8 research outputs found
Ratingcurve: A Python Package for Fitting Streamflow Rating Curves
Streamflow is one of the most important variables in hydrology, but it is difficult to measure continuously. As a result, nearly all streamflow time series are estimated from rating curves that define a mathematical relationship between streamflow and some easy-to-measure proxy like water surface elevation (stage). Despite the existence of automated methods, most rating curves are still fit manually, which can be time-consuming and subjective. Although several automated methods exist, they vary greatly in performance because of the non-convex nature of the problem. In this work, we develop a parameterization of the segmented power law that works reliably with minimal data, which could serve operationally or as a benchmark for evaluating other methods. The model, along with test data and tutorials, is available as an open-source Python package called ratingcurve. The implementation uses a modern probabilistic machine-learning framework, which is relatively easy to modify so that others can improve upon it
Experimental study of ostensibly shamanic journeying imagery in naďve participants II: phenomenological mapping and modified affect bridge
This study develops the methodological framework advanced in Rock, Baynes, and Casey\u27s (2005) experimental study of ostensibly shamanic journeying imagery in naïve participants. Specifically, the present study experimentally investigates the impact of the word landscape, featured in Harner\u27s (1990) shamanic journeying to the Lower World instructions, on the number of landscape-related images reported; examines the origins of ostensibly shamanic journeying images; and maps the phenomenological state effects of shamanic journeying to the Lower World. Sixtyeight naïve participants were randomly assigned to one of three conditions: either the original or a revised version of Harner\u27s (1990) instructions coupled with monotonous percussion drumming at 8 beats-per-second for 15 minutes, or sitting quietly with eyes open for 15 minutes. Each participant\u27s subjective experience was retrospectively assessed using the Phenomenology of Consciousness Inventory (PCI) (Pekala 1991) and a mental imagery checklist. Subsequently, participants were administered the Modified Affect Bridge for the purpose of exploring the origins of mental imagery experienced during the experimental conditions. The results indicated that there was a statistically significant difference between conditions with regard to the number of ostensibly shamanic journeying images reported, but not between treatment conditions with regard to the number of landscaperelated images reported. There were no significant relationships between condition and mental imagery derived from autobiographical memories. There were statistically significant differences between conditions with regard to the PCI dimensions of fear, altered state of awareness, and arousal.<br /
Adenine mononucleotides and their metabolites liberated from and applied to isolated tissues of the mammalian brain
Experimental study of ostensibly shamanic journeying imagery in naďve participants I: antecedents
The purpose of the present study was to investigate experimentally the antecedents of ostensibly shamanic journeying imagery associated with the Lower World in naïve participants. Forty six participants completed a composite questionnaire consisting of demographic items and the Tellegen Absorption Scale (Tellegen and Atkinson 1974). Participants were randomly assigned to one of five conditions: Harner\u27s (1990) shamanic journeying to the Lower World instructions coupled with monotonous percussion drumming at either 4 or 8 beats-per-second for either 10 or 15 minutes; and sitting quietly with eyes closed for 15 minutes. Participants\u27 phenomenology was retrospectively assessed using the Phenomenology of Consciousness Inventory (Pekala 1991) and a mental imagery checklist. The results indicated that there was a statistically significant difference between conditions with regards to the number of ostensibly shamanic journeying images. After adjusting for Harner\u27s (1990) instructions, a significant main effect was found for both beats-per-second and time with regards to the number of ostensibly shamanic journeying images reported. There was a statistically significant relationship between condition and the tendency to report mental imagery associated with rocky ravines, predatory creatures, and rivers. Religious devotion was found to be a significant predictor of the number of ostensibly shamanic journeying images reported. Religious exposure and trait absorption were significant predictors of altered experience. Implications of the findings are discussed and suggestions for future research advanced.<br /
Shamanic journeying imagery, constructivism and the affect bridge technique
Shamanic journeying imagery arguably occurs across cultures and historical epochs. However, to what extent is the content of the journeying imagery a construction of the shaman\u27s cultural milieu, belief structures, autobiographical memories, and so forth. The present article finds the literature inconclusive on this question. It is suggested that attempts to answer it face a fundamental methodological problem: how to detect contextual influences on imagery that the shaman cannot report on because they are outside his/her present consciousness and memory. The authors propose a partial solution: Watkins\u27 (1971) Affect Bridge, a memory “uncovering” technique used in hypnosis. A non-hypnotic version of the technique developed by one of the authors for inquiry into shamanic journeying imagery is then described.<br /