cssi/SciSciGPT-SciSciNet huggingface dataset:
Video self-modeling: A job skills intervention with individuals with intellectual disabilities in employment settings.

The purpose of this study was to explore the effectiveness of video self-modeling (VSM) to teach chained job tasks to individuals with intellectual disability in community-based employment settings. Initial empirical evaluations have demonstrated that VSM when used in combination with other instructional strategies, are effective methods to teach chained tasks to individuals with intellectual disability. However, no study has investigated the effectiveness of VSM as a stand-alone intervention to teach chained tasks. In this study, the effectiveness of VSM alone to teach chained job tasks was first evaluated before the addition of other instructional strategies (i.e., instructor feedback and practice) to the VSM intervention package. Three adults with intellectual disability participated in this study. A within participant multiple probe design across targeted job tasks, replicated across the three participants, was used to evaluate the effectiveness of VSM in this study. All of the participants demonstrated increased task acquisition with the VSM intervention; however, the effectiveness of VSM alone, or in combination with feedback and practice, varied across participants and job tasks. Limitations of the study and implications for future research are discussed.
Synthesis of aryl ketones by the PD-catalyzed C-H activation of arenes and intermolecular carbopalladation of nitriles.

The palladium-catalyzed reaction of simple arenes and nitriles provides good to excellent yields of aryl ketones or the corresponding hindered imines. The addition of a small amount of DMSO increases the yields dramatically. Both intermolecular and intramolecular examples of this process are successful. This novel chemistry is believed to involve palladium-catalyzed C−H activation, followed by carbopalladation of the nitrile.
Stereoscopic Motion Tracking System

A Stereoscopic Motion Tracking System is being developed for use with a video game system for rehabilitation of children affected by Cerebral Palsy. Two cameras will be used to track the (x, y) location of a motion, using stereoscopic principles this data will be used to calculate the Z location of the motion. This data will be collected for the duration of a game. Tracking the motion of a child playing the video game will allow to easily quantify motor control improvement over time.
Conjugacy and dynamics in Thompson’s groups

We give a unified solution to the conjugacy problem for Thompson’s groups $$F, \,T$$ , and $$V$$ . The solution uses “strand diagrams”, which are similar in spirit to braids and generalize tree-pair diagrams for elements of Thompson’s groups. Strand diagrams are closely related to piecewise-linear functions for elements of Thompson’s groups, and we use this correspondence to investigate the dynamics of elements of $$F$$ . Though many of the results in this paper are known, our approach is new, and it yields elegant proofs of several old results.
Parallel Programming Environment: A Key to Translating Tera-Scale Platforms into a Big Success

Summary form only given. Moore's Law will continue to increase the number of transistors on die for a couple of decades, as silicon technology moves from 65nm today to 45nm, 32 nm and 22nm in the future. Since the power and thermal constraints increase with frequency, multi-core or many-core will be the way of the future microprocessor. In the near future, HW platforms will have many-cores (>16 cores) on die to achieve >1 TIPs computation power, which will communicate each other through an on-die interconnect fabric with >1 TB/s on-die bandwidth and <30 cycles latency. Off-die D-cache will employ 3D stacked memory technology to tremendously increase off-die cache/memory bandwidth and reduce the latency. Fast copper flex cables will link CPU-DRAM on socket and the optical silicon photonics will provide up to 1 Tb/s I/O bandwidth between boxes. The HW system with TIPs of compute power operating in Tera-bytes of data make this a "Tera-scale" platform. What are the SW implications with the HW changes from uniprocessor to Tera-scale platform with many-cores as "the way of the future?" It will be great challenge for programming environments to help programmers to develop concurrent code for most client software. A good concurrent programming environment should extend the existing programming languages that typical programmers are familiar with, and bring benefits for concurrent programming. There are lots of research topics. Examples of these topics include flexible parallel programming models based on needs from applications, better synchronization mechanisms like Transactional Memory to replace simple "Thread + Lock" structure, nested data parallel language primitives with new protocols, fine-grained synchronization mechanisms with HW support, maybe fine-grained message passing, advanced compiler optimizations for the threaded code, and SW tools in the concurrent programming environment. A more interesting problem is how to use such a many-core system to improve single-threaded performance
MAINBANKS AND INVESTMENT EFFICIENCY IN FINANCIAL DISTRESS

We explore the effects of mainbanks on investment efficiency financial distress. The previous literature argues that firms with close financial relationships with banks have lower costs of financial distress because of reduced underinvestment problem. Although benefits may accrue to such close relationships, we contend shortcomings are possible as well. A firm in financial distress without a mainbank may be forced to reduce investment or sell assets to a buyer who has a higher value. However, for a firm with a mainbank, this disciplinary force is weakened. To firms with poor investment opportunities the presence of mainbanks may actually induce an overinvestment problem. The empirical findings reported here are consistent with this idea.
Analysis of Volumetric Absorption of Solar Energy and Its Interaction With Convection

Determination de l'efficacite de l'absorption d'une chambre et de la temperature de sortie atteinte par le fluide de travail pour differents parametres optiques, ecoulements, proprietes de la surface rayonnante et convergences du faisceau par simulation numerique. Comparaison des resultats du modele a 2 dimensions etabli ici avec ceux du modele unidimensionnel
Copper‐Catalyzed Coupling of Triaryl‐ and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations

An efficient copper(I)-catalyzed coupling of triaryl and trialkylindium reagents with aryl iodides and bromides is reported. The reaction proceeds at low catalyst loadings (2 mol %) and generally only requires 0.33 equivalents of the triorganoindium reagent with respect to the aryl halide as all three organic nucleophilic moieties of the reagent are transferred to the products through consecutive transmetalations. The reaction tolerates a variety of functional groups and sterically hindered substrates. Furthermore, preliminary mechanistic studies that entailed the synthesis and characterization of potential reaction intermediates offered a glimpse of the elementary steps that constitute the catalytic cycle.
Kernel Estimation of Partial Means and a General Variance Estimator

Econometric applications of kernel estimators are proliferating, suggesting the need for convenient variance estimates and conditions for asymptotic normality. This paper develops a general “delta-method” variance estimator for functionals of kernel estimators. Also, regularity conditions for asymptotic normality are given, along with a guide to verify them for particular estimators. The general results are applied to partial means, which are averages of kernel estimators over some of their arguments with other arguments held fixed. Partial means have econometric applications, such as consumer surplus estimation, and are useful for estimation of additive nonparametric models.
Irregular Satellites of the Planets: Products of Capture in the Early Solar System

All four giant planets in the Solar system possess irregular satellites, characterized by large, highly eccentric and/or inclined orbits that are distinct from the nearly circular, uninclined orbits of the regular satellites. This difference can be traced directly to different modes of formation. Whereas the regular satellites grew by accretion within circumplanetary disks the irregular satellites were captured from initially heliocentric orbits at an early epoch. Recently, powerful survey observations have greatly increased the number of known irregular satellites, permitting a fresh look at the group properties of these objects and motivating a re-examination of the mechanisms of capture. None of the suggested mechanisms, including gas-drag, pull-down, and three-body capture, convincingly fit the group characteristics of the irregular satellites. The sources of the satellites also remain unidentified.
Probing the Ionization State of the Universe at z > 6*

We present high signal-to-noise ratio Keck ESI spectra of the two quasars known to have Gunn-Peterson absorption troughs, SDSS J1030+0524 (z = 6.28) and SDSS J1148+5251 (z = 6.37). The Lyα and Lyβ troughs for SDSS J1030+0524 are very black and show no evidence of any emission over a redshift interval of ~0.2, starting at z = 6. On the other hand, SDSS J1148+5251 shows a number of emission peaks in the Lyβ Gunn-Peterson trough along with a single weak peak in the Lyα trough. The Lyα emission has corresponding Lyβ emission, suggesting that it is indeed a region of lower optical depth in the intergalactic medium at z = 6.08. The stronger Lyβ peaks in the spectrum of SDSS J1148+5251 could also conceivably be the result of "leaks" in the intergalactic medium (IGM), but we suggest instead that they are Lyα emission from an intervening galaxy at z = 4.9. This hypothesis gains credence from a strong complex of C IV absorption at the same redshift and from the detection of continuum emission in the Lyα trough at the expected brightness. If this proposal is correct, the quasar light has probably been magnified through gravitational lensing by the intervening galaxy. The Stromgren sphere observed in the absorption spectrum of SDSS J1148+5251 is significantly smaller than expected on the basis of its brightness, which is consistent with the hypothesis that the quasar is lensed. If our argument for lensing is correct, the optical depths derived from the troughs of SDSS J1148+5251 are only lower limits [albeit still quite strong, with τ(Lyα) > 16 inferred from the Lyβ trough]. The Lyβ absorption trough of SDSS J1030+0524 gives the single best measurement of the IGM transmission at z > 6, with an inferred optical depth of τ(Lyα) > 22.
Optimal Unemployment Insurance in Labor Market Equilibrium when Workers can Self-Insure

I develop an equilibrium matching model in which workers have preferences over consumption and hours of work and are able to self-insure against unemployment risks by accumulating precautionary wealth. Wages and working hours are the outcomes of Nash bargaining between workers and firms. I focus on an unemployment insurance (UI) system with constant benefits of indefinite duration financed through a constant labor income tax. Low-wealth individuals work unusually long hours to quickly accumulate precautionary wealth. The Frisch elasticity of labor supply governs a worker’s utility cost of supplying labor and hence the cost of accumulating precautionary wealth. A lower elasticity implies a higher utility cost of adjusting hours. I take Frisch elasticities from recent research using household data and find that the optimal level of UI benefits is between 34 and 40 percent of average compensation. The potential welfare gains from moving from current 34 percent to the optimal policy are as large as 0.13 percent of lifetime consumption. The optimal replacement rate is decreasing in the Frisch elasticity of labor supply.
Mechanisms for Requirements Driven Component Selection and Design Automation

Component selection and design automation play a major role in reducing the system development cost and time due to the ability to accommodate rapid changes in technology advances and the time-to-market constraints imposed on product release. In this article we present our research on partially automating the process of architecture design starting from semantic representations for requirements and components. The Systems Modeling Language (SysML) is used for specification and modeling. A set of rules written in Prolog control the processes for model verification and architecture synthesis. This methodology is part of the Requirements-Driven Design Automation (RDDA) framework that we develop for component-based system development.
Empirical Studies of Programming Knowledge

We suggest that expert programmers have and use two types of programming knowledge: 1) programming plans, which are generic program fragments that represent stereotypic action sequences in programming, and 2) rules of programming discourse, which capture the conventions in programming and govern the composition of the plans into programs. We report here on two empirical studies that attempt to evaluate the above hypothesis. Results from these studies do in fact support our claim.
Synthesis of complex ethynyladenosines using organic triflic enolates in palladium-catalyzed reactions: Potential agonists for the adenosine A2 receptor

Abstract Many high affinity adenosine A 2 receptor agonists contain substituents at position 2 of the purine base. In the search for new methodology to develop C-2 substituted adenosine analogues, we have applied organic triflates in palladium-catalyzed cross-couplings that resulted in new 2-cycloalkylated ethynyladenosines. The organic triflates are derived from commercially available ketones and, when used in the cross-couplings, result generally in clean reactions with good yields. These are the first examples of the utilization of organic triflates in palladium-catalyzed cross-coupling reactions in the synthesis of modified nucleosides.
Variational Methods, Multisymplectic Geometry and Continuum Mechanics

This paper presents a variational and multisymplectic formulation of both compressible and incompressible models of continuum mechanics on general Riemannian manifolds. A general formalism is developed for non-relativistic first-order multisymplectic field theories with constraints, such as the incompressibility constraint. The results obtained in this paper set the stage for multisymplectic reduction and for the further development of Veselov-type multisymplectic discretizations and numerical algorithms. The latter will be the subject of a companion paper.
Asymmetric synthesis of alkaloids using polyfunctionalized chiral building blocks

Enantiopure N-sulfinyl-δ-amino-β-ketoesters and isoquinolones, prepared from sulfinimines (N-sulfinyl imines) are a new class of polyfunctionalized chiral building blocks. These building blocks provide easy access to enantiomerically pure, functionalized piperidines and tetrahydroisoquinolines with a minimum of chemical manipulation and protecting-group chemistry. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:486–492, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10090
Power Politics and the Free Trade Bandwagon

What explains the world's newfound enthusiasm for free trade? Are government leaders integrating their economies to achieve Pareto-improving gains? Or is it because a critical mass of pro—free trade governments has acquired the capacity to “go it alone,” leaving would-be protectionists with a choice between a bad option (opening their markets at very high political cost) and an even worse alternative (incurring the still higher political costs of exclusion)? This article suggests that in practice, mutual-gains-seeking motivations are frequently dominated by defensive ones. The North American Free Trade Agreement is a case in point: Without in any way being bullied or coerced, the Mexican and Canadian governments agreed to take part in a multilateral arrangement that the evidence suggests neither much liked. Although hard to reconcile with the political economy literature's positive-sum model of international cooperation, this finding is consistent with the broader “power-politics” model introduced here.
High-speed arithmetic coder/decoder architectures

The design of fast decoders using a novel interval tree search method is presented. The decoder can be modeled as a FSM (finite state machine), enabling the application of the look-ahead technique to achieve higher speeds. The look-ahead approach leads to slight degradation in performance, in terms of the adder/subtractor delay in the coder/decoder due to increased word lengths. The performance of the decoder is improved by using redundant arithmetic. The tree search method combined with redundant arithmetic and look-ahead leads to desired speedups without any degradation in performance. >
Norm estimates of complex symmetric operators applied to quantum systems

This paper communicates recent results in the theory of complex symmetric operators and shows, through two non-trivial examples, their potential usefulness in the study of Schrodinger operators. In particular, we propose a formula for computing the norm of a compact complex symmetric operator. This observation is applied to two concrete problems related to quantum mechanical systems. First, we give sharp estimates on the exponential decay of the resolvent and the single-particle density matrix for Schrodinger operators with spectral gaps. Second, we provide new ways of evaluating the resolvent norm for Schrodinger operators appearing in the complex scaling theory of resonances.
Formation of Grain‐Boundary Carbon‐Containing Phase During Annealing of YBa2Cu3O6+x

This paper presents in situ annealing studies of YBa{sub 2}Cu{sub 3}O{sub 6 + x} performed in an optical hot stage which revealed that, at temperatures {gt} 450{degrees}C, localized melting occurred. On subsequent cooling, a discrete second phase was observed at the YBa{sub 2}Cu{sub 3}O{sub 6 + x} grain boundaries. Quantitative chemical analysis using x-ray wavelength dispersive spectroscopy indicated that the second phase was composed of a barium oxycarbonate. The source of the carbon in the second phase was identified to be CO{sub 2} in the atmosphere.
Firm location and the determinants of exporting in developing countries

Using a cross-section of more than 40,000 manufacturing and services firms in 79 developing countries from the World Bank's Enterprise Surveys Database, this paper assesses how firm location determines the likelihood and extent of exporting in developing countries. Descriptive statistics confirm higher export participation (but not intensity) for firms in core versus non-core regions, despite the finding that firms in the core assess many aspects of the investment climate more negatively. Results from a probit model show that, in addition to firm-specific characteristics, both regional investment climate and agglomeration factors have a significant impact on export participation. Specifically, customs clearance and electricity quality matter for export participation for manufacturing firms. Although localization economies and export spillovers are associated with increased exporting, the opposite is found for urbanization economies for both manufacturing and services firms. The analysis finds that firm-level determinants of exporting matter more for firms located in non-core regions, while regional determinants and agglomeration economies play a larger role in core regions. The findings point to the presence of congestion costs in the core, and suggest that policy interventions to target export participation are likely to have a greater impact if they are focused on core regions over non-core regions, where firm-specific factors predominate. Moreover, the importance of export spillovers and localization economies highlights the potential value of efforts to remove barriers to natural agglomeration both in core and non-core regions, for example through investments in infrastructure, the provision of social services, and regional integration arrangements.
Privacy Policy Representation in Web-based Healthcare

The Health Insurance Portability and Accountability Act of 1996 (HIPAA) has resulted in the presence of very descriptive privacy policies on healthcare Web sites. These policies are intended to notify users about the organization's privacy practices. However, these policies are typically not easy to read, and as a result, few people actually read them. Given the fact that these policies are not optional, but required by HIPAA, they should be presented in a more usable manner that encourages consumers to read them. This, in turn, could encourage users to feel more comfortable when interacting with online healthcare organizations. In this paper, we present the preliminary results of our study that compares various ways to present privacy management information to online healthcare consumers. The study involved a survey of 993 Internet users. We also provide recommendations to managers and Web site designers who focus on usability
Experimental observation of superluminal group velocities in bulk two-dimensional photonic bandgap crystals

The authors have experimentally observed superluminal, negative, and infinite group velocities in bulk hexagonal two-dimensional photonic bandgap crystals with bandgaps in the microwave region. The group velocities depend on the polarization of the incident radiation and the air-filling fraction of the crystal.
Broken Unitarity of the SM

It is shown that because of axial-vector coupling and vector coupling between boson and fermions of different masses, the boson field has four independent components. The spin-0 component has problem of negative probability. The unitarity of the theory is broken. These results are applied to the SM. The masses are mϕ0 = 3.78×1014GeV and mϕ± = 9.31×1013GeV respectively. The unitarity of the SM is broken at about ~ 1014GeV. The masses of W and Z can be generated by two types of interactions mentioned above without Higgs mechanism. The masses of the W and the Z bosons are obtained to be $m^2_W = \frac{1}{2} g^2 m^2_t$ and $m^2_Z = \rho m^2_W/\cos^2 \theta_W$ with ρ≃1. $G_F = \frac{1}{2 \sqrt{2} m^2_t}$.
Reduced-Order Models for Nonlinear Unsteady Aerodynamics

Two reduced-order modeling approaches for the evaluation of nonlinear aerodynamic forces based on CFD computations are presented. These reducedorder models (ROMs) provide a means for rapid calculation of frequency-domain generalized aerodynamic forces, which can be used in traditional flutter analysis scheme, to calculate flutter characteristics about nonlinear steady flows. Two ROMs are presented, one that is based on the Volterra theory for nonlinear systems, and a new ROM that is based on step (indicial) responses. ROM kernels are identified directly from input-output relations, and the study focuses on issues of kernel identification and their effect on the quality of the ROM. First- and second-order ROMs are generated for the response of the AGARD 445.6 wing to forced-harmon ic excitation of its elastic modes. Responses computed from the ROMs are compared to responses obtained directly from a CFD analysis in which the boundary conditions are excited harmonically. Results show that the quality of the Volterra ROM is very sensitive to the amplitudes of the impulse inputs used for identification. The step-response ROM is shown to be more accurate than the Volterra ROM and less sensitive to the amplitude used for its identification.
Modification of epileptiform bursting using chaos control

Recently, attempts have been made to apply chaos control techniques to manipulate the electrical discharges in the brain (interictal bursts) that are characteristic of epilepsy. These techniques would offer the advantage of using small and relatively infrequent stimuli to revert a seizure. However, questions have since arisen as to whether these results were truly chaos control or simply demand pacing. We have previously demonstrated evidence-including unstable periodic orbit (UPO) detection-that such epileptiform bursting is chaotic. We have investigated the potential for chaos control algorithms to manipulate extracellular bursts in rat hippocampal slices exposed to high levels of potassium. Interburst intervals (IBIs) were measured in real time using a threshold-detection circuit, embedded into two-dimensional state space, and analyzed for the presence of UPOs. The detection of a period-1 UPO strongly suggested the presence of chaos in the data and is a prerequisite for most forms of chaos control. Evaluation of control was aided by distinguishing whether IBIs were stimulated or natural. We investigated the effect of control region size on control efficacy. Complications to obtaining control exist, including (1) intrinsic system noise, (2) large instabilities (Lyapunov exponent) of the UFO, (3) difficulties estimating stable manifolds, (4) nonstationarity, and (5) neuronal plasticity. We have examined methods for surmounting these obstacles, including blocking synaptic plasticity and dynamically tracking the fixed point location.
The Production of Safe Food According to Firm Size and Regulatory Exemption: Application to FSMA

One feature of recent food regulations is that they treat small and large farms/firms differently. In this article, the relationship between firm output and food safety depends on firm-specific efficiency factors and how output and food safety interact in the cost function. The model shows that conditional on the distribution of firm output and food safety, new food safety regulations may increase the number of firms, with or without an exemption for small firms. Food safety regulations affect the composition of firms and may even create entry by less efficient firms. The article discusses implications of the Food Safety Modernization Act which includes exemption for small firms. [EconLit citations: D21, L51, Q18]. C � 2014
Cardiovascular disease is the leading cause of death among endometrial cancer patients

Abstract Objective To evaluate the causes of death among women with endometrial cancer. Methods SEER registries from 1973–1988 were queried to perform a retrospective cohort study of women with invasive epithelial endometrial cancer. Causes of death were compared according to grade and stage. Results 33,232 women with incident cases of endometrial cancer had died at the time of last follow up. Overall, women were most likely to die from cardiovascular disease (35.9%, 95% CI 35.3–36.3%), followed by other causes, other malignancies, and endometrial cancer. Women with low grade localized cancer were most likely to die of cardiovascular disease, while women with high grade advanced cancer were least likely to die of cardiovascular disease and most likely to die of endometrial cancer. For the entire population, risk of death from cardiovascular causes surpasses the risk of death from endometrial cancer 5years after diagnosis. Conclusions Higher risk of cardiac death among endometrial cancer patients likely reflects the high probability of curative cancer treatment and the prevalence of cardiac disease and risk factors. As the probability of dying of endometrial cancer decreases with time, the probability of dying of cardiovascular disease increases. Interventions and investigations aimed at addressing risk factors for cardiovascular disease may have the greatest potential to improve survival for women diagnosed with endometrial cancer and should feature prominently in treatment and survivorship plans.
Augmented Pulmonary Responses to Acute Ozone Exposure in Obese Mice: Roles of TNFR2 and IL-13

Background: Acute ozone (O3) exposure results in greater inflammation and airway hyperresponsiveness (AHR) in obese versus lean mice. Objectives: We examined the hypothesis that these augmented responses to O3 are the result of greater signaling through tumor necrosis factor receptor 2 (TNFR2) and/or interleukin (IL)-13. Methods: We exposed lean wild-type (WT) and TNFR2-deficient (TNFR2–/–) mice, and obese Cpefat and TNFR2-deficient Cpefat mice (Cpefat/TNFR2–/–), to O3 (2 ppm for 3 hr) either with or without treatment with anti–IL-13 or left them unexposed. Results: O3-induced increases in baseline pulmonary mechanics, airway responsiveness, and cellular inflammation were greater in Cpefat than in WT mice. In lean mice, TNFR2 deficiency ablated O3-induced AHR without affecting pulmonary inflammation; whereas in obese mice, TNFR2 deficiency augmented O3-induced AHR but reduced inflammatory cell recruitment. O3 increased pulmonary expression of IL-13 in Cpefat but not WT mice. Flow cytometry analysis of lung cells indicated greater IL-13–expressing CD4+ cells in Cpefat versus WT mice after O3 exposure. In Cpefat mice, anti–IL-13 treatment attenuated O3-induced increases in pulmonary mechanics and inflammatory cell recruitment, but did not affect AHR. These effects of anti–IL-13 treatment were not observed in Cpefat/TNFR2–/– mice. There was no effect of anti–IL-13 treatment in WT mice. Conclusions: Pulmonary responses to O3 are not just greater, but qualitatively different, in obese versus lean mice. In particular, in obese mice, O3 induces IL-13 and IL-13 synergizes with TNF via TNFR2 to exacerbate O3-induced changes in pulmonary mechanics and inflammatory cell recruitment but not AHR.
Sketch-based Influence Maximization and Computation: Scaling up with Guarantees

Propagation of contagion through networks is a fundamental process. It is used to model the spread of information, influence, or a viral infection. Diffusion patterns can be specified by a probabilistic model, such as Independent Cascade (IC), or captured by a set of representative traces. Basic computational problems in the study of diffusion are influence queries (determining the potency of a specified seed set of nodes) and Influence Maximization (identifying the most influential seed set of a given size). Answering each influence query involves many edge traversals, and does not scale when there are many queries on very large graphs. The gold standard for Influence Maximization is the greedy algorithm, which iteratively adds to the seed set a node maximizing the marginal gain in influence. Greedy has a guaranteed approximation ratio of at least (1-1/e) and actually produces a sequence of nodes, with each prefix having approximation guarantee with respect to the same-size optimum. Since Greedy does not scale well beyond a few million edges, for larger inputs one must currently use either heuristics or alternative algorithms designed for a pre-specified small seed set size. We develop a novel sketch-based design for influence computation. Our greedy Sketch-based Influence Maximization (SKIM) algorithm scales to graphs with billions of edges, with one to two orders of magnitude speedup over the best greedy methods. It still has a guaranteed approximation ratio, and in practice its quality nearly matches that of exact greedy. We also present influence oracles, which use linear-time preprocessing to generate a small sketch for each node, allowing the influence of any seed set to be quickly answered from the sketches of its nodes.
Constellation Design for the Noncoherent MIMO Rayleigh-Fading Channel at General SNR

Constellation design for the noncoherent multiple-input-multiple-output (MIMO) block Rayleigh-fading channel is considered. For general signal-to-noise ratios (SNRs), starting from a given base unitary constellation of finite cardinality, and using the cutoff rate expression as the design criterion, input probabilities and per-antenna amplitudes for the constellation points are obtained via a difference of convex programming formulation. Using the mutual information as a performance metric, it is shown that the optimized constellations significantly outperform the base unitary designs from which they are obtained in the low-medium SNR regime, and indeed they also similarly outperform the mutual information achieved by isotropically distributed unitary inputs for the continuous input channel [i.e., the so-called unitary space-time capacity (USTC)]. At sufficiently high SNRs, the resulting mutual information coincides with that of the base unitary designs. Thus the optimum constellation design technique works over the entire range of SNRs. The bit energy/spectral efficiency tradeoff of the optimized constellations are also obtained, and these provide valuable insights on modulation and coding, which are especially useful for wideband channels where the SNR per degree of freedom is low
TITANIUM-MEDIATED SYNTHESIS OF CONJUGATED DIENES

Abstract Titanacyclobutenes, readily prepared from Cp2TiCH2·Al(CH3)2Cl and alkynes, react with ketones and aldehydes to afford metallacyclic products resulting from insertion into either the titanium-alkyl or the titanium-vinyl bond of the titanacyclobutene. The latter insertion products are thermally unstable, undergoing facile retro [4+2] cycloaddition to afford substituted 1,3-dienes in good yield.
Catalytic Double Carbonylation of Epoxides to Succinic Anhydrides: Catalyst Discovery, Reaction Scope, and Mechanism

The first catalytic method for the efficient conversion of epoxides to succinic anhydrides via one-pot double carbonylation is reported. This reaction occurs in two stages: first, the epoxide is carbonylated to a β-lactone, and then the β-lactone is subsequently carbonylated to a succinic anhydride. This reaction is made possible by the bimetallic catalyst [(ClTPP)Al(THF)2]+[Co(CO)4]- (1; ClTPP = meso-tetra(4-chlorophenyl)porphyrinato; THF = tetrahydrofuran), which is highly active and selective for both epoxide and lactone carbonylation, and by the identification of a solvent that facilitates both stages. The catalysis is compatible with substituted epoxides having aliphatic, aromatic, alkene, ether, ester, alcohol, nitrile, and amide functional groups. Disubstituted and enantiomerically pure anhydrides are synthesized from epoxides with excellent retention of stereochemical purity. The mechanism of epoxide double carbonylation with 1 was investigated by in situ IR spectroscopy, which reveals that the t...
Drop formation from a wettable nozzle

Abstract The process of drop formation from a nozzle can be seen in many natural systems and engineering applications. However, previous research focuses on the pinch-off mechanism of drops from a non-wettable nozzle. Here we investigate the formation of a liquid droplet from a wettable nozzle. In the experiments, drops forming from a wettable nozzle initially climb the outer walls of the nozzle due to surface tension. Then, when the weight of the drops gradually increases, they eventually fall due to gravity. By changing the parameters such as the nozzle size and fluid flow rate, we have observed different behaviors of the droplets. Such oscillatory behavior is characterized by an equation that consists of capillary force, viscous drag, and gravity. Two asymptotic solutions in the initial and later stages of drop formation are obtained and show good agreement with the experimental observations.
Channel state prediction, feedback and scheduling for a multiuser MIMO-OFDM downlink

We consider the downlink of a MIMO-OFDM wireless systems where the base-station (BS) has M antennas and serves K ges M single-antenna user terminals (UTs). Users estimate their channel vectors from common downlink pilot symbols and feed back a prediction, which is used by the BS to compute the linear beamforming matrix for the next time slot and to select the users to be served according to the proportional fair scheduling (PFS) algorithm. We consider a realistic physical channel model used as a benchmark in standardization and some alternatives for the channel estimation and prediction scheme. We show that a parametric method based on ESPRIT is able to accurately predict the channel even for relatively high user mobility. However, there exists a class of channels characterized by large Doppler spread (high mobility) and clustered angular spread for which prediction is intrinsically difficult and all considered methods fail. We propose a modified PFS that take into account the ldquopredictabilityrdquo state of the UTs, and significantly outperform the classical PFS in the presence of prediction errors. The main conclusion of this work is that multiuser MIMO downlink yields very good performance even in the presence of high mobility users, provided that the non-predictable users are handled appropriately.
A parametric study of fracture toughness of fibrous composite materials

Impacts to fibrous composite laminates by objects with low velocities can break fibers giving crack-like damage. The damage may not extend completely through a thick laminate. The tension strength of these damage laminates is reduced much like that of cracked metals. The fracture toughness depends on fiber and matrix properties, fiber orientations, and stacking sequence. Accordingly, a parametric study was made to determine how fiber and matrix properties and fiber orientations affect fracture toughness and notch sensitivity. The values of fracture toughness were predicted from the elastic constants of the laminate and the failing strain of the fibers using a general fracture toughness parameter developed previously. For a variety of laminates, values of fracture toughness from tests of center-cracked specimens and values of residual strength from tests of thick laminates with surface cracks were compared to the predictions to give credibility to the study. In contrast to the usual behavior of metals, it is shown that both ultimate tensile strength and fracture toughness of composites can be increased without increasing notch sensitivity.
Enantioselective conjugate addition of hydroxylamines to pyrazolidinone acrylamides.

Chiral relay templates provide amplification of selectivity in conjugate addition reactions. Reversal of stereochemistry of the product isoxazolidinones has also been demonstrated by a simple change of the Lewis acid.
Multiple trellis coded modulation (MTCM)

The authors demonstrate a trellis coded modulation technique referred to as multiple trellis coded modulation (MTCM) wherein more than one channel symbol per trellis branch is transmitted. They have found simple two-state trellis codes for symmetric MPSK multiple phase-shift keying and AM modulations that can achieve 3-dB gain over uncoded modulation at very high signal-to-noise ratios without bandwidth expansion or reduction in information bit rate. The gain of these codes with respect to previously reported two-state trellis codes is between 1 and 2 dB at very high signal-to-noise ratios, depending on the number of bits per Hertz transmitted. These gains are achieved for those of the equivalent conventional trellis codes with the same number of states in the trellis diagram. The authors note that additional computations per branch are needed for the multiple trellis coding scheme. The concept can be extended to a higher number of states and other types of modulations. >
DYNAMICS OF LINE-DRIVEN WINDS FROM DISKS IN CATACLYSMIC VARIABLES. II. MASS-LOSS RATES AND VELOCITY LAWS

We analyze the dynamics of two-dimensional stationary, line-driven winds from accretion disks in cataclysmic variable (CV) stars by generalizing the formalism of Castor, Abbott, and Klein (CAK) for O stars. In Paper I, we solved the wind Euler equation, derived its two eigenvalues, and addressed the solution topology and wind geometry. Here, we focus on mass-loss rates and velocity laws of the wind. We find that disk winds, even in luminous nova-like variables, have low optical depth, even in the strongest driving lines. This suggests that thick-to-thin transitions in these lines occur in the wind. For disks with a realistic radial temperature law, the mass loss is dominated by gas emanating from the inner decade in radius. The total mass-loss rate associated with the wind from a disk of luminosity 10 L☉ is ~10-12 M☉ yr-1, or 10-4 of the mass accretion rate. This is 1 order of magnitude below the lower limit obtained from fitting P Cygni line profiles using kinematical wind models when the Lyman continuum is suppressed. The difficulties associated with such small mass-loss rates for line-driven winds from disks in CVs are principal and confirm our previous work on this subject. We conjecture that this issue may be resolved by detailed non-LTE calculations of the CAK line force within the context of CV disk winds and/or by better accounting for the disk energy distribution and wind ionization structure. We find that the wind velocity profile is well approximated by the empirical law used in kinematical modeling. The acceleration length scale is given by the footpoint radius of the wind streamline in the disk. This suggests an upper limit of ~10rwd to the acceleration scale, which is smaller by factor of a few as compared with values derived from line fitting.
New Directing Groups for Metal-Catalyzed Asymmetric Carbon–Carbon Bond-Forming Processes: Stereoconvergent Alkyl–Alkyl Suzuki Cross-Couplings of Unactivated Electrophiles

The ability of two common protected forms of amines (carbamates and sulfonamides) to serve as directing groups in nickel-catalyzed Suzuki reactions has been exploited in the development of catalytic asymmetric methods for cross-coupling unactivated alkyl electrophiles. Racemic secondary bromides and chlorides undergo carbon–carbon bond formation in a stereoconvergent process in good ee at room temperature in the presence of a commercially available nickel complex and chiral ligand. Structure-enantioselectivity studies designed to elucidate the site of binding to nickel (the oxygen of the carbamate and of the sulfonamide) led to the discovery that sulfones also serve as useful directing groups for asymmetric Suzuki cross-couplings of racemic alkyl halides. To the best of our knowledge, this investigation provides the first examples of the use of sulfonamides or sulfones as effective directing groups in metal-catalyzed asymmetric carbon–carbon bond-forming reactions. A mechanistic study established that transmetalation occurs with retention of stereochemistry and that the resulting nickel–carbon bond does not undergo homolysis in subsequent stages of the catalytic cycle.
Vibroacoustic launch analysis and alleviation of lightweight, active mirrors

Lightweight, active, silicon carbide mirrors can increase the capability of space-based optical systems. However, launch survival is a serious concern for such systems, with the vibrations and acoustics from launch threatening to damage the optics. Therefore, a dynamic, state- space launch model has been developed with which one can quickly analyze the survival probability of many designs and also directly analyze launch load alleviation techniques. This paper discusses the launch model from which launch stress and survival probability are obtained, as well as launch load alleviation techniques that may increase the probability of launch survival. Three launch load alleviation techniques are presented and analyzed: whole spacecraft isolation, passive shunt circuits using the existing embedded actuators, and active damping using the existing ac- tuators. All of the techniques reduce the launch stress, but at the expense of mass and complexity. The launch model allows for early identification of lightweight, active mirror designs which will survive launch, and the alleviation techniques expand the feasible design space by decreasing the launch stress and increasing the probability of launch survival. C 2011
Strategic Firms and Endogenous Consumer Emulation

Better informed consumers may be treated preferentially by firms since their consumption serves as a quality signal for other customers. For normal goods this results in wealthy individuals being treated better than poor individuals. We investigate this phenomenon in an equilibrium model of social learning with heterogeneous consumers and firms that act strategically. Consumers search for high quality firms and condition their choices on observed actions of other consumers. When they observe consumers who are more likely to have identified a high quality firm, uninformed individuals will optimally emulate those consumers. One group of consumers arises endogenously as “leaders” whose consumption behavior is emulated. Follow-on sales induce firms to give preferential treatment to these lead consumers, which reinforces their learning.
A computational model of the semantics of tense and aspect

The PUNDIT natural-language system processes references to situations and the intervals over which they hold using an algorithm that integrates the analysis of tense and aspect. For each tensed clause, PUNDIT processes the main verb and its grammatical categories of tense, perfect, and progressive in order to extract three complementary pieces of temporal information. The first is whether a situation has actual time associated with it. Secondly, for each situation that is presumed to take place in actual time, PUNDIT represents its temporal structure as one of three situation types: a state, process, or transition event. The temporal structures of each of these situation types consist of one or more intervals. The intervals are characterized by two features: kinesis, which pertains to their internal structure, and boundedness, which constrains the manner in which they get located in time. Thirdly, the computation of temporal location exploits the three temporal indices proposed in Reichenbach 1947: event time, speech time, and reference time. Here, however, event time is formulated as a single component of the full temporal structure of a situation in order to provide an integrated treatment of tense and aspect.
Escaping Earth: Human Spaceflight as Religion

*UCH attention has been given to the influence of the Cold War in explaining the United States‘ embarkation in the difficult task of exploring space with humans. The commitment to human space exploration, begun at the height of the Cold War and gaining ever greater credence through the race to the Moon along with its slow decline in the last 40 years, has remained even as the reasons fostering its origination have waned. At some level there seems to be something more to the support for human spaceflight than just practicality and Realpolitik. There may be what I would call a deeply religious quality to advocacy for the investment in and support for human space exploration, lending to the endeavor a ―higher purpose‖ that helps to explain both the generous nature of the actual investment and the ultimate unwillingness of Americans to eviscerate space budgets. This unusual and potentially blasphemous proposition may disturb the faithful (those who embrace the spacefaring religion as well as those accepting the faith claims of various more traditional churches), but I argue in this essay that it helps explain much of the hold human space exploration has enjoyed within its supporting community. I lay out here the proposition that human spaceflight may be viewed as a religion with similar attributes to those present in mainstream religious denominations. While this approach to exploring the history of human spaceflight might not be fully satisfying, it offers a different frame of understanding that broadens basic conceptions. This essay represents the first attempt to lay out these ideas, but eventually my intent is to write a lengthy treatise on the subject tracing the history of spaceflight as religion from the early twentieth century to the present using a biographical approach of key advocates over time.