The undersigned authors note the following: "We wish to bring to your attention an issue regarding our PNAS publication referenced above. Although we cite our earlier PNAS publication (see ref. Figs. 2 and 3 display the UWHBs for Hb β-subunit (pdb.1bz0, chain B) and human cellular prion protein (pdb.1qm0) (12)(13)(14). Within the natural interactive context of the Hb subunit, the UWHBs signal crucial binding regions (24): UWHBs (90, 94), (90, 95) are associated with the β-FG corner involved in the quaternary α1β2 interface; UWHB (5, 9) is adjacent to Glu-6 which in sickle cell anemia mutates to Val-6 and is located at the Val-6-(Phe-85, Leu-88) interface in the deoxyHbS fiber."The following text in the section titled 'Toward a Structural Diagnosis' on page 6449 of our text is similar to the text beginning in the last paragraph on page 2392 in ref. 23:The distribution of proteins according to their average extent of hydrogen bond wrapping and their spatial concentration of structural defects is shown in Fig. 5 (see also ref. 23). The sample of 2,811 PDB proteins is large enough to define a reliable abundance distribution with an inflection point at ρ = 6.20. The integration of the distribution over a ρ-interval gives the fraction of proteins whose ρ lies within that range. Of the 2,811 proteins examined, 2,572 have ρ > 6.20, and none of them is known to yield amyloid aggregation under physiological conditions entailing partial retention of structure. Strikingly, relatively few disease-related amyloidogenic proteins are known in the sparsely populated, underwrapped 3.5 < ρ < 6.20 range, with the cellular prion proteins located at the extreme of the spectrum (3.53 < ρ < 3.72)....The range of H-bond wrapping 3.5 < ρ < 4.6 of 20 sampled PDB membrane proteins has been included in Fig. 5 for comparison. As expected, such proteins do not have the stringent H-bond packing requirements of soluble proteins for their H bonds at the lipid interface. Thus, this comparison becomes suggestive in terms of elucidating the driving factor for aggregation in soluble proteins: Although the UWHB constitutes a structural defect in a soluble protein because of its vulnerability to water attack, it is not a structural defect in a membrane protein. The exposure of the polar amide and carbonyl of the unbound state to a nonpolar phase is thermodynamically unfavorable (22). The virtually identical ρ value for human prion and outer-membrane protein A (Fig. 5) is revealing in this regard.Furthermore, all known amyloidogenic proteins that occur naturally in complexed form have sufficient H-bond wrapping within their respective complexes (ρ value near 6.2). Their amyloidogenic propensity appears only under conditions in which the protein is dissociated from the complex (compare Fig. 5). This finding is corroborated by the following computation. If an intramolecular hydrogen bond is underwrapped within the isolated protein molecule but located at an interface upon complexation, then to determine its extent of wrapping within the complex, we take ...

Global pinniped distribution is greatly determined by changes in sea surface temperature. El Niño events also have been reported to directly influence pinniped distribution. These events have increased in frequency and intensity changing the foraging ecology of the two pinniped species analyzed. In this paper, we present new extralimital records of distribution of two species rarely found in Mexican waters: the Galapagos (Zalophus wollebaeki) and the Northern (Eumetopias jubatus) sea lions. Three adult Z. wollebaeki were found in Chiapas, and one E. jubatus was recorded off the coasts of Colima-both exceeding the maximum reported extralimital distance. These new records increase the number of marine mammal species recorded in Mexico and add evidence to the fact that large-scale climatic variation and possible effects of global warming shift the distribution of marine mammals.

Wiersma and Nudds (1) make four main points: (i) the area to be covered by the key conservation sites proposed is a negligible percentage of the ocean; (ii) they doubt the representativeness of our biodiversity patterns; (iii) they question the persistence of the species; and (iv) they claim we do not acknowledge the dynamic nature of ecological systems.First, 12% of ocean coverage is not an arbitrary percentage; it derived from the most conservative approach of targeting Marxan to optimize conservation patches that contained at least 10% of all 129 marine mammal geographic ranges (2). We followed the work of Ceballos et al. on terrestrial mammals and also targeted 10% so this work would be comparable to our previous studies (3, 4).Second, our biodiversity patterns coincide with those of Schipper et al. (5) and Kaschner et al. (6) and are based on recent distribution maps. Despite the limitations in present oceanic knowledge, it is imperative to evaluate and implement conservation measures in ways that attempt to compensate for the uncertainties. Terrestrial mammal conservation faces similar uncertainties as those on the ocean, but significant progress has been made in identifying critical conservation sites by using data similar to those in our study. Also, the goal of Marxan is to achieve the highest representation of biodiversity features at the smallest possible cost.Third, we understand marine mammals are constantly changing their distribution patterns. Until adequate estimates become available of changes in several oceanographic variables, persistence cannot be measured in the near future. Models that incorporate distribution patterns and oceanographic variables can give us insight on what will happen with persistence if those variables shift the distribution.Fourth, we clearly state that saving one or two populations will not be enough because of the role such mammals play; additionally, we also set Marxan to select adjacent planning units preferentially. Because of our concern about ecosystem degradation, we analyzed human impacts on the key conservation sites.