Desmosomes are junctions involved in intercellular adhesion of epithelial cells and hemidesmosomes are junctions involved in adhesion of epithelia to basement membranes. Both are characterised at the ultrastructural level by dense cytoplasmic plaques which are linked to the intermediate filament cytoskeleton of the cells. The plaques strongly resemble each other suggesting a relationship between the two kinds of junctions, as implied by their names. Recent characterisation of the molecular components of the junctions shows they are, in fact, quite unrelated implying (...) that structural similarity is fortuitous. The molecular biology raises many fascinating problems relating to their structure and function. (shrink)

"By combining recent advances in the physical sciences with some of the novel ideas, techniques, and data of modern biology, this book attempts to achieve a new and different kind of evolutionary synthesis. I found it to be challenging, fascinating, infuriating, and provocative, but certainly not dull."--James H, Brown, University of New Mexico "This book is unquestionably mandatory reading not only for every living biologist but for generations of biologists to come."--Jack P. Hailman, Animal Behaviour , review of the first (...) edition "An important contribution to modern evolutionary thinking. It fortifies the place of Evolutionary Theory among the other well-established natural laws."--R.Gessink, TAXON. (shrink)

Currently, an emphasis is being placed on the integration of ethical issues into the business curriculum. This paper investigates the viability of using student group interaction to induce an upward movement in the stages of moral development as advanced by Kohlberg. The results of a classroom experiment using graduate business law students suggest that formulating groups that mix stages of moral development can provide a robust environment for upward movement. In addition, the results suggest strategies for formulating effective groups, based (...) upon entry levels as measured by the Defining Issues Test. (shrink)

Ethical guidelines for conducting clinical trials have historically been based on a perceived therapeutic obligation to treat and benefit the patient-participants. The origins of this ethical framework can be traced to the Hippocratic oath originally written to guide doctors in caring for their patients, where the overriding moral obligation of doctors is strictly to do what is best for the individual patient, irrespective of other social considerations. In contrast, although medicine focuses on the health of the person, public health is (...) concerned with the health of the entire population, and thus, public health ethics is founded on the societal responsibility to protect and promote the health of the population as a whole. From a public health perspective, research ethics should be guided by giving due consideration to the risks and benefits to society in addition to the individual research participants. On the basis of a duty to protect the population as a whole, a fiduciary obligation to realise the social value of the research and the moral responsibility to distribute the benefits and burdens of research fairly across society, how a public health perspective on research ethics results in fundamental re-assessments of the proper course of action for two salient topical issues in research ethics is shown: stopping trials early for reasons of efficacy and the conduct of research on less expensive yet less effective interventions. (shrink)

One of the arguments against conducting human subject trials in the Third World adopts a distributive justice principle found in a commentary of the CIOM'S Eighth Guideline for international research on human subjects. Critics argue that non-participant members of the community in which the trials are conducted are exploited because sponsoring agencies do not ensure that the products developed have been made reasonably available to these individuals. I argue that the distributive principle's wording is too vague and ambiguous to be (...) used to criticize any trial. Furthermore, the mere fact that an experiment does not fulfill this particular distributive justice principle does not entail that it is unethical. (shrink)

A number of authors have drawn attention to the contributions to geology of Robert Hooke, and it has been pointed out that in several ways his ideas were more advanced than those of Steno, who is sometimes taken to be the founder of geology as a scientific discipline. Moreover, it has been argued that in a number of instances Hooke should receive the credit for ideas which are usually believed to have originated in the work of James Hutton. This recognition (...) of the significance of Hooke's work is regarded by the present writer as being well founded. But, by contrast, the relationship between Hooke's geological ideas and his views on the proper methods for conducting scientific enquiries has been largely overlooked, and his views on the methodology of science, as revealed in his Posthumous works, have received little discussion. Moreover, on one of the few occasions on which they were discussed, by William Whewell, they were belittled. Whewell regarded Hooke's methodological contribution as merely ‘an attempt to adapt the Novum organon to the age which succeeded its publication’, 5 and he implied that the ‘same imperfections’ were to be found in the writings of both Hooke and Bacon. The influence of Bacon is, to be sure, most obvious in Hooke's general philosophy. Nevertheless, it will be argued that Hooke had a much clearer idea than did Bacon of the importance of so-called ‘hypothetico-deductive’ methods in science, and that in many ways his methodological views represent a significant advance on those of Bacon. (shrink)

D. R. Bell; XI—Imperatives and the Will, Proceedings of the Aristotelian Society, Volume 66, Issue 1, 1 June 1966, Pages 129–148, https://doi.org/10.1093/aristo.

SummaryEarly geological investigations in the St David's area (Pembrokeshire) are described, particularly the work of Murchison. In a reconnaissance survey in 1835, he regarded a ridge of rocks at St David's as intrusive in unfossiliferous Cambrian; and the early Survey mapping (chiefly the work of Aveline and Ramsay) was conducted on that assumption, leading to the publication of maps in 1845 and 1857. The latter represented the margins of the St David's ridge as ‘Altered Cambrian’. So the supposedly intrusive ‘syenite’ (...) was regarded as younger, and there was no Precambrian. These views were challenged by a local doctor, Henry Hicks, who developed an idea of the ex-Survey palaeontologist John Salter that the rocks of the ridge were stratified and had formed a Precambrian island, round which Cambrian sediments (now confirmed by fossil discoveries) had been deposited. Hicks subsequently proposed subdivision of his Precambrian into ‘Dimetian’, ‘Pebidian’, and (later) ‘Arvonian’, and he attempted correlations with rocks in Shropshire, North Wales, and even North America, seeking to develop the neo-Neptunist ideas of Sterry Hunt. The challenge to the Survey's work was countered in the 1880s by the Director General, Geikie, who showed that Hicks's idea of stratification in the Dimetian was mistaken. A heated controversy developed, several amateur geologists, supported by a group of Cambridge Sedgwickians, forming a coalition of ‘Archaeans’ against the Survey. Geikie was supported by Lloyd Morgan. Attention focused particularly on Ogof Lle-sugn Cave and St Non's Arch, with theory/controversy-ladenness of observations evident on both sides. Evidence from an eyewitness student record of a Geological Society meeting reveals the ‘sanit`ized’ nature of the official summary of the debate in QJGS. Field mapping early in the twentieth century by J. F. N. Green allowed a compromise consensus to be achieved, but Green's evidence for unconformity between the Cambrian and the Dimetian, obtained by excavation, can no longer be verified, and his consensual history of the area may need revision. Unconformity between the Cambrian and the Pebidian tuffs is not in doubt, however, and Precambrian at St David's is accepted. The study exhibits features of geological controversy and the British geological community in the nineteenth century. It also furnishes a further instance of the great influence of Murchison in nineteenth-century British geology and the side-effects of his controversy with Sedgwick. (shrink)

D. R. Fisher; IV*—Why Should I Be Just?, Proceedings of the Aristotelian Society, Volume 77, Issue 1, 1 June 1977, Pages 43–62, https://doi.org/10.1093/aristote.

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R. Renehan's ingenious solutions to the problems of Symphosius 42. 1 and Anth. Lat. 207 in this journal, 471 f.) are much to be welcomed. On the other hand, I do not think that his defence of the manuscript reading in Anth. Lat. 24. 3 marcent post rorem violae, rosa perdit odorem holds water. Taking rorem as = rorem marinum he explains that ‘the poet is not presenting us with a piece of botanical information about the relative seasons of the (...) violet and rosemary; he means rather that all flowers wither and fade’. Actually, however, the poet on this showing does present information; and whether the information is botanically correct or not, that is an odd way to make his point. Stranger still is his choice of rosemary out of all the fading flowers of field and garden. It was bound to be I misunderstood. As Renehan indicates, ros = ros marinus is supported only by Virg. Georg. 2. 212–13, where the identity has been doubted, and Plin. HN 24. 100, where ex rore supra dicto refers back to ros marinum in 99. Renehan may well be the first reader not to take rorem as dew. And an evergeen shrub makes a singularly unfortunate illustration of floral decay, even though the shrub does produce a flower. Pliny classes it with herbs. (shrink)

Notice is given of the discovery of two reports and an accompanying manuscript map by Andrew Ramsay, on the geology of the St David's area, Pembrokeshire. This adds to previously published information on early geological work in this important region: Ramsay's report throw some light on his attitude towards Murchison's ideas on Welsh stratigraphy. The map is the earliest known version of the Survey's St David's sheet.

‘In spite of the efforts of scholars to improve matters, the condition of Seneca's text remains in many places most uncertain or quite irrecoverable. Again and again one has to be content with conjectures which, while often giving the general sense of a passage, must not be taken as certainly Seneca's words’ . 1. praef. 5 o quam contempta res est homo, nisi supra humana surrexerit! quam diu cum affectibus colluctamur, quid magnifici facimus, etiam si superiores sumus? portenta vincimus: quid (...) est cur suspiciamus nosmet ipsos, quia dissimiles deterrimis sumus? Traditional punctuation: ‘… quid magnifici facimus? etiam si superiores sumus, portenta vincimus’. (shrink)

The main theoretical issues in the study of the history of the Archaean Controversy in Britain, which arose in the first three papers of the present series, are summarized and discussed—in particular the problem of stratigraphical work in rocks where no fossils can be discerned. The ‘Archaean’ geologists showed some leanings towards Neo-Neptunism and this, together with the fact that their work challenged the Murchison/Survey view of British geology, was one of the reasons for the controversy. At a deeper level, (...) however, the question concerned the doctrine of uniformitarianism: Were metamorphic rocks to be found at any part of the stratigraphical column, or were they confined to the earliest period of the Earth's history? The establishment of the concept of Precambrian rocks and a suitable stratotype boundary is essentially a social question that has to be determined within the geological community. Some of the social processes whereby these matters are decided internationally are considered, and it is noted that the best location of the ‘Golden Spike’ for the Precambrian/Cambrian boundary has only just been settled . The paper also explores some nineteenth-century ideas about the nature of metamorphism, and the early conditions of the world. (shrink)

An account is given of early geological researches in the Malverns, the Church Stretton area, and the Wrekin. The reconnaissance work of Murchison suggested that each of these areas had Silurian sediments, intruded by igneous rocks . The early Survey maps were compiled on this theoretical basis, with the result that the Silurian sediments were regarded as the oldest rocks in Shropshire and the Malverns. Local geologists, working in the three areas, and with sufficient time to study the exposures in (...) detail, began to develop the idea of ‘islands’ of Precambrian rock , having younger sediments deposited thereon. This Archaean model was taken up and actively developed, and the stratigraphical details worked out, with the island model being gradually modified. Debates were stronger between members of the ‘Archaean’ fraternity than with the Survey. Traces of trilobite remains were found by Callaway at Comley, near Caer Caradoc, and were identified by Lapworth as Olenellus, enabling the underlying Wrekin Quartzite to be established as the base of the Cambrian, in agreement with ideas developed in North America and Scandinavia. Arguments are detailed concerning the relative ages of the ‘Uriconian’ and ‘Longmyndian’ rocks, and their constituent units. Both were agreed to be Precambrian, but the evidence in terms of field mapping, in relation to the Wrekin Quartzite, is not complete. The problems of stratigraphical work in unfossiliferous rocks are displayed, and also the efforts to achieve correlations with areas such as Pembrokeshire and Anglesey are described. Though consensus has been reached on the Precambrian status of the Malvernian, Uriconian and Longmyndian rocks, radiometric age determinations and other evidence throw doubt on some aspects of the consensus, and research continues. (shrink)

A detailed account is given of the development of the Archaean Controversy in Caernarvonshire and Anglesey. Sedgwick had found no base for his Cambrian in North Wales, but had intimated that some of the unfossiliferous rocks of the Lleyn Peninsula and Anglesey might be older than his Cambrian. He also described two ‘ribs’ of igneous rock: one running from Caernarvon to Bangor; the other inland, parallel to the first and crossing the Llanberis Pass at Llyn Padarn. The early Surveyors supposed (...) that these ‘ribs’ had altered the surrounding rocks, and the resulting ‘Altered Cambrian’ could be traced across the Menai Strait to Anglesey, where it formed the various metamorphic rocks of that island. This view was challenged by the usual coalition of ‘amateurs’ with attempts being made to recognize a sequence of Archaean rocks in North Wales similar to that in Pembrokeshire. However, vigorous debate occurred amongst the ‘Archaean’ geologists themselves, especially about a rock at Twt Hill, Caernarvon, and about a claimed unconformity at the base of the Cambrian in the Llanberis Pass, perhaps adjacent to the Llyn Padarn ‘rib’. Vigorous debate took place about the location of the claimed Llanberis unconformity, but the ‘Archaeans’ were united in regarding the metamorphic rocks of Anglesey as Precambrian. Eventually, the greywackes of Anglesey, and around Bangor and Caernarvon, were identified as Ordovician, not Cambrian. Very detailed map-work in Anglesey was carried out privately by Edward Greenly, and his results were published by the Survey in the form of a map and a high-quality Memoir. Greenly utilized for Anglesey tectonic ideas derived from his earlier fieldwork in the Scottish Highlands, so that although his mapping and stratigraphical divisions have proved to be of permanent value it is believed that his structures for Anglesey were mistaken and his stratigraphic sequence inverted. The Survey eventually abandoned its earlier model of Anglesey without too much difficulty; and the igneous ‘rib’ of Llyn Padarn is now construed as an ignimbrite. However, a definite base for the Cambrian has still not been found in Caernarvonshire, and the stratigraphical evidence for the Precambrian age of the Anglesey rocks remains incomplete. The study reveals the great difficulty experienced by early geologists when working in unfossiliferous rocks, the evidence from included fragments proving particularly uncertain. The paper also examines further the community of nineteenth-century British geologists, with their various factions and competing interests. (shrink)