Enteric Protozoa of Some Amphibians of the Elk Mountains, Colorado

Author Institution: Department of Velerinary Medicine, Oregon State University, Corvallis, Orego

Histochemical study of some enzymes of the common liver fluke, Fasciola hepatica L.

Acid and alkaline phosphatase was localized histochemically in the intestinal epithelium and excretory duct respectively in fresh frozen sections of Fasciola hepatica. Polyphenol oxidase was localized in the vitellaria, vitelline ducts and egg-shells. The distribution and nature of esterases was examined histochemically. Acetyl-cholinesterase was observed in the tegument, neural ganglia, neural commisure, acetabulum and oral sucker. Pseudocholinesterase was observed in the pharynx, cirrus, cirrus pouch wall, prostate gland sperm sac, testes, ovary, vitelline duct and duct walls of Mehlis' gland. Use of differential inhibitors of mammalian cholinesterases indicated that presence of acetylcholinesterase in structures containing pseudocholinesterase could not be demonstrated by differential enzyme activity. Non-specific esterase is reported in the excretory ducts and intestinal epithelium. The possible functions of the various esterases is discussed. Succinic dehydrogenase was observed in all those organs and tissues reported to contain esterases. It is reported from the cirrus, cirrus pouch wall, prostate gland and sperm sac for the first time. The effects of various concentrations of Ruelene (4-tert-butyl-2-chlorophenyl methyl methyl phosphoramidate), Halaxon (di(2-chloroethyl) 3-chloro-4 methylcoumarin-7-yl) phosphate, CoRal (0, 0-diethyl-0-3-chloro-4-methyl-2-oxo-2H-l-benzyopyran-7-yl phosphorothioate), Dibenzylamine (DABA, 1, 6 bis (methylamino-methylphenoxy) hexane dihydrochloride), Tris (p-aminophenyl) carbonium chloride (TAC, pararosaniline chloride), Bayer 9015 (B9015, 3, 3'-dichloro-5, 5'-dinitro-0, 0'-biphenol), Bithionol (2, 2'-thiobis (4, 6-dichlorophenol) 'Actamer') were examined for inhibitory effect against fluke cholinesterases. Bithionol and B9015 failed to inhibit esterases activity. CoRal, Neguvon, TAC and Halaxon inhibited all cholinesterase activity. Ruelene reversibly inhibited pharyngeal and reproductive complex cholinesterases but non-reversibly inhibited tegumental and neural Acetylcholinesterase. Dibenzylamine reversibly inhibited all cholinesterases. Bayer 9015 and DABA failed to inhibit excretory duct alkaline phosphatase activity. Bayer 9015 failed to inhibit acid phosphatase activity in intestinal epithelium. Bithionol, Bayer 9015 and Hexachlorophene (2, 2' dihydroxy-3, 5, 6-3'5'6' hexachlorodiphenyl methane) all inhibited succinic dehydrogenase at all concentrations tested. Dibenzylamine had no inhibitory effect while TAC partially inhibited the staining reaction. Incubation of adult flukes in DABA-Hedon-Fleig saline for 8, 18 or 24 hours resulted in a decrease in PAS positive material and loss of tegument. This is compared with Bayer 9015 induced necrosis and a hypothesis explaining the mechanism of this necrosis is presented

INCIDENCE OF COCCIDIA (EIMERIDAE) IN ADULT EWES AND LAMBS ON ST. CROIX

INCIDENCE OF COCCIDIA (EIMERIDAE) IN ADULT EWES AND LAMBS ON ST. CROI

Analyses of pig genomes provide insight into porcine demography and evolution

For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars ∼1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model

Restructuring the University - An Experiential Exercise

The author presents and comments on an experiential exercise addressing organizational structure and goal attainment

Tinte: developing a prototype for typesetting music in Clean : a case study

This paper describes the development of a typesetting program for music in the lazy functional programming language Clean. The system transforms a description of the music to be typeset in a dvi-file just like TEX does with mathematical formulae. The implementation makes heavy use of higher order functions. It has been implemented in just a few weeks and is able to typeset quite impressive examples. The system is easy to maintain and can be extended to typeset arbitrary complicated musical constructs. The paper can be considered as a status report of the implementation as well as a reference manual for the resulting system

Termination proofs for a lazy functional language by abstract reduction : (draft)

Automatic termination proofs of functional programming languages are an often challenged problem Most work in this area is done on strict languages Orderings for arguments of recursive calls are generated In lazily evaluated languages arguments for functions are not necessarily evaluated to a normal form It is not a trivial task to de ne orderings on expressions that are not in normal form or that do not even have a normal form We propose a method based on an abstract reduction process that reduces up to the point when su cient ordering relations can be found The proposed method is able to nd termination proofs for lazily evaluated programs that involve non terminating subexpressions Analysis is performed on a higher order polymorphic typed language and termi nation of higher order functions can be proved too The calculus can be used to derive information on a wide range on di erent notions of termination