Intramolecular hydrogen bonding motifs in deprotonated glycine peptides by cryogenic ion infrared spectroscopy.

The infrared spectra of deprotonated glycine peptides, (Gn-H)(-) with n = 1-4, in the 1200-3500 cm(-1) spectral region are presented. Comparisons between the experimental and calculated spectra reveal the chain length dependent hydrogen bonding motifs that define the geometries of these species. First, an interaction between the terminal carboxylate and the neighboring amide N-H is present in all the peptide structures. This interaction is strong enough to align this amide group in the same plane as the carboxylate. However, we found that the vibrational frequency shift of this hydrogen bonded N-H group is not well reproduced in the calculations. Second, in the longer (G3-H)(-) and (G4-H)(-) species, the peptide chain folds such that the terminal NH2 group also interacts with the carboxylate. Both of these folded structures display an interaction between the terminal NH2 and the neighboring N-H as well. Lastly, an amide-amide interaction is observed in the longest (G4-H)(-) structure. Analysis of the N-H peak positions reveals the interplay among the different hydrogen bonds, especially around the negatively charged carboxylate moiety.

Optimism and challenge for science-based conservation of migratory species in and out of U.S. National Parks.

Public agencies sometimes seek outside guidance when capacity to achieve their mission is limited. Through a cooperative agreement and collaborations with the U.S. National Park Service (NPS), we developed recommendations for a conservation program for migratory species. Although NPS manages ∼ 36 million hectares of land and water in 401 units, there is no centralized program to conserve wild animals reliant on NPS units that also migrate hundreds to thousands of kilometers beyond parks. Migrations are imperiled by habitat destruction, unsustainable harvest, climate change, and other impediments. A successful program to counter these challenges requires public support, national and international outreach, and flourishing migrant populations. We recommended two initial steps. First, in the short term, launch or build on a suite of projects for high-profile migratory species that can serve as proof to demonstrate the centrality of NPS units to conservation at different scales. Second, over the longer term, build new capacity to conserve migratory species. Capacity building will entail increasing the limited knowledge among park staff about how and where species or populations migrate, conditions that enable migration, and identifying species' needs and resolving them both within and beyond parks. Building capacity will also require ensuring that park superintendents and staff at all levels support conservation beyond statutory borders. Until additional diverse stakeholders and a broader American public realize what can be lost and do more to protect it and engage more with land management agencies to implement actions that facilitate conservation, long distance migrations are increasingly likely to become phenomena of the past.