New technique for movement analysis: Application to biological systems

Summary A new system for motion analysis is described. Modulation of light intensity by an organism's movement over an opaque and transparent checkerboard grid is monitored by a photocell. The photocell's output is proportional to the organism's amplitude and frequency of movement. This output is analyzed by a continuous interval dot display and spectral analysis. The system was tested by analyzing the activity of 4 Drosophila strains which are known to differ in their activity. General applicability of the system is discussed.This research was supported by a grant from the United States-Israel Binational. Science Foundation (BSF), Jerusalem, Israel.     

New technique for movement analysis: application to biological systems

A new system for motion analysis is described. Modulation of light intensity of an organism's movement over an opaque and transparent checkerboard grid is monitored by a photocell. The photocell's output is proportional to the organism's amplitude and frequency of movement. This output is analyzed by a continuous interval dot display and spectrum analysis. The system was tested by analyzing the activity of 4 Drosophila strains which are known to differ in their activity. General applicability of the system is discussed.     

Permeability of Ehrlich ascites cells and spectrophotometric assay of the sub-cellular enzymes

Summary A permeabilization method which allows the assay of intracellular enzymes of the Ehrlich ascites cells is described. The developmental changes in the activity of lactic dehydrogenase and glucose-6-phosphate dehydrogenase of toluene-treated Ehrlich ascites cells were studied.Acknowledgment. M.D. is grateful to CSIR for the award of Junior fellowship.     

The agar gel-diffusion technique as a method of differentiating mosquito larvae

Zusammenfassung Mit der Gel-Diffusionstechnik lassen sich die Larven vonCulex pipiens fatigans, Aedes aegypti und Armigeres subalbatus unterscheiden. Wegen teilweise gemeinsamen Antigenen vonArmigeres subalbatus undAedes aegypti ist eine Differenzierung dieser verschiedenen Species bei Verwendung von Larven weniger eindeutig als bei Verwendung von Eiern.      

The agar gel-diffusion technique as a method of differentiating mosquito eggs

Zusammenfassung Bei Agargel-Diffusionstechnik zeigenCulex-pipiens-fatigans-Eier mindestens vier deutlich voneinander unterscheidbare Präzipitationslinien, wenn sie mit homologem Antiserum reagierten. Eier vonArmigeres subalbatus, Aedes aegypti undAedes albopictus hingegen zeigten nur eine einzige Linie bei Reaktion mit dem gleichenCulex-Antiserum.     

An investigation of na efflux from the toad oocyte using cold shock as a technique

Zusammenfassung Die infolge der verzögerten Wirkung von Ethacrynsäure nur näherungsweise erfassbare Hemmung der Abgabe von Na⁺ durch Oozyten der Kröte (Bufo bufo) lässt sich exakter bestimmen, wenn die chemische mit einer Temperaturbehandlung kombiniert wird.     

Demonstration of a net movement of water through the lens

Résumé Des cristallins de lapins couvés dans des diméthylsilicones sécrètent un fluide à leur surface antérieure. Ce fluide peut prendre le même aspect et la même réticulation qu'un morceau du tissu de la surface postérieure, si le cristallin est excisé promptement après la mort.

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This work was supported in part by a grant from the Institute of Neurological Diseases and Blindness N.I.H., No. NBO1979. The technical assistance ofR. Lukanen and CarolynMcDonald with picture taking and lens preparation respectively is gratefully acknowledged. The author gives a special thanks to Prof.J. E. Harris for helpful discussions and encouragement wihch led to this work.     

A cell-marking technique for a cellular slime-mold

Summary A simple technique for marking cells of the cellular slime moldDictyostelium discoideum has been developed, using the phagocytic action of the cells. TheD. discoideum are fed onE. coli stained with neutral red and clearly red colored amoebae are obtained.     

Flow microcalorimetry as a tool for an improved analysis of antibiotic activity: the different stages of chloramphenicol action

Flow microcalorimetry in combination with photometric mass determination of staphylococci in suspension was used to reveal alterations in the intensity, extent and efficiency of bacterial metabolism during inhibition of protein synthesis by chloramphenicol. It could be demonstrated that these three parameters of metabolic activity were distinctly affected by this drug, and that the method described promises to be a more reliable tool for assaying the degree and the mode of bacteriostatic inhibition than the conventional determination of the minimum inhibitory concentration.     

The agar gel-diffusion technique as a method of tracing mosquito antigens in the water bugAnisops breddini (Notonectidae)

Zusammenfassung Mit der Agar-Gel-Diffusionsmethode konnte das Mückenantigen in der sich von Mückenlarven ernährenden WasserwanzeAnisops breddini (Notonectidae) bis zu 6 h nach der Nahrungsaufnahme nachgewiesen werden.     

Peristaltic movement of the tortoise intestine

Zusammenfassung Am Schildkrötendarm kann die peristaltische Bewegung weder durch Erhöhung des Binnendruckes, noch durch Kombination interner Applikation von 5-Hydroxytryptamin oder Acetylcholin mit Druck angeregt werden. Druckwirkung auf die Mucosa und Einwirkung von 5-Hydroxytryptamin oder Acetylcholin auf die Serosa war jeweils erfolgreich. Präparate von Längsmuskelstreifen reagierten nicht auf 5-Hydroxytryptamin, während die Ringmuskelstreifen mit Kontraktur antworteten.     

Adjuvant activity of ricin as measured by Jerne's plaque technique

Zusammenfassung Es wird gezeigt, dass Injektion von Rizinus-Extrakt die Plaque-Bildung im Jerne-Test fördert, was dafür spricht, dass die zytostatische Wirkung des Rizinus mit der Adjuvansfähigkeit gekoppelt ist.

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We are greatly indebted to Drs. M.Funatsu and G.Funatsu for their supply for ricin and to Miss Y.Nagakawa for her excellent technical assistance.