7,234 research outputs found
Application of Molecular Pathology Techniques to Understand Mechanisms of Disease in Smallmouth Bass
In the Chesapeake Bay drainage, smallmouth bass Micropterus dolomieu are used as an indicator species of estrogenic contaminant exposure and have been implicated in fish kills and disease since 2005. In the Potomac River drainage, adult smallmouth bass have experienced mortality and disease and males have a high prevalence of intersex (testicular oocytes). Conversely, in the Susquehanna River drainage mortalities and disease of young-of-the-year smallmouth bass (YOY SMB) have occurred and resulted in a population shift to older and larger fish. The exact cause of these events remains unknown; however, factors such as poor water quality, contaminants, pathogens and parasites, increased temperatures, and nutrification have been assessed. In order to address this issue, the USGS Fish Health Branch, Leetown Science Center, and West Virginia Cooperative Fish and Wildlife Research Unit have ongoing assessment and monitoring projects throughout the Chesapeake Bay watershed. The use of routine histopathology has provided guidance for further research with molecular endpoints that may help explain the mechanisms involved in disease in smallmouth bass. The purpose of this dissertation research was to: 1.) Identify the prevalence of coinfections and risk factors of disease in YOY SMB; 2.) Use in situ hybridization to identify coinfections of bacteria with the myxozoan parasite Myxobolus inornatus in YOY smallmouth bass; 3.) Model liver helminths and coinfections of YOY SMB with land use at two spatial scales; 4.) Develop laser capture microdissection methods for nucleic acid extractions which could be used with smallmouth bass tissues; and 5.) Utilize Next-Generation Sequencing to develop a partial testes transcriptome to identify molecular markers that may help explain intersex development in male smallmouth bass
Quality Comparison of Vegetables Dehydrated in Solar Drier and Electrical Oven
Ascorbic acid, sugars, dehydration ratio and moisture were determined in the vegetables dehydrated separately in solar drier and in electrical oven under similar conditions by standard methods. Vegetables examined were cabbage, cauliflower, tomato, radish, turnip, lahi, methi and palak. It was revealed that in each case, contents of ascorbic acid were higher in solar-dried vegetables in comparison to oven-dried stuffs. This finding indicated superiority of solar driers over electrical ovens, both in reference to quality of the dehydrated vegetables and its overall cost of operation
A Complete Set of VSOP Observations of 3C279
We have compiled a complete set of VSOP observations of 3C279, consisting of eight 5 GHz, and six 1.6 GHz, VSOP observations, all of which include the VLBA in the ground array. We are using the data-set to determine brightness temperature limits from model-fits to the visibilities, the transverse structure of the jet over its first 20 milliarcseconds, and parsec-scale spectral index maps
Photophysics of 9-aminoacridinium hydrochloride
The steady state and time domain spectroscopy of 9-aminoacridinium hydrochloride have been studied. 9-aminoacridine (I), 9-aminoacridinium (II) and the double protonated ion (III) follow Waterman's principle with respect to their spectra and lifetimes. It is established that the excimer formation in (II) is from the ground state dimers which undergo either thermally-activated radiationless excimer conversion or a geometrical rearrangement in the excited state at room temperature. The quenching of monomer emission by dimers or foreign quenchers (KI) is found to be of transient nature as suggested by the continuum model
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