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Severe Limitations (severe + limitation)
Selected AbstractsCapitation funding in the public sectorJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 2 2001Peter C. Smith A fundamental requirement of government at all levels,national and local,is to distribute the limited funds that it wishes to spend on particular public services between geographical areas or institutions, which are effectively competitors for such funds. Increasing use is now being made of capitation methods for such purposes, in which a standard estimate of expected expenditure is attached to a citizen with given characteristics. Statistical methods are playing an important role in determining such capitations, but they give rise to profound methodological problems. This paper examines the rationale for capitation and discusses the associated methodological issues. It illustrates the issues raised with two examples taken from the UK public sector: in personal social services and hospital care. Severe limitations of the data mean that small area data are used as the unit of observation, giving rise to considerable complexity in the model to be estimated. As a result, a range of methodologies including two-stage least squares and multilevel modelling methods are deployed. The paper concludes with a suggestion for an approach which would represent an improvement on current capitation methods, but which would require data on individuals rather than on small areas. [source] Patient Satisfaction With the External Equipment of Implantable Left Ventricular Assist DevicesARTIFICIAL ORGANS, Issue 9 2010Anna L. Meyer Abstract Patient satisfaction with left ventricular assist device (LVAD) external equipment has not yet been reported. We aimed to evaluate the quality of two different systems based on patients' perspective and its interrelationship with quality of life. Differential assessment of the HeartMate II axial flow pump (n = 17; Thoratec, Pleasanton, CA, USA) and the HVAD centrifugal pump (n = 10; HeartWare, Inc., Miramar, FL, USA) was obtained from 27 outpatients by a questionnaire 2 months to 2.9 years after device implantation. In addition, a health-related quality of life questionnaire (Short Form-36 [SF-36]) was completed. Overall patients' satisfaction was high. Severe limitations were attributed to the loudness of the power base unit in HeartMate II patients (P = 0.00), and HVAD patients were dissatisfied by the length of the driveline (P = 0.02). Between HVAD and HeartMate II patients, no significant differences in the quality of life (assessed by SF-36) were reported. While the overall satisfaction of outpatients on LVAD support was high, differences between the systems were found. Patients' perspectives may have an important impact on future modification of external components. Ultimately, this may also contribute to an improvement in the quality of life of chronic LVAD patients. [source] An efficient out-of-core multifrontal solver for large-scale unsymmetric element problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2009J. K. Reid Abstract In many applications where the efficient solution of large sparse linear systems of equations is required, a direct method is frequently the method of choice. Unfortunately, direct methods have a potentially severe limitation: as the problem size grows, the memory needed generally increases rapidly. However, the in-core memory requirements can be limited by storing the matrix and its factors externally, allowing the solver to be used for very large problems. We have designed a new out-of-core package for the large sparse unsymmetric systems that arise from finite-element problems. The code, which is called HSL_MA78, implements a multifrontal algorithm and achieves efficiency through the use of specially designed code for handling the input/output operations and efficient dense linear algebra kernels. These kernels, which are available as a separate package called HSL_MA74, use high-level BLAS to perform the partial factorization of the frontal matrices and offer both threshold partial and rook pivoting. In this paper, we describe the design of HSL_MA78 and explain its user interface and the options it offers. We also describe the algorithms used by HSL_MA74 and illustrate the performance of our new codes using problems from a range of practical applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Variation in resistance to the root-knot nematode Meloidogyne incognita in tomato genotypes bearing the Mi genePLANT PATHOLOGY, Issue 2 2005M. Jacquet Root-knot nematodes (Meloidogyne spp.) are among the main pathogens of tomato (Lycopersicon esculentum) worldwide. Plant resistance is currently the method of choice for controlling these pests and all the commercially available resistant cultivars carry the dominant Mi gene, which confers resistance to the three main species Meloidogyne arenaria, M. incognita and M. javanica. However the emergence of virulent biotypes able to overcome the tomato resistance gene may constitute a severe limitation to such a control strategy. To date, little was known of the possible influence of the homozygous vs heterozygous allelic state of the Mi locus, or the tomato genetic background, on the expression of the resistance. In order to test both these factors, the resistance was evaluated of a large panel of L. esculentum genotypes (selected from the Vilmorin germplasm stock collection) to seven M. incognita lines avirulent or virulent against the Mi gene. Plant resistance was estimated by counting the egg masses on the root systems after inoculation with second-stage juveniles (J2). Reproduction of the nematodes was similar or, more often, significantly higher on heterozygous tomato genotypes than on homozygous ones, suggesting a possible dosage effect of the Mi gene. Data also indicated that the tomato genetic background had a major effect on the variations observed in nematode reproduction, especially when tomato genotypes were heterozygous for the Mi gene. These results have important consequences in terms of breeding strategies and durability of the resistance conferred by the Mi gene. [source] Silica-Based, Organically Modified Host Material for Waveguide Structuring by Two-Photon-Induced PhotopolymerizationADVANCED FUNCTIONAL MATERIALS, Issue 5 2010Stefan Krivec Abstract The three-dimensional fabrication of optical waveguides has gained increasing interest in recent years to establish interconnections between electrical components on a very small scale where copper circuits encounter severe limitations. In this work the application of optically clear, organically modified porous silica monoliths and thin films as a host material for polymeric waveguides to be inscribed into the solid host structure by two-photon-induced photopolymerization is investigated. Porosity is generated using a lyotropic liquid crystalline surfactant/solvent system as a template for the solid silica material obtained by a sol,gel transition of a liquid precursor. In order to reduce the brittleness of the purely inorganic material, organic,inorganic co-precursor molecules that contain poly(ethylene glycol) chains are synthesized and added to the mixture, which successfully suppresses macroscopic cracking and leads to flexible thin films. The structure of the thus-obtained porous organic,inorganic hybrid material is investigated by atomic force microscopy. It is shown that the modified material is suitable for infiltration with photocurable monomers and functional polymeric waveguides can be inscribed by selective two-photon-induced photopolymerization. [source] Neither Romance Nor Regulation: Re-evaluating CommunityINTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 3 2006JAMES DEFILIPPIS As the realm of the community has grown increasingly important in the contemporary political economy, the theoretical debates surrounding community have also grown in importance and volume. Too often this literature has been either celebratory or dismissive; either romanticizing the concept and thereby elevating it to primary rank as the focal point of societal initiatives, or objecting to its regulated limits and contradictions and thereby dismissing its importance and political utility. There are important contributions being made by both those who dismiss community and those who celebrate it. But for those interested in understanding the potential for emancipatory social change in the contemporary political economy of neoliberalism there are also severe limitations imposed by these perspectives. After critiquing these literatures and debates, we put forward an understanding of community that is neither dismissive nor celebratory, but instead argues that communities need to be understood as simultaneously products of both their larger, and largely external, contexts, and the practices, organizations and relations that take place within them. Thus, communities, because of their central place in capitalist political economies, can be vital arenas for social change. But they are also arenas that are constrained in their capacities to host such efforts. [source] Possibilities and challenges in occupational injury surveillance of day laborersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2010Sarah J. Lowry MPH Abstract Background Day laborers in the US, comprised largely of undocumented immigrants from Mexico and Central America, suffer high rates of occupational injury according to recent estimates. Adequate surveillance methods for this highly transient, largely unregulated group do not currently exist. This study explores chart abstraction of hospital-based trauma registry records as a potential injury surveillance method for contingent workers and day laborers. We sought to determine the degree of completeness of work information in the medical records, and to identify day laborers and contingent workers to the extent possible. Methods Work-related injury cases from a hospital-based trauma registry (2001,2006) were divided by ethnicity (Hispanic vs. non-Hispanic origin) and presence of social security number (SSN: yes, no), resulting in four groups of cases. Medical records were abstracted for 40 cases from each group; each case was assigned values for the variables "day labor status" (yes, no, probably not, probable, unknown) and "employment type" (contingent, formal, unknown). Results Work information was missing for 60% of Hispanic cases lacking SSN, as compared with 33,47% of the other three groups. One "probable" day laborer was identified from the same group. Non-Hispanics with SSN were less frequently identified as contingent workers (5% as compared with 15,19%). Conclusions This method revealed severe limitations, including incomplete and inconsistent information in the trauma registry and medical records. Approaches to improve existing resources for use in surveillance systems are identified. The potential of an active surveillance approach at day labor hiring centers is also briefly discussed. Am. J. Ind. Med. 53:126,134 2010. © 2009 Wiley-Liss, Inc. [source] Modeling process flow using diagramsQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 4 2010Benjamin Kemper Abstract In the practice of process improvement, tools such as the flowchart, the value-stream map (VSM), and a variety of ad hoc variants of such diagrams are commonly used. The purpose of this paper is to present a clear, precise, and consistent framework for the use of such flow diagrams in process improvement projects. The paper finds that traditional diagrams, such as the flowchart, the VSM, and OR-type of diagrams, have severe limitations, miss certain elements, or are based on implicit but consequential premises. These limitations restrict the applicability of traditional diagrams in non-manufacturing areas such as service and healthcare processes. We show that a rational reconstruction for the use of diagrams in various disciplines regarding process flow boils down to a generic framework of elements, definitions of generic process metrics, and three classes of applications, namely the ,as-is', ,could-be', and ,should-be' analysis. The goal is not to replace all currently used diagrams, but merely to discuss the role of diagram usage in process flow modeling. This paper provides an explicit framework that is unambiguous and flexible, and has the potential to serve as a guideline for the practitioner, in manufacturing as well as in service and healthcare. Besides, it may serve as a starting point to develop an ontology of business processes. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||