atoms.
The stereoselective conversion of 2-alkenyl alcohols to (R)- or (S)-alkane-1,2-diols using D-glucose as a chiral auxiliary

Abstract The stereoselective addition of the 2-hydroxyl group of glucose to the mercurated vinyl group of 2-alkenyl glycosides followed by hydride reduction and removal of the saccharide fragment was used to prepare enantiomerically pure 1,2-dihydroxy alkanes. Diols of (R) or (S) configuration can be synthesized from (α)-glycosides or the (β) form respectively. Demercuration with chloride ion led to the insertion of a halo group adjacent to the new chiral center thus allowing for the possibility of further functionalization.
Sparse Representation of a Polytope and Recovery of Sparse Signals and Low-Rank Matrices

This paper considers compressed sensing and affine rank minimization in both noiseless and noisy cases and establishes sharp restricted isometry conditions for sparse signal and low-rank matrix recovery. The analysis relies on a key technical tool, which represents points in a polytope by convex combinations of sparse vectors. The technique is elementary while yielding sharp results. It is shown that for any given constant t ≥ 4/3, in compressed sensing, δtkA 0, δtkA <; √(t-1/t) + e is not sufficient to guarantee the exact recovery of all k-sparse signals for large k. Similar results also hold for matrix recovery. In addition, the conditions δtkA <; √((t-)1/t) and δtrM <; √((t-1)/t) are also shown to be sufficient, respectively, for stable recovery of approximately sparse signals and low-rank matrices in the noisy case.
Total synthesis of (±)-8′-trifluoromethyl abscisic acid

Abstract While 8′-trifluoromethyl ABA ( 2a ) was known to be one of the most active and stable analogs tested in assays for ABA-like activity, a thorough evaluation of its biological properties was limited by compound availability. The current synthesis, which includes the preparation of a previously unknown key intermediate 2-methyl-2-trifluoromethyl-1,4-cyclohexanedione-mono ethylene ketal ( 18 ), has been accomplished in 14 steps and 3% yield. The key fluorinated ketal intermediate 18 was prepared in six steps and 20% yield.
Combustor development for automotive gas turbines

This paper describes the development of a combustion system for the AGT 100 automotive gas turbine engine. The AGT 100 is a 100 hp engine being developed by Detroit Diesel Allison Division of General Motors Corporation. To achieve optimum fuel economy, the AGT 100 engine operates on a regenerative cycle. A maximum turbine inlet temperature of 1288/sup 0/C (2350/sup 0/F) is reached, and air is supplied to the inlet of the combustor at temperatures as high as 1024/sup 0/C (1875/sup 0/F). To meet the low-emission and high-durability requirements at these conditions, a premix/prevaporization ceramic combustor employing variable geometry to control the temperature in the burning zone has been developed. A test section capable of handling 1024/sup 0/C (1875/sup 0/F) inlet air was designed and fabricated to evaluate this combustor. Testing of both metal (transpiration cooled) and ceramic combustors was conducted. Emissions were measured and found to be a function of burner inlet temperature. At 999/sup 0/C (1830/sup 0/F) burner inlet temperature, NO /SUB x/ emissions were two orders of magnitude below the program goals. At the same temperature but at a different variable-geometry position, the CO was 30 times below the program goal. Considerable testing was conducted to evaluate themore » behavior of the ceramic materials used in the combustor. No failures occurred during steady-state operation; however, some cracks developed in the dome during extended transient operation.« less
Mechanism of Chain Length Determination in Biosynthesis of Milk Fatty Acids

Fatty acid synthetases isolated from all mammalian tissues synthesize pre-dominantly palmitic acid. However, in vivo the mammary gland fatty acid synthetases of some species are responsible for the synthesis of medium chain fatty acids. The objective of this presentation is to outline the mechanism which regulates the product specificity of fatty acid synthetases in general and to illustrate how this control is modified in the mammary gland. Fatty acid synthetases isolated from mammalian tissues are composed of two similar, probably identical, polypeptides, each carrying as many as seven enzyme components. Thioesterase I, the component which functions to terminate growth of acyl chains of the multienzyme, is located at one terminus of each polyfunctional polypeptide and can be detached by limited proteolysis with trypsin. By studying separately the kinetics of chain elongation by the core of the trypsinized complex and of chain termination by the chain thioesterase I component, it has been possible to establish that the specificities of the elongation and termination reactions account for the synthesis of predominantly the carbon-16 fatty acid by purified fatty acid synthetases. Mammary glands for some species contain an additional enzyme, thioesterase II, which can modify the product specificity of fatty acid sunthetase by hydrolyzing medium chain acyl moieties from thioester linkage to the 4'phosphopantetheine of the multienzyme. At all stages of development of rat mammary gland, the amount of theoesterase II present correlates with the proportion of medium chain fatty acids synthesized by the gland. This mammary glad-specific thioesterase appears responsible for the ability of this tissue to synthesize medium chain fatty acids characteristic of milk fat.
Hot-electron energy coupling in ultraintense laser-matter interaction

We investigate the hydrodynamic response of plasma gradients during the interaction with ultraintense energetic laser pulses using kinetic particle simulations. Energetic laser pulses are capable of compressing preformed plasma gradients over short times, while accelerating low-density plasma backward. As light is absorbed on a steepened interface, hot-electron temperature and coupling efficiency drop below the ponderomotive scaling and we are left with an absorption mechanism that strongly relies on the electrostatic potential caused by low-density preformed plasma. We describe this process, discuss properties of the resulting electron spectra and identify the parameter regime where strong compression occurs. Finally, we discuss implications for fast ignition and other applications.
Pd(0)Cu(I) cocatalyzed coupling of methylphenylphosphine-borane with aryl halides and aryl nonaflates

The reaction of Ph(Me)PH•BH3 with aryl halides in the presence of catalytic Pd(OAc)2Ph2PMe and CuI using iPr2NEt as a base in THF at 0 °C furnished the corresponding coupling products in moderate to high yields. A (2-iodophenyl)oxazoline derivative furnished 70% phosphorylated coupling product. Phenyl nonaflate underwent coupling with LiCl as an additive.
Comment on 'Uncertainty in measurements of distance'

We have argued that quantum mechanics and general relativity give a lower bound δl l1/3l2/3P on the measurement uncertainty of any distance l much greater than the Planck length lP. Recently Baez and Olson have claimed that one can go below this bound by attaching the measuring device to a massive elastic rod. Here we refute their claim. We also reiterate (and invite our critics to ponder on) the intimate relationship and consistency between black-hole physics (including the holographic principle) and our bound on distance measurements.
On the theoretical description of weakly charged surfaces

It is widely accepted that the Poisson-Boltzmann (PB) theory provides a valid description for charged surfaces in the so-called weak coupling limit. Here, we show that the image charge repulsion creates a depletion boundary layer that cannot be captured by a regular perturbation approach. The correct weak-coupling theory must include the self-energy of the ion due to the image charge interaction. The image force qualitatively alters the double layer structure and properties, and gives rise to many non-PB effects, such as nonmonotonic dependence of the surface energy on concentration and charge inversion. In the presence of dielectric discontinuity, there is no limiting condition for which the PB theory is valid.
Regularly spaced subsums of integer partitions

For integer partitions $\lambda :n=a_1+...+a_k$, where $a_1\ge a_2\ge >...\ge a_k\ge 1$, we study the sum $a_1+a_3+...$ of the parts of odd index. We show that the average of this sum, over all partitions $\lambda$ of $n$, is of the form $n/2+(\sqrt{6}/(8\pi))\sqrt{n}\log{n}+c_{2,1}\sqrt{n}+O(\log{n}).$ More generally, we study the sum $a_i+a_{m+i}+a_{2m+i}+...$ of the parts whose indices lie in a given arithmetic progression and we show that the average of this sum, over all partitions of $n$, is of the form $n/m+b_{m,i}\sqrt{n}\log{n}+c_{m,i}\sqrt{n}+O(\log{n})$, with explicitly given constants $b_{m,i},c_{m,i}$. Interestingly, for $m$ odd and $i=(m+1)/2$ we have $b_{m,i}=0$, so in this case the error term is of lower order. The methods used involve asymptotic formulas for the behavior of Lambert series and the Zeta function of Hurwitz. We also show that if $f(n,j)$ is the number of partitions of $n$ the sum of whose parts of even index is $j$, then for every $n$, $f(n,j)$ agrees with a certain universal sequence, Sloane's sequence \texttt{#A000712}, for $j\le n/3$ but not for any larger $j$.
Stellar populations in the large Magellanic Cloud from 2MASS

We present a morphological analysis of the feature-rich 2MASS LMC color-magnitude diagram, identifying Galactic and LMC populations and estimating the density of LMC populations alone. We also present the projected spatial distributions of various stellar populations. The conditions that prevailed when 2MASS observed the LMC provided 10 σ limiting sensitivity for J 16.3, H 15.3, and Ks 14.7. Major populations are identified based on matching morphological features of the color-magnitude diagram with expected positions of known populations, isochrone fits, and analysis of the projected spatial distributions. 2MASS has detected a significant population of asymptotic giant branch (AGB) stars (104 sources) and obscured AGB stars (2 × 103 sources). The LMC populations along the first-ascent red giant branch (RGB) and AGB are quantified. Comparison of the giant luminosity functions in the bar and the outer regions of the LMC shows that both luminosity functions appear consistent with each other. The luminosity function in the central (bar) field has well-defined drop-off near Ks = 12.3 mag corresponding to the location of the RGB tip; the same feature is seen in the luminosity function of the entire LMC field. Isochrone fits for the corresponding giant branches reveal no significant differences in metallicities and ages between central and outer regions of the LMC. This may be evidence for strong dynamical evolution in the last several gigayears. In particular, the observed LMC giant branch is well fit by published tracks in the CIT/CTIO system with a distance modulus of μ = 18.5 ± 0.1, reddening EB-V = 0.15-0.20, metallicity Z = 0.004, and age 3-13 Gyr. Analysis of deep 2MASS engineering data with 6 times the standard exposure produces similar estimates.
A Test System to Quantify Inoculum in Runoff from Phytophthora ramorum-Infected Plant Roots

ABSTRACT Foliar hosts of Phytophthora ramorum are often susceptible to root infection but the epidemiological significance of such infections is unknown. A standardized test system was developed to quantify inoculum in runoff from root-infected Viburnum tinus ‘Spring Bouquet’ or Rhododendron ‘Cunningham's White’ cuttings. Cuttings of both species gave off a maximum amount of inoculum 1 to 3 weeks after inoculation. The greatest amount of inoculum was recovered from Viburnum roots that were 48 to 70 days old at the time of inoculation, or roots incubated at 15 to 20°C rather than 25°C. Inoculum in runoff from inoculated Viburnum roots was similar for four different isolates of P. ramorum representing both the NA1 and EU1 lineages. When Rhododendron cuttings were inoculated with P. ramorum, P. citricola, or P. cactorum, inoculum of all three pathogens was recovered from runoff, with the highest amount recovered from plants inoculated with P. citricola, followed by the other two. Compared with the other two ...
Integration and approximation of multivariate functions: average case complexity with isotropic Wiener measure

Abstract We study the average case complexity of multivariate integration and L 2 function approximation for the class F = C ([0, 1] d ) of continuous functions of d variables. The class F is endowed with the isotropic Wiener measure (Brownian motion in Levy′s sense). For the integration problem, the average case complexity of solving the problem to within ϵ is proportional to ϵ -2/(1 + 1/ d ) . This is a negative result since for a large number d of variables, the average case complexity is close to ϵ −2 ; the latter is also achieved by the classical Monte Carlo method in the randomized worst case setting. Furthermore, Θ(ϵ −2 ) is the highest possible average case complexity among all probability measures with finite expectation of || ƒ 2 L 2 . Thus, for large d , the average case complexity of the integration problem with isotropic Wiener measure behaves as the worst possible average complexity. For the function approximation problem, the complexity is even higher since it is proportional to ϵ −2 d . These two negative results are in a sharp contrast to (H. Woźniakowski, Bull. Amer. Math. Soc. 24 , No. 1 (1991), 185-194; Bull. Amer. Math. Soc. , to appear), where, for F endowed with the Wiener sheet measure, small average case complexities have been proven. Indeed, they are of order ϵ −1 (log ϵ −1 ) ( d −1)/2 and ϵ −2 (log ϵ −1 ) 2( d −1) for the integration and function approximation problems, respectively. cccc
Classical calculation of correlation functions in a one-dimensional Fermi gas

The response functions of the one-dimensional Fermi gas with backscattering are studied using an equivalence of the spin-density part of the Fermi Hamiltonian to the sine-Gordon Hamiltonian. The singlet spin-density response function is evaluated in functional-integral form, using a transfer-matrix technique. For low temperatures and large distances, this function is found to be unity. The triplet response function is found, in a harmonic approximation, to be zero. These results support the proposal by Luther and Emery that the singular behavior of the Fermi-gas response functions is determined solely by the charge-density modes. Also supported is the rather intuitive picture, based on a mapping to the two-dimensional Coulomb gas, of Chui and Lee.
Distributional Implications of U.S. Ethanol Policy

The U.S. ethanol industry is at a crossroads. In its favor is that Congress is poised to pass an increase in the renewable fuel standard (RFS) in the pending Energy Bill. Such an expansion would guarantee a market for all the ethanol that could be produced from plants currently operating and plants in various phases of construction. The industry desperately desires an expansion in the RFS because of a cost-price squeeze. Costs are up because the industry's rapid expansion (and the promise of more expansion in the future) has increased the cash cost of corn to $4.00 per bushel. Ethanol prices are down because of infrastructure bottlenecks and the need to compete with gasoline directly as a substitute rather than as a complement in a gasoline blend. The margin squeeze has reduced the financial incentives to complete all the ethanol plants that are under construction. But Congressional approval of an expansion of the RFS is not a certainty. The U.S. livestock industry has launched an aggressive public campaign against ethanol in an attempt to both forestall the RFS expansion as well as to rollback current government incentives. A large adjustment in ethanol production and corn prices would likely occur if the livestock industry has its way. The purpose of this study is to estimate the magnitude of the transfers and the associated welfare changes that are involved in the use of corn to supply a significant portion of the U.S. transportation fuel supply. To accomplish this objective requires estimates of prices and quantities with and without ethanol. There are few existing studies on this topic. Gardner recently estimated the welfare analysis of ethanol subsidies relative to a deficiency payment program for corn farmers. He analyzes the removal of the $0.51 per gallon blender's tax credit in both the short and the long run. He concludes that in the short run, the
Theory of the negative isotope effect on copper in underdoped YBCO

Abstract An explanation is proposed of the negative isotope effect observed on copper in underdoped YBa 2 Cu 3 O 7− δ . Calculations show that such an effect can be due to scattering of electrons from low-frequency phonons, which are not associated with oscillations of the total ionic charge density. The negative isotope effect is specific for superconducting layered cuprates with a d-wave order parameter and is absent in s-type superconductors of the same kind. Although the theory does not reproduce all observed features of the dependence of the isotope effect on oxygen concentration, it agrees qualitatively with the general trend of enhancement with decreasing T c . A discussion is presented, and several possible experiments are proposed.
Experimental data on page replacement algorithm

Although paged VM (Virtual Memory) systems are being implemented more and more, their full capabilities have not yet been realized. Early research in this field pointed to possible inefficiencies in their implementation. Subsequent studies, however, led to the conclusion that paged VM systems could provide a productive means to run large programs on small main memory, if proper techniques are employed. One of the most influential of these is the choice of an efficient page replacement algorithm (RA) to minimize page traffic between the different levels of memory.
A Ricardian Model of New Trade and Location Theory

This paper provides a new model of firm’s location choices. It integrates a Ricardian model of comparative advantage with the location effects deriving from trade costs, increasing returns to scale, product dif ferentiation, and monopolistic competition. In a two-region, two-differentiated-good, one-factor framework, the regional degree of specialization depends positively on the extent of the comparative advantage in productivity and on the degree of returns to scale; it depends negatively on the magnitude of the trade costs. Hence, the model accommodates high levels of intra-industry trade among countries with similar level of development, as well as high levels of interindustry trade among countries with different technologies.
QCD Instantons and 2d Surfaces

Some time ago, Atiyah showed that there exists a natural identification between the k-instantons of a Yang-Mills theory with gauge group G and the holomorphic maps from CP1 to ΩG. Since then, Nair and Mazur have associated the Θ vacua structure in QCD with self-intersecting Riemann surfaces immersed in four dimensions. From here they concluded that these 2D surfaces correspond to the non-perturbative phase of QCD and carry the topological information of the Θ vacua. In this paper we would like to elaborate on this point by making use of Atiyah’s identification. We will argue that an effective description of QCD may be more like a WZW model coupled to the induced metric of an immersion of a 2D Riemann surface in R4. We make some further comments on the relationship between the coadjoint orbits of the Kac-Moody group on G and instantons with axial symmetry and monopole charge.
Indirect production function and the output effect of Public transit subsidies

This paper uses an indirect production function to decompose the effects of subsidies on output into the lump-sum, cost and inefficiency effects. Using 2006 data for U.S. transit systems it estimates an indirect production function and uses the results to calculate these effects. It finds that the lump-sum effects exceed the other effects and that the average total effect of the subsidies is a 4.72% increase in output. The range of the output change shows that in many transit systems the output increases from the subsidies are quite large. The paper suggests that reductions in allocative inefficiencies from the subsidies would result in very large increases in output.
Reserves and Baskets

We discuss three well known plans that were offered in the twentieth century to provide an artificial replacement for gold and key currencies as international reserves: Keynes’ Bancor, the SDR and the Ecu(predecessor to the euro).The latter two of these reserve substitutes were institutionalized but neither replaced the dollar as the principal medium of international reserve.
Instructional Case: Estimating Learning‐Curve Functions for Managerial Planning, Control, and Decision‐Making

ABSTRACT: Elora Electronics, Limited (EEL), a fictitious company, manufactures sophisticated, high‐tech electronic equipment. Though successful in the past, the company has seen a decline in the number of bids it has won. Management is especially concerned about the bids the company recently lost on one of its main products, a sophisticated radar system. Most of the contracts for EEL, including those for the radar system, are bid on a “cost‐plus” basis. Up to this point, divisional managers have used a simple average of recent actual costs to estimate costs for contract‐bidding purposes. Such a procedure was deemed useful for cost‐control purposes because actual costs have consistently been below budgeted costs. However, given the changed competitive environment in which EEL now finds itself, these managers are now wondering whether the contract‐bidding process can be made more successful through the use of a more sophisticated approach to cost estimation. For purposes of completing this case, assume that...
Peticiones de asilo basadas en cuestiones de sexualidad: algunas respuestas y muchas preguntas

Actualmente muchos sistemas legales aceptan que las personas gay, lesbianas, bisexuales y transexuales ("LGBT") tambien pueden obtener asilo, nonrefoulement o que se declare temporalmente su no devolucion (segun las leyes de EE.UU.) o proteccion judicial conforme a la Convencion contra la Tortura debido a su orientacion o comportamiento sexual. Ya sea que uno considere este hecho como un suceso revolucionario o como el desarrollo natural de los derechos humanos y el derecho de los refugiados, evidentemente quedan muchas preguntas sin responder. El articulo destaca y evalua algunas de las principales interrogantes y tensiones existentes en el estado actual de la legislacion, en particular el hecho de que el tema del asilo basado en la orientacion sexual de la persona implica muchas de las mas profundas tensiones que yacen debajo de la superficie del derecho de los derechos humanos en general como tambien del derecho de refugio y de asilo.
Diffraction coupled phase-locked semiconductor laser array

A new monolithic, diffraction coupled phase‐locked semiconductor laser array has been fabricated. Stable narrow far‐field patterns (∼3°) and peak power levels of 1 W have been obtained for 100‐μm‐wide devices with threshold currents as low as 250 mA. Such devices may be useful in applications where high power levels and stable radiation patterns are needed.
Facial reanimation of patients with neurofibromatosis type 2.

Background Neurofibromatosis type 2 (NF2) is a tumor suppressor syndrome defined by bilateral vestibular schwannomas. Facial paralysis, from either tumor growth or surgical intervention, is a devastating complication of this disorder and can contribute to disfigurement and corneal keratopathy. Historically, physicians have not attempted to treat facial paralysis in these patients. Objective To review our clinical experience with free gracilis muscle transfer for the purpose of facial reanimation in patients with NF2. Methods Five patients with NF2 and complete unilateral facial paralysis were referred to the facial nerve center at our institution. Charts and operative reports were reviewed; treatment details and functional outcomes are reported. Results Patients were treated between 2006 and 2009. Three patients were men and 2 were women. The age of presentation of debilitating facial paralysis ranged from 12 to 50 years. All patients were treated with a single-stage free gracilis muscle transfer for smile reanimation. Each obturator nerve of the gracilis was coapted to the masseteric branch of the trigeminal nerve. Measurement of oral commissure excursions at rest and with smile preoperatively and postoperatively revealed an improved and nearly symmetric smile in all cases. Conclusion Management of facial paralysis is often times overlooked when defining a care plan for NF2 patients who typically have multiple brain and spine tumors. The paralyzed smile may be treated successfully with single-stage free gracilis muscle transfer in the motivated patient.
Adaptivity in agent-based routing for data networks

Adaptivity, both of the individual agents and of the interaction structure among the agents, seems indispensable for scaling up multi-agent systems (MAS s) in noisy environments. One important consideration in designing adaptive agents is choosing their action spaces to be as amenable as possible to machine learning techniques, especially to reinforcement learning (RL) techniques. One important way to have the interaction structure connecting agents itself be adaptive is to have the intentions and/or actions of the agents be in the input spaces of the other agents, much as in Stackelberg games. We consider both kinds of adaptivity in the design of a MAS to control network packet routing. We demonstrate on the OPNET event-driven network simulator the perhaps surprising fact that simply changing the action space of the agents to be better suited to RL can result in very large improvements in their potential performance: at their best settings, our learning-amenable router agents achieve throughputs up to three and one half times better than that of the standard Bellman-Ford routing algorithm, even when the Bellman-Ford protocol traffic is maintained. We then demonstrate that much of that potential improvement can be realized by having the agents learn their settings when the agent interaction structure is itself adaptive.
Progress in lattice field theory algorithms

Abstract I present a summary of recent algorithmic developments for lattice field theories. In particular I give a pedagogical introduction to the new Multicanonical algorithm, and discuss the relation between the Hybrid Overrelaxation and Hybrid Monte Carlo algorithms. I also attempt to clarify the role of the dynamical critical exponent z and its connection with “computational cost.”
Causes and Costs of Spinal Cord Injury in the United States

A cross-sectional multicenter study was conducted to estimate the direct costs for each cause of spinal cord injury in the United States. Random samples of 227 new injuries and 508 persons 2-16 years postinjury were selected. Prospective data were collected during one year on all charges for emergency medical services, hospitalizations, attendant care, equipment, supplies, medications, environmental modifications, physician and outpatient services, nursing homes, household assistance, vocational rehabilitation, and miscellaneous items. In 1995 dollars, first year charges averaged $233,947 for vehicle crashes, $217,868 for violence, $295,643 for sports, $185,019 for falls and $208,762 for other causes. Recurring annual charges for each cause averaged $33,439, $17,275, $27,488, $26,238 and $23,510, respectively. Using average age at time of injury for each cause, a 2% real discount rate, and the most recent survival data from the National Spinal Cord Injury Statistical Center, average lifetime charges for each cause were $969,659, $613,345, $950,973, $630,453 and $673,749, respectively. Given an estimated 10,000 new cases of spinal cord injury occurring each year of which 35.9% are caused by vehicle crashes, 29.5% are caused by violence, 20.3% are caused by falls, 7.3% are caused by sports, and 7% result from other causes, annual aggregate direct costs of traumatic spinal cord injury in the United States are $3.48 billion for vehicle crashes, $1.81 billion for violence, $1.28 billion for falls, $694 million for sports and $472 million for other causes. Total direct costs for all causes of SCI in the United States are $7.736 billion.
Total Syntheses of Vincadifformine, 3-Oxovincadifformine, Pseudo- and 20-epi-Pseudovincadifformine, Tabersonine, and Δ18-Tabersonine through Radical Reactions and Heck Reactions

The pentacyclic alkaloids vincadifformine (9), ψ-vincadifformine (15), and epi-ψ-vincadifformine (16) could be synthesized by intramolecular free-radical-induced cyclizations of the tetracyclic intermediates 7, 8, and 18, which were respectively obtained by condensation of the indoloazepine 1 with 2-(phenylselenyl)butyraldehyde and subsequent Nb-alkylation of the resulting tetracyclic amines 2 and 3, or from condensation of (phenylselenyl)acetaldehyde with the alkylated indoloazepine 17. The intermediates 2 and 3 also gave 3-oxovincadifformine (21) by an intermolecular radical alkylation with methyl acrylate. Their alkylation with (Z)-1,3-diiodopropene, phenyl selenoxide elimination, and intramolecular Heck reactions provided tabersonine (24) and 18,19-didehydrotabersonine (27).
Stock Market Participation and the Internet

Theory indicates that frictions (e. g., information and transaction costs) could account for the lower than expected stock market participation rates. This paper examines the hypothesis that there has been a fundamental change in participation and links this change to the reduction of these frictions by the advent of the Internet. Using panel data on household participation rates over the past decade, the results show computer/Internet using households raised participation substantially more than non-computer using households. The increased probability of participation was equivalent to having over $27,000 in additional household income or over two more mean years of education.
Attitudes toward stereotypical versus counterstereotypical gay men and lesbians

This study examined differences in the way heterosexual men and women feel about gay men and lesbians who either confirm or disconfirm prevailing stereotypes. Fifty-three heterosexual college men and women read descriptions about 2 fictitious homosexual students at their university, both of whom were either male or female. One of the students was portrayed as being more stereotypically masculine, whereas the other was portrayed as more stereotypically feminine. Participants rated the targets on a variety of dimensions, including liking. Male participants liked the masculine gay man more than the feminine gay man, whereas female participants showed similar degrees of liking for both men. Both male and female participants reported greater liking for the feminine lesbian than the masculine lesbian. Implications for understanding attitudes toward stereotypical versus counterstereotypical gay men and lesbians are discussed.
Acts of God: The Unnatural History of Natural Disaster in America

Incredibly, the ten most costly catastrophes in US history have all been natural disasters - seven of them hurricanes - and all have occurred since 1989, a period, ironically, that Congress has dubbed the Decade for Natural Disaster Reduction. Why this tremendous plague on our houses? While some claim that nature is the problem, in fact, as environmental historian Ted Steinberg explains, historically speaking, much of the death and destruction has been well within the realm of human control. Surveying more than a century of losses from weather and seismic extremes, Steinberg exposes the fallacy of seeing such calamities as simply random events. Acts of God explores the unnatural history of natural calamity, the decisions of business leaders and government officials that have paved the way for the greater losses of life and property, especially among those least able to withstand such blows - America's poor, elderly, and minorities. Seeing nature or God as the primary culprit, Steinberg argues, has helped to paper over the fact that, in truth, some Americans are better protected from the violence of nature than their counterparts lower down the socioeconomic ladder. How else can we explain that the hardest hit areas have been mobile home parks and other low-income neighbourhoods? Beginning with the 1886 Charleston and 1906 San Francisco earthquakes, and continuing to the present, Steinberg spotlights the defective approach to natural hazards taken by real estate interests, the media, and policymakers. By understating the extent of storm damage in news reports and offering quick repairs and cosmetic solutions to damaged property, fundamental flaws in the status quo go unremedied, class divisions are maintained, and unsafe practices continue unquestioned. Even today, with our increased scientific knowledge, he shows that reckless building continues unabated in seismically active areas and flood-prone coastal plains, often at taxpayer expense. Sure to provoke discussion, Acts of God is a call to action that must be heard before the next disaster hits.
Environmental Degradation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)

Herbicide formulations containing known amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and exposed to natural sunlight on leaves, soil, or glass plates lost most or all of the TCDD during a single day, due principally to photochemical dechlorination. Despite the known persistence of pure TCDD, it is not stable as a contaminant in thin herbicide films exposed to outdoor light.
An index inequality for embedded pseudoholomorphic curves in symplectizations

Let Σ be a surface with a symplectic form, let φ be a symplectomorphism of Σ, and let Y be the mapping torus of φ. We show that the dimensions of moduli spaces of embedded pseudoholomorphic curves in ℝ×Y, with cylindrical ends asymptotic to periodic orbits of φ or multiple covers thereof, are bounded from above by an additive relative index. We deduce some compactness results for these moduli spaces.¶This paper establishes some of the foundations for a program with Michael Thaddeus, to understand the Seiberg-Witten Floer homology of Y in terms of such pseudoholomorphic curves. Analogues of our results should also hold in three dimensional contact topology.
Rate of pregnanediol excretion following intraportal or intrasystemic intravenous administration of progesterone in human subjects.

INTRODUCTION THE in activation of progesterone and its conversion to pregnane-3α-20α-diol by the liver, is by now a well documented fact. In the studies of Masson and Hoffman (1) and Ferin and Merteus (2), progesterone was found to be much less effective in inducing progestational proliferation in the rabbit uterus after oral than after parenteral administration; but its oral effectiveness increased ten-fold after partial hepatectomy (1). Similar findings were obtained earlier by Kochakian, Haskins and Bruce (3). (En gel (4), however, observed practically no difference, except with very small doses, in the effectiveness of progesterone in this reaction when the intraportal was compared with the systemic route of administration.) Dosne (5) similarly found progesterone less effective in preventing fibrotic changes in guinea-pig uteri after implantation of progesterone pellets in the spleen than after subcutaneous implantation. Selye and Stone (6) showed that the anesthetic effect of this hormone was decreas...
The IPO market as a screening device and the going public decision: evidence from acquisitions of privately and publicly held firms

The main purpose of this paper is using a unique data set from IPO filings to study the IPO market as a screening device and the going public decision. We find that private firms that are less likely to have the option to access public equity markets receive 54 cents for each dollar they expected to raise in an IPO, whereas firms that are more likely to have the option to go public but sell privately sell at $1.11 for each dollar they expected to receive at the IPO. This result suggests that the lower valuation for firms sold in private markets compared to firms sold in public markets can be at least partially explained by the lower relative bargaining power of private firms. However, owners that took their firms public before selling received, on average, 40% larger payoffs than owners that had the option to go public but decided to sell privately. The results in this study indicate that these differences in valuation are not fully explained by existing theoretical models on the decision to sell privately or in two stages.
Smoking, Expectations, and Health: A Dynamic Stochastic Model of Lifetime Smoking Behavior

I estimate a dynamic, stochastic model of smoking, expectations, and health that makes explicit channels through which an individual may learn about the health risks of smoking. Simulations of the structural model suggest that cardiovascular biomarker information at repeated health exams does not significantly alter smoking behavior because (a) signals of biomarker health are noisy within individuals, (b) the influence of biomarkers on major health outcomes is small, and (c) cigarette smoking is addictive. This paper also presents evidence of selection in smoking that, when not modeled, may cause an overstatement of the effect of smoking on expected longevity.
X-Ray-emitting Young Stars in the Orion Nebula

The Orion Nebula Cluster and the molecular cloud in its vicinity have been observed with the ACIS-I detector on board the Chandra X-ray Observatory with 23 hr exposure in two observations. We detect 1075 X-ray sources, most with subarcsecond positional accuracy. Ninety-one percent of the sources are spatially associated with known stellar members of the cluster, and an additional 7% are newly identified deeply embedded cloud members. This provides the largest X-ray study of a pre-main-sequence stellar population and covers the initial mass function from brown dwarfs up to a 45 M☉ O star. Source luminosities span 5 orders of magnitude from log L_X ≃ 28.0 to 33.3 ergs s^(-1) in the 0.5-8 keV band, plasma energies range from 0.2 to >10 keV, and absorption ranges from log N_H < 20.0 to ~23.5 cm^(-2). Comprehensive tables providing X-ray and stellar characteristics are provided electronically. We examine here the X-ray properties of Orion young stars as a function of mass; other studies of astrophysical interest will appear in companion papers. Results include: (a) the discovery of rapid variability in the O9.5 31 M☉ star θ^2A Ori, and several early B stars, inconsistent with the standard model of X-ray production in small shocks distributed throughout the radiatively accelerated wind; (b) support for the hypothesis that intermediate-mass mid-B through A type stars do not themselves produce significant X-ray emission; (c) confirmation that low-mass G through M type T Tauri stars exhibit powerful flaring but typically at luminosities considerably below the "saturation" level; (d) confirmation that the presence or absence of a circumstellar disk has no discernable effect on X-ray emission; (e) evidence that T Tauri plasma temperatures are often very high with T ≥ 100 MK, even when luminosities are modest and flaring is not evident; and (f) detection of the largest sample of pre-main-sequence very low-mass objects showing flaring levels similar to those seen in more massive T Tauri stars and a decline in magnetic activity as they evolve into L and T type brown dwarfs.