A Molecular Probe Finds Evidence of NIX Pathogen in Pacific Razor Clams (\u3cem\u3eSiliqua patula\u3c/em\u3e) in Oregon

The Pacific razor clam, Siliqua patula, is an important recreational fishery species that lives in the intertidal zone of sandy beaches from Alaska to central California. Populations have had periodic, but significant, declines over the past 30-40 years. These declines have correlated with an increase in the presences of an unidentified, intranuclear bacterial parasite known as Nuclear Inclusion X (NIX). NIX, which was first identified in 1986, has generally been screened using a histological approach. We developed a PCR-based screen to reduce both the time and cost of identifying infected clams. Use of this screen resulted in amplified sequences with a 97% match to the previously published 16S rDNA sequence for NIX. The sequence data supports placement of NIX into the gamma-proteobacteria, and suggests that it is related to isolates from diseased corals. Clams collected from the northern coast of Oregon showed ~50% infection rate using the PCR screen. This is the first report of NIX present in clams from Oregon, as all previous work had been in the state of Washington. Future work will identify the incidence rate and geographical spread of the NIX parasite throughout Oregon and Washington

Learning how to engage students online in hard times

In a context of financial restraint and enterprising university managers, teacher-researchers have reason to be sceptical about the trend towards online teaching and away from learning for its own sake. This article departs from both economic and technological determinism and turns instead to ideas about technology embedded in social and political institutions. Activity theory offers a useful means of analysing such embeddedness. Its Marxian assumptions about human nature specify a non-deterministic approach to technology. Its dynamic model of the subjects, tools, and objects of activity within a context of rules, a community, and a division of labour helps to specify aspects of the authors process of learning how to use electronic conferencing effectively. A full deployment of activity theory would also analyse the activity of students. Here the evidence comes mainly from the activity of researcher-teachers engaging greater activity among students. The numbers of students involved precludes reliable quantitative analysis but qualitative evidence from students does support conclusions about researcher-teachers learning how to make best use of electronic conferencing.<br /

Bayesian Inference on Matrix Manifolds for Linear Dimensionality Reduction

We reframe linear dimensionality reduction as a problem of Bayesian inference on matrix manifolds. This natural paradigm extends the Bayesian framework to dimensionality reduction tasks in higher dimensions with simpler models at greater speeds. Here an orthogonal basis is treated as a single point on a manifold and is associated with a linear subspace on which observations vary maximally. Throughout this paper, we employ the Grassmann and Stiefel manifolds for various dimensionality reduction problems, explore the connection between the two manifolds, and use Hybrid Monte Carlo for posterior sampling on the Grassmannian for the first time. We delineate in which situations either manifold should be considered. Further, matrix manifold models are used to yield scientific insight in the context of cognitive neuroscience, and we conclude that our methods are suitable for basic inference as well as accurate prediction.Comment: All datasets and computer programs are publicly available at http://www.ics.uci.edu/~babaks/Site/Codes.htm

Social-movement unionism in theory and in Sweden

Many union leaders and observers of unionism in industrially advanced countries have recently argued for stronger links between unions and social movements but their arguments leave the nature of social movements underspecified. This article reviews the literature on social movements and argues in favour of a minimalist theory of the social actor rather than choose between American and European approaches to studying social movements. Both Melucci\u27s European approach and McAdam, Tarrow, and Tilly\u27s American approach to integrating the European and American schools of thought on social movements are inadequate to the task of specifying social-movement unionism. Hindess\u27s minimalist theory of the social actor and articulated arenas of conflict offers a stronger approach to understanding social-movement unionism and appreciating its strategic pertinence in particular times and places. Two episodes of contention in Sweden illustrate the advantages of a minimalist theory of articulated social-movement unionism.<br /

Social movement unionism and networked technology

From a European perspective, the wide-ranging social, economic, and political effects of networked computers have generated tensions between \u27new\u27 social movements and the \u27old\u27 labour movement. From an American perspective on social movements, there is no such tension between old and new social movements. A study of social-movement unionism in Sweden offers a interesting means of testing this emerging American perspective against the European perspective because the labour movement has long been particularly effective and networked technology has been embraced whole-heartedly throughout all aspects of the society, the economy, and the polity. The paper introduces the contrasting European and American perspectives on social movements and presents examples of the practice of social-movement unionism among Swedish social democrats, unionists, and diverse local activists. These examples support conclusions that eschew utopian theories of \u27cyberunionism\u27 in favour of developing a theory of articulated unionism in which local unions branches articulate vertically with national and global union bodies, and articulate horizontally with social movements in other arenas of conflict.<br /