Targeting a silent disease: vascular calcification in chronic Kidney disease

Chronic kidney disease (CKD) patients have a higher risk of developing early cardiovascular disease (CVD). Although vascular calcification (VC) is one of the strongest predictors of CVD risk, its diagnosis among the CKD population remains a serious clinical challenge. This is mainly due to the complexity of VC, which results from various interconnected pathological mechanisms occurring at early stages and at multiples sites, affecting the medial and intimal layers of the vascular tree. Here, we review the most used and recently developed imaging techniques, here referred to as imaging biomarkers, for VC detection and monitoring, while discussing their strengths and limitations considering the specificities of VC in a CKD context. Although imaging biomarkers have a crucial role in the diagnosis of VC, with important insights into CVD risk, circulating biomarkers represent an added value by reflecting the molecular dynamics and mechanisms involved in VC pathophysiological pathways, opening new avenues into the early detection and targeted interventions. We propose that a combined strategy using imaging and circulating biomarkers with a role in multiple VC molecular mechanisms, such as Fetuin-A, Matrix Gla protein, Gla-rich protein and calciprotein particles, should represent high prognostic value for management of CVD risk in the CKD population.info:eu-repo/semantics/publishedVersio

Strategies for tutoring written expression in students with ADHD and learning difficulties

ADHD and learning difficulties are associated with limitations in working memory capacity which may disrupt performance of writing skills. This thesis investigated teaching strategies to improve story-writing skills in five students with ADHD and learning difficulties in writing. The strategies were based on the view that these students would write more effectively if the task imposed fewer constraints on working memory capacity (the ability to store information while performing a task). Students were taught to write stories under time constraints using the PW2R approach of five minutes to plan, five to draft and five to review. Students planned orally during the first few weeks, then learned to plan by writing their ideas into a web diagram. Students finally learned to plan by using teacher-prescribed headings denoting conventional story structure. The 12 story elements were written into a wheel shaped diagram, forming the prompt for students\u27 ideas on the set topic. Specific gains were linked to the introduction of two spatial planning strategies. Four students wrote longer stories containing more ideas when using the self-generated web strategy, and four students wrote stories containing more story elements using the wheel strategy which incorporated story elements. Two students maintained gains regardless of strategy use, and two maintained gains only when using the written planning strategy. It appears that individual differences should be taken into account in instruction and task design, and that task modification can help to improve the quantity and quality of writing. Results showed that students improved written expression skills after less than 15 hours of instruction, distributed across a 20-week period. Overall progress may be linked to teaching factors held constant, such as simplifying the writing task into component sub-tasks, individualising instruction and providing graduated prompts, facilitating accurate, guided and independent practice, and providing specific feedback

Toll competition in highway transportation networks

Within a highway transportation network, the social welfare implications of two different groups of agents setting tolls in competition for revenues are studied. The first group comprises private sector toll road operators aiming to maximise revenues. The second group comprises local governments or jurisdictions who may engage in tax exporting. Extending insights from the public economics literature, jurisdictions tax export because when setting tolls to maximise welfare for their electorate, they simultaneously benefit from revenues from extra-jurisdictional users. Hence the tolls levied by both groups will be higher than those intended solely to internalise congestion, which then results in welfare losses. Therefore the overarching question investigated is the extent of welfare losses stemming from such competition for toll revenues. While these groups of agents are separately studied, the interactions between agents in each group in competition can be modelled within the common framework of Equilibrium Problems with Equilibrium Constraints. Several solution algorithms, adapting methodologies from microeconomics as well as evolutionary computation, are proposed to identify Nash Equilibrium toll levels. These are demonstrated on realistic transportation networks. As an alternative paradigm to competition, the possibilities for co-operation between agents in each group are also explored. In the case of toll road operators, the welfare consequences of competition could be positive or adverse depending on the interrelationships between the toll roads in competition. The results therefore generalise those previously obtained to a more realistic setting investigated here. In the case of competition between jurisdictions, it is shown that the fiscal externality of tax exporting resulting from their toll setting decisions can substantially reduce the welfare gains from internalising congestion. The ability of regulation, co-operation and bilateral bargaining to reduce the welfare losses are assessed. The research thus contributes to informing debates regarding the appropriate level of institutional governance for toll pricing policies