Book reviews

Manipulation of the Avian Genome. Edited by R. J. Etches & A. M. V. Gibbins, 1993. 322 pp., illustrated in colour. Boca Raton, FL, CRG Press. ISBN 0–8493–4216–3.

Proceedings of the 8th European Symposium on Poultry Nutrition. Edited by The Organizing Committee, 1992. 373 pp. Milan, Italy. World's Poultry Science Association.     

Variation in plasma cholesterol concentration over time in the domestic fowl

1. Variations in the concentration of plasma cholesterol available to the developing oocyte over a three week period in Gallus domesticus are described.

2. There are small changes in concentration between weeks for individual birds, but no changes between consecutive days within weeks or times within days.

3. It is recommended that future attempts to assess the relationship between variation in blood and yolk cholesterol concentrations estimate blood cholesterol concentration from two samples taken a week apart.     

Effects of faba bean tannins on the growth and histological structure of the intestinal tract and liver of chicks and rats

1. Diets containing a freeze‐dried tannin extract from faba beans (Vicia faba L.) at concentrations of 0, 8 and 16 g/kg were fed to growing chicks and rats.

2. Chicks fed on the tannin‐containing diets exhibited a high mortality and significant decreases in body‐weight as well as lower food intakes and higher food intake:weight gain ratios (P<0.01). In rats there was no mortality but the growth and food intake were adversely affected (P< 0.05).

3. Histological changes occurred in the ileal mucosa of chicks. Atrophy and shortening of villi with distortion of their architecture were observed. Similar histological disorders but less pronounced were also found in rats.

4. Histopathology of the liver of both chicks and rats showed an hydropic degeneration of hepatocytes, clearly more severe in the former than in the latter.     

Conducting carbon wires in ordered, nanometer-sized channels

The encapsulation of graphite-type carbon wires in the regular, 3-nanometer-wide hexagonal channels of the mesoporous host MCM-41 is reported. Acrylonitrile monomers are introduced through vapor or solution transfer and polymerized in the channels with external radical initiators. Pyrolysis of the intrachannel polyacrylonitrile results in filaments whose microwave conductivity is about 10 times that of bulk carbonized polyacrylonitrile. The MCM host plays a key role in ordering the carbon structure, most likely through the parallel alignment of the precursor polymer chains in the channels. The fabrication of stable carbon filaments in ordered, nanometer-sized channels represents an important step toward the development of nanometer electronics.