J. J. O'Sullivan

In-hospital prognosis of patients with fasting hyperglycemia after first myocardial infarction.

Objective To investigate the incidence and prognostic significance of fasting hyperglycemia in a large group of patients with a first myocardial infarction. Research Design and Methods Blood glucose was measured after an 8-h overnight fast in 752 patients with a first myocardial infarction. Three groups of patients were identified: patients with normal fasting blood glucose (92.5%), patients with fasting hyperglycemia but no prior history of glucose intolerance (3%), and patients previously known to have diabetes mellitus (4.5%). Results The fasting hyperglycemic patients were significantly older and had significantly more in-hospital complications than the normal blood glucose group. Previously known diabetic subjects tended to be older and had more mechanical complications postinfarction than the group with normal blood glucose but the difference did not reach statistical significance. There was no significant difference between the diabetic subjects and patients with fasting hyperglycemia in mean age and in-hospital prognosis. Conclusions Fasting hyperglycemia detected after a first myocardial infarction is associated with a poor in-hospital prognosis that was not due to larger infarct size, as reflected in peak levels of cardiac enzymes. The measurement of a fasting blood glucose level provides additional information in identifying high-risk groups of patients postinfarction.

Flow resistance of emergent vegetation

Abstract Conventional resistance equations (such as those of Manning, Chezy and Darcy–Weisbach) are inappropriate for flow through emergent vegetation, where resistance is exerted primarily by stem drag throughout the flow depth rather than by shear stress at the bed. An alternative equation form is suggested, in which the resistance coefficient is related to measurable vegetation characteristics and can incorporate bed roughness when this is significant. Equation performance is confirmed by comparison of predicted and measured stage–discharge relationships for flow through artificial cylindrical stems, and by comparison of calibrated and measured drag coefficient values for natural vegetation.

Silent ischaemia in diabetic men with autonomic neuropathy.

Autonomic neuropathy is associated with an increased incidence of silent myocardial infarction and sudden death. The purpose of this study was to investigate the prevalence of silent myocardial ischaemia in diabetic patients with autonomic neuropathy and without. Five standard autonomic function tests were performed on 41 men with diabetes: postural change in blood pressure, postural change in heart rate, heart rate response to deep breathing, heart rate response to Valsalvas manoeuvre, and blood pressure response to sustained handgrip. There were 17 patients with autonomic neuropathy (group A) and 24 with normal autonomic function (group B). All patients underwent 24 hour ambulatory electrocardiographic monitoring to detect silent ischaemia. There was no significant difference in risk factors for coronary artery disease or history of angina pectoris between these groups. The prevalence of silent ischaemia was 64.7% in group A (95% confidence interval (95% CI) 38.33 to 85.79%) and 4.1% in group B (95% CI 0.11 to 21.12%). This represents a relative risk of 42.2 (95% CI 4.5 to 39.4, p less than 0.001). These results are consistent with the concept that autonomic neuropathy may prevent the development of anginal pain and thus obscure the presence of ischaemic heart disease. Twenty four hour ambulatory electrocardiographic monitoring may identify a subgroup of diabetic patients with autonomic neuropathy who have myocardial ischaemia and to whom treatment may be offered.

A decision support tool for sustainable planning of urban water systems: Presenting the Dynamic Urban Water Simulation Model

Population growth, urbanisation and climate change represent significant pressures on urban water resources, requiring water managers to consider a wider array of management options that account for economic, social and environmental factors. The Dynamic Urban Water Simulation Model (DUWSiM) developed in this study links urban water balance concepts with the land use dynamics model MOLAND and the climate model LARS-WG, providing a platform for long term planning of urban water supply and water demand by analysing the effects of urbanisation scenarios and climatic changes on the urban water cycle. Based on potential urbanisation scenarios and their effects on a citys water cycle, DUWSiM provides the functionality for assessing the feasibility of centralised and decentralised water supply and water demand management options based on forecasted water demand, stormwater and wastewater generation, whole life cost and energy and potential for water recycling. DUWSiM has been tested using data from Dublin, the capital of Ireland, and it has been shown that the model is able to satisfactorily predict water demand and stormwater runoff.

Cardiac catheterisation with 5 French catheters.

From the beginning of November 1987 to the end of January 1989, 526 coronary arteriograms and left ventricular angiograms were performed with 5 French coronary catheters. In 448 (85%) patients diagnostic pictures were obtained with three standard types of 5 French catheters (No 4 Judkins): that is, left coronary, right coronary, and pigtail catheters. In 60 patients (11.4%) various other 5 French catheters were required to complete the study. In nine patients (1.7%), a 7 or 8 French catheter was used. Major complications causing cardiac arrest or requiring urgent operation developed in five patients. Sixty two patients (11.77%) had minor complications that required sublingual nitrates or a single bolus of atropine, or developed a haematoma that did not need intervention or had a mild reaction to the contrast material. Complications of moderate severity developed in 17 patients (3.2%): severe chest pain, arrhythmia requiring a temporary pacemaker, contrast reaction associated with hypotension, haematoma requiring blood transfusion, or a transient ischaemic episode. There were no deaths. 5 French catheters were used for routine coronary angiography and left ventriculography in 98.3% of patients. There were no major complications related to femoral artery puncture. The routine use of 5 French coronary catheters should increase the feasibility of safe coronary angiography in outpatients and should reduce the cost of this investigation.

The impact of cattle access on ecological water quality in streams: Examples from agricultural catchments within Ireland

Unrestricted cattle access to rivers and streams represent a potentially significant localised pressure on freshwater systems. However there is no consensus in the literature on the occurrence and extent of impact and limited research has examined the effects on aquatic biota in the humid temperate environment examined in the present study. Furthermore, this is one of the first times that research consider the potential for cattle access impacts in streams of varying water quality in Northern Europe. We investigated the effects of cattle access on macroinvertebrate communities and deposited fine sediment levels, in four rivers of high/good and four rivers of moderate water quality status which drain, low gradient, calcareous grassland catchments in Ireland. We assessed the temporal variability in macroinvertebrates communities across two seasons, spring and autumn. Site specific impacts were evident which appeared to be influenced by water quality status and season. All four high/good water status rivers revealed significant downstream changes in community structure and at least two univariate metrics (total richness and EPT richness together with taxon, E and EPT abundance). Two of the four moderate water status rivers showed significant changes in community structure, abundance and richness metrics and functional feeding groups driven in the main by downstream increases in collectors/gatherers, shredders and burrowing taxa. These two moderate water status rivers had high or prolonged livestock activity. In view of these findings, the potential for some of these sites to achieve at least high/good water quality status, as set out in the EU Water Framework Directive, may be compromised. The results presented highlight the need for additional research to further define the site specific factors and livestock management practices, under different discharge conditions, that increase the risk of impact on aquatic ecology due to these cattle-river interactions.

Evaluating the relationship between biotic and sediment metrics using mesocosms and field studies.

An ongoing research challenge is the detection of biological responses to elevated sediment and the identification of sediment-specific bioassessment metrics to evaluate these biological responses. Laboratory mesocosms and field observations in rivers in Ireland were used to evaluate the relationship between a range of biological and sediment metrics and to assess which biological metrics were best at discerning the effects of excess sediment on macroinvertebrates. Results from the mesocosm study indicated a marked decrease in the abundance of sensitive taxa with increasing sediment surface cover. % EPT (Ephemeroptera, Plecoptera, Trichoptera) and % E abundances exhibited the strongest negative correlation with sediment surface cover in the mesocosm study. The field study revealed that % EPT abundance was most closely correlated with % sediment surface cover, explaining 13% of the variance in the biological metric. Both studies revealed weaker relationships with a number of other taxonomy-based metrics including total taxon abundance, total taxon richness and moderate relationships with the Proportion of Sediment-sensitive Invertebrates metric (PSI). All trait-based metrics were poorly correlated with sediment surface cover in the field study. In terms of sediment metrics, % surface cover was more closely related to biological metrics than either re-suspendable sediment or turbidity. These results indicate that % sediment surface cover and % EPT abundance may be useful metrics for assessing the effect of excessive sediment on macroinvertebrates. However, EPT metrics may not be specific to sediment impact and therefore when applied to rivers with multiple pressures should be combined with observations on sediment cover.

Sediment discharge prediction in meandering compound channels

Three sediment transport formulae have been applied to experimental data for sediment transport during inbank and overbank flow in meandering compound channels. The experimental tests were undertaken in the large-scale UK Flood Channel Facility and the small-scale Ulster Channel. The relative depth and channel sinuosity were taken as criteria to establish where sediment transport takes place. An attempt to find a calculation method capable of accurately predicting the mean velocity in the main channel and the total channel cross-sections has been made. Comparison between computed and measured sediment discharges indicates that theYang sediment transport formula applied with the proposed velocity calculation method gives the best predictions for sediment discharge

Simulating the effects of climate change, economic and urban planning scenarios on urban runoff patterns of a metropolitan region

Urban development and climate change are expected to have significant effects on urban stormwater runoff. In this study, the Dynamic Urban Water Simulation Model (DUWSiM) is applied to Dublin, Ireland, to explore urban runoff patterns under varying urban growth and climate scenarios. Results show that annual urban runoff could decrease by 3.0% from climate change and monthly runoff could increase by 30% in winter and decrease by 28% in summer. Results also indicate that urban growth could increase annual runoff by up to 15%. The combined effect of climatic and land-use change generated runoff may potentially increase annual totals from between 2.9% to 21%. Monthly changes in runoff totals could increase by up to 57%. Accommodating these variations in runoff between the scenarios, flexible decentralised systems such as green roofs and pervious pavements, have a vital role in increasing the adaptability and long term sustainability of water infrastructure.

An agent-based wireless sensor network for water quality data collection

Future generation intelligent systems will harvest embedded intelligence as a means of delivering new and innovative services in diverse domains. Amongst the most challenging scenarios are those that consist of Wireless Sensor Networks (WSNs) as their functional operating constraints are significant. This paper proposes the use of in-network data aggregation techniques to enable the efficient acquisition of data in a water quality forecasting WSN application. Such an approach reduces the energy required for data transmission by collecting statistics from the network rather than analyzing the raw data centrally. Specifically, clustering points, where aggregation occurs, are modelled as mobile intelligent agents.