cssi/SciSciGPT-SciSciNet huggingface dataset:
Lewis acid-catalyzed intramolecular condensation of ynol ether-acetals. Synthesis of alkoxycycloalkene carboxylates

Treatment of ynol ether-tethered dialkyl acetals with catalytic quantities of scandium triflate in CH3CN gives rise to five-, six-, and seven-membered alkoxycycloalkene carboxylates in good to excellent yields. Tri- and tetrasubstituted carbocyclic and heterocyclic alkenes may be formed by this method, and the products obtained may serve as useful intermediates for natural product synthesis.
Neutrons and nuclear structure

Synopsis In the past few years slow neutron spectrometers of greatly improved resolving power have been developed at many laboratories throughout the world. During the same period advances in techniques of data analysis have aided in producing the information now available on hundreds of neutron resonances. The manner in which the parameters of these resonances give valuable information on nuclear structure will be described. The experimental findings will be reviewed and particular emphasis paid to their bearing on current theoretical nuclear models. The following aspects will be emphasized. 1) The radiation widths of nuclear energy levels and their relationship to theoretical transition probabilities. 2) The size distributions of neutron widths of levels and recent theoretical treatments of these distributions. 3) The average spacings of levels for different nuclei as well as the apparent non-random distribution of spacings for individual nuclei. 4) The probability of compound nucleus formation, or strength function, compared to recent calculations based on the cloudy crystal nuclear model. 5) Recent determinations of the nuclear radius at high and low neutron energies.
Stereoselectivities of thermal and Lewis acid catalyzed intramolecular Diels-Alder reactions of internally activated dienophiles to form 5–11 membered rings

Abstract The thermal and Lewis acid catalyzed intramolecular Diels-Alder reactions of 1 (n = 5–11) have been studied. The catalyzed reactions efficiently form 7–11 membered rings and produce mainly cis adducts. Lewis acids prevent the five-membered ring forming reaction.
Borrower Mobility, Adverse Selection, and Mortgage Points

Abstract This paper analyzes a simple mobility-based model of mortgage lending and uses the results to illuminate the issue of mortgage points. The model predicts the points/interest-rate trade-off observed in the market, and it also predicts that mobile borrowers choose low-points/high-rate contracts from the available menu, in conformance with conventional wisdom. These outcomes are shown to be a result of adverse selection, which arises because of the lender′s inability to distinguish the mobility characteristics of borrowers. Empirical evidence is also presented showing the presence of a points/interest-rate trade-off in the market. In addition, relying on a proxy variable, the results establish that borrowers choose contracts from this menu according to mobility. Journal of Economic Literature Classification Numbers: G21.
Model-Based segmentation featuring simultaneous segment-level variable selection

Abstract The authors propose a new Bayesian latent structure regression model with variable selection to solve various commonly encountered marketing problems related to market segmentation and heterogeneity. The proposed procedure simultaneously performs segmentation and regression analysis within the derived segments, in addition to determining the optimal subset of independent variables per derived segment. The authors present comparative analyses contrasting the performance of the proposed methodology against standard latent class regression and traditional Bayesian finite mixture regression. They demonstrate that their proposed Bayesian model compares favorably with these traditional benchmark models. They then present an actual commercial customer satisfaction study performed for an electric utility company in the southeastern United States, in which they examine the heterogeneous drivers of perceived quality. Finally, they discuss limitations of the research and provide several directions for furth...
Image models in pattern theory

Abstract The pattern theory developed by U. Grenander provides a unified framework for the description of observed images in terms of algebraic and probabilistic processes that generate the images. The main elements of the general theory are outlined and specific image models are related to the general theory.
The number and metallicities of the most metal-poor stars

Simple, one-zone models for inhomogeneous chemical evolution of the Galactic halo are used to predict the number fraction of zero-metallicity, Population III stars, which currently is empirically estimated at <4 × 10−4. These analytic models minimize the number of free parameters, highlighting the most fundamental constraints on halo evolution. There are disagreements of at least an order of magnitude between observations and predictions in limiting cases for both the homogeneous Simple Model and Simple Inhomogeneous Model (SIM). Hence, this demonstrates a quantitative, unambiguous discrepancy in the observed and expected fraction of Population III stars. We explore how the metallicity distribution of the parent enrichment events drives the SIM and predictions for the Population III fraction. The SIM shows that the previously identified ‘high-halo’ and ‘low-halo’ populations are consistent with a continuous evolutionary progression, and therefore may not necessarily be physically distinct populations. Possible evolutionary scenarios for halo evolution are discussed within the simplistic one-zone paradigm of the SIM. The values of z0 depend strongly on metal dispersal processes, thus we investigate interstellar mixing and mass transport, for the first time explicitly incorporating this into a semi-analytic chemical evolution model. Diffusion is found to be inefficient for all phases, including the hot phase, of the interstellar medium (ISM): relevant diffusion lengths are two to four orders of magnitude smaller than corresponding length-scales for turbulent mixing. Rough relations for dispersal processes are given for multiphase ISM. These suggest that the expected low-metallicity threshold above zero is consistent with the currently observed limit.
Mapping the Shores of the Brown Dwarf Desert. I. Upper Scorpius

We present the results of a survey for stellar and substellar companions to 82 young stars in the nearby OB association Upper Scorpius. This survey used nonredundant aperture mask interferometry to achieve typical contrast limits of ΔK ~5-6 at the diffraction limit, revealing 12 new binary companions that lay below the detection limits of traditional high-resolution imaging; we also summarize a complementary snapshot imaging survey that discovered seven directly resolved companions. The overall frequency of binary companions (~35 +5 -4% at separations of 6-435 AU) appears to be equivalent to field stars of similar mass, but companions could be more common among lower mass stars than for the field. The companion mass function has statistically significant differences compared to several suggested mass functions for the field, and we suggest an alternate lognormal parameterization of the mass function. Our survey limits encompass the entire brown dwarf mass range, but we only detected a single companion that might be a brown dwarf; this deficit resembles the so-called brown dwarf desert that has been observed by radial velocity planet searches. Finally, our survey’s deep detection limits extend into the top of the planetary mass function, reaching 8-12 MJup for half of our sample. We have not identified any planetary companions at high confidence (≳99.5%), but we have identified four candidate companions at lower confidence (≳97.5%) that merit additional follow-up to confirm or disprove their existence.
A Disposable Liquid Microcell for Near-Infrared Reflectance Analysis:

While near-infrared reflectance instruments are best known for their ability to rapidly analyze powdered solid samples, some manufacturers have provided the means to measure liquid samples as well. Unfortunately, liquid-analysis accessories are often cumbersome and expensive. A typical accessory requires a relatively large volume of the sample (on the order of milliliters) and complex purge/fill and wash cycles to prevent clogging. If clogging does occur, cleaning can be difficult. The thermostatically controlled heating cycle only adds to a total analysis time already extended by the other operations.
Site-specific preparation of 2-carboalkoxy-4-substituted naphthalenes and 9-alkylphenanthrenes and evidence for an allene intermediate in the novel base-catalyzed cyclization of 2-alkynylbiphenyls.

A site-specific preparation of 2-carboalkoxy-4-substituted naphthalenes and 9-alkylphenanthrenes is described. The successful cyclization of an allene intermediate provides supportive evidence for the previously proposed mechanism.
Interdependence: Myth or Reality

One of the uncertainties of modern international relations is the degree of interdependence among states. Some theorists have asserted that interdependence is high and/or growing, and others have maintained that it is low and/or declining. Essentially, the debate about interdependence has proceeded in three separate phases, (i) In the aftermath of World War II, technology was heralded as the stimulus to an interrelationship among states: The world was shrinking; technological, military, and economic factors would produce interdependence even among erstwhile enemies. (2) Later this conventional wisdom was challenged by Karl Deutsch and his associates, who purported to show that various economic indicators of external reference were declining. International transactions were lessening relative to intranational transactions. More and more, citizens were turning to the nation-state for the satisfaction of their needs, and national economies were taking precedence over the previous international economy of the nineteenth century. This theme has recently been powerfully reinforced by Kenneth Waltz. (3) In reaction to the claims of the Deutsch group, which initially predicted stalemate in European unification efforts and a greater autarchy for industrial states, new presentations of the argument in favor of interdependence have been made. According to this view, interdependence among states is certainly increasing. A symposium on the international corporation partly reinforces Deutsch's view, while one on transnational processes argues against it. The resultant of these theoretical vectors remains uncertain. In this essay we hope to offer new data and to provide a modest reconciliation of the contending claims, drawing a trial balance between them.
Fiscal flows in the United States and Canada: Lessons for monetary union in Europe

Regional flows of federal taxes and transfers within the United States and Canada are used to analyze long-term fiscal flows (the redistributive element) and short-term responses to regional business cycles (the stabilization element). In the United States, long-run flows amount to 22 cents in the dollar while the stabilization effect is 31 cents in the dollar. In Canada the redistributive effect is larger (39 cents) and the stabilization effect smaller (17 cents). Federal flows appears to depend on the institutional structure of the country concerned; however, in both countries the redistributive element is considerably larger than the amounts involved in the EC Structural Funds program. As for stabilization, national fiscal policies in the EC appear to have been as effective as federal governments in the United States and Canada in cushioning shocks to incomes.
IMPAIRMENT OF THE LYMPHOCYTE RESPONSE TO PHYTOHAEMAGGLUTININ IN CHICKENS WITH MAREK'S DISEASE

Spleen lymphoid cells obtained from White Leghorn chickens with Marek's disease exhibited a significantly impaired proliferative response to the mitogen phytohaemagglutinin (PHA) as measured by the incorporation of tritiated thymidine. While chickens infected by the intraperitoneal inoculation of infectious blood on the day of hatching still were able to mount a small PHA response, their contact-infected pen mates completely failed to respond. Lymphoid tumour cells from the gonads of inoculated chickens with Marek's disease were not stimulated by PHA. Rather, a suppressive effect of PHA on these cells was noted.
Free radical generation by reduction of ketone tosylhydrazones

Abstract Alkyl radicals are conveniently generated from ketones by reduction of the derived tosylhydrazones. The alkyl radicals undergo efficient intramolecular cyclization to give the thermodynamically less stable cis-1,2-dialkylcyclopentane derivatives.
Scanning light spot analysis of faulty solar cells

Abstract Current output patterns of a solar cell panel exposed to a scanning light spot are computed for fault-free and for faulty cell containing either cracks with leakage conductances across the exposed junction at the crack, or point shorts in series with various spreading resistances. Low light level, uniform attenuation length, and an external panel termination of low impedance are assumed. It is shown that various boundary conditions can be satisfied by appropriate imaging techniques. A general equivalency theorem for the cell output of an illuminated point with that of an illuminated line through that point parallel to the finger electrode is derived and utilized. The preferred attenuation length of about half the finger electrode spacing can be achieved by modulating the light beam at an appropriate frequency which is typically in the low MHz range. Output patterns generated by a modulated light beam are compared with those obtained by unmodulated light.
Zodiac: a history-based interactive video authoring system

Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition, by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing. Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer management all exploit the edit history information for performance optimization.
Emission-Line Diagnostics of the Central Engines of Weak-Line Radio Galaxies

A handful of well-studied weak-line radio galaxies (WLRGs) have been traditionally classified as low-ionization nuclear emission-line regions (LINERs), suggesting that these two groups of active galactic nuclei (AGNs) might be related. In this paper, we present new optical emission-line measurements for 20 WLRGs, which we supplement with measurements for an additional four from the literature. Classifying these objects by their emission-line ratios, we find that 50% of the objects are robustly classified as LINERs, while an additional 25% are likely to be LINERs. Photoionization calculations show that the spectral energy distribution of the well-studied WLRG 3C 270 (NGC 4261) is able to produce the observed emission-line ratios, but only if the UV emission seen by the narrow emission line gas is significantly higher than that observed, implying AV = 2.5-4.2 mag along our line of sight to the nucleus. From the photoionization calculations, we find that the emission-line gas must have an ionization parameter between 10-3.5 and 10-4.0 and a wide range in hydrogen density (102-106 cm-3) to reproduce the measured emission-line ratios, similar to the properties inferred for the emission-line gas in LINERs. Thus, we find that properties of the emission-line gas as well as the underlying excitation mechanism are indeed similar in LINERs and WLRGs. By extension, the central engines of accretion-powered LINERs and WLRGs, which do host an accreting black hole, may be qualitatively similar.
Intercomparison Between Independent Irradiance Scales Based On Silicon Photodiode Physics, Gold-Point Blackbody Radiation, And Synchrotron Radiation

An intercomparison has been conducted among three independent scales of spectral irradiance: two source-based and one detector-based. Specifically, a radiometer composed of a silicon photodiode, an interference filter, and an integrating sphere was characterized and calibrated against an absolute silicon detector standard at 600 nm using a cw dye laser. This radiometer was then used to measure the spectral irradiance at 600 nm from spectral irradiance lamps calibrated against a gold-point blackbody, and the spectral irradiance at the same wavelength from the NBS electron storage ring, SURF-II. Intercomparisons of this type are an important check of the agreement between these independent radiometric techniques. It was found that the detector scale indicated a spectral irradiance at 600 nm that was 0.76% lower than predicted by the gold-point blackbody scale and 0.25% higher than predicted by the electron storage ring scale. This result implies agreement within the overall quadrature uncertainties of ±0.25% for the detector scale, ±0.84% for the gold-point blackbody scale, and ±0.60% for the electron storage ring scale.
Bayesian Reliability Based Design Optimization Using Eigenvector Dimension Reduction (EDR) Method

In practical engineering design, most data sets for system uncertainties are insufficiently sampled from un- known statistical distributions, known as epistemic uncer- tainty. Existing methods in uncertainty-based design optimization have difficulty in handling both aleatory and epistemic uncertainties. To tackle design problems engaging both epistemic and aleatory uncertainties, reliability-based design optimization (RBDO) is integrated with Bayes theorem. It is referred to as Bayesian RBDO. However, Bayesian RBDO becomes extremely expensive when employing the first- or second-order reliability method (FORM/SORM) for reliability predictions. Thus, this paper proposes development of Bayesian RBDO methodology and its integration to a numerical solver, the eigenvector dimension reduction (EDR) method, for Bayesian reliabil- ity analysis. The EDR method takes a sensitivity-free approach for reliability analysis so that it is very efficient and accurate compared with other reliability methods such as FORM/SORM. Efficiency and accuracy of the Bayesian RBDO process are substantially improved after this integration.
Local Moments and Localized States

What mathematical difficulty it contained has been almost fully- cleared up within the past few years. Localization was a different matter: very few believed it at the time, and even fewer saw its importance; among those who failed to fully understand it at first was certainly its author. It has yet to receive adequate mathematical treatment, and one has to resort to the indignity of numerical simulations to settle even the simplest questions about it. Only now, and through primarily Sir Nevill Mott’s efforts, is it beginning to gain general acceptance. Yet these two finally successful brainchildren have also much in common: first, they flew in the face of the overwhelming ascendancy. at the time of the band theory of solids, in emphasizing locality : how a magnetic moment, or an eigenstate, could be permanently pinned down in a given region. It is this fascination with the local and with the failures, not successes, of band theory, which the three of us here seem to have in common. Second, the two ideas were born in response to a clear experimental signal which contradicted the assumptions of the time; third, they intertwine my work with that of my two great colleagues with whom I have been jointly honored; and fourth, both subjects are still extremely active in 1977.
Nanofluidic tuning of photonic crystal circuits

By integrating soft-lithography-based nanofluidics with silicon nanophotonics, we demonstrate dynamic, liquid-based addressing and high Delta n/n(~0.1) refractive index modulation of individual features within photonic structures at subwavelength length scales. We show ultracompact tunable spectral filtering through nanofluidic targeting of a single row of holes within a planar photonic crystal. We accomplished this with an optofluidic integration architecture comprising a nanophotonic layer, a nanofluidic delivery structure, and a microfluidic control engine. Variants of this technique could enable dynamic reconfiguration of photonic circuits, selective introduction of optical nonlinearities, or delivery of single molecules into resonant cavities for biodetection.
The Performance of an Inverter Having AC Switched Commutation

A voltage-fed thyristor inverter in which the commutating circuit contains a pair of auxiliary thyristors in an ac switch connection is presented. Operation of the circuit is investigated by computer-aided analysis and performance calculation, leading to selection of design conditions. The results are compared with another type of commutating circuit. Overall, the features of this circuit may or may not be advantageous, depending on the particular application.
The structure of fac-Ce(OAsPh3)3Cl3•CH3CN and Ce(OAsPh3)3(NO3)3: evidence for a structural trans influence

Abstract Ce(OAsPh3)3Cl3·CH3CN, P 1 , with cell parameters a = 11.614(1), b = 12.009(2) and c = 20.991(3) A, α = 89.08(1), β = 88.50(1), γ = 64.40°(2), and Z = 2. Refinement of 320 parameters for 4710 reflections converged to R = 0.052 and RW = 0.067. This is the first example of a Ln(III) chloride complex with octahedral coordination in which bulky triphenylarsenic oxide substituents are in a facial conformation. The CeO distance is shorter and the CeCl distance is longer than expected and suggests that a structural trans influence dictates the conformation of the first coordination sphere. Ce(OAsPh3)3(NO3)3, P21,/n, with cell parameters a = 15.14(2), b = 21.31(3), c = 17.81(1) A, β = 92.30°(4) and Z = 4. The cyrstals were of poor quality, but the structure is of sufficient accuracy to determine that the complex is facial based on octahedral coordination. Refinement of 313 parameters on 4070 reflections converged to R = 0.115 and RW = 0.138.
Timescales of Land Surface Evapotranspiration Response.

Abstract Soil and vegetation exert strong control over the evapotranspiration rate, which couples the land surface water and energy balances. A method is presented to quantify the timescale of this surface control using daily general circulation model (GCM) simulation values of evapotranspiration and precipitation. By equating the time history of evaporation efficiency (ratio of actual to potential evapotranspiration) to the convolution of precipitation and a unit kernel (temporal weighting function), response functions are generated that can be used to characterize the timescales of evapotranspiration response for the land surface model (LSM) component of GCMs. The technique is applied to the output of two multiyear simulations of a GCM, one using a Surface-Vegetation-Atmosphere-Transfer (SVAT) scheme and the other a Bucket LSM. The derived response functions show that the Bucket LSM’s response is significantly slower than that of the SVAT across the globe. The analysis also shows how the timescales of i...
Determination of acyclovir in maternal plasma, amniotic fluid, fetal and placental tissues by high-performance liquid chromatography.

Acyclovir [9-[(2-hydroxyethoxy)-methyl]-guanosine, Zovirax, ACV] is a synthetic purine nucleoside analog active against herpes simplex virus types 1 (HSV-1), 2 (HSV-2), and varicella zoster virus. Acyclovir has frequently been used in HSV-2 seropositive mothers to prevent prenatal transmission of herpes virus to their unborn children. A fast and reproducible HPLC method for the determination of the highly polar acyclvoir in maternal rat plasma, amniotic fluid, placental tissue, and fetal tissue has been developed and validated. Plasma and amniotic fluid samples were prepared by protein precipitation using 2 M perchloric acid and syringe filtering. Tissue samples were homogenized in distilled water, centrifuged, and extracted using a C(18) solid-phase extraction method prior to analysis. Baseline resolution was achieved for acyclovir and the internal standard gancyclovir, an anti-viral of similar structure to acyclovir, using an Agilent Eclipse XDB C(8) column (150 x 2.1 mm, 5 microm). The mobile phase used for the plasma and amniotic fluid was 10 mM acetate/citrate buffer-3.7 mM aqueous octanesulfonic acid (87.5:12.5, v/v) at a flow-rate of 0.2 ml/min. The mobile phase used for the tissue samples was 30 mM acetate/citrate buffer with 5 mM octanesulfonic acid-acetonitrile (99:1, v/v). Both aqueous mobile phase portions were pH adjusted to 3.08. All separations were done using an Agilent 1100 Series HPLC system with UV detection of 254 nm. The assay was validated for each matrix over a range of 0.25-100 microg/ml over 3 days using five replicates of three spiked concentrations. The relative standard deviation and percent error for each validation data set was 0.99. The extraction efficiency for recovery of acyclovir from all matrices was >80%.
On the independence of Heegner points associated to distinct quadratic imaginary fields

Let E/Q be an elliptic curve with no CM and a fixed modular parametrization ΦE:X0(N)→E and let P1,…,Pr∈E(Q¯) be Heegner points attached to the rings of integers of distinct quadratic imaginary fields k1,…,kr. We prove that if the odd parts of the class numbers of k1,…,kr are larger than a constant C=C(E,ΦE) depending only on E and ΦE, then the points P1,…,Pr are independent in E(Q¯)/Etors.
A Method for Obtaining Aerodynamic Coefficients from Yawsonde and Radar Data

Abstract : A numerical integration method for the reduction of yawsonde data from instrumented projectiles in free flight has been developed. Yawsonde data represent two-dimensional information (solar aspect angle and spin) while the actual motion is three-dimensional (pitch, yaw, and spin). The method obtains a best fit of the aerodynamic coefficients in the equations of motion using numerical integration. The coefficients are iteratively adjusted. Linear aerodynamic coefficients have been derived from the flight of an M549, 155mm rocket assisted projectile.
Ring Opening of Cyclic Vinylogous Acyl Triflates Using Stabilized Carbanion Nucleophiles: Claisen Condensation Linked to Carbon−Carbon Bond Cleavage

Addition of stabilized carbanionic nucleophiles to cyclic vinylogous acyl triflates (VATs) triggers a ring-opening fragmentation to give acyclic β-keto ester and related products, much like those observed traditionally in the Claisen condensation. Unlike in the classical Claisen condensation, however, the VAT-Claisen reaction described herein is rendered irreversible by C−C bond cleavage, not by deprotonation of the activated methylene product. Full details of this original reaction methodology are disclosed herein, including how subtle differences between the various nucleophiles impact the proper choice of reaction conditions for making 1,3-diketones, β-keto esters, and β-keto phosphonates.
On the Cut Number of a 3{manifold

The question was raised as to whether the cut number of a 3{manifold X is bounded from below by 11 (X). We show that the answer to this question is \no." For each m 1, we construct explicit examples of closed 3{manifolds X with 1 (X )= mand cut number 1. That is, 1 (X) cannot map onto any non-abelian free group. Moreover, we show that these examples can be assumed to be hyperbolic.
Asymmetric Alkyl−Alkyl Cross-Couplings of Unactivated Secondary Alkyl Electrophiles: Stereoconvergent Suzuki Reactions of Racemic Acylated Halohydrins

A method for asymmetric alkyl−alkyl Suzuki reactions of unactivated secondary alkyl electrophiles, specifically, cross-couplings of racemic acylated halohydrins with alkylborane reagents, has been developed. A range of protected bromohydrins, as well as a protected chlorohydrin and a homologated bromohydrin, are coupled in good ee by a catalyst derived from commercially available components.
The Godel-Schrodinger Spacetime and Stringy Chronology Protection

We show that the null Melvin map applied to a rotational isometry of global anti-de Sitter space produces a spacetime with properties analogous to both the Godel and Schrodinger geometries. The isometry group of this Godel-Schrodinger spacetime is appropriate to provide a holographic dual for the same non-relativistic conformal theory as the ordinary Schrodinger geometry, but defined on a sphere. This spacetime also possesses closed timelike curves outside a certain critical radius. We show that a holographic preferred screen for an observer at the origin sits at an interior radius, suggesting that a holographic dual description would only require the chronologically consistent region. Additionally, giant graviton probe branes experience repulson-type instabilities in the acausal region, suggesting a condensation of branes will modify the pathological part of the geometry to remove the closed timelike curves.
An optimal auction perspective on lobbying

The lobbying process has been described as an auction (see, for instance, Bernheim and Whinston [4]). While the auction rules picked are supposed to be descriptive, they vary from author to author. Examples show that these different auction rules make different predictions of what policy is the outcome of the lobbying process. Further, which proposed auction rule is the most preferred by the government official depends on the preferences of lobbies.¶ If off-the-equilibrium negative contributions (i.e., contributions from the government official to lobbies) are possible, there is a best possible auction for the government official. Such an auction leads to the same policy as in [4], although contributions are higher. If negative contributions are not possible, the government official is made worse off. It follows that since the auction rules used in the literature to describe lobbying do not allow negative contributions, none of them are optimal from the government official's perspective.
Multidecadal variability in East African hydroclimate controlled by the Indian Ocean

The recent decades-long decline in East African rainfall suggests that multidecadal variability is an important component of the climate of this vulnerable region. Prior work based on analysing the instrumental record implicates both Indian and Pacific ocean sea surface temperatures (SSTs) as possible drivers of East African multidecadal climate variability, but the short length of the instrumental record precludes a full elucidation of the underlying physical mechanisms. Here we show that on timescales beyond the decadal, the Indian Ocean drives East African rainfall variability by altering the local Walker circulation, whereas the influence of the Pacific Ocean is minimal. Our results, based on proxy indicators of relative moisture balance for the past millennium paired with long control simulations from coupled climate models, reveal that moist conditions in coastal East Africa are associated with cool SSTs (and related descending circulation) in the eastern Indian Ocean and ascending circulation over East Africa. The most prominent event identified in the proxy record--a coastal pluvial from 1680 to 1765--occurred when Indo-Pacific warm pool SSTs reached their minimum values of the past millennium. Taken together, the proxy and model evidence suggests that Indian Ocean SSTs are the primary influence on East African rainfall over multidecadal and perhaps longer timescales.
The Bar Examination and the Dream Deferred: A Critical Analysis of the MBE, Social Closure, and Racial and Ethnic Stratification

In this article, the author applies social closure theory to help explain why more than a dozen states have recently enacted more stringent bar exam passing standards and why others are considering similar changes. While higher standards are usually advocated as a way to protect the public from lower student “quality,” the author applies social closure theory and argues that changes in passing standards are a response to a perceived oversupply of lawyers, especially among solo practitioners. In the 1990s, crowding among solo practitioners reached record levels, and real earnings eroded substantially. The author then links this labor market analysis to a critical examination of the knowledge claims that justify the bar exam to the legal profession and the public at large. The article's conclusion is that the psychometric research sponsored by the National Conference of Bar Examiners consistently minimizes and obscures the disparate impact and unfairness of the bar exam for people of color.
The Total Synthesis of Spirotryprostatin A.

Eight concise steps suffice for the first total synthesis of the title compound 1, which inhibits the transitions from the G2 and M phases into the next phases of the cell cycle. Key steps in the synthesis are a stereocontrolled oxidative rearrangement of an indole to form the chiral spiroindolinone nucleus and a regioselecitve sulfoxide elimination.
Setting the Bridgehead Oxidation Level in trans‐Tricyclo[9.3.1.03,8]pentadecanes as a Prelude to the Dual Synthesis of Taxol and Taxusin

The key elements associated with the synthetic elaboration of functionalized trans-tricyclo-[9.3.1.03,8]pentadecanes carrying either a bridgehead H or OH substituent are detailed. Starting with 12, a ketone available in two steps from (R)-2-oxo-7,7-dimethyl-l-vinylbicyclo[2.2.1]heptane, it proved possible to introduce trans-B/C ring juncture configuration as in 16 in five steps. This advanced intermediate constitutes the point of bifurcation. The pathway to taxusin precursor 23 was attained by stereospecific osmylation, reduction, and pinacol-like 1,2-Wagner-Meerwein rearrangement within acetoxy mesylate 22c. Still more abbreviated is the route to 32, which again takes advantage of the osmylation step but proceeds, forward without reduction of the rear carbonyl group. Once hydroxy diketone 31 is produced, equilibration in the presence of (t-BuO)3Al results in complete conversion to 32. The many stereoselective transformations developed in the course of this study, in combination with the several thermodynamic questions that have been clarified, are expected to be highly serviceable as more advanced thrusts toward taxusin and taxol are mounted.
An evolutionary game theoretic perspective on e-collaboration: The collaboration effort and media relativeness

Abstract Studies of e-collaboration from a game-theoretical perspective are practically nonexistent. This article contributes to filling this gap by focusing on the strategic interaction between players as they decide whether and how much to collaborate with each other. We use evolutionary game theory to make predictions about a two-person e-collaboration game. More specifically, we extend the traditional Prisoners’ Dilemma and Snowdrift game theory notions to discrete-strategy e-collaboration games, by explicitly including social punishments into the players’ payoff functions. We also introduce continuous-strategy e-collaboration games with both complete and incomplete information. Finally, we provide two generic dynamic programming models for e-collaboration games with media selection.
Transformer recharging with alpha channeling in tokamaks

Transformer recharging with lower hybrid waves in tokamaks can give low average auxiliary power if the resistivity is kept high enough during the radio frequency recharging stage. At the same time, operation in the hot ion mode via alpha channeling increases the effective fusion reactivity. This paper addresses the extent to which these two large cost-saving steps are compatible.
Feasibility analysis for the rotordynamic performance of API617

The rotordynamic performance of API 617 standards provides two primary requirements. First, the standard stipulates system damping near the expected operating speed range. Second, the standard requires a specific bound of the worst case unbalance response. The problem this poses for machine designers is (1) feasibility: can bearings be designed for a given rotor to meet API 617 and (2) if so, how can these bearings be designed? Our primary effort in this research is to convert the API requirements to a control design objective for a bearing. This permits direct assessment of the feasible design problem as well as providing a means to synthesize optimal bearing dynamics. In addition to providing synthesis of magnetic bearings, the resulting bearing transfer functions give direct guidance to selection of more conventional fluid film or rolling element bearings.
Quantitative testing of sympathetic function with laser Doppler flowmetry

Objective. The objective of this study was to develop an indirect technique for evaluating dynamic changes in sympathetic function in humans.Methods. We used laser Doppler to monitor sympathetic mediated vasoconstrictive responses (VRs) produced by 3 different provocative stimuli: 4-second inspiratory gasp (IG), ice-water immersion (Ice), and a spring-loaded pin prick (Pin). Skin perfusion on the thenar eminence was continuously monitored in 10 normal subjects (aged 25 to 36 years) using laser Doppler. Ten trials of the 3 stimuli were presented to each subject at 1-minute intervals. We determined the VR, the percent decrease in perfusion produced by each stimulus, and the 2 standard deviation variation in perfusion.Results. No subject found the IG maneuver uncomfortable. In contrast, the Pin and Ice stimuli were reported to be uncomfortable by 8 and 10 subjects, respectively. Five subjects found Pin and Ice stimuli overtly painful. Vasoconstrictive response was 54.1 ± 2.3% (mean ± SEM) with IG, 49.2 ± 2.0% with Ice, and 24.0 ± 1.8% with Pin. Baseline variation was approximately 15% in all trials.Conclusion. Inspiratory gasp vasoconstrictive response (IGVR) is a sensitive indirect technique for evaluating sympathetic efferent function. We observed that the magnitude of the VR elicited by the IG stimuli was similar to that induced by cold water. Unlike the VR induced by Pin or Ice, IGVR is not dependent on noxious input via somatic afferents; therefore, it can be used in patients with diseases that produce a peripheral neuropathy, such as diabetes mellitus. Present uses of this technique and speculation on future uses are presented.
The Florida State University post accelerator progress report

Abstract Since 1980 a Cryogenic Linear Accelerator Booster for the Florida State University Tandem Laboratory has been under design and construction. During this time, a pulsed beam has been developed, building extension have been completed and a “minilinac”, consisting of three resonators has been operated. The design of the four resonator cryostat, that forms the basic unit of the final linac, has been completed. This cryostat is currently under construction. Details will be given of these designs and of the results obtained. Future progress will be described.
Microlensing and the Search for Extraterrestrial Life

Are microlensing searches likely to discover planets that harbor life? Given our present state of knowledge, this is a difficult question to answer. We therefore begin by asking a more narrowly focused question: are conditions on planets discovered via microlensing likely to be similar to those we experience on Earth? In this paper I link the microlensing observations to the well-known "Goldilocks problem" (conditions on the Earth-like planets need to be "just right") to find that Earth-like planets discovered via microlensing are likely to be orbiting stars more luminous than the Sun. This means that light from the planetary system's central star may contribute a significant fraction of the baseline flux relative to the star that is lensed. Such blending of light from the lens with light from the lensed source can, in principle, limit our ability to detect these events. This turns out not to be a significant problem, however. A second consequence of blending is the opportunity to determine the spectral type of the lensed star. This circumstance, plus the possibility that finite-source-size effects are important, implies that some meaningful follow-up observations are likely to be possible for a subset of Earth-like planets discovered via microlensing. In addition, calculations indicate that reasonable requirements on the planet's density and surface gravity imply that the mass of Earth-like planets is likely to be within a factor of ~15 of an Earth mass.
Aromatic iodination using N-iodosaccharin in room temperature ionic liquids

Abstract More reactive iodination conditions have been developed that combine the use of room temperature ionic liquids with N-iodosaccharin. Using these reaction conditions, even very modestly activated arenes such as toluene can be iodinated in good yield under very mild conditions.
Synthesis and chemistry of novel polynitropolycyclic cage molecules

Revue sur la synthese de composes polycycliques, polynitro: tetranitro-1,3,5,7 adamantane, nitro-9 pentacyclo [5.4.0.0 2,6 .0 3,10 .0 5,9 ] undecanedione-8,11, polynitro bis-Homo-1,2cubanes, D 3 -hexanitrotrishomocubane, tetranitro-8,8,11,11 pentacyclo [5.4.0.0 2,6 .0 3,10 .0 5,9 ] undecane, dinitro-1,3 et -1,4 cubane, dinitro-2,3 hexacyclo [5.4.1.0 1,6 .0 3,10 .0 4,8 .0 9,12 ] dodecane, di, tri et tetranitrohexacyclo [5.4.1.0 2,6 .0 3,10 .0 4,8 0 9,12 ] dodecanes
The search for a realistic flipped SU(5) string model

Abstract We present an extensive search for a class of flipped SU(5) models built within the free fermionic formulation of the heterotic string. We describe a set of algorithms which constitute the basis for a computer program capable of generating systematically the massless spectrum and the superpotential of all possible models within the class we consider. Our search through the huge parameter space to be explored is simplified considerably by the constraint of N = 1 spacetime supersymmetry and the need for extra Q, Q representations beyond the standard ones in order to possibly achieve string gauge coupling unification at scales of O(10 18 GeV). Our results are remarkably simple and evidence the large degree of redundancy in this kind of constructions. We find one model with gauge group SU (5)× U (1) Y × SO (10) h × SU (4) h × U (1) 5 and fairly acceptable phenomenological properties. We study the D- and F-flatness constraints and the symmetry breaking pattern in this model and conclude that string gauge coupling unification is quite possible.
Multiple Referrals and Multidimensional Cheap Talk

In previous work on cheap talk, uncertainty has almost always been modeled using a single-dimensional state variable. In this paper we prove that the dimensionality of the uncertain variable has an important qualitative impact on results and yields interesting insights into the "mechanics" of information transmission. Contrary to the unidimensional case, if there is more than one sender, full revelation of information in all states of nature is generically possible, even when the conflict of interest is arbitrarily large. What really matters in transmission of information is the local behavior of senders' indifference curves at the ideal point of the receiver, not the proximity of players' ideal point.
A Novel Interpretation of the Klein-Gordon Equation

The covariant Klein-Gordon equation requires twice the boundary conditions of the Schrodinger equation and does not have an accepted single-particle interpretation. Instead of interpreting its solution as a probability wave determined by an initial boundary condition, this paper considers the possibility that the solutions are determined by both an initial and a final boundary condition. By constructing an invariant joint probability distribution from the size of the solution space, it is shown that the usual measurement probabilities can nearly be recovered in the non-relativistic limit, provided that neither boundary constrains the energy to a precision near ℏ/t 0 (where t 0 is the time duration between the boundary conditions). Otherwise, deviations from standard quantum mechanics are predicted.
Urgent colonoscopy for evaluation and management of acute lower gastrointestinal hemorrhage: a randomized controlled trial.

Urgent Colonoscopy for Evaluation and Management of Acute Lower Gastrointestinal Hemorrhage: A Randomized Controlled Trial
Space charge limited conduction with exponential trap distribution in reduced graphene oxide sheets

We elucidate on the low mobility and charge traps of the chemically reduced graphene oxide (RGO) sheets by measuring and analyzing temperature dependent current-voltage characteristics. The RGO sheets were assembled between source and drain electrodes via dielectrophoresis. At low bias voltage the conduction is Ohmic while at high bias voltage and low temperatures the conduction becomes space charge limited with an exponential distribution of traps. We estimate an average trap density of 1.75×1016 cm−3. Quantitative information about charge traps will help develop optimization strategies of passivating defects in order to fabricate high quality solution processed graphene devices.