Maastricht University

About: Maastricht University is a education organization based out in Maastricht, Limburg, Netherlands. It is known for research contribution in the topics: Population & Health care. The organization has 19263 authors who have published 53291 publications receiving 2266866 citations. The organization is also known as: Universiteit Maastricht & UM.

Intervention mapping: protocol for applying health psychology theory to prevention programmes

Abstract: Evidence-based health promotion programmes are based on empirical data and theory. While a broad range of social and behavioural science theories are available, the actual application of these theories in programme design remains a real challenge for health promotion planners. Intervention Mapping describes a protocol for the development of theory- and evidence-based health promotion programmes. It provides guidelines and tools for the selection of theoretical foundations and underpinnings of health promotion programmes, for the application of theory, and for the translation of theory in actual programme materials and activities. This article presents the protocol and elaborates on the application of theory, using examples from successful intervention programmes.

A new approach for the determination of ventilatory and lactate thresholds.

Abstract: In order to determine the ventilatory threshold (VT) and the lactate threshold (LT) in a reliable way, a new method is proposed and compared with conventional methods. The new method consists of calculating the point that yields the maximal distance from a curve representing ventilatory and metabolic variables as a function of oxygen uptake (VO2) to the line formed by the two end points of the curve (Dmax method). Male cyclists (n = 8) performed two incremental exercise tests a week apart. Ventilatory/metabolic variables were measured and blood was sampled for later lactate measurement during each workload and immediately after exercise. No statistical differences were observed in the threshold values (expressed as absolute oxygen uptake; VO2) determined by the Dmax method and the conventional linear regression method (according to O2 equivalent; EqO2) and venous blood at the onset of blood lactate (OBLA), while VT assessed with the conventional linear method (according to the slope of CO2 output; Vslope) yielded significantly lower threshold values. Similar results were obtained from the reproducibility test. Thus, the Dmax method appears to be an objective and reliable method for threshold determination, which can be applied to various ventilatory or metabolic variables yet yield similar results. The results also showed that breathing frequency can be used to determine VT.

Serotonergic vulnerability and depression: assumptions, experimental evidence and implications.

Abstract: In recent years, the term serotonergic vulnerability (SV) has been used in scientific literature, but so far it has not been explicitly defined. This review article attempts to elucidate the SV concept. SV can be defined as increased sensitivity to natural or experimental alterations of the serotonergic (5-HTergic) system. Several factors that may disrupt the 5-HTergic system and hence contribute to SV are discussed, including genetic factors, female gender, personality characteristics, several types of stress and drug use. It is explained that SV can be demonstrated by means of manipulations of the 5-HTergic system, such as 5-HT challenges or acute tryptophan depletion (ATD). Results of 5-HT challenge studies and ATD studies are discussed in terms of their implications for the concept of SV. A model is proposed in which a combination of various factors that may compromise 5-HT functioning in one person can result in depression or other 5-HT-related pathology. By manipulating 5-HT levels, in particular with ATD, vulnerable subjects may be identified before pathology initiates, providing the opportunity to take preventive action. Although it is not likely that this model applies to all cases of depression, or is able to identify all vulnerable subjects, the strength of the model is that it may enable identification of vulnerable subjects before the 5-HT related pathology occurs.

European Mutual Fund Performance

Abstract: This paper presents an overview of the European mutual fund industry and investigates mutual fund performance using a survivorship bias controlled sample of 506 funds from the 5 most important mutual fund countries. The latter is done using the Carhart (1997) 4-factor asset-pricing model. In addition we investigate whether European fund managers exhibit "hot hands", persistence in performance. Finally the influence of fund characteristics on risk-adjusted performance is considered. Our overall results suggest that European mutual funds, and especially small cap funds are able to add value, as indicated by their positive after cost alphas. If we add back management fees, 4 out of 5 countries exhibit significant out-performance at an aggregate level. Finally, we detect strong persistence in mean returns for funds investing in the United Kingdom. Our results deviate from most US studies that argue mutual funds under-perform the market by the amount of expenses they charge.