cssi/SciSciGPT-SciSciNet huggingface dataset:
DISTINGUISHING UNENTANGLED STATES WITH AN UNENTANGLED MEASUREMENT

In a 1991 paper, Asher Peres and the author theoretically analyzed a set of unentangled bipartite quantum states that could apparently be distinguished better by a global measurement than by any sequence of local measurements on the individual subsystems. The present paper returns to the same example, and shows that the best result so far achieved can alternatively be attained by a measurement that, while still global, is "unentangled" in the sense that the operator associated with each measurement outcome is a tensor product.
Effect of unsteady flow on nitrate loss in an oligotrophic, glacial meltwater stream

[1] The McMurdo Dry Valleys of Antarctica are among the coldest, driest ecosystems on Earth. During the austral summer, glacial meltwater supports cyanobacterial mat communities in some streams, but they are not ubiquitous. We conducted a nitrate (NO3−) enrichment tracer injection in Huey Creek to quantify NO3− loss in a Dry Valley stream where algal mats would not obscure hyporheic microbial processes. Unsteady streamflow led to diel variability in the tracer concentration and in surface/subsurface water and solute exchange. Subsequently, concentrations of NO3−, nitrite (NO2−), ammonium (NH4+), and dissolved organic carbon (DOC) varied significantly during the injection, with a net loss of NO3−, NO2−, and DOC, and production of nitrous oxide. These mass changes within a reach were often coincident with high streamflows. Reactivity also coincided with the highest DOC concentrations, suggesting that DOC is the primary limitation to heterotrophic microbial activity in the stream. Together, streamflow and DOC availability create the hot spots and hot moments that dominate NO3− reactivity and removal in this polar desert ecosystem. The combination of spatially and temporally variable hyporheic dynamics and solute availability underscore the limitations of common nutrient uptake metrics and transient storage models when unsteady flow conditions exist.
Constructing rational curves on K3 surfaces

We develop a mixed-characteristic version of the Mori-Mukai technique for producing rational curves on K3 surfaces. We reduce modulo p, produce rational curves on the resulting K3 surface over a finite field, and lift to characteristic zero. As an application, we prove that all complex K3 surfaces with Picard group generated by a class of degree two have an infinite number of rational curves.
Cosmological implications of domain walls due to duality invariant moduli sector of superstring vacua

Abstract We study cosmological implications of the duality (PSL(2, Z )) invariant potential for the compactification radius T, arising in a class of superstring vacua. We show that in spite of having only one minimum in the fundamental domain of the T field there are two types of non-supersymmetric domain walls: one is associated with the discrete Peccei-Quinn symmetry T→T+i, analogous to the axionic domain wall, and another one associated with the noncompact symmetry T→ 1 T , analogous to the Z2 domain walls. The first one is bound by stringy cosmic strings. The scale of such domain walls is governed by the scale of gaugino condensation (O(1016 GeV) in the case of the hidden E8 gauge group), while the separation between minima is of the order of MPl. We discuss the formation of walls and their cosmological implications: the walls must be gotten rid of, either by chopping by stringy cosmic strings and/or inflation. Since there is no Kibble mechanism to create strings, either one must assume they exist ab initio, or one must conclude that string cosmologies require inflation. The non-perturbative potential dealt with here appears not to give the needed inflationary epoch.
Information, Search, and House Prices: Revisited

Buyers pay different prices for nearly identical homes. One explanation for this is that housing markets are thin, resulting in price bargaining between sellers and buyers. If the relative bargaining power of buyers varies, so will sales prices. One hypothesis is that the relative bargaining strength of buyers coming from outside the local market relative to that of local residents is weak, because distant buyers have high search costs and may know less about the nuances of the local market. Our results, based upon a large number of single-family home transactions from the state of Florida, lend support to this hypothesis. Another related hypothesis is that buyers’ price expectations are anchored to prices they were accustomed to at their previous residence. Hence, if they come from high price markets they will tend to pay more for their new home. This hypothesis is also supported by our results.
Penalty finite element models for nonlinear dynamic analysis

A simple penalty finite element formulation is presented for the large-rotation dynamic analysis of curved beams. The analytical formulation is based on a form of Reissner's large-deformation theory with the effects of transverse shear deformation and the extensibility of the centerline constrained through the use of the penalty method. Reduced integration is used in evaluating the elemental stiffness arrays, and the temporal integration is performed by using Newmark's method. Numerical results are presented to demonstrate the effectiveness of the finite elements developed.
Synthetic approaches to a fluorinated tetrahedrane

Abstract Approaches to tetrakis(2-chlorotetrafluoroethyl)tetrahedrane ( 2 ) from 1,6-dichlorooctafluoro-3-hexyne ( 4 ) have been explored. The synthesis and chemistry are described of cyclopropenyl ketenimines ( 6a , b ), a Dewar thiophene ( 24 ) and a cyclobutadienetricarbonyliron complex ( 33 ) derived from this acetylene.
Curvature Dimension Inequalities and Subelliptic Heat Kernel Gradient Bounds on Contact Manifolds

We study curvature dimension inequalities for the sub-Laplacian on contact Riemannian manifolds. This new curvature dimension condition is then used to obtain: Geometric conditions ensuring the compactness of the underlying manifold (Bonnet–Myers type results); Volume estimates of metric balls; Gradient bounds and stochastic completeness for the heat semigroup generated by the sub-Laplacian; Spectral gap estimates.
Late Metal Carbene Complexes Generated by Multiple C−H Activations: Examining the Continuum of M═C Bond Reactivity

Unactivated Csp3−H bonds are ubiquitous in organic chemicals and hydrocarbon feedstocks. However, these resources remain largely untapped, and the development of efficient homogeneous methods for hydrocarbon functionalization by C−H activation is an attractive and unresolved challenge for synthetic chemists. Transition-metal catalysis offers an attractive possible means for achieving selective, catalytic C−H functionalization given the thermodynamically favorable nature of many desirable partial oxidation schemes and the propensity of transition-metal complexes to cleave C−H bonds. Selective C−H activation, typically by a single cleavage event to produce M−Csp3 products, is possible through myriad reported transition-metal species. In contrast, several recent reports have shown that late transition metals may react with certain substrates to perform multiple C−H activations, generating M═Csp2 complexes for further elaboration. In light of the rich reactivity of metal-bound carbenes, such a route could ope...
Long-Term Skewness and Systemic Risk

Financial risk management has generally focused on short-term risks rather than long-term risks, and arguably this was an important component of the recent financial crisis. Econometric approaches to measuring long-term risk are developed in order to estimate the term structure of value at risk and expected shortfall. Long-term negative skewness increases the downside risk and is a consequence of asymmetric volatility models. A test is developed for long-term skewness. In a Merton style structural default model, bankruptcies are accompanied by substantial drops in equity prices. Thus, skewness in a market factor implies high defaults and default correlations even far in the future corroborating the systemic importance of long-term skewness. Investors concerned about long-term risks may hedge exposure as in the Intertemporal Capital Asset Pricing Model (ICAPM). As a consequence, the aggregate wealth portfolio should have asymmetric volatility and hedge portfolios should have reversed asymmetric volatility. Using estimates from VLAB, reversed asymmetric volatility is found for many possible hedge portfolios such as volatility products, long- and shortterm treasuries, some exchange rates, and gold. ( JEL: G01)
Does one size fit all? The suitability of standard ozone exposure metric conversion ratios and implications for epidemiology

Several exposure metrics have been applied in health research and policy settings to represent ozone exposure, such as the 24 h average and daily 8 h maximum. Frequently, results calculated using one exposure metric are converted using a simple ratio to compare or combine findings with results using a different metric. This conversion, however, assumes that such a ratio is constant across locations and time periods. We investigated the appropriateness of this conversion method by examining the relationships among various forms of ozone concentrations (24 h average, daily 1 h maximum, and daily 8 h maximum) within and between communities for 78 US communities from 2000 to 2004 and compared results to commonly used conversion ratios. We explored whether the relationships between ozone exposure metrics differ by region, weather, season, and city-specific characteristics. Analysis revealed variation in the relationship among ozone metrics, both across communities and across time within individual communities, indicating that conversion of ozone exposure metrics with a standard ratio introduces uncertainty. For example, the average ratio of the daily 8 h maximum to the daily concentration ranged from 1.23 to 1.83. Within a community, days with higher ozone levels had lower ratios. Relationships among metrics within a community were associated with daily temperature. The community-average exposure metric ratios were lower for communities with higher long-term ozone levels. Ozone metric ratios differed by season because of the different rate of change of ozone metrics throughout the year. We recommend that health effects studies present results from multiple ozone exposure metrics, if possible. When conversions are necessary, more accurate estimates can be obtained using summaries of data for a given location and time period if available, or by basing conversion ratios on data from a similar city and season, such as the results provided in this study.
Complications and results of phacoemulsification performed by residents

Abstract The use of phacoemulsification by ophthalmic surgeons has increased markedly over the past five years. Previous studies have reported relatively high rates of vitreous loss by residents learning phacoemulsification. We retrospectively analyzed the complications and results in 300 cases of phacoemulsification with intraocular lens implantation performed by residents. The first 40 cases done by four residents in their second year of training were compared with approximately the last 40 cases done by each resident at the end of the third year. The overall rate of surgical complications was 6.3%, and the total rate of vitreous loss was 3.3%. The rate of surgical complications during the initial surgeries in the second year of residency was 9.3%; it was 3.3% by the end of the third year. The rate of vitreous loss was 5.3% in the second year and 1.3% during the third year. Postoperatively, 90.6% of all eyes had a final best corrected visual acuity of 20/40 or better (95% excluding patients with pre-existing ocular disease). With proper training and supervision, the rate of surgical complications for residents learning phacoemulsification is acceptably low when compared with the rate for extracapsular cataract extraction.
Clusters, Coxeter-sortable elements and noncrossing partitions

We introduce Coxeter-sortable elements of a Coxeter group For finite we give bijective proofs that Coxeter-sortable elements are equinumerous with clusters and with noncrossing partitions. We characterize Coxeter-sortable elements in terms of their inversion sets and, in the classical cases, in terms of permutations
Autonomous reactor control using model based predictive control for space propulsion applications

Abstract Reliable reactor control is important to reactor safety, both in terrestrial and space systems. For a space system, where the time for communication to Earth is significant, autonomous control is imperative. Based on feedback from reactor diagnostics, a controller must be able to automatically adjust to changes in reactor temperature and power level to maintain nominal operation without user intervention. Model-based predictive control (MBPC) is investigated as a potential control methodology for reactor start-up and transient operation in the presence of either a constant or a time varying external source. Bragg-Sitton and Holloway [Bragg-Sitton, S.M., Holloway, J.P., 2004. Reactor start-up and control methodologies. In: El-Genk, M. (Ed.), Proceedings of the Space Technology and Applications International Forum (STAIF-2004), AIP Conference Proceedings 699, pp. 614–622.] assessed the applicability of MBPC to reactor start-up from a cold, zero-power condition in the presence of a time-varying external radiation source, where large fluctuations in the external radiation source can significantly impact a reactor during start-up operations. Here the MBPC algorithm is applied using the point kinetics model to describe the reactor dynamics, with a single group of delayed neutrons and a fast neutron lifetime of 10 −7 s. Controller stability is assessed by carefully considering the dependencies of each component in the defined cost (objective) function and its subsequent effect on the selected “optimal” control maneuvers. Additional analysis demonstrates the effectiveness of the controller when a lower fidelity reactor kinetics model is adopted for the model system versus using a full six-group delayed neutron representation in the point kinetics equations to represent the “real” system operation.
Catalytic asymmetric methallylation of ketones with an (H8-BINOLate)Ti-based catalyst.

The first catalytic asymmetric methallylation of ketones is reported. The catalyst, which is generated from titanium tetraisopropoxide, H8-BINOL, isopropanol, and tetramethallylstannane, reacts with ketones in acetonitrile to afford tertiary homoallylic alcohols in fair to excellent yields (55-99%) and fair to high enantioselectivities (46-90%). Ozonolysis of the resulting products provides access to chiral β-hydroxy ketones, which are not readily prepared from direct asymmetric aldol reaction of acetone with ketones.
Defending the Right To Do Wrong

Are there moral rights to do moral wrong? A right to do wrong is a right that others not interfere with the right-holder’s wrongdoing. It is a right against enforcement of duty, that is a right that others not interfere with one’s violation of one’s own obligations. The strongest reason for moral rights to do moral wrong is grounded in the value of personal autonomy. Having a measure of protected choice (that is a right) to do wrong is a condition for an autonomous life and for autonomous moral self-constitution. This view has its critics. Responding to these objections reveals that none refute the coherence of the concept of a ‘moral right to do moral wrong’. At most, some objections successfully challenge the weight and frequency of the personal autonomy reasons for such rights. Autonomy-based moral rights to do moral wrong are therefore conceptually possible as well as, at least on occasion, actual.
Furan Decorated Nucleoside Analogues as Fluorescent Probes: synthesis, photophysical evaluation and site-specific incorporation.

Abstract The synthesis and photophysical evaluation of modified nucleoside analogues in which a five-membered heterocycle (furan, thiophene, oxazole, and thiazole) is attached to the 5-position of 2′-deoxyuridine are reported. The furan-containing derivative is identified as the most promising responsive nucleoside of this family due to its emission quantum efficiency and degree of sensitivity to its microenvironment. The furan moiety was then attached to the 5-position of 2′-deoxycytidine as well as the 8-position of adenosine and guanosine. Photophysical evaluation of these four furan-containing nucleoside analogues reveals distinct differences in the absorption, emission, and quantum efficiency depending upon the class of nucleoside (pyrimidine or purine). Comparing the photophysical properties of all furan-containing nucleosides, identifies the furan thymidine analogue, 5-(fur-2-yl)-2′-deoxyuridine, as the best candidate for use as a responsive fluorescent probe in nucleic acids. 5-(Fur-2-yl)-2′-deoxyuridine was then converted to the corresponding phosphoramidite and site specifically incorporated into DNA oligonucleotides with greater than 88% coupling efficiency. Such furan-modified oligonucleotides form stable duplexes upon hybridization to their complementary DNA strands and display favorable fluorescent features.
π-Nucleophile Traps for Metallonitrene/Alkyne Cascade Reactions: A Versatile Process for the Synthesis of α-Aminocyclopropanes and β-Aminostyrenes

The reaction of a sulfamate ester derived rhodium nitrenoid species with an alkyne produces a versatile intermediate, capable of cascading into a wide variety of secondary transformations. The nature of the intermediate has been probed by reactivity studies, and the synthetic utility of the cascade process, which facilitates the construction of complex heterocyclic structures from remarkably simple acyclic precursors, is highlighted.
Detecting Loosening of Bolted Connections in a Pipeline Using Changes in Natural Frequencies

Loosening of bolted connections in a structure can significantly reduce the load-bearing capacities of the structure. Detecting loosening of bolted connections at an early stage can avoid failure of the structure. Due to the complex geometry of a bolted connection and the material discontinuity between the clamped components, it is difficult to detect loosening of a bolted connection using conventional non-destructive test methods. A vibration-based method that uses changes in natural frequencies of a structure to detect the locations and extent of damage can be used to detect loosening of bolted connections, since the method focuses on detecting a stiffness reduction, which can result from loosening of the bolted connections. Experimental and numerical damage detection using the vibration-based method was conducted to detect the loosening of the bolted connections in a fullsize steel pipeline with bolted flanges. With the recent development of a predictive modeling technique for bolted connections in thin-walled structures, an accurate physics-based finite element model of the pipeline that is required by the vibration-based damage detection method is developed. A trust-region search strategy is employed to improve the damage detection method so that convergence of the damage detection algorithm can be ensured for under-determined systems, and the robustness of the algorithm can be enhanced when relatively large modeling error and measurement noise are present. The location and extent of the loosened bolted connections were successfully detected in experimental damage detection using changes in the natural frequencies of the first several modes; the exact location and extent of the loosened bolted connections can be detected in the numerical simulation where there are no modeling error and measurement noise.Copyright © 2011 by ASME
To the Far Side of the Sun Using Venus Gravity Assist

The recent NASA initiative to investigate our sun in depth, called "Living with a Star," includes consideration of several possible deep-space missions, one of which is placing a satellite on the far side of the sun. Thissatellite, together with Earth, can then observe the full evolution of solar phenomena as the sun rotates. Unfortunately, in using a direct approach celestial mechanics does not permit satellite placement to be done efficiently and in a timely manner. Here, the direct approach for satellite placement is shown to be costly compared with the use of Venus gravity assist. This paper investigates specifically the insertion of a far-side sentinel satellite in the year 2009 into the third quadrant (180 to 270 deg ahead of Earth) using single and double Venus gravity assists. Options for other possible missions, including a distributed set of solar observers, are briefly analyzed.
Market integration and currency risk in Asian emerging markets

Abstract Most of the Asian emerging stock markets started to liberalize their markets in 1990s. In this paper, I examine whether those markets have become integrated with world stock market since the 1990s by estimating and testing a dynamic version of international CAPM (ICAPM) in the absence of purchasing power parity (PPP) using a parsimonious multivariate GARCH-in-Mean (MGARCH-M) approach. I also investigate to what extent the liberalization process has affected the cost of capital and price volatility for each market. The empirical results show that Philippines was segmented from the world stock market before its liberalization date, but no evidence of market segmentation is found for the other five markets (India, Korea, Malaysia, Taiwan, and Thailand) before their liberalization dates. However, all six markets have become integrated after opening up their markets to foreign investors. In addition, the estimated risk premia are lower after the liberalization, indicating that the liberalization process has reduced the cost of capital for their domestic firms. Moreover, there is no evidence of extra market volatility introduced by capital market liberalization, and on the contrary, the markets have become more stabilized through the liberalization process.
Stimuli sensitive amphiphilic dendrimers

In the past decade, there has been an increasing interest in supramolecular systems that can undergo physical or chemical transformations upon encountering a specific stimulus. Micelle-forming amphiphilic systems based on polymers and dendrimers are particularly preferred over small molecule amphiphiles, due to their ability to sequester and release a vast library of hydrophobic guest molecules at micromolar polymer or dendrimer concentrations. Here we review a relatively underexplored, yet rapidly advancing, field of amphiphilic systems based on a dendritic architecture that exhibit stimuli sensitive behaviour. In particular, we will be focusing on stimuli such as temperature, pH, enzymatic and non-enzymatic proteins. These stimuli-responsive systems offer a unique opportunity in the field of drug delivery and sensing.
Polymorphism in NaSbO3: structure and bonding in metal oxides.

A new polymorph of NaSbO3 has been synthesized at 10.5 GPa and 1150 °C in a uniaxial split sphere anvil type press (USSA-2000) and recovered back to ambient conditions. The high-pressure form of NaSbO3 adopts an orthorhombically distorted perovskite structure, isostructural with CaTiO3, GdFeO3, and NaTaO3. The space group is Pnma, and the unit cell dimensions are a = 5.43835(6) A, b = 7.66195(8) A, c = 5.38201(5) A. It is a white insulator with an optical band gap of 3.4 eV. This compound represents the first ternary perovskite prepared containing Sb5+ on the octahedral site. The octahedral tilting distortion in this compound is much larger than expected from ionic radii considerations. The distortion is driven by a second-order Jahn−Teller distortion originating on oxygen that can be traced back to strong Sb−O covalent bonding. A conflict arises between the strong covalent bonding interactions at oxygen that favor a large octahedral tilting distortion and the repulsive Na−O interactions that oppose exces...
Fault Detection of Helicopter Gearboxes Using the Multi-Valued Influence Matrix Method

In this paper we investigate the effectiveness of a pattern classifying fault detection system that is designed to cope with the variability of fault signatures inherent in helicopter gearboxes. For detection, the measurements are monitored on-line and flagged upon the detection of abnormalities, so that they can be attributed to a faulty or normal case. As such, the detection system is composed of two components, a quantization matrix to flag the measurements, and a multi-valued influence matrix (MVIM) that represents the behavior of measurements during normal operation and at fault instances. Both the quantization matrix and influence matrix are tuned during a training session so as to minimize the error in detection. To demonstrate the effectiveness of this detection system, it was applied to vibration measurements collected from a helicopter gearbox during normal operation and at various fault instances. The results indicate that the MVIM method provides excellent results when the full range of faults effects on the measurements are included in the training set.
Technologies for low latency interconnection switches

This paper presents an engineering design for a low latency high bandwidth interconnection network which will form the switching substrate for a multi-model parallel processing system. The performance is enhanced with a variety of approaches covering interconnection protocols, routing, fault tolerance, advanced packaging, and electrical interconnection techniques. The synergistic application of these technologies leads to a high performance design.
Changes in brain functional homogeneity in subjects with Alzheimer's disease.

Imaging studies have reported marked reductions in brain glucose metabolism in Alzheimer's Disease (AD). However, less is known about disruptions in the patterns of brain metabolic activity. Here we questioned whether AD affects the patterns of homogeneity/heterogeneity in brain metabolism. PET images of 35 AD subjects were compared with those of 35 controls. A template was applied to extract a cortical rim, which was partitioned into 990 contiguous regions. Estimates of metabolic homogeneity were obtained using the coefficient of variation (CV). The CV of the entire cortex was found to be significantly larger in AD, suggesting increased heterogeneity at the whole brain level. In contrast, regional CV was significantly lower in AD in temporal and parietal cortices, which were the regions that along with the precuneus had the largest metabolic decrements, though the precuneus had increased CV. The enhanced heterogeneity for the global cortical pattern most likely reflects variability in the degree of pathology among brain regions as well as neuroanatomical disconnection. The enhanced homogeneity in parietal and temporal cortices is likely to reflect loss of regional differentiation (i.e. macrocolumnar disorganization). The enhanced CV in precuneus, despite its marked reductions in metabolism, suggests that increases in regional homogeneity in parietal and temporal cortices are not a mere reflection of the decrement in metabolism.
LINE SHAPE ANALYSIS OF LINEAR X-RAY MAGNETIC SCATTERING CoPt THIN FILMS

Data analysis of the CCD files from X-ray magnetic resonant scattering were performed. Measurements from a series of increasing photon energies were used. Azimuthal and radial intensity variations were analyzed.
Low-Temperature Electron Spin Resonance in (TMTSF)2PF6 in the High Pressure Metallic Phase

Abstract The electron spin resonance of (TMTSF)2PF6 has been observed at low fields (Ho 6.5 kbar) in the temperature range 1-4−K. The anisotropy in the g value is similar to that observed at ambient pressure above the metal-insulator transition. The linewidth is very narrow and the spin susceptibility strongly decreases as the superconducting transition is approached from above. We interpret this as evidence for singlet-paired superconductivity. Superconductivity is observed at 1.1 K and the critical field has angular dependence in the be plane. These observations lead us to conclude that (TMTSF)2PF6 is a singlet paired superconductor.
New homochiral amino-phosphine ligands: application in asymmetric palladium catalyzed allylic alkylation

Abstract A new series of homochiral amino-phosphine ligands was prepared. The use of these ligands in the palladium catalyzed allylic alkylation of 1,3-diphenyl-1-acetoxy-2-propene with sodium malonate gave substitution products with up to 76% e.e. The enantioselectivity was largely dependent on the nitrogen substituent.
A GMBCG galaxy cluster catalog of 55,424 rich clusters from SDSS DR7

We present a large catalog of optically selected galaxy clusters from the application of a new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data. The algorithm detects clusters by identifying the red sequence plus Brightest Cluster Galaxy (BCG) feature, which is unique for galaxy clusters and does not exist among field galaxies. Red sequence clustering in color space is detected using an Error Corrected Gaussian Mixture Model. We run GMBCG on 8240 square degrees of photometric data from SDSS DR7 to assemble the largest ever optical galaxy cluster catalog, consisting of over 55,000 rich clusters across the redshift range from 0.1 < z < 0.55. We present Monte Carlo tests of completeness and purity and perform cross-matching with X-ray clusters and with the maxBCG sample at low redshift. These tests indicate high completeness and purity across the full redshift range for clusters with 15 or more members.
Two Classes of Hot Jupiters

We identify two classes of transiting planet, based on their equilibrium temperatures and Safronov numbers. We examine various possible explanations for the dichotomy. It may reflect the influence of planet or planetesimal scattering in determining when planetary migration stops. Another possibility is that some planets lose more mass to evaporation than others. If this evaporation process preferentially removes helium from the planet, the consequent reduction in the mean molecular weight may explain why some planets have anomalously large radii.
THE DYNAMICS OF KNOWN CENTAURS

We have numerically investigated the long-term dynamical behavior of known Centaurs. This class of objects is thought to constitute the transitional population between the Kuiper belt and the Jupiter-family comets (JFCs). In our study, we find that over their dynamical lifetimes these objects diffuse into the JFCs and other sinks, and they also make excursions into the scattered disk, but (not surprisingly) do not diffuse into the parameter space representing the main Kuiper belt. These Centaurs spend most of their dynamical lifetimes in orbits of eccentricity 0.2–0.6 and perihelion distance 12–30 AU. Their orbital evolution is characterized by frequent close encounters with the giant planets. Most of these Centaurs will escape from the solar system (or enter the Oort cloud), while a fraction will enter the JFC population and a few percent will impact a giant planet. Their median dynamical lifetime is 9 Myr, although there is a wide dispersion in lifetimes, ranging from less than 1 Myr to more than 100 Myr. We find the dynamical evolution of this sample of Centaurs to be less orderly than the planet-to-planet "handoff" described in previous investigations. We discuss the implications of our study for the spatial distribution of the Centaurs as a whole.
Dimethylaluminum methyltellurate, a new reagent for the cleavage of hindered methyl esters under exceptionally mild conditions by a novel mechanism

Abstract An efficient and effective new reagent (Me2AlTeMe)2 has been developed for the conversion of methyl esters to the corresponding carboxylic acids in toluene solution at 23 °C.
Hot-electron-induced MOSFET degradation&#8212;Model, monitor, and improvement

Evidence suggests that MOSFET degradation is due to interface-states generation by electrons having 3.7 eV and higher energies. This critical energy and the observed time dependence is explained with physical model involving the breaking of the ≡ Si s H bonds. The device lifetime τ is proportional to I_{sub}^{-2.9}I_{d}^{1.9}\Delta V_{t}^{1.5} . If I sub is large because of small L or large V d , etc., τ will be small. I sub (and possibly light emission) is thus a powerful predictor of τ. The proportionality constant has been found to vary by a factor of 100 for different technologies, offering hope for substantially better reliability through future improvements in dielectric /interface technologies. A simple physical model can relate the channel field E m to all the device parameters and bias voltages. Its use in interpreting and guiding hot-electron scaling are described. LDD structures can reduce E m and I sub and, when properly designed, reduce device degradation.
Fusion, mass, and representation theory of the Yangian algebra

Abstract Based on the formulation of Drinfel'd, Chari, and Pressley, a technique to analyze the structure of tensor products of the Yangian algebra representations is presented. We then apply the results to the S-matrix theory of the G × G-invariant nonlinear σ-model (G-principal chiral model) by Ogievetsky, Reshetikhin, and Wiegmann. We show how the physical data such as mass formula, fusion angle, and the spins of integrals of motion can be extracted from the Yangian highest weight representations.
Evidence of crossover phenomena in wind-speed data

In this paper, a systematic analysis of hourly wind-speed data obtained from three potential wind-generation sites (in North Dakota) is analyzed. The power spectra of the data exhibited a power-law decay characteristic of 1/f/sup /spl alpha// processes with possible long-range correlations. Conventional analysis using Hurst exponent estimators proved to be inconclusive. Subsequent analysis using detrended fluctuation analysis revealed a crossover in the scaling exponent (/spl alpha/). At short time scales, a scaling exponent of /spl alpha//spl sim/1.4 indicated that the data resembled Brownian noise, whereas for larger time scales the data exhibited long-range correlations (/spl alpha//spl sim/0.7). The scaling exponents obtained were similar across the three locations. Our findings suggest the possibility of multiple scaling exponents characteristic of multifractal signals.
CD26 inhibition enhances allogeneic donor cell homing and engraftment after in utero bone marrow transplantation

In utero bone marrow transplantation (IUBMT) induces donor-specific tolerance for postnatal cellular or organ transplantation. Consistent induction of tolerance requires a threshold of mixed hematopoietic chimerism (>1%). CD26 is a peptidase whose inhibition has been demonstrated to influence granulocyte colony-stimulating factor induced mobilization of hematopoietic stem cells and increase homing and engraftment of BM cells in adult transplantation models. We hypothesized that CD26 inhibition would increase the frequency and levels of allogeneic hematopoietic chimerism after IUBMT. Methods: B6 GFP BM was injected intravenously into E14 Balb/c fetal mice at a dose of 20e 6 cells/fetus with or without CD26 inhibition with diprotin A. Early kinetic analysis was performed to assess donor cell homing to fetal liver (FL). Peripheral blood (PB) was analyzed up to 20 weeks after birth for donor cell chimerism and multilineage engraftment by flow cytometry. PB was also analyzed for donor cell chimerism at the same time points from Balb/c mice receiving 10e 6 CD26 inhibited GFP BM cells coinjected with 10e 6 noninhibited congenic B6Ly5.2 BM cells at E14 to assess for an in utero competitive advantage provided by CD26 inhibition. Results: CD26 inhibition increased donor cell homing to the FL at 24, 48 and 96 hours after injection (69.27±8.19 vs 30.21±6.44, 57.20±14.63 vs 36.80±14.20, 46.14±15.79 vs 12.09±7.01; p Conclusion: CD26 inhibition of donor BM prior to IUBMT results in an increased efficiency of donor engraftment and higher levels of chimerism. CD26 inhibition offers a potential mechanism to increase the level of engraftment and the rate of donor specific tolerance and may facilitate combined pre and postnatal strategies for cellular and organ transplantation.
Achievable throughput of multi-mode multiuser MIMO with imperfect CSI constraints

In the multiple-input multiple-output (MIMO) broadcast channel with imperfect channel state information (CSI), neither the capacity nor the optimal transmission technique have been fully discovered. In this paper, we derive achievable ergodic rates for a multi-antenna fading broadcast channel when CSI at the transmitter (CSIT) is delayed and quantized. It is shown that not all possible users should be supported with spatial division multiplexing due to the residual inter-user interference caused by imperfect CSIT. Based on the derived achievable rates, we propose a multi-mode transmission strategy to maximize the throughput, which adaptively adjusts the number of active users based on the channel statistics information.
Clustering of diverse genomic data using information fusion

Motivation: Genome sequencing projects and high-through-put technologies like DNA and Protein arrays have resulted in a very large amount of information-rich data. Microarray experimental data are a valuable, but limited source for inferring gene regulation mechanisms on a genomic scale. Additional information such as promoter sequences of genes/DNA binding motifs, gene ontologies, and location data, when combined with gene expression analysis can increase the statistical significance of the finding. This paper introduces a machine learning approach to information fusion for combining heterogeneous genomic data. The algorithm uses an unsupervised joint learning mechanism that identifies clusters of genes using the combined data. Results: The correlation between gene expression time-series patterns obtained from different experimental conditions and the presence of several distinct and repeated motifs in their upstream sequences is examined here using publicly available yeast cell-cycle data. The results show that the combined learning approach taken here identifies correlated genes effectively. The algorithm provides an automated clustering method, but allows the user to specify apriori the influence of each data type on the final clustering using probabilities. Availability: Software code is available by request from the first author. Contact: jkasturi@cse.psu.edu
Regio- and Enantioselective Synthesis of Pyrrolidines Bearing a Quaternary Center by Palladium-Catalyzed Asymmetric [3 + 2] Cycloaddition of Trimethylenemethanes

Herein we describe the first use of disubstituted donors in the palladium-catalyzed trimethylenemethane (TMM) cycloaddition resulting in an enantioselective synthesis of highly substituted pyrrolidines. These cyanoalkyl donors 1 form all-carbon quaternary centers in a catalytic, asymmetric, and intermolecular manner uniquely using diamidophosphite ligands L2 and L3, generating synthetically important chiral building blocks in good yields and selectivities.
How Standardized Is Accounting

ABSTRACT There is disagreement in the accounting community about what level of standardization would be efficient for accounting. Many of the known costs and benefits of standardization have gone unmeasured and, as a result, there have been no efforts to quantitatively identify an efficient level of accounting standardization. Without guidance from researchers, the level of accounting standardization is set according to the intuition of standard-setters. Using data on a large cross-section of occupations, I provide evidence that the level of standardization in financial reporting occupations is far higher than would be expected given their characteristics. I then show with time-series data that the breadth of professional accounting discourse declined during the late 20th century, coincident with increases in the output of standard-setters. A lower quality discourse is one of many possible consequences of inefficient standardization. Data Availability: Occupations data in the O*NET, Career One Stop, and O...
Ferrocenyl bis-phosphine ligands bearing sulfinyl, sulfonyl or sulfenyl groups: applications in asymmetric hydrogenation and allylic alkylation reactions

Abstract A new series of chiral ferrocenyl bis-phosphine ligands have been synthesized. Elements of planar and central chirality have been incorporated into a ferrocene backbone through sulfinyl, sulfonyl and sulfenyl groups at the ortho-position to the phosphines. The effectiveness of these ligands has been demonstrated in Rh-catalyzed hydrogenations and Pd-catalyzed allylic alkylations.
Cryptographic Hardness Based on the Decoding of Reed–Solomon Codes

In this paper, we investigate the decoding problem of Reed-Solomon (RS) codes, also known as the polynomial reconstruction problem (PR), from a cryptographic hardness perspective. Namely, we deal with samplable PR instances over parameter choices for which decoding is not known to be feasibly solvable and where part of the solution polynomial is the hidden input. We put forth a natural decisional intractability assumption that relates to this decoding problem: distinguishing between a single randomly chosen error location and a single randomly chosen nonerror location for a given corrupted RS codeword with random noise. We prove that under this assumption, PR instances are entirely pseudorandom, i.e., they are indistinguishable from random vectors over the underlying finite field. Moreover, under the same assumption, we show that it is hard to extract any partial information related to the hidden input encoded by the corrupted PR instance, i.e., PR instances hide their message polynomial solution in the semantic security sense. The above results lay a framework for the exploitation of PR as an intractability assumption for provable security of cryptographic primitives. Based on this framework, we present provably secure cryptographic constructions for (1) a pseudorandom number generator, (2) a semantically secure version of the oblivious polynomial evaluation (OPE) protocol, and (3) a stateful cipher with a set of interesting properties that include: semantic security, forward secrecy, error-correcting decryption and an array of random self-reducibility properties with respect to the plaintext choice, key choice, and partial domain choice.
Cu-catalyzed enantioselective conjugate addition of alkylzincs to cyclic nitroalkenes: Catalytic asymmetric synthesis of cyclic α-substituted ketones

An efficient and highly enantioselective (≥92% ee) catalytic method for conjugate addition of alkylzinc reagents to cyclic nitroalkenes is reported. Reactions are promoted in the presence of 0.5−5 mol % (CuOTf)2·C6H6 and 1−10 mol % of chiral amino acid-based phosphine ligands at 0 °C in toluene. The Cu-catalyzed reactions can be effectively carried out with small-, medium-, and large-ring nitroalkenes. Depending on the reaction conditions used, either the nitro or the corresponding α-substituted ketone product can be readily accessed by the present protocol.
Immediate intraoperative tissue expansion

We report a modification of the controlled tissue expansion technique, that is, immediate intraoperative tissue expansion. The procedure is performed by placing tissue expanders at the time of surgery. After placement, three to four cycles of inflation/deflation of the expander for 3 to 5 minutes are performed. In a one-stage procedure the stretched skin is then immediately used to close the surgical defect. Three case reports demonstrating the immediate intraoperative tissue expansion technique, in which the Foley catheter balloon was used as the tissue expander, are presented. These cases illustrate that this technique may allow the surgeon to cover defects more easily with less tension and with a better cosmetic result than with other closure techniques.
Performance improvement in decentralized adaptive control: a modified model reference scheme

A modified decentralized model reference adaptive controller is proposed for a continuous time large scale system composed of N interconnected linear subsystems with unknown parameters. In the case where the high frequency gain of the transfer function of each of the isolated subsystems is known, the modified scheme can be used to improve the bad transient behaviour that typically results from poor knowledge of the subsystem parameters. The transient performance improvement, however, has to be traded off against the "size" of the allowable unmodeled interconnections in such a way that as the unmodeled interconnections disappear, the improvement in transient performance can be made arbitrary. Each local adaptive scheme uses "approximate differentiators," and so possible sensor noise amplification is expected to be an additional limitation of the proposed scheme. >
An Invariant of Smooth 4{Manifolds

We dene a dieomorphism invariant of smooth 4{manifolds which we can estimate for many smoothings of R 4 and other smooth 4{manifolds. Using this invariant we can show that uncountably many smoothings of R 4 support no Stein structure. Gompf [11] constructed uncountably many smoothings of R 4 which do support Stein structures. Other applications of this invariant are given.
Synthesis, Densification, and Conductivity Characteristics of BICUVOX Oxygen‐Ion‐Conducting Ceramics

Copper-substituted bismuth vanadate (Bi2V0.9Cu0.1O5.35), known as BICUVOX, possesses high oxygen ion conductivities at low temperatures. The ionic conductivity of this material at 300°C (∼1 × 10−3 S/cm) is 50 to 100 times greater than any other solid electrolyte in this temperature range. In this paper we report the preparation of sinterable BICUVOX powders by solid-state reaction and conventional ceramic powder processing techniques. Densification studies indicate that optimum densities (>95% theoretical) can be obtained after 10-20 h sintering at 800°C. Ionic conductivity characteristics were evaluated with respect to temperature, sample density, and prolonged isothermal heating.
Enantioselective Reduction of Ketones and Imines Catalyzed by (CN‐Box)ReV–Oxo Complexes

enantioselective reduction · hydrosilylation · rearrangement · rhenium Abstract: The development and application of chiral, non-racemic Re V -oxo com- plexes to the enantioselective reduction of prochiral ketones is described. In addi- tion to the enantioselective reduction of prochiral ketones, we report the applica- tion of these complexes to 1) a tandem Meyer-Schuster rearrangement/reduction to access enantioenriched allylic alcohols and 2) the enantioselective reduction of imines.
Fuzzy Bags and Wilson Lines

I start with an elementary observation about the pressure in the deconfined phase of a SU(3) gauge theory without quarks. This suggests a ``fuzzy'' bag model for the analogous pressure in QCD, with dynamical quarks. I then sketch how the deconfined phase might be described using an effective theory of Wilson lines. To leading order in weak coupling, the effective electric field appears in a form familiar from the lattice theory of Banks and Ukawa.
Distance, Time, and Specialization

Time is money, and distance matters. We model the interaction of these truisms, and show the implications for global specialization and trade: products where timely delivery is important will be produced near the source of final demand, where wages will be higher as a result. In the model, timely delivery is important because it allows retailers to respond to fluctuating final demand without holding costly inventories, and timely delivery is only possible from nearby locations. Using a unique dataset that allows us to measure the retail demand for timely delivery, we show that the sources of US apparel imports have shifted in the way predicted by the model, with products where timeliness matters increasingly imported from nearby countries.