SummaryIntense, sustained nursing lengthens inter-birth intervals and is causally linked with low natural fertility. However, in traditional settings, the effects of such nursing on fertility are difficult to disentangle from those of nutrition. Results from an prospective, direct observational study of reproductive function in well-nourished Amele women who nurse intensively and persistently but who also have high fertility are here presented. Endocrine measures show that ovarian activity resumes by median 11·0 months postpartum. Median duration of postpartum amenorrhoea is 11·3 months, (...) time to next conception is 19·0 months, and the inter-birth interval is 28·0 months. Average life time fertility is 6·8. High fertility in Amele women is due both to refractoriness of reproductive function to suckling stimuli, and to maintenance of equivalent age-specific fertility rates across the reproductive life span. (shrink)

In this paper, we introduce the methodology and techniques of meta-argumentation to model argumentation. The methodology of meta-argumentation instantiates Dung’s abstract argumentation theory with an extended argumentation theory, and is thus based on a combination of the methodology of instantiating abstract arguments, and the methodology of extending Dung’s basic argumentation frameworks with other relations among abstract arguments. The technique of meta-argumentation applies Dung’s theory of abstract argumentation to itself, by instantiating Dung’s abstract arguments with meta-arguments using a technique called flattening. (...) We characterize the domain of instantiation using a representation technique based on soundness and completeness. Finally, we distinguish among various instantiations using the technique of specification languages. (shrink)

OBJECTIVES: To identify the factors that influence the assessment of reported cases of physician-assisted death by members of the public prosecution. DESIGN/SETTING: At the beginning of 1996, during verbal interviews, 12 short case-descriptions were presented to a representative group of 47 members of the public prosecution in the Netherlands. RESULTS: Assessment varied considerably between respondents. Some respondents made more "lenient" assessments than others. Characteristics of the respondents, such as function, personal-life philosophy and age, were not related to the assessment. Case (...) characteristics, i.e. the presence of an explicit request, life expectancy and the type of suffering, strongly influenced the assessment. Of these characteristics, the presence or absence of an explicit request was the most important determinant of the decision whether or not to hold an inquest. CONCLUSIONS: Although the presence of an explicit request, life expectancy and the type of suffering each influenced the assessment, each individual assessment was dependent on the assessor. The resulting danger of legal inequality and legal uncertainty, particularly in complicated cases, should be kept to a minimum by the introduction of some form of protocol and consultation in doubtful or boundary cases. The notification procedure already promotes a certain degree of uniformity in the prosecution policy. (shrink)

Low birth rates in developed societies reflect women’s difficulties in combining work and motherhood. While demographic research has focused on the role of formal childcare in easing this dilemma, evolutionary theory points to the importance of kin. The cooperative breeding hypothesis states that the wider kin group has facilitated women’s reproduction during our evolutionary history. This mechanism has been demonstrated in pre-industrial societies, but there is no direct evidence of beneficial effects of kin’s support on parents’ reproduction in modern societies. (...) Using three-generation longitudinal data anchored in a sample of grandparents aged 55 and over in 1992 in the Netherlands, we show that childcare support from grandparents increases the probability that parents have additional children in the next 8 to 10 years. Grandparental childcare provided to a nephew or niece of childless children did not significantly increase the probability that those children started a family. These results suggest that childcare support by grandparents can enhance their children’s reproductive success in modern societies and is an important factor in people’s fertility decisions, along with the availability of formal childcare. (shrink)

In this introduction to the first installment of the Common Knowledge symposium “Peace by Other Means,” the journal's editor questions the assumptions that underwrite standard approaches in the social sciences to the issue of how non-state, tribal societies have dealt with matters of war and peace. He in particular examines and finds wanting the approach that Jared Diamond takes in The World until Yesterday: What Can We Learn from Traditional Societies?. Whereas Diamond's theme is that modern states can learn much (...) about many things from traditional hunter-gatherer societies, with respect to peacemaking and peace-keeping he finds traditional societies distinctly inferior, and the arguments by which he reaches this conclusion are tautological and also beg the question. This prefatory essay explains that “Peace by Other Means” will analyze and detail non-Western and premodern European means of keeping peace that modern theorists of conflict resolution are reluctant to credit or incompetent to assess. (shrink)

This study aims to contribute to emerging human-robot interaction research by adding longitudinal findings to a limited number of long-term social robotics home studies. We placed 70 robots in users’ homes for a period of up to six months, and used questionnaires and interviews to collect data at six points during this period. Results indicate that users’ evaluations of the robot dropped initially, but later rose after the robot had been used for a longer period of time. This is congruent (...) with the so-called mere-exposure effect, which shows an increasing positive evaluation of a novel stimulus once people become familiar with it. Before adoption, users focus on control beliefs showing that previous experiences with robots or other technologies allows to create a mental image of what having and using a robot in the home would entail. After adoption, users focus on utilitarian and hedonic attitudes showing that especially usefulness, social presence, enjoyment and attractiveness are important factors for long-term acceptance. (shrink)

Introduction: In The Netherlands, physicians have to be convinced that the patient suffers unbearably and hopelessly before granting a request for euthanasia. The extent to which general practitioners (GPs), consulted physicians and members of the euthanasia review committees judge this criterion similarly was evaluated. Methods: 300 GPs, 150 consultants and 27 members of review committees were sent a questionnaire with patient descriptions. Besides a “standard case” of a patient with physical suffering and limited life expectancy, the descriptions included cases in (...) which the request was mainly rooted in psychosocial or existential suffering, such as fear of future suffering or dependency. For each case, respondents were asked whether they recognised the case from their own practice and whether they considered the suffering to be unbearable. Results: The cases were recognisable for almost all respondents. For the “standard case” nearly all respondents were convinced that the patient suffered unbearably. For the other cases, GPs thought the suffering was unbearable less often (2–49%) than consultants (25–79%) and members of the euthanasia review committees (24–88%). In each group, the suffering of patients with early dementia and patients who were “tired of living” was least often considered to be unbearable. Conclusions: When non-physical aspects of suffering are central in a euthanasia request, there is variance between and within GPs, consultants and members of the euthanasia committees in their judgement of the patient’s suffering. Possible explanations could be differences in their roles in the decision-making process, differences in experience with evaluating a euthanasia request, or differences in views regarding the permissibility of euthanasia. (shrink)

About one third of patients with epilepsy have seizures refractory to the medical treatment. Electrical stimulation mapping is the gold standard for the identification of “eloquent” areas prior to resection of epileptogenic tissue. However, it is time-consuming and may cause undesired side effects. Broadband gamma activity recorded with extraoperative electrocorticography during cognitive tasks may be an alternative to ESM but until now has not proven of definitive clinical value. Considering their role in cognition, the alpha and beta bands could further (...) improve the identification of eloquent cortex. We compared gamma, alpha and beta activity, and their combinations for the identification of eloquent cortical areas defined by ESM. Ten patients with intractable focal epilepsy participated in a delayed-match-to-sample task, where syllable sounds were compared to visually presented letters. We used a generalized linear model approach to find the optimal weighting of each band for predicting ESM-defined categories and estimated the diagnostic ability by calculating the area under the receiver operating characteristic curve. Gamma activity increased more in eloquent than in non-eloquent areas, whereas alpha and beta power decreased more in eloquent areas. Diagnostic ability of each band was close to 0.7 for all bands but depended on multiple factors including the time period of the cognitive task, the location of the electrodes and the patient’s degree of attention to the stimulus. We show that diagnostic ability can be increased by 3–5% by combining gamma and alpha and by 7.5–11% when gamma and beta were combined. We then show how ECoG power modulation from cognitive testing can be used to map the probability of eloquence in individual patients and how this probability map can be used in clinical settings to optimize ESM planning. We conclude that the combination of gamma and beta power modulation during cognitive testing can contribute to the identification of eloquent areas prior to ESM in patients with refractory focal epilepsy. (shrink)

The Dutch law states that a physician may perform euthanasia according to a written advance euthanasia directive when a patient is incompetent as long as all legal criteria of due care are met. This may also hold for patients with advanced dementia. We investigated the differing opinions of physicians and members of the general public on the acceptability of euthanasia in patients with advanced dementia.