Open Access. Powered by Scholars. Published by Universities.®

Other Environmental Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

4,500 Full-Text Articles 12,615 Authors 2,235,768 Downloads 141 Institutions

All Articles in Other Environmental Sciences

Faceted Search

4,500 full-text articles. Page 41 of 183.

Irrigation’S Impact On A Precipitation Event During Grainex In Nebraska, Usa, Daniel Whitesel 2022 University of Nebraska-Lincoln

Irrigation’S Impact On A Precipitation Event During Grainex In Nebraska, Usa, Daniel Whitesel

School of Natural Resources: Dissertations, Theses, and Student Research

Numerous precipitation events were observed during the Great Plains Irrigation Experiment (GRAINEX). However, the precipitation event that was observed the morning of 23 July 2018 is the focus of this thesis. Six experiments were conducted which involved increasing or decreasing soil moisture by 5% increments over the irrigated cropland. An additional experiment, which changed the irrigated land use to grassland, showed precipitation increases. It was found that regardless of strength of irrigation, average precipitation decreased. Average precipitation decreased by up to 72% when irrigation increased compared to the control simulation and decreased by up to 85% when irrigation decreased compared …


Adaptation, Transformation And Resilience In Healthcare Comment On “Government Actions And Their Relation To Resilience In Healthcare During The Covid-19 Pandemic In New South Wales, Australia And Ontario, Canada”, David G. Angeler, Harris A. Eyre, Michael Berk, Craig R. Allen, William Hynes, Igor Linkov 2022 Swedish Univer, The PRODEO Institutesity of Agricultural Sciences, Deakin University

Adaptation, Transformation And Resilience In Healthcare Comment On “Government Actions And Their Relation To Resilience In Healthcare During The Covid-19 Pandemic In New South Wales, Australia And Ontario, Canada”, David G. Angeler, Harris A. Eyre, Michael Berk, Craig R. Allen, William Hynes, Igor Linkov

School of Natural Resources: Faculty Publications

Adaptive capacity is a critical component of building resilience in healthcare (RiH). Adaptive capacity comprises the ability of a system to cope with and adapt to disturbances. However, “shocks,” such as the current coronavirus disease 2019 (COVID-19) pandemic, can potentially exceed critical adaptation thresholds and lead to systemic collapse. To effectively manage healthcare systems during periods of crises, both adaptive and transformative changes are necessary. This commentary discusses adaptation and transformation as two complementary, integral components of resilience and applies them to healthcare. We treat resilience as an emergent property of complex systems that accounts for multiple, often disparately distinct …


The Economics Of Residential Solar Panels: A Comparison Of Energy Charges For Different Load Profiles, Rate Plans, And Panel Orientations, John B. Broughton, Candace E. Ybarra, Prashanth U. Nyer 2022 Chapman University

The Economics Of Residential Solar Panels: A Comparison Of Energy Charges For Different Load Profiles, Rate Plans, And Panel Orientations, John B. Broughton, Candace E. Ybarra, Prashanth U. Nyer

Business Faculty Articles and Research

This paper examines the effect of different residential electrical load profiles (electrical energy consumption patterns within a day) on energy charges for customers with solar panels under different Southern California Edison time-of-use (TOU) rate plans. We identify the TOU plan which would be the most cost effective for solar customers with each load profile. The impact of the orientation of the solar panel array (whether it faces south or west or east) and shading patterns on electricity charges are examined. We also determine the ideal usage offset (the percentage of electricity consumption provided by the solar array) for the various …


Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin 2022 Texas A&M University

Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin

United States Geological Survey: Staff Publications

Background: Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub (Macrhybopsis australis) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpose of this study was to test competing ecological theories for prairie chub movement, including the colonization cycle hypothesis (CCH) that posits adults must make upstream movements to compensate for downstream drift at early life stages, and the restricted movement paradigm (RMP) that describes populations as heterogeneous mixes of mostly stationary …


A Review Of The Impacts Of Invasive Wild Pigs On Native Vertebrates, Matthew T. McDonough, Stephen S. Ditchkoff, Mark D. Smith, Kurt C. Vercauteren 2022 Auburn University

A Review Of The Impacts Of Invasive Wild Pigs On Native Vertebrates, Matthew T. Mcdonough, Stephen S. Ditchkoff, Mark D. Smith, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

The wild pig (Sus scrofa) is a successful invasive species that has become well established outside of its native range in Eurasia. The invasive wild pig is the result of released or escaped domesticated livestock becoming feral, or Eurasian boar introduced for hunting purposes. The global spread of wild pigs has recently been exacerbated in some areas, such as the USA, by anthropogenically assisted dispersal. Once established in novel ecosystems, wild pigs have the potential to have significant negative impacts on the ecosystem, and the scientific literature is replete with examples. It is generally accepted that wild pigs …


Use Of A Direct, Rapid Immunohistochemical Test For Diagnosis Of Rabies Virus In Bats, Charles E. Rupprecht, Lolita Van Pelt, April D. Davis, Richard B. Chipman, David L. Bergman 2022 LYSSA LLC

Use Of A Direct, Rapid Immunohistochemical Test For Diagnosis Of Rabies Virus In Bats, Charles E. Rupprecht, Lolita Van Pelt, April D. Davis, Richard B. Chipman, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Rabies, a zoonotic encephalitis due to transmission of a lyssavirus, such as rabies virus (RABV), has the highest case fatality of any infectious disease. A global program for the elimination of human rabies caused by dogs is proposed for realization by 2030. Sensitive, specific, and inexpensive diagnostic tests are necessary for enhanced surveillance to detect infection, inform public health and veterinary professionals during risk assessments of exposure, and support overall programmatic goals. Multiple laboratory techniques are used to confirm a suspect case of rabies. One method for the detection of lyssavirus antigens within the brain is the direct rapid immunohistochemical …


Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-MacInnis 2022 University of Alberta, Lakehead University

Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis

United States Geological Survey: Staff Publications

Fluid exsolution and melt evolution at the magmatic-hydrothermal transition are critical processes driving the metal enrichment of porphyry systems. Coeval fluid and melt inclusion assemblages in unidirectional solidification textures (USTs) at Saginaw Hill—a small, porphyry Cu system in southwestern Arizona—record a dynamic and repetitious process of fluid accumulation and release. The cores of quartz crystals throughout the UST bands host coeval silicate melt and brine inclusions but lack vapor-rich inclusions. This could indicate preferential expulsion of vapor and trapping of high-density brine during episodes of fracturing or the direct exsolution of single-phase high-salinity brine from the silicate melt. In contrast, …


Optimizing Management Of Invasions In An Uncertain World Using Dynamic Spatial Models, Kim M. Pepin, Amy J. Davis, Rebecca S. Epanchin-Niell, Andrew M. Gormley, Joslin L. Moore, Timothy J. Smyser, H. Bradley Shaffer, William L. Kendall, Katriona Shea, Michael C. Runge, Sophie McKee 2022 USDA National Wildlife Research Center

Optimizing Management Of Invasions In An Uncertain World Using Dynamic Spatial Models, Kim M. Pepin, Amy J. Davis, Rebecca S. Epanchin-Niell, Andrew M. Gormley, Joslin L. Moore, Timothy J. Smyser, H. Bradley Shaffer, William L. Kendall, Katriona Shea, Michael C. Runge, Sophie Mckee

United States Department of Agriculture Wildlife Services: Staff Publications

Dispersal drives invasion dynamics of nonnative species and pathogens. Applying knowledge of dispersal to optimize the management of invasions can mean the difference between a failed and a successful control program and dramatically improve the return on investment of control efforts. A common approach to identifying optimal management solutions for invasions is to optimize dynamic spatial models that incorporate dispersal. Optimizing these spatial models can be very challenging because the interaction of time, space, and uncertainty rapidly amplifies the number of dimensions being considered. Addressing such problems requires advances in and the integration of techniques from multiple fields, including ecology, …


Ambient Air Pollution Exposure And Increasing Depressive Symptoms In Older Women: The Mediating Role Of The Prefrontal Cortex And Insula, Andrew J. Petkus, Susan M. Resnick, Xinhui Wang, Daniel P. Beavers, Mark A. Espeland, Margaret Gatz, Tara Gruenewald, Joshua Millstein, Helena C. Chui, Joel D. Kaufman, JoAnn E. Manson, Gregory A. Wellenius, Eric A. Whitsel, Keith Widaman, Diana Younan, Jiu-Chiuan Chen 2022 University of Southern California

Ambient Air Pollution Exposure And Increasing Depressive Symptoms In Older Women: The Mediating Role Of The Prefrontal Cortex And Insula, Andrew J. Petkus, Susan M. Resnick, Xinhui Wang, Daniel P. Beavers, Mark A. Espeland, Margaret Gatz, Tara Gruenewald, Joshua Millstein, Helena C. Chui, Joel D. Kaufman, Joann E. Manson, Gregory A. Wellenius, Eric A. Whitsel, Keith Widaman, Diana Younan, Jiu-Chiuan Chen

Psychology Faculty Articles and Research

Exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) have been associated with the emergence of depressive symptoms in older adulthood, although most studies used cross-sectional outcome measures. Elucidating the brain structures mediating the adverse effects can strengthen the causal role between air pollution and increasing depressive symptoms. We evaluated whether smaller volumes of brain structures implicated in late-life depression mediate associations between ambient air pollution exposure and changes in depressive symptoms. This prospective study included 764 community-dwelling older women (aged 81.6 ± 3.6 in 2008–2010) from the Women's Health Initiative Memory Study (WHIMS) Magnetic …


An Efficient Method Of Evaluating Multiple Concurrent Management Actions On Invasive Populations, Amy J. Davis, Randy Farrar, Brad Jump, Parker Hall, Travis Guerrant, Kim M. Pepin 2022 USDA National Wildlife Research Center

An Efficient Method Of Evaluating Multiple Concurrent Management Actions On Invasive Populations, Amy J. Davis, Randy Farrar, Brad Jump, Parker Hall, Travis Guerrant, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Evaluating the efficacy of management actions to control invasive species is crucial for maintaining funding and to provide feedback for the continual improvement of management efforts. However, it is often difficult to assess the efficacy of control methods due to limited resources for monitoring. Managers may view effort on monitoring as effort taken away from performing management actions. We developed a method to estimate invasive species abundance, evaluate management effectiveness, and evaluate population growth over time from a combination of removal activities (e.g., trapping, ground shooting) using only data collected during removal efforts (method of removal, date, location, number of …


Allodb: An R Package For Biomass Estimation At Globally Distributed Extratropical Forest Plots, Erika Gonzalez-Akre, Camille Piponiot, Mauro Lepore, Valentine Herrmann, James A. Lutz, Jennifer L. Baltzer, Christopher W. Dick, Gregory S. Gilbert, Fangliang He, Michael Heym, Alejandra I. Huerta, Patrick A. Jansen, Daniel J. Johnson, Nikolai Knapp, Kamil Král, Dunmei Lin, Yadvinder Malhi, Sean M. McMahon, Jonathan A. Myers, David Orwig, Diego I. Rodríguez-Hernández, Sabrina E. Russo, Jessica Shue, Xugao Wang, Amy Wolf, Tonghui Yang, Stuart J. Davies, Kristina J. Anderson-Teixeira 2022 Conservation and Research Center (National Zoo)

Allodb: An R Package For Biomass Estimation At Globally Distributed Extratropical Forest Plots, Erika Gonzalez-Akre, Camille Piponiot, Mauro Lepore, Valentine Herrmann, James A. Lutz, Jennifer L. Baltzer, Christopher W. Dick, Gregory S. Gilbert, Fangliang He, Michael Heym, Alejandra I. Huerta, Patrick A. Jansen, Daniel J. Johnson, Nikolai Knapp, Kamil Král, Dunmei Lin, Yadvinder Malhi, Sean M. Mcmahon, Jonathan A. Myers, David Orwig, Diego I. Rodríguez-Hernández, Sabrina E. Russo, Jessica Shue, Xugao Wang, Amy Wolf, Tonghui Yang, Stuart J. Davies, Kristina J. Anderson-Teixeira

School of Natural Resources: Faculty Publications

Allometric equations for calculation of tree above-ground biomass (AGB) form the basis for estimates of forest carbon storage and exchange with the atmosphere. While standard models exist to calculate forest biomass across the tropics, we lack a standardized tool for computing AGB across boreal and temperate regions that comprise the global extratropics. Here we present an integrated R package, allodb, containing systematically selected published allometric equations and proposed functions to compute AGB. The data component of the package is based on 701 woody species identified at 24 large Forest Global Earth Observatory (ForestGEO) forest dynamics plots representing a wide diversity …


Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich 2022 USDA Forest Service Luquillo

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …


Economics Of Cormorant Predation On Catfish Farms, Carole Engle, Ganesh Kumar, Terrel Christie, Brian S. Dorr, Brian Davis, Luke Roy, Anita Kelly 2022 Virginia Tech University

Economics Of Cormorant Predation On Catfish Farms, Carole Engle, Ganesh Kumar, Terrel Christie, Brian S. Dorr, Brian Davis, Luke Roy, Anita Kelly

United States Department of Agriculture Wildlife Services: Staff Publications

The Double-crested Cormorant is the primary avian predator on catfish farms causing significant economic losses primarily due to 1) on-farm expenditures related to bird-management activities and 2) value of the catfish lost to cormorants. This comprehensive economic study quantified these two economic effects by surveying catfish farms in the delta regions of Mississippi and Arkansas. On-farm expenditures for bird scaring were used to quantify bird-management costs. Economic losses from fish consumed by cormorants were quantified by evaluating data from field studies of the abundance, distribution, and diet of cormorants in the Mississippi delta. This study found that catfish farmers …


Water Insecurity, Water Borrowing, And Psychosocial Stress Among Daasanach Pastoralists In Northern Kenya, Leslie Ford, HIlary J. Bethancourt, Zane Swanson, Rosemary Nzunza, Amber Wutich, Alexandra Brewis, Sera Young, David Almeida, Matthew J. Douglass, Emmanuel K. Ndiema, David R. Braun, Herman Pontzer, Asher Y. Rosinger 2022 The Pennsylvania State University

Water Insecurity, Water Borrowing, And Psychosocial Stress Among Daasanach Pastoralists In Northern Kenya, Leslie Ford, Hilary J. Bethancourt, Zane Swanson, Rosemary Nzunza, Amber Wutich, Alexandra Brewis, Sera Young, David Almeida, Matthew J. Douglass, Emmanuel K. Ndiema, David R. Braun, Herman Pontzer, Asher Y. Rosinger

School of Natural Resources: Faculty Publications

This article quantifies Daasanach water insecurity experiences in Northern Kenya, examines how water insecurity is associated with water borrowing and psychosocial stress, and evaluates if water borrowing mitigates the stress from water insecurity. Of 133 households interviewed in 7 communities, 95% were water insecure and 74.4% borrowed water three or more times in the prior month. Regression analyses demonstrate water borrowing frequency moderates the relationship between water insecurity and psychosocial stress. Only those who rarely or never borrowed water reported greater stress with higher water insecurity. The coping mechanism of water borrowing may help blunt water insecurity-related stress.


The Social Networks Of Manureshed Management, Gwendwr Rhiannon Meredith, Sheri Spiegal, Peter J. A. Kleinman, Daren Harmel 2022 University of Nebraska-Lincoln

The Social Networks Of Manureshed Management, Gwendwr Rhiannon Meredith, Sheri Spiegal, Peter J. A. Kleinman, Daren Harmel

School of Natural Resources: Faculty Publications

Manureshed management—the strategic use of manure nutrients that prioritizes recycling between livestock systems and cropping systems—provides a comprehensive framework for sustainable nutrient management that necessitates the collaboration of many actors. Understanding the social dimensions of collaboration is critical to implement the strategic and technological requirements of functional manuresheds. To improve this understanding, we identified aspirational networks of actors involved in manureshed management across local, regional, and national scales, principally in the United States, elucidating key relationships and highlighting the breadth of interactions essential to successful manureshed management. We concluded that, although the social networks vary with scale, the involvement of …


Editorial: Geospace Observation Of Natural Hazards, Dimitar Ouzounov, Jann-Yenq Liu, Patrick T. Taylor, Katsumi Hattori 2022 Chapman University

Editorial: Geospace Observation Of Natural Hazards, Dimitar Ouzounov, Jann-Yenq Liu, Patrick T. Taylor, Katsumi Hattori

Mathematics, Physics, and Computer Science Faculty Articles and Research

"This collection of technical papers aims to bring recent data from many sources into the study of natural hazards. They represent a multi-instrumental approach using both ground observations: Global Navigation Satellite System (GNSS); and Low Earth Orbiting Electromagnetic (LEO EM) satellites missions together with Earth Observations (EO), which could reveal new information. Results from latest satellite missions, [(NPP/NASA/NOAA(US), CENTINEL, Swarm/ESA (EU), HIMAWARI (JMA, Japan), FORMOSAT-5 (Taiwan, August 2017), CSES1 (China/Italy, Feb 2018), and FORMOSAT-7/COSMIC-2 (Taiwan/United States, May 2019)], are represented in this volume."


Tibetan Dust Accumulation Linked To Ecological And Landscape Response To Global Climate Change, Xianmei Huang, Xiaodong Miao, Qiufang Chang, Jiemei Zhong, Joseph A. Mason, Paul R. Hanson, Xianjiao Ou, Liubing Xu, Zhongping Lai 2022 Shantou University and Purdue University

Tibetan Dust Accumulation Linked To Ecological And Landscape Response To Global Climate Change, Xianmei Huang, Xiaodong Miao, Qiufang Chang, Jiemei Zhong, Joseph A. Mason, Paul R. Hanson, Xianjiao Ou, Liubing Xu, Zhongping Lai

School of Natural Resources: Faculty Publications

The Tibetan Plateau (TP) is a hotspot of earth system research, and understanding its landscape and ecosystem evolution has been hampered by the lack of time-constrained geological records. Geochronological data from 14 loess sites covering a large region in the Tibetan interior show that the TP loess, rather than accumulating during glacial periods, began aggrading at either 13.4 ± 0.4 or 9.9 ± 0.2 ka. An ecological threshold was crossed, when warmer and wetter conditions resulted in increased vegetation cover enabling dust trapping. This dust accumulation model is out of phase with that of the Chinese Loess Plateau (CLP) where …


Exploring Old Data With New Tricks: Long-Term Monitoring Indicates Spatial And Temporal Changes In Populations Of Sympatric Prairie Grouse In The Nebraska Sandhills, Danielle J. Berger, Jeffrey J. Lusk, Larkin A. Powell, John P. Carroll 2022 University of Nebraska-Lincoln

Exploring Old Data With New Tricks: Long-Term Monitoring Indicates Spatial And Temporal Changes In Populations Of Sympatric Prairie Grouse In The Nebraska Sandhills, Danielle J. Berger, Jeffrey J. Lusk, Larkin A. Powell, John P. Carroll

School of Natural Resources: Faculty Publications

The contiguous grasslands of the Sandhills region in Nebraska, USA, provide habitat for two sympatric, grassland-obligate species of grouse, the greater prairie-chicken (Tympanuchus cupido pinnatus) and the plains sharp-tailed grouse (Tympanuchus phasianellus jamesi). Collectively referred to as prairie grouse, these birds are monitored and managed jointly by wildlife practitioners who face the novel challenge of conserving historically allopatric species in shared range. We reconstructed region-wide and route-specific prairie grouse population trends in the Sandhills, using a 63-year timeseries of breeding ground counts aggregated from old reports and paper archives. Our objective was to repurpose historical data …


Validity And Reliability Of Drought Reporters In Estimating Soil Water Content And Drought Impacts In Central Europe, Lenka Bartošová, Milan Fischer, Jan Balek, Monika Bláhová, Lucie Kudláčková, Filip Chuchma, Petr Hlavinka, Martin Možný, Pavel Zahradníček, Nicole Wall, Michael Hayes, Christopher Hain, Martha Anderson, Wolfgang Wagner, Zdeněk Žalud, Miroslav Trnka 2022 Mendel University in Brno

Validity And Reliability Of Drought Reporters In Estimating Soil Water Content And Drought Impacts In Central Europe, Lenka Bartošová, Milan Fischer, Jan Balek, Monika Bláhová, Lucie Kudláčková, Filip Chuchma, Petr Hlavinka, Martin Možný, Pavel Zahradníček, Nicole Wall, Michael Hayes, Christopher Hain, Martha Anderson, Wolfgang Wagner, Zdeněk Žalud, Miroslav Trnka

School of Natural Resources: Faculty Publications

Increasing drought is considered one of the major threats associated with climate change in central Europe. To provide an objective, quantitative tool that represents current drought conditions, the Czech Drought Monitor System (CzechDM) was established in 2012. Like other drought monitoring systems worldwide, the CzechDM uses several approaches to provide drought data. However, the CzechDM is unique internationally due to its utilization of a network of voluntary reporters (farmers) who complete a weekly online questionnaire to provide information about soil water content and the impacts of drought on crop yield. In this study, the results from the questionnaires from individual …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev 2022 Oregon State University

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Digital Commons powered by bepress