cssi/SciSciGPT-SciSciNet huggingface dataset:
Reactivation of Hepatitis B

Reactivation of hepatitis B refers to the abrupt increase in hepatitis B virus (HBV) replication in a patient with inactive or resolved hepatitis B. Reactivation can occur spontaneously, but more typically is triggered by immunosuppressive therapy of cancer, autoimmune disease, or organ transplantation. Reactivation can be transient and clinically silent, but often causes a flare of disease that can be severe resulting in acute hepatic failure. Most instances of reactivation resolve spontaneously, but if immune suppression is continued, re-establishment of chronic hepatitis occurs which can lead to progressive liver injury and cirrhosis. The best-described instances of reactivation occur in hepatitis B surface antigen (HBsAg) carriers with inactive or minimally active disease who are given cancer chemotherapy for lymphoma or leukemia. Typically, serum HBV DNA rises during chemotherapy, followed by a disease flare and HBV DNA clearance with immune reconstitution after chemotherapy is stopped. Special forms of reactivation occur after solid organ and bone marrow transplantation in which chronic infection often results. Several randomized, placebo-controlled trials have shown that reactivation can be prevented by antiviral prophylaxis. Routine prophylaxis is therefore recommended for persons with HBsAg undergoing cancer chemotherapy or transplantation, but major questions remain. Which patients should be screened for HBsAg and should all be treated? Which antiviral should be used and for how long? Should persons with resolved hepatitis B without HBsAg receive prophylaxis? Future research should address the underlying molecular mechanisms of reactivation as well as its optimal means of diagnosis, treatment, and prevention in different patient populations.
Sum-frequency generation of continuous-wave light at 194 nm

Over 2 mW of continuous-wave tunable 194-nm light is produced by sum-frequency mixing approximately 500 mW of 792-nm and 500 mW of 257-nm radiation in beta-barium borate (BBO). The powers in both fundamental beams are enhanced in separate ring cavities whose optical paths overlap in the Brewster-cut BBO crystal. Due to the higher circulating fundamental powers, the sum-frequency-generated power is nearly 2 orders of magnitude greater than previously reported values.
Deep AutoRegressive Networks

We introduce a deep, generative autoencoder capable of learning hierarchies of distributed representations from data. Successive deep stochastic hidden layers are equipped with autoregressive connections, which enable the model to be sampled from quickly and exactly via ancestral sampling. We derive an efficient approximate parameter estimation method based on the minimum description length (MDL) principle, which can be seen as maximising a variational lower bound on the log-likelihood, with a feedforward neural network implementing approximate inference. We demonstrate state-of-the-art generative performance on a number of classic data sets, including several UCI data sets, MNIST and Atari 2600 games.
Regularization techniques for PSF-matching kernels - I. Choice of kernel basis

We review current methods for building point spread function (PSF)-matching kernels for the purposes of image subtraction or co-addition. Such methods use a linear decomposition of the kernel on a series of basis functions. The correct choice of these basis functions is fundamental to the efficiency and effectiveness of the matching – the chosen bases should represent the underlying signal using a reasonably small number of shapes, and/or have a minimum number of user-adjustable tuning parameters. We examine methods whose bases comprise multiple Gauss–Hermite polynomials, as well as a form-free basis composed of delta-functions. Kernels derived from delta-functions are unsurprisingly shown to be more expressive; they are able to take more general shapes and perform better in situations where sum-of-Gaussian methods are known to fail. However, due to its many degrees of freedom (the maximum number allowed by the kernel size) this basis tends to overfit the problem and yields noisy kernels having large variance. We introduce a new technique to regularize these delta-function kernel solutions, which bridges the gap between the generality of delta-function kernels and the compactness of sum-of-Gaussian kernels. Through this regularization we are able to create general kernel solutions that represent the intrinsic shape of the PSF-matching kernel with only one degree of freedom, the strength of the regularization λ. The role of λ is effectively to exchange variance in the resulting difference image with variance in the kernel itself. We examine considerations in choosing the value of λ, including statistical risk estimators and the ability of the solution to predict solutions for adjacent areas. Both of these suggest moderate strengths of λ between 0.1 and 1.0, although this optimization is likely data set dependent. This model allows for flexible representations of the convolution kernel that have significant predictive ability and will prove useful in implementing robust image subtraction pipelines that must address hundreds to thousands of images per night.
Social Security Contributions and Return Migration Among Older Male Mexican Immigrants

For decades scholars have attempted to understand the effects of immigration on the U.S. Social Security system. To date, this research has been primarily limited to migrants in the U.S. and does not consider those who return to their countries of origin. Immigrants often pay OASDI taxes using illegitimate Social Security numbers and may return to their home countries without collecting U.S. Social Security benefits. In this study, we analyze the socioeconomic and labor characteristics, health, migration histories, and transitions to retirement of male Mexican return migrants who contributed to the U.S. Social Security system. Using the 2003 and 2012 Mexican Health and Aging Study (MHAS), we find that in 2012, 32 percent of male return migrants reported having contributed to the U.S. Social Security system but only five percent of those who contributed, received or expected to receive benefits. Those who reported having contributed were more likely to have completed college, spent more years in the U.S., and were more likely to be U.S. citizens or legal permanent residents than those who did not contribute. We also find that return migrants who spent one to nine years in the U.S. had a lower probability of transitioning to retirement between 2003 and 2012 than those had never been to the U.S. In contrast, those who spent 20 or more years in the U.S. had a higher probability of transitioning to retirement.
ON SUB-MILLIMETER FORCES FROM EXTRA DIMENSIONS

We show that in theories with large extra dimensions forces mediated by a bulk dilaton and bulk gauge fields may be parametrically (exponentially) weaker than gravity due to the suppression of their wave functions on a brane. This is the case when dilaton gets stabilized by certain strongly coupled dynamics on the brane, or the bulk gauge symmetries are spontaneously broken by the Higgs mechanism on the worldvolume. At distances smaller than the size of a largest extra dimension these particles produce the force-law which decreases with distance faster than high-dimensional gravity. For a millimeter size extra dimensions predicted deviations are in the range which may be detected in sub-millimeter gravity measurements.
Stacks of Algebras and Their Homology

For any increasing function \(f: \mathbb{N} \rightarrow \mathbb{N}_{\ge 2}\) which takes only finitely many distinct values, a connected finite dimensional algebra \(\Lambda\) is constructed, with the property that \({\rm {fin\; dim}}_{n} \Lambda = f(n)\) for all \(n\); here \({\rm {fin\; dim}}_{n} \Lambda\) is the \(n\)-generated finitistic dimension of \(\Lambda\). The stacking technique developed for this construction of homological examples permits strong control over the higher syzygies of \(\Lambda\)-modules in terms of the algebras serving as layers.
In situ formation of alkenyl- and alkynylboranes for Diels—Alder reactions by boron—silicon exchange with alkenyl- and alkynylsilanes

Abstract A variety of alkenylsilanes underwent transmetallation with BBr3 to afford the corresponding alkenyldibromoboranes in solution. Similarly, the transmetallation of alkynylsilanes with BCl3 afforded alkynyldichloroboranes. A number of the alkenyl- and alkynylboranes are novel and useful Diels—Alder dienophiles. An ionic mechanism for the transmetallation is proposed.
A unified perspective on robot control: the energy Lyapunov function approach

A unified framework for stability analysis for robot tracking control is presented. By using an energy-motivated Lyapunov function candidate, closed-loop stability is shown for a large family of control laws sharing a common structure of proportional and derivative feedback and model-based feedforward. The feedforward can be zero, partial or complete linearized dynamics, partial or complete nonlinear dynamics, or linearized or nonlinear dynamics with parameter adaptation. As a result, the dichotomous approaches to the robot control problem based on the open-loop linearization and nonlinear Lyapunov analysis are both included in this treatment. Furthermore, quantitative estimates of the trade-offs between different schemes in terms of the tracking performance, steady state error, domain of convergence, real-time computation load, and required a priori model information are derived. >
Towards self-predicting systems: What if you could ask ‘what-if’?

Today, management and tuning questions are approached using if… then… rules of thumb. This reactive approach requires expertise regarding system behavior, making it difficult to deal with unforeseen uses of a system’s resources and leading to system unpredictability and large system management overheads. We propose a What…if… approach that allows interactive exploration of the effects of system changes, thus converting complex tuning problem into simpler search problems. Through two concrete management problems, automating system upgrades and deciding on service migrations, we identify system design changes that enable a system to answer What…if… questions about itself.
The Political Economy of State-Provided Targeted Benefits

The governments of American states often attempt to incentivize businesses to locate within their borders by offering targeted benefits to particular industries and companies. These benefits come in many forms, including business tax credits for investments, property tax abatements, and reductions in the sales tax. Despite good intentions, policymakers often overlook the unseen and unintended negative consequences of targeted-benefit policies. This paper analyzes two major downsides of these policies: (1) they lead to a misallocation of resources, and (2) they encourage rent-seeking and thus cronyism. We argue that these costs, which are often longer-term and not readily observable at the time the targeted benefits are granted, may very well outweigh any possible short-term economic benefits.
Muon acceleration with a very fast ramping synchrotron for a neutrino factory

A 4600 Hz fast ramping synchrotron is explored as an economical way of accelerating muons from 4 to 20 GeV/c for a neutrino factory. Eddy current losses are minimized by the low machine duty cycle plus thin grain oriented silicon steel laminations and thin copper wires. Combined function magnets with high gradients alternating within single magnets form the lattice we describe. Muon survival is 83%.
Experimental investigation of turbulent flow through a circular-to-rectangular transition duct

Steady, incompressible, turbulent, swirl-free flow through a circular-to-rectangular transition duck was studied experimentally. The cross-sectional area remains the same at the exit as at the inlet, but varies through the transition section to a maximum value approximately 15 percent above the inlet value. The cross-sectional geometry everywhere along the duct is defined by the equation of a superellipse. Mean and turbulence data were accumulated utilizing pressure and hot-wire instrumentation at five stations along the test section. Data are presented for operating bulk Reynolds numbers of 88,000 and 390,000. Measured quantities include total and static pressure, the three components of the mean velocity vector, and the six components of the Reynolds stress tensor. In addition to the transition duct measurements, a hot-wire technique which relies on the sequential use of single rotatable normal and slant-wire probes was proposed. The technique is applicable for measurement of the total mean velocity vector and the complete Reynolds stress tensor when the primary flow is arbitrarily skewed relative to a plane which lies normal to the probe axis of rotation.
RR and R wave to finger pulse interval changes as a function of respiration rate and body position using VCRS

A technique of voluntary cardiorespiratory synchronization (VCRS), where the respiration rate is synchronized at a sub-multiple of the heart rate, was used to investigate the RR wave interval change and R to finger pulse interval change as a function of respiration in 6 subjects. Data were collected with subjects breathing at 4, 8, 12 beats per respiratory cycle in the supine and standing position. Following a tone, the subjects inspired for two, four or six heart beats and expired respectively for two, four, or six beats. The results showed a significant decrease in the RR interval with inspiration and an increase in the R to finger pulse time. This produces an approximate 180 degree phase difference between the pulse time interval change and the RR interval. It is unclear whether R-pulse interval change is due to blood pressure changes, other vasomotor factors or a change in the inotropic state of the heart.
QoS Routing in Smart Grid

Smart grid is an emerging technology which is able to control the power load via price signaling. The communication between the power supplier and power customers is a key issue in smart grid. Performance degradation like delay or outage may cause significant impact on the stability of the pricing based control and thus the reward of smart grid. Therefore, a QoS mechanism is proposed for the communication system in smart grid, which incorporates the derivation of QoS requirement and applies QoS routing in the communication network. For deriving the QoS requirement, the dynamics of power load and the load-price mapping are studied. The corresponding impacts of different QoS metrics like delay are analyzed. Then, the QoS is derived via an optimization problem that maximizes the total revenue. Based on the derived QoS requirement, a simple greedy QoS routing algorithm is proposed for the requirement of high speed routing in smart grid. It is also proven that the proposed greedy algorithm is a $K$-approximation. Numerical simulation shows that the proposed mechanism and algorithm can effectively derive and secure the communication QoS in smart grid.
DESIGN OPTIMIZATION OF ROCKET BASED COMBINED CYCLE INLET/EJECTOR SYSTEM

The goal of this current research was de termination and optimization of the Rocket Based Combined Cycle (RBCC) Engine inlet/ejector performance trend. For this purposes, a two dimensional rocket -ejector system was studied over a matrix of engine design variables. By pass ratio, ejector compressi on ratio and ejector/mixture thrust efficiency was used to analyze RBCC internal flow path physics. The primary thruster exit flow properties were calculated with the Reacting and Multiphase Program, which was used as fixed inlet conditions for the ejector /mixer analysis. The computational fluid dynamics (CFD) simulations of the inlet/ejector system were carried out with Finite Difference Navier Stokes (FDNS) code. The GO 2/GH 2 combustion physics were solved finite rate with a system of seven species and nin e reactions. The desirability approach of optimization, tied with response surface and neural networks technique has been used for response surface generation and inlet/ejector optimization. An optimum primary thruster size, duct length -to -diameter ratio and ramjet burner to ejector/mixer inlet area ratio are obtained. From this study, it is also noticed that using smaller primary rockets are more effective in reducing the mixing length.
Subsonic wing rock of slender delta wings

Two recent experimental studies investigated the s elf-excited motion Of a flat deita wing that was free to roll about an axis parallel to its mid-span chord. In this paper these experiments are s imulated numerically. An unsteady vortex-lattice method is used to provide the aerodynamic loads, and the equation of motion is integrated by a prediction-corre ction scheme. The solution provides complete histories of the motion of the wing and,the fl owfi eld simultaneously, fully accounting for dynamic-aerodyna mic interaction. The present simulation predicts that the symmetri c configuration of the 1 eadi ng-edge vortex system becomes unstable as the anyle of attack increases. Sequential views of the computed, time-dependent shape of the leading-edge system Show how this causes a loss of roll damping at small a nyles of roll. Consequently, at sufficiently high incidence, s mall disturbances i ntroduced into the flowfield grow, causing wing rock to develop. For anyles of attack at onset and amplitudes and periods of the ensuing limit cycles, the numerical predictions and the experimental o bservations are in agreement. The simulation shows the influence of the experimental parameters and provides an explanation for the differences in the observations
Additions of electrophilic radicals to electron rich alkenes by the atom transfer method. Surmounting potentially reversible radical atom transfer reactions by irreversible ionic reactions

Abstract Conditions have been developed for the atom transfer radical addition reaction of bromoesters to enol ethers. The putative intermediate haloethers are allowed to ionize and the resulting cations are trapped by addition or elimination reactions.
Preparation of 4,5 disubstituted-2H-1,2,3-triazoles from (Z)-2,3-diaryl substituted acrylonitriles

2H-1,2,3-Triazoles (2) were synthesized by [3+2] cycloaddition of (Z)-2,3-diaryl substituted acrylonitriles (1) with sodium azide and ammonium chloride in DMF/water. This method represents a facile and efficient reaction procedure for the synthesis of 4,5-diaryl-2H-1,2,3-triazoles in modest to good yields.
A Convenient Two-Step Procedure for Lactone α-Methylenation

Abstract A new procedure for lactone α-methylenation is described in which α-hydroxymethyl lactones are dehydrated with cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulfonate-CuCl2 in acetonitrile.
Palladium‐Catalyzed Asymmetric Construction of Vicinal All‐Carbon Quaternary Stereocenters and its Application to the Synthesis of Cyclotryptamine Alkaloids

We report the use of a two-fold Pd-catalyzed decarboxylative allylic alkylation (Pd-DAAA) to construct two vicinal all carbon quaternary stereocenters in a diastereo- and enantioselective fashion. To demonstrate the synthetic utility of this process, the products of the Pd-DAAA were elaborated to complete the formal syntheses of the cyclotryptamine alkaloids. Mechanistic investigations have revealed that the two-fold Pd-catalyzed transformation proceeds through an initial matched first allylation followed by a second mismatched allylation to deliver the desired product.
Vertically Aligned Carbon Nanotubes as the Sputter Resist in Space Propulsive Systems

Two-types of vertically aligned multi-walled carbon nanotubes (VA-MWNTs) are evaluated as the protective coatings against ion erosion in electric propulsion systems. A series of experiments have been conducted to understand the erosion rate and erosion mechanism of these VA-MWNTs. These experiments were carried out with Xe propellant at an ion current density of 5 mA/cm 2 . We found that the erosion rates of both types of VA-MWNTs were changing with time. Such a nonlinear erosion process is explained according to a possible erosion mechanism.
Political risk and capital flight

Capital flight often amounts to a substantial proportion of GDP in developing countries. This paper presents a portfolio choice model that relates capital flight to return differentials, risk aversion, and three types of risk: economic risk, political instability, and policy variability. Estimating the equilibrium capital flight equation for a panel of 45 developing countries over 16 years, all three types of risk have a statistically significant impact on capital flight. Quantitatively, political instability is the most important factor associated with capital flight. We also identify several political factors that reduce capital flight, ostensibly by signaling that market-oriented reforms are imminent. 2005 Elsevier Ltd. All rights reserved.
Zinc Carbenoid-Mediated Chain Extension: Preparation of α,β-Unsaturated-γ-keto Esters and Amides

An efficient one-pot preparation of alpha,beta-unsaturated-gamma-keto esters and amides has been developed. A zinc carbenoid-mediated chain extension of a beta-dicarbonyl substrate provides access to an intermediate zinc enolate, which is treated sequentially with a halogen and amine base. This method has been applied to a variety of ester and amide starting materials, as well as to amino acid-derived substrates and to a formal synthesis of (R,R)-(-)-pyrenophorin.
Condenser optics, partial coherence, and imaging for soft-x-ray projection lithography

A condenser system couples the radiation source to an imaging system, controlling the uniformity and partial coherence at the object, which ultimately affects the characteristics of the aerial image. A soft-x-ray projection lithography system based on a ring-field imaging system and a laser-produced plasma x-ray source places considerable constraints on the design of a condenser system. Two designs are proposed, critical illumination and Kohler illumination, each of which requires three mirrors and scanning for covering the entire ring field with the required uniformity and partial coherence. Images based on Hopkins' formulation of partially coherent imaging are simulated.
Do Firms Underinvest in Long-Term Research? Evidence from Cancer Clinical Trials

We investigate whether private research investments are distorted away from long-term projects. Our theoretical model highlights two potential sources of this distortion: short-termism and the fixed patent term. Our empirical context is cancer research, where clinical trials—and hence, project durations—are shorter for late-stage cancer treatments relative to early-stage treatments or cancer prevention. Using newly constructed data, we document several sources of evidence that together show private research investments are distorted away from long-term projects. The value of life-years at stake appears large. We analyze three potential policy responses: surrogate (non-mortality) clinical-trial endpoints, targeted R&D subsidies, and patent design. (JEL D92, G31, I11, L65, O31, O34)
Consumer direct fulfillment performance in Internet retailing : emergency transshipments and demand dispersion

The collaborative fulfillment of consumer orders by Internet retailers and wholesalers has proven important in the realization of sustainable levels of online profitability. Concentrating on consumer direct fulfillment (or drop shipping), an empirical simulation model evaluates avenues for improving logistical performance. The empirical simulation model centers on the online music CD retailing industry. It evaluates the effects of emergency transshipments and demand dispersion on inventory and product-release performance, as well as on transportation costs, in consumer direct fulfillment operations. Results show that emergency transshipments improve inventory and product-release performance in these operations. Furthermore, the inventory-performance improvements are maximized when inventory facilities fulfill demand that is uniformly balanced across markets primarily assigned to each facility. Finally, gains in inventory and release performance obtained from emergency transshipments outweigh additional transportation costs incurred from a greater reliance on emergency transshipments for consumer direct fulfillment.
Retail Store Density and the Cost of Greenhouse Gas Emissions

The density, size, and location of stores in a retailer's network influences both the retailer's and the consumers' costs. With stores few and far between, consumers must travel a long distance to shop, whereas shopping trips are shorter with a dense network of stores. The layout of the retail supply chain is of interest to retailers who have emission reduction targets and urban planners concerned with sprawl. Are small local shops preferred over large, “big-box” retailers? A model of the retail supply chain is presented that includes operating costs such as fuel and rent for floor space as well as a cost for environmental externalities associated with carbon emissions. A focus on exclusively minimizing operating costs may substantially increase emissions by 67% in one scenario relative to the minimum level of emissions. A price on carbon is an ineffective mechanism for reducing emissions. The most attractive option is to improve consumer fuel efficiency---doubling the fuel efficiency of cars reduces long-run emissions by about one-third, whereas an improvement in truck fuel efficiency has a marginal impact on total emissions. This paper was accepted by Yossi Aviv, operations management.
Firm dynamics, markup variations, and the business cycle

We present a model in which net business formation is endogenously procyclical. Variations in the number of operating firms lead to countercyclical variations in markups that give rise to endogenous procyclical movements in measured total factor productivity (TFP). Based on this result, the paper suggests a simple structural decomposition of variations in TFP into those originating from exogenous shocks and those originating endogenously from the interaction between firms’ entry and exit decisions and the degree of competition. The decomposition suggests that around 40% of the movements in measured TFP can be attributed to this interaction. Moreover, the paper analyzes the effects on (i) the measurement of the volatility of exogenous shocks in the U.S. economy and (ii) the magnification of shocks over the business cycle.
The preparation of semiconductor devices by lapping and diffusion techniques

A new approach to the fabrication of semiconductor devices has been investigated. This approach allows the processing of large semiconductor wafers to a point where they can be diced into numerous and identical devices. Lapping, instead of etching, is employed for all shaping of the units and the high degree of precision built into the lapping apparatus is passed on to all of the devices prepared. The approach is applicable to the fabrication of a great variety of semiconductor devices. Unipolar photounipolar as well as bipolar transistors and negative resistance devices have been fabricated. These devices exhibit superior electrical characteristics. Silicon power transistors have current transfer ratios in the 20-40 range and power gains from 30-40 db. Silicon unipolar transistors have transconductances in the neighborhood of 500 µmhos and input resistances of about 100 megohms, Silicon photounipolar transistors show a dc photo response of 2-20 amperes per lumen.
Beyond the desktop: emerging technologies for supporting 3D collaborative teams

The emergence of several trends, including the increased availability of wireless networks, miniaturization of electronics and sensing technologies, and novel input and output devices, is creating a demand for integrated, fulltime displays for use across a wide range of applications, including collaborative environments. In this paper, we present and discuss emerging visualization methods we are developing particularly as they relate to deployable displays and displays worn on the body to support mobile users.
Limits on achievable intensity reduction with an optical occulter.

Deep shadowing of a normally incident plane wave by an opaque circular disk is partially negated by the formation of a region of strong intensity surrounding the axis passing normally through the disk center. This local intensity enhancement, historically referred to as the Poisson Spot (also known as the Spot of Arago), has been the principal source of difficulties in applications where a significant reduction of the incident intensity is essential. In particular, the NASA Terrestrial Planet Finder’s (TPF) mission requires suppression of direct starlight by at least 10 orders of magnitude over the entire visible spectral range. One technique that has been proposed for blocking the direct starlight is to use a rotationally symmetric disk with petallike segments along its boundary. We find that, even though such configurations could, indeed, theoretically provide the desired intensity reduction, they would require unreasonably small radii of curvature at the petals’ tips (in the range of micrometers). When the radii of curvature are increased to 3 mm, the intensity reduction drops to a modest 5 to 6 orders of magnitude. Given that for the NASA’s TPF mission the proposed occulter radius would be on the order of 25 m, even the 3 mm radius of curvature would be too small for any practical implementation. Further increases of the radius of curvature result in progressively poorer intensity suppression. As an alternative solution we propose an apodized circular disk. We show that with an optimized apodization function, intensity reductions of at least 10 orders of magnitude can be achieved over the entire visible spectral range. Numerical results are presented for parameters appropriate to the NASA TPF mission.
Critical behavior in lossy source coding

The following critical phenomenon was recently discovered. When a memoryless source is compressed using a variable-length fixed-distortion code, the fastest convergence rate of the (pointwise) compression ratio to R(D) is either O(/spl radic/n) or O(log n). We show it is always O(/spl radic/n), except for discrete, uniformly distributed sources.
The kinder, gentler gaze of Big Brother Reality TV in the era of digital capitalism

Surveillance-based reality television has emerged as a resurgent programming genre in the US and Western Europe during a time when the online economy is becoming increasingly reliant upon surveillance as a form of economic exploitation. The portrayal of surveillance through 'reality TV' as a form of entertainment and self-expression can thus be understood as playing an important role in training viewers and consumers for their role in an 'interactive' economy. This article relies on interviews with cast members and producers of MTV's popular reality show 'Road Rules', to explore the form of subjectivity that corresponds to its implicit definition of 'reality'. This form of subjectivity reinforces the promise of the interactive economy to democratize production by relinquishing control to consumers and viewers. Surveillance is portrayed not as a form of social control, but as the democratization of celebrity - a fact that has disturbing implications for the democratic potential of the internet's interactive capability.
Computer-aided optimization of DC/DC converters for automotive applications

This paper investigates computer-aided optimization of DC/DC converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization approach based on Monte Carlo search methods is introduced which allows the design space to be rapidly explored in an automated fashion and the most optimal designs and design approaches to be identified. The optimization approach also allows the effects of variations in design specifications on the cost, weight, and volume of an optimized converter to be readily determined. A prototype converter designed using this optimization procedure is evaluated and compared to a converter designed by conventional means.
Estimation, Learning and Parameters of Interest in a Multiple Outcome Selection Model

We describe estimation, learning, and prediction in a treatment-response model with two outcomes. The introduction of potential outcomes in this model introduces four cross-regime correlation parameters that are not contained in the likelihood for the observed data and thus are not identified. Despite this inescapable identification problem, we build upon the results of Koop and Poirier (1997) to describe how learning takes place about the four nonidentified correlations through the imposed positive definiteness of the covariance matrix. We then derive bivariate distributions associated with commonly estimated “treatment parameters” (including the Average Treatment Effect and effect of Treatment on the Treated), and use the learning that takes place about the nonidentified correlations to calculate these densities. We illustrate our points in several generated data experiments and apply our methods to estimate the joint impact of child labor on achievement scores in language and mathematics.
Results on Finite Wireless Networks on a Line

Analysis of finite wireless networks is a fundamental problem in the area of wireless networking. Today, due to the vast amount of literature on large-scale wireless networks, we have a fair understanding of the asymptotic behavior of such networks. However, in real world we have to face finite networks for which the asymptotic results cease to be valid. We refer to networks as being finite when the number of nodes is less than a few hundred. Here we study a model of wireless networks, represented by random geometric graphs. In order to address a wide class of the network's properties, we study the threshold phenomena. Being extensively studied in the asymptotic case, the threshold phenomena occurs when a graph theoretic property (such as connectivity) of the network experiences rapid changes over a specific interval of the underlying parameter. Here, we find an upper bound for the threshold width of finite line networks represented by random geometric graphs. These bounds hold for all monotone properties of such networks. We then turn our attention to an important non-monotone characteristic of line networks which is the Medium Access (MAC) layer capacity, i.e. the maximum number of possible concurrent transmissions. Towards this goal, we provide a linear time algorithm which finds a maximal set of concurrent non-interfering transmissions and further derive lower and upper bounds for the cardinality of the set. Using simulations, we show that these bounds serve as reasonable estimates for the actual value of the MAC-layer capacity.
Managing Know-How

We study how firms can use a knowledge management system to optimally leverage employee-generated know-how. In particular, we consider the following practical strategic questions for the manager of a knowledge-intensive firm: Should her firm develop a formal knowledge system? And if so, how should it be managed, particularly in terms of what information to record? We find that firms benefit more from a knowledge system when they are larger, face the same issues more frequently, have higher turnover, and face problems about which there is less general knowledge. In terms of what information to record, a key insight is that recording moderately successful practices can be counterproductive, because doing so may inefficiently reduce employees' incentives to experiment. This “strong-form competency trap” forces firms into an exploration--exploitation trade-off. Firms that value a knowledge system most should also be most selective in recording information. We further find that recording successes is more valuable than recording failures, which supports firms' focus on best practice. Beyond these main principles, we also show that it may be optimal to disseminate know-how on a plant level but not on a firm level, and that recording backup solutions is most valuable at medium levels of environmental change.
Complex reactions in oscillating reactors

Previous work has shown that perturbation methods are useful for estimating the difference between the time average conversion obtained from an oscillating reactor and the optimum steady state value. The present study extends this approach to complex kinetic mechanisms. Both forced and self-generated oscillations are studied, and in the latter case both positive and negative feedback control systems are used to alter the shape of the oscillations. The results indicate that large improvements in yields sometimes can be observed for parallel reactions but that only small improvements are possible for consecutive reactions, in the range of system parameters considered.
Inflation, corruption, and income distribution: The recent price reform in China

Abstract This paper determines the effects of price deregulation and analyzes the theoretical relationship between price increases, corruption, and income distribution. Price deregulation does not necessarily cause a jump in the general price level, but partial price deregulation can be a root of corruption. Widespread corruption generally leads to further price increases and creates severe income distribution problems. Because of its recent economic reform and experiences, China was chosen as a case study, while the analysis can be extended to other countries.
Top-down Proteomics Reveals Concerted Reductions in Myofilament and Z-disc Protein Phosphorylation after Acute Myocardial Infarction

Heart failure (HF) is a leading cause of morbidity and mortality worldwide and is most often precipitated by myocardial infarction. However, the molecular changes driving cardiac dysfunction immediately after myocardial infarction remain poorly understood. Myofilament proteins, responsible for cardiac contraction and relaxation, play critical roles in signal reception and transduction in HF. Post-translational modifications of myofilament proteins afford a mechanism for the beat-to-beat regulation of cardiac function. Thus it is of paramount importance to gain a comprehensive understanding of post-translational modifications of myofilament proteins involved in regulating early molecular events in the post-infarcted myocardium. We have developed a novel liquid chromatography–mass spectrometry-based top-down proteomics strategy to comprehensively assess the modifications of key cardiac proteins in the myofilament subproteome extracted from a minimal amount of myocardial tissue with high reproducibility and throughput. The entire procedure, including tissue homogenization, myofilament extraction, and on-line LC/MS, takes less than three hours. Notably, enabled by this novel top-down proteomics technology, we discovered a concerted significant reduction in the phosphorylation of three crucial cardiac proteins in acutely infarcted swine myocardium: cardiac troponin I and myosin regulatory light chain of the myofilaments and, unexpectedly, enigma homolog isoform 2 (ENH2) of the Z-disc. Furthermore, top-down MS allowed us to comprehensively sequence these proteins and pinpoint their phosphorylation sites. For the first time, we have characterized the sequence of ENH2 and identified it as a phosphoprotein. ENH2 is localized at the Z-disc, which has been increasingly recognized for its role as a nodal point in cardiac signaling. Thus our proteomics discovery opens up new avenues for the investigation of concerted signaling between myofilament and Z-disc in the early molecular events that contribute to cardiac dysfunction and progression to HF.
Combining high conductivity with complete optical transparency: A band structure approach

A comparison of the structural, optical and electronic properties of the recently discovered transparent conducting oxide (TCO), nanoporous Ca12Al14O33, with those of the conventional TCOs (such as Sc-doped CdO) indicates that this material belongs conceptually to a new class of transparent conductors. For this class of materials, we formulate criteria for the successful combination of high electrical conductivity with complete transparency in the visible range and emphasize the significant correlation between their structural characteristics and electronic and optical properties. Our analysis suggests that this set of requirements can be met for a group of novel materials called electrides which may have desired features such as connected structural cavities, large bandgaps and near-metallic electronic conductivity.
Enantioselective Acylation of Silyl Ketene Acetals through Fluoride Anion-Binding Catalysis

A highly enantioselective acylation of silyl ketene acetals with acyl fluorides has been developed to generate useful α,α-disubstituted butyrolactone products. This transformation is promoted by a new thiourea catalyst and 4-pyrrolidinopyridine and represents the first example of enantioselective thiourea anion-binding catalysis with fluoride.
The sensitivity of global climate to the episodicity of fire aerosol emissions

Abstract. One of the major ways in which forest and grass fires have an impact on global climate is through the release of aerosols. Most studies focusing on calculating the radiative forcing and other climate impacts of fire aerosols use monthly mean emissions derived from the Global Fire Emissions Database that captures only the seasonal cycle of fire aerosol emissions. Here we present the results of a sensitivity study that investigates the climate response to the episodicity of the fires, based on the standard approach which releases emissions every day, and contrasts that to the response when fires are represented as intense pulses of emissions that occur only over 1–2 days on a monthly, yearly, or five-yearly basis. Overall we find that in the modified cases with increased levels of episodicity, the all sky direct effect radiative forcing increases, the clear sky direct effect radiative forcing remains relatively constant, and the magnitude of the indirect effect radiative forcing decreases by about 1 W m−2 (from −1.6 to −0.6 W m−2). In the long term, we find that an increase in aerosol emission episodicity leads to an asymmetric change in indirect radiative forcing in the Northern Hemisphere compared to the Southern Hemisphere contributes to a slight shift in the annual average position of the intertropical convergence zone (ITCZ). This shift is found to have a mixed effect on the overall performance of the model at predicting precipitation rates in the tropics. Given these results we conclude that future studies that look to assess the present day global climate impacts of fire aerosols should consider the need to accurately represent fire episodicity.
Locations of Satellite Galaxies in the Two-Degree Field Galaxy Redshift Survey

We compute the locations of satellite galaxies in the Two-Degree Field Galaxy Redshift Survey using two sets of selection criteria and three sources of photometric data. Using the SuperCOSMOS 𝑟𝐹 photometry, we find that the satellites are located preferentially near the major axes of their hosts, and the anisotropy is detected at a highly significant level (confidence levels of 99.6% to 99.9%). The locations of satellites that have high velocities relative to their hosts are statistically indistinguishable from the locations of satellites that have low velocities relative to their hosts. Additionally, satellites with passive star formation are distributed anisotropically about their hosts (99% confidence level), while the locations of star-forming satellites are consistent with an isotropic distribution. These two distributions are, however, statistically indistinguishable. Therefore it is not correct to interpret this as evidence that the locations of the star-forming satellites are intrinsically different from those of the passive satellites.
Diisopropyl tartrate (E)-γ-(dimethylphenylsilyl)allylboronate, a chiral allylic alcohol β-carbanion equivalent for the enantioselective synthesis of 2-butene-1,4-diols from aldehydes

Abstract An enantioselective synthesis of 4-substituted (E)-2-buten-1,4-diols is described. The method involves the reaction of aldehydes with the chiral PhMe2Si- substituted allylboronate3 followed by epoxidation (dimethyl dioxirane) and acid catalyzed Petersen rearrangement of the intermediate epoxysilanols.
Air bearing design considerations for constant fly height applications

Various air bearing designs are compared for a typical 3.5-inch disk drive application. The air bearing designs discussed here are machined taper flat (MTF), shaped rail positive pressure, negative pressure, and transverse pressure contour (TPC). The comparisons are based on the results of computer simulations. The strengths and weaknesses of these designs with respect to some of the important design considerations are discussed. The MTF designs are not capable of constant fly height. The shaped rail positive pressure designs, both two-rail and tri-rail, have significantly flatter fly height profiles, tighter fly height tolerances and better performance as compared to the MTF designs. The TPC designs give near constant by height under a wide range of conditions but are very sensitive to manufacturing tolerances and require tighter process controls than other designs do. They also have large skew sensitivity which results in accessing fly height loss no better than that for shaped rail designs. The negative pressure designs have the best overall performance. They permit low gram load for improved head/disk interface reliability and also work well at high gram loads. The negative pressure designs have tighter fly height tolerances, lower crown sensitivity, lower skew sensitivity, and better accessing performance as compared to the other designs discussed here. >
Astrophysical measurement of the equation of state of neutron star matter

We present the first astrophysical measurement of the pressure of cold matter above nuclear saturation density, based on recently determined masses and radii of three neutron stars. The pressure at higher densities is below the predictions of equations of state that account only for nucleonic degrees of freedom, and thus present a challenge to the microscopic theory of neutron star matter.
A Review of Anode Phenomena in Vacuum Arcs

This paper discusses are modes at the anode, experimental results pertinent to anode phenomena, and theoretical explanations of anode phenomena. A vacuum are can exhibit five anode discharge modes: (1) a low current mode in which the anode is basically passive, acting only as a collector of particles emitted from the cathode; (2) a second low current mode that can occur if the electrode material is readily sputtered (a flux of sputtered atoms will be emitted by the anode); (3) a footpoint mode, characterized by the appearance of one or more small luminous spots on the anode (footpoints are generally much cooler than the true anode spots present in the last two modes); (4) an anode spot mode in which one large or several small anode spots are present (such spots are very luminous, have a temperature near the atmospheric boiling point of the anode material, and are a copious source of vapor and ions); and (5) an intense are mode where an anode spot is present, but accompanied by severe cathode erosion. The are voltage is relatively low and quiet in the two low current modes and the intense are mode. It is usually high and noisy in the footpoint mode, and it can be either in the anode spot mode. Anode erosion is low, indeed negative, in the two low current modes, and it is low to moderate in the footpoint mode. Severe anode erosion occurs in both the anode spot and intense are modes. The dominant mechanism controlling the formation of an anode spot appears to depend upon the electrode geometry, the electrode material, and the current waveform of the particular vacuum are being considered. In specific experimental conditions, either magnetic constriction in the gap plasma, or gross anode melting, or local anode evaporation can trigger the transition. However, the most probable explanation of anode spot formation is a combination theory, which considers magnetic constriction in the plasma together with the fluxes of material from the anode and cathode as well as the thermal, electrical, and geometric effects of the anode in analyzing the behavior of the anode and the nearby plasma.