Effects of bone marrow transplantation on impacted dental germs in osteopetrotic op/op rats

The osteopetrotic op/op rats suffered from a complete failure of tooth eruption in association with a reduced bone resorption. An unresorbed occlusal bone overlaid the germs which remained embedded in bone. The process of prefunctional eruption in limited growing teeth depends on the resorption of the alveolar bone covering the germs. The aim of this study was to investigate the effects of hematopoietic grafts in newborn op/op rats on the process of prefunctional eruption. Fifteen op/op treated rats were used for radiographic, microradiographic and histologic examinations. After transfusion of bone marrow cells, we observed the restoration of bone resorption and a delayed eruption of the molars. The incisors never erupted. They developed odontome-like tumors near their apices. These results confirm the dependence of tooth eruption on bone resorption.SCOPUS: ar.jFLWNAinfo:eu-repo/semantics/publishe

Evaluation of a Eel-trap Sampling Method for the Assessment of Migrant Yellow Eels Anguilla anguilla (L.) in the River Meuse

peer reviewedA sampling methodology using modified eel traps (100 x 40 cm Ø) installed in fish passes was evaluated for the assessment of migratory yellow eel Anguilla anguilla stock and population structure in the Belgian River Meuse in 1993. Up to 248 eels (mean size : 292 mm) were captured in a single trap immersed overnight. In a standardized context, the size of the sample captured in the trap was highly predictive (R = 0.998 ; 2 4 df) of the number of eels migrating through the fish pass. The eel traps were evaluated as non selective towards fish size within the size range of yellow eels (114 - 614 mm). The delay for checking the eel traps (2 min) fits the purpose of frequent and numerous samples. Applying this «point migration sampling» methodology on a large scale would allow a reliable assessment of yellow eel migration dynamics in regulated rivers like the River Meuse

Intertidal deposits: river mouths, tidal flats, and coastal lagoons

Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons combines the authors personal and professional experience with the mass of available literature to present a cohesive overview of intertidal deposits and the widely diverse conditions of their formation worldwide. This includes the strong influence of water movements, climate, sediment particle characteristics, vegetation, fauna, and man. Intertidal areas are important for many reasons both scientifically and economically and recently, a growing concern for conservation of these fragile regions strives to preserve and protect their natural balance. This book, written by an international expert in the field, concentrates on the more important intertidal areas distinguished by size and morphology, tidal range, the degree and type of vegetational cover, the amount and type of benthic fauna, the extent of human exploitation, and the degree of previous study. Discusses the more important intertidal areas, subdivided by tidal range. Includes a series of chapters on the morphology of intertidal areas (including channels and creeks), the composition and structures of intertidal sediments, the processes of sediment transport, deposition and erosion, and the influence of intertidal flora and fauna. Presents separate sections on benthic fauna and microflora, saltmarshes, mangroves, and algal mats and seagrasses. Addresses the influence of man on existing intertidal areas. Provides a short chapter on the Holocene history of intertidal areas