In Search of Resonance

In this paper I explore the possibility of a complementary relationship between action research and the management and systems sciences. A range of purposes that action researchers and management and systems scientists pursue is initially set out. The paper then explores whether this diversity of purposes and the ways they recommend people to proceed may come together in a new whole that is greater than the sum of its parts. A potentially useful realization of this for practice is a reflexive process of critique, choice, and action, which is elaborated on. The paper then investigates what view of holism arises from the preceeding discussions.     

Editorial

Systemic Practice and Action Research -     

Editorial

Systemic Practice and Action Research -     

Editorial

Systemic Practice and Action Research -     

Editorial

Systemic Practice and Action Research -     

Classification and Categorical Inputs with Treed Gaussian Process Models

Recognizing the successes of treed Gaussian process (TGP) models as an interpretable and thrifty model for nonparametric regression, we seek to extend the model to classification. Both treed models and Gaussian processes (GPs) have, separately, enjoyed great success in application to classification problems. An example of the former is Bayesian CART. In the latter, real-valued GP output may be utilized for classification via latent variables, which provide classification rules by means of a softmax function. We formulate a Bayesian model averaging scheme to combine these two models and describe a Monte Carlo method for sampling from the full posterior distribution with joint proposals for the tree topology and the GP parameters corresponding to latent variables at the leaves. We concentrate on efficient sampling of the latent variables, which is important to obtain good mixing in the expanded parameter space. The tree structure is particularly helpful for this task and also for developing an efficient scheme for handling categorical predictors, which commonly arise in classification problems. Our proposed classification TGP (CTGP) methodology is illustrated on a collection of synthetic and real data sets. We assess performance relative to existing methods and thereby show how CTGP is highly flexible, offers tractable inference, produces rules that are easy to interpret, and performs well out of sample.     

Displacing Epistemology: Being in the Midst of Technoscientific Practice

Interest the Erklären?CVerstehen debate is usually interpreted as primarily epistemological. By raising the possibility that there are fundamentally different methods for fundamentally different types of science, the debate puts into play all the standard issues??that is, issues concerning scientific explanation and justification, the unity and diversity of scientific disciplines, the reality of their subject matter, the accessibility of various subject matters to research, and so on. In this paper, however, I do not focus on any of these specific issues. I start instead from the fact that the very existence of the debate itself is an issue; in fact, it poses a philosophical problem that almost everyone but the hardest line logical empiricists has come to realize cannot be resolved epistemologically. In my view, however, that it cannot be resolved ontologically, either. I think the problem is at bottom hermeneutical, and its resolution requires that we focus first, not on the objects of science or the methods of studying them, but on the character of the philosophical orientation assumed by those who would try to resolve it. In this paper, I explain why I think this is so by analyzing (1) Dilthey??s contribution to the original debate, (2) Husserl??s reaction to Dilthey, and (3) Heidegger??s critical evaluation of both. This line of philosophical development??this movement of self-understanding from critiques of objectivism to hermeneutical phenomenology??is of course already a central feature of much work in continental philosophy of science. In my conclusion, however, I argue for the less well-established??even if apparently approved??idea that it ought to be a central feature of technoscience studies as well.     

ANG mutations segregate with familial and 'sporadic' amyotrophic lateral sclerosis

We recently identified angiogenin (ANG) as a candidate susceptibility gene for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder characterized by adult-onset loss of motor neurons. We now report the finding of seven missense mutations in 15 individuals, of whom four had familial ALS and 11 apparently 'sporadic' ALS. Our findings provide further evidence that variations in hypoxia-inducible genes have an important role in motor neuron degeneration.     

Trak1 mutation disrupts GABA(A) receptor homeostasis in hypertonic mice

Hypertonia, which results from motor pathway defects in the central nervous system (CNS), is observed in numerous neurological conditions, including cerebral palsy, stroke, spinal cord injury, stiff-person syndrome, spastic paraplegia, dystonia and Parkinson disease. Mice with mutation in the hypertonic (hyrt) gene exhibit severe hypertonia as their primary symptom. Here we show that hyrt mutant mice have much lower levels of gamma-aminobutyric acid type A (GABA(A)) receptors in their CNS, particularly the lower motor neurons, than do wild-type mice, indicating that the hypertonicity of the mutants is likely to be caused by deficits in GABA-mediated motor neuron inhibition. We cloned the responsible gene, trafficking protein, kinesin binding 1 (Trak1), and showed that its protein product interacts with GABA(A) receptors. Our data implicate Trak1 as a crucial regulator of GABA(A) receptor homeostasis and underscore the importance of hyrt mice as a model for studying the molecular etiology of hypertonia associated with human neurological diseases.