Showing papers by "Texas A&M University published in 1976"

Experimental Test of Local Hidden-Variable Theories

Abstract: We have measured the linear polarization correlation between the two photons from the $7^{3}S_{1}\ensuremath{\rightarrow}6^{3}P_{1}\ensuremath{\rightarrow}6^{1}S_{0}$ cascade of ${\mathrm{Hg}}^{200}$. The results were used to evaluate Freedman's version of the Bell inequality, $\ensuremath{\delta}l~0$. Our result is ${\ensuremath{\delta}}_{\mathrm{exp}}=+0.046\ifmmode\pm\else\textpm\fi{}0.014$, in clear violation of the inequality and in excellent agreement with the quantum mechanical prediction, ${\ensuremath{\delta}}_{\mathrm{QM}}=+0.044\ifmmode\pm\else\textpm\fi{}0.007$. An important feature of the experiment was the explicit measurement of the initial density matrix for the cascading atoms.

Economic Demand Theory and Psychological Studies of Choice1

Abstract: Publisher Summary This chapter introduces a framework borrowed from economics within which choices between different commodities may be studied in a consistent manner. This framework is “demand theory” and the particular concept within demand theory that most directly applies to studies of choice is that of “substitutability.” The relationship between psychology and economic demand theory is explored. The chapter explores that demand theory is not so much a psychological theory as it is a definition of psychological utility. It specifies an internal mechanism or can be proven true or false. Using economic concepts of budget lines, indifference curves, and substitutability, two series of experiments are conducted involving rats' choices between two different commodities. Consumption of the commodities changed as changes are introduced into the budget set-the rats consumed more of the lower priced commodity and less of the higher priced commodity. Through computer simulation, the maximization of overall rate of reinforcement results in matching of relative rate of responding to relative rate of reinforcement.

Fitting surfaces to scattered data

Abstract: A variety of numerical methods for fitting a function to data given at a set of points scattered throughout a domain in the plane are surveyed. Four classes of methods are discussed: (1) global interpolation; (2) local interpolation; (3) global approximation; and (4) local approximation. Also, two-stage methods and contouring are discussed. The surfaces constructed include polynomials, spline functions, and rational functions, among others.

Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals

Abstract: When exposed to oil-contaminated seawater, marine animals accumulate a wide variety of petroleum hydrocarbons in their tissues. Generally, the aromatic hydrocarbons are accumulated to a greater extent and are retained longer than the alkanes. In all species tested, accumulation of aromatic hydrocarbons appears to be dependent primarily on a partitioning of the hydrocarbons between the exposure water and the tissue lipids. Current evidence indicates that binding of hydrocarbons to tissue lipids is by hydrophobic interactions and not by covalent bonding. Bioaccumulation factors (tissue: water concentration ratio) increase in proportion to the increase in molecular weight of the aromatic hydrocarbons. When returned to oil-free seawater, marine animals rapidly release the accumulated hydrocarbons from their tissues. Release rates are species-dependent. Shrimp and fish, which can metabolize aromatic hydrocarbon, release them more rapidly than clams and oysters, which apparently lack the detoxifying enzymes. Release of hydrocarbons to background or undetectable levels requires from 2 to 60 days. The high molecular weight aromatic hydrocarbons are released more slowly than the low molecular weight hydrocarbons.

Evolution of DNA content in higher plants

Abstract: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Range of Variability of DNA Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 DNA Variation in Higher Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Gymnosperms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Angiosperms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Mechanisms of Change in DNA Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Cellular and Organismic Correlations with DNA Content . . . . . . . . . . . . . . . . . . . . . . . . 40 Functions of DNA Sequences Duplicated or Deleted during Evolution . . . . . . . . . . . . . 41 Prospects for Future Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Multidimensional locus of control in sociopolitical activists of conservative and liberal ideologies.

Abstract: Three studies were conducted to examine the relationship between a multi-dimensional measure of locus of control and sociopolitical activism, controlling for the effects of political ideology. In Study 1, 98 male college students completed a measure of conservatism-liberalism. Kerpelman's Activism scale, and locus of control scales designed to differentiate between two types of externals: belief in powerful others versus belief in chance forces. In Studies 2 and 3, female college students (Ns=26 and 40) who differed in the extent of their participation in leftist political activities or feminist causes responded to the multidimensional locus of control scales. As predicted, results from analyses of variance and trend analyses indicate that for liberals, increases in expectancies of control by powerful others are positively associated with increases in activism, while for conservatives, there is a negative relationship. The importance of controlling for ideology and the implications of the differentiated view of externality for understanding social action are discussed.

Water Stress Induced Alterations of the Stomatal Response to Decreases in Leaf Water Potential

Abstract: Young growth-chamber-grown cotton plants were subjected to a series of eight periods of soil water stress, which served as a preconditioning treatment. After preconditioning, water was withheld and changes in the stomatal resistance and leaf water potential were determined and compared with similar well watered control plants. The stomatal response of stress preconditioned plants adjusted such that the diffusion resistance of the lower surface of the leaf did not reach a value greater than 20 s cm−1 until the leaf water potential dropped 14 bars below that required to reach the same resistance on previously unstressed plants. The resistance—leaf water potential relation for the adaxial surface was unaltered by the preconditioning treatment. Adjustment of the osmotic potential of the guard cells on the abaxial surface provides at least a partial explanation of this change in response. The lack of adjustment of stomatal response on the adaxial surface of the leaves was correlated with a lack of adjustment in osmotic potential of guard cells on that surface.

Multiple deferred state sampling inspection

Abstract: Multiple deferred state sampling is on attribute inspection procedure in which the decision criterion for each lot dictates one of three decisions: (1) accept the lot; (2) reject the lot; or (3) conditionally accept or reject the lot based on the disposition of future related lots. It is intended to supplement existing sampling procedures such as chain sampling, dependent stage sampling, exponential smoothed sampling, and fixed deferred state sampling.

Food division within two sympatric species-pairs of skates (Pisces: Rajidae)

Abstract: Food habits of two sympatric species-pairs of skates (Raja erinacea-R. ocellata and R. radiata-R. senta), which occur off the east coast of North America were investigated. Stomachs from over 1600 specimens of the 4 species were collected during winter, summer, and autumn of 1969 and the winter of 1970. Diets of R. erinacea and R. ocellata consisted largely of amphipods, decapod crustaceans and polychaetes. However, R. ocellata consumed relatively more fishes and polychaetes and less decapods than R. erinacea. These two skates ate many of the same species but in different proportions; R. ocellata tended to feed on infauna and R. erinacea tended to feed on epifauna. Food preferences of the two species may be correlated to the difference in shape of the mouth and number of tooth rows. R. radiata and R. senta both fed heavily on decapod crustaceans and euphausids, but polychaetes were relatively more important to R. radiata and mysids were relatively more important to R. senta. R. radiata had a very diversified diet and fed on both epifauna and infauna. The diet of R. senta was very restricted and consisted almost entirely of epifauna. Diets of the two species-pairs were similar, but isopods and bivalves were more important to the R. erinacea-R. ocellata pair and euphausids and mysids were more important to the R. radiata-R. senta pair. These differences may reflect differences in the benthic communities with which the species-pairs are associated. Amount of overlap in resource utilization of the pairs of skates was compared with that of some other congeneric organisms.

Heavy metals in sediments from San Antonio Bay and the northwest Gulf of Mexico

Abstract: Sediments from San Antonio Bay, the northwest Gulf of Mexico, and the Mississippi River Delta were acid leached and analyzed for Fe, Mn, Pb, Zn, Cd, Cu and Ni by atomic absorption spectrophotometry. In order to account for differences in sediment clay, carbonate, and organic matter content, metal concentrations were normalized to Fe. Significant linear correlations of metals to Fe were obtained for unpolluted sediments and deviations from these “natural” statistical populations were found for areas thought to have metal input caused by man.

Effect of high temperature conditioning on subcellular distribution and levels of lysosomal enzymes

Abstract: The control (C) side of 23 animals was placed in a 2°C chill room at 1 hr postmortem, while the other side was high temperature cdnditioned (HT) at approximately 22°C for 4 hr postmortem, at 12°C for an additional 8 hr and was then placed in the 2°C chill room. The activity of cathepsin C and β-glucuronidase was measured on the nuclear, micro somal, and unsedimentable fractions at 12, 18 and 24 hr postmortem in order to determine the amount of sedimentable and free enzyme activity at these postmortem times. High temperature conditioning enhances the disruption of the lysosomal membrane as evidenced by a significant increase in percent of free enzyme activity at 12 hr postmortem for both cathepsin C and β-glucuronidase. There was also a significant decrease in total activity for both enzymes of the HT group at 12 hr postmortem due to autolysis of the free enzyme. These differences were not present at 18 and 24 hr postmortem (except for decreased total activity of cathepsin C at 18 hr), indicating that differences caused by high temperature conditioning take place very early postmortem and that the differences in enzyme activities are not detectable at later postmortem times. These results indicate that some of the differences in tenderness produced by HT treatments are possibly associated with the increased level of free lysosomal enzymes during the first 12 hr postmortem.

The Origins of Integrated Pest Management Concepts for Agricultural Crops

Abstract: Most discussions of the conceptual origins of integrated pest management (IPM) for crop protection center on the overuse and overdependence of chemical pesticides following World War II and their subsequent unfavorable consequences. Included among examples of these unfavorable consequences are the development of chemical-pesticide-resistant insect and plant pathogen populations, rapid resurgence of target pest populations following treatment, outbreaks of unleashed secondary pests, and undesirable environmental effects. Then as the story goes, this series of mishaps was countered by the wisdom of a few omniscient soothsayers in the form of pest management. Another account described it as a mixture of “idealism, evangelism, pursuit of fashion, fundraising, and even empire-building. The movement has indeed acquired the impetus and character of a religious revival....” (Price Jones, 1970).

On the Identity of the Juvenile Hormone in Insects

Abstract: The secretion of the corpora allata, the juvenile hormone (JH), has a morphogenetic function during the larval life of an insect and may act as a gonadotropin in the adult. On the basis of transplantation experiments, it had been concluded that the hormone of the corpora allata is stage and order unspecific (Wigglesworth, 1970; Novak, 1966). Consequently, the name “juvenile hormone” was retained irrespective of its endocrinological function during a specific postembryonic stage. Piepho (1950) even had suggested that the juvenile hormones of all insects be chemically related, if not identical.

The savanna ecology of Kidepo Valley National Park

Abstract: Summary (1) Food habits of elephant and giraffe were recorded in short sample periods over several years using the feeding minutes technique. (2) Twelve species of common plants were collected on these occasions, separated into their main parts and analysed chemically. (3) Damage to trees was also recorded at intervals. (4) Fifty-nine species of plant were eaten by elephant. During wet months their diet was predominantly grass but during dry months woody vegetation became more important. Giraffe were observed eating from thirty-nine species of plant which were almost entirely browse throughout the year. At least eighteen of these species were also eaten by elephant. (5) Three of the browse species most important to giraffe were also important to elephant in dry seasons. In the driest month the species eaten by giraffe formed more than two-thirds of the observed diet of elephants. (6) Chemical analyses of plants show that browse leaves had a higher level of protein, fat and minerals than most other plants. (7) The trunk of an elephant and the tongue of a giraffe are highly sensitive organs which permit food selection. Elephant in particular appeared to alter their food habits seasonally and it is suggested that this may be an attempt to obtain a balanced intake of nutrients. (8) Due to the effect of elephant and other agencies there is an accelerating decline in Acacia gerrardii woodlands. Browsing and fire are independently preventing their regeneration. (9) The extensive overlap of food requirements on preferred but diminishing browse resources implies potential if not already existing competition between elephant and giraffe. (See Part III.)

Tectonic fabric and hydrothermal activity of Mid-Atlantic Ridge crest (lat 26°N)

Abstract: An asymmetric tectonic fabric was delineated by narrow-beam bathymetric profiles in a 180-km 2 area of the Mid-Atlantic Ridge crest at lat 26°N. Features of the tectonic fabric are a continuous rift valley offset by small ( The rift valley has a double structure consisting of linear segments, bounded by ridges, and basins at the intersections of the minor fracture zones. The double structure of the rift valley acts like a template that programs the reproduction of the tectonic fabric. The minor fracture zones form an asymmetric V about the rift valley at variance with the symmetric small circles formed by major fracture zones. To reconcile the asymmetry of minor fracture zones with the symmetry of major fracture zones, it is proposed that the minor fracture zones have been preferentially reoriented by an external stress field attributed to interplate and intraplate motions. Major fracture zones remain symmetric under the same stress field owing to differential stability between minor and major structures of oceanic lithosphere.

A Risk-Programming Analysis of Forward Contracting with Credit Constraints

Abstract: A multiperiod risk-programming model is developed to evaluate forward contracting and other financial choices for farmers who are subject to market risks and external credit rationing. The model utilizes mean-variance analysis to derive sets of E-V efficient growth plans reflecting the influence of contracting on income stability, levels of credit, and income growth. A case farm is used to develop the model's decision elements and to survey the credit responses of lenders to contract choices. Model results indicate that the lenders' credit responses may modify the producer's contracting plans and his rate of income growth.

Experimental folding of rocks under confining pressure: Part III. Faulted drape folds in multilithologic layered specimens

Abstract: Drape folds and reverse faults are produced experimentally at confining pressures to 20 kb and shortening rates of 10 −3 to 10 −6 sec −1 by displacing a block of brittle sandstone (2 by 3 by 126 cm) along a lubricated saw cut into one to five initially intact layers (02 to 10 cm thick and as much as 126 cm long) of limestone, sandstone, and rock salt The saw cut is inclined at from 30° to 90° to the layer boundary The deformation is characterized from studies of fault geometry, displacements and sequence, bedding-plane slip, layer-thickness changes, and the development of fault gouge, fold hinges, microfractures, calcite twin lamellae, and dimensional orientations of grains (in the rock salt) Stress trajectories are inferred from faults, microfractures, and calcite twin lamellae, and strains are calculated from layer-thickness changes and from calcite twin lamellae Reverse faults curving concave downward propagate upward from the saw cut in the forcing block With increasing displacement along the precut faults, the faults and associated gouge zones in the layer steepen and become progressively younger toward the upthrown block as displacement increases The faults are preceded by swarms of extension microfractures that form throughout the deformation and that are the best clues to the stress trajectories The downthrown layers are thickened by uniform flow and by repetition caused by the faulting They are displaced away from the faults by bedding-plane slip Trajectories of the greatest principal compressive stress (σ 1 ) are inclined at low angles to the layer boundaries near the faults and become perpendicular to these boundaries away from the fault The maximum deformation of the downthrown block occurs when the saw cut is inclined at about 65° to the layering The upthrown layers are all extended parallel to the layering and perpendicular to the fold axes, as indicated by extension fractures, thinned layers, and calcite twin lamellae and the development of graben zones and low-angle normal faults that are conjugate to the reverse faults The layers are translated by bedding-plane slip away from the fault zone Trajectories of σ 1 are inclined from 45° to 90° to the layering The fabric data are internally consistent, and inferred stresses are in good agreement with those calculated from an elastic solution of the experimental boundary conditions Principal strains calculated from calcite twin lamellae are within an average of 001 of those calculated from layer-thickness changes and permit clear resolution of individual events in domains of superposed deformations

Thermodynamic investigation of the lead molecules Pb2, Pb3, and Pb4 by mass spectrometry

Abstract: The high‐temperature Knudsen effusion mass spectrometric technique has been used to determine the thermodynamic properties of the molecules Pb2, Pb3, and Pb4. The enthalpies of the following reactions were determined: nPb(s,l) =Pbn(g), Pb(s,l)+Pbn−1(g) = Pbn(g), and Pbn(g) =nPb(g). From the values obtained and appropriate literature data the following atomization energies D°298 and standard heats of formation ΔH°f,298, in kJ per mole, were obtained: Pb2, 81±6 and 310±6; Pb3, 224±16 and 360±16; and Pb4, 408±16 and 372±16.

Ethanol-induced regional and dose-response differences in multiple-unit activity in rabbits.

Abstract: Multiple-unit activity (MUA), recorded simultaneously from many brain areas, was used to detect the existence and location of ‘target sites’ for ethanol action in rabbits with chronically implanted electrodes in 14 areas. Each of 12 rabbits received intraperitoneal injection of 300, 600, 900, and 1200 mg/kg of 20% ETOH and a saline control injection given in random order with at least a 4-day interval between injections. Large amounts of MUA data, recorded continuously for a 2-min pre-injection control period and a 15-min post-injection period, were quantified by a sensitive and unique technique. MUA changes did not correlate with alcohol-induced changes in the corresponding EEG for the same locus. Whereas visual inspection of the EEG did not disclose any regional differences in response to ethanol, both temporal and topographical differences in ethanol effect on MUA were observed. There were 14 histologically verified brain areas with adequate sample size for statistical evaluation of MUA response. At high doses, all brain areas were affected. Included among the brain areas which were least affected by low doses were the caudate nucleus, septum, fornix, and medial forebrain bundle. Those areas that met the criteria for target sites of responding quickly (<5 min) to low doses (300 mg/kg) were: cerebellar cortex, cerebral cortex, hippocampus, lateral and medial geniculate nuclei, midbrain reticular formation, and pyriform cortex. In conjunction with the preliminary study [Brain Res. 70, 361 (1974)], the data indicate that the most ethanolsensitive tissue is found in the various kinds of cortex, cerebellar and cerebral (both paleocortex and neocortex).