cssi/SciSciGPT-SciSciNet huggingface dataset:
Ancient Light from Young Cosmic Cities: Physical and Observational Signatures of Galaxy Proto-clusters

A growing number of galaxy clusters at z = 1-2 is being discovered as part of deep optical, IR, X-ray, and Sunyaev-Zel'dovich effect surveys. For a complete picture of cluster formation, however, it is important that we also start probing the much earlier epoch, between redshifts of about 2 and 7, during which these clusters and their galaxies first began to form. Because the study of these so-called proto-clusters is currently quite limited by small number statistics, widely varying selection techniques, and many assumptions, we have performed a large systematic study of cluster formation utilizing cosmological simulations. We use the Millennium Simulations to track the evolution of dark matter and galaxies in about 3000 clusters from the earliest times to z = 0. We define an effective radius Re for proto-clusters and characterize their growth in size and mass with cosmic time. We show that the progenitor regions of galaxy clusters (ranging in mass from ~1014 to a few times 1015 M ?) can already be identified in galaxy surveys at very early times (at least up to z ~ 5), provided that the galaxy overdensities are measured on a sufficiently large scale (Re ~ 5-10?Mpc comoving) and with sufficient statistics. We present the overdensities in matter, dark matter halos, and galaxies as functions of present-day cluster mass, redshift, bias, and window size that can be used to interpret the wide range of structures found in real surveys. We also derive the probability that a structure having a galaxy overdensity ?gal, defined by a set of observational selection criteria, is indeed a proto-cluster, and we show how their z = 0 masses can already be estimated long before virialization. We present overdensity profiles as a function of radius, and we further show how the projected surface overdensities of proto-clusters decrease as the uncertainties in redshift measurements increase. We provide a table of proto-cluster candidates selected from the literature and discuss their properties in light of our simulation predictions. This paper provides the general framework that will allow us to extend the study of cluster formation out to much higher redshifts using the large number of proto-clusters that are expected to be discovered in, e.g., the upcoming HETDEX and Hyper Suprime-Cam surveys.
Optical biopsy with long-range nondiffracting beams

Most current configurations for optical biopsy contain fiber optic bundles at both the delivery and receiving ends of the optical system. Some layouts include distal lenses to either collimate or focus the incident light at various depth locations across the tissue. The inherent beam divergence, along with the highly scattering nature of the living tissue, are known to limit the penetration depth of the probe and the spatial or temporal resolution of the detected signal. In this work we study a novel modality for tissue illumination based on the use of long-range nondiffracting beams (LRNB). LRNB represent narrow-width light pencils with a constant or linearly varying axial intensity that propagate over large distances without diffractive spreading. Recent tests have demonstrated that LRNB exhibit in significant intensity distortions when operated as beacon beams through atmospheric turbulence. Our numerical and software simulations show that LRNB may offer the potential for larger penetration depth and enhanced contrast over setups using conventional laser beams. Clinical applications include diagnosis, laser surgery and photodynamic therapy.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Genome-scale reconstruction of the metabolic network in Yersinia pestis, strain 91001

The gram-negative bacterium Yersinia pestis, the aetiological agent of bubonic plague, is one of the deadliest pathogens known to man. Despite its historical reputation, plague is a modern disease which annually afflicts thousands of people. Public safety considerations greatly limit clinical experimentation on this organism and thus development of theoretical tools to analyze the capabilities of this pathogen is of utmost importance. Here, we report the first genome-scale metabolic model of Yersinia pestis biovar Mediaevalis based both on its recently annotated genome, and physiological and biochemical data from the literature. Our model demonstrates excellent agreement with Y. pestis' known metabolic needs and capabilities. Since Y. pestis is a meiotrophic organism, we have developed CryptFind, a systematic approach to identify all candidate cryptic genes responsible for known and theoretical meiotrophic phenomena. In addition to uncovering every known cryptic gene for Y. pestis, our analysis of the rhamnose fermentation pathway suggests that betB is the responsible cryptic gene. Despite all of our medical advances, we still do not have a vaccine for bubonic plague. Recent discoveries of antibiotic resistant strains of Yersinia pestis coupled with the threat of plague being used as a bioterrorism weapon compel us to develop new tools for studying the physiology of this deadly pathogen. Using our theoretical model, we can study the cell's phenotypic behavior under different circumstances and identify metabolic weaknesses that may be harnessed for the development of therapeutics. Additionally, the automatic identification of cryptic genes expands the usage of genomic data for pharmaceutical purposes.
Diffractive effects in singly resonant continuous-wave parametric oscillators

/kP=0.33and0.50. It is found that the ratio of pump depletion to maximal depletion as a function of the ratio of pump power to threshold power agrees with the plane-wave prediction to within 5%, for a wide range of focusing conditions. The observed trends are explained as resulting from intensity- and phase-dependent mechanisms.
REIT Momentum and Characteristic-Related REIT Returns

Recent evidence confirms that in factor-model examinations of the cross-section of REIT returns, REIT momentum emerges as the dominant driver. Acknowledging the importance of momentum, the current study explores whether and how REIT return patterns are linked to the underlying characteristics of the REITs themselves, in the manner of Daniel and Titman’s (Journal of Finance 52(1):1–33, 1997, Journal of Portfolio Management 24(4):24–33, 1998) characteristics model. Over the period 1993 through 2009, we find that after controlling for momentum, book-to-market, institutional ownership, and illiquidity are all strongly associated with REIT returns while size and analyst coverage are not. We further extend prior research by examining the influence of changes in interest rate cycles on REIT returns, and find that the characteristic-return relationships are heavily influenced by interest rates.
Optimal choice of monetary policy instruments in a macroeconometric model

Abstract This paper uses stochastic simulation and my U.S. econometric model to examine the optimal choice of monetary policy instruments. Are the variances, covariances, and parameters in the model such as to favor one instrument over the other, in particular the interest rate over the money supply? The results for the regular version of the model provide support for what seems to be the Fed's current choice of using the interest rate as its primary instrument. On the other hand, the results support the use of the money supply as the primary instrument if there are rational expectations in the bond market.
Using spectral estimation techniques in adaptive processing antenna systems

Improved spectral estimation techniques hold promise for becoming a valuable asset in adaptive processing array antenna systems. Their value lies in the considerable amount of additional useful information which they can provide about the interference environment, utilizing a relatively small number of degrees of freedom (DOF). The "superresolution" capabilities, estimation of coherence, and relative power level determination serve to complement and refine the data from faster conventional estimation techniques. Two conceptual application area examples for using such techniques are discussed; partially adaptive low-sidelobe arrays, and fully adaptive tracking arrays. For the partially adaptive area the information is utilized for efficient assignment of a limited number of DOF in a beamspace constrained adaptive system in order to obtain a stable main beam, retention of low sidelobes, considerably faster response, and reduction in overall cost. These benefits are demonstrated via simulation examples computed for a 16-element linear array. For the fully adaptive tracking array area the information is utilized in an all-digital processing system concept to permit stable hulling of coherent interference sources in the main beam region, efficient assignment/control of the available DOF, and greater flexibility in time-domain adaptive filtering strategy.
Technology and Development: Universalizing Access to and Protection of Information and Communication Technology

As many features of modern digital information and online communications are transcending and transforming the traditional modes of interaction and identity, so is transformed the need for addressing these new features in ways that conform to pertinent realities. A great deal of human events and experiences are likely to occur in ways different from those seen in the pre-digital era. Having witnessed a number of such events and experiences, the next stage is action and understanding. As the potential for change and development, associated with information and communication technology (ICT), is getting fame, its use is bearing fruits, and global internet population constantly increased, so is the demand for enabling equal, wider access, and protection. This article is thus concerned with two fundamental questions: how to universalize access to ICT, and how to protect it from abuse, censorship and restriction. These questions are predominantly explored from the lenses of international law.
Transistor-Driven Beam Switching Tube Decade Counter

This paper describes an electrical readout decade counter employing the magnetron beam switching tube with transistor drive. Double-pulse resolution is 1 ?sec. The unit will accept a variety of transistor types, and will tolerate supply voltage variations of ±20 per cent at ambient temperatures up to 60°C. A "Pixie" neon indicator is driven without the use of additional transistors. A readout circuit for printer or punched paper tape is presented.
A subdivision algorithm in configuration space for findpath with rotation

A recursive cellular representation for configuration space is presented along with an algorithm for searching that space for collision-free paths. The details of the algorithm are presented for polygonal obstacles and a moving object with two translational and one rotational degrees of freedom.
Organic synthesis via magnetic attraction: benign and sustainable protocols using magnetic nanoferrites

Magnetic nano-catalysts have been prepared using simple modification of iron ferrites. The nm size range of these particles facilitates the catalysis process, as an increased surface area is available for the reaction; the easy separation of the catalysts by an external magnet and their recovery and reuse are additional beneficial attributes. Glutathione bearing nano-ferrites have been used as organocatalysts for the Paal–Knorr reaction and homocoupling of boronic acids. Nanoferrites, post-synthetically modified by ligands, were used to immobilize nanometals (Cu, Pd, Ru, etc.) which enabled the development of efficient, sustainable and green procedures for azide–alkynes-cycloaddition (AAC) reactions, C–S coupling, O-allylation of phenol, Heck-type reactions and hydration of nitriles.
An optimal stopping approach to the conservation of biodiversity

In the past two decades, a considerable amount of concern has been expressed in academic and nonacademic circles about the decline in the world's diverse biological resources. Recently, Swanson (in: Biodiversity Loss: Economic and Ecological Issues. Cambridge University Press, Cambridge, 1995) has suggested that the problem of biodiversity loss is really a problem of regulating the natural habitat conversion process in which naturally existing species have systematically been replaced by human chosen ones. In this way of looking at the problem, a decision maker's central task is to determine the optimal point at which this conversion process should be halted. In this paper, I show how the theory of optimal stopping can be applied to model the biodiversity loss problem as described above. Specifically, I pose the underlying conservation question within the framework of a Markov decision process. I then show how to determine the optimal point at which this conversion process should be halted.
CMOL: Second life for silicon?

This is a brief review of the recent work on the prospective hybrid CMOS/nanowire/nanodevice (''CMOL'') circuits including digital memories, reconfigurable Boolean-logic circuits, and mixed-signal neuromorphic networks. The basic idea of CMOL circuits is to combine the advantages of CMOS technology (including its flexibility and high fabrication yield) with the extremely high potential density of molecular-scale two-terminal nanodevices. Relatively large critical dimensions of CMOS components and the ''bottom-up'' approach to nanodevice fabrication may keep CMOL fabrication costs at affordable level. At the same time, the density of active devices in CMOL circuits may be as high as 10^1^2cm^2 and that they may provide an unparalleled information processing performance, up to 10^2^0 operations per cm^2 per second, at manageable power consumption.
Thioglycosides protected as trans-2,3-cyclic carbonates in chemoselective glycosylations.

Thioglycosides protected as trans-2,3-cyclic carbonates have significantly lower anomeric reactivities than fully acylated and N-acyl-protected thioglycosides and can be used as acceptors in chemoselective glycosylations with a wide range of thioglycosyl donors. The resulting thioglycosides can be further activated to give 1,2-cis-linked glycosides.
Corporate Interests: How the News Media Portray the Economy

This study examines contradictory claims about the news media's coverage of the economy. After discussing various sociological perspectives on news media, I compare the objective performance of California's economy, as measured by statistical indicators, to accounts of the economy found in the state's largest newspaper—the Los Angeles Times. The data reveal that, despite growth patterns that overwhelmingly favored economic elites, the negative news about the economy disproportionately depicted events and problems affecting corporations and investors instead of the general workforce. When the Times did discuss problems affecting workers, the articles were relatively short, most often placed in the back sections of the newspaper, and rarely discussed policy alternatives to the status quo. Moreover, unlike the viewpoints of business leaders and government officials, the viewpoints of workers or their spokespersons were rarely used as sources of information. These findings provide qualified support for existing scholarship purporting that the news media, when reporting on the economy, privilege the interests of corporations and investors over the interests of the general workforce.
Lexicographic Products and the Power of Non-linear Network Coding

We introduce a technique for establishing and amplifying gaps between parameters of network coding and index coding problems. The technique uses linear programs to establish separations between combinatorial and coding-theoretic parameters and applies hyper graph lexicographic products to amplify these separations. This entails combining the dual solutions of the lexicographic multiplicands and proving that this is a valid dual solution of the product. Our result is general enough to apply to a large family of linear programs. This blend of linear programs and lexicographic products gives a recipe for constructing hard instances in which the gap between combinatorial or coding-theoretic parameters is polynomially large. We find polynomial gaps in cases in which the largest previously known gaps were only small constant factors or entirely unknown. Most notably, we show a polynomial separation between linear and non-linear network coding rates. This involves exploiting a connection between matroids and index coding to establish a previously unknown separation between linear and non-linear index coding rates. We also construct index coding problems with a polynomial gap between the broadcast rate and the trivial lower bound for which no gap was previously known.
Austrian theories of entrepreneurship: Insights from complexity theory

This paper examines various Austrian theories of entrepreneurship through the lens of complexity theory, more specifically via the concept of a dancing fitness landscape. Problems in many fields (including economics) can be characterized as attempting to find the highest peak on a fitness landscape (which corresponds to an efficient or optimal resource allocation). A rugged fitness landscape is one characterized by many peaks and troughs, while a dancing fitness landscape is one where the peaks and troughs change over time due either to exogenous or endogenous activity. I argue that several key disagreements among Austrian economists can be better understood through the metaphor of a fitness landscape. The implications of this insight for various branches of Austrian economics are also considered. This study is timely as radical Austrian views are starting to percolate into business schools leading to increased debate among management scholars about the precise nature of the entrepreneurial process (Chiles et al. 2007; Sarasvathy and Dew 2008; Alvarez et al. 2010).
Vacuum Electrodynamics of Accelerated Systems: Nonlocal Maxwell's Equations

The nonlocal electrodynamics of accelerated systems is discussed in connection with the development of Lorentz-invariant nonlocal field equations. Nonlocal Maxwell’s equations are presented explicitly for certain linearly accelerated systems. In general, the field equations remain nonlocal even after accelerated motion has ceased.
Dynamics of a vortex in a trapped Bose-Einstein condensate

We consider a large condensate in a rotating anisotropic harmonic trap. Using the method of matched asymptotic expansions, we derive the velocity of an element of vortex line as a function of the local gradient of the trap potential, the line curvature and the angular velocity of the trap rotation. This velocity yields small-amplitude normal modes of the vortex for 2D and 3D condensates. For an axisymmetric trap, the motion of the vortex line is a superposition of plane-polarized standing-wave modes. In a 2D condensate, the planar normal modes are degenerate, and their superposition can result in helical traveling waves, which differs from a 3D condensate. Including the effects of trap rotation allows us to find the angular velocity that makes the vortex locally stable. For a cigar-shape condensate, the vortex curvature makes a significant contribution to the frequency of the lowest unstable normal mode; furthermore, additional modes with negative frequencies appear. As a result, it is considerably more difficult to stabilize a central vortex in a cigar-shape condensate than in a disc-shape one. Normal modes with imaginary frequencies can occur for a nonaxisymmetric condensate (in both 2D and 3D). In connection with recent JILA experiments, we consider the motion of a straight vortex line in a slightly nonspherical condensate. The vortex line changes its orientation in space at the rate proportional to the degree of trap anisotropy and can exhibit periodic recurrences.
Localized gravity and large hierarchy from string theory

Abstract Within a D-dimensional superstring spacetime, we construct a non-supersymmetric brane-world with localized gravity and large hierarchy between the scale in the bulk, MD, and the scale on the brane, MD−2. The localization of gravity and the large hierarchy are both guaranteed by the presence of nontrivial stringy moduli, such as the axion–dilaton system for the type IIB string theory.
Beyond the t dwarfs: theoretical spectra, colors, and detectability of the coolest brown dwarfs

We explore the spectral and atmospheric properties of brown dwarfs cooler than the latest known T dwarfs. Our focus is on the yet-to-be-discovered free-floating brown dwarfs in the Teff range from ~800 to ~130 K and with masses from 25 to 1 MJ. This study is in anticipation of the new characterization capabilities enabled by the launch of the Space Infrared Telescope Facility (SIRTF) and the eventual launch of the James Webb Space Telescope (JWST). In addition, it is in support of the continuing ground-based searches for the coolest substellar objects. We provide spectra from ~0.4 to 30 μm, highlight the evolution and mass dependence of the dominant H2O, CH4, and NH3 molecular bands, consider the formation and effects of water ice clouds, and compare our theoretical flux densities with the putative sensitivities of the instruments on board SIRTF and JWST. The latter can be used to determine the detection ranges from space of cool brown dwarfs. In the process, we determine the reversal point of the blueward trend in the near-infrared colors with decreasing Teff (a prominent feature of the hotter T dwarf family), the Teff's at which water and ammonia clouds appear, the strengths of gas-phase ammonia and methane bands, the masses and ages of the objects for which the neutral alkali metal lines (signatures of L and T dwarfs) are muted, and the increasing role as Teff decreases of the mid-infrared fluxes longward of 4 μm. These changes suggest physical reasons to expect the emergence of at least one new stellar class beyond the T dwarfs. Furthermore, studies in the mid-infrared could assume a new, perhaps transformational, importance in the understanding of the coolest brown dwarfs. Our spectral models populate, with cooler brown dwarfs having progressively more planet-like features, the theoretical gap between the known T dwarfs and the known giant planets. Such objects likely inhabit the Galaxy, but their numbers are as yet unknown.
Synthesis and characterization of AU2Se6 (A = K, Cs).

Two new ternary uranium selenides, AU 2 Se 6 (A = K, Cs), were prepared using the reactive flux method. Single crystal X-ray diffraction was performed on single crystals. The compounds crystallize in the orthorhombic Immm space group, Z = 2. CsU 2 Se 6 has cell parameters of a = 4.046(2) A, b = 5.559(3) A, and c = 24.237(12) A. KU 2 Se 6 has cell parameters of a = 4.058(3) A, b = 5.556(4) A, and c = 21.710(17) A. The compounds are isostructural to the previously reported KTh 2 Se 6 . The two-dimensional layered structure is related to ZrSe 3 with the alkali metals residing in the interlayer space. The oxidation states of uranium and selenium were evaluated using X-ray photoelectron spectroscopy (XPS). Uranium was found to be tetravalent, while selenium was found to be in two oxidation states, one of which is -2. The other oxidation state is similar to that found in a polyselenide network. While this structure is known, our work examines how the structure changes through the transactinide series.
Enzymatic hydrolysis of organic phosphorus in river bed sediments

Abstract Enzymatic hydrolysis of phosphorus (P) in bed sediments is an important process that maintains bioavailable P in the river systems. The P bioavailability is the criterion for assessing the eutrophication potential in rivers and streams. The objective of this research was to determine potential bioavailability of organic P (OP) in the Bronx River bed sediments using native phosphatases (NPase) and phosphodiesterase (PDEase) hydrolysis. The bed sediments collected in summer 2006 and 2007 were incubated at 37 °C for 6 h at pH 7.5 with NPase. The results showed that NPase hydrolyzed a substantial amount of OP (up to 76%) under favorable temperature and pH, indicating OP could be hydrolyzed under increased temperature, and in turn increase in P availability in the river. Similarly, the resulting form sediments incubated with PDEase at 37 °C and pH 8.8 showed that up to 82% of OP could be hydrolyzed. Strong correlations between percentage of OP hydrolyzed by PDEase and organic matter (OM) were observed for sediments collected in 2006 (r = 0.745; p ≤ 0.01) and 2007 (r = 0.724; p ≤ 0.01), indicating PDEase hydrolysable P is mainly associated with OM. It is indicative that local hydro-climatic changes such as temperature increase and pH variations could hydrolyze a substantial amount of OP and increase bioavailable P in the water column, resulting in a potential threat to the river ecosystems.
Fuel Character Effects on the TF41 Engine Combustion System

The effects of fuel property variations on the performance and exhaust emissions of the Allison TF41 engine combustion system were determined by combustor rig tests and data analysis. Hot section durability characteristics were evaluated through computer simulations. Twelve refined and blended fuels which incorporated variations in hydrogen content, aromatic type and content, distillation range, and viscosity were evaluated. At high-power operating conditions, fuel properties such as hydrogen and aromatic content affected emission levels, smoke formation, combustion efficiency, and linear wall temperatures. No significant correlation between combustor performance parameters and fuel properties could be found at idle conditions. The maximum attainable ignition altitude was severely limited by reduced fuel hydrogen content (increased aromatic content). Combustor barrel (dome to discharge nozzle) metal temperatures responded to changes in fuel hydrogen content and aromatic type. However, combustor life was not sensitive to fuel properties since the life-limiting discharge nozzle wall temperatures were relatively insensitive to any fuel tested. Turbine (stator vane and rotor blade) life showed very little correlation to any fuel property characteristic.
Realignment of objectives in information system degree programs

Development of degree programs in information system analysis and designed lagged demand by nearly five years. Now the growth of these programs appears to be outdistancing demand.
Barkhausen noise, subloops, demagnetization curves and universal scaling tuning disorder, field sweep rate, and history

In previous work [1], which we recently reviewed in [2,3,4], we discovered a critical point in the behavior of hysteretic systems. Adding disorder to the system, we found a second order transition from hysteresis loops with a macroscopic jump or burst (roughly as seen in the supercooling of liquids) to smoothly varying hysteresis loops (as seen in most magnets). We have studied the critical point in the nonequilibrium zero temperature random field Ising model (RFIM) (which is a simple model for magnets, that has aplications far beyond magnetic hysteresis and associated Barkhausen Noise), using mean field theory, renormalization group techniques, and numerical simulations in 2,3,4, and 5 dimensions. In a large region near the critical disorder the model exhibits power law distributions of noise (avalanches), universal behavior, and a diverging length scale [5,6,7].
Hybrid codes needed for coordination over the point-to-point channel

We consider a new fundamental question regarding the point-to-point memoryless channel. The source-channel separation theorem indicates that random codebook construction for lossy source compression and channel coding can be independently constructed and paired to achieve optimal performance for coordinating a source sequence with a reconstruction sequence. But what if we want the channel input to also be coordinated with the source and reconstruction? Such situations arise in network communication problems, where the correlation inherent in the information sources can be used to correlate channel inputs. Hybrid codes have been shown to be useful in a number of network communication problems. In this work we highlight their advantages over purely digital codebook construction by applying them to the point-to-point setting, coordinating both the channel input and the reconstruction with the source.1
The Shilov Boundary of an Operator Space and the Characterization Theorems

Abstract We study operator spaces, operator algebras, and operator modules from the point of view of the noncommutative Shilov boundary. In this attempt to utilize some noncommutative Choquet theory, we find that Hilbert C *-modules and their properties, which we studied earlier in the operator space framework, replace certain topological tools. We introduce certain multiplier operator algebras and C *-algebras of an operator space, which generalize the algebras of adjointable operators on a C *-module and the imprimitivity C *-algebra. It also generalizes a classical Banach space notion. This multiplier algebra plays a key role here. As applications of this perspective, we unify and strengthen several theorems characterizing operator algebras and modules. We also include some general notes on the commutative case of some of the topics we discuss, coming in part from joint work with Christian Le Merdy, about function modules.
Reconstruction of Random Colourings

Reconstruction problems have been studied in a number of contexts including biology, information theory and statistical physics. We consider the reconstruction problem for random k-colourings on the Δ-ary tree for large k. Bhatnagar et al. [2] showed non-reconstruction when $${\Delta \leq \frac12 k\log k - o(k\log k)}$$ . We tighten this result and show non-reconstruction when $${\Delta \leq k[\log k + \log \log k + 1 - \log 2 -o(1)]}$$ , which is very close to the best known bound establishing reconstruction which is $${\Delta \geq k[\log k + \log \log k + 1+o(1)]}$$ .
Cross-country evidence on the relationship between central banks and governments

Abstract The influence of government pressure on central bank behavior is examined for Canada, France, the U.K., and West Germany. With the budget deficit proxying for this pressure, there is evidence of an overall expansionary effect of the deficit on monetary policy response to stabilization objectives. Despite there otherwise being little consistency in the reaction functions estimated across the four countries, the marked tendency is for policy to become more accommodative at higher levels of the deficit. Hence, the results point to a potentially important regularity in the relationship between central banks and governments.
A quantum-chemical perspective into low optical-gap polymers for highly-efficient organic solar cells

The recent and rapid enhancement in power conversion efficiencies of organic-based, bulk-heterojunction solar cells has been a consequence of both improved materials design and better understanding of the underlying physical processes involved in photocurrent generation. In this Perspective, we first present an overview of the application of quantum-chemical techniques to study the intrinsic material properties and molecular- and nano-scale processes involved in device operation. In the second part, these quantum-chemical tools are applied to an oligomer-based study on a collection of donor–acceptor copolymers that have been used in the highest-efficiency solar cell devices reported to date. The quantum-chemical results are found to be in good agreement with the empirical data related to the electronic and optical properties. In particular, they provide insight into the natures of the electronic excitations responsible for the near-infrared/visible absorption profiles, as well as into the energetics of the low-lying singlet and triplet states. These results lead to a better understanding of the inherent differences among the materials, and highlight the usefulness of quantum chemistry as an instrument for material design. Importantly, the results also point to the need to continue the development of integrated, multiscale modeling approaches to provide a thorough understanding of the materials properties.
Overview of imaging science.

Abstract The traditional disciplines of science are grounded in the observation and measurement of object properties. Recent advances in digital computer technology have spawned numerous computer-based imaging systems that extend the range of observation and measurement into realms that would otherwise be inaccessible. More importantly, the same set of principles, concepts, strategies, and methods may be used to address the generic issues involved in the production and use of all digitized images. Recognition of this fact is giving rise to the new discipline of imaging science, with its own intellectual agenda.
An efficient distributed algorithm for constructing small dominating sets

The dominating set problem asks for a small subset D of nodes in a graph such that every node is either in D or adjacent to a node in D. This problem arises in a number of distributed network applications, where it is important to locate a small number of centers in the network such that every node is nearby at least one center. Finding a dominating set of minimum size is NP-complete, and the best known approximation is logarithmic in the maximum degree of the graph and is provided by the same simple greedy approach that gives the well-known logarithmic approximation result for the closely related set cover problem.We describe and analyze new randomized distributed algorithms for the dominating set problem that run in polylogarithmic time, independent of the diameter of the network, and that return a dominating set of size within a logarithmic factor from optimal, with high probability. In particular, our best algorithm runs in O(log n log Δ) rounds with high probability, where n is the number of nodes, Δ is one plus the maximum degree of any node, and each round involves a constant number of message exchanges among any two neighbors; the size of the dominating set obtained is within O (log Δ) of the optimal in expectation and within O(log n) of the optimal with high probability. We also describe generalizations to the weighted case and the case of multiple covering requirements.
A sampling framework for incorporating quantitative mass spectrometry data in protein interaction analysis

Comprehensive protein-protein interaction (PPI) maps are a powerful resource for uncovering the molecular basis of genetic interactions and providing mechanistic insights. Over the past decade, high-throughput experimental techniques have been developed to generate PPI maps at proteome scale, first using yeast two-hybrid approaches and more recently via affinity purification combined with mass spectrometry (AP-MS). Unfortunately, data from both protocols are prone to both high false positive and false negative rates. To address these issues, many methods have been developed to post-process raw PPI data. However, with few exceptions, these methods only analyze binary experimental data (in which each potential interaction tested is deemed either observed or unobserved), neglecting quantitative information available from AP-MS such as spectral counts. We propose a novel method for incorporating quantitative information from AP-MS data into existing PPI inference methods that analyze binary interaction data. Our approach introduces a probabilistic framework that models the statistical noise inherent in observations of co-purifications. Using a sampling-based approach, we model the uncertainty of interactions with low spectral counts by generating an ensemble of possible alternative experimental outcomes. We then apply the existing method of choice to each alternative outcome and aggregate results over the ensemble. We validate our approach on three recent AP-MS data sets and demonstrate performance comparable to or better than state-of-the-art methods. Additionally, we provide an in-depth discussion comparing the theoretical bases of existing approaches and identify common aspects that may be key to their performance. Our sampling framework extends the existing body of work on PPI analysis using binary interaction data to apply to the richer quantitative data now commonly available through AP-MS assays. This framework is quite general, and many enhancements are likely possible. Fruitful future directions may include investigating more sophisticated schemes for converting spectral counts to probabilities and applying the framework to direct protein complex prediction methods.
Alternative intertemporal permit trading regimes with stochastic abatement costs

We examine the social efficiency of alternative intertemporal permit trading regimes. The role of uncertainty and information asymmetry is discussed. For banking to be welfare improving, uncertainty itself does not matter, while information asymmetry does. Three effects of banking are identified: externality effect, information effect, and total permit effect. In the absence of total permit effect, banking is welfare improving if information effect is positive and dominates the externality effect. The relative efficiency of banking regimes with different intertemporal trading ratios is affected by the slope of the benefit and damage functions and the covariance of the shocks.
Space Infrared Astronomy: Overview Of NASA Planning

The present status and potential future direction of the NASA space infrared astronomy program is reviewed. Projects and project concepts dis-cussed include the Infrared Astronomy Satellite, Small Infrared Telescope on Spacelab 2, Cosmic Background Explorer, Shuttle Infrared Telescope Facility, Space Telescope, large deployable reflector, molecular line survey, and infrared interferometer in space. Needs for continued engineering development in critical technology areas such as detectors, cryogenics, optics, and space structures are indicated.
Deformations of covers,Brill-Noether theory, and wild ramification

In this paper, we give a simple description of the deformations of a map between two smooth curves with partially prescribed branching, in the cases that both curves are fixed, and that the source is allowed to vary. Both descriptions work equally well in the tame or wild case. We then apply this result to obtain a positive-characteristic Brill-Noether-type result for ramified maps from general curves to the projective line, which even holds for wild ramification indices. Lastly, in the special case of rational functions on the projective line, we examine what we can say as a result about families of wildly ramified maps.
A new design for model reference robust control using state-space techniques

The authors propose a model reference control (MRC) structure that is different from existing MRC structures. The new approach that we discuss is based on state-space techniques; however, it is not simply an alternative form of the input-output transfer function approach. The method we use to achieve our result is obtained through a concept often called ‘filtered transformation’. The filtered transformation has the effect of transforming the plant into a ‘big’ system that is composed of two subsystems. One subsystem satisfies the standard matching condition, which is not enjoyed by the original plant, while all the unmatched and unmodelled dynamics are drawn into the other unmatched subsystem. The control objective for the original plant is transferred into the control of the matched subsystem while also ensuring that the unmatched subsystem remains uniformly bounded. A robust control approach and the backstepping method are used to guarantee that the overall states are globally uniformly bounded and that...
X-ray absorption branching ratio in actinides: LDA+DMFT approach

To investigate the X-ray absorption (XAS) branching ratio from the core 4d to valence 5f states, we set up a theoretical framework by using a combination of density functional theory in the Local Density Approximation and Dynamical Mean-Field Theory (LDA+DMFT), and apply it to several actinides. The results of the LDA+DMFT reduces to the band limit for itinerant systems and to the atomic limit for localized f electrons, meaning a spectrum of 5f itinerancy can be investigated. Our results provides a consistent and unified view of the XAS branching ratio for all elemental actinides, and is in good overall agreement with experiments.
Hypertension and kidney disease: A deadly connection

Kidney disease may be the cause or a consequence of hypertension. Hypertension affects 25% of the adult population in the United States. Similarly, chronic kidney disease (CKD) and end-stage renal disease (ESRD) have been steadily increasing in incidence because of the increasing age of the US population and rise in the incidence of risk factors, including hypertension. Substantial evidence supports the notion that elevated blood pressure is the most significant risk factor for developing CKD. Microalbuminuria has been shown to be the early marker of hypertensive renal disease. Furthermore, therapy to reduce microalbuminuria was associated with delayed progression of renal disease. Black Americans are at higher risk for developing hypertensive nephrosclerosis than whites. Hypertension is a major risk factor for cardiovascular events in patients with CKD and ESRD and those who have undergone renal transplantation. Studies have documented that elevated serum creatinine and CKD are risk factors for a cardiovascular event. Tight blood pressure control has been shown to reduce microalbuminuria and proteinuria and to delay progression of renal disease. Tailoring antihypertensive medication to the clinical setting to achieve a blood pressure goal is critical in reducing complications from this deadly connection.
Implications of reducing part use variability at an assembly plant

This paper compares the effectiveness of three strategies for reducing part use variability in an assembly plant: decreasing the total number of part options. building parts “to-order”, and reducing travel time variability. Each of these strategies can reduce the inventory needed to protect against running out of material at the plant. They allow inventory banks to be reduced, and reduce the likelihood of material stock-outs. A general model for evaluating the impact of the three strategies on inventory and transportation cost is developed. Interpreting this model resulted in the following conclusions: Reducing the total number of part options and building to-order are most effective at reducing part use variability when there are many options and when travel time is reliable. Shifting from common carrier to contract carrier is most effective when there are few options or when parts are built to-order. The effectiveness of building to-order and contract carriers is increased when the strategies are implem...
The future of Medicare policy reform

Abstract The Medicare program, the largest health insurance program in the United States, is clearly at a crossroads as it enters its third decade. Historical increases in health care expenditures, plus a changing political and economic landscape, have set the groundwork for policy reform. Two basic reform strategies—reimbursement arrangements and program funding mechanisms—are discussed. In 1983, Congress enacted to Medicare the Prospective Payment System (PPS) which initiated a fundamental change in the way hospitals are paid for care delivered to Medicare beneficiaries. But the PPS is only a stepping-stone to broader reforms such as capitation. In addition, new methods of program funding may be necessary, especially in light of policymakers' considerations of coverage of serices such as long-term care and organ transplants.
Protective effect of methylprednisolone on warm ischemia-reperfusion injury in a cholestatic rat liver

BACKGROUND: Cholestasis has been identified as a risk factor for oxidative stress, and it potentially enhances after ischemic-reperfusion injury. The aim of this study was to evaluate the role of methylprednisolone on warm ischemia-reperfusion injury in the presence of cholestasis. METHODS: A reversible cholestatic rat model was created. After 7 days, rats received 30 mg/kg of intravenous methylprednisolone 2 hours before ischemia, followed by 30 minutes of ischemia. Rats were euthanized 24 hours after ischemia. Serum aspartate aminotransferase and interleukin-6 were measured, and the liver was harvested for histology and myeloperoxidase estimation. RESULTS: Methylprednisolone had a protective effect, with a statistically significant decrease in aspartate aminotransferase (P .01) and a trend toward decreased levels of interleukin-6 (P .07). Histology showed a significant difference in architectural distortion (P .01), cytoplasmic vacuolation (P .01), and nodular hepatocellular necrosis (P .04). CONCLUSIONS: Methylprednisolone attenuated the ischemic-reperfusion injury in the presence of cholestasis and can be considered for clinical use in the presence of cholestasis. © 2010 Elsevier Inc. All rights reserved.
Flight graph based genetic algorithm for crew scheduling in airlines

Abstract Crew scheduling is an NP-hard constrained combinatorial optimization problem, very important for the airline industry [G. Yu (Ed.), Operations Research in Airline Industry, Kluwer Academic Publishers, Dordrecht, 1998]. We solve this problem using a genetic algorithm applied to a flight graph representation that represents several problem-specific constraints, unlike previous attempts [D. Levine, Application of a hybrid genetic algorithm to airline crew scheduling, Ph.D. dissertation, Computer Science Department, IIT , Chicago, USA, 1995; J.E. Beasley, P.C. Chu, A genetic algorithm for the set covering problem, Eur. J. Oper. Res. 94 (1996) 392–404; P.C. Chu, J.E. Beasley, A genetic algorithm for the set partitioning problem, Technical report, Imperial College, UK, 1995]. In extensive experimental comparisons on flight data of several airlines, the new approach performed better than other approaches in 17 out of 24 data sets.
Frontobasal approach for trauma and tumor

The potential for remediation of a host of varied disease processes afflicting the skull base has been increasingly realized over the past two decades. Advances in medical technology, the development of new approaches, and most importantly the close cooperation of the head and neck surgeon and the neurological surgeon have made this possible. Surgeons are attempting to diminish the injury to normal un-involved structures while at the same time maximizing exposure and enabling rectification of the disease or disorder. This is especially pertinent in a number of frontobasal approaches used in anterior craniofacial surgery. The osteoplastic flap approach to the posterior wall of the frontal sinus to repair small cerebrospinal fluid leaks and manage posterior wall fractures saves the patient a larger anterior craniotomy and brain retraction. Cranialization of the frontal sinus in comminuted through-and-through fractures allows for removal of devitalized brain, dural repair, and safe management of the frontal sinus. The lateral rhinotomy medial maxillectomy-ethmosphenoidectomy approach coupled with either an osteoplastic flap of the frontal sinus or a low limited craniotomy is an excellent approach for resection of tumors encroaching on the anterior skull base. Even malignancies of this region can be completely excised with adequate margins, yet produce minimal to no facial aesthetic distortion. Moreover, larger tumors requiring a more extensive lip-splitting incision and total maxillectomy with orbital exenteration can often anticipate minimal deformity, especially with good prosthetic rehabilitation. In the resection of aggressive malignancies, techniques of ocular preservation and facial bone sparing have been developed with encouraging cosmetic results.