Structural and Electronic Decoupling of C_(60) from Epitaxial Graphene on SiC

We have investigated the initial stages of growth and the electronic structure of C_(60) molecules on graphene grown epitaxially on SiC(0001) at the single-molecule level using cryogenic ultrahigh vacuum scanning tunneling microscopy and spectroscopy. We observe that the first layer of C_(60) molecules self-assembles into a well-ordered, close-packed arrangement on graphene upon molecular deposition at room temperature while exhibiting a subtle C_(60) superlattice. We measure a highest occupied molecular orbital–lowest unoccupied molecular orbital gap of ~ 3.5 eV for the C_(60) molecules on graphene in submonolayer regime, indicating a significantly smaller amount of charge transfer from the graphene to C_(60) and substrate-induced screening as compared to C_(60) adsorbed on metallic substrates. Our results have important implications for the use of graphene for future device applications that require electronic decoupling between functional molecular adsorbates and substrates

Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood Malignancy: A Population-Based Cohort Study in Ontario

In a record-linkage study, Joel Ray and colleagues examine the association between diagnostic imaging during pregnancy and later childhood cancers

Economic Ideas and Institutional Change: Evidence from Soviet Economic Discourse 1987-1991

In recent years, institutional and evolutionary economists have become increasingly aware that ideas play an important role in economic development. In the current literature, the problem is usually elaborated upon in purely theoretical terms. In the present paper it is argued that ideas are always also shaped by historical and cultural factors. Due to this historical and cultural specificity theoretical research must be supplemented by historical case studies. The paper analyses the shift in ideas that took place in Soviet economic thought between 1987 and 1991. This case study, it is argued, may contribute to our understanding of the links between ideas and institutions. More specifically, it sheds new light on the issue of whether the evolution of economic ideas is pathdependent, so that they change only incrementally, or whether their development takes place in a discontinuous way that can best be compared with revolutions

Assessing the suitability of mangrove habitats for juvenile Atlantic goliath grouper

While juvenile Atlantic goliath grouper, Epinephelus itajara (Lichtenstein, 1822), are known to depend on mangrove root structure, relationships with water properties (e.g., salinity) and depth remain unclear or understudied. Because availability of suitable mangrove habitat has been suggested as the primary bottleneck to the recovery of this threatened species in the US, we investigated habitat associations of juvenile Atlantic goliath grouper with respect to physical water properties within mangrove habitats. Our study was conducted in six coastal rivers and three canals within the Ten Thousand Islands region of southwest Florida. Results suggested that juvenile Atlantic goliath grouper differed in how they associated with specific mangrove habitats based on season and size. We found that smaller juveniles (3 mg L−1) within mangrove habitat. For small juveniles, extreme temperatures influenced habitat association; for large juveniles, extreme salinity influenced distribution. We also found evidence that juvenile Atlantic goliath grouper associated more with natural rivers over man-made canals. The present study has utility for delineating suitable mangrove habitats for protection and potentially in the design of sampling surveys that aim to estimate population abundance