cssi/SciSciGPT-SciSciNet huggingface dataset:
The impact of capital requirements on banks’ cost of intermediation and performance: The case of Egypt☆

Abstract In 1991, the Central Bank of Egypt increased the minimum capital requirements for the banking industry vis-a-vis risk-weighted assets to 8%, along the lines proposed by the Basel Committee on Banking Supervision. In this paper, we investigate the effects of capital regulations on cost of intermediation and profitability. Higher capital adequacy increases the interest of shareholders in managing banks’ portfolios. The result is a higher cost of intermediation and profitability. A number of factors have increased the cost of intermediation in the post-capital regulation period: higher capital-to-assets ratios, an increase in management efficiency, an improvement of liquidity and a reduction in inflation. The reduction in output growth countered these effects. A number of factors contributed positively to banks’ profitability in the post-regulation period: higher capital requirements, the reduction in implicit cost, and the increase in management efficiency. The reduction in economic activity had opposite effects on banks’ profitability. Overall, the results support the Central Bank's efforts to enforce capital regulations to improve the performance of the banking sector in Egypt.
An mndo study of structures and stabilities of representative 1-chloro-1-alkenes and of their beryllium hydride derivatives

Abstract MNDO calculations were applied in order to investigate the inherent stabilities of 1-chloro-1-alkenes and their beryllium hydride derivatives. The calculated geometries and atomic charges are compared with applicable experimental findings. The calculations also explain the observed relative stabilities of metallated 1,2-dichloroalkenes. The two factors which increase the stabilization of compounds in this series are: the absence of a chlorine substituent trans to the metal and the degree of polarization of the C-Cl bond being broken.
Synthetic Paths to the Heaviest Elements

The cross section for producing a heavy reaction product, σEVR, can be represented by the equation where σcapture(Ec.m.,J) is the capture cross section at center of mass energy Ec.m. and spin J. PCN is the probability that the projectile-target system will evolve from the contact configuration inside the fission saddle point to form a completely fused system rather than re-separating (quasifission, fast fission). Wsur is the probability that the completely fused system will de-excite by neutron emission rather than fission. I discuss results of experiments that characterize these quantities in heavy element synthesis reactions. I also discuss the possibilities of synthesizing heavy nuclei using damped collisions and reactions using radioactive beams.
Decoherence-induced geometric phase in a multilevel atomic system

We consider the STIRAP process in a three-level atom. Viewed as a closed system, no geometric phase is acquired. But in the presence of spontaneous emission and/or collisional relaxation we numerically show that a non-vanishing, purely real, geometric phase is acquired during STIRAP, whose magnitude grows with the decay rates. We speculate that rather than viewing this decoherence-induced geometric phase as a nuisance, it can be considered an example of 'beneficial decoherence': the environment provides a mechanism for the generation of geometric phases which would otherwise require an extra experimental control knob.
Magnetic reconnection in plasma under inertial confinement fusion conditions driven by heat flux effects in OHM'S law

Summary form only given. In the interaction of high power laser beams with solid density plasma, there are a number of generating mechanisms that result in very strong magnetic fields. Such fields can subsequently inhibit or redirect energy transport. Here, we present 2D numerical modeling of near critical density plasma using a fully implicit Vlasov-Fokker-Planck code, IMPACTA, which includes self-consistent magnetic fields as well as anisotropic electron pressure terms in the expansion of the distribution function. Magnetic field generation and advection by different mechanisms are studied in the context of heating by multiple laser spots, between which reconnection of magnetic field lines may occur. In particular, we compare the relative importance of Hall, resistivity, and heat flux effects in the magnetic field dynamics of MG strength, oppositely aligned magnetic fields interacting in a plasma under conditions relevant to the wall of a hohlraum. We show that reconnection does indeed occur and furthermore, under such conditions, the reconnection rate is moderated by the heat flow rather than the Alfvenic flows in the system.
Publication history of von Staudt’s Geometrie der Lage

Author(s): Hartshorne, Robin | Abstract: From a census of forty copies, we can distinguish three different editions of von Staudt's Geometrie der Lage: the first of 1847 and two undated ones from the 1870's.
The Star Product on the Fuzzy Supersphere

The fuzzy supersphere S (2,2) F is a finite-dimensional matrix approximation to the supersphere S (2,2) incorporating supersymmetry exactly. Here the ⋆-product of functions on S (2,2) F is obtained by utilizing the OSp(2,1) coherent states. We check its graded commutative limit to S (2,2) and extend it to fuzzy versions of sections of bundles using the methods of [1]. A brief discussion of the geometric structure of our ⋆-product completes our work.
Uniform Correlation Mixture of Bivariate Normal Distributions and Hypercubically Contoured Densities That Are Marginally Normal

The bivariate normal density with unit variance and correlation ρ is well known. We show that by integrating out ρ, the result is a function of the maximum norm. The Bayesian interpretation of this result is that if we put a uniform prior over ρ, then the marginal bivariate density depends only on the maximal magnitude of the variables. The square-shaped isodensity contour of this resulting marginal bivariate density can also be regarded as the equally weighted mixture of bivariate normal distributions over all possible correlation coefficients. This density links to the Khintchine mixture method of generating random variables. We use this method to construct the higher dimensional generalizations of this distribution. We further show that for each dimension, there is a unique multivariate density that is a differentiable function of the maximum norm and is marginally normal, and the bivariate density from the integral over ρ is its special case in two dimensions.
Simulation-based estimation of dynamic models with continuous equilibrium solutions

Abstract This paper presents several results on consistency properties of simulation-based estimators for a general class of dynamic models with continuous laws of motion. The consistency of these estimators follows from a uniform convergence property of the model’s sample paths over the vector of parameters. This convergence property is established under either contractivity or monotonicity conditions on the dynamics of the system.
Roundness Properties Of Ultrametric Spaces

Motivated by a classical theorem of Schoenberg, we prove that an n + 1 point finite metric space has strict 2-negative type if and only if it can be isometrically embedded in the Euclidean space consists of all finite metric spaces of strict 2-negative type. We also note that it is possible to construct an additive metric space whose generalized roundness is exactly ℘ for each ℘ ∈ [1, ∞].
Synthesis of the C59N+ carbocation. A monomeric azafullerene isoelectronic to C60.

A heterofullerene isoelectronic to C60 is reported. The azafullerenium cation C59N+ can be isolated in good yield as a carborane salt via the two-electron oxidation of the C−C bond of (C59N)2 dimer. [C59N][Ag(CB11H6Cl6)2] has been characterized by electronic, IR, Raman, and 13C NMR spectroscopies, MALDI spectrometry, DFT calculations, and X-ray crystallography.
Political Influence of Exporting and Import-Competing Firms: Evidence from Eastern European and Central Asian Countries

Summary Theoretical studies have emphasized the role firms play in shaping laws and regulations through political activities. This paper examines whether import-competing firms and exporting firms possess differing levels of political influence by using firm-level data from 27 Eastern European and Central Asian countries. To control for endogeneity, we estimate a multivariate probit model using a simulated maximum-likelihood algorithm. We find that exporting firms have stronger political influence than import-competing firms, indicating that more free trade policies are the likely outcome of political-rent seeking in these countries. The results have significant implications for countries’ economic growth and development.
Extragalactic Point Source Search in Five-Year WMAP 41, 61, and 94 Ghz Maps

We present the results of an extragalactic point source search using the five-year Wilkinson Microwave Anisotropy Probe (WMAP) 41, 61, and 94 GHz (Q, V, and W bands) temperature maps. This work is an extension of our designing and applying a cosmic microwave background (CMB)-free technique to extract point sources in the WMAP maps. Specifically, we have formed an internal linear combination map of the three-band maps, with the weights chosen to remove the CMB anisotropy signal as well as to favor the selection of flat-spectrum sources. We have also constructed a filter to recover the true point source flux distribution on the sky. A total of 381 sources are found in our study at the >5σ level outside the WMAP point source detection mask, among which 89 are new (i.e., not present in the WMAP catalogs). Source fluxes have been calculated and corrected for the Eddington bias. We have solidly identified 367 (96.3%) of our sources, the 1σ positional uncertainty of which is 2'. The 14 unidentified sources could be either extended radio structure or obscured by Galactic emission. We have also applied the same detection approach to simulated maps, which yielded 364 ± 21 detections on average. The recovered source distribution N(>S) agrees well with the simulation input, which proves the reliability of this method.
Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak

The baryon acoustic oscillations are a promising route to the precision measure of the cosmological distance scale and hence the measurement of the time evolution of dark energy. We show that the nonlinear degradation of the acoustic signature in the correlations of low-redshift galaxies is a correctable process. By suitable reconstruction of the linear density field, one can sharpen the acoustic peak in the correlation function or, equivalently, restore the higher harmonics of the oscillations in the power spectrum. With this, one can achieve better measurements of the acoustic scale for a given survey volume. Reconstruction is particularly effective at low redshift, where the nonlinearities are worse but where the dark energy density is highest. At z = 0.3, we find that one can reduce the sample variance error bar on the acoustic scale by at least a factor of 2 and in principle by nearly a factor of 4. We discuss the significant implications our results have for the design of galaxy surveys aimed at measuring the distance scale through the acoustic peak.
Minimizing the number of late tasks with error constraint

Abstract The problem of minimizing the number of late tasks in the imprecise computation model is considered. Each task consists of two subtasks, mandatory and optional. A task is said to be on-time if its mandatory part is completed by its deadline; otherwise, it is said to be late. An on-time task incurs an error if its optional part is not completed by its deadline, and the error is simply the execution time of the unfinished portion. In this paper we consider the problem of finding a preemptive schedule for a set of tasks on p≥1 identical processors, such that the number of on-time tasks is maximized (or equivalently, the number of late tasks is minimized), and the total error of the on-time tasks is no more than a given threshold K. Such a schedule is called an optimal schedule. It is shown that the problem of finding an optimal schedule is NP-hard for each fixed p≥1, even if all tasks have the same ready time and the same deadline. Motivated by the complexity of the problem, we consider the case of a single processor and a set of tasks with oppositely ordered ready times and deadlines. We give a pseudo-polynomial time algorithm and a fast heuristic for this special case. The heuristic is shown to have an asymptotic worst-case ratio of 3. Finally, we give a polynomial time algorithm for a set of tasks with oppositely ordered ready times and deadlines, and similarly ordered mandatory execution times and total execution times.
Real-Time Optimal Guidance for Orbital Maneuvering

A new formulation for soft-constraint trajectory optimization is presented as a real-time optimal feedback guidance method for multiburn orbital maneuvers. Control is always chosen to minimize burn time plus a quadratic penalty for end condition errors, weighted so that early in the mission (when controllability is greatest) terminal errors are held negligible. Eventually, as controllability diminishes, the method partially relaxes but effectively still compensates perturbations in whatever subspace remains controllable. Although the soft-constraint concept is well-known in optimal control, the present formulation is novel in addressing the loss of controllability inherent in multiple burn orbital maneuvers. Moreover the necessary conditions usually obtained from a Bolza formulation are modified in this case so that the fully hard constraint formulation is a numerically well behaved subcase. As a result convergence properties have been greatly improved.
The kinetics of grain boundary nucleated reactions

Abstract Rate laws are derived for transformations in which the new phase nucleates on grain boundary surface, grain edges, or grain corners, and in which the new phase grows with constant radial velocity. Time-dependent and time-independent nucleation rates are treated. At high nucleation rates (relative to growth rates and grain sizes) the rate law assumes a form independent of the nucleation rate, and the half-time of the transformation becomes approximately 0.1 D G , where D is the grain diameter and G the radial growth velocity, independently of which sites are responsible for nucleation. At low nucleation rates the rate law approaches that given by randomly distributed nucleation sites. The conditions which determine which type of site will produce the most nuclei, and hence determine the form of the rate law, are discussed.
Spectrum sharing between wireless networks

We consider the problem of two wireless networks operating on the same (presumably unlicensed) frequency band. Pairs within a given network cooperate to schedule transmissions, but between networks there is competition for spectrum. To make the problem tractable, we assume transmissions are scheduled according to a random access protocol where each network chooses an access probability for its users. A game between the two networks is defined. We characterize the Nash Equilibrium behavior of the system. Three regimes are identified: one in which both networks simultaneously schedule all transmissions, one in which the denser network schedules all transmissions and the sparser only schedules a fraction, and one in which both networks schedule only a fraction of their transmissions. The regime of operation depends on the path loss exponent α, the latter regime being desirable but attainable only for α > 4. This suggests that in certain environments, rival wireless networks may end up naturally cooperating. To substantiate our analytical results, we simulate a system where networks iteratively optimize their access probabilities in a greedy manner. We also discuss a distributed scheduling protocol that employs carrier sensing and demonstrate via simulations that again a near cooperative equilibrium exists for sufficiently large α.
Low-energy collective modes, Ginzburg-Landau theory, and pseudogap behavior in superconductors with long-range pairing interactions

We study the superconducting instability in systems with long- but finite-ranged attractive pairing interactions. We show that such long-ranged superconductors exhibit a class of fluctuations in which the internal structure of the Cooper pair wave function is soft, and thus lead to ``pseudogap'' behavior in which the actual transition temperature is greatly depressed from its mean-field value. These fluctuations are not phase fluctuations of the standard superconducting order parameter, and lead to a highly unusual Ginzburg-Landau description. We suggest that the crossover between the BCS limit of a short-ranged attraction and our problem is of interest in the context of superconductivity in the underdoped cuprates.
Mayer-Vietoris formula for determinants of elliptic operators of Laplace-Beltrami type (after Burghelea, Friedlander and Kappeler)

Abstract The purpose of this note is to provide a short cut presentation of a Mayer-Vietoris formula due to Burghelea-Friedlander-Kappeler for the regularized determinant in the case of elliptic operators of Laplace-Beltrami type in the form typically needed in applications to torsion.
Occipital plagiocephaly: a critical review of the literature.

Object. The literature on occipital plagiocephaly (OP) was critically reviewed to determine the feasibility of establishing treatment recommendations. Methods. Using standard computerized search techniques, medical literature databases containing peer-review articles dating from 1966 were queried for key words related to OP. The titles of all articles were scanned for relevance, and copies of potentially relevant articles published in English were reviewed. Articles in which treatment was discussed were categorized according to their weight of evidence as Class I (prospective randomized controlled trials), Class II (clinical studies in which data are collected prospectively or retrospective analyses based on clearly reliable data), and Class III (most studies based on retrospectively collected data) to evaluate their contribution to developing a consensus on the treatment of OP. Of the 4308 articles identified, all but 89 were excluded. Based on the review of these articles, the actual incidence of OP is ...
Taxes and labor supply

Over 75% of Federal tax revenue is raised through the income tax and FICA taxes. The potential effects on labor supply and economic welfare are important because of the large and increasing reliance on direct taxation. Over the past few years significant legislative changes have occurred with respect to taxation of labor: the 25% tax cuts,indexation,the tax credit for working spouses, and likely increases in FICA taxation.I reviewr ecent econometric work which measures the effect of taxes on labor supply and which analyzes the likely effects of tax law changes on labor supply and economic welfare.Sections 1 and 2 develop the theory and econometric techniques for models of labor supply with taxes. Section 3 discusses the various tax systemsin the U.S. In Section 4, I present empirical estimates for husbands'and wives' labor supply functions. The economic cost of the tax system is also estimated. In Section 5 the individual questionnaire data for high income individuals is reviewed. Lastly, in Section 6 evidence from the negative income tax experiments and for social security beneficiaries is considered. These latter groups face extremely high marginal tax rates so that evidence beyond that contained in other surveys of labor supplyis provided.
Current-Induced Effects in Nanoscale Conductors

We present an overview of current-induced effects in nanoscale conductors with emphasis on their description at the atomic level. In particular, we discuss steady-state current fluctuations, current-induced forces, inelastic scattering and local heating. All of these properties are calculated in terms of single-particle wave-functions computed using a scattering approach within the static density-functional theory of many-electron systems. Examples of current-induced effects in atomic and molecular wires will be given and comparison with experimental results will be provided when available.
A Leverage-based Model of Speculative Bubbles

This paper provides a framework for exploring the role of various policies in giving rise to or ruling out the possibility of speculative bubbles. As in previous work by Allen and Gorton (1993) and Allen and Gale (2000), a bubble can occur in my model because traders are assumed to purchase assets with borrowed funds. My model adds to this literature by allowing creditors and traders to enter into a general class of contracts, as well as allowing speculators to trade strategically. The paper examines whether it is possible to rule out speculative bubbles through restrictions on the types of contracts speculators can use, down-payment requirements, and increases in short-term rates, respectively.
Chemoselective halogenation of 2-hydroperfluoroalkyl aldehydes

Abstract 2-Hydroaldehydes, R f CH(R)CHO, where R f = CF 3 , C 2 F 5 , n -C 3 F 7 and R = CF 3 , C 2 F 5 , n -C 3 F 7 , Ph, H, were prepared via acid hydrolysis of the corresponding vinyl ethers, R f C(R) = CHOCH 3 , which can be readily prepared by reaction of [ Ph 3 P + C ¯ HOCH 3 ] with the corresponding ketone. The 2-hydroaldehydes can be chemoselectively converted to the acyl halide, R f CH(R)C(O)X (X = Cl, Br), via free-radical halogenation. The perfluoroalkyl group deactivates the 2-position toward radical abstraction of the 2-hydrogen, and halogenation occurs exclusively at the formyl hydrogen. However, halogenations of the 2-hydroaldehydes in glacial acetic acid chemoselectively gives the 2-haloaldehydes, R f CX(R)CHO, X = Cl, Br. Hydrolysis of the 2-hydroperfluoroacyl halides provides a useful route to 2-hydroperfluoroalkyl branched carboxylic acids, useful ketene precursors. This route avoids the use of toxic fluoroolefins, such as perfluoroisobutylene.
Syntactic probabilities affect pronunciation variation in spontaneous speech

Speakers frequently have a choice among multiple ways of expressing one and the same thought. When choosing between syntactic constructions for expressing a given meaning, speakers are sensitive to probabilistic tendencies for syntactic, semantic or contextual properties of an utterance to favor one construction or another. Taken together, such tendencies may align to make one construction overwhelmingly more probable, marginally more probable, or no more probable than another. Here, we present evidence that acoustic features of spontaneous speech reflect these probabilities: when speakers choose a less probable construction, they are more likely to be disfluent, and their fluent words are likely to have a relatively longer duration. Conversely, words in more probable constructions are shorter and
How Much of Cross-Country Income Variation is Explained by Health?

We use development accounting techniques to assess the contribution of health to differences in income per capita among countries. Rather than rely on regressions in aggregate data, we build up estimates of the effect of health starting from microeconomic data. We examine both a particular condition, anemia, and a proxy for general health, the adult survival rate. We find that differences in anemia explain 1.3 percent of the log variance of income per capita, and that differences in adult survival explain 19 percent of the log variance of income per capita. The latter figure is almost one third of the variation in output that is left unexplained by other In this paper, we examine quantitatively the effect of health on income per capita as well as the contribution of health to differences in income among countries. Understanding the effect of health on income is important for two reasons. First, if health does have a large effect on income per capita, then this would be an important additional benefit of health improvement (beyond the direct effect on the quality of life) that should be taken into account when tallying up the costs and benefits of health interventions in developing countries. Second, for economists trying to understand differences in income per capita among countries, a proper accounting of the role of health is essential both for telling the complete story of economic growth and for evaluating the role of other factors that affect income. Specifically, accounting for health differences will reduce the size of the unexplained residual variance in income among countries that is currently attributed to productivity. In this paper we examine both a single condition, anemia, and a measure of overall health, the adult survival rate. Figure 1 shows the relationship between income per capita and our two health measures. Both measures are strongly correlated with income, but using this data to infer the effect of health on economic outcomes presents two problems: first, health is itself endogenous.
Understanding the reverse time migration backscattering: noise or signal?

Reverse time migration backscattered events are produced by the cross-correlation between waves reflected from sharp interfaces (e.g., salt bodies). These events, along with head waves and diving waves, produce the so-called reverse time migration artefacts, which are visible as low wavenumber energy on migrated images. Commonly, these events are seen as a drawback for the reverse time migration method because they obstruct the image of the geologic structure, which is the real objective for the process. In this paper, we perform numeric and theoretical analysis to understand the reverse time migration backscattering energy in conventional and extended images. We show that the reverse time migration backscattering contains a measure of the synchronization and focusing information between the source and receiver wavefields. We show that this synchronization and focusing information is sensitive to velocity errors; this implies that a correct velocity model produces reverse time migration backscattering with maximum energy. Therefore, before filtering the reverse time migration backscattered energy, we should try to obtain a model that maximizes it.
Frame theory for binary vector spaces

We develop the theory of frames and Parseval frames for finite-dimensional vector spaces over the binary numbers. This includes characterizations which are similar to frames and Parseval frames for real or complex Hilbert spaces, and the discussion of conceptual differences caused by the lack of a proper inner product on binary vector spaces. We also define switching equivalence for binary frames, and list all equivalence classes of binary Parseval frames in lowest dimensions, excluding cases of trivial redundancy.
PERPETUAL CANCELLABLE AMERICAN CALL OPTION

This paper examines the valuation of a generalized American-style option known as a game-style call option in an infinite time horizon setting. The specifications of this contract allow the writer to terminate the call option at any point in time for a fixed penalty amount paid directly to the holder. Valuation of a perpetual game-style put optionwasaddressedbyKyprianou(2004)inaBlack-Scholessettingonanondividend paying asset. Here, we undertake a similar analysis for the perpetual call option in the presence of dividends and find qualitatively different explicit representations for the value function depending on the relationship between the interest rate and dividend yield. Specifically, we find that the value function is not convex whenr > d. Numerical results show the impact this phenomenon has upon the vega of the option.
On the Classification of Type II Codes of Length 24

We give a new, purely coding-theoretic proof of Koch's criterion on the tetrad systems of Type II codes of length 24 using the theory of harmonic weight enumerators. This approach is inspired by Venkov's approach to the classification of the root systems of Type II lattices in $\mathbb{R}^{24}$ and gives a new instance of the analogy between lattices and codes.
Planning and Learning in Environments with Delayed Feedback

This work considers the problems of planning and learning in environments with constant observation and reward delays. We provide a hardness result for the general planning problem and positive results for several special cases with deterministic or otherwise constrained dynamics. We present an algorithm, Model Based Simulation, for planning in such environments and use model-based reinforcement learning to extend this approach to the learning setting in both finite and continuous environments. Empirical comparisons show this algorithm holds significant advantages over others for decision making in delayed environments.
Stationarity of Asian-Pacific real exchange rates

Abstract Using a nonlinear unit root test, we reject the null hypothesis of nonstationarity for most of the Asian-Pacific real exchange rates, but not for the Japanese yen based rates. There is more evidence for level stationarity in the Singapore dollar based rates than in other currency based rates.
Hierarchical computation of the resource allocation problem

Some recent research on information processing in organizations has treated the agents who process information as endogenous. This paper discusses a sample of models in this area, which differ in their methodology but are unified by the fact that they study the resource allocation problem. Computational constraints are related to the structure and returns to scale of hierarchies.
Modeling single- and multiple-electron resonances for electric-field-sensitive scanning probes

We have developed a modeling method suitable for analyzing single- and multiple-electron resonances detected by electric-field-sensitive scanning probe techniques. The method is based on basic electrostatics and a numerical boundary-element approach. The results compare well to approximate analytical expressions and experimental data.
Analysis of GMSK with Two-Bit Differential Detection in Land Mobile Radio Channels

The effect of intersymbol interference (ISI) of Gaussian filtered minimum shift keying (GMSK) on the probability of error of twobit differential detection is analyzed theoretically in fast Rayleigh fading characterizing land mobile radio channels. A closed form expression is derived for the probability of error. Numerical results are presented for cases of practical interest to researchers and designers of cellular land mobile radio systems.
Optical-parametric-amplification imaging of complex objects

We used ultrafast Fourier-plane optical-parametric-amplification (OPA) imaging to simultaneously image, wavelength-shift, and amplify complex two-dimensional objects with spatial features from 1.1 to 10.1 line pairs/millimeter (lp/mm) in the vertical dimension and from 2.0 to 16.0 lp/mm in the horizontal dimension, corresponding to a two-dimensional space-bandwidth product (SBP) of ~46,000. This represents an increase in image complexity over previous analogous OPA imaging systems by over three orders of magnitude. We observe both wavelength-shifting the image from 930 nm to a wavelength of 700 nm and image amplification by two orders of magnitude. Our wavelength-shifted image has a SBP of ~30,000.
Urban Infrastructure Finance from Private Operators: What Have We Learned From Recent Experience?

The author examines the role of private participation in infrastructure (PPI) in mobilizing finance for key urban services, that is, urban roads, municipal solid waste management, and water and sanitation since the early 1990s when private participation came to be seen as a key element in infrastructure development. Her review indicates that for financing urban services, PPI has disappointed-playing a far less significant role than was hoped for, and which might be expected given the attention it has received and continues to receive in strategies to mobilize financing for infrastructure. Looking beyond the number, the author examines transactions and finds that there are good reasons-practical, political, economic and institutional-for these disappointments. Recommending that cities in developing countries try harder is not likely to relieve all these constraints. Experience shows that there are a number of features that raise the risk profile of urban infrastructure for private investors, which has meant that the bulk of the transactions that have taken place have been exceptions rather than harbingers of a growing trend. Many of the measures that could reduce the risk profile are outside the control of many cities, others unlikely to change, and yet another group of steps to be taken that would improve prospects for urban service provision, whether in the hands of public or private operators. These findings suggest a more pragmatic and selective approach to the focus on PPI as a source of finance, and more focus on the array of some of the fundamental steps, among them strengthening the public finances of cities to improve both the capacity to deliver services and to reduce the risks that private investors must take when they invest in urban infrastructure.
Some new results in testing for economies of scale in computing: 1985 and 1988 data

Abstract This paper presents and evaluates a new specification of models used to test for the presence of economies of scale in computer processing power. An analysis of data for systems available in 1985 (which has been analyzed previously in the literature) is consistent with this specification. Analyses of a new set of data for systems available in 1988 are also performed using the same method. These results are also consistent with the specification, and in addition imply statistically significant diseconomies of scale. A discussion of some managerial implications of the results is also presented, as well as suggestions for future research.
Scalar fields, energy conditions and traversable wormholes

We describe the different possibilities that a simple and apparently quite harmless classical scalar field theory provides to violate the energy conditions. We demonstrate that a non-minimally coupled scalar field with a positive curvature coupling ξ>0 can easily violate all the standard energy conditions, up to and including the averaged null energy condition (ANEC). Indeed, this violation of the ANEC suggests the possible existence of traversable wormholes supported by non-minimally coupled scalars. To investigate this possibility we derive the classical solutions for gravity plus a general (arbitrary ξ) massless non-minimally coupled scalar field, restricting attention to the static and spherically symmetric configurations. Among these classical solutions we find an entire branch of traversable wormholes for every ξ>0. (This includes and generalizes the case of conformal coupling ξ = (1/6) we considered in 1999 Phys. Lett. B 466 127-34.) For these traversable wormholes to exist we demonstrate that the scalar field must reach trans-Planckian values somewhere in the geometry. We discuss how this can be accommodated within the current state of the art regarding scalar fields in modern theoretical physics. We emphasize that these scalar field theories, and the traversable wormhole solutions we derive, are compatible with all known experimental constraints from both particle physics and gravity.
The Challenge to Macromolecular Science

Abstract Brief historical review of the development of macromolecular science and some of the challenges for present and future research.
Retail Location Choice with Complementary Goods: An Agent-Based Model

This paper models the emergence of retail clusters on a supply chain network comprised of suppliers, retailers, and consumers. Firstly, an agent-based model is proposed to investigate retail location distribution in a market of two complementary goods. The methodology controls for supplier locales and unit sales prices of retailers and suppliers, and a consumer’s willingness to patronize a retailer depends on the total travel distance of buying both goods. On a circle comprised of discrete locations, retailers play a non-cooperative game of location choice to maximize individual profits. Our findings suggest that the probability distribution of the number of clusters in equilibrium follows power law and that hierarchical distribution patterns are much more likely to occur than the spread-out ones. In addition, retailers of complementary goods tend to co-locate at supplier locales. Sensitivity tests on the number of retailers are also performed. Secondly, based on the County Business Patterns (CBP) data of Minneapolis-St. Paul from US Census 2000 database, we find that the number of clothing stores and the distribution of food stores at the zip code level follows power-law distribution.
Nocturnal wind direction shear and its potential impact on pollutant transport

The estimation of transport and diffusion of airborne pollutants during the nighttime is challenging, especially over complex terrain where gravity driven drainage flows may be overlain with wind from a different direction. This study investigates the character of wind direction shear in the lowest 100 m using tower measurements from a complex, semi-arid site where local thermally-driven flows are common. The effects of wind direction shear on plume transport are studied by simulating a hypothetical elevated term release. This is accomplished by first simulating transport and dispersion using wind measurements from only the 12-m level from a network of towers. This case represents the approach commonly taken at many facilities where a network of short towers is available. Then the release is modeled using wind measurements made at four levels in the lowest 100 m. The differences between the two simulations are significant and would lead to very different responses in an emergency situation.
Learning syntactic rules and tags with genetic algorithms for information retrieval and filtering: an empirical basis for grammatical rules

Abstract The grammars of natural languages may be learned by using genetic algorithms that reproduce and mutate grammatical rules and part-of-speech tags, improving the quality of later generations of grammatical components. Syntactic rules are randomly generated and then evolve; those rules resulting in improved parsing and occasionally improved retrieval and filtering performance are allowed to further propagate. The LUST system learns the characteristics of the language or sublanguage used in document abstracts by learning from the document rankings obtained from the parsed abstracts. Unlike the application of traditional linguistic rules to retrieval and filtering applications, LUST develops grammatical structures and tags without the prior imposition of some common grammatical assumptions (e.g. part-of-speech assumptions), producing grammars that are empirically based and are optimized for this particular application.
Carbon-Hydrogen (C-H) Bond Activation at PdIV: A Frontier in C-H Functionalization Catalysis.

The direct functionalization of carbon–hydrogen (C–H) bonds has emerged as a versatile strategy for the synthesis and derivatization of organic molecules. Among the methods for C–H bond activation, catalytic processes that utilize a PdII/PdIV redox cycle are increasingly common. The C–H activation step in most of these catalytic cycles is thought to occur at a PdII centre. However, a number of recent reports have suggested the feasibility of C–H cleavage occurring at PdIV complexes. Importantly, these latter processes often result in complementary reactivity and selectivity relative to analogous transformations at PdII. This mini review highlights proposed examples of C–H activation at PdIV centres. Applications of this transformation in catalysis as well as mechanistic details obtained from stoichiometric model studies are discussed. Furthermore, challenges and future perspectives for the field are reviewed.
PRMT4 blocks myeloid differentiation by assembling a Methyl-RUNX1-dependent repressor complex

SUMMARY Defining the role of epigenetic regulators in hematopoiesis has become critically important, because recurrent mutations or aberrant expression of these genes has been identified in both myeloid and lymphoid hematological malignancies. We found that PRMT4, a type I arginine methyltransferase whose function in normal and malignant hematopoiesis is unknown, is overexpressed in acute myelogenous leukemia patient samples. Overexpression of PRMT4 blocks the myeloid differentiation of human stem/progenitor cells (HSPCs), whereas its knockdown is sufficient to induce myeloid differentiation of HSPCs. We demonstrated that PRMT4 represses the expression of miR-223 in HSPCs via the methylation of RUNX1, which triggers the assembly of a multiprotein repressor complex that includes DPF2. As part of the feedback loop, PRMT4 expression is repressed posttranscriptionally by miR-223. Depletion of PRMT4 results in differentiation of myeloid leukemia cells in vitro and their decreased proliferation in vivo. Thus, targeting PRMT4 holds potential as a novel therapy for acute myelogenous leukemia.
Symmetry of the Ginzburg Landau Minimizer in a Disc

The Ginzburg-Landau energy minimization problem for a vector field on a two dimensional disc is analyzed. This is the simplest nontrivial example of a vector field minimization problem and the goal is to show that the energy minimizer has the full geometric symmetry of the problem. The standard methods that are useful for similar problems involving real valued functions cannot be applied to this situation. Our main result is that the minimizer in the class of symmetric fields is stable, i.e., the eigenvalues of the second variation operator are all nonnegative.
Experimental Investigation of Seismic Repair and Retrofit of Bridge Columns by Composite Jackets

This paper summarizes the results of comprehensive experimental studies on half-scale bridge columns repaired and retrofitted with composite-material jackets. The experimental program was composed of two interrelated subprograms. Initially, a total of fourteen half-scale squat circular and rectangular reinforced concrete columns were tested under fully reversed cyclic shear in a double bending configuration. In order to provide a basis for comparison, a total of three as-built columns were tested. Another ten column samples were tested after being retrofitted with different composite-jacket systems. One circular as-built column was repaired after failure. The repair process involved both crack injection, as well as addition of carbon/epoxy composite jacket. The repaired column was then retested and evaluated. Experimental results showed that all as-built columns developed an unstable behavior and failed in brittle shear mode. The common failure mode for all retrofitted samples was due to flexure with sign...
Renal cell carcinoma in the pediatric population: Results from the California Cancer Registry

Background Renal cell carcinoma (RCC) is a rare disease in children and adolescents. This study aimed to review epidemiologic characteristics and survival for pediatric RCC patients using a large, population-based database. Procedure The California Cancer Registry (CCR) was reviewed from 1988 to 2004. All cases of RCC in patients younger than 21 years were identified and annual age-adjusted incidence rates were determined for the overall population and subdivided by ethnicity. Tumors were classified by stage and grade, and actuarial mortality rates were calculated. Results From 1988 to 2004, 43 cases of RCC were identified in patients younger than 21 years, accounting for 4.3% of all renal tumors in this age group. The overall annual age-adjusted incidence was 0.01/100,000 with the tumor more common in non-Hispanic blacks (0.03/100,000) compared to non-Hispanic whites (0.01/100,000), Hispanics (<0.01/100,000), and non-Hispanic Asians/Pacific Islanders (<0.01/100,000). The mean age at presentation was 15.4 years (SD 4.03, SE 0.615). RCC was identified more frequently in females (58.14%). At the time of presentation, 53.49% of tumors were localized, 20.93% were regionally advanced, and 25.58% were metastatic. The observed actuarial survival at 5 and 10 years was 61% (±15.7%). Conclusion Pediatric RCC is an uncommon and aggressive tumor that occurs most frequently in children in the second decade of life, more often in females and blacks. The epidemiological characteristics of this tumor differ from adult RCC and Wilms tumor, suggesting its distinctive biology and potential need for alternative treatment strategies. Pediatr Blood Cancer 2009;52:237–241. © 2008 Wiley-Liss, Inc.
Tenure in Agricultural Economics: A Five-Year Review

Tenure acceptance rates were quite high at agricultural economics departments during 1984–88; 85 percent of all candidates were granted tenure. Half of the 39 departments surveyed here rejected no candidates, and only four departments accounted for almost half of all tenure rejections. More rejections came at the college and campus levels than at the departmental level. There was considerable variation among the tenure documents submitted by departments on most issues including criteria and standards, the definition of service, and the treatment of multidisciplinary work. The continuation of tenure, once granted, was virtually ignored.
Oxygen cost of ventilation during incremental exercise to VO2 max.

Objective Evidence of significant oxygen requirements for ventilation during exercise (exercise hyperpnoea) prompted the investigation into whether the oxygen cost of ventilation affects the presence of a whole-body VO(2) plateau at maximal exercise. The purposes of this study were to: (i) use isocapnic hyperpnoea trials to determine the oxygen cost of ventilation (VO(2VENT)) across a range of ventilation (V(E)); (ii) determine the mean VO(2VENT) at maximal exercise expressed as a percentage of whole-body VO(2) max; and (iii) determine if a plateau in VO(2) is more evident when the VO(2VENT) is subtracted from whole-body VO(2) at maximal exercise. Methods A total of 21 subjects performed a VO(2) max test on the cycle ergometer to determine the range of V(E) for each subject. From the initial VO(2) max test, nine V(E) values across the range of V(E) were selected for each subject and the oxygen cost of each was measured. Results The mean maximal VO(2VENT) equalled 8.8 +/- 3.3% of VO(2) max and ranged from 5.0% to 17.6%. VO(2VENT) increased exponentially with increasing V(E), but there was considerable subject variability in the oxygen cost per litre of V(E) as V(E) increased. Subtracting the VO(2VENT) from whole-body VO(2) at maximal exercise increased the detection of a plateau in VO(2) at VO(2) max. Conclusions The data of the present study indicate that the VO(2VENT) is a significant portion of VO(2) max and may be a limiting factor of maximal exercise performance in some subjects.
Sample Size Planning for Statistical Power and Accuracy in Parameter Estimation

This review examines recent advances in sample size planning, not only from the perspective of an individual researcher, but also with regard to the goal of developing cumulative knowledge. Psychologists have traditionally thought of sample size planning in terms of power analysis. Although we review recent advances in power analysis, our main focus is the desirability of achieving accurate parameter estimates, either instead of or in addition to obtaining sufficient power. Accuracy in parameter estimation (AIPE) has taken on increasing importance in light of recent emphasis on effect size estimation and formation of confidence intervals. The review provides an overview of the logic behind sample size planning for AIPE and summarizes recent advances in implementing this approach in designs commonly used in psychological research.
1,3-Asymmetric induction in the aldol addition reactions of methyl ketone enolates and enolsilanes to β-substituted aldehydes. A model for chirality transfer

Abstract The direction and degree of 1,3-asymmetric induction have been evaluated in the addition of metal enolates and enolsilanes to aldehydes substituted at the β position with both polar (OR, OAc, Cl) and nonpolar (Me) substituents. A model for 1,3-asymmetric induction for polar addition processes such as the Mukaiyama aldol reaction is proposed to account for the documented trends in reaction diastereoselection for polar β-substituents.