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Effect of Lewis basicity on the continuous gas phase condensation of benzaldehyde with acetophenone over MgO
Get PDFFunding: The authors acknowledge the Engineering and Physical Sciences Research Council, Heriot-Watt University, and CRITICAT Centre for Doctoral Training for financial support [Ph.D. studentship to Chiara Pischetola and Fabian Hesse; Grant EP/L016419/1].We have investigated the effect of Lewis basicity in the continuous gas phase condensation of acetophenone + benzaldehyde over MgO. The catalysts were prepared by ammonia precipitation, hydration and calcination to generate MgO with modified Lewis basicity (from CO2-TPD), dXRD (4-20 nm) and specific surface area (SSA = 58 246 m2 g-1); a direct correlation between SSA and Lewis basicity is presented. The introduction of Li+ and Cs+ served to decrease SSA and increase dXRD and Lewis basicity, linked to diffusion of the cations within the crystal structure (confirmed by XRD/STEM-EDX). All MgO systems delivered the exclusive and time invariant formation of target benzylideneacetophenone. Benzylideneacetophenone production rate is sensitive to the specific (per m2) Lewis basicity. The Cs10MgO_H(773) catalyst delivered the highest rate, attributed to high density of (Lewis basic) -O2- sites involved in the rate-determining step. Our results establish the feasibility of continuous chalcone synthesis using MgO catalysts with controlled Lewis basicity.Peer reviewe
Shared determinants of poor sleep, obesity and adiposity in adolescents aged 8–18-years : a systematic review
Get PDFFunding: This review was supported by the University of St Andrews as part of a Doctoral Research Program.Relationships between multiple sleep outcomes, obesity and adiposity across childhood and adolescence have been previously reported. Health-promoting interventions to improve sleep and reduce adolescent obesity could target shared determinants of sleep and obesity. The aim of this systematic review was to systematically identify and examine research that investigated the shared determinants of poor sleep and increased adiposity or obesity in adolescents. A systematic literature search covering publications up to April 2024 was conducted across 10 bibliographic databases. Search terms included objective and subjective sleep/circadian rhythm measurements, objective adiposity measurements and adolescents aged 8–18 years. Eighty studies were included in the final review. Determinants were categorised into three different domains: socioenvironmental determinants, behavioural determinants and health determinants. Shared determinants of poor sleep and increased adiposity or obesity in adolescents aged 8–18 years included: socioenvironmental determinants (gender, ethnicity, pubertal status, academic attainment), behavioural determinants (timing of moderate-to-vigorous physical activity (MVPA), unhealthy diet choices and timing of consumption and screen time and videogaming quantity and timing) and health determinants (wellbeing). These findings suggest that sleep hygiene and the modifiable shared behavioural determinants should be targeted in health-promoting interventions, and statistical analyses should be adjusted for socioenvironmental determinants and wellbeing.Peer reviewe
Even more rapidly rotating pre-main-sequence M dwarfs with highly structured light curves : an initial survey in the lower Centaurus-Crux and Upper Centaurus-Lupus associations
Get PDFFunding: Some of the data presented in this paper were obtained from MAST. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts. This research has made use of the NASA/IPAC Infrared Science Archive (IRSA), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of NASA's Astrophysics Data System (ADS) Abstract Service, and of the SIMBAD database, operated at CDS, Strasbourg, France. This research has made use of data products from 2MASS, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center, funded by the National Aeronautics and Space Administration and the National Science Foundation. The 2MASS data are served by the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This publication makes use of data products from WISE, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration.Using K2, we recently discovered a new type of periodic photometric variability while analyzing the light curves of members of Upper Sco. The 23 exemplars of this new variability type are all mid-M dwarfs, with short rotation periods. Their phased light curves have one or more broad flux dips or multiple arcuate structures which are not explicable by photospheric spots or eclipses by solid bodies. Now, using Transiting Exoplanet Survey Satellite data, we have searched for this type of variability in the other major sections of Sco-Cen, Upper Centaurus-Lupus (UCL), and Lower Centaurus-Crux (LCC). We identify 28 stars with the same light curve morphologies. We find no obvious difference between the Upper Sco and the UCL/LCC representatives of this class in terms of their light curve morphologies, periods, or variability amplitudes. The physical mechanism behind this variability is unknown, but as a possible clue we show that the rapidly rotating mid-M dwarfs in UCL/LCC have slightly different colors from the slowly rotating M dwarfs—they either have a blue excess (hot spots?) or a red excess (warm dust?). One of the newly identified stars (TIC242407571) has a very striking light curve morphology. At about every 0.05 in phase are features that resemble icicles. The icicles arise because there is a second periodic system whose main feature is a broad flux dip. Using a toy model, we show that the observed light curve morphology results only if the ratio of the two periods and the flux-dip width are carefully arranged.Peer reviewe
Precise mass in action : assessing Ukraine’s one-way attack drone campaign against Russia
No full textThe study of drones in interstate war is rapidly evolving. Much of the existing scholarship focuses on the impact of a few types of drones, despite growth in new types. Such scholarship also makes assumptions that drones can be shot down with ease. This approach limits our understanding of their strategic value. Marcel Plichta analyses Ukraine’s use of one-way attack drones to target Russian military and industrial facilities between June 2022 and January 2025. The study finds that Ukraine’s one-way attack drones imposed severe costs on Russia, despite their vulnerability to air defence. The findings call for further research into the utility of drones and drone countermeasures in interstate wars.Peer reviewe
Swimming and acoustic calling behavior attributed to Bryde’s whales in the central North Pacific
Get PDFFunding: The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was supported by the U.S. Navy’s Living Marine Resources Program (Award Number N0002523WR0051R), Commander, U.S. Pacific Fleet (Code N465JR, Award Number N0007023WR0EP8F), and tool development necessary for this analysis was supported by the Office of Naval Research (Code 322, Award Number N0001422WX01263).A unique acoustic call type was identified and attributed to Bryde’s whales in the central North Pacific in 2015, but little is known about the distribution, calling behavior, or swimming behavior of Bryde’s whales in the region. Acoustic detections attributed to Bryde’s whales were used to localize and track individual whales on the U.S. Pacific Missile Range Facility (PMRF) in Kaua‘i, Hawai‘i. This study included 150 acoustically derived tracks from recordings spanning the years 2011–2022 with recording effort in nearly every month. Bryde’s whale movement was examined relative to calendar year, day of year, hour of day, wind speed, and acoustic calling rate. Hidden Markov models were used to identify two kinematic states (slower, less directional movement and faster, more directional movement). The findings indicate that Bryde’s whales were more likely to travel in a faster and more directional state during the daytime than at night and between May and August when compared to other times of year. The along-track acoustic cue rate was examined for 118 tracks, and the findings indicate a possible lengthening of the median inter-call interval over the duration of the study period. These results are an important first step in understanding more about behavior in Bryde’s whales, a relatively under-studied species.Peer reviewe
Unpacking the money-distance nexus : mapping the spatial configuration of exogenous entrepreneurial finance across UK entrepreneurial ecosystems
Get PDFFunding: This paper reports findings from an Economic and Social Research Council (ESRC) project “Understanding how constraints on access to finance and under-investment impact on productivity growth in smaller firms” (ES/W010259/1).Attention is now increasingly being drawn to the interconnectedness of different entrepreneurial ecosystems (EEs). Consequently, from a theoretical viewpoint EEs are increasingly being viewed from a multi-scaler rather than a mono-scaler perspective. This paper examines the spatial financial interlinkages between places and different forms and stages of entrepreneurial finance. Using a unique real-time data source of equity investments from Crunchbase, we investigate the composition of entrepreneurial finance across 30 different UK spatial locations. The core focus of the work is to uncover the composition of equity deals in terms of non-indigenous international investors and how space plays a role in influencing the prevalence of these extra-local investment deals. A novel dimension of the study is to test the “distance effects'' encountered by locations in terms of their spatial proximity to the UK’s major international hub for entrepreneurial finance: London. We found that the probability of attracting international investors varies significantly across different funding stages with late-stage ventures showing a much higher propensity to attract international investors. By unpacking the “money-distance nexus” a core finding is that proximity to London is crucial for receiving external funding from international investors. Policy implications for less advantageous EEs focus on strategies for leveraging extra-local investment.Peer reviewe
Component graphs of vector spaces and zero-divisor graphs of ordered sets
Get PDFIn this paper, nonzero component graphs and nonzero component union graphs of finite-dimensional vector spaces are studied using the zero-divisor graph of a specially constructed 0–1-distributive lattice and the zero-divisor graph of rings. Furthermore, we define an equivalence relation on nonzero component graphs and nonzero component union graphs to deduce that these graphs are the graph join of zero-divisor graphs of Boolean algebras and complete graphs. The last section characterizes the perfect and chordal nonzero component and nonzero component union graphs. Additionally, we observe that the nonzero component graph and reduced nonzero component union graph of free semi-modules could be treated as the zero-divisor graph of a 0–1-distributive lattice.Peer reviewe
A primate grammar enabling incremental processing
Get PDFFunding: Research was funded by the Swiss National Science Foundation (Project Grant 310030_185324 to K.Z.; NCCR Evolving Language, Agreement #51NF40_180888; and PCEFP1_186841 to S.M.).Characterizing the structure and function of animal communication systems provides insights into the cognitive and evolutionary processes shaping signal complexity. One key question is whether and how call sequences allow potential listeners to make predictions about the call-eliciting referents. Here, we investigated whether primate call sequences contained properties that enabled such predictive processing. We analyzed several years of experimentally elicited alarm responses from a West African forest primate, wild Olive colobus monkeys. Using Kullback-Leibler Divergence and Prediction Gain approaches, we identified a simple primate grammar that allowed predictions of referents from only minimal input. In particular, sequence-initial positions reliably discriminated urgent from non-urgent threats while the following positions increased the referential specificity regarding two main predators (eagles, leopards) and non-predatory disturbances (falling tree parts). Sequences often contained further calls, which may allow callers to either confirm the referent or to alter the conveyed information. We concluded that animal communication can contain features adapted for predictive, incremental processing, suggesting evolutionary roots older than language.Peer reviewe
Dude: dual distribution-aware context prompt learning for large vision-language model
Get PDFFunding: The authors thank the International Max Planck Research School for Intelligent Systems (IMPRS-IS) for supporting Duy M. H. Nguyen. Duy M. H. Nguyen and Daniel Sonntag are also supported by the XAINES project (BMBF, 01IW20005), No-IDLE project (BMBF, 01IW23002), and the Endowed Chair of Applied Artificial Intelligence, Oldenburg University. An T. Le was supported by the German Research Foundation project METRIC4IMITATION (PE 2315/11-1). Mathias Niepert acknowledges funding by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy - EXC and support by the Stuttgart Center for Simulation Science (SimTech).Prompt learning methods are gaining increasing attention due to their ability to customize large vision-language models to new domains using pre-trained contextual knowledge and minimal training data. However, existing works typically rely on optimizing unified prompt inputs, often struggling with fine-grained classification tasks due to insufficient discriminative attributes. To tackle this, we consider a new framework based on a dual context of both domain-shared and class-specific contexts, where the latter is generated by Large Language Models (LLMs) such as GPTs. Such dual prompt methods enhance the model’s feature representation by joining implicit and explicit factors encoded in LLM knowledge. Moreover, we formulate the Unbalanced Optimal Transport (UOT) theory to quantify the relationships between constructed prompts and visual tokens. Through partial matching, UOT can properly align discrete sets of visual tokens and prompt embeddings under different mass distributions, which is particularly valuable for handling irrelevant or noisy elements, ensuring that the preservation of mass does not restrict transport solutions. Furthermore, UOT’s characteristics integrate seamlessly with image augmentation, expanding the training sample pool while maintaining a reasonable distance between perturbed images and prompt inputs. Extensive experiments across few-shot classification and adapter settings substantiate the superiority of our model over current state-of-the-art baselines
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