Empiricist Interventions:Strategy and Tactics on the Ontopolitical Battlefield

Recent papers by prominent scholars in science and technology studies (notably John Law and Bruno Latour) have crystallized a fundamental disagreement about the scope and purpose of intervention in actor-network theory or what we here choose to bracket as empirical philosophy. While the precept of agnostic description is taken as a given, the desired effects of such descriptions are highly debated: Is the goal to interfere with the singularity of the real through the enactment of multiple and possibly conflicting ontologies? Or is it (also) to craft new and comprehensive common worlds supported by notions of due process and parliamentary procedure? In this paper we think about this disagreement as a question of research strategy (a normative discord about the desirable outcome of an intervention) in order to assess its implications for research tactics (a descriptive accord about the practical crafting of an adequate account). A key point here is to challenge the impermeability of such a division and show how the strategic dispute, if to be taken seriously, invariably spills over to swamp the level of tactics. To illustrate this point, we draw upon materials from our recent doctoral research projects and to facilitate the discussion we make two deliberate caricatures: Firstly, we operate with a simplified history of actor-network theory in which a strategy of epistemological critique has been replaced by two contending agendas for ontological intervention. Secondly, we address these two contending agendas as distinct options which map on to the positions of our two main interlocutors. In doing so, it becomes possible to compare their respective tactical implications as we work through two examples of what might constitute an empiricist intervention

The Metacognition in Self-Control Scale (MISCS)

Metacognition is a well-researched construct important to successful learning. Recent studies show that state-level metacognition regarding self-control conflicts is also important for successfully resolving these conflicts. Because there exists no scale to assess trait-level metacognition in self-control and because of limitations of commonly used measures in self-control research, we adapted a scale that is widely used to assess trait-level metacognition in self-regulated learning, the Metacognitive Awareness Inventory (MAI). In two studies (N = 315 and N = 503), we constructed the 12-item Metacognition in Self-Control Scale (MISCS), which loaded on the two factors metacognitive knowledge and metacognitive regulation. The MISCS showed a good fit with good internal consistencies. In the 10-day experience sampling part of study 2, which included 9639 reports of self-control conflicts, higher trait-levels of metacognition as measured with the MISCS predicted higher state-levels of success in resolving these conflicts, as well as higher state-levels of the subcomponents of metacognition, namely metacognitive knowledge, planning, monitoring, and evaluation. Most of these associations persisted when controlling for trait self-control, supporting the usefulness of the scale beyond the most commonly used scale in self-control research. The MISCS showed adequate test-retest reliability. Correlations with other scales, limitations, and future directions are discussed

Frequency-adaptable tuned mass damper using metal cushions

A frequency-adaptable tuned mass damper (FATMD) using metal cushions as tuneable stiffness components is presented. The dynamic properties of the cushions with respect to stiffness and damping are investigated experimentally in this context. The natural frequency of the experimental FATMD is found to be dependent on the precompression of the metal cushions, which behave like nonlinear springs, yielding an adjustable frequency range from 67 to 826 Hz. As the precompression is increased, the stiffness increases while the damping characteristics decrease, the effect of which was quantified using a viscous mass damper model as a first approximation. Measurements have been carried out under five different excitation amplitudes to investigate the amplitude dependency of the resonance frequency. The FATMD was largely unaffected by changes in input amplitude. It was concluded that metal cushions show great potential for use in FATMDs, surpassing the utility of elastomers, especially with respect to their temperature stability

Reactive species driven oxidative modifications of peptides—Tracing physical plasma liquid chemistry

The effluence of physical plasma consists of a significant share of reactive species, which may interact with biomolecules and yield chemical modifications comparable to those of physiological processes, e.g., post-translational protein modifications (oxPTMs). Consequentially, the aim of this work is to understand the role of physical plasma-derived reactive species in the introduction of oxPTM-like modifications in proteins. An artificial peptide library consisting of ten peptides was screened against the impact of two plasma sources, the argon-driven MHz-jet kINPen and the helium-driven RF-jet COST-Jet. Changes in the peptide molecular structure were analyzed by liquid chromatography–mass spectrometry. The amino acids cysteine, methionine, tyrosine, and tryptophan were identified as major targets. The introduction of one, two, or three oxygen atoms was the most common modification observed. Distinct modification patterns were observed for nitration (+N + 2O–H), which occurred in kINPen only (peroxynitrite), and chlorination (+Cl–H) that was exclusive for the COST-Jet in the presence of chloride ions (atomic oxygen/hypochlorite). Predominantly for the kINPen, singlet oxygen-related modifications, e.g., cleavage of tryptophan, were observed. Oxidation, carbonylation, and double oxidations were attributed to the impact of hydroxyl radicals and atomic oxygen. Leading to a significant change in the peptide side chain, most of these oxPTM-like modifications affect the secondary structure of amino acid chains, and amino acid polarity/functionality, ultimately modifying the performance and stability of cellular proteins