cssi/SciSciGPT-SciSciNet huggingface dataset:
Reconstructing the World's Museums

Virtual exploration tools for large indoor environments (e.g. museums) have so far been limited to either blueprint-style 2D maps that lack photo-realistic views of scenes, or ground-level image-to-image transitions, which are immersive but ill-suited for navigation. On the other hand, photorealistic aerial maps would be a useful navigational guide for large indoor environments, but it is impossible to directly acquire photographs covering a large indoor environment from aerial viewpoints. This paper presents a 3D reconstruction and visualization system for automatically producing clean and well-regularized texture-mapped 3D models for large indoor scenes, from ground-level photographs and 3D laser points. The key component is a new algorithm called "inverse constructive solid geometry (CSG)" for reconstructing a scene with a CSG representation consisting of volumetric primitives, which imposes powerful regularization constraints. We also propose several novel techniques to adjust the 3D model to make it suitable for rendering the 3D maps from aerial viewpoints. The visualization system enables users to easily browse a large-scale indoor environment from a bird's-eye view, locate specific room interiors, fly into a place of interest, view immersive ground-level panorama views, and zoom out again, all with seamless 3D transitions. We demonstrate our system on various museums, including the Metropolitan Museum of Art in New York City--one of the largest art galleries in the world.
Re-engineering: a breakthrough or little new?

Abstract This paper first provides various definitions of the term re-engineering. Next, it explains why companies undertake re-engineering and what factors represent major inputs to the process. An attempt is made to provide a sequence of steps that must be gone through for implementing any re-engineering project. In addition, the paper highlights those key risks and problems that cannot be avoided during its execution. In the end, the authors argue that re-engineering includes little new; rather, most of its constituents can be found in organizational improvement programs of the past. Even the success factors for re-engineering are not much different from those of earlier programs. The paper also provides a tabular analysis of 25 published re-engineering caselets in support of the thesis that re-engineering is not new, but can be any combination of action-items designed to improve the profitability and long-term survival of a company. Finally, a few conjectures about the future of re-engineering programs are outlined.
Study of the Delta (1232) Using Double Polarization Asymmetries

An extensive experimental program to measure the spin structure of the nucleus is underway in Hall B at Jefferson Lab using a polarized electron beam incident on a polarized target. Spin degrees of freedom offer the possibility to test, in an independent way, existing models of resonance electro-production. The present analysis selects the Delta{sup +} (1232) in the exclusive channel {rvec p}({rvec e}, e'p)pi{sup 0} from data of the EG1 run period, taken in the Fall of 1998, to extract single and double asymmetries in a Q{sup 2} range from 0.5 to 1.5 GeV{sup 2}/c{sup 2}. Results of the asymmetries are presented as a function of momentum transfer Q{sup 2}. A comparison with the Effective Lagrangian Model by R. Davidson and N. Mukhopadhyay, the unitary isobar model MAID, and the dynamic model by Sato and Lee was performed. The data were found to be generally in good agreement with the models and a x{sup 2} comparison preferred the Sato-Lee model, which is tailored for the Delta (1232) photo- and electro-production. The present results are the first measurement of asymmetries for the exclusive reaction {rvec p}({rvec e}, e'p)pi{sup 0} and will provide new constraints for the models.
Molecular mechanisms of drug addiction

Regulation of gene expression is one mechanism by which drugs of abuse can induce relatively long-lasting changes in the brain to cause a state of addiction. Here, we focus on two transcription factors, CREB (cAMP response element binding protein) and DeltaFosB, which contribute to drug-induced changes in gene expression. Both are activated in the nucleus accumbens, a major brain reward region, but mediate different aspects of the addicted state. CREB mediates a form of tolerance and dependence, which dampens an individual's sensitivity to subsequent drug exposure and contributes to a negative emotional state during early phases of withdrawal. In contrast, DeltaFosB mediates a state of relatively prolonged sensitization to drug exposure and may contribute to the increased drive and motivation for drug, which is a core symptom of addictive disorders. A major goal of current research is to identify the many target genes through which CREB and DeltaFosB mediate these behavioral states. In addition, future work needs to understand how CREB and DeltaFosB, acting in concert with numerous other drug-induced molecular changes in nucleus accumbens and many other brain regions, interact with one another to produce the complex behavioral phenotype that defines addiction.
An Infrared Excess Identified in Radio-loud Broad Absorption Line Quasars

If broad absorption line (BAL) quasars represent a high-covering-fraction evolutionary state (even if this is not the sole factor governing the presence of BALs), it is expected that they should show an excess of mid-infrared radiation compared to normal quasars. Some previous studies have suggested that this is not the case. We perform the first analysis of the IR properties of radio-loud BAL quasars, using IR data from WISE and optical (rest-frame ultraviolet) data from SDSS, and compare the BAL quasar sample with a well-matched sample of unabsorbed quasars. We find a statistically significant excess in the mid- to near-infrared luminosities of BAL quasars, particularly at rest-frame wavelengths of 1.5 and 4 μm. Our sample was previously used to show that BALs are observed along many lines of sight toward quasars, but with an overabundance of more edge-on sources, suggesting that orientation factors into the appearance of BALs. The evidence here—of a difference in IR luminosities between BAL quasars and unabsorbed quasars—can be ascribed to evolution. This suggests that a merging of the current BAL paradigms is needed to fully describe the class.
Catalytic intermolecular hydroacylation of C–C π-bonds in the absence of chelation assistance

Intermolecular rhodium catalyzed hydroacylation in the absence of chelation assistance remains a largely unmet challenge due to competing decarbonylation of the acylrhodium intermediates to form catalytically inactive carbonyl complexes. Here, catalytic systems for intermolecular hydroacylation in the absence of chelation assistance are reviewed, with an emphasis on recently described processes that operate through mechanistic pathways beyond aldehyde C–H oxidative addition.
Observed Attenuation and Q Values of Seismic Surface Waves in the Upper Mantle

Attenuation coefficients and Q values of Love and Rayleigh waves in the period range 50–330 sec have been derived from the amplitude spectrums of these waves. Data were obtained from surface wave signals of twelve earthquakes recorded at Pasadena and some other USCGS standardized stations on a variety of seismographs. The resulting absorption parameters, as determined from all seismic events, show a mean scatter of about 10%. Nevertheless, data from each event indicate a systematic higher attenuation (lower Q) for Love waves than for Rayleigh waves. The attenuation coefficients for both waves tend to increase almost linearly with frequency, and the corresponding Q functions are slowly varying in the period range 50–150 sec, with mean values QL = 105 and QR = 145. In contradistinction to the phase velocities, there is no evidence yet for a persistent difference in attenuation of mantle surface waves under oceans and continents.
Optical ray tracing for crossed beam photothermal deflection spectroscopy

A geometrical algorithm for optical ray tracing is used to trace the trajectories of probe laser beam rays in pulsed photothermal deflection spectroscopy (PDS) of a static gas. Rays are traced as a function of various parameters such as time, absorbed pump beam energy, radius, and pulse duration. The exit angle is also computed and compared with the deflection angle calculated analytically with very good agreement for a pump pulse duration shorter than the thermal diffusion time. For a long pump pulse duration, the analytical expression is inaccurate due to the neglect of thermal diffusion during the pump pulse. Probe beam ray crossing is examined and found to be unimportant for most common PDS situations. The saturation of the PD signal is found for high absorbed pump pulse energy; this is due to excessive heating of the absorber. Finally, the maximum probe beam deflection occurs when the deflection is measured at a time corresponding to the end of the pump pulse duration.
A d’Alembert Formula for Hopf Hypersurfaces

A Hopf hypersurface in complex hyperbolic space \({\mathbb{C}{\rm H}^n}\) is one for which the complex structure applied to the normal vector is a principal direction at each point. In this paper, Hopf hypersurfaces for which the corresponding principal curvature is small (relative to ambient curvature) are studied by means of a generalized Gauss map into a product of spheres, and it is shown that the hypersurface may be recovered from the image of this map, via an explicit parametrization.
Nanomaterials for targeted detection and photothermal killing of bacteria

Despite the modern treatment processes, contamination of food, water and medical equipment by pathogenic bacteria is very common in this world. Since the last two decades, one of the most important and complex problems our society has been facing is that several human pathogens became resistant to most of the clinically approved antibiotics. Recent advancement in nanoscience and nanotechnology has expanded our ability to design and construct nanomaterials with targeting, therapeutic, and diagnostic functions. These multifunctional materials have attracted our attention to be used as the promising tool for selective bacteria sensing and therapy without the current drugs. This tutorial review provides the basic concepts and critical properties of the different nanostructures that are useful for the pathogen detection and photothermal applications. In addition, bio-conjugated nanomaterial based strategies have been discussed with the aim to provide readers an overview of exciting opportunities and challenges in this field.
Search for t→ch at e+e− linear colliders

Abstract We study the rare top-quark decay t→ch, where h is a generic Higgs boson, at a linear collider. If kinematically accessible, all models contain this decay at some level due to quark flavor mixing. Some models, such as Model III of the two-Higgs doublet model, have a tree-level top–charm–Higgs coupling, and the branching ratio is close to 0.5%. Others, such as the MSSM, have a coupling induced at one-loop, and can have a branching ratio in the range of 10−5–5×10−4. We find that a linear collider of s =500 GeV and a luminosity of 500 fb−1 will begin to be sensitive to this range of the coupling.
Aeroelasticity Research for Turbomachine Applications

The continuing demand for increased performance in turbine engine turbomachinery has aggravated dynamic problems in the various components, particularly the blading. These problems are generally classified into the categories of either flutter or forced response. Historically, the complexity of the flowfield necessitated the development of empirical flutter and forced-response design techniques. However, such empirical correlations have proven to be inadequate when extrapolated beyond past experience levels. Hence, current research effort, coordinated between industry, government, and universities, is directed toward the development of phenomcnologically founded approaches to these problems. Presented herein is an overview of this ajtack on aerodynamical!}' induced vibrations in turbomachines.
High Resolution Positron Emission Tomography Using Small Bismuth Germanate Crystals and Individual Photosensors

We describe and compare six detector approaches for coupling small bismuth germanate crystals to individual photosensors. 1) Partial coupling of individual crystals to small cylindrical phototubes. 2) Full coupling of individual crystals to small cylindrical phototubes via shaped lightpipes. 3) Coupling of cylindrical phototubes to individual crystals using three sides of the crystals. 4) Full coupling of individual crystals to small rectangular photomultiplier tubes. 5) Full coupling of groups of crystals to multipleanode phototubes. 6) Full coupling of groups of crystals to larger rectangular phototubes with either sense wires, solid state photosensors, or UV sensitive wire chambers for crystal identification. From experimental measurements and Monte Carlo computer simulations we conclude that approaches 5 and 6 are superior in pulse height and timing resolution and are also the best way to read out crystals narrower than 3 mm.
Helicobacter pylori seropositivity and risk of lung cancer.

Lung cancer is the leading cause of cancer mortality worldwide. Helicobacter pylori (H. pylori) is a risk factor for distal stomach cancer, and a few small studies have suggested that H. pylori may be a potential risk factor for lung cancer. To test this hypothesis, we conducted a study of 350 lung adenocarcinoma cases, 350 squamous cell carcinoma cases, and 700 controls nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) cohort of male Finnish smokers. Controls were one-to-one matched by age and date of baseline serum draw. Using enzyme-linked immunosorbent assays to detect immunoglobulin G antibodies against H. pylori whole-cell and cytotoxin-associated gene (CagA) antigens, we calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for associations between H. pylori seropositivity and lung cancer risk using conditional logistic regression. H. pylori seropositivity was detected in 79.7% of cases and 78.5% of controls. After adjusting for pack-years and cigarettes smoked per day, H. pylori seropositivity was not associated with either adenocarcinoma (OR: 1.1, 95% CI: 0.75–1.6) or squamous cell carcinoma (OR: 1.1, 95% CI: 0.77–1.7). Results were similar for CagA-negative and CagA-positive H. pylori seropositivity. Despite earlier small studies suggesting that H. pylori may contribute to lung carcinogenesis, H. pylori seropositivity does not appear to be associated with lung cancer.
Inflight vertical antenna patterns for SIR-C from Amazon rain-forest observations☆

The full pattern for a large antenna is usually not well known because of the difficulty in measuring it on a range. For spaceborne synthetic aperture radar (SAR), the antenna may also be subjected to different gravitational stresses and temperature gradients that might deform its structure, so it is very likely that its pattern will be different from that on the ground. Moreover loss of elements on a distributed array can distort its pattern. In these cases, one can extract the relative vertical antenna pattern from the SAR images of target areas that are uniform on average. In this report, images taken from the Amazon rain-forest region are analyzed to yield an estimate of the inflight relative-gain vertical antenna pattern for the SIR-C. The method is the same as that used with SIR-B (Moore and Hemmat, 1988), with X-SAR (Fang and Moore, 1995), and for scatterometer antennas on Seasat. Here we give the SIR-C vertical (elevation) antenna patterns for different incident angles and beam spoiling modes over a range of 6 dB for SIR-C. Because only a few of the antenna modes were used over the Amazon, these patterns are only representative.
An Electrochemical Route for Making Porous Nickel Oxide Electrochemical Capacitors

Porous nickel oxide films were prepared by electrochemically precipitating nickel hydroxide and heating the hydroxide in air at 300 C. The resulting nickel oxide films behave as an electrochemical capacitor with a specific capacitance of 59 F/g electrode material. These nickel oxide films maintain high utilization at high rates of discharge (i.e., high power density) and have excellent cycle life. Porous cobalt oxide films were also synthesized. Although the specific capacitances of these films are approximately one-fifth that of the nickel oxide films, the results demonstrate the versatility of fabricating a wide range of porous metal oxide films using this electrochemical route for use in capacitor applications. Electrochemical capacitors have generated wide interest in recent years for use in high power applications (e.g., in a hybrid electric vehicle, where they are expected to work in conjunction with a conventional battery).
Numerical Model of a Tandem Reciprocating Hydraulic Rod Seal

A numerical model of a tandem reciprocating hydraulic rod seal, consisting of two elastomeric U cup seals, has been constructed. It is applicable to cases in which the stroke length is significantly larger than the seal width. The model consists of coupled steady state fluid mechanics, deformation mechanics, and contact mechanics analyses, with an iterative computational procedure. The behaviors of the two seals are coupled through the pressure/density in the interseal region and through flow continuity. Results for a typical tandem seal are compared to those of a single seal and a double lip seal.
Checking the Center: Popular Referenda in Japan

Local govemrnments of many countries have adopted popular referendum and allow their citizens to directly vote on specific laws enacted by the legislature. In Japan, however, popular referenda are heavily restricted and assume the form of indirect referenda because even when a sufficient number of signatures are filed, a proposal is first sent to the legislature, which may approve or reject the proposed measures. Moreover, in Japan, referenda are used merely as advisory tools, and legislatures are not bound by the result of the vote. Such stringent legislative control seems to render popular referenda ineffectual and defeats the purpose of direct legislation. Despite various restrictions, however, the number of both
Reduction of aldehydes using trialkylboranes in ionic liquids

Non-aqueous ionic liquids, molten salts, have been found to enhance organoboron mediated reductions of aldehydes.
Muscarinic receptors: What we know

An understanding of muscarinic receptors is tantamount to an understanding of overactive bladder and detrusor over-activity. The M3 muscarinic receptor subtype is responsible for detrusor smooth muscle contraction, and it exerts an exocrine function in the salivary glands. Alterations in the receptor’s response to acetylcholine as a result of injury may lead to hypersensitivity and overactivity. Muscarinic receptor immunoreactivity and myofibroblast activity have been identified in the urothelium. Additionally, activation of muscarinic receptors in the urothelium may modulate afferent sensory function. Newer research implicates the M1 receptor as responsible for significant cognitive adverse effects. Recent drug development has focused on greater selectivity for the M3 receptor and avoidance of central muscarinic receptors. Growing knowledge of the nuances of receptor-ligand behavior and interaction between muscarinic receptor subtypes may provide novel targets for future drug development, improve efficacy, and reduce bothersome side effects.
The Stellar Population of the Chamaeleon I Star-forming Region*

I present a new census of the stellar population in the Chamaeleon I star-forming region. Using optical and near-IR photometry and follow-up spectroscopy, I have discovered 50 new members of Chamaeleon I, expanding the census of known members to 226 objects. Fourteen of these new members have spectral types later than M6, which doubles the number of known members that are likely to be substellar. I have estimated extinctions, luminosities, and effective temperatures for the known members, used these data to construct an H-R diagram for the cluster, and inferred individual masses and ages with the theoretical evolutionary models of Baraffe and Chabrier. The distribution of isochronal ages indicates that star formation began 3-4 and 5-6 Myr ago in the southern and northern subclusters, respectively, and has continued to the present time at a declining rate. The IMF in Chamaeleon I reaches a maximum at a mass of 0.1-0.15 M☉ and thus closely resembles the IMFs in IC 348 and the Orion Nebula Cluster. In logarithmic units where the Salpeter slope is 1.35, the IMF is roughly flat in the substellar regime and shows no indication of reaching a minimum down to a completeness limit of 0.01 M☉. The low-mass stars are more widely distributed than members at other masses in the northern subcluster, but this is not the case in the southern subcluster. Meanwhile, the brown dwarfs have the same spatial distribution as the stars out to a radius of 3° (8.5 pc) from the center of Chamaeleon I.
Enhancement of cation transport in synthetic hydraphile channels having covalently-linked headgroups

A novel, pentamacrocyclic host molecule has been prepared in which four symmetry-equivalent diazacrown ethers lead to a dramatic enhancement in Na+ transport, across a phospholipid bilayer, relative to open-chained analogs lacking the fourth crown.
Quasar jets and their fields

Observations of jets from quasars and other types of accreting black holes are briefly summarized. The importance of beaming and gamma–ray observations for understanding the origin of these jets is emphasized. It is argued that both the power source and the collimation are likely to be magnetic in origin, although the details remain controversial. Ultrarelativistic jets may be formed by the spinning hole and collimated by a hydromagnetic disc wind. Progress in understanding jets has been handicapped by our inadequate knowledge of how the magnetic field really behaves under cosmic conditions. Fortunately, significant insights are coming from solar observations, numerical simulations and laboratory plasma experiments. Some possible evolutionary ramifications are briefly discussed and it is suggested that it is the mass of the black hole relative to that of the galaxy which determines the eventual galaxy morphology.
Reading the Satanic Verses

(1990). Reading the Satanic Verses. Third Text: Vol. 4, ‘Beyond the Rushdie Affair’, pp. 41-60.
Hydrodynamical Studies of Wind Accretion onto Compact Objects: Two-dimensional Calculations

We present the results of hydrodynamical simulations of nonaxisymmetric gas flow past a gravitating compact object in two dimensions. Calculations were performed with uniform flow as well as with transverse velocity and density gradients. We find that the flow is highly nonsteady, exhibiting the "flip-flop" behavior seen in previous studies, in which accretion disks form with alternating directions of rotation. We investigate the periodicity of the flip-flop behavior and study the effects of spatial resolution on the results. We find that the flip-flop motion creates accretion torques that, in some cases, may be large enough to explain the erratic spin behavior observed in Be-type X-ray pulsars.
Spitzer Planet Limits Around the Pulsating White Dwarf GD66

We present infrared observations in search of a planet around the white dwarf, GD66. Time-series photometry of GD66 shows a variation in the arrival time of stellar pulsations consistent with the presence of a planet with mass ≥2.4 MJ. Any such planet is too close to the star to be resolved, but the planet's light can be directly detected as an excess flux at 4.5 μm. We observed GD66 with the two shorter wavelength channels of the Infrared Array Camera on Spitzer but did not find strong evidence of a companion, placing an upper limit of 5-7 MJ on the mass of the companion, assuming an age of 1.2-1.7 Gyr.
Models for Spatially Dependent Missing Data

Most hedonic pricing studies using transaction data employ only sold properties. Since the properties sold during any year or even decade represent only a fraction of all properties, this approach ignores the potentially valuable information content of unsold properties which have known characteristics. In fact, explanatory variable information on house characteristics for all properties, sold and unsold, are often available from assessors. We set forth an estimation approach that predicts missing values of the dependent variable when the sample data exhibit spatial dependence. Employing information on the housing characteristics of both sold and unsold properties can improve prediction, increase estimation efficiency for the missing-at-random case, and reduce self-selection bias in the non-missing-at-random case. We demonstrate these advantages with a Monte Carlo experiment as well as with actual housing data.
New coordinates for de Sitter space and de Sitter radiation

We introduce a simple coordinate system covering half of de Sitter space. The new coordinates have several attractive properties: the time direction is a Killing vector, the metric is smooth at the horizon, and constant-time slices are just flat Euclidean space. We demonstrate the usefulness of the coordinates by calculating the rate at which particles tunnel across the horizon. When self-gravitation is taken into account, the resulting tunneling rate is only approximately thermal. The effective temperature decreases through the emission of radiation.
Total synthesis of (.+-.)-poitediol and (.+-.)4-epipoitediol

Synthese a partir du methyl-3 oxo-2 cyclopentane carboxylate de methyl via une bicyclo [3.2.0] heptanone-6
Reductive cleavage of glycosides with borane complexes in the presence of boron trifluoride etherate

Abstract Mixtures consisting of five equivalents each of borane · methyl sulfide and boron trifluoride etherate per equivalent of acetal or five equivalents of various amine-borane complexes and 10 equivalents of boron trifluoride etherate readily accomplished reductive cleavage of the glycosidic linkages of several per- O -methylated monosaccharides and polysaccharides. In all cases, the expected products were obtained in the expected molar proportions and no artifactual products were observed. Reductive-cleavage analysis using these reagents is particularly convenient because the reagents themselves are easy to handle and because subsequent acetylation of the products is accomplished in situ.
Immediate vs. Salvage resection after local treatment for early rectal cancer

PURPOSE: There is an increasing awareness of local procedures to treat early stage rectal cancer. Abdominoperineal resection (APR) or low anterior resection (LAR) has been recommended if adverse pathologic findings are encountered in the local excision specimen. No data compare the impact on survival of “immediate” resection for adverse featuresvs. “salvage” resection for clinical recurrence. METHODS: We reviewed retrospectively 155 patients who underwent initial curative treatment of invasive rectal cancer by excision (91), snare-cautery (44), and fulguration (20). RESULTS: Twenty-one patients underwent APR/LAR immediately after initial local treatment, whereas another 21 patients underwent salvage APR/LAR for local recurrence. The disease-free survival after APR/LAR was 94.1 percent for the immediate group and 55.5 percent for the delayed group (P<0.05). CONCLUSION: This decreased survival observed after delayed resection supports the recommendation for immediate APR/LAR when adverse pathologic features are present in the excision specimen.
Niobium−Arsenic Zintl Phases: A6NbAs5 (A = K, Rb, Cs), K6NbTlAs4, and K8NbPbAs5 with Edge-Bridged Niobium-Centered Tetrahedra of Arsenic, [NbAs4M]n- Where M = As, Tl, Pb

The five title compounds were prepared by direct reactions of the corresponding elements at high temperature. Their structures contain isolated anions of tetrahedral NbAs4 where one of the edges of the tetrahedron is bridged by a third atom. The bridging atom is arsenic in A6NbAs5 (monoclinic, P21/c, Z = 8; with a = 25.774(3) A, b = 9.335(1) A, c = 13.012(1) A, β = 101.05(1)° for A = K; a = 27.629(1) A, b = 9.925(1) A, c = 14.111(1) A, β = 101.63(1)° for A = Rb; and a = 27.405(1) A, b = 9.9447(6) A, c = 13.9964(8) A, β = 101.210(1)° for A = Cs), thallium in K6NbTlAs4 (orthorhombic, Pnma, Z = 4, a = 18.786(1) A, b = 10.4442(4) A, c = 7.715(1) A), and lead in K8NbPbAs5 (monoclinic, C2/c, Z = 8, a = 31.597(9) A, b = 9.353(1) A, c = 13.427(2) A, β = 95.25(1)°). The lead atom in the latter is bonded to a third arsenic atom as well. Magnetic measurements showed diamagnetic behavior, and therefore, the compounds are electronically balanced, closed-shell type compounds and can be described as transition-metal Zin...
Jacobi sums, fermat jacobians, and ranks of abelian varieties over towers of function fields

Our goal in this note is to give a number of examples of abelian varieties over function fields k(t) which have bounded ranks in towers of extensions such as k(t^{1/d}) for varying d. Along the way we prove some new results on Fermat curves which may be of independent interest.
Dynamical habitability of known extrasolar planetary systems

Habitability is usually defined as the requirement for a terrestrial planet's atmosphere to sustain liquid water. This definition can be complemented by the dynamical requirement that other planets in the system do not gravitationally perturb terrestrial planets outside of their habitable zone, the orbital region allowing the existence of liquid water. We quantify the dynamical habitability of 85 known extrasolar planetary systems via simulations of their orbital dynamics in the presence of potentially habitable terrestrial planets. When requiring that habitable planets remain strictly within their habitable zone at all times, the perturbing influence of giant planets extends beyond the traditional Hill sphere for close encounters: terrestrial planet excursions outside of the habitable zone are also caused by secular eccentricity variations and, in some cases, strong mean-motion resonances. Our results indicate that more than half the known extrasolar planetary systems (mostly those with distant, eccentric giant planets) are unlikely to harbor habitable terrestrial planets. About one-fourth of the systems (mostly those with close-in giant planets), including one-third of the potential targets for the Terrestrial Planet Finder, appear as dynamically habitable as our own solar system. The influence of yet undetected giant planets in these systems could compromise their dynamical habitability. Some habitable terrestrial planets in our simulations have substantial eccentricities (e > 0.1), which may lead to large seasonal climate variations and thus affect their habitability.
Correlating Structure and Function of Metal Nanoparticles for Catalysis

article i nfo Available online 2 April 2015 This paper summarizes several studies correlating the structure and function of nanoparticle catalysts. Three types of alloy nanoparticles are considered, random alloy, core@shell and alloy-core@shell structures. In the first two cases, the focus is to build theoretical models to understand previous experimental results. In the latter case, calculations play a greater role in leading the development of nanoparticle catalysts. We demonstrate that iterationbetweentheoryandexperimentcanfacilitateanunderstandingofnanoparticlecatalystsandreducethe time and effort involved in the design of new catalysts.
A Review of Metalorganic Chemical Vapor Deposition of High-Temperature Superconducting Thin Films

A status report is given on the metalorganic chemical vapor deposition (MOCVD) of high-temperature superconducting thin films. The advantages of MOCVD processing manifest themselves in the quality of the films produced, and in the economy of the process. Metalorganic precursor requirements, deposition parameters and film properties are discussed. Also difficulties have been identified in making MOCVD a manufacturing technology. To solve these problems, future research directions are proposed.
Anomaly inflow at singularities

Abstract Many noncompact Type I orbifolds satisfy tadpole constraints yet are anomalous. We present a generalization of the anomaly inflow mechanism for some of these cases in six and four dimensions.
ESTIMATION OF BINARY CHOICE MODELS WITH LINEAR INDEX AND DUMMY ENDOGENOUS VARIABLES

This paper presents computationally simple estimators for the index coe‐cients in a binary choice model with a binary endogenous regressor without relying on distributional assumptions or on large support conditions and yields root-n consistent and asymptotically normal estimators. We develop a multi-step method for estimating the parameters in a triangular, linear index, threshold-crossing model with two equations. In outlining this new estimation method two contributions are made. The flrst one is proposing a a novel "matching" estimator for the coe‐cient on the binary endogenous variable in the outcome equation. Second, in order to establish the asymptotic properties of the proposed estimators for the coe‐cients of the exogenous regressors in the outcome equation, the results of Powell, Stock and Stoker (1989) are extended to cover the case where the average derivative estimation requires a flrst step semi-parametric procedure.
Approximate null distribution of the largest root in multivariate analysis

The greatest root distribution occurs everywhere in classical multivariate analysis, but even under the null hypothesis the exact distribution has required extensive tables or special purpose software. We describe a simple approximation, based on the Tracy-Widom distribution, that in many cases can be used instead of tables or software, at least for initial screening. The quality of approximation is studied, and its use illustrated in a variety of setttings.
Efficacy of second generation antidepressants in late-life depression: a meta-analysis of the evidence.

Objective Second-generation antidepressants are commonly used to treat major depression in late-life. This systematic review and meta-analysis was undertaken to assess the evidence for efficacy of second-generation antidepressants in late-life major depression. Methods The Cochrane Library (2006 [3]), MEDLINE (1966 to August 2006), and meeting presentations were searched for trials of second-generation antidepressants (nontricyclics) marketed in the United States. Published and unpublished placebo-controlled randomized clinical trials in outpatients 60 years and older, with nonpsychotic, unipolar major depression were selected. Clinical characteristics and outcomes were extracted. Outcomes were expressed as odds ratios (OR), risk differences, and weighted mean differences. Results Ten unique trials (four unpublished) with 13 contrasts met selection criteria. Trials were 6–12 weeks duration, and included 2,377 patients who received active drug and 1,788 received placebo. The ORs by meta-analysis for response and remission were 1.40 (95% confidence interval [CI] 1.24–1.57, z = 5.45, N = 13, p Conclusions Antidepressants are more effective than placebo in elderly depressed subjects although effects are modest and vary. Identification of the characteristics of responders and nonresponders will be crucial to improving treatment outcomes.
New Opportunities from 4D Seismic and Lithology Prediction at Ringhorne Field, Norwegian North Sea

Time-lapse (4D) seismic data from the Ringhorne field in the North Sea are used to monitor water movement in both Paleocene and Jurassic age reservoir sands, improve existing geologic and simulation models, and enable more cost-effective field operations. The structural complexity of the reservoirs, their proximity to the high-impedance Cretaceous chalk, and a relatively small 4D response required a significant effort in seismic acquisition and processing which resulted in a highly repeatable survey. In addition to the 4D interpretation, Vp/Vs derived from simultaneous elastic inversion is diagnostic of sand and provides additional constraints on Ringhorne subsurface models. Connected volumes based on Vp/Vs correlate to areas of water sweep seen in the 4D data and reduce uncertainty in 4D interpretation. Relative P-wave impedance changes calculated from 4D inversion are consistent with pre-survey predictions. The 4D seismic and inversion results help explain water breakthrough timing, improve our understanding of field production history, and were critical inputs to an updated geologic model used for reservoir simulation. The data have resulted in an increase in the reserves base and the identification of additional infill well opportunities.
Global well-posedness for the critical 2D dissipative quasi-geostrophic equation

We give an elementary proof of the global well-posedness for the critical 2D dissipative quasi-geostrophic equation. The argument is based on a non-local maximum principle involving appropriate moduli of continuity.
DIBAL-mediated reductive transformation of trans-dimethyl tartrate acetonide into ε-hydroxy α,β-unsaturated ester and its derivatives.

Stepwise, selective DIBAL reduction of the acetonide diester derived from tartaric acid followed by the Horner– Emmons reaction effectively provided desymmetrized hydroxy mono-olefination products in a one-pot operation.
The Spitzer Space Telescope First-Look Survey: Neutral Hydrogen Emission

The Spitzer Space Telescope (formerly SIRTF) extragalactic First Look Survey covered about 5 deg2 centered on (J2000.0) ? = 17h18m, ? = 59?30' in order to characterize the infrared sky with high sensitivity. We used the 100 m Green Bank Telescope to image the 21 cm Galactic H I emission over a 3? ? 3? square, covering this position with an effective angular resolution of 98 and a velocity resolution of 0.62 km s-1. In the central square degree of the image the average column density is N = 2.5 ? 1020 cm-2 with an rms fluctuation of 0.3 ? 1020 cm-2. The Galactic H I in this region has a very interesting structure. There is a high-velocity cloud, several intermediate-velocity clouds (one of which is probably part of the Draco Nebula), and narrow-line low-velocity filaments. The H I emission shows a strong and detailed correlation with dust. Except for the high-velocity cloud, all features in the NH I map have counterparts in an E(B - V) map derived from infrared data. Relatively high E(B - V)/NH I ratios in some directions suggest the presence of molecular gas. The best diagnostic of such regions is the peak H I line brightness temperature, not the total NH I: directions where Tb > 12 K have E(B - V)/NH I significantly above the average value. The data corrected for stray radiation have been released via the World Wide Web.
An algorithmic version of the blow-up lemma

Recently we developed a new method in graph theory based on the regularity lemma. The method is applied to find certain spanning subgraphs in dense graphs. The other main general tool of the method, besides the regularity lemma, is the so-called blow-up lemma (Komlos, Sarkozy, and Szemeredi [Combinatorica,17, 109–123 (1997)]. This lemma helps to find bounded degree spanning subgraphs in e-regular graphs. Our original proof of the lemma is not algorithmic, it applies probabilistic methods. In this paper we provide an algorithmic version of the blow-up lemma. The desired subgraph, for an n-vertex graph, can be found in time O(nM(n)), where M(n)=O(n2.376) is the time needed to multiply two n by n matrices with 0, 1 entires over the integers. We show that the algorithm can be parallelized and implemented in NC5. © 1998 John Wiley & Sons, Inc. Random Struct. Alg., 12, 297–312, 1998
Three Modes of Metal-Enriched Star Formation in the Early Universe

Simulations of the formation of Population III (Pop III) stars suggest that they were much more massive than the Pop II and Pop I stars observed today. This is due to the collapse dynamics of metal-free gas, which is regulated by the radiative cooling of molecular hydrogen. We study how the collapse of gas clouds is altered by the addition of metals to the star-forming environment by performing a series of simulations of pre-enriched star formation at various metallicities. To make a clean comparison with metal-free star formation, we use initial conditions identical to a Pop III star formation simulation, with low ionization and no external radiation other than the cosmic microwave background (CMB). For metallicities below the critical metallicity, Z cr, collapse proceeds similar to the metal-free case, and only massive objects form. For metallicities well above Z cr, efficient cooling rapidly lowers the gas temperature to the temperature of the CMB. The gas is unable to radiatively cool below the CMB temperature, and becomes thermally stable. For high metallicities, Z 10?2.5 Z ?, this occurs early in the evolution of the gas cloud, when the density is still relatively low. The resulting cloud cores show little or no fragmentation, and would most likely form massive stars. If the metallicity is not vastly above Z cr, the cloud cools efficiently but does not reach the CMB temperature, and fragmentation into multiple objects occurs. We conclude that there were three distinct modes of star formation at high redshift (z 4): a primordial mode, producing massive stars (10s to 100s of M ?) at very low metallicities (Z 10?3.75 Z ?); a CMB-regulated mode, producing moderate mass (10s of M ?) stars at high metallicities (Z 10?2.5 Z ? at redshift z~ 15-20); and a low-mass (a few M ?) mode existing between these two metallicities. As the universe ages and the CMB temperature decreases, the range of the low-mass mode extends to higher metallicities, eventually becoming the only mode of star formation.
Synthesis of the fused bicyclic lactam-lactone terminus of neooxazolomycin by a novel dianion cyclocondensation

Abstract Reaction of the dianion (5) derived from an acylaminomalonic ester with S-(-)-MOM lactate (6) yields β-hydroxylactams 7 and 8 in a 2:1 ratio. Deprotection and lactonization of 7, followed by saponification and 2 step carboxyl reduction efficiently produces the fused bicyclic lactam-lactone 12, a chiral model of the antitumor antibiotic neooxazolomycm 1.
Metabolic effects on recombinant interferon-γ glycosylation in continuous culture of Chinese hamster ovary cells

Asparagine linked (N-linked) glycosylation is an important modification of recombinant proteins, because the attached oligosaccharide chains can significantly alter protein properties. Potential glycosylation sites are not always occupied with oligosaccharide, and site occupancy can change with the culture environment. To investigate the relationship between metabolism and glycosylation site occupancy, we studied the glycosylation of recombinant human interferon-γ(IFN-γ) produced in continuous culture of Chinese hamster ovary cells. Intracellular nucleotide sugar levels and IFN-γ glycosylation were measured at different steady states which were characterized by central carbon metabolic fluxes estimated by material balances and extracellular metabolite rate measurements. Although site occupancy varied over a rather narrow range, we found that differences correlated with the intracellular pool of UDP-N-acetylglucosamine + UDP-N-acetylgalactosamine (UDP-GNAc). Measured nucleotide levels and estimates of central carbon metabolic fluxes point to UTP depletion as the cause of decreased UDP-GNAc during glucose limitation. Glucose limited cells preferentially utilized available carbon for energy production, causing reduced nucleotide biosynthesis. Lower nucleoside triphosphate pools in turn led to lower nucleotide sugar pools and reduced glycosylation site occupancy. Subsequent experiments in batch and fed-batch culture have confirmed that UDP-sugar concentrations are correlated with UTP levels in the absence of glutamine limitation. Glutamine limitation appears to influence glycosylation by reducing amino sugar formation and hence UDP-GNAc concentration. The influence of nucleotide sugars on site occupancy may only be important during periods of extreme starvation, since relatively large changes in nucleotide sugar pools led to only minor changes in glycosylation. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 336-347, 1999.
Discount Rates for Time Versus Dates: The Sensitivity of Discounting to Time-Interval Description

Abstract Six experiments examine the impact of time-interval descriptions on consumers' discount rates. Consumers exhibit more discounting (e.g., they demand more money to delay income) when delay intervals are described by extents of time than when delay intervals are described by dates. This pattern holds in various contexts, including gains and losses, and is robust to response-mode changes. Findings further indicate that this effect may arise because, compared with date descriptions, extent descriptions enhance perceptions of interval length. The author discusses other potential mechanisms and implications.
Primary resonance excitation of electrically actuated clamped circular plates

We investigate the response of an electrically actuated clamped circular plate to a primary resonance excitation of its first axisymmetric mode using an analytical reduced-order model (macromodel). We discuss the inf luence of the number of modes retained in the discretization on the predicted solutions. The reduced-order model, which is a system of coupled nonlinear ordinary-dif ferential equations, accounts for general residual stress and strain hardening and allows for general material and geometric design variables. Our reduced-order model is robust up to the pull-in instability and is general enough to be an ef fective design tool for capacitive micromachined ultrasonic transducers.
Regulated temporal-spatial astrocyte precursor cell proliferation involves BRAF signalling in mammalian spinal cord

Expansion of astrocyte populations in the central nervous system is characteristic of evolutionarily more complex organisms. However, regulation of mammalian astrocyte precursor proliferation during development remains poorly understood. Here, we used Aldh1L1-GFP to identify two morphologically distinct types of proliferative astrocyte precursors: radial glia (RG) in the ventricular zone and a second cell type we call an ‘intermediate astrocyte precursor’ (IAP) located in the mantle region of the spinal cord. Astrogenic RG and IAP cells proliferated in a progressive ventral-to-dorsal fashion in a tight window from embryonic day 13.5 until postnatal day 3, which correlated precisely with the pattern of active ERK signalling. Conditional loss of BRAF function using BLBP-cre resulted in a 20% decrease in astrocyte production, whereas expression of activated BRAFV600E resulted in astrocyte hyperproliferation. Interestingly, BRAFV600E mitogenic effects in astrocytes were restricted, in part, by the function of p16INK4A-p19ARF, which limited the temporal epoch for proliferation. Together, these findings suggest that astrocyte precursor proliferation involves distinct RG and IAP cells; is subjected to temporal and spatial control; and depends in part on BRAF signalling at early stages of mammalian spinal cord development.
Supernovae, Pulsars, and Gamma-Ray Bursts: A Unified Picture

A scenario is proposed that explains both the observed high pulsar velocities and extragalactic gamma-ray bursts (GRBs). The model involves an ultrarelativistic jet from a supernova (SN) that produces a GRB and its afterglow, whose characteristics are similar to an isotropic fireball GRB perhaps with some differences at late times in the afterglow once some significant transverse diffusion has occurred. The timescales and many other properties of GRBs and their afterglows in this model are consistent with observations. GRBs in this model have special intrinsic properties, which can either falsify or prove this model unambiguously by observations. The most direct proof is the detection of an SN about the same time as the luminous GRB event. Most GRBs and SNe are expected occur at moderate redshift (z~1-3), if they follow the observed universal star formation history, as implied in this model. Searching for GRB/SN associations is a challenge because the majority of the SNe will be faint. Some additional, dramatic observable consequences are predicted, which can also be utilized to test the model.