Introducing the North American Association of Practicum Sites in Neuropsychology (NAPSN): development of a new organization devoted to facilitating high quality practicum training.

Introduction: In February 2023, a work group began to develop a new North American organization in neuropsychology to represent and support practicum-training sites. While other training-focused organizations such as the Association of Postdoctoral Programs in Clinical Neuropsychology (APPCN) and the Association of Internship Training in Clinical Neuropsychology (AITCN) have existed for many years, no organization exists to promote and support practicum level training outside of doctoral degree programs. The work group developed such an organization, subsequently named the North American Association of Practicum Sites in Neuropsychology (NAPSN), beginning with a mission statement and general purpose of the organization. Methods: The work group divided members into five task forces focused on various tasks needed to start the organization, including Mission/Vision, Administrative Structure, Membership, Financials, and Bylaws. The entire work group met monthly with additional meetings and work via email for the various task forces, which resulted in the development of a mission statement and bylaws, as well as a framework for program administration, membership requirements and financial needs. Conclusions: The group developed NAPSN primarily as a resource to support diverse practicum programs in urban, suburban, and rural areas in the US and Canada to provide optimal graduate level clinical training in neuropsychology. Didactics aimed specifically at practicum students was one need identified early in the process. NAPSN is developing a website-based resource in collaboration with other training organizations to increase the didactic offerings to practicum students. Other initiatives and collaborative efforts will be undertaken over time as circumstances warrant.

The calcium-modulated structures of calmodulin and S100b proteins are useful to monitor hydrogen/deuterium exchange efficiency using matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Hydrogen/deuterium exchange (HDX) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) is a sensitive, salt-tolerant and high-throughput method useful to probe protein conformation and molecular interactions. However, a drawback of the MALDI HDX technique is that sample preparation methods can typically result in higher levels of artificial deuterium in-exchange and/or hydrogen back- exchange just prior to or during mass analysis; this may impair data reproducibility and impede structural and kinetic data interpretation. While methods to minimize effects of back-exchange during protein analyte deposition on MALDI plates have been reported, this study presents a readily available, highly sensitive protein control set to facilitate rapid MALDI HDX protocol workup. The Ca(2+)-induced solvent accessible surface area (ASA) changes of calmodulin (CaM) and S100 proteins were employed to monitor and optimize HDX protocol efficiency. Under non- stringent room temperature conditions, the Ca(2+)-induced deuterium exchange of CaM, DeltaD(ca2+ -apo), MH(+) shifts -17 to -24 Da, while S100 DeltaD(ca2+ -apo) MH(+) shifts +8 to +12 Da. By comparing the divergent CaM and S100 Ca(2+)-induced deuterium mass shift differences, HDX sample workup and MALDI plate spotting conditions can easily be monitored.