cssi/SciSciGPT-SciSciNet huggingface dataset:
Family Bargaining and Taxes: A Prolegomenon to the Analysis of Joint Taxation *

Does joint taxation disadvantage women? To answer that question, this paper begins by reviewing unitary and bargaining models of intrafamily allocation, and then discusses the determinants of "bargaining power" in a world without taxes. It argues that wage rates rather than earnings are determinants of bargaining power, and then argues that productivity in household production is also a source of bargaining power. In the absence of human capital effects, joint taxation does not appear to disadvantage women in either divorce threat or separate spheres bargaining. Hence, the claim that joint taxation disadvantages women, if it is correct, depends on effects that operate through the incentives to accumulate human capital. But a satisfactory analysis of the effects of taxation on human capital awaits the further development of dynamic models of family bargaining.
Selective Synthesis of (2Z,4E)-Dienyl Esters by Ene−Diene Cross Metathesis†

Cross metathesis of terminal alkenes with methyl (2Z,4E)-hexadienoate and related dienyl esters provides substituted (2Z,4E)-dienyl esters in good yields. Small-scale reactions are effectively promoted by the standard second-generation Grubbs−Hoveyda catalyst (GH-II), while a new fluorous GH-II catalyst is used for separation and recovery in gram-scale reactions. The transformation is featured in a rapid synthesis of the bottom fragments of the potent anticancer agents (−)-dictyostatin and 6-epi-dictyostatin.
Peer effects and stability in matching markets

Many-to-one matching markets exist in numerous different forms, such as college admissions, matching medical interns to hospitals for residencies, assigning housing to college students, and the classic firms and workers market. In all these markets, externalities such as complementarities and peer effects severely complicate the preference ordering of each agent. Further, research has shown that externalities lead to serious problems for market stability and for developing efficient algorithms to find stable matchings. In this paper we make the observation that peer effects are often the result of underlying social connections, and we explore a formulation of the many-to-one matching market where peer effects are derived from an underlying social network. The key feature of our model is that it captures peer effects and complementarities using utility functions, rather than traditional preference ordering. With this model and considering a weaker notion of stability, namely twosided exchange stability, we prove that stable matchings always exist and characterize the set of stable matchings in terms of social welfare. To characterize the efficiency of matching markets with externalities, we provide general bounds on how far the welfare of the worst-case stable matching can be from the welfare of the optimal matching, and find that the structure of the social network (e.g. how well clustered the network is) plays a large role.
Electrocatalytic and homogeneous approaches to conversion of CO2 to liquid fuels

Research in the field of catalytic reduction of carbon dioxide to liquid fuels has grown rapidly in the past few decades. This is due to the increasing amount of carbon dioxide in the atmosphere and a steady climb in global fuel demand. This tutorial review will present much of the significant work that has been done in the field of electrocatalytic and homogeneous reduction of carbon dioxide over the past three decades. It will then extend the discussion to the important conclusions from previous work and recommendations for future directions to develop a catalytic system that will convert carbon dioxide to liquid fuels with high efficiencies.
Effect of ambient turbulence on trailing vortices

The effects of ambient turbulence (generated by a biplanar grid) on the migration and lifespan of trailing vortices are investigated in a towing tank through the use of two NACA-0012 foils moving at a constant angle of attack. The results show that the rise and demise of the vortices are controlled primarily by the rate of dissipation of the background turbulence. The integral scale of turbulence plays only a minor role. In both a quiescent or weakly-turbulent fluid the sinusoidal instability and in a fluid with stronger turbulence, the vortex bursting precedes the subsequent instability events which brings about the eventual destruction of the vortices. Both forms of the large scale instability are often accompanied by the roll of the vortex pair onto its side. Shear is not necessary for the roll but may enhance it under atmospheric conditions. Nomenclature & - aspect ratio of the wing B = wing span 60 = initial vortex core spacing c = chord length of the wing d = width of a square bar in the grid d0 = initial depth of the vortex pair H = vortex rise height H* -H/b0y normalized migration height Ln = integral scale of turbulence M =mesh size of the grid Re = Reynolds number re = effective core radius T* - V0t/bQ, normalized time t = time U = model velocity u =x component of velocity v =y component of velocity K0 =r0/2?rZ?0, initial mutual induction velocity w = z component of velocity x,y = coordinate axes a = model angle of attack F0 = initial circulation of vortex A =d0/b0 e =rate of decay of turbulence energy e* = (eZ?0)1/3 / V0, turbulence parameter v = kinematic viscosity of water p = density of water
Selecting two-bit bit flipping algorithms for collective error correction

A class of two-bit bit flipping algorithms for decoding low-density parity-check codes over the binary symmetric channel was proposed in [1]. Initial results showed that decoders which employ a group of these algorithms operating in parallel can offer low error floor decoding for high-speed applications. As the number of two-bit bit flipping algorithms is large, designing such a decoder is not a trivial task. In this paper, we describe a procedure to select collections of algorithms that work well together. This procedure relies on a recursive process which enumerates error configurations that are uncorrectable by a given algorithm. The error configurations uncorrectable by a given algorithm form its trapping set profile. Based on their trapping set profiles, algorithms are selected so that in parallel, they can correct a fixed number of errors with high probability.
Application-aware deadlock-free oblivious routing

Conventional oblivious routing algorithms are either not application-aware or assume that each flow has its own private channel to ensure deadlock avoidance. We present a framework for application-aware routing that assures deadlock-freedom under one or more channels by forcing routes to conform to an acyclic channel dependence graph. Arbitrary minimal routes can be made deadlock-free through appropriate static channel allocation when two or more channels are available. Given bandwidth estimates for flows, we present a mixed integer-linear programming (MILP) approach and a heuristic approach for producing deadlock-free routes that minimize maximum channel load. The heuristic algorithm is calibrated using the MILP algorithm and evaluated on a number of benchmarks through detailed network simulation. Our framework can be used to produce application-aware routes that target the minimization of latency, number of flows through a link, bandwidth, or any combination thereof.
Optimal Private Responses to Demographic Trends: Savings, Bequests, and International Mobility

This paper examines the implications of population ageing in an environment of increasingly mobile capital and labour. I fi rst present three benchmark models for world savings, capital-output ratios and returns to capital and then examine their relevance for the world economy and their policy implications. The mechanics of capital deepening triggered by declining birth rates are presented in a Solow-Swan model with exogenous saving. The role of retirement savings is examined in a stylised overlapping-generations model with life-cycle savers. A dynastic model with altruism towards children highlights the interaction of savings with bequests and spending on children. All three models are calibrated to the world economy with particular attention to the G-20. The models yield different conclusions largely due to their different assumptions about bequests. While the Solow-Swan and life-cycle models suggest rising capital-labour ratios, rising capital-output ratios and a secular decline in returns to capital, the dynastic model predicts declining saving rates, a declining share of bequests in aggregate wealth and a stationary world return to capital. A substantial share of world capital is due to bequests rather than life-cycle savings. This raises doubts about the life-cycle model as a tool for demographic projections. At the same time, the projected decline in bequests also raises questions about bequests reaching a lower bound where life-cycle reasoning would become applicable. I argue that constraints on bequests are likely to be ‘soft’ (non-binding) for as long as retirees can successfully lobby for growing public transfers (serving as negative bequests). Increasing capital and labour mobility are relevant in this context because increasing cross-country tax competition would impose increasingly stringent bounds on transfers and hence on aggregate bequests. While developed countries may be close to such bounds, bequests and dynastic reasoning remain important for savings in developing countries and hence for world-wide demographic projections. 1. Department of Economics, UCSB, Santa Barbara, CA 93106. E-mail: bohn@econ.ucsb.edu. Home page: http://econ.ucsb.edu/~bohn. I would like to thank the lead discussant, Mariano Kulish, and the other conference participants for their insightful comments. The paper was previously circulated under the title ‘Optimal Private Responses to Demographic Trends: What Can Theory Tell Us?’.
Polar cap potential saturation during large geomagnetic storms

We present evidence that the cross polar cap potential saturates during the Bastille Day geomagnetic storm which is characterized by large values of the driving interplanetary electric and magnetic fields. Empirical models that were derived and constrained for more benign solar wind conditions severely over-predict the cross polar cap potential for this event. Global simulation results show that the magnetopause moves significantly inward as a result of compression and erosion of the magnetosphere. We propose a model that explains the potential saturation primarily as an effect of the shortened x-line. An appropriately modified empirical model gives much better potential prediction, supporting our hypothesis. � 2005 Published by Elsevier Ltd on behalf of COSPAR.
Statistical Inference and Meta-Analysis

Statistical inference is a common feature of meta-analysis. Statistical inference depends on a formal model that accurately characterizes certain key features of how the studies to be summarized were generated. The implications of this requirement are discussed and questions are raised about the credibility of confidence intervals and hypothesis tests routinely reported.
Stability of marriage with externalities

In many matching problems, it is natural to consider that agents may have preferences not only over the set of potential partners but also over what other matches occur. Once such externalities are considered, the set of stable matchings will depend on what agents believe will happen if they deviate. In this paper, we introduce endogenously generated beliefs (which depend on the preferences). We introduce a particular notion of endogenous beliefs, called sophisticated expectations, and show that with these beliefs, stable matchings always exist.
Finding Waldo, or focus of attention using local color information

We present a method to locate an "object" in a color image, or more precisely, to select a set of likely locations for the object. The model is assumed to be of known color distribution, which permits the use color-space processing. A new method is presented, which exploits more information than the previous backprojection algorithm of Swain and Ballard (1990) at a competitive complexity. Precisely, the new algorithm is based on matching local histograms with the model, instead of directly replacing pixels with a confidence that they belong to the object. We prove that a simple version of this algorithm degenerates into backprojection in the worst case. In addition, we show how to estimate the scale of the model. Results are shown on pictures digitized from the famous "Where is Waldo" books. Issues concerning the optimal choice of a color space and its quantization are carefully considered and studied in this application. We also propose to use co-occurrence histograms to deal with cases where important color variations can be expected. >
Replicating Replication : Due Diligence in Roodman and Morduch’s Replication of Pitt and Khandker (1998)

"The Impact of Microcredit on the Poor in Bangladesh: Revisiting the Evidence," by David Roodman and Jonathan Morduch (2011) is the most recent of a sequence of papers and postings that seeks to refute the findings of the Pitt and Khandker (1998) article "The Impact of Group-Based Credit on Poor Households in Bangladesh: Does the Gender of Participants Matter?" that microcredit for women had significant, favorable effects on poverty reduction. In thispaper the authors show that these latest Roodman and Morduch claims are based on seriously flawed econometric methods and theory and a lack of due diligence in formulating models and interpreting output from packaged software. On the basis of Roodman and Morduch's preferred two-stage least squares regression, an alternative calculation of the standard errors would lead one to conclude that the problem with Pitt and Khandker is that they underestimate the positive and statistically significant effect of women's credit on household consumption. As in their previous efforts, the methods of Roodman and Morduch are shown to bias the findings in the direction of rejecting the results of Pitt and Khandker. We also further examine two aspects of our instrumental variable approach that have been attacked by Roodman and Morduch. The first is the validity of the exclusion restrictions underlying the use of interactions between program choice and the set of exogenous variables (including the village fixed effects) as instruments. The second is the application of the "one-half acre" program eligibility rule. The authors show that identification does not require both of these, and present new results dropping each assumption in turn. The results originally reported in the Pitt and Khandker paper hold up extremely well in this new analysis.
A Concise Synthesis of R-(–)-Cicutoxin, a Natural 17-Carbon Polyenyne

A concise synthesis of the natural polyenyne R-(–)-cicutoxin (1) is described. After several trials, the successful synthesis commenced with three key fragments, R-(–)-1-hexyn-3-ol (8), 1,4-diiodo-1,3-butadiene (9), and THP-protected 4,6-heptadiyn-1-ol (6). Sonogashira coupling of compound 9 with acetylenes 6 and 8 gave the 17-carbon frame, which upon regioselective reduction of a triple bond with Red-Al and removal of the THP protecting group afforded the natural product in four linear steps. The triply convergent synthesis gave R-(–)-cicutoxin in 18 % overall yield. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Carbohydrate-based oxepines: ring expanded glycals for the synthesis of septanose saccharides

A ring-closing metathesis (RCM) approach to a family of carbohydrate-based oxepines is described. A variety of readily accessible, protected monosaccharide derived dienes were used to demonstrate the utility of the synthetic sequence and to investigate how factors such as rigidification and deoxygenation mediate RCM using the Grubbs or Schrock catalyst. The seven-membered cyclic enol ethers are ring expanded glycals to be used in the synthesis of septanose carbohydrates.
Schur Times Schubert via the Fomin-Kirillov Algebra

We study multiplication of any Schubert polynomial $\mathfrak{S}_w$ by a Schur polynomial $s_{\lambda}$ (the Schubert polynomial of a Grassmannian permutation) and the expansion of this product in the ring of Schubert polynomials. We derive explicit nonnegative combinatorial expressions for the expansion coefficients for certain special partitions $\lambda$, including hooks and the $2\times 2$ box. We also prove combinatorially the existence of such nonnegative expansion when the Young diagram of $\lambda$ is a hook plus a box at the $(2,2)$ corner. We achieve this by evaluating Schubert polynomials at the Dunkl elements of the Fomin-Kirillov algebra and proving special cases of the nonnegativity conjecture of Fomin and Kirillov. This approach works in the more general setup of the (small) quantum cohomology ring of the complex flag manifold and the corresponding (3-point) Gromov-Witten invariants. We provide an algebro-combinatorial proof of the nonnegativity of the Gromov-Witten invariants in these cases, and present combinatorial expressions for these coefficients.
Khintchine–Pollaczek formula for random walks whose steps have one geometric tail

We derive a Khinchine–Pollaczek formula for random walks whose steps have a geometric left tail. The construction rests on the memory-less property of the geometric distribution. An example from a tandem queue modeling dynamic isnstability for microtubules is given.
A fast algorithm for plotting and contour filling radiation patterns in three dimensions

An algorithm is presented for plotting antenna and scattering patterns in three dimensions. The algorithm exploits the property of single-valued surfaces to allow the implicit removal of hidden lines with virtually no extra computation. This reduces the processing time significantly over that required by more general plotting methods. The algorithm is based on finding a systematic sequence to draw the plot from back to front as a collection of quadrilaterals. Each quadrilateral can be broken into two triangles, which allows a simple contour filling scheme to be incorporated into the algorithm. >
Computing the Stationary Distribution Locally

Computing the stationary distribution of a large finite or countably infinite state space Markov Chain (MC) has become central in many problems such as statistical inference and network analysis. Standard methods involve large matrix multiplications as in power iteration, or simulations of long random walks, as in Markov Chain Monte Carlo (MCMC). Power iteration is costly, as it involves computation at every state. For MCMC, it is difficult to determine whether the random walks are long enough to guarantee convergence. In this paper, we provide a novel algorithm that answers whether a chosen state in a MC has stationary probability larger than some Δ ∈ (0,1), and outputs an estimate of the stationary probability. Our algorithm is constant time, using information from a local neighborhood of the state on the graph induced by the MC, which has constant size relative to the state space. The multiplicative error of the estimate is upper bounded by a function of the mixing properties of the MC. Simulation results show MCs for which this method gives tight estimates.
SIMULTANEOUS ESTIMATION OF TECHNOLOGY ADOPTION AND LAND ALLOCATION

The paper considers the econometric modeling of technology adoption when crop choice is simultaneous. Bivariate probit is used to estimate a model of irrigation technology choice and land allocation using a unique field-level data set from California's Central Valley. Special attention is paid to the proper calculation of marginal effects in the bivariate probit model, which are often useful for policy purposes. Estimation results confirm that the choices of irrigation technology and land allocation are simultaneous. With regard to the influence of price incentives on agricultural water use, estimation results from the bivariate probit model indicate that the influence of water price on the adoption of precision irrigation technology is much larger than previously realized. A univariate model of technology choice that treats land allocation as exogenous underestimates the effect of water price on the adoption of precision technology by over 40 percent.
Experimental Investigation of Pairs of Vortex Filaments in Ground Effect

The motion of co -rotating filaments in ground effect is investigated using a water tunnel. The vortices are generated using two flat blades and the ground is modeled with a splitter plate. The time history of the vortex motion is recorded at several downstream locations. Data is shown for two ground plane positions and compared with the vortex be havior in the free stream. The experimental data is also verified using a potential -flow model. Results show that the vortices undergo a rebound as the result of ground effect. The vortices also undergo a lateral motion due to potential flow effects. A leapfrogging behavior is present due to the differences in the lateral motions caused by the ground proximities of the spiraling vortices. In addition, the filaments form planar waves and move along preferred directions. b = vortex span at the trailing edge of the blades C = chord max min , I I = principal second moments of vortex position N = total number of vortices Re � = vortex Reynolds number = � / � S = span � V = free stream velocity z
Aligning parallel arrays to reduce communication

Axis and stride alignment is an important optimization in compiling data-parallel programs for distributed-memory machines. We previously developed an optimal algorithm for aligning array expressions. Here, we examine alignment for more general program graphs. We show that optimal alignment is NP-complete in this setting, so we study heuristic methods. This paper makes two contributions. First, we show how local graph transformations can reduce the size of the problem significantly without changing the best solution. This allows more complex and effective heuristics to be used. Second, we give a heuristic that can explore the space of possible solutions in a number of ways. We show that some of these strategies can give better solutions than a simple greedy approach proposed earlier. Our algorithms have been implemented; we present experimental results showing their effect on the performance of some example programs running on the CM-5. >
A Structured Language Model

The paper presents a language model that develops syntatic structure and uses it to extract meaningful information from the word history, thus enabling the use of long distance dependencies. The model assigns probability to every joint sequence of words-binary-parse-structure with headword annotation. The model, its probabilistic parametrization, and a set of experiments meant to evaluate its predictive power are presented.
A nonresolving infiltrate in the lung.

About 8% of diagnostic bronchoscopies and 15% of pulmonary consultations are performed to evaluate nonresolving infiltrates.1 A 47-year-old woman was referred for a bronchoscopy for a nonresolving infiltrate in the right lower lobe (RLL). She had a history of diabetes mellitus, hypertension, end-stage renal disease status after failed renal transplant and was currently on peritoneal dialysis. Her postoperative course was complicated by a vocal cord injury resulting from a traumatic intubation. She underwent a prosthetic vocal cord implant …
Cost-Sensitive Tree of Classifiers

Recently, machine learning algorithms have successfully entered large-scale real-world industrial applications (e.g. search engines and email spam filters). Here, the CPU cost during test-time must be budgeted and accounted for. In this paper, we address the challenge of balancing the test-time cost and the classifier accuracy in a principled fashion. The test-time cost of a classifier is often dominated by the computation required for feature extraction--which can vary drastically across features. We decrease this extraction time by constructing a tree of classifiers, through which test inputs traverse along individual paths. Each path extracts different features and is optimized for a specific subpartition of the input space. By only computing features for inputs that benefit from them the most, our cost-sensitive tree of classifiers can match the high accuracies of the current state-of-the-art at a small fraction of the computational cost.
Compressed Bloom filters

A Bloom filter is a simple space-efficient randomized data structure for representing a set in order to support membership queries. Although Bloom filters allow false positives, for many applications the space savings outweigh this drawback when the probability of an error is sufficiently low. We introduce compressed Bloom filters, which improve performance when the Bloom filter is passed as a message, and its transmission size is a limiting factor. For example, Bloom filters have been suggested as a means for sharing Web cache information. In this setting, proxies do not share the exact contents of their caches, but instead periodically broadcast Bloom filters representing their caches. By using compressed Bloom filters, proxies can reduce the number of bits broadcast, the false positive probability, and/or the amount of computation per lookup. The cost is the processing time for compression and decompression, which can use simple arithmetic coding, and more memory use at the proxies, which utilize the larger uncompressed form of the Bloom filter.
Physically based assessment of hurricane surge threat under climate change

Storm surges are responsible for much of the damage and loss of life associated with landfalling hurricanes. Understanding how global warming will affect hurricane surges thus holds great interest. As general circulation models (GCMs) cannot simulate hurricane surges directly, we couple a GCM-driven hurricane model with hydrodynamic models to simulate large numbers of synthetic surge events under projected climates and assess surge threat, as an example, for New York City (NYC). Struck by many intense hurricanes in recorded history and prehistory, NYC is highly vulnerable to storm surges. We show that the change of storm climatology will probably increase the surge risk for NYC; results based on two GCMs show the distribution of surge levels shifting to higher values by a magnitude comparable to the projected sea-level rise (SLR). The combined effects of storm climatology change and a 1 m SLR may cause the present NYC 100-yr surge flooding to occur every 3‐20 yr and the present 500-yr flooding to occur every 25‐240 yr by the end of the century.
FEMTOLENS IMAGING OF A QUASAR CENTRAL ENGINE USING A DWARF STAR TELESCOPE

We show that it is possible to image the structure of a distant quasar on scales of 1 AU by constructing a telescope that uses a nearby dwarf star as its "primary lens" together with a satellite-borne "secondary." The image produced by the primary is magnified by ~106 in one direction but is contracted by 0.5 in the other and therefore contains highly degenerate one-dimensional information about the two-dimensional source. We discuss various methods for extracting information about the second dimension including "femtolens interferometry" where one measures the interference between different parts of the one-dimensional image with each other. Assuming that the satellite could be dispatched to a position along a star-quasar line of sight at a distance r from the Sun, the nearest available dwarf-star primary is likely to be at ~30 pc (r/45 AU)-2. The secondary should consist of a one-dimensional array of mirrors extending ~170 m to achieve 1 AU resolution or ~350 m to achieve 1 AU resolution.
Nonparametric and Semiparametric Estimation: An Analysis of Multiproduct Returns to Scale

The nonparametric and semiparametric regression models based on kernel density estimation are reviewed, and they are applied to the analysis of returns to scale in dairy farms using a multioutput cost function. Semiparametric tests of constant returns to scale and homogeneity of production are developed, and their implementation show that both of these hypotheses are rejected. Kernel estimation of the local degree of multiproduct returns to scale confirms that the sample's dairy farms are characterized by a considerable degree of scale economies.
The history of complexity

Summary form only given. We describe several trends in the history of computational complexity, including: the early history of complexity; the development of NP-completeness and the structure of complexity classes; how randomness, parallelism and quantum mechanics has forced us to reexamine our notions of efficient computation and how computational complexity has responded to these new models; the meteoric rise and fall of circuit complexity; and the marriage of complexity and cryptography and how research on a cryptographic model led to limitations of approximation.
The Synthesis of Potential Cyclopropenyl Anion Precursors: 3-Methyl-3-trimethylsilylcyclopropene and Its Dibenzoyl Derivative

Abstract 3-Methyl-3-trimethylsilylcyclopropene ( 1 ) was prepared by reacting ( Z )-3-trimethylsilyl-2-butenyl chloride ( 5 ) with sodium amide. This compound ( 1 ) was converted to 1,2-dibenzoyl-3-methyl-3-trimethylsilylcyclopropene ( 2 ), a rare example of an isolable cyclopropene with two electron withdrawing groups at the vinyl position, and the thermal isomerization of 2 was probed. © 1997 Elsevier Science Ltd.
Magnetic-field Manipulation of Chemical Bonding in Artificial Molecules

The effect of orbital magnetism on the chemical bonding of lateral, two-dimensional artificial molecules is studied in the case of a 2e double quantum dot (artificial molecular hydrogen). It is found that a perpendicular magnetic field reduces the coupling (tunneling) between the individual dots and, for sufficiently high values, it leads to complete dissociation of the artificial molecule. The method used is building on Lowdin's work on projection operators in quantum chemistry; it is a spin-and-space unrestricted Hartree-Fock method in conjunction with the companion step of the restoration of spin and space symmetries via projection techniques (when such symmetries are broken). This method is able to describe the full range of couplings in two-dimensional double quantum dots, from the strong-coupling regime exhibiting delocalized molecular orbitals to the weak-coupling and dissociation regimes associated with a generalized valence bond combination of atomic-type orbitals localized on the individual dots. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 90: 699-708, 2002
Au20: A Tetrahedral Cluster

Photoelectron spectroscopy revealed that a 20-atom gold cluster has an extremely large energy gap, which is even greater than that of C60, and an electron affinity comparable with that of C60. This observation suggests that the Au20 cluster should be highly stable and chemically inert. Using relativistic density functional calculations, we found that Au20 possesses a tetrahedral structure, which is a fragment of the face-centered cubic lattice of bulk gold with a small structural relaxation. Au20 is thus a unique molecule with atomic packing similar to that of bulk gold but with very different properties.
Unitary equivalence to a truncated Toeplitz operator: analytic symbols

Unlike Toeplitz operators on H2, truncated Toeplitz operators do not have a natural matricial characterization. Consequently, these operators are difficult to study numerically. In this paper we provide criteria for a matrix with distinct eigenvalues to be unitarily equivalent to a truncated Toeplitz operator having an analytic symbol. This test is constructive, and we illustrate it with several examples. As a byproduct, we also prove that every complex symmetric operator on a Hilbert space of dimension ≤ 3 is unitarily equivalent to a direct sum of truncated Toeplitz operators.
Theory of Star Formation

We review current understanding of star formation, outlining an overall theoretical framework and the observations that motivate it. A conception of star formation has emerged in which turbulence plays a dual role, both creating overdensities to initiate gravitational contraction or collapse, and countering the effects of gravity in these overdense regions. The key dynamical processes involved in star formation—turbulence, magnetic fields, and self-gravity— are highly nonlinear and multidimensional. Physical arguments are used to identify and explain the features and scalings involved in star formation, and results from numerical simulations are used to quantify these effects. We divide star formation into large-scale and small-scale regimes and review each in turn. Large scales range from galaxies to giant molecular clouds (GMCs) and their substructures. Important problems include how GMCs form and evolve, what determines the star formation rate (SFR), and what determines the initial mass function (IMF). Small scales range from dense cores to the protostellar systems they beget. We discuss formation of both low- and high-mass stars, including ongoing accretion. The development of winds and outflows is increasingly well understood, as are the mechanisms governing angular momentum transport in disks. Although outstanding questions remain, the framework is now in place to build a comprehensive theory of star formation that will be tested by the next generation of telescopes.
The Effect of Decision Strategy on Deciding to Defer Choice

Recent research has examined consumer decision making when the option of not choosing any of the alternatives is also provided. The findings from this research suggest that the decision to defer choice is sensitive to the uncertainty of choosing the most preferred option from the set of alternatives provided. Building on this research, the author tests whether the decision to defer choice is also influenced by task variables that influence decision uncertainty. In the first experiment, this proposition is tested for choice problems in which information on three relatively equally attractive alternatives is presented either sequentially or simultaneously. As predicted, the preference for the defer-choice option was greater when the three alternatives were presented simultaneously. A second study forced subjects into using one of four decision strategies in order to choose between two non-dominated alternatives. The preference for the no-choice option was found to be higher when the rule required explicit attribute tradeoffs and lower when it simplified choice. These results suggest that choice uncertainty is influenced by the decision strategy used to determine the preference among alternatives. We conclude with a discussion of the implications of the results for marketers' communication strategies.
BMI Changes in Russian Adults: The Role of Health Related Behaviors and Spousal Relationships

The paper investigates the effects of changes in marital status and health related behaviors (smoking and drinking) on the body mass index (BMI) in Russian adults over a ten-year period. Smoking and drinking behavior changes have played an important part in health status changes over 1994 to 2004. The results indicate that the individual weight/BMI changes asymmetrically in health determinants; the sign and the magnitude of the response are different depending on the starting point and whether there is an increase or a decrease in the explanatory variable. Males’ BMI decreases with smoking and increases with quitting smoking, but females’ BMI increases with drinking alcohol and decreases with stopping drinking. Losing a partner decreases only the females’ BMI, but gaining a spouse/partner is associated with increases in BMI for both genders. For married females and males, the change in spousal BMI is significantly positively related. Understanding interactions between individual health-related behaviors and the set of determinants that contribute to such behaviors is a fundamental step in the design of effective interventions.
Bioenergetics of lactic acid bacteria: cytoplasmic pH and osmotolerance

Abstract Lactic acid bacteria maintain a cytoplasm that is more alkaline than the medium, but whose pH decreases as the medium is acidified during growth and fermentation. Streptococci generally acidify the cytoplasm from approximately pH 7.6 to 5.7 (external pH 4.5) before growth and then fermentation cease. The internal enzyme machinery of these anaerobic fermenters thus tolerates a fairly wide range in internal proton concentration. Lactobacilli tolerate a significantly more acidic cytoplasmic pH of 4.4 (external pH 3.5). However, when the cytoplasmic pH decreases below a threshold pH, which depends on the organism cellular functions are inhibited. Fermentation end-products, such as organic acids or alcohols, exert their deleterious effects by bringing about acidification of the cytoplasm below the permissible pH. Organic acids, which act as protonophores, or solvents, which perturb membrane phospholipids, at high concentrations increase the inward leak of H+ so that H+ efflux is not rapid enough to alkalinize the cytoplasm. The membrane pH gradient is thus dissipated. A specific strain of Lactobacillus acidophilus has been found to be unusually osmotolerant. The osmoresistance is due to the cells' capacity to accumulate glycine betaine by a transport carrier that is activated, but not induced, by high medium osmotic pressure.
ALD for clean energy conversion, utilization, and storage

Atomic layer deposition (ALD) uses self-limiting chemical reactions between gaseous precursors and a solid surface to deposit materials in a layer-by-layer fashion. This process results in a unique combination of attributes, including sub-nm precision, the capability to engineer surfaces and interfaces, and unparalleled conformality over high-aspect ratio and nanoporous structures. Given these capabilities, ALD could play a central role in achieving the technological advances necessary to redirect our economy from fossil-based energy to clean, renewable energy. This article will survey some of the recent work applying ALD to clean energy conversion, utilization, and storage, including research in solid oxide fuel cells, thin-film photovoltaics, lithium-ion batteries, and heterogenous catalysts. Throughout the manuscript, we will emphasize how the unique qualities of ALD can enhance device performance and enable radical new designs.
D-branes on the quintic

We study D-branes on the quintic CY by combining results from several directions: general results on holomorphic curves and vector bundles, stringy geometry and mirror symmetry, and the boundary states in Gepner models recently constructed by Recknagel and Schomerus, to begin sketching a picture of D-branes in the stringy regime. We also make first steps towards computing superpotentials on the D-brane world-volumes.
Agricultural Distortions, Structural Change, and Economic Growth: A Cross-Country Analysis

Taxing agriculture to mobilize resources for industrialization has been a widely used development strategy. Using novel cross‐country time‐series data sets with direct measures of agricultural taxation, we examine how a policy bias against agriculture affects the speed of convergence in income per capita, structural change, and economic growth. We find that distortionary agricultural policies in poor economies can account for the emergence of convergence clubs in our sample by significantly retarding their structural transformation and economic growth. Overall, we find no evidence suggesting that policies that discriminate against agriculture have been beneficial for long‐term economic growth.
Density functional theory and pseudopotentials: A panacea for calculating properties of materials

Although the microscopic view of solids is still evolving, for a large class of materials one can construct a useful first-principles or ``Standard Model`` of solids which is sufficiently robust to explain and predict many physical properties. Both electronic and structural properties can be studied and the results of the first-principles calculations can be used to predict new materials, formulate empirical theories and simple formulae to compute material parameters, and explain trends. A discussion of the microscopic approach, applications, and empirical theories is given here, and some recent results on nanotubes, hard materials, and fullerenes are presented.
Libertarianism and circumcision.

Despite the millenniums-old tradition in Abrahamic circles of removing the foreskin of a penis at birth, the involuntary and aggressive practice of circumcision must not be made an exception to the natural, negative right to self-ownership—a birthright which should prevent a parent from physically harming a child from the moment of birth going forward. This paper will present a natural rights argument against the practice of male child circumcision, while also looking into some of the potential physical and psychological consequences of the practice. It will compare the practice with that of female circumcision, which is banned in developed nations but still practiced in the third world, as well as other forms of aggressive action, some once-prevalent, while disputing arguments made for parental ownership of the child, religious expression, cultural tradition, cleanliness, cosmetics, and conformity.
Envelopes and osculates of Willmore surfaces

We view conformal surfaces in the 4-sphere as quaternionic holomorphic curves in quaternionic projective space. By constructing enveloping and osculating curves, we obtain new holomorphic curves in quaternionic projective space and thus new conformal surfaces. Applying these constructions to Willmore surfaces, we show that the osculating and enveloping curves of Willmore spheres remain Willmore.
Efficient microwave-assisted synthesis of amine-substituted tetrakis(pentafluorophenyl)porphyrin.

We report an efficient and rapid means for the synthesis of tetrakis(pentafluorophenyl)porphyrin (TPPF20) derivatives by microwave irradiation in an environmentally acceptable solvent. The selective displacement of the para-fluorine groups in TPPF20 by primary amines occurs in yields between 70 and 95%. This method demonstrates that TPPF20 is an ideal platform for the rapid formation of porphyrin conjugates for therapeutic, catalytic, and other applications.
Germ Cell Tumors of the Mediastinum and Testis: A Comparative Immunohistochemical Study of 120 Cases

An immunohistochemical study was performed in 120 cases of mediastinal and testicular germ cell tumors from archival, paraffin-embedded material to compare the patterns of expression between the two groups with a panel of markers, including broad-spectrum keratin, CAM 5.2 low-molecular-weight cytokeratin, placental-like alkaline phosphatase (PLAP), alpha-fetoprotein (AFP), human beta-chorionic gonadotropin (hCG), vimentin, and CD30 (Ki-1 antigen). Significant differences were observed between mediastinal and testicular seminomas: mediastinal seminomas showed strong dot-like paranuclear positivity of the tumor cells with antibodies to CAM 5.2 low-molecular-weight keratin in 80% of cases (32 of 40), as compared with only 20% positivity (5 of 24) in testicular seminomas; placental alkaline phosphatase (PLAP) was also found to be less commonly expressed in testicular seminomas (12 of 24) than in mediastinal seminomas (37 of 40); a similar pattern of expression was also observed for vimentin, which was present in scattered tumor cells in a higher proportion of mediastinal seminomas (28 of 40) than in testicular seminomas (11 of 24). The staining pattern and distribution of these markers did not show significant differences between the two groups for the various other tumor categories studied, including yolk sac tumor, embryonal carcinoma, and choriocarcinoma. The tumor cells in both testicular and mediastinal embryonal carcinoma showed strong positivity for the CD30 antigen; however, strong positivity for this marker was also observed in 6 of 25 yolk sac tumors and in scattered individual tumor cells in 4 of 63 seminomas. The results of this study show that significant differences exist between the immunostaining patterns of mediastinal and testicular seminomas, suggesting that the former may be characterized by a more mature phenotype than their testicular counterparts. Also, CD30 expression may not be necessarily restricted to embryonal carcinomas and occasionally may be observed in yolk sac tumors and seminoma cells, supporting the close histogenetic relationship that exists among these tumor types.
Effect of crack blunting on subsequent crack propagation

Theories of toughness of materials depend on an understanding of the characteristic instabilities of the crack tip, and their possible interactions. In this paper the authors examine the effect of dislocation emission on subsequent cleavage of a crack and on further dislocation emission. The work is an extension of the previously published Lattice Greens Function methodology. They have developed a Cavity Greens Function describing a blunt crack and used it to study the effect of crack blunting under a range of different force laws. As the crack is blunted, they find a small but noticeable increase in the crack loading needed to propagate the crack. This effect may be of importance in materials where a dislocation source near the crack tip in a brittle material causes the crack to absorb anti-shielding dislocations, and thus cause a blunting of the crack. It is obviously also relevant to cracks in more ductile materials where the crack itself may emit dislocations.
Redshift-space distortions with the halo occupation distribution - I. Numerical simulations

We show how redshift-space distortions of the galaxy correlation function or power spectrum can constrain the matter density parameter Ω m and the linear matter fluctuation amplitude σ 8 . We improve on previous treatments by adopting a fully non-linear description of galaxy clustering and bias, which allows us to achieve the accuracy demanded by larger galaxy redshift surveys and to break parameter degeneracies by combining large-scale and small-scale distortions. Given an observationally motivated choice of the initial power spectrum shape, we consider different combinations of Ω m and σ 8 and find parameters of the galaxy halo occupation distribution (HOD) that yield nearly identical galaxy correlation functions in real space. We use these HOD parameters to populate the dark matter haloes of large N-body simulations, from which we measure redshift-space distortions on small and large scales. We include a velocity bias parameter α v that allows the velocity dispersions of satellite galaxies in haloes to be systematically higher or lower than those of dark matter. Large-scale distortions are determined by the parameter combination β ≡ Ω 0.6 m /b g , where bg is the bias factor defined by the ratio of galaxy and matter correlation functions, in agreement with the linear theory prediction of parameter degeneracy. However, linear theory does not accurately describe the distortions themselves on scales accessible to our simulations. We provide fitting formulas to estimate β from measurements of the redshift-space correlation function or power spectrum, and we show that these formulas are significantly more accurate than those in the existing literature. On small scales, the 'FOG' distortions at projected separations ∼0.1 h -1 Mpc depend on Ω m α 2 v but are independent of as, while at intermediate separations they depend on σ 8 as well. One can thus use measurements of redshift-space distortions over a wide range of scales to separately determine Ω m , σ 8 , and α v .
Options, the Value of Capital, and Investment

Capital investment decisions must recognize the limitations on the firm's ability to later sell or expand capacity. This paper shows how opportunities for future expansion or contraction can be valued as options, how their valuation relates to the q theory of investment, and their effect on the incentive to invest. Generally, the option to expand reduces the incentive to invest, while the option to disinvest raises it. We show how these options determine the effect of uncertainty on investment, how they are changed by shifts of the distribution of future profitability, and how the q-theory and option pricing approaches are related.