Still flat after all these years

The Universe could be spatially flat, positively curved or negatively curved. Each option has been popular at various times, partly affected by an understanding that models tend to evolve away from flatness. The curvature of the Universe is amenable to measurement, through tests such as the determination of the angles of sufficiently large triangles. The angle subtended by the characteristic scale on the Cosmic Microwave sky provides a direct test, which has now been realised through a combination of exquisite results from a number of CMB experiments. After a long and detailed investigation, with many false clues, it seems that the mystery of the curvature of the Universe is now solved. It's an open and shut case: the Universe is flat.Comment: 7 pages, 2 figures, submitted to the Gravity Research Foundation Essay Competition for 200

Predicting the unexpected in stomatal gas exchange: not just an open-and-shut case

Plant membrane transport, like transport across all eukaryotic membranes, is highly non-linear and leads to interactions with characteristics so complex that they defy intuitive understanding. The physiological behaviour of stomatal guard cells is a case in point in which, for example, mutations expected to influence stomatal closing have profound effects on stomatal opening and manipulating transport across the vacuolar membrane affects the plasma membrane. Quantitative mathematical modelling is an essential tool in these circumstances, both to integrate the knowledge of each transport process and to understand the consequences of their manipulation in vivo. Here, we outline the OnGuard modelling environment and its use as a guide to predicting the emergent properties arising from the interactions between non-linear transport processes. We summarise some of the recent insights arising from OnGuard, demonstrate its utility in interpreting stomatal behaviour, and suggest ways in which the OnGuard environment may facilitate ‘reverse-engineering’ of stomata to improve water use efficiency and carbon assimilation

An Open and Shut Case: Epistemic Closure in the Manifest Image

The epistemic closure principle says that knowledge is closed under known entailment. The closure principle is deeply implicated in numerous core debates in contemporary epistemology. Closure’s opponents claim that there are good theoretical reasons to abandon it. Closure’s proponents claim that it is a defining feature of ordinary thought and talk and, thus, abandoning it is radically revisionary. But evidence for these claims about ordinary practice has thus far been anecdotal. In this paper, I report five studies on the status of epistemic closure in ordinary practice. Despite decades of widespread assumptions to the contrary in philosophy, ordinary practice is ambivalent about closure. Ordinary practice does not endorse an unqualified version of the epistemic closure principle, although it might endorse a source-relative version of the principle. In particular, whereas inferential knowledge is not viewed as closed under known entailment, perceptual knowledge might be

The International Review | 2004 Fall

The War on Terror: Balancing National Security and Civil Liberties Outsourcing Backlash? Will Efforts to Keep Jobs at Home Violate the U.S. Constitution and International Law? Alumna Profile: Roberta Baldini ’94, Assistant Trial Attorney, International Criminal Tribune for Rwanda Global trade talks back on track One-sentence curb on human rights abuses Cotton no longer king at the WTO? Open and shut: First WTO case against China International high stakes poker? An exception to an exceptionhttps://digitalcommons.nyls.edu/international_review_newsletter/1017/thumbnail.jp

Co-optimization of power line shutoff and restoration for electric grids under high wildfire ignition risk

Electric power infrastructure has ignited several of the most destructive wildfires in recent history. Preemptive power shut-offs are an effective tool to mitigate the risk of ignitions from power lines, but at the same time can cause widespread power outages. Electric utilities are thus faced with the challenging trade-off of where and when to implement these shut-offs, as well as how to most efficiently restore power once the wildfire risk is reduced. This work proposes a mathematical optimization problem to help utilities make these decisions. Our model co-optimizes the power shut-off (considering both wildfire risk reduction and power outages) as well as the post-event inspection and energization of lines. It is implemented as a rolling horizon optimization problem that is resolved whenever new forecasts of load and wildfire risk become available. We demonstrate our method on the IEEE RTS-GMLC test case using real wildfire risk data US Geological Survey, and investigate the sensitivity of the results to the forecast quality, decision horizon and system restoration budget. The software implementation is available in the open source software package PowerModelsWildfire.jl