cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolutionary Effects of Irradiation in Cataclysmic Variables

The orbital evolution of cataclysmic variables in which the companion is illuminated by a fraction of the accretion luminosity consists of irradiation-driven limit cycles on thermal timescales, superimposed on secular evolution toward shorter periods due to systemic angular momentum losses. We show that positive orbital period derivatives during bright phases are a natural consequence of the expansion of the companion during high mass transfer phases in the limit cycle. The irradiation instability may be enhanced by consequential angular momentum losses accompanying the limit cycle. We investigate the secular evolution of cataclysmic binaries under the combined effects of irradiation and and show that faster-than-secular orbital period excursions of either sign may occur. We discuss whether the mass transfer fluctuations that occur during these cycles can account for the observed dispersion in disk luminosities or estimated accretion rates at a given orbital period. If indeed irradiation-driven and CAML-assisted mass transfer fluctuations on timescales faster than secular occur, as discussed in this paper, then we may be able to predict the relative abundances of the different types of cataclysmic variable at a given orbital period. For example this mechanism may explain the relative paucity of dwarf novae with respect to nova-like variables with peridods between 3 and 4 hr.
Nanoparticle-based biologic mimetics.

Centered on solid chemistry foundations, biology and materials science have reached a crossroad where bottom-up designs of new biologically important nanomaterials are a reality. The topics discussed here present the interdisciplinary field of creating biological mimics. Specifically, this discussion focuses on mimics that are developed using various types of metal nanoparticles (particularly gold) through facile synthetic methods. These methods conjugate biologically relevant molecules, e.g., small molecules, peptides, proteins, and carbohydrates, in conformationally favorable orientations on the particle surface. These new products provide stable, safe, and effective substitutes for working with potentially hazardous biologicals for applications such as drug targeting, immunological studies, biosensor development, and biocatalysis. Many standard bioanalytical techniques can be used to characterize and validate the efficacy of these new materials, including quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and enzyme-linked immunosorbent assay (ELISA). Metal nanoparticle–based biomimetics continue to be developed as potential replacements for the native biomolecule in applications of immunoassays and catalysis. Copyright © 2008 John Wiley & Sons, Inc. For further resources related to this article, please visit the WIREs website.
Deactivation of V2O5/TiO2 catalysts during the oxidation of meta-dichlorobenzene in the presence of methyl-naphthalene

Abstract Kinetic and in situ infrared spectroscopic studies were conducted during the investigation of the effect of methyl-naphthalene (mNpht) on the oxidation of meta-dichlorobenzene (m-DCB) over a 3.6 wt.% V2O5/TiO2 catalyst. A gradual decrease in the conversion of m-DCB was observed with time on stream in the presence of mNpht. This deactivation was more pronounced at lower temperatures and higher mNpht inlet concentrations. The results of in situ FTIR studies indicate the accumulation of carbonaceous species on the catalyst surface. The catalyst can regain its activity towards the oxidation of m-DCB upon removal of mNpht from the reaction gas mixture. The rate of regeneration depends on temperature and the amount of carbon accumulated on the catalyst surface.
High-resolution solar imaging with a photon sieve

Dissipation in the solar corona is expected to occur in extremely thin current sheets of order 1-100 km. Emission from these current sheets should be visible in coronal EUV emission lines. However, this spatial scale is far below the resolution of existing imaging instruments. Conventional optics cannot be easily manufactured with sufficient surface figure accuracy to obtain the required < 0.1 arcsec resolution. A photon sieve, a diffractive imaging element similar to a Fresnel zone plate, can be manufactured to provide a few 0.001 arcsec resolution, with much more relaxed tolerances than conventional imaging technology. A simple design for a sounding rocket payload is presented that obtains 80 mas (0.080 arcsec) imaging with a 100 mm diameter photon sieve to image Fe XIV 334 and Fe XVI 335. These images will not only show the structure of the corona at a resolution never before obtained, they will also allow a study of the temperature structure in the dissipation region.
On maximum flows in polyhedral domains

Abstract We introduce a new class of problems concerned with the computation of maximum flows through two-dimensional polyhedral domains. Given a polyhedral space (e.g., a simple polygon with holes), we want to find the maximum “flow” from a source edge to a sink edge. Flow is defined to be a divergence-free vector field on the interior of the domain, and capacity constraints are specified by giving the maximum magnitude of the flow vector at any point. The problem is the natural extension to the continuous domain of the discrete problem of finding maximum flows through a capacitated network. For this problem, Strang proved that max flow equals min cut; we address the problem of constructing min cuts and max flows. We give polynomial-time algorithms for maximum flow from a source edge to a sink edge through a simple polygon with uniform capacity constraint (with or without holes), maximum flow through a simple polygon from many sources to many sinks, and maximum flow through weighted polygonal regions. Central to our methodology is the intimate connection between the max-flow problem and its dual, the min-cut problem. We show how the continuous Dijkstra paradigm of solving shortest paths problems corresponds to a continuous version of the uppermost path algorithm for computation of maximum flow in a planar network.
Nuclear Cusps and Cores in Early-Type Galaxies as Relics of Binary Black Hole Mergers

We present an analysis of the central cusp slopes and core parameters of early-type galaxies using a large database of surface brightness profiles obtained from Hubble Space Telescope observations. We examine the relation between the central cusp slopes, core parameters, and black hole masses in early-type galaxies, in light of two models that attempt to explain the formation of cores and density cusps via the dynamical influence of black holes. Contrary to the expectations from adiabatic-growth models, we find that the cusp slopes do not steepen with increasing black hole mass fraction. Moreover, a comparison of kinematic black hole mass measurements with the masses predicted by the adiabatic models shows that they overpredict the masses by a factor of ~3. Simulations involving binary black hole mergers predict that both the size of the core and the central mass deficit correlate with the final black hole mass. These relations are qualitatively supported by the present data.
Simultaneous measurement of twist angle and cell gap of a twisted-nematic cell by an optical method

— An optical method is presented which allows one to measure simultaneously the twist angle and cell gap of a filled twisted-nematic liquid-crystal display (TN-LCD) that has an arbitrary unknown twist angle between 0 and 360°. It can also determine the sense of handedness of the twist and the two rubbing directions of an unknown panel. Using this method, the measurement uncertainty of the cell gap is within 1% and the measurement uncertainties of the twist angle and rubbing directions are within 1°.
Geographic cluster size and firm performance

Abstract We examine whether there are increasing returns to locating in clusters—a fundamental premise of agglomeration theory. This premise is worth exploring because a) it has infrequently been studied; b) recent evidence suggests that diseconomies of agglomeration change over time and may alter the payoffs to firms located in clusters; and c) recent evidence suggests that there may be negative returns to agglomeration. We examine firm payoffs to clustering in the biotechnology industry, and consider five different measures of performance. Our results lend support to the view that there are increasing returns to cluster size, but also suggest that diseconomies of agglomeration play an increasingly important role as clusters evolve. We believe these results help in reconciling previous findings.
Absorption-Line Systems and Galaxies in Front of the Second-brightest Quasar, PHL 1811

The extraordinarily bright quasar PHL 1811, at a redshift zem = 0.192, provides an attractive opportunity to use ultraviolet absorption-line spectroscopy to study the properties of gas systems in the local universe. A short (11.3 ks), exploratory spectrum of this object was obtained by the Far Ultraviolet Spectroscopic Explorer (FUSE) with a signal-to-noise ratio of 20 per λ/20,000 resolution element over the most relevant portions of the coverage from 907 to 1185 A. This spectrum reveals seven extragalactic absorption systems, one of which is a Lyman limit system at zabs = 0.08093 with 17.5 < log N(H ) < 19.5. Three of the remaining systems have zabs values that differ by less than 0.008 from that of the Lyman limit system. The abundance of O with respect to Fe in the Lyman limit system is not much different from the solar abundance ratio. The opacity of the Lyman limit system below 990 A and the numerous features arising from Galactic H2 block a moderate fraction of important extragalactic features in the FUSE wavelength band. Nevertheless, supplementary spectra at low resolution plus a moderate-resolution, near-UV spectrum over a limited wavelength range recorded by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope helped to substantiate our identifications of systems in the FUSE spectrum. The low-resolution STIS spectrum also revealed four absorption features shortward of the quasar's Lyα emission, which we interpret as arising from additional systems showing only the Lyα feature. Spectroscopy of seven galaxies with MR -20 within approximately 2' of PHL 1811 indicated that two of them are near the redshift of the quasar and four have redshifts within 850 km s-1 of the extragalactic absorption systems. The Lyman limit system is likely associated with an L* galaxy at z = 0.0808 lying 23'' (34 h kpc) from the sight line, with absorption arising in the halo of the galaxy or in an unusually large galactic disk. It is also possible that the absorbing material may be tidal debris arising from the galaxy's interactions with a neighbor lying 88 h kpc from the sight line or more extensive intragroup or intracluster gas. Finally, in addition to prominent features at very low velocities arising from the disk of our Galaxy, the strong resonance transitions of C II and Mg II show evidence of material at v ≈ -200 km s-1; the column densities of these two species suggest that 17.7 < log N(H ) < 18.1 if the material has a solar composition.
Intermolecular [3+2] Cycloaddition of Cyclopropylamines with Olefins by Visible‐Light Photocatalysis

Solar energy is clean, abundant, and more importantly, renewable. As such, any reaction that efficiently harvests and converts solar energy into chemical energy is more important than ever as the world turns to its scientists to meet the challenge of environmental sustainability. Visible light (390–750 nm) accounts for 43% of the overall solar spectrum. However, many organic molecules are unable to absorb visible light efficiently, thereby limiting the use of visible light in organic synthesis. A possible solution to this problem involves the use of visible-light photoredox catalysts such as ruthenium[1] or iridium[2] polypyridyl complexes to channel energy from visible light into organic molecules. The groups of MacMillan,[3] Yoon,[4] Stephenson,[5] Akita,[6] and others[7] have recently published seminal works on visible-light-promoted C–C bond-formation reactions catalyzed by these complexes. Amines are often used as a sacrificial electron donor to reduce the photoexcited RuII and IrIII complexes to RuI and IrII complexes.[8] Recently, amines have been also explored as a substrate in these processes.[9] We were intrigued by the potential of using amines as both the sacrificial donor and the substrate, thus making the process more atom economical.
Growth, doping and characterization of AlxGa1 − xN thin film alloys on 6H-SiC(0001) substrates

Abstract Thin films of Al x Ga 1 − x N (0.05≤ x ≤0.96) having smooth surfaces were deposited directly on both vicinal and on-axis 6H-SiC(0001) substrates. Cross-sectional transmission electron microscopy of Al 0.13 Ga 0.87 N revealed stacking faults near the SiC/nitride alloy interface and numerous threading dislocations. Energy dispersive analysis, Auger electron spectroscopy (AES) and Rutherford backscattering were used to determine the compositions. These were paired with their respective cathodoluminescence (CL) near band-edge emission energies. A negative bowing parameter was determined. The CL emission energies were similar to the bandgap energies obtained by spectroscopic ellipsometry. Field emission AES of the initial growth of Al 0.2 Ga 0.8 N revealed an Al-rich layer near the interface. N-type (Si) doping was achieved for Al x Ga 1 − x N for 0.12≤ x ≤0.42.
The Conquest of Taxol

Much has been written about taxol, one of the newest weapons against cancer, and its producer, the Pacific Yew tree (Taxus brevifolia). In this article, the authors give a frank and behind-the-scenes account of their encounter with this well-known molecule, which they and their collaborators faced as a synthetic target. Once again total synthesis is found to offer excellent opportunities for developing new synthetic strategies and novel reactions. The team of chemists who took up this challenge emerged with valuable experience and confidence in their skills.
A simple model of optimal deterrence and incapacitation

Abstract The deterrence of crime and its reduction through incapacitation are studied in a simple multiperiod model of crime and law enforcement. Optimal imprisonment sanctions and the optimal probability of sanctions are determined. A point of emphasis is that the incapacitation of individuals is often socially desirable even when they are potentially deterrable. The reason is that successful deterrence may require a relatively high probability of sanctions and thus a relatively high enforcement expense. In contrast, incapacitation may yield benefits no matter how low the probability of sanctions is—implying that incapacitation may be superior to deterrence.
Highly enantioselective Rh-catalyzed intramolecular Alder-ene reactions for the syntheses of chiral tetrahydrofurans.

Alder±ene reactions are a powerful way to construct carbon±carbon bonds. The intramolecular version of these reactions can provide efficient routes to produce a variety of heterocyclic and carbocyclic compounds.[1] Since the thermal Alder±ene reaction requires high temperature, it has found limited applications in organic syntheses. In contrast, transition-metal-catalyzed Alder±ene reactions can be performed under mild conditions and therefore are widely applied to organic syntheses.[2] However, the enantioselective processes of metal-catalyzed Alder±ene reactions are relatively unexplored and the development of highly efficient catalysts still remains a great challenge.[3] Recently, we have developed Rhcatalyzed intramolecular Alder±ene reactions of enynes using a [{Rh(diphos)Cl}2] precursor.[4] Enantioselectivities between 65±98% ee were obtained by using 1,2-bis(phospholano)benzene (Duphos), (2R,2’R)-bis(diphenylphosphanyl)-(1R,1’R)dicyclopentane (BICP), or the related (2R,2’R)-bis(diphenylphosphinite)-(1R,1’R)-dicyclopentane (BICPO) as chiral ligands.[4a] Herein, we report a significant improvement of the catalytic system for these reactions. The new catalysts are prepared in situ by simply mixing a commercially available metal precursor and a ligand. Over 99% ee has been achieved for a number of substrates. To achieve high enantioselectivities for Rh-catalyzed Alder±ene reactions, we have screened a number of chiral phosphane ligands. The enyne 1a was chosen as a standard substrate to optimize the reaction conditions and the results are given in Table 1. In the absence of phosphane ligand, [{Rh(cod)Cl}2] was an ineffective catalytic precursor at either room temperature or 65 8C (Table 1, entries 1 and 2). However, [{Rh(nbd)Cl}2] (nbd1⁄4 norbornadiene) can be used as a catalyst precursor at 65 8C (Table 1, entry 6). Using the CnTunaphos ligands developed by our group,[5] high efficiency was observed. When rac-C4-Tunaphos was used as the ligand in the presence of [{Rh(cod)Cl}2] and AgSbF6, high conversion (100%) and a high yield (98%) were obtained at room temperature within 20 min (Table 1, entry 9). Control experiments indicated that there were big differences between this new catalytic system and the earlier protocol developed by us using [{Rh(diphosphane)Cl}2] as catalytic precursor. We previously reported that [{Rh(BINAP)Cl}2] (BINAP1⁄4 2,2’COMMUNICATIONS
Critical Behavior for 2D Uniform and Disordered Ferromagnets at Self-Dual Points

We consider certain two-dimensional systems with self-dual points including uniform and disordered q-state Potts models. For systems with continuous energy density (such as the disordered versions) it is established that the self-dual point exhibits critical behavior: Infinite susceptibility, vanishing magnetization and power law bounds for the decay of correlations.
Data-oblivious external-memory algorithms for the compaction, selection, and sorting of outsourced data

We present data-oblivious algorithms in the external-memory model for compaction, selection, and sorting. Motivation for such problems comes from clients who use outsourced data storage services and wish to mask their data access patterns. We show that compaction and selection can be done data-obliviously using O(N/B) I/Os, and sorting can be done, with a high probability of success, using O(N/B) logM/B(N/B)) I/Os.
Agent—Based Models and Human Subject Experiments ∗

This chapter examines the relationship between agent-based modeling and economic decision-making experiments with human subjects. Both approaches exploit controlled "laboratory" conditions as a means of isolating the sources of aggregate phenomena. Research findings from laboratory studies of human subject behavior have inspired studies using artificial agents in "computational laboratories" and vice versa. In certain cases, both methods have been used to examine the same phenomenon. The focus of this chapter is on the empirical validity of agent-based modeling approaches in terms of explaining data from human subject experiments. We also point out synergies between the two methodologies that have been exploited as well as promising new possibilities.
Land Inheritance Rules: Theory and Cross- Cultural Analysis

Abstract This paper develops a general theory of land inheritance rules that distinguishes between two classes of rules: those allowing a testator discretion in disposing of his land (e.g., a best-qualified rule) and those constraining his choice (e.g., primogeniture). The primary benefit of the latter is to prevent rent seeking by heirs, but the cost is that the testator cannot use information about the relative abilities of his heirs to manage the land. We also account for the impact of scale economies in land use, and discuss the impact of the presence of a land market on the form of the inheritance rule. We conclude by offering some empirical tests of the model using a cross-cultural sample of societies.
Spatial Market Integration in the Presence of Threshold Effects

A large body of research has evaluated price linkages in spatially separate markets. Much recent research has applied models appropriate for nonstationary data. Such analyses have been criticized for their ignorance of transactions costs, which may inhibit price adjustments and thus affect tests of integration. This analysis utilizes threshold autoregression and cointegration models to account for a neutral band representing transactions costs. We evaluate daily price linkages among four corn and four soybean markets in North Carolina. Nonlinear impulse response functions are used to investigate dynamic patterns of adjustments to shocks. Our results confirm the presence of thresholds and indicate strong support for market integration, though adjustments following shocks may take many days to be complete. In every case, the threshold models suggest much faster adjustments in response to deviations from equilibrium than is the case when threshold behavior is ignored. A large amount of empirical research has evaluated the extent to which spatially separate markets are integrated. Though the term is used loosely in the literature, tests of “market integration” usually consider the extent to which shocks are transmitted among spatially separate markets. The integration of markets can have important implications for price discovery and the operation of the market since persistent deviations from integration may imply riskless profit opportunities for spatial traders.
Performance limits of delay lines based on optical amplifiers

The performance of tunable buffers based on optical amplifiers and its improvement by use of gain flattening are analyzed. A simple analytical expression is obtained indicating that the gain required to attain tunable storage of N bits increases nonlinearly with N and reaches unrealistically high values for N>5. A comparison with other types of optical delay line is made.
Random pattern testability of memory control logic

This paper analyzes the random pattern testability of faults in the control logic of an embedded memory. We show how to compute exposure probabilities of these faults using mostly signal probability computations. We also show that the hardest memory control logic fault to detect is not necessarily the one with the lowest detection probability at the memory boundary.
A Universal result on central charges in the presence of double trace deformations

We study large N conformal field theories perturbed by relevant double-trace deformations. Using the auxiliary field trick, or Hubbard-Stratonovich transformation, we show that in the infrared the theory flows to another CFT. The generating functionals of planar correlators in the ultraviolet and infrared CFT’s are shown to be related by a Legendre transform. Our main result is a universal expression for the difference of the scale anomalies between the ultraviolet and infrared fixed points, which is of order 1 in the large N expansion. Our computations are entirely field theoretic, and the results are shown to agree with predictions from AdS/CFT. We also remark that a certain two-point function can be computed for all energy scales on both sides of the duality, with full agreement between the two and no scheme dependence.
Improving Group Communication Outcomes with Collaborative Software: The Impact of Group Size, Media Richness, and Social Presence

Project groups are becoming a mainstay in todays work environment. This coupled with globalization has distributed many teams. This makes communication among team members vital to project success. This study evaluates the impact of group size and social presence upon group communication. It compares key communication factors for three different social presence treatments (Face-to-Face without CS support; Face-to-Face with CS support; and distributed with CS support). In addition, it evaluates these impacts with two different group sizes. The results indicate that smaller and higher social presence groups maintain higher levels of communication than larger groups and groups with lower social presence. These results should alert project managers to the difficulty of communication between project team members in distributed global environments.
Capacity to within 3 bits for a class of Gaussian Interference Channels with a Cognitive Relay

The InterFerence Channel with a Cognitive Relay (IFC-CR) consists of a classical two-user interference channel in which the two independent messages are also non-causally known at a cognitive relay node. In this work a special class of IFC-CRs in which the sources do not create interference at the non-intended destinations is analyzed. This special model results in a channel with two non-interfering point-to-point channels whose transmission is aided by an in-band cognitive relay, which is thus referred to as the Parallel Channel with a Cognitive Relay (PC-CR). We determine the capacity of the PC-CR channel to within 3 bits/s/Hz for all channel parameters. In particular, we present several new outer bounds which we achieve to within a constant gap by proper selection of Gaussian input distributions in a simple rate-splitting and superposition coding-based inner bound. The inner and outer bounds are numerically evaluated to show that the actual gap can be far less than 3 bits/s/Hz.
Gravitational Perturbations of a Radiating Spacetime.

This paper discusses the problem of gravitational perturbations of radiating spacetimes. We lay out the theoretical framework for describing the interaction of external gravitational fields with a radiating spacetime. This is done by deriving the field perturbation equations for a radiating metric. The equations are then specialized to a Vaidya spacetime. For the Hiscock ansatz of a linear mass model of a radiating blackhole the equations are found separable. Further, the resulting ordinary differential equations are found to admit analytic solutions. We obtain the solutions and discuss their characteristics.
Face detection in color images

Human face detection plays an important role in applications such as video surveillance, human computer interface, face recognition, and face image database management. We propose a face detection algorithm for color images in the presence of varying lighting conditions as well as complex backgrounds. Based on a novel lighting compensation technique and a nonlinear color transformation, our method detects skin regions over the entire image and then generates face candidates based on the spatial arrangement of these skin patches. The algorithm constructs eye, mouth, and boundary maps for verifying each face candidate. Experimental results demonstrate successful face detection over a wide range of facial variations in color, position, scale, orientation, 3D pose, and expression in images from several photo collections (both indoors and outdoors).
Energy requirements of infants.

ObjectiveTo estimate the energy requirements of infants from total energy expenditure and energy deposition during growth.DesignEnergy requirements during infancy were estimated from total energy expenditure measured by the doubly labelled water method and energy deposition based on measured protein and fat gains.SettingDatabase on the total energy expenditure and energy deposition of infants was compiled from available studies conducted in China, Chile, Gambia, Mexico, Netherlands, UK, and USA.SubjectsHealthy, term infants.ResultsTotal energy requirements (kJ day−1) increased with age and were higher in boys than girls due to differences in weight. Energy requirements decreased from 473 kJ kg−1 per day for boys and 447 kJ kg−1 per day for girls at 1 month of age to 337 kJ kg−1 per day for boys and 341 kJ kg−1 per day for girls at 6 months of age, and thereafter tended to plateau. Energy deposition as a percentage of total energy requirements decreased from 40% at 1 month to 3% at 12 months of age. These estimates are 10–32% lower than the 1985 FAO/WHO/UNU recommendations which were based on observed energy intakes of infants.ConclusionsRecommendations for the energy intake of infants should be revised based on new estimates of total energy expenditure and energy deposition.
Enzyme-based logic systems for information processing

In this critical review we review enzymatic systems which involve biocatalytic reactions utilized for information processing (biocomputing). Extensive ongoing research in biocomputing, mimicking Boolean logic gates has been motivated by potential applications in biotechnology and medicine. Furthermore, novel sensor concepts have been contemplated with multiple inputs processed biochemically before the final output is coupled to transducing “smart-material” electrodes and other systems. These applications have warranted recent emphasis on networking of biocomputing gates. First few-gate networks have been experimentally realized, including coupling, for instance, to signal-responsive electrodes for signal readout. In order to achieve scalable, stable network design and functioning, considerations of noise propagation and control have been initiated as a new research direction. Optimization of single enzyme-based gates for avoiding analog noise amplification has been explored, as were certain network-optimization concepts. We review and exemplify these developments, as well as offer an outlook for possible future research foci. The latter include design and uses of non-Boolean network elements, e.g., filters, as well as other developments motivated by potential novel sensor and biotechnology applications (136 references).
Characteristics and reliability of fast-flow, snap-cure, and reworkable underfills for solder bumped flip chip on low-cost substrates

In this study, the fast-flow, fast-cure, and reworkable underfill materials from two different vendors are considered. Emphasis is placed on the determination of the curing conditions such as temperature and time, and the material properties such as the thermal coefficient of expansion (TCE), storage modulus, loss modulus, glass transition temperature (T/sub g/), and moisture uptake of these underfill materials. Also, the key elements and steps of the solder-bumped flip-chips on low-cost substrates with these underfill materials such as the chip, printed circuit board (PCB), flip chip assembly, and underfill application are presented. Furthermore, the key elements and steps of the rework of the solder-bumped flip-chip assemblies with these underfill materials such as chip removal, chip reballing, substrate cleaning, and new chip placement are discussed. Finally, shear test results of the assemblies with one-time rework and no-rework are presented.
Solid‐State Photodimerization of 1,2‐Bis(5′‐pyrimidyl)ethene

Abstract The photodimerization of 1,2‐bis(5′‐pyrimidyl)ethene in the solid state is reported. Photolysis of the crystalline solid formed on self‐assembly of 1,2‐bis(5′‐pyrimidyl)ethene and C‐methylcalix[4]resorcinarene and photolysis of the solid recystallized from dichloromethane yielded cis‐anti‐cis‐1,2,3,4‐tetrakis(5′‐pyrimidyl)cyclobutane as the only product. Single‐crystal X‐ray analysis of each of these solids confirms that the alkenes are π‐stacked, colinear, and separated by less than 4.2 A.
The Population of Tiny Near-Earth Objects Observed by NEOWISE

Only a very small fraction of the asteroid population at size scales comparable to the object that exploded over Chelyabinsk, Russia has been discovered to date, and physical properties are poorly characterized. We present previously unreported detections of 105 close approaching near-Earth objects (NEOs) by the Wide-field Infrared Survey Explorer (WISE) mission's NEOWISE project. These infrared observations constrain physical properties such as diameter and albedo for these objects, many of which are found to be smaller than 100 m. Because these objects are intrinsically faint, they were detected by WISE during very close approaches to the Earth, often at large apparent on-sky velocities. We observe a trend of increasing albedo with decreasing size, but as this sample of NEOs was discovered by visible light surveys, it is likely that selection biases against finding small, dark NEOs influence this finding.
Transfer of Chirality in the Rhodium-Catalyzed Intramolecular [5+2] Cycloaddition of 3-Acyloxy-1,4-enynes (ACEs) and Alkynes: Synthesis of Enantioenriched Bicyclo[5.3.0]decatrienes†

Chiral Bicyclic Bicyclo[5.3.0]decatrienes were prepared enantioselectively for the first time from readily available chiral 3-acyloxy-1,4-enynes (ACEs). The chirality of the allylic/propargylic esters in ACEs could be transferred with high efficiency to the bicyclic products in most cases. The experimentally observed overall inversion of stereochemistry confirmed the prediction from previous computational studies.
Two-phase equilibrium and molecular hydrogen formation in damped Lyman-alpha systems

Molecular hydrogen is quite underabundant in damped Lyman- systems at high redshift, when com- pared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman- systems is warm like the nearby neutral intercloud medium, rather than cool, as in the clouds which give rise to most H I absorption in the Milky Way. Other lines of evidence suggest that the gas in damped Lyman- systems { in whole or part { is actually cool; spectroscopy of neutral and ionized carbon, discussed here, shows that the damped Lyman- systems observed at lower redshift z 2:8 are warm (though not devoid of H2). To interpret the observations of carbon and hydrogen we constructed detailed numerical models of H2 formation under the conditions of two-phase thermal equilibrium, like those which account for conditions near the Sun, but with varying metallicity, dust-gas ratio, etc. We nd that the low metallicity of damped Lyman- systems is enough to suppress H2 formation by many orders of magnitude even in cool diuse clouds, as long as the ambient optical/uv radiation eld is not too small. For very low metallicity and under the most diuse conditions, H2 formation will be dominated by slow gas-phase processes not involving grains, and a minimum molecular fraction in the range 10 8 10 7 is expected.
Ex post stockholder unanimity: A Complete and Simplified Treatment

Abstract This paper generalizes the Ekern-Wilson (1974) analysis of ex post, non-competitive markets, stockholder unanimity. Most of the sufficient conditions are relaxed, and necessary conditions are provided as well. The precise roles of ‘spanning’ and ‘small production change’ are identified. Neither condition is necessary even though no particular restrictions are imposed on individuals preferences/beliefs. The cases of negative and positive unanimity are shown to be asymmetric. The analysis relies solely on elementary methods of revealed preference.
Fourier duality for fractal measures with affine scales

For a family of fractal measures, wend an explicit Fourier d uality. The measures in the pair have compact support in R d , and they both have the same matrix scaling. But the two use dierent translation vectors, one by a subset B in R d , and the other by a related subset L. Among other things, we show that there is then a pair of innite disc rete sets Γ(L) and Γ(B) in R d such that the Γ(L)-Fourier exponentials are orthogonal in L 2 (µB), and the Γ(B)-Fourier exponentials are orthogonal in L 2 (µL). These sets of orthogonal \frequencies" are typically lac unary, and they will be obtained by scaling in the large. The nature of our duality is explored below both in higher dimensions and for examples on the real line. Our duality pairs do not always yield orthonormal Fourier bases in the respective L 2 (µ)-Hilbert spaces, but depending on the geometry of certainnite orbit s, we show that they do in some cases. We further show that there are new and surprising scaling symmetries of relevance for the ergodic theory of these ane fractal measures.
Understanding and Improving Platinum Anticancer Drugs – Phenanthriplatin

Approximately half of all patients who receive anticancer chemotherapy are treated with a platinum drug. Despite the widespread use of these drugs, the only cure that can be claimed is that of testicular cancer following cisplatin treatment. This article reviews some of our recent work on phenanthriplatin, a cisplatin derivative in which a chloride ion is replaced by phenanthridine, and one of its analogues, the previously reported pyriplatin. These cationic complexes form monofunctional adducts on DNA that do not significantly distort the duplex yet efficiently block transcription. Cell-based assays reveal altered cellular uptake properties and a cancer cell-killing profile different from those of established platinum drugs. Mechanistic work, including a crystal structure analysis of platinum-modified DNA in the active site of RNA polymerase II, is discussed.
FG Sagittae: The s-Process Episode

The spectrum of the supergiant FG Sge has been studied from a series of high dispersion 120-in. coude spectrograms obtained during the interval 1969–72, thus continuing the work of Herbig and Boyarchuk (1968). The star, of effective temperature about 6500K in 1972, is cooling at the rate of 250K yr−1; it is known to have ejected a still visible planetary nebula some 6000 years ago (Flannery and Herbig, 1973). Abnormally strong absorption lines of Y ii, Zr ii, Ce ii La ii and other s-process species began to appear in the spectrum of the central star some time after 1967 and have progressively strengthened. Present abundances per gram of these elements are about 25 times the solar value. There is little doubt that the atmosphere of the star has been enriched in these elements during the past seven years, but the rate of enrichment now appears to be slowing down.
Mingling Decision Making Metaphors

Organizational decisions provide conceptual playing fields wherein scientists adhering to rival theories based on different metaphors skirmish in-decisively. Organizational decisions, however, are also empirical arenas wherein practitioners espousing discordant theories-in-use reconcile their differences pragmatically. Practitioners' decision-making metaphors encountered while studying capital budgeting suggest how disjoint perspectives are assimilated and shifts from instrumental to symbolic actions are triggered. Implications for decision theories are discussed, and potential benefits of incorporating practitioners' knowledge into organizational science are considered.
Pairwise sequence alignment for very long sequences on GPUs

We develop novel single-GPU parallelisations of the Smith-Waterman algorithm for pairwise sequence alignment. Our algorithms, which are suitable for the alignment of a single pair of very long sequences, can be used to determine the alignment score as well as the actual alignment. Experimental results demonstrate an order of magnitude reduction in run time relative to competing GPU algorithms.
Reversible peg solitaire on graphs

The game of peg solitaire on graphs was introduced by Beeler and Hoilman in 2011. In this game, pegs are initially placed on all but one vertex of a graph G . If x y z forms a path in G and there are pegs on vertices x and y but not z , then a jump places a peg on z and removes the pegs from x and y . A graph is called solvable if, for some configuration of pegs occupying all but one vertex, some sequence of jumps leaves a single peg. We study the game of reversible peg solitaire, where there are again initially pegs on all but one vertex, but now both jumps and unjumps (the reversal of a jump) are allowed. We show that in this game all non-star graphs that contain a vertex of degree at least three are solvable, that cycles and paths on n vertices, where n is divisible by 2 or 3, are solvable, and that all other graphs are not solvable. We also classify the possible starting hole and ending peg positions for solvable graphs.
A multi-component solder self-assembled micromirror ☆

Solder self-assembled micromirrors have the advantages of rigid electrical and structural connections to the substrate as well as compact assembly mechanisms. In addition solder assembly allows a structure to be rotated to any angle desired. This work presents a design process that uses these advantages to produce a novel electrostatic micromirror that can stably rotate ±10° from its assembled position in a rotation range that does not include the plane of the substrate. The compact solder mechanism allows each of three mirror components to be assembled independently to individual angles. A lumped parameter model based on a torque balance between the electrostatic force on the mirror and the restoring torque of the torsion beams is used to create the mirror design. After fabrication and assembly the design is statically tested and compared to the predicted model performance.
Carrots and sticks for new technology: Abating greenhouse gas emissions in a heterogeneous and uncertain world

Many governments use technology incentives as an important component of their greenhouse gas abatement strategies. These “carrots” are intended to encourage the initial diffusion of new, greenhouse-gas-emissions-reducing technologies, in contrast to carbon taxes and emissions trading which provide a “stick” designed to reduce emissions by increasing the price of high-emitting technologies for all users. Technology incentives appear attractive, but their record in practice is mixed and economic theory suggests that in the absence of market failures, they are inefficient compared to taxes and trading. This study uses an agent-based model of technology diffusion and exploratory modeling, a new technique for decision-making under conditions of extreme uncertainty, to examine the conditions under which technology incentives should be a key building block of robust climate change policies. We find that a combined strategy of carbon taxes and technology incentives, as opposed to carbon taxes alone, is the best approach to greenhouse gas emissions reductions if the social benefits of early adoption sufficiently exceed the private benefits. Such social benefits can occur when economic actors have a wide variety of cost/performance preferences for new technologies and either new technologies have increasing returns to scale or potential adopters can reduce their uncertainty about the performance of new technologies by querying the experience of other adopters. We find that if decision-makers hold even modest expectations that such social benefits are significant or that the impacts of climate change will turn out to be serious then technology incentive programs may be a promising hedge against the threat of climate change.
Sketching mesh deformations

Techniques for interactive deformation of unstructured polygon meshes are of fundamental importance to a host of applications. Most traditional approaches to this problem have emphasized precise control over the deformation being made. However, they are often cumbersome and unintuitive for non-expert users.In this paper, we present an interactive system for deforming unstructured polygon meshes that is very easy to use. The user interacts with the system by sketching curves in the image plane. A single stroke can define a free-form skeleton and the region of the model to be deformed. By sketching the desired deformation of this reference curve, the user can implicitly and intuitively control the deformation of an entire region of the surface. At the same time, the reference curve also provides a basis for controlling additional parameters, such as twist and scaling. We demonstrate that our system can be used to interactively edit a variety of unstructured mesh models with very little effort. Furthermore, we can also use our formulation of the deformation to achieve a natural interpolation between character poses, thus producing simple key framed animations.
The Relative Productivity Hypothesis of Industrialization: The American Case, 1820 to 1850

A two-sector model is used to explore the role of the agricultural sector in the process of industrialization. Our hypothesis is that areas industrialize earlier where the wages for females and children relative to those for adult males are initially low. Furthermore, the lower this relative productivity of females and children in the pre-industrial economy, the proportionately more will their relative wages increase, and the higher will be the ratio of manufactured to agricultural goods. The model is used to interpret the conditions that fostered the rapid industrialization of the American Northeast, but not the South, from 1820 to 1850.
LOOP VARIABLE INEQUALITIES IN GRAVITY AND GAUGE THEORY

The author points out an incompleteness in formations of gravitational and gauge theories that use traces of holonomies around closed curves as their basic variables. It is shown that in general such loop variables have to satisfy certain inequalities if they are to give a description equivalent to the usual one in terms of local gauge potentials.
Rates and Delay Times of Type Ia Supernovae

We analyze the evolution of binary stars to calculate synthetic rates and delay times of the most promising Type Ia Supernovae (SNe Ia) progenitors. We present and discuss evolutionary scenarios in which a white dwarf (WD) reaches the Chandrasekhar mass and potentially explodes in a SNe Ia. We consider Double Degenerate (DDS; merger of two WDs), Single Degenerate (SDS; WD accreting from H-rich companion), and AM Canum Venaticorum (AM CVn; WD accreting from He-rich companion) scenarios. The results are presented for two different star formation histories: burst (elliptical-like galaxies) and continuous (spiral-like galaxies). It is found that delay times for the DDS in our standard model (with common envelope efficiency {alpha}{sub CE} = 1) follow a power-law distribution. For the SDS we note a wide range of delay times, while AM CVn progenitors produce a short burst of SNe Ia at early times. The DDS median delay time falls between {approx}0.5 and 1 Gyr; the SDS between {approx}2 and 3 Gyr; and the AM CVn between {approx}0.8 and 0.6 Gyr depending on the assumed {alpha}{sub CE}. For a Milky-Way-like (MW-like) galaxy, we estimate the rates of SNe Ia arising from different progenitors as: {approx}10{sup -4} yr{sup -1} for the SDSmore » and AM CVn, and {approx}10{sup -3} yr{sup -1} for the DDS. We point out that only the rates for two merging carbon-oxygen WDs, the only systems found in the DDS, are consistent with the observed rates for typical MW-like spirals. We also note that DDS progenitors are the dominant population in elliptical galaxies. The fact that the delay time distribution for the DDS follows a power law implies more SNe Ia (per unit mass) in young rather than in aged populations. Our results do not exclude other scenarios, but strongly indicate that the DDS is the dominant channel generating SNe Ia in spiral galaxies, at least in the framework of our adopted evolutionary models. Since it is believed that WD mergers cannot produce a thermonuclear explosion given the current understanding of accreting WDs, either the evolutionary calculations along with accretion physics are incorrect, or the explosion calculations are inaccurate and need to be revisited.« less
A Framework for Infusing Authentic Data Experiences Within Statistics Courses

Working with complex data is one of the important updates to the 2014 ASA Curriculum Guidelines for Undergraduate Programs in Statistical Science. Infusing “authentic data experiences” within courses allow students opportunities to learn and practice data skills as they prepare a dataset for analysis. While more modest in scope than a senior-level culminating experience, authentic data experiences provide an opportunity to demonstrate connections between data skills and statistical skills. The result is more practice of data skills for undergraduate statisticians.[Received November 2014. Revised July 2015.]
ON THE SIZE DISTRIBUTION OF MACROECONOMIC DISASTERS

confidence interval of 2 to 4. The results are robust to uncertainty about the values of the disaster probability and the equity premium, and can accommodate seemingly paradoxical situations in which the equity premium may appear to be infinite.