bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow of Planets Raises Short Period Fall-Off
Authors: Taylor Stuart F. 
Published: April 2014

AbstractAfter finding more planets than expected at the shortest period, there has been an effort to explain their numbers by weak tidal friction. However, we find that the strength of tidal dissipation that would produce the occurence distribution found from Kepler planet candidates is different for giant versus medium radii planets. This discrepancy can be resolved if there is a “flow” of the largest planets regularly arriving such that they go through a “hot Jupiter” stage. We also show a correlation of higher stellar Fe/H with higher eccentricity of giant planets that may be from smaller planets having been sent into the star by the migration of the larger planet. This disruption of the orbits of medium and smaller planets could account for the lower occurrence of “hot Neptune” medium radius planets.
Planetesimal Capture by an Evolving Giant Gaseous Protoplanet
Authors: Podolak Morris , Haghighipour Nader 
Published: April 2014

AbstractBoth the core-accretion and disk-instability models suggest that at the last stage of the formation of a gas-giant, the core of this object is surrounded by an extended gaseous envelope. At this stage, while the envelope is contracting, planetesimals from the protoplanetary disk may be scattered into the protoplanets atmosphere and deposit some or all of their materials as they interact with the gas. We have carried out extensive simulations of approximately 104 planetesimals interacting with a envelope of a Jupiter-mass protoplanet including effects of gas drag, heating, and the effect of the protoplanets extended mass distribution. Simulations have been carried out for different radii and compositions of planetesimals so that all three processes occur to different degrees. We present the results of our simulations and discuss their implications for the enrichment of ices in giant planets. We also present statistics for the probability of capture (i.e. total mass-deposition) of planetesimals as a function of their size, composition, and closest approach to the center of the protoplanetary body.
On the Climatic Impact of CO2Ice Particles in Atmospheres of Terrestrial Exoplanets
Authors: Kitzmann D. , Patzer A. B. C. , Rauer H. 
Published: April 2014

AbstractClouds play a significant role for the energy budget in planetary atmospheres. They can scatter incident stellar radiation back to space, effectively cooling the surface of terrestrial planets. On the other hand, they may contribute to the atmospheric greenhouse effect by trapping outgoing thermal radiation. For exoplanets near the outer boundary of the habitable zone, condensation of CO2can occur due to the low atmospheric temperatures. These CO2ice clouds may play an important role for the surface temperature and, therefore, for the question of habitability of those planets. However, the optical properties of CO2ice crystals differ significantly from those of water droplets or water ice particles. Except for a small number of strong absorption bands, they are almost transparent with respect to absorption. Instead, they are highly effective scatterers at long and short wavelengths. Therefore, the climatic effect of a CO2ice cloud will depend on how much incident stellar radiation is scattered to space in comparison to the amount of thermal radiation scattered back towards the planetary surface. This contribution aims at the potential greenhouse effect of CO2ice particles. Their scattering and absorption properties are calculated for assumed particle size distributions with different effective radii and particle densities. An accurate radiative transfer model is used to determine the atmospheric radiation field affected by such CO2particles. These results are compared to less detailed radiative transfer schemes employed in previous studies.
Assimilating and Modeling Dust Transport in the Martian Climate System
Authors: Ruan Tao , Montabone Luca , Read Peter L. , Lewis Stephen R. 
Published: April 2014

AbstractA meteorological data assimilation system has been developed recently for analyzing measurements of temperature and dust opacity on Mars and has been successfully applied in several studies (e.g. Montabone et al. 2005, Lewis et al. 2007) to study various atmospheric phenomena. A more sophisticated data assimilation system, now with full dust transport incorporated, is becoming available to represent more accurately and realistically the physical transport of dust.
Microarcsecond Astrometry with MCAO Using a Diffractive Mask
Authors: Ammons S. Mark , Bendek Eduardo A. , Guyon Olivier , Macintosh Bruce , Savransky Dmitry 
Published: April 2014

AbstractWe present a new ground-based technique to detect or follow-up long-period, potentially habitable exoplanets via precise relative astrometry of host stars using Multi-Conjugate Adaptive Optics (MCAO) on 8 meter telescopes equipped with diffractive masks. MCAO improves relative astrometry both by cancellation of high-altitude atmospheric layers, which induce dynamic focal-plane distortions, and the improvement of centroiding precision with sharper PSFs. However, mass determination of habitable exoplanets requires multi-year reference grid stability of ~1–10 μas or nanometer-level stability on the long-term average of out-of-pupil phase errors, which is difficult to achieve with MCAO (e.g., Meyer et al. 2011). The diffractive pupil technique calibrates dynamic distortion via extended diffraction spikes generated by a dotted primary mirror, which are referenced against a grid of background stars (Guyon et al. 2012). The diffractive grid provides three benefits to relative astrometry: (1) increased dynamic range, permitting observation of V < 10 stars without saturation; (2) calibration of dynamic distortion; and (3) a spectrum of the target star, which can be used to calibrate the magnitude of differential atmospheric refraction to the microarcsecond level. A diffractive 8-meter telescope with diffraction-limited MCAO in K-band reaches < 3–5 μas relative astrometric error per coordinate perpendicular to the zenith vector in one hour on a bright target star in fields of moderate stellar density (~10–40 stars arcmin−2). We present preliminary on-sky results of a test of the diffractive mask on the Nickel telescope at Lick Observatory.
Quantitative Stellar Classification with Low-Resolution Spectroscopy
Authors: Eiff Matthias Ammler-von , Sebastian Daniel , Guenther Eike W. 
Published: April 2014

AbstractLow-resolution spectroscopy (R ≈ 1000) is used to efficiently characterize faint stars suspected to host planets. Stellar parameters, i.e. effective temperature, surface gravity, and metallicity can be assessed from these spectra by methods of quantitative classification. For this purpose, more than 130 template stars have been observed with the faint object spectrograph at the Tautenburg 2m telescope, Germany. A large number of lines are measured and the dependence of line depths on stellar parameters is studied.
Laser Speckles from Multimode Fiber under Scrambling
Authors: Yu Hongfei , Han Jian , Xiao Dong 
Published: April 2014

AbstractWhen a laser beam transmits through a multi-mode fiber, speckles show in the output beam. In this work, we study the laser speckle under static and dynamic scrambling by the histogram and line profile of far-field pattern. The results show that static scrambling has little effect on the intensity distribution. The dynamic scrambling reduces the speckles without changing the line profile. Two possible explanations are proposed.
Study of the HARPS Line Profile Using a Laser Frequency Comb
Authors: Zhao F. , Curto G. Lo , Pasquini L. , Zhao G. 
Published: April 2014

AbstractHigh precision spectroscopy is one of the most successful methods to detect extra-solar planets. To enable the detection of Earth-like planets in the habitable zone, extremely precise instruments are required. Our lack of knowledge of the instrument line profile, non-linearity and charge transfer efficiency effects in the detector limits the achievable precision of an instrument. We report our studies on the HARPS (High Accuracy Radial- velocity Planet Searcher) line profiles, measured using the unresolved lines of a Laser Frequency Comb (LFC). We show how the line profile changes as a function of position and signal, and estimate the errors made in the line centroid measurement due to the variation of the line profile.
Eliminating Noise at the Box-fitting Spectrum
Authors: Boufleur Rodrigo Carlos , Emilio Marcelo , Pacheco Eduardo Janot , de La Reza Jorge Ramiro , da Rocha José Carlos 
Published: April 2014

AbstractNon gaussian sources of erros need to be taken into consideration when searching for planetary transits. Such phenomena are mostly caused by the impact of high energetic particles on the detector (Pinheiro da Silva et al. 2008). The detection efficiency of transits, therefor, depend significantly on the data quality and the algorithms utilized to deal with these errors sources. In this work we show that a modified detrend algorithm CDA (CoRoT Detrend Algorithm; Mislis et al. 2010) using a robust statistics and an empirical fit, instead of a polynomial one, can eliminate more efficiently gaps in the data and other long-term trends from the light-curve. Using this algorithm enables us to obtain a reconstructed light-curve with better signal-to-noise ratio that allows to improve the detection of exoplanet transits, although long term signals are destroyed. The results show that these modifications lead to an improved BLS (Box-fitting Least Squares; Kovács, Zucker & Mazeh 2002) algorithm spectrum. At the end we have compared our planetary search results with CoRoT (Convection, Rotation and planetary Transits) satellite chromatic light-curves available in the literature.
SPICES: A Mission Concept to Characterize Long Period Planets from Giants to Super-Earths
Authors: Boccaletti Anthony , Maire Anne-Lise , Galicher Raphaël , Baudoz Pierre , Mawet Dimitri , Trauger John , Schneider Jean , Traub Wes , Stam Daphne , Lagage Pierre-Olivier , Gratton Raffaele ,   the SPICES team
Published: April 2014

AbstractSPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) was proposed in 2010 for a five-year M-class mission in the context of ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets located at several AUs (0.5-10 AU) from nearby stars (<25 pc) with masses ranging from a few Jupiter masses down to super-Earths (~2 Earth radii, ~10 M⊕), possibly habitable. In addition, circumstellar disks as faint as a few times the zodiacal light in the Solar System can be studied. SPICES is based on a 1.5-m off-axis telescope and can perform spectro-polarimetric measurements in the visible (450 - 900 nm) at a spectral resolution of about 40. This paper summarizes the top science program and the choices made to conceive the instrument. The performance is illustrated for a few emblematic cases.
NEAT: An Astrometric Mission to Detect and Characterize Nearby Habitable Planetary Systems
Authors: Malbet Fabien , Crouzier Antoine , Goullioud Renaud , Lagage Pierre-Olivier , Léger Alain , Shao Mike ,   the NEAT collaboration
Published: April 2014

AbstractMany planets have been detected so far but very few around nearby stars that could allow characterization of their atmosphere thanks to their proximity. There are known exoplanets around less than 8.3% of the FGK stars of the Solar neighborhood (d<20 pc) and the vast majority of them are giant planets. Within the ESA Cosmic Vision 2015-2025 plan, the scientific goal of the NEAT (Nearby Earth Astrometric Telescope) mission is to detect and characterize planetary systems around these nearby stars in an exhaustive way down to 1 Earth-mass in the habitable zone. This survey would provide the actual planetary masses, the full characterization of the orbits including their inclination, for all the components of the planetary system down to the Earth-mass limit. NEAT will continue the work performed by Hipparcos and Gaia by reaching a precision that is improved by two orders of magnitude on pointed targets compared to Gaia. We present the free-flyer concept that has been submitted to the 2010 ESA call for M3 missions with two satellites flying in formation 40m apart.
Siple Dome ice reveals two modes of millennial CO2 change during the last ice age
Authors: Ahn Jinho , Brook Edward J. 
Published: April 2014

AbstractReconstruction of atmospheric CO2 during times of past abrupt climate change may help us better understand climate-carbon cycle feedbacks. Previous ice core studies reveal simultaneous increases in atmospheric CO2 and Antarctic temperature during times when Greenland and the northern hemisphere experienced very long, cold stadial conditions during the last ice age. Whether this relationship extends to all of the numerous stadial events in the Greenland ice core record has not been clear. Here we present a high-resolution record of atmospheric CO2 from the Siple Dome ice core, Antarctica for part of the last ice age. We find that CO2 does not significantly change during the short Greenlandic stadial events, implying that the climate system perturbation that produced the short stadials was not strong enough to substantially alter the carbon cycle.
Maternal nutrition at conception modulates DNA methylation of human metastable epialleles
Authors: Dominguez-Salas Paula , Moore Sophie E. , Baker Maria S. , Bergen Andrew W. , Cox Sharon E. , Dyer Roger A. , Fulford Anthony J. , Guan Yongtao , Laritsky Eleonora , Silver Matt J. , Swan Gary E. , Zeisel Steven H. , Innis Sheila M. , Waterland Robert A. , Prentice Andrew M. , Hennig Branwen J. 
Published: April 2014

AbstractIn experimental animals, maternal diet during the periconceptional period influences the establishment of DNA methylation at metastable epialleles in the offspring, with permanent phenotypic consequences. Pronounced naturally occurring seasonal differences in the diet of rural Gambian women allowed us to test this in humans. We show that significant seasonal variations in methyl-donor nutrient intake of mothers around the time of conception influence 13 relevant plasma biomarkers. The level of several of these maternal biomarkers predicts increased/decreased methylation at metastable epialleles in DNA extracted from lymphocytes and hair follicles in infants postnatally. Our results demonstrate that maternal nutritional status during early pregnancy causes persistent and systemic epigenetic changes at human metastable epialleles.
High-temperature electromagnons in the magnetically induced multiferroic cupric oxide driven by intersublattice exchange
Authors: Jones S. P. P. , Gaw S. M. , Doig K. I. , Prabhakaran D. , Hétroy Wheeler E. M. , Boothroyd A. T. , Lloyd-Hughes J. 
Published: April 2014

AbstractMagnetically induced ferroelectric multiferroics present an exciting new paradigm in the design of multifunctional materials, by intimately coupling magnetic and polar order. Magnetoelectricity creates a novel quasiparticle excitation—the electromagnon—at terahertz frequencies, with spectral signatures that unveil important spin interactions. To date, electromagnons have been discovered at low temperature (<70 K) and predominantly in rare-earth compounds such as RMnO3. Here we demonstrate using terahertz time-domain spectroscopy that intersublattice exchange in the improper multiferroic cupric oxide (CuO) creates electromagnons at substantially elevated temperatures (213–230 K). Dynamic magnetoelectric coupling can therefore be achieved in materials, such as CuO, that exhibit minimal static cross-coupling. The electromagnon strength and energy track the static polarization, highlighting the importance of the underlying cycloidal spin structure. Polarized neutron scattering and terahertz spectroscopy identify a magnon in the antiferromagnetic ground state, with a temperature dependence that suggests a significant role for biquadratic exchange.
Antiferromagnetic Metal and Mott Transition on Shastry-Sutherland Lattice
Authors: Liu Hai-Di , Chen Yao-Hua , Lin Heng-Fu , Tao Hong-Shuai , Liu Wu-Ming 
Published: April 2014

AbstractThe Shastry-Sutherland lattice, one of the simplest systems with geometrical frustration, which has an exact eigenstate by putting singlets on diagonal bonds, can be realized in a group of layered compounds and raises both theoretical and experimental interest. Most of the previous studies on the Shastry-Sutherland lattice are focusing on the Heisenberg model. Here we opt for the Hubbard model to calculate phase diagrams over a wide range of interaction parameters and show the competing effects of interaction, frustration and temperature. At low temperature, frustration is shown to favor a paramagnetic metallic ground state, while interaction drives the system to an antiferromagnetic insulator phase. Between these two phases, there are an antiferromagnetic metal phase and a paramagnetic insulator phase (which should consist of a small plaquette phase and a dimer phase) resulting from the competition of the frustration and the interaction. Our results may shed light on more exhaustive studies about quantum phase transitions in geometrically frustrated systems.
The prevalences of impaired fasting glucose and diabetes mellitus in working age men of North China: Anshan Worker Health Survey
Authors: Liu Lei , Zhou Chuang , Du Hang , Zhang Kai , Huang Desheng , Wu Jingyang , Anshan Worker Health Survey Group  
Published: April 2014

AbstractTo investigate the prevalence of impaired fasting glucose (IFG) and total diabetes mellitus (DM) including known diabetes and newly diagnosed diabetes in working age men of North China. A cross-section study was conducted at health medical center of Ansteel Group Hospital in Anshan city of China. 37,345 males between 20–60 years of age were recruited in this study. Age-standardized prevalence of IFG and total DM in these working age men were 25.3% and 8.4%, respectively. The prevalence of IFG and total DM increased, as the age progressed. After multinomial logit analysis, age, systolic blood pressure, drinking, smoking, overweight and obesity, total cholesterol, triglycerides, serum creatinine and blood urea nitrogen were independent risk factors for both IFG and DM. The prevalence rate of IFG in Anshan male workers was higher compared with mainland China overall. Diabetes-related education and popularization of DM prevention programs should be actively carried out with age increasing.
Pavlovian conditioning and cross-sensitization studies raise challenges to the hypothesis that overeating is an addictive behavior
Authors: Harb M R , Almeida O F X 
Published: April 2014

AbstractElevated glucocorticoid levels and sign tracking (ST) in Pavlovian conditioning are potential biomarkers of compulsive behaviors such as addiction. As overeating is sometimes viewed as a form of addictive behavior, we hypothesized that murine Pavlovian sign trackers would have a greater propensity to overeat and develop obesity. Using a food reward in the classical conditioning paradigm, we show that ST behavior is a robust conditioned response but not a predictor of eating and growth trajectories in mice, thus challenging the view that the development of obesity and drug addiction depend on identical mechanisms. This interpretation was supported by experiments which showed that overweight mice do not display cross-sensitization to an addictive drug (morphine), and conversely, that overweight morphine-sensitized animals do not overconsume a highly rewarding food. Although the rewarding/motivational effects of both food and drugs of abuse are mediated by similar neurochemical mechanisms, obesity and drug addiction represent a summation of other dysfunctional input and output pathways that lead to the emergence of two distinct disorders, each of which would deserve a specific pharmacotherapeutic approach.
Rate of false conviction of criminal defendants who are sentenced to death
Authors: Gross Samuel R. , O’Brien Barbara , Hu Chen , Kennedy Edward H. 
Published: April 2014

Significance
The rate of erroneous conviction of innocent criminal defendants is often described as not merely unknown but unknowable. We use survival analysis to model this effect, and estimate that if all death-sentenced defendants remained under sentence of death indefinitely at least 4.1% would be exonerated. We conclude that this is a conservative estimate of the proportion of false conviction among death sentences in the United States.
Juvenile hormone regulates body size and perturbs insulin signaling in
Drosophila
Authors: Mirth Christen Kerry , Tang Hui Yuan , Makohon-Moore Sasha C. , Salhadar Samy , Gokhale Rewatee H. , Warner Raechel D. , Koyama Takashi , Riddiford Lynn M. , Shingleton Alexander W. 
Published: April 2014

Significance
Understanding how organisms regulate their body size is a fundamental problem in biology. Body size regulation involves the careful integration of mechanisms that control growth rate with those that control growth duration. In insects, developmental hormones such as juvenile hormone and ecdysone regulate developmental transitions and growth duration. The conserved insulin-signaling pathway regulates growth rates. Our studies reveal an intimate link between the three, whereby juvenile hormone controls body size by regulating ecdysone synthesis, which in turn modifies insulin signaling. In vertebrates, hormones such as androgens and estrogens interact with insulin signaling to influence tumor growth. By studying the developmental context of hormone interactions, our data reveal fundamental features of body size regulation that have important consequences for understanding cancer growth.
Projected changes in African easterly wave intensity and track in response to greenhouse forcing
Authors: Skinner Christopher Bryan , Diffenbaugh Noah S. 
Published: April 2014

Significance
African easterly waves (AEWs) are ubiquitous weather disturbances over the tropical Atlantic basin during the summer season. However, despite the critical influence of AEWs on Sahel rainfall, transport of Saharan dust, and initiation of Atlantic hurricanes, little is known about how global warming influences AEW activity. We use an ensemble of general circulation models to investigate the response of AEWs to elevated greenhouse gas concentrations. We find that increases in regional temperature gradients and the strength of convergence and uplift along the Intertropical Front of Africa lead to increases in the strength of AEWs. Given the relationships that are observed in the current climate, changes in AEW strength could influence climate over both West Africa and the larger Atlantic basin.
Drosha as an interferon-independent antiviral factor
Authors: Shapiro Jillian S. , Schmid Sonja , Aguado Lauren C. , Sabin Leah R. , Yasunaga Ari , Shim Jaehee V. , Sachs David , Cherry Sara , tenOever Benjamin R. 
Published: April 2014

Significance
Virus infections must be combated at a cellular level. The strategies used to inhibit virus differ dramatically when comparing plants and insects to mammals. Here, we identify an evolutionary conserved antiviral response that is independent of these known defenses. We demonstrate that an RNA nuclease called Drosha is repurposed during virus infection to cleave viral RNA and modulate the cellular environment as a means of inhibiting virus replication.