1,650 research outputs found

    Chronic bronchial infection in stable COPD: To treat or not to treat

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    Chronic bronchial infection; COPDInfección bronquial crónica; EPOCInfecció bronquial crònica; MPO

    Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests

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    At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical “land management” practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species’ habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species

    Plant β-diversity i in human-altered forest ecosystems: the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages

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    An understanding of spatial patterns of plant species diversity and the factors that drive those patterns is critical for the development of appropriate biodiversity management in forest ecosystems. We studied the spatial organization of plants species in human- modified and managed oak forests (primarily, Quercus faginea) in the Central Pre- Pyrenees, Spain. To test whether plant community assemblages varied non-randomly across the spatial scales, we used multiplicative diversity partitioning based on a nested hierarchical design of three increasingly coarser spatial scales (transect, stand, region). To quantify the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages and identify the determinants of plant diversity patterns, we used canonical ordination. We observed a high contribution of ˟-diversity to total -diversity and found ˟-diversity to be higher and ˞-diversity to be lower than expected by random distributions of individuals at different spatial scales. Results, however, partly depended on the weighting of rare and abundant species. Variables expressing the historical management intensities of the stand such as mean stand age, the abundance of the dominant tree species (Q. faginea), age structure of the stand, and stand size were the main factors that explained the compositional variation in plant communities. The results indicate that (1) the structural, spatial, and topographical characteristics of the forest stands have the greatest effect on diversity patterns, (2) forests in landscapes that have different land use histories are environmentally heterogeneous and, therefore, can experience high levels of compositional differentiation, even at local scales (e.g., within the same stand). Maintaining habitat heterogeneity at multiple spatial scales should be considered in the development of management plans for enhancing plant diversity and related functions in human-altered forest

    Identification of ovule and seed genes from Citrus clementina

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    [EN] Seedlessness is a highly desirable trait in fresh fruit. Citrus varieties, such as Clementine mandarin and other related species, show parthenocarpic fruit development without seeds due to self-incompatibility. In spite of that, these fruits frequently contain seeds as a result of cross-pollination by insects with compatible pollen from other citrus cultivars grown nearby. To solve this problem using a biotechnological approach we aim at the destruction of ovules and/or seeds by directing the expression of a toxic gene using the promoter of an ovule and/or seed specific gene. With the purpose of isolating this kind of genes we constructed two cDNA libraries from ovules and seeds at different developmental stages of the Clementine mandarin (Citrus clementina cv. Clemenules). A total of 1,014 ESTs from the ovule library and 1,042 ESTs from the seed library were generated, with a novelty percentage of 27% and 36% among the Spanish Citrus Functional Genomic Project (CFGP) ESTs database, respectively. Quantitative PCR analysis confirmed nearly specific expression in ovule and/or seed of two genes, TRANSPARENT TESTA16 (CcTT16) and TRANSPARENT TESTA7 (CcTT7). Expression of these two genes is restricted to early seed development, and is localized in the embryo sac and endothelium. The promoters of those genes may be useful to genetically engineer citrus species to avoid seed formation in fruits of commercial varieties.The authors thank Dr. L. Navarro and J. Juarez, from the Instituto Valenciano de Investigaciones Agrarias (Generalitat Valenciana), for the use of the Clementine orchard and Fortune pollen; Dr. J Forment and the Genomics Facility at the IBMCP for sequence analysis and maintenance of to the CFGP database; and Drs. F Tadeo and J Carbonell for critical reading of the manuscript. This work was supported by grants from the Conselleria de Agricultura, Pesca y Alimentacion (Generalitat Valenciana) and Spanish Ministerio de Ciencia y Tecnologia (research grant GEN2001-4885-C05). A.G-L. received a PhD fellowship from the Conselleria de Agricultura, Pesca y Alimentacion.García Lor, A.; Garcia Martinez, JL.; Perez Amador, MA. (2012). Identification of ovule and seed genes from Citrus clementina. Tree Genetics and Genomes. 8(2):227-235. doi:10.1007/s11295-011-0435-xS22723582Al-Shahrour F, Diaz-Uriarte R, Dopazo J (2005) Discovering molecular functions significantly related to phenotypes by combining gene expression data and biological information. Bioinformatics 21:2988–2993Al-Shahrour F, Minguez P, Tarraga J, Montaner D, Alloza E, Vaquerizas JMM, Conde L, Blaschke C, Vera J, Dopazo J (2006) BABELOMICS: a systems biology perspective in the functional annotation of genome-scale experiments. Nucleic Acids Res 34:W472–W476Alos E, Cercos M, Rodrigo MJ, Zacarias L, Talon M (2006) Regulation of color break in citrus fruits. Changes in pigment profiling and gene expression induced by gibberellins and nitrate, two ripening retardants. J Agric Food Chem 54:4888–4895Bugos RC, Chiang VL, Zhang XH, Campbell ER, Podila GK, Campbell WH (1995) RNA isolation from plant tissues recalcitrant to extraction in guanidine. Biotechniques 19:734–737Costantini E, Landi L, Silvestroni O, Pandolfini T, Spena A, Mezzetti B (2007) Auxin synthesis-encoding transgene enhances grape fecundity. Plant Physiol 143:1689–1694Debeaujon I, Nesi N, Perez P, Devic M, Grandjean O, Caboche M, Lepiniec L (2003) Proanthocyanidin-accumulating cells in Arabidopsis testa: regulation of differentiation and role in seed development. Plant Cell 15:2514–2531Dorcey E, Urbez C, Blazquez MA, Carbonell J, Perez-Amador MA (2009) Fertilization-dependent auxin response in ovules triggers fruit development through the modulation of gibberellin metabolism in Arabidopsis. Plant J 58:318–332Debeaujon I, Peeters AJ, Léon-Kloosterziel KM, Koornneef M (2001) The TRANSPARENT TESTA12 gene of Arabidopsis encodes a multidrug secondary transporter-like protein required for flavonoid sequestration in vacuoles of the seed coat endothelium. Plant Cell 13:853–571Forment J, Gadea J, Huerta L, Abizanda L, Agusti J, Alamar S, Alos E, Andres F, Arribas R, Beltran JP, Berbel A, Blazquez MA, Brumos J, Canas LA, Cercos M, Colmenero-Flores JM, Conesa A, Estables B, Gandia M, Garcia-Martinez JL, Gimeno J, Gisbert A, Gomez G, Gonzalez-Candelas L, Granell A, Guerra J, Lafuente MT, Madueno F, Marcos JF, Marques MC, Martinez F, Martinez-Godoy MA, Miralles S, Moreno P, Navarro L, Pallas V, Perez-Amador MA, Perez-Valle J, Pons C, Rodrigo I, Rodriguez PL, Royo C, Serrano R, Soler G, Tadeo F, Talon M, Terol J, Trenor M, Vaello L, Vicente O, Vidal C, Zacarias L, Conejero V (2005) Development of a citrus genome-wide EST collection and cDNA microarray as resources for genomic studies. Plant Mol Biol 57:375–391Forment J, Gilabert F, Robles A, Conejero V, Nuez F, Blanca JM (2008) EST2uni: an open, parallel tool for automated EST analysis and database creation, with a data mining web interface and microarray expression data integration. BMC Bioinformatics 9:5Fos M, Nuez F, Garcia-Martinez JL (2000) The gene pat-2, which induces natural parthenocarpy, alters the gibberellin content in unpollinated tomato ovaries. Plant Physiol 122:471–480Fos M, Proaño K, Nuez F, Garcia-Martinez JL (2001) Role of gibberellins in parthenocarpic fruit development induced by the genetic system pat-3/pat-4 in tomato. Physiol Plant 111:545–550Hashimoto JG, Beadles-Bohling AS, Wiren KM (2004) Comparison of RiboGreen and 18S rRNA quantitation for normalizing real-time RT-PCR expression analysis. Biotechniques 36:54–60Haughn G, Chaudhury A (2005) Genetic analysis of seed coat development in Arabidopsis. Trends Plant Sci 10:472–477Hartley RW (1988) Barnase and barstar. Expression of its cloned inhibitor permits expression of a cloned ribonuclease. J Mol Biol 202:913–915Jackson DP (1992) In situ hybridization in plants. In: Bowles DJ, Gurr SJ, Pherenson M (eds) Molecular plant pathology: a practical approach. Oxford University Press, Oxford, UK, pp 163–174Koltunow AM (1993) Isolation and construction of genes to control seed production in Citrus. In: Hyashi T, Omura M, Scott NS (eds) Techniques on gene diagnosis and breeding. Fruit Tree Research Station, Tsukuba, Japan, pp 101–108Koltunow AM, Soltys K, Nito N, Mcclure S (1995) Anther, ovule, seed and nucellar embryo development in Citrus sinensis cv Valencia. Can J Bot 73:1567–1582Koltunow AM, Brennan P, Bond JE, Barker SJ (1998) Evaluation of genes to reduce seed size in Arabidopsis and tobacco and their application to Citrus. Mol Breeding 4:235–251Le BH, Cheng C, Bui AQ, Wagmaister JA, Henry KF, Pelletier J, Kwong L, Belmonte M, Kirkbride R, Horvath S, Drews GN, Fischer RL, Okamuro JK, Harada JJ, Goldberg RB (2010) Global analysis of gene activity during Arabidopsis seed development and identification of seed-specific transcription factors. Proc Natl Acad Sci USA 107:8063–8070Li DD, Shi W, Deng XX (2002) Agrobacterium-mediated transformation of embryogenic calluses of Ponkan mandarin and the regeneration of plants containing the chimeric ribonuclease gene. Plant Cell Rep 21:153–156Marques MC, Alonso-Cantabrana H, Forment J, Arribas R, Alamar S, Conejero V, Perez-Amador MA (2009) A new set of ESTs and cDNA clones from full-length and normalized libraries for gene discovery and functional characterization in citrus. BMC Genomics 10:428Mezzetti B, Landi L, Pandolfini T, Spena A (2004) The DefH9-iaaM auxin-synthesizing gene increases plant fecundity and fruit production in strawberry and raspberry. BMC Biotechnology 4:4Nesi N, Debeaujon I, Jond C, Stewart AJ, Jenkins GI, Caboche M, Lepiniec L (2002) The TRANSPARENT TESTA16 locus encodes the ARABIDOPSIS BSISTER MADS domain protein and is required for proper development and pigmentation of the seed coat. Plant Cell 14:2463–2479Olimpieri I, Siligato F, Caccia R, Mariotti L, Ceccarelli N, Soressi GP, Mazzucato A (2007) Tomato fruit-set driven by pollination or by the parthenocarpic fruit allele are mediated by transcriptionally regulated gibberellin biosynthesis. Planta 226:877–888Peer AW, Brown DE, Tague BW, Muday GK, Taiz L, Murphy AS (2001) Flavonoid accumulation patterns of transparent testa mutants of Arabidopsis. Plant Physiol 126:536–548Rommens CM, Haring MA, Swords K, Davies HV, Belknap WR (2007) The intragenic approach as a new extension to traditional plant breeding. Trends Plant Sci 12:397–403Rotino GL, Acciarri N, Sabatini E, Mennella G, Scalzo RL, Maestrelli A, Molesini B, Pandolfini T, Scalzo J, Mezzetti B, Spena A (2005) Open field trial of genetically modified parthenocarpic tomato: seedlessness and fruit quality. BMC Biotechnol 5:32Schoenbohm C, Martens S, Eder C, Forkmann G, Weisshaar B (2000) Identification of the Arabidopsis thaliana flavonoid 3′-hydroxylase gene and functional expression of the encoded P450 enzyme. Biol Chem 381:749–753Schwabe WW, Mills JJ (1981) Hormones and parthenocarpic fruit set: a literature survey. Hort Abstr 51:661–698Singh DP, Filardo FF, Storey R, Jermakow AM, Yamaguchi S, Swain SM (2010) Overexpression of a gibberellin inactivation gene alters seed development, KNOX gene expression, and plant development in Arabidopsis. Physiol Plant 138:74–90Talon M, Zacarias L, Primo-Millo E (1992) Gibberellins and parthenocarpic ability in developing ovaries of seedless mandarins. Plant Physiol 99:1575–1581Zimmermann P, Hirsch-Hoffmann M, Hennig L, Gruissem W (2004) GENEVESTIGATOR: Arabidopsis microarray database and analysis toolbox. Plant Physiol 136:2621–2632Zhulidov PA, Bogdanova EA, Shcheglov AS, Vagner LL, Khaspekov GL, Kozhemyako VB, Matz MV, Meleshkevitch E, Moroz LL, Lukyanov SA, Shagin DA (2004) Simple cDNA normalization using Kamchatka crab duplex-specific nuclease. Nucleic Acids Res 32:e3

    Search for H alpha emitters in Galaxy Clusters with Tunable Filters

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    The studies of the evolution of galaxies in Galaxy Clusters have as a traditional complication the difficulty in establishing cluster membership of those sources detected in the field of view. The determination of spectroscopic redshifts involves long exposure times when it is needed to reach the cluster peripherical regions of/or clusters at moderately large redshifts, while photometric redshifts often present uncertainties too large to offer significant conclusions. The mapping of the cluster of galaxies with narrow band tunable filters makes it possible to reach large redshifts intervals with an accuracy high enough to establish the source membership of those presenting emission/absorption lines easily identifiable, as H alpha. Moreover, the wavelength scan can include other lines as [NII], [OIII] or HβH_{\beta} allowing to distinguish those sources with strong stellar formation activity and those with an active galactic nuclei. All this makes it possible to estimate the stellar formation rate of the galaxies observed. This, together with ancillary data in other wavelengths may lead to a good estimation of the stellar formation histories. It will shed new light over the galaxy evolution in clusters and will improve our understanding of galaxy evolution, especially in the outer cluster regions, usually less studied and with significant unexploited data that can not be correctly interpreted without redshift determination.Comment: 4 pages, 2 figures. "Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11 July, 200

    Local knowledge of Arceuthobium genus in a Natural Protected Area of the centre of Mexico

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    La Dra. Tizbe Teresa Arteaga Reyes participó: (i) en el Proyecto de la Red IberoLatinoamericana para el Aprovechamiento y Conservación de Recursos Bióticos (RILACREB), intitulado Aprovechamiento y protección del conocimiento etnobotánico tradicional y de la agrodiversidad: estudios de caso “zona centro del estado de Veracruz” y “Parque Nacional Nevado de Toluca”; (ii) en la dirección de la tesis (Tutora Académica) de Doctorado en Ciencias Agropecuarias y Recursos Naturales de la C. Alma Inés Sotero García; y (iii) en la redacción de los artículos científicos como autora por correspondencia y como coautora en el capítulo de libro. Tanto la tesis de doctorado como los artículos científicos y el capítulo de libro fueron productos derivados de dicho proyecto de investigación.El género Arceuthobium (muérdago enano) es una de las principales plagas en los bosques templados de México, con antecedentes de uso medicinal y forrajero. El objetivo de este trabajo fue documentar el conocimiento local sobre los usos del muérdago enano en el Área Natural Protegida Nevado de Toluca, México, bajo las perspectivas emic y etic, a través de la etnobotánica. Mediante entrevistas se identificó que ambas especies (A. vaginatum y A. globosum) son conocidas como muérdago y forman parte de la flora del bosque; sin embargo, los entrevistados desconocen los efectos negativos dentro de los ecosistemas forestales de esta plaga. Destacan los usos lúdicos, como juguete y tinta, y los medicinales para el tratamiento de afecciones respiratorias y del sistema nervioso, siendo éste el primer registro para dicho género localmente. Se requieren estudios que validen el conocimiento local para su inclusión en programas locales de manejo de plagas forestales.El Consejo Nacional de Ciencia y Tecnología (CONACYT) por la beca para los estudios de Doctorado en Ciencias Agropecuarias y Recursos Naturales. Al Programa de Mejoramiento del Profesorado (PROMEP) de la SEP por el financiamiento del Proyecto de la Red IberoLatinoamericana para el Aprovechamiento y Conservación de Recursos Bióticos (RILACREB), intitulado Aprovechamiento y protección del conocimiento etnobotánico tradicional y de la agrodiversidad: estudios de caso “zona centro del estado de Veracruz” y “Parque Nacional Nevado de Toluca”

    Full Tilt: Universal Constructors for General Shapes with Uniform External Forces

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    We investigate the problem of assembling general shapes and patterns in a model in which particles move based on uniform external forces until they encounter an obstacle. In this model, corresponding particles may bond when adjacent with one another. Succinctly, this model considers a 2D grid of “open” and “blocked” spaces, along with a set of slidable polyominoes placed at open locations on the board. The board may be tilted in any of the 4 cardinal directions, causing all slidable polyominoes to move maximally in the specified direction until blocked. By successively applying a sequence of such tilts, along with allowing different polyominoes to stick when adjacent, tilt sequences provide a method to reconfigure an initial board configuration so as to assemble a collection of previous separate polyominoes into a larger shape. While previous work within this model of assembly has focused on designing a specific board configuration for the assembly of a specific given shape, we propose the problem of designing universal configurations that are capable of constructing a large class of shapes and patterns. For these constructions, we present the notions of weak and strong universality which indicate the presence of “excess” polyominoes after the shape is constructed. In particular, for given integers h, w, we show that there exists a weakly universal configuration with O(hw) 1 × 1 slidable particles that can be reconfigured to build any h × w patterned rectangle. We then expand this result to show that there exists a weakly universal configuration that can build any h × w-bounded size connected shape. Following these results, which require an admittedly relaxed assembly definition, we go on to show the existence of a strongly universal configuration (no excess particles) which can assemble any shape within a previously studied “drop” class, while using quadratically less space than previous results. Finally, we include a study of the complexity of deciding if a particle within a configuration may be relocated to another position, and deciding if a given configuration may be transformed into a second given configuration. We show both problems to be PSPACE-complete even when no particles stick to one another and movable particles are restricted to 1 × 1 tiles and a single 2 × 2 polyomino
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