Tuning the Diversity of Open-Ended Responses from the Crowd

Crowdsourcing can solve problems that current fully automated systems cannot. Its effectiveness depends on the reliability, accuracy, and speed of the crowd workers that drive it. These objectives are frequently at odds with one another. For instance, how much time should workers be given to discover and propose new solutions versus deliberate over those currently proposed? How do we determine if discovering a new answer is appropriate at all? And how do we manage workers who lack the expertise or attention needed to provide useful input to a given task? We present a mechanism that uses distinct payoffs for three possible worker actions---propose,vote, or abstain---to provide workers with the necessary incentives to guarantee an effective (or even optimal) balance between searching for new answers, assessing those currently available, and, when they have insufficient expertise or insight for the task at hand, abstaining. We provide a novel game theoretic analysis for this mechanism and test it experimentally on an image---labeling problem and show that it allows a system to reliably control the balance betweendiscovering new answers and converging to existing ones

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

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

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

Effects of Phosphate Fertilizer Applications and Chemistry-Mineralogy of the Iron Oxide System on Phosphate Adsorption-Desorption by Stream Sediments : Final Report

(print) vii, 102 p. : ill., maps ; 28 cm.Item lacks publication date. Issue date supplied from WorldCat bibliographic recordDespite geologic, geomorphic, and land use differences, suspended sediments collected from the Muskingum River and its tributaries during spring flooding were remarkably uniform in mineralogy and size distribution. The greatest evidence of regional differences came from Moxahala Creek, which receives acid drainage from abandoned coal mines. As a result, Black Fork Creek, a tributary to Moxahala Creek, was chosen for detailed water quality and bottom sediment studies. Marked increases in dissolved SO4, Fe, and Al, and decreased. pH were observed in sections of the stream affected by acid mine drainage. In addition, a gelatinous yellow precipitate of iron was abundant in the bottom sediments below sources of pollution. This Fe-oxide or oxyhydroxide precipitate greatly increased surface area and reactivity of bottom sediments and added to the overall sediment load. A standard P adsorption procedure was proposed and the ability of four laboratories to produce consistent results over a wide range of soils was determined. Soil (0.5 or 1.0 g) was shaken in 0.01 mol L-1 CaCl2 at a soil: solution ratio of 1:25 in containers allowing a 50% head space for 24 hours at 24 to 26°C on an end-over-end shaker. Initial dissolved inorganic P concentrations of 0 to 323 u mol P L-1 (as KH2PO4 or NaH2PO4) were used and microbial activity inhibited by 20 g L-1 chloroform. Excellent agreement between the four laboratories was obtained for P adsorbed by the 12 soils studied, with a mean coefficient of variation over all P levels and soils of 0.91%. The laboratories also exhibited a high degree of replication of individual treatments with no laboratory showing a strong consistent bias across all soils and P levels in terms of P adsorption. Langmuir, Freundlich and Tempkin adsorption models were highly correlated with the adsorption data. Respective mean correlations for the 12 soils were 0.98, 0.97 and 0.95. The proposed method has the potential to produce consistent results which can be used to predict partitioning of dissolved inorganic P between solid and solution phases in the environment.Acknowledgements -- Abstract -- Chapter 1: Suspended Sediments of the Muskingum River Basin -- Chapter 2: Water and Bottom Sediment Quality in Streams Affected by Acid Coal Mine Drainage - a Study of the Black Fork Creek Watershed, Ohio -- Chapter 3: Interlaboratory Comparison of a Standardized Phosphorus Adsorption Procedur

Nitric oxide metabolite levels during the ectopic osteoinduction in rats

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.

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

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