Patient-level health data from the State of Washington can be purchased for $50. This publicly available dataset has virtually all hospitalizations occurring in the State in a given year, including patient demographics, diagnoses, procedures, attending physician, hospital, a summary of charges, and how the bill was paid. It does not contain patient names or addresses (only ZIPs). Newspaper stor...

This paper extends the work of Glaeser et al. (1992) by looking at effects of agglomeration economies on employment growth in Dutch city-industries and in very small (postal) zip code-industries in the Dutch province of South-Holland. At both levels of geographic detail, findings are broadly consistent with results from the earlier study in that employment growth is enhanced by industrial diver...

Wilson (1987) and others argue that poor neighborhoods lack important organizational resources the middle class takes for granted, such as childcare centers, grocery stores and pharmacies. However, this approach does not distinguish poor neighborhoods from segregated neighborhoods, ignores immigration and neglects city differences. Using Department of Commerce and 2000 Census data for zip codes...

We analyze the phase diagram of a system of spin-1/2 Heisenberg antiferromagnetic chains interacting through a zigzag coupling, also called zigzag ladders. Using bosonization techniques we study how a spin-gap or more generally plateaux in magnetization curves arise in different situations. While for coupled XXZ chains, one has to deal with a recently discovered chiral perturbation, the couplin...

When can t terminal pairs in an m× n grid be connected by t vertex-disjoint paths that cover all vertices of the grid? We prove that this problem is NP-complete. Our hardness result can be compared to two previous NP-hardness proofs: Lynch’s 1975 proof without the “cover all vertices” constraint, and Kotsuma and Takenaga’s 2010 proof when the paths are restricted to have the fewest possible cor...

The chemisorption of pyrimidine and s-triazine, two aromatic molecules with N atoms in the aromatic ring, is studied by first principles calculations to examine not only the chemisorption energy, but also the reaction barriers and the cooperative effects. Among the reaction paths at low coverage, the formation of a cross-bridge structure with two N-Si dative bonds is almost barrierless and shou...

Sensory neurons adopt distinct morphologies and functional modalities to mediate responses to specific stimuli. Transcription factors and their downstream effectors orchestrate this outcome but are incompletely defined. Here, we show that different classes of mechanosensory neurons in C. elegans are distinguished by the combined action of the transcription factors MEC-3, AHR-1, and ZAG-1. Low l...

We give a combinatorial description of the toric ideal invariants Cavender-Farris-Neyman model with molecular clock (CFN-MC) on rooted binary phylogenetic tree and prove results about polytope associated to this ideal. Key polyhedral structure include that number vertices is Fibonacci number, facets can be described using “cluster” underlying tree, volume equal an Euler zig-zag number. The CFN-...