cssi/SciSciGPT-SciSciNet huggingface dataset:
Assessment of resident and fellow knowledge of the organ donor referral process.

Maximizing deceased donation rates can decrease the organ shortage. Non-transplant physicians play a critical role in facilitating conversion of potential deceased donors to actual donors, but studies suggest that physicians lack knowledge about the organ donation process. As residency and fellowship are often the last opportunities for formal medical training, we hypothesized that deficiencies in knowledge might originate in residency and fellowship. We conducted a cross-sectional survey to assess knowledge about organ donation, experience in donor conversion, and opinions of the process among residents and fellows after their intensive care unit rotations at the Johns Hopkins Hospital. Of 40 participants, 50% had previously facilitated donor conversion, 25% were familiar with the guidelines of the organ procurement organization (OPO), and 10% had received formal instruction from the OPO. The median score on the knowledge assessment was five of 10; higher knowledge score was not associated with level of medical training, prior training in or experience with donor conversion, or with favorable opinions about the OPO. We identified a pervasive deficit in knowledge among residents and fellows at an academic medical center with an active transplant program that may help explain attending-level deficits in knowledge about the organ donation process.
Jets and Tori in Proto-Planetary Nebulae

We investigate the time sequence for the appearance of jets and molecular tori in the transition of stars from the asymptotic giant branch to the planetary nebula phase. Jets and tori are prominent features of this evolution, but their origins are uncertain. Using optical and millimeter line kinematics, we determine the ejection history in a sample of well-observed cases. We find that jets and tori develop nearly simultaneously. We also find evidence that jets typically appear slightly later than tori, with a lag time of a few hundred years. These characteristics provide strong evidence that jets and tori are physically related, and they set new constraints on theories of jet formation. The ejection of a discrete torus followed by jets on a short timescale favors the class of models in which a companion interacts with the central star. Models with long timescales, or with jets followed by a torus, are ruled out.
EVALUATING ALTERNATIVE FARMING SYSTEMS: A FUZZY MADM APPROACH

This paper develops a decision support method that integrates measures of achievement in the economic, environmental, and social aspects of farming. The decision support method combines multiple attribute decision making (MADM) with fuzzy logic. The fuzzy MADM model fully ranks decision alternatives relative to the preferences of decision makers and overcomes several problems inherent in other MADM approaches. It is concluded that fuzzy MADM can improve decision making on the farm.
Effect of Ta2O5, Nb2O5, and HfO2 Alloying on the Transformability of Y2O3-Stabilized Tetragonal ZrO2

The addition of Ta{sub 2}O{sub 5}, Nb{sub 2}O{sub 5}, and HfO{sub 2} enhanced the transformability of Y{sub 2}O{sub 3}-stabilized tetragonal ZrO{sub 2} polycrystal (Y-TZP), which was indicated by an increase in phase transformation temperatures and fracture toughness of Y-TZP. Comparison of the alloying effects of these oxides on the transformability and crystal structure of Y-TZP suggested that an alloying oxide which increases the c/a axial ratio (tetragonality) of TZP also increases the transformability. Empirical equations to predict the tetragonality are proposed. Calculated tetragonalities showed good agreement with measured values in the systems ZrO{sub 2}-Y{sub 2}O{sub 3}-Ta{sub 2}O{sub 5}, -Nb{sub 2}O{sub 5}, and -HfO{sub 2}.
Chandra and XMM - Newton detection of large-scale diffuse X-ray emission from the Sombrero galaxy

We present an X-ray study of the massive edge-on Sa galaxy, Sombrero (M 104; NGC 4594), based on XMM-Newton and Chandra observations. A list of 62 XMM-Newton and 175 Chandra discrete X-ray sources is provided, the majority of which are associated with the galaxy. Spectral analysis is carried out for relatively bright individual sources and for an accumulated source spectrum. At energies & 2 keV, the source-subtracted X-ray emission is distributed similarly as the stellar K-band light and is primarily due to the residual emission from discrete sources. At lower energies, however, a substantial fraction of the source-subtracted emission arises from diffuse hot gas extending to � 20 kpc from the galactic center. The galactic disk shows little X-ray emission and instead shadows part of the X-ray radiation from the bulge. The observed diffuse X-ray emission from the galaxy shows a steep spectrum that can be characterized by an optically-thin thermal plasma with temperatures of � 0.6-0.7 keV, varying little with radius. The diffuse emission has a total luminosity of � 3 × 10 39 erg s −1 in the 0.2-2 keV energy range. This luminosity is significantly smaller than the prediction by current numerical simulations for galaxies as massive as Sombrero. However, such simulations do not include the effect of quienscent stellar feedback (e.g., ejecta from evolving stars and Type Ia supernovae) against the accretion from intergalactic medium. We argue that the stellar feedback likely plays an essential role in regulating the physical properties of hot gas. Indeed, the observed diffuse X-ray luminosity of Sombrero accounts for at most a few percent of the expected mechanical energy input from Type Ia supernovae. The inferred gas mass and metal content are also substantially less than those expected from stellar ejecta. We speculate that a galactic bulge wind, powered primarily by Type Ia supernovae, has removed much of the “missing” energy and metal-enriched gas from the region revealed by the X-ray observations.
Strategic Business Fits and Corporate Acquisition: Empirical Evidence

A sample of 218 mergers made by randomly selected bidders during 1962 to 1983 is classified by changes in the product market opportunities of the bidder firms. Multivariate regression analysis shows that acquisitions which permit the bidder access to new but related markets create the most value with the least variance.
Influence diagrams for capacity planning and pricing under uncertainty

ABSTRACT: Influence diagrams are presented as a complement to analytical methods for solving capacity‐planning and pricing problems under uncertainty. An influence diagram model that permits continuous decision variables is used to determine optimal decision rules for a single product monopolist making capacity and price selections once per period. Solutions under different scenarios based on the timing of actual demand observations and the ability to adjust initial capacity are compared to previous solutions in the literature. The results demonstrate that optimal decision rules for capacity and price determined using influence diagrams closely approximate those found using analytical approaches. The influence diagram is used to determine the effect of changing demand function parameters on the optimal solutions. Additionally, the influence diagram model can be adapted to solve capacity‐planning problems that do not meet the assumptions required to obtain analytical solutions or heuristics in previous stu...
NON-RIGIDITY OF CYCLIC AUTOMORPHIC ORBITS IN FREE GROUPS

We say a subset Σ ⊆ FN of the free group of rank N is spectrally rigid if whenever T1, T2 ∈ cvN are ℝ-trees in (unprojectivized) outer space for which ‖σ‖T1 = ‖σ‖T2 for every σ ∈ Σ, then T1 = T2 in cvN. The general theory of (non-abelian) actions of groups on ℝ-trees establishes that T ∈ cvN is uniquely determined by its translation length function ‖⋅‖T : FN → ℝ, and consequently that FN itself is spectrally rigid. Results of Smillie and Vogtmann, and of Cohen, Lustig and Steiner establish that no finite Σ is spectrally rigid. Capitalizing on their constructions, we prove that for any Φ ∈ Aut(FN) and g ∈ FN, the set Σ = {Φn(g)}n∈ℤ is not spectrally rigid.
Seismic-induced architectural damage to masonry structures at Mercury, Nevada

Forty-three masonry structures in Mercury, Nevada were inspected for cracking before and after nuclear detonations at the Nevada Test Site, at distances of from 33 to 78 km from Mercury. The same buildings were inspected during periods of no significant nuclear activity. Findings include evidence that peak-particle velocities of 0.1 to 0.3 cm/sec caused, on the average, 24 cracks in the 43 buildings, as compared to about 2.5 cracks during a similar time span of no nuclear activity. Cracks at these low levels of motion are not more severe than those occurring naturally.
Mass problems and intuitionistic higher-order logic

In this paper we study a model of intuitionistic higher-order logic which we call the Muchnik topos. The Muchnik topos may be defined briefly as the category of sheaves of sets over the topological space consisting of the Turing degrees, where the Turing cones form a base for the topology. We note that our Muchnik topos interpretation of intuitionistic mathematics is an extension of the well known Kolmogorov/Muchnik interpretation of intuitionistic propositional calculus via Muchnik degrees, i.e., mass problems under weak reducibility. We introduce a new sheaf representation of the intuitionistic real numbers, the Muchnik reals, which are different from the Cauchy reals and the Dedekind reals. Within the Muchnik topos we obtain a choice principle (8x9y A(x,y)) ) 9w 8xA(x,wx) and a bound
Understanding How Price Responds to Costs and Production

Abstract The importance of sticky prices in business-cycle fluctuations has been debated for many years. But we argue, based on a large empirical literature from the 1950s and 60s, that it is necessary to distinguish the response of price to an increase in factor prices from its response to an increase in marginal cost generated by an expansion in production. Consistent with that earlier literature, we find for 450 U.S. manufacturing industries that prices do respond more to increases in costs driven by changes in factor prices than to increases in marginal cost precipitated by expansions in output. We explore two models that can potentially explain these findings. Both break the link between price and marginal cost, thereby generating what one might naively interpret as average-cost pricing. The first is driven by firms pricing to limit entry. The second is driven by firms pricing to limit non-price competition within their market.
Analysis of Kinematic Waves Arising in Diverging Traffic Flow Models

Diverging junctions are important network bottlenecks, and a better understanding of diverging traffic dynamics has both theoretical and practical implications. In this paper, we present a new framework for constructing kinematic wave solutions to the Riemann problem of kinematic wave models of diverging traffic with jump initial conditions. Within this framework, the function space of weak solutions is enlarged to include interior states that occur with stationary discontinuities, and various discrete flux functions in cell transmission models of diverging traffic are used as entropy conditions to pick out unique physical solutions. Then in demand-supply space, we prove that the Riemann problem can be uniquely solved for existing discrete flux functions, in the sense that stationary states and, therefore, shock or rarefaction waves on all links, can be uniquely determined under given initial conditions. We show that the two diverge models by Lebacque and Daganzo are asymptotically equivalent. We also prove that the supply proportional and priority-based diverge models are locally optimal evacuation strategies. With numerical examples, we demonstrate the validity of the analytical solutions of interior states, stationary states, and corresponding kinematic waves. This study presents a unified framework for analyzing traffic dynamics arising at diverging junctions and could be helpful for developing emergency evacuation strategies.
Measuring the Aperture and Locating Beam Obstructions in the Fermilab Accelerator

A method which uses the coasting beam at the injection energy to scan the aperture in a large accelerator such as the Main Accelerator at Fermilab will be described. This scanning procedure serves two purposes. It provides a record of the aperture size around the entire accelerator which can be used for future reference and comparison. And it is highly useful in locating beam obstructions which may be caused by a collapsed vacuum chamber or some small object in the chamber to within a few meters. A high degree of accuracy has been achieved in finding and removing even very small obstructions. This method uses several computer programs, the main accelerator correction dipoles and beam position detectors, and some simple calculations.
Adverbial, descriptive reciprocals

Reciprocity was a topic very much on the minds of New Yorkers in the mid­ seventies. Fiengo & Lasnik, Dougherty, Katz, and Langendoen worried, for example, that the state of mutual respect asserted in ( 1 ) implies warm feelings between any two family members, but the actions that these feelings lead to can­ and, in this example, mustfall short of every family member kneeling at every other family member 's grave.
Cone and seed trait variation in whitebark pine (Pinus albicaulis; Pinaceae) and the potential for phenotypic selection.

Phenotypic variation among individuals is necessary for natural selection to operate and is therefore essential for adaptive evolution. However, extensive variation within individuals can mask variation among individuals and weaken the potential for selection. Here we quantify variation among and within individuals in female cone and seed traits of whitebark pine ( Pinus albicaulis ). In many plants, the production of numerous reproductive structures creates the potential for considerable variation within a plant, but these same traits should also undergo strong selection because of their direct link to plant fi tness. We found about twice as much variation among individuals (overall mean = 65.3 ± 4.5% SE) than within individuals (overall mean = 34.7 ± 4.5%). One only needs to sample three to ficones per tree to accurately assess variation among trees in most cone and seed traits. The ease at which trees can be assessed helps account for the strong and consistent patterns of phenotypic selection exerted by seed predators and dispersers of whitebark pine and many other conifers. In contrast, the few traits where variation within trees equaled or exceeded that among trees underwent weak if any phenotypic selection.
The quest for the ideal inorganic scintillator

The past half century has witnessed the discovery of many new inorganic scintillator materials and numerous advances in our understanding of the basic physical processes governing the transformation of ionizing radiation into scintillation light. Whereas scintillators are available with a good combination of physical properties, none provides the desired combination of stopping power, light output, and decay time. A review of the numerous scintillation mechanisms of known inorganic scintillators reveals why none of them is both bright and fast. The mechanisms of radiative recombination in wide-band gap direct semiconductors, however, remain relatively unexploited for scintillators. We describe how suitably doped semiconductor scintillators could provide a combination of high light output, short decay time, and linearity of response that approach fundamental limits.
The Unpredictability of the Most Energetic Solar Events

Observations over the past two solar cycles show a highly irregular pattern of occurrence for major solar flares, γ-ray events, and solar energetic particle (SEP) fluences. Such phenomena do not appear to follow the direct indices of solar magnetic activity, such as the sunspot number. I show that this results from the non-Poisson occurrence for the most energetic events. This Letter also points out a particularly striking example of this irregularity in a comparison between the declining phases of the recent two solar cycles (1993-1995 and 2004-2006, respectively) and traces it through the radiated energies of the flares, the associated SEP fluences, and the sunspot areas. These factors suggest that processes in the solar interior involved with the supply of magnetic flux up to the surface of the Sun have strong correlations in space and time, leading to a complex occurrence pattern that is presently unpredictable on timescales longer than active region lifetimes (weeks) and not correlated well with the solar cycle itself.
Heterogeneity and Tests of Risk Sharing

How well do people share risk? Standard risk-sharing regressions assume that any variation in households’ risk preferences is uncorrelated with variation in the cyclicality of income. I combine administrative and survey data to show that this assumption is questionable: Risk-tolerant workers hold jobs in which earnings carry more aggregate risk. The correlation makes risk-sharing regressions in the previous literature too pessimistic. I derive techniques that eliminate the bias, apply them to U.S. data, and find that the effect of idiosyncratic income shocks on consumption is practically small and statistically difficult to distinguish from zero.
Trends prediction using social diffusion models

The importance of the ability to predict trends in social media has been growing rapidly in the past few years with the growing dominance of social media in our everyday's life. Whereas many works focus on the detection of anomalies in networks, there exist little theoretical work on the prediction of the likelihood of anomalous network pattern to globally spread and become "trends". In this work we present an analytic model for the social diffusion dynamics of spreading network patterns. Our proposed method is based on information diffusion models, and is capable of predicting future trends based on the analysis of past social interactions between the community's members. We present an analytic lower bound for the probability that emerging trends would successfully spread through the network. We demonstrate our model using two comprehensive social datasets -- the Friends and Family experiment that was held in MIT for over a year, where the complete activity of 140 users was analyzed, and a financial dataset containing the complete activities of over 1.5 million members of the eToro social trading community.
Theory of structural glasses and supercooled liquids.

AbstractWe review the random first-order transition theory of the glass transition, emphasizing the experimental tests of the theory. Many distinct phenomena are quantitatively predicted or explained by the theory, both above and below the glass transition temperature Tg. These include the following: the viscosity catastrophe and heat-capacity jump at Tg, and their connection; the nonexponentiality of relaxations and their correlation with the fragility; dynamic heterogeneity in supercooled liquids owing to the mosaic structure; deviations from the Vogel-Fulcher law, connected with strings or fractal cooperative rearrangements; deviations from the Stokes-Einstein relation close to Tg; aging and its correlation with fragility; and the excess density of states at cryogenic temperatures owing to two-level tunneling systems and the Boson peak.
Beyond Google and evil: How policy makers, journalists and consumers should talk differently about Google and privacy

Google has come to symbolize the tensions between the benefits of innovative, information-dependent new services and the desire of individuals to control the contexts in which personal information is used. This essay reviews hundreds of newspaper articles where Google speaks about privacy in an effort to characterize the company’s handling of these tensions, to provide context explaining the meaning of the company’s privacy rhetoric, and to advance the privacy dialogue among policy makers, journalists, and consumers. The dialogue surrounding these tensions is unfocused because many policy makers, journalists, and consumers concentrate the debate on whether the company violates its “you can make money without doing evil” corporate motto. This first observation flows to a second: Google’s conception of “evil” is tied to the revolution the company brought about in advertising practices, practices that many think are mainstream now. Google is thus missing opportunities to remind the public that its advertising policies have several strong pro-consumer aspects, many of which are lost when “evil talk” is employed. Third, vague privacy rhetoric signals a weak commitment to technical or legal safeguards. Journalists are well suited to remedy this by exercising greater inquiry and skepticism in contexts where Google’s privacy representations are non-substantive. Finally, Google heavily relies upon appeals to competition, arguing that those who adopt the company’s services engage in meaningful tradeoffs. Quietly shifting practices, lock in, and lengthy data retention periods, however, mean that these tradeoffs must be continually reevaluated. Google should give voice to its competition and tradeoff rhetoric by creating data portability and deletion rights for consumers.
Practical synthesis of chiral 9,9'-spirobixanthene-1,1'-diol.

A concise four-step synthesis of 9,9′-spirobixanthene-1,1′-diol is reported, featuring a practical preparation at large scale without the use of column chromatography purification. Co-crystallization with N-benzylcinchonidinium chloride and N-benzylquininium chloride rendered the optically pure product in both enantiomers.
Discrete Morse theory and the consecutive pattern poset

We use discrete Morse theory to provide another proof of Bernini, Ferrari, and Steingrimsson's formula for the Mobius function of the consecutive pattern poset. In addition, we are able to determine the homotopy type of this poset. Earlier, Bjorner determined the Mobius function and homotopy type of factor order and the results are remarkably similar to those in the pattern case. In his thesis, Willenbring used discrete Morse theory to give an illuminating proof of Bjorner's result. Since our proof parallels Willenbring's, we also consider the relationship between the two posets. In particular, we show that some of their intervals are isomorphic, and also that there is a sequence of posets interpolating between the two all of whom have essentially the same Mobius function.
Skill differentiation and wage disparity in a decentralized matching model of North–South trade

This paper develops a North-South trade model in which the South produces food and the North produces both food and a high-tech good. Food production is undertaken by unskilled workers while the high-tech product is made only by horizontally differentiated skilled workers. Due to the possibility of a peergroup effect, we allow the unskilled workers in the North to be equally or more productive than in the South. Horizontal matching of skilled workers is generally imperfect and the skilled wages are determined by a symmetric Nash bargain. We characterize two different types of equilibrium: a closed-economy equilibrium without trade and a free trade equilibrium without labor mobility. We then extend the benchmark framework to consider the presence of transport costs. In all cases with trade, the equilibrium properties of goods pricing, the volume of trade and wage disparities are examined.
A proof of the Breuil-Schneider conjecture in the indecomposable case

This paper contains a proof of a conjecture of Breuil and Schneider on the existence of an invariant norm on any locally algebraic representation of GL(n), with integral central character, whose smooth part is given by a generalized Steinberg representation. In fact, we prove the analogue for any connected reductive group G. This is done by passing to a global setting, using the trace formula for an R-anisotropic model of G. The ultimate norm comes from classical p-adic modular forms.
Discovering social circles in ego networks

People's personal social networks are big and cluttered, and currently there is no good way to automatically organize them. Social networking sites allow users to manually categorize their friends into social circles (e.g., “circles” on Googlep, and “lists” on Facebook and Twitter). However, circles are laborious to construct and must be manually updated whenever a user's network grows. In this article, we study the novel task of automatically identifying users' social circles. We pose this task as a multimembership node clustering problem on a user's ego network, a network of connections between her friends. We develop a model for detecting circles that combines network structure as well as user profile information. For each circle, we learn its members and the circle-specific user profile similarity metric. Modeling node membership to multiple circles allows us to detect overlapping as well as hierarchically nested circles. Experiments show that our model accurately identifies circles on a diverse set of data from Facebook, Googlep, and Twitter, for all of which we obtain hand-labeled ground truth.
Early evolution of stellar groups and clusters: environmental effects on forming planetary systems

This paper studies the dynamical evolution of young groups/clusters, with N = 100-1000 members, from their embedded stage out to ages of ~10 Myr. We use N-body simulations to explore how their evolution depends on the system size N and the initial conditions. Motivated by recent observations suggesting that stellar groups begin their evolution with subvirial speeds, this study compares subvirial starting states with virial starting states. Multiple realizations of equivalent cases (100 simulations per initial condition) are used to build up a robust statistical description of these systems, e.g., the probability distribution of closest approaches, the mass profiles, and the probability distribution for the radial location of cluster members. These results provide a framework from which to assess the effects of groups/clusters on the processes of star and planet formation and to study cluster evolution. The distributions of radial positions are used in conjunction with the probability distributions of the expected far-ultraviolet (FUV) luminosities (calculated here as a function of cluster size N) to determine the radiation exposure of circumstellar disks. The distributions of closest approaches are used in conjunction with scattering cross sections (calculated here as a function of stellar mass using ~105 Monte Carlo scattering experiments) to determine the probability of disruption for newly formed solar systems. We use the nearby cluster NGC 1333 as a test case in this investigation. The main conclusion of this study is that clusters in this size range have only a modest effect on forming planetary systems. The interaction rates are low, so that the typical solar system experiences a single encounter with closest approach distance b ~ 1000 AU. The radiation exposure is also low, with median FUV flux G0 ~ 900 (1.4 ergs s-1 cm-2), so that photoevaporation of circumstellar disks is only important beyond 30 AU. Given the low interaction rates and modest radiation levels, we suggest that solar system disruption is a rare event in these clusters.
Gallium-67-Citrate Scanning of Renal Parenchymal Malacoplakia

UNLABELLED The purpose of this article is to review the potential role of nuclear medicine scanning, especially with 67Ga, in the presumptive diagnosis and clinical management of patients with renal parenchymal malacoplakia (RPMP), a rare disease associated with coliform bacterial infection of the kidney and characterized by chronic unresolving inflammatory infiltrates containing von Hansemann macrophages in the renal parenchyma. METHODS Published cases of RPMP were collected from the archival literature by searching the MEDLINE database and by reviewing bibliographic references contained in articles on malacoplakia. Data on the clinical features and radiographic evaluation of patients with RPMP were extracted from the clinical case reports. RESULTS Forty-three cases of RPMP published over the past 20 yr were identified. Ten of the 43 patients (23%) had 67Ga scanning as a component of their diagnostic evaluation. In all 10 patients, renal uptake of 67Ga was classified as intense. Two of those 10 patients had serial 67Ga scanning performed to assess response to antibiotic treatment; both patients exhibited decreased uptake or complete resolution of abnormal renal uptake over time, a finding also exhibited by our patient. CONCLUSION Intense renal uptake of 67Ga, typically in the clinical setting of fever, progressive renal failure and nephromegaly, strongly supports a diagnosis of RPMP. In those patients receiving prolonged antimicrobial therapy for RPMP, resolution of abnormal 67Ga uptake over time may provide an objective endpoint for treatment.
Transcribing spacetime data into matrices

In certain supergravity backgrounds, D0 branes may polarize into higher dimensional Dp branes. We study this phenomenon in some generality from the perspective of a local inertial observer and explore polarization effects resulting from tidal-like forces. We find D2 brane droplets made of D0 branes at an extremum of the Born-Infeld action even in scenarios where the RR fields may be zero. These solutions lead us to a local formulation of the UV-IR correspondence. A holographic Planck scale bound on the number of D0 branes plays an important role in the analysis. We focus on the impact of higher order moments of background fields and work out extensions of the non-commutative algebra beyond the Lie and Heisenberg structures. In this context, it appears that q-deformed algebras come into play.
Decomposition of Direct Images of Logarithmic Differentials

The purpose of this note is to give a short proof of a theorem of Koll\'ar that the derived direct image of the canonical sheaf splits into a sum of its cohomology sheaves. This is deduced from a stronger decomposition theorem for direct images of sheaves of logarithmic differentials, together with the weak semistable reduction theorem.
Stochastic Technology, Risk Preferences, and Adoption of Site-Specific Technologies

A model of farmer decision making is developed to determine the extent to which uncertainties about soil fertility and weather affect the value of site-specific technologies (SSTs) using jointly estimated risk and technology parameters. Uncertainty can lead risk-averse farmers to apply more fertilizers and generate more pollution than in the certainty case. Ignoring uncertainty and risk aversion would overestimate the economic and environmental benefits of SSTs and underestimate the subsidy required to induce adoption. Accounting for uncertainties and risk preferences might explain the low observed adoption rates of SSTs. Improving the accuracy of SSTs would increase the incentives for adoption.
Prediction of multiple binding modes of the CDK2 inhibitors, anilinopyrazoles, using the automated docking programs GOLD, FlexX, and LigandFit: an evaluation of performance.

Anilinopyrazoles as CDK2 inhibitors can adopt multiple binding modes depending on the substituents at the 5-position of the pyrazole ring, based on CDK2/cyclin A crystallographic studies. Three commercially available docking programs, FlexX, GOLD, and LigandFit, were tested with 63 anilinopyrazole analogues in an attempt to reproduce the binding modes observed in the crystal structures. Each docking program gave different ligand conformations depending on the scoring or energy functions used. FlexX/drugscore, GOLD/chemscore, and LigandFit/plp were the best combinations of each docking program in reproducing the ligand conformations observed in the crystal structures. The 63 analogues were divided into two groups, type-A and type-B, depending on the substituent at the 5-position of the pyrazole ring. Although an alternate binding mode, observed in a crystal structure of one type-B compound, could not be reproduced with any of the above docking/scoring combinations, GOLD, with a template constraint based on...
Temperature-dependent behavior of confined many-electron systems in the Hartree-Fock approximation

Many-electron systems confined at substantial finite temperatures and densities present a major challenge to density functional theory. In particular, there is comparatively little systematic knowledge about the behavior of free-energy density functionals for temperatures and pressures of interest, for example, in the study of warm dense matter (WDM). As with ground-state functionals, development of approximate free-energy functionals is faced with significant needs for reliable assessment and calibration data. Here we address, in part, this need for detailed results on well-characterized systems. We present results on a comparatively simple, well-defined, computationally feasible but previously unexplored model, the thermal Hartree-Fock approximation. We discuss the main technical tasks (defining a suitable basis and evaluation of the required matrix elements) and give an illustrative initial application that probes both the content of the model and the solution techniques: a system of eight one-electron atoms with nuclei at fixed, arbitrary positions in a hard-walled box. Even this simple system produces physical behavior different from that produced by simple ground-state density functionals used at finite temperature (a common approximation in the study of WDM).
Determining the dimension of iterative Hessian transformation

The central mean subspace (CMS) and iterative Hessian transformation (IHT) have been introduced recently for dimension reduction when the conditional mean is of interest. Suppose that X is a vector-valued predictor and Y is a scalar response. The basic problem is to find a lower-dimensional predictor η T X such that E(Y|X) = E(Y|η T X). The CMS defines the inferential object for this problem and IHT provides an estimating procedure. Compared with other methods, IHT requires fewer assumptions and has been shown to perform well when the additional assumptions required by those methods fail. In this paper we give an asymptotic analysis of IHT and provide stepwise asymptotic hypothesis tests to determine the dimension of the CMS, as estimated by IHT. Here, the original IHT method has been modified to be invariant under location and scale transformations. To provide empirical support for our asymptotic results, we will present a series of simulation studies. These agree well with the theory. The method is applied to analyze an ozone data set.
The Origin of Complex Behavior of Linearly Polarized Components in Parsec-Scale Jets

Evidence that the magnetic fields of extragalactic jets have a significant fraction of their energy in a random component is briefly summarized, and a detailed model of evolving, jet polarization structures is constructed, based on this picture. The evolving magnetic field structure of an oblique shock complex that forms in a relativistic jet simulation is explored by using velocity data from the hydrodynamical simulation to advect an initially random magnetic field distribution. Radiative transfer calculations reveal that emission from a propagating region of magnetic field, ‘ordered’ by the shock, and lying approximately transverse to the flow direction, merges with that from an evolving sheared region at the flow periphery. If such a flow were barely resolved, observation would suggest evolution from a somewhat oblique, to a more longitudinal, magnetic field structure with respect to the flow axis, while higher resolution observations would infer a component following a non-linear trajectory, and with a magnetic field orientation that rotates during evolution. This result highlights the ambiguity in interpreting VLBP data, and illustrates the importance of simulations in providing a framework for proper interpretation of such data. Subject headings: galaxies: jets — hydrodynamics — magnetic fields — polarization — radiative transfer — relativity — shock waves
Design, synthesis, and analysis of conformationally constrained nucleic acids

In this review I discuss straightforward and general methods to modify nucleic acid structure with disulfide cross-links. A motivating factor in developing this chemistry was the notion that disulfide bonds would be excellent tools to probe the structure, dynamics, thermodynamics, folding, and function of DNA and RNA, much in the way that cystine cross-links have been used to study proteins. The chemistry described has been used to synthesize disulfide cross-linked hairpins and duplexes, higher order structures like triplexes, nonground-state conformations, and tRNAs. Since the cross-links form quantitatively by mild air oxidation and do not perturb either secondary or tertiary structure, this modification should prove quite useful for the study of nucleic acids. © 1998 John Wiley & Sons, Inc. Biopoly 48: 83-96, 1998
A High-Frequency Resonant Inverter Topology With Low-Voltage Stress

This paper presents a new switched-mode resonant inverter, which we term the inverter, that is well suited to operation at very high frequencies and to rapid on/off control. Features of this inverter topology include low semiconductor voltage stress, small passive energy storage requirements, fast dynamic response, and good design flexibility. The structure and operation of the proposed topology are described, and a design procedure is introduced. Experimental results demonstrating the new topology are also presented. A prototype inverter is described that switches at 30 MHz and provides over 500 W of radio frequency power at a drain efficiency above 92%. It is expected that the inverter will find use as a building block in high-performance dc-dc converters among other applications.
Cluster--cluster strong lensing: expectations and detection methods

ABSTRACT We calculate the all-sky number of galaxy clusters that are expected to be gravita-tionally lensed by foreground massive clusters. We describe the redshift and numberdistributions of clusters using a Press-Schechter analysis, and model the foregroundlensing clusters as singular isothermal spheres. If Ω m = 0.3 and Ω Λ = 0.7, we ex-pect ∼ 30 cluster-cluster strong lensing events that involve foreground X-ray lumi-nous clusters with total mass greater than 7.5 × 10 14 h −1 M⊙, or X-ray luminosityL x (2 − 10keV) ∼> 8 × 10 44 h −2 ergss −1 , and background clusters with total massgreater than 10 14 h −1 M⊙. The number expected in an open universe with Ω m = 0.3is less than ∼ 4. Because of uncertainty in σ 8 , the root-mean-square density ﬂuc-tuations in spheres of radius 8h −1 Mpc, the exact number of such lensing events isuncertain by a factor of about 5. We examine methods to detect cluster-cluster lensingevents based on optical, X-ray, and Sunyaev-Zel’dovich eﬀect observations.Key words: cosmology: observations — gravitational lensing — galaxies: clusters —galaxies: clusters: individual: Cl0024+17
MAP estimation of semi-metric MRFs via hierarchical graph cuts

We consider the task of obtaining the maximum a posteriori estimate of discrete pairwise random fields with arbitrary unary potentials and semi-metric pairwise potentials. For this problem, we propose an accurate hierarchical move making strategy where each move is computed efficiently by solving an st-MINCUT problem. Unlike previous move making approaches, e.g. the widely used α-expansion algorithm, our method obtains the guarantees of the standard linear programming (LP) relaxation for the important special case of metric labeling. Unlike the existing LP relaxation solvers, e.g. interior-point algorithms or tree-reweighted message passing, our method is significantly faster as it uses only the efficient st-MINCUT algorithm in its design. Using both synthetic and real data experiments, we show that our technique outperforms several commonly used algorithms.
Smooth muscle cell polymeric transfection is an efficient alternative to traditional methods of experimental gene therapy

Abstract Background Gene therapy shows promise in the treatment of vascular disease. However, traditional transfection methods commonly used in the laboratory are poorly translatable to in vivo conditions, primarily due to the immune response to viral vectors, the cellular toxicity of chemical transfection, and the technical impracticality of electroporation. Biodegradable polymers have shown promise as a safe, predictable, and nontoxic alternative, relying on endocytosis of synthetic polymeric carriers, which are bioconjugated to the targeted genetic material of choice. However, to date most of the feasibility studies have been exclusively performed in stem cells. Differentiated cell types would be prime targets for therapeutic gene modulation in the prevention of various disease processes. We aim to establish polymeric transfection as a method for gene therapy in cells of vascular origin. Here we compared the efficiency of polymeric transfection with chemical transfection agents routinely used in a laboratory setting in vascular smooth muscle cells. Methods Human aortic smooth muscle cells (HASMC) were transfected with fluorescently labeled GAPDH siRNA or negative control (NC) siRNA. Transfection methods included poly(B-amino ester) polymer (StemFECT) bioconjugates, DharmaFECT2 complexes, and Santa Cruz complexes. Conjugate endocytosis was confirmed by fluorescent microscopy, and GAPDH gene silencing was assayed by qPCR normalized to 18S. Results Santa Cruz reagent complexes were the least efficient, with the maximum achievable gene silencing using a 9 μL reagent : 70 pmol siRNA/mL complex (59% ± 6%; n = 3). Maximum GADPH gene silencing using DharmaFECT2 was achieved with a 1.5 μL reagent : 100 pmol siRNA/mL complex (19% ± 1% expression versus NC; n = 4). Equivalent silencing was achieved using a comparable StemFECT bioconjugate of 1.3 μL polymer : 100 pmol siRNA/mL (25% ± 3% expression versus NC; n = 4; P = NS versus DharmaFECT2). By increasing the StemFECT bioconjugate to 1.95 μL polymer : 100 pmol siRNA/mL, gene silencing was significantly increased (10% ± 1% expression versus NC; n = 6; P Conclusion HASMCs were efficiently transfected using polymeric bioconjugates in a manner comparable to and exceeding other transfection agents routinely used in vitro. This proof of concept establishes polymeric transfection as a viable method for in vitro investigation of differentiated vascular cells. Future studies will expand on this method of gene therapy for ex vivo transfection of whole vessel segments and in vivo transfection in animal models of vascular disease. Our long-term goal is to deliver molecular inhibitors of genes thought to play a role in intimal hyperplasia, restenosis, and vessel graft failure.
The Equilibrium Allele Frequency Distribution for a Population with Reproductive Skew

We study the population genetics of two neutral alleles under reversible mutation in a model that features a skewed offspring distribution, called the Λ-Fleming–Viot process. We describe the shape of the equilibrium allele frequency distribution as a function of the model parameters. We show that the mutation rates can be uniquely identified from this equilibrium distribution, but the form of the offspring distribution cannot itself always be so identified. We introduce an estimator for the mutation rate that is consistent, independent of the form of reproductive skew. We also introduce a two-allele infinite-sites version of the Λ-Fleming–Viot process, and we use it to study how reproductive skew influences standing genetic diversity in a population. We derive asymptotic formulas for the expected number of segregating sites as a function of sample size and offspring distribution. We find that the Wright–Fisher model minimizes the equilibrium genetic diversity, for a given mutation rate and variance effective population size, compared to all other Λ-processes.
A boundary stress tensor for higher-derivative gravity in AdS and Lifshitz backgrounds

We investigate the Brown-York stress tensor for curvature-squared theories. This requires a generalized Gibbons-Hawking term in order to establish a well-posed variational principle, which is achieved in a universal way by reducing the number of derivatives through the introduction of an auxiliary tensor field. We examine the boundary stress tensor thus defined for the special case of ‘massive gravity’ in three dimensions, which augments the Einstein-Hilbert term by a particular curvature-squared term. It is shown that one obtains finite results for physical parameters on AdS upon adding a ‘boundary cosmological constant’ as a counterterm, which vanishes at the so-called chiral point. We derive known and new results, like the value of the central charges or the mass of black hole solutions, thereby confirming our prescription for the computation of the stress tensor. Finally, we inspect recently constructed Lifshitz vacua and a new black hole solution that is asymptotically Lifshitz, and we propose a novel and covariant counterterm for this case.
Social Pressure and Voter Turnout: Evidence from a Large-Scale Field Experiment

Voter turnout theories based on rational self-interested behavior generally fail to predict significant turnout unless they account for the utility that citizens receive from performing their civic duty. We distinguish between two aspects of this type of utility, intrinsic satisfaction from behaving in accordance with a norm and extrinsic incentives to comply, and test the effects of priming intrinsic motives and applying varying degrees of extrinsic pressure. A large-scale field experiment involving several hundred thousand registered voters used a series of mailings to gauge these effects. Substantially higher turnout was observed among those who received mailings promising to publicize their turnout to their household or their neighbors. These findings demonstrate the profound importance of social pressure as an inducement to political participation.
A new coplanar-grid high-pressure xenon gamma-ray spectrometer

High-pressure xenon (HPXe) gas is a desirable radiation detection medium for many reasons, including its large atomic number, high density, low mean energy to produce an electron-ion pair, and the ability to produce devices with large detection volumes. While past work in HPXe has produced relatively successful detectors with energy resolution at 662 keV as good as approximately 2% FWHM, an expected limitation of these chambers in field operation is resolution degradation due to the vibration of their Frisch grids. Progress on a detector without a Frisch grid is reported in this submission; it is expected that the proposed anode design will provide competitive energy resolution with minimal degradation from mechanical vibration. Simulations accounting for charge carrier statistics, changes in the charge induced on the anode as a function of interaction location, and electronic noise predict a best-case energy resolution of 2.3% FWHM at 662 keV. Experimental data is compared with these simulations
Rapid Room Temperature Buchwald–Hartwig and Suzuki–Miyaura Couplings of Heteroaromatic Compounds Employing Low Catalyst Loadings

The use of second-generation [(NHC)Pd(R-allyl)Cl] complexes for Suzuki-Miyaura and Buchwald-Hartwig cross-coupling reactions involving heteroaromatic halides at room temperature is reported. The first examples of room temperature Suzuki-Miyaura cross-coupling of deactivated aryl chlorides with alkenyl boronic acids are also disclosed. Terminal substitution at the allyl moiety of the palladium complex facilitates its activation at room temperature leading to very active catalytic species enabling the present catalytic transformations to be performed rapidly using very mild reaction conditions. Catalyst loadings can be as low as 10 ppm for the Buchwald-Hartwig aryl amination and 50 ppm for the Suzuki-Miyaura reaction.