Showing papers by "University College Cork published in 1989"

Nutritional and toxicological aspects of the Maillard browning reaction in foods.

Abstract: The Maillard, or nonenzymatic, browning reaction between carbonyl and amino groups is a common reaction in foods which undergo thermal processing. The Maillard reaction is a desirable consequence of many industrial and domestic processes and is responsible for the attractive flavor and brown color of some cooked foods. An early recognized consequence of the Maillard reaction was the destruction of some essential amino acids, such as lysine. More recently, research interest has focused on the production of toxic and antinutritive compounds. This review examines the nutritional and toxicological consequences of the Maillard reaction in light of the findings of such research. In particular, the effect of Maillard reaction products on the digestion, absorption, and excretion of nutrients is considered. The cytotoxicity, mutagenicity, and immunochemical aspects of selected Maillard reaction products are also examined and suggestions are made for future areas of investigation.

Ireland, 1912–1985: Politics and Society

Abstract: List of maps List of tables Preface Acknowledgements List of abbreviations Note on nomenclature 1. Rebellion: 1912-1922 2. Consolidation: 1922-1932 3. Experiment: 1932-1945 4. Malaise: 1945-1958 5. Expansion: 1958-1969 6. North: 1945-1985 7. Drift: 1969-? 8. Perspectives Select bibliography Index.

A Modified DDE Index for Use in Epidemiological Studies of Enamel Defects

Abstract: The aim of this study was to investigate possible modifications to the DDE Index to make it simpler to use and to make the data collected more meaningful and amenable to analyses and interpretation. After the use of the DDE Index in a National Study in Ireland, initial alterations to the Index were tested on a group of children with enamel defects, in Ireland and New Zealand. The DDE Index was then modified to allow for the measurement of demarcated, diffuse, and hypoplastic defects and their severity. With the Modified Index, the prevalence of defects both on index teeth and all permanent tooth surfaces of 8- and 15-year-old children in fluoridated Cork City and non-fluoridated areas of Cork County and Manchester, U.K., was measured. The prevalence of enamel defects on one or more index teeth of children in the three areas ranged from 30 to 42% in 8-year-olds and from 31 to 38% in 15-year-olds. The percentage of children affected as seen by full-mouth examination was somewhat higher, ranging from 38 to 51% for 8-year-olds and 58 to 63% for 15-year-olds. The percentage of index teeth affected (7 to 14%) was generally higher than for all teeth (5 to 9%). Demarcated opacities were the most common defect seen. Diffuse opacities were found to be the discriminating factor between the fluoridated and non-fluoridated areas. In all areas, the vast majority of diffuse opacities extended over less than 1/3 of the surface area of the teeth affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of oxidised dietary oil and antioxidant supplementation on membrane‐bound lipid stability in broiler meat

Abstract: 1. The effects of oxidised oil, dietary alpha-tocopherol and BHA/BHT-supplementation on the fatty acid composition of mitochondrial, microsomal and soluble protein fractions of broiler muscles, and on their lability to metmyoglobin/hydrogen peroxide-catalysed peroxidation were investigated. 2. Oxidised oil in the broiler diets induced rapid oxidation of the membrane-bound lipids and decreased their stability towards metmyoglobin-hydrogen peroxide-catalysed peroxidation. 3. Supplementation of the broiler diets with alpha-tocopherol increased the alpha-tocopherol concentrations in the microsomal and soluble protein fractions of the dark meat as well as the soluble protein fraction of the white meat. This, in turn, stabilised the membrane-bound lipids against metmyoglobin/hydrogen peroxide-initiated peroxidative changes.

The design of thin-film polysilicon resistors for analog IC applications

Abstract: The authors describe the design of thin LPCVD polysilicon resistors based on their desired electrical performance (sheet resistance, temperature coefficient, voltage nonlinearity, and matching and uniformity). Based on measured data and an understanding of polysilicon carrier transport phenomena, it is shown how resistor processes can be designed for a wide variety of analog IC (integrated circuit) applications, requiring only ion implantation and standard polysilicon deposition and patterning processes. For a +or-500 p.p.m./ degrees C temperature coefficient of resistance range, the available sheet resistance lies between 2400 and 40 Omega /sq. for a polysilicon thickness ranging from 50-600 nm. Matching and nonlinearity (in a 10-V range) to better than 0.06% has been achieved from a process designed as described. Thus it is demonstrated that performance comparable to thin sputtered resistor films can be achieved without the requirement of a long development time and specialized knowledge. >

Differential depuration of poliovirus, Escherichia coli, and a coliphage by the common mussel, Mytilus edulis.

Abstract: The elimination of sewage effluent-associated poliovirus, Escherichia coli, and a 22-nm icosahedral coliphage by the common mussel, Mytilus edulis, was studied Both laboratory-and commercial-scale recirculating, UV depuration systems were used in this study In the laboratory system, the logarithms of the poliovirus, E coli, and coliphage levels were reduced by 186, 29, and 216, respectively, within 52 h of depuration The relative patterns and rates of elimination of the three organisms suggest that they are eliminated from mussels by different mechanisms during depuration under suitable conditions Poliovirus was not included in experiments undertaken in the commercial-scale depuration system The differences in the relative rates and patterns of elimination were maintained for E coli and coliphage in this system, with the logarithm of the E coli levels being reduced by 318 and the logarithm of the coliphage levels being reduced by 087 The results from both depuration systems suggest that E coli is an inappropriate indicator of the efficiency of virus elimination during depuration The coliphage used appears to be a more representative indicator Depuration under stressful conditions appeared to have a negligible affect on poliovirus and coliphage elimination rates from mussels However, the rate and pattern of E coli elimination were dramatically affected by these conditions Therefore, monitoring E coli counts might prove useful in ensuring that mussels are functioning well during depuration

The importance of superficial (adatom) surface oxidation in the electrocatalytic behaviour of noble metals in aqueous media

Abstract: The conventional, activated chemisorption, model of electrocatalysis is unable to explain fully the surprisingly high level of activity of gold anodes in base for certain organic electrooxidation reactions or even the ability of platinum to catalyse certain oxygen insertion reactions, e.g. methanol or formaldehyde oxidation in acid, at low potentials (in the hydrogen or double layer region) where the surface is considered usually to be oxygen-free. It was demonstrated that such behaviour can be rationalized by postulating the involvement of a quite low coverage of hydrous oxide species, generated at low potential at adatom sites, which act as mediators or catalysts in many electrooxidation reactions. The converse situation was also shown to arise, i.e. the reduction of certain species, e.g. HNO3 or NO 3 − , which requires the involvment of adatoms, was shown to be inhibited as long as the latter existed in the oxidized, hydrous oxide, form. An appreciation of hydrous oxide electrochemistry was shown to be very useful in interpreting electrocatalytic effects at noble metal electrodes in aqueous media.

A model for secure information flow

Abstract: A model that characterizes systems that restrict information flow is proposed. The model, called the confinement model, provides greater flexibility in the binding of entities to their security classes than the current static case. A consequence of the nature of security class binding in the confinement model is its ability to enforce nontransitive information-flow policies. A framework of information-flow policies is defined which forms a distributive lattice under operations for policy ordering and combination. It is shown that a state-based MAC (mandatory access) version of the confinement model is the same as a traditional Bell and LaPadula MAC model, except that the confinement model includes a special rule on dynamic class change. >

Uniformly convergent difference schemes for singularly perturbed parabolic diffusion-convection problems without turning points

Abstract: We consider first the initial-boundary value problem for the parabolic equation $$\varepsilon y_{xx} + a(x,t)y_x - b(x,t)y - d(x,t)y_t = f(x,t)$$ on [0, 1]×[0,T], where 0 0,b>0 andd>0. Bounds ony and its derivatives are obtained under certain compatibility assumptions on the data. We examine a family of difference schemes for this problem which is exponentially fitted in thex-variable and uses classical differencing in thet-variable, on rectangular grids which are arbitrarily spaced in both thex andt directions. Under a Courant-Friedrichs-Lewy-type condition, the errors at the grid points are shown to be bounded byC(H+K), whereH(K) is the maximum mesh width in thex(t) direction andC is a constant independent of ɛ,H andK. The corresponding result for a two-point boundary value problem is also derived.

Heat-induced changes in sodium Caseinate

Abstract: Chemical and physical changes that occur in Na caseinate (at 1 or 2% in water, pH 7·0) on heating in the range 120–150 °C were investigated by polyacrylamide gel electrophoresis, ion-exchange and gel-permeation chromatography, light scattering, u.v. spectroscopy, amino acid analysis, and the formation of pH 4·6 and 12% TCA-soluble N and 12% TCA-soluble P. The electropherograms of heated samples were smeared and indistinct suggesting intermolecular aggregation which was not reversed by 6 M-urea or SDS and indicating covalent bond formation; αs2-casein was especially sensitive. Aggregation was confirmed by ion-exchange chromatography and light scattering. Fragmentation of the caseins also occurred on heating, as indicated by the formation of pH 4·6 and 12% TCA-soluble N and by gel filtration. Formation of soluble N and dephosphorylation followed first-order kinetics. Concentrations of available lysine and available methionine were reduced by 10–15% on heating at 140 °C for 30min; chemical assays for arginine and tryptophan indicated increases, suggesting interference. Ultraviolet spectroscopy indicated a slight apparent increase in aromatic residues after heating at 140 °C for up to 60 min.

Glycine tRNA mutants with normal anticodon loop size cause -1 frameshifting.

Abstract: Mutations in the acceptor stem, the 5-methyluridine-pseudouridine-cytidine (TFC) arm, and the anticodon of Salmonella tRNA2Gly can cause -1 frameshifting. The potential for standard base pairing between acceptor stem positions 1 and 72 is disrupted in the mutant sufS627. This disruption may interfere with the interaction of the tRNA with elongation factor-Tu.GTP or an as-yet-unspecified domain of the ribosome. The potential for standard base pairing in part of the TFC stem is disrupted in mutant sufS625. The nearly universal C-61 base of the TFC stem is altered in mutant sufS617, and the TFC loop is extended in mutant sufS605. These changes are expected to interfere with the stability of the TFC loop and its interaction with the D arm. The mutation in mutant sufS605, and possibly other mutants, alters nucleoside modification in the D arm. Three mutants, sufS601, sufS607, and sufS609, have a cytidine substituted for the modified uridine at position 34, the first anticodon position. None of the alterations grossly disrupts in-frame triplet decoding by the mutant tRNAs. The results show that -1 frameshifting in vivo can be caused by tRNAs with normal anticodon loop size and suggest that alternative conformational states of the mutant tRNAs may allow them to read a codon in frame or to shift reading frame.

Heart weight and running ability.

Abstract: The weight of the heart as determined by dissection techniques was compared with liveweight and total muscle weight in different types of horses and dogs as adults and during growth. With increasing body size both within and between species, heart weight forms a lesser proportion of liveweight and of total muscle weight. Heart weight forms a greater proportion of liveweight in Thoroughbreds and Greyhounds (breeds noted for high speed running) than in other less fleet members of their species and Greyhounds have greater heart weights relative to total muscle weight than other dogs.

Binding of zinc to bovine and human milk proteins

Abstract: Zn binding by whole bovine and human casein and by purified bovine caseins and whey proteins was investigated by equilibrium dialysis. Bovine alpha s1-casein had the greatest Zn-binding capacity (approximately 11 atoms Zn/mol). Protein aggregation was observed as Zn concentration was increased and the protein precipitated at a free Zn concentration of 1.7 mM. Zn binding increased with increasing pH in the range 5.4-7.0 and decreased with increasing ionic strength. Competition between Zn and Ca was observed for binding to alpha s1-casein indicating common binding sites for these two metals. Bovine beta-casein bound up to 8 atoms Zn/mol and precipitated at a free Zn concentration of approximately 2.5 mM, while kappa-casein bound 1-2 atoms Zn/mol. Whole bovine and human casein bound 5-8 atoms Zn/mol and precipitated at a free Zn concentration of approximately 2.0 mM. Scatchard plots for Zn binding to caseins showed upward convexity, possibly due to Zn-induced association of caseins. Apparent average association constants (Kapp) for all caseins were similar (log Kapp 3.0-3.2). Enzymic dephosphorylation of alpha s1- or whole bovine casein markedly reduced, but did not eliminate, Zn binding. Thus, phosphoserine residues appeared to be the primary Zn-binding sites in caseins. With the exception of bovine serum albumin, which bound over 8 atoms Zn/mol, the bovine whey proteins, beta-lactoglobulin, alpha-lactalbumin and lactotransferrin, had little capacity for Zn binding.

Zinc binding in bovine milk.

Abstract: About 90% of the Zn in bovine skim milk was sedimented by ultracentrifugation at 100,000 g for 1 h. About half of the non-sedimentable Zn was non-dialysable, indicating that it was associated with protein, probably non-sedimented casein micelles. Casein micelles incorporated considerable amounts of Zn added to skim milk as ZnCl2, and at Zn concentrations greater than or equal to 16 mM coagulation of casein micelles occurred. Ca was displaced from casein micelles by increasing ZnCl2 concentration and approximately 40% of micellar Ca was displaced by 16 mM-ZnCl2. Micellar Zn, Ca and Pi were gradually rendered soluble as the pH of milk was lowered and at pH 4.6 greater than 95% of the Zn, Ca and Pi were non-sedimentable. These changes were largely reversible by readjustment of the pH to 6.7. About 40% of the total Zn in skim milk was non-sedimentable at 0.2 mM-EDTA and most of the remainder was gradually rendered soluble by EDTA over the concentration range 1-50 mM. This indicates that there are two distinct micellar Zn fractions. No micellar Ca or Pi was solubilized at EDTA concentrations up to 1.0 mM, indicating that both colloidal calcium phosphate (CCP) and casein micelles remained intact under conditions where the more loosely bound micellar Zn fraction dissolved. Depletion of casein micelles of colloidal Ca and Pi by acidification and equilibrium dialysis resulted in removal of Zn, and in colloidal Pi-free milk non-dialysable Zn was reduced to 1.2 mg/l (approximately 32% of the original Zn). Thus, approximately 32% of the Zn in skim milk is directly bound to caseins, while approximately 63% is associated with CCP. Over 80% of the Zn in colloidal Pi-free milk was rendered soluble by 0.2 mM-EDTA, indicating that the casein-bound Zn is the loosely bound Zn fraction in casein micelles. A considerable fraction of the Zn in acid whey (pH 4.6) co-precipitated with Ca and Pi on raising the pH to 6.7 and heating for 2 h at 40 degrees C, indicating that insoluble Zn phosphate complexes form readily under these conditions. Studies on dialysis of milk against water, or dilution of milk or casein micelles with water, showed that CCP and its associated Zn is very stable and dissolves only very slowly at pH 6.6. The nature of Zn binding in casein micelles may help to explain the lower nutritional bioavailability of Zn in bovine milk and infant formulae compared with human milk.

Impact of aeration on the metabolic end‐products formed from glucose and galactose by Streptococcus lactis

Abstract: Compared with cultures grown aerobically in batch culture with glucose, aerated cultures of lactic streptococci had a less homolactic type of metabolism when galactose was the carbohydrate source in batch cultures, or when glucose was limiting in chemostat cultures. Differences in end-products of sugar metabolism between aerated and unaerated cultures were observed. In addition to lactate, formate, acetate and ethanol were produced in anaerobic cultures, whereas acetate and acetoin were formed in aerated cultures. Acetate production in aerated cultures depended on lipoic acid, an essential cofactor of the pyruvate dehydrogenase complex. In a chemically defined medium with glucose as the energy substrate, lipoic acid (or acetate) was an essential growth factor. Formation of acetoin was inversely related to lipoic acid concentration in the growth medium. Although not observed in unaerated cultures, acetoin (and 2,3-butanediol) was produced in unaerated buffered suspensions metabolizing pyruvate. Aeration caused a modest increase in the activities of aP-acetolactate synthetase and phosphate acetyl trans-ferase, but it is unlikely that the increases were sufficient to account for the changes in end-products of sugar metabolism observed.

Statistical design techniques for D/A converters

Abstract: Techniques for the design of high-resolution digital-to-analog converters (DACs) that use precision-matched components are described. Statistical models, based on test chip data, that realistically describe both local mismatches and longer range spatial correlations are investigated. These models have been incorporated into a special-purpose DAC analysis/simulation tool (DACSIM) to provide a powerful Monte-Carlo yield estimation capability. DACSIM also performs accurate DC simulation of a large class of resistor-network DAC circuits taking into account many important parasitic effects, including superposition nonlinearities. An error-corrected DAC architecture that uses the concept of a generalised decoding strategy programmable at test has been validated in a CMOS 13 bit segmented current-switched DAC. The approach exhibits the potential for attaining very high accuracy without trimming. >

Nuclear and cytoplasmic gene control of resistance to loose smut (Ustilago tritici (Pers.) Rostr.) in wheat (Triticum aestivum L.)

Abstract: Using disomic chromosome substitution lines based on the susceptible wheat cultivar ‘Chinese Spring’, loose smut resistance of wheat cultivars ‘Hope’ and ‘Thatcher’ was shown to be conferred in each case by a single dominant major gene carried on chromosome 7 A (‘Hope’) or 7 B (‘Thatcher’). Partial resistance was determined by genes on an additional eight ‘Hope’ or seven ‘Thatcher’ chromosomes, and similarities were evident between the partial resistance genotypes of‘Hope’ and ‘Thatcher’. ‘Chinese Spring’ exhibited a mean infection value of approximately 50%, indicating a significant level of partial resistance, which was found to be due, in part, to genes on the homoeologous chromosome arms 1 As, 1 Es and 1 Ds, and to cytoplasmic genes. Substitution of the ‘Chinese Spring’ nucleus into the cytoplasm of Aegilops squarrosa, Ae. variabilis or Ae. mutica resulted in increased susceptibility to Ustilago tritici. Several alloplasmic lines of the resistant wheat cultivars ‘Selkirk’ and ‘Chris’ exhibited race-specific susceptibility to U. tritici.

Some sub-lethal effects of lead on mute swan Cygnus olor

Abstract: Tissue and blood lead levels in mute swans Cygnus olor (Gmelin) were used to investigate sublethal effects of lead. Three categories of swan mortality were defined: (1) acute lead poisoning; (2) collisions; and (3) other reasons. In most tissues, lead concentrations were highest according to the cause of death in order: lead poisoning < collisions < other causes. Elevated blood levels and haematological disorders were detected in swans which had collided with objects. The possible role of elevated lead in causing collisions in mute swans is discussed.

Breeding periodicity and sex ratios in epifaunal marine Amphipoda in Lough Hyne, Ireland

Abstract: Thirteen species of amphipod were recorded from sponges and associated biota, notably algae and tunicates, in Lough Hyne (Ine), south-west Ireland. The sex ratio rarely approached unity in any species. No male Corophium bonnellii were collected. Mature male Lysianassa ceratina were not collected between late July and early September. Ovigerous females occurred throughout the year in five species. Lysianassa ceratina had the most restricted breeding period (May to September). Breeding activity, based on this criterion of reproduction, was generally greatest between April and July, but this period was extended in some species. A secondary autumn peak in breeding activity was recorded in four species. A comparison between the data from the present study and those from a similar study in Scotland suggests that in the case of two of the species, Corophium bonnellii and Lembos websteri, egg production throughout the year may be related to differing summer maximum temperatures.

Axon-myelin relationships in rat cranial nerves III, IV, and VI: a morphometric study of large- and small-fibre classes.

Abstract: The primary objectives of this study were to determine (1) if quantitative axon-myelin relationships are similar for large- and for small-fibre classes within individual nerves and (2) if the same axon-myelin relationships hold for equivalent fibre classes in closely similar nerves. The oculomotor, trochlear, and abducent nerves of the rat were examined since they each contain distinct large- and small-fibre classes and are similar in a wide range of anatomical and developmental respects. Accordingly, morphometric analyses of axon-myelin relationships were performed separately on large and small fibres of each of the three nerves. Within each nerve, the setting of the relationship between the two parameters was found to be different for the two fibre classes: Scatterplots relating sheath thickness to axon perimeter for large fibres were shifted upwards relative to those for small fibres. These differences were also reflected in the positions of the regression lines fitted to the plots and in the g-ratios. Significant differences were found between nerves in relation to their large fibres: Those of the abducent nerve had significantly thicker sheaths, those of the oculomotor nerve had significantly smaller axon perimeters, and the myelin sheath–axon perimeter relationship of the abducent nerve differed significantly from that of the other two. This study therefore shows that morphometric axon-myelin relationships may differ significantly between equivalent fibre classes of nerves that are closely similar in respect of morphological class, central origin, peripheral distribution, developmental environment, and function.

Age changes in axon number along the cervical ventral spinal nerve roots in rats.

Abstract: Axon counts were made at two standardised levels of C7 ventral spinal nerve roots from 46 female rats representing nine ages between birth and 500 days. The objective was to provide a definitive account of proximodistal changes in axon numbers and of age changes in axon numbers both during postnatal development and at several stages during maturity. At each age there is a proximodistal increase in the numbers of axons in all categories examined (myelinated, promyelin, transitional, and fetal) between levels midway along the subarachnoid course of the root and where it is apposed to but separate from the dorsal root ganglion. During maturation and throughout maturity axon totals change similarly at both levels: After a slight increase immediately postnatum, they decline sharply between 4 and 20 days due to a marked loss of unmyelinated axons. A gradual decline in myelinated axon numbers continues to 500 days. While these changes are occurring, axon numbers in all categories show a proximodistal increase throughout. The magnitude of this increase lessens with age for all but the transitional category due to a preferential decrease in numbers distally. Though these observations do not differentiate between axon branching and looping of sensory axons into the ventral root as a cause of the proximodistal increase in numbers, they tend to support the former. At each age during maturation axon proportions at proximal and distal levels correspond well for each animal, indicating that axon segregation proceeds at related rates within each root. Age changes in axon proportions within the transitional and fetal categories indicate that the postnatal stage of axon segregation results from axon loss, rather than Schwann cell proliferation.

Carbon metabolism and catabolite repression in Rhizobium spp.

Abstract: The Gram-negative soil bacteria of the family Rhizobiaceae can fonn nodules on the roots of leguminous plants and as a result are able to fix nitrogen. This partnership is highly specific as particular legumes are generally infected by one rhizobial species only (for example alfalfa by R. meliloti and soybean by B. japonicum'i. The establishment of the symbiosis is a multistepped, interactive process that requires the expression of specific plant and bacterial genes. The sequence of events necessary for symbiotic nitrogen fixation involve recognition, attachment and invasion of the legume by the bacteria, stimulation of plant cell division, multiplication and differentiation of bacteria within plant root cells into morphologically altered forms called bacteroids [1]. Nitrogen fixation by this Rhizobium-legume symbiotic association is a high-energy demanding process. The infected host plant supplies bacteroids

Serum bilirubin levels with antiepileptic drugs.

Abstract: Summary: The incidence of reduced bilirubin levels in 168 outpatients with epilepsy, compared with levels in 69 controls, has been investigated. Highly significant (p < 0.001) reductions in average bilirubin levels were noted for carbamazepine (CBZ), phenytoin (PUT), phenobarbi-tal (PB), and multiple drug groups. A marginally significant (p < 0.05) reduction in bilirubin levels occurred in patients treated with valproate (VPA) which, unlike the other drugs, has not been shown to induce hepatic enzymes. RESUME L'incidence d'un abaissement des taux sanguins de bilirubine chez 168 consultants epileptiques a ete compareee avec les taux observes chez 69 sujets controles. Les taux moyens de Bilirubine etaient tres significativement abaisses (p < 0.001) parmi les patients traites par carbamazepine, phenytoine, phenobarbital et polytherapie. line diminution a peine significative (p < 0.05) des taux de Bilirubine a ete constatee chez les patients traites par valproate, medicament qui, a l'inverse des autres, n'est pas in-ducteur enzymatique. RESUMEN Se ha investigado la incidencia de los niveles de bilirrubina reducida en 168 pacientes con epilepsyia compareandolos con 69 controles. Se observaron reducciones altamente significativas (p < 0.01) en la bilirrubina media, en los tratamientos con carbam-acepina, fenitoina, fenobarbital o multiples drogas. Se encon-traron reducciones marginalmente significativas (p < 0.05) de los niveles de bilirrubina en pacientes tratados con valproate el cual, contrariamente a las otras medicaciones, no ha mostrado ca-pacidad de inducir enzimas hepaticas. ZUSAMMENFASSUNG Die Haufigkeit verminderter Bilirubinwerte bei 168 ambu-lanten Patienten mit Epilepsie und von 69 Kontrollpersonen wurde untersucht. Eine hochsignifikante Reduktion der durchschnittlichen Bilirubinwerte (p < 0.001), wurde bei Car-bamazepin, Phenytoin, Phaenobarbital und Kombinationen ge-funden. Als gering signifikant (p < 0.05) wurden erniedrigte Bilirubinwerte bei Valproattherapie festgestellt. Im Gegensatz zu den anderen Substanzen scheint Valproat keine Enzyminduktion zu bewirken.

Axon numbers in rat oculomotor, trochlear and abducent nerves.

Abstract: In the rat oculomotor, trochlear and abducent nerves, large and small classes of myelinated fibres can be clearly distinguished. Small myelinated axons comprise a larger proportion of the total in the oculomotor nerve than in the other two. Mean counts enable the myelinated preganglionic parasympathetic outflow of the oculomotor nerve to be estimated at 216 fibres. Unmyelinated fibres are most frequent in the abducent nerve and least frequent in the trochlear nerve.

An adaptive uniformly convergent numerical method for a semilinear singular perturbation problem

Abstract: A singularly perturbed semilinear two-point boundary value problem is considered, without any restriction on its turning points. A difference scheme is presented for solving this problem on an arbitrary locally quasi-uniform mesh. It is shown that the solution of the scheme is first-order accurate, uniformly in the perturbation parameter, in a discrete $L^1 $ norm. Numerical results are presented for an adaptive method based on the scheme