cssi/SciSciGPT-SciSciNet huggingface dataset:
Interatomic potentials and defect energetics in dilute alloys

Effective interatomic potentials for impurities in aluminum have been constructed according to pseudopotential theory. Based on a local model potential, impurity valence and size factors are defined and their effects on the potential discussed. With these potentials, detailed calculations based on a Green's function lattice statics method are made for the impurity-vacancy binding energy and the difference in diffusion activation energies for an impurity and a host atom. Within the range of valence and size factors studied, it is found that the binding energy is generally small and depends primarily on the valence rather than the size, whereas the migration energy shows larger increases with both valence and size factors. Contributions from the lattice relaxation energies are important, particularly for impurity migration. The results can account satisfactorilfyo r the experimental data of nontransition-metal impurities, but lesss o for the noble-metal impurities. Dielectric screeningof the ion by the conduction electrons is important in determining the potential and must be properly accounted for in calculations of the energetics for impurities.
A Closer Look at Oil, Diamonds, and Civil War

▪ Abstract Studies of natural resource wealth and civil war have been hampered by measurement error, endogeneity, lack of robustness, and uncertainty about causal mechanisms. This paper develops new measures and new tests to address these problems. It has four main findings. First, the likelihood of civil war in countries that produce oil, gas, and diamonds rose sharply from the early 1970s to the late 1990s; so did the number of rebel groups that sold contraband to raise money. Second, exogenous measures of oil, gas, and diamond wealth are robustly correlated with the onset of civil war. Still, these correlations are based on a small number of cases, and the substantive effects of resource wealth are sensitive to certain assumptions. Third, petroleum and diamond production lead to civil wars through at least three different mechanisms. Finally, the only resource variable robustly linked to conflict duration is a measure of “contraband,” which includes gemstones, timber, and narcotics.
MOLECULAR MODELING IN THE DISCOVERY OF DRUG LEADS

The National Cancer Institute of the U.S.A. maintains a repository of about 500 000 chemicals which it has tested at some time for anticancer activity. As new chemotherapeutic targets present themselves, methods have been developed by which this large database can be re-examined without resorting to expensive high-volume biological screening. Electronic screening, the method described in this paper, begins with the identification of a target enzyme. The pharmacophore used by the enzyme in binding to substrates is identified, and then all compounds in the database that contain the pharmacophore are found. These compounds are then further filtered, for example, by physical properties such as solubility, and the relatively small number of compounds that survive are submitted for biological testing. This use of a primary electronic screen in the search for ligands of protein kinase C is described. The screen is very fast, and the method is quite generally applicable to different enzymes.
Scheduling with rate adaptation under incomplete knowledge of channel/estimator statistics

In time-varying wireless networks, the states of the communication channels are subject to random variations, and hence need to be estimated for efficient rate adaptation and scheduling. The estimation mechanism possesses inaccuracies that need to be tackled in a probabilistic framework. In this work, we study scheduling with rate adaptation in single-hop queueing networks under two levels of channel uncertainty: when the channel estimates are inaccurate but complete knowledge of the channel/estimator joint statistics is available at the scheduler; and when the knowledge of the joint statistics is incomplete. In the former case, we characterize the network stability region and show that a maximum-weight type scheduling policy is throughput-optimal. In the latter case, we propose a joint channel statistics learning - scheduling policy. With an associated trade-off in average packet delay and convergence time, the proposed policy has a stability region arbitrarily close to the stability region of the network under full knowledge of channel/estimator joint statistics.
The Impact of the 'Free Choice' Work/Family Reforms of France and Belgium. A Synthetic Control Analysis

Between the 1980s and the late 1990s, France and Belgium introduced two long-leave schemes and several measures to support childcare at home. Although this change was presented under the umbrella of the ‘free-choice-for-women’ rhetoric, it moved both countries towards a more familistic model. To evaluate the impact of this reform phase on female labour force participation, the present study employed the synthetic control method. This approach made it possible to contrast the evolution of the French and Belgian female labour force participation rates, observed in consequence of the implementation of the policies under investigation, with the corresponding evolution of the same rates reconstructed in the absence of such family programmes. The results of this exercise suggest that if France and Belgium had not undergone this policy treatment, their female labour market participation rates would have been higher than those actually measured. Key Practitioner Message: • Combining long-leave schemes with low incentives to support employment of a childminder obstructs female labour force participation.
Shielding Methodologies in the Presence of Power/Ground Noise

Design guidelines for shielding in the presence of power/ground (P/G) noise are presented in this paper. The effect of P/G noise on crosstalk is analyzed for different line lengths, line widths, and interconnect driver resistances. Considering the P/G noise, a shield line can degrade rather than enhance signal integrity due to increased P/G noise coupling on the victim line. A 2π RLC interconnect model is used to investigate the effects of both coupling capacitance and mutual inductance on the crosstalk noise. Physical spacing and shield insertion are compared in terms of the coupling noise on the victim line for several technology nodes. Boundary conditions are also provided to determine the effective range of spacing and shield insertion in the presence of P/G noise. Additionally, the effects of technology scaling on P/G noise and shielding efficiency are discussed, and related design tradeoffs are addressed.
IP lookups using multiway and multicolumn search

IP address lookup is becoming critical because of increasing routing table sizes, speed, and traffic in the Internet. Given a set S of prefixes and an IP address D, the IP address lookup problem is to find the longest matching prefix of D in set S. This paper shows how binary search can be adapted for solving the best-matching prefix problem. Next, we show how to improve the performance of any best-matching prefix scheme using an initial array indexed by the first X bits of the address. We then describe how to take advantage of cache line size to do a multiway search with six-way branching. Finally, we show how to extend the binary search solution and the multiway search solution for IPv6. For a database of N prefixes with address length W, naive binary search would take O(W*log N); we show how to reduce this to O(W+log N) using multiple-column binary search. Measurements using a practical (Mae-East) database of 38000 entries yield a worst-case lookup time of 490 ns, five times faster than the Patricia trie scheme used in BSD UNIX. Our scheme is attractive for IPv6 because of its small storage requirement (2N nodes) and speed (estimated worst case of 7 cache line reads per lookup).
Life Expectancy and Human Capital Investments: Evidence from Maternal Mortality Declines

Longer life expectancy should encourage human capital accumulation since a longer time horizon increases the value of investments that pay out over time. Previous work has been unable to determine the empirical importance of this life-expectancy effect due to the difficulty of isolating it from other effects of health on education. We examine a sudden drop in maternal mortality risk in Sri Lanka between 1946 and 1953 which creates a sharp increase in life expectancy for school-age girls without contemporaneous effects on health and which also allows for the use of boys as a control group. Using additional geographic variation we find that the 70% reduction in maternal mortality risk over the sample period increased female life expectancy at age 15 by 4.1% female literacy by 2.5% and female years of education by 4.0%. (authors)
A convenient synthetic approach to 8-vinyl-chlorophyll derivatives

Abstract Partial syntheses of two 8-vinyl-derivatives (3 and 6) of chlorin-e6 trimethyl ester 5 are reported; in certain organisms, 8-de-ethyl-8-vinylchlorophyll-a 3 has been proposed to be a biosynthetic precursor of the plant chlorophylls and of the bacteriochlorophylls.
On the accuracy of economic observations : do sub-Saharan trade statistics mean anything?

Matching exporters' freight on board (fob) trade statistics with the corresponding importers' cost, inventory and freight (cif) data, this paper studies the quality of official information on trade between 36 African countries. The author found the disparities in data so great as to make the official trade statistics almost useless for most empirical and policy studies. He concluded that: (a) statistics on matching exports and imports vary so much that the data cannot be used to assess the level of trade between African countries; (b) the data are probably equally useless for assessing the direction of trade since the countries that exporters report as the destination of trade often fail to report corresponding imports; (c) the data are inadequate for determining the composition of trade because countries report on different levels of detail; and (d) large, persistent, apparent differences in trends in intra-African trade may simply reflect different degrees of accuracy in country trade data. Finally, the fact that reported fob exports often exceed the corresponding reported imports suggests either that smuggling is widespread or that importers are intentionally underinvoicing because of high African tariffs or quotas.
Reduced-rank unscented Kalman filtering using Cholesky-based decomposition

In this paper, we use the Cholesky-based decomposition technique developed in [8] to construct the reduced-ensemble members. Specifically, we use the Cholesky decomposition to obtain a square root of the error covariance and select columns of the Cholesky factor to approximate CkPk. The retained columns of the Cholesky factor are used to construct the ensemble members. We compare the performance of the Cholesky-decomposition-based reduced-rank UKF and the SVD-based reduced-rank UKF on a linear advection model and a nonlinear system with chaotic dynamics.
Taking the Lie Out of Liar Loans: The Effect of Reduced Documentation on the Performance and Pricing of Alt-A and Subprime Mortgages

We present a simple theoretical model of adverse selection when lenders allow reduced documentation. The model shows how reduced documentation attracts both riskier borrowers and larger size loans....
On Relaxation Processes in Collisionless Mergers

We analyze N-body simulations of halo mergers to investigate the mechanisms responsible for driving mixing in phase-space and the evolution to dynamical equilibrium. We focus on mixing in energy and angular momentum and show that mixing occurs in step-like fashion following pericenter passages of the halos. This makes mixing during a merger unlike other well known mixing processes such as phase mixing and chaotic mixing whose rates scale with local dynamical time. We conclude that the mixing process that drives the system to equilibrium is primarily a response to energy and angular momentum redistribution that occurs due to impulsive tidal shocking and dynamical friction rather than a result of chaotic mixing in a changing potential. We also analyze the merger remnants to determine the degree of mixing at various radii by monitoring changes in radius, energy and angular momentum of particles. We confi rm previous findings that show that the majority of particles retain strong memory of their original kinetic energies and angular momenta but do experience changes in their potential energies owing to the tidal shock s they experience during pericenter passages. Finally, we show that a significant fraction of mass (≈ 40%) in the merger remnant lies outside its formal virial radius and that this matter is ejected roughly uniformly fro m all radii outside the inner regions. This highlights the fact that mass, in its standard virial definition, is not a dditive in mergers. We discuss the implications of these results for our understanding of relaxation in collis ionless dynamical systems. Subject headings: cosmology: theory — dark matter:halos — galaxies: relaxation — halos: structure — methods: numerical
THE TEMPERATURE OF INTERSTELLAR CLOUDS FROM TURBULENT HEATING

To evaluate the e!ect of turbulent heating in the thermal bal ance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the dimension of the most dissipative structures. By comparing the model with the probability distribution of the turbulent dissipation rate in a simulation of supersonic and super-Alfvenic turbulence, we find a best-fit value of d =1 .64. We apply this intermittency model to the computation of the mass-weighted probability distribution of the gas temperature of molecular clouds, high-mass star-forming cores, and cold di!use HI cl ouds. Our main results are: i) The mean gas temperature in molecular clouds can be explained as the e!ect of turbulent heating alone, while cosmic ray heating may dominate only in regions where the turbulent heating is low; ii) The mean gas temperature in high-mass star-forming cores with typical FWHM of ! 6 km s ! 1 (corresponding to a 1D rms velocity of 2.5 km s ! 1 ) may be completely controlled by turbulent heating, which predicts a mean value of approximately 36 K, two to three times larger than the mean gas temperature in the absence of turbulent heating; iii) The intermittency of the turbulent heating can generate enough hot regions in cold di!use HI clouds to explain the observed CH + abundance, if the rms velocity on a scale of 1 pc is at least 3 km s ! 1 , in agreement with previous results based on incompressible turbulence. Because of its importance in the thermal balance of molecular clouds and high-mass star-forming cores, the process of turbulent heating may be central in setting the characteristic stellar mass and in regulating molecular chemical reactions.
Network delay inference from additive metrics

We use computational phylogenetic techniques to solve a central problem in inferential network monitoring. More precisely, we design a novel algorithm for multicast-based delay inference, that is, the problem of reconstructing delay characteristics of a network from end-to-end delay measurements on network paths. Our inference algorithm is based on additive metric techniques used in phylogenetics. It runs in polynomial time and requires a sample of size only poly(log n). We also show how to recover the topology of the routing tree. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Atmospheric gas phase generation of singlet oxygen by homogeneous photosensitization

Abstract Singlet oxygen was generated in the gas phase at atmospheric pressure using homogeneous photosensitization and organic substances. The emission of O 2 ( 1 Δ g ) at 1.27 μm was observed.
Targeting college students on Facebook? How to stop wasting your money

Abstract While Facebook usage has seen explosive growth, scant research has explored returns on advertising dollars marketers invest in this emerging medium. Our two-stage study of 18- to 25-year-old college students suggests that many of the advertising dollars consumer goods firms spend on Facebook are likely wasted. This study highlights that, in addition to staying in touch with friends and relatives, Facebook users are primarily motivated by three desires: (1) to voyeuristically peer into others’ lives, (2) to create a distinctive identity for themselves, and (3) to act on their inner narcissistic tendencies. These motivations also make them poor prospects for advertisers, as users seem disinterested in Facebook ads and disengaged from marketers’ attempts to build brands. Herein, we discuss challenges for marketers, as well as opportunities for building brands and driving sales via Facebook.
The Impact of Inhomogeneous Reionization on the Satellite Galaxy Population of the Milky Way

We use the publicly available subhalo catalogs from the via Lactea II simulation along with a Gpc-scale N-body simulation to understand the impact of inhomogeneous reionization on the satellite galaxy population of the Milky Way. The large-volume simulation is combined with a model for reionization that allows us to predict the distribution of reionization times for Milky Way mass halos. Motivated by this distribution, we identify candidate satellite galaxies in the simulation by requiring that any subhalo must grow above a specified mass threshold before it is reionized; after this time the ph otoionizing background will suppress both the formation of stars and the accretion of gas. We show that varying the reionization time over the range expected for Milky Way mass halos can change the number of satellite galaxies by roughly two orders of magnitude. This conclusion is in contradiction with a number of studies in the literature, and we conclude that this is a result of inconsistent application of the results of Gnedi n (2000); subtle changes in the assumptions about how reionization affects star formation in small galaxies c an lead to large changes in the effect of changing the reionization time on the number of satellites. We compare our satellite galaxies to observations using both abundance matching and stellar population synthesis methods to assign luminosities to our subhalos and account for observational completeness effects. Additionally, if we assume that the mass threshold is set by the virial temperature Tvir = 8 � 10 3 K we find that our model accurately matches the vmax distribution, radial distribution, and luminosity function of observed Milky Way satellites for a reionization time zreion = 8 +3 -2 , assuming that the via Lactea II subhalo distribution is representative of the Milky Way. This results in the presence of 540 +100 -340 satellite galaxies. Subject headings: cosmology:theory — large-scale structure of universe — dark matter
Ideal Structure of Clifford Algebras

The structures of the ideals of Clifford algebras which can be both infinite dimensional and degenerate over the real numbers are investigated.
The Health Financing Transition: A Conceptual Framework and Empirical Evidence

Almost every country exhibits two important health financing trends: health spending per person rises and the share of out-of-pocket spending on health services declines. We describe these trends as a "health financing transition" to provide a conceptual framework for understanding health markets and public policy. Using data over 1995-2009 from 126 countries, we examine the various explanations for changes in health spending and its composition with regressions in levels and first differences. We estimate that the income elasticity of health spending is about 0.7, consistent with recent comparable studies. Our analysis also shows a significant trend in health spending - rising about 1 per cent annually - which is associated with a combination of changing technology and medical practices, cost pressures and institutions that finance and manage healthcare. The out-of-pocket share of total health spending is not related to income, but is influenced by a country's capacity to raise general revenues. These results support the existence of a health financing transition and characterize how public policy influences these trends.
Surface science and catalysis

Modern surface science studies have explored a large number of metal catalyst systems. Three classes of catalytic reactions can be identified: (1) those that occur over the metal surface; (2) reactions that take place on top of a strongly adsorbed overlayer and (3) reactions that occur on coadsorbate modified surfaces. Case histories for each class are presented. The first class of reactions is structure sensitive, and rough surfaces are needed for high reactivity. Ammonia synthesis, H 2 /D 2 exchange and complex hydrocarbon reaction studies all indicate the importance of high coordination sites that are present on atomically rough, open crystal surfaces, mostly in the second layer. A model is presented that correlates increased charge fluctuations at these sites with enhanced catalytic activity. The second class of reactions includes ethylene hydrogenation. It occurs via hydrogen transfer through a tenaciously held ethylidyne overlayer to weakly adsorbed ethylene molecules on top of this layer. Most catalytic reactions occur on coadsorbate modified metal surfaces. Sulphur, potassium, carbonaceous fragments and other metal constituents are employed most frequently as surface modifiers. These additives block sites and alter the bonding of the reactants, thereby changing the reaction paths. Their effects will be demonstrated through discussions of the CO/benzene, S/thiophene and CO/K interactions.
Control of discrete-time hybrid stochastic systems

A realistic stochastic control problem for hybrid systems with Markovian jump parameters can have switching parameters in both the state and the measurement equations. Furthermore, both the 'base' and jump states, in general, are not perfectly observed. There are only two existing controllers for this problem, both with complexity exponentially increasing with time. The authors present another control algorithm for stochastic systems with Markovian jump parameters. This algorithm is derived through the use of stochastic dynamic programming and is designed to be used for realistic stochastic control problems, i.e., with noisy state observations. This scheme has fixed computational requirements at each stage and a natural parallel implementation. Simulation results are used to compare the algorithm with previous schemes. >
Migration and the Tiebout-Tullock Hypothesis Revisited

This study investigates, using state-level data for the period 2000-2005, the Tiebout hypothesis (as extended by Tullock) of "voting with one's feet." This analysis differs from previous related studies not only in its adoption of more current migration and other data but also in other ways. First, unlike most earlier related studies, it includes a separate measure of the overall cost of living; second, it examines per pupil (rather than per capita) outlays on public primary and secondary education; and third, in addition to property taxes, it also focuses on per capita state income tax burdens. Inclusion of the last of these variables in the analysis is based on studies that have found the existence of a state income tax to have influenced migration patterns and other studies that have found higher state income tax levels to have resulted in reduced per capita income growth over time. Moreover, including both property tax burdens and income tax burdens broadens the scope of the hypothesis. Strong empirical support for the Tiebout-Tullock hypothesis (as interpreted here) is obtained for the study period.
Who Fears Competition from Informal Firms? Evidence from Latin America

This paper investigates who is most affected by informal competition and how regulation and enforcement affect the extent and nature of this competition. Using newly-collected enterprise data for 6,466 manufacturing formal firms across 14 countries in Latin America, the authors show that formal firms affected by head-to-head competition with informal firms largely resemble them. They are small credit constrained, underutilize their productive capacity, serve smaller customers, and are in markets with low entry costs. In countries where the government is effective and business regulations onerous, formal firms in industries characterized by low costs to entry feel the sting of informal competition more than in other business environments. Finally, the analysis finds that in an economy with relatively onerous tax regulations and a government that poorly enforces its tax code, the percentage of firms adversely affected by informal competition will be reduced from 38.8 to 37.7 percent when the government increases enforcement to cover all firms.
Robust control strategy for take-off performance in a windshear

A robust control strategy has been designed for an aircraft during take-off. The effects of different windshear intensities have been analysed for one- and two-dimensional models. The robust control is designed to tolerate windshear regardless of its variations. The only information the control utilizes is the upper-bound value of the allowable control magnitude.
Patient-tailored prioritization for a pediatric care decision support system through machine learning.

Objective Over 8 years, we have developed an innovative computer decision support system that improves appropriate delivery of pediatric screening and care. This system employs a guidelines evaluation engine using data from the electronic health record (EHR) and input from patients and caregivers. Because guideline recommendations typically exceed the scope of one visit, the engine uses a static prioritization scheme to select recommendations. Here we extend an earlier idea to create patient-tailored prioritization. Materials and methods We used Bayesian structure learning to build networks of association among previously collected data from our decision support system. Using area under the receiver-operating characteristic curve (AUC) as a measure of discriminability (a sine qua non for expected value calculations needed for prioritization), we performed a structural analysis of variables with high AUC on a test set. Our source data included 177 variables for 29 402 patients. Results The method produced a network model containing 78 screening questions and anticipatory guidance (107 variables total). Average AUC was 0.65, which is sufficient for prioritization depending on factors such as population prevalence. Structure analysis of seven highly predictive variables reveals both face-validity (related nodes are connected) and non-intuitive relationships. Discussion We demonstrate the ability of a Bayesian structure learning method to ‘phenotype the population’ seen in our primary care pediatric clinics. The resulting network can be used to produce patient-tailored posterior probabilities that can be used to prioritize content based on the patient's current circumstances. Conclusions This study demonstrates the feasibility of EHR-driven population phenotyping for patient-tailored prioritization of pediatric preventive care services.
Password exhaustion: predicting the end of password usefulness

Passwords are currently the dominant authentication mechanism in computing systems. However, users are unwilling or unable to retain passwords with a large amount of entropy. This reality is exacerbated by the increasing ability of systems to mount offline attacks. In this paper, we evaluate the degree to which the previous statements are true and attempt to ascertain the point at which passwords are no longer sufficient to securely mediate authentication. In order to demonstrate this, we develop an analytical model for computation to understand the time required to recover random passwords. Further, an empirical study suggests the situation is much worse. In fact, we found that past systems vulnerable to offline attacks will be obsolete in 5-15 years, and our study suggests that a large number of these systems are already obsolete. We conclude that we must discard or fundamentally change these systems, and to that effect, we suggest a number of ways to prevent offline attacks.
Lindblad resonance torques in relativistic discs - I. Basic equations

Lindblad resonances have been suggested as an important mechanism for angular momentum transport and heating in discs in binary black hole systems. We present the basic equations for the torque and heating rate for relativistic thin discs subjected to a perturbation. The Lindblad resonance torque is written explicitly in terms of metric perturbations for an equatorial disc in a general axisymmetric, time-stationary space–time with a plane of symmetry. We show that the resulting torque formula is gauge-invariant. Computations for the Schwarzschild and Kerr space–times are presented in the companion paper (Paper II).
2-aza-π-allylpalladium complexes for the synthesis of β-carboxyaspartic acid (asa) derivatives☆

Abstract Reaction of malonate anions with Schiff base acetates (3) in the presence of a palladium catalyst yields protected derivatives of β-carboxyaspartic acid (5).
Metal enrichment of the intergalactic medium

I demonstrate by means of high-resolution cosmological simulations, which include modelling of a two-phase interstellar medium, that the dominant mechanism for transporting heavy elements from protogalaxies into the intergalactic medium (IGM) is the merger mechanism as discovered by Gnedin & Ostriker. Direct ejection of the interstellar gas by supernovae plays only a minor role in transporting metals into the IGM: for a realistic cosmological scenario only a small fraction of all metals in the IGM is delivered by the supernova-driven winds, while most of the metals in the IGM are transported by the merger mechanism. As a result, the metallicity distribution in the IGM is highly inhomogeneous, in agreement with studies of the QSO metal absorption systems, and the predicted metallicity distribution of Lyman alpha absorbers as a function of their column density is in excellent agreement with the observational data.
Nominally Robust Model Predictive Control With State Constraints

In this paper, we present robust stability results for constrained discrete-time nonlinear systems using a finite-horizon model predictive control (MPC) algorithm for which we do not require the terminal cost to have any particular properties. We introduce a definition that attempts to characterize the robustness properties of the MPC optimization problem. We assume the systems under consideration satisfy this definition (for which we give sufficient conditions) and make two further assumptions. These are that the value function is bounded by a Kinfin function of a state measure (related to the distance from the state to some target set) and that this measure is detectable from the stage cost used in the MPC algorithm. We show that these assumptions lead to stability that is robust to sufficiently small disturbances. While in general the results are semiglobal and practical, when the detectability and upper bound assumptions are satisfied with linear Kinfin functions, the stability and robustness are either semiglobal or global (with respect to the feasible set). We discuss algorithms employing terminal inequality constraints and also provide a specific example of an algorithm that employs a terminal equality constraint.
Streaming Graph Partitioning in the Planted Partition Model

The sheer increase in the size of graph data has created a lot of interest into developing efficient distributed graph processing frameworks. Popular existing frameworks such as GraphLab and Pregel rely on balanced graph partitioning in order to minimize communication and achieve work balance. In this work we contribute to the recent research line of streaming graph partitioning [30], ;31], [34] which computes an approximately balanced k-partitioning of the vertex set of a graph using a single pass over the graph stream using degree-based criteria. This graph partitioning framework is well tailored to processing large-scale and dynamic graphs. In this work we introduce the use of higher length walks for streaming graph partitioning and show that their use incurs a minor computational cost which can significantly improve the quality of the graph partition. We perform an average case analysis of our algorithm using the planted partition model [7], [25]. We complement the recent results of Stanton [30] by showing that our proposed method recovers the true partition with high probability even when the gap of the model tends to zero as the size of the graph grows. Furthermore, among the wide number of choices for the length of the walks we show that the proposed length is optimal. Finally, we perform simulations which indicate that our asymptotic results hold even for small graph sizes.
Nonpositively curved 2-complexes with isolated flats

We introduce the class of nonpositively curved 2{complexes with the Isolated Flats Property. These 2{complexes are, in a sense, hyperbolic relative to their flats. More precisely, we show that several important properties of Gromovhyperbolic spaces hold \relative to flats" in nonpositively curved 2{complexes with the Isolated Flats Property. We introduce the Relatively Thin Triangle Property, which states roughly that the fat part of a geodesic triangle lies near a single flat. We also introduce the Relative Fellow Traveller Property, which states that pairs of quasigeodesics with common endpoints fellow travel relative to flats, in a suitable sense. The main result of this paper states that in the setting of CAT(0) 2{complexes, the Isolated Flats Property is equivalent to the Relatively Thin Triangle Property and is also equivalent to the Relative Fellow Traveller Property.
Sharp probability estimates for random walks with barriers

We give sharp, uniform estimates for the probability that a random walk of n steps on the reals avoids a half-line [y,∞) given that it ends at the point x. The estimates hold for general continuous or lattice distributions provided the fourth moment is finite.
Convergence in Local Government Spending: Evidence from Wisconsin

A substantial body of theoretical and empirical evidence demonstrates that interregional competition for factors of production leads to convergence of per capita output. Is there an analogous process that leads to convergence of public sector activity? Skidmore, et al (2004) develop a model that is consistent with the macroeconomic growth literature, which predicts convergence in government spending. Based on this framework, we test for convergence in government spending using detailed data from Wisconsin for a variety of municipal government expenditure categories over the 1989/90-1999/2000 period. Our empirical investigation provides compelling evidence of convergence in capita government spending for all the expenditure categories we study. This work adds to the growing body of evidence demonstrating the existence of underlying dynamic forces that determine growth of government.
The Newer Fluoroquinolones

Clinicians have enthusiastically used fluoroquinolones owing to their good safety profile and wide range of indications. This article reviews fluoroquinolone pharmacology, pharmacodynamic principles, and fluoroquinolone resistance mechanisms, highlighting recent trends in the epidemiology of fluoroquinolone resistance among gram-negative organisms and Streptococcus pneumonia. Important fluoroquinolone safety concerns are discussed, along with indications for the most commonly used fluoroquinolones--ciprofloxacin, levofloxacin, and moxifloxacin.
Sociology: A Lost Connection in Social Psychology

For the first half of the 20th century, sociology was one of the closest allies of social psychology. Over the past four decades, however, the connection with sociology has weakened, whereas new connections with neighboring disciplines (e.g., biology, economics, political science) have formed. Along the way, the sociological perspective has been largely lost in mainstream social psychology in the United States. Most social psychologists today are not concerned with collective phenomena and do not investigate social structural factors (e.g., residential mobility, socioeconomic status, dominant religion, political systems). Even when the social structural factors are included in the analysis, psychologists typically treat them as individual difference variables. Sociologist C. Wright Mills famously promoted sociological imagination, or the ability to see distal yet important social forces operating in a larger societal context. By comparing sociological perspectives to psychological perspectives, this article highlights the insights that the sociological perspective and sociological imagination can bring to social psychology.
Synthesis of lipophilic lariat ethers with pendant N‐(X)sulfonyl carboxamide groups

Synthetic routes to sixteen lipophilic lariat ether N-(X)sulfonyl carboxamides with X = trifluoromethyl, methyl, phenyl, and p-nitrophenyl are described. For this new family of proton-ionizable lariat ethers in which the acidity can be ‘tuned’ by X group variation, the ring size is systematically varied from 12-crown-4 to 14-crown-4 to 15-crown-5 to 18-crown-6.
Recent advances in homogeneous nickel catalysis

Tremendous advances have been made in nickel catalysis over the past decade. Several key properties of nickel, such as facile oxidative addition and ready access to multiple oxidation states, have allowed the development of a broad range of innovative reactions. In recent years, these properties have been increasingly understood and used to perform transformations long considered exceptionally challenging. Here we discuss some of the most recent and significant developments in homogeneous nickel catalysis, with an emphasis on both synthetic outcome and mechanism.
The theory of financial intermediation

Abstract Traditional theories of intermediation are based on transaction costs and asymmetric information. They are designed to account for institutions which take deposits or issue insurance policies and channel funds to firms. However, in recent decades there have been significant changes. Although transaction costs and asymmetric information have declined, intermediation has increased. New markets for financial futures and options are mainly markets for intermediaries rather than individuals or firms. These changes are difficult to reconcile with the traditional theories. We discuss the role of intermediation in this new context stressing risk trading and participation costs.
Young Children's Competency to Take the Oath: Effects of Task, Maltreatment, and Age.

This study examined maltreated and non-maltreated children’s (N = 183) emerging understanding of “truth” and “lie,” terms about which they are quizzed to qualify as competent to testify. Four- to six-year-old children were asked to accept or reject true and false (T/F) statements, label T/F statements as the “truth” or “a lie,” label T/F statements as “good” or “bad,” and label “truth” and “lie” as “good” or “bad.” The youngest children were at ceiling in accepting/rejecting T/F statements. The labeling tasks revealed improvement with age and children performed similarly across the tasks. Most children were better able to evaluate “truth” than “lie.” Maltreated children exhibited somewhat different response patterns, suggesting greater sensitivity to the immorality of lying.
Multidimensional spectroscopy with entangled light: loop vs ladder delay scanning protocols

Multidimensional optical signals are commonly recorded by varying the delays between time ordered pulses. These control the evolution of the density matrix and are described by ladder diagrams. We propose a new non-time-ordered protocol based on following the time evolution of the wavefunction and described by loop diagrams. The time variables in this protocol allow one to observe different types of resonances and reveal information about intraband dephasing not readily available by time ordered techniques. The time variables involved in this protocol become coupled when using entangled light, which provides high selectivity and background free measurement of the various resonances. Entangled light can resolve certain states even when strong background due to fast dephasing suppresses the resonant features when probed by classical light.
On Equivalence of Infinitary Formulas under the Stable Model Semantics

Propositional formulas that are equivalent in intuitionistic logic, or in its extension known as the logic of here-and-there, have the same stable models. We extend this theorem to propositional formulas with infinitely long conjunctions and disjunctions and show how to apply this generalization to proving properties of aggregates in answer set programming.
Microenvironmental Regulation of the Sinusoidal Endothelial Cell Phenotype In Vitro

Liver Sinusoidal Endothelial Cells (LSEC) differ, both structurally and functionally, from endothelial cells (EC) lining blood vessels of other tissues. For example, in contrast to other EC, LSEC posses fenestrations, have low detectable levels of PECAM-1 expression, and in rat tissue, they distinctively express a cell surface marker recognized by the SE-1 antibody. These unique phenotypic characteristics seen in hepatic tissue are lost over time upon culture in vitro; therefore, this study sought to systematically examine the effects of microenvironmental stimuli, namely, extracellular matrix (ECM) and neighboring cells, on the LSEC phenotype in vitro. In probing the role of the underlying extracellular matrix, we identified collagen I and collagen III as well as mixtures of collagen I/collagen IV/fibronectin as having a positive effect on LSEC survival. Furthermore, using a stable hepatocellular model (hepatocyte-fibroblast) we were able to prolong the expression of both SE-1 and phenotypic functions of LSEC such as Factor VIII activity in cocultured LSECs through the production of short-range paracrine signals. In the course of these experiments, we identified the antigen recognized by SE-1 as CD32b. Collectively, this study has identified several microenvironmental regulators of liver sinusoidal endothelial cells that prolong their phenotypic functions for up to 2 weeks in culture, enabling the development of better in vitro models of liver physiology and disease.
Complexification of gauge theories

For the case of a first-class constrained system with equivariant momentum map, we study the conditions under which the double process of reducing to the constraint surface and dividing out by the group of gauge transformations G is equivalent to the single process of dividing out the initial phase space by the complexification Cc of G. For the particular case of a phase space action that is the lift of a configuration space action, conditions are found under which, in finite dimensions, the physical phase space of a gauge system with first-class constraints is diffeomorphic to a manifold imbedded in the physical configuration space of the complexified gauge system. Similar conditions are shown to hold for the infinite-dimensional example of Yang-Mills theories. As a physical application we discuss the adequateness of using holomorphic Wilson loop variables as (generalized) global coordinates on the physical phase space of Yang-Mills theory.
Integration of multiple signaling pathway activities resolves K-RAS/N-RAS mutation paradox in colon epithelial cell response to inflammatory cytokine stimulation

Colon tumors frequently harbor mutation in K-RAS and/or N-RAS, members of a GTPase family operating as a central hub for multiple key signaling pathways. While these proteins are strongly homologous, they exhibit diverse downstream effects on cell behavior. Utilizing an isogenic panel of human colon carcinoma cells bearing oncogenic mutations in K-RAS and/or N-RAS, we observed that K-RAS and double mutants similarly yield elevated apoptosis in response to treatment with TNFα compared to N-RAS mutants. Regardless, and in surprising contrast, key phospho-protein signals were more similar between N-RAS and dual mutants. This apparent contradiction could not be explained by any of the key signals individually, but a multi-pathway model constructed from the single-mutant cell line data was able to predict the behavior of the dual-mutant cell line. This success arises from a quantitative integration of multiple pro-apoptotic (pIκBα, pERK2) and pro-survival (pJNK, pHSP27) signals in manner not easily discerned from intuitive inspection.
Status of the Stanford gravitational wave experiment

Abstract The low temperature gravitational radiation antenna under development at Stanford has now been operating for about 1 year. During this time the system has been completely evaluated and 1250 hours has been spent taking data. The antenna noise temperature has been measured at 10 mK and the sensitivity in 10−1 GPU.
Finding optimal bayesian networks

In this paper, we derive optimality results for greedy Bayesian-network search algorithms that perform single-edge modifications at each step and use asymptotically consistent scoring criteria. Our results extend those of Meek (1997) and Chickering (2002), who demonstrate that in the limit of large datasets, if the generative distribution is perfect with respect to a DAG defined over the observable variables, such search algorithms will identify this optimal (i.e. generative) DAG model. We relax their assumption about the generative distribution, and assume only that this distribution satisfies the composition property over the observable variables, which is a more realistic assumption for real domains. Under this assumption, we guarantee that the search algorithms identify an inclusion-optimal model; that is, a model that (1) contains the generative distribution and (2) has no sub-model that contains this distribution. In addition, we show that the composition property is guaranteed to hold whenever the dependence relationships in the generative distribution can be characterized by paths between singleton elements in some generative graphical model (e.g. a DAG, a chain graph, or a Markov network) even when the generative model includes unobserved variables, and even when the observed data is subject to selection bias.
[Mn12O12(O2CMe)12(NO3)4(H2O)4]: facile synthesis of a new type of Mn12 complex

The title dodeca­nuclear Mn complex, namely dodeca-μ2-acetato-κ24O:O′-tetra­aqua­tetra-μ2-nitrato-κ8O:O′-tetra-μ4-oxido-octa-μ3-oxido-tetra­manganese(IV)octa­manganese(III) nitro­methane tetra­solvate, [Mn12(CH3COO)12(NO3)4O12(H2O)4]·4CH3NO2, was synthesized by the reaction of Mn2+ and Ce4+ sources in nitro­methane with an excess of acetic acid. This compound is distinct from the previously known single-mol­ecule magnet [Mn12O12(O2CMe)16(H2O)4], synthesized by Lis [Acta Cryst. (1980), B36, 2042–2044]. It is the first Mn12-type mol­ecule containing nitrate ligands to be directly synthesized without the use of a preformed cluster. Additionally, this mol­ecule is distinct from all other known Mn12 complexes due to inter­molecular hydrogen bonds between the nitrate and water ligands, which give rise to a three-dimensional network. The complex is compared to other known Mn12 mol­ecules in terms of its structural parameters and symmetry.