cssi/SciSciGPT-SciSciNet huggingface dataset:
Quinone-Catalyzed Selective Oxidation of Organic Molecules

Quinones are common stoichiometric reagents in organic chemistry. Para-quinones with high reduction potentials, such as DDQ and chloranil, are widely used and typically promote hydride abstraction. In recent years, many catalytic applications of these methods have been achieved by using transition metals, electrochemistry, or O2 to regenerate the oxidized quinone in situ. Complementary studies have led to the development of a different class of quinones that resemble the ortho-quinone cofactors in copper amine oxidases and mediate the efficient and selective aerobic and/or electrochemical dehydrogenation of amines. The latter reactions typically proceed by electrophilic transamination and/or addition-elimination reaction mechanisms, rather than hydride abstraction pathways. The collective observations show that the quinone structure has a significant influence on the reaction mechanism and has important implications for the development of new quinone reagents and quinone-catalyzed transformations.
Periodic Accretion from a Circumbinary Disk in the Young Binary UZ Tau E

Close pre-main-sequence binary stars are expected to clear central holes in their protoplanetary disks, but the extent to which material can flow from the circumbinary disk across the gap onto the individual circumstellar disks has been unclear. In binaries with eccentric orbits, periodic perturbation of the outer disk is predicted to induce mass flow across the gap, resulting in accretion that varies with the binary period. This accretion may manifest itself observationally as periodic changes in luminosity. Here we present a search for such periodic accretion in the pre-main-sequence spectroscopic binary UZ Tau E. We present BVRI photometry spanning 3 years; we find that the brightness of UZ Tau E is clearly periodic, with a best-fit period of 19.16 ± 0.04 days. This is consistent with the spectroscopic binary period of 19.13 days, refined here from analysis of new and existing radial velocity data. The brightness of UZ Tau E shows significant random variability, but the overall periodic pattern is a broad peak in enhanced brightness, spanning more than half the binary orbital period. The variability of the Hα line is not as clearly periodic, but given the sparseness of the data, some periodic component is not ruled out. The photometric variations are in good agreement with predictions from simulations of binaries with orbital parameters similar to those of UZ Tau E, suggesting that periodic accretion does occur from circumbinary disks, replenishing the inner circumstellar disks and possibly extending the timescale over which they might form planets.
Highly Enantioselective Inverse-Electron-Demand Hetero-Diels–Alder Reactions of α,β-Unsaturated Aldehydes†

Simple, α,β-unsaturated aldehydes are excellent substrates in the hetero-Diels-Alder reaction with inverse electron demand, catalyzed by the Cr(III)-Schiff base complex I in the presence of 4-Ǻ molecular sieves and without solvent. The resulting dihydropyrans are obtained with high enantio- (89-98% ee) and diastereoselectivity (> 95% de) and in good yields (40-95%).
Atherosclerotic plaque characterization by spatial and temporal speckle pattern analysis.

Improved methods are needed to identify the vulnerable coronary plaques responsible for acute myocardial infraction or sudden cardiac death. We describe a method for characterizing the structure and biomechanical properties of atherosclerotic plaques based on speckle pattern fluctuations. Near-field speckle images were acquired from five human aortic specimens ex vivo. The speckle decorrelation time constant varied significantly for vulnerable aortic plaques τ=40 ms versus stable plaques τ=400 ms and normal aorta τ=500 ms. These initial results indicate that different atherosclerotic plaque types may be distinguished by analysis of temporal and spatial speckle pattern fluctuations.
A three-dimensional beam profile monitor based on residual gas ionization

A three-dimensional beam profile monitor based on tracking the ionization of the residual gas molecules in the evacuated beam pipe is described. Tracking in position and time of the ions and electrons produced in the ionization enables simultaneous position sampling in three dimensions. Special features which make it possible to sample very low beam currents were employed.
Low-cost, single-mode diode-pumped Cr:Colquiriite lasers

We present three Cr3+:Colquiriite lasers as low-cost alternatives to Ti:Sapphire laser technology. Single-mode laser diodes, which cost only $150 each, were used as pump sources. In cw operation, with ~520 mW of absorbed pump power, up to 257, 269 and 266 mW of output power and slope efficiencies of 53%, 62% and 54% were demonstrated for Cr:LiSAF, Cr:LiSGaF and Cr:LiCAF, respectively. Record cw tuning ranges from 782 to 1042 nm for Cr:LiSAF, 777 to 977 nm for Cr:LiSGaF, and 754 to 871 nm for Cr:LiCAF were demonstrated. In cw mode-locking experiments using semiconductor saturable absorber mirrors at 800 and 850 nm, Cr:Colquiriite lasers produced ~50–100 fs pulses with ~1-2.5 nJ pulse energies at ~100 MHz repetition rate. Electrical-to-optical conversion efficiencies of 8% in mode-locked operation and 12% in cw operation were achieved.
On optimal distributed decision architectures in a hypothesis testing environment

The authors consider the distributed detection problem, in which a set of decision makers (DMs) receive observations of the environment and transmit finite-values messages to other DMs according to prespecified communication protocols. A designated primary DM makes the final decision on one out of two alternative hypothesis. All DMs make decisions, in order to maximize a measure of organizational performance. The problem is to find an architecture for the organization which remains optimal for a variety of operating conditions. It is shown that even for very small organizations this problem is quite complex because the optimal architecture depends on variables external to the team, so that global conclusions on optimal organizational structures cannot be drawn. Suboptimal solutions are considered, and bounds on their performance are obtained. >
A module generator for high-speed CMOS current output digital/analog converters

A module generator (DSYN) creates optimized digital/analog converter (DAC) layouts given a set of specifications including performance constraints, a description of the implementation technology, and a set of design parameters. The generation process consists of a synthesis step followed by a layout step. During synthesis, a new constrained optimization method is coupled with combination of circuit simulation and DAC design equations. The layout step uses stretching and tiling operations on a set of primitive cells. Prototypes have been demonstrated for an 8-b, 100-MS/s specification, driving a 37.5-ohm video load, and a static 10-b specification, driving a 4 mA full-scale output current. Both designs use a 5-V supply in a 1.2 /spl mu/m CMOS process.
Exact weight subgraphs and the k -sum conjecture

We consider the Exact-Weight-H problem of finding a (not necessarily induced) subgraph H of weight 0 in an edge-weighted graph G. We show that for every H, the complexity of this problem is strongly related to that of the infamous k-sum problem. In particular, we show that under the k-sum Conjecture, we can achieve tight upper and lower bounds for the Exact-Weight-H problem for various subgraphs H such as matching, star, path, and cycle. One interesting consequence is that improving on the O(n3) upper bound for Exact-Weight-4-path or Exact-Weight-5-path will imply improved algorithms for 3-sum, 5-sum, All-Pairs Shortest Paths and other fundamental problems. This is in sharp contrast to the minimum-weight and (unweighted) detection versions, which can be solved easily in time O(n2). We also show that a faster algorithm for any of the following three problems would yield faster algorithms for the others: 3-sum, Exact-Weight-3-matching, and Exact-Weight-3-star.
TPS development using the Microsoft .NET framework

General purpose programming languages such as ANSI-C and C++ are commonly used for test program set (TPS) development when test-specific languages fall short or where TPS developers and system integrators want to take advantage of the commercial tools available for these languages. This paper explores adding .NET languages, specifically C#, to the list of general purpose programming languages used for TPS development. The paper starts with an overview of the .NET Framework and includes a description of the support for legacy technologies. A description of common problems with non-.NET languages and how .NET languages and tools address these problems follows. Finally, the paper concludes with examples of test development in .NET.
Vandenberg Ground Support Equipment for the Space Shuttle

This paper conveys knowledge gained from the Shuttle ground support equipment (GSE) installation at Kennedy Space Center and will also serve as a ready reference for anyone involved with Vandenberg Shuttle GSE. Mechanical and electrical Vandenberg Shuttle GSE systems are discussed, along with ground testing and prelaunch flight simulation.
The Gaussian Interference Relay Channel: Improved Achievable Rates and Sum Rate Upperbounds Using a Potent Relay

We consider the Gaussian interference channel with an intermediate relay as a main building block for cooperative interference networks. On the achievability side, we consider compress-and-forward based strategies. Specifically, a generalized compress-and-forward strategy, where the destinations jointly decode the compression indices and the source messages, is shown to improve upon the compress-and-forward strategy which sequentially decodes the compression indices and source messages, and the recently proposed generalized hash-and-forward strategy. We also construct a nested lattice code based compute-and-forward relaying scheme, which outperforms other relaying schemes when the direct link is weak. In this case, it is shown that, with a relay, the interference link can be useful for decoding the source messages. Noting the need for upperbounding the capacity for this channel, we propose a new technique with which the sum rate can be bounded. In particular, the sum capacity is upperbounded by considering the channel when the relay node has abundant power and is named potent for that reason. For the Gaussian interference relay channel with potent relay, we study the strong and the weak interference regimes and establish the sum capacity, which, in turn, serve as upperbounds for the sum capacity of the GIFRC with finite relay power. Numerical results demonstrate that upperbounds are tighter than the cut-set bound, and coincide with known achievable sum rates for many scenarios of interest. Additionally, the degrees of freedom of the GIFRC are shown to be 2 when the relay has large power, achievable using compress-and-forward.
Cutting and pasting in the Torelli group

We introduce machinery to allow “cut-and-paste”-style inductive arguments in the Torelli subgroup of the mapping class group. In the past these arguments have been problematic because restricting the Torelli group to subsurfaces gives different groups depending on how the subsurfaces are embedded. We define a category TSur whose objects are surfaces together with a decoration restricting how they can be embedded into larger surfaces and whose morphisms are embeddings which respect the decoration. There is a natural “Torelli functor” on this category which extends the usual definition of the Torelli group on a closed surface. Additionally, we prove an analogue of the Birman exact sequence for the Torelli groups of surfaces with boundary and use the action of the Torelli group on the complex of curves to find generators for the Torelli group. For genus g 1 only twists about (certain) separating curves and bounding pairs are needed, while for genus gD 0 a new type of generator (a “commutator of a simply intersecting pair”) is needed. As a special case, our methods provide a new, more conceptual proof of the classical result of Birman and Powell which says that the Torelli group on a closed surface is generated by twists about separating curves and bounding pairs. 57S05; 20F05, 57M07, 57N05
A methodology for selective removal of orbital debris

Abstract Earth-orbiting objects, large enough to be tracked, have been surveyed for possible systematic debris removal. Based upon the statistical collision studies of others, it was determined that objects in orbits approximately 1000 km above the Earth's surface are at greatest collisional risk. This study has identified Russian C-1B boosters as the most important target of opportunity for debris removal. Currently, more than 100 intact boosters are orbiting the Earth with apogees between 950 km and 1050 km. Using data provided by Energia USA, specific information on the C-1B booster, in terms of rendezvous and capture strategies, has been discussed.
Assessing Golfer Performance on the PGA TOUR

The game of golf involves many different types of shots, including long tee shots (typically hit with a driver), approach shots to greens, shots from the sand, and putts on the green. Although determining the winner of a golf tournament by counting strokes is easy, assessing which factors contributed most to the victory is not. In this paper, we apply an analysis based on strokes gained, introduced previously, to assess professional golfer performance in different parts of the game [Broadie M (2008) Assessing golfer performance using Golfmetrics. Crews D, Lutz R, eds. Sci. Golf V: Proc. World Sci. Congress Golf (Energy in Motion, Inc., Mesa, AZ), 253–262]. Strokes gained is a simple and intuitive measure of each shot's contribution to a golfer's score and was implemented by the PGA TOUR to measure putting in May 2011. We apply strokes gained analysis to extensive ShotLink™ data to rank PGA TOUR golfers in various skill categories and to quantify the factors that differentiate these golfers. Long-game shots (those starting over 100 yards from the hole) explain about two-thirds of the score variability among PGA TOUR golfers. Tiger Woods is ranked first in total strokes gained, and at or near the top of PGA TOUR golfers in each of the three main categories: long game, short game, and putting. He dominates because he excels in all phases of the game, but his long game accounts for about two-thirds of his scoring advantage relative to the average of other PGA TOUR golfers (i.e., the field). We use a similar approach to rank PGA TOUR courses for their difficulty, both overall and in each part of the game. We also discuss the recent change in the groove rule for irons by the United States Golf Association. A preliminary analysis shows that it has had almost no impact on scores from the rough.
Substructure discovery using minimum description length and background knowledge

The ability to identify interesting and repetitive substructures is an essential component to discovering knowledge in structural data. We describe a new version of our SUBDUE substructure discovery system based on the minimum description length principle. The SUBDUE system discovers substructures that compress the original data and represent structural concepts in the data. By replacing previously-discovered substructures in the data, multiple passes of SUBDUE produce a hierarchical description of the structural regularities in the data. SUBDUE uses a computationally-bounded inexact graph match that identifies similar, but not identical, instances of a substructure and finds an approximate measure of closeness of two substructures when under computational constraints. In addition to the minimumdescription length principle, other background knowledge can be used by SUBDUE to guide the search towards more appropriate substructures. Experiments in a variety of domains demonstrate SUBDUE's ability to find substructures capable of compressing the original data and to discover structural concepts important to the domain.
The Role of Religion in Environmental Attitudes

Objective This article examines the role of religion in public attitudes about the environment. While some have found that various aspects of theology and religious practices are responsible for lower levels of concern about the environment, the overall evidence is inconclusive, largely because the typical sample size is insufficient to gain insight into differences between religious traditions. Methods We use ordered logistic regression to analyze data from the 2010 Cooperative Congressional Election Study, a large survey that allows us to unpack the relationships among religious affiliation, religiosity, and environmental attitudes. Results Our results show that members of Judeo-Christian traditions are less concerned about environmental protection than their nonreligious peers, and that religiosity somewhat intensifies these relationships for evangelical Protestants, Catholics, and mainline Protestants. Conclusion While the results generally support traditional arguments that religion depresses concern about the environment, they also reveal considerable variation across and within religious traditions.
Synthesis of the barbaralone nucleus via photocyclization of an alkynyl tropone

Abstract Cyclopentannulated barbaralones 5 / 6a–c are formed in fair to good yield upon irradiation of 2-alkynyl tropones 3a–c .
Multiscale Modeling and Simulation of Worm Effects on the Internet Routing Infrastructure

An unexpected consequence of recent worm attacks on the Internet was that the routing infrastructure showed evidence of increased BGP announcement churn. As worm propagation dynamics are a function of the topology of a very large-scale network, a faithful simulation model must capture salient features at a variety of resolution scales. This paper describes our efforts to model worm propagation and its affect on routers and application traffic. Using our implementations of the Scalable Simulation Framework (SSF) API, we model worm propagation, its affect on the routing infrastructure and its affect on application traffic using multiscale traffic models.
The Interaction between Nuclear Receptor Corepressor and Histone Deacetylase 3 Regulates Both Positive and Negative Thyroid Hormone Action in Vivo

Thyroid hormone (TH) plays a critical role in development, growth, and metabolism by binding to nuclear TH receptors to modulate gene expression. In the absence of TH, TH receptors repress genes that are TH-activated by recruiting the nuclear receptor corepressor (NCoR), which exists in a tight complex with histone deacetylase 3 (HDAC3). Here we explored the actions of TH in the deacetylase activating domain mutant (DADm) mouse, whose NCoR-HDAC3 interaction is genetically disrupted. Several TH-activated genes were derepressed in the liver of euthyroid and hypothyroid DADm mice, consistent with the corepressor paradigm and a critical role of the NCoR-HDAC3 interaction in basal repression. The role of corepressors in genes that are down-regulated by TH is less well understood. Remarkably, circulating TSH levels were increased in euthyroid DADm mice, and the pituitary expression of TSHalpha, a classic TH-down-regulated gene, was modestly but significantly elevated regardless of TH status. Thus, the NCoR interaction with HDAC3 modulates expression of both positively- and negatively-regulated genes by TH in vivo.
The Physical Origin of Scale-dependent Bias in Cosmological Simulations

Using a large-scale hydrodynamic simulation with heuristic criteria for galaxy formation, we investi- gate how the galaxy —eld is related to physical parameters such as the mass density and the gas tem- perature. In our —at cold dark matter model with we —nd that the relation between the galaxy ) 0 \ 0.37, and mass density —elds is a function of scale. The bias where is the variance of b(R) 4 p g (R)/p(R), p g (R) galaxy counts in spheres of radius R and p(R) is the same for mass, varies from 2.6 at 1 h~1 Mpc to 1.2 at 30 h~1 Mpc. Including the dependence of the galaxy density on local gas temperature as well as on local mass density can fully account for this scale dependence. Galaxy density depends on temperature because gas that is too hot cannot cool to form galaxies; this causes scale dependence of b(R) because local gas temperature is related to the gravitational potential and thus contains information about the large-scale density —eld. We show that temperature dependence generally causes b(R) to vary on quasi- linear and nonlinear scales, indicating that scale dependence of bias may be a generic eUect in realistic galaxy formation scenarios. We —nd that the relationship between the galaxy and mass density —elds is also a function of galaxy age. On large scales, the older galaxies are highly biased (b B 1.7) and highly correlated with the mass density —eld; younger galaxies are not biased (b B 0.8) (r 4 Sdd g T/pp g B 1.0) and are poorly correlated (r B 0.5) with the mass. We argue that linear bias is inadequate to describe the relationship between galaxies and mass. We present a more physically based prescription that better —ts our results and reproduces the scale dependence of the bias: K)N, o g /So g T \ L (o/SoT)M(1 ) T /40,000 where L \ 1.23, M \ 1.9, and N \( 0.66. Subject headings: galaxies: formationhydrodynamicslarge-scale structure of universe
Desymmetrization of Benzoic Acid in the Context of the Asymmetric Birch Reduction−Alkylation Protocol. Asymmetric Total Syntheses of (−)-Eburnamonine and (−)-Aspidospermidine

The highly diastereoselective potassium in ammonia reduction−ethylation (EtI) of the chiral 2-(trimethylsilyl)benzamide 1b to give 1,4-cyclohexadiene 3 is the key step in asymmetric syntheses of (−)-eburnamonine (4) and (−)-aspidospermidine (5). Cyclohexadiene 3 was converted to cyclohexanone 7, which provided the trimethylsilyl-substituted butyrolactone 9 utilized for the synthesis of 4 and butyrolactone 13 required for the synthesis of 5. The preparation of 9 depended upon the completely regioselective silicon-directed Baeyer−Villiger oxidation 7 → 8; Baeyer−Villiger oxidation of the cyclohexenone 10 also was regioselective to give the desired enol lactone 11 in 92% yield. Remarkable diastereoselectivity was observed for the kinetically controlled cyclization of the acyl imminium ion derived from the vinyl-substituted carboxaldehyde 16b; treatment of 16b with 5 equiv of CF3CO2H in CH2Cl2 at −55 °C gave an 18:1 mixture of 17 and its C(3) β-epimer in 93% yield. The oxidation of alcohol 18 containing sensi...
Interpretation of the Seattle uplift, Washington, as a passive-roof duplex

We interpret seismic lines and a wide variety of other geological and geophysical data to suggest that the Seattle uplift is a passive-roof duplex. A passive-roof duplex is bounded top and bottom by thrust faults with opposite senses of vergence that form a triangle zone at the leading edge of the advancing thrust sheet. In passive-roof duplexes the roof thrust slips only when the floor thrust ruptures. The Seattle fault is a south-dipping reverse fault forming the leading edge of the Seattle uplift, a 40-km-wide fold-and-thrust belt. The recently discovered, north-dipping Tacoma reverse fault is interpreted as a back thrust on the trailing edge of the belt, making the belt doubly vergent. Floor thrusts in the Seattle and Tacoma fault zones, imaged as discontinuous reflections, are interpreted as blind faults that flatten updip into bedding plane thrusts. Shallow monoclines in both the Seattle and Tacoma basins are interpreted to overlie the leading edges of thrust-bounded wedge tips advancing into the basins. Across the Seattle uplift, seismic lines image several shallow, short-wavelength folds exhibiting Quaternary or late Quaternary growth. From reflector truncation, several north-dipping thrust faults (splay thrusts) are inferred to core these shallow folds and to splay upward from a shallow roof thrust. Some of these shallow splay thrusts ruptured to the surface in the late Holocene. Ages from offset soils in trenches across the fault scarps and from abruptly raised shorelines indicate that the splay, roof, and floor thrusts of the Seattle and Tacoma faults ruptured about 1100 years ago. Manuscript received 9 September 2003.
Envy-Free Pricing in Large Markets: Approximating Revenue and Welfare

We study the classic setting of envy-free pricing, in which a single seller chooses prices for its many items, with the goal of maximizing revenue once the items are allocated. Despite the large body of work addressing such settings, most versions of this problem have resisted good approximation factors for maximizing revenue; this is true even for the classic unit-demand case. In this article, we study envy-free pricing with unit-demand buyers, but unlike previous work we focus on large markets: ones in which the demand of each buyer is infinitesimally small compared to the size of the overall market. We assume that the buyer valuations for the items they desire have a nice (although reasonable) structure, that is, that the aggregate buyer demand has a monotone hazard rate and that the values of every buyer type come from the same support.For such large markets, our main contribution is a 1.88-approximation algorithm for maximizing revenue, showing that good pricing schemes can be computed when the number of buyers is large. We also give a (e,2)-bicriteria algorithm that simultaneously approximates both maximum revenue and welfare, thus showing that it is possible to obtain both good revenue and welfare at the same time. We further generalize our results by relaxing some of our assumptions and quantify the necessary tradeoffs between revenue and welfare in our setting. Our results are the first known approximations for large markets and crucially rely on new lower bounds, which we prove for the revenue-maximizing prices.
Leverage, Default, and Forgiveness: Lessons from the American and European Crises

This paper argues that macroeconomic stability depends less on riskless interest rates than on leverage and other measures of credit conditions, like average FICO scores of borrowers. It suggests that the leverage cycle played a central role in the recent American and European financial crisis. In the leverage cycle, asset prices and leverage rise when volatility is low and then fall as volatility rises. Sometimes asset prices fall so far below debt levels that it would be better for everybody if debt were partially forgiven. The paper recommends that central banks regularly monitor and forecast the whole credit surface, and in extreme cases intervene to regulate risky interest rates and impose partial debt forgiveness.
Strong rules for discarding predictors in lasso-type problems

Summary. We consider rules for discarding predictors in lasso regression and related problems, for computational efficiency. El Ghaoui and his colleagues have proposed ‘SAFE’ rules, based on univariate inner products between each predictor and the outcome, which guarantee that a coefficient will be 0 in the solution vector. This provides a reduction in the number of variables that need to be entered into the optimization. We propose strong rules that are very simple and yet screen out far more predictors than the SAFE rules. This great practical improvement comes at a price: the strong rules are not foolproof and can mistakenly discard active predictors, i.e. predictors that have non-zero coefficients in the solution. We therefore combine them with simple checks of the Karush–Kuhn–Tucker conditions to ensure that the exact solution to the convex problem is delivered. Of course, any (approximate) screening method can be combined with the Karush–Kuhn–Tucker conditions to ensure the exact solution; the strength of the strong rules lies in the fact that, in practice, they discard a very large number of the inactive predictors and almost never commit mistakes. We also derive conditions under which they are foolproof. Strong rules provide substantial savings in computational time for a variety of statistical optimization problems.
A SPICE Model for Multiple Coupled Microstrips and Other Transmission Lines

A general multiple coupled line model compatible with standard CAD programs, such as SPICE, is presented. It is shown that the model can be used to help analyze and design coupled line (e.g., microstrip) circuits with linear, as well as nonlinear/time varying terminations, and to help study the pulse propagation characteristics in high-speed digital circuits.
Minimizing timestamp size for completely asynchronous optimistic recovery with minimal rollback

Basing rollback recovery on optimistic message logging and replay avoids the need for synchronization between processes during failure-free execution. Some previous research has also attempted to reduce the need for synchronization during recovery, but these protocols have suffered from three problems: not eliminating all synchronization during recovery, not minimizing rollback, or providing these properties but requiring large timestamps. This paper makes two contributions: we present a new rollback recovery protocol, based on our previous work, that provides these properties (asynchronous recovery, minimal rollback) while reducing the timestamp size; and we prove that no protocol can provide these properties and have asymptotically smaller timestamps.
Energy dispersion compensation and beam loading in X-band linacs for the JLC/NLC

The shape of an RF pulse is distorted upon propagating through an X-band accelerator structure due to dispersive effects. This distortion together with beam loading introduce energy spread between 192 bunches. In order to minimize this energy spread we modify the input RF pulse shape. The pulse propagation, energy gain, and beam loading are modelled with a mode-matching computer code and a circuit model. A 2D model and a circuit model of a complete 60 cm structure, consisting of 55 cells and input and output couplers is analyzed. This structure operates with a 5/spl pi//6 phase advance per cell. Dispersive effects for this structure are more significant than for previously studied 2/spl pi//3 phase advance accelerating structures. Experimental results are compared with the theoretical model and excellent agreement is obtained for the propagation of an RF pulse through the structure.
How important is the credit channel in the transmission of monetary policy

This paper empirically tests the importance of the credit channel in the transmission of monetary policy. Three credit variables are analyzed: total bank loans, bank holdings of securities relative to loans, and the difference in the growth rate of short-term debt of small and large firms. In order to determine the marginal effect of the credit channel over the standard money channel, the significance of the credit variables is studied in a model that includes money (M2). In most cases, the credit variables play an insignificant role in the impact of monetary policy shocks on output.
The effect of genome length on ejection forces in bacteriophage lambda.

A variety of viruses tightly pack their genetic material into protein capsids that are barely large enough to enclose the genome. In particular, in bacteriophages, forces as high as 60 pN are encountered during packaging and ejection, produced by DNA bending elasticity and self-interactions. The high forces are believed to be important for the ejection process, though the extent of their involvement is not yet clear. As a result, there is a need for quantitative models and experiments that reveal the nature of the forces relevant to DNA ejection. Here, we report measurements of the ejection forces for two different mutants of bacteriophage λ, λb221cI26 and λcI60, which differ in genome length by ∼30%. As expected for a force-driven ejection mechanism, the osmotic pressure at which DNA release is completely inhibited varies with the genome length: we find inhibition pressures of 15 atm and 25 atm, for the short and long genomes, respectively, values that are in agreement with our theoretical calculations.
An analytical model for predicting the remaining battery capacity of lithium-ion batteries

Predicting the residual energy of the battery source that powers a portable electronic device is imperative in designing and applying an effective dynamic power management policy for the device. This paper starts up by showing that a 30% error in predicting the battery capacity of a lithium-ion battery can result in up to 20% performance degradation for a dynamic voltage and frequency scaling algorithm. Next, this paper presents a closed form analytical expression for predicting the remaining capacity of a lithium-ion battery. The proposed high-level model, which relies on online current and voltage measurements, correctly accounts for the temperature and cycle aging effects. The accuracy of the high-level model is validated by comparing it with DUALFOIL simulation results, demonstrating a maximum of 5% error between simulated and predicted data.
The pill and partnerships: the impact of the birth control pill on cohabitation

This paper investigates the impact on cohabitation behavior of the introduction and dispersion of the birth control pill in the USA during the 1960s and early 1970s. A theoretical model generates several predictions that are tested using the first wave of the National Survey of Families and Households. Empirically, the causal effect is identified by exploiting plausibly exogenous variation in state laws granting access to the pill to unmarried women under age 21. The evidence shows that the pill was a catalyst that increased cohabitation’s role in selecting marriage partners, but did little in the short run to promote cohabitation as a substitute for marriage.
Adaptive processing with neural network controlled resonator-banks

A structurally adaptive processing system that can dynamically change its transfer characteristics as a response to changes in the environment is described. The neural network controlled resonator-bank architecture consists of two main components, a resonator-bank filter structure and a neural network that controls the transfer characteristics of the filter. The architecture offers an attractive alternative for the approximation of time-variant nonlinear dynamics having a finite number of stable operating points with quasi-linear characteristics. >
Creation of two-dimensional Coulomb crystals of ions in oblate Paul traps for quantum simulations

We develop the theory to describe the equilibrium ion positions and phonon modes for a trapped ion quantum simulator in an oblate Paul trap that creates two-dimensional Coulomb crystals in a triangular lattice. By coupling the internal states of the ions to laser beams propagating along the symmetry axis, we study the effective Ising spin-spin interactions that are mediated via the axial phonons and are less sensitive to ion micromotion. We find that the axial mode frequencies permit the programming of Ising interactions with inverse power law spin-spin couplings that can be tuned from uniform to with DC voltages. Such a trap could allow for interesting new geometrical configurations for quantum simulations on moderately sized systems including frustrated magnetism on triangular lattices or Aharonov-Bohm effects on ion tunneling. The trap also incorporates periodic boundary conditions around loops which could be employed to examine time crystals.
Drag-Based Predictive Tracking Guidance for Mars Precision Landing

Future Mars missions require precision landing capability. An entry guidance law is developed for a lander with flying capabilities consistent with those expected for the lander in the 2001 mission. The lander flight path is controlled by bank angle adjustments. The guidance law belongs to the class of drag-based predictive tracking guidance laws which includes the entry guidance law for the Space Shuttle Orbiter. Modifications relative to the Shuttle entry guidance law are introduced to accommodate the very low lift capability and the combination of a low bandwidth attitude control system and a fixed trim angle of attack. Monte Carlo results show that even with a maximum lift-to-drag ratio of only 0.12 a specified parachute deployment latitude/longitude point can be achieved with 99% certainty to within 13.2 km under the assumed worst case dispersions. The dynamic pressure and Mach number constraints for parachute deployment are also satisfied with 99% certainty.
A compatibly differenced total energy conserving form of SPH

SUMMARY We describe a modified form of smoothed particle hydrodynamics (SPH) in which the specific thermal energy equation is based on a compatibly differenced formalism, guaranteeing exact conservation of the total energy. We compare the errors and convergence rates of the standard and compatible SPH formalisms on a variety of shock test problems with analytic answers. We find that the new compatible formalism reliably achieves the expected first-order convergence for these analytic shock tests and, in all cases, improves the accuracy of the numerical solution over the standard formalism. We also examine the performance of our new formalism on a more complicated applied problem: the diversion of an asteroid by a kinetic impactor. We find the compatible discretization demonstrates measurable improvement in the convergence of properties such as the deflection velocity in this kind of applied problem as well. Copyright © 2014 John Wiley & Sons, Ltd.
Tidal heating in Enceladus

The heating in Enceladus in an equilibrium resonant configuration with other saturnian satellites can be estimated independently of the physical properties of Enceladus. We find that equilibrium tidal heating cannot account for the heat that is observed to be coming from Enceladus. Equilibrium heating in possible past resonances likewise cannot explain prior resurfacing events.
Preparation and structures of CsGd2Cu3Se5 and CsTb2Cu3Se5

Abstract The compounds CsGd 2 Cu 3 Se 5 and CsTb 2 Cu 3 Se 5 have been obtained through the reaction of CsCl, Gd 2 Se 3 or Tb 2 Se 3 , and Cu 2 Se at 1123 K. These compounds crystallize in the RbSm 2 Ag 3 Se 5 structure type with four formula units in the space group Cmcm of the orthorhombic system in cells of dimensions at 153 K of a =4.1417(3) A, b =14.6422(9) A, c =17.4543(11) A, V =1058.49(12) A 3 for CsGd 2 Cu 3 Se 5 and a =4.1268(4) A, b =14.6204(14) A, c =17.3390(16) A, V =1046.16(17) A 3 for CsTb 2 Cu 3 Se 5 . This structure consists of ten-membered pentagonal rings in which the alkali-metal atoms are situated. The three-dimensional anionic framework is built from LnSe 6 octahedra and CuSe 4 tetrahedra.
ON FERMION ENTANGLEMENT

Under the historical definition of entanglement, namely that encountered in Einstein–Podolski–Rosen (EPR)–type experiments, it is shown that a particular Slater determinant is entangled. Thus a definition which holds that any Slater determinant is unentangled, found in the literature, is inconsistent with the historical definition. A generalization of the historical definition that embodies its meaning as quantum correlation of observables, in the spirit of the work of many others, but is much simpler and more physically transparent, is presented.
Deterministic Blind Rendezvous in Cognitive Radio Networks

Blind rendezvous is a fundamental problem in cognitive radio networks. The problem involves a collection of agents (radios) that wish to discover each other (i.e., rendezvous) in the blind setting where there is no shared infrastructure and they initially have no knowledge of each other. Time is divided into discrete slots and spectrum is divided into discrete channels, [n] = 1, 2, ..., n. Each agent may access (or hop on) a single channel in a single time slot and two agents rendezvous when they hop on the same channel in the same time slot. The goal is to design deterministic channel hopping schedules for each agent so as to guarantee rendezvous between any pair of agents with access to overlapping sets of channels. The problem has three complicating considerations: first, the agents are asymmetric, i.e., each agent Ai only has access to a particular subset Si C [n] of the channels and different agents may have access to different subsets of channels (clearly, two agents can rendezvous only if their channel subsets overlap), second, the agents are synchronous, i.e., they do not possess a common sense of absolute time, so different agents may commence their channel schedules at different times (they do have a common sense of slot duration), lastly, agents are anonymous i.e., they do not possess an identity, and hence the schedule for Ai must depend only on Si. Whether guaranteed blind rendezvous in the asynchronous model was even achievable was an open problem. In a recent breakthrough, two independent sets of authors, Shin et al. (Communications Letters, 2010) and Lin et al. (INFOCOM, 2011), gave the first constructions guaranteeing asynchronous blind rendezvous in O (n^2) and O (n^3) time, respectively. We present a substantially improved and conceptually simpler construction guaranteeing that any two agents, Ai, Aj, will rendezvous in O (|Si| |Sj| log log n) time. Our results are the first that achieve nontrivial dependence on |Si|, the sizes of the sets of available channels. This allows us, for example, to save roughly a quadratic factor over the best previous results in the important case when channel subsets have constant size. We also achieve the best possible bound of O (1) rendezvous time for the symmetric situation, previous works could do no better than O (n). Using techniques from the probabilistic method and Ramsey theory we establish that our construction is nearly optimal: we show both an ω (|Si| |Sj|) lower bound and an ω (log log n) lower bound when |Si|, |Sj| &2264; n/2.
Titanium dipyrrolylmethane derivatives: rapid intermolecular alkyne hydroamination

Alkynes are rapidly hydroaminated by primary amines using titanium dipyrrolylmethane derivatives as catalyst.
Toward real-time quantum imaging with a single pixel camera

We present a workbench for the study of real-time quantum imaging by measuring the frame-by-frame quantum noise reduction of multi-spatial-mode twin beams generated by four wave mixing in Rb vapor. Exploiting the multiple spatial modes of this squeezed light source, we utilize spatial light modulators to selectively pass macropixels of quantum correlated modes from each of the twin beams to a high quantum efficiency balanced detector. In low-light-level imaging applications, the ability to measure the quantum correlations between individual spatial modes and macropixels of spatial modes with a single pixel camera will facilitate compressive quantum imaging with sensitivity below the photon shot noise limit.
Segmentation of synthetic-aperture-radar complex data

Several algorithms used for segmenting highly speckled high-resolution synthetic-aperture-radar (SAR) complex data into spatially and radiometrically homogeneous regions are presented. The procedure is based on two models, one for the speckled complex amplitudes and the other for the regions. The first model uses the physics of the SAR imaging and processing system to characterize the statistics of speckle, while the second model uses a Markov random field to describe the statistics of the regions. Based on the combination of these two models from Bayes theory, two possible optimality criteria are considered for the segmentation of the complex data into regions. The different algorithms are implemented on a parallel optimization network. Results from both simulated and actual SAR complex data are presented for a comparison of the different alternatives and evaluation of the performance of the segmentation techniques.
Ultrathin films: magnetism on the microscopic scale

Abstract The basic concepts associated with two-dimensional ferromagnetism are illustrated from an experimentalist's viewpoint. Ultrathin epitaxial films are the prototype systems for investigating magnetism in reduced dimensions. and spin-polarized scanning electron microscopy is a powerful technique for such experiments. The topics covered include a discussion on the formation of magnetic domains in these films, the microscopic investigation of spin fluctuations, and the key role that anisotropies play in these systems.
Dial “A” for agriculture: a review of information and communication technologies for agricultural extension in developing countries

Agriculture can serve as an important engine for economic growth in developing countries, yet yields in these countries have lagged far behind those in developed countries for decades. One potential mechanism for increasing yields is the use of improved agricultural technologies, such as fertilizers, seeds, and cropping techniques. Public sector programs have attempted to overcome information-related barriers to technological adoption by providing agricultural extension services. While such programs have been widely criticized for their limited scale, sustainability, and impact, the rapid spread of mobile phone coverage in developing countries provides a unique opportunity to facilitate technological adoption via information and communication technology (ICT)-based extension programs. This article outlines the potential mechanisms through which ICT could facilitate agricultural adoption and the provision of extension services in developing countries. It then reviews existing programs using ICT for agriculture, categorized by the mechanism (voice, text, internet, and mobile money transfers) and the type of services provided. Finally, we identify potential constraints to such programs in terms of design and implementation, and conclude with some recommendations for implementing field-based research on the impact of these programs on farmers’ knowledge, technological adoption, and welfare.
Rhodium-Catalyzed Ring Expansion of Cyclopropanes to Seven-membered Rings by 1,5 C ? C Bond Migration

Selective cleavage and subsequent elaboration of carbon–carbon σ bonds into complex molecules represents a fundamental challenge in chemistry. The C–C σ bonds of cyclopropanes are activated owing to ring strain, and the ring expansion of cyclopropanes is an attractive route to other ring systems because of the well-documented stereoselective methods for cyclopropanation.[1] Indeed, ring expansion of cyclopropanes to four- or five-membered rings by 1,2 or 1,3 migration is routinely practiced in organic synthesis [Eq. (1)].[2] In contrast, ring expansion of cyclopropanes to seven-membered rings by 1,5 C–C bond migration has not been developed as a general method, in spite of the prevalence of cycloheptane skeletons in natural products and pharmaceutical agents.[3] The 1,5 migration of a cyclopropane C–C bond has been mainly studied in bicyclo-[4.1.0]heptadienes and a few other conformationally constrained bicyclic compounds under thermal conditions.[4] In fact, it was reported that simple 1,3-dienylcyclopropanes underwent 1,3 C–C bond migration to form vinylcyclopentenes in the presence of Ni or Pd catalysts.[5]
The IGY Program

This paper presents very briefly the nature and origin of the International Geophysical Year, and in more detail two areas of special interest: rocket studies of the upper atmosphere and satellite studies. It brings out the scientific basis for the satellite program and the development of U. S. interest in launching a satellite for scientific observations. The present status of the program is commented on briefly.
Adaptive stabilization of linear systems with unknown high-frequency gains

This paper presents an algorithm for adaptively controlling a single-input, single-output process admitting an n -dimensional, minimum-phase linear model of relative degree n*, with unknown parameters. A priori knowledge of the sign of the model's high frequency gain is not required, and a sufficiently rich probing signal is not needed for stabilization.