Managing cattle to disseminate seeds of desirable plants, or alternatively, to restrict weed seed contamination on rangelands is of interest to managers. Four experiments were conducted to determine effects of ruminant digestion on germination of ingested seeds. A number of plant species representing a variety of seed size and seed...
Yellow starthistle (Centaurea solstitialis L.) is an introduced Asteraceae that has become established on 10 million acres in the Pacific Northwest and California. This weed functions as an annual or short-lived perennial and depends on seeds for reproduction. Strategies of control that reduce plant fitness or lower seed production or...
Pre-spawning mortality (PSM) presents a major problem for population recovery of spring Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River basin. In certain reaches and years, PSM has exceeded 90%. Histology has been used as the primary diagnostic method to investigate PSM in the Chinook Salmon, and a collection of...
Pseudoloma neurophilia is the most common pathogen reported in zebrafish (Danio rerio) research facilities and is an important threat to the zebrafish model. This microsporidian parasite can cause clinical disease, but more importantly is a causative agent of non-protocol induced variation in research. Studies utilizing infected zebrafish, could potentially confound...
As the zebrafish (Danio rerio) becomes increasingly popular as a biomedical model for various laboratory studies, the need for efficient and accurate diagnostic assays for the pathogens that infect it has grown. The most common pathogen infecting laboratory zebrafish is Pseudoloma neurophilia, a microsporidium that has been known to cause...
Zebrafish (Danio rerio) are one of the most commonly used animal models in biomedical research. Zebrafish resource facilities, like the Zebrafish International Resource Center (ZIRC) in Eugene, Oregon, are the main providers and keepers of numerous zebrafish wild-type, mutant, and transgenic lines. Although ZIRC maintains live zebrafish at various life...
Since its inception as a laboratory animal in the early 1970s, the zebrafish has proven itself a rising star in the world of comparative biomedical sciences due to its short generation time, ease of care, external fertilization, and transparent larvae. In a very few decades, the zebrafish has been utilized...
As pre-spawning mortality (PSM) in Chinook salmon in the Willamette River Valley becomes a more defined and examined area of study, more focus is granted to not only preserving the health of these fish, but also expanding knowledge concerning various pathogens that utilize the salmon as hosts and may be...
As a major biological model for biomedical research, maintaining healthy
zebrafish (Danio rerio) is imperative for accurate and consistent lab results. This
retrospective study focuses on Pseudoloma neurophilia, a microsporidium, because it is
the most common pathogen found in laboratory zebrafish. An online database maintained
by the Zebrafish International Resource...
The microsporidian parasite, Pseudoloma neurophilia, is the most commonly diagnosed infectious disease in laboratory populations of the zebrafish, Danio rerio. Infections by P. neurophilia are generally subclinical, however, they can become acute either incidentally or due to experimental immune suppression. Non-protocol induced variation can confound results in laboratory experiments using...
Zebrafish (Danio rerio) have become an increasingly important model organism for cancer research. There are several cancer models in which neoplasms are induced chemically or genetically. However, spontaneous (unknown etiology) neoplasms are rather common in zebrafish, particularly in older fish. For over a decade, spontaneous intestinal neoplasia and preneoplastic intestinal...
Mycobacteriosis is a common disease of laboratory zebrafish (Danio rerio). Different infection patterns occur in zebrafish depending on mycobacterial species. Mycobacterium marinum and M. haemophilum produce virulent infections associated with high mortality, whereas M. chelonae is more wide spread and not associated with high mortality. Identification of mycobacterial infections to...
Relationships among myxozoan parasites of the order Multivalvulida were examined through comparative DNA sequence analysis. Members of this group of parasites is known for the damaging effects they have on their fish hosts, especially commercially important species. Most species infect muscle, where they form cysts and many release proteolytic enzymes....
As highlighted in this study, shallow-water habitats and the prey they provide are important for juvenile salmon in the Columbia River estuary, but the spread of invasive species and large-scale changes to the estuary influence how these habitats are utilized. Reed canarygrass (Phalaris arundinacea) (“PHAR” hereafter) is a highly invasive...
Intensive management of young-growth Douglas-fir plantations has emphasized volume growth over wood quality. A better understanding of the variables that affect wood quality is needed so that wood quality and stand yield can be systematically combined into a silviculture program. This experiment utilized two separate experiments to establish the relationship...
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...
It is the hope and expectation of many specialists in the area of linear programming that a major improvement in solution techniques for handling large-scale models with thousands of constraints will be developed in the near future. Although the present state of the art for solving linear programs is still...
Amphibian biodiversity is in rapid global decline, due in part to the fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Susceptibility to Bd and chytridiomycosis varies between species and populations. Skin peptides and symbiotic skin bacteria appear to be important mechanisms of Bd resistance. However, not much is known about...
Two tributaries of the south fork of the Burnt River, near Unity Oregon were studied
during the summers of 2000 and 2001 to determine water heating and cooling
patterns. Hourly temperature data were recorded for air, water, and soil parameters
at four elevations 150m apart on Barney and Stevens Creeks....
Sea otters fulfill a keystone role in several Northeastern Pacific nearshore ecosystems. However, their influence has been absent in Oregon coastal waters since their extirpation in the 19th and early 20th century. Interest has been growing for a translocation attempt to reintroduce sea otters to Oregon from one or more...