Showing papers by "Clemson University published in 1983"

Rules, Discretion and Reputation in a Model of Monetary Policy

Abstract: In a discretionary regime the monetary authority can print more money and create more inflation than people expect. But, although these inflation surprises can have some benefits, they cannot arise systematically in equilibrium when people understand the policymaker's incentives and form their expectations accordingly. Because the policymaker has the power to create inflation shocks ex post, the equilibrium growth rates of money and prices turn out to be higher than otherwise. Therefore, enforced commitments (rules) for monetary behavior can improve matters. Given the repeated interaction between the policymaker and the private agents, it is possible that reputational forces can substitute for formal rules.Here, we develop an example of a reputational equilibrium where the out-comes turn out to be weighted averages of those from discretion and those from the ideal rule. In particular, the rates of inflation and monetary growth look more like those under discretion when the discount rate is high.

Natural Variations in the Analytical Form of the Raindrop Size Distribution

Abstract: Empirical analyses are shown to imply variation in the shape or analytical form of the raindrop size distribution consistent with that observed experimentally and predicted theoretically. These natural variations in distribution shape are demonstrated by deriving relationships between pairs of integral rainfall parameters using a three parameter gamma drop size distribution and comparing the expressions with empirical. There comparisons produce values for the size distribution parameters which display a systematic dependence of one of the parameters on another between different rainfall types as well as from moment to moment within a given rainfall type. The implications of this finding are explored in terms of the use of a three-parameter gamma distribution in dual-measurement techniques to determine rainfall rate.

Emotional Exhaustion in a High Stress Organization

Abstract: This study develops the concept of emotional exhaustion, an extremely affective and chronic type of work-related strain. Sources of emotional exhaustion were investigated in a police organization t...

Loneliness at adolescence: Correlates, attributions, and coping.

Abstract: The present study provides much needed empirical data on the adolescent loneliness experience. One hundred adolescents were given measures of loneliness, loneliness attributions, coping styles, and personal characteristics. Loneliness was positively related to state and trait anxiety, an external locus of control, depression, self-consciousness, and social anxiety and negatively related to self-reported attractiveness, likability, happiness, and life satisfaction. Lonely adolescents were also less willing to take social risks. Adolescents most often attributed loneliness to boredom and most often coped with loneliness by watching TV or listening to music. The implications of these findings for adolescent social development are discussed.

Functionality of muscle constituents in the processing of comminuted meat products

Abstract: Emulsification through the creation of a fat dispersion and formation of an interfacial protein membrane at the fat-water interface is not the sole aspect responsible for comminuted meat "emulsion" stability. In addition, water binding which occurs initially during myofibrillar protein extraction from tissue disruption, and later during entrapment within the heat-induced protein gel matrix, must be included. The criteria that affect formation of the gel matrix adds another aspect, in that conditions for optimum protein-protein interaction also influence ultimate water and fat stabilization. Rheological considerations are in their infancy and will require future study, particularly during the transformation of a "flowing" batter into a "nonflowing" solid product. This review has been aimed at emphasizing that the myofibrillar protein component is the predominant constituent involved in an interactive role with water, fat, and itself, in forming the ultimate stabilized comminuted meat matrix.

Characterization of Methanococcus maripaludis sp. nov., a new methanogen isolated from salt marsh sediment

Abstract: A predominant methanogenic bacterium was isolated from salt-marsh sediment near Pawley's Island, South Carolina. A habitat-simulating medium with H2:CO2 as substrate was used for enrichment and isolation. The methanogen is strictly anaerobic, weakly-motile, non-sporeforming, Gram negative, and a pleomorphic coccoid-rod averaging 1.2 by 1.6 μm. Colonies are circular, translucent, pale yellow, and have a smooth surface and an entire edge. The organism is a mesophile, growing between 18 and 47°C, with an optimum near 38°C. The pH optimum for growth is 6.8–7.2, and only formate or a mixture of H2 plus CO2 serve as substrates. Seawater (20–70% v/v) is required, but it can be replaced by 15 mM, or greater, magnesium. Optimal growth occurs with 110 mM sodium. Growth rate is stimulated by selenium (10 μM) but organic compounds (acetate, vitamins, amino acids) are neither stimulatory nor required. The methanogen grows well in autotrophic medium with a doubling time of about 2h. Cells are fragile, are lysed by aqueous solutions of low osmolality and by detergents, and the lack muramic acid. The cell wall is a single electron dense layer. The DNA base composition is 33 mol % guanine plus cytosine. Antigenic relationship of cells and the 16S ribosomal RNA catalog indicate that the salt marsh methanogen is a unique species of Methanococcus, for which we propose the name Methanococcus maripaludis sp. nov.

Stability of Stream Ecosystems

Abstract: The ability of ecosystems to recover from external disturbances, that is, their stability, is a fundamental property of these systems. Quantification of the ability for various ecosystems to recover and understanding of the mechanisms behind stability are currently areas of major ecological research. In this paper we present an overview of how the stability concept has been used in ecology and a more specific discussion of the application of these ideas to stream ecosystems. This is followed by a case study in which we have been observing the stability of small streams in response to watershed logging and comparing stream stability to stability of the adjacent forest ecosystem.

Increasing atmospheric carbon dioxide: possible effects on arctic tundra

Abstract: Cores of wet coastal tundra collected in frozen condition in winter were used as microcosms in a phytotron experiment that assessed the effects of doubling the present atmospheric CO2 concentration, increasing temperature, and depressed water table on net ecosystem CO2 exchange. Doubling atmospheric CO2 had less significance in regard to net carbon capture or loss in this ecosystem as compared to the significant effects of increased temperature and lowered water table level. Both of the latter are to be expected as atmospheric CO2 increases in the Arctic.

Effects of a CO2-enriched atmosphere on the growth and competitive interaction of a C3 and a C4 grass.

Abstract: Festuca elatior L, C3, and Sorghum halepense (L) Persoon, C4, were grown in mixed and unmixed cultures under 350 and 600 ppm CO2 for 112 days High CO2 levels stimulated increases of total dry weight and leaf surface area in Festuca despite unfavorably high temperatures In Sorghum, delay of leaf senescence and of floral initiation was attributed to high CO2 concentrations Growth of unmixed cultures of Sorghum under 600 ppm CO2 was relatively poor because of an apparent interaction of high CO2 with self-shading All instances of culturexCO2 interactions are offered in supported of the hypothesis that elevated CO2 levels will effect the competitive interaction of C3 and C4 species Peak net assimilation rates of C3 and C4 plants were seasonally separated at 350 ppm CO2 but coincided at 600 ppm Based on our observations of Festuca and Sorghum, we project that global CO2 enrichment may alter competitive balance between C3 and C4 plants and subsequently affect seasonal niche separation, species distribution patterns, and net primary production within mixed communities

Morphology of metazoan circulatory systems

Abstract: The majority of large, bilaterally-symmetric animals possess two structurally distinct systems of internal fluid transport, the coelomic circulatory system and the blood vascular system (BVS). The coelomic circulatory system is generally situated laterally, lined by a continuous layer of mesodermally-derived cells and moves fluid with cilia or body wall muscles. The BVS occurs in extracellular matrix with the principal vessels situated dorsally and ventrally. The vessels are typically unlined by cells. Fluid is propelled by contraction of overlying muscle cells. Co-occurrence of two systems of internal fluid transport is explained by a segmentation hypothesis: Most large, triploblastic animals are segmented with at least two or three fluid-filled compartments separated by septal bulkheads. Because exchange surfaces (gas, nutrient) are regionally restricted, selective pressure favors a fluid transport system that bridges septal bulkheads. The BVS fulfills this requirement because it is situated in extracellular matrix that is non-cellular and continuous throughout organisms. A survey of animals indicates that all segmented taxa possess a BVS, except Sipuncula, where compensation sacs function as BVS analogues. Loss of the BVS in Hirudinea and other annelids is correlated with the disappearance of septa. Funicular vessels in Bryozoa are compared with BVS in other lophophorates. The fluid transport system of Nemertini and some platyhelminths is shown to conform to the definition of a coelomic circulatory system. This investigation supports Liwanow's proposition that the BVS evolved as the progressive modification of extracellular matrix in triploblastic animals. Evolution of coelomic circulatory systems is unresolved.

Characterization of a homogenous preparation of carboxysomes from Thiobacillus neapolitanus

Abstract: A homogenous preparation of carboxysomes was isolated from Thiobacillus neapolitanus by means of density gradient centrifugation and preparative electrophoresis through agarose. Analysis of the carboxysomes by denaturing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of 12–15 polypeptides. Approximately 62% of the total protein was found to consist of the large and small subunits of ribulose-1,5-bisphosphate carboxylase-oxygenase (RubisCO). Two polypeptides were found to be components of the carboxysome shell. Ribose-5-phosphate isomerase, ribulose-5-phosphate kinase, and fructose-1,6-bisphosphatase could not be detected in the carboxysome. Purified carboxysomal and cytoplasmic RubisCO were shown to be similar if not identical by several criteria including specific activity, carboxylase/oxygenase activity, and electrophoretic mobility.

Decomposition in Reliability Analysis of Fault-Tolerant Systems

Abstract: Two important problems which arise in modeling fault-tolerant systems with ultra-high reliability requirements are discussed. 1) Any analytic model of such a system has a large number of states, making the solution computationally intractable. This leads to the need for decomposition techniques. 2) The common assumption of exponential holding times in the states is intolerable while modeling such systems. Approaches to solving this problem are reviewed. A major notion described in the attempt to deal with reliability models with a large number of states is that of behavioral decomposition followed by aggregation. Models of the fault-handling processes are either semi-Markov or simulative in nature, thus removing the usual restrictions of exponential holding times within the coverage model. The aggregate fault-occurrence model is a non-homogeneous Markov chain, thus allowing the times to failure to possess Weibull-like distributions. There are several potential sources of error in this approach to reliability modeling. The decomposition/aggregation process involves the error in estimating the transition parameters. The numerical integration involves discretization and round-off errors. Analysis of these errors and questions of sensitivity of the output (R(t)) to the inputs (failure rates and recovery model parameters) and to the initial system state acquire extreme importance when dealing with ultra-high reliability requirements.

Reciprocity of Trust between Professionals and Their Secretaries

Abstract: This paper proposes and tests a model of interpersonal trust. It is hypothesized that trust between professionals and their secretaries is a reciprocally-reinforcing phenomenon. Participants were 21 attorneys, 31 high-school principals, 28 university department heads, and the secretaries of these professionals. Exogenous variables are locus of control, power expressed, power wanted, perceptions of power expressed and wanted by the other person, and the duration of the superior-subordinate relationship. Explanatory endogenous variables are boss' trust in their secretaries and secretaries' trust in their bosses. These two variables are specified as mutual reinforcers in a nonrecursive structural model, which is tested with a two-stage least squares confirmatory analysis. The reciprocal effects of trust overwhelmed the effects of the exogenous variables on the amount of trust bosses and secretaries had in each other.

Genesis of Tornadoes Associated with Hurricanes

Abstract: The climatological history of hurricane-tornadoes is brought up to date through 1982. Most of the tornadoes either form near the center of the hurricane, from the outer edge of the eyewall outward, or in an area between north and east-southeast of the hurricane center. The blackbody temperatures of the cloud tops which were analyzed for several hurricane-tornadoes that formed in the years 1974, 1975, and 1979, did not furnish strong precursor signals of tornado formation, but followed one of two patterns: either the temperatures were very low, or the tornado formed in areas of strong temperature gradients. Tornadoes with tropical cyclones most frequently occur at 1200-1800 LST, and although most are relatively weak, they can reach the F3 intensity level. Most form in association with the outer rainbands of the hurricane.

Robotic Fabric Handling for Automating Garment Manufacturing

Abstract: This paper presents the potential use of a robotic end-effector for acquiring single plies from a stack of fabrics. This type of end-effector would be required to integrate robots into present-day garment manufacturing operations. Two design concepts, pins and temporary adhesion, were shown experimentally to successfully acquire a single fabric ply from a stack of plies approximately 95 percent of the time. These tests were equally successful on both woven and knit fabrics. Although the experiments were restricted to small square fabric plies, the feasibility of using a robotic end-effector to acquire single plies from a stack of fabrics was demonstrated.

Achievement, power and managerial motivation: selecting managerial talent with the job choice exercise

Abstract: Relying on McClelland's theory of need for Achievement (n Ach) and need for Power (n Pow) this paper hypothesizes that high managerial motivation consists of both high n Ach and high n Pow, and that low managerial motivation consists of both low n Ach and low n Pow. Using the Job Choice Exercise, which is a decision modeling approach to the measurement of n Ach and n Pow, 172 respondents from several different samples were investigated to test these hypotheses. Those who scored high in managerial motivation had higher managerial performance than others, had a higher managerial promotion rate than others, were more likely to be campus leaders than others, or were more likely to be managers than blue collar workers. The opposite was found for low managerial motivation except for managerial performance where there was insufficient data. No difference between the sexes or between the races was found on either the high or the low managerial motivation measure in a nationwide sample of 1,417. Based on these results, the managerial selection implications and early identification of managerial talent implications are discussed.

Encoding of both subunits of ribulose-1,5-bisphosphate carboxylase by organelle genome of Cyanaphora paradoxa

Abstract: The intracellular photosynthetic entities (cyanelles) of the protozoan Cyanophora paradoxa (Fig. 1) have long been regarded as endosymbiotic cyanobacteria due to morphological and physiological similarities such as unstacked thylakoids1, a rudimentary yet lysozyme-sensitive cell wall2,3, and phycobilisomes as light-collecting apparatus4. However, recent investigations of cyanelle DNA cast doubt on this classification. The cyanelle genome has been found to resemble chloroplast DNA in size and structure5–7. In light of the endosymbiont hypothesis of eukaryotic cell evolution8 these paradoxical features of the cyanelles suggest that C. paradoxa is an evolutionary intermediate between cyanobacteria, the presumed plastidal ancestors, and modern photosynthetic organelles. The ribulose-1,5-bisphosphate carboxylase (RuBPCase) of C. paradoxa is composed of eight large (LSU) and eight small (SSU) subunits9. In higher plants and green algae the LSU of the enzyme is encoded by plastid DNA and the SSU is nucleus-encoded10. In cyanobacteria the LSU gene has been located on the chromosome11. No data are available on the SSU gene. Here we have investigated the cyanelles' evolutionary position by determining the location of the genes for the two subunits of RuBPcase in C. paradoxa. By heterologous hybridization the genes for both subunits of RuBPCase have been located on the cyanelle genome. Furthermore, LSU and SSU probes exhibit homology to the same BglII and HindIII fragment, suggesting a close proximity of the two genes.

Post-Secondary Education

Abstract: Since 1970 the number of U.S. college and university students choosing to major in mathematics has declined sharply. There are several sources of data describing this decline and many conjectures about the causes. The situation is summarized in two sections of the paper below.

Prescribed Burning and Water Quality of Ephemeral Streams in the Piedmont of South Carolina

Abstract: Soil and nutrient export were monitored before and after two prescribed burns 18 months apart. Burns were designed to prepare Piedmont pine stands for regeneration. Data from four pairs of treatment and control watersheds were analyzed as a randomized complete block experiment. The burns did not significantly affect storm runoff, sediment concentrations, or sediment export from the watersheds. Both runoff and sediment export increased from one watershed, but the effect was due to a bark beetle outbreak rather than to prescribed burning. Analysis showed no significant change in NO,-N, NHj-N, Ca, Mg, or K concentrations or export after either burn. Sodium concentration before burning was significantly different for the burnedunburned watershed pairs but not significant after either prescribed burn. This difference was attributed to factors other than burning. It was concluded that the two prescribed burns did not change water quality of the streams studied. FOREST Sci. 29:181-189. ADDITIONAL

Computer Simulation of the Mechanical Properties of Nonwoven Fabrics: Part I: The Method

Abstract: We are developing a computer simulation method of predicting the mechanical properties of nonwoven fabrics based on a fundamental microscopic description of the system. The program starts with the known mechanical properties of a given fiber laid out in a web of a particular initial geometry that is held together by some specified means. The evolution of the fabric system as it undergoes a selected distortion is then computed from first principles without recourse to any fabric data. This general method is illustrated with a randomly generated fabric model.