Showing papers by "University of Oklahoma published in 1980"

Analysis and Performance of Fiber Composites

Abstract: Preface. 1 Introduction. 1.1 Definition. 1.2 Characteristics. 1.3 Classification. 1.4 Particulate Composites. 1.5 Fiber-Reinforced Composites. 1.6 Applications of Fiber Composites. Exercise Problems. References. 2 Fibers, Matrices, and Fabrication of Composites. 2.1 Advanced Fibers. 2.1.1 Glass Fibers. 2.1.2 Carbon and Graphite Fibers. 2.1.3 Aramid Fibers. 2.1.4 Boron Fibers. 2.1.5 Other Fibers. 2.2 Matrix Materials. 2.2.1 Polymers. 2.2.2 Metals. 2.3 Fabrication of Composites. 2.3.1 Fabrication of Thermosetting Resin Matrix Composites. 2.3.2 Fabrication of Thermoplastic-Resin Matrix Composites (Short-Fiber Composites). 2.3.3 Fabrication of Metal Matrix Composites. 2.3.4 Fabrication of Ceramic Matrix Composites. Suggested Reading. 3 Behavior of Unidirectional Composites. 3.1 Introduction. 3.1.1 Nomenclature. 3.1.2 Volume and Weight Fractions. 3.2 Longitudinal Behavior of Unidirectional Composites. 3.2.1 Initial Stiffness. 3.2.2 Load Sharing. 3.2.3 Behavior beyond Initial Deformation. 3.2.4 Failure Mechanism and Strength. 3.2.5 Factors Influencing Longitudinal Strength and Stiffness. 3.3 Transverse Stiffness and Strength. 3.3.1 Constant-Stress Model. 3.3.2 Elasticity Methods of Stiffness Prediction. 3.3.3 Halpin-Tsai Equations for Transverse Modulus. 3.3.4 Transverse Strength. 3.4 Prediction of Shear Modulus. 3.5 Prediction of Poisson's Ratio. 3.6 Failure Modes. 3.6.1 Failure under Longitudinal Tensile Loads. 3.6.2 Failure under Longitudinal Compressive Loads. 3.6.3 Failure under Transverse Tensile Loads. 3.6.4 Failure under Transverse Compressive Loads. 3.6.5 Failure under In-Plane Shear Loads. 3.7 Expansion Coefficients and Transport Properties. 3.7.1 Thermal Expansion Coefficients. 3.7.2 Moisture Expansion Coefficients. 3.7.3 Transport Properties. 3.7.4 Mass Diffusion. 3.8 Typical Unidirectional Fiber Composite Properties. Exercise Problems. References. 4 Short-Fiber Composites. 4.1 Introduction. 4.2 Theories of Stress Transfer. 4.2.1 Approximate Analysis of Stress Transfer. 4.2.2 Stress Distributions from Finite-Element Analysis. 4.2.3 Average Fiber Stress. 4.3 Modulus and Strength of Short-Fiber Composites. 4.3.1 Prediction of Modulus. 4.3.2 Prediction of Strength. 4.3.3 Effect of Matrix Ductility. 4.4 Ribbon-Reinforced Composites. Exercise Problems. References. 5 Analysis of an Orthotropic Lamina. 5.1 Introduction. 5.1.1 Orthotropic Materials. 5.2 Stress-Strain Relations and Engineering Constants. 5.2.1 Stress-Strain Relations for Specially Orthotropic Lamina. 5.2.2 Stress-Strain Relations for Generally Orthotropic Lamina. 5.2.3 Transformation of Engineering Constants. 5.3 Hooke's Law and Stiffness and Compliance Matrices. 5.3.1 General Anisotropic Material. 5.3.2 Specially Orthotropic Material. 5.3.3 Transversely Isotropic Material. 5.3.4 Isotropic Material. 5.3.5 Specially Orthotropic Material under Plane Stress. 5.3.6 Compliance Tensor and Compliance Matrix. 5.3.7 Relations between Engineering Constants and Elements of Stiffness and Compliance Matrices. 5.3.8 Restrictions on Elastic Constants. 5.3.9 Transformation of Stiffness and Compliance Matrices. 5.3.10 Invariant Forms of Stiffness and Compliance Matrices. 5.4 Strengths of an Orthotropic Lamina. 5.4.1 Maximum-Stress Theory. 5.4.2 Maximum-Strain Theory. 5.4.3 Maximum-Work Theory. 5.4.4 Importance of Sign of Shear Stress on Strength of Composites. Exercise Problems. References. 6 Analysis of Laminated Composites. 6.1 Introduction. 6.2 Laminate Strains. 6.3 Variation of Stresses in a Laminate. 6.4 Resultant Forces and Moments: Synthesis of Stiffness Matrix. 6.5 Laminate Description System. 6.6 Construction and Properties of Special Laminates. 6.6.1 Symmetric Laminates. 6.6.2 Unidirectional, Cross-Ply, and Angle-Ply Laminates. 6.6.3 Quasi-isotropic Laminates. 6.7 Determination of Laminae Stresses and Strains. 6.8 Analysis of Laminates after Initial Failure. 6.9 Hygrothermal Stresses in Laminates. 6.9.1 Concepts of Thermal Stresses. 6.9.2 Hygrothermal Stress Calculations. 6.10 Laminate Analysis Through Computers. Exercise Problems. References. 7 Analysis of Laminated Plates and Beams. 7.1 Introduction. 7.2 Governing Equations for Plates. 7.2.1 Equilibrium Equations. 7.2.2 Equilibrium Equations in Terms of Displacements. 7.3 Application of Plate Theory. 7.3.1 Bending. 7.3.2 Buckling. 7.3.3 Free Vibrations. 7.4 Deformations Due to Transverse Shear. 7.4.1 First-Order Shear Deformation Theory. 7.4.2 Higher-Order Shear Deformation Theory. 7.5 Analysis of Laminated Beams. 7.5.1 Governing Equations for Laminated Beams. 7.5.2 Application of Beam Theory. Exercise Problems. References. 8 Advanced Topics in Fiber Composites. 8.1 Interlaminar Stresses and Free-Edge Effects. 8.1.1 Concepts of Interlaminar Stresses. 8.1.2 Determination of Interlaminar Stresses. 8.1.3 Effect of Stacking Sequence on Interlaminar Stresses. 8.1.4 Approximate Solutions for Interlaminar Stresses. 8.1.5 Summary. 8.2 Fracture Mechanics of Fiber Composites. 8.2.1 Introduction. 8.2.2 Fracture Mechanics Concepts and Measures of Fracture Toughness. 8.2.3 Fracture Toughness of Composite Laminates. 8.2.4 Whitney-Nuismer Failure Criteria for Notched Composites. 8.3 Joints for Composite Structures. 8.3.1 Adhesively Bonded Joints. 8.3.2 Mechanically Fastened Joints. 8.3.3 Bonded-Fastened Joints. Exercise Problems. References. 9 Performance of Fiber Composites: Fatigue, Impact, and Environmental Effects. 9.1 Fatigue. 9.1.1 Introduction. 9.1.2 Fatigue Damage. 9.1.3 Factors Influencing Fatigue Behavior of Composites. 9.1.4 Empirical Relations for Fatigue Damage and Fatigue Life. 9.1.5 Fatigue of High-Modulus Fiber-Reinforced Composites. 9.1.6 Fatigue of Short-Fiber Composites. 9.2 Impact. 9.2.1 Introduction and Fracture Process. 9.2.2 Energy-Absorbing Mechanisms and Failure Models. 9.2.3 Effect of Materials and Testing Variables on Impact Properties. 9.2.4 Hybrid Composites and Their Impact Strength. 9.2.5 Damage Due to Low-Velocity Impact. 9.3 Environmental-Interaction Effects. 9.3.1 Fiber Strength. 9.3.2 Matrix Effects. Exercise Problems. References. 10 Experimental Characterization of Composites. 10.1 Introduction. 10.2 Measurement of Physical Properties. 10.2.1 Density. 10.2.2 Constituent Weight and Volume Fractions. 10.2.3 Void Volume Fraction. 10.2.4 Thermal Expansion Coefficients. 10.2.5 Moisture Absorption and Diffusivity. 10.2.6 Moisture Expansion Coefficients. 10.3 Measurement of Mechanical Properties. 10.3.1 Properties in Tension. 10.3.2 Properties in Compression. 10.3.3 In-Place Shear Properties. 10.3.4 Flexural Properties. 10.3.5 Measures of In-Plane Fracture Toughness. 10.3.6 Interlaminar Shear Strength and Fracture Toughness. 10.3.7 Impact Properties. 10.4 Damage Identification Using Nondestructive Evaluation Techniques. 10.4.1 Ultrasonics. 10.4.2 Acoustic Emission. 10.4.3 x-Radiography. 10.4.4 Thermography. 10.4.5 Laser Shearography. 10.5 General Remarks on Characterization. Exercise Problems. References. 11 Emerging Composite Materials. 11.1 Nanocomposites. 11.2 Carbon-Carbon Composites. 11.3 Biocomposites. 11.3.1 Biofibers. 11.3.2 Wood-Plastic Composites (WPCs). 11.3.3 Biopolymers. 11.4 Composites in "Smart" Structures. Suggested Reading. Appendix 1: Matrices and Tensors. Appendix 2: Equations of Theory of Elasticity. Appendix 3: Laminate Orientation Code. Appendix 4: Properties of Fiber Composites. Appendix 5: Computer Programs for Laminate Analysis. Index.

The Deterrent Effect of Perceived Severity of Punishment

Abstract: Previous findings from perceptual studies of deterrence lead to the conclusion that perceived certainty of punishment (but not perceived severity of punishment) is inversely related to involvement in illegal behavior. The conclusion concerning severity is inconsistent with the rational image of man in utilitarian thought, the philosophicalframework in which modern deterrence theory is grounded. We question the validity of previous measures of perceived severity and argue that the appropriate hypothesis never has been tested with a valid measure. In our own analysis we use a refined measure which we believe is more consistent with the utilitarian perspective. The results support the hypothesis that perceived severity, at relatively high levels of perceived certainty, has a significant deterrent effect. Deterrence theory, like exchange theory and utility theory, is rooted in philosophical utilitarianism in viewing man as a "profit maximizer, that is, a calculator of profit from estimates of gain and cost resulting from the projected act" (Geerken and Gove, 497). Deterrence research focuses on one type of potential cost, the threat of legally imposed physical and/or material deprivation; and on one type of projected act, law violation. Recently, sociological research on deterrence has shifted from a concern with relationships among aggregate properties (e.g., arrest rate and crime rate) to a concern with the relationship-between individuals' perceptions of legal sanctions and their involvement in illegal behavior.1 The relevant dimensions of an individual's perceptions are the perceived certainty of arrest and the perceived severity of punishment if arrested. These reflect the subjective probability of incurring a particular cost and the magnitude of that cost if it is incurred. The rational actor of the utilitarians, when deciding whether to commit an illegal act, estimates the probability of receiving a legally imposed penalty (perceived certainty of arrest) and the magnitude of that penalty (perceived severity of punishment if arrested). This potential cost is added to other potential costs which are compared to potential

The role of thermals in the convective boundary layer

Abstract: Detailed measurements of the structure of thermals throughout the convective boundary layer were obtained from the NCAR Electra aircraft over the ocean during the Air Mass Transformation Experiment (AMTEX). Humidity was used as an indicator of thermals. The variables were first high-pass filtered with a 5 km cutoff digital filter to eliminate mesoscale variations. Segments of the 5 min (30 km length) horizontal flight legs with humidity greater than half the standard deviation of humidity fluctuations for that leg were defined as thermals. This was found to be a better indicator of thermals than temperature in the upper part of the boundary layer since the temperature in a thermal is cooler than its environment in the upper part of the boundary layer. Using mixed-layer scaling, the normalized length and number of thermals were found to scale with the 1/3 and -1/3 powers, respectively, of normalized height, while vertical velocity and temperature scaled according to similarity predictions in the free convection region of the surface layer. The observational results presented here extend throughout the entire mixed layer. Using these results in the equation for mean updraft velocity of a field of thermals, the sum of the vertical pressure gradient and edge-effect terms can be estimated. This residual term is found to be important throughout most of the boundary layer. The magnitude of the divergence of vertical velocity variance within a thermal is found to be larger than the magnitude of the mean updraft velocity term throughout most of the mixed layer.

A penalty plate‐bending element for the analysis of laminated anisotropic composite plates

Abstract: : A C degrees (penalty) finite element is developed for the equations governing the heterogeneous laminated plate theory of Yang, Norris and Stavsky. The YNS theory is a generalization of Mindlin's theory for homogeneous, isotropic plates to arbitrarily laminated anisotropic plates and includes shear deformation and rotary inertia effects. The present element can also be used in the analysis of thin plates by appropriately specifying the penalty parameter. A variety of problems are solved, including those for which solutions are not available in the literature, to show the material effects and the parametric effects of plate aspect ratio, length-to-thickness ratio, lamination scheme, number of layers and lamination angle on the deflections, stresses, and vibration frequencies. Despite its simplicity, the present element gives very accurate results. (Author)

Urban Policy: Does Political Structure Matter?

Abstract: An interrupted time-series quasi-experiment is employed to test the basic hypothesis that reformed cities (with city manager, at-large elections, and nonpartisan ballots) tax and spend less than unreformed communities. Eleven cities with populations of 25,000 and above which significantly changed their political structure between 1948 and 1973 are compared with 11 matched control cities that made no changes. We found that over an 11-year period, variations in fiscal behavior were virtually unaffected by changes in city government structure.

Evaluation of injuries in youth soccer.

Abstract: Soccer has rapidly gained in interest in the United States. A paucity of available data on soccer injuries led us to formulate this study to quantitate and categorize injuries acquired during a program of youth soccer (under age 19). A prospective study of 1,272 players showed an injury rate of 2.6 injuries per 100 participants. The injury rate for girls was twice as great as for boys. The under 10-age group was seldom injured (less than 1 injury per 100 participants), but the overall injury rate in the players of secondary school age was 7.7 injuries per 100 participants. Most injuries were not serious. Soccer appears to be a safe activitiy for adolescents and children.

Corporate Organization of R and D and the Location of Technological Activities

Abstract: Malecki E. J. (1980) Corporate organization of R and D and the location of technological activities, Reg. Studies 14, 219–234. This paper examines in detail the role of R and D and technological innovation in corporate strategy and structure, focusing on the manner in which R and D is treated in corporate spatial organizations. Organizational and locational aspects of large, multilocational firms are a manifestation of strategies and priorities concerning product mix, technology and production. Of particular importance is the choice between centralized and decentralized R and D, both organizationally and locationally. The locations chosen by firms for technological activities have a major impact on the economic development of regional economies, through agglomeration and the creation and maintenance of a regional technology base. Three location types for R and D, headquarters, production sites and innovation centers, are verified empirically from the R and D sites of U.S. corporations.

Effects of castration on the bone structure of male rats: A model of osteoporosis

Abstract: Forty young (23-day-old) and thirty old (1-year-old) male rats were castrated and sacrificed with controls at intervals up to 18 months of age. No differences were observed between femurs or mandibles of rats castrated at 23 days and those of controls. Year-old castrate rats developed femoral osteoporosis after 2 months, which became more pronounced 4 months after castration. This was characterized by reductions in femoral density, dry weight, dry weight per unit length, and ash weight, and by the appearance of resorption cavities in diaphyseal walls and a sparsity of trabeculae in metaphyses and epiphyses of castrate femurs. These results indicate that the year-old castrate male rat may be a valuable experimental model for studies of the treatment of osteoporosis.

Waverider Configurations Derived from Inclined Circular and Elliptic Cones

Abstract: Lifting-body wavender configurations, with curved surfaces and known pressure fields and shock-layer structures, are constructed from stream surfaces generated by means of supersonic flows past inclined circular and elliptic cones. The conical flowfields are perturbations of the basic axisymmetric cone flow arising from small angle of attack and small cross-sectional eccentricity. The approximate results are analytic and in the form of hypersonic small-disturbance theory. Formulas are presented that determine how the Mach number, angle of attack, cross-sectional eccentricity, and characteristic cone angle affect the waverider shape, pressure distribution, and shock-layer structure.

A Comparison of Components of Written Expression Abilities in Learning Disabled and Non-Learning Disabled Students at Three Grade Levels.

Abstract: Although written language plays a critical role in academic success, little empirical evidence exists on the normal development of processes involved in producing written products. Even less is known about the writing performance of LD children. This study empirically compared the written products of LD and normal students at three grade levels on The Test of Written Language. Results showed that LD subjects scored significantly lower than normal subjects on most written expression abilities, especially in the mechanical tasks of spelling, punctuation, and word usage.

A Framework for the Use of Power

Abstract: Focuses on ways in which channel co‐operation and co‐ordination can be improved and unnecessary dysfunctional conflict reduced. Maintains that the purpose herein is to provide a better understanding of power relationships in marketing channels so that the likelihood of positive outcomes is increased, as this insight is important for both the systems and independent perspectives. Purports that power is the vehicle by which the range of variability in channel behaviour is limited, and a measure of predictability and dependability is established. Sums up that power has been acknowledged as a means by which the conduct of the channel members can be co‐ordinated so as to achieve a higher level of channel efficiency. Proposes that a framework has been presented which serves as a guide to the marketer in outlining the responses, which may ensue from the exercise of power.

Thermography as an indicator of blood perfusion.

Abstract: Skin temperatures recorded by the scanning infrared camera are the resultant balance of the thermal transport within the tissues and the transport to the environment. In medical thermography, the thermal image is obtained in a controlled environment usually with temperature at approximately 2OOC. The rate of thermal energy flow from the skin to the environment is consequently the result of the convection and radiation modes. The evaporation rate is normally low under equilibrium conditions in such an environment and thus is only a secondor higher-order effect. It is very important that the clinic environment be carefully controlled. This control includes an assurance that the clinic is isothermal (k0.2OC) and that the airflow over the patient is uniform and steady. With control of the environment, the skin temperature may then be utilized to estimate the physiological activity influencing the surface temperature. On convex surfaces of the body that do not receive thermal radiation from other parts of the skin, the thermal image demonstrates a range of temperatures. On the abdomen, thorax and back, the normal range observed will be from about 25OC to a maximum of 36OC. The higher temperature represents the skin superficial to veins that are involved in active transport of blood. It is well known that collateral venous networks provide for blood returning to the vena cava to flow in either the deep veins, the superficial system, or both. The superficial veins course just below the skin and superficial to the subcutaneous fat layer. The blood in the active veins will represent an average temperature of the tissues drained. Thus the skin temperatures associated with these venous patterns provide important information for the assessment of the physiological state. Factors affecting skin at a distance from these veins are blood perfusion, tissue thermal conductivity, and metabolic heat generation. It is important to the understanding of the meaning of skin temperature patterns that the relative role of each of these variables be known. It is unfortunate that much of the medical literature has totally misinterpreted the skin temperatures as being the direct result of a high temperature source (a tumor) buried within the tissue. The following analysis demonstrates conclusively that the blood perfusion associated with metabolic activity dominates the effect of metabolic heat generation. Draper and Boag'** indicate that the increase in temperature of the skin noted with breast cancer is due primarily to increased blood flow. However, they proceeded to utilize a pure conduction model neglecting the effects of blood perfusion in computation of the skin temperature patterns. They discount the work of Law~on.~ In fact, the measurement of temperature of blood flowing in arteries and veins during surgery is extremely difficult. The temperatures of arterial blood reported by Lawson

Leg 67: The Deep Sea Drilling Project Mid-America Trench transect off Guatemala

Abstract: Drill cores from a transect of the Mid-America Trench off Guatemala were obtained at three sites on the oceanic Cocos plate, and at four sites on the continental Caribbean plate. An ocean sub-bottom seismometer was successfully emplaced in the deepest hole in the trench landward slope where it was left to record data after departure of the drill ship. Drilling on the Cocos plate recovered a basal chalk sequence deposited during early and mid-Miocene time, a short interval of abyssal red clay, and an upper sequence of late Miocene and younger sediment deposited within an area influenced by a terrigenous source. In the trench, a mud and sand fill less than 400,000 yr old overlies the oceanic sequence. The entire section shows no evidence of compressive deformation even at holes drilled against the trench9s landward slope. In contrast, the section cored on the trench9s landward slope 3 km from the trench axis is affected by tectonism. The section contains a Cretaceous to Pliocene claystone sequence, broken by hiatuses but in a normal stratigraphic succession that is capped by Pliocene to Quaternary hemipelagic slope deposits. Seismic records show that the section overlies probable igneous oceanic crust from which it is separated by a few hundred metres. That thickness of undrilled section is insufficient to accommodate the potential offscraped volume of oceanic sediment carried into the trench during Neogene plate convergence. At the estimated 10 cm/yr rate of convergence, much of the oceanic sediment must have been subducted rather than tectonically accreted to the Guatemalan margin. Current models for convergent margin tectonics do not satisfactorily explain the surprising occurrence of Cretaceous to Miocene mudstone at the base of this trench slope. The recovery of gas hydrates prevented drilling to some landward-dipping reflections presumed to be imbricate thrust slices at two sites near the middle of the trench landward slope.

Pulmonary alveolar proteinosis: the diagnosis by segmental lavage.

Abstract: Histologic findings from segmental lavage material via the fiberoptic bronchoscope were evaluated as a means of diagnosing pulmonary alveolar proteinosis. Active cases of alveolar proteinosis yielded grossly opaque and/or milky effluents. The unique histologic findings in alveolar proteinosis included: (1) very few alveolar macrophages (2) large acellular eosinophilic bodies in a diffuse background of eosinophilic granules, and (3) periodic acid-Schiff staining of the proteinaceous material with a lack of significant alcian blue staining. Thus, the diagnosis of pulmonary alveolar proteinosis can be made by evaluation of the clinical setting and histologic findings of the effluent material from a segmental lavage.

Patterns of morphological and molecular polymorphism in the land snail Cepaea nemoralis

Abstract: In the land snail Cepaea nemoralis, allele frequencies at loci controlling shell polymorphisms often show large areas of remarkable constancy which are separated by steep clines from neighbouring areas with strikingly different allele frequencies. It has recently been claimed that these ‘area effects’ exemplify a general tendency for population differentiation without geographic isolation in a variety of organisms of relatively low mobility. As such they could represent an early phase in the process of speciation. If this is true, population differentiation of shell polymorphisms in Cepaea would be expected to be accompanied by parallel differentiation at other gene loci, such as those detected by gel electrophoresis. We have studied populations of C. nemoralis in North Wales and in the Valle de Aran of the Pyrenees. Levels of molecular heterogeneity are comparable to those found in related animals which show much less visible polymorphism. In spite of some statistical problems inherent in the analysis ol overlapping geographic patterns, there is no clear association between the patterns of geographic variation at the visible and molecular levels. Claims that genetic differentiation in the visible polymorphisms between C. nemoralis populations are a special case of the formation of geographic races are therefore probably not justified.

The control ofEigenmannia's pacemaker by distributed evaluation of electroreceptive afferences

Abstract: This study analyzes the algorithm by which a distributed system of neurons evaluates specific features in sensory feedback and thereby controls a behavioral response.

Ammonium influence on nitrogen assimilating enzymes and protein accumulation in suspension cultures of Paul's Scarlet rose

Abstract: The influence of NH4+ on protein accumulation was examined by growing suspension cultures of Rosa cv. Paul's Scarlet on two defined media. Both contained 1920 μmol of NO3− but only one contained 72.8 μmol of NH4+. At the conclusion of a 14-day growth period, cultures grown with NH4+ possessed twice as much protein as cultures grown without NH4+. The influence of NH4+ did not appear to be a substrate effect, since the amount of NH4+ provided accounted for only 10% of the nitrogen recovered in protein. The provision of NH4+ in the starting medium increased the activity (μmol substrate. h−1· g−1 fr wt) of glutamate dehydrogenase and glutamate synthase, and reduced the activity of glutamine synthetase. A comparison of the total activity per culture for each of these enzymes with the rate of nitrogen incorporation into protein showed that the enzymatic potential of glutamine synthetase and glutamate dehydrogenase greatly exceeded the actual in vivo rate of nitrogen assimilation through the respective pathways. Thus it was concluded that the availability of either of these enzymes does not limit nitrogen assimilation in rose cells and the fluctuations in their level brought about by NH4+ was of no physiological importance. The activity of glutamate synthase per culture approximated the rate of nitrogen incorporation into protein during early stages of growth, and for that reason may have limited nitrogen assimilation or caused a diversion of nitrogen through the alternative pathway to glutamate catalyzed by glutamate dehydrogenase.

Deterrence and the Morally Committed

Abstract: The deterrence literature suggests that perceptions of the threat of legal sanctions influence the extent of involvement in illegal behavior only among those individuals who have not internalized legal norms. Individuals who are morally committed to a norm will not violate it, regardless of their perceptions of the certainty and severity of legal sanctions. We argue that this hypothesis relegates coercion to a position of secondary importance in a theory of social control; and we offer a rationale for an alternative hypothesis that perceived sanction threat has a deterrent effect at all levels of moral commitment. Our analysis, using refined measures of the variables which have emerged in recent research, supports our alternative hypothesis.

Neural correlates of the jamming avoidance response ofEigenmannia

Abstract: 1. Single unit responses of electroreceptors, of Posterior Lateral Line Lobe cells and of Torus Semicircularis cells were studied. Three types of stimuli were used; one was sufficient for evoking the jamming avoidance response and the other two lacked key features necessary for the behavior's occurrence. Responses to each of these stimuli were compared to determine which stimulus parameters were measured by each cell type. 2. The receptor population was divided into two groups. The P-receptors, probability coders, responded primarily to changes in the amplitude of the stimulus. No differences were seen in the phases of their peak activity during stimulation with either +ΔF or −ΔF beats or with amplitude modulations of a pure tone (Figs. 4,5). The T-receptors, tonic receptors, usually fired one spike during each stimulus cycle with a very constant phase. These receptors can provide information that will allow detection of the presence and the sign of theΔF of beats since the phase of the individual cycles within the beat change in a systematic fashion relative to either pure tone component of the beat (Fig. 3). 3. Posterior Lateral Line Lobe T-cells behaved similarly to T-receptors (Fig. 7). P-cells from this region responded to increases in stimulus amplitude with either an increase (E Type) or a decrease (I Type) in firing frequency. As in the case of P-receptors, no differences in the firing patterns of these P-cells were found when + or −ΔF beats or AM were used as stimuli (Figs. 8,9). 4. Many Torus Semicircularis T-cells responded to beats capable of evoking the jamming avoidance behavior with little or no phase modulation compared to the T-cells seen in antecedent areas. These cells could therefore supply a necessary temporal reference for the evaluation of the changing phase of a beat stimulus relative to one of its pure tone components (Fig. 10). A subset of the Torus P-cells behaved the same as did the Posterior Lateral Line lobe P-cells. The remainder (sign-sensitive cells) showed strikingly different responses to + and −ΔF beats and AM stimuli (Figs. 11, 12, 13). These cells are shown to be sensitive to phase differences between electrical stimuli received at near by regions of the body (Fig. 15). ThisΔF sign sensitivity is only found when stimuli capable of evoking a JAR are used. 5. Mechanisms are proposed to explain the behavior of the sign-sensitive cells which rely on comparison of a reference signal and a beat driven signal supplied by different populations of T-units (Fig. 16). Based on these results, a simple neural circuit is proposed (Fig. 17) which is sufficient to account qualitatively for the known properties of the jamming avoidance behavior.

Microvascular joint transplantation with epiphyseal growth

Abstract: The successful free microvascular transplantation to the hand of a second metatarsal phalangeal joint with associated epiphyses is described, with follow-up data 2 1/2 years later indicating epiphyseal growth.