Impact of water management practice scenarios on wastewater flow and contaminant concentration.

Due to frequent droughts and rapid population growth in urban areas, the adoption of practices to reduce the usage of fresh water is on the rise. Reduction in usage of fresh water can be achieved through various local water management practices (WMP) such as Water Demand Management (WDM) and use of alternative water sources such as Greywater Recycling (GR) and Rainwater Harvesting (RH). While the positive effects of WMPs have been widely acknowledged, the implementation of WMPs is also likely to lower the wastewater flow and increase the concentration of contaminants in sewage. These in turn can lead to increases in sewer problems such as odour and corrosion. This paper analyses impacts of various WMP scenarios on wastewater flow and contaminant load. The Urban Volume and Quality (UVQ) model was used to simulate wastewater flow and the associated wastewater contaminants from different WMP scenarios. The wastewater parameters investigated were those which influence odour and corrosion problems in sewerage networks due to the formation of hydrogen sulphide. These parameters are: chemical oxygen demand (COD), nitrate (NO3(-)), sulphate (SO4(2-)), sulphide (S(2-)) and iron (Fe) that were contributed by the households (not including the biochemical process in sewer pipe). The results will help to quantify the impact of WMP scenarios on odour and corrosion in sewerage pipe networks. Results show that the implementation of a combination of WDM and GR had highly increased the concentration of all selected contaminant that triggered the formation of hydrogen sulphide, namely COD, sulphate and sulphide. On the other hand, the RH scenario had the least increase in the concentration of the contaminants, except iron concentrations. The increase in iron concentrations is actually beneficial because it inhibits the formation of hydrogen sulphide.

Impact of water source management practices in residential areas on sewer networks - a review.

Prolonged drought which has occurred everywhere around the world has caused water shortages, leading many countries to consider more sustainable practices, which are called source management practices (SMPs) to ensure water availability for the future. SMPs include the practices of water use reduction, potable water substitution and wastewater volume reduction such as water demand management, rainwater harvesting, greywater recycling and sewer mining. Besides the well known advantages from SMPs, they also contribute to the alteration of wastewater characteristics which finally affect the process in downstream infrastructure such as sewerage networks. Several studies have shown that the implementation of SMPs decreases the wastewater flow, whilst increasing its strength. High-strength wastewater can cause sewer problems such as sewer blockage, odour and corrosion. Yet, not all SMPs and their impact on existing sewer networks have been investigated. Therefore, this study reviews some examples of four common SMPs, the wastewater characteristics and the physical and biochemical transformation processes in sewers and the problems that might caused by them, and finally the potential impacts of those SMPs on wastewater characteristics and sewer networks are discussed. This paper provides sewer system managers with an overview of potential impacts on the sewer network due to the implementation of some SMPs. Potential research opportunities for the impact of SMPs on existing sewers are also identified.

Seasonal factors influencing the failure of buried water reticulation pipes.

While the use of environmental factors in the analysis and prediction of failures of buried reticulation pipes in cold environments has been the focus of extensive work, the same cannot be said for failures occurring on pipes in other (non-freezing) environments. A novel analysis of pipe failures in such an environment is the subject of this paper. An exploratory statistical analysis was undertaken, identifying a peak in failure rates during mid to late summer. This peak was found to correspond to a peak in the rate of circumferential failures, whilst the rate of longitudinal failures remained constant. Investigation into the effect of climate on failure rates revealed that the peak in failure rates occurs due to differential soil movement as the result of shrinkage in expansive soils.

Calcium/NFAT signalling promotes early nephrogenesis.

A number of Wnt genes are expressed during, and are known to be essential for, early kidney development. It is typically assumed that their products will act through the canonical ß-catenin signalling pathway. We have found evidence that suggests canonical Wnt signalling is not active in the early nephrogenic metanephric mesenchyme, but instead provide expressional and functional evidence that implicates the non-canonical Calcium/NFAT Wnt signalling pathway in nephrogenesis. Members of the NFAT (Nuclear Factor Activated in T cells) transcription factor gene family are expressed throughout murine kidney morphogenesis and NFATc3 is localised to the developing nephrons. Treatment of kidney rudiments with Cyclosporin A (CSA), an inhibitor of Calcium/NFAT signalling, decreases nephron formation--a phenotype similar to that in Wnt4(-/-) embryos. Treatment of Wnt4(-/-) kidneys with Ionomycin, an activator of the pathway, partially rescues the phenotype. We propose that the non-canonical Calcium/NFAT Wnt signalling pathway plays an important role in early mammalian renal development and is required for complete MET during nephrogenesis, potentially acting downstream of Wnt4.

A pathway to a more sustainable water sector: sustainability-based asset management.

The water sectors of many countries are faced with the need to address simultaneously two overarching challenges; the need to undertake effective asset management coupled with the broader need to evolve business processes so as to embrace sustainability principles. Research has thus been undertaken into the role sustainability principles play in asset management. As part of this research, a series of 25 in-depth interviews were undertaken with water sector professionals from around Australia. Drawing on the results of these interviews, this paper outlines the conceptual relationship between asset management and sustainability along with a synthesis of the relevant opinions voiced in the interviews. The interviews indicated that the participating water authorities have made a strong commitment to sustainability, but there is a need to facilitate change processes to embed sustainability principles into business as usual practices. Interviewees also noted that asset management and sustainability are interlinked from a number of perspectives, especially in the way decision making is undertaken with respect to assets and service provision. The interviews also provided insights into the research needed to develop a holistic sustainability-based asset management framework.

Neurosurgical trainees operative experience before and after introduction of the New Deal for junior doctors.

To compare operative experience before and after implementation of the New Deal to reduce junior doctors working hours, operative data was audited over a 6-month period. The three registrars with national training numbers in our unit were placed on two virtual working patterns to determine what their operative experience would have been over that 6-month period. Comparison with a 1980s trainee over a similar period was also made. Trainees on a 1:3 rota would have performed more emergency operations [32 (28 - 38)], than those on a partial shift [1:6 with following day off, 16 (13 - 23)]. Particular examples include trauma craniotomies 13 (9 - 15) versus 6 (3 - 11) and CSF diversion, 9 (2 - 13) versus 4 (2 - 7). Although trainees on a 1:3 on call rota would have had more emergency operative experience over the same period of time, less common procedures, such as lumber decompression for cauda equina syndrome, were equally distributed between both groups. Trainees doing the partial shift would have lost 18 (12 - 24) elective cases over the same period as a result of enforced absence following periods of duty. These included posterior fossa, complex spinal, benign and rare cranial procedures. The increasingly common option of employing juniors on a full shift rota would have an even greater impact on training. Trainees are unavailable for elective training on night shift and then for a compensatory period afterwards, doubling the time spent away from formal surgical training. Indiscriminate reduction in working hours by enforced absence for compensatory rest has a potentially deleterious impact on elective training. By reducing the out of hours commitment trainees have a reduced, but possibly acceptable, exposure to emergency neurosurgery without impact on elective training.

Sustainable management of leakage from wastewater pipelines.

Wastewater pipeline leakage is an emerging concern in Europe, especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritize proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions, and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilizes these models to predict the condition of pipes in individual zones, and to optimize the utilization of rehabilitation resources by targeting the areas with the highest leakage rates.

New proposals for training in neurosurgery.

The rapidly evolving changes in working patterns, career structure and the regulation of training of doctors have provided an ideal opportunity for proposals to improve the programme for the training of neurosurgeons. The Education and Training Committee of the Society of British Neurological Surgeons (D.G. Hardy, A. J. W. Steers, N. T. Gurusinghe, P. M. Foy, P. van Hille, R. A. Cowie, H. A. Crockard, O. Sparrow and S. Burn) has, in recent months, worked closely with the Specialist Advisory Committee (SAC) in neurosurgery, Department of Health (Modernizing Medical Careers Group, H. A. Crockard, A. Havers, T. Hobbs) and colleagues from the major neuroscience specialties to develop a new programme based on a 'Common Stem' approach. This article describes the principles of the programme. The proposals have received approval by the Council of the SBNS, the Presidents of the four Surgical Royal Colleges and the Senate of Surgery.

Heterosexuals' use of "fag" and "queer" to deride one another: a contributor to heterosexism and stigma.

This paper is on heterosexuals' use of words such as "fag" and "queer" to refer to one another in an insulting manner. This behavior perpetuates heterosexism and the stigmatization of gays. Two hundred and fifty-seven university students (73% Euro-American) served as participants. Males exhibited more anti-gay prejudice and anti-gay behavior than females. Heterosexual males frequently used words such as "fag" and "queer" to put one another down. Anti-homosexual prejudice was predictive of anti-gay behavior. However, approximately half of those who engaged in the behavior were not strongly anti-homosexual. For these individuals, the behavior may win approval from their social group. Awareness campaigns and peer reminders that the derisive use of "fag" and "queer" harms homosexuals may be effective in changing this group. It is more difficult to reduce this behavior in individuals with strong anti-homosexual attitudes. The role of individuals and educational and work organizations in bringing about change is discussed.

The hibernating heart: reversible left ventricular dysfunction in chronic heart failure.

A patient with severe heart failure secondary to coronary heart disease is presented. Following investigation he was thought to have significant areas of myocardial hibernation and was therefore treated with coronary revascularisation, with major clinical benefit.

Cardiac syncope due to transient coronary artery occlusion: the role of percutaneous angioplasty.

A case of cardiac syncope is presented, associated with single vessel coronary disease. The mechanism of the syncope would appear to be a ventricular arrhythmia with transmural myocardial ischaemia due to transient occlusion of the diseased coronary artery. The symptoms and electrocardiographic abnormalities were reproduced and subsequently abolished by percutaneous coronary angioplasty.

Stress echocardiography.

Stress echocardiography has now emerged from the days of research and clinical evaluation to take its place alongside other non-invasive imaging methods in coronary artery disease. It is safe, versatile, and clinically accurate. It has been validated against radionuclide perfusion imaging; the cost and convenience advantages for echocardiography must be balanced against the greater automaticity and probable sensitivity (in single-vessel disease) of perfusion imaging. There is a definite 'learning curve' for stress echo--both in the practice of image acquisition and in interpretation. The choice between these two techniques will often be determined by local availability and demand. However, the addition of a stress echo service to a modern ECG department is likely to be considerably cheaper than the cost of a new gamma camera and radio-pharmacy service. A recent editorial called for a 'critical reappraisal' of stress echo and its application in the UK. The increasing availability of the necessary hardware and software for the newer echocardiography machines is likely to accelerate this process in the near future. A more recent application for the technique is in the determination of contractile reserve and 'viability' in patients with poor LV function and IHD, using low-dose dobutamine regimens. Stress echocardiography is therefore likely to occupy an expanding role in the management of patients with coronary artery disease, as an adjunct to the exercise ECG.

Myocardial hibernation.

Myocardial hibernation is a potentially reversible cause of resting left ventricular dysfunction in some patients with coronary artery disease. Successful revascularisation in these patients can lead to improved ventricular function and hence improved prognosis. This review discusses the pathophysiology of myocardial hibernation and the methods that are currently available to detect it.

Non-Hodgkins lymphoma presenting with evidence of right ventricular outflow tract obstruction.

Anterior mediastinal tumours have been reported that initially presented with signs suggestive of cardiac disease. The widespread availability of two-dimensional echocardiography has demonstrated that, in the majority of cases, right ventricular compression is the major cardiac complication of such masses. We report two cases of mediastinal lymphoma that presented with chest pain and signs of right ventricular outflow obstruction.