cssi/SciSciGPT-SciSciNet huggingface dataset:
Diffracted Wave Fields Expressible by Plane-Wave Expansions Containing only Homogeneous Waves

The angular-spectrum representation of wave fields is shown to yield scalar Helmholtz-equation solutions (in a half-space) that tend in the L2 limit of the mean to prescribed boundary values on an infinite plane boundary for all square-integrable boundary values. This result is employed to obtain several important properties of source-free wave fields, i.e., wave fields (satisfying square-integrable boundary values) that contain only homogeneous plane waves in their angular-spectrum representations: (1) the function describing a source-free wave field can be extended into the region behind the plane boundary to give a bounded continuous solution of the scalar Helmholtz equation in all space; (2) the function describing a wave field can be extended to the whole space of three complex variables as an entire function satisfying a certain inequality if, and only if, the wave field is source free; (3) the two-dimensional autocorrelation function of the wave field on planes parallel to the boundary plane is independent of the distance of the plane from the boundary if, and only if, the field is source free; and (4) a boundary value exists that produces a three-dimensional, pseudoscopic, real image of a wave field if, and only if, the wave field is source free. A series-mode expansion for source-free fields in terms of the boundary value is derived and is shown to be absolutely and uniformly convergent. The series is transformed into a two-dimensional Taylor series (with coefficients determined in terms of the boundary value) and another series that displays explicitly the contribution to the wave field due to each partial derivative of boundary value. The series are valid representations of wave fields in a broad class that is the natural extension of the source-free class of fields when the restriction that the boundary value be square integrable is removed. The series are used to derive two angular-spectrum representations for wave fields in the extended class and to discuss the properties of those wave fields.
On three-dimensional mirror symmetry

Mirror Symmetry for a large class of three dimensional $ \mathcal{N} = 4 $ supersymmetric gauge theories has a natural explanation in terms of M-theory compactified on a product of ALE spaces. A pair of such mirror duals can be described as two different deformations of the eleven-dimensional supergravity background $ \mathcal{M} = {\mathbb{R}^{2,1}} \times {\text{AL}}{{\text{E}}_1} \times {\text{AL}}{{\text{E}}_2} $ , to which they flow in the deep IR. Using the A − D − E classification of ALE spaces, we present a neat way to catalogue dual quiver gauge theories that arise in this fashion. In addition to the well-known examples studied in [1, 2], this procedure leads to new sets of dual theories. For a certain subset of dual theories which arise from the aforementioned M-theory background with an A-type ALE1 and a D-type ALE2, we verify the duality explicitly by a computation of partition functions of the theories on S 3, using localization techniques. We derive the relevant mirror map and discuss its agreement with predictions from the Type IIB brane construction for these theories.
A comparison of two- and three-dimensional imaging

Three dimensional visual recognition and measurement are important in many machine vision applications. In some cases, a stationary camera base is used and a three-dimensional model will permit the measurement of depth information from a scene. One important special case is stereo vision for human visualization or measurements. In cases in which the camera base is also in motion, a seven dimensional model may be used. Such is the case for navigation of an autonomous mobile robot. The purpose of this paper is to provide a computational view and introduction of three methods to three-dimensional vision. Models are presented for each situation and example computations and images are presented. The significance of this work is that it shows that various methods based on three-dimensional vision may be used for solving two and three dimensional vision problems. We hope this work will be slightly iconoclastic but also inspirational by encouraging further research in optical engineering.
Transport of nutrients and hormones through the blood-brain barrier

An understanding of the mechanisms of transport of circulating nutrients and hormones through the brain capillary wall, i. e., the blood-brain barrier, is important because the availability in brain of these substances influences a number of cerebral metabolic pathways. For example, the utilization by brain of glucose, ketone bodies and branched chain amino acids or the production of monoamines, acetylcholine, carnosine, and nucleosides may under certain conditions be influenced by BBB transport of circulating precursor nutrients. Steroid and thyroid hormones readily traverse the BBB via lipid-mediation and carrier-mediation, respectively. Although the steroid and thyroid hormones are tightly bound by plasma proteins, protein-bound hormone, not the free (dialyzable) moiety, is the major plasma fraction transported through the BBB. With regard to circulating peptides, the available evidence indicates peptides rapidly distribute into brain interstitial space of the circumventricular organs of brain, i. e., about six small regions around the ventricles which lack a BBB. Conversely, the absence of peptide carriers in the BBB prevents the rapid distribution of peptides into the vast majority of brain interstitial or synaptic spaces. However, recent studies indicate that some peptides, e. g., insulin, may bind specific receptors on the blood side of the BBB and thereby transmit messages to cells on the brain side of the BBB, without the peptide traversing the capillary wall.
Supersymmetric model of quasi-degenerate neutrinos

Abstract We present a supersymmetric model of fermion masses, based on a non-Abelian family symmetry and the Froggatt-Nielsen mechanism, that can account for the solar and atmospheric neutrino problems via quasi-degenerate neutrinos. The model predicts that the ratio of neutrino mass squared splittings Δm 2 12 / Δm 2 23 is of order m s 2 / m b 2 , and the angles θ 12 ∼ m d / m s and θ 23 ∼1, which are of the desired orders of magnitude. We discuss the implications of the flavor structure of the neutrino sector on superparticle masses and mixing angles.
Rethinking Fiscal Policy

The use of fiscal policy as a stabilization device has all but vanished, more or less explicitly in Europe and de facto in the United States. The practical consequences have not been entirely satisfactory, in either place. So it is important and timely that the Oxford Review is devoting a special issue to the macroeconomics of fiscal policy. In this paper I want to discuss two underlying questions about the eclipse of fiscal policy. Why did this happen and was it a good ideaq And if it was not a good idea, then what followsq Copyright 2005, Oxford University Press.
Asymmetric allylboration of acyl imines catalyzed by chiral diols.

Chiral BINOL-derived diols catalyze the enantioselective asymmetric allylboration of acyl imines. The reaction requires 15 mol % (S)-3,3‘-Ph2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (75−94%) and high enantiomeric ratios (95:5−99.5:0.5) for aromatic and aliphatic imines. High diastereoselectivities (diastereomeric ratio > 98:2) and enantioselectivities (enantiomeric ratio > 98:2) are obtained in the reactions of acyl imines with crotyldiisopropoxyboranes. This asymmetric transformation is directly applied to the synthesis of Maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry studies indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding.
Carrots, Sticks, and Promises: A Conceptual Framework for the Management of Public Health and Social Issue Behaviors

of these deaths are "premature" and attributable to lifestyle and environmental factors (UC Berkley Wellness Letter 1997). Advances in biomedical sciences, mass immunization, and sanitation have resulted in a decrease in the incidence of infectious diseases (Matarazzo 1984), so that the health status of the population in economically developed countries now has less to do with acute illness than with lifestyle issues such as excessive drinking, unhealthy diet, or the use of tobacco products (Walsh et al.1993). Influencing lifestyle can do more to increase the health of the population and lower the cost of health care than can treatment of illness. In this article, a conceptual framework is proposed for the management of public health and social issue behaviors. The article relies on education, marketing, and law as its three primary classes of strategic tools. These tools will be considered with respect to specific targets and specific public health or social issues for which the targets may or may not have any motivation, opportunity, and/or ability to cooperate but that nevertheless have been selected for management (e.g. keeping preteen girls from beginning to smoke). The tools are considered with respect to targets who are prone, resistant, or unable to comply with the manager's goals. The relative appropriateness of the use of various Michael L. Rothschild
On Representation of Integers by Binary Quadratic Forms

Given a negative D > −(logX)log2−δ , we give a new upper bound on the number of square free integers X which are represented by some but not all forms of the genus of a primitive positive definite binary quadratic form of discriminant D. We also give an analogous upper bound for square free integers of the form q+a X where q is prime and a ∈ Z is fixed. Combined with the 1/2-dimensional sieve of Iwaniec, this yields a lower bound on the number of such integers q+a X represented by a binary quadratic form of discriminant D, where D is allowed to grow with X as above. An immediate consequence of this, coming from recent work of the authors in [3], is a lower bound on the number of primes which come up as curvatures in a given primitive integer Apollonian circle packing.
Feasible Flight Paths for Cooperative Generation of a Phantom Radar Track

Electronic attack on air defense radar networks by electronic combat air vehicles (ECAVs) is considered. The scope of the attack is the creation of a coherent phantom track in two dimensions-range and azimuth-by a team of cooperatively controlled ECAVs, each capable of intercepting and sending delayed returns of radar pulses. It is first shown that assuming constant speeds for the phantom track and ECAVs severely restricts where the ECAVs can fly. Accordingly, general dynamic and spatial limitations on an ECAV are developed given ranges on the ECAV speed, phantom track speed, and ECAV region of antenna operation; six dynamical systems are also constructed for simulating feasible ECAV trajectories to test the analytical limitations. This theory is applied to construct detailed flyable ranges for an ECAV generating a straight and a circular phantom track, separately. Based on distilling the results, generalized bounds are presented-independent of the phantom track type¯for the initial conditions and time-dependent flyable ranges of a team of ECAVs. These bounds are then used with coordination functions to informally solve an illustrative decentralized cooperative control problem in which the ECAV team seeks an optimal straight phantom track to minimize their bounds-dependent aggregate cost.
The Dispersion of ETF Betas on Financial Websites

This article documents significant dispersion in the beta estimates of exchange-traded funds as available on some leading financial websites. To the best of the authors’ knowledge, this is the first systematic study of the dispersion of betas as seen on major finance websites. Almost 40 million visitors access these websites per month. The authors find that leading sites such as Yahoo! Finance, MSNMoney, Morningstar, and Google Finance display betas that significantly (but not intentionally) misrepresent actual levels of systematic risk. These errors could impact the portfolio design of an investor, leading to unintended outcomes. Additionally, the authors identify the primary reason for the significant variance in beta estimates. The explanation is surprising and not rooted in the traditionally discussed differences that are attributed to interval-window length mismatch or varying frequency of security returns. An implication of the findings is that there is no substitute for verification and cross-validation of financial information, even if it is supposedly coming from well-established sources or so-called “black boxes.”
The Future of EMC Instrumentation

The paper reviews the broad field of EMC Instrumentation as it has evolved today, and attempts to outline the equipment which will be required to meet the fast growing needs of present and future systems. The functional requirements are reviewed, and key performance characteristics outlined in terms of measurement instrument parameters. In some cases, the performance characteristics require very significant improvement. This would be considered normal were it not for the simultaneous great increase required in degree of automation and operating speed, or data rate. The resulting dichotomy is unusually sharp and requires careful planning. Traditionally, EMC phenomena have been approached on a frequency domain basis, including transient effects. This was valid since almost all systems operated on a frequency domain basis, and will be valid for most systems for a considerable time to come. Increasing use of digital communications and control systems has shown the frequency domain approach to be inadequate for the treatment of such systems. It appears that a more efficient direct time domain approach will be required for an increasing number of systems. This will call for establishment of new standards, specifications, measurement equipment, and techniques.
Where Are All the Fallback Disks? Constraints on Propeller Systems

Fallback disks are expected to form around newborn neutron stars following a supernova explosion. In almost all cases, the disk will pass through a propeller stage. If the neutron star is spinning rapidly (initial period ~10 ms) and has an ordinary magnetic moment (~1030 G cm3), the rotational power transferred to the disk by the magnetic field of the neutron star will exceed the Eddington limit by many orders of magnitude, and the disk will be rapidly disrupted. Fallback disks can thus survive only around slow-born neutron stars and around black holes, assuming the latter do not torque their surrounding disks as strongly as do neutron stars. This might explain the apparent rarity of fallback disks around young compact objects.
Radial Flow of Dust Particles in Accretion Disks

We study the radial migration of dust particles in accreting protostellar disks analogous to the primordial solar nebula. Our main objective is to determine the retention efficiency of dust particles, which are the building blocks of the much larger planetesimals. This study takes account of the two-dimensional (radial and normal) structure of the disk gas, including the effects of the variation in the gas velocity as a function of distance from the midplane. It is shown that the dust component of disks accretes slower than the gas component. At high altitude from the disk midplane (higher than a few disk scale heights), the gas rotates faster than the particles because of the inward pressure gradient force, and its drag force causes particles to move outward in the radial direction. Viscous torque induces the gas within a scale height from the disk midplane to flow outward, carrying small (size 100 μm at 10 AU) particles with it. Only particles at intermediate altitude or with sufficiently large sizes (1 mm at 10 AU) move inward. When the particles' radial velocities are averaged over the entire vertical direction, the particles have a net inward flux. The magnitude of their radial motion depends on their distance from the central star. At large distances, particles migrate inward with a velocity much faster than the gas accretion velocity. However, their inward velocity is reduced below that of the gas in the inner regions of the disk. The rate of velocity decrease is a function of the particles' size. While larger particles retain fast accretion velocity until they approach closer to the star, 10 μm particles have slower velocity than the gas in the majority of the disk (r 100 AU). This differential migration of particles causes size fractionation. Dust disks composed mostly of small particles (size 10 μm) accrete slower than gas disks, resulting in an increase in the dust-gas ratio during the gas accretion phase. If the gas disk has a steep radial density gradient or if dust particles sediment effectively to the disk midplane, the net vertically averaged flux of particles can be outward. In this case, the accretion of the dust component is prevented, leading to the formation of residual dust disks after their gas component is severely depleted.
Narcissistic CEOs and executive compensation

Abstract Narcissism is characterized by traits such as dominance, self-confidence, a sense of entitlement, grandiosity, and low empathy. There is growing evidence that individuals with these characteristics often emerge as leaders, and that narcissistic CEOs may make more impulsive and risky decisions. We suggest that these tendencies may also affect how compensation is allocated among top management teams. Using employee ratings of personality for the CEOs of 32 prominent high-technology firms, we investigate whether more narcissistic CEOs have compensation packages that are systematically different from their less narcissistic peers, and specifically whether these differences increase the longer the CEO stays with the firm. As predicted, we find that more narcissistic CEOs who have been with their firm longer receive more total direct compensation (salary, bonus, and stock options), have more money in their total shareholdings, and have larger discrepancies between their own (higher) compensation and the other members of their team.
Readability of websites containing information about prostate cancer treatment options

Purpose: Approximately 90 million American adults have literacy skills that test below a high school reading level. Websites written above this level can pose a challenge for those seeking online information about prostate cancer treatment options. In this study we determine the readability of selected websites using a systematic search process and validated readability formulas.Materials and Methods: We identified the 3 most popular keywords from 513 terms related to prostate cancer treatment options. We then systematically collected 270 websites from the top 3 search engines, and excluded from study those that were nonEnglish, not primarily text, irrelevant and/or duplicated. We used the Flesch-Kincaid grade level and Flesch Reading Ease to determine scores for each site.Results: A total of 62 unique websites were analyzed. Median Flesch-Kincaid grade level was 12.0 (range 8.0 to 12.0) and median Flesch Reading Ease score was 38.1 (range 0.0 to 65.5). Only 3 sites (4.8%) were written below a high school...
AIR WARS: REGULATION AND DEREGULATION IN THE INTERNATIONAL AIR PASSENGER MARKET

International civil aviation is governed by a cartel that dissipates its monopoly profits in surplus capacity. Based on the 1946 Bermuda agreement and the International Air Transport Association, the cartel imposes heavy costs on U.S. consumers and air travellers in general. The Carter administration attempted to make international aviation more competitive, but this progress was substantially reversed under Reagan. A new policy should be based on treating air travel the same as any other commodity and therefore subject to U.S. antidumping and antitrust laws. The goal of the policy should be to shift the cost of maintaining inefficient national flag carriers from the international community back on to the taxpayers of those countries.
X-Ray Reconstruction of the Spinal Cord, Using Bone Suppression

In this paper, a new method is developed for obtaining an X-ray reconstruction of the soft tissue detail of the spinal canal. By removing the dominant effects of the bony vertebral body within the projection actual clinical data, higher quality images of the residual soft tissues components can be reconstructed. The intent is a direct visualization of the spinal cord without the need for water-soluble contrast (e.g., Metrizamide) to be installed through a lumbar or cervical puncture. This technique for bone suppression also has potential for improving visualization of the interior of the mastoid cavities in the head.
COMPLETELY METRISABLE GROUPS ACTING ON TREES

We consider actions of completely metrisable groups on simplicial trees in the context of the Bass-Serre theory. Our main result characterises continuity of the amplitude function corresponding to a given action. Under fairly mild conditions on a completely metrisable group G, namely, that the set of elements generating a non-discrete or finite subgroup is somewhere dense, we show that in any decomposition as a free product with amalgamation, G = A ! C B, the amalgamated groups A, B and C are open in G. §1. Introduction. WhileKlein inhisErlangenprogrammeinsisted thatgeometric structures should be understood through their symmetry groups, one of the main tenets of geometric group theory is that abstract groups should be understood by via their actions on geometric structures. A particular instance of this is the Bass-Serre theory of actions on trees (20), which gives a complete understanding of free products with amalgamation and HNN extensions of groups. The present paper specialises the Bass-Serre theory to common topological groups and can be seen as an attempt to provide a coherent approach to various phenomena from the literature indicating a certain rigidity of completely metrisable groups with respect to freeconstructionsandactionson trees. Wearespecifically aiming togaina better understanding of the following result.
Multicatalytic Synthesis of α-Pyrrolidinyl Ketones via a Tandem Palladium(II)/Indium(III)-Catalyzed Aminochlorocarbonylation/Friedel−Crafts Acylation Reaction

An oxidative carbonylation reaction that generates acid chloride functionality has been developed. Furthermore, this aminochlorocarbonylation reaction has been merged with a catalytic Friedel−Crafts acylation to produce a highly efficient tandem multicatalytic synthesis of pyrrolidinyl ketones. Significant variation of the aromatic nucleophile and substrate are shown. Two examples of incorporation of this method in triple-catalytic sequences are also demonstrated.
Should Policy-Based Lending Still Involve Conditionality?

Traditional conditionality in policy-based lending is often criticized as being ineffective, intrusive, and corrosive. Disillusionment has led to replace ex ante conditionality with ex post conditionality and to focus on ownership, selectivity, and partnership. This article reviews experiences with conditionality in the World Bank policy-based lending and explores the benefits and drawbacks of various approaches. It argues that conditionality should play a central role in policy-based lending-but cannot substitute for country ownership and good policies. Moreover an exclusive focus on conditionality based on ex ante commitments or ex post results may not be practical or useful for the Bank policy-based lending. Thus a key recommendation in to use conditionality selectively, tailred to country circumstances. Indeed, an eclectic mix of traditional and new approaches is already being used with programmatic policy-based lending offering a particularly promising way to reconcile the debate between the traditional ex ante approach and the aspirations of a results-based approach to conditionality.
Vacuum Arc Ion Sources

The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. The beam parameters can be attractive, and the source has provided a valuable addition to the spectrum of ion sources available to the experimenter. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with beam current up to several amperes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle of order 1%, and operation of a dc embodiment has been demonstrated. Here the source fundamentals and operation are reviewed, the source and beam characteristics summarized, and some applications examined.
Constraining Evolution in the Halo Model Using Galaxy Redshift Surveys

We use the latest observations from the 2dF Galaxy Redshift Survey to fit the conditional luminosity function (CLF) formulation of the halo model for galaxies at z = 0. This fit is then used to test the extent of evolution in the halo occupation distribution to z = 0.8, by comparing the predicted clustering from this CLF to preliminary results from the DEEP2 Redshift Survey. We show that the current observations from the DEEP2 Redshift Survey are remarkably consistent with no evolution in the CLF from z = 0 to 0.8. This result is surprising, in that it suggests that there has been very little change in the way galaxies occupy their host dark matter halos over half the age of the universe. We discuss in detail the observational constraints we have adopted and also the various selection effects in each survey and how these affect the galaxy populations encountered in each survey.
Fabrication of silicon on lattice-engineered substrate (SOLES) as a platform for monolithic integration of CMOS and optoelectronic devices

Abstract We report the fabrication of a novel substrate platform for the monolithic integration of Si-based CMOS and GaAs-based optoelectronic devices. This platform, which we refer to as silicon on lattice-engineered substrate (SOLES), consists of a compositionally graded Si 1− x Ge x buffer buried underneath an SOI structure, all fabricated on a Si substrate. The Si 1− x Ge x graded buffer was grown by UHVCVD and was capped with a Ge-rich alloy that is closely lattice-matched to GaAs (0.96 x Ge 6 cm −2 . While these Si 1− x Ge x graded buffers have been proven by previous studies to be an effective platform for fabrication of GaAs-based LEDs, lasers, and solar cells on Si substrates, the integration of both Si- and GaAs-based devices on a single chip using this technique is hampered by the large thickness (∼10 μm) of the Si 1− x Ge x graded buffer. SOLES eliminates this drawback by the addition of the SOI structure on top of the Ge-rich cap. This approach provides for a Si device layer in close proximity to the GaAs-based device layer, thereby simplifying the monolithic integration of Si- and GaAs-based devices with this platform. Fabrication consists of layer transfer of Si to an oxide-coated graded buffer using oxide–oxide wafer bonding followed by hydrogen-induced layer exfoliation of the Si layer from its donor wafer. Our results show this layer transfer occurs reliably across the entire wafer, making it amenable to commercial application.
A Portfolio Performance Index

Fund managers may sensibly be averse to earning a time-averaged portfolio return that is less than the average return of some designated benchmark. When a portfolio is expected to earn a higher average return than the benchmark return, the probability that it will not approaches zero asymptotically at a computable exponential decay rate. The probability decay rate is thus proposed here as a new portfolio “performance index.” In the widely analyzed special case in which returns are normally distributed, the new performance-index-maximizing portfolio is the same as the popular Sharpe-ratio-maximizing portfolio. The results of the two approaches generally differ, however, because of nonnormal levels of skewness and/or kurtosis in the portfolio attributable to large asymmetrical economic shocks or investments in options and other derivative securities. An illustrative example will show that the new index is easy to implement and, consistent with empirical evidence on portfolio choice, favors investments with ...
Doping profiles for indium antimonide magnetoresistors

Abstract Indium antimonide is of interest for magnetoresistors in position- and speed-sensing applications. These sensors are fabricated as thin-film elements in order to increase the device impedance. The InSb is normally doped n-type to stabilize the electron density and hence the impedance with respect to temperature changes. This involves tradeoffs, since ionized donors also scatter electrons, reducing their mobility and hence reducing the device sensitivity to a magnetic field. Therefore, optimizing the sensitivity of these devices involves optimizing the doping of the InSb. This optimization involves three steps. The InSb is undoped for the first 10–20% of the film, forming a buffer from the latticemismatched substrate. The middle, active, layer of the film has a doping gradient. Finally, a thin contact layer is more heavily doped to reduce parasitic contact resistance.
A New Criterion for Predicting Rolling-Element Fatigue Lives of Through-Hardened Steels

A carbide factor was derived based upon a statistical analysis which related rolling-element fatigue life to the total number of residual carbide particles per unit area, median residual carbide size, and percent residual carbide area. An equation was experimentally determined which predicts material hardness as a function of temperature. The limiting temperatures of all of the materials studied were dependent on initial room temperature hardness and tempering temperature. An equation was derived combining the effects of material hardness, carbide factor, and bearing temperature to predict rolling-element bearing life.
Global existence for the einstein vacuum equations in wave coordinates

We prove global stability of Minkowski space for the Einstein vacuum equations in harmonic (wave) coordinate gauge for the set of restricted data coinciding with the Schwarzschild solution in the neighborhood of space-like infinity. The result contradicts previous beliefs that wave coordinates are “unstable in the large” and provides an alternative approach to the stability problem originally solved ( for unrestricted data, in a different gauge and with a precise description of the asymptotic behavior at null infinity) by D. Christodoulou and S. Klainerman. Using the wave coordinate gauge we recast the Einstein equations as a system of quasilinear wave equations and, in absence of the classical null condition, establish a small data global existence result. In our previous work we introduced the notion of a weak null condition and showed that the Einstein equations in harmonic coordinates satisfy this condition.The result of this paper relies on this observation and combines it with the vector field method based on the symmetries of the standard Minkowski space. In a forthcoming paper we will address the question of stability of Minkowski space for the Einstein vacuum equations in wave coordinates for all “small” asymptotically flat data and the case of the Einstein equations coupled to a scalar field.
Far-infrared extinction mapping of infrared dark clouds

Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e., dense clumps and cores in giant molecular clouds that are on the verge of gravitational instability. Such structures have been studied by their extinction of near-infrared and, more recently, mid-infrared (MIR) background light. It has been somewhat more of a surprise to find that there are regions that appear as dark shadows at far-infrared (FIR) wavelengths as long as ~100 ?m! Here we develop analysis methods of FIR images from Spitzer-MIPS and Herschel-PACS that allow quantitative measurements of cloud mass surface density, ?. The method builds on that developed for MIR extinction mapping by Butler & Tan, in particular involving a search for independently saturated, i.e., very opaque, regions that allow measurement of the foreground intensity. We focus on three massive starless core/clumps in the Infrared Dark Cloud (IRDC) G028.37+00.07, deriving mass surface density maps from 3.5 to 70 ?m. A by-product of this analysis is the measurement of the spectral energy distribution of the diffuse foreground emission. The lower opacity at 70 ?m allows us to probe to higher ? values, up to ~1 g cm?2 in the densest parts of the core/clumps. Comparison of the ? maps at different wavelengths constrains the shape of the MIR-FIR dust opacity law in IRDCs. We find that it is most consistent with the thick ice mantle models of Ossenkopf & Henning. There is tentative evidence for grain ice mantle growth as one goes from lower to higher ??regions.
Inclusion of women academics into American universities: Analysis of women status reports

American research universities play an important role in the ongoing campaign to improve the status of women academics. During the last four decades, the practice of producing ‘status of women’ reports has been widely developed as part of the policy and management repertoire to understand the barriers women academics may face in their institutions. In this study, we attempt to unfold the institutional determinants of producing such reports. The findings suggest that the most important determinant is the existence of a permanent and institutionally sanctioned commission on women at the university level. This type of institutional commitment to matters of women academics proves far more important than the presence of policy entrepreneurs or programme support such as the NSF ADVANCE initiative. The primary policy implication is that universities should invest in and maintain formal institutional structures that focus on the particular needs of women academics.
Optimal Routing with Mutual Information Accumulation in Wireless Networks

We investigate optimal routing and scheduling strategies for multi-hop wireless networks with rateless codes. Rateless codes allow each node of the network to accumulate mutual information with every packet transmission. This enables a significant performance gain over conventional shortest path routing. Further, it also outperforms cooperative communication techniques that are based on energy accumulation. However, it creates complex and combinatorial networking decisions concerning which nodes participate in transmission, and which decode ordering to use. We formulate three problems of interest in this setting: (i) minimum delay routing, (ii) minimum energy routing subject to delay constraint, and (iii) minimum delay broadcast. All of these are hard combinatorial optimization problems and we make use of several structural properties of their optimal solutions to simplify the problems and derive optimal greedy algorithms. Although the reduced problems still have exponential complexity, unlike prior works on such problems, our greedy algorithms are simple to use and do not require solving any linear programs. Further, using the insight obtained from the optimal solution to a linear network, we propose two simple heuristics that can be implemented in polynomial time in a distributed fashion and compare them with the optimal solution. Simulations suggest that both heuristics perform very close to the optimal solution over random network topologies.
Thermodynamic limits of solar cells with non-ideal optical response

The Shockley-Queisser (S-Q) theory defines the thermodynamic upper limits for Jsc, Voc, FF, and efficiency of a solar cell. The classical calculation assumes an abrupt onset of absorption at the band-edge, perfect absorption for all energies above the bandgap, and absence of non-radiative recombination. These assumptions are never satisfied for any practical solar cell. In this paper, we explain how the S-Q limits are redefined in the presence of the non-ideal optical effects, and we provide closed-form analytical expressions for the new limits for Jsc, Voc, and FF. Remarkably, these new limits can be achieved to a very high degree, even with significantly imperfect materials.
Far-Infrared Water Line Emissions from Circumstellar Outflows

We have modeled the far-infrared water line emission expected from circumstellar outflows from oxygen-rich late-type stars, as a function of the mass-loss rate and the terminal outflow velocity. For each mass-loss rate and terminal outflow velocity considered, we computed self-consistently the gas density, temperature, outflow velocity, and water abundance as a function of distance from the star. We then used an escape probability method to solve for the equilibrium level populations of 80 rotational states of water and thereby obtained predictions for the luminosity of a large number of far-infrared rotational transitions of water. In common with previous models, our model predicts that water will be copiously produced in the warm circumstellar gas and that water rotational emission will dominate the radiative cooling. However, our use of a realistic radiative cooling function for water leads to a lower gas temperature than that predicted in previous models. Our predictions for the far-infrared water line luminosities are consequently significantly smaller than those obtained in previous studies. Observations to be carried out by the Infrared Space Observatory will provide a crucial test of the models presented here.
The incidence and allocation effects of a tax on corporate distributions

Abstract To study the effects of ‘double taxation’ (first at the corporation level, then at the shareholder level) this paper analyzes a model with a tax on all corporate distributions to equity owners and no other taxes. Contrary to the common view, the tax is shown to have no subtitution effect and, in particular, no effect on the corporate choice between debt and equity (via retained earnings) finance. The analysis opens to question certain arguments commonly used to support integration of corporation and individual income taxes via ‘dividend relief’.
Rydberg atoms in curved space-time.

The possible use of loosely bound Rydberg atoms for remote gravimetric measurements is explored. The first-order corrections to the nonrelativistic nS and nP states for ng2 are obtained for the first time. A procedure to evaluate corrections of any order is outlined and applied to the 1S state in a spherical symmetry. It is shown that observations of the effects described in this Letter near objects of neutron-star-like densities are possible in principle only in the absence of significant magnetic fields.
Tensor product expansions for correlation in quantum many-body systems

We explore a class of computationally feasible approximations of the two-body density matrix as a finite sum of tensor products of single-particle operators. Physical symmetries then uniquely determine the two-body matrix in terms of the one-body matrix. Representing dynamical correlation alone as a single tensor product results in a theory that predicts near zero dynamical correlation in the homogeneous electron gas at moderate to high densities. But, representing both dynamical and statistical correlation effects together as a tensor product leads to the recently proposed ‘‘natural orbital functional.’’ We find that this latter theory has some asymptotic properties consistent with established many-body theory but is no more accurate than Hartree-Fock in describing the homogeneous electron gas for the range of densities typically found in the valence regions of solids.
Rhodium(II)-catalyzed alkyne amination of homopropargylic sulfamate esters: stereoselective synthesis of functionalized norcaradienes by arene cyclopropanation.

A rhodium(II) catalyzed nitrene–alkyne cycloaddition of stereochemically well-defined homopropargylic ethers is followed by arene cyclopropanation to afford unique tetracyclic norcaradiene products bearing a cyclic sulfamate. Products from the arene cyclopropanation (Buchner reaction) can be converted to fused cycloheptatrienes via a ring enlarging electrocyclization after nucleophilic ring opening of the cyclic sulfamate ester.
A Preliminary Study of the Human Brain Response to Oral Sucrose and Its Association with Recent Drinking

Background A preference for sweet tastes has been repeatedly shown to be associated with alcohol preference in both animals and humans. In this study, we tested the extent to which recent drinking is related to blood oxygen level–dependent (BOLD) activation from an intensely sweet solution in orbitofrontal areas known to respond to primary rewards. Methods Sixteen right-handed, non-treatment-seeking, healthy volunteers (mean age: 26 years; 75% male) were recruited from the community. All underwent a taste test using a range of sucrose concentrations, as well as functional magnetic resonance imaging (fMRI) during pseudorandom, event-driven stimulation with water and a 0.83 M concentration of sucrose in water. Results [Sucrose > water] provoked a significant BOLD activation in primary gustatory cortex and amygdala, as well as in the right ventral striatum and in bilateral orbitofrontal cortex. Drinks/drinking day correlated significantly with the activation as extracted from the left orbital area (r = 0.52, p = 0.04 after correcting for a bilateral comparison). Using stepwise multiple regression, the addition of rated sucrose liking accounted for significantly more variance in drinks/drinking day than did left orbital activation alone (multiple R = 0.79, p = 0.002). Conclusions Both the orbitofrontal response to an intensely sweet taste and rated liking of that taste accounted for significant variance in drinking behavior. The brain response to sweet tastes may be an important phenotype of alcoholism risk.
Design of Pin-Constrained General-Purpose Digital Microfluidic Biochips

Digital microfluidic biochips are being increasingly used for biotechnology applications. The number of control pins used to drive electrodes is a major contributor to the fabrication cost for disposable biochips in a highly cost-sensitive market. Most prior work on pin-constrained biochip design determines the mapping of a small number of control pins to a larger number of electrodes according to the specific schedule of fluid-handling operations and routing paths of droplets. Such designs are, therefore, specific to the bioassay application, hence sacrificing some of the flexibility associated with digital microfluidics. We propose a design method to generate an application-independent pin-assignment configuration with a minimum number of control pins. Layouts of commercial biochips and laboratory prototypes are used as case studies to evaluate the proposed design method for determining a suitable pin-assignment configuration. Compared with previous pin-assignment algorithms, the proposed method can reduce the number of control pins and facilitate the general-purpose use of digital microfluidic biochips for a wider range of applications.
Introduction to microwave background polarization

Microwave background polarization, though presently undetected, is a fundamental prediction of any viable cosmological model. These lectures review the theoretical description of polarization, its physical interpretation, and potentially interesting polarization signals.
FROM GALAXY CLUSTERS TO ULTRA-FAINT DWARF SPHEROIDALS: A FUNDAMENTAL CURVE CONNECTING DISPERSION-SUPPORTED GALAXIES TO THEIR DARK MATTER HALOS

We examine scaling relations of dispersion-supported galaxies over more than eight orders of magnitude in luminosity by transforming standard fundamental plane parameters into a space of mass, radius, and luminosity. The radius variable r1/2 is the de-projected (3-D) half-light radius, the mass varia ble M1/2 is the total gravitating mass within this radius, and L1/2 is half the luminosity. We find that from ultra-faint dwarf sp heroidals to giant cluster spheroids, dispersion-supported galaxie s scatter about a one-dimensional “fundamental curve” through this MRL space. The mass-radius-luminosity relation transitions from M1/2 � r 1.44 1/2 � L 0.30 1/2 for the faintest dwarf spheroidal galaxies to M1/2 � r 1.42 1/2 � L 3.2 1/2 for the most luminous galaxy cluster spheroids. The weakness of the M1/2 − L1/2 slope on the faint end may imply that potential well depth limits galaxy formation in small galaxies, while the stronger dependence on L1/2 on the bright end suggests that baryonic physics limits galaxy formation in massive galaxies. The mass-radius projection of this curve can be compared
Designing Dependable Storage Solutions for Shared Application Environments

The costs of data loss and unavailability can be large, so businesses use many data protection techniques such as remote mirroring, snapshots, and backups to guard against failures. Choosing an appropriate combination of techniques is difficult because there are numerous approaches for protecting data and allocating resources. Storage system architects typically use ad hoc techniques, often resulting in overengineered expensive solutions or underprovisioned inadequate ones. In contrast, this paper presents a principled automated approach for designing dependable storage solutions for multiple applications in shared environments. Our contributions include search heuristics for intelligent exploration of the large design space and modeling techniques for capturing interactions between applications during recovery. Using realistic storage system requirements, we show that our design tool produces designs that cost up to two times less in initial outlays and expected data penalties than the designs produced by an emulated human design process. Additionally, we compare our design tool to a random search heuristic and a genetic algorithm metaheuristic, and show that our approach consistently produces better designs for the cases we have studied. Finally, we study the sensitivity of our design tool to several input parameters.
Thermo/structural analysis of a large flexible paraboloid antenna.

Thermostructural analysis of large flexible paraboloid antenna indicates RF losses due to thermal distortions significant for X band and higher transmissions
Integral operators and integral cohomology classes of Hilbert schemes

The methods of integral operators on the cohomology of Hilbert schemes of points on surfaces are developed. They are used to establish integral bases for the cohomology groups of Hilbert schemes of points on a class of surfaces (and conjecturally, for all simply connected surfaces).
Fermion masses without Higgs: a supersymmetric technicolor model

Abstract We propose a supersymmetric technicolor model in which the electroweak symmetry breaking is communicated to the quarks and leptons by technicolored SU (2) w -singlet scalars. When the technifermions condense, the quarks and leptons of the third generation acquire mass. The fermions of the other generations do not couple to the technicolored scalars but they receive masses from radiative corrections involving superpartners. As a result, the mass hierarchy between the fermion generations arises naturally. The model predicts the CP asymmetries in B meson decays and in ΔS = 1 transitions to be smaller by two orders of magnitude than the ones predicted in the Standard Model.
OPEC: Retrospective and prospects 1973–1990

Abstract Using a relatively simple economic model of the world oil market, we review what has happened since the price quadrupling of 1973–1974, comparing the model's results with actual historical data. We also make projections through 1990, assuming that OPEC's real price is either held constant or determined by a target-capacity-utilization pricing rule.