An ambrosia fungus is described from filamentous sporodochia adjacent to a wood-boring ambrosia beetle (Coleoptera: Curculionidae: Platypodinae) in mid-Cretaceous Burmese amber. Yeast-like propagules and hyphal fragments of Paleoambrosia entomophila gen. nov. et sp. nov. occur in glandular sac mycangia located inside the femur of the beetle. This is the first...
We assessed the parasitism of Metaparasitylenchus hypothenemi on its host, the
coffee berry borer, in 20 coffee plantations of Mexico. A total of 23,568 adult
borers were dissected, with 179 of these infected with nematodes (0.76% infection
rate). Although the level of parasitism is not encouraging, the nematode is another...
Coral reef ecosystems continue to be significantly altered by disease epizootics, but why some host populations remain resistant while others succumb to outbreaks remains unknown. Research across diverse animal and plant host systems has revealed that disease severity is strongly influenced by host genetics and by environmental influences on both...
Woody biomass transportation costs and market values/costs are strongly correlated with the woody biomass moisture content. Properly managing moisture content can potentially lead to economic and environmental advantages in biomass energy markets. Good management requires accurate moisture content measurements. Therefore, availability of accurate, precise, reliable, and efficient tools to assess...
A dynamic approach to the Bayesian theory of sampling inspection
by attributes for the single sampling case is presented. A model is
developed which assumes a sequence of lots of equal known size and
lots generated by a process operating in a random manner. The model
also assumes constant associated...
Linear phase variable filters that are obtained with a frequency transformation of the form cos(ω) = P(cos(W)) were analyzed, where P is a finite degree polynomial, ω is the prototype frequency and W is the transformed filter frequency. A new transformation of third order is proposed. The new variable filter...
This thesis contains three parts addressing the asymptotic analysis of fluid flow through fully saturated porous medium in the presence of an adjacent thin channel.
In the first part the problem is modeled by Darcy's law in both the porous medium and in the channel. The permeability in the channel...
The objectives of this study were to evaluate and compare the
availability of native and applied P in Central Oregon pumice soils
with that in Willamette valley soils and calcareous soils from Eastern
Oregon. The experimental work to meet these objectives included
laboratory and greenhouse studies.
The removal of P...
A Cost-Effectiveness Analysis of a targeted intervention for community control of Ascariasis was carried out in three rural communities near Quito, Ecuador. Targeted treatment with Paico (Chenopodium ambrosioides) and Albendazole (ABZ) was applied to children aged 5 to 15 years attending primary local schools in Aglla, Checa and Iguinaro. Prevalence...
Spatial Supervised Learning seeks to learn how to assign a label to each pixel in a spatial grid
such as the pixels of remote-sensed images. The standard approach is to treat each grid cell
separately and to use only the measured features of the grid cell to determine the assigned...
Full Text:
Supervised Learning 1
Masters Project
Spatial Supervised Learning
Dan Vega
June 2005
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Coral reef health has been in severe decline around the globe in the past several
decades, in many cases due to direct human impact. Human action, such as overfishing,
habitat destruction and nutrient loading, has caused coral coverage to drop to record lows,
threatening the future of these critically important...
Polyfunctional thiols are sulfur containing compounds that are important to the flavor and aroma profile of some foods and beverages. S. Cerevisiae has been shown in wine yeast that it is capable of producing these thiols to create a fruity aroma and flavor profile. IRC7, a gene that codes the...
This research examines whether alternative methods of export commodity promotion and market development, such as technical training and trade servicing activities, have been successful in increasing the demand for grass seed produced in Oregon in international markets. A single equation linear input demand model and a linear model adjusted to...
With a growing minority population in Oregon classrooms, the demand of knowledge from both minority parents and teachers has grown. Minority parents want to learn more about navigating the education system in Oregon and teachers want to learn how to help them. In this paper I analyzed data from TEAMS...
Spatial Supervised Learning seeks to learn how to assign a label to each pixel in a spatial grid
such as the pixels of remote-sensed images. The standard approach is to treat each grid cell
separately and to use only the measured features of the grid cell to determine the assigned...
Full Text:
P. Vega
School of Electrical Engineering and Computer Science
Oregon State University
Corvallis
Coral reefs are diverse ecosystems and serve many purposes including preventing erosion on coastlines and acting as a source of food, income, and culture. Acropora cervicornis, a staghorn coral, has faced a significant 80-89% decline in the Caribbean, attributed to a poorly-characterized epizootic, White Band Disease (WBD). Previous studies showed...
On coral reefs, disturbances rarely occur in isolation. Global stressors such as increasing seawater temperature often coincide with local stressors like nutrient pollution. In the face of increasing anthropogenic stress, corals can function as environmental sentinels, although little is known about how multiple stressors interact to disrupt their associated bacterial...
As important ecological cornerstones, coral reefs face threats from a myriad of sources, such as global climate change, and importantly, disease, the latter often as a result of microbial pathogens. An understudied group of major corals, fire corals, and their even less understood microbiome present an opportunity to learn more...
Stony corals are the ecosystem engineers of the vital, dynamic, and complex marine ecosystem known as coral reefs. Globally, coral reefs are undergoing degradation from multiple anthropogenic stressors. Coral reef organism holobionts, or the host along with its microbial components, are key to reef ecosystem success and functioning. Marine microbes...
Corals have multiple roles in maintaining ocean health and are some of the world’s most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host...
In host-associated microbiomes, the mechanisms that regulate community composition or the principles that govern dynamics remain far from clear. However, understanding how the structure of microbial communities shift as the system moves away from a healthy state is critical to assessing disease progression and to formulate any potential mitigation strategy....
The modern world has presented many threats to the health and stability of ecosystems worldwide. One of the most biodiverse ecosystems, coral reefs, faces particularly strong pressures, and is already declining rapidly in complexity and area. Although the stressors that affect reefs are diverse, ranging from nutrient pollution to overfishing,...
With mounting distrust for science, finding effective ways to educate the next generation of scientists has become increasingly important. Microbiology is a prevalent and complex subject and is at the forefront of developing cutting-edge technologies for a more in-depth look into the unseen world. However, many people are only ever...
Coastal hazards are the result of numerous physical processes cumulatively causing water levels to flood and erode the land. The waves, storm surges, tides, and run-off contributing to elevated water levels are each the product of chaotic and random weather patterns. These stochastic weather patterns dissipate energy in Earth's climate...
Propose a sampling plan to determine Hg contamination in the Nanay river basin.
The sampling plan is for a feasibility pilot, to investigate whether it is possible to safely collect samples for Hg analyses. Future studies will build on these initial results.
During applied signal-detection (e.g., airport-baggage screening) human operators can be assisted in their decision-making process by automated devices. Automation implementation is aimed at increasing performance relative to unaided levels. Generally, this intended effect is empirically observed. However, operators consistently fall short of optimal levels of aided performance, indicating suboptimal aid-use...
Phytophthora vignae, causal agent of stem and root
rot of cowpea (Vigna unguiculata), was reported for the
first time in Sri Lanka. The pathogen was found in cowpea
field soils from 3 of 5 geographic regions sampled. Only
one site however, had plants exhibiting disease symptoms.
Of the eight cowpea...
Spalting fungi show strong potential as natural colorants on a variety of materials, specifically textiles and wood. Four species of spalting fungi are currently utilized in this manner: Scytalidium cuboideum, which produces a red pigment called draconin red, Scytalidium ganodermophthorum, that produces an unknown yellow pigment, and Chlorociboria aeruginosa and...
During the 1400s – 1600s, spalted wood was an expensive commodity used in marquetry style artworks across primarily Germany and Italy. It fell out of favor during the Industrial Revolution, but is currently experiencing resurgence in popularity with US woodturners. How spalted wood is used, and what types of spalted...
Within literacy and composition studies, writing, as a
social act, is believed by many to have the potential to effect
change in and transform situations of injustice. Community literacy,
as an emergent practice within composition studies, embraces
and stretches this notion of linking literacy to social
change. Community literacy also...
Climate change and other anthropogenic impacts are threatening the existence of millions of species around the globe. On western continental boundaries, the large-scale secondary process of upwelling, which brings low pH, deoxygenated, high nutrient seawater to the surface, is compounded by climate change, that together could drive some species to...
The exponential growth of the salmonid farming industry during the last 3 decades has created conditions for massive escapes of these exotic species into natural environments in southern Chile. Here, we review and update information about salmonid escapes from 1993 to 2012 and examine their potential environmental, social, and economic...
Organizations are significantly influenced by corporate cultures of the interacting organizations. Both the construction industry and engineered wood products (EWP) manufacturing industry are generally known for operating in a traditional environment maintaining conservative corporate cultures, which can create friction when they try to interact with a more liberal architectural industry...
Myxobolus squamalis is a Myxozoan parasite of salmonids, which contributes to lowered fitness of hatchery and wild fish in the Pacific Northwest of North America. The only GenBank DNA sequence of M. squamalis is from Oncorhynchus tschawytscha (Chinook), but is not linked to a published morphological description. There is a...
Agricultural and companion animals are integral to our way of life as they provide us with nourishment, financial resources, transportation, and companionship. However, pets, managed animals in the agricultural industry, as well as wild populations of food animals are all subject to health and mortality risks. The gut microbiome is...
Objectivo: El propósito del presente estudio es analizar las inequidades socioeconómicas en la utilización de servicios de salud en el Ecuador, las inequidades en la distribución geográfica de recursos humanos en salud, y reflexionar sobre los retos de equidad que el sistema de salud ecuatoriano enfrenta en la actualidad.
Métodos:...
Cyclic nitramines are a class of compounds that include most of the commonly used explosives today. These are among the most common toxicants released into the environment as a result of human activity, generated on military ranges, battlefields, and production sites. Of these, hexahydro-1,3,5-trinitro-1,3,5- triazine (RDX) is of particular interest,...
Hatcheries are often perceived as a source of pathogen amplification, potentially increasing disease risk to free-ranging populations; at the same time, free-ranging fishes may introduce pathogens into hatcheries through untreated water sources. Many pathogens exist naturally within the environment (with the exception of introduced pathogens) and the presence of a...
Photosynthetic energy allocation strategies were investigated in the marine diatom, Thalassiosira pseudonana, grown under a wide range of light limitation. Steady-state, continuous cultures were established at three light-limited growth rates. Simultaneous measurements of photosynthetic activity were made that targeted different points in photosynthetic energy flow from gross to net photosynthesis....
Marine diseases are becoming more frequent, and tools for identifying pathogens and disease
reservoirs are needed to help prevent and mitigate epizootics. Meta-transcriptomics
provides insights into disease etiology by cataloguing and comparing sequences from suspected
pathogens. This method is a powerful approach to simultaneously evaluate both the
viral and bacterial...
Full Text:
Microbiome and
Virome in a Stranding Event
Stephanie M. Rosales*, Rebecca Vega Thurber
Oregon State
Coral reefs are in decline worldwide, and land-derived sources of pollution, including sewage, are a major force driving that deterioration. This review presents evidence that sewage discharge occurs in waters surrounding at least 104 of 112 reef geographies. Studies often refer to sewage as a single stressor. However, we show...
Despite nutrient-depleted conditions, coral reef waters harbor abundant and diverse microbes; as major agents of microbial mortality, viruses are likely to influence microbial processes in these ecosystems. However, little is known about marine viruses in these rapidly changing ecosystems. Herewe examined spatial and short-term temporal variability in marine viral abundance...
At a time of rapid global change, a socio-ecological system (SES) approach can provide a framework through which to quantify and communicate the risks and uncertainties of coupled human-natural systems. Islands, and tropical coral reef islands in particular, can be excellent models for SES research since they may be considered...
The advent of improved DNA sequencing technologies has allowed the analysis of various microbial communities. Bloom-forming freshwater cyanobacteria can produce toxins and taste-and-odor compounds that can negatively affect drinking water supplies. Here, I have employed second- and third-generation sequencing technologies to characterize bloom-forming freshwater cyanobacterial genomes and their associated heterotrophic...
Here the diversity and phylogeny of the genus, Sthereus Motschulsky, 1845, and its nearest associates in the large subfamily Molytinae are explored through molecular and morphological characters. Sanger sequencing of five genes determined that Sthereus is not monophyletic. Instead, the one species in the genus Gastrotaphrus Buchanan 1936, G. barberi...