Succession in harvestman (Opiliones) communities within an abandoned sand quarry in Belgium

Sand mining strongly alters the existing landscape, transforming an area into a mosaic of native (sand deposits) and foreign soils, strongly influencing biotic development. The method of restoration of such excavated areas is often debated: natural succession or active restoration. We investigated how natural succession shapes harvestman communities, as part of the soil-dwelling community. We sampled harvestmen over a continuous period of 14 months in 25 plots in an abandoned sand quarry in Belgium using pitfall traps. We found significant increases in harvestman activity-density, species richness and diversity with time since abandonment of the various sections of the quarry. After about 15 years, a drastic change in species composition was observed with the establishment of forest species that more strongly depend on humid conditions to complete their life cycle. Colonisation of harvestmen closely followed vegetation succession despite their limited mobility. We argue that natural succession could be a good management tool for restoring harvestman communities as well as those of other soil-dwelling invertebrates in abandoned sand quarries

Corporate Governance and Acquisitions: Acquirer Wealth Effects in the Netherlands

We examine 865 acquisitions by Dutch industrial firms over the period 1993–2004. Theoretical work based on principal–agent problems predicts that managers of exchange-listed corporations may pursue acquisitions even when these do not add value for the shareholders. Corporate governance structures serve to constrain managers in their acquisition activity. In this chapter we measure the shareholder wealth effects of acquisitions and the factors that determine these wealth effects, including the governance characteristics of corporations. Firms in the Netherlands are interesting from the perspective of corporate governance, because the managerial board has a relatively strong position vis-à-vis shareholders. Several takeover defenses commonly used in the Netherlands not only limit shareholder influence during takeover battles, but also in absence of such fights. On the other hand, ownership is relatively concentrated, which may provide shareholders with the incentives and power to monitor the management. The average abnormal stock return following acquisition announcements is 1.1%, which is a significant positive effect. There is only a significant negative impact of the so-called structured regime, a situation where several shareholder rights are delegated to the supervisory board. This result suggests that governance improves acquisition decisions.The Netherlands;Corporate governance;Event study;Mergers & acquisitions

Samenwerking van huisartsen en apothekers

Tussen huisartsen en openbare apothekers bestaat een direkte wederzijdse professionele relatie doordat zij een gedeelde verantwoordelijkheid hebben voor de farmacotherapie van de patiënt. Door de nieuwe ontwikkelingen in de farmacotherapie zijn de mogelijkheden alsook de bijwerkingen en interacties toegenomen. De farmacotherapie is een van de belangrijkste oorzaken van iatrogene ziekte. Inzicht in elkaars taak en werkwijze t.a.v. farmacotherapie lijkt dan ook het minste wat mag worden verwacht van huisarts en apotheker. Dit onderzoek beschrijft de mogelijkheden en resultaten van jarenlang overleg tussen huisartsen en apothekers in Rotterdam-West . De werkwijze van de individuele deelnemer zal, om privacy redenen, niet beschreven worden