Psychometric properties of the disease-specific health-related quality of life instrument VascuQoL in a Swedish setting

Background: Traditional outcome measures in peripheral arterial disease (PAD) provide insufficient information regarding patient benefit. It has therefore been suggested to add patient-reported outcome measures. The main aim of this study was to validate the Swedish Vascular Quality of Life questionnaire (VascuQoL) version, a patient-reported PAD-specific health-related quality of life (HRQoL) instrument. Methods: Two-hundred PAD patients were consecutively recruited from two university hospitals. Out of the 200 subjects, 129 had intermittent claudication and 71 had critical limb ischemia. Mean age was 70 +/- 9 y and 57% of the participants were male. All patients completed SF-36 and VascuQoL at the vascular outpatient clinic, when evaluated for invasive treatment. Risk factors and physiological parameters were registered. Construct validity was tested by correlation analysis versus SF-36 and was also assessed with multitrait/multi-item scaling analysis (MTMI). Sensitivity analysis regarding disease severity identification was performed. Reliability was assessed with Cronbach's alpha and responsiveness by standardized response mean (SRM) calculations. Results: Significant correlations were demonstrated between relevant subscales of VascuQoL and SF-36. MTMI showed acceptable construct validity, but some scaling-errors. VascuQoL significantly (p < 0.001) discriminated claudicants from critical limb ischemia patients. Cronbach's alpha was 0.94 and SRM 1.02 (sum score). Conclusions: The Swedish version of VascuQoL is valid and quantifies central aspects of HRQoL in PAD patients. Sensitivity analysis showed high ability to differentiate between disease severity and SRM illustrated excellent responsiveness. The relative abundance of items however makes use in the everyday clinical setting somewhat difficult

Enabling application-level performance guarantees in network-based systems on chip by applying dataflow analysis

A growing number of applications, often with real-time requirements, are integrated on the same system on chip (SoC), in the form of hardware and software intellectual property (IP). To facilitate real-time applications, networks on chip (NoC) guarantee bounds on latency and throughput. These bounds, however, only extend to the network interfaces (NI), between the IP and the NoC. To give performance guarantees on the application level, the buffers in the NIs must be sufficiently large for the particular application. At the same time, it is imperative to minimise the size of the NI buffers, as they are major contributors to the area and power consumption of the NoC. Existing buffer-sizing methods use coarse-grained application models, based on linear traffic bounds or periodic producers and consumers, thus severely limiting their applicability. In this work, the authors propose to capture the behaviour of the NoC and the applications using a dataflow model. This enables one to verify the temporal behaviour and to compute buffer sizes using existing dataflow analysis techniques. The authors show what is required from the NoC architecture and demonstrate how to construct an NoC model, with multiple levels of detail. Using the proposed model, buffer sizes are determined for a range of SoC designs with a run time comparable to existing analytical methods, and results comparable to exhaustive simulation. For an application case study, where existing buffer-sizing methods are not applicable, the proposed model enables the verification of end-to-end temporal behaviour

Algebra of Observables for Identical Particles in One Dimension

The algebra of observables for identical particles on a line is formulated starting from postulated basic commutation relations. A realization of this algebra in the Calogero model was previously known. New realizations are presented here in terms of differentiation operators and in terms of SU(N)-invariant observables of the Hermitian matrix models. Some particular structure properties of the algebra are briefly discussed.Comment: 13 pages, Latex, uses epsf, 1 eps figure include

Animal welfare efforts and farm economic outcomes: Evidence from Swedish beef production

We estimate the relationship between farm animal welfare (FAW) efforts taken by beef farmers and the economic performance of beef farms by using farm accounting data from the Swedish Farm Economic Survey matched with survey data on farm management practices. To this end, we perform a two-step analysis. First, an item response theory (IRT) model estimates the latent FAW effort on farms. FAW effort likely depends on a host of complementary FAW-improving strategies, and the IRT model combines the considered strategies into a unidimensional scale. We take this to represent on-farm FAW effort. Second, we use instrumental variable regressions to estimate the relationship between FAW effort and multiple measures of farm economic performance. We find that higher FAW effort scores have no effect on margins and costs. However, higher FAW effort scores are associated with lower farm sales. Findings suggest that policies (such as targeted label for high FAW) that increase farm revenue as well as incentivize the uptake of FAW-improvement practices may be able to compensate farmers for their FAW effort

Configuring the Ubiquitous Home

Abstract. This paper presents the development of a lightweight component model that allows user to manage the introduction and arrangement of new interactive services and devices in the home. Interaction techniques developed through userparticipation enable household members – rather than designers – to configure an