Showing papers by "Queen's University Belfast published in 1973"
TL;DR: The axiomatic definition method proposed in reference [5] is extended and applied to define the meaning of the programming language PASCAL with the exception of real arithmetic and go to statements.
Abstract: The axiomatic definition method proposed in reference [5] is extended and applied to define the meaning of the programming language PASCAL [1]. The whole language is covered with the exception of real arithmetic and go to statements.
413 citations
TL;DR: The role of the root system in the upward transport of nitrogen from the xylem to the shoot is discussed in this paper, where it is shown that the root can produce organic compounds from the nitrate or other forms of inorganic nitrogen.
Abstract: This paper reviews current knowledge and presents some new information on the metabolism of nitrogen in various species of higher plants. The role of the root system is considered. It is shown that the roots of many herbaceous and woody plants can manufacture organic compounds of nitrogen from the nitrate or other forms of inorganic nitrogen they absorb from the medium. The extent to which they do this varies greatly with the age and nutrition of the plant and with the environmental conditions under which it is growing. The relationship is examined between the synthetic activities of the root and its activity in upward transport of nitrogen to the shoot. The latter process takes place predominantly, if not exclusively, in the xylem, and in each species one or more nitrogen-rich compounds, e.g., amides, ureides and amino acids, carry the bulk of the nitrogen leaving the root. A second group of plants is described in which roots do not function to any extent in the reduction of nitrate. Consideration is given to the fate of recently absorbed nitrogen once it reaches the shoot system. An inorganic source such as nitrate, or molecules such as amides containing surplus amino groupings, are shown to serve as nitrogen sources for synthesis of amino acids required for protein synthesis. Some of these amino acids arise directly from the photosynthetic apparatus. Alternatively, surplus nitrogen arriving from the root may be stored in the shoot, from where it is drawn upon extensively if uptake by the root fails to keep pace with the shoot's demands for nitrogen. The transport system for nitrogen is examined for the whole plant. The classes of sources and sinks for nitrogen are described, and information presented on the types of nitrogenous solutes they receive from the xylem and phloem.
362 citations
Monograph•
01 Jan 1973TL;DR: The use of statistical methods as an integral part of biological investigation is discussed in this article, where the author argues that the difficulties do not lie in mathematical manipulation, but in grasping a few simple, but unfamiliar concepts.
Abstract: This introductory text presents the use of statistical methods as an integral part of biological investigation, yet one whose superficial complexities have deterred many biologists from using them. The author argues that the difficulties, such as they are, do not lie in mathematical manipulation, but in grasping a few simple, but unfamiliar concepts. He emphasizes the need for precisely defining problems and for careful selection of the most appropriate methods - a wide range of which are described and illustrated. Each chapter ends with a set of problems which are intended to help the student gain practical experience. No previous knowledge is assumed, and the student is encouraged to develop a competent and critical approach to analysing numerical data. In this second edition, the scope of the book has been extended, problems have been solved in a more satisfactory way, and a greater number of illustrative examples have been added.
313 citations
TL;DR: In this paper, Radiocarbon dates for a number of pollen analytic features marking important vegetational changes in the Post-glacial of the British Isles are plotted in two figures (Figs 2 and 3, summarized in Fig. 4).
Abstract: SUMMARY Radiocarbon dates for a number of pollen analytic features marking important vegetational changes in the Post-glacial of the British Isles are plotted in two figures (Figs. 2 and 3, summarized in Fig. 4). Despite the limitations of the radiocarbon method it becomes clear, where sufficient dates are available, that most of the vegetational developments of the earlier part of the Post-glacial are diachronous. Some of these changes have been used as pollen zone boundaries. The elm decline appears synchronous, however, within the limits of the methods, and the final pine decline in Ireland, which is shown to be older than supposed by Jessen (1949), appears to be one of the least diachronous of the horizons examined. Marked differences in the dates of similar vegetational changes within a small area, and between upland and lowland, are pointed out.
195 citations
TL;DR: In this paper, simple theories of government coalition formation are described and tested, and a statistical method is presented for comparing the theories and evaluating each of them relative to a certain null hypothesis.
Abstract: Several simple theories of government coalition formation are described and tested. A statistical method is presented for comparing the theories and evaluating each of them relative to a certain null hypothesis. The statistical tests are based upon the formation of 132 government coalitions in twelve countries of Western Europe during 1945–71.
123 citations
TL;DR: It is envisaged that the leaf cell membranes suffer a physical change at 5 °C which reduces the rates of respiration and photosynthesis, but allows the passage of water and electrolytes out of the cells; the water evaporates away but electrolytes become concentrated in the walls and can be leached out of a leaf.
Abstract: When cucumber plants are chilled at 5 °C and 85 per cent, r.h. the leaves wilt rapidly and lose water. Chlorophyll is lost in the light, but not in the dark. If chilled leaves are placed in water, electrolytes leak out rapidly, the amount depending on the duration of chilling. There are marked reductions in the rates of respiration and photosynthesis; Q10 for respiration is 5 0 between 15 and 5 °C. Phospholipid levels decline, but more slowly than the rate of water loss. Leaves recover their initial fresh weight, rate of electrolyte leakage, and respiration and photosynthesis rates if the plants are returned to warm conditions within 1 to 2 d. When leaves are chilled at 100 per cent r.h. they do not lose water or phospholipids; electro lyte leakage is little more than in controls, but respiration and photosynthesis are reduced as at 85 per cent r.h. It is envisaged that the leaf cell membranes suffer a physical change at 5 °C which reduces the rates of respiration and photosynthesis, but allows the passage of water and electrolytes out of the cells; the water evaporates away but electrolytes become concentrated in the walls and can be leached out of the leaf. As water is lost from the leaf symptoms of dehydration appear. Phospholipid loss may be associated with enzyme action following the loss of compart mentation.
102 citations
TL;DR: A good response to the drug was obtained in 68% of patients in whom its effects could be assessed and it was frequently effective where lignocaine had failed.
102 citations
TL;DR: Ketamine possesses many unique properties, such as ability to be given by the intravenous or intramuscular route, and the production of profound analgesia without cardiovascular depression, which could make it superior as an induction agent to any other at present in clinical use provided the post-operative problems could be minimized.
Abstract: Ketamine first became available in Britain for clinical trial in January 1970, but early results revealed a high incidence of delirium and unpleasant dreams during the recovery period.’ These sequelae were particularly severe in unpremedicated patients undergoing minor gynaecological operations lasting less than 15 min. Published studies have shown the importance of the dose of ketamine,’ presupplementation of a n a e s t h e ~ i a , ~ . ~ sex of the ~ a t i e n t , ~ and the type and duration of in determining the nature and severity of sequelae. Fig. 1 summarizes the incidence of undesired effects found in the studies from this centre and shows the need for further investigations. Ketamine possesses many unique properties, such as ability to be given by the intravenous or intramuscular route, and the production of profound analgesia without cardiovascular depression. These could, in certain circumstances, make it superior as an induction agent to any other at present in clinical use, provided the post-operative problems could be minimized. It was thus felt that a study of adjuvants which would further reduce these sequelae was indicated, and this paper shows how acceptable results can be obtained in general surgical patients.
92 citations
TL;DR: The developmental sequence is such that the right-hand take-over appears to occur on the basis of cross-education rather than of direct practice by the right hand itself, and lends support to a maturational, rather than a social pressure, explanation of lateral asymmetry.
Abstract: Summary. The development of eye-hand co-ordination and ‘handedness' was investigated in normal infants aged from 20 to 52 weeks. Systematic cinema records were made of visuo-manual behaviour in the single cube, pellet and bell situations from the Gesell developmental examination. These were subsequently analysed to provide a series of curves which elucidate the trends in the development of integrated visuo-motor behaviour during the period studied. The developmental process is complicated by the related problem of the systematic changes that apparently occur over the same period in lateral asymmetry (‘handedness’). Several indices of ‘handedness' confirmed a marked predominance of the left hand in the youngest age groups. Consistently over the three test situations, and probably significantly in its relationship to the eye-hand linkage, this initial ‘left-handedness' gives way during the third quarter of the first year to right-hand dominance. The way in which the shift occurs lends support to a maturational, rather than a learning or social pressure, explanation of lateral asymmetry. Moreover, the developmental sequence is such that the right-hand take-over appears to occur on the basis of cross-education (bilateral transfer) rather than of direct practice by the right hand itself.
80 citations
TL;DR: It is suggested that the decline in phospholipid level at senescence destroys mem brane integrity and allows leakage and the glyolipids begin to disappear at the same time as chlorophyll, 2 weeks before weight loss starts.
Abstract: At a late stage in senescence cucumber cotyledons lose fresh weight rapidly ; at the same time there is an increase in apparent free space and large quantities of electrolyte leak out when discs of cotyledon tissue are floated on water It is concluded that tonoplast and plasma membrane become leaky at this time Phosphatidyl choline, the major phospholipid present, begins to disappear once the cotyledons reach maximum fresh weight ; by the time rapid water loss starts, 56 per cent has gone, and phosphatidyl ethanolamine and inositol start to disappear Only at maturity is there enough of these phospholipids to furnish more than two complete membranes around each cell ; it is suggested that the decline in phospholipid level at senescence destroys mem brane integrity and allows leakage The glyolipids begin to disappear at the same time as chlorophyll, 2 weeks before weight loss starts
79 citations
TL;DR: In this paper, the absorption spectra and extinction coefficients for triplet-triplet and photodecomposition product absorption in Rhodamine 6G-ethanol solution are reported.
TL;DR: In this article, single crystals of silver were cleaned by electron-and argon-ion bombardment under conditions of ultra-high vacuum, and the work function of the (111) surface, measured photoelectrically, was (4.74 ± 0.02) eV.
Abstract: Single crystals of silver were cleaned by electron-and argon-ion bombardment under conditions of ultra-high vacuum. The work function of the (111) surface, measured photoelectrically, was (4.74 ± 0.02) eV. Oxygen adsorption caused an increase in the work function of about 0.4 eV.
Unter Ultrahochvakuumbedingungen wurden Silber-Einkristalle mittels Elektronenund Argonionenbeschus gesaubert. Die photo-elektrisch gemessene Austrittsarbeit der (lll)-Oberflache betrug (4,74 ± 0,02) eV. Sauerstoffadsorption verursacht eine Zunahme der Austrittsarbeit von etwa 0,4 eV.
TL;DR: In this article, a series of tests on model anchor plates in sand are described in the form of dimensionless force coefficients and shape factors relating failure loads to the geometry of the anchor and its depth of embedment.
Abstract: There are many situations in civil engineering where vertical earth anchors must be used to withstand horizontal loading. A series of tests is described on model anchor plates in sand. The results are presented in the form of dimensionless force coefficients and shape factors relating failure loads to the geometry of the anchor and its depth of embedment. The method of stress characteristics is used to produce comparable theoretical values which agree well with experimental results at both model and field scales. The measured shape factors are independent of the size of the plate, and this contrasts with the force coefficients which decrease with increasing anchor size. A theoretical solution has been developed which allows φ to vary in a failure zone, depending on stress levels in the computations, and the effect is shown to be important. Difficulties in selecting suitable φ-values for design are outlined, and possible design procedures examined.
TL;DR: In this paper, the fluorescence lifetimes of the normal and photoisomer forms of this mode-locking dye have been measured directly with a picosecond streak camera and shown to both have the same value of ≈330 psec.
TL;DR: The gross morphology and fine structure of the newly excysted juvenile fluke are described and the muscle is identical with that of the adult and the parenchyma is also very similar to the adult, although it has more lipid droplets and is associated in a less complex way with cells of other organ systems.
TL;DR: Triplet-triplet absorption spectra and extinction coefficents for anthracene, naphthalene, 2,5-diphenyloxazole, 7-diethylamino-4-methyl coumarin and 4-methyl-7-amino-carbostyril in ethanol are reported in this paper.
TL;DR: Antibodies raised in rabbits against porcine pancreatic glucagon and glucagon-like immunoreactivity of pig ileum were coupled to Sepharose 4B and purified into three immunoreactive components by electrophoresis.
TL;DR: A review of the principal morphological features of thecideidines corroborates the evidence of the ultrastructure of the shell that the Suborder was caenogenetically derived from spiriferide rather than strophomenide brachiopods.
Abstract: Secretion of the exoskeleton of Thecidellina barretti proceeds in the same way as in other living brachiopods, but the structure of the mantle edge is different. Mucin cells occupy the core of the outer mantle lobe, and periostracal secretion begins within a slot separating lobate cells charged with secretion droplets from long vesicular cells. The former exude an impersistent mucopolysaccharide film and may be regarded as an integral part of the generative zone; the latter secrete most of the periostracum and, thereafter, the carbonate succession as they become part of the outer epithelial layer of the mantle. The periostracum consists of an outer coat initially differentiated into a triple-unit structure and a polysaccharide layer. It is rarely more than 200 nm thick except at the hinge-line where it forms a narrow fold secreted by columnar cells as a cover to the interareas of both valves. Papillose outgrowths of the mantle (caeca), rich in secretion droplets, arise at the mantle edges at regular intervals and persist throughout life. The distal cells are highly microvillous at first, and as they withdraw from the periostracum they secrete numerous proteinous sheaths (the brush) containing mucopolysaccharides, which become encased within the carbonate succession. As the mineral layer thickens, the caeca retreat with the mantle and periodically secrete proteinous partitions within vacated distal parts of the canals (puncta). The carbonate skeleton mainly consists of acicular and granular calcite forming a primary layer with an internal surface ornamented by tubercles, rhombic bodies, and regularly arranged pits accommodating epithelial cells underlying muscle tissue. The teeth and socket ridges, however, are composed of fibres sheathed in anastomosing proteinous sheets and stacked in alternating rows as in fibrous secondary layers found in most other articulate brachiopods. Superficial traces of fibres also occur as patches and on tubercles in both valves. A similar distribution of secondary fibres is found in T. australis; but fibres are limited to spinose outgrowths in the pedicle valve of T. hedleyi, while incipient fibres develop only on the surfaces of mature teeth in Lacazella mediterranea. Study of the shell fabric of nine fossil genera shows that a continuous fibrous secondary layer occurs in all of the earliest thecideidines. During subsequent evolution the layer became neotenously reduced in the three post-Jurassic Subfamilies of the Suborder; and, although the loss was accelerated in the Lacazellinae, the main change to a sporadic secretion of secondary shell took place during late Jurassic or early Cretaceous times in all three groups. A review of the principal morphological features of thecideidines, on balance, corroborates the evidence of the ultrastructure of the shell that the Suborder was caenogenetically derived from spiriferide rather than strophomenide brachiopods.
TL;DR: The results of the experiments presented here support the hypothesis and suggest the possibility that both CSF and interferon may be mutually antagonistic regulators of cell division.
Abstract: INTERFERON preparations have been shown to inhibit the multiplication of tumour cells in vitro1–4 and more recently comparable preparations have also been shown to inhibit normal cell division. Thus, inhibition has been observed in %of mouse embryo fibroblasts5, of weanling mouse kidney5, of stimulated mouse lymphocytes6 and of the formation of granulocyte/macrophage colonies derived from mouse and rabbit bone marrow7–9. In the course of investigating the effect of mouse and rabbit interferons from different sources on bone marrow colony formation in agar, it became apparent that a strict correlation did not always exist between the antiviral titre and the colony inhibiting titre of interferon preparations derived from cell culture interferon, whereas it did exist when interferon preparations derived from mouse serum or brain were used. The development of granulocyte/macrophage colonies in agar is dependent upon the presence and concentration of colony stimulating factor (CSF)10, so the most likely explanation for the lack of correlation observed in testing some interferon preparations was the presence of significant amounts of CSF in these preparations. The results of the experiments presented here support this hypothesis and suggest the possibility that both CSF and interferon may be mutually antagonistic regulators of cell division.
TL;DR: It is shown that patients with regressing warts that did regress did so most commonly within nine months of onset and, occasionally, wart-virus-specific IgM was found and non-regressing wart lesions often did not.
TL;DR: In this paper, the authors used a streak-camera to measure 1 mJ pulses at the beginning of the pulse train of a mode-locked Nd: glass laser, with self-phase modulation frequency broadening at the end of the train.
TL;DR: Submittal of an algorithm for consideration for publication in Communications of the A C M implies unrestricted use of the algorithm within a computer is permissible.
Abstract: Submittal of an algorithm for consideration for publication in Communications of the A C M implies unrestricted use of the algorithm within a computer is permissible. Copyright © 1973, Association for Computing Machinery, Inc. General permission to republish, but not for profit, all or part o f this material is granted provided that A C M ' s copyright notice is given and that reference is made to the publication, to its date of issue, and to the fact that reprinting privileges were granted by permission of the Association for Computing Machinery.
TL;DR: Values obtained in human, rat, pig, dog, cat, ox and sheep liver indicated that in vitro, appreciable degradation of lysine to saccharopine occurred.
Abstract: The enzymes involved in the initial degradative steps of lysine metabolism, lysine–2-oxoglutarate reductase and saccharopine dehydrogenase, were studied and their activities in different mammals compared. Values obtained in human, rat, pig, dog, cat, ox and sheep liver indicated that in vitro, appreciable degradation of lysine to saccharopine (4–6nmol/min per mg of protein) occurred. The specific activity of saccharopine dehydrogenase in most species studied was higher than that of lysine–oxoglutarate reductase. The rate of production of glutamate from saccharopine in each animal species was investigated and related to the rate of production of α-aminoadipate. The rate of formation of lysine from saccharopine, catalysed by saccharopine oxidoreductase, was examined and correlated with the dietary intake of lysine in each species studied.
TL;DR: The overall effect appears to be an increase in intracellular digestive processes, including autolysis, and it is suggested that this may be a consequence of the host attempting to maintain its nutritional requirements under parasitic stress.
Abstract: Histochemical studies of the digestive gland of Lymnaea truncatula have revealed features of the normal digestive processes in which at least 3 cell types are involved: digestive cells, mucus cells and basiphil cells. An intracellular vacuolar digestive system containing lysosomal enzymes appears to operate in the digestive cells. Parasitization by Fasciola hepatica evokes considerable structural and histochemical changes in the host digestive gland. There is, in general, increased cellular vacuolation together with increased lysosomal enzyme activity. The overall effect appears to be an increase in intracellular digestive processes, including autolysis, and it is suggested that this may be a consequence of the host attempting to maintain its nutritional requirements under parasitic stress. Starvation of un-infected specimens induces structural and histochemical changes which closely resemble the effects of parasitization.
TL;DR: Lactoperoxidase (EC 1.11.1.7) was a more efficient catalyst than chloramine-T for the incorporation of 125 I into secretin and showed that only the N-terminal histidyl residue of the hormone had been iodinated.
TL;DR: It is now clear that the digestive diverticula of Nucula serve an absorptive and digestive function, however, that only fluid and particles of macromolecular dimensions resulting from extracellular digestion in the gastric cavity are able to enter the Diverticula.
Abstract: The digestive diverticula of Nucula sulcata consist of non-ciliated main ducts, ciliated secondary ducts and blind ending tubules. The cells lining the main ducts are of one type characterized by well-developed microvilli, iron-containing pigment spheres and, in animals fixed soon after collection, considerable amounts of lipid. The cells undergo a process of apocrine secretion and it is possible that they are involved in the absorption and metabolism of lipids. The ciliated cells lining the secondary ducts exhibit features similar to those lining the main ducts. The epithelium lining the tubules consists of two cell types, pyramid-shaped, basiphilic cells and columnar, digestive cells. The basiphilic cells possess a single flagellum and a well-developed rough endoplasmic reticulum and Golgi apparatus; they appear to secrete a proteinaceous product. There is no evidence that they serve to replace the digestive cells. The digestive cells, as in other bivalves, are filled with membrane-bound vesicles and possess distinct Golgi elements characterized by the presence of intracisternal membranes. Feeding experiments using ferritin show that the membrane-bound vesicles constitute a lysosomal system within which exogenous material is digested. The morphological features and the histochemical properties of the pinosomes, heterophagosomes, heterolysosomes and residual bodies are described. Contrary to the results obtained from earlier work it is now clear that the digestive diverticula of Nucula serve an absorptive and digestive function. The mode of functioning of the diverticula is such, however, that only fluid and particles of macromolecular dimensions resulting from extracellular digestion in the gastric cavity are able to enter the diverticula. Peroxisomes occur in the basal regions of all the cell types; the appearance of the contained nucleoids differs in each cell type.
TL;DR: In this article, the second harmonic of the output of a high-power, narrow-band, frequency tunable dye laser has been selectively excited by the MgI level of the laser.
Abstract: The $3s3p{^{1}P_{1}}^{\ensuremath{\circ}}$ level of Mg i has been selectively excited by the second harmonic of the output of a high-power, narrow-band, frequency tunable dye laser. The excited-state absorption series $3s3p{^{1}P_{1}}^{\ensuremath{\circ}}\ensuremath{-}3\mathrm{snd}^{1}D_{2}$ has been recorded to $n=24$. A strong autoionization resonance has been obtained at $\ensuremath{\lambda}=300.9$ nm, with a photoionization cross section of \ensuremath{\sim}5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}16}$ ${\mathrm{cm}}^{2}$, in very good agreement with the values predicted by calculation.
TL;DR: In this article, experiments were carried out on the friction welding of mild steel tubular specimens having an outside diameter of 19 mm and inside diameter of 12.7 mm, and the average rubbing speed was varied from 0.42 m/s to 3.36m/s and the axial force from 2.4 kN to 19 kN.
TL;DR: In this paper, a quantum efficiency of ≈ 0.01 for the generation of the photoisomer of DODCI has been obtained, and the establishment of equilibrium concentrations for the two forms of the dye in mode-locked rhodamine dye lasers has been confirmed.