2,281 research outputs found

    Youā€™re the Expert! A participatory approach tonitrate pollution research in Central Montana

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    Participatory approaches to water resources research are intended to promote sustainable behaviors and management of complex problems. The goal of this research is to improve BMP adoption through producer participation in the research process

    A Paleoecological Test of a Classical Hydrosere in the Lake Michigan Dunes

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    Aquatic vegetation varies along a chronosequence of dune ponds at Miller Woods, Indiana Dunes National Lakeshore. Submersed and floating-leaved macrophytes dominate the vegetation of the youngest ponds. Older ponds contain mixed assemblages of submersed, floating-leaved, and emergent plant taxa. The oldest ponds are dominated by emergent plants, especially Typha angustifolia. We conducted paleoecological studies at one of the oldest ponds to test the hypothesis that the modern vegetational array along the pond chronosequence represents a hydrarch successional sequence. Macrofossil stratigraphy of the 3000-yr-old pond indicates no significant changes in pond vegetation following early colonization until \u3c 150 BP. Pond vegetation before 150 BP consisted of a diverse assemblage of submersed, floating-leaved, and emergent macrophyte taxa. Pollen and macrofossil data indicate a major, rapid vegetational change at \u3c150 BP, evidently in response to local human disturbance. Pollen data reveal that the extensive Typha stands in the older ponds have developed recently, following postsettlement disturbance. Modern vegetational differences along the chronosequence reflect differential effects of disturbance rather than autogenic hydrarch succession. This study illustrates a major pitfall in inferring successional trends from spatial sequences of vegetation

    Logan City CurbsideRecycling Program Phase III Results

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    This report summarizes the results of a series of survey research projects examining the attitudes and behaviors of Cache County residents regarding recycling programs in 2005. USU researchers were contacted by the Cache County Service District #1, through the Logan Environmental Department, to update information about household recycling attitudes and behaviors, and to present results to various audiences as part of the long-range county solid waste master planning process

    The music of the Vietnam War

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    Slides for a presentation on popular songs associated with the Vietnam War

    Differentiating Climatic And Successional Influences On Long-Term Development Of A Marsh

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    Comparison of long-term records of local wetland vegetation dynamics with regional, climate-forced terrestrial vegetation changes can be used to differentiate the rates and effects of autogenic successional processes and allogenic environmental change on wetland vegetation dynamics. We studied Holocene plant macrofossil and pollen sequences from Portage Marsh, a shallow, 18-ha marsh in northeastern Indiana. Between 10 000 and 5700 yr BP the basin was occupied by a shallow, open lake, while upland vegetation consisted of mesic forests of Pinus, Quercus, Ulmus, and Carya. At 5700 yr BP the open lake was replaced rapidly by a shallow marsh, while simultaneously Quercus savanna developed on the surrounding uplands. The marsh was characterized by periodic drawdowns, and the uplands by periodic fires. Species composition of the marsh underwent further changes between 3000 and 2000 yr BP. Upland pollen spectra at Portage Marsh and other sites in the region shifted towards more mesic vegetation during that period. The consistency and temporal correspondence between the changes in upland vegetation and marsh vegetation indicate that the major vegetational changes in the marsh during the Holocene resulted from hydrologic changes forced by regional climate change. Progressive shallowing of the basin by autogenic accumulation of organic sediment constrained vegetational responses to climate change but did not serve as the direct mechanism of change

    Cache CountyCommunity Survey of Future Landfill Alternatives

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    State University in the spring of 2003. The purpose of this survey was to gather scientific information regarding the concerns, perceptions, and preferences of Cache County adults related to various future landfill siting options. The survey was conducted at the request of local officials, the Countywide Service District, and various advisory committees established to make recommendations on a future Cache County landfill site

    ReducingGroundwater Nitrate in the Judith River Watershed: A Participatory Approach to AchieveEffective Management for Improved Water Quality

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    Rising levels of nitrate in groundwater threaten human health and downstream ecosystems. In the Judith River Watershed, Montana, groundwater nitrate concentrations frequently exceed 10 mg L-Ā­ā€1, and may be increasing due to agricultural practices on thin soils overlying shallow, unconfined aquifers with short groundwater residence :mes. Previous extension and research ac:vi:es in the watershed have provided key data and established working relationships with local stakeholders, but adoption rates of water quality best management practices (BMPs) have been low. With this project, we undertake a participatory approach that engages agricultural producers and stakeholders to

    Gate Coupling to Nanoscale Electronics

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    The realization of single-molecule electronic devices, in which a nanometer-scale molecule is connected to macroscopic leads, requires the reproducible production of highly ordered nanoscale gaps in which a molecule of interest is electrostatically coupled to nearby gate electrodes. Understanding how the molecule-gate coupling depends on key parameters is crucial for the development of high-performance devices. Here we directly address this, presenting two- and three-dimensional finite-element electrostatic simulations of the electrode geometries formed using emerging fabrication techniques. We quantify the gate coupling intrinsic to these devices, exploring the roles of parameters believed to be relevant to such devices. These include the thickness and nature of the dielectric used, and the gate screening due to different device geometries. On the single-molecule (~1nm) scale, we find that device geometry plays a greater role in the gate coupling than the dielectric constant or the thickness of the insulator. Compared to the typical uniform nanogap electrode geometry envisioned, we find that non-uniform tapered electrodes yield a significant three orders of magnitude improvement in gate coupling. We also find that in the tapered geometry the polarizability of a molecular channel works to enhance the gate coupling

    Regional variation in the flexural properties of the equine hoof wall

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    The equine hoof wall is a hard, keratinous structure that transmits forces generated when the hoof connects the ground to the skeleton of the horse. During locomotion the hoof capsule is known to deform, resulting in an inward curvature of the dorsal wall and expansion of the heels. However, while researchers have studied the tensile and compressive properties, there is a lack of data on the flexural properties of the hoof wall in different locations around the hoof capsule. In this study, the flexural properties and hydration status of the hoof wall were investigated in two orthogonal directions, in different locations around the hoof capsule. The hoof was divided into three regions: the dorsal-most aspect (toe), the medial and lateral regions (quarters) and the heels caudally. Beams were cut both perpendicular (transverse) and parallel (longitudinal) to the orientation of the tubules. Differences in the mechanical properties were then investigated using three-point bending tests. There were considerable differences in the flexural properties around the hoof capsule; transverse beams from the heel were 45% more compliant than those from the toe region. This corresponded with changes in the hydration of the hoof wall; beams from the heel region were more hydrated (28.2 Ā± 0.60%) than those from the toe (24.2 Ā± 0.44%; P < 0.01). Regional variation in the water content is thought to help explain differences in the flexural properties. Mechanical data are further discussed in relation to variation in the structure and loading of the hoof wall
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