Book reviews

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Book reviews

     

Bacteriochlorophyllgehalt und Proteinmuster der Thylakoide von Rhodospirillum rubrum während der Morphogenese des Photosynthese-Apparates

Zusammenfassung Der Zusammenhang zwischen dem spezifischen Bacteriochlorophyllgehalt der Zellen und der Thylakoidmorphogenese wird an Rhodospirillum rubrum untersucht. Bei der Induktion des Photosynthese-Apparates wird zunächst Bacteriochlorophyll synthetisiert, obgleich noch keine Thylakoide gebildet werden (1. Phase). Werden Thylakoide ausgebildet, so steigt der spezifische Bacteriochlorophyllgehalt der Thylakoide in Abhängigkeit vom spezifischen Bacteriochlorophyllgehalt der Zellen an, bis ein Wert von 12–13 g Bacteriochlorophyll je mg Zellprotein erreicht ist (2. Phase). Während der Wert für die Zellen darüber hinaus weiter erhöht werden kann, bleibt der Wert der Thylakoide konstant bei 100 g Bacteriochlorophyll je mg Thylakoid-Protein (3. Phase). Isolierte Thylakoide aus Zellen mit niedrigem Bacteriochlorophyllgehalt besitzen geringere Durchmesser als Thylakoide aus Zellen mit höheren Werten. Auch hinsichtlich der Zusammensetzung der Thylakoide in Abhängigkeit von den steigenden Bacteriochlorophyllgehalten bei induzierten Zellen konnten Unterschiede festgestellt werden. Ähnlich wie die spezifischen Bacteriochlorophyllgehalte der Thylakoide, nähern sich die verschiedenen Proteinbausteine der Thylakoide einem festen Verhältnis zueinander, das sich oberhalb von 10–14 g Bacteriochlorophyll je mg Zellprotein nicht mehr ändert. Mit Zunahme des Bacteriochlorophyllgehaltes der Zellen steigt der Gehalt an thylakoidspezifischen Proteinen in den Membranen an und der Anteil der für die Cytoplasmamembran spezifischen Komponenten nimmt ab.

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The bacteriochlorophyll content and protein composition of chromatophores (=thylakoids) of Rhodospirillum rubrum during morphogenesis of the photosynthetic apparatus

Summary The correlation between the specific bacteriochlorophyll content of whole cells and the morphogenesis of chromatophores was investigated in Rhodospirillum rubrum. During the first phase after induction of the photosynthetic apparatus bacteriochlorophyll is synthesized without formation of chromatophores. In a second phase chromatophores increases in a linear correlation to the specific bacterichlorophyll content of the cells. In a third phase, when the specific bacteriochlorophyll content of the cells has reached 12–13 g/mg protein, the specific bacteriochlorophyll content of the chromatophores remains constant (100 g/mg protein). Isolated chromatophores from the second phase have smaller diameters, than chromatophores from the third phase. The composition of the protein compounds of isolated chromatophores changes during the development of the chromatophores in a similar fashion as the specific bacteriochlorophyll content of chromatophores does change. With increasing bacteriochlorophyll content of the cells the chromatophore specific proteins in the membranes increase whereas proteins specific for the cytoplasmic membrane decrease until both reach a constant level.

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Verwendete Abkürzungen BChl. Bacteriochlorophyll     

Cell differentiation and pigment composition in Anabaena cylindrica

Summary Cell differentiation in Anabaena cylindrica is accompanied with characteristic changes in the pigment composition of heterocysts and spores. In both the absence of phycocyanin is consistent with the lack of CO₂-fixing ability previously reported. The presence of chlorophyll and -carotene suggests a functional photosystem I in heterocysts. In the spores chlorophyll is largely replaced by pheophytin. The quantitative distribution of carotenoids is also affected. An increase in the proportion of -carotene is characteristic of heterocysts while spores show a larger proportion of xanthophylls compared with the intact filament.     

Lineare Systeme mit gesteuerten statistischen Impulsquellen

Summary From the communication engineers point of view the paper deals with networks consisting of linear filters and a special sort of controlled statistical pulse generators (SIG). The SIG responds to an analog signal with a sequence of Dirac impulses, where the probability for an output impulse at a given time depends on the instantaneous value of the input signal only. In connection with linear filters, however, systems can be realized in which the whole past of the input determines the statistical structure of the output. Therefore systems consisting of linear filters and SIGs (SIG networks) become interesting as models of biological systems, because in biological information processing transformations from analog signals into pulse trains occur very often. An example concerning the application of SIG systems in behavioural sciences will be discussed in a subsequent paper. In the present paper a theoretical analysis of the SIG and SIG networks is carried out by means of Statistical Communication Theory and Theory of Stochastic Processes. It is shown that under certain conditions very complex SIG networks can be treated with Correlation Theory. For one case not satisfying these conditions a solution on the base of Markoff processes is given.

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Auszug aus einer von der Fakultät für Maschinenwesen und Elektrotechnik der Technischen Hochschule München genehmigten Dissertation.Herrn Prof. Dr.-Ing. H. Marko danke ich für das Interesse und die fördernde Kritik während des Entstehens der dieser Arbeit zugrundeliegenden Dissertation. Der Deutschen Forschungsgemeinschaft ist für die finanzielle Förderung der Untersuchungen zu danken. Die numerischen Berechnungen wurden auf der Rechenanlage TR4 des Leibniz-Rechenzentrums der Bayerischen Akademie der Wissenschaften durchgeführt.     

Sterols in species of Pythium

Summary Analysis by gas chromatography revealed the presence of small amounts of squalene, but not lanosterol nor ergosterol in Pythium paroecandrum, P. ultimum, P. graminicola, and P. arrhenomonas. However, when acetate-¹⁴C was used as a precursor for sterols, even squalene was not found in P. graminicola. The deficiency in the sterol synthesizing mechanism may therefore be at or before the squalene forming step. Both squalene and ergosterol were present in the mycelium of Rhizoctonia solani, as shown by both gas chromatography and by the incorporation of acetate-¹⁴C into ergosterol. The absence of ergosterol in Pythium and its presence in Rhizoctonia is consistant with the resistance to the antibiotic filipin of Pythium species and the sensitivity of R. solani.     

Genetische Untersuchungen bei angeborener organischer subvalvulärer Aortenstenose

Zusammenfassung Ausgehend von 45 Probanden mit angeborenen organischen subvalvulären Aortenstenosen wurden Familienuntersuchungen durchgeführt. 29 Probanden hatten eine einfache (isolierte) Subaortenstenose (Tabelle 1), 16 weitere einen mit zusätzlichen Herzdefekten wie angeborener valvulärer Aortenstenose (n=3), Ductus arteriosus persistens (n=7), Aortenisthmusstenose (n=5) und Ventrikelseptumdefekt (n=2) kombinierten Typ (Tabelle 2 u. 3).Die Häufigkeit der angeborenen organischen Subaortenstenose liegt wahrscheinlich zwischen 0,0065% und 0,0162%.Das Geschlechtsverhältnis beträgt bei Zusammenfassung der eigenen Fälle mit Literaturbeobachtungen 2 :1 (Tabelle 3 u. 4).In den Familien der 45 Probanden wurden alle lebenden Eltern, Geschwister sowie Kinder, z. T. auch Großeltern und weitere Verwandte untersucht. In 11 Fällen famden sich in den Sippen weitere Angehörige mit angeborenen Herzfehlern (Tabelle 1 u. 2). In der Geschwisterschaft von Kranken beträgt die nach dem Maximum-likelihood-Verfahren errechnete Erkrankungswahrscheinlichkeit p=0,0361±0,00205 (k=0,^rmin=1). Die Erkrankungswahrscheinlichkeit der Eltern, errechnet nach der Weinbergschen Probandenmethode, beträgt 3,3±1,9% (Tabelle 6).Ein Proband hat einen eineiigen, nicht betroffenen Zwillingsbruder.Das Durchschnittsalter der Väter der Probanden beträgt 30,6 Jahre, das der Mütter 28,6 Jahre und entspricht dem der Kontrollgruppe (Tabelle 7).Die Prüfung der Geburtenordnung nach dem Haldane-Smith-Verfahren ergab keine signifikante Differenz zwischen Beobachtung und Erwartung (Tabelle 8).Genetisch liegt den angeborenen organischen Subaortenstenosen vermutlich ein multifaktorielles genetisches System mit additiver Polygenie und Schwellenwerteffekt zugrunde.

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Genetic investigations in congential organic subvalvular aortic stenosis

Summary Genetic investigations have been carried out on 45 propositi with congenital organic subvalvular aortic stenosis. From these, 29 had an isolated subvalvular aortic stenosis (see Table 1), 16 a type combined with other cardiac defects as valvular aortic stenosis (n=3), patent ductus arteriosus (n=7), coarctation of the aorta (n=5), and ventricular septal defect (n=2) (see Table 2 and 3).The incidence of this heart defect among all live births is probably 0.0065%–0.0162%.According to our own observations as well as to the literature the sex ratio of patients with organic subvalvular aortic stenosis is 2 :1 (see Table 3).In the families of the 45 propositi were examined all living parents, siblings and infants, in some cases also grand-parents and other family members. In all of them 11 relatives were affected with similar or-rarely-dissimilar congenital heart diseases (see Table 1 and 2). Using the maximum-likelihood-method, the risk of siblings to be affected is calculated as beeing p (k=0,^rmin=1). Using the Weinberg method the probability of parents to be affected is 3.3±1,9% (see Table 6).One index patient had a monozygotic co-twin who is not affected.The average age of the fathers is 30.6 years and of the mothers 28.6 years (see Table 7). There is no statistical difference between parental age and that of the control sample.The birth-order effect was examined in our 45 patients (see Table 8) by the Haldane-Smith-method. There is no difference between observation and expectation.The hypothesis of a multifactorial genetic background is supposed as mode of inheritance of congenital organic subvalvular aortic stenosis.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Beobachtungen zur fortpflanzungsbiologie und zum verhalten der geißelspinne tarantula marginemaculata C. L. Koch (Chelicerata,Amblypygi)

The social behaviour of T. m. includes ritualized fights. Sperm transfer is achieved by means of a spermatophore deposited on the ground and by the male pulling the female over it. The behaviour and the spermatophore are described and compared to those of other arachnids and the phylogenetical implications are discussed.     

Microdensitometer system for microradiography

Summary A microdensitometer system for point measurements in areas down to a few square micrometers is described. The detector system is connected to an integrating digital voltmeter, constituting a very sensitive system. The digital output signals and a digital identification are registered on a recorder and on a tape punch, thus facilitating computer analysis.The precision of the equipment varied from 1.1 per cent, for low signal levels, to 0.3 percent for the highest signal levels. Stray light, the only important source of systematic errors, was found to influence the output signal level. Concerning determinations of the densities, however, a variation of the order of 1 per cent was only obtained for small areas with densities differing from that of the background.     

Association between Foeto-maternal Bleeding and Hypertension in Pregnancy

A blind prospective survey of foeto-maternal bleeding in 200 primiparous pregnancies was carried out in an investigation of a possible association between foeto-maternal bleeding and hypertension in pregnancy. Evidence of foeto-maternal bleeding was found in 61% of 36 hypertensive pregnancies, and in 51% of 160 normotensive pregnancies, a difference which is not statistically significant.Significant differences between the hypertensive and the normotensive groups were found when foeto-maternal bleeding was related to gestation. In pregnancies that became hypertensive more foetal cells were found in the maternal circulation before week 36 than in normotensive pregnancies. In patients with oedema of the abdominal wall during pregnancy the incidence of foeto-maternal bleeding was significantly increased.These findings seem to explain why pre-eclamptic toxaemia is a significant predisposing factor in women who later develop Rh antibodies. It is recommended that anti-D gammaglobulin should be offered to all Rh-negative women with Rh-positive infants following a hypertensive pregnancy. Consideration should also be given to the question of administering anti-D gammaglobulin during Rh-negative hypertensive pregnancies if this procedure is proved to be both safe to mother and foetus and effective.The results provide contributory evidence that the placental vascular changes in toxaemic pregnancies precede the clinical signs and are not the result of hypertension.     

Beiträge zur Ökologie des Aphano-Matricarietum Tüxen 1937

Zusammenfassung 1. An Hand von 101 Aufnahmen wird das Aphano-Matricarietum typicum and scleranthetosum im Unteren Eichsfeld in eine typische, eineRanunculus repens-, eineGnaphalium uliginosum-und eineJuncus bufonius-Variante gegliedert.2. Durch Bestimmungen des Bodenwassergehaltes und des pflanzenverfügbaren Wassers sowie durch Berechnung des W-Wertes nachEllenberg wird die Reihe der Varianten als Reihe zunehmender Feuchtigkeit charakterisiert.3. Bei zunehmender Dichte des Getreidebestandes nehmen die dominierenden Unkräuter stark ab, die schwach deckenden Unkräuter dagegen zu.4. Aus den Deckungswerten der soziologischen Tabelle werden Konkurrenzwirkungen zwischenMatricaria chamomilla, Aphanes arvensis undStellaria media belegt.

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Summary 1. In two subassociations of a weed community (Aphano-Matricarietum typicum and scleranthetosum) 101 relevés are used for distinguish three subunits: a var. ofRanunculus repens, ofGnaphalium uliginosum and ofJuncus bufonius.By estimating the water contents and pF values of the soil and by calculating the water figure afterEllenberg this series of subunits is shown to be a series of increasing humidity.2. With increasing density of the cereal grasses, the stronger dominant weeds decrease, while the weaker ones increase.3. A method is described to calculate competition between the dominant weeds from the figures of the sociological relevés. Interactions have been found betweenMatricaria chamomilla at the one side andAphanes arvensis andStellaria media at the other side and vice versa.