Effects of nitrogen,phosphorus and potassium fertilizers on the assimilation capacity ofBeta vulgaris chloroplasts (I)

Summary Aspects of non-cyclic photophosphorylation and NADP photoreduction,viz (a) the effects produced on these processes by the three fertilizer elements: nitrogen, phosphorus and potassium; (b) variations in the catalase activity of reaction mixtures following fertilizer application, and (c) correlations between photosynthesis as measured on leaf-tissue discs and the assimilation capacity of chloroplast suspension, were studied. The role of catalase in the non-cyclic photophosphorylation processes was also studied.While photophosphorylation is influenced chiefly by the level of available soil phosphorus, NADP reduction is affected by all three nutrients. In addition, there was a greater degree of significance, for diagnostic and application purposes, in the values obtained if these two activities were referred to the chloroplast count rather than to the chlorophyll content.Catalase activity, in addition to responding in a different way to the respective fertilizer treatments and, in particular to available soil nitrogen, was governed by the principal constituents of the reaction mixture and in a manner contrary to that of non-cyclic photophosphorylation as measured in terms of oxygen evolution.Experimental findings further showed that photosynthesis is correlated chiefly with NADP-reduction capacity.     

Histochemische Untersuchungen über den Involutionsmechanismus der Milchdrüse

Zusammenfassung Es wurden mit histochemischen Methoden Milchdrüsen von Meerschweinchen in physiologischer und durch Kastration während der Laktationsperiode hervorgerufener Involution untersucht. Nachgewiesen wurden alkalische und saure Phosphatase (APh und SPh), unspezifische Esterase, Sukzinodehydrase, SH-Gruppen, Nukleinsäuren und Lipide. — Die Aktivität der SPh nimmt während der Involution zu. Die Bedeutung dieses Enzyms für den Rückbildungsprozeß des Drüsengewebes wird diskutiert. — Das Vorkommen der APh-Aktivität in Drüsenendstücken im Involutionsstadium kann auf die Beteiligung dieses Enzyms an der Rückresorption der mit der Milch ausgeschiedenen Substanzen hinweisen. — Zwischen der Aktivität der unspezifischen Esterase und dem Gehalt sowie der Lokalisation von Lipiden besteht eine Abhängigkeit. — Es konnten keine Unterschiede in der Sukzinodehydraseaktivität und dem DNS-Gehalt aufgezeigt werden. — Die Verminderung von SH-Gruppen und RNS hängt mit dem Aufhören der Sekretionsproduktion durch die Zellen der Drüsenendstücke der Milchdrüsen zusammen.

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Histochemical studies on the involution mechanism of the mammary gland

Summary Histochemical methods were used to study mammary glands of guinea pigs in the course of physiologic involution and that induced by castration during lactation. Alkaline and acid phosphatases, unspecific esterase, succinic dehydrogenase, SH groups, nucleic acids and lipids were determined. Acid phosphatase activity was found to be increased in mammary glands, subject to involution. The participation of the enzyme in the involutionary process of the gland tissue is discussed. The distribution of alkaline phosphatase in the secretory sections of the gland during involution would suggest the participation of the enzyme in the reabsorption of the substance secreted with milk. A correlation existing between the activity of unspecific esterase, the level and distribution of lipids in the mammary gland could be established. No differences were detected in the activity of succinic dehydrogenase and DNA level. A decrease in SH groups and RNA content is related to cessation of milk secretion.

     

Die wachstumsfördernde Wirkung von Tannin auf Getreidekoleoptilen

Zusammenfassung Schwach konzentrierte Tanninlösungen (5·10^–5 bis 5·10^–8 molar) vermochten das Wachstum 10 mm langer Koleoptilabschnitte von 15 Kulturformen vonAvena sativa, Hordeum distichon, Hordeum vulgare, Zea mays, Triticum aestivum undSecale cereale um etwa 6–25% zu fördern. Die mögliche Beteiligung von Gerbstoffen am Streckungswachstum höherer Pflanzen wurde diskutiert.

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Summary The growth of 10 mm coleoptile sections of 15 cultivars ofAvena sativa, Hordeum distichon, Hordeum vulgare, Zea mays, Triticum aestivum andSecale cereale was stimulated by dilute tannin-solutions (5·10^–5 to 5·10^–8 molar) from 6 up to 25%. The possible role of tannins in elongation growth of higher plants was discussed.

     

Reduction of a Tetrazolium Salt in Determining Growth Activity of Yeast-Phase Histoplasma capsulatum

A colorimetric method using a tetrazolium compound, 3,4,5-dimethylthiozalil-(1 or 2),2,5-diphenyltetrazolium bromide (TTBr), was developed for studying the growth activity of yeast-phase Histoplasma capsulatum. Materials extracted in phosphate buffer, pH 7.0, from cells at different stages of growth reduced TTBr. Colorimetric changes were correlated with enzymatic activity. Under standardized conditions specified herein, the optical density of the reduced tetrazole was an index of the growth activity of the organism.     

About phoma liliana Chandra & Tandon

Summary In vitro,Phoma liliana could not be distinguished from the later-describedP. ehretiae and two incidental isolates fromMangifera andChrysanthemum. Starting from the principle of the classification in the Deuteromycetes, our conclusion is that we must speak of one and the same form-species, which can be found on different plants.     

Studies on several genetic hematological traits of the Mexican population. XII. Distribution of blood group antigens in twelve Indian tribes

Blood samples from 1090 Mexican Indians belonging to the Chol, Chontal, Totonac, Huastec, Mixe, Mazatec, Zapotec, Mixtec, Chinantec, Nahua, Cora and Huichol linguistic groups, were obtained and examined in regard to the following blood group antigens: A, B. M, N, P, C, c, D, E, e, Fy(a), K and Di(a). The gene frequencies were similar to what has been described for other Amerindians; high values for O, M, CDe, cDE and Duffy; low to absent Kell and presence of Diego in variable amounts. The frequency of chromosomes CDE and cDe/cde was somewhat higher than usual and some of the tribes had relatively high frequencies of the A and B antigens. It was felt that variable degrees of non-Indian admixture was at least partially responsible for this situation. A previous study dealing with the distribution of abnormal hemoglobins and glucose-6-phosphate dehydrogenase deficiency in these same tribes, had strongly suggested the possibility of some Negro admixture in the Chontal, Nahua and Cora tribes. However, this was not specifically reflected in their blood group distribution. This served to emphasize the need of investigating as many markers as possible when trying to characterize a population.     

Uraninschwellen des Protoplasmas der BraunalgeStypocaulon scoparium

Ohne Zusammenfassung     

Die Wirkungsweise von Cercosporella herpotricboides Fron, dem Erreger der Halmbruchkrankheit des Getreides

In halt: 1. Einleitung und Aufgabenstellung.—2. Art und Ausmaß der Scnäden im Feld-versuch.—3. Wirkungen des Krankheitserregers auf Sommergetreide.—4. Bekämpfungsmöglichkeiten.—5. Besprechung der Ergebnisse.—Zusammenfassung.—Summary. —Literaturverzeichnis.     

Effect of Drying on Unexposed Autoradiographic Emulsion in Relation to Background

Unexposed blanks prepared from Kodak AR 10 stripping film were dried by 3 methods: (1) fast, open drying with a fan for 25 min, (2) slow drying in a desiccator for 6 hr, and (3) very slow drying in a desiccator for 24 hr. The number of background grains depended on the mode of drying. Fast drying (method 1) gave 0.7 grain per 100 μ², slow drying (method 2) gave 0.33 grain; very slow drying (method 3), only 0.17 grain. The increase of background after fast drying is assumed to be caused by the rapid shrinkage of wet emulsion. This causes an increase in the intraemulsion pressure which, in turn, sensitizes the silver bromide crystals to cause an increase in the number of developable grains.