The origin of marine invertebrate larvae has been an area of controversy in developmental evolution for over a century. Here, we address the question of whether a pelagic “larval” or benthic “adult” morphology originated first in metazoan lineages by testing the hypothesis that particular gene co-option patterns will be associated with the origin of feeding, indirect developing larval forms. Empirical evidence bearing on this hypothesis is derivable from gene expression studies of the sea urchin larval gut of two closely related (...) but differently developing congenerics, Heliocidaris tuberculata (feeding indirect-developing larva) and H. erythrogramma (nonfeeding direct developer), given two subsidiary hypotheses. (1) If larval gut gene expression in H. tuberculata was co-opted from an ancestral adult expression pattern, then the gut expression pattern will remain in adult H. erythrogramma despite its direct development. (2) Genes expressed in the larval gut of H. tuberculata will not have a coordinated expression pattern in H. erythrogramma larvae due to loss of a functional gut. Five structural genes expressed in the invaginating archenteron of H. tuberculata during gastrulation exhibit substantially different expression patterns in H. erythrogramma with only one remaining endoderm specific. Expression of these genes in the adult of H. erythrogramma and larval gut of H. tuberculata, but not in H. erythrogramma larval endoderm, supports the hypothesis that they first played roles in the formation of adult structures and were subsequently recruited into larval ontogeny during the origin and evolution of feeding planktotrophic deuterostome larvae. (shrink)

A July, 1990, controversy in British Columbia, Canada, involved a set of audiotapes detailing an apparent abuse of power by the province's attorney general and a relationship between the attorney general and a member of the press. The controversy was covered extensively in local media. A discussion of relevant ethical issues is followed by an analysis of their coverage in the press. Recommendations are made for more effective handling of ethical issues by media organizations and more meaningful reporting of such (...) issues. (shrink)

This study identified the influences of maternal socio-demographic and antenatal factors on stillbirths and neonatal deaths in New South Wales, Australia. Bivariate and multivariate analyses were used to explore the association of selected antenatal and maternal characteristics with stillbirths and neonatal deaths. The findings of this study showed that stillbirths and neonatal deaths significantly varied by infant sex, maternal age, Aboriginality, maternal country of birth, socioeconomic status, parity, maternal smoking behaviour during pregnancy, maternal diabetes mellitus, maternal hypertension, antenatal care, plurality (...) of birth, low birth weight, place of birth, delivery type, maternal deaths and small gestational age. First-born infants, twins and infants born to teenage mothers, Aboriginal mothers, those who smoked during the pregnancy and those of lower socioeconomic status were at increased risk of stillbirths and neonatal deaths. The most common causes of stillbirths were conditions originating in the perinatal period: intrauterine hypoxia and asphyxia. Congenital malformations, including deformities and chromosomal abnormalities, and disorders related to slow fetal growth, short gestation and low birth weight were the most common causes of neonatal deaths. The findings indicate that very low birth weight (less than 2000 g) contributed 75·6% of the population-attributable risks to stillbirths and 59·4% to neonatal deaths. Low gestational age (less than 32 weeks) accounted for 77·7% of stillbirths and 87·9% of neonatal deaths. The findings of this study suggest that in order to reduce stillbirths and neonatal deaths, it is essential to include strategies to predict and prevent prematurity and low birth weight, and that there is a need to focus on anti-smoking campaigns during pregnancy, optimizing antenatal care and other healthcare programmes targeted at the socially disadvantaged populations identified in this study. (shrink)

This is a clear assessment of Hume's theories of the self and personal identity, including his famous Treatise on Human Nature . Pitson provides a critical exploration of his thinking, also examining the continuing relevance of Hume's theories for contemporary philosophy and relating it to his broader reflections on human nature itself. Divided into two parts, Pitson's study follows Hume's important distinction between two aspects of personal identity: the "mental" and the "agency". The first part discusses Hume's conception of the (...) mind as a "bundle" or "system" of perceptions and explores Hume's position on the traditional mind/body problem. In the second part Pitson examines a range of topics including Hume's treatment of character, the relationship between human and animal nature, and the nature of agency. (shrink)

Both the author and the date of this five-volume poem, the first Western document to link the houses of the zodiac with the course of human affairs, are uncertain. The author's name may be Marcus Manilius, or Manlius, or Mallius, and the latest datable event mentioned in the books themselves is the disastrous defeat of Varus' Roman legions by the German tribes in 9 CE. The writing shows knowledge of the work of Lucretius, but the work is not referred to (...) by any subsequent writer, suggesting that it was never widely disseminated. A manuscript was rediscovered by Poggio Bracciolini in 1416 or 1417, and editions were produced by Scaliger and Bentley, but this immensely erudite edition of 1903–1930 by the scholar and poet A. E. Housman is regarded as authoritative. Volume 4 describes the influence of the zodiacal signs on the people born under them. (shrink)

Both the author and the date of this five-volume poem, the first Western document to link the houses of the zodiac with the course of human affairs, are uncertain. The author's name may be Marcus Manilius, or Manlius, or Mallius, and the latest datable event mentioned in the books themselves is the disastrous defeat of Varus' Roman legions by the German tribes in 9 CE. The writing shows knowledge of the work of Lucretius, but the work is not referred to (...) by any subsequent writer, suggesting that it was never widely disseminated. A manuscript was rediscovered by Poggio Bracciolini in 1416 or 1417, and editions were produced by Scaliger and Bentley, but this immensely erudite edition of 1903–1930 by the scholar and poet A. E. Housman is regarded as authoritative. Volume 3 describes the working out of horoscopes. (shrink)

AT the conclusion of his recently published paper on Corinna1 Professor Page leaves open the question whether the poetess was a contemporary of Pindar or of Moschus-whether she belongs to the middle of the fifth century or the end of the third. He gives excellent reasons for believing that these two dates exhaust the possibilities: they are far more probable than a date either outside or between them; but there seems to be no sure criterion by which we can decide (...) between the two, and Professor Page has to end his researches with a suspension of judgement. (shrink)

OBJECTIVES: To report the outcome of applications to 43 research ethics committees. SETTING: Four regional health authorities in England. FINDINGS: The research ethics committees varied considerably in their practices. The time lapse until notification of the outcome of the approval ranged from just under one week to 23 weeks with a mean of 8.6 weeks. Four research ethics committees failed to notify the research team of an outcome of their request for approval. CONCLUSION: A national research ethics committee is needed (...) to review national and multi-location research studies in the light of the fragmented and variable practice of local research ethics committees. (shrink)