Land Too Good for Indians: Northern Indian Removal

Review of: Land Too Good for Indians: Northern Indian Removal , by John P. Bowes

The Incorporation Of Titanium In Phlogopite In A Simplified, Synthetic System: A Potential Geothermobarometer For Upper Mantle And Lower Crustal Rocks

The solubility of Ti in phlogopite has been experimentally determined in the system K(,2)Mg(,6)Al(,2)Si(,6)O(,20)(OH)(,4)-K(,2)Mg(,4)TiAl(,2)Si(,6)O(,20)(OH)(,4)-K(,2)Mg(,5)TiAl(,4)Si(,4)O(,20)(OH)(,4) from 10 to 30 kbar and from 825 to 1300(DEGREES)C. Starting compositions along the join K(,2)Mg(,6)Al(,2)Si(,6)O(,20)(OH)(,4)-K(,2)Mg(,4.5)TiAl(,3)Si(,5)O(,20)(OH)(,4) were used in order to evaluate the relative importance of the two substitution mechanisms 2Mg = Ti and Mg(2Si)(\u27IV) = Ti(2Al(\u27IV)). These two substitution mechanisms are represented by the joins from the phlogopite molecule (K(,2)Mg(,6)Al(,2)Si(,6)O(,20)(OH)(,4)) to the Ti-OSD (Octahedral Site Deficiency) molecule (K(,2)Mg(,4)TiAl(,2)Si(,6)O(,20)(OH)(,4)) and to the Ti-eastonite molecule (K(,2)Mg(,5)TiAl(,4)O(,20)(OH)(,4)), respectively.;The solubility of Ti in phlogopite increases with increasing temperature and decreases with increasing pressure. For a given starting composition the Ti-OSD/Ti-eastonite and the eastonite/phlogopite ratios in the phlogopite solid solution coexisting with rutile increase with decreasing Ti-content of the phlogopite. The variations in the proportions of the phlogopite and the Ti-OSD end members with variations in temperature and pressure are minor.;The compositions of the experimentally produced phlogopites in terms of the relative proportions of the end member molecules are similar to the compositions of phlogopites from mantle xenoliths, mantle derived, mafic and ultramafic igneous rocks and lower crustal granulites. Based on the experimental data, compositional diagrams including the two Ti-rich phlogopite end members and the sum of the Ti-free end members were contoured for temperature (isobaric diagrams) and pressure (isothermal diagrams). The application of such a phlogopite geothermobarometer to phlogopites from mantle xenoliths and lower crustal granulites gives temperatures and pressures in good agreement with the temperatures and pressures determined by independent geothermometers and geobarometers. The accuracy of the temperature determinations is better than that of the pressure determinations.;Since the geothermobarometer is based on a subsolidus experimental study, it can not be applied to phlogopites that crystallized from a melt. Although further refinements of the phlogopite geothermobarometer are needed, the relationships derived from the simplified experimental system form a basis for determining the physical conditions of phlogopite formation in the upper mantle and the lower crust

Land Too Good for Indians: Northern Indian Removal

Review of: "Land Too Good for Indians: Northern Indian Removal", by John P. Bowes

Inverted repeat-stimulated sister-chromatid exchange events are RAD1-independent but reduced in a msh2 mutant

Inverted repeats (IRs) and trinucleotide repeats (TNRs) that have the potential to form secondary structures in vivo are known to cause genome rearrangements. Expansions of TNRs in humans are associated with several neurological disorders. Both IRs and TNRs stimulate spontaneous unequal sister-chromatid exchange (SCE) in yeast. Secondary structure-associated SCE events occur via double-strand break repair. Here we show that the rate of spontaneous IR-stimulated unequal SCE events in yeast is significantly reduced in strains with mutations in the mismatch repair genes MSH2 or MSH3, but unaffected by a mutation in the nucleotide excision-repair gene RAD1. Non-IR-associated unequal SCE events are increased in both MMR- and rad1-mutant cells; however, SCE events for both IR- and non-IR-containing substrates occur at a higher level in the exo1 background. Our results suggest that spontaneous SCE occurs by a template switching mechanism. Like IRs, TNRs have been shown to generate double-strand breaks (DSBs) in yeast. TNR expansions in mice are MSH2-dependent. Since IR-mediated SCE events are reduced in msh2 cells, we propose that TNR expansion mutations arise when DSBs are repaired using the sister or the homolog as a template

Subsolidus phase relations and perovskite compressibility in the system MgO–AlO_1.5–SiO₂ with implications for Earth's lower mantle

Experimentally determined phase relations in the system MgO-AlO₁․₅-SiO₂ at pressures relevant to the upper part of the lower mantle indicate that Mg-silicate perovskite incorporates aluminum into its structure almost exclusively by a charge-coupled reaction. MgSiO₃-rich bulk compositions along the joins MgSiO₃-MgAlO₂․₅ and MgSiO₃-MgAl₂O₄ crystallize assemblages of perovskite coexisting with periclase. MgO-saturated perovskites along these joins have ambient unit cell volumes consistent with those measured and calculated for aluminous perovskite along the charge-coupled substitution join, MgSiO₃-AlO₁․₅. The compressibility of aluminous perovskite along the MgO-saturated joins is not anomalously low as predicted for oxygen-defect perovskites. The bulk moduli, however, are consistent with previous measurements made for aluminous perovskites along the charge-coupled substitution join. These results agree with first-principles calculations showing very limited stability of O-defects in Mg-perovskite at pressures and temperatures corresponding to lower mantle conditions, but are inconsistent with earlier experimental results showing unusually compressive aluminous perovskite. The maximum solubility of alumina in perovskite is ∼25 mol% along the MgSiO₃-AlO₁․₅ join within the ternary MAS-system (i.e. pyrope composition), and the join is apparently binary. Although primitive mantle peridotite compositions are MgO-saturated and fall nearly on the oxygen vacancy join, alumina substitution into perovskite is expected to occur primarily by charge-coupled substitution throughout the lower mantle. The compressibility of aluminous perovskite in primitive mantle is expected to be only a few percent lower than for end member MgSiO₃ perovskite.13 page(s

Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'

The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved

Nutrition and Attendance for Primary School Students in Ethiopia and Zambia

Introduction: Nutrition impacts attendance for primary school students in Southern Ethiopia and Zambia. Food insecurity causes school-age children to be undernourished, malnourished, and stunted. These health concerns greatly impact ability to attend and perform in school. Methods: Between May and June of 2019 6th and 7th grade students were surveyed within 4 schools in Ethiopia and 5 schools in Zambia. Anthropometric data, health history, and nutritional habits were surveyed. Results: 8% of Ethiopian students were stunted while 10% of Zambian students were stunted. Ethiopian students indicated school lunch was an incentive while Zambian students did not. Most Ethiopian students ate before school while Zambian students did not. Overall, undernutrition of Zambian students implies greater struggle academically. Conclusion: Continued research on the impacts of poor nutrition for students must be conducted. School-age children are not often the center of food insecurity research and are included as a statistic rather than a source of information

Contested place : the Menominee Warriors Society, native and non-native placemaking, and identity construction in rural Wisconsin, 1975

i, 121 leaves : ill. ; 29 cm