A modular detector for flow cytometric multicolor fluorescence measurements

A modular detector for measuring multicolor fluorescence from cells illuminated by single or multiple lasers has been developed for flow cytometers. Motion picture projector, camera, and CCTV/video lenses were evaluated for use in the detector by comparing their physical characteristics, image quality, and light collection efficiencies. A 25-mm focal length F/0.95 CCTV lens was selected, based on our criteria and test results. The detector was constructed out of square aluminum extrusion channels. A CCTV lens mounted on the outside of the first channel collected light emitted from cells and collimated it towards filters and secondary CCTV lenses located in each channel. The secondary lenses functioned as relay optics for directing and focusing light onto pinhole spatial filters for measurement by photomultipliers. The detector design allowed any number of channels to be connected together and the versatility for making simultaneous or sequential measurements. Measurements on lymphocytes labeled with four monoclonal antibodies conjugated to fluorescent dyes and measurements on viable tumor cells stained for DNA content and with three fluorescent-labeled antibodies were used to demonstrate the detector's capabilities.     

Chlorierte Kohlenwasserstoffe in Brutv?geln aus dem Binnenland Niedersachsens

Zusammenfassung Rückstände chlorierter Kohlenwasserstoffe in Eiern und Lebern von im Binnenland Niedersachsens brütenden Vogelarten — Feldsperling, Mehlschwalbe, Weißstorch, Graureiher, Saatkrähe, Stockente und andere Arten — werden angegeben und deren Abhängigkeit von Brutort, Nahrung und Zugverhalten diskutiert.

---

Chlorinated hydrocarbons of some bird species breeding in the inland of Lower Saxony (FRG)

Summary Residues of chlorinated hydrocarbons in eggs and livers of some bird species — Tree Sparrow, House Martin, White Stork, Heron, Rook, Mallard, and further species — are presented. The dependence on place of breeding, food web, and migration is discussed.

     

Changes in the auditory system of locusts (Locusta migratoria and Schistocerca gregaria) after deafferentation

Deafferentation experiments during postembryonic development show morphological and/or physiological changes of receptor fibers and of identified auditory interneurons in the CNS of the locusts Locusta migratoria and Schistocerca gregaria after unilateral ablation of one tympanic organ either in the larva or the adult animal.

Growth characteristics and ion contents of non-selected and salt-selected callus lines of highbush blueberry (Vacdnium corymbosum) cultivars Blue Crop and Denise Blue

Non-selected and sodium chloride selected callus lines of Vacdnium corymbosum L.cv Blue Crop and cv. Denise Blue were grown on media supplemented with 0–100 mM NaCl. For both cultivars, fresh weight and dry weight yields were greater in selected lines on all levels of NaCl. Selected lines of Blue Crop displayed better growth than selected lines of Denise Blue at most concentrations of NaCl. Internal Na⁺ and Cl^– concentrations in selected and non-selected lines of both cultivars increased as external concentration was raised. However, selected lines of Blue Crop and Denise Blue accumulated more Na⁺ and Cl^– than non-selected lines. Selected lines of both cultivars maintained higher levels of K⁺ than non-selected lines on all external NaCl levels. Selected lines of Blue Crop had higher levels of Na⁺ and Cl^– than that of Denise Blue. The results suggest Na⁺ and Cl^– accumulation could be a mechanism allowing better growth in selected lines at moderate salinity levels (50–75 mM NaCl).     

Different numbers of maternal and paternal siblings of cystic fibrosis patients

Summary When 458 parents of children suffering from cystic fibrosis (CF) from all over the German Democratic Republic were interviewed to determine the number of their siblings, it was found that the maternal families had a total of 1369 children and the paternal, 1220. While the fathers of CF patients tended to originate from families with one or two children, more mothers than fathers came from families with three to twelve children (P=0.01). The average number of children in the maternal families was 2.99; in the paternal families, only 2.66. To rule out any methodological errors, sibs of mothers and fathers of various control groups were studied. We found that the number of siblings in these groups was balanced. The differences in our findings are probably due to CF heterozygosity. The underlying mechanism is unknown.     

Nonlinear analysis of some models for the evolution of dominance

For two different classes of models for the evolution of dominance modifiers a nonlinear analysis is performed. The first class arises from the classical model of R. A. Fisher by assuming that the modifiers under consideration are not neutral in their pleiotropic effects. The second class is based on a model of P. M. Sheppard for the evolution of dominance in mimicry. Again the derived models with non-neutral modifiers are analysed.     

Interactions between Plants and Epiphytic Bacteria Regarding Their Auxin Metabolism VI. The Influence of the Epiphytic Bacteria on the Content of Extractable Auxin in the Plant

Sterile plants of maize, pea, and cucumber contain less auxin (extracted with methanol or ether) than nonsterile ones. The auxin content is restored within one day by reinfecting sterile plants (or only the shoots, with roots and culture medium remaining sterile) with epiphytic bacteria strains able to produce IAA or with soaking water of nonsterile seeds. Reinfection with bacteria, strains unable to produce IAA is ineffective. — The possibility of a bacterial auxin production during methanol extraction was excluded.     

Unterschiedliche Wirkung von Captan auf das Wachstum einiger Stämme von Chlorella und Scenedesmus

Zusammenfassung Das Fungicid Captan erwies sich bei 37 Stämmen von Chlorella als ein wirksamer Wachstumshemmstoff. Nur 3 Chlorella-Stämme besitzen eine gewisse Captanresistenz. Das Merkmal Captanresistenz scheint in der Gattung Chlorella nicht artspezifisch verteilt zu sein.Bei Scenedesmus acutus f. alternans Hortob. und Scenedesmus armatus (Chod.) Smith wird Captan noch in einer Dosis von 50 mg/l vertragen, ohne daß Anzeichen einer Hemmwirkung zu erkennen sind.

---

Differential action of captan on the growth of some strains of Chlorella and Scenedesmus

Summary The fungicide captan was found to inhibit strongly the photoautotrophic growth of 37 Chlorella strains. Only 3 strains are fairly resistant to captan. In the genus Chlorella resistance to captan does not seem to be species specific.Two strains of Scenedesmus (Scenedesmus acutus f. alternans Hortob. and Scenedesmus armatus (Chod.) Smith) tolerate captan up to 50 mg/l without being inhibited at all.