Design and Testing of an Ecological Invert Culvert

Consideration of stream ecology and stream biology is an emerging trend in the effective design of culverts. Current methods of burying the inverts of culvert have been shown to provide limited or no benefits. To address limitations in existing technologies and current design practices, Colorado State University has developed a culvert invert technology that retains streambed material and provides stream ecology benefits. In this session we will review the development and testing process from Colorado State University

Lifelong Multi-Agent Path Finding in Large-Scale Warehouses

Multi-Agent Path Finding (MAPF) is the problem of moving a team of agents to their goal locations without collisions. In this paper, we study the lifelong variant of MAPF, where agents are constantly engaged with new goal locations, such as in large-scale automated warehouses. We propose a new framework Rolling-Horizon Collision Resolution (RHCR) for solving lifelong MAPF by decomposing the problem into a sequence of Windowed MAPF instances, where a Windowed MAPF solver resolves collisions among the paths of the agents only within a bounded time horizon and ignores collisions beyond it. RHCR is particularly well suited to generating pliable plans that adapt to continually arriving new goal locations. We empirically evaluate RHCR with a variety of MAPF solvers and show that it can produce high-quality solutions for up to 1,000 agents (= 38.9\% of the empty cells on the map) for simulated warehouse instances, significantly outperforming existing work.Comment: Published at AAAI 202

While the rescue of Fannie Mae and Freddie Mac was generally successful, there is still no end in sight to their conservatorship

Seven years ago the US government dramatically rescued the government-sponsored enterprises Fannie Mae and Freddie Mac, placing them into conservatorship, a situation that remains ongoing. In new research, W. Scott Frame, Andreas Fuster, Joseph Tracy, and James Vickery, assess the success of the rescue using five criteria. They find that while the agencies were able to support mortgage supply through the crisis and afterwards, the rescue was less successful in supporting the government’s macroeconomic objectives. While there is broad agreement that Fannie Mae and Freddie Mac should be replaced by a private system, there is no end to their conservatorships in sight

Liver Transplantation to Provide Low-Density-Lipoprotein Receptors and Lower Plasma Cholesterol in a Child with Homozygous Familial Hypercholesterolemia

A six-year-old girl with severe hypercholesterolemia and atherosclerosis had two defective genes at the low-density-lipoprotein (LDL) receptor locus, as determined by biochemical studies of cultured fibroblasts. One gene, inherited from the mother, produced no LDL receptors; the other gene, inherited from the father, produced a receptor precursor that was not transported to the cell surface and was unable to bind LDL. The patient degraded intravenously administered 125I-LDL at an extremely low rate, indicating that her high plasma LDL-cholesterol level was caused by defective receptor-mediated removal of LDL from plasma. After transplantation of a liver and a heart from a normal donor, the patient's plasma LDL-cholesterol level declined by 81 per cent, from 988 to 184 mg per deciliter. The fractional catabolic rate for intravenously administered 125I-LDL, a measure of functional LDL receptors in vivo, increased by 2.5-fold. Thus, the transplanted liver, with its normal complement of LDL receptors, was able to remove LDL cholesterol from plasma at a nearly normal rate. We conclude that a genetically determined deficiency of LDL receptors can be largely reversed by liver transplantation. These data underscore the importance of hepatic LDL receptors in controlling the plasma level of LDL cholesterol in human beings. (N Engl J Med 1984; 311: 1658–64.). © 1984, Massachusetts Medical Society. All rights reserved

Open access to economic outcome data will help to bridge the gap between clinical trials and clinical guidelines

Buoyed by a burgeoning medical culture of “appropriate use” and rising doctor awareness of the financial ruin that threatens many patients who navigate expensive treatments in pursuit of better health, medical specialist societies have grown increasingly vocal about integrating economic value in their clinical guidelines. These encouraging developments are, however, threatened by a worsening decline in the generalisability of randomised controlled trials, a concern supported by widening differences between the characteristics of patients enrolled in trials and those of the populations targeted for intervention outside trials