Structuring Decisions Under Deep Uncertainty

Innovative research on decision making under ‘deep uncertainty’ is underway in applied fields such as engineering and operational research, largely outside the view of normative theorists grounded in decision theory. Applied methods and tools for decision support under deep uncertainty go beyond standard decision theory in the attention that they give to the structuring of decisions. Decision structuring is an important part of a broader philosophy of managing uncertainty in decision making, and normative decision theorists can both learn from, and contribute to, the growing deep uncertainty decision support literature

Building on Cram's legacy: stimulated gating in hemicarcerands.

CONSPECTUS: Donald Cram's pioneering Nobel Prize-winning work on host-guest molecules led eventually to his creation of the field of container molecules. Cram defined two types of container molecules: carcerands and hemicarcerands. Host-guest complexes of carcerands, called carceplexes, are formed during their synthesis; once a carceplex is formed, the trapped guest cannot exit without breaking covalent bonds. Cram defined a quantity called constrictive binding, arising from the mechanical force that prevents guest escape. The constrictive binding in carceplexes is high. In contrast, hemicarcerands have low constrictive binding and are able to release the incarcerated guests at elevated temperatures without breaking covalent bonds. We have designed molecules that can switch from carcerand to hemicarcerand through a change in structure that we call gating. The original discovery of gating in container molecules involved our computational studies of a Cram hemicarceplex that was observed to release a guest upon heating. We found that the side portals of this hemicarceplex have multiple thermally accessible conformations. An eight-membered ring that is part of a portal changes from a "chair" to a "boat" structure, leading to the enlargement of the side portal and the release of the guest. This type of gating is analogous to phenomena often observed with peptide loops in enzymes. We refer to this phenomenon as thermally controlled gating. We have also designed and synthesized redox and photochemically controlled gated hemicarceplexes. Gates are built onto host molecules so that the opening or closing of such gates is stimulated by reducing or oxidizing conditions, or by ultraviolet irradiation. In both cases, the appropriate stimuli can produce a carceplex (closed gates) or hemicarceplex (open gates). A hemicarceplex with closed gates behaves like a carceplex, due to its very high constrictive binding energy. When the gates are opened, constrictive binding is dramatically lowered, and guest entrance and exit become facile. This stimulated switching between open and closed states controls access of the guest to the binding site. The experimental and computational investigations of gated hemicarcerands and several potential applications of gated hemicarceplexes are described in this Account

February 1996

Edward Said, keynote address at the second Macalester International Roundtable. Story on page 16.https://digitalcommons.macalester.edu/mactodaycovers/1038/thumbnail.jp

Why Simpler Computer Simulation Models Can Be Epistemically Better for Informing Decisions

For computer simulation models to usefully inform climate risk management, uncertainties in model projections must be explored and characterized. Because doing so requires running the model many ti..

November 1997

Laurie Brown \u2787, environmental activist by the Lake of the Isles. The Minneapolis Park Board is restoring the lake to its original condition. Story on pages 21-32.https://digitalcommons.macalester.edu/mactodaycovers/1045/thumbnail.jp

Fall 2001

Songwriter Ben Connelly \u2792 photographed in Minneapolis. Story on page 20.https://digitalcommons.macalester.edu/mactodaycovers/1060/thumbnail.jp

May 1993

Michelle McGovern \u2793 and Professor John Craddock \u2780 examine sedimentary rocks with a microscope and computer. Story on page 8.https://digitalcommons.macalester.edu/mactodaycovers/1027/thumbnail.jp

Towards Best Practice Framing of Uncertainty in Scientific Publications: A Review of Water Resources Research Abstracts

Uncertainty is recognized as a key issue in water resources research, amongst other sciences. Discussions of uncertainty typically focus on tools and techniques applied within an analysis, e.g. uncertainty quantification and model validation. But uncertainty is also addressed outside the analysis, in writing scientific publications. The language that authors use conveys their perspective of the role of uncertainty when interpreting a claim —what we call here “framing” the uncertainty. This article promotes awareness of uncertainty framing in four ways. 1) It proposes a typology of eighteen uncertainty frames, addressing five questions about uncertainty. 2) It describes the context in which uncertainty framing occurs. This is an interdisciplinary topic, involving philosophy of science, science studies, linguistics, rhetoric, and argumentation. 3) We analyze the use of uncertainty frames in a sample of 177 abstracts from the Water Resources Research journal in 2015. This helped develop and tentatively verify the typology, and provides a snapshot of current practice. 4) Provocative recommendations promote adjustments for a more influential, dynamic science. Current practice in uncertainty framing might be described as carefully-considered incremental science. In addition to uncertainty quantification and degree of belief (present in ~5% of abstracts), uncertainty is addressed by a combination of limiting scope, deferring to further work (~25%) and indicating evidence is sufficient (~40%) – or uncertainty is completely ignored (~8%). There is a need for public debate within our discipline to decide in what context different uncertainty frames are appropriate. Uncertainty framing cannot remain a hidden practice evaluated only by lone reviewers

An Economic Analysis of Intermediate-Sized Sunflower Processing Plants

Agribusiness,

Cost Analysis of Potential North Dakota Subterminal Systems

The purpose of this study was to analyze the cost structures associated with subterminal facilities. An economic-engineering approach was used to determine the construction and operation costs of four different sizes of subterminal facilities operating at three different plant capacities. Profitability of subterminals was determined mainly by the volume of grain handled. If a subterminal marketed enough grain, it was able to incur both decreasing average fixed and average variable costs. The larger subterminals were found to be more profitable than the smaller facilities indicating the existence of economies of size in both the fixed and variable cost components. Profitability can be dramatically increased given the availability of internal financing for the construction cost and nondepreciable fixed costs. Upper Great Plains Transportation Institute Report No.44Marketing, Agribusiness,