A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the Degree of Doctor of Philosophy. / The comparative structure of the diencephalon was investigated in the elephant shrew, the tree-shrew and several of the prosimian and anthropoid primates, including man. The brains were perfused with and fixed in formol saline. Most of those brains were sectioned transversely; others horizontally and sagitaliy. Sections of the diencophalon were stained with the cresyl-echt violet method for cytology and the study of cytoarchitectonics, and with the Kluver and Barrera, and Simmons techniques for myeloarchitectonics. / WHSLYP2017

No description available.

No description available.

Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, August 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 74-84. Includes bibliographical references (leaves 85-92).

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 74-84. Includes bibliographical references (leaves 85-92).

The following study was conducted from August to November of 1991 on North Pagai Island in the Mentawai Archipelago, Indonesia. The purpose of the study was to obtain preliminary information on the ecology and behavior of the four Mentawai endemic primates: Hylobatcs klossii, Macaca pagensis, Presbytis potenziani, and Simias concolor. All four species are considered endangered due to human activities, especially hunting and various forms of habitat destruction. Therefore, the present critical status of these primates makes their conservation and that of the Mentawai Islands' rain forest a priority. It appears that resource partitioning occurs among the four primate species, M. pagensis occupied all vegetation levels and was less arboreal relative to the other three species which were primarily arboreal. All four species were found in forest habitat with S. concolor also occurring in forest swamp. M. pagensis and P. potenziani were found throughout the study area and only P. potenziani occupied coastal swamp. In addition, it is hypothesized here that for many P. potenziani groups, sleeping trees are located outside of the primary forest and these groups migrate on a daily basis to the forest. As a result, this may reduce interspecific competition since this species and H. klossii overlap in terms of resource use. Group size and composition are discussed and a monogamous social organization was identified for H. klossii and P. potenziani while M. pagensis. was found to form polygamous families. S. concolor is identified as forming one-male polygamous groups, however, based on my observations it might initially be interpreted that this species formed monogamous groups in the study area. Most behaviors, such as parental care, aggression, grooming, play, and feeding behavior, were rarely observed due to the wanness of these primates. Alarm response to detection of humans is discussed and distraction-like behaviors are described for each of the species. Population density was determined for each species and these values corresponded to those found in other studies although all values in this study were relatively low compared to other studies.

The Best PhD Thesis in the Faculties of Dentistry, Engineering, Medicine and Science (University of Hong Kong), Li Ka Shing Prize,1999-2001 / published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

We investigated the spatio-temporal frequency selectivity properties of 248 neurons in VI and VII of the macaque monkey, and the receptive field properties of 43 inferotemporal neurons of the owl monkey. The study of VI and VII neurons was carried out using sine wave gratings. Our results show that VI and VII neurons were selective to different but partially overlapping spatial frequency ranges (at retinal eccentricities of 2°-5°, VII neurons are tuned approximately two octaves lower than VI neurons). The spatial frequency bandwidths for the two visual areas are similar. The temporal frequency selectivity of VI neurons was mostly lowpass (70%), or wide bandpass (30%, mean bandwidth 3 octaves); 62% of VII neurons had bandpass temporal frequency tuning curves (mean bandwidth 2 octaves). The range of preferred temporal frequencies and the bandwidths of VII neurons suggest the existence of at least two non-overlapping temporal frequency filters at each spatial frequency. Results also indicate that spatial and temporal selectivities are independent fundamental properties. Our results may provide physiological support for psychophysical findings in man, suggesting several independent detection mechanisms centered at different temporal frequencies, especially at low spatial frequencies. In a different study, a possible substructure of the large inferotemporal receptive fields was investigated in the owl monkey. A novel kind of stimulus derived from the Gabor elementary functions was used as test signal. A first set of stimuli with a constant relative spatial frequency bandwidth was used to probe the existence of either one or more than one spatial frequency band within one receptive field. A second set of constant spatial width was used to test the neruon's spatial frequency selectivity. Results suggest that only one orientation and spatial frequency band project onto each neuron. The preferred spatial frequencies (0.2 - 0.6 c/deg) were in the very low spatial frequency range for this animal. The spatial frequency bandwidth comparable to that of striate cells, the inclusion of many cycles of the preferred spatial frequency within the receptive field, and the generally reduced response to constant aperture test signals, suggest non-linear processing during summation of information from preceding visual areas.

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