Atmosphere Behavior in Gas-Closed Mouse-Algal Systems: An Experimental and Modelling Study

A dual approach of mathematical modelling and laboratory experimentation aimed at examining the gas exchange characteristics of artificial animal/plant systems closed to the ambient atmosphere was initiated. The development of control techniques and management strategies for maintaining the atmospheric levels of carbon dioxide and oxygen at physiological levels is examined. A mathematical model simulating the atmospheric behavior in these systems was developed and an experimental gas closed system was constructed. These systems are described and preliminary results are presented

Cost-Effective Engineering of a Small-Scale Bioreactor

Several methods exist for increasing the scale of cell culture in the laboratory. While these methods provide significant increases in biomass, they are often prohibitively expensive for many laboratories. We have engineered a small-scale bioreactor with a novel means of introducing oxygen through the catalytic breakdown of hydrogen peroxide using a manganese oxide catalyst. We have also adapted and modified an existing assay for dissolved oxygen to be compatible with culture conditions. In this system we have been able to culture CHO cells at densities of up to 107 cells/mL without the use of automated feedback systems

Survey Atlas of England and Wales

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Factors Affecting Italian Ryegrass (\u3cem\u3eLolium multiflorum\u3c/em\u3e L.) Seed Distribution

Italian ryegrass (Lolium multiflorum L.) can be a productive and high-quality cool-season forage in the Southern Great Plains of the U.S.A, if it is managed to produce sufficient seed for effective reestablishment without compromising forage yield. Before the re-seeding dynamics of Italian ryegrass can be modeled an understanding of seed production, seed-shed, and seed dispersal is necessary. Here two factors affecting Italian ryegrass seed dispersal and distribution are examined – wind and cultivation practice (mowing and raking)

The Effect of Harvest Management on Forage Production and Self-Reseeding Potential of Italian Ryegrass (Lolium Multiflorum L.)

Italian ryegrass (Lolium multiflorum L.) (IRG) can be managed to produce a seed output sufficient for effective re-establishment, without compromising forage yield, it may provide an alternative to perennial cool-season grasses in the Southern Great Plains of the U.S.A. The reduction in cost of replanting and avoidance of cultivation offered by a self-seeding crop may be particularly useful in low-input production systems. We examined the effect of dates of initial harvest in spring and of partial harvests on forage yield, seed output and re-establishment of Italian ryegrass

The Enigma of the “Jumping Frenchmen of Maine”

The “Jumping Frenchmen of Maine” exhibited unusual reactions when startled, and they became a component of local folklore in northern New England during the late nineteenth century. Medical scientists of the time examined the condition, but came to no definite conclusions. Modern scientists in the late twentieth century also disagreed on its origins. The syndrome appears to have resulted from the unique social and environmental factors peculiar to the logging camps of the time. Stephen R. Whalen has a Ph.D. in history from the University of Maine. Retired from public school teaching, he is currently a member of the History Department at Castleton State College in Castleton, Vermont. Robert E. Bartholomew, a former journalist in New York state, has a Ph.D. from James Cook University in Australia. He is the author of LITTLE GREEN MEN, MEOWING NUNS AND HEADHUNTING PANICS: A STUDY OF MASS PSYCHOGENIC ILLNESS AND SOCIAL DELUSION (Mc- Farland, 2001)

Overseeding Unimproved Warm-Season Pasture with Cool- and Warm-Season Legumes to Enhance Forage Productivity

Overseeding forage legumes into existing warm-season pasture may help to reduce cool-season forage deficit on small and resource-limited small farms in the southern Great Plains of the United States. Unimproved warm-season grass pastures were overseeded with Korean lespedeza (Lespedeza stipulacea Maxim) were not overseeded with summer legume. These same plots were subsequently overseeded with hairy vetch (Vicia villosa Roth), crownvetch (Coronilla varia L.), black medic (Medicago lupulina L.) or ladino white clover (Trifolium repens L.) or, not overseeded with cool-season legume. Including lespedeza in a forage mixture increased total forage yield by an average of 15%, or 1700 kg ha-1 over 4 years. Overseeding with cool-season legumes provided a net benefit in total annual forage yield of 0.75 kg for each 1.0 kg of legume produced. Yield increases resulting from overseeding with hairy vetch or black medic were largely limited to the harvest season following sowing, while overseeded crownvetch or white clover provided limited short- to medium-term yield benefit. Improvement of low-productivity pasture resulting from legume introduction is likely to be slow and will require sustained management input to ensure the presence of a productive legume plant stand

Growth of Stocker Channel Catfish to Large Market Size in Single-Batch Culture

Catfish farmers increasingly are producing fish larger than the traditional size of 0.45-0.57 kg/fish in order to meet processing plant requirements for larger fish. Production of larger channel catfish (Ictalurus punctatus) in multiple-batch culture has been investigated in a few studies, but the impact of understocked fingerlings on growth of carry-over fish is unknown. The present study was conducted to quantify growth, feed conversion ratio, net daily yield, and net and total yield of stocker channel catfish grown in single-batch, one-season culture to mean individual weights of 0.60, 0.72, 0.91, or 1.17 kg/fish. Channel catfish (mean weight = 0.26 kg/fish) were stocked into 12 0.1-ha ponds at 11,115 fish/ha. Fish were fed a 32% crude protein floating extruded feed once daily to apparent satiation. When the average weight of the fish population reached the target weight, three randomly selected ponds were harvested. Fish growth was linear in all treatments. Growth rates were similar for fish grown to 0.60, 0.72, and 0.91 kg/fish, and significantly lower (P \u3c 0.05) than for fish grown to 1.17 kg. Variation in individual fish weight increased linearly with increased duration of culture period. Feed conversion ratio averaged 1.9 and did not differ significantly among treatments. The percentage of the fish population at harvest that fell within the 0.57 to 2.04 kg-size range preferred by processing plants increased from 56.6 to 98.5% as the mean weight at harvest increased from 0.60 to 1.17 kg/fish