cssi/SciSciGPT-SciSciNet huggingface dataset:
Classroom Techniques in Teaching by the Case Method

In this article the author outlines a method, which builds on pervious research on teaching by case method, for conducting a successful classroom discussion in a business policy course. He notes that teaching is largely an individual process; however, building a framework is important, especially for longer courses. The author outlines a three step process for establishing this framework starting with course design, class preparation and finally a method of conducting class discussions. He provides extensive details into each of these areas, essentially presenting an overview on how to conduct a class from beginning to end. He closes by noting that to effectively teach by case method the instructor must be fully prepared.
Efficient methodology for multibody simulations with discontinuous changes in system definition

A new method is presented for accurately and efficiently simulating multi-scale multibody systems with discontinuous changes in system definitions as encountered in adaptive switching between models with different resolutions as well as models with different system topologies. An example of model resolution change is a transition of a system from a discrete particle model to a reduced order articulated multi-rigid body model. The discontinuous changes in system definition may be viewed as an instantaneous change (release or impulsive application of) the system constraints. The method uses a spatial impulse–momentum formulation in a divide and conquer scheme. The approach utilizes a hierarchic assembly–disassembly process by traversing the system topology in a binary tree map to solve for the jumps in the system generalized speeds and the constraint impulsive loads in linear and logarithmic cost in serial and parallel implementations, respectively. The method is applicable for systems in serial chain as well as kinematical loop topologies. The coupling between the unilateral and bilateral constraints is handled efficiently through the use of kinematic joint definitions. The equations of motion for the system are produced in a hierarchic sub-structured form. This has the advantage that changes in sub-structure definitions/models results in a change to the system equations only within the associated sub-structure. This allows for significant changes in model types and definitions without having to reformulate the equations for the whole system.
Collateral restrictions and liquidity under-supply: a simple model

We show that very little is needed to create liquidity under-supply in equi- librium. Credit constraints on demand by themselves can cause an under-supply of liquidity, without the uncertainty, intermediation, asymmetric information or compli- catedinternationalfinancialframeworkusedinothermodelsintheliterature.Weshow that the under-supply is a non-monotone function of the demand distortion that causes it, a result that may have interesting implications for emerging markets economies. Finally, when we make the credit constraint endogenous, the inefficiency can be large due to the presence of a multiplier.
Regio- and Diastereoselective Insertion of Allenes into Stable Oxapalladacycles with a Metal-Bonded Stereogenic Carbon. Preparation of Contiguously Substituted 3,4-Dihydro-2H-1-Benzopyrans

Insertion of monosubstituted allenes into stable oxapalladacycle I was studied. The aim of this work was to define steric and electronic parameters of allenes that would allow for a regio- and diastereoselective synthesis of 2,3-disubstituted 3,4-dihydro-2H-1-benzopyrans, which could not be prepared via related catalytic protocols. Allenes with electron-donating alkyl substituents R sterically unencumbered at the C-3 and C-4 carbons reacted with palladacycles I to afford benzopyrans IV in good yields (45-81%), exclusively as cis diastereomers. Less than 10% of the regioisomeric benzopyrans V was detected in the crude reaction mixtures. Methoxy 1,2-propadiene afforded benzopyran IV in 98% yield as the trans diastereomer in 92% de. In contrast, allenes with electron-withdrawing substituents yielded benzopyrans V with an E double bond exclusively. Nonracemic palladacycles featuring a palladium-bonded stereogenic carbon as the only element of asymmetry underwent the allene insertion with 63-93% retention of the stereochemical information, providing benzopyrans IV or V in 40-47% ee. These results demonstrated that O-bonded palladium enolates did not operate as predominant intermediates in the insertion process. The study highlights the configurational stability of carbon-bonded palladium ester enolates, especially notable in systems lacking chiral nonracemic auxiliary ligands.
Spectrally encoded photoacoustic microscopy using a digital mirror device

We have developed spectrally encoded photoacoustic microscopy using a digital mirror device for multi-wavelength tomography, which enables fast spectral imaging of optical absorption. The optical illumination wavelengths are multiplexed at a laser pulse repetition rate of ∼2 kHz. Liquid samples, whole blood, and blood vessels in mouse ears were imaged. Compared with internal wavelength tuning of a narrow-band laser, external wavelength tuning based on a digital mirror device improves the data acquisition speed of spectral photoacoustic microscopy. Compared with external wavelength scanning of a wide-band laser with the same pulse energy, spectral encoding improves the signal-to-noise ratio.
Oxadiazinones as chiral auxiliaries: increased diastereoselectivities in the glycolate aldol reaction of oxadiazinones☆

Abstract Glycolate aldol reactions were conducted using a (1R,2S)-norephedrine based N4-isopropyloxadiazinone as a chiral template to afford aldol adducts 8a–h. The yields ranged from 57% to 99% while the diastereoselectivities ranged from 94:6 to 99:1. Adduct 8a was hydrolyzed to afford the oxadiazinone auxiliary and β-hydroxyacid 9, which was converted to the known methyl (2S,3R)-2,3-dihydroxy-3-phenylpropionate 12 with 95% ee as determined by chiral HPLC.
Scan-based attacks on linear feedback shift register based stream ciphers

Stream cipher is an important class of encryption algorithm that encrypts plaintext messages one bit at a time. Various stream ciphers are deployed in wireless telecommunication applications because they have simple hardware circuitry, are generally fast and consume very low power. On the other hand, scan-based Design-for-Test (DFT) is one of the most popular methods to test IC devices. All flip-flops in the Design Under Test are connected to one or more scan chains and the states of the flip-flops can be scanned out through these chains. In this paper, we present an attack on stream cipher implementations by determining the scan chain structure of the Linear Feedback Shift Registers in their implementations. Although scan-based DFT is a powerful testing scheme, we show that it can be used to retrieve the information stored in a crypto chip thus compromising its theoretically proven security.
Philosophical Implications of Inflationary Cosmology

Recent developments in cosmology indicate that every history having a nonzero probability is realized in infinitely many distinct regions of spacetime. Thus, it appears that the universe contains infinitely many civilizations exactly like our own, as well as infinitely many civilizations that differ from our own in any way permitted by physical laws. We explore the implications of this conclusion for ethical theory and for the doomsday argument. In the infinite universe, we find that the doomsday argument applies only to effects which change the average lifetime of all civilizations, and not those which affect our civilization alone.
GeV-scale dark matter: production at the Main Injector

Assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z ′ boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NOνA near detector is well positioned for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.
Quantum Singularities in Conformally Static Spacetimes

After a brief review of the standard definition and analysis of classical singularities in general relativistic spacetimes, and of quantum singularities in static spacetimes with timelike classical singularities, an extension of quantum singularities to conformally static spacetimes is summarized and applied to two test cases. The timelike classical singularities in a Friedmann-Robertson-Walker (FRW) universe with a cosmic string, and in Roberts spacetime, are shown to be quantum mechanically singular when tested by either minimally coupled or conformally coupled scalar waves. In the Roberts case, however, non-minimally coupled scalar waves with a coupling constant \(\xi \ge 2\) do not detect the classical singularity.
Laminating Lattices with Symmetrical Glue

We use the automorphism group Aut(H), of holes in the lattice L 8=A 2 ⊕ A 2 ⊕ D 4, as the starting point in the construction of sphere packings in 10 and 12 dimensions. A second lattice, L 4=A 2 ⊕ A 2, enters the construction because a subgroup of Aut(L 4) is isomorphic to Aut(H). The lattices L 8 and L 4, when glued together through this relationship, provide an alternative construction of the laminated lattice in twelve dimensions with kissing number 648. More interestingly, the action of Aut(H) on L 4 defines a pair of invariant planes through which dense, non-lattice packings in 10 dimensions can be constructed. The most symmetric of these is aperiodic with center density 1/32. These constructions were prompted by an unexpected arrangement of 378 kissing spheres discovered by a search algorithm.
Rh-catalyzed enantioselective diboration of simple alkenes: reaction development and substrate scope.

The rhodium-catalyzed reaction between bis(catecholato)diboron and simple alkenes results in the syn addition of the diboron across the alkene. The resulting 1,2-bis(boronate) is subsequently oxidized to provide the 1,2-diol. In the presence of enantiomerically enriched Quinap ligand, high enantioselection in the diboration can be achieved. The reaction is highly selective for trans- and trisubstituted alkenes and can be selective for some monosubstituted alkenes as well. The development of this reaction is described as is the substrate scope and experiments that are informative about the reaction mechanism and competing pathways.
A Comparison of Breeding and Ensemble Transform Kalman Filter Ensemble Forecast Schemes

Abstract The ensemble transform Kalman filter (ETKF) ensemble forecast scheme is introduced and compared with both a simple and a masked breeding scheme. Instead of directly multiplying each forecast perturbation with a constant or regional rescaling factor as in the simple form of breeding and the masked breeding schemes, the ETKF transforms forecast perturbations into analysis perturbations by multiplying by a transformation matrix. This matrix is chosen to ensure that the ensemble-based analysis error covariance matrix would be equal to the true analysis error covariance if the covariance matrix of the raw forecast perturbations were equal to the true forecast error covariance matrix and the data assimilation scheme were optimal. For small ensembles (∼100), the computational expense of the ETKF ensemble generation is only slightly greater than that of the masked breeding scheme. Version 3 of the Community Climate Model (CCM3) developed at National Center for Atmospheric Research (NCAR) is used to test ...
Radial transport in the solar nebula: Implications for moderately volatile element depletions in chondritic meteorites

In this paper, we explore the possibility that the moderately volatile element depletions observed in chondritic meteorites are the result of planetesimals accreting in a solar nebula that cooled from an initially hot state (temperatures >1350 K out to ~2-4 AU). A model is developed to track the chemical inventory of planetesimals that accrete in a viscously evolving protoplanetary disk, accounting for the redistribution of solids and vapor by advection, diffusion, and gas drag. It is found that depletion trends similar to those observed in the chondritic meteorites can be reproduced for a small range of model parameters. However, the necessary range of parameters is inconsistent with observations of disks around young stars and other constraints on meteorite parent body formation. Thus, counter to previous work, it is concluded that the global scale evolution of the solar nebula is not the cause for the observed depletion trends. Instead, it appears that localized processing must be considered.
International Patenting and Technology Diffusion

We model the invention of new technologies and their diffusion across countries. Our model predicts that, eventually, all countries will grow at the same rate, with each country's productivity ranking determined by how rapidly it adopts inventions. The common growth rate depends on research efforts in all countries, while research effort is determined by how much inventions earn at home and abroad. Patents affect the return to invention. We relate the decision to patent an invention internationally to the cost of patenting in a country and to the expected value of patent protection in that country. We can thus infer the direction and magnitude of the international diffusion of technology from data on international patenting, productivity, and research. We fit the model to data from the five leading research economies. The parameters indicate how much technology flows between these countries and how much each country earns from its inventions domestically and elsewhere. Our results imply that foreign countries are important sources of technology even though countries earn most of their return to innovation at home. For example, about half of U.S. productivity growth derives from foreign technology yet U.S. investors earn 98 per cent of the revenue from their inventions domestically.
Super W-symmetries, covariantly constant forms and duality transformations

Abstract On a supersymmetric sigma model the covariantly constant forms are related to the conserved currents that are generators of a super W -algebra extending the superconformal algebra. The existence of covariantly constant forms restricts the holonomy group of the manifold. Via duality transformation we get new covariantly constant forms, thus restricting the holonomy group of the new manifold.
Measurement-only topological quantum computation via tunable interactions

I examine, in general, how tunable interactions may be used to perform anyonic teleportation and generate braiding transformations for non-Abelian anyons. I explain how these methods are encompassed by the ``measurement-only'' approach to topological quantum computation. The physically most relevant example of Ising anyons or Majorana zero modes is considered in detail, particularly in the context of Majorana nanowires.
Semi-global stabilization of discrete-time linear systems with position and rate limited actuators

It is shown via explicit construction of feedback laws that, if a discrete-time linear system is asymptotically null controllable with bounded controls, then, when subject to both actuator position and rate saturation, it is semi-globally stabilizable by linear state feedback. If, in addition, the system is also detectable, then it is semi-globally stabilizable via linear output feedback.
Changes in Zonal Surface Temperature Gradients and Walker Circulations in a Wide Range of Climates

Variations in zonal surface temperature gradients and zonally asymmetric tropical overturning circulations (Walker circulations) are examined over a wide range of climates simulated with an idealized atmospheric general circulation model (GCM). The asymmetry in the tropical climate is generated by an imposed ocean energy flux, which does not vary with climate. The range of climates is simulated by modifying the optical thickness of an idealized longwave absorber (representing greenhouse gases). The zonal surface temperature gradient in low latitudes generally decreases as the climate warms in the idealized GCM simulations. A scaling relationship based on a two-term balance in the surface energy budget accounts for the changes in the zonally asymmetric component of the GCM-simulated surface temperature. The Walker circulation weakens as the climate warms in the idealized simulations, as it does in comprehensive simulations of climate change. The wide range of climates allows a systematic test of energetic arguments that have been proposed to account for these changes in the tropical circulation. The analysis shows that a scaling estimate based on changes in the hydrological cycle (precipitation rate and saturation specific humidity) accounts for the simulated changes in the Walker circulation. However, it must be evaluated locally, with local precipitation rates. If global-mean quantities are used, the scaling estimate does not generally account for changes in the Walker circulation, and the extent to which it does is the result of compensating errors in changes in precipitation and saturation specific humidity that enter the scaling estimate.
Quantum weak coin-flipping with bias of 0.192

We present a family of protocols for flipping a coin over a telephone in a quantum mechanical setting. The family contains protocols with n + 2 messages for all n > 1, and asymptotically achieves a bias of 0.192. The case n = 2 is equivalent to the protocol of Spekkens and Rudolph with bias 0.207, which was the best known protocol. The case n = 3 achieves a bias of 0.199, and n = 8 achieves a bias of 0.193. The analysis of the protocols uses Kitaev's description of coin-flipping as a semidefinite program. We construct an analytical solution to the dual problem which provides an upper bound on the amount that a party can cheat.
Pt-catalyzed rearrangement of oxaspirohexanes to 3-methylenetetrahydrofurans: scope and mechanism.

A novel Pt-catalyzed rearrangement of oxaspirohexanes to 3-methylenetetrahydrofurans is reported. Mechanistic studies by 13C-labeling experiments confirm oxidative addition of Pt(II) regioselectively to the least substituted carbon–carbon bond of the cyclopropane to form a platinacyclobutane intermediate. To our knowledge, this is the first alkoxy-substituted platinacyclobutane that has been observed spectroscopically. The scope and a proposed mechanism of this new Pt-catalyzed transformation are described.
Bounds for the Thurston–Bennequin number from Floer homology

Using a knot concordance invariant from the Heegaard Floer theory of Ozsvath and Szabo, we obtain new bounds for the Thurston- Bennequin and rotation numbers of Legendrian knots in S 3 . We also apply these bounds to calculate the knot concordance invariant for certain knots. AMS Classification 57R17, 57M27
Union support recovery in high-dimensional multivariate regression

In the problem of multivariate regression, a K-dimensional response vector is regressed upon a common set of p covariates, with a matrix B* isin RopfptimesK of regression coefficients. We study the behavior of the group Lasso using lscr1/lscr2 regularization for the union support problem, meaning that the set of s rows for which B* is non-zero is recovered exactly. Studying this problem under high-dimensional scaling, we show that group Lasso recovers the exact row pattern with high probability over the random design and noise for scalings of (n, p, s) such that the sample complexity parameter given by thetas(n, p, s) := n/[2psi(B*) log(p - s)] exceeds a critical threshold. Here n is the sample size, p is the ambient dimension of the regression model, s is the number of non-zero rows, and psi(B*) is a sparsity-overlap function that measures a combination of the sparsities and overlaps of the K-regression coefficient vectors that constitute the model. This sparsity-overlap function reveals that, if the design is uncorrelated on the active rows, block lscr1/lscr2 regularization for multivariate regression never harms performance relative to an ordinary Lasso approach, and can yield substantial improvements in sample complexity (up to a factor of K) when the regression vectors are suitably orthogonal. For more general designs, it is possible for the ordinary Lasso to outperform the group Lasso.
A novel approach to the synthesis of enediynes

Abstract A new method for the synthesis of enediynes is described based on stannylcupration of acetylene and certain activated alkynes, in situ reaction with 1-halo-1-alkynes, iododestannylation, and Pd(0)-catalyzed coupling with terminal alkynes.
Distinctive Marketing and Information Technology Capabilities and Strategic Types: A Cross-National Investigation

The authors examine the relationship between strategic type and development of distinctive marketing, market-linking, technology, and information technology (IT) capabilities to implement innovation strategy. They hypothesize that prospectors must build technical and IT capabilities, whereas defenders develop market-linking and marketing capabilities. The authors collect data from 709 firms across the United States, Japan, and China. They find support for their capability hypotheses, as well as for some of their cross-national hypotheses that are based on cultural and business environment differences among the three countries. In particular, they find support for the hypotheses that Japanese firms have greater technology and IT capabilities than U.S. firms of the same strategic type. They conclude with implications for management.
Estimating the Causal Effect of Social Capital: A Review of Recent Research

Although there is a large literature on social capital, empirical estimates of the effect of social capital may be biased because of social homophily, the tendency of similar people to become friends with each other. Despite the methodological difficulties, a recent literature has emerged across several different disciplines that tries to estimate the causal effect of social capital. This paper reviews this recent empirical literature on social capital, paying close attention to the statistical and theoretical assumptions involved. Overall, there is evidence that genuine progress has been made in estimating the effect of social capital. The reviewed articles should provide useful examples for future research.
Low frequency filtering and real business cycles

This paper discusses in detail the Hodrick-Prescott (1980) filter from time and frequency domain perspectives, motivating it as a generalization of the exponential smoothing filter. We show that the HP filter — when applied to large samples — contains a centered fourth difference and hence renders stationary time series that are ‘difference-stationary’ and, indeed, integrated of higher order. However, our application of the HP filter to U.S. time series and to the simulated outcomes of real business cycle models leads us to question its widespread use as a unique method of trend elimination. We provide examples of how HP filtering dramatically alters measures of persistence, variability, and comovement.
DNA methylation impacts gene expression and ensures hypoxic survival of Mycobacterium tuberculosis

DNA methylation regulates gene expression in many organisms. In eukaryotes, DNA methylation is associated with gene repression, while it exerts both activating and repressive effects in the Proteobacteria through largely locus-specific mechanisms. Here, we identify a critical DNA methyltransferase in M. tuberculosis, which we term MamA. MamA creates N6-methyladenine in a six base pair recognition sequence present in approximately 2,000 copies on each strand of the genome. Loss of MamA reduces the expression of a number of genes. Each has a MamA site located at a conserved position relative to the sigma factor −10 binding site and transcriptional start site, suggesting that MamA modulates their expression through a shared, not locus-specific, mechanism. While strains lacking MamA grow normally in vitro, they are attenuated in hypoxic conditions, suggesting that methylation promotes survival in discrete host microenvironments. Interestingly, we demonstrate strikingly different patterns of DNA methyltransferase activity in different lineages of M. tuberculosis, which have been associated with preferences for distinct host environments and different disease courses in humans. Thus, MamA is the major functional adenine methyltransferase in M. tuberculosis strains of the Euro-American lineage while strains of the Beijing lineage harbor a point mutation that largely inactivates MamA but possess a second functional DNA methyltransferase. Our results indicate that MamA influences gene expression in M. tuberculosis and plays an important but strain-specific role in fitness during hypoxia.
Combinatorial neural codes from a mathematical coding theory perspective

Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes RF codes. We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli.
High-Yielding Oxidation of β-Hydroxyketones to β-Diketones Using o-Iodoxybenzoic Acid

The oxidation of β-hydroxyketones to β-diketones was systematically investigated. o-Iodoxybenzoic acid (IBX) was found to be efficient, operationally easy, and superior to other common oxidants. The reaction is suitable for milligram- to gram-scale oxidations.
Hydrolysis of 2,4‐dinitrophenyl phosphate catalyzed by single‐chain, twin‐tailed and bolaform surfactants

The spontaneous hydrolysis of 2,4-dinitrophenyl phosphate dianion (2,4-DNPP) is speeded by cationic micelles of cetyltrimethylammonium salts [CTAX, X = Cl, Br, (SO4)0.5] and of bolaform(22)X2 [Me3N+ (CH2)nN+ Me3 2X−, n = 22, X = Br, (SO4)0.5]. The shorter-chain bolaform surfactants (n = 16, 12, X = Br) are less effective. Twin-chain surfactants of didodecyl and dicetyldimethylammonium salts (C12H25)2NMe2X, X = Br, Cl, (SO4)0.5 and (C16H33)2NMe2X, X = Cl, (SO4)0.5 and pyridinium-ion surfactants C16H33NC5H5Cl and its 4-(dimethylamino) derivative, also speed hydrolysis. The first-order rate constants increase to limiting values (k′M) when substrate is fully bound and these values are not very sensitive to the nature of the surfactant and are generally greater than in water by factors of 20–110. However, the extent of binding of 2,4-DNPP is sensitive to the nature of the surfactant. Tertiary amines, e.g., pyridine and DABCO speed the reaction in CTACl by generating an intermediate phosphoramidate.
Appropriate lengths between phalanges of multijointed fingers for stable grasping

An appropriate arrangement of finger joints is very important since the stability of grasping an object greatly depends on that arrangement. Multijointed fingers can grasp an object with many points of contact each of which is pressed against the object as if wrapping up that object. The amount of the wrapped up area and the form of the finger when an object is grasped are therefore important factors for determining the stability of grasping. We propose the wrapping factor to be used for the evaluation of the stability of grasping by using these factors. We consider 28 models for the finger having three joints, and perform a simulation of their ability to grasp various shapes stably. Based on the simulation results, an appropriate arrangement of lengths between phalanges for a multijointed finger is presented.
Development Of A Real Time Monitor For Superconductive Thin Film Preparation

In 1986, Bendorz and Muller1 discovered that metallic oxide with a perovskite structure in the La-Ba-Cu-O system exhibited superconductivity at 20°K. In early 1987, Chu and his co-workers2 made a YBa2Cu3O7-x compound which had a Tc higher than the temperature of liquid nitrogen. Since these discoveries, the research and development of high-Tc superconductors has aroused unpecedented attention, not only from the scientific community, but also from various industries and governments. As these new superconducting materials are in general very "brittle" and difficult to machine, it is extremely difficult to fabricate them into thin wires. In addition, practical use of new high-Tc superconductors will require materials with very high critical current density. Thus thin film preparation is particularly important for many applications of superconductors, such as electronics for the computer industry. Films with high superconducting transition temperatures have been prepared by electron beam evaporation, organometallic chemical vapor deposition, DC sputtering, molecular beam epitaxy, and laser evaporation and deposition processes. For example, Rice et al.3 used electron beam and thermal evaporation to produce Ca-Sr-Bi-Cu-O superconducting films from CaF2, SrF2, Bi, and Cu targets. Berry et al.' produced a superconductive film by organometallic chemical vapor deposition. Hellman et al.5 used molecular beam epitaxy to produce a DyBa2Cu307, film on a SrTiO3 substrate. Lynds et al.6 used a Nd-YAG laser beam to do laser evaporation and deposition to prepare a YBa2Cu307-x thin film from targets of Y203, Bat CO3, and CuO. Kwok et al.7 applied a homogeneous excimer laser to obtain a film with the right stoichiometry of YBa2Cu307,. However, most of the films in the works cited above need to be annealed in an oxygen environment in order to produce superconductivity. Recently, several research groups obtained superconductive films of YBa2Cu307, by raising the temperature of the substrate and introducing oxygen into the chamber during the thin film preparation process.8 However, no superconductive films of the Bi-Sr-Ca-Cu-O or Tl-Sr-Ba-Cu-0 systems were obtained without oxygen annealing. Nevertheless, the right ratio of various metal elements is one of the key factors in achieving superconductivity. Superconductive films are usually obtained based on repeated trials and adjustments. Venkatesan et al.9 observed two distinct components during pulsed laser deposition of high-T, superconductive film. It was pointed out that the quality of the superconductive film depends on controlling the film stoichiometry. The role of introducing oxygen into the thin film preparation chamber has never been fully understood. Thus, the need for a real-time monitor for high-Tc thin film preparation is quite critical.
Minimum Heat Input Optimal Skip Entry into Venus Atmosphere

We present the optimal skip entry into Venus atmosphere of a space vehicle with minimum total heat input. The motion of the lifting body vehicle follows a plane e ight path, and the variation of the Venus density with altitude has an exponential law. The variational problem is a Lagrange problem, which becomes a bilocal problem and can be solved numerically with the transition matrix method. The numerical applications have practical interest for the vehicle’ s evolutions into Venus atmosphere.
Commentaries and Rejoinder to “Marketing of Vice Goods: A Strategic Analysis of the Package Size Decision” by Sanjay Jain

Jain [Jain, S. 2012. Marketing of vice goods: A strategic analysis of the package size decision. Marketing Sci.31(1) 36--51] examines the impact of consumers' self-control problem on the equilibrium package sizes offered by firms marketing vice goods. This series of discussions offers commentaries and a rejoinder that discuss competitive implications of firms offering small sizes and the impact of smaller sizes on the total consumer expenditure.
Construction of Risk-Averse Enhanced Index Funds

We propose a partial replication strategy to construct risk-averse enhanced index funds. Our model takes into account the parameter estimation risk by defining the asset returns and the return covariance terms as random variables. The variance of the index fund return is required to be below a low-risk threshold with a large probability, thereby limiting the market risk exposure of the investors. The resulting stochastic integer problem is reformulated through the derivation of a deterministic equivalent for the risk constraint and the use of a block decomposition technique. We develop an exact outer approximation method based on the relaxation of some binary restrictions and the reformulation of the cardinality constraint. The method provides a hierarchical organization of the computations with expanding sets of integer-restricted variables and outperforms the Bonmin and the CPLEX solvers. The method can solve large instances up to 1,000 securities, converges fast, scales well, and is general enough to be applicable to problems with buy-in-threshold constraints.
Carboxylic acid reductions : insights from mixed anhydrides and thiol esters

Abstract Reduction of thiol esters and mixed anhydrides with lithium has been accomplished. Thiol esters have been found to react exclusively to yield aldehydes. Mixed anhydrides give cleavage in a way that can be rationalized by stability of the incipient anions.
Banks as patient fixed-income investors

We examine the business model of traditional commercial banks in the context of their coexistence with shadow banks. While both types of intermediaries create safe “money-like” claims, they go about this in different ways. Traditional banks create safe claims by relying on deposit insurance, supported by costly equity capital. This structure allows bank depositors to remain “sleepy”: they do not have to pay attention to transient fluctuations in the mark-to-market value of bank assets. In contrast, shadow banks create safe claims by giving their investors an early exit option that allows them to seize collateral and liquidate it at the first sign of trouble. Thus traditional banks have a stable source of funding, while shadow banks are subject to runs and fire-sale losses. These different funding models in turn influence the kinds of assets that traditional banks and shadow banks hold in equilibrium: traditional banks have a comparative advantage at holding fixed-income assets that have only modest fundamental risk, but are relatively illiquid and have substantial transitory price volatility.
Short rational generating functions for lattice point problems

Abstract. We prove that for any ﬁxed d the generating function of the projectionof the set of integer points in a rational d-dimensional polytope can be computed inpolynomial time. As a corollary, we deduce that various interesting sets of latticepoints, notably integer semigroups and (minimal) Hilbert bases of rational cones,have short rational generating functions provided certain parameters (the dimensionand the number of generators) are ﬁxed. It follows then that many computationalproblems for such sets (for example, ﬁnding the number of positive integers notrepresentable as a non-negative integer combination of given coprime positive integersa 1 ,... ,a d ) admit polynomial time algorithms. We also discuss a related problem ofcomputing the Hilbert series of a ring generated by monomials. 1. Introduction and Main ResultsOur main motivation is the following question which goes back to Frobenius andSylvester.(1.1) The Frobenius Problem. Let a 1 ,... ,a d be positive coprime integers andletS =nµ
Independent transversals in locally sparse graphs

Let G be a graph with maximum degree @D whose vertex set is partitioned into parts V(G)=V"[email protected][email protected]?V"r. A transversal is a subset of V(G) containing exactly one vertex from each part V"i. If it is also an independent set, then we call it an independent transversal. The local degree of G is the maximum number of neighbors of a vertex v in a part V"i, taken over all choices of V"i and [email protected]?V"i. We prove that for every fixed @e>0, if all part sizes |V"i|>=([email protected])@D and the local degree of G is o(@D), then G has an independent transversal for sufficiently large @D. This extends several previous results and settles (in a stronger form) a conjecture of Aharoni and Holzman. We then generalize this result to transversals that induce no cliques of size s. (Note that independent transversals correspond to s=2.) In that context, we prove that parts of size |V"i|>=([email protected])@Ds-1 and local degree o(@D) guarantee the existence of such a transversal, and we provide a construction that shows this is asymptotically tight.
COMET C/2004 Q2 (MACHHOLZ): PARENT VOLATILES, A SEARCH FOR DEUTERATED METHANE, AND CONSTRAINT ON THE CH4 SPIN TEMPERATURE

High-dispersion (λ/δλ ≈ 25,000) infrared spectra of Comet C/2004 Q2 (Machholz) were acquired on 2004 November 28-29, and 2005 January 19 (UT dates) with the Near InfraRed echelle SPECtrograph (NIRSPEC) at the Keck-2 telescope on Mauna Kea. We detected H_(2)O, CH_4, C_2H_2, C_2H_6, CO, H_2CO, CH_(3)OH, HCN, and NH_3 and we conducted a sensitive search for CH_3D. We report rotational temperatures, production rates, and mixing ratios (with respect to H_(2)O) at heliocentric distances of 1.49 AU (2004 November) and 1.21 AU (2005 January). We highlight three principal results. (1) The mixing ratios of parent volatiles measured at 1.49 AU and 1.21 AU agree within confidence limits, consistent with homogeneous composition in the mean volatile release from the nucleus of C/2004 Q2. Notably, the relative abundance of C_2H_6/C_2H_2 is substantially higher than those measured in other comets, while the mixing ratios C_2H_6/H_(2)O, CH_(3)OH/H_(2)O, and HCN/H_(2)O are similar to those observed in comets, referred to as "organics-normal". (2) The spin temperature of CH_4 is >35-38 K, an estimate consistent with the more robust spin temperature found for H_(2)O. (3) We obtained a 3σ upper limit of CH_3D/CH_4 < 0.020 (D/H < 0.005). This limit suggests that methane released from the nucleus of C/2004 Q2 is not dominated by a component formed in extremely cold (near 10 K) environments. Formation pathways of both interstellar and nebular origin consistent with the measured D/H in methane are discussed. Evaluating the relative contributions of these pathways requires further modeling of chemistry including both gas-phase and gas-grain processes in the natal interstellar cloud and in the protoplanetary disk.
A set of transistor circuits for asynchronous, direct-coupled computers

Extensive operating experience with the ORDVAC and the ILLIAC has demonstrated to members of the University of Illinois Computer Laboratory the advantages of computers which are direct-coupled and operate asynchronously. This paper describes a set of building block circuits, which is the first result of a program to develop transistor circuits which would be suitable for an asynchronous machine.
Abortion Legalization and Adolescent Substance Use

Abstract We assess whether adolescents who faced a higher risk of having been aborted are more likely to use controlled substances. We find that adolescents born in states that legalized abortion before national legalization in 1973, during the years when only those states permitted abortion, were much less likely to use drugs than persons from the same birth cohorts born elsewhere. These differences do not exist for earlier or later cohorts. Our results are much the same when we characterize abortion risk by either the birth rate or abortion rate in the year and place of the person’s birth.
A dynamic load-balancing policy with a central job dispatcher (LBC)

A dynamic load-balancing policy is proposed with a central job dispatcher called the LBC policy for distributed systems. The design of this policy is motivated by the operation of a single-queue multiserver queueing system, and the average job response time is the same as that of a single-queue multiserver system, which is the best achievable performance when the communication delay is reduced to zero. Hence, near-minimum average job response time is expected for distributed systems with high-speed communication subnets. The performance is studied for systems with nonnegligible job transfer delays in the following three aspects: average job response time, overhead due to information exchanges, and sensitivity to heterogeneous load. >
Polarity‐Directed One‐Pot Asymmetric Cascade Reactions Mediated by Two Catalysts in an Aqueous Buffer

Modern organic synthesis predominately relies on functional group reactivity differences to achieve the chemoselective formation of desired products. Herein we report a one-pot multistep asymmetric catalytic reaction in which substrates with similar chemical reactivities are differentiated on the basis of polarity. The one-pot reaction involves two catalysts and three substrates in the presence of water. The reaction mixture consists of two phases: a polar aqueous phase and a hydrophobic organic phase. The biphasic nature of the reaction medium and the polarity properties of the substrates and catalysts enable the selective formation of a major product instead of a statistical mixture of four possible products. We chose a two-step reaction involving condensation and subsequent conjugate addition as a model to develop a polarity-directed cascade reaction. Both reaction steps can involve linear aliphatic aldehydes as substrates (Scheme 1). Our aim was to combine the two reaction
Binary representation in gene expression programming: towards a better scalability

One of the main problems that arises when using gene expression programming (GEP) conditions in learning classifier systems is the increasing number of symbols present as the problem size grows. When doing model-building LCS, this issue limits the scalability of such a technique, due to the cost required. This paper proposes a binary representation of GEP chromosomes to paliate the computation requirements needed. A theoretical reasoning behind the proposed representation is provided, along with empirical validation.
Actinides, the narrowest bands

A table of elements is shown that demonstrates the crossover from superconductivity to magnetism as well as regions of mixed valence. In particular, the actinides must eventually show 4f-electron like mixed valence, after the 5f-electrons become localized. There also seems to be an adiabatic continuation between heavy fermion and mixed valence behavior.
Reputations, Market Structure, and the Choice of Quality Assurance Systems in the Food Industry

Many food traits desired by consumers are costly to provide and difficult to verify. A complicating factor is that delivered quality can only be affected stochastically by producers and imperfectly observed by consumers. Markets for these goods will emerge only if supplying firms can be trusted. We develop a repeated purchases model to explore how quality discoverability, market structure, nature of reputations, market premiums, and discount factors drive firm choice about the stringency of quality assurance systems designed to gain consumer trust. Reputation protection is key incentive for firms to invest in high-quality goods and quality assurance systems.
Defining an abnormal first stage of labor based on maternal and neonatal outcomes.

Objective The objective of the study was to determine the threshold for defining abnormal labor that is associated with adverse maternal and neonatal outcomes. Study Design This study consisted of a retrospective cohort of all consecutive women admitted at a gestation of 37.0 weeks or longer from 2004 to 2008 who reached the second stage of labor. The 90th, 95th, and 97th percentiles for progress in the first stage of labor were determined specific for parity and labor onset. Women with a first stage above and below each centile were compared. Maternal outcomes were cesarean delivery in the second stage, operative delivery, prolonged second stage, postpartum hemorrhage, and maternal fever. Neonatal outcomes were a composite of the following: admission to level 2 or 3 nursery, 5 minute Apgar less than 3, shoulder dystocia, arterial cord pH of less than 7.0, and a cord base excess of –12 or less. Results Of the 5030 women, 4534 experienced first stage of less than the 90th percentile, 251 between the 90th and 94th percentiles, 102 between the 95th and 96th percentiles, and 143 at the 97th percentile or greater. Longer labors were associated with an increased risk of a prolonged second stage, maternal fever, the composite neonatal outcome, shoulder dystocia, and admission to a level 2 or 3 nursery ( P Conclusion Although women who experience labor dystocia may ultimately deliver vaginally, a longer first stage of labor is associated with adverse maternal and neonatal outcomes, in particular shoulder dystocia. This risk must be balanced against the risks of cesarean delivery for labor arrest.
Power Saving Strategies and Technologies in Network Equipment Opportunities and Challenges, Risk and Rewards

Drawing from todaypsilas best-in-class solutions, we identify power-saving strategies that have succeeded in the past and look forward to new ideas and paradigms. We strongly believe that designing energy-efficient network equipment can be compared to building sports cars - task-oriented, focused and fast. However, unlike track-bound sports cars, ultra-fast and purpose-built silicon yields better energy efficiency when compared to more generic "family sedan" designs that mitigate go-to-market risks by being the masters of many tasks. Thus, we demonstrate that the best opportunities for power savings come via protocol simplification, best-of-breed technology, and silicon and software optimization, to achieve the least amount of processing necessary to move packets. We also look to the future of networking from a new angle, where energy efficiency and environmental concerns are viewed as fundamental design criteria and forces that need to be harnessed to continually create more powerful networking equipment.
Synthesis of a contiguous tricyclic purine system : entry to unique nucleosides

Abstract A unique class of hypermodified purine nucleosides, where the carbohydrate moiety is fused to the imidazole ring, has been designed and synthesized regiospecifically and stereospecifically using a multi-step approach and stereochemically defined carbohydrate precursors.
ASTER observations for the monitoring of land surface fluxes

This paper presents a review of how data from the Advanced Spaceborne Thermal Emission radiometer (ASTER) can be used to estimate the energy fluxes from the land surface. The basic concepts of the energy balance at the land surface are presented along with an example of how remotely sensed surface brightness temperatures can be used to estimate the sensible heat. The example is from the Monsoon 90 experiment conducted over an arid watershed in the state of Arizona in the United States.