Acculturation of the Dakota Indians

In this pamphlet the process of acculturation among the Dakota Indians-the change which has taken place in Dakota culture as a result of contact with the dominant Caucasian society-has been analyzed. We may conclude from this study that in general culture change was most likely to occur among the Dakotas when the new culture elements satisfied some basic or secondary drive of the people. Culture change was likewise dependent upon the manner in which the new ideas were introduced to them. If the changes were attempted through coercion, they were not so readily accepted as those made voluntarily. The policies of the traders, missionaries, government agents, and agriculturalists were investigated to determine the extent of enforced and permissive acculturation. Enforced acculturation was usually accompanied by resistance to change. The disruption of family patterns, the loss of the means of subsistence, and the social disorganization of Dakota society were the ·most evident results of the acculturation process

Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects

Spinal Muscular Atrophy (SMA) is caused by diminished function of the Survival of Motor Neuron (SMN) protein, but the molecular pathways critical for SMA pathology remain elusive. We have used genetic approaches in invertebrate models to identify conserved SMN loss of function modifier genes. Drosophila melanogaster and Caenorhabditis elegans each have a single gene encoding a protein orthologous to human SMN; diminished function of these invertebrate genes causes lethality and neuromuscular defects. To find genes that modulate SMN function defects across species, two approaches were used. First, a genome-wide RNAi screen for C. elegans SMN modifier genes was undertaken, yielding four genes. Second, we tested the conservation of modifier gene function across species; genes identified in one invertebrate model were tested for function in the other invertebrate model. Drosophila orthologs of two genes, which were identified originally in C. elegans, modified Drosophila SMN loss of function defects. C. elegans orthologs of twelve genes, which were originally identified in a previous Drosophila screen, modified C. elegans SMN loss of function defects. Bioinformatic analysis of the conserved, cross-species, modifier genes suggests that conserved cellular pathways, specifically endocytosis and mRNA regulation, act as critical genetic modifiers of SMN loss of function defects across species

Spectroscopic studies of the nature of ligand bonding in carbonmonoxyhemoglobins: evidence of a specific function for histidine-E7 from infrared and nuclear magnetic resonance intensities

Infrared spectra of carbon monoxide ligated hemoglobins from human, horse, and rabbit donors have been examined. A single vibrational frequency at 1951 cm^(-1) is observed for CO bound to the heme in horse and human hemoglobins. Studies of the isolated α-CO and β -CO subunits of human hemoglobin reveal that the observation of a single frequency in the intact tetramer is the result of a superposition of the α-CO and β-CO vibrational frequencies. The apparent integrated absorption intensities of these CO vibrations are shown both to have values of 1.0 X 10^5 M^(-1) cm^(-2) within experimental error. For rabbit CO-Hb two vibrational frequencies appear (Caughey, W. S., et al. (1973) Fed. Proc., Fed. Am. Soc. Exp. Biol. 32, 552) and are assigned to CO bound to the β (1951 cm^(-1)) and a (1928 cm^(-1)) subunits within the intact tetramer. The β-CO subunit exhibits both frequency and intensity similarities with horse and human hemoglobins. The rabbit α-CO subunit, however, exhibits a markedly lower frequency and much smaller intensity compared with the other CO-hemoglobins. These data are interpreted in terms of a specific role for the distal histidine (E7) in rabbit a subunits, in which this histidine functions as a nucleophilic donor to coordinated CO

^(13)C nuclear magnetic resonance studies of the binding of isocyanides to various hemoglobins and myoglobins

Interactions between ethyl and isopropyl isocyanides and various hemoglobins and myoglobins have been studied by ^(13)C nuclear magnetic resonance. The results indicate that the chemical shift of the bound isocyanide depends on the structure of the hemoglobin subunit or myoglobin. The resonances exhibited by isocyanides bound to myoglobin are sensitive to pH in contrast to the situation with rabbit and human hemoglobins. β subunits of opossum, rabbit, and human hemoglobins show a significantly greater preferential affinity for CO relative to EIC than do α subunits which have allowed the assignment of resonances. Rabbit, human, and opossum hemoglobin subunits bind ethyl isocyanide without observable preferences and an excess of DPG does not appear to affect this random order of ligation. In contrast, an excess of IHP seems to cause preferential ligation of the α subunits in these hemoglobins. The results have been used to gain insights into the differing characteristics of the ligand binding pockets of these various hemoglobins

Assignment of Hyperfine-Shifted Resonances in Low-Spin Forms of Cytochrome c Peroxidase by Reconstitutions with Deuterated Hemins

Proton magnetic resonance assignments of protons from peripheral heme substituents have been carried out for two low-spin forms of cytochrome c peroxidase: CcP-CN and CcP-N3. The assignments were made by reconstituting CcP with six specifically deuterated protohemin IX derivatives. The results indícate that the pattern of unpaired π spin-density delocalization is consistent with an interpretation whereby the source of the rhombic perturbation is the orientation of the proximal histidine\u27s imidazole plane. However, we also present evidence that a specific interaction between pyrrole II and tryptophan 51 affects the observed shift pattern, thereby contributing to the rhombic perturbation. © 1983, American Chemical Society. All rights reserved