177 research outputs found

    Remediating effects of human threats on lotic fish assemblages within the Missouri River basin : how effective are conservation practices

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    Title from PDF of title page (University of Missouri--Columbia, viewed on October 26, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisors: Drs. Scott P. Sowa and David L. GalatIncludes bibliographical references.Vita.Ph. D. University of Missouri--Columbia 2012."July 2012"To develop tools that can improve agricultural conservation, I: 1) assessed total watershed condition and where agricultural conservation practices (CPs) are likely to be effective (hereafter primary management capacity) of stream segments in Missouri River basin by conducting a threat assessment, 2) assessed agricultural soil CP effectiveness, and 3) developed a decision support framework to improve strategic conservation planning. Agricultural threats were the most prevalent source of potential ecological stress, and 60% of stream segments were classified as under primary management capacity of U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS). Modeled relationships among NRCS soil CPs and fish guild abundance indicate CPs have the potential to reduce impacts of agricultural sources of stream sedimentation. Applied NRCS soil CPs were predicted to improve fish assemblage condition in 2% of evaluated watersheds and additional CPs were needed to improve fish assemblage condition in up to 11 and 17% of stream segments in evaluated ecoregions. The decision support framework was used in a case study to identify a subset of watersheds with degraded fish assemblages under NRCS primary management capacity. In these 2,633 watersheds, I estimated the amount and cost of CPs required to meet ecological objectives so that managers can make strategic conservation decisions and appropriately allocate conservation resources.Includes bibliographical reference

    Airborne Radar Interferometric Repeat-Pass Processing

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    Earth science research often requires crustal deformation measurements at a variety of time scales, from seconds to decades. Although satellites have been used for repeat-track interferometric (RTI) synthetic-aperture-radar (SAR) mapping for close to 20 years, RTI is much more difficult to implement from an airborne platform owing to the irregular trajectory of the aircraft compared with microwave imaging radar wavelengths. Two basic requirements for robust airborne repeat-pass radar interferometry include the ability to fly the platform to a desired trajectory within a narrow tube and the ability to have the radar beam pointed in a desired direction to a fraction of a beam width. Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is equipped with a precision auto pilot developed by NASA Dryden that allows the platform, a Gulfstream III, to nominally fly within a 5 m diameter tube and with an electronically scanned antenna to position the radar beam to a fraction of a beam width based on INU (inertial navigation unit) attitude angle measurements

    The effects of implementing recitation activities on success rates in a college calculus course

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    Over a period of six years, three different types of recitation sessions were implemented into the large enrollment section of a college calculus course. During the fall semesters, the results on the departmental final examination, the DFW rates, and the one-year retention rates of students as STEM majors were examined by the type of recitation session used with the large enrollment section. The three types of recitation sessions studied were: (1) optional mentoring sessions at the Math Assistance Center conducted by undergraduate students (peer mentors), (2) required mentoring sessions conducted by graduate students, and (3) required VGNA (Verbal, Graphical or Geometric, Numeric, and Algebraic) Concept activities, which were also coupled with mentoring sessions conducted by graduate students. The success of the students in the large enrollment section of the course, which included one of the three different types of recitation sessions, was compared to the success of students in the small enrollment sections of the course (enrollments less than 50 students). The effects of using each type of recitation session on raising departmental final examination scores, lowering DFW rates, and raising one-year retention rates is presented. The results of this study demonstrate methods of raising student success rates in large enrollment (lecture-format) courses

    Citizen science for observing and understanding the Earth

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    Citizen Science, or the participation of non-professional scientists in a scientific project, has a long history—in many ways, the modern scientific revolution is thanks to the effort of citizen scientists. Like science itself, citizen science is influenced by technological and societal advances, such as the rapid increase in levels of education during the latter part of the twentieth century, or the very recent growth of the bidirectional social web (Web 2.0), cloud services and smartphones. These transitions have ushered in, over the past decade, a rapid growth in the involvement of many millions of people in data collection and analysis of information as part of scientific projects. This chapter provides an overview of the field of citizen science and its contribution to the observation of the Earth, often not through remote sensing but a much closer relationship with the local environment. The chapter suggests that, together with remote Earth Observations, citizen science can play a critical role in understanding and addressing local and global challenges

    Schools, teachers, and curriculum change: A balancing act?

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    Educational change is a fact of life for teachers across the world, as schools are subjected to constant and ubiquitous pressures to innovate. And, yet, many school practices remain remarkably persistent in the face of such innovation. This paradox of innovation without change is perplexing for policymakers and practitioners alike. This paper investigates the gap between policy and practice, between innovation and the changes in social practices that occur in response to such innovation. It draws upon empirical data from two case studies in Scotland — schools responding to new curriculum policy—exploring contrasting approaches to the management of innovation. One is a laissez faire approach, and the other a more directive managerial strategy. Through an analytical separation of culture, structure, and agency, derived from the social theory of Margaret Archer, the paper sheds light on the social processes that accompanied innovation in these two settings demonstrating how teacher culture and differing management styles impact upon externally initiated policy

    Intracellular SERS nanoprobes for distinction of different neuronal cell types.

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    Distinction between closely related and morphologically similar cells is difficult by conventional methods especially without labeling. Using nuclear-targeted gold nanoparticles (AuNPs) as intracellular probes we demonstrate the ability to distinguish between progenitor and differentiated cell types in a human neuroblastoma cell line using surface-enhanced Raman spectroscopy (SERS). SERS spectra from the whole cell area as well as only the nucleus were analyzed using principal component analysis that allowed unambiguous distinction of the different cell types. SERS spectra from the nuclear region showed the developments during cellular differentiation by identifying an increase in DNA/RNA ratio and proteins transcribed. Our approach using nuclear-targeted AuNPs and SERS imaging provides label-free and noninvasive characterization that can play a vital role in identifying cell types in biomedical stem cell research

    On the use of parataxonomy in biodiversity monitoring: a case study on wild flora

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    International audienceMonitoring programs that assess species-richness and turnover are now regarded as essential to document biodiversity loss worldwide. Implementation of such programs is impeded by a general decrease in the number of skilled naturalists. Here we studied how morphotypes, instead of species, might be used by unskilled participants (referred to as “volunteers”) to survey common plant communities. Our main questions were: (1) Can morphotypes be used as a robust estimator of species-richness (alpha-diversity) and assemblage turnover (Beta-diversity)? and (2) What is the robustness (reproducibility and repeatability) of such methods? Double inventories were performed on 150 plots in arable Weld margins, one by a non-expert using morphotypes, the other by a taxonomist using species. To test the robustness of morphotype identiWcation among participants, 20 additional plots were surveyed by eight volunteers using the same protocol. We showed that (1) the number of morphotypes identiWed by unskilled volunteers in a plot was always strongly correlated with species-richness. (2) Morphotypes were sensitive to diVerences among habitats but were less accurate than species to detect these diVerences. (3) Morphotype identiWcation varied signiWcantly within and between volunteers. Due to this lack of repeatability and reproducibility, parataxonomy cannot be considered a good surrogate for taxonomy. Nevertheless, assuming that morphotypes are identiWed with standardized methods, and that results are used only to evaluate gross species-richness but not species turnover, parataxonomy might be a valuable tool for rapid biodiversity assessment of common wild flora
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