A reversible infinite HMM using normalised random measures

We present a nonparametric prior over reversible Markov chains. We use completely random measures, specifically gamma processes, to construct a countably infinite graph with weighted edges. By enforcing symmetry to make the edges undirected we define a prior over random walks on graphs that results in a reversible Markov chain. The resulting prior over infinite transition matrices is closely related to the hierarchical Dirichlet process but enforces reversibility. A reinforcement scheme has recently been proposed with similar properties, but the de Finetti measure is not well characterised. We take the alternative approach of explicitly constructing the mixing measure, which allows more straightforward and efficient inference at the cost of no longer having a closed form predictive distribution. We use our process to construct a reversible infinite HMM which we apply to two real datasets, one from epigenomics and one ion channel recording.Comment: 9 pages, 6 figure

Assessing the Effect of Differential Diffusion for Stratified Lean Premixed Turbulent Flames with the Use of LES-PDF Framework

Lean premixed stratified combustion is rapidly growing in importance for modern engine designs. This paper presents large eddy simulations for a new burner design to assess the predictive capability of the probability density function (pdf) approach to flames that propagate through non-homogeneous mixtures in terms of equivalence ratio. Although various efforts have been made in the past for the simulation of the same test case the novelty of this work lies to the fact that it is the first simulation effort that differential diffusion is accounted for given the relatively low Reynolds numbers (13,800) of the configuration. First mean and root mean square velocity simulations are performed for the isothermal cases to assess the effect of the grid resolution and the overall LES flow field solver. Then instantaneous snapshots of the flame are presented to provide insight to the structure of the flame and the effect of stratification. Finally, results for velocities, temperature and mixture fraction are presented and compared with the experimental data. Overall, the results are in very good agreement with experiments

Growing functional modules from a seed protein via integration of protein interaction and gene expression data

<p>Abstract</p> <p>Background</p> <p>Nowadays modern biology aims at unravelling the strands of complex biological structures such as the protein-protein interaction (PPI) networks. A key concept in the organization of PPI networks is the existence of dense subnetworks (functional modules) in them. In recent approaches clustering algorithms were applied at these networks and the resulting subnetworks were evaluated by estimating the coverage of well-established protein complexes they contained. However, most of these algorithms elaborate on an unweighted graph structure which in turn fails to elevate those interactions that would contribute to the construction of biologically more valid and coherent functional modules.</p> <p>Results</p> <p>In the current study, we present a method that corroborates the integration of protein interaction and microarray data via the discovery of biologically valid functional modules. Initially the gene expression information is overlaid as weights onto the PPI network and the enriched PPI graph allows us to exploit its topological aspects, while simultaneously highlights enhanced functional association in specific pairs of proteins. Then we present an algorithm that unveils the functional modules of the weighted graph by expanding a kernel protein set, which originates from a given 'seed' protein used as starting-point.</p> <p>Conclusion</p> <p>The integrated data and the concept of our approach provide reliable functional modules. We give proofs based on yeast data that our method manages to give accurate results in terms both of structural coherency, as well as functional consistency.</p

Finite element analysis of fire resistant reinforcement on end-plate steel connections

In this paper the effect of fire resistant coatings on the mechanical behaviour of steel joints is studied using the finite element method. The proposed finite element model is an extension of a previous one developed for the study of the same connection in elevated temperatures, without fire reinforcement. In particular, the construction used consists of an end – plate steel connection which is covered with panels of lightweight concrete and gypsum board. The behaviour of those two fire resistant materials has been simulated in elevating mechanical and thermal conditions separately and simultaneously. Through this process it is examined the strength of the materials and of the overall construction. Specifically, the action of fire on the strength of the structure may result in an early collapse. In addition, the behaviour of the structure in the connection area and the opening of the interface is investigated

The participatory medicine attidutes of general practitioners in Greece: an information behaviour perspective.

In shared health decision-making, cooperation in the patient-doctor relationship is fundamental. However, lack of health literacy may act as a significant barrier in this process. Patients are expected to make decisions even though they are in an uneven position in terms of knowledge (Bernabeo & Holmboe, 2013; McMullan, 2006). In our research we examined the information seeking behaviour of doctors, their views on cooperation with their patients, and the role that information consultations play in shared decision-making. Our study involved a survey of 162 private general practitioners and private pathologists in Greece. We collected demographic characteristics and self-assessments of doctors using a five point Likert scale. We used the Kruskall-Wallis non-parametric test for the analysis of the relationship between demographics and the importance assigned to information consultations. Doctors reported that they used both electronic and interpersonal sources for diagnoses, treatment, and updating their knowledge. The barriers they experienced included lack of time, the cost of access, and the difficulty of finding information, confirming previous research in this area (Davies, 2011). Most doctors considered the cooperation of their patients as important for decision making (mean=3.69) and improving the overall clinical outcome (mean =4.19). Most agreed that they relied on patients to further developing their own information literacy (IL). Doctors expected their patients to consult health related publications they directed them to in the form of print materials (mean=3.59), medical Internet websites (mean=3.81), or the website/Facebook page of their general practice (mean=3.20). However, there was a statistically significant difference when age was factored in. More than half of the more experienced doctors (above 60 years old, 55,1%) did not share the same positive views on cooperation and did not direct their patients to different information sources. It was mostly the younger doctors who took advantage of the Internet as a health consultation tool. Doctors between 40-55 years (97%) directed their patients to articles published on medical websites, while using the website/Facebook page of the general practice was more prevalent in doctors younger than 40 years old (90%). This paper argues that doctors form the main information literacy (IL) pillar for patients as they are their first port of call for their healthcare decisions. But not all doctors are ready and willing to offer information prescriptions that will help advance their patients' IL empowerment to be able to identify and use quality health information independently for their evidence-based and informed decision-making. Title listed on conference website as The Value of Information Related Practices in Patient-Doctor Relationships