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Showing papers by "Lancaster University published in 1971"


Journal ArticleDOI
01 Jun 1971-Planta
TL;DR: It is concluded that ABA has a greater effect on ion uptake into guard cells than into the leaf tissues as a whole, and evidence from several sources suggests that starch disappearance occurs simultaneously with K+ entry into guard Cells.
Abstract: Abscisic acid (ABA) at a concentration of 100 μm reduced the mean stomatal aperture on isolated epidermis of Commelina communis from 9.5 to 3.1 μm. This closure resulted from a fall in osmotic pressure of the guard cells from 14.1 to 9.8 bars; the osmotic pressure of the subsidiary cells did not change significantly. Histochemical tests showed that the potassium concentration in guard cells was reduced by ABA-treatment, while the starch content of the chloroplasts increased. ABA was found to exert a significant effect on Rb86 uptake into leaf discs, but this was relatively small in magnitude. It is concluded that ABA has a greater effect on ion uptake into guard cells than into the leaf tissues as a whole.

117 citations


Journal ArticleDOI
18 Jan 1971-Nature
TL;DR: In this article, measurements have been made to determine the seismic structure along the eastern branch of the East African Rift System (EARSS) in order to determine its seismic structure.
Abstract: Measurements have been made to determine the seismic structure along the eastern branch of the East African Rift System.

106 citations


Journal ArticleDOI
01 Jun 1971-Planta
TL;DR: Apical dominance in Xanthium strumarium was influenced by the quality of illumination received at the end of the photoperiod, and the involvement of the red/far-red regions of the spectrum was apparent.
Abstract: Apical dominance in Xanthium strumarium was influenced by the quality of illumination received at the end of the photoperiod. The involvement of the red/far-red regions of the spectrum was apparent. The persistence of the effects was partially dependent on the age of the individual buds concerned. Plants receiving 30 minutes of illumination from tungsten lamps after a 16-hour photoperiod from fluorescent tubes failed to branch, whereas plants given an identical photoperiod, both in terms of day-length and photosynthetically available light energy, but lacking the far-red from tungsten lamps, branched profusely.The influence of the spectral distribution of illumination on the levels of cytokinins and abseisic acid in the plant, and the correlation with the degree of branching, is presented and discussed. The cytokinin content was much higher in inhibited than released buds. The cytokinins present were probably not able to particinate in bud growth because of an accumulation of inhibitors resembling abscisic acid. The concentration of the inhibitors in inhibited buds was 50 to 250 times that occurring in all other plant parts examined.

92 citations


Journal ArticleDOI
01 Jun 1971-Planta
TL;DR: Isolated epidermal strips of Commelina communis L. showed progressively smaller stomatal openings when incubated in abscisic acid solutions ranging in concentration from 10-8 to 10-4 M.
Abstract: Isolated epidermal strips of Commelina communis L. showed progressively smaller stomatal openings when incubated in abscisic acid solutions ranging in concentration from 10-8 to 10-4 M. The effects were reproducible and did not appear to be affected by the presence of auxin, gibberellic acid or kinetin. This specificity suggests that this method may prove valuable as a quick, sensitive bioassay for abscisic acid and other related compounds which might be used as antitranspirants on field crops. The fungal toxin fusicoccin, previously reported to cause increased stomatal opening on intact leaves, partially reversed the closure induced by abscisic acid.

86 citations


Journal ArticleDOI
TL;DR: In this article, the development of scales of motivation, study methods and examination technique is reported, together with evidence of test/retest reliability Validity is inferred from correlations with the Brown-Holtzman scales and with a criterion of academic performance obtained for 898 university students, 562 college of education students and 190 students in polytechnics and colleges of technology.
Abstract: Summary The development of scales of motivation, study methods and examination technique is reported, together with evidence of test/retest reliability Validity is inferred from correlations with the Brown-Holtzman scales and with a criterion of academic performance obtained for 898 university students, 562 college of education students and 190 students in polytechnics and colleges of technology Multiple correlation coefficients indicate improvements on A-level grades through the use of these scales together with measures of academic aptitude and personality

78 citations


Journal ArticleDOI
TL;DR: In this paper, a game between two players who choose from a collection of objects is considered, where players make their choices alternately and the value or amount that the ith player will gain if he selects the jth object.
Abstract: This paper considers a game between two players who choose from a collection of objects. The players make their choices alternately and Vi,j represents the value or amount that the ith player will gain if he selects the jth object. In relation to these values, the players may have various strategies or approaches to the game, and each of them constitutes a distinct theoretical problem. The paper formulates and solves three of these problems, each one having practical significance for example, for the draft of professional football players.

65 citations


Journal ArticleDOI
TL;DR: Analysis of the growth of seedlings of Urtica dioica on a woodland soil shows that in well-illuminated situations, the large response to addition of phosphate is caused by a high rate of absorption which allows a short period of high relative growth rate related to a rapid, but transient, increase of leaf area ratio.
Abstract: Summary Analysis of the growth of seedlings of Urtica dioica on a woodland soil shows that in well-illuminated situations, the large response to addition of phosphate is caused by a high rate of absorption which allows a short period of high relative growth rate related to a rapid, but transient, increase of leaf area ratio. Without addition of phosphate, both relative growth rate and leaf area ratio remain almost constant over this same period. The relative increase of leaf area ratio caused by addition of phosphate is greatly reduced in shade. Neither in the rate of absorption of phosphate from dilute solutions, nor in the production of dry matter relative to the quantities of phosphate absorbed, does Urtica appear to differ significantly from species which show a much smaller response to phosphate on this type of soil.

62 citations


Journal ArticleDOI
TL;DR: In this article, the reaction e−+p→e−++p+πo has been studied in the region of the first pion nucleon resonance and the results on the variation with k2 of the multipole amplitudes M1+, E1+, S1+ and So+ contribute to the resonant partial wave.

58 citations




Journal ArticleDOI
TL;DR: In this article, hot electron transport and emission have been studied for Au-SiO-Au thin film cold cathodes with oxide thicknesses in the range 100-6400 A. The devices were observed to undergo an electro-forming process on application of a d.c. bias.
Abstract: Hot electron transport and emission have been studied for Au-SiO-Au thin film cold cathodes with oxide thicknesses in the range 100–6400 A. The devices were observed to undergo an electro-forming process on application of a d.c. bias, as described previously. Electron attenuation lengths in the gold layer were found to be in the range 1000–3000 A and to increase with applied bias, in strong contrast with tunnel cathode structures. Attenuation lengths in the oxide layer were ∼ 700 A. Electrons were emitted with energies up to the full applied bias and it is estimated that these electrons can acquire excess energies of up to 4·7 eV by excitation in the oxide layer. No correlation was observed between the areas of the devices yielding electroluminescence and electron emission.

Journal ArticleDOI
TL;DR: In this paper, changes in political decision-making outputs and trading activities in the European Economic Community are examined around three quasi-experimental events (formation of the EEC in 1958, first agricultural package in 1962, and the agricultural crisis in 1965-66).
Abstract: Changes in political decision-making outputs and trading activities in the European Economic Community are examined around three quasi-experimental events (formation of the EEC in 1958, first agricultural package in 1962, and the agricultural crisis in 1965–66). On the basis of a preliminary analysis, nine variables were selected for inclusion in the study (three political decision variables and six trade indicators); these were then subjected to “interrupted time-series analysis,” through which the quasi-experimental effects of the three events were assessed for statistical significance ( t -tests and autocorrelation measures) and theoretical validity (through the elimination of plausible rival interpretations). Political integration in the EEC is viewed as (1) positive growth in system indicators, and (2) increased mutual responsiveness among the major components or subsystems of the EEC. Results of the quasi-experimental analyses suggest that despite high positive growth in the selected variables, mutual responsiveness among system parts remains quite low; therefore, the principal conclusion drawn is that the EEC is a “weakly” integrating system—a collection of structures growing rapidly in many directions, with each structure very imperfectly responsive to the behavior of others. The paper urges and attempts to demonstrate the methodological usefulness of applying the logic of experimentation to ex-post-facto research. This approach entails the demonstration that non-random variation in independent and dependent variables has occurred, that these variables are related in some way, and that the relationship is nonspurious—that is, that the important confounding variables have been controlled by eliminating plausible rival hypotheses through statistical and analytical procedures.

Journal ArticleDOI
TL;DR: The light stimulated incorporation of label from 14C-labelled glycine and succinic acid into chlorophyll by isolated intact etioplasts indicates the presence of δ-amino-levulinic acid (δ-ALA) synthetase within the higher plant plastid.

Journal ArticleDOI
TL;DR: When dark-grown plants are illuminated, the characteristic morphology of the etioplast changes, resulting in the outgrowth of regularly spaced tubules from the prolamellar body into the stroma, and two types of protein body are observed, the ' stromacentre' and a 'crystallite' which is only observed under certain conditions.
Abstract: SUMMARY When dark-grown plants are illuminated, the characteristic morphology of the etioplast changes. The tubules of the paracrystalline prolamellar body disperse as the membranes reorganize and 'grow out' as 'perforated' thylakoids. Similar changes are expected during the greening of the isolated etioplasts of Avena. Under certain preparative conditions the morphological changes vary from those previously reported for intact tissue. Following low illumination at a low temperature the process of outgrowth is slowed down, resulting in the outgrowth of regularly spaced tubules from the prolamellar body into the stroma. These tubules appear to develop slowly into normal thylakoids by a process of tubule fusion to form perforated thylakoids. A diagram is included to show how this is believed to take place. The outgrowing tubules have an outer diameter of 25—28 nm with a lumen of 7-0-7-6 nm diameter. Two types of protein body are observed, the ' stromacentre' which is a regular feature of Avena plastids and a 'crystallite' which is only observed under certain conditions. The 'stromacentre' is a fibrillar spherulite with fibrils (diameter 9 nm) in bundles up to 200 nm long which in turn are aggregated to form the characteristic spherulite of the stromacentre. The crystallite is composed of fibrils 7-5-8-5 nm in diameter lying parallel to each other with a regular spacing of 125 nm. The crystallite appears to develop when the etioplast is damaged and has started to vesiculate. Particles which are larger than either plastid or cytoplasmic ribosomes have also been observed. These vary in diameter from 18 to 245 nm and are arranged in rows adjacent to the thylakoids.

Journal ArticleDOI
TL;DR: In this article, a mechanism of stress wave induced microfracturing is proposed as the cause of fracture surface markings, and the properties of the interfaces are established as the dominant control of hackle mark morphology.

Journal ArticleDOI
Michael Pye1
01 Jan 1971-Numen
TL;DR: Kamstra as discussed by the authors has recently published a lecture about the significance of syncretism for the phenomenology of religion, and its connection with theology, and his interest in this topic arose out of his experience of the mutual resistance set up between the syncretistic Japanese and Christianity.
Abstract: Dr. J. H. Kamstra has recently published a lecture about the significance of syncretism for the phenomenology of religion, and its connection with theology 1). His interest in this topic arose out of his experience of the mutual resistance set up between the syncretistic Japanese and Christianity, and out of his detailed study of the oldest case of syncretism in Japan, namely that brought about through the arrival of Buddhism in that country 2). He complains that since the work of H. Kraemer 3), little has been done in the analysis of syncretism, and that it has been neglected in the general study of religion. No reference to it is made at all, for example, in the 634 pages of Geo. Widengren's recent Religionsphinomenologie 4). Moreover most practitioners of the study of religion are strongly influenced by Christianity and tend to see syncretism as an illicit contamination, as a threat or a danger, as taboo, or as a sign of religious decadence. Kamstra notes that the word synkretizein was first used by Plutarch to mean \"to come to concord, just as the Cretans do when threatened by a common enemy\" and that Erasmus used it in the sense of reconciliation. Theologians in the seventeenth century began to use it also pejoratively. Kamstra himself proposes to use the word to mean: \"the coexistence of elements foreign to each other within a specific religion, whether or not these elements originate in other religions or for example in social structures\" 5). He elaborates the various ways in

Journal ArticleDOI
TL;DR: An amino acid isolated and purified from hydrolysates of a scleroprotein constituting the operculum of the gastropod mollusc Baccinum undatum has been characterized by chromatography, ultraviolet absorption spectroscopy and mass spectrometry and shown to be a halogenated tyrosine containing one atom each of chlorine and bromine substituted onto the aromatic ring.

Journal ArticleDOI
TL;DR: In this paper, the products and isomer distributions for the action of nitric acid in acetic anhydride at −15° were determined for the reaction of acylpyrroles.


Journal ArticleDOI
08 Mar 1971-Nature
TL;DR: By considering an idealized model of a shock source within a body of material beneath a free surface and examining the stress wave geometry, a theory of the formation of shatter cones was devised.
Abstract: By considering an idealized model of a shock source within a body of material beneath a free surface and examining the stress wave geometry, a theory of the formation of shatter cones is devised.

Journal ArticleDOI
01 May 1971-Weather

Journal ArticleDOI
D.H. Lyth1
TL;DR: In this paper, the shape of the ϱ-resonance is calculated, in π → ππ and in ee → φ, using elastic unitarity and a fixed-t dispersion relation; the solution contains two parameters M and Γ, the mass and width of the pi�.

Journal ArticleDOI
D.H. Lyth1
TL;DR: In this paper, dispersion relations and unitarity are used to predict low-energy cross sections in terms of the s-wave ππ phase shifts at low energies.

Journal ArticleDOI
TL;DR: Stable introverts were found to have the best study attitudes, though their examination results were not significantly better than those of the extraverts.
Abstract: Summary. 117 students taking ONC courses were tested using the Eysenck Personality Inventory and the Brown-Holtzman Survey of Study Habits and Attitudes. The relationships between the sub-scores on these scales and examination performance at the end of the first or second year of study were investigated. Stable introverts were found to have the best study attitudes, though their examination results were not significantly better than those of the extraverts. All the sub-scales of the SSHA were significantly related to academic performance, but they showed contrasting patterns of relationships with the personality dimensions.

Journal ArticleDOI
01 Jan 1971-Lithos
TL;DR: In this article, a comparison of three hypersolvus alkaline complexes of Precambrian age occuring in the same igneous province is made with respect to the degree of cooling and the extent to which excess alkalis in liquid residua were lost to the atmosphere and wall-rocks.

Journal ArticleDOI
S. Hunt1
TL;DR: Ultrastructurally and conformationally periostracum and egg capsule proteins have similarities but do not resemble operculum protein although each is probably stabilized by “tanning”.
Abstract: 1. 1. The amino acid and monosaccharide compositions of three structural proteins secreted extracellularly by the gastropod mollusc Buccinum undatum L. are reported. These are the proteins of the periostracum, egg capsule and operculum. 2. 2. The three proteins have characteristic amino acid compositions. Periostracum and egg capsule resemble α-fibrous proteins compositionally but periostracum contains hydroxyproline. Operculum is more closely comparable to β-fibroins. 3. 3. Each protein contains glucose, galactose, mannose, fucose, xylose, rhamnose, glucosamine and galactosamine. 4. 4. Ultrastructurally and conformationally periostracum and egg capsule proteins have similarities but do not resemble operculum protein although each is probably stabilized by “tanning”.

Journal ArticleDOI
TL;DR: In this paper, the Fowler-Nordheim parameters φ and A vary with silicon coverage in a manner qualitatively similar to that observed during metallic adsorption, and the field emission work function of monolayer films of Si deposited at 295K was found to be 4.72 ± 0.05 eV.

Journal ArticleDOI
TL;DR: The authors found that children between the ages of 3 and 11 years were asked to ascribe positive and negative behavioral characteristics to pictures of white and shaded figures, while the younger children, 3 and 4 years, tended to do this in a random fashion, while from the age of 9 years there was a diminution in this behaviour.
Abstract: Children between the ages of 3 and 11 years were asked to ascribe positive and negative behavioural characteristics to pictures of white and shaded figures. Whilst the younger children, 3 and 4 years, tended to do this in a random fashion, children between the ages of 5 and 8 years showed a marked increase in the attribution of negative statements to shaded figures and positive statements to white figures. From the age of 9 years there was a diminution in this behaviour. Exposure to coloured immigrant children in the school and play-group situations was associated with a decrease in this prejudicial behaviour.

Journal ArticleDOI
01 Nov 1971-Weather

Journal ArticleDOI
TL;DR: In this article, the physical principles of a pulse-echo technique in which ultrasonic waves are generated directly from rf pulses in a coil placed near a metal sample in the presence of a magnetic field are outlined.
Abstract: The physical principles are outlined of a novel pulse-echo technique in which ultrasonic waves are generated directly from rf pulses in a coil placed near a metal sample in the presence of a magnetic field. Measurements of the efficiency of this system and its possible applications to non-destructive testing are discussed.