Investigating the Relationship between Environment and Active Galactic Nuclei activity at High Redshift

This thesis presents an investigation into the relationship between large-scale structure environment and Active Galactic Nuclei (AGN) activity at high redshift. To accomplish this, the environments of AGN are studied from two complementary perspectives. Firstly, various observations of a specific large-scale structure at z = 2.3 are used to assess the level of AGN activity in relation to the field. The main result of this study is that both the emission-line and X-ray selected AGN populations are significantly enhanced; X-ray detected Lyman Alpha Emitters (LAEs), however, are not found to be significantly enhanced. The host galaxy properties of z ~ 1 X-ray sources are then derived and studied in detail. Confirming previous results, X-ray sources are found in optically luminous (MB ~< −20.5mag), massive (log(M∗/ M⊙) ≥ 10.5) red and blue hosts. A larger fraction of red/green hosts harbour obscured (log(NH) ≥ 22) AGN than blue, with the most obscured sources (log(NH) ≥ 23.5) also being more frequently found in red/green host galaxies than blue. The second approach used the 3rd-nearest neighbour measure to study the environment of X-ray hosts at z ~ 1, accounting for their optical colour, luminosity and stellar mass. A main new and important result is that X-ray hosts are found in regions of enhanced density compared to optical galaxies of equivalent mass, which is not due to the observed colour-density relation at z ~ 1. The enhancement is found to be most significant at the reddest colours, brightest luminosities, and highest stellar masses. The results from this thesis show that the dense environments probed in this work generally promote AGN activity. This is probably not due to major mergers, but could be due to an increased probability of minor mergers/interactions and/or milder environmental processes triggering nuclear activity. Alternatively, perhaps there is some other galaxy property (e.g., residing in higher mass haloes) which is conducive to AGN activity

Astrometry and Exoplanets: the Gaia Era, and Beyond

The wealth of information in the Gaia catalogue of exoplanets will constitute a fundamental contribution to several hot topics of the astrophysics of planetary systems. I briefly review the potential impact of Gaia micro-arsec astrometry in several areas of exoplanet science, discuss what key follow-up observations might be required as a complement to Gaia data, and shed some light on the role of next generation astrometric facilities in the arena of planetary systems.Comment: 6 pages, 1 figure. Proceedings of the final ELSA Conference 'Gaia: at the frontiers of astrometry', Sevres (France), 7-11 June 2010. To appear in EAS Publication Series, EDP Science

Direct Detection of Galactic Halo Dark Matter

The Milky Way Galaxy contains a large, spherical component which is believed to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this ``dark matter'' may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the Galaxy itself. We conducted a survey to find faint, cool white dwarfs with large space velocities, indicative of their membership in the Galaxy's spherical halo component. The survey reveals a substantial, directly observed population of old white dwarfs, too faint to be seen in previous surveys. This newly discovered population accounts for at least 2% of the halo dark matter. It provides a natural explanation for the indirect observations, and represents a direct detection of Galactic halo dark matter.Comment: 13 pages, 4 figures, 1 table. Note added after Science Express online publication: This text reflects the correction of a few typographical errors in the online version of the table. It also includes the new constraint on the calculation of d_max which accounts for the fact that the survey could not have detected stars with proper motions below 0.33 arcseconds per year. Published online at ScienceExpress www.sciencemag.org 22 March 2001; 10.1126/science.1059954; To appear in Science 27 April 200

Optimising Community-Based Forest Management Policy in Indonesia: a Critical Review

Community-based forest management (CBFM) is a popular concept in many countries, covering over 400 million hectares worldwide. In Indonesia, CBFM is viewed as an important component of the forestry sector with the government's goal to establish 5.6 million hectares of CBFM by 2011 (twice the area of industrial plantation forests). The Indonesian government is pursuing CBFM as a strategy to reduce deforestation of tropical forests, to alleviate poverty in rural communities, and to contribute timber supplies to the processing industry.There has been a belief that CBFM can lead to a physical and socio-economic transformation at the local level. However, in practice, especially in Indonesia, this claim appears problematic because in over 35 years since it has been officially introduced it does not appear to have contributed significantly to address the problems of deforestation and rural poverty.Despite the government's ambitious goal for CBFM, there are several challenges, for instance the entrenched poverty of many rural communities and inconsistent and unsupportive policies of CBFM at the national, provincial, and local government. This paper is intended to explore, discusses, and criticize the implementation of CBFM policies in various countries and in particular in Indonesia. This paper also aims to explore its challenges in the future development in Indonesia

Communicating REDD+ Issues at Local Level: Creating Latent and Manifest Conflict

”Carbon offsetting”in forestry-related projects is widely regarded as the ideal solution to the three challenges of the 21st Century: climate change, biodiversity conservation andsocio-economic development. At the same time, there is scepticism about the Reducing Emissions from Deforestation and Forest Degradation (REDD) proposal particularly because of the weak governance and institutional capacities in many developing countries, which could jeopardize the delivery of benefits at the local level. One major problem is that most people have little knowledge on the causes and consequences of the climate change. This is partly because the information is largely scattered among scientific journals, and obscured by jargon and sophisticated mathematical models. Consequently, REDD+ is beyond thereach of manyof the people affected by REDD+. This paper examines the efforts and the capacity of the local governments and other development agents in explaining the REDD + issues and its impacts on the local people, especially customary communities. The research shows that lack of policy communication and promotion, as well as consultations with the affected groups arethe main contributing factors to latent and manifest conflicts. In turn, this conflicth as proven that NGOs, district governments and scientists have not been successful intermediaries. Thus, in the future policy communication on REDD+ should beaimed at improved network formation (i.e. between farmer groups with business partners and NGOs and other related actors), learning, negotiation and relationship building (i.e. between members of farmer groups, not only withtheir leaders within the farmer groups but also with governmental and business sectors). Policy communication should also create a new configuration of support and services in form of advocacy, empowerment and management skills and technical skills for conserving their natural resources, for adaptation to climate change and building more equitable governance and transparency at local level

"Hero Imagery" - Are there performance advantages associated with imagining yourself as your favourite athlete?

Objectives: This study examined whether there are performance advantages associated with a single bout of imagery when imagining yourself ‘as your favourite athlete’, or imagining yourself performing a strength-based task. Design: A blind 2 (Imagery ability: high, low) x 3 (imagery condition: self, “hero”, control) mixed factorial design was used. Methods: Participants (n = 17 male; Mage = 19.7 ± 2.7) completed the Sport Imagery Ability Questionnaire then viewed a standardised video demonstrating the grip strength (GS) task. Three baseline trials separated by one minute were then executed. Three imagery scripts (control, self, hero) were then presented to participants via an MP3 player in a counterbalanced order (an interval of 1-minute was provided between each condition). The conclusion of each imagery script prompted participants to perform the GS task. Performance in each condition was conceptualised as delta change scores (Imagery condition – baseline average). Results: No main effects were present but there was a group x condition interaction (F(2,28) = 4.27, p = .02. ƞ_p^2= .23. The interaction suggests that for individuals with high imagery ability, simply “doing the imagery that they already do” is preferable compared to a scripted self- or hero-imagery condition. For individuals with a low imagery ability, a simple script whether that is self- or hero- based may enhance strength performance, compared to “what they already do”. Conclusion: Imagery ability may influence the effectiveness of a brief imagery intervention. Further examination of processes and outcomes associated with “hero-imagery” is recommended