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Early Cretaceous giant glendonites:a record of (sub-)millennial-scale cooling?
No full textThe Lower Cretaceous succession in Svalbard contains numerous glendonites, pseudomorphs after the cold-water carbonate mineral ikaite, which have been used in conjunction with other evidence to argue for episodic global cooling punctuating the greenhouse climates of the Early Cretaceous. Recent fieldwork in central Spitsbergen has recovered giant bladed glendonites of up to half a metre long, the largest ever recorded in a Lower Cretaceous site, and comparable in size to outlier glendonites found in similar-aged strata of the Sverdrup Basin in Arctic Canada. Unlike the rosette to pineapple-like morphologies seen in some of the largest Canadian Arctic specimens, the new finds in Svalbard appear only as single or crossed blades. These large glendonites, found clo indicate that very local variations in pore water chemistry governed whether numerous small ikaite crystals or few large crystals grew. Taken with evidence from modern ikaite and other large ancient glendonites, we argue that large glendonites such as these (>30 cm long) are pseudomorphs after ikaites that took, at the shortest, decades, but potentially millennia to even tens of millennia to attain their massive size. As growth of the parent ikaite took place in the sediments just below the seafloor of the shallow, epicontinental seas of the High Arctic (then situated at c. 63–66°N), this is consistent with the hypothesis that geologically short-term cooling episodes interrupted the background warmth of the Early Cretaceous greenhouse, although the duration, extent, and cause of such cooling is still debated
Chiral selenium-integrated multi-resonant thermally activated delayed fluorescent emitters showing improved reverse intersystem crossing rate
No full textNitrogen/carbonyl (N/C═O) based multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters are attractive due to their bright, narrowband emission and the ease with which they can be synthesized. However, their photophysics typically suffer from slow reverse intersystem crossing (RISC) because of their relatively large singlet-triplet energy gap (ΔEST). Thus, the organic light-emitting diodes (OLEDs) with these emitters typically show severe efficiency roll-off. Here, two MR-TADF emitters DiKTaSe and tBuCz-DiKTaSe have been designed and synthesized. The introduction of selenium in the form of an annelated benzoselenophene enhances spin-orbit coupling and increases the RISC rate. The twisted ortho-substituted tert-butylcarbazole moiety in tBuCz-DiKTaSe helps to suppress aggregation-caused quenching of the emission in films. In addition, the large size of the selenium atom and long C─Se bonds induce helical chirality in both DiKTaSe and tBuCz-DiKTaSe. Finally, the OLEDs with DiKTaSe showed maximum external quantum efficiency (EQEmax) of 22.7% while OLEDs with tBuCz-DiKTaSe showed a higher EQEmax of 27.8% and less-pronounced efficiency roll-off, with EQE at 100 cd m−2 (EQE100)/ EQE at 1000 cd m−2 (EQE1000) of 23.5/12.5%. These efficiency values are amongst the highest of devices employing DiKTa-based emitters. Our work provides key insight into how to judiciously employ heavy atoms to increase the performance of the emitter and the device
Shellfish carbonate in sediments:assessing historical baselines, dissolution dynamics, and carbon storage beneath shellfish farms, Marlborough, New Zealand
No full textInorganic carbon (IC) in the form of calcium carbonate (CaCO3) produced by shellfish is a key but often overlooked component of estuarine sediments, now threatened by the decline of calcifying biogenic habitats. While biocalcification can be potentially a net emitter of CO2, shellfish shells also preserve paleobiological records that can inform pre-impact baselines and support ecosystem restoration alongside aquaculture developments. However, global stressors—including overharvesting, benthic disturbance, and increased aquaculture—have distorted the sedimentary record of CaCO3. We analysed sediment cores beneath three ca.40-year-old green-lipped mussel Perna canaliculus farms to assess shell deposition rates before and after aquaculture development. Mussel shells, including those from fouling species Mytilus galloprovincialis, dominated both periods, but post-farming deposition rates increased by an average of 8-fold. Old shells in deeper sediments were from historic wild mussel reefs reduced to ca.3% of former biomass by the 1970s. We found statistically significant yet minor differences in OC and IC content between old and recent shells. These results demonstrate how shell accumulation beneath farms preserves valuable ecological archives and enhances benthic carbon stocks. Our findings offer a novel tool for aquaculture managers to reconstruct baseline conditions, monitor carbon contributions, and inform the use of shell waste in coastal rehabilitation strategies on soft sediments
Fast mapping of hominids
No full textFast mapping is essential when children acquire language, but whether therequired cognition is uniquely human or shared with animals is debated. Although documented in dogs and cats, both species have a history of domestication of social cognition, so that it remains unclear whether fast mapping is naturally present in non-domesticated animals. Here, we used an eye-tracking paradigm to test three species of hominids – gorillas, orangutans and humans – in their ability to rapidly learn to associate novel sounds with objects in their everyday noisy environment. The task was difficult for all participants, but while adult humans showed evidence of fast mapping, we could not detect any sign of learning in the other hominids. These species differences could have trivial causes, such as problems with attention or motivation, but it is also possible that fast mapping requires a preexisting lexicon before becoming an effective learning mechanism, or that it has simply evolved after the shared ancestor of all great apes.<br/
Comparative analysis of GnRH pulse generator activity in intact and gonadectomized male and female mice
No full textA subpopulation of kisspeptin neurons in the arcuate nucleus (ARN) of the hypothalamus functions as the GnRH pulse generator, driving the pulsatile secretion of LH from the anterior pituitary. Recent advances in in vivo GCaMP fiber photometry have allowed the direct measurement of ARN kisspeptin (ARNKISS) neuronal population activity in mice. In both sexes, ARNKISS neurons display large, brief calcium activity episodes, termed synchronization episodes, each corresponding to a correlated LH pulse. Here we present quantitative and comparative analyses of calcium activity in these neurons and LH profiles in male and female mice, based on a combination of previously published and unpublished data.Our findings reveal a significant sex difference in pulse generator frequency in intact mice, with males exhibiting slower and more stochastic synchronization episodes compared to females. Additional sex differences were noted in the profile of synchronization episodes. In gonadectomized mice, the synchronization frequency and the episode profiles became similar across sexes, indicating that gonadal steroids largely drive sex differences in the intact state. However, sex-specific differences in pulse frequency distributions persisted after gonadectomy, suggesting possible steroid-independent differences in the GnRH pulse generator. Sex differences in the LH pulse frequency and amplitude were observed in intact mice and were abolished following gonadectomy, highlighting the correlation between synchronization episodes and downstream hormonal signaling
<i>Glasgow: A History (Vol.1 of VI).</i> By The Tenementals. Glasgow: Strength in Numbers Records, 2024.
No full texthttps://strengthinnumbersrecords.bandcamp.com/album/glasgow-a-history-volume-i-of-v
Catholic, apostolic and orthodox
No full textCommentary on the election of Pope Leo XIV has been framed in terms drawn from political and cultural oppositions: conservative vs liberal, traditionalist vs progressive, made vivid by the 2024 film Conclave based on Robert Harris’s 2016 novel. Part of my concern is to urge rejection of these as general terms of analysis of Catholicism, or at least to circumscribe their applications to matters inessential to Catholic faith and morals per se. In aid of that, and by way of broader purpose, I discuss the nature of Catholicism itself. Observing the long history of challenges, crises, and divisions, I then proceed to distinguish between subjective and objective modes of identifying the nature of individuals and institutions. Catholicism has a robust objective nature comprising a synthesis of Hebrew and Christian scripture, apostolic tradition, conciliar and other authoritative teachings, and sacramental practices, together consolidated and expressed in orthodoxy and orthopraxy. Political and cultural classifications are irrelevant to and distracting from this identification
The CLASS (Cerebral visual impairment Learning and Awareness for School Staff) pilot study:an evaluation of the awareness of CVI amongst teachers and comparative evaluation of two different educational resources on understanding
No full textCerebral visual impairment (CVI) is the leading cause of visual impairment in children in high income countries. Despite its prevalence, awareness of CVI among educators remains low, meaning that many affected children may not receive the support they need in school. While previous research has highlighted the challenges faced by children with CVI, few studies have systematically assessed teacher awareness and the effectiveness of targeted educational interventions in improving classroom practices. This study addresses this gap by evaluating: (1) teacher awareness of CVI, (2) existing classroom practices that may impact children with CVI, (3) the effectiveness of two CVI educational media formats (video and text) in increasing understanding, and (4) the changes teachers would be willing to implement following exposure to these resources. By comparing the impact of these two formats, this study provides insights into how best to deliver CVI training for teachers in a way that is both accessible and effective. A total of 111 teachers from primary, secondary, and special schools across the UK participated in a survey incorporating either a three-minute video simulation or a 1.5-minute text-based resource about CVI. Before exposure, 72% of participants had not heard of CVI, with awareness particularly low among mainstream teachers (98% of primary and 80% of secondary teachers were unaware). Teachers also reported inconsistent use of CVI-supportive practices, such as reducing classroom clutter and simplifying smart screen content. Both media formats significantly increased teachers' willingness to implement changes (p < 0.0001). The text format showed a slightly greater increase in average Likert scores, and the Wilcoxon signed-rank test revealed a larger statistical effect for text (z = -12.91) compared to video (z = -8.90). However, the video format was also highly effective, producing a similarly strong impact, with both formats achieving an identical median increase of 1.0. These results suggest that while text may have led to slightly larger shifts in rank-based scores, the video format remained a powerful and engaging tool for increasing teachers' willingness to implement CVI-supportive strategies. The findings suggest that small, manageable adaptations, such as reducing visual distractions and maintaining consistency in classroom layouts, are practical for teachers and may have a meaningful impact on children with CVI. This study highlights the potential of bite-size learning resources in raising awareness and encouraging evidence-based teaching adaptations. By providing concise, accessible materials, teachers can be equipped with strategies to support children with CVI while minimising additional workload demands. Future efforts should focus on scaling these resources to reach a wider audience, including families and caregivers, to foster a more inclusive understanding and response to CVI.</p
A three-dimensional, multi-wavelength view and time-dependent analysis of the Milky Way's local ionized gas
No full textThis work is the continuation of a series attempting to characterize the local warm ionized medium through both static and time-dependent simulations. We build upon our three-dimensional, observationally derived simulation of the local photoionized interstellar medium – based on static photoionization simulations constrained by 3D dust maps – to include metals required to predict collisionally excited optical and infrared emission lines, providing the first all-sky prediction of a series of lines including [S II] 6716 Å, [N II] 6584 Å, and [O III] 5007 Å. While these predictions only include O-star photoionization under ionization equilibrium, we also carry out a suite of radiation-hydrodynamics simulations including time-dependent metal ionization and the effects of supernova feedback to highlight missing features in our predicted skies. We use the simulations to estimate the very local (1 kpc2) Galactic star formation rate, finding a rate of 370 M☉ Myr−1 kpc−2 provides the best match between the observationally derived and ab initio simulations. This is approximately a factor of 4 lower than previous estimates for the star formation rate required to support an observed layer of high-altitude diffuse ionized gas, possibly suggesting a ‘bursty’ star formation history in the region surrounding the Sun. We also investigate the effects of O-star environments on their ability to ionize large volumes of diffuse ionized gas, and find it is likely ionized by a small number of luminous O stars located in regions where the leakage of their Lyman continuum photons can produce the vast volumes of ionized gas observed in the mid-plane and at high galactic altitudes