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Showing papers by "University of Reading published in 1983"


Journal ArticleDOI
TL;DR: In this article, an extension of the Eliassen-palm flux concept to the time-averaged three space dimension problem is presented. But the authors focus on the behavior of the large-scale eddies themselves, not only the shape and propagation of the eddies, but also their feedback on the mean flow.
Abstract: In investigations concerned with obtaining an understanding of the general circulation of the atmosphere, the determination of the role of the large-scale eddies presents a special problem. In the present study,attention is given to a theory which, in some ways, provides an extension of the Eliassen-Palm flux concept so that it can be applied in particular to the time-averaged three space dimension problem. Particular emphasis is given to the understanding of the feedback of the eddies onto the mean flow. However, the behavior of the eddies themselves is also discussed. It is shown that, in simple situations, the anisotropic eddy horizontal velocity correlation tensor implies the shape and propagation of eddies and the feedback of the eddies onto the mean flow.

727 citations


Journal ArticleDOI
TL;DR: The fine to very coarse sandstones, gravelly sandstones and intraformational conglomerates of the mid to upper Brownstones are excellently exposed in large fresh road cuttings near Ross-on-Wye in the southern Welsh Borders.

549 citations


Journal ArticleDOI
01 Jan 1983
TL;DR: Explicit formulae have been developed for the stresses beneath a sliding, normally loaded Hertzian contact as mentioned in this paper, and as friction rises a region of impending failure develops in the back edge of contact.
Abstract: Explicit formulae have been developed for the stresses beneath a sliding, normally loaded Hertzian contact. As friction rises a region of impending failure develops in the back edge of contact.

458 citations


Journal ArticleDOI
TL;DR: A model is presented for the analysis of lifetime data in which the rates of mortality for separate groups of patients converge with time, and a non-parametric estimate is given for the survivor function.
Abstract: A model is presented for the analysis of lifetime data in which the rates of mortality for separate groups of patients converge with time. A non-parametric estimate is given for the survivor function. The theoretical basis for the model assumes that prognostic factors have a multiplicative effect on the odds against survival beyond any given time. The model is fitted to data using maximum likelihood estimation, and an example of its use in the analysis of a lung cancer trial is given.

430 citations



Journal ArticleDOI

230 citations


Journal ArticleDOI
TL;DR: The proteolytic systems of lactic acid bacteria are described in relation to their growth and their functions in protein-rich foods and their role in the manufacture of milk products is discussed.
Abstract: The proteolytic systems of lactic acid bacteria are important as a means of making protein and peptide N available for growth and as part of the curing or maturation processes which give foods their characteristic rheological and organoleptic properties. The proteolytic systems of lactic acid bacteria are described in relation to their growth and their functions in protein-rich foods. Their role in the manufacture of milk products is discussed.

199 citations


Book ChapterDOI
01 Jan 1983
TL;DR: This chapter provides a general understanding of metal ion involvement in the various physiological compartments of the mollusk.
Abstract: Publisher Summary This chapter provides a general understanding of metal ion involvement in the various physiological compartments of the mollusk. Five elements—potassium, sodium, magnesium, calcium, and chlorine—are involved in establishing the ionic composition of the intracellular and extracellular fluids. These elements are also manipulated by cells so as to produce the osmotic equilibria that are necessary for living systems. There is a large group of elements that are required in only trace amounts for a whole variety of metabolic activities. Many of these elements are metals and they perform a wide variety of functions of which the activity of metalloenzymes, the transport of oxygen, and redox activities are the best understood. A large number of metalloenzymes and metal ion-activated enzymes are now known. Some metals, such as zinc and magnesium, are frequently associated with enzymes, although they may not be structurally a part of the molecule. A second major group of metal-dependent functions involves the respiratory pigments.

159 citations


Journal ArticleDOI
TL;DR: A model which defines fitness in terms of the intrinsic rate of increase of phenotypes is used to analyse which life cycles are appropriate to which ecological circumstances and the predictions are made for asexual animals and those sexual animals producing on average more than one daughter per brood.

155 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used tube solarimeters placed horizontally above and below the canopy of a potato crop to measure the amount of energy intercepted by the leaf surface and the efficiency of its use.
Abstract: Since Monteith (1977) proposed that growth can be analysed in terms of the amount of energy intercepted by the leaf surface and the efficiency of its use, there has been much interest in the measurement of light interception in potato crops (Scott & Wilcockson, 1978; Milford et al. 1980; Allen & Scott, 1980). This can be measured directly using tube solarimeters placed horizontally above and below the canopy. However, this method suffers from three major drawbacks: (a) in an experiment with many plots it becomes expensive in terms of equipment, (b) a single solarimeter samples only a very small part of the plot canopy, and (c) the solarimeter cannot distinguish between living leaves and other material. Thus, when the crop lodges and/or starts to senesce, visual observations suggest that the area over the solarimeter may not be representative of the plot as a whole.

138 citations


Journal ArticleDOI
TL;DR: The Atmospheric Lifetime Experiment (ALO) as mentioned in this paper was designed to determine accurately the atmospheric concentrations of the four halocarbons CFCl3, CF2Cl2, CCl4, and CH3CCl3 with emphasis on measurement of their longterm trends in the atmosphere.
Abstract: The Atmospheric Lifetime Experiment is designed to determine accurately the atmospheric concentrations of the four halocarbons CFCl3, CF2Cl2, CCl4, and CH3CCl3, and also of N2O with emphasis on measurement of their long-term trends in the atmosphere. Comparison of these concentrations and trends for the four halocarbons with estimates of their industrial emission rates then enables calculations of their global circulation rates and globally averaged atmospheric lifetimes. The experiment utilizes automated dual-column electron-capture gas chromatographs which sample the background air about 4 times daily at the following globally distributed sites: Adrigole, Ireland, Cape Meares, Oregon; Ragged Point, Barbados; Point Matatula, American Samoa, and Cape Grim, Tasmania. The climatology of these 'clean air' sites and their ability to describe the global air mass are reviewed. The instrumentation and methods for data acquisition and processing are then described. An overview of the data obtained and the trends derived during the 3-year period from July 1978 through June 1981 for each of the five species being measured is presented.

Journal ArticleDOI
TL;DR: In this paper, the antioxidant properties of polyhydroxy flavonoids and related compounds have been evaluated and the results have been correlated with the structures of the compounds concerned, which have been shown to function mainly as primary antioxidants.

Journal ArticleDOI
TL;DR: The problems of esterase classification are discussed and some ideas presented to clarify the present confused state of the classification systems.

Journal ArticleDOI
TL;DR: In this article, a series of 11 polyhydroxy chalcones, and in 4 cases, flavanones derived from them by isomerisation, have been shown to be potent antioxidants for lard.


Journal ArticleDOI
TL;DR: A tear test was found to be suitable for determining the fracture toughness of two extensible connective tissues: rat skin and the mesogloea of the sea anemone Metridium senile.
Abstract: A tear test was found to be suitable for determining the fracture toughness of two extensible connective tissues: rat skin and the mesogloea of the sea anemone Metridium senile. This technique allows the mapping of toughness variations over an area of rat skin. The toughness bears an inverse relationship to maximum stiffness parallel to the direction of crack propagation. Toughness of rat skin increases slightly with increasing extension rate.

Book ChapterDOI
01 Jan 1983
TL;DR: Stereotypy is a relatively invariate sequence of movements occurring so frequently, in a particular context, that it could not be considered to form part of one of the normal functional systems of the animal.
Abstract: Stereotyped movements form part of the normal behavioural repertoire of animals but a definition for welfare purposes is: a stereotypy is a relatively invariate sequence of movements occurring so frequently, in a particular context, that it could not be considered to form part of one of the normal functional systems of the animal. Stereotypies may sometimes be the result of malfunctions of systems controlling behaviour but they could be used to control motivational state by increasing sensory input in monotonous surroundings or by increasing the average predictability of input in unpredictable surroundings. Their frequency of occurrence should be assessed both in the normal rearing conditions and when there is human disturbance. The effects of stereotypies on the animal’s body and on the pen can also be assessed. Examples of studies where rearing condition changes have reduced the incidence of stereotypies are quoted. Whatever the function of stereotypies, if they occupy much time, say 10% of waking life, the conditions could be said to be bad for the welfare of the animal. Stereotypy incidence, however, is just one of several measures which must be combined when assessing responses to adversity.

Journal ArticleDOI
TL;DR: The tunica media and intima of descending thoracic aortas from commercially killed pigs showed variations in mechanical properties along their length in a region extending from just in front of the first inter costal artery to the sixth intercostal artery, positively correlated with an increase in collagen mass fraction and an increase of radius/thickness ratio away from the heart.


Journal ArticleDOI
TL;DR: In this paper, a general form of the location model is considered for mixed continuous and categorical variables observed in a number of different populations, and some special cases of practical interest are cited.
Abstract: SUMMARY A general form of the location model is considered for mixed continuous and categorical variables observed in a number of different populations, and some special cases of practical interest are cited. The distance between any two populations is derived for each of these models. Estimation of parameters in these distance measures is discussed, and the methods are illustrated by application to previously published data.

Journal ArticleDOI
TL;DR: A comparative study of the ecology of Callosobruchus analis, C. rhodesianus and the Malawi strain of C. maculatus, and the distribution of the two species in Africa, found total oviposition was highest at 30°C for all species, but survival from egg to adult was high at 25°C.

Journal ArticleDOI
TL;DR: The static lattice relaxation calculation presented in this paper predicts a restructured stable [001] twist boundary in NiO. This is in contrast with experiment in which twist grain boundaries have been observed in MgO.
Abstract: Recent calculations on coincidence twist grain boundaries in oxides with the rocksalt structure have shown that the interfaces are only weakly bound. This is in contrast with experiment in which twist grain boundaries have been observed in MgO. The static lattice relaxation calculation presented here predicts a restructured stable [001] twist boundary in NiO. The results are equally applicable to the other oxides with the same structure.

Journal ArticleDOI
TL;DR: In this article, the NH 2 -inversion levels in the A 1 B 2 State of aniline-NH 2 and -ND 2 have been improved using new information regarding

Journal ArticleDOI
TL;DR: A case can be made for more detailed investigation of comparative detoxication mechanisms in birds and other vertebrates to aid the explanation and the prediction of patterns of selective toxicity.


Journal ArticleDOI
TL;DR: In this article, the authors proposed a theory of supply and demand in the land market, and incorporated it into land market theory to explain or predict that urban sprawl will occur, in the absence of planning controls, a development gains tax will slow down the rate of development of land and increase its price.
Abstract: Received theories of the land market are inadequate, since they ignore the supply of land. It is known that occupiers of land are usually unwilling to sell at the market price but require compensation for being forced to move. Incorporating this as a theory of supply into land market theory allows us to explain or predict that (a) urban sprawl will occur, in the absence of planning controls, (b) a development gains tax will slow down the rate of development of land and increase its price, (c) whether land is owner occupied or occupied by tenants will affect its development, and (d) powers of compulsory purchase may be necessary for certain kinds of development but may cause social costs.

Journal ArticleDOI
TL;DR: In this paper, the authors examine the forces that affect growth, location, and distribution in the service sector and examine the specific context of location choices made by offices of multinational enterprises (MNEs).
Abstract: The forces that affect growth, location, and distribution in the service sector will have elements in common with those at work in manufacturing, but equally will exhibit certain unique features. This paper examines such forces in the specific context of location choices made by offices of multinational enterprises (MNEs). Such enterprises emerge in response to particular market imperfections and to exploit particular ‘ownership specific’ advantages. The nature of such ownership specific advantages is discussed with specific reference to MNE office location, and tested using data drawn from a survey of European offices of mainly US-based MNEs. It is shown that a distinction must be drawn between offices that provide a service for final consumption and those that provide a mainly coordinating role. The former types of office are shown to be heavily market oriented and to act in ways consistent with theory. The latter types of office are more complex, but again locate in ways consistent with theory; in part...


Journal ArticleDOI
TL;DR: A series of symmetric tilt grain boundaries in nickel oxide has been studied using a static-lattice atomistic simulation method in this paper, where the energy as a function of misorientation angle shows a deep cusp at the (1I1) interface (70·5°) which corresponds to a coherent twin structure.
Abstract: A series of 〈011〉 symmetric tilt grain boundaries in nickel oxide has been studied using a static-lattice atomistic simulation method. The energy as a function of misorientation angle shows a deep cusp at the (1I1) interface (70·5°) which corresponds to a coherent twin structure. The lower angle orientations (1I1), (12) and (133) have relatively close-packed structures, while the higher-angle (2I1), (3I1) and (4I1) orientations contain arrays of open pipes in the boundary. These are analogous to the structures found for the (001) grain boundaries and may be responsible for the enhanced, anisotropic diffusion properties.

Journal ArticleDOI