169 research outputs found

    Effects of virus infection on release of volatile organic compounds from insect-damaged bean, Phaseolus vulgaris

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    Insects can serve as important vectors of plant pathogens, especially viruses. Insect feeding on plants causes the systemic release of a wide range of plant volatile compounds that can serve as an indirect plant defense by attracting natural enemies of the herbivorous insect. Previous work suggests that the Mexican bean beetle (Epilachna varivestis) prefers to feed on plants infected by either of two viruses that it is known to transmit: Southern bean mosaic virus (SBMV) or Bean pod mottle virus (BPMV). A possible explanation for the preferred feeding on virus-infected tissues is that the beetles are attracted by volatile signals released from leaves. The purpose of this work was to determine whether volatile compounds from virus-infected plants are released differentially from those emitted by uninfected plants. To test the hypothesis, common bean plants (Phaseolus vulgaris cv. Black Valentine) were inoculated with either BPMV, SBMV, or a mixture of both viruses, and infected plants were compared to uninfected plants. An Ouchterlony assay was used with SBMVand BPMV-specific antisera to confirm the presence of virus in inoculated plants. RNA blot analysis was performed on tissue from each plant and indicated that a well-characterized defense gene, encoding phenylalanine ammonia-lyase (PAL), was not induced in systemic tissue following virus infection. Plant volatiles were collected—and analyzed via gas chromatography (GC)—from plants that were either undamaged or beetle-damaged. In undamaged plants, there were no measurable differences in profiles or quantities of compounds released by uninfected and virus-infected plants. After Mexican bean beetles were allowed to feed on plants for 48 h, injured plants released several compounds that were not released from undamaged plants. Lower quantities of volatile compounds were released from virus-infected plants suggesting that enhanced release of plant-derived volatile organic compounds is not the cause for attraction of Mexican bean beetles to virus-infected plants

    Exploring perceptions of advertising ethics: an informant-derived approach

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    Whilst considerable research exists on determining consumer responses to pre-determined statements within numerous ad ethics contexts, our understanding of consumer thoughts regarding ad ethics in general remains lacking. The purpose of our study therefore is to provide a first illustration of an emic and informant-based derivation of perceived ad ethics. The authors use multi-dimensional scaling as an approach enabling the emic, or locally derived deconstruction of perceived ad ethics. Given recent calls to develop our understanding of ad ethics in different cultural contexts, and in particular within the Middle East and North Africa (MENA) region, we use Lebanon—the most ethically charged advertising environment within MENA—as an illustrative context for our study. Results confirm the multi-faceted and pluralistic nature of ad ethics as comprising a number of dimensional themes already salient in the existing literature but in addition, we also find evidence for a bipolar relationship between individual themes. The specific pattern of inductively derived relationships is culturally bound. Implications of the findings are discussed, followed by limitations of the study and recommendations for further research

    Drucker\u27s Insights on Market Orientation and Innovation: Implications for Emerging Areas in High-Technology Marketing

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    In 1954, Drucker boldly declared that organizations have only two basic functions, marketing and innovation. While true for any organization, this insight is particularly pertinent for technology-based businesses. The complicated environment surrounding high-tech companies creates a great need for sophisticated marketing, yet these companies continue to have under-developed competencies in marketing and in understanding customer needs. In its first two sections, this essay explores Drucker’s insights with respect to two particularly salient issues for high-tech companies: developing and implementing a market orientation, and sustained break-through innovations. We review Drucker’s insights and synthesize them with the scholarly research on these issues. In the third section, we discuss three emerging areas in high-tech marketing where academics and managers could build on Drucker’s insight to guide future research and practice: market-driving, customer co-creation, and corporate social responsibility. The illustrative examples provided by these emerging areas highlight that even today, Drucker’s writings continue to offer remarkable guidance to scholars and managers who are willing to take the time to reflect, understand, and incorporate these insights in the unique context of high-tech industries

    Corporate social responsibility: an empirical investigation of U.S. organizations

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    Organizations that believe they should give something back to the society have embraced the concept of corporate social responsibility (CSR). Although the theoretical underpinnings of CSR have been frequently debated, empirical studies often involve only limited aspects, implying that theory may not be congruent with actual practices and may impede understanding and further development of CSR. The authors investigate actual CSR practices related to five different stakeholder groups, develop an instrument to measure those CSR practices, and apply it to a survey of 401 U.S. organizations. Four different clusters of organizations emerge, depending on the CSR practice focus. The distinctive features of each cluster relate to organizational demographics, perceived influence of stakeholders, managers perceptions of the influence of CSR on performance, and organizational performance

    A Fast and Stable Penalty Method for Rigid Body Simulation

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    Design and testing of a selectively compliant underactuated hand

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    From the black box to the glass box: Using unsupervised and supervised learning processes to predict user engagement for the airline companies

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    Firms collect an enormous amount of user generated content (UGC), such as social media posts, to analyze consumers’ unfiltered opinions regarding brands and firms. A challenge in analyzing unstructured UGC is the lack of analytic frame. By adopting both unsupervised and supervised learning processes for using artificial intelligence (AI), we collected 680,410, tweets related to airline companies (United Airlines, Delta Airlines, Southwest Airlines, Alaska Airlines, and Hawaiian Airlines) and analyzed 4961 retweets to predict user engagement levels on Twitter. Rooted in the electronic word-of-mouth (eWOM) perspective, the results of this study indicated that consumer sentiment was positive for United Airlines, Delta Airlines, and Alaska Airlines, whereas it was negative for Southwest Airlines and Hawaiian Airlines. We also examined the effects of word count, gaps between the tweet generated date and the retweeted date, the number of the hashtag(s), and extracted topics on predicting the level of user engagement. Ultimately, this study provided a detailed guide to mangers on how to use an unstructured data analysis procedure incorporating both supervised and unsupervised learning processes
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