Showing papers by "University College Dublin published in 1977"
TL;DR: The first haematopoietic sites in Brachydanio rerio are formed by the “intermediate cell mass”, situated between somite and lateral plate, and the sequential sites are in the endocardium, pro‐ and mesonephros.
Abstract: The first haematopoietic sites in Brachydanio rerio are formed by the “intermediate cell mass”, situated between somite and lateral plate. The sequential sites are in the endocardium, pro- and mesonephros. The results are compared with those of Pterophyllum scalare, which has its first blood anlage on the yolk sac.
130 citations
110 citations
TL;DR: It is suggested that cytoplasmically synthesized mitochondrial proteins exist in an extramitochondrial pool prior to import; that the site of this pool is the cytosol for at least some of the mitochondrial proteins; and that the precursors in the extamit mitochondrial pool differ in structure or conformation from the functional proteins in the mitochondria.
Abstract: The results suggest that the transport of cytoplasniically synthesized mitochondrial proteins is essentially independent of cytoplasmic translation ; that cytoplasmically synthesized mitochondrial proteins exist in an extramitochondrial pool prior to import; that the site of this pool is the cytosol for at least some of the mitochondrial proteins; and that the precursors in the extramitochondrial pool differ in structure or conformation from the functional proteins in the mitochondria. In the preceding paper we studied the transport of cytoplasmically synthesized proteins into the mitochondria in intact cells of Neurosporu crassu [l]. la whole cells, the processes of synthesis and transport are not easily separated. Furthermore, post-labelling fractionation artifacts may obscure the intracellular location of mitochondrial proteins which are on their path from the site of synthesis to the site of function. In considering systems in vitro a number of possibilities exist, ranging Crom cell-free homogenates to reconstituted systems involving isolated and purified protein and organelle components. In the present study we have investigated synthesis and transport in a cell-free homogenate. We. have employed this system in an attempt lo decide between two mechanisms currently proposed for the transport of mitochondria] proteins. The first mechanism is based on observations with whole IC’emrospora cells [l]. This mechanism proposes the existence of extramitochondrial pools of mitochondrial proteins from which they are imported into the mitochondria. The second mechanism is that proposed by Butow and his colleagues [3 - 61. This latter mechanism proposes a special class of cytoplasmic ribosomes which are attached to the mitochondria at specific sites. The nascent polypeptides from these ribosomes are discharged in a vectorial manner into the mitochondria. The results we present here support our earlier proposal on the existence of extrarnitochondrial precursors of mitochondria1 proteins [I, 21.
110 citations
TL;DR: In this article, a laser beam was focused on a target of high atomic number and the spatially resolved absorption spectrum of the laser-generated plasma was studied from 200 to 50 \AA{}.
Abstract: In a technique using a continuum generated by focusing a laser beam on a target of high atomic number, the spatially resolved absorption spectrum of ${\mathrm{Li}}^{+}$ formed in a second laser-produced plasma was studied from 200 to 50 \AA{}. The doubly excited resonances, $1{s}^{2}_{1}S\ensuremath{-}2\mathrm{snp}^{1}P$, as well as the principal series and its adjoining photoionization continuum were observed. The Fano parameters, $q$ and $\ensuremath{\Gamma}$, of the $2s2p^{1}P$ were derived from the absorption profile. Comparison is made with theory.
101 citations
TL;DR: In this paper, the same expansion in Vkd will converge in both the large U, magnetic regime, and the small U, nonmagnetic regime, for U = 0.1.
Abstract: For pt.I see ibid., vol.6, p.1375 (1976). This new method is shown to give the exact result for U=0. It is implied that the same expansion in Vkd will converge in both the large U, magnetic regime, and the small U, nonmagnetic regime.
94 citations
TL;DR: The ratio of factor VIII‐related antigen to factor VIII activity may reflect the severity of the effect of the disease process on the fetus, and an increased rate of thrombin production in women with pre‐eclampsia is suggested.
56 citations
46 citations
41 citations
TL;DR: Maximum yields of amylase were produced by the thermophilic actinomycete Thermomonospora viridis in a modified Simpson and McCoy medium containing 1.5% corn starch and 0.
Abstract: Maximum yields of amylase were produced by the thermophilic actinomycete Thermomonospora viridis in a modified Simpson and McCoy medium containing 1.5% corn starch and 0.5% mycological peptone with an initial pH 7.0. Best yields of amylase were obtained after incubation for 48 h, when the pH of the medium had risen to 8.2. Amylase was purified 313-fold by precipitation with n-propyl alcohol, dialysis against tap water, adsorption on Ca3(PO4)2, and fractionation on Sephadex G-100. Protease was produced in nutrient broth containing 0.5% starch and 1.0% corn steep liquor and at an initial pH 7.0. Maximum yields of protease were produced after 42 h. The protease was purified 54-fold by precipitation with n-propyl alcohol, dialysis against tap water, adsorption on Ca3(PO4)2, and fractionation on Sephadex G-200.
40 citations
TL;DR: In this article, it was shown that the mean energy flux velocity vector for a single infinite train of elliptically polarized harmonic small amplitude plane waves propagating in a homogeneous conservative, dispersive system is equal to the group velocity.
Abstract: By a simpler proof than was previously available (see, for example Rayleigh 1877, Lighthill 1960) it is shown that the mean energy flux velocity vector for a single infinite train of elliptically polarized harmonic small amplitude plane waves propagating in a homogeneous conservative, dispersive system is equal to the group velocity.
33 citations
TL;DR: The electronic structure of isoelectronic AM(C0)3 (AM η6-C6H6Cr, η5-C5-H5Mn,η4-C4H44Fe, Δη3-C3H5Co, Δ−2-C2H4Ni) was investigated within an extended CNDO/2 formalism using both experimental and standard geometries as mentioned in this paper.
TL;DR: It is proposed that when breakdown of adenine nucleotides in haemorrhagic hypotension proceeds as far as uric acid and allantoin, the resynthesis of ATP following reinfusion is severely limited, and the possibility that this disturbance in energy metabolism may influence the irreversibility of haem orrhagic shock is discussed.
Abstract: The concentrations of ATP, ADP and AMP in splanchnic organs, and the plasma concentrations of the end products of adenine nucleotide breakdown, were determined in experimental haemorrhagic shock. Haemorrhagic hypotension resulted in marked reduction in the ATP and the total adenine nuclectide contents of pancreas, liver and duodenum even two hours following reinfusion. Plasma hypoxanthine and uric acid increased more than ten fold during the hypotensive period, and later decreased gradually. The plasma concentration of allantoin increased dramatically during haemorrhagic hypotension and did not decrease following reinfusion. It is proposed that when breakdown of adenine nucleotides in haemorrhagic hypotension proceeds as far as uric acid and allantoin, the resynthesis of ATP following reinfusion is severely limited. The possibility that this disturbance in energy metabolism may influence the irreversibility of haemorrhagic shock is discussed. with particular reference to the pancreas.
TL;DR: The ultrastructure of the accessory outer segment (AOS) — a ciliumlike structure emanating from the inner segment and running alongside the outer segment of photoreceptors — is described and its possible occurrence in other vertebrate classes is discussed.
Abstract: The ultrastructure of the accessory outer segment (AOS)--a cilium-like structure emanating from the inner segment and running alongside the outer segment of photoreceptors--is described. The AOS occurs in both rods and cones of Poecilia reticulata. Its ultrastructure, including the arrangement of microtubules, which originate from the ciliary stalk, is the same in rods and cones. The cone-AOS is connected with the outer segment by a thin plasmabridge, whereaa the rod-AOS lies embedded within the outer segment. The outer segment of the cone, in contrast to that of the rod, is separated from the pigment epithelium by a large extracellular space. An intimate contact, however, is secured by the AOS; its membrane is closely appositioned to the pigment epithelium membrane. The functional significance of the AOS and its possible occurrence in other vertebrate classes, are discussed.
TL;DR: The β- d -glucopyranosides of zingerone, rheosmin acetoxydihydro-p -coumaryl alcohol, chavicol, benzoic acid and 2(or 4)-hydroxy-4(or 2)- methoxyprop-1-ene were isolated from the water soluble fraction of Pinus contorta needles.
TL;DR: In this article, four monolignol glucosides have been isolated and identified from the needles of Pinus contorta, including 4-O-α-L -arabinofuranosyl.
TL;DR: In this article, an ESR investigation complemented with X-ray measurements, ofcis-polybutadiene filled with a range of carbon blacks was performed to derive further insight into the rubber-carbon black interaction.
Abstract: This paper describes an ESR investigation complemented with X-ray measurements, ofcis-polybutadiene filled with a range of carbon blacks. The aim was to derive further insight into the rubber-carbon black interaction. There are two distinguishable free spin species in the carbon blacks; free spin carriers and localized free spins. There appears to be a correlation between the localized free spin concentration and defects concentrations in the carbon blacks as determined by X-ray measurements. The interpretation of experimental data emphasizes the importance of considerations of the “structure” parameter of the carbon blacks.
TL;DR: The present results of the effect of parathyrin on bone alkaline phosphatase introduce the prospect of a bioassay of greater sensitivity than the existing radioimmunoassay methods.
Abstract: on the response of bone alkaline phosphatase to parathyrin. The results of a typical experiment showing percentage change in alkaline phosphatase activity compared with the hormone-free control are presented in Fig. 2(b). Tissue from 1-day-old animals was unresponsive to parathyrin, that from the 3-day-old animal showed decreased alkaline phosphatase activity and those from 5and 6-day-old animals showed an increase in alkaline phosphatase activity. All responses were maximal at 5-8min incubation time. In bone from 5-day-old rats a dose-dependent increase in enzyme activity was observed at 7min in the range 50fg/ml-50pg/ml (Fig. 2a). This study highlights the potential of quantitative cytochemistry for studying enzyme characteristics intracellularly without prior fractionation and purification. Because of the micro-quantities of tissue involved, it becomes possible to measurechanges in cellular enzyme activity caused by sub-picogram quantities of hormone. The present results of the effect of parathyrin on bone alkaline phosphatase introduce the prospect of a bioassay of greater sensitivity than the existing radioimmunoassay methods.
TL;DR: In this paper, it was shown that the strong dual of a Frechet nuclear space is a nuclear space and that the topology generated by the absolutely convex compact subsets of a complex locally convex space is nuclear.
Abstract: LetU be an open subset of a complex locally convex spaceE, andH(U) the space of holomorphic functions fromU toC. If the dualE′ ofE is nuclear with respect to the topology generated by the absolutely convex compact subsets ofE, then it is shown thatH(U) endowed with the compact open topology is a nuclear space. In particular, ifE is the strong dual of a Frechet nuclear space, thenH(U) is a Frechet nuclear space.
TL;DR: The need for balance between qualitative and quantitative analysis in systems studies and the fact that systems theory provides a framework in which to balance generality and detail are focused on.
TL;DR: Genetic polymorphism for factors capable of inducing female sterility have been discovered in two wild populations of Drosophila melanogaster.
Abstract: Genetic polymorphism for factors capable of inducing female sterility have been discovered in two wild populations of Drosophila melanogaster. The polymorphisms exist both on the 2nd and 3rd (and possibility the X) chromosomes, and were detected by backcrossing chromosomes from the population into a multiply marked tester stock. The effect is only apparent in certain cytoplasms.
TL;DR: In this paper, the effects of intraruminal infusion with lactic acid was studied further with four sheep which received infusions of lactic acids at a fixed daily rate of 40 mmol per kg W−0·75 per d or of an equal volume of distilled water for 3-d periods while being offered grass meal pellets ad libitum.
Abstract: Four sheep in a 4 × 4 Latin Square experiment were offered ad libitum grass meal pellets alone or supplemented with lactic acid at 600, 800 or 1000 mmol per kg dry matter (DM) intake, either mixed into the feed or continuously infused intraruminally for 6-d periods. When added to the feed lactic acid did not significantly affect DM intake but when infused intraruminally it significantly reduced DM intake especially at the highest rate of infusion.
In a second 4 × 4 Latin Square experiment, four sheep were offered ad libitum grass meal pellets alone or supplemented with lactic acid mixed into the pellets at 900, 1200 and 1500 mmol per kg DM for 15-d periods. There was a small reduction in intake on the three lactic acid treatments but this was not significant.
In a third experiment the effects of intraruminal infusion with lactic acid was studied further with four sheep which received infusions of lactic acid at a fixed daily rate of 40 mmol per kg W−0·75 per d or of an equal volume of distilled water for 3-d periods while being offered grass meal pellets ad libitum. Infusion with lactic acid resulted in reduced DM intake but the effect was less consistent than in Experiment 1.
In all three experiments lactic acid supplementation had little effect on the pH and total volatile fatty acid concentration of rumen
01 Nov 1977
TL;DR: In this paper, the authors examined the hydrostatics of soft polarisable liquids in the context of four "classical" theories of the stresses in fluids, and of recent theoretical work which has resolved the controversy surrounding those theories.
Abstract: The hydrostatics of soft polarisable liquids is examined in the context of four ‘classical’ theories of the stresses in fluids, and of recent theoretical work which has resolved the controversy surrounding those theories. The classical stress systems predict various different internal pressures and magnetostrictive density changes, and only the stress system, based on energy, correctly gives the density change. The energy-based stresses proposed by Gans in 1904 generalise for nonlinear fluids the stress system of Helmholtz. All the stress systems predict the same surface variation of the pressure to contain a liquid, and they lead to a common surface-integral method useful for computing force on saturable iron bodies. The modern theories are represented, for equilibrium conditions, by a single and unique stress system which gives no information on internal forces. The meaning of the various ‘pressures’ found in the recent literature is discussed, and the role of density, rather than pressure, as the predictable mechanical variable inside a liquid is illustrated by a thought experiment.
TL;DR: In the absorption spectrum of Be+ obtained in a laser-produced plasma, transitions have been observed from the first excited state as well as the ground state as discussed by the authors, where the upper states are derived from the doubly-excited configurations 1s2p2, 1s 2s 2p and 1 s2p3p.
TL;DR: The TPHA test has proved to be more reliable than either the WR or the VDRL test, giving fewer false positive and false negative results by comparison with the FTA-ABS test.
Abstract: OUR experience of the Treponema Pallidum Haemagglutination test as a screening procedure in syphilis serology over a two year period is reported. A positive screening test was obtained in approximately 3 per cent of nearly 27,000 samples submitted. The TPHA test has proved to be more reliable than either the WR or the VDRL test, giving fewer false positive and false negative results by comparison with the FTA-ABS test.
TL;DR: The role of non-specific bacteria in the infertility of clinically normal repeat-breeder cows is reviewed, and data are presented from a recent study in which bacteriological and histological samples were taken from the uteri of dairy cows at intervals during the non-gravid period.
Abstract: The role of non-specific bacteria in the infertility of clinically normal repeat-breeder cows is reviewed, and data are presented from a recent study in which bacteriological and histological samples were taken from the uteri of dairy cows at intervals during the non-gravid period. The evidence does not support the view that endometritis is an important cause of this infertility. In the absence of accurate counts of the bacteria present in the uterus at the time of service and during the subsequent oestrous cycle, it is impossible to determine whether pathogenic bacteria cause the infertility by injuring the gametes or the developing conceptus. A comprehensive quantitative study is needed of the microbiology of the uterus of the repeatbreeder cow at service and during the subsequent oestrous cycle.
TL;DR: The findings show that the stability of alcohol in the samples is adequate to meet the reanalysis requirements prescribed in the Road Traffic Act, 1968.
Abstract: THE results obtained on reanalysis for alcohol of blood and urine samples after varying periods and conditions of storage are presented.