cssi/SciSciGPT-SciSciNet huggingface dataset:
Water transport through functionalized nanotubes with tunable hydrophobicity.

Molecular dynamics simulations are used to study the occupancy and flow of water through nanotubes comprised of hydrophobic and hydrophilic atoms, which are arranged on a honeycomb lattice to mimic functionalized carbon nanotubes (CNTs). We consider single-file motion of TIP3P water through narrow channels of (6,6) CNTs with varying fractions (f) of hydrophilic atoms. Various arrangements of hydrophilic atoms are used to create heterogeneous nanotubes with separate hydrophobic/hydrophilic domains along the tube as well as random mixtures of the two types of atoms. The water occupancy inside the nanotube channel is found to vary nonlinearly as a function of f, and a small fraction of hydrophilic atoms (f ≈ 0.4) are sufficient to induce spontaneous and continuous filling of the nanotube. Interestingly, the average number of water molecules inside the channel and water flux through the nanotube are less sensitive to the specific arrangement of hydrophilic atoms than to the fraction, f. Two different regimes are observed for the water flux dependence on f – an approximately linear increase in flux as a function of f for f < 0.4, and almost no change in flux for higher f values, similar to the change in water occupancy. We are able to define an effective interaction strength between nanotube atoms and water's oxygen, based on a linear combination of interaction strengths between hydrophobic and hydrophilic nanotube atoms and water, that can quantitatively capture the observed behavior.
Massive star formation in 100,000 years from turbulent and pressurized molecular clouds

Massive stars (with mass m* > 8 solar masses M⊙) are fundamental to the evolution of galaxies, because they produce heavy elements, inject energy into the interstellar medium, and possibly regulate the star formation rate. The individual star formation time, t*f, determines the accretion rate of the star; the value of the former quantity is currently uncertain by many orders of magnitude1,2,3,4,5,6, leading to other astrophysical questions. For example, the variation of t*f with stellar mass dictates whether massive stars can form simultaneously with low-mass stars in clusters. Here we show that t*f is determined by the conditions in the star's natal cloud, and is typically ∼105 yr. The corresponding mass accretion rate depends on the pressure within the cloud—which we relate to the gas surface density—and on both the instantaneous and final stellar masses. Characteristic accretion rates are sufficient to overcome radiation pressure from ∼100M⊙ protostars, while simultaneously driving intense bipolar gas outflows. The weak dependence of t*f on the final mass of the star allows high- and low-mass star formation to occur nearly simultaneously in clusters.
Some Composite Bearing and Seal Materials for Gas Turbine Applications—A Review

A review is given of the selection and tribological testing of materials for high-temperature bearings and seals. Plasma-sprayed composite coatings with favorable bribological properties from 25 to 900°C are discussed. The performance of these coatings in simple tribological bench tests is described. Examples are also given of their performance in high-speed sliding contact seals, as Stirling cylinder liner materials, and as backup lubricants for compliant foil gas bearings
Investigation of the mechanism of ammonia oxidation and oxygen exchange over vanadia catalysts using N-15 and O-18 tracer studies

Isotopic labeling studies in ammonia oxidation and oxygen exchange have been performed over unsupported vanadia catalysts having preferential exposure of different crystal planes. All catalysts were characterized using BET surface area measurement, X-ray diffraction, laser Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, 3-D imaging, and temperature-programmed adsorption/desorption/reduction techniques. Isotopic labeling studies have been performed under steady-state conditions by using {sup 16}O{sub 2} {r_arrow} {sup 18}O{sub 2}, NH{sub 3} + {sup 16}O{sub 2} {r_arrow} NH{sub 3} + {sup 18}O{sub 2}, and {sup 14}NH{sub 3} + O{sub 2} {r_arrow} {sup 15}NH{sub 3} + O{sub 2} switches. The experimentally obtained transients have been compared to those calculated through a mathematical simulation. Results of the oxygen exchange experiments show that, although there is no formation of the cross-labeled oxygen, gaseous oxygen actively exchanges with lattice oxygen on all crystal planes of V{sub 2}O{sub 5}. The oxygen located on the (010) basal plane seems to be more reactive whereas the replenishment of oxygen from the catalyst bulk appears to be faster towards the side planes of the V{sub 2}O{sub 5} crystals. The kinetic experiments performed for ammonia oxidation reaction studies suggest that there are at least two types of sites on the (010) planemore » responsible for this reaction, one leading to NO formation and the other one leading to N{sub 2} and N{sub 2}O formation. The type of adsorbed ammonia species formed are thought to be controlled by the immediate environment of the V = O species on the surface. 48 refs., 12 figs., 3 tabs.« less
The MIT magnetic-core memory

One recent development which is significantly raising the reliability of today's high-speed automatic digital computer is the multicoordinate magnetic-core memory. Two banks of 32 by 32 by 17 magnetic-core memory have been in full-time operation in the Whirlwind I Computer for some months. A description of the units and of the tests and operational data available on them will be preceded by a short review of operating principles of this type of memory.
PAC Congressional Election Campaign Contributions and Other Political or Economic Influences on the Voter Participation Rate

This study empirically investigates the potential impact of political action committee (PAC) election campaign contributions and other factors on the aggregate voter participation rate in the United States. For the study period 1960-1998, the aggregate voter participation rate appears to have been positively and significantly affected by the opportunity to vote in presidential elections and by the Vietnam War, as well as by "excessive" inflation and slow real GDP growth . The latter two findings of this study appear to be unique to this literature. In addition, the Watergate scandal and increased public dissatisfaction with government appear to have significantly discouraged voter participation. Finally, there appears to be strong evidence that PAC congressional election campaign contributions may have also acted to reduce the voter participation rate over the study period, a finding that also is unique to this study.
A new analysis method for reconstructing the arrival direction of TeV gamma rays using a single imaging atmospheric Cherenkov telescope

Abstract We present a method of atmospheric Cherenkov imaging which reconstructs the unique arrival direction of TeV gamma rays using a single telescope. The method is derived empirically and utilizes several features of gamma-ray-induced air showers which determine, to a precision of 0.12°, the arrival direction of photons on an event-by-event basis. Data from the Whipple Observatory's 10 m gamma-ray telescope are utilized to test selection methods based on source location. The results compare these selection methods with traditional techniques and three different camera fields of view. The method will be discussed in the context of a search for a gamma-ray signal from a point source located anywhere within the field of view and from regions of extended emission.
Simple, Efficient and Convenient Synthesis of Pyrroles and Pyrazoles Using Zeolites.

Abstract A convenient heterogeneous catalytic methodology for the synthesis of Pyrroles and Pyrazoles by an intermolecular reaction of γ or β-diketones with primary amines or hydrazine derivatives over zeolites are described.
The Economics of Resources or the Resources of Economics

It is easy to choose a subject for a distinguished lecture like this, before a large and critical audience with a wide range of interests. You need a topic that is absolutely contemporary, but somehow perennial. It should survey a broad field, without being superficial or vague. It should probably bear some relation to economic policy, but of course it must have some serious analytical foundations. It is nice if the topic has an important literature in the past of our subject – a literature which you can summarize brilliantly in about eleven minutes – but it better be something in which economists are interested today, and it should appropriately be a subject you have worked on yourself. The lecture should have some technical interest, because you can’t waffle for a whole hour to a room full of professionals, but it is hardly the occasion to use a blackboard.
Synthesis of 8-membered cyclic sulfamides: Novel HIV-1 protease inhibitors

Abstract One pot synthesis of pseudo C2 symmetric (2S,6S)-2,6-dihydroxy-1,7-diphenylhept-4-one in high enantiomeric purity has been developed and the intermediate was used for the synthesis of 8-membered cyclic sulfamides.
Hadronization in heavy-ion collisions: recombination or fragmentation?

We show that hadron production in relativistic heavy-ion collisions at transverse momenta larger than 2 GeV/c can be explained by the competition of two different hadronization mechanisms. Above 5 GeV/c hadron production can be described by fragmentation of partons that are created perturbatively. Below 5 GeV/c recombination of partons from the dense and hot fireball dominates. This can explain some of the surprising features of RHIC data such as the constant baryon-to-meson ratio of about one and the small nuclear suppression for baryons between 2 to 4 GeV/c.
Duration of labor induction in nulliparous women at term: how long is long enough?

We evaluated the relationship between duration of labor induction and successful vaginal delivery (VD) in nulliparous women at term. Nulliparous women with singleton pregnancies > or = 37 weeks who underwent labor induction at a single institution were studied. Exclusion criteria were nonvertex presentation, stillbirth, fetal chromosomal/structural abnormalities, spontaneous labor, and spontaneous rupture of membranes. VD rates and maternal/neonatal outcomes were evaluated and compared with respect to the duration from induction to delivery. Over the 1-year study period, 340 women met all criteria. Seventy-five percent achieved VD (n = 255), 40.6% of whom had rate of cervical dilation in active labor 40% had rate of cervical dilation in active labor < 1.0 cm/hour.
Quantum Mechanics with Applications to Quarkonium

Some methods of nonrelativistic quantum mechanics which are particularly useful for studying the variation of bound-state parameters with constituent mass and excitation energy are reviewed. These techniques rely upon elementary scaling arguments and on the semiclassical (WKB) approximation. They are of general interest, but are applied here to the study of bound systems of a heavy quark and antiquark. Properties of the interquark interaction are extracted from information about masses and loptonic widths of the ψ and Y families. It is shown how general methods can be applied to the determination of the electric charge of quarks and to the prediction of properties of new families.
Confidence Intervals for Half-Life Deviations From Purchasing Power Parity

Existing point estimates of half-life deviations from purchasing power parity (PPP), around 3–5 years, suggest that the speed of convergence is extremely slow. This article assesses the degree of uncertainty around these point estimates by using local-to-unity asymptotic theory to construct confidence intervals that are robust to high persistence in small samples. The empirical evidence suggests that the lower bound of the confidence interval is between four and eight quarters for most currencies, which is not inconsistent with traditional price-stickiness explanations. However, the upper bounds are infinity for all currencies, so we cannot provide conclusive evidence in favor of PPP either.
Testing MOND with VIRGOHI21

The ‘dark galaxy’ VIRGOHI21 seems to be composed of an unusually high proportion of dark matter and is situated in a strong external gravitational field. As such, it offers a rare test for theories of modified dynamics. If the system is bound, then its dynamics are inconsistent with those predicted by the MOND theory.
The Lost tribes of charmonium

To illustrate the campaign to extend our knowledge of the charmonium spectrum, the author focuses on a puzzling new state, X(3872) {yields} {pi}{sup +} {pi}{sup -} J/{psi}. Studying the influence of open-charm channels on charmonium properties leads us to propose a new charmonium spectroscopy: additional discrete charmonium levels that can be discovered as narrow resonances of charmed and anticharmed mesons. The author calls attention to open issues for theory and experiment.
Quarkonium at Finite Temperature

Abstract Lattice QCD studies on charmonium at finite temperature are presented After a discussion about problems for the Maximum Entropy Method applied to finite temperature lattice QCD, I show several results on charmonium spectral functions. The “wave function” of charmonium is also discussed to study the spatial correlation between quark and anti-quark in deconfinement phase.
Learning semantic string transformations from examples

We address the problem of performing semantic transformations on strings, which may represent a variety of data types (or their combination) such as a column in a relational table, time, date, currency, etc. Unlike syntactic transformations, which are based on regular expressions and which interpret a string as a sequence of characters, semantic transformations additionally require exploiting the semantics of the data type represented by the string, which may be encoded as a database of relational tables. Manually performing such transformations on a large collection of strings is error prone and cumbersome, while programmatic solutions are beyond the skill-set of end-users. We present a programming by example technology that allows end-users to automate such repetitive tasks.We describe an expressive transformation language for semantic manipulation that combines table lookup operations and syntactic manipulations. We then present a synthesis algorithm that can learn all transformations in the language that are consistent with the user-provided set of input-output examples. We have implemented this technology as an add-in for the Microsoft Excel Spreadsheet system and have evaluated it successfully over several benchmarks picked from various Excel help-forums.
Glassy dynamics of partially pinned fluids: An alternative mode-coupling approach

We propose a simple mode-coupling theory for glassy dynamics of partially pinned fluids. Our approach is different from the mode-coupling theory developed by Krakoviack (Phys. Rev. Lett., 94 (2005) 065703; Phys. Rev. E, 84 (2011) 050501(R)). In contrast to Krakoviack's theory, our approach predicts a random pinning glass transition scenario that is qualitatively the same as the scenario obtained using a mean-field analysis of the spherical p-spin model and a mean-field version of the random first-order transition theory. We use our approach to calculate quantities which are considered to be indicators of growing dynamic correlations and static point-to-set correlations. We find that the so-called static overlap is dominated by the simple, low pinning fraction contribution. Thus, at least for randomly pinned fluid systems, only a careful quantitative analysis of simulation results can reveal genuine, many-body point-to-set correlations.
Structured learning of two-level dynamic rankings

For ambiguous queries, conventional retrieval systems are bound by two conflicting goals. On the one hand, they should diversify and strive to present results for as many query intents as possible. On the other hand, they should provide depth for each intent by displaying more than a single result. Since both diversity and depth cannot be achieved simultaneously in the conventional static retrieval model, we propose a new dynamic ranking approach. In particular, our proposed two-level dynamic ranking model allows users to adapt the ranking through interaction, thus overcoming the constraints of presenting a one-size-fits-all static ranking. In this model, a user's interactions with the first-level ranking are used to infer this user's intent, so that second-level rankings can be inserted to provide more results relevant to this intent. Unlike previous dynamic ranking models, we provide an algorithm to efficiently compute dynamic rankings with provable approximation guarantees. We also propose the first principled algorithm for learning dynamic ranking functions from training data. In addition to the theoretical results, we provide empirical evidence demonstrating the gains in retrieval quality over conventional approaches.
Copper-Free Sonogashira Cross-Coupling for Functionalization of Alkyne-Encoded Proteins in Aqueous Medium and in Bacterial Cells

Bioorthogonal reactions suitable for functionalization of genetically or metabolically encoded alkynes, for example, copper-catalyzed azide-alkyne cycloaddition reaction ("click chemistry"), have provided chemical tools to study biomolecular dynamics and function in living systems. Despite its prominence in organic synthesis, copper-free Sonogashira cross-coupling reaction suitable for biological applications has not been reported. In this work, we report the discovery of a robust aminopyrimidine-palladium(II) complex for copper-free Sonogashira cross-coupling that enables selective functionalization of a homopropargylglycine (HPG)-encoded ubiquitin protein in aqueous medium. A wide range of aromatic groups including fluorophores and fluorinated aromatic compounds can be readily introduced into the HPG-containing ubiquitin under mild conditions with good to excellent yields. The suitability of this reaction for functionalization of HPG-encoded ubiquitin in Escherichia coli was also demonstrated. The high efficiency of this new catalytic system should greatly enhance the utility of Sonogashira cross-coupling in bioorthogonal chemistry.
Professor wheeler and the crack of doom: closed cosmologies in the 5-d Kaluza-Klein theory

We study the classical and the quantum structures of certain 5-d Kaluza-Klein cosmologies. These models were chosen because their 4-d restriction is a closed, radiation-dominated, homogeneous, isotropic cosmology in the usual sense. The extra (field) dimension is taken to be a circle. In these models the solution starts from a 5-d curvature singularity with infinite circumference for the circle and zero volume for the 3-space. It evolves in finite proper time to a solution with zero dimension for the extra field direction. In the 5-vacuum case this is not a curvature singularity, but is a singularity of the congruence describing the physics, and in particular, the solution cannot causally be extended to the future of this point. In the 5-vacuum case this event coincides with the maximum of expansion of the 5-space. In the 5-dust cases, this point is a real 5-d curvature singularity. By adjustment it can be made to occur before or after the maximum of 3-expansion. The solution stops at that instant, but the 4-cosmology revealsno pathology up to the crack of doom. The quantum behavior is identical in these respects to the classical one.
Studies on the synthesis of C-glycoside sulfones as potential glycosyl transferase inhibitors

Abstract β-C-Glycoside sulfoxides and sulfones were prepared by radical addition of thiol acetic acid to exocyclic glycals followed by deacetylation, S-alkylation, and selective oxidation. These compounds are representative examples of a new class of molecules designed to be glycosyl transferase inhibitors.
MEDIAC: an on-line media planning system

The problem of media planning in advertising is a natural one for the application of mathematical models and computers. A great deal of data are available on who reads (or sees or hears) what. There are considerable data on what kinds of people are prospects for which types of product. There are many different media options available. Many judgments must be made. It would seem that there should be some organized way of combining judgments and data into a model, setting an objective, and then optimizing it to produce a good media plan.
Mesostructured Non-Oxidic Solids with Adjustable Worm-hole Shaped Pores: M-Ge-Q (Q=S, Se) Frameworks Based on Tetrahedral [Ge4Q10]4– Clusters

The discovery of MCM-41 and its relatives has spawned a revolution in the design and synthesis of tailored mesostructured oxide-based materials. By comparison, non-oxidic solids such as sulfides or selenides are only very little exploredÐpartly because of difficulties in handling or obtaining relevant precursors (e.g., [SiS4] 4± units). Direct sulfur and selenium analogs of MCM-41 type materials would be the thioand selenoaluminosilicates. However, these systems are expected to be very unstable to hydrolysis. Therefore, one needs a working analog for the sulfides and selenides to mimic some of the characteristics of the [SiO4] 4± unit. A suitable such building unit with tetrahedral topology and similar charge is the adamantane thioanion [Ge4S10] 4± (or its selenium analog) (Scheme 1), which is made of four corner-linked [GeS4] 4± tetrahedra. We have already studied in detail their corresponding salts (RNMe3)4[Ge4Q10] (abbrev. as CnGeQ) with various surfactants. Reports on mesostructured chalcogenides have begun to appear, such as CdS and ZnS prepared through the incorporation of surfactants. Also, initial studies on mesostructured tin sulfides and a brief report on the synthesis of mesostructured thiogermanates resulting from the hydrothermal treatment of amorphous GeS2 and C16H33NMe3 Br, (CTA), are noteworthy. Various microstructured metal sulfides resembling those of zeolites have been forecast and important first steps have been made in recent years. The adsorption and sensing behavior of some structurally well-defined microporous lamellar tin sulfides (cation)2Sn3S7 have been explored. [15] Small guests such as NH3, H2S, and alcohols were found to interact with these materials. A recent exciting development toward producing well-defined mesostructured materials is the discovery of ASU-32, a novel indium sulfide that features pore diameters of ~14.5 .
50-Mb/s diffuse infrared free-space link using on-off keying with decision-feedback equalization

We report an experimental 50-Mb/s free-space infrared link for indoor wireless communication, which achieves low bit-error rates (BERs) in the presence of multipath distortion, shadowing, and ambient natural and artificial lighting. The eye-safe 806 nm transmitter, directed at the ceiling, emits an on-off-keyed signal having 475-mW average power. The receiver employs a 1-cm/sup 2/ Si p-i-n photodiode coupled to a high-index hemispherical concentrator, which is covered by an optical bandpass filter of 30-nm bandwidth. A decision-feedback equalizer mitigates the effect of multipath ISI. In the presence of bright skylight, the link achieves a range of 2.9 m at 10/sup -7/ BER. >
Contribution of fibrinolysis to the physical component summary of the SF-36 after acute submassive pulmonary embolism.

Acute pulmonary embolism (PE) can diminish patient quality of life (QoL). The objective was to test whether treatment with tenecteplase has an independent effect on a measurement that reflects QoL in patients with submassive PE. This was a secondary analysis of an 8-center, prospective randomized controlled trial, utilizing multivariate regression to control for predefined predictors of worsened QoL including: age, active malignancy, history of PE or deep venous thrombosis (DVT), recurrent PE or DVT, chronic obstructive pulmonary disease and heart failure. QoL was measured with the physical component summary (PCS) of the SF-36. Analysis included 76 patients (37 randomized to tenecteplase, 39 to placebo). Multivariate regression yielded an equation f(8, 67), P < 0.001, with R2 = 0.303. Obesity had the largest effect on PCS (β = −8.6, P < 0.001), with tenecteplase second (β = 4.73, P = 0.056). After controlling for all interactions, tenecteplase increased the PCS by +5.37 points (P = 0.027). In patients without any of the defined comorbidities, the coefficient on the tenecteplase variable was not significant (−0.835, P = 0.777). In patients with submassive PE, obesity had the greatest influence on QoL, followed by use of fibrinolysis. Fibrinolysis had a marginal independent effect on patient QoL after controlling for comorbidities, but was not significant in patients without comorbid conditions.
Measuring Political Sentiment on Twitter: Factor Optimal Design for Multinomial Inverse Regression

This article presents a short case study in text analysis: the scoring of Twitter posts for positive, negative, or neutral sentiment directed toward particular U.S. politicians. The study requires selection of a subsample of representative posts for sentiment scoring, a common and costly aspect of sentiment mining. As a general contribution, our application is preceded by a proposed algorithm for maximizing sampling efficiency. In particular, we outline and illustrate greedy selection of documents to build designs that are D-optimal in a topic-factor decomposition of the original text. The strategy is applied to our motivating dataset of political posts, and we outline a new technique for predicting both generic and subject-specific document sentiment through the use of variable interactions in multinomial inverse regression. Results are presented for analysis of 2.1 million Twitter posts collected around February 2012. Computer codes and data are provided as supplementary material online.
Mitigating Investor Risk-Seeking Behavior in a Down Real Estate Market

Using an extension of the prospect theory known as false reference points, this study examines the behavior of real estate investors after experiencing a loss. The results confirm our central hypothesis that when investors attempt to avoid the pain of regret by changing the lens through which they view losses, they become more likely to hold onto bad investments. This unwillingness to sell bad investments in the short run causes investors to be more likely to experience heightened levels of unavoidable regret in the long run. The results hold across demographic characteristics but are slightly more pronounced for men and international investors, specifically those from Asia.
Infection with Chlamydia trachomatis: Involvement of Multiple Anatomic Sites in Neonates

In a study of infection due to Chlamydia trachomatis in infants, chlamydiae were recovered not only from the conjunctiva and respiratory tract but also from the vagina and rectum. The timing of recovery suggested that the vagina and conjunctivae are exposed to chlamydiae at birth and that pneumonia and gastrointestinal infection occur later. Sampling of the rectum may be a useful procedure for the diagnosis of chlamydial disease in infants. Chlamydia trachomatis causes inclusion blennorrhea and pneumonia in infants who acquire the organism from their mothers during passage through the birth canal [1-3]. The use of tissue culture isolation methods has vastly improved our ability to diagnose chlamydial infections. The anatomic sites of infants that are usually sampled are the conjunctiva, nasopharynx, trachea, bronchi, and lung.
Electron parallel closures for arbitrary collisionality

Electron parallel closures for heat flow, viscosity, and friction force are expressed as kernel-weighted integrals of thermodynamic drives, the temperature gradient, relative electron-ion flow velocity, and flow-velocity gradient. Simple, fitted kernel functions are obtained for arbitrary collisionality from the 6400 moment solution and the asymptotic behavior in the collisionless limit. The fitted kernels circumvent having to solve higher order moment equations in order to close the electron fluid equations. For this reason, the electron parallel closures provide a useful and general tool for theoretical and computational models of astrophysical and laboratory plasmas.
PERSISTENT LAMINATIONS FROM SEIFERT SURFACES

We show how an incompressible Seifert surface F for a knot K in S3 can be used to create an essential lamination ℒF in the complement of each of an infinite class of knots associated to F. This lamination is persistent for these knots; it remains essential under all non-trivial Dehn fillings of the knot complement. This implies a very strong form of Property P for each of these knots.
An assessment of organizational practices in data processing environments

The results of an empirical study of 202 business data processing subjects from twelve computer centers in metropolitan Atlanta are reported. Perceptions of organizational practices were measured and then subjected to factor analysis and reliability criteria. Ten factors were used in the data analysis. Management Ability to Make Decisions and Select Personnel emerged as the most significant single factor. People oriented factors appeared to offer the greatest potential pay-offs. Implications for data processing management are discussed.
Technical risks and mitigation measures in combustion turbine project development

Project developers, insurers, financiers, and maintenance organizations have an interest in quantifying technical risks and evaluating risk mitigation alternatives for combustion turbine (CT) power plants. By identifying exposure to risk early in the project development process, optimal procurement decisions, and mitigation measures can be adopted for improved financial returns. This paper describes a methodology used to quantify all nonfuel O&M costs, including scheduled and unplanned maintenance, and business interruption costs due to unplanned outages. The paper offers examples that demonstrate the impact of technical risk on project profitability. An overview of activities required for addressing technical risk as part of the equipment selection and procurement process is provided, and areas of technical improvements for reducing life cycle costs are described.
Metal-organic frameworks as a tunable platform for designing functional molecular materials.

Metal–organic frameworks (MOFs), also known as coordination polymers, represent an interesting class of crystalline molecular materials that are synthesized by combining metal-connecting points and bridging ligands. The modular nature of and mild conditions for MOF synthesis have permitted the rational structural design of numerous MOFs and the incorporation of various functionalities via constituent building blocks. The resulting designer MOFs have shown promise for applications in a number of areas, including gas storage/separation, nonlinear optics/ferroelectricity, catalysis, energy conversion/storage, chemical sensing, biomedical imaging, and drug delivery. The structure–property relationships of MOFs can also be readily established by taking advantage of the knowledge of their detailed atomic structures, which enables fine-tuning of their functionalities for desired applications. Through the combination of molecular synthesis and crystal engineering, MOFs thus present an unprecedented opportunity fo...
New insights into the narrow-line Seyfert 1 phenomenon

Abstract I briefly review the X/UV absorber models and show that the observations of NLS1s are generally consistent with the models. The covering factor of absorbers in NLS1s is likely to be high and there is some evidence of super-solar metallicities. I argue that NLS1s may be active galaxies in the early stage of their evolution and as such, may be low luminosity, low redshift analogues of the high redshift quasars. NLS1s may reside in rejuvenated gas-rich galaxies. I also propose that the high Fe II emission in NLS1s may be a direct consequence of their large accretion rate and so a collisional ionization origin of Fe II is favored.
Socially aware computation and communication

By building machines that understand social signaling and social context, we can dramatically improve collective decision making and help keep remote users 'in the loop.' I will describe three systems that have a substantial understanding of social context, and use this understanding to improve human group performance. The first system is able to interpret social displays of interest and attraction, and uses this information to improve conferences and meetings. The second is able to infer friendship, acquaitance, and workgroup relationships, and uses this to help people build social capital. The third is able to examine human interactions and categorize participants attitudes (attentive, agreeable, determined, interested, etc), and uses this information to proactively promote group cohesion and to match participants on the basis of their compatiblity.
Tiltrotor Research Aircraft composite blade repairs - Lessons learned

The XV-15, N703NA Tiltrotor Research Aircraft located at the NASA Ames Research Center, Moffett Field, California, currently uses a set of composite rotor blades of complex shape known as the advanced technology blades (ATBs). The main structural element of the blades is a D-spar constructed of unidirectional, angled fiberglass/graphite, with the aft fairing portion of the blades constructed of a fiberglass cross-ply skin bonded to a Nomex honeycomb core. The blade tip is a removable laminate shell that fits over the outboard section of the spar structure, which contains a cavity to retain balance weights. Two types of tip shells are used for research. One is highly twisted (more than a conventional helicopter blade) and has a hollow core constructed of a thin Nomex-honeycomb-and-fiberglass-skin sandwich; the other is untwisted with a solid Nomex honeycomb core and a fiberglass cross-ply skin. During initial flight testing of the blades, a number of problems in the composite structure were encountered. These problems included debonding between the fiberglass skin and the honeycomb core, failure of the honeycomb core, failures in fiberglass splices, cracks in fiberglass blocks, misalignment of mated composite parts, and failures of retention of metal fasteners. Substantial time was spent in identifying and repairing these problems. Discussed here are the types of problems encountered, the inspection procedures used to identify each problem, the repairs performed on the damaged or flawed areas, the level of criticality of the problems, and the monitoring of repaired areas. It is hoped that this discussion will help designers, analysts, and experimenters in the future as the use of composites becomes more prevalent.
Multiple trains of same-color surface plasmon-polaritons guided by the planar interface of a metal and a sculptured nematic thin film. Part IV: Canonical problem

The canonical problem of the propagation of surface-plasmon-polariton (SPP) waves localized to the planar interface of a metal and a sculptured nematic thin film (SNTF) that is periodically nonhomogeneous along the direction normal to the interface was formulated. Solution of the dispersion equation obtained thereby confirmed the possibility of exciting multiple SPP waves of the same frequency or color. However, these SPP waves differ in phase speed, field structure, and the e-folding distance along the direction of propagation.
Tissue engineering of a human sized and shaped auricle using a mold.

Objectives: The creation of a tissue-engineered auricle was initially successful in an immunocompromised nude mouse model. Subsequently, an immunocompetent porcine model successfully generated a helical construct. We wished to evaluate the novel technique of using a mold to create a complete, anatomically refined auricle in a large animal model. Methods: Mixtures of autogenous chondrocytes and biodegradable polymers were used inside a perforated, auricle shaped hollow gold mold. Three biodegradable polymers (calcium alginate, pluronic F-127, and polyglycolic acid) were used to retain the seeded chondrocytes inside the mold. These molds, along with a control, were implanted subcutaneously in the abdominal area of 10 animals (pigs and sheep). The constructs were removed after 8 to 20 weeks and were assessed by gross morphology and histology. Results: All the gold implants were well tolerated by the animals. The implants using calcium alginate (n = 3) generated constructs of the exact shape and size of a normal human ear; the histology demonstrated mostly normal cartilage with some persistent alginate. The implants with pluronic F-127 (n = 3) resulted in cartilage with essentially normal histology, although leakage outside the molds and external cartilage generation was noted. Polyglycolic acid implants (n = 3) produced no useful cartilage because of an inflammatory reaction with fibrosis. The empty control mold (n = 1) demonstrated only a very small amount of fibrous tissue inside. Conclusion: A tissue-engineered human sized auricle of normal anatomic definition can be generated in an immunocompetent large-animal model using a mold technique. Although further refinements will be necessary, the technique appears promising for potential use in patients with microtia.
Golden Rules for Sustainable Resource Management

This paper presents a simple model of resource management that combines use of a non-renewable resource, such as oil, with eventual transition to a backstop substitute resource in infinite supply (e.g., solar energy). In the context of this model, we derive golden rules that govern efficiency in both the accumulation of capital and in the extraction of natural resources for use in production. These results supplement the Solow-Hartwick model of maximin consumption in helping to illuminate the notion of sustainable development.
Lefschetz extensions, tight closure and big Cohen-Macaulay algebras

We associate to every equicharacteristic zero Noetherian local ring R a faithfully flat ring extension, which is an ultraproduct of rings of various prime characteristics, in a weakly functorial way. Since such ultraproducts carry naturally a non-standard Frobenius, we can define a new tight closure operation on R by mimicking the positive characteristic functional definition of tight closure. This approach avoids the use of generalized Neron Desingularization and only relies on Rotthaus’ result on Artin Approximation in characteristic zero. Moreover, if R is equidimensional and universally catenary, then we can also associate to it in a canonical, weakly functorial way a balanced big Cohen-Macaulay algebra.
Color Gradients Detected in the HD 15115 Circumstellar Disk

We report HST NICMOS coronagraphic images of the HD 15115 circumstellar disk at 1.1 μm. We find a similar morphology to that seen in the visible and at H band—an edge-on disk that is asymmetric in surface brightness. Several aspects of the 1.1 μm data are different, highlighting the need for multiwavelength images of each circumstellar disk. We find a flattening to the western surface brightness profile at 1.1 μm interior to 2'' (90 AU) and a warp in the western half of the disk. We measure the surface brightness profiles of the two disk lobes and create a measure of the dust scattering efficiency between 0.55 and 1.65 μm at 1'', 2'', and 3''. At 2'' the western lobe has a neutral spectrum up to 1.1 μm and a strong absorption or blue spectrum >1.1 μm, while a blue trend is seen in the eastern lobe. At 1'' the disk has a red F 110W − H color in both lobes.
Catalytic Enantioselective Cyclization/Cross-Coupling with Alkyl Electrophiles

As part of our ongoing effort to expand the scope of cross-coupling reactions of alkyl electrophiles, we have pursued a strategy wherein the nucleophilic coupling partner includes a pendant olefin; after transmetalation by such a substrate, if β-migratory insertion proceeds faster than direct cross-coupling, an additional carbon–carbon bond and stereocenter can be formed. With the aid of a nickel/diamine catalyst (both components are commercially available), we have established the viability of this approach for the catalytic asymmetric synthesis of 2,3-dihydrobenzofurans and indanes. Furthermore, we have applied this new method to the construction of the dihydrobenzofuran core of fasiglifam, as well as to a cross-coupling with a racemic alkyl electrophile; in the latter process, the chiral catalyst controls two stereocenters, one that is newly generated in a β-migratory insertion and one that begins as a mixture of enantiomers.
Central limit theorem for nonlinear Hawkes processes

The Hawkes process is a self-exciting point process with clustering effect whose intensity depends on its entire past history. It has wide applications in neuroscience, finance, and many other fields. In this paper we obtain a functional central limit theorem for the nonlinear Hawkes process. Under the same assumptions, we also obtain a Strassen's invariance principle, i.e. a functional law of the iterated logarithm.
A Record Nine Different Phases (Four Cubic, Two Hexagonal, and One Lamellar Lyotropic Liquid Crystalline and Two Micellar Solutions) in a Ternary Isothermal System of an Amphiphilic Block Copolymer and Selective Solvents (Water and Oil)

We report on a ternary isothermal system consisting of a poly(ethylene oxide)/poly(propylene oxide) (PEO/PPO) amphiphilic block copolymer, “water”, and “oil” (where “water” and “oil” are selective solvents for the different blocks), which exhibits the richest structural polymorphism ever observed (in equilibrium) in mixtures containing amphiphiles (such as block copolymers, surfactants, or lipids). The microstructure resulting from the self-assembly of the PEO/PPO block copolymer can vary from normal (oil-in-water) micelles in solution, through all types of normal and reverse (water-in-oil) lyotropic liquid crystals (normal micellar cubic, normal hexagonal, normal bicontinuous cubic, lamellar, reverse bicontinuous cubic, reverse hexagonal, reverse micellar cubic), to reverse micelles, as the relative volume fraction of the apolar (“oil”-like) components increases over that of the polar (“water”-like) components. The structure in the liquid crystalline phases has been established with small-angle X-ray sca...
A search for low surface brightness structure around compact narrow emission line galaxies

As the most extreme members of the rapidly evolving faint blue galaxy population at intermediate redshift, the compact narrow emission line galaxies (CNELGs) are intrinsically luminous (� 22 PMBP � 18) with narrow emis- sion line widths (30 km s � 1 PP125 km s � 1 ). Their nature is heavily debated: they may be low-mass starbursting galaxies that will fade to present-day dwarf galaxies or bursts of star formation temporarily dominating the flux of more massive galaxies, possibly related to in situ bulge formation or the formation of cores of galaxies. We present deep, high-quality (� 0B6-0B8) images with CFHTof 27 CNELGs. One galaxy shows clear evidence for a tidal tail; theothers arenotunambiguouslyembeddedingalacticdisks.Approximately55%oftheCNELGshavesizes consis- tent with local dwarfs of small to intermediate sizes, while 45% have sizes consistent with large dwarfs or disk gal- axies. At least four CNELGs cannot harbor substantial underlying disk material; they are low-luminosity galaxies at the present epoch (MB > � 18). Conversely, 15 are not blue enough to fade to low-luminosity dwarfs (MB > � 15:2). The majority of the CNELGs are consistent with progenitors of intermediate-luminosity dwarfs and low-luminosity spiral galaxies with small disks. CNELGs are a heterogeneous progenitor population with significant fractions (up to44%)capableof fadingintotoday'sfaintdwarfs(MB > � 15:2),while15%-85%mayonlyexperienceanappar- ently extremely compact CNELG phase at intermediate redshift but remain more luminous galaxies at the present epoch. Subject headingg galaxies: evolution — galaxies: high-redshift
Where children sit in motor vehicles: A comparison of selected European and American cities

Objectives —To ascertain whether there are differences in child seating location between selected cities in the US and continental Europe, and if differences exist, to ascertain what factors predict them. Setting —Boston and New Orleans, which have no laws regarding child seating location, and Paris, Frankfurt, and Brussels, which for approximately 20 years have had laws requiring children under the ages of 10 or 12 to sit in the rear. Methods —Observations were made in the first quarter of 1997 at several locations in or near each city. The vehicle seating capacity, total number of occupants, the seating location of adults and children, and driver shoulder belt use were recorded for each vehicle with at least one child. The predictors of a vehicle having a child in the front were estimated using logistic regression. Results —Data on 5501 children riding in 3778 vehicles were collected. Adjusting for differences in vehicle seating capacity, occupant mix, and driver shoulder belt use, vehicles in the European cities are significantly less likely to have a child in the front seat than vehicles in the American cities. Conclusions —Cities with no history of laws prohibiting children from sitting in the front, vehicles with low seating capacity, vehicles with no adult (other than the driver) or many child passengers, and unbelted drivers were associated with a higher likelihood of children riding in the front seat. It is feasible for a society to insist, through custom and/or law, that children sit in the back seat.
Comment: Bayesian Checking of the Second Levels of Hierarchical Models

This article extends Bayarri and Berger’s (1999) proposal for model evaluation using “partial posterior” p values to the evaluation of second-stage model assumptions in hierarchical models. Applications focus on normal-normal hierarchical models, although the final example involves an application to a beta-binomial model in which the distribution of the test statistic is assumed to be approximately normal. The notion of using partial posterior p values is potentially appealing because it avoids what the authors refer to as “double use” of the data, that is, use of the data for both fitting model parameters and evaluating model fit. In classical terms, this phenomenon is synonymous to masking and is widely known to reduce the power of test statistics for diagnosing model inadequacy. In the present context, masking is avoided by defining the reference distribution of a test statistic t by the partial posterior distribution, defined as
Structural design principles for self-assembled coordination polygons and polyhedra

Strategies for the design of ligands that combine with metal ions to form high-symmetry coordination assemblies are reviewed. Evaluation of crystal structure evidence reveals that prior design approaches, based on the concept of complementary bonding vector angles, fail to predict the majority of known examples. After explaining the reasons for this failure, it is shown how an alternative approach, de novo structure-based design, provides a practical method that predicts a much wider range of component shapes encoded to direct the formation of such assemblies.