cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Capacity of Memoryless Relay Networks

In a relay network, the signal processing at the relay significantly affects the capacity benefits of cooperation. In this work, we explore the optimal relay functionality for capacity maximization in a memoryless relay network, i.e. a network where, during each channel use, the signal transmitted by a relay depends only on the last received symbol at that relay. By relating some of the existing memoryless forwarding strategies to the fundamental signal processing operations of estimation and detection, we develop a new scheme that forwards the unconstrained minimum mean square error (MMSE) estimate obtained at the relay to the destination. For a single relay system, we derive the characterization of the optimal relay function and show that the relay function of EF (estimate and forward) satisfies the optimality condition. For the multiple relay case, we consider both parallel and serial relay networks and show that EF performs better than both AF (amplify and forward) and DF (demodulate and forward). For hybrid networks that contain both serial and parallel elements, and when robust performance is desired at all SNR, the advantage of EF over the best of AF and DF is found to be significant.
How to improve the quality of genetic counselling

Background: Genetic tests are used increasingly to improve the diagnostics and risk assessment. Th is has led to a growing need for genetic counselling, which helps patients understand genetics and genetic testing in their life situations. As genetic testing is oft en performed abroad, the need for harmonisation and quality issues of genetic testing process, including genetic counselling, on European level has been emphasized. Genetic counselling by appropriately trained professionals is indicated in many situations involving rare diseases: new diagnosis in the family, predictive or carrier testing and when considering prenatal or preimplantation diagnostics. On the other hand, comprehensive genetic counselling is usually not needed in situations related to risk profi ling of common multifactorial diseases, pharmacogenetic testing or screening programs. Discussion on how to divide the work should continue. Developing tools for evaluating the quality of genetic services is underway as part of Eurogentest activities. Conclusions: Th e need for genetic information including comprehensive genetic counselling is growing. Ample resources for genetic centres should be safeguarded and tools for evaluating the quality of genetic services should be developed. Simultaneously, all health care professionals should be appropriately trained to inform their patients about genetics and genetic testing and to refer them to comprehensive genetic counselling when indicated.
Divide-and-Permute

Abstract We construct “simple” games implementing in Nash equilibria several solutions to the problem of fair division. These solutions are the no-envy solution, which selects the allocations such that no agent would prefer someone else's bundle to his own, and several variants of this solution. Components of strategies can be interpreted as allocations, consumption bundles, permutations, points in simplices of dimensionalities equal to the number of goods or to the number of agents, and integers. We also propose a simple game implementing the Pareto solution and games implementing the intersections of the Pareto solution with each of these solutions.
Reversible data hiding

A novel reversible data hiding algorithm, which can recover the original image without any distortion from the marked image after the hidden data have been extracted, is presented in this paper. This algorithm utilizes the zero or the minimum points of the histogram of an image and slightly modifies the pixel grayscale values to embed data into the image. It can embed more data than many of the existing reversible data hiding algorithms. It is proved analytically and shown experimentally that the peak signal-to-noise ratio (PSNR) of the marked image generated by this method versus the original image is guaranteed to be above 48 dB. This lower bound of PSNR is much higher than that of all reversible data hiding techniques reported in the literature. The computational complexity of our proposed technique is low and the execution time is short. The algorithm has been successfully applied to a wide range of images, including commonly used images, medical images, texture images, aerial images and all of the 1096 images in CorelDraw database. Experimental results and performance comparison with other reversible data hiding schemes are presented to demonstrate the validity of the proposed algorithm.
Formation of interstellar clouds: Parker instability with phase transitions

We numerically follow the nonlinear evolution of the Parker instability in the presence of phase transitions from a warm to a cold H i interstellar medium in two spatial dimensions. The nonlinear evolution of the system favours modes that allow the magnetic field lines to cross the galactic plane. Cold H i clouds form with typical masses ≃105 M⊙, mean densities ≃20 cm−3, mean magnetic-field strengths ≃4.3 μG (rms field strengths ≃6.4 μG), mass-to-flux ratios ≃0.1–0.3 relative to critical, temperatures ≃50 K, (two-dimensional) turbulent velocity dispersions ≃1.6 km s−1 and separations ≃500 pc, in agreement with observations. The maximum density and magnetic-field strength are ≃103 cm−3 and ≃20 μG, respectively. Approximately 60 per cent of all H i mass is in the warm neutral medium. The cold neutral medium is arranged into sheet-like structures both perpendicular and parallel to the galactic plane, but it is also found almost everywhere in the galactic plane, with the density being highest in valleys of the magnetic field lines. ‘Cloudlets’ also form whose physical properties are in quantitative agreement with those observed for such objects by Heiles. The nonlinear phase of the evolution takes ≲30 Myr, so that, if the instability is triggered by a nonlinear perturbation such as a spiral density shock wave, interstellar clouds can form within a time suggested by observations.
Interference Alignment for Line-of-Sight Channels

The fully connected K-user interference channel is studied in a multipath environment with bandwidth W. We show that when each link consists of D physical paths, the total spectral efficiency can grow linearly with K . This result holds not merely in the limit of large transmit power P, but for any fixed P , and is, therefore, a stronger characterization than degrees of freedom. It is achieved via a form of interference alignment in the time domain. A caveat of this result is that W must grow with K, a phenomenon we refer to as bandwidth scaling. Our insight comes from examining channels with single path links (D=1), which we refer to as line-of-sight (LOS) links. For such channels, we build a time-indexed interference graph and associate the communication problem with finding its maximum independent set. This graph has a stationarity property that we exploit to solve the problem efficiently via dynamic programming. Additionally, the interference graph enables us to demonstrate the necessity of bandwidth scaling for any scheme operating over LOS interference channels. Bandwidth scaling is then shown to also be a necessary ingredient for interference alignment in the K-user interference channel.
Alignment-free local structural search by writhe decomposition

Motivation: Rapid methods for protein structure search enable biological discoveries based on flexibly defined structural similarity, unleashing the power of the ever greater number of solved protein structures. Projection methods show promise for the development of fast structural database search solutions. Projection methods map a structure to a point in a high-dimensional space and compare two structures by measuring distance between their projected points. These methods offer a tremendous increase in speed over residue-level structural alignment methods. However, current projection methods are not practical, partly because they are unable to identify local similarities. Results: We propose a new projection-based approach that can rapidly detect global as well as local structural similarities. Local structural search is enabled by a topology-inspired writhe decomposition protocol that produces a small number of fragments while ensuring that similar structures are cut in a similar manner. In benchmark tests, we show that our method, writher, improves accuracy over existing projection methods in terms of recognizing scop domains out of multi-domain proteins, while maintaining accuracy comparable with existing projection methods in a standard single-domain benchmark test. Availability: The source code is available at the following website: http://compbio.berkeley.edu/proj/writher/ Contact: dzhi@compbio.berkeley.edu Supplementary information:Supplementary data are available at Bioinformatics online.
HEDGING WITH FUTURES AND OPTIONS: A DEMAND SYSTEMS APPROACH

The optimal hedging portfolio is shown to include both futures and options under a variety of circumstances when the marginal cost of hedging is non-zero. Futures and options are treated as substitute goods, and properties of the resulting hedging demand system are explained. The overall optimal hedge ratio is shown to increase when the marginal cost of trading options is reduced. The overall optimal hedge ratio is shown to decrease when the marginal cost of trading futures is decreased. The implication is that hedging demand can be stimulated by reducing the perceived cost of trading options, by educating hedgers about options and by initiating programs like the Dairy Options Pilot Program. The demand systems approach is applied to estimate optimal hedge ratios for dairy producers hedging corn inputs in five regions of Pennsylvania.
Crowdsourced Bayesian auctions

We investigate the problem of optimal mechanism design, where an auctioneer wants to sell a set of goods to buyers, in order to maximize revenue. In a Bayesian setting the buyers' valuations for the goods are drawn from a prior distribution D, which is often assumed to be known by the seller. In this work, we focus on cases where the seller has no knowledge at all, and "the buyers know each other better than the seller knows them". In our model, D is not necessarily common knowledge. Instead, each buyer individually knows a posterior distribution associated with D. Since the seller relies on the buyers' knowledge to help him set a price, we call these types of auctions crowdsourced Bayesian auctions.For this crowdsourced Bayesian model and many environments of interest, we show that, for arbitrary valuation distributions D (in particular, correlated ones), it is possible to design mechanisms matching to a significant extent the performance of the optimal dominant-strategy-truthful mechanisms where the seller knows D.To obtain our results, we use two techniques: (1) proper scoring rules to elicit information from the players; and (2) a reverse version of the classical Bulow-Klemperer inequality. The first lets us build mechanisms with a unique equilibrium and good revenue guarantees, even when the players' second and higher-order beliefs about each other are wrong. The second allows us to upper bound the revenue of an optimal mechanism with n players by an n/n--1 fraction of the revenue of the optimal mechanism with n -- 1 players. We believe that both techniques are new to Bayesian optimal auctions and of independent interest for future work.
Accuracy of Discrete-Velocity BGK Models for the Simulation of the Incompressible Navier-Stokes Equations

Abstract The lattice Boltzmann (LB) method has been used as a Navier-Stokes CFD method since its introduction in 1988. The LB method is a Lagrangian discretization of a discrete-velocity Boltzmann equation. We introduce an alternative, fourth-order discretization scheme and compare results with those of the LB discretization and with finite-difference schemes applied to the incompressible Navier-Stokes equations in primitive-variable form. A Chapman-Enskog expansion of the PDE system predicts that the macroscopic behavior corresponds to the incompressible Navier-Stokes equations with additional ‘compressibility error’ of order Mach number squared. We numerically demonstrate convergence of the BGK schemes to the incompressible Navier-Stokes equations and quantify the errors associated with compressibility and discretization effects. When compressibility error is smaller than discretization error, convergence in both grid spacing and time step is shown to be second-order for the LB method and is confirmed to be fourth-order for the fourth-order BGK solver. However, when the compressibility error is simultaneously reduced as the grid is refined, the LB method behaves as a first-order scheme in time.
Relative virtual localization and vanishing of tautological classes on moduli spaces of curves

We prove a localization formula for the moduli space of stable relative maps. As an application, we prove that all codimension i tautological classes on the moduli space of stable pointed curves vanish away from strata corresponding to curves with at least i-g+1 genus 0 components. As consequences, we prove and generalize various conjectures and theorems about various moduli spaces of curves (due to Diaz, Faber, Getzler, Ionel, Looijenga, Pandharipande, and others). This theorem appears to be the geometric content behind these results; the rest is straightforward graph combinatorics. The theorem also suggests the importance of the stratification of the moduli space by the number of rational components.
Designing Effective Heterogeneous Teams for Multiagent Routing Domains

Many realistic problem domains are composed of heterogeneous tasks distributed in a physical environment. Even though the distribution of skills among the members of a heterogeneous team has a significant influence on its effectiveness, little is known about how to design effective heterogeneous teams. In this paper, we develop a graph-search approach to tackle this team design problem in the context of multiagent routing, a generalizable domain in which heterogeneous, randomly located tasks must be completed in overall minimum time (or make span) given an a priori distribution of their heterogeneity, a fixed team size, and a limited budget. First, we develop complete and optimal search algorithms. Second, we show that dominance-based pruning significantly increases the size of problems that can be solved optimally. Third, we introduce an anytime algorithm called TD-BR that uses beam search with restarts in order to scale up to much larger problems. We evaluate our algorithms empirically in two ways: first, we predict the performance of the teams using a team performance metric called task coverage, and show that our algorithms produce high coverage teams, second, we test a subset of these teams in simulation by allocating the teams to various task sets and measuring their make span. We show that our teams perform well when compared to an ideal homogeneous team, and outperform heterogeneous teams created by other methods. Our main contributions are thus new algorithmic tools for designers of heterogeneous teams in robotics and other domains where modular construction and refitting of robots is possible.
SAMUELSON'S FULL DUALITY AND THE USE OF DIRECTED ACYCLICAL GRAPHS

To date, mixed demand systems have been all but ignored in empirical work. A possible reason for the scarcity of such applications is that one needs to know a priori which prices and quantities are...
Micromechanics of Oxidation in Composites with Impermeable Fibers

This paper describes an approach to determine effective oxidation mat erial properties for a unidirectional laminate or tow. The effective properties will ultimately be used to model the oxidation behavior of textile composites. The overall goal of this research effort is to simulate the effect of high temperature oxidation on the damage progression and mechanical behavior of textile composites. This involves running a coupled analysis simulating the oxidation of the composite material over time and a progressive damage analysis that takes into account the effect of the oxida tion on the mechanical properties and conversely, the effect of damage and stresses on the oxidation behavior . It is necessary to use homogenized properties for the tow because it is practically impossible to discretely model all the fibers in a composite. The basic oxidation model is taken from existing work in the literature which was used to simulate the oxidation behavior of neat PMR -15 resin. The governing equations and the finite element formulation for the model are described as well as different app roaches for determining the various effective properties. Two configurations are analyzed to test the accuracy of the effective oxidation properties. The configurations are discretely modeled to provide the reference solution and the different models with fully homogenized materials as well as mixed regions are used to determine the accuracy of the effective properties. The concentration of oxygen in the model as well as the oxidation state of the materials in the composite are compared to the reference mod el. It is seen that the effective oxidation properties perform reasonably well for both configurations and is able to simulate the oxidation layer growth.
Effects of Physical Activity on Preterm Birth

The authors conducted a cohort study of low income women to determine the effect of physical activity on the risk of preterm birth. Women were sampled prenatally from four clinic sites and were scheduled for delivery at the University of Maryland Medical Systems (UMMS). Women who delivered infants at UMMS but who had received no prenatal care were also eligible. Preterm delivery was defined as a delivery prior to 37 completed weeks gestation. After adjusting for confounders, the odds of preterm delivery were increased for women who climbed stairs > or = 10 times per day (odds ratio (OR) = 1.60, 95% confidence interval 1.05-2.46) and for women who engaged in purposive walking > or = 4 days per week (OR = 2.10, 95% CI 1.38-3.20). Leisure-time exercise (> or = 60 days in the first and second trimesters combined) had a protective effect on preterm delivery (OR = 0.51, 95% CI 0.27-0.95). Television viewing had a U-shaped relation with preterm delivery (ORs (95% CI): 42 hours, 3.05 (1.75-5.40)). While the results support current recommendations regarding leisure-time activities, activities of daily living appear to increase risk of preterm delivery among low income women. These findings and those for television watching warrant further investigation.
Optimal wakefield excitation and particle acceleration in a relativistic counterstreaming electron beam

The wake excitation of nonlinear plasma waves in a relativistic counterstreaming electron beam and the consequences for charged particle acceleration are discussed. The basic idea is to use an optimally shaped high-energy electron bunch as a driving source to generate a large-amplitude, high-phase-velocity nonlinear plasma wave in a high-density relativistic counterstreaming electron beam. A trailing charged particle bunch can then be loaded onto the wave and accelerated to a high energy. Discussions of staged acceleration are also included. It is found that the relativistic effects resulting from the relativistic streaming of the counterstreaming electron beam can provide Lorentz effects to reduce the two-stream instability for obtaining a higher transformer ratio, to achieve a longer plasma wavelength for easier beam loading, and to ease the technical difficulty connected with generating a well-shaped driving electron bunch. >
Alignment-to-orientation conversion and nuclear quadrupole resonance

The role of alignment-to-orientation conversion (AOC) in nuclear quadrupole resonance (NQR) is discussed. AOC is shown to be the mechanism responsible for the appearance of macroscopic orientation in a sample originally lacking any global polarization. Parallels are drawn between NQR and AOC in atomic physics.
On the Estimation and Inference of a Panel Cointegration Model with Cross-Sectional Dependence

Most of the existing literature on panel data cointegration assumes cross-sectional independence, an assumption that is difficult to satisfy. This paper studies panel cointegration under cross-sectional dependence, which is characterized by a factor structure. We derive the limiting distribution of a fully modified estimator for the panel cointegrating coefficients. We also propose a continuous-updated fully modified (CUP-FM) estimator. Monte Carlo results show that the CUP-FM estimator has better small sample properties than the two-step FM (2S-FM) and OLS estimators.
Imaging studies of photodamage and self-healing in disperse orange 11 dye-doped PMMA

We report on optical imaging studies of self-healing after laser-induced photodamage in disperse orange 11 dye doped into poly(methyl methacrylate) (PMMA) polymer. In particular, the high spatial-contrast image of the damage track made by a line focus pump laser allows the recovery rates to be measured as a function of burn dose using the relationship between transverse distance and pump intensity profile. The time evolution of the damaged population results in an intensity-independent time constant of τ=490.2±8.5min, in agreement with independent measurements of the time evolution of amplified spontaneous emission. Also observed is a damage threshold above which the material does not fully recover.
Prediction of inhibition of the sodium ion-proton antiporter by benzoylguanidine derivatives from molecular structure.

The use of quantitative structure−activity relationships to predict IC50 values of 113 potential Na+/H+ antiporter inhibitors is reported. Multiple linear regression and computational neural networ...
Summer nudging: Can personalized text messages and peer mentor outreach increase college going among low-income high school graduates?

Abstract Several recent low-cost interventions demonstrate that simplifying information about college and financial aid and helping students access professional assistance can generate substantial improvements in students’ postsecondary outcomes. We build on this growing literature by investigating the impact of two applications of behavioral principles to mitigate summer “melt,” the phenomenon that college-intending high school graduates fail to matriculate in college anywhere in the year following high school. One intervention utilized an automated and personalized text messaging campaign to remind college-intending students of required pre-matriculation tasks and to connect them to counselor-based support. Another employed near-aged peer mentors to provide summer outreach and support. The interventions substantially increased college enrollment among students who had less academic-year access to quality college counseling or information. Both strategies are cost–effective approaches to increase college entry among populations traditionally underrepresented in higher education and, more broadly, highlight the potential for low-cost behavioral nudges and interventions to achieve meaningful improvements in students’ educational outcomes.
Signaling Through Pricing by Service Providers with Social Preferences

In many service markets such as consulting, auto repair, financial planning, and healthcare, the service provider may have more information about the customer's problem than the customer, and different customers may impose different costs on the service provider. In principle, the service provider should ethically care about the customer's welfare, but it is possible that a provider may maximize only its own profit. Moreover, the customer may not know ex ante whether the provider is ethical or purely self-interested. We develop a game-theoretic model to investigate pricing strategies and the market outcome in service markets where the provider has two-dimensional private information about her own type whether ethical or self-interested and about the customer's condition whether serious or minor. We show that in a less ethical market, a self-interested provider will charge different prices based on the customer's condition, whereas an ethical provider will charge the same price for both conditions. In contrast, in a more ethical market, both the self-interested and the ethical provider will charge the same uniform price to both types of customers. Interestingly, both market efficiency and the customer's ex ante expected surplus might be lower in a more ethical market than in a less ethical one.
Reactivity of Iron/Zirconia Powder in Fluidized Bed Thermochemical Hydrogen Production Reactors

A fluidized bed reactor has been developed which uses a two-step thermochemical water splitting process with a peak hydrogen production rate of 47 Ncm 3 /min.gFe at an oxidation
Residential Mobility and the Housing Market in a Two-sector Neoclassical Growth Model

The impact of residential mobility and competitive housing markets on long run growth is examined using a two-sector general equilibrium overlapping-generations model in continuous time. There is an infinity of agents with finite lives who adjust their housing consumption by moving, which is costly. We explore the model’s steady-state properties, first with a free housing market, then under rent control when the market clears through restrictions on the frequency of moves. Rent controls do not just reduce welfare; they may increase the steadystate capital-labor ratio.
Linguistic Structure as Composition and Perturbation

This paper discusses the problem of learning language from unprocessed text and speech signals, concentrating on the problem of learning a lexicon. In particular, it argues for a representation of language in which linguistic parameters like words are built by perturbing a composition of existing parameters. The power of the representation is demonstrated by several examples in text segmentation and compression, acquisition of a lexicon from raw speech, and the acquisition of mappings between text and artificial representations of meaning.
Network-Based Pathway Enrichment Analysis with Incomplete Network Information

Motivation Pathway enrichment analysis has become a key tool for biomedical researchers to gain insight into the underlying biology of differentially expressed genes, proteins and metabolites. It reduces complexity and provides a system-level view of changes in cellular activity in response to treatments and/or in disease states. Methods that use existing pathway network information have been shown to outperform simpler methods that only take into account pathway membership. However, despite significant progress in understanding the association amongst members of biological pathways, and expansion of data bases containing information about interactions of biomolecules, the existing network information may be incomplete or inaccurate and is not cell-type or disease condition-specific. Results We propose a constrained network estimation framework that combines network estimation based on cell- and condition-specific high-dimensional Omics data with interaction information from existing data bases. The resulting pathway topology information is subsequently used to provide a framework for simultaneous testing of differences in expression levels of pathway members, as well as their interactions. We study the asymptotic properties of the proposed network estimator and the test for pathway enrichment, and investigate its small sample performance in simulated and real data settings. Availability and implementation The proposed method has been implemented in the R-package netgsa available on CRAN. Contact jinma@upenn.eduSupplementary information: Supplementary data are available at Bioinformatics online.
Large deviations in the reinforced random walk model on trees

In this paper, we consider the linearly reinforced and the once-reinforced random walk models in the transient phase on trees. We show the large deviations for the upper tails for both models. We also show the exponential decay for the lower tail in the once-reinforced random walk model. However, the lower tail is in polynomial decay for the linearly reinforced random walk model.
The impact of multi‐group multi‐layer network structure on the performance of distributed consensus building strategies

Multi-group multi-layer (MGML) structure is common to distributed sensor networks (DSNs) in many natural and engineered applications. Although network structure plays a crucial role in the performance of consensus building strategies in such networks, little work is done to establish the precise connection between the two. In this paper, we consider a structural approach to the consensus building problem in MGML DSNs that have wide applications in e.g., multi-vehicle systems. From among the possible network structures, we focus on bipartite graph structures and briey discuss hierarchical structures due to their wide applicability in similar applications. We show that the consensus building dynamics in MGML structure can be easily mapped to canonical discrete-time rst-order dynamics. We establish the exact conditions for consensus and derive a precise relationship between the consensus value and the degree distribution of the nodes in the bipartite graph. We also demonstrate that for subclasses of connectivity patterns, convergence time and simple characteristics of network topology can be captured by explicit algebra. Direct inference of the convergence behavior of consensus strategies from MGML DSN structure is the main contribution of this paper. The insights gained from our analysis facilitate the design and development of large-scale DSNs that meet specic performance criteria.
Why do countries participate in international large-scale assessments ? The Case of PISA

The number of countries that regularly participate in international large-scale assessments has increased sharply over the past 15 years, with the share of countries participating in the Programme for International Student Assessment growing from one-fifth of countries in 2000 to over one-third of countries in 2015. What accounts for this increase? This paper explores the evidence for three broad explanations: globalization of assessments, increasing technical capacity for conducting assessments, and increased demand for the microeconomic and macroeconomic data from these assessments. Data were compiled from more than 200 countries for this analysis, for six time periods between 2000 and 2015, yielding more than 1,200 observations. The data cover each country’s participation in each of six cycles of PISA as it relates to the country’s level of economic development, region, prior experience with assessment, and OECD membership. The results indicate that the odds of participation in PISA are markedly higher for OECD member countries, countries in the Europe and Central Asia region, high- and upper-middle-income countries, and countries with previous national and international assessment experience; the paper also finds that regional assessment experience is unrelated to PISA participation.
History-based route selection for reactive ad hoc routing protocols

Ad hoc networks rely on cooperation in order to operate, but in a resource constrained environment not all nodes behave altruistically. Selfish nodes preserve their own resources and do not forward packets not in their own self interest. These nodes degrade the performance of the network, but judicious route selection can help maintain performance despite this behavior. Many route selection algorithms place importance on shortness of the route rather than its reliability. We introduce a light-weight route selection algorithm that uses past behavior to judge the quality of a route rather than solely on the length of the route. It draws information from the underlying routing layer at no extra cost and selects routes with a simple algorithm. This technique maintains this data in a small table, which does not place a high cost on memory. History-based route selection's minimalism suits the needs the portable wireless devices and is easy to implement. We implemented our algorithm and tested it in the ns2 environment. Our simulation results show that history-based route selection achieves higher packet delivery and improved stability than its length-based counterpart.
SLiM: Simulating Evolution with Selection and Linkage

SLiM is an efficient forward population genetic simulation designed for studying the effects of linkage and selection on a chromosome-wide scale. The program can incorporate complex scenarios of demography and population substructure, various models for selection and dominance of new mutations, arbitrary gene structure, and user-defined recombination maps.
The First Case of Successful Transcatheter Aortic Valve Implantation Using CoreValve in Korea

Surgical replacement of the aortic valve is the standard therapy for severe aortic valve stenosis. However, it is generally associated with increased mortality and morbidities in older individuals. Transcatheter aortic valve implantation (TAVI) is a less invasive procedure and has shown similar clinical outcomes as surgical treatment in elderly patients at high risk for conventional surgery. In this report, we describe the first case of TAVI using a CoreValve in Korea. An 84-year-old man with symptomatic severe aortic valve stenosis was successfully treated by transfemoral TAVI. The patient was discharged without any significant complications and remained free of adverse clinical event for a follow-up duration of 6 months.
Testing of DiffServ performance over a U.S. Navy satellite communication network

The U.S. Navy's automated digital network system (ADNS) serves as the primary means of ship-to-shore and ship-to-ship WAN connectivity. A major limitation of current ADNS networks is their inability to provide prioritized service for mission-critical traffic and end-to-end quality of service over high-delay, low-bandwidth satellite links. Accordingly, an upgrade strategy has been developed to provision ADNS with differentiated services (DiffServ) and priority queuing. Weighted random early detection (WRED) is a key congestion avoidance mechanism within the ADNS DiffServ model. This paper describes the results of ADNS QoS testing of the proposed WRED configuration to ascertain its performance relative to best-effort networks. An alternate WRED configuration is proposed to further enhance network performance. Test results suggest that use of the alternate WRED settings will improve throughput and maintain low packet loss rates for high-priority traffic.
Monopoles and lens space surgeries

Monopole Floer homology is used to prove that real projective three-space cannot be obtained from Dehn surgery on a nontrivial knot in the three-sphere. To obtain this result, we use a surgery long exact sequence for monopole Floer homology, together with a nonvanishing theorem, which shows that monopole Floer homology detects the unknot. In addition, we apply these techniques to give information about knots which admit lens space surgeries, and to exhibit families of three-manifolds which do not admit taut foliations.
A Large Intergenic Noncoding RNA Induced by p53 Mediates Global Gene Repression in the p53 Response

Recently, more than 1000 large intergenic noncoding RNAs (lincRNAs) have been reported. These RNAs are evolutionarily conserved in mammalian genomes and thus presumably function in diverse biological processes. Here, we report the identification of lincRNAs that are regulated by p53. One of these lincRNAs (lincRNA-p21) serves as a repressor in p53-dependent transcriptional responses. Inhibition of lincRNA-p21 affects the expression of hundreds of gene targets enriched for genes normally repressed by p53. The observed transcriptional repression by lincRNA-p21 is mediated through the physical association with hnRNP-K. This interaction is required for proper genomic localization of hnRNP-K at repressed genes and regulation of p53 mediates apoptosis. We propose a model whereby transcription factors activate lincRNAs that serve as key repressors by physically associating with repressive complexes and modulate their localization to sets of previously active genes.
Integrating an MR head into a peak detection channel

Integrating an MR head into a peak detection channel requires the engineer to deal with basic differences between MR and thin film heads. These differences result from nonlinear sensor response, separate write and read elements, and having an active element at the ABS. A simple model for flux superposition can adequately address nonlinear effects and be used for equalization design. Timing budgets can be developed which demonstrate the dominance of media noise for present day systems. Single threshold qualification can handle most current system requirements, Separate read/write elements mean that more attention needs to be paid to offtrack equalization design and head dimensional tolerancing. An active element at the ABS requires better control of the head-disc potential and leakage currents. >
X-Ray Spectroscopy Of The Radiation-Driven Winds Of Massive Stars: Line Profile And Line Ratio Diagnostics

Massive stars drive powerful, supersonic winds via the radiative momentum associated with the thermal UV emission from their photospheres. Shock phenomena are ubiquitous in these winds, heating them to millions, and sometimes tens of millions, of degrees. The emission line spectra from the shock‐heated plasma provide powerful diagnostics of the winds’ physical conditions, which in turn provide constraints on models of wind shock heating. Here I show how x‐ray line transfer is affected by photoelectric absorption in the partially ionized component of the wind and how it can be modeled to determine the astrophysically important mass‐loss rates of these stellar winds. I also discuss how photoexcitation out of metastable excited levels of helium‐like ions can provide critical information about the location of the hot plasma in magnetically channeled massive star winds.
Quantitative Characterization of Steady-State Ankle Impedance With Muscle Activation

Characterization of multi-variable ankle mechanical impedance is crucial to understanding how the ankle supports lower-extremity function during interaction with the environment. This paper reports quantification of steady-state ankle impedance when muscles were active. Vector field approximation of repetitive measurements of the torque-angle relation in two degrees of freedom (inversion/eversion and dorsiflexion/plantarflexion) enabled assessment of spring-like and non-spring-like components. Experimental results of eight human subjects showed direction-dependent ankle impedance with greater magnitude than when muscles were relaxed. In addition, vector field analysis demonstrated a non-spring-like behavior when muscles were active, although this phenomenon was subtle in the unimpaired young subjects we studied.
Nonlinear Tracking Control for Satellite Formations

A tracking control law using a sliding mode framework is derived to control a satellite formation. Hill's relative motion equations are used to model the follower satellite's motion relative to the leader. To minimize fuel required to maintain the formation, each satellite is constrained to reside near a natural orbit. Control forces are applied only to maintain the desired relative motion by correcting for initial offsets and perturbation effects that tend to disperse the formation. The control law is modified to account for the discontinuous nature of the control forces available with the satellite propulsive thrusters. Numerical simulations using a high-fidelity, nonlinear model demonstrate the control law performance for the full nonlinear dynamics with high order perturbations.
Building theories from case study research.

�Traditional, hierarchical views of leadership are less and less useful given the complexities of our modern world. Leadership theory must transition to new perspectives that account for the complex adaptive needs of organizations. In this paper, we propose that leadership (as opposed to leaders) can be seen as a complex dynamic process that emerges in the interactive “spaces between” people and ideas. That is, leadership is a dynamic that transcends the capabilities of individuals alone; it is the product of interaction, tension, and exchange rules governing changes in perceptions and understanding. We label this a dynamic of adaptive leadership, and we show how this dynamic provides important insights about the nature of leadership and its outcomes in organizational fields. We define a leadership event as a perceived segment of action whose meaning is created by the interactions of actors involved in producing it, and we present a set of innovative methods for capturing and analyzing these contextually driven processes. We provide theoretical and practical implications of these ideas for organizational behavior and organization and management theory.
A Unified Approach to IRT Scale Linking and Scale Transformations

Abstract. This paper examines IRT scale transformations and IRT scale-linking methods used in the nonequivalent groups with anchor test (NEAT) design to equate two tests, X and Y. It proposes a unifying approach to the commonly used IRT linking methods: mean-mean, mean-var linking, concurrent calibration, Stocking and Lord, and Haebara characteristic curves approaches, and fixed-item parameters scale linkage. The main idea is to view any linking procedure as a restriction on the item parameter space. Then, a rewriting of the log-likelihood function together with an appropriately implemented maximization procedure of the log-likelihood function under linear (or nonlinear) restrictions will accomplish the linking. The proposed method is general enough to cover both the dichotomous item response models (the one parameter logistic (1PL) model, 2PL, and 3PL) and the polytomous unidimensional IRT models such as the generalized partial credit model.
Cycle lengths in sparse graphs

Let C(G) denote the set of lengths of cycles in a graph G. In the first part of this paper, we study the minimum possible value of |C(G)| over all graphs G of average degree d and girth g. Erdős [8] conjectured that |C(G)|=Ω ` d (g−1)/2 for all such graphs, and we prove this conjecture. In particular, the longest cycle in a graph of average degree d and girth g has length Ω ` d (g−1)/2 . The study of this problem was initiated by Ore in 1967 and our result improves all previously known lower bounds on the length of the longest cycle [7,11,21,24,25]. Moreover, our bound cannot be improved in general, since known constructions of d-regular Moore Graphs of girth g have roughly that many vertices. We also show that Ω ` d (g−1)/2 is a lower bound for the number of odd cycle lengths in a graph of chromatic number d and girth g. Further results are obtained for the number of cycle lengths in H-free graphs of average degree d.
Do prediction markets aid defenders in a weak-link contest?

Abstract Laboratory experiments have demonstrated that prediction market prices weakly aggregate the disparate information of the traders about states (moves) of nature. However, in many practical applications one is attempting to predict the move of a strategic rival. This is particularly important in aggressor–defender contests. This paper reports an experiment where the defender may have the advantage of observing a prediction market on the aggressor's action. The results of the experiments indicate that: the use of prediction markets does not increase the defender's win rate; prediction markets contain reliable information regarding aggressors’ decisions that is not being exploited by defenders; and the existence of a prediction market does not alter the behavior of the aggressor whose behavior is being forecast.
The impact of living wage laws on urban economic development patterns and the local business climate: Evidence from california cities

Traditional local economic development policies entice private businesses to create highpaying jobs in a given jurisdiction through direct subsidies or by projecting a positive “business climate” within regional and global arenas. Since 1994 however, “living wage” ordinances have emerged as an alternative response to labor market polarization in urban areas. However, these laws raise labor costs for employers and thus have the potential to reduce economic growth. I assess the impact of living wage laws on employment and establishment levels in the cities that pass them. I provide separate estimates for government contractors and other firms that may be indirectly signaled by a change in the local political environment. I use the National Establishment Time-series database to construct a panel dataset that tracks employment and establishment levels for all California jurisdictions. I produce difference-in-difference estimates that indicate that living wage laws have no significant impact on employment or establishment growth. Additionally, I find no evidence that the passage of living wage laws sends a negative “signal” to businesses about a potentially harmful local business climate.
Multi-return function call

It is possible to extend the basic notion of “function call” to allow functions to have multiple return points. This turns out to be a surprisingly useful mechanism. This article conducts a fairly wide-ranging tour of such a feature: a formal semantics for a minimal $\lambda$-calculus capturing the mechanism; motivating examples; monomorphic and parametrically polymorphic static type systems; useful transformations; implementation concerns and experience with an implementation; and comparison to related mechanisms, such as exceptions, sum-types and explicit continuations. We conclude that multiple-return function call is not only a useful and expressive mechanism, at both the source-code and intermediate-representation levels, but also quite inexpensive to implement.
Waves in Bars of Mechanically Unstable Materials

Waves in bars of mechanically unstable materials, discussing differential equation of motion, jump conditions, wave velocity and application to annealed aluminum
On certain families of elliptic curves in projective space

Let El(n; p1, . . . , pm) be the family of elliptic curves of degree n + 1 in Pn containing a fixed set of m distinct points p1, . . . , pm . In modern language, El(n; p1, . . . , pm) is a Zariski-open subset of the fibre of the evaluation map ev : M1,m(P, n + 1) → (Pn)m , where M1,m(P, n + 1) is the space of regular maps of elliptic curves equipped with an ordered set of m points to a curve of degree n + 1 in Pn . Its general fibre, if not empty, is an irreducible variety of dimension (n + 1)2 − m(n − 1). The largest possible m for which the map ev is dominant is equal to 9(n = 2, 5), 8(n = 3, 4), n + 3(n ≥ 6). In the last case we show that the general fibre is isomorphic to an open subset of a complete intersection of n − 2 diagonal quadrics in Pn+2. In particular, birationally, it is a Fano variety if n ≤ 6, a Calabi–Yau if n = 7, and of general type if n ≥ 8. The group Gn = (Z/2Z)n+2 acts naturally in Pn+2 by multiplying the projective coordinates with ±1. The corresponding action of a subgroup of index 2 of Gn is induced by a certain group of Cremona transformations in Pn which we will describe explicitly. There are three cases when El(n; p1, . . . , pm) is of expected dimension 0. They are (n,m) = (2, 9), (3, 8), (5, 9). It is well known that in the first two cases El(n; p1, . . . , pm) consists of one point. Less known is the fact that the same is true in the case (5, 9). D. Babbage [1] attributes this result to T. G. Room. Apparently it was proven much earlier by A. Coble [2]. We reproduce Coble’s proof in the paper. This result implies the existence of a rational elliptic fibration f : P5− → El(5, p1, . . . , p8) which is an analog of the well-known rational elliptic fibrations
A simple diode model with reverse recovery

The basic diode charge-control model used in SPICE is extended to include reverse recovery. The model is derived from the semiconductor charge transport equations. The diode charge transport equations are simplified using the lumped charged concept of Linvill, and the model is demonstrated on the Saber simulator for simple inductive and resistive load circuits. The two model parameters, diode lifetime and diffusion transit time, can easily be determined from a switching waveform. >