cssi/SciSciGPT-SciSciNet huggingface dataset:
Measuring the Lifetime Value of Customers Acquired from Google Search Advertising

Our main objective in this paper is to measure the value of customers acquired from Google search advertising accounting for two factors that have been overlooked in the conventional method widely adopted in the industry: 1 the spillover effect of search advertising on customer acquisition and sales in off-line channels and 2 the lifetime value of acquired customers. By merging Web traffic and sales data from a small-sized U.S. firm, we create an individual customer-level panel that tracks all repeated purchases, both online and off-line, and tracks whether or not these purchases were referred from Google search advertising. To estimate the customer lifetime value, we apply the methodology in the customer relationship management literature by developing an integrated model of customer lifetime, transaction rate, and gross profit margin, allowing for individual heterogeneity and a full correlation of the three processes. Results show that customers acquired through Google search advertising in our data have a higher transaction rate than customers acquired from other channels. After accounting for future purchases and spillover to off-line channels, the calculated value of new customers using our approach is much higher than the value obtained using conventional method. The approach used in our study provides a practical framework for firms to evaluate the long-term profit impact of their search advertising investment in a multichannel setting.
Global asymptotic stability of optimal control systems with applications to the theory of economic growth

Publisher Summary This chapter discusses the global asymptotic stability of optimal control systems with applications to the theory of economic growth. The qualitative study of optimal economic growth has attracted the attention of economic theorists for a few years. One major focus of this research has been to find sufficient conditions on models of economic growth for the convergence of growth paths to a steady state. In this symposium volume of the Journal of Economic Theory, Cass and Shell present the Hamiltonian formulation of competitive dynamical systems that arise in capital theory. The chapter presents a set of sufficient conditions on the Hamiltonian for such dynamical systems to converge to a steady state as time tends to infinity. The chapter also presents new results that build on the work of Cass and Shell, Rockafellar, and Hartman and Olech. It discusses the three basic types of results obtained and their relation to the literature.
A Practical Method for Enantioselective Synthesis of All-Carbon Quaternary Stereogenic Centers through NHC-Cu-Catalyzed Conjugate Additions of Alkyl- and Arylzinc Reagents to β-Substituted Cyclic Enones

We present the first examples of Cu-catalyzed enantioselective conjugate additions of alkyl- and arylzinc reagents to unactivated cyclic beta-substituted enones. Transformations are promoted in the presence of 2.5-15 mol % of a readily available chiral NHC-based Cu complex, affording the desired products bearing all-carbon quaternary stereogenic centers in 67-->98% yield and in up to 97% ee. Catalytic enantioselective reactions can be carried out on a benchtop, with undistilled solvent and commercially available (not further purified) Cu salts. Mechanistic models, accounting for the observed levels and trends in enantioselectivity are provided.
Is Economic Reform Popular at the Polls? Russia 1995

Abstract This paper provides evidence that Russian regions that experienced greater reforms, e.g., small-scale privatization and price liberalization, through Autumn 1995 exhibited greater support for reform in the December 1995 parliamentary elections. This positive association is not easily dismissed as a spurious result caused by regional differences in urbanization, economic growth, education attainment, wage arrears, natural resource endowments, or poverty rates. It is also not easily dismissed as a coincidence driven by the fact that some regions were inherently pro-reform because it remains after holding constant the region's vote for Yeltsin in the 1991 elections. Using republic status (measuring administrative autonomy) as an instrument for privatization supports the interpretation that reform itself caused electoral support for reform. Overall, the evidence supports the view that reforms created a positive feedback through the ballot box, rather than the alternative hypothesis that reforms created a backlash against reforms, as many observers feared when formulating transition strategy in the early 1990's. J. Comp. Econ., September 2001, 29(3), pp. 448–465. Harvard University, Cambridge, Massachusetts 02138. Copyright 2001 Academic Press. Journal of Economic Literature Classification Numbers: P2.
Intramolecular hydrogen atom abstraction: The β-oxygen effect in the Norrish type II photoreaction

Abstract The preparation of phenacyl glycosides of α- and β-tetrabenzylglucopyranose, of α-tetrabenzylmannopyranose, and of 2-hydroxytetrahydropyran is described. Photolysis of each compound through Pyrex results cleanly in lactone formation by the Norrish type II photocleavage. Competition experiments are described which demonstrate that both glucosyl anomers are consumed at the same rate in the course of the photolysis. Similar experiments establish that the phenacyl α-glucoside is marginally more reactive than the corresponding α-mannoside. The tetrahydropyran derivative is cleaved much more rapidly the carbohydrates. This effect is interpreted in terms destabilizalion of the polarized transition stale for hydrogen atom abstraction by the β-oxygen bonds in the carbohydrate series.
Hypocholesterolemic Agents IV: Inhibition of β‐Hydroxy‐β‐Methylglutaryl Coenzyme A Reductase by Arylalkenyl and Arylepoxy Hydrogen Succinates and Glutarates

Abstract Two series of half acid esters of succinic and glutaric acids were synthesized and assayed for inhibition of rat liver β‐hydroxy‐β‐methylglutaryl coenzyme A reductase. Irreversible inhibition was studied by incorporation of a potential alkylating group (the epoxide function) into the side chain of the alcohol portion of the half acid esters. Incorporation of a terminal olefin function into the side chain of the alcohol portion of the half acid esters provided a group that could form a charge–transfer complex. Neither irreversible inhibition nor formation of a charge–transfer complex was indicated from these studies; however, the two series of half acid esters exhibited reversible inhibition.
Ratio of Quark Masses in Duality Theories

We consider N=2 SU(2) Seiberg–Witten duality theory for models with Nf=2 and Nf=3 quark flavors. We investigate arbitrary large bare mass ratios between two or three quarks at the singular points. For Nf=2 we explore large bare mass ratios corresponding to a singularity in the strong coupling region. For Nf=3 we determine the location of both strong and weak coupling singularities that produce specific large bare mass ratios.
A stereoselective synthesis of (Z)-1-iodo-1-alkenes

Abstract (Z)-1-iodo-1-alkenes can be synthesized stereoselectively via the Wittig reaction of iodomethylenetriphenylphosphorane with aldehydes.
Effect of Solar Wind Drag on the Determination of the Properties of Coronal Mass Ejections from Heliospheric Images

The Fixed-Φ (FΦ) and Harmonic Mean (HM) fitting methods are two methods to determine the “average” direction and velocity of coronal mass ejections (CMEs) from time–elongation tracks produced by Heliospheric Imagers (HIs), such as the HIs onboard the STEREO spacecraft. Both methods assume a constant velocity in their descriptions of the time–elongation profiles of CMEs, which are used to fit the observed time–elongation data. Here, we analyze the effect of aerodynamic drag on CMEs propagating through interplanetary space, and how this drag affects the result of the FΦ and HM fitting methods. A simple drag model is used to analytically construct time–elongation profiles which are then fitted with the two methods. It is found that higher angles and velocities give rise to greater error in both methods, reaching errors in the direction of propagation of up to 15∘ and 30∘ for the FΦ and HM fitting methods, respectively. This is due to the physical accelerations of the CMEs being interpreted as geometrical accelerations by the fitting methods. Because of the geometrical definition of the HM fitting method, it is more affected by the acceleration than the FΦ fitting method. Overall, we find that both techniques overestimate the initial (and final) velocity and direction for fast CMEs propagating beyond 90∘ from the Sun–spacecraft line, meaning that arrival times at 1 AU would be predicted early (by up to 12 hours). We also find that the direction and arrival time of a wide and decelerating CME can be better reproduced by the FΦ due to the cancelation of two errors: neglecting the CME width and neglecting the CME deceleration. Overall, the inaccuracies of the two fitting methods are expected to play an important role in the prediction of CME hit and arrival times as we head towards solar maximum and the STEREO spacecraft further move behind the Sun.
QUANTITATIVE AND FUNCTIONAL CHANGE IN T CELLS OF PRIMIPAROUS MICE FOLLOWING INJECTION OF BENZO(a)PYRENE AT THE SECOND TRIMESTER OF PREGNANCY

AbstractProgeny from benzo(a)pyrene (BP) mposed (150 ug/g body weight) primiparous mothers, injected during the second trimester of pregnancy, are severely compromised immunologically. In view of maternal-fetal associations, we studied, during pregnancy and postpartum, the quantitative and functional status of the maternal T cell population in the thymus and/or spleen. In the thymus, there is an exacerbated depression in the amounts of thymocytes, (tH+, Lyt 1+, Lyt 2+ cells) during pregnancy relative to the corn oil-injected controls, which is sustained postpartum. In the spleen, while there are inconsistencies in the level of θ+ cells, The Lyt 1+ are depressed postpartum relative to virgins, but the Lyt 2+ are enhanced during pregnancy and postpartum, reaching levels <700-fold of controls. In controls, while the number of Lyt 1+ cells was higher than BP-exposed mice or virgins during pregnancy, they virtually disappeared postpartum. A similar but reversed image is mirrored by the Lyt 2+ cells, i.e., they...
Efficient Pd-catalyzed coupling of tautomerizable heterocycles with terminal alkynes via C-OH bond activation using PyBrOP.

The direct alkynylation of tautomerizable heterocylcles is described via a two-step process involving in situ C-OH activation with bromotripyrrolidinophosphonium hexafluorophosphate (PyBrOP) followed by Sonogashira coupling with a wide range of alkyl or aryl terminal alkynes using a copper free system employing PdCl2(CH3CN)2 and 2-(dicyclohexylphosphino)biphenyl.
Prostate cancer: Effects of tertiary Gleason pattern 5 on oncological outcome

The prognostic implications of a tertiary component of Gleason pattern 5 cancer at radical prostatectomy remain incompletely understood. A newly published study highlights the relationship between tertiary pattern 5 cancer, other risk factors and clinical outcomes. Authors propose a prognostic model to identify patients with the greatest need for adjuvant therapy.
Problems encountered by novice pair programmers

In a study of the types of problems encountered by students that lead them to seek assistance, Robins, Haden, and Garner [8] found that the most common problems were related to trivial mechanics. The students in this study worked by themselves on their programming exercises. This paper discusses a replication of the Robins et al. study in which the subjects pair programmed. The types of problems encountered by the pairing students were similar to those of the solo students. The number of problems requiring assistance was much smaller for the pairing students, which suggests that they were able to resolve more problems on their own.
Global warming pattern formation: sea surface temperature and rainfall.

Abstract Spatial variations in sea surface temperature (SST) and rainfall changes over the tropics are investigated based on ensemble simulations for the first half of the twenty-first century under the greenhouse gas (GHG) emission scenario A1B with coupled ocean–atmosphere general circulation models of the Geophysical Fluid Dynamics Laboratory (GFDL) and National Center for Atmospheric Research (NCAR). Despite a GHG increase that is nearly uniform in space, pronounced patterns emerge in both SST and precipitation. Regional differences in SST warming can be as large as the tropical-mean warming. Specifically, the tropical Pacific warming features a conspicuous maximum along the equator and a minimum in the southeast subtropics. The former is associated with westerly wind anomalies whereas the latter is linked to intensified southeast trade winds, suggestive of wind–evaporation–SST feedback. There is a tendency for a greater warming in the northern subtropics than in the southern subtropics in accordance ...
Fractional quantum Hall effect in higher Landau levels

Abstract We investigate, using finite size numerical calculations, the spin-polarized fractional quantum Hall effect (FQHE) in the first excited Landau level (LL). We find evidence for the existence of an incompressible state at v = 7 3 = 2 + 1 3 , but not at v = 2 + 2 5 . Surprisingly, the 7 3 state is found to be strongest at a finite thickness. The structure of the low-lying excited states is found to be markedly different from that in the lowest LL. This study also rules out FQHE at a large number of odd-denominator fractions in the lowest LL.
Strategy-proofness versus efficiency for small domains of preferences over public goods

It has long been known that when agents have von Neumann-Morgenstern preferences over lotteries, there is an incompatibility between strategy-proofness and efficiency (Gibbard, [9]; Hylland, [12]) – a solution satisfying those properties must be dictatorial. We strengthen this result by showing that it follows from the same incompatibility on a series of much smaller domains of preferences. Specifically, we first show the incompatibility to hold on our smallest domain, in which two agents are restricted to have linear preferences over one private good and one public good produced from the private good (Kolm triangle economies). This result then implies the same incompatibility on increasingly larger domains of preferences, ending finally with the class of von Neumann-Morgenstern preferences over lotteries.
Dietary restriction in rhesus monkeys: lymphopenia and reduced mitogen-induced proliferation in peripheral blood mononuclear cells.

Dietary restriction (DR) markedly extends mean and maximal life span, and retards the rate of biological aging in rodent models; however, it is unknown if these results occur in primate species. The purpose of the current study was to investigate selected immunologic outcomes in Rhesus monkeys subjected to DR for a period of seven years. Similar to observations in mice on DR, lymphopenia occurred in the restricted monkeys. Compared to normally fed controls, the mitogen-induced proliferative responses of peripheral blood mononuclear cells (PBMC) were reduced in monkeys subjected to DR very early in life (up to 1 year), but not in others restricted in young adulthood (3–5 years). These data indicate that lymphopenia is a shared occurrence in rodents and primates on DR. However, the mitogeninduced proliferative data accumulated in rodents and primates cannot now be compared because PBMC have not been studied long enough or in comparable detail in primates fed restricted diets.
Activation of Carbonyl-Containing Molecules with Solid Lewis Acids in Aqueous Media

Current interest in reacting carbonyl-containing molecules in aqueous media is primarily due to the growing emphasis on conversion of biomass to fuels and chemicals. Recently, solid Lewis acids have been shown to perform catalytic reactions with carbonyl-containing molecules such as sugars in aqueous media. Here, catalysis mediated by Lewis acids is briefly discussed, Lewis acid solids that perform catalysis in aqueous media are then described, and the review is concluded with a few comments on the outlook for the future.
A phantom menace? Cosmological consequences of a dark energy component with super-negative equation of state

Abstract It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused attention on cosmological models in which the dominant component of the cosmic energy density has negative pressure, with an equation of state w⩾−1. Remarking that most observations are consistent with models right up to the w=−1 or cosmological constant (Λ) limit, it is natural to ask what lies on the other side, at w
XMM-NEWTON DISCOVERY OF 217 s PULSATIONS IN THE BRIGHTEST PERSISTENT SUPERSOFT X-RAY SOURCE IN M31

We report on the discovery of a periodic modulation in the bright supersoft X-ray source XMMU J004252.5+411540 detected in the 2000-2004 XMM-Newton observations of M31. The source exhibits X-ray pulsations with a period P ~ 217.7 s and a quasi-sinusoidal pulse shape and pulsed fraction ~7%-11%. We did not detect statistically significant changes in the pulsation period on the timescale of 4 yr. The X-ray spectra of XMMU J004252.5+411540 are extremely soft and can be approximated with an absorbed blackbody of temperature 62-77 eV and a weak power-law tail of photon index Γ ~ 1.7–3.1 in the 0.2-3.0 keV energy band. The X-ray properties of the source and the absence of an optical/UV counterpart brighter than 21 mag suggest that it belongs to M31. The estimated bolometric luminosity of the source varies between ~2 × 1038 and ~8 × 1038 ergs s−1 at 760 kpc, depending on the choice of spectral model. The X-ray pulsations and supersoft spectrum of XMMU J004252.5+411540 imply that it is almost certainly an accreting white dwarf, steadily burning hydrogen-rich material on its surface. We interpret X-ray pulsations as a signature of the strong magnetic field of the rotating white dwarf. Assuming that the X-ray source is powered by disk accretion, we estimate its surface field strength to be in the range 4 × 105 G < B0 < 8 × 106 G. XMMU J004252.5+411540 is the second supersoft X-ray source in M31 showing coherent pulsations, after the transient supersoft source XMMU J004319.4+411758 with an 865.5 s pulsation period.
New contact development for Si(Li) orthogonal-strip detectors

Abstract At present, the contacts generally used for lithium-drifted silicon detectors consist of a diffused lithium layer (n-type) and a gold surface barrier (p-type). These contacts work well for unsegmented detectors. However, they both have disadvantages if used for segmented detectors. For this reason, we are developing new types of contacts that will be more robust and easier to segment. To replace the lithium n-type contact, we are using a thin layer of amorphous silicon (α-Si) with metalization on top. The new p-type contact consists of boron implanted into the silicon and annealed at the relatively low temperature of 500°C. The implantation and annealing is carried out as the first step in the process, prior to lithium drifting. Detectors have been fabricated using the new contacts both with and without a guard ring. They performed as well as detectors with standard contacts at operating temperatures between 80 and 240 K. We will present data on the leakage current vs. temperature, isolation resistance between the guard ring and the center contact versus temperature and bias voltage, electronic noise and energy resolution versus temperature, as well as 57Co spectra.
Self-consistent field model for condensed matter

A model for condensed matter is described in which the ions surrounding a particular atom are replaced by a positive charge distribution which is constant outside of a sphere containing the atom and zero inside. The orbital functions, both bound and free, are obtained as solutions of the Dirac equation and are used to self-consistently determine the potential function. In order to obtain the desired equation-of-state data from the calculations, three different and somewhat arbitrary prescriptions are used to separate quantities pertaining to the atom from those of the electron gas in which it is imbedded. Results are shown for 14 elements, including the $5d$ transition metals, in the neighborhood of normal solid density. Equation-of-state data for nickel, copper, and zinc are also given and are compared with experiment.
MOST 1.6 EARTH-RADIUS PLANETS ARE NOT ROCKY

The Kepler mission, combined with ground-based radial velocity (RV) follow-up and dynamical analyses of transit timing variations, has revolutionized the observational constraints on sub-Neptune-sized planet compositions. The results of an extensive Kepler follow-up program including multiple Doppler measurements for 22 planet-hosting stars more than doubles the population of sub-Neptune-sized transiting planets that have RV mass constraints. This unprecedentedly large and homogeneous sample of planets with both mass and radius constraints opens the possibility of a statistical study of the underlying population of planet compositions. We focus on the intriguing transition between rocky exoplanets (comprised of iron and silicates) and planets with voluminous layers of volatiles (H/He and astrophysical ices). Applying a hierarchical Bayesian statistical approach to the sample of Kepler transiting sub-Neptune planets with Keck RV follow-up, we constrain the fraction of close-in planets (with orbital periods less than ~50 days) that are sufficiently dense to be rocky, as a function of planet radius. We show that the majority of 1.6 R⊕ planets have too low density to be comprised of Fe and silicates alone. At larger radii, the constraints on the fraction of rocky planets are even more stringent. These insights into the size demographics of rocky and volatile-rich planets offer empirical constraints to planet formation theories, and guide the range of planet radii to be considered in studies of the occurrence rate of "Earth-like" planets, η⊕.
Electrophilic coordination catalysis: a summary of previous thought and a new angle of analysis.

One of the most common, and yet least well understood, enzymatic transformations is proton abstraction from activated carbon acids such as carbonyls. Understanding the mechanism for these proton abstractions is basic to a good understanding of enzyme function. Significant controversy has arisen over the means by which a given enzyme might facilitate these deprotonations. Creating small molecule mimics of enzymes and physical organic studies that model enzymes are good approaches to probing mechanistic enzymology. This Account details a number of molecular recognition and physical organic studies, both from our laboratory and others, dealing with the elucidation of this quandary. Our analysis launches from an examination of the active sites and proposed mechanism of several enzyme-catalyzed deprotonations of carbon acids. This analysis highlights the geometries of the hydrogen bonds found at the enzyme active sites. We find evidence to support π-oriented hydrogen bonding, rather than lone pair oriented hyd...
2d index and surface operators

In this paper we compute the superconformal index of 2d (2, 2) supersymmetric gauge theories. The 2d superconformal index, a.k.a. flavored elliptic genus, is computed by a unitary matrix integral much like the matrix integral that computes the 4d superconformal index. We compute the 2d index explicitly for a number of examples. In the case of abelian gauge theories we see that the index is invariant under flop transition and under CY-LG correspondence. The index also provides a powerful check of the Seiberg-type duality for non-abelian gauge theories discovered by Hori and Tong. In the later half of the paper, we study half-BPS surface operators in N = 2 super-conformal gauge theories. They are engineered by coupling the 2d (2, 2) supersymmetric gauge theory living on the support of the surface operator to the 4d N = 2 theory, so that different realizations of the same surface operator with a given Levi type are related by a 2d analogue of the Seiberg duality. The index of this coupled system is computed by using the tools developed in the first half of the paper. The superconformal index in the presence of surface defect is expected to be invariant under generalized S-duality. We demonstrate that it is indeed the case. In doing so the Seiberg-type duality of the 2d theory plays an important role.
BRUECKNER THEORY OF NUCLEAR MATTER WITH NONNUCLEONIC DEGREES OF FREEDOM AND RELATIVITY

For the past 40 years, Brueckner theory has proven to be a most powerful tool to investigate systematically models for nuclear matter. I will give an overview of the work done on nuclear matter theory, starting with the simplest model and proceeding step by step to more sophisticated models by extending the degrees of freedom and including relativity. The final results of a comprehensive hadronic theory of nuclear matter are compared to the predictions by currently fashionable two-nucleon force models. It turns out that a two-nucleon force can, indeed, reproduce those results if the potential is nonlocal, since nonlocality is an inherent quality of the more fundamental field-theoretic approach. This nonlocality is crucial for creating sufficient nuclear binding.
Parallel adaptive decision feedback equalizers

Several algorithms for parallel implementation of adaptive decision feedback equalizers (DFEs) are proposed. The first is a double-row DFE algorithm that outperforms previous approaches. Under the no-error-propagation assumption, the algorithm will perform exactly like a serially adapting DFE. The multiplication complexity of the double-row DFE algorithm is of the same order as that of the parallel DFE algorithm and the extended least-mean-square (LMS) method. The previous algorithms and the double-row DFE algorithm may become impractical to implement due to their large computational complexity, so three additional parallel implementations of the DFE, which lead to considerable hardware savings and avoid the coding loss of the former approaches, are presented. The different algorithms are compared on the basis of convergence analysis and simulation results. >
P(RNCH2CH2)3N : EFFICIENT CATALYSTS FOR TRANSESTERIFICATIONS, ACYLATIONS, AND DEACYLATIONS

Extremely strong nonionic superbases of the type P(RNCH2CH2)3N catalyze the transesterification of carboxylic acid esters with high selectivity and yields at 25 °C. These bases also catalyze the deacetylation of alcohols under mild conditions in quantitative yields. Using enol acetates as acylating agents, primary and secondary alcohols are efficiently protected as acetates through the action of these catalysts. Substituents such as epoxide, carbamate, acetal, oxazoline, nitro, and alkynyl functionalities are tolerated under the reaction conditions. N-Protected peptides undergo clean transesterification without significant racemization, making this methodology potentially very useful.
Consistency of Random Survival Forests

Abstract We prove uniform consistency of Random Survival Forests (RSF), a newly introduced forest ensemble learner for analysis of right-censored survival data. Consistency is proven under general splitting rules, bootstrapping, and random selection of variables—that is, under true implementation of the methodology. Under this setting we show that the forest ensemble survival function converges uniformly to the true population survival function. To prove this result we make one key assumption regarding the feature space: we assume that all variables are factors. Doing so ensures that the feature space has finite cardinality and enables us to exploit counting process theory and the uniform consistency of the Kaplan–Meier survival function.
Alternative polymer supports for organic chemistry.

The use of polymers other than divinylbenzene crosslinked polystyrene as supports in organic chemistry is discussed. Insoluble polymer alternatives to DVB crosslinked polystyrene discussed include porous polyethylene supports, polymer-supported functional colloids, micron and submicron-sized particles and hollow spheres and one-dimensional supports. Soluble polymers including polyethylene, poly(alkene oxide)s, polyacrylamides, and fluorinated acrylates are discussed along with thermomorphic strategies where liquid–liquid separation of a biphasic systems is used as a way to effect polymer recovery in systems that are monophasic on heating. © John Wiley & Sons, Inc. Med Res Rev, 19, No. 5, 439–450, 1999.
Categorifications from planar diagrammatics

A diagrammatic presentation of functors and natural transformations and the virtues of biadjointness are discussed. We then review a graphical description of the category of Soergel bimodules and a diagrammatic categorification of positive halves of quantum groups. These notes are a write-up of Takagi Lectures given by the author in Hokkaido University in June 2009.
Gamma-ray spectroscopy - Status and prospects

Contemporary gamma-ray spectroscopy instruments and their results are reviewed. Sensitivities of 10 to the -4th to 10 to the -3rd ph/sq cm-sec have been achieved for steady sources and 10 to the -2nd to 1 ph/sq cm-sec for transient sources. This has led to the detection of gamma-ray lines from more than 40 objects representing 6 classes of astrophysical phenomena. The lines carry model-independent information and are of fundamental importance to theoretical modeling and our understanding of the objects. The objectives and anticipated results of future instruments are discussed. Several instruments in development will have a factor of 10 sensitivity improvement to certain phenomena over contemporary instruments. A factor of 100 improvement in sensitivity will allow the full potential of gamma-ray spectroscopy to be realized. Instrument concepts which would achieve this with both present and advanced techniques are discussed.
Unsteady Pulsing of Cylinder Wakes

An overview of recent progress in modelling the behavior of low Reynolds number cylinder wakes is presented. The discussion examines ways in which unsteady forcing has been used to test hypotheses and to control the behavior of the wake. hi addition to the review a new method of reducing the wake momentum defect using pulsating jets is demonstrated for flow around a circular cylinder at a Reynolds number of 370. The line of pulsating jets is embedded in the trailing generator of the cylinder. There is no net mass added by the pulsating jets on an average over the cycle, but there is net momentum addition to the flow by the second-order streaming effect. The jets are most effective in modifying the wake when pulsating at twice the Karman shedding frequency. The streaming flow generated by the pulsation suppresses the Karman vortex street and reduces the momentum defect.
A p-adic local monodromy theorem

We produce a canonical filtration for locally free sheaves on an open p-adic annulus equipped with a Frobenius structure. Using this filtration, we deduce a conjecture of Crew on p-adic differential equations, analogous to Grothendieck's local monodromy theorem (also a consequence of results of Andre and of Mebkhout). Namely, given a finite locally free sheaf on an open p-adic annulus with a connection and a compatible Frobenius structure, the module admits a basis over a finite cover of the annulus on which the connection acts via a nilpotent matrix.
Slope streak formation and dust deposition rates on Mars

[1] The Mars Orbiter Camera (MOC) has imaged, sometimes repeatedly, mass movements known as slope streaks, which are abundant in the dust-covered regions on Mars. They are among the few known examples of contemporary surface changes. A survey of 173 collocated image pairs indicates that these features are currently forming at a high rate of ∼7% per existing streak, per Martian year. Either there is a complete turnover within a few decades or the streak population is currently increasing rapidly. Large spatial, as well as possible temporal, variations in the formation rate are obtained from these data. Streaks do not appear to fade over time periods comparable to their inverse formation rate of ∼28 years, as seen by analysis of Viking Orbiter images containing streaks that are still visible in MOC images. Gradual or stochastic variations in dust deposition may be needed to explain observations of changes in the formation rate, and its current imbalance with the fading rate.
Gray-level transformation and Canny edge detection for 3D seismic discontinuity enhancement

In a 3D seismic survey, detecting seismic discontinuities is vital to robust structural and stratigraphic analysis in the subsurface. Previous methods have difficulty highlighting subtle discontinuities from seismic data in cases where the local amplitude variation is of non-zero mean. This study proposes implementing a gray-level transformation and the Canny edge detector for improved imaging of discontinuities. Specifically, the new process transforms seismic signals to be of zero mean and helps amplify subtle discontinuities, leading to an enhanced visualization for structural and stratigraphic details. Applications to various 3D seismic datasets demonstrate that the new algorithm helps better define channels, faults, and fractures than the traditional similarity, amplitude gradient, and semblance attributes. An improved algorithm for extracting 3D seismic discontinuity attribute.Gray-level transformation helps re-characterize subtle seismic features.Implementing Canny edge detector for efficient discontinuity detection.Integrating discontinuity magnitude and azimuth for fracture characterization.
Absolute integral closure in positive characteristic

Let R be a local Noetherian domain of positive characteristic. A theorem of Hochster and Huneke [M. Hochster, C. Huneke, Infinite integral extensions and big Cohen–Macaulay algebras, Ann. of Math. 135 (1992) 53–89] states that if R is excellent, then the absolute integral closure of R is a big Cohen–Macaulay algebra. We prove that if R is the homomorphic image of a Gorenstein local ring, then all the local cohomology (below the dimension) of such a ring maps to zero in a finite extension of the ring. As a result there follow an extension of the original result of Hochster and Huneke to the case in which R is a homomorphic image of a Gorenstein local ring, and a considerably simpler proof of this result in the cases where the assumptions overlap, e.g., for complete Noetherian local domains.
Expedient synthesis of 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones via one-pot aryne acyl-alkylation/condensation

A convenient method is disclosed for the synthesis of both 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from β-ketoesters using a one-pot aryne acyl-alkylation/condensation procedure. When performed in conjunction with a one-step method for the synthesis of the β-ketoester substrates, this method provides a new route to these polyaromatic structures in only two steps from commercially available carboxylic acid starting materials. The utility of this approach is demonstrated in the synthesis of the atropisomeric P,N-ligand, QUINAP.
Judges as Tort Law Un-Makers: Recent California Experience with "New" Torts

Author(s): Sugarman, Stephen D. | Abstract: Part of the DePaul Law School's 1999 Clifford Symposium, this article explores the role of "judges as lawmakers" by examining the tort law decisions of the California Supreme Court for the past 15 years -- the final three years that Chief Justice Rose Bird sat on the court and the twelve years after she was removed from office. The article presents the sea change in tort law thinking, doctrine and results that have taken place over this period of time -- essentially through the abandonment of notions of enterprise liability (Calabresi thinking about cheaper cost avoiders and cheaper loss spreaders). One theme of the article is that whereas the Bird court made new law (in some cases creating what might be termed "new" torts), the new court has "unmade" that law by its change of direction and outright overruling of existing doctrine. A counter-theme is that it was the Bird court that "unmade" tort law (by moving the law from clearer doctrine that was to be decided by judges to vague legal standards to be decided by juries), and it is actually the new court that is "making" tort law (by adopting new rules, or re-introducing old rules, that take decisions away from juries and give them to judges).
Optimum grid-line patterns for concentrator solar cells under nonuniform illumination

Abstract An optimization procedure for obtaining solar cell grid patterns is presented which minimizes the combined power loss from grid resistance, emitter-layer resistance, and grid shading. The approach is specifically tailored to describe concentrator cells by including the possibility of non-uniform illumination and assuming that a low-loss bus bar encircles the cell. The model generated is quasi-one-dimensional, assuming that all relevant cell parameters, including the illumination profile, can be described as functions of a single dimensional variable. Other significant assumptions include independence of the three loss mechanisms, a uniform grid thickness which is limited by the smallest line width present, and a uniform emitter sheet resistance. The resulting expressions can be solved iteratively by computer, though for small cells under uniform illumination an approximate analytical solution is possible.
The Corrosion Behavior of Molybdenum and Hastelloy B in Sulfur and Sodium Polysulfides at 623 K

An experimental study was completed to determine the corrosion behavior of molybdenum and Hastelloy B, a nickel-based alloy with high molybdenum content, in sulfur and sodium polysulfides (Na/sub 2/S/sub 3/,Na/sub 2/S/sub 4/, Na/sub 2/S/sub 5/) at 623 K. In sulfur, molybdenum corrodes very slowly, with a parabolic rate constant of 3.6 x 10/sup -9/ cm s/sup -1/2/. Hastelloy B shows no measurable corrosion after 100h of exposure to sulfur. The corrosion reaction of molybdenum in Na/sub 2/S/sub 3/ is characterized by the formation of a protective film that effectively eliminates further corrosion after the first 100h of exposure. Hastelloy B, however, corrodes rapidly in Na/sub 2/S/sub 3/, with corrosion rates approaching those of pure nickel under the same conditions. After the first 4h of exposure, the kinetics for the corrosion of Hastelloy B in Na/sub 2/S/sub 3/ follows a linear rate law. The scale morphology has multiple spalled layers of NiS/sub 2/, with some crystallites of NiS/sub 2/ appearing on the leading face of the scale and between the individual scale layers. This spalling causes smaller coupons of the Hastelloy B to corrode faster than larger coupons.
Stereoselective cyclomagnesiation of 1,6-heptadienes catalyzed by zirconocenes: Effects of substituents, solvent and magnesium reagents

Abstract Zirconocene dichloride acts as a catalyst precursor for the stereoselective cyclomagnesiation of an array of substituted 1,6-heptadienes in the presence of butylmagnesium chloride to form trans 1,2-(bis)methylmagnesium substituted carbocycles.
Anomalous momentum diffusion in the classical kicked rotor

Abstract Numerical simulation for the classical kicked rotor is used to obtain the momentum diffusion over a region of the control parameters K from 0 to 100 that covers 15 fundamental accelerator modes. The numerical data for momentum diffusion is well fit by a power law DNβ in the number of kicks N. In the anomalous momentum diffusion regions due to accelerator modes the exponent β(K) is slightly less than quadratic except for a slight dip, in agreement with the upper bound (K2/2)N2. The corresponding coefficient D(K) in these regions has three distinct sections, most likely due to accelerator modes with period greater than one.
Do I Follow My Friends or the Crowd? Information Cascades in Online Movie Ratings

Online product ratings are widely available on the Internet and are known to influence prospective buyers. An emerging literature has started to look at how ratings are generated and, in particular, how they are influenced by prior ratings. We study the social influence of prior ratings and, in particular, investigate any differential impact of prior ratings by strangers "crowd" versus friends. We find evidence of both herding and differentiation behavior in crowd ratings wherein users' ratings are influenced positively or negatively by prior ratings depending on movie popularity. In contrast, friends' ratings always induce herding. Further, the presence of social networking reduces the likelihood of herding on prior ratings by the crowd. Finally, we find that an increase in the number of friends who can potentially observe a user's rating "audience size" has a positive impact on ratings. These findings raise questions about the reliability of ratings as unbiased indicators of quality and advocate the need for techniques to debias rating systems. This paper was accepted by Sandra Slaughter, information systems.
Rapamycin has a biphasic effect on insulin sensitivity in C2C12 myotubes due to sequential disruption of mTORC1 and mTORC2

Rapamycin, an inhibitor of mTOR complex 1 (mTORC1), improves insulin sensitivity in acute studies in vitro and in vivo by disrupting a negative feedback loop mediated by S6 kinase. We find that rapamycin has a clear biphasic effect on insulin sensitivity in C2C12 myotubes, with enhanced responsiveness during the first hour that declines to almost complete insulin resistance by 24-48 h. We and others have recently observed that chronic rapamycin treatment induces insulin resistance in rodents, at least in part due to disruption of mTORC2, an mTOR-containing complex that is not acutely sensitive to the drug. Chronic rapamycin treatment may also impair insulin action via the inhibition of mTORC1-dependent mitochondrial biogenesis and activity, which could result in a buildup of lipid intermediates that are known to trigger insulin resistance. We confirmed that rapamycin inhibits expression of PGC-1α, a key mitochondrial transcription factor, and acutely reduces respiration rate in myotubes. However, rapamycin did not stimulate phosphorylation of PKCθ, a central mediator of lipid-induced insulin resistance. Instead, we found dramatic disruption of mTORC2, which coincided with the onset of insulin resistance. Selective inhibition of mTORC1 or mTORC2 by shRNA-mediated knockdown of specific components (Raptor and Rictor, respectively) confirmed that mitochondrial effects of rapamycin are mTORC1-dependent, whereas insulin resistance was recapitulated only by knockdown of mTORC2. Thus, mTORC2 disruption, rather than inhibition of mitochondria, causes insulin resistance in rapamycin-treated myotubes, and this system may serve as a useful model to understand the effects of rapamycin on mTOR signaling in vivo.
The vinylogous aldol reaction of unsaturated esters and enolizable aldehydes using the novel Lewis acid aluminum tris(2,6-di-2-naphthylphenoxide).

The synthesis of the novel Lewis acid, aluminum tris(2,6-di-2-naphthylphenoxide) (ATNP), and its use in the vinylogous aldol reaction between methyl crotonate and enolizable aldehydes are described. ATNP is related to Yamamoto’s Lewis acid, aluminum tris(2,6-diphenylphenoxide) (ATPH), but the 2-naphthyl groups more effectively block the α-position of aldehydes, enabling the selective enolization of crotonate esters in the presence of enolizable aldehydes. Vinylogous aldol reactions then proceed smoothly and in high yields with a variety of substrates.
Quantum Hall states of high symmetry

We identify some hidden symmetries of Chern-Simons theories, such as appear in the effective theory for quantized Hall states. This allows us to determine which filling fractions admit spin-singlet quantum Hall states. Our results shed some light on states already observed at ν = 23, and transitions between them. We identify SU(2), or higher, symmetries of many additional states — including spin-polarized states. Our symmetries classify low-lying excited states and may be of use in the construction of trial wavefunctions, but are typically not present in the edge theory, where they are lifted by non-universal couplings.
Accurate Calorimetry of GRB 030329

We report late-time observations of the radio afterglow of GRB 030329. The light curves show a clear achromatic flattening at 50 days after the explosion. We interpret this flattening as resulting from the blast wave becoming transrelativistic. Modeling of this transition enables us to make estimates of the energy content of the burst, regardless of the initial jet structure or the distribution of initial Lorentz factors of the ejecta. We find, in accordance with other events, that GRB 030329 is well described by an explosion with total energy of a few × 1051 ergs expanding into a circumburst medium with a density of order unity.
Black holes and the butterfly effect

We use holography to study sensitive dependence on initial conditions in strongly coupled field theories. Specifically, we mildly perturb a thermofield double state by adding a small number of quanta on one side. If these quanta are released a scrambling time in the past, they destroy the local two-sided correlations present in the unperturbed state. The corresponding bulk geometry is a two-sided AdS black hole, and the key effect is the blueshift of the early infalling quanta relative to the t = 0 slice, creating a shock wave. We comment on string- and Planck-scale corrections to this setup, and discuss points that may be relevant to the firewall controversy.
Abundances and Depletions of Interstellar Oxygen

We report on the abundance of interstellar neutral oxygen (O I) for 26 sight lines, using data from the Far Ultraviolet Spectroscopic Explorer, the International Spectroscopic Explorer, and the Hubble Space Telescope. O I column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines and subsequently fitting those to a curve of growth. We consider both our general sample of 26 sight lines and a more restrictive sample of 10 sight lines that utilize HST data for a measurement of the weak 1355 A line of oxygen and are thus better constrained owing to our sampling of all three sections of the curve of growth. The column densities of our HST sample show ratios of O/H that agree with the current best solar value if dust is considered, with the possible exception of one sight line (HD 37903). We note some very limited evidence in the HST sample for trends of increasing depletion with respect to RV and f(H2), but the trends are not conclusive. Unlike a recent result from Cartledge et al., we do not see evidence for increasing depletion with respect to nH, but our HST sample contains only two points more dense than the critical density determined in that paper. The column densities of our more general sample show some scatter in O/H, but most agree with the solar value to within errors. We discuss these results in the context of establishing the best method for determining interstellar abundances, the unresolved question of the best value for O/H in the interstellar medium, the O/H ratios observed in Galactic stars, and the depletion of gas-phase oxygen onto dust grains.
Correlation between Raman scattering and conductance in a molecular junction

Using a generic model of a current-carrying molecular junction we discuss, for the first time, correlations between Raman flux and electrical conductance. A mechanism alternative to molecular motion is proposed for these experimentally detected correlations. Numerical simulations based on realistic estimates of molecular junction parameters suggest that the effect should be observable.