A surrogate model for simulation–optimization of aquifer systems subjected to seawater intrusion

This study presents the application of Evolutionary Polynomial Regression (EPR) as a pattern recognition system to predicate the behavior of nonlinear and computationally complex aquifer systems subjected to seawater intrusion (SWI). The developed EPR models are integrated with a multi objective genetic algorithm to examine the efficiency of different arrangements of hydraulic barriers in controlling SWI. The objective of the optimization is to minimize the economic and environmental costs. The developed EPR model is trained and tested for different control scenarios, on sets of data including different pumping patterns as inputs and the corresponding set of numerically calculated outputs. The results are compared with those obtained by direct linking of the numerical simulation model with the optimization tool. The results of the two above-mentioned simulation–optimization (S/O) strategies are in excellent agreement. Three management scenarios are considered involving simultaneous use of abstraction and recharge to control SWI. Minimization of cost of the management process and the salinity levels in the aquifer are the two objective functions used for evaluating the efficiency of each management scenario. By considering the effects of the unsaturated zone, a subsurface pond is used to collect the water and artificially recharge the aquifer. The distinguished feature of EPR emerges in its application as the metamodel in the S/O process where it significantly reduces the overall computational complexity and time. The results also suggest that the application of other sources of water such as treated waste water (TWW) and/or storm water, coupled with continuous abstraction of brackish water and its desalination and use is the most cost effective method to control SWI. A sensitivity analysis is conducted to investigate the effects of different external sources of recharge water and different recovery ratios of desalination plant on the optimal results

Miscellaneous Rheumatic Diseases [73-83]: 73. Is There a Delay in Specialist Referral of Hot Swollen Joint?

Background: Patients with acute, hot, swollen joints commonly present to general practitioners, emergency departments and/or acute admitting teams rather than directly to rheumatology. It is imperative to consider septic arthritis in the differential diagnosis of these patients. The British Society of Rheumatology (BSR) has produced guidelines for the management of this condition, which include recommendations for early specialist referral and joint aspiration of all patients with suspected septic arthritis. We examined whether the initial management of patients with acute hot swollen joint(s) at University College London Hospital (UCLH) follows BSR guidelines. Methods: For the period Feb to Nov 2009, appropriate patients were identified by searching the UCLH database using the diagnostic terms, "pyogenic arthritis”, "septic arthritis” and "gout”; and from all joint aspirate requests sent to microbiology. Medical notes were obtained and any patients who had elective arthroscopies or chronic (> 6 weeks) symptoms were excluded. Data were collected on the time taken from the onset of symptoms to specialist (orthopaedic/rheumatology) referral and joint aspiration, collection of blood cultures and antibiotic treatment with or without microbiology advice. Results: Twenty patients were identified with hot swollen (18 monoarticular, 3 prosthetic) joint(s) of < 2 weeks duration. Of whom, 3/20 (15%) were admitted directly to rheumatology, 7/20 (35%) to the acute admissions unit, 3/20 (15%) to orthopaedic, 4/20 (20%) to a medical team and 1/20 (5%) to general surgery. In 19 (95%) cases, specialist (rheumatology/orthopaedic) advice was sought. Of 14 cases not seen directly by specialists 9 (64%) were referred at 24-48 h and 5 (36%) at 48-192 h. All 20 patients had joint aspiration. In 9/20 (45%) of cases, joint aspiration was performed in less than 6 h, 3/20 (15%) cases at 6-24h and 6/20 (30%) cases at 24-192 h and was not recorded in two patients. Of these, crystals were identified in two and one was culture positive. Blood cultures were received for only 6/20 (30%) of cases and only clearly documented to have been taken prior to antibiotic therapy and none were positive. Of 14/20 (70%) started on antibiotic treatment empirically, only 6 (42%) were preceded by joint aspiration. In the 6 patients not treated with antibiotics due to low index of suspicion of septic arthritis, synovial fluid and blood cultures were negative. Microbiology advice was sought in 10/20 (50%) of cases by the admitting teams but the timing of this advice is unclear. Conclusions: Despite the provision of 24 h rheumatology and orthopaedic cover at UCLH, we found a significant delay in acute medical firms seeking specialist advice on the management of patients with acute, hot swollen joints with subsequent deviation from BSR guidelines. Consequently, we plan to increase awareness of these guidelines amongst medical firms at UCLH. Disclosure statement: All authors have declared no conflicts of interes

Response of slow-growing chickens to feed restriction and effects on growth performance, blood constituents and immune markers

An experiment was conducted to study the response of a slow growing chickens breed “Sinai” to feed restriction (FR) and the effects on growth performance, blood constituents and immune markers using a total number of 60 unsexed 7-d-old chicks. Chickens were housed in battery brooders during d 1 to 35 of age and randomly distributed keeping similar initial body weight, in two FR treatment groups. During 0-6 d of age, chickens were fed ad libitum, a mash commercial diet. During d 7-14 of age, chickens were fed either 100 or 80 % of the daily amount of feed consumed by the control group during the previous day. From d 15 to d 35, chickens were fed ad libitum diets a mash commercial diet. At the end of the experiment, body weight gain on the FR regimen was significantly lower than that of the control group, but feed intake and feed conversion ratio (FCR) were not affected. In addition, red blood cells parameters and white blood cells traits were not negatively affected. However, hemagglutination inhibition titter for New castle disease virus, monocyte and total cholesterol were significantly decreased by FR regimen, but blood plasma albumin and immunoglobulin A significantly increased. In conclusion, slow growing chickens could tolerate 27.2 % FR during the 2nd week of age without significant differences in feed intake and FCR for the whole period, and general health status and metabolic profiles indicating a compensatory growth during 15-35 d of age although growth was in favour to the unrestricted group.

Management of Seawater Intrusion in Coastal Aquifers: A Review

Seawater intrusion (SWI) is one of the most challenging and widespread environmental problems that threaten the quality and sustainability of fresh groundwater resources in coastal aquifers. The excessive pumping of groundwater, associated with the lack of natural recharge, has exacerbated the SWI problem in arid and semi-arid regions. Therefore, appropriate management strategies should be implemented in coastal aquifers to control the impacts of SWI problems, considering acceptable limits of economic and environmental costs. The management of coastal aquifers involves the identification of an acceptable ultimate landward extent of the saline water body and the calculation of the amount of seaward discharge of freshwater that is necessary to keep the saline&ndash;freshwater interface in a seacoast position. This paper presents a comprehensive review of available hydraulic and physical management strategies that can be used to reduce and control SWI in coastal aquifers. Advantages and disadvantages of the different approaches are presented and discussed

RIvaroxaban and VAscular Surgery (RIVAS): insights from a multicenter, worldwide web-based survey

no abstract availabl