8 research outputs found

    Epigenetic changes accompany developmental programmed cell death in tapetum cells.

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    10 páginas, 8 figuras --PAGS nros. 16-29(2014)The tapetum, the nursing tissue inside anthers, undergoes cellular degradation by programmed cell death (PCD) during late stages of microspore–early pollen development. Despite the key function of tapetum, little is known about the molecular mechanisms regulating this cell death process in which profound nuclear and chromatin changes occur. Epigenetic features (DNA methylation and histone modifications) have been revealed as hallmarks that establish the functional status of chromatin domains, but no evidence on the epigenetic regulation of PCD has been reported. DNA methylation is accomplished by DNA methyltransferases, among which DNA methyl transferase 1 (MET1) constitutes one of the CG maintenance methyltransferase in plants, also showing de novo methyltransferase activity. In this work, the changes in epigenetic marks during the PCD of tapetal cells have been investigated by a multidisciplinary approach to reveal the dynamics of DNA methylation and the pattern of expression of MET1 in relation to the main cellular changes of this PCD process which have also been characterized in two species, Brassica napus and Nicotiana tabacum. The results showed that tapetum PCD progresses with the increase in global DNA methylation and MET1 expression, epigenetic changes that accompanied the reorganization of the nuclear architecture and a high chromatin condensation, activity of caspase 3-like proteases and Cyt c release. The reported data indicate a relationship between the PCD process and the DNA methylation dynamics and MET1 expression in tapetal cells, suggesting a possible new role for the epigenetic marks in the nuclear events occurring during this cell death process and providing new insights into the epigenetic control of plant PCDThis work was supported by the Spanish Ministry of Economy and Competitivity, MINECO [BFU2011-23752]; the Spanish National Research Council, CSIC [201020E038]; the Spanish Ministry of Science and Innovation, MICINN [grant to N.C. for Stays of Foreign Postdoctoral Researchers and grant to J.C.E. for Sabaticcal Stays in Spanish Research Centre]; the Spanish Ministry of Science and Innovation, MICINN [a post-doctoral Juan-de-la-Cierva grant (JCI-2007-123-1177) to M.R.S.

    Bind-kracht in armoede: de waarde van transdisciplinair onderzoek in het sociaal werk

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    A growing literature assesses the quality of life and well-being in geographically and/or politically divided areas. The paper proposes a new subjective well being (SWB) indicator based on residents' satisfaction with environment and community, personal life and leisure activities. Our approach is a novel construction and new application of the well-being index, specifically, a DEA-like model with common weights under the benefit of the doubt (BoD) approach. This approach is very interesting in the SWB framework, allowing us to differentiate efficient individuals or estimate the relative importance of each domain in the SWB indicator. The results state that Personal life is the domain that most profoundly affects SWB index; it also differs in groups of individuals and geographic spaces. © 2012 Springer Science+Business Media Dordrecht

    The miniJPAS survey: a preview of the Universe in 56 colours

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    International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands of square degrees of the northern extragalactic sky with a unique set of 5656 optical filters from a dedicated 2.552.55m telescope, JST, at the Javalambre Astrophysical Observatory. Before the arrival of the final instrument (a 1.2 Gpixels, 4.2deg2^2 field-of-view camera), the JST was equipped with an interim camera (JPAS-Pathfinder), composed of one CCD with a 0.3deg2^2 field-of-view and resolution of 0.23 arcsec pixel1^{-1}. To demonstrate the scientific potential of J-PAS, with the JPAS-Pathfinder camera we carried out a survey on the AEGIS field (along the Extended Groth Strip), dubbed miniJPAS. We observed a total of 1\sim 1 deg2^2, with the 5656 J-PAS filters, which include 5454 narrow band (NB, FWHM145\rm{FWHM} \sim 145Angstrom) and two broader filters extending to the UV and the near-infrared, complemented by the u,g,r,iu,g,r,i SDSS broad band (BB) filters. In this paper we present the miniJPAS data set, the details of the catalogues and data access, and illustrate the scientific potential of our multi-band data. The data surpass the target depths originally planned for J-PAS, reaching magAB\rm{mag}_{\rm {AB}} between 22\sim 22 and 23.523.5 for the NB filters and up to 2424 for the BB filters (5σ5\sigma in a 33~arcsec aperture). The miniJPAS primary catalogue contains more than 64,00064,000 sources extracted in the rr detection band with forced photometry in all other bands. We estimate the catalogue to be complete up to r=23.6r=23.6 for point-like sources and up to r=22.7r=22.7 for extended sources. Photometric redshifts reach subpercent precision for all sources up to r=22.5r=22.5, and a precision of 0.3\sim 0.3% for about half of the sample. (Abridged

    The miniJPAS survey: A preview of the Universe in 56 colors

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    International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2 deg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3 deg2 field-of-view and plate scale of 0.23 arcsec pixel−1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a ∼1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHM ∼ 145 Å) and two broader filters extending to the UV and the near-infrared, complemented by the u, g, r, i SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magAB ≃ 22−23.5 in the 54 narrow band filters and up to 24 in the broader filters (5σ in a 3″ aperture). The miniJPAS primary catalog contains more than 64 000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at r = 23.6 (r = 22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to r = 22.5, and a precision of ≤0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to z ∼ 0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to z > 2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude.Key words: surveys / techniques: photometric / astronomical databases: miscellaneous / stars: general / galaxies: general / cosmology: observations⋆ miniJPAS data and associated value added catalogs are publicly available http://archive.cefca.es/catalogues/minijpas-pdr20191

    Beyond methylammonium lead iodide: prospects for the emergent field of ns 2

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