757 research outputs found

    Root exudates impact plant performance under abiotic stress

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    Plant root exudates serve pivotal roles in supporting plant development and interactions with the physicochemical and biological factors in the rhizosphere. Under stress conditions, root exudation is involved in enhancing plant resource-use efficiency and facilitating the crosstalk between plant and soil microbes to ameliorate stress. Although there are a large number of root exudates that remain to be characterized, recent technological advancements have allowed for the function of many exudate compounds to be elucidated. In this review, we discuss current knowledge about the key root exudates that modulate plant resource-use efficiency under various abiotic stresses including drought, aluminum toxicity, phosphorus, nitrogen, and iron deficiency. The role that key root exudates play in shaping microbial communities in the rhizosphere under stress conditions is also an important consideration addressed in this review

    Assessment of Bacterial Inoculant Delivery Methods for Cereal Crops

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    Despite growing evidence that plant growth-promoting bacteria can be used to improve crop vigor, a comparison of the different methods of delivery to determine which is optimal has not been published. An optimal inoculation method ensures that the inoculant colonizes the host plant so that its potential for plant growth-promotion is fully evaluated. The objective of this study was to compare the efficacy of three seed coating methods, seedling priming, and soil drench for delivering three bacterial inoculants to the sorghum rhizosphere and root endosphere. The methods were compared across multiple time points under axenic conditions and colonization efficiency was determined by quantitative polymerase chain reaction (qPCR). Two seed coating methods were also assessed in the field to test the reproducibility of the greenhouse results under non-sterile conditions. In the greenhouse seed coating methods were more successful in delivering the Gram-positive inoculant (Terrabacter sp.) while better colonization from the Gram-negative bacteria (Chitinophaga pinensis and Caulobacter rhizosphaerae) was observed with seedling priming and soil drench. This suggested that Gram-positive bacteria may be more suitable for the seed coating methods possibly because of their thick peptidoglycan cell wall. We also demonstrated that prolonged seed coating for 12 h could effectively enhance the colonization of C. pinensis, an endophytic bacterium, but not the rhizosphere colonizing C. rhizosphaerae. In the field only a small amount of inoculant was detected in the rhizosphere. This comparison demonstrates the importance of using the appropriate inoculation method for testing different types of bacteria for their plant growth-promotion potential

    Development of Web Tools for NLX Simulation Software

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    Valuable mathematical equations have developed within biology and other sciences (physics, chemistry, etc.) that model various processes, but the complexity of the equations are not easily understood by students, scientists, and those with limited knowledge of the subject area. Simulation software used to visually explain a model is normally proprietary to the specific model equations and cannot be easily adapted to new models by non-programmers. Simulation software needs to be modular and based upon web technologies so that the software can be run on multiple platforms. The NLX simulation software is a group of Java-based objects that can be combined with any model equations to create interactive HTML simulation pages rapidly. No simple interface exists to build simulation pages with the software. The goal of the project is to create a tool by which biologists or any scientist, instructor, or general user, could convert an abstract mathematical model into a visually comprehensible and interactive simulation using NLX. The project succeeds in providing a graphical user interface for the NLX software that opens the technology to users that have a limited coding background, as well as providing users with assistance in understanding the behavior of complex mathematical models

    Friendly Hackers to the Rescue: How Organizations Perceive Crowdsourced Vulnerability Discovery

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    Over the past years, crowdsourcing has increasingly been used for the discovery of vulnerabilities in software. While some organizations have extensively used crowdsourced vulnerability discovery, other organizations have been very hesitant in embracing this method. In this paper, we report the results of a qualitative study that reveals organizational concerns and fears in relation to crowdsourced vulnerability discovery. The study is based on 36 key informant interviews with various organizations. The study reveals a set of pre-adoption fears (i.e., lacking managerial expertise, low quality submissions, distrust in security professionals, cost escalation, lack of motivation of security professionals) as well as the post-adoption issues actually experienced. The study also identifies countermeasures that adopting organizations have used to mitigate fears and minimize issues. Implications for research and practice are discussed

    Prevalence and geographical distribution of Papio hamadryas papillomavirus 1 (PhPV1) in Kenyan baboons

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    Papio hamadryas papillomavirus (PhPV) 1, 2, and 3, are Alphapapillomaviruses that have been detected in Kenyan Olive baboons but the distribution is unknown. Therefore, cervical screening for PhPV1 was performed in baboons from various areas in Kenya using a nested polymerase chain reaction. The prevalence rate was 33%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135993/1/jmp12247.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135993/2/jmp12247_am.pd

    Psychometric Properties of the Service Leadership Attitude Scale in Hong Kong

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    Positive attitude to service leadership is fundamental for the development of successful leadership qualities in the service-dominated economy. The purpose of this study was to examine the psychometric properties of the 46-item Service Leadership Attitude Scale (SLA) in Hong Kong. A total of 2,240 undergraduate students in Hong Kong (mean age = 20.44±1.64 years; 66.9% were female) completed a questionnaire containing the 46-item SLA and other leadership-related scales. The psychometric properties of SLA were assessed using confirmatory factor analyses (CFA), reliability analyses, measurement invariance tests, and convergent validity test. Previous exploratory factor analyses suggested a seven-factor model of SLA which was supported by CFA in this study. By adding an additional dimension (“Implicit leadership theory”) in the scale, the final eight-factor model with 46 items showed superior fit using CFA. Factorial invariance tests showed that the factor structure was invariant in terms of construct dimensionality, factor loadings, intercepts, and factor covariance across gender and subgroups split based on “odd” and “even” case numbers. Convergent validity tests showed that the scale scores were correlated with several leadership-related scales. The scale and subscales also demonstrated good internal consistency reliability. This study is the first scientific work to validate a measure of attitude to service leadership via CFA. It contributes significantly to the development and validation of measures of attitude to service leadership, particularly in the higher education sector
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