RNA silencing is an evolutionarily conserved system that
functions as an antiviral mechanism in higher plants and
insects. To counteract RNA silencing, viruses express
silencing suppressors that interfere with both siRNA- and
microRNA-guided silencing pathways. We used comparative
in vitro and in vivo approaches to analyse the molecular
mechanism of...
table isotope analysis is a powerful tool for assessing plant carbon and water relations and their impact on biogeochemical processes at different scales. Our process-based understanding of stable isotope signals, as well as technological developments, has progressed significantly, opening new frontiers in ecological and interdisciplinary research. This has promoted the...
Heat-related fruit damage is a common problem in the northern highbush blueberry (Vaccinium corymbosum L). This is particularly true in regions such as the northwestern United States, where summers are warm and dry, and daytime temperature regularly exceeds 32 oC. Millions of dollars of fruit damage are reported in blueberries...
This study described how and why a Korean elementary teacher taught mathematics as he did. Specifically, the study sought to describe his beliefs about the teaching and learning of mathematics and relate them to patterns of classroom interaction and norms.
An ethnographic inquiry guided the study of one third grade...
The purpose of this investigation was to describe tenth grade students' views
of the purposes of geometric proof within the context of their learning. Classroom
observations, the curriculum, assessment tools, journal questions, and a
preconceptions questionnaire were used to provide context for the views expressed by
students from a single...
Policy and research have increased attention in K12 mathematics education on core mathematical practices such as argumentation, justification, and proof, that are central to students learning and doing mathematics. One reason for this increased focus is the empirical evidence that engaging students in mathematical practices provide more equitable opportunities for...
There were two viable theories of generation, preformation
and epigenesis, existing in the Seventeenth and
Eighteenth Centuries. Due to their irreconcilable nature,
they were often at loggerheads during this time interval.
The status of these generation theories can be effectively
understood in terms of Thomas Kuhn's conception of preparadigm
science....
It has been held that heuristic training alone is not enough for developing one's mathematical thinking. One missing component is a mathematical point of view. Many educational researchers have proposed problem-based curricula to improve students' views of mathematical thinking. The present study reports findings regarding effects of a problem-based calculus...
The present study explored the effects of intranasal oxytocin (OT), a naturally occurring hormone, on the behavior of pet dogs in an attachment test. Each dog participated in two testing sessions. On one visit saline was administered nasally and on another OT was administered nasally. Condition order was counterbalanced. Following...
The domestic cat is one of the world’s most popular companion animals. However, to date much remains to be learned about cat behavior and the cat-human relationship. To examine the influence of proximate factors on cat behavior and the human-cat bond, three studies were undertaken. Study 1 directly measured the...
The ability of many domesticated animals to follow human pointing gestures to locate hidden food has led to scientific debate on the relative importance of domestication and individual experience on the origins and development of this capacity. To further explore this question we examined the influence of different prior training...
Public policy narratives and stories are often referenced by the media, politicians, advocacy groups, and across many disciplines in academia. Studies of social and political narratives support the notion narrative matters, but often lack systematic design capable of producing generalizable findings. The Narrative Policy Framework (NPF) has responded to this...
The domestic cat (Felis silvestris catus) has shared an intertwined existence with humans for thousands of years, living on our city streets and in our homes. Yet, little scientific research has focused on the cognition of the domestic cat, especially in comparison to human’s other companion, the domestic dog (Canis...
Statistically, travel by air is one of the safest forms of transportation. Yet we
continue to experience aviation tragedies. Do we fully understand flight safety or is
there another way of looking at the problem? In this work a new way of approaching
the question of flight safety is developed,...
Robotic limbs have been shown to enable mobility in unstructured, real-world terrain; they allow robots to step around cluttered environments, scramble up hills, carry heavy loads, and even perform acrobatics. However, mechanical limbs cannot operate as a means for such dynamic locomotion if they are simply treated as general articulated...
Papain-like leader proteases are found in diverse families of human, animal, plant, and fungal positive-strand RNA viruses. In addition to autocatalytic processing, these proteases play a variety of roles in the virus life cycle. In particular, the leader protease (L-Pro) of a prototype member of the Closterovirus genus, Beet yellows...
The past 30 years have witnessed a continued and growing interest in the production and comprehension of manual pointing gestures in nonhuman animals. Captive primates with diverse rearing histories have shown evidence of both pointing production and comprehension, though there certainly are individual and species differences, as well as substantive...
We constructed an experimental apparatus that used lasers to provide the probe beams for measuring the transient absorption kinetics of bacterioplankton that contain proteorhodopsin, a microbial protein that binds retinal and is analogous to animal rhodopsin. With this approach we were able to observe photocycles characteristic of functioning retinylidene ion...
Acetylene is a slow-binding inhibitor of the Ni- and Fe-containing dimeric hydrogenase isolated
from Azotobacter vinelandii. Acetylene was released from hydrogenase during the recovery from inhibition.
This indicates that no transformation of acetylene to another compound occurred as a result of the interaction
with hydrogenase. However, the release of C2H2...
Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually lead to tree death. To investigate the long-term impacts of dwarf mistletoe on gas exchange of host western hemlock trees, I compared growth, gas...
In eukaryotes, ARGONAUTE proteins (AGOs) associate with microRNAs (miRNAs), short
interfering RNAs (siRNAs), and other classes of small RNAs to regulate target RNA or target
loci. Viral infection in plants induces a potent and highly specific antiviral RNA silencing
response characterized by the formation of virus-derived siRNAs. Arabidopsis thaliana has...
Full Text:
that is processed by DCLs into 21- to 24-nt
short interfering RNAs (siRNAs), which subsequently
Gazing behavior is a vital part of nonverbal communication, as it can provide information about attentional state, subtext, environment, and point of view. Both dogs and cats have previously been shown to display gazing behavior when presented with an unsolvable task, as well as follow nonverbal directional ques given by...
RNA silencing pathways are required for a wide variety of processes in most
eucaryotes. In plants, small-interfering RNA (siRNA) arising from transposons and other
repetitive sequences is associated with heterochromatin formation and maintenance.
MicroRNAs and trans-acting siRNAs encoded at discrete loci function as negative regulators of
gene expression by triggering...
Presented in this paper is an analysis of the body of scholarly work that attempts to apply
Thomas Kuhn’s theory of scientific revolutions to mathematics. These applications vary on
several levels, from the authors’ interpretation of Kuhn’s original work to the definitions
used for terms such as paradigm, revolution, and...
Recalcitrance to transformation makes genetic engineering of many valuable plants infeasible for practical use. Transitory host modification during transformation using transgenes offers a possible means of overcoming this obstacle. In prior work in our laboratory, the genes GA20ox7 and EBB1 were found to increase regeneration in vitro. In this project,...
Full Text:
:10.1139/Y05-108.
Lakatos, L., Csorba, T., Pantaleo, V., Chapman, E., Carrington, J., Yu-Ping, L., et al
I was honored to be the keynote speaker at the 30th Annual Society of Toxicologic Pathology Symposium “Toxicologic Pathology and the Immune System.” I had the opportunity to reminisce about events in the 1970s that set the stage for the birth and subsequent growth of the field of immunotoxicology and...
Economic methodology is revisited to address issues in
fishery management, and survival analysis is suggested as an
analytical tool to solve the uncertainty problem in
evolutionary economics. Survival analysis can clarify in
statistical terms the impacts of fishery regulation and
economic and biological changes on the fisherman's final
decisions of...
Moisture content management is a key requirement to improve forest harvest residue economics for bioenergy production. This dissertation aims to contribute towards better management through these three general objectives (1) Determine average moisture content of fresh forest harvest residues and its changes over the different seasons of the year, focusing...
Previous research has shown a gap between chemistry students' conceptual
and computational understandings of chemistry topics such as gas laws,
equilibrium, and reactions. This qualitative study examined the conceptual and
computational understandings of stoichiometry of college students enrolled in a
large lecture Introductory Chemistry course. Factors that might influence students'...
Application of sewage sludge to soils increases the trace metal
content and the organic content of soils. The complexation of indigenous and added metals with organic constituents must be studied to
evaluate metal availability to plants and animals.
The water soluble organic fractions (WSOF) from an agricultural
soil (W), a...
Stable expression of transgenes is required for commercial uses of genetically engineered trees. To better understand the stability of transgene expression under field conditions, we studied transgene expression and RNA interference (RNAi)-induced transgene suppression in 2,480 transgenic poplars (460 transgene insertion events) over three years. Stability of expression was assessed...
The purpose of this study was to detail mathematical knowledge that supports the work of teaching proof and to investigate how such knowledge is evidenced in professional development (PD). To advance the construct of mathematical knowledge for teaching (MKT) in the context of proof, I developed a framework of MKT...
The variable length, six-electrode plasma source for atomic
emission spectroscopy described here is operated from three
compact, simple, and inexpensive direct current power supplies. The
vertical arcs formed between the three electrode pairs completely
entrain the sample and are typically operated at 40 V and 20 A.
Three concentric quartz...
Recent climate change forecasts have aroused growing interest in the influence of water
scarcity and climate on agricultural production and irrigation practice. However, it is common in
the economic literature to aggregate disparate crops when modeling irrigation choices. That
approach confounds the crop-specific effects of climate and water scarcity that...
Old-growth forests are structurally complex in both vertical and horizontal dimensions. This complexity arises from biological characteristics, typically branch and leaf structure, but also includes epiphytes with varying form and function. I characterized the biomass and species composition of epiphytes along the vertical axis of an old-growth Douglas-fir (Pseudotsuga menziesii)...
The development of problem-solving behaviors in canines, including persistence, has implications for canine training, welfare, and the human-dog bond. Past research has shown that a variety of factors, including genetics (domestication) and training experience, play a role in a how a canine might behave during a problem-solving task. Less well...
This study investigates what leads managers to allocate constrained cognitive effort toward new versus familiar aspects of a business. Specifically, we explore advice giving by venture capital firms (VCs) to their portfolio companies, distinguishing between business topics on which a VC has advised other ventures in the past and topics...
Robots have the potential to protect health care workers, provide patient care, and ultimately save lives in infectious disease outbreaks. Nevertheless, infectious disease outbreak scenarios present unique technological and social challenges for robotics. This work explores what robots can and should do in the fight against infectious diseases. We present...
This case study investigates how scientists who write technical marketing copy experience and resolve the tension that results from the conflicting demands of their local (company) and global (research science) discourse communities. Twelve scientists, who are currently technical marketing writers at a small biotechnology company, were interviewed by e-mail over...
Published March 1981. 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/catalog
Sediments are the major compartment in aquatic environments for many materials of toxic or nutrient concern. The lack of knowledge of the phase associations of toxic metals in sediments is the largest deficiency in our understanding of the environmental hazard posed by metal contamination. This study examined the sedimentary partitioning...
The aryl hydrocarbon receptor (AhR) has recently been described as a novel therapeutic target, given the potent suppression of multiple immune-mediated diseases following activation by the prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the parent-into-F1 graft-versus-host (GVH) model, suppression of the cytotoxic T-lymphocyte (CTL) response is associated with the presence of CD25⁺CTLA-4⁺IL-10⁺Foxp3[superscript...
The results of an investigation into carrier dynamics in several novel functionalized and solution-processable pentacene and anthradithiophene derivatives are reported. Measurements were made of real-time photoresponse of polycrystalline thin films of these materials to ultrafast laser pulses, on picosecond to microsecond time-scales, as well as measurements of dark current and...
The topics in this dissertation are centered around the way that trees respond to environmental stress in the climates where they occur. Though forests across the planet are expected to experience change in local climate due to historic and ongoing anthropogenic greenhouse gas emissions, the effects of climate change will...
Since at least the 1970s, rural areas in the western United States, as elsewhere across the country and world, have been subject to social, economic, and political forces that have resulted in novel demographic and land tenure trends when compared to previous decades. Collectively, these processes of restructuring have created...
Controversy regarding moral development research has given rise to a proliferation of theories competing for acceptance. For all these researchers, the work of Lawrence Kohlberg is the pivot point for comparisons, contrasts, and discussions. Still, no theories to date adequately describe and document a theoretically complete conception of moral judgment...
Early seral forests regenerating from stand-replacing disturbances provide unique habitat for many species in productive, temperate forest landscapes and contribute to supporting biodiversity. Population declines in some species associated with early seral forests have prompted concerns about the conservation of these habitats, particularly the characteristic structural and compositional complexity associated...