Showing papers by "Oklahoma State University–Stillwater published in 1971"

Asymptotic Optimality of Fisher's Method of Combining Independent Tests

Abstract: Four methods of combining independent tests of hypothesis are compared via exact Bahadur relative efficiency. The methods considered are Fisher's method, the mean of the normal transforms of the significance levels, the maximum significance level, and the minimum significance level. None of these is uniformly more powerful than the others, but, according to Bahadur efficiency, Fisher's method is the most efficient of the four. In some cases, Fisher's method is most efficient of all tests based on the data, but this is not generally true.

Follicle-Stimulating Hormone and the Regulation of Testosterone Secretion in Rabbit Testes

Abstract: Regulation of testosterone secretion is presumably mediated by interstitial cell-stimulating hormone (ICSH). However, there is little information on the actions of other chemical messengers in regulating testosterone secretion. We have shown that follicle-stimulating hormone augments testosterone secretion stimuated by ICSH in rabbit testes perfused in vitro with an artificial medium.

Steroid Hormones and Aggressive Behavior in Mammals

Abstract: Certain steroid hormones have the ability to alter or modulate the level of excitability in adult brain structures that control the expression of aggression in some mammalian species. Steroids also have been implicated recently in the organization of these same neural tissues during critical periods of development. Conversely, concentrations of circulating hormones in the adult animal may be altered because of an aggressive encounter or because of stimuli inherent in a chronic dominance-subordination social system. The purpose of the present discussion, then, is to overview the literature concerning these relationships. On the behavioral side, we will be interested primarily in “spontaneous” or “inter-male” aggression (Scott, 1966 and Moyer, 1968, respectively) with a nod of recognition to the problems engendered by such categorization as well as by the term aggression itself (cf., Barnett, 1969). Taxonomically, this discussion will, by necessity, rely heavily on studies using house mice with rats and other mammals being considered secondarily.

Odor threshold levels of pyrazine compounds and assessment of their role in the flavor of roasted foods

Abstract: SUMMARY —The concentration of alkylpyrazine compounds in roasted peanuts, coffee and potato chips was determined quantitatively. Ten pyrazines, purified by gas-liquid chromatography, were subjected to sensory evaluation studies in both aqueous and lipid media. Both the odor-detection threshold levels and a subjective evaluation of the odor of the compounds were obtained. This information, coupled with the quantitative knowledge of the pyrazine content of roasted foods, allows an assessment of the probable significance of the pyrazines in the aroma of these food products.

On the solutions of certain linear nonhomogeneous second-order differential equations

Abstract: (1971). On the solutions of certain linear nonhomogeneous second-order differential equations. Applicable Analysis: Vol. 1, No. 1, pp. 57-63.

Kinetic constants for aerobic growth of microbial populations selected with various single compounds and with municipal wastes as substrates.

Abstract: The general applicability of the Monod relationship between the logarithmic growth rate constant and substrate concentration was studied for heterogeneous populations metabolizing a variety of substrates including concentrated municipal sewage. It was found that growth could be described by the Monod equation, μ = μm/ks + s. The kinetic “constants” for heterogeneous populations growing on concentrated sewage were comparable to those found with glucose as substrate.

Effects of Light Deprivation upon the Spermatogenic and Steroidogenic Elements of Hamster Testes

Abstract: The effects of light deprivation (LD) on the spermatogenic and steroidogenic elements of the testis were examined after hamsters were deprived of light for 0, 12, 22 or 42 days. The approach consisted of determining some of the principal biochemical constituents of the testis, examining the metabolism of radioactive glucose, lysine and acetate by the testis in vitro, and measuring circulating levels of testosterone. The results indicate that exposure to constant darkness significantly reduces (p 0.20) despite a 6-fold reduction in testis weight. The incorporation of lysine-U-14C into trichloroacetic acid precipitable material was greater (p<0.01) in atrophied than in control testes, whereas the capacity of testes to catabolize glucose via anaerobic and ae...

Analytical Model for Ice-Structure Interaction

Abstract: In an effort to predict ice-structure interaction, a simple mechanism is proposed. The structure is represented by a spring-mass system and the ice is replaced by a succession of elastic-brittle elements which impinge on the structure at a rate determined by the relative motion between the ice and the structure. A computer program is used to solve for the dynamic response of the structure. A number of test cases and variations have been solved, and the results compared with limited laboratory and field measurements that are available. Interesting agreement has been obtained with observed behavior at various ice velocities. It is believed that the present approach can be used to determine reasonably well the response of a structure to an impinging ice sheet.

Free vibrations of freely supported oval cylinders

Abstract: A study was made of the free vibration frequencies and mode shapes for freely supported oval cylindrical shells. Cross section curvatures were expressed in terms of a single eccentricity parameter that allowed a wide range of doubly symmetric ovals to be studied. Kinematic equations employing both the Love and the Donnell assumptions from thin shell theory were used in this study and results of the two formulations were compared. Little difference was observed between the results obtained from the two theories for a wide range of shell configurations. Comparisons were also made between the results obtained from this study and those from two previous approximate analyses. It was found that one of the approximate analyses (a Rayleigh-Ritz technique) was quite accurate for all ranges of eccentricities studied. The other approximate analysis (a perturbation technique) was found to be reliable for ovals with eccentricities in the range ( — 0.5 < € < 0.5). A study was also made to determine the effects of eccentricity of oval cross sections. The frequencies and mode shapes were found to vary significantly with increasing eccentricities. Irregularities in the frequency vs wave-number curves and a localized "cupping" in the region near the minimum frequency were observed. In-plane inertias were retained yielding the expected three frequencies for each combination of longitudinal and circumferential wave numbers. However, unlike the unstiffened circular cylinder, more than one set of three natural frequencies and associated mode shapes were found for some combinations of longitudinal and circumferential wave numbers. However, although the wave numbers (i.e., number of crossings) were the same in these cases, the wave shapes were obviously different.

Transport of Glycerol by Pseudomonas aeruginosa

Abstract: In Pseudomonas aeruginosa, the transport of glycerol was shown to be genetically controlled and to be dependent on induction by glycerol. Accumulation of 14C-glycerol was almost completely absent in uninduced cells and in a transport-negative mutant. Kinetic studies with induced cells suggested that glycerol may be transported by two systems with different affinities for glycerol. Osmotically shocked cells did not transport glycerol, and the supernatant fluid from shocked cells contained glycerol-binding activity demonstrable by equilibrium dialysis. The binding protein was not glycerol kinase. Binding activity was absent in shock fluids from the transport-negative mutant and from uninduced cells. The glycerol-binding protein was partially purified by precipitation with ammonium sulfate. Mild heat treatment completely eliminated the binding activity of shock fluid and of the partially purified protein. Sodium azide and N-ethylmaleimide inhibited both transport by whole cells and binding of glycerol by shock fluid. It is concluded that transport of glycerol by P. aeruginosa involves a binding protein responsible for recognition of glycerol and may occur by facilitated diffusion or active transport. A requirement for energy has not been demonstrated.

Water balance in the lone star tick (Acariña : Ixodidae) : the effects of relative humidity and temperature on weight changes and total water content.

Abstract: Desiccated, unengorged adult lone star ticks, Amblyomma americanum (L.), increased in weight when exposed to high relative humidities. The observed weight changes were temperature dependent. After exposure for 24 hr at 95% RH, the maximum increase for both males and females occurred at 25°C within the temperature range of 5–45°C used in the experiments. Little weight change took place at 5 and 45°C. Conversely, fully engorged females did not significantly increase in weight under any of the experimental conditions of temperature and humidity. At low humidities, the weight lost by unengorged ticks increased as the temperature was raised. Replete females exhibited a marked ability to resist desiccation at both high temperatures and low humidities. No significant amount of dry weight reserves were converted to metabolic water by unfed adults to replace water lost via transpiration during 24 and 48 hr of desiccation at 0% RH. The significance of these phenomena in the overall salt and water balance and its influence on behavior of the lone star tick is discussed.

The Ecology and Behavior of the Lone Star Tick (Acarina: Ixodidae) I. The relationship between vegetative habitat type and tick abundance and distribution in Cherokee Co., Oklahoma

Abstract: Samples of the lone star tick, Amblyomma americanum (L.), were taken systematically in 10 study areas. With each sample, the type of vegetation was ascertained and data recorded included such parameters as the dominant herbaceous and woody species of plants, density and height of vegetation, amount of leaf litter on the ground, and location of the sample area with relation to the woods and prairie. Lone star tick nymphs were most abundant in areas where the dominant trees were sassafras, persimmon, or winged elm, whereas lowest nymphal and adult populations existed in open prairies. The highest number of adults were encountered in openings in woods and in sassafras-persimmon woods. Where herbaceous or brushy vegetation in woodlots was thin or absent (0–25%), high numbers of nymphs existed, while larger populations of adults were found where there was more than 75% coverage. The highest adult populations were located where less than 25% of the ground was covered with leaf litter, while nymphs were more abundant in areas with greater than 25% coverage. Observations on tick distribution in vegetation of various heights revealed that adults and nymphs were most prevalent in brush and low trees. Tick numbers collected per drag generally decreased with an increase in height of woody vegetation. In grassy associations nymphal and adult numbers were higher in taller vegetation. A study of tick distribution in prairies showed higher populations of nymphs and adults in the immediate vicinity of the ecotone. In general, populations decreased with an increase in distance from the ecotone.

Non-linear oscillations of a third-order differential equation

Abstract: An investigation is conducted into the behavior of the solutions of a third-order non-linear differential equation which is characterized by a non-linearity depending solely upon the Euclidean norm of the associated phase space. The non-linearity represents a central restoring force, which has important applications in modern control theory. For small non-linearities, the existence of a limit cycle is established by a fixed point technique, the approach to the limit cycle is approximated by averaging methods, and the periodic solution is harmonically represented by perturbation. Computer solutions of the differential equation are provided in order to reinforce the analysis. Some related differential equations are discussed including one in which the periodic solution is explicitly prescribed.

The Geography of American Crime, 1968

Abstract: A series of computer-generated maps are presented, illustrating the state-level distribution of major crimes in the United States for the year 1968. The maps are divided into two broad groups—those relating to (a) crimes of violence, and (b) crimes against property. In the violent crime group, distributions are shown for murder, rape, robbery, and assault. The dominance of the South in terms of homicide is particularly striking. Burglary, larceny over fifty dollars, and auto theft are the property crimes represented. Western states, and various highly metropolitan states (such as New York) generally exhibit the highest property crime rates. Summary tables show the states with extreme (high or low) crime rates. States with the lowest rates generally lack large metropolitan nodes, while the converse is true, with California, New York, and Maryland heading the list of states with high rates in multiple crime categories.

Control of growth rate by initial substrate concentration at values below maximum rate.

Abstract: The hyperbolic relationship between specific growth rate, μ, and substrate concentration, proposed by Monod and used since as the basis for the theory of steady-state growth in continuous-flow systems, was tested experimentally in batch cultures. Use of a Flavobacterium sp. exhibiting a high saturation constant for growth in glucose minimal medium allowed direct measurement of growth rate and substrate concentration throughout the growth cycle in medium containing a rate-limiting initial concentration of glucose. Specific growth rates were also measured for a wide range of initial glucose concentrations. A plot of specific growth rate versus initial substrate concentration was found to fit the hyperbolic equation. However, the instantaneous relationship between specific growth rate and substrate concentration during growth, which is stated by the equation, was not observed. Well defined exponential growth phases were developed at initial substrate concentrations below that required for support of the maximum exponential growth rate and a constant doubling time was maintained until 50% of the substrate had been used. It is suggested that the external substrate concentration initially present “sets” the specific growth rate by establishing a steady-state internal concentration of substrate, possibly through control of the number of permeation sites.

Pyrolysis of a slab of porous material

Abstract: This work is an analytical study of the events occurring when a slab of porous material is heated on one side. The problem formulation includes the change in density and thermal conductivity as the material pyrolyzes. This lends to a coupled system of partial differential equations which were solved using the method of integral relations. This method reduces the system to ordinary differential equations which were solved by standard computer routines. Results show that the conductivity has a considerable effect on the temperature under radient heating. Since gas generation is so important to ignition and sustained combustion, it was studied extensively. Curves are given which illustrate the reaction-rate profiles and total gas-generation rate with both endothermic and exothermic reactions. Additional studies emphasize changes in gas generation for a variety of reaction-rate constants, while other curves display the effect of removing the heat source at a specified time. The last section of the paper discusses computations where three reactions were possible. Two reactions competed directly for the original material, while the thrid was consecutive. Typical concentration and temperature histories are given as well as a graph which summarizes data from 28 runs. This graph presents the fraction of solid consumed by the first reaction, plotted against a competition parameter. The competition parameter combines the effects of reaction kinetics and heat conduction into a single number. For moderate heating rate, this concept appears useful but breaks down when higher heating rates are used.

Host Preference, Longevity, Developmental Period and Sex Ratio of Aphelinus asychis with Three Sorghum-Fed Species of Aphids Held at Controlled Temperatures

Abstract: Laboratory studies of Aphelinus asychis (Walker), an imported, internal parasite of aphids, conducted at 5 controlled temperatures showed the preference of the parasite for the aphid species in descending order to be: greenbug, Schizaphis graminum (Rondani); corn leaf aphid, Rhopalosiphum maidis (Fitch), and yellow sugarcane aphid, Sipha flava (Forbes). This trend of preference was consistent at all temperatures, combinations of aphids, and when the parasite was caged individually with each aphid species. The longevity of the adult female decreased with increasing temperature, and the 21.1–32°C alternating temperature yielded an approximate midway response. The mean longevity of adults was approximately 18 days at 23.9°C and 9 days at 32.2°C. The highest ratio of females to males occurred at the coolest temperature studied (23.9°C) with approximately 2.4 ♀ to 1 ♂, while at 32.2°C the ratio was about 1:1. The parasites which emerged from all host aphid species were approximately 60% females when averaged over all temperatures. The parasite took approximately 16 days to develop from egg to adult at 23.9°C and 10 days at 32.2°C. The developmental time for the 21.1–32.2°C fluctuating temperatures was 12.5 days. Unmated female A. asychis produced only male progeny.

Testicular Metabolism in Adrenalectomized and Corticosterone Treated Rats

Abstract: SummaryTesticular metabolism was examined after adult rats were adrenalectom-ized and/or treated with corticosterone (0.7S, 1.5, and 3.0 mg/day) for 5 days. The weight and DNA and RNA concentrations of testes were not affected by either adrenalectomy or corticosterone replacement but corticosterone (3.0 mg) reduced (p<0.05) testis protein and prevented the loss of testis carbohydrate noted after adrenalectomy. Anaerobic glucose catabolism (cell-free preparations) increased 12% (p<0.05) after adrenalectomy and decreased 13% (p<0.05) after corticosterone (3.0 mg) therapy but neither of these treatments affected aerobic glucose catabolism. Corticosterone (3.0 mg) depressed (p<0.05) the oxidation of glucose-1-14C and glucose-6-14C to 14CO2; whereas adrenalectomy showed a tendency to increase the activity of 14CO2. Testosterone synthesis dropped (p<0.05) after corticosterone (3.0 mg) therapy but was not altered by adrenalectomy. The results suggest that adrenalectomy modifies testicular glucose ca-tabolism and...