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Full-Text Articles in Physical Sciences and Mathematics
Preliminary Archaeological Investigations At The Sierra Diablo Cave Site: Paleoindian And Archaic Occupations In Hudspeth County, Texas, Jose Javier Vasquez
Preliminary Archaeological Investigations At The Sierra Diablo Cave Site: Paleoindian And Archaic Occupations In Hudspeth County, Texas, Jose Javier Vasquez
Open Access Theses & Dissertations
It is generally rare to find archaeological sites in the Southwest that retain the type of contextual integrity that the Sierra Diablo Cave exhibits. Often times, cave sites such as the one currently studied offer excellent preservation of cultural materials due to the general lack of moisture and isolation from wind and water erosion. The research aimed to determine when the site was occupied as well as the types of activities that were occurring during those occupations. It exhibits an extensive stratigraphic sequence that contains a well pronounced Late Archaic Period assemblage (Strata A and B) and a Late Pleistocene/Early …
Spectroscopic Study Of The Inhibition Of Calcium Oxalate Calculi By Larrea Tridentata, Luis Alonso Pinales
Spectroscopic Study Of The Inhibition Of Calcium Oxalate Calculi By Larrea Tridentata, Luis Alonso Pinales
Open Access Theses & Dissertations
The causes of urolithiasis include such influences as diet, metabolic disorders, and genetic factors which have been documented as sources that aggravate urinary calculi depositions and aggregations, and, implicitly, as causes of urolithiasis. This study endeavors to detail the scientific mechanisms involved in calcium oxalate calculi formation, and, more importantly, their inhibition under growth conditions imposed by the traditional medicinal approach using the herbal extract, Larrea tridentata. The calculi were synthesized without and with Larrea tridentata infusion by employing the single diffusion gel technique. A visible decrease in calcium oxalate crystal growth with increasing amounts of Larrea tridentata herbal infusion …
Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete
Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete
Open Access Theses & Dissertations
Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data that constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study we utilized Cu isotopes (65Cu) as a tool to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species as well as with bacterial consortia from several natural environments. Adsorption experiments were conducted with live or dead cells over the pH range 2.5 to 6. Surface adsorption of Cu …