cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and 5-HT-3 receptor binding activity of 5-[125I]iodo-2,3-dimethoxy-N-(1-azabicyclo[2.2.2]oct-3-yl)benzamide and its 5-halogen-2-alkoxyl homologues

Summary ( S )-5-Iodo-2,3-dimethoxy- N -(1-azabicyclo[2.2.2]oct-3-yl)benzamide (MIZAC) was prepared from 5-iodo-2,3-dimethoxybenzoyl chloride and ( S )-3-aminoquinuclidine. [ 125 I]Iodode-stannylation of its corresponding 5-tri- n -butyltin derivative gave [ 125 I]-MIZAC at 1800 Ci/mmol. Binding of [ 125 I]-MIZAC in rat entorhinal cortex revealed a K D of 1.37 ± 0.21 nM. A series of racemic 2- O -alkyl derivatives of MIZAC were prepared and 5-HT-3 receptor affinities were determined by inhibition of [ 125 I]-MIZAC binding. Optimal affinity for the receptor was obtained with small, electron-withdrawing substituents in the aromatic 5-position and with bulky substituents in the 3-position. [ 125 I]-MIZAC is a selective radioligand useful for in vitro identification of the 5-HT-3 receptor.
Proposed process modifications for dynamic bipolar memory to reduce emitter-base leakage current

One of the requirements of the dynamic bipolar memory cell is low junction leakage currents. Performance considerations, especially those of peripheral circuitry, may require that the memory is fabricated with the process commonly used in the fabrication of high-performance logic circuits, in which As emitters are used, and in which base surface concentrations are high. It is shown here that because of this, devices fabricated with this process have high emitter-to-base leakage current due to a presence of the tunneling component. It is further shown that this tunneling component can be reduced by simple modifications of the performance-oriented process. The experimental data presented here also show the observed changes in device parameters with various process modifications, which can be helpful in drawing a balance between a performance and leakage current requirements.
THE FIRST SELECTIVE ANTAGONIST FOR A GABAC RECEPTOR

Abstract (1,2,5,6-Tetrahydropyridine-4-yl)methylphosphinic acid (TPMPA, 1 ), which is synthesized in six steps from 3-butyn-1-ol, is the first γ-aminobutyric acid (GABA) receptor antagonist that shows strong selectivity for mammalian GABA C receptors.
Multiscale visualization using data cubes

Most analysts start with an overview of the data before gradually refining their view to be more focused and detailed. Multiscale pan-and-zoom systems are effective because they directly support this approach. However, generating abstract overviews of large data sets is difficult and most systems take advantage of only one type of abstraction: visual abstraction. Furthermore, these existing systems limit the analyst to a single zooming path on their data and thus to a single set of abstract views. This paper presents: 1) a formalism for describing multiscale visualizations of data cubes with both data and visual abstraction and 2) a method for independently zooming along one or more dimensions by traversing a zoom graph with nodes at different levels of detail. As an example of how to design multiscale visualizations using our system, we describe four design patterns using our formalism. These design patterns show the effectiveness of multiscale visualization of general relational databases.
Design and performance of a fixed, nonaccelerating guide vane cascade that operates over an inlet flow angle range of 60 deg

A unique set of wind tunnel guide vanes are designed with an inverse design code and analyzed with a panel method and an integral boundary layer code developed at the NASA Lewis Research Center. The fixed guide vanes, 80 feet long with 6-foot chord length, were designed for the NASA Ames 40 x 80/80 x 120 ft Wind Tunnel. Low subsonic flow is accepted over a 60 deg range of inlet angle from either the 40 x 80 leg or the 80 x 120 leg of the wind tunnel, and directed axially into the main leg of the tunnel where drive fans are located. Experimental tests of 1/10-scale models were conducted to verify design calculations.
Trade balance and income in historical perspective

This paper develops a dynamic analysis of the trade balance to investigate the roles of supply and demand shocks. It also introduces global shocks in the analysis to take into account the comovement of income across countries. The results, based on the long-run historical data and a structural VAR analysis, show that, in the U.K., Australia, Canada, and Sweden, domestic and global supply shocks, while dominant causes in long-term and cyclical changes in output, are unimportant for the trade balance. The trade balance is explained mostly by shocks that cause transitory changes in income. Transitory income shocks cause income and the trade balance to move in opposite directions in all countries except Sweden. The countercyclical behavior of the trade balance seems to be a robust feature in the U.K. and Canada but not in the smaller economies of Australia and Sweden.
Host mobility using an internet indirection infrastructure

We propose the Robust Overlay Architecture for Mobility (ROAM) to provide seamless mobility for Internet hosts. ROAM is built on top of the Internet Indirection Infrastructure (i3). With i3, instead of explicitly sending a packet to a destination, each packet is associated with an identifier. This identifier defines an indirection point in i3, and is used by the receiver to obtain the packet.ROAM takes advantage of end-host ability to control the placement of indirection points in i3 to provide efficient routing, fast handoff, and preserve location privacy for mobile hosts. In addition, ROAM allows end hosts to move simultaneously, and is as robust as the underlying IP network to node failure. We have developed a user-level prototype system on Linux that provides transparent mobility without modifying applications or the TCP/IP protocol stack. Simulation results show that ROAM's latency can be as low as 0.25--40% of Mobile IP. Experimental results show that with soft handoff the TCP throughput decreases only by 6% when there are as many as 0.25 handoffs per second.
Studies on the synthesis of gymnodimine. Stereocontrolled construction of the tetrahydrofuran subunit.

A bis-(2,6-dichlorobenzyl) ether is shown to undergo efficient and highly stereoselective intramolecular iodoetherification to yield a cis-2,5-disubstituted tetrahydrofuran, thus providing a powerful illustration of a stereodirecting effect first noted by Rychnovsky and Bartlett. The tetrahydrofuran was transformed into a subunit suitable for incorporation into the shellfish toxin gymnodimine.
Symmetry-seeking spacetime coordinates

In numerically constructing a spacetime that has an approximate timelike Killing vector, it is useful to choose spacetime coordinates adapted to the symmetry, so that the metric and matter variables vary only slowly with time in these coordinates. In particular, this is a crucial issue in numerically calculating a binary black hole inspiral. An approximate homothetic vector plays a role in critical gravitational collapse. We summarize old and new suggestions for finding such coordinates from a general point of view. We then test some of these in various toy models with spherical symmetry, including critical fluid collapse and critical scalar field collapse.
Eikonal contributions to ultra high energy neutrino–nucleon cross sections in low scale gravity models

Abstract We calculate low scale gravity effects on the cross section for neutrino–nucleon scattering at center of mass energies up to the Greisen–Zatsepin–Kuzmin (GZK) scale, in the eikonal approximation. We compare the cases of an infinitely thin brane embedded in n = 5 compactified extra-dimensions, and of a brane with a physical tension M S = 1 TeV and M S = 10 TeV . The extra dimensional Planck scale M D is set at 10 3 GeV and 2 × 10 3 GeV . We also compare our calculations with neutral current standard model calculations in the same energy range, and compare the thin brane eikonal cross section to its saddle point approximation. New physics effects enhance the cross section by orders of magnitude on average. They are quite sensitive to M S and M D choices, though much less sensitive to n .
Synthesis and characterization of rhodium(III) complexes bound to the novel bridging ligand 2,3,5,6-tetra(2-pyridyl)pyrazine (tppz)

We report the preparation and characterization of the first mono- and bimetallic Rh(III) complexes bound with tppz. Synthetically, the Rh-(tppz)Cl 3 complex alone is significant as a precursor complex in attempted preparation of bis-polypyridyl complexes of Rh(III)
Dynamics of Vertical Annular Liquid Jets

A theoretical model is developed to determine the flow characteristics for vertical liquid jets of annular cross section. The fully implicit numerical marching integration procedure is based on the parabolic flow theory of Patankar and Spalding. The method is more accurate and general than previous analytical models, since it accounts for all significant forces acting upon the jet and for complex boundary conditions, such as an ambient pressure difference across the jet or a non-uniform velocity profile at the inlet. Comparison of the results with existing experimental data indicates reasonable agreement, and the predictions correspond closely to those of the earlier theories for simplified flow cases.
High photorefractive sensitivity in an n-type 45°-cut BaTiO 3 crystal

The beam-coupling properties of a cobalt-doped oxygen-reduced n-type barium titanate crystal are reported in the 0 deg and 45 deg crystallographic orientations. Oxygen reduction improved the response time of the 0-deg-cut crystal by a factor of about 4.5 without diminishing the beam-coupling gain. The 45-deg-cut crystal has a peak gain of about 38.7/cm, a response time of about 21 ms, and a photorefractive sensitivity of 3.44 cu cm/kJ. From response time measurements an equivalent percentage change in the dc dielectric constant and the mobility with respect to crystallographic orientation is inferred.
Comparative chemistry of η3-oxaallyl and η3-allyl rhodium(I) complexes in the hydrosilylation of cyclopropyl ketones: observation of an unprecedented rearrangement

Abstract Addition of η3-oxaallyl bis(triphenylphosphine)rhodium(I) (1) or η3-allyl bis(triphenylphosphine)rhodium(I) (2) to a mixture of cyclopropyl phenyl ketone and triethylsilane promotes two competitive catalytic reactions. Complex 1 gives high yields of the silyl ether 13, while complex 2 favors an unprecedented cyclopropyl carbinyl ring-opening reaction providing good yields of enol silane (Z)- and (E)-14 (4.1 Z/E ratio). Studies of catalyst turnover provide evidence that two monomeric rhodium complexes account for the competing reactions. The cyclopropyl carbinyl catalysis occurs under a narrow reaction regime with a specific set of ketone substrates suitable for the reaction. Chemicals such as triethylsilane activate the catalysis leading to 13, while triphenylphosphine strongly inhibits the formation of 14. A mechanism involving a polar transition state for the cyclopropyl carbinyl rearrangement is proposed.
Accounting diversity and firm valuation

Abstract We examine accounting numbers and stock prices across three countries: Germany, Norway, and the United Kingdom (UK). The accounting systems in the three countries differ in faithfulness to clean surplus accounting and in conservatism. We address three questions. First, are there systematic differences across countries in the value relevance of accounting? Second, are there systematic differences in the incremental and relative value relevance of book values and earnings per shape (EPS) across the countries? Third, do future earnings realizations (proxies for expected earnings) explain current stock prices? We find that accounting book value and EPS are significantly related to current stock prices across all three countries. German accounting numbers have the lowest relation with stock prices (R2 ≈ 40%) and UK accounting numbers the highest (R2 ≈ 70%), while Norwegian accounting numbers are in between (R2 ≈ 60%). Second, the incremental and relative explanatory power of book value and of EPS differs across time and across countries. Book values explain more than earnings in Germany and Norway, but less in the UK. Finally, future income realization explain little about market prices not already explained by current book value and EPS.
Hydrographic changes in the eastern subpolar North Atlantic during the last deglaciation

Abstract Millennial-scale climate fluctuations of the last deglaciation have been tied to abrupt changes in the Atlantic Meridional Overturning Circulation (MOC). A key to understanding mechanisms of MOC collapse and recovery is the documentation of upper ocean hydrographic changes in the vicinity of North Atlantic deep convection sites. Here we present new high-resolution ocean temperature and δ18Osw records spanning the last deglaciation from an eastern subpolar North Atlantic site that lies along the flow path of the North Atlantic Current, approaching deep convection sites in the Labrador and Greenland-Iceland-Norwegian (GIN) Seas. High-resolution temperature and δ18Osw records from subpolar Site 980 help track the movement of the subpolar/subtropical front associated with temperature and Atlantic MOC changes throughout the last deglaciation. Distinct δ18Osw minima during Heinrich 1 (H1) and the Younger Dryas (YD) correspond with peaks in ice-rafted debris and periods of reduced Atlantic MOC, indicating the presence of melt water in this region that could have contributed to MOC reductions during these intervals. Increased tropical and subtropical δ18Osw during these periods of apparent freshening in the subpolar North Atlantic suggest a buildup of salt at low latitudes that served as a negative feedback on reduced Atlantic MOC.
Increasing power of groupwise association test with likelihood ratio test

Sequencing studies have been discovering a numerous number of rare variants, allowing the identification of the effects of rare variants on disease susceptibility. As a method to increase the statistical power of studies on rare variants, several groupwise association tests that group rare variants in genes and detect associations between groups and diseases have been proposed. One major challenge in these methods is to determine which variants are causal in a group, and to overcome this challenge, previous methods used prior information that specifies how likely each variant is causal. Another source of information that can be used to determine causal variants is observation data because case individuals are likely to have more causal variants than control individuals. In this paper, we introduce a likelihood ratio test (LRT) that uses both data and prior information to infer which variants are causal and uses this finding to determine whether a group of variants is involved in a disease. We demonstrate through simulations that LRT achieves higher power than previous methods. We also evaluate our method on mutation screening data of the susceptibility gene for ataxia telangiectasia, and show that LRT can detect an association in real data. To increase the computational speed of our method, we show how we can decompose the computation of LRT, and propose an efficient permutation test. With this optimization, we can efficiently compute an LRT statistic and its significance at a genome-wide level. The software for our method is publicly available at http://genetics.cs.ucla.edu/rarevariants.
A facile synthesis and X-ray structure determination of the first triptycenocrown ethers

The synthesis of the first triptycenocrown ethers was achieved by two-step procedure which includes condensation of 9,10-bis(chloromethyl)anthracene with polyethylene glycols to yield the intermediate 9,10-anthracenocrown ethers, and subsequent cycloaddilion of benzyne leading to the title compounds. The structures of 9,10-tnplyceno-25-crown-7 (1) and its thallium nitrate complex (Tl-1) were determined by X-Ray diffraction analysis and NMR spectroscopy.
Fate of Argon-Ion Injection in the Magnetosphere

Large-scale operation of argon-ion engines in space may give rise to global-scale modifications of the magnetosphere. This paper considers ion-injectant effects of solar-powered orbit transfer operations of large payloads (~10 kg) similar to that of the projected Satellite Power System. It is likely that the ion beam would interact and deposit its energy and mass in the magnetosphere. Magnetospheric heating may change the compositional distribution of thermal ions, thus causing enhancement of relativistic Van Alien radiation belt electrons. Effects of magnetospheric response to the ion engine beam will be discussed in this paper.
Palladium-Catalyzed Inter- and Intramolecular α-Arylation of Amides. Application of Intramolecular Amide Arylation to the Synthesis of Oxindoles

2A palladium-catalyzed α-arylation of amides is reported. Intermolecular arylation of N,N-dimethylamides and lactams occurs using aryl halides, silylamide base, and a palladium catalyst. Intramolecular arylation of N-(2-halophenyl)amides occurs using alkoxide base and a palladium catalyst. The palladium catalyst was formed in situ from Pd(dba)2 (dba = trans,trans-dibenzylidene acetone) and BINAP (2,2‘-bis(diphenylphosphino)-1,1‘-binaphthalene). Although the intermolecular arylation of amides is less general than that reported previously for ketones, unfunctionalized and electron-rich aryl halides gave α-arylamides in 48−75% yield and N-methyl-α-phenylpyrrolidinone in 49% yield. These reactions provided the highest yields yet reported for regioselective amide arylations. Intramolecular amide arylation of 2-bromoanilides gave oxindoles in 52−82% yield. Mono- and disubstituted acetanilides gave 1,3-di- and 1,3,3-trisubstituted oxindoles. The use of dioxane, rather than THF, solvent was important for some of ...
Quantum Counterfactuals and Locality

Stapp’s counterfactual argument for quantum nonlocality based upon a Hardy entangled state is shown to be flawed. While he has correctly analyzed a particular framework using the method of consistent histories, there are alternative frameworks which do not support his argument. The framework dependence of quantum counterfactual arguments, with analogs in classical counterfactuals, vitiates the claim that nonlocal (superluminal) influences exist in the quantum world. Instead it shows that counterfactual arguments are of limited use for analyzing these questions.
An Efficient [2 + 2 + 1] Synthesis of 2,5-Disubstituted Oxazoles via Gold-Catalyzed Intermolecular Alkyne Oxidation

The first efficient intermolecular reaction of gold carbene intermediates generated via gold-catalyzed alkyne oxidation has been realized using nitriles as both the reacting partner and the reaction solvent, offering a generally efficient synthesis of 2,5-disubstituted oxazoles with broad substrate scope. The overall reaction is a [2 + 2 + 1] annulation of a terminal alkyne, a nitrile, and an oxygen atom from an oxidant. The reaction conditions are exceptionally mild, and a range of functional groups are easily tolerated. With complex and/or expensive nitriles, only 3 equiv could be sufficient to achieve serviceable yields in the absence of any solvent and using only 1 mol % BrettPhosAuNTf2 as the catalyst.
Relationship between septal body size and septal deviation.

BackgroundPrevious studies have described inferior turbinate hypertrophy compensatory to a septal deviation. The septal body contains vasoactive tissue that may behave in a manner similar to the in...
On the Relationship between Risk-Dominance and Stochastic Stability

Abstract In a 2 × 2 symmetric game with two symmetric equilibria, one risk-dominates another if and only if the equilibrium strategy is a unique best response to any mixture that gives itself at least a probability of one-half. In a two-person strategic form game, we call a Nash equilibrium globally risk-dominant if it consists of strategies such that each one of them is a unique best response to any mixture that gives the other at least a probability of one-half. We show that if a weakly acyclic two-person game has a globally risk-dominant equilibrium, then this is the one that is selected by the stochastic equilibrium selection process of Young. Journal of Economic Literature Classification Numbers: C72, C73.
Magnetic Field Tuning of Charge and Spin Order in the Cuprate Superconductors

Recent neutron scattering, nuclear magnetic resonance, and scanning tunneling microscopy experiments have yielded valuable new information on the interplay between charge and spin density wave order and superconductivity in the cuprate superconductors, by using a perpendicular magnetic field to tune the ground state properties. We compare the results of these experiments with the predictions of a theory which assumed that the ordinary superconductor was proximate to a quantum transition to a superconductor with co-existing spin/charge density wave order.
Molybdenum-catalyzed asymmetric allylation of 3-alkyloxindoles: application to the formal total synthesis of (-)-physostigmine.

The first example of Mo-catalyzed asymmetric allylation for the generation of quaternary stereocenters at a prochiral nucleophile is reported. A variety of 3-alkyl oxindoles can be alkylated with high yields and enantioselectivity. This method provides expedited access to (−)-physostigmine and its analogues.
Effect of metallic coatings on the thermal contact conductance of turned surfaces

An experimental investigation was conducted to determine the degree to which the thermal contact conductance at the interface of contacting Aluminum 6061 T6 surfaces could be enhanced through the use of vapor-deposited metallic coatings. Three different coating materials (lead, tin, and indium) were evaluated using four different thicknesses for each coating material. The results verified the existence of an optimum coating thickness, shown to be in the range of 2.0 to 3.0 microns for indium, 1.5 to 2.5 microns for lead, and 0.2 to 0.5 microns for tin. The enhancement factors for thermal contact conductance were found to be on the order of 700, 400, and 50 percent, respectively. Based upon the experimental data, the hardness of the coating materials appears to be the most significant parameter in ranking the substrate and coating material combinations; however, additional experimental data are needed to substantiate this hypothesis. Finally, it was apparent that the thermal contact conductance enhancement effect was greatest at low contact pressures and decreased significantly with increases in the contact pressure.
Half-line Schrödinger operators with no bound states

acting in L2([0, c~)) with the boundary condition r For convenience, we require that the potential, V, be uniformly locally square integrable. We write l~(L 2) for the Banach space of such functions. The free operators, that is, when V--0, can be diagonalized by the Fourier transform. This shows that they have spectra [-2, 2] and [0, co), respectively, and that in both cases, the spectrum is purely absolutely continuous. For a general discrete operator, the mere fact that the spectrum is contained in [-2, 2] forces it to be purely absolutely continuous. This is our first main result:
Experience with hybrid computation

In recent years, there has been increasing emphasis on the use of electronic analog and digital computers in the fields of science, engineering, and education. Interest has also been generated in computational methods not readily available from either of these classes of computers alone, but rather from the combination of them provided by the so called hybrid computer system. This interest has been a direct result of the increase in the complexity of present day systems and hardware, and the increased accuracy required of them. Based on two years of experience with a large hybrid facility, this paper will review the main characteristics of digital and analog computers, compare their capabilities and their limitations, and show some of the reasons for and advantages of mating the two to form the hybrid computing system. We will describe some of the problems to which we have successfully supplied hybrid solutions, and predict the direction of future hybrid progress.
Mechanical processes in chemical-mechanical planarization: plasticity effects in oxide thin films

The role of plastic behavior of normally brittle oxide films in controlling materials removal mechanisms in chemical-mechanical planarization (CMP) is discussed. Particular attention is given to how material removal mechanisms are sensitive to fundamental changes in surface materials properties. It is suggested that the synergism between chemical and mechanical effects in CMP can be framed in the context of an environmentally sensitive fracture process. The concept of “fracture” in the case of CMP, however it is argued, occurs at the nanometric or ultimately at the atomistic scale. This type of paradigm for chemical-mechanical planarization is developed through an analysis of the different types of materials behavior associated with surface changes where environment and mechanical effects are coupled.
Holonomic planar motion from non-holonomic driving mechanisms: the front-point method

There are many methods that address navigation and path planning for mobile robots with non-holonomic motion constraints using clever techniques and exploiting application-specific data, but it is always better not to have any such constraints at all. In this document we re-examine the capabilities of some popular driving mechanisms from a different perspective and describe a method to obtain holonomic motion using those mechanisms. The main idea is to not concentrate on the center of the driving mechanism (which is the usual choice) as the reference point for our calculations, but to select another point whose motion in the x-y plane is not constrained in any direction, and which is also a logical and useful substitute for the center. In addition to the derivation of the forward and inverse kinematics equations for the new reference point, we also explain how to further simplify the design of a controller which uses the described method to compute motion commands for the robot. In order to illustrate the ideas, we present graphs that were plotted using the actual parameter values for a synchronous-drive research robot.
Forecasting the Discounts of Market Prices from Appraised Values for Real Estate Limited Partnerships

A vexing problem for the appraisal industry has been estimating an appropriate discount for the value of real estate limited partnerships (RELPs) relative to their appraised value. This research develops a linear regression model that explains over 80% of the cross-sectional variation in discounts across 60 RELPs using characteristics of each partnership. Among a holdout sample of 41 RELPs, the model provides forecasts of discounts that are superior to assuming no discount or applying a mean discount to all partnerships. Discounts are greatest for RELPs with low current yields, low leverage and high trading ranges for their market prices.
Iron Deficiency and Blood Lead Levels

To the Editor. — I read with interest the article “Prevalence of Blood Lead Levels ≥5 μg/dL Among US Children 1 to 5 Years of Age and Socioeconomic and Demographic Factors Associated With Blood of Lead Levels 5 to 10 μg/dL, Third National Health and Nutrition Examination Survey, 1988–1994” by Bernard and McGeehin.1 Of particular significance to me was …
Frequent recombination in the human T-cell receptor beta gene complex.

Although individual TCRVBV gene segments exhibit limited polymorphism, human T-cell receptor beta (TCRB) haplotypes are characterized by multiple different combinations of allelic markers. This observation suggests that genetic recombination may have played a role in the generation of these haplotypes. Meiotic recombination in a region spanning ≈250 kilobases (kb) at the 3′ end of the TCRB gene complex was investigated by extended family studies and by analysis of single sperm. Segregation patterns of polymorphic TCRB markers in families allowed the assignment of TCRB alleles to parental haplotypes and detection of recombinants among the offspring. Among the 178 informative paternal meioses, four (≈2%) were recombinant, whereas no recombinants were found in the 199 maternal meioses. In addition, segregation of two allelic markers was examined in a total of 1101 individual sperm from two heterozygous donors to detect exchange events in this region. The results revealed a similar rate of recombination, ≈1.3%, which, along with the family data, suggests that at, least in males, meiotic recombination in this 250 kb region may be six times higher than the “average” rate of 1% per 106 bases that has been estimated for the human genome.
Ring-retentive deprotonation of cyclopropene-3-carboxamides

A remarkable stability of anionic species generated from cyclopropene-3-carboxamides toward ring-opening is demonstrated. The resulting cyclopropenyllithium species can be reacted with a range of electrophiles, which allows for efficient introduction of additional substituents at C1 of the strained ring.
Synthesis and characterization of Cu2ZrCl6: a thermochromic, van Vleck paramagnet

Abstract The solid state reaction of CuCl and ZrCl4 yields the pale yellow crystalline solid of composition Cu2ZrCl6. This material crystallizes in the trigonal space group P3m1 (#164) at room temperature with lattice constants a=10.9092(4) and c=6.1517, Z=3. The structure is shown to be related to ZrCl3, where every other Zr site has been replaced with Cu atoms that partially occupy the six tetrahedral interstices surrounding the now vacant octahedral interstice. At room temperature, two copper atoms are disordered about three crystallographically distinct sites. Two thermochromic transitions are observed for this material at 120 and 673 K, which appear to be related to the movement of copper from the center of a tetrahedral interstice to a trigonal planar face. A second-order Jahn–Teller distortion accounts for this structural variation. This along with the insertion of the empty Zr-4d orbitals into the already small copper (I) based HOMO–LUMO gap afford significant mixing between ground and excited states resulting in notable van Vleck paramagnetism.
Branch retinal artery occlusion in a patient with multisystem vascular disease

Abstract Branch retinal artery occlusion (BRAO) is an acute, ocular condition causing blockage of a branch of the central retinal artery with subsequent infarction of the retinal tissue supplied by the distal artery. This article includes a case presentation of BRAO and a review of the clinical features and management of this condition. The need for investigation into possible underlying systemic disorders will be stressed.
Synthesis, structure and properties of the polychalcogenides [M4Te12]4− (M=Cd, Hg)

Abstract The cluster anions, [M4Te12]4− (MCd, Hg) are reported. (Et4N)4[Cd4Te12] (I) was prepared by the reaction of CdI2, K2Te2 and Et4NBr in a 2:3:2 molar ratio, in DMF. I crystallizes in the orthorhombic space group Cmca (No. 64) with a = 15.482(5), b = 22.563(4), c = 18.027(4) A, V = 6297(5) A3 and Z = 4. The black rectangular platelet crystals of (Me4N)4[Hg4Te12] (II) were obtained from the reaction of HgCl2 and K2Te in a 2:5 molar ratio in DMF. II crystallizes in the monoclinic space group P21/n (No. 14) with a = 10.324(3), b = 21.851(6), c = 11.125(4) A, β = 110.63(3)°, V = 2348(3) A3 and Z = 2. [M4Te12]4− is a cluster with two Te2−, two Te22− and two Te32− ligands connecting a planar array of four tetrahedral M2+ metal centers. Its shape may be described as a basket, consisting of an {M4(Te2)2Te2} core with two side Te32− handles. The average M-Te and Te-Te distances are 2.85(8) and 2.74(2) A for I, respectively, and 2.86(12) and 2.73(1) A for II, respectively. The far-IR spectra show two absorptions at 173 and 160 cm−1 for I and at 167 and 148 cm−1 for II. Thermal gravimetric analysis data are reported.
Evolution of unconditional dispersal in periodic environments

Organisms modulate their fitness in heterogeneous environments by dispersing. Prior work shows that there is selection against 'unconditional' dispersal in spatially heterogeneous environments. 'Unconditional' means individuals disperse at a rate independent of their location. We prove that if within-patch fitness varies spatially and between two values temporally, then there is selection for unconditional dispersal: any evolutionarily stable strategy (ESS) or evolutionarily stable coalition (ESC) includes a dispersive phenotype. Moreover, at this ESS or ESC, there is at least one sink patch (i.e. geometric mean of fitness less than one) and no sources patches (i.e. geometric mean of fitness greater than one). These results coupled with simulations suggest that spatial-temporal heterogeneity is due to abiotic forcing result in either an ESS with a dispersive phenotype or an ESC with sedentary and dispersive phenotypes. In contrast, the spatial-temporal heterogeneity due to biotic interactions can select for higher dispersal rates that ultimately spatially synchronize population dynamics.
Freeform optical systems with prescribed irradiance properties in near-field

The problem of design of a reflector system for redirecting and reshaping the irradiance distribution of a point source over a prescribed target set in the near-field is considered. The solution of this problem is developed under the geometrical optics (GO) approximation. The novelty is that our method is not limited to the usual input and/or output irradiance profiles which are rotational or rectangular symmetric. Consequently, the designer has more flexibility in satisfying the requirements of a practical design problem.
Development of mixed time partition procedures for thermal analysis of structures

The computational methods used to predict and optimize the thermal-structural behaviour of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. This proposed methodology would be readily adaptable to existing computer programs for structural thermal analysis.
Second central extension in Galilean covariant field theory

Abstract The possibility of a connection between the second central extension of the planar Galilei group and the spin variable is considered. This idea is explored within the framework of local Galilean covariant field theory for free fields of arbitrary spin. It is shown that such systems generally display only a trivial realization of the second central extension. While it is possible to realize any desired value of the extension parameter by suitable redefinition of the boost operator, such an approach has no necessary connection to the spin of the basic underlying field.
Calibrating M Dwarf Metallicities Using Molecular Indices

We report progress in the calibration of a method to determine cool dwarf star metallicities using molecular band strength indices. The molecular band index to metallicity relation can be calibrated using chemical abundances calculated from atomic-line equivalent width measurements in high-resolution spectra. Building on previous work, we have measured Fe and Ti abundances in 32 additional M and K dwarf stars to extend the range of temperature and metallicity covered. A test of our analysis method using warm star-cool star binaries shows we can calculate reliable abundances for stars warmer than 3500 K. We have used abundance measurements for warmer binary or cluster companions to estimate abundances in six additional cool dwarfs. Adding stars measured in our previous work and others from the literature provides 76 stars with Fe abundance and CaH2 and TiO5 index measurements. The CaH2 molecular index is directly correlated with temperature. TiO5 depends on temperature and metallicity. Metallicity can be estimated to within ±0.3 dex within the bounds of our calibration, which extends from roughly [{Fe}/H}] = +0.05 to –1.0, with a limited extension to –1.5.
An NMR method for determination of configuration of β-substituted carboxylic acids

Abstract The absolute configuration of the stereogenic center at the β-position of a carboxylic acid can be determined via derivatization with chiral benzylic amines [PhCH(Me)NH 2 or 1-NpCH(Me)NH 2 ]. Acids of known configuration and with a variety of β-substituents were subjected to derivatization. Analysis of the signs of the chemical shift differences of substituent protons permits determination of the absolute configuration.
Oligopolistic Competition, Firm Heterogeneity, and the Impact of International Trade

This paper studies the impact of international trade in a general equilibrium model in which heterogeneous firms engage in oligopolistic competition. An increase of the size of the market leads to a decrease of the equilibrium price and an increase of per capita consumption. The opening of international trade leads to an increased degree of competition, a lower price level, and the exit of least efficient firms. Although average profit increases, not all the surviving firms benefit from the opening of international trade.
On the production of open strings from brane anti-brane annihilation

We investigate the leading contribution to open string production in the time dependent background of the Brane Anti-Brane. This is a 1-loop diagram and we use Boundary Conformal Field Theory (BCFT) techniques to study it. We show that the amplitude to a single open string na?vely diverges when one looks at it as an expansion in oscillator levels. Nevertheless, we show that once we sum over all oscillator levels we get a finite result. We also clarify where to perform the inverse Wick rotation in this kind of problems. This calculation could have important consequences for the theory of reheating in brane inflationary models.
Strong integrality of quantum invariants of 3-manifolds

We prove that the quantum SO(3)-invariant of an arbitrary 3-manifold M is always an algebraic integer if the order of the quantum parameter is co-prime with the order of the torsion part of H 1 (M,Z). An even stronger integrality, known as cyclotomic integrality, was established by Habiro for integral homology 3-spheres. Here we also generalize Habiro's result to all rational homology 3-spheres.
Strange pathways for black hole formation

Abstract Immediately after they are born, neutron stars are characterized by an entropy per baryon of order unity and by the presence of trapped neutrinos. If the only hadrons in the star are nucleons, these effects slightly reduce the maximum mass relative to cold, catalyzed matter. However, if strangeness-bearing hypersons, a kaon condensate, or quarks are also present, these effects result in an increase in the maximum mass of up to ∼ 0.3 M ⊗ compared to that of a cold, neutrino-free star. This makes a sufficiently massive proto-neutron star metastable, so that after a delay of 10–100 seconds, the PNS collapses into a black hole. Such an event might be straightforward to observe as an abrupt cessation of neutrinos when the instability is triggered.
Cellular spanning trees and Laplacians of cubical complexes

We prove a Matrix-Tree Theorem enumerating the spanning trees of a cell complex in terms of the eigenvalues of its cellular Laplacian operators, generalizing a previous result for simplicial complexes. As an application, we obtain explicit formulas for spanning tree enumerators and Laplacian eigenvalues of cubes; the latter are integers. We prove a weighted version of the eigenvalue formula, providing evidence for a conjecture on weighted enumeration of cubical spanning trees. We introduce a cubical analogue of shiftedness, and obtain a recursive formula for the Laplacian eigenvalues of shifted cubical complexes, in particular, these eigenvalues are also integers. Finally, we recover Adin?s enumeration of spanning trees of a complete colorful simplicial complex from the Cellular Matrix-Tree Theorem together with a result of Kook, Reiner and Stanton.
Optimal policies for simultaneous energy consumption and ancillary service provision for flexible loads under stochastic prices and no capacity reservation constraint

Flexible loads, i.e. the loads whose power trajectory is not bound to a specific one, constitute a sizable portion of current and future electric demand. This flexibility can be used to improve the performance of the grid, should the right incentives be in place. In this paper, we consider the optimal decision making problem faced by a flexible load, demanding a certain amount of energy over its availability period, subject to rate constraints. The load is also capable of providing ancillary services (AS) by decreasing or increasing its consumption in response to signals from the independent system operator (ISO). Under arbitrarily distributed and correlated Markovian energy and AS prices, we obtain the optimal policy for minimising expected total cost, which includes cost of energy and benefits from AS provision, assuming no capacity reservation requirement for AS provision. We also prove that the optimal policy has a multi-threshold form and can be computed, stored and operated efficiently. We further s...
Distortive effects of initial-based name disambiguation on measurements of large-scale coauthorship networks

Scholars have often relied on name initials to resolve name ambiguities in large-scale coauthorship network research. This approach bears the risk of incorrectly merging or splitting author identities. The use of initial-based disambiguation has been justified by the assumption that such errors would not affect research findings too much. This paper tests that assumption by analyzing coauthorship networks from five academic fields-biology, computer science, nanoscience, neuroscience, and physics-and an interdisciplinary journal, PNAS. Name instances in data sets of this study were disambiguated based on heuristics gained from previous algorithmic disambiguation solutions. We use disambiguated data as a proxy of ground-truth to test the performance of three types of initial-based disambiguation. Our results show that initial-based disambiguation can misrepresent statistical properties of coauthorship networks: It deflates the number of unique authors, number of components, average shortest paths, clustering coefficient, and assortativity, while it inflates average productivity, density, average coauthor number per author, and largest component size. Also, on average, more than half of top 10 productive or collaborative authors drop off the lists. Asian names were found to account for the majority of misidentification by initial-based disambiguation due to their common surname and given name initials.
Neurobiology of Tourette syndrome

Tourette syndrome (TS), a relatively common neuropsychiatric disorder, provides a unique opportunity for studying interactions among clinical behaviors, neuroanatomic localization, and neurochemical dysfunction. As discussed in previous articles, TS is characterized by the presence of chronic motor and vocal tics that wax and wane. In addition, many people with TS manifest a variety of behavioral (attention deficit hyperactivity disorder ADHD obsessive-compulsive behaviors (OCB), and other psychopathologies) and educational difficulties. Because of the high prevalence of behavioral problems, hypothesized to be related to the putative TS gene, investigators have studied patients with TS with the expectation of identifying overlapping pathophysiologies. Although much information has been acquired pertaining to the underlying anatomy and physiology of tic disorders, many perplexing questions remain concerning how these changes interact to produce associated complex symptoms and comorbid features. Occasionally, one is tempted to take the advice of George Gilles de la Tourette, who, noting no obvious pathologic cause, referred those interested in pursuing pathophysiologic mechanisms to the field of psychology. 42 Recognizing, however, that this is an intellectually unacceptable option, this article provides a practical perspective on proposals evoking abnormalities in specific brain regions and neurotransmission. This article includes 1) a discussion of approaches designed to determine neuroanatomic localization through the use of physical examination, electrophysiologic and neuroradiographic studies, and neuropathologic evaluations; 2) a review of the anatomy, function, and biochemistry of frontal-subcortical circuits; 3) a discussion of inferred and direct evidence supporting a disorder of frontalsubcortical circuits in TS; and 4) a review of studies investigating specific neurotransmitters.
Rothberger bounded groups and Ramsey theory

Abstract We show that: (1) Rothberger bounded subgroups of σ-compact groups are characterized by Ramseyan partition relations (Corollary 4). (2) For each uncountable cardinal κ there is a T 0 topological group of cardinality κ such that ONE has a winning strategy in the point-open game on the group and the group is not a closed subspace of any σ-compact space (Theorem 8). (3) For each uncountable cardinal κ there is a T 0 topological group of cardinality κ such that ONE has a winning strategy in the point-open game on the group and the group is σ-compact (Corollary 17).
Polynomials and Primes in Generalized Arithmetic Progressions

We provide upper bounds on the density of a symmetric generalized arithmetic progression lacking nonzero elements of the form h(n) for natural numbers n, or h(p) with p prime, for appropriate polynomials h with integer coefficients. The prime variant can be interpreted as a multi-dimensional, polynomial extension of Linnik's Theorem.
Atomic Clocks and Precision Measurements

We present a review of our clock science conducted under the NASA Microgravity Fundamental Physics program. Our work has led to the development of rubidium atomic clocks, designs for ground- and space-based clocks that juggle atoms to achieve ultrahigh stability and accuracy, improved microwave cavities for atomic clocks, and elucidation of new systematic errors such as the atomic recoil from microwave photons. High stability clocks can be used for precise tests of fundamental physics and accurate deep-space navigation.
Rapid Synthesis of 5-O-(tert-Butyldiphenylsilyl)-2-deoxy-L-ribonolactone

Abstract A convenient, four-step synthesis of the title compound (1) in 21% overall yield from L-arabinose is described. Selective formation of the 2-O-phenoxythiocarbonyl derivative 6 and its tributyltin hydride/azobis(isobutyronitrile) deoxygenation performed in the presence of an unprotected hydroxyl group are highlighted.
Accelerated and Ambient He Abundances from Gamma-Ray Line Measurements of Flares

The γ-ray lines from 7Be and 7Li produced when flare-accelerated He nuclei interact with ambient He have been found to be surprisingly intense from measurements made by moderate-resolution γ-ray spectrometers on the Solar Maximum Mission (SMM) and Compton Gamma Ray Observatory (CGRO) satellites. These high intensities suggest either accelerated α/proton ratios 0.5 and/or an He/H abundance greater than 0.1 in the subcoronal regions where the particles interact. We have studied additional γ-ray lines in 20 flares produced by interactions of α particles on 56Fe and other elements to resolve this ambiguity. These measurements indicate, on average, that the ambient He abundance is consistent with accepted photospheric values and that an enhanced concentration of He is present in flare-accelerated particles. Although there is evidence for the presence of accelerated 3He, its concentration is only a fraction of accelerated 4He. These studies also revealed a new weak line in the spectra at ~1.32 MeV that is attributed to an excited state of 55Fe.