Introduction, establishment and expansion of the Pacific oyster Crassostrea gigas in the Oosterschelde (SW Netherlands)

The Pacific oyster Crassostrea gigas was first introduced as an exotic species by oyster farmers in 1964 in the Oosterschelde estuary (SW Netherlands). The initial phase is not well documented but first natural spatfall was recorded in 1975. Excessive spatfall occurred in 1976 and this is considered the start of the expansion phase of the wild oysters. Oyster beds in intertidal and subtidal areas of the Oosterschelde estuary have been growing since. The development in the intertidal area has been reconstructed by using aerial photography, validated by ground truth in 2000¿2002. In the subtidal areas extensive oyster beds have been detected by using side scan sonar; on hard substrates along the dikes coverage with oysters up to 90% locally has been recorded by scuba diving surveys. Expansion has also occurred into adjacent water bodies including the Wadden Sea. By forming resistant reefs the oysters induce structural changes in the ecosystem. It is concluded that bed area is still expanding while decrease of the fraction live animals may indicate adjustment of the stock size to the local conditions

Gina Mather

This article profiles Gina Mather who has been the president of the Australian Transgender Support Association (ATSA) for over 15 years. Her vociferous activism for social justice and equality has its roots in her work with Queensland Rail, which she joined in 1967. Gina quickly became entrenched in the union movement and soon afterwards became the secretary of the Australian Railways Union. During her time with the railways, Gina spent a considerable period of time in regional parts of Queensland, advocating for workers' rights. While her activities earned her the ire of the authorities the police tapped her phone and the then premier, Sir Joh Bjelke-Petersen, threatened to remove her as secretary of the union she persevered undeterred

DEB model for cockles (Cerastoderma edule) in the Oosterschelde

The natural and cultured shellfish populations in the Oosterschelde are of considerable biological and economical interest. The hydromorphology of the Oosterschelde is continuously changing and adapting in response to natural anthropological and climatological changes. In view of these changes and of possible future developments in the region, questions arise with regard to the impact on the system’s carrying capacity for shellfish populations. Dynamic shellfish models can help to answer these questions. In this study, a Dynamic Energy Budget (DEB) model for cockles (Cerastoderma edule) in the Oosterschelde estuary is presented

The enzymic cyclization of 6'-norsqualene-2,3-oxide

The present study is a part of an effort to determine the mechanism of action of squalene oxide-lanosterol cyclase. A brief introduction to the biosynthesis of lanosterol is given, together with a survey on the in vitro enzymic cyclizations of modified squalene-2,3-oxides. From this introduction the objective of this study becomes clear, this being the determination of the role of the 6'-methyl group in the enzymic cyclization of squalene-2,3-oxide. ... Zie: Summary

Aandacht in de klas

De doorsnee-Hollandse scholier is lastiger, onrustiger en sneller afgeleid dan zijn voorganger van pakweg twintig, dertig jaar geleden. Wie zijn oor af en toe te luisteren legt in een Nederlandse lerarenkamer zal die stelling haastig moeten onderschrijven. Wat is daar in werkelijkheid van waar? Op de Amsterdamse Vrije Universiteit heeft men een landelijk onderzoek naar leerling gedrag verricht. Conclusies: onrustig en impulsief gedrag is aantoonbaar toegenomen, de kinderen zijn sneller afgeleid, tonen minder doorzettingsvermogen en zijn slordiger dan vroeger. Maar er zijn ook pluspunten: de leerlingen hebben tegenwoordig vaak een bredere belangstelling en zijn beter dan hun historische broertje of zusje in staat zelfstandig te werken. Onderzoekster E. Das-Smaal over "de jeugd van vandaag" in de klas