Showing papers by "Cardiff University published in 1972"
TL;DR: Two conditions which tests of good discriminating power should satisfy are stated and proved and the probability of being able to discriminate between two blood samples using a battery of such tests is described.
Abstract: The paper shows how to calculate the probability of being able to discriminate between two blood samples using a single test. The distribution of the population with respect to this test criterion is assumed to be known. The paper goes on to describe how to calculate the probability of being able to discriminate between two blood samples using a battery of such tests. The tests are assumed to be independent. The actual calculations are made for a battery of seven such tests. Finally, two conditions which tests of good discriminating power should satisfy are stated and proved.
301 citations
TL;DR: In this paper, the pre-Arctic ocean concept is reviewed in the light of the Arctic Caledonides and named Iapetus, and it is shown that the ocean was in existence up to early Ordovician but had substantially closed by mid Ordovian times.
Abstract: Consideration of the arctic configuration of the Caledonides leads to a distinction between eastern and western geosynclinal belts. The western belt, comprising the East Greenland, East Svalbard and southern Barents Sea Caledonides is postulated to continue northwards into the Lomonosov Ridge, whilst the western Spitsbergen Caledonides are thought to have originated as part of the North Greenland geosyncline which is also thought to continue northwards to form the western part of the Lomonosov Ridge. The eastern Caledonian geosynclinal belt comprising the Scandinavian Caledonides appears to swing eastwards to link with the Timan Chain and possibly the Urals.The already postulated (‘Proto-Atlantic’) ocean concept is reviewed in the light of the Arctic Caledonides and named Iapetus. Faunal provincialism suggests that the ocean was in existence up to early Ordovician but had substantially closed by mid Ordovician times. Possible relics of the suture marking the closure of this ocean suggest that it lay to the west of the Arctic Scandinavian Caledonides trending NE to latitude 70° N and thence veered eastwards separating the southern Barents Sea Caledonides from those of Arctic Scandinavia, possibly connecting with the northern Uralian ocean. A previous branch of the ocean may have separated East Svalbard and East Greenland as an ocean-like trough. A further (pre-Arctic) ocean may have existed to the north of the North Greenland–Lomonosov Ridge geosynclines. This is named Pelagus.The closure of these oceanic areas and the deformation of the bordering geosynclines delineates three principal continental plates, namely, Baltic, Greenland and Barents Plates. Their relative dominantly E–W motion up to Silurian times produced compression between the Greenland and both the Baltic and Barents plates but dextral transpression and transcurrence between the latter plates. In Late Silurian to Devonian times an increasing northward component controlled late Caledonian transpression and sinistral transcurrence between the Greenland plate and the combined Baltic and Barents plates.
258 citations
TL;DR: The results support the validity of the reaction-rate data for carbon monoxide with oxyhaemoglobin of Roughton & Forster (1957) despite evidence to the contrary from other studies.
Abstract: 1. Measurements of transfer factor and sub-maximal exercise ventilation and cardiac frequency have been made on twenty women with iron-deficiency anaemia (Hb 8–9 g/100 ml) before and after ‘treatment’ with iron or placebo tablets and on control subjects.
2. The exercise ventilation, cardiac frequency and oxygen uptake were independent of haemoglobin concentration but the transfer factor was lower in the test than in control subjects and was increased by iron but not by placebo treatment. The results support the validity of the reaction-rate data for carbon monoxide with oxyhaemoglobin of Roughton & Forster (1957) despite evidence to the contrary from other studies.
3. In interpretation of sub-maximal exercise ventilation and cardiac frequency in iron-deficiency anaemia no allowance need be made for variation in haemoglobin concentration in the range 8–15 g/100 ml. For transfer factor a correction should be made by using a variant of the relationship of Roughton & Forster (1957).
247 citations
TL;DR: Tests on peripheral blood lymphocytes from twelve subjects with iron-deficiency anaemia revealed an impairment of lymphocyte transformation and migration inhibition factor production on stimulation with candida antigen and purified protein derivative, suggesting that iron deficiency may be a factor in the production or potentiation of immunodeficient states.
226 citations
TL;DR: This hypothesis is rejected in favour of the idea that the attached carbohydrate determines the extracellular fate of the protein molecule.
Abstract: It has been suggested that glycosylation is a means of labelling proteins for intracellular recognition and export. This hypothesis is rejected in favour of the idea that the attached carbohydrate determines the extracellular fate of the protein molecule.
202 citations
TL;DR: Two chemical parameters from lake water analyses are correlated with the species assemblage in individual lakes and trophic categories are defined on the quantitative chemical characteristics of lake waters, including range and limiting tolerance of solute content for many aquatic species.
Abstract: Summary
Species of submersed and floating-leaved aquatic macrophytes have been place in a series based on their patterns of occurrence in an ordination of floristic lists. Two chemical parameters from lake water analyses are correlated with the species assemblage in individual lakes and trophic categories are defined on the quantitative chemical characteristics of lake waters. The range and limiting tolerance of solute content for many aquatic species are described and related to these trophic categories. Restiction towards eutrophic conditions is considered as an obligate relatinship reflecting physiological demands. Some dystrophic and oligotrophic species are shown to have wide tolerance and are thought to be excluded from sites of higher trophic status by competition rather than physiological limitation.
200 citations
TL;DR: NAD and NADH were measured during growth: once more NADH was much more constant than NAD, and during change-over between aerobiosis and anaerobiosis, NADH showed a temporary increase but then returned to a constant level, whereas NAD changed from high aerobically to lowAnaerobically.
Abstract: Nicotinamide adenine dinucleotide (NAD) and reduced NAD (NADH) levels have been measured in bacterial cultures. The cofactors were assayed by using the very sensitive cycling assay described previously by Cartier. Control experiments showed that the level of total NAD(H) falls during harvesting, and so samples were taken quickly from growing cultures and extracted immediately without separating the cells from the medium. Total NAD(H) ranged from 4.0 to 11.7 mumoles/g of dry cells for three facultative organisms, Klebsiella aerogenes, Escherichia coli, and Staphylococcus albus. NADH was remarkably constant in these bacteria; only one out of ten series of determinations was outside the range 1.4 to 1.9 mumoles/g of dry cells. NAD(+) showed much greater variation. An anaerobe (Clostridium welchii) had significantly more total NAD(H) whereas an aerobe Pseudomonas aeruginosa had about as much NAD(H) as the facultative organisms. NAD and NADH were measured during growth: once more NADH was much more constant than NAD. During change-over between aerobiosis and anaerobiosis, NADH showed a temporary increase but then returned to a constant level, whereas NAD changed from high aerobically to low anaerobically. These results are discussed in terms of the control mechanisms that may be involved.
188 citations
TL;DR: Intracisternal injection of ethanolamine O-sulphate into rats led to rapid inactivation of 4-aminobutyrate aminotransferase in vivo.
Abstract: 1. Partially purified preparations of rat brain 4-aminobutyrate aminotransferase were inhibited in a time-dependent manner by ethanolamine O-sulphate. The inhibition was not reversed by dialysis. 2. The inhibitor formed an initial reversible complex with the enzyme (Ki=4.4×10−4m) and the rate of inactivation followed pseudo-first-order kinetics (k=7.15×10−4s−1). The inclusion of 4-aminobutyrate markedly slowed the rate of inactivation. 3. Ethanolamine O-sulphate did not inhibit glutamate decarboxylase, alanine aminotransferase or aspartate aminotransferase. 4. Intracisternal injection of ethanolamine O-sulphate into rats led to rapid inactivation of 4-aminobutyrate aminotransferase in vivo.
166 citations
TL;DR: The amount of the cross-linking amino acids desmosine and isodesmosine was lower in elastins isolated from both aorta and pulmonary tissues of senile subjects than those from younger subjects.
Abstract: 1 Elastins were isolated from the visceral pleuras and parenchymas of lungs of humans of different ages 2 The elastin content of pleuras increased whereas that of parenchymas remained constant with increasing age 3 The amino acid compositions and carbohydrate contents of elastins isolated from both pulmonary tissues changed in the same way with increasing age of the subjects These changes were similar to those observed in elastins isolated from the aorta 4 Similar glycoproteins were isolated from pleuras and aortas, and were more difficult to extract from the elastins of older subjects Contamination with these glycoproteins was responsible for the changes in composition of elastin, as the age of the tissue from which it was extracted increased 5 The amount of the cross-linking amino acids desmosine and isodesmosine was lower in elastins isolated from both aorta and pulmonary tissues of senile subjects than those from younger subjects
141 citations
TL;DR: In this article, the method of forming curved finite element shape functions from simple independent generalized strain functions is applied to a rectangular cylindrical shell element, which has 20 degrees of freedom and satisfies the conditions for rigid body displacements and constant strain (in so far as this is allowed by compatibility equations).
TL;DR: The lecithin concentration in the amniotic fluid seems to be a sensitive index of fetal lung maturity and of the potential risk of respiratory distress developing in the baby.
TL;DR: The multitude of seeds produced by an Agaric or a Boletus is innumerable; yet not one in ten thousand answers the purpose of propagation.
Abstract: The multitude of seeds produced by an Agaric or a Boletus is innumerable! It is astonishing! Yet not one in ten thousand answers the purpose of propagation. Is not the air we breathe charged with them all the declining part of the year ? Do we not receive them into our lungs with every breath we draw? Whence proceed the quinsies, coughs and other complaints which prevail in Autumn? JAMES BOLTON: An History of British Ferns (Huddersfield, 1790)
TL;DR: Evidence is presented that this deleterious effect became worse between the 4th and 5th years of age, and appears to be due to the presence of the bone.
TL;DR: When sodium 35S-sulphide is administered to rats either intraperitoneally, orally or intravenously it is oxidized primarily to inorganic 35S, which is eventually excreted in the urine.
TL;DR: It is found that when material to be matched is shared between the hemispheres, response latencies are reduced, suggesting increased capacity for the processing of such information and supporting the hypothesis that each hemisphere contains its own processing and analysing system.
Abstract: Two experiments are described in which, by a divided visual field technique, simple non-verbal stimulus material is directed to either the right hemisphere, left hemisphere, or divided between the hemispheres. It is found that when material to be matched is shared between the hemispheres, response latencies are reduced, suggesting increased capacity for the processing of such information and supporting the hypothesis that each hemisphere contains its own processing and analysing system. When the material is directed to only one hemisphere, and a bimanual motor response required, a relative superiority of the right hemisphere is found. If the response required is a vocal response, then further relative blocking of the processing undertaken by the left hemisphere is observed.
TL;DR: There is no significant difference between the results of the two forms of treatment in patients treated for varicose veins by routine surgery and injection/compression sclerotherapy.
TL;DR: Asbestos bodies extracted from human lungs have been examined under the electron microscope to determine their morphology and diffraction characteristics and were found to have a major crystalline component which is structurally similar to extracts of ferritin produced from animal and human organs.
TL;DR: The results indicated that O2 and not NO3- was initially important in determining the type (and total amount) of cytochromes present in anaerobic and aerobic cells, although there was some indication that NO2- andNO3- might be important in the control of cy tochromes concerned with nitrite reduction.
TL;DR: Conditions based on previous assays with potassium p-acetylphenyl sulphate have been established for the specific assay of arylsulphatase C in rat tissues and this enzyme has optimum activity with 40mm substrate at pH8.0 in the presence of 0.1m-phosphate buffer.
Abstract: Conditions based on previous assays with potassium p-acetylphenyl sulphate have been established for the specific assay of arylsulphatase C in rat tissues. The enzyme has optimum activity with 40mm substrate at pH8.0 in the presence of 0.1m-phosphate buffer. Under these conditions arylsulphatase C can be assayed without interference from the other arylsulphatase enzymes present and is useful as a marker for the endoplasmic reticulum in cell-fractionation studies.
TL;DR: In this article, rate equations with fluctuation operators describing the quantum nature of the transitions are solved for (i) the exponential band tails model of a semiconductor laser at 80 °K, and (ii) the parabolic bands with no k-selection model of an SIRL at room temperature.
Abstract: Rate equations with fluctuation operators describing the quantum nature of the transitions are solved for (i) the exponential band tails model of a semiconductor laser at 80 °K, and (ii) the parabolic bands with no k-selection model of a semiconductor laser at room temperature. The results show the same characteristic features as those of Haug [1]. Above threshold a sharp resonance in the noise spectrum is found in the GHz region, the resonance frequency increasing with current and temperature. Simple analytic expressions for this resonance frequency are given. The results indicate that the low-frequency part of the relative photon noise spectrum has its maximum value just below threshold, while that of the relative electron noise spectrum has its maximum value just above threshold. In addition, it would appear from these results that intensity fluctuations in the light output and junction current of room-temperature c.w. lasers are likely to be of less importance than those of c.w. lasers at liquid nitrogen temperature.
Es werden die Bilanzgleichungen mit Fluktuations-Operatoren, die die Quantennatur der Ubergange beschreiben, fur 1. das Modell eines Halbleiterlasers mit exponentiellem Bandauslaufer bei 80 °K und 2. das Modell eines Halbleiterlasers mit parabolischen Bandern ohne k-Auswahl fur Zimmertemperatur gelost. Die Ergebnisse zeigen dieselben charakteristischen Zuge wie die von Haug [1]. Oberhalb der Schwelle wird eine scharfe Resonanz im Rauschspektrum im GHz-Bereich gefunden, deren Resonanzfrequenz mit dem Strom und der Temperatur zunimmt. Es werden einfache analytische Ausdrucke fur diese Resonanzfrequenz angegeben. Die Ergebnisse zeigen, das der niederfrequente Anteil des relativen Photonen-Rauschspektrums seinen Maximalwert gerade unterhalb der Schwelle hat, wahrend der des relativen Elektronen-Rauschspektrums sein Maximum gerade oberhalb der Schwelle erreicht. Zusatzlich scheint aus diesen Ergebnissen zu folgen, das Intensitatsschwankungen der Lichtleistung und des Sperrschichtstromes fur kontinuierliche Zimmertemperatur-Laser weniger bedeutsam sind als diejenigen fur kontinuierliche Laser bei Stickstofftemperatur.
TL;DR: Detailed studies on the hydrolysis of p-acetylphenyl sulphate and oestrone sulphate by rat liver preparations strongly indicate that arylsulphatase C and ostrogen sulphatase are the same enzyme, being localized mainly in the microsomal fraction.
Abstract: Detailed studies on the hydrolysis of p -acetylphenyl sulphate and oestrone sulphate by rat liver preparations strongly indicate that arylsulphatase C and oestrogen sulphatase are the same enzyme. Liver is the richest source of both enzymes, which have identical intracellular distributions, being localized mainly in the microsomal fraction. Low oestrogen sulphatase and arylsulphatase C activities were present in foetal liver and these increased at a similar rate after birth. The activities of the enzymes in an ethionine-induced hepatoma were similarly low. Results of heat inactivation, mixed-substrate and competitive-inhibition experiments employing liver microsomal fractions were also consistent with one enzyme being involved. Oestradiol-17β 3-sulphate was also hydrolysed by microsomal preparations and activity towards both this substrate and oestrone sulphate was inhibited by oestrone and oestradiol-17β. The physiological significance of this inhibition is discussed.
TL;DR: A rapid and sensitive biochemical method is described for determining the lecithin concentration in amniotic fluid and can be completed in about 3 hours in samples of less than 1 ml.
TL;DR: Two recent analyses of the reflectance problem now make it possible to interpret the Kubelka-Munk coefficients in terms of the more familiar scatter ing and absorption cross sections.
Abstract: B. J. Brinkworth Department of Mechanical Engineering, University College, Cardiff, Wales, U.K. Received 21 December 1971. The methods of Kubelka and Munk, for the prediction of reflection by particulate suspensions, have been widely used in the paint and paper-making industries. In the two-flux theory on which these methods are based, the absorption and scattering properties of the suspension are represented by the coefficients K and S, respectively. There has long been uncertainty about the physical meaning of these coefficients, limiting the appeal of a theory that is otherwise attractively simple. Two recent analyses of the reflectance problem now make it possible to interpret these coefficients in terms of the more familiar scatter ing and absorption cross sections. Mudgett and Richards, comparing results obtained by the Kubelka-Munk method and by a many-flux method, obtained empirically the relations
TL;DR: In this paper, a three phase transformer test facility has been used for measuring the localized power loss and flux distribution within the core of a core with simple double overlap joints, and the flux density distribution was measured by an array of search coils wound on individual laminations.
Abstract: A three phase transformer test facility has been used for measuring the localized power loss and flux distribution within the core. The flux and loss distributions in the T-joint of a core with simple double overlap joints have been investigated. The flux density distribution was measured by an array of search coils wound on individual laminations, and the localized power loss was found by measuring the initial rate of temperature rise using miniature thermocouples. For measurements made in the range of flux densities from 1.1 to 1.6 T, the inner edges of the yoke and limb laminations were the highest loss areas, up to 30% higher than the mean core loss. These regions of high power loss were found to be due to a high third harmonic flux density component being present. The fundamental component of flux density tended to follow the rolling direction of both yoke and limb laminations; however, some deviation from the rolling direction was present in the case of other harmonics.
TL;DR: It is concluded that pyruvate oxidation is probably limited by the respiratory chain in state 4 and by the NAD-linked isocitrate dehydrogenase in state 3, and the oxidation of 2-oxoglutarate by swollen mitochondria is also stimulated by high concentrations of ADP and phosphate, and is not uncoupled by arsenate.
Abstract: 1. High rates of state 3 pyruvate oxidation are dependent on high concentrations of inorganic phosphate and a predominance of ADP in the intramitochondrial pool of adenine nucleotides. The latter requirement is most marked at alkaline pH values, where ATP is profoundly inhibitory. 2. Addition of CaCl2 during state 4, state 3 (Chance & Williams, 1955) or uncoupled pyruvate oxidation causes a marked inhibition in the rate of oxygen uptake when low concentrations of mitochondria are employed, but may lead to an enhancement of state 4 oxygen uptake when very high concentrations of mitochondria are used. 3. These properties are consistent with the kinetics of the NAD-linked isocitrate dehydrogenase (EC 1.1.1.41) from this tissue, which is activated by isocitrate, citrate, ADP, phosphate and H+ ions, and inhibited by ATP, NADH and Ca2+. 4. Studies of the redox state of NAD and cytochrome c show that addition of ADP during pyruvate oxidation causes a slight reduction, whereas addition during glycerol phosphate oxidation causes a `classical' oxidation. Nevertheless, it is concluded that pyruvate oxidation is probably limited by the respiratory chain in state 4 and by the NAD-linked isocitrate dehydrogenase in state 3. 5. The oxidation of 2-oxoglutarate by swollen mitochondria is also stimulated by high concentrations of ADP and phosphate, and is not uncoupled by arsenate.
TL;DR: A high frequency of partial leucocyte dysfunction against staphylococci was found in ten out of sixty-three children with Down's syndrome living at home and in six out of twenty-five children with acute leukaemia.