Nitrogen fixation and soil nitrogen in organic ley arable rotations

This report was presented at the UK Organic Research 2002 Conference. Nitrogen (N) fixation in a white clover/ryegrass mixture was measured in 1,2,3 and 4-year-old organically managed leys during 2000. N fixation varied between 73.7 in 1-year-old leys and 33.5 kg ha-1 in 4-year-old leys. Soil nitrate-N, grass N yield and N content of grass and clover were all lowest in 2-year-old leys and highest in 3-year-old leys. The proportion of clover nitrogen derived from the atmosphere (pNdfa) was significantly lower in 3-year-old leys

History of the fluids associated with the lode-gold deposits, and complex U-PGE-Au vein-type deposits, Goldfields Peninsula, Northern Saskatchewan, Canada

The varied mineral deposit types of the Beaverlodge area, Northern Saskatchewan, indicate that the rocks have undergone a complex and protracted fluid history. All of the deposits studied are physically hosted in a variably metamorphosed sedimentary sequence, the Aphebian-aged Murmac Bay Group (complex Au-PGE-U vein-type deposits, e.g. Nicholson, Fish Hook), or within granites "intrusive" into the Group (lode-­gold deposits, e.g. Box, Athona, Frontier). The complex Au-PGE-U vein-type deposits, and other minor mineralizations, are genetically associated with later, overlying sedimentary sequences such as the Late Aphebian to Helikian-aged Martin and Athabasca Groups. The succession of sedimentary basins was probably controlled by the virtually continuous tectonic evolution of the area prior to, and during, the Thelon-Talston (ca. 2.0 Ga), and Hudsonian (ca. 1.8 Ga) orogenies. The first fluid event identified is F1, which occurred at ca. 1.97 to 1.95 Ga, when the mine granites were formed as nearly in-situ melts in the presence of a "metasomatic" fluid. The origin of the event is attributed to the burial of the Murmac Bay Group, presumably in a subduction-related setting, during the Thelon-Talston orogeny at ca. 2.0 to 1.9 Ga. δ¹⁸O values of the granite minerals indicate an isotopic closure temperature for this event of 550 to 650°C, and that the "metasomatic" fluids may have been related to magmatic activity that occurred at deeper structural levels in the subduction zone. The development of a regional foliation, D1, may have occurred during the earlier stages of this event as well. The Thluicho Lake Group may be the remnants of a turbidite basin that developed in the back-arc area of the subduction zone. The next fluid event documented is that which produced lode-gold quartz vein mineralization, associated with D2 deformation. This event is recorded in the veins by Type I and Ia fluid inclusions, and by the stable isotopic compositions of vein minerals as fluid events F2 and F3 (Which are likely parts of the same overall fluid event). This fluid, at least during the late stage of vein development, is suspected to have been associated with gold deposition, and is indicated to have had minimum temperatures of about 300°C, and minimum pressures of 2.5 to 3.0 kbars. As the fluid was C0₂-bearing, and the inclusion populations appear to indicate pre-­entrapment immiscibility, these temperatures and pressures are trapping conditions. This is confirmed by some stable isotopic fractionations between quartz and chlorite gangue minerals that yield temperatures of 300 to 400°C. The minerals were in equilibrium with a fluid of metamorphic origin. Rb/Sr ages of vein minerals indicate they are at least 1.84 Ga, and probably between 1.855 and 1.84 Ga, suggesting that the D2 folding, and the retrograde metamorphic fluid that likely caused the lode-gold mineralization, were related to uplift during early Hudsonian collision. The source of the retrograde fluids is not clear, but the fluids may have been derived from the dehydration of material that was subducted during the Thelon-Talston orogeny, as the high ⁸⁷Sr/⁸⁶Sr ratios of the vein minerals, as well as feldspar from the Mine granites, imply that F1 to F3 fluids were derived from, or interacted with significantly older (i.e. deeply buried) crustal material. The fluid represented by Type II inclusions is of an uncertain origin, but clearly post-dated the lode-gold veins (1.84 Ga), and pre-dated the Au-PGE-U mineralization (ca. 1.75 Ga?). This fluid event appears to have been regionally extensive, however, and may be related to events in the Beaverlodge area that are thought to have occurred ca. 1.78 to 1.74 Ga, such as regional albitization, or the simple vein-­type uranium deposits. This age of approximately 1.75 Ga is often referred to as the "late overprint", suggested to be related to the later stages of the Hudsonian Orogen. The "late overprint" is also recorded by feldspars from the Box mine granite, which yield an Rb/Sr age of ca. 1.77 Ga. The Martin basin may have started to form at this time, due to epeirogenic fault movement during the waning stages of the Hudsonian Orogen, and this fluid event may also be related to early diagenesis within the basin. The next fluid event, F4, is recorded by primary fluid inclusions in the complex AU-PGE-U vein-type deposits, which contain fluids of a moderately high salinity (28 to 36 wt % NaCl eq.). A similar fluid is found in secondary Type IV inclusions from the lode-gold veins, and in fluid inclusions from the "sponge rock" zones that have locally altered the mine granites. Stable isotopic equilibration temperatures of vein minerals from the Nicholson and Quartzite Ridge deposits indicate that the fluid was at a temperature of 100 to 120°C. The age of this fluid event may be as old as ca. 1.8 to 1.7 Ga, because the depleted δD value of the fluid, at approximately -90 permil, implies a high latitude for the area. The area was only located at the required high latitudes during two periods of time. For this reason, it is possible that Au-PGE mineralization, such as the Nicholson and Quartzite Ridge deposits, may have formed from diagenetic basinal fluids derived from, or influenced by, the Martin basin, or an unrecognized "proto-Athabasca" basin. Whether or not uranium accompanied the gold and platinoids, or was later overprinted on pre-existing Au-PGE mineralization is not presently known. F5 is the youngest fluid event, recorded by the late U­-bearing comb veins. The fluids were of a high salinity (40 wt. % NaCl eq.) , and stable isotopic equilibrium fractionations between vein minerals indicate a temperature of approximately 175°C. The calculated stable isotopic values of the fluid are similar to those of the diagenetic fluids in the Athabasca basin between ca. 1.6 and 1.0 Ga, during which time the unconformity-type and complex vein-type uranium deposits were formed. As mentioned above, this may be the time during which uranium mineralization overprinted the AU-PGE mineralization, forming "hybrid" complex Au-PGE-U vein-type deposits. An early stage of the F5 fluid event is represented by Type III secondary inclusions in the lode-gold veins. The moderate salinity of the fluid (10 to 15 wt. % NaCl eq.) is similar to fluid inclusions observed in quartz overgrowths from the Athabasca basin, where the fluid is interpreted to be of an early diagenetic origin

Health care needs and health policy : the case of renal services.

PhDThis thesis presents a critical ethnography of decision making with respect to the assessment of health care needs in the UK health system. Theories of need, justice and rights are reviewed in relation to structural changes to the National Health Service, together with the different theoretical approaches underpinning health policy based on human needs. The research on which this thesis is based focuses on a case study of an independent review of renal services in London, concentrating on the needs assessment work of the review group set up by the government and the decision making debates this review group engaged in. The methods used are based on a participatory, critical ethnography. The review process is evaluated critically by relating the technical knowledge produced by the group to a theoretical framework for assessing needs and by using a Habermasian perspective to investigate the ways in which the language of need is used to legitimise the agendas of various vested interests. This work is linked with an analysis of quasi-markets in the health service to explore the capacity that the technical discourses of markets and contracting have for reinforcing the ideological distortions identified in the analysis of the group's debates concerning need. Finally, by linking an analysis based on a case study of renal services to theoretical understandings of health care needs and health policy, a general critique of the UK health system is constructed

A REST Model for High Throughput Scheduling in Computational Grids

Current grid computing architectures have been based on cluster management and batch queuing systems, extended to a distributed, federated domain. These have shown shortcomings in terms of scalability, stability, and modularity. To address these problems, this dissertation applies architectural styles from the Internet and Web to the domain of generic computational grids. Using the REST style, a flexible model for grid resource interaction is developed which removes the need for any centralised services or specific protocols, thereby allowing a range of implementations and layering of further functionality. The context for resource interaction is a generalisation and formalisation of the Condor ClassAd match-making mechanism. This set theoretic model is described in depth, including the advantages and features which it realises. This RESTful style is also motivated by operational experience with existing grid infrastructures, and the design, operation, and performance of a proto-RESTful grid middleware package named DIRAC. This package was designed to provide for the LHCb particle physics experiment's âﾜoff-lineâ computational infrastructure, and was first exercised during a 6 month data challenge which utilised over 670 years of CPU time and produced 98 TB of data through 300,000 tasks executed at computing centres around the world. The design of DIRAC and performance measures from the data challenge are reported. The main contribution of this work is the development of a REST model for grid resource interaction. In particular, it allows resource templating for scheduling queues which provide a novel distributed and scalable approach to resource scheduling on the grid

Elite city-deals for economic growth? Problematizing the complexities of devolution, city-region building, and the (re)positioning of civil society

The concept of localism and spatial delineation of the ‘city region’ have seen a renaissance as the de facto spatial political units of governance for economic development. One articulation of this has seen the creation of Cardiff Capital Region (CCR) to potentially enhance Wales’s poor economic performance and secure democratic forms of social cohesion. City regions have been vaunted as the ‘spatial imaginary’ for engendering economic development, but there are considerable state spatial restructuring tensions. The paper discusses these by following the development of city-regionalism in Wales and specifically the unfolding of the ‘elite-led’ CCR City-Deal

Social class, dementia and the fourth age

Research addressing social class and dementia has largely focused on measures of socioeconomic status as causal risk factors for dementia and in observed differences in diagnosis, treatment and care. This large body of work has produced important insights but also contains numerous problems and weaknesses. Research needs to take account of the ways in which ageing and social class have been transformed in tandem with the economic, social and cultural coordinates of late modernity. These changes have particular consequences for individual identities and social relations. With this in mind this article adopts a critical gaze on research that considers interactions between dementia and social class in three key areas: (i) epidemiological approaches to inequalities in risk (ii) the role of social class in diagnosis and treatment and (iii) class in the framing of care and access to care. Following this, the article considers studies of dementia and social class that focus on lay understandings and biographical accounts. Sociological insights in this field come from the view that dementia and social class are embedded in social relations. Thus, forms of distinction based on class relations may still play an important role in the lived experience of dementia

A Study of the Automatic Speech Recognition Process and Speaker Adaptation

This thesis considers the entire automated speech recognition process and presents a standardised approach to LVCSR experimentation with HMMs. It also discusses various approaches to speaker adaptation such as MLLR and multiscale, and presents experimental results for cross­-task speaker adaptation. An analysis of training parameters and data sufficiency for reasonable system performance estimates are also included. It is found that Maximum Likelihood Linear Regression (MLLR) supervised adaptation can result in 6% reduction (absolute) in word error rate given only one minute of adaptation data, as compared with an unadapted model set trained on a different task. The unadapted system performed at 24% WER and the adapted system at 18% WER. This is achieved with only 4 to 7 adaptation classes per speaker, as generated from a regression tree

Connected Growth: developing a framework to drive inclusive growth across a city-region

This ‘in perspective’ piece addresses the (re-)positioning of civil society within new structures of city-region governance within Greater Manchester (GM). This follows on from the processes of devolution, which have given the Greater Manchester City-Region (GMCR) a number of new powers. UK devolution, to date, has been largely focused upon engendering agglomerated economic growth at the city-region scale. Within GMCR, devolution for economic development has sat alongside the devolution of health and social care (unlike any other city-region in the UK) as well. Based on stakeholder mapping and semi-structured interviews with key actors operating across the GMCR, the paper illustrates how this has created a number of significant tensions and opportunities for civil society actors, as they have sought to contest a shifting governance framework. The paper, therefore, calls for future research to carefully consider how civil society groups are grappling with devolution; both contesting and responding to devolution. This is timely given the shifting policy and political discourse towards the need to deliver more socially-inclusive city-regions