Background:
In the Ganges Delta, chronic arsenic poisoning is a health concern affecting millions of people who rely on groundwater as their potable water source. The prevalence of anemia is also high in this region, particularly among women. Moreover, arsenic is known to affect heme synthesis and erythrocytes and the...
Porapak Q, Chromosorb 102, and Tenax GC, three porous
polymers commonly used as adsorbents in headspace analyses were
investigated. The retention times of various low-boiling compounds
relative to water were measured on the collection columns to determine
which compounds would be lost during the water removal step
employed after sampling...
Flavor profiles of canned and frozen whole kernel sweet corn were
obtained by entraining the volatile compounds on Porapak 0 traps and
by subsequent analysis on temperature-programed, 500' by 0.03" ID
capillary columns (SF-96 or Carbowax 20M). Identification was based
on GC/MS data, retention indices (I[subscript E]'s) and retention times....
The rapid worldwide emergence of the amphibian pathogen Batrachochytrium dendrobatidis (Bd) is having a profound negative impact on biodiversity. However, global research efforts are fragmented and an overarching synthesis of global infection data is lacking. Here, we provide results from a community tool for the compilation of worldwide Bd presence...
Biochar has shown promise as a soil amendment for improvement of agricultural and forest productivity, remediation of heavy metals, and sequestration of carbon, but has not yet been adopted for widespread use in any of these applications. By assessing the production potential as a carbon sequestration tool, and the stability...
Piscivory by birds can be significant, particularly on fish in small streams and during seasonal low flow when available cover from predators can be limited. Yet, how varying amounts of cover may change the extent of predation mortality from avian predators on fish is not clear. We evaluated size-selective survival...
Patterns of salmon distribution throughout a riverscape may be expected to change over time in response to environmental conditions and population sizes. Changing patterns of use, including identification of consistently occupied locations, are informative for conservation and recovery planning. We explored interannual patterns of distribution by juvenile Coho Salmon Oncorhynchus...
Some good goals for a well-managed, small-acreage horse
farm are:
• A productive pasture with plenty of grass and few weeds
• Less dust during the dry season and less mud during the wet season
• Healthy horses free of problems associated with dust, manure,
mud, and toxic plants
•...
The goals for a well-managed small-acreage horse farm are:
A productive pasture with plenty of grass and few weeds
Almost no mud during the rainy season
All nutrients (manure and stall waste) generated by the horses
recycled to feed the pasture or removed from the farm and
recycled
Healthy horses...
In a population of the European common toad Bufo bufo from a rural pond in the region of Lake Glubokoe Regional Reserve in Moscow province, Russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. We tested toads from this and...
Forest management is rapidly undergoing a transformation from a discipline based on efficient commodity production to one for multiple uses, especially on federally managed land in the United States. This new management paradigm has challenged silviculturists to develop and adapt forest management techniques that can deal with increased demands. Using...
Wildlife epidemiological outcomes can depend strongly on the composition of an ecological community, particularly when multiple host species are affected by the same pathogen. However, the relationship between host species richness and disease risk can vary with community context and with the degree of spillover transmission that occurs among co-occurring...
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infection when in
single-species groups (Fig. 1B), but treatments combining
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This dissertation uses manipulative experiments to explore amphibian-Bd infection dynamics. Although there has been almost two decades research since the discovery of Bd, many questions still remain regarding what conditions mediate chytridiomycosis virulence. My research shows how certain host and pathogen factors can influence disease virulence. Identifying how host and...
Biodiversity losses in terrestrial, freshwater, and marine systems are accelerating at a global scale and the most threatened vertebrate taxa are those associated with freshwater habitats. The causes of biodiversity losses are often complex and include synergistic effects of natural and human-induced stressors, such as habitat loss and fragmentation, urbanization,...
Biodiversity losses are occurring worldwide due to a combination of stressors. For example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. The emerging infectious disease chytridiomycosis, caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd), is a contributor to amphibian...
We examined the effects of a second-thinning harvest with alternative riparian
buffer management approaches on headwater stream habitats and associated vertebrates
in western Oregon, USA. Our analyses showed that stream reaches were generally
distinguished primarily by average width and depth, along with the percentage of the dry
reach length, and...
Flavor problems associated with the use of cheddar cheese
whey in the formulation of ice cream and other food products were
investigated. During spray drying of whey, which transforms bulky
liquid whey into an easily transportable and storable powder,
various degrees of off-flavor development may occur depending on
the care...
This dissertation presents a different approach to understanding how amphibians are responding to disease through ontogeny. Although numerous efforts have been conducted to understand host responses to the fungus Batrachochytrium dendrobatidis (Bd), studies have been restricted to distinct developmental stages. This dissertation provides information on host response to Bd across...
I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in...
We manipulated food inputs among patches within experimental streams to determine how variation in foraging behavior influenced demographic and phenotypic responses of juvenile steelhead trout (Oncorhynchus mykiss) to the spatial predictability of food resources. Demographic responses included compensatory adjustments in fish abundance, mean fish size, and size inequality. These responses...
The presence in rat liver microsomes of an enzyme system
which demethylates N-methylhydrazines and azo compounds to formaldehyde
has been reported. Some of the compounds found to be
substrates were monomethylhydrazine, N-isopropyl-α-(2-methylhydrazino)-
p-toluamide and the azo derivative of the latter hydrazine. This
enzyme can be classified as a mixed function...
The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the...
Animals can be naturally exposed simultaneously to multiple stressors. These include habitat changes, contaminants, diseases, invasive species, parasitism, and predation. Exposure to various combinations of biotic and abiotic stressors may induce behavioral changes that affect the way an individual interacts within its environment.Like other groups of organisms, amphibians are exposed...
Anthropogenic and natural stressors often interact to affect organisms. Amphibian populations are undergoing unprecedented declines and extinctions with pesticides and emerging infectious diseases implicated as causal factors. Although these factors often co-occur, their effects on amphibians are usually examined in isolation. We hypothesized that exposure of larval and metamorphic amphibians...
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. On
9 April, we added 25 g of rabbit chow and 300 g of dry leaves (primarily Quercus spp.) to each
from the summer dry season to the winter wet season. Such movement that connects summer and winter habitats may be particularly important for coho salmon, O. kisutch, because availability of overwintering habitat can limit freshwater survival for this species. Here, I describe basin-scale variability in the spatial pattern of fall...
Debris flows, common disturbances in many mountainous areas, initially scour or bury stream habitats; however, debris flows deliver vast amounts of wood, boulders, and gravel that may ultimately form complex stream habitat to potentially support a diverse salmonid assemblage. The materials deposited by debris flows would otherwise be inaccessible to...
The evolution and maintenance of multiple phenotypes within populations is an interesting evolutionary and ecological question, and is becoming increasingly important for the restoration and conservation of partially migratory species. In particular, why individuals adopt a particular phenotype has been the focus of numerous research efforts. In the partially migratory...
Species declines and extinctions have been recorded across taxa as evidence of an ongoing global biodiversity crisis. Amphibians are at the forefront of these declines with nearly one third of amphibian species estimated to be at risk of extinction. While many factors contribute to population declines and extinctions, the role...
Earth is experiencing unprecedented biodiversity loss. Amphibians are at the forefront of this biodiversity loss, with species declines estimated to be more severe than those of birds and mammals. Amphibian population declines and extinctions are driven by a number of factors including climate change, habitat destruction, contaminants and disease but...
Studies of the effects of forest harvest on streams and fish have a long history in the Pacific Northwest. Results of this work have prompted development of new forest harvest practices that are more protective of these resources, but the effectiveness of these new practices has not been fully evaluated....
Research conducted on humpback whitefish Coregonus pidschian in the Copper River Delta, Alaska has revealed a complex life history involving seasonal migrations and the occupation of a variety of freshwater and marine habitats including lacustrine, riverine, estuarine, and marine. Forty-five whitefish were tagged with radio transmitters in 2006 and 2007,...
Associations between occupancy patterns of a montane anuran species, Rana cascadae, and habitat structure at multiple scales were examined to investigate how population structure may influence persistence in spatially and temporally heterogeneous environments. Predictions were based on population dynamics suggested by source-sink and metapopulation models. Potential sites in three basins...
Biological invasions create complex ecological
and societal issues worldwide. Most of the
knowledge about invasions comes only from successful
invaders, but less is known about which processes
determine the differential success of invasions. In this
review, we develop a framework to identify the main
dimensions driving the success and failure...
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and hypotheses
Arismendi, I., Penaluna, B. E., Dunham, J. B., de Leaniz, C. G., Soto, D., Fleming,
I
Land use and climate change occur simultaneously around the globe. Fully understanding their separate and combined effects requires a mechanistic understanding at the local scale where their effects are ultimately realized. Here we applied an individual-based model of fish population dynamics to evaluate the role of local stream variability in...
Large river basins integrate the signal of water from atmospheres to oceans. Climate change is widely expected to alter streamflow and potentially disrupt water management systems. We tested the ecological resilience -- capacity of headwater ecosystems to sustain streamflow under climate change – and the engineering resilience – capacity of...
Severe scouring from splash damming was one of the earliest reported forms of widespread anthropogenic disturbance in streams of the Pacific Northwest, USA. Splash damming was a common method of log transport in western Oregon from the 1880s through the 1950s. Before being released in large freshets to downstream lumber...
Because forest ecosystems have the capacity to store large quantities of carbon
(C), there is interest in managing forests to mitigate elevated CO[subscript 2] concentrations and
associated effects on the global climate. However, some mitigation techniques may contrast
with management strategies for other goals, such as maintaining and restoring biodiversity....
This compilation of theses and dissertations (a part of the OSU Bibliographic Series) for the period 1970-1977 reflects this university's emphasis on research and graduate study. It may be viewed as an indicator of the contributions made to the state of Oregon through graduate study and research at Oregon State...
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H O W T O U S E T H I S G U I D E
CONTENTS
Subject Fields:
Included in this list are the
masters
Forested riparian buffer zones are used in conjunction with upland forest management, in part, to provide for the recruitment for large wood to streams. Small headwater streams account for the majority of stream networks in many forested regions. Yet, our understanding of how riparian buffer width influences wood dynamics in...
The ongoing worldwide loss of biodiversity has been described as a "biodiversity crisis," "the Anthropocene defaunation," and alternatively "an extinction spasm." More recently, many scientists have come to the conclusion that we are witnesses to Earth's sixth major mass extinction event, which has the potential to fundamentally alter basic ecological...
In partially migratory species, such as Oncorhynchus mykiss, the emergence of life history phenotypes is often attributed
to fitness trade-offs associated with growth and survival. Fitness trade-offs can be linked to reproductive tactics that vary between
the sexes, as well as the influence of environmental conditions. We found that O....
We compiled Western Pond Turtle (Actinemys marmorata) and Painted Turtle (Chrysemys picta) locations in northwestern North America, consolidating data from multiple sources including nine U.S. State and Canadian Provincial jurisdictions. We assessed numbers of discrete locations, and analyzed distribution patterns temporally and spatially. Western Pond Turtle observation records ranged from...
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DEFINITIONS…………………………………………………………...44
APPENDIX G. BRUCE BURY SUGGESTIONS TO DATASET………………………………………….56
We examined terrestrial amphibians in managed headwater forest stands in western Oregon from 1998 to 2009. We assessed: (1) temporal and spatial patterns of species capture rates, and movement patterns with distance from streams and forest management treatments of alternative riparian buffer widths and upland thinning; (2) species survival and...
Explosively 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...
Despite its importance to biodiversity and ecosystem function, patterns and drivers of regional scale variation in forest structure and development are poorly understood. We characterize structural variation, create a hierarchical classification of forest structure, and develop an empirically based framework for conceptualizing structural development from 11,091 plots across 25 million...
Emerging infectious diseases impact both human and wildlife populations. Infectious agents, in particular the aquatic fungus Batrachochytrium dendrobatidis (chytrid), have an influential role in driving global amphibian population declines. The emergence of the chytrid fungus has aspects of both geographic spread as well as climate shifts altering environmental conditions and...
Emerging infectious diseases are increasing globally and are a threat to human, wildlife, and ecosystem health. The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), or amphibian chytrid fungus, is associated with worldwide amphibian population declines and extinctions. Bd has been found on every continent where amphibians exist and has been documented...
Water temperature is an important measure of water quality, as well as a dominant factor affecting aquatic life within the stream environment. Elevated water temperatures can decrease the survival rate of fish in each life stage. Cold water species, such as salmonids, are particularly susceptible to elevated water temperatures. For...
This study examined the distribution and behavior of adult spring chinook salmon
(Oncorhynchus tshawytscha) related to patterns of stream temperature and physical
habitat at channel unit, reach, and basin-wide spatial scales in both a wilderness stream
and a disturbed stream in the John Day River basin in northeastern Oregon. Thermal...