Growth and Physiology of a Soil Organism Which is Resistant to the Toxic Effects of Sodium Selenite

The occurrence of selenium in soils of the United States and its cinnection with a disease of livestock originally called selenium poisoning , is well established. The states of North Dakota and South Dakota have both reported areas of land on which the disease occurs. In 1954, soil samples (from areas in South Dakota in which there is solenium poisoning) we\u27ve brought to the South Dakota State College Experiment Stot1on for analysis. From one of those samples, a bacterium was found which was noted as being resistant to the toxicity of selenium and also as being capable of reducing sodium selenite to the elemental form. In the process of this reduction, a foul odor described as resembling that of garlic or of rotten radishes was noted and at that time attributed to either hydrogen selenide or dimethyl selenide, both compounds having odors which resemble that of garlic. Little work was done in attempting to identify this organism except to attempt growth on silica gel, eosin methylene blue agar and soil patties

A Post-Loveland Pre-Iowan Loess in Western Iowa

The literature concerning the Pleistocene deposits of Iowa does not mention the presence of a loess sheet younger than the Loveland loess and older than the Iowan loess. The writer is of the opinion that such a loess exists in Iowa. The following evidence is presented to substantiate this conclusion. During the summer of 1948 the writer was engaged in a study of the Loveland formation of Iowa under the auspices of the Iowa Geological Survey. During the course of this investigation the presence of a post-Loveland and pre-Iowan loess was revealed in two exposure

Impacts of Cattle Grazing Management on Sediment and Phosphorus Loads in Surface Waters

In 2001 (year 1) and 2002 (year 2), three blocks of five 1-ac paddocks were grazed by beef cows on hills at the Iowa State University Rhodes Research and Demonstration Farm to determine the effects of grazing management on phosphorus (P) and sediment runoff from pastureland. Grazing management treatments included an ungrazed control, summer hay harvest with winter stockpiled grazing, grazing by continuous stocking to a residual sward height of 2 in., rotational stocking to a residual sward height of 2 in., and rotational stocking to a residual sward height of 4 in. At four times (late spring, mid-summer, early autumn, and early the subsequent spring) in each year, rainfall simulations were conducted at 6 sites within each paddock and 6 sites in a buffer zone down slope of each paddock. Rainfall simulators dripped at a rate of 2.8 in./hr over a 5.4- ft2 area for a period of 1.5 hours. Runoff was collected and analyzed for total sediment, total P, and total soluble P. Simultaneous to each rainfall simulation, ground cover, penetration resistance, surface roughness, slope, the contents of P and moisture of the soil, sward height and forage mass were measured. Losses of sediment, total P, and total soluble P were greater from grazed paddocks than ungrazed paddocks in year 1. However, in year 2, losses of sediment, total P, and total soluble P from paddocks grazed by rotational stocking to a sward height of 4 in. or harvested as hay during the summer and grazed during winter did not differ from ungrazed paddocks. In both years, losses of sediment, total P, and total soluble P from the buffer area immediately or 30 ft below the paddocks were lower than within the paddocks. Of the physical measurements, the proportion of ground cover was most highly related to sediment loss. Soil Bray-1 P concentrations did not differ between treatments, but were related to the losses of total and total soluble P. Results imply that sediment and phosphorus losses in pasture runoff may be reduced by managing rotational stocking to maintain adequate sward height and/or using vegetative buffer strips along pasture streams. Such management practices are particularly important in pastures on soils with high P concentrations

Effects of Grazing Management on Sediment and Phosphorus Losses in Run-off (A Progress Report)

In 2001 and 2002, pastures at the ISU Rhodes Research and Demonstration Farm were grazed to determine the effects of stocking treatment on nutrient and sediment loss from pastureland. Treatments included an ungrazed control (UG), summer hay harvest with winter stockpiled grazing (HS), continuous stocking to a residual height of 2 inches (2C), rotational stocking to a residual height of 2 inches (2R), and rotational stocking to a residual height of 4 inches (4R). At three times in 2001 (late spring, mid-summer, and fall) and four times in 2002 (early spring, late spring, mid-summer, and fall), rainfall simulations were conducted at 6 sites within each paddock and 6 sites in a buffer zone down slope from each paddock. Run-off was collected and analyzed for total sediment, total phosphorus, and dissolved phosphorus. Simultaneous to each rainfall simulation, ground cover, penetration resistance, surface roughness, slope, contents of phosphorus and moisture of the soil, and the sward height and mass of forage were measured. In years 1 (late spring 2001 through early spring 2002) and 2 (late spring 2002 through fall 2002), mean concentrations of sediment in runoff did not differ between ungrazed or grazed paddocks. Mean concentrations of total P in the run-off were greater (P \u3c .05) in paddocks grazed to 2 inches by continuous or rotational stocking than in paddocks that were ungrazed, grazed to 4 inches by rotational stocking or harvested as hay and grazed as stockpiled forage. In year 1, mean losses of sediment, total P, and soluble P were greater (P \u3c .1) from paddocks grazed to 2 inches by continuous or rotational stocking than other treatments. In year 2, mean losses of sediment and total P in paddocks grazed to 2 inches by continuous stocking and mean losses of soluble P from paddocks grazed to 2 inches by rotational stocking were greater (P \u3c .05) than the other treatments

Effects of Grazing Management on Pasture Production and Phosphorus Content of Forage (A Progress Report)

In spring 2001, pastures were grazed at the ISU Rhodes Research and Demonstration Farm to determine the effects of grazing management on pasture productivity and phosphorus (P) content of forage. Treatments included an ungrazed control, summer hay harvest with winter stockpiled grazing, continuous stocking to a residual height of 2 inches, rotational stocking to a residual height of 2 inches, and rotational stocking to a residual height of 4 inches. Forage production was greatest in June and July, decreased in August, and had a slight rebound in September and October before going dormant in November. Phosphorus concentration of forage was at a maximum in May at 0.27% and decreased to 0.11% in November. Ungrazed paddocks had no net uptake of P during the grazing season, while forage harvest stimulated P uptake. Forage growth and P uptake in buffers were unaffected by pasture management strategies that occurred upslope

The Effects of Conjoint Behavioral Consultation: Results of a 4-Year Investigation

Conjoint behavioral consultation (CBC) is a structured indirect form of service delivery in which parents, teachers, and other support staff are joined to work together to address the academic, social, or behavioral needs of an individual for whom all parties bear some responsibility. In this article, outcome data from 4 years of federally funded projects in the area of CBC are presented. Thirty graduate students were trained in CBC and were responsible for providing consultation services to parents and teachers of students with disabilities or at risk for academic failure. Consultation clients included 52 students with disabilities such as behavior disorders, attention-deficit hyperactivity disorder, anxiety, and learning disabilities. The primary research objective concerned assessing the efficacy of CBC across home and school settings. Secondarily, a prediction model was investigated based on client age, case complexity, and severity of symptoms. Perception of effectiveness, process acceptability, and consultee satisfaction with consultants was also investigated. Meaningful effect sizes were yielded across home and school settings. A model fitting client age and symptom severity was found to predict school effect size relatively well. Consultees’ perceptions of effectiveness, acceptability of CBC, and satisfaction with consultants were also favorable. Implications of these findings and directions for future research are explored

Paper Session I-C - Propulsion Advisory Tool

The data recording, display, and playback capabilities currently available for propulsion system engineers in the launch control room at the Kennedy Space Center lack the fidelity required to perform complex real time data analysis associated with Orbiter main propulsion system health management and anomaly resolution. During the hydrogen leak investigations (summer and fall of !90) on Space Shuttles Columbia and Atlantis, the deficiencies of the system became obvious. The troubleshooting team was hampered in drawing conclusions because they couldn\u27t perform real-time data analysis and by the cumbersome time consuming procedures required to do specific comparisons of present data with past data