Approximation Complexity of Maximum A Posteriori Inference in Sum-Product Networks

We discuss the computational complexity of approximating maximum a posteriori inference in sum-product networks. We first show NP-hardness in trees of height two by a reduction from maximum independent set; this implies non-approximability within a sublinear factor. We show that this is a tight bound, as we can find an approximation within a linear factor in networks of height two. We then show that, in trees of height three, it is NP-hard to approximate the problem within a factor $2^{f(n)}$ for any sublinear function $f$ of the size of the input $n$. Again, this bound is tight, as we prove that the usual max-product algorithm finds (in any network) approximations within factor $2^{c \cdot n}$ for some constant $c < 1$. Last, we present a simple algorithm, and show that it provably produces solutions at least as good as, and potentially much better than, the max-product algorithm. We empirically analyze the proposed algorithm against max-product using synthetic and realistic networks.Comment: 18 page

Foundations for the Social Economy

At present the strategies, policies and tools employed by the social economy in most countries are diffuse. There is no integrated narrative to bring together the small parts to form a more cohesive whole. This cross-cutting project, led by Mike Lewis and Pat Conaty, is intended to review the scope and success of emergent systemic approaches in order to explore the implications for developing a new social and ecological economy at the sub-regional level. The investigation will produce a new conceptual framework for understanding the foundations for a more strategic approach by social economy actors. In the wake of the credit crunch and developing recession, the project will appraise social economy needs including equitable access to land & premises, patient capital and enabling legal structures.BC-Alberta Social Economy Research Alliance (BALTA

Den stora omställningen: en seglats genom en turbulent tids sociala, ekonomiska och ekologiska förändringar

This paper was presented at the 1-2 October, 2009 Conference of the Centre International de Recherches et d'Information sur l'Economie Publique, Sociale et Coopérative (CIRIEC) in Östersund, Sweden. The paper was translated into Swedish for use at a number of presentations in Sweden immediately preceding and after the CIRIEC conference.Swedish translation of an original paper in English. Trans-disciplinary thinking by evolutionary, social, and ecological economists from the mid-1970s pointed to a new paradigm from which working models are emerging. This paper illustrates their relevance to a context where the vulnerability of communities to the intertwined issues of carbon, energy, food, finance, and disparity is mounting. The strategic role of co-operative, complementary innovation in navigating these challenges is elaborated.BC-Alberta Social Economy Research Alliance (BALTA) ; Social Sciences and Humanities Research Council of Canada (SSHRC

The Great Transition: Navigating Social, Economic, Ecological Change in Turbulent Times

This paper was presented at the 1-2 October, 2009 Conference of the Centre International de Recherches et d'Information sur l'Economie Publique, Sociale et Coopérative (CIRIEC) in Östersund, Sweden.Trans-disciplinary thinking by evolutionary, social, and ecological economists from the mid-1970s pointed to a new paradigm from which working models are emerging. This paper illustrates their relevance to a context where the vulnerability of communities to the intertwined issues of carbon, energy, food, finance, and disparity is mounting. The strategic role of co-operative, complementary innovation in navigating these challenges is elaborated.BC-Alberta Social Economy Research Alliance (BALTA) ; Social Sciences and Humanities Research Council of Canada (SSHRC

La Gran Transición: Navegando por un Cambio Social, Económico y Ecológico en Tiempos Turbulentos

This paper was presented at the 1-2 October, 2009 Conference of the Centre International de Recherches et d'Information sur l'Economie Publique, Sociale et Coopérative (CIRIEC) in Östersund, Sweden. It was subsequently translated into Spanish.Spanish translation of an original paper in English. Trans-disciplinary thinking by evolutionary, social, and ecological economists from the mid-1970s pointed to a new paradigm from which working models are emerging. This paper illustrates their relevance to a context where the vulnerability of communities to the intertwined issues of carbon, energy, food, finance, and disparity is mounting. The strategic role of co-operative, complementary innovation in navigating these challenges is elaborated.BC-Alberta Social Economy Research Alliance (BALTA) ; Social Sciences and Humanities Research Council of Canada (SSHRC

La grande transition : maintenir le cap sur le changement social, économique et écologique en périodes de turbulence

This paper was presented at the 1-2 October, 2009 Conference of the Centre International de Recherches et d'Information sur l'Economie Publique, Sociale et Coopérative (CIRIEC) in Östersund, Sweden. The paper was subsequently translated into French.French translation of an original paper in English. Trans-disciplinary thinking by evolutionary, social, and ecological economists from the mid-1970s pointed to a new paradigm from which working models are emerging. This paper illustrates their relevance to a context where the vulnerability of communities to the intertwined issues of carbon, energy, food, finance, and disparity is mounting. The strategic role of co-operative, complementary innovation in navigating these challenges is elaborated.BC-Alberta Social Economy Research Alliance (BALTA) ; Social Sciences and Humanities Research Council of Canada (SSHRC

A Critical Analysis of Michael Shermer’s: Can We Be Good Without God?

This critique of a chapter in Michael Shermer’s The Science of Good and Evil analyzes the rhetoric behind his argument that morality is possible without belief in God. It examines Shermer’s language, tone toward opposing views, and the ethical implications of his approach

Influenza vaccination during pregnancy: A qualitative study of the knowledge, attitudes, beliefs, and practices of general practitioners in Central and South-Western Sydney

Background: Pregnant women have an increased risk of influenza complications. Influenza vaccination during pregnancy is safe and effective, however coverage in Australia is less than 40%. Pregnant women who receive a recommendation for influenza vaccination from a health care provider are more likely to receive it, however the perspectives of Australian general practitioners has not previously been reported. The aim of the study was to investigate the knowledge, attitudes, beliefs, and practices of general practitioners practicing in South-Western Sydney, Australia towards influenza vaccination during pregnancy. Methods. A qualitative descriptive study was conducted, with semi-structured interviews completed with seventeen general practitioners in October 2012. A thematic analysis was undertaken by four researchers, and transcripts were analysed using N-Vivo software according to agreed codes. Results: One-third of the general practitioners interviewed did not consider influenza during pregnancy to be a serious risk for the mother or the baby. The majority of the general practitioners were aware of the government recommendations for influenza vaccination during pregnancy, but few general practitioners were confident of their knowledge about the vaccine and most felt they needed more information. More than half the general practitioners had significant concerns about the safety of influenza vaccination during pregnancy. Their practices in the provision of the vaccine were related to their perception of risk of influenza during pregnancy and their confidence about the safety of the vaccine. While two-thirds reported that they are recommending influenza vaccination to their pregnant patients, many were adopting principles of patient-informed choice in their approach and encouraged women to decide for themselves whether they would receive the vaccine. Conclusions: General practitioners have varied knowledge, attitudes, and beliefs about influenza vaccination during pregnancy, which influence their practices. Addressing these could have a significant impact on improving vaccine uptake during pregnancy. © 2014 Maher et al.; licensee BioMed Central Ltd