Movile Cave is an isolated cave ecosystem that receives no input of photosynthetically fixed carbon. Instead, carbon is primarily fixed through light- independent bacterial processes such as chemolithoautotrophy and methanotrophy. Distinctive microbial floating mats appear at the surface of groundwater flooding the cave, at the redox interface between the oxygenated air above (7-10%) and the anaerobic water below. Methane, of geological origin, bubbles up into the cave and is present in the cave atmosphere (0.5-1%). The in situ methanotroph community of Movile Cave microbial floating mat was determined by examination of metagenomic sequencing and pmoA gene microarray data sets. The metagenonomic sequencing approach indicated a Methylococcus capsulatus -like organism to be the most abundant methanotroph in Movile Cave. pmoA microarray analysis indicated a high abundance of Methylocystis pmoA gene sequences with Methylococcus capsulatus-like pmoA gene sequences being relatively abundant. The methane oxidising bacterium Methylomonas strain LWB was isolated from a sample of lake water from Movile Cave. Phylogenetic analysis of the genes encoding 16S rRNA and the soluble and particulate methane monooxygenase functional gene markers pmoA and mmoX, respectively, confirmed that strain LWB belongs to the genus Methylomonas. Methylomonas LWB has a second putative copy of the particulate methane monooxygenase pXM which displays an unusual gene orientation. The Methylomonas LWB genome contains all genes encoding the typical Type I methanotroph ribulose monophosphate pathway for formaldehyde assimilation and all genes required for a complete TCA cycle. Active methane oxidisers in Movile Cave were identified by DNA Stable-isotope probing. Organisms belonging to the genera Methylomonas, Methylocystis, Methylococcus and Methylobacter- were identified from 13C-enriched DNA. Cross-feeding of the 13C label into non-methanotrophic organisms identified from the 13C-enriched DNA indicated that methanotrophs provide a carbon source for other microorganisms in Movile Cave.

Upland headwater streams are important sources of freshwater in mountainous temperate to sub-arctic latitude European countries like Scotland. Yet much less is known about the ecology of small, characteristically oligotrophic, mountain streams supporting periphyton and aquatic bryophyte dominated vegetation, and their potential bioindicator capacity of environmental water quality, than lowland rivers impacted by anthropogenic disturbance, in this context. This scarcity of knowledge has significant implications for the success of the recently implemented Water Framework Directive (WFD: 2000/60/EC). The WFD is a major piece of environmental legislation for water policy and sustainable water management in Europe. New contributions are fundamental to environment agencies, such as the Scottish Environment Protection Agency (SEPA), tasked with the responsibility of enforcing WFD statutory requirements and developing effective biomonitoring tools for assessing water quality status in Scotland. A major aim of the WFD is to achieve at least ‘good’ ecological status of inland waterbodies by 2015. Further, in doing so, to ascertain ecological benchmark communities of near-pristine (or minimally-impacted) reference conditions as indicators of high water quality status. The objective is to improve understanding of the environmental processes driving the production and diversity of freshwater plant species-assemblages in upland streams. Such information can be used for assessing perturbations threatening the ecological integrity of rivers impacted by anthropogenic disturbances (human pressure). This enables environment agencies such as SEPA, to respond appropriately by implementing corrective measures and sustainable management strategies. This project monitored a range of near-pristine headwater streams of contrasting underlying geology in the Scottish Highlands. The approach adopted was compatible with current WFD river characterisation and biomonitoring strategies. These were used to investigate the structural and functional response of freshwater plant communities (chiefly diatoms and other algal groups; aquatic bryophyte and vascular submerged macrophyte vegetation) to environmental drivers (e.g. flow, substrate morphology, nutrient inputs, water chemistry, underwater light availability). The work was carried out with the aim of contributing to future development of baseline monitoring tools for assessing upland stream habitat quality in Scotland.

No description available.

Ordovician samples have been collected from various places from within three separate terranes in Scotland; the Highland Border Complex, the Southern Uplands and the Midland Valley. The samples have been palynologically processed and their assemblages studied with the aim of understanding some of the palaeoecological, biostratigraphical and thermal relationships of the three areas.Seventy one samples have been processed from nine localities of the Highland Border Complex and these have yielded fifteen species of chitinozoans in four genera, as well as indeterminate species of those genera. There are also five species of acritarchs in four genera as well as other microfossils. Black shales from the Complex yield the most diverse palynomorph assemblages, and were probably deposited from Arenig through to Caradoc although not necessarily at the same time in different parts of the basin. The preservation of palynomorphs appears to be better in the west of Scotland than in the east.From the Southern Uplands samples have been processed from Coldingham Bay and proved barren, from Barrhill the assemblages are poor, but from the Ordovician-Silurian bondary beds (C. peltifer to P. acuminatus Zones) at Dob's Linn they are quite diverse although abundance is very low, with forty three samples yielding thirty three species of acritarchs in eighteen genera, thirty one species of chitinozoans in thirteen genera and various other microfossils. The boundary cannot be delineated using the palynological assemblages, and although Tylotopalla sp. A and Ancyrochitina ancyrea Eisenack 1931 are common in most of the samples from the boundary the palynomorphs do not appear to mirror the changes that occur in the graptolite assemblages.From the Midland Valley samples have been processed from eight miscellaneous localities in the region of Girvan, giving very little biostratigraphical data, although one sample from Doularg Hill is dated as upper Arenig to lower Llanvirn. A section of twelve samples processed from the Mill and Shalloch Formations (D. complanatus and D. anceps Zones) at Woodland Point, Girvan, has yielded thirty five species of chitinozoans in twelve genera including a new species Angochitina woodlandensis and five new combinations; Belonechitina comma (Eisenack 1959), Belonechitina hirsuta (Laufeld 1967). Belonechitina micracantha (Eisenack 1931), Belonechitina schopfi subsp. americana (Taugourdeau 1965), and Belonechitina seriespinosa (Jenkins 1969). There are also forty seven species of acritarchs in twentyone genera, including two new species; Actinotodissus woodlandense, and Goniosphaeridium girvanense, and many scolecodonts. Spores are common and three species are recognised at Woodland Point. The samples are dated as Upper Ordovician and Calpichitina lenticularis (Bouche 1965) and Acanthochitina barbata appear to be important Upper Ordovician indicators, possibly being near-shore species as they are not found in rocks of the same age at Dob's Linn. Calpichitina lenticularis is very important in one sample and less so in all the others and it is suggested that it may be reworked. The palaeoecological picture at Woodland point shows an offshore situation in the Mill Formation, becoming more near-shore at the base of the Shalloch Formation and then more off-shore again.The palaeoecology of both Dob's Linn and Woodland Point are discussed and chitinozoans found to be more common in black shales than grey mudstones, although the acritarchs do not appear to be preferentially found in grey mudstones or black shales. Netromorph acritarchs are less common at Dob's Linn than was expected, but are very common at Woodland Point which may suggest that the sediments at Woodland Point were deposited more offshore than those at Dob's Linn but were more greatly influenced by turbiditic material. Sphaeromorph acritarchs at Woodland Point are very common and due to the variable thickness of the walls it is suggested that there is a mixing of near-shore and off-shore species, possibly by the turbiditic action mentioned above. Belonechitina is markedlymore important at Woodland Point than at Dob's Linn the reverse of which is true with Cyathochitina . The suggested reason for this is that Belonechitina is a near-shore species whilst Cyathochitina is an off-shore species. Veryhachium appears to become more important towards the end of the Ordovician, as a sample each from Woodland Point and Dob's Linn contain three species of this relatively rare genus, although the significance of this is not yet known.The sample from Dob's Linn and Woodland Point are compared with published works using the jacquard Coefficient and the results presented. The samples at Dob's Linn are compared with the Ordovician-Silurian boundary sediments elsewhere, and although different species are present at Dob's Linn and on Anticosti Island, and the abundance and diversity is lower at Dob's Linn, the boundary in Scotland has a much better palynomorph assemblage than was expected. The boundary assemblage presented here is quite similar to the one in Skane, Sweden.Finally the thermal history of the samples is discussed, and a general trend appears, with the samples from Girvan being the least altered, those from the Southern Uplands being moderately altered and finally the Highland Border Complex samples which have been subjected to temperatures probably between 200 and 300oC, and thus strongly altered.

Empirical and theoretical investigations of aspects of the ideal free distribution (IFD) are presented, with particular emphasis on interactions between individuals within foraging groups. An overview of the theory is presented, and the implications of the work included in this thesis to ideal free distribution theory are discussed. The effect of group size on the relative competitive ability of individual fish within a foraging group is shown to be dependent upon the difference in body size between two focus individuals in a group, but this difference itself has no direct effect on relative competitive ability. A subsequent empirical test of a novel mathematical tool reveals that there is no simple general rule for describing how relative competitive ability will change with group size, and that very specific knowledge of the system under study is needed in order to produce robust predictions. The relative abilities of individual chiclids to obtain food under scramble competition are shown to be highly repeatable between trials. However, when given a choice between two patches differing only in their temporal variability in input about an identical mean, an individual's rank based on intake in one patch was uncorrelated with either its uptake in the other patch or its intake in either of two different trial types. The basis for, and consequence of, this dependence of relative competitive ability on the context of the foraging situation are discussed. The general case (previously unexposed in the literature) where the effect of interference can vary between patches is examined. Simulations from an individual-based model reveal a decrease in the number of stable equilibrium distributions as the competitive advantage of the dominant phenotype declines in one patch, leading eventually to a single stable equilibrium, in which both phenotypes are found on both patches.

The work reported in this thesis is divided into 3 main sections as follows. Section 1. The external morphology of byssus threads produced by Mytilus edulis and Modiolus modiolus was studied by scanning electron microscopy. Section 2. Several laboratory experiments were performed to determine how sediment with stones at different layers and of different particle size ranges affects byssus thread production. These experiments were: (i) An initial experiment to determine the rate of byssus thread production. (ii) The response of single animals and groups of animals to different particle size ranges of sediment. (iii) The response of single animals and groups of animals to experimental sediments (particle size range < 2.0cm) with stones present or not present at different depths. Section 3. Experiments were performed to determine the effects of single animals and groups of animals on sediment stability. All experiments were performed under controlled conditions in an experimental sea water flume. These experiments were: (i) the effects of single animals on sediment stability in different particle size ranges of sediment. (ii) the effects of groups of animals on sediment stability in different particle size ranges of sediment. (iii) the effects of groups of animals on sediment stability in sediment of particle size < 2.00mm, with stones present or not present at different depths.

No aInitially, the thesis investigated the ecological energetics of N. norvegicus in order to construct an energy budget which could be used to estimate scope for growth. The diet of the Norway lobster Nephrops norvegicus in the Firth of Clyde was found to consist of crustaceans, molluscs, and to a lesser extent polychaetes and echinoderms. The proportion of bivalves was higher in the diet of N. norvegicus from south of Little Cumbrae than in the diet of N. norvegicus from south of Ailsa Craig which contained larger proportions of crustaceans and echinoderms. This appears to reflect the faunal composition of the areas. Despite a number of measures taken to preserve stomach contents, a large proportion of the diet was found to be macerated beyond recognition, particularly in the stomachs of animals from the south of Ailsa Craig stocklet. There were marked interspecific differences in the energy contents and organic contents of prey organisms. The calorific values of the prey items were found to vary according to the proportion of organic matter in the tissue. Organisms with low organic contents such as brittle stars had lower calorific values than organisms with a large organic proportion such as soft-bodied polychaetes. Amounts of food consumption were calculated in 4h intervals over a 24h period. Results suggested that foraging is highest during the night at 2200-0200. A smaller increase in food consumption was also noticed during the morning at 0600-1000 and 1000-1400. The lowest amount of food was consumed between 1400-1800. Two different models were used to estimate the daily amounts of food consumption. The values obtained ranged from 476.5mg day-1 (wet weight) at Ailsa Craig in November to 1206.2 mg day-1 (wet weight) at Little Cumbrae in May.

The work in this thesis shows that it is possible to design a diffusion cell which will allow access to the flux and lag time of a permeant without the need for invasive sampling and that this novel cell is both sensitive and reproducible. It was also shown that the cell could be used in conjunction with both simple model membranes and more complex biological membranes, namely the epidermis. From the data achieved from the cell it was possible to derive a series of equations which allowed access to thermodynamic parameters such as ?H, ?G and ?S. An extension of this calculational approach revealed that manipulation of the van’t Hoff isochore, under the condition where enthalpy is constant over the temperature range, it should be possible to calculate the partition coefficient. Ultimately these parameters can be used in the description of structure activity relationships. The systems described in this thesis are of a complex biological nature consequently the returned data reflect this complexity. In order to utilise the data to their full potential some method for dealing with this complexity was sought. One approach widely discussed in the literature is that of chemometric analysis or soft modelling. Initial studies into the use of chemometric analysis proved positive for the data presented in this thesis, and suggested that formulation contributions from components with close absorbance maxima could be separated.

No description available.

The present work, employing biochemical, biophysical and electrophysiological techniques, attempted to identify specific receptor sites in the vertebrate olfactory system for heterocyclic odorants. An in vitro rat preparation was developed and characterised for use in vapour-phase chemical modification experiments; the EOG responses obtained from this preparation were stable for up to 5 hours after the death of the animal. The signals to various compounds were differentially reduced when brominated odorants were employed as vapour-phase labelling reagents; the responses obtained to these derivatives and to their non-reactive analogues were preferentially diminished. The effect of concanavalin A on ECGs obtained from an in vivo frog preparation was examined. This lectin was found to preferentially inhibit the signals elicited by small, sweaty-smelling carboxylic acids; the responses to most of the non-carboxylic acid odorants tested were not significantly inhibited. The failure to identify specific receptor sites by electrophysiological techniques prompted the performance of odorant binding studies. Examinations of the interaction of [3H] 2-isobutyl-3- methoxypyrazine with 13,000 x g supernatant fractions of sheep olfactory epithelium showed that a component of the homogenate fraction exhibited high affinity saturable binding of this odorant (KD-10-8M). However, the presence of large amounts of non-specific binding, substantially decreased the sensitivity and accuracy of the assay. Non-specific binding was observed with tissue fractions of sheep respiratory epithelium, brain and liver. An investigation of binding specificity showed that other bell pepper odorants competed for the 2-iscbutyl-3-methoxypyrazine binding site. The steno requirements for the protein binding of various substituted heterocyclic odorants were examined using nuclear magnetic relaxation techniques. Model studies performed with bovine serum albumin showed that particular side chains of the odorants tested were primarily involved in the binding interaction. The methoxy group of 2-isopropyl-3-methoxypyrazine was found to be responsible for primary recognition by 13,000 x g supernatant fractions of sheep olfactory epithelium.