A note on the use of protease inhibitors during chromatin fractionation on hydroxyapatite columns

Summary It was found that NaHSO₃ present in the eluents enabled full and reproducible recovery of chromosomal proteins from a hydroxyapatite column. Another protease inhibitor PMSF, did not have that effect.     

Comparative fractionation of DNA from ascites tumour and normal cells on hydroxyapatite column

Zusammenfassung Zwischen DNS normaler und neoplastischer Zellen besteht ein wesentlicher biochemischer Unterschied.     

Gel filtration of protease inhibitors from potatoes

Zusammenfassung Vorläufige Fraktionierung an Dextran-Gel Sephadex G-25 (Pharmacia, Uppsala) ergab eine Trennung des Proteaseinhibitors aus Kartoffeln in die einzelnen Komponenten, die neben der eigentlichen entzündungshemmenden Aktivität noch Antitrypsin- bzw. Antichymotrypsin-, Antiplasmin- und ausgeprägte Hämagglutinierungsaktivität aufwiesen.     

A cautionary note on pentacyanoammonioferrate use for determining L-canavanine occurrence in biological materials

Summary Caution must be taken in the prevelant use of the pentacyanoammonioferrate reagent for the detection of L-canavanine in biological materias. This reagent reacts with L-histidine at neutral pH to form a pentacyanoammonioferate-histidine complex that is mistaken readily for its canavanine-containing counterpart.This work was supported by a grant from the National Science Foundation (PCM-78-20167). This is publication number 81-7-199 of the Kentucky Agriculatural Experiment Station, Lexington     

A note on the prehistory of indistinguishable particles

In modern terms, quantum statistics differs from classical statistics for the indistinguishability of its elementary entities. An historical investigation of the emergence of Bose–Einstein statistics, however, shows that quantum statistics was initially interpreted as a statistics of non-independence, for it extended to gas particles the statistical correlation that was a long-recognized characteristic of light quanta. At the same time, the development of a quantum–statistical theory of the ideal gas was riddled with the question of the statistical significance of the exchange symmetry of a system of equal particles. Indistinguishability combines exchange symmetry and statistical correlation, and relates them to the loss of identity of particles in quantum mechanics. It is instructive, however, not to conflate these properties when analysing the historical emergence of quantum statistics. The statistical correlation of light quanta and the exchange symmetry of gas molecules remained two separate problems even though quantum gas theory and Bose–Einstein statistics were born from gas-radiation analogies in statistical theory.     

A note on solutions governing the origin of polytropes

Zusammenfassung Es wird bewiesen, dass für den Ursprung von Polytropen nur Lösungen derEmden-Gleichung vom Index 0 oder — 1 sind.     

A note on diagrams for turning-point diagnostics

A new diagram for discriminating a forecasting technique's history with respect to the two types of turning-point errors, missed turns and false signals is presented. This diagram extends Theil's original prediction-realization (P-R) presentation so that each of the four quadrants and the axes locates a distinct type of forecasting error or correct forecast, thus reducing much of the former ambiguity. This improvement is accomplished without the loss of any information.     

A note on the mechanism of theMarchi reaction in degenerating myelin

Zusammenfassung Behandelt man degenerierendes Myelin gleichzeitig mit derSwank-Davenport-Lösung und Triton X 100, so wird dieMarchi-Reaktion, die gewöhnlich durch dieSwank-Davenport-Lösung ausgelöst wird, im wesentlichen verhindert. Dies stimmt mit früheren Befunden überein. Das Ergebnis deutet darauf hin, dass diese Verhinderung durch Triton X 100 aus der Löslichkeit des normalerweise unlöslichen Kaliumchlorats in degenerierendem Myelin resultiert.     

A note on the mechanism of action of UV-irradiation of amphibian embryos

Summary The actions on amphibian embryos of UV-irradiation, exposure to Li⁺ or exposure to ouabain show interesting parallels with their effects on spontaneous release at the presynaptic terminals of the neuromuscular junction. It is suggested that these treatments serve to raise intracellular Ca²⁺ ([Ca²⁺ _i) in these examples, and that UV-promoted abnormalities in embryogenesis are a consequence of changes in [Ca²⁺]_i at critical stages in development.     

A note on the mechanism of action of UV-irradiation of amphibian embryos

The actions on amphibian embryos of UV-irradiation, exposure to Li+ or exposure to ouabain show interesting parallels with their effects on spontaneous release at the presynaptic terminals of the neuromuscular junction. It is suggested that these treatments serve to raise intracellular Ca2+ ([Ca2+]i) in these examples, and that UV-promoted abnormalities in embryogenesis are a consequence of changes in [Ca2+]i at critical stages in development.     

A note on the fowler's solution of the lane-emden equation of index 3

Zusammenfassung FürFowler's Lösung der Lane-Emden-Gleichung von Index 3 wird der Gültigkeitsbereich erweitert.     

A rapid method for the fractionation of avian blood cell nuclei

Summary Red blood cell nuclei from avian anaemic blood have been fractionated by rate sedimentation on discontinous sucrose gradients into fractions which can be distinguished both by their RNA synthesizing ability and by their morphology as revealed by electron microscopy.Acknowledgment. We wish to thank H. Gitay for the electron micrographs. This work was supported by grants from the University of Cape Town Research Committee and the Council for Scientific and Industrial Research.     

A note on the evolution of the transducer mechanism of the vertebrate retinal rod

Summary The Ca²⁺-gating mechanism that is the key component of membrane excitability in Paramecium has recently been localized on the cilia of this animal. Such a finding shows how the change in Ca²⁺ permeability (which is the probable consequence of the photoisomerization of rhodopsin) of the discs of the outer segments of the retinal rods could have evolved.