Academic Ceremonies July 2009

“Ranking and Reliable Classification”

In recent years, the storage of digital data in the field of law enforcement has strongly increased. These data have to be analysed to gain new knowledge from them. Therefore, there is a great need for technologies that can computerize the data analysis. Machine learning is a research field within artificial intelligence that provides effective and efficient models for data analysis. The use within law enforcement, however, is not easy because the models are not considered sufficiently reliable. This dissertation conducts research in three promising directions that can lead to a safer process in data analysis.   

Key words:

machine learning, data mining, intelligence led policing

“Robust designs for longitudinal studies”

“ATP infusions in palliative home care”

Patients with cancer in a preterminal stage often experience complaints that can seriously influence the quality of life. This dissertation describes the effects of adenosine 5’-triphosphate (ATP) on these complaints. The results show that in this patient group eight weekly ATP infusions have no effect on the quality of life, physical limitations, fatigue, food intake and body weight, but that they do have an effect on the fat mass. Furthermore, there appears to be small difference in survival in favour of the ATP group, mainly in patients with lung cancer and patients with a stable body weight. However, these findings will have to be confirmed before final conclusions can be drawn.

Trefwoorden:

preterminale kanker, ATP infusen, levenskwaliteit

“Axillary and internal mammary sentinel node biopsy in breast cancer”

“Bootstrapping Nonstationary Time Series”

The analysis of non-stationary time series is an important theme within economics. Many economic time-series, such as Gross national product, exchange rates and share prices are non-stationary; their features change over time. Specific econometric methods are necessary to analyse non-stationary time series. However, these methods appear not always sufficiently reliable in small random samples. The bootstrap is an alternative statistic technique that is often more reliable in small random samples than standard techniques. This dissertation theoretically investigates if the bootstrap can also be used in non-stationary time series. By means of simulations it is shown that the bootstrap is in this context also often more reliable in small random samples than the standard methods. 

Key words:

bootstrap, time series, econometrics

“Retro-nasal aroma release and satiation”

For the prevention or treatment of obesity food should be developed that is tasty, but generates a stronger or more satiated feeling so that people wish to eat less of it. In this context, Ruijschop studied at NIZO food research the role of aroma in satiation mechanisms. Although the degree of aroma release during food consumption is person-specific, this research shows that features of food can be adjusted in such a way that they can lead to a higher quality and/of quantity of aroma-stimulation during food consumption. This can subsequently lead to a stronger feeling of satiation and could ultimately contribute to reduced food intake.

Key words:

obesity, satiation, food, aroma

“Awareness of malnutrition in healthcare”

For years already, malnutrition appears to be a major problem in Dutch health care. Therefore, the quality of food care deserves more attention. This is shown in a dissertation from Judith Meijers. Positive is that annual participation in the National Prevalence Measurement Care Problems (LPZ) leads to lower prevalence figures of malnutrition in hospitals and home care. This means that measuring leads to awareness of the problems and subsequently to activities for improvement. Participation in national care improvement programmes also appears to show results. Furthermore, this dissertation confirms the relation between decubitus and malnutrition and shows that the implementation of food directives for the prevention and treatment of decubitus contributes to more complete decubitus care.

Key words:

malnutrition, health care, decubitus

“Habitual physical activity and food intake regulation; physiological and genetic aspects”

Sufficient physical activity and matching the food intake with the energy use are essential for the preservation of the body weight. This dissertation identified physical and genetic aspects that contribute to differences in physical activity and food intake between people. Persons with a genetic predisposition to a low capacity of converting carbohydrates and fats into energy, turned out less physically active in everyday life. Also, an obesity-associated variant in the FTO gene appeared to be connected with a lower decrease of the hungry feeling after the meal. These results can be used in the future for giving personalized advice to prevent the development of obesity.  

Key words:

obesity, food intake, physical activity, heredity

“The functionality of maternal and neonatal fatty acids”

Some fatty acids are considered to be important for the foetal growth and brain development. Therefore, the unborn child needs many of these fatty acids during the pregnancy. Since the relative quantity of these fatty acids decreases during the pregnancy, this can have consequences for the development of the child. This dissertation studies if fatty acids of the mother and the newborn child are related to foetal learning ability and memory, foetal growth and later immune functions of the child. It also studied the effect of fatty acid consumption in the breast milk period on the fatty acid levels in breast milk. A few conclusions are that, if the found relations are causal, the maternal fatty acid DHA can program the foetal growth in a positive way during the early pregnancy. The maternal fatty acids AA and DGLA may be involved in foetal growth limitation during the late pregnancy.  

Key words:

fatty acids, pregnancy, foetus, newborn, learning ability and memory, birth results, immune functions, breast milk

“Supersizing Science; on building large-scale research projects in biology”

Biological research expands because of increasing cooperation between scientists. In her dissertation Supersizing Science Niki Vermeulen describes this process. Besides the well-known Human Genome Project three other major research networks are analysed: a worldwide research into life in the oceans, the building of a virtual cell and the search for an influenza vaccine. Large scientific projects have important consequences for the way in which science is conducted. The way a scientific project is organized demands more and more attention. Vermeulen calls this ‘projectification of science’. Scientists have to behave increasingly as managers and entrepreneurs. Especially the next generation of scientists will be confronted with this.  

Key words:

biology, science, entrepreneurship