Idiosyncratic evolution of conserved eukaryote proteins that are similar in sequence to archaeal or bacterial proteins

	Sequence comparisons have been made between the proteins of 571 prokaryote species including 46 archaea and 525 bacteria and the set of human proteins. Highly conserved eukaryotic proteins are often strikingly similar in sequence to archaeal and bacterial proteins. Yet in many cases similarity to archaeal proteins is not correlated to the similarity to bacterial proteins. In these comparisons there are hundreds of eukaryote proteins that match well archeal proteins, but do not match recognizably to bacterial proteins, while thousands of proteins match well to bacterial proteins but not recognizably to archeal proteins. Forty percent of the 21,440 human proteins that significantly match prokaryote proteins are in this extreme idiosyncratic category. These relationships have been preserved over billions of years since the last common ancestor or sharing of protein genes between prokaryotes and eukaryotes. For each of the 21,440 members of this set of human proteins (that make significant matches to any of the 1.8 million proteins in this set of prokaryote species protein libraries) it is certain that each protein has important functions both in prokaryotes and eukaryotes and the precursor proteins have been important in the precursor species of both. That is the only explanation for the preservation of amino acid sequence similarity for the billions of years since the last common ancestor or period of sharing of proteins. Comparisons were made between the proteins of Arabidopsis thaliana and Saccharomyces cerevisiae to the proteins of the 571 prokaryote species. The results agreed with the human comparisons indicating that the conclusions apply to eukaryotes generally

Message from the president

As an institution committed to civil interchange about the important topics of our time, we believe that discourse, no matter how passionate, can and must be conducted with reason and respect because we also celebrate those values as inherently important to our community

The quantum mechanical theory of collisions

textLecture notes by Roy Glauber, Department of Physics, Harvard University. Cours professe a l'Ecole d'ete de physique theorique. Les Houches, Haute-Savoie, FranceEcole d'ete de physique theorique. Les Houches, Haute-Savoie, FrancePhysic

Message from the president

As an institution committed to civil interchange about the important topics of our time, we believe that discourse, no matter how passionate, can and must be conducted with reason and respect because we also celebrate those values as inherently important to our community

Antibiotic prescribing by general dental practitioners in the Greater Glasgow Health Board, Scotland

OBJECTIVE: To investigate antibiotic prescribing patterns by general dental practitioners (GDPs) in the Greater Glasgow Health Board Area, Scotland. STUDY DESIGN: A 10% sample of prescriptions were selected at random from 35,545 prescriptions written by GDPs over a 6-month period. MAIN OUTCOME MEASURES: Absolute and relative frequencies were used to describe the different classes of antibiotics used and the variations in prescribing practice. RESULTS: GDPs prescribed a wide range of antibiotics. Seventeen different antibiotics were prescribed with amoxycillin, metronidazole and penicillin V accounting for almost 90% of the prescriptions. In general the antibiotics were prescribed at the British National Formulary (BNF) recommended doses. There were, however, wide variations in the frequencies and durations of the prescriptions for all antibiotics. CONCLUSIONS: The present study provides evidence of sub-optimal prescribing of antibiotics by dentists in Scotland, with considerable variation from the recommended frequencies and doses

Externalities, markets, and government policy

Before the work of Ronald Coase, economists argued that externalities-unpriced benefits or costs-constituted the main exception to the rule that Adam Smith's invisible hand will efficiently allocate resources. Coase showed that externalities may or may not require a government solution, depending on the institutional setting of the problems and the size of transaction costs. Moreover, even in the absence of externalities, market transactions require low transaction costs. Firms exist to economize on those costs. In shifting the terms of the debate, Coase single-handedly moved economics from presuming specific roles for government action to a more neutral position requiring detailed analysis. In this article, Roy Ruffin explains Coase's contribution to understanding the role of government.Expenditures, Public