Pseudo-Reimannian metrics with parallel spinor fields and vanishing Ricci tensor

I discuss geometry and normal forms for pseudo-Riemannian metrics with parallel spinor fields in some interesting dimensions. I also discuss the interaction of these conditions for parallel spinor fields with the condition that the Ricci tensor vanish (which, for pseudo-Riemannian manifolds, is not an automatic consequence of the existence of a nontrivial parallel spinor field).

Calibrated embeddings in the special Lagrangian and coassociative cases

Every closed, oriented, real analytic Riemannian 3-manifold can be isometrically embedded as a special Lagrangian submanifold of a Calabi-Yau 3-fold, even as the real locus of an antiholomorphic, isometric involution. Every closed, oriented, real analytic Riemannian 4-manifold whose bundle of self-dual 2-forms is trivial can be isometrically embedded as a coassociative submanifold in a G_2-manifold, even as the fixed locus of an anti-G_2 involution. These results, when coupled with McLean's analysis of the moduli spaces of such calibrated submanifolds, yield a plentiful supply of examples of compact calibrated submanifolds with nontrivial deformation spaces.

Global Value Chain Analysis: A Primer, 2nd Edition

The first edition of Global Value Chain Analysis: A Primer was released five years ago (May 2011) in order to provide an overview of the key concepts and methodological tools used by Duke University’s Center on Globalization, Governance & Competitiveness (Duke CGGC) a university-based research center that focuses on innovative applications of the GVC framework, which was developed by Duke CGGC’s founding director, Gary Gereffi. The Second Edition of Global Value Chain Analysis: A Primer (July 2016) retains a simple, expository style and use of recent research examples in order to offer an entry point for those wishing to better understand and use the GVC framework as a tool to analyze how local actors (firms, communities, workers) are linked to and affected by major transformations in the global economy. The GVC framework focuses on structural shifts in global industries, anchored by the core concepts of governance and upgrading. This Second Edition highlights some of the refinements in these concepts, and introduces a number of new illustrations drawing from recent Duke CGGC research. The bibliography offers a sampling of the broad array of studies available on the Duke CGGC website and in related academic publications. We hope this work stimulates continued interest in and use of the GVC framework as a tool to promote more dynamic, inclusive and sustainable development outcomes for all economies and the local actors within them.

An Economic Analysis of Global Policy Proposals to Prohibit Compensation of Blood Plasma Donors

© 2016 International Journal of the Economics of Business.Human blood plasma and its derivative therapies have been used therapeutically for more than 50 years, after first being widely used to treat injuries during World War II. In certain countries, manufacturers of these therapies – known as plasma-derived medicinal products (PDMPs) – compensate plasma donors, raising healthcare and ethical concerns among some parties. In particular, the World Health Organization has taken a strong advocacy position that compensation for blood donations should be eliminated worldwide. This review evaluates the key economic factors underlying the supply and demand for PDMPs and the evidence pointing to the policy options that are most likely to maintain a reliable supply of life-sustaining therapies. It concludes that compensated plasma donation is important for maintaining adequate and consistent supplies of plasma and limits the risk of under-treatment for the foreseeable future.