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Movement trajectories reflect active information acquisition by an echolocating porpoise in a target discrimination task
No full textVoluntary movements of echolocating animals with respect to targets in natural foraging or laboratory target discrimination tasks have long been interpreted as a closed-loop sensorimotor feedback driven by information in previously received echoes. However, what can we infer about sensorimotor integration and auditory information-gathering from animal movement trajectories? In this work, we use unsupervised clustering to analyze the movement trajectories of a free-swimming, echolocating harbor porpoise trained to select a sphere against prolate spheroids of varying aspect ratios presented at different angles, and show that the animal's discrimination performance and overall trajectory can be explained by task difficulty based on the similarity of target echo spectra received during its initial approach. The porpoise continued to evaluate its target selection via incoming echoes throughout the trials, and reversed its decision at very close ranges in a subset of trials. In more challenging scenarios, the animal engaged in prolonged, focused ensonification of a single target, sometimes via buzzes, which we interpret as an evidence accumulation process toward decision making. Our findings highlight movement, in addition to acoustic emissions, as a key behavioral readout in the active information acquisition process embodied in echolocation.</p
Synergistic cross-coupling catalysis:a trialkylphosphine/Pd catalyst tethered to MOF-808(Hf) is very effective for Suzuki-Miyaura coupling of problematic nucleophiles
No full textHafnium and zirconium forms of the benzene-1,3,5-tricarboxylate metal organic framework MOF-808 were prepared from aqueous solution and modified post-synthetically with 3-{(4-methoxy-phenyl)thio}propane-1-sulfonate (MPTPS) and 3-(di-tert-butylphosphino)propane-1-sulfonate (DTBPPS). Their ligands were stoichiometrically loaded with Pd2+. Pd@DTBPPS-MOF-808 is found to be a good catalyst for the Suzuki–Miyaura coupling of functionalised aryl boronic acid derivatives with aryl bromides and unactivated aryl chlorides and the MOF-808(Hf)-based catalysts show significant promise for some highly demanding cross-coupling combinations featuring electron deficient nucleophiles that suffer from poor transmetalation and significant protodeborylation. Remarkably, these led to strongly improved conversions over those based on MOF-808(Zr)
Planktonic foraminifera regulate calcification according to ocean density
No full textPlanktonic foraminifera are key contributors to the oceanic carbon cycle. In pelagic environments, carbonate production by planktonic biomineralizers regulates ocean-atmosphere carbon dioxide exchange and exports surface carbon to the deep ocean. Here we compare shell traits of three planktonic foraminifera species from the central Atlantic with a suite of environmental parameters to discern the factors underlying their variations. Our analysis revealed that calcification in foraminifera is associated with seawater density and depends on species habitat depth, whereas foraminifera bulk shell densities may serve as a seawater density proxy, regardless of species. We observe that their shell weights increased with habitat depth, enabling the living cells to adjust their overall density to match that of the surrounding liquid. This suggests that calcification in nonmotile organisms has a buoyancy regulatory function and will respond to the anthropogenically driven reductions in ocean density (oceanic rarefication), with potential consequences for the carbon cycle
Substrate pre-sputtering for layer-by-layer van der Waals epitaxy of 2D materials
No full textTwo-dimensional transition metal chalcogenides, with their atomically layered structure, favorable electronic and mechanical properties, and often strong spin–orbit coupling, are ideal systems for fundamental studies and for applications ranging from spintronics to optoelectronics. Their bottom–up synthesis via epitaxial techniques such as molecular-beam epitaxy (MBE) has, however, proved challenging. Here, we develop a simple substrate pre-treatment process utilizing exposure to a low-energy noble gas plasma. We show how this dramatically enhances nucleation of an MBE-grown epilayer atop, and through this, realize a true layer-by-layer growth mode. We further demonstrate the possibility of tuning the resulting growth dynamics via control of the species and dose of the plasma exposure
Youth unleashed:museums as platforms for heritage and climate dialogue
No full textAs the climate emergency intensifies, youth-led movements worldwide are pressuring governments and societies to take urgent climate action. However, young people from communities disproportionately impacted by the climate emergency, such as the Caribbean, the Asia-Pacific Islands, and Indigenous communities, remain underrepresented.This article presents two museum-based projects: the University of St Andrews-led Shared Island Stories research project and the International Committee of Museology (ICOFOM)'s global youth workshops. The first uses transnational exchanges between Scotland and Barbados to empower young people as Youth Ambassadors, fostering cultural heritage preservation and climate justice. The second engages youth from 18 countries and territories in museum-based dialogues on climate action aligned with the UN Sustainable Development Goals (SDGs).Current museum policies frequently overlook barriers faced by young people, limiting meaningful engagement and missing critical opportunities to harness their energy and creativity (Kids in Museums 2024; Yates et al. 2022; Madgin et al. 2016). Both initiatives employ participatory action research and critical pedagogy, enhancing young people's skills and positioning them as active participants in climate solutions. These projects illustrate that inclusive museum practices aimed at amplifying youth voices are essential for achieving climate justice and fostering sustainable, equitable futures
Concurrent linear deracemization of secondary benzylic alcohols via simultaneous photocatalysis and whole-cell biocatalysis
No full textPhotobiocatalysis enables remarkable synthetic transformations by combining the exquisite stereoselectivity of enzymes with the mild generation of high-energy intermediates by photocatalysis, but practical applications remain limited due to enzyme photodamage. The deracemization of secondary alcohols is a key model reaction for photobiocatalytic protocols due to the importance of the enantioenriched products. However, current strategies rely on the temporal separation of catalytic cycles to circumvent incompatibilities, precluding photobiocatalytic transformations that require the in situ generation of reactive intermediates. We report a single-step concurrent linear deracemization protocol by combining a water-soluble photocatalyst (sodium anthraquinone-2-sulfonate) with a promiscuous alcohol dehydrogenase (Geotrichum candidum acetophenone reductase) encapsulated in lyophilized microbial whole cells. Insights into enzyme selectivity and system dynamics from molecular docking and kinetic modeling guided the optimization of the multicomponent system. Our approach represents a modular and generalizable strategy for developing photobiocatalytic cascades operating under mutually compatible conditions, wherein spatial separation mitigates photodamage and enables simultaneous dual catalytic turnover
Global need for climate advocacy, education and evidence in paediatrics
No full textClimate change is the single greatest existential threat to children worldwide, adversely affecting the health and well-being of children and young people. The Royal College of Paediatrics and Child Health members living outside the UK (respondents) were invited to an online anonymised survey where opting-in participants answered 32 questions covering 6 domains. 139 respondents from 50 countries responded to the survey. Respondents agreed that climate change influences the rising rates of children with heat-related (50%), infectious (64%) and mental health (36%). The climate crisis is a global emergency, and working together is paramount to safeguarding the planet for future generations
Host–guest engineering of MOF-808 for random lasing and solid-state emission
No full textFluorescent organic dyes have a broad range of applications across various fields. However, their use is threatened by stability issues such as photobleaching and aggregation-caused quenching that prevent them from showing solid-state luminescence and being used in high-power photonics applications for a long period. One possibility to overcome these problems is to embed dye molecules within a hosting platform. Metal–organic frameworks (MOFs) are among the best candidates to overcome these problems due to their porous nature, which provides excellent sorption capacities while ensuring stability for potential guest molecules, even in extreme environments. In this work, we investigate the optical performance of rhodamine B and coumarin 343 when interacting with Zr-based MOF-808. On one hand, we demonstrate that inclusion of dye molecules in MOF-808 cavities prevents aggregation-induced quenching, enabling the use of dyes in powdered form and enhancing their emission in solid-state applications, such as fingerprint detection. On the other hand, the dye–MOF interaction in solution reveals that MOF-808 nanoparticles act as efficient scatterers, significantly enhancing random lasing emission by narrowing the emission spectra and reducing the lasing threshold. The lasing performance is shown to be dependent on the MOF concentration and excitation intensity, with an optimal concentration minimizing the threshold and bandwidth. Finally, we demonstrate the feasibility of combining MOF-808 nanoparticles and dyes into polymeric thin films, where the MOFs contribute to halving the lasing threshold, making the system suitable for portable lasing applications
Cardiac safety of bedaquiline, delamanid and moxifloxacin co-administered with or without varying doses of sutezolid or delpazolid for the treatment of drug-susceptible TB
No full textIntroduction: Many drugs for the treatment of TB prolong the QTc interval, which is associated with an increased risk of developing a life-threatening arrhythmia known as torsades de pointes. Sutezolid and delpazolid are novel oxazolidinones with demonstrated bactericidal activity. We aimed to assess the effects of sutezolid or delpazolid co-administered with bedaquiline, delamanid and moxifloxacin on the QTcF interval (Fridericia’s correction). Furthermore, we developed a population pharmacodynamic model to assess the effects of drug exposure on the QTcTBT interval (TB-specific correction). Methods: Participants were randomized to receive standard-dose bedaquiline, delamanid and moxifloxacin with varying doses of either sutezolid (no sutezolid, 600 mg daily, 1200 mg daily, 600 mg twice daily, 800 mg twice daily) or delpazolid (no delpazolid, 400 mg daily, 800 mg daily, 1200 mg daily, 800 mg twice daily). The QTc interval was determined using weekly ECG assessments. Results: Data from 149 participants, yielding 2373 ECG observations were available for analysis. Nine participants (6.0%) experienced a Grade 3 QTcF prolongation as defined by the Common Terminology Criteria for Adverse Events v5.0. The population pharmacodynamic model predicted a 13.2 ms (95% CI: 10.9–15.3) increase of the QTcTBT in the first week of treatment, but no further increase after that. The exposure of bedaquiline’s M2 metabolite was found to drive part of the QTcTBT. No exposure–response relationship was identified for the other drugs investigated. Conclusions: The drug regimens containing standard doses of bedaquiline, delamanid and moxifloxacin, and varying doses of sutezolid or delpazolid were not found to pose a high cardiac risk in a population without further QTc-relevant risk factors. However, close monitoring of the QTc interval remains essential in patients with TB treated with combination drug therapy with known QTc-prolonging drugs