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  • Jacobson, Astrid R  (15)
  • Baveye, Philippe C  (15)
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  • 1
    Language: English
    In: Computers & Education, April, 2009, Vol.52(3), p.571(10)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.compedu.2008.11.007 Byline: Astrid R. Jacobson (a)(b), Roberta Militello (c), Philippe C. Baveye (b)(d) Keywords: Applications in subject area; Media in education; Multimedia/hypermedia systems; Post-secondary education; Virtual reality Abstract: Multidisciplinary courses are being developed at a number of US colleges and universities to highlight the connections between the rise or fall of world civilizations and the sustainable or unsustainable uses of soil and water resources. The content presented in these courses is complex because it includes concepts from disciplines as varied as geology, soil science, politics, economics, history, and anthropology. The learning goals for the courses include developing skills in the critical analysis of complex "real-world" problems for which there is often no simple or correct solution. Didactic materials for such courses are limited. Field trips to sites around the world that present some of the issues covered in the course would be ideal, but are logistically challenging. We considered that a series of virtual field trips (VFTs) to sites around the world would allow us to present students with complicated real-world situations, with which to practice critical analysis skills. The VFTs envisaged are neither tutorials nor field/lab exercises. Rather, they are meant to be complex, multi-faceted representations of a past or current civilization and how it affects or is affected by its environment. We expect that the students will use the VFTs to explore the relationships between physical geography and culture and how the decisions or actions of a civilization impact natural resources and the environment and thus affect its fate. A goal of the VFTs is that through consideration of their experiences, students arrive at novel associations that lead to dynamic in-class dialogue about the material presented and a deeper understanding of the intricacies of the situation in the field. This article describes the process of assembling a VFT, and analyzes the technological and didactic choices the process requires. Our experience with a pilot VFT suggests that no single medium (i.e., video clips, interactive maps, animation sequences, etc.) is comprehensive enough to meet the course learning goals. Thus, a web-based, open architecture format was selected for the VFTs because of its simplicity, flexibility and extensibility. Each medium was selected for its ability to support the course learning goals. The learning process was mediated by the VFT text, questions for thought, and in-class discussions. Preliminary results with the pilot VFT are encouraging. Author Affiliation: (a) Plant, Soils and Climate Department, Utah State University, 4820 Old Main Hill, Logan, UT 84322-4820, USA (b) Laboratory of Geoenvironmental Science and Engineering, Cornell University, 1002 Bradfield Hall, Ithaca, NY 14853-1901, USA (c) Academic Technology and Media Services, Cornell Information Technologies, Cornell University, 215 Computing and Communications Center, Ithaca, NY 14853, USA (d) SIMBIOS Centre, Abertay University, 40 Bell Street, Dundee DD1 1HG, United Kingdom Article History: Received 22 September 2007; Revised 30 October 2008; Accepted 3 November 2008
    Keywords: Geography -- Analysis ; Digital Map Services -- Analysis ; Geographical Research -- Analysis ; Internet Videos -- Analysis ; Soils -- Analysis ; Water Resources -- Analysis ; Soil Science -- Analysis ; Universities And Colleges -- Analysis
    ISSN: 0360-1315
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  • 2
    Language: English
    In: Soil Science Society of America journal, 2011, Vol.75(6), pp.2037-2048
    Description: When the Soil Science Society of America was created, 75 yr ago, the USA was suffering from major dust storms, causing the loss of enormous amounts of topsoil as well as human lives. These catastrophic events reminded public officials that soils are essential to society's well-being. The Soil Conservation Service was founded and farmers were encouraged to implement erosion mitigation practices. Still, many questions about soil processes remained poorly understood and controversial. In this article, we argue that the current status of soils worldwide parallels that in the USA at the beginning of the 20th century. Dust bowls and large-scale soil degradation occur over vast regions in a number of countries. Perhaps more so even than in the past, soils currently have the potential to affect populations critically in several other ways as well, from their effect on global climate change, to the toxicity of brownfield soils in urban settings. Even though our collective understanding of soil processes has experienced significant advances since 1936, many basic questions still remain unanswered, for example whether or not a switch to no-till agriculture promotes C sequestration in soils, or how to account for microscale heterogeneity in the modeling of soil organic matter transformation. Given the enormity of the challenges raised by our (ab)uses of soils, one may consider that if we do not address them rapidly, and in the process heed the example of U.S. public officials in the 1930s who took swift action, humanity may not get a chance to explore other frontiers of science in the future. From this perspective, insistence on the fact that soils are critical to life on earth, and indeed to the survival of humans, may again stimulate interest in soils among the public, generate support for soil research, and attract new generations of students to study soils. ; p. 2037-2048.
    Keywords: Dust Storms ; Students ; Carbon Sequestration ; Topsoil ; Urban Soils ; Society ; No-Tillage ; Soil Organic Matter ; Humans ; Climate Change ; Models ; Farmers ; Soil Degradation ; Toxicity ; Soil Conservation
    ISSN: 0361-5995
    E-ISSN: 14350661
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  • 3
    Language: English
    In: Water, Air, & Soil Pollution, 2010, Vol.209(1), pp.377-390
    Description: Near-infrared diffuse reflectance sensing (NIRS) of soils has been the object of considerable interest and research in the last few years. This has been motivated by the prospect that this method seems to provide a cheap, convenient alternative to conventional, time-consuming methods for the measurement of a wide range of soil parameters. In particular, various authors have advocated that NIRS could be used to measure rapidly and non-destructively the concentration of trace metals in surface soils. Correlation analyses between NIRS spectra and trace metal concentration have yielded inconclusive results to date, suggesting that trace metal concentration may belong to a class of “tertiary” soil parameters, linked to NIRS spectra through “surrogate”, or indirect, correlations, involving some other primary or secondary parameter like clay or organic matter content, to which NIRS spectra are very sensitive. To assess the validity of this surrogate correlation hypothesis in the case of trace metals, experiments were carried out with soil samples varying only in the amount of trace metals they contain. Field-aged Hudson and Arkport soil pots spiked with Cu and Zn, freshly spiked samples of the same soils, and samples of a metalliferous peat soil from Western New York naturally rich in Cd and Zn were subjected to NIRS under laboratory conditions. Detailed analysis indicates that the NIR spectrum is sensitive to sample handling, including the orientation of the samples in the NIRS instrument, but that, at the same time, there is no discernable effect of the presence of trace metals on any part of the NIR spectrum. These results provide strong experimental support to the hypothesis of “surrogate” correlation for trace metals, and indicate that trace metals, even in severely contaminated soils, should not interfere with the NIR sensing of primary or secondary parameters, like organic matter content. Further work is needed to determine if this feature of NIR spectra extends to other soil chemical parameters.
    Keywords: Soil metal contamination ; Chemical analysis ; Near-infrared spectroscopy ; Remote sensing
    ISSN: 0049-6979
    E-ISSN: 1573-2932
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  • 4
    Language: English
    In: Computers & Education, 2009, Vol.52(3), pp.571-580
    Description: Multidisciplinary courses are being developed at a number of US colleges and universities to highlight the connections between the rise or fall of world civilizations and the sustainable or unsustainable uses of soil and water resources. The content presented in these courses is complex because it includes concepts from disciplines as varied as geology, soil science, politics, economics, history, and anthropology. The learning goals for the courses include developing skills in the critical analysis of complex “real-world” problems for which there is often no simple or correct solution. Didactic materials for such courses are limited. Field trips to sites around the world that present some of the issues covered in the course would be ideal, but are logistically challenging. We considered that a series of virtual field trips (VFTs) to sites around the world would allow us to present students with complicated real-world situations, with which to practice critical analysis skills. The VFTs envisaged are neither tutorials nor field/lab exercises. Rather, they are meant to be complex, multi-faceted representations of a past or current civilization and how it affects or is affected by its environment. We expect that the students will use the VFTs to explore the relationships between physical geography and culture and how the decisions or actions of a civilization impact natural resources and the environment and thus affect its fate. A goal of the VFTs is that through consideration of their experiences, students arrive at novel associations that lead to dynamic in-class dialogue about the material presented and a deeper understanding of the intricacies of the situation in the field. This article describes the process of assembling a VFT, and analyzes the technological and didactic choices the process requires. Our experience with a pilot VFT suggests that no single medium (i.e., video clips, interactive maps, animation sequences, etc.) is comprehensive enough to meet the course learning goals. Thus, a web-based, open architecture format was selected for the VFTs because of its simplicity, flexibility and extensibility. Each medium was selected for its ability to support the course learning goals. The learning process was mediated by the VFT text, questions for thought, and in-class discussions. Preliminary results with the pilot VFT are encouraging.
    Keywords: Applications in Subject Area ; Media in Education ; Multimedia/Hypermedia Systems ; Post-Secondary Education ; Virtual Reality ; Education
    ISSN: 0360-1315
    E-ISSN: 1873-782X
    Source: ScienceDirect Journals (Elsevier)
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  • 5
    Language: English
    In: Frontiers in Environmental Science, 01 June 2017, Vol.5
    Description: Groundwater contamination by oocysts of the waterborne pathogen Cryptosporidium parvum is a significant cause of animal and human disease worldwide. Although research has been undertaken in the past to determine how specific physical and chemical properties of soils affect the risk of groundwater contamination by C. parvum, there is as yet no clear conclusion concerning the range of mobility of C. parvum that one should expect in field soils. In this context, the key objective of this research was to determine the magnitude of C. parvum transport in a number of soils, under conditions in which fast and preferential transport has been successfully prevented. C. parvum oocysts were applied at the surface of different soils and subjected to artificial rainfall. Apparently for the first time, quantitative PCR was used to detect and enumerate oocysts in the soil columns and in the leachates. The transport of oocysts by infiltrating water, and the considerable retention of oocysts in soil was demonstrated for all soils, although differences in the degree of transport were observed with soils of different types. More oocysts were found in leachates from sandy loam soils than in leachates from loamy sand soils and the retention of oocysts in different soils did not significantly differ. The interaction of various processes of the hydrologic system and biogeochemical mechanisms contributed to the transport of oocysts through the soil matrix. Results suggest that the interplay of clay, organic matter, and Ca2+ facilitates and mediates the transfer of organic matter from mineral surfaces to oocysts surface, resulting in the enhanced breakthrough of oocysts through matrices of sandy loam soils compared to those of loamy sand soils. Although the number of occysts that penetrate the soil matrix account for only a small percentage of initial inputs, they still pose a significant threat to human health, especially in groundwater systems with a water table not too distant from the soil surface. The results of the research demonstrate a critical need for the simultaneous study of the interaction of various processes affecting oocysts transport in the subsurface, and for its expansion into complex systems, in order to obtain a coherent picture of the behavior of C. parvum oocysts in soils.
    Keywords: Cryptosporidium ; Microorganisms ; Groundwater ; Soil Transport ; Qpcr ; Environmental Sciences
    E-ISSN: 2296-665X
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  • 6
    Language: English
    In: Geoderma, 2009, Vol.151(3), pp.126-127
    Keywords: Agriculture
    ISSN: 0016-7061
    E-ISSN: 1872-6259
    Source: ScienceDirect Journals (Elsevier)
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  • 7
    Language: English
    In: Geoderma, August 15, 2009, Vol.152(1-2), p.171(10)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.geoderma.2009.06.002 Byline: Chun-Yu Wu (a), Astrid R. Jacobson (b), Magdeline Laba (c), Philippe C. Baveye (d) Keywords: Soil structure; Aggregation; Remote sensing; Spectroscopy; Soil water content Abstract: Near-infrared reflectance sensing (NIRS) has stimulated widespread enthusiasm in recent years among soil scientists, in part for its potential to lead to the design of new "proximal" soil sensors in support of precision agriculture, and to increase significantly the amount of information that can be obtained about soils from remote sensors. However, a practical difficulty this technique faces is that soils in the field, unlike the sieved, repacked soil samples used in the laboratory, are generally moist and have uneven surfaces, especially after tillage. Unfortunately, little is known at this point on the effect of surface roughness on NIR spectra. In this context, the present research focuses on the application of NIRS, under laboratory conditions, to chunks (artificially isolated particles or aggregates) of soil of average sizes between 0.04 and 8mm, obtained in 5 different soils with contrasting features, and repacked in Petri dishes. NIRS measurements were performed when the soils were air-dry, and after rewetting to near-saturation. In virtually all cases, except at the finest chunk size in two soils, the near-infrared reflectance decreased regularly as chunk size increased. Near-saturation of the soils with deionized water resulted in further decreases in reflectance, which obliterated to varying extent the dependence of the reflectance on chunk size. For most cases, whether the soils were dry or near-saturated, computation of the first derivative of the NIR spectra, especially when preceded by moving-average or wavelet-based smoothing, resulted in transformed signals that were virtually independent of surface roughness in a number of distinct spectral regions. These observations suggest that in the range of soil chunk sizes considered, it might be possible practically to circumvent the dependence of NIRS on surface roughness. Author Affiliation: (a) Laboratory of Geoenvironmental Science and Engineering, Bradfield Hall, Cornell University, Ithaca, NY 14853, USA (b) Plants, Soils and Climate Department, Utah State University, 4820 Old Main Hill, Logan, UT 84322-4820, USA (c) Department of Civil and Environmental Engineering, Rice Hall, Cornell University, Ithaca, NY 14853, USA (d) SIMBIOS Centre, Abertay University, Bell Street, Dundee DD1 1HG, UK Article History: Received 4 November 2008; Revised 5 June 2009; Accepted 10 June 2009
    Keywords: Soil Structure ; Soils ; Agriculture ; Soil Moisture
    ISSN: 0016-7061
    Source: Cengage Learning, Inc.
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  • 8
    In: Soil Science, 2009, Vol.174(8), pp.456-465
    Description: With rising ambient temperature and atmospheric carbon dioxide levels, there is an urgent need to monitor soil carbon stocks over large regions of the earth. Near-infrared diffuse reflectance sensing (NIRS) of soils, using satellite- or airplane-based instruments, is increasingly regarded as a potential method of choice for this purpose. Considerable research has been devoted to NIRS in the last few years, but this research has been generally restricted to sieved air-dried soils analyzed under laboratory conditions. For NIRS to be useful for the estimation of soil carbon stocks in the field, a technique must be developed to account, among other things, for the presence of moisture in the surface layer of soils. In this context, a first objective of the research described in this article was to determine whether, for three soils with contrasting characteristics, a simple constant proportionality factor relates NIR spectra obtained at different moisture contents, and whether there is relative constancy of this proportionality factor among soils, suggesting the possibility of a practical strategy to correct NIR spectra for soil moisture. A second objective of the research was to use ratio and derivative analysis to identify portions of NIR spectra that appear least affected by moisture content and on which a determination of other parameters such as organic matter content could be based. Because constant proportionality of the spectra at different moisture contents seems elusive, at best, the most significant result obtained is the identification of specific wavelength ranges in the NIR spectra, at 800 to 1400 nm, 1600 to 1700 nm, 2100 to 2200 nm, and 2300 to 2500 nm, where the first derivative of the spectra seems independent of the moisture content of the soil samples. This observation suggests that an operational method could be developed, focused on these wavelength intervals, to obtain moisture-independent estimates of a range of soil parameters under field conditions.
    Keywords: Soil Water Content ; Near-Infrared Reflectance Spectroscopy ; Soil Organic Matter ; Visible Near-Infrared Diffuse Reflectance Sensing;
    ISSN: 0038-075X
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  • 9
    Language: English
    In: Geoderma, 2009, Vol.152(1), pp.171-180
    Description: Near-infrared reflectance sensing (NIRS) has stimulated widespread enthusiasm in recent years among soil scientists, in part for its potential to lead to the design of new “proximal” soil sensors in support of precision agriculture, and to increase significantly the amount of information that can be obtained about soils from remote sensors. However, a practical difficulty this technique faces is that soils in the field, unlike the sieved, repacked soil samples used in the laboratory, are generally moist and have uneven surfaces, especially after tillage. Unfortunately, little is known at this point on the effect of surface roughness on NIR spectra. In this context, the present research focuses on the application of NIRS, under laboratory conditions, to chunks (artificially isolated particles or aggregates) of soil of average sizes between 0.04 and 8 mm, obtained in 5 different soils with contrasting features, and repacked in Petri dishes. NIRS measurements were performed when the soils were air-dry, and after rewetting to near-saturation. In virtually all cases, except at the finest chunk size in two soils, the near-infrared reflectance decreased regularly as chunk size increased. Near-saturation of the soils with deionized water resulted in further decreases in reflectance, which obliterated to varying extent the dependence of the reflectance on chunk size. For most cases, whether the soils were dry or near-saturated, computation of the first derivative of the NIR spectra, especially when preceded by moving-average or wavelet-based smoothing, resulted in transformed signals that were virtually independent of surface roughness in a number of distinct spectral regions. These observations suggest that in the range of soil chunk sizes considered, it might be possible practically to circumvent the dependence of NIRS on surface roughness.
    Keywords: Soil Structure ; Aggregation ; Remote Sensing ; Spectroscopy ; Soil Water Content ; Agriculture
    ISSN: 0016-7061
    E-ISSN: 1872-6259
    Source: ScienceDirect Journals (Elsevier)
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  • 10
    Language: English
    In: Environmental Science & Technology, 09/2007, Vol.41(18), pp.6343-6349
    Description: The response of microorganisms to metal contamination of soils varies significantly from one investigation to another. One explanation is that metals are heterogeneously distributed at spatial scales relevant to microbes and that microoorganisms are able to avoid zones of intense contamination. This article aims to assess the microscale distribution of Cu in a vineyard soil. The spatial distribution of Cu was measured at two resolutions (0.3 mm and 20 mm) in thin sections of the surface 4 cm of undisturbed soil by electron microprobe and synchrotron X-ray microfluorescence spectroscopy. Bulk physicochemical analyses of Cu, pH, organic matter, texture, and mineralogy were performed. The results indicate that the Cu distribution is strongly heterogeneous at both scales of observation. Entire regions of the thin sections are virtually devoid of Cu, whereas highly localized "hotspots" have Cu signal intensities thousands of times higher than background. The distribution of Rb, or Al and Si, indicators of clay minerals, or Fe (iron (hydr)oxides), show that Cu is not preferentially associated with these mineral phases. Instead, Cu hotspots are associated with particulate organic matter. These observations suggest modification of current sampling protocols, and design of ecotoxicological experiments involving microorganisms, for contaminated soils.
    Keywords: Vineyards ; Fluorescence ; Spatial Distribution ; Contamination ; Heavy Metals ; Hot Spots ; Organic Matter ; Electron Microprobe ; Retinoblastoma Protein ; Copper ; Spectroscopy ; Clays ; Soil Microorganisms ; Soil ; Soil Pollution ; Particulate Organic Matter ; Ionizing Radiation ; Microorganisms ; Mapping ; Sampling ; Ph Effects ; Iron ; Minerals ; Hot Spots ; Metals ; Clay ; Fluorescence ; Organic Matter ; Soil Contamination ; Particulates ; Mineralogy ; Spatial Distribution ; Vineyards ; Microorganisms ; Minerals ; Iron ; Land Pollution ; Antibiotics & Antimicrobials;
    ISSN: 0013-936X
    E-ISSN: 1520-5851
    Source: American Chemical Society (via CrossRef)
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