cssi/SciSciGPT-SciSciNet huggingface dataset:
Palladium-Mediated Ring Closure Reactions. Facile Syntheses of Enantiopure Bicyclic and Tricyclic Alkenones

Abstract (R)-Carvone was used as a chiral building block. Regio- and stereoselective alkylations at C6 and C2 of (R)-carvone and (R)-5-isopropyl-2-methyl-2-cyclohexenone [derived from the hydrogenation of (R)-carvone] followed by palladium-mediated ring closures afforded various enantiopure bicyclic and tricyclic alkenones. Hence, cyclization of (5S,6S)-2,6-dimethyl-6-(cis-3-iodo-2-propenyl)-5-isopropenyl-2-cyclohexenone (3) gave (4aS,5S,8aS)-1,4,4a,5,8,8a-hexahydro-5-(methoxycarbonylmethyl)-2,5,8a-trimethylnaphthalen-1-one (7) as the major product, cyclization of (5S,6S)-2,6-dimethyl-6-(cis-3-iodo-2-propenyl)-5-isopropyl-2-cyclohexenone (22) produced (1S,5R,6S)-1,5-dimethyl-6-isopropyltricyclo[3.3.1.02,8]-3-nonen-9-one (23), and cyclization of (2R,5S,6S)-2,6-dimethyl-2-(cis-3-iodo-2-propenyl)-5-isopropenyl-3-cyclohexen-1-one (25) afforded (3aR,6S,7aR)-6,7a-dimethyl-5-isopropenyl-3a,6,7,7a-tetrahydro-1H-inden-7-one (26). A 1,2-rearrangement reaction of bromide 16 gave hexahydro-1H-benzocycloheptene 17.
Space weathering of small Koronis family members

Abstract The space weathering process and its implications for the relationships between S- and Q-type asteroids and ordinary chondrite meteorites is an often debated topic in asteroid science. Q-type asteroids have been shown to display the best spectral match to ordinary chondrites (McFadden, L.A., Gaffey, M.J., McCord, T.B. [1985]. Science 229, 160–163). While the Q-types and ordinary chondrites share some spectral features with S-type asteroids, the S-types have significantly redder spectral slopes than the Q-types in visible and near-infrared wavelengths. This reddening of spectral slope is attributed to the effects of space weathering on the observed surface composition. The analysis by Binzel et al. (Binzel, R.P., Rivkin, A.S., Stuart, J.S., Harris, A.W., Bus, S.J., Burbine, T.H. [2004]. Icarus 170, 259–294) provided a missing link between the Q- and S-type bodies in near-Earth space by showing a reddening of spectral slope in objects from 0.1 to 5 km that corresponded to a transition from Q-type to S-type asteroid spectra, implying that size, and therefore surface age, is related to the relationship between S- and Q-types. The existence of Q-type asteroids in the main-belt was not confirmed until Mothe-Diniz and Nesvorny (Mothe-Diniz, T., Nesvorny, D. [2008]. Astron. Astrophys. 486, L9–L12) found them in young S-type clusters. The young age of these families suggest that the unweathered surface could date to the formation of the family. This leads to the question of whether older S-type main-belt families can contain Q-type objects and display evidence of a transition from Q- to S-type. To answer this question we have carried out a photometric survey of the Koronis family using the Kitt Peak 2.1 m telescope. This provides a unique opportunity to compare the effects of the space weathering process on potentially ordinary chondrite-like bodies within a population of identical initial conditions. We find a trend in spectral slope for objects 1–5 km that shows the transition from Q- to S-type in the main-belt. This data set will prove crucial to our understanding of the space weathering process and its relevant timescales.
Modeling of the Holding Force in an Electromagnetic Chuck

This paper addresses the modeling and prediction of the normal holding force in an electromagnetic chuck used in precision machining applications. Knowledge of the normal holding force is necessary to determine if a given chuck is capable of preventing workpiece slip during machining. First, an analytic model termed the magnetic circuit model was developed and compared with experimental holding force data. It was found that this model, although simple in form, was limited in its ability to accurately predict the holding force over the entire range of conditions investigated. The discrepancies in the model were attributed to its inability to accurately model the leakage flux and nonuniform distribution of the magnetic flux. A three-dimensional finite element model was then developed to overcome these limitations. Predictions with this model were found to be in better agreement with experiments, yielding prediction errors within 25 percent in most cases. The finite element model also provided an explanation for the observed decrease in the measured holding force at current values beyond a certain threshold.
Face numbers of generalized balanced Cohen-Macaulay complexes

A common generalization of two theorems on the face numbers of Cohen-Macaulay (CM, for short) simplicial complexes is established: the first is the theorem of Stanley (necessity) and Bjorner-Frankl-Stanley (sufficiency) that characterizes all possible face numbers of a-balanced CM complexes, while the second is the theorem of Novik (necessity) and Browder (sufficiency) that characterizes the face numbers of CM subcomplexes of the join of the boundaries of simplices.
Fiber and Integrated Optical Devices for Signal Processing

The design and performance of some signal processing devices using fiber and integrated optics are discussed. Analog-todigital (A/D) conversion, logic, and computation are among the signal processing functions which can be performed using integrated optical devices. Optical fibers can be used for signal delay and storage and for implementing transversal filters and delay-matched filters. Some other interesting possibilities make use of both fiber delay line and integrated optical elements. These include variable-length delay lines and programmable transversal filters.
New exact heavy quark sum rules

Abstract Considering nonforward scattering amplitude off the heavy quark in the Small Velocity limit two exact superconvergent sum rules are derived. The first is the sum rule for spin of the light cloud and leads to the lower bound ϱ2>3/4 for the slope of the Isgur–Wise function. It also provides the rationale for the fact that the vector heavy flavor mesons are heavier than the pseudoscalar ones. A spin-nonsinglet analogue Σ of Λ =M B −m b is introduced.
A simple catalytic method for the regioselective halogenation of arenes

This paper describes a mild palladium-catalyzed method for the regioselective chlorination, bromination, and iodination of arene C−H bonds using N-halosuccinimides as oxidants. These transformations have been applied to a wide array of substrates and can provide products that are complementary to those obtained via conventional electrophilic aromatic substitution reactions.
Cardassian expansion: dark energy density from modified Friedmann equations

Abstract The Cardassian universe is a proposed modification to the Friedmann equation in which the universe is flat, matter dominated, and accelerating. In the ordinary Friedmann equation, the right hand side is a linear function of the energy density, H 2 ∼ ρ . Here, instead, the right hand side of the Friedmann equation is a different function of the energy density, H 2 ∼ g ( ρ ). This function returns to ordinary Friedmann at early times, but drives acceleration of the universe at the current epoch. The only ingredients in this universe are matter and radiation: in particular, there is NO vacuum contribution. The new term required may arise, e.g., as a consequence of our observable universe living as a three-dimensional brane in a higher dimensional universe. A second possible interpretation of Cardassian expansion is developed, in which we treat the modified Friedman equations as due to a fluid, in which the energy density has new contributions with negative pressure (possibly due to dark matter with self-interactions). Predictions are shown for observational tests of generalized Cardassian models in future supernova surveys.
Economies With Many Commodities

We discuss the two fundamental theorems of welfare economics in the context of the Arrow-Debreu-McKenzie model with an infinite dimensional commodity space. As an application, we prove the existence of competitive equilibrium in the standard single agent growth model.
Solar Neutrinos: Theory

The solar neutrino problem can be stated simply. The observed capture rate is [1,2]: $$ Observed = \left( {2\pm 0.3} \right)SNU $$ (1) The predicted capture rate for the 37Cl experiment is [3,4]: $$ \Pr edicted = \left( {7.5\pm 2.5} \right)SNU $$ (2) [The convenient unit for discussing solar neutrinos is the product of a flux times a cross section and is: 1 SNU = 10-36 events per target particle per second. I give here preliminary values of event rates predicted by the standard solar model that have been obtained by an improved set of calculations with updated parameters. The final values will be published in reference 4.] The observational error quoted above is 1-σ(by tradition); the error I quote on the predicted rate corresponds to an effective 3-σ auncertainty, defined in [3]. The fact that the theoretical and the experimental numbers differ significantly is the solar neutrino problem. There is no generally accepted solution to the problem although neutrino oscillations in matter provides a plausible and attractive hypothesis [5,6].
HST Photometry of trans-Neptunian Objects

From July 2001 to June 2002, an HST snapshot program obtained V, R and I photometry for 72 TNOs. The TNOs were sorted by dynamical class, and Spearman rank correlation statistics were calculated for each combination of color and orbital parameter. No strong correlations were found for the combined sample of TNOs, the resonant TNOs, or the non-resonant TNOs (classical). The results presented here suggest that if correlations reported by other authors are real, they are evident only at shorter wavelengths than observed in our survey.
Gallium Oxide Nanoribbons and Nanosheets

Nanoribbons and flat nanosheets of Ga2O3 have been synthesized by evaporating GaN at high temperature with the presence of oxygen. The as-synthesized nanoribbons and nanosheets are pure, structurally uniform, single crystalline, and free from dislocations. The nanoribbons and the nanosheets all have monoclinic β-Ga2O3 structure. The flat top and bottom surfaces for both nanoribbons and nanosheets are ±(100), the side surfaces are ±(010) and ±(101) for nanoribbons and ±(010), ±(101) and ±(212) for nanosheets. The axis direction of nanoribbon growth is along either [001] or [010].
Hubble Space Telescope Observations of the HD 202628 Debris Disk

A ring-shaped debris disk around the G2V star HD 202628 (d = 24.4 pc) was imaged in scattered light at visible wavelengths using the coronagraphic mode of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The ring is inclined by approx.64deg from face-on, based on the apparent major/minor axis ratio, with the major axis aligned along PA = 130deg. It has inner and outer radii (> 50% maximum surface brightness) of 139 AU and 193 AU in the northwest ansae and 161 AU and 223 AU in the southeast ((Delta)r/r approx. = 0.4). The maximum visible radial extent is approx. 254 AU. With a mean surface brightnesses of V approx. = 24 mag arcsec.(sup -2), this is the faintest debris disk observed to date in reflected light. The center of the ring appears offset from the star by approx.28 AU (deprojected). An ellipse fit to the inner edge has an eccentricity of 0.18 and a = 158 AU. This offset, along with the relatively sharp inner edge of the ring, suggests the influence of a planetary-mass companion. There is a strong similarity with the debris ring around Fomalhaut, though HD 202628 is a more mature star with an estimated age of about 2 Gyr. We also provide surface brightness limits for nine other stars in our study with strong Spitzer excesses around which no debris disks were detected in scattered light (HD 377, HD 7590, HD 38858, HD 45184, HD 73350, HD 135599, HD 145229, HD 187897, and HD 201219).
Nonlinear birefringence of optical fibers

Abstract The nonlinear birefringence of low birefringent optical fibers has been studied experimentally. It is found that the experimental results are consistent with theoretical predictions. Earlier discrepancies between experimental results and theory could be due to the failure to compensate for the linear birefringence adequately.
Beating the recession blues: Exploring the link between family ownership, strategic marketing behavior and firm performance during recessions

This study explores whether family firms exhibit unique marketing behavior and whether their unique behavior in turn helps them outperform non-family firms during periods of economic contraction. Findings based on a sample of 275 large publicly listed U.S. firms reveal that family firms outperform non-family firms during recessions. This superior performance is partially driven by family firms' proactive marketing behavior and their relatively strong emphasis on corporate social responsibility (CSR). During recessions, while non-family firms tend to decrease their advertising intensities and rates of new product introduction (NPI), family firms are likely to maintain relatively high levels of advertising intensity and rates of NPI. Unlike non-family firms, family firms are also likely to maintain high levels of corporate social performance (CSP) during recessions. These results underscore the benefits of proactive marketing behavior and a continued emphasis on CSR during economic downturns. The authors also add to the scant family-firm literature, demonstrating the family firm to be an effective organizational form.
A hybrid 10 GHz photonic-microwave oscillator with sub-femtosecond absolute timing jitter

We demonstrate a 10 GHz hybrid oscillator comprised of a phase stabilized optical frequency comb divider and a room temperature dielectric sapphire oscillator. Characterization of the 10 GHz microwave signal via comparison of two independent hybrid oscillators yields a combined phase noise, L(f) = −100 dBc/Hz at a 1 Hz offset and L(f) 1 MHz. The associated absolute timing jitter is 0.6 fs (1 Hz to 5 GHz).
Almost uniform sampling via quantum walks

Many classical randomized algorithms (e.g. approximation algorithms for #P-complete problems) utilize the following random walk algorithm for almost uniform sampling from a state space S of cardinality N: run a symmetric ergodic Markov chain P on S for long enough to obtain a random state from within total variation distance of the uniform distribution over S. The running time of this algorithm, the so-called mixing time of P, is O(δ−1(logN+log−1)), where δ is the spectral gap of P. We present a natural quantum version of this algorithm based on repeated measurements of the quantum walk Ut = e−iPt. We show that it samples almost uniformly from S with logarithmic dependence on −1 just as the classical walk P does; previously, no such quantum walk algorithm was known. We then outline a framework for analysing its running time and formulate two plausible conjectures which together would imply that it runs in time O(δ−1/2log N log−1) when P is the standard transition matrix of a constant-degree graph. We prove each conjecture for a subclass of Cayley graphs.
Pyranone natural products as inspirations for catalytic reaction discovery and development.

ConspectusNatural products continue to provide a wealth of opportunities in the areas of chemical and therapeutic development. These structures are effective measuring sticks for the current state of chemical synthesis as a field and constantly inspire new approaches and strategies. Tetrahydropryans and tetrahydropyran-4-ones are found in numerous bioactive marine natural products and medicinal compounds. Our interest in exploring the therapeutic potential of natural products containing these motifs provided the impetus to explore new methods to access highly functionalized, chiral pyran molecules in the most direct and rapid fashion possible. This goal led to exploration and development of a Lewis acid-mediated Prins reaction between a chiral β-hydroxy-dioxinone and aldehyde to produce a pyran–dioxinone fused product that can be processed in a single pot operation to the desired tetrahydropyran-4-ones in excellent yield and stereoselectivity. Although the Prins reaction is a commonly employed approach to...
A traffic load balancing framework for software-defined radio access networks powered by hybrid energy sources

Dramatic mobile data traffic growth has spurred a dense deployment of small cell base stations (SCBSs). Small cells enhance the spectrum efficiency and thus enlarge the capacity of mobile networks. Although SCBSs consume much less power than macro BSs (MBSs) do, the overall power consumption of a large number of SCBSs is phenomenal. As the energy harvesting technology advances, base stations (BSs) can be powered by green energy to alleviate the on-grid power consumption. For mobile networks with high BS density, traffic load balancing is critical in order to exploit the capacity of SCBSs. To fully utilize harvested energy, it is desirable to incorporate the green energy utilization as a performance metric in traffic load balancing strategies. In this paper, we have proposed a traffic load balancing framework that strives a balance between network utilities, e.g., the average traffic delivery latency, and the green energy utilization. Various properties of the proposed framework have been derived. Leveraging the software-defined radio access network architecture, the proposed scheme is implemented as a virtually distributed algorithm, which significantly reduces the communication overheads between users and BSs. The simulation results show that the proposed traffic load balancing framework enables an adjustable trade-off between the on-grid power consumption and the average traffic delivery latency, and saves a considerable amount of on-grid power, e.g., 30%, at a cost of only a small increase, e.g., 8%, of the average traffic delivery latency.
The Effects of Disseminating Relative Performance Feedback in Tournament and Individual Performance Compensation Plans

ABSTRACT: This study investigates the effects of relative performance feedback and incentive compensation method on performance. We examine whether the presence and the content of relative performance feedback have different effects on performance when participants are compensated via a tournament or an individual incentive scheme. Our experimental results show a disordinal interaction between incentive scheme and feedback. Specifically, providing relative performance feedback improves the mean performance of participants compensated under an individual incentive scheme regardless of the precision or specific content of the feedback. In contrast, providing relative performance feedback deteriorates the mean performance of participants compensated under a tournament incentive scheme, but only if the feedback is sufficiently precise. Supplementary analysis suggests that this deterioration in performance is due to ineffective task strategies rather than reduced effort. We also find that in the absence of rel...
EXPERIMENTAL STUDY OF RADIATIVE TRANSPORT FROM HOT GASES SIMULATING IN COMPOSITION THE ATMOSPHERES OF MARS AND VENUS

Thermal radiation measurements of the hot gas cap of polyethylene models flying through mixtures of carbon dioxide and nitrogen that simulate mars and venus atmospheres
Three Optical Methods for Remotely Measuring Aerosol Size Distributions

Three optical probing methods for remotely measuring atmospheric aerosol size distributions are discussed and contrasted. The particular detection methods which are considered make use of monostatic lidar (laser radar), bistatic lidar, and solar radiometer sensing techniques. The theory of each of these measurement techniques is discussed briefly, and the necessary constraints which must be applied to obtain aerosol size distribution information from such measurements are pointed out. Theoretical and/or experimental results are also presented which demonstrate the utility of the three proposed probing methods.
“An ungovernable anarchy”: The United States’ response to depression and default, 1837–1848

American commentators have criticized European leaders for failing to deal firmly and swiftly with the eurozone’s sovereign debt crisis. These commentators forget the lessons of American history. The United States experienced a similar crisis following the financial panic of 1837. Eight states defaulted and political turmoil intensified, undermining stability in several states and the federal system itself. The restoration of economic and political order was a prolonged and painful process, as enraged voters confronted the costs of inaction and accepted new constraints on democratic processes. Will the European crisis play out similarly?
Estimation of promotional strategies for newer vs older drugs based on physician prescribing data

Purpose – The purpose of this paper is to use results from a comprehensive analysis of a physician‐prescribing model to draw guidelines on how to promote a new drug in the presence of competing older drugs, in a chronic therapeutic state.Design/methodology/approach – The authors use an extensive database from SDI Health, LLC, and a second data set from IMS Health. They calibrate their model using logarithmic regression methodology. The dependent variable in the model is number of new prescriptions and the explanatory variables are physician and patient characteristics, and marketing variables.Findings – The authors' estimates imply that heavy prescribers are likely to be specialists, be in solo practice, have more experience, receive more sales rep traffic, have more HMO affiliations, have a higher proportion of patients in HMOs, write more prescriptions across all therapeutic categories, see a higher number of patients, receive more free samples from the sales reps, have more rep intensity in their offic...
Creation of Universes from Nothing

If inflation is eternal, then the beginning of our local universe, about 14 billion years ago, was preceded by an unknown number of ancestor bubble universes.
Iron in the Service of Chromium: The ortho-Benzannulation of trans,trans-Dienyl Fischer Carbene Complexes

Chromium Fischer carbene complexes with trans,trans-dienyl substituents on the carbene carbon will react with diiron nonacarbonyl to give 2-alkoxycyclohexa-2,4-dienone iron tricarbonyl complexes and/or 2-alkoxyphenols in excellent yields. In the presence of silica gel or base, the cyclohexadienone complex will suffer loss of the iron and aromatization to give 2-alkoxyphenols. The formation of 2-alkoxyphenols from dienyl chromium carbene complexes is a known process (ortho-benzannulation) that only occurs with certain cis,trans-dienyl complexes. Control experiments show that trans,trans-dienyl chromium carbene complexes do not undergo conversion to 2-alkoxyphenols in the absence of an iron source. The process most likely occurs either via coordination of the dienyl unit in the chromium carbene complex to an iron tricarbonyl group and then loss of the chromium or via direct trans-metalation of the carbene ligand to give an iron carbene complex and then internal coordination to the dienyl unit such that cis to trans isomerization of the alpha,beta-double bond occurs.
Lung transplantation: chronic allograft dysfunction and establishing immune tolerance.

Despite significant medical advances since the advent of lung transplantation, improvements in long-term survival have been largely unrealized. Chronic lung allograft dysfunction, in particular obliterative bronchiolitis, is the primary limiting factor. The predominant etiology of obliterative bronchiolitis involves the recipient’s innate and adaptive immune response to the transplanted allograft. Current therapeutic strategies have failed to provide a definitive treatment paradigm to improve long-term outcomes. Inducing immune tolerance is an emerging therapeutic strategy that abrogates allograft rejection, avoids immunosuppression, and improves long-term graft function. The aim of this review is to discuss the key immunologic components of obliterative bronchiolitis, describe the state of establishing immune tolerance in transplantation, and highlight those strategies being evaluated in lung transplantation.
Laser Raman studies of the preparation of platinum and iridium catalyst systems

Abstract Steps in the preparation of Pt, Ir, and PtIr on alumina catalysts have been followed by laser Raman spectroscopy. The samples investigated were prepared by impregnation of alumina with the appropriate chloroplatinic acid and chloroiridic acid solutions. The resulting materials were then heated in air at varying temperatures. Laser Raman spectra indicated significant differences in the nature of the surface species remaining when Pt Al 2 O 3 and Ir Al 2 O 3 preparations were subjected to such thermal treatments. After a drying step at 110 °C, the Pt Al 2 O 3 preparation exhibits Raman bands at frequencies very close to those at which bands have been reported for the PtCl 2− 6 ion, whereas the Ir Al 2 O 3 preparation yields a spectrum significantly different from that reported for the IrCl 2− 6 ion. With increasing temperature, both the platinum and the iridium species decompose with loss of chlorine ligands. After being heated in air at 500 °C, the Ir Al 2 O 3 sample exhibits a Raman spectrum characteristic of crystalline IrO 2 . The presence of platinum in the bimetallic PtIr Al 2 O 3 sample inhibits the formation of crystalline IrO 2 to some degree.
Measurement of fast desorption kinetics of D2, from tungsten by laser induced thermal desorption

Abstract A laser heating technique for studying fast surface processes has been applied in an initial study to the thermal desorption of D 2 from a polycrystalline tungsten sample. This technique is a means for measuring surface reactions at rates, concentrations, and temperatures that approach conditions of technical interest, but with the high degree of definition and control made possible with an ultrahigh vacuum apparatus. The method is analogous to the fast temperature jump method used for studying reactions in condensed phases, and can sort out elementary processes that have differing activation energies. The variation of total flux desorbed with maximum surface temperature reached and initial surface coverage serves, with the aid of a model kinetic rate expression, to determine the desorption rate parameters. It is shown that the desorption of D 2 from W at rates of 5 × 10 7 monolayers/sec is governed by the same kinetics as obtained by extrapolating previous measurements made at a rate about 10 5 times slower. The surface is subjected to a sufficiently fast and large temperature rise to desorb surface atoms or molecules in a time short compared to the range of flight times to a mass spectrometer detector. In this way the velocity distribution of the desorbing species may be determined. This along with the surface temperature history gives additional information on the reaction rate model and also whether the species are emerging in translational thermal equilibrium with the surface. In the present experiments a significant number of desorbatedesorbate collisions occur. Corrections are made for the collision effects in the interpretation of the data. It is shown how modifications of the technique can be made to substantially eliminate these effects. The present conditions were laser pulse width of 3 × 10 −8 sec and surface temperature rise of 300 to 3000 K.
Expander flows, geometric embeddings and graph partitioning

We give a O(√log n)-approximation algorithm for the sparsest cut, edge expansion, balanced separator, and graph conductance problems. This improves the O(log n)-approximation of Leighton and Rao (1988). We use a well-known semidefinite relaxation with triangle inequality constraints. Central to our analysis is a geometric theorem about projections of point sets in Rd, whose proof makes essential use of a phenomenon called measure concentration.We also describe an interesting and natural “approximate certificate” for a graph's expansion, which involves embedding an n-node expander in it with appropriate dilation and congestion. We call this an expander flow.
THE ROLE OF OWNERSHIP AND CORPORATE GOVERNANCE FACTORS IN INTERNATIONAL ENTRY MODE SELECTION

Shareholders are demanding that firms change their ownership and corporate governance structures to improve accountability and corporate performance. This study examined the influence of ownership and governance on entry mode selection, considered a key decision for international firms and one with important financial implications. Results indicate that owner control is related to the selection of higher risk and higher control forms of entry. Partial support was found for the effects of other governance mechanisms.
MIP formulation for robust resource allocation in dynamic real-time systems

Real-time systems usually operate in an environment that changes continuously. These changes cause the performance of the system to vary during run time. An allocation of resources in this environment must be robust. Using the amount of load variation that the allocation can accommodate as a measure of robustness, we develop a mathematical formulation for the problem of robust resource allocation. Due to the complexity of the models used to represent the problem, the formulation is non-linear. We propose a linearization technique based on variable substitution to reduce the mathematical formulation to a mixed integer programming formulation, called SMIP. Compared with existing techniques, the search space of SMIP is not restricted. Thus, if a feasible allocation exists, SMIP will always produce an optimal allocation.
The squashed, stretched, and warped gets perturbed

We use direct Kaluza-Klein reduction to calculate the spectrum of spin-2 modes around a warped product of AdS4 and a certain squashed and stretched 7-sphere. The modes turn out to be polynomials in the four complex variables parameterizing the sphere, and their complex conjugates. The background, which possesses U(1)R × SU(3) symmetry, has been conjectured to be dual to a U(N) × U(N) = 2 superconformal Chern-Simons theory with a sextic superpotential. We find that the U(1)R × SU(3) quantum numbers of spin-2 modes are in agreement with those determined in arXiv:0809.3773 through a group theoretic method, and with the spectrum of spin-2 gauge invariant operators in the Chern-Simons gauge theory. The mass-squared in AdS4 is found to be quadratic in these quantum numbers and the Kaluza-Klein excitation number. Most of the spin-2 operators belong to long multiplets, and we determine their dimensions via the AdS/CFT correspondence.
Interference Mitigation Through Limited Receiver Cooperation

Interference is a major issue limiting the performance in wireless networks. Cooperation among receivers can help mitigate interference by forming distributed MIMO systems. The rate at which receivers cooperate, however, is limited in most scenarios. How much interference can one bit of receiver cooperation mitigate? In this paper, we study the two-user Gaussian interference channel with conferencing decoders to answer this question in a simple setting. We identify two regions regarding the gain from receiver cooperation: linear and saturation regions. In the linear region, receiver cooperation is efficient and provides a degrees-of-freedom gain, which is either one cooperation bit buys one over-the-air bit or two cooperation bits buy one over-the-air bit. In the saturation region, receiver cooperation is inefficient and provides a power gain, which is bounded regardless of the rate at which receivers cooperate. The conclusion is drawn from the characterization of capacity region to within two bits/s/Hz, regardless of channel parameters. The proposed strategy consists of two parts: 1) the transmission scheme, where superposition encoding with a simple power split is employed and 2) the cooperative protocol, where one receiver quantize-bin-and-forwards its received signal and the other after receiving the side information decode-bin-and-forwards its received signal.
Loops in Reeb Graphs of 2-Manifolds

Given a Morse function f over a 2-manifold with or without boundary, the Reeb graph is obtained by contracting the connected components of the level sets to points. We prove tight upper and lower bounds on the number of loops in the Reeb graph that depend on the genus, the number of boundary components, and whether or not the 2-manifold is orientable. We also give an algorithm that constructs the Reeb graph in time O(n log n), where n is the number of edges in the triangulation used to represent the 2-manifold and the Morse function.
Embedded Stellar Clusters in the W3/W4/W5 Molecular Cloud Complex

We analyze the embedded stellar content in the vicinity of the W3/W4/W5 H II regions using the FCRAO Outer Galaxy 12CO (1-0) Survey, the IRAS Point Source Catalog, published radio continuum surveys, and new near-infrared and molecular-line observations. Thirty-four IRAS point sources are identified that have far-infrared colors characteristic of embedded star forming regions, and we have obtained K' mosaics and 13CO (1-0) maps for 32 of them. Ten of the IRAS sources are associated with an OB star and 19 with a stellar cluster, although three OB stars are not identified with a cluster. Half of the embedded stellar population identified in the K' images is found in just the five richest clusters, and 61% is contained in IRAS sources associated with an embedded OB star. Thus, rich clusters around OB stars contribute substantially to the stellar population currently forming in the W3/W4/W5 region. Approximately 39% of the cluster population is embedded in small clouds with an average mass of ≈130 M⊙ that are located as far as 100 pc from the W3/W4/W5 cloud complex. We speculate that these small clouds are fragments of a cloud complex dispersed by previous episodes of massive star formation. Finally, we find that four of the five known embedded massive star forming sites in the W3 molecular cloud are found along the interface with the W4 H II region despite the fact that most of the molecular mass is contained in the interior regions of the cloud. These observations are consistent with the classical notion that the W4 H II region has triggered massive star formation along the eastern edge of the W3 molecular cloud.
Arbitrage-free discretization of lognormal forward Libor and swap rate models

An important recent development in the pricing of interest rate derivatives is the emergence of models that incorporate lognormal volatilities for forward Libor or forward swap rates while keeping interest rates stable. These market models\/ have three attractive features: they preclude arbitrage among bonds, they keep rates positive, and, most distinctively, they price caps or swaptions according to Black's formula, thus allowing automatic calibration to market data. But these features of continuous-time formulations are easily lost when the models are discretized for simulation. We introduce methods for discretizing these models giving particular attention to precluding arbitrage among bonds and to keeping interest rates positive even after discretization. These methods transform the Libor or swap rates to positive martingales, discretize the martingales, and then recover the Libor and swap rates from these discretized variables, rather than discretizing the rates themselves. Choosing the martingales proportional to differences of ratios of bond prices to numeraire prices turns out to be particularly convenient and effective. We can choose the discretization to price one caplet of arbitrary maturity without discretization error. We numerically investigate the accuracy of other caplet and swaption prices as a gauge of how closely a model calibrated to implied volatilities reproduces market prices. Numerical results indicate that several of the methods proposed here often outperform more standard discretizations.
Electro-optic frame photography with pulsed ruby illumination

By combining the attributes of electro-optic shuttering and pulsed laser illumination in a large format camera system, we have developed a multi-frame image converter camera with a laser illuminator that produces sequential photographs of fast phenomena with very high resolution. The combination of the large size image plane (75 mm), short exposure time per frame (minimum 12 - 15 ns), and monochromatic laser illumination provides clear, sharp, front-lit images of surfaces and shapes with no degradation by luminous air shocks or motion blur. The unique modular design of the camera and the laser allow for a variety of configurations and applications. The current camera system produces eight independent pictures or four stereo pairs. A Q-switched ruby laser with multiple pulse capability provides individual illumination for each frame. This system has photographed a variety of fast phenomena including the first stereo sequential photographs of the initial formation and early time history of high velocity shaped-charge jets.
Polarization splitting at infrared wavelengths using silicon nanoridges

We propose a polarization splitting method based on near-field interference. Unlike conventional polarizers, our design does not absorb the undesired polarization but rather deflects light in a polarization-dependent manner. This could enable high efficiency polarization-resolved-imaging.
Studies on morpholinosphingolipids: Potent inhibitors of glucosylceramide synthase

Synthetic 1-morpholino-1-deoxyceramides were designed to inhibit glucosylceramide synthase. The most potent inhibitor 2a possesses the unnatural R,R-configuration of D-threo-sphingosine.
Level spacings for integrable quantum maps in genus zero

We study the pair correlation function for a variety of completely integrable quantum maps in one degree of freedom. For simplicity we assume that the classical phase space M is the Riemann sphere ℂP 1 and that the classical map is a fixed-time map of a Hamilton flow. The quantization is then a unitary N × N matrix U t , N and its pair correlation measure gives the distribution of spacings between eigenvalues in an interval of length comparable to the mean level spacing (∼ 1/N). The physicists' conjecture (Berry–Tabor conjecture) is that as , should converge to the pair correlation function of a Poisson process. For any 2-parameter family of Hamiltonians of the form with we prove that this conjecture is correct for almost all (α, β) along the subsequence of Planck constants . In the addendum to this paper [Z. Addendum], we further show that for polynomial phases φ the a.e. convergence to Poisson holds along the full sequence of Planck constants for the Cesaro means of .
System Thermodynamics of Energy Conversion Plants for Geopressured Resources

Performance of conversion plants for geopressured fluids has been predicted using realistic wellhead conditions and idealized thermodynamics. A method is developed for estimating the maximum output of a combined hydraulic-thermal recovery system. Performance of both flash and organic Rankine cycle schemes for thermal recovery is considered and the importance of hydraulic recovery is illustrated. Rankine cycle performance results for propane and isobutane are presented. Results are also given which illustrate the extreme importance of recovering dissolved methane due to its effect on both energy production and related economic viability.
A note on spatial–temporal lattice modeling and maximum likelihood estimation

Abstract Spatial–temporal linear models and the corresponding likelihood-based statistical inference are important tools for the analysis of spatial–temporal lattice data. In this paper, we study the asymptotic properties of maximum likelihood estimates under a general asymptotic framework for spatial–temporal linear models. We propose mild regularity conditions on the spatial–temporal weight matrices and derive the asymptotic properties (consistency and asymptotic normality) of maximum likelihood estimates. A simulation study is conducted to examine the finite-sample properties of the maximum likelihood estimates.
The Tropospheric Response to Tropical and Subtropical Zonally Asymmetric Torques: Analytical and Idealized Numerical Model Results

AbstractThe tropospheric response to prescribed tropical and subtropical zonally asymmetric torques, which can be considered as idealizations of vertical momentum transfers by orographic gravity waves or convection, is investigated. The linear analytical Gill model response to westward upper-tropospheric torques is compared to the response to a midtropospheric heating, which is a familiar point of reference. The response to an equatorial torque projects onto a Kelvin wave response to the east that is of opposite sign to the response to the east of the heating at upper levels. In contrast, the torque and heating both produce Rossby gyres of the same sign to the west of the forcing and the zonal-mean streamfunction responses are identical. When the forcings are shifted into the Northern Hemisphere, the streamfunction responses have opposite signs: there is upwelling in the Southern (Northern) Hemisphere in response to the torque (heating).The nonlinear response to westward torques was explored in idealized ...
Generalized Derivatives for Solutions of Parametric Ordinary Differential Equations with Non-differentiable Right-Hand Sides

Sensitivity analysis provides useful information for equation-solving, optimization, and post-optimality analysis. However, obtaining useful sensitivity information for systems with nonsmooth dynamic systems embedded is a challenging task. In this article, for any locally Lipschitz continuous mapping between finite-dimensional Euclidean spaces, Nesterov's lexicographic derivatives are shown to be elements of the plenary hull of the (Clarke) generalized Jacobian whenever they exist. It is argued that in applications, and in several established results in nonsmooth analysis, elements of the plenary hull of the generalized Jacobian of a locally Lipschitz continuous function are no less useful than elements of the generalized Jacobian itself. Directional derivatives and lexicographic derivatives of solutions of parametric ordinary differential equation (ODE) systems are expressed as the unique solutions of corresponding ODE systems, under Caratheodory-style assumptions. Hence, the scope of numerical methods for nonsmooth equation-solving and local optimization is extended to systems with nonsmooth parametric ODEs embedded.
The trouble with sanctions: Organizational responses to deviant anger displays at work

This article examines management and coworker reactions to employee anger expressions that violate salient emotion display norms, for example, deviant anger, and explores whether these reactions can promote subsequent positive change at work. Full-time US employees volunteered information about workplace anger expressions they personally witnessed and felt ‘went too far’. Using open-ended survey questions, we identified three categories of deviant anger (physical acts, intense verbal displays, and inappropriate communication), as well as various formal and informal sanctioning and supportive responses initiated by organizational observers. Additional data collection and generalized linear modeling analysis revealed that when coworkers and management responded supportively to the angry employee (rather than with sanctions or doing nothing), favorable change occurred, improving the problematic situation. Implications for future research, management practices, and employee socialization are discussed.
Optimal Patent Breadth: Quantifying the Effects of Increasing Patent Breadth

In a generalized quality-ladder growth model, this paper firstly derives the optimal patent breadth and the socially optimal profit-sharing arrangement between patentholders. In this general-equilibrium setting, it identifies and derives a dynamic distortion of markup pricing on capital accumulation that has been neglected by previous studies on patent policy. Then, it quantitatively evaluates the effects of eliminating blocking patent and increasing patent breadth, and this exercise suggests a number of findings. Firstly, the market economy underinvests in R&D so long as a non-negligible fraction of long-run TFP growth is driven by R&D. Secondly, increasing patent breadth may be an effective solution to R&D underinvestment. The resulting effect on long-run consumption can be substantial because the harmful distortionary effects are relatively insignificant. However, the damaging effect of blocking patent arising from suboptimal profit-sharing arrangements between patentholders can be quantitatively significant. Finally, it considers the effect on consumption during the transition dynamics.
Cell Shape Can Mediate the Spatial Organization of the Bacterial Cytoskeleton

The bacterial cytoskeleton guides the synthesis of cell wall and thus regulates cell shape. Because spatial patterning of the bacterial cytoskeleton is critical to the proper control of cell shape, it is important to ask how the cytoskeleton spatially self-organizes in the first place. In this work, we develop a quantitative model to account for the various spatial patterns adopted by bacterial cytoskeletal proteins, especially the orientation and length of cytoskeletal filaments such as FtsZ and MreB in rod-shaped cells. We show that the combined mechanical energy of membrane bending, membrane pinning, and filament bending of a membrane-attached cytoskeletal filament can be sufficient to prescribe orientation, e.g., circumferential for FtsZ or helical for MreB, with the accuracy of orientation increasing with the length of the cytoskeletal filament. Moreover, the mechanical energy can compete with the chemical energy of cytoskeletal polymerization to regulate filament length. Notably, we predict a conformational transition with increasing polymer length from smoothly curved to end-bent polymers. Finally, the mechanical energy also results in a mutual attraction among polymers on the same membrane, which could facilitate tight polymer spacing or bundling. The predictions of the model can be verified through genetic, microscopic, and microfluidic approaches.
Parity-Violation With Electrons: Theoretical Perspectives

I review recent progress and developments in parity-violating electron scattering as it bears on three topics: strange quarks and hadron structure, electroweak radiative corrections, and physics beyond the Standard Model. I also discuss related developments in parity-conserving scattering with transversely polarized electrons as a probe of two-photon processes. I conclude with a perspective on the future of the field.