Computational Geometry Column 42

A compendium of thirty previously published open problems in computational geometry is presented.Comment: 7 pages; 72 reference

Trade, Knowledge, and the Industrial Revolution

Technological change was unskilled-labor-biased during the early Industrial Revolution of the late eighteenth and early nineteenth centuries, but is skill-biased today. This fact is not embedded in extant unified growth models. We develop a model of the transition to sustained economic growth which can endogenously account for both these facts, by allowing the factor bias of technological innovations to reflect the profit-maximising decisions of innovators. Endowments dictated that the initial stages of the Industrial Revolution be unskilled-labor biased. The transition to skill-biased technological change was due to a growth in "Baconian knowledge" and international trade. Simulations show that the model does a good job of tracking reality, at least until the mass education reforms of the late nineteenth century.

Trade, Knowledge, and the Industrial Revolution

Technological change was unskilled-labor-biased during the early Industrial Revolution of the late eighteenth and early nineteenth centuries, but is skill-biased today. This fact is not embedded in extant unified growth models. We develop a model of the transition to sustained economic growth which can endogenously account for both these facts, by allowing the factor bias of technological innovations to reflect the profitmaximising decisions of innovators. Endowments dictated that the initial stages of the Industrial Revolution be unskilled-labor biased. The transition to skill-biased technological change was due to a growth in “Baconian knowledge” and international trade. Simulations show that the model does a good job of tracking reality, at least until the mass education reforms of the late nineteenth century.Endogenous growth, Demography, Trade

Luddites and the Demographic Transition

Technological change was unskilled-labor-biased during the early Industrial Revolution, but is skill-biased today. This is not embedded in extant unified growth models. We develop a model which can endogenously account for these facts, where factor bias reflects profit-maximizing decisions by innovators. Endowments dictate that the early Industrial Revolution be unskilled-labor-biased. Increasing basic knowledge causes a growth takeoff, an income-led demand for fewer educated children, and the transition to skill-biased technological change. The simulated model tracks British industrialization in the 18th and 19th centuries and generates a demographic transition without relying on either rising skill premia or exogenous educational supply shocks.

Readiness for competitive positioning: A managerial checklist

Competitive positioning is improved by following best practices regarding analysis of competition, consumers, industry dynamics, SBU capabilities, market deliverables and fit, and profit potential of various positions. Only then can positions be identified that are relevant, worthwhile, achievable and defendable. Literature acknowledges the process requirements but few management tools are available to aid in this task. This paper proposes a readiness checklist that helps insure best practices are followed and is a precursor to development of a positioning readiness scale. In addition, a structural equation model is proposed to assess the overall and component-based effects of using the elements in the checklist on achieving strong market positions

From Great Depression to Great Credit Crisis: Similarities, Differences and Lessons

The Great Depression of the Thirties and the Great Credit Crisis of the "Noughties had similar causes but elicited strikingly different policy responses. It may still be too early to assess the effectiveness of current policy responses, but it is possible to analyze monetary and fiscal policies in the 1930s as a "natural experiment" or "counterfactual" capable of shedding light on the impact of recent policies. We employ vector autoregressions, instrumental variables, and qualitative evidence for a panel of 27 countries in the period 1925-1939. The results suggest that monetary and fiscal stimulus was effective – that where it did not make a difference it was not tried. The results also shed light on the debate over fiscal multipliers in episodes of financial crisis. They are consistent with multipliers at the higher end of those estimated in the recent literature, consistent with the idea that the impact of fiscal stimulus will be greater when banking system are dysfunctional and monetary policy is constrained by the zero bound.

Locked and Unlocked Polygonal Chains in 3D

In this paper, we study movements of simple polygonal chains in 3D. We say that an open, simple polygonal chain can be straightened if it can be continuously reconfigured to a straight sequence of segments in such a manner that both the length of each link and the simplicity of the chain are maintained throughout the movement. The analogous concept for closed chains is convexification: reconfiguration to a planar convex polygon. Chains that cannot be straightened or convexified are called locked. While there are open chains in 3D that are locked, we show that if an open chain has a simple orthogonal projection onto some plane, it can be straightened. For closed chains, we show that there are unknotted but locked closed chains, and we provide an algorithm for convexifying a planar simple polygon in 3D with a polynomial number of moves.Comment: To appear in Proc. 10th ACM-SIAM Sympos. Discrete Algorithms, Jan. 199

Embryonic and mature astrocytes exert different effects on neuronal growth in rat ventral mesencephalic slice cultures.

One obstacle with grafting of dopamine neurons in Parkinson's disease is the insufficient ability of the transplant to reinnervate the host striatum. Another issue is the prospective interaction between the donor fetal tissue and the adult astrocytes of the host. To study nerve fiber growth and its interaction with immature/mature astrocytes, ventral mesencephalic (VM) organotypic rat tissue cultures from embryonic days (E) 12, E14, and E18 were studied up to 35 days in vitro (DIV), and co-cultures of E14 VM tissue and mature green fluorescent protein (GFP)-positive astrocytes were performed. Generally, nerve fibers grew from the tissue slice either in association with a monolayer of migrated astroglia surrounding the tissue (glial-associated), or distal to the astroglia as non-glial-associated outgrowth. The tyrosine hydroxylase (TH)-positive glial-associated nerve fiber outgrowth reached a plateau at 21 DIV in E12 and E14 cultures. In E18 cultures, TH-positive neurons displayed short processes and migrated onto the astrocytes. While the non-glial-associated nerve fiber outgrowth dominated the E14 cultures, it was found absent in E18 cultures. The GFP-positive cells in the VM and GFP-positive astrocyte co-cultures were generally located distal to the monolayer of migrated fetal astrocytes, a few GFP-positive cells were however observed within the astrocytic monolayer. In those cases TH-positive neurons migrated towards the GFP-positive cells. Both the non-glial- and glial-associated nerve fibers grew onto the GFP-positive cells. Taken together, the glial-associated growth has limited outgrowth compared to the non-glial-associated nerve fibers, while none of the outgrowth types were hampered by the mature astrocytes

Are we all on course? A curriculum mapping comparison of three australian university open-access enabling programs.

© 2019, Adult Learning Australia Inc. All rights reserved. The curricula in higher education not only provides guidance and direction for students, but aligns with industry standards to safeguard quality offerings in specific programs. While there has been increasing focus on the importance of the curriculum particularly for first year university students, very little is known about the curriculum and design principles that exist in open-access enabling programs in Australia. In the following paper, a comprehensive examination of the curriculum of three large open-access enabling programs is presented. The research team explored the curriculum design via a rigorous mapping exercise to establish potential principles to guide enabling curriculum design. In developing the curriculum-mapping tool for this research project, it became apparent that limited attention has been given to enabling curriculum design in the academic literature. Given increasing attention towards Australian enabling education, the findings of this study emphasise the importance of clarity between the intended and the enacted curriculum, such as in unit learning outcomes and program attributes