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Summary Aims A prospective observational study was conducted in Royal Marines (RM) recruits to investigate throat carriage of group A Streptococcus (GAS) and incidence of soft tissue infections. Methods 1012 RM recruits were followed through a 32-week training programme, with throat swabs being obtained in weeks 1, 6, 15, and 32. Alongside a separate cohort of 46 RM Young Officers (YO) undergoing training were sampled in parallel. Results Carriage of group A Streptococcus was detected in only 5/1012 (0.49%) recruits at the beginning of training and remained low throughout training. There was no association between GAS carriage and development of soft tissue infection. There was no carriage of GAS in the smaller YO cohort at the start of training, (0/46). At week 6, a surge in GAS carriage was detected in 8/46 (17%) YO, that could be ascribed to a cluster of GAS genotype emm 83. Conclusions Asymptomatic GAS carriage is very infrequent among young adults in England and this should be borne in mind when considering the relevance of a positive throat swab result in symptomatic patients or outbreaks. Despite low prevalence, there is however potential for GAS to rapidly and transiently disseminate among adults during outbreaks.

The physiology of yield determination in asparagus (Asparagus officinalis L.) is complex. Above-ground growth of spears and ferns is the ultimate indicator of performance. However, growth is driven by soluble carbohydrate (CHO), which has a well-known pattern of gain and loss in the storage root system during the crop’s annual cycle. Root CHO content is a better performance indicator, now that the relationship between above-ground growth and CHO changes is better understood. Recent research has improved the definition of the root CHO pattern, and of benchmark CHO contents at key times during the growth cycle. Detection of deviations from the ‘ideal’ pattern can help with early diagnosis of problems. The research has also led to a simple method for assessing the CHO content of roots and to an internet-based system for delivering interpretations of CHO content data. Together, these components constitute the Aspire decision support system. In this paper we review this research. In particular, we explore four topics that are crucial for the viability of the concept: (a) evaluate whether Brix% of root sap can be used as a surrogate for analytical root CHO content; (b) compare root CHO content patterns in different countries, with different climates and management systems; (c) analyse the significance of root system size; and (d) analyse the physiological capacity of crops to produce CHO during fern growth. We conclude that, provided the implications of these factors are recognised, the approach can deliver benefits to asparagus growers. The Aspire system is becoming available to increasing numbers of growers around the world. Already it is being used by growers in New Zealand and North America, supporting them in making management decisions to improve yields and the long-term sustainability of their crops.

Gruner kale showed a linear increase (8.0 kg DM/ha per °Cd) in biomass with sowings on 1 October, 3 November and 1 December producing 23, 19 and 17 t DM/ha (respectively) by the 29 May. Regrowth following mid season defoliation was slow (5.3 kg DM/ha per °Cd) reducing total production (relative to undefoliated) by 7.5 and 5.5 t DM/ha for treatments defoliated on the 29 January and 14 March, respectively. Keyworks: defoliation, kale, quality, regrowth, sowing date, thermal time, yield

Fertiliser management is an important aspect of growing good forage brassica crops. Every crop has a different requirement, depending on soil fertility and the expected yield response. Systems were developed for forecasting how much fertiliser, and what types, to apply to individual kale and Pasja crops. First, yield responses to fertiliser application were measured in trials in diverse climates and soil fertility conditions. Yield responded strongly to N and P availability, there were few responses to K fertiliser application, and there were no responses to S application. Second, overall responses to the nutrient supply from soil and fertiliser sources were determined in a comprehensive across-trials analysis using the PARJIB model. R-squared values for correlations between actual yields and yields simulated with the PARJIB calibrations were 0.65 and 0.64 for Pasja and kale respectively. Finally, the results were programmed into new software systems (The Kale Calculator and The Pasja Calculator) that deliver a forecast for each crop of the types and amounts of fertiliser that will give the best economic return on the investment in fertiliser. Keywords: The Kale Calculator, The Pasja Calculator, fertiliser application, yield response, PARJIB analysis

This paper tests PARJIB, a simple but powerful model to analyse and forecast yield responses to nutrients in annual crops. The model was calibrated for maize using data obtained under a very wide range of conditions in New Zealand from 1996 to 1999. The calibration process used a genetic algorithm technique. After a preliminary calibration using about half of the available data and only one cultivar, the model performed well, accounting for 66–73% of the observed yield variation in independent datasets that included five cultivars. When simulating the test datasets, the largest errors were associated with one long-season cultivar. The model was then recalibrated against all available data. That dataset spanned five cultivars, four regions of New Zealand, a wide range of soil and weather conditions, and a range of fertiliser application treatments. Grain yields varied from 4 to 18 t/ha. The root mean square (RMS) error of calibration was 0.92 t/ha (9.3%), and the model accounted for 83% of the observed variation in yield. We checked various model predictions against previously published results, and found good agreement. The model indicates strong interactions between water stress, plant population and the need for nutrients. The PARJIB model has substantial potential to aid growers in fertiliser decisions, and to assist researchers in the analysis and interpretation of field experiments.

Lysimeters located outdoors have been used to evaluate the decomposition of buried oily beach sand waste (OBS) prepared using Forties light crude oil and sand from different locations around the British coast. The OBS (5% oil by weight) was buried as a 12-cm layer over dune pasture sub-sand and overlain by 20 cm of dune pasture topsoil. Decomposition rates of oil residues averaged 2300 kg ha(-1) in the first year and the pattern of oil decomposition may be represented by a power curve. Oil decomposition was strongly related to the temperature in the OBS layer, but was also significantly affected by rainfall in the previous 12 h. The CO(2) flux at the surface of the treatment lysimeters followed the relationship [log(10) CO(2) (mg C m(-2) h(-1))=0.93+0.058x OBS temp. (degrees C)-0.042x12 h rain (mm)]. There was considerable variation in the rate of oil decomposition in sands collected from different sites. Sand from Askernish supported most microbial activity whilst sand from Tain was relatively inactive. The decomposition process appeared to cease when the sand became saturated with water, i.e. temporarily anaerobic. However, decomposition recommenced when the soil dried out. The fastest rate of decomposition occurred in sand from one of the two sites predicted to have high populations of hydrocarbon-degrading bacteria. Larger particle size and higher Ca content may also be significant factors governing the rate of decomposition.

The principal axis model (PAM) uses a principal axis and an ellipse to characterize the variation in the relationship between the seed (SWT) and plant (PWT) weights of individual plants within a crop. The theoretical linkage between the magnitude and variability of plant harvest index (PHI), and therefore seed yield per unit area, and changes in the components of the PAM was examined using data from four field pea (Pisum sativumL.) genotypes sown at 9, 49, 100, 225 and 400 plants m-2. A strong linear relationship (R2>93.8%) between SWT and PWT and a negative SWT-axis intercept were confirmed for all crops. Analyses indicated that decreased variability of PHI within a crop would result from selection to: (a) increase the SWT-axis intercept of the PAM; (b) increase the slope of the PAM; (c) optimize the ellipse location; and (d) minimize the deviation around the principal axis. The first three methods were used to explain yield differences (P

This paper investigates the effect of the physical location of the auxiliary source of energy in thermosyphon solar water heaters and shows that the performance of the system can be optimised with respect to the geometry of the system components. The investigation has been based on a domestic thermosyphon solar water heating system, which was simulated using the TRNSYS programme. The annual solar fraction of the system, at the weather and socioeconomic conditions of Cyprus, is, at best, approximately 77% with an in-tank auxiliary heater configuration and 86% with an external auxiliary heater. It is demonstrated that the arrangement with the external auxiliary unit has a higher collector efficiency and results in a higher annual solar fraction. In the case of in-tank auxiliary, the system performance increases with the height of the auxiliary position from the bottom of the storage tank ; with the auxiliary at the bottom of the storage tank the annual solar fraction is approximately 59%, compared to 77% when the auxiliary is located at the top of the tank. The system performance also depends on the height of the collector return from the bottom of the tank.

In cool-temperate climates, potential maize grain yields are variable and often small. Low temperature prolongs growth duration, reduces crop growth rate, and increases the risk of frost terminating grain filling prematurely. The objectives of this study were (1) to assess the performance of a radiation- and temperature-driven maize simulation model in a cool-temperate climate and (2) to modify the model to allow the effects of temperature and solar radiation on growth and yield to be simulated in both warm and cool climates. Modifications to the model to improve simulation in the cool climate included a changed phenology response to low temperature, a reduction in radiation-use efficiency and rate of harvest index increase at low temperature, and an increased time lag between silking and the start of grain growth at low temperature. The modified model gave good agreement between observed independent datasets and simulated values of grain and total biomass yield in tropical, subtropical and cool-temperate locations; root mean square deviations of the comparisons averaged across all locations were about 12% of the mean values. Thus the utility of the model has been enhanced for a wider range of climates. The study also showed that the conclusion from previous analyses with the model in warm climates that the highest potential maize yields occur at locations with a combination of high incident radiation, low temperature and long growth duration may not be valid if mean temperature during growth is less than ca. 18°C. However, this condition would only occur in cool-temperate climates.

A barley crop grown under an automatic rainout shelter was subjected to varying timings and durations of water stress to develop a range of timings and severities of drought. Considerable variation in water use among treatments was induced. The control treatment was irrigated each week to replace the previous week's evapotranspiration (Ea). Other treatments had irrigation withdrawn for varying periods either from emergence (early drought) or from 3 weeks before anthesis (middle drought), or from varying times from before anthesis to mid-grain fill until maturity (late drought). Maximum measured soil moisture deficits in the top metre varied from 105 to 208 mm, and seasonal Ea from 434 to 210 mm. Reductions in Ea below the control between 10 October to 10 January varied from 11 to 40%. Reductions in transpiration were generally larger than this because reduced ground cover in stressed treatments led to increases in soil evaporation. In contrast to other studies, a greater proportion of the decrease in transpiration was caused by increased stomatal resistance than by reduction of leaf area. A soil evaporation and transpiration model was used as an aid to data analysis. Data were fitted to a simple model that assumed transpiration was unlimited by water deficits until these exceeded 65% of the available water holding capacity of the root zone. This provided a good description of the transpiration process either when water was unlimiting or when deficits occurred late in crop development. However, when moderate to severe drought occurred before anthesis, reductions in transpiration were much larger than the model could account for, and persisted for up to 2 weeks after drought was relieved. The decline in transpiration was associated either with irreversible changes to leaves or with the time taken for the root system to recover.

The rate of leaf appearance in wheat depends on temperature. When the rate is expressed in thermal time based on air temperature, a marked contrast is apparent between autumn and spring sowings. This variation has often been attributed to a preconditioning response that determines the thermal phyllochron at about the time of emergence, either directly through an effect of daylength or its rate of change. However, in this paper we show that invoking such a response is unnecessary. Leaf appearance rate was found to be well predicted based only on temperature near the apical meristem (near-surface soil temperature until stem extension began, then canopy temperature) and leaf number. It was not necessary to include a response to daylength or its rate of change. A model of leaf appearance based on estimates of near-surface soil temperature and canopy temperature gave superior predictions than others based on air temperature alone or modified by rate of change of daylength.

Neuromodulation therapies have seen a recent resurgence in the treatment of psychiatric disorders. These range from the time-tested electroconvulsive therapy (ECT) to promising innovative techniques such as transcranial magnetic stimulation (TMS), vagal nerve stimulation, deep brain stimulation, and magnetic seizure therapy. In the following sections, we briefly discuss the important aspects of ECT and TMS.

Comparison of crop simulation models is rare but necessary pre-requisite for their use and improvement. The wheat crop simulation models Afrcwheat2 , Ceres -Wheat and Swheat were tested against data from five closely monitored experiments on cvs Avalon and Rongotea using weather data from Lincoln, New Zealand for 1984, 1985, and 1986. There was a single sowing date in 1984 and 1985, and three sowing dates in 1986. Sufficient irrigation water and nitrogen fertiliser were applied each year not to limit crop productivity. Afrcwheat2 was the most accurate predictors of development. With this model, average root mean square differences over all growth stages until anthesis were 5.8 days for cv. Avalon and 7.6 days for cv. Rongotea, but 10.4 days and 15.8 days respectively using Ceres -Wheat. Swheat had an average error of 26.4 days for cv. Rongotea. Interception of photosynthetically active radiation (PAR) was modelled with reasonable accuracy for both varieties for all sowings by afrcwheat2 , except or an over-estimation of the rate of decline in green leaf area following anthesis. Conversely, Ceres -Wheat often overestimated the proportion of PAR intercepted before anthesis but was usually closer than Afrcwheat2 for the rest of the season for Avalon. Afrcwheat2 described PAR interceptance better than did the other models for cv. Rongotea except for late sowing in 1986 for which no model performed especially well. Total dry matter increase was best predicted by Afrcwheat2 for both varieties. Ceres -Wheat predicted Avalon final yields better than did Afrcwheat2 . Averaged over the five crops, the absolute error in prediction grain yield in Avalon by Ceres -Wheat was 12% of that observed whilst that for Afrcwheat2 was 15%. For cv. Rongotea, the Afrcwheat2 error was 14%, but that with Ceres -Wheat was 29%. Swheat predictions were low by an average of 40%. Simulation of other components of grain yield was more satisfactory for cv. Rongotea than for cv. Avalon. For the circumscribed range of non-limiting experimental conditions examined, Afrcwheat2 and Swheat underestimated leaf area during its decline folloing anthesis, and this was reflected in underestimation of biomass production during this phase. The errors in estimation of grain dry mass, grain number and final shoot number were inconsistent with respect to both variety and model. The chief improvement with Swheat is in simulation of crop phenology. Improvements in the estimation of PAR interceptance by Ceres -Wheat and Afrcwheat2 are required at different times during the crop growing cycle.

Globally, the common channel Signaling System No.7 (SS7) has grown and matured over the past five years in two directions. Outside of the US, the development of CCITT Signaling System No.7 (C7) has grown largely due to the need for modern call completion capabilities in national telephone networks. Within the US, SS7 has evolved from the need to provide fast and reliable database services to the support of the custom calling features to the local exchange carrier (LEC) networks. The 1990s will further accelerate the requirements for network solutions to customer needs, especially in the rapidly growing cellular telephony industry. These network solutions are forcing the merger of call delivery and database services in both the SS7 and C7 worlds. The issues, concerns, and difficulties with the merger of these functions are discussed. >

The instantaneous collector-efficiency has been determined as a function of the time of day and correlated with the thermosyphonic-flow rate of water and the temperature difference between the water at the collector's inlet and outlet. The model was also used to predict the monthly and yearly solar-contribution of the system for two different load profiles. The results of the simulation indicate that the yearly solar contribution of the system for a low-consumption profile is about 89% as compared with 63% for a high consumption pattern.

This paper investigates the dynamic characteristics of a residential heat-pump system during start-up conditions. Cyclic tests were performed to simulate the operating conditions that are likely to be encountered in heat-pump installations in the UK, where operation is restricted to the heating mode only. The heat pump used is of the split-type air-to-water design and is equipped with a fully hermetic reciprocating compressor and a thermostatic expansion valve with maximum operating pressure characteristics. The results suggest that the cyclic losses associated with refrigerant migration during the off cycle and the employment of a suction accumulator represent a 5% and 4% respective decrease in the system COP when compared with the case where refrigerant migration was controlled.

ARCWHEAT1 is a computer model which simulates the growth and development of wheat (Triticum aestivum L.) crops without water or nutrient limitations. Previously, it had been calibrated and tested for crops in the UK and western Europe. This paper presents the results of a more rigorous validation in which predictions from the model were compared with measurements on crops grown at three locations in New Zealand, during three seasons, under conditions of optimum water and nutrients. The conditions of the experiments were outside the model's development and calibration range. Simulation of phenological development, Par interceptance, Par -use efficiency and above-ground dry matter production was very good, with root means square deviations ( RMSD ) of simulations from observations of less than 10%. Simulation of grain growth and yield was only fair, with RMSDs between 20 and 30%. Predictions of final shoot number, grain number and mean grain biomass were poor. The model validation exercise has highlighted areas where further research is needed to provide definitive descriptions of the response of wheat crops to their environments.

This paper reviews the application of solar energy technology in Cyprus and presents an energy analysis with emphasis on the contribution of solar energy to the energy consumption in the island. The almost full reliance of Cyprus on imported oil to meet its energy demand, together with the abundance of solar radiation and a good technological base, created favourable conditions for the exploitation and development of solar energy in the island. Cyprys began manufacturing solar water heaters in the early 1960s and today it produces more than 30,000 m 2 of solar collectors yearly. It is estimated that more than 130,000 solar water heaters are in operation providing the equivalent of 9% of the total electricity consumption in the country; this corresponds to, approximately, 4% of the national energy consumption. However, the use of solar energy for space heating and cooling provides a further challenge, because it does not appear to be economic under the climatic conditions and system design practices currently prevailing in Cyprus. The paper provides a statistical analysis of the energy demand and identifies areas of further growth for solar energy technology.

The most critical component of a protection, control, and monitoring system is the auxiliary DC control power system. Failure of the DC control power can render fault detection devices unable to detect faults, breakers unable to trip for faults, local and remote indication to become inoperable, etc. The auxiliary DC control power system consists of the battery, battery charger, distribution system, switching and protective devices, and any monitoring equipment. Proper sizing, design, and maintenance of the components that make up the auxiliary DC control system are required. Many references for stationary battery system design address only a specific battery technology, making it difficult to compare different types of batteries for their overall suitability to substation application. Also, most references do not address the particular requirements of the electrical substation environment and duty cycle. This paper provides an overall review of things to consider in designing the auxiliary DC control power system for an electrical substation

Multilayer backpropagation, like most learning algorithms that can create complex decision surfaces, is prone to overfitting. We present a novel approach, called lazy training, for reducing the overfit in multiple-layer networks. Lazy training consistently reduces generalization error of optimized neural networks by more than half on a large OCR dataset and on several real world problems from the UCI machine learning database repository. Here, lazy training is shown to be effective in a multilayered adaptive learning system, reducing the error of an optimized backpropagation network in a speech recognition system by 50.0% on the TIDIGITS corpus.

Neural network and machine learning algorithms often have parameters that must be tuned for good performance on a particular task. Leave-one-out cross-validation (LCV) accuracy is often used to measure the fitness of a set of parameter values. However, small changes in parameters often have no effect on LCV accuracy. Many learning algorithms can measure the confidence of a classification decision, but often confidence alone is an inappropriate measure of fitness. This paper proposes a combined measure of cross-validation and confidence (CVC) for obtaining a continuous measure of fitness for sets of parameters in learning algorithms. This paper also proposes the refined instance-based learning algorithm which illustrates the use of CVC in automated parameter tuning. Using CVC provides significant improvement in generalization accuracy on a collection of 31 classification tasks when compared to using LCV.

A relaxation network model that includes higher order weight connections is introduced. To demonstrate its utility, the model is applied to the speech recognition domain. Traditional speech recognition systems typically consider only that context preceding the word to be recognized. However, intuition suggests that considering both preceding context as well as following context should improve recognition accuracy. The work described here tests this hypothesis by applying the higher order relaxation network to consider both precedes and follows context in speech recognition. The results demonstrate both the general utility of the higher order relaxation network as well as its improvement over traditional methods on a speech recognition task.

Constraint satisfaction networks contain nodes that receive weighted evidence from external sources and/or other nodes. A relaxation process allows the activation of nodes to affect neighboring nodes, which in turn can affect their neighbors, allowing information to travel through a network. When doing discrete updates (as in a software implementation of a relaxation network), a goal net or goal activation can be computed in response to the net input into a node, and a relaxation rate can then be used to determine how fast the node moves from its current value to its goal value. An open question was whether or not the relaxation rate is a sensitive parameter. This paper shows that the relaxation rate has almost no effect on how information flows through the network as long as it is small enough to avoid large discrete steps and/or oscillation.

There are many ways for a learning system to generalize from training set data. There is likely no one style of generalization which will solve all problems better than any other style, for different styles will work better on some applications than others. The authors present several styles of generalization and use them to suggest that a collection of such styles can provide more accurate generalization than any one style by itself. Empirical results of generalizing on several real-world applications are given, and comparisons are made on the generalization accuracy of each style of generalization. The empirical results support the hypothesis that using multiple generalization styles can improve generalization accuracy. >

Radial basis function (RBF) networks typically use a distance function designed for numeric attributes, such as Euclidean or city-block distance. This paper presents a heterogeneous distance function which is appropriate for applications with symbolic attributes, numeric attributes, or both. Empirical results on 30 data sets indicate that the heterogeneous distance metric yields significantly improved generalization accuracy over Euclidean distance in most cases involving symbolic attributes.

In order to be useful, a learning algorithm must be able to generalize well when faced with inputs not previously presented to the system. A bias is necessary for any generalization, and as shown by several researchers in recent years, no bias can lead to strictly better generalization than any other when summed over all possible functions or applications. The paper provides examples to illustrate this fact, but also explains how a bias or learning algorithm can be "better" than another in practice when the probability of the occurrence of functions is taken into account. It shows how domain knowledge and an understanding of the conditions under which each learning algorithm performs well can be used to increase the probability of accurate generalization, and identifies several of the conditions that should be considered when attempting to select an appropriate bias for a particular problem.

In gradient descent learning algorithms such as error backpropagation, the learning rate parameter can have a significant effect on generalization accuracy. In particular, decreasing the learning rate below that which yields the fastest convergence can significantly improve generalization accuracy, especially on large, complex problems. The learning rate also directly affects training speed, but not necessarily in the way that many people expect. Many neural network practitioners currently attempt to use the largest learning rate that still allows for convergence, in order to improve training speed. However, a learning rate that is too large can be as slow as a learning rate that is too small, and a learning rate that is too large or too small can require orders of magnitude more training time than one that is in an appropriate range. The paper illustrates how the learning rate affects training speed and generalization accuracy, and thus gives guidelines on how to efficiently select a learning rate that maximizes generalization accuracy.

We have examined the effects of a replication-defective adenovirus encoding p53 (RPR/INGN 201 [Ad5CMV-p53]; Adp53), alone or in combination with the breast cancer therapeutic doxorubicin (Adriamycin), to suppress growth and induce apoptosis in breast cancer cells in vitro. We have also examined the in vivo effect of intratumoral administration of Adp53, alone or in combination with doxorubicin, to suppress the growth of established subcutaneous MDA-MB-435 breast cancer tumors. Finally, using the MDA-MB-435 orthotopic model of metastatic breast cancer, we have examined the effect of systemic administration of Adp53, alone or in combination with doxorubicin, to reduce the incidence of metastases. We find that whereas in vitro treatment of cells with Adp53 reduces [(3)H]thymidine incorporation by about 90% at 48 hr, cell viability at 6 days is reduced by only some 50% relative to controls. Although apoptosis is detectable in Adp53-treated cultures, these results suggest that a large fraction of Adp53-treated cells merely undergo reversible cell cycle arrest. Combined treatment with Adp53 and doxorubicin results in a greater than additive loss of viability in vitro and increased apoptosis. In vivo, locally administered Adp53 suppresses growth of established subcutaneous tumors in nude mice and suppression is enhanced by doxorubicin. In the metastatic breast cancer model, systemic administration of Adp53 plus doxorubicin leads to a significant reduction in the incidence of metastases relative to Adp53 or doxorubicin alone. Taken together, these data indicate an additive to synergistic effect of Adp53 and doxorubicin for the treatment of primary and metastatic breast cancer.

Probabilistic neural networks (PNN) typically learn more quickly than many neural network models and have had success on a variety of applications. However, in their basic form, they tend to have a large number of hidden nodes. One common solution to this problem is to keep only a randomly selected subset of the original training data in building the network. This paper presents an algorithm called the reduced probabilistic neural network (RPNN) that seeks to choose a better than random subset of the available instances to use as center points of nodes in the network. The algorithm tends to retain non-noisy border points while removing nodes with instances in regions of the input space that are highly homogeneous. In experiments on 22 datasets, the RPNN had better average generalization accuracy than two other PNN models, while requiring an average of less than one-third the number of nodes.

Abstract A number of wells in the Scott Field produce relatively high levels of hydrogen sulphide gas (H2S). The H2S is partially removed from the export gas before it enters the export pipeline system. Offshore experience on Scott has shown that directly injected liquid non-regenerable scavenger remove H2S from the gas with significant operational, environmental and cost benefits compared to a zinc oxide (ZnO) removal method. Following field trials, scavenger was implemented as the sole H2S removal method. This has reduced the chemical cost of export gas H2S treatment on Scott by over 70%, significantly cutting the overall field operating expenditure. Introduction The Scott Field is located in Blocks 15/21a and 15/22 of the U.K. Sector of the North Sea, some 110 miles North East of Aberdeen on the Scottish East Coast (Fig. 1). The field is operated by Amerada Hess Limited and came onstream in September 1993. Average production for 1995 was 184,000 BOPD oil exported via the Forties Pipeline System and 97 mmscfd gas exported via the SAGE (Scottish Area Gas Evaluation) pipeline system. Maximum daily oil and gas production has exceeded 220,000 BOPD and 120 mmscfd respectively. Over 165 million barrels of crude and 81 billion scf of gas have now been exported from Scott since start-up. The field produces from an Upper Jurassic sandstone reservoir that comprises several fault blocks and heterolithic layers. A wide range of reservoir fluid compositions are present and a number of the 20 production wells in the field produce H2S levels exceeding 150 ppm vol. in the separator gas phase. H2S is a naturally occurring gas found within oil and gas reservoirs. The gas is highly toxic, flammable and corrosive to certain materials. Produced gas containing high levels of H2S requires chemical treatment to remove or convert the gas to meet export pipeline specifications. This paper reviews the background, laboratory and field testing of liquid chemical H2S removal methods on the Scott platform. System Description Scott Process System. The Development currently includes 9 subsea oil production wells, 11 platform oil producers and 17 subsea injection wells. The Scott Field platform facilities comprise two separate jacket structures in around 140 metre water depth linked by two bridges. The UQ jacket supports the accommodation and utilities modules including the water injection pumps and risers, control room and helideck; the DP jacket supports the drilling rig module, separation and gas compression facilities, wellheads, and subsea production well and export pipeline risers (Fig. 2). Hydrocarbons from the production wells are processed through a single-train, three-stage oil, gas and water separation system. A dual train gas compression system separates and recycles NGLs from the produced gas, dries the gas by glycol dehydration and exports gas to the SAGE system (Fig. 3). ZnO H2S Removal System. The early start-up of Scott gas export in October 1993 required a temporary tight specification for the H2S content. The export gas was therefore routed through a single ZnO filled vessel located downstream of the high pressure gas compressor. The H2S reacts with ZnO to form zinc sulphide (ZnS) and water. The ZnS remains as a solid within the vessel while the water is removed as a vapour along with the gas. A by-pass around the vessel can be adjusted to obtain the required overall specification. P. 613

Eye contact, as an encounter between two conscious and self-conscious human beings, and in advance of any word being spoken, appears to have the remarkable capacity to accurately (Gladwell, 2005) form the feelings and the meaning-content that structures our interpretation of Others as more or less perfect or different versions of ourselves (e.g. “People find out I’m an actress and I see that ‘whore’ look flicker across their eyes” [Rachel Weisz]).With a primary focus on ‘the novel’ “as an intense experience of prolonged intimacy with another consciousness” (Lodge, 2002), this paper will seek to analyse and discuss the underpinning concepts and philosophical ideas, together with any prevailing psychological assumptions that relate to the content of The Gaze Encounter. More precisely, what occurs in that moment between the “before we are and what we were” (Lowell, 1992); in that moment when all kinds of assumptions and inferences, as well as judgements and decisions are made, usually by both characters, about the Other's ‘inner truth’, sanity, or essential being?This paper seeks to excavate those base and mainly unconscious physical sensations that form the basis of more or less conscious feelings that, then, generate decisions about The Other; frequently, before a word is spoken.The Heuristic research methodology (Moustakas, 1990) will be employed throughout. The results will establish a more robust relationship between sensations/feelings/decision-making.The Conclusions will either support of undermine Rogers’ (1957) concept of ‘unconditional positive regard’. DRW

Because of their invasive properties, Salmonella species are uniquely suited for use as live oral vaccines, and mutants attenuated in general metabolic functions show promise as vaccine strains. We have identified a Salmonella choleraesuis transposon mutant which is deficient in abilities to attach to, invade or penetrate through animal cells. This mutant is avirulent in mice, yet is able to persist within the liver, spleen and gut-associated lymphoid tissue for periods which may be adequate for induction of secretory, humoral and cell-mediated immunity. This and other strains attenuated in factors specifically required for Salmonella pathogenesis may have potential as vaccine strains.

The response of sweet corn canopy development to timing and severity of water deficit was determined in an experiment using a mobile rainshelter. Six irrigation treatments were applied such that plots experienced: (1) no water deficit; (2) full water deficit; (3) moderate pre-silking deficit; (4) severe pre-silking deficit; (5) moderate post-silking deficit; or (6) severe post-silking deficit. Soil moisture content profiles were measured using neutron moisture probes and water deficit was quantified using the concept of ‘potential soil moisture deficit’ (Dp), which was calculated from climatic data. Water deficit reduced leaf area, and the effect varied depending on its timing and severity. Early water deficit reduced the rate of leaf expansion (but not duration of expansion) and, consequently, the maximum area of individual leaves; it therefore reduced the maximum leaf area index (LAI). Moderate post-silking water deficit did not significantly reduce maximum LAI, but it hastened leaf senescence. Severe water deficit late in crop growth reduced canopy development by decreasing maximum LAI and advancing leaf senescence. A model was developed which accounted for these effects. Two measures of Dp were defined which related to both short-term transient responses and those integrated over longer times. The model made it possible to simply and mechanistically describe the effects of water deficit on canopy development.

The responses of sweet corn biomass and yield to timing and severity of water deficit were determined in an experiment using a mobile rainshelter. Six irrigation treatments were applied such that plots experienced: (1) no water deficit; (2) full water deficit; (3) moderate pre-silking deficit; (4) severe pre-silking deficit; (5) moderate post-silking deficit; or (6) severe post-silking deficit. Drought was quantified using the concept of potential soil moisture deficit, which was calculated from climatic data. Potential soil moisture deficit can be related simply to a wide range of plant performance variables, making it possible to compare the relative importance of variables in determining the overall response of the crop to drought. For all treatments, yield was related strongly to biomass, especially that accumulated after silking. Biomass, in turn, was reduced by water deficit, mainly because of reduced radiation use efficiency, but also because of reduced total radiation interception, particularly in early deficit treatments. Both water use efficiency and transpiration efficiency increased with water deficit, even though soil evaporation as a proportion of total water use also increased with deficit. There was no stage of crop development at which yield was particularly sensitive to water deficit, although yield components changed with timing of deficit. Importantly, measures of potential soil moisture deficit integrated the effects of timing and severity of drought, making it possible to simply and mechanistically account for the effects of water deficit on biomass and particularly yield.

Chinese technical education was severely curtailed during the cultural revolution, when senior professors often experienced great difficulties. However, ten years after the open-door policy was initiated, radical changes to computing and engineering curricula had been completed. The new computing curricula are modelled on ACM/IEEE recommendations, albeit set in a Chinese cultural environment and in general Tsinghua is supported by modern US technology. The author describes the department structure, undergraduate curricula and research initiatives at the university.

The thermodynamic and economic performance of a heat pump combined with a water heat store has been examined. The thermal store contains electrical resistance heaters which can boost the water temperature to 95°C. By utilising the off-peak tariffs for electricity it has been shown that the heat pump/heat store can compete economically with conventional central heating systems, based on an oil-fired boiler, a coal-fired boiler, or night storage heaters. To stand comparison with gas central heating, however, the cost of gas would have to increase by 6%, the capital cost of the heat pump/heat store be reduced by 20%, or the seasonal performance of the heat pump/heat store be improved by 17%.