cssi/SciSciGPT-SciSciNet huggingface dataset:
Electronic filing, tax preparers and participation in the Earned Income Tax Credit ☆

Abstract In 2002 more than 18 million low-income individual taxpayers received the Earned Income Tax Credit (EITC). Despite its size, non-participation in this program is a concern and substantial effort is devoted by the IRS, local governments and many non-profits to address it. Using variation across states in the introduction of state electronic filing programs, we show that the introduction of electronic filing had a significant effect on participation in the EITC. Our results are robust to accounting for other welfare, EITC and IRS reforms introduced during the same period. We speculate that the impact of this policy change on the tax preparation industry played an important role in increasing participation.
Performance Measurement under Rational International Overpromising Regimes

Promising somewhat more than anyone expects to be delivered remains ingrained in international agreements, clouding their expected aggregate outcomes and how to assess the Parties' performance. This persistence is explained by systematic overpromising being predictable and, up to a point, productive. I characterize this regime and its consequences and provide an empirical application to the Kyoto Protocol. Overpromising by governments or Parties can be part of a sustainable strategy for electoral success, and varies with socio-economic determinants that characterize the group regime. Thus targets need to be adjusted for regression-predicted overpromising to reveal the rationally-expected outcomes and individual countries' performance is best identified by deviations of outcomes from their adjusted rather than the agreed targets.
Stable adaptive teleoperation

A study is made of how the existence of transmission time delays affects the application of advanced robot control schemes to effective force-reflecting telerobotic systems. This application best exploits the presence of the human operator while making full use of available robot control technology and computing power. A physically motivated, passivity-based formalism is used to provide energy conservation and stability guarantees in the presence of transmission delays. The notion of wave variable is utilized to characterize time-delay systems and leads to a configuration for force-reflecting teleoperation. The effectiveness of the approach is demonstrated experimentally. Within the same framework, an adaptive tracking controller is incorporated for the control of the remote robotic system and can be used to simplify, transform, or enhance the remote dynamics perceived by the operator. >
Run Generation Revisited: What Goes Up May or May Not Come Down

We revisit the classic problem of run generation. Run generation is the first phase of external-memory sorting, where the objective is to scan through the data, reorder elements using a small buffer of size M, and output runs (contiguously sorted chunks of elements) that are as long as possible.
Wall-Crossing, Free Fermions and Crystal Melting

We describe wall-crossing for local, toric Calabi-Yau manifolds without compact four-cycles, in terms of free fermions, vertex operators, and crystal melting. Firstly, to each such manifold we associate two states in the free fermion Hilbert space. The overlap of these states reproduces the BPS partition function corresponding to the non-commutative Donaldson-Thomas invariants, given by the modulus square of the topological string partition function. Secondly, we introduce the wall-crossing operators which represent crossing the walls of marginal stability associated to changes of the B-field through each two-cycle in the manifold. BPS partition functions in non-trivial chambers are given by the expectation values of these operators. Thirdly, we discuss crystal interpretation of such correlators for this whole class of manifolds. We describe evolution of these crystals upon a change of the moduli, and find crystal interpretation of the flop transition and the DT/PT transition. The crystals which we find generalize and unify various other Calabi-Yau crystal models which appeared in literature in recent years.
State Immigration Policies: Innovation, Cooperation or Conflict?

This article considers the recent expansion of state immigration policy, focusing on how states have chosen to enter a field where federal dominance has been the norm. Using state immigration legislation in 2006 and 2007, we find that states exercise their authority in two ways. First, federal immigration laws often delegate tasks to state and local agencies or are structured to grant options for state participation. Second, states frequently create immigration policy by legislating in areas that are not directly about, but are related to immigration, thereby allowing them to develop de facto immigration policies without overstepping their restricted authority in this sphere. Even though states’ activity may be spurred by frustration with the failure of Congress to reform immigration laws, cooperation—not conflict—is the norm.
Analysis of a Single-Ended Push-Pull Audio Amplifier

This paper deals with a theoretical circuit analysis of a single-ended push-pull audio amplifier. Linear tube characteristics and small signals are assumed. The problem of impedance matching is first discussed. The properties and the requirements of a satisfactory driver stage are analyzed, and an output stage using an impedance matching output transformer is discussed. The effects of the plate-to-ground capacitance of the driver stage on the frequency-gain characteristic and of the choice of the tube and circuit parameters are analyzed. The paper concludes with some experimental results indicative of the inherant properties of the amplifier.
A dynamic programming approach to adaptive fractionation

We conduct a theoretical study of various solution methods for the adaptive fractionation problem. The two messages of this paper are as follows: (i) dynamic programming (DP) is a useful framework for adaptive radiation therapy, particularly adaptive fractionation, because it allows us to assess how close to optimal different methods are, and (ii) heuristic methods proposed in this paper are near-optimal, and therefore, can be used to evaluate the best possible benefit of using an adaptive fraction size. The essence of adaptive fractionation is to increase the fraction size when the tumor and organ-at-risk (OAR) are far apart (a 'favorable' anatomy) and to decrease the fraction size when they are close together. Given that a fixed prescribed dose must be delivered to the tumor over the course of the treatment, such an approach results in a lower cumulative dose to the OAR when compared to that resulting from standard fractionation. We first establish a benchmark by using the DP algorithm to solve the problem exactly. In this case, we characterize the structure of an optimal policy, which provides guidance for our choice of heuristics. We develop two intuitive, numerically near-optimal heuristic policies, which could be used for more complex, high-dimensional problems. Furthermore, one of the heuristics requires only a statistic of the motion probability distribution, making it a reasonable method for use in a realistic setting. Numerically, we find that the amount of decrease in dose to the OAR can vary significantly (5-85%) depending on the amount of motion in the anatomy, the number of fractions and the range of fraction sizes allowed. In general, the decrease in dose to the OAR is more pronounced when: (i) we have a high probability of large tumor-OAR distances, (ii) we use many fractions (as in a hyper-fractionated setting) and (iii) we allow large daily fraction size deviations.
Highly efficient and selective synthesis of conjugated triynes and higher oligoynes of biological and materials chemical interest via palladium-catalyzed alkynyl-alkenyl coupling.

Iteration of a Pd-catalyzed reaction of alkynyl- and oligoynylzincs with (E)-ICHCHCl followed by metalation−termination with electrophiles(E) has provided a linear route to conjugated tri- and tetraynes, and Pd-catalyzed monoalkynylation of 1,1-dibromoenynes accompanied by dehydrobromination has provided a convergent route to conjugated tri- , tetra- , and pentaynes. Both display unprecedented high efficiency and selectivity.
TWO EXOPLANETS DISCOVERED AT KECK OBSERVATORY

We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with M sin i = 27.5 M_⊕ in a 14.48 days, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m s^(–1). HD 73534 is a G5 subgiant with a Jupiter-like planet of M sin i = 1.1 M_(Jup) and K = 16 m s^(–1) in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity semiamplitudes, K, comparable to the radial velocity uncertainties. For exoplanets with periods longer than 10 days, the observed exoplanet eccentricity distribution is nearly flat for large amplitude systems (K > 80 m s^(–1)), but rises linearly toward low eccentricity for lower amplitude systems (K > 20 m s^(–1)).
Pulsars and Physics

Twenty-five years of active pulsar research have yielded a quite unexpected harvest of physical effects. These range from pleasing corroborations of well-established physical principles in unfamiliar environments to direct verification of the general theory of relativity. Pulsars have the potential for advancing our understanding of high energy nuclear physics and relativistic plasma physics. They have also enlarged our horizons in atomic physics, quantum electrodynamics and solid state physics. As extremely compact sources of regularly pulsed, high brightness radio waves, they provide excellent probes of the interstellar medium and globular clusters. The large variety of connections between pulsars and physics is illustrated with examples taken from each of these areas.
Mortality, inequality and race in American cities and states

A number of studies have found that mortality rates are positively correlated with income inequality across the cities and states of the US. We argue that this correlation is confounded by the effects of racial composition. Across states and Metropolitan Statistical Areas (MSAs), the fraction of the population that is black is positively correlated with average white incomes, and negatively correlated with average black incomes. Between-group income inequality is therefore higher where the fraction black is higher, as is income inequality in general. Conditional on the fraction black, neither city nor state mortality rates are correlated with income inequality. Mortality rates are higher where the fraction black is higher, not only because of the mechanical effect of higher black mortality rates and lower black incomes, but because white mortality rates are higher in places where the fraction black is higher. This result is present within census regions, and for all age groups and both sexes (except for boys aged 1-9). It is robust to conditioning on income, education, and (in the MSA results) on state fixed effects. Although it remains unclear why white mortality is related to racial composition, the mechanism working through trust that is often proposed to explain the effects of inequality on health is also consistent with the evidence on racial composition and mortality.
Employment Growth and the Allocation of New Jobs: Evidence from the South*

A county-level labor market model is estimated for the 13 southern states. The model accounts for inter-county commuting, migration, and within-county adjustments to labor demand shocks. Econometric results indicate that most employment growth during the 1990s was accommodated by changes in commuting flows. The results also suggest that labor force growth and, by extension, population growth and associated fiscal impacts are sensitive to employment growth in nearby counties. These results highlight two opposing forces related to spatial spillovers that are usually neglected in analyses of the economic and fiscal impacts of employment growth.
Bandwidth efficient OFDM transmitter diversity techniques

Space-time block-coded orthogonal frequency division multiplexing (OFDM) transmitter diversity techniques have been shown to be efficient means of achieving near-optimal diversity gain in frequency-selective fading channels. However, these known techniques all require a cyclic prefix to be added to the transmitted symbols, resulting in bandwidth expansion. In this paper, iterative space-time and space-frequency block-coded OFDM transmitter diversity techniques are proposed that exploit spatial diversity to improve spectral effciency by eliminating the need for a cyclic prefix.
Materials requirements for optical processing and computing devices

Devices for optical processing and computing systems are discussed, with emphasis on the materials requirements imposed by functional constraints. Generalized optical processing and computing systems are described in order to identify principal categories of requisite components for complete system implementation. Three principal device categories are selected for analysis in some detail: spatial light modulators, volume holographic optical elements, and bistable optical devices. The implications for optical processing and computing systems of the materials requirements identified for these device categories are described, and directions for future research are proposed.
Circular implementation of vector-channel lattices

Discusses the circular (or periodic) implementation of vector-channel least-squares lattice filters. The resulting algorithm eliminates matrix inversions and greatly reduces matrix multiplications. Complete residual and AR coefficient algorithms are provided, as well as initialization and other implementation issues. A full treatment of the prediction error form of the lattices and its relationship to the residual form is also included.
Space-time finite element techniques for computation of fluid-structure interactions

We describe the space–time finite element techniques we developed for computation of fluid–structure interaction (FSI) problems. Among these techniques are the deforming-spatial-domain/stabilized space–time (DSD/SST) formulation and its special version, and the mesh update methods, including the solid-extension mesh moving technique (SEMMT). Also among these techniques are the block-iterative, quasi-direct and direct coupling methods for the solution of the fully discretized, coupled fluid and structural mechanics equations. We present some test computations for the mesh moving techniques described. We also present numerical examples where the fluid is governed by the Navier– Stokes equations of incompressible flows and the structure is governed by the membrane and cable equations. Overall, we demonstrate that the techniques we have developed have increased the scope and accuracy of the methods used in computation of FSI problems. � 2005 Elsevier B.V. All rights reserved.
ORGANOTIN CLUSTER CHEMISTRY

Abstract A rich cluster chemistry of organotin compounds has recently emerged based on Sn-O-Sn and Sn-S-Sn bonding formed in reactions of stannonic acids with carboxylic and phosphorus-based acids as participating ligands. In the development of the underlying chemistry, it was discovered that some members exhibit catalytic activity on transesterification and potentially in polymerization processes. Further, as new cluster compositions were uncovered, analogies became apparent with other cluster chemistries, particularly those involving aluminum-nitrogen and iron-sulfur systems. What follows is a description of the emerging cluster chemistry of these interesting new classes of organotin compounds, their interconversions, and possible applications.
Singular structure in 4D simplicial gravity

Abstract We show that the phase transition previously observed in dynamical triangulation models of quantum gravity can be understood as being due to the creation of a singular link. The transition between singular and non-singular geometries as the gravitational coupling is varied appears to be first order.
Leaning on the Ethical Crutch: A Critique of Codes of Ethics

What?s a profession without a code of ethics? Being a legitimate profession almost requires drafting a code and, at least nominally, making members follow it. Codes of ethics (henceforth ?codes?) exist for a number of reasons ? many of which can vary widely from profession to profession ? but above all they are a form of codified self-regulation. Jamal and Bowie [12], in their conceptual framework for creating a meaningful code, classify three provisions that professional codes are meant to address:
The P2X7 Receptor: A Novel Biomarker of Uterine Epithelial Cancers

Objective: To determine expression of the P2X7 receptor in normal and in cancer uterine tissues. The rationale was that the receptor P2X7 regulates constitutive apoptosis in uterine epithelial cells, and previous studies showed diminished P2X7-mediated apoptosis in cancer uterine cells compared with normal cells. Methods: A clinical, experimental feasibility study. Normal ( n = 42) and cancer uterine tissues ( n = 47) were obtained from a total of 72 women ages 25 to 75. End points for P2X7 mRNA were quantitative PCR and in situ hybridization, and end points for P2X7 protein were Western blots and immunostaining using anti-P2X7 antibody. Results: ( a ) In normal uteri, P2X7 mRNA and protein were expressed predominantly in the epithelial (endometrial, endocervical, and ectocervical) cells. ( b ) Expression of the P2X7 mRNA and protein was absent from endometrial and endocervical adenocarcinoma tissues and from cervical squamous cell carcinoma tissues. ( c ) In cervical dysplasia, P2X7 protein was absent in the dysplastic lesions. ( d ) Semiquantitative analysis using P2X7 mRNA (normalized in each tissue to the constitutive glyceraldehyde-3-phosphate dehydrogenase) and P2X7 protein levels (normalized in each tissue to the constitutive tubulin) revealed that P2X7 mRNA and/or protein levels can distinguish uterine normal from cancer tissues at high degrees of sensitivity (92%, 100%) and specificity (100%, 90%). Summary and Conclusions: ( a ) Levels of the P2X7 are lower in uterine epithelial cancer tissues than in the corresponding normal tissues. ( b ) The data suggest that tissue P2X7 mRNA and protein levels could be used as a novel biomarker to differentiate normal and cancer uterine epithelial tissues. (Cancer Epidemiol Biomarkers Prev 2006;15(10):1906–13)
Returns to MBA quality: Pecuniary and non-pecuniary returns to peers, faculty, and institution quality☆

Abstract A large literature has focused on estimating the returns to schooling and has typically done so by incorporating institutional heterogeneity in quality along merely one dimension (such as average SAT scores). Using longitudinal survey data of registrants for the GMAT exam and school level information from other sources, we create, in the context of graduate management education, multiple indices of school quality, and estimate the effect of these quality measures on multiple indicators of career success. In particular, we create quality measures of MBA programs based on: (1) institutional and curricular factors, (2) characteristics of the student body, and (3) characteristics of the faculty. We create aggregate quality indices by combining individual proxies using factor analysis. We also extend the literature by considering the effects of quality on both earnings and non-monetary outcomes, namely attainment of managerial goals relative to initial individual expectations, self-assessed skill gains, and various measures of job satisfaction. We include several unique individual control variables, and further control for unobserved heterogeneity through the use of instrumental variables and individual fixed effects. Results indicate that the quality of peers and schools may matter most for earnings. When individual fixed effects are included, estimates of quality premiums diminish somewhat, though the estimated premium associated with school quality increases, emphasizing the importance of controlling for selection into programs of varying quality. School quality is also an important predictor of several non-pecuniary outcomes.
Time‐series–cross‐section Data

This article treats the analysis of ‘time‐series–cross‐section’ (TSCS) data. Such data consists of repeated observations on a series of fixed units. Examples of such data are annual observations on the political economy of OECD nations in the post‐war era. TSCS data is distinguished from ‘panel’ data, in that asymptotics are in the number of repeated observations, not the number of units. The article begins by treating the complications of TSCS data in an ‘old‐fashioned’ manner, that is, as a nuisance which causes estimation difficulties. It claims that TSCS data should be analyzed via ordinary least squares with ‘panel correct standard errors’ rather than generalized least squares methods. Dynamics should be modeled via a lagged dependent variable or, if appropriate, a single equation error correction model. The article then treats more modern issues, in particular, the modeling of spatial effects and heterogeneity. It also claims that heterogeneity should be assessed with ‘panel cross‐validation’ as well as more standard tests. The article concludes with a discussion of estimation in the presence of a binary dependent variable.
CAPITAL FLOWS, CONSUMPTION BOOMS AND ASSET BUBBLES: A BEHAVIOURAL ALTERNATIVE TO THE SAVINGS GLUT HYPOTHESIS

Bernanke (2005) hypothesized that a "global savings glut" was causing large trade imbalances. However, we show that the global savings rates did not show a robust upward trend during the relevant period. Moreover, if there had been a global savings glut there should have been a large investment boom in the countries that imported capital. Instead, those countries experienced consumption booms. National asset bubbles explain the international imbalances. The bubbles raised consumption, resulting in large trade deficits. In a sample of 18 OECD countries plus China, movements in home prices alone explain half of the variation in trade deficits.
Global particle simulation for a space weather model: present and future

The authors report progress in the long-term effort to represent the interaction of the solar wind with the Earth's magnetosphere using a three-dimensional electromagnetic particle model (EMPM) as a space weather model. Magnetohydrodynamic (MHD) simulation models have been refined to establish quantitative global modeling in comparison with observations. The EMPM has become more feasible as the power and speed of supercomputers have improved in recent years. Simulations with southward and dawnward turning IMFs have revealed the fundamental processes which have been confirmed by MHD simulations and observations. After a quasisteady state is established with an unmagnetized solar wind, a southward IMF is switched on, which causes the magnetosphere to stretch with reconnection at the dayside magnetopause. The plasma sheet in the near-Earth magnetotail clearly thins. The cross-field current also thins and intensifies, which excites a kinetic (drift kink) instability along the dawn-dusk direction. As a result of this instability the electron compressibility effect appears to be reduced and to allow the collisionless tearing to grow rapidly with the reduced B/sub z/ component. Later, magnetic reconnection also takes place in the near-Earth magnetotail. In the case where the northward IMF is switched gradually to dawnward, magnetic reconnection takes place at both the dawnside and duskside. The arrival of dawnward IMF at the magnetopause creates a reconnection groove which causes particle entry into the deep region of the magnetosphere via field lines that go near the magnetopause. The flank weak-field region joins onto the plasma sheet and the current sheet to form a geometrical feature called the cross-tail S that structurally integrates the magnetopause and the tail interior.
Is Health Politics Different

The aging of the global population, combined with changes in technology and cultural understandings of disease and the body, have thrust discussion and contestation over health into the center of local, national, and global politics. Is the politics of health different from the politics of other policy domains? On a number of dimensions, I conclude that it is. Voters and politicians in the developed world appear more likely to accept redistributive claims with respect to health than they are in other policy areas. Nations vary less widely in spending on health than on other functions of government and policy. Moral claims made about health are more likely to attach to its politics than are moral claims about the environment, labor, finance, and energy. More than these other realms, health politics encompasses issues regarding identity, the human body, and other personal matters that endow the health arena with greater significance. Bureaucratic agencies of state are more involved in the provision and regu...
Geometry of manifolds with densities

Abstract We study the geometry of complete Riemannian manifolds endowed with a weighted measure, where the weight function is of quadratic growth. Assuming the associated Bakry–Emery curvature is bounded from below, we derive a new Laplacian comparison theorem and establish various sharp volume upper and lower bounds. We also obtain some splitting type results by analyzing the Busemann functions. In particular, we show that a complete manifold with nonnegative Bakry–Emery curvature must split off a line if it is not connected at infinity and its weighted volume entropy is of maximal value among linear growth weight functions. While some of our results are new even for the gradient Ricci solitons, the novelty here is that only a lower bound of the Bakry–Emery curvature is involved in our analysis.
Biomedical imaging using optical coherence tomography

Optical coherence tomography (OCT) is a new and powerful technology that can overcome many of the limitations of excisional biopsy. OCT is a recently developed optical imaging technique for performing high-resolution cross-sectional imaging tomography of microstructures in biological systems. OCT performs imaging by using low-coherence interferometry to measure the optical backscattering of tissue as a function of echo delay and transverse position. The resulting two-dimensional data can be displayed as a gray scale or false color image. OCT functions as a type of "optical biopsy" to provide cross-sectional images of tissue structure on the micron scale. OCT is a powerful imaging technology because it can provide images of tissue in situ and in real time, without the need for tissue excision and processing. This presentation will review recent advances in OCT technology and possible future clinical applications such as arterial imaging, the detection of early neoplastic changes, and guiding surgical intervention.
Did the Arctic ice recover? Demographics of true and false climate facts

AbstractBeliefs about climate change divide the U.S. public along party lines more distinctly than hot social issues. Research finds that better-educated or informed respondents are more likely to align with their parties on climate change. This information–elite polarization resembles a process of biased assimilation first described in psychological experiments. In nonexperimental settings, college graduates could be prone to biased assimilation if they more effectively acquire information that supports their beliefs. Recent national and statewide survey data show response patterns consistent with biased assimilation (and biased guessing) contributing to the correlation observed between climate beliefs and knowledge. The survey knowledge questions involve key, uncontroversial observations such as whether the area of late-summer Arctic sea ice has declined, increased, or declined and then recovered to what it was 30 years ago. Correct answers are predicted by education, and some wrong answers (e.g., more ...
Direct inhibition by angiotensin II of insulin-dependent glucose transport activity in mammalian skeletal muscle involves a ROS-dependent mechanism

No previous study has investigated how the vaso-constrictive peptide Ang II impacts insulin action in isolated mammalian skeletal muscle. We investigated the molecular actions of Ang II on insulin signalling and glucose transport in skeletal muscle from lean Zucker rats. Soleus strips were incubated with insulin (5 mU/ml) and/or Ang II (500 nM) for 2 hours. Ang II caused significant (p < 0.05) inhibition of insulin-stimulated glucose transport (39%) and decreased phosphorylation of Akt Ser(473) (37%) and glycogen synthase kinase-3beta Ser(9) (42%) without affecting phosphorylation of IRS-1 Ser(307) or p38 MAPK. We used the superoxide dismutase mimetic, tempol (1 mM), to determine if reactive oxygen species (ROS) contribute to Ang II-mediated insulin resistance. Tempol partially reversed (42%) Ang II-induced inhibition of insulin-stimulated glucose transport. These results indicate that Ang II inhibits distal insulin signalling and insulin-stimulated glucose transport in isolated mammalian skeletal muscle, and that this effect is partially mediated by ROS.
Using Local Comprehensive Planning to Control Lakewater Pollution in Seasonal Home Communities

A GROWING body of research indicates the rising economic importance of preventing lakewater pollution in second home communities. Estimated annual local cottage-user expenditures of $1,800 per unit influence many local government decisions that sharply affect summer home growth potential [3]. Lakewater pollution and over-eutrophycation resulting from lakeshore use must be controlled. How much is this going to cost and how will the total cost be allocated? What is the role of local comprehensive planning and zoning in determining answers to these questions? Clearly, the value of comprehensive planning varies with the source of pollution. Where pollution results from aggregations of people, farming operations or industrial activity, pollution control costs should be assumed by each polluter. These costs will not affect most location decisions since they usually cannot be avoided by locating elsewhere. Each violation or potential violation warrants individual attention. Such customary preventive devices as code enforcement, regulation, inspection, and licensing can be economical and successful. Action by a state agency, if adequately financed, may be quite appropriate. Local comprehensive planning will have, at most, a relatively minor role. Pollution traced to lakeshore residential property presents a different situation. Presumably, the incidence of cost still should rest largely on the polluter, i.e. the resident or the seasonal homeowner. But the amount of cost can be sharply affected by comprehensive planning. Lower costs will attract potential vacation home buyers. Thus, comprehensive planning can contribute to economic development. Comprehensive planning operates well only in a dynamic setting. Seasonal home communities are growing rapidly. Nationwide, the decade of the fifties saw a 74 percent rise in census-enumerated second homes to a
Deciding between I(1) and I(0)

Abstract A class of procedures that consistently classify the stochastic component of a time series as being integrated either of order zero [I(1)] or one [I(1)] are proposed for general I(0) or I(1) processes and polynomial or piecewise linear detrending. Large-sample Bayesian inference is free of nuisance parameters describing short-run dynamics and requires specifying priors only on the point hypotheses ‘I(1)’ and ‘I(1)’ thereby avoiding problematic choices of parametric priors over roots and nuisance parameters. Applied to the Nelson–Plosser (1982) data with linear detrending, these procedures largely support Nelson and Plosser's original inferences. With piecewise-linear detrending these data are typically uninformative, producing Bayes ratios close to one.
BOUNDING RIGHT-ARM ROTATION DISTANCES

Rotation distance measures the difference in shape between binary trees of the same size by counting the minimum number of rotations needed to transform one tree to the other. We describe several types of rotation distance where restrictions are put on the locations where rotations are permitted, and provide upper bounds on distances between trees with a fixed number of nodes with respect to several families of these restrictions. These bounds are sharp in a certain asymptotic sense and are obtained by relating each restricted rotation distance to the word length of elements of Thompson's group F with respect to different generating sets, including both finite and infinite generating sets.
Remote text access in a computerized library information retrieval system

As part of the Intrex experiments with a computerized model library, we are developing an experimental system for accessing the full text of the 10,000 journal articles in the Intrex data base. The essential result of the user dialog with the augmented catalog is the identification of those articles selected as relevant to the user's inquiries. The next step in the library-usage process is to retrieve the text of these articles for reading. The convenience, response time, and quality of the text-access system is likely to affect the extent to which the user negotiates with the catalog before requesting full text. The Intrex system will permit experimentation with the complete machine-aided library operation. The purpose of this paper is to outline the text access problems and our approach to them.
Efficiency or innovation: how do industry environments moderate the effects of firms' IT asset portfolios?

Firms invest in a variety of information technologies and seek to align their IT asset portfolios with two key performance outcomes: efficiency and innovation. Existing research makes the universalistic assumption that both outcomes will always be realized through firms' IT asset portfolios. There has been limited research on the conditions under which firms' IT asset portfolios should be oriented more toward efficiency or innovation. Here, we argue that the nature of the industry where a firm competes will have a significant moderating effect on the link between firms' IT asset portfolios and efficiency or innovation outcomes. Using panel data that covers a wide range of industry environments, we find that at lower levels of dynamism, munificence, and complexity, IT asset portfolios are associated with a greater increase in efficiency. In contrast, in environments with higher levels of complexity, IT asset portfolios are associated with a greater increase in innovation (i.e., development of new products and processes, and exploration of growth opportunities). These results provide insights about how firms could realize strategic alignment by tailoring their IT asset portfolios toward an efficiency or innovation focus.
The Dirichlet problem on quadratic surfaces

We give a fast, exact algorithm for solving Dirichlet problems with polynomial boundary functions on quadratic surfaces in R n such as ellipsoids, elliptic cylinders, and paraboloids. To produce this algorithm, first we show that every polynomial in R n can be uniquely written as the sum of a harmonic function and a polynomial multiple of a quadratic function, thus extending a theorem of Ernst Fischer. We then use this decomposition to reduce the Dirichlet problem to a manageable system of linear equations. The algorithm requires differentiation of the boundary function, but no integration. We also show that the polynomial solution produced by our algorithm is the unique polynomial solution, even on unbounded domains such as elliptic cylinders and paraboloids.
Efficient Identity-Based and Authenticated Key Agreement Protocol

Several identity based and implicitly authenticated key agreement protocols have been proposed in recent years and none of them has achieved all required security properties. It remains an open question to design secure identity based and implicitly authenticated key agreement protocols. In this paper, we propose an efficient identity-based and authenticated key agreement protocol IDAK using Weil/Tate pairing. The security of IDAK is proved in Bellare-Rogaway model. Several required properties for key agreement protocols are not implied by the Bellare-Rogaway model. We proved these properties for IDAK separately.
Theoretical investigation of water formation on Rh and Pt Surfaces

Catalytic water formation from adsorbed H and O adatoms is a fundamental reaction step in a variety of technologically important reactions involving organic molecules. In particular, the water-formation rate determines the selectivity of the catalytic partial oxidation of methane to syngas. In this report we present a theoretical investigation of the potential-energy diagram for water formation from adsorbed O and H species on Rh(111) and Pt(111) surfaces. The study is based on accurate first-principles calculations applying density-functional theory. Our results are compared to the potential-energy diagram for this reaction inferred from experimental data by Hickman and Schmidt [AIChE. J. 39, 1164 (1993)]. The calculations essentially reproduce the scheme of Hickman and Schmidt for water formation on Rh(111) with the important difference that the OH molecule is significantly more stable than assumed by Hickman and Schmidt. On Pt(111) surfaces, however, the calculations predict a barrier to OH formation very similar to that found on Rh(111). In particular, the calculated barrier to OH formation of about 20 kcal/mol seems to contradict the small 2.5 kcal/mol barrier assumed in the Hickman–Schmidt scheme and the observed large rate of water formation on Pt. A possible explanation for the apparent discrepancy between the large calculated barrier for OH formation on Pt and the experimentally observed rapid formation of water even at low temperatures is that the active sites for water formation on Pt are at “defect” sites and not on the ideally flat terraces. A similar conclusion has been reached by Verheij and co-workers [Surf. Sci. 371, 100 (1997); Chem. Phys. Lett. 174, 449 (1990); Surf. Sci. 272, 276 (1991)], who did detailed experimental work on water formation on Pt surfaces. Analyzing our results, we develop an explicit picture of the interaction processes governing the formation of OH groups. This picture rationalizes the calculated weak dependence of OH formation on substrate material. An important conclusion from this work is that “good” catalysts for the partial oxidation of hydrocarbons should resist defect formation at their surfaces.
Impact of behavioral issues on green growth policies and weather-related disaster reduction in developing countries

This paper focuses on how developing countries can change the way they prepare for disasters so they are better equipped to sustain economic growth. It discusses the importance of considering the goals of key decision makers and the need to understand the perceptions, systematics biases, and heuristics used by the relevant interested parties (the affected public, private and public sector organizations, and nongovernmental organizations) in choosing between alternatives. The paper highlights the importance of undertaking benefit-cost analysis to evaluate disaster risk reduction measures, recognizing that decision makers might not make meaningful use of this policy tool given their behavioral biases and simplified heuristics. To address these issues, the authors propose green growth strategies that involve multi-year contracts coupled with short-term incentives that have a chance of being implemented. The strategies focus on the role of multi-year micro-insurance, long-term loans, and multi-year catastrophe bonds that reflect the institutional arrangements in the developing country. The paper illustrates this proposal in the case of farmers' agricultural practices and investment decisions that reduce losses to property from catastrophic disasters such as drought.
Reactivity of cross-conjugated (pentadienyl)iron cations: formation of diene and trimethylenemethane complexes

Abstract The title cations can be generated from the BF 3 .Et 2 O mediated ionization of (acetoxymethylene-butadiene)Fe(CO) 3 complexes. The cation reacts with carbon nucleophiles predominantly at C-4 to afford (trimethylenemethane)Fe(CO) 3 products.
A neural network approach to CSG-based 3-D object recognition

Describes the recognition subsystem of a computer vision system based on constructive solid geometry (CSG) representation scheme. Instead of using the conventional CSG trees to represent objects, the proposed system uses an equivalent representation scheme-precedence graphs-for object representation. Each node in the graph represents a primitive volume and each are between two nodes represents the relation between them. Object recognition is achieved by matching the scene precedence graph to the model precedence graph. A constraint satisfaction network is proposed to implement the matching process. The energy function associated with the network is used to enforce the matching constraints including match validity, primitive similarity, precedence graph preservation, and geometric structure preservation. The energy level is at its minimum only when the optimal match is reached. Experimental results on several range images are presented to demonstrate the proposed approach. >
Polysilanes–A New Look at Some Old Materials

In spite of the fact that the first polysilane derivatives were probably prepared in the mid 1920′s, there was little scientific interest until recently. The synthesis of the first soluble homo and copolymers about 10 years ago has stimulated an explosive development of this class of materials. This brief review traces the historical development of the polysilanes and focuses on recent studies of polymer structure, electronic properties, photochemical reactions and mechanisms and finally on new applications.
Cost-effectiveness of ceftazidime by continuous infusion versus intermittent infusion for nosocomial pneumonia.

Study Objective. To determine if continuous-infusion ceftazidime is more cost-effective and efficacious than intermittent infusion in patients with nosocomial pneumonia. Design. Prospective, open-label, randomized trial. Setting. Large, community teaching hospital. Patients. Intensive care unit (ICU) patients with nosocomial pneumonia. Interventions. Ceftazidime 3 g/day was administered as a continuous infusion or as 2 g 3 times/day by intermittent infusion to treat nosocomial pneumonia in the ICU. Patients also received tobramycin 7 mg/kg once/day. Measurements and Main Results. Thirty-five patients were evaluable; 17 received continuous infusion and 18 intermittent infusion. Clinical efficacy (94% and 83% successful outcomes with continuous and intermittent infusion, respectively), adverse events, and length of stay did not vary significantly between groups. Costs associated with continuous infusion, $627 ± 388, were significantly lower (p≤0.001) than with intermittent infusion, $1007 ± 430. Conclusions. Continuous infusion of ceftazidime is a cost-effective alternative to intermittent infusion for nosocomial pneumonia in the ICU.
Applications of Ultrasound to the Synthesis of Nanostructured Materials

Recent advances in nanostructured materials have been led by the development of new synthetic methods that provide control over size, morphology, and nano/microstructure. The utilization of high intensity ultrasound offers a facile, versatile synthetic tool for nanostructured materials that are often unavailable by conventional methods. The primary physical phenomena associated with ultrasound that are relevant to materials synthesis are cavitation and nebulization. Acoustic cavitation (the formation, growth, and implosive collapse of bubbles in a liquid) creates extreme conditions inside the collapsing bubble and serves as the origin of most sonochemical phenomena in liquids or liquid-solid slurries. Nebulization (the creation of mist from ultrasound passing through a liquid and impinging on a liquid-gas interface) is the basis for ultrasonic spray pyrolysis (USP) with subsequent reactions occurring in the heated droplets of the mist. In both cases, we have examples of phase-separated attoliter microreactors: for sonochemistry, it is a hot gas inside bubbles isolated from one another in a liquid, while for USP it is hot droplets isolated from one another in a gas. Cavitation-induced sonochemistry provides a unique interaction between energy and matter, with hot spots inside the bubbles of approximately 5000 K, pressures of approximately 1000 bar, heating and cooling rates of >10(10) K s(-1); these extraordinary conditions permit access to a range of chemical reaction space normally not accessible, which allows for the synthesis of a wide variety of unusual nanostructured materials. Complementary to cavitational chemistry, the microdroplet reactors created by USP facilitate the formation of a wide range of nanocomposites. In this review, we summarize the fundamental principles of both synthetic methods and recent development in the applications of ultrasound in nanostructured materials synthesis.
Practice parameter: The care of the patient with amyotrophic lateral sclerosis (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology

Mission statement. The Quality Standards Subcommittee (QSS) of the American Academy of Neurology (AAN) is charged with developing practice parameters for physicians. This evidence-based review addresses some of the major management issues in patients with ALS, and highlights the many areas in which more research is needed. ALS is a progressive, degenerative motor neuron disease of unknown cause. Muscle atrophy and spasticity in limb and bulbar muscles result in weakness and loss of ambulation, oropharyngeal dysfunction, weight loss, and ultimately respiratory failure. Although advances in understanding the pathophysiology of ALS have stimulated the development of new drug therapies,1 the mainstay of treatment for ALS patients remains symptomatic management. The practice parameters presented here comprise the first recommendations for the management of ALS based on a prescribed review and analysis of the peer-reviewed literature. These practice parameters were developed to improve the care and the quality of life of people with ALS by providing a rational basis for managing the disease. A multidisciplinary task force, all with extensive ALS experience, included 19 physicians, 3 patients with ALS, 1 gastroenterologist, 1 pulmonologist, 1 occupational therapist whose mother has ALS, and 1 nurse. In addition, consultants with expertise on ethics, practice parameter development, and medical library research participated in the process. The task force agreed to investigate five areas: 1) informing the patient and the family about the diagnosis and prognosis (also called “breaking the news”) of ALS; 2) symptomatic treatment; 3) nutrition, and decisions about percutaneous endoscopic gastroscopy (PEG); 4) respiratory insufficiency and mechanical ventilation; and 5) advance directives and palliative care. To help achieve this goal, they developed several guiding principles or attributes of care: Principles of ALS management