A new species of Thysanote Krøyer, 1863 (Copepoda,Lernaeopodidae) from the Persian Gulf,with comments on the genus

Summary Thysanote alternans n. sp., a lernaeopodid copepod parasitic on Polynemus sextarius is described and illustrated. A key to 19 species of Thysanote is provided (two unnamed species included). Specific diagnosis within the genus is based on the number and shape of maxillary and posterior trunk processes. The limitations of their value as discriminant characteristics are discussed. Host affiliations of the members of the genus are examined. Distribution of Thysanote is shown to have two centres, one in the Indian Ocean and another, a smaller one, in the Caribbean. The connections between them are tenuous. ac]19810127     

Microcalorimetric study of Escherichia coli aerobic growth: theoretical aspects of growth on succinic acid.

Two methods of investigation were used to evaluate the heat quantity associated with anabolic processes (qan) during the aerobic growth of Escherichia coli in a minimal medium containing succinic acid as the sole energy and carbon source. The study of the contribution of biosynthetic reactions from succinic acid and ammonia were investigated by both methods. The two qan values obtained were in excellent agreement and were found to be significant. Thus it was demonstrated that the contribution of anabolism strongly influenced the quantity of heat associated with microbial aerobic growth. The qan calculated as above explained the experimental enthalpy change which was recently reported.     

Characterization of a cytoplasmic auxin receptor from tobacco-pith callus

Cultured tobacco-pith tissue contains a cytoplasmic receptor for indoleacetic acid (IAA). The concentration of binding sites is very low in comparison to that of several auxin receptors found by other investigators. A few obvious possible causes (degradation or inactivation) were investigated. From the results we conclude that the low number of binding sites is real. The receptor binds IAA optimally at pH 7.5–7.8 and at a temperature of 24–30°C, when incubated for 25–30 min. The binding is very specific, as is shown by competition experiments. The concentration of the receptor in the callus tissue changes dramatically during each culture period, which suggests a possible role in development. The receptor was partly purified by gel filtration on Sepharose 6B followed by ion-exchange chromatography on DEAE-cellulose.     

Senescent human diploid cells (WI-38) : Attempted induction of proliferation by infection with SV40 and by fusion with irradiated continuous cell lines

When proliferating WI-38 cells (phase II and early phase III) were infected with the Simian papovavirus SV40, or fused with lethally irradiated cells of the continuous line VA13 (containing the SV40 genome), they underwent morphological changes, showed accelerated proliferation and subsequently ceased proliferation (crisis). Senescent WI-38 cells maintained for weeks after the termination of proliferation (late phase III), however, showed neither accelerated proliferation, nor morphological changes by infection or by fusion. Proliferating WI-38 cells fused with lethally irradiated cells of several continuous cell lines, such as HeLa, did not produce continuously proliferating cell lineages. Genes responsible for the morphological changes do not appear to be responsible for the property of continuous proliferation. The crisis of morphologically changed cells appears to be equivalent to the senescent state (late phase III) of normal human diploid cells.     

Some blood genetic markers of selected tribes in Western Saudi Arabia

A total of 292 randomly selected subjects belonging to two indigenous Arab tribes (Harbi and Ghamid) and two immigrant tribes (Mograbi and Mowallad), residents in Western Saudi Arabia, have been tested for genetic variants of six blood groups, four serum proteins, and five red cell enzyme systems. The distribution of the polymorphic systems was different between indigenous and immigrant tribes, and the present Arab population shows a considerable degree of admixture from the surrounding countries, in particular Africa.     

Microbial oxidation of elemental sulphur in brown soil

Plant and Soil - Brown soil formed from loamy clay was examined for its ability to produce sulphate from added elemental suphur. At higher rates of sulphur applications the pH of a slightly acid...     

Immunofluorescent Cell Assay of Infectious Pancreatic Necrosis Virus

An immunofluorescent cell (IFC) assay technique was developed for the quantification of infectious pancreatic necrosis (IPN) virus of salmonid fishes. Cover slip cultures of rainbow trout gonad (RTG-2) cells were infected with diluted virus preparations. After incubation to permit antigen development, the cells were stained with antiviral fluorescent antibody, and the number of fluorescing (infected) cells was counted. Optimal conditions for the IFC assay procedure are: (i) the use of RTG-2 cells cultured for at least 3 days at 20 C; (ii) 1-h absorption of IPN virus to RTG-2 cells at 20 C or alternatively, 4 h at 4 C; (iii) staining the infected cell cultures at 10 to 12 h postinfection. A linear relationship between the relative concentration of virus in the inoculum and the number of fluorescent cells in the first cycle of infection was observed. The IFC assay method is more sensitive than the plaque method for the assay of IPN virus.     

Changes in UDPG: Sterol glucosyltransferase activity in Calendula officinalis

UDPG: sterol glucosyltransferase and acyltransferase which catalyse acylation of steryl glucosides are active in leaves, roots and flowers during the whole vegetative period of Calendula officinalis. The high activity of glucosyltransferase in young, developing tissues and its subsequent rapid decrease in activity in mature organs suggests that steryl glucosides are involved in the formation of some cell structures rather than in sterol transport as such within the plant.