cssi/SciSciGPT-SciSciNet huggingface dataset:
Normalized Range Voting Broadly Resists Control

We study the behavior of Range Voting and Normalized Range Voting with respect to electoral control. Electoral control encompasses attempts from an election chair to alter the participation or structure of an election in order to change the outcome. We show that a voting system resists a case of control by proving that performing that case of control is computationally hard. Range Voting is a natural extension of approval voting, and Normalized Range Voting is a simple variant which alters each vote to maximize the potential impact of each voter. We show that Normalized Range Voting has among the largest known number of control resistances among natural voting systems.
More-or-less CP-networks

Preferences play an important role in our everyday lives. CP-networks, or CP-nets in short, are graphical models for representing conditional qualitative preferences under ceteris paribus ("all else being equal") assumptions. Despite their intuitive nature and rich representation, dominance testing with CP-nets is computationally complex, even when the CP-nets are restricted to binary-valued preferences. Tractable algorithms exist for binary CP-nets, but these algorithms are incomplete for multi-valued CP-nets. In this paper, we identify a class of multi-valued CP-nets, which we call more-or-less CP-nets, that have the same computational complexity as binary CP-nets. More-or-less CP-nets exploit the monotonicity of the attribute values and use intervals to aggregate values that induce similar preferences. We then present a search control rule for dominance testing that effectively prunes the search space while preserving completeness.
Hopfological algebra and categorification at a root of unity: The first steps

Any finite-dimensional Hopf algebra H is Frobenius and the stable category of H-modules is triangulated monoidal. To H-comodule algebras we assign triangulated module-categories over the stable category of H-modules. These module-categories are generalizations of homotopy and derived categories of modules over a differential graded algebra. We expect that, for suitable H, our construction could be a starting point in the program of categorifying quantum invariants of 3-manifolds.
Youth at risk, social exclusion, and intergenerational poverty dynamics : A new survey instrument with application to Brazil

This paper addresses the underlying causes of problems and risks faced by poor and excluded youth of 10-24 years of age. The authors develop a survey instrument that addresses poverty in a broad sense, including hunger, early pregnancy and fatherhood, violence, crime, drug use, low levels of social capital, and low educational attainment. The authors also shed light on intergenerational transfer of risks that are considered to induce poverty. They document findings based on the survey data gathered in three poor urban neighborhoods in Fortaleza in Northeast Brazil. Their main findings show that: (i) Poor youth are at considerable risk of growing up without their father. Only 7 percent grow up with their father present in the household. (ii) The intergenerational transmission of low education attainment is at play, but it is diminishing. (iii) The risk of early pregnancy and fatherhood is large among poor and excluded youth-31 percent of the youth had their first child before age 16, triple that of the adult population. (iv) The risk of sexual abuse and violence within the household exists-6 percent of the youth answered that they had their first sexual relationship with a family member, and 13 percent grow up in households with violence. (v) The social capital levels are low-only 5 percent of the youth and 9 percent of the adults have measurable social capital. (vi) The risk of growing up in a violent neighborhood is large-59 percent of the youth claim that they live in a violent neighborhood, 80 percent feel unsafe in their neighborhood, and 50 percent feel unsafe at home.
ACRE: A Revenue-Based Alternative to Price-Based Commodity Payment Programs

This paper develops a stochastic model for estimating the probability density function of the Average Crop Revenue Election (ACRE), a revenue-based commodity support payment that is offered under the 2008 Farm Act as an alternative to the traditional suite of price-based commodity payments, that is, marketing loan benefits and counter-cyclical payments. We minimize the potential for miss-specification bias in the model by using nonparametric and semi-nonparametric approaches as specification checks in the model. Our simulation results show that adding ACRE revenue payments to gross revenue reduced the downside risk in revenue for corn, wheat, and soybean farmers in 2009 in the four locations examined, with reductions ranging from 4% to 25%. Integrating Federal crop insurance with ACRE lowered insurance premiums from 10% to 40%, depending on the crop and location. A utility maximization approach is used to assess potential moral hazard effects of ACRE, and suggest little potential impact on acreage in the Heartland.
The Good, the Bad, and the Ugly: An inquiry into the causes and nature of credit cycles

This paper builds models of nonlinear dynamics in the aggregate investment and borrower net worth and uses them to study the causes and nature of endogenous credit cycles. The basic model has two types of projects: the Good and the Bad. The Bad is highly productive, but, unlike the Good, it generates less aggregate demand spillovers and contributes little to improve borrower net worth. Furthermore, it is relatively difficult to finance externally due to the agency problem. With a low net worth, the agents cannot finance the Bad, and much of the credit goes to finance the Good, even when the Bad projects are more profitable than the Good projects. This over-investment to the Good creates a boom and generates high aggregate demand spillovers. This leads to an improvement in borrower net worth, which makes it possible for the agents to finance the Bad. This shift in the composition of the credit from the Good to the Bad at the peak of the boom causes a deterioration of net worth. The whole process repeats itself. Endogenous fluctuations occur, as the Good breeds the Bad, and the Bad destroys the Good. The model is then extended to add a third type of the projects, the Ugly, which are unproductive but easy to finance. With a low net worth, the Good competes with the Ugly, creating the credit multiplier effect; with a high net worth, the Good competes with the Bad, creating the credit reversal effect. By combining these two effects, this model generates intermittency phenomena, i.e., relatively long periods of small and persistent movements punctuated intermittently by seemingly random-looking behaviors. Along these cycles, the economy exhibits asymmetric fluctuations; it experiences a long and slow process of recovery from a recession, followed by a rapid expansion, and possibly after a period of high volatility, plunges into a recession.
A Two-Stage Monolithic Buffer Amplifier for 20 GHz Satellite Communication

Design, fabrication, and test results of a two-stage GaAs monolithic buffer amplifier for 20 GHz satellite communication are described in this paper. A gain of 13 +- 0.75 dB from 17.7 to 20.2 GHz was obtained from the 1.5 x 1.5 milli-meter chip, which includes all necessary bias and dc blocking circuitry.
Unionization and Productivity: Evidence from Charter Schools

This paper studies the relationship between teacher unionization and student achievement. Generally stable patterns of teacher unionization since the 1970s have historically presented challenges in measuring the effects of unionization on educational production. However, the blossoming of the charter school sector in recent decades provides fertile ground for study because while most charters are nonunion, teachers at some charters have unionized. Using a generalized difference-in-difference approach combining California union certification data with student achievement data from 2003–2012, we find that, aside from a one-year dip in achievement associated with the unionization process itself, unionization does not affect student achievement.
Survival of the Greenest: A Statistical Analysis of Constitutional Environmental Rights

Why do some countries have constitutional environmental rights while others do not? In this chapter I conduct survival analysis using a Cox regression model on UN-recognized countries over the time period 1983-2010 in order to respond to this inquiry. This section proceeds as follows: (1) I review relevant literature and describe theories which may explain state behavior regarding the adoption of constitutional environmental rights; (2) I conduct statistical tests on five independent variables — International Civil Society Influence, Regional Diffusion, Human Rights Legacy, Natural Resources Dependency, and Monetary Incentives — to determine which factors offer the greatest explanatory value for the phenomenon observed; and (3) I summarize results of the analysis and offer conclusions. I argue that norm socialization and transnational activism offer more explanatory purchase than domestic politics and rationalist-materialist considerations in understanding the trend toward constitutionalization of environmental rights. I find that the enactment of constitutional environmental rights is most significantly associated with International Civil Society Influence and Regime Characteristics, a control variable.
Relativistic Multichannel Scattering Theory with Particle Creation

The creation of a mathematically rigorous multichannel relativistic quantum scattering theory that includes particle creation and annihilation has been an important goal in theoretical physics for many decades. Even in such a thoroughly worked-over field as pion-nucleon physics the goal has remained unrealized [1]. This basic problem is here reexamined from a perspective that is different in some important respects from the main traditional approaches. In particular, it is not a local quantum field theory [2] nor is it based on the Bakamjian-Thomas construction [3].
Scalar Decay in Chaotic Mixing

I review the local theory of mixing, which focuses on infinitesimal blobs of scalar being advected and stretched by a random velocity field. An advantage of this theory is that it provides elegant analytical results. A disadvantage is that it is highly idealised. Nevertheless, it provides insight into the mechanism of chaotic mixing and the effect of random fluctuations on the rate of decay of the concentration field of a passive scalar.
General Purpose Technologies and their Implications for International Trade

General purpose technologies (GPTs) are drastic innovations, such as electrification, the transistor, and the Internet, that are characterized by the pervasiveness in use, innovational complementarities, and technological dynamism. The model develops a two-country (Home and Foreign) dynamic general equilibrium framework and incorporates general purpose technology diffusion within Home that exhibits endogenous Schumpeterian growth. The model studies the effects of the diffusion of the general purpose technology on the pattern of trade and Home’s relative wage. Based on specific assumptions, the adoption of a GPT by a particular industry generates an increase in the productivity of manufacturing workers at Home. By assumption, the diffusion of a GPT across industries is governed by S-curve dynamics, and the diffusion of the GPT within an industry at Home is considered exogenous. The model analyzes the long-run and transitional dynamic effects of a new GPT on the pattern of trade and relative wage between the two countries.
How competitor brand names affect within-brand choices

This research shows that consumers’ intra-brand choices (e.g., Mercedes C330 vs. C340) can be affected by exposure to a competitor alphanumeric brand name that forms an incidental trend with the numbers in the focal brand names (e.g., BMW320i or BMW350i). We propose and test two mechanisms. First, when no attribute information is available, the competitor brand can make the numerical trends formed by brand names salient and meaningful, and increase the preference for higher brands (e.g., Mercedes C340). Second, when attribute values are negatively correlated with brands, exposure to the competitor brand name can trigger brand-attribute magnitude tradeoffs. In five experiments, we demonstrate that our predictions hold when there are no intrinsic brand-attribute associations, and even when the competitor brand is not available for choice. We identify competitive categorization as a boundary condition and demonstrate that the effect diminishes when consumers do not categorize the nonfocal option as a competitor.
The computational complexity of knot genus and spanning area

We investigate the computational complexity of some problems in three-dimensional topology and geometry. We show that the problem of determining a bound on the genus of a knot in a 3-manifold, is NP-complete. Using similar ideas, we show that deciding whether a curve in a metrized PL 3-manifold bounds a surface of area less than a given constant C is NP-hard.
Tropical theta functions and log Calabi–Yau surfaces

We generalize the standard combinatorial techniques of toric geometry to the study of log Calabi–Yau surfaces. The character and cocharacter lattices are replaced by certain integral linear manifolds described in Gross et al. (Math. Inst. Hautes Etudes Sci. 122, 65–168, 2015), and monomials on toric varieties are replaced with the canonical theta functions defined in Gross et al. (2015) using ideas from mirror symmetry. We describe the tropicalizations of theta functions and use them to generalize the dual pairing between the character and cocharacter lattices. We use this to describe generalizations of dual cones, Newton and polar polytopes, Minkowski sums, and finite Fourier series expansions. We hope that these techniques will generalize to higher-rank cluster varieties.
Metallic ferromagnetism: progress in our understanding of an old strong-coupling problem

Metallic ferromagnetism is in general an intermediate to strong coupling phenomenon. Since there do not exist systematic analytic methods to investigate such types of problems, the microscopic origin of metallic ferromagnetism is still not sufficiently understood. However, during the last two or three years remarkable progress was made in this field: It is now certain that even in the one-band Hubbard model metallic ferromagnetism is stable in dimensions d=1, 2, and ∞ on regular lattices and at intermediate values of the interaction U and density n. In this paper, the basic questions and recent insights regarding the microscopic conditions favoring metallic ferromagnetism in this model are reviewed. These findings are contrasted with the results for the orbitally degenerate case.
D-branes in curved space

Michael R. DouglasDepartment of Physics and AstronomyRutgers UniversityPiscataway, NJ 08855–0849mrd@physics.rutgers.eduWe obtain actions for N D-branes occupying points in a manifold with arbitrary Kahlermetric. In one complex dimension, the action is uniquely determined (up to second orderin commutators) by the requirement that it reproduce the masses of stretched strings andby imposing supersymmetry. These conditions are very restrictive in higher dimensions aswell. The results provide a noncommutative extension of Kahler geometry.March 1997
On Sex, Evolution, and the Multiplicative Weights Update Algorithm

We consider a recent innovative theory by Chastain et al. on the role of sex in evolution [10]. In short, the theory suggests that the evolutionary process of gene recombination implements the celebrated multiplicative weights updates algorithm (MWUA). They prove that the population dynamics induced by sexual reproduction can be precisely modeled by genes that use MWUA as their learning strategy in a particular coordination game. The result holds in the environments of weak selection, under the assumption that the population frequencies remain a product distribution.We revisit the theory, eliminating both the requirement of weak selection and any assumption on the distribution of the population. Removing the assumption of product distributions is crucial, since as we show, this assumption is inconsistent with the population dynamics. We show that the marginal allele distributions induced by the population dynamics precisely match the marginals induced by a multiplicative weights update algorithm in this general setting, thereby affirming and substantially generalizing these earlier results.We further revise the implications for convergence and utility or fitness guarantees in coordination games. In contrast to the claim of Chastain et al.[10], we conclude that the sexual evolutionary dynamics does not entail any property of the population distribution, beyond those already implied by convergence.
Productivity Growth and Product Variety : Gains from Imitation and Education

Is there a correlation between productivity and product variety? Certainly it appears that the rich countries are more productive and have more product variety than the poor nations. In fact, the relationship is quite strong when measured in levels. Does this same correlation hold up when measured in growth rates? If so, can poor countries imitate the success of the rich? Addison provides theoretical and empirical reasons to believe the answer to both questions is yes. Recent economic theory suggests that rising variety in factor inputs can help avoid diminishing marginal returns. Product variety can also sustain learning-by-doing which would otherwise be exhausted in a fixed number of products. Finally, invention or imitation adds to the stock of non-rival knowledge. There have been only two previous empirical tests of the correlation between growth in product variety and productivity growth. Both were affirmative but neither examined a wide range of developing countries and neither looked deeper to test what might drive product variety. This research is based on a cross-country sample of 29 countries (13 rich and 16 poor). The data display a statistically significant and positive relationship between growth in product variety and productivity growth when condition on other variables such as research and development (R&D) employment, macroeconomic stability, and domestic security. These results are robust to the addition and subtraction of various explanatory variables but fragile with respect to an influential data point for Venezuela. Industrial nations tend to generate most of their productivity gains through R&D employment in a stable environment that results in better production processes and product quality. In contrast, the largest source of productivity growth in developing countries is product variety imitation while instability takes away from productivity. Addison tests various explanations for growth in variety. The results show that nations furthest from the frontier of observable variety tend to imitate fastest, with the ability to imitate being improved by educational attainment and by productivity gains. This could be a source of hope for small, less developed nations. Growth in market size was not correlated with growth in variety, though this may be due to a rather short sample period of only eight years. In addition to the empirical testing, Addison also contributes to a general discussion of measurement concepts and measurement issues related to product variety and sets out an agenda for further research.
Economics, Psychology, and Sociology of Security

Security is not an isolated good, but just one component of a complicated economy. That imposes limitations on how effective it can be. The interactions of human society and human nature suggest that security will continue being applied as an afterthought. We will have to put up with the equivalent of bailing wire and chewing gum, and to live on the edge of intolerable frustration. However, that is not likely to to be a fatal impediment to the development and deployment of information technology. It will be most productive to think of security not as a way to provide ironclad protection, but the equivalent of speed bumps, decreasing the velocity and impact of electronic attacks to a level where other protection mechanisms can operate.
Endoscopic resection of anterolateral maxillary sinus inverted papillomas

Objectives/Hypothesis Endoscopic medial maxillectomy (EMM) has become the surgical procedure of choice for resection of maxillary sinus inverted papillomas (IPs). Traditionally, IPs pedicled on the anterior and/or lateral walls of the maxillary sinus have required an adjuvant Caldwell-Luc approach due to decreased visualization with transnasal endoscopy in these locations. The objective of the current study is to evaluate outcomes following endoscopic resection of anterolateral maxillary sinus IPs. Study Design Prospective case series. Subjects and Methods Over 6 years, a total of 35 patients underwent EMM for maxillary sinus IPs located on the anterolateral maxillary wall. Demographics, operative technique, pathology, complications, recurrence, and postoperative follow-up were evaluated. Results The majority of patients were male (71%) with a mean age of 56 years (range 27–83). Most patients (71%) were referred for recurrence after previous attempts at surgical resection. Adequate visualization was obtained following EMM in the majority of patients with use of a 70-degree endoscope and angled instrumentation. The addition of transseptal surgical access was critical to the removal of IPs in 16 patients. No Caldwell-Luc approaches were required. Pathologic dysplasia was identified in nine patients, and three had carcinoma. There were no recurrences with a mean disease-free interval of 29 months (10–72 months). Conclusion In the present study, EMM provided excellent surgical access to anterolateral maxillary sinus IPs. The transseptal approach allowed enhanced visualization to this challenging location, previously considered accessible only with external procedures. Level of Evidence 4. Laryngoscope, 125:807–812, 2015
The Role of Type II Spicules in the Upper Solar Atmosphere

We examine the suggestion that most of the hot plasma in the Sun's co rona comes from type II spicule material that is heated as it is ejected from the chromosphere. This contrasts with the traditional view th at the corona is filled via chromospheric evaporation that results fr om coronal heating. We explore the observational consequences of a hy pothetical spicule dominated corona and conclude from the large discr epancy between predicted and actual observations that only a small fraction of the hot plasma can be supplied by spicules (<2% in active regions and <5% in the quiet Sun). The red- blue asymmetries of EUV spec tral lines and the ratio of lower transition region (LTR; T< or =0.1 MK) to coronal emission measures are both predicted to be 2 orders of magnitude larger than observed. Furthermore, hot spicule material would cool dramatically by adiabatic expansion as it rises into the corona, so coronal heating would be required to maintain the high temperatu res that are seen at all altitudes. The necessity of coronal heating is inescapable. Traditional coronal heating models predict far too little emission from the LTR, and we suggest that this emission comes pr imarily from the bulk of the spicule material that is heated to < or =0.1 MK and is visible in He II (304 ?A) as it falls back to the surf ace.
Identifying and Spurring High-Growth Entrepreneurship: Experimental Evidence from a Business Plan Competition

Almost all firms in developing countries have fewer than 10 workers, with the modal firm consisting of just the owner. Are there potential high-growth entrepreneurs with the ability to grow their firms beyond this size? And, if so, can public policy help alleviate the constraints that prevent these entrepreneurs from doing so? A large-scale national business plan competition in Nigeria is used to help provide evidence on these two questions. The competition was launched with much fanfare, and attracted almost 24,000 entrants. Random assignment was used to select some of the winners from a pool of semi-finalists, with US$36 million in randomly allocated grant funding providing each winner with an average of almost US$50,000. Surveys tracking applicants over three years show that winning the business plan competition leads to greater firm entry, higher survival of existing businesses, higher profits and sales, and higher employment, including increases of over 20 percentage points in the likelihood of a firm having 10 or more workers. These effects appear to occur largely through the grants enabling firms to purchase more capital and hire more labor.
Low Energy Transfer to the Moon

In 1991, the Japanese Hiten mission used a low energy transfer with a ballistic capture at the Moon which required less ΔV than a standard Hohmann transfer. In this paper, we apply the dynamical systems techniques developed in our earlier work to reproduce systematically a Hiten-like mission. We approximate the Sun—Earth—Moon-spacecraft 4-body system as two 3-body systems. Using the invariant manifold structures of the Lagrange points of the 3-body systems, we are able to construct low energy transfer trajectories from the Earth which execute ballistic capture at the Moon. The techniques used in the design and construction of this trajectory may be applied in many situations.
An adaptive algorithm for n-body field expansions

An expansion of a density field or particle distribution in basis functions that solve the Poisson equation both provides an easily parallelized N-body force algorithm and simplifies perturbation theories. The expansion converges quickly and provides the highest computational advantage if the lowest order potential-density pair in the basis looks like the unperturbed galaxy or stellar system. Unfortunately, there are only a handful of such bases in the literature that limit this advantage. This paper presents an algorithm for deriving these bases to match a wide variety of galaxy models. The method is based on efficient numerical solution of the Sturm-Liouville equation and can be used for any geometry with a separable Laplacian. Two cases are described in detail. First, for the spherical case, the lowest order basis function pair may be chosen to be exactly that of the underlying model. The profile may be (1) cuspy or have a core and (2) truncated or of infinite extent. Second, the method yields a three-dimensional cylindrical basis appropriate for studying galactic disks. In this case, the vertical and radial bases are coupled; the lowest order radial part of the basis function can be chosen to match the underlying profile only in the disk plane. Practically, this basis is still a very good match to the overall disk profile and converges in a small number of terms. The ease of combining several bases makes this force solver ideally suited to multicomponent simulations, such as those of disks embedded in halos.
Harmonic spinors on homogeneous spaces

Let G be a compact, semi-simple Lie group and H a maximal rank reductive subgroup. The irreducible representations of G can be constructed as spaces of harmonic spinors with respect to a Dirac operator on the homogeneous space G/H twisted by bundles associated to the irreducible, possibly projective, representations of H. Here, we give a quick proof of this result, computing the index and kernal of this twisted Dirac operator using a homogeneous version of the Weyl character formula noted by Gross, Kostant, Ramond, and Sternberg, as well as recent work of Kostant regarding an algebraic version of this Dirac operator.
New Measurement of the Bs Mixing Phase at CDF

The CDF collaboration presents an updated measurement of the CP-violating parameter {beta}{sub s}{sup J/{Psi}{phi}} and of the decay width difference {Delta}{Lambda}{sub s} using approximately 6500 B{sub s} {yields} J/{Psi}{phi} decays collected by the dimuon trigger and reconstructed in a data sample corresponding to 5.2 fb{sup -1} of integrated luminosity. Besides exploiting the two-fold increase in the data sample with respect to the previous measurement, several improvements have been introduced in the analysis including a fully data-driven flavor tagging calibration and proper treatment of possible S-wave contributions. We find that the CP-violating phase is within the range {beta}{sub s}{sup J/{Psi}{phi}} {element_of} [0.02, 0.52] {union} [1.08, 1.55] at 68% C.L. The decay width difference is found to be {Delta}{Lambda}{sub s} = 0.075 {+-} 0.035 (stat) {+-} 0.01 (syst) ps{sup -1}. In addition, we present the most precise mean B{sub s} lifetime {tau}{sub s}, polarization amplitudes |A{sub 0}|{sup 2},|A{sub {parallel}}|{sup 2} and |A{sub {perpendicular}}|{sup 2}, as well as strong phase {delta}{sub {perpendicular}}: {tau}{sub s} = 458.6 {+-} 7.6(stat) {+-} 3.6(syst) {micro}m; |A{sub 0}|{sup 2} = 0.524 {+-} 0.013(stat) {+-} 0.015(syst); |A{sub {parallel}}|{sup 2} = 0.231 {+-} 0.014(stat) {+-} 0.015(syst); and {delta}{sub {perpendicular}} = 2.95 {+-} 0.64(stat) {+-} 0.07(syst).
Nordhaus-Gaddum Theorem for the Distinguishing Chromatic Number

Nordhaus and Gaddum proved, for any graph $G$, that $\chi(G) + \chi(\overline{G}) \leq n + 1$, where $\chi$ is the chromatic number and $n=|V(G)|$. Finck characterized the class of graphs, which we call NG-graphs, that satisfy equality in this bound. In this paper, we provide a new characterization of NG-graphs, based on vertex degrees, which yields a new polynomial-time recognition algorithm and efficient computation of the chromatic number of NG-graphs. Our motivation comes from our theorem that generalizes the Nordhaus-Gaddum theorem to the distinguishing chromatic number. For any graph $G$, $\chi_D(G) +\chi_D(\overline{G})\leq n+D(G)$. We call the set of graphs that satisfy equality in this bound NGD-graphs, and characterize the set of graphs that are simultaneously NG-graphs and NGD-graphs.
Demand-Driven Innovation and Spatial Competition Over Time

The demand-pull hypothesis regarding the process underlying innovation emphasizes a top-down approach. The initiation of an innovation is seen as coming from the firm's marketing or production people and the response as coming from the research staff. The problem may be posed by members of the firm that deal directly with its customers or are involved with the manufacture of its products and a solution is provided by the research staff. The alternative technology-push hypothesis emphasizes a bottom-up approach and has the research staff playing the active role of determining the nature of the innovation, with the marketing and production staff playing a passive role. It seems that neither hypothesis alone can account for the direction of innovative activity-it is the interaction of technological opportunity and economic opportunity that is of ultimate importance. Moreover, technological opportunity is judged to be responsible for the long-run evolution of products, while economic opportunity appears to account for more of the short-run developments (Kamien and Schwartz (1982)).
THE EFFECT OF TRADING FUTURES ON SHORT SALE CONSTRAINTS

It is commonly believed that the trading of futures on a commodity enables the market to overcome short selling constraints on the spot commodity itself. This belief is embedded in the notion that trading strategies involving futures contracts enable traders to replicate the payoffs as if they were short the spot commodity. The purpose of this paper is to investigate this common belief in a general arbitrage-free semimartingale financial model with trading in futures and a short selling prohibition on the spot commodity. We show via various examples that, in general, this common belief is incorrect. Furthermore, we provide a set of sufficient conditions, albeit very restrictive, under which the common belief is true.
New directions in enumerative chess problems

Normally a chess problem must have a unique solution, and is deemed unsound even if there are alternatives that differ only in the order in which the same moves are played. In an enumerative chess problem, the set of moves in the solution is (usually) unique but the order is not, and the task is to count the feasible permutations via an isomorphic problem in enumerative combinatorics. Almost all enumerative chess problems have been "series-movers"$\!$, in which one side plays an uninterrupted series of moves, unanswered except possibly for one move by the opponent at the end. This can be convenient for setting up enumeration problems, but we show that other problem genres also lend themselves to composing enumerative problems. Some of the resulting enumerations cannot be shown (or have not yet been shown) in series-movers.
The Forensic Value of the Windows 7 Jump List

The Windows 7 Jump List is an aspect of the Windows 7 operating system that has the potential to contain data and artifacts of great interest to investigators, but has yet to receive any considerable attention or research. As of this writing, only one published work makes mention of their existence, and no tools exist to automate their retrieval and analysis. The goal of this research is to provide an overview of the function and behavior of jump lists, and also to examine the structure of jump lists with the intention of proposing further research for making use of them in a forensic capacity.
Large-scale Multi-label Learning with Missing Labels

The multi-label classification problem has generated significant interest in recent years. However, existing approaches do not adequately address two key challenges: (a) scaling up to problems with a large number (say millions) of labels, and (b) handling data with missing labels. In this paper, we directly address both these problems by studying the multi-label problem in a generic empirical risk minimization (ERM) framework. Our framework, despite being simple, is surprisingly able to encompass several recent label-compression based methods which can be derived as special cases of our method. To optimize the ERM problem, we develop techniques that exploit the structure of specific loss functions - such as the squared loss function - to obtain efficient algorithms. We further show that our learning framework admits excess risk bounds even in the presence of missing labels. Our bounds are tight and demonstrate better generalization performance for low-rank promoting trace-norm regularization when compared to (rank insensitive) Frobenius norm regularization. Finally, we present extensive empirical results on a variety of benchmark datasets and show that our methods perform significantly better than existing label compression based methods and can scale up to very large datasets such as a Wikipedia dataset that has more than 200,000 labels.
Cooperative benzylic–oxyallylic stabilized cations: regioselective construction of α-quaternary centers in ketone-derived compounds

We describe a novel reactivity of benzylic–stabilized oxyallyl cations towards regioselective construction of carbon quaternary centers. These synthetically useful intermediates were readily generated upon ionization of aryl substituted α-hydroxy methylenol ethers with catalytic, mild Bronsted acid. The emerging unsymmetrical oxyallyl cations were then directly captured by indoles and other nucleophiles with exquisite control of regioselectivity, predictably at the electrophilic carbon bearing the alkyl substituent to produce highly functionalized, value-added enol ethers.
The Economics and Nutritional Impacts of Food Assistance Policies and Programs

Recent evidence on malnutrition and poverty raise important questions on the role of food assistance policies and programs. In this review article, we examine evidence on the economic and nutritional impacts of international food assistance programs (FAPs) and policies. The returns on investments in FAPs are, on average, high but depend considerably on the targeting and cost structures as well as on food quality and role of complementary activities. We disaggregate findings into four classes of recipients. Returns to FAPs are highest for children under two. But, FAPs oriented towards early childhood interventions are less well funded than are interventions aimed at school-age children or at the broader, largely adult population even though available evidence indicates that these latter classes of interventions offer considerably lower average returns in economic, health, and nutrition terms. Nonetheless, FAP effectiveness in achieving any of several objectives varies with a range of key factors, including targeting, additionality, seasonality, timeliness, incentive effects, social acceptability and political economy considerations.
The first detection of spatially resolved mid-infrared scattered light from a protoplanetary disk

We report spatially resolved 11.8 μm images, obtained at the W. M. Keck 10 m telescope, of the protoplanetary disk around the pre-main-sequence star HK Tau B. The mid-infrared morphology and astrometry of HK Tau B with respect to HK Tau A indicate that the flux observed in the mid-infrared from HK Tau B has been scattered off the upper surface of its nearly edge-on disk. This is the first example of a protoplanetary disk observed in scattered light at mid-infrared wavelengths. Monte Carlo simulations of this disk show that the extent (FWHM ~ 05 or ~70 AU) of the scattered light nebula in the mid-infrared is very sensitive to the dust size distribution. The 11.8 μm measurement can be best modeled by a dust grain population that contains grains on the order of 1.5-3 μm in size; grain populations with exclusively submicron grain sizes or power-law size distributions that extend beyond 5 μm cannot reproduce the observed morphology. These grains are significantly larger than those expected in the interstellar medium, implying that grain growth has occurred; whether this growth is a result of dust evolution within the disk itself or had originally occurred within the dark cloud remains an open question.
Versatile control of Plasmodium falciparum gene expression with an inducible protein–RNA interaction

The available tools for conditional gene expression in Plasmodium falciparum are limited. Here, to enable reliable control of target gene expression, we build a system to efficiently modulate translation. We overcame several problems associated with other approaches for regulating gene expression in P. falciparum. Specifically, our system functions predictably across several native and engineered promoter contexts, and affords control over reporter and native parasite proteins irrespective of their subcellular compartmentalization. Induction and repression of gene expression are rapid, homogeneous and stable over prolonged periods. To demonstrate practical application of our system, we used it to reveal direct links between antimalarial drugs and their native parasite molecular target. This is an important outcome given the rapid spread of resistance, and intensified efforts to efficiently discover and optimize new antimalarial drugs. Overall, the studies presented highlight the utility of our system for broadly controlling gene expression and performing functional genetics in P. falciparum.
Uncoupling of oxidative phosphorylation.

Abstract The mechanism of oxidative phosphorylation is one of the most important problems in classical biochemistry, which has defied a solution for over thirty years. Uncouplers are powerful tools in the study of the coupling between oxidation and phosphorylation, and recent studies of photo-affinity labeling and equilibrium binding by uncouplers have contributed new insights into this problem.
A Local Clustering Algorithm for Connection Graphs

We give a clustering algorithm for connection graphs, that is, weighted graphs in which each edge is associated with a d-dimensional rotation. The problem of interest is to identify subsets of small Cheeger ratio and which have a high level of consistency, i.e. that have small edge boundary and the rotations along any distinct paths joining two vertices are the same or within some small error factor. We use PageRank vectors as well as tools related to the Cheeger constant to give a clustering algorithm that runs in nearly linear time.
Indium and zinc mediated one-atom carbocycle enlargement in water

Abstract Six-, seven-, eight-membered rings are enlarged by one carbon-atom into seven-, eight- and nine-membered ring derivatives respectively, via indium or zinc mediated reactions in aqueous medium.
Design and Synthesis of Bifunctional Amino Phosphonic Haptens for Catalytic Antibody Production

Abstract Bifunctional amino phosphonic haptens were designed to mimic Soman structurally and were synthesized and conjugated to carrier proteins for the generation of monoclonal antibodies.
Assessment of Three-Dimensional Inviscid Codes and Loss Calculations for Turbine Aerodynamic Computations

An assessment of several three dimensional inviscid turbine aerodynamic computer codes and loss models used at the NASA Lewis Research Center is presented. Five flow situations are examined, for which both experimental data and computational results are available. The five flows form a basis for the evaluation of the computational procedures. It was concluded that stator flows may be calculated with a high degree of accuracy, whereas, rotor flow fields are less accurately determined. Exploitation of contouring, leaning, bowing, and sweeping will require a three dimensional viscous analysis technique.
Storing text retrieval systems on CD-ROM: compression and encryption considerations

The emergence of the CD-ROM as a storage medium for full-text databases raises the question of the maximum size database that can be contained by this medium. As an example, the problem of storing the Tresor de la Langue Francaise on a CD-ROM is examined in this paper. The text alone of this database is 700 megabytes long, more than a CD-ROM can hold. In addition, the dictionary and concordance needed to access these data must be stored. A further constraint is that some of the material is copyrighted, and it is desirable that such material be difficult to decode except through software provided by the system. Pertinent approaches to compression of the various files are reviewed, and the compression of the text is related to the problem of data encryption: Specifically, it is shown that, under simple models of text generation, Huffman encoding produces a bit-string indistinguishable from a representation of coin flips.
Aromatic hydroxylations by flavins : evidence on direct attack of phenylalanine by flavin radical species

Abstract In 0.05–12.0 N acidic solutions, the 5-ethyl-3-methyllumiflavosemiquinone 5 (and/or 5H + ) spontaneously arose from the corresponding flavinium cation 4 . Raising the temperature from 20 to 50°C, considerably increased the reaction rates with no significant changes in the yields of 5 ( 5H + ). The spontaneous one-electron reduction of 4 requires a coupling with a one-electron oxidation of another flavin such as 5-ethyl-4 a -hydroxy-3-methyl-4 a ,5-dihydroflavin pseudobase 1 . The latter, being in equilibrium with 4 , can be oxidized to give the transient 5-ethyl-4 a -hydroxy-3-methyllumiflavin radical 2 . This is the protonated form of a flavinoxy radical 3 a,b , a product of a homolysis of the OO bond in a dihydroflavin hydroperoxide. As an alternative to the homolysis mentioned, the one-electron oxidation of 1 provides the principle to develop a new hydroxylating model system that does not require a dihydroflavin hydroperoxide as a starting compound. Using phenylalanine as a test substrate, the anaerobic formation of tyrosine and its o - and m -hydroxyphenylalanine isomers was established. This achievement is a strong experimental support for the hypothesis that flavin radical species like 2 may directly attack an aromatic. Evidence was obtained on some accumulation of an intermediate that is not a hydroxycyclohexadienyl radical. It was shown to react in a secondary, oxidative chain reaction, remarkably increasing the yields of aromatic hydroxylation without any further supply of flavin.
Malliavin calculus for difference approximations of multidimensional diffusions: Truncated local limit theorem

The truncated local limit theorem is proved for difference approximations of multidimensional diffusions. Under very mild conditions on the distributions of difference terms, this theorem states that the transition probabilities of these approximations, after truncation of some asymptotically negligible terms, possess densities uniformly convergent to the transition probability density for the limiting diffusion and satisfy certain uniform diffusion-type estimates. The proof is based on a new version of the Malliavin calculus for the product of a finite family of measures that may contain nontrivial singular components. Applications to the uniform estimation of mixing and convergence rates for difference approximations of stochastic differential equations and to the convergence of difference approximations of local times for multidimensional diffusions are presented.
The isomolecular exchange reaction Ga2S(g) + In2S(g) = 2 InGaS(g)

Abstract Equilibria involving the molecules Ga 2 S(g), In 2 S(g), and InGaS(g), by the reaction Ga 2 S(g) + In 2 S(g) = 12InGaS(g) were investigated between 1060–1350 K by the Knudsen-effusion, mass-spectrometric method. The reaction enthalpy at 298 K was calculated to be 0±1 kJ mol −1 . The enthalpy of formation of InGaS at 298 K and the enthalpy of atomization of InGaS at 298 K were calculated to be 80±18 kJ mol −1 and 710±18 kJ mol −1 , respectively. The equilibrium constant and the enthalpy of reaction indicated that the three gaseous molecules have a bent triatomic structure in which S is a center atom and no bond between metals.
The relative Hochschild-Serre spectral sequence and the Belkale-Kumar product

We consider the Belkale-Kumar cup product $\odot_t$ on $H^*(G/P)$ for a generalized flag variety $G/P$ with parameter $t \in \C^m$, where $m=\dim(H^2(G/P))$. For each $t\in \C^m$, we define an associated parabolic subgroup $P_K \supset P$. We show that the ring $(H^*(G/P), \odot_t)$ contains a graded subalgebra $A$ isomorphic to $H^*(P_K/P)$ with the usual cup product, where $P_K$ is a parabolic subgroup associated to the parameter $t$. Further, we prove that $(H^*(G/P_K), \odot_0)$ is the quotient of the ring $(H^*(G/P), \odot_t)$ with respect to the ideal generated by elements of positive degree of $A$. We prove the above results by using basic facts about the Hochschild-Serre spectral sequence for relative Lie algebra cohomology, and most of the paper consists of proving these facts using the original approach of Hochschild and Serre.
Microwave-Assisted NBS Bromination of p-Iminotoluenes: Preparation of New Alcohol, Mercapto, and Amino Protection Groups

Abstract A simple, efficient, safe, high-yielding and rapid microwave-assisted method for the preparation of protected p-bromomethyl and p-dibromomethylanilines was developed as new alcohol, thiol, and amine protection groups. The procedure involves microwave-assisted N-bromosuccinimide (NBS) radical bromination of readily available N-protected p-toluidine. The microwave-assisted radical bromination was found to be superior to the conventional NBS radical bromination.
Heterogeneity, Efficiency and Asset Allocation with Endogenous Labor Supply: The Static Case

We study the implications of consumption and labor allocations with ex ante e⁄ciency and possibly ex post ine⁄ciency on international/ interregional portfolio diversi¢cation. The answers we obtain depend crucially on the market regime relative to unemployment insurance. If there are complete markets for unemployment insurance, changes in asset allocation are small in the presence of ex post ine⁄ciency, but if there are incomplete markets for unemployment insurance, changes in asset allocation can be large. The direction of the asset movement is towards more diversi¢cation.