cssi/SciSciGPT-SciSciNet huggingface dataset:
EGRET Observations of the Diffuse Gamma-Ray Emission in Orion: Analysis through Cycle 6

We present a study of the high-energy diffuse emission observed toward Orion by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory. The total exposure by EGRET in this region has increased by more than a factor of two since a previous study. A simple model for the diffuse emission adequately fits the data; no significant point sources are detected in the region studied (1 = 195 deg to 220 deg and b = -25 deg to -10 deg) in either the composite dataset or in two separate groups of EGRET viewing periods considered. The gamma-ray emissivity in Orion is found to be (1.65 +/- 0.11) x 10(exp -26)/s.sr for E > 100 MeV, and the differential emissivity is well-described as a combination of contributions from cosmic-ray electrons and protons with approximately the local density. The molecular mass calibrating ratio is N(H2)/W(sub CO) = (1.35 +/- 0.15) x 10(exp 20)/sq cm.(K.km/s).
Intersection numbers of Heegner divisors on Shimura curves

In foundational papers, Gross, Zagier, and Kohnen established two formulas for arithmetic intersection numbers of certain Heegner divisors on integral models of modular curves. In [GZ1], only one imaginary quadratic discriminant plays a role. In [GZ2] and [GKZ], two quadratic discriminants play a role. In this paper we generalize the two-discriminant formula from the modular curves X0(N) to certain Shimura curves defined over Q. Our intersection formula was stated in [Ro], but the proof was only outlined there. Independently, the general formula was given, in a weaker and less explicit form, in [Ke2]; there it was proved completely. This paper is thus a synthesis of parts of [Ro] and [Ke2]. The intersection multiplicities computed here were used in [Ku] to derive a relation between height pairings and special values of the derivatives of certain Eisenstein series. We note also that Zhang [Zh] has generalized all of [GZ1] from ground field Q to general totally real ground fields F , working with general Shimura curves. So we certainly expect that all of [GKZ] should generalize similarly. Our work here can be viewed as a step in this direction. We are happy to thank B. Gross and S. Kudla for their encouragement during the long period in which this work was done.
Incompressible surfaces and spunnormal form

Suppose M is a cusped finite-volume hyperbolic 3-manifold and \({\mathcal{T}}\) is an ideal triangulation of M with essential edges. We show that any incompressible surface S in M that is not a virtual fiber can be isotoped into spunnormal form in \({\mathcal{T}}\). The proof is based directly on ideas of W. Thurston.
Short-wavelength spectral response properties of semiconductor/liquid junctions

We report the first measurements of photocurrent quantum yields for semiconductor/liquid junctions in the short-wavelength region of the spectrum (200-600 nm). The key feature of this wavelength region is the short penetration depth for the absorbed photon (less than 100 A), which allows measurement of the majority carrier collection velocity. Spectra have been obtained for semiconductor/liquid, semiconductor/metal, and semiconductor/insulator/metal junctions. For all semiconductors studied (n-Si, p-Si, n-GaAs, n-InP, a-Si:H), the spectral responses of the liquid junctions showed higher quantum yields than the metal junctions, indicating greater majority carrier losses at the metal junctions. This general trend was independent of redox species, solvent, supporting electrolyte, and metal overlayer. The spectral response data can also be used to distinguish Schottky barrier behavior from electrocatalytic behavior of metal overlayers, and this approach has been used to study several semiconductor/metal film junctions in contact with electrolytes.
Pre-transplant antibody screening and anti-CD154 costimulation blockade promote long-term xenograft survival in a pig-to-primate kidney transplant model.

Xenotransplantation has the potential to alleviate the organ shortage that prevents many patients with end-stage renal disease from enjoying the benefits of kidney transplantation. Despite significant advances in other models, pig-to-primate kidney xenotransplantation has met limited success. Preformed anti-pig antibodies are an important component of the xenogeneic immune response. To address this, we screened a cohort of 34 rhesus macaques for anti-pig antibody levels. We then selected animals with both low and high titers of anti-pig antibodies to proceed with kidney transplant from galactose-α1,3-galactose knockout/CD55 transgenic pig donors. All animals received T-cell depletion followed by maintenance therapy with costimulation blockade (either anti-CD154 mAb or belatacept), mycophenolate mofetil, and steroid. The animal with the high titer of anti-pig antibody rejected the kidney xenograft within the first week. Low-titer animals treated with anti-CD154 antibody, but not belatacept exhibited prolonged kidney xenograft survival (>133 and >126 vs. 14 and 21 days, respectively). Long-term surviving animals treated with the anti-CD154-based regimen continue to have normal kidney function and preserved renal architecture without evidence of rejection on biopsies sampled at day 100. This description of the longest reported survival of pig-to-non-human primate kidney xenotransplantation, now >125 days, provides promise for further study and potential clinical translation.
Content-adaptive motion estimation for efficient video compression

Motion estimation is the most important step in the video compression. Most of the current video compression systems use forward motion estimation, where motion information is derived at the encoder and sent to the decoder over the channel. Backward motion estimation does not derive an explicit representation of motion at the encoder. Instead, the encoder implicitly embeds the motion information in an alternative subspace. Most recently, an algorithm that adopts least-square prediction (LSP) for backward motion estimation has shown great potential to further improve coding efficiency. Forward motion estimation and backward motion estimation have both their advantages and disadvantages. Each is suitable for handling some specific category of patterns. In this paper, we propose a novel approach that combines both forward motion estimation and backward motion estimation in one framework to adaptively exploit the local motion characteristics in an arbitrary video sequence, thus achieving better coding efficiency. We refer to this as Content-Adaptive Motion Estimation (CoME). The encoder in the proposed system is able to adjust the motion estimation method in a rate-distortion optimized manner. According to the experimental results, CoME reduces the data rate in both lossless and lossy compression.
Optimum wire sizing of RLC interconnect with repeaters

Repeaters are often used to drive high impedance interconnects. These lines have become highly inductive and can affect signal behavior. The line inductance should therefore be considered in determining the optimum number and size of the repeaters driving a line. The optimum repeater system uses uniform repeater insertion in order to achieve the minimum propagation delay. A tradeoff exists, however, between the transient power dissipation and the minimum propagation delay in sizing long interconnects driven by the optimum repeater system. Optimizing the line width to achieve the minimum power delay product, however, can satisfy current high speed, low-power design objectives. A reduction in power of 65% and delay of 97% is achieved for an example repeater system.The Power-Delay-Area-Product (PDAP) criterion is introduced as an efficient technique to size the interconnect within a repeater system. A reduction in buffer area of 67% and interconnect area of 46% is achieved based on the PDAP.
High-performance capillary electrophoresis

High performance capillary electrophoresis is expected to be the fastest-growing analytical technique since HPLC. The method has already shown its utility in a variety of applications.
FAST WINDS AND MASS LOSS FROM METAL-POOR FIELD GIANTS*

Echelle spectra of the infrared He I λ10830 line were obtained with NIRSPEC on the Keck 2 telescope for 41 metal-deficient field giant stars including those on the red giant branch (RGB), asymptotic giant branch (AGB), and red horizontal branch (RHB). The presence of this He I line is ubiquitous in stars with T eff 4500 K and MV fainter than –1.5, and reveals the dynamics of the atmosphere. The line strength increases with effective temperature for T eff 5300 K in RHB stars. In AGB and RGB stars, the line strength increases with luminosity. Fast outflows ( 60 km s–1) are detected from the majority of the stars and about 40% of the outflows have sufficient speed as to allow escape of material from the star as well as from a globular cluster. Outflow speeds and line strengths do not depend on metallicity for our sample ([Fe/H]= –0.7 to –3.0), suggesting the driving mechanism for these winds derives from magnetic and/or hydrodynamic processes. Gas outflows are present in every luminous giant, but are not detected in all stars of lower luminosity indicating possible variability. Mass loss rates ranging from ~3 × 10–10 to ~6 × 10–8 M ☉ yr–1 estimated from the Sobolev approximation for line formation represent values with evolutionary significance for red giants and RHB stars. We estimate that 0.2 M ☉ will be lost on the RGB, and the torque of this wind can account for observations of slowly rotating RHB stars in the field. About 0.1-0.2 M ☉ will be lost on the RHB itself. This first empirical determination of mass loss on the RHB may contribute to the appearance of extended horizontal branches in globular clusters. The spectra appear to resolve the problem of missing intracluster material in globular clusters. Opportunities exist for wind smothering of dwarf stars by winds from the evolved population, possibly leading to surface pollution in regions of high stellar density.
On the ionospheric application of Poynting's theorem

[1] It has been proposed that the geomagnetic field-aligned component of the perturbation Poynting vector above the ionosphere, as obtained from the cross product of the electric and magnetic perturbation fields observed on a spacecraft, may be used to estimate the field line-integrated electromagnetic energy dissipation in the ionosphere below. This paper clarifies conditions under which this approximation may be either valid or invalid. It is shown that the downward field-aligned component of the perturbation Poynting vector can underestimate the electromagnetic energy dissipation in regions of high ionospheric Pedersen conductance, and it can significantly overestimate the dissipation in regions of low conductance. Local values of upward perturbation Poynting vector do not necessarily correspond to net ionospheric generation of electromagnetic energy along that geomagnetic field line. An Equipotential Boundary Poynting Flux (EBPF) theorem is presented for quasi-static electromagnetic fields as follows: when a volume of the ionosphere is bounded on the sides by an equipotential surface and on the bottom by the base of the conducting ionosphere, then the area integral of the downward normal component of the perturbation Poynting vector over the top of that volume equals the energy dissipation within the volume. This equality does not apply to volumes with arbitrary side boundaries. However, the EBPF theorem can be applied separately to different components of the electric potential, such as the large- and small-scale components. Since contours of the small-scale component of potential tend to close over relatively localized regions, the associated small-scale structures of downward perturbation Poynting vector tend to be dissipated locally.
Human molars from later Pleistocene deposits of Witkrans Cave, Gaap Escarpment, Kalahari Margin

Human molars from travertine deposits of Witkrans Cave (Gaap Escarpment, northern Cape Province, South Africa) are described. The Witkrans molars were discovered in direct association with later Pleistocene faunal remains and a sample of Middle Stone Age artifacts (Peabody, 1954; Clark, 1971; Sampson, 1974; Klein, 1984; Volman, 1984). The morphology and dimensions of the Witkrans molars resemble remains from other localities of similar age in southern Africa (Singer & Wymer, 1982; Grine & Klein, 1985; Grine et al., 1991; Rightmire & Deacon 1991) but exhibit differences from later Pleistocene occurrences in northern Africa (McBurney et al. 1953; Vallois & Roche, 1958; Ennouchi, 1969; Hublin & Tillier, 1981). These results offer further support for the existence of later Pleistocene human populations south of the Sahara which were distinct from contemporaneous peoples of Mediterranean Africa (Howell, 1978; Brauer, 1984; Rightmire, 1984; Klein 1992).
C. Y. CHAO, PAIR CREATION AND PAIR ANNIHILATION

C. Y. Chao's contribution to physicists' acceptance of QED in 1933–1934 through his experiments of 1930 is analyzed. It is pointed out that Blackett and Occhialini's key suggestion of 1933 about hole theory was based on identifying Chao's "additional scattered rays" (1930) as due to pair annihilation.
The abelian monodromy extension property for families of curves

Necessary and sufficient conditions are given (in terms of monodromy) for extending a family of smooth curves over an open subset \({U \subset S}\) to a family of stable curves over S. More precisely, we introduce the abelian monodromy extension (AME) property and show that the standard Deligne–Mumford compactification is the unique, maximal AME compactification of the moduli space of curves. We also show that the Baily–Borel compactification is the unique, maximal projective AME compactification of the moduli space of abelian varieties.
Spinup Dynamics of Axial Dual-Spin Spacecraft

We consider spinup dynamics of axial dual-spin spacecraft composed of two rigid bodies: an asymmetric platform and an axisymmetric rotor parallel to a principal axis of the platform. The system is free of external torques, and spinup of the rotor is effected by a small constant internal axial torque. The dynamics are described by four first-order differential equations. Conservation of angular momentum and the method of averaging are used to reduce the problem to a single first-order differential equation which is studied numerically. This reduction has a geometric counterpart that we use to simplify the investigation of spinup dynamics. In particular, a resonance condition due to platform asymmetry and associated with an instantaneous separatrix crossing is clearly identified using our approach.
Agalma: an automated phylogenomics workflow.

Background In the past decade, transcriptome data have become an important component of many phylogenetic studies. They are a cost-effective source of protein-coding gene sequences, and have helped projects grow from a few genes to hundreds or thousands of genes. Phylogenetic studies now regularly include genes from newly sequenced transcriptomes, as well as publicly available transcriptomes and genomes. Implementing such a phylogenomic study, however, is computationally intensive, requires the coordinated use of many complex software tools, and includes multiple steps for which no published tools exist. Phylogenomic studies have therefore been manual or semiautomated. In addition to taking considerable user time, this makes phylogenomic analyses difficult to reproduce, compare, and extend. In addition, methodological improvements made in the context of one study often cannot be easily applied and evaluated in the context of other studies.
Does copyright affect reuse? : evidence from the Google Books Digitization Project

While digitization projects like Google Books have dramatically increased access to digital content, in this study I show how the ability to reuse such information and deliver value to end-users de...
A bid rent approach to housing demand

The theory of economic behavior in the housing and location market has been developed to date primarily from a long-run perspective in which the capital stock of housing is considered flexible. Within this framework, locational choice is reduced to a trade-off between commuting and land consumption [2, 8, lo]. As these models are being used increasingly to study a variety of urban phenomena, it would seem pertinent to reexamine their underlying assumption-that of mobile capital. The record of postwar housing construction in America suggests that even in a time of excessive demand, new units added only 1 or 2% to the stock each year. More importantly, the demand which resulted in this level of activity seems to have come primarily from equally rapid population growth [9]. It is not hard to imagine that with a more stable population, new construction would dwindle, and residential investment would concentrate more on replacement and rehabilitation. Housing, however, is very durable, lasting easily a century under quite adverse conditions. As long as units are even partially maintained, their existing rent provides a high opportunity cost against which replacement or extensive alteration can rarely compete. For a lo-20 year planning horizon, a model in which the existing stock is considered completely rigid may be a better approximation than one in which capital is completely mobile. If consumer decisions occur in a world of rigid capital, then the various attributes of housing, and their distribution over space in the existing stock, will be the important determinant of locational choice. In keeping with this view, a number of researchers have recently developed models of short-run consumer behavior, in which a mutually exclusive choice is made from among
Investigation of Compressor Rotor Wake Structure at Peak Pressure Rise Coefficient and Effects of Loading

This paper reports an experimental study of the three-dimensional characteristics of the mean velocity in the trailing-edge, near-wake, and far-wake regions of a highly loaded low-speed compressor rotor. The wake structure and decay characteristics are compared with the wake data in the same compressor with moderate loading. The experimental investigation was carried out using a rotating five-hole probe. The flow field was surveyed at various radial and axial locations downstream of the compressor rotor. Variations in the axial, tangential, and radial components of mean velocity at various axial and radial locations were derived from the data and compared with earlier data at lower loading to discern the effects of loading. It was found that the higher loading had the following effects: Higher total velocity defects were observed in the hub-wall region, increased wake growth rate in the tip region, faster decay of static pressure difference in the trailing-edge region, larger initial wake width in the trailing-edge region, increased rate of growth of the semi-wake width in the trailing-edge region, increased decay rate of radial velocity in the trailing-edge region, and decreased decay rate of the radial velocity in the far-wake region. Far wake properties were almost identical in both cases.
Holography and hydrodynamics: Diffusion on stretched horizons

We show that long-time, long-distance fluctuations of plane-symmetric horizons exhibit universal hydrodynamic behavior. By considering classical fluctuations around black-brane backgrounds, we find both diffusive and shear modes. The diffusion constant and the shear viscosity are given by simple formulas, in terms of metric components. For a given metric, the answers can be interpreted as corresponding kinetic coefficients in the holographically dual theory. For the near-extremal Dp, M2 and M5 branes, the computed kinetic coefficients coincide with the results of independent AdS/CFT calculations. In all the examples, the ratio of shear viscosity to entropy density is equal to hbar/(4? kB), suggesting a special meaning of this value.
Location, control and innovation in knowledge-intensive industries

The rising share of intangibles in economies worldwide highlights the crucial role of knowledge-intensive and creative industries in current and future wealth generation. The recognition of this trend has led to intense competition in these industries. At the micro-level, firms from both advanced and emerging economies are globally dispersing their value chains to control costs and leverage capabilities. The geography of innovation is the outcome of a dynamic process whereby firms from emerging economies strive to catch-up with advanced economy competitors, creating strong pressures for continued innovation. However, two distinct strategies can be discerned with regard to the control of the value chain. A vertical integration strategy emphasizes taking advantage of ‘linkage economies’ whereby controlling multiple value chain activities enhances the efficiency and effectiveness of each one of them. In contrast, a specialization strategy focuses on identifying and controlling the creative heart of the value chain, while outsourcing all other activities. The global mobile handset industry is used as the template to illustrate the theory.
Damage to the shallow Landers fault from the nearby Hector Mine earthquake

Crustal faults have long been identified as sites where localized sliding motion occurs during earthquakes, which allows for the relative motion between adjacent crustal blocks. Although there is a growing awareness that we must understand the evolution of fault systems on many timescales to relate present-day crustal stresses and fault motions to geological structures formed in the past, fault-zone damage and healing have been documented quantitatively in only a few cases. We have been monitoring the healing of damage on the shallow Johnson Valley fault after its rupture in the 1992 magnitude-7.3 Landers earthquake, and here we report that this healing was interrupted in 1999 by the magnitude-7.1 Hector Mine earthquake rupture, which occurred 20-30 km away. The Hector Mine earthquake both strongly shook and permanently strained the Johnson Valley fault, adding damage discernible as a temporary reversal of the healing process. The fault has since resumed the trend of strength recovery that it showed after the Landers earthquake. These observations lead us to speculate that fault damage caused by strong seismic waves may help to explain earthquake clustering and seismicity triggering by shaking, and may be involved in friction reduction during faulting.
Observing Zitterbewegung with Ultracold Atoms

We propose an optical lattice scheme which would permit the experimental observation of Zitterbewegung (ZB) with ultracold, neutral atoms. A four-level tripod variant of the setup for stimulated Raman adiabatic passage (STIRAP) has previously been proposed for generating non-Abelian gauge fields. Dirac-like Hamiltonians, which exhibit ZB, are simple examples of such non-Abelian gauge fields; we show how a variety of them can arise, and how ZB can be observed, in a tripod system. We predict that the ZB should occur at experimentally accessible frequencies and amplitudes.
Challenging the enforcement of environmental regulation

If a firm can contest the enforcement of an environmental regulation, neither increasing the probability nor severity of the fine will guarantee a reduction in a firm's illegally dumped waste. A policy that can unambiguously decrease illegal dumping is lowering the cost of legal disposal. This result occurs because the use of monitoring and fines to increase the probability or severity of enforcement triggers investment to evade enforcement, while a decrease in the costs of legal disposal does not. Investment in the resources to evade enforcement decreases the attractiveness of monitoring by significantly increasing the costs of environmental audits, administrative hearings, and judicial procedures. This occurs even with a high degree of regulator information about the firm's cost structure and no monitoring errors. In addition, if the regulator can only imperfectly monitor a firm's behavior so the firm can be accused of another firm's behavior, observable commitment to challenge enforcement will lead to overinvestment in resources to evade enforcement, an increased level of illegal dumping, and an overall increase in total costs relative to the unobservable case.
The role of professionals in the Chandler paradigm

Since many of the modern professions had a substantial impact on economic development, this essay examines Alfred D. Chandler's description and analysis of the business-related aspects of professionalization. According to Chandler, professional managers, scientists, and engineers made crucial contributions to the expansion of large enterprises in the late nineteenth and twentieth centuries, and these firms, Chandler contended, were the most important drivers of economic growth in America and the other developed economies. While this essay agrees with many aspects of that conclusion, it contends that the social transformation that brought professionals into power in business was more contested, more difficult to organize, and frequently less successful than Chandler indicated. Moreover, that transformation and the development of business capabilities in the 20th century cannot be understood without looking outside of the firm more than Chandler did. It is necessary to analyze the public and non-profit institutions that made professional development possible in the United States and elsewhere. It is also necessary to take note of the shifting public evaluations of the professions--those inside as well as outside of the business sector. Copyright 2010 The Author 2010. Published by Oxford University Press on behalf of Associazione ICC. All rights reserved., Oxford University Press.
The Bathsheba Syndrome: The ethical failure of successful leaders

Reports of ethical violations by upper level managers continue to multiply despite increasing attention being given to ethics by firms and business schools. Much of the analysis of these violations focuses on either these managers'lack of operational principles or their willingness to abandon principles in the face ofcompetitive pressures. Much of the attention by firms and business schools focuses either on the articulation of operational principles (a deontological approach) or on the training of managers to sort their way through subtle ethical dilemmas in the face of competitive pressure (a utilitarian approach). While valuable, these approaches alone are incomplete. This paper suggests that many ethical violations by upper managers are the by-product ofsuccess — not of competitive pressures. Our research suggests that many managers are poorly prepared to deal with success. First, success often allows managers to becomecomplacent and to lose focus, diverting attention to things other than the management of their business. Second, success, whether personal or organizational, often leads toprivileged access to information, people or objects. Third, with success usually comes increasinglyunrestrained control of organizational resources. And fourth, success can inflate a manager's belief in his or her personalability to manipulate outcomes. Even individuals with a highly developed moral sense can be challenged (tempted?) by the “opportunities” resulting from the convergence of these dynamics. We label the inability to cope with and respond to the by-products of success “the Bathsheba Syndrome,” based on the account of the good King David (a story familiar in a variety of traditions). Recognition of this phenomenon implies that we change or broaden our approach to the teaching of business ethics. It also implies that organizations must re-evaluate and change structures, procedures, and practices which enhance the likelihood of managers falling victim to the Bathsheba Syndrome.
Integration of active and passive sensors for obstacle avoidance

A study is made of the automatic obstacle-avoidance guidance problem under the operational constraints imposed by the rotorcraft nap-of-the-earth (NOE) environment. The topic is discussed under two different circumstances. The first one assumes that a full range map is available, irrespective of the type of sensor being used. Two approaches are proposed to extend a two-dimensional obstacle-avoidance concept presented in a previous report. The situation where only a sparse range map is available from a passive sensor is also treated. An integrated approach to augment the passive sensor with an active one is discussed, along with the problem of data fusion and how it is affected by the characteristics of NOE flight. >
Targeted malleability: homomorphic encryption for restricted computations

We put forward the notion of targeted malleability: given a homomorphic encryption scheme, in various scenarios we would like to restrict the homomorphic computations one can perform on encrypted data. We introduce a precise framework, generalizing the foundational notion of non-malleability introduced by Dolev, Dwork, and Naor (SICOMP '00), ensuring that the malleability of a scheme is targeted only at a specific set of "allowable" functions.In this setting we are mainly interested in the efficiency of such schemes as a function of the number of repeated homomorphic operations. Whereas constructing a scheme whose ciphertext grows linearly with the number of such operations is straightforward, obtaining more realistic (or merely non-trivial) length guarantees is significantly more challenging.We present two constructions that transform any homomorphic encryption scheme into one that offers targeted malleability. Our constructions rely on standard cryptographic tools and on succinct non-interactive arguments, which are currently known to exist in the standard model based on variants of the knowledge-of-exponent assumption. The two constructions offer somewhat different efficiency guarantees, each of which may be preferable depending on the underlying building blocks.
Towards a Revised Monte Carlo Neutral Particle Surface Interaction Model

The components of the neutral- and plasma-surface interaction model used in the Monte Carlo neutral transport code DEGAS 2 are reviewed. The idealized surfaces and processes handled by that model are inadequate for accurately simulating neutral transport behaviour in present day and future fusion devices. We identify some of the physical processes missing from the model, such as mixed materials and implanted hydrogen, and make some suggestions for improving the model.
Na27Ru14O48: A new mixed-valence sodium ruthenate with magnetic heptameric plaquettes

Abstract Na27Ru14O48 has been synthesized in air at 700 °C. The composition and crystal structure of the phase were determined by single crystal X-ray diffraction. The triclinic crystal structure contains isolated planar Ru7O24 plaquettes made from seven edge-sharing RuO6 octahedra. The complex Na:Ru ratio is a result of tilting of the plaquettes to disrupt the packing of nominally hexagonal close packed planes made of Na ions and RuO6 octrahedra. Resistivity measurements show that the material is semiconducting with an activation energy of 0.53 eV. The observed magnetic moment of 3.11 μB per Ru is lower than the expected spin only value, but is within the range seen in other compounds and is too large to indicate that the fundamental magnetic entities are the isolated Ru7O24 plaquettes. Small, reproducible deviations in the Curie–Weiss behavior occur below 200 K and the onset of a broad magnetic transition is seen between 40 and 32 K.
Comparing Experimental and Matching Methods Using a Large-Scale Voter Mobilization Experiment

In the social sciences, randomized experimentation is the optimal research design for establishing causation. However, for a number of practical reasons, researchers are sometimes unable to conduct experiments and must rely on observational data. In an effort to develop estimators that can approximate experimental results using observational data, scholars have given increasing attention to matching. In this article, we test the performance of matching by gauging the success with which matching approximates experimental results. The voter mobilization experiment presented here comprises a large number of observations (60,000 randomly assigned to the treatment group and nearly two million assigned to the control group) and a rich set of covariates. This study is analyzed in two ways. The first method, instrumental variables estimation, takes advantage of random assignment in order to produce consistent estimates. The second method, matching estimation, ignores random assignment and analyzes the data as though they were nonexperimental. Matching is found to produce biased results in this application because even a rich set of covariates is insufficient to control for preexisting differences between the treatment and control group. Matching, in fact, produces estimates that are no more accurate than those generated by ordinary least squares regression. The experimental findings show that brief paid get-out-the-vote phone calls do not increase turnout, while matching and regression show a large and significant effect.
Geomagnetics and Scientific Institutions in 19th Century America

The earth's magnetism was a subject of intense interest among America's most prominent scientists in the middle of the 19th century. By 1850 they had helped to create an international network of cooperation for its observation. They had founded three magnetic observatories and were planning a fourth for the fledgling Smithsonian Institution. Yet by the mid-1860's, none of these observatories remained in operation.
Analyses of the Pathways Involved in Early- and Late-Phase Induction of IFN-Beta during C. muridarum Infection of Oviduct Epithelial Cells

We previously reported that the IFN-β secreted by Chlamydia muridarum-infected murine oviduct epithelial cells (OE cells) was mostly dependent on the TLR3 signaling pathway. To further characterize the mechanisms of IFN-β synthesis during Chlamydia infection of OE cells in vitro, we utilized specific inhibitory drugs to clarify the roles of IRF3 and NF-κB on both early- and late-phase C. muridarum infections. Our results showed that the pathways involved in the early-phase of IFN-β production were distinct from that in the late-phase of IFN-β production. Disruption of IRF3 activation using an inhibitor of TBK-1 at early-phase Chlamydia infection had a significant impact on the overall synthesis of IFN-β; however, disruption of IRF3 activation at late times during infection had no effect. Interestingly, inhibition of NF-κB early during Chlamydia infection also had a negative effect on IFN-β production; however, its impact was not significant. Our data show that the transcription factor IRF7 was induced late during Chlamydia infection, which is indicative of a positive feedback mechanism of IFN-β synthesis late during infection. In contrast, IRF7 appears to play little or no role in the early synthesis of IFN-β during Chlamydia infection. Finally, we demonstrate that antibiotics that target chlamydial DNA replication are much more effective at reducing IFN-β synthesis during infection versus antibiotics that target chlamydial transcription. These results provide evidence that early- and late-phase IFN-β production have distinct signaling pathways in Chlamydia-infected OE cells, and suggest that Chlamydia DNA replication might provide a link to the currently unknown chlamydial PAMP for TLR3.
Acceptable and predominant correlated equilibria

For stategic-form games with communication, acceptable correlated equilibria are defined as correlated equilibria that are stable when every player has an infinitesimal probability of trembling to any of his feasible actions. A set of acceptable actions is defined for each player, and it is shown that a correlated equilibrium is acceptable if and only if all unacceptable actions have zero probability. The unacceptable actions can be found by computing certain vectors called codomination systems, which extend the concept of dominated actions. Predominant correlated equilibria are defined by iterative elimination of unacceptable actions and are shown to exist.
A Digital Image of the City: 3D Isovists in Lynch's Urban Analysis:

New techniques to measure 2D and 3D visibility over urban spaces are presented in this paper. The concept of the isovist, that is, the visible space from a vantage point, could help in providing a ...
Digital cultural collections in an age of reuse and remixes

This paper explores the question of under what circumstances CI should seek to control non-commercial reuse of digital cultural works. It describes the results of a 2008 survey of CI professionals at U.S. archives, libraries and museums which gathered data on motivations to control access to and use of digital collections, factors discouraging control, and levels of concern associated with different types of unauthorized reuse. Analysis presents three general themes that explain many of the CI motivations for control:“Controlling descriptions and representations,” “Legal risks and complexities” and “Getting credit: fiscal and social costs and revenue.” It concludes by offering a set of examples of varying levels of reuse control (from none to complete) to serve as heuristics.
Two-dimensional black hole and singularities of CY manifolds

We study the degenerating limits of superconformal theories for compactifications on singular K3 and Calabi-Yau threefolds. We find that in both cases the degeneration involves creating an Euclidean two-dimensional black hole coupled weakly to the rest of the system. Moreover we find that the conformal theory of A_n singularities of K3 are the same as that of the symmetric fivebrane. We also find intriguing connections between ADE (1, n) non-critical strings and singular limits of superconformal theories on the corresponding ALE space.
Constraints on the Late Holocene Anthropogenic Contribution to the Atmospheric Methane Budget

The origin of the late preindustrial Holocene (LPIH) increase in atmospheric methane concentrations has been much debated. Hypotheses invoking changes in solely anthropogenic sources or solely natural sources have been proposed to explain the increase in concentrations. Here two high-resolution, high-precision ice core methane concentration records from Greenland and Antarctica are presented and are used to construct a high-resolution record of the methane inter-polar difference (IPD). The IPD record constrains the latitudinal distribution of emissions and shows that LPIH emissions increased primarily in the tropics, with secondary increases in the subtropical Northern Hemisphere. Anthropogenic and natural sources have different latitudinal characteristics, which are exploited to demonstrate that both anthropogenic and natural sources are needed to explain LPIH changes in methane concentration.
Causality and Feedback Between Institutional Measures and Economic Growth

Recent cross-section studies have demonstrated a strong link between measures of corruption, bureaucratic quality, property rights, and other institutional variables, and economic growth. In this paper we build on previous research and present some empirical evidence on the direction of causality between institutional measures and growth. It appears that the poorer the country, and the longer the wait, the higher the influence of institutional quality on economic growth. However, we also show the existence of reverse causality. Indeed, it appears that economic growth also causes institutional quality.
Higher-order Jordan Osserman pseudo-Riemannian manifolds

We study the higher-order Jacobi operator in pseudo-Riemannian geometry. We exhibit a family of manifolds so that this operator has constant Jordan normal form on the Grassmannian of subspaces of signature (r, s) for certain values of (r, s). These pseudo-Riemannian manifolds are new and non-trivial examples of higher-order Osserman manifolds.
Cross-cultural effects in E-retailing: The moderating role of cultural confinement in differentiating Mexican from non-Mexican Hispanic consumers

Abstract The United States Hispanic Internet user is a growing and relatively unexplored segment in the marketing literature. This research addresses this void by assessing how key cultural characteristics of U.S. Hispanic consumers influence their behaviors online. Examining a multi-cultural sample of Mexican Hispanic and non-Mexican Hispanic consumers, this study examines the influence of acculturation and cultural confinement, defined here as communal isolation, on repurchase intentions and positive word-of-mouth intentions in the context of Spanish-language websites, as well as their influence upon online social communication. The results indicate significant effects of both acculturation and cultural confinement on the behaviors of Hispanic online consumers, especially highlighting noteworthy differences between Mexican and non-Mexican Hispanic consumers regarding the interaction of these effects. The study provides implications for marketing to Hispanic consumers and future research directions.
Factors affecting cross-border mergers and acquisitions: The Canada-U.S. experience

This study applies a well-known approach for the analysis of investment projects to the investigation of cross-border mergers and acquisitions between Canadian and American firms in the period 1982-1990. The major purpose of the paper is to document the extent of the contribution of macroeconomic variables, such as exchange rates, bond yields, stock prices, and P/E ratios, to the recent trends in Canada-U.S. and U.S.- Canada cross-border acquisitions, as distinct from industry and firm-specific variables. The results suggest that the levels of the yields on long-term debt securities in both countries and their difference contribute significantly to an explanation of the difference of Canadian acquisitions of U.S. firms and American acquisition of Canadian firms in the period.
The Central value of the Rankin–Selberg L-Functions

Let f be a Maass form for SL\((3, {\mathbb{Z}})\) which is fixed and uj be an orthonormal basis of even Maass forms for SL\((2, {\mathbb{Z}})\), we prove an asymptotic formula for the average of the product of the Rankin–Selberg L-function of f and uj and the L-function of uj at the central value 1/2. This implies simultaneous nonvanishing results of these L-functions at 1/2.
Reductive conjugate addition of haloalkanes to enones to form silyl enol ethers.

A new method is presented for tandem reductive conjugate addition and silyl enol ether formation from cyclic and acyclic enones and enals in the presence of a Mn reductant, a Ni(terpyridine) catalyst, and a trialkylchlorosilane. The addition of secondary, tertiary, and hindered primary haloalkanes is demonstrated. Preliminary studies on the mechanism show that the intermediacy of L1(Ni)(η3-1-triethylsilyloxyalkenyl)X or in-situ-formed RMnX is unlikely.
Reactivity of seventeen- and nineteen-valence electron complexes in organometallic chemistry

A guideline to the reactivity of 17- and 19-valence electron species in organometallic chemistry is proposed which the authors believe will supersede all others. The thesis holds that the reactions of 17-electron metal radicals are associatively activated with reactions proceeding through a 19-valence electron species. The disparate reaction chemistry of the 17-electron metal radicals are unified in terms of this associative reaction pathway, and the intermediacy of 19-valence electron complexes in producing the observed products is discussed. It is suggested that related associatively activated pathways need to be considered in some reactions that are thought to occur by more conventional routes involving 16- and 18-electron intermediates. The basic reaction chemistry and electronic structures of these species are briefly discussed.
Effects of Thermal and Mechanical Loading on PDC Bit Life

The results of numerical analyses conducted to determine the effects of thermal and mechanical loading on the integrity of polycrystalline diamond compact (PDC) cutters during deep hole drilling are presented. Cutter temperature distributions for several drilling environments are combined with appropriate mechanical cutting loads to predict stress distributions for the study of cutter wear mechanisms. A discussion of wear mechanisms acting on the cutting structure is presented. Suggestions are presented, based on these analyses, for the operation of PDC bits to increase bit life in hard, abrasive rock drilling. Microstructural design considerations for the cemented carbide that supports the diamond layer are also discussed.
Microstore - The Stanford Analog Memory Unit

An NMOS device has been developed which provides high speed analog signal storage and readout for time expansion of transient signals. This device takes advantage of HMOS-1 VLSI technology to implement an array of 256 storage cells. Sequential samples of an input waveform can be taken every 5 ns while providing an effective sampling aperture time of less than 1 ns. The design signal-to-noise ratio is 1 part in 2000. Digital control circuitry is provided on the chip for controlling the read-in and read-out processes. A reference circuit is incorporated in the chip for first order compensation of leakage drifts, sampling pedestals, and temperature effects.
Cosmological perturbations for an inflaton field coupled to radiation

Within the framework of the interacting fluid formalism, we provide the numerical solution to the Boltzmann equation describing the evolution of an inflaton field coupled to radiation. We study the behavior of the system during the slow-roll regime, in the case in which an additional stochastic source term is included in the set of equations, and we recover the expression for the cosmological perturbations previously obtained in the Warm inflation scenarios.
Raman spectroscopic study of molecular orientation in vitreous B2O3 films

Abstract Preferred orientation of a molecular unit in vitreous B2O3 films prepared under tensile stress is demonstrated by laser Raman spectroscopy. The polarized Raman scattering is reported and found to be strongly dependent on simple orientation and polarization of the incident and scattered light. The ratios of scattering intensities in the various scattering arrangements for films are substantially different from those for bulk B2O3(gl). Calculated Raman intensity ratios based upon the proposed oriented boroxol ring structure compare well with the experimental values. These results demonstrate the tendency of a molecular unit with the properties of a boroxol ring to become preferentially oriented in response to an applied stress, and provide evidence for the existence of boroxol rings in B2O3(gl).
Ground state and excited states of a trapped dilute condensed Bose gas

I review recent theoretical treatments of a dilute interacting condensed Bose gas in a trap. Bogoliubov's classic results for a uniform condensate are generalized to include the effect of a trap, using the Gross-Pitaevskii formalism (for the condensate) and the Bogoliubov equations (for the linearized small-amplitude excitations of the condensate). Several recent theoretical studies are discussed along with some open questions.