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Spectroscopic Analysis of the Complex Refractive Indices for Imine Brown Carbon Aerosol Particles
No full textBrown carbon (BrC) contributes substantially to light absorption by atmospheric aerosols, which represents a key uncertainty in estimates of aerosol radiative forcing. Among its diverse constituents, imine BrC formed from aqueous reactions between glyoxal and nitrogen-containing species is of widespread interest. We report sensitive measurements of particle size-resolved optical cross sections, associated retrievals of complex refractive indices (m = n + ik), and effective density measurements for imine BrC aerosols generated from aqueous solutions containing glyoxal and nitrogen species across a wide pH range. An Aerodynamic Aerosol Classifier was coupled with cavity ring-down and photoacoustic spectroscopy to measure extinction and absorption cross sections at the short-visible wavelength of 405 nm, enabling retrievals of n and k with high precision and accuracy while eliminating multiply charged particle artifacts that impair more common mobility-based approaches. Detectable light absorption was observed under basic conditions (pH ≈ 9.5) only, yielding values of k in the range 0.0016–0.0018 and n of ∼1.50, demonstrating that imine BrC may contribute modest absorption at short-visible wavelengths. Meanwhile, aerosols generated from aqueous solutions under acidic and near-neutral conditions were nonabsorbing (k < 10–4). Comparison with bulk UV/vis absorption spectra indicates that aerosolization and drying enhanced chromophore formation under basic conditions, likely through the supersaturation of dissolved reacting solutes in drying aqueous aerosol droplets. Measured values for effective particle density were consistent with the formation of partially oligomerized glyoxal hydrates
No Ethics Needed? Towards an Ethics of Care for Public and Patient Involvement and Engagement
No full textIntroduction: Public and Patient Involvement and Engagement (PPIE) enhances the inclusivity, relevance and responsiveness of health research for communities. Although public and patient involvement is grounded in lived experience and typically falls outside formal ethical review, ethical considerations nonetheless arise. This paper therefore examines PPIE concepts and practices through an EoC lens. Method: Through a thematic, iterative review of the literature, this paper examines PPIE practices, analysing these by drawing on feminist scholarship, notably the EoC perspective and intersectionality, to explore how lived experience is constructed within health research. Results: The EoC perspective can play an important guide for help researchers to promote inclusive team cultures, strengthen their PPIE activity and respond to marginalised groups of people in complex situations. It can help to address criticisms of PPIE, on account of the ‘harm’ patient/public contributors can experience based on (hidden) emotional labour, alongside power imbalances, and existent health vulnerabilities. Whilst there exists some guidance concerning PPIE in terms of reporting, the paper proposes an EoC lens underlining five overlapping aspects: attentiveness, responsibility, competence, responsiveness and solidarity to improve inclusivity, mitigate harms and reshape relationships between researchers and participants. Conclusion: An EoC approach reframes ethics, for PPIE, not as a procedural task. It highlights that an EoC is a form of relational ethics and underlines the ongoing relational practice that makes up PPIE, which demands attentiveness to lived experience, structural inequalities and the emotional realities of involvement. This perspective strengthens the ethical integrity of PPIE by encouraging more reflexive, compassionate and equitable engagement across research contexts. Patient or Public Contribution: Members of a parent carer network were involved in preparing the manuscript. They reviewed the paper in both a lay summary version and the longer full version, providing written and verbal feedback. Their suggestions have been incorporated into the main text, including the addition of examples in the table
Distinct roles of cortical layer 5 subtypes in associative learning
No full textAdaptive behavior relies on associating sensory cues with rewarding or aversive outcomes. In mammals, the primary sensory cortex processes stimuli and distributes information to cortical and subcortical targets. Layer 5 (L5) contains two major projection neuron classes, intratelencephalic (IT) and extratelencephalic (ET); however, their roles in associative learning remain unclear. Using transgenic mice, we identified IT and ET neurons in primary somatosensory cortex and tracked their activity with longitudinal two-photon imaging during Pavlovian conditioning with whisker stimulation. IT neurons stably encoded stimulus identity across training, whereas ET neurons showed dynamic changes that paralleled the emergence of anticipatory licking. Chemogenetic silencing of each subtype impaired learning in distinct, phase-specific ways. A reinforcement-learning model reproduced these dynamics, suggesting that IT neurons provide stable sensory representations needed to form cue-reward associations, while ET neurons encode reward expectation to refine behavior. These findings reveal complementary, cell-type-specific contributions of L5 neurons to associative learning
Drivers of bat researchers’ intent to adopt field hygiene practices
No full textInfectious disease is a growing threat to wildlife, with zoonotic transmission most likely at the human–wildlife interface. One underappreciated activity at this interface is fieldwork with wild animals, but associated risks can be mitigated through field hygiene (FH) practices, such as using personal protective equipment and other appropriate behaviors. Following the dissemination of International Union for Conservation of Nature FH guidelines for bat researchers, we investigated factors that affect bat researchers’ intent to use FH practices under a theory of planned behavior (TPB) framework. Under the TPB, a person's intent to perform a behavior is influenced by their attitude toward, their subjective norms around, and their perceived behavioral control (PBC) about the behavior. We invited researchers who had recently conducted bat‐related fieldwork to complete a qualitative questionnaire, generating data that we used to build a quantitative survey, which we disseminated widely to bat researchers. We analyzed ∼1000 survey responses with structural equation modeling and assessed the role of career stage, research focus, and socioeconomic status of the research location on intent. Bat researchers’ intent to adopt FH practices was high overall. For those who do not focus on disease projects, the subjective norm was a strong driver of intent, with mentors the most influential norm referents; authoritative bodies that set regulations and peers were influential too. The only modeled barrier to intent was PBC—with beliefs that FH practices are impractical or uncomfortable contributing most to PBC. We concluded that senior researchers should be encouraged to use FH practices and encourage their mentees to do likewise. Technical solutions and education to mitigate impracticality and discomfort issues should also be encouraged. Although we focused on bat researchers, all wildlife fieldwork entails pathogen transmission risks. To mitigate them, FH practices must become entrenched in the wildlife research community; achieving this goal requires regulatory and social measures
Volatile-rich evolution of molten super-Earth L 98-59 d
No full textAbstract
Small, low-density exoplanets are sculpted by strong stellar irradiation, but their primordial compositions and subsequent evolution are still unknown. Two often-considered scenarios hold that they formed with rocky interiors and H
2
–He atmospheres (‘gas dwarfs’) or alternatively with bulk compositions dominated by H
2
O phases (‘water worlds’). Here we constrain the possible range of evolutionary histories linking the birth conditions of low-density super-Earth L 98-59 d to recent observations using a coupled atmosphere–interior evolutionary model. We find that the observations can be explained by in situ photochemical production of SO
2
in an H
2
background, indicative of a chemically reducing mantle and substantial (>1.8 mass%) early sulfur and hydrogen content, inconsistent with both the gas-dwarf and water-world scenarios. L 98-59 d’s interior comprises a permanent magma ocean, allowing long-term retention of volatiles within its mantle over billions of years, consistent with California-Kepler Survey trends. Our analysis reveals an evolutionary pathway in which planets host volatile-rich atmospheres sustained by long-term magma-ocean degassing, shaped by secular cooling, atmospheric erosion and photochemistry. Internal and environmental processes contribute to the observed diversity of super-Earth and sub-Neptune exoplanets
Structural studies of E1-E2 interactions in the ubiquitin cascade
No full textThe conjugation of ubiquitin to substrate proteins underpins nearly all eukaryotic cellular pathways. In vertebrates, this process is initiated by two essential ubiquitin-activating enzymes (E1s), UBA1 and UBA6. Recent studies have shown that each E1 directs independent downstream pathways through distinct ubiquitin-conjugating enzymes (E2s), yet the mechanisms governing E2 selection remain unclear.Here, in vitro E2 activity screens combined with cryoEM structures of the two UBA6-specific E2s in complex with UBA6 provide new insight into the molecular interactions driving E1-E2 specificity in the ubiquitin cascade. This framework was then applied to generate E2 mutants with altered E1 specificities, offering potential tools to dissect E1-specific pathways in cells.Additionally, this work identifies a unique priority mechanism for the UBA6-specific E2 BIRC6, enabled by a uniquely high affinity E1-E2 interaction. Further analysis revealed that the Cys-cap loop of UBA6 dampens E2 affinities, which allows UBA6 to function with a high affinity E2 without being inhibited. These findings outline an affinity-driven hierarchy among E2s, balanced by an E1 regulatory element to ensure efficient E2 turnover.Overall, this work provides key mechanistic insights into how E1-E2 specificity is achieved in the ubiquitin system, highlighting both structural determinants and regulatory mechanisms that shape pathway selectivity. By uncovering unique features of UBA6-mediated interactions and identifying principles that govern E2 hierarchy, these findings not only expand our fundamental understanding of the ubiquitin cascade but also lay the groundwork for new molecular tools to probe and manipulate E1-specific cellular pathways
Sentient spaces: composition as instrument-making
No full textThis composition portfolio presents five original works composed between 2018 and 2021 which are interrelated by underlying methods and concepts that I describe as a circulation of instrument-making and speculative worldbuilding. The core research narrative explores the creation of hybrid acoustic and live electronic instruments that blur the boundaries between a musician’s physical body, their physical instrument, a digital instrument, the performance space, and the experience of the audience. Live electronics form the core of the portfolio’s compositional methodology, with the exception of the final work, The Holy Fool, which extends these ideas from electronics into an acoustic ensemble domain. Concepts and methods such as interactivity, mapping, proprioception, and homuncular flexibility help to explain the functioning of such systems, all built using Cycling 74’s Max. The type of instrumentality that I develop forms a continuum between an integrated performer–instrument–space unit and a more heterogeneous agent–environment paradigm, where human and electronic performers stand as distinct entities in a larger imaginary environment. The four electronic works in this portfolio explore different instances along this unified/heterogeneous spectrum. Of the latter category, I describe the instrument- space as a sentient space, which provides an aesthetic and technical framework throughout the portfolio and supports a broader objective that positions music as a means of disalienation from contemporary life through re-sensitising the listener to sound, space, and musical bodies. Throughout the portfolio, I return to core references that underline the speculative worldbuilding potential of music in relation to critical spatial and technological practices in art and academia, namely: the films of Andrei Tarkovsky, Mark Z. Danielewski’s novel House of Leaves, Hito Steyerl’s essays on technology in the arts, and the Situationists’ practices of psychogeography. Furthermore, the portfolio draws on concepts and methods explored in a partner musicological dissertation, which elucidates Luigi Nono’s live electronic turn and the Experimentalstudio Freiburg in the 1980s with regard to recent literature in organology, anthropology, and electronic music practices
Disability, no-powers, and personhood
No full textA legal system may shape and confine the juridical attributes of a subject in order to enhance the subject’s personhood, or the ability to form an identity, to self-govern, and to project one’s ideas and efforts in a coherent fashion to others. A disability curbing or voiding specific legal powers in relation to others can help set boundaries so that one’s remaining powers, rights and liberties are used well. The strategy of legal disability involves a subtraction or privation of legal attributes designed to strengthen or protect or discipline the legal person. The subtraction can be imposed by law, voluntarily adopted by the subject, or may involve a midway implication of law ascribing disability when the subject enters into a typical relationship or situation where holding a full power is inapt. This chapter explores how disability or curbing of powers is found across the gamut of private as well as public law, and how this assists in the constitution of legally recognized persons
Evidence for Neutrino Emission from X-Ray Bright Seyfert Galaxies in the Southern Hemisphere Using Enhanced Starting Track Events with IceCube
No full textIceCube recently reported the observation of TeV neutrinos from the nearby Seyfert galaxy NGC 1068, and the corresponding neutrino flux is significantly higher than the upper limit implied by observations of GeV–TeV gamma rays. This suggests that neutrinos are produced near the supermassive black hole, where the radiation density is high enough to obscure gamma rays. We use a set of muon neutrinos with interaction vertices inside the detector, which have good sensitivity to sources in the southern sky, from IceCube data recorded between 2011 and 2021. We then search for individual and collective neutrino signals from 14 Seyfert galaxies in the southern sky selected from the Swift Burst Alert Telescope AGN Spectroscopic Survey. Using the correlations between keV X-rays and TeV neutrinos predicted by disk–corona models, and assuming production characteristics similar to NGC 1068, a collective neutrino signal search reveals an excess of 6.7−3.2+4.0 events, which is inconsistent with background expectations at the 3σ level of significance. In this Letter, we present new independent evidence that Seyfert galaxies contribute to the extragalactic flux of high-energy neutrinos
Brain volumes after hypertensive pregnancy and postpartum blood pressure management
Get PDFImportance Hypertensive pregnancy increases risk of cognitive decline, stroke, and dementia, especially after preeclampsia. Women with prior hypertensive pregnancy show lower brain volumes, but it was unknown whether early postpartum blood pressure optimization could alter these outcomes.
Objective To evaluate whether an intervention designed to achieve better postpartum blood pressure control after a hypertensive pregnancy is associated with differences in brain volumes around 9 months post partum compared with usual care.
Design, Setting, and Participants This randomized clinical trial, the Physician Optimized Postpartum blood pressure self-management trial (POP-HT), was a prospective, open-label, blinded end-point study conducted at a single tertiary center in the UK. Participants were older than 18 years and had preeclampsia or gestational hypertension requiring antihypertensive treatment at hospital discharge. Enrollment began February 21, 2020; the last follow-up was on November 2, 2021; and the mean follow-up time was approximately 9 months. Secondary outcome analyses (primary results published 2022) were conducted May 2025.
Interventions Telemonitored self-management with research physician-guided titration or usual postnatal care.
Main Outcomes and Measures This substudy analyzed the secondary outcomes T1-weighted magnetic resonance imaging (MRI) brain volumes (gray matter, white matter, cerebrospinal fluid, subcortical structures) acquired approximately 9 months post partum. Analyses used linear regression models adjusted for total intracranial volume.
Results Of 252 eligible participants, 32 declined, and 220 were randomized (mean [SD] age, 33.4 [5.1] years). The T1 brain MRI of 157 participants was available for analysis; 96 participants (63%) had preeclampsia, and 56 (37%) had gestational hypertension. The intervention group (n = 81) had larger total white matter volumes (adjusted mean difference, 11.50 cm3; 95% CI, 2.04 to 20.96; P = .02) compared with the usual care group (n = 71). In usual care, participants with preeclampsia had smaller putamen (adjusted mean difference, −0.83 cm3; 95% CI, −1.20 to −0.46; P < .001), accumbens (adjusted mean difference, −0.15 cm3; 95% CI, −0.24 to −0.05; P = .003), and pallidum (adjusted mean difference, −0.13 cm3; 95% CI, −0.26 to −0.01; P = .04) volumes compared with those with gestational hypertension. These differences were not observed in the intervention group.
Conclusions and Relevance This study found that short-term postpartum optimization of blood pressure control after hypertensive pregnancy was associated with larger brain volumes during the first year post partum. Because brain volume is a surrogate of brain health linked to tissue preservation and cognitive outcomes, these findings suggest potential neurovascular benefits that were most pronounced among women with preeclampsia.
Trial Registration ClinicalTrials.gov Identifier: NCT0427385