cssi/SciSciGPT-SciSciNet huggingface dataset:
TURBULENCE AND GALACTIC STRUCTURE

Interstellar turbulence is driven over a wide range of scales by processes including spiral arm instabilities and supernovae, and it affects the rate and morphology of star formation, energy dissipation, and angular momentum transfer in galaxy disks. Star formation is initiated on large scales by gravitational instabilities which control the overall rate through the long dynamical time corresponding to the average ISM density. Stars form at much higher densities than average, however, and at much faster rates locally, so the slow average rate arises because the fraction of the gas mass that forms stars at any one time is low, ~ 10−4. This low fraction is determined by turbulence compression, and is apparently independent of specific cloud formation processes which all operate at lower densities. Turbulence compression also accounts for the formation of most stars in clusters, along with the cluster mass spectrum, and it gives a hierarchical distribution to the positions of these clusters and to star-forming regions in general. Turbulent motions appear to be very fast in irregular galaxies at high redshift, possibly having speeds equal to several tenths of the rotation speed in view of the morphology of chain galaxies and their face-on counterparts. The origin of this turbulence is not evident, but some of it could come from accretion onto the disk. Such high turbulence could help drive an early epoch of gas inflow through viscous torques in galaxies where spiral arms and bars are weak. Such evolution may lead to bulge or bar formation, or to bar re-formation if a previous bar dissolved. We show evidence that the bar fraction is about constant with redshift out to z = 1, and model the formation and destruction rates of bars required to achieve this constancy. Bar dissolution has to be accompanied by rapid bar reformation to get the constant bar fraction. This reformation is consistent with numerical simulations by Block et al. (2002), but it may not be possible according to models by Regan & Teuben (2004). The difference between these simulations is partly the result of a difference in the two models for gas viscosity, which depends on the approximations used to represent turbulence. In the Regan & Teuben model, a constant observed bar fraction implies that bars do not dissolve significantly in a Hubble time.
Mechanics of Pipe Flow Following Column Separation

Study of motion of vapor-liquid interface by neglecting its spreading under influence of gravity and of its spreading, considering steam column in straight portion of pipe; it is found that occurrence of collapse of steam column depends on elevation of point of separation, slope of pipe, and velocity of flow at separation; spreading of interface is described by 2 quasi-linear partial differential equations that are hyperbolic.
Justifications for logic programs under answer set semantics

The paper introduces the notion of off-line justification for Answer Set Programming (ASP). Justifications provide a graph-based explanation of the truth value of an atom w.r.t. a given answer set. The notion of justification accounts for the specifics of answer set semantics. The paper extends also this notion to provide justification of atoms during the computation of an answer set (on-line justification), and presents an integration of on-line justifications within the computation model of Smodels. Justifications offer a basic data structure to support methodologies and tools for debugging answer set programs. A preliminary implementation has been developed in $\mathbb{ASP-PROLOG}$.
Concerning the Primordial Abundance of Helium in Quasi-Stellar Sources

Primordial temperature fluctuations, which appear to be necessary in order to explain aspects of galaxy formation, can lead to observable effects in some objects. In QSS and other compact systems a correlation of absolute luminosity with primordial helium content is predicted.
WIC PARTICIPATION AND THE NUTRIENT INTAKE OF PRESCHOOLERS

Quantile regression is used to evaluate the effect of WIC participation on the nutrient intakes of WIC-eligible preschoolers. Estimates based on 1994-96, 1998 CSFII data show that the WIC effects vary by quantile for iron and zinc while the effects are equal across quantiles for calcium.
Corporate Risk Analysis: A Reckless Act?

Balancing of risk and cost lies at the heart of standard negligence tests and policy analysis approaches to government regulation. Notwithstanding the desirability of using a benefit-cost approach to assess the merits of safety measures, in many court cases juries appear to penalize corporations for having done a risk analysis in instances in which the company decided not to make a safety improvement after the analysis indicated the improvement was unwarranted. Automobile accident cases provide the most prominent examples of such juror sanctions. This paper tests the effect of corporate risk analyses experimentally by using a sample of almost 500 juror-eligible citizens. Each individual considered an automobile accident scenario, but these scenarios differed in terms of whether the company undertook a risk analysis and in terms of the nature of the risk analysis. Somewhat surprisingly, even sound benefit-cost analyses of safety measures did not reduce the likelihood of punitive damages. If a company follows the procedures used by government agencies and uses a higher value of life in its analyses, the penalty levied on the corporation increases. Internal use of higher value of life numbers serves as an anchor that boosts rather than reduces jury awards.
The special Schubert calculus is real

We show that the Schubert calculus of enumerative geometry is real, for special Schubert conditions. That is, for any such enumerative problem, there exist real conditions for which all the a priori complex solutions are real. Fulton asked how many solutions to a problem of enumerative geometry can be real, when that problem is one of counting geometric figures of some kind having specified position with respect to some general fixed figures [5]. For the problem of plane conics tangent to five general conics, the (surprising) answer is that all 3264 may be real [10]. Recently, Dietmaier has shown that all 40 positions of the Stewart platform in robotics may be real [2]. Similarly, given any problem of enumerating lines in projective space incident on some general fixed linear subspaces, there are real fixed subspaces such that each of the (finitely many) incident lines are real [13]. Other examples are shown in [12, 14], and the case of 462 4-planes meeting 12 general 3-planes in R is due to an heroic symbolic computation [4]. For any problem of enumerating p-planes having excess intersection with a collection of fixed planes, we show there is a choice of fixed planes osculating a rational normal curve at real points so that each of the resulting p-planes is real. This has implications for the problem of placing real poles in linear systems theory [1] and is a special case of a far-reaching conjecture of Shapiro and Shapiro [15]. Special Schubert conditions For background on the Grassmannian, Schubert cycles, and the Schubert calculus, see any of [8, 7, 6]. Let m, p ≥ 1 be integers. Let γ be a rational normal curve in R. For k > 0 and s ∈ γ, let Kk(s) be the k-plane osculating γ at s. For every integer a > 0, let τa(s) be the special Schubert cycle consisting of pplanes H in C which meet Km+1−a(s) nontrivially, and let τ(s) be the special Schubert cycle consisting of p-planes H in C meeting Km−1+a(s) improperly: dim H ∩Km−1+a(s) > a− 1. These cycles τa(s) and τ(s) each have codimension a and τ = τ1. Recall that the Grassmannian of p-planes in C has dimension Received by the editors December 20, 1998. 1991 Mathematics Subject Classification. Primary 14P99, 14N10, 14M15, 14Q20; Secondary 93B55.
The Impact of Firm Characteristics on Trading Volume Reaction to the Earnings Reconciliation from IFRS to U.S. GAAP

The U.S. SEC voted in November 2007 to accept financial statements prepared under IFRS as issued by the IASB without reconciliation to U.S. GAAP for foreign firms. We find that earnings reconciliation from IFRS to U.S. GAAP is positively and significantly associated with abnormal trading volume in the U.S. markets around the release of earnings reconciliation from 2005 to 2006. However, the relation between abnormal trading volume and earnings reconciliation during this period is driven by first-time IFRS users with low institutional holdings. In addition, we do not find any evidence that such a relation depends upon whether a firm applies IFRS as issued by the IASB or jurisdictional versions of IFRS. Extending our sample to 1995-2006 period, we document that the information content of earnings reconciliation is smaller for firms with high institutional holdings than for firms with low institutional holdings. Overall, our evidence provides some insight to the SEC when evaluating its decision to eliminate the reconciliation and contemplating to allow the use of IFRS by U.S. domestic firms.
Synthesis, Structure, and Bonding of Sc4MgxCu15 - xGa∼7.5 (x = 0, 0.5). Two Incommensurately Modulated Scandium Substitution Derivatives of Cubic Mg2Cu6Ga5

The substitution of scandium for magnesium in Mg2Cu6Ga5 (Mg2Zn11-type) yields an irrational superstructure phase that includes the refined compositions, Sc4Mg0.50(2)Cu14.50(2)Ga7.61(2) and Sc4Cu14.76(2)Ga7.51(2). These crystallize in Cmmm, a=approximately 8.31 A, b=approximately 21.72 A, c=approximately 8.30 A. The structures feature Sc2 dimers, Cu6 octahedra, a 3D CuGa (Cu12Ga2) framework, and arachno gallium-centered Cu4Ga6 icosahedra that are condensed into zigzag chains. The arrangement of these building blocks exhibits a topologic relationship to Mg2Cu6Ga5. Further studies reveal that the quaternary compound exhibits incommensurate modulations along a, with q=(0.694, 0, 0). Structure refinements with superspace group Xmmm(a00)000 led to saw-tooth modulations for two fractional or mixed sites that avoid short Cu-Ga distances. Band structure analyses reveal that the Fermi surface and bonding are sensitive to the incommensurately modulated atoms.
Determining an Optimal Penetration Among Weighted Regions in Two and Three Dimensions

We present efficient algorithms for solving the problem of computing an optimal penetration (a ray or a semi-ray) among weighted regions in 2-D and 3-D spaces. This problem finds applications in several areas, such as radiation therapy, geological exploration, and environmental engineering. Our algorithms are based on a combination of geometric techniques and optimization methods. Our geometric analysis shows that the d-D (d = 2, 3) optimal penetration problem can be reduced to solving O(n 2(d−1)) instances of certain special types of non-linear optimization problems, where n is the total number of vertices of the regions. We also give implementation results of our 2-D algorithms.
Status of the VERITAS Observatory

VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for gammma‐ray astronomy in the GeV‐TeV range, has recently completed its first season of observations with a full array of four telescopes. A number of astrophysical gamma‐ray sources have been detected, both galactic and extragalactic, including sources previously unknown at TeV energies. We describe the status of the array and some highlight results, and assess the technical performance, sensitivity and shower reconstruction capabilities.
Scapegoating the Poor: Welfare Reform All over Again and the Undermining of Democratic Citizenship

In the main body of this article, I focus on AFDC as a symbolic political issue, in particular, the symbolic appeal of what I have referred to as the subtexts of welfare reform. My purpose is to highlight how and why welfare reform, as a framing of policies regarding social and economic support for poor families, is an especially powerful displacement of conflicts political strategy. In the concluding section, I briefly address the inchoate nature of social rights in the evolution of democratic citizenship in America. At this juncture in our political history, nothing beneficial for the poor-or any of us--can come from what we now call welfare reform. We need to pay the most attention to the structural causes of poverty, especially the unavailability of jobs paying a living wage. We also need to think creatively about how to build on our liberal, constitutional heritage of individual rights so that social rights, along with civil and political rights, become an institutionalized and integral part of our concept of citizenship, and, consequently, they will become a meaningful resource in our attempts to protect individuals, not only from arbitrary goyernment, but also from a capricious society and economy.
Some Varieties of Qualitative Probability

In this essay I present a general characterization of qualitative probability, defining the concept of a qualitative probability language and proposing some bases for comparison. In particular, enumerating some of the distinctions that can be supported by a qualitative probability language induces a partial taxonomy of possible approaches. I discuss some of these in further depth, identify central issues, and suggest some general comparisons.
Quark mass renormalization with non-exceptional momenta

Renormalization conditions imposed on quark bilinear vertex functions in the conventional RI/MOM scheme use exceptional momentum configurations. With practical values for the lattice cutoff, these vertex functions are contaminated with unwanted low energy physics (pion pole, zero modes, etc), which is a large source of systematic error. These effects can be reduced by using non-exceptional momenta. We discuss the quark mass renormalization with non-exceptional momenta using 2+1 flavor domain wall fermions based on a recen tly proposed RI/SMOM scheme.
A Comparison of Products in Hochschild Cohomology

In this paper we transport Steenrod's cup-i products, i ≥ 0, from the singular cochains on the free loop space Maps(S1, BG) to Hochschild's original cochain complex Homk(k[G]⊗*, k[G]) defining Hochschild cohomology. Here G is a discrete group, k an arbitrary (commutative) coefficient ring, and BG the classifying space of G. This induces a natural action of the (mod 2) Steenrod algebra on the Hochschild cohomology of a group ring. For cochains supported on BG, we prove that Gerstenhaber's cup product agrees with the simplicial cup product and Gerstenhaber's pre-Lie product agrees with Steenrod's cup-one product. As a consequence, for cocycles f and g supported on BG, the Gerstenhaber bracket [f, g] = 0 in HH*(k[G]; k[G]). This is interpreted in terms of the Batalin–Vilkovisky structure on HH*(k[G]; k[G]).
Black holes, branes and superconformal symmetry

The main focus of this lecture is on extended objects in adS p+2×S d—p—2 bosonic backgrounds with unbroken supersymmetry. The backgrounds are argued to be exact, special consideration are given to the non-maximal supersymmetry case. The near horizon superspace construction is explained. The superconformal symmetry appears in the worldvolume actions as the superisometry of the near horizon superspace, like the superPoincare symmetry of GS superstring and BST supermembrane in the flat superspace. The issues in gauge fixing of local kappa-symmetry are reviewed.
Limitations in predicting student performance on standardized tests

The Maryland Physics Expectations Survey (MPEX) describes student attitudes and expe ctations toward leaning, and might be used to predict normalized gains on tests such as the Force and Motion Concept Evaluation (FMCE). These predictions are incomplete, though, due to limitations of the standardized tests themselves. I illustrate the problems involved in using the MPEX to predict productive attitudes toward learning physics by focusing on two students, both with seemingly appropriate expectations toward learning. While one had high normalized gains, the other did not, due to "false favorable" responses on the MPEX.
The Rogers-Ramanujan identities, the finite general linear groups, and the Hall-Littlewood polynomials

We connect Gordon's generalization of the Rogers-Ramanujan identities with the Hall-Littlewood polynomials and with generating functions which arise in a probabilistic setting in the finite general linear groups. This yields a Rogers-Ramanujan type product formula for the n -+ oo probability that an element of GL(n, q) or Mat(n, q) is semisimple. 1. BACKGROUND AND NOTATION The Rogers-Ramanujan identities are among the most remarkable partition identities in number theory and combinatorics. This paper will be concerned with the following generalization of the Rogers-Ramanujan identities, due to Gordon. Let (x)n denote (1 x)(1 x2)... (1 xn). Theorem 1 ([A, page 111]). For 1 2, and complex x with Ixl O )*'' r0,?i(mod 2k+l) where Nj = nj + + nk-1. Gordon's generalization of the Rogers-Ramanujan identities has been widely studied and appears in many places in mathematics and physics. Andrews [A] discusses combinatorial aspects of these identities. In an important series of papers, Lepowsky and Wilson [LW1], [LW2], [LW3] connect the Gordon identities with affine Lie algebras and structures that they called Z-algebras (later interpreted as parafermion algebras in conformal field theory). Meurman and Primc [MP] solve a problem left open in [LW3], proving the independence of a Z-algebra basis and obtaining a Z-algebra proof of the Gordon identities. Feigin and Frenkel [FF] interpret the Gordon identities as a character formula for the Virasoro algebra. Andrews, Baxter, and Forrester [ABF] and Warnaar [W] relate the Gordon identities with statistical mechanics. For some number theoretic connections see the conference proceedings [AABRR]. We use the following standard notation from the theory of partitions. Call A = (A1,A2,--.) a partition of n = AIX if A1 > A2 > > 0 where the Ai are Received by the editors March 6, 1998. 1991 Mathematics Subject Classification. Primary 20P05, 05E05. ()1999 American Mathematical Society 17 This content downloaded from 207.46.13.142 on Sat, 28 May 2016 06:40:23 UTC All use subject to http://about.jstor.org/terms
Synthesis and characterization of P2N3 −: An aromatic ion composed of phosphorus and nitrogen

Aromaticity is predominantly associated with carbon-rich compounds but can also occur in all-inorganic ones. We report the synthesis of the diphosphatriazolate anion, a rare example of a planar aromatic inorganic species. Treatment of azide (N3(-)) in tetrahydrofuran solution with P2A2 (A = C14H10), a source of P2, produced P2N3(-), which we isolated as its [Na-kryptofix-221](+) salt in 22% yield and characterized by single-crystal x-ray diffraction. Salts [Na-kryptofix-221] [P2N3] and [Na-kryptofix-221] [P2(15)NN2] were analyzed by infrared and Raman spectroscopy, (15)N and (31)P nuclear magnetic resonance spectroscopy, and mass spectrometry. The formation of the P2N3(-) anion was investigated using density functional theory, and its aromatic character was confirmed by NICS (nucleus-independent chemical shift) and QTAIM (quantum theory of atoms in molecules) methods.
CP-Violating Electron-Nucleon Interactions and CP-Violation Beyond the Standard Model

We review and discuss CPT invariant, CP- and P-violating electron-quark interactions in extensions of the Standard Model.
Measuring executive function in early childhood: A case for formative measurement.

This study tested whether individual executive function (EF) tasks were better characterized as formative (causal) or reflective (effect) indicators of the latent construct of EF. EF data that were collected as part of the Family Life Project (FLP), a prospective longitudinal study of families who were recruited at the birth of a new child (N = 1292), when children were 3, 4, and 5 years old. Vanishing tetrad tests were used to test the relative fit of models in which EF tasks were used as either formative or reflective indicators of the latent construct of EF in the prediction of intellectual ability (at age 3), attention deficit/hyperactivity disorder symptoms (at ages 3–5 years), and academic achievement (at kindergarten). Results consistently indicated that EF tasks were better represented as formative indicators of the latent construct of EF. Next, individual tasks were combined to form an overall measure of EF ability in ways generally consistent with formative (i.e., creating a composite mean score) and reflective (i.e., creating an EF factor score) measurement. The test-retest reliability and developmental trajectories of EF differed substantially, depending on which overall measure of EF ability was used. In general, the across-time stability of EF was markedly higher, perhaps implausibly high, when represented as a factor score versus composite score. Results are discussed with respect to the ways in which the statistical representation of EF tasks can exert a large impact on inferences regarding the developmental causes, course, and consequences of EF. More generally, these results exemplify how some psychological constructs may not conform to conventional measurement wisdom.
Status of The US Long Baseline Neutrino Experiment Study

The US Long Baseline Neutrino Experiment Study was commissioned jointly by Brookhaven National Laboratory and Fermi National Accelerator Laboratory to investigate the potential for future U.S. based long baseline neutrino oscillation experiments beyond the currently planned program. The Study focused on MW class conventional neutrino beams that can be produced at Fermilab or BNL. The experimental baselines are based on two possible detector locations: 1) off‐axis to the existing Fermilab NuMI beamline at baselines of 700 to 810 km and 2) NSF's proposed future Deep Underground Science and Engineering Laboratory (DUSEL) at baselines greater than 1000 km. Two detector technologies are considered: a megaton class Water Cherenkov detector deployed deep underground at a DUSEL site, or a 100 kT Liquid Argon Time‐Projection Chamber (TPC) deployed on the surface at any of the proposed sites. The physics sensitivities of the proposed experiments are summarized. We find that conventional horn focused wide‐band neutr...
Synthesis and crystal structure of Bi6.4Pb0.6P2O15.2: A new polymorph in the series Bi6+xM1−xP2O15+y

Abstract Bi 6.4 Pb 0.6 P 2 O 15.2 is a polymorph of structures with the general stoichiometry Bi 6+ x M 1− x P 2 O 15+ y . However, unlike previously published structures that consist of layers formed by edge sharing OBi 4 tetrahedra bridged by PO 4 and TO 6 ( T =transition metal) tetrahedra and octahedra the title compound's structure is more complex. It is monoclinic, C 2, a =19.4698(4) A, b =11.3692(3) A, c =16.3809(5) A, β =101.167(1)°, Z =10. Single-crystal X-ray diffraction data were refined by least squares on F 2 converging to R 1 =0.0387, w R 2 =0.0836 for 7023 intensities. The crystal twins by mirror reflection across (001) as the twin plane and twin component 1 equals 0.74(1). Oxygen ions are in tetrahedral coordination to four metal ions and the O(BiPb) 4 units share corners to form layers that are part of the three-dimensional framework. Eight oxygen ions form a cube around the two crystallographically independent Pb ions. Pb–O bond lengths vary from 2.265(14) to 2.869(14) A. Pairs of such cubes share an edge to form a Pb 3 O 20 unit. The two oxygen ions from the unshared edges are part of irregular Bi polyhedra. Other oxygen ions of Bi polyhedra are part only of O(BiPb) 4 units, and some oxygen ions of the polyhedra are also part of PO 4 tetrahedra. One, two, three and or four PO 4 moieties are connected to the Bi polyhedra. Bi–O bond lengths ⩽3.1 A vary from 2.090(12) to 3.07(3) A. The articulations of Pb cubes, Bi polyhedra and PO 4 tetrahedra link into the three-dimensional structure.
Disks Around Young Binary Stars

Multiple star systems provide a complicated mix of conditions for planet formation. Whereas circumstellar disks around single stars are likely routine sites for planet formation, binary systems can have circumprimary (around the more massive star), circumsecondary (around the less massive star), and circumbinary (around both stars) disks. These heterogeneous locations can provide opportunities as well as hazards.
Star Formation and the X-Ray Background

The potential contribution of massive x-ray binaries to the 3–20 key X-ray background has largely been ignored heretofore. It is pointed out that such objects, in the wake of star formation, can contribute at least as much as quasars to the x-ray background, while solving the problems of spectral shape and sky surface density.
The Solar Flare Myth in Solar‐Terrestrial Physics

Early observations of associations between solar flares and large non- recurrent geomagnetic storms, large {open_quote}solar{close_quote} energetic particle events, and transient shock wave disturbances in the solar wind led to a paradigm of cause and effect that gave flares a central position in the chain of events leading from solar activity to major transient disturbances in the near-earth space environment. However, research in the last two decades shows that this emphasis on flares is misplaced. In this paper the author outlines briefly the rationale for a different paradigm of cause and effect in solar- terrestrial physics that removes solar flares from their central position as the {open_quote}cause{close_quote} of major disturbances in the near-earth space environment. Instead, this central role of {open_quote}cause{close_quote} is played by events now known as coronal mass ejections, or CMEs.
Asteroid Spectroscopy and Mineralogy

Spectroscopic observations of asteroids of smaller sizes and in the near-infrared have led to many exciting discoveries that have increased substantially our knowledge of the mineralogy of asteroids. These discoveries include the identification of hydrated M and E-asteroids, the mineralogical diversity of the S-class, anomalous S-asteroids, a possible source body of the aubrites, Vesta-like objects in the main belt, possible ordinary chondrite-like objects and one of the reddest objects in the solar system.
Slowing Down Sorting Networks to Obtain Faster Sorting Algorithms

Megiddo introduced a technique for using a parallel algorithm for one problem to construct an efficient serial algorithm for a second problem. We give a general method that trims a factor o f 0(logn) time (or more) for many applications of this technique.
Estimating random variables from random sparse observations

Let X 1 ,...., X n be a collection of iid discrete random variables, and Y 1 ,...., Y m a set of noisy observations of such variables. Assume each observation Y a to be a random function of a random subset of the X i s, and consider the conditional distribution of X i given the observations, namely μ i (x i ) = P{X i = x i |Y} (a posteriori probability). We establish a general decoupling principle among the X i s, as well as a relation between the distribution of μ i , and the fixed points of the associated density evolution operator. These results hold asymptotically in the large system limit, provided the average number of variables an observation depends on is bounded. We discuss the relevance of our result to a number of applications, ranging from sparse graph codes and multi-user detection, to group testing.
Nonlinear mirror based on two-photon absorption

The use of semiconductor nonlinear devices for passively mode-locking lasers (e.g. Ti:sapphire, Cr:LiSrAlF6) has been the subject of a great deal of research activity.
On the growth of Stanley sequences

From an initial list of nonnegative integers, we form a Stanley sequence by recursively adding the smallest integer such that the list remains increasing and no three elements form an arithmetic progression. Odlyzko and Stanley conjectured that every Stanley sequence ( a n ) satisfies one of two patterns of asymptotic growth, with no intermediate behavior possible. Sequences of Type 1 satisfy α / 2 ? lim inf n ? ∞ a n / n log 2 3 ? lim sup n ? ∞ a n / n log 2 3 ? α , for some constant α , while those of Type 2 satisfy a n = ? ( n 2 / log n ) . In this paper, we consider the possible values for α in the growth of Type 1 Stanley sequences. Whereas Odlyzko and Stanley considered only those Type 1 sequences for which α equals 1, we show that α can in fact be any rational number that is at least 1 and for which the denominator, in lowest terms, is a power of 3.
The decision-theoretic interactive video advisor

The need to help people choose among large numbers of items and to filter through large amounts of information has led to a flood of research in construction of personal recommendation agents. One of the central issues in constructing such agents is the representation and elicitation of user preferences or interests. This topic has long been studied in Decision Theory, but surprisingly little work in the area of recommender systems has made use of formal decision-theoretic techniques. This paper describes DIVA, a decision-theoretic agent for recommending movies that contains a number of novel features. DIVA represents user preferences using pairwise comparisons among items, rather than numeric ratings. It uses a novel similarity measure based on the concept of the probability of conflict between two orderings of items. The system has a rich representation of preference, distinguishing between a user's general taste in movies and his immediate interests. It takes an incremental approach to preference elicitation in which the user can provide feedback if not satisfied with the recommendation list. We empirically evaluate the performance of the system using the EachMovie collaborative filtering database.
Charged Higgs production via bg⟶tH− at the LHC

I present a calculation of QCD radiative corrections to charged Higgs production via the process bgtH−. I show that the cross section is dominated by soft-gluon corrections, which are computed through next-to-next-to-leading order. Results for charged Higgs production at the LHC are presented, including the dependence of the cross section on the charged Higgs mass, the top quark mass, the factorization and renormalization scales, and tan β.
Relic High Frequency Gravitational waves from the Big Bang and How to Detect Them

This paper shows how entropy generation from numerical density calculations of relic gravitons can be measured via the Li‐Baker high‐frequency gravity wave (HFGW) detector, and suggests the implications this has for the physics of early‐universe phase transitions. This paper indicates the role of Ng’s revised statistics in gravitational wave physics detection and the application of Baumann et al. (2007) formalism of reduction of rank‐two tensorial contributions to density wave physics, using the HFGW approximation directly at the beginning as well as Li’s treatment of energy density explicitly. This formalism is a way to refine and add more capacity to the Li‐Baker HFGW detector in reconstructing early‐universe conditions at the onset of the big bang.
Total-order and partial-order planning: a comparative analysis

For many years, the intuitions underlying partial-order planning were largely taken for granted. Only in the past few years has there been renewed interest in the fundamental principles underlying this paradigm. In this paper, we present a rigorous comparative analysis of partial-order and total-order planning by focusing on two specific planners that can be directly compared. We show that there are some subtle assumptions that underly the wide-spread intuitions regarding the supposed efficiency of partial-order planning. For instance, the superiority of partial-order planning can depend critically upon the search strategy and the structure of the search space. Understanding the underlying assumptions is crucial for constructing efficient planners.
Imitation learning with a value-based prior

The goal of imitation learning is for an apprentice to learn how to behave in a stochastic environment by observing a mentor demonstrating the correct behavior. Accurate prior knowledge about the correct behavior can reduce the need for demonstrations from the mentor. We present a novel approach to encoding prior knowledge about the correct behavior, where we assume that this prior knowledge takes the form of a Markov Decision Process (MDP) that is used by the apprentice as a rough and imperfect model of the mentor's behavior. Specifically, taking a Bayesian approach, we treat the value of a policy in this modeling MDP as the log prior probability of the policy. In other words, we assume a priori that the mentor's behavior is likely to be a high-value policy in the modeling MDP, though quite possibly different from the optimal policy. We describe an efficient algorithm that, given a modeling MDP and a set of demonstrations by a mentor, provably converges to a stationary point of the log posterior of the mentor's policy, where the posterior is computed with respect to the "value-based" prior. We also present empirical evidence that this prior does in fact speed learning of the mentor's policy, and is an improvement in our experiments over similar previous methods.
Working Out of Poverty: Job Creation and the Quality of Growth in Africa

In Africa, only few wage and salary jobs open up each year. Hence, most new entrants in the labor market end up supporting themselves in casual labor, self-employment, or small family businesses-activities with low productivity and highly vulnerable. With the globalizing economy, African economies need to become more competitive in all aspects of the investment climate, including improving worker's health and education, to better integrate the informal sector with the high wage economy. However, the analysis of labor markets in Africa is hampered by the lack of data which measures the economic activity earnings, and welfare of the household.
Pulsar Spin, Magnetic Fields, and Glitches

In the core of a canonical spinning magnetized neutron star(NS) a nearly uniform superfluid neutron vortex-array interacts strongly with a twisted array of magnetic flux-tubes threading the core's superconducting protons. One consequence is that changes in NS-spin alter both arrays and also the magnetic field distribution on the surface of the surrounding crust. Among predicted consequences for very young spinning-down NSs are "spin-down indices" increasing from 2 to 3, and a family of (Crab-like) spin-period "glitches" with permanent fractional jumps in spin-down torque 10E5 times greater than those in NS-spin. For older NSs, average spin-down indices increase to around 5, and an additional (Vela-like) family of giant glitches develops. NS spin-up to millesecond pulsars results in a high abundance of orthogonal and aligned rotators, and anomolously small polar cap areas. Observations do not conflict with these expectations. An epoch of NS magnetic field evolution between the onset of proton superconductivity (approx. yr) and neutron superfluidity (approx. 10E3 yrs ?) may be important for large surface magnetic field changes and needs further study. Observations generally considered evidence for NS precession seem to need reconsideration.
Living with Monsanto, 2015 Mich. St. L. Rev. 559 (2015)

Bowman v. Monsanto Co. signaled the end of an era of seed saving. Farmers must buy new seed for replanting or risk patent infringement. The familiar rhetoric of oppressed farmers belies the fact that Monsanto’s success rests in part on farmers prizing its innovations. Current trends indicate that this reliance on Monsanto will continue. The Supreme Court correctly found for Monsanto. However, future cases must iron out the kinks in the Bowman decision. Despite the Court’s best intentions, inadvertence cannot shield farmers from patent infringement. The Court must also make it clear that patentees cannot use licensing restrictions to claw back rights that patent exhaustion has extinguished. Beyond patent exhaustion, the Supreme Court in Federal Trade Commission v. Actavis recently held that the exercise patent rights, even if validly obtained and infringed, are subject to scrutiny under the rule of reason. The “scope of the patent” approach that shielded Monsanto from scrutiny under antitrust law and patent misuse in the past should be reexamined. The effects-focused approach under Actavis will help yield outcomes that better track policy goals. That approach should contain three features. First, it should be based on a coherent theory of harm. Second, that theory should be supported by evidence that the harm can be effected. Third, the approach should contain heuristics to make it administrable, such as harm to † Assistant Professor, The John Marshall Law School. I am grateful to Logan Breed, Peter Carstensen, Jorge Contreras, Shubha Ghosh, Herb Hovenkamp, Allen Kamp, Mark Patterson, Viola Pfirti, Jurgita Randakevi i t , Amelia Smith Rinehart, Josh Sarnoff, Spencer Waller, Beth Winston, Koren Wong-Ervin as well as the participants of the Michigan State Law Review Symposium on “Public Domain(s): Law, Generating Knowledge, and Furthering Innovation in the Information Economy,” the Edward D. Manzo Scholars in Patent Law Lecture, and the International Scholars Conference on Intellectual Property Law 2014 in Vienna, Austria for their helpful comments and suggestions. Many thanks also to Crystal Bultje, William Cox, Jessica Odell, Jennifer Muse, Marie Rauschenberger, and their team at the Michigan State Law Review for outstanding editorial assistance. Anisha Mehta provided valuable research assistance. All errors and omissions remain my own. 560 Michigan State Law Review 2015:559 competition and innovation and a shifting of the burden of production in appropriate cases informed by judicial experience and
An Information Theoretic Approach to Econometrics

Preface 1. Econometric information recovery Part I. Traditional Parametric and Semiparametric Probability Models: Estimation and Inference: 2. Formulation and analysis of parametric and semiparametric linear models 3. Method of moments, GMM, and estimating equations Part II. Formulation and Solution of Stochastic Inverse Problems: 4. A stochastic-empirical likelihood inverse problem: formulation and estimation 5. A stochastic-empirical likelihood inverse problem: inference 6. Kullback-Leibler information and the maximum empirical exponential likelihood Part III. A Family of Minimum Discrepancy Estimators: 7. The Cressie-Read family of divergence measures and likelihood functions 8. Cressie-Read-MEL-type estimators in practice: evidence of estimation and inference sampling performance Part IV. Binary Discrete Choice MPD-EML Econometric Models: 9. Family of distribution functions for the binary response-choice model 10. Estimation and inference for the binary response model based on the MPD family of distributions Part V. Optimal Convex Divergence: 11. Choosing the optimal divergence under quadratic loss 12. Epilogue.
Positivity of Chern classes of Schubert cells and varieties

We show that the Chern-Schwartz-MacPherson class of a Schubert cell in a Grassmannian is represented by a reduced and irreducible subvariety in each degree. This gives an affirmative answer to a positivity conjecture of Aluffi and Mihalcea.
Potential Site Effects and Transgene Expression Discrepancies in Mouse Lifespan Studies.

Our published report in this issue of Cell Metabolism (Oh et al., 2015) documents a role for the exocytosis protein Syntaxin 4 (Syn4) in extending longevity and health-span in mice. The study was initially conducted at Indiana University School of Medicine (IU), and given the significant longevity phenotype of the IU cohort (+33%), an independent Syn4 transgenic (Tg) mouse colony was established at the University of Michigan (UM), a site with ample experience in conducting mouse lifespan studies, to assess the reproducibility of the longevity phenotype.
Investigation of mechanical properties of cryogenically treated music wire

It has been reported that treating music wire (high carbon steel wire) by cooling to cryogenic temperatures can enhance its mechanical properties with particular reference to those properties important for musical performance. We use such wire for suspending many of the optics in Advanced LIGO, the upgrade to LIGO—the Laser Interferometric Gravitational-Wave Observatory. Two properties that particularly interest us are mechanical loss and breaking strength. A decrease in mechanical loss would directly reduce the thermal noise associated with the suspension, thus enhancing the noise performance of mirror suspensions within the detector. An increase in strength could allow thinner wire to be safely used, which would enhance the dilution factor of the suspension, again leading to lower suspension thermal noise. In this article, we describe the results of an investigation into some of the mechanical properties of music wire, comparing untreated wire with the same wire which has been cryogenically treated. For the samples we studied, we conclude that there is no significant difference in the properties of interest for application in gravitational wave detectors.
Malnutrition and poverty in Guatemala

The objective of this paper is to document the presence and distribution of child and adult malnutrition in Guatemala, to analyze the relationship between selected child, maternal, household and community characteristics and children's nutritional status and to outline the implications of the most important findings for nutritional policy. The prevalence of chronic malnutrition among Guatemalan children in 2000 was the highest in Latin America and among the highest in the world. The data show very strong socioeconomic and geographic patterns. The econometric analysis reveals a strong effect of income and of intergenerational effects through parents' height. Education of adults in the household and the availability of infrastructure are other important determinants of children's growth attainment. Finally, even controlling for income and other household and community characteristics, ethnicity is an important determinant of child nutritional status. The study also reveals an increasing prevalence of excess weights and obesity among children and adults. Over-nutrition tends to be higher among individuals living in urban areas and among non-poor and non-indigenous households.
The Asymmetric Synthesis of Tetrahydrolipstatin

The various syntheses of the over-the-counter anti-obesity drug tetrahydrolipstatin (also known as Orlistat) are reviewed. The 31 various syntheses cover the development of enantioselective natural products synthesis since the first synthesis of tetrahydrolipstatin (THL) by Schneider in 1987. After Schneider's landmark synthetic effort there have been numerous total and formal syntheses of THL, which have involved a diverse range of approaches. These various syntheses can be classified by the methods that were used to install the stereochemistry, for instance, chiral auxiliary, asymmetric aldol, asymmetric allylation/crotylation, asymmetric reductions, asymmetric resolutions, asymmetric oxidations, and chiron approach. These routes also feature the elegant use of a chiral phosphate template, a tandem [2+2]-Mukaiyama aldol-lactonization, an anti-aldol segment via a non-aldol route, a Prins cyclization, and an epoxide carbonylation.
Effect of distance to radiation treatment facility on use of radiation therapy after mastectomy in elderly women.

Purpose: We sought to study the effect of distance to the nearest radiation treatment facility on the use of postmastectomy radiation therapy (PMRT) in elderly women. Methods and Materials: Using data from the linked Surveillance, Epidemiology, and End Results–Medicare (SEER-Medicare) database, we analyzed 19,787 women with Stage I or II breast cancer who received mastectomy as definitive surgery during 1991 to 1999. Multivariable logistic regression was used to investigate the association of distance with receipt of PMRT after adjusting for clinical and sociodemographic factors. Results: Overall 2,075 patients (10.5%) treated with mastectomy received PMRT. In addition to cancer and patient characteristics, in our primary analysis, increasing distance to the nearest radiation treatment facility was independently associated with a decreased likelihood of receiving PMRT (OR = 0.996 per additional mile, p = 0.01). Secondary analyses revealed that the decline in PMRT use appeared at distances of more than 25 miles and was statistically significant for those patients living more than 75 miles from the nearest radiation facility (odds of receiving PMRT of 0.58 [95% CI=0.34–0.99] vs. living within 25 miles of such a facility). The effect of distance on PMRT appeared to be more pronounced with increasing patient age (>75 years). Variation in the effect of distance on radiation use between regions of the country and nodal status was also identified. Conclusions: Oncologists must be cognizant of the potential barrier to quality care that is posed by travel distance, especially for elderly patients; and policy makers should consider this fact in resource allocation decisions about radiation treatment centers.
Interaction of perfluorocarbons with carbon

Abstract Activated carbon is an effective stoichiometric fluorine acceptor which defluorinates perfluoroalkanes with the partial structure (Rf)2CFCF(Rf)2 to alkenes and perfluoroalkenes to dienes. Carbon catalyzes double-bond shifts, as well as cis/trans and ring-chain perfluoro-olefin isomerizations. Carbon effectively catalyzes TFE and HFP dimerizations. Less effectively, carbon catalyzes further oligomerization of TFE to give low yields of linear, internal olefins. Free radicals may be the key surface intermediates.
On the Size of Structures in the Solar Corona

Fine-scale structure in the corona appears not to be well resolved by current imaging instruments. Assuming this to be true offers a simple geometric explanation for several current puzzles in coronal physics, including the apparent uniform cross section of bright threadlike structures in the corona, the low EUV contrast (long apparent scale height) between the top and bottom of active region loops, and the inconsistency between loop densities derived by spectral and photometric means. Treating coronal loops as a mixture of diffuse background and very dense, unresolved filamentary structures addresses these problems with a combination of high plasma density within the structures, which greatly increases the emissivity of the structures, and geometric effects that attenuate the apparent brightness of the feature at low altitudes. It also suggests a possible explanation for both the surprisingly high contrast of EUV coronal loops against the coronal background, and the uniform "typical" height of the bright portion of the corona (about 0.3 R☉) in full-disk EUV images. Some ramifications of this picture are discussed, including an estimate (10-100 km) of the fundamental scale of strong heating events in the corona.
Homodesmotic reactions for thermochemistry

Achieving highly accurate thermochemical predictions from relatively low levels of electronic structure theory has long been a goal of computational chemistry. One route to such a goal is to exploit the systematic cancellation of errors. This approach was spearheaded by the Pople group in the 1970s with the introduction of isodesmic bond-separation reactions, and then extended by other groups to homodesmotic (HD) and hyperhomodesmotic reactions over the ensuing years. Unfortunately, the propagation of multiple, nonequivalent definitions of HD reactions, accompanied by a panoply of related reaction classes, has lead to a great deal of confusion. We review recent efforts to introduce a refined hierarchy of HD reactions for use in thermochemical predictions and to quantify the degree of error cancellation that can be achieved. Examples of the use of reactions from the HD hierarchy from the literature are presented, as are current limitations of this HD hierarchy for thermochemistry. Although the use of such error-balanced reactions are no longer mandatory for high-accuracy thermochemical predictions of small molecules, they still offer significant advantages in this context, and offer one route to accurate thermochemical predictions of larger molecules. © 2011 John Wiley & Sons, Ltd.