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Previous research has indicated that the Masculine Gender Role Stress (MGRS) scale has been useful in identifying men who are susceptible to appraising threat in situations that challenge their masculine gender roles. Furthermore, Zillmann's excitation-transfer theory has proposed that elevated levels of physiological reactivity may interfere with men's appraisal processes and ability to control their emotions and behavior. Therefore, the primary purpose of this study was to examine the independent and combined effects of men's appraisal of threat and physiological pre-arousal on cognitive, affective, behavioral, and physiological responses to masculine relevant female partner behavior that challenges masculinity. Eighty college men who scored high or low on the MGRS were exposed to cold or room temperature water to induce the arousal or non-arousal conditions, respectively, prior to exposure to vignettes. They then listened to audio-taped vignettes of hypothetical situations involving dating partners who threatened the male's masculinity in the relationship in either masculine gender relevant or irrelevant contexts. Skin conductance level (SCL) and heart rate (HR) were obtained before, during, and after exposure to arousal or non-arousal conditions and each vignette. Measures of anger, negative affect, and appraisal were obtained in response to the different arousal conditions. Cognitive attributions, anger, negative affect, and verbal conflict tactics were obtained in response to each vignette. Results showed that the arousal condition produced greater HR than did the non-arousal condition. High MGRS men reported more negative affect and more negative appraisal in the arousal condition than in the non-arousal condition compared to low MGRS men. In response to the vignettes, high MGRS men reported more state anger, negative intent attributions, and verbal aggression tactics than did low MGRS men. Results also showed that gender irrelevant vignettes produced greater HR in the arousal condition than in the non-arousal condition. Finally, relative to high MGRS men, low MGRS men evidenced greater SCL during both arousal conditions and vignettes. However, results did not support an expected relationship between the effects of MGRS and pre-arousal on cognitive, affective, and physiological responses to gender relevant threats. Implications of these results for future research were discussed. / Ph. D.

Caffeine substantially affects cardiovascular functioning, yet wide variability exists in caffeine control procedures in cardiovascular reactivity (CVR) research. This study was conducted in order to identify a minimal abstention duration in habitual coffee consumers whereby CVR is unconfounded by caffeine; Six hours was hypothesized (average half-life). Thirty nine subjects (mean age: 20.9; 20 Women) completed a repeated measures study involving hand cold pressor (CP) and memory tasks. Caffeinated and decaffeinated coffee were administered. The following CV indices were acquired during baseline, task, and recovery epochs prior to coffee intake, 30 minutes-, and six hours post-intake: Heart rate (HR), high frequency heart rate variability (hfHRV), root mean squared successive differences (RMSSD), systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), pre-ejection period (PEP), left ventricular ejection time (LVET), and total peripheral resistance (TPR). Results support the adequacy of a six-hour abstention in controlling for caffeine-elicited CVR changes. The current study contributes to methodological endeavors in psychophysiology. Further investigations are crucial in establishing ideal caffeine controls, which would promote increasingly valid and reliable cross-study results. / Master of Science

Call number: LD2668 .T4 1986 D48 / Master of Science / Chemistry

The reactions of nitro complexes of nickel and palladium with CO have been examined to determine the mechanism(s) by which CO₂ is produced. The solution and solid state structures of square planar Ni(NO₂)₂(L)₂ reactants and pseudotetrahedral Ni(NO₂)(NO)(L)₂ products have been determined and related to their reactivity. Infrared, ³¹P{¹H}, and crystallographic data indicate rapid isomerization between nitro and nitrito bonding modes of the NO⁻₂ ligands. The crystal structures of Ni(NO₂)₂(PPh₂(Ch₂)₂PPh₂) (I), Ni(NO₂) (NO) (PMe₃)₂ (II), and [Ni(ONO) (NO) (PPh₂(CH₂)₂PPh₂]₂ (III), show the NO⁻₂ groups to be N-bonded in I and II and O-bonded in III. The nitrosyl ligands in II and III are non-linear (Ni-N-O = 165.5(8) ° and 153.4(8) °, respectively). Furthermore, III crystallizes as a dimer bridged by two phosphine ligands even though molecular weights show this complex to be monomeric in solution. Each Ni(NO₂) (NO) (L)₂ complex reacts with CO to produce stoichiometric amounts of Ni(NO₂) (NO) (L)₂ and CO₂. Rate date indicate the reaction proceeds associatively through formation of a carbonyl intermediate which has been directly observed in the reaction of Ni(NO₂)₂(P(C₆H₁₁)₃)₂ with CO. The reaction of C¹⁸O with Ni(NO₂)₂(PMe₃)₂ results in no incorporation of ¹⁸O into the nickel product while ¹⁸O is incorporated into CO₂ to form ¹⁸OC¹⁶O. The mechanism consistent with all of the data involves a rapid equilibrium between both forms of NO⁻₂ coordination followed by the reaction of CO with either isomer in the rate determining step to form a monocarbonyl complex. Irreversible oxygen atom transfer to CO and loss of CO₂ terminate the reaction. The corresponding square planar palladium complexes, Pd(NO₂)₂L₂, react with CO to form N₂O, CO₂ and novel tetranuclear palladium clusters (Pd₄(CO)₅L₄). A crystal structure of Pd₄(CO)₅ - (PMePh₂)₄ shows the cluster to be a distorted tetrahedron of metal atoms with one open edge and the five remaining edges each bridged by a carbonyl group.

Principles of transition metal electronic structure are presented to enable an understanding of the activation of C-H and C=C bonds by metals. A multitechnique approach utilizing core and valence photoelectron spectroscopies (p.e.s.) and molecular orbital calculations has been used to gain these insights. In the first half of the dissertation three principles are developed: ligand additivity, core-valence ionization correlation, and ring methylation. In the latter half of the dissertation these principles are seen to be crucial for understanding ionization data for the C-H and C=C activated species. Additive (with respect to ligand substitution) electronic effects, including additive core and valence ionization potentials, are shown in the p.e.s. of phosphine substituted molybdenum carbonyls. These additive effects demonstrate that the electronic effects of ligand substitution are predictable from empirical models. The core-valence ionization correlation enables direct comparison of XPS (core) and UPS (valence) ionization data and allows separation of bonding and overlap induced valence shift effects from Coulombic and relaxation shift effects. In the study of trimethylphosphine substituted cyclopentadienylmanganese tricarbonyl complexes, both the ligand additivity and core-valence ionization correlation principles are less valid than for the molybdenum carbonyl complexes because of loss of the very influential carbonyl backbonding. Methylation of the cyclopentadienyl ring in this system adds another independent variable of electronic structure perturbation and enables separation of the one-center and two-center Coulombic contributions to the core shifts. The above principles are used in the later chapters to show that the initial activation of the C-H bond in alkenylmanganese tricarbonyl complexes is dominated by the interaction of the C-H sigma bonding level with empty metal acceptor levels. The activation stops at the agostic stage rather than proceeding to full β-hydribe abstraction because there is, in these molecules, no gain in the number of pi electrons between the allyl and diene hydride endpoints of the abstraction cycle. Activation of the C=C bond in the cyclopentadienylmetal olefins is similar for Co and Rh complexes despite little similarity in the valence ionization spectra. The spectral differences are largely caused by the relaxation energy differences between Co and Rh. These complexes also provide interesting examples of electron delocalization through the metal. Permethylation of the cyclopentadienyl ring shifts the olefin pi ligand ionizations more than the expected Coulombic shift.

Graduation date: 1992

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Made available in DSpace on 2014-10-09T12:32:01Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:54Z (GMT). No. of bitstreams: 1 12899.pdf: 8071135 bytes, checksum: c51cd9839b73c11d92a566a85488515f (MD5) / Tese (Doutoramento) / IPEN/T / University of Michigan