cssi/SciSciGPT-SciSciNet huggingface dataset:
Global emission projections for the transportation sector using dynamic technology modeling

Abstract. In this study, global emissions of gases and particles from the transportation sector are projected from the year 2010 to 2050. The Speciated Pollutant Emission Wizard (SPEW)-Trend model, a dynamic model that links the emitter population to its emission characteristics, is used to project emissions from on-road vehicles and non-road engines. Unlike previous models of global emission estimates, SPEW-Trend incorporates considerable detail on the technology stock and builds explicit relationships between socioeconomic drivers and technological changes, such that the vehicle fleet and the vehicle technology shares change dynamically in response to economic development. Emissions from shipping, aviation, and rail are estimated based on other studies so that the final results encompass the entire transportation sector. The emission projections are driven by four commonly-used IPCC (Intergovernmental Panel on Climate Change) scenarios (A1B, A2, B1, and B2). With global fossil-fuel use (oil and coal) in the transportation sector in the range of 128–171 EJ across the four scenarios, global emissions are projected to be 101–138 Tg of carbon monoxide (CO), 44–54 Tg of nitrogen oxides (NOx), 14–18 Tg of non-methane total hydrocarbons (THC), and 3.6–4.4 Tg of particulate matter (PM) in the year 2030. At the global level, a common feature of the emission scenarios is a projected decline in emissions during the first one or two decades (2010–2030), because the effects of stringent emission standards offset the growth in fuel use. Emissions increase slightly in some scenarios after 2030, because of the fast growth of on-road vehicles with lax or no emission standards in Africa and increasing emissions from non-road gasoline engines and shipping. On-road vehicles and non-road engines contribute the most to global CO and THC emissions, while on-road vehicles and shipping contribute the most to NOx and PM emissions. At the regional level, Latin America and East Asia are the two largest contributors to global CO and THC emissions in the year 2010; this dominance shifts to Africa and South Asia in the future. By the year 2050, for CO and THC emissions, non-road engines contribute the greatest fraction in Asia and the former USSR, while on-road vehicles make the largest contribution in Latin America, Africa, and the Middle East; for NOx and PM emissions, shipping controls the trend in most regions. These forecasts include a formal treatment of the factors that drive technology choices in the global vehicle sector and therefore represent a robust and plausible projection of what future emissions may be. These results have important implications for emissions of gases and aerosols that influence air quality, human health, and climate change.
A Bayesian Vector Multidimensional Scaling Procedure Incorporating Dimension Reparameterization with Variable Selection

We propose a two-way Bayesian vector spatial procedure incorporating dimension reparameterization with a variable selection option to determine the dimensionality and simultaneously identify the significant covariates that help interpret the derived dimensions in the joint space map. We discuss how we solve identifiability problems in a Bayesian context that are associated with the two-way vector spatial model, and demonstrate through a simulation study how our proposed model outperforms a popular benchmark model. In addition, an empirical application dealing with consumers’ ratings of large sport utility vehicles is presented to illustrate the proposed methodology. We are able to obtain interpretable and managerially insightful results from our proposed model with variable selection in comparison with the benchmark model.
Tax law changes, income-shifting and measured wage inequality: Evidence from India☆

Abstract We examine the effects of a 1992 income tax law change in India that eliminated the tax penalty on wages paid to partners in partnership firms using a large dataset covering all registered plants in the manufacturing sector over the period 1986 to 1995. This tax law change provides a unique opportunity to identify the effects of tax policy changes on firm behavior in a developing country context. We find an immediate and pervasive response by partnership firms to the tax law change, reflected in a significant shifting of income from profits to managerial wages. Because about 50% of registered manufacturing plants operate in the form of partnerships (including most family-run businesses), income-shifting by these firms could have a significant impact on measured wage inequality. We find a sizeable jump in the mean and median relative wage of skilled workers (which includes managers and partners) following the tax law change in 1992. Although this sudden increase in measured wage inequality follows major trade liberalization and deregulation reforms announced earlier (in July 1991), we find that the income-shifting induced by the tax law change explains almost all of the observed increase in measured wage inequality following these reforms. This finding is robust to inclusion of controls for a number of other potential sources of post-liberalization increases in wage inequality. Our results show that firms respond strongly to tax incentives for income-shifting, and highlight the need to control for the potential effects of tax incentives in studies of wage inequality. Because wages received by partners were reported as business income on tax returns, the finding of an increasing share of top wage earners in total wages in India in the 1990s, documented by Banerjee and Piketty [Banerjee, Abhijit, and Thomas Piketty. 2005. “Top Indian Incomes, 1922–2000.” The World Bank Economic Review 19 (1): 1–20.] using tax return data, is unlikely to be much affected by the tax reform we analyze here.
A control engineering model of calcium regulation

Abstract The objective of this work is to develop a comprehensive computational model that will enable quantitative understanding of plasma calcium regulation under normal and pathological conditions. Ca regulation is represented as an engineering control system where physiological sub-processes are mapped onto corresponding block components, and underlying mechanisms represented by differential equations. The resulting model is validated with clinical observations of induced hypo- or hypercalcemia in healthy subjects, and its applicability demonstrated by comparing model predictions of Ca-related pathologies to corresponding clinical data. Our model accurately predicts clinical responses to induced hypo- and hypercalcemia in healthy subjects within a framework that facilitates the representation of Ca-related pathologies in terms of control system component defects. The model also enables a deeper understanding of the emergence of pathologies and the testing of hypotheses about related features of Ca regulation, for example, why Primary Hyperparathyroidism (PHPT) and Hypoparathyroidism (HoPT) arise from “controller defects”. The control engineering framework provides an efficient means of organizing the sub-processes constituting Ca regulation, thereby facilitating a fundamental understanding of this complex process. The resulting validated model's predictions are consistent with clinically observed short- and long-term dynamic characteristics of the Ca regulatory system in both healthy and diseased patients. The model also enables simulation of currently infeasible clinical tests, and generates predictions of physiological variables that are currently not measurable.
Manufactured Aluminum Oxide Nanoparticles Decrease Expression of Tight Junction Proteins in Brain Vasculature

Manufactured nanoparticles of aluminum oxide (nano-alumina) have been widely used in the environment; however, their potential toxicity provides a growing concern for human health. The present study focuses on the hypothesis that nano-alumina can affect the blood-brain barrier and induce endothelial toxicity. In the first series of experiments, human brain microvascular endothelial cells (HBMEC) were exposed to alumina and control nanoparticles in dose- and time-responsive manners. Treatment with nano-alumina markedly reduced HBMEC viability, altered mitochondrial potential, increased cellular oxidation, and decreased tight junction protein expression as compared to control nanoparticles. Alterations of tight junction protein levels were prevented by cellular enrichment with glutathione. In the second series of experiments, rats were infused with nano-alumina at the dose of 29 mg/kg and the brains were stained for expression of tight junction proteins. Treatment with nano-alumina resulted in a marked fragmentation and disruption of integrity of claudin-5 and occludin. These results indicate that cerebral vasculature can be affected by nano-alumina. In addition, our data indicate that alterations of mitochondrial functions may be the underlying mechanism of nano-alumina toxicity.
Structural studies of a cubic, high-temperature (α) polymorph of Pb2GeS4 and the isostructural Pb2−xSnxGeS4−ySey solid solution

Abstract We have synthesized and characterized a high-temperature, cubic polymorph of Pb 2 GeS 4 , whose existence had been noted by Moh [N. Jb. Miner. Abh. 128 (1976) 115] and Elli and Mugnoli [Rend. Sci. Fis. Mat. Nat. 33 (1962) 315], but whose structure has not yet been reported. Synthesized directly from the elements, α-Pb 2 GeS 4 and members of the Pb 2− x Sn x GeS 4− y Se y solution (0≤ x ≤0.5, 0≤ y ≤4) form in the non-centrosymmetric space group I 4 3d , with Z=16 and lattice parameters ranging from a=14.103 A for the red α -Pb 2 GeS 4 phase, to a=14.573 A for the dark-grey Pb 2 GeSe 4 phase. These compounds contain isolated [Ge(S,Se)] 4− tetrahedra and two different sites for the metal counter-cations. Confirming the non-centrosymmetric nature of their structures, α-Pb 2 GeS 4 and Pb 2 GeSe 4 show weak second harmonic generation responses when irradiated with 1064-nm laser light.
Towards scarless surgery: an endoscopic ultrasound navigation system for transgastric access procedures.

Objective: Scarless surgery is an innovative and promising technique that may herald a new era in surgical procedures. We have created a navigation system, named IRGUS, for endoscopic and transgastric access interventions and have validated it in in vivo pilot studies. Our hypothesis is that endoscopic ultrasound procedures will be performed more easily and efficiently if the operator is provided with approximately registered 3D and 2D processed CT images in real time that correspond to the probe position and ultrasound image.Materials and Methods: The system provides augmented visual feedback and additional contextual information to assist the operator. It establishes correspondence between the real-time endoscopic ultrasound image and a preoperative CT volume registered using electromagnetic tracking of the endoscopic ultrasound probe position. Based on this positional information, the CT volume is reformatted in approximately the same coordinate frame as the ultrasound image and displayed to the operat...
Measurement of extinction coefficients of laser-produced aluminum plumes

Radial spectral intensities (0.632 yum) were measured using a He:Ne probe laser scanning an aluminum plume formed by Ndiglass laser irradiation of a target surface. Furthermore, techniques were developed to measure the radial distributions of the extinction coefficients in an axisymmetric, laser-produced aluminum plume. The techniques developed allow for measurements of these distributions as functions of time, wavelength, and elevation above the aluminum target. The extinction coefficients determine the ability of the plasma to attenuate incident laser radiation. The extinction coefficient distribution was determined by scanning a He:Ne probe laser through the plume and converting line-of-sight measurements to a radial distribution. Results indicate that the aluminum plume is optically thin in the first 80 /*s after formation and that the radial extinction coefficient profile has a Gaussian distribution.
An interacting parton model for quark and anti-quark distributions in the baryon

Abstract In this paper we study a 1+1 dimensional relativistic parton model for the structure of baryons. The quarks and anti-quarks interact through a linear potential. We obtain an analytic formula for the isospin averaged valence quark distribution in the chiral and large Nc limits. The leading 1 N c and non-zero current quark mass corrections are estimated. Then we extend this model to include `sea' and anti-quarks. We find that the anti-quark content is small at a low value of Q2. Using these distributions as initial conditions for Q2 evolution, we compare with experimental measurements of the structure function xF3(x,Q2) and find reasonable agreement. The only parameters we can adjust are the fraction of baryon momentum carried by valence quarks and the initial scale Q02.
EFFECT OF DOSING FREQUENCY ON CHRONIC CARDIOVASCULAR DISEASE MEDICATION ADHERENCE

AbstractBackground:Many cardiovascular diseases (CVDs) require patients to take one or more long term medications, often administered multiple times a day. We sought to determine the effect of chronic CVD medication dosing frequency on medication adherence.Methods:A search of Medline and Embase from 1986 to December 2011 was performed. Included studies used a prospective design, assessed adults with chronic CVDs, evaluated scheduled oral medications administered one to four times daily, and measured adherence for ≥1 month using an electronic monitoring device. Mixed linear model meta-regression was used to determine how dosing frequency affected adherence using three definitions of increasing strictness: taking, regimen and timing adherence.Results:A total of 29 studies, comprising 41, 29, and 27 dosing frequency arms for the taking, regimen and timing adherence definitions were included. Crude pooled adherence estimates were highest when the lenient taking definition was assessed (range for dosing freque...
Tiling space and slabs with acute tetrahedra

We show it is possible to tile three-dimensional space using only tetrahedra with acute dihedral angles. We present several constructions to achieve this, including one in which all dihedral angles are less than 74.21°, and another which tiles a slab in space.
Comments on domain walls in holographic duals of mass deformed conformal field theories

We consider M-theory backgrounds which are gravity duals of mass deformed superconformal field theories in 2 + 1 dimensions. The specific examples we consider are the B8, Stenzel, and the Lin-Lunin-Maldacena geometries. These geometries contain compact 4-cycles on which one can wrap an M5-brane to create an object which behaves effectively like a domain wall in 2 + 1 dimensions. We review the quantization of flux and charges of these M-theory backgrounds, and confirm that the back reaction of the domain wall shifts the charges in a manner consistent with these quantization conditions, paying particular attention to various subtle half integer shifts of the charge lattice which arise as a part of the complete story. We also describe a configuration of a stationary, merging M2/anti M2 pair in the Lin-Lunin-Maldacena background, which can also be interpreted as a domain wall, and compare its basic properties with the expectations from its field theory description.
Vibrations of a Row of Circular Cylinders in a Liquid

The effects of interaction with surrounding liquid on the dynamic behavior of a row of circular cylinders were studied analytically. The hydrodynamic forces associated with cylinder motions were obtained using the potential flow theory and a method of solution is presented for free and forced vibrations of a row of cylinders. The results of this study have important application in the modeling of crossflow-induced vibration of heat-exchanger tubes. (auth)
Synthesis of unsaturated esters from aldehydes: An inexpensive, practical alternative to the Horner-Emmons reaction under neutral conditions

A practical, efficient, and mild process is described for the synthesis of unsaturated esters from aldehydes in good yields and diastereoselectivities. All of the reagents used in the protocol are commercially available at a nominal price: N2CHCO2Et, catalytic (1 mol%) ReOCl3(PPh3)2, and (EtO)3P. Additionally, the reaction process can be carried out successfully in good yields (85%) and diastereoselectivities (>20:1) with reagent-grade solvent without prior purification of the reagents.
Speech recognition using hidden Markov models: a CMU perspective

Abstract Hidden Markov Models (HMMs) have become the predominant approach for speech recognition systems. One example of an HMM-based system is SPHINX , a large-vocabulary, speaker-independent, continuous-speech recognition system developed at CMU. In this paper, we introduce Hidden Markov Modelling techniques, analyze the reason for their success, and describe some improvements to the standard HMM used in SPHINX .
Some past achievements and future perspectives in main group chemistry

A survey of some recent developments and past achievements in low-valent main group chemistry is presented. Some emerging implications of this area of chemistry in materials science, catalysis and new reagent development are also discussed.
A harmonic model of hydrodynamic forces produced by a flapping fin

The hydrodynamic control laws of unsteady fins inspired by swimming and flying animals are considered. A controller based on cycle-averaged forces requires a bandwidth lower than the flapping frequency, with correspondingly slow reactions to disturbances or commands in order to avoid undesirable feedback from the oscillating fins. A harmonic model of the periodic thruster forces was empirically found using a mechanical fin flapping in roll and pitch in hover, in uniform flow, and under various kinematic conditions. A multi-fin vehicle could use this model to account for the dominant non-linearities and minimize undesirable motions through coordinated control of individual fins.
Endogenous technological change and international technology transfer in a Ricardian trade model

Abstract The study uses a Ricardian model (two goods, two countries, one factor) to analyze the interdependence of technology creation and the conditions of international technology transfer. Costly R&D, performed in a third sector in the home country, yields process-improving new technology, an intermediate public good. The level of R&D depends on the value of domestic and foreign royalties accruing to this sector. The levels of national welfare are related to various conditions of transfer, including no transfer, free transfer, globally optimal royalties, and nationally optimal royalties.
Spectral Beam Combining of Yb-doped Fiber Lasers in an External Cavity

The outputs of two fiber lasers have been combined in an external cavity. This proof-of-concept demonstration shows the feasibility of beam combining many (tens to hundreds) fiber gain elements.
Costly Search, Capacity Constraints, and Bertrand Equilibrium Price Dispersion

This article analyzes the impact of transaction (search) costs and capacity constraints in an almost competitive market with homogeneous firms that compete on price. We characterize conditions under which Nash equilibria with price dispersion exist; in equilibrium, firms play pure strategies in prices and consumers adopt a symmetric mixed search strategy. Price dispersion is possible even though consumers all have the same search cost and valuation for the item and prices charged by all firms are common knowledge.
Deep postoperative wound infection after carpal tunnel release

Between January 1976 and December 1985, 3620 carpal tunnel releases were done at the Mayo Clinic. A deep postoperative infection developed in 17 (0.47%) patients. These 17 were compared with a control group of 102 patients to identify possible risk factors. Statistically significant risk factors included intraoperative instillation of steroid solution into the carpal canal, flexor tendon synovectomy, prolonged operative time, and use of a surgical drain. Infection incidence was 0.87% in males and 0.25% in females (statistically significant). Seven (41%) of the 17 patients had a suboptimal result at final follow-up.
Effect of model error on sensor placement for on-orbit modal identification of large space structures

A theory is presented for the effect of errors in large space structure prelaunch finite element models on sensor placement for the on-orbit independent identification of a set of selected target modes. The idea of positive net information is introduced. If the net information matrix remains positive definite as sensor locations are deleted from an initial candidate set, the analytical model provides useful information for the identification of the real target modes. If the net information matrix becomes indefinite, the sensor placement analysis based on the prelaunch analytical model will actually detract from the independent identification of the target modes. A bound is presented that can be easily checked after each iteration during which a sensor was deleted to determine positive definiteness of the net information matrix. Numerical examples are used to illustrate the ideas that are presented.
The Sleeper Effect of Intimate Partner Violence Exposure: Long-Term Consequences on Young Children's Aggressive Behavior.

BACKGROUND: Children who have been exposed to intimate partner violence (IPV) experience a wide variety of short-term social adjustment and emotional difficulties, including externalizing behavioral problems such as aggression. While children are affected by IPV at all ages, little is known about the long-term consequences of IPV exposure at younger ages. Because early experiences provide the foundation for later development, children exposed to IPV as an infant or toddler may experience worse negative outcomes over time than children never exposed. METHODS: Using the National Survey of Child and Adolescent Well-Being (NSCAW), latent growth curve modeling was conducted to examine whether early IPV exposure occurring between birth and age three (n = 107), compared with no exposure (n = 339), affects the development of aggressive behavior over 5 years. This modeling allowed for empirical exploration of developmental trajectories, and considered whether initial social development trajectories and change over time vary according to early IPV exposure. RESULTS: Children who were exposed to more frequent early IPV did not have significantly different aggressive behavior problems initially than children who were never exposed. However, over time, the more frequently children were exposed between birth and 3 years, the more aggressive behavior problems were exhibited by age eight. CONCLUSIONS: Results indicate a long-term negative behavioral effect on children who have been exposed to IPV at an early age. An initial assessment directly following exposure to IPV may not be able to identify behavior problems in young children. Because the negative effects of early IPV exposure are delayed until the child is of school age, early intervention is necessary for reducing the risk of later aggressive behavior. Language: en
Convenient Preparation of a Cyclopropanation Reagent: α-Siloxymethyliron Complex

Abstract A convenient preparation of α-siloxymethyliron complex (7) was developed from commercially available s-trioxane and/or paraformaldehyde. For synthetic utility, iron methylidene complex (8) was generated in situ from the α-siloxymethyliron complex (7) and cyclopropanes (10) by treatment with alkenes.
Influence of two-phase thermocapillary flow on liquid retention in microscopic pores

An important feature of screened propellant acquisition devices is the retention capability or maximum maintainable pressure difference across the porous barrier separating the liquid and gas. Previous experiments with liquid hydrogen showed a marked reduction in retention when the tank containing the device was pressurized with hydrogen vapor. These tests, however did not indicate any appreciable degradation in retention with helium pressurization or direct heating through the screen. The objective of this article is to determine if the thermocapillary convection arising from phase change in the microscopic pores of such screens could cause these disparities in performance. A numerical model of flow in a single pore suggests that the thermocapillary-induced gradient in liquid pressure along the surface can strongly affect surface morphology. In an evaporative environment, this gradient exerts a stabilizing influence on surface curvature, and preserves the momentum balance between the liquid and gas. With condensation, it causes a force imbalance and a destabilizing suction in the middle of the pore that reduces retention. Results also indicate that introducing an inert gas, such as helium, suppresses this retention loss mechanism by lowering thermocapillary circulation and its associated interfacial pressure gradient.
Bound states of negative pions and neutrons

By use of standard forms for the various interactions of a system of N neutrons and Z negative pions, it is shown that for a large variety of values of N and Z the system can become bound. This gives rise to a structure similar to that of an ordinary nucleus, but in which the protons are replaced by negative pions.
Abundances of 30 elements in 23 metal-poor stars

We report the abundances of 30 elements in 23 metal-poor ([Fe/H] < -1.7) giants. These are based on 7774 equivalent widths and spectral synthesis of 229 additional lines. Hyperfine splitting is taken into account when appropriate. Our choice of model atmospheres has the most influence on the accuracy of our abundances. We consider the effect of different model atmospheres on our results. In addition to the random errors in Teff, log g, and microturbulent velocity, there are several sources of systematic error. These include using Teff determined from Fe I lines rather than colors, ignoring non-LTE effects on the Fe I/Fe II ionization balance, using models with solar [α/Fe] ratios, and using Kurucz models with overshooting. Of these, only the use of models with solar [α/Fe] ratios had a negligible effect. However, while the absolute abundances can change by greater than 0.10 dex, the relative abundances, especially between closely allied atoms such as the rare earth group, often show only small (less than 0.03 dex) changes. We found that some strong lines of Fe I, Mn I, and Cr I consistently gave lower abundances by ~0.2 dex, a number larger than the quoted errors in the gf-values. After considering a model with depth-dependent microturbulent velocity and a model with hotter temperatures in the upper layers, we conclude that the latter did a better job of resolving the problem and agreeing with observational evidence for the structure of stars. The error analysis includes the effects of correlation of Teff, log g, and ξ errors, which is crucial for certain element ratios, such as [Mg/Fe]. The abundances presented here are being analyzed and discussed in a separate series of papers.
Understanding cardinality estimation using entropy maximization

Cardinality estimation is the problem of estimating the number of tuples returned by a query; it is a fundamentally important task in data management, used in query optimization, progress estimation, and resource provisioning. We study cardinality estimation in a principled framework: given a set of statistical assertions about the number of tuples returned by a fixed set of queries, predict the number of tuples returned by a new query. We model this problem using the probability space, over possible worlds, that satisfies all provided statistical assertions and maximizes entropy. We call this the Entropy Maximization model for statistics (MaxEnt). In this article we develop the mathematical techniques needed to use the MaxEnt model for predicting the cardinality of conjunctive queries.
Factorizations of Polynomials over Noncommutative Algebras and Sufficient Sets of Edges in Directed Graphs

To directed graphs with unique sink and source we associate a noncommutative associative algebra and a polynomial over this algebra. Edges of the graph correspond to pseudo-roots of the polynomial. We give a sufficient condition when coefficients of the polynomial can be rationally expressed via elements of a given set of pseudo-roots (edges). Our results are based on a new theorem for directed graphs also proved in this paper.
Arc spaces and DAHA representations

A theorem of Y. Berest, P. Etingof and V. Ginzburg states that finite-dimensional irreducible representations of a type A rational Cherednik algebra are classified by one rational number m/n. Every such representation is a representation of the symmetric group Sn. We compare certain multiplicity spaces in its decomposition into irreducible representations of Sn with the spaces of differential forms on a zero-dimensional moduli space associated with the plane curve singularity xm = yn.
Concealed-gun-carrying laws and violent crime: evidence from state panel data

Abstract A recent study concludes that permissive concealed-handgun-carrying (or “shall-issue”) laws have sharply reduced crime rates, including the rate of homicide. The method of the study has been critiqued by several authors. In this paper, I report a quite different approach that exploits the minimum age requirements for concealed-carry permits to more effectively control for unobserved variables that may vary over time. Because even permissive concealed-carry states require permit holders to meet minimum age requirements, any deterrent benefits from these laws should be concentrated among adults and, therefore, should be reflected in the gap between adult and juvenile victimization rates. My results suggest that shall-issue laws have resulted, if anything, in an increase in adult homicide rates.
Enhancing the Ion-Transport Selectivity of Multilayer Polyelectrolyte Membranes

Alternating adsorption of polycations and polyanions on permeable supports provides a convenient and versatile method for preparing composite membranes with selective, ultrathin polyelectrolyte skins. Control over charge and composition in the polyelectrolyte skin allows highly selective separation of ions according to charge, size, or hydration energy.
The rate of growth of the minimum clique size of graphs of given order and chromatic number

Let Q ( n , c ) denote the minimum clique number over graphs with n vertices and chromatic number c . We determine the rate of growth of the sequence { Q ( n , ? r n ? ) } n = 1 ∞ for any fixed 0 < r ? 1 . We also give a better upper bound for Q ( n , ? r n ? ) .
Dynamics of Dirichlet-Neumann open strings on D-branes

Abstract A method for computing scattering amplitudes of open strings with a Dirichlet boundary on one end and a Neumann boundary condition on the other is described. The vertex operators for these states are constructed using twist fields which have been studied previously in the context of the Ashkin-Teller model and strings on orbifolds. Using these vertex operators, we compute the three- and four-point scattering amplitudes for (5,9) strings on 5-branes and 9-branes. In the low-energy limit, these amplitudes are found to be in exact agreement with the field theory amplitudes for supersymmetric Yang-Mills coupled to hypermultiplets in six dimensions. We also consider the 1-brane 5-brane system and compute the amplitude for a pair of (1,5) strings to collide and to escape the brane as a closed string. (1,5) strings are found to be remarkably selective in their coupling to massless closed strings in the NS-NS sector; they only couple to the dilaton.
Preparation and synthetic utility of oxasilacyclopentane acetals derived from siliranes

Abstract The insertion of formamides into a CSi bond of silirane trans-1 provides a facile route to the oxasilacyclopentane acetate 5 (86% overall yield). Stereoselective carbon-carbon bond formation on the derived oxonium ion was achieved by addition of the silyl enol ether of acetophenone (92:8 selectivity, 79% yield) and 3-pentanone (92:5:3 selectivity, 100% yield). These results demonstrate the potential of siliranes as intermediates in organic synthesis.
On the measurement of true fracture strain of thermoplastics materials

In tensile testing, engineering thermoplastic materials can sustain large deformation after necking. This property can be advantageous to the manufacturing process and mechanical performance. However, it causes difficulties in strain measurement and in the determination of true stress and true strain, particularly at higher strain rates. This paper discussed the measurement of true fracture strain. The true fracture strain was estimated using three different methods: the area reduction, elongation over the necked zone, and elongation over the gage length. With strain localization, strain measured by an extensometer becomes gage length dependent. To address the issue, an algorithm was formulated that estimates the average fracture strain over an arbitrary gage length from the fracture strain measured over the necked zone. The proposed algorithm provides a way to estimate the mesh dependence of the fracture strain for finite element (FE) analysis. This paper also presents an analysis-based two-step correction scheme for the crosshead extension to be used to supplement the strain measurement from the extensometer.
Wiggler taper optimization for free electron laser amplifiers with moderate space-charge effects

Abstract The standard synchronous tapering method used to design the wiggler magnetic field for free electron laser (FEL) amplifiers operating in the Compton regime will not work for amplifier systems where space-charge effects are important. The space-charge effects lower the overall gain in the amplifier system and, even more importantly, shift the peak in the gain curve to magnetic field values that are significantly less than the synchronous magnetic field value. As a result, the overall predicted gain using the synchronous tapering method is too low. Moreover, the synchronous magnetic field corresponds to the peak in the gain curve for a frequency below the fundamental frequency. Consequently, shot noise at frequencies below the fundamental frequency can grow to levels that may prevent amplification of the fundamental. We have developed a new tapering strategy that improves the predicted amplifier gain and circumvents the shot-noise growth for systems with moderate space-charge effects. For this new strategy, we hold the wiggler magnetic field constant at a value below the synchronous value but near the peak of the gain curve for the fundamental frequency, for some optimized length at the front end of the wiggler. Beyond this constant wiggler section, the field is tapered using the standard synchronous tapering algorithm. This new tapering scheme results in significant improvement in predicted amplifier gains and limits the growth of shot noise to insignificant levels. We demonstrate the effectiveness of this new tapering algorithm using the tapered wiggler design for the proposed microwave heating experiment (MTX) at the Lawrence Livermore National Laboratory (LLNL).
Information and volatility linkages in the stock, bond, and money markets

Abstract We investigate the nature of volatility linkages in the stock, bond, and money markets. We develop a simple model of speculative trading that predicts strong volatility linkages in these markets due to common information, which simultaneously affects expectations across markets, and information spillover caused by cross-market hedging. To measure these linkages, we estimate a stochastic volatility representation of our trading model using GMM. The results indicate that our specification explains many of the observed characteristics of the data, and that the volatility linkages between the three markets are indeed strong. Moreover, we find that the linkages have become stronger since the 1987 stock market crash.
Transport through quantum dots: analytic results from integrability.

Recent experiments have probed quantum dots through transport measurements in the regime where they are described by a two lead Anderson model. In this paper we develop a new method to analytically compute the corresponding transport properties. This is done by using the exact solvability of the Anderson Hamiltonian, together with a generalization of the Landauer-B\"uttiker approach to integrable systems. In the Kondo regime, we compute analytically for the first time the zero-field, finite temperature linear response conductance, as well as giving closed form expressions describing the zero-temperature, nonequilibrium conductance in an applied Zeeman field.
Axion monodromy in a model of holographic gluodynamics

The low energy field theory for N type IIA D4-branes at strong ’t Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the θ angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of “axion monodromy” for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of θ. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with θ, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes — nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk — which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings.
Regioselective reaction of allylbenzotriazoles with aldehydes and ketones in the presence of lithium

Abstract The reactions of α- and γ-substituted allylbenzotriazoles 2, 3 and 4 with an excess of lithium in THF at −78 °C generate various allyllithiums, which react readily with aldehydes and ketones with high regioselectivity to give predominantly the branched products 5 in excellent yields.
New NP-hard and NP-complete polynomial and integer divisibility problems

Abstract We show that some problems involving sparse polynomials are NP-hard. For example, it is NP-hard to determine if a sparse polynomial has a root of modulus 1, and it is NP-hard to decide if two sparse polynomials are not relatively prime. Also, we show that a divisibility problem involving an unbounded number of sparse polynomials is NP-complete using a theorem of Linnik concerning the distribution of primes in arithmetic sequences. From these results it follows that certain problems involving inequalities, recurrence relations, differential equations, and eigenvalues of sparse matrices are NP-hard. Problems involving divisibility properties of two sparse polynomials, divisibility of sparse binary numbers and ring homomorphisms are also NP-hard.
Sensor network localization using sensor perturbation

Sensor network localization is an instance of the NP-Hard graph realization problem. Thus, methods used in practice are not guaranteed to find the correct localization, even if it is uniquely determined by the input distances.In this article, we show the following: if the sensors are allowed to wiggle, giving us perturbed distance data, we can apply a novel algorithm to realize arbitrary Generically Globally Rigid graphs (GGR), or certain vertex subsets in non-GGR graphs whose relative positions are fixed (which include vertex sets of GGR subgraphs). And this strategy works in any dimension.In the language of structural rigidity theory, our approach corresponds to calculating the approximate kernel of a generic stress matrix for the given graph and distance data. To make our algorithm suitable for real-world applications, we also present: (i) various techniques for improving the robustness of the algorithm in the presence of measurement noise; (ii) an algorithm for detecting certain subsets of graph vertices whose relative positions are fixed in any generic realization of the graph and robustly localizing these subsets of vertices, (iii) a strategy for reducing the number of measurements needed by the algorithm.We provide simulation results of our algorithm.
Eccentricities of Planets in Binary Systems

The most puzzling property of the extrasolar planets discovered by recent radial velocity surveys is their high orbital eccentricities, which are very difficult to explain within our current theoretical paradigm for planet formation. Current data reveal that at least 25% of these planets, including some with particularly high eccentricities, are orbiting a component of a binary star system. The presence of a distant companion can cause significant secular perturbations in the orbit of a planet. At high relative inclinations, large-amplitude, periodic eccentricity perturbations can occur. These are known as “Kozai cycles” and their amplitude is purely dependent on the relative orbital inclination. Assuming that every planet host star also has a (possibly unseen, e.g., substellar) distant companion, with reasonable distributions of orbital parameters and masses, we determine the resulting eccentricity distribution of planets and compare it to observations? We find that perturbations from a binary companion always appear to produce an excess of planets with both very high (≳0.6) and very low (e ≲ 0.1) eccentricities. The paucity of near-circular orbits in the observed sample implies that at least one additional mechanism must be increasing eccentricities. On the other hand, the overproduction of very high eccentricities observed in our models could be combined with plausible circularization mechanisms (e.g., friction from residual gas) to create more planets with intermediate eccentricities (e ≃0.1–0.6).
Moving and ample cones of holomorphic symplectic fourfolds

We analyze the ample and moving cones of holomorphic symplectic manifolds, in light of recent advances in the minimal model program. As an application, we establish a numerical criterion for ampleness of divisors on fourfolds deformation-equivalent to punctual Hilbert schemes of K3 surfaces.
REINVENTING A CORPORATION: THE “SATELLITE” STRUCTURE OF THERMO ELECTRON

Thermo Electron has created a unique–and highly productive—corporate structure by selling to the public minority equity interests in 19 of its business units over the period 1983 to 1996. Since 1983, the company has achieved extraordinary gains for stockholders, both those of the parent company and those of most of its publicly traded subsidiaries. The company's “satellite” structure is intended to preserve the benefits enjoyed by small entrepreneurial organizations without sacrificing many of the advantages enjoyed by larger firms. Although decentralization is a key element of the organizational design, another important feature of the Thermo Electron approach is that administrative activities unrelated to the focus of the unit's operations continue to be managed at the parent level. The combination of an entrepreneurial atmosphere with the financial and administrative support of a larger organization is used extensively by the company to attract and retain management and technical talent. In fact, the company made the remarkable claim in a 1995 Forbes article that “no developer or entrepreneur has ever left Thermo Electron.” Another major contributor to the company's entrepreneurial culture is an incentive structure that is tied directly to the equity performance of both the public units and the parent. Managers of the publicly traded units are granted significant amounts of stock options, but only 40% of those options are based on the performance of their subsidiary. Of the remaining 60%, 40% are granted in the stock of the parent and the other 20% are in stock of the other subsidiaries.
The Standardization of Criteria for Processing and Interpreting Laboratory Specimens in Patients With Suspected Ventilator-Associated Pneumonia

The microbiologic analysis of respiratory specimens is a key component of both the clinical investigation of ventilator-associated pneumonia (VAP) and patient care. Although there is a substantial body of literature on the use of a variety of lower respiratory tract specimens, there is little standardization of the approaches to processing and interpreting results from the various specimens. The purpose of this communication is to delineate specific recommendations for the microbiologic analysis of specimens originating from the lower respiratory tract, as developed by the Laboratory Analysis Group of the Consensus Conference.
Interpretation of pupil aberrations in imaging systems

We show that third-order pupil aberrations in an axially symmetric imaging system represent the basic stretches or deformations that the cross section of a beam can have at the exit pupil.
Evolution of VLSI reliability engineering

Projection indicates that by the turn of the century microcomputer chips will have 100 million transistors and failure rates of less than 10 FIT. Traditional accelerated product life tests and wafer level reliability measurement techniques being developed at present will have severe limitations in resolving the 10 FIT failure rate of complex VLSI circuits. This paper discusses these limitations along with the change in direction that the reliability engineering and manufacturing community will have to take over the next decade to meet the challenge of continuously decreasing failure rate goals.
Multilateral Bargaining with Imperfect Information

Abstract We study a multilateral procedure in which responders are told only their own shares. The proposal becomes common knowledge after the response stage and responders have optimistic beliefs after off-equilibrium offers. When discounting is high, the set of equilibrium agreements is a singleton; when it is low, there is a large multiplicity of equilibrium payoffs. In contrast to earlier work, our multiple equilibria are constructed by using strategy profiles in which a responder rejects any offer that reduces his or her own share. Journal of Economic Literature Classification Numbers: C72 and C78.
A Fluorine-Substituted Hexakisdecyloxy- hexa-peri-hexabenzocoronene

The first fluorine-substituted hexabenzocoronene has been synthesized and is much more readily reduced than its nonfluorinated analogues. Thin films of this material show columnar order at room temperature, and the charge-carrier mobility measured by the pulse-radiolysis time-resolved microwave conductivity technique is comparable to that of other hexabenzocoronene materials.
Nonionic Superbase-Catalyzed Silylation of Alcohols

Herein we report a very effective and mild procedure for the silyl protection of a wide variety of substrate alcohols, including primary, secondary, allylic, propargylic, benzylic, hindered secondary, tertiary, acid-sensitive, and base-sensitive alcohols and also hindered phenols. The silylation reagent used is tert-butyldimethylsilyl chloride (TBDMSCl) and the catalyst is P(MeNCH2CH2)3N, 1b, both of which are commercially available. The reactions are carried out in acetonitrile from 24 to 40 °C and on rare occasions in DMF from 24 to 80 °C. The effect of solvent, catalyst concentration, and temperature and reaction time on the silylation of alcohols and the excellent compatibility of our method with a variety of functional groups is discussed. An efficient method for recycling the catalyst is also presented. Although representative primary alcohols, secondary alcohols, and phenols were silylated using the more sterically hindered reagent tert-butyldiphenylsilyl chloride (TBDPSCl) in the presence of 1b as...