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Background: Worry is theorised to function as a form of cognitive or experiential avoidance wherein an individual uses repetitive thinking in an attempt to avoid a future event or an aversive internal experience. There is evidence of a closer link between non-verbal thought (e.g. mental images) and emotion, physiology and behaviour than with verbal thought. Based on findings that worry is predominantly a verbal-linguistic activity, with less imagery occurring during worry episodes than during relaxation; it is theorised that worriers may move from non-verbal to verbal thought in order to avoid the greater arousal associated with non-verbal thought intrusions. This carries with it the unintended consequence of reducing emotional processing, leading to a subsequent increase in intrusive thoughts. Whilst cognitive science has emphasised the content of cognition and how this links to emotion, the psychological flexibility model suggests that content is less important than how we relate to our cognitive events. The degree to which we get entangled in our thinking, lack perspective on our thoughts and the degree to which cognition comes to regulate our behaviour over other sources is known as cognitive fusion. It is postulated that some individuals may be more prone to avoiding internal experiences due to the stance they take toward these experiences. In the long-term, worry should lead to a reduction in the experience of intrusive images and memories and an increase in intrusive thoughts; and this relationship should vary depending on an individual’s stance in relation to their internal experiences. The purpose of the current study is to explore the experience of intrusive memories, images and thoughts in an older adult sample, and the relationship of these experiences to level of worry, cognitive fusion and psychological inflexibility. Method: Sixty-two community dwelling older adults were involved in the study. Each completed questionnaire measures to assess level of trait worry, depression, cognitive fusion and psychological inflexibility, as well as an interview to determine whether diagnostic criteria were met for any mood or anxiety disorder and to complete an interview exploring the experience of intrusive memories, thoughts and images. Findings: Higher levels of trait worry were strongly associated with higher levels of cognitive fusion and psychological inflexibility. Intrusive memories, images and thoughts were all reported in low levels across the sample. Level of worry was positively associated with the severity but not the occurrence of intrusive memories and thoughts. Higher levels of psychological inflexibility were associated with less occurrence of intrusive memories and images; whereas higher levels of cognitive fusion were associated with the increased occurrence of intrusive images. Higher levels of worry, cognitive fusion and psychological inflexibility were all associated with increased severity of intrusive thoughts. The findings are discussed in relation to previous research and to the Avoidance Theory and Acceptance Model of GAD. Implications are considered for further research and clinical applications.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Science. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 309-324. / Ph.D.

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The building blocks of a sedimentary system are essential inputs into studies of reservoir character and comparisons with other sedimentary systems. Yet, our current knowledge of the building blocks of deep water slope channel deposits is still largely speculative. A quantitative approach has been utilised in order to analyse a host of lithological data and objectively identify these sedimentary components. The laterally-extensive and gently-dipping continental slope deposits of the San Fernando Channel System, Baja California, provide the required control on sub-seismic-scale temporal and lateral variations of lithofacies and 3D architecture. High resolution photo-panoramas (with better than 2mm accuracy) of the prominent conglomeratic component of the succession were collected from various key parts of the outcrop. Image analysis of segments extracted from the photo-panoramas generates key parameters for comparison of texture and fabric of conglomerates, such as clast to matrix ratio, major axis length and relative orientation. Statistical analysis of these data enabled the erection of an objective lithofacies scheme for the gravel fraction, the grouping of lithofacies into objectively-defined assemblages, and the establishment of models for the lateral and stratigraphic distributions of these assemblages. 12 lithofacies were objectively identified through hierarchical cluster analysis of 4 quantitative lithological parameters. Statistical analyses indicate significant differences in diversity in the lithofacies assemblages between the early and later parts (termed Stage 1 and Stage 2) of a channel complex set (sensu Sprague, et al., 2002), and to a lesser extent between marginal and axial parts of the system. These can be related to spatial differences and temporal changes in the nature of the turbidity currents flowing through the channel system. Gravelly units become more organised and less diverse with time in one CCS, and each successive CCS more organised at earlier stratigraphic levels than the next, except for the last CCS which is interpreted as influenced by a tectonic paroxysm. These seemingly autocyclic changes in organisation are interpreted as process-responses to changes in equilibrium profile as the nature of confinement changes with the infilling of an initial erosional confinement, to confinement by a master levee and gradual infilling through the evolution of each CCS.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / In this paper are described the effects that solar and lunar intrusions have on statistical analysis of the data. The NASA ACTS experiment focuses on the 20 and 27 GHz radiometer and beacon. The experiment is currently compiling a database for the attenuation for these different channels. For the year of 1994 our sight obtained 86.5 hours of attenuation and for 1995 our sight obtained 77 hours of attenuation. The total amount of interference time for sun/lunar intrusions for 1994 and 1995 was respectively, 39 hours and 38.5 hours, which is nearly half the total amount of attenuation due to rain and cloud fades. It is clear to see why this data must be taken out for any type of statistical analysis of the data.

published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

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Rare earth elements (REE) are an increasingly important group of metals due to their role in the development of modern technologies. Despite being abundant within the Earth’s crust recoverable ores are uncommon, and their mineralization isn’t as well understood as other abundant ore types. In this work, the mineralization of REE occurring in outcrop samples at Hicks Dome, a cryptoexplosive feature that resides in the Wauboukigou Alnöite Province in southeastern Illinois, was studied to determine the mode of mineralization and the origin of the REE. Xenotime-(Y) was identified with a scanning electron microscope in an intrusive breccia and emplaced during or shortly after the uplift which created the oval doming of the Paleozoic section. Whole rock REE concentrations from ultramafic dikes at Hicks Dome closely match global averages of lamprophyres and carbonatites, with a steep La to Lu slope, and enrichment of light rare earth elements. Hicks Dome has unique characteristics relative to the other intrusions in the Province, such as elevated REE, Th, and doming. These traits indicate that the dome was more closely related to an intrusive body at depth that sourced heat, volatile gases, and a suite of rare elements. Based on these data, the REE mineralization and thorium associated with the siliceous breccia is directly related to the alkaline ultramafic intrusion at Hicks Dome. The volatile rich, hot fluids emanating from the ultramafic magma supplied REE and thorium were mixed with the regional fluids responsible for the IKFD.