995 resultados para Baccalaureate addresses.
Resumo:
To better understand long term adherence to self-care activities to prevent the recurrence of venous leg ulcers, participants (n=80) were recruited to a prospective longitudinal study after experiencing healing of a venous leg ulcer. Data on demographics, health, psychosocial measures and adherence to prevention strategies (compression therapy, leg elevation and lower leg exercise) were collected every three months for one year after healing. Multivariable regression modelling was used to identify the factors that were independently associated with adherence. Over the year, a significant decline in adherence to all three strategies was observed, predominantly between 6–12 months after healing (p<0.01). Several factors were associated with adherence to more than one preventive activity. Regular follow-up care and a history of multiple previous ulcers were related to improved adherence (p<0.05), while scoring at higher risk for depression and restricted mobility were related to decreasing adherence over time (p<0.05). Patients with osteoarthritis had significantly reduced adherence to compression hosiery (p=0.026). These results provide information to assist care providers plan strategies for prevention of recurrent venous leg ulcers; and suggest a need for regular follow-up care which addresses both the physical and mental health of this population.
Resumo:
In Chapters 1 through 9 of the book (with the exception of a brief discussion on observers and integral action in Section 5.5 of Chapter 5) we considered constrained optimal control problems for systems without uncertainty, that is, with no unmodelled dynamics or disturbances, and where the full state was available for measurement. More realistically, however, it is necessary to consider control problems for systems with uncertainty. This chapter addresses some of the issues that arise in this situation. As in Chapter 9, we adopt a stochastic description of uncertainty, which associates probability distributions to the uncertain elements, that is, disturbances and initial conditions. (See Section 12.6 for references to alternative approaches to model uncertainty.) When incomplete state information exists, a popular observer-based control strategy in the presence of stochastic disturbances is to use the certainty equivalence [CE] principle, introduced in Section 5.5 of Chapter 5 for deterministic systems. In the stochastic framework, CE consists of estimating the state and then using these estimates as if they were the true state in the control law that results if the problem were formulated as a deterministic problem (that is, without uncertainty). This strategy is motivated by the unconstrained problem with a quadratic objective function, for which CE is indeed the optimal solution (˚Astr¨om 1970, Bertsekas 1976). One of the aims of this chapter is to explore the issues that arise from the use of CE in RHC in the presence of constraints. We then turn to the obvious question about the optimality of the CE principle. We show that CE is, indeed, not optimal in general. We also analyse the possibility of obtaining truly optimal solutions for single input linear systems with input constraints and uncertainty related to output feedback and stochastic disturbances.We first find the optimal solution for the case of horizon N = 1, and then we indicate the complications that arise in the case of horizon N = 2. Our conclusion is that, for the case of linear constrained systems, the extra effort involved in the optimal feedback policy is probably not justified in practice. Indeed, we show by example that CE can give near optimal performance. We thus advocate this approach in real applications.
Resumo:
This article addresses the problem of estimating the Quality of Service (QoS) of a composite service given the QoS of the services participating in the composition. Previous solutions to this problem impose restrictions on the topology of the orchestration models, limiting their applicability to well-structured orchestration models for example. This article lifts these restrictions by proposing a method for aggregate QoS computation that deals with more general types of unstructured orchestration models. The applicability and scalability of the proposed method are validated using a collection of models from industrial practice.
Resumo:
This paper addresses the problem of joint identification of infinite-frequency added mass and fluid memory models of marine structures from finite frequency data. This problem is relevant for cases where the code used to compute the hydrodynamic coefficients of the marine structure does not give the infinite-frequency added mass. This case is typical of codes based on 2D-potential theory since most 3D-potential-theory codes solve the boundary value associated with the infinite frequency. The method proposed in this paper presents a simpler alternative approach to other methods previously presented in the literature. The advantage of the proposed method is that the same identification procedure can be used to identify the fluid-memory models with or without having access to the infinite-frequency added mass coefficient. Therefore, it provides an extension that puts the two identification problems into the same framework. The method also exploits the constraints related to relative degree and low-frequency asymptotic values of the hydrodynamic coefficients derived from the physics of the problem, which are used as prior information to refine the obtained models.
Resumo:
This paper addresses the problem of computing the aggregate QoS of a composite service given the QoS of the services participating in the composition. Previous solutions to this problem are restricted to composite services with well-structured orchestration models. Yet, in existing languages such as WS-BPEL and BPMN, orchestration models may be unstructured. This paper lifts this limitation by providing equations to compute the aggregate QoS for general types of irreducible unstructured regions in orchestration models. In conjunction with existing algorithms for decomposing business process models into single-entry-single-exit regions, these functions allow us to cover a larger set of orchestration models than existing QoS aggregation techniques.
Resumo:
This paper addresses the problem of transforming a process model with an arbitrary topology into an equivalent well-structured process model. While this problem has received significant attention, there is still no full characterization of the class of unstructured process models that can be transformed into well-structured ones, nor an automated method to structure any process model that belongs to this class. This paper fills this gap in the context of acyclic process models. The paper defines a necessary and sufficient condition for an unstructured process model to have an equivalent structured model under fully concurrent bisimulation, as well as a complete structuring method.
Resumo:
In Service-oriented Architectures, business processes can be realized by composing loosely coupled services. The problem of QoS-aware service composition is widely recognized in the literature. Existing approaches on computing an optimal solution to this problem tackle structured business processes, i.e., business processes which are composed of XOR-block, AND-block, and repeat loop orchestration components. As of yet, OR-block and unstructured orchestration components have not been sufficiently considered in the context of QoS-aware service composition. The work at hand addresses this shortcoming. An approach for computing an optimal solution to the service composition problem is proposed considering the structured orchestration components, such as AND/XOR/OR-block and repeat loop, as well as unstructured orchestration components.
Resumo:
Traction force microscopy (TFM) is commonly used to estimate cells’ traction forces from the deformation that they cause on their substrate. The accuracy of TFM highly depends on the computational methods used to measure the deformation of the substrate and estimate the forces, and also on the specifics of the experimental set-up. Computer simulations can be used to evaluate the effect of both the computational methods and the experimental set-up without the need to perform numerous experiments. Here, we present one such TFM simulator that addresses several limitations of the existing ones. As a proof of principle, we recreate a TFM experimental set-up, and apply a classic 2D TFM algorithm to recover the forces. In summary, our simulator provides a valuable tool to study the performance, refine experimentally, and guide the extraction of biological conclusions from TFM experiments.
Resumo:
In 2009 the world experienced an influenza pandemic caused by the H1N1 virus. While the pandemic was milder then expected, it nonetheless provided the world with an opportunity to do real-time testing of pandemic preparedness. This paper examines the threats to human health posed by infectious diseases and the challenges for the global community in development of effective surveillance systems for emerging infectious diseases. In 2005 a new revised version of the International Health Regulations (IHR) was adopted. The requirements of the IHR (2005) are outlined and considered in light of the constraints facing resource-poor countries. Finally, the paper addresses the role of domestic law-making in supporting public health preparedness and articulates a number of ethical principles that should be considered when developing new public health laws.
Resumo:
Background: Display technologies which allow peptides or proteins to be physically associated with the encoding DNA are central to procedures which involve screening of protein libraries in vitro for new or altered function. Here we describe a new system designed specifically for the display of libraries of diverse, functional proteins which utilises the DNA binding protein nuclear factor κB (NF-κB) p50 to establish a phenotype–genotype link between the displayed protein and the encoding gene. Results: A range of model fusion proteins to either the amino- or carboxy-terminus of NF-κB p50 have been constructed and shown to retain the picomolar affinity and DNA specificity of wild-type NF-κB p50. Through use of an optimal combination of binding buffer and DNA target sequence, the half-life of p50–DNA complexes could be increased to over 47 h, enabling the competitive selection of a variety of protein–plasmid complexes with enrichment factors of up to 6000-fold per round. The p50-based plasmid display system was used to enrich a maltose binding protein complex to homogeneity in only three rounds from a binary mixture with a starting ratio of 1:108 and to enrich to near homogeneity a single functional protein from a phenotype–genotype linked Escherichia coli genomic library using in vitro functional selections. Conclusions: A new display technology is described which addresses the challenge of functional protein display. The results demonstrate that plasmid display is sufficiently sensitive to select a functional protein from large libraries and that it therefore represents a useful addition to the repertoire of display technologies.
Resumo:
Property in an elusive concept. In many respects it has been regarded as a source of authority to use, develop and make decisions about whatever is the subject matter of this right of ownership. This is true whether the holder of this right of ownership is a private entity or a public entity. Increasingly a right of ownership of this kind has been recognised not only as a source of authority but also as a mechanism for restricting or limiting and perhaps even prohibiting existing or proposed activities that impact upon the environment. It is increasingly therefore an instrument of control as much as an instrument of authorisation. The protection and conservation of the environment are ultimately a matter of the public interest. This is not to suggest that the individual holders of rights of ownership are not interested in protecting the environment. It is open to them to do so in the exercise of a right of ownership as a source of authorisation. However a right of ownership – whether private or public – has become increasingly the instrument according to which the environment is protected and conserved. This article addresses these issues from a doctrinal as well as a practical perspective about how the environment is managed. It does so in five ways: ●considering briefly property as a concept ●reviewing property in its historical context ●analysing property as a human right ●examining property in natural resources ●reviewing judicial approaches to property in natural resources.
Resumo:
Draws together essays from leading scholars on the challenges that arise for health, law, policy and ethics at the intersections of health, rights and globalization. This book addresses global issues in public health, globalization and bioethics, and globalization and biotechnology.
Resumo:
United States copyright law -- two streams of computer copyright cases form basis for 'look and feel' litigation, literary work stream and audiovisual work stream -- literary work stream focuses on structure -- audiovisual work steam addresses appearance -- case studies
Resumo:
Service-oriented architectures and Web services mature and have become more widely accepted and used by industry. This growing adoption increased the demands for new ways of using Web service technology. Users start re-combining and mediating other providers’ services in ways that have not been anticipated by their original provider. Within organisations and cross-organisational communities, discoverable services are organised in repositories providing convenient access to adaptable end-to-end business processes. This idea is captured in the term Service Ecosystem. This paper addresses the question of how quality management can be performed in such service ecosystems. Service quality management is a key challenge when services are composed of a dynamic set of heterogeneous sub-services from different service providers. This paper contributes to this important area by developing a reference model of quality management in service ecosystems. We illustrate the application of the reference model in an exploratory case study. With this case study, we show how the reference model helps to derive requirements for the implementation and support of quality management in an exemplary service ecosystem in public administration.
Resumo:
Background Display technologies which allow peptides or proteins to be physically associated with the encoding DNA are central to procedures which involve screening of protein libraries in vitro for new or altered function. Here we describe a new system designed specifically for the display of libraries of diverse, functional proteins which utilises the DNA binding protein nuclear factor κB (NF-κB) p50 to establish a phenotype-genotype link between the displayed protein and the encoding gene. Results A range of model fusion proteins to either the amino- or carboxy-terminus of NF-κB p50 have been constructed and shown to retain the picomolar affinity and DNA specificity of wild-type NF-κB p50. Through use of an optimal combination of binding buffer and DNA target sequence, the half-life of p50-DNA complexes could be increased to over 47 h, enabling the competitive selection of a variety of protein-plasmid complexes with enrichment factors of up to 6000-fold per round. The p50-based plasmid display system was used to enrich a maltose binding protein complex to homogeneity in only three rounds from a binary mixture with a starting ratio of 1:108 and to enrich to near homogeneity a single functional protein from a phenotype-genotype linked Escherichia coli genomic library using in vitro functional selections. Conclusions A new display technology is described which addresses the challenge of functional protein display. The results demonstrate that plasmid display is sufficiently sensitive to select a functional protein from large libraries and that it therefore represents a useful addition to the repertoire of display technologies.