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Habitat Associations and Diet Composition of Western Purple Martins in Western Oregon
Get PDFThe western purple martin (Progne subis arboricola) is a species of conservation concern throughout the Pacific Northwest. In western Oregon, the purple martin nests in three major ecosystem types: inland open-water, coastal, and upland forest. The availability of suitable breeding habitat is a major limiting factor for western purple martin populations and has likely decreased as a result of timber harvest reductions under the Northwest Forest Plan. As a cavity-nesting species that forages on airborne insects, purple martins require nesting structures in open habitat with high insect productivity. From anecdotal observations, it is assumed that dragonflies are a major prey item of purple martins. Prey limitations are unknown, as studies on the diet of western purple martin have not yet been done. An understanding of how availability of both suitable nesting cavities and prey resources limit populations is critical for developing a conservation strategy for this species.
The goal of my first study was to provide an assessment of the current status and distribution of the purple martin population nesting in upland forest in western Oregon. The objective of my habitat study was to determine the probability of occupation of purple martins at potentially suitable nesting sites in western Oregon, and to develop a prediction model of habitat suitability based on a comparison of habitat attributes at multiple spatial scales measured at used and unused sites. Each of
the variables that we used to characterize purple martin habitat were significantly different between used and unused nest sites except for snag DBH. We found strong statistical evidence that the odds of purple martins occupying a snag are affected by the area of early seral habitat within a stand. Despite the major limitation of lacking contiguous snag-level data for the study area, our prediction model of habitat suitability scores a “B” on the traditional academic point system with an AUC fit index of 0.8134. We intend this model to be useful in estimating the amount of suitable habitat available to support purple martin colonies both currently and under future timber harvest regimes.
The goal of my second study was to provide the foundational information on diet that will be necessary for further studies on nest site and prey limitations. The objective of my diet study was to illuminate diet composition and differences in diet composition between ecosystem types. I sampled prey composition at each ecosystem type to provide an index for prey availability. I utilized the noninvasive and innovative method of metabarcoding to produce a list of insect prey for purple martins in western Oregon. The abundance of dragonfly prey was higher at inland open-water sites compared with coastal and upland forest sites. Small insect biomass did not significantly differ between ecosystem types, though a trend of large insect hatches appeared only in open-water ecosystems.
My study fills important information gaps about suitable nesting habitat for the western purple martin and how nest site influences diet. I intend the predictive model of habitat suitability to be useful in estimating the amount of suitable habitat available to support purple martin colonies both currently and under future timber harvest regimes. I identified major limitations in statewide data availability for purple martin nesting habitat. It is recommended that further research aims to improve the continuity of snag data in western Oregon. Now that we understand the differences in diet among ecosystem types, we can target important prey taxa in sampling efforts to determine if and where prey limitations may exist. This study will guide wildlife
managers as to where their efforts to protect or bolster existing populations will be most effective
Advances in Simultaneous Translation
Get PDFSimultaneous translation, which translates concurrently with the source language speech, is widely used in many scenarios including multilateral organizations. However, it is well known to be one of the most challenging tasks for humans due to the simultaneous perception and production in two languages. On the other hand, simultaneous translation is also notoriously difficult for machines and has remained one of the holy grails of AI. The key challenge is the word order difference between the source and target languages. There have been efforts towards genuine simultaneous translation, but all these efforts have the following major limitations: (a) none of them can achieve any arbitrary given latency; (b) their base translation model is still trained on full sentences; and (c) their systems are complicated, involving many components and are difficult to train. In this thesis, we start by introducing several simultaneous translation approaches with two orthogonal categories: fixed or adaptive latency policies; trained on full sentences or not. Then, we investigate how to improve simultaneous translation with beam search which is universally used in full-sentence translation but non-trivial to be applied in simulta- neous translation. Finally, we explore speech-to-speech simultaneous interpretation by incorporating streaming ASR and incremental TTS
Investigation of the Initial Stages of SiGe(001) Dry Thermal Oxidation Using Ambient-Pressure X-ray Photoelectron Spectroscopy
Get PDFAmbient-pressure X-ray photoelectron spectroscopy has been used to study the initial stages of dry thermal oxidation of Si₀.₆₀Ge₀.₄₀(001) grown epitaxially on Si(001). Chemical state resolved AP-XPS was performed at temperatures up to 300 ˚C and O₂ pressures up to 1 mbar. Comparisons were made to Si(001) and Ge(001). The Si 2p and Ge 3d core levels were monitored to study oxide growth in-situ. Experimental data was analyzed using the NIST Simulated Electron Spectra for Surface Analysis (SESSA) to determine oxide composition and thickness. Our analysis indicates that oxidation proceeds via three oxide growth rate regimes: rapid regime within the first 20 minutes of oxidation when the oxide was thin, a transitionary regime, and a quasi-saturated slow regime when the oxide was relatively thick. The oxidation of both Si and Ge during the rapid regime was found to be pressure dependent, where both rates decreased at lower O₂ pressures. The rapid regime oxidation rate for Ge was reduced compared to Si at lower O₂ pressures, resulting in significant suppression of GeO₂ formation compared to SiO₂. Results indicate that the rapid regime oxide growth rate at 300 ˚C was 96 and 65 Å/h for O₂ pressures of 1 and 0.01 mbar, respectively. This rapid regime rate was primarily driven by SiO2 - formation. At low pressure, significantly less Ge was incorporated into the oxide and the final oxidethickness was ~5 Å thinner. The Si and Ge oxidation rates in the slow regime were nearly the same for our experimental conditions. The slow regime growth rate at 300 ˚C was 3.3 and 3.9 Å/h for O₂ pressures of 1 and 0.01 mbar, respectively. Finally, the mixed oxide Ge fraction and thickness was found to be strongly dependent on rapid regime oxidation. An enhancement of the Si₀.₆₀Ge₀.₄₀(001) oxidation rate was observed relative to Si(001) and Ge(001), and this was for both the rapid and slow regimes
Archaeological Textile Fragments Present an Opportunity In the Study of Social and Landscape Interactions
Get PDFTextiles (including basketry, cordage, woven, knotted, or plaited products) make up a considerable portion of the perishable archaeological record in dry caves of the northern Great Basin region, much of which is created from plants and plant fibers. The archaeological study of precontact textiles greatly informs our understanding of how people lived in the past. In this thesis, a well-established technique, strontium isotope sourcing using 87/86 Sr isotopes, is investigated as a tool to assess the geographic location of plant harvests providing the material for making these textile products during the time period of the Younger Dryas (12.9 – 11.6 ka) to the early Holocene (11.6-8 ka). This period is characterized by a shift from cool and wet to warmer and drier conditions in the northern Great Basin. However, the past plant life of this region is essentially the same as what is seen today but is distributed differently (Saban 2015, Beck et al. 2017, Dexter-Kennedy 2018). Given this continuity in vegetative patterns, strontium isotope ratios sampled from the surface waters and plants in modern landscape were used to establish a baseline signature for bioavailable strontium in Summer Lake basin. Isotopic study of early textile artifacts from the Paisley Caves site revealed a match with modern plants growing in the Summer Lake Basin. These results, although preliminary, are encouraging and support the further development of a strontium-based provenance system for textiles that can be used to study landscape interactions among precontact Great Basin peoples
Exploring Volcano-Tectonic Connections in Cascadia – Temporal Linkages between Tephra Deposition and Megathrust Earthquakes
Get PDFExplosively erupting volcanoes and megathrust earthquakes (Mw 8+ magnitude) occur at subduction zones and adjacent volcanic arcs. Volcanic eruptions are observed occurring close in time to megathrust earthquakes in the historical record from at least the 18th century CE to present in locations globally, including Japan in 1707 CE (Chesley et al., 2012) and 2011 CE (JAXA Space Technology Directorate); Chile in 1960 CE (Lara et al., 2004) and 2010 CE (Swanson et al., 2016); Kamchatka in 1952 CE (Walter, 2007); Alaska in 1964 CE (Walter et al., 2009); Sumatra 2005 CE (Walter et al., 2009); and Indonesia 2018 CE (Kim Hjelmgaard, 2018). Additional timing linkages between megathrust earthquakes and volcanic eruptions are also identified in Kamchatka, Alaska, and Central America (Walter et al., 2009). Previous research has been conducted exploring possible triggering relationships in other subduction systems; however, the Cascadia Subduction Zone (CSZ) has yet to receive attention from researchers regarding CSZ and Cascadia Volcanic Arc (CVA) triggering potential. The CSZ poses a significant hazard to the North American Pacific Northwest. If synchronicity can be established between CSZ megathrust seismic earthquakes and CVA volcanism, further research is required to establish the physical mechanisms linking these phenomena. The first step in this process is to establish that such correlations exist, which is the central focus of the present work. Thus, refining scientific understanding of these dual geohazards provides improved geohazard assessments and better informs emergency planners.
This analysis of the volcano-tectonic connections in Cascadia and temporal linkages tephra deposition and megathrust earthquakes includes the refinement of the Holocene paleoseismic and tephrochronology records. These records are found within both marine, and lacustrine sediment cores contain seismoturbidite sequences, and tephra deposits may provide detailed stratigraphic relationships and ages of seismic and volcanic events. The purpose of this research is to achieve a higher temporal resolution of regional CSZ megathrust earthquakes and eruptive histories of the CVA by correlating the 14C ages and stratigraphic occurrence of tephra and turbidite deposits between lake and marine sediment cores collected in the U.S. Pacific Northwest. Geophysical data collected from Lake Wapato and Rogue Apron sediment cores are stratigraphically correlated with previously established event bed data with sediment cores collected at inland Washington lakes and marine sediment cores collected along the CSZ margin. 14C age data collected within Lake Wapato provide stratigraphic control and correlates Lake Wapato and Rogue Apron records with established CSZ turbidite records.
An analysis of the stratigraphic relationship between primary volcanic tephra beds and seismoturbidites in lake and marine cores in this study suggests that some CSZ and CVA event beds are observed in close stratigraphic proximity. Mazama tephra beds appear to occur immediately before the CSZ T14 event bed, observable in both lake and marine cores assessed in this study. Mount Saint Helens tephra bed Wn is observed in the Wapato core record and appears to occupy the CSZ T2 event bed's stratigraphic position. Additionally, the Mount Saint Helens tephra bed Yn is observed at the same depth as the CSZ T8 event bed in the Wapato core record. In the Bull Run Lake core record, the Mount Hood Timberline tephra bed is observed where the CSZ T5 event should be located. In assessing the extant CVA Holocene eruptive data compared against the CSZ Holocene turbidite record, numerous potential timing linkages are suggested
Cultural and Linguistic Inclusiveness in the U.S. University Spanish Classroom
Get PDFWith a growing diversity in U.S. universities, departments of World Language Education (WLE) welcome more students from a wide range of linguistic and cultural backgrounds every year. However, research shows that traditional approaches to the teaching of Spanish as a world language (WL) focus primarily on the educational needs of white, English monolingual students, and impose barriers on international and heritage students –a minority in the Spanish classroom. Calls to challenge hegemonic approaches to Spanish as a WL highlight the need for inclusive pedagogies that address the needs of students from linguistic and cultural minorities. To better understand the opportunities for the application of more inclusive approaches in first-year Spanish classes, in this dissertation I explore the experiences of international and heritage students and how their linguistic and cultural identities are recognized in the class. Findings from grounded theory and thematic narrative analysis emphasize the need for more inclusive and equitable approaches to the teaching of Spanish that center language learning on the minoritized students’ cultural knowledge and lived experiences. Specifically, I challenge the dominant story of university Spanish as a WL with the students’ counter stories, bringing their voices to the fore and highlighting aspects of their stories that are not typically recognized in the classroom. Looking across the students’ counter stories, I discuss the findings and make recommendations for instructors and departments of WLE. In presenting these findings, I aim to bring awareness of the realities of our international and heritage students, and of the need for inclusive approaches that incorporate the students’ languages and cultures into their learning
Benefits of youth sports
Get PDFThe National Youth Sports Strategy aims to unite U.S. youth sports culture around a shared vision: that one day, all youth will have the opportunity, motivation, and access to play sports—regardless of their race, ethnicity, sex, ability, or ZIP code. Why youth sports? Research shows that participating in youth sports can lead to immediate and long-term benefits for youth, their families, and communities
Application of GNSS for Vertical Reference Determination
Get PDFVertical datum is a reference system used for specifying the elevation of specific points on or near the Earth. Precise and accurate definition and realization of vertical references are, therefore, crucial to ensure consistency between height measurements. The vertical datums can be divided into two categories: 1) vertical geodetic datums and 2) tidal datums, depending on how they are defined and realized.
Leveling is a traditional geodetic surveying technique that has been used to realize a vertical geodetic datum. The North American Vertical Datum of 1988 (NAVD88), the current vertical datum for the contiguous United States and Alaska, was established by adjusting the Canadian-Mexican-United States leveling observations. Although great care of NAVD88, it has been identified that NAVD88 is slightly tilted from a geopotential surface and is biased from a least-squares fit of mean sea level. However, re-leveling the continent is cost-prohibitive and may still yield heights with large errors from a geopotential surface.
On the other hand, the tidal datum is determined by tidal measurements observed from a tide gauge that is the one of the conventional water level monitoring facilities. However, some challenges of the tide gauges are identified as it required the direct contact with the water. First, installing and maintaining the tide gauge is limited, especially, in extreme environments. Second, the tide gauge is vulnerable to coastal hazards due to potential measurement errors or equipment destructions.
Considering the needs in the field of the vertical datum determination, this research explores several novel approaches and techniques utilizing GNSS:
First, the optimal combination of the height information from the leveling, GNSS and a geoid models is computed by applying a novel algorithm, Corrector Surface Model (CSM). This study shows the concept of the virtual surface, which compensate the discrepancy between those height measurements, to the real data. In addition, the theoretical algorithms of the combined adjustment are applied to an empirical case study conducted on the selected study area in Oregon for the validation and evaluation.
Second, the capability of GNSS for measuring water levels is introduced to establish the basic vertical reference plane by complementing the inconsistency between tidal and geodetic datums. The suggested algorithms are validated by a case study conducted in Cameron, LA during Hurricane Harvey, in 2017, which results reveal that modernized GNSS with an enhanced spectral analysis enables to accurately measure the water levels with high temporal resolution even during an extreme weather event.
In addition, the research examines the feasibility of utilizing GNSS-R for realization of vertical datum in the Arctic. For the vertical datum, the water level changes are conventionally monitored by a tidal gauge. However, installing and maintaining tide gauges in the Arctic is challenging due to the extreme environment. In order to overcome the limitation of the traditional tidal gauge, GNSS-R is utilized as an alternative water level monitoring method in the Arctic, which measures the water levels based on remote sensing technique. Considering that GNSS performance at high latitudes is degraded due to satellite geometry and ionospheric effects on GNSS signals, an advanced GNSS-R algorithm is implemented, which successfully measures the highly accurate and precise water level variation in an environmentally challenging region.
Finally, GNSS-R technique is adopted for the post-event analysis by taking an advantage of remote-sensing nature of GNSS-R technique. To detect the extreme change of water level, enhanced GNSS-R data processing methods are applied which includes the utilization of multi-band GNSS signals, determination of optimal processing window, and Kalman filtering for height rate determination. In addition, the impact of coastal hazards on water level retrievals is assessed by introducing the confidence level of retrieval (CLR) that indicates the probability of dominant peak representing the roughness of the water surface. The proposed approach is validated by two tsunami events, induced by 2012 Haida Gwaii earthquake and 2015 Chile earthquake and two storm surge events, induced by 2017 Hurricane Harvey and occurred in Alaska in 2019.
The key contribution of this research is the utilization of GNSS for the modernized vertical reference determination by compensating the inconsistency between the geodetic and tidal datums
Sheep and Goat Grazing on Fort Ord National Monument from 1998 – 2019: Implications for Restoration
Get PDFSince 1960 sheep have been used to reduce fuel accumulation on Fort Ord National Monument (FONM) grasslands. From 1997-2019 BLM’s monitoring projects were employed to determine livestock grazing impacts on Coyote Brush, bunchgrasses, and other native and non-native herbaceous vegetation. In 2014, the Bureau of Land Management (BLM) determined that passive sheep grazing was not being effective at reducing fuel loads, and transitioned into using a combination of passive and targeted goat grazing as a management tool. ‘Goats R Us’ provide BLM livestock to graze grasslands from October – April. Grazing objectives are 1) reduce encroachment of Coyote Brush Scrub into Coastal Grassland, 2) reduce residual dry matter (RDM) to 1200 lb/acre, and 3) increase abundance of native grasses and forbs. Since 2014, BLM has determined that goat grazing can reduce the encroachment of Coyote Brush Scrub, however there has been a concurrent increase in abundance of non-native forbs and annual grasses. BLM and its partners are experimenting with new techniques of goat grazing to reduce biomass of non-native grasses and to promote native grassland diversity. One technique being evaluated is targeted goat grazing select areas of coastal grassland 2-3 times per year. Results suggest that this reduces the cover of non-native grasses, creates open ground for forb and bunchgrass abundance to increase and provides the most reduction in fuel accumulations. This targeted grazing regime gives the BLM an opportunity to manage coastal grassland to both reduce fuel accumulation and increase native plant abundance in FONM Coastal Grassland
Certification of tree seed
No full textPublished June 1983. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo