The face holds a central role in both human and nonhuman primate social interactions, through the communication of feelings and intentions via facial expressions and by acting as a means of recognising individuals. Humans, however, also employ their faces in mate attraction and assessment, an area that has received little attention in nonhuman primates. Many researchers have proposed that human aesthetic judgments of facial attractiveness have a biological basis, and these preferences have evolved via sexual selection processes during human evolution. The use of the face in attractiveness assessments need not be limited to humans. Rather, there is good reason to suggest that this may also apply to other nonhuman primates, based on homologies in the way in which primates use their faces, and on evidence that the face is a site of sexual selection for many primate species. It was the aim of this thesis to explore whether facial traits may also play a role in judgements of attractiveness in a nonhuman primate, the rhesus macaque( Macaca mulatta), in an effort to understand whether humans are unique in utilising the face as a mechanism of mate assessment. Three factors that are reported to influence facial attractiveness in humans are facial symmetry, sexual dimorphism, and averageness. To assess whether they also play a role in nonhuman primates, a series of experiments were conducted where digital images of adult male and female rhesus macaque faces were altered for these features. Opposite-sexed images were then displayed to adult males and females in a captive setting. Eye gaze measures were utilised to assess visual preference for, and the relative importance of, these traits. These experiments yielded mixed results. Increasing facial symmetry of opposite-sexed conspecifics positively influenced the dependent gaze measures employed here. Manipulating degree of facial sexual dimorphism had little influence on the visual gaze of either sex. Facial averageness positively influenced visual preferences for opposite-sexed conspecifics among both sexes, although increasing degree of averageness did not. The last topic to be explored was facial colouration. Rhesus macaques like, various other species of anthropoid primates, possess facial displays of red secondary sexual colouration. As above, animals viewed digitally altered pale and red versions of opposite-sexed conspecifics. Although females displayed preferences for red male faces, males displayed no clear preferences based on female facial colour. This raises the possibility that male and female facial colour may serve different roles in intraspecific signaling. While it cannot be concluded that visual preferences are indeed indicative of real-life preferences, the results do indicate that animals are not indifferent to variations in conspecific facial features. The present findings have important implications regarding the evolution of facial attractiveness, as they provide the first experimental evidence suggesting that facial features may serve as a mechanism for mate selection across primate taxa and that both human and nonhuman primates may employ similar criteria to appraise facial attractiveness.

The lack of an animal model that recapitulates the prominent features of HIV-1 infection in humans limits the search for preventative and curative strategies against HIV-1. As stated by the National Institutes of Health (NIH), developing highly pathogenic simian-human immunodeficiency viruses (SHIVs) that can establish persistent infections and AIDS progression in rhesus macaques (RMs) remains vital for advancing the field. The HIV-1 envelope (Env) serves as a major target in vaccine studies. SHIVs - which are chimeras of the simian immunodeficiency virus (SIV) backbone and a humanized Env, are utilized for preclinical evaluation of vaccines and therapeutics aimed at targeting the Env glycoprotein. However, SHIVs presently available poorly infect RM due to weak binding interactions between Env and rhesus CD4 (rhCD4). Position 375 (Env375) lies within the rhCD4 binding pocket of HIV-1 Env. Accordingly, substituting the wild-type (WT) amino acid in Env375 for bulky hydrophobic and/or basic amino acids may strengthen Env-rhCD4 interactions. These mutations should increase the pathogenicity of our original SHIV challenge stocks (SHIV162p3 and SHIVAE16) and allow for the development of an animal model that closely mirrors HIV-1 acquisition and chronic AIDS infection in humans. OBJECTIVES: To develop an animal model that recapitulates HIV-1 infection and AIDS progression in humans. MATERIALS AND METHODS: SHIV design involved insertion of human env sequences into a modified SIV backbone (provided by Dr. George Shaw, University of Pennsylvania). Site-directed mutagenesis was employed to introduce amino acid substitutions at Env375 for the following residues: serine, histidine, methionine, tryptophan, tyrosine, and phenylalanine. These constructs were then utilized for transfection of human embryonic kidney cells (293T) with viral supernatants collected 72 hours post-transfection. 293T viral supernatants were then used to infect human and rhesus PBMCs with the resulting supernatant harvested every three days and subjected to ELISA to monitor viral growth. Viruses were further characterized by RT-PCR for quantification and TCID50 assays to determine infectious dose. Resulting SHIVs were then used for challenge studies in rhesus macaques. Sixteen rhesus macaques were divided into groups of four that received the following SHIV challenge stocks: (1) original SHIV162p3, (2) modified SHIV162p3, (3) original SHIVAE16, and (4) modified SHIVAE16. Following infection, animal plasma and sera were collected and subjected to post-challenge analyses such as cellular assays and measurements of plasma viral RNA levels. RESULTS: Several analyses were conducted to study the pathogenicity of the modified SHIV162p3 and SHIVAE16 relative to the original stocks. Regarding SHIV infectivity, several versions of the modified SHIVs exhibited greater in vitro infectivity titers than the original stocks. Additionally, preliminary viral load analyses conducted in vivo indicate that all sixteen RMs challenged with original and modified SHIVs were infected at comparable levels. Furthermore, CD4+ T cell counts were measured and all sixteen animals exhibited declines in CD4+ T cell percentages. CONCLUSION: In sum, the modified SHIVs may improve animal models by closely recapitulating the events of HIV-1 infection in humans and serve better for future studies of preventative and curative treatments against HIV-1. / 2019-07-11T00:00:00Z

Flavin-containing monooxygenase (FMO, EC1.14.13.8) comprises a family of xenobiotic-metabolizing enzymes that catalyze the oxygenation of a wide variety of xenobiotics, most commonly nitrogen and sulfur. Mammals express five different FMOs in a species- and tissue- specific manner. FMO2, is expressed predominantly in lung and differs from other FMOs in that it can catalyze the N-oxygenation of certain primary alkylamines. From its initial discovery as an unique form of FMO in lung, FMO2 has been studied primarily using a rabbit animal model. The initial goal of this research was to characterize this protein in a primate animal model. To understand FMO2 protein structure at the molecular level, we first cloned cDNA from a monkey lung cDNA library. Monkey FMO2 is expressed predominantly in lung. The high expression levels and broad substrate specificity in monkey, suggests that FMO2 plays a role in xenobiotic metabolism in this primate model. We then established a heterologous expression system to generate FMO2 with biological functionality in vitro. FMO2 from baculovirus-mediated expression resembled monkey and rabbit microsomal FMO2 immunochemically and catalytically. The successful FMO2 expression in the baculovirus system will serve as a valid tool for structure studies of protein functional domains, as well as, the amino acids responsible for enzyme properties of chimeras. Human FMO2 encodes a truncated protein containing 471 amino acid residues, 64 amino acids shorter in its C-terminal than orthologs in other species. We characterized human FMO2 in terms of gene polymorphism (genotyped by Dr. Hines), protein levels and catalytic activity with human lung microsomes. An ethnically related polymorphism was observed, in which all Caucasians genotyped to date are homozygous for a truncated, enzymatically inactive enzyme which may not even be translated. Approximately 15% of humans of African descent are heterozygous for full-length FMO2, but the level of expression may not be sufficient to significantly effect drug metabolism in the lung. The results of truncated FMO2 produced from baculovirus expression suggest that the C-terminal of FMO2 might be responsible for enzyme stability and/or proper structure necessary to exert fully enzyme activity. We conclude that the human FMO2 possesses unique features compared to all other mammals examined to date including other primates. / Graduation date: 1999

Area LIP has long been considered to be heavily involved in controlling transformations of visual stimuli into oculomotor behavior, as well as being an integral part of the extensive cortico-cortical network that controls covert visual attention. Neurons in LIP have been shown to respond to shifts in spatial attention as well as changes in the reward contingencies associated with visual stimuli, leading to the hypothesis that this area is involved in the selective processing of behaviorally relevant visual stimuli. However, the effects of attentional and motivational processes on neuronal activity in LIP have not been fully dissociated from each other. In one experiment I found that changing the reward contingencies in a peripheral visual detection task sytematically modulated visual responses in LIP, and that these changes in activity were correlated with the reaction time costs of re-orienting attention. In a further experiment, I manipulated the motivational state of rhesus macaque monkeys by varying the reward value associated with successful completion of a cued reflexive saccade task, and was thus able to study the neuronal activity in LIP while attention and motivation were independently controlled and manipulated. LIP responses to visual targets showed that directed visual attention systematically increased activity in neurons coding the attended location, suggesting spatially specific selective processing of that part of the visual field. In contrast, increasing motivation multiplicatively enhanced the response to visual targets irrespective of their location, suggesting a spatially non-specific enhancement of processing. The effects of attention and motivation on LIP activity were both predictive of changes in saccadic reaction times. These results suggest that attention and motivation exert distinct influences on visual representations in LIP, but that they both contribute to the preferential processing of behaviorally relevant visual stimuli. The data thus support the hypothesis that area LIP encodes a salience map of the visual world. / Dissertation

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 67-70).

Thesis (Ph. D.)--University of Wisconsin-Madison, 1953. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Thesis (M.S.)--University of Wisconsin--Madison, 1960. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 66).

Thesis (M.A.)--University of Wisconsin, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 76-78).

Thesis (M.S.)--University of Wisconsin, 1963. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 61-63).