cssi/SciSciGPT-SciSciNet huggingface dataset:
Order of Magnitude Comparisons of Distance

Order of magnitude reasoning -- reasoning by rough comparisons of the sizes of quantities -- is often called "back of the envelope calculation", with the implication that the calculations are quick though approximate. This paper exhibits an interesting class of constraint sets in which order of magnitude reasoning is demonstrably fast. Specifically, we present a polynomial-time algorithm that can solve a set of constraints of the form "Points a and b are much closer together than points c and d". We prove that this algorithm can be applied if "much closer together" is interpreted either as referring to an infinite difference in scale or as referring to a finite difference in scale, as long as the difference in scale is greater than the number of variables in the constraint set. We also prove that the first-order theory over such constraints is decidable.
Terrestrial, Habitable-Zone Exoplanet Frequency from Kepler

Data from Kepler's first 136 days of operation are analyzed to determine the distribution of exoplanets with respect to radius, period, and host-star spectral type. The analysis is extrapolated to estimate the percentage of terrestrial, habitable-zone (HZ) exoplanets. The Kepler census is assumed to be complete for bright stars (magnitude 0.5 Earth radius and periods <42 days. It is also assumed that the size distribution of planets is independent of orbital period and that there are no hidden biases in the data. Six significant statistical results are found: there is a paucity of small planet detections around faint target stars, probably an instrumental effect; the frequency of mid-size planet detections is independent of whether the host star is bright or faint; there are significantly fewer planets detected with periods <3 days, compared to longer periods, almost certainly an astrophysical effect; the frequency of all planets in the population with periods <42 days is 29%, broken down as terrestrials 9%, ice giants 18%, and gas giants 3%; the population has a planet frequency with respect to period which follows a power-law relation dN/dP ~ P β – 1, with β 0.71 ± 0.08; and an extrapolation to longer periods gives the frequency of terrestrial planets in the HZs of FGK stars as η⊕ (34 ± 14)%. Thus about one-third of FGK stars are predicted to have at least one terrestrial, HZ planet.
Voluntary revelation of the demand for public goods using a provision point mechanism

A one-shot provision point mechanism with money-back guarantee and proportional rebate of excess contributions is tested in an induced value framework and in experimental environments chosen to mimic field conditions. The results show that this relatively simple mechanism is empirically demand revealing in the aggregate when used with large groups of students who have heterogenous valuations for the public good. Approximately demand revealing behavior was obtained under three alternative information conditions. These results are an important step in the design of a mechanism simple enough to allow field applications, but capable of efficiently providing public goods through voluntary contribu- tions. © 1999 Elsevier Science S.A. All rights reserved.
Ultraviolet Phase Conjugation And Its Practical Implications

We report the first demonstration of uv phase conjugation. Using a 15 psec, 2660 A pulse, 0.1% conjugate reflectivities were obtained via degenerate four-wave mixing in 1-mm samples of CS/sub 2/ mixtures. While pure CS/sub 2/ did not exhibit the effect, dilution in several uv transmitting solvents opened up a concentration-tunable (2450 A to 2850 A) spectral window, allowing the optical Kerr effect to be utilized. Weaker phase conjugation at 2660 A was also observed in other Kerr media and in saturable absorber media.
Information Transparency of Business-to-Business Electronic Markets: A Game-Theoretic Analysis

The abundance of transaction data available on the Internet tends to make information more transparent in electronic marketplaces. In such a transparent environment, it becomes easier for suppliers to obtain information that may allow them to infer their rivals' costs. Is this good news or bad news? In this study, we focus on theinformational effects of business-to-business (B2B) exchanges, and explore firms' incentives to join a B2B exchange that provides an online platform for information transmission. We then study the equilibria by developing a game-theoretic model under asymmetric information. We examine whether the incentives to join a B2B exchange would be different under different competition modes (quantity and price), different information structures, and by varying the nature of the products (substitutes and complements). Our results challenge the "information transparency hypothesis" (i.e., open sharing of information in electronic markets is beneficial to all participating firms). In contrast to the popular belief, we show that information transparency could be a double-edged sword. The individual rationality of participation in the online exchange reflects the tradeoff between information transparency and data confidentiality. This may have important implications for the microstructure design (e.g., data access rules) of B2B electronic marketplaces.
On-chip power-supply network optimization using multigrid-based technique

In this paper, we present a novel multigrid-based technique for the problem of on-chip power-supply network optimization. The multigrid-based technique is applied to reduce a large-scale network to a much coarser one. The reduced network can be efficiently optimized. The solution for the original network is then quickly computed using a back-mapping process. Due to the adoption of an accurate resistance-inductance-capacitance power-supply network and time-varying switching-current model, our technique is capable of optimizing power grid and decoupling capacitance simultaneously. Experimental results show that large-scale power-supply networks with millions of nodes can be solved in a few minutes. The proposed technique not only speeds up significantly the optimization process, without compromising the quality of solutions, but also brings up a possibility of incorporating the power-supply network optimization into other physical design stages such as signal routing.
The risk premia embedded in index options

We study the dynamic relation between aggregate stock market risks and risk premia via an exploration of the time series of equity-index option surfaces. The analysis is based on estimating a general parametric asset pricing model for the risk-neutral equity market dynamics using a panel of options on the S&P 500 index, while remaining fully nonparametric about the actual evolution of market risks. We nd that the risk-neutral jump intensity, which controls the pricing of left tail risk, cannot be spanned by the market volatility (and its components), so an additional factor is required to account for its dynamics. This tail factor has no incremental predictive power for future equity return volatility or jumps beyond what is captured by the current and past level of volatility. In contrast, the novel factor is critical in predicting the future market excess returns over horizons up to one year, and it explains a large fraction of the future variance risk premium. We contrast our ndings with those implied by structural asset pricing models that seek to rationalize the predictive power of option data. Relative to those studies, our ndings suggest a wider wedge between the dynamics of equity market risks and the corresponding risk premia with the latter typically displaying a far more persistent reaction following market crises.
THE ADVECTION OF SUPERGRANULES BY THE SUN'S AXISYMMETRIC FLOWS

We show that the motions of supergranules are consistent with a model in which they are simply advected by the axisymmetric flows in the Sun’s surface shear layer. We produce a 10 day series of simulated Doppler images at a 15 minute cadence that reproduces most spatial and temporal characteristics seen in the SOHO/MDI Doppler data. Our simulated data have a spectrum of cellular flows with just two components—a granule component that peaks at spherical wavenumbers of about 4000 and a supergranule component that peaks at wavenumbers of about 110. We include the advection of these cellular components by the axisymmetric flows—differential rotation and meridional flow—whose variations with latitude and depth (wavenumber) are consistent with observations. We mimic the evolution of the cellular pattern by introducing random variations to the phases of the spectral components at rates that reproduce the levels of cross-correlation as functions of time and latitude. Our simulated data do not include any wave-like characteristics for the supergranules yet can reproduce the rotation characteristics previously attributed to wave-like behavior. We find rotation rates which appear faster than the actual rotation rates and attribute this to projection effects. We find that the measured meridional flow does accurately represent the actual flow and that the observations indicate poleward flow to 65 ◦ –70 ◦ latitude with equatorward countercells in the polar regions.
Rectangle size bounds and threshold covers in communication complexity

We investigate the power of the most important lower bound technique in randomized communication complexity, which is based on an evaluation of the maximal size of approximately monochromatic rectangles, with respect to arbitrary distributions on the inputs. While it is known that the 0-error version of this bound is polynomially tight for deterministic communication, nothing in this direction is known for constant error and randomized communication complexity. We first study a one-sided version of this bound and obtain that its value lies between the MA- and AM- complexities of the considered function. Hence the lower bound actually works for a (communication) complexity class between MA/spl cap/co - MA and AM/spl cap/co - AM, and allows to show that the MA-complexity of the disjointness problem is /spl Omega/(/spl radic/n). Following this we consider the conjecture that the lower bound method is polynomially tight for randomized communication complexity. First we disprove a distributional version of this conjecture. Then we give a combinatorial characterization of the value of the lower bound method, in which the optimization over all distributions is absent. This characterization is done by what we call a bounded error uniform threshold cover, and reduces showing tightness of the bound to the construction of an efficient protocol for a specific communication problem. We then study relaxations of bounded error uniform threshold covers, namely approximate majority covers and majority covers, and exhibit exponential separations between them. Each of these covers captures a lower bound method previously used for randomized communication complexity.
Estimating and testing a quantile regression model with interactive effects

This paper proposes a quantile regression estimator for a panel data model with interactive effects potentially correlated with the independent variables. We provide conditions under which the slope parameter estimator is asymptotically Gaussian. Monte Carlo studies are carried out to investigate the finite sample performance of the proposed method in comparison with other candidate meth- ods. We discuss an approach to testing the model specification against a competing fixed effects specification. The paper presents an empirical application of the method to study the effect of class size and class composition on educational attainment. The findings show that (i) a change in the gender composition of a class impacts differently low- and high-performing students; (ii) while smaller classes are beneficial for low performers, larger classes are beneficial for high performers; (iii) reductions in class size do not seem to impact mean and median student performance; (iv) the fixed effects specification is rejected in favor of the interactive effects specification.
A Catalog of MIPSGAL Disk and Ring Sources

We present a catalog of 416 extended, resolved, disk and ringlike objects as detected in the MIPSGAL 24 μm survey of the Galactic plane. This catalog is the result of a search in the MIPSGAL image data for generally circularly symmetric, extended "bubbles" without prior knowledge or expectation of their physical nature. Most of the objects have no extended counterpart at 8 μm or 70 μm, with less than 20% detections at each wavelength. For the 54 objects with central point sources, the sources are nearly always seen in all Infrared Array Camera bands. About 70 objects (16%) have been previously identified, with another 35 listed as Infrared Astronomical Satellite sources. Among the identified objects, those with central sources are mostly listed as emission-line stars, but with other source types including supernova remnants (SNRs), luminous blue variables, and planetary nebulae (PNe). The 57 identified objects (of 362) without central sources are nearly all PNe (~90%), which suggests that a large fraction of the 300+ unidentified objects in this category are also PNe. These identifications suggest that this is primarily a catalog of evolved stars. Also included in the catalog are two filamentary objects that are almost certainly SNRs, and 10 unusual compact extended objects discovered in the search. Two of these show remarkable spiral structure at both 8 μm and 24 μm. These are likely background galaxies previously hidden by the intervening Galactic plane.
Effects of orbital evolution on lunar ice stability

[1] Many regions near the lunar poles are currently cold enough that surface water ice would be stable against sublimation losses for billions of years. However, most of these environments are currently too cold to efficiently drive ice downward by thermal diffusion, leaving impact burial as the primary means of protection from surface loss processes. In this respect, most of the present near-surface thermal environments on the Moon may actually be quite poor traps for water ice. This was not always the case. Long-term orbital changes have dramatically altered the lunar polar thermal environment. We develop a simple model of the evolution of the lunar orbit and spin axis to examine the thermal environments available for volatile deposition and retention in the past. Our calculations show that some early lunar polar environments were in the right temperature regime to have collected subsurface ice if a supply were available. However, a high-obliquity period, which occurred when the Moon was at about half its present distance from the Earth, would either have driven this ice out into space or deep into the lunar subsurface. Since that time, as the lunar obliquity has slowly decreased to its present value, environments have undergone their own thermal evolution, and each of the current cold traps experienced a period when they were most efficient at thermally burying ice. We examine the thermal history of a lunar polar crater to provide a framework for examining other processes effecting volatiles in the Moon's near-surface cold traps.
Trends in Ultracool Dwarf Magnetism. II. The Inverse Correlation Between X-Ray Activity and Rotation as Evidence for a Bimodal Dynamo

Observations of magnetic activity indicators in solar-type stars exhibit a relationship with rotation with an increase until a "saturation" level and a moderate decrease in activity in the very fastest rotators ("supersaturation"). While X-ray data have suggested that this relationship is strongly violated in ultracool dwarfs (UCDs; spectral type M7), the limited number of X-ray detections has prevented firm conclusions. In this paper, we analyze the X-ray activity-rotation relation in 38 UCDs. Our sample represents the largest catalog of X-ray active UCDs to date, including seven new and four previously unpublished Chandra observations presented in a companion paper. We identify a substantial number of rapidly rotating UCDs with X-ray activity extending two orders of magnitude below the expected saturation level and measure a "supersaturation"-type anticorrelation between rotation and X-ray activity. The scatter in UCD X-ray activity at a fixed rotation is ~3 times larger than that in earlier-type stars. We discuss several mechanisms that have been proposed to explain the data, including centrifugal stripping of the corona, and find them to be inconsistent with the observed trends. Instead, we suggest that an additional parameter correlated with both X-ray activity and rotation is responsible for the observed effects. Building on the results of Zeeman-Doppler imaging of UCD magnetic fields and our companion study of radio/X-ray flux ratios, we argue that this parameter is the magnetic field topology, and that the large scatter in UCD X-ray fluxes reflects the presence of two dynamo modes that produce distinct topologies.
The long reach of liver transplantation.

After graduating from high school in my hometown of Le Mars, Iowa, I had a stint in the US Navy (1944–1945), earned a BA degree from Westminster College in Missouri (1947) and completed two years of medical school at Northwestern University (1947–1949). I then dropped out to do research in neurophysiology under the inspiring tutelage of Horace W. Magoun, first at Northwestern and subsequently at the then-new medical school of the University of California, Los Angeles. With MD and PhD degrees from Northwestern, I served a one-year internship at Johns Hopkins Hospital before doing a full-time, 18-month study of complete heart block, which was a frequent complication with the first human open-heart operations. The experiments involved creation of a canine model of heart block and treatment of its adverse consequences with repetitive low-voltage ventricular stimulation—the first epicardial pacemaking.
Structural Characterization of a Plutonium Sequestering Agent Complex by Synchrotron X-Ray Diffraction

New ligands and materials are required that can coordinate, sense, and purify actinides for selective extraction and reduction of toxic, radioactive wastes from the mining and purification of actinides. The similarities in the chemical, biological transport, and distribution properties of Fe(III) and Pu(IV) inspired a biomimetic approach to the development of sequestering agents for actinides. A detailed evaluation of the structure and bonding of actinide coordinating ligands like these is important for the design of new selective ligand systems. Knowing the difficulty with working with the crystals resulting from these ligand systems and safe handling considerations for working with Pu, procedures were developed that utilize the Advanced Light Source of Lawrence Berkeley National Laboratory to determine the solid-state structures of Pu complexes by X-ray diffraction.
Injected propellant ionization in MPD thrusters

A model is presented for the selfmagnetized, weakly ionized preionization region at the entrance to a magnetoplasmadynamic (MPD) accelerator. The model is steady, one-dimensional and inviscid, and assumes supersonic flow of argon plasma with zero current in the region. Heavy particle temperature is constant, and electron temperature Te is determined by ambipolar diffusion and by photoand electron-impact ionization processes. The plasma continuity, momentum and energy equations are integrated numerically with appropriate boundary conditions, giving a region width Ax ranging from 3 to 17 mm, depending on density, and a degree of ionization a increasin from an initial value of inlet. The electron temperature rises monotonically from Te=lOOO"K to Te~18,000'K, a level sufficient to sustain MPD accelerator operation. The total electrostatic potential across Ax is AV=12.5+0.6 V. Reducing the injected particle flux Qo increases Ax, until a critical Qo is reached below which no solutions exist. W a=IO-' to a = 4 f 2 ~ 1 0 3 at the MPD accelerator NOMENCLATURE j IRoss L n no nn Pe qe Qci
PSR switchyard kicker system improvements

A switchyard kicker system which allows time sharing of the beam between the Los Alamos WNR/LANSCE complex and other LAMPF (Los Alamos Meson Physics Facility) users was redesigned as part of the Proton Storage Ring addition. The system consists of two pulsers providing 1750 A, 1 ms pulses to a pair of 1 m-long ferrite magnets. The system was designed to operate at a 24 Hz maximum repetition rate. In 1986, a modification was made to the equipment to allow operation at 40 Hz. While the system operated reliably this way, some difficulties were observed. A desire on the part of the users to operate the system at 60 Hz coupled with a major system failure led to design changes to load resistors, drive cables, charging system, and cooling system. These changes are described along with an analysis of the difficulties encountered with the original hardware. >
Finite-Difference Time-Domain Formulation of Stochastic Noise in Macroscopic Atomic Systems

A numerical model based on the finite-difference time-domain method is developed to simulate fluctuations which accompany the dephasing of atomic polarization and the decay of excited state's population. This model is based on the Maxwell-Bloch equations with c-number stochastic noise terms. We successfully apply our method to a numerical simulation of the atomic superfluorescence process. This method opens the door to further studies of the effects of stochastic noise on light-matter interaction and transient processes in complex systems without prior knowledge of modes.
Development of a generic activation mode: nucleophilic α-substitution of ketones via oxy-allyl cations

Oxy-allyl cations have been known as transient electrophilic species since they were first proposed as intermediates in the Favorskii rearrangement in 1894. Since that time, they also have been used as a mode of activation for [4 + 3] cycloadditions in a variety of natural product syntheses. In this manuscript, we describe a method for the interception of oxy-allyl cations with a diverse range of common nucleophiles, thereby demonstrating the value of this intermediate as a generic mode of activation. This simple, mild, room temperature protocol allows for the formation of a variety of high value carbon–carbon and carbon–heteroatom bonds that are readily incorporated within a series of cyclic and acyclic ketone systems. Initial efforts into the development of an enantioselective catalytic variant are also described.
The Synthesis of Azapeptidomimetic β-Lactam Molecules as Potential Protease Inhibitors

Synthetic methods for the construction of a novel peptidomimetic structure are reported. The structure incorporates a β-lactam and an azapeptide in a peptide backbone with the intention of generating rationally designed substrate-based protease inhibitors. The β-lactam is formed by subjecting serine or threonine-azapeptides to Mitsunobu reaction conditions. Importantly, the azapeptidomimetic β-lactam structure permits extended binding inhibition and the synthetic methods to create tetrapeptidomimetic structures are described.
A reduced model of cavitation physics for use in sonochemistry

Sonochemistry involves focusing acoustic energy through cavitation bubbles to increase chemical activity. The violent bubble collapses lead to temperatures of several thousand kelvin, which drive c...
Oral fluid therapy of cholera among bangladesh refugees

In 1971 a crucial field trial of oral glucose-electrolyte solutions in the treatment of cholera was carried out in Bongaon India when the disease appeared in a population of war refugees. A total of 3703 patients including severe cases treated initially with limited supplies of parenteral fluids and mild to moderately severe cases treated with oral therapy alone were admitted to the Bongaon treatment center; the overall case/fatality ratio was 3.6%. A special demonstration unit provided treatment for 1190 of these patients with a case/fatality ratio of 1%. Advantages of the oral solution included local availability of ingredients minimal cost of preparation and transport ease of administration safety in the hands of inexperienced personnel after only brief instructions early accessibility of treatment and reasonable effectiveness especially when used very early in the course of the disease prior to extreme dehydration shock and acidosis. In severe cases considerable sparing of intravenous fluids resulted from the adjunct use of the oral solution.
Collective Bargaining and District Costs for Teacher Health Insurance: An Examination of the Data from the BLS and Wisconsin.

District costs for teachers’ health insurance are, on average, higher then employer costs for private-sector professionals. How much of this is attributable to collective bargaining? This article examines the question using data from the National Compensation Survey (NCS) of the Bureau of Labor Statistics (BLS) and the state of Wisconsin. In addition, the impact of collective bargaining on employer costs is decomposed into the impact on total premiums and the employer’s share of those premiums.
Application of 4,5-O,N-oxazolidinone protected thiophenyl sialosyl donor to the synthesis of α-sialosides

The synthesis of a novel oxazolidinone sialosyl donor is reported. The introduction of a trans-fused ring enhances reactivity and stereoselectivity in glycosylation reactions for the synthesis of α-sialosides. The oxazolidinone ring can also be removed under basic conditions to afford the deprotected amine, which can be further functionalized.
Simultaneous driver sizing and buffer insertion using a delay penalty estimation technique

To achieve timing closure in a placed design, buffer insertion and driver sizing are two of the most effective transforms that can be applied. Since the driver-sizing solution and the buffer-insertion solution affect each other, suboptimal solutions may result if these techniques are applied sequentially instead of simultaneously. We show how to simply extend van Ginneken's buffer-insertion algorithm to simultaneously incorporate driver sizing and introduce the idea of a delay penalty to encapsulate the effect of driver sizing on the previous stage. The delay penalty can be precomputed efficiently via dynamic programming. Experimental results show that using driver sizing with a delay-penalty function obtains designs with superior timing and area characteristics.
Made in the U.S.A.? A Study of Firm Responses to Domestic Production Incentives

How do U.S. companies respond to incentives intended to encourage domestic production and manufacturing? I study this question in the context of the Domestic Production Activities Deduction (DPAD), which was enacted in the American Jobs Creation Act of 2004 and is currently the third largest U.S. corporate tax expenditure. Specifically, I examine 1) whether and to what extent firms shift income to maximize the domestic manufacturing benefit, and 2) the extent that firms actually increase domestic investment and employment, measured using confidential data from the U.S. Bureau of Economic Analysis. While I find a positive effect of DPAD on domestic investment, I also find that DPAD firms shift income across time and (to a lesser extent) across borders to maximize the tax benefit. These results show that changes in firm reporting are an important and economically significant response that has not been studied previously in this context. Additionally, these findings inform the ongoing policy debate on the possible extension or repeal of this tax incentive.
Chemo- and Regioselective Hydrogenolysis of Diaryl Ether C−O Bonds by a Robust Heterogeneous Ni/C Catalyst: Applications to the Cleavage of Complex Lignin-Related Fragments

We report the chemo- and regioselective hydrogenolysis of the C-O bonds in di-ortho-substituted diaryl ethers under the catalysis of a supported nickel catalyst. The catalyst comprises heterogeneous nickel particles supported on activated carbon and furnishes arenes and phenols in high yields without hydrogenation. The high thermal stability of the embedded metal particles allows C-O bond cleavage to occur in highly substituted diaryl ether units akin to those in lignin. Preliminary mechanistic experiments show that this catalyst undergoes sintering less readily than previously reported catalyst particles that form from a solution of [Ni(cod)2].
An intervention analysis on the relationship between futures prices of non-GM and GM contract soybeans in China

In 2004, the Dalian Commodity Exchange (DCE) introduced a separate futures contract for No. 2 soybeans, which includes GM soybeans. With this change, the No. 1 soybean futures contract defaulted to a non-GM contract. We define the difference between the prices of non-GM and GM soybeans as the price premium for nonGM soybeans. An intervention analysis is used to test the effects of the events on the price premium. We investigate three events—two contract specification changes in 2005 and 2010 and one grain law implementation in 2012—focusing on both the direction and size of their impacts. In conclusion the contract specification changes did affect the price premium. It is also found the law issue has permanently increased the price premium. Studying the market response linkages between the two soybean futures markets is helpful for understanding whether the newly opened GM soybean futures market transmits price information effectively.
Hypersensitive Transport in Photonic Crystals with Accidental Spatial Degeneracies

A localized mode in a photonic layered structure can develop nodal points (nodal planes), where the oscillating electric field is negligible. Placing a thin metallic layer at such a nodal point results in the phenomenon of induced transmission. Here we demonstrate that if the nodal point is not a point of symmetry, then even a tiny alteration of the permittivity in the vicinity of the metallic layer drastically suppresses the localized mode along with the resonant transmission. This renders the layered structure highly reflective within a broad frequency range. Applications of this hypersensitive transport for optical and microwave limiting and switching are discussed.
Pollution abatement expenditures and plant-level productivity: A production function approach

Abstract This paper investigates the impact of pollution abatement expenditures on productivity, using plant-level data from the Census Bureau for 68 pulp and paper mills, 55 oil refineries, and 27 steel mills for the 1979–1990 period. We estimate a Cobb–Douglas production function to measure the contribution of capital, labor, and materials inputs to output. Our data on pollution abatement expenditures allows us to distinguish between productive and abatement expenditures for each input. We find that abatement expenditures contribute little or nothing to production, although they do not have significant negative effects on the productivity of non-abatement inputs. We also examine within-industry heterogeneity, estimating separate impacts for subgroups of plants, based on their production technology and their types of pollution abatement investment, but find little evidence for significant differences across these groups.
Rh-Catalyzed Intermolecular Reactions of α-Alkyl-α-Diazo Carbonyl Compounds with Selectivity over β-Hydride Migration

ConspectusRh-carbenes derived from α-diazocarbonyl compounds have found broad utility across a remarkable range of reactivity, including cyclopropanation, cyclopropenation, C–H insertions, heteroatom–hydrogen insertions, and ylide forming reactions. However, in contrast to α-aryl or α-vinyl-α-diazocarbonyl compounds, the utility of α-alkyl-α-diazocarbonyl compounds had been moderated by the propensity of such compounds to undergo intramolecular β-hydride migration to give alkene products. Especially challenging had been intermolecular reactions involving α-alkyl-α-diazocarbonyl compounds.This Account discusses the historical context and prior limitations of Rh-catalyzed reactions involving α-alkyl-α-diazocarbonyl compounds. Early studies demonstrated that ligand and temperature effects could influence chemoselectivity over β-hydride migration. However, effects were modest and conflicting conclusions had been drawn about the influence of sterically demanding ligands on β-hydride migration. More recent adva...
Concerted activities of Mcm4, Sld3 and Dbf4 in control of origin activation and DNA replication fork progression

Eukaryotic chromosomes initiate DNA synthesis from multiple replication origins in a temporally specific manner during S phase. The replicative helicase Mcm2-7 functions in both initiation and fork progression and thus is an important target of regulation. Mcm4, a helicase subunit, possesses an unstructured regulatory domain that mediates control from multiple kinase signaling pathways, including the Dbf4-dependent Cdc7 kinase (DDK). Following replication stress in S phase, Dbf4 and Sld3, an initiation factor and essential target of Cyclin-Dependent Kinase (CDK), are targets of the checkpoint kinase Rad53 for inhibition of initiation from origins that have yet to be activated, so-called late origins. Here, whole-genome DNA replication profile analysis is used to access under various conditions the effect of mutations that alter the Mcm4 regulatory domain and the Rad53 targets, Sld3 and Dbf4. Late origin firing occurs under genotoxic stress when the controls on Mcm4, Sld3, and Dbf4 are simultaneously eliminated. The regulatory domain of Mcm4 plays an important role in the timing of late origin firing, both in an unperturbed S phase and in dNTP limitation. Furthermore, checkpoint control of Sld3 impacts fork progression under replication stress. This effect is parallel to the role of the Mcm4 regulatory domain in monitoring fork progression. Hypomorph mutations in sld3 are suppressed by a mcm4 regulatory domain mutation. Thus, in response to cellular conditions, the functions executed by Sld3, Dbf4, and the regulatory domain of Mcm4 intersect to control origin firing and replication fork progression, thereby ensuring genome stability.
Using bioethics discourse to determine when parents should make health care decisions for their children: is deference justified?

This Article critiques the current law governing health care decisionmaking for children, and proposes changes in the law consistent with bioethics principles. The basic criticism of existing law is that it is rooted in a rights-based discourse, in which the sick child's interests are decided in the shadow of a parental deference presumption. As a result, too much deference is given to some parents and too little deference to others. Moreover, many of these cases are decided in the context of abuse and neglect, which fails to recognize the moral nature of these medico-ethical decisions. This Article proposes that the rights-based discourse be replaced by a bioethics discourse, guided by the core principles of beneficence and autonomy. With this change in focus, parents would be entitled to deference to the extent the patient's interests were futhered. Specifically, parents would be able to make health care decisions, unless they possessed a conflict of interest making it unlikely that they would be able to serve the child patient's interests. The Article sets forth a taxonomy of categorical and situational conflicts. If a conflict exists, a court must determine the patient's best interests. If a conflict does not exist, parents can make health care decisions within a protected zone of privacy.
Light Wood Trusses

New equipment for testing wood trusses applies load through system of cables and sheaves; testing of nailed and glued trusses; each reaction is measured by calibrated load cell; tables give stress values for various spans and slopes, and for various constructions of trusses; advantages of light wood trusses; jointing techniques.
Adipocytes enhance murine pancreatic cancer growth via a hepatocyte growth factor (HGF)-mediated mechanism.

Abstract Introduction Obesity accelerates the development and progression of pancreatic cancer, though the mechanisms underlying this association are unclear. Adipocytes are biologically active, producing factors such as hepatocyte growth factor (HGF) that may influence tumor progression. We therefore sought to test the hypothesis that adipocyte-secreted factors including HGF accelerate pancreatic cancer cell proliferation. Material and methods Murine pancreatic cancer cells (Pan02 and TGP-47) were grown in a) conditioned medium (CM) from murine F442A preadipocytes, b) HGF-knockdown preadipocyte CM, c) recombinant murine HGF at increasing doses, and d) CM plus HGF-receptor (c-met) inhibitor. Cell proliferation was measured using the MTT assay. ANOVA and t -test were applied; p Results Wild-type preadipocyte CM accelerated Pan02 and TGP-47 cell proliferation relative to control (59 ± 12% and 34 ± 12%, p Conclusions These experiments demonstrate that adipocyte-derived factors accelerate murine pancreatic cancer proliferation. In the case of Pan02 cells, HGF is responsible, in part, for this proliferation.
Complete coherent control of a strongly coupled quantum dot-cavity polariton system

We investigated an ultrafast phonon-assisted population transfer between polaritons from a strongly coupled quantum dot-photonic crystal cavity system. In particular, we demonstrated complete coherent control and single-photon generation from a polariton.
Rhodium-Catalyzed Enantioselective Cycloisomerization to Cyclohexenes Bearing Quaternary Carbon Centers

We report a Rh-catalyzed enantioselective cycloisomerization of α,ω-heptadienes to afford cyclohexenes bearing quaternary carbon centers. Rhodium(I) and a new SDP ligand promote chemoselective formation of a cyclohex-3-enecarbaldehyde motif that is inaccessible by the Diels–Alder cycloaddition. Various α,α-bisallylaldehydes rearrange to generate six-membered rings by a mechanism triggered by aldehyde C–H bond activation. Mechanistic studies suggest a pathway involving regioselective carbometalation and endocyclic β-hydride elimination.
General Catalyst Control of the Monoisomerization of 1-Alkenes to trans-2-Alkenes

After searching for the proper catalyst, the dual challenges of controlling the position of the double bond, and cis/trans-selectivity in isomerization of terminal alkenes to their 2-isomers are finally met in a general sense by mixtures of (C5Me5)Ru complexes 1 and 3 featuring a bifunctional phosphine. Typically, catalyst loadings of 1 mol % of 1 and 3 can be employed for the production of (E)-2-alkenes at 40–70 °C. Catalyst comprising 1 and 3 avoids more than any other known example the thermodynamic equilibration of alkene isomers, as the trans-2-alkenes of both nonfunctionalized and functionalized alkenes are generated.
How Useful Is Photo-Realistic Rendering for Visual Learning?

Data seems cheap to get, and in many ways it is, but the process of creating a high quality labeled dataset from a mass of data is time-consuming and expensive.
Transition from Linear to Nonlinear Viscoelastic Behavior. III. Linearity below and above TG

Abstract This work correlates diverse data from the literature in an effort to mark the stress and strain limits of linear viscoelasticity theory below and above Tg for amorphous polymers. The data on limits of linear behavior are based on deviation of 3 % from theory and extend from Tg -150[ddot]C to Tg +150[ddot]C. It is shown that, whereas the stress limit of linear behavior drops as Tg is crossed from below, the strain limit increases from ca. 1 to ca. 100 % over the same temperature region.
A REVIEW OF DYNAMIC VEHICLE HOLDINGS MODELS AND A PROPOSAL FOR A VEHICLE TRANSACTIONS MODEL

Proceedings of the Japanese Society of Civil Engineers, Number 440/IV-16 Household vehicle holdings observed at a time point embody many decisions made by the household over a period of time. The set of vehicles the household holds, or household vehicle fleet, is not acquired instantaneously; it is the result of a series of transaction decisions to acquire, replace, or dispose of household vehicles. Each of these decisions is conditioned on the current vehicle holdings, and reflects the long-term planning effort of the household. Most household vehicle holdings models are either cross-sectional, using data obtained at one point in time, or pseudo-dynamic, using repeated cross-sectional data or aggregate time-series observations obtained from various sources. Both classes of models are subject to certain limitations. Application of cross-sectional models to forecasting implies longitudinal extrapolation of cross-sectional variations which is valid only under very restrictive conditions. For example, questions have been raised whether cross-sectional elasticities estimated from these models are identical to longitudinal elasticities that are associated with changes in behavior. Cross-sectional models' ability to accurately represent household behavior under changing income, fuel prices, traffic congestion, etc., should be critically re-examined. Aggregate time-series-models, on the other hand, are often incapable of capturing causal relationships governing the behavior of individual behavioral units, thus tend to be limited in their accuracy and policy sensitivity.
Characterization of the local charge environment of a single quantum dot via resonance fluorescence

Resonant photoluminescence excitation spectra and autocorrelation measurements indicate that a quantum dot experiences discrete spectral shifts and continuous drifts due to fluctuations in the local charge environment. Specifically, the fluctuations of few nearby charge traps.
Constitutive Equations for Viscoelastic Fluids for Short Deformation Periods and for Rapidly Changing Flows: Significance of the Deborah Number

The proper forms and asymptotic characteristics of constitutive equations which may be useful for the description of viscoelastic fluids in flow fields of engineering interest are considered. It is seen that the Deborah number emerges as a natural ordering parameter which determines, on the one hand, whether simple approximations explicit in stress may suffice to describe the fluid properties or, on the other hand, whether implicit or integral equations are required. Methods of scale-up are discussed.
Tomographic Full Waveform Inversion (TFWI) by Successive Linearizations and Scale Separations

Tomographic Full waveform inversion (TFWI) provides a framework to invert the seismic data that is immune to cycle-skipping problems by extending the velocity model. However, this extension makes the propagation considerably more expensive because each multiplication by velocity becomes a convolution. We provide an alternative formulation which computes the backscattering and the forward scattering components of the gradient separately. The inversion setup includes two steps that maintain the high resolution results of TFWI. First, the linearized residual are updated in a nested inversion scheme. Second, the two components of the gradient are first mixed and then separated based on a Fourier domain scale separation to allow for a fully simultaneous inversion of model scales.
Prolegomena to a theory of mechanized formal reasoning

This is an informal description of my ideas about using formal logic as a tool for reasoning systems using computers. The theoretical ideas are illustrated by the features of FOL. All of the examples presented have actually run using the FOL system.
The Treatment of Skeletal Facial Deformities using Virtual 3-D Planning and a Surgery First Protocol

a smoother intraoperative experience with adjunctive resources such as cutting guides, jigs to assist in segment orientation and a template for bone grafting contours. The accuracy of virtual surgical planning with 30 patients using an intraoral fiducial and digital transfer of DICOM data (Charlotte Method Medical Modeling) will be reviewed (submitted to JOMS 11/2013). The efficiency offered by computer aided surgical simulation can return hours to the surgeon day through amore streamlined presurgical workup, smoother intraoperative experience, confidence in the surgical accuracy that can in turn be devoted to other professional or personal obligations.
From ab initio calculations to multiscale design of Si/C core-shell particles for Li-ion anodes.

The design of novel Si-enhanced nanocomposite electrodes that will successfully mitigate mechanical and chemical degradation is becoming increasingly important for next generation Li-ion batteries. Recently Si/C hollow core–shell nanoparticles were proposed as a promising anode architecture, which can successfully sustain thousands of cycles with high Coulombic efficiency. As the structural integrity and functionality of these heterogeneous Si materials depend on the strength and fracture energy of the active materials, an in-depth understanding of the interface and their intrinsic mechanical properties, such as fracture strength and debonding, becomes critical for the successful design of such and similar composites. Here, we first perform ab initio simulations to calculate these properties for lithiated a-Si/a-C interface structures and combine these results with linear elasticity expressions to model conditions that will avert fracture and debonding in these heterostructures. We find that the a-Si/a-C ...
Toward Molecular Catalysts by Computer

ConspectusRational design of molecular catalysts requires a systematic approach to designing ligands with specific functionality and precisely tailored electronic and steric properties. It then becomes possible to devise computer protocols to design catalysts by computer. In this Account, we first review how thermodynamic properties such as redox potentials (E°), acidity constants (pKa), and hydride donor abilities (ΔGH–) form the basis for a framework for the systematic design of molecular catalysts for reactions that are critical for a secure energy future. We illustrate this for hydrogen evolution and oxidation, oxygen reduction, and CO conversion, and we give references to other instances where it has been successfully applied. The framework is amenable to quantum-chemical calculations and conducive to predictions by computer. We review how density functional theory allows the determination and prediction of these thermodynamic properties within an accuracy relevant to experimentalists (∼0.06 eV for r...
Customer Satisfaction of Power Distribution Companies

Electricity is one of the basic needs apart from food, clothing, and housing. Coverage, continuity, and sustainability are three dimensions of supply that need to be focused by distribution companies. It was observed that distribution companies like Scottish Power in UK, Vattenfall in Europe, and Tata Power in India have undertaken serious steps in improving customer satisfaction. This article compares efforts put by power utility companies in developed and underdeveloped countries, and highlights future needs and challenges faced with solutions for power sector in India.
Using an online homework management system in tax accounting: does it advance learning?

This paper presents effects of an online homework management system OHMS in a tax accounting course. An examination is made of student performance and perceptions with and without use of an OHMS in an undergraduate upper-level tax accounting course. Students indicated that they perceived their learning performance was enhanced due to use of the OHMS; however, this perception was not supported by the actual performance results. Empirical evidence indicates that an OHMS does not increase student learning performance. At the same time, an OHMS does provide an objective measurement of homework performance along with instant and convenient feedback to students.