Showing papers by "Oklahoma State University–Stillwater published in 1974"

An Investigation of the Importance of Risk in Farmers' Decisions

Abstract: This paper presents an empirical investigation of the importance of risk in decisions. The adaptive expectations geometric lag model is generalized by geometrically including quadratic lag terms indicative of risk. The computation of consistent estimators is described, and the model is applied in the analysis of California field-crop supply response. Results indicate that the effects of stabilization (possibly associated with government programs) might have seriously offset the acreage-reducing effects of voluntary acreage restrictions. Finally, more general implications relating to reduced-form estimation of the standard Nerlovian model are discussed.

Decision Making: The Role of Education

Abstract: In a dynamic environment with imperfect information, education contributes to production as an "allocative effect," arising from enhanced ability to acquire and process information efficiently, as well as a "worker effect." This study focuses on a single dimension of allocative ability: adjustment of Midwestern U. S. farmers to the changing optimum quantity of nitrogen fertilizer in corn production. Results support the hypothesis that rate of adjustment can be explained by economic variables; the rate is positively related to education of farmers, availability of information (agricultural extension), and scale incentive to be informed (acres of corn). Also, education and extension are substitute sources of allocative efficiency.

Repetition and practice effects in a lexical decision task

Abstract: Ss classified visually presented verbal units into the categories “in your vocabulary” or “not in your vocabulary.” The primary concern of the experiment was to determine if making a prior decision on a given item affects the latency of a subsequent lexical decision for the same item. Words of both high and low frequency showed a systematic reduction in the latency of a lexical decision as a consequence of prior decisions (priming) but did not show any reduction due to nonspecific practice effects. Nonwords showed no priming effect but did show shorter latencies due to nonspecific practice. The results also indicated that many (at least 36) words can be in the primed state simultaneously and that the effect persists for at least 10 min. The general interpretation was that priming produces an alteration in the representation of a word in memory and can facilitate the terminal portion of the memory search process which is assumed to be random.

The cycle of the seminiferous epithelium and spermatogenesis in the bovine testis

Abstract: Morphological changes in the acrosomic system and nuclei of developing spermatids were evaluated as a basis for classifying the stages of the cycle of the seminiferous epithelium in the bovine testis Light microscopic examination of periodic acid-Schiff-stained testicular tissue permitted identification of 14 steps of spermatid development (spermiogenesis) The first 12 steps in this sequence were utilized as the major criterion to divide the cycle of the seminiferous epithelium into 12 distinct stages Following this, the pattern of germ cell differentiation was investigated by counting the number of germ cells at each stage of the cycle Based on cell counts, type A spermatogonia divided primarily during stages VII–VIII and IX–X of the cycle Some type A cells divided again at the end of stage XII to produce intermediate spermatogonia, while others apparently remained “dormant” until the following cycle At the end of stage IV, intermediate spermatogonia divided to produce type B1 spermatogonia which in turn divided at the end of stage V to produce type B2 spermatogonia Primary spermatocytes appeared during stage VIII and divided late in stage XI of the following cycle to form secondary spermatocytes These divided to form young spermatids at the end of stage XII It was concluded that changes in the acrosomic system and nuclear morphology of developing spermatids provide useful criteria for dividing the cycle of the seminiferous epithelium into stages as well as investigating the pattern of germ cell development during spermatogenesis in the bovine testis

Estimation of the Inverse Gaussian Distribution Function

Abstract: Minimum variance unbiased estimates of the inverse Gaussian distribution function for all possible cases are given. A direct relationship is established between its density function and the normal density function, which throws more light on its salient features and possibly on its application in statistical inference. It is shown that the estimates are very similar in nature to those of the normal distribution and can be evaluated from the normal and Student's t distribution tables.

Splines (with optimal knots) are better

Abstract: Let SM k be the Polynominal splines of degree n-1, and with K segments. If f∈ C n [a,b],then the distance in the Lp-norm form(0< p ≦ ∞)of from S M k is boundedby M/K n , with a much smaller M than in similar estimates for other processes of approximation.

Nltrilotriacetic acid as a chelating agent: Applications, toxicology, and bio‐environmental impact

Abstract: The chelating characteristics of nitrilotriacetic acid (NTA) are presented and illustrated with respect to its application in medicine, pharmacy, industry (including detergent formulations), agriculture, and the food industry. The analytical chemistry of NTA is presented with respect to its application as an analytical reagent as well as in the separation and determination of NTA itself. A brief account on the toxicology and bio‐environmental aspects of this chelating agent is also part of this review. Special attention is paid to the controversy generated around NTA and its trisodium salt as a possible substituent for phosphate in heavy‐duty detergent formulations. A table of stability constants for metal complexes of NTA (including mixed‐ligand species) is also presented.

Kinetic properties of rat liver pyruvate kinase at cellular concentrations of enzyme, substrates and modifiers.

Abstract: Kinetic properties of rat liver pyruvate kinase type I at pH75 and 65 were studied with physiological ranges of substrates, modifiers and Mg2+ concentrations at increasing enzyme concentrations, including the estimated cellular concentrations (approx 01mg/ml) Enzyme properties appear unaffected by increased enzyme concentration if phosphoenolpyruvate, fructose 1,6-diphosphate and inhibitors are incubated with enzyme before starting the reaction with ADP Our data suggest that minimum cellular concentrations of MgATP and l-alanine provide virtually complete inhibition of pyruvate kinase I at pH75 The most likely cellular control of existing pyruvate kinase I results from the strong restoration of enzyme activity by the small physiological amounts of fructose 1,6-diphosphate Decreasing the pH to 65 also restores pyruvate kinase activity, but to only about one-third of its activity in the presence of fructose 1,6-diphosphate Neither pyruvate nor 2-phosphoglycerate at cellular concentrations inhibit the enzyme significantly

Electronic conduction and polarization in polyphthalocyanines

Abstract: The polymeric hydrogen form of phthalocyanine is found to be more conductive than the metallic derivatives, in contrast to the behavior of the monomers. In addition, the polymers were found to be much more conductive than the corresponding monomers with the resistivity of the polymers ranging from 7 ohm-cm to about 3 × 106 ohm-cm. The polymers were found to have moderately high dielectric constants ranging from 16 to 1300 at room temperature, depending upon the applied pressure. Based on the dependences of the conductivity and permittivity upon the electric field strength, the average molecular length of the conductive paths within the polymer molecule has been estimated to be 100–1000 A. In view of these estimated lengths, together with the exponential dependence of the permittivity and conductivity upon the pressure and temperature, the dispersion of the dielectric constants in the range of 10–100 KHz, and the chemical architecture of these ribbonlike polymers, the electronic behavior of these polymers is concluded to be consonant with the model of essentially one-dimensional conduction within and along the chains by freed charges. Much as in a number of previously studied highly conjugated polymers, the present polyphthalocyanines are semiconducting and exhibit nomadic polarization, with dielectric constants ranging from 70 to 1300.

Biological dielectrophoresis: the behavior of lone cells in a nonuniform electric field*

Abstract: One of the recently developed physical techniques applicable to problems of biological interest is dielectrophoresis, which is the motion produced by the action of a nonuniform electric field that acts on neutral particles. With this technique, one can analyze and separate various living cells and organelles suspended in an aqueous medium. The technique for handling numerous cells simultaneously has been described e l ~ e w h e r e . ~ ~ O . ~ ~ The theory for the effect in biological circumstances has been derived and found to be consonant with experimentation in several systems.11.12 Experiments by Mason and T ~ w n s l e y ~ ~ proved singularly successful in separating even closely similar cells, namely, yeast cells that differed only by having been grown on two different media. Chloroplasts have been studied by Ting and associates5 The above-mentioned experiments all involved the treatment of rather large numbers of cells a t once. We shall report on the application of the technique to the study of single cells, one a t a time. The method is simple and direct. The force exerted by a nonuniform electric field is induced to act in a direction that opposes that of gravity. At balance, the magnitude of the field provides a measure of the polarizability of the individual cell. In this fashion, cells from a mixed population can be studied separately.

Effect of harvest date and maturity upon free amino acid levels in three varieties of peanuts

Abstract: An improved method for the extraction of free amino acids and a peptide of unknown composition with a methanol:chloroform:water mixture (60:25:15; v:v:v) was described. The largest variations were related to maturity. If the amino acids were ranked in descending order, glutamic acid, followed by asparagine (including asparagine, glutamine, threonine, and serine), topped the list in the mature and low intermediate groups, except in Valencia at 141 days. The peptide and phenylalanine were usually in the top six, while aspartic acid occurred there fairly often. Arginine was the highest in immature peanuts. Proline was found in higher concentrations in immature peanuts than previously reported. The presence of two nonprotein amino acids (γ-methyleneglutamine and γ-methyleneglutamic acid) in mature kernels was confirmed.

Further Analysis of Optimum Size Seaport

Abstract: The problem of berth planning can be solved in the best interests of the port and users in terms of a tradeoff between the cost of berth provision and the value of ships' time spent in port. Other authors have used a more restrictive criterion dealing with idle berth and idle ship time. The Poisson distribution may be used to simulate the number of ships present in the port, but each distribution is specific to the number of berths provided. This last fact requires the use of a numerical iterative procedure. The one used in this paper is the Newton-Raphson method.

Bayesian inferences about a changing sequence of random variables

Abstract: This study is designed to investigate Bayesian procedures for estimating the time point at which a parameter change occurred in an observed sequence of independent random variables of the regular exponential class. In particular, binomial, exponential, and normal sequences are considered and a generalization to the so-called two-phase regression problem is emphasized. In addition, inference to other parameters of the sequence is made.

Experimental studies on a kinetic model for design and operation of activated sludge processes

Abstract: Previous experimentation in our laboratory has shown that the classical theory developed for continuous growth of pure cultures in completely mixed aerobic systems in which the recycle cell concentration factor, c (where c = XR/X), is a selectable system constant, did not provide a suitable model for the heterogeneous (natural) populations of the activated sludge process. Another model was derived in which the recycle cell concentration, XR was employed as a system constant instead of c, and computational analysis was performed. Laboratory pilot plant experimentation was undertaken in order to determine whether a “steady state” in aerator biological solids concentration, X, and substrate concentration, S, could be approached under this mode of operation. Studies were performed at various organic feed concentrations holding dilution rate, D, at 0.125 hr−1, hydraulic recycle ratio, α, at 0.25, and XR at 10,000 mg/liter. Also, values of maximum specific growth rate, μmax, and saturation constant, Ks were determined. It was found that the model approached the steady state condition with heterogeneous populations more closely than did the classical model, and the high degree of treatment efficiency predicted by the model was demonstrated experimentally.

Acute dependence of ovarian progesterone output on the presence of placentas in 21-day pregnant rabbits.

Abstract: The role of the fetuses, placentas and uterus in sustaining the endocrine status of preg-nancy beyond the duration of pseudopregnancy has been examined in the rabbit. Systemic plasma concentrations and ovarian release of progesterone and 20±-hydroxypregn-4-en-3-one remained high when placentas were left in situ 24 hr after fetectomy at day 21 of gestation. However, when the placentas also were extirpated, systemic plasma concentrations and ovarian release of progesterone declined within 24 hr, while systemic plasma concentrations and ovarian release of 20±-hy-droxypregn- 4-en-3-one did not decline. Removal of the entire gravid uterus and hence also pos-sible uterine luteolysin, resulted in decreased systemic plasma concentrations and ovarian release of progesterone 24 hr postoperatively, but not at 6 hr. These observations on systemic plasma concentrations and ovarian release of progestins establish that at day 21 of pregnancy in the rabbit, production of progesterone, by the maternal ovary, is acutely de...