New algorithms and technologies for the un-supervised reduction of Optical/IR images

This paper presents some of the main aspects of the software library that has been developed for the reduction of optical and infrared images, an integral part of the end-to-end survey system being built to support public imaging surveys at ESO. Some of the highlights of the new library are: unbiased estimates of the background, critical for deep IR observations; efficient and accurate astrometric solutions, using multi-resolution techniques; automatic identification and masking of satellite tracks; weighted co-addition of images; creation of optical/IR mosaics, and appropriate management of multi-chip instruments. These various elements have been integrated into a system using XML technology for setting input parameters, driving the various processes, producing comprehensive history logs and storing the results, binding them to the supporting database and to the web. The system has been extensively tested using deep images as well as images of crowded fields (e.g. globular clusters, LMC), processing at a rate of 0.5 Mega-pixels per second using a DS20E ALPHA computer with two processors. The goal of this presentation is to review some of the main features of this package.Comment: 12 pages, 9 figures, conferenc

Organic Beekeeping in Mexico

Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t). Two conditions allow Mexico to possess an enormous potential for organic honey production. First, the beekeeping with Africanized honeybees: despite the problems derived from their defensiveness, these bees have great qualities in terms of natural defences against main diseases, including Varroa, so that beekeeping can be realized almost without the use of medicines, contrary to beekeeping with European bees. Second, the southern states of Mexico have a low industrialization level with small scale agriculture characterized by a rather low use of pesticides. Thus, a big part of the territory is suitable for organic honey production as it fulfils the low exposure levels of contaminants. Mexico produces approximately 1,150 tons of organic certified honey that is about 5% of the Mexican honey export. 20 operators are certified organic. Most organic producers are cooperatives with small scale beekeepers. In 2010, more than 448 organic beekeepers (and 291 beekeepers in transition) are managing more than 46,318 organic hives (and 8,629 hives in transition). Organic honey is mainly produced in the states of Yucatan, Campeche, Quintana Roo, Chiapas, Oaxaca, Morelos and Jalisco. Some of the organic beekeeping cooperatives also hold Fair Trade certificates. The first cooperatives were certified in the 1990’s in Oaxaca y Guerrero state. Naturland/IMO organized the first organic beekeeping workshop in 2001. Since 2003, El Colegio de la Frontera Sur (ECOSUR) has offered annual courses with diplomas in organic beekeeping. Naturland/ IMO trained the inspection agency Certimex on auditing organic beekeepers in 2004. The First Forum of Organic Apiculture was held in 2005 in Chetumal, followed by a second Forum in 2008 in Mérida. The premium price placed on organic honey makes the transition to organic production very attractive. For small scale beekeepers in cooperatives, an Internal Control System (ICS) has to be developed and full traceability of the product must be ensured. The documentation of the beekeepers’ activities, as well as the accounting of the honey and wax, can present some difficulties at the beginning, particularly because many of the indigenous beekeepers are illiterate. Wax from organic beekeeping is used for wax exchange within the organic projects to guarantee a closed wax cycle. Organic certifiers like Naturland, IMO and Certimex carry out wax analysis in order to ensure the absence of conventional Varroacides in the wax. If wax is contaminated, it has to be replaced and the cycle of home-grown wax has to be established. Mexico presents the most suitable conditions of biodiversity and nectar sources from extensive natural forests, traditionally not intensively developed, and more than 400,000 ha of certified agriculture land. It has the potential to increase organic honey production considerably, so that many cooperatives of small farmers may benefit by including organic beekeeping in their production

Organic beekeeping in Mexico

Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t)

Adaptation de la gestion technique des producteurs de café et de miel face aux variations de prix au Guatemala : concepts et méthodes

International audienceL'incertitude forge le quotidien des agriculteurs des municipalités de Jacaltenango et de San Antonio Huista, à la frontière occidentale du Guatemala. La communication présente le projet de recherche et les résultats intermédiaires d'une thèse de doctorat (2009-2011) portant sur l'adaptation de la gestion technique des producteurs de café et de miel des hautes terres guatémaltèques face aux variations de prix. Les concepts de logique d'action sur le long terme, de gestion technique et de flexibilité sont mobilisés pour l'étude de la trajectoire d'activités et de pratiques agricoles de 48 producteurs membres d'une association de commercialisation de café et miel. La méthodologie se décompose en quatre phases : (1) une phase exploratoire d'enquêtes compréhensives, (2) une phase exhaustive d'enquêtes semi-directives, (3) le traitement des données avec des méthodes statistiques de regroupement, (4) une vérification des corrélations statistiques observées via des monographies des systèmes d'activités. Une première confrontation de ce cadre théorique et méthodologique avec le terrain permet de préciser nos hypothèses autour des relations entre flexibilité et d'une part production biologique et d'autre part catégorie sociale de la main d'œuvre

Workers dominate male production in the neotropical bumblebee Bombus wilmattae (Hymenoptera: Apidae)

<p>Abstract</p> <p>Background</p> <p>Cooperation and conflict in social insects are closely linked to the genetic structure of the colony. Kin selection theory predicts conflict over the production of males between the workers and the queen and between the workers themselves, depending on intra-colonial relatedness but also on other factors like colony efficiency, sex ratios, cost of worker reproduction and worker dominance behaviour. In most bumblebee (<it>Bombus</it>) species the queen wins this conflict and often dominates male production. However, most studies in bumblebees have been conducted with only a few selected, mostly single mated species from temperate climate regions. Here we study the genetic colony composition of the facultative polyandrous neotropical bumblebee <it>Bombus wilmattae</it>, to assess the outcome of the queen-worker conflict over male production and to detect potential worker policing.</p> <p>Results</p> <p>A total of 120 males from five colonies were genotyped with up to nine microsatellite markers to infer their parentage. Four of the five colonies were queen right at point of time of male sampling, while one had an uncertain queen status. The workers clearly dominated production of males with an average of 84.9% +/- 14.3% of males being worker sons. In the two doubly mated colonies 62.5% and 96.7% of the male offspring originated from workers and both patrilines participated in male production. Inferring the mother genotypes from the male offspring, between four to eight workers participated in the production of males.</p> <p>Conclusions</p> <p>In this study we show that the workers clearly win the queen-worker conflict over male production in <it>B. wilmattae</it>, which sets them apart from the temperate bumblebee species studied so far. Workers clearly dominated male production in the singly as well the doubly mated colonies, with up to eight workers producing male offspring in a single colony. Moreover no monopolization of reproduction by single workers occurred.</p

Cleaning sky survey databases using Hough Transform and Renewal String approaches

Large astronomical databases obtained from sky surveys such as the SuperCOSMOS Sky Survey (SSS) invariably suffer from spurious records coming from artefactual effects of the telescope, satellites and junk objects in orbit around earth and physical defects on the photographic plate or CCD. Though relatively small in number these spurious records present a significant problem in many situations where they can become a large proportion of the records potentially of interest to a given astronomer. Accurate and robust techniques are needed for locating and flagging such spurious objects, and we are undertaking a programme investigating the use of machine learning techniques in this context. In this paper we focus on the four most common causes of unwanted records in the SSS: satellite or aeroplane tracks, scratches, fibres and other linear phenomena introduced to the plate, circular halos around bright stars due to internal reflections within the telescope and diffraction spikes near to bright stars. Appropriate techniques are developed for the detection of each of these. The methods are applied to the SSS data to develop a dataset of spurious object detections, along with confidence measures, which can allow these unwanted data to be removed from consideration. These methods are general and can be adapted to other astronomical survey data.Comment: Accepted for MNRAS. 17 pages, latex2e, uses mn2e.bst, mn2e.cls, md706.bbl, shortbold.sty (all included). All figures included here as low resolution jpegs. A version of this paper including the figures can be downloaded from http://www.anc.ed.ac.uk/~amos/publications.html and more details on this project can be found at http://www.anc.ed.ac.uk/~amos/sattrackres.htm

ESO for GOODS' sake

Currently public ESO data sets pertinent to the CDFS/GOODS field are briefly illustrated along with an indication on how to get access to them. Future ESO plans for complementing the GOODS database with optical/IR imaging and optical spectroscopy are also described.Comment: 6 pages, 2 figures, to appear in the proceedings of the ESO/USM Workshop "The Mass of Galaxies at Low and High Redshift" (Venice, Italy, October 2001), eds. R. Bender and A. Renzin

ESO Imaging Survey: infrared observations of CDF-S and HDF-S

This paper presents infrared data obtained from observations carried out at the ESO 3.5m New Technology Telescope (NTT) of the Hubble Deep Field South (HDF-S) and the Chandra Deep Field South (CDF-S). These data were taken as part of the ESO Imaging Survey (EIS) program, a public survey conducted by ESO to promote follow-up observations with the VLT. In the HDF-S field the infrared observations cover an area of ~53 square arcmin, encompassing the HST WFPC2 and STIS fields, in the JHKs passbands. The seeing measured in the final stacked images ranges from 0.79" to 1.22" and the median limiting magnitudes (AB system, 2" aperture, 5sigma detection limit) are J_AB~23.0, H_AB~22.8 and K_AB~23.0 mag. Less complete data are also available in JKs for the adjacent HST NICMOS field. For CDF-S, the infrared observations cover a total area of \~100 square arcmin, reaching median limiting magnitudes (as defined above) of J_AB~23.6 and K_AB~22.7 mag. For one CDF-S field H-band data are also available. This paper describes the observations and presents the results of new reductions carried out entirely through the un-supervised, high-throughput EIS Data Reduction System and its associated EIS/MVM C++-based image processing library developed, over the past 5 years, by the EIS project and now publicly available. The paper also presents source catalogs extracted from the final co-added images which are used to evaluate the scientific quality of the survey products, and hence the performance of the software. This is done comparing the results obtained in the present work with those obtained by other authors from independent data and/or reductions carried out with different software packages and techniques. The final science-grade catalogs and co-added images are available at CDS.Comment: Accepted for publication in A&A, 13 pages, 12 figures; a full resolution version of the paper is available from http://www.astro.ku.dk/~lisbeth/eisdata/papers/4528.pdf ; related catalogs and images are available through http://www.astro.ku.dk/~lisbeth/eisdata

The circumstellar envelope of IRC+10216 from milli-arcsecond to arcmin scales

Aims.Analysis of the innermost regions of the carbon-rich star IRC+10216 and of the outer layers of its circumstellar envelope have been performed in order to constrain its mass-loss history. Methods: .We analyzed the high dynamic range of near-infrared adaptive optics and the deep V-band images of the circumstellar envelope of IRC+10216 using high angular resolution, collected with the VLT/NACO and FORS1 instruments. Results: .From the near-infrared observations, we present maps of the sub-arcsecond structures, or clumps, in the innermost regions. The morphology of these clumps is found to strongly vary from J- to L-band. Their relative motion appears to be more complex than proposed in earlier works: they can be weakly accelerated, have a constant velocity, or even be motionless with respect to one another. From V-band imaging, we present a high spatial resolution map of the shell distribution in the outer layers of IRC+10216. Shells are resolved well up to a distance of about 90'' to the core of the nebula and most of them appear to be composed of thinner elongated shells. Finally, by combining the NACO and FORS1 images, a global view is present to show both the extended layers and the bipolar core of the nebula together with the real size of the inner clumps. Conclusions: .This study confirms the rather complex nature of the IRC+10216 circumstellar environment. In particular, the coexistence at different spatial scales of structures with very different morphologies (clumps, bipolarity, and almost spherical external layers) is very puzzling. This confirms that the formation of AGB winds is far more complex than usually assumed in current models.Comment: Published in Astronomy & Astrophysics, 2006, 455, 18