Showing papers by "Case Western Reserve University published in 1984"

Choking under pressure: Self-consciousness and paradoxical effects of incentives on skillful performance

Abstract: Choking under pressure is defined as performance decrements under circumstances that increase the importance of good or improved performance. A model for choking on coordination and skill tasks is proposed, holding that the pressure increases the conscious attention to the performer's own process of performance and that this increased conscious attention disrupts the automatic or overlearned nature of the execution. Six experiments provided data consistent with this model. Three studies showed that increased attention to one's own process of performance resulted in performance decrements. Three other studies showed similar decrements produced by situational manipulations of pressure (i.e., implicit competition, a cash incentive, and audience-induced pressure). Individuals low in dispositional self-consciousness were shown to be more susceptible to choking under pressure than those high in it.

A Model of the Distributor's Perspective of Distributor-Manufacturer Working Relationships:

Abstract: Building upon work from social exchange theory and channels of distribution, a model of distributor-manufacturer working relationships from the distributor's perspective is presented. An initial em...

Endothelial and smooth muscle cells alter low density lipoprotein in vitro by free radical oxidation.

Abstract: Our purpose was to determine whether the action of oxidative free radicals released by endothelial cells and vascular smooth muscle cells grown in culture could be responsible for certain modifications to low density lipoprotein (LDL). In these experiments we showed that after a 48-hour incubation with human umbilical vein endothelial cells or bovine aortic smooth muscle cells, human LDL: 1) became oxidized, as evidenced by reactivity to thiobarbituric acid; 2) lost variable amounts of sterol relative to protein (up to 20%); 3) had an increased relative electrophoretic mobility (by 30% to 70%); and 4) became toxic to proliferating fibroblasts. None of these changes occurred after a 48-hour incubation with confluent fibroblasts or bovine aortic endothelial cells, and all could be virtually prevented by the presence of butylated hydroxytoluene or other free radical scavengers. The results suggest that cells modifying LDL do so in part by an oxidation of LDL subsequent to cellular generation of free radicals.

Families caring for elders in residence: issues in the measurement of burden.

Abstract: This paper examines the concept of caregiving burden and urges a multidimensional perspective in which burden is viewed as a mediating force between the elders' impairments and the impact that caregiving has on the lives of caregivers and their families. The analysis underscores the need to apply the concept of burden to subjective interpretations by caregivers of the elders' different kinds of impairments including impairment of activities of daily living, cognitive incapacity, disruptive behavior, and lack of sociability. The analysis also demonstrates that a variety of less subjective effects of caregiving are important and measureable. These issues are elaborated and illustrated using data and findings from the Benjamin Rose Institute's survey of 614 families in which impaired elders resided with and were provided care by family members.

Preschoolers with language disorders: 10 years later.

Abstract: Language, intelligence, academic achievement, and behavioral adjustment were assessed in a group of 20 adolescents originally studied 10 years earlier as preschoolers with language disorders. At follow-up, 20% had WISC-R IQ scores in the mentally deficient range and were being educated in EMR classrooms. Of the remaining 16, 11 (69%) had required special tutoring, grade retention, or LD class placement. The majority of non-EMR subjects continued to evidence persistent deficits in language and academic achievement and were rated by their parents as being less socially competent and having more behavioral problems than their peers. Of the initial preschool measures available, the Leiter was found to be the best single predictor of intelligence, language, class placement, and reading achievement in adolescence, although the NSST: Expressive subtest also was a strong predictor of adolescent language.

Implantable cuff, method of manufacture, and method of installation

Abstract: A self-curling sheet (A) of non-conductive material is biased to curl into a tight spiral. A cut out (22) is removed from one corner of the sheet such that, when the sheet spirals, a passage (28) defined axially therethrough has one portion with a smaller diameter and another portion with a larger diameter. A pair of conductive strips (40, 50) are disposed on the self-curling sheet such that one extends peripherally around each of the larger and smaller diameter regions of the passage therethrough. The conductive segments may be electrically conductive for applying electrical impulses or fluid conductive for infusing medications. In use, a first edge (14) of the self-curling sheet is disposed adjacent a nerve trunk which is to receive the cuff therearound. The self-curling sheet is controllably permitted to curl around the nerve forming an annular cuff therearound.

A New Look at Porous Media Fluid Mechanics — Darcy to Turbulent

Abstract: The purpose of this review paper is to present the results of laser anemometry and flow visualization studies of the flow of liquids in porous structures. Three dimensional velocity profiles and movies of dye streaklines will be shown. The porous media consisted of plexiglas spheres in a hexagonal packing and glass and plexiglas rods arranged in a complex, fixed three dimensional geometry. The liquids used were water, silicone oils, Sohio MDI-57 oil and mineral seal oil. The Reynolds number based on average pore size and average pore velocity ranged from 0.16 to 700.

Asymmetric single electrode cuff for generation of unidirectionally propagating action potentials for collision blocking

Abstract: A single electrode, asymmetric electrode cuff (B) is disposed around a nerve trunk (A). A signal generator (C) is connected between a cathode (20) disposed asymmetrically in the electrode cuff and an anode (22) disposed in an electrically conductive relationship within the body tissue. The signal generator applies a stimulus signal (FIG. 3) which generates unidirectionally propagating action potentials on the nerve trunk. The electrode cuff includes a dielectric sleeve (10) in which the cathode is positioned a first distance (L1) from an escape end (14) and a second distance (L2) from an arrest end (16). The first distance is at least 1.7, and preferably about 7, times the second distance. This asymmetry causes a primary or forward stimulus signal current (30) to be correspondingly greater than a secondary or reverse current (32).

Physical Properties of Polymers

Abstract: The third edition of this well known textbook discusses the diverse physical states and associated properties of polymeric materials. The contents of the book have been conveniently divided into two general parts, 'Physical States of Polymers' and 'Characterization Techniques'. Written by seven of the leading figures in the polymer science community, this third edition has been thoroughly updated and expanded. As in the second edition, all of the chapters contain general introductory material and comprehensive literature citations designed to give newcomers to the field an appreciation of the subject and how it fits into the general context of polymer science. Containing numerous problem sets and worked examples this third edition provides enough core material for a one semester survey course at the advanced undergraduate or graduate level.

Effect of warfarin anticoagulation on survival in carcinoma of the lung, colon, head and neck, and prostate. Final report of VA Cooperative Study #75.

Abstract: VA Cooperative Study #75 was established to test in a controlled, randomized trial the hypothesis that warfarin anticoagulation would favorably affect the course of certain types of malignancy. No differences in survival were observed between warfarin-treated and control groups for advanced non-small cell lung, colorectal, head and neck and prostate cancers. However, warfarin therapy was associated with a significant prolongation in the time to first evidence of disease progression (P = 0.016) and a significant improvement in survival (P = 0.018) for patients with small cell carcinoma of the lung, including the subgroup of patients with disseminated disease at the time of randomization (P = 0.013). A trend toward improved survival with warfarin treatment was observed for the few patients admitted to this study with non-small cell lung cancer who had minimal disease at randomization. These results suggest that warfarin, as a single anticoagulant agent, may favorably modify the course of some, but not all, types of human malignancy, among which is small cell carcinoma of the lung. Further trials of warfarin may be indicated in patients with limited disease who have cell types that failed to respond when advanced disease was present.

Paradoxical effects of supportive audiences on performance under pressure: The home field disadvantage in sports championships.

Abstract: On the basis of recent research on self-presentation and self-attention, we predicted that the presence of supportive audiences might be detrimental to performance in some circumstances. Specifically, the imminent opportunity to claim a desired identity in front of a supportive audience might engender a state of self-attentio n that could interfere with the execution of skillful responses. Archival data from championship series in two major league sports supported this reasoning. In baseball's World Series, home teams tend to win early games but lose decisive (final) games. Supplementary analyses suggested that the pattern occurs when the home team has the opportunity to win the championship and that it does involve performance decrements by the home team. Similar patterns were found in semifinal and championship series in professional basketball. The present study concerns whether the presence of supportive versus unsympathetic audiences could interact with opportunities for claiming desired identities to cause paradoxical decrements in the quality of performance. Researchers of self-presentation have used terms such as audience and performance to describe self-presentation ever since Goffman's (1959) dramaturgical analysis of behavior. Our study seeks to test self-presentational hypotheses in the context of actual professional performers and their audiences. We chose professional athletic contests because they provide circumscribed, quantifiable performances and because careful records are generally kept. Our hypotheses were derived by the three steps that follow.

Axonal transport of the cytoplasmic matrix.

Abstract: The cytoplasmic matrix is often highly specialized, making it possible to clearly relate particularaspects ofthe cytoplasmic matrix to the specialized functions of cells . For example, in striated muscle cells the contractile components of the cytoplasmic matrix dominate the cell structurally and functionally. Neurons are another example of cells in which specializations of structure and function can be clearly related to particular aspects of the cytoplasmic matrix (36, 37) . The primary function of neurons is to convey information from one location in the organism to another. Pathways for information transfer in the nervous system are provided by specialized neuronal extensions, the axons and the dendrites . Axons, in particular, are specialized to convey information over very long distances, meters in some cases . Accordingly, in the axon the cytoplasmic matrix is specialized to generate and support the extremely elongate shape ofthe axon during development, regeneration, and maturity. To generate and maintain the great volume of cytoplasm within the axon, neurons must produce tremendous amounts of protein (32) . Essentially all axonal proteins are synthesized in the neuron cell body and then conveyed into the axon by axonal transport, which provides a lifeline for the axon and its terminus (25, 36) . Axonal transport is a process that is initiated when the axon first develops and that continues throughout the life of the neuron . To meet the needs of large animals, which require long axons, axonal transport has become one of the most highly developed mechanisms for the intracellular transport of materials in metazoan cells .

A silicon phthalocyanine and a silicon naphthalocyanine: synthesis, electrochemistry, and electrogenerated chemiluminescence

Abstract: : The synthesis, spectral characterization, and electrochemical behavior of bis(tri-n-hexylsiloxy)-2,3-phthalocyaninatosilicon (SiPc(OR)2), its dimer (RO(SiPcO)2R), and its naphthalocyanine analog (SiNc(OR)2) are described. All compounds show near UV absorption corresponding to Soret and N bands and intense absorption in the visible-near IR region corresponding to Q-bands. In CH2Cl2, within the solvent stability limit, there are two reductions and one oxidation for SiPc(OR)2 and two reductions and two oxidations for RO(SiPcO)2R and SiNc(OR)2; all appear as reversible one electron waves, although n=2 for the dimer. The difference in the peak potentials of the first oxidation and first reduction waves agrees well with the excitation energy and fluorescence (corresponding to Q-bands) of SiPc(OR)2 and SiNc(OR)2.

Developmental biology of a neural cell adhesion molecule

Abstract: A membrane glycoprotein isolated from embryonic brain has been shown to be a ligand in the formation of cell-cell bonds. The molecule, called neural cell adhesion molecule (N-CAM), participates in several aspects of neural development, including the formation of plexiform layers, neurite fasciculation and nerve-muscle interactions. Experiments in vivo indicate that N-CAM-mediated adhesion is essential to the orderly assembly of the visual system.

A review of recent progress in the studies of molecular and microstructure of coupling agents and their functions in composites, coatings and adhesive joints

Abstract: Recent progress in the studies of molecular and microstructure of interfaces and interphases in composites, coatings, and adhesive joints is reviewed. Remarkable progress has been made in elucidating the structure of silane coupling agents and their function with respect to dry and wet strengths of multiphase systems. Aminosilanes attracted major effort in the past. It is now understood that the structure of partially cured hydrolyzate is complicated. When adsorbed from a natural pH solution and dried in air at room temperature, approximately half of the amine groups form amine bicarbonate salt with the CO2 in air. The rest of the amine groups are either intra- and intermolecularly hydrogen bonded to neighboring silanol groups or free from hydrogen bonding. There exists chemical bonding at the glass/silane or metal/silane interfaces. The surface characteristics, including acidity, topology and homogeneity, influence the structure of the coupling agent. The coupling agent interphase shows a gradient in various properties. Silanes tend to be ordered in the interphase and the degree of organization depends largely on the organofunctionality. The orientation and organization of the silane affects the reinforcement mechanism. There are chemisorbed and physisorbed silanes in the interphase. The coupling agent/matrix interface is a diffuse boundary where intermixing takes place due to penetration of the matrix resin into the chemisorbed silane layers and the migration of the physisorbed silane molecules into the matrix phase. With proper selection of the organofunctionality and the curing conditions, silanes can chemically react with the matrix to form copolymers. The existence of the matrix interphase is now well accepted and the effect of the interphase on the mechanical properties has been studied. It has been recognized that modification of the matrix interphase, such as a coating applied on the fiber using a similar resin as the matrix, has a complex effect on the mechanical performance. It is noteworthy that attempts to synthesize new coupling agents and to utilize the existing coupling agents more effectively still continue. Based on the molecular understanding, new concepts in the reinforcement mechanism have appeared which recognize the importance of interpenetrating networks, the structure of silane in the treating solution, and the microheterogeneity of the glass surfaces. The knowledge obtained through the studies of composites can be applied to organic coatings and adhesive joints provided that the geometrical factors are taken into consideration.

Disseminated fungal infections in very low-birth-weight infants: clinical manifestations and epidemiology.

Abstract: In 1979 and 1980, an apparent increase in the occurrence of disseminated fungal infections was observed. The clinical features of such infections in very low-birth weight infants are poorly described, and diagnosis is often delayed. Over a 24-month period, a discrete group of ten clinically diagnosed and four autopsy-diagnosed cases of systemic fungal infections in very low-birth-weight infants was observed. Prior to developing systemic fungal illness, these infants required prolonged total parenteral nutrition, central arterial or venous catheters, and multiple courses of broad-spectrum antibiotics for documented or suspected bacterial sepsis. The clinically diagnosed disseminated fungal infection (ten infants) was noted at a mean age of 33 days with one or more of the following: respiratory deterioration, abdominal distension, guaiac positive stools, carbohydrate intolerance, candiduria, endophthalmitis, meningitis, abscesses, erythematous rash, temperature instability, and hypotension. These signs and symptoms were seen as chronic or were intermittent in clinical course. In contrast, the autopsy-diagnosed disseminated fungal infection (four infants) was present at an earlier age with fewer recognizable predisposing factors and a more acute onset of infection. Nevertheless, in both groups the diagnosis of systemic candidal infection was delayed, due to an inability to consistently recover the organism from blood, CSF, or urine. The neonatologist caring for the very low-birth-weight infant needs to become more aware of these clinical entities. A high index of suspicion and ancillary diagnostic evaluation, such as retinoscopy or tissue biopsy, may be indicated in the critically ill, culture-negative patient.

Antidromic pulse generating wave form for collision blocking

Abstract: An electrode cuff (B) including a dielectric sleeve (10) and an annular cathode electrode (20) is disposed around a nerve trunk (A). An anode electrode (22) is disposed in body fluids in electrical communication with the nerve trunk. The cathode electrode is disposed off center within the dielectric sleeve. The flow of electric current from the anode to the cathode has a much greater amplitude along the nerve in the direction extending along the nerve trunk toward the cathode from the end of the dielectric sleeve toward which the cathode electrode is closest. A signal generator (C) applies a pulse train across the anode and cathode electrodes. The pulse train includes a plurality of alternating first amplitude pulse portions (40) and opposite polarity pulse portions (42). Each first polarity pulse includes a sharp leading edge (50) which rises abruptly to a preset amplitude (52). A trailing edge (56) of each first pulse portion decays smoothly into a leading edge (60) of each opposite polarity pulse portion without a discontinuity therebetween. The opposite polarity pulse portion has an amplitude (62) which is smaller than the triggering amplitude and a duration which is longer than the first polarity pulse portion duration. The amplitude and duration of the first and opposite polarity pulse portions are selected such that the net charge transfer in each direction is substantially the same.

An epidemiologic and clinical evaluation of guillain-barré syndrome reported in association with the administration of swine influenza vaccines

Abstract: As a result of a court order, computerized summaries of approximately 1,300 cases reported as Guillain-Barre syndrome by state health departments to the Centers for Disease Control during the intensive national surveillance instituted following the swine influenza vaccination program in 1976-1977 became available for further study. Although the data were not uniformly adequate to confirm the diagnosis of Guillain-Barre syndrome, they were sufficient to enable classification according to extent of motor involvement. Vaccinated cases with "extensive" paresis or paralysis occurred in a characteristic epidemiologic pattern closely approximated by a lognormal curve, suggesting a causal relationship between the disease and the vaccine. Cases with "limited" motor involvement showed no such pattern, suggesting that this group included a substantial proportion of cases which were unrelated to the vaccine. The effect attributed to the vaccine lasted for at least six weeks and possibly for eight weeks but not longer. The relative risk of acquiring "extensive" disease over a six-week period following vaccination ranged from 3.96 to 7.75 depending on the particular baseline estimate of expected normal or endemic incidence that was chosen. Correspondingly, the number of cases that could be attributed to the vaccine over the six-week period ranged from 211 to 246, or very slightly higher over an eight-week period if the lowest baseline estimate was used. The total rate of Guillain-Barre syndrome cases attributed to prior use of the vaccine was 4.9 to 5.9 per million vaccinees.

Urinary Excretion of l -Carnitine and Acylcarnitines by Patients with Disorders of Organic Acid Metabolism: Evidence for Secondary Insufficiency of l -Carnitine

Abstract: Urinary Excretion of l -Carnitine and Acylcarnitines by Patients with Disorders of Organic Acid Metabolism: Evidence for Secondary Insufficiency of l -Carnitine

Evaluation of the total fetomaternal vitamin D relationships at term: evidence for racial differences.

Abstract: The present study assessed the total fetomaternal vitamin D relationship at term in 12 white and 10 black mothers and their infants Antirachitic sterols were extracted from plasma, chromatographed, and finally quantitated using competitive protein binding assays Compounds quantitated included vitamins D2 and D3, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3, 24,25-dihydroxyvitamin D2, 24,25-dihydroxyvitamin D3, 25,26-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D2, and 1,25-dihydroxyvitamin D3 There was a strong correlation between maternal and neonatal plasma concentrations of all antirachitic sterols measured with the exception of vitamins D2 and D3 Vitamins D2 and D3, although detectable in maternal plasma, were undetectable in neonatal plasma Racial comparisons demonstrated that vitamin D3, 25-hydroxyvitamin D3, 24,25-hydroxyvitamin D3, and 25,26-(OH)2-D3 were significantly (P less than 005) higher in white than in black mothers Total 25-hydroxyvitamin D and 24,25-hydroxyvitamin D were also significantly (P less than 005) higher in white than in black mothers A similar pattern was found in black and white infants except for 25,26-(OH)2-D3 Black mothers and their infants had significantly (P less than 005) higher 1,25-hydroxyvitamin D3 compared to the white subjects, although total 1,25-hydroxyvitamin D was not different between races No significant racial (P greater than 005) differences were found for any of the vitamin D2 compounds The results support the concept that fetomaternal vitamin D status are intimately related Further, they strongly suggest that fetal metabolism begins with 25-hydroxyvitamin D rather than vitamin D Finally, racial factors appear to influence the overall vitamin D status of both mother and fetus, and may influence antirachitic sterol metabolism

Increased incidence of thromboembolism in stage IV breast cancer patients treated with a five-drug chemotherapy regimen

Abstract: We report an incidence of thrombosis of 17.6% in 159 patients treated with a five-drug chemotherapy regimen (cyclophosphamide, methotrexate, 5-fluorouracil, vincristine, and prednisone) for Stage IV breast carcinoma. Chi-squared analysis of risk factors for thrombosis (ambulatory status, obesity, family history, smoking, diabetes mellitus, hypertension, liver dysfunction, thrombocytosis, and previous endocrine therapy) showed no difference between the patients who had a thromboembolic event and those who did not. Statistical analysis revealed that a significantly higher incidence of thrombosis occurred during the chemotherapy regimen than when off this regimen (P less than 0.05). Detailed coagulation studies done prospectively on 10 patients receiving the five-drug chemotherapy regimen compared with 10 control patients showed a significantly elevated Factor VIII antigen:activity ratio in the group receiving the chemotherapy regimen compared with the control group and normals. These results implicate the chemotherapeutic regimen in the pathogenesis of the increased incidence of thrombosis. The pathophysiology of thrombosis in settings such as this awaits better in vitro tests defining the "hypercoagulable state."

Collagen Aging In Vitro by Nonenzymatic Glycosylation and Browning

Abstract: Aging and diabetes meliitus are associated with crosslinking and nonenzymatic glycosylation of collagen. Incubation of tendon fibers with reducing sugars results in increased breaking time in urea similar to that seen in aging, and in nonenzymatic glycosylation and browning. Effect of a sugar is proportional to the amount of sugar available in the open chain form. The increase in breaking time correlates with the appearance of chromophores characteristic of crosslinked browning products. Collagen altered by nonenzymatic browning may play a role in some age-like major complications Of diabetes.

Respiratory function of hyoid muscles and hyoid arch

Abstract: The position of the hyoid arch suggests that it supports soft tissue surrounding the upper airway (UA) and can act to maintain UA patency. We also suspected that muscles inserting on the hyoid arch might show respiratory patterns of activity that could be affected by respiratory stimuli. To test these possibilities, we moved the hyoid arch ventrally in six anesthetized dogs either by traction on it or by stimulation of hyoid muscles. UA resistance was decreased 73 +/- (SE) 6% and 72 +/- 6% by traction and stimulation during expiration and 57 +/- 15% and 52 +/- 8% during inspiration. Moving averages of the geniohyoid (GH) and thyrohyoid (TH) obtained in six other dogs breathing 100% O2 showed phasic respiratory activity while the sternohyoid (SH) showed phasic respiratory activity in only two of these animals and no activity in four. With progressive hypercapnia, GH and TH increased as did SH when activity was already present. Airway occlusion at end expiration augmented and prolonged inspiratory activity in the hyoid muscles but did not elicit SH activity if not already present. Occlusion at end inspiration suppressed phasic activity in hyoid muscles for as long as in the diaphragm. After vagotomy activity increased and became almost exclusively inspiratory. Activity appeared in SH when not previously present. Duration and amplitude of hyoid muscle activity were increased with negative UA pressure and augmented breaths. We conclude that the hyoid arch and muscles can strongly affect UA flow resistance. Hyoid muscles show responses to chemical, vagal, and negative pressure stimuli similar to other UA muscles.