cssi/SciSciGPT-SciSciNet huggingface dataset:
The positive Bergman complex of an oriented matroid

We study the positive Bergman complex B + (M) of an oriented matroid M, which is a certain subcomplex of the Bergman complex B(M) of the underlying unoriented matroid M. The positive Bergman complex is defined so that given a linear ideal I with associated oriented matroid MI, the positive tropical variety associated with I is equal to the fan over B + (MI). Our main result is that a certain "fine" subdivision of B + (M) is a geometric realization of the order complex of the proper part of the Las Vergnas face lattice of M. It follows that B + (M) is homeomorphic to a sphere. For the oriented matroid of the complete graph Kn, we show that the face poset of the "coarse" subdivision of B + (Kn) is dual to the face poset of the associahedron An-2, and we give a formula for the number of fine cells within a coarse cell.
Indigo: user-level support for building distributed shared abstractions

Distributed systems that consist of workstations connected by high performance interconnects offer computational power comparable to moderate size parallel machines. It is desirable that such workstation clusters can also be programmed the same way as shared memory machines. We develop a portable, user-level library, called Indigo, that can be used to program a variety of state sharing techniques. In particular, Indigo can be used to program DSM protocols as well as distributed shared abstractions where objects can be fragmented/replicated and consistency actions are customized according to application needs. We present an evaluation of Indigo by using its calls to implement a distributed shared memory system as well as shared abstractions for a number of applications.
Non-stationary noise estimation using dictionary learning and Gaussian mixture models

Stationarity of the noise distribution is a common assumption in image processing. This assumption greatly simplifies denoising estimators and other model parameters and consequently assuming stationarity is often a matter of convenience rather than an accurate model of noise characteristics. The problematic nature of this assumption is exacerbated in real-world contexts, where noise is often highly non-stationary and can possess time- and space-varying characteristics. Regardless of model complexity, estimating the parameters of noise dis- tributions in digital images is a difficult task, and estimates are often based on heuristic assumptions. Recently, sparse Bayesian dictionary learning methods were shown to produce accurate estimates of the level of additive white Gaussian noise in images with minimal assumptions. We show that a similar model is capable of accu- rately modeling certain kinds of non-stationary noise processes, allowing for space-varying noise in images to be estimated, detected, and removed. We apply this modeling concept to several types of non-stationary noise and demonstrate the model’s effectiveness on real-world problems, including denoising and segmentation of images according to noise characteristics, which has applications in image forensics.
TeV scale supersymmetric standard model and brane world

Recently we proposed a TeV-scale Supersymmetric Standard Model in which the gauge coupling unification is as precise (at one loop) as in the MSSM, and occurs in the TeV range. One of the key ingredients of this model is the presence of new states neutral under SU(3)c ⊗SU(2)w but charged under U(1)Y whose mass scale is around that of the electroweak Higgs doublets. In this paper we show that introduction of these states allows to gauge novel anomaly free discrete (as well as continuous) symmetries (similar to “lepton” and “baryon” numbers) which suppress dangerous higher dimensional operators and stabilize proton. Moreover, we argue that these gauge symmetries are essential for successfully generating small neutrino masses via a recently proposed higher dimensional mechanism. Furthermore, the mass hierarchy between the up and down quarks (e.g., t vs. b) can be explained without appealing to large tan�, and the µ-term for the electroweak Higgs doublets (as well as for the new states) can be generated. We also discuss various phenomenological implications of our model which lead to predictions testable in the present or near future collider experiments. In particular, we point out that signatures of scenarios with high vs. low unification (string) scale might be rather different. This suggest a possibility that the collider experiments may distinguish between these scenarios even without a direct production of heavy Kaluza-Klein or string states.
Help-Seeking and Help-Giving as an Organizational Routine: Continual Engagement in Innovative Work

The literature on help-giving behavior identifies individual-level factors that affect a help-giver's decision to help another individual. Studying a context in which work was highly interdependent and helping was pervasive, however, we propose that this emphasis on the initial point of consent is incomplete. Instead, we find that workplace help-seeking and help-giving can be intertwined behaviors enacted through an organizational routine. Our research, therefore, shifts the theoretical emphasis from one of exchange and cost to one of joint engagement. More specifically, we move beyond the initial point of consent to recast help-seeking and help-giving as an interdependent process in which both the help-seeker and the help-giver use cognitive and emotional moves to engage others and thereby propel a helping routine forward. In contrast to the existing literature, an organizational routines perspective also reveals that helping need not be limited to dyads, and that the helping routine is shaped by the work context in which help is sought. Finally, we extend these insights to the literatures on routines and coordination and debate how our results might generalize even if helping is not part of an organizational routine
Gravity currents with residual trapping

Abstract Motivated by geological carbon dioxide (CO 2 ) storage, we present a simple model for the migration of immiscible gravity currents with constant residual trapping in a two-dimensional confined and sloping aquifer. Residual trapping acts as a loss-term, it reduces the current volume as long as the CO 2 plume continues to migrate. Comparison with numerical results shows that the hyperbolic limit of the governing equations is a good approximation for currents with large mobility. In gently sloping aquifers, the current evolution is divided into an initial stage, with power-law decrease of volume, and a later stage, characterized by a rapid decay of the plume volume. Our results suggest that the efficient residual trapping in dipping aquifers may allow CO 2 storage in aquifers lacking structural closure, if CO 2 is injected far enough from the outcrop of the aquifer. However, the poor vertical sweep may lead to very long migration distances that may limit the storage capacity of in such aquifers. All results presented here are based on [M.A. Hesse, F.M. Orr Jr, H.A. Tchelepi, Gravity currents with residual trapping, J. Fluid Mech. 611 (2008) 35–60.].
The Partial-Fractions Method for Counting Solutions to Integral Linear Systems

We present a new tool to compute the number $\phi_{\bf A} (b)$ of integer solutions to the linear system $$ x \geq 0, A x = b, $$ where the coefficients of $A$ and $b$ are integral. $\phi_{\bf A} (b)$ is often described as a vector partition function. Our methods use partial fraction expansions of Euler's generating function for $\phi_{\bf A} (\b)$. A special class of vector partition functions are Ehrhart (quasi-)polynomials counting integer points in dilated polytopes.
Kernel based quadrature on spheres and other homogeneous spaces

Quadrature formulas for spheres, the rotation group, and other compact, homogeneous manifolds are important in a number of applications and have been the subject of recent research. The main purpose of this paper is to study coordinate independent quadrature (or cubature) formulas associated with certain classes of positive definite and conditionally positive definite kernels that are invariant under the group action of the homogeneous manifold. In particular, we show that these formulas are accurate--optimally so in many cases--and stable under an increasing number of nodes and in the presence of noise, provided the set $$X$$ X of quadrature nodes is quasi-uniform. The stability results are new in all cases. In addition, we may use these quadrature formulas to obtain similar formulas for manifolds diffeomorphic to $$\mathbb S ^n$$ S n , oblate spheroids for instance. The weights are obtained by solving a single linear system. For $$\mathbb S ^2$$ S 2 , and the restricted thin plate spline kernel $$r^2\log r$$ r 2 log r , these weights can be computed for two-thirds of a million nodes, using a preconditioned iterative technique introduced by us.
Stress reduction in an isotropic plate with a hole by applied induced strains

Recently there has been much interest in adaptive structures that can respond to a varying environment by changing their properties. Shape memory alloys and piezoelectric materials can be used as induced strain actuators to reduce stresses in the regions of stress concentration. The objective of our work was to find the maximum possible reduction in the stress concentration factor in anisotropic plate with a hole by applying induced strains in a small area near the hole.
Do Unverifiable Disclosures Matter? Evidence from Peer-to-Peer Lending

ABSTRACT: The role of disclosure in attenuating market inefficiencies has been the subject of extensive research. While costless, voluntary, and unverifiable disclosures are unlikely to be credible...
The Impact of Conditional Cash Transfers on Consumption and Investment in Nicaragua

Abstract This article examines the impact of a Nicaraguan conditional cash transfer programme on measures of expenditures and productive investment. Despite clear evidence from a randomised evaluation that the programme increased current expenditures, there is little evidence that it increased agricultural or non-agricultural investment. An estimated marginal propensity to consume out of the transfers of nearly one, combined with no effect of cumulative past transfers on current consumption, corroborate the direct evidence on investment. In contrast to gains made in human capital investment, the potential for long term increases in consumption as a result of other forms of increased investment may be limited.
Fluorinated 1-Phenyl-1H-tetrazol-5-yl Sulfone Derivatives as General Reagents for Fluoroalkylidene Synthesis

Julia-Kocienski olefination reagents 1-fluoropropyl, (cyclopropyl)fluoromethyl, 1-fluoro-2-methyl-2-propenyl and 1-fluoro-5-hexenyl 1-phenyl-1H-tetrazol-5-yl (PT) sulfones were prepared by metalation followed by electrophilic fluorination. Although metalation-fluorination of n-propyl, 5-hexenyl and (cyclopropyl)methyl PT-sulfones proceeded under homogeneous conditions, fluorination of 2-methyl-2-propenyl PT-sulfone required heterogeneous fluorination conditions. Condensation reactions of fluoro PT-sulfones with aldehydes resulted in fluoroalkylidenes in high yields. Screening of olefination conditions showed that stereoselectivity depended on reagent and carbonyl structure and can in many cases be tuned either towards E- or Z-selectivity. For example, LHMDS-mediated condensations of 1-fluoropropyl PT-sulfone in the presence of MgBr2·OEt2 were Z-selective with electron-rich aromatic aldehydes, a hindered aromatic aldehyde and cinnamaldehyde. Low temperature KHMDS-mediated condensations were E-selective with electron-rich and electron-deficient aromatic aldehydes and Z-selective with n-octanal. Dialkyl, aryl alkyl and diaryl ketones reacted as well to give fluoro olefin products in 71–99% yields.
Calculation of a Propagator on a Riemann Surface

A field theory is considered on a Riemann surface of genus p , where the field is a section of a holomorphic line bundle ξ with Chern number p - 1. When ξ has no holomorphic section, one can calculate the propagator explicitly. As an application the expectation value of the energy-momentum tensor is computed.
Synthesis and characterization of water-soluble amino fullerene derivatives

A series of amino-substituted methanofullerene derivatives were prepared by mono-, tris-, and hexa-Bingel−Hirsch reactions using an N-protected malonate derivative. Upon scission of the protecting groups, the e,e,e-tris- and octahedral Th hexa-methano amino fullerenes were found to be among the most water-soluble fullerene derivatives yet prepared. 3He NMR data on corresponding adducts of 3He@C60 helped verify the assigned structures. UV spectral studies confirmed the influence of aggregation on solubility of these adducts in water.
Automatic visual inspection

The growing popularity of automatic inspection techniques was evidenced by the attendance at a conference on automatic inspection and quality control in Chicago last October. At that conference, several reasons were presented to justify the development and implementation of automatic industrial quality control systems. These include: (1) releasing workers from tedious or repetitive tasks, (2) enabling precise and continuous inspection in inaccessible environments or under hazardous conditions, such as measuring the thickness of hot steel, (3) improving inspection system reliability, and (4) improving inspection system predictability.
Modeling Sulfur Dioxide Capture in a Pulverized Coal Combustor

The formation and capture of sulfur dioxide in a pulverized coal combustor is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-two Dimensional), originally developed at Brigham Young University, has been used to simulate combustion of the pulverized coal. This paper represents part of project to investigate simultaneously enhancing sulfur capture and particulate agglomeration in combustor effluents. Results from the code have been compared to experimental data obtained from MTCI's (Manufacturing Technology and Conversion International) test pulse combustor, which generates sound pressure levels of ∼180 dB. The overall goal behind the pulse combustor program at MTCI is to develop combustors for stationary gas turbines that use relatively inexpensive coal-based fuels. This study attempts to model the capture of sulfur dioxide when injected into a pulse combustor firing micronized coal. While this work does not presume to model the complex gas flow-field generated by the pulsating flow, the effects of the acoustic field are expressed by increased heat and mass transfer to the particles (coal/sorbent) in question. A comprehensive calcination-sintering-sulfation model for single particles was used to model the capture of sulfur dioxide by limestone sorbent. Processes controlling sulfation are external heat and mass transfer, pore diffusion, diffusion through the product layer of CaSO4, sintering, and calcination. The model was incorporated into the PCGC-2 program. Comparisons of exit concentrations of SO 2 showed a fairly good agreement (within ∼10 percent) with the experimental results from MTCI.
Critical impact initiation energies for three HTPB propellants

The instrumented drop weight impact machine is one possible candidate for establishing the hazard response of solid rocket propellants to impact. The plastic work done on the propellant prior to initiation can be measured by equating it to the loss in drop weight kinetic energy, provided energy storage in the machine is negligible. Three HTPB/AP propellants were studied with an instrumented impact machine. Data are given for impact velocities ranging from 5.54 m/s, at which no sample was consumed, to 16.14 m/s, at which nearly all of the sample was consumed. These data are interpreted in terms of a proposed mechanism based on other impact tests. On bare steel tools ignition, as opposed to hot spot formation, is assumed to occur at impact velocities greater than 10.3 m/s, when more than 90% of the sample is consumed during the test. At higher impact velocities, for the present data, times to reaction are short and the change in impactor kinetic energy during the initiation delay is defined as the critical initiation energy. Some of the trends in the data are correlated with the propellant formulations. The present test is contrasted with others suggested for impact sensitivity characterization in terms of both initiation threshold and response severity.
Thirty-three cases of body dysmorphic disorder in children and adolescents.

ABSTRACT Objective Body dysmorphic disorder (BDD), a preoccupation with a nonexistent or slight defect in appearance, usually begins during adolescence. Because there have been no studies of the clinical features of BDD in children and adolescents, the authors assessed these features in the largest series to date. Method Thirty-three children and adolescents with DSM-IV BDD were assessed for demographic characteristics, phenomenology, associated psychopathology, and treatment history and response. Results Bodily preoccupations most often focused on the skin (61%) and hair (55%). All subjects had associated compulsive behaviors, most often camouflaging (e.g., with clothing) in 94%, comparing with others (87%), and mirror checking (85%). Ninety-four percent reported impairment in social functioning and 85% in academic or job functioning due to BDD. Thirty-nine percent had had psychiatric hospitalizations, and 21% had made a suicide attempt. Ten (53%) of 19 subjects treated with a serotonin reuptake inhibitor had much or very much improvement in BDD symptoms; in contrast, 0 of 8 trials with other psychotropic medications, 0 of 1 trial of cognitive-behavioral therapy, and 1 of 20 psychotherapy trials resulted in improvement. Twelve (36%) subjects received surgical, dermatological, or dental treatment, with a poor outcome in all cases. Conclusions BDD can cause significant morbidity in children and adolescents. These preliminary data suggest that serotonin reuptake inhibitors may be an effective treatment in this age group. J. Am. Acad. Child Adolesc, Psychiatry, 1999, 38(4):453–459.
On the geometrization of electrodynamics

This paper develops the conjecture that the electromagnetic interaction is the manifestation of the torsion Ωμ of spacetime. This conjecture is made feasible by the natural separation of the connection ωμv into “gravitational” and “electromagnetic” parts αμv and βμv, respectively, related to the metric and to the torsion. When αμv is neglected in front of βμv, the affine geodesics are shown to become the equations of motion of charged particles with Lorentz force, for an appropriate choice of Ωμ. Since βμv contains the factor q/m, neutral particles do not see the torsional part of the connection and behave as if Ωμ were zero, i.e., as in Einstein's theory of gravity (the same effect is obviously obtained for charged particles when βμv 《 αμv).
Improvement in coal liquefaction solvent quality by dewaxing

Abstract Recycle oils from the Integrated Two-Stage Liquefaction (ITSL), H-Coal and Solvent Refined Coal (SRC) processes were dewaxed by variants of commercial dewaxing processes—the ketone and the urea adduction techniques — yielding up to 47 wt % ‘wax’. Feed oils and product fractions were characterized by elemental analysis, 1 H n.m.r. and gas chromatography. The clean waxes were nearly pure mixtures of n -paraffins. The dewaxed oils were substantially better coal liquefaction solvents than the original (non-dewaxed) oils in batch liquefaction tests. For example, in one case, dewaxing improved the conversion of a bituminous coal to tetrahydrofuran-solubles under standard reaction conditions from 71 wt% (dafb) with the original oil to 87 wt % (dafb). These data provide a direct indication of the inimical effect of paraffinic components on solvent quality. The impact of solvent quality is particularly relevant to liquefaction processes in which thermal reactions proceed in a recycle solvent. In addition, the results indicate the technical feasibility of dewaxing coal liquefaction recycle oils by commercially available technology to improve solvent quality and to produce a useful by-product. Dewaxing could be applied in any liquefaction process that uses a deasphalted (preferably distillate) recycle stream.
The synthesis and structure of La5Pb3Z, Z N, O. Interstitial derivatives of a Cr5B3‐Type structure

Suitable proportions of La, La4Pb3 and La2O3 or LaN reacted in pressed pellets at 1050°–1250°C result in high yields of the title compounds. Single crystal X-ray studies of the oxide show it to be an isopointal, interstitial derivative of the Cr5B3 structure (I4/mcm, Z = 4, a = 8.6895(2) A, c = 14.540(1) A, R/Rw = 3.0/3.5%). Oxygen or nitrogen atoms are bound in (La2)4 tetrahedra within chains along (0, 1 /2, z). Negligible dimerization of the type characteristic of Cr5B3 is indicated by the Pb2Pb2 separation, 3.550(1) A. The structure is compared with other related examples. Synthese und Struktur von La5Pb3Z, Z N, O. Interstitielle Derivate einer Struktur vom Cr5B3-Typ Geeignete Mengen von La, La4Pb3 und La2O3 oder LaN werden, zu Tabletten geprest, bei 1050° bis 1250°C in hohen Ausbeuten zu den Titelverbindungen umgesetzt. Einkristall-Rontgenuntersuchungen an dem Oxid zeigen, das ein interstitielles Derivat der Cr5B3-Struktur (I4/mcm, Z = 4, a = 8,6895(2) A, c = 14,540(1) A, R/Rw = 3,0/3,5%) vorliegt. Sauerstoff- bzw. Stickstoffatome befinden sich in (La2)4-Tetraedern in den Ketten langs (0, 1 /2, z). Geringfugige Dimerisierung der Art, wie sie fur Cr5B3 charakteristisch ist, wird durch den Abstand Pb2Pb2 von 3,550(1) A angezeigt. Die Struktur wird mit anderen verwandten Beispielen verglichen.
IceCube: Status and First Results

IceCube is a cubic neutrino telescope under construction at the South Pole since the austral summer 2004/2005 with a total instrumented volume of the order of 1 km3. At the moment it is taking data with 40 deployed strings. The full detector is expected to be completed in 2011 with up to 80 strings holding 60 digital optical modules (DOMs) each. The progenitor detector AMANDA has been operating at the same site since 1997 and is still functioning as a means to enhance neutrino effective area at energies below 100 GeV. A summary of science results and status of the project is presented.
A note on special Kähler manifolds

We proved a conjecture of D. Freed that there are no non-trivial complete special Kaehler manifolds.
In situ Moessbauer study of redox processes in a composite hydroxide of iron and nickel

In situ Moessbauer spectra revealed changes in the electronic and structural properties of Fe sites brought about by redox processes attributed formally to Ni sites in a composite iron/nickel hydroxide. Measurements on the oxidized form, polarized in 1 M KOH at 0.5 V vs. Hg/HgO, revealed a singlet with an isomer shift of 0.22 mm/s vs. ..cap alpha..-Fe. After reduction and polarization at 0.0 V, a doublet with an isomer shift of 0.32 mm/s and a quadrupole splitting of 0.44 mm/s was observed. The spectral changes, which accompanied the formal oxidation of Ni sites at 0.5 V, indicated a partial transfer of electronic density away from trivalent Fe sites and structural rearrangements toward more symmetrical coordination about these sites. This highly oxidized iron species in the composite hydroxide may be involved in the electrocatalytic mechanism for oxygen evolution in alkaline media.
The Calabi-Yau conjectures for embedded surfaces

In this talk I will discuss the proof of the Calabi-Yau conjectures for embedded surfaces. This is joint work with Bill Minicozzi, [CM9]. The Calabi-Yau conjectures about surfaces date back to the 1960s. Much work has been done on them over the past four decades. In particular, examples of Jorge-Xavier from 1980 and Nadirashvili from 1996 showed that the immersed versions were false; we will show here that for embedded surfaces, i.e., injective immersions, they are in fact true. Their original form was given in 1965 in [Ca] where E. Calabi made the following two conjectures about minimal surfaces (see also S.S. Chern, page 212 of [Ch]): Conjecture 1. “Prove that a complete minimal hypersurface in R must be unbounded.” Calabi continued: “It is known that there are no compact minimal submanifolds of R (or of any simply connected complete Riemannian manifold with sectional curvature ≤ 0). A more ambitious conjecture is”: Conjecture 2. “A complete minimal hypersurface in R has an unbounded projection in every (n− 2)–dimensional flat subspace.”
Web-based 3D visualization in a digital library of mathematical functions

The National Institute of Standards and Technology (NIST) is developing a digital library of mathematical functions to replace the widely used National Bureau of Standards Handbook of Mathematical Functions [Abramowitz and Stegun 1964]. The NIST Digital Library of Mathematical Functions (DLMF) will provide a wide range of information about high level functions for scientific, technical and educational users in the mathematical and physical sciences. Clear, concise 3D visualizations that allow users to examine poles, zeros, branch cuts and other key features of complicated functions will be an integral part of the DLMF. Specially designed controls will enable users to move a cutting plane through the function surface, select the surface color mapping, choose the axis style, or transform the surface plot into a density plot. To date, Virtual Reality Modeling Language and Extensible 3D (VRML/X3D) standards have been used to implement these capabilities in more than one hundred 3D visualizations for the DLMF. We discuss the development of these visualizations, focusing on the design and implementation of the VRML code, and show several examples.
Direct Measurement of Chain Transfer during Controlled Radical Polymerization

The increasing deviation of Mw away from linearity vs conversion as U is increased is illustrated strikingly in Figure 1. Experiments 1 and 2, with the lowest U, are quite linear and come very close to their target mass. In contrast, in all other cases Mw has an initial negative second derivate, reaches a maximum value, and then decreases. In none of these cases does the final product ever reach its target mass, and in the case of highest U, the deviation is extreme. Trends in the evolution of [ ]w for these experiments were similar (data not shown). To analyze the data, consider initial molar concentrations of MONAMS [RT], monomer [m]0, and chain transfer agent [TT]. Usually [RT] is close to the starting concentration of alkoxyamine, [MONAMS]0. In the case of CRP there is an average fraction U of [RT] that is actively propagating at any instant. U is dependent on the equilibrium constant Keq between active and dormant species and, in excess, free SG1 that is added at the beginning of the reaction. When the initial mole ratio of free SG1 to MONAMS,
Issues of Manufactures Liberalization and Administered Protection in the Doha Round

This article focuses especially on the positions that the developing countries should take in their own interests on the issues of manufactures liberalization and administered protection. A series of recommendations are set forth with supporting argument, dealing with market access, adjustment, trade preferences, and other issues. Developing countries should participate actively and constructively in the negotiations to further their own interests. What is needed is leadership and cooperation, as for example with the Group of 20 and other coalitions, together with a willingness to listen and be flexible on the part of their developed country counterparts.
Cardinal Interpolation with Gaussian Kernels

In this paper, interpolation by scaled multi-integer translates of Gaussian kernels is studied. The main result establishes L p Sobolev error estimates and shows that the error is controlled by the L p multiplier norm of a Fourier multiplier closely related to the cardinal interpolant, and comparable to the Hilbert transform. Consequently, its multiplier norm is bounded independent of the grid spacing when 1<p<∞, and involves a logarithmic term when p=1 or ∞.
Systematic Finite-Sampling Inaccuracy in Free Energy Differences and Other Nonlinear Quantities

Systematic inaccuracy is inherent in any computational estimate of a non-linear average, such as the free energy difference ΔF between two states or systems, because of the availability of only a finite number of data values, N. In previous work, we outlined the fundamental statistical description of this “finite-sampling error.” We now give a more complete presentation of (i) rigorous general bounds on the free energy and other nonlinear averages, which generalize Jensen's inequality; (ii) asymptotic N→∞ expansions of the average behavior of the finite-sampling error in ΔF estimates; (iii) illustrative examples of large-N behavior, both in free-energy and other calculations; and (iv) the universal, large-N relation between the average finite-sampling error and the fluctuation in the error. An explicit role is played by Levy and Gaussian limiting distributions.
Some properties of the range of super-Brownian motion

We consider a super-Brownian motion X. Its canonical measures can be studied through the path-valued process called the Brownian snake. We obtain the limiting behavior of the volume of the ɛ-neighborhood for the range of the Brownian snake, and as a consequence we derive the analogous result for the range of super-Brownian motion and for the support of the integrated super-Brownian excursion. Then we prove the support of X t is capacity-equivalent to [0, 1]2 in ℝd, d≥ 3, and the range of X, as well as the support of the integrated super-Brownian excursion are capacity-equivalent to [0, 1]4 in ℝd, d≥ 5.
A Tank Heating Model for Aircraft Fuel Thermal Systems with Recirculation

Fuel thermal management has become an important consideration in the design and operation of modern high performance aircraft. In many cases, fuel is a primary heat sink for thermal loads associated with the cooling of the airframe as well as propulsion, electronic, actuator, and payload systems. It is now common for thermal systems to recirculate warm fuel to the tanks, resulting in a rise in temperature in the mission fuel mass. In this paper, a model is presented that integrates heat transfer during mission segments to determine the thermal endurance of an aircraft in terms of fuel tank temperature. The model is intended for early-phase trade studies to determine whether a proposed vehicle will be restricted in operational performance by tank temperature limits.
Pass-through in United States beef cattle prices: a test of Ricardian rent theory

Feeder cattle are fattened to become fed live cattle 6 months later, and the feeder cattle stock is fixed in the short-run. Efficiency in competitive markets suggests feeder cattle prices should fully reflect feed prices and information on future fed cattle prices. Employing a long time series (1979–2004) of feeder cattle futures, live cattle futures, and local corn prices, we test whether complete pass-through occurs. For fed cattle futures prices, we find about 93% of complete pass-through to present feeder cattle prices. The corresponding negative effect of a corn price increase is about 87% of complete pass-through. In contrast with imperfectly competitive agricultural land rental markets, the results support the hypothesis of Ricardian rent extraction by the scarce asset owner in feeder cattle markets.
1-bit matrix completion under exact low-rank constraint

We consider the problem of noisy 1-bit matrix completion under an exact rank constraint on the true underlying matrix M*. Instead of observing a subset of the noisy continuous-valued entries of a matrix M*, we observe a subset of noisy 1-bit (or binary) measurements generated according to a probabilistic model. We consider constrained maximum likelihood estimation of M*, under a constraint on the entry-wise infinity-norm of M* and an exact rank constraint. This is in contrast to previous work which has used convex relaxations for the rank. We provide an upper bound on the matrix estimation error under this model. Compared to the existing results, our bound has faster convergence rate with matrix dimensions when the fraction of revealed 1-bit observations is fixed, independent of the matrix dimensions. We also propose an iterative algorithm for solving our nonconvex optimization with a certificate of global optimality of the limiting point. This algorithm is based on low rank factorization of M*. We validate the method on synthetic and real data with improved performance over existing methods.
Proper orthogonal decomposition with updates for efficient control design in smart material systems

Proper orthogonal decomposition (POD) is a basis reduction technique that allows simulations of complicated systems to be calculated at faster speeds with minimal loss of accuracy. The reduced order basis is created from a set of system data called snapshots. The speed and information retention of POD make it an attractive method to implement reduced-order models of smart material systems. This can allow for the modeling of larger systems and the implementation of real time control, which may be impossible when using the full-order system. There are times when the dynamics of a system can change during a simulation, and the addition of more information to the set of snapshots would be beneficial. The implementation of control on a system is a time when adding new snapshots to the collection can increase the accuracy of the model. Using updates allows more flexibility when trying to balance the accuracy and the speed of the simulation. By updating the POD basis at specific times throughout the interval, we can increase the accuracy of the model and control by using a greater amount of the information given by the snapshots, while we can increase the speed of the simulation during times when using less information will still result in sufficient accuracy.
Uniform 1-cochains and genuine laminations

We construct a pair of transverse genuine laminations on an atoroidal 3-manifold admitting a transversely orientable uniform 1-cochain. The laminations are induced by the uniform 1-cochain and they are the straightening of the coarse laminations defined by Calegari, by using minimal surface techniques. Moreover, when we collapse these laminations, we get a topological pseudo-Anosov flow, as defined by Mosher.
Substrate and docking interactions in serine/threonine protein kinases.

Protein kinases have emerged as the largest family of signaling proteins in eukaryotic cells and are involved in every aspect of cellular regulation. There are over 500 protein kinases in the human genome.1,2 The vast majority are Ser/Thr protein kinases. The Ser/Thr protein kinases interact with diverse substrates ranging from enzymes, including other kinases, to transcription factors, receptors, and other regulatory proteins. Thus, mechanisms to assure specificity must be present. However, from emerging structural data it is becoming apparent that the ways in which protein kinases interact with their substrates local to the active site are relatively few. Instead, docking interactions, in pockets or grooves outside the active site of the kinase, are used to recognize substrates and other interacting proteins. Docking motifs in substrates bind in docking grooves within the kinase domain or adaptor protein. Docking interactions have been defined for CDKs (cyclin dependent kinases), MAPKs (mitogen activated protein kinases), and members of the AGC group (cAMP-dependent (PKA), cGMP-dependent, PKC), as well as several other kinases. Further, structural data is revealing that docking interactions regulate kinase activity by unanticipated allosteric mechanisms that probably promote pathway specificity. In this review, we outline the current structural data available on distinct Ser/Thr protein kinases. How kinases bind substrates at the active site is described, focusing on the P+1 pocket, which is remodeled in inactive forms of several protein kinases. Substrate docking interactions, outside the active site, observed in MAP kinases, CDKs and AGC kinases will be described. How specificity among these different families of kinases is achieved from the organization of the binding site and other factors will be discussed. Further, available data suggesting that docking interactions control kinase activity allosterically will be reviewed. Recent reviews of topics under discussion,3–10 and related topics11–17 are available.
Entropy and supersymmetry of D-dimensional extremal electric black holes versus string states

Abstract Following the work of Sen, we consider the correspondence between extremal black holes and string states in the context of the entropy. We obtain and study properties of electrically charged black hole backgrounds of tree level heterotic string theory compactified on a p-dimensional torus, for D = (10 − p) = 4,…,9. We study in particular a one-parameter extremal class of these black holes, the members of which are shown to be supersymmetric. We find that the entropy of such an extremal black hole, when calculated at the stringy stretched horizon, scales in such a way that it can be identified with the entropy of the elementary string state with the corresponding quantum numbers.
Nearly time-optimal feedback control of a magnetically levitated photolithography positioning system

This paper focuses on the development of an approximate time- optimal feedback strategy for conducting rest-to-rest maneuvers of a magnetically levitated table. Classical switching curves are modified to account for the complexities of magnetic actuation as well as the coupling of the rigid body modes through the control. A smooth blend of time-optimal and proportional-derivative controls is realized near the destination point to correct for inaccuracies produced by the approximate time-optimal strategy. Detailed computer simulations of the system indicate that this hybrid control strategy provides a significant reduction in settling time as compared to proportional-derivative control alone.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nonequilibrium Statistical Mechanics of Self-propelled Hard Rods

Using tools of nonequilibrium mechanics, we study a model of self-propelled hard rods on a substrate in two dimensions to quantify the interplay of self-propulsion and excluded-volume effects. We derive a Smoluchowski equation for the configurational probability density of self-propelled rods that contains several modifications as compared to the familiar Smoluchowski equation for thermal rods. As a side-product of our work, we also present a purely dynamical derivation of the Onsager form of the mean-field excluded-volume interaction among thermal hard rods.
Bananas, Direct Effect and Compliance

The complex bananas litigation could serve as a course in international economic law, as it raises a rich set of issues that arise in a highly contentious circumstance and present difficult issues of legal policy. At the core of this litigation is the question of compliance with law. This comment briefly and selectively reviews the legal manoeuvring in the European Community, the GATT, the World Trade Organization and the US, as a basis for an analysis of the problem of compliance in the GATT/WTO system, and the relation of direct effect to compliance. This comment argues that hard law is not necessarily good law, and that strengthened implementation, including possible direct effect, is not necessarily desirable. This seems obvious once we recognize that, putting aside for a moment transaction costs and strategic costs, states generally have the level of compliance that they want. The correct role for scholars and for lawyers involved with these issues is to help political decision-makers to identify circumstances in which, due to such problems, states have not achieved the desired level of compliance.
Contamination Effects on the Geostationary Operational Environmental Satellite Instrument Thermal Control System

The instrument thermal control system of the Geostationary Operational Environmental Satellite may have been affected by specie c contamination problems that arose because of the unique conditions and requirements of the spacecraft mission. This paper addresses some specie c contamination effects from the coatings used in the instrument cavities. Contamination control actions that were implemented during ground processing to ensure limited impact on the on-orbit temperature control are described. The selection of thermal coatings is an integral part of the overall spacecraft design. Molecular contamination accretion on thermal coatings may alter the design properties of the surface coatings. In an effort to quantify the molecular contamination effects from material outgassing, an assessment was conducted to address the concerns inside the instrument cavities. The study results prompted an extensive prelaunch vacuum bakeout effort and an on-orbit solar radiation avoidance exercise. In addition, the thermal performance of the instrument radiant coolers could have been detrimentally affected by scattered solar radiation from particulate contamination. To mitigate the impact of the particulate contamination the radiant cooler surfaces were cleaned to an established criteria prior to launch.
Euro adoption and Maastricht criteria: Rules or discretion?

Abstract In connection with the prospective euro adoption by the new EU members, the issue of how strictly to enforce the Maastricht criteria for joining the European Economic and Monetary Union (EMU) has been discussed for some time. Arguments have been made in favor of a more flexible interpretation of some Maastricht criteria to take into account the specific conditions of the new member states (NMS). This paper makes a case for a more flexible interpretation of the Maastricht inflation criterion and proposes a different specification. Further, it examines the compatibility of inflation and exchange rate Maastricht targets and argues that under the specific circumstances of euro adoption, and taking into account the way these targets are defined, meeting both of them during a limited period of time should not pose a problem. Finally, the paper argues that both for short-term cyclical and long-term sustainability reasons, the NMS may aim at somewhat more ambitious fiscal targets before euro adoption than required by the Maastricht fiscal criteria.
Suppression of multi-gluon fluctuations in jets at a linear collider

Abstract It was shown that at typical energies and luminosities of an e + e − linear collider one can observe a significant suppression of fluctuations of the number of gluons in small angular regions. This property of jets is expected in e + e − annihilation as well as in any collision producing high energy quarks which give rise to the QCD gluon cascade. The reduction of multiplicity fluctuations was obtained from perturbative QCD using bunching parameters and then cross checked with a Monte Carlo simulation. The parton-level Monte Carlo simulation confirms the prediction, while the hadron level illustrates that the effect survives the hadronization process.
Toward equilibration in the early stages after a high energy heavy ion collision

Abstract The early stages in the evolution of the gluons produced in the central region of a head-on high-energy heavy ion collision are studied. An equation is given for the rate of change of transverse momentum into longitudinal momentum where the longitudinal direction is along the collision axis. We are able to follow the system up to the time where equilibration seems to be setting in, but we are unable to actually follow the system as it reaches equilibrium.
Mu Opioid Receptor Antagonists: Recent Developments

For thousands of years mu opioid agonists such as morphine have been utilized for their analgesic properties. Today, morphine and related compounds are still used as a first line therapy in the treatment of moderate to severe pain. However, despite the clear benefits of mu agonists in pain management, severe side effects such as dependence and respiratory depression are associated with use of these drugs. To date, there are only two approved mu opioid antagonists for use in the treatment of these adverse effects, that is, naloxone and naltrexone. However, many other clinical and therapeutic areas have been linked to mu opioid receptor antagonism. These include treatment of opioid induced pruritis of the skin, obesity, and Parkinson-induced tardive dyskinesia. Currently there are two compounds, N-methylnaltrexone and alvimopan, under FDA review as possible treatments for opioid induced bowel dysfunction and postoperative ileus. These compounds are of special interest as they are peripherally restricted. This attribute enables treatment of peripheral side effects induced by opioid agonists without reversal of the centrally mediated analgesia of the agonist. In this article we discuss the structural classes of mu opioid antagonists, their potential clinical applications, and review the relevant patents of the last ten years.
Continuous Renal Replacement Therapies in the Acute Renal Failure Setting: Current Concepts

Several new methods of renal replacement therapy are now available for the treatment of acute renal failure in the intensive care unit (ICU) setting. Continuous dialysis techniques have evolved over the last decade and are now increasingly used in the ICU. This review provides a framework for the evaluation of these therapies and discusses the emerging indications for their use.
CRITICAL PHENOMENA AT THE ANTIFERROMAGNETIC TRANSITION IN MNO

The specific heat of a polycrystalline sample of MnO was measured from $T\ensuremath{\approx}1\mathrm{K}$ to $T\ensuremath{\approx}400\mathrm{K}$ using two different experimental apparatuses at zero applied pressure. Features revealed by the data include a hyperfine contribution due to the Mn nuclei, a ${T}^{2}$ temperature dependence at low temperatures due to the type-II antiferromagnetic magnon contribution, and a sharp but well defined antiferromagnetic transition ${(T}_{N}=117.7095\mathrm{K})$ that is clearly second order in nature. The critical exponent \ensuremath{\alpha} deduced from the transition is consistent with a two-dimensional Ising model. The specific heat of MnO is also compared with recent results on the type-A antiferromagnet ${\mathrm{LaMnO}}_{3}.$
Absolutely representing systems, uniform smoothness and type

An absolutely representing system (ARS) in a Banach space X is a set D ⊂ X such that every vector x in X admits a representation by an absolutely convergent series x = Σ i a i x i with (a i ) ⊂ R and (x i ) ⊂ D. We investigate some general properties of absolutely representing systems. In particular, absolutely representing systems in uniformly smooth and in B-convex Banach spaces are characterized via ∊-nets of the unit balls. Every absolutely representing system in a B-convex Banach space is quick, i.e., in the representation above one can achieve ∥a i x i ∥ 0 and q ∊ (0,1).
Charge ordering in half-doped manganites: Weak charge disproportion and leading mechanisms

The apparent contradiction between the recently observed weak charge disproportion and the traditional Mn3+/Mn4+ picture of the charge-orbital orders in half-doped manganites is resolved by a novel Wannier states analysis of the LDA+U electronic structure. Strong electron itinerancy in this charge-transfer system significantly delocalizes the occupied low-energy Mn3+ Wannier states such that charge leaks into the Mn4+-sites. Furthermore, the leading mechanisms of the charge order are quantified via our first-principles derivation of the low-energy effective Hamiltonian. The electron-electron interaction is found to play a role as important as the electron-lattice interaction.