Hydration of the Bisulfate Ion: Atmospheric Implications

Using molecular dynamics configurational sampling combined with ab initio energy calculations, we determined the low energy isomers of the bisulfate hydrates. We calculated the CCSD(T) complete basis set (CBS) binding electronic and Gibbs free energies for 53 low energy isomers of HSO4–(H2O)n=1–6 and derived the thermodynamics of adding waters sequentially to the bisulfate ion and its hydrates. Comparing the HSO4–/H2O system to the neutral H2SO4/H2O cluster, water binds more strongly to the anion than it does to the neutral molecules. The difference in the binding thermodynamics of HSO4–/H2O and H2SO4/H2O systems decreases with increasing number of waters. The thermodynamics for the formation of HSO4–(H2O)n=1–5 is favorable at 298.15 K, and that of HSO4–(H2O)n=1–6 is favorable for T < 273.15 K. The HSO4– ion is almost always hydrated at temperatures and relative humidity values encountered in the troposphere. Because the bisulfate ion binds more strongly to sulfuric acid than it does to water, it is expected to play a role in ion-induced nucleation by forming a strong complex with sulfuric acid and water, thus facilitating the formation of a critical nucleus.

Implicit Memory for Music in Alzheimer's Disease

Short, unfamiliar melodies were presented to young and older adults and to Alzheimer's disease (AD) patients in an implicit and an explicit memory task. The explicit task was yes–no recognition, and the implicit task was pleasantness ratings, in which memory was shown by higher ratings for old versus new melodies (the mere exposure effect). Young adults showed retention of the melodies in both tasks. Older adults showed little explicit memory but did show the mere exposure effect. The AD patients showed neither. The authors considered and rejected several artifactual reasons for this null effect in the context of the many studies that have shown implicit memory among AD patients. As the previous studies have almost always used the visual modality for presentation, they speculate that auditory presentation, especially of nonverbal material, may be compromised in AD because of neural degeneration in auditory areas in the temporal lobes.

Everything You Have Always Wanted to Know About Academic Advising (Well, Almost...)

Answering the question “what occurs in an academic advising interaction” is not as easy as one might think. Many factors contribute to the academic advising process, and no two advising interactions are the same. This article discusses the different factors involved in an academic advising interaction, emphasizing the need for psychological counselors to become familiar with the specific aspects of the advising processes that occur at their respective institutions.