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Evidence for thermally activated delayed fluorescence in iridium( iii ) complexes
Full text linkIn this work we report the second ever example of a fully experimentally confirmed thermally activated delayed fluorescence (TADF) in a dinuclear Ir(iii) complex. The said complex displays a singlet–triplet gap ΔEST = 28 ± 5 meV, in agreement with the computational prediction of 31.1 meV – a value smaller than the previous TADF Ir(iii) complex. We also demonstrate a proof-of-concept, solution-processed OLED featuring this complex as the luminescent dopant in the emissive layer, achieving external quantum efficiency of up to ∼10% and maximum luminance of 18 000 cd m−2 – values significantly exceeding those reported earlier for Ir(iii) TADF. These findings are preceded by a detailed consideration of spectral signs of TADF in the already known Ir(iii) complexes. The spectral overlap of photoluminescence (PL) with strong (i.e., spin-allowed) absorption bands is unusual for phosphorescent metal complexes, because the PL originates from the triplet state, which is normally significantly lower in energy than the lowest-lying singlet. In this study, we have scrutinized literature data on iridium(iii) complexes that likewise show significant overlap between absorption and PL, and we conclude that a small singlet–triplet energy gap ΔEST in these complexes results in a TADF contribution to their emission. Such a mechanism has hitherto been overlooked in the large body of iridium(iii) chemistry. We use computations to clarify the nature of the excited states in these complexes, demonstrating that the distinctive S1 and T1 character of states can be identified as well as confirming that ΔEST is small enough for TADF to occur at room temperature
Pronounced increase in biface knapping skill half a million years ago in Britain
Full text linkFlake scar patterning indicates Acheulean knappers were attempting to make thin, symmetrical handaxes with regular edges. In this study we quantify these elements of handaxe form and test the variation between the first two waves of Acheulean occupation in Britain. The results show a marked contrast between these groups in thinness, symmetry, and edge regularity. Handaxes from sites such as Fordwich dated to >0.56 Ma are crude, whereas those from sites including Boxgrove dated to ~0.48 Ma are highly refined. This contrast in biface skill outcomes seems to have been facilitated by the use of soft-hammers and platform preparation, both of which are evident at Boxgrove. Furthermore, it suggests an increase in hominin motor control around half a million years ago that may have implications for the emergence of speech
Airborne and Ground-based NIBs for On-Demand Coverage with User Disparity and SWIPT
No full textIn emergency scenarios with incapacitated (compromised/ absent) fixed communication infrastructure, ensuring reliable on-demand and dynamic network coverage becomes critical for rapid and effective disaster management. This paper proposes a novel framework for deploying network-in-a-box (NIB) solution using a hybrid model that integrates ground-based NIBs for accessible areas and airborne NIBs for restricted areas. We adopt priority-based non-orthogonal multiple access (PB-NOMA) for the multi-user multi-antenna downlink/uplink (DL/UL) communications between NIBs and single-antenna ground users. We further employ simultaneous wireless information and power transfer (SWIPT) for the priority user (PUs) to replenish their device batteries for continued operation while transferring wireless information to the general users (GUs). Our proposed approach addresses the key challenges such as terrain-aware rapid deployment, dynamic resource allocation, complete/partial power outages, and seamless connectivity with the aim to maximize the generalized global energy efficiency (GGEE). Our simulation results demonstrate the effectiveness of the adopted system to provide robust on-demand communications while dynamically adapting to user traffic demands, environmental constraints, and emergency scenarios with up to 60%, 33%, 100%, and 35% improvement in average GGEE, spectral efficiency, energy efficiency, and throughput, respectively
Adaptation of the Japanese Version of the 12-Item Attitudes Towards Artificial Intelligence Scale for Medical Trainees: Multicenter Development and Validation Study
No full textIn the current era of artificial intelligence (AI), use of AI has increased in both clinical practice and medical education. Nevertheless, it is probable that perspectives on the prospects and risks of AI vary among individuals. Given the potential for attitudes toward AI to significantly influence its integration into medical practice and educational initiatives, it is essential to assess these attitudes using a validated tool. The recently developed 12-item Attitudes Towards Artificial Intelligence scale has demonstrated good validity and reliability for the general population, suggesting its potential for extensive use in future studies. However, to our knowledge, there is currently no validated Japanese version of the scale. The lack of a Japanese version hinders research and educational efforts aimed at understanding and improving AI integration into the Japanese health care and medical education system. We aimed to develop the Japanese version of the 12-item Attitudes Towards Artificial Intelligence scale (J-ATTARI-12) and investigate whether it is applicable to medical trainees. We first translated the original English-language scale into Japanese. To examine its psychometric properties, we then conducted a validation survey by distributing the translated version as an online questionnaire to medical students and residents across Japan from June 2025 to July 2025. We assessed structural validity through factor analysis and convergent validity by computing the Pearson correlation coefficient between the J-ATTARI-12 scores and scores on attitude toward robots. Internal consistency reliability was assessed using Cronbach α values. We included 326 participants in our analysis. We used a split-half validation approach, with exploratory factor analysis (EFA) on the first half and confirmatory factor analysis on the second half. EFA suggested a 2-factor solution (factor 1: AI anxiety and aversion; factor 2: AI optimism and acceptance). Confirmatory factor analysis revealed that the model fitness indexes of the 2-factor structure suggested by the EFA were good (comparative fit index=0.914 [>0.900]; root mean square error of approximation=0.075 [<0.080]; standardized root mean square residual=0.056 [<0.080]) and superior to those of the 1-factor structure. The value of the Pearson correlation coefficient between the J-ATTARI-12 scores and the attitude toward robots scores was 0.52, which indicated good convergent validity. The Cronbach α for all 12 items was 0.84, which indicated a high level of internal consistency reliability. We developed and validated the J-ATTARI-12. The developed instrument had good structural validity, convergent validity, and internal consistency reliability for medical trainees. The J-ATTARI-12 is expected to stimulate future studies and educational initiatives that can effectively assess and enhance the integration of AI into clinical practice and medical education systems. [Abstract copyright: © Hirohisa Fujikawa, Hirotake Mori, Kayo Kondo, Yuji Nishizaki, Yuichiro Yano, Toshio Naito. Originally published in JMIR Medical Education (https://mededu.jmir.org).
Unveiling the Sources of X-Ray Luminosity in DESI Galaxy Groups: Insights from the SRG/eROSITA All-sky Survey
Full text linkWe use the first eROSITA all-sky survey to investigate the contributions of active galactic nuclei (AGN) and extended gas to the total X-ray luminosity (LX) of galaxy groups with different halo masses (Mh) at different redshifts. The presence of AGN in their central galaxies is identified using multiwavelength catalogs, including the X-ray counterparts, the ASKAP radio catalog, and the DESI spectroscopic measurements. We apply the stacking method to obtain sufficient statistics for the X-ray surface brightness profile and the LX for groups with different central AGN properties. We find that the X-ray groups exhibit the highest LX, followed by groups with QSO, radio, Baldwin–Phillips–Terlevich AGN, and non-AGN centrals. Moreover, the LX of the Mh ≲ 1013h−1M⊙ groups is dominated by the central AGN, while the X-ray emission from extended gas tends to be more prominent in the Mh ≳ 1013h−1M⊙ groups. In groups where the AGN play a major role in X-ray emission, the contribution from extended gas is minor, resulting in significant uncertainties concerning the extended X-ray emission. When the subset containing the X-ray-detected counterparts is excluded, the extended gas component becomes easier to obtain. A correlation has been identified between the X-ray luminosity of the central AGN and extended gas. However, once we account for the positional offset, their correlation becomes less prominent. Currently, the results are not conclusive enough to confirm whether there is a connection between the AGN feedback and extended gas. However, they provide a new perspective on the feedback processes in the history of group assembly
Diffusion-Free Dynamics in Rotating Spherical Shell Convection Driven by Internal Heating and Cooling
No full textThe bulk properties of convection in stellar and giant planet interiors are often assumed to be independent of the molecular diffusivities, which are very small. By contrast, simulations of this process in rotating, spherical shells, which are typically driven by conductive boundary heat fluxes, generally yield results that depend on the diffusivity. This makes it challenging to extrapolate these simulation results to real objects. However, laboratory models and Cartesian-box simulations suggest that diffusion-free dynamics are more readily obtained if convection is driven using prescribed internal heating and cooling instead of boundary fluxes. Here, we apply this methodology to simulations of Boussinesq, hydrodynamic rotating spherical shell convection. We find that this setup unambiguously yields diffusion-free behaviour for some bulk properties of the convection, such as the radial temperature contrast and the convective heat transport. Moreover, the transition from prograde to retrograde equatorial zonal flow is diffusion-free and only depends on the convective Rossby number. The diffusivity dependence of other bulk properties is regime-dependent. In simulations that are rotationally constrained, the convective velocities, and the strength and structure of the zonal flow, are diffusion-dependent, although the zonal flow appears to approach a diffusion-free state for sufficiently high supercriticality. In simulations that are uninfluenced by rotation, or are only influenced by rotation at large scales, diffusion-free convective velocities and zonal flows are obtained. The result that many aspects of our idealised simulations are diffusion-free has promising implications for the development of realistic stellar and giant planet convection models that can access diffusion-free regimes
Declarative Lifecycle Management for Self-Adaptive Systems
No full textSelf-adaptive systems can be realised as layered systems with a feedback loop: a managing system monitors a managed system, updates an internal model, and adjusts the managed system by means of controllers to maintain given requirements. For example, a digital twin coupled with its physical twin constitute such a self-adaptive system. As the managed system shifts between different stages in its lifecycle, these requirements, as well as the associated analysers and controllers, may need to change. The exact triggers for such shifts in a managed system are often hard to predict: they may be difficult to describe or even unknown. However, the shifts can generally be observed once they have occurred, in terms of changes in the system behaviour. This paper proposes an automated method for self-adaptation in self-adaptive systems to address shifts between lifecycle stages in a managed system. Our method is based on declarative descriptions of lifecycle stages for assets in a managed system and their associated counterparts in the managing system. Declarative lifecycle management provides a high-level, flexible method of self-adaptation for self-adaptive systems to reflect disruptive shifts between stages in a managed system
“Shape is everything: on proteins’ functions”
Full text linkProteins are often defined as the molecules that enable life thanks to the special functions they display. But what are proteins’ functions? Despite their relevance in various debates, the answer to this question is often left implicit. This paper argues that a correct characterisation of proteins’ functions must consider the native structure of the protein, building on Bellazzi’s definition of biochemical functions: proteins’ functions are dispositions associated to specific chemical and geometrical structural properties relevant for the tertiary and quaternary structure of proteins, and they contribute to specific evolved biological processes. Section 1 introduces the problem of protein’s functions. Section 2 unpacks the “structure problem” and the “function problem”, where the former inquiries into the function bearer of proteins’ function and the second into the relevant account of function. Section 3 presents an answer to the structure problem by arguing that the focus should be on native structure. Section 4 and Sect. 5 focus on the function problem and the account defended. Section 5 also considers two specific case studies, haemoglobin and crystallins, and a critical evaluation of the account. Section 6 concludes
Glacier surging and surge-related hazards in a changing climate
No full textGlacier surges are ice flow instabilities characterised by periods of acceleration, during which mass is rapidly transferred from higher to lower elevations and the glacier front often advances. Surges are typically recurrent and can substantially influence regional patterns of glacier mass loss and cause hazards impacting people and infrastructure. In this Review, we provide a global synthesis of glacier surging and the influence of climate and impacts of climate change on the distribution and behaviour of surge-type glaciers and surge-related hazards. Globally, more than 3,100 glaciers have been classified as surge-type, within which a broad range of surging behaviour has been documented. The fundamental control on surging is the evolution of basal friction leading to sustained enhanced basal sliding. Most surge-type glaciers are clustered in the Arctic/Subarctic (48.3% of all surge-type glaciers) and High Mountain Asia (50.5%), where climate conditions are conducive to the development of surge instabilities, and where there is emerging evidence that climate warming is changing surge behaviour. At least 81 surge-type glaciers globally have caused hazards, primarily in High Mountain Asia. Future research should prioritise acquiring additional spatiotemporally high-resolution remote sensing data and direct observations of basal processes during all stages of surges, improving numerical models to better capture the underlying mechanisms and diversity of surges, and projecting the behaviour and distribution of surge-type glaciers under future climate warming
The impact of the internationalization strategy of MNEs on innovation performance: the moderating role of digital transformation
No full textPurpose – This study aims to fill the research gap on how internationalization strategies (depth vs. breadth) influence the innovation performance of multinational enterprises (MNEs) in the digitalization age, and explore how digital transformation impacts the link of MNEs internationalization and innovation performance.Design/methodology/approach - The regression analysis is conducted to test the proposed hypotheses. Data are collected from the annual reports of Chinese listed MNEs. A dataset containing 2,232 firm-year observations of 757 MNEs from 2007 to 2018.Findings – The findings show that internationalization depth strategy positively affects the innovation performance of MNEs, while internationalization breadth strategy exerts negative influence. Furthermore, digital transformation strengthens the positive effect of internationalization depth strategies on innovation performance and mitigates the negative effect of internationalization breadth strategies on MNEs’ innovation performance.Originality/value – This study reveals the distinct effects of internationalization depth and internationalization breadth on innovation performance of MNEs and uncovers the moderating role of digital transformation, which provides a more complete theoretical framework for the impact of internationalization (depth vs. breadth) strategy on innovation performance in the digital age. This study also extends the theoretical insights of organizational learning in the field of internationalization and digitalization
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