cssi/SciSciGPT-SciSciNet huggingface dataset:
Beyond status: Seeing the whole child

Competing values underlie U.S. immigration law and child welfare law. Immigration law often operates in ways that intentionally hinder family unity, which in the child welfare context enjoys tremendous constitutional protection. First, the operation of immigration law undermines family unity by failing to recognize the variety of family structures that exist, which has profound implications for millions of mixed status families, that is, families in which all family members do not hold the same immigration status. Second, immigration law hinders family unity because it does not recognize children’s interests as a valid factor in immigration decisions, thereby failing to take into account the best interests of the child, a concept that otherwise is universally recognized in child welfare law. Despite the U.S. immigration system’s exceptional disregard for family unity and the best interests of the child, immigration status can become an issue in many contexts outside of immigration proceedings, from state intervention through child protection agencies to state court decisions in parent custody disputes. Therefore, systems and policies that affect immigrant children and their families must recognize the competing values underlying immigration law and child welfare law or risk importing improperly the immigration systems’ values into other contexts in ways that discourage family unity and negatively impact children.
Finding Radio Pulsars in and beyond the Galactic Center

Radio wave scattering is enhanced dramatically for Galactic center sources in a region with radius 15. Using scattering from Sgr A* and other sources, we show that pulse broadening for pulsars in the Galactic center is at least 6.3ν-4 s (ν = radio frequency in GHz) and is most likely 50-200 times larger because the relevant scattering screen appears to be within the Galactic center region itself. Pulsars beyond—but viewed through—the Galactic center suffer even greater pulse broadening and are angularly broadened by up to ~2'. Periodicity searches at radio frequencies are likely to find only long-period pulsars, and then only if optimized by using frequencies 7 GHz and by testing for small numbers of harmonics in the power spectrum. The optimal frequency is ν ~ 7.3 GHz[Δ0.1 P(α1/2)]-1/4, where Δ0.1 is the distance of the scattering region from Sgr A* in units of 0.1 kpc, P is the period (in seconds), and α is the spectral index. A search for compact sources using aperture synthesis may be far more successful than searches for periodicities because the angular broadening is not so large as to desensitize the survey. We estimate that the number of detectable pulsars in the Galactic center may range from ≤1 to 100, with the larger values resulting from recent, vigorous starbursts. Such pulsars provide unique opportunities for probing the ionized gas, gravitational potential, and stellar population near Sgr A*.
Transition Economies: How Appropriate is the Size and Scope of Government?

This paper assesses changes in the size and scope of government in 24 transition economies. While these governments have reduced public expenditures in relation to GDP, and public employment as a share of population, some indicators suggest that the size remains high (eg, rising indebtedness, a heavy regulatory burden, arrears, and the prevalence of noncash transactions). At the same time, the scope of government activities – although evolving – has not necessarily become appropriate. This paper provides some recommendations for aligning the scope of government with the increasing market orientation of these economies.
Omnidirectional transmitter combining antenna

Historically, it has been difficult to combine transmitters which are closely spaced in frequency onto the same omnidirectional antenna. Two principal techniques have been used: cavity combining and transmission line hybrid combining. When using cavities, the minimum separation is limited by the amount of insertion loss that is acceptable and by the frequency stability of the cavities. In the 800- MHz land mobile frequency band, cavity combining has been used to combine transmitters as closely spaced as 0.5 MHz with 3 dB of insertion loss. When combining transmitters separated less than 0.5 MHz, hybrid combining has been used. When two transmitters are combined using this technique, half of the power of each is dissipated into a matched load. Further, each time the number of transmitters being combined is doubled, an additional 3 dB is added to the insertion loss. A new technique has been developed which utilizes transmission line hybrids to combine the transmitters, but which does not suffer from large insertion loss. The power that was previously dissipated in the resistive load is radiated in a manner that produces an omnidirectional pattern. The antenna and network that accomplish this combine signals with 90° phase shifts. Measurements show that it is possible to combine eight transmitters arbitrarily close in frequency with 35 dB of isolation between adjacent channels, less than 0.5 dB insertion loss, and with horizontal pattern circularity better than ±3 dB. Additionally, this technique can be combined with cavity combining to maintain high isolation between additional tranmitters.
Controlling Lewis Basicity in Polythioarsenate Fluxes: Stabilization of KSnAsS5 and K2SnAs2S6. Extended Chains and Slabs Based on Pyramidal β-[AsS4]3- and [AsS3]3- Units

Two low-dimensional compounds, KSnAsS5 and K2SnAs2S6, were prepared using liquid polythioarsenate salts, and the results differ from those obtained with the well studied thiophosphate flux. KSnAsS5 crystallizes in the orthorhombic space group Pbam with cell parameters of a = 8.136(2) A, b = 13.784(4) A, c = 7.428(2) A. KSnAsS5 features the unusual pyramidal species [AsS2(S2)]3-. K2SnAs2S6 crystallizes in the trigonal space group P3 with cell parameters a = 6.717(5) A, b = 7.204(8) A, γ = 120°. The compounds were obtained by controlling the Lewis basicity of the K2S/As2S3/S flux. The optical, thermal, and spectroscopic properties of the compounds are reported.
Numerical simulation of high Reynolds number transonic flows

A code has been developed for simulating high Reynolds number transonic flow fields of arbitrary configuration. An explicit finite-difference method with time splitting is used to solve the time-dependent equations for compressible turbulent flow. A nonorthogonal computational mesh of arbitrary configuration facilitates the description of the flow field. The code is applied to simulate the flow over an 18 percent thick circular-arc biconvex airfoil at zero angle of attack and free-stream Mach number of 0.775. A simple mixing-length model is used to describe the turbulence and chord Reynolds numbers of 1, 2, 4, and 10 million are considered. The solution describes in sufficient detail both the shock-induced and trailing-edge separation regions, and provides the profile and friction drag.
Engineering globalization: oxymoron or opportunity?

Globalization can have a purely descriptive meaning, one that simply recognizes the facts of the increasing interdependence of national economies, the diffusion of technology and technological activity across international borders, and the intersection and integration of cultures. Taken in a normative sense, globalization, in addition to being a description of reality, can also turn out to be a prescription for a preferred reality. Engineering programs should take a much broader view of their responsibilities than the narrow instrumental objective of providing employees for the industries of advanced technological societies.
SYNTHESIS OF OPTICALLY PURE DIAZA-12-CROWN-4 WITH A PENDANT GROUP

The optically pure diaza-12-crown-4 that has a 2-hydroxymethyl sidearm is synthesized in fully protected form, starting from (R)-1-O-benzylglycerol.
A possible adverse effect of needing to issue new equity in the future

Abstract This research develops a model of how a need to issue new equity in the future can have an adverse affect on a stock's current price, value, and beta. In particular, if the market error in pricing a stock is positively correlated with the return on the market portfolio of all assets, losses from having to issue equity in the future at a distressed price will result in the stock having a higher beta and a lower current market value. To avoid this situation, corporations are motivated to hold greater financial slack.
Biocatalytic resolution of (±)-hydroxyalkanoic esters. A strategy for enhancing the enantiomeric specificity of lipase-catalyzed ester hydrolysis

Abstract A general biocatalytic resolution procedure for the preparation of a variety of R - and S -hydroxyalkanoic esters of high optical purity has been developed. The noteworthy feature of this methodology resides in the selection of a non-hydrolyzable ester at the carboxyl terminus to improve the enantiospecificity in the lipase-catalyzed hydrolysis of the acyloxy ester.
Electrolysis for the reduction of spurs of the nasal septum

A year ago I gave the results of recent experience with electrolysis for the reduction of spurs of the nasal septum, in a paper read before the section of Laryngology and Otology of theAmerican Medical Association, 1 and later in another paper before the American Laryngological Association, 2 and it is not my purpose in this supplementary report to repeat the technical details of the procedure or to recite cases at length, but simply to formulate conclusions bearing upon the exact limitations of this method. The bibliography having been presented in previous papers, will be omitted at this time; suffice it to say, that a few European operators have advocated the method and some have praised it with seeming extravagance. Customarily spurs or excrescences of the septum narium are removed by surgical means, by the knife, saw and drill, and these are the methods employed by myself in the
Evaluation of ultrasonography as a diagnostic technique in the assessment of rotator cuff tendon tears.

In this study we assessed the clinical usefulness of ultrasonography as a modality in the diagnosis of rota tor cuff tears. One hundred twenty patients with pre operative ultrasonography were analyzed by diagnostic arthroscopy to evaluate rotator cuff integrity. Two groups, 61 patients with a positive ultrasonogram and 59 patients with a negative ultrasonogram, were ana lyzed. The 61 patients with a positive ultrasonogram preoperatively were found to have 42 full-thickness tears and 19 partial-thickness tears. Diagnostic arthros copy confirmed a sensitivity of 95% for the full-thick ness tears and 41 % for the partial-thickness tears. In the 59 patients with negative ultrasonography, the specificity for full-thickness tears was 93% and in the 19 partial-thickness tears it was 91 %. Our conclusion is that ultrasonography is an effective modality for the assessment of full-thickness tears, but not partial-thick ness tears.
Aromatic hydrocarbons, diamonds, and fullerenes in interstellar space: puzzles to be solved by laboratory and theoretical astrochemistry

Abstract New research is presented, and previous research is reviewed, on the emission and absorption of interstellar aromatic hydrocarbons. Emission from aromatic hydrocarbons dominates the mid-infrared emission of many galaxies, including our own Milky Way galaxy. Only recently have aromatic hydrocarbons been observed in absorption in the interstellar medium, along lines of sight with high column densities of interstellar gas and dust. Much work on interstellar aromatics has been carried out, with astronomical observations and laboratory and theoretical astrochemistry. In many cases, the predictions of laboratory and theoretical work are confirmed by astronomical observations but, in other cases, clear discrepancies exist that provide problems to be solved by a combination of astronomical observations, laboratory studies, and theoretical studies. The emphasis of this paper will be on current outstanding puzzles concerning aromatic hydrocarbons that require further laboratory and theoretical astrochemistry to resolve. This paper will also touch on related topics where laboratory and theoretical astrochemistry studies are needed to explain astrophysical observations, such as a possible absorption feature due to interstellar ‘diamonds’ and the search for fullerenes in space.
The Donaldson–Witten Function for Gauge Groups of Rank Larger Than One

We study correlation functions in topologically twisted , d=4 supersymmetric Yang–Mills theory for gauge groups of rank larger than one on compact four-manifolds X. We find that the topological invariance of the generator of correlation functions of BRST invariant observables is not spoiled by noncompactness of field space. We show how to express the correlators on simply connected manifolds of b 2,+(X)>0 in terms of Seiberg–Witten invariants and the classical cohomology ring of X. For manifolds X of simple type and gauge group SU(N) we give explicit expressions of the correlators as a sum over =1 vacua. We describe two applications of our expressions, one to superconformal field theory and one to large N expansions of SU(N) , d=4 supersymmetric Yang–Mills theory.
Finite subtype inference with explicit polymorphism

Finite subtype inference occupies a middle ground between Hindley-Milner type inference (as in ML) and subtype inference with recursively constrained types. It refers to subtype inference where only finite types are allowed as solutions. This approach avoids some open problems with general subtype inference, and has practical motivation where recursively constrained types are not appropriate. This paper presents algorithms for finite subtype inference, including checking for entailment of inferred types against explicitly declared polymorphic types. This resolves for finite types a problem that is still open for recursively constrained types. Some motivation for this work, particularly for finite types and explicit polymorphism, is in providing subtype inference for first-class container objects with polymorphic methods.
SDAP: A Secure Hop-by-Hop Data Aggregation Protocol for Sensor Networks

Hop-by-hop data aggregation is a very important technique for reducing the communication overhead and energy expenditure of sensor nodes during the process of data collection in a sensor network. However, because individual sensor readings are lost in the per-hop aggregation process, compromised nodes in the network may forge false values as the aggregation results of other nodes, tricking the base station into accepting spurious aggregation results. Here a fundamental challenge is how can the base station obtain a good approximation of the fusion result when a fraction of sensor nodes are compromised?To answer this challenge, we propose SDAP, a Secure Hop-by-hop Data Aggregation Protocol for sensor networks. SDAP is a general-purpose secure data aggregation protocol applicable to multiple aggregation functions. The design of SDAP is based on the principles of divide-and-conquer and commit-and-attest. First, SDAP uses a novel probabilistic grouping technique to dynamically partition the nodes in a tree topology into multiple logical groups (subtrees) of similar sizes. A commitment-based hop-by-hop aggregation is performed in each group to generate a group aggregate. The base station then identifies the suspicious groups based on the set of group aggregates. Finally, each group under suspect participates in an attestation process to prove the correctness of its group aggregate. The aggregate by the base station is calculated over all the group aggregates that are either normal or have passed the attestation procedure. Extensive analysis and simulations show that SDAP can achieve the level of efficiency close to an ordinary hop-by-hop aggregation protocol while providing high assurance on the trustworthiness of the aggregation result. Last, prototype implementation on top of TinyOS shows that our scheme is practical on current generation sensor nodes such as Mica2 motes.
Testing non-commutative QED, constructing non-commutative MHD

Abstract The effect of non-commutativity on electromagnetic waves violates Lorentz invariance: in the presence of a background magnetic induction field b , the velocity for propagation transverse to b differs from c, while propagation along b is unchanged. In principle, this allows a test by the Michelson–Morley interference method. We also study non-commutativity in another context, by constructing the theory describing a charged fluid in a strong magnetic field, which forces the fluid particles into their lowest Landau level, and renders the fluid dynamics non-commutative, with a Moyal product determined by the background magnetic field.
Versatile Synthesis of Pentalene Derivatives via the Pd-Catalyzed Homocoupling of Haloenynes

A palladium-catalyzed, reductive homocoupling of haloenynes yields a diverse range of polysubstituted pentalene derivatives, including annulated dibenzopentalenes and dithienylpentalenes.
Electroweak unification into a five-dimensional SU(3) at a TeV

Abstract We apply a recently proposed mechanism for predicting the weak mixing angle to theories with TeV-size dimensions. “Reconstruction” of the associated moose (or quiver) leads to theories which unify the electroweak forces into a five-dimensional SU (3) symmetry. Quarks live at an orbifold fixed point where SU (3) breaks to the electroweak group. A variety of theories—all sharing the same successful prediction of sin 2 θ W —emerges; they differ primarily by the spatial location of the leptons and the absence or presence of supersymmetry. A particularly interesting theory puts leptons in a Konopinski–Mahmoud triplet and suppresses proton decay by placing quarks and leptons on opposite fixed points.
Single Parenthood and Childhood Outcomes in the Mid-Nineteenth-Century Urban South

Data from the urban South reveal two notable consequences of single parenthood during the mid-nineteenth century. First, white children residing with single mothers left school earlier than children residing with two parents, and black children in single mother homes started school later and left school earlier. Second, white youths in single-mother homes faced an increased incidence of labor-force participation, but black youths in the same situation did not. Single parenthood imposed costs, in terms of foregone human-capital formation, on children in the mid-nineteenth century, but the consequences of single motherhood were mitigated by social norms regarding childhood education.
Understanding Stakeholder Responses to Corporate Citizenship Initiatives: Managerial Guidelines and Research Directions

Abstract Firms are increasingly devoting attention to corporate citizenship initiatives. Despite the great interest in these initiatives, there is little academic research on their potential effects to guide managerial decisions. This article draws on theories from the consumer behavior literature to identify how socially oriented programs can foster both consumer and employee engagement, while also improving the welfare of society at-large and the financial fortunes of companies. In doing so, the authors advance a research agenda and offer prescriptive managerial advice.
ASSESSING THE ASSOCIATION BETWEEN TRENDS IN A BIOMARKER AND RISK OF EVENT WITH AN APPLICATION IN PEDIATRIC HIV/AIDS

We present a new joint longitudinal and survival model aimed at estimating the association between the risk of an event and the change in and history of a biomarker that is repeatedly measured over time. We use cubic B-splines models for the longitudinal component that lend themselves to straight-forward formulations of the slope and integral of the trajectory of the biomarker. The model is applied to data collected in a long term follow-up study of HIV infected infants in Uganda. Estimation is carried out using MCMC methods. We also explore using the deviance information criteria, the conditional predictive ordinate and ROC curves for model selection and evaluation.
Parabolic constructions of asymptotically flat 3-metrics of prescribed scalar curvature

In 1993, Bartnik (J. Differ. Geom. 37(1):37–71) introduced a quasi-spherical construction of metrics of prescribed scalar curvature on 3-manifolds. Under quasi-spherical ansatz, the problem is converted into the initial value problem for a semi-linear parabolic equation of the lapse function. The original ansatz of Bartnik started with a background foliation with round metrics on the 2-sphere leaves. This has been generalized by several authors (Shi and Tam in J. Differ. Geom. 62(1):79–125, 2002; Smith in Gen. Relat. Gravit. 41(5):1013–1024, 2009; Smith and Weinstein in Commun. Anal. Geom. 12(3):511–551, 2004) under various assumptions on the background foliation. In this article, we consider background foliations given by conformal round metrics, and by the Ricci flow on 2-spheres. We discuss conditions on the scalar curvature function and on the foliation that guarantee the solvability of the parabolic equation, and thus the existence of asymptotically flat 3-metrics with a prescribed inner boundary. In particular, many examples of asymptotically flat-scalar flat 3-metrics with outermost minimal surfaces are obtained.
On-line scheme for computing rotation factors

Abstract An integrated radix-2 on-line algorithm for computing rotation factors for matrix transformations is presented. The inputs are in sign-and-magnitude, floating-point representation and the outputs can be used in on-line signed-digit or in parallel form. The exponents are computed using conventional arithmetic while the significands are processed using on-line algorithms. The conventional result is obtained by using an on-the-fly conversion scheme. The rotation factors are computed in 10 + n clock cycles for n -bit significands. The clock period is kept small by the use of redundant adder schemes and low-precision estimates. The implementation and performance of the algorithm are discussed and compared with other approaches.
Shear flow of highly concentrated emulsions of deformable drops by numerical simulations

An efficient algorithm for hydrodynamical interaction of many deformable drops subject to shear flow at small Reynolds numbers with triply periodic boundaries is developed. The algorithm, at each time step, is a hybrid of boundary-integral and economical multipole techniques, and scales practically linearly with the number of drops N in the range N < 1000, for NΔ ∼ 103 boundary elements per drop. A new near-singularity subtraction in the double layer overcomes the divergence of velocity iterations at high drop volume fractions c and substantial viscosity ratio γ. Extensive long-time simulations for N = 100–200 and NΔ = 1000–2000 are performed up to c = 0.55 and drop-to-medium viscosity ratios up to λ = 5, to calculate the non-dimensional emulsion viscosity μ* = Σ12/(μeγ˙), and the first N1 = (Σ11−Σ22)/(μe[mid ]γ˙[mid ]) and second N2 = (Σ22−Σ33)/(μe[mid ]γ˙[mid ]) normal stress differences, where γ˙ is the shear rate, μe is the matrix viscosity, and Σij is the average stress tensor. For c = 0.45 and 0.5, μ* is a strong function of the capillary number Ca = μe[mid ]γ˙[mid ]a/σ (where a is the non-deformed drop radius, and σ is the interfacial tension) for Ca [Lt ] 1, so that most of the shear thinning occurs for nearly non-deformed drops. For c = 0.55 and λ = 1, however, the results suggest phase transition to a partially ordered state at Ca [les ] 0.05, and μ* becomes a weaker function of c and Ca; using λ = 3 delays phase transition to smaller Ca. A positive first normal stress difference, N1, is a strong function of Ca; the second normal stress difference, N2, is always negative and is a relatively weak function of Ca. It is found at c = 0.5 that small systems (N ∼ 10) fail to predict the correct behaviour of the viscosity and can give particularly large errors for N1, while larger systems N [ges ] O(102)show very good convergence. For N ∼ 102 and NΔ ∼ 103, the present algorithm is two orders of magnitude faster than a standard boundary-integral code, which has made the calculations feasible.
Affine PBW bases and MV polytopes in rank 2

Mirkovic–Vilonen (MV) polytopes have proven to be a useful tool in understanding and unifying many constructions of crystals for finite-type Kac-Moody algebras. These polytopes arise naturally in many places, including the affine Grassmannian, pre-projective algebras, PBW bases, and KLR algebras. There has recently been progress in extending this theory to the affine Kac-Moody algebras. A definition of MV polytopes in symmetric affine cases has been proposed using pre-projective algebras. In the rank-2 affine cases, a combinatorial definition has also been proposed. Additionally, the theory of PBW bases has been extended to affine cases, and, at least in rank-2, we show that this can also be used to define MV polytopes. The main result of this paper is that these three notions of MV polytope all agree in the relevant rank-2 cases. Our main tool is a new characterization of rank-2 affine MV polytopes.
Application of advanced probabilistic fracture mechanics to life evaluation of turbine rotor blade attachments

This paper describes the application of an advanced probabilistic fracture mechanics computational algorithm with inspection simulation to the probabilistic life assessment of a turbine blade attachment, sometimes referred to as a steeple or fir tree. The life of the steeple is limited by high cycle fatigue. The methodology utilized combines structural finite element analysis, stochastic fatigue crack growth, and crack inspection and repair. The resulting information provides the engineer with an assessment of the probability of failure of the structure as a function of operating time and the effect of the inspection procedure. This information can form the basis of inspection planning and retirement-for-cause decisions.
FINITE GEOMETRIES WITH QUBIT OPERATORS

Finite projective geometries, especially the Fano plane, have been observed to arise in the context of certain quantum gate operators. We use Clifford algebras to explain why these geometries, both planar and higher dimensional, appear in the context of multi-qubit composite systems.
Continuous testing in eclipse

Continuous testing uses excess cycles on a developer's workstation to continuously run regression tests in the background, providing rapid feedback about test failures as code is edited. It reduces the time and energy required to keep code well-tested, and it prevents regression errors from persisting uncaught for long periods of time.
Efficient Preparation of γ-Hydroxynitriles via Nitrile Enolate-Epoxide Reactions: Scope and Diastereoselectivity

Abstract The nucleophilic opening of epoxides by nitrile enolates using an efficient, convenient protocol is described. The diastereoselectivity of this reaction was explored and found to give syn:anti ratios ranging from 1.1:1.0 to 4.8:1.0. ‡ Camille and Henry Dreyfus Scholar/Fellow 1995–1997.
Standardization of beam line representations

Abstract Standardization of beam line representations means that a single set of data can be used in many situations to represent a beam line. This set of data should be the same no matter what the program to be run or the calculation to be made. We have concerned ourselves with three types of standardization: (1) The same set of data should be usable by different programs. (2) The inclusion of other items in the data, such as calculations to be done, units to be used, or preliminary specifications, should be in a notation similar to the lattice specification. (3) A single set of data should be used to represent a given beam line, no matter what is being modified or calculated. The specifics of what is to be modified or calculated can be edited into the data as part of the calculation. These three requirements all have aspects not previously discussed in a public forum. Implementations into TRANSPORT [1] will be discussed.
Effects of temporal and spatial separation on velocity and strength of illusory line motion.

The effects of line length and of spatial or temporal distance on illusory line motion (i.e., on the perception that a stationary line unfolds or expands away from a previously presented stationary cue) were examined in five experiments. Ratings of relative velocity decreased with increases in stimulus onset asynchrony between appearance of the cue and appearance of the line (from 50 to 450 ms), whereas the extremity of ratings of direction (i.e., strength of the ratings of illusory line motion) increased with increases in stimulus onset asynchrony (from 50 to either 250 or 450 ms). Ratings of relative velocity increased with increases in line length, whereas ratings of direction were not influenced by increases in line length. Ratings of relative velocity and direction were not influenced by increases in the distance of the near or the far end of the line from the cue. Implications of these data for attentional theories and apparent-motion theories of illusory line motion are discussed.
Social Revolution, the State, and War: How Revolutions Affect War-Making Capacity and Interstate War Outcomes

Democracy has been the primary focus of our efforts to understand the impact of domestic institutions on processes of international conflict. In this article, we examine how a particular nondemocratic regime type, postrevolutionary states, affects military capabilities and war outcomes. Drawing on scholarship that conceptualizes revolutions as a unique class of modernizing events that result in stronger state structures, we argue that postrevolutionary states should be better able to mobilize populations and economic resources for military purposes. Tests performed on a comprehensive sample of twentieth-century states and interstate wars confirm our predictions: postrevolutionary states have larger, better funded militaries and achieve more successful war outcomes.
Seeking Passe-Partout in the Catalytic Asymmetric Aziridination of Imines: Evolving Toward Substrate Generality for a Single Chemzyme

The asymmetric catalytic aziridination reaction (AZ reaction) of imines derived from dianisylmethyl (DAM) amine and tetra-methyldianisylmethyl (MEDAM) amine were examined with boroxinate catalysts prepared from both the VANOL and VAPOL ligands. This included an evaluation of different protocols for the preparation of the catalyst. The AZ reaction of DAM and MEDAM imines prepared from nine different aryl and aliphatic aldehydes were examined. The MEDAM imines were superior to the DAM imines in the AZ reaction, giving much higher asymmetric inductions and higher overall yields of aziridines. The MEDAM imines were found to also be superior to the previously studied diphenylmethyl (benzhydryl or Bh) and tetra-tert-butyldianisylmethyl (BUDAM) imines especially for imines derived from aliphatic aldehydes. The average asymmetric induction over the nine different MEDAM imines studied was 97% ee with the VAPOL catalyst and 96% ee with the VANOL catalyst. The MEDAM imines can be deprotected to give N-H aziridines i...
A SINful approach to Gaussian graphical model selection

Multivariate Gaussian graphical models are defined in terms of Markov properties, i.e., conditional independences, corresponding to missing edges in the graph. Thus model selection can be accomplished by testing these independences, which are equivalent to zero values of corresponding partial correlation coefficients. For concentration graphs, acyclic directed graphs, and chain graphs (both LWF and AMP classes), we apply Fisher's z-transform, Sidak's correlation inequality, and Holm's step-down procedure to simultaneously test the multiple hypotheses specified by these zero values. This simple method for model selection controls the overall error rate for incorrect edge inclusion. Prior information about the presence and/or absence of particular edges can be readily incorporated.
Alternative Total Synthesis of (−)-Galanthamine Hydrobromide

Abstract An alternative total synthesis of (−)-galanthamine (1) hydrobromide, employing ecofriendly amidation, oxidative coupling, and classical resolution strategies is accomplished.
A fast algorithm for context-aware buffer insertion

We study the problem of performing buffer insertion in the context of a given layout. In a practical situation, there are restrictions on where buffers may be inserted; for instance, it may be possible to route wires over a preplaced macro cell, but may not be possible to insert buffers in that region. As a result, it is desirable to perform route planning and buffer insertion simultaneously. Furthermore it is necessary that such an algorithm be aware of the trade-off between cost (e.g., total capacitance) and delay. In this context we propose the delay reduction to cost ratio (DRCR) problem and present a fast algorithm for the same. Solutions identified by the algorithm are characterized with respect to the overall cost versus performance trade-off curve. Computational experiments demonstrate the viability of the approach.
Heegaard Floer correction terms and rational genus bounds

Given an element in the first homology of a rational homology 3-sphere Y , one can consider the minimal rational genus of all knots in this homology class. This defines a function Θ on _(H1)(Y;Z), which was introduced by Turaev as an analogue of Thurston norm. We will give a lower bound for this function using the correction terms in Heegaard Floer homology. As a corollary, we show that Floer simple knots in L-spaces are genus minimizers in their homology classes, hence answer questions of Turaev and Rasmussen about genus minimizers in lens spaces.
Breakup of New Orleans Households After Hurricane Katrina

More than three decades ago, Bolin (1976, p. 267) lamented that “The greater part of disaster research has focused on complex organizations, the community, or individuals with the family as a unit being given only cursory attention.” Tierney’s (2007) recent survey of the field of disaster research indicates that this is still largely true, even as more attention to family processes has occurred through an increased emphasis on gender (e.g., Morrow, 1999). The literature on the sociology of disasters provides the insight that social impacts of natural disasters differ according to pre-disaster socioeconomic conditions, which describe the population’s degree of social vulnerability (e.g., Cutter, Boruff, & Shirley, 2003). In the present study, I consider household structure as a social vulnerability characteristic. I estimate the effect of Hurricane Katrina in 2005 on the break-up of New Orleans households following Katrina, considering both the incidence of break-up by household structure and the distribution of those household structures in pre-Katrina New Orleans. The data and methodological challenges of estimating an elevated incidence of household break-up attributable to the hurricane are considerable. In addressing them, I apply a case-control analytical framework to cases from a survey sample designed to be representative of New Orleans households in August 2005 (the Displaced New Orleans Residents Pilot Study, DNORPS; Sastry, 2009b) and to controls from an ongoing national panel survey of households (the Survey of Income and Program and Participation, SIPP; U.S. Census Bureau, 2010) over an equivalent period. In addressing the role of the pre-Katrina household structures, I also use the 2005 American Community Survey data (U.S. Census Bureau 2007b to compare New Orleans and the United States generally and to evaluate the representativeness of the analytical DNORPS and SIPP samples of New Orleans and U.S. household structures.
Current-driven dust-acoustic instability in a collisional plasma

Abstract The excitation of the dust-acoustic instability in a collisional dusty plasma is investigated. For conditions similar to those of recent laboratory experiments with neutral gas pressures of ∼ 100mTorr, it is found that zero-order electric fields E0 ≳ 10 Vm−1 are sufficient for the growth of perturbations with centimeter wavelengths. Much larger wavelengths generally require larger values of E0. Free electrons in the dusty plasma have a stabilizing effect, which can be very pronounced at the longest wavelengths.
Determinants of the method of sale in privatization

Abstract This paper explores the method of sale in the privatization process and difficulties implementing the most efficient option. In countries where state involvement has been more pervasive, the method of privatization chosen is less often the best available option, improvements in efficiency have been slower, and privatization has brought with it greater political instability. This brings the question of why this has been the case, and what could have been done to smooth the transition. This paper finds that efficient mechanisms become more likely when the government's budget is more strained and when the existing capital markets are deeper.
Implementing Residual Income Valuation With Linear Information Dynamics

Residual income (RI) valuation is a method of estimating firm value based on expected future accounting numbers. This study documents the necessity of using linear information models (LIMs) of the time series of accounting numbers in valuation. I find that recent studies that make ad hoc modifications to the LIMs contain internal inconsistencies and violate the no arbitrage assumption. I outline a method for modifying the LIMs while preserving internal consistency. I also find that when estimated as a time series, the LIMs of Ohlson (1995), and Feltham and Ohlson (1995) provide value estimates no better than book value alone. By comparing the implied price coefficients to coefficients from a price level regression, I find that the models imply inefficient weightings on the accounting numbers. Furthermore, the median conservatism parameter of Feltham and Ohlson (1995) is significantly negative, contrary to the model's prediction, for even the most conservative firms. To explain these failures, I estimate a...
Structures of coincidence symmetry groups

The structure of the coincidence symmetry group of an arbitrary n-dimensional lattice in the n-dimensional Euclidean space is considered by describing a set of generators. Particular attention is given to the coincidence isometry subgroup (the subgroup formed by those coincidence symmetries that are elements of the orthogonal group). Conditions under which the coincidence isometry group can be generated by reflections defined by vectors of the lattice are discussed and an algorithm to decompose an arbitrary element of the coincidence isometry group in terms of reflections defined by vectors of the lattice is given.
Syntheses and identification of the most abundant urinary type VI isoprostanes

The total synthesis of 8–12-iso-iPF2α -VI12 and its 5 epimer 13 is described. With the aid of the synthetic materials these isoprostanes have been identified in and isolated from human urine.
Stable Takens' Embeddings for Linear Dynamical Systems

Takens' embedding theorem remarkably established that concatenating M previous outputs of a dynamical system into a vector (called a delay coordinate map) can be a one-to-one mapping of a low-dimensional attractor from the system state space. However, Takens' theorem is fragile in the sense that even small imperfections can induce arbitrarily large errors in this attractor representation. We extend Takens' result to establish deterministic, explicit and nonasymptotic sufficient conditions for a delay coordinate map to form a stable embedding in the restricted case of linear dynamical systems and observation functions. Our work is inspired by the field of Compressive Sensing (CS), where results guarantee that low-dimensional signal families can be robustly reconstructed if they are stably embedded by a measurement operator. However, in contrast to typical CS results, i) our sufficient conditions are independent of the size of the ambient state space, and ii) some system and measurement pairs have fundamental limits on the conditioning of the embedding (i.e., how close it is to an isometry), meaning that further measurements beyond some point add no further significant value. We use several simple simulations to explore the conditions of the main results, including the tightness of the bounds and the convergence speed of the stable embedding. We also present an example task of estimating the attractor dimension from time-series data to highlight the value of stable embeddings over traditional Takens' embeddings.
Application of a Tip-Fin Controller to the Shuttle Orbiter for Improved Yaw Control

Aerodynamic and flight control analyses have shown that the application of the tip-fin controller and removal of the centerline vertical tail does not produce improved flyability of the Shuttle Orbiter in the supersonic speed regime. Preliminary design studies show that removal of the centerline vertical tail and the installation of tip-fin controllers could result in savings up to 900 kg. It is also shown that the reaction control system could be deactivated much sooner than it is possible with the present nominal orbiter configuration.
Flow-Invariant Hypersurfaces in Semi-Dispersing Billiards

This work results from our attempts to solve Boltzmann-Sinai’s hypothesis about the ergodicity of hard ball gases. A crucial element in the studies of the dynamics of hard balls is the analysis of special hypersurfaces in the phase space consisting of degenerate trajectories (which lack complete hyperbolicity). We prove that if a flow-invariant hypersurface J in the phase space of a semi-dispersing billiard has a negative Lyapunov function, then the volume of the forward image of J grows at least linearly in time. Our proof is independent of the solution of the Boltzmann-Sinai hypothesis, and we provide a complete and self-contained argument here.
Scattering of scalar waves by many small particles

Formulas are derived for solutions of many-body wave scattering problems by small particles in the case of acoustically soft, hard, and impedance particles embedded in an inhomogeneous medium. The limiting case is considered, when the size a of small particles tends to zero while their number tends to infinity at a suitable rate. Equations for the limiting effective (self-consistent) field in the medium are derived.
Hazardous Waste Hits Hollywood: Superfund and Housing Prices in Los Angeles

This paper contributes to the ongoing debate concerning the effect of various actions taken by the U.S. Environmental Protection Agency under CERCLA, commonly known as the Superfund Program, on housing prices. This study uses a housing transaction panel dataset encompassing the five major counties of the Los Angeles Combined Statistical Area to estimate the program’s influence on the local housing market. Using house and time-varying census tract fixed effects, I am able to avoid many of the endogeneity problems seen in previous research attempting to measure the Superfund treatment effect. An estimate of the effect on housing prices is given for each of the major events that occur under a typical Superfund remediation. After controlling for confounding correlated unobservables, I find a 7.3 % increase in sales price for houses within 3 km of a site that moves through the complete Superfund program. The analysis gives evidence of positive price appreciation for housing markets and serves as a lower bound for measuring remediation benefits.
Lattice dynamics of graphite intercalation compounds

Abstract We apply a k z -axis zone folding model that accounts for the staging symmetry to calculate the phonon dispersion curves for graphite intercalation compounds of arbitrary stage. The results are applied to calculate the phonon density of states, velocity of sound, and elastic constants for intercalated graphite.
Alternative estimators for factor garch models—A monte carlo comparison

This paper proposes four estimators for factor GARCH models: two-stage univariate GARCH (2SUE), two-stage quasi-maximum likelihood (2SML), quasi-maximum likelihood with known factor weights (RMLE), quasi-maximum likelihood with unknown factor weights (MLE). A Monte-Carlo study is designed for bivariate one-factor GARCH models to examine the finite sample properties. Results are presented for biases, ratios of standard errors to standard deviations, ratios of variances, coverage of confidence intervals, effects of misspecified factor weights, and finite sample properties of the 2SUE for factor GARCH-in-mean models.
Finite well solution for the E(5) Hamiltonian

The recently proposed infinite square well E(5) description of nuclei at the critical point of the phase transition from vibrator to $\ensuremath{\gamma}$-soft rotor is extended to include the effects of finite well depth. The evolution of nuclear observables as a function of well depth is studied, and observables sensitive to finite well depth are identified.
Job Hopping, Earnings Dynamics, and Industrial Agglomeration in the Software Publishing Industry

Abstract This paper investigates the implications of industrial clustering for labor mobility and earnings dynamics in one large and increasingly important high-technology sector. Taking advantage of longitudinal employee-employer matched data, I exploit establishment-level variation in agglomeration to explore how clustering in the software publishing industry affects labor market outcomes. The results show that clustering makes it easier for workers to job hop within the sector. Higher earnings levels in more agglomerated areas are partly attributable to sorting across locations among workers and firms in the industry on the basis of observable and unobservable characteristics. Controlling for this heterogeneity, workers in clusters have relatively steep earnings-tenure profiles, accepting lower wages early in their careers in exchange for stronger earnings growth and higher wages later. These findings are consistent with theoretical models in which agglomeration improves labor market coordination and facilitates greater learning and human capital formation.
Intersections of loops and the Andersen–Mattes–Reshetikhin algebra

Given two free homotopy classes $\alpha_1, \alpha_2$ of loops on an oriented surface, it is natural to ask how to compute the minimum number of intersection points $m(\alpha_1, \alpha_2)$ of loops in these two classes. We show that for $\alpha_1\neq\alpha_2$ the number of terms in the Andersen-Mattes-Reshetikhin Poisson bracket of $\alpha_1$ and $\alpha_2$ is equal to $m(\alpha_1, \alpha_2)$. Chas found examples showing that a similar statement does not, in general, hold for the Goldman Lie bracket of $\alpha_1$ and $\alpha_2$. The main result of this paper in the case where $\alpha_1, \alpha_2$ do not contain different powers of the same loop first appeared in the unpublished preprint of the second author. In order to prove the main result for all pairs of $\alpha_1\neq \alpha_2$ we had to use the techniques developed by the first author in her study of operations generalizing Turaev's cobracket of loops on a surface.
Constraints on Fundamental Cosmological Parameters with Upcoming Redshifted 21 cm Observations

Constraints on cosmological parameters from upcoming measurements with the Mileura Wide-field Array Low Frequency Demonstrator (MWA LFD) of the redshifted 21 cm power spectrum are forecasted assuming a flat ΛCDM cosmology and assuming that the reionization of neutral hydrogen in the intergalactic medium occurs below a redshift of z = 8. We find that observations with the MWA LFD cannot constrain the underlying cosmology in this scenario. In principle, a similar experiment with a 10-fold increase in collecting area could provide useful constraints on the slope of the inflationary power spectrum, ns, and the running of the spectral index, αs, but these constraints are subject to the caveat that even a small reionization contribution could be confused with the cosmological signal. In addition to the redshifted 21 cm signal, we include two nuisance components in our analysis related to the systematics and astrophysical foregrounds present in low-frequency radio observations. These components are found to be well separated from the signal and contribute little uncertainty (<30%) to the measured values of the cosmological model parameters.