cssi/SciSciGPT-SciSciNet huggingface dataset:
Highway mobility and vehicular ad-hoc networks in ns-3

The study of vehicular ad-hoc networks (VANETs) requires efficient and accurate simulation tools. As the mobility of vehicles and driver behavior can be affected by network messages, these tools must include a vehicle mobility model integrated with a quality network simulator. We present the first implementation of a well-known vehicle mobility model to ns-3, the next generation of the popular ns-2 networking simulator. Vehicle mobility and network communication are integrated through events. User-created event handlers can send network messages or alter vehicle mobility each time a network message is received and each time vehicle mobility is updated by the model. To aid in creating simulations, we have implemented a straight highway model that manages vehicle mobility, while allowing for various user customizations. We show that the results of our implementation of the mobility model matches that of the model's author and provide and example of using our implementation in ns-3.
Fundamentals and applications of ion–ion plasmas

Abstract Ion–ion plasmas can form in the late afterglow of pulsed discharges or downstream of continuous wave discharges in electronegative gases. In ion–ion plasmas, negative ions replace electrons as the negative charge carriers. In the absence of electrons, ion–ion plasmas behave quite differently compared to conventional electron–ion plasmas. Application of a radio frequency bias to a substrate immersed in an ion–ion plasma can be used to extract alternately positive and negative ions, thereby minimizing charging on device features during micro-device fabrication. Ion–ion plasmas are also important in negative ion sources, dusty plasmas, and the D-layer of the earth's atmosphere.
THEORETICAL SPECTRA OF TERRESTRIAL EXOPLANET SURFACES

We investigate spectra of airless rocky exoplanets with a theoretical framework that self-consistently treats reflection and thermal emission. We find that a silicate surface on an exoplanet is spectroscopically detectable via prominent Si‐O features in the thermal emission bands of 7‐13 μm and 15‐25 μm. The variation of brightness temperature due to the silicate features can be up to 20 K for an airless Earth analog, and the silicate features are wide enough to be distinguished from atmospheric features with relatively high resolution spectra. The surface characterization thus provides a method to unambiguously identify a rocky exoplanet. Furthermore, identification of specific rocky surface types is possible with the planet’s reflectance spectrum in near-infrared broad bands. A key parameter to observe is the difference between K-band and J-band geometric albedos (Ag(K) − Ag(J )): Ag(K) − Ag(J ) > 0.2 indicates that more than half of the planet’s surface has abundant mafic minerals, such as olivine and pyroxene, in other words primary crust from a magma ocean or high-temperature lavas; Ag(K) − Ag(J ) < −0.09 indicates that more than half of the planet’s surface is covered or partially covered by water ice or hydrated silicates, implying extant or past water on its surface. Also, surface water ice can be specifically distinguished by an H-band geometric albedo lower than theJ-band geometric albedo. The surface features can be distinguished from possible atmospheric features with molecule identification of atmospheric species by transmission spectroscopy. We therefore propose that mid-infrared spectroscopy of exoplanets may detect rocky surfaces, and near-infrared spectrophotometry may identify ultramafic surfaces, hydrated surfaces, and water ice.
Regulatory functions of the three nodD genes of Rhizobium leguminosarum biovar phaseoli.

Summary The three nodD genes of a strain of Rhizobium leguminosarum biovar phaseoli were cloned to study their effects on transcription of themselves and of the nodC genes of biovars phaseoli and viciae. Efficient transcription of nodD1 required nodD1 and was enhanced by exposure of the cells to bean exudate consistent with the presence of a nod-box preceding the nolE-nodD1 operon. Transcription of nodD2 and nodDZ was constitutive. nodC of R. leguminosarum biovar phaseoli was activated by each of the nodD genes of that biovar in the absence of inducers but expression was enhanced in cells grown with bean exudate or the flavonoids genistein or naringenin. A mutant of nodD2, tacking 60bp at its 3’end, activated nodC in the presence of inducer, but was defective in regulating certain of the nodD genes. The nodC gene of R. leguminosarum biovar viciae responded differently to the various nodD genes of R. leguminosarum biovar phaseoli than did the nodC of the latter biovar.
Synthesis and Application of Chiral Phospholane Ligands Bearing a Sterically and Electrically Adjustable Moiety

A series of C1-symmetric phosphine-phospholane ligands, 1-(disubstituted phosphino)-2-(phospholano)benzenes (5), which are called UCAPs, with an achiral phosphino group and a chiral phospholane which can be sterically and electrically adjustable, has been designed and synthesized. In the asymmetric hydrogenation of (Z)-N-benzoyl-1-phenylpropenamine (3), the stereorecognition abilities of the 5d−e–Rh catalysts which have a bulkier aryl substituent on the achiral phosphorus are superior to that observed with the DuPHOS-Rh catalyst. The effects of varying substituents on the achiral phosphorus atom are discussed.
A note on equations for steady‐state optimal landscapes

Based on the optimality principle (that the global energy expenditure rate is at its minimum for a given landscape under steady state conditions) and calculus of variations, we have derived a group of partial differential equations for describing steady-state optimal landscapes without explicitly distinguishing between hillslopes and channel networks. Other than building on the well-established Mining's equation, this work does not rely on any empirical relationships (such as those relating hydraulic parameters to local slopes). Using additional constraints, we also theoretically demonstrate that steady-state water depth is a power function of local slope, which is consistent with field data.
Deoxygenation of biomass-derived feedstocks: oxorhenium-catalyzed deoxydehydration of sugars and sugar alcohols.

The conversion of renewable cellulosic biomass into fuels and chemicals has attracted increased attention with the growing demand for sustainability. However, one fundamental challenge is that saccharides, the major component of cellulosic biomass, are highly oxygen-rich when compared with the majority of current commodity chemicals and fuels. The polyol structure also generally presents poor solubility in organic solvents, thermal instability, and limited scope for functionalization, making its chemical manipulation difficult. Therefore, efficient deoxygenation reactions of sugars and sugar derivatives need to be developed. Current methods are dominated by the high-temperature pyrolysis, acid-catalyzed dehydration, and hydrogenolysis reactions. A much less developed deoxygenation pathway is the deoxydehydration (DODH) reaction, which removes two adjacent hydroxy groups from vicinal diols to afford alkenes (Scheme 1).
Nonlinear viscoelasticity of metastable complex fluids

Many metastable complex fluids such as colloidal glasses and gels show distinct nonlinear viscoelasticity with increasing oscillatory-strain amplitude; the storage modulus decreases monotonically as the strain amplitude increases whereas the loss modulus has a distinct peak before it decreases at larger strains. We present a qualitative argument to explain this ubiquitous behavior and use mode-coupling theory (MCT) to confirm it. We compare theoretical predictions to the measured nonlinear viscoelasticity in a dense hard-sphere colloidal suspension; reasonable agreement is obtained. The argument given here can be used to obtain new information about linear viscoelasticity of metastable complex fluids from nonlinear strain measurements.
Retrofitting Fairness on the Original RSA-Based E-cash

The notion of fair e-cash schemes was suggested and implemented in the last decade. It balances anonymity with the capability of tracing users and transactions in cases of crime or misbehavior. The issue was raised both, in the banking community and in the cryptographic literature. A number of systems were designed with an off-line fairness, where the tracing authorities get involved only when tracing is needed. However, none of them is based on the original RSA e-cash. Thus, an obvious question is whether it is possible to construct an efficient fair e-cash scheme by retrofitting the fairness mechanism on the original RSA-based scheme. The question is interesting from, both, a practical perspective (since investment has been put in developing software and hardware that implement the original scheme), and as a pure research issue (since retrofitting existing protocols with new mechanisms is, at times, harder than designing solutions from scratch). In this paper, we answer this question in the affirmative by presenting an efficient fair off-line e-cash scheme based on the original RSA-based one.
Transverse Mercator with an accuracy of a few nanometers

Implementations of two algorithms for the transverse Mercator projection are described; these achieve accuracies close to machine precision. One is based on the exact equations of Thompson and Lee and the other uses an extension of Kruger’s series for the mapping to higher order. The exact method provides an accuracy of 9 nm over the entire ellipsoid, while the errors in the series method are less than 5 nm within 3900 km of the central meridian. In each case, the meridian convergence and scale are also computed with similar accuracy. The speed of the series method is competitive with other less accurate algorithms and the exact method is about five times slower.
Hierarchical multi-dimensional table lookup for model compiler based circuit simulation

In this paper, a systematic method for automatically generating hierarchical multi-dimensional table lookup models for compact device and behavioral models with any number of terminals is presented. The method is based on an Abstract Syntax Tree representation of analytic equations. Expensive part of the computations represented by abstract syntax trees are identified and replaced by two-dimensional table lookup models. An error-control based optimization algorithm is developed to generate table lookup models with the minimal amount of table data for a given accuracy requirement. The proposed method has been implemented in the model compiler MCAST and the circuit simulator SPICE3. Experimental results show that, compared to non-optimized compilation based simulation, the simulation using the proposed table lookup optimization method is about 40 times faster and achieves sufficiently accurate results with error less than 1-2%.
A new strategy for the synthesis of β-benzylmercaptoethylamine derivatives.

Abstract Here, we describe a new experimental approach to the synthesis of the β-benzylmercaptoethylamine functionality, and illustrate its synthetic utility in multi-component reactions. Although prevalent in modern organic synthesis, no general methods have been described for this functionality. Using a carefully developed LiOH–water–ethanol reaction mixture, we were able to produce a diverse collection of β-benzylmercaptoethylamines containing a range of sensitive functional groups in excellent yields. To further illustrate their utility in molecular library synthesis, we also report the use of β-benzylmercaptoethylamines in five different multi-component reactions.
An adaptive controller based on disturbance attenuation

This paper discusses the control of linear systems with uncertain parameters in the control coefficient matrix, under the influence of both process and measurement noise. A disturbance attenuation approach is used, and from this a multiplayer game problem is generated. First, the minimax formulation is presented, which represents an upper bound on the game cost criterion. Second, a dynamic programming approach is used to solve the game. It is necessary to significantly extend the method over earlier implementations, as the class of problems does not satisfy certain assumptions generally made. It is shown that for this class of problems, the controller determined from the dynamic programming approach is equivalent to the minimax controller. Therefore, the minimax controller is also a saddlepoint strategy for the differential game. Controller development appears to be much simpler from the dynamic programming standpoint. A simple scalar example is presented. >
Annihilation Fountain in the Galactic Center Region

Two different model-independent mapping techniques have been applied to Compton Gamma Ray Observatory OSSE, SMM, TGRS, and balloon data and reveal a feature in the 0.511 MeV e+-e- annihilation radiation pattern of our Galaxy centered at l ~ -2° and b ~ 10° with a flux of approximately 5 × 10-4 0.511 MeV photons cm-2 s-1. If near the Galactic center, then positron (e+) sources are producing about 1042 e+ s-1, which annihilate ≈ 1-2 kpc above the Galactic plane. A starburst episode within the inner few hundred parsecs of our Galaxy would drive hot pair-laden gas into the halo, with the one-sidedness pointing to the site of initial pressure release at the onset of the starburst activity. Positrons lose energy and annihilate as they are convected upward with the gas flow, and we calculate high-latitude annihilation patterns and fluxes in accord with the observations. Changes in the ionization state when the escaping gas cools could give annihilation radiation substructure. The fountain of hot (~106-107 K) gas rising into the Galactic halo would be seen through its enhanced dispersion measure, thermal emission, and recombination radiation.
Target Space Duality II: Applications

Abstract We apply the framework developed in Target space duality I: general theory. We show that both nonabelian duality and Poisson–Lie duality are examples of the general theory. We propose how the formalism leads to a systematic study of duality by studying few scenarios that lead to open questions in the theory of Lie algebras. We present evidence that there are probably new examples of irreducible target space duality.
Palladium-catalyzed enantioselective C-3 allylation of 3-substituted-1H-indoles using trialkylboranes.

We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indolenines to oxindoles has also been developed and led to a formal synthesis of (−)-phenserine.
Individual nanostructured materials: fabrication and surface-enhanced Raman scattering

The progress of surface-enhanced Raman scattering (SERS) microscopy and spectroscopy on individual nanostructured materials has been reviewed in this feature article. After a brief introduction on individual nanomaterial SERS, we provide a systematic overview on the fabrication and SERS studies of individual nanoparticulates, nano-junctions and hierarchical nano-aggregate. These SERS-active nanomaterials have great potential in designing novel highly sensitive SERS substrates for the development of SERS-based sensing devices with a broad range of applications.
Identification of supply models of retailer and manufacturer oligopoly pricing

Abstract We present sufficient conditions for data on an industry's product prices, quantities, and input prices to identify retailers' and manufacturers' vertical supply model. Identification requires nonlinear demand for homogeneous products and multi-product firms with non-constant markups for differentiated products.
Added Mass of High-Altitude Balloons

Acoustic theory is used to find the added mass for several rigid, immersed bodies. The classical cases of a thin circular disk and a sphere are used to determine the mesh fineness required for engineering accuracy. A family of five Smalley-shaped balloons (zero circumferential stress in the film) is then considered, at different inflation ratios. Acoustical boundary elements are used. The fluid is assumed incompressible and, therefore, the added masses are identical in spirit with those from hydrodynamics. Although not important for this study, compressibility effects can be included for other bodies, if needed. Both vertical and horizontal accelerations are considered. Results show that the pear-shaped balloons behave in an intermediate way between spheres and cylinders, as expected. Such accurate values for added mass will allow better simulation of balloon flight, particularly for dynamic motion resulting from ballast or pay load drop. A major feature of this article is to demonstrate the feasibility of calculating added masses for arbitrarily shaped bodies using acoustics. The authors feel this approach will become a standard working tool for studies of immersed bodies such as balloons, parachutes, and submarines because of the ease of computation. The method uses commercial finite element preprocessors for building the model, calculation of enclosed volumes, and transferring rigid body information to the acoustic computer program.
VENEZIANO AMPLITUDES, SPIN CHAINS, AND STRING MODELS

In a series of recently published papers, we reanalyzed the existing treatments of Veneziano and Veneziano-like amplitudes and the models associated with these amplitudes. In this work, we demonstrate that the already obtained new partition function for these amplitudes can be exactly mapped into that for the Polychronakos–Frahm spin chain model. This observation allows us to recover many of the existing string-theoretic models, including the most recent ones.
Randomized Minmax Regret for Combinatorial Optimization Under Uncertainty

The minmax regret problem for combinatorial optimization under uncertainty can be viewed as a zero-sum game played between an optimizing player and an adversary, where the optimizing player selects a solution and the adversary selects costs with the intention of maximizing the regret of the player. The conventional minmax regret model considers only deterministic solutions/strategies, and minmax regret versions of most polynomial solvable problems are NP-hard. In this paper, we consider a randomized model where the optimizing player selects a probability distribution (corresponding to a mixed strategy) over solutions and the adversary selects costs with knowledge of the player’s distribution, but not its realization. We show that under this randomized model, the minmax regret version of any polynomial solvable combinatorial problem becomes polynomial solvable. This holds true for both interval and discrete scenario representations of uncertainty. Using the randomized model, we show new proofs of existing approximation algorithms for the deterministic model based on primal-dual approaches. We also determine integrality gaps of minmax regret formulations, giving tight bounds on the limits of performance gains from randomization. Finally, we prove that minmax regret problems are NP-hard under general convex uncertainty.
Estimated errors in |Vcd|/|Vcs| from semileptonic D decays

Abstract We estimate statistical and systematic errors in the extraction of the CKM ratio |Vcd|/|Vcs| from exclusive D-meson semileptonic decays using lattice QCD and anticipated new experimental results.
Numerical solution of transonic stream function equation

The stream function equation, in conservation form, looks similar to the full potential equation and existing methods (e.g. artificial compressibility) can be readily applied. Rotational flows can be calculated once the vorticity (due to shocks or nonuniformity) is evaluated. There are, however, two main difficulties: First, the density is not uniquely determined in terms of the flux (there are two solutions; the subsonic and the supersonic branch with a square root singularity at the sonic point). Methods to overcome this difficulty are studied and results are presented with some remarks on inviscid separation and closed stream lines. Second, the need of two stream functions for three dimensional calculations is briefly discussed.
Dielectric Constant of Compressed Gaseous and Liquid Oxygen.

The dielectric constants of compressed gaseous and liquid oxygen were measured on ten isoterms at temperatures between 100 and 300 K and on the saturated liquid boundary at temperatures between 55 and 154 K. Densities ranged from 0.06 to 1.30 grams per cu cm at pressures up to 33 MN per sq m. The dielectric constant measurements were combined with accurate density data to compute the Clausius-Mossotti function. This function was found to decrease for oxygen with density from a value of 0.1236 cu cm per gram at the low density limit to 0.1219 cu cm per gram near the triple point.
Expenditures and Postsecondary Graduation: An Investigation Using Individual-Level Data from the State of Ohio.

Abstract Using detailed individual-level data from public universities in the state of Ohio, I estimate the effect of various institutional expenditures on the probability of graduating from college. Using a competing risks regression framework, I find differential impacts of expenditure categories across student characteristics. I estimate that student service expenditures have a larger impact on students with low SAT/ACT scores, while instructional expenditures are more important for high test score students and those majoring in scientific/quantitative fields. The individual-level nature of these data allows me to address measurement error and endogeneity concerns the previous literature has been unable to deal with.
How to convexify the intersection of a second order cone and a nonconvex quadratic

A recent series of papers has examined the extension of disjunctive-programming techniques to mixed-integer second-order-cone programming. For example, it has been shown--by several authors using different techniques--that the convex hull of the intersection of an ellipsoid, $$\mathcal {E}$$E, and a split disjunction, $$(l - x_j)(x_j - u) \le 0$$(l-xj)(xj-u)≤0 with $$l < u$$l
Transforming Government and Empowering Communities: The Sri Lankan Experience with e-Development

This book focuses on the institutional innovations needed to lead the diffusion of the new information and communication technology (ICT) that can help transform developing economies into knowledge economies and information societies. It shows that developing e-leadership institutions is a long-term process, fraught with uncertainties, but a process that remains at the heart of implementing ICT-enabled development strategies. It focuses on improving governance and the delivery of public services, bridging economic divides, promoting social inclusion, and drastically cutting transaction costs across the economy. It seeks to exploit new sources of growth, employment, and competitiveness by promoting the ICT and IT-enabled services industries and the use of ICT by small enterprises to network and compete. This book draws on the experience of Sri Lanka to explore what is involved in moving from vision to implementation of a comprehensive e-development strategy-the e-Sri Lanka program. The focus is on building local e-leadership institutions to drive this process and leveraging ICT to transform government and empower communities through e-government and e-society. Finally, to allow sound selection and management of projects, particularly in a national context, it is critical that the program be free from pressure by government, private companies, or others that may seek to use the program to exercise their influence.
Zames-Falb multipliers for MIMO nonlinearities

Zames and Falb (1968) determined a class of multipliers that preserve positivity of monotone SISO nonlinearities. They conjectured that their results might also hold for incrementally positive, norm-bounded MIMO nonlinearities. In this note, we demonstrate that their conjecture regarding MIMO nonlinearities holds true only if a further restriction is applied. Specifically, we show that it suffices either to restrict the nonlinearity to be the gradient of a convex real-valued function or to restrict the multiplier to be a real-valued function of frequency.
Dynamic allocation of visual attention during the execution of sequences of saccades

Laboratory tasks used to study vision and attention usually require steady fixation, while natural visual processing occurs during the brief pauses between successive saccades. We studied vision and attentional allocation during intersaccadic pauses as subjects made repetitive sequences of saccades. Displays contained six outline squares located along the perimeter of an imaginary circle (diam 4� ). Saccades were made in sequence to every other square. The visual task was to identify the orientation (2AFC) of a Gabor test stimulus that appeared briefly (91 ms) along with superimposed noise in one of the squares during a randomly selected intersaccadic pause. Gabor location was cued in advance and noise frames were presented in all squares. Contrast thresholds during intersaccadic pauses were as much as 2–3 times higher than during steady fixation with comparable cueing. Thresholds improved over time during the intersaccadic pause, and the lowest extrafoveal thresholds (statistically indistinguishable from those at the same locations during steady fixation) were found for the location that was to be the target of the next saccade in the sequence. These results show that vision during intersaccadic pauses varies over space and time due to changes in the distribution of attention, as well as to visual suppression that may be related to the execution of the saccades themselves. Generation of sequences of accurate saccades encouraged a strategy of attentional allocation in which resources were dedicated primarily to the goal of the next saccade, leaving little attention for processing objects at other locations. � 2004 Elsevier Ltd. All rights reserved.
A Proximal-Gradient Homotopy Method for the Sparse Least-Squares Problem

We consider solving the $\ell_1$-regularized least-squares ($\ell_1$-LS) problem in the context of sparse recovery for applications such as compressed sensing. The standard proximal gradient method, also known as iterative soft-thresholding when applied to this problem, has low computational cost per iteration but a rather slow convergence rate. Nevertheless, when the solution is sparse, it often exhibits fast linear convergence in the final stage. We exploit the local linear convergence using a homotopy continuation strategy, i.e., we solve the $\ell_1$-LS problem for a sequence of decreasing values of the regularization parameter, and use an approximate solution at the end of each stage to warm start the next stage. Although similar strategies have been studied in the literature, there have been no theoretical analysis of their global iteration complexity. This paper shows that under suitable assumptions for sparse recovery, the proposed homotopy strategy ensures that all iterates along the homotopy sol...
Relational Reasoning in a Neurally Plausible Cognitive Architecture An Overview of the LISA Project

Human mental representations are both flexible and structured—properties that, together, present challenging design requirements for a model of human thinking. The Learning and Inference with Schemas and Analogies (LISA) model of analogical reasoning aims to achieve these properties within a neural network. The model represents both relations and objects as patterns of activation distributed over semantic units, integrating these representations into propositional structures using synchrony of firing. The resulting propositional structures serve as a natural basis for memory retrieval, analogical mapping, analogical inference, and schema induction. The model also provides an a priori account of the limitations of human working memory and can simulate the effects of various kinds of brain damage on thinking.
Parity and Predictability of Competitions

We present an extensive statistical analysis of the results of all sports competitions in five major sports leagues in England and the United States. We characterize the parity among teams by the variance in the winning fraction from season-end standings data and quantify the predictability of games by the frequency of upsets from game results data. We introduce a novel mathematical model in which the underdog team wins with a fixed upset probability. This model quantitatively relates the parity among teams with the predictability of the games, and it can be used to estimate the upset frequency from standings data.
Application of diazene-directed fragment assembly to the total synthesis and stereochemical assignment of (+)-desmethyl-meso-chimonanthine and related heterodimeric alkaloids

We describe the first application of our methodology for heterodimerization via diazene fragmentation towards the total synthesis of (−)-calycanthidine, meso-chimonanthine, and (+)-desmethyl-meso-chimonanthine. Our syntheses of these alkaloids feature an improved route to C3a-aminocyclotryptamines, an enhanced method for sulfamide synthesis and oxidation, in addition to a late-stage diversification leading to the first enantioselective total synthesis of (+)-desmethyl-meso-chimonanthine and its unambiguous stereochemical assignment. This versatile strategy for directed assembly of heterodimeric cyclotryptamine alkaloids has broad implications for the controlled synthesis of higher order derivatives with related substructures.
EFFECTS OF URBANIZATION ON ORGANIC CARBON LOADS IN THE SACRAMENTO RIVER, CALIFORNIA

[1] To gain better understanding of the effects of urbanization on organic matter transport in rivers, we quantified total organic carbon loading from point and non-point urban sources within the metropolitan area of Sacramento and compared these loads to the amount of organic carbon carried in the downstream Sacramento River. Median total organic carbon (TOC) concentrations in the Sacramento River, non-point urban runoff and wastewater treatment plant effluent were 2.1, 8.9, and 23 mg L−1, respectively. Dissolved organic carbon (DOC) in non-point runoff and the river had similar specific UVA absorbance and disinfection by-product formation potential, but based on radiocarbon measurements, non-point DOC was substantially older (age > 2000 a) than DOC in the Sacramento River. This finding suggests that DOC in non-point runoff is derived primarily from leaching of older soil organic matter. The 10th, 50th, 90th and 99th percentile contributions of urban sources to daily TOC load in the Sacramento River were 10%, 20%, 38% and 80%, respectively. Total urban TOC yield was 150 kg ha−1yr−1 and urban sources contributed ∼17% of the annual load of TOC in the Sacramento River below Sacramento.
Absorbing set spectrum approach for practical code design

This paper focuses on controlling the absorbing set spectrum for a class of regular LDPC codes known as separable, circulant-based (SCB) codes. For a specified circulant matrix, SCB codes all share a common mother matrix, examples of which are array-based LDPC codes and many common quasi-cyclic codes. SCB codes retain the standard properties of quasi-cyclic LDPC codes such as girth, code structure, and compatibility with efficient decoder implementations. In this paper, we define a cycle consistency matrix (CCM) for each absorbing set of interest in an SCB LDPC code. For an absorbing set to be present in an SCB LDPC code, the associated CCM must not be full column-rank. Our approach selects rows and columns from the SCB mother matrix to systematically eliminate dominant absorbing sets by forcing the associated CCMs to be full column-rank. We use the CCM approach to select rows from the SCB mother matrix to design SCB codes of column weight 5 that avoid all low-weight absorbing sets (4; 8), (5; 9), and (6; 8). Simulation results demonstrate that the newly designed code has a steeper error-floor slope and provides at least one order of magnitude of improvement in the low error rate region as compared to an elementary array-based code.
Measuring the Effect of Federal Research Funding on Private Donations at Research Universities: Is Federal Research Funding More than a Substitute for Private Donations?

The nature of federal research funding has changed in the United States over the last 30 years. In part, federal research funding has changed in the distribution of funding across disciplines and across universities. Federal funding to universities with historically low levels of funding has also experienced greater growth than those universities with historically high levels of funding. In addition, universities have become more involved in the political process with respect to the allocation of funding for higher education. As the nature of government funding changes, this paper questions its effect on private donations to research and non-research universities. The general presumption of much of the existing theoretical work is that government and private funding for charitable goods are substitutes. Limited evidence exists to suggest, in some circumstances, there may be a positive correlation between these two sources of funding. Potentially, because the government undertakes the expense to gather information about the research universities, and engages in such activities as peer-review of research proposals, the government through its grant awards may provide a signal of quality of research or other information to donors that is less noisy than that available to private donors. Similarly, there may be other types of spillover effects from research funding to private donations. In this case, a change in government grants has both a positive and negative effect on private donations, suggesting a positive correlation between private and public donations if the effect from the dissemination of information is greater than the substitution effect of government grants. I examine data for private and public universities in the United States to measure the relationship between private and public donations under a fixed-effects OLS regression. I explore issues of bias from endogeneity or omitted variables and report the results from a two stage least squares regression in which I use a set of measures that affect federal research funding but not private donations. Regardless of the specification, the results suggest private and public donations are positively correlated for research universities and negatively correlated for non-research institutions. On average, increasing federal research funding by one dollar increases private donations by 65 cents at research universities, decreases private donations by 9 cents at universities whose highest degree granted is a masters, and decreases private donations by 45 cents at liberal arts colleges.
Efficient search, mapping, and optimization of multi‐protein genetic systems in diverse bacteria

Developing predictive models of multi-protein genetic systems to understand and optimize their behavior remains a combinatorial challenge, particularly when measurement throughput is limited. We developed a computational approach to build predictive models and identify optimal sequences and expression levels, while circumventing combinatorial explosion. Maximally informative genetic system variants were first designed by the RBS Library Calculator, an algorithm to design sequences for efficiently searching a multi-protein expression space across a > 10,000-fold range with tailored search parameters and well-predicted translation rates. We validated the algorithm's predictions by characterizing 646 genetic system variants, encoded in plasmids and genomes, expressed in six gram-positive and gram-negative bacterial hosts. We then combined the search algorithm with system-level kinetic modeling, requiring the construction and characterization of 73 variants to build a sequence-expression-activity map (SEAMAP) for a biosynthesis pathway. Using model predictions, we designed and characterized 47 additional pathway variants to navigate its activity space, find optimal expression regions with desired activity response curves, and relieve rate-limiting steps in metabolism. Creating sequence-expression-activity maps accelerates the optimization of many protein systems and allows previous measurements to quantitatively inform future designs.
Cost-Effectiveness Analysis in the Courts: Recent Trends and Future Prospects

This article provides an initial look at how managed care organizations (MCOs) might incorporate cost-effectiveness analysis (CEA) into their decision- making process and how the courts might respond. Because so few medical liability cases directly involve CEA, we must look at other areas of the law to assess poten- tial MCO liability for applying CEA. In general negligence cases, courts rely on a risk-benefit test to determine customary practice. Likewise, in product liability cases, courts use a risk-utility calculus to determine liability for product design defects. And in challenges to government regulation, courts examine how agencies use CEA to set regulatory policy. The results have been mixed. In product liability cases, CEA has led to some punitive damage awards against automobile manufacturers. But courts have integrated it in negligence cases without generating juror antipathy, and gener- ally defer to agency expertise in how to incorporate CEA. The article discusses the implications of these cases for MCO use of CEA and outlines various options for set- ting the standard of care in the managed care era.
Real-Time Scanning Charged-Particle Microscope Image Composition with Correction of Drift

In this article, a new scanning electron microscopy (SEM) image composition technique is described, which can significantly reduce drift related image corruptions. Drift distortion commonly causes blur and distortions in the SEM images. Such corruption ordinarily appears when conventional image-acquisition methods, i.e., “slow scan” and “fast scan,” are applied. The damage is often very significant; it may render images unusable for metrology applications, especially where subnanometer accuracy is required. The described correction technique works with a large number of quickly taken frames, which are properly aligned and then composed into a single image. Such image contains much less noise than the individual frames, while the blur and deformation is minimized. This technique also provides useful information about changes of the sample position in time, which may be applied to investigate the drift properties of the instrument without a need of additional equipment.
Grain Growth of the Lime and Periclase Phases in a Synthetic Doloma

Simultaneous grain growth of the lime (CaO) and periclase (MgO) phases was studied in a synthetic, hydroxide-derived doloma over the temperature range 1400° to 1700°C. The grain growth kinetic exponents were 5 and 6 and the activation energies 333±45 and 437±47 kJ/mol for the CaO and MgO phases, respectively. The large kinetic exponents are attributed to the topological restraints of the two phases on the growth of one another. The parameters suggest that the grain growth of the CaO may be governed by Ca2+ diffusion within the CaO phase for it is the continuous phase in the microstructure. In most instances for grain growth of the MgO phase, the Mg2+ must diffuse through the lime phase, and this process is believed to be limited by movement of associated defects involving Mg2+ within the CaO structure.
DISTRIBUTED FLAMES IN TYPE Ia SUPERNOVAE

At a density near a few ×10 7 gc m −3 , the subsonic burning in a Type Ia supernova (SN) enters the distributed regime (high Karlovitz number). In this regime, turbulence disrupts the internal structure of the flame, and so the idea of laminar burning propagated by conduction is no longer valid. The nature of the burning in this distributed regime depends on the turbulent Damk¨ ohler number (DaT ), which steadily declines from much greater than one to less than one as the density decreases to a few ×10 6 gc m −3 . Classical scaling arguments predict that the turbulent flame speed sT , normalized by the turbulent intensity ˇ u, follows sT / ˇ u = Da 1/2 T for DaT 1. The flame in this regime is a single turbulently broadened structure that moves at a steady speed, and has a width larger than the integral scale of the turbulence. The scaling is predicted to break down at DaT ≈ 1, and the flame burns as a turbulently broadened effective unity Lewis number flame. This flame burns locally with speed sλ and width lλ, and we refer to this kind of flame as a λ-flame. The burning becomes a collection of λ-flames spread over a region approximately the size of the integral scale. While the total burning rate continues to have a well-defined average, sT ∼ˇ u, the burning is unsteady. We present a theoretical framework, supported by both one-dimensional and three-dimensional numerical simulations, for the burning in these two regimes. Our results indicate that the average value of sT can actually be roughly twice ˇ u for DaT 1, and that localized excursions to as much as 5 times ˇ u can occur. We also explore the properties of the individual flames, which could be sites for a transition to detonation when DaT ∼ 1. The λ-flame speed and width can be predicted based on the turbulence in the star (specifically the energy dissipation rate e ∗ ) and the turbulent nuclear burning timescale of the fuel τ T nuc .W e propose a practical method for measuring sλ and lλ based on the scaling relations and small-scale computationally inexpensive simulations. This suggests that a simple turbulent flame model can be easily constructed suitable for large-scale distributed SNe flames. These results will be useful both for characterizing the deflagration speed in larger full-star simulations, where the flame cannot be resolved, and for predicting when detonation occurs.
A new diaza‐18‐crown‐6 ligand containing two quinolin‐8‐ylmethyl side arms: Crystal structures and characterization of the ligand, the protonated ligand and its mononuclear barium(II) and dinuclear copper(II) complexes

A new 7,16-bis(quinolin-8-ylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane ligand, L, has been prepared and its crystal structure reported. In addition, the structure of the protonated ligand H2L has been determined. H2L is of interest because of interatomic interactions between the ligand and perchlorate ions. The mononuclear Ba(II) (BaL), and dinuclear Cu(II) (Cu2L) complexes of L have been prepared and their crystal structures determined. Stability constants and other thermodynamic data valid in methanol at 23 or 25° for these and several other complexes of L have been obtained. Among the metal ions studied, L forms the most stable complex with Ba2+. In addition, L selectively binds Cu2+ over Ni2+ by about 3 orders of magnitude. Some of the complexes have been studied using nmr and uv-vis spectroscopic techniques. Crystal data are given for L, space group, P21c, a = 8.8325(14) A, b = 13.808(3) A, c = 13.310(3) A; β = 94.72(2)° Z=2, R = 0.0727; for H2L, space group, P21/c, a = 14.685(3) A, b = 15.035(6) A, c = 17.369(4) A, β = 90.366(12)°, Z = 4, R = 0.0781; for BaL, space group, Pbcn, a = 17.314(3) A, b = 9.539(2) A, c = 22.081(3) A, Z = 4, R = 0.0354; and for Cu2L, space group, Cc, a = 19.762(2) A, b = 14.413(2) A, c = 14.935(2) A, β = 98.753(12)°, Z = 4, R = 0.0564. Cu2+ forms a hydroxo-bridged dinuclear complex with L while Ba2+ forms a mononuclear complex with L in which its two side arms are not involved in complexation.
Transcript length mediates developmental timing of gene expression across Drosophila

The time required to transcribe genes with long primary transcripts may limit their ability to be expressed in cells with short mitotic cycles, a phenomenon termed intron delay. As such short cycles are a hallmark of the earliest stages of insect development, we tested the impact of intron delay on the Drosophila developmental transcriptome. We find that long zygotically expressed genes show substantial delay in expression relative to their shorter counterparts, which is not observed for maternally deposited transcripts. Patterns of RNA-seq coverage along transcripts show that this delay is consistent with their inability to completely transcribe long transcripts, but not with transcriptional initiation-based regulatory control. We further show that highly expressed zygotic genes maintain compact transcribed regions across the Drosophila phylogeny, allowing conservation of embryonic expression patterns. We propose that the physical constraints of intron delay affect patterns of expression and the evolution of gene structure of a substantial portion of the Drosophila transcriptome.
Adaptive lattice filter implementations on pipelined multiprocessor architectures

Three pipelined multiprocessor implementations of adaptive lattice filters are examined. A performance analysis is done for each multiprocessor system, and expressions for approximate computation time and speedup are derived. Each system is shown to be flexible with respect to the different algorithms and the different filter sizes it can implement. >
The Effects of Halo Assembly Bias on Self-Calibration in Galaxy Cluster Surveys

Self-calibration techniques for analyzing cluster counts rely on using the abundance and the clustering amplitude of clusters to simultaneously constrain cosmological parameters and the relation between halo mass and its observable mass tracer. It was recently discovered t hat the clustering amplitude of halos depends not only on halo mass, but also on various secondary variables such as halo formation time and concentration; these dependences are collectively termed “assembly bias.” Using a modified Fisher matrix formalism, we explore whether these secondary variables have a significan t impact on studying the properties of dark energy with self calibration in current (SDSS) and near future (DES, SPT, and LSST) cluster surveys. We find that for an SDSS-like survey, secondary dependences of halo bias are insignificant given the expected large statistical uncertainties in dark energy parameters. For SPT- or DES-like survey volumes, we find that the dependence of halo bias on secondary variables is not a significant syste matic provided the scatter in the observable‐mass relation is 20% or lower, as expected for X-ray or SZ surveys. At higher scatter (e.g. values currently possible with optical surveys), significant systematic errors are po ssible, depending on how strongly the cluster observable correlates with the secondary variables at fixed mass. F or an LSST-like survey volume, this systematic is likely to be important even for lower scatter values or for le ss correlated observables.