Time reversal operations,representations of the Lorentz group,and the direction of time

A theory is usually said to be time reversible if whenever a sequence of states S₁(t₁), S₂(t₂), S₃(t₃) is possible according to that theory, then the reverse sequence of time reversed states S₃^T(t₁), S₂^T(t₂), S₁^T(t₃) is also possible according to that theory; i.e., one normally not only inverts the sequence of states, but also operates on the states with a time reversal operator T. David Albert and Paul Horwich have suggested that one should not allow such time reversal operations T on states. I will argue that time reversal operations on fundamental states should be allowed. I will furthermore argue that the form that time reversal operations take is determined by the type of fundamental geometric quantities that occur in nature and that we have good reason to believe that the fundamental geometric quantities that occur in nature correspond to irreducible representations of the Lorentz transformations. Finally, I will argue that we have good reason to believe that space-time has a temporal orientation.     

Structure,function and evolution of haspin and haspinrelated proteins,a distinctive group of eukaryotic protein kinases

The haspins constitute a newly defined protein family containing a distinctive C-terminal eukaryotic protein kinase domain and divergent N termini. Haspin homologues are found in animals, plants and fungi, suggesting an origin early in eukaryotic evolution. Most species have a single haspin homologue. However, Saccharomyces cerevisiae has two such genes, while Caenorhabditis elegans has at least three haspin homologues and approximately 16 haspin-related genes. Mammalian haspin genes have features of retrogenes and are strongly expressed in male germ cells and at lower levels in some somatic tissues. They encode nuclear proteins with serine/threonine kinase activity. Murine haspin is reported to inhibit cell cycle progression in cell lines. One of the S. cerevisiae homologues, ALK1, is a member of the CLB2 gene cluster that peaks in expression at M phase and thus may function in mitosis. Therefore, the haspins are an intriguing group of kinases likely to have important roles during or following both meiosis and mitosis.     

Charles Darwin and group selection

The question of the levels at which natural selection can be said to operate is much discussed by biologists today and is a key factor in the recent controversy about sociobiology. It is shown that this problem is one to which Charles Darwin addressed himself at some length. It is argued that apart from some slight equivocation over man, Darwin opted firmly for hypotheses supposing selection always to work at the level of the individual rather than the group. However, natural selection's co-discoverer, Alfred Russel Wallace, endorsed group selection hypotheses.     

β-Ergokryptine,a new alkaloid of the ergotoxine group

Zusammenfassung Es wird die Isolierung eines neuen Isomeren des Ergokryptins beschrieben, das sich von diesem nur durch den Ersatz des Leucin-Restes durch den Isoleucin-Rest im Peptidteil des Moleküls unterscheidet. Das neue Isomere soll als-Ergokryptin und das früher beschriebene Alkaloid als-Ergokryptin bezeichnet werden. Die beiden Isomeren, ebenso ihre Dihydro-Derivate, unterscheiden sich pharmakologisch nur ganz unwesentlich.

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Mitteilung über Mutterkornalkaloide (65. Mitteilung:H. Ott, A. Hofmann andA. J. Frey, J. Am. chem. Soc.88, 1251 (1966)).     

TRH analogue with C-terminal thioamide group. Synthesis, receptor binding, TSH-releasing activity and alpha-MSH-releasing activity

A new TRH analogue containing a C-terminal thioamide group was synthesized. This peptide was shown to have receptor-binding affinity, and TSH- as well as alpha-MSH-releasing activities very similar to native TRH.     

Challenging Expertise: Paul Feyerabend vs. Harry Collins & Robert Evans on democracy,public participation and scientific authority: Paul Feyerabend vs. Harry Collins & Robert Evans on scientific authority and public participation

This paper compares Feyerabend's arguments in Science in a Free Society to the controversial theory of expertise proposed by Harry Collins and Robert Evans as a Third Wave of Science Studies. Is the legitimacy of democratic decisions threatened by the unquestioned authority of scientific advice? Or does, on the contrary, science need protection from too much democratic participation in technical decisions? Where Feyerabend's political relativism envisions democratic society as inherently pluralist and demands equal contribution of all traditions and worldviews to public decision-making, Collins and Evans hold a conception of elective modernism, defending the reality and value of technical expertise and arguing that science deserves a privileged status in modern democracies, because scientific values are also democratic values. I will argue that Feyerabend's political relativism provides a valuable framework for the evaluation of Collins' and Evans' theory of expertise. By constructing a dialog between Feyerabend and this more recent approach in Science and Technology Studies, the aim of this article is not only to show where the two positions differ and in what way they might be reconciled, but also how Feyerabend's philosophy provides substantial input to contemporary debate.     

K-Lymphocyte cytotoxicity: role of human blood group ABO, rhesus and P alloantibodies]

Using human erythrocytes of known antigenic density, sensitized by ABO and Rhesus (D) alloantibodies, it is shown that K cell cytotoxicity mediated by peripheral blood lymphocytes is directly correlated with the number of IgG molecules specifically bound to the target cell surface. The lytic sensitivity of P1k but not P2 or p erythrocytes coated with anti-Tja (anti-P + P1 + Pk) antibodies, demonstrates that effector K cells are mainly triggered through the IgG ANTI-Pk component of such sera.     

Relationships of the soluble human A, B, and H antigens of blood group A1B individuals

Ouchterlony double diffusion reactions with precipitating antibodies and lectins provide visual evidence that in saliva of A1B secretor individuals the A and B antigens are predominantly situated on the same molecule, while the H antigen is on a different molecule.     

Relationships of the soluble human A,B, and H antigens of blood group A1B individuals

Summary Ouchterlony double diffusion reactions with precipitating antibodies and lectins provide visual evidence that in saliva of A₁B secretor individuals the A and B antigens are predominantly situated on the same molecule, while the H antigen is on a different molecule.     

The chromosomes ofBufo rubropunctatus andBufo chilensis (Anura,Bufonidae) and other species of thespinolosus group

Summary The chromosomes ofBufo rubropunctatus andB. chilensis (on basis of adults) are described for the first time. These chromosomic sets are compared with the karyotypes ofB. spinolosus andB. variegatus and other species ofspinolosus group. The importance of the secondary constrictions applied to the phylogeny ofBufo are discussed.Supported by Proyecto N⁰ S-77-47, Dirección de Investigación, Universidad Austral de Chile.I would like to thank Dr J. M. Cei for collecting the Argentinian toads. Mr N. Diaz collected the specimens from Santiago, Chile.The technical assistence of Sonia Lacrampe is acknowledged with appreciation.     

An adrenergic participation subserving a positive inotropism and chronotropism of prostacyclin on isolated rat atria

Summary The effects of prostacyclin (PGI₂) on the contractile frequency and on the isometric developed tension of spontaneously beating or paced isolated rat atria were explored. PGI₂ enhanced frequency and contractile tension, both effects being blocked by the presence of propranolol, or following a pretreatment with 6-OHDopamine.This work has been supported by Grant 6638 from the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina.     

Ar1-5 and Ar2-6 aryl participation in ionic and free radical processes

Zusammenfassung Die Beteiligung von Arylgruppen in Solvolysen von 4-Aryl-1-butylhalogeniden und Arylsulfonaten sowie in Reaktionen von freien 4-Aryl-1-butyl-radikalen wird diskutiert. Bei geeignet methoxylierten oder hydroxy-lierten 4-Aryl-1-butylverbindungen kann die Formolyse entweder mit Ar₁-5-oder Ar₁-6-Arylbeteiligung verlaufen. Dies führt zur Bildung von Tetralin. Da bei Ar₁-5-Beteiligung ein Spirocarboniumion entsteht, in welchem entweder C oder C der ursprünglichen Butylseitenkette wandern kann, ist es möglich, dass ein anderes Tetralin geformt wird als auf dem direkteren Ar₂-6-Weg. Als Beispiel dient die Formolysenreaktion von 4-p-Anisyl-4-methyl-1-pentylbrombenzolsulfonat.

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Research supported by the Office of Naval Research. — Research sponsored by the Office of Ordnance Research, U. S. Army.