290 research outputs found

    Construction of Sly-miR393 Over-Expression Vector and Verification of Its Target Genes in Tomato

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    To understand the function of Sly-miR393 in tomato, the precursor sequences and potential target genes of Sly-miR393 were identificated from tomato genome database by computational homology search method. The Sly-miR393 gene was amplified from the genomic DNA by PCR and cloned into plant expression vector pLP35s-100. Sly-miR393 guided-cleavage to putative target  transcripts was validated u sing 5RACE RT-PCR. In this study, our results indicated that the precursor sequence of Sly-miR393 contains the complete hairpin  structure. TIR1/AFB auxin receptor genes contain recognition sites with high complementarities to Sly-miR393 sequence. In tomato, Sly-miR393 directs the cleavage of SlTIR1,SlTIR1-like1 and SlAFB mRNA, then auxin receptor homologous was validated to be as target of Sly-miR393. The pLP35s-pre-SlymiR393 vector containing Sly-miR393 gene was successfully constructed, which would provide significant evidence for further study of Sly-miR393 function in auxin signaling pathway in tomato

    Towards offering more useful data reliably to mobile cloudfrom wireless sensor network

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    The integration of ubiquitous wireless sensor network (WSN) and powerful mobile cloud computing (MCC) is a research topic that is attracting growing interest in both academia and industry. In this new paradigm, WSN provides data to the cloud, and mobile users request data from the cloud. To support applications involving WSN-MCC integration, which need to reliably offer data that are more useful to the mobile users from WSN to cloud, this paper first identifies the critical issues that affect the usefulness of sensory data and the reliability of WSN, then proposes a novel WSN-MCC integration scheme named TPSS, which consists of two main parts: 1) TPSDT (Time and Priority based Selective Data Transmission) for WSN gateway to selectively transmit sensory data that are more useful to the cloud, considering the time and priority features of the data requested by the mobile user; 2) PSS (Priority-based Sleep Scheduling) algorithm for WSN to save energy consumption so that it can gather and transmit data in a more reliable way. Analytical and experimental results demonstrate the effectiveness of TPSS in improving usefulness of sensory data and reliability of WSN for WSN-MCC integration

    Polymer aggregation correlated transition from Schottky-junction to bulk heterojunction organic solar cells

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    The fullerene-based organic Schottky-junction solar cells have recently attracted intensive research interest because of their unique electrical performance, such as significant photocurrent generation from excitons created in fullerenes and large open-circuit voltage (VOC) output induced by high Schottky-barrier height between the anode and the fullerene acceptor. This manuscript reports another remarkably appealing advantage that the fullerene-based Schottky-junction solar cells are more stable than the bulk heterojunction counterparts. The better stability is likely due to mitigative polymer photo-oxidation and/or little morphological change of active film in the aged Schottky-junction devices. The transition from Schottky-junction to bulk heterojunction appears at polymer donor loading ratio of 20–25 wt.% by examining the variation in the VOC with increased loading ratio of the poly(3-hexylthiophene) donor. Multiple experimental evidences, including the absorbance spectrum measurement, photoluminescence study, active film morphology characterization, and charge mobility measurement, conclusively reveal that the transition from Schottky-junction to bulk heterojunction is correlated to the polymer donor aggregation in the active films

    Polymer aggregation correlated transition from Schottky-junction to bulk heterojunction organic solar cells

    Get PDF
    The fullerene-based organic Schottky-junction solar cells have recently attracted intensive research interest because of their unique electrical performance, such as significant photocurrent generation from excitons created in fullerenes and large open-circuit voltage (VOC) output induced by high Schottky-barrier height between the anode and the fullerene acceptor. This manuscript reports another remarkably appealing advantage that the fullerene-based Schottky-junction solar cells are more stable than the bulk heterojunction counterparts. The better stability is likely due to mitigative polymer photo-oxidation and/or little morphological change of active film in the aged Schottky-junction devices. The transition from Schottky-junction to bulk heterojunction appears at polymer donor loading ratio of 20–25 wt.% by examining the variation in the VOC with increased loading ratio of the poly(3-hexylthiophene) donor. Multiple experimental evidences, including the absorbance spectrum measurement, photoluminescence study, active film morphology characterization, and charge mobility measurement, conclusively reveal that the transition from Schottky-junction to bulk heterojunction is correlated to the polymer donor aggregation in the active films

    Silencing Sl-EBF1 and Sl-EBF2 expression causes constitutive ethylene response phenotype, accelerated plant senescence, and fruit ripening in tomato

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    The hormone ethylene regulates a wide range of plant developmental processes and EBF (EIN3-binding F-box) proteins were shown to negatively regulate the ethylene signalling pathway via mediating the degradation of EIN3/EIL proteins. The present study reports on the identification of two tomato F-box genes, Sl-EBF1 and Sl-EBF2 from the EBF subfamily. The two genes display contrasting expression patterns in reproductive and vegetative tissues and in response to ethylene and auxin treatment. Sl-EBF1 and Sl-EBF2 genes are actively regulated at crucial stages in the development of the reproductive organs. Their dynamic expression in flowers during bud-to-anthesis and anthesis-to-post-anthesis transitions, and at the onset of fruit ripening, suggests their role in situations where ethylene is required for stimulating flower opening and triggering fruit ripening. VIGS-mediated silencing of a single tomato EBF gene uncovered a compensation mechanism that tends to maintain a threshold level of Sl-EBF expression via enhancing the expression of the second Sl-EBF gene. In line with this compensation, tomato plants silenced for either of the Sl-EBF genes were indistinguishable from control plants, indicating functional redundancy among Sl-EBF genes. By contrast, co-silencing of both Sl-EBFs resulted in ethylene-associated phenotypes. While reports on EBF genes to date have focused on their role in modulating ethylene responses in Arabidopsis, the present study uncovered their role in regulating crucial stages of flower and fruit development in tomato. The data support the hypothesis that protein degradation via the ubiquitin/26S proteasome pathway is a control point of fruit ripening and open new leads for engineering fruit quality

    Beacon-based opportunistic scheduling in wireless body area network

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    Wireless Body Area Networks (WBANs) are one of the key technologies that support the development of digital health care, which has attracted increasing attention in recent years. Compared with general Wireless Sensor Networks (WSNs), WBANs have more stringent requirements on reliability and energy efficiency. Though WBANs are applied within limited transmission range, the on-body channel condition can be very challenging because of blocking or absorbing of signal. In this paper, we are looking into the design of Medium Access Control (MAC) protocols and propose an opportunistic scheduling scheme by applying heuristic scheduling and dynamic superframe length adjustment to improve the system performance. The simulations have been supplemented to show the advantages of the proposed solutions in outage rate performance, compared with existing solutions

    Climate change impact on China food security in 2050

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    Climate change is now affecting global agriculture and food production worldwide. Nonetheless the direct link between climate change and food security at the national scale is poorly understood. Here we simulated the effect of climate change on food security in China using the CERES crop models and the IPCC SRES A2 and B2 scenarios including CO2 fertilization effect. Models took into account population size, urbanization rate, cropland area, cropping intensity and technology development. Our results predict that food crop yield will increase +3-11 % under A2 scenario and +4 % under B2 scenario during 2030-2050, despite disparities among individual crops. As a consequence China will be able to achieve a production of 572 and 615 MT in 2030, then 635 and 646 MT in 2050 under A2 and B2 scenarios, respectively. In 2030 the food security index (FSI) will drop from +24 % in 2009 to -4.5 % and +10.2 % under A2 and B2 scenarios, respectively. In 2050, however, the FSI is predicted to increase to +7.1 % and +20.0 % under A2 and B2 scenarios, respectively, but this increase will be achieved only with the projected decrease of Chinese population. We conclude that 1) the proposed food security index is a simple yet powerful tool for food security analysis; (2) yield growth rate is a much better indicator of food security than yield per se; and (3) climate change only has a moderate positive effect on food security as compared to other factors such as cropland area, population growth, socio-economic pathway and technology development. Relevant policy options and research topics are suggested accordingly
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