The invasion of silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) or "bigheaded carps" has caused extensive ecological and economic harm throughout the Mississippi River and its tributaries. To prevent their continued spread upstream toward the Great Lakes, intense commercial harvest was implemented on the Illinois River, a large tributary that connects the Mississippi River to Lake Michigan.
View Article and Find Full Text PDFUnderstanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences from existing efforts. In this paper, we use a common analytical framework to analyze data from five disparate fish monitoring programs to better understand the nature of spatial and temporal trends in large river fish assemblages.
View Article and Find Full Text PDFBivalve shells provide an unparalleled opportunity for understanding the history of bioavailable trace elements in aquatic systems. The present study analyzed the elements Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn in freshwater mussel shells collected from a large floodplain river. Shells were collected fresh, sampled from a historic archive, and retrieved from pre-Columbian archeological sites.
View Article and Find Full Text PDFIn the Mississippi River Basin of North America, invasive bigheaded carp (silver carp and bighead carp , also referred to as Asian carp) have spread rapidly over the past several decades. In the Illinois River, an important tributary of the Upper Mississippi River, reproduction appears to be sporadic and frequently unsuccessful, yet bigheaded carp densities in this river are among the highest recorded on the continent. Understanding the causative factors behind erratic recruitment in this commercially-harvested invasive species is important for both limiting their spread and managing their harvest.
View Article and Find Full Text PDFThe Illinois River was substantially altered during the 20th century with the installation of navigational locks and dams, construction of extensive levee networks, and degradation of water quality. Freshwater mussels were affected by these changes. We used sclerochronology and stable isotopes to evaluate changes over time in age-and-growth and food sources for two mussel species: Amblema plicata and Quadrula quadrula.
View Article and Find Full Text PDFObjective: To investigate the feasibility of using high-intensity focused ultrasound (HIFU), under dual-mode ultrasound arrays (DMUAs) guidance, to induce localized thermal damage inside ovaries without damage to the ovarian surface.
Design: Laboratory feasibility study.
Setting: University-based laboratory.
IEEE Trans Biomed Eng
October 2013
A real-time dual-mode ultrasound array (DMUA) system for imaging and therapy is described. The system utilizes a concave (40-mm radius of curvature) 3.5 MHz, 32 element array, and modular multichannel transmitter/receiver.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
January 2012
Annu Int Conf IEEE Eng Med Biol Soc
April 2010
We present experimental results illustrating the unique advantages of dual-mode array (DMUA) systems in monitoring and guidance of high intensity focused ultrasound (HIFU) lesion formation. DMUAs offer a unique paradigm in image-guided surgery; one in which images obtained using the same therapeutic transducer provide feedback for: 1) refocusing the array in the presence of strongly scattering objects, e.g.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
January 2010
We present experimental validation results of an adaptive, image-based refocusing algorithm of dual-mode ultrasound arrays (DMUAs) in the presence of strongly scattering objects. This study is motivated by the need to develop noninvasive techniques for therapeutic targeting of tumors seated in organs where the therapeutic beam is partially obstructed by the ribcage, e.g.
View Article and Find Full Text PDFHyaluronidases are a family of endolytic glycoside hydrolases that cleave the beta1-4 linkage between N-acetylglucosamine and glucuronic acid in hyaluronan polymers via a substrate-assisted mechanism. In humans, turnover of hyaluronan by this enzyme family is critical for normal extracellular matrix remodeling. However, elevated expression of the Hyal1 isozyme accelerates tumor growth and metastatic progression.
View Article and Find Full Text PDFAnalyses of stable isotope (δC and δN) and C:N ratios of food webs within a floodplain and a constricted-channel region of the Ohio River during October 1993 and July 1994 indicate that the increasingly influential flood pulse concept (FPC) does not, for either location, adequately address food web structure for this very large river. Furthermore, results of this study suggest that the riverine productivity model (RPM) is more appropriate than the widely known river continuum concept (RCC) for the constricted region of this river. These␣conclusions are based on stable isotope analyses of potential sources of organic matter (riparian C trees, riparian C grasses and agricultural crops, submerged macrophytes, benthic filamentous algae, benthic particulate organic matter, and transported organic matter containing detritus and phytoplankton) and various functional feeding groups of invertebrate and fish consumers.
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