cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimizing Large Join Queries in Mediation Systems

In data integration systems, queries posed to a mediator need to be translated into a sequence of queries to the underlying data sources. In a heterogeneous environment, with sources of diverse and limited query capabilities, not all the translations are feasible. In this paper, we study the problem of finding feasible and efficient query plans for mediator systems. We consider conjunctive queries on mediators and model the source capabilities through attribute-binding adornments. We use a simple cost model that focuses on the major costs in mediation systems, those involved with sending queries to sources and getting answers back. Under this metric, we develop two algorithms for source query sequencing - one based on a simple greedy strategy and another based on a partitioning scheme. The first algorithm produces optimal plans in some scenarios, and we show a linear bound on its worst case performance when it misses optimal plans. The second algorithm generates optimal plans in more scenarios, while having no bound on the margin by which it misses the optimal plans. We also report on the results of the experiments that study the performance of the two algorithms.
The standardization of bronchoscopic techniques for ventilator-associated pneumonia.

During the last decade, several centers have directed their research efforts at defining more efficient modalities for the accurate diagnosis ofventilatorassociated pneumonia (VAP). Accurate diagnosis is an essential prerequisite for clinical investigation. Initial studies, which correlated histologic findings and quantitative bacterial cultures of the lung with the findings of protected specimen brush cultures have stimulated clinical investigation of VAP Two diagnostic techniques, protected specimen brushing (PSB) and bronchoalveolar lavage (BAL), have been extensively investigated and have shown promising results. Advancements in the field, however, have been limited by the lack of standardization, particularly for BAL. In this communication, we attempt to standardize methodology for presently available bronchoscopic techniques and interpretation of data obtained by bronchoscopy to facilitate comparisons among investigations and to promote multicenter collaboration.
Bekenstein-Hawking Entropy as Topological Entanglement Entropy

Black holes in 2+1 dimensions enjoy long range topological interactions similar to those of non-abelian anyon excitations in a topologically ordered medium. Using this observation, we compute the topological entanglement entropy of BTZ black holes via the established formula Stop = log(S a 0 ), with S a b the modular S-matrix of the Virasoro characters a( ). We nd a precise match with the Bekenstein-Hawking entropy. This result adds a new twist to the relationship between quantum entanglement and the interior geometry of black holes. We generalize our result to higher spin black holes, and again nd a detailed match. We
Microvascular synthetic grafts

Expanded polytetrafluoroethylene (PTFE) was tested in rats as a microvascular synthetic graft. An inside diameter of 1.25 mm was used in the rat carotid artery, and various graft thicknesses were tried. Although several of the grafts remained patent, none of the samples tested were reliable enough to replace autologous vein graft.
WELFARE FLOWS AND CASELOAD DYNAMICS

Data from the 1990, 1991, 1992, 1993 and 1996 panels of the Survey of Income and Program Participations are used to estimate AFDC/TANF entry and exit rates. These estimates of AFDC/TANF entry and exit rates are used to conduct simulations aimed at determining the roles of economic conditions and welfare reform in explaining AFDC caseloads changes during the 1990s. The results of these simulations indicate that economic conditions were the engine driving the run-up in caseloads during the early 1990s and the decrease in caseloads following 1993.
Revenue Management Games: Horizontal and Vertical Competition

A well-studied problem in the literature on airline revenue (or yield) management is the optimal allocation of seat inventory among fare classes, given a demand distribution for each class. In practice, the seat allocation decisions of one airline affect the passenger demands for seats on other airlines. In this paper, we examine the seat inventory control problem under both horizontal competition (two airlines compete for passengers on the same flight leg) and vertical competition (different airlines fly different legs on a multileg itinerary). Such vertical competition can be the outcome of a code-sharing agreement between airlines, because each airline sells seats on the partner airlines' flights but the airlines are unwilling, or unable, to coordinate yield management decisions. We provide a general sufficient condition under which a pure-strategy Nash equilibrium exists in these revenue management games, and we also compare the total number of seats available in each fare class with, and without, competition. Analytical results as well as numerical examples demonstrate that more seats are protected for higher-fare passengers under horizontal competition than when a single airline acts as a monopoly. Under vertical competition the booking limit may be higher or lower, however, than the monopoly level, depending on the demand for connecting flights in each fare class. Finally, we discuss revenue-sharing contracts that coordinate the actions of both airlines.
Synchronization and communication costs of loop partitioning on shared-memory multiprocessor systems

The author presents strategies for static loop decomposition and scheduling as well as computer-assisted run-time scheduling that take into account, in addition to the cost of performing operations, the overhead costs associated with a decomposition and schedule. An algorithm for static decomposition of multidimensional loops based on the operation execution costs, communication costs, and synchronization costs is discussed. Synchronization instructions are introduced to ensure correct program execution following program decomposition. An algorithm for determining the explicit synchronization instruction that should be introduced to ensure correct execution of a program with arbitrarily nested loops is presented. Techniques for reducing run-time scheduling and communication and synchronization costs due to self-scheduling of multidimensional loops are also presented. Experiments performed on the Encore multiprocessor system demonstrate that the techniques developed can reduce overhead costs. >
The IBM RT06s evaluation system for speech activity detection in CHIL seminars

In this paper, we describe the IBM system submitted to the NIST Rich Transcription Spring 2006 (RT06s) evaluation campaign for automatic speech activity detection (SAD). This SAD system has been developed and evaluated on CHIL lecture meeting data using far-field microphone sensors, namely a single distant microphone (SDM) configuration and a multiple distant microphone (MDM) condition. The IBM SAD system employs a three-class statistical classifier, trained on features that augment traditional signal energy ones with features that are based on acoustic phonetic likelihoods. The latter are obtained using a large speaker-independent acoustic model trained on meeting data. In the detection stage, after feature extraction and classification, the resulting sequence of classified states is further collapsed into segments belonging to only two classes, speech or silence, following two levels of smoothing. In the MDM condition, the process is repeated for every available microphone channel, and the outputs are combined based on a simple majority voting rule, biased towards speech. The system performed well at the RT06s evaluation campaign, resulting to 8.62% and 5.01% “speaker diarization error” in the SDM and MDM conditions respectively.
Deadbeat controlled PWM inverter with parameter estimation using only voltage sensor

A technique based on deadbeat control theory is proposed to obtain a nearly sinusoidal PWM (pulsewidth-modulated) inverter output voltage using only a voltage sensor. The closed loop sampled-data feedback scheme inherently results in very fast response to load disturbance and nonlinear load, producing low total harmonic distortion. Parameter estimation of the plant provides a type of self-tuning of the proposed controller. A theoretical analysis, simulation, and experimental results are presented for a single-phase PWM inverter controlled by an Intel 8086 microprocessor. >
Effect of universal health coverage on marriage, cohabitation and labor force participation

This paper examines the impact of universal health coverage on cohabitation, marriage, and labor force participation. Economic gains from marriage when non-labor income increases among partners. I use the expansion of non-contributory health insurance in Mexico to test this. This insurance scheme, called Seguro Popular (SP), provides a minimum set of health benefits to the population not covered by formal social security. The rollout of SP started in 2002 across municipalities. This variation makes possible examine the effect of health insurance on marital status among workers. The analysis of this paper shows that non-contributory health insurance coverage has a significant negative effect on the probability of marriage among poor and low educated males and females, and a positive effect on the probability of cohabitation. SP, however, has no effect on labor force participation.
The dependence identification neural network construction algorithm

An algorithm for constructing and training multilayer neural networks, dependence identification, is presented in this paper. Its distinctive features are that (i) it transforms the training problem into a set of quadratic optimization problems that are solved by a number of linear equations, (ii) it constructs an appropriate network to meet the training specifications, and (iii) the resulting network architecture and weights can be further refined with standard training algorithms, like backpropagation, giving a significant speedup in the development time of the neural network and decreasing the amount of trial and error usually associated with network development.
Smart Aggregate-Based Damage Detection of Circular RC columns under Cyclic Combined Loading

Structural health monitoring is an important issue for the maintenance of large-scale civil infrastructures, especially for bridge columns. In this paper, an innovative piezoceramic-based approach is developed for the structural health monitoring of reinforced concrete columns. An innovative piezoceramic-based device, the smart aggregate, is utilized as a transducer for the purpose of health monitoring. To investigate the seismic behavior of reinforced concrete (RC) bridge columns, structural health monitoring tests were performed on two bridge columns under combined reversed cyclic loading at the Missouri University of Science and Technology. The proposed smart aggregate based approach successfully evaluated the health status of concrete columns during the loading procedure. Sensor energy plots and 3D normalized sensor energy plots demonstrated that the damage inside attenuated the transmitted energy. The wavelet packet based damage index and sensor history damage index evaluate the damage development in concrete columns under cyclic loading.
A Theory of Dividends Based on Tax Clienteles

This paper explains why some firms prefer to pay dividends rather than repurchase shares. When institutional investors are relatively less taxed than individual investors, dividends induce “ownership clientele” effects. Firms paying dividends attract relatively more institutions, which have a relative advantage in detecting high firm quality and in ensuring firms are well managed. The theory is consistent with some documented regularities, specifically both the presence and stickiness of dividends, and offers novel empirical implications, e.g., a prediction that it is the tax difference between institutions and retail investors that determines dividend payments, not the absolute tax payments. ALTHOUGH A NUMBER OF THEORIES have been put forward in the literature to explain their pervasive presence, 1 dividends remain one of the thorniest puzzles in corporate finance. In a frictionless world without taxes or transaction costs, dividends and share repurchases are equivalent. If dividends are taxed more heavily than capital gains, as is the case in the United States and many other countries, share repurchases are apparently superior to dividends. Nevertheless, dividends continue to be a substantial proportion of earnings—and personal dividend taxes continue to be a substantial source of income for the I.R.S. For the 1973 to 1983 period, dividends for the largest 1,000 firms in the United States averaged 44 percent of earnings whereas repurchases averaged only 6 percent ~see Allen and Michaely ~1995!!. Although, as Bagwell and Shoven ~1989! have stressed, repurchases increased significantly in 1984 and have remained high, repurchases were not a substitute for dividends. From 1984 to 1988, repurchases increased from 6 percent to 38 percent of earnings, but dividends still increased from 44 percent to 51 percent. The I.R.S. Statistics of Income publication documents that taxable dividends in adjusted gross income amounted to $82 billion in about
Using k-Interactive Measure in Optimization-Based Data Mining

Optimization-based methods have been used for data separation in different domains and applications since 1960s. The commonality of those methods is to separate data by minimizing the overlapping between the groups and regard contribution from all the attributes toward the target of classification is the sum of every single attribute. However, the interaction among the attributes in the data is not considered at all. The theory of non-additive measures is used to describe those interactions. The consideration of the interactions is a breakthrough for dealing with the nonlinearity of data. Through the non-additive measure has been successfully utilized in optimization-based classification, it increases the computation cost as well as the quadratic programming models particularly designed for dealing with the nonlinearity. In this paper, we proposed the optimization-based classification method with the signed k-interactive measure. The experimental results shows that it successfully reduced the computation but retained the classification power.
Improved Methods for Analysis of Decadal Elevation-Change Time Series Over Antarctica

In this paper, several techniques to improve the processing and analysis of decadal elevation-change time series (ECTS) constructed using satellite radar altimeter data over the Antarctic ice sheet are described. First, a method that improves both the quality and quantity of ice-sheet ECTS is introduced. By dynamically selecting the reference month used in constructing ECTS for a given local region, the maximum number of elevation-change estimates are used in a matrix processing technique. This can improve ECTS quality while also generating ECTS in new areas, leading to a significant increase in spatial coverage. Next, an improved autoregressive (IAR) approach is presented for modeling nonlinear medium-period variations in decadal Antarctic ECTS. This builds upon previous work where an AR model was used to characterize seasonal and interannual variations in ice-sheet ECTS. The improved approach avoids overdecomposition by adopting an iterative local average filter to estimate nonlinear medium-period trends. Monte Carlo simulations show that the IAR method significantly outperforms the AR method when realistic nonlinear trends are present. Because of these characteristics, the IAR model is able to adequately characterize seasonal, interannual, and medium-period nonlinear signals present in decadal ECTS and extract their long-term trends with very small error. This is important for accurate measurement of decadal elevation change over the Antarctic ice sheet and for assessing the impact of these changes on the global sea level
Reduced-order simulation of large accelerator structures

Simulating electromagnetic waves inside finite periodic or almost periodic three-dimensional structures is important to research in linear particle acceleration, high power microwave generation, and photonic band gap structures. While eigenmodes of periodic structures can be determined from analysis of a single unit cell, based on Floquet theory, the general case of aperiodic structures, with defects or nonuniform properties, typically requires 3D electromagnetic simulation of the entire structure. When the structure is large and high accuracy is necessary this can require high-performance computing techniques to obtain even a few eigenmodes [Z. Li et al., Nucl. Instrum. Methods Phys. Res., Sect. A 558, 168 (2006)]. To confront this problem, we describe an efficient, field-based algorithm that can accurately determine the complete eigenmode spectrum for extended aperiodic structures, up to some chosen frequency limit. The new method combines domain decomposition with a nontraditional, dual eigenmode repre...
An empirical investigation of nonlinear energy transfer from the M2 internal tide to diurnal wave motions in the Kauai Channel, Hawaii

Current profiles are examined for evidence of nonlinear energy transfers from the M2 internal tide to diurnal waves. The 6 month records, unlike shorter records, produce well-resolved velocity and shear spectra that consistently exhibit maxima at the diurnal tides O1 and K1, with a minimum at the intermediate M2 subharmonic, M2/2. The ratio of velocity spectral energy at M2/2 and M2 is quantified, providing a needed modeling benchmark. Bispectra and bicoherences imply a negligible [−M2/2, −M2/2, −M2] triad interaction, but possibly a significant interaction for the [−O1, −K1, −M2] triad. Numerical simulations, however, indicate that O1 and K1 signals are from internal tides. Tests with synthetic data, linear tides plus random noise, reveal that bispectrum and bicoherence estimators can yield significant values, thus misleading results. Therefore, resolving the diurnal tides from M2/2 is essential to meaningfully assess nonlinear transfer of energy from M2 to diurnal waves.
Effect of cricopharyngeus muscle surgery on the pharynx

Objectives/Hypothesis: Cricopharyngeus muscle dysfunction (CPD) ranges from asymptomatic cricopharyngeal bar (CPB) to Zenker's diverticulum. Previous work suggests that CPD can result in dilation and weakening of the pharynx above the obstruction. The purpose of this investigation was to evaluate the ability of surgery on the cricopharyngeus muscle to improve pharyngeal area and strength. Study Design: Retrospective case study. Methods: Videofluoroscopic swallowing studies of all persons with CPD who underwent cricopharyngeus (CP) intervention followed by routine postoperative fluoroscopic study, between October 1, 1999 and January 1, 2010 were reviewed. Objective measures of pharyngeal area and constriction were obtained from pretreatment and post-treatment studies. Paired t tests and repeated measures analysis of variance were employed to compare results. Results: Fifty-four patients were included. Pharyngeal constriction and pharyngoesophageal segment (PES) opening improved significantly after intervention (P .05). PES opening improved more with CP myotomy than with dilation and botulinum toxin. Conclusions: Relief of CP obstruction by surgery or dilation improves pharyngeal constriction and PES opening. Dilation of the pharynx possibly related to prolonged outlet obstruction does not improve. CP myotomy appears more effective than dilation or botulinum toxin in relieving obstruction. Laryngoscope, 2010
Characteristic and Ehrhart Polynomials

Let A be a subspace arrangement and let χ(A,t) be the characteristic polynomial of its intersection lattice L( A). We show that if the subspaces in A are taken from L(B_n), where B_n is the type B Weyl arrangement, then χ(A,t) counts a certain set of lattice points. One can use this result to study the partial factorization of χ(A,t) over the integers and the coefficients of its expansion in various bases for the polynomial ring R[t]. Next we prove that the characteristic polynomial of any Weyl hyperplane arrangement can be expressed in terms of an Ehrhart quasi-polynomial for its affine Weyl chamber. Note that our first result deals with all subspace arrangements embedded in B_n while the second deals with all finite Weyl groups but only their hyperplane arrangements.
Recurrent competition explains temporal effects of attention in MSTd

Navigation in a static environment along straight paths without eye movements produces radial optic flow fields. A singularity called the focus of expansion (FoE) specifies the direction of travel (heading) of the observer. Cells in primate visual area MSTd respond to radial fields and are therefore thought to be heading-sensitive. Humans frequently shift their focus of attention while navigating, for example, depending on the favorable or threatening context of approaching independently moving objects. Recent neurophysiological studies show that the spatial tuning curves of primate MSTd neurons change based on the difference in visual angle between an attentional prime and the FoE. Moreover, the peak mean population activity in MSTd retreats linearly in time as the distance between the attentional prime and FoE increases. We present a dynamical neural circuit model that demonstrates the same linear temporal peak shift observed electrophysiologically. The model qualitatively matches the neuron tuning curves and population activation profiles. After model MT dynamically pools short-range motion, model MSTd incorporates recurrent competition between units tuned to different radial optic flow templates, and integrates attentional signals from model area FEF. In the model, population activity peaks occur when the recurrent competition is most active and uncertainty is greatest about the relative position of the FoE. The nature of attention, multiplicative or non-multiplicative, is largely irrelevant, so long as attention has a Gaussian-like profile. Using an appropriately tuned sigmoidal signal function to modulate recurrent feedback affords qualitative fits of deflections in the population activity that otherwise appear to be low-frequency noise. We predict that these deflections mark changes in the balance of attention between the priming and FoE locations.
Dialkylbiaryl Phosphines in Pd-Catalyzed Amination: A User's Guide.

Dialkylbiaryl phosphines are a valuable class of ligand for Pd-catalyzed amination reactions and have been applied in a range of contexts. This perspective attempts to aid the reader in the selection of the best choice of reaction conditions and ligand of this class for the most commonly encountered and practically important substrate combinations.
HLA class I nucleotide sequences, 1991

The HLA class I sequences included in this compilation are taken from publications listed in the accompanying paper, Nomenclature for factors of the HLA system, 1990 (Bodmer et al. 1991) and Nomeclature for factors of the HLA system, 1989 (Bodmer et al. 1990). Where discrepancies have arisen between reported sequences the original authors have been contavted where possible, and necessary amendments to published sequences have been incorporated into this alignment. Future sequencing may identify errors in this list and we would welcome any evidence that helps to maintain the accuracy of this compilation. In the sequence alignments identify between residues is indicated by a hyphen (-). Unavailable sequence is indicated by a period (.). Gaps in the sequence are inserted to maintain the alignment between different alleles showing variation in amino acid number.
THE ORIGIN OF THE ELEMENTS.

It is my privilege to begin our consideration of the history of the universe during this first scientific session of the Academy Centennial with a discussion of the origin of the elements of which the matter of the universe is constituted. The question of the origin of the elements and their numerous isotopes is the modern expression of one of the most ancient problems in science. The early Greeks thought that all matter consisted of the four simple substances -- air, earth, fire, and water -- and they, too, sought to know the ultimate origin of what for them were the elementary forms of matter. They also speculated that matter consists of very small, indivisible, indestructible, and uncreatable atoms. They were wrong in detail but their concepts of atoms and elements and their quest for origins persist in our science today.
Effects of Spanwise Blowing on Two Fighter Airplane Configurations

NASA Langley Research Center has recently conducted an investigation to determine the effects of spanwise blowing on two configurations representative of current fighter airplanes. This research examined not only the longitudinal or performance effects but was especially oriented toward determining the lateral-directional effects, particularly in the stall/departure angle-of-attack range. The wind-tunnel tests included measurement of static and forced-oscillation aerodynamic data, visualization of the airflow changes over the wing created by the spanwise blowing, and free-flight model tests. Effects of blowing rate, chordwise location of the blowing ports, asymmetric blowing, and the effects of blowing on the effectiveness of conventional aerodynamic controls were investigated.
Crack Healing in UO2

Isothermal annealing of thermally shocked UO2 bars (O/M= 2.00 ±0.01) at 1600°, 1800°, and 2000°C caused crack healing, which was determined from recovery of room-temperature fracture strength. The activation energy for crack healing was ∼0.5 of that for volume diffusion, and healing occurred at the same rate as grain growth. This result has important implications with respect to crack healing in oxide fuels during in-reactor restructuring.
Targeting the Insulin Growth Factor and the Vascular Endothelial Growth Factor Pathways in Ovarian Cancer

Antiangiogenic therapy is emerging as a highly promising strategy for the treatment of ovarian cancer, but the clinical benefits are usually transitory. The purpose of this study was to identify and target alternative angiogenic pathways that are upregulated in ovarian xenografts during treatment with bevacizumab. For this, angiogenesis-focused gene expression arrays were used to measure gene expression levels in SKOV3 and A2780 serous ovarian xenografts treated with bevacizumab or control. Reverse transcription-PCR was used for results validation. The insulin growth factor 1 (IGF-1) was found upregulated in tumor and stromal cells in the two ovarian xenograft models treated with bevacizumab. Cixutumumab was used to block IGF-1 signaling in vivo. Dual anti-VEGF and IGF blockade with bevacizumab and cixutumumab resulted in increased inhibition of tumor growth. Immunohistochemistry measured multivessel density, Akt activation, and cell proliferation, whereas terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay measured apoptosis in ovarian cancer xenografts. Bevacizumab and cixutumumab combination increased tumor cell apoptosis in vivo compared with therapy targeting either individual pathway. The combination blocked angiogenesis and cell proliferation but not more significantly than each antibody alone. In summary, IGF-1 activation represents an important mechanism of adaptive escape during anti-VEGF therapy in ovarian cancer. This study provides the rationale for designing bevacizumab-based combination regimens to enhance antitumor activity.
Intellectual Property Rights, Genetic Use Restriction Technologies (GURTs), and Strategic Behavior

This article discusses the mutual reinforcement effects of IPRs and biotechnology in recent years, and review the development of GURTs and how the major agricultural biotechnology companies behave in that regard. Both proponents and opponents of GURTs made strong arguments based on speculations. We discuss the major arguments by both sides, and argue the possible strategic use of bundling and licensing strategy by the biotech giants, because GURTs make it possible for a seed to be marketed as a vector of trait options. We also examine the validity of two major implicit assumptions held by those opposing GURTs: patenting does not affect the monopoly power of GURTs; and GURTs would take over the GM seed market.
Spectral features of solar wind turbulent plasma

Spectral properties of a fully compressible solar wind Hall magnetohydrodynamic (HMHD) plasma are investigated by means of time dependent three-dimensional (3D) HMHD simulations. Our simulations, in agreement with spacecraft data, identify a spectral break in turbulence spectra at characteristic length-scales associated with electromagnetic fluctuations that are smaller than the ion gyroradius. In this regime, our 3D simulations show that turbulent spectral cascades in the presence of a mean magnetic field follow an omnidirectional anisotropic inertial range spectrum close to k -7/3 . The onset of the spectral break in our simulations can be ascribed to the presence of non-linear Hall interactions that modify the spectral cascades. Our simulations further show that the underlying characteristic turbulent fluctuations are spectrally anisotropic, the extent of which depends critically on the local wavenumber. The fluctuations associated with length-scales smaller than the ion gyroradius are highly compressible and tend to exhibit a near equipartition in the velocity and magnetic fields. Finally, we find that the orientation of velocity and magnetic field fluctuations critically determine the character of non-linear interactions that predominantly govern a HMHD plasma, like the solar wind.
Examining gravitational collapse with test scalar fields

Numerical simulations are performed of a test scalar field in a spacetime undergoing gravitational collapse. The behavior of the scalar field near the singularity is examined and implications for generic singularities are discussed. In particular, our example is the first confirmation of the Belinskii, Khalatnikov and Lifschitz (BKL) conjecture for an asymptotically flat spacetime.
Discovery of a Second L Subdwarf in the Two Micron All Sky Survey

I report the discovery of the second L subdwarf identified in the Two Micron All Sky Survey, 2MASS J162620343925190. This high proper motion object ( yr 1 ) exhibits near-infrared spectral m p 1 .27 0 .03 features indicative of a subsolar metallicity L dwarf, including strong metal hydride and H 2O absorption bands, pressure-broadened alkali lines, and blue near-infrared colors caused by enhanced collision-induced H 2 absorption. This object is of later type than any of the known M subdwarfs but does not appear to be as cool as the apparently late-type sdL 2MASS 05328246. The radial velocity ( km s 1 ) and estimated tangential V p 260 35 rad velocity ( km s 1 ) of 2MASS 16263925 indicate membership in the Galactic halo, and this source V ≈ 90–210 tan is likely near or below the hydrogen-burning minimum mass for a metal-poor star. L subdwarfs such as 2MASS 16263925 are useful probes of gas and condensate chemistry in low-temperature stellar and brown dwarf atmospheres, but more examples are needed to study these objects as a population as well as to define a rigorous classification scheme.
The Occurrence and Architecture of Exoplanetary Systems

The basic geometry of the Solar System—the shapes, spacings, and orientations of the planetary orbits—has long been a subject of fascination as well as inspiration for planet-formation theories. For exoplanetary systems, those same properties have only recently come into focus. Here we review our current knowledge of the occurrence of planets around other stars, their orbital distances and eccentricities, the orbital spacings and mutual inclinations in multiplanet systems, the orientation of the host star's rotation axis, and the properties of planets in binary-star systems.
Observed structure of addresses in IP traffic

We investigate the structure of addresses contained in IPv4 traffic--specifically, the structural characteristics of destination IP addresses seen on Internet links, considered as a subset of the address space. These characteristics have implications for algorithms that deal with IP address aggregates, such as routing lookups and aggregate-based congestion control. Several example address structures are well modeled by multifractal Cantor-like sets with two parameters. This model may be useful for simulations where realistic IP addresses are preferred. We also develop concise characterizations of address structures, including active aggregate counts and discriminating prefixes. Our structural characterizations are stable over short time scales at a given site, and different sites have visibly different characterizations, so that the characterizations make useful "fingerprints" of the traffic seen at a site. Also, changing traffic conditions, such as worm propagation, significantly alter these fingerprints.
Measurement of glyoxal using an incoherent broadband cavity enhanced absorption spectrometer

We describe an instrument for simultaneous measurements of glyoxal (CHOCHO) and nitrogen dioxide (NO 2 ) using cavity enhanced absorption spectroscopy with a broadband light source. The output of a Xenon arc lamp is coupled into a 1 m optical cavity, and the spectrum of light exiting the cavity is recorded by a grating spectrometer with a charge-coupled device (CCD) array detector. The mirror reflectivity and effective path lengths are determined from the known Rayleigh scattering of He and dry zero air (N 2 +O 2 ). Least-squares fitting, using published reference spectra, allow the simultaneous retrieval of CHOCHO, NO 2 , O 4 , and H 2 O in the 441 to 469 nm spectral range. For a 1-min sampling time, the precision (±1σ) on signal for measurements of CHOCHO and NO 2 is 29 pptv and 20 pptv, respectively. We directly compare measurements made with the incoherent broadband cavity enhanced absorption spectrometer with those from cavity ringdown instruments detecting CHOCHO and NO 2 at 404 and 532 nm, respectively, and find linear agreement over a wide range of concentrations. The instrument has been tested in the laboratory with both synthetic and real air samples, and the demonstrated sensitivity and specificity suggest a strong potential for field measurements of both CHOCHO and NO 2 .
Ultraviolet Imaging Polarimetry of the Large Magellanic Cloud. II. Models

Motivated by new sounding-rocket wide-field polarimetric images of the Large Magellanic Cloud (reported simultaneously by Cole et al.), we have used a three-dimensional Monte Carlo radiation transfer code to investigate the escape of near-ultraviolet photons from young stellar associations embedded within a disk of dusty material (i.e., a galaxy). As photons propagate through the disk, they may be scattered or absorbed by dust. Scattered photons are polarized and tracked until they escape the dust layer, allowing them to be observed; absorbed photons heat the dust, which radiates isotropically in the far-infrared where the galaxy is optically thin. The code produces four output images: near-UV and far-IR flux, and near-UV images in the linear Stokes parameters Q and U. From these images we construct simulated UV polarization maps of the LMC. We use these maps to place constraints on the star+dust geometry of the LMC and the optical properties of its dust grains. By tuning the model input parameters to produce maps that match the observed polarization maps, we derive information about the inclination of the LMC disk to the plane of the sky and about the scattering phase function g. We compute a grid of models with i = 28°, 36°, and 45°, and g = 0.64, 0.70, 0.77, 0.83, and 0.90. The model that best reproduces the observed polarization maps has i = 36° and g ≈ 0.7. Because of the low signal-to-noise in the data, we cannot place firm constraints on the value of g. The highly inclined models do not match the observed centrosymmetric polarization patterns around bright OB associations or the distribution of polarization values. Our models approximately reproduce the observed ultraviolet photopolarimetry of the western side of the LMC; however, the output images depend on many input parameters and are nonunique. We discuss some of the limitations of the models and outline future steps to be taken; our models make some predictions regarding the polarization properties of diffuse light across the rest of the LMC.
Psychiatric co-morbidity is Associated with Increased risk of Surgery in Crohn’s disease

SummaryBackground Psychiatric co-morbidity, in particular major depression and anxiety, is common in patients with Crohn's disease (CD) and ulcerative colitis (UC). Prior studies examining this may be confounded by the co-existence of functional bowel symptoms. Limited data exist examining an association between depression or anxiety and disease-specific endpoints such as bowel surgery. Aims To examine the frequency of depression and anxiety (prior to surgery or hospitalisation) in a large multi-institution electronic medical record (EMR)-based cohort of CD and UC patients; to define the independent effect of psychiatric co-morbidity on risk of subsequent surgery or hospitalisation in CD and UC, and to identify the effects of depression and anxiety on healthcare utilisation in our cohort. Methods Using a multi-institution cohort of patients with CD and UC, we identified those who also had co-existing psychiatric co-morbidity (major depressive disorder or generalised anxiety). After excluding those diagnosed with such co-morbidity for the first time following surgery, we used multivariate logistic regression to examine the independent effect of psychiatric co-morbidity on IBD-related surgery and hospitalisation. To account for confounding by disease severity, we adjusted for a propensity score estimating likelihood of psychiatric co-morbidity influenced by severity of disease in our models. Results A total of 5405 CD and 5429 UC patients were included in this study; one-fifth had either major depressive disorder or generalised anxiety. In multivariate analysis, adjusting for potential confounders and the propensity score, presence of mood or anxiety co-morbidity was associated with a 28% increase in risk of surgery in CD (OR: 1.28, 95% CI: 1.03–1.57), but not UC (OR: 1.01, 95% CI: 0.80–1.28). Psychiatric co-morbidity was associated with increased healthcare utilisation. Conclusions Depressive disorder or generalised anxiety is associated with a modestly increased risk of surgery in patients with Crohn's disease. Interventions addressing this may improve patient outcomes.
The Effects of Macroeconomic Announcements on Commodity Prices

This article analyzes the immediate reaction of a representative sample of commodity prices and two T-bill yields to the unanticipated components of thirteen macroeconomic announcements. Surprises in the monetary variables cause the majority of the significant commodity price responses; while these plus other cyclical surprises, such as the unemployment rate, cause significant lumber and T-bill reactions. The results provide strong support for the policy anticipations hypothesis and against the inflationary expectations hypothesis, i.e., that monetary surprises cause changes in real interest rates rather than in nominal rates only as the inflationary expectations hypothesis contends.
Sparsity-Leveraging Reconfiguration of Smart Distribution Systems

A system reconfiguration problem is considered for three-phase power distribution networks featuring distributed generation. In lieu of binary line selection variables, the notion of group sparsity is advocated to re-formulate the nonconvex distribution system reconfiguration (DSR) problem into a convex one. It is shown that the line selection task boils down to a shrinkage and thresholding operation on the line currents. Further, numerical tests illustrate the ability of the proposed scheme to identify meshed, weakly meshed, or even radial configurations by adjusting a sparsity-tuning parameter in the DSR cost. Constraints on the voltages are investigated and incorporated in the novel DSR problem to facilitate voltage regulation.
Evolutionary conservation of the folding nucleus.

Here, we present statistical analysis of conservation profiles in families of homologous sequences for nine proteins whose folding nucleus was determined by protein engineering methods. We show that in all but one protein (AcP) folding nucleus residues are significantly more conserved than the rest of the protein. Two aspects of our study are especially important: (i) grouping of amino acid residues into classes according to their physical-chemical properties and (ii) proper normalization of amino acid probabilities that reflects the fact that evolutionary pressure to conserve some amino acid types may itself affect concentration of various amino acid types in protein families. Neglect of any of those two factors may make physical and biological "signals" from conservation profiles disappear.
Equilibrium Distributions of Sales and Advertising Prices

Focuses on the formulation of equilibrium distributions of sales and advertising prices. Development of a model in which sellers have constant average cost curves; Approach to prove assumptions on consumer preferences; Description of the basic model of consumer pricing. (Из Ebsco)
Accounting for Management in Cost of Livestock Disease Studies

Assessing the impacts of livestock disease on productivity is enhanced when the management abilities of producers are taken into consideration. One method of doing this is to develop a management index of several production/marketing practices using correspondence analysis which can combine several practices into a few variables. Also, through correspondence analysis herds can be divided into better managed and more poorly managed herds to test the association of management on herd health, productivity, and profitability.
Alternate Heegaard genus bounds distance

Suppose M is a compact orientable irreducible 3-manifold with Heegaard splitting surfaces P and Q. Then either Q is isotopic to a possibly stabilized or boundary-stabilized copy of P or the distance d(P)<= 2genus (Q). More generally, if P and Q are bicompressible but weakly incompressible connected closed separating surfaces in M then either P and Q can be well-separated or P and Q are isotopic or d(P)<= 2genus (Q).
Can Higher-Achieving Peers Explain the Benefits to Attending Selective Schools?: Evidence from Trinidad and Tobago

Abstract Using exogenous secondary school assignments to remove self-selection bias to schools and peers within schools, I credibly estimate both (1) the effect of attending schools with higher-achieving peers, and (2) the direct effect of short-run peer quality improvements within schools, on the same population. While students at schools with higher-achieving peers have better academic achievement, within-school short-run increases in peer achievement improve outcomes only at high-achievement schools. Short-run (direct) peer quality accounts for only one tenth of school value-added on average, but at least one-third among the most selective schools. There are large and important differences by gender.
FDTD modeling of noise in computer packages

In this paper, we discuss the electromagnetic modeling of the components of a computer package that contribute to noise on the signal lines in computer packages. We obtain equivalent circuits of coupled transmission lines, discontinuities in transmission lines, and a parallel-plate power plane configuration. These equivalent circuits allow one to use a circuit simulator to model the crosstalk, reflection, and simultaneous switching noises that are common in computer packages. The finite difference time domain (FDTD) algorithm is used to obtain the full-wave electromagnetic field solutions from which the equivalent circuits are determined. >
Accelerating MCMC via parallel predictive prefetching

Parallel predictive prefetching is a new framework for accelerating a large class of widely-used Markov chain Monte Carlo (MCMC) algorithms. It speculatively evaluates many potential steps of an MCMC chain in parallel while exploiting fast, iterative approximations to the target density. This can accelerate sampling from target distributions in Bayesian inference problems. Our approach takes advantage of whatever parallel resources are available, but produces results exactly equivalent to standard serial execution. In the initial burn-in phase of chain evaluation, we achieve speedup close to linear in the number of available cores.
Equity Price Bubbles in the Middle Eastern and North African Financial Markets

Abstract We empirically investigate the existence of periodically collapsing bubbles in seven Middle East and North African (MENA) financial markets for the period ending in May 2009. We use the Taylor and Peel (1998) residual augmented least square Dickey and Fuller test (RALS DF) to detect the bubbles. We find that the hypothesis of a bubble formation cannot be rejected for all seven markets investigated in our study, leading us to believe that in fact there has been a break down in the cointegration relationship between real equity prices and real dividends and also between real market capitalizations and real dividends.
New One-Pot Methodologies for the Modification or Synthesis of Alkaloid Scaffolds

There are several avenues by which promising bioactive natural products can be produced in sufficient quantities to enable lead optimization and medicinal chemistry studies. The total synthesis of natural products is an important, but sometimes difficult, approach and requires the development of innovative synthetic methodologies to simplify the synthesis of complex molecules. Various classes of natural product alkaloids are both common and widely distributed in plants, bacteria, fungi, insects and marine organisms. This mini-review will discuss the scope, mechanistic insights and enantioselectivity aspects of selected examples of recently developed one-pot methods that have been published in 2009 for the synthesis of substituted piperidines, quinolizidines, pyrrolidines, hexahydropyrrolizines, octahydroindolizines and γ-lactams. In addition, progress on the synthesis of β-carboline (manzamine) alkaloids will also be discussed.
STABILITY OF PERIODIC SOLUTIONS OF CONSERVATION LAWS WITH VISCOSITY: ANALYSIS OF THE EVANS FUNCTION

Nonclassical conservation laws with viscosity arising in multiphase fluid and solid mechanics exhibit a rich variety of traveling-wave phenomena, including homoclinic (pulse-type) and periodic solutions along with the standard heteroclinic (shock, or front-type) solutions. Here, we investigate stability of periodic traveling waves within the abstract Evans-function framework established by R. A. Gardner. Our main result is to derive a useful stability index analogous to that developed by Gardner and Zumbrun in the traveling-front or -pulse context, giving necessary conditions for stability with respect to initial perturbations that are periodic on the same period T as the traveling wave; moreover, we show that the periodic-stability index has an interpretation analogous to that of the traveling-front or -pulse index in terms of well-posedness of an associated Riemann problem for an inviscid medium, now to be interpreted as allowing a wider class of measure-valued solutions or, alternatively, in terms of existence and nonsingularity of a local “mass map” from perturbation mass to potential time-asymptotic T-periodic states. A closely related calculation yields also a complementary long-wave stability criterion necessary for stability with respect to periodic perturbations of arbitrarily large period NT, N → ∞. We augment these analytical results with numerical investigations analogous to those carried out by Brin in the traveling-front or -pulse case, approximating the spectrum of the linearized operator about the wave.