618 research outputs found

    Efficiency of tree-based water status indicators at the onset of water deficit in citrus

    Get PDF
    5 páginas.-- 3 figuras.-- 5 tablas.-- 18 referenciasThis experiment evaluates the potential of using parameters based on tree trunk fluctuations for detecting water deficit in citrus trees under two different water saving-irrigation strategies: sustained deficit irrigation and partial root-zone drying. Three irrigation treatments were applied: 1) Control: trees were irrigated with 100% of their evapotranspirative needs (ETc); 2) 60 sustained deficit irrigation (SDI): 60% ETc; and 3) partial root-zone drying (PRD): 100% ETc needs, applied to only one-half of root zone. Maximum daily shrinkage (MDS), trunk growth rate (TGR), and MDS ratio (ratio between MDS of stressed trees and control trees) were determined. Day-to-day MDS values varied largely and could not be used to determine tree water deficit. TGR did not show significant differences among treatments at this level of stress. Nevertheless, the MDS ratio was a reliable indicator to measure tree water status, and it was more sensitive for detecting water deficit at the onset of a water deficit in trees under SDI than in trees under PRD.The authors thank the Consejo Superiorde Investigaciones Científicas (CSIC) for funding the stay of S. Elsayed-Farag at the Texas A&M University-Kingsville Citrus Center and her JAE-predoc fellowship and Ayako Kusakabe, research associate at the Citrus Center, for her technical support.Peer reviewe

    Metagenomic-based Surveillance of Pacific Coast tick Dermacentor occidentalis Identifies Two Novel Bunyaviruses and an Emerging Human Ricksettsial Pathogen.

    Get PDF
    An increasing number of emerging tick-borne diseases has been reported in the United States since the 1970s. Using metagenomic next generation sequencing, we detected nucleic acid sequences from 2 novel viruses in the family Bunyaviridae and an emerging human rickettsial pathogen, Rickettsia philipii, in a population of the Pacific Coast tick, Dermacentor occidentalis in Mendocino County sampled annually from 2011 to 2014. A total of 250 adults of this human-biting, generalist tick were collected from contiguous chaparral and grassland habitats, and RNA from each individually extracted tick was deep sequenced to an average depth of 7.3 million reads. We detected a Francisella endosymbiont in 174 ticks (70%), and Rickettsia spp. in 19 ticks (8%); Rickettsia-infected ticks contained R. rhipicephali (16 of 250, 6.4%) or R. philipii (3 of 250,1.2%), the agent of eschar-associated febrile illness in humans. The genomes of 2 novel bunyaviruses (>99% complete) in the genera Nairovirus and Phlebovirus were also identified and found to be present in 20-91% of ticks, depending on the year of collection. The high prevalence of these bunyaviruses in sampled Dermacentor ticks suggests that they may be viral endosymbionts, although further studies are needed to determine whether they are infectious for vertebrate hosts, especially humans, and their potential role in tick ecology

    Discovery of active enhancers through bidirectional expression of short transcripts

    Get PDF
    Abstract Background Long-range regulatory elements, such as enhancers, exert substantial control over tissue-specific gene expression patterns. Genome-wide discovery of functional enhancers in different cell types is important for our understanding of genome function as well as human disease etiology. Results In this study, we developed an in silico approach to model the previously reported phenomenon of transcriptional pausing, accompanied by divergent transcription, at active promoters. We then used this model for large-scale prediction of non-promoter-associated bidirectional expression of short transcripts. Our predictions were significantly enriched for DNase hypersensitive sites, histone H3 lysine 27 acetylation (H3K27ac), and other chromatin marks associated with active rather than poised or repressed enhancers. We also detected modest bidirectional expression at binding sites of the CCCTC-factor (CTCF) genome-wide, particularly those that overlap H3K27ac. Conclusions Our findings indicate that the signature of bidirectional expression of short transcripts, learned from promoter-proximal transcriptional pausing, can be used to predict active long-range regulatory elements genome-wide, likely due in part to specific association of RNA polymerase with enhancer regions

    HPC Enhanced Large Urban Area Evacuation Simulations with Vision based Autonomously Navigating Multi Agents

    Get PDF
    AbstractAn evacuation simulation code based on Multi Agent Systems (MAS), with moderately complex agents in 2D grid envi- ronments, is developed. The main objective of this code is to estimate the effectiveness of the measures taken to smoothen and speedup the evacuation process of a large urban area, in time critical events like tsunami. A vision based autonomous navigation algorithm, which enables the agents to move through an urban environment and reach a far visible destination, is implemented. This simple algorithm enables a visitor agent to navigate through urban area and reach a destination which is several kilometers away. The navigation algorithm is verified comparing the simulated evacuation time and the paths taken by individual agents with those of theoretical. Further, a parallel computing extension is developed for studying mass evacuation of large areas; vision based autonomous navigation is computationally intensive. Several strategies like communication hiding, dynamic load balancing, etc. are implemented to attain high parallel scalability. Preliminary tests on the K-computer attained strong scalability above 94% at least up to 2048 CPU cores, with 2 million agents

    Nitrogen management.

    Get PDF
    bitstream/item/210621/1/Nitrogen-Management.pd

    Fusion of SPOT5 multispectral and Ikonos panchromatic images

    No full text
    International audienceThe offer of high spectral and high spatial resolutions images has grown in the last decade. It is know possible to obtain data from different sources with different spatial and spec-tral resolutions. The field of data fusion of remotely sensed data grown also very fast in the last years. In this paper, an algorithm allowing the merging of SPOT 5 images and Ikonos images are proposed. This algorithm is based on the ARSIS concept and presents an implementation for a ratio of spatial resolution equal to 10. The ARSIS concept is first detailed. Then, the way of de-fining a new implementation based on this concept is presented, allowing to understand how to define new implementations and to develop new solutions based on this concept. The proposed algorithm is developed, describing the different steps for building a fused product from a SPOT 5 multispectral data at 10 m and from a IKONOS panchromatic data at 1 m. Some other methods are proposed. The evaluation of the quality of the different methods is achieved using a set of quantitative quality parameters. The visual quality of the products are evaluated by a set of inter-preters. Conclusions are drawn on the quality of the proposed products

    Dos años de estudios aerobiológicos en Vélez-Málaga (sur de España): periodo Febrero-Junio

    Get PDF
    XV lnternational A.P.L.E. Symposium of Palynolog

    Una arquitectura basada en ontologías para anotación semántica de imágenes en el dominio de la biomedicina

    Get PDF
    Con el objetivo de ayudar a los usuarios a traducir sus necesidades de información en estrategias efectivas de búsquedas, es propuesta una arquitectura que soporta el proceso de anotación semántica de imágenes en el dominio médico usando múltiples fuentes de información, pudiendo estas ser ontologías, taxonomías, vocabularios controlados y metatesauros. La arquitectura propuesta se basa en el uso de dos ontologías, una para describir el contenido de la imagen y sus respectivas regiones y otra para mapear las descripciones de cada imagen con los conceptos que se encuentran en las diversas fuentes de información. Este mapeamento permite enriquecer la imagen con contenido semántico posibilitando la interpretación, por parte del computador, de los conceptos representados en cada región. La idea es que el usuario al seleccionar una región de la imagen, se extraiga una lista de términos para usarse como consulta en sistemas de recuperación de información. El uso de ontologías permite extender esta consulta usando diversos tipos de relaciones como por ejemplo sinónimos, nombres escritos en otros idiomas, enfermedades relacionadas, síntomas, tratamientos, entre otros.Sociedad Argentina de Informática e Investigación Operativ
    corecore