cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigation of oxidative coupling of methane over bismuth oxychloride, samarium chloride, or manganese chloride supported on lithium carbonate-magnesia systems

Abstract The magnesia-supported bismuth oxychloride with lithium carbonate present is significantly more effective and stable with time-on-stream than the unsupported or supported systems free of Li 2 CO 3 in the oxidative coupling of methane at 750°C, P CH4 = 20.2 kPa, CH 4 /O 2 = 4, and aspace velocity of 15,000 cm 3 g −1 h −1 . The most effective catalytic system is obtained when 10 mol% BiOCl is supported on MgO with 10 mol% Li 2 CO 3 , which leads to a methane conversion of 18%, C 2 selectivity of 83%, and an ethylene-to-ethane molar ratio of 2.9 for at least 12 h under the aforementioned conditions and atmospheric pressure. The unsupported or supported samarium chloride free of Li 2 ,CO 3 was less effective under similar conditions. Only when the samarium chloride and lithium carbonate contents on the support were sufficiently increased (28 and 40 mol%, respectively) the system became effective towards high C 2 selectivity and stability. In contrast, none of the manganese-chloride-based systems exhibited good C 2 selectivity and stability except initially, but they mainly promoted the reaction of methane to carbon oxides. The presence of chlorine, the nature of the cation associated with it and lithium are found to be key factors in determining the performance of the catalysts. The introduction of Li 2 CO 3 is found to retard the loss of surface chlorine and prevent the decrease of surface bismuth and samarium, resulting thereby in more stabilized systems. In addition, the bulk and surface modifications, which are more prominent in the presence of Li 2 CO 3 , caused by calcination and reaction conditions are believed to influence the formation of the catalytically active or inactive sites. The performance of the catalysts is related to its surface composition, bulk modification, decomposition, and reducibility of the metal chlorides or oxychloride on the basis of XPS, XRD, SEM, and thermal analysis (TPD and TPR) investigations.
Operating the hubble space telescope

The Hubble Space Telescope and its capabilities are described, and techniques of operating the observatory are discussed. The operational ground system functions are described. Some projections of what might be learned with this new instrument are presented.
Synthesis of dinucleoside phosphorodithioates via thioamidites

Abstract Deoxynucleosides and S-(4-chlorobenzyl)-phosphorothiodiamidites react via phosphorothioamidites to form thiophosphite triesters. Sulfur oxidation yields dinucleoside phosphorodithioate triesters which can be used to selectively introduce dithioate linkages into DNA.
Loyalty, peer group effects, and 401(k)

Abstract In this paper we analyze investors’ behavior in the presence of social interactions. Two main models are explored: one based on peer group effects and the other on loyalty. The motivation for this study is the observed behavior of employees when choosing asset allocation for their 401(k) funds. Employees are typically overinvested in own company stock, while theory predicts a strong diversification motive. We argue that the proposed models justify this behavior, even in an environment with full rationality. We also contrast the implications of each model concerning other risky assets.
Bureaucratic Discretion, Agency Structure, and Democratic Responsiveness: The Case of the United States Attorneys

Structural choices have fundamental and continuing effects on the democratic responsiveness of public agencies. In contrast to popular accounts of the United States Attorneys' splendid isolation,
Estimation of alternative splicing isoform frequencies from RNA-Seq data

Massively parallel whole transcriptome sequencing, commonly referred as RNA-Seq, is quickly becoming the technology of choice for gene expression profiling. However, due to the short read length delivered by current sequencing technologies, estimation of expression levels for alternative splicing gene isoforms remains challenging. In this paper we present a novel expectation-maximization algorithm for inference of isoform- and gene-specific expression levels from RNA-Seq data. Our algorithm, referred to as IsoEM, is based on disambiguating information provided by the distribution of insert sizes generated during sequencing library preparation, and takes advantage of base quality scores, strand and read pairing information when available. The open source Java implementation of IsoEM is freely available at http://dna.engr.uconn.edu/software/IsoEM/ . Empirical experiments on both synthetic and real RNA-Seq datasets show that IsoEM has scalable running time and outperforms existing methods of isoform and gene expression level estimation. Simulation experiments confirm previous findings that, for a fixed sequencing cost, using reads longer than 25-36 bases does not necessarily lead to better accuracy for estimating expression levels of annotated isoforms and genes.
From Minimax Shrinkage Estimation to Minimax Shrinkage Prediction

In a remarkable series of papers beginning in 1956, Charles Stein set the stage for the future development of minimax shrinkage estimators of a multivariate normal mean under quadratic loss. More recently, parallel developments have seen the emergence of minimax shrinkage estimators of multivariate normal predictive densities under Kullback–Leibler risk. We here describe these parallels emphasizing the focus on Bayes procedures and the derivation of the superharmonic conditions for minimaxity as well as further developments of new minimax shrinkage predictive density estimators including multiple shrinkage estimators, empirical Bayes estimators, normal linear model regression estimators and nonparametric regression estimators.
Multiple slip in copper single crystals deformed in compression under uniaxial stress

Uniaxial compression experiments on copper single crystals, oriented to maximize the shear for one slip system, show activity on the primary slip system as well as appreciable activity orthogonal to the primary system. Utilizing three-dimensional digital image correlation, the amount of orthogonal slip has been quantified. The activity orthogonal to the primary occurs from the onset of deformation and varies from being equal to the primary for the as-fabricated samples to 1/5 of the primary in the samples annealed after fabrication.
Metadata of Art and Architecture Research Databases: The Value of Abstracts and Index Terms to Academics, Librarians, and Museum Professionals

ABSTRACT Against a backdrop of increasing access to full text and the perceived success of Web search engines, academic disciplines with highly specialized, if not esoteric, nomenclature remain in need of specially crafted metadata. Art history and the study of architecture represent two such disciplines. Historically, field-specific research databases have maintained canons of citations complemented with descriptive abstracting and precise indexing. Surveys of art and architectural historians identify the value of abstracting and indexing to scholarly research. The perceived importance indicates a need to integrate discipline-specific abstracts and vocabularies into the evolving Web-based infrastructure for searching of scholarly literature and to enable the continued production of such metadata.
Doubling down on naturalness with a supersymmetric twin Higgs

We show that naturalness of the weak scale can be comfortably reconciled with both LHC null results and observed Higgs properties provided the double protection of supersymmetry and the twin Higgs mechanism. This double protection radically alters conventional signs of naturalness at the LHC while respecting gauge coupling unification and precision electroweak limits. We find the measured Higgs mass, couplings, and percent-level naturalness of the weak scale are compatible with stops at ~ 3.5 TeV and higgsinos at ~ 1 TeV. The primary signs of naturalness in this scenario include modifications of Higgs couplings, a modest invisible Higgs width, resonant Higgs pair production, and an invisibly-decaying heavy Higgs.
Ring expansive routes to quinolizidine alkaloids: formal synthesis of (-)-lasubine II.

The application of two nitrogen ring expansion reactions to lasubine alkaloid synthesis is reported. The approach involves a conjugate reduction/alkylation sequence carried out on triisopropylsilyl-protected (S)-4-(−)-hydroxycyclopentenone, the formation of the quinolizidone ring system through nitrogen ring expansion, and the addition of an arylmetallic species to the resulting lactam. This work resulted in the preparation of 2-epi-lasubine II and a formal synthesis of lasubine II.
Improving Energy Codes

Energy codes set efficiency standards for buildings in the majority of U.S. states. Under most energy codes, builders can comply by demonstrating that the projected private expenditures on energy bills for a proposed building are less than a certain threshold. Using theory and evidence, I show that energy codes would be improved if compliance was instead determined by the projected social damages. Relative to current practice, damage-based codes would likely provide stronger incentives for electricity than natural gas conservation, in most states. Implementation of damage-based codes would lead to substantial welfare gains.
Production, Outflow Velocity, and Radial Distribution of H2O and OH in the Coma of Comet C/1995 O1 (Hale-Bopp) from Wide-Field Imaging of OH

Observations of OH are a useful proxy of the water production rate (Q(sub H2O)) and outflow velocity (V(sub out)) in comets. We use wide field images taken on 03/28/1997 and 04/08/1997 that capture the entire scale length of the OH coma of comet C/1995O1 (Hale-Bopp) to obtain Q(sub H2O) from the model-independent method of aperture summation. We also extract the radial brightness profile of OH 3080 angstroms out to cometocentric distances of up to 10(exp 6) km using an adaptive ring summation algorithm. Radial profiles are obtained as azimuthal averages and in quadrants covering different position angles relative to the comet-Sun line. These profiles are fit using both fixed and variable velocity two-component spherical expansion models to determine VOH with increasing distance from the nucleus. The OH coma of Hale-Bopp was more spatially extended than in previous comets, and this extension is best matched by a variable acceleration of H2O and OH that acted across the entire coma, but was strongest within 1-2 x 10(exp 4) km from the nucleus. This acceleration led to VOH at 10(exp 6) km that was 2-3 times greater than that obtained from a 1P/Halleytype comet at 1 AU, a result that is consistent with gas-kinetic models, extrapolation from previous observations of OH in comets with Q(sub H2O) > 10(exp 29)/s, and radio measurements of the outer coma Hale-Bopp OH velocity profile. When the coma is broken down by quadrant, we find an azimuthal asymmetry in the radial distribution that is characterized by an increase in the spatial extent of OH in the region between the orbit-trailing and anti-sunward directions. Model fits to this area and comparison with radio OH measurements suggest greater acceleration in this region, with VOH UP to 1.5 times greater at 10(exp 6) km radial distance than elsewhere in the coma.
MRI in unexplained mononeuropathy

Four young patients with severe unexplained progressive mononeuropathy are described. None had a history of known trauma to the affected limb. In addition to the standard neurologic examination and electrophysiologic studies (nerve conduction studies and electromyography), all underwent neuroimaging of the involved extremity. In three patients, magnetic resonance imaging revealed intrinsic abnormalities of the appropriate nerve. The pattern or absence of magnetic resonance imaging changes directly influenced decisions about surgical exploration of the nerve in all four patients. With the advent of more sophisticated technology, magnetic resonance neurography has become a potent diagnostic tool in the evaluation of disorders of peripheral nerve and muscle.
Buyer-Option Contracts Restored: Renegotiation, Inefficient Threats, and the Hold-Up Problem

"Buyer-option" contracts, in which the buyer selects the product variant to be traded and chooses whether to accept delivery, are often used to solve holdup problems. We present a simple game that focuses sharply on subgames in which the buyer proposes inefficient actions in order to improve his bargaining position. We argue for one of several alternative ways to model this situation. We then apply that modeling choice to recent models of the foundations of incomplete contracts and show that a buyer-option contract is sufficient to induce first-best outcomes. Copyright 2004, Oxford University Press.
Regional Travel-Time Uncertainty and Seismic Location Improvement Using a Three-Dimensional a priori Velocity Model

We demonstrate our ability to improve regional travel-time prediction and seismic event location accuracy using an a priori 3D velocity model of Western Eurasia and North Africa (WENA1.0). Travel-time residuals are assessed relative to the iasp91 model for approximately 6000 Pg, Pn , and P arrivals, from seismic events having 2 σ epicenter accuracy between 1 km and 25 km (ground truth 1 [GT1] and GT25, respectively), recorded at 39 stations throughout the model region. Ray paths range in length between 0° and 40° (local, regional, and near teleseismic) providing depth sounding that spans the crust and upper mantle. The dataset also provides representative geographic sampling across Eurasia and North Africa including aseismic areas. The WENA1.0 model markedly improves travel-time predictions for most stations with an average variance reduction of 29% for all ray paths from the GT25 events; when we consider GT5 and better events alone, the variance reduction is 49%. For location tests we use 196 geographically distributed GT5 and better events. In 134 cases (68% of the events), locations are improved, and average mislocation is reduced from 24.9 km to 17.7 km. We develop a travel-time uncertainty model that is used to calculate location coverage ellipses. The coverage ellipses for WENA1.0 are validated to be representative of epicenter error and are smaller than those for iasp91 by 37%. We conclude that a priori models are directly applicable where data coverage limits tomographic and empirical approaches, and the development of the uncertainty model enables merging of a priori and data-driven approaches using Bayesian techniques. Online material: Correction surfaces and histograms of travel-time residuals for 40 stations.
Chandra Observations of the A3266 Galaxy Cluster Merger

Analysis of a 30,000 s X-ray observation of the A3266 galaxy cluster with the ACIS on board the Chandra X-Ray Observatory has produced several new insights into the cluster merger. The intracluster medium has a nonmonotonically decreasing radial abundance profile. We argue that the most plausible origin for the abundance enhancement is unmixed, high-abundance subcluster gas from the merger. The enrichment consists of two stages: off-center deposition of a higher abundance material during a subcluster merger followed by a strong, localized intracluster wind that acts to drive out the light elements, producing the observed abundance enhancement. The wind is needed to account for both an increase in the heavy-element abundance and the lack of an enhancement in the gas density. Dynamical evidence for the wind includes (1) a large-scale, low surface brightness feature perpendicular to the merger axis that appears to be an asymmetric pattern of gas flow to the northwest, away from the center of the main cluster; (2) compressed gas in the opposite direction (toward the cluster center); and (3) the fact that the hottest regions visible in the temperature map coincide with the proposed merger geometry and the resultant gas flow. The Chandra data for the central region of the main cluster show a slightly cooler, filamentary region that is centered on the central cD galaxy and is aligned with the merger axis directly linking the dynamical state of the cD to the merger. Overall, the high spectral/spatial resolution Chandra observations support our earlier hypothesis that we are viewing a minor merger in the plane of the sky.
Design, development, and assessment of mobile applications: the case for problem-based learning

This paper describes efforts to develop a pedagogical environment that seeks to influence the learning experiences of students as mobile applications end users, developers, and decision makers. Specifically, via a collaborative effort involving industry sponsors, university technology services, and multiple academic units engaged in information technology education, a graduate-level course called Mobile Applications Development (MAD) was created. The core innovativeness of MAD lies in its delivery structure as a problem-based learning course-centered on emerging technologies like mobile technology-that brings together students with diverse backgrounds from different academic units across the campus. MAD culminates in an industry-sponsored competition, where student teams present their mobile solution to a panel of expert judges from industry and higher education. Via MAD and the associated competitions, students, faculty, and institutional partners can explore the opportunities and challenges associated with mobile technologies. This paper discusses how problem-based learning principles guided the design and implementation of MAD. A multiperspective assessment of the success of MAD is offered. Finally, key lessons learned and guidance to assist other educators are also offered
Stochastic optimal growth with a non-compact state space

Abstract This paper studies the stability of a stochastic optimal growth economy introduced by Brock and Mirman [Brock, W.A., Mirman, L., 1972. Optimal economic growth and uncertainty: the discounted case. Journal of Economic Theory 4, 479–513] by utilizing stochastic monotonicity in a dynamic system. The construction of two boundary distributions leads to a new method of studying systems with non-compact state space. The paper shows the existence of a unique invariant distribution. It also shows the equivalence between the stability and the uniqueness of the invariant distribution in this dynamic system.
Inequality and Network Formation Games

Abstract This article addresses the matter of inequality in network formation games. We employ a quantity that we are calling the Nash Inequality Ratio (NIR), defined as the maximal ratio between the highest and lowest costs incurred to individual agents in a Nash equilibrium strategy, to characterize the extent to which inequality is possible in equilibrium. We give tight upper bounds on the NIR for the network formation games of Fabrikant et al. [14] and Ehsani et al. [13]. With respect to the relationship between equality and social efficiency, we show that, contrary to common expectations, efficiency does not necessarily come at the expense of increased inequality.
CMS Pixel Telescope Addition to T-980 Bent Crystal Collimation Experiment at the Tevatron

An enhancement to the T-980 bent crystal collimation experiment at the Tevatron has been completed. The enhancement was the installation of a pixel telescope inside the vacuum-sealed beam pipe of the Tevatron. The telescope is comprised of six CMS PSI46 pixel plaquettes, arranged as three stations of horizontal and vertical planes, with the CAPTAN system for data acquisition and control. The purpose of the pixel telescope is to measure beam profiles produced by bent crystals under various conditions. The telescope electronics inside the beam pipe initially were not adequately shielded from the image current of the passing beams. A new shielding approach was devised and installed, which resolved the problem. The noise issues encountered and the mitigating techniques are presented herein, as well as some preliminary results from the telescope.
Macroeconomic Linkages, Taxes, and Subsidies in the U.S. Agricultural Sector

LJ'~,AR{.~ : Division of Agricultural Sciences UNlVERSIlY OF CALIFORJ'HA MA.CROECONo~nc LINKAGES. T??\XES, AND SUBSIDIES IN TIIE U. S. AGR.: CUtTURAL SECl'OR by Gordon C. Rausser, James A. Chalfant, H. Alan Love, and Kostas G. Stamoulis .~~ ....:. : ~.:::.:Tt.~r~??i~f- r:~??~:;.' ~ :,,,; ~in.i jQ!lifor'~ia Agricultura: Experiment Station [clmoation of j\gricultural Economics ( January 1986
Reconfigurations in Graphs and Grids

Let $G$ be a connected graph, and let $V$ and $V'$ be two $n$-element subsets of its vertex set $V(G)$. Imagine that we place a chip at each element of $V$ and we want to move them into the positions of $V'$ ($V$ and $V'$ may have common elements). A move is defined as shifting a chip from $v_1$ to $v_2$ ($v_1,v_2 \in V(G)$) on a path formed by edges of $G$ so that no intermediate vertices are occupied. We give upper and lower bounds on the number of moves that are necessary and analyze the computational complexity of this problem under various assumptions: labeled versus unlabeled chips, arbitrary graphs versus the case when the graph is the rectangular (infinite) planar grid, etc. We prove hardness and inapproximability results for several variants of the problem. We also give a linear time algorithm which performs an optimal (minimum) number of moves for the unlabeled version in a tree, and a constant-ratio approximation algorithm for the unlabeled version in a graph. The graph algorithm uses the tree algorithm as a subroutine.
Price Flexibility and Output Stability: An Old Keynesian View

In this symposium I shall play the role in which I was cast, the unreconstructed old Keynesian. Considering the alternatives, I do not mind being billed as a Keynesian, an old Keynesian at that. But old Keynesians come in several varieties, and I speak for no one but myself. Nor do I defend the literal text of The General Theory. Several generations of economists have criticized, amended, and elaborated that seminal work. I shall argue for the validity of the major propositions that distinguish Keynesian macroeconomics from old or new classical macroeconomics.
Interferometric Astrometry of the Low-Mass Binary Gl 791.2 (= HU Del) Using HUBBLE SPACE TELESCOPE Fine Guidance Sensor 3: Parallax and Component Masses

With fourteen epochs of fringe-tracking data spanning 1.7 yr from Fine Guidance Sensor 3 we have obtained a parallax (πabs = 113.1 ± 0.3 mas) and perturbation orbit for Gl 791.2A. Contemporaneous fringe-scanning observations yield only three clear detections of the secondary on both interferometer axes. They provide a mean component magnitude difference, ΔV = 3.27 ± 0.10. The period (P = 1.4731 yr), from the perturbation orbit, and the semimajor axis (a = 0.963 ± 0.007 AU), from the measured component separations with our parallax, provide a total system mass MA + MB = 0.412 ± 0.009 M⊙. Component masses are MA = 0.286 ± 0.006 M⊙ and MB = 0.126 ± 0.003 M⊙. Gl 791.2A and Gl 791.2B are placed in a sparsely populated region of the lower main-sequence mass-luminosity relation where they help define the relation because the masses have been determined to high accuracy, with errors of only 2%.
Adaptive trellis-coded modulation for bandlimited meteor burst channels

The throughput performances of three adaptive information rate techniques on the bandlimited meteor burst channel are investigated. Closed-form expressions for throughput are derived based on the channel model commonly used in the literature. The throughput performance is compared to the conventional fixed information rate modem and upper bounds on throughput improvement over the fixed rate modem are derived. It is shown that an adaptive technique that uses trellis-coded modulation (TCM) with three phase-shift keyed (PSK) signal sets can increase throughput over the conventional fixed rate modem by more than a factor of 3. Data from the US Air Force High Latitude Meteor-Scatter Test Bed confirm the superiority of the adaptive TCM technique. A practical implementation is suggested that uses a single rate 1/2 convolutional code for all three PSK signal sets. The use of this single code, versus the three best Ungerboeck codes, results in a throughput loss of less than 2%. An expression for the theoretical information capacity of the bandlimited meteor burst channel is derived. >
Instrumental-Variable Estimation of Count Data Models: Applications to Models of Cigarette Smoking Behavior

As with most analyses involving microdata, applications of count data models must somehow account for unobserved heterogeneity. The count model literature has generally assumed that unobservables and observed covariates are statistically independent. Yet for many applications this independence assumption is clearly tenuous. When the unobservables are omitted variables correlated with included regressors, standard estimation methods will generally be inconsistent. Though alternative consistent estimators may exist in special circumstances, it is suggested here that a nonlinear instrumental-variable strategy offers a reasonably general solution to such estimation problems. This approach is applied in two examples that focus on cigarette smoking behavior.
Derating of induction motors due to waveform distortion

The detrimental effects of nonsinusoidal voltage on induction motor performance are described. The derating of induction motors due to harmonic distortion is discussed in detail. Derating of NEMA Design B induction motors of different output ratings and for two types of enclosures (drip-proof and totally enclosed) due to different cases of harmonic distortions are discussed. IEEE Standard 519 suggests that no derating of the motor would be necessary for a harmonic content of up to 5%. However, no limit is specified in regard to the individual harmonic content. The conclusion is that a restriction for the second harmonic should be included on the harmonic distortion limits established by the IEEE Guide for Harmonic Control and React Compensation of Static Pow Converters (ANSI/IEEE Standard 519, Apr. 1981), and derating in some cases should be considered for less than 5% harmonic distortion. Drip-proof machines are found to be less affected by harmonic distortion than totally enclosed machines. Efficiency plays an important role in the degree of derating. Less efficient machines would require a higher derating. It is also clear that smaller machines (less than 5 HP) are affected more by the harmonics than are larger machines. >
The High Volume Return Premium

The idea that extreme trading activity contains information about the future evolution of stock prices is investigated. We find that stocks experiencing unusually high ~low! trading volume over a day or a week tend to appreciate ~depreciate! over the course of the following month. We argue that this high-volume return premium is consistent with the idea that shocks in the trading activity of a stock affect its visibility, and in turn the subsequent demand and price for that stock. Return autocorrelations, firm announcements, market risk, and liquidity do not seem to explain our results. THE OBJECTIVE OF THIS PAPER is to investigate the role of trading activity in terms of the information it contains about future prices. More precisely, we are interested in the power of trading volume in predicting the direction of future price movements. We find that individual stocks whose trading activity is unusually large ~small! over periods of a day or a week, as measured by trading volume during those periods, tend to experience large ~small! returns over the subsequent month. In other words, a high-volume return premium seems to exist in stock prices. The essence of our paper’s results is captured in Figure 1. In this figure, we show the evolution of the average cumulative return of three groups of stocks: stocks that experienced unusually high, unusually low, and normal trading volume, relative to their recent history of trading volume, on the trading day preceding the portfolio formation date. We see that the stocks that experienced unusually high ~low! trading volume outperform ~are outperformed by! the stocks which had normal trading volume. Moreover, this effect appears to grow over time, especially for the high-volume stocks. We postulate that the high-volume premium is due to shocks in trader interest in a given stock, that is, the stock’s visibility. Miller ~1977! and
Wavelet analysis of satellite images for coastal watch

The two-dimensional wavelet transform is a very efficient bandpass filter, which can be used to separate various scales of processes and show their relative phase/location. In this paper, algorithms and techniques for automated detection and tracking of mesoscale features from satellite imagery employing wavelet analysis are developed. The wavelet transform has been applied to satellite images, such as those from synthetic aperture radar (SAR), advanced very-high-resolution radiometer (AVHRR), and coastal zone color scanner (CZCS) for feature extraction. The evolution of mesoscale features such as oil slicks, fronts, eddies, and ship wakes can be tracked by the wavelet analysis using satellite data from repeating paths. Several examples of the wavelet analysis applied to various satellite images demonstrate the feasibility of this technique for coastal monitoring.
Feature Learning by Multidimensional Scaling and Its Applications in Object Recognition

We present the MDS feature learning framework, in which multidimensional scaling (MDS) is applied on high-level pair wise image distances to learn fixed-length vector representations of images. The aspects of the images that are captured by the learned features, which we call MDS features, completely depend on what kind of image distance measurement is employed. With properly selected semantics-sensitive image distances, the MDS features provide rich semantic information about the images that is not captured by other feature extraction techniques. In our work, we introduce the iterated Levenberg-Marquardt algorithm for solving MDS, and study the MDS feature learning with IMage Euclidean Distance (IMED) and Spatial Pyramid Matching (SPM) distance. We present experiments on both synthetic data and real images - the publicly accessible UIUC car image dataset. The MDS features based on SPM distance achieve exceptional performance for the car recognition task.
Ectopic histone H3S10 phosphorylation causes chromatin structure remodeling in Drosophila

Histones are subject to numerous post-translational modifications that correlate with the state of higher-order chromatin structure and gene expression. However, it is not clear whether changes in these epigenetic marks are causative regulatory factors in chromatin structure changes or whether they play a mainly reinforcing or maintenance role. In Drosophila phosphorylation of histone H3S10 in euchromatic chromatin regions by the JIL-1 tandem kinase has been implicated in counteracting heterochromatization and gene silencing. Here we show, using a LacI-tethering system, that JIL-1 mediated ectopic histone H3S10 phosphorylation is sufficient to induce a change in higher-order chromatin structure from a condensed heterochromatin-like state to a more open euchromatic state. This effect was absent when a ;kinase dead' LacI-JIL-1 construct without histone H3S10 phosphorylation activity was expressed. Instead, the 'kinase dead' construct had a dominant-negative effect, leading to a disruption of chromatin structure that was associated with a global repression of histone H3S10 phosphorylation levels. These findings provide direct evidence that the epigenetic histone tail modification of H3S10 phosphorylation at interphase can function as a causative regulator of higher-order chromatin structure in Drosophila in vivo.
Critical Acceleration and Quantum Vacuum

Little is known about the physics frontier of strong acceleration; both classical and quantum physics need further development in order to be able to address this newly accessible area of physics. In this lecture we discuss what strong acceleration means, possible experiments using electron-laser collisions, and data available from ultra-relativistic heavy ion collisions. We review the foundations of the current understanding of charged particle dynamics in presence of critical forces and discuss the radiation reaction inconsistency in electromagnetic theory and the apparent relation with quantum physics and strong field particle production phenomena. The role of the quantum vacuum as an inertial reference frame is emphasized, as well as the absence of such a 'Machian' reference frame in the conventional classical limit of quantum field theory.
Wireless LAN: Past, Present, and Future

This paper retraces the historical development of wireless LAN technology in the context of the pursuit of ever higher data rate, describes the significant technical breakthroughs that are now occurring, and speculates on future directions that the technology may take over the remainder of the decade. The challenges that these developments have created for low power operation are considered, as well as some of the opportunities that are presented to mitigate them. The importance of MIMO as an emerging technology for IEEE 802.11 is specifically highlighted, both in terms of the significant increase in data rate and range that it enables as well as the considerable challenge that it presents for the development of low power wireless LAN products.
The triangle-free process

Consider the following stochastic graph process. We begin with G0, the empty graph on n vertices, and form Gi by adding a randomly chosen edge ei to Gi−1 where ei is chosen uniformly at random from the collection of pairs of vertices that neither appear as edges in Gi−1 nor form triangles when added as edges to Gi−1. Let the random variable M be the number of edges in the maximal triangle free graph generated by this process. We prove that asymptotically almost surely M=Θ(n3/2logn). This resolves a conjecture of Spencer. Furthermore, the independence number of GM is asymptotically almost surely Θ(nlogn), which implies that the Ramsey number R(3,t) is bounded below by a constant times t2/logt (a fact that was previously established by Jeong Han Kim). The methods introduced here extend to the K4-free process, thereby establishing the bound R(4,t)=Ω(t5/2/log2t).
Extractors and Lower Bounds for Locally Samplable Sources

We consider the problem of extracting randomness from sources that are efficiently samplable, in the sense that each output bit of the sampler only depends on some small number d of the random input bits. As our main result, we construct a deterministic extractor that, given any d-local source with min-entropy k on n bits, extracts Ω(k2/nd) bits that are 2−nΩ(1)-close to uniform, provided d ≤ o(log n) and k ≥ n2/3+γ (for arbitrarily small constants γ > 0).Using our result, we also improve a result of Viola [2010] who proved a 1/2 − O(1/log n) statistical distance lower bound for o(log n)-local samplers trying to sample input-output pairs of an explicit boolean function, assuming the samplers use at most n + n1−δ random bits for some constant δ > 0. Using a different function, we simultaneously improve the lower bound to 1/2 − 2−nΩ(1) and eliminate the restriction on the number of random bits.
Camp David: Was the agreement fair?

The agreement between Egypt and Israel at Camp David in 1978 is used to illustrate how a fair-division procedure called Adjusted Winner (AW), in which two sides allocate 100 points over the issues ...
Multiscale likelihood analysis and complexity penalized estimation

We describe here a framework for a certain class of multiscale likelihood factorizations wherein, in analogy to a wavelet decomposition of an L 2 function, a given likelihood function has an alternative representation as a product of conditional densities reflecting information in both the data and the parameter vector localized in position and scale. The framework is developed as a set of sufficient conditions for the existence of such factorizations, formulated in analogy to those underlying a standard multiresolution analysis for wavelets, and hence can be viewed as a multiresolution analysis for likelihoods. We then consider the use of these factorizations in the task of nonparametric, complexity penalized likelihood estimation. We study the risk properties of certain thresholding and partitioning estimators, and demonstrate their adaptivity and near-optimality, in a minimax sense over a broad range of function spaces, based on squared Hellinger distance as a loss function. In particular, our results provide an illustration of how properties of classical wavelet-based estimators can be obtained in a single, unified framework that includes models for continuous, count and categorical data types.
The Buchanan-Tullock model: Some extensions

In their seminal work, The Calculus of Consent (1962), Buchanan and Tullock develop a decision model which embodies fundamental relation­ships relevant to institutional choices. However, the Buchanan-Tullock model remains "general," thus inviting others to specify details and to develop extensions. The present paper seeks to explicate this important model so as to clarify the framework in certain important ways and then to extend the model by introducing explicit considerations of such dimensions as group size and group preference heterogeneity as explicit variables.
Free energy periodicity in E. coli coding

Sequences upstream from coding regions in E. coli commonly possess significant complementarity to the exposed part of the 16S rRNA. This region is known as the Shine-Dalgarno sequence. Free energy calculations for binding between homologous sequences suggest that this region is used as a landing site for construction of the ribosome around the mRNA. While strong upstream binding appears to be a condition for translation, it may not be sufficient. The authors' research suggests that the 16S has a continuing role throughout translation, particularly in ribosomal synchronization with the reading frame. The authors consider the entire E. coli genome of over 2000 forward coding sequences. Presence of strong upstream binding is confirmed, and a definite three-base periodic signal is observed. The distribution of bases parallels that needed to produce a signal of the type observed.
Forecasting Methods in Crime and Justice

Researchers who study crime and justice have been forecasting a variety of outcomes for nearly a century. Perhaps the most well known are forecasts of behavior after release from prison. Other examples include forecasts of prison populations and time trends in crime. However, it is very difficult to determine how accurate such forecasts have been because few forecasts have been properly evaluated. In the hope of improving crime and justice forecasts in the future, this article reviews modern forecasting methods and their applications to crime and justice questions. Among the key challenges for researchers are how best to arrive at useful forecasting models, taking the costs of forecasting errors into account, and estimating nonlinear relationships.
Expected message delivery time for small-world networks in the continuum limit

Small-world networks are networks in which the graphical diameter of the network is as small as the diameter of random graphs but whose nodes are highly clustered when compared with the ones in a random graph. Examples of small-world networks abound in sociology, biology, neuroscience and physics as well as in human-made networks. This paper analyzes the average delivery time of messages in dense small-world networks constructed on a plane. Iterative equations for the average message delivery time in these networks are provided for the situation in which nodes employ a simple greedy geographic routing algorithm. It is shown that two network nodes communicate with each other only through their short-range contacts, and that the average message delivery time rises linearly if the separation between them is small. On the other hand, if their separation increases, the average message delivery time rapidly saturates to a constant value and stays almost the same for all large values of their separation.
Reliability analysis of artificial neural networks

Neural network technology has been applied to a variety of science and engineering problems that involve the extraction of useful information from complex uncertain data. The problem of estimating the reliability of a neural network is discussed. Reliability is defined as the probability that a correct output is produced by the neural network, even though some of the constituent components have failed. The methodology described is applicable to a large variety of neural networks, and can incorporate a number of alternative failure models. An example network is analyzed to show the effect of component failures and the number of training patterns on reliability. Simple methods to improve reliability are investigated. >
The informational value of Toxics Release Inventory performance

Purpose – The study aims to evaluate the informational value to investors of the Toxics Release Inventory (TRI) as an external outcome measure of corporate environmental performance. Emphasis is placed on the market response differences between three highly polluting industries.Design/methodology/approach – The study uses pooled cross‐sectional, time‐series data and an event study methodology to examine the effects of TRI emissions on abnormal market returns.Findings – There is empirical evidence that market reactions to TRI emissions information vary by industry. Investors reward decreases in emissions in the electric utility industry, but do not penalize increases. In the chemical industry, increases in emissions are penalized, but decreases are not rewarded. Models do not capture any reaction to emissions changes in the pulp and paper industry. These results may be explained by the significant difference between industries in the US percentage of total firm sales.Research limitations/implications – Thi...
Particle acceleration in relativistic collisionless shocks: Fermi process at last?

We present evidence that relativistic shocks propagating in unmagnetized plasmas can self-consistently accelerate particles. We use long-term two-dimensional particle-in-cell simulations to study the well-developed shock structure in unmagnetized pair plasma. The particle spectrum downstream of such a shock consists of two components: a relativistic Maxwellian, with a characteristic temperature set by the upstream kinetic energy of the flow, and a high-energy tail, extending to energies >100 times that of the thermal peak. This high-energy tail is best fitted as a power law in energy with index –2.4 ± 0.1, modified by an exponential cutoff. The cutoff moves to higher energies with time of the simulation, leaving a larger power-law range. The number of particles in the tail is ~1% of the downstream population, and they carry ~10% of the kinetic energy in the downstream region. Investigating the trajectories of particles in the tail, we find that the energy gains occur as particles bounce between the upstream and downstream regions in the magnetic fields generated by the Weibel instability. We compare this mechanism to the first-order Fermi acceleration and set a lower limit on the efficiency of the shock acceleration process.
A Markov random field model-based approach to image interpretation

An image is segmented into a collection of disjoint regions that form the nodes of an adjacency graph, and image interpretation is achieved through assigning object labels (or interpretations) to the segmented regions (or nodes) using domain knowledge, extracted feature measurements, and spatial relationships between the various regions. The interpretation labels are modeled as a Markov random field (MRF) on the corresponding adjacency graph, and the image interpretation problem is then formulated as a maximum a posteriori (MAP) estimation rule, given domain knowledge and region-based measurements. Simulated annealing is used to find this best realization or optimal MAP interpretation. This approach also provides a systematic method for organizing and representing domain knowledge through appropriate design of the clique functions describing the Gibbs distribution representing the pdf of the underlying MRF. A general methodology is provided for the design of the clique functions. Results of image interpretation experiments on synthetic and real-world images are described. >
A critical assessment of viscous models of trench topography and corner flow

Stresses for Newtonian viscous flow in a simple geometry (e.g., corner flow, bending flow) are obtained in order to study the effect of imposed velocity boundary conditions. Stress for a delta function velocity boundary condition decays as 1/R(2); for a step function velocity, stress goes as 1/R; for a discontinuity in curvature, the stress singularity is logarithmic. For corner flow, which has a discontinuity of velocity at a certain point, the corresponding stress has a 1/R singularity. However, for a more realistic circular-slab model, the stress singularity becomes logarithmic. Thus the stress distribution is very sensitive to the boundary conditions, and in evaluating the applicability of viscous models of trench topography it is essential to use realistic geometries. Topography and seismicity data from northern Hoshu, Japan, were used to construct a finite element model, with flow assumed tangent to the top of the grid, for both Newtonian and non-Newtonian flow (power law 3 rheology). Normal stresses at the top of the grid are compared to the observed trench topography and gravity anomalies. There is poor agreement. Purely viscous models of subducting slables with specified velocity boundary conditions do not predict normal stress patterns compatible with observed topography and gravity. Elasticity and plasticity appear to be important for the subduction process.
A Nonlinear GaAs FET Model for Use in the Design of Output Circuits for Power Amplifiers

A nonlinear equivalent circuit model for the GaAs FET has been developed based upon the small-signal device model and separate current measurements, including drain-gate avalanche current data. The harmonic-balance technique is used to develop the FET RF load-pull characteristics in an amplifier configuration under large-signal operation. Computed and experimental load-pull results show good agreement.
On optimal traffic grooming in WDM rings

We consider the problem of designing a virtual topology to minimize electronic routing, that is, grooming traffic, in wavelength routed optical rings. The full virtual topology design problem is NP-hard even in the restricted case where the physical topology is a ring, and various heuristics have been proposed in the literature for obtaining good solutions, usually for different classes of problem instances. We present a new framework which can be used to evaluate the performance of heuristics and which requires significantly less computation than evaluating the optimal solution. This framework is based on a general formulation of the virtual topology problem, and it consists of a sequence of bounds, both upper and lower, in which each successive bound is at least as strong as the previous one. The successive bounds take larger amounts of computation to evaluate, and the number of bounds to be evaluated for a given problem instance is only limited by the computational power available. The bounds are based on decomposing the ring into sets of nodes arranged in a path and adopting the locally optimal topology within each set. While we only consider the objective of minimizing electronic routing in this paper, our approach to obtaining the sequence of bounds can be applied to many virtual topology problems on rings. The upper bounds we obtain also provide a useful series of heuristic solutions.