Showing papers by "Mississippi State University published in 1980"

Leucine, Isoleucine, Valine and Histidine Requirements of Fingerling Channel Catfish

Abstract: Growth studies were conducted with fingerling channel catfish to determine the minimal requirements for the amino acids leucine, isoleucine, valine and histidine. The experimental diets were formulated from purified ingredients to contain 24% crude protein and 275 kcal/100 g diet. Casein and gelatin served as protein sources and were supplemented with crystalline L-amino acids to provide the amino acid pattern found in 24% crude protein from whole egg powder. Based on dry diet the catfish required 0.84 +/- 0.04% leucine, 0.62 +/- 0.04% isoleucine, 0.71 +/- 0.03% valine and 0.37 +/- 0.01% histidine. These values correspond to 3.50% leucine, 2.58% isoleucine 2.96% valine and 1.54% histidine when expressed as a percentage of dietary protein. Quantitation of serum free amino acid levels revealed a marked increase in valine and isoleucine in leucine-deficient fish. In addition, increases in dietary isoleucine or valine resulted in changes in the serum levels of isoleucine, valine and leucine. These data indicate an apparent interaction among these amino acids in the catfish comparable to that previously observed in other species. Dietary histidine caused no increase in serum free histidine levels until the dietary requirement was reached. Muscle carnosine could not be detected in the catfish.

Re-evaluation of the lysine requirement and lysine utilization by fingerling channel catfish.

Abstract: Studies were conducted to reassess the lysine requirement for fingerling channel catfish and to evaluate the effects of feeding lysine-supplemented diets. Based on growth studies, utilizing casein and gelatin diets supplemented with crystalline L-amino acids to correspond to the pattern of 30% whole egg protein, the lysine requirement for fingerling channel catfish is approximately 1.5% of the dry diet or 5.0% of the dietary protein which confirms the previously reported lysine requirement. Contrary to prior reports, growth and feed efficiency data from studies using peanut meal diets (formulated to be first limiting in lysine) supplemented with feed grade lysine, demonstrate that fingerling channel catfish are able to utilize free amino acids effectively.

Universal Compression Index Equation

Abstract: An expression is developed empirically which relates virgin compression index with instantaneous zero-air-voids curve slope, and which is applicable to saturated sedimented fine grain soils of a given value of specific gravity regardless of stress history It is based on: (1)The assertion that field consolidation curves are relatively parallel for a given value of void ratio; and (2)on the fact that the consolidation processes of saturated fine-grain soils having the same specific gravity can be characterized by a single zero-air-voids curve Consolidation test data, which were used to develop the expression, were obtained from US Army Corps of Engineers district and division offices in the United States An experiment is currently underway using a slurry-consolidometer to obtain field consolidation test results on pure clay specimens, the data of which is hoped will yield a more accurate expression for compression index

Sequential Folding of Transfer RNA. A Nuclear Magnetic Resonance Study of Successively Longer tRNA Fragments with a Common 5’ End

Abstract: Most folding studies on proteins and nucleic acids have been addressed to the transition between the folded and unfolded states of an intact molecule, where an entire residue sequence is present during the folding event. However, since these polymers are synthesized sequentially from one terminus to the other in vivo, their folding pathways may be influenced greatly by the sequential appearance of the residues as a function of time. The three-dimensional structure of yeast tRNAPhe in the crystalline state is correlated with 360 MHz proton nuclear magnetic resonances from three fragments plus an intact molecule of the tRNA that share a common 5’ end and are in a solution condition similar to that of the crystal structure. This has allowed identification of folded structures present in the fragments and presumably present in the growing tRNA molecule as it is being synthesized from the 5’ end. The experiments show that only the correct stems are formed in the fragments; no additional or competing helical region is produced. This suggests that in the biosynthesis of this tRNA, correct folding of helical stems occurs before the entire molecule is formed. Further, some of the tertiary interactions (hydrogen bonds) found in the crystal structure are also probably present before the synthesis is completed. These findings are generalized to consider the precursor of the tRNA as well as other tRNAs.

On the Response of a Terminated Twisted-Wire Cable Excited by a Plane-Wave Electromagnetic Field

Abstract: The currents induced in the terminations of a twisted-pair cable are obtained for a plane-wave electromagnetic-field. Various termination configurations are considered and comparisons are made with the corresponding results for untwisted pairs. In special cases, the twisted cable may have a larger induced signal than the untwisted. Under various common restrictions, the induced signal is inversely proportional to either 1) the square of the number of turns or 2) the number of turns.

Total Aromatic Amino Acid Requirement, Phenylalanine Requirement and Tyrosine Replacement Value for Fingerling Channel Catfish

Abstract: A series of experiments was conducted to determine the aromatic amino acid requirement, the tyrosine replacement value for phenylalanine and the phenylalanine requirement under conditions of adequate tyrosine for fingerling channel catfish. Effects of excessive dietary levels of tyrosine were also investigated. The studies were conducted utilizing casein and gelatinbased diets supplemented with crystalline L-amino acids to correspond to the pattern of 24% whole egg protein. Based on 8-week growth studies, the total dietary aromatic amino acid requirement for fingerling channel catfish was approximately 1.20 +/- 0.06% (50% of the dietary protein) of which about 50% could be supplied by tyrosine. The phenylalanine requirement per se, based on growth and feed efficiency, was determined to be 0.47 +/- 0.02% and 0.49 +/- 0.02%, respectively. High dietary levels of tyrosine (up to 10%) did not adversely affect performance of fingerling channel catfish. It appears that neither serum-free phenylalanine nor serum-free tyrosine can be used to accurately predict dietary aromatic amino acid adequacy for the fingerling channel catfish.

Vibrational spectra and conformations of (chloromethyl)cyclopropane and epichlorohydrin

Abstract: The IR and Raman spectra (4000–50 cm−1) of (chloromethyl)cyclopropane and epichlorohydrin have been recorded in all three physical states. It has been concluded from the spectroscopic data and from variable temperature studies that (chloromethyl)cyclopropane exists as an equilibrium mixture of gauche (95%) and cis (5%) conformers in the liquid state, while only the gauche form persists in the solid phase. The enthalpy difference between these two rotamers was found to be 1.40±0.10 kcal mol−1. Similarly, epichlorohydrin has also been shown to exist as an equilibrium mixture of gauche-1 (70%), gauche-2 (21%) and cis (9%) conformers in the liquid state, with only the gauche-1 form remaining in the solid phase. Enthalpy differences among these conformers were determined to be 1.2±0.2 kcal mol−1 (gauche-1 vs. cis) and 0.70±0.10 kcal mol−1 (gauche-1 vs gauche-2). Apparently steric repulsions between the chlorine atom and β ring-hydrogens destabilize the cis conformation in each molecule. For each molecule, a vibrational assignment has also been proposed.

Ultrastructure of the labial tip sensilla of the tarnished plant bug, Lygus lineolaris (P. de Beauvois) (Hemiptera : Miridae)

Abstract: Sensilla on the labial tip of the tarnished plant bug, Lygus lineolaris, were examined with scanning and transmission electron microscopy in order to provide morphological evidence indicative of their function. The tripartate apex of the labium consists of 2 lateral lobes and an apical plate. Each lateral lobe possesses a field of 11 thick-walled, uniporous peg sensilla, 5–6 μm long and a thick-walled, nonporous hair sensillum, 18–22 μm long. The uniporous peg sensilla are innervated by 3 or 5 bipolar neurons. The nonporous hair sensillum has no dendrites within its lumen. The apical plate is a noninnervated structure which possesses terminal cuticular projections 5–8 μm long. Morphological evidence supports previously reported physiological evidence that the uniporous peg sensilla have a chemosensory function.

Effects of zinc deficiency on dental caries in rats.

Abstract: The effects of graded levels of dietary zinc on the development and mineralization of teeth and bones and on the susceptibility of teeth to dental caries were studied in young growing rats. Thirty-six weanling male Sprague-Dawley rats were randomly assigned to four dietary treatments: 1) zinc-deficient, less than 1 ppm; 2) 12 ppm zinc; 3) 36 ppm zinc, and 4) 108 ppm zinc. For treatments 2, 3 and 4, rats were pair-fed the quantity of feed consumed by their individual counterparts fed the zinc-deficient diet. After 4 weeks of treatment, growth retardation along with other clinical zinc deficiency signs were observed in rats fed the zinc-deficient diet. The zinc levels in bones and teeth of zinc-deficient rats were lower than those for rats fed supplemental zinc. Increased dietary zinc resulted in greater levels of zinc in bones and teeth, but the levels of calcium decreased. Greater incidences of enamel lesions in mandibular molars were observed in rats fed the zinc-deficient diet than in rats pair-fed zinc-supplemented diets. Furthermore, the effect of zinc deficiency on dental caries of young rats was predominantly at the smooth surfaces of the molars. Dietary zinc may be an important trace mineral in the process of post-eruptive mineralization of the enamel and may reduce the susceptibility of teeth to caries.

Interrelations between selected soil characteristics and arylsulfatase and urease activities

Abstract: Six field sites in western Oregon were examined periodically over one year for arylsulfatase and urease activities as well as a variety of chemical and physical soil characteristics. Two of the sites were under forest vegetation, one was under native grasses and three were under clover/grass pasture. The interactions between the enzymatic activities and the variations in the soil characteristics were analyzed using a variety of statistical programs. Both enzymes were most highly correlated with soil organic matter content (r = 0.58 for arylsulfatase and r = 0.59 for urease). Multiple regression analysis indicated that the variability was partially accounted for by the soil parameters monitored (arylsulfatase r2 = 0.657, urease r2 = 0.509). Principal component analysis generated four factors which, when combined, accounted for 65% of the observed variation in both arylsulfatase and urease activity. Seasonal fluctuations were recorded for both of the enzymes and the levels of activity apparently fl...

Vibrational spectra and conformations of epifluorohydrin

Abstract: The infrared and Raman spectra of solid, liquid and gaseous epifluorohydrin have been recorded. For the fluid phases, there are a number of spectral triplets which can be interpreted as arising from a cis and two nonequivalent gauche conformations. The number of bands which disappear as the solid sample is annealed indicates that a single conformation exists in the crystalline state. The temperature dependence of the intensities of Raman lines for the liquid state is consistent with enthalpy differences of approximately 0.6 and 0.4 kcal mol−1 between the most stable and each of the less stable conformers. The existence and identities of the less stable conformers are discussed.

Biology of the Fall Armyworm on Four Varieties of Bermudagrass When Held at Constant Temperatures

Abstract: Fall armyworm, Spodoprera frugiperda (Smith) larvae were reared in the laboratory on foliage on 4 varieties of bermudagrass, (“Alicia”, “Callie”, “Coastal”, and common), at 3 constant temperatures (20°, 25° and 30°C). Studies were designed to measure the effect of these 4 bermudagrass varieties and temperature on the biology of the insect. Differences in length of larval period, pupal weight, and length of pupal period, between grasses, were temperature and sometimes sex dependent. No significant differences were observed between grasses for egg production; however, significant differences were observed between temperatures. Larvae and pupae developed most rapidly at 30°C. Egg production was maximal at 25°C.

Small- and Large-Scale Field Tests of Erythrosin B for House Fly Control in Caged Layer Chicken Houses

Abstract: The xanthene dye, erythrosin B, was evaluated as a surface spray for control of the house fly, Musca domestica , in breeding areas under caged layer chickens. A weekly spraying of an aqueous solution of erythrosin B directly on chicken manure reduced house fly populations up to 94% in small-scale tests and 89% in a large-scale test. Larvae of the associated beneficial species, the soldier fly, Hermetia illucens , were not reduced by erythrosin B treatment. Approximately 80% of the erythrosin B was not recoverable from the manure after one wk.

Effect of supervisory evaluation on counselor trainees' anxiety.

Abstract: Counselor trainees frequently state that a counseling interview is more anxietyproducing when the interview is tape-recorded or evaluated by a practicum supervisor. A recent study (Bowman & Roberts, 1979) which assessed physiological and subjective measures of anxiety by experienced employment and rehabilitation counselors enrolled in an inservice practicum in counseling did not support this contention. Because the counselors' previous counseling experience might serve to reduce anxiety, the purpose of this study was to determine if tape recording or supervisory evaluation affected physiological and subjective anxiety levels of counselor trainees who had no previous counseling experience. Subjects were 14 female and 5 male counselor trainees enrolled in a graduate practicum. GSR and self-reports of anxiety were measured during three stimulus conditions: reading; counseling and tape-recording; and counseling. tape-recording, and subsequent evaluation. A counseling anxiery scale was administered at posttest to tap subjects' recall of awareness of their anxiety at three points during the sessions. Testretest reliability was .91; validity coefficient with the Spielberger State-Anxiety Inventory was .50. Each subject participated in all three conditions which provided a repeated-measures design. Data were analyzed using within-subjects analysis of variance. For GSR no significant differences were found among conditions: means and standard deviations were for reading 7.81 and 5.11, for counseling/reading 7.84 and 4.57, and for counseling/ recording/evaluation 9.49 and 4.46. For self-reported recall significant differences were found among conditions (FZn30 = 17.91, f i < .001). Newman-Keuls follow-up tests indicated that counseling/recording ( M = 3.25, SD = 1.77) was subjectively more anxiety-producing than reading ( M = 1.97, SD = 1.25), while counseling/recording/ evaluation ( M = 4.11, SD = 2.08) was subjectively more anxiety-producing than the other conditions. As these data are not consistent with Bowman and Roberts' (1979) findings, some support may be inferred for the role of cot~nseling experience in reducing counselor trainees' subjective experience of anxiety.