cssi/SciSciGPT-SciSciNet huggingface dataset:
Adolescent Use of the Monthly Contraceptive Injection

Study Objective: To compare weight and continuation among adolescents using monthly medroxyprogesterone acetate (MPA)/ethinyl estradiol cypionate (E2C) tri-monthly depot MPA (DMPA) and daily oral contraceptive pills (OCP). Design: Medical records were reviewed for body mass index demographics and sexual history at baseline; and weight and continuation at 3 6 9 and 12 months. Bivariate analyses were performed by method and continuation functions were compared by the log-rank and Wilcoxon tests. The effect of method on use duration was assessed by Cox regression. Setting: Hospital adolescent clinic. Participants: 12- to 21-year-old patients who initiated MPA/E2C DMPA or OCPs in 2001. Main Outcome Measures: Weight gain and method continuation. Results: MPA/E2C was initiated by 40 (18%) patients DMPA by 63 (28%) and OCPs by 119 (54% P < 0.001). OCP users were younger (P = 0.005) and more likely to be white privately insured and in school (P < 0.004) than MPA/E2C or DMPA users. Previous DMPA and OCP use pregnancy and sexually transmitted infections (STI) were more common among MPA/E2C than DMPA or OCP users (P = 0.001). Baseline BMI was lowest (P = 0.06) among DMPA users and MPA/E2C users were most likely to be overweight (P = 0.03). There were non-significant differences in weight change. Continuation functions differed by the method only in the first three months of use (P = 0.03). Leading reasons for discontinuation were unavailability of MPA/E2C (20%) bleeding with DMPA (22%) and forgetting OCPs (17%). Duration of use was independently associated with white race (P < 0.005) and STI-never (P < 0.0001) but not with method type. Conclusions: Although MPA/E2C use was associated with overweight status and early discontinuation it also was associated with previous use of other methods. For all methods poor continuation at one year supports the ongoing search for effective contraceptive alternatives. (authors)
Mapping Ocean Surface Topography with a Synthetic-Aperture Interferometry Radar

We propose to apply the technique of synthetic aperture radar interferometry to the measurement of ocean surface topography at spatial resolution approaching 1 km. The measurement will have wide ranging applications in oceanography, hydrology, and marine geophysics. The oceanographic and related societal applications are briefly discussed in the paper. To meet the requirements for oceanographic applications, the instrument must be flown in an orbit with proper sampling of ocean tides.
Highly Enantioselective Asymmetric Hydrogenation of α-Phthalimide Ketone: An Efficient Entry to Enantiomerically Pure Amino Alcohols

A new type of α-phthalimide ketones was hydrogenated in excellent enantioselectivity by using a Ru−(C3-TunePhos) complex as the catalyst. Up to 10 000 turnovers have been achieved in more than 99% ee in the hydrogenation reaction. A dynamic kinetic resolution study for the synthesis of threonine was performed, and high anti selectivity (>97:3) was observed for the first time. An efficient method to synthesize enantiomerically pure amino alcohols has been developed.
Magnetically and Baryonically Dominated Photospheric Gamma-Ray Burst Model Fits to Fermi-LAT Observations

We consider gamma-ray burst models where the radiation is dominated by a photospheric region providing the MeV Band spectrum, and an external shock region responsible for the GeV radiation via inverse Compton scattering. We parameterize the initial dynamics through an acceleration law {Gamma}{proportional_to}r {sup {mu}}, with {mu} between 1/3 and 1 to represent the range between an extreme magnetically dominated and a baryonically dominated regime, depending also on the magnetic field configuration. We compare these models to several bright Fermi-LAT bursts, and show that both the time-integrated and the time-resolved spectra, where available, can be well described by these models. We discuss the parameters which result from these fits, and discuss the relative merits and shortcomings of the two models.
On constraining electroweak-baryogenesis with inhomogeneous primordial nucleosynthesis

Abstract Primodial nucleosynthesis calculations are shown to be able to provide constraints on models of electroweak baryogenesis which produce a highly inhomogeneous distribution of the baryon-to-photon ratio. Such baryogenesis scenarios overproduce 4 He and/or 7 Li and can be ruled out henever a fraction f ≲3×10 −6 (100GeV/ T ) 3 of nucleated bubbles of broken-symmetry phase contributes ≳10% of the baryon number within a horizon volume.
Light-cone gauge quantization of 2d $\sigma$ models

Abstract This work describes the formulation of the manifestly ghost-free (spacetime) light-cone gauge for bosonic string theory with non-trivial spacetime metric, antisymmetric tensor, dilaton and tachyon fields. The action is a general two-dimensional sigma model, corresponding to a closed string theory with a second order action in the Polyakov picture. The spacetime fields must have a symmetry generated by a null, covariantly constant spacetime vector in order for the light-cone gauge to be accessible. Also, the theory must be Weyl invariant. The conditions for Weyl invariance are computed within the light-cone gauge, reproducing the usual beta functions. The calculation of the dilaton beta function and the critical dimension is somewhat novel in this ghost-free theory. Some exactly solvable light-cone theories are discussed.
Hypersonic Viscous Flows over Sphere Cones at High Angles of Attack

A PARABOL1ZED Navier-Stokes (PNS) prediction method developed to treat laminar flow over a sharp cone at incidence to a supersonic or hypersonic freestream has been extended to consider flow over a spherically blunted cone at angles of attack up to 38 deg. The basic method treats the flowfield between the body and the bow shock by one set of equations that are valid in both the viscous and inviscid regions. A description is given of the computational methods used, and results are compared with inviscid flowfield calculations and experimental data. The shock shape predictions were found to be in good agreement with most of the inviscid results as well as in reasonable agreement with some low Reynolds number heat transfer experimental data.
Electron microscopy of phase transformations in 1T-TaS2

(1993). Electron microscopy of phase transformations in 1T-TaS2. Phase Transitions: Vol. 43, No. 1-4, pp. 197-198.
The persistent impact of incidental experience.

As we perform daily activities—driving to work, unlocking the office door, or grabbing a coffee cup—our actions seem automatic and preprogrammed. Nonetheless, routine, well-practiced behavior is continually modulated by incidental experience: In repetitive experimental tasks, recent (~4) trials reliably influence performance and action choice. Psychological theories downplay the significance of sequential effects, explaining them as rapidly decaying perturbations of behavior, with no long-term consequences. We challenged this traditional perspective in two experiments designed to probe the impact of more distant experience, finding evidence for effects spanning up to a thousand intermediate trials. We present a normative theory in which these persistent effects reflect optimal adaptation to a dynamic environment exhibiting varying rates of change. The theory predicts a heavy-tailed decaying influence of past experience, consistent with our data, and suggests that individual incidental experiences are catalogued in a temporally extended memory utilized in order to optimize subsequent behavior.
Performance Bounds for Grouped Incoherent Measurements in Compressive Sensing

Compressive sensing (CS) allows for acquisition of sparse signals at sampling rates significantly lower than the Nyquist rate required for bandlimited signals. Recovery guarantees for CS are generally derived based on the assumption that measurement projections are selected independently at random. However, for many practical signal acquisition applications, including medical imaging and remote sensing, this assumption is violated as the projections must be taken in groups. In this paper, we consider such applications and derive requirements on the number of measurements needed for successful recovery of signals when groups of dependent projections are taken at random. We find a penalty factor on the number of required measurements with respect to the standard CS scheme that employs conventional independent measurement selection and evaluate the accuracy of the predicted penalty through simulations.
Core@shell nanomaterials: gold-coated magnetic oxide nanoparticles

The study of core@shell magnetic nanoparticles has a wide range of applications because of the unique combination of the nanoscale magnetic core and the functional shell. This report highlights some of the recent findings in the investigation of the synthesis, characterization and application of one important class of core@shell magnetic nanoparticles, i.e., magnetic nanoparticles coated with a gold shell (MNP@Au). The gold shell imparts the magnetic nanoparticles with many intriguing functional properties. Areas specifically highlighted in this report include strategies for the synthesis of MNP@Au nanoparticles, characterization of the core@shell nanostructures, and exploration of potential applications of the core@shell nanomaterials in terms of biological and catalytic interfacial reactivities. Implications of some of the research findings to address both fundamental and practical issues are also briefly discussed in an effort to further broaden the rapidly-emerging field of core@shell magnetic nanoparticles.
Matroids and Geometric Invariant Theory of torus actions on flag spaces

Abstract Let F / / T be a Geometric Invariant Theory quotient of a partial flag variety F = SL ( n , C ) / P by the action t ⋅ g P = t g P of the maximal torus T in SL ( n , C ) , where P is a parabolic subgroup containing T. The construction of F / / T depends upon the choice of a T-linearized line bundle L of F. This note concerns the case L = L λ is a very ample homogeneous line bundle determined by a dominant weight λ, meaning the associated character λ : T → C * extends to P and to no larger parabolic subgroup. If V λ denotes the irreducible representation of SL ( n , C ) with highest weight λ, and V λ [ μ ] is the isotypic component corresponding to a weight μ of the torus, then F / / T is equal to Proj ( ⊕ N = 0 ∞ V N λ [ N μ ] ) . The weight μ is used to twist the canonical T-linearization of L λ , where the canonical T-linearization of L λ is obtained by restricting the unique SL ( n , C ) -linearization of L λ to T. We apply a theorem of Gel'fand, Goresky, MacPherson, and Serganova concerning matroid polytopes to show that if V λ [ μ ] ≠ 0 then one gets a well-defined map F / / T → CP dim V λ [ μ ] − 1 by taking any basis of V λ [ μ ] . Equivalently, all the semistable partial flags are detected by degree one T-invariants provided V λ [ μ ] is nonzero. We also show that the closure of any T-orbit in F is projectively normal for the projective embedding ι λ : F → CP dim V λ − 1 .
On the global minimization of the value-at-risk

In this article, we consider the nonconvex minimization problem of the value-at-risk (VaR) that arise from financial risk analysis. By considering this problem as a special linear program (LP) with linear complementarity constraints (a bilevel LP to be more precise), we develop upper and lower bounds for the minimum VaR and show how the combined bounding procedures can be used to compute the latter value to global optimality. A numerical example is provided to illustrate the methodology. The Margaret A. Darrin Distinguished Professor in Applied Mathematics.
Conjugate addition of gem-borazirconocene alkanes to Michael acceptors

Abstract gem-Borazirconocenes, 1 , readily add across Michael acceptors in the presence of Cu(I)Br·SMe2, to afford 1,4-addition products in good to excellent yields. In the case of cycloalkenones diastereomers are produced, with the anti product favored. The selectivity with cyclopentenone is high (9:1), while with cyclohexenone it is less (3:1). In the present content, gem-borazirconocene alkanes can be regarded as α-hydroxyl anion equivalents.
Enantioselective Synthesis of 5,7-Bicyclic Ring Systems from Axially Chiral Allenes Using a Rh(I)-Catalyzed Cyclocarbonylation Reaction

A transfer of chirality in an intramolecular Rh(I)-catalyzed allenic Pauson-Khand reaction (APKR) to access tetrahydroazulenones, tetrahydrocyclopenta[c]azepinones and dihydrocyclopenta[c]oxepinones enantioselectively (22-99% ee) is described. The substitution pattern of the allene affected the transfer of chiral information. Complete transfer of chirality was obtained for all trisubstituted allenes, but loss of chiral information was observed for disubstituted allenes. This work constitutes the first demonstration of a transfer of chiral information from an allene to the 5-position of a cyclopentenone using a cyclocarbonylation reaction. The absolute configuration of the corresponding cyclocarbonylation product was also established, something that is rarely done.
On the Mechanism of Lubrication by Tricresylphosphate (TCP)—The Coefficient of Friction as a Function of Temperature for TCP on M-50 Steel

A pin-on-disk tribometer was used to study the coefficient of friction as a function of temperature for tricresylphosphate (TCP) on CVM M-50 tool steel under the following conditions: TCP was present in a liquid reservoir (bulk lubrication), and TCP was applied as a liquid layer directly to the disk (limited lubrication). Under limited lubrication conditions, experiments were performed in dry (< 100 ppm H2O) air, dry (< 20 ppm H2O) nitrogen, dry nitrogen with the disks heated to 700°C, then cooled to room temperature before the TCP was applied and the measurements made (preheated disks), and moist nitrogen using preheated disks. The coefficient of friction decreased at a characteristic temperature, Tr Tr values observed were: 265°C for bulk lubrication conditions in dry air, 225°C for limited lubrication conditions in dry air, and 215°C for limited lubrication conditions in dry nitrogen. The use of preheated disks produced a sharp failure temperature at 218°C which was taken as the temperature about which...
Probabilistic belief networks for genetic counseling

This paper describes a program, GenInfer, which uses belief networks to calculate risks of inheriting genetic disorders. GenInfer is based on Pearl's (J. Pearl, Artif. Intell. 29 (1986) 241-288) algorithm for fusion and propagation in probabilistic belief networks. It is written in Common Lisp. GenInfer can calculate genotypes for any family affected with any single-gene inherited disorder. Besides considering both negative and positive information in the pedigree. GenInfer takes into account additional information about the specific disorder as well as supplementary information for family members. The output consists of genotype probabilities for all family members and estimated genetic risks for prospective children of the consultands. Belief networks provide a way to calculate probabilities for systems of conditionally dependent variables. The impacts of various pieces of information are propagated and fused in such a way that, when equilibrium is reached, each proposition can be assigned a degree of belief consistent with the axioms of probability theory. In Pearl's algorithm, information is communicated through the network by messages sent between nodes. Pearl's basic algorithm cannot directly handle multiple-connected networks, which arise in the genetic counseling domain whenever a family pedigree includes consanguinity or more than one child per couple. GenInfer makes use of two cycle breaking methods, clustering and conditioning, to handle these situations.
The aromatic ene reaction.

An aryne intermediate produced by a hexadehydro-Diels–Alder reaction is shown to engage in an unusual — and before this work rare and inefficient — aromatic ene reaction to produce an isotoluene. This second reactive intermediate can then engage an external enophile resulting in a conjunctive cascade in which four C–C bonds and three rings are created without involvement of reagents or generation of by-products.
Sources of polarized ions and atoms

Abstract In this presentation I discuss methods of producing large quantities of polarized atoms and ions (Stern-Gerlach separation, optical pumping, and spin-exchange) as well as experimental methods of measuring the degree of polarization of atomic systems. The usefulness of polarized atoms in probing the microscopic magnetic surface properties of materials will also be discussed.
Compressibility of electrospun fiber mats

Compressive properties of electrospun fiber mats are reported for the first time. Mats of bisphenol-A polysulfone (PSU) and of poly(trimethyl hexamethylene terephthalamide) [PA 6(3)T] were electrospun and annealed over a range of temperatures spanning the glass transition temperature of each polymer. The data for applied stress versus mat solidity were found to be well-described by a power law of the form \( \sigma_{\text{zz}} = kE\left( {\phi^{n} - \phi_{0}^{n} } \right) \), where \( \sigma_{\text{zz}} \) is the applied stress and ϕ is solidity, in accord with the analysis of Toll (Polym Eng Sci 38(8):1337, 2004). The values of n range from 3.2 to 6 for PSU and from 8.0 to 20 for PA 6(3)T. The lowest values in each case were exhibited by mats annealed near the glass transition temperature of the fiber material. The values of n are independent of fiber diameter. The higher values of n are attributed to fiber slippage via a mechanism analogous to that of work hardening of metals. The values of kE can vary by an order of magnitude and were difficult to determine precisely, due to the nature of the power law and the inhomogeneity of the mats. The compressibility of electrospun mats in response to an applied stress is sufficiently large that it cannot be neglected in applications where large pressures may be involved, such as filtration or membrane separations. In addition to the initial solidity of the mats, the material compressibility and the operating pressure relevant to the application are important to describe the structure of electrospun mats quantitatively under conditions of use.
Neutral solar wind generated by lunar exospheric dust at the terminator

[1] We calculate the flux of neutral solar wind observed on the lunar surface at the terminator due to solar wind protons penetrating exospheric dust grains with (1) radii greater than 0.1 μm and (2) radii greater than 0.01 μm. For grains with radii larger than 0.1 μm, the ratio of the neutral solar wind flux produced by exospheric dust to the incident ionized solar wind flux is estimated to be ∼10−4–10−3 for solar wind speeds in excess of 800 km s−1 but much lower (<10−5) at average to slow solar wind speeds. However, when the smaller grain sizes are considered, this ratio is estimated to be ≥10−5 at all speeds and at speeds in excess of 700 km s−1 reaches ∼10−3. These neutral solar wind fluxes are easily measurable with current low-energy neutral atom instrumentation. Observations of neutral solar wind from the surface of the Moon would provide independent information on the distribution of very small dust grains in the lunar exosphere that would complement and constrain optical measurements at ultraviolet and visible wavelengths.
GENERATORS OF MAXIMAL ORDERS

Let R be the ring of algebraic integers in a number field K and let Λ be a maximal order in a finite dimensional semisimple K-algebra B. Building on our previous work [3], we compute the smallest number of algebra generators of Λ considered as an R-algebra. This reproves and vastly extends the results of P.A.B. Pleasants, who considered the case when B is a number field. In order to achieve our goal, we obtain several results about counting generators of algebras which have finitely many elements. These results should be of independent interest.
Remaining Technical Challenges and Future Plans for Oil-Free Turbomachinery

The application of oil-free technologies (foil gas bearings, solid lubricants, and advanced analysis and predictive modeling tools) to advanced turbomachinery has been underway for several decades. During that time, full commercialization has occurred in aircraft air cycle machines, turbocompressors, cryocoolers, and ever-larger microturbines. Emerging products in the automotive sector (turbochargers and superchargers) indicate that a high volume serial production of foil bearings is imminent. The demonstration of foil bearings in auxiliary power units and select locations in propulsion gas turbines illustrates that such technology also has a place in these future systems. Foil bearing designs, predictive tools, and advanced solid lubricants that can satisfy anticipated requirements have been reported, but a major question remains regarding the scalability of foil bearings to ever-larger sizes to support heavier rotors. In this paper, the technological history, primary physics, engineering practicalities, and existing experimental and experiential database for scaling foil bearings are reviewed, and the major remaining technical challenges are identified.
Locally Optimally Emitting Clouds and the Origin of Quasar Emission Lines

The similarity of quasar line spectra has been taken as an indication that the emission line clouds have preferred parameters, suggesting that the environment is subject to a fine-tuning process. We show here that the observed spectrum is a natural consequence of powerful selection effects. We computed a large grid of photoionization models covering the widest possible range of cloud gas density and distance from the central continuum source. For each line only a narrow range of density and distance from the continuum source results in maximum reprocessing efficiency, corresponding to "locally optimally emitting clouds" (LOCs). These parameters depend on the ionization and excitation potentials of the line and its thermalization density. The mean QSO line spectrum can be reproduced by simply adding together the full family of clouds, with an appropriate covering fraction distribution. The observed quasar spectrum is a natural consequence of the ability of various clouds to reprocess the underlying continuum, and can arise in a chaotic environment with no preferred pressure, gas density, or ionization parameter.
Annulation strategies for benzo[b]fluorene synthesis: efficient routes to the kinafluorenone and WS-5995 antibiotics.

Intramolecular palladium-mediated arylation approaches to benzo[b]fluorenes have been investigated. The methodology has been applied in a short synthesis of tri-O-methylkinafluorenone, providing an effective alternative to Friedel−Crafts-based approaches. During the course of this work, an acid-promoted quinolactonization of naphthoquinones was also developed, providing direct access to either ortho or para isomers as desired. Application of this methodology in syntheses of the antibiotics WS-5995A, WS-5995C, and functional analogues was demonstrated, and antitumoral activity of this class was determined.
Shortcuts to nuclear structure: lessons in Hartree-Fock, RPA, and the no-core shell model

While the no-core shell model is a state-of-the-art microscopic approach to low-energy nuclear structure, its intense computational requirements lead us to consider time-honored approximations such as the Hartree–Fock (HF) approximation and the random phase approximation (RPA). We review RPA and point out some common misunderstandings, then apply HF + RPA to the no-core shell model. Here the main issue is appropriate treatment of contamination by spurious center-of-mass motion.
Two Perspectives on Learning the Organizational Ombudsman Role

This article explores the challenges in learning the role of the organizational ombudsman from the perspectives of two practitioners—one an experienced workplace mediator, the other a student of conflict resolution. The discussion of the shift in thinking, as well as skills needed to transition into the various facets of organizational ombudsman work, combines concepts from ombudsman theory with insights on enhancing ombudsman practice. The authors provide observations and recommendations based on their own experiences assuming the roles of a new ombudsman, including reflective practice and partnering, coaching with employees, and expanding systemic engagements with and cultural knowledge of organizations.
Least and Greatest Fixed Points in Linear Logic

The first-order theory of MALL (multiplicative, additive linear logic) over only equalities is a well-structured but weak logic since it cannot capture unbounded (infinite) behavior. Instead of accounting for unbounded behavior via the addition of the exponentials (! and ?), we add least and greatest fixed point operators. The resulting logic, which we call μMALL, satisfies two fundamental proof theoretic properties: we establish weak normalization for it, and we design a focused proof system that we prove complete with respect to the initial system. That second result provides a strong normal form for cut-free proof structures that can be used, for example, to help automate proof search. We show how these foundations can be applied to intuitionistic logic.
Minimal Unitary Realizations of Exceptional U-duality Groups and Their Subgroups as Quasiconformal Groups

We study the minimal unitary representations of noncompact exceptional groups that arise as U-duality groups in extended supergravity theories. First we give the unitary realizations of the exceptional group E8(−24) in SU*(8) as well as SU(6,2) covariant bases. E8(−24) has E7 × SU(2) as its maximal compact subgroup and is the U-duality group of the exceptional supergravity theory in d = 3. For the corresponding U-duality group E8(8) of the maximal supergravity theory the minimal realization was given in [1]. The minimal unitary realizations of all the lower rank noncompact exceptional groups can be obtained by truncation of those of E8(−24) and E8(8). By further truncation one can obtain the minimal unitary realizations of all the groups of the "Magic Triangle". We give explicitly the minimal unitary realizations of the exceptional subgroups of E8(−24) as well as other physically interesting subgroups. These minimal unitary realizations correspond, in general, to the quantization of their geometric actions as quasi-conformal groups as defined in [2].
Pathways for nucleophilic substitution at silicon. A molecular orbital approach

Minimum strain energy conformations determined by molecular mechanics calculations are used as input structures for a molecular orbital treatment designed to model inversion and retention pathways ...
A bound for the Castelnuovo–Mumford regularity of log canonical varieties

Abstract In this note, we give a bound for the Castelnuovo–Mumford regularity of a homogeneous ideal I in terms of the degrees of its generators. We assume that I defines a local complete intersection with log canonical singularities.
Structural characterization of cobalt catalysts on a silica support

Abstract In situ X-ray diffraction was employed to characterize the structure of several cobalt catalysts on a silica support. The catalysts were reduced in flowing hydrogen at 350 °C for about 16 h and X-ray diffraction patterns were collected. After reduction metallic cobalt was found to be present in the hcp and fcc forms in the ratio of 7:3 and 17% of the hexagonal close-packed planes were found to be faulted. If surface atoms adjacent to stacking faults are sources of active sites, the density of active sites was estimated to be 4.0 × 10 19 per gram of cobalt.
Reciprocal Relativity of Noninertial Frames and the Quaplectic Group

The frame associated with a classical point particle is generally noninertial. The point particle may have a nonzero velocity and force with respect to an absolute inertial rest frame. In time–position–energy–momentum-space {t, q, p, e}, the group of transformations between these frames leaves invariant the symplectic metric and the classical line element ds2 = d t2. Special relativity transforms between inertial frames for which the rate of change of momentum is negligible and eliminates the absolute rest frame by making velocities relative but still requires the absolute inertial frame. The Lorentz group leaves invariant the symplectic metric and the line elements $$ds^{2} = -dt^{2} + \frac{1}{c^{2}} dq^{2}$$ and $$d \mu^{2} = dp^{2}-\frac{1}{c^{2}}de^{2}$$ . General relativity for particles under only the influence of gravity avoids the issue of noninertial frames as all particles follow geodesics and hence have locally inertial frames. For other forces, the question of the absolute inertial frame remains.) Born conjectured that the line element should be generalized to the pseudo-orthogonal metric $$ds^{2} = -d t^{2}+\frac{1}{c^{2}} dq^{2} + \frac{1}{b^{2}}(dp^{2}-\frac{1}{c^{2}}de^{2})$$ . The group leaving this metrics and the symplectic metric invariant is the pseudo-unitary group of transformations between noninertial frames. We show that these transformations also eliminate the need for an absolute inertial frame by making forces relative and bounded by b and so embodies a relativity that is shape reciprocal in the sense of Born. The inhomogeneous version of this group is naturally the semidirect product of the pseudo-unitary group with the nonabelian Heisenberg group. This is the quaplectic group.
Income distribution and price controls: Targeting a social safety net during economic transition

Abstract During the ongoing post-communist economic transitions, the relative well-being of many people is changing rapidly, and governments are not well positioned to accurately measure individual living standards. Under such circumstances, continued price controls over basic consumer goods within the state sector, and the associated queuing, can form a serviceable device for targeting poor people for subsidies. With a fixed-price state sector and free-price parallel markets, rich people might choose to avoid queues and shop in the free markets, while poor people would prefer to pay low nominal prices and queue in the state sector. The targeting of subsidies through queues, therefore, can be accomplished even if the government has no information concerning individual income or living standards. When the alternative to price controls is a poorly targeted explicit social safety net, the resource cost of queues might be more than offset by an improvement in the targeting of subsidies.
Analysis of poling induced cracking in thick walled cylinders

Stresses and electric fields induced in the poling processes of both polycrystalline and single crystal thick walled cylinders are investigated and compared using a finite element analysis together with a micromechanical ferroelectric constitutive law. The analysis reveals that the polarization process begins at the inner diameter and spreads outward through the cylinder as the applied electric potential is increased. The piezoelectric strain and the remnant strain produce strain fields that are not compatible with the geometry. In the single crystal material the poling is not uniform. It is affected by the angle between the crystal orientation and the electric field direction.
p -adic properties of division polynomials and elliptic divisibility sequences

For a fixed rational point P ∈ E (K) on an elliptic curve, we consider the sequence of values (F n (P)) n ≥1 of the division polynomials of E at P. For a finite field we prove that the sequence is periodic. For a local field we prove (under certain hypotheses) that there is a power q=p e so that for all m≥1, the limit of exists in K and is algebraic over We apply this result to prove an analogous p-adic limit and algebraicity result for elliptic divisibility sequences.
The Energy of a Smooth Metric Measure Space and Applications

We introduce and study the notion of the energy of a smooth metric measure space, which includes as special cases the Yamabe constant and Perelman’s ν-entropy. We then investigate some properties the energy shares with these constants, in particular its relationship with the κ-noncollapsing property. Finally, we use the energy to prove a precompactness theorem for the space of compact quasi-Einstein smooth metric measure spaces, in the spirit of similar results for Einstein metrics and gradient Ricci solitons.
Accurate Hydrogen Spectral Simulations with a Compact Model Atom

Many large-scale numerical simulations of astrophysical plasmas must also reproduce the hydrogen ionization and the resulting emission spectrum, in some cases quite accurately. We describe a compact model hydrogen atom that can be readily incorporated into such simulations. It reproduces the recombination efficiency and line spectrum predicted by much larger calculations for a very broad range of densities and temperatures. Uncertainties in hydrogen collision data are the largest source of differences between our compact atom and predictions of more extensive calculations and underscore the need for accurate atomic data.
Prostate cancer treatment for economically disadvantaged men: a comparison of county hospitals and private providers.

BACKGROUND. The authors compared the types of treatments prostate cancer patients received from county hospitals and private providers as part of a statewide public assistance program. METHODS. This was a cohort study of 559 men enrolled in a state-funded program for low-income patients known as Improving Access, Counseling, and Treatment for Californians With Prostate Cancer (IMPACT). Multinomial regression was used to compare types of treatments patients received from different providers. RESULTS. Between 2001 and 2006, 315 (56%) participants received treatment from county hospitals and 244 (44%) from private providers. There were no significant betweengroup differences with respect to age (P ¼ .22), enrollment year (P ¼ .49), Charlson comorbidity index (P ¼ .47), Gleason sum (P ¼ .33), clinical T stage (P ¼ .36), prostate-specific antigen (P ¼ .39), or D’Amico risk criteria (P ¼ .45). Participants treated by private providers were more likely than those treated in county hospitals to be white (35% vs 10%, P 41=2 times more likely to receive primary androgen deprivation (OR, 4.71; 95% CI, 2.15-10.36) than surgery. CONCLUSIONS. In this economically disadvantaged cohort, prostate cancer treatments differed significantly between county hospitals and private providers. These data reveal substantial variations in treatment patterns between different types of healthcare institutions that—given the implications for health policy and quality of care—merit further scrutiny. Cancer 2010;116:1378– 84. V C 2010 American Cancer Society.
A convenient method for the preparation of hydroxamic acids

Abstract A one-step conversion of carboxylic acid to hydroxamic acid, under neutral pH conditions is described. This simple, selective and efficient method was applied to a wide range of aliphatic/aromatic carboxylic acid derivatives that contain hydroxyl, halo, ester and other base sensitive groups as substituents. The method utilizes cheaply available reagents and hence it is a practical and cost effective strategy, compared to the other methods available in the literature.
Non-peptide oxytocin antagonists: identification and synthesis of a potent camphor aminosuccinimide

Abstract The structure activity relationships of a series of non-peptide oxytocin antagonists containing a camphor aminosuccinimide as a key structural element were investigated. A potent and selective analog was identified and prepared in diastereomerically pure form starting from aspartic acid.
Hole on a stripe in a spinless fermion model

In the spinless fermion model on a square lattice with infinite nearest-neighbor repulsion, holes doped into the half-filled ordered state form stripes which, at low doping, are stable against phase separation into an ordered state and a hole-rich metal. Here we consider transport of additional holes along these stripes. The motion of a single hole on a stripe is mapped to a one-dimensional problem, a variational wave function is constructed and the energy spectrum is calculated and compared to energies obtained by exact diagonalization.
Steady states of harmonic oscillator chains and shortcomings of harmonic heat baths

Abstract We study properties of steady states (states with time-independent operators) of systems of coupled harmonic oscillators. Formulas are derived showing how an adiabatic change of the Hamiltonian transforms one steady state into another. It is shown that for infinite systems, sudden change of the Hamiltonian also tends to produce steady states, after a transition period of oscillations. These naturally arising steady states are compared to the maximum-entropy state (the thermal state) and are seen not to coincide in general. The approach to equilibrium of subsystems consisting of n coupled harmonic oscillators has been widely studied, but only in the simple case where n =1. The power of our results is that they can be applied tomore complex subsystems, where n > 1. It is shown that the use of coupled harmonic oscillators as heat baths models is fraught with some problems that do not appear in the simple n =1 case. Specifically, the thermal states that are thought to be achievable through hard-sphere collisions with heat-bath particles can generally not be achieved with harmonic coupling to the heat-bath particles, except approximately when the coupling is weak.
2-Isopropylapoisopinocampheylborane, an improved reagent for the asymmetric hydroboration of representative prochiral alkenes

Abstract A new hydroborating agent, 2-isopropylapoisopinocampheylborane ( i PraBH 2 , 2f ), achieves the asymmetric hydroboration of representative prochiral alkenes in higher optical purities than that achieved by the borane derivatives, 2-organylapoisopinocampheylboranes (R = Me, IpcBH 2 ; R = Et, EapBH 2 ; and R = Ph, PapBH 2 ) previously examined.
The Extroverted Firm: How External Information Practices Affect Innovation and Productivity

We gather detailed data on organizational practices and information technology (IT) use at 253 firms to examine the hypothesis that external focus---the ability of a firm to detect and therefore respond to changes in its external operating environment---increases returns to IT, especially when combined with decentralized decision making. First, using survey-based measures, we find that external focus is correlated with both organizational decentralization, and IT investment. Second, we find that a cluster of practices including external focus, decentralization, and IT is associated with improved product innovation capabilities. Third, we develop and test a three-way complementarities model that indicates that the combination of external focus, decentralization, and IT is associated with significantly higher productivity in our sample. We also introduce a new set of instrumental variables representing barriers to IT-related organizational change and find that our results are robust when we account for the potential endogeneity of organizational investments. Our results may help explain why firms that operate in information-rich environments such as high-technology clusters or areas with high worker mobility have experienced especially high returns to IT investment and suggest a set of practices that some managers may be able to use to increase their returns from IT investments. This paper was accepted by Sandra Slaughter, information systems.
‘But this is a park’! The paradox of public space in a Buenos Aires ‘no man's land’

Drawing upon qualitative fieldwork, this paper analyzes the occupation of an abandoned park in the south of Buenos Aires by the city's urban poor, delineating the implications of this incident for notions of citizenship in the context of deeply fragmented social rights. While public space has historically been understood as an expression of the universality of rights bearing membership in a political community, I show how this universalism became the object of struggle during a conflict over the park between the local middle class and squatters, many of which were of immigrant origin. The discourses mobilized by various social groups blurred the distinction between citizenship as a set of legal–formal rights versus a project of normative inclusion. While public space is juridically constructed as universal, particularistic claims to these spaces are imbued with increased legitimacy in a context in which social rights – conceived as a set of provisions guaranteed by the state under a regime of liberal citi...
Biochemistry of Mobile Zinc and Nitric Oxide Revealed by Fluorescent Sensors

Biological mobile zinc and nitric oxide (NO) are two prominent examples of inorganic compounds involved in numerous signaling pathways in living systems. In the past decade, a synergy of regulation, signaling, and translocation of these two species has emerged in several areas of human physiology, providing additional incentive for developing adequate detection systems for Zn(II) ions and NO in biological specimens. Fluorescent probes for both of these bioinorganic analytes provide excellent tools for their detection, with high spatial and temporal resolution. We review the most widely used fluorescent sensors for biological zinc and nitric oxide, together with promising new developments and unmet needs of contemporary Zn(II) and NO biological imaging. The interplay between zinc and nitric oxide in the nervous, cardiovascular, and immune systems is highlighted to illustrate the contributions of selective fluorescent probes to the study of these two important bioinorganic analytes.
Performance of FORTRAN and C GPU Extensions for a Benchmark Suite of Fourier Pseudospectral Algorithms

A comparison of PGI Open ACC, FORTRAN CUDA, and Nvidia CUDA pseudospectral methods on a single GPU and GCC FORTRAN on single and multiple CPU cores is reported. The GPU implementations use CuFFT and the CPU implementations use FFTW. Porting pre-existing FORTRAN codes to utilize a GPUs is efficient and easy to implement with Open ACC and CUDA FORTRAN. Example programs are provided.
Phase separation kinetics in immiscible liquids

The kinetics of phase separation in the succinonitrile-water system are being investigated. Experiments involve initial physical mixing of the two immiscible liquids at a temperature above the consolute, decreasing the temperature into the miscibility gap, followed by imaging of the resultant microstructure as it evolves with time. Refractive index differences allow documentation of the changing microstructures by noninvasive optical techniques without the need to quench the liquid structures for analysis.
Machine learning methods in the computational biology of cancer

The objectives of this Perspective paper are to review some recent advances in sparse feature selection for regression and classification, as well as compressed sensing, and to discuss how these might be used to develop tools to advance personalized cancer therapy. As an illustration of the possibilities, a new algorithm for sparse regression is presented and is applied to predict the time to tumour recurrence in ovarian cancer. A new algorithm for sparse feature selection in classification problems is presented, and its validation in endometrial cancer is briefly discussed. Some open problems are also presented.
Tribological Performance of Diamond and Diamondlike Carbon Films at Elevated Temperatures

In this study, the authors investigated the tribological performance of diamond and diamondlike carbon (DLC) films as a function of temperature. Both films were deposited on silicon carbide (SiC) by microwave plasma chemical vapor deposition and ion-beam deposition processes. Tribological tests were performed on a reciprocating wear machine in open air (20 to 30% relative humidity) and under a 10 N load using SiC pins. For the test conditions explored, the steady-state friction coefficients of test pairs without a diamond or DLC film were 0.7 to 0.9 and the average wear rates of pins were 10−5 to 10−7 mm3/N·m, depending on ambient temperature. DLC films reduced the steady-slate friction coefficients of the test pairs by factors of three to five and the wear rates of pins by two to three orders of magnitude. Low friction coefficients were also obtained with the diamond films, but wear rates of the counterface pins were high due to the very abrasive nature of these films. The wear of SiC disks coated with e...
A laminar cortical model of stereopsis and three-dimensional surface perception

A laminar cortical model of stereopsis and later stages of 3D surface perception is developed and simulated. The model describes how initial stages of monocular and binocular oriented filtering interact with later stages of 3D boundary formation and surface filling-in in the lateral geniculate nucleus and cortical areas V1, V2, and V4. In particular, it details how interactions between layers 4, 3B, and 2/3A in V1 and V2 contribute to stereopsis, and clarifies how binocular and monocular information combine to form 3D boundary and surface representations. Along the way, the model modifies and significantly extends the disparity energy model. Neural explanations are given for psychophysical data concerning: contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, Panum's limiting case, the Venetian blind illusion, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and various lightness illusions. By relating physiology to psychophysics, the model provides new functional insights and predictions about laminar cortical architecture.
A comparative analysis of numerical approaches to the mechanics of elastic sheets

Numerically simulating deformations in thin elastic sheets is a challenging problem in computational mechanics due to destabilizing compressive stresses that result in wrinkling. Determining the location, structure, and evolution of wrinkles in these problems has important implications in design and is an area of increasing interest in the fields of physics and engineering. In this work, several numerical approaches previously proposed to model equilibrium deformations in thin elastic sheets are compared. These include standard finite element-based static post-buckling approaches as well as a recently proposed method based on dynamic relaxation, which are applied to the problem of an annular sheet with opposed tractions where wrinkling is a key feature. Numerical solutions are compared to analytic predictions of the ground state, enabling a quantitative evaluation of the predictive power of the various methods. Results indicate that static finite element approaches produce local minima that are highly sensitive to initial imperfections, relying on a priori knowledge of the equilibrium wrinkling pattern to generate optimal results. In contrast, dynamic relaxation is much less sensitive to initial imperfections and can generate low-energy solutions for a wide variety of loading conditions without requiring knowledge of the equilibrium solution beforehand.