Crossbreeding hogs for pork production

Some 11 or 12 million slaughter hogs are produced on Iowa farms each year. The sale of these hogs produces the largest single item (about 40 percent) of the annual farm income of the state. Any procedure that will produce these hogs more efficiently will increase the net income o f the farmer who uses it, as well as that of the state as a whole

Impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH by Sclerotinia sclerotiorum

Sclerotinia sclerotiorum D-E7 was studied to determine the impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH in broth media (initial pH c. 5). Cultures with 0.1% nutritional supplement (tryptone, yeast extract, or soytone) yielded minimal growth, 2–3 mM oxalate, and a final culture pH of 4.2–4.8. In contrast, cultures with 0.1% nutritional supplement and 25 mM glucose yielded significant growth, minimal oxalate (\u3c1 mM), and a final culture pH of 2.8–3.7. Similar trends were observed when glucose in 0.1% soytone cultures was replaced with 25 mM d-mannose, l-arabinose, or d-xylose. With 1% soytone-25 mM glucose cultures, growth and oxalate accumulation (∼21 mM) occurred with little change in initial pH. This was not the case with 1% soytone-250 mM glucose cultures; increased glucose levels resulted in a decrease in oxalate accumulation (∼7 mM) and in final culture pH (3.4). Time-course studies with these cultures revealed that oxalate accumulation was suppressed during growth when the culture pH dropped to \u3c4. Overall, these results indicate that (1) the decrease in external pH (i.e. acidification) was independent of oxalate accumulation and (2) acidification coupled to glucose-dependent growth regulated oxalate accumulation by Sclerotinia sclerotiorum

Summary of alluvial-channel data from Rio Grande conveyance channel, New Mexico, 1965-69

August 1971.CER71-72JPB30.Includes bibliographical references (pages 48-50)

Soft ear corn silage for swine

A recurrence of soft corn years in the last quarter century brings into prominence the question of what should be done with this perishable product, which is often large in amount. Owing to the limited investigational work which has been carried on along this line and because of the numerous inquiries received in regard to the best way of handling, preserving and feeding soft corn, it was thought advisable to make some definite determinations of the keeping and feeding qualities of various grades of corn. Inasmuch as soft corn is corn which has been frosted before its kernels have reached maturity, it often contains an abnormally large amount of moisture, the water percentage being the largest in the most immature com

Impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH by Sclerotinia sclerotiorum

Sclerotinia sclerotiorum D-E7 was studied to determine the impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH in broth media (initial pH c. 5). Cultures with 0.1% nutritional supplement (tryptone, yeast extract, or soytone) yielded minimal growth, 2–3 mM oxalate, and a final culture pH of 4.2–4.8. In contrast, cultures with 0.1% nutritional supplement and 25 mM glucose yielded significant growth, minimal oxalate (\u3c1 mM), and a final culture pH of 2.8–3.7. Similar trends were observed when glucose in 0.1% soytone cultures was replaced with 25 mM d-mannose, l-arabinose, or d-xylose. With 1% soytone-25 mM glucose cultures, growth and oxalate accumulation (∼21 mM) occurred with little change in initial pH. This was not the case with 1% soytone-250 mM glucose cultures; increased glucose levels resulted in a decrease in oxalate accumulation (∼7 mM) and in final culture pH (3.4). Time-course studies with these cultures revealed that oxalate accumulation was suppressed during growth when the culture pH dropped to \u3c4. Overall, these results indicate that (1) the decrease in external pH (i.e. acidification) was independent of oxalate accumulation and (2) acidification coupled to glucose-dependent growth regulated oxalate accumulation by Sclerotinia sclerotiorum

Impact of carbon sources on growth and oxalate synthesis by the phytopathogenic fungus Sclerotinia sclerotiorum

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic potential, were dissimilar when the organism was grown in the presence of different carbon sources. The highest oxalate-to-biomass ratios were observed with pyruvate, formate, malate, acetate, and succinate. Time-course studies with acetate-supplemented cultures revealed that acetate and glucose consumption by S. sclerotiorum D-E7 coincided with oxalogenesis and culture acidification. By day 5 of incubation, oxalogenesis was halted when cultures reached a pH of 3 and were devoid of acetate. In succinate-supplemented cultures, oxalogenesis essentially paralleled glucose and succinate utilization over the 9-day incubation period; during this time period, culture pH declined but never fell below 4. Overall, these results indicate that carbon sources can regulate the accumulation of oxalate, a key pathogenicity determinant for S. sclerotiorum

Impact of carbon sources on growth and oxalate synthesis by the phytopathogenic fungus Sclerotinia sclerotiorum

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic potential, were dissimilar when the organism was grown in the presence of different carbon sources. The highest oxalate-to-biomass ratios were observed with pyruvate, formate, malate, acetate, and succinate. Time-course studies with acetate-supplemented cultures revealed that acetate and glucose consumption by S. sclerotiorum D-E7 coincided with oxalogenesis and culture acidification. By day 5 of incubation, oxalogenesis was halted when cultures reached a pH of 3 and were devoid of acetate. In succinate-supplemented cultures, oxalogenesis essentially paralleled glucose and succinate utilization over the 9-day incubation period; during this time period, culture pH declined but never fell below 4. Overall, these results indicate that carbon sources can regulate the accumulation of oxalate, a key pathogenicity determinant for S. sclerotiorum

AN ASSESSMENT OF MCNP WEIGHT WINDOWS

The weight window variance reduction method in the general-purpose Monte Carlo N-Particle radiation transport code MCNPTM has recently been rewritten. In particular, it is now possible to generate weight window importance functions on a superimposed mesh, eliminating the need to subdivide geometries for variance reduction purposes. Our assessment addresses the following questions: (1) Does the new MCNP4C treatment utilize weight windows as well as the former MCNP4B treatment? (2) Does the new MCNP4C weight window generator generate importance functions as well as MCNP4B? (3) How do superimposed mesh weight windows compare to cell-based weight windows? (4) What are the shortcomings of the new MCNP4C weight window generator? Our assessment was carried out with five neutron and photon shielding problems chosen for their demanding variance reduction requirements. The problems were an oil well logging problem, the Oak Ridge fusion shielding benchmark problem, a photon skyshine problem, an air-over-ground problem, and a sample problem for variance reduction