Home About us Contact
|
Home About us Contact | ||
|
|
||
Shortfall
Kinds of Shortfall Selected AbstractsHolistic investment assessment: optimization, risk appraisal and decision makingMANAGERIAL AND DECISION ECONOMICS, Issue 6 2009Georgios Tziralis Abstract On deciding for the most appropriate investment when capital restrictions exist, investors define their alternatives and analyze each one of them. Traditionally, the definition, appraisal and analysis stages are treated separately. Herein, an innovative holistic method is proposed for bridging these stages. Within this method, investment attributes definition occurs by genetic algorithm optimization, while the analysis of the investment is realized through simulation. The method also proposes the NPV Expected Shortfall and the NPV Risk Preference Index as investment evaluation criteria. An illustrative case study of two mutually exclusive renewable energy investment scenarios is also used for demonstration purposes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Estimating financial risk measures for futures positions: A nonparametric approachTHE JOURNAL OF FUTURES MARKETS, Issue 7 2010John Cotter This study presents nonparametric estimates of spectral risk measures (SRM) applied to long and short positions in five prominent equity futures contracts. It also compares these to estimates of two popular alternative measures, the Value-at-Risk and Expected Shortfall. The SRMs are conditioned on the coefficient of absolute risk aversion, and the latter two are conditioned on the confidence level. Our findings indicate that all risk measures increase dramatically and their estimators deteriorate in precision when their respective conditioning parameter increases. Results also suggest that estimates of SRMs and their precision levels are of comparable orders of magnitude as those of more conventional risk measures. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:689,703, 2010 [source] A comparison of alternative approaches for determining the downside risk of hedge fund strategiesTHE JOURNAL OF FUTURES MARKETS, Issue 3 2009Daniel Giamouridis In this study, we compare a number of different approaches for determining the Value at Risk (VaR) and Expected Shortfall (ES) of hedge fund investment strategies. We compute VaR and ES through both model-free and mean/variance and distribution model-based methods. Certain specifications of the models that we considered can technically address the typical characteristics of hedge fund returns such as autocorrelation, asymmetry, fat tails, and time-varying variances. We find that conditional mean/variance models coupled with appropriate assumptions on the empirical distribution can improve the prediction accuracy of VaR. In particular, we observed the highest prediction accuracy for the predictions of 1% VaR. We also find that the goodness of ES prediction models is primarily influenced by the distribution model rather than the mean/variance specification. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:244,269, 2009 [source] Fuel Cell Vehicle Simulation , Part 1: Benchmarking Available Fuel Cell Vehicle Simulation ToolsFUEL CELLS, Issue 3 2003K.H. Hauer Abstract Fuel cell vehicle simulation is one method for systematic and fast investigation of the different vehicle options (fuel choice, hybridization, reformer technologies). However, a sufficient modeling program, capable of modeling the different design options, is not available today. Modern simulation programs should be capable of serving as tools for analysis as well as development. Shortfalls of the existing programs, initially developed for internal combustion engine hybrid vehicles, are: (i)Insufficient modeling of transient characteristics; (ii) Insufficient modeling of the fuel cells system; (iii) Insufficient modeling of advanced hybrid systems; (iv) Employment of a non-causal (backwards looking) structure; (v) Significant shortcomings in the area of controls. In the area of analysis, a modeling tool for fuel cell vehicles needs to address the transient dynamic interaction between the electric drive train and the fuel cell system. Especially for vehicles with slow responding on-board fuel processor, this interaction is very different from the interaction between a battery (as power source) and an electric drive train in an electric vehicle design. Non-transient modeling leads to inaccurate predictions of vehicle performance and fuel consumption. When applied in the area of development, the existing programs do not support the employment of newer techniques, such as rapid prototyping. This is because the program structure merges control algorithms and component models, or different control algorithms (from different components) are lumped together in one single control block and not assigned to individual components as they are in real vehicles. In both cases, the transfer of control algorithms from the model into existing hardware is not possible. This paper is the first part of a three part series and benchmarks the "state of the art" of existing programs. The second paper introduces a new simulation program, which tries to overcome existing barriers. Specifically it explicitly recognizes the dynamic interaction between fuel cell system, drive train and optional additional energy storage. [source] Regulatory regimes and accountabilityREGULATION & GOVERNANCE, Issue 1 2007Peter J. May Abstract This research considers accountability issues for new forms of regulation that shift the emphasis from prescribing actions to regulating systems or regulating for results. Shortfalls at various levels of accountability are identified from experiences with these regimes in the regulation of building and fire safety, food safety and nuclear power plant safety. These experiences illustrate how accountability shortfalls can undermine regulatory performance and introduce a potential for subtle forms of regulatory capture. These concerns underscore the importance of finding the right fit between regulatory circumstances and the design of regulatory regimes. [source] Challenging Wallacean and Linnean shortfalls: knowledge gradients and conservation planning in a biodiversity hotspotDIVERSITY AND DISTRIBUTIONS, Issue 5 2006Luis Mauricio Bini ABSTRACT Knowledge about biodiversity remains inadequate because most species living on Earth were still not formally described (the Linnean shortfall) and because geographical distributions of most species are poorly understood and usually contain many gaps (the Wallacean shortfall). In this paper, we developed models to infer the size and placement of geographical ranges of hypothetical non-described species, based on the range size frequency distribution of anurans recently described in the Cerrado Biome, on the level of knowledge (number of inventories) and on surrogates for habitat suitability. The rationale for these models is as follow: (1) the range size frequency distribution of these species should be similar to the range-restricted species, which have been most recently described in the Cerrado Biome; (2) the probability of new discoveries will increase in areas with low biodiversity knowledge, mainly in suitable areas, and (3) assuming range continuity, new species should occupy adjacent cells only if the level of knowledge is low enough to allow the existence of undiscovered species. We ran a model based on the number of inventories only, and two models combining effects of number of inventories and two different estimates of habitat suitability, for a total of 100 replicates each. Finally, we performed a complementary analysis using simulated annealing to solve the set-covering problem for each simulation (i.e. finding the smallest number of cells so that all species are represented at least once), using extents of occurrence of 160 species (131 real anuran species plus 29 new simulated species). The revised reserve system that included information about unknown or poorly sampled taxa significantly shifted northwards, when compared to a system based on currently known species. This main result can be explained by the paucity of biodiversity data in this part of the biome, associated with its relatively high habitat suitability. As a precautionary measure, weighted by the inferred distribution data, the prioritization of a system of reserves in the north part of the biome appears to be defensible. [source] Dispersal and egg shortfall in Monarch butterflies: what happens when the matrix is cleaned up?ECOLOGICAL ENTOMOLOGY, Issue 1 2010MYRON P. ZALUCKI 1. We use an individual-based model describing the life of a monarch butterfly, which utilises milkweeds both aggregated in patches and scattered across the wider landscape as a substrate for laying eggs. The model simplifies the metapopulation of milkweed habitat patches by representing them as a proportion of the overall landscape, with the rest of the landscape considered matrix, which may contain some low density of milkweed plants. 2. The model simulates the number of eggs laid daily by a butterfly as it searches for hosts. The likelihood of finding hosts is related to the density of plants and the search ability of the butterfly. For an empty matrix, remaining in a habitat patch results in more eggs laid. However individuals that are good searchers have almost equivalent success without remaining in a habitat patch. These individuals are most affected by the presence of hosts in the matrix. 3. Given realistic values of habitat patch availability, our model shows that the presence of plants at a low density in the matrix has a substantial impact on the number of eggs laid; removing these plants can reduce lifetime potential fecundity by ca. 20%. These results have implications for monarch butterflies inhabiting agricultural landscapes, in which genetically modified soybean that is resistant to herbicides has resulted in the decimation of milkweeds over large areas. [source] Measuring and Optimizing Portfolio Credit Risk: A Copula-based Approach,ECONOMIC NOTES, Issue 3 2004Annalisa Di Clemente In this work, we present a methodology for measuring and optimizing the credit risk of a loan portfolio taking into account the non-normality of the credit loss distribution. In particular, we aim at modelling accurately joint default events for credit assets. In order to achieve this goal, we build the loss distribution of the loan portfolio by Monte Carlo simulation. The times until default of each obligor in portfolio are simulated following a copula-based approach. In particular, we study four different types of dependence structure for the credit assets in portfolio: the Gaussian copula, the Student's t-copula, the grouped t-copula and the Clayton n-copula (or Cook,Johnson copula). Our aim is to assess the impact of each type of copula on the value of different portfolio risk measures, such as expected loss, maximum loss, credit value at risk and expected shortfall. In addition, we want to verify whether and how the optimal portfolio composition may change utilizing various types of copula for describing the default dependence structure. In order to optimize portfolio credit risk, we minimize the conditional value at risk, a risk measure both relevant and tractable, by solving a simple linear programming problem subject to the traditional constraints of balance, portfolio expected return and trading. The outcomes, in terms of optimal portfolio compositions, obtained assuming different default dependence structures are compared with each other. The solution of the risk minimization problem may suggest us how to restructure the inefficient loan portfolios in order to obtain their best risk/return profile. In the absence of a developed secondary market for loans, we may follow the investment strategies indicated by the solution vector by utilizing credit default swaps. [source] Malnutrition, poverty, and economic growthHEALTH ECONOMICS, Issue S1 2009Rasmus Heltberg Abstract This paper argues that indicators of anthropometric shortfall , especially low height and low weight-for-age , are uniquely suited for assessing absolute deprivation in developing countries. Anthropometric indicators are relatively precise, readily available for most countries, reflect the preferences and concerns of many poor people, consistent with reckoning the phenomenon directly in the space of functionings, intuitive, easy to use for advocacy, and consistent over time and across subgroups. Anthropometric indicators can therefore complement (but not replace) standard indicators of income/consumption poverty, especially for comparisons across subgroups, within households, across countries, and in the long run. In addition, the paper analyses spells of change in malnutrition over time, finding that the association between economic growth and chronic child malnutrition is very small (but statistically significant) and much lower than the elasticity of growth on poverty. The policy implication of this finding is that direct interventions aimed at reducing infant malnutrition are required. Copyright © 2009 John Wiley & Sons, Ltd. [source] Preparing the HR profession for technology and information workHUMAN RESOURCE MANAGEMENT, Issue 2-3 2004Paul S. Hempel Technology and human resource management have broad influences upon each other. Technology not only changes the administration of human resources (HR), which is the domain of e-HR, but also changes organizations and work. HR professionals must be able to adopt technologies that allow the reengineering of the HR function, be prepared to support organizational and work-design changes enabled by technology, and be able to support the proper managerial climate for innovative and knowledge-based organizations. An examination of HR professional degree programs shows that traditional HR education has poorly prepared the HR profession for these challenges. To address this shortfall, HR education must be revised to provide a greater focus on technological issues, and HR educators must acquire the skills needed to teach these courses. © 2004 Wiley Periodicals, Inc. [source] IHMS,Integrated Hydrological Modelling System.HYDROLOGICAL PROCESSES, Issue 19 2010Part 2. Abstract The integrated hydrological modelling system, IHMS, has been described in detail in Part 1 of this paper. The system comprises three models: Distributed Catchment Scale Model (DiCaSM), MODFLOW (v96 and v2000) and SWI. The DiCaSM simulates different components of the unsaturated zone water balance, including groundwater recharge. The recharge output from DiCaSM is used as input to the saturated zone model MODFLOW, which subsequently calculates groundwater flows and head distributions. The main objectives of this paper are: (1) to show the way more accurate predictions of groundwater levels in two Cyprus catchments can be obtained using improved estimates of groundwater recharge from the catchment water balance, and (2) to demonstrate the interface utility that simulates communication between unsaturated and saturated zone models and allows the transmission of data between the two models at the required spatial and temporal scales. The linked models can be used to predict the impact of future climate change on surface and groundwater resources and to estimate the future water supply shortfall in the island up to 2050. The DiCaSM unsaturated zone model was successfully calibrated and validated against stream flows with reasonable values for goodness of fit as shown by the Nash-Sutcliffe criterion. Groundwater recharge obtained from the successful tests was applied at various spatial and temporal scales to the Kouris and Akrotiri catchments in Cyprus. These recharge values produced good estimates of groundwater levels in both catchments. Once calibrated, the model was run using a number of possible future climate change scenarios. The results showed that by 2050, groundwater and surface water supplies would decrease by 35% and 24% for Kouris and 20% and 17% for Akrotiri, respectively. The gap between water supply and demand showed a linear increase with time. The results suggest that IHMS can be used as an effective tool for water authorities and decision makers to help balance demand and supply on the island. Copyright © 2010 John Wiley & Sons, Ltd. [source] Designing Macroeconomic Frameworks: A Positive Analysis of Monetary and Fiscal Delegation,INTERNATIONAL FINANCE, Issue 1 2005Francesca Castellani This paper proposes a simple model illustrating the potential benefits of approaching the design of a macroeconomic framework conducive to low inflation in both its monetary and fiscal dimensions rather than relying exclusively on the merits of central bank independence and other monetary commitment devices such as currency boards or dollarization. The reason is that monetary delegation alone merely ,relocates' the time-inconsistency problem stemming from the government's incentive to address structural output shortfall with a macroeconomic stimulus. This paper also provides a new argument explaining why fiscal deficit rules may be less effective than instrument-specific rules. [source] Solving the surgical waiting list problem?INTERNATIONAL JOURNAL OF HEALTH PLANNING AND MANAGEMENT, Issue 4 2000New Zealand's, booking system' Abstract This article discusses the development and implementation of New Zealand's booking system for publicly funded non-urgent surgical and medical procedures. The ,booking system' emerged out of New Zealand's core services debate and the government's desire to remove waiting lists. It was targeted for implementation by mid-1998. However, the booking system remains in an unsatisfactory state and a variety of problems have plagued its introduction. These include a lack of national consistency in the priority access criteria, failure to pilot the system and a shortfall in the levels of funding available to treat the numbers of patients whose priority criteria ,scores' deem them clinically eligible for surgery. The article discusses endeavours to address these problems. In conclusion, based on the New Zealand experience, the article provides lessons for policy-makers interested in introducing surgical booking systems. Copyright © 2000 John Wiley & Sons, Ltd. [source] Resource Allocation Auctions within FirmsJOURNAL OF ACCOUNTING RESEARCH, Issue 5 2007STANLEY BAIMAN ABSTRACT There is growing interest in the use of markets within firms. Proponents have noted that markets are a simple and efficient mechanism for allocating resources in economies in which information is dispersed. In contrast to the use of markets in the broader economy, the efficiency of an internal market is determined in large part by the endogenous contractual incentives provided to the participating, privately informed agents. In this paper, we study the optimal design of managerial incentives when resources are allocated by an internal auction market, as well as the efficiency of the resulting resource allocations. We show that the internal auction market can achieve first-best resource allocations and decisions, but only at an excessive cost in compensation payments. We then identify conditions under which the internal auction market and associated optimal incentive contracts achieve the benchmark second-best outcome as determined using a direct revelation mechanism. The advantage of the auction is that it is easier to implement than the direct revelation mechanism. When the internal auction mechanism is unable to achieve second-best, we characterize the factors that determine the magnitude of the shortfall. Overall, our results speak to the robust performance of relatively simple market mechanisms and associated incentive systems in resolving resource allocation problems within firms. [source] Attitudes of intensive care nurses towards brain death and organ transplantation: instrument development and testingJOURNAL OF ADVANCED NURSING, Issue 5 2006Jung Ran Kim BN MClinN DipN RN Aims., This paper reports the development and testing of an instrument assessing attitudes of Korean intensive care unit nurses. Background., Reluctance by healthcare professionals to identify brain-dead patients as a potential donor is one reason for a shortfall in transplantable organs in all countries. Organ donation from brain-dead patients is a particularly contentious issue in Korea, following recent legal recognition of brain death within the cultural context of Confucian beliefs. Method., A 38-item instrument was developed from the literature and key informant interviews, and validated by an expert panel and a pilot study. A survey was conducted with Korean intensive care unit nurses (n = 520) from October 2003 to January 2004. Principal component analysis with varimax rotation was used to determine construct validity. Item-to-total correlations and Cronbach's coefficient alpha were used to determine the scale's internal consistency and unidimensionality. Results., The scale demonstrated high internal consistency (alpha = 0·88). Principal component analysis yielded a four-component structure: Discomfort, Enhancing quality of life, Willingness to be a donor and Rewarding experience. Overall, Korean intensive care unit nurses showed positive attitudes towards organ transplantation, despite some mixed feelings. Conclusion., The attitude scale was reliable and valid for this cohort. Areas were identified where professional development may enhance positive attitudes towards organ transplantation from brain-dead donors. Effective education for intensive care unit nurses is necessary to increase the organ donor pool in Korea. Further research could test the instrument with other populations. [source] Asymmetric power distribution: Theory and applications to risk measurementJOURNAL OF APPLIED ECONOMETRICS, Issue 5 2007Ivana Komunjer Theoretical literature in finance has shown that the risk of financial time series can be well quantified by their expected shortfall, also known as the tail value-at-risk. In this paper, I construct a parametric estimator for the expected shortfall based on a flexible family of densities, called the asymmetric power distribution (APD). The APD family extends the generalized power distribution to cases where the data exhibits asymmetry. The first contribution of the paper is to provide a detailed description of the properties of an APD random variable, such as its quantiles and expected shortfall. The second contribution of the paper is to derive the asymptotic distribution of the APD maximum likelihood estimator (MLE) and construct a consistent estimator for its asymptotic covariance matrix. The latter is based on the APD score whose analytic expression is also provided. A small Monte Carlo experiment examines the small sample properties of the MLE and the empirical coverage of its confidence intervals. An empirical application to four daily financial market series reveals that returns tend to be asymmetric, with innovations which cannot be modeled by either Laplace (double-exponential) or Gaussian distribution, even if we allow the latter to be asymmetric. In an out-of-sample exercise, I compare the performances of the expected shortfall forecasts based on the APD-GARCH, Skew- t -GARCH and GPD-EGARCH models. While the GPD-EGARCH 1% expected shortfall forecasts seem to outperform the competitors, all three models perform equally well at forecasting the 5% and 10% expected shortfall. Copyright © 2007 John Wiley & Sons, Ltd. [source] Factors influencing Macao nurses' intention to leave current employmentJOURNAL OF CLINICAL NURSING, Issue 6 2009Moon Fai Chan Aims., To investigate factors associated with nurses' intention to leave current employment in Macao. Background., The shortage of nursing staff and nurses voluntarily leaving their jobs has continued to be a problem affecting the delivery of health care all over the world. One way to alleviate this shortfall is via recruitment, but this is not always successful. Another way is to reduce the rate at which nurses voluntarily leave their work places. Design., A descriptive survey was conducted and data were collected using a self-reported structured questionnaire. Nurses were recruited in the Health Bureau and one private hospital in Macao. The status of nurses' intention to leave current employment (yes vs. no) was the dependent variable and nurses' predisposing characteristics, organisational environments and five components on job satisfaction outcomes were independent variables. Results., Of 426 nurses, 166 (39·0%) indicated an intention to leave current employment. The results showed that age (p < 0·001), work experience (p < 0·001), workplace (p = 0·015) and job satisfaction: pay and benefits (p < 0·001) were significant risk factors to predict nurses' intention to leave current employment. Conclusions., More than one-third of the nurses in Macao indicated an intention to leave current employment. This figure may be a cause of concern for the hospital management and highlights the need to implement strategies to improve the communication between nurses and the organisation, to enhance nurse job satisfaction and commitment to the organisation. Relevance to clinical practice., Our findings outline some issues contributing to this problem and provide the nurse manager with information regarding specific influences on nurses' turnover in Macao. Given the complexity of issues outlined in this analysis, nurse managers should assist their nursing staff to deal with those influences, make efforts to address the nursing shortage that will require additional communications and recognise the needs and values of their staff and empower them to create a better work environment. As a consequence, their commitment to the organisation can be fostered. [source] Cellular senescence in pretransplant renal biopsies predicts postoperative organ functionAGING CELL, Issue 1 2009Liane M. McGlynn Summary Older and marginal donors have been used to meet the shortfall in available organs for renal transplantation. Post-transplant renal function and outcome from these donors are often poorer than chronologically younger donors. Some organs, however, function adequately for many years. We have hypothesized that such organs are biologically younger than poorer performing counterparts. We have tested this hypothesis in a cohort of pre-implantation human renal allograft biopsies (n = 75) that have been assayed by real-time polymerase chain reaction for the expression of known markers of cellular damage and biological aging, including CDKN2A, CDKN1A, SIRT2 and POT1. These have been investigated for any associations with traditional factors affecting transplant outcome (donor age, cold ischaemic time) and organ function post-transplant (serum creatinine levels). Linear regression analyses indicated a strong association for serum creatinine with pre-transplant CDKN2A levels (p = 0.001) and donor age (p = 0.004) at 6 months post-transplant. Both these markers correlated significantly with urinary protein to creatinine ratios (p = 0.002 and p = 0.005 respectively), an informative marker for subsequent graft dysfunction. POT1 expression also showed a significant association with this parameter (p = 0.05). Multiple linear regression analyses for CDKN2A and donor age accounted for 24.6% (p = 0.001) of observed variability in serum creatinine levels at 6 months and 23.7% (p = 0.001) at 1 year post-transplant. Thus, these data indicate that allograft biological age is an important novel prognostic determinant for renal transplant outcome. [source] Current practice in the management of children with cerebral palsy: a national survey of paediatric dietitiansJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 4 2003Hilary Hartley Abstract Background Dietitians play a key role in the clinical management of children with cerebral palsy. This survey was conducted with the aim of establishing an overview of current dietetic practice in the management of these children. Method A questionnaire which asked for information on aspects of dietetic practice relating to children with cerebral palsy was circulated to members of the British Dietetic Association during May to October 2000. Results Many respondents had a small caseload size. However, a larger caseload was linked to membership of a multi-disciplinary team, a greater proportion of severely disabled children and use of a wider range of anthropometric measurements. Dietitians who were members of a multi-disciplinary team were more likely to visit children at home. Conclusions This survey provides an overview of current dietetic practice in the UK regarding the management of children with cerebral palsy. There is a potential shortfall in specialist dietitians and this survey highlights some of the gaps in service provision. Children with cerebral palsy benefit from dietetic input and there is an increasing need for specialist dietitians to be involved in their management. It will be necessary to continue to identify any gaps and find ways to overcome them. [source] A ,Catch Up' Plan for radiotherapy in New South Wales to 2012JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009Graeme Morgan Summary In New South Wales (NSW) from 1996 to 2006, only 34,37% of newly diagnosed cancer patients were treated with radiotherapy instead of the 50% proposed by NSW Health in Radiotherapy Plans released in 1991, 1995 and 2003. As a consequence, over 50 000 cancer patients were not treated and has resulted in the estimated premature death of over 8000 patients and over 40 000 years of life lost. In 2008, there were 42 linear accelerators in NSW rather than the 62 recommended. Based on cancer incidence projections, NSW will require 69 linear accelerators in 2012 , a shortfall of 27 linear accelerators. Already 15 linear accelerators have been approved. NSW Health has funding for seven extra linear accelerators, and eight extra linear accelerators are to be funded by the private sector. To make up the shortfall, a ,Catch Up' Plan is proposed for an additional 12 linear accelerators by the end of fiscal year 2012. This is estimated to cost $200 million over 4 years for one-off establishment costs for buildings and equipment plus $50 million per year for recurrent operating costs such as staff salaries. The ,Catch Up' Plan will create five new departments of radiation oncology in country hospitals and three new departments in metropolitan hospitals. These will be in addition to those already approved by NSW Health and will markedly improve access for treatment and result in an improvement in cancer survival. This significant increase in departments and equipment can only be achieved by the creation of an NSW Radiotherapy Taskforce similar to that proposed in the Baume report of 2002, ,A vision for radiotherapy'. Even if the ,Catch Up' Plan bridges the gap in service provision, forward planning beyond 2012 should commence immediately as 76 linear accelerators will be required for NSW in 2015 and 81 linear accelerators in 2017. [source] Mechanism of the protective effect of hypothermia on ammonia toxicity in astrocytesJOURNAL OF NEUROCHEMISTRY, Issue 2002C. Zwingmann Ammonia is a key factor in the pathogenesis of hepatic encephalopathy (HE). Acute ammonia treatment causes energy failure of astrocytes, which are able to compensate partly by increased anaerobic metabolism as a means of making up for the energetic shortfall. As hypothermia offers protection from severe encephalopathy and lactate accumulation in liver failure, we investigated the mechanism by which hypothermia protects against ammonia toxicity by multinuclear NMR spectroscopy. 12 h exposure to 5 mm NH4CL decreased the phosphocreatine (PCr)/creatine (Cr) and ATP/ADP ratios to 65 and 76% of control, increased synthesis and release of glutamine to 200,250% and led to a significant stimulation of glycolytic activity reflected by increased uptake and consumption of glucose and accumulation of de novo synthesized intra- and extracellular lactate to 161 and 230% of control. The protective effect of mild hypothermia was evident from inhibiton of lactate accumulation and restoration of ammonia-induced depletion of PCr/Cr. Moderate hypothermia led to an increase of PCr/Cr ratio and inhibited lactate synthesis to 14% of normothermic control, but did not prevent the ATP decrease. While hypothermia inhibited glycolytic flux, intracellular glutamine remained elevated. The results suggest that hypothermia-induced protection against ammonia toxicity results from reduction of cellular energy demand leading to inhibition of anaerobic glucose metabolism and a compensatory stimulation of mitochondrial energy production. Acknowledgements:, Funded by CIHR Canada. [source] Locally targeted initiatives to recruit and retain nurses in EnglandJOURNAL OF NURSING MANAGEMENT, Issue 4 2006DINAH GOULD BSc MPhil PhD RGN RNT Aim, The aim of this study is to provide a detailed account of the locally targeted strategies to improve staffing levels by senior nurses responsible for recruitment and retention in acute trusts in the National Health Service in England. Background, There is a shortfall in nursing numbers throughout England. Some trusts have employed senior nurses with a specific remit to improve recruitment and retention, but little has been published about their work or its success. Methods, Data were collected by telephone using semi-structured interviews with standard probes. The tape-recorded interview data were transcribed verbatim and analysed by content. Results, Of the 156 acute trusts in England, 36 employed a senior nurse to deal with recruitment and retention. Twenty-nine were interviewed. All were using a range of locally targeted initiatives to attract and retain health-care assistants, newly qualified and more experienced practitioners. They also worked closely with university staff to attract and retain student nurses who would later seek employment locally. Different approaches were used to secure the services of different types of staff. Conclusion, This exploratory study has revealed a wealth of valuable data concerning locally targeted recruitment and retention strategies. Further research is needed to examine the effectiveness and cost-effectiveness of the initiatives described. [source] Analysis of Participating Life Insurance Contracts: A Unification ApproachJOURNAL OF RISK AND INSURANCE, Issue 3 2007Nadine Gatzert Fair pricing of embedded options in life insurance contracts is usually conducted by using risk-neutral valuation. This pricing framework assumes a perfect hedging strategy, which insurance companies can hardly pursue in practice. In this article, we extend the risk-neutral valuation concept with a risk measurement approach. We accomplish this by first calibrating contract parameters that lead to the same market value using risk-neutral valuation. We then measure the resulting risk assuming that insurers do not follow perfect hedging strategies. As the relevant risk measure, we use lower partial moments, comparing shortfall probability, expected shortfall, and downside variance. We show that even when contracts have the same market value, the insurance company's risk can vary widely, a finding that allows us to identify key risk drivers for participating life insurance contracts. [source] Nash bargaining over allocations in inventory pooling contractsNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 6 2008Eran Hanany Abstract When facing uncertain demand, several firms may consider pooling their inventories leading to the emergence of two key contractual issues. How much should each produce or purchase for inventory purposes? How should inventory be allocated when shortages occur to some of the firms? Previously, if the allocations issue was considered, it was undertaken through evaluation of the consequences of an arbitrary priority scheme. We consider both these issues within a Nash bargaining solution (NBS) cooperative framework. The firms may not be risk neutral, hence a nontransferable utility bargaining game is defined. Thus the physical pooling mechanism itself must benefit the firms, even without any monetary transfers. The firms may be asymmetric in the sense of having different unit production costs and unit revenues. Our assumption with respect to shortage allocation is that a firm not suffering from a shortfall, will not be affected by any of the other firms' shortages. For two risk neutral firms, the NBS is shown to award priority on all inventory produced to the firm with higher ratio of unit revenue to unit production cost. Nevertheless, the arrangement is also beneficial for the other firm contributing to the total production. We provide examples of Uniform and Bernoulli demand distributions, for which the problem can be solved analytically. For firms with constant absolute risk aversion, the agreement may not award priority to any firm. Analytically solvable examples allow additional insights, e.g. that higher risk aversion can, for some problem parameters, cause an increase in the sum of quantities produced, which is not the case in a single newsvendor setting. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008 [source] Refining crisis deepens as capacity is lost on both sides of AtlanticOIL AND ENERGY TRENDS, Issue 10 2005Article first published online: 17 OCT 200 The devastation by the arrival of hurricanes in rapid succession on the US Gulf Coast highlights how finely balanced the world's refined product supply chain is. Gasoline prices hit record highs around the world as the first of the two hurricanes, Katrina, moved onshore into Louisiana and Mississippi, knocking out some 2.4 mn bpd of refinery capacity. The arrival of its sister storm, Rita, put a further 4.1 mn bpd out of action in Texas whilst nearly 0.9 m bpd remained closed in the aftermath of Katrina. Refiners across the world strove to make up the shortfall in gasoline and other light distillates from the US, only to find in many cases there were insufficient clean tankers to ship the product to the US Gulf. [source] Petroleum product scarcity: a review of the supply and distribution of petroleum products in NigeriaOPEC ENERGY REVIEW, Issue 1 2006Osi S. Akpoghomeh Nigeria ranks high among the comity of oil producers both at the world level and among the OPEC eleven. It is, therefore, paradoxical that the supply of all petroleum products is erratic and has declined sharply in the recent past. This paper thus reviews the petroleum product supply and distribution systems in the country to ascertain the extent to which the system may have contributed to the present product scarcity in Nigeria and, by extension, identify the causes of the present regime of petroleum product scarcity. The paper observes that the network density and connectivity of petroleum product distribution pipelines are low and both indicators consequently show the inadequacy/deficiency of the network in ensuring an efficient distribution system. The supply mode, on the other hand, has, over the years, demonstrated its inability to guarantee adequate supply due to factors including sabotage, vandalism, banditry and poorly maintained infrastructure. Further, the federal government and the major and independent marketers could not sustain the importation of petroleum products because of the shortfall between the landed cost of imported products and their selling prices in Nigeria, which made the business unprofitable. Finally, the paper examines the withdrawal by the federal government of subsidies on the price of petroleum products consumed locally. All the above factors together occasioned increases in the cost of products. In conclusion, this paper supports the call for the privatization of refineries and the depot/pipeline system as a viable option to end the supply problems. [source] The evolution of a performance analysis job aidPERFORMANCE IMPROVEMENT, Issue 10 2008Roger Chevalier Managers and supervisors routinely identify performance shortfalls and their causes as they attempt to create work environments where their people can succeed. This article traces the development of a job aid for managers that provides the necessary structure to systematically and systemically determine performance gaps, identify weight, and display the underlying causes of a performance shortfall. While managers are the target audience, performance consultants may also find the job aid a useful tool. [source] Policies to Reconcile Labor Force Participation and Childbearing in the European UnionPOPULATION AND DEVELOPMENT REVIEW, Issue 2 2006Article first published online: 26 JUN 200 A recently published report commissioned by the Directorate-General for Employment, Social Affairs and Equal Opportunities of the European Commission reviews "reconciliation" policies in 30 European countries. Such policies are defined by the report in its title as measures that foster "reconciliation of work and private life" or, more elaborately in the body of the report, as "policies that directly support the combination of professional, family and private life." In this context work means gainful employment, while private life in effect means childbearing. The countries covered are those of the EU 25, two candidate countries (Bulgaria and Romania), and three countries that are part of the European Economic Area (Iceland, Norway, and Liechtenstein). The report, not formally endorsed by the Commission, was prepared by the EU Expert Group on Gender, Social Inclusion and Employment. Each of the 30 countries was represented by at least one expert. The 96-page report identifies four types of reconciliation policies: childcare services, leave facilities, flexible working-time arrangements, and financial allowances. Descriptions of these policies from the Executive Summary are reproduced below. The full report is accessible at «http://bookshop.eu.int/eubookshop/FileCache/PUBPDF/KE6905828ENC/KE6905828ENC_002.pdf». Although the report makes passing reference to below-replacement fertility in the EU member countries, its focus is clearly directed to measures that could increase the rate of employment, especially female employment. According to the EU's "Lisbon targets" set in 2000, the female employment rate in the EU should be raised to 60 percent of the working-age population by 2010. Based on data for 2003, only eight EU countries have met or exceeded this target. Childbearing is seen as in part responsible for the shortfall. Reconciliation policies could make the Lisbon target for female employment more easily achievable and "especially stimulate full time participation." Furthermore, the report suggests, such policies, as a byproduct, could also enhance fertility. Financial allowances, paid directly to families with children, the fourth type of policy discussed by the report, include measures reminiscent of the main thrust of the newly announced proposals for increasing fertility in Russia (see the preceding Documents item in this issue). The report, however, makes no reference to differentiation by parity, a distinctive mark of pronatalist intent. Indeed, it specifies that "family-based tax concessions and family allowances are not part of the reconciliation policy per se," noting, with an apparent element of disapproval, that such provisions "are often based on (and may reinforce the notion of) a traditional breadwinner model by reducing the incentive to work for both spouses." [source] Unbiased ensemble square root filtersPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2007S. L. Dance Ensemble square root filters are a method of data assimilation, where model forecasts are combined with observations to produce an improved state estimate, or analysis. There are a number of different algorithms in the literature and it is not clear which of these is the best for any given application. This work shows that in some implementations there can be a systematic bias in the analysis ensemble mean and consequently an accompanying shortfall in the spread of the analysis ensemble as expressed by the ensemble covariance matrix. We have established a set of necessary and sufficient conditions for the scheme to be unbiased. While these conditions are not a cure-all and cannot deal with independent sources of bias such as model and observation errors, they should be useful to designers of ensemble square root filters in the future. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Robustness of shortfall risk minimising strategies in the binomial modelPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003Gino Favero In this paper we study the dependence on the loss function of the strategy which minimises the expected shortfall risk when dealing with a financial contingent claim in the particular situation of a binomial model. After having characterised the optimal strategies in the particular cases when the loss function is concave, linear or strictly convex, we analyse how optimal strategies change when we approximate a loss function with a sequence of suitable loss functions. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||