Tool replacement with adaptive control in a non-stationary non-periodic stochastic process

1991

Abstract The problem of optimum tool replacement is studied in the case in which tool performance is characterized by progressive decay over time following stochastic laws. A control system is assumed which detects, continuously or at fixed intervals, the service state of the tool. Assuming that the service state of the tool affects the marginal cost of production, the latter is used in order to minimize the unit production cost for an unlimited production horizon. The replacement policy proposed is able to update itself in process by means of an iterative procedure which converges to a conditioned optimum. The effectiveness of such a policy is demonstrated analytically, and illustrative ex…

Genetic and biochemical characterization of little isoxanthopterin (lix), a gene controlling dihydropterin oxidase activity in Drosophila melanogaste…

1991

Dihydropterin oxidase catalyses the oxidation of 7,8-dihydropteridines into their fully oxidized products, and is involved in the biosynthesis of isoxanthopterin. Fifteen Drosophila melanogaster mutants, selected for their low pterin and isoxanthopterin content, were assayed for dihydropterin oxidase activity. The activity was around 100% in most mutants tested, slightly reduced in red, g and dke, and undetectable in lix. In flies carrying various doses of the lix+ allele, a correlation was found between enzyme activity and the number of lix+ copies in the genome. The results suggest that lix is the structural gene for the dihydropterin oxidase enzyme. Isoxanthopterin was quantitated in str…

Leaf-like Structure in the Photosynthetic, Succulent Stems of Cacti

1991

This research examined the hypothesis that as cacti evolve to the leafless condition, the stem epidermis and cortex become more leaflike and more compatible with a photosynthetic role. All cacti in the relict genus Pereskia have non-succulent stems and broad, thin leaves. All members of the derived subfamily Cactoideae are ‘leafless’, having an expanded cortex that is the plant's only photosynthetic tissue. In Pereskia, leaves have a high stomatal density (mean: 50.7 stomata mm−2 in the lower epidermis, 38.1 mm−2 in the upper epidermis), but stems have low stomatal densities (mean: 11.3 mm 2, three of the species have none). Stems of Cactoideae have a high stomatal density (mean: 31.1 mm−2,…

Formation rates and protonation constants of azo dyes in a sodium dodecylsulphate micellar solution.

1991

The effects of a sodium dodecylsulphate micellar solution on the coupling rates of several diazotizated arylamines with N-(1-naphthyl)-ethylenediamine and the shifts in the protonation constants of the corresponding azo dyes are quantitatively studied. Aniline, o-, m- and p-aminobenzoic acids, ethyl p-aminobenzoate and several sulphadrugs are used, and the relationships among the intensity of the effects and the molecular structure of the diazonium ions and the dyes are discussed. A single simplified procedure for the determination of all the substances at pH = 1.3 +/- 0.3, where coupling is quickly completed to directly produce the protonated form of the dyes, is established and applied to…

Papular pruritic eruption with human immunodeficiency virus infection.

1991

Androgen receptor assays in specimens of prostatic tissue obtained by transurethral resection and transvesical adenomectomy

1991

The main goal of this study was to ascertain whether routine transurethral resection (TUR) of prostate may provide useful material for the evaluation of androgen receptor (AR) status. At the same time, either intracellular distribution of binding affinity and capacity of receptor molecules were particularly taken into account. Based on our previous findings in breast and endometrial cancer, we suggest that a "functional" receptor status may correspond to the presence of type I (high affinity, low capacity) AR in both soluble and nuclear fractions. However, the precise significance of type II (lower affinity, higher capacity) binding sites remains to be clarified. Ten samples of large prosta…

“Amasa Delano and Christopher Columbus: Meeting the Other with Innocenceand Arrogance in Herman Melville’s ‘Benito Cereno’”

1991

International audience

Solution chemistry of N,N'-ethylenebis(salicylideneimine) and its copper(II), nickel(II) and iron(III) complexes

1991

Abstract Potentiometric determination of protonation-deprotonation equilibria of the N,N'-ethylenebis(salicylideneimine) (H2sal2en), the related N-(2-aminoethyl)salicylideneimine, (Hsalen), and their organic fragments, salicylaldehyde (Hsal) and ethylenediamine (en), has been used to study the equilibria involved in the formation of Schiff bases from Hsal, sal− and en and in their complex formation with copper(II), nickel(II) and iron(III) ions in dimethyl sulfoxide (dmso)-water (80:20 wt./wt.) mixture (25 °C and 0.1 mol dm−3 KClO4 ionic strength): en+Hsal⇔Hsalen; en+2Hsal⇔H2sal2en; en+ sal−⇔salen−; en+2sal−⇔sal2en2−; sal−+en+MN+⇔[M(salen)](n−1)+; 2sal−+en+Mn+⇔ [M(sal2en)](n−2)+. In these t…

A computerized system for measuring time perception in human subjects.

1991

We describe an integrated computerized approach to the design, execution and recording of time perception experiments in human subjects. The program is menu driven and runs on an IBM-compatible microcomputer. The method is easy to use, non-obtrusive to the subjects, and flexible enough to allow the investigator to design studies with a wide range of experimental protocols and study parameters. The fact that the results do not depend on proctor bias or subject-proctor interactions are additional advantages. The technique was applied to study the effects of prompt positive feedback on the time perception of normal human subjects who undergo training. The results of this study are reported.

Structure of the electromagnetic field around the free electron in nonrelativistic QED.

1991

We study, within the framework of nonrelativistic QED, the structure of the electromagnetic field in the neighborhood of a free spinless electron dressed by the interaction with the vacuum field. We introduce a suitable formalism that correlates electron position and field operators. The quantum average value obtained by applying correlated field operator to the dressed state gives the average value of the corresponding field quantity as a function of distance from the electron. The results obtained separately for the electric- and magnetic-field energy density around the particle display contributions that have quantum origin and that cancel in summing of the two, yielding the total energy…

Kronenether mit einem Lewis-sauren Zentrum, eine neue Klasse heterotoper Wirtmoleküle

1991

Asymmetries in classically conditioned head movements and cingulate cortex slow potentials in cats.

1991

Presuming that conditioned head movements in the cat indicate a preference for a specific direction, asymmetries were also expected to be found in bilaterally recorded cingulate cortex slow potentials to a symmetrical tone stimulus during discriminative conditioning. Conditioned stimuli (CS, 1000 and 2500 Hz tones) were delivered through two miniature loudspeakers fitted to the head in front of both ears. The unconditioned stimulus (US) was an electrical stimulation of either the left or right lateral hypothalamus yielding, in addition to its rewarding effects, an unconditioned head turning response (UR) either to the left, right, forwards or upwards. Discrimination learning appeared as mor…

“Editing Out the Narrator: George Roy Hill’s Adaptation of Slaughterhouse-Five”

1991

International audience

Fuzzy control of pH using NAL

1991

Abstract A fuzzy controller for a neutralization process is described. The controller was set up for a laboratory pilot plant. The approach is shown to be effective and can be extended to highly nonlinear and nonstationary processes. The “operator” knowledge encoded in the rules was obtained by several experimental runs of the system using manual control. Rules are composed using the max-min compositional rule of inference. The use of metarules, which depends on controller performance and on active disturbances, makes the controller behave like an adaptive controller. The control program is encoded in NAL, a new experimental logic programming language that was first used in this work in a r…

The First Persistentβ-Silyl-Substituted Vinyl Cation

1991

Bis[indanyl]- and bis[indenyl]arylmethanes: New molecular three-bladed propellers

1991

Proton-catalyzed arylmethylation of indan and indene derivatives with 4-methoxybenzaldehyde yield novel triarylmethanes bearing indan or indene substituents. According to Mislow's definition, these molecules belong to the class of molecular three-bladed propellers and exhibit an interesting stereochemistry.

Effects of whole-body vertical shock-type vibration on human ability for fine manual control

1991

The effects of vertical (z-axis) whole-body shock-type vibration on the ability for fine manual control were examined. The amplitudes and frequency of the shocks was varied, but a constant frequency-weighted acceleration of 1.25 m/s2 r.m.s. was maintained. The examination of the shock's effects was carried out using an experimental system that simulated the actual workplace of earth-moving machinery. Control was measured using a first-order pursuit tracking-test, in which a seated subject was asked to use both hands to direct a cursor on a monitor using a steering wheel. Although the magnitude of shocks (peak amplitude of 6-10 m/s2) and the number of shocks per unit time (shock cycle of 10-…

Formation of arynezirconocenes from substituted diaryl bis (t-butylcyclopentadienyl) zirconium: application to the synthesis of new functionalizedort…

1991

The para-substituted diphenylzirconocenes [(t-BuCp)2Zr(p-C6H4R)2; R = Br, NMe2] (A) were easily obtained from the reaction of the appropriate organolithium reagent with bis(t-butylcyclopentadienyl)zirconium dichloride. Elimination of bromobenzene or N,N-dimethylaminobenzene from A by slight heating led to arynezirconocenes into which were inserted two equivalents of elementary chalcogens. As a result dichalcogenated zirconacycles [(t-BuCp)2ZrY2C6H3R; Y = S, Se] (B) were obtained. Complexes B constitute useful potential synthons in organic synthesis and a large family of new functionalized dichalcogenated benzenic compounds was prepared by reacting electrophiles. The structure of complexes B…

Demographic parameters of Brachionus calyciflorus Pallas (Rotifers) exposed to sublethal endosulfan concentrations

1991

The effects of sublethal levels of endosulfan (0, 1, 1.5, 2.5 and 3.3 mg 1−1) on the demography of the rotifer Brachionus calyciorus were studied. Life expectancy at birth (e o), net reproductive rate (Ro), generation time (T) and intrinsic rate of natural increase (r) were significant differentes between blank controls and controls with acetone. The effective endosulfan concentration at which a given parameter value was reduced to 50% of the controls (EC50) was calculated for life expectancy.

Acquired Ocular Toxoplasmosis

1991

A 31-year-old man exhibited a bilateral deterioration of vision over the course of 1 week. The right fundus showed the picture of a central vein occlusion, and the left of a disseminated choroiditis. Indirect immunofluorescent testing indicated a titer of 1:2048 for toxoplasmosis. Fluorescein angiography revealed a hitherto unique picture of isolated choroidal occlusions but neither a central vein occlusion nor a disseminated choroiditis. Using only specific antitoxoplasmotic therapy, the patient regained full visual acuity on both sides. The original findings and the results of a 14-year follow-up are presented.

Properties of amphiphilic terminally substituted conjugated nonaene- and 2-docosylnonaene carboxylic acids in monolayers at the air-water interface

1991

was a lo-' M Co(NO,), + lo-' M CH,COONa solution, with pH 7.5; the counter electrode was a Pt sheet, conveniently located in the electrochemical cell. After deposition, the electrochemical/electrochromic properties of the films were analyzed in degassed lo-' M KOH electrolyte, in a three electrode cell (Pt wire counter electrode, saturated calomel reference electrode) with optical windows. A PAR 173 potentiostat-galvanostat associated with a PAR 175 function generator was used in the electrochemical experiments. Data were recorded in a analogical X-Y (X-T) recorder. Monochromatic transmission (He-Ne laser, A = 632.8 nm) was recorded in situ, by means of a versatile optical bench; spectral t…

Stability of stationary solutions of a one-dimensional parabolic equation with homogeneous Neumann boundary conditions

1991

for some x in [0, rr]. The guiding idea of this paper is to observe the changes in the stability behavior of the solutions if we perturb the autonomous problem intro- ducing a forcing term g. In [8] it was shown that iff and g are related by a boundedness condi- tion (see condition (* ) in Theorem 3.1) then there exists a stable solution of (1.1) “close” to each stable solution of (1.2). We want to call these stable solutions of (1.1)

C1q-bearing immune complexes detected by a monoclonal antibody to human C1q in rheumatoid arthritis sera and synovial fluids

1991

Using a monoclonal antibody directed against the C-chain of human C1q, we detected C1q-bearing immune complexes (IC) in sera and synovial fluids of rheumatoid arthritis (RA) patients. In a sandwich-ELISA, C1q-bearing IC were captured by the solid-phase monoclonal antibody and then detected with peroxidase-labeled F(ab')2-antibodies to either human IgG or IgM. The results of this assay were compared to an ELISA-modification of the C1q-solid-phase binding assay (C1q-SPBA). C1q-bearing IC were detected in 81.1% of RA-sera and the 65.2% of RA-synovial fluids. IgG as well as IgM was present in 72.6% of the sera and 70% of the synovial fluids which were positive in both assays. Most RA sera that …

Influence of the level of cytosolic epoxide hydrolase on the induction of sister chromatid exchanges by trans-beta-ethylstyrene 7,8-oxide in human ly…

1991

Abstract trans -β-Ethylstyrene 7,8-oxide, a substrate of cytosolic epoxide hydrolase, and 4-fluorochalcone oxide, an inhibitor of this enzyme, were investigated on induction of sister chromatid exchanges (SCE) in human lymphocytes. Both epoxides enhanced the frequency of SCE. 4-Fluorochalcone oxide at low concentration (2.5μM) inhibited cytosolic epoxide hydrolase activity towards trans -β-ethylstyrene 7,8-oxide in lymphocytes by 74% and had no effect on glutathione transferase activity using this substrate. At this concentration it did not induce SCE itself, but it potentiated the effect of trans -β-ethylstyrene 7,8-oxide several fold. In lymphocytes from different subjects, the number of …

?Almost? mean-field ising model: An algebraic approach

1991

We study the thermodynamic limit of the algebraic dynamics for an "almost" mean-field Ising model, which is a slight generalization of the Ising model in the mean-field approximation. We prove that there exists a family of "relevant" states on which the algebraic dynamics αt can be defined. This αt defines a group of automorphisms of the algebra obtained by completing the standard spin algebra with respect to the quasiuniform topology defined by our states. © 1991 Plenum Publishing Corporation.

PFG n.m.r. study of diffusion anisotropy in oriented ZSM-5 type zeolite crystallites

1991

ZSM-5 zeolite crystallites are oriented by introducing them into a system of parallel capillaries. In this way, by applying pulsed-field gradient (PFG) n.m.r., a direct measurement of the orientation dependence of diffusion in ZSM-5 crystals has become possible. Using methane as a diffusant, the ratio D xy /D z between the diffusivities in the xy plane and in the z direction has been found to be of the order of 4.5. This value is in satisfactory agreement with the behavior expected from both MD calculations and a random walk model of molecular propagation in the two-channel network of ZSM-5-type zeolites.

Membrane gangliosides and immuno-mediated cytolysis in drug sensitive and treatment-induced multidrug resistant human ovarian cancer cells

1991

The pattern of cytoplasmic membrane gangliosides and two cellular features which have been reported to be related to the expression of different membrane gangliosides, namely adhesion to solid substrates and susceptibility to the lytic activity of immune effector cells, have been investigated in drug sensitive A2780 human ovarian cancer cells and in two treatment-induced multidrug resistant sublines (A2780-DX1 and A2780-DX3). The total membrane gangliosides content of A2780 sensitive cells was comparable to that of the two multidrug resistant (MDR) sublines, but the acquisition of the MDR phenotype was characterized by an increased expression of the polysialylated gangliosides (particularly…

Das erste persistenteβ-Silyl-substituierte Vinyl-Kation

1991

Elongation and desaturation of arachidonic and eicosapentaenoic acids in rat liver. Effect of clofibrate feeding

1991

The fatty acid elongation-desaturation ability of 5,8,11,14-eicosatetraenoic (20:4(n-6)) and 5,8,11,14,17-eicosapentaenoic (20:5(n-3)) acids was determined in both liver microsomal and light mitochondrial (rich in peroxisomes) fractions of untreated and clofibrate treated rats. The elongation and the subsequent desaturation steps were performed in the corresponding favorable media. 20:5(n-3) elongation was about 2-times more extensive than that of 20:4(n-6). Clofibrate feeding for 10 days resulted in a marked decrease in the elongation rate with the two substrates, while the delta 4 desaturation rate was increased. There were small differences in the elongation rate between the microsomal a…

Restricted and complete-active-space multiconfiguration linear response calculations of the polarizability of formamide and urea

1991

Abstract Using the polarized basis sets of Sadlej, we have carried out multiconfiguration linear response (MCLR) calculations of static and dynamic polarizabilities of water, carbon dioxide, formamide and urea. It is found that the polarized basis sets give a good description of the polarizabilities. The uncorrelates (self-consistent field) polarizabilities are in general 10% or more lower than the experimental values. The correlation as introduced in the complete-active-space (CAS) and restricted-active-space (RAS) MCLR calculations recovers the major part of this deviation.

Peripheral androgen blockade versus glandular androgen suppression in the treatment of hirsutism.

1991

Hirsutism in women is often explained on the basis of abnormal peripheral androgen metabolism. To determine whether serum markers of ovarian, adrenal, or peripheral androgen production may be helpful determinants in the treatment of hirsutism and to compare the efficacy of treatment with dexamethasone or spironolactone, 20 hyperandrogenic hirsute patients were treated for up to 2 years. Eleven women who were selected on the basis of sensitivity to dexamethasone were treated with a daily dose of 0.37 mg dexamethasone and had androgen levels suppressed into the normal range. Although significant (P less than .05), Ferriman-Gallwey scores decreased only by 20%: 14.2 +/- 0.5 to 11.4 +/- 0.6. Ni…

Short and long term results after intracoronary stenting in human coronary arteries: monocentre experience with the balloon-expandable Palmaz-Schatz …

1991

OBJECTIVE--Intracoronary stenting was designed to overcome acute complications after percutaneous transluminal coronary angioplasty and to achieve a reduced rate of restenosis, both of which are major limitations of this well accepted method for treating coronary heart disease. This report describes the experience at one centre with the implantation of balloon-expandable Palmaz-Schatz stents and focuses on device related complications and the short and long term angiographic outcome. DESIGN--A retrospective data analysis. PATIENTS--Stenting was attempted in 50 patients. Restenosis after an initially successful angioplasty procedure, inadequate postangioplasty results, saphenous coronary byp…

Volatiles ofSideritis mugronensisFlower and Leaf

1991

ABSTRACT The composition of the essential oil obtained from the flowers and the leaves of Sideritis mugronensis in two different stages of their reproductive development is described. The major components of the leaf and flower oils were sabinene: 1.30–10.59% and 2.70–15.21%; 1,8-cineole: 11.60–17.19% and 11.06–28.65%; and α-bisabolol: 5.57–25.49% and 3.40–16.12% respectively.

Morphologische Ergebnisse zur Anwendbarkeit eines gepulsten Kryptonfluorid-Excimerlasers im Rahmen der Schmelzkonditionierung

1991

Trotz vieler Fortschritte auf dem Gebiet der Saure-Atz-Technik sind wesentliche Probleme bisher nicht gelost worden. Die Hauptaspekte dieses Problemkreises sind das nicht vorhersagbare Atzmuster, die unkontrollierbare Langzeittiefenwirkung sowie die Entstehung von Schmelzausrissen aufgrund einer nicht definierbaren Bruchflache bei Bracketabnahme. Ziel der vorliegenden Studie ist es, morphologische Ergebnisse der Schmelzkonditionierung bei Verwendung eines gepulsten Kryptonfluorid-Excimerlasers (248 nm) vorzustellen. Die rasterelektronenmikroskopische Untersuchung zeigte ein dem peripheren Saure-Atz-Tup ahnelndes Oberflachenrelief. Zeichen einer Hitzeentwicklung wurden nicht gefunden. Die An…

Evaluation of the healing of precoated vascular dacron prostheses.

1991

Knitted and woven Dacron grafts commercially coated with bovine collagen, gelatin and human albumin were implanted end-to-side between the infrarenal aorta and the bifurcation in 35 growing pigs. Grafts were explanted after 4, 8 and 12 weeks and compared to 6 uncoated knitted prostheses preclotted with blood that served as a control. Uncoated grafts rapidly developed a firmly attached neointima lined with endothelium. Compared with coated grafts the thrombus-free area of uncoated grafts was significantly larger (P less than 0.05). The slow resorption of albumin resulted in a delayed and incomplete neointimal healing and failing graft incorporation. Although the bovine collagen was only mini…

Preliminary analysis of the pentad of 13CH4 from Raman and infrared spectra

1991

Abstract Preliminary results on the simultaneous analysis of infrared and Raman data of 13 CH 4 in the 3-μm region ( ν 1 , ν 3 , 2 ν 2 , ν 2 + ν 4 , and 2 ν 4 ) are presented. The infrared spectrum of 13 CH 4 (90% enriched) has been recorded with the Fourier transform spectrometer at Kitt Peak National Observatory. Line positions have been measured with a relative accuracy of 0.0001 cm −1 (for well-isolated lines) using 0.0118-cm −1 resolution spectra. In order to compensate for the lack of infrared information about low J transitions of vibrational bands forbidden in infrared, two spectra of the ν 1 ( A 1 ) and 2 ν 2 ( A 1 ) Q branches have been recorded in Dijon by inverse Raman spectrosc…