bluuebunny/crossref_metadata_2025_split huggingface dataset:
The perils with the misuse of predictive power
Authors: Dallow Nigel , Fina Paolo 
Published: October 2010

AbstractIn early drug development, especially when studying new mechanisms of action or in new disease areas, little is known about the targeted or anticipated treatment effect or variability estimates. Adaptive designs that allow for early stopping but also use interim data to adapt the sample size have been proposed as a practical way of dealing with these uncertainties. Predictive power and conditional power are two commonly mentioned techniques that allow predictions of what will happen at the end of the trial based on the interim data. Decisions about stopping or continuing the trial can then be based on these predictions. However, unless the user of these statistics has a deep understanding of their characteristics important pitfalls may be encountered, especially with the use of predictive power. The aim of this paper is to highlight these potential pitfalls. It is critical that statisticians understand the fundamental differences between predictive power and conditional power as they can have dramatic effects on decision making at the interim stage, especially if used to re‐evaluate the sample size. The use of predictive power can lead to much larger sample sizes than either conditional power or standard sample size calculations. One crucial difference is that predictive power takes account of all uncertainty, parts of which are ignored by standard sample size calculations and conditional power. By comparing the characteristics of each of these statistics we highlight important characteristics of predictive power that experimenters need to be aware of when using this approach. Copyright © 2010 John Wiley & Sons, Ltd.
Ramsey games with giants
Authors: Bohman Tom , Frieze Alan , Krivelevich Michael , Loh Po‐Shen , Sudakov Benny 
Published: October 2010

AbstractThe classical result in the theory of random graphs, proved by Erdős and Rényi in 1960, concerns the threshold for the appearance of the giant component in the random graph process. We consider a variant of this problem, with a Ramsey flavor. Now, each random edge that arrives in a sequence of rounds must be colored with one of r colors. The goal can be either to create a giant component in every color class, or alternatively, to avoid it in every color. One can analyze the offline or online setting for this problem. In this paper, we consider all these variants and provide nontrivial upper and lower bounds; in certain cases (like online avoidance) the obtained bounds are asymptotically tight. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2011
How small system dynamics models can help the public policy process
Authors: Ghaffarzadegan Navid , Lyneis John , Richardson George P. 
Published: October 2010

AbstractPublic policies often fail to achieve their intended result because of the complexity of both the environment and the policy‐making process. In this article, we review the benefits of using small system dynamics models to address public policy questions. First we discuss the main difficulties inherent in the public policy‐making process. Then, we discuss how small system dynamics models can address policy‐making difficulties by examining two promising examples: the first in the domain of urban planning and the second in the domain of social welfare. These examples show how small models can yield accessible, insightful lessons for policy making stemming from the endogenous and aggregate perspective of system dynamics modeling and simulation. Copyright © 2010 System Dynamics Society.
Nanoparticles as magnetic resonance imaging contrast agents for vascular and cardiac diseases
Authors: Chen Wei , Cormode David P. , Fayad Zahi A. , Mulder Willem J. M. 
Published: October 2010

AbstractAdvances in nanoparticle contrast agents for molecular imaging have made magnetic resonance imaging a promising modality for noninvasive visualization and assessment of vascular and cardiac disease processes. This review provides a description of the various nanoparticles exploited for imaging cardiovascular targets. Nanoparticle probes detecting inflammation, apoptosis, extracellular matrix, and angiogenesis may provide tools for assessing the risk of progressive vascular dysfunction and heart failure. The utility of nanoparticles as multimodal probes and/or theranostic agents has also been investigated. Although clinical application of these nanoparticles is largely unexplored, the potential for enhancing disease diagnosis and treatment is considerable. WIREs Nanomed Nanobiotechnol 2011 3 146–161 DOI: 10.1002/wnan.114This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease
Ultra-parabolic H-measures and compensated compactness
Authors: Panov E.Yu. 
Published: October 2010

We present a generalization of compensated compactness theory to the case of variable and generally discontinuous coefficients, both in the quadratic form and in the linear, up to the second order, constraints. The main tool is the localization properties for ultra-parabolic
H
-measures corresponding to weakly convergent sequences.

Résumé

Nous présentons ici une généralisation de la théorie de la « compacité par compensation ». Le cas d'une forme quadratique et de contraintes différentielles avec coefficients variables, éventuellement discontinus en espace, est considéré. Ces contraintes différentielles peuvent être d'ordre un, mais aussi d'ordre deux. Notre outil principal est le principe de localisation pour les
H
-mesures ultra-paraboliques associées à des suites de fonctions faiblement convergentes.
Childhood onset schizophrenia: support for a progressive neurodevelopmental disorder
Authors: Rapoport Judith L. , Gogtay Nitin 
Published: October 2010

AbstractStructural brain abnormalities have become an established feature of schizophrenia and increasing evidence points towards the progressive nature of these abnormalities. The brain abnormalities are most profound in early onset cases, which have a severe, treatment refractory phenotype and more salient genetic features. Unique insights could thus be gained in schizophrenia pathology from studying the earliest manifestations of the illness. This paper reviews and updates the findings on anatomic brain development in patients with very early onset schizophrenia while showing preliminary data from ongoing studies. Collectively, our studies demonstrate that childhood‐onset schizophrenia (COS) subjects show progressive loss of gray matter, delayed/disrupted white matter (WM) growth, and a progressive decline in cerebellar volume, some of which are shared by their healthy siblings. The developmental patterns or the ‘trajectories’ of brain development are often more striking than anatomic brain differences at any one point in time; highlighting the importance of longitudinal studies. The sibling findings of partially shared gray matter (GM) deficits which appear to normalize with age, along with other genetic analyses, provide evidence that the brain developmental ‘patterns/trajectories’ for several regions at particular ages could be useful endophenotypes (trait markers).
Behind the Curtain with the Noble Savage: Stage Management of Indian Plays, 1825–1860
Authors: Amacher Richard E. 
Published: October 2010

If, as Professor Quinn maintains, the national dramas centering about the American Revolution held the spotlight in the United States during the period from 1825 to 1860, certainly the Indian plays featuring the noble savage rivaled them as the second most popular form of stage entertainment. Relatively little is known of the early productions of these Indian plays by American authors.One of the earliest American productions took the form of an “operatic spectacle,” called Tammany. It was put on at the John Street Theater in New York on March 3, 1794, with a Mrs. Hatton in the lead, and is often credited as originating “that impossible type of stage Indian” which never existed in real life.
The Queen's Men, 1583–1592
Authors: Pinciss G. M. 
Published: October 2010

The Master of the Revels, Edmund Tilney, entered a traveling charge of one pound in the Revels Accounts when he was called to court “to choose out a companie of players for her majestie. Stow recorded this event in his Abridgement of the English Chronicle:This yeare 1583, the Queene being at Barne Elmes, at the earnest suite of sir Francis Walsingham, shee entertained twelve Players into her service, and allowed them wages and liveries as Groomes of the Chamber, and untill then she had none of her owne, but divers Lords had Players.
A Judaeo-Arabic Fragment of Ibn-Biklārish'sKitāb al-Mustaʿīnī, Part of a Unique 12th-Century Tabular Medical Book Found in the Cairo Genizah (T-S Ar.44.218)
Authors: SERRI YARON , LEV EFRAIM 
Published: October 2010

AbstractThe reconstruction of the library of Eastern medieval Jewish scholars and medical practitioners according to the Cairo Genizah is a long-term project. In the course of the work a Judaeo-Arabic fragment of a unique tabular medical book by Ibn Biklārish (T-S Ar.44.218) was identified by the authors of this article.The fragment is unique in several respects, particularly (a) very few medieval Arabic tabular medical works are known, (b) only few works by Andalusian Jewish authors of the late 11th or early 12th century have been found in the Genizah so far, (c) only one Judaeo-Arabic fragment of Ibn Biklārish'sKitāb al-Mustaʿīnīis known to date.The main importance of our find is that it is the first time that a rare Spanish medical book has appeared in the Cairo Genizah collection. Dozens of the Genizah's fragments have been identified as medical books, but none by a Spanish Jewish author, written in Judaeo-Arabic, and tabulated!
Non-equilibrium Dynamical Processes in the Galaxy
Authors: Quillen Alice. C , Minchev Ivan 
Published: October 2010

AbstractDynamical models have often necessarily assumed that the Galaxy is nearly steady state or dynamically relaxed. However observed structure in the stellar metallicity, spatial and velocity distributions imply that heating, mixing and radial migration has taken place. Better comprehension of non-equilibrium processes will allow us to not only better understand the current structure of the galaxy but its past evolution.
The Milky Way Halo and the First Stars: New Frontiers in Galactic Archaeology
Authors: Beers Timothy C. , Tumlinson Jason , O'Shea Brian , Peruta Carolyn , Carollo Daniela 
Published: October 2010

AbstractWe discuss plans for a new joint effort between observers and theorists to understand the formation of the Milky Way halo back to the first epochs of chemical evolution. New models based on high-resolution N-body simulations coupled to simple models of Galactic chemical evolution show that surviving stars from the epoch of the first galaxies remain in the Milky Way today and should bear the nucleosynthetic imprint of the first stars. We investigate the key physical influences on the formation of stars in the first galaxies and how they appear today, including the relationship between cosmic reionization and surviving Milky Way stars. These models also provide a physically motivated picture of the formation of the Milky Ways “outer halo,” which has been identified from recent large samples of stars from SDSS. The next steps are to use these models to guide rigorous gas simulations of Milky Way formation, including its disk, and to gradually build up the fully detailed theoretical “Virtual Galaxy” that is demanded by the coming generation of massive Galactic stellar surveys.
Physics and Structure of the Galactic disc(s)
Authors: Schönrich Ralph A. 
Published: October 2010

AbstractThe model of Schönrich & Binney (2009) offers new ways to understand the chemo-kinematic structure of the solar neighbourhood in the light of radial mixing. The combination of chemical information with rich kinematic data reveals a still hardly explored abundance of interconnections and structures from which we can learn about both the physics and history of our Galaxy. Large upcoming datasets can be used to improve estimates of central parameters, to shed light on the Galaxy's history and to explore the unexpected way of understanding the well-known division of the Galactic disc yielded by the new model.
Gas flows within the Galaxy
Authors: Combes Francoise 
Published: October 2010

AbstractIn the recent years, more and more sophisticated models have been proposed for the gas distribution and kinematics in the Milky Way, taking into account the main bar, but also the possible nuclear bar, with the same or different pattern-speed. I review the success and problems encountered by the models, in particular in view of the new discovery of a symmetrical far-side counterpart of the 3 kpc arm. The inner part, dominated by the bar, and the outer parts, dominated by the spiral arms, can be observed from a virtual solar position, and the errors coming from kinematical distances are evaluated. The appearance of four arms could be due to a deprojection bias.
Mapping the Milky Way with SDSS, Gaia and LSST
Authors: Ivezić Željko ,   (for the LSST Collaboration)
Published: October 2010

AbstractWe summarize recent work on the Milky Way “tomography” with SDSS and use these results to illustrate what further breakthroughs can be expect from Gaia and the Large Synoptic Survey Telescope (LSST). LSST is the most ambitious ground-based survey currently planned in the visible band. Mapping of the Milky Way is one of the four main science and design drivers. The main 20 000 deg2. survey area will be imaged about 1000 times in six bands (ugrizy) during the anticipated 10 years of operations, with the first light expected in 2015. Due to Gaia's superb astrometric and photometric accuracy, and LSST's significantly deeper data, the two surveys are highly complementary: Gaia will map the Milky Way's disk with unprecedented detail, and LSST will extend this map all the way to the halo's edge.
Stability of pulsar rotational and orbital periods
Authors: Kopeikin Sergei 
Published: October 2010

AbstractMillisecond and binary pulsars are the most stable astronomical standards of frequency. They can be applied to solving a number of problems in astronomy and time-keeping metrology including the search for a stochastic gravitational wave background in the early universe, testing general relativity, and establishing a new time-scale. The full exploration of pulsar properties requires that proper unbiased estimates of spin and orbital parameters of the pulsar be obtained. These estimates depend essentially on the random noise components present in pulsar timing residuals. The instrumental white noise has predictable statistical properties and makes no harm for interpretation of timing observations, while the astrophysical/geophyeical low-frequency noise corrupts them, thus, reducing the quality of tests of general relativity and decreasing the stability of the pulsar time scale.
Primeval Jets from Young Stars
Authors: Ray T. P. 
Published: October 2010

AbstractThe jet phenomenon lasts at least a million years for young, solar-like, stars and it occurs during a wide variety of young stellar object (YSO) phases. This includes the period when the source is highly embedded (Class 0) to when it becomes optically visible for the first time as a classical T Tauri star (Class II). Here I briefly discuss some of the properties of jets from the youngest objects.
On the correlation of the highest energy cosmic rays with AGNs
Authors: de Souza Vitor , s Biermman Peter L. 
Published: October 2010

AbstractIn this paper we briefly discuss the present status of the cosmic ray astrophysics under the light of the new data from the Pierre Auger Observatory. The measured energy spectrum is used to test the scenario of production in nearby radio galaxies. Within this framework the AGN correlation would require that most of the cosmic rays are heavy nuclei and are widely scattered by intergalactic magnetic fields.
Hot ISM in young elliptical galaxies
Authors: Kim Dong-Woo 
Published: October 2010

AbstractUsing Chandra and XMM-Newton X-ray observations of young, post-merger elliptical galaxies, we present X-ray characteristics of age-related observational results, by comparing with typical old elliptical galaxies in terms of X-ray properties of their low-mass X-ray binaries (LMXBs) and hot interstellar matter (ISM).
Keck constraints on a varying fine-structure constant: wavelength calibration errors
Authors: Murphy Michael T. , Webb John K. , Flambaum Victor V. 
Published: October 2010

AbstractThe Keck telescope's High Resolution Spectrograph (HIRES) has previously provided evidence for a smaller fine-structure constant, α, compared to the current laboratory value, in a sample of 143 quasar absorption systems: Δα/α=(-0.57±0.11)×10−5. The analysis was based on a variety of metal-ion transitions which, if α varies, experience different relative velocity shifts. This result is yet to be robustly contradicted, or confirmed, by measurements on other telescopes and spectrographs; it remains crucial to do so. It is also important to consider new possible instrumental systematic effects which may explain the Keck/HIRES results. Griest et al. (2009) recently identified distortions in the echelle order wavelength scales of HIRES with typical amplitudes ±250 m s−1. Here we investigate the effect such distortions may have had on the Keck/HIRES varying α results. Using a simple model of these intra-order distortions, we demonstrate that they cause a random effect on Δα/α from absorber to absorber because the systems are at different redshifts, placing the relevant absorption lines at different positions in different echelle orders. The typical magnitude of the effect on Δα/α is ~0.4×10−5 for individual absorbers which, compared to the median error on Δα/α in the sample, ~1.9×10−5, is relatively small. Consequently, the weighted mean value changes by less than 0.05×10−5 if the corrections we calculate are applied. Unsurprisingly, with corrections this small, we do not find direct evidence that applying them is actually warranted. Nevertheless, we urge caution, particularly for analyses aiming to achieve high precision Δα/α measurements on individual systems or small samples, that a much more detailed understanding of such intra-order distortions and their dependence on observational parameters is important if they are to be avoided or modelled reliably.
GAME – A small mission concept for high-precision astrometric test of General Relativity
Authors: Vecchiato A. , Gai Mario , Donati Paolo , Morbidelli Roberto , Lattanzi Mario G. , Crosta Mariateresa 
Published: October 2010

AbstractGAME (Gamma Astrometric Measurement Experiment) is a concept for a small mission whose main goal is to measure from space the γ parameter of the Parameterized Post-Newtonian formalism, Will (2001)) A satellite, looking as close as possible to the Solar limb, measures the gravitational bending of light in a way similar to that followed by past experiments from the ground during solar eclipses. In the cited formalism, deviations of the γ parameter from unity are interpreted as deviations from the predictions of General Relativity which are foreseen by several competing theories of gravity. In the present theoretical scenario, such deviations are expected to appear in the range between 10−5 and 10−7. The most stringent experimental constraints available up to now are those of the Cassini mission, that gives 1−γ≲10−5 Bertotti et al. (2003), while future space missions are expected to reach the 10−7 level of accuracy. (Vecchiato et al. (2003), Turyshev et al. (2004), Ni (2008))Preliminary simulations have shown that the expected final accuracy of GAME can reach the 10−7 level, or better if the mission profile can be extended to fit a larger budget Vecchiato et al. (2009), Gai et al. (2009). This work, which has recently been extended to better assess the mission performances, has confirmed the previous results and has given indications on how further improve various aspects of the mission profile.Moreover, thanks to its flexible observation strategy, GAME is also able to target other interesting scientific goals in the realm of General Relativity, as well as in those involving observations of selected extrasolar systems in the brown dwarf and planetary regime.
Dynamo action in rotating convection
Authors: Guerrero Gustavo , de Gouveia Dal Pino Elisabete M. 
Published: October 2010

AbstractWe present MHD numerical simulations of a rotating turbulent convection system in a 3D domain (we have used the finite volume, Goudunov type MHD code PLUTO (Mignone et al. 2007)). Rotating convection is the natural scenario for the study of the dynamo action which is able to generate a large scale magnetic field, like the observed in the sun. Though we have neglected in the present approach the Ω effect, due to a large scale shear, our model is appropriate to test the controversial existence of the so called α effect that arises from helical turbulence (e.g. Cattaneo & Hughes 2006, Käpylä et al. 2009). We start with a two-layer piece-wise polytropic region in hydrostatic equilibrium (e.g. Ziegler 2002), considering one stable overshoot layer at the bottom and a convectively unstable layer at the top of the computational domain. We have allowed this hydrodynamic system to evolve up to the steady state, i.e., after about 10 turnover times (τ). Then, we introduced a seed magnetic field and let the system evolve for more ~40 τ. Our preliminary results are summarized below in Figure 2.
Simulating the chemistry and dynamics of molecular clouds
Authors: Glover S. C. O. , Federrath C. , Low M.-M. Mac , Klessen R. S. 
Published: October 2010

AbstractWe have performed high-resolution three-dimensional simulations of turbulent interstellar gas that for the first time self-consistently follow its coupled thermal, chemical and dynamical evolution. Our simulations have allowed us to quantify the formation timescales for the most important molecules found in giant molecular clouds (H2, CO), as well as their spatial distribution within the clouds. Our results are consistent with models in which molecular clouds form quickly, within 1–2 turbulent crossing times, and emphasize the crucial role of density inhomogeneities in determining the chemical structure of the clouds.
Constraining How Star Formation Proceeds: Surveys in the Sub-mm and FIR
Authors: Johnstone Doug 
Published: October 2010

AbstractCoordinated multi-wavelength surveys of molecular clouds are providing strong constraints on the physical conditions within low-mass star-forming regions. In this manner, Perseus and Ophiuchus have been exceptional laboratories for testing the earliest phases of star formation. Highlights of these results are: (1) dense cores form only in high column density regions, (2) dense cores contain only a few percent of the cloud mass, (3) the mass distribution of the dense cores is similar to the IMF, (4) the more massive cores are most likely to contain embedded protostars, and (5) the kinematics of the dense cores and the bulk gas show significant coupling.