Showing papers by "University of South Carolina published in 1981"

Identification and analysis of moderator variables

Abstract: Although the concept of moderator variables has been used extensively in marketing-related studies, much confusion persists as to how they are defined and identified. To alleviate this confusion, t...

Measurement of Teachers' Beliefs in Their Control over Student Outcome.

Abstract: This paper describes the development of a scale designed to measure teachers’ generalized expectancies for internal-external control over student success and failure in the classroom. The 28-item forced-choice scale is internally consistent and only moderately correlated with Rotter’s I-E Scale. Validation studies indicated that the scale predicted teachers’ behaviors in the classroom, including their willingness to adopt new instructional techniques following inservice training, while the I-E Scale did not. Directions for future research are discussed.

Corporate-Level Strategy, Business-Level Strategy, and Firm Performance

Abstract: Corporate-level strategy and business-level strategy are operationalized in terms of interindustry and intra-industry variation, respectively. Variables representing both levels of strategy are use...

Disturbance and community structure in a shallow water sand flat

Abstract: Diopatra cuprea, an onuphid polychaete, is a large and conspicuous component of semiprotected sand flats along the east coast of North America. It builds a large tube which projects above the surface of the sediment. Infaunal abundances are greater around such tubes than elsewhere. To test the hypothesis that tubes provide a local refuge from predation, I manipulated the abundances of the conspicuous predators and sediment disruptors, Callinectes sapidus the blue crab and Limulus polyphemus the horseshoe crab. In the absence of all predators >0.625 cm, infaunal abundances no longer increased as a function of Diopatra abundance. Thus, the tube of Diopatra appears to act as a refuge from predation for infauna. Further manipulations of the predators indicated that Callinectes was far more important than Limulus. Species which were numerically dominant in the presence of predators predominated in the predator removals as well. These experiments were repeated three times over a 3-yr period (1974, 1975, 1976) and in general the results were consistent over that period. Densities of juvenile Diopatra increased dramatically inside predator exclosures. Densities of adult Diopatra did not. The abundance of this refuge-forming organism, therefore, is at least partially dependent upon the frequency with which individuals pass through the size-dependent period of susceptibility.

Occurrence of low molecular weight and high cysteine containing albumin storage proteins in oilseeds of diverse species

Abstract: The proteins in the oilseeds of species from 11 families, including sunflower, mustard, linseed, almond, lupin, peanut, cucumber, Brazil nut, hazelnut, yucca, castor bean, and cottonseed were studied. Sucrose gradient centrifugation showed that a substantial proportion of the total seed protein from each species migrated with a 2S sedimentation coefficient. The 2S proteins, being water-soluble and thus termed albumins, comprised 20-60% of the total seed proteins, while faster migrating globulins comprised the rest. The amino acid compositions of the 2S proteins were characterisitic of storage proteins by having a high amide content. However, the 2S proteins are different from the classical globulin storage proteins in having a high content of cysteine. It is proposed that 2S albumins are seed storage proteins with a wide distribution and with chemical properties distinct from those of the globulin storage proteins. They play an additional and unique role of providing sulfur reserve for germination. SEED PROTEINS have been traditionally divided into classes based on their solubility in different solvents. In Angiospermae with the exception of Gramineae, the seeds contain primarily globulins and albumins (Osborne,

Can we make sense out of the measurement process in relativistic quantum mechanics

Abstract: We study the instantaneity of the state-reduction process in relativistic quantum mechanics. The conclusion of various authors that this instantaneity will restrict the set of relativistic observables to purely local ones (i.e., that the measurement of any nonlocal property of a system at a well-defined time would give rise to violations of relativistic causality) is found to be erroneous, and experiments (of a kind not encountered before in measurement theory) are described whereby certain nonlocal properties of some simple physical systems can be measured at a well-defined time without violating causality. The attempts of certain authors to reconcile the reduction process with the covariance of the relativistic quantum state are considered and found wanting, and it is argued that the covariance of relativistic quantum theories resides exclusively in the experimental probabilities, and not in the underlying quantum states. The problem of nonlocal measurement is considered in general: distinctions (which are not to be met with in the nonrelativistic case) arise in relativistic quantum mechanics between what can be measured for fermions and what can be measured for bosons, between what can be measured for individual systems and what can be measured for ensembles, and between what kinds of states can be verified by measurement and what kinds of states can be prepared by measurement; and these pose difficult questions about the nature of measurement itself.

A Framework of Participation in Community Organizations

Abstract: This article presents an organizing framework of participation in community organizations which uses an interdisciplinary perspective and attempts to provide a map of the major dimensions that characterize the complex phenomenon of participation. The major elements of the framework include: 1. environmental, ecological, and social characteristics of the community,2. individual differences,3. parameters of participation,4. mediators, and5. the effects of participation. Some potential uses of the framework are suggested.

EXTENDED QMODEL—objective definition of external end members in the analysis of mixtures

Abstract: Analysis of empirical data considered to be mixtures of a finite number of end members has been a topic of increasing interest recently. The algorithms EXTENDED CABFAC and QMODEL by Klovan and Miesch (1976) represent a satisfactory solution to this problem if pure end members are captured within the data set or if the composition of “true” end members are known a priori. Where neither condition is satisfied, the composition of “external” end members can, under certain conditions, be deduced from the structure of the data. Described herein is an algorithm termed EXTENDED QMODEL which defines feasible end members which are “closest” to the data envelope.

Accumulation of proline and glycinebetaine in Spartina alterniflora Loisel. in response to NaCl and nitrogen in the marsh.

Abstract: The possible interaction of high soil salinity and low soil nitrogen content in affecting the growth of Spartina alterniflora Loisel in the high and low marshes of the Eastern U.S. was explored. Throughout the whole growing season, the short plants growing in the high marsh, where there was a higher soil salinity and lower available soil nitrogen, contained more proline and glycinebetaine and showed a lower leaf water potential than the tall plants growing in the low marsh. In both short and tall plants, the growing season, with the highest content occurring in spring and fall. In contrast, the glycinebetaine content in both short and tall plants remained fairly constant throughout the growing season, and was consistently at least 10 fold higher than the proline content. It is estimated that 19–30% of the total leaf nitrogen was in the form of proline and glycinebetaine in the short plants, and 14–27% in the tall plants. Ammonium nitrate fertilization in the field resulted in increased growth, higher proline and glycinebetaine contents, and lower water potentials in the short plants, but had little effect on these parameters in the tall plants. We suggest that in the low marsh, the plants can obtain sufficient nitrogen for osmoregulation and other metabolism. In the high marsh with higher soil salinity and lower nitrogen content, the plants have to allocate a even greater proportion of the already limited nitrogen supply for osmoregulation. Thus, nitrogen available for osmoregulation and other nitrogen-requiring metabolism is insufficient, resulting in reduced growth.

Estimation of material fluxes in an estuarine cross section: A critical analysis of spatial measurement density and errors1

Abstract: Estuarine budget studies often suffer from uncertainties of net flux estimates in view of large temporal and spatial variabilities. Optimum spatial measurement density and material flux errors for a reasonably well mixed estuary were estimated by sampling 10 stations from surface to bottom simultaneously every hour for two tidal cycles in a 320-m-wide cross section in North Inlet, South Carolina. Discharge and ATP and NII,+-N fluxes were computed, The analysis method was to form a number of cases, each based on a different number and combination of stations and compare these fluxes to the ideal case using all 10 stations. A percentage error, y, (rms derivation of a given case from the ideal cast compared to the tidal prism) was <15% with only three lateral stations, each located to cover a separate bathymetric regime. In estuaries with dimensions similar to North Inlet, these results should prove useful in selecting an optimum (or minimum) number of required stations.

Neogene mass extinction of Western Atlantic molluscs

Abstract: There have been many hypotheses for the global mass extinctions that occurred during the Phanerozoic history of the Earth, and although we cannot study the course of such a mass extinction in progress, it is possible to evaluate major pulses of extinction that have taken place recently in geological time. Explanations of the unusually high rates of extinction within late Cenozoic marine faunas of the tropical Western Atlantic have focused on possible blocking of nutrient-laden waters by the origin of the Isthmus of Panama1,2 and on Pleistocene cooling2,3,5,6 or regression2,4,5 of seas. Here we report that major episodes of molluscan extinction occurred at least as far north as Virginia, and we conclude that these episodes were caused primarily by refrigeration associated with the late Pliocene and Pleistocene growth of continental glaciers.

Small-scale spatial distribution ofmeiofauna on a mud- and sandflat

Abstract: Spatial distribution of meiofauna at minimum and maximum populationdensities on a sand- and mudflat in North Inlet, South Carolina, was determined. Using four core sizes ranging in area from 0.3 to 32.0 cm2, plots of Green's Index of Dispersion vs. area sampled usually showed maximum aggregation at 3–5 cm2. Nematodes were slightly patchy at the 5 cm2 scale. The degree of aggregation of harpacticoid copepods was influenced primarily by dispersion patterns of the dominant species. Differences among species spatial distributions were detected. Naupliar and adult distribution was very similar on the mudflat but not on the sandflat. Gastrotrichs were patchy on a smaller scale (3–5 cm2) than had been previously known for this site. The primary patch-generating mechanism was thought to be heterogeneously distributed resources (probably food). Macrofauna and their structures (tubes, etc.), inter-specific competition and social (breeding) behavior were also possible causes. Dispersion patterns of some taxa (e.g. gastrotrichs, mudflat copepods) changed seasonally, presumably due to changes in population density or in the spatial distribution of resources. There were no consistent differences between degree of aggregation on the sandflat vs. the mudflat, two distinctly different meiofaunal habitats.

A distance-based segregation index

Abstract: A tool for measuring segregation in settlement patterns is introduced. This in an extension of the well-known Index of Dissimilarity. By incorporating locations of areal units into the measurement process directly, the distance-based approach substantially reduces the dependence upon size and number of data observations characteristic of the Index of Dissimilarity and other approaches. Experimental tests are reported. These suggest that the locational index constitutes an improvement and is applicable in comparative studies, either cross-sectional or longitudinal.

Campaign contributions and voting on the cargo preference bill: A comparison of simultaneous models*

Abstract: A variety of single equation and simultaneous equation models have been employed to test the hypothesis that interest group campaign contributions influence congressional voting. Although contributions exhibited the anticipated positive effect in all models, the simultaneous equations estimates generally indicated much lower significance levels for the contribution coefficients than did the single equation models. The lower significance levels are apparently attributable to a lack of precision of the simultaneous model estimates (indicated by large standard errors) as well as possible bias of the single equation models. It was also found that qualitative results from the more sophisticated simultaneous probit-Tobit models were quite similar to those obtained from 2SLS estimation of the linear probability model.

Metrizability and the Frechet-Urysohn Property in Topological Groups

Abstract: ABssRAc'r. A question of Arhangel'skii, whether weakly first countable topological groups are metrizable, is answered in two ways: if the Hausdorff axiom is assumed, the answer is yes, but in general a weakly first countable topological group need not be pseudometrizable. The former result is obtained as a corollary of a more general sufficient condition for a sequential group to be Fr&chet-Urysohn. A general necessary and sufficient condition for a sequential group to be FrechetUrysohn is given, and a number of questions are raised. Examples are given to show in what respect the theorems of the paper are the "best possible".

Hyperactive and aggressive behaviors in childhood: intertwined dimensions.

Abstract: The relationship between aggression and hyperactivity is unclear in childhood hyperkinesis. To examine the relationship between the two dimensions, a sample of 109 first-, second-, and third grade children who were rated as hyperactive were evaluated daily by their teachers for 12 consecutive school days on the Daily Behavior Checklist. Daily recordings were made on a total of 22 specific behaviors, 11 physically or verbally aggressive acts, and 11 acts of a restless or hyperactive nature. The Conners hyperactivity score correlated. 47 with daily aggression and .49 with daily hyperactivity. A subgroup of hyperactive children who exhibited both hyperactive and aggressive behaviors at rates greater than 98% of their classmates was selected. These children were rated significantly higher on the Conners scale than an alternate subgroup of hyperactive children who showed high rates of hyperactive but not aggressive behaviors. In view of heavy reliance on teacher ratings with the Conners scale in studies of hyperactivity, careful consideration of the potential confounding of hyperactivity and aggression is recommended. Implications for classification, longitudinal investigation, and evaluation of treatment of hyperactive children were discussed.