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Pink Cricket Club:dramatic color change in a neotropical leaf-masquerading katylid (<i>Arota festae</i>, Griffini, 1896)
No full textAGN STORM 2. XI. Spectroscopic reverberation mapping of the hot dust in Mrk 817
No full textThe AGN Space Telescope and Optical Reverberation Mapping (STORM) 2 campaign targeted Mrk 817 with intensive multiwavelength monitoring and found its soft X-ray emission to be strongly absorbed. We present results from 157 near-IR spectra with an average cadence of a few days. Whereas the hot dust reverberation signal as tracked by the continuum flux does not have a clear response, we recover a dust reverberation radius of ∼90 lt-days from the blackbody dust temperature light curve. This radius is consistent with previous photometric reverberation mapping results when Mrk 817 was in an unobscured state. The heating/cooling process we observe indicates that the inner limit of the dusty torus is set by a process other than sublimation, rendering it a luminosity-invariant “dusty wall” of a carbonaceous composition. Assuming thermal equilibrium for dust optically thick to the incident radiation, we derive a luminosity of ∼6 × 1044 erg s−1 for the source heating it. This luminosity is similar to that of the obscured spectral energy distribution, assuming a disk with an Eddington accretion rate of ṁ ~ 0.2. Alternatively, the dust is illuminated by an unobscured lower luminosity disk with ṁ ~ 0.1, which permits the UV–optical continuum lags in the high-obscuration state to be dominated by diffuse emission from the broad-line region. Finally, we find hot dust extended on scales ≳ 140–350 pc, associated with the rotating disk of ionised gas we observe in spatially resolved [S III] λ9531 images. Its likely origin is in the compact bulge of the barred spiral host galaxy, where it is heated by a nuclear starburst
Engineering site disorder to give rise to enhanced conductivity in a scandia-stabilised zirconia electrolyte via disruption of short-range ordering
No full textConductivity degradation is the key limitation associated with zirconia electrolytes, especially within the scandia doped compositions. This is strongly associated with defect ordering, suggesting that introduction of cation disorder could overcome such degradation. The system Sc0.15+x[In0.05Mg0.0125]Zr0.7875-xO1.8875-x/2, x = −0.125, 0 (IMSSZ), 0.125 addressed in this study shows an unusual conductivity degradation-recovery-enhancement profile where the conductivity degrades for a short period of time then recovers and exceeds its initial value. The conductivity at 850 °C in air was found to recover to the initial value of 0.096 S cm−1 in less than 25 h, and then it continues to improve up to 0. 11 S cm−1 after 250 h. Starting with a brief introduction on the origin of short-range ordering hence long-term conductivity degradation in the fluorite materials, this paper presents a detailed structural characterisation of this special composition with a focus on short-range structure through electron diffraction, TOF neutron diffraction and impedance spectroscopy. We conclude that the conductivity degradation is caused by pyrochlore and rare-earth C-type related short-range ordering, whereas the conductivity increase and stabilisation observed in this composition is a result of dopant segregation to grain boundaries, with the altered bulk composition destabilising and eliminating such defect short-range ordering and moving towards a stable disordered fluorite structure
Mass estimates of the young TOI-451 transiting planets: Multidimensional Gaussian Process on stellar spectroscopic and photometric signals
No full textThe young TOI-451 planetary system, aged 125 Myr, provides a unique opportunity to test theories of planetary internal structures and atmospheric mass loss through examination of its three transiting planets. We present an exhaustive photometric and spectroscopic follow-up to determine the orbital and physical properties of the system. We perform multidimensional Gaussian Process regression with the code pyaneti on spectroscopic time-series and NGTS/LCO light curves to disentangle the stellar and planetary signal in ESPRESSO radial velocities. We show how contemporaneous photometry serves as an activity indicator to inform RV modelling within a multidimensional Gaussian Processes framework. We argue that this can be exploited when spectroscopic observations are adversely affected by low signal-to-noise and/or poor sampling. We estimate the Doppler semi-amplitudes of Kb = 2.6(+1.1,-1.2) m/s, Kc = 1.2(+1.0,-0.8) m/s and Kd = 2.7 +/- 1.2 m/s. This translates into 2-sigma mass estimates for TOI-451 b and d of Mb = 4.7(+2.1,-2.2) Earth masses and Md = 10.2(+4.6,-4.5) Earth masses, as well as a mass upper limit for TOI-451 c of Mc < 11.5 Earth masses. The derived planetary properties suggest that planets c and d contain significant hydrogen-rich envelopes. The inferred parameters of TOI-451 b are consistent with either a rocky world that still retains a small hydrogen envelope or a water world. These insights make the TOI-451 system an ideal laboratory for future follow-up studies aimed at measuring atmospheric compositions, detecting atmospheric mass-loss signatures, and further exploring planetary formation and evolution processes
Community acceptance of nature‐based solutions for coastal flood risk management
No full text1. Coastal areas are increasingly vulnerable to climate change impacts, such as rising sea levels and more frequent storm events, necessitating urgent adaptation strategies. Various adaptation approaches exist, including hard engineering solutions and nature-based solutions, but whether these strategies are implemented often depends on social acceptance by local communities. Understanding the factors that influence community acceptance, such as trust, knowledge and perceived effectiveness, is vital for coastal risk management.2. This study employed a mixed methods approach across four diverse case study sites in the United Kingdom—St Andrews (Scotland), Airth (Scotland), Hesketh Bank (England) and Pensarn (Wales). We employed a postal survey and focus groups to gather both quantitative and qualitative data, ensuring a comprehensive understanding of local perceptions and values.3. A total of 328 valid responses were gathered across four sites, with variations in response rates and demographic characteristics, notably age and education. Awareness of Nature-based Solutions (NbS) was low in Hesketh Bank, Pensarn and Airth, only respondents in St Andrews were more familiar with the term. Qualitative analysis identified 68 community and individual-level factors, scheme characteristics and sociopolitical factors that influence social acceptance of coastal flood risk schemes.4. Participants emphasised the importance of local knowledge and landscape values but expressed low trust in government authorities and a lack of confidence in influencing local decisions. The study highlights the complexity of community acceptance of NbS for coastal flood risk management, indicating that local perceptions are influenced by a combination individual factors such as trust; the characteristics of schemes; and the ways in which governance systems interact with local communities. Context is also important with certain factors being site specific.5. Synthesis and applications. Community acceptance plays a crucial role in implementing coastal schemes, highlighting the importance of addressing the interests, values and experiences of local communities. Building trust and engaging stakeholders early in the planning stages to overcome potential push back due to uncertainties is critical. Collaborative and whole-systems approaches are also essential to ensure that the benefits of NbS are effectively communicated and integrated
FedFreeze:a dual-phase layer freezing framework for federated learning
No full textRunning Federated Learning (FL) on resource-constrained devices is challenging due to the resources required for training. Layer freezing has been proposed to reduce the computational costs and thus accelerate training. However, we identify that existing layer freezing approaches either learn quickly or learn effectively, but do not balance them. Specifically, aggressive early-stage layer freezing (e.g., AutoFreeze) accelerates training but achieves a lower final accuracy. On the other hand, accuracy-guaranteed layer freezing (e.g., ALF) obtains higher final accuracy but with marginal training time improvement. This article proposes FedFreeze – a dual-phase layer freezing federated learning framework that, for the first time, combines early-stage and accuracy-guaranteed layer freezing into a unified mechanism. FedFreeze designs a novel regularization-based layer freezing strategy on the device to apply early-stage layer freezing even during the initial stages for improving training speedup. In addition, FedFreeze develops a convergence-based layer freezing strategy to achieve a high final accuracy. Experimental results show that the proposed FedFreeze framework achieves up to 1.3 × training speedup while limiting the accuracy drop to no more than 1.67 % compared to vanilla FL. In contrast to state-of-the-art early-stage and accuracy-guaranteed layer freezing methods, FedFreeze consistently strikes a better balance between efficiency and accuracy across a wide range of settings, including different hardware platforms (Raspberry Pi and Jetson Nano clusters), datasets (FMNIST, CIFAR-10, CIFAR-100), model architectures (AlexNet, VGG11, ResNet12), and initialization strategies. The results demonstrate that FedFreeze outperforms state-of-the-art layer freezing techniques in accelerating FL training on resource-constrained devices, without incurring significant accuracy loss
Syntheses, characterization, Hirshfeld analysis, and antioxidant activity of Co(II) and Ag(I) complexes based on oxadiazole ligand
No full textThe antioxidant activities of [Co(L)2Cl2]·0.25H2O and [Ag2(L)2]n(ClO4)2n complexes with 2-(5-(pyridin-2-yl)-1,2,4-oxadiazol-3-yl)aniline (L) are reported to explore their molecular, supramolecular and antioxidant characteristics. Their molecular structures were examined using FTIR and other spectroscopic techniques, and single crystal X-ray diffraction. The Co(II) complex shows a discrete octahedral structure, while the Ag(I) complex is a 1D coordination polymer. Both complexes were evaluated for their antioxidant activities utilizing 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide, and superoxide anion scavenging assays. The Ag(I) complex consistently demonstrated the highest antioxidant activity across all the three assays (DPPH; IC50 = 52.07 ± 1.22 µM), (nitric oxide; IC50 = 29.14 ± 1.04 µM), and (superoxide; IC50 = 8.74 ± 1.85 µM), particularly excelling in superoxide anion scavenging. The Co(II) complex also showed enhanced activity compared to L especially in the nitric oxide (IC50= 24.70±1.65 µM), and superoxide anion assays (IC50 = 20.78 ± 2.85 µM). These findings reveal how metal-ligand systems can be tuned to enhance antioxidant efficiency, providing insight for the design of bioactive metal complexes as antioxidants
Israel, as hurt-geography
No full textIn this autobiographical narrative, Nigel Rapport recounts how his time as a volunteer at Kibbutz Yas'ur in Israel in 1975 profoundly affected his identity and sparked a deep emotional connection to the country. Despite initial reluctance to visit Israel and engage with his Jewish heritage, Rapport's experiences living and working on the kibbutz - including labouring in the citrus groves, bonding with the kibbutz youth and being embraced by the community - instilled in him a strong sense of belonging, pride, and loyalty to Israel. The essay conveys Rapport's newfound understanding of the precariousness and preciousness of life in Israel, constantly under threat of war and violence. It also expresses his anxiety and protective concern for the country's survival against what he perceives as the hatred and prejudice of its enemies. Rapport's connection to Israel is further cemented by the normalcy of Jewish life there, a stark contrast to the marginalization he felt growing up in Britain. The recent Hamas attacks in 2023, with their devastating loss of life, underscore the enduring ‘hurt geography’ of Rapport's relationship with Israel. The essay ultimately presents a highly personal account of the author's transformative encounter with Israel and Zionism and the complex emotions and loyalties it engendered
Conceptual engineering as inquiry
No full textThis paper defends what we call the Straightforward View of conceptual engineering. Canonical examples of conceptual engineering are simply cases in which a proposition is endorsed or denied at one time, and this endorsement or denial is subsequently retracted; and this phenomenon is continuous with belief- and theory-change in science, history, and other areas of investigation. Put simply, conceptual engineering is inquiry. This view is consistent with standard characterisations of conceptual engineering as potentially revisionary, as ameliorative, and as a matter of assessing and improving representational devices. We reject the alternative Meaning Change View of the canonical examples, according to which they involve changing the meaning of some term on the grounds that it is unmotivated. We also defend a novel version of the implementation objection to the Meaning Change View: the proponent of Meaning Change’s best strategy for defending the idea that the conceptual engineering is ameliorative makes it impossible that meaning be changed
Changing EAP assessment practices in the age of generative artificial intelligence:the case of Scottish higher education institutions
No full textThe impact of generative artificial intelligence (GenAI) on higher education has been widely discussed since the public release of ChatGPT-3.5 in late 2022. However, there has been little empirical research on changes in English-for-Academic-Purposes (EAP) assessment practices in response to GenAI. This qualitative case study intends to fill this gap by examining how Scottish universities changed EAP assessments in response to GenAI, how effective those changes were perceived by EAP academics, and what recommendations EAP academics offered for future assessment practices. Data were collected from six semi-structured interviews conducted with EAP academics at five Scottish universities in mid-2024 and thematically analysed. The findings reveal that while substantial changes in assessment task design were limited, modifications to task requirements (e.g., GenAI declarations, context-specific prompts) and grading practices were more common. Moreover, our participants expressed scepticism about the effectiveness of some changes (e.g., AI use declarations) but positively perceived others (e.g., the use of context-specific questions, spontaneous speaking tasks, and named marking). As for their recommendations, the participating EAP academics generally advocated authentic and innovative tasks, such as portfolio-based assessment, reflections, multimodal projects, and GenAI output evaluation over reverting to traditional exams while simultaneously highlighting issues with workload and learning outcomes. The study implies a need for clearer institutional guidance, ongoing professional dialogue, and support for experimentation with GenAI-integrated assessment design in EAP contexts
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