What to expect when you’re prospecting: how new information changes our estimate of the chance of success of a prospect

There is a common belief that we can expect to add value to a prospect or prospect portfolio by improving the prospect chance of success (Pg) as a consequence of acquiring information and doing work. Established laws of probability dictate that this is incorrect. We do expect new information to add value to the exploration cycle, but not by an expectation of improving the prospect risk. New information may result in an increase or a decrease of Pg, but the expected result (the average of all possible outcomes) is zero change. Moreover, for a typical exploration prospect (Pg <0.5), we expect that new information will downgrade more prospects Pg than are upgraded. Real-world prospect data are neither suitable nor publically available to study this. Instead, the concept is explored using an analogous process (prenatal prediction of fetus gender) for which good statistics exist, and by creating a synthetic prospect that can be analyzed in a repeatable way. The results support the predictions made above

Foreword

Early Middle Cambrian bituminous coquinoid limestones from a tectonically isolated outcrop in southwestern Kyrgyzstan yield a remarkably diverse fauna, with stem-group cnidarians, trilobites, rhynchonelliformean brachiopods, and other shelly fossils. The fossil site is in the northern foothills of the Turkestan Range and thus forms part of the westernmost extension of the South Tien Shan. The fauna includes two fairly well known trilobite species, Glabrella ventrosa Lermontova, 1940 and Dorypyge richthofeniformis Lermontova, 1940, that provide confident support for an Amgan age of the rocks. New described taxa include the stem-group cnidarian Cambroctoconus kyrgyzstanicus Peel sp. nov., the trilobite Olenoides sagittatus Geyer sp. nov., and the helcionelloid Manasoconus bifrons Peel gen. et sp. nov. Additional fossils within the samples include the trilobites Olenoides sp. A, Kootenia sp., and Pseudoeteraspis? sp.; the rhynchonelliform brachiopods Narynella cf. ferganensis (Andreeva, 1962), Narynella? sp., Austrohedra? sp. nov., and two species of uncertain generic affinity; the tommotiid Tesella sp.; the hyolithelminth Hyolithellus sp.; and the palaeoscolecid Hadimopanella oezgueli Gedik, 1977. Of particular interest is Cambroctoconus kyrgyzstanicus with an octagonal corallum and a sparsely septate calyx

A practical guide to the use of success versus failure statistics in the estimation of prospect risk

Statistical data documenting past exploration success and failure can be used to inform the estimate of future chance of success, but this is not appropriate to every situation. Even where appropriate, past frequency is not numerically equivalent to future expectation unless the sample size is very large. Using the Rule of Succession of Laplace (1774), we calculate the appropriate predicted chance of future success that can be used for smaller sample numbers, typical of exploration data sets, which include both successes and failures. The results, presented as a simple look-up table, show that the error which would result from using simple frequency instead of the appropriately calculated value is particularly severe for small samples (>10% error arising if n< 9). This error is least if past success rate is close to 0.5 but it increases markedly if the past data consist of mostly failure or mostly success. We review the conditions in which past frequency can be used as a guide, and the circumstances in which it does not reflect future chance. Past success frequency should only be used as a guide to future chance if the past tests and future opportunities belong to the same play, and are similar as far as the available data allow. They should not be used if the historical tests have selectively sampled the “cream” of the pool of opportunities

Transboundary Movement of Atlantic Istiophorid Billfishes Among International and U.S. Domestic Management Areas Inferred from Mark-Recapture Studies

Billfish movements relative to the International Commission for the Conservation of Atlantic Tunas management areas, as well as U.S. domestic data collection areas within the western North Atlantic basin, were investigated with mark-recapture data from 769 blue marlin, Makaira nigricans, 961 white marlin, Tetrapturus albidus, and 1,801 sailfish, Istiophorus platypterus. Linear displacement between release and recapture locations ranged from zero (all species) to 15,744 km (mean 575, median 119, SE 44) for blue marlin, 6,523 km (mean 719, median 216, SE 33) for white marlin, and 3,845 km (mean 294, median 98, SE 13) for sailfish. In total, 2,824 (80.0%) billfish were recaptured in the same management area of release. Days at liberty ranged from zero (all species) to 4,591 (mean 619, median 409, SE 24) for blue marlin, 5,488 (mean 692, median 448, SE 22) for white marlin, and 6,568 (mean 404, median 320, SE 11) for sailfish. The proportions (per species) of visits were highest in the Caribbean area for blue marlin and white marlin, and the Florida East Coast area for sailfish. Blue marlin and sailfish were nearly identical when comparing the percent of individuals vs. the number of areas visited. Overall, white marlin visited more areas than either blue marlin or sailfish. Seasonality was evident for all species, with overall results generally reflecting the efforts of the catch and release recreational fishing sector, particularly in the western North Atlantic. This information may be practical in reducing the uncertainties in billfish stock assessments and may offer valuable insight into management consideration of time-area closure regulations to reduce bycatch mortality of Atlantic billfishes

Cell interactions and the response to ecolysteroids of 'Drosophila' imaginal disc cell lines

This thesis is a study of the biology of Drosophila imaginal disc cells growing as continuous cell lines. Their morphological characteristics and cellular properties were analysed in order to characterise the cells in vitro. Morphological analysis of the cells revealed several cell types within the original cell lines perhaps representing a diversity in the cellular origin of these cells. A new cloning technique was devised which enabled a single imaginal disc cell to give rise to new cell line and indicated that a single cell could give rise to the different cell types seen in culture. This indicates that the diversity in morphology of the cells in culture was an indication of the conditions in culture rather than as a result of cellular diversity. The original cell lines and the newly derived cloned cell lines were subjected to the insect moulting hormone 20-HE in order to ascertain the degree of differentiation that was possible in culture. The cells showed a dramatic morphological response to hormone, they elongated, began to aggregate and threw out cell processes. This is combined with concomitant biochemical changes in the cell lines, including the induction of chitin synthesis and acetylcholinesterase. The cells in culture show a characteristic pattern of aggregation which was studied at the ultrastructural level using electron microscopy. These studies and also immunofluorescence of cell aggregates indicated the prevalence of cell processes and a role was postulated for their action in bringing about these aggregates. Aggregation was also correlated with the expression of PS integrins, which are well characterised Drosophila adhesion molecules. The adhesive properties of the cells were further characterised with reaggregation experiments in different media as a prelude to setting up cell sorting assays between wing and leg cell lines. This proved somewhat inconclusive but pointed to some sorting out occurring between wing and leg cells

Stable variational solutions of the Dirac equation.

Dept. of Physics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1984 .P445. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.Sc.)--University of Windsor (Canada), 1984

Evaluating Catchment Models as Multiple Working Hypotheses: on the Role of Error Metrics, Parameter Sampling, Model Structure, and Data Information Content

To evaluate models as hypotheses, we developed the method of Flux Mapping to construct a hypothesis space based on dominant runoff generating mechanisms. Acceptable model runs, defined as total simulated flow with similar (and minimal) model error, are mapped to the hypothesis space given their simulated runoff components. In each modeling case, the hypothesis space is the result of an interplay of factors: model structure and parameterization, chosen error metric, and data information content. The aim of this study is to disentangle the role of each factor in model evaluation. We used two model structures (SACRAMENTO and SIMHYD), two parameter sampling approaches (Latin Hypercube Sampling of the parameter space and guided-search of the solution space), three widely used error metrics (Nash-Sutcliffe Efficiency - NSE, Kling-Gupta Efficiency skill score - KGEss, and Willmott refined Index of Agreement - WIA), and hydrological data from a large sample of Australian catchments. First, we characterized how the three error metrics behave under different error types and magnitudes independent of any modeling. We then conducted a series of controlled experiments to unpack the role of each factor in runoff generation hypotheses. We show that KGEss is a more reliable metric compared to NSE and WIA for model evaluation. We further demonstrate that only changing the error metric -- while other factors remain constant -- can change the model solution space and hence vary model performance, parameter sampling sufficiency, and or the flux map. We show how unreliable error metrics and insufficient parameter sampling impair model-based inferences, particularly runoff generation hypotheses