5,295 research outputs found
Contra Epstein, Good Explanations Predict
Epstein has argued that an explanation\'s capacity to make predictions should play a minor role in its evaluation . This view contradicts centuries of scientific practice and, at least, decades of philosophy of science. We argue that the view is not only unfounded but seems to arise from a mistaken fear that ABM models are in need of defense against the criticism that they don\'t necessarily forecast events in the natural or social world.ABM, Agent Based Model, Modeling, Prediction, Explanation, Philosophy of Science
The emergence of insect resistance in Bt-corn: implication of resistance management information under uncertainty
"The successful management of transgenic technology is likely to depend on the economic behavioral response of farmers to the regulated use of transgenic crops. A well-studied example is the widespread use of Bt-corn, in the United States, and elsewhere, to control the European Corn Borer, a major corn pest. The extensive use of Bt-corn has led to concerns about the emergence of insect resistance. The United States Environment Protection Agency addressed this potential problem by developing an insect resistance management strategy, based, in part, on complex mathematical models using detailed biological assumptions about the population genetics and life history of the European Corn Borer. However, seed companies and others have sometimes used simpler deterministic profit models to justify the economics of Bt-corn to potential growers. Therefore an over reliance, by regulatory agencies, on complex modeling approaches may obscure the likely economic behavioral response of farmers who rely on these less complex models. However, the determinants of adoption are numerous, profit being one of them. We develop a simple model for the spread of resistance based on the logistic growth equation and use it to investigate the effect of uncertainty on farmer decisions to plant Bt-corn and follow EPA management rules. The model results suggest that planting Bt-corn is an optimal strategy under the type of uncertainty assumed in the model and that short-term economic behavior is likely to lead to the Environment Protection Agency management rules not being followed. Our results add weight to existing work on this problem." Authors' AbstractBt-corn, logistic growth, Monte Carlo methods, Corn, Environmental protection, Economics Methodology,
Early Modern Masculinities in 1 and 2 Henry IV
Early modern ideals of masculinity were notably inconsistent, and often contradictory, yet remained prominently embedded within the ideology of Elizabethan England. This thesis focuses on how Shakespeare’s 1 and 2 Henry IV expose the dangerous consequences of these ideals when situated in competition with one another by reproducing them during a period of intense civil upheaval. These plays reveal the deficiencies of conventional models of masculinity, particularly through the characters of Falstaff and Percy, as well as the need for a new model of masculinity that can provide the state with order and stability. The resulting Machiavellian ideal, which Hal constructs from other competing ideals, is a model of masculinity that operates according to a principle of control, both in the political sense and over oneself. Percy’s death and Falstaff’s banishment signal the emergence of Hal’s Machiavellian ideal as a more effective model of masculinity, which flourishes not through prescribed notions of manhood but by actively negotiating the beneficial or destructive aspects of particular ideals, combining them in accordance with an ever-changing society. By tracing these changes, masculinity is revealed as a composite of many ideological registers that depend on ideas of, among others, bodies, language, and politics
Land Cover Change During a Transition in Land Management at Valles Caldera 1989-2013
This study examines how land-use policies can play a role in manifesting physical landscape changes. In 2000, Congress enacted a unique experiment in public lands management by creating the Valles Caldera National Preserve and its governing body, the Valles Caldera Trust (VCT). The management approach enacted by Valles Caldera Trust marked a significant departure in land-use intensity. To assess how these changes in management have affected land-use intensity and resulting cover change, this research seeks to identify landscape-level changes that taken place during a period of ten years prior to and following the formation of the Valles Caldera National Preserve (i.e., 1989-2013). Remote sensing techniques were used to quantify land cover transitions. Landsat image data (30m) from 1989, 1999, 2003, and 2013 were compared to identify changes that have taken place between the time periods 1989-1999, a period just prior to the purchase of the Baca Ranch by the federal government, and 10 years of management by the Valles Caldera Trust, 2003-2013. In order to do this, pre-classification change detection was used to quantify changes that have taken place during each period and a range of historical evidence used to classify those changes by disturbance regime. Results demonstrate an increase in wetland and rangeland recovery under VCT management based on evaluating several ancillary datasets. This leads to the conclusion that adaptive management strategies were beneficial for these cover types. The impact of the VCTs adaptive management strategies on forests is difficult to understand due to large wildfire-induced cover changes that occurred during VCT management.\u2
The Molecular Nature of Tumorigenesis
This paper is an exploration of the molecular aspects behind the tumor development process. Robert Weinberg provides an in-depth analysis of the subject matter over a series of publications entitled The Hallmarks of Cancer, The Hallmarks of Cancer: the next generation, and The Biology of Cancer. Current therapy development in the context of the hallmarks of cancer are discussed. The paper espouses some theories about the main differences between pediatric and adult cancers, specifically dealing with the mortality rates. The molecular aspects of tumorigenesis are discussed with particular attention to the tumor suppressor protein p53. This flows into the current treatment of cancer and how the future of cancer therapy development lies in novel concepts such as p53-induced apoptosis. Finally, some major methods of cancer prevention are presented because a reduction in the incidence of cancer, rather than improvements in current therapeutic techniques provide the best prospects for a reduction in cancer-associated mortality. Prevention is the cure.B.S
Levels of Organization in the Song of the Bobolink (Icteridae: Dolichonyginae)
By comparison with other icterids, the bobolink (Dolichonyx oryzivorus) sings an unusually long and complex song. The songs of four male bobolinks were analysed in terms of units at four different levels of analysis: the figure, the figure-sequence, the song-pattern, and the song. The different levels of analysis show different degrees of stereotypy and variation. Individual males in the study area differed in the frequency of use of the different song-patterns and in the way they assembled them into songs. Immediate repetition of song patterns within a song was unusual. Songs sung from fixed perches were shorter than songs sung in flight. The results suggest that the length of bobolink song is in part a consequence of its use of the song as a part of an elaborate flight display, and that the unit we called the “song-pattern” was closest to the unit designated “song” in most other species
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