Tug of War with Grain: A Grain Safety Curriculum (Flyer)

This flier promotes the Tug-of-War with Grain farm safety curriculum. The online flier has links to Web pages with more details, including sample pages of the curriculum.https://lib.dr.iastate.edu/extension_ag_pubs/1002/thumbnail.jp

Wheat Loads and Vertical Pressure Distribution in a Full-scale Bin Part II—Detention

The vertical loads imposed on a full-scale bin floor by wheat were measured during a storage time of 6 h. The floor loads were determined to be dependent on the length of storage time. A linear regression model was developed to predict this change in loads in relation to detention time. The linear regression equation had coefficient of determination values ranging from 0.230 to 0.817. Analysis of the model slopes also indicated that fill height and radial location affect the vertical floor loads with a statistical significance level of 0.05. The radial distribution of vertical pressure during detention was measured. The vertical pressure distribution is dependent on radial location and is not uniformly distributed. Radial location significantly influenced the vertical pressure at the 0.05 significance level. The distribution pattern is similar to the filling condition

Wheat Loads and Vertical Pressure Distribution in a Full-scale Bin Part I — Filling

Flat-bottom cylindrical grain bins are subjected to unique loads and pressures during the filling process. The vertical and lateral loads imposed on a bin wall and the vertical load on a bin floor by wheat during filling were measured. The radial distribution of vertical pressure during filling was also measured. The vertical pressure was determined to be dependent on the radial location and was not uniformly distributed. The load distribution in a bin with an H/D ratio of 3 was 83% on the floor and 17% on the walls. Three widely used prediction equations of Janssen, Reimbert, and Walker were compared to the measured loads and pressures and were determined to have similar shapes but different parameters for a best fit to observed data

Waterfowl Trends in Back Bay, Virginia from 1954-1990

Back Bay, Virginia and Currituck Sound, North Carolina have long been noted and highly acclaimed as prime waterfowl wintering and migration areas. Although no formal waterfowl surveys were conducted prior to 1937, some gauge of waterfowl abundance can be obtained from harvest record examination. Harvest estimates based on extraordinarily well kept and recorded data of ten major waterfowl hunting clubs in Back Bay and Currituck Sound between 1872 and 1962 (Sincock, 1966) suggest that five million (5,000,000) ducks and 560,000 Canada geese were taken by hunting during that 90-year period. Waterfowl population trends in Back Bay for the 37-year period 1954-90 are the subject of this paper

Submerged Aquatic Vegetation Trends of Back Bay, Virginia

(First Paragraph): Submerged aquatic vegetation (SAV) is an important part of a healthy Back Bay ecosystem. SAV helps to stabilize sediments that enter the system and to deter shoreline erosion. The submerged macrophytes serve as filters, improving the quality of the water column by removing many pollutants and dissolved nutrients (Clark, et al., 1973; and Stevenson, et al., 1979). These aquatic plants provide important habitats for a variety of wildlife species, which use the grass beds for shelter, feeding and breeding areas. SAV is a major primary producer in the food chain associated within the aquatic and adjoining upland habitats. The added physical characteristics of the plants within the aquatic environment allow for a greater diversity of wildlife species, when compared to habitats not supporting SAV (Stevenson & Confer, 1978)

4,4′-Diiodo-3,3′-dimethoxy­biphen­yl

The mol­ecules of the title compound, C14H12I2O2, lie on inversion centers and are linked by I⋯O inter­actions with inter­molecular distances of 3.324 (3) Å. The aromatic rings display no significant inter­calation or stacking inter­actions

Prescribed Fire Impacts to Amphibians and Reptiles in Shelterwood-harvested Oak-dominated Forests

As part of a larger study examining the role of prescribed fire in regenerating upland oaks (Quercus spp.), seasonal prescribed burns (winter, spring, summer, and unburned control) were applied to first-stage shelterwood-harvested stands on Horsepen Wildlife Management Area in the Virginia Piedmont in 1995. Because fire impacts are poorly documented for herpetofaunal communities, we surveyed these stands in 1996 capturing 133 individuals of ten species during over 12,720 pitfall trapnights. We found no significant differences in relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus) (P = 0.26), American Toads (Bufo americanus) (P = 0.93), or all amphibians combined (P = 0.25) among unburned shelterwood stands and those treated with winter, spring, or summer burns. Three species of reptiles (Northern Fence Lizard [Sceloporus undulatus], Ground Skink [Scincella lateralis], and Southeastern Five-lined Skink [Eumeces inexpectatus]) combined were captured more frequently in burned versus unburned stands (P = 0.02). Based on a stepwise multiple regression model, Eastern Red-backed Salamander captures were more strongly influenced by landscape variables (P = 0.0320), including distance to permanent water and mesic (i.e., eastern-northern) aspects, than by fire treatments (P = 0.26). Similar landscape models were not significant (P \u3c 0.05) for toads or reptiles. Based on these results, prescribed fire may not be detrimental to herpetofaunal communities in oak dominated forests in the Virginia Piedmont

Correlated Response in Fatty Acid Composition after Five Generations of Selection for Intramuscular Fat in Duroc Pigs

After five generations of selection for IMF using realtime ultrasound, the select line pigs had more IMF. Selection for IMF has, however, resulted in slightly more backfat and less loin muscle area. A correlated response to selection for IMF has yielded a response in pork flavor and overall fatty acid composition. Genetic selection for IMF may be feasible without ramifications on nutritional value of pork

Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics, trophic interactions and fish community structure