I used a Hierarchical approach to study historical biogeography in a group of colubrid snakes found in western North America. I combined small regions of mtDNA sequence data from a large number of individuals, with complete mt-genomic data. First, I investigated the relationships among leptodeirines-a presumed subgroup of dipsadines includeng nightsnakes (Pseudoleptodeira, Eridiphas, and Hypsiglena) - using ~1.5 Kb of data (cob and nad4). The relationships differed among parsimony, likelihood, and bayesian analyses. All analyses supported the monophyly of the nightsnakes; however, none supported the monophyly of the leptodeirines. Instead, these data supported a new hypothesis that the dipsadines were ancestrally rear-fanged and preyed on small vertabrates (frogs and lizards), such as the nightsnakes, while the more derived lineages have modified anterior maxillary dentition and prey strictly on invertabrates. Secondly, using an evolutionary species concept, I test species-subspecies boundaries in the wide-ranging hypsiglena, which has over 17 forms described, by collecting ~800 bp of sequence data (nad4 and tRNA) from ~ 175 individuals. Six major clades, concordant with geography, were recognized as species: Chihuahuan Destert (H. jani); central-western Mexico (H. torquata); upland Jalisco (H. Affinis); central California-Cape of Baja ("Coast," H. ochrorhyncha); Sonoran, Mojave, and Great Basin deserts ("Desert" H. chlorophaea), and an undescribed form from the Sonoran-Chihuahuan desert transition zone ("cochise"). The relationships among the major clades were not well resolved. Lastly, I collected complete mt-genome sequence data from 15 individuals including Eridiphas, Pseudoleptodeira, each of the major clades of Hypsiglena, and Sibon and Imantodes. All combined genomic-level analyses contained overwhelming support for a single phylogeny. These data, in conjunction with the phylogeographic data, supported my hypothesis that vicariance associated with the Miocene seperation of the Cape of Baja from mainland Mexico formed the Baja endemic Eridiphas, followed by subsequent range expansion and dispersal of Hypsiglena onto the northern portion of the peninsula and an even later vicariance event associated with the northern inundation of the gulf of California during the Pliocene. Hysiglena later dispersed down the Baja California Peninsula, coming into secondary contact with Eridiphas, forming a ring-like distribution around the Gulf of California.

The demand for biofuels continues to increase due in part to government standards and promotion as well as the ambitious goals set by various companies and industries. Camelina is considered to be an ideal energy crop because of its low input requirements, suitability for marginal soils, and naturally competitiveness with weeds. A partial equilibrium model with a break-even price approach is used to estimate the potential supply curves for Camelina in Idaho, Montana, Oregon, and Washington. The supply curves are used to determine if the 50 million gallon goal set by the "Farm to Fly" initiative can be met. Given the current price of Camelina, $0.15/lb, the estimated supply of Camelina in all 4 states is 1,756,076,887 lbs and 1,493,684 acres. This estimation assumes that if the wheat-Camelina rotation is more profitable than the current crop rotation, then all of the acres will be converted to a wheat-Camelina rotation. When a 5% adoption rate is applied to the low and the intermediate rainfall zones and a 1% to the high rainfall zones, the number of acres converted to Camelina decreases to 72,213. These results suggest that given current market conditions, the supply of Camelina in the Northwest is not enough to meet the biofuel goal without an increase in yield and government promotion. / Graduation date: 2013

This multiple case study explores issues of equity in science education through an examination of how teachers' reasoning patterns compare with students' reasoning patterns during inquiry-based lessons. It also examines the ways in which teachers utilize students' cultural and linguistic resources, or funds of knowledge, during inquiry-based lessons and the ways in which students utilize their funds of knowledge, during inquiry-based lessons. Three middle school teachers and a total of 57 middle school students participated in this study. The data collection involved classroom observations and multiple interviews with each of the teachers individually and with small groups of students. The findings indicate that the students are capable of far more complex reasoning than what was elicited by the lessons observed or what was modeled and expected by the teachers, but that during the inquiry-based lessons they conformed to the more simplistic reasoning patterns they perceived as the expected norm of classroom dialogue. The findings also indicate that the students possess funds of knowledge that are relevant to science topics, but very seldom use these funds in the context of their inquiry-based lessons. In addition, the teachers in this study very seldom worked to elicit students' use of their funds in these contexts. The few attempts they did make involved the use of analogies, examples, or questions. The findings from this study have implications for both teachers and teacher educators in that they highlight similarities and differences in reasoning that can help teachers establish instructional congruence and facilitate more equitable science instruction. They also provide insight into how students' cultural and linguistic resources are utilized during inquiry-based science lessons. / Graduation date: 2013

Thesis (Ph. D.)--University of Minnesota, 1924. / Published also as: The Twin Cities as a metropolitan market. Minneapolis : University of Minnesota, 1925. (Research publications of the University of Minnesota. Studies in the social sciences ; no. 18). Includes bibliographical references (p. [207]-220) and index.

Thesis (Ph. D.)--University of Minnesota, 1924. / Published also as: The Twin Cities as a metropolitan market. Minneapolis : University of Minnesota, 1925. (Research publications of the University of Minnesota. Studies in the social sciences ; no. 18). Includes bibliographical references (p. [207]-220) and index.

This thesis reconstructs the landscape evolution of the Billy Big Spring site (24GL304, Glacier County, north-central Montana) from the last glacial maximum to present through the analysis of sediment and soil samples collected from a transect of auger tests that bisected the site and surrounding landforms. Interpretations were drawn from stratigraphy, pedologic data, sedimentologic analysis and radiocarbon dating. The site landscape came into being in the late-Pleistocene, after Wisconsin-age glaciers retreated. Glacial retreat left a meltdown depression on the land that filled with water to form a pond, which persisted through the early-Holocene. The onset of the mid-Holocene (Altithermal) occurred before ~8,415 cal. yrs. BP, when increasingly arid conditions caused the water level to drop. The first radiocarbon dated human occupation of this site occurred during the Altithermal, ~7,030 cal. yrs. BP, after the eruption of Mount Mazama (~7,633 cal. yrs. BP). Arid conditions continued until ~7,000 cal. yrs. BP, when pond water re-expanded across the basin, marking the transition to the cooler late-Holocene. Sometime before 2,100 cal. yrs. BP, dry conditions returned, and the extent of the pond water decreased again. Since this time, overland alluvial processes have deposited sediments in the basin. Many hypotheses on how the Altithermal impacted the people of the Northwestern Plains have been proposed since the 1950s, but little agreement has been reached. This is due to the fact that there was great variation in how the Altithermal expressed itself throughout the Northwestern Plains. The human reactions to this phenomena cannot be explained simplistically for the region as a whole. This study shows that the Billy Big Spring site experienced drying during the Altithermal, but despite this, people continued to occupy this site. This evidence adds to the argument that the Altithermal climate of the Northwestern Plains did not have severe enough impacts to impose much hardship on its occupants.

The Peña del Seo tungsten deposit in northwestern Spain is situated in the tin (Sn)-tungsten (W) metallogenic province of Europe − one of the richest tin-tungsten (tantalum-lithium) mineral provinces in the world. The European Union’s current goal is to become self-sufficient of these commodities in the near future and the iTARG3T project was launched in order to improve the understanding and provide innovative exploration methods of these types of deposits. This master thesis will contribute to the iTARG3T project. The aim was to determine which physico-chemical conditions (temperature, pressure, salinity) that prevailed during the emplacement of the Peña del Seo deposit. A geochemical study was done consisting of a fluid inclusion study on the quartz veins from the deposit, and a whole-rock geochemistry analyse of the granitic rock. Homogenisation temperatures ranged between 97,6° C to 325,6° C and salinities (NaCl % equiv.) between 0,2% to 21,3%. The fluid was determined to consist of a two-component system of H2O and NaCl based on eutectic temperature. Based on its geochemical classification the granitic rock was considered to be an alkali granite, strongly peraluminous with S-type characteristics. At least two different types of fluids were present during the emplacement of the Peña del Seo deposit, one that was hot and with a moderate salinity, and one that had a lower temperature than the other fluid and a lower salinity, possibly meteoric water. The depositional mechanism of tungsten is thought to be caused by a combination between mixing between two fluids and cooling of the fluids, with the main depositional mechanism being cooling since the change in salinity was not of such magnitude that it would change the fluid chemical composition, while the decrease in temperature was. It is uncertain whether the granitic rock found at Peña del Seo is part of the granitic cupola of the greisen system. The granitic rock has similar characteristics as the leucogranites of the West Asturian-Leonese Zone and based on quartz vein morphology, which cut the D2 foliation, time of emplacement of the deposit could be linked to the syntectonic event at 320-310 Ma. If the relation between the granitic rock and the greisen system can be determined the time of emplacement would be possible.

The Ordos basin rests upon the North China Block and is one of the largest sedimentary basins in north China, with more than 15 km of Phanerozoic strata. Published estimates suggest that over 2000 m of carbonates and lesser amounts of siliciclastics were deposited on the North China Carbonate Platform (NCCP) from the Lower Can1brian through the Middle Ordovician. However, lower Paleozoic facies successions and deposystems of northwestern Ordos basin remain poorly represented in western literature. This paper constrains depositional environments, lithologies, facies relationships and sea-level history of the northwestern part of the North China block (NCB) in an effort to further document the Early Paleozoic geologic history of western Ordos basin. New stratigraphic data come largely from measured sections in the Zhuozi Shan and Helan Shan in northwest Ordos basin. Strata in the mountains of northwestern Ordos are divided into eleven lithofacies assemblages, distinguished by lithology, stacking patterns and sedimentary structures. Lithofacies assemblages in northwest Ordos are grouped into four lithostratigraphic units that make up the composite type section. Unit A is dominantly composed of shale and mudrock lithofacies, Unit B is dominantly composed of thin-bedded lime mudstone and banded and bioturbated lime mudstone to wackestone, Unit C is dominantly composed of quartz sandstone and dolostone and Unit D is dominantly composed of fossiliferous packstone. These four units were observed in all lower Paleozoic sections of the Helan Shan and Zhuozi Shan. Deposition of Middle Cambrian through lowermost Lower Ordovician strata in northwest Ordos basin occurred on a storm-influenced, mixed siliciclastic and carbonate, shallow-water ramp. Lateral trends in quartz sandstone, paleokarsts, thrombolites and section thickness suggest that accommodation space increased to the south. The depositional architecture changed in the Middle Ordovician to a carbonate shelf environment. The sea-level history of northwestern Ordos shows transgression through the Late Can1brian, regression in the Early Ordovician, followed by a Middle Ordovician transgression, corresponding with North American sea level signatures. Lower Paleozoic sections in northwestern Ordos basin are broadly similar to those previously described in western literature. However, based upon stratigraphic data, shoreline trends of the NCCP model are proved inapplicable to northwestern Ordos. There is no evidence for lower Paleozoic tectonics such as aulacogen-controlled subsidence and platform tilting as described by previous workers. The sea-level history interpreted for northwest Ordos basin is more similar to North American curves than to the North China Carbonate Platform model, suggesting a eustatic control on lithofacies stacking patterns in northwest Ordos basin.

No description available.

The capabilities of a number of remote-sensing techniques for biophysical mapping in the subarctic have been examined at Pen Island in northwestern Ontario. After a two week field reconnaissance, colour infrared aerial photography was studied and a detailed biophysical map of the area was produced. Using this knowledge LANDSAT satellite data of the site were investigated. In a visual analysis of the data, the majority of the units identified in the airphoto interpretation were detected, and these were distinguished primarily by their spectral characteristics. Digital analysis of the satellite data using the Bendix MAD system allowed many of the classes of the earlier studies to be delineated and also permitted the classification to be readily extended beyond the original site. In both LANDSAT analyses specific biophysical units could be mapped from the satellite data but could not be identified without the airphoto interpretation. / Thesis / Master of Science (MSc)