Biomedical subjects

H Aarts

Publications and source records attributed to H Aarts.

7 recordsLinked to original sources

PubMed2004

The relevance of gene transfer to the safety of food and feed derived from genetically modified (GM) plants.

In 2000, the thematic network ENTRANSFOOD was launched to assess four different topics that are all related to the testing or assessment of food containing or produced from genetically modified organisms (GMOs). Each of the topics was linked to a European Commission (EC)-funded large shared cost action (see http://www.entransfood.com). Since the exchange of genetic information through horizontal (lateral) gene transfer (HGT) might play a more important role, in quantity and quality, than hitherto imagined, a working group dealing with HGT in the context of food and feed safety was established. This working group was linked to the GMOBILITY project (GMOBILITY, 2003) and the results of the deliberations are laid down in this review paper. HGT is reviewed in relation to the potential risks of consuming food or feed derived from transgenic crops. First, the mechanisms for obtaining transgenic crops are described. Next, HGT mechanisms and its possible evolutionary role are described. The use of marker genes is presented in detail as a special case for genes that may pose a risk. Furthermore, the exposure to GMOs and in particular to genetically modified (GM) deoxyribonucleic acid (DNA) is discussed as part of the total risk assessment. The review finishes off with a number of conclusions related to GM food and feed safety. The aim of this paper is to provide a comprehensive overview to assist risk assessors as well as regulators and the general public in understanding the safety issues related to these mechanisms.

Animal Feed↗

PubMed2001

On the psychology of drinking: being thirsty and perceptually ready.

The present research is concerned with cognitive effects of habitually regulated primary motives. Specifically, two experiments tested the idea that feelings of thirst enhance the cognitive accessibility of, or readiness to perceive, action-relevant stimuli. In a task allegedly designed to assess mouth-detection skills, some participants were made to feel thirsty, whereas others were not. Results showed that participants who were made thirsty responded faster to drinking-related items in a lexical decision task, and performed better on an incidental recall task of drinking-related items, relative to no-thirst control participants. These results suggest that basic needs and motives, such as thirst, causes a heightened perceptual readiness to environmental cues that are instrumental in satisfying these needs.

Drinking Behavior↗

PubMed2001

Determinants of adaptive behavior among older persons: self-efficacy, importance, and personal dispositions as directive mechanisms.

Successful aging calls for effective adaptation, which in turn implies flexible use of coping strategies to optimize personal functioning and well-being. The present paper studied adaptive choice behavior of older, independently living persons faced with complications in their houses. The goal was to gain insight into the concrete coping process and its outcome-in terms of the choice of assimilative vs. accommodative strategies-and in the role of three determinants on this process. The determinants were perceived self-efficacy, importance of the problem, and personal dispositions (flexibility and tenacity). A sample of 199 independently-living older persons participated in an experiment that was based on a scenario and questionnaire method, with problems stemming from the domain of independent living. Results mainly underlie the crucial role of perceived self-efficacy and are discussed in view of the concept of successful aging.

Activities of Daily Living↗

PubMed2000

Habits as knowledge structures: automaticity in goal-directed behavior.

This study tested the idea of habits as a form of goal-directed automatic behavior. Expanding on the idea that habits are mentally represented as associations between goals and actions, it was proposed that goals are capable of activating the habitual action. More specific, when habits are established (e.g., frequent cycling to the university), the very activation of the goal to act (e.g., having to attend lectures at the university) automatically evokes the habitual response (e.g., bicycle). Indeed, it was tested and confirmed that, when behavior is habitual, behavioral responses are activated automatically. In addition, the results of 3 experiments indicated that (a) the automaticity in habits is conditional on the presence of an active goal (cf. goal-dependent automaticity; J. A. Bargh, 1989), supporting the idea that habits are mentally represented as goal-action links, and (b) the formation of implementation intentions (i.e., the creation of a strong mental link between a goal and action) may simulate goal-directed automaticity in habits.

Adult↗

PubMed1998

COMPTEL measurements of the omnidirectional high-energy neutron flux in near-earth orbit.

On four occasions, twice in 1991 (near solar maximum) and twice in 1994 (near solar minimum), one COMPTEL D1 detector module was used as an omnidirectional detector to measure the high-energy (> 12.8 MeV) neutron flux near an altitude of 450 km. The D1 modules are cylindrical, with radius 13.8 cm and depth 8 cm, and are filled with liquid scintillator (NE213A). The combined flux measurements can be fit reasonably well by a product of the Mt. Washington neutron monitor rate, a linear function in the spacecraft geocenter zenith angle, and an exponential function of the vertical geomagnetic cutoff rigidity in which the coefficient of the rigidity is a linear function of the neutron monitor rate. When pointed at the nadir, the flux is consistent with that expected from the atmospheric neutron albedo alone. When pointed at the zenith the flux is reduced by a factor of about 0.54. Thus the production of secondary neutrons in the massive (16000 kg) Compton Gamma-Ray Observatory spacecraft is negligible. Rather, the mass of the spacecraft provides shielding from the earth albedo.

Astronomy↗

PubMed1998

Habit versus planned behaviour: a field experiment.

A field experiment investigated the prediction and change in repeated behaviour in the domain of travel mode choices. Car use during seven days was predicted from habit strength (measured by self-reported frequency of past behaviour, as well as by a more covert measure based on personal scripts incorporating the behaviour), and antecedents of behaviour as conceptualized in the theory of planned behaviour (attitude, subjective norm, perceived behavioural control and behavioural intention). Both habit measures predicted behaviour in addition to intention and perceived control. Significant habit x intention interactions indicated that intentions were only significantly related to behaviour when habit was weak, whereas no intention-behaviour relation existed when habit was strong. During the seven-day registration of behaviour, half of the respondents were asked to think about the circumstances under which the behaviour was executed. Compared to control participants, the behaviour of experimental participants was more strongly related to their previously expressed intentions. However, the habit-behaviour relation was unaffected. The results demonstrate that, although external incentives may increase the enactment of intentions, habits set boundary conditions for the applicability of the theory of planned behaviour.

Adult↗

PubMed1997

Physical exercise habit: on the conceptualization and formation of habitual health behaviours.

An observation one can make when reviewing the literature on physical activity is that health-enhancing exercise habits tend to wear off as soon as individuals enter adolescence. Therefore, exercise habits should be promoted and preserved early in life. This article focuses on the formation of physical exercise habits. First, the literature on motivational determinants of habitual exercise and related behaviours is discussed, and the concept of habit is further explored. Based on this literature, a theoretical model of exercise habit formation is proposed. More specifically, expanding on the idea that habits are the result of automated cognitive processes, it is argued that physical exercise habits are capable of being automatically activated by the situational features that normally precede these behaviours. These habits may enhance health as a result of consistent performance over a long period of time. Subsequently, obstacles to the formation of exercise habits are discussed and interventions that may anticipate these obstacles are presented. Finally, implications for theory and practice are briefly discussed.

Adolescent↗