Showing papers by "Case Western Reserve University published in 1978"

Design and Testing of a Generalized Reduced Gradient Code for Nonlinear Programming

Abstract: : The purpose of this paper is to describe a Generalized Reduced Gradient (GRG) algorithm for nonlinear programming, its implementation as a FORTRAN program for solving small to medium size problems, and some computational results. Our focus is more on the software implementation of the algorithm than on its mathematical properties. This is in line with the premise that robust, efficient, easy to use NLP software must be written and made accessible if nonlinear programming is to progress, both in theory and in practice.

Diabetes incidence and prevalence in pima indians: a 19-fold greater incidence than in rochester, minnesota

Abstract: The incidence and prevalence of diabetes mellitus were determined in 3733 Pima Indians aged 5 years or over by periodic examinations over a 10-year period. The examinations included modified glucose tolerance tests and medical record review. The age-sex adjusted prevalence rate was 21.1% (SE = 0.7%). Prevalence was low in childhood and plateaued at 40--50% in adults over 35 years of age. The age-sex adjusted incidence rate of 26.5 cases/1000 person-years (SE = 1.9) is the highest reported diabetes incidence known to the authors. Incidence increased from low levels in childhood to peak at age 40 (males) or 50 (females) and then gradually declined. Diabetes incidence was 19 times that in the predominantly white population of Rochester, Minnesota (95% confidence interval, 16 to 22 times). The high incidence rate was found despite using a more stringent diagnostic criterion than customarily employed, and was shown not be due to biased follow-up of subjects.

The Multicomposite Structure of Tendon

Abstract: A revised morphological model for the crimp structure of tendon is presented. The 300-500 mu diameter tendons of the mature rat tail are comprised of from one to more than ten substructures, called fascicles, of 80-320 mu diameter. Fascicles each possess a "crimp structure" demonstrable in the polarizing microscope and neighboring fascicles within a tendon usually exhibit crimp registry. The fascicle itself is shown to be a cylindrical array of planar-zig-zag crimped 500-5000 A diameter collagen fibrils. The approximate cylindrical symmetry of the fascicle is domonstrated by SEM not equal to and polarizing optical microscopy. A method of replacing native water with other liquids of refractive index near to that of collagen is utilized to reduce or eliminate light diffusion and therby greatly improve OM observations. Small bunches of collagen fibrils removed from the tendon are shown to exhibit the simple planar zig-zag morphology described in previous literature. The planar crimping of collagen fibrils and their assemblage into cylindrically symmetric fascicles is verified by small angle X-ray diffraction.

Efferent projections of the subthalamic nucleus: an autoradiographic study in monkey and cat

Abstract: The efferent projections of the subthalamic nucleus were studied with the autoradiographic tracing technique in Rhesus monkey and cat. From the data it appears that the major efferent projections of the nucleus are to the pallidal complex and the substantia nigra. In both monkey and cat, the projection to the pallidal complex is truly massive and is directed at both pallidal segments. The projection field includes an infracommissural part of the pallidal complex bordering on the substantia innominata. In the monkey the termination in the pallidal complex is organized in several characteristic bands oriented parallel to the medullary laminae. The subthalamo-pallidal projection in monkey further appears to be topographically organized. The projections to the substantia nigra is prominent in both cat and monkey though not as massive as that to the pallidal complex. The distribution of termination in the substantia nigra favors the more ventral strata near the cerebral peduncle. In the monkey the terminal distribution appears to avoid regions of the substantia nigra containing pigmented neurons and it is suggested that the subthalamo-nigral pathway may prefer non-dopaminergic neurons. In addition to the above major projections, sparse projections were noted to the thalamic nuclei ventralis lateralis and ventralis anterior, to the putamen, and to the mesencephalic nucleus tegmenti pedunculopontinus, pars compacta. The findings are discussed.

Sexual abuse, another hidden pediatric problem: the 1977 C. Anderson Aldrich lecture.

Abstract: This paper, Sexual Abuse, Another Hidden Pediatric Problem: The 1977 C. Anderson Aldrich Lecture, was published 1978 in Pediatrics. In this paper, C. Henry Kempe sought to broaden attention in child maltreatment work to include child sexual abuse. It forms the basis of the commentaries included in succeeding chapters in this section of the book

The Kinetics of the Oxygen Reduction Reaction on Gold in Alkaline Solution

Abstract: The kinetics of the cathode have been examined on Au in alkaline electrolytes using the rotating ring‐disk method. Only the series mechanism is operative. The cathodic and anodic kinetic data for the couple support the mechanism The further reduction of to OH− is first order in and involves a rate‐controlling step with very little potential dependence.

Suppressor Adherent Cells in Human Tuberculosis

Abstract: Patients with newly diagnosed active pulmonary tuberculosis were divided into high and low responder groups on the basis of 3 H-thymidine incorporation of peripheral blood mononuclear cells (PB MNC) induced by tuberculin-purified protein derivative (PPD). The group of patients with low tuberculin responses was characterized by anergy to tuberculin skin testing and larger numbers of circulating monocytes than the high responders. The groups were comparable in the extent of pulmonary tuberculosis and other clinical parameters. PB MNC from tuberculin low responders had normal phytohemagglutinin (PHA) but depressed streptokinase-streptodornase (SKSD), Candida antigen, and tetanus toxoid-induced 3 H-thymidine incorporation. Depletion of adherent cells resulted in a mean 24.4-fold enhancement of T lymphocyte responses to PPD in the low responders as compared to a 2.9-fold increase in the high responders. The low response of PB MNC from low responders to nonmycobacterial antigens was not similarly augmented by adherent cell depletion. Adding back graded numbers of adherent cells to purified T lymphocyte populations resulted in greater depression of the PPD-induced proliferative response to the tuberculin low responders when compared to the high responders. These studies provide evidence for circulating suppressor adherent cells in tuberculosis patients with diminished responsiveness to PPD in vitro . This immunosuppression is not mediated by adherent cell supernatant products, nor does it involve T lymphocyte labile during culture. However, complex cellular interactions, possibly involving suppressor T cells, are implicated by the restriction of this phenomenon to PPD-induced lymphocyte activation and the depression of the PB MNC responses to nonmycobacterial antigens. The suppressor adherent cells defined in these studies may be relevant as a cause or consequence of infection in a subset of patients with tuberculosis.

Inferential control of processes: Part I. Steady state analysis and design

Abstract: Methods are presented for the design of a static estimator which infers unmeasurable product qualities from secondary measurements. The secondary measurements are selected so as to minimize the number of such measurements required to obtain an accurate estimate which is insensitive to modeling errors. Unlike previous work, the number of secondary measurements can be fewer than the number of unmeasured disturbances. If the statistics of the disturbances and/or measurement noise are available, this information can be incorporated into the design procedure to obtain an optimal static estimator. The design procedure is illustrated by application to a simulated industrial debutanizer. Data for the simulation were supplied by the Marathon Oil Company. Deviations in bottoms product quality are compared for the current control policy (maintenance of a stage temperature at its set point) and the inferential control system with the column subjected to representative feed composition disturbances. Results show that inferential control based on four, five, or six tray temperature measurements improves the steady state control performance by as much as 400%.

The reinforcement mechanism of fiber‐glass reinforced plastics under wet conditions: A review

Abstract: Reinforcement mechanisms of fiber-glass reinforced plastics (FRP) under wet conditions are reviewed with emphasis on molecular structures of glass/matrix interfaces. Included are studies on glass surface, the glass/coupling agent interface, silane coupling agents on glass surfaces as well as in solution, the coupling agent/matrix interface, extending to the interphase of particulate-filled composites, and matrix resin. For a better understanding of wet strength of FRP, the structures under dry conditions are extensively, reviewed. The chemical bonding theory still dominates other reinforcement theories. The importance of other factors such as orientation of silane coupling agents and the restriction of matrix polymer conformations are also considered. Based on recent development in spectroscopy, molecular level research of the glass/matrix interfaces has been initiated in the past decade, yet only a few spectroscopic investigations on the function of water have appeared. It is concluded that the correlation between spectroscopic investigations and mechanical properties of a FRP is indispensable.

The role of ependyma in regeneration of the spinal cord in the urodele amphibian tail

Abstract: The new spinal cord formed during tail regeneration in te newt first develops as a caudal extension of the ependymal tube. Neuroblasts and neuroglia subsequently differentiate from cells of the ependymal tube in a proximal-caudal sweep. Descending axons from the cord rostral to the lesion and from newly differentiating neurons travel in channels which are present prior to the ingrowth of axons. The present study confirms previous observations from our laboratory and presents details of the ultrastructural relations of axons and ependymal processes within the cord. The ependymal cell surface facing channels typically forms numerous digitor sheet-like protuberances which extend into the channel lumen. As axons enter the channels in increasing numbers these protuberances partially subdivide the axons into smaller groupings, even occasionally segregating individual axons. At levels where fibers have not yet entered or have most recently entered the ependymal channels two specializations appear on the ependymal plasmalemma facing the channels and their axons: coated membranes and hemides-mosome-like structures. At more mature levels, where many fibers have already; entered the channels, axons in contact with ependymal processes sometimes show synapse-like vesicle accumulations with associated membrane densities. Coated membranes and hemidesmosome-like structures are lacking at these levels. Our observations suggest that ependymal processes, in addition to providing substrate and direction for regenerating spinal cord axons, may also furnish or exchange more specific information at the morphologically identifiable specializations described above.

Evolution of the nervous system: Role of ontogenetic mechanisms in the evolution of matching populations

Abstract: Nervous systems are composed of populations of cells that are synaptically connected in a highly predictable manner, and we have called two interconnected populations a pair of matching populations. Heritable genetic changes that affect a pair of matching populations can be evolutionary only when this matching quality is not disrupted. We distinguish two types of heritable change. Concordant heritable changes autonomously preserve the match and are thus automatically candidates for what we call type I evolutionary change. Nonconcordant heritable changes, on the other hand, are those that do not autonomously preserve the match. Those nonconcordant heritable changes that can use other normally present ontogenetic mechanisms to preserve the match are candidates for what we call type II evolutionary change. One example of such an ontogenetic mechanism consists of the production of excess neuroblasts and the subsequent weeding out (via cell death) of those that do not successfully match. Because normal ontogeny is an integral part of type II evolutionary change, ontogenetic manipulations can give evolutionary insights. Embryonic graft experiments, in particular, can elucidate the nature of ontogenetic mechanisms that participate in type II changes. Thus, some developmental experiments can be considered to be evolutionary experiments.

Extended Mean Values

Abstract: (1978). Extended Mean Values. The American Mathematical Monthly: Vol. 85, No. 2, pp. 84-90.

On the Nature of the Neurotrophic Phenomenon in Urodele Limb Regeneration

Abstract: The nervous control of regeneration of body parts in the urodele amphibian and other animals has been one of the best model systems for the study of the neurotrophic phenomenon. In the past most of these studies were experimental morphological, but recently the salient problems on the nature of the cellular response to the neurotrophic agent and the nature of the nervous agent itself are also analyzed molecularly. The ensemble of studies reviewed in the present work, which also show that the agent of the nerve is a peptide and defines aspects of its effect on molecular synthesis in regenerate cells, leads me to advance the following theories. I propose that the neurotrophic agent affects only the rate of ongoing events in the cell and not the quality and kind of the events; that the events are already indigenous to the responding cells; that alteration in therate of events, for example increasing the rate of molecular syntheses, yields an increased cell population which by its size and increased cellular interactions has formative and differentiated capabilities which do not exist in a smaller cell population; and finally that the neurotrophic factor (NTF) is one of many “conversational” peptides including nervegrowth factor (NGF) and epidermal growth factor (EGF) which function to alter the absolute rate of ongoing cellular events.

Accuracy of doctors' estimates and patients' statements on adherence to a drug regimen

Abstract: Patients were followed for 2 yr after an attack of peptic ulcer. Intake of an antacid regimen was monitored objectively. Quantitative data were obtained on error in statements about intake (i.e., “compliance”) made by 116 patients and errors in estimates of “compliance” made by 3 physicians. Although patients said their intake of antacid averaged 89% of the amount prescribed, their actual intake averaged only 47%. For patients who claimed they took 100%, intake variedfrom 2% to 130% with a mean of 59%. Patients who admitted missing only an occasional dose actually missed substantially more doses than those who claimed 100% compliance. Estimates of intake made by the 3 physicians were more accurate than patients' statements but averaged 50% higher than actual intakes. In patients with low intakes (median 13%), the median estimate by physicians was 55%—an overestimate of 400%. The correlation between actual intakes and physicians' estimates was +0.48, indicating that physicians' judgements were significantly better than chance but nevertheless low in accuracy. Physicians' accuracy did not improve as they gained familiarity with the patient. Demographic data were of limited value in estimating intake. These observations, along with others cited in the literature, indicate the importance of series of objective and quantitative measures of medicine intake. A single measurement, even though accurate, may be grossly misleading because monthly antacid intake for a given patient could vary from 80% above his mean (2 SD) to 80% below, and daily fluctuation could be even larger.

Stage-specific antibody-dependent eosinophil-mediated destruction of Trichinella spiralis.

Abstract: THE nematode Trichinella spiralis provides a model in which host responses to helminth infection can be studied. In trichinosis, there are three phases against which host resistance might develop. First, resistance may be directed against adult worms in the gut, which develop there after inoculation of the host by infective larvae. Second, resistance may be directed against newborn larvae, which penetrate the gut mucosa and pass by way of the bloodstream to the skeletal muscles. Finally, it may be directed against larvae in the muscle cells, which mature in 2–3 weeks into infective third-stage larvae1. In the study reported here we investigated the ability of white cells to kill each of the three stages of the life cycle of the parasite, that is, adult worms, newborn larvae, and muscle larvae. We describe here an antibody-dependent eosinophil-mediated destruction mechanism specific for the newborn larval stage of T. spiralis.

β→α Transformation in Polycrystalline SiC: I, Microstructural Aspects

Abstract: The effects of annealing conventionally sintered, hot-pressed, and reaction-sintered Sic have been investigated by optical and transmission electron microscopy. In conventionally sintered and hot-pressed bodies, “composite” grains consisting of α-SiC plates sandwiched between recrystallized β-SiC envelopes grow rapidly into the fie-grained β matrix; thickening of these α plates within the p envelopes is relatively sluggish. The existence of the composite plates can be explained by the extreme anisot-ropy of the interfacial energy between β- and α-Sic: {111)β(000l)α interfaces have energies several orders of magnitude lower than random β/α interfaces. In reaction-sintered Sic, this anisotropy is manifested by rapid growth of α seeds along their basal planes into the epitaxial β reaction product; slow growth occurs perpendicular to the basal planes.

Structure-Activity Study of the Inhibition of Microtubule Assembly in Vitro by Podophyllotoxin and Its Congeners

Abstract: This study investigates the inhibition of microtubule assembly in vitro by podophyllotoxin and its derivatives, which include in part the antitumor compounds 4′-demethylepipodophyllotoxin ethylidene β-d-glucoside (VP-16-213) and 4′-demethylepipodophyllotoxin thenylidene β-d-glucoside (VM-26); the cyclic ethers, cyclic sulfides, and cyclic sulfones of podophyilotoxin and deoxypodophyliotoxin; epipodophyliotoxin; picropodophyliotoxin; and several 4′-demethyl compounds. The inhibitory activity of these derivatives is sensitive to the configuration and size of substituents at position 4 in ring C and to steric features of substituents at position 12 in ring D. Decreasing activity correlates with the increasing size of the substituent at position 12, as indexed by their van der Waals radii. These results suggest that rings C and D of these drugs are involved in their interaction with the podophyllotoxin-binding site in tubulin.

Functions of cytoplasmic fibers in intracellular movements in BHK-21 cells.

Abstract: After trypsinization and replating, BHK-21 cells spread and change shape from a rounded to a fibroblastic form. Time-lapse movies of spreading cells reveal that organelles are redistributed by saltatory movements from a juxtanuclear position into the expanding regions of cytoplasm. Bidirectional saltations are seen along the long axes of fully spread cells. As the spreading process progresses, the pattern of saltatory movements changes and the average speed of saltations increases from 1.7 MICROMETER/S during the early stages of spreading to 2.3 micrometer/s in fully spread cells. Correlative electron microscope studies indicate that the patterns of saltatory movements that lead to the redistribution of organelles during spreading are closely related to changes in the degree of assembly, organization, and distribution of microtubules and 10-nm filaments. Colchicine (10 microgram/ml of culture medium) reversibly disassembles the microtubule-10-nm filament complexes which form during cell spreading. This treatment results in the disappearance of microtubules and the appearance of a juxtanuclear accumulation of 10-nm filaments. These changes closely parallel an inhibition of saltatory movements. Within 30 min after the addition of the colchicine, pseudopod-like extensions form rapidly at the cell periphery, and adjacent organelles are seen to stream into them. The pseudopods contain extensive arrays of actinlike microfilament bundles which bind skeletal-muscle heavy meromyosin (HMM). Therefore, in the presence of colchicine, intracellular movements are altered from a normal saltatory pattern into a pattern reminiscent of the type of cytoplasmic streaming seen in amoeboid organisms. The streaming may reflect either the activity or the contractility of submembranous microfilament bundles. Streaming activity is not seen in cells containing well-organized microtubule-10-nm filament complexes.

Fourier transform infrared spectroscopic study of the structure of silane coupling agent on E-glass fiber

Abstract: Infrared spectra of silane coupling agents deposited on E-glass fiber were obtained by Fourier transform infrared spectroscopy (FT-IR). A spectral subtraction technique resolved all vibrational modes of the coupling agent deposited from various concentrations of treating solutions. The amount of vinyl functional coupling agent was determined by measuring the integrated peak intensities of the organic functional group. It revealed that the thickness of the coupling agent layer on the glass fiber depended on the concentrations of the treating solution. The rates of condensation reaction of polysiloxanol with and without glass fiber were followed. The coupling agent on the glass fiber reacted much faster than without glass at room temperature. It was concluded that the coupling agent molecules near the glass fiber surface have some order and can easily participate in the condensation reaction. The carbonyl group of a methacryl functional silane hydrogen bonds with hydroxyl groups. The methacryl functional silane on the glass fiber showed less hydrogen bonded groups than the precipitated polysiloxanol suggesting a mechanism of predominant head-to-head adsorption.

Hemifacial spasm and the facial nucleus

Abstract: Spontaneous and associated hyperkinetic facial movements and contracture which follow injury to the seventh cranial nerve (postparalytic hemifacial spasm) or arise without known previous injury (cryptogenic hemifacial spasm) are pathological motor phenomena not found in the distribution of other cranial or somatic motor nerves. The commonly expressed hypotheses of pathogenesis--aberrant regeneration and fiber excitation by false synapse formation (ephapses) at the site of injury--cannot account for all aspects of these phenomena or for the uniqueness of such movements to the distribution of the seventh nerve. The suggestion is made that the existing diversity of facial motor behavior, which encompasses voluntary, emotional, and especially automatic, associated, and reflexive movements, is based on a unique central organization that sets it apart from other motor groups. I hypothesize that because of this organization, the changes following axonal injury--which include selective deafferentation, glial response, axonal sprouting, functional reconnection, and hyperexcitability from dendritic spike generation--can unmask and augment automatic, associated, and reflexive movements already present in the facial neuronal network to result in facial hyperkinesia.

Impurity Phases in Hot-Pressed Si3N4

Abstract: Impurity phases in commercial hot-pressed Si3N4 were investigated using transmission electron microscopy. In addition to the dominant, β-Si3N4 phase, small amounts of Si2N2O, SiC, and WC were found. Significantly, a continuous grain-boundary phase was observed in the ∼ 25 high-angle boundaries examined. This film is ∼ 10 A thick between, β-Si3N4 grains and ∼ 30 A thick between Si2N2O and β-Si3N4 grains.

Prevalence and possible etiology of dental enamel hypoplasia.

Abstract: Two hundred black and white adult human skeletons and 200 living black and white children from the greater Cleveland area were examined for evidence of enamel hypoplasia. Enamel hypoplasia, present in varying expressions (pits, lines and grooves), was found to be more prevalent in both skeletal samples, than in the living groups. In the majority of cases, sex differences between white and black males and females through time and space are highly significant for all tooth categories. Regardless of the mechanisms behind it, prevalence of enamel hypoplasia for both white and black groups has significantly declined through time. No evidence suggesting specific etiologies responsible for enamel hypoplasia can be found. In the majority of previously published reports, the etiology is still idiopathic. The reduction in the prevalence of enamel hypoplasia in the groups examined through time may be related to improved nutritional conditions and the elimination or decline of childhood diseases that have been implicated in this condition.