1,039 research outputs found

    Object DUO 2: A New Binary Lens Candidate

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    We present the light curve of an unusual variable object, DUO 2, detected during the search for microlensing events by the DUO project. The star remained stable for more than 150 days before it brightened by more than two magnitudes in 6 days in the B and R bands. The light curves are achromatic during the variability. We consider possible explanations of the photometric behavior, with particular emphasis on the binary lens interpretation of the event. The masses of the lenses are quite small, with the companion possibly in the range of a brown dwarf or even a few times of Jupiter. We report evidence of blending of the source by a companion through the first detection of shift in the light centroid among all the microlensing experiments. This shift sets a lower limit of 0.3′′0.3^{\prime\prime} on the separation between the stars. The best lens model obtained requires moderate blending, which was what motivated us to check the centroid shift that was subsequently found. The best lens model predicts a separation of 1′′1^{\prime\prime} between the two blended stars. This prediction was recently tested using two CCD images taken under good seeing conditions. Both images show two components. Their separation and position angle are in good agreement with our model.Comment: uuencoded, compressed PostScript, 4 pages, 4 figures (in text). Accepted for publication in Astronomy and Astrophysics Letter

    AGAPEROS: Searching for variable stars in the LMC Bar with the Pixel Method. I. Detection, astrometry and cross-identification

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    We extend the work developed in previous papers on microlensing with a selection of variable stars. We use the Pixel Method to select variable stars on a set of 2.5 x 10**6 pixel light curves in the LMC Bar presented elsewhere. The previous treatment was done in order to optimise the detection of long timescale variations (larger than a few days) and we further optimise our analysis for the selection of Long Timescale and Long Period Variables (LT&LPV). We choose to perform a selection of variable objects as comprehensive as possible, independent of periodicity and of their position on the colour magnitude diagram. We detail the different thresholds successively applied to the light curves, which allow to produce a catalogue of 632 variable objects. We present a table with the coordinate of each variable, its EROS magnitudes at one epoch and an indicator of blending in both colours, together with a finding chart. A cross-correlation with various catalogues shows that 90% of those variable objects were undetected before, thus enlarging the sample of LT&LPV previously known in this area by a factor of 10. Due to the limitations of both the Pixel Method and the data set, additional data -- namely a longer baseline and near infrared photometry -- are required to further characterise these variable stars, as will be addressed in subsequent papers.Comment: 11 pages with 10 figure

    Low-energy molecular collisions in a permanent magnetic trap

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    Cold, neutral hydroxyl radicals are Stark decelerated and confined within a magnetic trap consisting of two permanent ring magnets. The OH molecules are trapped in the ro-vibrational ground state at a density of ∼106\sim10^{6} cm−3^{-3} and temperature of 70 mK. Collisions between the trapped OH sample and supersonic beams of atomic He and molecular D2_{2} are observed and absolute collision cross sections measured. The He--OH and D2_{2}--OH center-of-mass collision energies are tuned from 60 cm−1^{-1} to 230 cm−1^{-1} and 145 cm−1^{-1} to 510 cm−1^{-1}, respectively, yielding evidence of reduced He--OH inelastic cross sections at energies below 84 cm−1^{-1}, the OH ground rotational level spacing.Comment: 4 pages, 4 figure

    Au Tchad, le projet terroir-exploitation-parcelle : un exemple de collaboration étroite entre la recherche et le développement

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    Méthodologie, démarche, zonage et objectifs sont définis de façon commune par la recherche, les sociétés de développement, les organisations non gouvernementales et les acteurs des terroirs. Neuf zones aux problématiques agraires homogènes ont été identifiées. Des enquêtes ont permis de choisir les terroirs pilotes représentatifs, de définir leurs activités, de connaître les statuts fonciers, les stratégies et autres règles d'accès aux ressources ainsi que de classer les problèmes relevés par les villageois. Les diagnostics - au niveau du terroir, de l'exploitation et de la parcelle - ont traduit ces connaissances en termes techniques et quantifiables. Les transects ont été un support très important de ces informations et des réunions entre les partenaires. Des solutions ont été mises au point puis testées par les volontaires. Citons les jachères courtes, les plantes de couverture et le semis direct, la culture associée céréales-légumineuses, les cultures en couloir, le recyclage el la valorisation des résidus de récolte, la lutte contre l'érosion et l'aménagement de bassins versants. Une innovation technique est en premier lieu choisie pour ses résultats à court terme et ses effets sur l'occupation de l'espace. Mois l'innovation la plus marquante a été sociale : la concertation entre les différents groupes d'intérêt du terroir. Elle a permis des accords sur une instance locale et concertée de gestion de conflits, la création de couloirs de passage des troupeaux, etc. Cette dynamique a aussi abouti au financement d'un centre de formation à la station de Bébédjia. (Résumé d'auteur

    Hostal Aritzaiko Navarra – España

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    The building, constructed on approximately 790 square meters, is devoted to a dining room and lodging for visitors in transit and is situated in Echarri-Aranaz, next to the highway, on a clearing in the woods, It possesses an extensive ground floor and two upper levéis covering smaller areas which rise, as a side body, over one of the building's sides. The overall structure houses a bar, dining room, kitchen, management office and a total of eight double rooms and two single rooms. An important double-pitch roof, which covers the two upper floors, together with another with several pitches which with its different planes conforms to the irregular perimeter of the structure on the ground floor, give the building the distinctive characteristics of the architecture typical of the region, in this way adaptedEl edificio, de aproximadamente 790 m2 construidos, se destina a comedor y hospedaje para personas en tránsito, estando emplazado en Echarri - Aranaz, junto a la carretera, en el calvero de un bosque. Cuenta con una extensa planta baja y dos niveles superiores, de superficie más reducida, que se elevan, a modo de cuerpo lateral, sobre uno de los costados del edificio. El conjunto de la edificación distribuye los servicios de bar, comedor, cocina, administración, y un total de 8 dormitorios dobles y 2 sencillos. Una importante cubierta a dos aguas, que abarca a las dos plantas más altas, junto a otra de varias aguas, que con sus distintos planos se ajusta al perímetro irregular de la construcción en planta baja, imprimen al edificio las características propias de la arquitectura popular de la reglón, que se ve así homologada en un planteamiento arquitectónico moderno

    Biopreservation of hepatocytes: current concepts on hypothermic preservation, cryopreservation, and vitrification

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    Isolated liver cells (primarily isolated hepatocytes) have found important applications in science and medicine over the past 40 years in a wide range of areas, including physiological studies, investigations on liver metabolism, organ preservation and drug de-toxification, experimental and clinical transplantation. An integral component of many of these works is the need to store the isolated cells, either for short or long-term periods. This review covers the biopreservation of liver cells, with a focus on the history of liver cell biopreservation, the application of hypothermia for short-term storage, standard cryopreservation methods for isolated hepatocytes, the biopreservation of other types of liver cells, and recent developments such as vitrification of hepatocytes. By understanding the basis for the different approaches, it will be possible to select the best options for liver cell biopreservation in different applications, and identify ways to improve preservation protocols for the future.Fil: Fuller, Barry J.. University College London; Estados UnidosFil: Petrenko, Alexander Y.. Ukraine Academy of Sciences; UcraniaFil: Rodriguez, Joaquin Valentin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; ArgentinaFil: Somov, Alexander Y.. Ukraine Academy of Sciences; UcraniaFil: Balaban, Cecilia Lucía. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Guibert, Edgardo Elvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; Argentin

    The role of antibiotics in the treatment of chronic prostatitis: A consensus statement

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    Practical guidelines for the diagnosis and treatment of chronic prostatitis are presented. Chronic prostatitis is classified as chronic bacterial prostatitis (culture-positive) and chronic inflammatory prostatitis (culture-negative). If chronic bacterial prostatitis is suspected, based on relevant symptoms or recurrent UTIs, underlying urological conditions should be excluded by the following tests: rectal examination, midstream urine culture and residual urine. The diagnosis should be confirmed by the Meares and Stamey technique. Antibiotic therapy is recommended for acute exacerbations of chronic prostatitis, chronic bacterial prostatitis and chronic inflammatory prostatitis, if there is clinical, bacteriological or supporting immunological evidence of prostate infection. Unless a patient presents with fever, antibiotic treatment should not be initiated immediately except in cases of acute prostatitis or acute episodes in a patient with chronic bacterial prostatitis. The work-up, with the appropriate investigations should be done first, within a reasonable time period which, preferably, should not be longer than 1 week. During this period, nonspecific treatment, such as appropriate analgesia to relieve symptoms, should be given. The minimum duration of antibiotic treatment should be 2-4 weeks. If there is no improvement in symptoms, treatment should be stopped and reconsidered. However, if there is improvement, it should be continued for at least a further 2-4 weeks to achieve clinical cure and, hopefully, eradication of the causative pathogen. Antibiotic treatment should not be given for 6-8 weeks without an appraisal of its effectiveness. Currently used antibiotics are reviewed. Of these, the fluoroquinolones ofloxacin and ciprofloxacin are recommended because of their favourable antibacterial spectrum and pharmacokinetic profile. A number of clinical trials are recommended and a standard study design is proposed to help resolve some outstanding issues

    A photometric catalogue of galaxies in the cluster Abell 85

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    We present two catalogues of galaxies in the direction of the rich cluster \a85. The first one includes 4,232 galaxies located in a region ±1∘\pm 1^\circ from the cluster centre. It has been obtained from a list of more than 25,000 galaxy candidates detected by scanning a Schmidt photographic plate taken in the \bj band. Positions are very accurate in this catalogue but magnitudes are not. This led us to perform CCD imaging observations in the V and R bands to calibrate these photographic magnitudes. A second catalogue (805 galaxies) gives a list of galaxies with CCD magnitudes in the V and R bands for a much smaller region in the centre of the cluster. These two catalogues will be combined with a redshift catalogue of 509 galaxies (Durret et al. 1997; astro-ph/9709298) to investigate the cluster properties at optical wavelengths (Durret et al. in preparation), as a complement to our previous X-ray studies (Pislar et al. 1997, Lima-Neto et al. 1997).Comment: accepted for publication in A&AS; 7 pages, including 8 figures, Tables are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5

    DENIS-P J104814.7-395606.1: An M9 dwarfs at about 4 pc

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    We present the discovery of a previously unknown member of the immediate solar neighbourhood, DENIS-P J104814.7-395606.1 (hereafter DENIS 1048-39), identified while mining the DENIS database for new nearby stars. A HIRES echelle spectrum obtained with the 10-m Keck telescope shows that it is an M9 dwarf. DENIS 1048-39 has a very bright apparent magnitude (I=12.67) for its spectral type and colour (I-J=3.07), and is therefore very nearby. If it is single its distance is only 4.1 +- 0.6pc, ranking it as between our twelfth and fortyth closest neighbour. It is also the closest star or brown dwarf with a spectral type later than M7V. Its proper motion was determined through comparison of Sky atlas Schmidt plates, scanned by the MAMA microdensitometer, with the DENIS images. At 1.53"/yr it further attests the closeness of DENIS 1048-39, and hence its dwarf status. These characteristics make it an obvious target for further detailed studies.Comment: In press in A&A Letter
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