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Showing papers by "Mississippi State University published in 1973"


Journal ArticleDOI
TL;DR: In this article, a numerical method for the solution of the Navier-Stokes equations is developed using an integro-differential formulation of the equations, which permits the actual computation to be confined to the viscous region of the flow and offers a drastic reduction in the number of data points required in the numerical procedure.

181 citations



Journal ArticleDOI
TL;DR: In this paper, the authors compared some of the existing models to the Scheffe model in an attempt to provide the user with some guidance in the choice of an appropriate model, and the question of the correct expressions for the expected mean squares is also resolved.
Abstract: In his text on the analysis of variance, Sheffe (1959) presents a detailed development of the mixed model for two factors. The model, as initially described, appears to be quite general and is capable of accomodating a wide variety of experimental situations in which one factor is assumed fixed and the other random. Other authors have proposed different models which appear to differ from Scheff6's model in various ways. These models have been the subject of considerable discussion, with much of the controversy focusing on the expressions for the expected value of the mean square associated with the random factor. The purpose of this paper is to relate some of the existing models to the Scheffe model in an attempt to provide the user with some guidance in the choice of an appropriate model. The question of the correct expressions for the expected mean squares is also resolved. Although primary consideration is given to the relations between contending, infinite population models, one relation to the limiting form of the finite model is also noted. For ease of reference, the models are formally stated in Section 2. These statements also contain the basic relations between the models. These relations are then discussed in Section 3, and in Section 4, the correct expressions for the expected means squares are given.

71 citations


Journal ArticleDOI
TL;DR: The enzymes involved in ascorbic acid synthesis are apparently lacking in the liver and kidney of both the blue and channel catfish, and the symptoms are described.
Abstract: 1. 1. Ascorbic acid deficiency has been demonstrated in the channel catfish and the symptoms are described. 2. 2. The enzymes involved in ascorbic acid synthesis are apparently lacking in the liver and kidney of both the blue and channel catfish.

68 citations


Journal ArticleDOI
01 Sep 1973-Ecology
TL;DR: The role of social rank in heterogeneous trap response by cotton rats (Sigmodon hispidus) was investigated, and social subordination appears to inhibit trap response in several ways.
Abstract: The role of social rank in heterogeneous trap response by cotton rats (Sigmodon hispidus) was investigated. Data from field and laboratory trapping indicate that dominant animals are more trap prone than are subordinates. Social subordination appears to inhibit trap response in several ways. Subordinate animals exhibit less exploratory activity and a neophobic response not shown by domnants. Low—ranking animals also tend to avoid traps treated with conspecific scent, whereas dominant animals do not.

67 citations


Journal ArticleDOI
TL;DR: In this article, the electromagnetic field penetration through small apertures is discussed for general aperture shapes and approximate expressions for the penetration fields are obtained for the region between two parallel, perfectly conducting plates.
Abstract: The electromagnetic field penetration through small apertures is discussed for general aperture shapes. Approximnate analytical expressions are obtained for the penetration fields. In particular the fields that penetrate a small aperture into the region between two parallel, perfectly conducting plates are determined and some numerical results are obtained.

38 citations


Journal ArticleDOI
TL;DR: The insecticide toxicity to crayfish was inversely proportional to treatment time of the worm prior to feeding, but it was directly proportional to insecticide concentration.
Abstract: Tubifieid worms, Branchiura sowerbyi Beddard, from the Mississippi delta region were bioassayed in 23 commercial insecticides (chlorinated hydrocarbons, organophosphates, and carbamates). Maximum concentrations of 15 insecticides (0.5 to 4.0 ppm at 21°C) failed to cause mortality in 72-hours exposure, but they produced reversible morphological changes of the worms. Variations in morphological changes occurred in response to an insecticide type rather than to concentration, and they may possibly be used for monitoring purposes. Insecticide toxicity was influenced also by temperature changes. The worms were extremely susceptible to dissolve chlorine in tap water (6-10 ppm) which caused complete disintegration of the body, leaving a residual black ring at the site of death. Insecticide-treated worms of known weight and treatment time were fed to crayfish, Procambarus clarkii Girard, and their mortality was recorded. The insecticide toxicity to crayfish was inversely proportional to treatment time of the worm prior to feeding, but it was directly proportional to insecticide concentration. Crayfish showed less in effects when they ate carbamate-treated worms, especially if the worms were exposed to the insecticide for a long time. Gas-chromatographic analyses of field-collected worms exhibited a high concentration of organochlorine compounds, especially DDT, DDD, and DDE. Trace amounts of toxaphene also were detected. Possible mechanisms of insecticide resistance in tubificids are discussed, including the effects of mud in reducing the bioactivity of various insecticides.

35 citations


Journal ArticleDOI
TL;DR: The liver and kidney arginases were activated by Mn2+ ions and exhibited Km values similar to those previously reported for ureotelic species.
Abstract: 1. 1. The activities of carbamyl phosphate synthetase, ornithine transcarbamylase, arginine synthetase system and arginase were measured in liver and kidney homogenates of cultured and native channel catfish. 2. 2. Significant levels of carbamyl phosphate synthetase, ornithine transcarbamylase and arginase were detected in liver tissue, whereas only ornithine transcarbamylase and arginase were detected in kidney tissue. 3. 3. The liver and kidney arginases were activated by Mn2+ ions and exhibited Km values similar to those previously reported for ureotelic species.

33 citations


Journal ArticleDOI
TL;DR: Polyphosphates were more effective in controlling the growth of micrococcus and staphylococcus, which were the principle microbial flora found on the surface of fresh dressed chicken.
Abstract: Hot water precooked chicken parts were consistently lower in bacterial count than the microwave energy cooked samples. The surviving bacteria on the hot water cooked samples belonged to either the genus Micrococcus or the genus Staphylococcus. All colonies were nonpigmented. However, in addition to those bacteria found on the water cooked samples, pigmented staphylococcus and occasionally Gram positive rods were present on the microwave energy cooked samples. Precooking chicken parts in hot 3% polyphosphates solution resulted in an almost sterile product. Polyphosphates were more effective in controlling the growth of micrococcus and staphylococcus, which were the principle microbial flora found on the surface of fresh dressed chicken.

32 citations


Journal ArticleDOI
TL;DR: Significant differences occurred in all three enzymes in certain tissues with values in the cultured fish being somewhat higher than those obtained in the native fish, due to differences in the diets of the two groups of fish.
Abstract: 1. 1. The activities of aspartate (AspT) and alanine (AlT) aminotransferases and glutamic dehydrogenase (GDH) were measured in various tissue homogenates of cultured and native channel catfish. 2. 2. AspT and AlT were detected in liver, kidney, gill, gut tract, heart, spleen and brain tissue. GDH was detected in all of the above tissues except brain. 3. 3. Significant differences occurred in all three enzymes in certain tissues with values in the cultured fish being somewhat higher than those obtained in the native fish. These differences may be due to differences in the diets of the two groups of fish.

30 citations


Journal ArticleDOI
TL;DR: Two types of polysaccharides were separated from the extracellularpolysaccharide produced by Anabaena flos-aquae A-37 by ion exchange chromatography.
Abstract: Two types of polysaccharides were separated from the extracellular polysaccharide produced by Anabaena flos-aquae A-37 by ion exchange chromatography. The neutral polysaccharide is composed of mainly glucose with minor amounts of xylose in a molar ratio of 8:1. Glucose is believed to constitute the polysaccharide core to which xylose is attached. The acidic polysaccharide is composed of glucose and uronic acid as the major monomers with equal amounts of xylose and ribose as the minor constituents. The molar ratio of the monomers found in the acidic polymer is 6:1:1:10 as glucose: xylose: ribose: uronic acid. Chemical analyses showed that the extracellular polysaccharide consists of more neutral polymer (62%) than the acidic polymer (38%).

Journal ArticleDOI
TL;DR: This paper showed that response cost and omission training plus response cost reduced responding signi-ficandy more rapidly than did omission training, although the effects of the former 2 procedures were not significantly different.
Abstract: In the present experiment humans received training on a variable-ratio reinforcement schedule and were then shifted to one of 4 response-elimination procedures: extinction training, omission training, response cost, or omission training plus response cost. Results indicated that response cost, omission training plus response cost, and omission training eliminated responding significantly faster than did extinction training. In addition, response cost and omission training plus response cost reduced responding signi-ficandy more rapidly than did omission training, although the effects of the former 2 procedures were not significantly different.

Journal ArticleDOI
TL;DR: Fluorescein mercuric acetate has been shown to be an irreversible inhibitor of calf liver sorbitol dehydrogenase and catalyzes a subtle conformational change not observed in the absence of the dye.

Journal ArticleDOI
TL;DR: In this paper, the authors compared the response-elimination properties of omission training with two types of extinction training following VI 20-sec. reinforcement training and found that omission training produced relatively more rapid and more complete response elimination than both extinction training techniques.
Abstract: The present study attempted to compare the response-elimination properties of omission training with 2 types of extinction training following VI 20-sec. reinforcement training. One group received conditioned reinforcers during response-elimination sessions, while the other was treated in the traditional manner. Omission training produced relatively more rapid and more complete response elimination than both extinction training techniques. Also, the extinction training procedure employing conditioned reinforcers resulted in faster but less durable response elimination than the traditional extinction training procedure.

Journal ArticleDOI
TL;DR: The superior male performance on formal tasks was interpreted in terms of a social role hypothesis and the limited scientific subject matter of the problems.
Abstract: Sixty-five undergraduates were tested on five formal thinking tasks and the verbal and figural sections of the Torrance Tests of Creative Thinking. The percentage of students operating at the formal level for three of the four ordinally scored formal problems was significantly above the 50% figure usually reported with a more intellectually representative sample of adolescents. It was suggested that the norms developed by Piaget for formal tasks were more suitable for a cognitively superior population. The low intercorrelations between formal tasks were reflected by the failure of a unified factor of the formal operations to emerge. The superior male performance on formal tasks was interpreted in terms of a social role hypothesis and the limited scientific subject matter of the problems.

Journal ArticleDOI
TL;DR: The caries inhibitory effect of self-applied acidulated phosphate fluoride paste and gel was evaluated in a three-year study of lifelong residents of communities in which the water supplies were deficient in fluoride.
Abstract: The caries inhibitory effect of self-applied acidulated phosphate fluoride paste and gel was evaluated in a three-year study. Annual examinations revealed significant caries inhibitory effects after two and three years that are attributed to the application of the fluoride gel but not the fluoride paste. No significant effect was found after the first year. Children in groups using the fluoride gel exhibited caries increments in DMF teeth and surfaces ranging from 22.1% to 24.8% less than children whose teeth were treated with the nonfluoride gel. Participants in this study were lifelong residents of communities in which the water supplies were deficient in fluoride.

Journal ArticleDOI
TL;DR: The essential oil of Juncus roemerianus was isolated by steam distillation with a yield of 0·01 % of the fresh grass as discussed by the authors, and analysis by combined GLC-MS gave evidence for the presence of 78 compounds.

Journal ArticleDOI
TL;DR: Field studies indicated that the percent of CPV infection in larvae originating from virus-infected parents was density dependent, and the number of infected individuals as larvae reared in the customary way.

Journal ArticleDOI
TL;DR: In this article, the microwave spectrum of the molecular transient disulfur monoxide, S 2 O, has been reexamined and the microwave measurements have been extended into the millimeterwave region.

Journal ArticleDOI
TL;DR: Adult albino rats, previously overtrained on a brightness and a pattern discrimination habit, sustained bilateral lesions to the brainstem reticular formation and were subsequently tested for retention.
Abstract: Adult albino rats, previously overtrained on a brightness and a pattern discrimination habit, sustained bilateral lesions to the brainstem reticular formation and were subsequently tested for retention. Those groups receiving lesions to the basolateral mesencephalic reticular formation or to the paramedial portion of the reticular formation at either the dimesencephalic juncture, mes-metencephalic juncture, or rostral pontine levels exhibited significant losses in retention of the pattern habit. Lesions destroying either the dorsomedial mesencephalic reticular formation or brainstem areas dorsal, lateral, or ventral to the reticular formation failed to produce significant retention deficits on either habit. Similar findings were obtained in connection with the retention of a nonvisual (kinesthetic) discrimination habit.

Journal ArticleDOI
TL;DR: In this paper, a coaxial line having a small aperture in the sheath and terminating in arbitrary impedances is considered to be illuminated by an incident plane wave, and the excitation of currents in the termination impedances are shown to depend upon three independent factors.
Abstract: A coaxial line having a small aperture in the sheath and terminating in arbitrary impedances is considered to be illuminated by an incident plane wave. The excitation of currents in the termination impedances is shown to depend upon three independent factors. Simple analytical forms are given for equivalent voltage and current sources of the aperture excitation.

Journal ArticleDOI
TL;DR: In Experiments II and III differential responsivity in the expected direction was found, and differences were discussed in connection with the methodology of snake-avoidance therapy analogues.


Journal ArticleDOI
TL;DR: Larvae of Heliothis virescens reared from eggs contaminated with cytoplasmic polyhedrosis virus weighed 50% less and adult emergence was reduced 10% in virus-infected pupae and diseased moths lived 9 days less than healthy moths.

Journal ArticleDOI
TL;DR: Respiration rates of plankton,Physa gyrina (pond snail),Gambusia affinis (mosquitofish), andLepomis macrochirus (sunfish) demonstrate an initial increasing trend, but decrease by as much as 50%, at elevated concentration or extended exposure at low concentration.
Abstract: Exposure of selected aquatic invertebrates to mirex reveals species variability in uptake which is generally a function of exposure period and mirex concentration. The metabolic effects examined relate to photosynthesis and respiration rates. Dissolved oxygen changes, in light and dark bottles containing naturally occurring plankton populations previously exposed to 1 ppb mirex, show progressive photosynthetic inhibition in time from 16% at 6 days exposure to 33% at 18 days exposure. Pure culture of the phytoplankton,Chlamydomonas sp., exhibits a 55% photosynthetic reduction after exposure to 1 ppm mirex for 168 hours. Respiration rates of plankton,Physa gyrina (pond snail),Gambusia affinis (mosquitofish), andLepomis macrochirus (sunfish) demonstrate an initial increasing trend to a maximum of 62%, at low concentration of mirex or during early incubation period, but decrease by as much as 50%, at elevated concentration or extended exposure at low concentration.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the effect of methyl parathion and methyl paraoxon degradation on the tolerance of susceptible and resistant mosquitofish ( Gambusia affinis) to organochlorine compound-resistant and susceptible organisms.


Journal ArticleDOI
TL;DR: Fourteen anodically migrating protein bands were observed in the hemolymph of both Heliothis zea and H. virescens using polyacrylamide gel electrophoresis while the calyx fluid from Cardiochiles nigriceps showed very dilute protein concentrations.
Abstract: 1. 1. Fourteen anodically migrating protein bands were observed in the hemolymph of both Heliothis zea and H. virescens using polyacrylamide gel electrophoresis while the calyx fluid from Cardiochiles nigriceps showed very dilute protein concentrations. 2. 2. In vitro and in vivo melanized blood samples from H. zea and H. virescens contained eleven observable bands. 3. 3. Superparasitized H. zea showed a reduction in hemolymph proteins with eight observable bands. 4. 4. Electrophoresed materials from the parasite, C. nigriceps, revealed eleven protein bands from the teratocytes, nine protein bands from egg homogenates, nine protein bands from second instar larvae homogenates and seven protein bands from the calyx fluid.

Journal ArticleDOI
TL;DR: The SBL chickens offer a model for further studies on humoral immune mechanisms, since the ability of SBL chicks to produce detectable antibody to a primary immunization may be eliminated without further treatment with steroids, cyclophosphamide, or irradiation.
Abstract: SummarySBL birds bursectomized at hatch failed to produce hemagglutinin to a primary injection of SRBC. The antibody titer of LBL birds BSX at hatch did not differ significantly from controls. BSX at 1 week reduced the antibody titer in the SBL birds. BSX at 3 and 5 weeks had no effect on hemagglutinin levels. The number of PFC of SBL BSX at hatch chicks was significantly lower than controls and LBL BSX at hatch birds. There were fewer lymphoid follicles at hatch in the bursae from SBL birds than in the bursae from LBL birds. The SBL chickens offer a model for further studies on humoral immune mechanisms, since the ability of SBL chicks to produce detectable antibody to a primary immunization may be eliminated without further treatment with steroids, cyclophosphamide, or irradiation.

Journal ArticleDOI
TL;DR: In a detailed study of the behavior of Anthonomus grandis Bobeman in frego bract and ‘Deltapine Smoothleaf’ (DPSL) cotton, 2.5 times as many weevils were trappped in or around the DPSL as around the fre go bract cotton.
Abstract: In a detailed study of the behavior of Anthonomus grandis Bobeman in frego bract and ‘Deltapine Smoothleaf’ (DPSL) cotton, 2.5 times as many weevils were trappped in or around the DPSL as around the frego bract cotton. Also, boll weevils moved somewhat more in frego than in DPSL cotton, since about ½ as many introduced weevils were recovered in frego as in DPSL. In DPSL, 64% of the weevils recovered were found in squares, only 20% were recovered in squares on frego cotton. Both overwintered, and current-generation on female weevils deposited about twice as many eggs per hour in the DPSL as in the frego bract cotton.