An intrinsic feature of the mating type (MT) system of Schizosaccharomyces prombe is the occurrence of specific mutations from homothallism to heterothallism and vice vers. The authors report on two ...mutants of S. pombe with as yet unknown properties.
The Zeeman effect in strong magnetic fields Kapitza, P.; Skinner, Herbert Wakefield Banks
Proceedings of the Royal Society of London. Series A, Containing papers of a mathematical and physical character,
09/1925, Letnik:
109, Številka:
749
Journal Article
Odprti dostop
From the time of Zeeman’s discovery, the Zeeman effect has been the subject of a large amount of work; but hitherto experiments have been limited by the fields obtainable with an electro-magnet. It ...is known that the strongest field which can be obtained with the largest practicable electro-magnet is about 80,000 gauss. On account of the necessity in Zeeman effect experiments for uniformity of the field over a considerable volume, no experiments seem to have been performed in fields stronger than 40 or 50,000 gauss. In a recent paper a method has been described by which considerably stronger fields may be produced. The general principle is to obtain the field by passing a large current through a coil (without iron) for a very short time; so that the coil has no time to heat up. The current is produced by short-circuiting a specially constructed accumulator battery through the coil, and in this way it is possible to use a power of 1,000 k. w. A field of strength up to 500 k. g. may be obtained in a very small volume; but for the study of the Zeeman effect, it has only been found possible to use fields of strength up to 130,000 gauss, since we must have the field uniform over a reasonable volume in which to place our source of light.
Male infertility is common. It usually is attributable to impaired maturation of germinal cells. The causes are related to the following factors: 1. Defective development of the gonadal ridge; 2. ...Abnormality of chromosomes; 3. Disorders in pituitary function; 4. Exogenous effects; 5. Unknown aetiology. -- Differentiation is difficult between those causes which often cannot be discovered at all. Therefore, assessment of male infertility is undertaken with reference to findings obtained from seminal, histological, immunological, cytogenetic, and hormonal tests as well as from electron microscopy.
Von den neurohormonalen Faktoren des Nervensystems verschiedener Arthropoden (Insekten, Krebse) lassen sich mittels sorgfältiger Trennungsverfahren neben den Neurohormonen fluoreszierende Substanzen ...isolieren: Isoxanthopterin, Xanthopterin und 2-Amino-6-hydroxypteridin. Es wird gezeigt, daß die Neurohormone mit den fluoreszierenden Pterinen nicht identisch sind.
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