cssi/SciSciGPT-SciSciNet huggingface dataset:
An Efficient Synthesis of N-(Hetero)arylcarbazoles: Palladium-Catalyzed Coupling Reaction between (Hetero)aryl Chlorides and N-Carbazolylmagnesium Chloride

An efficient method for the synthesis of N-(hetero)arylcarbazoles, useful compounds for functional materials, is reported. Various (hetero)aryl chlorides reacted with N-carbazolylmagnesium chloride in the presence of a palladium catalyst (0.05 to 0.2 mol%) prepared from allylpalladium(II) chloride dimer {[PdCl(allyl)]2} and di-tert-butyl(2,2-diphenyl-1-methylcyclopropan-1-yl)phosphine (cBRIDP) under mild conditions (110 °C) in a short period of time (15 min to 2 h) to give N-(hetero)arylcarbazoles in high yields. The reactions of bromochlorobenzenes proceeded in favour of the bromo group to afford N-(chlorophenyl)carbazoles in a highly selective manner. Functional materials for use in organic light-emitting diodes, such as mCP, 26mcPy, CBP and TCB, were also obtained in high yields within 15 min by the reaction of (hetero)aryl polyhalides. Optimization of the reaction conditions and a postulated catalytic cycle for the reaction are also discussed.
What the Epistemic Account of Vagueness Means for Legal Interpretation

This paper explores what the epistemic account of vagueness (“epistemicism”) means for theories of legal interpretation. The thesis of epistemicism is that vague statements are true or false even though it is impossible to know which. I argue that if epistemicism is accepted within the domain of the law, then the following three conditions must be satisfied: (1) Interpretative reasoning within the law must adhere to the principle of bivalence and the law of excluded middle, (2) interpretative reasoning within the law must construe vague statements as an epistemic phenomenon, and (3) epistemicism must be expanded to include normative considerations in order to account for legal theories that are consistent with the first two conditions. The first two conditions are internal to a particular theory of legal interpretation, while the third condition is external to a particular theory of legal interpretation. My conclusion shows that there are legal theories that are internally consistent with the fundamental features of epistemicism. However, within the domain of law—and specifically in the case of legal theories that are internally consistent with epistemicism—I show that vagueness cannot be explained simply by our ignorance of the meaning and use of vague expressions. Rather, epistemicism must also account for ignorance of the requisite normative considerations in legal theories with which it is otherwise consistent.
The unchanging circumgalactic medium over the past 11 billion years

This paper examines how the circumgalactic medium (CGM) evolves as a function of time by comparing results from different absorption-line surveys that have been conducted in the vicinities of galaxies at different redshifts. Despite very different star formation properties of the galaxies considered in these separate studies and different intergalactic radiation fields at redshifts between z ≈ 2.2 and z ∼ 0, I show that both the spatial extent and mean absorption equivalent width of the CGM around galaxies of comparable mass have changed little over this cosmic time interval.
Development of a Silicon-Based Electron Beam Transmission Window for Use in a KrF Excimer Laser System

The Princeton Plasma Physics Laboratory (PPPL), in collaboration with the Naval Research Laboratory (NRL), is currently investigating various novel materials (single crystal silicon, , and ) for use as electron-beam transmission windows in a KrF excimer laser system. The primary function of the window is to isolate the active medium (excimer gas) from the excitation mechanism (field-emission diodes). Chosen window geometry must accommodate electron energy transfer greater than 80% (750 keV), while maintaining structural integrity during mechanical load (1.3 to 2.0 atm base pressure differential, approximate 0.5 atm cyclic pressure amplitude, 5 Hz repetition rate) and thermal load across the entire hibachi area (approximate 0.9 W {center_dot} cm superscript ''-2''). In addition, the window must be chemically resistant to attack by fluorine free-radicals (hydrofluoric acid, secondary). In accordance with these structural, functional, and operational parameters, a 22.4 mm square silicon prototype window, coated with 500 nm thin-film silicon nitride (Si{sub 3}N{sub 4}), has been fabricated. The window consists of 81 square panes with a thickness of 0.019 mm {+-} 0.001 mm. Stiffened (orthogonal) sections are 0.065 mm in width and 0.500 mm thick (approximate). Appended drawing (Figure 1) depicts the window configuration. Assessment of silicon (and silicon nitride) materialmore » properties and CAD modeling and analysis of the window design suggest that silicon may be a viable solution to inherent parameters and constraints.« less
Liquidation in Limit Order Books with Controlled Intensity

We consider a framework for solving optimal liquidation problems in limit order books. In particular, order arrivals are modeled as a point process whose intensity depends on the liquidation price. We set up a stochastic control problem in which the goal is to maximize the expected revenue from liquidating the entire position held. We solve this optimal liquidation problem for power-law and exponential-decay order book models explicitly and discuss several extensions. We also consider the continuous selling (or fluid) limit when the trading units are ever smaller and the intensity is ever larger. This limit provides an analytical approximation to the value function and the optimal solution. Using techniques from viscosity solutions we show that the discrete state problem and its optimal solution converge to the corresponding quantities in the continuous selling limit uniformly on compacts.
Monetary Policy in a Low‐Inflation Environment: Developing a State‐Contingent Price‐Level Target

A number of academic studies find that either price-level targeting or temporary above-average inflation are nearly optimal policies to address a liquidity trap crisis. Still, central bankers and the public generally question whether even a temporarily higher inflation rate could be beneficial in addressing a liquidity trap or could be consistent with price stability over the longer term. At the same time, however, the Federal Reserve's projections for high unemployment and low inflation do not seem to be consistent with the best monetary policies to address the Fed's dual mandate responsibilities. Accordingly, it is useful to seriously discuss these potentially beneficial alternative policies.
Identification of Peer Effects with Missing Peer Data: Evidence from Project STAR*

This article studies peer effects on student achievement among first graders randomly assigned to classrooms in Tennessee's Project STAR. The analysis uses previously unexploited pre-assignment achievement measures available for 60% of students. Data are not missing at random, making identification challenging. This study develops and applies new ways to identify peer effects in the presence of missing data, which incorporate knowledge of how groups form. Estimates suggest sizeable positive effects of mean peer lagged achievement on average. Analysis of a common peer-effects estimator implies caution is warranted in interpreting many peer-effect estimates extant in the literature. Language: en
The Role of Occupational Pension Funds in Mauritius

Mauritius belongs to a select group of developing countries where contractual savings-savings with insurance companies and pension funds-exceed 40 percent of GDP and represent a major potential force in the local financial system. Pension funds account for 75 percent of contractual savings. Contractual savings institutions invest in government securities, housing loans, corporate securities, real estate and bank deposits. They currently hold 35 percent of government securities and also account for 36 percent of total outstanding housing loans.Given their strong demand for long-duration assets, they can stimulate the issue of long-term government bonds (both inflation-linked and zero-coupon) and the development of corporate debentures, mortgage bonds, and mortgage-backed securities.Mauritius has a balanced and well-managed multipillar pension system. In addition to several public components, such as the Basic Retirement Pension, the National Pensions Fund (NPF), the National Savings Fund, and the Civil Service Pension Scheme, there are over 1,000 funded occupational pension schemes that play an increasingly important part in the whole system. The funded schemes are divided into two main groups-those insured and/or administered by insurance companies, and those that are self-administered and are registered with the Registrar of Associations. Coverage of the funded schemes is estimated at about 10 percent of the labor force. Together with the unfunded civil service scheme, occupational pension schemes cover about 100,000 employees or 20 percent of the labor force. All types of pension funds, including the public ones, report low operating costs. This reflects the absence of marketing and selling costs and, in the case of large private pension funds, the assumption of some costs by sponsoring employers. The investment performance of the self-administered funds was less than fully satisfactory in the late 1990s, reflecting poor returns on the local and foreign equity markets. Funds insured or administered by insurance companies as well the NPF performed better during this period because of their heavier allocations in government securities and housing loans. However, over a longer period, the private pension funds probably outperformed the NPF. The regulatory framework, though fragmented, is not unreasonable. It has many important provisions, such as observance of internationally acceptable accounting and actuarial standards and minimum vesting and portability rules, and it does not impose prescribed limits on investments. However, consolidation and modernization of the regulatory framework is required, while supervision, which is currently nonexistent, needs to be developed and to be proactive.
Calibrating Nested Sensor Arrays With Model Errors

We consider the problem of direction of arrival (DOA) estimation based on a nonuniform linear nested array, which is known to provide $O(N^2)$ degrees of freedom (DOFs) using only $N$ sensors. Both subspace-based and sparsity-based algorithms require certain modeling assumptions, e.g., exactly known array geometry, including sensor gain and phase. In practice, however, the actual sensor gain and phase are often perturbed from their nominal values, which disrupts the existing DOA estimation algorithms. In this paper, we investigate the self-calibration problem for perturbed nested arrays, proposing corresponding robust algorithms to estimate both the model errors and the DOAs. The partial Toeplitz structure of the covariance matrix is employed to estimate the gain errors, and the sparse total least squares (STLS) is used to deal with the phase error issue. In addition, we provide the Cramer-Rao bound (CRB) to analyze the robustness of the estimation performance of the proposed approaches. Furthermore, we extend the calibration strategies to general nonuniform linear arrays. Numerical examples are provided to verify the effectiveness of the proposed strategies.
The Anatomy of Start-Stop Growth

Abstract This paper investigates the remarkable extremes of growth experiences within countries and the changes that occur across growth transitions. We find two main results. First, virtually all but the very richest countries experience both growth miracles and failures over substantial periods. Second, growth accelerations and collapses are asymmetric phenomena. Collapses typically feature reduced investment amidst increasing price instability, whereas growth takeoffs are primarily associated with large expansions in international trade. The results show that even very poor countries regularly grow rapidly, but sustaining growth is difficult and may pose a very different set of challenges than starting it.
Double MV cycles and the Naito–Sagaki–Saito crystal

Abstract The theory of MV cycles associated to a complex reductive group G has proven to be a rich source of structures related to representation theory. We investigate double MV cycles, which are analogues of MV cycles in the case of an affine Kac–Moody group. We prove an explicit formula for the Braverman–Finkelberg–Gaitsgory (2006) [7] crystal structure on double MV cycles, generalizing a finite-dimensional result of Baumann and Gaussent (2008) [2] . As an application, we give a geometric construction of the Naito–Sagaki–Saito [23] crystal via the action of S L n on Fermionic Fock space. In particular, this construction gives rise to an isomorphism of crystals between the set of double MV cycles and the Naito–Sagaki–Saito crystal. As a result, we can independently prove that the Naito–Sagaki–Saito crystal is the B ( ∞ ) crystal. In particular, our geometric proof works in the previously unknown case of s l 2 .
The 27-28 October 1986 FIRE IFO cirrus case study : cloud optical properties determined by high spectral resolution lidar

The High Spectral Resolution Lidar (HSRL) was operated from a roof-top site in Madison, Wisconsin. The transmitter configuration used to acquire the case study data produces about 50 mW of ouput power and achieved eye-safe, direct optical depth, and backscatter cross section measurements with 10 min averaging times. A new continuously pumped, injection seeded, frequency doubled Nd:YAG laser transmitter reduces time-averaging constraints by a factor of about 10, while improving the aerosol-molecular signal separation capabilities and wavelength stability of the instrument. The cirrus cloud backscatter-phase functions have been determined for the October 27-28, 1986 segment of the HSRL FIRE dataset. Features exhibiting backscatter cross sections ranging over four orders of magnitude have been observed within this 33 h period. During this period, cirrus clouds were observed with optical thickness ranging from 0.01 to 1.4. The altitude relationship between cloud top and bottom boundaries and the optical center of the cloud is influenced by the type of formation observed.
Why is it important to simultaneously use more than one chiroptical spectroscopic method for determining the structures of chiral molecules

In recent years, four different chiroptical spectroscopic methods, namely vibrational circular dichroism, vibrational Raman optical activity, electronic circular dichroism, and optical rotatory dispersion, have become popular for establishing the absolute configuration and predominant conformations of chiral molecules in solution state. Many individual laboratories normally utilize only one of these methods to derive the molecular structural information. Although that approach may be satisfactory for most of the molecules studied, it is to be noted that in some instances a single method can give ambiguous conclusions or may not give complete structural information. This article summarizes the situations where simultaneous use of more than one chiroptical spectroscopic method is required to obtain molecular structural information and recommends the routine application of more than one chiroptical spectroscopic method for any given molecule. Chirality, 2008. © 2007 Wiley-Liss, Inc.
Tailoring thermal emission via Q matching of photonic crystal resonances

We develop a model for predicting the thermal emission spectrum of a two-dimensional metallic photonic crystal for arbitrary angles based on coupled-mode theory. Calculating the appropriate coupled-mode parameters over a range of geometrical parameters allows one to tailor the emissivity spectrum to a specific application. As an example, we design an emitter with a step-function cutoff suppressing long-wavelength emission, which is necessary for high-efficiency thermophotovoltaic systems. We also confirm the accuracy of the results of our model with finite-difference time-domain simulations.
The isolation and characterization of agardhilactone, a novel oxylipin from the marine red alga Agardhiella subulata

Abstract A novel tricyclic oxylipin containing δ-lactone, cyclopentane and epoxide rings and a conjugated diene, has been isolated from the marine red alga Agardhiella subulata. The structure, including partial stereochemistry, was determined by NMR and GC-MS analysis of menthoxycarbonyl derivatives.
A New Analysis of the O VI Emitting Nebula Around KPD 0005+5106

We present observations of O VI {lambda}1032 emission around the helium white dwarf KPD 0005+5106 obtained with the Far Ultraviolet Spectroscopic Explorer. Previously published data, reprocessed with an updated version of the calibration pipeline, are included along with new observations. The recent upward revision of the white dwarf's effective temperature to 200,000 K has motivated us to re-analyze all the data. We compare observations with photoionization models and find that the density of the O VI nebula is about 10 cm{sup -3}, and that the stellar flux must be attenuated by about 90% by the time it impinges on the inner face of the nebula. We infer that this attenuation is due to circumstellar material ejected by KPD 0005+5106 earlier in its evolution.
Direct oxidative amidation of aromatic aldehydes using aqueous hydrogen peroxide in continuous flow microreactor systems

A practical and economical protocol has been developed for the direct oxidative amidation of aromatic aldehydes with secondary amines to synthesize amides in a single operation under mild conditions within 15–40 min. The utilization of aqueous hydrogen peroxide affords a clean synthetic route. No catalysts or promoting reagents are required.
The enzyme-mediated direct reversal of a dithymine photoproduct in germinating endospores.

Spore photoproduct lyase (SPL) repairs a special thymine dimer, 5-thyminyl-5,6-dihydrothymine, which is commonly called spore photoproduct, or SP, in germinating endospores. SP is the exclusive DNA photo-damaging product found in endospores; its generation and swift repair by SPL are responsible for the spores’ extremely high UV resistance. Early in vivo studies suggested that SPL utilizes a direct reversal strategy to repair SP in the absence of light. Recently, it has been established that SPL belongs to the radical S-adenosylmethionine (SAM) superfamily. The enzymes in this superfamily utilize a tri-cysteine CXXXCXXC motif to bind a [4Fe-4S] cluster. The cluster provides an electron to the S-adenosylmethionine (SAM) to reductively cleave its C5'-S bond, generating a reactive 5'-deoxyadenosyl (5'-dA) radical. This 5'-dA radical abstracts the proR hydrogen atom from the C6 carbon of SP to initiate the repair process; the resulting SP radical subsequently fragments to generate a putative thymine methyl radical, which accepts a back-donated H atom to yield the repaired TpT. The H atom donor is suggested to be a conserved cysteine141 in B. subtilis SPL; the resulting thiyl radical likely interacts with a neighboring tyrosine99 before oxidizing the 5'-dA to 5'-dA radical and, subsequently, regenerating SAM. These findings suggest SPL to be the first enzyme in the large radical SAM superfamily (>44,000 members) to utilize a radical transfer pathway for catalysis; its study should shed light on the mechanistic understanding of the SAM regeneration process in other members of the superfamily.
Scratchpad memories at Honeywell: past, present, and future

The computer industry, during its short life of approximately 20 years, has seen many innovations, evolutionary trends and developments, and has even accommodated several major revolutionary technological breakthroughs. One of these revolutionary-evolutionary developments has been the increasing use of small memories as scratchpads.
Neuronal and glial processes in neuropathology.

The cells of the nervous system can be characterized by their well formed cell processes and by the cell-to-cell relationships that they form. The neuron displays essentially cylindrical processes, i.e. round in cross section, which form synaptic junctions with either other neuronal processes or with other target cells. A variety of pathologic processes involve alterations of either the neuronal processes or the synapses. On the other hand, the functional, peripheral portions of the processes of the glial cells are largely sheet-like in nature. Frequently, the connecting link between the functional sheet-like process and the glial cell body is round in section like the neuronal process, but the peripheral parts of the process are not. Thus, the interfascicular oligodendroglial cell elaborates several sheet-like processes, each of which forms a segment of the myelin sheath. An unusual cell junction, the transverse bands is present at the interface of the oligodendroglial process and the axonal surface. Numerous pathological alterations occur in the oligodendroglial cells that may lead to demyelination. These may sometimes be the result of defects in the glial process, conceivably in the transverse bands or the tight junction which isolates the interlamellar spaces from the extracellular space. Finally, the astrocytes, too, form elaborate sheet-like processes that separate most of the central nervous system from the mesodermal and mesenchymal tissues as well as surround some neuronal surfaces, including certain synapses. Gap junctions and other adhesive devices are found between astrocytic processes. Several pathological conditions are characterized by defects or anomalies in the astrocytic periphery.
Composition and origin of lithic fragments and glasses in apollo 11 samples

Approximately 100 glasses and 52 lithic fragments from Apollo 11 lunar fines and microbreccias were analyzed with the electron microprobe. Ranges in bulk composition of lithic fragments are considerably outside the precision (<±1%) and accuracy (±2–5%) of the broad electron beam technique. Results of this study may be summarized as follows: i) A large variety of rock types different from the hand specimens (basalt) were found among the lithic fragments, namely anorthosites, troctolitic and noritic anorthosites, troctolites, and norites (different from Apollo 12 norites). ii) In analogy to the hand specimens, the basaltic lithic fragments may be subdivided into low-K and high-K groups, both of which extend considerably in composition beyond the hand specimens. iii) Glasses were divided into 6 groups: Group 1 are the compositional analogs of the anorthositic-troctolitic lithic fragments and were apparently formed in single-stage impact events directly from parent anorthosites and troctolites. iv) Group 2 glasses are identical in composition to Apollo 12 KREEP glass and noritic lithic fragments, but have no counterparts in our Apollo 11 lithic fragment suite. Occurrence of KREEP in Apollo 11,12, and 14 samples is indicative of its relatively high abundance and suggests that the lunar crust is less depleted in elements that are common in KREEP (e.g. K, rare earths, P) than was originally thought on the basis of Apollo 11 basalt studies. v) Group 3 glasses are the compositional analogs of the basaltic lithic fragments, but low-K and high-K glasses cannot be distinguished because of loss of K (and Na, P) by volatilization in the vitrification process. vi) Group 4 glasses have no compositional analogs among the lithic fragments and were probably derived from as yet unknown Fe-rich, moderately Ti-rich, Mg-poor basalts. vii) Group 5 (low Ti-high Mg peridotite equivalent) and 6 (ilmenite peridotite equivalent) glasses have no counterparts among the Apollo 11 lithic fragments, but rock equivalents to group 5 glasses were found in Apollo 12 samples. Group 6 glasses are abundant, have narrow compositional ranges, and are thought to be the products of impact melting of an as yet unrecognized ultramafic rock type. iix) The great variety of igneous rocks (e.g. anorthosites, troctolites, norites, basalts, peridotites) suggests that large scale melting or partial melting to considerable depth must have occurred on the moon.
An Improved Limit on Pauli-Exclusion-Principle Forbidden Atomic Transitions

We have examined the atomic theory behind recent constraints on the violation of the Pauli Exclusion Principle derived from experiments that look for X-rays emitted from conductors while a large current is present. We also re-examine the assumptions underlying such experiments. We use the results of these studies to assess pilot measurements to develop an improved test of the Principle. We present an improved limit of $\frac{1}{2}\beta^{2} < 2.6\times10^{-39}$ on the Pauli Exclusion Principle. This limit is the best to date for interactions between a system of fermions and a fermion that has not previously interacted with that given system. That is, for systems that do not obviously violate the Messiah-Greenberg symmetrization-postulate selection rule.
A SURVEY OF BOTT–TAUBES INTEGRATION

It is well-known that certain combinations of configuration space integrals defined by Bott and Taubes [11] produce cohomology classes of spaces of knots. The literature surrounding this important fact, however, is somewhat incomplete and lacking in detail. The aim of this paper is to fill in the gaps as well as summarize the importance of these integrals.
Sudden stops, banking crises and investment collapses in emerging markets

Abstract We evaluate whether financial openness leaves emerging market economies vulnerable to the adverse effects of capital reversals (“sudden stops”) on domestic investment. We investigate this claim in a broad sample of emerging markets during the period 1976–2002. If the banking sector does not experience a systemic crisis, sudden stop events fail to have a significant impact on investment. Bank crises, on the other hand, have a significant negative effect on investment even in the absence of a contemporaneous sudden stop crisis. We also find that openness to capital flows worsens the adverse impact of banking crises on investment. Our results provide statistical support for the policy view that a strong banking sector which can withstand the negative fallout of capital flight is essential for countries that open their economies to international financial flows.
Normal-mode selectivity in ultrafast Raman excitations in C 60

Ultrafast Raman spectra are a powerful tool to probe vibrational excitations, but inherently they are not normal-mode specific. For a system as complicated as ${\mathrm{C}}_{60}$, there is no general rule to target a specific mode. A detailed study presented here aims to investigate normal-mode selectivity in ${\mathrm{C}}_{60}$ by an ultrafast laser. To accurately measure mode excitation, we formally introduce the kinetic-energy-based normal-mode analysis which overcomes the difficulty with the strong lattice anharmonicity and relaxation. We first investigate the resonant excitation and find that mode selectivity is normally difficult to achieve. However, for off-resonant excitations, it is possible to selectively excite a few modes in ${\mathrm{C}}_{60}$ by properly choosing an optimal laser pulse duration, which agrees with previous experimental and theoretical findings. Going beyond the phenomenological explanation, our study shines new light on the origin of the optimal duration: The phase matching between the laser field and mode vibration determines which mode is strongly excited or suppressed. This finding is very robust and should be a useful guide for future experimental and theoretical studies in more complicated systems.
CuH-catalyzed enantioselective intramolecular reductive aldol reactions generating three new contiguous asymmetric stereocenters.

Treatment of β,β-disubstituted-α,β-unsaturated ketones bearing a ketone residue with in situ generated, catalytic CuH ligated by a nonracemic ligand leads to three newly created adjacent chiral centers. Excellent deʼs and eeʼs are obtained for several examples studied.
Does self-employment increase the economic well-being of low-skilled workers?

Low-skilled workers do not fare well in today’s skill intensive economy and their opportunities continue to diminish. Utilizing data from the survey of income and program participation, this paper provides an analysis of the economic returns to business ownership among low-skilled workers and addresses the essential question of whether self-employment is a good option for low-skilled individuals that policymakers might consider encouraging. The analysis reveals substantial differences in the role of self-employment among low-skilled workers across gender and nativity—women and immigrants are shown to be of particular importance from both the perspectives of trends and policy relevance. We find that, although the returns to low-skilled self-employment among men is higher than among women, the analysis shows that wage/salary employment is a more financially rewarding option for most low-skilled workers.
Standard model vacua for two-dimensional compactifications

We examine the structure of lower-dimensional standard model vacua for two-dimensional compactifications (on a 2D torus and on a 2D sphere). In the case of the torus we find a new standard model vacuum for a large range of neutrino masses consistent with experiment. Quantum effects play a crucial role in the existence of this vacuum. For the compactification on a sphere the classical terms dominate the effective potential for large radii and a stable vacuum is achieved only by introducing a large magnetic flux. We argue that there are no two-dimensional standard model vacua for compactifications on a surface of genus greater than one.
Antenna analysis and boundary conditions for alfven wave studies in Tokamaks

Previous studies of Alfven wave heating which employed kinetic theory are extended in order to take into account antenna configurations, in cylindrical geometry, consisting of arbitrary shell currents and their associated radial feeders. For each Fourier component of the form exp [-i(lζ-mθ)], the shell current consists of a divergence-free part having the helicity of the mode (l, m), plus an orthogonal part requiring the feeders. It is shown, both analytically and by including the full current in the numerical code, that only the divergence-free part of the current contributes significantly to the plasma response and antenna loading. The important effect of the feeders is to cancel the contribution from the surface current perpendicular to the helicity. This explicitly verifies results reported previously.
Energy of the Taub Cosmological Solution

We calculate the total energy of Taub’s 1951 exact solution for a Bianchi type-IX geometry using several different energy-localization procedures, including the prescriptions of Einstein, Papapetrou, Landau–Lifshitz and Moller. We compare these results to those for other anisotropic geometries, and comment on their relationship to Rosen’s conjecture about the total energy of the universe.
Recent developments in glycosyl urea synthesis

The area of sugar urea derivatives has received considerable attention in recent years because of the unique structural properties and activities that these compounds display. The urea-linkage at the anomeric center is a robust alternative to the naturally occurring O- and N-glycosidic linkages of oligosaccharides and glycoconjugates, and the natural products that have been identified to contain these structures show remarkable biological activity. While methods for installing the β-urea-linkage at the anomeric center have been around for decades, the first synthesis of α-urea glycosides has been much more recent. In either case, the selective synthesis of glycosyl ureas can be quite challenging, and a mixture of α- and β-isomers will often result. This paper will provide a comprehensive review of the synthetic approaches to α- and β-urea glycosides and examine the structure and activity of the natural products and their analogues that have been identified to contain them.
Inertial cavitation and single–bubble sonoluminescence

Sonoluminescence is investigated experimentally from the perspective of the dynamics of a single inertial cavitation bubble levitated in an acoustic sound field. The discussion includes bubble levitation, the inertial cavitation threshold, the parameter space in which stable singlendash;bubble sonoluminescence is observed, measurements of the acoustic and electromagnetic emissions from a sonoluminescence bubble, and the effects of impurities on the quality of the light emission from sonoluminescence bubbles. Comparisons are also made between sonoluminescence from a single bubble and sonoluminescence from a cavitation field.
An empirical examination of the influence of industry and firm drivers on the rate of internationalization by firms

Abstract Foreign direct investment made by firms globally rose by 40 percent to $315 billion in 1995 compared with the previous year. In spite of the apparent importance of globalization, very little research has examined the factors with potential to influence the rate of internationalization of firms. Using 158 large U.S.-based multinational firms drawn from seven different industries, this study explains about 24 percent of the variance of the rate of internationalization. Results indicate that global market growth rate, domestic market growth rate, relative size of domestic market to international market, employee productivity, administrative investments, as well as new plant and equipment influence the rate of internationalization of firms.
Chern-Simons forms, Mickelsson-Faddeev algebras and the p-branes

Abstract In string theory, nilpotence of the BRS operator δ for the string functional relates the Chern-Simons term in the gauge-invariant antisymmetric tensor field strength to the central term in the Kac-Moody algebra. We generalize these ideas to p -branes with odd p and find that the Kac-Moody algebra for the string becomes the Michelsson-Faddeev algebra for the p -brane.
Synthesis of 9-fluorenylmethoxycarbonyl-protected amino aldehydes

Abstract 9-Fluorenylmethoxycarbonyl-protected amino aldehydes could be efficiently prepared in good yields by using two methods: (i) NaBH 4 reduction of Fmoc-protected mixed anhydrides, followed by the Swern oxidation of the alcohols; and (ii) LiAlH 4 reduction of Fmoc-protected amino acid Weinreb amides. Both methods afforded comparable overall synthetic yields (70–80%).
Imaging the Circumstellar Environments of Young Binaries in Southern Star-Forming Regions

A sample of 14 pre–main-sequence visual binary systems in southern star-forming regions were imaged at 2 μm with the Keck I telescope to search for tertiary companions, scattered-light disks, and compact nebulae at linear scales of 5–100 AU. Speckle holography was used to produce images with diffraction-limited resolution and high dynamic range, and photometry in four filters between J (1.25 μm) and L' (3.8 μm) was used to provide a diagnostic of the infrared excess. Of the 14 visual binary systems studied, nine contain components that show evidence for resolved structure. Two of them (WSB 18 and B59-1) have well-resolved tertiary companions separated from the primary stars by ~100 mas. The remainder are only marginally resolved at the diffraction limit of the telescope. Sz 116, AS 205, Elias 2-22, ESO Hα 282, and B59-2 each have one component that is marginally resolved along one axis and unresolved on the perpendicular axis, consistent with tertiaries at separations between ~6 and 40 mas. If all these systems are hierarchical triples, then fully half the nominal binaries in the sample are triple. The primaries in Elias 2-49 and WSB 71 are marginally resolved along all position angles, suggesting the presence of dust halos. No disks were unambiguously detected in the sample.
Chemistry of 1-Alkoxy-1-glycosyl Radicals: The Manno- and Rhamnopyranosyl Series. Inversion of α- to β-Pyranosides and the Fragmentation of Anomeric Radicals

The formation and stereoselective quenching of 1-mannopyranosyl radicals by a tributyltin hydride-mediated intramolecular 1,5-hydrogen abstraction sequence is described. A competing process is 1,4-hydrogen atom abstraction leading principally to glucopyran-2-ulosides. Fragmentation of the anomeric radical resulting in the formation of ring opened products is a problem in certain series. The chemistry is dictated to a considerable extent by the nature of the protecting groups employed with the 4,6-benzylidene series and, for rhamnose, the Ley 3,4-dispiroketal, being particularly susceptible to the 1,4-hydrogen atom abstraction but less to the fragmentation. Photochemical conditions are described, in which these side reactions are practically eliminated, and applied to the inversion of an α- to a β-mannoside in a disaccharide.
Patient-controlled analgesia: Finding a balance between cost and comfort

Purpose. Despite the growing movement in acute pain management, acute postoperative pain continues to be undermanaged. Although numerous clinical practice guidelines for pain management have been published throughout the last 12 years, inadequate pain relief remains a significant health care issue. Insufficient dosage of analgesics is a common problem, and therapy for those patients still with pain represents a considerable health care dilemma. Summary. Patient-controlled analgesia (PCA) refers to a process in which patients determine when and how much medication they receive, regardless of analgesic technique. Patient-controlled modalities using intravenous (i.v.) and epidural routes have dramatically improved postoperative pain management. PCA has emerged as an effective way for patients to manage their pain, allowing self-administration of small doses of analgesics to maintain a certain level of pain control. PCA is most commonly delivered via an intravenous or epidural route, and while patient satisfaction is higher with PCA than with conventional methods of analgesic administration, the invasiveness, costs, health care resources, and risk of errors associated with currently available modalities may limit their utility. The overall effectiveness of any analgesic technique depends on both the degree of pain relief and the incidence of side effects or complications. These adverse events of acute pain complicate postoperative recovery and may lead to longer hospital stays, as well as increased health care costs. Several new PCA modalities are being developed to address these limitations. These systems deliver drugs through a variety of routes (for example, transdermal). Most notable is a self-contained, credit card-sized fentanyl transdermal patient-activated system. It provides pain relief therapeutically equivalent to that of standard regimen of morphine i.v. PCA, with pharmacokinetics similar to those of intravenous fentanyl infusion. Fentanyl HCl patient-activated transdermal systems (PATS) may be an effective, noninvasive alternative to currently available i.v. PCA modalities. Whichever drug or device is utilized, the overall success relies on the expert supervision of nurses, pharmacists, and anesthesiologists in an acute pain service. Conclusion. Current PCA techniques using i.v. or epidural administration have limitations. Development of new technology offering alternative routes for PCA administration is at the forefronts of PCA research.
Supernova neutrino detection in Borexino

Abstract We calculated the expected neutrino signal in Borexino from a typical Type II supernova at a distance of 10 kpc. A burst of around 110 events would appear in Borexino within a time interval of about 10 s. Most of these events would come from the reaction channel ν e + p → e + + n , while about 30 events would be induced by the interaction of the supernova neutrino flux on 12C in the liquid scintillator. Borexino can clearly distinguish between the neutral-current excitations 12 C ( ν , ν ′ ) 12 C * (15.11 MeV) and the charged-current reactions 12 C ( ν e , e − ) 12 N and 12 C ( ν e , e + ) 12 B , via their distinctive event signatures. The ratio of the charged-current to neutral-current neutrino event rates and their time profiles with respect to each other can provide a handle on supernova and non-standard neutrino physics (mass and flavor oscillations).
Learning to Rank for Information Retrieval

This tutorial is concerned with a comprehensive introduction to the research area of learning to rank for information retrieval. In the first part of the tutorial, we will introduce three major approaches to learning to rank, i.e., the pointwise, pairwise, and listwise approaches, analyze the relationship between the loss functions used in these approaches and the widely-used IR evaluation measures, evaluate the performance of these approaches on the LETOR benchmark datasets, and demonstrate how to use these approaches to solve real ranking applications. In the second part of the tutorial, we will discuss some advanced topics regarding learning to rank, such as relational ranking, diverse ranking, semi-supervised ranking, transfer ranking, query-dependent ranking, and training data preprocessing. In the third part, we will briefly mention the recent advances on statistical learning theory for ranking, which explain the generalization ability and statistical consistency of different ranking methods. In the last part, we will conclude the tutorial and show several future research directions.
LONG-TERM STABLE EQUILIBRIA FOR SYNCHRONOUS BINARY ASTEROIDS

Synchronous binary asteroids may exist in a long-term stable equilibrium, where the opposing torques from mutual body tides and the binary YORP (BYORP) effect cancel. Interior of this equilibrium, mutual body tides are stronger than the BYORP effect and the mutual orbit semimajor axis expands to the equilibrium; outside of the equilibrium, the BYORP effect dominates the evolution and the system semimajor axis will contract to the equilibrium. If the observed population of small (0.1-10 km diameter) synchronous binaries are in static configurations that are no longer evolving, then this would be confirmed by a null result in the observational tests for the BYORP effect. The confirmed existence of this equilibrium combined with a shape model of the secondary of the system enables the direct study of asteroid geophysics through the tidal theory. The observed synchronous asteroid population cannot exist in this equilibrium if described by the canonical 'monolithic' geophysical model. The 'rubble pile' geophysical model proposed by Goldreich and Sari is sufficient, however it predicts a tidal Love number directly proportional to the radius of the asteroid, while the best fit to the data predicts a tidal Love number inversely proportional to the radius. This deviation from the canonicalmore » and Goldreich and Sari models motivates future study of asteroid geophysics. Ongoing BYORP detection campaigns will determine whether these systems are in an equilibrium, and future determination of secondary shapes will allow direct determination of asteroid geophysical parameters.« less
The Real Price of Housing and Money Supply Shocks: Time Series Evidence and Theoretical Simulations

Abstract I estimate the dynamic response of aggregate owner-occupied housing prices to money supply shocks and interpret these responses using a dynamic equilibrium model of the housing market that relies on the asset view of housing demand. Money supply shocks are identified empirically from a vector autoregression (VAR) using restrictions that are consistent with a wide class of theoretical models. Using monthly data, I find that money shocks have real effects on the housing market: both real housing prices and housing sales (new starts and existing homes) rise in the short-run in response to positive shocks to the money supply. Simulations of the theoretical model suggest that, for reasonable parameter values, the estimated price responses are generally consistent with the theory.
(1R,2S)-(+)-cis-1-Methoxycarbonyl-2-methylcyclobutane

An X-ray crystallographic structure determination for the related (R)-(−)-2-phenylglycinol derived amide demonstrates that (+)-cis-1-methoxycarbonyl-2-methylcyclobutane is the (1R,2S) isomer.
Modeling and simulations of collapse instabilities of microbeams due to capillary forces

We present modeling and analysis for the static behavior and collapse instabilities of doubly-clamped and cantilever microbeams subjected to capillary forces. These forces can be as a result of a volume of liquid trapped underneath the microbeam during the rinsing and drying process in fabrication. The model considers the microbeam as a continuous medium, the capillary force as a nonlinear function of displacement, and accounts for the mid-plane stretching and geometric nonlinearities. The capillary force is assumed to be distributed over a specific length underneath the microbeam. The Galerkin procedure is used to derive a reduced-order model consisting of a set of nonlinear algebraic and differential equations that describe the microbeams static and dynamic behaviors. We study the collapse instability, which brings the microbeam from its unstuck configuration to touch the substrate and gets stuck in the so-called pinned configuration. We calculate the pull-in length that distinguishes the free from the pinned configurations as a function of the beam thickness and gap width for both microbeams. Comparisons are made with analytical results reported in the literature based on the Ritz method for linear and nonlinear beam models. The instability problem, which brings the microbeam from a pinned to adhered configuration is also investigated. For this case, we use a shooting technique to solve the boundary-value problem governing the deflection of the microbeams. The critical microbeam length for this second instability is also calculated.
Combinatorial analogs of Brouwer's fixed-point theorem on a bounded polyhedron

Abstract In this paper, we present a combinatorial theorem on a bounded polyhedron for an unrestricted integer labelling of a triangulation of the polyhedron, which can be interpreted as an extension of the Generalized Sperner lemma. When the labelling function is dual-proper, this theorem specializes to a second theorem on the polyhedron, that is, an extension of Scarf's dual Sperner lemma. These results are shown to be analogs of Brouwer's fixed-point theorem on a polyhedron, and are shown to generalize other combinatorial theorems on bounded polyhedra as well. The paper also contains a pseudomanifold construction for a polyhedron and its dual that may be of interest to researchers in triangulations based on primal and dual polyhedra.
The Use of C3-symmetric Tripodal Ligands in Crystal Engineering

Abstract The use of chiral tripodal ligands in the assembly of non-centrosymmetric crystal lattice is illustrated with the triamide ligand tris[ N -( S )-(−)-(α)-methylbenzylcarbamoylmethyl]amine (H 3 1 S -mbz ). In the crystal phase, this tripodal ligand assembles into C 3 -symmetric chiral columns that are stabilized by hydrogen bonds and aryl–aryl interactions. Intercolumnar assembly is driven by the clustering of edge-to-face aryl and methyl-to-aryl interactions. Thrice deprotonation of H 3 1 S -mbz and binding of an Ni(II)–F moiety also produces a non-centrosymmetric lattice which is noteworthy for its six-fold symmetric open framework structure and the alignment of all the molecular Ni–F bonds in the lattice along the crystallographic c -axis. Crystal data: H 3 1 S -mbz crystallizes in the rhombohedral system, space group R 3 with cell dimensions a = b =22.352(5) A, c =4.882(1) A, α = β =90°, γ =120°, and Z =3; [NEt 4 ] 2 [Ni 1 S -mbz (F)] crystallizes in the hexagonal system, space group P 6 3 with cell dimensions a = b =12.0780(1) A, c =18.1231(1) A, α = β =90°, γ =120°, and Z =2.
Edge Detector Evaluation Using Empirical ROC Curves

We demonstrate a method for evaluating edge detector performance based on receiver operating characteristic (ROC) curves. Edge detector output is matched against ground truth to count true positive and false positive edge pixels. A detector's parameter settings are trained to give a best ROC curve on one image and then tested on separate images. We compute aggregate ROC curves based on 1 set of 50 object images and another set of 10 aerial images. We analyze the performance of 11 different edge detectors reported in the literature.