Showing papers by "University of St Andrews published in 1980"

The economics of international integration

Abstract: Preface 1. Introduction 2. The theory of customs unions and free trade areas 3. Customs unions and free trade areas: Broadening the framework 4. Customs unions and "Public Goods" 5. Beyond customs union: The rationale for the integration of other economic policies 6. The theory of common markets 7. Fiscal integration 8. Monetary integration 9. Reginal problems and policy in a common market 10. Economic integration among developing countries 11. Integration among centrally planned economies 12. Empirical studies: Quantifying the extent and effect of integration Bibliogaphy Index

Exercise training in skeletal muscle of brook trout (salvelinus fontinalis)

Abstract: 1. The differentiation of myotomal muscles in the brook trout (Salvelinus fontinalis Mitchill) has been investigated using p-phenylene diamine stained semi-thin sections and cytochemical and quantitative determinations of enzyme activities. 2. Evidence is presented that the range of fibre size in white muscle represents stages in growth rather than distinct fibre types. 3. Electromyography shows that both red and white muscles are recruited for sustained swimming. The threshold swimming speed for recruitment of white fibres is around 1.8 body length/s (L/s). 4. White muscle citrate synthetase and cytochorome oxidase activities are 25-35% that of red muscle. Hexokinase, phosphorylase and phosphofructokinase activities are 2, 4 and 2 times higher in white than red muscles. It is considered that the aerobic capacity of white muscle is sufficient to support sustained swimming, and that blood glucose could be an important fuel source. 5. Endurance exercise training has been investigated in fish swimming, continuously, for 21 days at 3 L/s. This training regime restricts spontaneous high-speed swimming activity and resulted in a general decline of white muscle glycolytic enzyme activities. Red fibres underwent hypertrophy relative to non-exercised controls (530 +/- 64 microns2 non-exercised, 901 +/- 63 microns2 trained). Aerobic enzyme activities in red muscle and the fraction of fibre volume occupied by mitochondria (30.2 +/- 0.8%) did not change in response to the training programme, but glycolytic enzyme activities were elevated. 3-OH Acyl CoA dehydrogenase activities increased in both red and white muscles indicating an enhanced capacity for fatty acid catabolism with training. 6. Plasma and muscle lactate levels were not statistically different between tank-rested and trained fish swimming a 3 L/s. 7. Adaptations of fish muscle to endurance training are discussed and compared with results for other vertebrates.

Endurance exercise training in the fast and slow muscles of a teleost fish ( Pollachius virens )

Abstract: 1. The recruitment of muscle fibre types has been investigated in the coalfish (Pollachius virens) using electromyography. Red trunk muscles were active at all swimming speeds examined (0.25–3.6 lengths/s). Interestingly, white fibres were recruited at 0.8–2.0 lengths/s providing evidence that this muscle type is also used during sustained activity. 2. The effect of endurance exercise training on muscle fibre size and enzymes of energy metabolism has also been investigated. Fish were exercised continuously at 2.1 lengths/s for a period of three weeks in an experimental swimming chamber. This swimming speed represents a significant increase in work load relative to non-exercised fish as evidenced by muscle fibre hypertrophy and an increase in creatine kinase activities in both red (184%) and white (260%) muscles. 3. Glycogen storage levels increased to a greater extent in red (+520%) than white (+200%) muscles. Phosphofructokinase activity was eight times higher in the red muscle of exercised fish. In contrast, there was only a small increase in citrate synthetase (+30%) and no change in either hexokinase or cytochrome oxidase activities in the red muscle of trained fish. 4. Increased hydroxyacyl CoA dehydrogenase activities in both muscle types indicate an enhanced capacity for fatty acid catabolism with training. 5. White muscle phosphofructokinase activities were not significantly different in trained and untrained fish. It is likely that the maximum potential of white muscle for anaerobic glycogenolysis is already sufficient to meet all its energy requirements at this swimming speed. 6. The results suggest that the capacity of coalfish red muscle to do aerobic work remains essentially unchanged by endurance exercise training and that any increase in the ability to produce ATP must be met anaerobically.

A general correlation coefficient for directional data and related regression problems

Abstract: SUMMARY A correlation coefficient p2 iS proposed for bivariate angular distributions and for bivariate distributions on general manifolds. In the cylindrical case p2 iS the coefficient of Mardia (1976), and for the bivariate angular case it is a modified version of the correlation coefficient of Mardia & Puri (1978). Some properties of p2 are examined and compared with those of other bidirectional correlation coefficients. In particular, this coefficient is found to be closely connected with important exponential families of distributions. Further, the asymptotic distribution of the sample version of p2 under the hypothesis of independence does not depend on the marginal distributions. Thus it is asymptotically robust against concentration in the bivariate angular case. The regression models arising from complete dependence as measured by p2 are examined. A numerical example is given.

Temperature acclimation in crucian carp, Carassius carassius L., morphometric analyses of muscle fibre ultrastructure

Abstract: Carp show a partial compensation in metabolic rate and activity following temperature acclimation. In the present study crucian carp, Carassius carassius, were acclimated for eight weeks to either 2. Cor 28. C. The effects of temperature acclimation on muscle fibre ultrastructure has been investigated. The fractional volume (%) of each fibre type occupied by mitochondria and myofibrils was determined using a point counting morphometric method. Mitochondrial density was found to be higher in the muscles of cold (red fibres 25%; pink fibres 20% and white fibres 4%) than in those of warm acclimated fish (red fibres 14%, pink fibres 11%, white fibres I%). The proportion of subsarco1emmal to intramyofibrillar mitochondria was significantly lower in the red fibres of cold acclimated fish. Metabolic compensation to low temperatures are therefore associated with an increase in the number of mitochondria per cell. In contrast, the fractional volume occupied by myofibrils actually decreased following cold acclimation. Evidence is reviewed that temperature compensation of contractile activity results from qualitative rather than quantitative changes in myofibrillar proteins. I. INTRODUCfION

Desaturation of positional and geometric isomers of monoenoic fatty acids by microsomal preparations from rat liver

Abstract: A range ofcis- andtrans-monoenoic fatty acids was tested as substrates for desaturation in microsomal preparations from rat liver.Trans-monoenoic acids were generally desaturated in the Δ9 position to the same extent as stearic acid. Acids with Δ7-trans- and Δ11-trans-olefinic unsaturation produced Δ7-trans,9-cis- and Δ9-cis,11-trans-conjugated dienoic acids, respectively, but the Δ8-trans- and Δ10-trans-monoenoic acids did not give Δ8,9- or Δ9,10-allenes. Of thecis-monoenoic acids examined, only those with double bonds at or beyond the Δ14 position gave any measurable Δ9 desaturation. When Δ9 desaturation of long chain saturated acids was inhibited by adding sterculic acid, these saturated acids were desaturated at the Δ5 and Δ6 positions. Many of the monoenoic acids tested were also desaturated at the Δ5 and/or Δ6 positions, although the percentage conversions were always low. Δ9-cis,11-trans-, Δ9-cis,12-trans- and Δ9-cis,13-trans-dienoic acids, produced in situ by Δ9 desaturation of the corresponding monoenoic acids, were extensively desaturated in the Δ6 position. These results are discussed in terms of: (a) the various models proposed to explain the substrate specificities of the desaturases, and (b) the metabolism of unnatural fatty acids ingested from dietary sources.

Starvation and the activities of glycolytic and gluconeogenic enzymes in skeletal muscles and liver of the plaice,Pleuronectes platessa

Abstract: Changes in body index parameters and liver, red muscle and white muscle enzyme profiles have been determined in fed and four month starved plaice,Pleuronectes platessa. The results are compared to other vertebrates to estimate specific tissue metabolic patterns and changes in these patterns with starvation. 1. Liver demonstrates the lowest glycolytic but highest gluconeogenic capacity of the three tissues. Red muscle has little, if any, gluconeogenic potential, based upon low activities of phosphoenol pyruvate carboxykinase and glucose-6-phosphatase and no detectable activities of pyruvate carboxylase. Plaice white skeletal muscle has the highest glycolytic potential of the tissues studied. 2. Plaice starved for four months demonstrate significant reductions in liver-somatic index and red muscle-somatic index, and increases in tissue water contents (Table 1). Enzyme activities generally decline in both muscle types, but are maintained in the liver (Table 2). Activities of liver soluble phosphoenol pyruvate carboxykinase increase by approximately 8-fold, suggesting that the enzymic response to starvation in plaice is similar to that of mammals. 3. These results suggest that starvation in plaice is associated with both a decrease in spontaneous activity and metabolic capacity of skeletal muscles, and an enhanced potential for liver gluconeogenesis. Also, it is possible that the precursors for liver gluconeogenesis do not form pyruvate as an intermediate step.

Siphon flows in coronal loops: I. Adiabatic flow

Abstract: It is now known that the corona is filled with a multitude of loop-like structures. The likelihood of these loops being in static equilibrium is small and so this paper explores the possibility of steady isothermal or adiabatic flows, driven by a pressure difference between the loop feet. For a symmetric loop the flow becomes supersonic at the summit and is then retarded by a shock-wave at some point on the downflowing leg. The effect of adiabatic flow is to lower both pressure and temperature by at least a factor of two and so provide a possible explanation for the cool cores that are sometimes observed in coronal loops.

Dimensions of Organizational Structure: A Critical Replication

Abstract: In a critical replication and extension of the Astoi and National studies on the dimensions of organizational structure, a strong linkage was suggested between decentralization of operations, (but ...

Magnetic instability of coronal arcades as the origin of two-ribbon flares

Abstract: The generally accepted scenario for the events leading up to a two-ribbon flare is that a magnetic arcade (supporting a plage filament) responds to the slow photospheric motions of its footpoints by evolving passively through a series of (largely) force-free equilibria. At some critical amount of shear the configuration becomes unstable and erupts outwards. Subsequently, the field closes back down in the manner modelled by Kopp and Pneuman (1976); but the main problem has been to explain the eruptive instability. The present paper analyses the magnetohydrodynamic stability of several possible arcade configurations, including the dominant stabilizing effect of line-tying at the photospheric footpoints. One low-lying force-free structure is found to be stable regardless of the shear; also some of the arcades that lie on the upper branch of the equilibrium curves are shown to be stable. However, another force-free configuration appears more likely to represent the preflare structure. It consists of a large flux tube, anchored at its ends and surrounded by an arcade, so that the field transverse to the arcade axis contains a magnetic island. Such a configuration is found to become unstable when either the length of the structure, the twist of the flux tube, or the height of the island becomes too great; the higher the tube is situated, the smaller is the twist required for instability.

Communication between Individuals in Salp Chains II. Physiology

Abstract: When stimulated, salp chains achieve rapid coordinated changes in locomotion by the spread of epithelial action potentials or outer skin pulses (o.s.ps) from one zooid to the next along the chain. This process involves alternating epithelioneural and neuroepithelial chemical synapses. Each zooid is linked to another in the chain by two asymmetric attachment plaques; these are polarized so that transmission of o.s.ps proceeds from one zooid to the next in one direction at one plaque, and in the reverse direction at the other plaque. Sensory cells at the plaques send axons to the brain; they are not electrically coupled to the conducting epithelium in which they lie. Input from the plaque sensory cells affects the swimming generator in the brain (causing locomotor changes) and evokes synaptic activity at neuroepithelial synapses around the brain. This gives rise to o.s.ps that are conducted around the whole of the outer epithelium of the zooid and are detected at the plaques by the sensory cells of adjacent zooids. Severe stimulation of a zooid in the chain induces all zooids to separate; possible mechanisms of separation are discussed.

The New Constantine and the New Constantinople – 1261?

Abstract: On 15 August 1261 the emperor Michael VIII Palaiologos, born, raised, and crowned in ‘exile’ during the Latin occupation of Constantinople, entered the newly reconquered capital for the first time Michael carefully planned the ceremonial surrounding his entrance into Constantinople, choosing as his day of entry the feast day of the Dormition of the Virgin, the City's protectress, and giving her icon, known as the Hodegetria, a place of honour, in the celebrations The entire day's programme was intended as a thanksgiving to God rather than a celebration of an imperial triumph Preceded by the icon of the Hodegetria, the emperor walked through the Golden Gate, relinquishing his prerogative to ride in a quadriga through the gate which had received emperors returning triumphant from campaign In other words, Michael's entry was conducted

Predatory Behaviour in Domestic Cat Mothers

Abstract: This study documents quantitatively the change in predatory behaviour of domestic cat mothers as their kittens develop. Predatory behaviour in mother cats was found to decline as that of their offspring increased. Before kittens were 8 weeks old, mothers were more likely to interact with prey if their kittens had not been on the prey for a time; they led in interactions with prey. Kittens were found to show increased rates of predatory behaviour patterns in the presence of their mother. This paper then goes on to examine some of the mechanisms by which mothers are able to bring about such an improvement in their kittens' predatory behaviour. It was found that kittens interacted more frequently and for longer with prey following the mother's bouts. Kittens were more likely to quickly follow another cat on the prey than wait more than 10 seconds. However when siblings only were considered, they were less likely to follow a sibling in less than 10 seconds of it having been on the prey. After the eighth week, kittens attended to prey by themselves more often than would be expected by chance, whereas in the early weeks of exposure to prey, they were more likely to attend to prey while their siblings or their mother was watching prey.

Traffic Noise, Environmental Awareness, and Pedestrian Behavior

Abstract: Recent research has confirmed that social behavior, especially helpfulness, is affected by the environmental input level: As the level of environmental bombardment increases, the level of helpfulne...

Force-free magnetic arcades relevant to two-ribbon solar flares

Abstract: Simple analytic models for the passive evolution of arcade-like magnetic fields through a series of force-free equilibria are presented. At the photospheric boundary, the normal magnetic field component is prescribed together with either the longitudinal field component or the photospheric shear. Analytic progress is made by considering either cylindrically symmetric solutions or using the separation of variables technique.

The disposition of cadmium and zinc in Pandalus montagui.

Abstract: Cadmium uptake rates in various tissues ofPandalus montagui exposed to sea water containing 37 μgCd/L for 14 days ranged from 0.002–0.06 μg/g dry tissue/hr. During depuration for 57 days, the levels in most tissues decreased slightly, but continued to rise in the hepatopancreas indicating Cd redistribution. Exposure to 65 μg Zn/L produced no substantial change in Zn content of the tissues. An increase occurred in eggs and hepatopancreas during the first six days of depuration. During exposure to Cd and Zn combined (40 μg Cd/L + 70 μg Zn/L), tissue Zn levels responded as with Zn alone. In the presence of Zn, Cd concentration was doubled in the hepatopancreas, depressed by one-third in the carcass, and did not change in the other tissues. Increased amounts of Zn (up to 410 μg Zn/L) had no effect on the Cd levels of the tissues except that the Cd level in the hepatopancreas was depressed, although the level was still greater than in the case of exposure to Cd alone. The possible role of metallothionein is discussed.

Metamorphism in an accretionary prism: prehnite-pumpellyite facies metamorphism of the Southern Uplands of Scotland

Abstract: The lower Palaeozoic rocks of the Southern Uplands of Scotland have been interpreted as an accretionary prism of slivers of oceanic basalt and associated deep sea sediments situated on the northern margin of the lape tus Ocean. Electron microprobe analyses confirm the presence of albite, prehnite, pumpellyite, chlorite, phengite, calcite, hematite and quartz-bearing metamorphic assemblages in basalts and basic-clast greywackes in the prism. The metamorphism is prehnite-pumpellyite facies and inferred to be related to tectonic burial of the various slices of the prism as they were accreted during the closure of the lape tus Ocean.

Photoreversible control of heterophylly in hippuris vulgaris l.

Abstract: summary The freshwater macrophyte Hippuris vulgaris exhibits heterophylly. During July and August aerial-type leaves occur even on immersed shoots down to a depth of 15 m in two clear-water limestone lochs in Scotland. Complementary field and laboratory data indicate that a high intensity photoperiod and temperatures above 10°C are prerequisites for aerial-type leaf production on submerged shoots. In these conditions, regular injections of additional sucrose, the natural photosynthate, at 05 mol kg−1 fresh weight will not induce the aerial-type leaf. There is relatively little attenuation of blue light with depth in these lakes and additional blue light just after the photoperiod does not induce the aerial-type leaf. There is no evidence for an ontogenetic or circadian photoperiodic requirement for the production of aerial-type leaves, or that heterophylly is mediated by ethylene. However, a low ratio of red (R 660 run) to far red (FR 730 run) light throughout, or very dimly for a brief period just after, the photoperiod treatment regularly induces aerial leaf formation on submerged shoots of any length. A similar low R/FR ratio is found naturally in these lakes in summer at depths where submerged aerial leaves occur. Selective attenuation of far red by lakewaters raises the R/FR ratio steeply with increasing depth. At R/FR ratios above a critical range, which is similar in field and laboratory, aerial leaf formation is inhibited and only submerged-type leaves are formed. Simply by changing the R/FR ratio, either during or briefly after the photoperiod, transitions between submerged and aerial-type leaves are repeatedly reversible, implying direct phytochrome control.