cssi/SciSciGPT-SciSciNet huggingface dataset:
Monitoring of IR Clear-Sky Radiances over Oceans for SST (MICROS)

AbstractMonitoring of IR Clear-Sky Radiances over Oceans for SST (MICROS) is a Web-based tool to monitor “model minus observation” (M − O) biases in clear-sky brightness temperatures (BTs) and sea surface temperatures (SSTs) produced by the Advanced Clear-Sky Processor for Oceans (ACSPO). Currently, MICROS monitors M − O biases in three Advanced Very High Resolution Radiometer (AVHRR) bands centered at 3.7, 11, and 12 μm for five satellites, NOAA-16, -17, -18, -19 and Meteorological Operational (MetOp)-A. The fast Community Radiative Transfer Model (CRTM) is employed to simulate clear-sky BTs, using Reynolds SST and National Centers for Environmental Prediction Global Forecast System profiles as input. Simulated BTs are used in ACSPO for improving cloud screening, physical SST inversions, and monitoring and validating satellite BTs. The key MICROS objectives are to fully understand and reconcile CRTM and AVHRR BTs, and to minimize cross-platform biases through improvements to ACSPO algorithms, CRTM and it...
On Decentralized Estimation With Active Queries

We consider the problem of decentralized 20 questions with noise for multiple players/agents under the minimum entropy criterion in the setting of stochastic search over a parameter space, with application to target localization. We propose decentralized extensions of the active query-based stochastic search strategy that combines elements from the 20 questions approach and social learning. We prove convergence to correct consensus on the value of the parameter. This framework provides a flexible and tractable mathematical model for decentralized parameter estimation systems based on active querying. We illustrate the effectiveness and robustness of the proposed decentralized collaborative 20 questions algorithm for random network topologies with information sharing.
The emergence of non- albicans Candida species as causes of invasive candidiasis and candidemia

The last three decades have seen an expanding pool of high-risk patients susceptible to the opportunistic pathogen Candida. Accordingly, a dramatic increase in nosocomial blood stream infections (BSIs) due to Candida spp has been reported throughout the world, starting in tertiary care centers and spreading to community hospitals. This absolute increase in Candida BSIs was accompanied by both an absolute and then a proportional increase in invasive infection caused by reduced fluconazole-susceptible non-albicans Candida spp. Currently, the incidence trend of BSI has stabilized, and Candida albicans remains the most common species causing fungal BSI. Clinicians must be aware of the importance and implications of non-albicans Candida spp when selecting antifungal drugs, although most studies have not shown significant outcome differences with use of the various antifungal classes.
Design of a new cascade reaction for the construction of complex acyclic architecture: the tandem acyl-claisen rearrangement.

Tandem or domino reactions have long been established as powerful chemical tools for the rapid formation of complex cyclic and polycyclic architecture. Surprisingly, however, relatively few tandem strategies have been directed toward the production of acyclic structural motifs despite significant advances in the area of acyclic stereocontrol. In our recent study, we reported the development of the acyl-Claisen rearrangement, a catalytic [3,3]-bond reorganization that allows the stereoselective synthesis of α,β-disubstituted-γ,δ-unsaturated carbonyls. In this communication, we outline the development of the tandem acyl-Claisen reaction, a highly stereoselective three-component coupling that enables the rapid construction of complex acyclic systems in the context of 2,3,6-trisubstituted-1,7-dioxoheptane architecture (eq 1). This versatile cascade sequence is conducted by using simple allyl diamines and acid chlorides, chemicals that are widely available in a diverse range of structural formats. As such, we expect this tandem reaction to be of broad utility to a number of chemical fields that employ molecule construction including natural product and parallel medicinal agent synthesis.
Convergent, stereoselective synthesis of the caloporoside disaccharide

Abstract A concise, convergent synthesis of the caloporoside disaccharide is described in which the key step involves direct, stereoselective formation of the β-mannosidic linkage by the sulfoxide method.
Comparing Merger Policies in the European Union and the United States

We collect a sample of EU and US merger investigations, estimate models of the regulatory decisions, and use the models to compare merger policies. Our approach allows us to decompose observed differences into policy effects and case-mix effects. Focusing on dominance mergers, we find that the EU is tougher than the US on average, in particular for mergers resulting in moderate market shares. However, the US appears to be more aggressive for coordinated interaction and non-dominance unilateral effects cases. Overall, our analysis detects substantial differences in policies, but it does not classify one regime as being more aggressive than the other.
Unmanaged Internet Protocol: taming the edge network management crisis

Though appropriate for core Internet infrastructure, the Internet Protocol is unsuited to routing within and between emerging ad-hoc edge networks due to its dependence on hierarchical, administratively assigned addresses. Existing ad-hoc routing protocols address the management problem but do not scale to Internet-wide networks. The promise of ubiquitous network computing cannot be fulfilled until we develop an Unmanaged Internet Protocol (UIP), a scalable routing protocol that manages itself automatically. UIP must route within and between constantly changing edge networks potentially containing millions or billions of nodes, and must still function within edge networks disconnected from the main Internet, all without imposing the administrative burden of hierarchical address assignment. Such a protocol appears challenging but feasible. We propose an architecture based on self-certifying, cryptographic node identifies and a routing algorithm adapted from distributed hash tables.
Some Geometric Calculations on Wasserstein Space

We compute the Riemannian connection and curvature for the Wasserstein space of a smooth compact Riemannian manifold.
From billiards to thermodynamics

Abstract We explore some beginning steps in stochastic thermodynamics of billiard-like mechanical systems by introducing extremely simple and explicit random mechanical processes capable of exhibiting steady-state irreversible thermodynamical behavior. In particular, we describe a Markov chain model of a minimalistic heat engine and numerically study its operation and efficiency.
Search for slowly moving magnetic monopoles

Abstract We report a search for slowly moving magnetic monopoles in the cosmic radiation with the first supermodule of the MACRO detector at Gran Sasso. The absence of candidates established an upper limit on the monopole flux of 5.6 × 10−15cm−2sr−1s−1 at 90% confidence level for the velocity range of 10 −4 $ β −3 .
The external returns to education: Evidence from Chinese cities

Abstract Following Rauch's seminal study, there has been a growing interest among economists in estimating human capital externalities at the individual level [J. Rauch, Productivity gains from geographic concentration of human capital: Evidence from the cities, Journal of Urban Economics 34 (1993) 380–400]. In this paper, we provide a first set of estimates of the external returns to education in Chinese cities. We find that the external returns are at least as high as the private returns to education. OLS estimates of the external returns range from a low of 4.9% to a high of 6.7%. Two-stage least squares estimates indicate that a one-year increase in city average education could increase individual earnings by between 11 and 13%. We also examine the impact of economic reforms on the external returns to education and find suggestive evidence that economic reforms have raised the external returns to education in Chinese cities.
Three-photon absorption of a new series of halogenated fluorene derivatives

Abstract In this Letter, we report the characterization of the pure three-photon absorption and the measurement of the three-photon absorption cross-section ( σ 3 ′ ) of a new series of halogenated fluorene derivatives. The three-photon absorption of these compounds corresponds to the S 0 → S 1 electronic transition. All four compounds presented here have potential application as photosensitizers in deep photodynamic therapy induced via high order nonlinear absorption. The measurements were done using a tunable OPG pumped by a 25 ps Nd-YAG laser, and performing transmittance vs. input intensity as well as open aperture Z -scan at different wavelengths to determine the highest value of σ 3 ′ .
Vortices in superconductors: modelling and computer simulations

Vortices in superconductors are tubes of magnetic flux, or equivalently, cylindrical current loops, that penetrate into a material sample. Knowledge about the structure and dynamics of collections of vortices is of importance both to the understanding of the basic physics of superconductors and to the design of devices. We first discuss homogeneous isotropic superconductors that can be modelled by the Ginzburg–Landau theory. We then discuss variants of this model that can account for inhomogenieties and anisotropies due to impurities, thickness variations, and thermal fluctuations. These all effect changes in the vortex state, as do changes in the applied magnetic field and current strengths and directions. Through computational simulations, we use the various models to illustrate these changes. In particular, we examine the pinning of vortices by thickness variations in thin–films, by impurities and by grain boundaries, the effects that changes in the thickness of a simple Josephson junction have on the structure of the vortex state, transitions that occur in the vortex state as the applied magnetic field is increased, and distortions of that state due to thermal fluctuations.
The Novel Synthesis of Silicon and Germanium Nanocrystallites

Interest in the synthesis of semiconductor nanoparticles has been generated by their unusual optical and electronic properties arising from quantum confinement effects. We have synthesized silicon and germanium nanoclusters by reacting Zintl phase precursors with either silicon or germanium tetrachloride in various solvents. Strategies have been investigated to stabilize the surface, including reactions with RLi and MgBrR (R = alkyl). This synthetic method produces group IV nanocrystals with passivated surfaces. These nanoparticle emit over a very large range in the visible region. These particles have been characterized using HRTEM, FTIR, UV-Vis, solid state NMR, and fluorescence. The synthesis and characterization of these nanoclusters will be presented.
Direct-bandgap emission from hydrostatically tensile-strained Germanium nanocrystals

We report on the high room-temperature luminescence from Germanium nanocrystals synthesized by mechanical grinding. Transients and optical spectroscopy measurements are consistent with HRTEM and electron diffraction, suggesting high tensile strains favoring direct band-to-band transitions.
Phase Transition in the Conductive Molecular Crystals Bis(tetramethyltetraselenafulvalene)[bis(trifluoromethyl)-ethylene]diselenolatonickel and -platinum, [TMTSF]2[M(tds)2], M = Ni, Pt. Relation to the Copper Analogue

The quasi-two-dimensional title compounds are obtained by the galvanostatic electrolysis of 1,1,2-trichloroethane solutions containing tetramethyltetraselenafulvalene and the appropriate monoanionic metal complex.
Some fibered and non-fibered links at infinity of hyperbolic complex line arrangements

Abstract Let F be R or C , d:= dim R ( F ) . Denote by P ( F ) either the affine plane A ( F ) or the hyperbolic plane H ( F ) over F . An arrangement L of k lines in P ( F ) (pairwise non-parallel in the hyperbolic case) has a link at infinity K ∞ ( L ) comprising k unknotted ( d −1)-spheres in S 2 d −1 , whose topology reflects the combinatorics of L “at infinity”. The class of links at infinity of affine F -line arrangements is properly included in the class of links at infinity of hyperbolic F -line arrangements. Many links at infinity of (essentially non-affine) connected hyperbolic C -line arrangements are far from being fibered. In contrast, if the (affine or hyperbolic) R -line arrangement L R ⊂ P ( R ) is connected, and L = C L R ⊂ P ( C ) is its complexification, then K ∞ ( L ) is fibered.
Ab initio thermochemistry involving heavy atoms: an investigation of the reactions Hg + IX (X = I, Br, Cl, O).

Accurate 0 K enthalpies have been calculated for reactions of mercury with a series of small iodine-containing molecules (I2, IBr, ICl, and IO). The calculations have been carried out with the coupled cluster singles and doubles method with a perturbative correction for connected triple excitations [CCSD(T)] using sequences of correlation consistent basis sets and accurate relativistic pseudopotentials. Corrections have been included to account for core-valence correlation, spin−orbit coupling, scalar relativity, and the Lamb shift. In a few cases coupled cluster calculations with iterative triple (CCSDT) and quadruple (CCSDTQ) excitations have been carried out to estimate the effects of higher order electron correlation. The pseudopotential calculations have also been compared to all electron calculations using second- and third-order Douglas−Kroll−Hess Hamiltonians. In addition to the reaction enthalpies, heats of formation, bond lengths, and harmonic vibrational frequencies have been calculated for the...
The Van den Bergh duality and the modular symmetry of a Poisson variety

We consider a smooth Poisson affine variety with the trivial canon-ical bundle over \({\mathbb{C}}\). For such a variety the deformation quantization algebra \(A_\hbar\) obeys the conditions of the Van den Bergh duality theorem and the corresponding dualizing module is determined by an outer automorphism of \(A_\hbar\) intrinsic to \(A_\hbar\). We show how this automorphism can be expressed in terms of the modular class of the corresponding Poisson variety. We also prove that the Van den Bergh dualizing module of the deformation quantization algebra \(A_\hbar\) is free if and only if the corresponding Poisson structure is unimodular.
High spectral resolution measurements of a solar flare hard X-ray burst

Observations are reported of an intense solar flare hard X-ray burst on June 27, 1980, made with a balloon-borne array of liquid nitrogen-cooled Ge detector which provided unprecedented spectral resolution (no more than 1 keV FWHM). The hard X-ray spectra throughout the impulsive phase burst fitted well to a double power-law form, and emission from an isothermal 0.1-1 billion K plasma can be specifically excluded. The temporal variations of the spectrum indicate that the hard X-ray burst is made up of two superposed components: individual spikes lasting about 3-15 sec, which have a hard spectrum and a break energy of 30-65 keV; and a slowly varying component characterized by a soft spectrum with a constant low-energy slope and a break energy which increases from 25 kev to at least 100 keV through the event. The double power-law shape indicates that DC electric field acceleration, similar to that occurring in the earth's auroral zone, may be the source of the energetic electrons which produce the hard X-ray emission.
Reoperative Median Sternotomy Using a Cast Spreader

Repeat median sternotomy carries a high mortality rate secondary to a higher incidence of injury to the underlying vital structures. The reported incidence of reentry accidents may be as high as 6% to 10%. We describe a new technique of redo sternotomy using a nitrogen-powered oscillating saw and a cast spreader. The new technique was used for 89 consecutive cases without any incidence of injury to the underlying structures. The use of a case spreader during repeat median sternotomy may enhance the safety of reentry.
Pattern Avoiding Ballot Paths and Finite Operator Calculus

Counting pattern avoiding ballot paths begins with a careful analysis of the pattern. Not the length, but the characteristics of the pattern are responsible for the difficulties in finding explicit solutions. Certain features, like overlap and difference in number of → and ↑ steps determine the solution of the recursion formula. If the recursion can be solved by a polynomial sequence, we apply the Finite Operator Calculus to find an explicit form of the solution in terms of binomial coefficients.
Factorization of Multiparticle Scattering in the Heisenberg Spin Chain

We give an explicit proof within the framework of the Bethe ansatz/string hypothesis of the factorization of multiparticle scattering in the antiferromagnetic spin-1/2 Heisenberg spin chain, for the case of three particles.
Square Function Characterization of Weak Hardy Spaces

We obtain a new square function characterization of the weak Hardy space $$H^{p,\infty }$$ for all $$p\in (0,\infty )$$ . This space consists of all tempered distributions whose smooth maximal function lies in weak $$L^p$$ . Our proof is based on interpolation between $$H^p$$ spaces. The main difficulty we overcome is the lack of a good dense subspace of $$H^{p,\infty }$$ which forces us to work with general $$H^{p,\infty }$$ distributions.
Far infrared fourier transform spectroscopy of semiconductors

Fourier transform spectroscopy (FTS) is one of the most important tools in the study of shallow level donors and acceptors in semiconductors. When combined with a two-step photothermal ionization process detected photoconductively, FTS allows measurement of optical transitions of donor-bound electrons (and acceptor-bound holes) in ultra-pure germanium samples with impurity concentrations <109 cm−3 (i.e. one electrically active impurity in 4×1013 host atoms). The experimental high resolution study of the hydrogen-like excited state series of shallow levels has yielded as many as 19 lines of width as small as 10μeV for some centers. These results have stimulated theoretical work which has led to the unambiguous assignment of quantum states to many bound excited states. Extensive studies of ultra-pure Ge crystals grown under different well-controlled conditions have led to the discovery of a large number of novel shallow impurity complexes. Study of the multiplicities and symmetries of the associated electronic states has led to a detailed understanding of the unusual static and dynamic structures of these novel centers. The chemical composition has been deduced from correlations between the concentration of a particular center and the materials involved in crystal gowth. Isotopic substitution of hydrogen with deuterium has led to the unambiguous proof of the presence of hydrogen in several of the novel centers. In addition to the high resolution spectra of shallow electronic levels, vibrational spectra of bond-centered interstitial oxygen in ultra-pure Ge are noteworthy for their extraordinarily sharp lines.
Half branes, singular brane intersections, and Kaluza-Klein reduction

Two subtle aspects of brane intersections are investigated. The first concerns the `half-branes' that arise in discussions of the Hanany-Witten effect, often in the D0/D8 setting. The second involves the validity of seemingly singular classical BPS brane intersections. A study of holomorphic curves in the background of a Kaluza-Klein monopole and the associated reduction to type-IIA supergravity sheds light on both issues. Many seemingly singular D2/D6 intersections are shown to lift to smooth configurations of M2-branes in 11-dimensions, and a mechanism is found for certain 2 confinement effects in type II string theories that eliminates any need for half-branes.
Information acquisition and opportunistic behavior in managerial reporting

Prior experimental studies have investigated factors affecting the honesty of managerial reporting in contexts where managers have no discretion in determining what information to acquire before making their reports. In many organizations, however, responsibility for acquiring information is delegated to local managers. Such delegated decision rights give managers discretion regarding what information to supply to the accounting system on which their reports are based. We predict that discretion may promote opportunistic reporting behavior because it allows managers to avoid relevant information and, in turn, report so as to maximize personal wealth without being knowingly untruthful. We investigate this prediction via two experiments. Results of Experiment 1 suggest that whether discretion in information acquisition affects reporting behavior is influenced by an individual’s preference for honesty (i.e., ethical type). We conduct Experiment 2 to investigate whether this is the case. Results show that, although discretion does not affect the reporting behavior of participants with low or high honesty preferences, participants with moderate honesty preferences tend to exploit discretion in order to avoid relevant information and report opportunistically. Our results suggest that the ability to exploit opportunities afforded by discretion in information acquisition is a potential cost when weighing the costs and benefits of assigning decision rights to managers. Our results also highlight the importance of considering a manager’s ethical type when assigning decision rights.
Conservation patterns in different functional sequence categories of divergent Drosophila species.

We have explored the distributions of fully conservedungapped blocks in genome-wide pairwise alignments of recently completedspecies of Drosophila: D.yakuba, D.ananassae, D.pseudoobscura, D.virilisand D.mojavensis. Based on these distributions we have found that nearlyevery functional sequence category possesses its own distinctiveconservation pattern, sometimes independent of the overall sequenceconservation level. In the coding and regulatory regions, the ungappedblocks were longer than in introns, UTRs and non-functional sequences. Atthe same time, the blocks in the coding regions carried 3N+2 signaturecharacteristic to synonymic substitutions in the 3rd codon positions.Larger block sizes in transcription regulatory regions can be explainedby the presence of conserved arrays of binding sites for transcriptionfactors. We also have shown that the longest ungapped blocks, or'ultraconserved' sequences, are associated with specific gene groups,including those encoding ion channels and components of the cytoskeleton.We discussed how restrained conservation patterns may help in mappingfunctional sequence categories and improving genomeannotation.
The ‘Bush Doctrine’ as a hegemonic discourse strategy

Even if preventive military counter‐terrorism may sometimes be ethically justifiable, it remains an open question whether the Bush Doctrine presented a discursively coherent account of the relevant normative conditions. With a view towards answering this question, this article critically examines efforts to ground the morally personifying language of the Bush Doctrine in term of hegemonic stability theory. Particular critical attention is paid to the arguments of leading proponents of this brand of game theory, including J. Yoo, E. Posner, A. Sykes, and J. Goldsmith. When examined in their terms, the Bush Doctine is best understood as an ethically hypocritical and shortsighted international discursive strategy. Its use of moralistic language in demonizing ‘rogue states’ for purely amoral purposes is normatively incoherent and discursively unsustainable. If it is a strategically rational piece of international communication, it seems designed to undermine globally shared normative meanings for the sake of ...
Macdonald’s evaluation conjectures and difference Fourier transform

In the previous author's paper the Macdonald norm conjecture (including the famous constant term conjecture) was proved. This paper contains the proof of the remaining two (the duality and evaluation conjectures). The evaluation theorem is in fact a $q,t$-generalization of the classic Weyl dimension formula. As to the duality theorem, it states that the generalized trigonometric-difference zonal Fourier transform is self-dual (at least formally). We define this transform in terms of double affine Hecke algebras related to elliptic braid groups. The duality appeared to be directly connected with the transposition of the periods of an elliptic curve.
Some novel concepts in aromatic reactivity

Abstract Suggestions 1 that radical-chain reactions of aryl halides with alkoxide ions, nucleophiles and alkenes occur via attack of these reagents on the aryl halide radical anion, rather than on the radical that results from fragmentation of the radical anion, are examined in detail. Several conceivable mechanisms for the suggested direct displacement of halide ion from the radical anion by a nucleophile are examined; all are unacceptable because of violation of quantum-mechanical principles or incompatibility with experimental observations. Steps involving attachment of a hydrogen atom or an alkene molecule to C-1 of an aryl halide radical anion, to form a cyclohexadienide ion intermediate, lack experimental precedent.
Relation of Chronotype to Sleep Complaints in the General Finnish Population

Individuals show variation in their preference for the daily timing of activities. In this study the authors analyzed whether chronotypes associate with sleep duration and sleep-related complaints. The authors used the National FINRISK Study 2007 Survey data on 3696 women and 3162 men, representative of the Finnish population aged 25 yrs and older, for the assessment of chronotype and self-reported sleep. Evening types experienced insomnia symptoms, had nightmares, and had used recently hypnotics significantly more often than other chronotypes among both men and women. In a multinominal logistic regression model predicting insufficient sleep, the association of eveningness with insufficient sleep was not abolished after adjustment for sex, age, and sleep duration. The prevalence of short sleepers was significantly higher in evening types among men than among women, whereas that of long sleepers was significantly higher in evening types among both men and women, as compared with the other chronotypes. Thes...
The Impact of the Earned Income Tax Credit on Poverty: Analyzing the Dimensions by Race and Immigration

This paper analyzes the effectiveness of the Earned Income Tax Credit (EITC) on poverty transitions, with an emphasis on native-born African–Americans and immigration. A probit model is estimated using data from the Current Population Survey (CPS), which evaluates the impact of EITC participation and immigration on transitions out of poverty. The EITC is found to be a useful tool in combating poverty and is effective for African–Americans, though only for women. More importantly, the results show that the implementation of state-level EITCs can mitigate the adverse effects of immigration for native-born African–Americans.
Lattice QCD at non-zero temperature

I review our current understanding of the properties of strongly interacting matter at high temperatures, based upon numerical calculations in lattice QCD. I discuss the chiral and deconfining aspects of the QCD transition, the equation of state, fluctuations of conserved charges, color screening, meson correlation functions, and the determination of some transport coefficients.
Results from the ATS 3 reflectometer experiment

ATS 3 satellite reflectometer experiment carrying test samples to measure specular reflectance, noting silica shield effects
Experimental Investigation of Steady and Unsteady Flow Field Downstream of an Automotive Torque Converter Turbine and Inside the Stator: Part II—Unsteady Pressure on the Stator Blade Surface

The stator flow field of an automotive torque converter is highly unsteady due to potential and viscous interactions with upstream and downstream rotors. The objective of this investigation is to understand the influence of potential and viscous interactions of the upstream rotor on the stator surface pressure field with a view toward improvement of the stator design. Five miniature fast-response pressure transducers were embedded on the stator blade. The measurements were conducted at three locations near the leading edge and two locations near the trailing edge at the midspan location. The upstream flow field was measured using a fast response five-hole probe and is described in Part I of this paper. The experimental data were processed in the frequency domain by spectrum analysis and in the temporal-spatial domain by the ensemble-averaging technique. The flow properties were resolved into mean, periodic, aperiodic, and unresolved components. The unsteady amplitudes agreed well with the pressure envelope predicted by panel methods. The aperiodic component was found to be significant due to the rotor-rotor and rotor-stator interactions observed in multistage, multispool environment.
Anomalous Propagation Of Luminescence Through Bulk n-InP

Implementation of a semiconductor as a scintillator with a lattice-matched surface photo-diode for radiation detection requires efficient luminescence collection. Low and heavily doped bulk n-InP has been studied to optimize luminescence transmission via photon recycling.
Convergence in international output

SUMMARY This paper proposes and tests new definitions of convergence and common trends for per capita output. We define convergence for a group of countries to mean that each country has identical long-run trends, either stochastic or deterministic, while common trends allow for proportionality of the stochastic elements. These definitions lead naturally to the use of cointegration techniques in testing. Using centurylong time series for 15 OECD economies, we reject convergence but find substantial evidence for common trends. Smaller samples of European countries also reject convergence but are driven by a lower number of common stochastic trends.
Alternatives to dark matter and dark energy

Abstract We review the underpinnings of the standard Newton–Einstein theory of gravity, and identify where it could possibly go wrong. In particular, we discuss the logical independence from each other of the general covariance principle, the equivalence principle and the Einstein equations, and discuss how to constrain the matter energy–momentum tensor which serves as the source of gravity. We identify the a priori assumption of the validity of standard gravity on all distance scales as the root cause of the dark matter and dark energy problems, and discuss how the freedom currently present in gravitational theory can enable us to construct candidate alternatives to the standard theory in which the dark matter and dark energy problems could then be resolved. We identify three generic aspects of these alternate approaches: that it is a universal acceleration scale which determines when a luminous Newtonian expectation is to fail to fit data, that there is a global cosmological effect on local galactic motions which can replace galactic dark matter, and that to solve the cosmological constant problem it is not necessary to quench the cosmological constant itself, but only the amount by which it gravitates.
Singular monopoles and supersymmetric gauge theories in three dimensions

According to the proposal of Hanany and Witten, Coulomb branches of N = 4 SU(n) gauge theories in three dimensions are isometric to moduli spaces of BPS monopoles. We generalize this proposal to gauge theories with matter, which allows us to describe the metrics on their spaces of vacua by means of the hyper-Kahler quotient construction. To check the identification of moduli spaces a comparison is made with field theory predictions. For SU(2) theory with k fundamental hypermultiplets the Coulomb branch is expected to be the D_k ALF gravitational instanton, so our results lead to a construction of such spaces. In the special case of SU(2) theory with four or fewer fundamental hypermultiplets we calculate the complex structures on the moduli spaces and compare them with field-theoretical results. We also discuss some puzzles with brane realizations of three-dimensional N = 4 theories.
Diastereoselective Asymmetric Induction in the Thio-Claisen Rearrangement Over Zeolites

Abstract S-Allyl γ-hydroxy ketene dithioacetals [ 1a–1e ] underwent a rapid and diastereoselective thio-Claisen rearrangement into anti α-allyl β-hydroxy dithioesters [ 2a–2e ] over various zeolites at room temperature in hexane is described. © 1997 Elsevier Science Ltd.
Three-Dimensional Matrix Superpotentials

We present a classification of matrix superpotentials that correspond to exactly solvable systems of Schrodinger equations. Superpotentials of the form $$ {W_k}=kQ+P+\frac{1}{k}R $$ are considered, where k is a parameter and P, Q, and R are Hermitian matrices that depend on a variable x. The list of three-dimensional matrix superpotentials is presented in explicit form.
A few problems and techniques in turbulent reactive systems

Mathematical notions as applied to the study of turbulent reactive flows are described. Topics covered include: application of an intermittency formalism to two-species very fast chemistry; presentation of some probability notions for fast chemistry; and combination of probability and intermittency, two basic ingredients in most flows, in a predictive formalism. (GHT)
Vicinal difunctionalization of dehydropiperidines using α-chloro-β-sulfonyl eneformamides

Abstract The synthesis of α,β-difunctionalized dehydropiperidines has been accomplished using α-halo-β-sulfonyl eneformamides. This outcome is achieved through sequential regioselective Cβ-alkylative desulfonation and Cα-palladium-catalyzed cross-coupling. In most cases, high yields of the vicinally functionalized eneformamides are obtained.
Different Effect of Proteasome Inhibition on Vesicular Stomatitis Virus and Poliovirus Replication

Proteasome activity is an important part of viral replication. In this study, we examined the effect of proteasome inhibitors on the replication of vesicular stomatitis virus (VSV) and poliovirus. We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication. In contrast, poliovirus replication was delayed, but not diminished in the presence of the proteasome inhibitors MG132 and Bortezomib. We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2α, and overall inhibition of translation. VSV replication was sensitive to this stress with significant decline in replication process. Poliovirus growth was less sensitive with only delay in replication. Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis. Protein kinase GCN2 supported the ability of proteasome inhibitors to attenuate general translation and to suppress VSV replication. We propose that different mechanisms of translational initiation by VSV and poliovirus determine their sensitivity to stress induced by the inhibition of proteasomes. To our knowledge, this is the first study that connects the effect of stress induced by proteasome inhibition with the efficiency of viral infection.
FR901464: Total Synthesis, Proof of Structure, and Evaluation of Synthetic Analogues

The natural product FR901464 (1) was isolated by the Fujisawa Pharmaceutical Co. and shown to have intriguing biological properties including impressive antitumor activity. In this paper we describe the first total synthesis of 1 in full detail. A chiral building block synthetic strategy was used to assemble the target: optically active components were generated using asymmetric catalytic reactions, and these fragments were coupled together at a late stage in a convergent synthesis. In particular, a versatile, asymmetric hetero-Diels-Alder (HDA) reaction was developed in the context of this synthesis and used with great effectiveness for the preparation of the two densely functionalized pyran rings. The flexible nature of the synthetic route also allowed us to prepare a series of analogues of 1. These compounds were used to prove the relative stereochemistry of the natural product as well as to probe the importance of certain structural features of FR901464 with regard to biological activity.
Reflection Electron Microscopy and Spectroscopy for Surface Analysis

This book give an overview of reflection electron microscopy using both image and diffraction to study surface crystallography. Electron energy loss spectroscopy is also discussed as a tool to analyse the chemical and structural aspects of surfaces. The author gives an extensive and complete presentation of the techniques with many practical examples and the theoretical background necessary to explain the experimental observations. Theoretical approaches are discussed in detail: kinematical and dynamical theory and multislice theories for image and diffraction studies. FORTRAN source codes are included for calculating crystal structure data and electron energy loss spectra in different scattering geometries. A very complete review of all work performed in reflection electron microscopy with an exhaustive bibliography is provided at the end of the book. It forms an exciting support for the understanding of surface studies by reflection electron microscopy. Illustrated by many beautiful and pertinent REM images and well-designed line drawings, this book should certainly be useful for graduate students and scientists working on surface characterization during processes such as MBE growth or surface cleaning. Andre Rocher
G-functions and multisum versus holonomic sequences

Abstract The purpose of the paper is three-fold: (a) we prove that every sequence which is a multidimensional sum of a balanced hypergeometric term has an asymptotic expansion of Gevrey type-1 with rational exponents, (b) we construct a class of G -functions that come from enumerative combinatorics, and (c) we give a counterexample to a question of Zeilberger that asks whether holonomic sequences can be written as multisums of balanced hypergeometric terms. The proofs utilize the notion of a G -function, introduced by Siegel, and its analytic/arithmetic properties shown recently by Andre.
Matrix-free constructions of circulant and block circulant preconditioners

A framework for constructing circulant and block circulant preconditioners (C) for a symmetric linear system Ax=b arising from signal and image processing applications is presented in this paper. The proposed scheme does not make explicit use of matrix elements of A. It is ideal for applications in which A only exists in the form of a matrix vector multiplication routine, and in which the process of extracting matrix elements of A is costly. The proposed algorithm takes advantage of the fact that for many linear systems arising from signal or image processing applications, eigenvectors of A can be well represented by a small number of Fourier modes. Therefore, the construction of C can be carried out in the frequency domain by carefully choosing the eigenvalues of C so that the condition number of CTAC can be reduced significantly. We illustrate how to construct the spectrum of C in a way that allows the smallest eigenvalues of CTAC to overlap with those of A extremely well while making the largest eigenvalues of CTAC several orders of magnitude smaller than those of A. Numerical examples are provided to demonstrate the effectiveness of the preconditioner on accelerating the solution of linear systems arising from image reconstruction applications. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of Fluorine on the Phase Separation of Na2O‐SiO2 Glasses

Immiscibility temperature of 13 mol% Na2O-87 mol% SiO2 glass was found to increase with F addition. Electron micrographs indicated that the microstructure size did not change appreciably with F addition.
Progress toward the synthesis of the basiliolides and transtaganolides: an intramolecular pyrone Diels-Alder entry into a novel class of natural products.

Efforts directed toward the synthesis of a basiliolide/transtaganolide model system are disclosed. A highly endo-selective intramolecular pyrone Diels−Alder (IMPDA) cycloaddition rapidly constructs the tricyclic core of the basiliolides and transtaganolides.
Visualizing the Interior Architecture of Focal Adhesions with High-Resolution Traction Maps

Focal adhesions (FAs) are micron-sized protein assemblies that coordinate cell adhesion, migration, and mechanotransduction. How the many proteins within FAs are organized into force sensing and transmitting structures is poorly understood. We combined fluorescent molecular tension sensors with super-resolution light microscopy to visualize traction forces within FAs with <100 nm spatial resolution. We find that αvβ3 integrin selectively localizes to high force regions. Paxillin, which is not generally considered to play a direct role in force transmission, shows a higher degree of spatial correlation with force than vinculin, talin, or α-actinin, proteins with hypothesized roles as force transducers. These observations suggest that αvβ3 integrin and paxillin may play important roles in mechanotransduction.
Random insertion into a priority queue structure

The average number of levels that a new element moves up when inserted into a heap is investigated. Two probabilistic models under which such an average might be computed are proposed. A `Lemma of Conservation of Ignorance' is formulated and used in the derivation of an exact formula for the average in one of these models. It is shown that this average is bounded by a constant and its asymptotic behaviour is discussed. Numerical data for the second model are also provided and analyzed.
Physical Properties of Extended Emission-Line Regions in Active and Cooling-Flow Galaxies

This dissertation utilizes primarily optical observations of extended emission-line regions in active and cooling-flow galaxies to clarify the nature of this nebulosity and its underlying sources of energy. In particular, I employ case studies of Seyfert galaxies in order to elucidate nuclear properties as seen in light that is apparently scattered into our line of sight, and to provide direct measurements of emission-line intensity ratios resulting from a radially diluted, photoionizing continuum for comparison with theory. The apparent Seyfert 2 galaxy NGC 4388 displays a weak, spatially extended, broad-line emission that is most readily understood as scattered light from a hidden Seyfert 1 nucleus. IC 5135 exhibits both Seyfert 2 and starburst activity in its nucleus, and the influence of both can be traced in nuclear emission-line profiles as well as line-intensity ratios of spatially resolved nebulosity. I also report results bearing on star formation and the rate of mass accretion in the cluster cooloing-flow galaxy NGC 1275, as revealed from spectroscopy of the nebular filaments in this system. While preferential low-mass star formation has been invoked to reconcile high X-ray inferred accretion rates in cooling flows with a paucity of apparent cooled matter, data reported here reveal a site of high-mass star formation in material believed to arise from the flow. Detailed scrutiny of this region suggests, moreover, that the initial mass function of star formation in this locale is unlikely to be biased unusually toward low-mass star formation. These results provide additional evidence that the true rate of mass deposition may be less than implied by a simple interpretation of the X-ray data. The same data set is used to derive improved upper temperatures. The ability of these measurements to constrain the accretion rate is limited by exclusion of the galaxy center, which is host to a Seyfert nucleus. Finally, I present results of a narrow-band imaging survey of X-ray selected, early-type galaxies that are examined for evidence linking nebulosity in these sources to cooling-flow or weak Seyfert phenomena. These results suggest that optical nebulosity in these systems probably bears a multiparameter relationship to cooling flows, active nuclei, and accretion from external sources.
The temperature dependent photochemistry of 1-naphthyl azide

Abstract Photolysis of 1-naphthyl azide in the presence of diethylamine at −60° or −78°C gives moderate yields of adducts derived from trapping of tricyclic azirines. These adducts are formed in very low yield on photolysis at room temperature.
Synthesis of new long red absorbing porphyrins: Reactions of organolithiums on octaethylporphyrinone.

Abstract Reaction of Organo lithiums with Porphyrinone 1 , after further manipulations afforded porphyrin derivatives absorbing in the range of 690–860 nm.
Luminous Compact Blue Galaxies in the Local Universe

We use the KPNO International Spectroscopic Survey (KISS) for emission-line galaxies to identify and describe a sample of local analogs to the luminous compact blue galaxies (LCBGs) that are observed to be abundant at intermediate and high redshift. The sample is selected using criteria believed effective at isolating true examples of LCBGs: SBe(B band) < 21.0 mag arcsec-2, MB < -18.5 (for H0 = 75 km s-1 Mpc-1), and B - V < 0.6. In addition, all LCBG candidates presented are selected to have star formation as their dominant form of activity. We examine the properties of our LCBGs and compare them with those of other KISS star-forming galaxies of the same absolute magnitude range. We find that the KISS LCBGs lie on the extreme end of a fairly continuous distribution of "normal" star-forming galaxies in the plane of surface brightness versus color. This result differs from the results of previous studies that show LCBGs at higher z to be more separate from the "normal" (usually nonactive) galaxies with which they are compared. On average, LCBGs have a higher tendency to emit detectable flux in the radio continuum; have higher Hα luminosities by a factor of 1.6, indicating strong star formation activity; and have slightly lower than expected metal abundances based on the luminosity-metallicity relation for KISS galaxies. We calculate the volume density of our low-z (z < 0.045) sample to be 5.4 × 10-4 h Mpc-3, approximately 4 times lower than the volume density of the LCBGs at 0.4 < z < 0.7 and ~10 times lower than the volume density of the population at 0.7 < z < 1.0.
Elastic Theory Has Zero Radius of Convergence.

In nonlinear elastic theory, the inverse bulk modulus $K$, for example, depends on the compression $P$: $1/K(P){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}c}_{0}{+c}_{1}{P+c}_{2}{P}^{2}+\ensuremath{\cdots}{+c}_{n}{P}^{n}+\ensuremath{\cdots}$ . Elastic materials that allow cracks are unstable at finite temperature with respect to fracture under a stretching load. As a result, the above power series has zero radius of convergence: it is an asymptotic series. For a two-dimensional isotropic elastic medium allowing cracks we compute the asymptotic form ${c}_{n+1}/{c}_{n}\ensuremath{\rightarrow}{\mathrm{Cn}}^{1/2}$ as $n\ensuremath{\rightarrow}\ensuremath{\infty}$. We present an explicit formula for $C$ as a function of temperature and material properties.