Showing papers by "University of Stirling published in 1987"

Performance indicators in higher education

Abstract: Interest has been increasing in many countries in assessing performance of higher education institutions (and also departments within institutions). Two important reports in the U.K. in recent years have strongly advocated the use of performance indicators for this purpose. This paper argues that such indicators cannot be used in a meaningful way without a clear view of institutional goals. Problems of deriving such goal systems are discussed and a critical review of work done in this field is presented. Methodological problems associated with devising and using effective and useful performance indicators are described and research undertaken in this field outlined. Finally the authors outline the conditions under which they believe performance indicators may be used to give valid insights into performance of institutions (or departments).

Accuracy and precision of methods for estimating river loads

Abstract: River loads often have to be estimated from continuous discharge data but relatively infrequent sampling of sediment, solute, or pollutant concentrations. Two standard ways of doing this are to multiply mean concentration by mean discharge, and to use a rating curve to predict unmeasured concentrations. Both methods are known from previous empirical studies to underestimate true load. Statistical considerations explain these biases and yield correction factors which can be used to obtain unbiased estimates of load. Simulation experiments with normally-distributed scatter about log-linear trends, and sampling experiments using a natural data set, show that the corrected rating curve method has lower sampling variability than other unbiased methods based on average instantaneous load and is thus the recommended procedure when the rating plot is of the assumed form. The precision of all methods increases with sample size and decreases with increasing rating-curve slope and scatter.

Tropical rain forest

Abstract: There have been several recent regional accounts which partly or wholly deal with rain forest and its environment. These include three important syntheses for Amazonia (Hemming, 1985a; 1985b; Prance and Lovejoy, 1985; Sioli, 1984) and one for West Africa (Lawson, 1986). It is good to see a substantial monograph on the rain forests of the Western Ghats, southwest India (Pascal, 1984). These isolated Indian rain forests have until recently received little study although they are of much interest. They occur under a highly seasonal climate with a dry season of 4-8 months and in this respect they are probably unique amongst the world’s evergreen rain forests. In addition they endure low night-time temperatures which fall to below 10°C in screens in clearings at 575 m (Rai and Proctor, 1986a). Some examples of these forests (Rai and Proctor, 1986b) have the least fine litterfall (3.4-4.2 t ha-1 yr-1 ) for lowland evergreen rain forest. Pascal’s (1984) account complements the work of S.N. Rai on the biomass and production and other aspects of these forests. A summary of Rai’s work has been given by Proctor (1986). A descriptive paper dealing with an area of the little known and scarcely extant rain forest of Mauritius has been published by Lorence and Sussman (1986). They studied two stands of mature evergreen wet forest on Mascarene Island to assess the extent of invasion by weedy exotics. The stands were remnants of the indigenous Mauritian rain forest which is now reduced to a total area of 585 ha. It was found that

Developmental differences in the span of visual memory for pattern

Abstract: A procedure is described which gives a measure of memory span for patterns. Results are presented from a study of four age groups: 5+, 7+, 11+, and adults. Pattern span increases rapidly between the ages of 5 and 11, by which time it is at the adult level. Span is decreased by an interpolated interfering task, and there is memory decay over a 10 second unfilled interval. The results are interpreted as evidence for a system for representing patterns which is shared by short- and long-term visual memory, but which is distinct from systems for verbal representation.

Lipid Composition of Zooplankton in Relation to the Sub-Arctic Food Web

Abstract: Seasonal changes in the lipid class composition and fatty acid and fatty alcohol composition of neutral lipids were determined for Calanus finmarchicus, Metridia longa and Sagitta sp. in Balsfjord, northern Norway. Similar analyses were obtained for C. hyperboreus and Parathemisto abyssorum in an adjacent fjord, Ullsfjord, in spring. C. finmarchicus, C. hyperboreus, M. longa, and Parathemisto abyssorum all contained large amounts of wax esters whereas Sagitta sp. contained small amounts of triacylglycerols and traces of wax esters. the levels of wax ester in C. finmarchicus and M. longa were highest in late autumn (respectively 88% and 84% of total lipid) and lowest in early spring (respectively 85% and 27% of total lipid). The accumulation of these neutral lipids in spring and summer is related to the feeding activity during the primary production period, while their decline in late winter is associated with the mobilisation of metabolic energy for production of gonads. The major fatty alcohols in the wax esters of C. finmarchicus and C. hyperboreus and Parathemisto abyssorum were 20:1 and 22:1 while those in the wax esters of M. longa were 14:0 and 16:0. The traces of wax esters in Saqitta were rich in 20:1 and 22:1 fatty alcohols. These analyses are consistent with C. finmarchicus and C. hyperboreus being strictly herbivorous, M. longa being more carnivorous and both Sagitta sp. and Parathemisto being highly carnivorous, probably ingesting substantial amounts of calanoid copepods.

Weber fractions for weight and mass as a function of stimulus intensity.

Abstract: Laboratory simulations of weightlessness have shown that the Weber fraction for mass is higher than that for weight in the range 1000–7000 g. Experiments in the weightless conditions of orbital and parabolic flight have found the same at the 50 g level. To obtain measures at intermediate intensities, the Weber fractions for weight and mass were measured for 15 subjects at 50, 200 and 400 g. The stimuli were canisters suspended on strings. The subjects lifted them for the weight condition and swung them firmly sideways for the mass condition. The Weber fraction was higher for mass than for weight at all intensities, and increased at 50 g for both conditions. In a second mass condition, in which the subjects shook the cylinders within a loosely clenched hand, the Weber fraction remained almost constant at all intensities and was significantly smaller than for the firm swing method at 50 g. The differences in performance between conditions may be related to the continuity or intermittency of pressure informa...

Property portfolio allocation: A multi‐factor model

Abstract: Summary The objective of the paper is to describe a method of portfolio allocation currently being developed in the property sector. The model applies a multi‐index approach to portfolio decision making and enables investors to explore the effects of changing their allocational decisions. In estimating the parameters required for the model, we explain the method which can be used to adjust for smoothing effects on returns caused by the valuation process. Although the model is still at the development stage, the approach is general and can be applied both to allocating funds within a mixed‐asset portfolio or between different types of property within a wholly property‐orientated portfolio.

Chimpanzees using stones to crack open oil palm nuts in Liberia

Abstract: The use of stone-tools to open palm nuts (Elaeis guineensis) was studied in a group of 16 chimpanzees (Pan troglodytes) released from captivity to a natural island setting in Liberia. The behaviour was started by one female of the group; it then spread to 12 others over periods varying from a few seconds to a few weeks. Nut-cracking soon spread to three other sites, both spontaneously and with human encouragement. Both nuts and tools were carried distances of several hundred meters. Social interaction at cracking sites was rich and varied, ranging from fights over possession of tools to unsolicited sharing of nuts. Nut-crackers showed selectivity in schoosing “good” nuts and varied their methods according to the qualities of the nuts. Individual differences in technique emerged. These are the first detailed behavioural data on palm-nut-cracking, and they show many parallels with nut-cracking of other species by chimpanzees of the Tai Forest, Ivory Coast. This is another example of hammer-stone use from a limited region of West Africa: southeastern Guinea, eastern Liberia, and western Ivory Coast. This suggests limited cultural diffusion of the custom.

A study of the sequential clinical and pathological changes during proliferative kidney disease in rainbow trout, Salmo gairdneri Richardson

Abstract: . A histological study of 0+ rainbow trout, exposed to proliferative kidney disease (PKD) on an infected farm, showed evidence of infection from the beginning of June, gross pathological changes from the beginning of July, and clinical signs from mid-July. Evidence of healing was present in some samples from the second week of August. Kidney samples were divided into five grades (0–4) representing increasing severity of pathology. A sixth grade (H) was applied to kidneys showing signs of healing. The most frequent clinical signs were abdominal distension and exophthalmos. Melanosis, corneal cloudiness and ecchymoses were observed occasionally. Apart from renal enlargement, other internal gross pathological changes included ascites, gill and liver pallor, oedema, petechiation, and splenic enlargement. The majority of clinical signs and internal changes were only seen in fish with advanced renal swelling (grades 3 and 4). Histopathology was most marked in the kidney and was of three types: haemopoietic hyperplasia, vascular pathology and diffuse inflammatory change. Vascular changes, including occlusion of blood vessels in several organs and apparent haemoglobin crystallization, and destruction of renal excretory structures within areas of chronic diffuse inflammation were marked features of the histopathology in fish with clinical signs. The pathogenesis of PKD is discussed with reference to the histopathological changes.

Contributions by fungi and bacteria to aggregate stability of cultivated soils

Abstract: SUMMARY Stability changes during ageing (sterile) or incubation (non-sterile) of both natural field aggregates and remoulded aggregates from five soils were studied for periods up to 30 days. Growth of fungal hyphae, estimated by ergosterol measurement, corresponded to temporary stability increases in both types of aggregates during the first 15 days. Thereafter, fungal hyphae disappeared and were replaced by actinomycetes and bacteria. Increased stability due to entanglement by hyphae was comparable to that due to thixotropy in remoulded aggregates. Bacterial growth accompanied the fall in stability associated with fungal decline, but had little direct effect in stabilizing soil aggregates. Destruction of polysaccharides by periodate oxidation greatly diminished aggregate stability. The role of bacterial polysaccharides in soil aggregate stability is discussed.

The nature of sensorimotor adaptation to altered G-levels: evidence from mass discrimination.

Abstract: Mass discrimination is impaired under zero G compared to 1 G. This is partly due to loss of weight information (a reduction in z-axis pressure stimulation), and probably also to incomplete adaptation to the reduced G-level. Maladaptation to an increased G-level postflight causes objects to feel too heavy and weight discrimination to be impaired. Video tapes of hand movements while shaking test objects were made before, during, and after the D-1 Spacelab mission. Movements were faster inflight than preflight, slowed down postflight and returned to baseline by about the third day. Corresponding changes in movement amplitude also occurred. Errors of weight or mass perception during the maladaptation phase may be due to both inadequate monitoring of command signals and to inappropriate scaling of afferent signals. High-acceleration shaking was found to improve mass discrimination but impair weight discrimination.

Spectra of unicyclic graphs

Abstract: Unicyclic graphs are discussed in the context of graph orderings related to eigenvalues. Several theorems involving lexicographical ordering by spectral moments as well as the ordering by the largest eigenvalue are proved. An appendix contains a table of the 89 unicyclic graphs on eight vertices together with their spectra, spectral moments and characteristic polynomials.

The treatment of money in regional economics

Abstract: . A survey of regional monetary theory suggests a regional segmentation of financial markets on the basis of differences in portfolio preference, or market imperfections. These possibilities are explored here using post-Keynesian monetary theory. It is concluded that the availability of credit to a region depends more on the (potentially volatile) degree of confidence in the regional economy. The amount of liquidity thus generated depends on the propensity for capital flight due to liquidity preference. The resulting tendency for regions attracting low degrees of confidence to experience liquidity shortage will be greater the more integrated the national banking system.

Aphanomyces astaci pathogenicity under laboratory and field conditions

Abstract: . The high pathogenicity of Aphanomyces astaci to susceptible crayfish has often been mentioned but not well investigated in publications on crayfish plague. This paper presents a study of that pathogenicity and considers the relationships between size of zoospore challenge and challenge temperature, which results in the extremely complex series of pathologies which comprise crayfish plague.

Abnormal Hepatic Copper Storage in a Teleost Fish (Morone americana)

Abstract: Excessive copper storage in livers of feral white perch (Morone americana) from the Chesapeake Bay is described. Age-related, progressive accumulation of hepatic copper in levels often exceeding 1,000 micrograms/g wet weight was associated with peribiliary fibrosis and inflammation, bile duct hyperplasia, prominent, enlarged melanomacrophage centers, and disruption of hepatic architecture in older fish. Levels of zinc were mildly elevated compared to striped bass (Morone saxitilis) and adult rats. Cholangiomas were found in two perch. Rubeanic acid-stained liver had abundant copper-positive cytoplasmic granules in hepatocytes and cells of melanomacrophage centers. Subcellular fractionation showed that 90% of hepatocellular copper was in nuclei/cell debris fractions (which also contain tertiary lysosomes). Using electron probe microanalysis, high copper levels were localized in hepatocellular cytoplasmic bodies. Resolution of hepatic cytosol by gel permeation chromatography indicated that approximately 50% of the cytosolic copper in the white perch was bound to non-specific high molecular weight proteins, with the remaining 50% eluting at a peak where rat metallothionein is located. Ultrastructural examination revealed abundant lysosomes, increased size and number of peroxisomes, and increased density and numbers of mitochondrial matrix granules. This study indicates that white perch may be a model for studying effects of excessive copper accumulation and cellular mechanisms which control copper kinetics.

The effects of malachite green upon proliferative kidney disease

Abstract: . When rainbow trout infected with proliferative kidney disease (PKD) held in the laboratory were treated with malachite green and formalin to cure ichthyophthiriasis it was observed that subsequent development of PKD was delayed. Experiments are reported which indicate that this was due to the malachite green treatment. The possible use of malachite green in the treatment of PKD, tissue levels of malachite green achieved during treatments and the toxicity risks from multiple dose therapy with malachite green are discussed.