Showing papers by "University College Cork published in 1991"
TL;DR: In this article, the influence of three levels of vitamin E in the diet of pigs on the subcellular deposition of α-tocopherol in the muscle and on selected quality characteristics of pork meat (oxidative stability of lipids, colour, drip loss, microbial growth) was studied.
Abstract: The influence of three levels of vitamin E in the diet of pigs on the subcellular deposition of α-tocopherol in the muscle and on selected quality characteristics of pork meat (oxidative stability of lipids, colour, drip loss, microbial growth) was studied.
The content of α-tocopherol in adipose tissue and L. dorsi muscle as well as in mitochondrial and microsomal fractions of the muscle significantly increased (P < 0.05) with increasing levels of dietary vitamin E. The differences in the concentrations of α-tocopherol in the subcellular fractions were evident in the enhanced stability of the membranes when exposed to metmyoglobin/hydrogen peroxide.
The beneficial effect of dietary vitamin E on the oxidative stability of pork lipids during the storage of pork chops and ground pork was also demonstrated. Even though lipid oxidation increased in all cases during storage, the pork products from the pigs receiving the highest level of vitamin E (200 IU kg−1 feed) exhibited the smallest increase in thiobarbituric acid reactive substances. In addition, increased colour stability and decreased drip loss were observed on keeping pork chops, which had been previously frozen for three months, at 4°C under fluoresent light for 10 days. The possible effect of α-tocopherol on membrane fluidity in this context is discussed.
255 citations
TL;DR: When 100% inspection in the order of production is in progress, an alternative approach to the p-chart or the Poisson-based CUSUM chart is to monitor the lengths of runs of conforming items between successive nonconforming items.
Abstract: When 100% inspection in the order of production is in progress, an alternative approach to the p-chart or the Poisson-based CUSUM chart is to monitor the lengths of runs of conforming items between successive nonconforming items. Two Shewhart-type chart..
244 citations
TL;DR: Blood pressure was higher at the onset of menstruation than at most other phases of the cycle, and changes in plasma 17 beta-oestradiol and progesterone concentrations were also similar in the two groups.
Abstract: 1. Changes in blood pressure during the normal menstrual cycle are not well documented, and previous studies have given conflicting results. 2. Thirty normotensive women and ten mildly hypertensive women measured their blood pressure at home each morning for 6 weeks, under standardized conditions, using a UA-751 semi-automatic sphygmomanometer. All had normal menstrual cycles and subjects entered the study at different phases of the cycle. 3. Blood pressure was higher at the onset of menstruation than at most other phases of the cycle (systolic blood pressure, P less than 0.05; diastolic blood pressure, P less than 0.001). Adjusted diastolic blood pressure was higher in the follicular than in the luteal phase (mean difference 1.23 mmHg, P less than 0.001). Similarly, blood pressure was lower during days 17-26 than during the remainder of the cycle (adjusted mean difference in systolic blood pressure -0.65 mmHg, P = 0.07; adjusted mean difference in diastolic blood pressure -1.19 mmHg, P less than 0.001). 4. Similar patterns were seen in normotensive and hypertensive subjects, and changes in plasma 17 beta-oestradiol and progesterone concentrations were also similar in the two groups.
110 citations
TL;DR: A relatively mature area of atomic spectrometry, hence there are fewer new developments than in other research fields, is surveyed in this article, where a plethora of methods have been developed for the preconcentration and separation of analyte and matrix prior to sample introduction.
Abstract: This review covers a relatively mature area of atomic spectrometry, hence there are fewer new developments than in other research fields. The review should be read in conjunction with the previous year’s review and with other related reviews in the series. Over the last several years the research emphasis has shifted from novel developments to more routine applications. A plethora of methods have been developed for the preconcentration and separation of analyte and matrix prior to sample introduction. Some novel fundamental studies of plasmas have been published, and new research in the area of laser induced breakdown spectroscopy is still appearing, perhaps reflecting the status of a technique which is always on the verge of “arriving” in the mainstream. The flurry of activity generated by the widespread commercialisation of simultaneous solid-state atomic emission detectors has diminished, particularly for chemometrics and transient signal analysis. The only other major area of novelty is that of speciation analysis using coupled techniques, and even this has moved towards more routine applications.
101 citations
TL;DR: In this article, the effects of antioxidants on stability of lipids in restructured chicken nuggets were investigated by a modified thiobarbituric acid (TBA) test, sensory evaluation and chromatographic analysis.
Abstract: Effects of antioxidants on stability of lipids in restructured chicken nuggets were investigated. Lipid oxidation during refrigerated and frozen storage was monitored by a modified thiobarbituric acid (TBA) test, sensory evaluation and chromatographic analysis. TBA-reactive substances (TBARS) values and sensory scores demonstrated that STPP/ OR was comparable to STPP/TBHQ in protecting refrigerated and frozen chicken nuggets. STPP or OR alone was less effective than OR/STPP combinations in both studies. STPP/OR and STPP/TBHQ also effectively retarded oxidative degradation of polyunsaturated fatty acids in chicken nuggets during frozen storage. No apparent beneficial effects on oxidative stability of the chicken nuggets were observed by adding OR to the frying oil.
99 citations
TL;DR: An examination of recent behavioral research into the relationship between stimulus equivalence phenomena and symbolic behavior, and language more generally is examined.
Abstract: The current paper represents an attempt to clarify the nature of the radical behaviorist’s perspective on human cognition. This attempt will involve an examination of recent behavioral research into the relationship between stimulus equivalence phenomena and symbolic behavior, and language more generally. This form of behavior analysis is offered as an alternative to, but not a replacement for, other methodological and conceptual approaches to psychology.
96 citations
94 citations
TL;DR: In this paper, the authors evaluated the antioxidant properties of raw restructured beef steaks stored at −20°C for six months and in cooked steaks at 4°C six days.
Abstract: Antioxidant activities were evaluated in raw restructured beef steaks stored at −20°C six months and in cooked steaks at 4°C six days. During refrigerated storage, thiobarbituric acid-reactive substances (TBARS) and sensory scores indicated sodium tripolyphosphate (STPP) provided (p<0.01) protection against warmed-over flavor development. No significant differences existed between OR (0.10%)/STPP and TBHQ/STPP, due probably to STPP. During frozen storage, a linear concentration effect of OR existed (p<0.01) for both TBARS values and sensory scores indicating OR was an effective antioxidant which combined with STPP produced an additive protective effect during frozen storage. Hexanal content and phospholipid fatty acid profiles also changed during frozen storage. Correlation coefficients between TBARS values and sensory scores were generally nonsignificant.
87 citations
TL;DR: The findings show that while there was a wide range in the dose required to achieve normal serum 25-hydroxyvitamin D levels--between 400 and 4000IU/day--78 per cent of patients responded to a dose of 2400 IU/day.
Abstract: The dose of vitamin D3 required to maintain normal serum 25-hydroxyvitamin D levels in epileptic patients was evaluated in a prospective study. Patients were divided into two groups, comprising 14 institutionalized and 18 non-institutionalized subjects; they were taking carbamazepine, phenytoin and phenobarbitone, alone or in combination. The study was divided into a dose titration stage and a further period of assessment on a fixed dose after attainment of normal serum 25-hydroxyvitamin D levels. Seventeen of the 18 non-institutionalized patients achieved normal levels over a period of 12 months; the remaining patient became normal after 15 months. The dose required to achieve normal levels ranged from 400 to 4000 IU/day; three patients required less than 2400 IU vitamin D3, 12 required 2400 IU and three required greater than 2400 IU. All institutionalized patients achieved normal levels over a period of 12 months; six patients required less than 2400 IU, six required 2400 IU and two required greater than 2400 IU vitamin D3. Raised alkaline phosphatase levels occurred in 11 patients, and reverted to normal in six patients during the initial return of 25-hydroxyvitamin D levels to normal. During the second 12 months, when patients were taking a fixed dose of vitamin D3, alkaline phosphatase increased in five patients who had achieved normal levels. During this phase normal 25-hydroxyvitamin D levels were not maintained in five patients. There was a significant seasonal variation of 25-hydroxyvitamin D levels institutionalized patients, being highest in June and lowest in December. Our findings show that while there was a wide range in the dose required to achieve normal serum 25-hydroxyvitamin D levels--between 400 and 4000 IU/day--78 per cent of patients responded to a dose of 2400 IU/day.
86 citations
TL;DR: In this article, the authors discuss the relative contributions of enzymes in the ripening of various types of cheese and pay attention to secondary reactions like amine formation and the action of lipases during cheese ripening.
Abstract: Summary Enzymes either from milk itself or added in the form of rennet or microorganisms play the dominant role in the conversion of milk in cheese. Of the enzymic reactions the breakdown of caseins is by far the most important reaction. Five main systems contribute to the hydrolysis of caseins: Rennet, indigenous milk proteinase, proteinases and peptidases produced by the starter cultures, enzymes of the secondary starters, enzymes of non‐starter cultures. The relative contributions of these systems in the ripening of various types of cheese will be discussed in detail. Some attention will be paid to secondary reactions like amine formation and the action of lipases during cheese ripening.
79 citations
TL;DR: Plasma α‐tocopherol concentration appears to be a good index of α‐tropopherol status of lung, liver and heart, and in all cases the relationship between the concentrations of dietary and tissue α‐ocopherol was highly significant.
Abstract: 1. The effect of feeding α‐tocopherol (5 to 180 μg/g diet) for 24 days on the concentrations of α‐tocopherol in various chicken tissues was investigated. 2. Tissue α‐tocopherol concentrations responded to dietary intake in the order: heart =; lung > liver > thigh muscle > brain, and in all cases the relationship between the concentrations of dietary and tissue α‐tocopherol was highly significant (0.997 ≤ r ≤ 1). 3. Plasma α‐tocopherol concentration appears to be a good index (r ≥ 0.910, P< 0.001) of α‐tocopherol status of lung, liver and heart.
TL;DR: The growth curves of pigs fed the higher levels of vitamin E tended to become parallel to that of the control group (10 IU vitamin E kg−1 feed), suggesting that the advantage gained in body weight in the early growth period actually persisted in subsequent phases.
Abstract: The effects of supranutritional vitamin E supplementation in the diet on the growth performance of pigs, the deposition of α-tocopherol in different tissues and the activity of certain blood enzymes were investigated. Pigs receiving diets supplemented with 100 and 200 IU vitamin E kg−1 feed exhibited significant improvement in daily body gain and feed conversion efficiency in the early growth phase (P < 0.05). With advance in age. the growth curves of pigs fed the higher levels of vitamin E tended to become parallel to that of the control group (10 IU vitamin E kg−1 feed), suggesting that the advantage gained in body weight in the early growth period actually persisted in subsequent phases.
The concentrations of α-tocopherol in blood plasma and different tissues (heart, kidney, lung and liver) significantly increased (P<0.05) with increasing levels of dietary vitamin E. However, the activity of lactate dehydrogenase, creatine kinase and aspartate aminotransferase in blood plasma was not influenced by the levels of vitamin E supplementation.
TL;DR: The electrophoretic studies demonstrated that proteolysis of the heavy myosin chain, α-actinin and actin was most prominent and the increased insolubility of meat proteins was confirmed by SDS-PAGE.
TL;DR: Clinical improvement and histological evidence of remission associated with use of heparin in three patients with ulcerative colitis are reported.
TL;DR: Results indicate that the pCI305 replication region differs markedly from most gram-positive replicons examined to date, and the absence of a detectable single-stranded DNA intermediate during replication is indicated.
TL;DR: It is proven that critical sequences contain trapped surfaces for large values of the argument, and by a theorem due to Penrose, the spacetimes evolving from all such configurations must develop singularities.
Abstract: Sequences of nonsingular, asymptotically flat initial data for general relativity (GR) in vacuo, called critical sequences, are defined which approach the strong-field limit of GR in a precise sense. It is proven that critical sequences contain trapped surfaces for large values of the argument. Thus, by a theorem due to Penrose, the spacetimes evolving from all such configurations must develop singularities. In the course of the proof a new and conceptually simple proof of the positivity of the Arnowitt-Deser-Misner mass in the strong-field regime is obtained.
28 Oct 1991
TL;DR: In this paper, the shape of the static torque-angle-current characteristics of a switched reluctance motor drive can be fully determined by a series of measurements performed with the drive in a self-learning mode, without the need for an external loading device.
Abstract: The nonlinear torque-production mechanisms in the doubly salient, switched reluctance motor drive are both current and position dependent. It is shown that the shape of the static torque-angle-current characteristics of this drive can be fully determined by a series of measurements performed with the drive in a self-learning mode, without the need for an external loading device. These measurements consist of static tests, in which the torques produced by currents in different phases are balanced, and dynamic measurements, in which the relative currents required to produce the same torque at different positions are ascertained. The controller can then achieve very smooth low-speed performance by determining the current required to obtain the optimum torque contribution from each phase, at each rotor position. >
TL;DR: In this article, surface activities at the air/water interface and emulsifying properties of highly dispersed sodium, ammonium and low calcium caseinates, and highly aggregated high calcium caseinate and ethanol-precipitated and micellar caseins, were determined.
TL;DR: In this paper, the accuracy of room temperature adsorption of benzyl alcohol onto TiO2 (P25) from acetonitrile and aqueous solutions was reported.
Abstract: Tests are reported of the accuracy with which room temperature adsorption of benzyl alcohol onto TiO2 (P25) from acetonitrile and aqueous solutions can be fitted to a Langmuir-type adsorption isotherm modelled by competitive adsorption—desorption of solute and solvent in a monomolecular mixed-solution layer at the TiO2 surface. Better agreement, and a considerably larger adsorption equilibrium constant Kads, is shown for the acetonitrile suspensions. Initial rates of TiO2-sensitized photo-oxidation of benzyl alcohol to benzaldehyde have also been compared. These too are larger for the acetonitrile solutions and their concentration dependence shows better agreement with predictions arrived at by combining Kads values from adsorption studies with k′LH values deduced from Langmuir—Hinshelwood-type analysis of TiO2-sensitized photodehydrogenation rates. Possible reasons for the failure of data from the aqueous suspensions to give comparable agreement with such predictions are considered. However, kinetic tests of these possibilities are shown not to a differentiate unequivocally between mechanisms which would restrict reaction events to the monomolecular surface layer and others which would allow photogenerated species to escape from that layer and react in the aqueous solution.
TL;DR: The effect of gate oxide growth conditions on the sensitivity of the NMRC's PMOS RADFET, which has a 400-nm dry/wet/dry gate oxide is investigated in this paper.
Abstract: The effect of gate oxide growth conditions on the sensitivity of the NMRC's PMOS RADFET, which has a 400-nm dry/wet/dry gate oxide is investigated. The necessity for such an evaluation arose because the PMOS RADFET standard gate oxide consists of a dry/wet/dry 400-nm oxide, and published data for the effects of processing conditions on gate oxides are mainly for either wet or dry oxides with a thickness in the more conventional gate oxide range of 20 nm-100 nm. It is clearly shown that, for any given RADFET gate oxide, an optimum set of processing conditions exists to maximize the RADFET's radiation sensitivity. A by-product of the evaluation of the processing conditions is that it is possible to set up a sensitivity-oxide thickness curve at the optimum processing conditions. >
TL;DR: Detailed information about the growth characteristics, ecology, virulence mechanisms and clinical aspects of L. monocytogenes is now available, which enables more effective control of the transmission of the pathogen via foods.
Abstract: Transmission, via foods, of Listeria monocytogenes, the causative agent of listeriosis, has become of major concern in recent years. Although the pathogen has been associated with human disease since 1929 (Ref. 1), it was not until recently that foodborne transmission of listeriosis to humans was conclusively demonstrated. In its most severe form, listeriosis can be a life-threatening infection; in some cases, it can cause severe complications in pregnancy, leading to spontaneous abortion. The severity of the symptoms and the high mortality rates (∼30%) associated with recent outbreaks of listeriosis have led to widespread public concern, and have increased efforts to prevent further cases. Detailed information about the growth characteristics, ecology, virulence mechanisms and clinical aspects of L. monocytogenes is now available. Such information enables more effective control of the transmission of L. monocytogenes via foods.
TL;DR: Levels of population differentiation were comparable to those found in other regions throughout the range of the species, and temporal stability in gene frequencies was apparent when the results were compared with previously published data.
Abstract: The extent of genetic variation in wild Atlantic salmon parr, Sulmo salur L., from river systems in Ireland, Iceland and eastern Canada, was investigated using starch gel electrophoresis. Within Ireland, seven polymorphic enzyme loci (sAAT-4*, GPI-1*, IDDH-1*, IDDH-2*, IDHP-3*, MDH-3* and mMEP-2*) were screened in nine different rivers and nine tributaries from the River Blackwater. Significant heterogeneity in gene frequencies occurred between riverine samples and between samples from tributaries of the River Blackwater. Variation between tributaries was as great as between rivers elsewhere in the country. Levels of population differentiation were comparable to those found in other regions throughout the range of the species, and temporal stability in gene frequencies was apparent when the results were compared with previously published data. Screening of riverine samples from Iceland and eastern Canada (Newfoundland and New Brunswick) allowed the Irish results to be considered in a broader context. Irish salmon cluster in the western European group, to which may be added Icelandic populations. Salmon from eastern Canada show a high level of genetic distinctiveness from the European group.
TL;DR: The genetic determinant for abortive infection of bacteriophage (Abi) from the lactococcal plasmid pCI829 was cloned on a 6.2 kb StuI fragment in Escherichia coli using the shuttle vector pSA3 and revealed similarity to consensus E. coli and Bacillus subtilis transcription/translation signals.
Abstract: The genetic determinant for abortive infection of bacteriophage (Abi) from the lactococcal plasmid pCI829 was cloned on a 6.2 kb StuI fragment in Escherichia coli using the shuttle vector pSA3. In Lactococcus lactis subsp. lactis MG1363Sm the resulting recombinant plasmid pCI816 conferred complete insensitivity to the small isometric-headed phage 712 and a reduced plaque size in the case of the prolate-headed phage c2. The determinant was further localized by subcloning and nuclease Bal31 deletion analysis; approximately 2.0 kb of DNA was essential for the expression of the Abi+ phenotype. Nucleotide sequence analysis of this region revealed a putative open reading frame of 1887 base pairs preceded by a putative promotor sequence and ribosome-binding site which exhibited similarity to consensus E. coli and Bacillus subtilis transcription/translation signals. Hybridization experiments indicated that this region was not homologous to the abi determinant from the phenotypically similar lactococcal plasmid pCI750.
TL;DR: In this paper, a method for the fractionation of sodium caseinate into a β-casein-rich permeate and an α s κ- caseinrich retentate has been developed using ultrafiltration through 300 000 dalton cut-off membranes at 4°C.
TL;DR: Five reared lines of Atlantic salmon, Salmo salar L., constituted over 90% of the smolt production of the Irish farming industry in 1990 and were assayed for the six polymorphic enzyme loci, which contribute most of the reported electrophoretically-detectable variation in the enzymes of S. salar.
TL;DR: In the absence of added NaCl, electrostatic repulsion prevented thermal gelation of β-lactoglobulin, pH 8.0, but added propylene glycol or urea supported weak gel structure formation.
Abstract: In the absence of added NaCl, electrostatic repulsion prevented thermal gelation of β-lactoglobulin, pH 8.0, but added propylene glycol or urea supported weak gel structure formation. When the electrostatic barrier was reduced by added NaCl, gelation occurred and gel strength was enhanced by propylene glycol addition and reduced by added urea, N-ethylmaleimide or merceptoethanol. Cohesiveness of β-lac-toglobulin gels containing NaCl decreased on adding propylene glycol, mercaptoethanol or N-ethylmaleimide but increased on adding urea. Relative to cohesiveness, elasticity/springiness was higher following N-ethylamleimide or mercaptoethanol addition but lower following urea addition. Molecular forces involved in gel structure formation and maintenance were proposed based on observed effects.
TL;DR: In this article, the 11B and 1H NMR chemical shifts of the known arsenaborane species [7-Me-nido-7-AsB10H12], 7-Me nido- 7-Asb10H11]−, [nido 7,8-As2B9H10]-−, and previously unreported metalladiarsenaboranes [3,3-(PPh3)2-3-(H)-closo-3,1,2-RhAs2b9H9] and [3
Abstract: The cluster 11B and 1H NMR chemical shifts of the known arsenaborane species [7-Me-nido-7-AsB10H12], [7-Me-nido-7-AsB10H11]−, [nido-7-AsB10H12]−, [closo-1,2-As2B10H10] and [nido-7,8-As2B9H10]−, of the known stibaborane species [closo-1,2-Sb2B10H10] and [closo-1,2-CSbB10H11], and of the previously unreported metalladiarsenaboranes [3,3-(PPh3)2-3-(H)-closo-3,1,2-RhAs2B9H9] and [3-(η5-C5Me5)-closo-3,1,2-RhAs2B9H9] were measured and assigned by [11B–11B]-COSY, [1H–1H]-COSY-{11B}, and 1H–{11B} NMR experiments. Similarities and trends in the cluster shielding patterns were examined in order to assess changes in supposed electronic structures.
TL;DR: A region of > 77 bases but < 131 upstream from the transcriptional start was found to be necessary for promoter activity, further suggesting that a transcriptional activator may be required for expression.
Abstract: An iron-regulated promoter was cloned on a 2.1 kb Bgl/II fragment from Pseudomonas sp. strain M114 and fused to the lacZ reporter gene. Iron-regulated lacZ expression from the resulting construct (pSP1) in strain M114 was mediated via the Fur-like repressor which also regulates siderophore production in this strain. A 390 by StuI-PstI internal fragment contained the necessary information for iron-regulated promoter expression. This fragment was sequenced and the initiation point for transcription was determined by primer extension analysis. The region directly upstream of the transcription start point contained no significant homology to known promoter consensus sequences. However the −16 to −25 by region contained homology to four other iron-regulated pseudomonad promoters. Deletion of bases downstream from the transcriptional start did not affect the iron-regulated expression of the promoter. The −37 and −43 by regions exhibited some homology to the 19 by Escherichia coli Fur-binding consensus sequence. When expressed in E. coli (via a cloned trans-acting factor from strain M114) lacZ expression from pSP1 was found to be regulated by iron. A region of > 77 bases but < 131 upstream from the transcriptional start was found to be necessary for promoter activity, further suggesting that a transcriptional activator may be required for expression.