Prolactin and colibacillus-induced fluid transport in ligated intestinal segments.

Two experiments, using the ligated intestinal segment technique, were conducted to determine whether the pituitary hormone prolactin (PRL) could reduce Escherichia coli-induced fluid loss into the small intestine of 2- to 3-week-old pigs. Inoculation of 10(6) to 10(8) enteropathogenic E coli organisms into ligated jejunal segments caused a significant accumulation of luminal fluid within 12 hours. In the first experiment, intraluminal inoculation with 0.5 mg of ovine PRL along with the bacteria did not have any effect on fluid accumulation. Systemic IV treatment of the animals with 1.0 mg of ovine PRL at 3-hour intervals, beginning either immediately after or 9 to 10 hours before intestinal ligation, did not significantly (P less than 0.05) reduce fluid accumulation as compared with control animals. In the second experiment, IM administration of 100 microgram of thyrotropin-releasing hormone (TRH) at 3-hour intervals, beginning 6 hours before intestinal ligation, significantly (P less than 0.05) increased circulating PRL concentrations, as measured by radioimmunoassay. However, TRH treatment did not reduce the accumulation of luminal fluid in E coli-inoculated segments.     

The influence of temperature on the development of Moniezia expansa (Rudolphi, 1810) in oribatid mites

The life cycle of Moniezia expansa was studied experimentally using 10 species of oribatid mites as intermediate hosts. Four of them became infected, namely Scheloribates laevigatus (76.2%), Sch. latipes (70.8%), Liacarus coracinus (20%) and Platynothrus peltifer (1.1%). The last was found for the first time to serve as intermediate host of M. expansa in Czechoslovakia. The development of the cysticercoid of M. expansa in the oribatid mites at 28 degrees C and 85% relative humidity is completed within 27 days. At 18-20 degrees C and the same relative humidity the development lasts even 97 days.     

Scanning electron microscopic studies on males of trichinella species

Ultrastructure of the cuticle and pseudobursa of adult males of four species of Trichinella has been studied by SEM. T. nativa differs markedly from T. spiralis, T. nelsoni and Trichinella sp. in the form of the pseudobursa. Trichinella sp. differs only slightly from T. spiralis and T. nelsoni. The ultrastructure of the cuticle revealed no characters suitable for the differentiation of the taxons under study.     

Changing role of public and private sectors in agricultural research

The considerations involved in defining appropriate roles for the public and private sectors in agricultural research are examined with respect to mechanization, plant variety, and insecticide research and development. It is concluded that the public sector should continue to give mechanization a low priority. Varietal improvement should remain a relatively high priority until the effects of plant variety protection legislation become more apparent. Simultaneous achievement of safety, environmental, and productivity objectives in insect pest control will require that the public sector play a larger role in research and development.     

Use of the space shuttle for remote sensing research: recent results and future prospects

Routine access to low earth orbit provided by the space shuttle holds great potential for global studies of the earth's resources and its environment. A successful test flight of the Columbia orbiter in November 1981 demonstrated the utility and versatility of the shuttle for earth-related research. A series of remote sensing experiments is currently planned for the mid-1980's that will more fully exploit the shuttle's earth observation capabilities.