bluuebunny/crossref_metadata_2025 huggingface dataset:
LATE SPANISH DOCTORS ON USURY, AND THE EVOLVING SCHOLASTIC TRADITION
Authors: Monsalve Fabio
Published: April 2014

The scholastic intellectual tradition was the dominant scientific paradigm for nearly five centuries in western Europe. That the economic issues of interest to these scholars were similar throughout the period is undisputable, but were the individual views on these issues also similar? This is a pertinent question, upon which an evaluation of the evolution of this intellectual tradition, which often has been considered as monolithic, can be based.

This paper focuses on the analysis of the so-called “natural law case” against usury, and tracks how the lines of intellectual reasoning subtly evolved between early and late scholastics. While the issues, methods, and purposes of scholastic thought remained the same in this period, there also was a systematic evolution within this tradition that makes the essence of the scholastic doctrines conformable to economic realities.
HIGH LEVELS OF UNEMPLOYMENT IN THE MERCANTILIST ERA
Authors: Letiche John M.
Published: April 2014

This article draws attention to the high levels of unemployment in the mercantilist era, a parallel to conditions in the less developed countries at the present time. Understandably, distinguished economists of the twentieth century, writing before the publication of Keynes’ General Theory, tended to underestimate this problem. Actual causes of the high levels of unemployment are examined, including the fluctuating impacts of merchant entrepreneurs, agricultural revolutions, political unrest, and warfare, as well as nutritional deficiencies, which contributed directly to unemployment.
The role of eating frequency on total energy intake and diet quality in a low-income, racially diverse sample of schoolchildren
Authors: Evans E Whitney , Jacques Paul F , Dallal Gerard E , Sacheck Jennifer , Must Aviva
Published: April 2014

Objective

The relationship of meal and snacking patterns with overall dietary intake and relative weight in children is unclear. The current study was done to examine how eating, snack and meal frequencies relate to total energy intake and diet quality.

Design

The cross-sectional associations of eating, meal and snack frequencies with total energy intake and diet quality, measured by the Healthy Eating Index 2005 (HEI-2005), were examined in separate multivariable mixed models. Differences were examined between elementary school-age participants (9–11 years) and adolescents (12–15 years).

Setting

Two non-consecutive 24 h diet recalls were collected from children attending four schools in the greater Boston area, MA, USA.

Subjects

One hundred and seventy-six schoolchildren, aged 9–15 years.

Results

Overall, 82 % of participants consumed three daily meals. Eating, meal and snack frequencies were statistically significantly and positively associated with total energy intake. Each additional reported meal and snack was associated with an 18·5 % and a 9·4 % increase in total energy intake, respectively (P<0·001). The relationships of eating, meal and snack frequencies with diet quality differed by age category. In elementary school-age participants, total eating occasions and snacks increased HEI-2005 score. In adolescents, each additional meal increased HEI-2005 score by 5·40 points (P=0·01), whereas each additional snack decreased HEI-2005 score by 2·73 points (P=0·006).

Conclusions

Findings suggest that snacking increases energy intake in schoolchildren. Snacking is associated with better diet quality in elementary school-age children and lower diet quality in adolescents. Further research is needed to elucidate the role of snacking in excess weight gain in children and adolescents.
Radial-Velocity Searches for Exoplanets in East Asia
Authors: Sato Bun'ei
Published: April 2014

Hundreds of extrasolar planets have been discovered around various types of stars by various techniques during the past decade. Among them precise radial velocity measurements for stars are fundamental technique to detect and confirm exoplanets. In this paper activities in East-Asian region in this research field are introduced: East-Asian Planet Search Network, which is a network searching for planets around evolved intermediate-mass stars, and Subaru/IRD project, which will search for habitable planets around M-type dwarfs using infrared radial-velocity method.
Current and Future of Microlensing Exoplanet Search
Authors: Sumi Takahiro
Published: April 2014

Gravitational microlensing has a unique sensitivity to exoplanets at outside of the snow-line with masses down to the Earth-mass. Because of the rarity and short timescale of the planetary signal, the survey groups, MOA-II in New Zealand and OGLE-IV in Chile carry out the wide field survey observation towards the galactic bulge to issue alerts in real time. Then telescopes of the follow-up groups conduct high cadence follow-up observation to get dense sampling of the short planetary signal. Recent high cadence survey observations by MOA-II and OGLE-IV have started to find exoplanets without follow-up observation systematically. This is a transition to the next generation 24-hour high cadence survey network which can reveal the mass function of exoplanets down to Earth-mass outside of the snow-line. The Wide Field Infrared Survey Telescope (WFIRST) is the highest ranked recommendation for a large space mission in the recent New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey. Exoplanet microlensing program is one of the primary science of WFIRST. WFIRST will find about 2,000 bound planets and 1,000 unbound planets by the high precision continuous survey with 15 min. cadence. WFIRST can complete the statistical census of planetary systems in the Galaxy, from the outer habitable zone to gravitationally unbound planets – a discovery space inaccessible to other exoplanet detection techniques.
Detection and Characterization of Transiting Systems with Smaller Exoplanets
Authors: Hirano Teruyuki , Narita Norio , Fukui Akihiko , Sanchis-Ojeda Roberto , Winn Joshua N. , Suto Yasushi , Taruya Atsushi
Published: April 2014

We present our effort to detect and characterize transiting systems with small exoplanets. First we present our on-going project to detect transiting exoplanets around late-type stars. As many authors point out, late-type stars can host potentially habitable rocky planets, whose transits are detectable with 2-meter class telescopes. We aim at detecting (small-sized) transiting exoplanets around M-type stars and are conducting a survey using the Okayama 1.88m telescope. We introduce our campaign at Okayama. Next we discuss the characterization of small-sized exoplanets. We focus on the measurement of the spin-orbit angle, the angle between the stellar spin axis and planetary orbital axis. The spin-orbit relations are of great importance in discussing planetary formations, evolutions, and migrations. To this point, the Rossiter-McLaughlin (RM) effect, an apparent radial velocity anomaly during a planetary transit, has been mainly investigated to measure the projected spin-orbit angles. However, as the size of the transiting planet becomes smaller, the detection of the RM effect becomes challenging because of the small RM signal. We have newly developed a technique to investigate spin-orbit relations for smaller planets by combining Kepler's ultra-precise photometry and spectroscopic measurements. We show that, contrary to planetary systems with close-in giant planets, most of the systems with small-sized planets (including Earth-sized ones) have smaller spin-orbit angles, which implies a different evolutional history of the planetary systems. We also discuss future prospects on the detection and characterization of smaller transiting exoplanets.
Signatures of Earth-Like Planets in the Chemical Composition of Solar-Type Stars
Authors: Meléndez Jorge , Ramírez Iván
Published: April 2014

The formation of terrestrial and gas giant planets has likely imprinted signatures on the chemical composition of their parent stars, as shown for example by the higher occurrence of giant planets for higher stellar metallicities. There are two new signatures that have been recently proposed by Meléndez et al. (2009, 2012) and Ramírez et al. (2009, 2010) for the formation of rocky planets, and by Ramírez et al. (2011) for gas giant planets. We review here our on-going work on the planet-star connection using solar twins, for which chemical abundances are being obtained at unprecedented precision (0.01 dex).
New MOST Photometry of the 55 Cancri System
Authors: Dragomir Diana , Matthews Jaymie M. , Winn Joshua N. , Rowe Jason F. ,   MOST Science Team
Published: April 2014

Since the discovery of its transiting nature, the super-Earth 55 Cnc e has become one of the most enthusiastically studied exoplanets, having been observed spectroscopically and photometrically, in the ultraviolet, optical and infrared regimes. To this rapidly growing data set, we contribute 42 days of new, nearly continuous MOST photometry of the 55 Cnc system. Our analysis of these observations together with the discovery photometry obtained in 2011 allows us to determine the planetary radius (1.990+0.084−0.080) and orbital period (0.7365417+0.0000025−0.0000028) of 55 Cnc e with unprecedented precision. We also followed up on the out-of-transit phase variation first observed in the 2011 photometry, and set an upper limit on the depth of the planet's secondary eclipse, leading to an upper limit on its geometric albedo of 0.6.
A Campaign for the Detection of Earth-Mass Planets in the Habitable Zone of Alpha Centauri
Authors: Wittenmyer Robert A. , Endl Michael , Bergmann Christoph , Hearnshaw John , Barnes Stuart I. , Wright Duncan
Published: April 2014

We review the possible formation and orbital stability of Earth-mass or super Earth-mass planets around either of the stars Alpha Centauri A or B and describe a program at Mt John University Observatory using the Doppler method that aims to detect such planets. From New Zealand, we are able to observe the Alpha Centauri system year-round. This is critical in order to acquire data of sufficient quantity and phase coverage to detect the orbit of a terrestrial-mass planet in the habitable zone. Our observations are being made at high resolution (R = 70,000) and high signal-to-noise with the Hercules vacuum echelle spectrograph attached to the 1-m McLellan telescope by a 25-m long optical fibre and using an iodine cell. We discuss the velocity precision and instrumental stability required for success and outline the progress of the observations so far. At present we are collecting about 10,000 observations of each star, A and B, per year with a typical precision of 2.5 m/s per observation.
Present and Future Detection of Terrestrial Biomarkers on Earthshine
Authors: Briot Danielle , Arnold Luc , Jacquemoud Stéphane , Schneider Jean
Published: April 2014

In the context of life detection on terrestrial exoplanets, new methods of search for spectral signatures of chlorophyll and other biomarkers in the Earthshine have been developed in the last few decades. Astronomical observations made at OHP and ESO (NTT) showed a significant signal when continents are facing the Moon. This signal, called the Vegetation Red Edge (VRE), is undoubtedly due to chlorophyll absorption properties. In order to strengthen these results, the LUCAS (LUmière Cendrée en Antarctique par Spectroscopie) project dedicated to the measurement of the Earthshine from the Concordia Research Station (C Dome, Antarctica) has been set up. One of the objectives of LUCAS was to observe prolonged variations of the VRE corresponding to various parts of the Earth facing the Moon. An extension of this project, called LUCAS II, would allow long-term observations to detect seasonal variations of the vegetation signal. These data, together with accurate measurements of the Earth's albedo, will help validate a model of global and spectral albedo of our planet.
The Kepler Completeness Study: A Pipeline Throughput Experiment
Authors: Christiansen Jessie L. , Clarke Bruce D. , Burke Christopher J. , Jenkins Jon M. ,   the Kepler Completeness Working Group
Published: April 2014

The Kepler Mission was designed to measure the frequency of Earth-like planets in the habitable zone of Sun-like stars. A requirement for determining the underlying planet population from a sample of detected planets is understanding the completeness of that sample—what fraction of the planets that could have been discovered in a given data set were actually detected. Here we describe an experiment designed to address a specific aspect of that question, which is the issue of signal throughput efficiency. We investigate the extent to which the Kepler pipeline preserves transit signals by injecting simulated transit signals into the pixel-level data, processing the modified pixels through the pipeline, and measuring their detection statistics. For the single channel that we examine initially, we inject simulated transit signal trains into the pixel time series of each of the 1801 targets for the 89 days that constitute Quarter 3. For the 1680 that behave as expected in the pipeline, on average we find the strength of the injected signal is recovered at 99.6% of the strength of the original signal. Finally we outline the further work required to characterise the completeness of the Kepler pipeline.
The New Photometric Observations for Transiting Exoplanet HAT-P-24b
Authors: Wang Xiao-Bin , Cameron Andrew Collier , Gu Sheng-Hong
Published: April 2014

The transiting exoplanetary system HAT-P-24 was observed by using CCD cameras at Yunnan Observatory and Hokoon Astronomical Centre, China in 2010 and 2012. Three new transit light curves are analyzed by means of MCMC technique, and the new physical parameters of the system are derived, which are compatible with the old ones in the discovery paper. The orbital period of HAT-P-24b is refined and no obvious TTV signal can be found from five transit events during 2010-2012.
Recent Kepler Results On Circumbinary Planets
Authors: Welsh William F. , Orosz Jerome A. , Carter Joshua A. , Fabrycky Daniel C. ,   the Kepler Team
Published: April 2014

Ranked near the top of the long list of exciting discoveries made with NASA's Kepler photometer is the detection of transiting circumbinary planets. In just over a year the number of such planets went from zero to seven, including a multi-planet system with one of the planets in the habitable zone (Kepler-47). We are quickly learning to better detect and characterize these planets, including the recognition of their transit timing and duration variation “smoking gun” signature. Even with only a handful of such planets, some exciting trends are emerging.
Eclipsing Binaries: Precise Clocks to Detect Extrasolar Planets
Authors: Kundra Emil , Pribulla Theodor , Vaňko Martin , Hambálek Ľubomír
Published: April 2014

Project Dwarf is a new observing campaign focused on the detection of substellar companions to low-mass (composed of late-type, subdwarf (sd) or/and white dwarf (WD) components) detached eclipsing binaries using minima timing. The crucial condition for the object selection for this campaign is possibility to determine times of the minima with high precision. This is naturally fullfilled for eclipsing binaries with deep and narrow minima or systems hosting a WD component showing fast ingress or egress.

The observing project includes three groups of close eclipsing binaries indicating presence of substellar circum-binary components:

(i)

systems with K or/and M dwarf components

(ii)

systems with hot subdwarf (sd) and M dwarf components

(iii)

systems with white dwarf (WD) component(s).

The sample of the eclipsing systems have orbital periods in range of 0.1 to almost 3 days and their brightness fits possibilities of small telescopes equipped with a low-end CCD camera and at least VRI filter set. Such kind of telescopes allow us to develop observing network including also amateur astronomers.
Detection of Exomoons Inside the Habitable Zone
Authors: Tusnski Luis Ricardo M. , Valio Adriana
Published: April 2014

Since the discovery of the first exoplanets, those most adequate for life to begin and evolve have been sought. Due to observational bias, however, most of the discovered planets so far are gas giants, precluding their habitability. However, if these hot Jupiters are located in the habitable zones of their host stars, and if rocky moons orbit them, then these moons may be habitable. In this work, we present a model for planetary transit simulation considering the presence of moons around a planet. The moon orbit is considered to be circular and coplanar with the planetary orbit. The other physical and orbital parameters of the star, planet, and moon, can be adjusted in each simulation. It is possible to simulate as many successive transits as desired. Since the presence of spots on the surface of the star may produce a signal similar to that of the presence of a moon, our model also allows for the inclusion of starspots. The goal is to determine the criteria for detectability of moons using photometry with the CoRoT and Kepler telescopes taking into account the stellar activity.
Planetary Survival and Ejection in Transient Multiple Star Systems
Authors: Meng Zeyang , Xie Ji-Wei , Zhou Ji-Lin
Published: April 2014

Many planets have been detected in close binary stars with separation only ~20 AU. These discoveries challenge the current theory of planet formation because binary stars with such an close separation are thought to have strong perturbations and thus inhibit planet formation around them. To address this issue, another scenario had been suggested: the binary separation was wider enough for binary formation in early stages, but it shrank to the present one after a transient triple star phase (stellar scattering phase). Here, we investigate how could planet survive or be ejected under this scenario. We find that (1) the odds of planetary survival are significantly reduced if scatterings between planets and/or planetesimals are included (2) circumbinary planets/planetesimals could be readily formed during such a transient phase.
Classification Photometry for Ten dM Planet Hosts
Authors: Wing Robert F.
Published: April 2014

Spectral classifications and color temperatures based on narrow-band TiO/CN photometry are given for ten dM stars that are known to be planet hosts.
Shaping of the Inner Solar System by the Gas-Driven Migration of Jupiter
Authors: Walsh Kevin J. , Morbidelli Alessando , Raymond Sean N. , O'Brien David P. , Mandell Avi M.
Published: April 2014

A persistent difficulty in terrestrial planet formation models is creating Mars analogs with the appropriate mass: Mars is typically an order of magnitude too large in simulations. Some recent work found that a small Mars can be created if the planetesimal disk from which the planets form has an outermost edge at 1.0 AU. However, that work and no previous work could produce a truncation of the planetesimal disk while also explaining the mass and structure of the asteroid belt. We show that gas-driven migration of Jupiter inward to 1.5 AU, before its subsequent outward migration, can truncate the disk and repopulate the asteroid belt. This dramatic migration history of Jupiter suggests that the dynamical behavior of our giant planets was more similar to that inferred for extra-solar planets than previously thought, as both have been characterised by substantial radial migration.
Main-Belt Comets as Tracers of Ice in the Inner Solar System
Authors: Hsieh Henry H.
Published: April 2014

As a recently recognized class of objects exhibiting apparently cometary (sublimation-driven) activity yet orbiting completely within the main asteroid belt, main-belt comets (MBCs) have revealed the existence of present-day ice in small bodies in the inner solar system and offer an opportunity to better understand the thermal and compositional history of our solar system, and by extension, those of other planetary systems as well. Achieving these overall goals, however, will require meeting various intermediate research objectives, including discovering many more MBCs than the currently known seven objects in order to ascertain the population's true abundance and distribution, confirming that water ice sublimation is in fact the driver of activity in these objects, and improving our understanding of the physical, dynamical, and thermal evolutionary processes that have acted on this population over the age of the solar system.
Planetesimal Formation in Zonal Flows Arising in Magneto-Rotationally-Unstable Protoplanetary Disks
Authors: Dittrich Karsten , Klahr Hubert , Johansen Anders
Published: April 2014

Recent simulations show long -lived sub- and super-Keplerian flows in protoplanetary disks. These so-called zonal flows are found in local as well as global simulations of magneto-rotationally unstable disks. We investigate the strength and life-time of the resulting long-lived gas over- and under-densities as well as particle concentrations function of the azimuthal and radial size of the local shearing box. Changes in the azimuthal extent do not affect the zonal flow features. However, strength and life-time of zonal flows increase with increasing radial box sizes. Our simulations show indications, and support earlier results, that zonal flows have a natural length scale of approximately 5 pressure scale heights. For the first time, the reaction of dust particles in boxes with zonal flows are studied. We show that particles of some centimeters in size reach a hundred-fold higher density than initially, without any self-gravitating forces acting on the point masses. We further investigate collision velocities of dust grains in a turbulent medium.
Giant Impacts and Debris Disks
Authors: Genda H. , Kobayashi H. , Kokubo E.
Published: April 2014

During the last stage of terrestrial planet formation, Mars-sized protoplanets often collides with each other. Our high-resolution impact simulations show that such giant impacts produce a significant amount of fragments within the terrestrial planet region. These ejected fragments form a hot debris disk around the central star. We calculated the evolution of the surface density and size distribution of the debris disk using the analytical model of collision disruption, and estimated its infrared excess emission. We found that 24 μm flux from the debris disk is higher than stellar flux throughout the giant impact stage (~ 108 years), which can explain the infrared excess recently observed around the star with the age of 107 – 108 years.
Spectral Energy Distributions of Fragmenting Protostellar Disks
Authors: Zakhozhay Olga , Vorobyov Eduard I.
Published: April 2014

In this article we show that massive and hot fragments forming in protostellar disks can leave characteristic signatures in spectral energy distributions (SEDs) of young stellar objects. This occurs when the fragment evaporates dust in its atmosphere, which results in a sharp drop in opacity and subsequent rise in the surface temperature of the fragment. These hot fragments can produce local maxima in the SEDs at 5–10 μm.
The Azimuthal Distribution of Dust Particles in an Eccentric Protoplanetary Disk with an Embedded Gas Giant Planet
Authors: Gu Pin-Gao , Hsieh He-Feng
Published: April 2014

We investigate the dust velocity and spatial distribution in an eccentric protoplanetary disk under the secular gravitational perturbation of an embedded planet of about 5 Jupiter masses. We first employ the FARGO code to obtain the two-dimensional density and velocity profiles of the gas disk with the embedded planet in the quasi-steady state. We then apply the secular perturbation theory and incorporate the gas drag to estimate the dust velocity on the secular timescale. The dust-to-gas ratio of the unperturbed disk is simply assumed to be 0.01. In our fiducial disk model with the planet at 5 AU, we find that for 0.01 cm– to 1 m–sized dust particles well coupled to the gas, the dust behaves similarly to the gas and exhibits non-axisymmetric dynamics as a result of eccentric orbits. However, for the case of a low-density gaseous disk (termed “transition disk” henceforth in this article) harboring the planet at 100 AU, the azimuthal distributions of dust of various sizes can deviate significantly.
Diversity of Planetary Atmospheric Circulations and Climates in a Simplified General Circulation Model
Authors: Wang Yixiong , Read Peter
Published: April 2014

The parametric dependence of terrestrial planetary atmospheric circulations and climates on characteristic parameters is studied. A simplified general circulation model—PUMA is employed to investigate the dynamic effects of planetary rotation rate and equator-to-pole temperature difference on the circulation and climate of terrestrial planetary atmospheres. Five different types of circulation regime are identified by mapping the experimental results in a 2-D parameter space defined by thermal Rossby number and frictional Taylor number. The effect of the transfer and redistribution of radiative energy is studied by building up a new two-band semi-gray radiative-convective scheme, which is capable of modelling greenhouse and anti-greenhouse effects while keeping the tunable parameters as few as possible. The results will provide insights into predicting the habitability of terrestrial exoplanets.
Reconstructing the Stellar UV and EUV Emission that Controls the Chemistry of Exoplanet Atmospheres
Authors: Linsky Jeffrey L. , France Kevin , Ayres Tom
Published: April 2014

Lyman-α and extreme-ultraviolet radiation from exoplanet host stars are critically important for evaluating the phototchemistry of planetary atmospheres, but these emissions are largely or completely absorbed by hydrogen in the interstellar medium. We describe a new technique for estimating the intrinsic Lyman-α and EUV fluxes of F, G, K, and M stars using correlations with observable emission lines.
On the Current State of Ground-based Transmission Spectroscopy of Planet Atmospheres
Authors: Nortmann Lisa , Dreizler Stefan , Bean Jacob
Published: April 2014

In response to the large number of exoplanet detections, the characterization of these planets has become a major focus of exoplanet science. Transiting planets are of particular interest as they allow us to investigate the transmission of their atmospheres. Our group uses ground-based facilities like the ESO/VLT to probe the atmosphere of hot Jupiters with the technique of spectrophotometry. In our preliminary results for the hot Jupiters WASP-17b and WASP-31b we find the reachable precision to be limited by instrumental systematic noise rather than photon noise. We discuss the source of the noise and suggest two approaches to correct it.
Re-Evaluation of the Inner Edge of Habitable Zone
Authors: Kodama Takanori , Genda Hidenori , Abe Yutaka , Zahnle Kevin
Published: April 2014

Existence of liquid water on the planetary surface is thought to be an important condition for the origin and evolution of life. Planets with oceans (or lakes) are classified in two types: Earth-like ‘aqua planets’ and less water ‘land planets’. The latter shows stronger resistance than the former to the runaway greenhouse caused by the increase of stellar luminosity. We examined the possibility of evolution from an aqua planet to a land planet by water loss. We showed that an aqua planet with less than about 0.1 present Earth's ocean mass can evolve to a land planet without having experience of the runaway greenhouse, and maintains liquid water on its surface for about 2Gyrs longer than planets with larger amount of water. Our results mean that the initial amount of water is important for their evolution paths and habitability.
Variations and Effects of the Venusian Bow Shock from VEX Mission
Authors: Xue Yansong , Jin Shuanggen
Published: April 2014

The upper atmosphere of Venus is not shielded by planetary magnetic field from direct interaction with the solar wind. The interaction of shocked solar wind and the ionosphere results in ionopause. Magnetic barrier, the inner region of dayside magnetosheath with the dominated magnetic pressure deflects the solar wind instead of the ionopause at solar maximum. Therefore, the structure and interaction of venusian ionosphere is very complex. Although the Venus Express (VEX) arrived at Venus in April 2006 provides more knowledge on the Venusian ionosphere and plasma environment, compared to Pioneer Venus Orbiter (PVO) with about 14 years of observations, some important details are still unknown (e.g., long Venusian bow shock variations and effects). In this paper, the bow shock positions of Venus are determined and analyzed from magnetometer (MAG) and ASPERA-4 of the Venus Express mission from May 28, 2006 to August 17, 2010. Results show that the altitude of BS was mainly affected by SZA (solar zenith angle) and Venus bow shocks inbound and outbound are asymmetry.
Habitable Planets: Interior Dynamics and Long-Term Evolution
Authors: Tackley Paul J. , Ammann Michael M. , Brodholt John P. , Dobson David P. , Valencia Diana
Published: April 2014

Here, the state of our knowledge regarding the interior dynamics and evolution of habitable terrestrial planets including Earth and super-Earths is reviewed, and illustrated using state-of-the-art numerical models. Convection of the rocky mantle is the key process that drives the evolution of the interior: it causes plate tectonics, controls heat loss from the metallic core (which generates the magnetic field) and drives long-term volatile cycling between the atmosphere/ocean and interior. Geoscientists have been studying the dynamics and evolution of Earth's interior since the discovery of plate tectonics in the late 1960s and on many topics our understanding is very good, yet many first-order questions remain. It is commonly thought that plate tectonics is necessary for planetary habitability because of its role in long-term volatile cycles that regulate the surface environment. Plate tectonics is the surface manifestation of convection in the 2900-km deep rocky mantle, yet exactly how plate tectonics arises is still quite uncertain; other terrestrial planets like Venus and Mars instead have a stagnant lithosphere- essentially a single plate covering the entire planet. Nevertheless, simple scalings as well as more complex models indicate that plate tectonics should be easier on larger planets (super-Earths), other things being equal. The dynamics of terrestrial planets, both their surface tectonics and deep mantle dynamics, change over billions of years as a planet cools. Partial melting is a key process influencing solid planet evolution. Due to the very high pressure inside super-Earths' mantles the viscosity would normally be expected to be very high, as is also indicated by our density function theory (DFT) calculations. Feedback between internal heating, temperature and viscosity leads to a superadiabatic temperature profile and self-regulation of the mantle viscosity such that sluggish convection still occurs.
Transforming Gas Giant Planets into Smaller Objects Through Tidal Disruption
Authors: Liu Shang-Fei , Guillochon James , Lin Douglas N. C. , Ramirez-Ruiz Enrico
Published: April 2014

Recent observations have revealed several Jupiter-mass planets with highly eccentric and / or misaligned orbits, which clearly suggests that dynamical processes operated in these systems. These dynamical processes may result in close encounters between Jupiter-like planets and their host stars. Using three-dimensional hydrodynamical simulations, we find that planets with cores are more likely to be retained by their host stars in contrast with previous studies which suggested that coreless planets are often ejected. We propose that after a long term evolution some gas giant planets could be transformed into super-Earths or Neptune-like planets, which is supported by our adiabatic evolution models. Finally, we analyze the orbits and structure of known planets and Kepler candidates and find that our model is capable of producing some of the shortest-period objects.
Stellar Variabilities: Challenges for the Detection and Characterization of Exoplanets
Authors: Boisse I. , Dumusque X. , Santos N. C. , Oshagh M. , Bonfils X. , Montalto M. , Boué G. , Lovis C.
Published: April 2014

The photometric and RV techniques, although extremely efficient to detect and characterize planets, are, however, indirect techniques (as well as astrometry). Phenomena such as stellar pulsation, inhomogeneous convection, spots or magnetic cycles can prevent us from finding planets or they might degrade the parameters estimation. We will consider the challenges related to the knowledge of stellar activity for the next decade: detect telluric planets in the habitable zone of their stars (from G to M dwarfs), understand the activity in the low-mass end of M dwarf (on which will focus future near-infrared high-resolution spectrograph like SPIRou or CARMENES), limitation to the process of summing several transit observations (in order to characterize the atmospheric components) due to the variability of stellar activity (from the ground or with Spitzer or JWST), as well as the methods proposed and used to overcome this issue.
A Fiber Coupling Plug for Multi-Object Exoplanet Search Spectral Interferometer
Authors: Zhang Kai , Zhu Yongtian , Yue Zhongyu , Wang Lei
Published: April 2014

The increasing number of spectral survey telescopes that are soon commissioned for exploring the universe will confront us with many new challenges on the use of optical fibers. A fiber-switching problem for telescope's terminal instrument is as important as a well-known problem of positioning fibers on telescope's focal plane. For a modern survey telescope, it generally feeds several terminal instruments with different functions. According to the observation, these instruments are seriously in need of switching fiber-link with telescope as soon as possible. A kind of multi-fiber coupling plugs introduced in this paper will work for switching fiber-link between Multi-object Exoplanet Search Spectral Interferometer (MESSI) and low resolution spectrograph at Guoshoujing telescope (LAMOST). It includes an inserter, a receptor and a socket in general. The number of simultaneously coupling fibers is up to 25 per group, and any broken fiber in a single plug can be replaced by a new standard one soon without wasting entire fiber bundle. In addition, Most of mechanical part can also be individually replaced when a normal loss happens after a long working time. The related test result is given in detail, including the machining precision and coupling efficiency.
Single Mode, Extreme Precision Doppler Spectrographs
Authors: Schwab Christian , Leon-Saval Sergio G. , Betters Christopher H. , Bland-Hawthorn Joss , Mahadevan Suvrath
Published: April 2014

The ‘holy grail’ of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.
Absolute Proper Motions Outside the Plane (APOP)
Authors: Qi Zhaoxiang , Yu Yong , Smart Richard L. , Lattanzi Mario G. , Tang Zhenghong , Bucciarelli Beatrice , Vecchiato Alberto , Spagna Alessandro , McLean Brian J.
Published: April 2014

Most of the discovered exoplanets are close to our sun. Usually their host star is with large proper motions, which is an important parameter for exoplanet searching. The first version of absolute proper motions catalog achieved based on Digitized Sky Survey Schmidt plate where outside the galactic plane |b|≥27° is presented, resulting in a zero point error less than ± 0.3 mas/yr, and the overall accuracy better than ± 4.5 mas/yr for objects brighter than RF=18.5, and ranging from 4.5 to 9.0 mas/yr for objects with magnitude 18.5<RF<20.5. The systematic errors of absolute proper motions related to the position, magnitude and color are practically all removed. The sky cover of this catalog is 22,525 degree2, the mean density is 6444 objects/degree2 and the magnitude limit is around RF=20.5.
Null Stellar Intensity Interferometry
Authors: Tan P. K. , Chia C. M. , Han W. D. , Chan A. H. , Kurtsiefer C.
Published: April 2014

Since the discovery of the first exoplanet in 1989, though over 850 candidates have been verified (Schneider 2012), few are similar to our Earth in terms of mass and size. Hence here we would like to propose the revival and improvement of optical intensity interferometry to achieve sub-milliarcsecond resolution, which promises also to be less sensitive to weather conditions, light pollution and optomechanical alignments, yet only requiring baselines <100m.
Occultation Spectrophotometry of Extrasolar Planets with SOFIA
Authors: Angerhausen Daniel , Huber Klaus F. , Mandell Avi M. , McElwain Michael W. , Czesla Stefan , Madhusudhan Nikku , Morse Jon A.
Published: April 2014

The NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA), a 2.5-meter infrared telescope on board a Boeing 747-SP, will conduct 0.3 - 1,600 μm photometric, spectroscopic, and imaging observations from altitudes as high as 45,000 ft., where the average atmospheric transmission is greater than 80 percent. SOFIA's first light cameras and spectrometers, as well as future generations of instruments, will make important contributions to the characterization of the physical properties of exoplanets. Our analysis shows that optical and near-infrared photometric and spectrophotometric follow-up observations during planetary transits and eclipses will be feasible with SOFIA's instrumentation, in particular the HIPO-FLITECAM optical/NIR instruments. The airborne-based platform has unique advantages in comparison to ground- and space-based observatories in this field of research which we will outline here. Furthermore we will present two exemplary science cases, that will be conducted in SOFIA's cycle 1.
Direct Detection of Nearby Habitable Zone Planets Using Slicer Based Integral Field Spectrographs and EPICS on the E-ELT
Authors: Salter Graeme S. , Thatte Niranjan A. , Tecza Matthias , Clarke Fraser , Kasper Markus E.
Published: April 2014

Early design studies for the future Exo-Planet Imaging Camera and Specrotgraph (EPICS) on the European Extremely Large Telescope (E-ELT) show the ability to probe the region of super-Earths in the habitable zone of stars within 5pc (including Gilese 581d). However, these planets will be lost to us if the correct choice of integral field spectrograph (IFS) technology is not selected for such an instrument the ability to fit and remove the speckle noise that remains is crucial to reaching these contrasts.

We conclusively demonstrate, though the use of an experimental setup producing an artificial speckle, that slicer based IFSs and post-processing using spectral deconvolution can achieve speckle rejection factors exceeding 103. Contrary to popular belief, we do not find any evidence that this choice of IFS technology limits the achievable contrast. Coupled with extreme adaptive optics and high performance coronographs, a slicer based integral field spectrograph could achieve contrasts exceeding 109, enabling these super-Earths to be detected in the habitable zone of nearby stars, making it an attractive option for the next generation of instruments being designed for the direct detection of extra solar planets.
Exoplanet Surveys at Universidad de Chile
Authors: Rojo Patricio , Jenkins James , Hoyer Sergio , Jones Matías
Published: April 2014

We present and highlight the first results of the three main exoplanet surveys we are currently conducting at Universidad de Chile: CHEPS, Red Giant Exoplanets (radial velocity), and TraMoS (transit lightcurves). We have several interesting candidates at the Calan-Hertfordshire Extrasolar Planet Search (CHEPS) project, which is aimed at searching for the currently missing southern bright transiting planets at a few m/s radial velocity precision. Using the same technique, we are also characterizing the planetary population in a constrained sample of Red Giant stars. The Transit Monitoring from the South (TraMoS) project is aimed both at improving transit parameters and at detecting any kind of lightcurve variability from several known southern exoplanet systems.
CD154+ CD4+ T‐cell dependence for effective memory influenza virus‐specific CD8+ T‐cell responses
Authors: Olson Matthew R , Seah Shirley GK , Edenborough Kathryn , Doherty Peter C , Lew Andrew M , Turner Stephen J
Published: April 2014

CD40–CD154 (CD40 ligand) interactions are essential for the efficient priming of CD8+ cytotoxic T lymphocyte (CTL) responses. This is typically via CD4+CD154+ T‐cell‐dependent ‘licensing’ of CD40+ dendritic cells (DCs); however, DCs infected with influenza A virus (IAV) upregulate CD154 expression, thus enabling efficient CTL priming in the absence of CD4+ T activation. Therefore, it is unclear whether CD4 T cells and DCs have redundant or unique roles in the priming of primary and secondary CTL responses after infection. Here we determine the precise cellular interactions involved in CD40–CD154 regulation of both primary and secondary IAV‐specific CTL responses. Infection of both CD40 KO and CD154 KO mice resulted in diminished quantitative and qualitative CTL responses after both primary and secondary infection. Adoptive transfer of CD154+, but not CD154 KO, CD4 T cells into CD154 KO mice restored both primary and secondary IAV‐specific CD8 T‐cell responses. These data show that, although CD154 expression on CD4 T cells and other cell types (that is, DCs) may be redundant for the priming of primary CTL responses, CD154 expression by CD4 T cells is required for the priming memory CD8 T cells that are capable of fully responding to secondary infection.
The influence of hypoxia on the differentiation capacities and immunosuppressive properties of clonal mouse mesenchymal stromal cell lines
Authors: Prado‐Lòpez Sonia , Duffy Michelle M , Baustian Claas , Alagesan Senthilkumar , Hanley Shirley A , Stocca Alessia , Griffin Matthew D , Ceredig Rhodri
Published: April 2014

Multipotent mesenchymal stromal cells are multipotent cells capable of differentiating into different mesodermal cell types. Enigmatically, mesenchymal stromal cells present in the bone marrow support early lymphopoiesis yet can inhibit mature lymphocyte growth. Critical features of the bone marrow microenvironment, such as the level of oxygen, play an important role in mesenchymal stromal cell biology. Herein, we show that a panel of continuously growing mouse mesenchymal stromal cell lines, namely OP9, MS5, PA6, ST2 and B16‐14, exhibit mesenchymal stromal cell characteristic phenotypes and respond physiologically to oxygen deprivation. Culturing freshly isolated bone marrow‐derived mesenchymal stromal cells or cell lines at 5% O2 resulted in a dramatic increase in expression of hypoxia‐inducible factor family members and of key genes involved in their differentiation. Phenotypically, their osteogenic and adipogenic differentiation capacity was generally improved in hypoxia, whereas their inhibitory effects on in vitro T‐cell proliferation were preserved. Taken together, we conclude that these continuously growing mouse cell lines behave as canonical mesenchymal stromal cells and respond physiologically to hypoxia, thereby providing a potent tool for the study of different aspects of mesenchymal stromal cell biology.
Suppressive action of acetate on interleukin‐8 production via tubulin‐α acetylation
Authors: Ishiguro Kazuhiro , Ando Takafumi , Maeda Osamu , Watanabe Osamu , Goto Hidemi
Published: April 2014

Acetate is the major short‐chain fatty acid produced by commensal bacteria in the gut and is known as a nutrient source for epithelial cells of the mucosa. Acetate also suppresses interleukin (IL)‐2 production in T cells by inhibiting nuclear factor of activated T cells (NFAT) nuclear translocation via tubulin‐α acetylation. Using acetylation of tubulin‐α as a biomarker, we have examined the influence of acetate in the large intestine. Because of high concentrations of acetate in fecal material, tubulin‐α acetylation is dominant in the proximal large intestine relative to other sections of the large intestine and is induced in epithelial cells of the colonic mucosa. Flagellin stimulation induces IL‐8 production in epithelial cells and acetate suppresses this IL‐8 production via tubulin‐α acetylation. Flagellin stimulation activates nuclear factor‐κB, CREB and AP‐1, but not NFAT. Of these transcription factors, acetate specifically inhibits AP‐1 activation. Acetate impairs flagellin‐induced activation of the Rap1‐MEK‐ERK‐Elk‐1 pathway with acetylation of tubulin‐α that is bound to Rap1, resulting in reduced expression of c‐Fos, a subunit of AP‐1. These findings reveal a novel action of acetate via tubulin‐α acetylation in epithelial cells of the colonic mucosa.
Discovery of a SAR11 growth requirement for thiamin’s pyrimidine precursor and its distribution in the Sargasso Sea
Authors: Carini Paul , Campbell Emily O , Morré Jeff , Sañudo-Wilhelmy Sergio A , Cameron Thrash J , Bennett Samuel E , Temperton Ben , Begley Tadhg , Giovannoni Stephen J
Published: April 2014

Vitamin traffic, the production of organic growth factors by some microbial community members and their use by other taxa, is being scrutinized as a potential explanation for the variation and highly connected behavior observed in ocean plankton by community network analysis. Thiamin (vitamin B1), a cofactor in many essential biochemical reactions that modify carbon–carbon bonds of organic compounds, is distributed in complex patterns at subpicomolar concentrations in the marine surface layer (0–300 m). Sequenced genomes from organisms belonging to the abundant and ubiquitous SAR11 clade of marine chemoheterotrophic bacteria contain genes coding for a complete thiamin biosynthetic pathway, except for thiC, encoding the 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) synthase, which is required for de novo synthesis of thiamin’s pyrimidine moiety. Here we demonstrate that the SAR11 isolate ‘Candidatus Pelagibacter ubique’, strain HTCC1062, is auxotrophic for the thiamin precursor HMP, and cannot use exogenous thiamin for growth. In culture, strain HTCC1062 required 0.7 zeptomoles per cell (ca. 400 HMP molecules per cell). Measurements of dissolved HMP in the Sargasso Sea surface layer showed that HMP ranged from undetectable (detection limit: 2.4 pm) to 35.7 pm, with maximum concentrations coincident with the deep chlorophyll maximum. In culture, some marine cyanobacteria, microalgae and bacteria exuded HMP, and in the Western Sargasso Sea, HMP profiles changed between the morning and evening, suggesting a dynamic biological flux from producers to consumers.