Showing papers by "Texas A&M University published in 1986"

Organizational information requirements, media richness and structural design

Abstract: This paper answers the question, "Why do organizations process information?" Uncertainty and equivocality are defined as two forces that influence information processing in organizations. Organization structure and internal systems determine both the amount and richness of information provided to managers. Models are proposed that show how organizations can be designed to meet the information needs of technology, interdepartmental relations, and the environment. One implication for managers is that a major problem is lack of clarity, not lack of data. The models indicate how organizations can be designed to provide information mechanisms to both reduce uncertainty and resolve equivocality.

Ethical Decision Making in Organizations: A Person-Situation Interactionist Model

Abstract: An interactionist model of ethical decision making in organizations is proposed. The model combines individual variables (moral development, etc.) with situational variables to explain and predict the ethical decision-making behavior of individuals in organizations. A major component of the model is based on Kohlberg's cognitive moral development model which provides the construct definition, measurement tools, and theory base to guide future business ethics research. Research propositions are offered and practical implications are discussed.

Socialization Tactics, Self-Efficacy, and Newcomers' Adjustments to Organizations

Abstract: This study investigated the relationship between the socialization tactics employed by organizations and a series of role and personal outcomes. It also examined the effects of self-efficacy on role orientation. Consistent with predictions, results suggest that different patterns of socialization lead to different forms of newcomer adjustment to organizations. Specifically, institutionalized tactics lead to custodial role orientations, and individualized tactics to innovative role orientations. The results also suggest that self-efficacy moderates this learning process-specifically that socialization tactics produce a stronger custodial role orientation when newcomers possess low levels of self-efficacy.

Oxygen and carbon isotope fractionation in biogenic aragonite: temperature effects

Abstract: To better interpret the isotopic composition of ancient aragonitic fossils, stable-isotopic analyses have been performed on live and modern specimens of aragonitic foraminifera, gastropods and scaphopods. Samples were collected from the continental margins off southern California and Texas, U.S.A., and Mexico, and provide a range in ambient temperature of 2.6–22.0°C. We observed a strong covariance between the δ18O of the aragonitic foraminifera Hoeglundina elegans and that of coeval aragonitic mollusks. On the average, Hoeglundina was 0.2 ± 0.2‰ depleted in 18O relative to the mollusks, and 0.6 ± 0.3‰ enriched relative to the calcitic foraminifera Uvigerina. This enrichment in 18O of aragonite relative to calcite is similar to that observed in previous experimental and theoretical studies. The temperature dependences of mollusk and Hoeglundina δ18O-values were not notably different from that previously determined for inorganically precipitated calcite, and no significant temperature dependence in Hoeglundina-Uvigerina18O fractionation was observed. Of note is the temperature dependence of the δ13C of the biogenic aragonite. Relative to the dissolved inorganic carbon (DIC), the δ13C of Hoeglundina and the mollusks decreased by 0.11 and 0.13‰, respectively, per °C increase in temperature. The temperature dependence in Hoeglundina-DIC 13C enrichment, and the lack of it in Uvigerina-DIC enrichment, accounts for the temperature dependence in Hoeglundina-Uvigerina (calcitic) fractionation noted by us and previous workers. Isotopic differences between coeval specimens of these genera provide a rough measure of paleotemperature without requiring a knowledge of the isotopic composition of the paleo-ocean.

Factors affecting starch digestibility with special emphasis on sorghum and corn

Abstract: Starch exists inside the endosperm of cereals enmeshed in a protein matrix, which is particularly strong in sorghum and corn. Starch digestibility is affected by the plant species, the extent of starch-protein interaction, the physical form of the granule, inhibitors such as tannins, and the type of starch. Among the cereals, sorghum generally has the lowest starch digestibility. The resistance to digestive action of the hard peripheral endosperm layer is largely responsible for this effect. Processing methods such as steam-flaking and reconstitution are effective in raising sorghum digestibility to near that of corn. Waxy sorghum shows consistently higher feeding value than normal sorghum. Both the starch granules and the protein matrix around them are more digestible in waxy grain. The development of new heterowaxy or waxy sorghum hybrids may further increase sorghum feed efficiency.

Implications for mechanical properties of brittle faults from observations of the Punchbowl fault zone, California

Abstract: Field observations of the Punchbowl fault zone, an inactive trace of the San Andreas, are integrated with results from experimental deformation of naturally deformed Punchbowl fault rocks for a qualitative description of the mechanical properties of the fault and additional information for conceptual models of crustal faulting. The Punchbowl fault zone consists of a single, continuous gouge layer bounded by zones of extensively damaged host rock. Fault displacements were not only localized to the gouge layer, but also to discrete shear surfaces within the gouge. Deformation in the exposure studied probably occurred at depths of 2 to 4 km and was dominated by cataclastic mechanisms. Textural data also suggest that significant amounts of pore fluids were present during faulting, and that fluid-assisted mechanisms, such as dissolution, diffusion, and precipitation, were operative. The experimental data on specimens collected from the fault zone suggest that there is a gradual decrease in strength and elastic modulus and an increase in relative ductility and permeability toward the main gouge zone. The gouge layer has fairly uniform mechanical properites, and it has significantly lower strength, elastic modulus, and permeability than both the damaged and the undeformed host rock. For the Punchbowl fault and possibly other brittle faults, the variations in loading of the gouge zone with time are primarily governed by the morphology of the fault and the mechanical properties of the damaged host rock. In addition, the damaged zone acts as the permeable unit of the fault zone and surrounding rock. It appears that the gouge primarily governs whether displacements are localized, and it therefore may have a significant influence on the mode of slip.

The effect of resin formulation on the degree of conversion and mechanical properties of dental restorative resins

Abstract: The goal of this study was to determine the effects of resin formulation variables, such as diluent concentration, catalyst type and concentration and cure mode, on the degree of conversion of carbon double bonds and mechanical properties of dental restorative resins. Diametral tensile strength, compressive strength, hardness, flexural modulus and strength, and dynamic mechanical properties were tested, and the results were correlated to the degree of conversion results obtained by infrared analysis. The results showed a significant correlation between increased mechanical properties and higher degrees of conversion. Enhanced conversions were achieved by incorporating higher diluent and lower inhibitor concentrations into the resins. Ambient temperature properties were similarly enhanced by lower inhibitor concentrations, but were not enhanced by higher diluent concentration. Dynamic mechanical properties testing at oral and elevated temperatures elucidated possible differences in resin microstructure and network quality. The storage moduli decreased over the dental temperature range and was lower at all temperatures for resins with lower conversions. The glass transition temperature was also lower in resins with poorer conversions, suggesting that these resins may be more unstable at oral temperatures than more highly converted resins. Dynamic mechanical properties were most closely correlated to degree of conversion in these polymeric systems.

A methanotrophic marine molluscan (bivalvia, mytilidae) symbiosis: mussels fueled by gas.

Abstract: An undescribed mussel (family Mytilidae), which lives in the vicinity of hydrocarbon seeps in the Gulf of Mexico, consumes methane (the principal component of natural gas) at a high rate. The methane consumption is limited to the gills of these animals and is apparently due to the abundant intracellular bacteria found there. This demonstrates a methane-based symbiosis between an animal and intracellular bacteria. Methane consumption is dependent on the availability of oxygen and is inhibited by acetylene. The consumption of methane by these mussels is associated with a dramatic increase in oxygen consumption and carbon dioxide production. As the methane consumption of the bivalve can exceed its carbon dioxide production, the symbiosis may be able to entirely satisfy its carbon needs from methane uptake. The very light (delta(13)C = -51 to -57 per mil) stable carbon isotope ratios found in this animal support methane (delta(13)C = -45 per mil at this site) as the primary carbon source for both the mussels and their symbionts.

Ordering in ferromagnets with random anisotropy.

Abstract: We summarize and extend our study (using real-space response and correlation functions) of the properties of a continuous-symmetry ferromagnet with random anisotropy, distinguishing between the cases of weak and strong random anisotropy. For the weak-anisotropy case we find three different magnetic regimes, according to the strength of the external magnetic field H. In zero H, the net magnetization is zero, although the ferromagnetic correlation length (FCL) is large. We call a ferromagnet in this first regime a correlated spin glass (CSG). It has a very large magnetic susceptibility, and hence a relatively small coherent anisotropy converts it into a nearly typical ferromagnetic domain structure. Also, a relatively small magnetic field nearly aligns the CSG, producing the second regime, which we call a ferromagnet with wandering axis (FWA). The FWA is a slightly noncollinear structure in which the tipping of the magnetization with respect to the field varies over the system. The tipping angle is correlated over a (field-dependent) correlation length which is smaller than the FCL of the CSG. As the field increases the correlation length in the FWA decreases, until the third regime is reached, wherein the tipping angles (which are smaller than in the FWA) are completely uncorrelated from site to site. We obtain the magnetization or susceptibility (as appropriate) for each of these three regimes. We also show that the temperature dependence of the (single-ion) random anisotropy strength can provide a plausible explanation for certain classes of reentrant phenomena and susceptibility cusps observed in magnetization studies. Neutron scattering studies appear to be consistent with the predicted ${H}^{\mathrm{\ensuremath{-}}1/2}$ dependence of the FCL in the FWA regime, and display the expected rise of the FCL in the CSG regime as the random anisotropy strength decreases with increasing temperature.

A pyramid vector quantizer

Abstract: The geometric properties of a memoryless Laplacian source are presented and used to establish a source coding theorem. Motivated by this geometric structure, a pyramid vector quantizer (PVQ) is developed for arbitrary vector dimension. The PVQ is based on the cubic lattice points that lie on the surface of an L -dimensional pyramid and has simple encoding and decoding algorithms. A product code version of the PVQ is developed and generalized to apply to a variety of sources. Analytical expressions are derived for the PVQ mean square error (mse), and simulation results are presented for PVQ encoding of several memoryless sources. For large rate and dimension, PVQ encoding of memoryless Laplacian, gamma, and Gaussian sources provides rose improvements of 5.64, 8.40 , and 2.39 dB, respectively, over the corresponding optimum scalar quantizer. Although suboptimum in a rate-distortion sense, because the PVQ can encode large-dimensional vectors, it offers significant reduction in rose distortion compared with the optimum Lloyd-Max scalar quantizer, and provides an attractive alternative to currently available vector quantizers.

On the Meaning and Measurement of Religiosity in Consumer Research

Abstract: The role of religiousness as a variable in models of consumer behavior is not well-established. Research findings in this area tend to be sparse and conflicting, and measurement issues have yet to be addressed. This article reports on an empirical investigation of religiosity in a causal modeling framework. The results suggest that religiosity is a viable consumer behavior construct in that it (1) did correlate with the life-style variables selected; (2) contributed directly to the model along with sex, age, and income; and (3) was successfully operationalized through multiple measures.

Kernel Regression Estimation Using Repeated Measurements Data

Abstract: The estimation of growth curves has been studied extensively in parametric situations. Here we consider the nonparametric estimation of an average growth curve. Suppose that there are observations from several experimental units, each following the regression model y(xi)=f(xj)+e(j=1,…,n), where e1, …, e n are correlated zero mean errors and 0≤x1<…

Research Notes: Board Composition and the Commission of Illegal Acts: An Investigation of Fortune 500 Companies

Abstract: In this article the authors discuss research they conducted on corporate boardrooms. They were interested in examining how effective boards of directors that were comprised of outsiders were. They ...

Corporate Political Strategy and Legislative Decision Making: A Review and Contingency Approach

Abstract: This paper attempts to provide a theoretical basis for determining effective corporate political strategies. The strategies considered are the five most commonly used by politically active firms: constituency building, political action committee contributions, advocacy advertising, lobbying, and coalition building. Relevant literature is reviewed and an exchange model of legislative decision making is developed. A contingency approach to the selection of appropriate strategies is derived from the model and a typology of legislative decision situations.

Sex Differences in Interaction Style as a Product of Perceived Sex Differences in Competence.

Abstract: Males' and females' interaction styles were observed while they worked in four-person, mixed-sex groups on a discussion task. In some groups, members were only given information about each others' names and gender. In this circumstance, men were perceived by themselves and other group members to be higher in competence than women. Further, men engaged in a greater amount of active task behavior than women (e.g., giving information, giving opinions), and women exhibited a greater amount of positive social behavior than men (e.g., agreeing, acting friendly). In other groups, members' competency-based status was manipulated by providing false feedback that they were high or low relative to their group in intellectual and moral aptitude. High status members were then perceived to be more competent than low status ones and, further, high status individuals engaged in more active task and less positive social behavior than low status ones. In this condition, no sex differences were obtained on perceived competence or on active task or positive social behavior. Overall, these findings support the idea that the gender differences obtained in interaction when status was not specified were partially a function of group members' belief that the sexes differ in competence. Direct information concerning members' intellectual and moral competence apparently blocked the perceived gender-to-competence link, and status alone affected perceived competence and interaction style.

Large-scale overproduction and rapid purification of the Escherichia coli ssb gene product. Expression of the ssb gene under .lambda. PL control

Abstract: We report a rapid procedure for the large-scale purification of the Escherichia coli encoded single-strand binding (SSB) protein, helix-destabilizing protein which is essential for replication, recombination, and repair processes in E. coli. To facilitate the isolation of large quantities of the ssb gene product, we have subcloned the ssb gene into a temperature-inducible expression vector, pPLc28 [Remaut, E., Stanssens, P., & Fiers, W. (1981) Gene 15, 81-93], carrying the bacteriophage lambda PL promoter. A large overproduction of the ssb gene product results upon shifting the temperature of E. coli strains which carry the plasmid and also produce the thermolabile lambda cI857 repressor. After 5 h of induction, the ssb gene product represents approximately 10% of the total cell protein. The overexpression of the ssb gene and the purification protocol reported here enable one to isolate SSB protein (greater than 99% pure) with final yields of approximately 3 mg of SSB protein/g of cell paste. In fact, very pure (greater than 99%) SSB protein can be obtained after approximately 8 h, starting from frozen cells in the absence of any columns, although inclusion of a single-stranded DNA-cellulose column is generally recommended to ensure that the purified SSB protein possesses DNA binding activity. The ability to easily purify 1 g of SSB protein from 300-350 g of induced cells will facilitate physical studies requiring large quantities of this important protein.

Lesbian mothers and their children: a comparison with solo parent heterosexual mothers and their children.

Abstract: Two types of single-parent households and their effects on children ages 3–11 years were compared. One type comprised 50 homosexual mothers and their 56 children, and the other was a group of 40 heterosexual mothers and their 48 children. There were 30 daughters and 26 sons of homosexual mothers and 28 daughters and 20 sons of heterosexual mothers. The sexual identity and social relationships of the children were assessed in relation to the sexual orientation of the mothers. The samples consisted of families from rural and urban areas in 10 American states. All have lived without adult males (18 years or older) in the household for a minimum of 2 years (average 4). Families with heterosexual mothers were matched to families with homosexual mothers on age and race of mother; length of mother and child separation from father; educational level and income of mother; and number, age, and sex of children. Data are reported from childrens' tests designed to provide information on general intelligence, core-morphologic sexual identity, gender-role preferences, family and peer group relationships, and adjustment to the single-parent family. No significant differences were found between the two types of households for boys and few significant differences for girls. Concerns that being raised by a homosexual mother might produce sexual identity conflict and peer group stigmatization were not supported by the research findings. Data also revealed more similarities than differences in parenting experiences, marital history, and present living situations of the two groups of mothers. The postulated compromised parental fitness of lesbian mothers, commonly asserted in child custody cases, is not supported by these data.

Interspersed Homologous DNA of Autographa californica Nuclear Polyhedrosis Virus Enhances Delayed-Early Gene Expression.

Abstract: The five regions of homologous DNA which are interspersed in the genome of the baculovirus Autographa californica nuclear polyhedrosis virus increased the expression of a delayed-early gene of this virus. Although this activity was first observed as a 10-fold trans effect, the homologous region 5 (hr5) enhanced the expression of linked genes 1,000-fold. The hr5 enhancer also exhibited the other characteristics associated with viral enhancer elements, including orientation independence and the abilities to function at a distance from the linked promoter, to regulate heterologous promoters, and to increase the number of RNA polymerase molecules transcribing the linked genes. The expression of the immediate-early regulatory gene was not enhanced by cis-linked hr5, although the enhancer function may require the immediate-early regulatory gene product. The hr5 enhancer was relatively insensitive to competition by an excess of enhancer molecules. The nucleotide sequence of hr5 revealed two different conserved repeats separated by nonhomologous DNA. Deletion analysis of the hr5 enhancer indicated that a 30-base-pair inverted repeat was essential for enhancer function.

Ion exchange, thermal transformations, and oxidizing properties of birnessite

Abstract: Synthetic sodium bimessite, having a cation-exchange capacity (CEC) of 240 meq/100 g (cmol/kg) was transformed into Li, K, Mg, Ca, Sr, Ni, and Mn2+ cationic forms by ion exchange in an aqueous medium. Competitive adsorption studies of Ni and Ba vs. Mg showed a strong preference for Ni and Ba by bimessite. The product of Mg2+-exchange was buserite, which showed a basal spacing of 9.6 A (22°C, relative humidity (RH) = 54%), which on drying at 105°C under vacuum collapsed to 7 A. Of the cation- saturated bimessites with 7-A basal spacing, only Li-, Na-, Mg-, and Ca-bimessites showed cation exchange. Heating bimessite saturated with cations other than K produced a disordered phase between 200° and 400°C, which transformed to well-crystallized phases at 600°C. K-exchanged bimessite did not transform to a disordered phase; rather a topotactic transformation to cryptomelane was observed. Generally the larger cations, K, Ba, and Sr, gave rise to hollandite-type structures. Mn- and Ni-bimessite transformed to bixbyite-type products, and Mg-bimessite (buserite) transformed to a hausmannite-type product. Li-bimessite transformed to cryptomelane and at higher temperature converted to hausmannite. The hollandite-type products retained the morphology of the parent bimessite. The mineralogy of final products were controlled by the saturating cation. Products obtained by heating natural bimessite were similar to those obtained by heating bimessite saturated with transition elements.

Multiple Criteria ABC Analysis

Abstract: Prioritising items for management attention has been advocated in operations management for a long time, normally using ABC analysis (inventory control). This focuses attention on the “A” category items to maximise managerial effectiveness. Empirical evidence shows that this is a reasonable rule for allocating scarce resource‐management time but presents difficulties when the manager has to take more than one important dimension of a situation into account. A joint criteria matrix is put forward within the ABC framework and an industrial application given. The joint criteria matrix has practical utility provided ranking on some scale of measurement is realistic. The appropriate number of categories must be defined by the user. Combining criteria will probably require different analytical approaches, e.g. goal programming or heuristic approaches. Utilisation of the matrix by managers can provide an explicit method for taking a range of criteria into account in the development of inventory policies.

Ideality of clay membranes in osmotic processes; a review

Abstract: Clays can act as osmotic membranes and thus give rise to osmotically induced hydrostatic pressures. The magnitude of generated osmotic pressures in geologic systems is governed by the theoretical osmotic pressure calculated solely from solution properties and by value of the membrane's three phe- nomenological coefficients: the hydraulic permeability coefficient, Lv; the reflection coefficient, tr; and the solute permeability coefficient, 60. Generally, low values of Lp correspond to highly compacted membranes in which ~ is near unity and r approaches zero. Such membrane systems should give rise to initially high osmotic fluxes and gradual dissipation of their osmotic potentials. The high fluid pressures in the Dunbarton Triassic basin, South Carolina, are a good example of osmotically induced potentials. A unique osmotic cell is created by the juxtaposition of fresh water in the overlying Cretaceous sediments against the saline pore water housed within the membrane-functioning sediments of the Triassic basin. Because wells penetrating the saline core of the basin show anomalously high heads relative to wells penetrating the basin margins, the longevity of this osmotic cell is probably dictated by the rate at which salt diffuses out into the overlying fresh water aquifer.

Synthesis of Todorokite

Abstract: Todorokite of chemical composition (Mg0.77Na0.03)(Mg0.18Mn2+0.60Mn4+5.2222) O12·3.07 H2O was synthesized by a two-step procedure. First, sodium birnessite was synthesized and magnesium was exchanged for sodium to form magnesium birnessite, which was autoclaved under a saturated steam pressure at 155°C for 8 hours to form well-crystallized todorokite. Synthesized todorokite particles consisted of fibers extending from a central plate. The plate itself was made of twinned fibers forming a trilling pattern. The infrared spectra and x-ray diffraction patterns were similar to those of natural todorokite samples. Calcium birnessite and nickel birnessite, when autoclaved under conditions similar to those for magnesium birnessite, yielded a todorokite structure. However, the formation of todorokite from calcium and nickel birnessite was less extensive.

Convolution tails, product tails and domains of attraction

Abstract: A distribution function is said to have an exponential tail F(t) = F(t, ∞) if e αu F(t+u) is asymptotically equivalent to F(t), t→∞, t→∞, for all u. In this case F(lnt) is regularly varying. For two such distributions, F and G, the convolution H=F*G also has an exponential tail. We investigate the relationship between H and its components F and G, providing conditions for lim H/F to exist. In addition, we are able to describe the asymptotic nature of H when the limit is infinite, for many cases. This corresponds to determining both the domain of attraction and the norming constants for the product of independent variables whose distributions have regularly varying tails. In addition, we compare the tails of H=F*G with H 1=F 1*G 1when F is asymptotically equivalent to F and G is equivalent to G 1. Such a comparison corresponds to the “balancing” consideration for the product of independent variables in stable domains of attraction. We discover that there are several distinct comparisons possible.

Transition between frictional slip and ductile flow for halite shear zones at room temperature.

Abstract: A complete transition from frictional slip to ductile shearing flow upon decreasing velocity (or slip rate) or increasing confining pressure is documented for a thin layer of halite undergoing large shearing deformation. The results indicate that the logarithmic law for steady-state friction with a negative velocity dependence breaks down when friction becomes nearly equal to the shear resistance required for ductile flow and that the law changes into a flow law in shear upon further decrease in velocity. The frictionvelocity relation is crucial in stability analyses of fault motion, and the results are important for earthquake and state-of-stress problems, especially in the application of laboratory data to the slow average motion of natural faults and to the behavior of deep faults along which ductile deformation becomes increasingly predominant.