Shallow subsurface flow and surface runoff are spatially and temporally variable in forested environments. The location and timing of this runoff depends on both site characteristics (e.g., vegetation, soil texture, geology, and topography) and on time-varying conditions (e.g., soil water content, precipitation type, duration, magnitude, and intensity). Forest management activities...
Intraexciton transitions in semiconductor quantum wells are modulated by strong and tunable few-cycle terahertz pulses. Time-resolved terahertz-pump and optical-probe measurements demonstrate that the 1s heavy-hole and light-hole exciton resonances undergo large-amplitude spectral modulations when the terahertz radiation is tuned near the 1s–2p intraexciton transition. The strong nonlinear optical transients exhibit...
To characterize the mechanism through which myosin XI-K attaches to its principal endomembrane cargo, a yeast two-hybrid library of Arabidopsis thaliana cDNAs was screened using the myosin cargo binding domain as bait. This screen identified two previously uncharacterized transmembrane proteins (hereinafter myosin binding proteins or MyoB1/2) that share a myosin...
Interactions of few-cycle terahertz pulses with the induced optical polarization in a quantum-well microcavity reveal that the lower and higher exciton-polariton modes together with the optically forbidden 2p-exciton state form a unique Lambda-type three-level system. Pronounced nonlinearities are observed via time-resolved strong-terahertz and weak-optical excitation spectroscopy and explained with a...
Plants possess two myosin classes, VIII and XI. The myosins XI are implicated in organelle transport, filamentous actin
organization, and cell and plant growth. Due to the large size of myosin gene families, knowledge of these molecular motors
remains patchy. Using deep transcriptome sequencing and bioinformatics, we systematically investigated myosin...
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, Sergei A. Filichkin, Samuel E. Fox, Pankaj Jaiswal, Kira S. Makarova,
Eugene V. Koonin, and Valerian V
Image-based dietary intake assessment (IBDIA) is a new way by which the accuracy of dietary assessment can be improved through the use of digital images of food. The ability of nutrition and dietetics students and interns to accurately interpret images for diet intake assessment is currently unknown. An online survey...
Restoration of invaded aridlands is required to reduce the exorbitant ecological and monetary losses related to noxious weeds. An understanding of how reduced and increased levels of soil N and P influence interference between medusahead and squirreltail is imperative to understanding how squirreltail may be used in restoration of medusahead...
Bicyclists are one of the highest and most vulnerable road users. This is due to the higher likelihood of being seriously injured when involved in a crash. This research seeks to understand two different behavioral interactions of an implemented facility user: the motorist (secondary user) and bicyclist (primary user). The...
Racial, ethnic and gender diversity have been long term topics of discussion in natural resources. Yet to date, there has not been a comprehensive review of the existing literature within the discourse of demographic diversity. Therefore, I conducted a systematic review of demographic diversity in the disciplines of forestry, fisheries,...
The two studies of this dissertation examined mothers' perspectives of nonresident fathers' involvement in low-income families. The overall goal of these studies was to gain a more comprehensive understanding of nonresident fathers' involvement and its effect on family well-being. In the first study I applied a relatively new methodology, zero-inflated...
Biological plant invasions are diminishing the ecological integrity and function of ecosystems worldwide. A primary example of this is in the Great Basin of the United States, where invasive annual grasses, like cheatgrass (Bromus tectorum L.) and medusahead (Taeniatherum caput-medusae L. Nevski), are dominating many sagebrush-steppe ecosystems. In these invaded...
Labeling videos is costly, time-consuming and tedious. These costs can escalate in applications such as medical diagnosis or autonomous driving where we need domain expertise for annotation. Few-shot action recognition aims to solve this problem by annotation-efficient learning mechanisms.
This thesis presents MetaUVFS as the first Unsupervised Meta-learning algorithm for...
Knowledge of stand structure, stand dynamics, and production ecology of species mixtures lags well behind that of single-species, even-aged stands. Two mixed-species spacing trials in central Oregon allowed investigation of mixed-species dynamics in a controlled experimental setting. The first site, Pringle Butte, is a mixture of ponderosa pine (Pinus ponderosa...
Montane meadows comprise a small area of the predominantly forested landscape
of the Oregon Cascade Range. Tree encroachment in the last century in these areas has
threatened a loss of biodiversity and habitat. Climate change in the coming century may
accelerate tree encroachment into meadows, and exacerbate biodiversity loss. Multiple...
Limnology is undergoing a transition to high-throughput -omic analysis of freshwater
bacterial communities. An important first step in making the transition is to
characterize several genomes that can be used as references to guide metagenome
assembly and analysis. Here I characterize four new freshwater cyanobacterial
genomes, a pair of lake...
In 2007, the Centers for Medicare and Medicaid Services began requiring many hospitals in the United States to randomly survey patients who had stayed at least one night in the hospital. The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey provides hospitals with valuable performance measurement data built...
Healthcare discrimination is associated with various health-related attitudes, behaviors, intentions, and outcomes including provider avoidance, underutilization or increased use of healthcare services, use of alternative means of healthcare, delays in medical care, less satisfaction with care, poor health behaviors, and poorer health outcomes. Since 2001, Muslims and Arabs in the...
The aqueous chemistries of two transition metal cations, Zr⁴⁺ and Nb⁵⁺, are examined and then used to develop inorganic precursor solutions. The oxides of these cations (ZrO₂ and Nb₂O₅) are deposited and characterized, and their morphological and optical properties discussed. Due to the obstacles created by niobium's aqueous chemistry, an...
In this thesis, I present a new method we developed to study low frequency (< 700 cm⁻¹) vibrational dynamics: Time-resolved third-harmonic generation (TRTHG) spectroscopy. Among a variety of vibrational spectroscopy techniques, TRTHG differentiates itself with robustness, versatility, and simplicity. In TRTHG experiment, that involves only two ultrashort laser pulses, the...
Utilizing anti-racist feminist research methodologies, Making Sense of Social Justice Education: A Case Study of the Difference, Power, and Discrimination Program, argues that institutions of higher education must attend to local histories of student activism and faculty development in their efforts to create social justice-informed structural change. Increasingly colleges and...
Advances in forest carbon mapping have the potential
to greatly reduce uncertainties in the global carbon
budget and to facilitate effective emissions mitigation strategies
such as REDDC (Reducing Emissions from Deforestation
and Forest Degradation). Though broad-scale mapping
is based primarily on remote sensing data, the accuracy of
resulting forest carbon...
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stocks
M. Réjou-Méchain et al.
Correspondence to:M. Réjou-Méchain (maxime.rejou@gmail.com
Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) is an arboreal, hemiparasitic plant that principally parasitizes western hemlock (Tsuga heterophylla). Hemlock dwarf mistletoe exerts a profound influence on infected trees that can drastically change the structure of the tree crown due to reduced growth, top dieback, branch deformation and death, resulting...
How the direct and indirect effects of species interactions cascade to affect community structure, functioning, and stability is a fundamental question in ecology. In temperate kelp forests, species interactions, in conjunction with environmental processes, produce rich spatiotemporal dynamics.
Arguably the most dramatic of these are abrupt shifts in community state,...
Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to treat. In recent years, extracellular DNA (eDNA) has been found to be a major component of bacterial biofilms, including many pathogens involved in biofilm-associated infections. To date, eDNA...
Forest ecosystem dynamics emerges from nonlinear interactions between adaptive biotic agents (i.e., individual trees) and their relationship with a spatially and temporally heterogeneous abiotic environment. Understanding and predicting the dynamics resulting from these complex interactions is crucial for the sustainable stewardship of ecosystems, particularly in the context of rapidly changing...
• Premise of the Study: Tropical liana abundance has been increasing over the past 40 yr, which has been associated with reduced
rainfall. The proposed mechanism allowing lianas to thrive in dry conditions is deeper root systems than co-occurring trees,
although we know very little about the fundamental hydraulic physiology...
Non-equilibrium photocarriers in multilayer WSe2 injected by femtosecond laser pulses exhibit extraordinary nonlinear dynamics in the presence of intense THz fields. The THz absorption in optically excited WSe2 rises rapidly in the low THz field regime and gradually ramp up at high intensities. The strong THz pulses drive the photocarriers...
M. avium is an opportunistic pathogen that primarily infects macrophages. In order to survive within the macrophage, M. avium secretes proteins into the host cell cytoplasm to inhibit specific functions such as phagosome acidification, altering pathways as well as initiating apoptosis. However, little is known about how those secreted proteins...
Mycobacterium avium subsp. hominissuis is an opportunistic human pathogen that has been shown to form biofilm in vitro and
in vivo. Biofilm formation in vivo appears to be associated with infections in the respiratory tract of the host. The reasoning behind
how M. avium subsp. hominissuis biofilm is allowed to...
Quaking aspens (Populus tremuloides Michx.) are found in diverse habitats throughout North America. While the biogeography of aspens' distribution has been documented, the drivers of the phenotypic diversity of aspen are still being explored. In our study, we examined differences in climate between northern and southwestern populations of aspen, finding...
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calculation is taken from Kira (1976), who originally
referred to it as a ‘warmth index.'
Monthly
Disturbance processes of various types substantially modify ecosystem carbon dynamics both temporally and spatially, and constitute a fundamental part of larger landscape-level dynamics. Forests typically lose carbon for several years to several decades following severe disturbance, but our understanding of the duration and dynamics of post-disturbance forest carbon fluxes remains...
Five newly released and two Eastern European winter wheat
cultivars were grown under five different seeding rates (80, 160,
240, 320, 400 seeds per m²). Four of these newly released cultivars
were grown at three different locations which have different environmental
conditions. Data were obtained on grain yield, tiller number...
The purpose of this study was to investigate the effects of wildfire on soil hydraulic properties of forested hillslopes. The study site was located within the Stouts Creek wildfire, which burned approximately 10,705 ha of forest in southwestern Oregon in summer 2015. Three soil hydraulic properties (soil moisture, unsaturated hydraulic...
Plant invasion and restoration outcomes
are largely driven by the timing and magnitude of seed
dispersal, and by the performance of dispersed species
in an environment. Because seed dispersal controls
recruitment of newly arriving species and facilitates
safe site occupation, assembly will differ depending
on seed dispersal processes and variable...
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on seedlings during
invasion and restoration of shrub-steppe
Schantz, M. C., Sheley, R. L., & James
The metabolic theory of ecology (MTE) predicts the effects of body size and temperature on metabolism through considerations of vascular distribution networks and biochemical kinetics. MTE has also been extended to characterise processes from cellular to global levels. MTE has generated both enthusiasm and controversy across a broad range of...
Vegetation ecology of eight Oregon freshwater wetlands was
described and net aerial primary productivity estimated in four
wetlands. Plant cover samples were used to classify 37 wetland and
11 terrestrial communities by agglomerative hierarchical clustering.
Samples and species were ordinated. Direct measurements were made
of sample relative elevation, inundation duration,...
Mangrove forests store more organic carbon across ecosystem carbon pools than most other coastal and forested ecosystems, and are subject to high global rates of deforestation. For these reasons, they are recognized as prime candidates for inclusion in climate change mitigation strategies. However, the ecological drivers of regional and micro-scale...
Conceptually, the dynamics of wood in streams can be viewed in terms of input and in-channel processes. Input processes are associated with both the riparian (tree fall, bank cutting, windthrow) and upslope forests (mass failures). In-channel processes include log breakage, movement, and decomposition. A mechanistic view of these processes is...
Large wood (LW) pieces are recognized as an important habitat component for salmon freshwater habitat. As such, they are often used in stream habitat restoration practices despite a lack of knowledge about their impacts on spatial and temporal hydraulic characteristics relevant to fish habitat. In this thesis we present results...
The spatial and temporal variability of sediment transport processes in Oak Creek, OR was investigated and used to explore two study questions: 1) How do sediment transport processes influence benthic algal communities?, and 2) Can fluvial-hydraulic models make accurate predictions of bed load transport rates? Our study was conducted in...
This thesis will cover work that I have completed relating to the field of terahertz (THz) science. My work has consisted of generating tunable, narrowband THz pulses in a table-top optical setup and using both narrow- and broadband THz pulses to study various material systems. Broadband THz pulses were used...
The distribution of Lahontan cutthroat trout Oncorhynchus clarki henshawi was assessed in a high-desert stream in southeastern Oregon where beaver Castor canadensis are abundant. Longitudinal patterns of beaver ponds, habitat, temperature, and Lahontan cutthroat trout age group distribution were identified throughout Willow Creek. Three distinct stream segments were classified based...
Mitigation strategies for reducing CO2 emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be re-captured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here we use forest inventory data to show that...
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% in California
(Supplementary Table S2). NPP ranges from 100 to 900 g C m-2 across the region and
"This report presents a reference list of available studies on aboveground forest biomass, together with (1) methods of sampling and estimation and some of the problems and errors associated with each method (given as an aid to comparison of data), (2) some results obtained from the literature of field estimates...
This work comprises two main parts: creating and shaping narrowband, pulsed THz radiation in a table-top optical setup; and applying THz pulses to semiconductor nanostructures to study electron dynamics.
I developed a scheme to shape the THz output of a fanned-out periodically poled lithium niobate (PPLN) crystal. The pulses are...
Sequential supervised learning problems involve assigning a class label to each item in a sequence. Examples include part of speech tagging and text to speech mapping. A very general-purpose strategy for solving such problems is to construct a recurrent sliding window (RSW) classifier which maps some window of the input...
The silviculture of mixed dipterocarp forests of Peninsular Malaysia can potentially be improved by developing quantitative tools and guidelines for this forest type. This thesis addresses three key objectives; 1) to test the hypothesis that a maximum size-density relationship can be identified in hill dipterocarp forests of Peninsular Malaysia, 2)...