32 research outputs found
Compiling results from various research projects â can we compare apples to oranges? [Poster abstract]
Growth curve of female collared peccaries (Pecari tajacu) raised in captivity in the Brazilian Amazon Region
Soft methods, hard targets: regional alcohol managers as a policy network
Regional Alcohol Managers (RAMs) was employed in the nine English health regions over 2008â2011. Their mission was to impact on the âhard targetâ of Alcohol-Related Hospital Admissions (AHRAs) through the âsoft methodsâ of persuasion and influence: working with local partners on evidence-based interventions. Drawing on a qualitative evaluation, this article shows how a central government policy imperative (ARHAs) led to âgovernment at a distanceâ responses, including the introduction of RAMs. The processes involved in shaping and delivering this function bore the hallmarks of a complex, interactive policy network model, involving individuals whose bearings and roles were flexible and sometimes ambiguous. While there were overlaps and blurring of boundaries, there were three levels of policy network: central government, regional and local. As the ânetwork in the middleâ, the RAMs were pulled in both directions by conflicting agendas but were also able to have an impact on central and local policy
Palaeolimnological evidence of late-Holocene settlement and abandonment in the Mirador Basin, Peten, Guatemala
Detection and characterisation of 54 massive companions with the SOPHIE spectrograph Seven new brown dwarfs and constraints on the brown dwarf desert
Context. Brown dwarfs (BD) are substellar objects intermediate between planets and stars with masses of ~13â80 MJ. While isolated BDs are most likely produced by gravitational collapse in molecular clouds down to masses of a few MJ, a non-negligible fraction of low-mass companions might be formed through the planet-formation channel in protoplanetary discs. The upper mass limit of objects formed within discs is still observationally unknown, the main reason being the strong dearth of BD companions at orbital periods shorter than 10 yr, also known as the BD desert.
Aims. To address this question, we aim at determining the best statistics of companions within the 10â100 MJ mass regime and located closer than ~10 au to the primary star, while minimising observation and selection bias.
Methods. We made extensive use of the radial velocity (RV) surveys of northern hemisphere FGK stars within 60 pc of the Sun, performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We derived the Keplerian solutions of the RV variations of 54 sources. Public astrometric data of the HIPPARCOS and Gaia missions allowed us to constrain the masses of the companions for most sources. We introduce GASTON, a new method to derive inclination combining RVs and Keplerian and astrometric excess noise from Gaia DR1.
Results. We report the discovery of 12 new BD candidates. For five of them, additional astrometric data led to a revision of their mass in the M-dwarf regime. Among the seven remaining objects, four are confirmed BD companions, and three others are likely also in this mass regime. Moreover, we report the detection of 42 M-dwarfs within the range of 90 MJâ0.52 Mâ. The resulting M sin i-P distribution of BD candidates shows a clear drop in the detection rate below 80-day orbital period. Above that limit, the BD desert appears rather wet, with a uniform distribution of the M sin i. We derive a minimum BD-detection frequency around Solar-like stars of 2.0 ± 0.5%.ISSN:0004-6361ISSN:1432-074