Landslides in Shale-Derived Glacial Till

An area in south-east Iowa is notorious for landslides in both cut slopes and embankments. Most of the failed slopes have been modified to lower slope angles as attempted remediation; however in many instances the failure reoccurred. The dominant soil in the cuts and used for borrow material is Kansan age glacial till, while the underlying bedrock is Pennsylvanian shale of the Des Moines series. The till contains significant amounts of the underlying bedrock. In an effort to gain insight into the cause of these failures, an embankment with extensive failures in Monroe County was studied. One slide selected for intensive study was at a 2V:1H slope and 8 meters high. The slide was 16 meters in length. The failure zone was essentially parallel to the original surface at a depth of 0.75 meters. Average strength parameters used in stability analyses produced factors of safety that indicate that failure should not have occurred. X-ray diffraction tests indicate a slightly broader montmorillonite peak in surface soils compared to interior embankment soils, which may indicate the presence of intracrystalline moisture and perhaps a different exchangeable cation in the failure zone soil. This subtle difference could account for a lower shear strength in the soil at the surface of the embankment. It is interpreted that the most likely cause of failure is the reduction of cohesion near the embankment surface after construction. If the reduction of strength is due to weathering and saturation leading to the subsequent swelling of the montmorillonite is the cause of failure, then remediation such as flattening the slope would be ineffective. The use of other soil strengthening techniques such as the use of geosynthetics, minipiles, or chemical stabilization would provide better, long term stability

Quantitative Variations in Loess Topography

Morphometric studies were conducted on the loess mantled and loess depositional topographies of the Wisconsin Age loess of western Iowa. Slope angle and absolute drainage density decrease with increasing distance from the Missouri River as a power function. The rate of decrease of both parameters is great for the first 8 miles from the river and less for the next 24 miles. Although the change between the two types of topography is gradual, it is suggested that the transition from rapid to more gentle decrease of slope angle or drainage density with distance from the river be used as a quantitative criterion for the boundary between the two topographies. Relationships exist between loess thickness and absolute drainage density and slope angle which permit estimation of loess thickness from a measurement of these topographic parameters. It is suggested that measurements of this type will provide a remote sensing technique for the quantitative evaluation of other loess properties

Depth Studies of Wisconsin Loess in Southwestern Iowa: IV. Shear Strength

This report is the fourth in a series of papers dealing with depth variations in the engineering properties of Wisconsin-age loess in Iowa. Previous studies have included graduation and in-place density (Davidson, et. al. 1953), clay and carbonate contents (Handy and Davidson, 1956), and organic matter, manganese and iron contents (Daniels et. al. 1960). This paper discusses the variation of the Coulomb shear strength parameters c (cohesive shear strength) and ø (angle of internal friction) in the loess in a cut located in N. W. 1/4 Sec. 3, T77N, R44W, Harrison County, Iowa. This cut was described in detail and proposed as a new type section for the Loveland formation by Daniels and Handy (1959). In general, the hill and cut consist of approximately 130 feet of post-Farmdale loess, over 12 feet of Farmdale loess, over 20 feet of Loveland loess, over oxidized calcareous Kansan (?) till. The upper 30 feet of loess is not cut and was not included in the description by Daniels et. al. (1959). Below this, the upper 40\u27 of the cut has a slope of 50 per cent, and the lower 90 feet is cut into three near-vertical benches

Rollup subsolar array Quarterly technical report, 1 Dec. 1969 - 28 Feb. 1970

Prototype test model of 30-watt per pound rollup solar arra

Ornamental plants: annual reports and research reviews, 2002

Ohio State University Extension Nursery, Landscape, and Turf Team directory: 2003 / Jack Kerrigan -- Floriculture Industry Roundtable of Ohio: 2003 / Charles Behnke -- Ohio State University Extension 2002 Buckeye Yard and Garden Line evaluation survey / Amy K. Stone and James A. Chatfield -- Weather, environmental, and cultural problems of ornamental plants in Ohio: 2002 / Pamela J. Bennett -- Infectious disease problems of ornamental plants in Ohio: 2002 / James A. Chatfield, Nancy A. Taylor, Erik A. Draper, and Joseph F. Boggs -- A biological calendar for predicting pest activity: six years of plant and insect phenology in Secrest Arboretum / Daniel A. Herms -- Biological suppression of foliar diseases of ornamental plants with composted manures, biosolids, and Trichoderma hamatum 382 / Harry A. J. Hoitink, Carol A. Musselman, Terry L. Moore, Leona E. Horst, Charles R. Krause, Randy A. Zondag, and Hannah Mathers -- Growth and water use by four leguminous tree species in containers on a gravel surface or embedded in mulch / Michael Knee, Daniel K. Struve, Michael H. Bridgewater, and Joseph W. Phillips -- The effects of sprayer configuration on efficacy for the control of scab on crabapple / Charles R. Krause, Richard C. Derksen, Leona E. Horst, Randall Zondag, Ross D. Brazee, Michael G. Klein, and Michael E. Reding -- Update on honeylocust knot / Pierluigi Bonello, Maria Bellizzi, and Harry A. J. Hoitink -- Control of phytophthora and other major diseases of Ericaceous plants / Harry A. J. Hoitink, Steven T. Nameth, and James C. Locke -- Is your landscape mulch going up in smoke? / Larry G. Steward, T. Davis Sydnor, and Bert Bishop -- IR-4 ornamental trials conducted by USDA-ARS in Ohio: 2002 / Betsy A. Anderson, Michael E. Reding, Michael G. Klein, and Charles R. Krause -- Research on black vine weevil and white grubs in ornamental nurseries-in Ohio by USDA-ARS / Michael E. Reding, Michael G. Klein, Ross D. Brazee, and Charles R. Krause -- Herbaceous ornamental field trial results in Clark County, Ohio – 2002 / Pamela J. Bennett -- Results of annual trial gardens at the Cincinnati Zoo and Botanical Garden for 2002 / Dave Dyke -- Ohio State University Learning Garden annual cultivar trials / Monica M. Kmetz-Gonzalez and Claudio C. Pasian -- A collection of crabapple knowledge from Secrest Arboretum: 1993-2002 / Erik A. Draper, James A. Chatfield, and Kenneth D. Cochran -- Key results of the 2001 Ohio Green Industry Survey / Gary Y. Gao, John J. Smith, James A. Chatfield, Joseph F. Boggs, Erik A. Draper, and Hannah Mathers -- The USDA/Agricultural Research Service research weather network in Lake County, Ohio - 2002 update / R. D. Brazee, R. C. Derksen, C. R. Krause, K. A. Williams, D. Lohnes, M. G. Klein, M. Reding, R. Lyons, W. Hendricks, R. Zondag, R. D. Fox, and D. Herms -- The OSU Chadwick Arboretum Learning Gardens / Dr. Steven Still and Annette Duetz -- Choosing soil testing labs / Gary Y, Gao, Maurice E. Watson, Joseph F. Boggs, and James A. Chatfield -- Top horticultural references for a green industry professional's library / Gary Y. Gao and Pamela J. Bennett -- The maples of Secrest Arboretum / Gary W. Graham, James A. Chatfield, and Kenneth D. Cochran -- Deck the halls with boughs from Ollie! / Kenneth D. Cochran and James A. Chatfiel

Developmental expression of retinoic acid receptors (RARs)

Here, I review the developmental expression features of genes encoding the retinoic acid receptors (RARs) and the 'retinoid X' or rexinoid receptors (RXRs). The first detailed expression studies were performed in the mouse over two decades ago, following the cloning of the murine Rar genes. These studies revealed complex expression features at all stages of post-implantation development, one receptor gene (Rara) showing widespread expression, the two others (Rarb and Rarg) with highly regionalized and/or cell type-specific expression in both neural and non-neural tissues. Rxr genes also have either widespread (Rxra, Rxrb), or highly-restricted (Rxrg) expression patterns. Studies performed in zebrafish and Xenopus demonstrated expression of Rar and Rxr genes (both maternal and zygotic), at early pre-gastrulation stages. The eventual characterization of specific enzymes involved in the synthesis of retinoic acid (retinol/retinaldehyde dehydrogenases), or the triggering of its catabolism (CYP26 cytochrome P450s), all of them showing differential expression patterns, led to a clearer understanding of the phenomenons regulated by retinoic acid signaling during development. Functional studies involving targeted gene disruptions in the mouse, and additional approaches such as dominant negative receptor expression in other models, have pinpointed the specific, versus partly redundant, roles of the RARs and RXRs in many developing organ systems. These pleiotropic roles are summarized hereafter in relationship to the receptors’ expression patterns

Dissolving the Dichotomies Between Online and Campus-Based Teaching: a Collective Response to The Manifesto for Teaching Online (Bayne et al. 2020)

This article is a collective response to the 2020 iteration of The Manifesto for Teaching Online. Originally published in 2011 as 20 simple but provocative statements, the aim was, and continues to be, to critically challenge the normalization of education as techno-corporate enterprise and the failure to properly account for digital methods in teaching in Higher Education. The 2020 Manifesto continues in the same critically provocative fashion, and, as the response collected here demonstrates, its publication could not be timelier. Though the Manifesto was written before the Covid-19 pandemic, many of the responses gathered here inevitably reflect on the experiences of moving to digital, distant, online teaching under unprecedented conditions. As these contributions reveal, the challenges were many and varied, ranging from the positive, breakthrough opportunities that digital learning offered to many students, including the disabled, to the problematic, such as poor digital networks and access, and simple digital poverty. Regardless of the nature of each response, taken together, what they show is that The Manifesto for Teaching Online offers welcome insights into and practical advice on how to teach online, and creatively confront the supremacy of face-to-face teaching

What’s retinoic acid got to do with it? Retinoic acid regulation of the neural crest in craniofacial and ocular development

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151310/1/dvg23308.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151310/2/dvg23308_am.pd