Player agency in interactive narrative: audience, actor & author

The question motivating this review paper is, how can computer-based interactive narrative be used as a constructivist learn- ing activity? The paper proposes that player agency can be used to link interactive narrative to learner agency in constructivist theory, and to classify approaches to interactive narrative. The traditional question driving research in interactive narrative is, ‘how can an in- teractive narrative deal with a high degree of player agency, while maintaining a coherent and well-formed narrative?’ This question derives from an Aristotelian approach to interactive narrative that, as the question shows, is inherently antagonistic to player agency. Within this approach, player agency must be restricted and manip- ulated to maintain the narrative. Two alternative approaches based on Brecht’s Epic Theatre and Boal’s Theatre of the Oppressed are reviewed. If a Boalian approach to interactive narrative is taken the conflict between narrative and player agency dissolves. The question that emerges from this approach is quite different from the traditional question above, and presents a more useful approach to applying in- teractive narrative as a constructivist learning activity

Solving the Poisson equation on small aspect ratio domains using unstructured meshes

We discuss the ill conditioning of the matrix for the discretised Poisson equation in the small aspect ratio limit, and motivate this problem in the context of nonhydrostatic ocean modelling. Efficient iterative solvers for the Poisson equation in small aspect ratio domains are crucial for the successful development of nonhydrostatic ocean models on unstructured meshes. We introduce a new multigrid preconditioner for the Poisson problem which can be used with finite element discretisations on general unstructured meshes; this preconditioner is motivated by the fact that the Poisson problem has a condition number which is independent of aspect ratio when Dirichlet boundary conditions are imposed on the top surface of the domain. This leads to the first level in an algebraic multigrid solver (which can be extended by further conventional algebraic multigrid stages), and an additive smoother. We illustrate the method with numerical tests on unstructured meshes, which show that the preconditioner makes a dramatic improvement on a more standard multigrid preconditioner approach, and also show that the additive smoother produces better results than standard SOR smoothing. This new solver method makes it feasible to run nonhydrostatic unstructured mesh ocean models in small aspect ratio domains.Comment: submitted to Ocean Modellin

Anemia in Antiretroviral Naïve HIV/AIDS Patients: A Study from Eastern India

Background: Hematological manifestations are common throughout the course of HIV infection. Impact of anemia is the most significant among them. The present study was undertaken to evaluate the etiologies underlying anemia in HIV/AIDS. Methods This was a non randomized cross sectional observational study conducted in a tertiary care hospital of India over a period of 2 years. One hundred and fifty HIV patients were screened. Thorough clinical and laboratory evaluation was done in 50 randomly selected anemic cases. Results: Proper etiological diagnosis could be reached in 46 patients. Among them correlation between Hb% and CD4 count was statistically insignificant (p = 0.074, r = 0.47) whereas it was significant with absolute lymphocyte and CD4 count (p = 0.006, r = 0.41). There was better correlation of bone marrow iron status with percent saturation of transferrin (p = 0.003, r = 0.54) than with serum ferritin (p = 0.055, r = 0.09). Bone marrow iron status did not have any relationship with CD4 count. Anemia of chronic disease was the commonest etiology (37%) followed by HIV related myelodysplastic syndrome (31%), iron deficiency anemia (13%), bone marrow suppression due to direct involvement by some infective process (7%). Aplastic anemia, multiple myeloma, Hodgkin’s disease, pure red cell aplasia, hemophagocytic lymphohistiocytosis and vitamin B12 deficiency were detected in one case (2%) each. Conclusions: Etiologies of anemia in HIV/AIDS are multifactorial with anemia of chronic disease being the commonest. For screening of iron deficiency in this group, percent saturation is a better tool than serum ferritin. Absolute lymphocyte count can sometimes be used as a surrogate marker of immunological status in antiretroviral naïve HIV patients, particularly in resource poor areas

Teleosemantics and the hard problem of content

Hutto and Myin claim that teleosemantics cannot account for mental content. In their view, teleosemantics accounts for a poorer kind of relation between cognitive states and the world but lacks the theoretical tools to account for a richer kind. We show that their objection imposes two criteria on theories of content: a truth-evaluable criterion and an intensionality criterion. For the objection to go through, teleosemantics must be subject to both these criteria and must fail to satisfy them. We argue that teleosemantics meets the truth-evaluable criterion and is not required to meet the intensionality criterion. We conclude that Hutto and Myin’s objection fails

Teleosemantics and the free energy principle

The free energy principle is notoriously difficult to understand. In this paper, we relate the principle to a framework that philosophers of biology are familiar with: Ruth Millikan’s teleosemantics. We argue that: (i) systems that minimise free energy are systems with a proper function; and (ii) Karl Friston’s notion of implicit modelling can be understood in terms of Millikan’s notion of mapping relations. Our analysis reveals some surprising formal similarities between the two frameworks, and suggests interesting lines of future research. We hope this will aid further philosophical evaluation of the free energy principle

Chicken Embryonic-Stem Cells Are Permissive to Poxvirus Recombinant Vaccine Vectors.

The discovery of mammalian pluripotent embryonic stem cells (ESC) has revolutionised cell research and regenerative medicine. More recently discovered chicken ESC (cESC), though less intensively studied, are increasingly popular as vaccine substrates due to a dearth of avian cell lines. Information on the comparative performance of cESC with common vaccine viruses is limited. Using RNA-sequencing, we compared cESC transcriptional programmes elicited by stimulation with chicken type I interferon or infection with vaccine viruses routinely propagated in primary chicken embryo fibroblasts (CEF). We used poxviruses (fowlpox virus (FWPV) FP9, canarypox virus (CNPV), and modified vaccinia virus Ankara (MVA)) and a birnavirus (infectious bursal disease virus (IBDV) PBG98). Interferon-stimulated genes (ISGs) were induced in cESC to levels comparable to those in CEF and immortalised chicken fibroblast DF-1 cells. cESC are permissive (with distinct host transcriptional responses) to MVA, FP9, and CNPV but, surprisingly, not to PBG98. MVA, CNPV, and FP9 suppressed innate immune responses, while PBG98 induced a subset of ISGs. Dysregulation of signalling pathways (i.e., NFκB, TRAF) was observed, which might affect immune responses and viral replication. In conclusion, we show that cESC are an attractive alternative substrate to study and propagate poxvirus recombinant vaccine vectors

Self-consistent modelling of hot plasmas within non-extensive Tsallis' thermostatistics

A study of the effects of non-extensivity on the modelling of atomic physics in hot dense plasmas is proposed within Tsallis' statistics. The electronic structure of the plasma is calculated through an average-atom model based on the minimization of the non-extensive free energy.Comment: submitted to "Eur. Phys. J. D