Different Domains of the RNA Polymerase of Infectious Bursal Disease Virus Contribute to Virulence

BACKGROUND: Infectious bursal disease virus (IBDV) is a pathogen of worldwide significance to the poultry industry. IBDV has a bi-segmented double-stranded RNA genome. Segments A and B encode the capsid, ribonucleoprotein and non-structural proteins, or the virus polymerase (RdRp), respectively. Since the late eighties, very virulent (vv) IBDV strains have emerged in Europe inducing up to 60% mortality. Although some progress has been made in understanding the molecular biology of IBDV, the molecular basis for the pathogenicity of vvIBDV is still not fully understood. METHODOLOGY, PRINCIPAL FINDINGS: Strain 88180 belongs to a lineage of pathogenic IBDV phylogenetically related to vvIBDV. By reverse genetics, we rescued a molecular clone (mc88180), as pathogenic as its parent strain. To study the molecular basis for 88180 pathogenicity, we constructed and characterized in vivo reassortant or mosaic recombinant viruses derived from the 88180 and the attenuated Cu-1 IBDV strains. The reassortant virus rescued from segments A of 88180 (A88) and B of Cu-1 (BCU1) was milder than mc88180 showing that segment B is involved in 88180 pathogenicity. Next, the exchange of different regions of BCU1 with their counterparts in B88 in association with A88 did not fully restore a virulence equivalent to mc88180. This demonstrated that several regions if not the whole B88 are essential for the in vivo pathogenicity of 88180. CONCLUSION, SIGNIFICANCE: The present results show that different domains of the RdRp, are essential for the in vivo pathogenicity of IBDV, independently of the replication efficiency of the mosaic viruses

Experiential learning and the acquisition of managerial tacit knowledge

Tacit knowledge is believed to be one factor that distinguishes successful managers from others. We sought to determine whether levels of accumulated managerial tacit knowledge (LAMTK) were associated with managers' dominant learning styles. Instruments used in the study, involving 356 Malaysian public sector employees, included Sternberg et al.'s (2000) Tacit Knowledge Inventory for Managers and a normative version of Kolb's (1999a) Learning Styles Inventory (LSI-Ill). Findings suggest that LAMTK is independent of the length of subjects' general work experience, but positively related to the amount of time spent working in a management context. Learning styles also had a significant relationship. Subjects who spent most of their time performing management functions and whose dominant learning styles were accommodating had significantly higher LAMTK than those with different learning styles. We also found support for the belief that learners with a strong preference for all four different abilities defined in Kolb's learning theory may be critical for effective experiential learning

Exploring the Potential of a School Impact on Pupil Weight Status: Exploratory Factor Analysis and Repeat Cross-Sectional Study of the National Child Measurement Programme.

Schools are common sites for obesity prevention interventions. Although many theories suggest that the school context influences weight status, there has been little empirical research. The objective of this study was to explore whether features of the school context were consistently and meaningfully associated with pupil weight status (overweight or obese). Exploratory factor analysis of routinely collected data on 319 primary schools in Devon, England, was used to identify possible school-based contextual factors. Repeated cross-sectional multilevel analysis of five years (2006/07-2010/11) of data from the National Child Measurement Programme was then used to test for consistent and meaningful associations. Four school-based contextual factors were derived which ranked schools according to deprivation, location, resource and prioritisation of physical activity. None of which were meaningfully and consistently associated with pupil weight status, across the five years. The lack of consistent associations between the factors and pupil weight status suggests that the school context is not inherently obesogenic. In contrast, incorporating findings from education research indicates that schools may be equalising weight status, and obesity prevention research, policy and practice might need to address what is happening outside schools and particularly during the school holidays.This article is freely available online via Open Access. Click on the 'Additional Link' above to access the full-text via the publisher's site