The effects of pulse stimulation on biota - Research in relation to ICES advice - Effects on dogfish

Onderzoek naar het welzijn van hondshaaien bij de vangst. Er is onderzocht of de methode van het gebruik van stroom wel diervriendelijk is. De conclusie is dat dit geen beletsel voor de diervriendelijkheid oplever

The evaluation of the activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase under different patho-physiological conditions : a combined enzyme histochemical and biochemical approach

This thesis is based on a series of metabolic studies conducted on material obtained from human and experimental animal tissues and cells. The studies are essentially enzyme histochemical complemented when thought necessary with biochemical investigations performed on tissue homogenates of the same material. The human material comprises skeletal muscle biopsies from patients with and without apparent diseases of the neuromuscular system, cardiac muscle specimens obtained through autopsy performances, surgical specimens and cytology material from different organs removed for diagnostic purposes. Skeletal muscle specimens from rats were prepared after the performance of experimental models conducted to induce the desired myopathy after the administration of myotoxic drugs in or without combination with protein synthesis inhibitors, and from rabbits with vitamin E deficiency. The examination for the activity of sometimes more than 20 enzymes belonging to different metabolic pathways, essentially oxidoreductases, hydrolases, transferases and isomerases, was found necessary for a reliable correlation. The results of each experience have already been published or are about to be published separately

De invloed van ouderbetrokkenheid op de schoolprestaties van leerlingen

The relationship between parents and their children's education has been in the public eye for some time. Despite a multitude of scientific studies and initiatives to improve parental involvement in education, there are still gaps in our knowledge about the functioning of parental involvement. This dissertation answers the following main question: to what extent does parental involvement have an effect on the growth in the language and mathematics skills of children in primary and secondary education? Based on a theoretical model, the relationships between forms and influencing factors (determinants) of parental involvement and the growth in school performance of students were investigated. This also includes the mediating effects of different parental involvement forms.Thirdly, the moderating effects of demographic characteristics of parents and children on the relationships found were examined.The results of the study show that the effect of parental involvement seems to be more complicated than current scientific theories suggest. Parental involvement also works differently for primary school pupils than for secondary school students. Finally, it appears that demographic characteristics of parents, such as the level of education and the language they speak with their children at home, can influence the effect of involvement on school performance. So parental involvement does not work the same for parents and children from different backgrounds

Analysis of the angucycline biosynthetic gene cluster in Streptomyces sp. QL37 and implications for lugdunomycin production

Streptomyces bacteria are a valuable source of natural products, many of which are used in the clinic or in biotechnology. In our search for novel antibiotics we discovered lugdunomycin, a natural product with a highly complex chemical architecture that is produced by Streptomyces sp. QL37. It is derived from the angucyclines, a well-known class of molecules known for their antibacterial and anticancer activities. Though angucyclines are produced in high quantities under most conditions, lugdunomycin is produced in minimal amounts. This thesis describes novel insights into the transcriptional control of the lugdunomycin biosynthetic gene cluster and into the lugdunomycin biosynthesis pathway. These insights may be applied to improve the yield of lugdunomycin and expand the chemical diversity of angucyclines. Using molecular biology, bioinformatic approaches and omics studies, such as metabolomics and transcriptomics, we have characterized the lugdunomycin biosynthetic gene cluster, the regulatory genes (lugRI–lugRV) required for transcriptional activation of the cluster, and the oxygenase genes (lugOI–lugOV) that play a key role in the different chemical rearrangements of the angucyclines. Furthermore, this thesis contains a detailed review of the regulatory network that controls antibiotic production in Actinobacteria.Microbial Biotechnolog

Deliverable 2: Report on the production of GIF by turbot, the effects on growth performance of turbot of local GIF production within RAS and the presence of GIF at commercial farm level

One of the working hypotheses of this project is that growth retardation of turbot cultured in recirculating aquaculture systems (RAS) is caused by the accumulation of growth inhibiting factors (GIF) produced by the turbot themselves in the culture water. Our first goal was to demonstrate the production of growth inhibiting factors by turbot following the methodology of Yurl and Perlmutter. A series of successive experiments was performed. Extracts from turbot culture water were tested for GIF presence in early life stage tests using eggs and larvae and small scale growth trials with juveniles. Our second goal was to demonstrate the transfer of GIF between tanks. Four experiments involving the integration of experimental tanks in a farm scale setting were performed. Our third goal was to demonstrate the presence of GIF at commercial farms. Two juvenile growth trials were performed