The level and nature of sustainability for clusters of abandoned limestone quarries in the southern Palestinian West Bank

The question of how sustainable a mining site is at the end of its operational life has been somewhat unanswered. The fundamental problem has been how to evaluate the sustainability of a mining site once operations cease and is abandoned. Environmental Impact Assessment (EIA) is certainly a way to evaluate sustainability of such sites, but only through inference and subjective evaluation. This is because the topic of sustainability still hotly debated, and is predominantly focussed on an anthropocentric approach. Even with quantitative-based EIAs, the question is how to directly evaluate sustainability from the data available using a consistent quantitative approach rather than on a case-by-case basis or subjective evaluation.However, by using the ideas and concepts concerning the coupled relationship between the environment and humans prevalent in sustainability science, the question of what is and how to evaluate sustainability has become capable of being answered. Based on previous work of the author in the development and application of a mathematical model of sustainability, the paper applies the model to the results of a quantitative EIA evaluation for nine clusters of abandoned limestone quarries located in the southern Palestinian West Bank.The results indicate that seven of the nine clusters were deemed to be unsustainable, whilst the other two clusters were considered as sustainable at a very weak level only. The results are discussed within the broader context of the coupled environment-human system using one of the supporting frameworks for the development and application of the mathematical model of sustainability: Earth System Analysis. Within this context, the discussion indicates the fact that unmanaged impacts by humans has created the situation for unsustainability to occur. The paper therefore provides for the clearest indication yet of the nature of sustainability at the end of the mining operational life-cycle without an effective and proper management strategy or policies.     

Field optimization and CCD data simulation for the antarctic International Concordia Explorer Telescope (ICE‐T)

We performed extensive data simulations for the planned ultra‐wide‐field, high‐precision photometric telescope ICE‐T (International Concordia Explorer Telescope). ICE‐T consists of two 60 cm‐aperture Schmidt telescopes with a joint field of view simultaneously in two photometric bandpasses. Two CCD cameras, each with a single 10.3k × 10.3k thinned back‐illuminated device, would image a sky field of 65 square degrees. Given a location of the telescope at Dome C on the East Antarctic Plateau, we searched for the star fields that best exploit the technical capabilities of the instrument and the site. We considered the effects of diurnal air mass and refraction variations, solar and lunar interference, interstellar absorption, overexposing of bright stars and ghosts, crowding by background stars, and the ratio of dwarf to giant stars in the field. Using NOMAD, SSA, Tycho‐2 and 2MASS‐based stellar positions and BVIJH magnitudes for these fields, we simulated the effects of the telescope's point‐spread‐function, the integration, and the co‐addition times. Simulations of transit light curves are presented for the selected star fields and convolved with the expected instrumental characteristics. For the brightest stars, we showed that ICE‐T should be capable of detecting a 2 R_Earth Super Earth around a G2 solar‐type star, as well as an Earth around an M0‐star – if these targets were as abundant as hot Jupiters. Simultaneously, the telescope would monitor the host star's surface activity in an astrophysically interpretable manner (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The XPM Catalogue: absolute proper motions of 280 million stars

We combined data from the Two-Micron All Sky Survey (2MASS) and USNO-A2.0 catalogues in order to derive the absolute proper motions of about 280 million stars distributed all over the sky excluding a small region near the Galactic Centre, in the magnitude range  12 < B < 19 mag  . The proper motions were derived from the 2MASS Point Sources and USNO-A2.0 catalogue positions with a mean epoch difference of about 45 years for the Northern hemisphere and about 17 years for the Southern one. The zero-point of the absolute proper motion frame (the 'absolute calibration') was specified with the use of about 1.45 million galaxies from 2MASS. Most of the systematic zonal errors inherent in the USNO-A2.0 catalogue were eliminated before the calculation of proper motions. The mean formal error of absolute calibration is less than 1 mas yr⁻¹. The XPM Catalogue will be available via CDS in Strasbourg during 2010. The generated catalogue contains the International Celestial Reference System positions of stars for the J2000 epoch, original absolute proper motions, as well as   B , R , J , H   and K magnitudes. A comparison of the proper motions obtained in this work with the data of other recent catalogues of quasars was fulfilled.     

Effects of scattering and dust grain size on the temperature structure of protoplanetary discs: a three-layer approach

The temperature in the optically thick interior of protoplanetary discs is essential for the interpretation of millimetre observations of the discs, for the vertical structure of the discs, for models of the disc evolution and the planet formation, and for the chemistry in the discs. Since large icy grains have a large albedo even in the infrared, the effect of scattering of the diffuse radiation in the discs on the interior temperature should be examined. We have performed a series of numerical radiation transfer simulations, including isotropic scattering by grains with various typical sizes for the diffuse radiation as well as for the incident stellar radiation. We also have developed an analytic model including isotropic scattering to understand the physics concealed in the numerical results. With the analytic model, we have shown that the standard two-layer approach is valid only for grey opacity (i.e. grain size ≳10 μm) even without scattering. A three-layer interpretation is required for grain size ≲10 μm. When the grain size is 0.1–10 μm, the numerical simulations show that the isotropic scattering reduces the temperature of the disc interior. This reduction is nicely explained by the analytic three-layer model as a result of the energy loss by scatterings of the incident stellar radiation and of the warm diffuse radiation in the disc atmosphere. For grain size ≳10 μm (i.e. grey scattering), the numerical simulations show that the isotropic scattering does not affect the interior temperature. This is nicely explained by the analytic two-layer model; the energy loss by scattering in the disc atmosphere is exactly offset by the 'green-house effect' due to the scattering of the cold diffuse radiation in the interior.     

exofit: orbital parameters of extrasolar planets from radial velocities

Retrieval of orbital parameters of extrasolar planets poses considerable statistical challenges. Due to sparse sampling, measurement errors, parameters degeneracy and modelling limitations, there are no unique values of basic parameters, such as period and eccentricity. Here, we estimate the orbital parameters from radial velocity data in a Bayesian framework by utilizing Markov Chain Monte Carlo (MCMC) simulations with the Metropolis–Hastings algorithm. We follow a methodology recently proposed by Gregory and Ford. Our implementation of MCMC is based on the object-oriented approach outlined by Graves. We make our resulting code, exofit , publicly available with this paper. It can search for either one or two planets as illustrated on mock data. As an example we re-analysed the orbital solution of companions to HD 187085 and HD 159868 from the published radial velocity data. We confirm the degeneracy reported for orbital parameters of the companion to HD 187085, and show that a low-eccentricity orbit is more probable for this planet. For HD 159868, we obtained slightly different orbital solution and a relatively high 'noise' factor indicating the presence of an unaccounted signal in the radial velocity data. exofit is designed in such a way that it can be extended for a variety of probability models, including different Bayesian priors.     

A systematic fitting scheme for caustic-crossing microlensing events

We outline a method for fitting binary-lens caustic-crossing microlensing events based on the alternative model parametrization proposed and detailed by Cassan. As an illustration of our methodology, we present an analysis of OGLE-2007-BLG-472, a double-peaked Galactic microlensing event with a source crossing the whole caustic structure in less than three days. In order to identify all possible models we conduct an extensive search of the parameter space, followed by a refinement of the parameters with a Markov Chain Monte Carlo algorithm. We find a number of low-  χ²  regions in the parameter space, which lead to several distinct competitive best models. We examine the parameters for each of them, and estimate their physical properties. We find that our fitting strategy locates several minima that are difficult to find with other modelling strategies and is therefore a more appropriate method to fit this type of event.     

FIRI—A far-infrared interferometer

Half of the energy ever emitted by stars and accreting objects comes to us in the far-infrared (FIR) waveband and has yet to be properly explored. We propose a powerful Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging spectroscopy in the FIR. This key observational capability is essential to reveal how gas and dust evolve into stars and planets, how the first luminous objects in the Universe ignited, how galaxies formed, and when super-massive black holes grew. FIRI will disentangle the cosmic histories of star formation and accretion onto black holes and will trace the assembly and evolution of quiescent galaxies like our Milky Way. Perhaps most importantly, FIRI will observe all stages of planetary system formation and recognise the birth of planets via its ability to image the dust structures in planetary systems. FIRI is an observatory-class mission concept: three cold, 3.5-m apertures, orbiting a beam-combining module, with separations of up to 1 km, free-flying or tethered, operating between 25 and 385 μm, using the interferometric direct-detection technique to ensure μJy sensitivity and 0.02” resolution at 100 μm, across an arcmin² instantaneous field of view, with a spectral resolution, R ~ 5,000 and a heterodyne system with R ~ 1 million. Although FIRI is an ambitious mission, we note that FIR interferometry is appreciably less demanding than at shorter wavelengths. On behalf of the following scientists: Javier Alcolea, David Alexander, Philippe Andre, Rafael Bachiller, Mike Barlow, Andrey Baryshev, Alain Baudry, Carlton Baugh, Dominic Benford, Ted Bergin, Frank Bertoldi, Geoffrey Blake, Andrew Blain, Sylvain Bontemps, Franois Bouchet, Francois Boulanger, Jeroen Bouwman, Jonathan Braine, Bernhard Brandl, Valentin Bujarrabal, Sylvie Cabrit, Martin Caldwell, Daniela Calzetti, John Carpenter, Emmanuel Caux, Cecilia Ceccarelli, Jose Cernicharo Quintanilla, Pierre Chanial, Andrea Cimatti, John Conway, Pierre Cox, Dave Clements, Bill Dent, Gianfranco De Zotti, Carsten Dominik, Loretta Dunne, Steve Eales, Nicholas Elias, Duncan Farrah, Mike Fich, Jacqueline Fischer, Alberto Franceschini, David Frayer, Carlos Frenk, Gary Fuller, Maryvonne Gerin, Martin Giard, Thijs de Graauw, Gian Luigi Granato, Jane Greaves, Matt Griffin, Rolf Guesten, Stephane Guilloteau, Martin Harwit, Thomas Henning, Eric Herbst, Michiel Hogerheijde, Kate Isaak, Christine Joblin, Eelco van Kampen, Hubert Klahr, Kirsten Kraiberg Knudsen, Oliver Krause, Cedric Lacey, Robert Laing, Jean-Michel Lamarre, Huib Jan van Langevelde, David Leisawitz, Simon Lilly, Darek Lis, Rene Liseau, Enrico Lorenzini, Dieter Lutz, Michael Macintyre, Suzanne Madden, Roberto Maiolino, Jesus Martin-Pintado, Karine Mercier, Karl Menton, Vincent Minier, Raphael Moreno, Harvey Moseley, Takao Nakagawa, David Neufeld, Michael Olberg, Seb Oliver, Luca Olmi, Goran Olofsson, Hans Olofsson, Mat Page, Pantelis Papadopoulos, Juan Pardo, John Pearson, Ismael Perez-Fournon, Sabine Philipp, Rene Plume, Albrecht Poglitsch, Jean-Loup Puget, John Richer, Dimitra Rigopoulou, Stephen Rinehart, Peter Roelfsema, Paolo Saraceno, Rudolf Schieder, Karl-Friedrich Schuster, Gene Serabyn, Stephen Serjeant, Robert Simon, Ian Smail, Luigi Spinoglio, Jason Stevens, Eckhard Sturm, Juergen Stutzki, Bruce Swinyard, Emma Taylor, Floris van der Tak, Leonardo Testi, Wing-Fai Thi, Mattia Vaccari, Lars Venema, Laurent Vigroux, Serena Viti, Catherine Vlahakis, Christoffel Waelkens, Malcolm Walmsley, Fabian Walter, Rens Waters, Paul van der Werf, Paul Wesselius, Glenn White, Wolfgang Wild, Tom Wilson, Adam Woodcraft, Gillian Wright, FriedrichWyrowski, Harold Yorke, Min Yun, Jonas Zmuidzinas     

Dynamics of planets in retrograde mean motion resonance

In a previous paper (Gayon and Bois 2008a), we have shown the general efficiency of retrograde resonances for stabilizing compact planetary systems. Such retrograde resonances can be found when two-planets of a three-body planetary system are both in mean motion resonance and revolve in opposite directions. For a particular two-planet system, we have also obtained a new orbital fit involving such a counter-revolving configuration and consistent with the observational data. In the present paper, we analytically investigate the three-body problem in this particular case of retrograde resonances. We therefore define a new set of canonical variables allowing to express correctly the resonance angles and obtain the Hamiltonian of a system harboring planets revolving in opposite directions. The acquiring of an analytical “rail” may notably contribute to a deeper understanding of our numerical investigation and provides the major structures related to the stability properties. A comparison between our analytical and numerical results is also carried out.     

The role of social networks in natural resource governance: What relational patterns make a difference?

Resent research has identified the existence of social networks as a common and important denominator in cases where different stakeholders have come together to effectively deal with natural resource problems and dilemmas. It has even been shown that social networks can be more important than the existence of formal institutions for effective enforcement and compliance with environmental regulations. However, all social networks are not created equal. On the contrary, the structural pattern of relations (i.e. the topology) of a social network can have significant impact on how actors actually behave. This clearly has implications for actors’ abilities to manage environmental challenges. This review aims to add more precision to initial insights and pending hypotheses about the positive impacts of social networks on governance processes and outcomes, by reviewing and synthesizing empirically based literature explicitly studying structural characteristics of social networks in natural resource governance settings. It is shown that significant differences in governance processes and outcomes can be expected among networks experiencing structural differences in terms of density of relations, degree of cohesiveness, subgroup interconnectivity, and degree of network centralization. Furthermore, the review shows that none of these structural characteristics present a monotonically increasing positive effect on processes of importance for resource governance, and that favoring one characteristic likely occurs at the expense of another. Thus, assessing the most favorable level and mix of different network characteristics, where most of the positive governance effects are obtained while undesired effects are minimized, presents a key research and governance challenge.