Arrest of somatic cells at G2 by Sevin (pesticide)

Summary The treatment of onion root meristems with the pesticide Sevin [carbaryl (1-naphthyl n-methyl carbamate)] induces an accumulation of interphase nuclei with a larger diameter, and a subsequent decrease in the index of smaller nuclei. It is concluded that Sevin depresses mitosis by arresting cells at G₂ without affecting DNA synthesis.The authors are grateful to Prof. K. S. Bilgrami, Head of the Postgraduate Department of Botany, Bhagalpur University, for providing facilities and to Prof. B.N. Mookerjee for his valued suggestions.     

Alterations in lipid metabolism following trauma in rabbits

Zusammenfassung Nach Knochenverletzung beim Kaninchen kommt es im Blut zu einer drastischen Erhöhung der gesamten Lipide, freien Fettsäuren und des Cholesterols, während die Veränderungen des Serum-Phospholipids nur geringfügig ist. Die Erhöhung bleibt bis zum 9. Tag nach erfolgtem Knochenbruch.

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Acknowledgments. We are thankful to Dr.L. M. Singh, Officer Incharge, Surgical Research Laboratory, Institute of Medical Sciences for providing all the facilities.     

Thermal acclimatory responses of salivary amylase of Periplaneta americana (Linn.)

Summary A differential thermal acclimatory response of salivary amylase is evident in P. americana-nymphs demonstrating a translational and males a rotational pattern, while females exhibit the translational cum rotational pattern (Prosser's type IV-D).     

The relation between ionic fluxes and the action of drugs on smooth muscle

Zusammenfassung Verschiedene Arzneimittel inklusive Polypeptide verursachen eine Schrumpfung des in Sucroselösung getränkten Froschmagenmuskels. Dieser Schrumpfung wird durch Calcium entgegengewirkt.     

The effect of diet on the hemolymph amino acid constituents of the larvae and pupae ofSarcophaga ruficornis (Fabricius): (Diptera)

Zusammenfassung Es werden zwei Zuchtgruppen vonSarcophaga ruficornis-Larven hinsichtlich ihres Aminosäuregchaltes des Blutes untersucht. Den auf Fleisch gezüchteten Tieren fehlt Lysin, Glutamin und Taurin, während diese Aminosäuren bei den auf Hundebisquit aufgezogen Larven vorhanden sind, ihnen dagegen Threonin fehlt. Der Aminosäuregehalt im Blut der Puppen beider Zuchtgruppen ist gleich.     

Global distribution of peroxyacetyl nitrate

Nitrogen oxides (NOx) have a central role in the chemistry of the atmosphere, especially in key processes relating to ozone, hydroxyl-radical (OH) and acid formation. High reactivity of NOx (lifetime of 0.5-2 days) precludes hemispheric-scale transport and it has been proposed that non-methane hydrocarbons present in the troposphere can transform NOx into its organic forms principally as peroxyacetyl nitrate (PAN). PAN is highly stable in the colder regions of the middle and upper troposphere and can provide a mechanism for NOx storage and transport. Once transported, PAN and its homologues can easily release free NOx in warmer atmospheric conditions. PAN is probably ubiquitous and its concentrations could exceed those of NOx in clean tropospheric conditions. Here we present the first view of the global distribution of PAN based on extensive shipboard and aircraft measurements. PAN is more abundant in the Northern than in the Southern Hemisphere and in the continental than in the marine troposphere. In contrast to its behaviour in polluted atmospheres, PAN mixing ratios in winter greatly exceed those in summer. These measurements provide a basis for assessing the significance of PAN as a reservoir of NOx and for extending and validating reactive nitrogen chemistry theory in the troposphere.     

In vivo effects of epinephrine in a freshwater fish

Summary In vivo effects of epinephrine were investigated in a freshwater teleost,Barbus conchonius Hamilton. Fish given 2 mg/kg epinephrine in a single i.m. dose showed significant hypocholesterolemia and elevated, liver and kidney cholesterol levels 1–8 h postinjection. Plasma amino nitrogen evinced a transient yet significant fall at 2 h followed by a significant increase after 24 h. A marked reduction occurred in the plasma FFA and organic PO₄ levels after 1–8 h. The results offer little evidence for a lipolytic effect of epinephrine in this species, and the changes in metabolite levels are attributable, in part, to the catecholamineinduced modification of insulin secretion.N.K. thanks the U.G.C. for the award of a research fellowship.     

Natural hybridization inDrosophila

Summary Although at least 159 cases of interspecific hybridization between closely related species ofDrosophila have been obtained under laboratory conditions, only 7 cases of natural interspecific hybridization have been recorded. We report yet another case, concerningD. malerkotliana andD. bipectinata.Thanks are due to the University Grants Commission for supporting the research project of J.P.G. and to the Head of the Department for laboratory facilities.