40 resultados para Conceptual Referential Operational Schema

em Universit


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The World Health Organization (WHO) criteria for the diagnosis of osteoporosis are mainly applicable for dual X-ray absorptiometry (DXA) measurements at the spine and hip levels. There is a growing demand for cheaper devices, free of ionizing radiation such as promising quantitative ultrasound (QUS). In common with many other countries, QUS measurements are increasingly used in Switzerland without adequate clinical guidelines. The T-score approach developed for DXA cannot be applied to QUS, although well-conducted prospective studies have shown that ultrasound could be a valuable predictor of fracture risk. As a consequence, an expert committee named the Swiss Quality Assurance Project (SQAP, for which the main mission is the establishment of quality assurance procedures for DXA and QUS in Switzerland) was mandated by the Swiss Association Against Osteoporosis (ASCO) in 2000 to propose operational clinical recommendations for the use of QUS in the management of osteoporosis for two QUS devices sold in Switzerland. Device-specific weighted "T-score" based on the risk of osteoporotic hip fractures as well as on the prediction of DXA osteoporosis at the hip, according to the WHO definition of osteoporosis, were calculated for the Achilles (Lunar, General Electric, Madison, Wis.) and Sahara (Hologic, Waltham, Mass.) ultrasound devices. Several studies (totaling a few thousand subjects) were used to calculate age-adjusted odd ratios (OR) and area under the receiver operating curve (AUC) for the prediction of osteoporotic fracture (taking into account a weighting score depending on the design of the study involved in the calculation). The ORs were 2.4 (1.9-3.2) and AUC 0.72 (0.66-0.77), respectively, for the Achilles, and 2.3 (1.7-3.1) and 0.75 (0.68-0.82), respectively, for the Sahara device. To translate risk estimates into thresholds for clinical application, 90% sensitivity was used to define low fracture and low osteoporosis risk, and a specificity of 80% was used to define subjects as being at high risk of fracture or having osteoporosis at the hip. From the combination of the fracture model with the hip DXA osteoporotic model, we found a T-score threshold of -1.2 and -2.5 for the stiffness (Achilles) determining, respectively, the low- and high-risk subjects. Similarly, we found a T-score at -1.0 and -2.2 for the QUI index (Sahara). Then a screening strategy combining QUS, DXA, and clinical factors for the identification of women needing treatment was proposed. The application of this approach will help to minimize the inappropriate use of QUS from which the whole field currently suffers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Åknes is an active complex large rockslide of approximately 30?40 Mm3 located within the Proterozoic gneisses of western Norway. The observed surface displacements indicate that this rockslide is divided into several blocks moving in different directions at velocities of between 3 and 10 cm year?1. Because of regional safety issues and economic interests this rockslide has been extensively monitored since 2004. The understanding of the deformation mechanism is crucial for the implementation of a viable monitoring system. Detailed field investigations and the analysis of a digital elevation model (DEM) indicate that the movements and the block geometry are controlled by the main schistosity (S1) in gneisses, folds, joints and regional faults. Such complex slope deformations use pre-existing structures, but also result in new failure surfaces and deformation zones, like preferential rupture in fold-hinge zones. Our interpretation provides a consistent conceptual three-dimensional (3D) model for the movements measured by various methods that is crucial for numerical stability modelling. In addition, this reinterpretation of the morphology confirms that in the past several rockslides occurred from the Åknes slope. They may be related to scars propagating along the vertical foliation in folds hinges. Finally, a model of the evolution of the Åknes slope is presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Species delimitation has been invigorated as a discipline in systematics by an influx of new character sets, analytical methods, and conceptual advances. We use genetic data from 68 markers, combined with distributional, bioclimatic, and coloration information, to hypothesize boundaries of evolutionarily independent lineages (species) within the widespread and highly variable nominal fire ant species Solenopsis saevissima, a member of a species group containing invasive pests as well as species that are models for ecological and evolutionary research. Our integrated approach uses diverse methods of analysis to sequentially test whether populations meet specific operational criteria (contingent properties) for candidacy as morphologically cryptic species, including genetic clustering, monophyly, reproductive isolation, and occupation of distinctive niche space. We hypothesize that nominal S. saevissima comprises at least 4-6 previously unrecognized species, including several pairs whose parapatric distributions implicate the development of intrinsic premating or postmating barriers to gene flow. Our genetic data further suggest that regional genetic differentiation in S. saevissima has been influenced by hybridization with other nominal species occurring in sympatry or parapatry, including the quite distantly related Solenopsis geminata. The results of this study illustrate the importance of employing different classes of genetic data (coding and noncoding regions and nuclear and mitochondrial DNA [mtDNA] markers), different methods of genetic data analysis (tree-based and non-tree based methods), and different sources of data (genetic, morphological, and ecological data) to explicitly test various operational criteria for species boundaries in clades of recently diverged lineages, while warning against over reliance on any single data type (e.g., mtDNA sequence variation) when drawing inferences.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim: The relative effectiveness of different methods of prevention of HIV transmission is a subject of debate that is renewed with the integration of each new method. The relative weight of values and evidence in decision-making is not always clearly defined. Debate is often confused, as the proponents of different approaches address the issue at different levels of implementation. This paper defines and delineates the successive levels of analysis of effectiveness, and proposes a conceptual framework to clarify debate. Method / Issue: Initially inspired from work on contraceptive effectiveness, a first version of the conceptual framework was published in 1993 with definition of the Condom Effectiveness Matrix (Spencer, 1993). The framework has since integrated and further developed thinking around distinctions made between efficacy and effectiveness and has been applied to HIV prevention in general. Three levels are defined: theoretical effectiveness (ThE), use-effectiveness (UseE) and population use-effectiveness (PopUseE). For example, abstinence and faithfulness, as proposed in the ABC strategy, have relatively high theoretical effectiveness but relatively low effectiveness at subsequent levels of implementation. The reverse is true of circumcision. Each level is associated with specific forms of scientific enquiry and associated research questions: basic and clinical sciences with ThE; clinical and social sciences with UseE; epidemiology and social, economic and political sciences with PopUseE. Similarly, the focus of investigation moves from biological organisms, to the individual at the physiological and then psychological, social and ecological level, and finally takes as perspective populations and societies as a whole. The framework may be applied to analyse issues on any approach. Hence, regarding consideration of HIV treatment as a means of prevention, examples of issues at each level would be: ThE: achieving adequate viral suppression and non-transmission to partners; UseE: facility and degree of adherence to treatment and medical follow-up; PopUseE: perceived validity of strategy, feasibility of achieving adequate population coverage. Discussion: Use of the framework clarifies the questions that need to be addressed at all levels in order to improve effectiveness. Furthermore, the interconnectedness and complementary nature of research from the different scientific disciplines and the relative contribution of each become apparent. The proposed framework could bring greater rationality to the prevention effectiveness debate and facilitate communication between stakeholders.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Despite the tremendous amount of data collected in the field of ambulatory care, political authorities still lack synthetic indicators to provide them with a global view of health services utilization and costs related to various types of diseases. Moreover, public health indicators fail to provide useful information for physicians' accountability purposes. The approach is based on the Swiss context, which is characterized by the greatest frequency of medical visits in Europe, the highest rate of growth for care expenditure, poor public information but a lot of structured data (new fee system introduced in 2004). The proposed conceptual framework is universal and based on descriptors of six entities: general population, people with poor health, patients, services, resources and effects. We show that most conceptual shortcomings can be overcome and that the proposed indicators can be achieved without threatening privacy protection, using modern cryptographic techniques. Twelve indicators are suggested for the surveillance of the ambulatory care system, almost all based on routinely available data: morbidity, accessibility, relevancy, adequacy, productivity, efficacy (from the points of view of the population, people with poor health, and patients), effectiveness, efficiency, health services coverage and financing. The additional costs of this surveillance system should not exceed Euro 2 million per year (Euro 0.3 per capita).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

1 6 STRUCTURE OF THIS THESIS -Chapter I presents the motivations of this dissertation by illustrating two gaps in the current body of knowledge that are worth filling, describes the research problem addressed by this thesis and presents the research methodology used to achieve this goal. -Chapter 2 shows a review of the existing literature showing that environment analysis is a vital strategic task, that it shall be supported by adapted information systems, and that there is thus a need for developing a conceptual model of the environment that provides a reference framework for better integrating the various existing methods and a more formal definition of the various aspect to support the development of suitable tools. -Chapter 3 proposes a conceptual model that specifies the various enviromnental aspects that are relevant for strategic decision making, how they relate to each other, and ,defines them in a more formal way that is more suited for information systems development. -Chapter 4 is dedicated to the evaluation of the proposed model on the basis of its application to a concrete environment to evaluate its suitability to describe the current conditions and potential evolution of a real environment and get an idea of its usefulness. -Chapter 5 goes a step further by assembling a toolbox describing a set of methods that can be used to analyze the various environmental aspects put forward by the model and by providing more detailed specifications for a number of them to show how our model can be used to facilitate their implementation as software tools. -Chapter 6 describes a prototype of a strategic decision support tool that allow the analysis of some of the aspects of the environment that are not well supported by existing tools and namely to analyze the relationship between multiple actors and issues. The usefulness of this prototype is evaluated on the basis of its application to a concrete environment. -Chapter 7 finally concludes this thesis by making a summary of its various contributions and by proposing further interesting research directions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The issue of specificity of delusions in schizophrenia is still a matter of debate. The authors analyze the delusion formation in schizophrenia from a prototypical, phenomenological point of view, focusing on the subject's experience. This perspective links delusion formation to the autistic predisposition, which is considered here as the elementary phenotypic expression of the vulnerability to schizophrenia. Autism is viewed as a defective preconceptual (i.e., before language) attunement to the world. It impedes the individual's sharing of "common sense" with others and impairs the ability to project into the future. The development of delusions is illustrated, in part, by Klaus Conrad's work on the onset of paranoid schizophrenia. Delusions are viewed as transformations of the structure of experiencing. When threatened in future ability to be, the autistic, vulnerable person looks for the clues to becoming by attributing significance to disparate elements of the environment, which become self-referential. The link established between these disparate elements is based on universal characteristics that give the schizophrenic delusion a metaphysical quality. The transitivistic experience in delusions of control and omnipotence points to a specific way of crossing the border between "mine" and "yours" (disturbances of the experiencing "I"). What strikes a clinician in these delusions is that the normally tacit link between the sense of being and the sense of acting becomes quite apparent. The authors also propose a specificity in the themes of schizophrenic delusions. Delusions acquire a schizophrenic quality when ontological (i.e., universal) elements of the discourse between the locutor and the Other dominate at the expense of the worldly elements. It is emphasized that delusional content and form are dialectically related and hardly distinguishable. The authors consider the delusion formation as a phenomenon of emergence, a situation in which a new qualitative order arises from the reorganization of essentially unchanged elements. To consider schizophrenia as an emergent, particular way of experiencing, related to the autistic defect, has important consequences for research and for treatment. A dialectic exchange is needed between prototypical models generated by phenomenological inquiry and empirical, operational validation of testable aspects of such models.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction and Aims: The process of delivering erythropoiesis stimulating agents (ESAs) to hemodialysis patients (HD) is complex. Many European countries are requiring centers to document this process. To date, there has not been any comprehensive description of the operational aspects of ESA delivery in Europe. The objective of the Mercurius study was to describe the entire process of ESA delivery in dialysis centers. In addition, we explored the benefits of less frequent dosing. Methods: A conceptual model was developed to classify the sub-processes in the pharmacy, dialysis unit, waste unit, and back office. Within each dialysis unit activities associated with dose determination, ordering procedures, receipt and storage of ESAs, and ESA administration were measured. Within the pharmacy, ordering from supplier, receiving and storing, and delivering ESA to the dialysis unit were measured. The amount of time and materials associated with waste disposal and back office activities were also observed. We also evaluated the impact of less frequent dosing on the resources required to perform anemia management for HD patients. Structured interviews with staff were used to develop a comprehensive list of processes, sub-processes, and activities that are routinely followed to order, register, administer, and dispose of waste associated with ESAs. Each activity was evaluated to determine if less frequent dosing influenced the amount of resources required. A model was developed to estimate the change in resources consumed using less frequent dosing regimens. Results: Eight centers from 5 European countries (Belgium, France, Italy, Sweden, and Switzerland) participated in the study. The number of HD patients in each center ranged from 42 to 707 (mean=175). Across all of the centers, patients received a variety of dosing regimens (eg, TIW, BIW, QW and Q2W). The mean (±SD) time spent for the pharmacy to order an ESA from the supplier was 6.1 (±8.7) minutes; time spent in the dialysis unit and pharmacy for receiving and storing ESPs was 5.3 (±5.3) and 10.0 (±10.9) minutes, respectively; and time spent administering each injection was 6.4 (±6.5) minutes. Switching from current dosing practices to Q2W could decrease the mean number of syringes used from 12,420 to 5,085 per year. We estimate a reduction in the number of disinfective tissues and liquids of 58% and 71%, respectively by switching from current practice to dosing ESAs Q2W. Conclusions: There was significant variation in the time that it takes to perform routine ESA activities. We estimate that a reduction in resources required to manage anemia can be obtained by reducing the frequency of administration from the current mix of ESAs. These resources could be redeployed for patient care.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Phylogenomic databases provide orthology predictions for species with fully sequenced genomes. Although the goal seems well-defined, the content of these databases differs greatly. Seven ortholog databases (Ensembl Compara, eggNOG, HOGENOM, InParanoid, OMA, OrthoDB, Panther) were compared on the basis of reference trees. For three well-conserved protein families, we observed a generally high specificity of orthology assignments for these databases. We show that differences in the completeness of predicted gene relationships and in the phylogenetic information are, for the great majority, not due to the methods used, but to differences in the underlying database concepts. According to our metrics, none of the databases provides a fully correct and comprehensive protein classification. Our results provide a framework for meaningful and systematic comparisons of phylogenomic databases. In the future, a sustainable set of 'Gold standard' phylogenetic trees could provide a robust method for phylogenomic databases to assess their current quality status, measure changes following new database releases and diagnose improvements subsequent to an upgrade of the analysis procedure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Theory predicts that males adapt to sperm competition by increasing their investment in testis mass to transfer larger ejaculates. Experimental and comparative data support this prediction. Nevertheless, the relative importance of sperm competition in testis size evolution remains elusive, because experiments vary only sperm competition whereas comparative approaches confound it with other variables, in particular male mating rate. We addressed the relative importance of sperm competition and male mating rate by taking an experimental evolution approach. We subjected populations of Drosophila melanogaster to sex ratios of 1:1, 4:1, and 10:1 (female:male). Female bias decreased sperm competition but increased male mating rate and sperm depletion. After 28 generations of evolution, males from the 10:1 treatment had larger testes than males from other treatments. Thus, testis size evolved in response to mating rate and sperm depletion, not sperm competition. Furthermore, our experiment demonstrated that drift associated with sex ratio distortion limits adaptation; testis size only evolved in populations in which the effect of sex ratio bias on the effective population size had been compensated by increasing the numerical size. We discuss these results with respect to reproductive evolution, genetic drift in natural and experimental populations, and consequences of natural sex ratio distortion.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This review describes the advances in malaria antigen discovery and vaccine development using the long synthetic peptide platforms that have been made available during the past 5 years. The most recent technical developments regarding peptide synthesis with the optimized production of large synthetic fragments are discussed. Clinical trials of long synthetic peptides are also reviewed. These trials demonstrated that long synthetic peptides are safe and immunogenic when formulated with various adjuvants. In addition, long synthetic peptides can elicit an antibody response in humans and have demonstrated inhibitory activity against parasite growth in vitro. Finally, new approaches to exploit the abundance of genomic data and the flexibility and speed of peptide synthesis are proposed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Many definitions and debates exist about the core characteristics of social and solidarity economy (SSE) and its actors. Among others, legal forms, profit, geographical scope, and size as criteria for identifying SSE actors often reveal dissents among SSE scholars. Instead of using a dichotomous, either-in-or-out definition of SSE actors, this paper presents an assessment tool that takes into account multiple dimensions to offer a more comprehensive and nuanced view of the field. We first define the core dimensions of the assessment tool by synthesizing the multiple indicators found in the literature. We then empirically test these dimensions and their interrelatedness and seek to identify potential clusters of actors. Finally we discuss the practical implications of our model.