Showing papers by "University of Warwick published in 1971"

Compton scattering and electron momentum distributions

Abstract: The recent development of the technique of inelastic x-ray scattering to study the electron momentum distribution in the scatterer is surveyed. The simple relationship between the electron momenta and the Compton line shape in the impulse approximation is derived, and the validity of that approximation is discussed in the light of recent measurements. Current areas of research are reviewed.

Sites of Synthesis of Chloroplast Proteins

Abstract: The antibiotic lincomycin, which specifically inhibits protein synthesis on chloroplast ribosomes, has been used to investigate further the inference from genetic studies that chloroplasts are not autonomous units.

Metal/air cell

Abstract: Primary and secondary lightweight "AA," "C," "D," and the like metal/air cells comprising an anode, a cathode, and an electrolyte are described in which the anode comprises a consumable porous metal and the cathode comprises a hydrophobic member in contact at one surface with an electrocatalyst. The aforesaid components of the cell are retained in a substantially rigid protective shield and spaced therefrom permitting access of air to the cathode over substantially the entire cathode surface area. The structural elements which include the protective shield spacers to space the shield from the cathode comprise lightweight materials such as lightweight metals or a thermosetting or thermoplastic resin or the like. The electrolyte can be a solution or paste of an ion-conductive material or a water-activatable solid, such as "dry" potassium hydroxide adhering to or absorbed in the anode and/or cathode and/or a hydrophilic separator between the anode and cathode.

Persistence and degradation of chlorfenvinphos, diazinon, fonofos and phorate in soils and their uptake by carrots

Abstract: Analytical methods are described for the determination of residues of chlorfenvinphos, diazinon, fonofos and phorate in soils and carrots. The insecticides, applied in June 1969 at 2 kg (a.i.)/ha, persisted longer in peaty loam than in sandy loam. After 7 months, the sandy loam contained 1% of the applied diazinon and 20–30% of the applied chlorfenvinphos, fonofos and phorate, the latter as its sulphone; the corresponding figures for the peaty loam were 10, 40–50, 40–50 and 30–40% respectively. None of the residues showed any substantial change from October to January. Although high initial concentrations (up to 50 ppm) of the residues in carrots were diluted by plant growth, it is shown that concentrations >1 ppm could be present in marketable crops 12–14 weeks after application at recommended rates. Carrots harvested 26 weeks after sowing contained <0.2 ppm of all insecticides. In contrast, during the first 15 weeks of crop growth the weights of residues in the carrots increased and remained approximately proportional to the square root of the carrot mean weight. Rates of uptake declined as carrot growth declined and subsequently the amounts of chlorfenvinphos, diazinon and fonofos residues in the carrots changed very little, while phorate sulphone steadily declined.

Receiver tuning system

Abstract: A harmonic generator produces simulated station signals which are heterodyned in the mixer stage of a receiver. A local oscillator of the receiver is swept through its frequency bandwidth, producing an IF pulse each time the receiver tunes one of the simulated stations. The IF pulses are counted, and upon reaching a number preset on station selection switches, convert the sweep circuit to an AFC amplifier, maintaining the receiver tuned to a desired station frequency.

Measuring Inorganic Phosphate without Using a Reducing Agent

Abstract: Effect ofdiluent Reagents behave identically. If they do not, the results of the tests will be inaccurate. When using an AutoAnalyzer, errors will arise if the rates of dialysis of the standards and the tests are different. Inorganic phosphate can exist in three ionic forms and each form may have a different dialysis constant. When the pH is below 3, most of the phosphate is in the form of the H 2PO-. ion; when the pH is about 7 much of the phosphate is in the form of the HPOlion; and when the pH is above 12.6, the phosphate is mostly in the form of the PO.\"ion. To investigate the effect of the diluent on the rate of dialysis of the specimens and the calibration standards, the following experiment was carried out. A lyophillised serum, whose composition we had carefully determined beforehand, was diluted with 5 ml of water instead of the normal 10 ml, After making due allowance for the volume of the dried solids, this concentrated serum was diluted to give a series of eight 'serum standards'. The concentration of these serum standards varied from 1 to 15 mg of inorganic phosphate per 100 ml, A range of eight aqueous standards was also prepared. For each serum standard there was a corresponding aqueous standard with the same inorganic phosphate content. The aqueous standards and the serum standards When using any automated system of analysis, the were analysed using first 1% sulphuric acid and assumption is made that the standards and the tests then 0.85 % saline as both the diluent and the 168 Principle

Influence of sulphate nutrition on the flavour components of garlic (Allium sativum) and wild onion (A. vineale)

Abstract: Investigation of the relationship between the sulphate nutrition of garlic (Allium sativum) and wild onion(A. vineale) and their flavour strength is now reported. The plants were grown in a glasshouse in sand culture at two concentrations of sulphate in the nutrient medium and their flavour strength determined by sensory, biochemical and gas chromatographic methods. These observations have furnished further examples of environmental control of flavour components. The garlic plants in the two groups differed significantly in their fresh weights per plant. Their sulphur contents also showed that deficiency of this nutrient had been established in spite of the relatively large amount of sulphur introduced in the original cloves. The ratios of total sulphur content in the two groups of plants and of their flavour strengths as determined by total pyruvate values and taste threshold concentrations, respectively, were approximately constant (about 5). Total peak areas in the gas chromatograms increased with increasing (sensory) flavour strength. The garlic plants grown in sand culture were morphologically atypical, possibly because of the high moisture content of the growth medium, but their odour, taste and gas chromatograms were qualitatively indistinguishable from those of field-grown garlic which grew normally. Similar but more pronounced differences of flavour strengths were obtained with A. vineale and in this case the difference in flavour strengths between the deficient and normal plants was about 13-fold. The gas chromatograms of the deficient plants were almost completely lacking in the peaks which are characteristic of Allium sp. The discrepancies between initial and final sulphur contents of the deficient plants are discussed.

The Effect of Weed Removal at Different Times on the Yield of Bulb Onions

Abstract: SummaryIn six field experiments during 1967–70, weeds were removed by hand at different times from crops of bulb onions drilled in March on a sandy loam, and the effects on yield determined. When weeds (150–850/m2) remained for up to the first 4–6 weeks after 50% crop emergence, final yield was unaffected, provided that the crop was subsequently kept clean. If present for longer than this, the yield was reduced progressively; if weeds remained for only a further 2 weeks there was on average a 60% loss of yield.If the crop was kept clean for the first 6–8 weeks or more after 50% emergence, weeds that developed subsequently did not affect yield. There was thus a ‘critical period’, which occurred while the crop was developing the third true leaf.Loss of yield was mainly the result of decrease in bulb size, and with weeds present for the whole season, no marketable bulbs were obtained. Crop stand was also reduced when weeds remained for longer than 9 weeks after crop emergence, and full-season competition red...

The popular fear of catholics during the english revolution1

Abstract: INTOLERANCE OF CATHOLICS AND CATHOLICISM IS ONE OF THE best-known features of seventeenth-century England. In some ways it is also one of the least explored. In particular, little is known of the essential feature of this intolerance — the nature, extent and causes of the Protestant fear of Catholics. Yet without some under-, standing of such fear the growth of religious toleration, or analyses of political conflict in Stuart England — to mention only two areas — must remain in some respects shallow and incomplete. Shallow because no explanation of religious tolerance can convince until the depth of contrary prejudices are appreciated; incomplete because studies of the opposition to Charles and Archbishop Laud, of the Popish Plot hysteria, or of the growth of a rebellious consensus against James II, assume but do not analyse deep wells of hatred and fear of Catholics at all levels of society. But granted this, how can fear be measured? Merely to list assaults on Catholics would achieve little for these cases were remarkably few in the seventeenth century. Repressive legislation passed by the government is easy to catalogue but tells little of popular attitudes, and the enforcement of that legislation was too dependent upon formal administrative processes for it to be informative about public opinion. A different approach is however possible. From time to time English towns and villages were swept by panic fears of \"Catholic plots\" — most of them imaginary — to rebel and massacre Protestants. The most celebrated example is the Popish Plot, and evidence of similar rumours during the 1688 Revolution has been published. These were not, as has been supposed, the product of 1 wish to thank Mr. Robin Briggs, Mr. E. P. Thompson and Dr. J. E. C. Hill for their valuable criticisms of this article. I am also grateful to Dr. Carol Z. Wiener for permission to read her article \"The Beleaguered Isle. A Study of Elizabethan and Early Jacobean Anti-Catholicism\" before it was published in Past and Present, no. 51 (May 1971). 1 On the enforcement of recusancy legislation see J. S. Leatherbarrow,

Effects of soil moisture content on the availability of soil-applied herbicides to plants

Abstract: The phytotoxicities of atrazine, simazine, linuron, lenacil and aziprotryne were increased as the moisture content of the soil increased. Results from studies with 14C-labelled atrazine suggested that these differences could be related to differences in concentrations of herbicide accumulated by the plants. Total uptake of atrazine was directly proportional to water uptake, but a comparison of the amounts taken up with those supplied by mass-flow in the transpiration stream suggested that some exclusion factor was operative. It was concluded that herbicide transport within the soil-plant system was the main factor affecting phytotoxicity under the different soil moisture regimes. The significance of the results to herbicide behaviour under field conditions is discussed.

Optimal algorithms for parallel polynomial evaluation

Abstract: Algorithms for the evaluation of polynomials on a hypothetical computer with k independent arithmetic processors are presented. It is shown that, provided the degree of the polynomial to be evaluated exceeds k[log"2k], an algorithm given is within one time unit of optimality.

Some forms of the closed graph theorem

Abstract: In this paper we shall establish some forms of the closed, graph theorem for locally convex spaces, using the approach of Ptak(l7). Our interest is in classifying pairs of locally convex spaces (E, F) which have the property that every closed graph linear mapping T: E -> F is continuous; if (E,F) has this property then we shall say that (E, F) is in the class *&. \is# is a particular class of locally convex spaces then ^(si) is the class of all E such that (E, F)&

The fecundity of the cabbage root fly erioschia brassicae under field conditions

Abstract: Flies enclosed in large (1.8 m high × 3.0 m wide × 15.2 m long) field cages containing a section of hedgerow and a plot of brassicas laid an average of 63 eggs/female during May 1968. This represented the first batch of eggs and was equivalent to that of the flies fed on sucrose alone. The principal natural source of carbohydrate in hedgerows at Wellesbourne in May was the nectar of A. sylvestris and two Anthriscus flowers per female per day were sufficient to sustain the development and oviposition of the first batch of eggs. The average fecundity of second generation flies in field cages was very low because many of the females were killed by the fungus Empusa muscae. A thin-layer chromatographic method was used to assess the free amino acids in extracts from the abdomens of female cabbage root flies. Quantities of valine and leucine in excess of 5 μg/μl of sample and an extinction of the extract in excess of 0.2 at 505 nm indicated that such samples included females that had fed from proteinaceous materials. Using these criteria, 3 % of the flies captured from the second generation during July and August were assessed as having fed from proteinaceous sources and dissections showed that 6 % of these flies had imbibed sufficient proteinaceous material to mature the second or subsequent batches of eggs. These results suggest that 94–97 % of the females of the first and second generations of cabbage root flies at Wellesbourne feed only from carbohydrates. Under field conditions, therefore, the fecundity of the cabbage root flies was only 20–30 % of their potential fecundity. Zusammenfassung DIE FRUCHTBARKEIT DER KOHLFLIEGE, ERIOISCHIA BRASSICAE, UNTER FREILANDBEDINGUNGEN Kohlfliegen, die in einem grosen Feldkafig (15,2 m lang, 3 m breit und 1,8 m hoch) gehalten wurden, der einen Teil einer Feldhecke sowie eine mit Brassica oleracea botrytis L. bebaute Flache enthielt, legten wahrend des Mai 1968 im Durchschnitt 63 Eier pro Weibchen. Das entspricht dem ersten Satz Eier (Gelege) und gleicht der Eiproduktion von Fliegen, die nur mit Rohrzucker ernahrt wurden. Die Hauptquelle der im Mai in Hecken von Wellesbourne naturlich vorkommenden Kohlenhydrate ist der Nektar von Anthriscus sylvestris. Zwei Anthriscus-Bluten pro Weibchen und Tag genugen, um die Entwicklung und Ablage des ersten Eigeleges zu gewahrleisten. Die durchschnittliche Fruchtbarkeit der Fliegen der zweiten Generation war in den Feldkafigen sehr niedrig, da viele Weibchen durch Empusa muscae getotet wurden. Zur Ermittlung der freien Aminosauren in Hinterleibsextrakten weiblicher Fliegen wurde eine dunnschichtchromatographische Methode benutzt. Mehr als 5 μg/1 Valin und Leucin je Probe und Extinktion bei 505 μm in einem Extrakt von uber 0,2 deutet darauf hin, das solche Proben Weibchen enthielten, die sich von eiweishaltigen Stoffen ernahrt hatten. Benutzt man diese Kriterien, so zeigen 3% der wahrend Juli und August gefangenen Fliegen der zweiten Generation, das sie ihre Nahrung von eiweishaltigen Quellen bezogen. Sektionen ergaben, das diese Fliegen genugend eiweishaltige Stoffe aufgenommen hatten, um einen zweiten oder weiteren Satz Eier produzieren zu konnen. Diese Ergebnisse lassen vermuten, das sich 94–97% der Weibchen der ersten und zweiten Generation der Kohlfliege in Wellesbourne ausschlieslich von Kohlenhydraten ernahren. Deshalb betragt ihre Fruchtbarkeit unter Feldbedingungen nur 20–30% des Moglichen.

A theory for fertilizer response

Abstract: A model is derived that relates yield to levels of applied fertilizer in terms of parameters that have direct physical meaning. N8, P8, and K8 define the contribution of the soil to the supply of nitrogen, phosphorus and potassium for plant growth; BN, BP and BK define the responses to nitrogen, phosphorus and potassium fertilizer at low nutrient levels and aN is the level of nitrogen required to raise the osmotic pressure sufficiently to prevent growth.To test the model, field experiments were carried out on French beans and summer cabbage in which 125 different combinations of levels of nitrogen, phosphate and potassium fertilizers were applied. The yield data from each block of each experiment fitted the model very well. Fitted values differed from block to block but these differences could be attributed to the fact that for each block equally good fits were often obtained with widely differing parameter values. Estimates of N8 were made from chemical analysis of the (NH4 + NO3) — N of soil samples from the field plots, and P8, and K8 from chemical studies of the adsorption of phosphate and potassium on untreated soil. They were in substantial agreement with the average values obtained by the entirely different procedure of fitting the model to the yield data. Also estimated values for BN, BP and BK and aN from other chemical studies were consistent with those obtained by model fitting.It is concluded that although the theory has limitations it is broadly in accord with the results of the detailed field experiments.

Component insertion system

Abstract: An indexing conveyor transfers circuit boards between spaced insertion stations at which alignment pins clamp the circuit boards to fixed reference positions. A component insertion head and a clinch mechanism are horizontally driven about two axes to a programmed insertion position, and then are vertically driven to perform an insertion operation. After each insertion station inserts a plurality of different components at different programmed positions, the alignment pins are withdrawn and the conveyor is indexed. The index conveyor and all insertion stations are controlled by a time-shared computer which stores, for each insertion station, a separate program comprising sets of numerical control movement commands.

Non-stoichiometric vacancy order in vanadium monoxide

Abstract: An electron microscope study has been made of the nominally cubic vanadium monoxide phase. Crystals of different composition varying over the whole phase field were grown by the floating zone and cold crucible methods. In oxygen-rich specimens, after low-temperature annealing, ordered domains of a tetragonal superlattice nucleate and grow in the cubic matrix. A partial phase diagram indicating the stability limits of the ordered phase, based on isothermal heat treatments, is proposed. For each of the three cubic orientations of the tetragonal domain c-axis, sub-domains of a tetragonal superlattice with large unit cell were found to exist in twin-related orientations. The reciprocal lattice and hence structure of the superlattice was found by electron diffraction combined with the dark-field imaging technique. The unit cell content is V244O320 and contains 20 tetrahedrally coordinated interstitial vanadium atoms as well as 96 vanadium vacancies. Nous avons examine par microscope electronique la phase, nominalement cubique, VO. Nous avons fait croǐtre, au moyen des methodes de zone flottante et du creuset froid, des cristaux de composition differente, qui varie sur tout le champ de phase. Apres avoir recuit a basse temperature des echantillons riches en oxygene, on a remarque que des domaines ordonnes d'un super-reseau tetragonal s'y forment et croissent dans la matrice cubique. On propose un diagramme de phase partiel, qui indique les limites de stabilite de la phase ordonnee et qui est base sur des traitements thermiques isothermes. Pour toutes les trois orientations cubiques de l'axe tetragonal c du domaine, on a trouve des sous-domaines d'un super-reseau tetragonal a grande maille elementaire, qui existaient en deux orientations voisines. Nous avons etabli le reseau reciproque, et done la structure du super-reseau, par diffraction electronique combinee avec la methode d'images a champ sombre. Le contenu de la maille elementaire est V244O320 et elle contient 20 atomes interstitiels de V, tetraedriquement coordonnes, ainsi que 96 places vacantes.

Studies on energy-linked reactions. Energy-linked transhydrogenase reaction in Escherichia coli.

Abstract: 1. Small particles from Escherichia coli catalyse an ATP-dependent reduction of NADP+ by NADH. 2. The reaction was stimulated by Mg2+ and only ATP and ITP could serve as energy donors. 3. Studies of the stoicheiometry of the reaction indicate that 1–2mol of ATP are utilized/mol of NADH produced. 4. The reaction is inhibited by uncoupling agents such as 2,4-dinitrophenol (200μm) and tetrachlorotrifluorobenzimidazole (2μm) but oligomycin does not inhibit. 5. The reaction is inhibited by relatively high concentrations (200μm) of piericidin A.

The War Emergency Workers’ National Committee, 1914–1920

Abstract: The War Emergency Workers’ National Committee is generally remembered only for the ironic circumstances associated with its formation. It arose from a conference summoned by Arthur Henderson, who hoped to supply a united proletarian response to the threat of war. Acting on behalf of the Labour Party, Henderson sent out invitations to the principal institutions of organised labour and to a large number of prominent personalities in the trade-union and socialist world. When the conference met on 5 August 1914, the United Kingdom had already declared war on Germany. The meeting wasted no time reflecting upon its original purpose: it spared no thought for the implications of the Stuttgart Resolution of the Second International. It rather addressed itself to the matter in hand, resolving to establish a committee which would be responsible for safeguarding working-class interests during the ‘Emergency’. And it stuck to its last.

Magnetohydrodynamic duct flow in a uniform transverse magnetic field of arbitrary orientation

Abstract: The paper presents an approximate analysis for high Hartmann number of the flow of an electrically conducting, incompressible fluid in a duct of square crosssection, having one pair of opposite walls insulating, and the other pair perfectly conducting and inclined at arbitrary orientation to a uniform transverse magnetic field. The flow is considered to be either pressure-driven with the two perfectly conducting electrodes short-circuited together or electrically driven by a potential difference applied between these electrodes in the absence of axial pressure gradient. The paper describes experiments on the pressure-driven, short circuited case using mercury in copper ducts to investigate the variation of the streamwise pressure gradient and of the potential distribution along one insulating wall with orientation, magnetic field and flow rate.At general orientations the analysis suggests and the experiments confirm the existence of regions of stationary fluid in the corners of the duct, together with viscous shear layers parallel to the magnetic field. For the case in which the electrodes are parallel to the magnetic field the experimental results for the pressure gradient, but not those for the potential distribution, agree reasonably well with Hunt & Stewartson's (1965) asymptotic solution. Both pressure gradient and potential results agree closely with the analysis by Hunt (1965) of the case in which the electrodes are perpendicular to the magnetic field.

Sylow subgroups of locally finite groups

Abstract: The theorems of Sylow are among the most basic in the theory of finite groups, and Hall’s theorems on the existence and conjugacy of Hall π-subgroups occupy a similarly central position in the theory of finite soluble groups. It is therefore natural to ask for what kinds of infinite groups results like them are true, and to what extent other parts of finite group theory can be extended to such groups. The answer to the first question has probably turned out to be more disappointing than was at one time expected, in that it is only under rather severe restrictions that sensible analogues of Sylow’s and Hall’s theorems can be obtained; but this paradoxically rekindles interest in the question in that one may now hope for a reasonably complete classification of the circumstances under which theorems like Sylow’s and Hall’s are true. As regards the second question, there are nevertheless some interesting classes of groups with very civilized Sylow structure, and quite a lot of progress has been made in extending such things as formation theory to these groups. I want mainly to discuss the first question from the classification point of view, but first some background may be of interest.

Distribution of carbon dioxide and oxygen in the gas phase of aerobic soils

Abstract: Summary It is shown that, under certain conditions, the increase in carbon dioxide partial pressure is proportional to the drop in oxygen partial pressure in the gas phase in fallow soils. The principal assumptions are that respiration is unaffected by lowering of oxygen partial pressure until very low levels are reached, and that the respiration quotient is constant. Previously reported measurements of the composition of gases extracted from soil are consistent with the theory.

The Concept of Housing Class and the Sociology of Race Relations

Abstract: JOHN REX is Professor of Sociology at the University of Warwick. Race relations is an area of interdisciplinary study and it is to be expected that students from different disciplines will have sometimes complementary, sometimes conflicting insights into particular problems. Nonetheless this does not mean that there are no distinct disciplinary ways of posing and looking at problems. Still less does it mean that complex concepts can be elucidated, or theories tested and refuted by simplistic and sub-disciplinary survey methods. It was with this in mind that I introduced into an empirical study of race relations in the urban zone of transition in Birmingham the sociological concept of ’housing classes’. I take sociology to be concerned with the ways in which the behaviour of individuals is affected by their participation in more or less fixed and more or less fluid and changing structures of social relations. It is concerned with those influences on behaviour arising from ’outside’ the individual rather than those which arise ’internally’, ’in his head’ or ’from the personality system’. Thus, while psychologists may be interested in the question of whether a certain kind of personality system is associated with racially prejudiced beliefs and behaviour, the sociologist will be concerned with whether such beliefs and behaviour are meaningfully and perhaps causally connected with being involved in a network of social relations and

Studies on the supply of oxygen to the roots of mustard seedlings (sinapis alba l.)

Abstract: Summary Most of the requirements of roots for oxygen were met by oxygen from the air entering the leaves and travelling through the plants to the roots in oxygen-free media. The amount of oxygen supplied in this way decreased proportionately with rise in oxygen partial pressure at the root surface. Although roots offered a considerable barrier to the passage of oxygen out of them, experiments in which transport from the aerial parts was prevented indicated that the roots could obtain almost all the oxygen they required from the surrounding media provided the oxygen partial pressure at the root surface exceeded the low value of 0.05 atmospheres. These results were obtained by means of a new experimental technique which enabled the effect of oxygen partial pressure at the root surfaces on oxygen uptake and root elongation to be studied. It was based on circulating a small volume of nutrient solution around roots in a gas-free enclosed system sufficiently rapidly for the partial pressure in the solution to be almost the same as at the root surfaces.