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Articles 1 - 4 of 4
Full-Text Articles in Animal Sciences
Crop/Livestock Integration Effects On Soil Quality, Crop Production, And Soil Nitrogen Dynamics, Ellen B. Mallory
Crop/Livestock Integration Effects On Soil Quality, Crop Production, And Soil Nitrogen Dynamics, Ellen B. Mallory
Electronic Theses and Dissertations
Regional integration of potato and dairy farms has developed in Maine through arrangements where manure, feed, and sometimes land, are exchanged between neighboring farms. The effects of integration on soil quality, crop production, nitrogen (N) cycling, and N loss were investigated in field and laboratory studies of contrasting amended (manure, compost, green manure, and supplemental fertilizer) and nonamended (fertilizer only) soil management systems within 2-year potato (Solanum tuberosum L.) rotations in the Maine Potato Cropping Systems Project (MPEP). Additionally, soil quality of 48 integrated and nonintegrated Maine potato and dairy farm fields was assessed. The MPEP’s amended soil system enhanced …
Mechanics Of Burrowing In Muddy Sediments, Kelly M. Dorgan
Mechanics Of Burrowing In Muddy Sediments, Kelly M. Dorgan
Electronic Theses and Dissertations
Marine muds are elastic solids through which animals move by propagating a crack-shaped burrow. Dilations previously considered anchors serve to exert dorsoventral compressive stresses on the burrow walls that, through elastic behavior of the medium, focus strongly at the tip of the burrow. This focused stress breaks adhesive or cohesive bonds, propagating a crack for the animal to follow. The force exerted by the polychaete, Nereis virens, to propagate a crack has been measured in gelatin, an analogue of muddy sediment, through photoelastic stress analysis. Finite element analysis was used to convert measured forces to those exerted in natural sediments …
The Long-Term Effects Of A Group-Selection Timber Harvest On The Bird Community Of An Oak-Pine Forest In Maine, Stephen P. Campbell
The Long-Term Effects Of A Group-Selection Timber Harvest On The Bird Community Of An Oak-Pine Forest In Maine, Stephen P. Campbell
Electronic Theses and Dissertations
Bird populations have been monitored at the Holt Research Forest in Arrowsic, Maine since 1983 as part of a long-term forest ecosystem study. In the winter of 1987-1988, 10 ha of the 40-ha study area were subjected to a group-selection timber harvest (i.e., a harvest that creates canopy gaps by removing small groups of trees). I analyzed the first 20 years of these data (5 years of pre-harvest data and 15 years of post-harvest data) for changes in abundance and spatial distribution of birds in response to the harvest. Although species’ responses to the group-selection harvest were idiosyncratic, two general …
Assessment Of The Flame Angelfish (Centropyge Loriculus) As A Model Species In Studies On Egg And Larval Quality In Marine Fishes, Chatham K. Callan
Assessment Of The Flame Angelfish (Centropyge Loriculus) As A Model Species In Studies On Egg And Larval Quality In Marine Fishes, Chatham K. Callan
Electronic Theses and Dissertations
This project sought to determine if flame angelfish (Centropyge loriculus) could serve as models in examination of environmental and dietary effects on egg quality in marine fishes. Evaluation of 21 marine ornamental species identified flame angelfish as being amenable to egg quality research, due to their rapid conditioning and frequency of spawning. At the onset of this project, accidental copper introduction to broodstock systems required assays to determine the effects of copper exposure on survival and reproduction. Flame angelfish exhibited accute sensitivity to copper, as 60% of fish exposed to 0.25mg/L died within 12 hours of exposure. Likewise, fish exposed …