Histochemical localization of acid phosphatase and cathepsin-like activities in regressing tails of xenopus larvae at metamorphosis

Zusammenfassung Histochemische Reaktionen an regredierenden Schwänzen von Krallenfroschlarven haben ergeben, dass die saure Phosphatase und die kathepsinartigen Esterasen vorwiegend in Makrophagen des subepidermalen Bindegewebes angereichert sind. Somit dürfte die erhöhte Aktivität dieser Fermente im regredierenden Schwanzgewebe auf der lokalen Aktivierung von Makrophagen beruhen.

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This work was supported by the Swiss National Foundation for Promotion of Scientific Research (Project 1613).     

Conformations and biological properties of apomorphine and its phenanthro(10,1-b,c)azepine homologue.

11,12-Dihydroxy-7-methyl-4,5,6,7,7a,8-hexahydrophenanthro[10,1-b,c]-azepine (2), a homologue of apomorphine (1), has been found to be devoid of dopaminergic effects. The biological differences between apomorphine and this homologue are explained in terms of differences in conformation of the two molecules.     

Microbiology: eukaryotic diversity in Spain's River of Fire

The Rio Tinto, known by the Phoenicians as 'Ur-yero', or 'River of Fire', because of its deep red colour and high acidity, flows through the world's largest pyritic belt in southwestern Spain. Surprisingly, eukaryotic microbes are the principal contributors of biomass in this hostile river, which has a pH of 2 and contains much higher concentrations of heavy metals than are typically found in fresh waters. Here we show that the Rio Tinto shows an unexpected degree of eukaryotic diversity and includes new lineages that we have identified by sequence analysis of genes encoding small-subunit ribosomal RNAs. The diversity of these eukaryotes is much greater than that of prokaryotes, whose metabolism is responsible for the extreme environment.     

Comparison of human genetic and sequence-based physical maps

Recombination is the exchange of information between two homologous chromosomes during meiosis. The rate of recombination per nucleotide, which profoundly affects the evolution of chromosomal segments, is calculated by comparing genetic and physical maps. Human physical maps have been constructed using cytogenetics, overlapping DNA clones and radiation hybrids; but the ultimate and by far the most accurate physical map is the actual nucleotide sequence. The completion of the draft human genomic sequence provides us with the best opportunity yet to compare the genetic and physical maps. Here we describe our estimates of female, male and sex-average recombination rates for about 60% of the genome. Recombination rates varied greatly along each chromosome, from 0 to at least 9 centiMorgans per megabase (cM Mb(-1)). Among several sequence and marker parameters tested, only relative marker position along the metacentric chromosomes in males correlated strongly with recombination rate. We identified several chromosomal regions up to 6 Mb in length with particularly low (deserts) or high (jungles) recombination rates. Linkage disequilibrium was much more common and extended for greater distances in the deserts than in the jungles.     

Civic Meaningfulness: The Political Dimension—A Reply to Lena Dominelli

This article argues, firstly, that voluntary civic practices are not doomed to fall prey to a Big Society rhetoric and a cynical politics of cuts in social spending. It all depends on how these civic practices are promoted and what kind of civic discourse is communicated through the channels of social media and public opinion. Secondly, the author highlights the political importance of connecting meaningfulness with citizenship.     

Seasonal changes of selected secondary plant products in Chrysothamnus nauseosus ssp. turbinatus

Previously, physiological studies of rubber and resin production during the growing season of Chrysothamnus nausceosus ssp. turbinatus indicated a negative correlation between rubber and resin content. The resin was highest in the spring and lowest in the summer, whereas rubber was highest in the summer and lowest in the spring. Individual compounds were followed during the growing season to see if they correlated with the rubber or resin trend. The total compounds in the cyclohexane fraction followed the resin pattern. Individual compounds varied in their changes during the growing season. Limonene, for example, was negatively correlated with rubber production, whereas β cubebene was positively correlated. The possible metabolic pathways between resin and rubber are discussed.