Showing papers by "Mississippi State University published in 1981"

Heat stress as it affects animal production.

Abstract: It is well documented that the stress of hot environments lowers productive and reproductive efficiency, in farm animals. Likewise, research information is available to aid in the management of livestock in such adverse conditions. However, practical methods to achieve the desired levels of productive and reproductive performance are lacking. Summer forages that will support a high level of productivity in subtropic and tropic regions are needed for ruminants. More critical information is needed on the total dietary needs of all farm animals in hot environments. Dietary emphasis should be to increase intake or to alter levels of proteins, amino acids or other nutrients to improve the conversion of feed units into production units. Increasing nutrient intake to support a higher level of production will render animals more sensitive, in terms of productive efficiency, to environmental modifications that improve comfort. This should be especially pertinent in the humid Southeast and other regions where production responses to environmental modifications have been variable. There is limited information on the effect of the night cooling cycle on productive efficiency and on the effect of severe heat stress on reproductive phenomena not related to conception.

Distribution of iron-containing superoxide dismutase in vascular plants.

Abstract: Superoxide dismutases (EC 11511) in vascular plants representing different evolutionary levels were characterized using polyacrylamide gel electrophoresis The three forms of the enzyme were distinguished from each other based on the following criteria: a) the Cu-Zn enzyme is sensitive to cyanide wherease the Fe and Mn enzymes are not; and b) the Cu-Zn and Fe enzymes are inhibited by H2O2 whereas the Mn enzyme is H2O2-resistant Of the 43 plant families investigated, the Fe-containing superoxide dismutase was found in three families: Gingkoaceae, Nymphaceae, and Cruciferae

Apparent and true availability of amino acids from common feed ingredients for channel catfish.

Abstract: The apparent and true amino acid availability values for corn, wheat middlings, rice bran, rice mill feed, soybean meal, peanut meal, cottonseed meal, meat and bone meal, and two different samples of menhaden fish meal were determined in adult channel catfish. Although there was reasonable agreement between protein digestibility values and average amino acid availability values, individual amino acid availabilities were variable within and among the various feed ingredients tested. Therefore, we recommended that amino acid availability values should be used for more accurate catfish feed formulation. In addition, it appears that the use of true amino acid availability values should be used for feed ingredients of relatively low protein content.

Arginine Requirement and Apparent Absence of a Lysine-Arginine Antagonist in Fingerling Channel Catfish

Abstract: A series of growth studies, utilizing casein-gelatin based diets supplemented with crystalline amino acids, were conducted to determine the arginine requirement for fingerling channel catfish (Ictalurus punctatus) and to evaluate the effects of excessive levels of dietary lysine and arginine Weight gain and feed efficiency data indicate the arginine requirement to be 103 +/- 007% and 100 +/- 006% of the dry diet, respectively Based on growth this corresponds to 429% of the dietary protein There was no evidence of an arginine-lysine antagonism when excess lysine was fed in diets adequate or marginal in arginine Similarly, growth and feed efficiency data suggest the lack of an antagonism when excess arginine is added to diets marginal in lysine Apparently channel catfish are not as sensitive to disproportionate lysine and arginine levels as are other animals

Conservation form of the Navier-Stokes equations in general nonsteady coordinates

Abstract: Introduction R interest in the generation of general bodyoriented curvilinear coordinate systems," for the purpose of solving the complete Navier-Stokes system of equations for subsonic and supersonic flows, has given rise to many forms of presentations of the equations both in conservative and nonconservative formulations. Based on the available solutions of the gasdynamic equations (e.g., Ref. 5) the conservation-law form of the equations seems definitely preferable, particularly when shocks are present. Although the above statement cannot be repeated in a definitive sense for the case of viscous subsonic and supersonic flow prediction through the Navier-Stokes equations, nevertheless, it is expected that the conservation-law form may eventually be more acceptable for numerical purposes. The purpose of this paper is to derive the conservation-law form of the Navier-Stokes equations in general nonsteady coordinate systems in a simple and direct fashion. Previous work on this subject has been done by McVittie, Viviand, and Vinokur. It will be shown in this Note that the equations in the conservation-law form can be obtained simply by a little manipulation of some standard vector and tensor formulas.

Tomorrow is Another Day: The Woman Writer in the South, 1859--1936

Abstract: From the mid-nineteenth century through at least the first half of the twentieth, the southern code of appropriate feminine behavior required that women depend on sources outside themselves for sustenance, direction, and expression. The chivalric ideal that placed the southern lady on a pedestal often created within her gracious and gentle exterior a turmoil of frustration, confusion, and resentment. This concept of upper middle-class, white southern womanhood forms an important part of the imaginative expression of the southern women writers whose works and lives form the subject matter of this book. All seven, Augusta Jane Evans, Grace King, Kate Chopin, Mary Johnston, Ellen Glasgow, Frances Newman, and Margaret Mitchell, were themselves products of this genteel tradition. Anne Goodwyn Jones explains that her aim is not to link biography and art but to seek, in the lives and works of these seven southern women writers, common patterns that can lead to ways to discern the mind of the southern lady. Tomorrow Is Another Day shows that, by writing themselves and their characters into being, by expressing their voices, however variant in tone, ""these seven writers wrote themselves into another day.

Chemiluminescence in Wounded Root Tissue : EVIDENCE FOR PEROXIDASE INVOLVEMENT.

Abstract: Root and stem segments from soybean (Merrill cv. `Bragg9) showed an enhanced chemiluminescence upon mechanical injury. Roots emitted more light than did stems. Light emission was diminished by CN − and N 3 − but was not affected by rotenone and antimycin A. Catalase quenched chemiluminescence in wounded root segments as did ascorbic acid and hydroquinone. Superoxide dismutase addition resulted in a small diminution in light emission, but mannitol, an OH· scavenger, was without effect. The addition of H 2 O 2 to wounded root segments markedly elevated chemiluminescence in the presence of air as well as under N 2 . It is concluded that peroxidases, found abundantly in roots, predominantly contribute to light emission in wounded plant tissue.

Calculation of Turbulent Boundary Layers with Separation and Viscous-Inviscid Interaction

Abstract: A method is presented for calculating turbulent boundary layers with separation, reattachment, and viscousinviscid interaction. The boundary-layer method is a two-dimensional planar or axisymmetric inverse integral technique based on an analytical description of attached and separated turbulent boundary-layer velocity profiles. The inviscid region is calculated using a time-dependent, three-dimensional, finite-volume Euler equation code. Viscous-inviscid interaction is achieved using the surface source model. Transonic viscousinviscid interacting flows over planar, axisymmetric, and three-dimensional configurations are calculated and compared with experimental data.

Effect of pH on TBA Values of Ground Raw Poultry Meat

Abstract: Hand-deboned raw broiler meat was ground through a meat grinder and adjusted to pH values of approximately 3, 5, 7, and 9. The prepared samples along with the controls were covered and stored at 2–4°C. The 2-thiobarbituric acid (TBA) values of the samples were measured immediately after sample preparation and during refrigeration storage for a period of 14 days. The pH values affected the lipid oxidation of ground raw meat as measured by the TBA test. The lower the pH values, the stronger pro-oxidant affect. Adjusting the pH values of ground raw poultry meat to neutral or alkaline slowed the increase in TBA values.

Balance Theory and Political Cognitions

Abstract: The CPS 1972-1976 panel is employed to test numerous principles of balance theory on Americans' political cognitions. Evidential support is found for Heider's original formulation of balance theory pertaining to dichotomous variables comprising a triad and extensions of this theory to structures of more than three cognitions, and variables measured at the interval level. Political reality effects, rational policy evaluation processes, and alternative psychological perspectives cannot adequately explain our data patterns. Other findings are: people attain balance in diverse ways by changing any of their cognitions; the more politically sophisticated are more affected by balance processes; balance theory has implications for the vote decision. The implications of the study for the nature of American democracy are also addressed.

Porcine superoxide dismutase. Isolation and characterization of a relatively basic cuprozinc enzyme.

Abstract: A cuprozinc superoxide dismutase has been isolated from pig liver. The enzyme is similar to previously described cuprozinc superoxide dismutases in that it is a dimer of about 32 000 molecular weight consisting of approximately two equally sized subunits, and 2 atoms of copper and two atoms of zinc per molecule. It differs, however, from previously described cuprozinc superoxide dismutases because of its higher isoelectric point; pI 6.8 vs 4.9 for bovine enzyme. The diffusion coefficient for the porcine enzyme was determined to be 7.53×10−7 cm2s−1, while the equivalent spherical hydrodynamic radius was computed as 28.5 A. The enzyme was observed to undergo self-association with time. Sulfhydryl interaction is postulated to be involved.

Lymphopoiesis in the chicken pineal gland.

Abstract: Pineal lymphoid development was studied in two breeds of chickens from hatching until sexual maturity. No lymphocytes were found in the pineal prior to 9 days of age (da). Lymphocytes migrate through the endothelium of venules into the pineal stroma. Lymphoid tissue reached its maximal accumulation in 32-da pineal glands of both breeds. At this age, the New Hampshire (NH) breed had a larger proportion of lymphoid volume to total pineal volume (32%) than did pineal glands from White Leghorn (WL) chickens (18%).

Sunlight-skin cancer association in the dog: a report of three cases.

Abstract: Squamous cell carcinoma is one of the most frequently recognized neoplastic diseases of the canine integument, although few risk factors influencing tumor development have been clearly defined. Three dogs with cutaneous squamous cell carcinomas are reported. Tumors developed in lightly-pigmented, glabrous following chronic sunlight exposure and long period of dermatosis. Microscopic examination of tissues from the three dogs showed progressive development of epithelial hyperplasia through stages of solar keratosis-like lesions to invasive and metastatic squamous cell carcinoma.

Cholesterol kinetic analyses in copper-deficient rats.

Abstract: Ninety weanling male Sprague-Dawley rats were randomly allotted into two treatment groups (copper-deficient and adequate; less than 2 mg and 8 mg Cu/kg of diet. Feed and distilled water were provided ad libitum for 16 weeks. After 5 weeks of treatment, the rats were injected intraperitoneally with 6.35 microCI [4-14C]cholesterol/kg body weight. A disappearance curve of the serum cholesterol specific activity (SA) was obtained for each treatment group by killing one animal at 1, 2, 7, 14, 28, 42, 56, 70 and 77 days after the tracer injection. Disappearance curves of serum cholesterol SA were constructed for the rats fed the copper-adequate and copper-deficient diets. Each disappearance curve of cholesterol SA in the serum was subjected to a kinetic two-pool analysis. The size of the fast turning over cholesterol pool (pool A) and the half-life of pool A were significantly greater in rats fed the copper-deficient diet than the controls. In addition, copper deficiency decreased the rate of removal of cholesterol from pool A (KAA), decreased the irreversible removal of cholesterol from pool A (KA) and reduced the rate of transport of cholesterol (KAB) from pool A to the slowly exchangeable pool (pool B). However, copper deficiency did not alter the production rate of cholesterol (PRA) in pool A. Thus, the reduction in the rate of removal of cholesterol from pool A might have been responsible for the hypercholesterolemia observed previously in rats fed copper-deficient diets.

Predatory behavior of the clerid beetle thanasimus dubius (coleoptera: cleridae) on the southern pine beetle (coleoptera: scolytidae)

Abstract: The behavior of adults of clerid beetle Thanasimus dubius (F.) preying upon adult southern pine beetles, Dendroctonus frontalis Zimmerman, in an arena in the laboratory is described by classifying the acts according to their consequences. A sequence of five stereotyped acts is performed by the predator: either searching or ambush, seizure of prey, alignment of prey, consumption of prey, and grooming. Handling time by the predator consists of the sums of the durations of the four acts of seizure through grooming, which was not significantly different for male and female predators, but was significantly longer for male prey (13.81 min) than for female prey (10.49 min). Consumption of prey (8–9 min) is the major component of handling time. Predators searched or waited in ambush an average of 5.8 mm before seizing a prey, and captured prey with an efficiency of 72%. Blinding predators had no significant effect on their efficiency at capturing prey. Maxillary and labial palpectomy alone or in combination significantly reduced efficiency of capture, and reduced numbers of prey consumed.

Effects of canopy removal and nitrogen enrichment on a Distichlis spicata-edaphic diatom complex

Abstract: Edaphic diatoms were collected seasonally from a monotypic stand of Distichlis spicata (L.) Greene on Graveline Bay Marsh, Mississippi, in which the marsh surface had been enriched with NH 4 Cl and exposed to high light intensity by clipping the grass shoots. Clipping greatly reduced species diversity ( H′ ) and the number of taxa in a sample ( S ) in all seasons except winter, but did not stimulate the growth of filamentous algae. Nitrogen enrichment increased H′ and S in spring. Of the 111 taxa encountered, clipping eliminated nine pre-existing texa and introduced three new taxa into the community. No such effect was induced by nitrogen enrichment. A 3-way ANOVA (light×nitrogen×date) of the relative abundances of the 16 most abundant taxa revealed that 11 taxa were characterized by a significant 3-way interaction term. As with community diversity, effects due to clipping were more prevalent than those due to nitrogen enrichment. When all responses were considered, the specific combination of clipping and NH 4 Cl enrichment had for all practical purposes the same effects on community structure as did clipping alone. Nitrogen enrichment greatly stimulated the aerial yield of intact D. spicata stands and the regrowth of those clipped 3 months earlier.

The Uniqueness of Phase Retrieval from Intensity Measurements.

Abstract: The question of the uniqueness of the determination of the phase of a wave field from the knowledge of its intensity in the aperture plane and focal plane of a thin lens is investigated. It is shown that if the wave field intensity across the lens is uniform and the phase is represented by means of nine lowest-order Zernike polynomials, the phase can be determined uniquely (except for the well-known twin solution ambiguity) from its aperture-plane and focal-plane intensities. The twin ambiguity is discussed in physical terms that allow one to eliminate it.

Changes in the characteristics of potting media with time

Abstract: Growing media for container plants composed of pine bark, peat and sand were evaluated before, during and after five months with ryegrass as the test plant in the greenhouse. Hydraulic conductivity of these materials is very rapid resulting in rapid loss of nutrients, even for the controlled‐release type fertilizers. Channels developed on the perimeter of the growing medium ball adjacent to the container wall resulting in a concentration of plant roots in this zone. Considerable shrinkage or compaction of the media occurred during the five months growth period, especially for peat. Movement of sand was observed for the very porous materials and found to accumulate as a layer lower in the container. All nutrients added were exhausted after 3 months, even for the controlled‐release types of fertilizers.

A scanning electron microscopic study of the molar surfaces of the mandibles of the brine shrimp (Cl. Branchiopoda: O. Anostraca).

Abstract: Scanning electron microscopy was used to characterize the external morphology of the molar surface of the mandibles of the brine shrimp, Artemia salina. Unlike many other branchiopod crustaceans, Artemia has symmetrical mandibles, ie, the molar surfaces of the two mandibles of an individual are similar in size and surface structure. Each molar area has three basic regions: the anterio-ventral region, posterio-dorsal region, and transition zone. On the anterio-ventral region there are complex, parallel furrows and ridges, which are specializations for clasping masses of fine, particulate food. The general surface of this ridged area is flat, except at the ventral and anterior edges, where there is a fringe of long projections that probably serve to retain food in the space between the paired mandibles. The posterio-dorsal region, which has simpler, more sparse cuticular projections, is adapted for reception of food. Stereomicrographs reveal that the general surface of this region is sloped and thus forms a cleft along the posterio-dorsal margin of the two apposed molar surfaces. Anatomical relstionships suggest that the cleft is an adaptation for accommodating maxillular setae that push food forward onto the mandibles. The transition zone has cuticular specializations that are morphologically intermediate between those of the anterio-ventral and posterio-dorsal regions. Three types of pores, possibly openings of glands or sensilla, were observed in the cuticle of the molar surface.