Showing papers by "University College Cork published in 1992"
TL;DR: The understanding of the relevant characteristics will facilitate the direct selection and/or construction of strains which will perform under a variety of environmental conditions, and facilitate attempts aimed at the improvement of strains based on deregulating pathways or introducing traits from one strain to another.
646 citations
TL;DR: Pseudomonas sp.
Abstract: Pseudomonas sp. strain F113 was isolated from the rhizosphere of sugar beets and shown to inhibit a range of plant pathogenic fungi by producing an antibioticlike compound. An antibiotic-negative mutant strain, F113G22, was generated by transposon mutagenesis. This mutant has lost the ability to inhibit both bacterial and fungal microorganisms on high-iron medium. The antibioticlike compound was subsequently identified as 2,4-diacetylphloroglucinol (DAPG), and a high-pressure liquid chromatographic assay was developed for to detect it quantitatively in growth culture media and soil. The growth temperature had a direct bearing on DAPG production by strain F113, with maximum production at 12 degrees C. The iron concentration, pH, and oxygen had no influence on DAPG production by strain F113 under the assay conditions used. However, a low ratio of culture volume to surface area available to the microbe in the growth container was critical for optimum DAPG production. Different types of carbon sources influenced DAPG production by strain F113 to various degrees. For example, sucrose, fructose, and mannitol promoted high yields of DAPG by strain F113, whereas glucose and sorbose resulted in very poor DAPG production.
516 citations
TL;DR: Strain M114(pCU203) showed enhanced antagonism towards P. ultimum in vitro and significantly increased the emergence of sugar beet seeds in the same soil compared with emergence induced by the parent strain M114.
Abstract: Tn5 mutagenesis and complementation analysis were used to clone a 6-kb genomic fragment required for biosynthesis of 2,4-diacetylphloroglucinol (Phl) from fluorescent Pseudomonas sp. strain F113. A recombinant plasmid, pCU203, containing this region partially complemented a Phl production-negative mutant (F113G22) derived from strain F113. When sugar beet seeds were sown into an unsterilized soil, in which sugar beet was subject to damping-off by Pythium ultimum, the emergence of sugar beet seeds inoculated with strain F113 was significantly greater than that of seeds inoculated with F113G22. Transfer of pCU203 into eight other Pseudomonas strains conferred the ability to synthesize Phl in only one of these strains, Pseudomonas sp. strain M114. Strain M114(pCU203) showed enhanced antagonism towards P. ultimum in vitro and significantly increased the emergence of sugar beet seeds in the same soil compared with emergence induced by the parent strain M114.
325 citations
TL;DR: In this article, a method for monitoring the terminal stages of proteolysis in cheese, i.e. the formation of free amino acids, using the Cd-ninhydrin reagent is reported.
Abstract: A new method for monitoring the terminal stages of proteolysis in cheese, i.e. the formation of free amino acids, using the Cd-ninhydrin reagent is reported. The assay was very specific for free amino acids and may be performed on citrate-soluble, water-soluble or phosphotungstic acid-soluble fractions of cheese, but not on trichloroacetic acid-soluble extracts; water-soluble extracts were chosen for routine analysis. Application of the assay to several experimental cheeses showed almost linear increases in free amino acids during ripening for up to 12 months with a slightly faster rate of formation during the later stages of ripening.
260 citations
TL;DR: With the emergence of a more health-conscious society, the role of probiotic bacteria in human health has gained considerable attention from both the consumer and the producer.
Abstract: With the emergence of a more health-conscious society, the role of probiotic bacteria in human health has gained considerable attention from both the consumer and the producer. Considerable controversy has been associated with the lack of scientific evidence for the probiotic concept. However, current scientifically based research efforts worldwide are now focusing on the development of high-quality probiotic products containing microorganisms preselected for specific probiotic characteristics.
210 citations
TL;DR: This article showed that α-tocopherol supplementation significantly increased the oxidative stability of muscle from pigs fed both the tallow and soya oil diets compared to pigs fed the traditional tallow diet.
173 citations
TL;DR: Plasmin (EC 3.4.21.7) was added to Cheddar cheese milk to assess its contribution to cheddar cheese ripening; the activity of plasmin in the cheese was increased by levels ranging from 1·5 to 6 times that in the control cheeses as mentioned in this paper.
Abstract: Plasmin (EC 3.4.21.7) was added to cheese milk to assess its contribution to Cheddar cheese ripening; the activity of plasmin in the cheese was increased by levels ranging from 1·5 to 6 times that in the control cheeses. Even at the highest level of added plasmin, no activity was found in the whey. β-Casein was degraded faster in the experimental cheeses than in the controls, and the concentration of γ-caseins increased concomitantly. The total N in the water-soluble extract was up to ˜ 20% higher in the experimental than in the control cheeses but phosphotungstic acid-soluble N was not affected by the plasmin activity in the cheese. Several differences were apparent in the gel electropherograms of the water-soluble extracts of the experimental and control cheeses; some peptides were present at higher concentrations in the former, others in the latter, suggesting that plasmin contributes to both the formation and degradation of water-soluble peptides in cheese. The organoleptic quality of the plasmin-enriched cheeses was judged superior to that of the controls and ripening was considerably accelerated; a plasmin level 3–4 times the indigenous value appeared to be optimal. No bitterness was detected in any of the cheeses.
111 citations
TL;DR: The nutritional roles, requirements, and metabolism and the quantitative relationship between dietary intakes and health for a number of the minerals and trace elements have been more clearly defined in recent years, but there are still considerable deficiencies in understanding of these issues.
Abstract: The nutritional roles, requirements, and metabolism and the quantitative relationship between dietary intakes and health for a number of the minerals and trace elements have been more clearly defined in recent years, but there are still considerable deficiencies in our understanding of these issues, e.g., the significance of calcium in the etiology and treatment of osteoporosis and hypertension. Reliable information is now available on the content, and the principal factors affecting it, of most of the minerals and trace elements in human and cow's milks. However, for some of the trace elements, there is still a wide variation in reported values in the literature, which is due, at least in part, to analytical difficulties. The contribution of cow milk and milk products to the diet in Western countries is significant for sodium, potassium, chloride, calcium, phosphorus, zinc, and iodine. Iodine is the only trace element for which there has been any suggestion of excessive amounts in cow milk. However, there is evidence of a decline in milk iodine concentrations in the United States in recent years, although the situation in other countries less clear. Breast milk usually has adequate mineral and trace element contents for feeding full-term infants, with the exceptions of fluoride, for which supplementation of infants is recommended, and of selenium in some countries, such as Finland and New Zealand, where maternal intakes are low. However, breast milk selenium contents have increased in these countries in recent years due to increased maternal selenium intakes. The concentrations of minerals and trace elements in infant formulas for full-term infants are generally higher than in human milk, and all appear to be more than adequate, with the possible exception of selenium, which may need to be increased in some formulas. Considerable changes in the mineral and trace element contents of formulas have been instituted in recent years in the light of improved knowledge of infant requirements. While the chemical forms of the macrominerals and some of the trace elements (iron, zinc, copper, and manganese) in milks are fairly well defined, the forms of many of the trace elements are unknown. Sodium, potassium, chloride, and iodine are believed to be almost totally absorbed from milks and infant formulas.(ABSTRACT TRUNCATED AT 400 WORDS)
104 citations
TL;DR: Study of transitional zone development defines morphologically the growth, relative movement and interaction of central and peripheral nervous tissues as they establish their mutually exclusive territories on either side of the CNS-PNS boundary, and helps to explain the wide variations in the form of the mature transitional zone.
101 citations
TL;DR: Production of the substance was pH-dependent and maximum yields were obtained in MRS broth cultures maintained at pH 5.5, and it was bactericidal in its mode of action against indicator cells of Lact.
Abstract: Lactobacillus helveticus 1829 produced an antimicrobial agent, designated helveticin V-1829, that demonstrated antagonistic activity against closely-related species. The agent was excreted into MRS agar, and was present in the supernatant fluids from both overnight broth and clotted milk cultures. It was heat labile (inactivated by 50 degrees C for 30 min) and was stable over the pH range 2.5 to 6.5. Production of the substance was pH-dependent and maximum yields were obtained in MRS broth cultures maintained at pH 5.5. Helveticin V-1829 was partially purified following growth of the producing strain in a semi-defined MRS medium and precipitating the cell-free filtrate with ammonium sulphate to 30% saturation. The cleared supernatant fluid was then brought to 60% saturation and the resulting precipitate pelleted and dialysed in 0.3 mol/l phosphate buffer. The partially purified inhibitor was sensitive to several proteolytic enzymes, and it was bactericidal in its mode of action against indicator cells of Lact. helveticus 1844 and Lact. delbrueckii subsp. bulgaricus 1489, indicating that it was a bacteriocin. A DNA probe specific for the helveticin J structural gene failed to hybridize to total genomic DNA of Lact. helveticus 1829, indicating that helveticin V-1829 is not significantly related to helveticin J.
90 citations
TL;DR: Four lipophilic sulphur and/or nitrogen containing calixarene derivatives have been tested as ionophores in Ag(I)-selective poly (vinyl chloride) membrane electrodes, giving acceptable linear responses and high selectivity towards other transition metals and sodium and potassium ions.
TL;DR: In this paper, the authors examine, from a cultural perspective, owner-managers' and other stakeholders'interpretations of the partial fusion of ownership and control through high leverage in eight UK management buy-outs (MBOs).
Abstract: This study examines, from a cultural perspective, owner-managers’and other stakeholders’interpretations of the partial fusion of ownership and control through high leverage in eight UK management buy-outs (MBOs). Owner-control and debt-control are interpreted as having positive effects on managerial motivation, organizational decision-making processes and implementation of cost reduction strategies and negative ones on fundamental changes in strategy and acquisition. These interpretations accord broadly with agency theory propositions but show that owner-managers place less emphasis on wealth incentive effects and more emphasis on the enabling and facilitating roles of collective ownership and the freedom it gives from inappropriate corporate control.
01 Jan 1992
TL;DR: In this article, the materials and the fabrication of planar magnetic components for switch mode power supplies (SMPSs) and other applications are reviewed and the advantages and disadvantages of such devices are introduced.
Abstract: The materials and the fabrication of planar magnetic components for switch mode power supplies (SMPSs) and other applications are reviewed. The advantages and the disadvantages of such devices are introduced. The magnetic materials used in the devices, such as ferrite, amorphous metallic glass, and thin and thick magnetic films, are detailed. The devices have varying degrees of planarization-partially planar devices with magnetic cores and planar windings and truly planar devices for integrated magnetic circuits with planar windings and planar magnetics. Devices of both types reported in the literature since 1979 are reviewed. The design of the planar magnetic components must be optimized with respect to losses, and design issues which relate to electrical, thermal, and mechanical performance are discussed. >
TL;DR: In this paper, a simple, fully symmetrical, current-controlled CMOS oscillator is presented, which uses two grounded capacitors, and operates with power supply voltages as low as 3 V.
Abstract: A simple, fully symmetrical, current-controlled CMOS oscillator is presented. The oscillator uses two grounded capacitors. This 5-V architecture permits relatively large capacitor voltage amplitudes, thus minimizing jitter. The design also operates with power supply voltages as low as 3 V. Because there are no special capacitor requirements, the design is compatible with standard scaled digital CMOS processes. The use of a double differential latching comparator allows high-speed operation with good control linearity. The circuit was successfully fabricated using a 1.2- mu m CMOS process. >
TL;DR: It is suggested that damage to the innervation of the internal anal sphincter during rectal mobilization and further direct injury to the spharker during transanal instrumentation both contribute to the fall in anal resting pressure observed following low anterior resection.
Abstract: It has been postulated that reduction in anal resting pressure following low anterior resection is due to intraoperative injury to the internal anal sphincter during transanal passage of the stapling device or damage to its nerve supply in the course of rectal mobilization The aim of this study was to assess the relative importance of either mechanism Fourteen dogs had a standard segment of colon and distal rectum excised Colorectal reconstruction was performed using either a low stapled EEA® (US Surgical Corporation, Norwalk, CT) colorectal anastomosis (n=7) or a handsewn anastomosis (n=7) Anorectal manometry was performed preoperatively and again on the 10th postoperative day Resting anal pressure was significantly reduced after EEA® anastomosis (mean±SEM: before, 49±3 mm Hg; after, 20±4 mm Hg; P <0001) and handsewn anastomosis (mean±SEM: before, 46±4 mm Hg; after, 35±4 mm Hg; P<001) Postoperative resting pressures were also significantly reduced (P<005) following EEA® anastomosis when compared with the handsewn group This study suggests that damage to the innervation of the internal anal sphincter during rectal mobilization and further direct injury to the sphincter during transanal instrumentation both contribute to the fall in anal resting pressure observed following low anterior resection
TL;DR: In this article, voltammograms were recorded for gold in different strong acids both in the absence and presence of various oxidants and reductants, and two incipient hydrous oxide species were assumed to be involved: a cationic Au(I) species that is stable to quite low potentials; the reversible potential for formation of this species is too low to be of interest in most electrocatalytic reactions in acid.
TL;DR: In this paper, it was shown that gold in aqueous media exhibits significant electrocatalytic activity in base, an effect that has been attributed to a phenomenon known as pre-monolayer oxidation.
TL;DR: Magnesium chloride was the most successful agent, inducing anaesthesia quickly, allowing rapid recovery with minimal stress and mortality of live oysters.
TL;DR: In this article, the authors measured the silicon island temperature in both long and submicrometer thin-film MOSFETs as a function of bias conditions using noise thermometry.
Abstract: The authors report the direct measurement of the silicon island temperature in both long and submicrometer thin-film silicon-on-insulator (SOI) MOSFETs as a function of bias conditions using noise thermometry. They show that the device island temperature increases with drain voltage and that this results in a reduction of drain current. Using standard models of the drain current and velocity/field expression, they show that a thermally induced fall in mobility quantitatively accounts for the loss in drain current drive observed. >
TL;DR: In this paper, a survey of the electrocatalytic behaviour of gold, both for oxidation and reduction processes, mainly with regard to aqueous solutions of low pH, was carried out.
Journal Article•
TL;DR: A similar situation was found between seizure control and social status, with poor seizure control occurring in patients in social group six and patients with lower educational attainments being significantly more likely to havepoor seizure control, or required polypharmacy.
Abstract: Employment, marital, educational and social status in epileptic patients attending a seizure clinic were assessed. A total of 343 patients were evaluated. The social group, employment and marital status did not compare favourably with the overall population. Forty per cent of patients belonged to social group five and six compared with 14% of the population. Thirty three per cent of male patients aged 20 years or more were married, compared with 65% in the community. The corresponding statistics for females were 46% and 73% respectively. The male unemployment rate of 34% compared poorly with the unemployment rate of 13% for the period during which the study data was collected. Patients with lower educational attainments were significantly more likely to have poor seizure control (P less than 0.001), or required polypharmacy. A similar situation was found between seizure control and social status, with poor seizure control occurring in patients in social group six.
TL;DR: In the upper part of the Burrishoole system, anadromous trout do not appear to comprise a separate population from non-migratory trout and interbreeding may occur, but in the lower part of this system, this appears to be the case.
Abstract: Ten polymorphic enzyme coding loci were assayed using starch gel electrophoresis in anadromous (sea trout) and freshwater-resident trout, Salmo trutta, from two neighbouring river systems draining into Clew Bay in western Ireland. Samples were collected from the Burrishoole and from the neighbouring Newport river system. In the Burrishoole system, two samples were from above waterfalls impassable to migratory trout, two consisted of anadromous smolts or post-smolts and the remainder were freshwater-resident trout from freely accessible areas. There were large differences in gene frequency between trout from above impassable barriers and all others sampled, and these two groups also differed substantially from each other. More minor differences were evident between some other samples, particularly between trout from the upper lake and streams entering it and a stream associated with the lower lake. Two anadromous populations therefore occur in the Burrishoole system. In contrast, no differences were evident in two sampling years between anadromous trout and cohabiting freshwater-resident trout from the upper part of the Burrishoole system. Thus, in the upper part of this system, anadromous trout do not appear to comprise a separate population from non-migratory trout and interbreeding may occur.
TL;DR: At Lough Hyne Marine Nature Reserve, western Cork, Ireland, the intertidal barnacles Chthamalus stellatus (Poli) and C. montagui Southward were shown to be capable of breeding in their first year after settlement.
TL;DR: The enhanced model (NMOD) exhibits smooth and continuous transitions in the weak to strong inversion region, and in the region between linear and saturation modes of device operation, which improve both the model's current and conductance prediction accuracy, as well as its convergence properties when used in circuit simulation.
Abstract: A MOSFET model optimized for analog circuit simulation is presented and shown to agree with measured device characteristics, especially device output conductance and transconductance, over a wide range of operation. The widely used SPICE Level 3 (MOS3) model equations were utilized as a starting point in the model development process. The enhanced model (NMOD) exhibits smooth and continuous transitions in the weak to strong inversion region, and in the region between linear and saturation modes of device operation. These smooth transitions improve both the model's current and conductance prediction accuracy, as well as its convergence properties when used in circuit simulation. This is made possible because a single current equation is utilized for all regions of device operation. The NMOD model accurately characterizes devices over a wide range of geometries, achieving, for example, 1.3% and 4.2% average errors between measured and model I/sub DS/ and gds characteristics, respectively, for a 20/1.3- mu m p-channel device over a 5-V bias range. >
TL;DR: In this article, three inscribed sheaths for small angle-backed weapons are discussed in detail, and compared with other contemporary sheaths, and a list of known examples is given.
Abstract: THREE ANGLO-SAXON inscribed sheaths are discussed in detail, and compared with other contemporary sheaths for small angle-backed weapons. An appendix lists all known examples.
TL;DR: Proteolysis and flavor development in Cheddar cheese made with single starter strains, Lactococcus lactis ssp. lactis UC317 or LC cremoris HP, were evaluated over a 12-mo ripening as discussed by the authors.
TL;DR: The prevalence of enamel fluorosis/defects was similar in children living in fluoridated and non-fluoridated areas but the prevalence of diffuse opacities (DDE) was higher in the fluoridated areas.
Abstract: Water fluoridation was introduced in Ireland in 1964 and in recent years the availability of fluoride from other sources had increased. As part of a National Survey of Children's Health in Ireland Dean's and the DDE indices were used to determine the prevalence of enamel fluorosis/defects in 8- and 15-yr-old children in fluoridated and non-fluoridated areas. Over 94% of the children examined in all areas were regarded as having normal enamel, as defined by Dean's index, the remainder showing evidence of either questionable, very mild or mild fluorosis. Between 52% and 63% of the children had one or more teeth affected by enamel defects when measured by the DDE index. The prevalence of enamel fluorosis/defects was similar in children living in fluoridated and non-fluoridated areas but the prevalence of diffuse opacities (DDE) was higher in the fluoridated areas.
01 Dec 1992
TL;DR: In this paper, a two-dimensional device simulator which allows the complete transient simulation of nonvolatile memories is presented, derived from HFIELDS and incorporating models to account for Fowler-Nordheim tunneling, hot electron injection through silicon dioxide, and band-to-band tunneling in silicon.
Abstract: A two-dimensional device simulator which allows the complete transient simulation of nonvolatile memories is presented. The simulator has been derived from HFIELDS and incorporates models to account for Fowler-Nordheim tunneling, hot electron injection through silicon dioxide, and band-to-band tunneling in silicon. The physical models have been verified by comparing simulations with measurements performed on suitable test structures where good agreement has been obtained. The tool has been used to investigate flash EEPROM device scaling and to evaluate a published scaling scenario. >