Beetle diversity and habitat associations of five prevalent riparian plant communities were examined along the lower reaches of Big Beaver Creek Research Natural Area, North Cascades National Park, Washington. These communities were defined by dominant tree species, and included Alder Swamps, Cedar-Hemlock Forests, Douglas-fir Forests, Gravel Bars, and Willow-Sedge Swamps. Monthly samples were taken with pitfall traps from 10 randomly selected patches per habitat during the snow-free periods (mid-June through mid-October) of 1995 and 1996. A total of 8,179 non-necrophagous beetles was collected, comprising 4 families and 290 species. Four families - Staphylinidae (43%), Carabidae (31%), Elateridae (12%), and Anthicidae (6%) accounted for 92% of all individuals. Four families encompassed 65% of all species Staphylinidae (31%), Carabidae (19%), Elateridae (8%), arid Leiodidae (7%) A few species accounted for the majority of individuals. Almost 51% of individuals were found among just 20 species. The five most abundant species in each habitat accounted for 33% (Alder Swamps) to 71% (Gravel Bars) of individuals. Beetle abundance and species composition differed among habitats. Abundance ranged from 1,530 (Cedar-Hemlock Forests) to 2,071 (Alder Swamps) . Abundance per trap per month varied from 16 (Willow-sedge Swamps) to 27 (Alder Swamps). Species richness was lowest in Douglas-fir Forests (76) and highest in Alder Swamps (119) Simpson's 1-D index ranged from 0.74 (Douglas-fir Forests) to 0.96 (Alder Swamps). Species were categorized as detritivores, fungivores, herbivores, omnivores, predators, and unknowns. Individuals and species of predators and fungivores were generally numerically dominant. Herbivores and omnivores contributed few species and individuals. Gravel Bars virtually lacked fungivores and were the only community with many (more than 30%) detrivorous individuals. Two patterns of seasonal abundance were evident. Abundance was highest in June in the two open habitats, Gravel Bars and Willow-Sedge Swamps, thereafter sharply and continuously declining into October. Abundance peaked during September in the forested habitats. Baseline data was acquired about the North Cascades National Park beetle faunas, furthering Park goals to perpetuate habitat and community assemblage integrity. In a larger context, this information has also enriched the understanding of the arthropod faunas of the Pacific Northwest. / Graduation date: 2002

The sheeted complex of the ~92 Ma Tenpeak pluton, in the Northern Washington Cascades crystalline core, forms a <1.5-km wide zone with a moderate, NE-dip at the SW margin of the pluton. Sheeted magmatic complexes, such as the one in the Tenpeak pluton, are common in plutons and represent examples of incremental growth of plutons. Though it is widely accepted that plutons are constructed incrementally over prolonged timescales of several million years, it is not clear if and to what degree individual batches of magma interact, the timing and size of each magma pulse, and the role, timing, and location of magmatic differentiation. This project uses a combination of field evidence, bulk rock chemistry, and mineral geochemistry to address the (1) role of magma mixing and fractionation, (2) constraints on the relative timing of magma differentiation, (3) diversity of mixing styles preserved, and (4) physical properties that dictate how individual batches of magma interact within this sheeted complex. Rock samples were collected throughout the complex from mafic, felsic, dioritic, thinly-banded, and gradational sheets. Field evidence shows a range of sheet contacts that vary from sharp to diffuse, strong prevalence of mafic enclaves, and localized cases of mechanical mixing in which plagioclase feldspars from a felsic sheet are incorporated into a mafic sheet. In general, sheet thickness increases farther from the contact with the White River shear zone. The bulk rock and mineral chemistry suggests that the felsic magmas in sheets formed independently from the more mafic and hybridized sheets. The composition of the felsic sheets cannot be modeling by binary mixing processes involving mafic and felsic magmas or result from fractionating the most mafic magmas. However, mass-balance calculations using a linear least-squares mass balance calculation and Rayleigh fractionation models indicate that it is possible to explain the range of felsic compositions by internal, crystal fractionation driven mostly by plagioclase crystallization (~40-58%). Negative Eu anomalies in amphiboles from the felsic sheets imply that plagioclase fractionation commenced prior to the onset of amphibole crystallization. With the exception of the most primitive mafic sheet sampled, the mafic and hybridized sheets represent variable proportions of the mafic parental magma and the range of felsic differentiated magmas. Efficient mixing that resulted in these mafic to hybridized magmas must also have occurred prior to mineral growth as the mineral chemistry reflects intermediate, mixed compositions. The bulk rock and mineral chemistry of the most primitive, mafic sheet suggest that it did not mix with any felsic magmas. However there is evidence that the mafic sheet underwent plagioclase fractionation prior to emplacement. This is evident by lower bulk rock Sr/Ba relative to calculated Sr/Bamelt of plagioclase that cannot be reconciled without removing ~40-58% plagioclase. In contrast to the felsic sheets, the amphiboles from this mafic sheet lack Eu anomalies implying that amphibole crystallization occurred prior to major plagioclase fractionation. Chemical evidence reveals that magma mixing played an important role in controlling the chemical composition of individual sheets and field observations suggesting that there was a range of mixing styles. Throughout the sheeted complex, there are localized sites of mechanical mixing where plagioclase phenocrysts from adjacent felsic sheets are mechanically mixed into mafic sheets. Evidence for mechanical mixing is present across both sharp and gradational contacts. This implies varying rheological and viscosity contrasts between different sheets, though in both cases crystallinity and viscosity appears sufficiently low to allow crystals to migrate across sheet contacts. Variability in sheet thickness and contact type suggests that the physical parameters (i.e. temperature, viscosity, rheology, and magma flux) of the system continue to evolve throughout the formation of the sheeted complex. Near the White River, sheets are thin and more heterogeneous but become progressively thicker (>302 m) and more felsic in composition up-section. The composition of plagioclase and amphibole is remarkably uniform in all of the felsic sheets suggesting that each sheet formed from an array of felsic parental magmas. Thicker, felsic sheets most likely reflect hotter conditions where larger magma fluxes could be accommodated or viscosity-temperature contrasts that were low enough to allow for efficient mixing between two adjacent sheets and therefore erase sheet contacts. / Graduation Date: 2013

Glaciers respond to local climate changes making them important indicators of regional climate change. The North Cascades region of Washington is the most glaciated region in the lower-48 states with approximately 25% of all glaciers and 40% of the total ice-covered area. While there are many on-going investigations of specific glaciers, little research has addressed the entire glacier cover of the region. A reference inventory of glaciers was derived from a comparison of two different inventories dating to about 1958. The different inventories agree within 93% of total number of glaciers and 94% of total ice-covered area. To quantify glacier change over the past century aerial photographs, topographic maps, and geologic maps were used. In ~1900 total area was about 533.89 ± 22.77 km2 and by 2009 the area was reduced by -56% ± 3% to 236.20 ± 12.60 km2. Most of that change occurred in the first half of the 20th century, between 1900 and 1958, -245.59 ± 25.97 km2 (-46% ± 5%) was lost, followed by a period of stability/growth in mid-century (-1% ± 3% from 1958-1990) then decline since the 1990s (-9% ± 3% from 1990-2009). The century-scale loss is associated with increasing regional temperatures warming in winter and summer; precipitation shows no trend. On a decadal time scale winter precipitation and winter and summer temperatures are important factors correlated with area loss. Topographically, smaller glaciers at lower elevations with steeper slopes and higher mean insolation exhibited greater loss than higher, gentler more shaded glaciers.

The aims of this project were to develop a cascade approach towards decahydroquinoline frameworks (Scheme I) and apply this to the synthesis of decahydroquinoline-containing natural products such as lycopodine, cermizine B and lepadin D (Scheme I). Scheme I. Several linear precursors were synthesized via a modular strategy. For example, lycopodine linear precursor i was synthesized in a total of 12 steps (Scheme II). Scheme II. Conditions for cyclization and hydrogenation were tested, with the diastereoselectivity examined in each system. For example, the lepadin linear precursor ii produced two decahydroquinolines iii and iv upon cyclization (Scheme III). Scheme III. It was found that the diastereoselectivity was dependent on the ring substituents and variation of the hydrogenation conditions could change the facial selectivity of enamine reduction.

Effusive volcanic eruptions repave landscapes rapidly with lava flows, resetting the underlying landscape and ecosystem. The unique physical properties of lava pose interesting challenges for recovery, as lava flows can be highly permeable while lava itself is dense, sterile, and generally inhospitable towards life. This dissertation examines two aspects of landscape recovery following lava flow emplacement: (1) hydrologic adaptation of surface and groundwater to recent volcanism and (2) plant colonization of young lava flows. I examine two sites in the central Oregon Cascades: the c. 3 ka Sand Mountain volcanic field (SMVF), located in the headwaters of the McKenzie River, a critical water resource for the state of Oregon, and the c. 1.5 ka Collier Cone lava flow, originating on the north flanks of North Sister volcano. My investigation of the SMVF and upper McKenzie River watershed reveals a complex volcanic history with profound impacts on the configuration and short-term discharge of the McKenzie River: lava flows from the SMVF and other Holocene vents have buried, dammed, and altered the path of the McKenzie River. Moreover, given the large groundwater contribution from the SMVF to the McKenzie River, I estimate that SMVF activity caused McKenzie River discharge in present-day Eugene, Oregon to decrease by up to 20% for days to months at a time; future regional mafic volcanic activity could have a similar impact. The SMVF and the Collier Cone lava flow are notable for the juxtaposition of barren exposed lava and mature forests on the same or similarly aged lava flows. I use a combination of LiDAR analysis, field observations, and soil characterization to examine soil and vegetation at these two sites and find that the presence of an external soil source greatly facilitates plant establishment, growth, and survival. Here, external soil sources are syn- or post-eruptive tephra (SMVF) or flood-borne deposits (Collier Cone lava flow). External soil appears to provide a substrate for plants to grow in along with key nutrients and sufficient moisture; overall, external soil sources are key for the initial recovery following an effusive volcanic disturbance. This dissertation includes co-authored material submitted for publication.

Chiral amine motifs are found in many bioactive compounds and therefore strategies for their direct asymmetric synthesis are of great interest. Alongside traditional chemical methods, biocatalysis serves as an important tool for the formation of these compounds that can confer the benefits of sustainable catalyst supply and mild reaction conditions. This thesis describes the application of imine reductase (IRED) biocatalysts for the asymmetric reduction of pre-formed imines and the reductive amination of carbonyl compounds to produce chiral amines. These enzymes are relatively recent additions to the toolbox of biocatalysts for chiral amine synthesis and therefore their scope and application is still very much being explored. The research carried out as part of this PhD is presented as a series of manuscripts that have either been published or are planned for submission to peer-reviewed journals. The choice of presenting this thesis in journal format was made because a considerable body of the candidate's PhD research has been published, with the rest planned for publication in the near future. Furthermore, the compiled review articles and research papers lend themselves to a clear thesis narrative and, combined, have taken considerable time and effort to prepare, equal to that of a traditional thesis format. The contents are organised as follows: Chapter 1: an introduction to biocatalysis and its impact on sustainable chemical manufacturing; Chapter 2: a review assessing the current state of the art in imine reductase biocatalysts; Chapter 3: a perspective on the design and implementation of biocatalytic cascades; Chapter 4: a research article on the application of IREDs in a biocatalytic cascade for the synthesis of chiral piperidine and pyrrolidine frameworks; Chapter 5: aims of the PhD project; Chapter 6: a research article on the discovery and investigation of a reductive aminase (RedAm) found within the IRED family; Chapter 7: a research article on the screening of a diverse set of novel IREDs for their ability to facilitate reductive amination; Chapter 8: a research article on the synthesis of complex bulky dibenz[c,e]azepine compounds using IRED and transaminase biocatalysts; Chapter 9: a summary and outlook; Chapter 10: manuscript supporting information further detailing experimental work; Appendix: list of other publications resulting from this doctoral research.

Glaciers in the North Cascades store winter snowfall as ice and release it in late summer as melt, providing an important regional source of water and hydroelectric energy. The future of glaciers in the North Cascades, Washington, were evaluated using a regional glaciation model driven by the Community Climate System Model 4 global climate model. The climate model was coupled with three Representative Concentration Pathways (RCPs), 2.6, 4.5, and 8.5. These RCPs provide a business-as-usual scenario (RCP 8.5), which assumes society makes little to no efforts to reduce greenhouse gas emissions, a best-case scenario (RCP 2.6) with strong attempts to mitigate greenhouse gas emissions, and a moderate scenario (RCP 4.5). Spun up from 850 C.E., modeled glacier area for 1970 was 96-102% of observed. By 2100 the predicted area relative to the total observed area in 1900 was 42% for RCP 2.6, 16% for RCP 45, and 5% for RCP 8.5. By 2100 only glaciers on high peaks, such as Mt. Baker and Glacier Peak, will remain (145.98 km2, RCP 2.6; 70.49 km2, RCP 4.5; 16.82 km2, RCP 8.5) and entirely gone by 2200 in any of the three climate scenarios.

Le Gamma Large Array Space Telescope (GLAST), d es septembre 2007, observera les rayons entre 100 MeV et 300 GeV. Leur direction est mesurée par un trajectographe en couches à pistes de Si, leur énergie par un calorimètre rendu hodoscopique gr^ ace a la disposition de ses barreaux de CsI(Tl). Pesant près de deux tonnes, une structure en fibres de carbone rigidifiée par de l'époxy les soutient pour les protéger durant l'envol. Dans un barreau, un signal crée par un dépôt d'énergie est attenue en fonction de la distance parcourue. Un système de lecture compose d'une double diode a chaque extrémité permet alors de mesurer l'énergie déposée et sa position moyenne. Sur Terre, la calibration s'effectue grâce aux muons cosmiques. Un rayon interagit en créant une gerbe électromagnétique. Les contraintes spatiales sur la conception du calorimètre font que seule une fraction de l'énergie y aboutit, ce en fonction de l'énergie, l'orientation et la proximité aux parois de la gerbe. L'énergie (E) est reconstruite en optimisant, en fonction de ces paramètres, un estimateur base sur l'énergie mesurée dans le calorimètre (Q) et des observables réduisant la variance de Q car anti corrélées a celle-ci a Exe. L'algorithme de reconstruction procède à un maximum de vraisemblance sur cet estimateur. Les rayons extragalactiques peuvent initier des cascades électron-photon sur le fond de photons. Les spectres observes dépendent de l'atténuation des rayons, permettant en retour une mesure du fond infrarouge, et de l'émission de leurs cascades. Une signature spectrale du champ magnétique extragalactique est alors perceptible.

We have developed a novel framework that can be applied for the analysis of signal transduction networks, both to facilitate reconstruction of the network structure and quantitatively characterize the interaction between network components. This approach, termed activation ratio analysis, involves the ratio between active and inactive forms of signaling intermediates at steady state. The activation ratio of an intermediate is shown to depend linearly upon the concentration of the activating enzyme. The slope of the line is defined as the activation factor, and is determined by the kinetic parameters of activation and inactivation. When activation ratios for simple signaling systems are considered, a set of rules develop that can be used to transform a set of experimental data to a proposed model network structure, with activation factors yielding a measure of activation potential between intermediates. / Singapore-MIT Alliance (SMA)

We examine a model of social learning in networks following the lines of Bala and Goyal (1998, 2001). As a model of agents' behaviour we have chosen the model of informational cascades of Bikhchandani et al (1992). Similarly to Bala and Goyal we find that the higher the 'degree of integration' within the society is, the more likely it is that conformity of actions will arise. However, unlike their results our model suggests that in the presence of informational externalities globalisation of informational flows, expressed in the increasing density of communication channels in a network, may drive down the expected social welfare. (author's abstract) / Series: Working Papers Series "Growth and Employment in Europe: Sustainability and Competitiveness"