bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resource allocation via sum‐rate maximization in the uplink of multi‐cell OFDMA networks
Authors: Tabassum Hina , Dawy Zaher , Alouini Mohamed Slim 
Published: November 2011

ABSTRACTIn this paper, we consider maximizing the sum rate in the uplink of a multi‐cell orthogonal frequency‐division multiple access network. The problem has a non‐convex combinatorial structure and is known to be NP‐hard. Because of the inherent complexity of implementing the optimal solution, firstly, we derive an upper bound (UB) and a lower bound (LB) to the optimal average network throughput. Moreover, we investigate the performance of a near‐optimal single cell resource allocation scheme in the presence of inter‐cell interference, which leads to another easily computable LB. We then develop a centralized sub‐optimal scheme that is composed of a geometric programming‐based power control phase in conjunction with an iterative subcarrier allocation phase. Although the scheme is computationally complex, it provides an effective benchmark for low complexity schemes even without the power control phase. Finally, we propose less complex centralized and distributed schemes that are well suited for practical scenarios. The computational complexity of all schemes is analyzed, and the performance is compared through simulations. Simulation results demonstrate that the proposed low complexity schemes can achieve comparable performance with that of the centralized sub‐optimal scheme in various scenarios. Moreover, comparisons with the UB and LB provide insight on the performance gap between the proposed schemes and the optimal solution. Copyright © 2011 John Wiley & Sons, Ltd.
Bone development in children and adolescents with PKU
Authors: Mendes A. B. , Martins F. F. , Cruz W. M. S. , da Silva L. E. , Abadesso C.B.M. , Boaventura G.T. 
Published: November 2011

AbstractIntroductionIndividuals with phenylketonuria (PKU, OMIM 261600) have shown bone disease from childhood. Factors such as non‐adherence to treatment, nutritional inadequacy, and high phenylalanine levels are associated with bone disease in several studies. This research aimed to describe the impact of dietary factors (consumption of energy, protein, calcium, phosphorus, and phenylalanine), and the control of plasma phenylalanine levels on bone age (BA) and bone mineral density (BMD).MethodologyThirteen patients of both genders, from 8 to 16 years old participated in this study. Control data were collected of phenylalanine levels, food frequency and record, hand and fist X‐rays, and spinal bone densitometry.ResultsIn children group (CG), individuals non‐adherent to diet (NAD) consumed lower amounts of calcium (472 ± 100 mg/day) and energy (1743 ± 486 Kcal); they had higher rates of phenylalanine (564 ± 94 μmol/L) in blood, intake phenylalanine (701 ± 334 mg/g), and higher protein intake from free foods (14 ± 6.67 g/day); bone age (BA) values higher than the chronological age (CA) and less BMD values (−0.7 ± 1.6 SD) also were verified. In adolescent group (AG, N = 8) of NAD, values were lower for energy intake (1379 ± 258 Kcal), calcium (801 ± 152 mg/day), phosphorus (657 ± 102 mg/day), food protein (25 ± 7.6 g/day), and intake phenylalanine (1067 ± 382 mg/day) than recommended. Higher levels of plasma phenylalanine (851 ± 244 μmol/L), bone age greater than chronological age and lower BMD values (−2.4 ± −2.5 SD) were observed.ConclusionThe results suggest effects on BA and on BMD, in both children and adolescent groups. The bone development is expressed differently in children and adolescents. The non‐adherence to the diet verified in both groups and the consequent imbalance in the nutrients intake involved in bone metabolism suggest that these factors influence the failure to thrive in children and reduced bone mineralization in adolescents.
Drugs as instruments from a developmental child and adolescent psychiatric perspective
Authors: Banaschewski Tobias , Blomeyer Dorothea , Buchmann Arlette F. , Poustka Luise , Rothenberger Aribert , Laucht Manfred 
Published: November 2011

AbstractDevelopmental, epidemiological, and neurobiological studies indicate that the adaptive and maladaptive functions, as well as immediate and long-term consequences of drug use, may vary by age. Early initiation seems to be associated with a reduced ability to use drugs purposely in a temporally stable, non-addictive manner. Prevention strategies should consider social environmental factors and aim to delay age at initiation.
Paramedic Electrocardiogram and Rhythm Identification: A Convenient Training Device
Authors: Hale Peggy , Lowe Robert , Seamon Jason P. , Jenkins James J. 
Published: November 2011

AbstractIntroduction:A common reason for utilizing local paramedics and the emergency medical services is for the recognition and immediate treatment of chest pain, a complaint that has multiple possible etiologies. While many of those complaining of disease processes responsible for chest pain are benign, some will be life-threatening and will require immediate identification and treatment. The ability of paramedics to not only perform field electrocardiograms (ECGs), but to accurately diagnose various unstable cardiac rhythms has shown significant reduction in time to specific treatments. Increasing the overall accuracy of ECG interpretation by paramedics has the potential to facilitate early and appropriate treatment and decrease patient morbidity and mortality.Methods:A convenient training device (flip book) on ambulances and in common areas in the fire station could improve field interpretation of certain cardiac rhythms. This training device consists of illustrated sample ECG tracings and their associated diagnostic criteria. The goal was to enhance the recognition and interpretation of ECGs, and thereby, reduce delays in the initiation of treatment and potential complications associated with misinterpretation.This study was a prospective, observational study using a matched pre-test/post-test design. The study period was from November 2008 to December 2008. A total of 136 paramedics were approached to participate in this study. A pre-test consisting of 15 12-lead ECGs was given to all paramedics who agreed to participate in the study. Once the pre-tests were completed, the flip books were placed in common areas. Approximately one month after the flip books were made available to the paramedics, a post-test was administered.Statistical comparisons were made between the pre- and post-test scores for both the global test and each type of rhythm.Results:Using these data, there were no statistically significant improvements in the global ECG interpretation or on individual rhythm interpretations.Conclusions:A flip book with multiple ECG rhythms and definitions without the benefit of any outside support was not effective in improving paramedic identification of ECG rhythms on a post-test. Suggestions for further research include repeating the study with a larger sample size; utilizing a lecturer to explain how to use the flip book in the most efficient manner; reiterating how to read and interpret ECGs; and answering questions. Comparing test scores of paramedic students, and newly certified paramedics as opposed to veteran paramedics also may indicate that the flip books are more suited for one group over another.
Hunting for the lowest-mass exoplanets
Authors: Pepe Francesco , Mayor Michel , Lovis Christophe , Benz Willy , Bouchy François , Dumusque Xavier , Queloz Didier , Santos Nuno C. , Ségransan Damien , Udry Stéphane 
Published: November 2011

AbstractIn order to understand general planet characteristics and constrain formation models it is necessary to scan over the widest possible parameter range of discovered systems. Due to detection biases, the domain of very-low mass planets had remained poorly explored. Only with improving measurement precision it has been possible to enter in the sub-Neptune mass range. The HARPS planet search program has been particularly efficient in detecting such ice giants and super earths. The present talk will summarize the obtained results and the characteristics of the low-mass population of exoplanets.
Characterizing planetesimal belts through the study of debris dust
Authors: Moro-Martín Amaya 
Published: November 2011

AbstractMain sequence stars are commonly surrounded by disks of dust. From lifetime arguments, it is inferred that the dust particles are not primordial but originate from the collision of planetesimals, similar to the asteroids, comets and KBOs in our Solar system. The presence of these debris disks around stars with a wide range of masses, luminosities, and metallicities, with and without binary companions, is evidence that planetesimal formation is a robust process that can take place under a wide range of conditions. Debris disks can help us learn about the formation, evolution and diversity of planetary systems.
Lessons from detections of the near-infrared thermal emission of hot Jupiters
Authors: Croll Bryce 
Published: November 2011

AbstractThere have recently been a flood of ground-based detections of the near-infrared thermal emission of a number of hot Jupiters. Although these near-infrared detections have revealed a great deal about the atmospheric characteristics of individual hot Jupiters, the question is: what information does this ensemble of near-infrared detections reveal about the atmospheric dynamics and reradiation of all hot Jupiters? I explore whether there is any correlation between how brightly these planets shine in the near-infrared compared to their incident stellar flux, as was theoretically predicted to be the case. Secondly, I look for whether there is any correlation between the host star's activity and the planet's near-infrared emission, like there is in the mid-infrared, where Spitzer observations have revealed a correlation between the host star activity with the presence, or lack thereof, of a temperature inversion and a hot stratosphere.
A multi-wavelength analysis of the WASP-12 planetary system
Authors: Fossati Luca , Haswell Carole A. , Froning Cynthia S. 
Published: November 2011

AbstractWASP-12 is a 2 Gyr old solar type star, hosting WASP-12b, one of the most irradiated transiting planets currently known. We observed WASP-12 in the UV with the Cosmic Origins Spectrograph (COS) on HST. The light curves we obtained in the three covered UV wavelength ranges, all of which contain many photospheric absorption lines, imply effective radii of 2.69±0.24 RJ, 2.18±0.18 RJ, and 2.66±0.22 RJ, suggesting that the planet is surrounded by an absorbing cloud which overfills the Roche lobe. We clearly detected enhanced transit depths at the wavelengths of the MgII h&k resonance lines. Spectropolarimetric analysis of the host star was also performed. We found no global magnetic field, but there were hints of atmospheric pollution, which might be connected to the very unusual activity of the host star.
GJ 1214b and the prospects for liquid water on super Earths
Authors: Rogers Leslie A. , Seager Sara 
Published: November 2011

AbstractGJ 1214b is one of the first discovered transiting planets having mass (6.55 M⊕) and radius (2.678 R⊕) smaller than Neptune. To account for its low average density (1870 kg m−3), GJ 1214b must have a significant gas component. We use interior structure models to constrain GJ 1214b's gas envelope mass, and to explore the conditions needed to achieve within the planet pressures and temperatures conducive to liquid water. We consider three possible origins for the gas layer: direct accretion of gas from the protoplanetary nebula, sublimation of ices, and outgassing from rocky material. Despite having an equilibrium temperature below 647 K (the critical temperature of water) GJ 1214b does not have liquid water under most conditions we consider. Even if the outer envelope is predominantly sublimated water ice, in our model a low intrinsic planet luminosity (less than 2 TW) is needed for the water envelope to pass through the liquid phase; at higher interior luminosities the outer envelope transitions from a vapor to a super-fluid then to a plasma at successively greater depths.
Uncertainties in tidal theory: Implications for bloated hot Jupiters
Authors: Leconte Jérémy , Chabrier Gilles , Baraffe Isabelle 
Published: November 2011

AbstractThanks to the combination of transit photometry and radial velocity doppler measurements, we are now able to constrain theoretical models of the structure and evolution of objects in the whole mass range between icy giants and stars, including the giant planet/brown dwarf overlapping mass regime (Leconte et al. 2009). In the giant planet mass range, the significant fraction of planets showing a larger radius than predicted by the models suggests that a missing physical mechanism which is either injecting energy in the deep convective zone or reducing the net outward thermal flux is taking place in these objects. Several possibilities have been suggested for such a mechanism:
•downward transport of kinetic energy originating from strong winds generated at the planet's surface (Showman & Guillot 2002),•enhanced opacity sources in hot-Jupiter atmospheres (Burrows et al. 2007),•ohmic dissipation in the ionized atmosphere (Batygin & Stevenson 2010),•(inefficient) layered or oscillatory convection in the planet's interior (Chabrier & Baraffe 2007),•Tidal heating due to circularization of the orbit, as originally suggested by Bodenheimer, Lin & Mardling (2001).
Here we first review the differences between current models of tidal evolution and their uncertainties. We then revisit the viability of the tidal heating hypothesis using a tidal model which treats properly the highly eccentric and misaligned orbits commonly encountered in exoplanetary systems. We stress again that the low order expansions in eccentricity often used in constant phase lag tidal models (i.e. constant Q) necessarily yields incorrect results as soon as the (present or initial) eccentricity exceeds ~ 0.2, as can be rigorously demonstrated from Kepler's equations.
Spin-orbit angles: A probe to evolution
Authors: Triaud Amaury H. M. J. , Queloz Didier , Cameron Andrew Collier 
Published: November 2011

AbstractWe will present our campaign to estimate the projected spin-orbit angle for transiting hot Jupiters, obtained via observations of the Rossiter-McLaughlin effect. Combining our results to those of other teams we show what the current distribution in projected spin-orbit angle is, quickly reminding what interpretation we make of it. Finally we will show early results from a campaign that we initiated, surveying the Rossiter-McLaughlin effect on transiting SB1 intended to provide a comparison sample to the transiting planet's results.
Do falling planets cause stellar spin-up?
Authors: Brown D. J. A. , Cameron A. Collier , Hall C. , Hebb L. 
Published: November 2011

AbstractWe investigate the tidal interactions between hot Jupiter extra-solar planets and their host stars in an effort to characterise the effects of such interactions on stellar rotation. We study the WASP-18 and WASP-19 systems, showing that in both cases tidal interactions cause the eventual spiral in of the the planet towards the Roche limit. We find that for both systems this process will cause significant spin up of the host star, independent of the precise value for the tidal quality factors. By fitting tidal evolution models to observed parameters, we are able to determine that WASP-19 b is currently spiralling in, and that it has a very short remaining lifetime ~ 3 Myr.
Orbital migration models under test
Authors: Kley Wilhelm 
Published: November 2011

AbstractPlanet-disk interaction predicts a change in the orbital elements of an embedded planet. Through linear and fully hydrodynamical studies it has been found that migration is typically directed inwards. Hence, this migration process gives natural explanation for the presence of the ’hot’ planets orbiting close to the parent star, and it plays a mayor role in explaining the formation of resonant planetary systems.However, standard migration models for locally isothermal disks indicate a too rapid inward migration for small mass planets, and a large number of massive planets are found very far away from the star. Recent studies, including more complete disk physics, have opened up new paths to slow down or even reverse migration. The new findings on migration are discussed and connected to the observational properties of planetary systems.
New Worlds, New Horizons and NASA's approach to the next decade of exoplanet discoveries
Authors: Boss Alan P. , Hudgins Douglas M. , Traub Wesley A. 
Published: November 2011

AbstractEvery ten years the astronomy and astrophysics community in the United States undertakes a survey intended to prioritize plans for major ground- and space-based astronomical facilities for the coming decade. New Worlds, New Horizons (NWNH) was released in August 2010 and represents the community's advice to the United States' funding agencies about the top priorities for 2010-2020. Here we focus on the recommendations of NWNH for space-based exoplanet missions to be considered by NASA, and on the plans developed to date for how NASA will respond to the science goals and missions set out for them by NWNH.
Science with EPICS, the E-ELT planet finder
Authors: Gratton Raffaele , Kasper Markus , Vérinaud Christophe , Bonavita Mariangela , Schmid Hans M. 
Published: November 2011

AbstractEPICS is the proposed planet finder for the European Extremely Large Telescope. EPICS is a high contrast imager based on a high performing extreme adaptive optics system, a diffraction suppression module, and two scientific instruments: an Integral Field Spectrograph (IFS) for the near infrared (0.95-1.65 μm), and a differential polarization imager (E-POL). Both these instruments should allow imaging and characterization of planets shining in reflected light, possibly down to Earth-size. A few high interesting science cases are presented.
Observations and modelling of earth's transmission spectrum through lunar eclipses: A window to transiting exoplanet characterization
Authors: Pallé E. , Muñoz Antonio García , Osorio Maria R. Zapatero , Montañés-Rodríguez Pilar , Barrena Rafael , Martín Eduardo L. 
Published: November 2011

AbstractRecently we were able to retrieve the Earth's transmission spectrum through lunar eclipse observations. This spectrum showed that the depth of most molecular species was stronger than models had anticipated. The presence of other atmospheric signatures, such as atmospheric dimers, were also present in the spectrum. We have been developing a radiative transfer code able to reproduce the Earth's transmission spectra at different depths into the penumbra and umbra, and taking into account transmission, refraction, and multiple scattering. Here we discuss the results to date and the work ahead.
Characterisation of SPH noise in simulations of protoplanetary discs
Authors: Arena Serena E. , Gonzalez Jean-François , Crespe Elisabeth 
Published: November 2011

AbstractThe effects of turbulence on the dynamics of dust grains in protoplanetary discs is of relevant importance in the study of pre-planetesimal formation. The complex interplay between gas and dust and the modelling of turbulence require numerical simulations.A statistical study of the noise in SPH simulations of gas-only protoplanetary accretion discs is performed in order to determine if it could mimic turbulence and to what extent.
Planet candidates from the SARG visual binary survey
Authors: Carolo Elena , Desidera Silvano , Gratton Raffaele , Fiorenzano Aldo Martinez , Endl Michael , Cosentino Rosario , Barbieri Mauro , Bonavita Mariangela , Cecconi Massimo , Claudi Riccardo , Marzari Francesco , Scuderi Salvo 
Published: November 2011

AbstractWe present preliminary results of the radial velocity survey on going at TNG targeting binaries with similar components.
Influence of growth on dust settling and migration in protoplanetary discs
Authors: Crespe Elisabeth , Gonzalez Jean-Francois , Laibe Guillaume , Maddison Sarah T. , Fouchet Laure 
Published: November 2011

AbstractTo form meter-sized pre-planetesimals in protoplanetary discs, dust aggregates have to decouple from the gas at a distance far enough from the central star so they are not accreted. Dust grains are affected by gas drag, which results in a vertical settling towards the mid-plane, followed by radial migration. To have a better understanding of the influence of growth on the dust dynamics, we use a simple grain growth model to determine the dust distribution in observed discs. We implement a constant growth rate into a gas+dust hydrodynamics SPH code and vary the growh rate to study the resulting effect on dust distribution. The growth rate allows us to determine the relative importance between friction and growth.We show that depending on the growth rate, a range of dust distribution can result. For large enough growth rates, grains can decouple from the gas before being accreted onto the central star, thus contributing as planetary building rocks.
3D global simulations of proto-planetary disk with dynamically evolving outer edge of dead zone
Authors: Dzyurkevich Natalia , Turner Neal J. , Kley Willy , Klahr Hubert , Henning Thomas 
Published: November 2011

Abstract3D global MHD simulations of magneto-driven turbulence are performed for the disk of 100 AU with reduced amount of 10μm fluffy dust grains. We use X-ray and cosmic ray ionization, as well as simplified treatment of recombination on dust grains. The ionization of gas and charging of dust grains are dynamically evolving during the simulation, making the zone of high magnetic dissipation (’dead’ zone) variable. In our simulations, the jump in MRI-driven turbulent viscosity inside and outside of dead zone is insignificant. We find no hard edge, but rather a smooth transition between active and dead zone. Subsequently, there is no visible pressure bump at outer edge of the dead zone.
Planetary systems formation and the diversity of extrasolar systems
Authors: Miguel Yamila , Guilera Octavio M. , Brunini Adrián 
Published: November 2011

AbstractWith the end of answer questions as, how common are planetary systems like our own in the Universe? and What is the diversity of planetary systems that we could find in the universe?, we develop a semi-analytical model for computing planetary systems formation and consider different initial conditions for generating a large sample of planetary systems, which is analysed statistically. We explore the effects in the planetary system architecture of assuming different initial disc profiles and planetary migration rates.
The effect of opacity on the evolution of giant planets
Authors: Vazan Allona , Kovetz Attay , Podolak Morris 
Published: November 2011

AbstractWe use an improved version of the planetary evolution code described in Helled et al. (2006) to model the effect of opacity on the evolution of giant planets in the disk instability scenario. We find that changing the opacity law can cause significant changes in the evolutionary path of a protoplanet. Sufficiently high opacities cause oscillatory behavior that delays the final collapse. Peak luminosities just before collapse can exceed 10−5L⊙.