Comparative evaluation of two superior stopping rules for hierarchical cluster analysis

A split-sample replication stopping rule for hierarchical cluster analysis is compared with the internal criterion previously found superior by Milligan and Cooper (1985) in their comparison of 30 different procedures. The number and extent of overlap of the latent population distributions was systematically varied in the present evaluation of stopping-rule validity. Equal and unequal population base rates were also considered. Both stopping rules correctly identified the actual number of populations when there was essentially no overlap and clusters occupied visually distinct regions of the measurement space. The replication criterion, which is evaluated by clustering of cluster means from preliminary analyses that are accomplished on random partitions of an original data set, was superior as the degree of overlap in population distributions increased. Neither method performed adequately when overlap obliterated visually discernible density nodes.This research was supported in part by NIMH grant 5R01 MH 32457 14.     

A case study of conflicting interests: Flemish engineers involved in environmental impact assessment

This article reports of the activities of the working group, Ethics & Engineers, of the Royal Flemish Society of Engineers. More particularly, the ethical problems that engineers face in the preparation of an environmental report are illuminated. Irrespective to which party the engineer belongs, he or she is confronted with the difficult weighting of his or her personal interest, the interests of private companies and last but not least the common good. It is argued that the implementation of a code of ethics and the introduction of courses on engineering ethics into the education of engineers would strengthen the engineer in the fulfilment of his vocation. Dirk Holemans is a bio-engineer preparing a doctoral thesis on the social responsibility of engineers, Herman Lodewyckx teaches ethics and has research interests in professional and applied ethics.     

Population growth and social structure of confined colonies of mongolian gerbils: Scent gland size and marking behaviour as indices of social status

Male gerbils have larger ventral scent glands, and they mark more than females. In both sexes, scent gland activity is dependent on gonadal hormones. Observations on colonies of gerbils, living in enclosures or cages, showed that both scent gland size and marking behaviour were related to social status. In colonies founded by a single pair, breeding was confined to the original female. The infertility of the daughters was due to failure of sexual maturation. As this was always associated with a lack of development of the scent glands, the functional state of the latter could be used as an index of fecundity. A change in social organization (eg removal of the parents) caused previously infertile females to conceive and was accompanied by development of the scent glands If there was competition for dominance, the scent glands of the losers regressed; at autopsy, their ovaries and uteri appeared to be nonfunctional. The founding father usually had a larger scent gland than his sons, but the inhibition of sexual function was not as severe as in the females. However, the father characteristically showed much more marking behaviow in a neutral territory than his sons. None of the fem ales-except the mother-showed appreciable marking, and her scores were much lower than those of the dominant male. Asymptotic populations were reached at about the same level in enclosures and cages, implicating an intrinsic capacity for control independent of the number of animals per unit of space but probably related to the natural size of a social group. Stabilization of numbers was achieved not only by reproductive inhibition of young females, but also by cessation of breeding by the founding mother and death of litters. Littermates raised in enclosures without their parents showed delayed sexual maturation accompanied by fighting which resulted in the formation of a hierarchy headed by a breeding female and a dominant (marking) male.     

Conflict of interest in medicine in Lithuania: legal and ethical aspects

The current legal framework within the Lithuanian health system is described including a review of the physician’s autonomy, rights and duties, and patients’ rights including the right to reimbursement. The role of ethical codes and the law are discussed. An earlier version of this paper was presented at an International Conference on “Conflict of Interest and its Significance in Science and Medicine” held in Warsaw, Poland on 5–6 April, 2002.     

人口逆淘汰及其预防

对人口逆淘汰必须全面、动态地加以认识.必须阻止人口逆淘汰,提高人口质量,变"人口"为"人力".教育是关键措施,医疗卫生和环境改善十分重要,但决不能鼓励高学历人口多生育而限制农村人口的出生.     

The protective role of higher intellectual functioning on violence in the household population of Great Britain

Despite compelling evidence of the effect of intelligence on delinquency and violent crime, there is limited data on its impact on population violence. We aimed to determine the association of categories of intelligence with violent behaviors in the general population and the extent of the impact of social class on these associations. A randomly selected sample of 14,738 individuals was derived from 2 British national surveys of adults aged 16 years and older. We measured self-reported violent behavior in the past 5 years, including: repetition, injury, violence while intoxicated, familial and extra-familial victim types and intimate partner violence. We examined the moderating role of social class on all outcomes. The increased risk of violence among persons of below average IQ was explained by social class at population level. High IQ had an overall protective effect on all outcomes except violence towards family members, irrespective of socio-economic circumstances. Social class moderated the association of IQ with violence by decreasing its protective effect among those in the lowest socio-economic positions. Our findings suggest that the association of IQ and violence is not linear but protective on population level. Social class has both an explaining and a moderating role in this association.     

In Defense of “Denial”: Difficulty Knowing When Beliefs Are Unrealistic and Whether Unrealistic Beliefs Are Bad

Bioethicists often draw sharp distinctions between hope and states like denial, self-deception, and unrealistic optimism. But what, exactly, is the difference between hope and its more suspect cousins? One common way of drawing the distinction focuses on accuracy of belief about the desired outcome: Hope, though perhaps sometimes misplaced, does not involve inaccuracy in the way that these other states do. Because inaccurate beliefs are thought to compromise informed decision making, bioethicists have considered these states to be ones where intervention is needed either to correct the person’s mental state or to persuade the person to behave differently, or even to deny the person certain options (e.g., another round of chemotherapy). In this article, we argue that it is difficult to determine whether a patient is really in denial, self-deceived, or unrealistically optimistic. Moreover, even when we are confident that beliefs are unrealistic, they are not always as harmful as critics contend. As a result, we need to be more permissive in our approach to patients who we believe are unrealistically optimistic, in denial, or self-deceived—that is, unless patients significantly misunderstand their situation and thus make decisions that are clearly bad for them (especially in light of their own values and goals), we should not intervene by trying to change their mental states or persuade them to behave differently, or by paternalistically denying them certain options (e.g., a risky procedure).     

Knowledge and Concern about STIs/HIV and Sociodemographic Variables Associated with Getting Tested for HIV Among the General Population in Spain

HIV testing is important in terms of prevention and treatment. However, HIV testing rates in the Spanish general population remains low. Therefore, HIV testing promotion constitutes a key issue. A high level of knowledge about HIV/AIDS is associated with having been tested for HIV. The general aim of this study was to determine the prevalence of people who had ever been tested for HIV in Spain. The sample consisted of 1,106 participants from the general population — 60.0% females and 40.0% males — aged between 17 and 55 years old. The assessment instruments were a questionnaire on sociodemographic data and HIV testing, a scale of knowledge about STIs and HIV/AIDS, and a scale of concern about STIs/HIV. Results showed that greater knowledge about STIs and HIV was associated with a greater likelihood of being tested for HIV (OR = .77; 95.0% CI = .73–.82; p < .05). In addition, higher concern about HIV/AIDS decreased the likelihood of not having been tested for HIV (OR = .87; 95.0% CI = .83–.92; p < .05). In fact, the higher participants concern about STIs was, the lower their likelihood of not having been tested for HIV was (OR = .87; 95.0% CI = .83–.91; p < .05). It is necessary to promote HIV testing in the general population as well as to consider their socio-demographic and psychological characteristics.