40 research outputs found
Submicron Structures Fabrication and Research
Contains reports on twelve research projects.Lawrence Livermore Laboratory (Subcontract 2069209)Joint Services Electronics Program (Contract DAAG29-C-0104)U.S. Navy - Office of Naval Research (Contract N00014-79-C-0908)Joint Services Electronics Program (Contract DAAG29-80-C-0104)Harkness FoundationI.B.M.U.S. Department of Energy (Contract DE-ACO2-80-E10179)National Science Foundation (Grant ECS80-17705
Nodular Worm Infection in Wild Chimpanzees in Western Uganda: A Risk for Human Health?
This study focused on Oeosophagostomum sp., and more especially on O. bifurcum, as a parasite that can be lethal to humans and is widespread among humans and monkeys in endemic regions, but has not yet been documented in apes. Its epidemiology and the role played by non-human primates in its transmission are still poorly understood. O. stephanostomum was the only species diagnosed so far in chimpanzees. Until recently, O. bifurcum was assumed to have a high zoonotic potential, but recent findings tend to demonstrate that O. bifurcum of non-human primates and humans might be genetically distinct. As the closest relative to human beings, and a species living in spatial proximity to humans in the field site studied, Pan troglodytes is thus an interesting host to investigate. Recently, a role for chimpanzees in the emergence of HIV and malaria in humans has been documented. In the framework of our long-term health monitoring of wild chimpanzees from Kibale National Park in Western Uganda, we analysed 311 samples of faeces. Coproscopy revealed that high-ranking males are more infected than other individuals. These chimpanzees are also the more frequent crop-raiders. Results from PCR assays conducted on larvae and dried faeces also revealed that O. stephanostomum as well as O. bifurcum are infecting chimpanzees, both species co-existing in the same individuals. Because contacts between humans and great apes are increasing with ecotourism and forest fragmentation in areas of high population density, this paper emphasizes that the presence of potential zoonotic parasites should be viewed as a major concern for public health. Investigations of the parasite status of people living around the park or working inside as well as sympatric non-human primates should be planned, and further research might reveal this as a promising aspect of efforts to reinforce measures against crop-raiding
Halogen complexes of heterocyclic amines
Includes bibliographical references.Interest in spectrophotometric study of complexes of aromatic hydrocarbons and halogens started with the studies of Benesi and Hildebrand (l). Their investigation of several different aromatic hydrocarbon-iodine solutions in carbon tetrachloride and hexane showed that, in addition to the known iodine maximum near 500 mn, another maximum existed at about 297 mn. They found convincing evidence that the ultraviolet maximum is a charge-transfer peak, due to a 1:1 complex between the iodine and the aromatic hydrocarbon, and were able to calculate the formation constant of the complex from spectrophotometric data. The addition of methyl groups to benzene increased the stability of the halogen complex; for example, the mesitylene-iodine complex was more stable than the benzene-iodine complex. This observation has been explained by the fact that methyl groups are electron repelling and thus increase the availability of the TT-electrons for complex formation. This gave strong support for the Lewis acid-base explanation of the interaction involved in this type of complex.M.S. (Master of Science
Some halogen complexes of 2,2'-bipyridine
Includes bibliographical references.Spectrophometric studies of complexes of aromatic hydrocarbons and halogens have been of interest in recent years. Lately, this interest has expanded to other halogen complexes. This paper is a report of the studies performed on some halogen complexes of 2,2'-bipyridine. Three systems were studied spectrophometrically in carbon tetrachloride. These systems were 2,2'-bipyridine, iodine monobromide and iodine monochloride. The following results were obtained in the study. 1. Iodine and 2,2'-bipyridine, in carbon tetrachloride solution, form a complex of 1:1 composition. The formation constant for this complex, using the Ketelaar method, is 5:01. 2. Iodine monobromide and 2,2'-bipyridine, in carbon tetrachloride solution, form a complex of 1:1 composition. The formation constant for this complex, using the Ketalaar method, in 10.7. 3. Iodine monochloride and 2,2'-bipyridine, in carbon tetrachloride solution, form a complex of undetermined composition. The method of continuous variation indicated a composition of 1:1 for the complex, but the determination of the formation constant was not possible.C.A.S. (Certificate of Advanced Study