Showing papers by "University of Reading published in 1970"

The kinetics of migration of point defects to dislocations

Abstract: In this review we discuss the various ways in which dislocations interact with and provide sites for the segregation of point defects. Since there is, in general, a long-range interaction between a point defect and a dislocation, the kinetics of the migration of the point defects to the dislocations will depend on the form and magnitude of this interaction. The origin of the interaction and the various spatial forms it can take are therefore discussed in some detail and related to the resulting kinetics. The early stages of this segregation process can be explained and the kinetics satisfactorily correlated with experimental observations without a detailed discussion of the physical situation prevailing at the dislocation cores. However, in the later stages of the segregation process the observed kinetics very often show a strong departure from simple first order and, in this case, an explanation requires a discussion of the detailed point-defect behaviour within the dislocation core region. Various physically plausible dislocation core situations are discussed and related, where possible, to pertinent experimental observations.

The Shakespearean Stage, 1574-1642

Abstract: Preface 1. Introduction 2. The companies 3. The players 4. The playhouses 5. The staging 6. The audiences Appendix: a select list of plays and their playhouses.

Puckering structure in the infra-red spectrum of cyclobutane

Abstract: The theory of rotational-pucker-vibrational transitions in the vibrational spectrum of cyclobutane is reviewed. Puckering sideband structure on the 1453 cm-1 v 14 infra-red fundamental of C4H8 has been observed and analysed, in terms of two slightly different puckering potential functions for the ground and the excited vibrational states. The results have been fitted to quartic-quadratic potential functions in the puckering coordinate, with a barrier to inversion of 503 cm-1 (1·44 kcal mole-1 = 6·02 kJ mole-1) in the ground state and 491 cm-1 in the excited state ν 14 = 1. For reasonable assumptions about the reduced mass, the equilibrium dihedral angle of the C4 ring is determined to be about 35°, in agreement with previous estimates. Ueda and Shimanouchi's observations on the 2878 cm-1 C4H8 band have been re-analysed, and puckering sidebands have also been observed and analysed for the 1083 cm-1 v 14 infra-red fundamental of C4D8. Pure puckering transitions have been observed in the Raman spectrum of C4...

Interpretation of rotational constants of the first singlet excited state of substituted benzenes in terms of molecular geometry

Abstract: The results of a comparison of the rotational constants of the first singlet excited state of five monosubstituted and five p-disubstituted benzenes show that (a) In the monosubstituted benzenes, it is reasonable to assume a common model in which, on electronic excitation, all the bonds in the ring expand as in the 1 B 2u state of benzene but that the carbon-substitutent bond contracts, the contraction being in the order N > O ≈ Br ≈ Cl > F and of approximate magnitudes 0·08, 0·04, 0·04, 0·04, 0·02 A respectively. There is also a tendency for the ring angle adjacent to the substituent to open by a few degrees. (b) In the p-disubstituted benzenes there is a slight shortening of the molecules along the long axis compared to the geometry of an excited state in which the two ends of the molecule and the C2C3 bond behave as in the corresponding monosubstituted benzenes. This effect is almost independent of the substituents, except in the case of -NH2 where it is largest, and probably results from the ring diff...

The Computation of Diffraction Patterns in the Presence of Aberrations

Abstract: The diffraction integral for the disturbance produced in the image plane normal to the optical axis by an extra-axial pencil has been shown to lead to a Fourier transform provided the exit pupil surface is taken to be that of the reference sphere. It has been shown also that, except for small aperture and field sizes, the effect on the wave-front aberration of a shift of the image plane is not represented with sufficient accuracy merely by a term proportional to the aperture squared. Both of these results have been respected in formulating a numerical technique for the calculation of point spread functions. The diffraction integral is evaluated in polar coordinates, and is such that no error is made in approximating the domain of the exit pupil in cases where this may be represented by an ellipse. A study of the accuracy obtained has shown that, if each quadrant of the pupil is divided into a 20 × 20 mesh of elementary areas, the error in the intensity is not expected to exceed 0·8 per cent of the intensi...

A New Method for Minimising a Sum of Squares without Calculating Gradients

Abstract: A new method for minimising a sum of squares of non-linear functions is described and is shown to be more efficient than other methods in that fewer function values are required.

Photoperiodism in the ewe: 2. The effects of various patterns of decreasing daylength on the onset of oestrus in clun forest ewes

Abstract: In six light-proofed buildings experiments were conducted with Clun Forest ewes to determine whether the date of first oestrus was affected by the absolute size of reduction in the case of an abrupt decrease in daylength and by the rate of reduction in the case of a given total decrease in daylength.The mean number of days from the onset of the light treatments to first oestrus (the reaction interval) for ewes receiving gradual decreases in daylength of 3·5, 7·2 or 10·9 min/day from 1 July were 66·4, 53·7 or 33·6 days, respectively. The reaction interval for ewes receiving abrupt decreases in daylength of 3·75, 7·75 or 11·75 hr on 1 July were 59·5, 44·8 or 33·6 days, respectively. A control group of ewes at pasture on natural daylength had a mean reaction interval of 66·2 days.It is concluded that the various light treatments applied significantly affected the date of onset of oestrus in Clun Forest ewes.

Remote Sounding of Atmospheric Temperature from Satellites. I. Introduction

Abstract: Atmospheric temperature can be sounded remotely by observing the emission from carbon dioxide in its 15 $\mu $m band. The principles of design of suitable instrumentation for such observation are reviewed. An instrument employing a selective chopper enables emission from higher altitudes to be selected than is possible with conventional instruments.

Tables of Sample Sizes in the Analysis of Variance

Abstract: Tables are provided which give the minimum sample sizes per treatment (or level) for all combinations of alpha = 0.5, 0.3, 0.25, 0.2, 0.1, 0.05, 0.01 and beta = 0.3, 0.2, 0.1, 0.05, for relative discrimination (Delta/Sigma) = 1.0(0.5)3.0, and for the nu..

Petrochemical variations among mildly peralkaline (comendite) obsidians from the oceans and continents

Abstract: Eleven new analyses and modes of comendite obsidians are presented, and compared with all available data on similar rocks. Most specimens are aphyric or contain only sparse phenocrysts, most commonly alkali feldspar. The oxides SiO2, Al2O3, Na2O and K2O total over ninety percent by weight in all analyses. Iron, as FeO, is the only other constituent rising above one percent by weight. When the analyses are projected into the system Na2O-K2O-Al2O3-SiO2, oceanic and continental samples group differently. Oceanic specimens have a compositional spread ranging from trachytic to the quartz-feldspar cotectic zone, consistent with derivation through a trachyte magma stem. Continental comendites show a strong correlation with the experimentally determined quartz-feldspar minima along a path of increasing peralkalinity. These differences presumably reflect the contrasting environments of magma generation, and suggest an origin by partial melting within the continental crust for the continental comendite obsidians.

Rotational band contour analysis in the 2700 Å system of chlorobenzene

Abstract: The origin band of the 2700 A system of chlorobenzene has been rotationally analysed by the asymmetric rotor band contour method. It is shown to be a type B band of a prolate asymmetric top which requires the electronic assignment of the system to be 1 B 2-1 A 1. The excited state rotational constants are: A′=0·1797 ± 0·0001 cm-1, B′=0·05230 ± 0.00002 cm-1, C′=0.040512 ± 0.000007 cm-1. These can be interpreted in terms of a contraction of the C-Cl bond of about 0·04 A and an expansion of the benzene ring similar to that in the 1 B 2u excited state of benzene. The origin of the 2700 A band is shown to be at 37 048·2 ± 0·2 cm−1. Strong type A bands involving the b 2 vibration v 29 are also assigned from their rotational contours. The 291 level is shown to be in Fermi resonance with the 141201 level. Of the eight prominent sequence intervals associated with the origin band, five are interpreted with considerable certainty.

Studies of membrane, mammilary cores and cuticle of the hen egg shell

Abstract: Synopsis Mammillary cores and outer shell membrane have been studied by comparing the weight and chemical composition of outer membrane with cores still attached and of outer membrane free from cores, from the same shells. Inner membrane and cuticle have also been investigated. The weights of inner and outer membrane are significantly correlated (P < 0.05). Both membranes contain galactosamine, glucosamine, sialic acid, glucose, mannose and fucose but in different proportions. Uronic acid is probably absent. An average of 3.3 mg of organic mammillary core material per shell (52 μg/cm2) was present in the shells investigated, but there was a trend suggesting that eggs laid by more mature hens may contain rather more. Cores are rich in hexo‐samine, sialic acid and hexose, but the probable absence of uronic acid suggests that chondroitin sulphates play no part in shell initiation. There were no major differences in the amino acid spectrum of membrane samples with and without cores. Galactosamine, glucosamine...

On the mass transport induced by oscillatory flow in a turbulent boundary layer

Abstract: Oscillatory flow in a turbulent boundary layer is modelled by using a coefficient of eddy viscosity whose value depends upon distance from a fixed boundary. A general oscillatory flow is prescribed beyond the layer, and the model is used to calculate the mass transport velocity induced by this within the layer. The result is investigated numerically for a representative distribution of eddy viscosity and the conclusions interpreted in terms of the mass transport induced by progressive and standing waves. For progressive waves, the limiting value of the mass transport velocity at the outer edge of the layer is the same as for laminar flow. For standing waves, the limiting value is reduced relative to its laminar value but, within the lowermost 25% of the layer, there is a drift which is reversed relative to the limiting value. This is considerably stronger than its counterpart in the laminar case and, in view of the greater thickness of the turbulent layer, it may make a dominant contribution to the net movement of loose bed material by a standing wave system.

Pseudomonas viridiflava (Burkholder, 1930; Clara 1934).

Abstract: Summary. The characteristics of 12 isolates from 7 different hosts which were believed to be Pseudomonas viridiflava were studied using a variety of cultural and biochemical tests; in nutritional tests, 135 compounds were screened for their ability to serve as sole carbon and energy (C/E) sources. All cultures were similar in character and resembled closely Burkholder's original isolates: they were distinguishable from 13 cultures of other phytopathogenic Pseudomonas spp. Although they closely resembled Ps. syringae, they could be distinguished by their ability to rot potato, to utilize d(—) tartrate as sole C/E source and by their failure to utilize sucrose and to form levan on 5% sucrose nutrient agar. Pseudomonas viridiflava is a common epiphyte at least on dwarf beans (Scarlett, 1968) though it has rarely been cited as a cause of disease in Phaseolus spp. Results of lesion tests in dwarf bean pods and in the tobacco hypersensitivity test together with pectolytic activity strongly suggest however that it is a potential pathogen.

Some experiences with the general foods texturometer.

Abstract: As part of a programme of investigation into the effects of processing on the texture of food the General Foods Texturometer was adopted, because it appeared to offer versatility, multiple-property determination and a fair degree of objectivity. Preliminary investigations with the instrument indicated a high degree of reproducibility when used on a 'recoverable' material (rubber). The results are highly dependent on the dimensions of the sample and reproducibility decreases somewhat with increasing hardness of material under test. The 'representativeness' of the results for a range of food materials varied widely, being influenced by the uniformity of the material and the accuracy with which samples can be prepared. Experiments to correlate the results from this instrument with those from the Instron Universal Testing Machine, the Kramer Shear Press and a subjective panel method indicate that the Texturometer 'hardness' might prove the most useful measure of the firmness/hardness of foods as judged subjectively. None of the other textural properties measured by the Texturometer in this work proved of value in indicating subjective textural characteristics and further study of such properties is currently in progress.

Plant Density and Crop Yield

Abstract: In investigations into the relationship between mean plant density and crop yield, an inverse power response curve has often been used. In this paper the theoretical properties of a family of these curves are examined, including situations where two or more such relationships are being compared. Methods of fitting these response models are given. When response curves are fitted to experimental data it is usually desirable to summarize the data as briefly as possible and this leads to a search for parameter invariance. A formal scheme for analysing data by looking for invariance of parameters of the response curves is proposed and methods are given for fitting the various constrained models that this involves. These methods are illustrated in two examples.

Mass transport in layered fluid systems

Abstract: The method of matched asymptotic expansions is employed to calculate the mass transport velocity due to small amplitude oscillatory waves propagating in conditions of density and viscosity discontinuities. For progressive waves in a two-layer system, it is found that the velocity at the interface is in the direction of wave propagation; when the uppermost surface is free, the velocity there is in the direction opposite to that at the interface. If the difference in the densities is small, the calculated transport velocity associated with an internal wave can be of more importance than that associated with the surface wave as obtained from the work of Longuet-Higgins (1953).

Contraction of protoplasm. IV. Cinematographic analysis of the contraction of some peritrichs.

Abstract: The contraction and relaxation of Vorticella difficilis, V. campanula and Carchesium sp. were studied by high speed cinematography. In Vorticella it was shown that coiling of the stalk usually started near the zooid and spread downwards; the point of initiation bore no relation to the position of the stimulating electrodes. Contraction took about 5 msec to complete, and the fully contracted animals were 29 ± 3.9% of their original lengths. The zooids were 66 ± 5.0% and the stalks 14 ± 6.0% of their original lengths (V. difficilis). The shortening of the stalk was mostly in the form of coiling. Measurement of the myoneme length demonstrated that its real shortening was less than 10%. Thus the contraction is virtually isometric, producing a helical deformation of the stalk. As the stalk contracts it takes the form of a steeply pitched helix. This change in shape should produce rotational forces on the zooid (torque). Physical models of similar proportions produced about 1.5 revolutions of torque for similar changes in pitch. However during contraction no turning of the zooid was detected, though rotation did occur after the completion of contraction. In Carchesium the contraction is not so isometric, the myoneme apparently shortening by 20%. While the coiled shape of the contracted Vorticella stalk can be explained by its acentric structures, the stalk of Carchesium is much more symmetrical in cross-section, demonstrating that a high acentricity is not necessary for helical coiling. In all three species there seems to be some separation of the control of zooid and stalk contraction.

The adsorption and mobility of paraquat on different soils and soil constituents

Abstract: Summary. The adsorption capacity for paraquat of the following materials was examined: three peat soils; two peaty layers below a turf; a commercial sphagnum peat; grass; Begbroke soil; Fullers’ earth; humic acids isolated from a peat soil; lignin isolated from hardwood sawdust; cellulose powder. The Strong Adsorption Capacity (SAC) of these adsorbents was examined first using a chemical method of analysis and then with the more sensitive Lemna bioassay. Peat soils had an appreciable SAC for paraquat even when measured with the bioassay (88–165 kg/ha 2–5 cm depth, 750–1000 ppm), > 10 times that of Begbroke soil (14 kg/ha, 50 ppm). Humic acids had a higher adsorption capacity (k = 42, 000) than lignin (k = 2600), while cellulose adsorbed very little paraquat (k = 64). The adsorption of paraquat decreased as the ratio of soil to water increased. Temperature appeared to have very small effects on adsorption in organic soils. Results were consistent with calcium competing for adsorption sites. Paraquat sprayed on the surface of a peat soil up to 36 kg/ha remained in the top 7 mm after leaching with 305 mm of natural rainfall over a period of 4 months. Paraquat adsorbed on commercial sphagnum peat could transfer to clays after incorporation and be inactivated. Adsorption et mobilite du paraquat sur diffetrents sols et constituents du sol Resume , La capacitye d'adsorption du paraquat par les milieux suivants a eteetudiee: 3 sols tourbeux, 2 assises tourbeuses sous un gazon, une tourbe commerciale de sphagnum, une tourbe, un sol de Begbroke, une terre a foulon, un acide humique extrait d'un sol tourbeux, une lignine extraite d'une sciure de bois dur, de la poudre de cellulose. La capacitye brute d'adsorption (CBA) de ces adsorbants a ete examinee, au moyen d'une methode chimique d'analyse puis avec la methode biologique plus sensible utilisant Lemna. Les sols tourbeux montrerent une CBA appreciable pour le paraquat meme lorsqu'elle fut mesuree par la voie biologique (88/165 kg/ha 2,5 cm de profondeur, 750–1000 ppm), plus de 10 fois celle du sol de Begbroke (14 kg/ha 50 ppm). Pour les acides humiques, la capacitye d'adsorption fut plus eievee (k = 42 000) que pour la lignine (k = 2600) alors que la cellulose n'adsorba que tres peu de paraquat (k = 64). L'adsorption du paraquat diminua a mesure que le rapport sol/eau augmentait. La temperature n'eut que de tres faibles effets sur l'adsorption dans les sols organiques. Les resultats furent en accord avec la concurrence du calcium pour les lieux d'adsorption. Le paraquat appliquea la surfaee d'un sol tourbeux jusqua la dose de 36 kg/ha resta dans les 7 premiers millimetres apres lessivage par 305 mm de pluie natureile pendant une periode de 4 mois. Le paraquat adsorbe sur une tourbe commerciale de sphagnum put etre transferee des argiles aprte avoir ete incorpore et inactiveee. Adsorption und Beweglichkeit von Paraquat in verschiedenen Boden und Bodenbestandteilen Zusammenfassung. Die Adsorptionskapazitat von Paraquat wurde fur folgende Materialien untersucht: 3 Torfboden; 2 torfige Schichten unter einem Rasen; 1 handelsublicher Sphagnum-Torf; Gras; Begbroke-Boden; Fullers′-Erde; aus einem Moorboden isolierte Huminsauren; aus Hartholz-Sagemehl isoliertes Lignin; Cellulosepulver. Die Kapazitat zur festen Adsorption (Strong Adsorption Capacity, SAC) dieser Adsorptionsmittel wurde zunachst mit Hilfe einer chemischen Analysenmethode untersucht und anschliessend mit dem empfindlichen Lemna-Biotest. Torfboden hatten fur Paraquat auch bei Messung mit dem Biotest einen deutlichen SAC (88–165 kg/ha 2,5 cm tief, 750–100D ppm), der mehr als 10 mal den Wert von Begbroke-Boden (14 kg/ha, 50 ppm) betrug. Huminsauren hatten eine hohere Adsorptionskapazitat (k - 42000) als Lignin (k = 2600), wahrend Cellulose Paraquat nur sehr wenig adsorbierte (k = 64). Die Adsorption von Paraquat nahm in dem Masse ab wie sich das Verhaltnis von Boden zu Wasser erhohte. Die Temperatur hatte offensichtlich einen sehi geringen Einfluss auf die Adsorption in organischen Boden. Reproduzierbare Ergebnisse konnten bezuglich der Konkurrenz mit Calcium um die Adsorptionsorte gefunden werden. Auf die Oberflache eines Moorbodens in einer Aufwandmenge von 36 kg/ha gespritztes Paraquat verblieb nach Einwaschung mit 305 mm naturlichem Regen wahrend einer Periode von vier Monaten in den oberen 7 mm. An handelsublichcn Sphagum-Torf adsorbiertes Paraquat wurde nach Incorporation an Ton ubertragen und auf diese Weise inaktiviert.

Some factors affecting the growth of prosobranch veligers

Abstract: 1. Larvae ofCrepidula fornicata (L.) andNassarius reticulatus (L.) were used for experiments. The conditions under which they thrived proved successful for veligers of other species. 2. They were kept in glass-filtered sea water (pore size 3.0µ) in acid-clean glass containers, provided with algal foods and handled carefully by means of a pipette. Trapping larvae in a coarse filter as a means of transferring them from one vessel to another was injurious. 3. Shell length was used to estimate growth. 4. The growth of 20 veligers in 30 ml sea water (depth 8 cm) was compared with that of 333 veligers in 500 ml (depth 9 cm). Growth in the larger volume was better, but in all cases the differences were not significant at the 10% level. 5. Growth rate is influenced by light intensity. For comparing the value of different foods experiments were carried out under a constant intensity of 155 lux at the water surface. In the dark, mortality of algal cells stimulates growth of bacteria. 6. The water temperature was maintained at 12° C. Low temperatures, even 8° C, reduce the activity of veligers ofCrepidula fornicata andNassarius reticulatus; high temperatures favour bacterial growth. 7. The growth of recently hatched veligers feeding on one of 10 species of unicellular algae and on some mixtures of these was recorded for 2(C. fornicata) or 3(N. reticulatus) breeding seasons. Food was given at different concentrations (2 × 103, 20 × 103, 40 × 103 cells/ml) which were calculated from haemocytometer counts of the stock cultures, though this gives only an approximate value. Experiments lasted up to 4.5 weeks and a few for a longer period. 8.Cricosphaera ap.carterae andExuviaella baltica were the best foods forCrepidula fornicata, especially at higher concentrations, and larvae were ready to metamorphose in 40 days or less.C. ap.carterae andDunaliella primolecta were good forNassarius reticulatus, especially the former, andE. baltica consistently poorer. 9.Monochrysis lutheri andPyramimonas grossii were moderately good foods, but with these none of the larvae metamorphosed. When fed toCrepidula fornicata at high concentrations (80 × 103, 120 × 103 cells/ml) growth of the former approached that withCricosphaera ap.carterae whilst with the latter growth decreased with increased concentration. The food value ofPhaeodactylum tricornutum is lower; the large frustules irritate the gut and act as a purgative. 10.Chlamydomonas parkeae, Brachiomonas submarina, Exuviaella pusilla andOlisthodiscus sp. are poor foods; the last two are toxic. 11. When the food was 2 species of alga mixed in equal proportions the good value ofCricosphaera ap.carterae was still evident. Examination of the stomach contents showed that the larvae were not feeding selectively on this alga. When the second alga was one with smaller cells(Monochrysis lutheri orPyramimonas grossii) these were ingested in greater numbers in accordance with the ease with which the velar cilia manipulated them. 12. Algal cells are subjected to mechanical treatment in the stomach; their walls may be shattered but no fragment has been seen in the cells of the digestive gland. The resistance of cells with complete cellulose walls suggests the absence of a cellulase. 13. With some algal foods (species ofMonochrysis, Pyramimonas, Phaeodactylum) the walls produce a high proportion of faecal waste which, in less vigorous larvae, may clog the exhalant passage of the mantle cavity. 14. Plant pigments are egested by the veliger. They are intimately linked with food, taken into ingesting cells of the digestive gland and later excreted. They thus delay the cycle of events in the gland. 15. Differences in food value of the various algae may be due to differences in micronutrients and vitamins essential to growth. The fact that one species of alga may produce good growth in one species of veliger and not another must reflect either differences in requirements or in assimilation of the food. 16. Prosobranch veligers are found in numbers well below the compensation depth as well as in other areas where the density of algal cells is low. It is suggested that organic detritus in the sea is an important item of food.

Content of inositol phosphates in some english and nigerian soils

Abstract: Summary The mono-, di-, tri-, tetra-, penta-, and hexaphosphates of inositpl accounted for between 11·2 and 30·4 per cent of the organic P in three English and four Nigerian soils. M yoinositol hexaphosphate was the component present in greatest amount in all soils. The lower esters (mono-, di-, and triphosphates) accounted for less than 3 per cent of the organic P in all soils, with the lowest amounts in the soils from Nigeria. For the penta- and hexaphosphates the ratio of myo- plus dl- isomers to scyll oinositol varied from 2·9 to over 10, the highest ratio occurring in the soils from Nigeria. Examination of the techniques showed that they gave approximately correct estimates of the inositol phosphates. The organic P in soil which was not estimated as inositol phosphate occurred in other forms.

An activity allocation model for the Nottinghamshire-Derbyshire subregion

Abstract: Batty M. (1970) An activity allocation model for the Nottinghamshire-Derbyshire subregion, Reg. Studies 4, 307–332. This paper outlines the development of a quantitative model, designed to explain the location of population and service employment in the Nottinghamshire-Derbyshire subregion. The model uses an economic base mechanism to derive population and service employment from basic employment, and spatial interaction submodels to locate the population and service employment in different zones of the subregion. To fit the parameters of the model, a two-stage calibration process is developed, incorporating a simple hill-climbing procedure which involves successively improving the values of the model's parameters until a best fit is reached. Assessments of the calibration process reveal certain structural weaknesses in the model. A description of the recursive projections made with the model is provided and demonstrated in relation to a hypothetical development strategy for the Nottinghamshire-Derbyshire...

The Failure of Aid and Adjustment Policies in Sub-Saharan Africa: Counter-examples and Policy Proposals

Abstract: In Africa, contrary to the experience of the rest of the developing world, aid flows as a share of GNP have increased enormously, but there is little evidence that this increase has been favourable to growth, or that the conditionality designed by donors in the 1980s to increase the effectiveness of aid has, in the aggregate, done so. This paper investigates why, using a game-theory model in which both donor and recipient seek to extract maximum advantage both from aid flows and from the policy conditions attached to them. Two important predictions of the model are that conditionality will in general be breached without penalty unless compensation is provided to losers and/or the implementation of conditions empirically proves itself effective. These predictions are confirmed in the African case. In Uganda, Mauritius and Ghana — the three countries where, as a result of compensation of losers and consistent investment and export development policies, donor policy recommendations proved credible — those recommendations were implemented and aid was effective. In all other adjusting African countries, conditionality was not credible in the sense of leading to a short-run increase in output, and aid flows were not effective.