533 research outputs found

    Buried Pre-Illinoian-Age Lacustrine Deposits with “Green Rust” Colors in Clermont County, Ohio

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    Author Institution: Bennett & Williams Environmental Consultants Inc., Columbus, OHAuthor Institution: The Ohio State University, School of Environment and Natural Resources, Columbus, OHBuried, Pre-Illinoian-age lacustrine deposits found in at least two separate bedrock valleys in Clermont County, OH, exhibit brilliant colors of “green rust” that alter rapidly when exposed to oxygen. In these settings, the materials are leached of calcium carbonate but the iron has not undergone the redoximorphic depletion typically observed in gleyed hydric soils. Water movement has been exclusively through fractures and along varved bedding planes for approximately 700,000 years, indicating that in these settings, matrix flow is not occurring. The overlying Pre-Illinoian-age Backbone Creek glacial till also exhibits gleyed coloration but these materials are not leached of calcium carbonate. These materials also oxidize when exposed to air, indicating that again, the iron is not removed from the till. A possible correlation to similar permeability properties in northwest Ohio Late-Wisconsinan-age lacustrine materials and fine-grained tills is drawn. The “green rust” provides evidence for minimal to no matrix flow in fine-grained materials and supports the Ohio Fracture Flow Working Group recommendation that water movement along fractures, varved bedding planes, through sand stringers, and along paleosol unconformities be assumed unless matrix contributions have been documented and can be confirmed in these settings

    La mineralogía de la arcilla del suelo Nipe

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    The mineralogy of Nipe clay was characterized by means of X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), BET surface area, and chemical analysts. The major components of the clay fraction are goethite, gibbsite, hematite and kaolinite. Goethite is the predominant iron oxide as indicated by the high intensity of the XRD peaks. The unit cell dimensions of goethite, estimated from the XRD data, were a = 4.603 Å, b = 9.806 Å and c = 3.002 Å. The unit cell dimensions of hematite were a = 5.037 Å, and c = 13.735 Å. The extent of aluminum substitution in goethite and hematite was also estimated from the XRD data. The mole % Al in goethite, based on the d (111) value, was 15.57 mole percent, whereas when the a-dimension of the unit cell was used, a value of 12.86 mole percent was obtained. The estimated mole percent Al substitution in hematite was 0.67. The hematite/goethite ratio as estimated from the relative intensities of the 104 peak of hematite and the 110 peak of goethite was 0.51. Kaolinite showed a high capacity to absorb IR radiation as indicated by strong absorption peaks around 1000 and 3700 cm-1. The surface area of the clay as determined by the BET method was 55.26 m2/g. The ratio of Feox/Fed was very low (1.17x10-2), indicating that the iron oxides occur in well crystallized form.La mineralogía de la arcilla del suelo Nipe se caracterizó usando difracción de rayos X, análisis termal, espectroscopia de infrarojo, área superficial (BET) y análisis químico. Los principales componentes minerales de la arcilla son goetita, gibsita, hematita y caolinita. La intensidad de los picos correspondientes a goetita, revelada mediante el análisis de rayos X, indica que este mineral es el óxido de Fe predominante en la arcilla del suelo Nipe. Los parámetros estructurales de la celda unitaria de goetita, estimados del análisis de rayos X, fueron a = 4.603 Å, b = 9.806 Å, y c = 3.002 Å. Los parámetros estructurales de hematita fueron: a = 5.037 Å y c = 13.735 Å. De los datos de rayos X también se estimó el porcentaje molar de aluminio en goetita y hematita. Para el caso particular de la goetita, el porcentaje de Al se estimó a base del la distancia interplanar d(111) y a base del tamaño de la unidad estructural-a de la celda unitaria, obteniéndose valores de 15.57 y 12.86%, respectivamente, El porcentaje de aluminio en la hematita fue de 0.67%, y se estimó a base del tamaño de la unidad estructural-a de la celda unitaria. Se obtuvo una proporción de hematita/goetita de 0.51. La caolinita demostró gran capacidad para absorber la radiación infrarroja según lo indican los picos de absorción en la cercanía de los 1000 y 3700 cm-1. El área de superficie de la arcilla fue de 55.26 m2/g. El contenido de óxidos amorfos fue muy bajo (Feox/Fed = 1.17x 10-2), lo que indica que los óxidos de hierro están mayormente en forma cristalina

    Nitric oxide metabolite levels during the ectopic osteoinduction in rats

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    Abstract Nitric oxide (NO) is a cell-signaling molecule that has diverse biological functions. Recent evidence suggests that its production may regulate the metabolism of the osteoblasts and osteoclasts. The aim of this study was to evaluate levels of nitrite and nitrates (NO metabolites) during ectopic osteoinduction in rats. Eighteen male Sprague–Dawley rats (body weight 200–300 g) were used in this study. All animals were anesthetized and the right and left flank areas were shaved, and under aseptic conditions, a muscular pouch was created in each flank: the left was filled with 20 mg of demineralized bone matrix and the right remained empty (sham). Radiographs were taken at 2, 4, and 6 weeks after surgery to trace the ectopic bone formation and muscle mineralization. Blood samples were taken before (as baseline values) and at 2, 4, and 6 weeks after surgery. The mean values of NO metabolites after 6 weeks were significantly higher (p<0.05) than baseline data and at 2 weeks post-surgery. Results from this study indicate that the ectopic osteoinduction caused increased activity of the osteoblasts which subsequently caused increased serum levels of NO metabolites (nitrites and nitrates)

    Impaired Competence for Pretense in Children with Autism: Exploring Potential Cognitive Predictors.

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    Lack of pretense in children with autism has been explained by a number of theoretical explanations, including impaired mentalising, impaired response inhibition, and weak central coherence. This study aimed to empirically test each of these theories. Children with autism (n=60) were significantly impaired relative to controls (n=65) when interpreting pretense, thereby supporting a competence deficit hypothesis. They also showed impaired mentalising and response inhibition, but superior local processing indicating weak central coherence. Regression analyses revealed that mentalising significantly and independently predicted pretense. The results are interpreted as supporting the impaired mentalising theory and evidence against competing theories invoking impaired response inhibition or a local processing bias. The results of this study have important implications for treatment and intervention

    The Effects of Sequence and Delay on Crowd Work

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    A common approach in crowdsourcing is to break large tasks into small microtasks so that they can be parallelized across many crowd workers and so that redundant work can be more easily compared for quality control. In practice, this can re-sult in the microtasks being presented out of their natural order and often introduces delays between individual micro-tasks. In this paper, we demonstrate in a study of 338 crowd workers that non-sequential microtasks and the introduction of delays significantly decreases worker performance. We show that interruptions where a large delay occurs between two related tasks can cause up to a 102 % slowdown in com-pletion time, and interruptions where workers are asked to perform different tasks in sequence can slow down comple-tion time by 57%. We conclude with a set of design guide-lines to improve both worker performance and realized pay, and instructions for implementing these changes in existing interfaces for crowd work. Author Keywords Crowdsourcing; human computation; workflows; continuity

    Properties of the Fractured Glacial Till at the Madison County, Ohio, Field Workshop Pit Site

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    Author Institution: USDA/ARS, Soil Drainage Research Unit ; School of Natural Resources, The Ohio State University ; Department of Food, Agricultural and Biological Engineering, The Ohio State UniversityWater and contaminants obviously do move through the so-called impermeable glacial tills in Ohio. This study was conducted to illustrate the extensive presence of fractures in the till and to quantify the differences in hydraulic conductivity and physical and chemical properties between the fractureaffected zones and the till matrix. In situ measurements of the saturated hydraulic conductivity were made in small boreholes positioned either in the matrix or intersecting the fractures. Soil samples from both the fracture faces and the matrix were analyzed for particle size distribution, clay mineralogy, calcite, dolomite, and iron content. Hydraulic conductivity measured in boreholes intersecting fractures was 1.25 x 105 cm/sec (0.018 in/hr), one order of magnitude greater than in boreholes in the matrix. Particle size distribution was the same for the fracture faces and the matrix. The fracture faces showed no significant change in total clay content and a slight increase in expandable clay. Calcite content was 62% greater, dolomite content was 6% lower, and iron content was 73% lower on the fracture faces as compared to the matrix. The fractures affected approximately 7% of the soil volume

    Human Races Are Not Like Dog Breeds: Refuting a Racist Analogy

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    In 1956, evolutionary biologist J.B.S. Haldane posed a question to anthropologists: “Are the biological differences between human groups comparable with those between groups of domestic animals such as greyhounds and bulldogs…?” It reads as if it were posted on social media today. The analogy comparing human races to dog breeds is not only widespread in history and pop culture, but also sounds like scientific justification for eschewing the social construction of race, or for holding racist beliefs about human nature. Here we answer Haldane’s question in an effort to improve the public understanding of human biological variation and “race”—two phenomena that are not synonymous. Speaking to everyone without expert levels of familiarity with this material, we investigate whether the dog breed analogy for human race stands up to biology. It does not. Groups of humans that are culturally labeled as “races” differ in population structure, genotype–phenotype relationships, and phenotypic diversity from breeds of dogs in unsurprising ways, given how artificial selection has shaped the evolution of dogs, not humans. Our demonstration complements the vast body of existing knowledge about how human “races” differ in fundamental sociocultural, historical, and political ways from categories of nonhuman animals. By the end of this paper, readers will understand how the assumption that human races are the same as dog breeds is a racist strategy for justifying social, political, and economic inequality

    Geocoding police collision report data from California: a comprehensive approach

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    <p>Abstract</p> <p>Background</p> <p>Collision geocoding is the process of assigning geographic descriptors, usually latitude and longitude coordinates, to a traffic collision record. On California police reports, relative collision location is recorded using a highway postmile marker or a street intersection. The objective of this study was to create a geocoded database of all police-reported, fatal and severe injury collisions in the California Statewide Integrated Traffic Records System (SWITRS) for years 1997-2006 for use by public agencies.</p> <p>Results</p> <p>Geocoding was completed with a multi-step process. First, pre-processing was performed using a scripting language to clean and standardize street name information. A state highway network with postmile values was then created using a custom tool written in Visual Basic for Applications (VBA) in ArcGIS software. Custom VBA functionality was also used to incorporate the offset direction and distance. Intersection and address geocoding was performed using ArcGIS, StreetMap Pro 2003 digital street network, and Google Earth Pro. A total of 142,007 fatal and severe injury collisions were identified in SWITRS. The geocoding match rate was 99.8% for postmile-coded collisions and 86% for intersection-coded collisions. The overall match rate was 91%.</p> <p>Conclusions</p> <p>The availability of geocoded collision data will be beneficial to clinicians, researchers, policymakers, and practitioners in the fields of traffic safety and public health. Potential uses of the data include studies of collision clustering on the highway system, examinations of the associations between collision occurrence and a variety of variables on environmental and social characteristics, including housing and personal demographics, alcohol outlets, schools, and parks. The ability to build maps may be useful in research planning and conduct and in the delivery of information to both technical and non-technical audiences.</p
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