1,688 research outputs found

    Include medical ethics in the Research Excellence Framework

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    The Research Excellence Framework of the Higher Education Funding Council for England is taking place in 2013, its three key elements being outputs (65% of the profile), impact (20%), and “quality of the research environment” (15%). Impact will be assessed using case studies that “may include any social, economic or cultural impact or benefit beyond academia that has taken place during the assessment period.”1 Medical ethics in the UK still does not have its own cognate assessment panel—for example, bioethics or applied ethics—unlike in, for example, Australia. Several researchers in medical ethics have reported to the Institute of Medical Ethics that during the internal preliminary stage of the Research Excellence Framework several medical schools have decided to include only research that entails empirical data gathering. Thus, conceptual papers and ethical analysis will be excluded. The arbitrary exclusion of reasoned discussion of medical ethics issues as a proper subject for medical research unless it is based on empirical data gathering is conceptually mistaken. “Empirical ethics” is, of course, a legitimate component of medical ethics research, but to act as though it is the only legitimate component suggests, at best, a partial understanding of the nature of ethics in general and medical ethics in particular. It also mistakenly places medicine firmly on only one side of the science/humanities “two cultures” divide instead of in its rightful place bridging the divide. Given the emphasis by the General Medical Council on medical ethics in properly preparing “tomorrow’s doctors,” we urge medical schools to find a way of using the upcoming Research Excellence Framework to highlight the expertise residing in their ethicist colleagues. We are confident that appropriate assessment will reveal work of high quality that can be shown to have social and cultural impact and benefit beyond academia, as required by the framework

    Influence du pastoralisme sur les populations acridiennes dans le massif du Siroua (Maroc)

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    Un foyer de grégarisation de #Dociostaurus maroccanus (Thunb.) a été étudié au cours de cinq missions annuelles (1988-1993). Le site d'étude est un pâturage d'altitude dans l'Anti-Atlas (2300 m) où les troupeaux estivent. Sur les 2850 ha de pâturages à #Poa bulbosa le nombre de moutons et de chèvres a été estimé à 7200 têtes (une tête pour 0,4 ha). Les acridiens (18 espèces) et leurs prédateurs (14 espèces d'insectes et oiseaux) sont cantonnés autour d'une prairie de fauche et des cultures irriguées (55 ha). Le site de ponte du criquet marocain est sur un parc à moutons de 2 hectares. La densité moyenne d'oothèques est de 77/m2, dont 37 % sont détruites par des larves de coléoptères (méloïdes) et des larves de diptères. #Falco naumanni Fleicher et #Pyrrhocorax pyrrhocorax docilis Gm. sont les prédateurs de criquets, importants sur le site. Les craves à bec rouge ont été observés déterrant les oothèques pour les manger. Il est connu que les moutons créent les conditions favorables à la grégarisation du criquet marocain. Nous montrons que le strict calendrier des activités pastorales influence aussi la dynamique des populations acridiennes : les éclosions ont lieu en mai dans un milieu non perturbé par les moutons et à l'abri des prédateurs jusqu'à la fenaison. La transhumance le 28 juillet, en pleine saison de ponte, modifie l'espace et les ressources trophiques disponibles. (Résumé d'auteur

    WASP-50b: a hot Jupiter transiting a moderately active solar-type star

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    We report the discovery by the WASP transit survey of a giant planet in a close orbit (0.0295+-0.0009 AU) around a moderately bright (V=11.6, K=10) G9 dwarf (0.89+-0.08 M_sun, 0.84+-0.03 R_sun) in the Southern constellation Eridanus. Thanks to high-precision follow-up photometry and spectroscopy obtained by the telescopes TRAPPIST and Euler, the mass and size of this planet, WASP-50b, are well constrained to 1.47+-0.09 M_jup and 1.15+-0.05 R_jup, respectively. The transit ephemeris is 2455558.6120 (+-0.0002) + N x 1.955096 (+-0.000005) HJD_UTC. The size of the planet is consistent with basic models of irradiated giant planets. The chromospheric activity (log R'_HK = -4.67) and rotational period (P_rot = 16.3+-0.5 days) of the host star suggest an age of 0.8+-0.4 Gy that is discrepant with a stellar-evolution estimate based on the measured stellar parameters (rho_star = 1.48+-0.10 rho_sun, Teff = 5400+-100 K, [Fe/H]= -0.12+-0.08) which favours an age of 7+-3.5 Gy. This discrepancy could be explained by the tidal and magnetic influence of the planet on the star, in good agreement with the observations that stars hosting hot Jupiters tend to show faster rotation and magnetic activity (Pont 2009; Hartman 2010). We measure a stellar inclination of 84 (-31,+6) deg, disfavouring a high stellar obliquity. Thanks to its large irradiation and the relatively small size of its host star, WASP-50b is a good target for occultation spectrophotometry, making it able to constrain the relationship between hot Jupiters' atmospheric thermal profiles and the chromospheric activity of their host stars proposed by Knutson et al. (2010).Comment: 9 pages, 8 figures. Accepted for publication in Astronomy & Astrophysic

    The Spitzer search for the transits of HARPS low-mass planets - II. Null results for 19 planets

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    Short-period super-Earths and Neptunes are now known to be very frequent around solar-type stars. Improving our understanding of these mysterious planets requires the detection of a significant sample of objects suitable for detailed characterization. Searching for the transits of the low-mass planets detected by Doppler surveys is a straightforward way to achieve this goal. Indeed, Doppler surveys target the most nearby main-sequence stars, they regularly detect close-in low-mass planets with significant transit probability, and their radial velocity data constrain strongly the ephemeris of possible transits. In this context, we initiated in 2010 an ambitious Spitzer multi-Cycle transit search project that targeted 25 low-mass planets detected by radial velocity, focusing mainly on the shortest-period planets detected by the HARPS spectrograph. We report here null results for 19 targets of the project. For 16 planets out of 19, a transiting configuration is strongly disfavored or firmly rejected by our data for most planetary compositions. We derive a posterior probability of 83% that none of the probed 19 planets transits (for a prior probability of 22%), which still leaves a significant probability of 17% that at least one of them does transit. Globally, our Spitzer project revealed or confirmed transits for three of its 25 targeted planets, and discarded or disfavored the transiting nature of 20 of them. Our light curves demonstrate for Warm Spitzer excellent photometric precisions: for 14 targets out of 19, we were able to reach standard deviations that were better than 50ppm per 30 min intervals. Combined with its Earth-trailing orbit, which makes it capable of pointing any star in the sky and to monitor it continuously for days, this work confirms Spitzer as an optimal instrument to detect sub-mmag-deep transits on the bright nearby stars targeted by Doppler surveys.Comment: Accepted for publication in Astronomy and Astrophysics. 23 pages, 21 figure

    Ground-based monitoring of comet 67P/Churyumov-Gerasimenko gas activity throughout the <i>Rosetta</i> mission

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    Simultaneously to the ESA Rosetta mission, a world-wide ground-based campaign provided measurements of the large scale activity of comet 67P/Churyumov-Gerasimenko through measurement of optically active gas species and imaging of the overall dust coma. We present more than two years of observations performed with the FORS2 low resolution spectrograph at the VLT, TRAPPIST, and ACAM at the WHT. We focus on the evolution of the CN production, as a tracer of the comet activity. We find that it is asymmetric with respect to perihelion and different from that of the dust. The CN emission is detected for the first time at 1.34 au pre-perihelion and production rates then increase steeply to peak about two weeks after perihelion at (1.00±0.10) ×1025 molecules s−1, while the post-perihelion decrease is more shallow. The evolution of the comet activity is strongly influenced by seasonal effects, with enhanced CN production when the Southern hemisphere is illuminated

    Lupus-TR-3b: A Low-Mass Transiting Hot Jupiter in the Galactic Plane?

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    We present a strong case for a transiting Hot Jupiter planet identified during a single-field transit survey towards the Lupus Galactic plane. The object, Lupus-TR-3b, transits a V=17.4 K1V host star every 3.91405d. Spectroscopy and stellar colors indicate a host star with effective temperature 5000 +/- 150K, with a stellar mass and radius of 0.87 +/- 0.04M_sun and 0.82 +/- 0.05R_sun, respectively. Limb-darkened transit fitting yields a companion radius of 0.89 +/- 0.07R_J and an orbital inclination of 88.3 +1.3/-0.8 deg. Magellan 6.5m MIKE radial velocity measurements reveal a 2.4 sigma K=114 +/- 25m/s sinusoidal variation in phase with the transit ephemeris. The resulting mass is 0.81 +/- 0.18M_J and density 1.4 +/- 0.4g/cm^3. Y-band PANIC image deconvolution reveal a V>=21 red neighbor 0.4'' away which, although highly unlikely, we cannot conclusively rule out as a blended binary with current data. However, blend simulations show that only the most unusual binary system can reproduce our observations. This object is very likely a planet, detected from a highly efficient observational strategy. Lupus-TR-3b constitutes the faintest ground-based detection to date, and one of the lowest mass Hot Jupiters known.Comment: 4 pages, 4 figures, accepted for publication in ApJ

    The GROUSE project II: Detection of the Ks-band secondary eclipse of exoplanet HAT-P-1b

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    Context: Only recently it has become possible to measure the thermal emission from hot-Jupiters at near-Infrared wavelengths using ground-based telescopes, by secondary eclipse observations. This allows the planet flux to be probed around the peak of its spectral energy distribution, which is vital for the understanding of its energy budget. Aims: The aim of the reported work is to measure the eclipse depth of the planet HAT-P-1b at 2.2micron. This planet is an interesting case, since the amount of stellar irradiation it receives falls in between that of the two best studied systems (HD209458 and HD189733), and it has been suggested to have a weak thermal inversion layer. Methods: We have used the LIRIS instrument on the William Herschel Telescope (WHT) to observe the secondary eclipse of HATP-1b in the Ks-band, as part of our Ground-based secondary eclipse (GROUSE) project. The observations were done in staring mode, while significantly defocusing the telescope to avoid saturation on the K=8.4 star. With an average cadence of 2.5 seconds, we collected 6520 frames during one night. Results: The eclipse is detected at the 4sigma level, the measured depth being 0.109+/-0.025%. The uncertainties are dominated by residual systematic effects, as estimated from different reduction/analysis procedures. The measured depth corresponds to a brightness temperature of 2136+150-170K. This brightness temperature is significantly higher than those derived from longer wavelengths, making it difficult to fit all available data points with a plausible atmospheric model. However, it may be that we underestimate the true uncertainties of our measurements, since it is notoriously difficult to assign precise statistical significance to a result when systematic effects are important.Comment: 7 pages, 10 figures, Accepted for publication in A&

    WASP-42 b and WASP-49 b: two new transiting sub-Jupiters

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    We report the discovery of two new transiting planets from the WASP survey. WASP-42 b is a 0.500 +/- 0.035 M_jup planet orbiting a K1 star at a separation of 0.0548 +/- 0.0017 AU with a period of 4.9816872 +/- 7.3 x 10^-6 days. The radius of WASP-42 b is 1.080 +/- 0.057 R_jup while its equilibrium temperature is T_eq = 995 +/- 34 K. We detect some evidence for a small but non-zero eccentricity of e=0.060 +/- 0.013. WASP-49 b is a 0.378 +/- 0.027 M_jup planet around an old G6 star. It has a period of 2.7817387 +/- 5.6 x 10^-6 days and a separation of 0.0379 +/- 0.0011 AU. This planet is slightly bloated, having a radius of 1.115 +/- 0.047 R_jup and an equilibrium temperature of T_eq = 1369 +/- 39 K. Both planets have been followed up photometrically, and in total we have obtained 5 full and one partial transit light curves of WASP-42 and 4 full and one partial light curves of WASP-49 using the Euler-Swiss, TRAPPIST and Faulkes South telescopes

    Structure and evolution of super-Earth to super-Jupiter exoplanets: I. heavy element enrichment in the interior

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    We examine the uncertainties in current planetary models and we quantify their impact on the planet cooling histories and mass-radius relationships. These uncertainties include (i) the differences between the various equations of state used to characterize the heavy material thermodynamical properties, (ii) the distribution of heavy elements within planetary interiors, (iii) their chemical composition and (iv) their thermal contribution to the planet evolution. Our models, which include a gaseous H/He envelope, are compared with models of solid, gasless Earth-like planets in order to examine the impact of a gaseous envelope on the cooling and the resulting radius. We find that for a fraction of heavy material larger than 20% of the planet mass, the distribution of the heavy elements in the planet's interior affects substantially the evolution and thus the radius at a given age. For planets with large core mass fractions (\simgr 50%), such as the Neptune-mass transiting planet GJ436b, the contribution of the gravitational and thermal energy from the core to the planet cooling history is not negligible, yielding a \sim 10% effect on the radius after 1 Gyr. We show that the present mass and radius determinations of the massive planet Hat-P-2b require at least 200 \mearth of heavy material in the interior, at the edge of what is currently predicted by the core-accretion model for planet formation. We show that if planets as massive as \sim 25 \mjup can form, as predicted by improved core-accretion models, deuterium is able to burn in the H/He layers above the core, even for core masses as large as \sim 100 \mearth. We provide extensive grids of planetary evolution models from 10 \mearth to 10 MJup_{\rm Jup}, with various fractions of heavy elements.Comment: 20 pages, 12 figures. Accepted for publication in Astronomy and Astrophysic

    Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1

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    One aim of modern astronomy is to detect temperate, Earth-like exoplanets that are well suited for atmospheric characterization. Recently, three Earth-sized planets were detected that transit (that is, pass in front of) a star with a mass just eight per cent that of the Sun, located 12 parsecs away. The transiting configuration of these planets, combined with the Jupiter-like size of their host star—named TRAPPIST-1—makes possible in-depth studies of their atmospheric properties with present-day and future astronomical facilities. Here we report the results of a photometric monitoring campaign of that star from the ground and space. Our observations reveal that at least seven planets with sizes and masses similar to those of Earth revolve around TRAPPIST-1. The six inner planets form a near-resonant chain, such that their orbital periods (1.51, 2.42, 4.04, 6.06, 9.1 and 12.35 days) are near-ratios of small integers. This architecture suggests that the planets formed farther from the star and migrated inwards. Moreover, the seven planets have equilibrium temperatures low enough to make possible the presence of liquid water on their surfaces
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