Academic Ceremonies December 2010

“Essays on Economies with Heterogenous Interacting Consumers”

The current thesis is concerned with the importance of including consumer interaction in theoretical models for deriving aggregate implications. 
Applications discussed include advertising and R&D policies. The thesis demonstrates that changes in structure and intensity of consumer interaction can drastically change the behaviour of demand. 

Key words:

consumer interaction, theoretical models, advertising, R&D policies

“Barrett’s esophagus and esophageal and gastric cancer subtypes: an epidemiologic perspective”

Esophageal cancer occurs more and more, but what are the risk factors for this disease? Results on the basis of the Dutch Cohort Study on nutrition and cancer that has been conducted since 1986 among over 120.000 persons show that smoking increases the risk of esophageal and gastric cancer. Alcoholic beverages are a risk for one type of esophageal cancer (squamous cell carcinoma), while overweight increases the risk of another type of esophageal cancer (adenocarcinoma). The study once again confirmed that eating many vegetables and fruits is healthy: it lowers the risk of esophageal and gastric cancer. Furthermore, the micro-nutrient selenium may possibly protect against esophageal cancer and one type of gastric cancer (cardia cancer).

Key words:

esophageal cancer, risk factors, nutrition, alcohol

“Risk attitudes in a social environment”

This dissertation studies by means of economic experiments the effect of the social environment on the risk behaviour of individuals in risky situations, such as pandemia outbreaks, receiving or not receiving a donor liver, terrorism threat, but also for example participating in a lottery. The social environment in itself appears not to have a great influence on the risk behaviour of an individual. However, it this person fulfils the role of social planner and has to decide how risks will be dispersed over the social environment (for example determining who is entitled to a donor liver, or who is or isn’t admitted to a medical study programme), he has a strong preference for procedures that apply to everyone and where fate determines the allocation. But as soon as the level of the risk is determined by a social environment they can choose themselves, people will sooner make risky, but efficient choices that ultimately decrease the risk. An example of this is the proposition by Chancellor Angela Merkel to place countries with an unhealthy national financial system out of the European Union. The threat of exclusion will force the EU countries to better watch over their financial system, which lowers the risk of another Euro crisis. 

Key words:

economic experiment, risk behaviour, social environment, choice behaviour

“Recidive in België en Nederland. Een analyse van 200 jaar rechtspraak en rechtsleer”

“Between family and friends: understanding the interdependence of private transfers”

“The adolescent brain: neurocognitive development and subject-related factors”

This dissertation studies how the brain functioning develops during thinking functions in adolescents. Adolescents of respectively 13, 17 and 21 years old largely activate the same brain areas when, for example they make decisions. However, the degree to which de brain areas are active increases when the young person grows older. These brain changes occur dispersed in the brains and they are not specific for a certain thinking function. They indicate a general development principle in the functioning of the brains. Moreover, this research shows considerable individual changes between adolescents; gender and the experienced stress in the scanner influence thinking functions and brain activity. These research findings are important for the way we look at adolescents. In the educational system, for example, it is assumed that high-school students are quite capable of independent working, whereas this PhD research shows that this ability is still in development during adolescence.  

Key words:

adolescents, development, brains

“Gastrointestinal targets to modulate satiety and food intake”

Diets that contain a relatively high level of proteins are regarded an effective treatment for weight control. Particularly for the prevention of weight increase after a period of weight loss. So far, it is not known whether it makes a difference which specific proteins are used in these diets. This dissertation studies which proteins have the greatest effect on a feeling of hunger and food intake. It turns out that proteins from peas have the greatest effect. It also turned out that inhibition of the decomposition of this protein in the stomach even increases the effect. Obese men ate less after they had been administered pea protein directly in the intestines, than after they had eaten this protein. These results can contribute to new perspectives in the treatment of overweight and obesity.

Key words:

diets, proteins, feeling of hunger, food intake 

“Exploiting tumour and lung heterogeneity with radiotherapy”

In the current lung cancer treatment with radiotherapy, the entire tumour is treated with the same quantity of radiation. However, there are indications that certain parts of a tumour are more aggressive and need a higher radiation dose to be cured than other parts.  This dissertation studied the possibilities of focusing the radiation dose more specifically on the most aggressive part of the lung tumour. The research shows that the effectiveness of the treatment could increase with 30% without increasing the side-effects. The dissertation also shows how can be determine how much radiation dose the aggressive  parts need and how can be monitored if the radiation dose is administered to the right location. It also turns out that some parts of the normal lungs are extra sensitive for radiation and that the dose to specifically these parts should be limited as much as possible. It is emphasised that the results should be confirmed in further research.

Key words:

lung cancer, radiotherapy, dose of radiation

“Celbiologie van thrombose en hemostase: de trombus”

“To buy or not to buy: Empirical studies on Buyer-Supplier Collaboration”

Buying companies that want to have a better access to a supplier’s critical resources than competition need to develop close social relationships with this supplier’s employees. This is the outcome of a study by Agnieszka Blonska. This research is one of the first to demonstrate a close social relationship between buyer and supplier companies’ employees has a positive influence on supplier allocation of preferences among buyers, supplier and buyer customization, and cross-functional information sharing behavior of buyers and suppliers. The research was conducted from both, supplier and buyer perspectives.

Key words:

social relationship employees, customization

“Neurophatic pain: glial responses and plasticity in the spinal nociceptive network”

“Physical activity recognition using a wearable accelerometer. New perspectives for energy expenditure assessment and health promotion”

A physically active lifestyle is important for living a healthy life. However, defining how much physical activity is necessary for promoting health requires objective and valid instruments for monitoring physical activity and the related physiological outcomes. This thesis showed that accurate recognition of physical activity types, like walking, cycling, and running was feasible using a wearable accelerometer. This method improved daily estimations of energy-expenditure, and it showed that the cycling-, walking- and sitting daily duration determined the subjective activity level. Furthermore, specific activity types characterizing the behavior of obese subjects played a key role for protecting against cardiovascular diseases.

Key words:

physical activity, accelerometer

“Algebraic polynomial system solving and applications”

The problem of calculating the solutions of a system of polynomial contrasts can be approached by means of an algebraic method that remodels the problem into a large eigenvalue problem. This method is the starting point for the development of computational procedures for the two applications that are at the centre of this dissertation:
(i)  The global optimization of a polynomial function in several variables, and
(ii) the model-order reduction problem for reductions of size one, two or three.

Key words:

polynomial contrasts

“Mood and Motivation in Parkinson’s disease”

“Genetic background and impact of Staphylococcus aureus in a cross-border region”

MRSA (the hospital bacteria) occurs more in Belgian and German hospitals in the Euregion Meuse-Rhine than in Dutch hospitals. The ‘Search & Destroy’ policy of the Dutch government has – in spite of the high cost – realized containment of the MRSA contaminations in hospitals. Via genetic research this dissertation shows that several MSRA variants have dispersed to the Dutch patient population. Because there are many cross-border movements by patients between hospitals, and new ‘variants’ of the MRSA bacteria occur, the MRSA containment policy between the hospitals in the Euregion Meuse-Rhine should be matched to prevent transfer of MRSA between patients. 

Key words:

MRSA, cross-border, Euregion Meuse-Rhine

“MR Imaging of coronary atherosclerosis”​

“Risks and recommendations in WRULD”

Mouse arms, currently no longer called RSI, but WRULD (work-related upper limb disorders), still occur frequently and involve high costs. Physiotherapy and posture therapy show insufficient results, even in the case of incipient complaints. At the origin of WRULD stressful situations and a perfectionist are important factors. When the complaints persist, the way a person experiences his complaints and perceives them as a psychological burden plays an important role. Risk factors such as a perfectionist mentality and anxiety, among others pain anxiety causing the avoidance of activities deserve more attention. 
Therefore, in the treatment of WRULD, guidance by a psychologist (for perfectionist persons) and a behaviour therapist (for people with anxiety) should be included. Moreover, sports are important for WRULD patients. Fit persons experience fewer complaints. 

Key words:

mouse arm, WRULD, treatment

“Coronary heart disease in the Netherlands: Incidence, etiology and risk prediction”

Diseases of the coronaries, such as a heart infarct, cause a high disease burden in the Netherlands. This dissertation describes how often these diseases occur and how they are connected to various risk factors. Also, a risk score was developed that can predict the risk that a person will have a heart disease with fatal or not-fatal effect within the next ten years. This risk is calculated on the basis of his or her risk factors. Based on such a score can be decided to give lifestyle advice or start a treatment in order to lower the risk of a heart disease for this person.

Key words:

diseases of the coronaries, incidence, risk factors, risk score

“Veni, Vidi, da Vinci”

“Imaging of carotid atherosclerosis”

“Pax6 in Mammalian degenerative retina”

“Paratonia enlightened; definition, diagnosis, course, riskfactors and treatment”

“Polyethylene Wear in Total Hip Arthroplasty”

“Surgery for knee osteoarthritis: outcome measurements and their clinimetric implications”

 "Solving Difficult Game Positions"

"New horizons in lymph node imaging in head and neck cancer"

“Toxicogenomic Responses to N-Nitroso Compound Exposure in Relation to Human Colorectal Cancer Risk”

This research shows that a diet with much red meat leads to changes in the gene activities in the intestines that can increase the risk of colorectal cancer. This can explain why the intake of red meat has been connected with the development of colorectal cancer for years already. Assumed was that red meat would increase a Group of substances, called nitrosamines, in the intestines and that these substances would subsequently influence the gene activity. This turns out not to be the case: red meat does not increase the formation. The present nitrosamines, however, did cause carcinogenic changes in the gene activity, but these changes can not directly be attributed to eating red meat. 

Key words:

cancer, colorectal cancer, red meat, nitrosamines, N-nitroso compounds

"Perceived cognitive problems in Young-old adults: contextual factors, assessment and intervention"

“Molecular imaging of biologic characteristics and drug uptake”

“Veneuze Pathologie in Beeld”

“An inconvenient deliberation: The Precautionary Principle’s Contribution to the Uncertainties Surrounding Climate Change Liability”

The thesis’ focus is on a legal perspective on the interdisciplinary problem of Climate Change in terms of the responsibility and the liability for damage, which results from the activities of multiple actors. In an integrative, problem‐oriented manner, the book scrutinizes how scientific uncertainties translate into legal uncertainties in a liability claim over the damaging consequences of Climate Change. In this context, it analyzes how the Precautionary Principle, a principle aimed at making uncertainty manageable, can help to overcome some of the legal obstacles in such a claim, whilst, at the same time, potentially creating new liabilities. The book advocates for a consistent application of the principle, taking due account of its flexible interpretation in both public and private decision-making, and in judicial appreciation in Climate Change liability cases.

Key words:

climate change, liability, uncertainty, precautionary principle

“The role of the skeletal muscle in early-stage metabolic syndrome”

The muscle plays an important role in the development of the metabolic syndrome (metabolic disease due to an imbalance between eating and exercising). The worldwide increase of the metabolic syndrome is caused by high-fat food. This dissertation describes the effect of high-fat food on the muscle by molecular changes at the gene, protein and fat metabolite level. High-fat food causes molecular changes in the muscle that indicate an increase of the capacity of the fat metabolism. By actually measuring the fat metabolism the molecular changes were confirmed. These findings show how molecular research can be successfully integrated with more applied research.

Key words:

metabolic syndrome, muscle, high-fat food

“The role of dairy products and constituents in metabolic risk management”

The metabolic syndrome is a combination of various risk factors for cardiovascular diseases. In this project, we studied the effects of dairy products on these risk factors in test persons with overweight.  In the long term, it turns out that consumption of semi-skimmed dairy products lowers the systolic blood pressure, but has no positive effects on other risk factors. In the long term, milk has negative effects on the fat content in the blood directly after a meal, but positive effects on the glucose level. Further research will have to show if these findings also apply to other dairy products, other quantities, or other populations.

Key words:

dairy products, metabolic risk factors, metabolic syndrome

“Het persoonlijke genoom: het begin van een nieuw tijdperk in de gezondheidszorg”

“Manipulability, Decomposability, and Rationalizability”

Social choice theory, as the name suggests, deals with techniques for finding an alternative for a society respecting their preferences over the set of alternatives. Of course, such a technique must satisfy some desirable properties such as strategy-proofness and unanimity. Strategy-proofness ensures that the individuals can not be better off by misrepresenting their true preferences, whereas unanimity implies that if all agents report the same preference, then the rule selects the top of that common preference. However, the classic results of Gibbard (1973) and Satterthwaite (1975) have shown that if we allow for all possible preferences of the individuals then the only rule that satisfies these properties is the dictatorial one. As all the non-dictatorial rules are manipulable, the natural question arises, which one is least manipulable, i.e., manipulable at minimum number of profiles. Furthermore, this impossibility result leaves another question open as to whether in a more restricted context rules other than dictatorships can be strategy-proof. We address these two fundamental questions in this research.

Key words:

social choice theory, strategy-proofness

“Paternal Exposure to benzo(a)pyrene; a genetic risk in offspring?”

Each day we are exposed to substances that are dangerous for the environment that influence our health and possibly the health of our offspring.  Benzo(a)pyrene, for example, is formed by the combustion of organic materials, such as wood, diesel and tobacco. Research has already shown that benzo(a)pyrene can cause DNA mutations and consequently cancer. This dissertation describes the DNA-damaging effects of benzo(a)pyrene in testes and male reproductive cells of mice and shows that benzo(a)pyrene can cause germinal line mutations in spermatogonial stem cells of mice. Transferral of these mutations on the offspring may increase the risk of diseases, such as cancer, at a young age. Future research will have to show whether benzo(a)pyrene causes germinal line mutations in humans.

Key words:

benzo(a)pyrene, DNA damage, mutations, germinal line

“The Institutional Transformation of social policy in east central Europe: Poland and Hungary in comparative and historical perspective”

“Human resource management practices and learning for innovation in developing countries: Pharmaceutical firms in Mexico”