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Characterization and transcriptome analysis of mercury-resistant <i>Pseudomonas canadensis </i>isolated from a chlor-alkali contaminated soil revealed <i>mer</i>-independent detoxification pathways
No full textHuman activities have caused severe soil pollution through the discharge of pollutants, reshaping microbial communities. Among soil microbiota, the genus Pseudomonas exhibited remarkable tolerance to multiple contaminants, including mercury (Hg). This study compared the Hg resistance mechanisms of two Pseudomonas canadensis strains isolated from contrasting environments: a resistant isolate from the rhizosphere of Hg-contaminated soil and a control strain from unpolluted soil. The strain originating from a Hg-enriched soil showed significant biovolatilisation capacity and 20-fold higher Hg resistance compared to the strain isolated from an unpolluted environment. Biomass and necromass responses indicated that the control strain primarily relied on passive resistance, while the resistant strain exhibited active detoxification. Transcriptomic analysis revealed a rapid upregulation of genes associated with metal detoxification and efflux pathways in the resistant strain, independently of the mer operon, suggesting alternative resistance mechanisms. In contrast, the control strain exhibited transcriptional signatures of cellular stress, with increased thiol metabolism, DNA repair, and oxidative stress responses. These findings demonstrate that long-term Hg exposure selects for functional adaptations that sustain resistance in microbial populations. This work sheds new lights on Hg tolerance in P. canadensis and highlights the potential of naturally adapted strains for bioremediation strategies.</p
Work to Be Done:An Inquiry Concerning Legal Certainty in the Fourth Evaluation of the Dutch Euthanasia Act
No full textLegal certainty – that is predictability of law – is not just a legal principle but also an empirical topic. And as an empirical topic legal certainty can both be a goal and a means to achieve ends (‘factual legal certainty’). As concerns the Termination of Life on Request and Assisted Suicide (Review Procedures) Act, these ends involve next to legal certainty, to promote social transparency and to guarantee the carefulness of ending life on request. In this article, it is argued that legal certainty has not been properly examined in the fourth evaluation of the Act. Therefore, the results that are offered by the evaluation cannot support the conclusion that the goal of legal certainty has been achieved. The article proposes to operationalize factual legal certainty as knowledge of the rules and being able to predict how the relevant government agencies will act. Such an operationalization of legal certainty has been used before (Marseille 1993). A comparison between Marseille’s findings regarding legal certainty and what is known in this respect about euthanasia supposes that legal certainty regarding euthanasia law is to be expected. The conclusion is that an examination of legal certainty is possible ánd required.</p
Haptic Shared Control of a Pair of Microrobots for Telemanipulation using Constrained Optimization
No full textMicrorobotics implies actuation-related constraints that make safe telemanipulation particularly challenging. We present a haptic shared control system for electromagnetic-based telemanipulation of a pair of microrobots using a constrained optimization framework. Our contributions include: (1) a Quadratic Programming formulation with Control Lyapunov Functions and Control Barrier Functions, for safe and stable navigation in cluttered environments; (2) a shared control architecture, combining a haptic interface and simulation environment, to teleoperate the microrobots and enable micromanipulation capabilities; and (3) haptic shared control strategies offering visuo-haptic cues for task execution. The approach is validated through a user study, highlighting better navigation accuracy, control stability and task efficiency.</p
Tracking the truth by selecting good data:Coherence measures and data selection
No full textIn formal epistemology, a variety of probability-based coherence measures have been proposed that provide a quantitative formal representation of the coherence of a set of information pieces. While research has long focused on whether coherence measures are truth-conducive, the truth-conduciveness of coherence measures has so far been evaluated in static settings only: Coherence provides assessments about the truth of incoming information, but does not actively guide decisions to believe or discard pieces of information. In this paper, we propose to assess the truth-conduciveness of coherence measures with respect to their ability to lead agents to select true information and form correct beliefs in a dynamic iterative setting. At every time step, an agent receives a number of noisy signals about the actual truth values of a finite set of atomic propositional variables. The agent uses a coherence measure to decide which signals to trust and which to discard. By repeatedly picking signals that maximise the coherence of the propositions they currently believe to be true, the agent tries to select truthful signals and learn the correct truth-value assignment for the atomic variables. The contribution of this paper is three-fold. First, we propose a computational model to assess the truth-tracking abilities of different coherence measures. Second, using computational simulations, we compare a number of widely discussed coherence measures from the novel standpoint of our iterated data-collection setting: We show that, when signals are not too noisy, agents who employ the Glass-Olsson relative overlap measure outperform agents employing all other tested measures, and that all measures become progressively worse at leading agents towards the truth as signals degrade. Finally, we discuss how coherence affects the emergence of different dynamics and attitudes in belief revision.</p
