Showing papers by "University of Reading published in 1985"
TL;DR: The authors provide a translation of the philosophical works of Descartes, based on the best available Latin and French texts, which is intended to replace the only reasonably comprehensive selection of his works in English, by Haldane and Ross, first published in 1911.
Abstract: These two volumes provide a translation of the philosophical works of Descartes, based on the best available Latin and French texts. They are intended to replace the only reasonably comprehensive selection of his works in English, by Haldane and Ross, first published in 1911. All the works included in that edition are translated here, together with a number of additional texts crucial for an understanding of Cartesian philosophy, including important material from Descartes' scientific writings. The result should meet the widespread demand for an accurate and authoritative edition of Descartes' philosophical writings in clear and readable modern English.
1,665 citations
TL;DR: In this paper, the authors presented coarse spatial resolution, high temporal frequency satellite data from the NOAA/AVHRR system to demonstrate their utility for monitoring vegetation seasonal dynamics, including forest clearance in Brazil, the productivity of African grasslands, Indian tropical forest and Chinese agriculture.
Abstract: Coarse spatial resolution, high temporal frequency satellite data from the NOAA/AVHRR system are presented to demonstrate their utility for monitoring vegetation seasonal dynamics. The techniques for processing and analysing the data are outlined and examples are given for selected applications at a range of scales. Normalized difference vegetation index images are presented for the entire globe and for the continents of Africa, South America and south-east Asia, with descriptions of the seasonal dynamics of major vegetation formations as portrayed by the transformed AVHRR data. Monitoring of forest clearance in Brazil, the productivity of African grasslands, Indian tropical forest and Chinese agriculture are selected for discussion. The paper concludes that coarse-resolution satellite data provide a valuable tool for vegetation mapping and monitoring at regional and global scales.
1,125 citations
TL;DR: Data from the advanced very-high-resolution radiometer sensor on the National Oceanic and Atmospheric Administration's operational series of meteorological satellites were used to classify land cover and monitor vegetation dynamics for Africa over a 19-month period.
Abstract: Data from the advanced very-high-resolution radiometer sensor on the National Oceanic and Atmospheric Administration's operational series of meteorological satellites were used to classify land cover and monitor vegetation dynamics for Africa over a 19-month period There was a correspondence between seasonal variations in the density and extent of green-leaf vegetation and the patterns of rainfall associated with the movement of the Intertropical Convergence Zone Regional variations, such as the 1983 drought in the Sahel of westem Africa, were observed Integration of the weekly satellite data with respect to time for a 12-month period produced a remotely sensed estimate of primary production based upon the density and duration of green-leaf biomass Eight of the 21-day composited data sets covering an 11-month period were used to produce a general land-cover classification that corresponded well with those of existing maps
1,060 citations
TL;DR: Numerical methods are described for determining robust, or well-conditioned, solutions to the problem of pole assignment by state feedback such that the sensitivity of the assigned poles to perturbations in the system and gain matrices is minimized.
Abstract: Numerical methods are described for determining robust, or well-conditioned, solutions to the problem of pole assignment by state feedback. The solutions obtained are such that the sensitivity of the assigned poles to perturbations in the system and gain matrices is minimized. It is shown that for these solutions, upper bounds on the norm of the feedback matrix and on the transient response are also minimized and a lower bound on the stability margin is maximized. A measure is derived which indicates the optimal conditioning that may be expected for a particular system with a given set of closed-loop poles, and hence the suitability of the given poles for assignment.
1,035 citations
411 citations
TL;DR: In this article, a simple model for the effective vibrational hamiltonian of the XH stretching vibrations in H2O, NH3 and CH4 is considered, based on a morse potential function for the bond stretches plus potential and kinetic energy coupling between pairs of bond oscillators.
Abstract: A simple model for the effective vibrational hamiltonian of the XH stretching vibrations in H2O, NH3 and CH4 is considered, based on a morse potential function for the bond stretches plus potential and kinetic energy coupling between pairs of bond oscillators. It is shown that this model can be set up as a matrix in local mode basis functions, or as a matrix in normal mode basis functions, leading to identical results. The energy levels obtained exhibit normal mode patterns at low vibrational excitation, and local mode patterns at high excitation. When the hamiltonian is set up in the normal mode basis it is shown that Darling-Dennison resonances must be included, and simple relations are found to exist between the xrs , gtt , and Krrss anharmonic constants (where the Darling-Dennison coefficients are denoted K) due to their contributions from morse anharmonicity in the bond stretches. The importance of the Darling-Dennison resonances is stressed. The relationship of the two alternative representations of...
384 citations
TL;DR: In this article, principal components of two LANDSAT MSS subscenes were separately calculated using both unstandardized and standardized variables, and the results indicate substantial improvement in signal-to-noise ratio and image enhancement by using standardized variables in the principal components analysis.
Abstract: In remote sensing, principal components analysis is usually performed using unstandardized variables. However, the use of standardized variables yields significantly different results. In this paper principal components of two LANDSAT MSS subscenes were separately calculated using both methods. The result indicate substantial improvement in signal-to-noise ratio and image enhancement by using standardized variables in the principal components analysis.
353 citations
TL;DR: In this article, principal components analysis of multitemporal data derived from NOAA world data product is performed by means of principal component analysis in order to examine their underlying multi-dimensional dimensionality.
Abstract: Two sets of multitemporal data derived from NOAA world data product are analyzed by means of principal components analysis in order to examine their underlying multitemporal dimensionality. Specifically, images of the normalized difference vegetation index (NDVI) were analyzed for eight 3-week periods for Africa and ten 3-week periods for North America sampled from throughout the year extending from April 1982 to March 1983. The two multitemporal sets of images displayed remarkable similarities in terms of their first two components, the first corresponding very closely to the annualized integrated NDVI and the second to the seasonality of the NDVI. In particular, for the African data set the feature space defined by the first two components allows separation of the main cover types.
164 citations
TL;DR: In the case of solid body rotation, the eddy activity spreads more or less uniformly over the sphere as discussed by the authors, and the mean flow is accelerated in the region in which the initial wave activity is large, while the compensating deceleration determined by the dissipation of wave activity occurs over a wide range of latitudes.
Abstract: Publisher Summary This chapter describes the large-scale eddies and the general circulation of the troposphere. Analyses of observations and general circulation models are evolving rapidly and complementing each other as they focus on the most dynamically interesting budgets and statistics. In the case of solid body rotation, the eddy activity spreads more or less uniformly over the sphere. The mean flow is accelerated in the region in which the initial wave activity is large, while the compensating deceleration determined by the dissipation of wave activity occurs over a wide range of latitudes. The natural procedure for constructing the analogous neutralized state in a continuously stratified atmosphere is to satisfy the Charney-Stern criterion by destroying the temperature gradient at the surface and by destroying the potential vorticity gradient in a layer adjacent to the surface. Upstream of the vorticity centers the low-level equatorward flow of cold continental air and the poleward flow of moist subtropical air have a frontogenetic effect, increasing the low-level baroclinicity in the storm track. It is suggested that the developing cross-fertilization among theory, numerical general circulation modeling, and observational studies will result in rapid advances in understanding of the large-scale flow in the atmosphere.
159 citations
TL;DR: It is concluded that the three sesquiterpene lactones secreted in the latex provide a significant barrier to herbivory in chicory, although the phenolics and notably cichoriin also protect the plant from insect feeding.
159 citations
TL;DR: Melting experiments on a mantle-derived nodule assemblage consisting of clinopyroxene, phlogopite and minor titanomagnetite, sphene and apatite have been done at 20 and 30 kbar between 1,175 and 1,300° C as mentioned in this paper.
Abstract: Melting experiments on a mantle-derived nodule assemblage consisting of clinopyroxene, phlogopite and minor titanomagnetite, sphene and apatite have been done at 20 and 30 kbar between 1,175 and 1,300° C. The nodule composition was selected on the basis of modal and chemical analyses of 84 mantle derived nodules with metasomatic textures from the Katwe-Kikorongo and Bunyaruguru volcanic fields of south-west Uganda. At 30 kbar, 1,225 and 1,250° C, representing 20–30% partial melting, the compositions of glasses compare favourably to those of the average composition of 26 high potassic mafic lavas from the same region. Glasses produced by sufficiently low degrees of partial melting at 20 kbar could not be analysed. Glass compositions obtained for 20–30% melting at 30 kbar have high K2O (3.07–5.05 wt.%), low SiO2 (35.0–39.2 wt.%), high K/K + Na (0.54–0.71), K + Na/Al (0.99–1.08) and Mg/ Mg + FeT of 0.59–0.62. These results support the suggestion of Lloyd and Bailey (1975) that the nodules represent the source material for the high K-rich lavas of south-west Uganda. If this conclusion is correct it implies that anomalous mantle source of phlogopite clinopyroxenite composition could produced the Ugandan lavas by relatively higher degrees of partial melting than that normally considered for highly alkaline mafic magmas derived from a pyrolitic mantle source. Higher degrees of melting are considered likely from such a different source region, rich in alkalis, water and radioactive elements. Steeper geotherms and increased fluxing of sub-rift mantle by degassing would also produce higher degrees of partial melting.
TL;DR: In this article, a two-dimensional semigeostrophic theory is used to solve the deformation-forced frontogenesis problem for a circumstance in which the stability to moist slantwise convection is small but positive.
Abstract: It is often observed that, despite the existence of near neutrality to slantwise convection, rainbands and snowbands can persist for long periods with narrow intense updrafts producing large quantities of precipitation in many cases. This is probably due to the presence of active frontogenesis which, as shown here, maintains such structures. In order to investigate this process, we use two-dimensional semigeostrophic theory to solve the deformation-forced frontogenesis problem for a circumstance in which the stability to moist slantwise convection is small but positive. In this case, numerical simulation is necessary to determine the evolution of the front. Several previous studies have described the role of diabatic forcing in modifying the cross-frontal circulation by use of the Sawyer-Eliassen equation. In particular, analytic solutions of that equation for the case of small moist symmetric stability show that a narrow updraft should occur ahead of the maximum geostrophic frontogenesis. Numeri...
TL;DR: Models which define fitness in terms of per capita rate of increase of phenotypes are used to analyse patterns of individual growth and it is shown that sigmoid growth curves are an optimal strategy.
TL;DR: In this article, the authors investigated the lamellar morphology of melt-crystallized isotactic polystyrene and found that hexagonal lamellae splay apart about a common diagonal presenting three characteristic projections in orthogonal directions.
TL;DR: In this article, the authors compared the properties of milks fermented with commercially available kefir grains compared with similar characteristics of heat treated (90 ΰC/30 min) milks that had been fermented with aroma producing starters in addition to the kefIR grains.
Abstract: Flavour, aroma and appearance of milks fermented with commercially available kefir grains were compared with similar characteristics of heat treated (90 ΰC/30 min) milks that had been fermented with aroma producing starters in addition to the kefir grains. The starters used were either a mixture of Streptococcus lactis subsp. diacetilactis and Leuconostoc cremoris (lactic culture) or of Str. thermophilus and Lactobacillus bulgaricus (yogurt culture).Two methods of fermentation were investigated involving removal of the grains followed by (i) a second fermentation of the kefir with the aroma-producing organisms and (ii) combining the kefir with aroma-producing organisms for use as a starter to ferment a further sample of heat-treated milk. Products were assessed by a taste panel and marked for acceptability. Addition of lactic or yogurt cultures resulted in products with increased mean scores for aroma and more acceptable flavours.
TL;DR: It is suggested that smoking has speeded up stimulus evaluation processes in these individuals and is consistent with the common self-report by smokers that smoking aids concentration.
TL;DR: In this paper, a set of equations with which to describe tropical cyclones in gradient wind balance involves using the total flow for advection and a method for the integration of this equation set is described and is shown to be analogous to the semigeostrophic case.
Abstract: A useful set of equations with which to describe tropical cyclones in gradient wind balance involves using the total flow for advection. Transformation of these equations to angular momentum coordinates has advantages including simplification of the advection terms and -stretching of regions of large vorticity. The resulting equation set is a generalization of the two-dimensional semigeostrophic approximation to curved flows. A method for the integration of this equation set is described in this paper and is shown to be analogous to the semigeostrophic case. The potential vorticity equation plays a central role and in the presence of diabatic sources and sinks a large variation in potential vorticity across the vortex will develop. The equation set can be integrated in time once a convective parameterization scheme is specified linking the diabatic term to the explicit motion. The structure of balanced vortices is described for plausible boundary variations of potential temperature and interior v...
TL;DR: The diet dilution technique overcomes the major disadvantage of the graded supplementation method for determining the requirements of amino acids, namely that of the amino acid balance changing systematically in successive dietary treatments.
Abstract: 1. Three experiments were conducted on male broiler chickens between one and three weeks of age to determine their response to dietary lysine concentrations. 2. Serial dilutions of a summit diet shown to be first‐limiting in lysine were fed in all experiments. The balance between amino acids in these diets was maintained within narrow limits. 3. Intake of the most‐limiting amino acid was the most important factor determining growth rate; protein intake as such was of little or no importance. 4. The efficiency of utilisation of dietary lysine for protein growth was calculated to be 65–05 mg/g protein gain, representing a net efficiency of 0–85. 5. The diet dilution technique overcomes the major disadvantage of the graded supplementation method for determining the requirements of amino acids, namely that of the amino acid balance changing systematically in successive dietary treatments.
TL;DR: It is suggested that over a wide range of conditions (covering the photothermal regimes experienced by lentil crops world-wide), time to flowering can be described by the equation 1/f = a + bt + cp where a, b and c are constants which differ between genotypes and the values of which provide a sound basis for screening germplasm for sensitivity to temperature and photoperiod.
TL;DR: In this paper, the authors evaluate a 850 mb and a 150 mb budget, with attention particuliere portee sur le second niveau qui voisine avec celui de l'ecoulement maximum de sortie, associe a la convection profonde organisee dans la zone tropicale.
Abstract: Les budgets sont evalues a 850 mb et a 150 mb, avec attention particuliere portee sur le second niveau qui voisine avec celui de l'ecoulement maximum de sortie, associe a la convection profonde organisee dans la zone tropicale. On trouve que les balances aux deux niveaux consideres, different qualitativement: a 850 mb, l'ecoulement zonal est faible et la vorticite relative et son gradient sont petits compares avec le parametre, et son gradient, de Coriolis; la balance de vorticite est alors essentiellement une balance de Sverdrup, entre l'etirement et l'advection horizontale de vorticite planetaire, ce qui fait qu'une hypothese de linearite par rapport a un etat au repos serait valable; a 150 mb, le tableau change completement: la balance est essentiellement non lineaire et presque non visqueuse; ce caractere non lineaire de la dynamique dans la troposphere superieure est rehaussee par le fait qu'un modele barotrope linearise autour de l'ecoulement zonal, permanent, observe, est incapable de simuler correctement les anomalies d'ecoulement au-dessus du Pacifique central. A noter que la source de chaleur atmospherique associee au degagement de chaleur latente, au-dessus de l'anomalie de temperature de surface marine, dans le Pacifique central, presente des fluctuations basses frequences. L'origine de cette variabilite reste encore inexpliquee
TL;DR: In this article, numerical models were used to simulate the combined tidal and surge response on 3 June 1982 along the Orissa coast of India when the landfall of a tropical cyclone led to severe inland flooding.
Abstract: Numerical models are described for the evaluation of the interaction between tide and surge in the Bay of Bengal. The models are used to simulate the combined tidal and surge response on 3 June 1982 along the Orissa coast of India when the landfall of a tropical cyclone led to severe inland flooding. This is one of the few events for which a reliable tide-gauge reading is available and this enables a direct comparison to be made between the model predictions and the observationally determined sea-surface elevation anomaly. The comparison, although only utilizing limited observational data, appears sufficiently good for us to assert that the principal features of the surge response are correctly reproduced. A model simulation is also made of the surge that occurred along the Andhra coast of India during the period 18—20 November 1977 when there was heavy coastal inundation. Although tide-gauge readings are not available for this event, the predicted surge response agrees well with indirect estimates of the maximum sea-surface level and eyewitness accounts of inland flooding. The principal requirement for the operational use of these models is the availability of accurate data on the surface wind field together with a reliable forecast of the track to be followed by the tropical cyclone.
TL;DR: It is suggested that the photo-thermal response of flowering in chickpeas, over the range of environments normally experienced by the crop, may be described by the equation 1/f = a + bt + cp in which f is the number of days from sowing to first flower, t is mean temperature and p is photoperiod.
TL;DR: In this article, a commercial neutral proteinase was encapsulated in liposomes (multilamellar) and incorporated into cheese curd via the cheese milk, which was protected from proteinase attack during curd manufacture.
Abstract: A commercial neutral proteinase was encapsulated in liposomes (multilamellar) and incorporated into cheese curd via the cheese milk. The milk proteins were protected from proteinase attack during curd manufacture. A significant proportion of the liposome-entrapped enzyme was retained in the curd and its subsequent release into the cheese matrix was inferred from an increased rate of β-casein breakdown.
TL;DR: In this article, a simple schema simple for determining the gradients a partir de l'approximation a elements finis triangulaires lineaire par morceaux de la solution d'un probleme elliptique du second ordre.
Abstract: On justifie l'utilisation d'un schema simple pour determiner les gradients a partir de l'approximation a elements finis triangulaires lineaire par morceaux de la solution d'un probleme elliptique du second ordre. Le gradient obtenu est une estimation superconvergente du vrai gradient
TL;DR: The ratio of stearic to oleic acid showed a dose response effect, with an increase inStearic acid content as the dose of cyclopropene fatty acid increased, and a corresponding reduction in oleoic acid, which was not affected to the same extent.
Abstract: The effect of cyclopropene fatty acids, sterculic and malvalic, on the lipids of yeasts grown under nitrogen limiting, lipid accumulating, conditions was studied. The ratio of stearic to oleic acid showed a dose response effect, with an increase in stearic acid content as the dose of cyclopropene fatty acid increased, and a corresponding reduction in oleic acid. Linoleic and linolenic acids were not affected to the same extent. These effects are shown for the yeasts Candida sp. 107, Trichosporon cutaneum, and Rhodosporidium toruloides.
TL;DR: In this article, two rainfall series for the Sahel region of West Africa have been updated to 1983, and the annual and monthly series are presented and analyzed. And it is suggested that agricultural planning should be based on rainfall records for the last twenty years.
Abstract: Two rainfall series for the Sahel region of West Africa have been updated to 1983. Annual and monthly series are presented and analysed. Relatively dry conditions have persisted in this region since 1968 due mainly to a decline in rainfall during August, the wettest month. Drought has probably been less severe in this region during the late rather than the early 1970s because of better rainfall early in the season. It is suggested that agricultural planning should be based on rainfall records for the last twenty years.
TL;DR: In this article, the home range of a common marmoset, Callithrix jacchus, was investigated using both observation and radiolocation, and the results showed that the home ranges were small compared to those of other callitrichids.
Abstract: Data were obtained both from observation and by radiolocation on the size and use of the home range of the common marmoset, Callithrix jacchus jacchus.Ranges were small compared to those of other callitrichids, varying between 0.72 to 1.62 ha, and a high proportion of the home range was used each day. The marmosets showed territorial behavior, defending an area almost equivalent to the home range. Despite this, mating between animals belonging to neighboring groups was seen. Correlations between the use of the home range and some environmental variables showed little consistency between two groups which occupied ranges of differing resource density, and their activity patterns, as measured by movement through their ranges, were also different. Possible reasons for these inconsistencies are discussed.
TL;DR: Using sheep and human serum the relationship between centrifugation time and yield of total lipoprotein, HDL-cholesterol and "A"-esterase in lipop protein was studied employing different centrifuge rotors, providing further evidence that serum "A-esterase activity is associated with different species of HDL-particle.
Abstract: 1. 1. Using sheep and human serum the relationship between centrifugation time and yield of total lipoprotein, HDL-cholesterol and “A”-esterase in lipoprotein was studied employing different centrifuge rotors. 2. 2. More rapid separation of these components was obtained with a vertical rotor than with an angled rotor. The procedures commonly employed for lipoprotein separation gave low yields of lipoprotein “A”-esterase and HDL-cholesterol. 3. 3. The separation of sheep serum “A”-esterase into the lipoprotein fraction was not in phase with that of HDL-cholesterol and the pattern of separation was different from that in human serum. 4. 4. These results provide further evidence that serum “A”-esterase activity is associated with different species of HDL-particle.
TL;DR: It is known that the union of edge-disjoint 1-factors conjecture is true for d(G) equal to 2n −1 or 2n−2 as discussed by the authors.
Abstract: It is a well-known conjecture that if a regular graph G of order 2n has degree d(G) satisfying d(G) n, then G is the union of edge-disjoint 1-factors. It is well known that this conjecture is true for d(G) equal to 2n—1 or 2n—2. We show here that it is true for d(G) equal to 2n — 3, 2n — 4, or 2n — 5. We also show that it is true for d(G) |V(G)|.