Best Values (best + value)

Distribution by Scientific Domains

Selected Abstracts

Performance Management, Evaluation and Learning in ,Modern' Local Government

Ian Sanderson
Public sector reforms throughout OECD member states are producing a new model of ,public governance' embodying a more modest role for the state and a strong emphasis on performance management. In the UK, the development of performance management in the context of the ,new public management' has been primarily ,top-down' with a dominant concern for enhancing control and ,upwards account-ability' rather than promoting learning and improvement. The development of performance management and evaluation in local government in the UK has been conditioned by external pressures, especially reforms imposed by central government, which have encouraged an ,instrumental,managerial' focus on performance measurement. The new Labour government's programme of ,modernizing local government' places considerable emphasis on performance review and evaluation as a driver of continuous improvement in promoting Best Value. However, recent research has indicated that the capacity for evaluation in local government is uneven and many obstacles to evaluation exist in organizational cultures. Local authorities need to go beyond the development of review systems and processes to ensure that the capacity for evaluation and learning is embedded as an attribute of ,culture' in order to achieve the purpose of Best Value. [source]

Pilot study: The effect of reducing treatment on exercise induced bronchoconstriction,

E.T.G. Kersten MD
Abstract Rationale Asthma therapy should be stepped up or stepped down in response to changes in asthma control. However, there is little evidence available on the optimal timing, sequence, and degree of medication reductions. In this study we analyzed clinically stable asthmatic children who underwent a medication reduction from a combination preparation consisting of an inhaled corticosteroid (ICS) and long acting beta2-agonist (LABA) to monotherapy with the same dose of the ICS. We hypothesized that the extent of exercise-induced bronchoconstriction (EIB) would not increase after the cessation of the LABA. Methods Nineteen children, aged 8,16 years, with clinically stable asthma, receiving LABA/ICS combination therapy, were analyzed in this open-label pilot study. Children performed an exercise challenge at baseline and 3 weeks after the medication reduction. Best values of spirometric measurements of the forced expiratory volume in 1,sec (FEV1) were used for statistical calculations. Results Maximum percent fall in FEV1 was significantly lower after 3 weeks of ICS monotherapy (P,=,0.03). Eight of 19 children had a ,15% fall in FEV1 after exercise at the initial exercise challenge. In this subgroup, maximum percent fall in FEV1 after the medication reduction was significantly lower (P,<,0.01), and in six children it decreased to <15%, indicating they no longer had EIB. Conclusion In clinically stable asthmatic children on LABA/ICS combination therapy, the cessation of the LABA can reduce and in most cases abolish EIB. Pediatr. Pulmonol. 2010; 45:927,933. 2010 Wiley-Liss, Inc. [source]

Catalyst-Free Efficient Growth, Orientation and Biosensing Properties of Multilayer Graphene Nanoflake Films with Sharp Edge Planes,

Nai Gui Shang
Abstract We report a novel microwave plasma enhanced chemical vapor deposition strategy for the efficient synthesis of multilayer graphene nanoflake films (MGNFs) on Si substrates. The constituent graphene nanoflakes have a highly graphitized knife-edge structure with a 2,3,nm thick sharp edge and show a preferred vertical orientation with respect to the Si substrate as established by near-edge X-ray absorption fine structure spectroscopy. The growth rate is approximately 1.6,m min,1, which is 10 times faster than the previously reported best value. The MGNFs are shown to demonstrate fast electron-transfer (ET) kinetics for the Fe(CN)63,/4, redox system and excellent electrocatalytic activity for simultaneously determining dopamine (DA), ascorbic acid (AA) and uric acid (UA). Their biosensing DA performance in the presence of common interfering agents AA and UA is superior to other bare solid-state electrodes and is comparable only to that of edge plane pyrolytic graphite. Our work here, establishes that the abundance of graphitic edge planes/defects are essentially responsible for the fast ET kinetics, active electrocatalytic and biosensing properties. This novel edge-plane-based electrochemical platform with the high surface area and electrocatalytic activity offers great promise for creating a revolutionary new class of nanostructured electrodes for biosensing, biofuel cells and energy-conversion applications. [source]

Sensitivity analysis of neural network parameters to improve the performance of electricity price forecasting

Paras Mandal
Abstract This paper presents a sensitivity analysis of neural network (NN) parameters to improve the performance of electricity price forecasting. The presented work is an extended version of previous works done by authors to integrate NN and similar days (SD) method for predicting electricity prices. Focus here is on sensitivity analysis of NN parameters while keeping the parameters same for SD to forecast day-ahead electricity prices in the PJM market. Sensitivity analysis of NN parameters include back-propagation learning set (BP-set), learning rate (,), momentum (,) and NN learning days (dNN). The SD parameters, i.e. time framework of SD (d=45 days) and number of selected similar price days (N=5) are kept constant for all the simulated cases. Forecasting performance is carried out by choosing two different days from each season of the year 2006 and for which, the NN parameters for the base case are considered as BP-set=500, ,=0.8, ,=0.1 and dNN=45 days. Sensitivity analysis has been carried out by changing the value of BP-set (500, 1000, 1500); , (0.6, 0.8, 1.0, 1.2), , (0.1, 0.2, 0.3) and dNN (15, 30, 45 and 60 days). The most favorable value of BP-set is first found out from the sensitivity analysis followed by that of , and ,, and based on which the best value of dNN is determined. Sensitivity analysis results demonstrate that the best value of mean absolute percentage error (MAPE) is obtained when BP-set=500, ,=0.8, ,=0.1 and dNN=60 days for winter season. For spring, summer and autumn, these values are 500, 0.6, 0.1 and 45 days, respectively. MAPE, forecast mean square error and mean absolute error of reasonably small value are obtained for the PJM data, which has correlation coefficient of determination (R2) of 0.7758 between load and electricity price. Numerical results show that forecasts generated by developed NN model based on the most favorable case are accurate and efficient. Copyright 2008 John Wiley & Sons, Ltd. [source]

Evaluating the Cost-Effectiveness of Fall Prevention Programs that Reduce Fall-Related Hip Fractures in Older Adults

Kevin D. Frick PhD
OBJECTIVES: To model the incremental cost-utility of seven interventions reported as effective for preventing falls in older adults. DESIGN: Mathematical epidemiological model populated by data based on direct clinical experience and a critical review of the literature. SETTING: Model represents population level interventions. PARTICIPANTS: No human subjects were involved in the study. MEASUREMENS: The last Cochrane database review and meta-analyses of randomized controlled trials categorized effective fall-prevention interventions into seven groups: medical management (withdrawal) of psychotropics, group tai chi, vitamin D supplementation, muscle and balance exercises, home modifications, multifactorial individualized programs for all elderly people, and multifactorial individualized treatments for high-risk frail elderly people. Fall-related hip fracture incidence was obtained from the literature. Salary figures for health professionals were based on Bureau of Labor Statistics data. Using an integrated healthcare system perspective, healthcare costs were estimated based on practice and studies on falls in older adults. Base case incremental cost utility ratios were calculated, and probabilistic sensitivity analyses were conducted. RESULTS: Medical management of psychotropics and group tai chi were the least-costly, most-effective options, but they were also the least studied. Excluding these interventions, the least-expensive, most-effective options are vitamin D supplementation and home modifications. Vitamin D supplementation costs less than home modifications, but home modifications cost only $14,794/quality-adjusted life year (QALY) gained more than vitamin D. In probabilistic sensitivity analyses excluding management of psychotropics and tai chi, home modification is most likely to have the highest economic benefit when QALYs are valued at $50,000 or $100,000. CONCLUSION: Of single interventions studied, management of psychotropics and tai chi reduces costs the most. Of more-studied interventions, home modifications provide the best value. These results must be interpreted in the context of the multifactorial nature of falls. [source]

Production of hydrogen via glycerol steam reforming in a Pd-Ag membrane reactor over Co-Al2O3 catalyst

A. Iulianelli
Abstract Generally, biodiesel fuel, when converted from vegetables oils, produces around 10 wt% of glycerol as a byproduct, which could be used for producing hydrogen by a steam-reforming reaction. Different scientific works have been realized in conventional reactors on the steam reforming of glycerol (GSR) in the aqueous or the gas phase. High reaction pressure and a relatively small catalyst deactivation are noticed when GSR is carried out in an aqueous phase, whereas the catalyst deactivation is the main disadvantage in the gas phase. In this work, GSR reaction was performed in a perm-selective Pd-Ag membrane reactor (MR) packed with a Co-Al2O3 commercial catalyst in order to extract a CO-free hydrogen stream and also enhance the performances in terms of glycerol conversion and hydrogen yield with respect to a traditional reactor (TR), both working at weight hourly space velocity (WHSV) = 1.01 h,1, 400 C and H2O/C3H8O3 = 6/1. In MR, a maximum glycerol conversion of around 45.0% was achieved at 1.0 bar as reaction pressure, whereas it was around 94% at 4.0 bar. Moreover, as best value, more than 60.0% of CO-free hydrogen recovery was achieved in the MR at 4.0 bar and 22.8 of sweep factor (sweep gas to glycerol ratio). Copyright 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Supercritical CO2 Extraction of Essential Oil from Algerian Rosemary (Rosmarinus officinalis,L.)

A. Zermane
Abstract The present study presents experimental results concerning the supercritical CO2 extraction of essential oil from Algerian rosemary leaves. The effects of key operating parameters such as pressure, temperature, particle size and CO2 mass flow rate on the extraction yield were investigated. The obtained yields were in the range of 0.95,3.52,g oil/g dry rosemary, and the best value was observed at a pressure of 22,MPa, a temperature of 40,C, a flow rate of 7,g/min, and a particle size of 1,mm. The performance of the local rosemary used was assessed by comparison of the obtained yields with values reported in the literature for essential oils derived from different rosemary sources. The GC and the GC-MS analyses showed that the major compound detected in the essential oil was camphor, at 48.89,wt,%. [source]

New Coordination Modes of L -Ascorbic Acid and Dehydro- L -ascorbic Acid as Dianionic Chelating Ligand for Platinum

Paola Bergamini
Abstract A variety of coordination modes of L -ascorbic acid as an anionic bidentate ligand has been exploited to prepare platinum(II) complexes 1,7 that contain phosphanes or R,R -dach (1R,2R -diaminocyclohexane) as neutral ligands in which O2, O3, O5, O6 and C2 act as anionic donating functionalities. An alternative synthetic route to known O2,O3 complexes is proposed, and their solubility in water has been enhanced by introducing PTA (1,3,5-triaza-7-phosphaadamantane) as a neutral ligand. A new coordination mode of ascorbic acid (O2 and O3 protected) as an O5,O6-diolate chelating ligand has been characterised in solution by NMR spectroscopy and in the solid state by X-ray crystallography. The first example of a platinum complex that contains dehydroascorbic acid, 7, has also been prepared and its X-ray crystal structure has been determined. The antiproliferative activity in vitro of complexes 1,7 has been tested, and the best values were obtained for the DHA complex 7, which was found to be more active than cisplatin on both a cisplatin-sensitive and a cisplatin-resistant cell line.( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Molecular one-electron properties using the multireference Hartree,Fock CI method

A. M. C. Sobrinho
Abstract The recently introduced multireference Hartree,Fock configuration interaction (MRHFCI) method has been applied to the calculation of the dipole moment of the LiH, BH, FH, CO, and H2O molecules. The results obtained indicate that MRHFCI wave functions, much more compact but of the same quality of the orthogonal full CI ones, can provide better dipole moments than the corresponding full CI wave functions. The value of the dipole moments obtained with the MRHFCI wave functions is quite insensitive to the choice of the HF references but the same is not true for the electronic energy. Therefore, further studies are necessary to develop a criterion for selecting a set of HF references which could provide the best values of energy and dipole moment. Also, it would be important to verify if other one-electron properties can be computed with the same degree of accuracy obtained for the dipole moments. 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [source]

Optimization of cure kinetics parameter estimation for structural reaction injection molding/resin transfer molding

Robert J. Duh
A numerical method is proposed for polymer kinetic parameter estimation of either Structural Reaction Injection Molding (SRIM) or Resin Transfer Molding (RTM). The method simulates either radial flow or axial flow of reactive resins through a fiber preform inside a mold cavity. This method considers a non-isothermal environment with different inlet boundary conditions. Based on the molding conditions, this method can find the best values of chemical kinetic parameters by comparing the simulated temperature history and the experimental temperature history. Since the kinetic parameters are estimated with the real molding conditions, the simulations using these parameter values can have better agreement with molding data than those parameters which are obtained from idealized conditions such as Differential Scanning Calorimeter (DSC). The optimization approach was verified by estimating kinetics parameters for RTM data available in the literature. Temperatures predicted by the optimized kinetics parameters are compared with experimental data for two different molding conditions: injection of a thermally activated resin into a radial mold under constant pressure flow, and injection of a mix activated resin into a radial mold under constant volume. In both cases, the optimized kinetics parameters fit the temperature data well. [source]

New Centrifugal Blood Pump With Dual Impeller and Double Pivot Bearing System: Wear Evaluation in Bearing System, Performance Tests, and Preliminary Hemolysis Tests

Eduardo Bock
Abstract:, A new dual impeller centrifugal blood pump has been developed as a research collaboration between Baylor College of Medicine and Institute Dante Pazzanese of Cardiology for long-term left ventricle assist device (LVAD). A design feature of this new pump is a dual impeller that aims to minimize a stagnant flow pattern around the inlet port. Several different materials were tested in order to adopt a double pivot bearing design originally developed by Prof. Dr. Yukihiko Nos from Baylor College of Medicine. Hydraulic performance tests were conducted with two different inlet ports' angle configurations 30 and 45. Pump with inlet port angle of 45 achieved best values of pressure ahead and flow after 1800 rpm. Preliminary hemolysis tests were conducted using human blood. The pump showed good performance results and no alarming trace of hemolysis, proving to be a feasible long-term LVAD. [source]

Measuring ,M and ,, with long-duration gamma-ray bursts

A. Balastegui
Abstract Gamma-ray bursts (GRBs) are one of the most luminous events in the Universe. In addition, the Universe itself is almost transparent to , -rays, making GRBs detectable up to very high redshifts. As a result, GRBs are very suitable to probe the cosmological parameters. This work shows the potential of long-duration GRBs for measuring the cosmological parameters ,M and ,, by comparing the observed log N -log P distribution with the theoretical one. Provided that the GRBs rate and luminosity function are well determined, the best values and 1, confidence intervals obtained are ,M = 0.22+0.05,0.03 and ,, = 1.06+0.05,0.10. Finally, a set of simulations show the ability of the method to measure ,M and ,, ( 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Flat bulk-solvent model: obtaining optimal parameters

Andrei Fokine
A bulk-solvent correction is regularly used for macromolecular refinement. The flat model of the bulk solvent is considered to be the most reliable. It is shown that the standard procedure does not always result in the optimal values of the bulk-solvent correction parameters. A method to obtain the best values for parameters ksol and Bsol of the flat-solvent model is discussed. The values of correctly determined parameters for crystallographic structures deposited in the Protein Data Bank are clustered around ksol = 0.35,e,,3 and Bsol = 46,2, which have a reasonable physical meaning. Such a distribution allows the use of these mean values of solvent parameters for many practical applications when refined parameters cannot be obtained, especially when an atomic model in the unit cell is not yet known. [source]