Colonial and Revolutionary Muster Rolls: Some New Evidence on Nutrition and Migration in Early America

That investment in human capital has made an important contribution to the increase of labor productivity and per capita income during the last several centuries is widely acknowledged. While much of the research on this issue has focused on education, many scholars have also directed attention to the significance of improvements in nutrition. Until recently, efforts to study this subject have been hampered by a lack of evidence, but it now appears possible to construct indexes of nutrition from height-by-age data. This paper employs a relatively underutilized type of historical document to investigate the level of nutrition in early America. The same material also provides a rich source of information about patterns of migration during this period. This paper finds that native-born Americans approached modern heights by the time of the Revolution. On average, colonial Americans appear to have been 2 to 4 inches taller than Europeans, with southerners considerably taller than northerners and the rural population of greater stature than the urban. These differences may indicate that other factors besides nutrition were important in accounting for the dramatic changes in U.S. mortality rates during the nineteenth century.

Protein signatures using electrostatic molecular surfaces in harmonic space

We developed a novel method based on the Fourier analysis of protein molecular surfaces to speed up the analysis of the vast structural data generated in the post-genomic era. This method computes the power spectrum of surfaces of the molecular electrostatic potential, whose three-dimensional coordinates have been either experimentally or theoretically determined. Thus we achieve a reduction of the initial three-dimensional information on the molecular surface to the one-dimensional information on pairs of points at a fixed scale apart. Consequently, the similarity search in our method is computationally less demanding and significantly faster than shape comparison methods. As proof of principle, we applied our method to a training set of viral proteins that are involved in major diseases such as Hepatitis C, Dengue fever, Yellow fever, Bovine viral diarrhea and West Nile fever. The training set contains proteins of four different protein families, as well as a mammalian representative enzyme. We found that the power spectrum successfully assigns a unique signature to each protein included in our training set, thus providing a direct probe of functional similarity among proteins. The results agree with established biological data from conventional structural biochemistry analyses.Comment: 9 pages, 10 figures Published in PeerJ (2013), https://peerj.com/articles/185

Motion of a droplet for the mass-conserving stochastic Allen-Cahn equation

We study the stochastic mass-conserving Allen-Cahn equation posed on a bounded two-dimensional domain with additive spatially smooth space-time noise. This equation associated with a small positive parameter describes the stochastic motion of a small almost semicircular droplet attached to domain's boundary and moving towards a point of locally maximum curvature. We apply It\^o calculus to derive the stochastic dynamics of the droplet by utilizing the approximately invariant manifold introduced by Alikakos, Chen and Fusco for the deterministic problem. In the stochastic case depending on the scaling, the motion is driven by the change in the curvature of the boundary and the stochastic forcing. Moreover, under the assumption of a sufficiently small noise strength, we establish stochastic stability of a neighborhood of the manifold of droplets in $L^2$ and $H^1$, which means that with overwhelming probability the solution stays close to the manifold for very long time-scales