Dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg for the Degree of Master of Science / Various techniques and procedures suited to monthly forecasting are investigated and tested. These include using the products generated by atmospheric general circulation models during a 17-year hindcast experiment, and downscaling the forecast circulation to regional rainfall in South Africa using circulation indices and canonical correlation analysis. The downscaling methods are evaluated using the cross-validation technique. Various model forecast bias-correction methods and skill-enhancing ensemble techniques are employed to improve the 30-day prognosis of the model. Forecasts from the general circulation model and each technique are evaluated. Those demonstrating reasonable skill over the southern Africa region, and which are feasible when considering available resources, are adopted into a strategy which can be used operationally to produce monthly outlooks. Various practical issues regarding the operational aspects of long-term forecasting are also discussed. / Andrew Chakane 2019

Fishers (Pekania pennanti) are a species of concern in the Sierra Nevada Mountains of California. Cortisol is a glucocorticoid hormone released to mobilize energy in response to stress and has been used as an indication of an individual’s physiological response to its environment. By collecting samples of fisher hair and measuring an individual’s cortisol, we examined the physiological stress response of the animals to human disturbances (housing density, road density, habitat type, and silvicultural treatements) and drought (tree mortality) in their home ranges. Using AICc model selection, we found that levels of tree mortality within a fisher’s home range significantly influenced cortisol levels. Various human disturbances had a smaller effect on cortisol levels. Furthermore, we examined the relationship between cortisol and fitness through the metrics of body condition, female kit counts, and survival. We found that females with low cortisol had significantly higher survival rates than females with medium and high cortisol. With the recent drought, bark beetle infestation and subsequent tree mortality being >80% in some areas of our study, cortisol levels could continue to increase, potentially leading to further decreased fitness within this fisher population. We also examined the difference in habitat selection between the core and entirety of the home ranges and found that fishers prefer late-successional forest in the core of their home ranges.

The purpose of this thesis is t o describe the occurrences, interrelationships, and possible origin of the metallic mineral deposits of the Bear River Range. In this study, 21 mineral deposits containing minerals of lead, iron, copper, manganese, and zinc with quartz and carbonate gangue minerals, are described and classified as low temperature epigenetic hydrothermal deposits. The deposits predominantly occur in Cambrian limestone and dolomite formations located below formations with a high shale content. The deposition occurred as fracture filling and replacement along fractures associated with Teritary Basin and Range normal faults and joints which generally trend northerly in the range. No zoning of the deposits was observed. No obvious source for the mineralizing solutions was observed; however, the presence of iron and magnesium minerals in all of the deposits may suggest the possibility of a metamorphic origin. The deposits are dated as post-Eocene.

Seven Cambrian formations and two Ordovician formations, with a total thickness of 9,000 feet, crop out west of the Paris thrust fault and comprise the upper plate. Slices of three Ordovician formations, one Silurian formation, two Mississippian formations, and one formation each of Pennsylvanian and Permian age comprise the low plate. Mesozoic units are not present in the mapped area. Two Tertiary formations and unconsolidated Quaternary deposits are also present. The major structural feature is the Paris thrust fault which extends north-south throughout the area. It was active during the Laramide orogeny. This fault involved eastward movement and placed Cambrian over Ordovician and later Paleozoic strata. The oldest formation exposed in the upper plate is the Brigham Formation which generally rests on the Garden City Formation. All units of the lower plate have been severely distorted and displaced by folding, thrusting, and reverse faulting. Both horizontal compression and gravity sliding have been invoked to explain this deformation. Gravity sliding is favored by many geologists; however, an uplifted source area has not been identified. Later, gravity faulting produced the major topographic features of the area today, notably the Bear River Range and Bear Lake Valley. (76 pages)

The upper Colorado River drainage system yields approximately 104,000 acre-feet of silt annually to the Colorado River. In an attempt to reduce the silt load, federal land management agencies have installed numerous land surface treatments. A study was conducted to measure the economic benefits of the land treatments near Cisco, Utah, and to compare them to the treatment costs and to develop predictive criteria for estimating the optimum intensity of treatment. The economic evaluation was done in a benefit-cost framework and the criteria for estimating optimum intensity of treatment was done in a production-function framework. The land treatments were found to be effective in retaining silt, but treatment apparently resulted in decreased livestock carrying capacity. Over-all, the land treatments were found to be uneconomical.

The geological column in northern Utah has had very little detailed study. Those who have made reports on this section have done so only in a very general way, making no detailed sections of any part of the column, excepting that of the Cambrian made by Walcott. Other work has been done by Mansfield in southeastern Idaho and a general section of the Devonian made in Green Canyon, Bear River Range, Utah by kindle.

Master of Science / Most studies of condylar movement are based on the movement of an arbitrary condylar point. As the condyle is a 3-dimensional body which undergoes complex rotations and translations in function, the movement of one point in the vicinity of the condyle may not accurately represent condylar movement. The aims of this investigation were to determine in human subjects, during open-close and excursive jaw movements, the movement patterns of arbitrary and anatomical condylar points; and whether the trajectory of a single selected point can accurately reflect the movement of the condyle. In 44 subjects, condylar point movements were recorded with an opto-electronic tracking system (JAWS3D), which recoded the position of three light-emitting diodes attached to each dental arch. The primary point, selected to represent movement of the condyle, was 15 mm medial to the palpated lateral condylar pole, parallel to the Frankfort horizontal plane. Additionally, four points were selected along orthogonal axes in the sagittal plane, and four in the horizontal plane: each was 5 mm from the primary point. In two subjects, the mandibular condyles were imaged by computerised tomography (CT) and the lateral and medial poles, most superior, anterior and posterior points of their condyles were selected. The trajectories of each point were compared for each subject for the mandibular movements listed above. Variability in both path form and dimension was noted between the subjects for all mandibular movements. For example, in an open-close mandibular movement the condylar point translation varied in the antero-posterior direction between 1.8-22.8 mm, and in the supero-inferior direction between 4.5-12.1 mm. For each subject, the pathway of each point was different in form and dimension from that subject’s other condylar points for the open-close, and ipsilateral lateral mandibular movements. For the open-close movement, in only four of the 44 subjects were the arbitrary point traces similar in form within a subject; and the tracings of each subject’s condylar points showed, on average, a 3.2 mm difference in maximal horizontal (i.e. antero-posterior) translation and 2.9 mm in maximal vertical (i.e. supereo-inferior) translation. For contralateral lateral mandibular movements, the path form and dimension in the sagittal plane of the condylar points were similar within a subject; however the lateral component showed variability in path length for the different points within a subject. The pathways of the condylar points for a protrusive movement displayed the most similarity within a subject, with an average of 0.4 mm variation in maximal horizontal or vertical displacement between each subject’s arbitrary condylar points’ tracings. The anatomical condylar points of the two subjects showed variability between and within each subject. For these two subjects the trajectories of the arbitrary condylar points moved in directions similar to the anatomical points of all movements except for the ipsilateral lateral mandibular movement, where in one subject, the arbitrary condylar points moved posteriorly, inferiorly and laterally whereas the anatomical points moved anteriorly, inferiorly and laterally. There is much variability in both form and dimension for mandibular condylar movement between human subjects. There is also considerable variability within subjects in the form and dimension of condylar point movement, whether arbitrary or anatomical, depending on the point selected. By inference therefore, a single condylar point cannot accurately reflect the movement of the mandibular condyle, except perhaps for a protrusive mandibular movement. Multiple mandibular points are therefore required to describe the motion of the condyle. In an ipsilateral lateral mandibular movement, for example, an arbitrary point may move in a completely different direction to the mandibular condyle, and so anatomically derived condylar points should be utilised to assess accurately condylar movement.

Uncertainty is inherent in many novel and important applications such as market surveillance, information extraction sensor data analysis, etc. In the recent a few decades, uncertain data has attracted considerable research attention. There are various factors that cause the uncertainty, for instance randomness or incompleteness of data, limitations of equipment and delay or loss in data transfer. A probabilistic threshold range aggregate (PRTA) query retrieves summarized information about the uncertain objects in the database satisfying a range query, with respect to a given probability threshold. This thesis is trying to address and handle this important type of query which there is no previous work studying on. We formulate the problem in both discrete and continuous uncertain data model and develop a novel index structure, asU-tree (aggregate-based sampling-auxiliary U-tree) which not only supports exact query answering but also provides approximate results with accuracy guarantee if efficiency is more concerned. The new asU-tree structure is totally dynamic. Query processing algorithms for both exact answer and approximate answer based on this new index structure are also proposed. An extensive experimental study shows that asU-tree is very efficient and effective over real and synthetic datasets.

The development of some ability for forecasting low rainfalls would be helpful in Tuvalu as rainwater is the only source of fresh water in the country. The subsurface water is brackish and saline so the entire country depends totally on rainwater for daily domestic supplies, agricultural and farming activities. More importantly, these atolls are often influenced by droughts which consequently make inadequate drinking water an issue. A simple graph-based forecasting scheme is developed and presented in this thesis for forecasting below average mean rainfall in Funafuti over the next n-month period. The approach uses precursor ocean surface temperature data to make predictions of below average rainfall for n = 1, 2 12. The simplicity of the approach makes it a suitable method for the country and thus for the Tuvalu Meteorological Service to use as an operational forecasting tool in the climate forecasting desk. The graphical method was derived from standardised monthly rainfalls from the Funafuti manual raingauge for the period January 1945 to July 2007. The method uses lag-1 and-lag 2 NINO4 sea surface temperatures to define whether prediction conditions hold. The persistence of predictability tends to be maintained when the observed NINO4 ocean surface temperatures fall below 26.0oC. Although the developed method has a high success probability of up to 80 percent, this can only be achieved when conditions are within the predictable field. A considerable number of below average rainfall periods are not within the predictable field and therefore cannot be forecast by this method. However, the graphical approach has particular value in warning when an existing drought is likely to continue.

Gravity measurements made during 1979 and 1980, combined with existing gravity measurements, provide data for the interpretation of upper crustal structures relevant to the assessment of the geothermal potential of south-central Oregon. West of Upper Klamath Lake, free-air gravity anomalies trend north-south and average near 35 mgals. East of Upper Klamath Lake, free-air gravity anomalies trend west to northwest, and average near ten mgals. The complete Bouguer anomaly field exhibits a regional gradient of nearly .4 mgals/km, which is attributed to the existence of a low-density upper mantle layer beneath the Basin and Range province. The large northwest-trending negative anomaly associated with the Klamath graben suggests a depth of low-density fill of up to 2300 m (7500 feet). The regional gravity field exhibits a broad regional high over the area surrounding Klamath Falls which may be caused by a shallow mantle or a large intrusive body at depth, or may simply be due to intense silicification of the area by thermal waters. The residual anomaly field exhibits broad bands of positive anomalies which enclose the negative anomaly associated with the Klamath graben. The easternmost of these broad, positive trends may correspond to the eastern flank of an anticline which may have existed prior to graben faulting. Positive anomalies west of the graben coincide with the Mount McLoughlin lineament. A large positive anomaly located south of Sprague River is interpreted to be a volcanic center and the heat source for thermal waters found in the Sprague River Valley. A two-dimensional cross section near 42°26' N. latitude suggests that step-like faults form the west side of the Klamath graben. The model indicates the presence of a high density body south of Sprague River that is interpreted to be a buried volcanic source for local extrusive volcanic rocks. Northwest-trending gravity anomalies west of Upper Klamath Lake indicate that structural trends of the Basin and Range province extend into the Cascade Mountains, and suggest that a heat source for thermal waters may exist beneath the High Cascades, rather than beneath the areas which exhibit geothermal activity. / Graduation date: 1982