The formation of mature large rRNAs from larger primary transcripts is very different in bacterial and mammalian cells. In both, cotranscription can help to assure the coordinated production of various rRNA species. However, in bacteria, processing is ordered, initiated by cleavages at double‐stranded stems which enclose the mature sequences; several cleavages are required to produce each mature terminus; and the final steps occur in polysomes, apparently linked to continued protein synthesis. In mouse cells, in contrast, cleavages generate nearly all mature (...) termini stochastically and directly, with no evidence for double‐stranded stems as cleavage signals; and processing occurs in the nucleolus, long before any new rRNA chains arrive in polysomes. Spacer sequences also serve different potnetial functions at the evolutionary extremes. In bacteria, transcribed spacer sequences are associated with different secondary structures in the pre‐rRNA compared to the mature rRNA, and these may promote ribosome formation. In mammalian cells, analyses are too premature to assign any comparable function to transcribed spacer sequences, but the non‐transcribed spacers are probably critical in the organization and replication of nucleoli, functions that are absent from bacteria. (shrink)

R.I.G Hughes offers the first detailed and accessible analysis of the Hilbert-space models used in quantum theory and explains why they are so successful.

Group size is a function of relative neocortical volume in nonhuman primates. Extrapolation from this regression equation yields a predicted group size for modern humans very similar to that of certain hunter-gatherer and traditional horticulturalist societies. Groups of similar size are also found in other large-scale forms of contemporary and historical society. Among primates, the cohesion of groups is maintained by social grooming; the time devoted to social grooming is linearly related to group size among the Old World monkeys and (...) apes. To maintain the stability of the large groups characteristic of humans by grooming alone would place intolerable demands on time budgets. It is suggested that (1) the evolution of large groups in the human lineage depended on the development of a more efficient method for time-sharing the processes of social bonding and that (2) language uniquely fulfills this requirement. Data on the size of conversational and other small interacting groups of humans are in line with the predictions for the relative efficiency of conversation compared to grooming as a bonding process. Analysis of a sample of human conversations shows that about 60% of time is spent gossiping about relationships and personal experiences. It is suggested that language evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than is possible by direct observation alone. (shrink)

R.I.G. Hughes presents a series of eight philosophical essays on the theoretical practices of physics. The first two essays examine these practices as they appear in physicists' treatises (e.g. Newton's Principia and Opticks ) and journal articles (by Einstein, Bohm and Pines, Aharonov and Bohm). By treating these publications as texts, Hughes casts the philosopher of science in the role of critic. This premise guides the following 6 essays which deal with various concerns of philosophy of physics such as laws, (...) disunities, models and representation, computer simulation, explanation, and the discourse of physics. (shrink)

It is shown that a formula of modal propositional logic has precisely the same models as a sentence of the first-order language of a single dyadic predicate iff its class of models is closed under ultraproducts. as a corollary, any modal formula definable by a set of first-order conditions is always definable by a single such condition. these results are then used to show that the formula (lmp 'validates' mlp) is not first-order definable.

Act Utilitarianism has traditionally been regarded as the view that you should always perform the action that will bring about the greatest possible excess of happiness over unhappiness or, if there is no such alternative, the least possible excess of unhappiness over happiness.1 Following Rawls, I shall call this the classical principle. An alternative which Rawls calls the average principle is the view that you should always do the thing that will bring about the highest possible average happiness level. Rawls, (...) Rescher and Broad2 regard the average principle as superior to the classical principle, and there are considerable grounds for supposing that Mill accepted the average principle.3 Smart favours the classical position but confesses that if someone doesn't feel the same way, he doesn't know how to argue with him.4. (shrink)

Data on the number of adults that an individual contacts at least once a month in a set of British populations yield estimates of network sizes that correspond closely to those of the typical “sympathy group” size in humans. Men and women do not differ in their total network size, but women have more females and more kin in their networks than men do. Kin account for a significantly higher proportion of network members than would be expected by chance. The (...) number of kin in the network increases in proportion to the size of the family; as a result, people from large families have proportionately fewer non-kin in their networks, suggesting that there is either a time constraint or a cognitive constraint on network size. A small inner clique of the network functions as a support group from whom an individual is particularly likely to seek advice or assistance in time of need. Kin do not account for a significantly higher proportion of the support clique than they do for the wider network of regular social contacts for either men or women, but each sex exhibits a strong preference for members of their own sex. (shrink)

I shall argue here that the reason supererogatory acts are not obligatory is that they require too much personal sacrifice, and that in order for an act to be supererogatory, it must have a kind of result that you would have an obligation to bring about if you could do so with no personal sacrifice. I further argue that traditional utilitarianism should be modified so as not to treat supererogatory acts as obligatory.

The urgency of the research topic is that the attempt, through the prism of higher education in Ukraine, is to outline the factors and opportunities for forming a positive image of a modern teacher as the basis for the competitiveness of a higher educational institution. The purpose of the article is: rethinking the teacher’s image in conditions of growing demands and increasing competitiveness among higher education institutions. The objectives of the study are to summarize the data of the investigated problem (...) and to develop a model for the development of theoretical aspects of forming a teacher’s positive image in the context of the growth of the status of the university, and an analysis of the interdependence of the teacher’s image and his professional competence, practical skills, and the ability to associate theory with practice. The research methodology is general scientific and special-disciplinary methods of scientific research. In particular, the methods of theoretical generalization, analogy and abstraction are used to clarify the conditions, specifics and realities of the modern educational process, in particular – in higher educational institutions; deduction and induction, analysis and synthesis – to identify systemic problems of Ukrainian universities the needs satisfaction of educational services users; the synthesis of progressive ideas on designing ways to enhance the teacher’s positive image in the context of the growth of the status of higher education institutions. Also, special-disciplinary methods of scientific research are used: comparison, systematization and grouping – to generalize the model of development of theoretical aspects of creating of a positive image of the teacher in the context of the formation of the image of the university; analytical – in the analysis of the interdependence of the teacher's image and his professional competence, practical skills and ability to associate theory with practice, etc. The result of the study is a theoretical understanding of the teacher’s image in the context of the formation of the competitiveness of a higher educational institution. The result of the analysis is the constant, systematic improvement of their own professional competencies. And only under this condition, the teacher will be able to rely on the authority and respect among students and colleagues. It is noted that the current state of higher education dictates the necessity of finding new ways of solving problems of increasing the efficiency of not only training, preparation of a specialist in the labor market, but also the efficiency of the activity of a higher educational establishment in conditions of autonomy. Conclusion. The positive image of the teacher, and in general the educational institution, will increase the authority of the professions and specialties of higher education. And philosophy itself should assume responsibility for the formation of the future teacher, since since ancient times, philosophy has been, is and will be the reason for the comprehension of wisdom. The image of a modern teacher largely depends on his professional competence in practical skills and the ability to instruct students to study the theory in close relationship with practice. After all, knowledge becomes effective only in the applied aspect, in particular, when applying the principle of “theory-practice-theory". (shrink)

In my target article, I argued (1) that the relationship between neocortical size and group size in primates implies that there is a cognitive limit on the size of human groups, and (2) that time constraints forced the evolution of language as a more efficient means of bonding the large groups that humans evolved. The doubts about these claims raised by these additional commentaries largely reflect misinterpretation of my original claims.