Culling-Induced Changes in Badger (Meles meles) Behaviour, Social Organisation and the Epidemiology of Bovine Tuberculosis

In the UK, attempts since the 1970s to control the incidence of bovine tuberculosis (bTB) in cattle by culling a wildlife host, the European badger (Meles meles), have produced equivocal results. Culling-induced social perturbation of badger populations may lead to unexpected outcomes. We test predictions from the ‘perturbation hypothesis’, determining the impact of culling operations on badger populations, movement of surviving individuals and the influence on the epidemiology of bTB in badgers using data dervied from two study areas within the UK Government's Randomised Badger Culling Trial (RBCT). Culling operations did not remove all individuals from setts, with between 34–43% of badgers removed from targeted social groups. After culling, bTB prevalence increased in badger social groups neighbouring removals, particularly amongst cubs. Seventy individual adult badgers were fitted with radio-collars, yielding 8,311 locational fixes from both sites between November 2001 and December 2003. Home range areas of animals surviving within removed groups increased by 43.5% in response to culling. Overlap between summer ranges of individuals from Neighbouring social groups in the treatment population increased by 73.3% in response to culling. The movement rate of individuals between social groups was low, but increased after culling, in Removed and Neighbouring social groups. Increased bTB prevalence in Neighbouring groups was associated with badger movements both into and out of these groups, although none of the moving individuals themselves tested positive for bTB. Significant increases in both the frequency of individual badger movements between groups and the emergence of bTB were observed in response to culling. However, no direct evidence was found to link the two phenomena. We hypothesise that the social disruption caused by culling may not only increase direct contact and thus disease transmission between surviving badgers, but may also increase social stress within the surviving population, causing immunosuppression and enhancing the expression of disease

The Impact of the Dual Board Structure and Board Diversity: Evidence from Chinese Initial Public Offerings (IPOs)

Chinese listed companies have a two-tier (dual) governance structure that comprises a supervisory board/committee (SB) and the board of directors (BoD). However, as there is no hierarchical relationship between them, the two boards are independent. This is different from the governance mechanism in Continental Europe in which the SB appoints the directors of the management board; in this sense, the Chinese two-tier governance structure is unique. We investigate the impact of governance characteristics and ownership structure on gender diversity of both the BoD and the SB for a sample of 892 Chinese Initial Public Offerings floated in both the Shanghai and Shenzhen Stock Exchanges. We find that the average proportion of female directors and female SB members on the BoD and the SB are 10 and 22 %, respectively. Using both static and dynamic panel data methods, we find that there is no significant impact of board structure on gender diversity in China. However, we find a positive and significant relationship between SB size and gender diversity. We also find that the higher the state ownership, the lower the female representation on both boards. Finally, our findings show that there is a bi-directional relationship between financial performance and the proportion of female directors sitting on the BoD