[Safe prescribing in patients with liver cirrhosis; 5 pitfalls]. / Veilig voorschrijven bij levercirrose: 5 misvattingen.

The liver has a major role in the pharmacokinetics and pharmacodynamics of medicines and hepatic impairment could therefore lead to increased plasma levels and adverse drug reactions. Due to the large overcapacity of the liver, medication adjustments are only needed when a chronic liver disease has progressed to cirrhosis. Important pharmacokinetic alterations that could occur in cirrhosis are: (a) a decreased first-pass effect, (b) impaired metabolism by liver enzymes, and (c) in an advanced stage also impairment of renal elimination. Patients with cirrhosis could also be more sensitive to certain adverse drug reactions at normal drug levels, such as renal impairment due to NSAIDs or the sedative effect of morphinomimetics and psychotropic drugs. Prescribing in patients with cirrhosis is complex, which we illustrate by 5 common pitfalls. In practice, healthcare professionals could use a website with guidance for prescribing almost 300 medicines (www.geneesmiddelenbijlevercirrose.nl).

Women's strategies in polygynous marriage : Kipsigis, Datoga, and other East African cases.

Both behavioral ecological and social anthropological analyses of polygynous marriage tend to emphasize the importance of competition among men in acquisition of mates, whereas the strategic options to women both prior to and after the establishment of a marriage have been neglected. Focusing on African marriage systems that are in some senses analogous to resource-defense polygyny, I first review the evidence of reproductive costs of polygyny to women. Then I discuss why the conflict of interests between men and women over mate number is often likely to be settled in favor of men. Using East African ethnographic data I examine the strategic responses of women and their families to polygynous marriage, focusing on four topics: mate choice (Kipsigis), attitudes toward incoming wives (Kipsigis), labor allocation and cooperation (comparative data, Kipsigis), and use of parental wealth (Datoga). The results of these quantitative analyses suggest that through a combination of judicious marriage choice and strategic responses within marriage, polygyny need not be costly to women in resource-defense polygynous systems. The conclusion is that a hierarchy of questions need to be addressed in the analysis of any polygynous marriage system.

Brothers and sisters : How sibling interactions affect optimal parental allocations.

Data from the Kipsigis of Kenya are used to test two models for how parents invest in offspring, the Trivers-Willard and local resource competition/enhancement hypotheses. Investment is measured as age-specific survival, educational success, marital arrangements, and some components of property inheritance, permitting an evaluation of how biases persist or alter over the period of dependence. Changes through time in such biases are also examined. Despite stronger effects of wealth on the reproductive success of men than women, the survival of sons and daughters is not related to parental wealth. However, a Trivers-Willard effect characterizes educational investment: poor families show a greater concern for daughters' (vis-à-vis sons') schooling than do rich families, a trend that has increased over time. In regard to models of local resource competition and enhancement, men's reproductive success decreases with number of brothers and increases with number of sisters; this pattern of competition with same-sex sibs and cooperation with opposite-sex sibs is not found among women. As predicted from these observations, parents show reduced investment in sons with a large number of brothers, and increased investment in sons with a large number of sisters. By contrast, investment in daughters is entirely unaffected by number of sisters and is influenced only in subtle ways by number of brothers. Levels of investment in relation to sibship size (irrespective of siblings' sex) are highest for younger children of large sib sets.Discussion of the results in relation to those from other studies leads to three conclusions. First, predictive models for how investment biases vary across societies must consider a broad range of socioecological factors constraining parental options and payoffs. Second, the timing of investment biases within societies will be affected by the value of children and the costs of parental investment. Third, measures of investment appropriate for between-sex and between-class comparisons need careful attention. Each of these issues is brought to bear on the question of why, in contrast to so many other parts of the world, sex preferences are so muted in Africa.

Demography of pastoralists: preliminary data on the Datoga of Tanzania.

"Preliminary demographic data are presented on the Datoga, a semi-nomadic pastoral population of northern Tanzania. In comparison with other pastoral populations Datoga fertility is high. There is a marked seasonal distribution of births that is only partly associated with rainfall patterns. Survivorship chances up to the age of 15 are poor, and are independently affected by both length of the preceding interbirth interval and survivorship of the previous child. The results are discussed in the context of ecological and social factors that affect fertility and offspring mortality rates in pastoral populations."

Behavioural ecology in traditional societies.

Can models from behavioural ecology explain cultural diversity in human populations? Studies of variation in reproductive and productive behaviour, both within and between traditional societies, are beginning to show that specific predictions from sexual selection and optimal foraging theory can be developed and tested with human data. Greatest success has been in the study of foraging; whereas attempts to understand patterns of marriage and parental investment have been most convincing in those cases where behaviour is related to specific ecological and social conditions. The aim of human behavioural ecologists in the future will be to determine the constraints that the dual goals of reproduction and production place on individuals.

Resources and reproductive success in women with an example from the Kipsigis of Kenya.

PIP: Contradictory results regarding the relationship between resources and reproductive success of women have led some social scientists to conclude that evolutionary biological models are inappropriate to the study of human social behavior. This paper suggests instead that the variability across societies in this relationship reflects an inadequate specification of the nature and availability of the resources critical to reproduction as well as a failure to understand the mechanisms whereby resources confer reproductive success in traditional, developing, preindustrial, and modern societies. These methodological and conceptual issues are illustrated through use of data on the association between wealth and reproductive success from the Kipsigis, a polygynous agropastoralist population in southwestern Kenya. In this society, land is owned by men, and women gain access to land through marriage. In 3 of the 5 marriage cohorts studied, women with access to larger land plots had higher lifelong reproductive success than their poorer counterparts both in terms of enhanced fertility and survivorship of offspring. This association was independent of confounding factors such as education, age at menarche, husband's age, or occupation. Moreover, wealthy women were found not to make greater use of modern medical child health services when their children were sick than poor women. The Kipsigis data indicate that wealthy women had more nutritional resources than poor women and were able to introduce more suitable weaning foods, leading to a lower incidence of episodes of illness in offspring. Overall, the findings suggest that wealth-related differences in the nutrition and health of mothers and children are important factors in reproductive differentials in Kipsigis society.^ieng

Kipsigis women's preferences for wealthy men: evidence for female choice in mammals?

Factors affecting the choice of a male mate in a polygynous society are examined using data on the Kipsigis people of Kenya. "This paper has two aims: first, to test whether Kipsigis women prefer wealthy men by examining the sequence of marriages among a group of pioneers...who established a settlement in the territory of their enemies (1930-1949); second, to determine whether women suffer reproductively as a result of polygynous marriage."

Erythrocyte antibody screening in solid-phase: a comparison of two solid-phase microplate assays with the indirect antiglobulin test in polyethylene glycol for the detection of irregular erythrocyte antibodies.

The screening of a serum for irregular erythrocyte antibodies in the indirect antiglobulin test is a well-established technique. We compared the test results of two different solid-phase microplate indirect antiglobulin tests with a liquid-phase indirect antiglobulin test in tubes. Antibody screening with both solid-phase microplate techniques proved to be more sensitive than the liquid-phase indirect antiglobulin test. In addition, a difference in sensitivity between the two solid-phase techniques was observed: prior immobilization of test erythrocytes on the microplate followed by incubation with a serum and detection of sensitization with antihuman IgG-coated detector cells gave better test results than secondary immobilization on the microplate of test erythrocytes sensitized with antibodies and an antihuman globulin serum.

Controversies in the evolutionary social sciences: a guide for the perplexed.

It is 25 years since modern evolutionary ideas were first applied extensively to human behavior, jump-starting a field of study once known as 'sociobiology'. Over the years, distinct styles of evolutionary analysis have emerged within the social sciences. Although there is considerable complementarity between approaches that emphasize the study of psychological mechanisms and those that focus on adaptive fit to environments, there are also substantial theoretical and methodological differences. These differences have generated a recurrent debate that is now exacerbated by growing popular media attention to evolutionary human behavioral studies. Here, we provide a guide to current controversies surrounding evolutionary studies of human social behavior, emphasizing theoretical and methodological issues. We conclude that a greater use of formal models, measures of current fitness costs and benefits, and attention to adaptive tradeoffs, will enhance the power and reliability of evolutionary analyses of human social behavior.