scholarly journals The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains

2014 ◽  
Vol 80 (23) ◽  
pp. 7161-7168 ◽  
Author(s):  
Tory A. Hendry ◽  
Martha S. Hunter ◽  
David A. Baltrus

ABSTRACTFacultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiontRickettsiaincreases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role ofRickettsiain mediating the interaction between the sweet potato whitefly andPseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show thatP. syringaemultiplies within whiteflies, leading to host death, and that whiteflies infected withRickettsiashow a decreased rate of death due toP. syringae. Experiments using plants coated withP. syringaeconfirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected withRickettsia. These results suggest thatP. syringaemay affect whitefly populations in nature and thatRickettsiacan ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects.

2014 ◽  
Vol 25 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Amira Galin

Purpose – The purpose of this paper is to obtain insight into court-referred mediation in the Israeli Labor Courts, by analyzing its processes and outcomes, as a function of tactics used by both the disputants and the mediator. Design/methodology/approach – Observation of 103 court-referred mediations, for each of which a detailed process and outcome were documented. Data on disputants' refusal to participate in the mediation was also collected. At the end of each mediation case, disputants were given a questionnaire in which they expressed their satisfaction with the outcome and their evaluation of the mediator's contribution. Findings – A low rate of refusal to participate in court-referred mediation was found. Also, the higher the ratio of soft tactics to pressure tactics employed (by all parties involved) during the process, the higher the rate of agreements. Mediators use significantly more soft tactics than disputants, and are more active in using tactics. The two significant variables that predict the mediation's agreement are the ratio between soft tactics to pressure tactics used by all parties, and mediator contribution to the process. Practical implications – The significant role of soft tactics in the process, outcome, and satisfaction of court-referred mediation may serve as a guideline for disputants and mediators. Originality/value – This unique research, which examines the impact of tactics on court-referred mediation, may provide added and significant theoretical insight into its process and outcome, as well as a better understanding of other “hybrid” (compulsory at the beginning, voluntary at the end) mediations.


2012 ◽  
Vol 194 (23) ◽  
pp. 6678-6679 ◽  
Author(s):  
Zi-Feng Jiang ◽  
Fangfang Xia ◽  
Kipp W. Johnson ◽  
Elizabeth Bartom ◽  
Jigyasa H. Tuteja ◽  
...  

ABSTRACT“CandidatusPortiera aleyrodidarum” is the obligate primary endosymbiotic bacterium of whiteflies, including the sweet potato whiteflyBemisia tabaci, and provides essential nutrients to its host. Here we report two complete genome sequences of this bacterium from the B and Q biotypes ofB. tabaci.


2004 ◽  
pp. 406-412
Author(s):  
Paul Okunieff ◽  
Michael C. Schell ◽  
Russell Ruo ◽  
E. Ronald Hale ◽  
Walter G. O'Dell ◽  
...  

✓ The role of radiosurgery in the treatment of patients with advanced-stage metastatic disease is currently under debate. Previous randomized studies have not consistently supported the use of radiosurgery to treat patients with numbers of brain metastases. In negative-results studies, however, intracranial tumor control was high but extracranial disease progressed; thus, patient survival was not greatly affected, although neurocognitive function was generally maintained until death. Because the future promises improved systemic (extracranial) therapy, the successful control of brain disease is that much more crucial. Thus, for selected patients with multiple metastases to the brain who remain in good neurological condition, aggressive lesion-targeting radiosurgery should be very useful. Although a major limitation to success of this therapy is the lack of control of extracranial disease in most patients, it is clear that well-designed, aggressive treatment substantially decreases the progression of brain metastases and also improves neurocognitive survival. The authors present the management and a methodology for rational treatment of a patient with breast cancer who has harbored 24 brain metastases during a 3-year period.


2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.


2019 ◽  
Vol 15 (4) ◽  
pp. 406-424 ◽  
Author(s):  
Maryam Kriese ◽  
Joshua Yindenaba Abor ◽  
Elikplimi Agbloyor

Purpose The purpose of this paper is to examine the moderating role of financial consumer protection (FCP) in the access–development nexus. Design/methodology/approach The study is based on cross-country data on 102 countries surveyed in the World Bank Global Survey on FCP and Financial Literacy (2013). The White heteroscedasticity adjusted regressions and Two-stage least squares regressions (2SLS) are used for the estimation. Findings Interactions between FCP regulations that foster fair treatment, disclosure, dispute resolution and recourse and financial access have positive net effects on economic development. However, there is no sufficient evidence to suggest that interactions between financial access and enforcement and compliance monitoring regulations have a significant effect on economic development. Practical implications First, policy makers should continue with efforts aimed at instituting FCP regimes as part of strategies aimed at broadening access to financial services for enhanced economic development. Second, instituting FCP regimes per se may not be enough. Policy makers need to consider possible intervening factors such as the provision of adequate resources and supervisory authority, for compliance monitoring and enforcement to achieve the expected positive effect on economic development. Originality/value This study extends evidence in the law–finance–growth literature by providing empirical evidence on the effect of legal institution specific to the protection of retail financial consumers on the access–development nexus using a nouvel data set, the World Bank Global survey on FCP and Financial Literacy (2013).


2020 ◽  
Vol 54 (8) ◽  
pp. 1963-1986
Author(s):  
Tilottama G. Chowdhury ◽  
Feisal Murshed

Purpose This paper proposes that categorization flexibility, operationalized as the cognitive capacity that cross-categorizes products in multiple situational categories across multiple domains, might favorably influence a consumer’s evaluation of unconventional options. Design/methodology/approach Experimental research design is used to test the theory. An exploratory study first establishes the effect of categorization flexibility in a non-food domain. Study 1 documents the moderating role of decision domain, showing that the effect works only under low- (vs high-) consequence domain. Studies 2A and 2B further refine the notion by showing that individuals can be primed in a relatively higher categorization flexibility frame of mind. Study 3 demonstrates the interactive effect of categorization flexibility and adventure priming in a high-consequence domain. Study 4 integrates the interactive effects of decisions with low- vs high-consequence, adventure priming and categorization flexibility within a single decision domain of high consequence. Findings Consumers with higher- (vs lower-) categorization flexibility tend to opt for unconventional choices when the decision domain entails low consequences, whereas such a result does not hold under decision domain of high consequences. The categorization flexibility effects in case of low-consequence decision domain holds true even when consumers are primed to be categorization flexible. Furthermore, with additional adventure priming, consumers show an increased preference for unconventional options even under a decision domain with high consequence. Research limitations/implications This study could not examine real purchase behavior as results are based on cross-sectional, behavioral intention data. In addition, it did not examine the underlying reason for presence of cross-domain categorization flexibility index. Practical implications The results suggest that stimuli may be tailored to consumers in ways that increase the salience and the perceived attractiveness of unconventional choices. Further, data reinforce the notion of cross-categorical interrelations among different domains, which could be leveraged by marketers. Originality/value This study represents the first documentation of the potential ways by which unconventional product choice might be a function of individuals’ categorization flexibility level across different types of decision domains. The findings yield implications that are novel to both categorization and consumer decision-making literature.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Li Chen ◽  
Fengxia Zhu ◽  
Murali Mantrala

Purpose This paper aims to systematically investigate the direct and indirect effects of four types of support – peer instrumental support, peer emotional support, platform business support and platform communication support – on seller trade volume in social commerce. It also aims to uncover the path of support-to-sales of the seller from a platform perspective and provides a more complete picture of the social commerce phenomenon. Design/methodology/approach This paper uses multi-source data including primary survey data and secondary data on trade volume to test the hypotheses. PROCESS mediation model is used to analyze the multi-source data set. Findings This study finds that the positive effects of peer instrumental support, platform business support and platform communication support on seller trade volume are fully mediated by seller collaborative information exchange. Also, peer emotional support has a significant negative effect on seller trade volume and collaborative information exchange can serve as a buffer to mitigate the negative effect. Research limitations/implications The authors provide new insights into what types of support are or are not conducive to improving transaction volume of individual sellers and highlight the mediating role of seller information exchange in this value generation process in social commerce. These findings advance current knowledge of how seller interactions increase value in social commerce. The chosen research setting may limit the generalizability of the findings of this study. Practical implications This paper offers valuable implications for social commerce platforms on how to better serve their sellers to achieve high growth. Specifically, the findings suggest that platforms should encourage instrumental support and information exchange among peer sellers. In addition, platforms should expand seller support from a single-focus on sellers’ business to a dual-focus on both sellers’ business and socialization in social commerce. Originality/value This paper fulfills an identified need to study how sellers can better derive value from the social interactions and how social commerce platforms can effectively influence transactions, support sales and serve as a selling platform.


Author(s):  
Ali Safari ◽  
Arash Adelpanah ◽  
Razieh Soleimani ◽  
Parisa Heidari Aqagoli ◽  
Rosa Eidizadeh ◽  
...  

Purpose This study aims at investigating the effect of psychological empowerment on job burnout and competitive advantage with the mediating role of organizational commitment and creativity. Design/methodology/approach The statistical population included all the managers and staffs of Tooka Company in Iran, and for data analysis, 120 completed questionnaires were used. Data analysis was carried out by SPSS 18 and Amos 20 software and structural equation modeling method. To test the mediating relationships, bootstrap method was used. Findings The findings showed that psychological empowerment has a significant direct effect on job burnout and competitive advantage. Also, psychological empowerment has a significant indirect effect on job burnout through the mediating role of organizational commitment. In addition, psychological empowerment has a significant indirect effect on competitive advantage through the mediating role of organizational creativity. Originality/value This study is among the first to investigate the relationship between psychological empowerment, job burnout, competitive advantage, organizational commitment and creativity.


2017 ◽  
Vol 38 (5) ◽  
pp. 630-645 ◽  
Author(s):  
Won Ho Kim ◽  
Young-An Ra ◽  
Jong Gyu Park ◽  
Bora Kwon

Purpose The purpose of this paper is to examine the mediating role of burnout (i.e. exhaustion, cynicism, professional inefficacy) in the relationship between job level and job satisfaction as well as between job level and task performance. Design/methodology/approach The final sample included 342 Korean workers from selected companies. The authors employed the Hayes (2013) PROCESS tool for analyzing the data. Findings The results showed that all three subscales of burnout (i.e. exhaustion, cynicism, professional inefficacy) mediate the relationship between job level and job satisfaction. However, only two mediators (i.e. cynicism, professional inefficacy) indicated the mediating effects on the association between job level and task performance. Originality/value This research presented the role of burnout on the relationships between job level, job satisfaction, and task performance especially in South Korean organizational context. In addition to role of burnout, findings should prove helpful in improving job satisfaction and task performance. The authors provide implications and limitations of the findings.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vidya Sukumara Panicker ◽  
Rajesh Srinivas Upadhyayula

PurposeThis paper attempts to examine the activity and involvement of board of directors in internationalization activities of firms in emerging markets, by evaluating the resource provisioning roles of interlocks provided by board of directors, and the frequency of board meetings. We demonstrate that the effectiveness of board involvement is contingent upon the levels of family ownership in firms since family ownership could impact the firm’s ability to utilize the presence of different types of board members.Design/methodology/approachThe authors test our hypotheses on a sample of listed Indian companies, extracted from the Prowess database published by the Centre for Monitoring Indian Economy (CMIE), a database of the financial performance of Indian companies. On a panel of 3,133 firm years of 605 unique Indian firms with foreign investments, over a time period of 2006–2017, the authors apply different estimation techniques.FindingsThe results demonstrate that both board meeting frequency and director interlocks are instrumental in supporting internationalization activities in emerging market firms. However, family ownership moderates the role of insider and independent interlocks on internationalization investments in different ways; the authors find that interlocks provided by independent directors support internationalization activities in family firms, whereas those provided by insider directors do not. Further, the study also finds that board meetings are less effective in internationalization of family firms.Practical implicationsThe authors conclude that family firms aiming at international diversification require to develop more connected and networked independent directors to enable internationalization in firms. While independent director interlocks enhance the international investments, it is also useful to know that board meetings are ineffective in utilizing the resources in family firms. This points to the possibility that family firms should device mechanisms to integrate family meetings with board meetings so that they can utilize the within-family processes to aid in their internationalization decisions.Originality/valueThe study contributes to resource dependence theory by understanding its limiting role in family firms. Theoretically, it helps delineate the limiting resource provision role of the insider directors vis-à-vis independent directors. The authors argue that the resource provision role of insider director interlocks does not effectively help in internationalization in comparison to independent director interlocks in family-dominated firms. Consequently, the study shows the limiting role of resource provision and utilization by family-owned firms in comparison to non-family-owned firms.


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