Bilinguals often show evidence of cross language influences, such as facilitation in processing cognates. Here we use computational methods for analyzing spontaneous English texts written by hundreds of speakers of different L1s, at different levels of English proficiency, to investigate writers’ preference for using cognates over alternative word choices. We focus on English, since a majority of its lexicon is either of Romance or Germanic origin, allowing an investigation of the preference of speakers of Germanic and Romance L1s towards cognates between their L1 and English. Results show that L2 writers tend to prefer English cognates, and that this tendency is weaker as English proficiency level increases, suggesting diminishing effects of CLI. However, a comparison of the L2 writers with native English writers shows general overuse of cognates only for the Germanic, but not the Romance, L1 speakers, most likely due to the register of argumentative writing.

A new computer program (CORE) is described that predicts core hydrophobic sequences of predetermined target protein structures. A novel scoring function is employed, which for the first time incorporates parameters directly correlated to free energies of unfolding (ΔGu), melting temperatures (Tm), and cooperativity. Metropolis-driven simulated annealing and low-temperature Monte Carlo sampling are used to optimize this score, generating sequences predicted to yield uniquely folded, stable proteins with cooperative unfolding transitions. The hydrophobic core residues of four natural proteins were predicted using CORE with the backbone structure and solvent exposed residues as input. In the two smaller proteins tested (Gβ1, 11 core amino acids; 434 cro, 10 core amino acids), the native sequence was regenerated as well as the sequence of known thermally stable variants that exhibit cooperative denaturation transitions. Previously designed sequences of variants with lower thermal stability and weaker cooperativity were not predicted. In the two larger proteins tested (myoglobin, 32 core amino acids; methionine aminopeptidase, 63 core amino acids), sequences with corresponding side-chain conformations remarkably similar to that of native were predicted.