32151 research outputs found
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Ethyl 4-((2-hydroxyethyl)amino)-2-(4-methoxyphenyl)-1-methyl-5-oxo-2,5-di hydro-1H-pyrrole-3-carboxylat
Get PDFFunding: The authors acknowledge Universiti Teknologi MARA for financial support and the Centre of Chemical Synthesis & Polymer Technology (CCSPT), Institute of Science, Universiti Teknologi MARA Puncak Alam, Selangor, Malaysia for the provision of laboratory facilities.In the title compound, C17H22N2O5 the pyrrolidine ring is almost planar and subtends a dihedral angle of 85.77 (7)° with the pendant phenyl ring. An intramolecular N—H⋯O hydrogen bond generates an S(6) loop. In the crystal, the compound forms inversion dimers through O—H⋯O hydrogen bonds from the disordered hydroxyl group to either the hydroxyl or ester carbonyl O atom of the adjacent molecule.Peer reviewe
Coherency properties for monoids of transformations and partitions
Get PDFFunding: Supported by the Engineering and Physical Sciences Research Council [EP/V002953/1, EP/V003224/1].A monoid S is right coherent if every finitely generated subact of every finitely presented right S-act itself has a finite presentation; it is weakly right coherent if every finitely generated right ideal of S has a finite presentation. We show that full and partial transformation monoids, symmetric inverse monoids and partition monoids over an infinite set are all weakly right coherent, but that none of them is right coherent. Left coherency and weak left coherency are defined dually, and the corresponding results hold for these properties. In order to prove the non-coherency results, we give a presentation of an inverse semigroup which does not embed into any left or right coherent monoid.Peer reviewe
Variation in faecal testosterone levels in male gray whales on a foraging ground relative to maturity and timing
Get PDFFunding: This project was supported by the NOAA National Marine Fisheries Service Office of Science and Technology, the Office of Naval Research Marine Mammals and Biology program [grant number: N00014-20-1-2760], and the Oregon State University Marine Mammal Institute, and Oregon Sea Grant [grant number: RECO-40-PD].Understanding wildlife reproductive seasonality is crucial for effective management and long-term monitoring of species. This study investigates the seasonal variability of testosterone in male Pacific Coast Feeding Group (PCFG) gray whales, using an eight-year dataset (2016–2023) of individual sightings, drone-based photogrammetry and endocrine analysis of faecal samples. We analyzed the relationship between faecal testosterone levels and total body length (TL), body condition (body area index, BAI), sexual maturity and day of the year using generalized additive mixed models. Our findings reveal a significant increase in faecal testosterone levels in mature males (MM) towards the end of the foraging season. This increase was not observed in JM, highlighting age-dependent development of sexual characteristics. No significant relationship was found between testosterone levels and TL. Additionally, BAI was not significantly associated with testosterone levels. Our results suggest that the increasing testosterone levels in MM gray whales may indicate preparation for mating before the southbound migration. These findings provide valuable insights into the reproductive biology of PCFG gray whales and underscore the importance of non-invasive faecal sampling for studying reproductive seasonality in large whales. Our approach not only provides further insights into the seasonality of male reproduction for the PCFG gray whales but also offers tools to enhance the understanding of male reproduction in baleen whales broadly with non-invasive approaches.Peer reviewe
JWST MIRI and NIRCam observations of NGC 891 and its circumgalactic medium
Get PDFFunding: JC, IDL, and MB acknowledge funding from the Belgian Science Policy Office (BELSPO) through the PRODEX project “JWST/MIRI Science exploitation” (C4000142239). MR acknowledges the support from the project PID2020-114414GB-100, financed by MCIN/AEI/10.13039/501100011033. R.C.L. acknowledges support for this work provided by a National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2102625. EWK acknowledges support from the Smithsonian Institution as a Submillimeter Array (SMA) Fellow and the Natural Sciences and Engineering Research Council of Canada. SB and VC acknowledge funding from the INAF Mini Grant 2022 program ‘Face-to-Face with the Local Universe: ISM’s Empowerment (LOCAL)’. SCOG and RSK acknowledge funding from the Heidelberg Cluster of Excellence EXC 2181 (Project-ID 390900948) ‘STRUCTURES: A unifying approach to emergent phenomena in the physical world, mathematics, and complex data’ supported by the German Excellence Strategy and from the European Research Council in the ERC synergy grant ‘ECOGAL – Understanding our Galactic ecosystem: From the disk of the Milky Way to the formation sites of stars and planets’ (project ID 855130). RSK also thanks for support from the German Ministry for Economic Affairs and Climate Action in project “MAINN” (funding ID 50OO2206). KN acknowledges support from the MEXT/JSPS KAKENHI grant numbers 19H05810, 20H00180, 22K21349, 24H00002, and 24H00241, as well as that from the Kavli IPMU, World Premier Research Center Initiative (WPI). SW gratefully acknowledges the Collaborative Research Center 1601 (SFB 1601 sub-project B6) funded by the Deutsche Forschungsgemeinschaft (DFG) – grant number 500700252.We present new JWST observations of the nearby, prototypical edge-on, spiral galaxy NGC 891. The northern half of the disk was observed with NIRCam in its F150W and F277W filters. Absorption is clearly visible in the mid-plane of the F150W image, along with vertical dusty plumes that closely resemble the ones seen in the optical. A ∼10 × 3 kpc2 area of the lower circumgalactic medium (CGM) was mapped with MIRI F770W at 12 pc scales. Thanks to the sensitivity and resolution of JWST, we detect dust emission out to ∼4 kpc from the disk, in the form of filaments, arcs, and super-bubbles. Some of these filaments can be traced back to regions with recent star formation activity, suggesting that feedback-driven galactic winds play an important role in regulating baryonic cycling. The presence of dust at these altitudes raises questions about the transport mechanisms at play and suggests that small dust grains are able to survive for several tens of million years after having been ejected by galactic winds in the disk-halo interface. We lay out several scenarios that could explain this emission: dust grains may be shielded in the outer layers of cool dense clouds expelled from the galaxy disk, and/or the emission comes from the mixing layers around these cool clumps where material from the hot gas is able to cool down and mix with these cool cloudlets. This first set of data and upcoming spectroscopy will be very helpful to understand the survival of dust grains in energetic environments, and their contribution to recycling baryonic material in the mid-plane of galaxies.Peer reviewe
The genome sequence of Tadarida brasiliensis I. Geoffroy Saint-Hilaire, 1824 [Molossidae; Tadarida]
Get PDFFunding: SCV was supported by a UKRI Future Leaders Fellowship, (MR/T021985/1), an ERC Consolidator Grant (101001702; BATSPEAK), and a Max Planck Research Group awarded by the Max Planck Society. ECT is a Wellcome collaborator and the Irish Research Council Laureate Award IRCLA/2017/58 and Science Foundation Ireland Future Frontiers 19/FFP/6790. MS and CW were supported by the US Office of Naval Research (ONRN00014-17-1–2736).We present a genome assembly from an individual male Tadarida brasiliensis (The Brazilian free-tailed bat; Chordata; Mammalia; Chiroptera; Molossidae). The genome sequence is 2.28 Gb in span. The majority of the assembly is scaffolded into 25 chromosomal pseudomolecules, with the X and Y sex chromosomes assembled.Peer reviewe
Compatibility assessment of unactivated internal alkynes in rhodium-catalyzed [2+2+2] cycloadditions
Get PDFFunding: J.M.H.-M. thanks the EaSI-CAT Centre for Doctoral Training for a PhD Studentship. A.J.B.W. thanks the Leverhulme Trust for a Research Fellowship (RF 2022-014) and the EPSRC Programme Grant ‘Boron: Beyond the Reagent’ (EP/W0077517/1) for support.Functionalized 1,2,4,5-tetrasubstituted benzenes are synthetically difficult or laborious to access. The Rh-catalyzed [2+2+2] cycloaddition of a diyne and internal alkyne offers a seemingly straightforward route to these scaffolds; however, this has been largely restricted to alkynes bearing activating (coordinating) functional groups, with very few examples of unactivated alkynes. In this work, we disclose an assessment of Rh-catalyzed [2+2+2] cycloadditions employing unactivated internal alkynes, focusing on the structural diversity and compatibility of both alkyne and diyne components. The limitations of this method are disclosed, with exceptionally bulky alkynes and specific functional groups undergoing side reactions. Furthermore, the practicalities of gram-scale reactions and catalyst recovery/reuse are demonstrated.Peer reviewe
Eddy-driven zonal jet flows in the laboratory
Get PDFFunding: JA thanks the NSF Geophysics Program for support via award EAR #2143939. DL acknowledges support from The Carnegie Trust via Research Incentive Grant RIG012674, and the Royal Society via Research Grant RG/R1/241426. YA is supported by the NSERC grant RGPIN 2019-04957 and PLR acknowledges support from UKRI/EPSRC grant EP/W022087/1.Zonal jets are a ubiquitous feature of the circulation of planetary atmospheres, oceans and interiors. Many of the dynamical mechanisms that lead to the formation and evolution of such jets can be reproduced and studied in laboratory experiments, which have proved to be important sources of insight for understanding the nature of planetary jets. Here we introduce some of the key concepts underlying the production and maintenance of patterns of zonal jets in rotating and/or stratified flows. We then review a broad range of laboratory experiments that have helped to test and verify many of the dynamical mechanisms proposed to interpret geophysical jets involving the interaction of eddies and zonal flows. Laboratory experiments continue to have an important role to play in elucidating a quantitative understanding of zonal jets and their interactions with other aspects of planetary circulation systems.Peer reviewe
LeeLee : an attention visualisation analysis while reading academically
Get PDFUnderstanding attention during academic reading is fundamental in the context of Human-Computer Interaction (HCI). Attention is a limited, yet essential resource that is crucial for processing academic texts and performing focused reading tasks. In a hyper-connected society, distractions from digital devices adversely influence specific academic reading patterns, such as sustained attention and comprehension, making it challenging to maintain focus. This study explores and addresses the need for attention in academic reading. With the increasing use of digital academic reading platforms such as e-readers, tablets, and computer screens, it is essential to understand how these environments impact attention. A major finding of this thesis is that attention while reading academically can be decoded and analysed through visualisations, thus revealing patterns of fixations, saccades, and cognitive engagement levels that inform strategies to enhance focus and efficiency. The key results show that both Eye-tracking and EEG can provide quantifiable data on attentional patterns during reading. The study used the "Visualization as Intermediate Representations (VLAIR) technique to interpret these data. Eyetracking data revealed specific patterns of fixations, interest, and cognitive effort, while EEG data provided insights into levels of cognitive engagement through alpha and beta wave activity. Combining these methods facilitated a detailed analysis of reading behaviour, including eye movement patterns and cognitive load. The findings of this research offer practical implications for the design of digital learning platforms and interactive reading environments. By understanding and visualising attention patterns, educators and technologists could develop better strategies and tools to support focused academic reading, ultimately enhancing learning outcomes
Testing phylogenetic signal with categorical traits and tree uncertainty
Get PDFFunding: This work was supported by the Austrian Science Fund [P34524-B] to R.B.; partially supported by Centre of Mathematics of the University of Porto - Intelligent Systems Associate Laboratory (CMUP-LASI) through the Fundação para a Ciência e a Tecnologia (FCT) project [UIDB/00144/2020] to A.P.R.; and the FCT projects UIDB/04423/2020, UIDP/04423/2020, PTDC/CTA-AMB/31774/2017 [POCI-01-0145-FEDER/031774/2017], and Atlantida [NORTE-01-0145-FEDER-000040] to A.A.The phylogenetic signal, frequently used to identify signatures of adaptive evolution or important associations between genes and phenotypes, measures the tendency for recently diverged species to resemble each other more than distantly related species. An example of such a measure is the δ statistic, which uses Shannon entropy to measure the degree of phylogenetic signal between a categorical trait and a phylogeny. In this study, we refined this statistic to account for tree uncertainty, resulting in more accurate assessments of phylogenetic associations. In addition, we provided a more accessible and computationally efficient implementation of the δ statistic that will facilitate its use by the evolutionary community.Peer reviewe
A multi-resonant thermally activated delayed fluorescence emitter with a twisted second-generation carbazole dendron showing suppressed concentration quenching and its use in solution-processed organic light-emitting diodes
Get PDFFunding: Jingxiang Wang thanks the China Scholarship Council (202006250026). This work was additionally funded by the EPSRC through grant numbers EP/R00188X/1, EP/W007517/1, and EP/W015137/1, the JSPS KAKENHI Grant No. JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”), the JSPS Core-to-Core Program (Grant No: JPJSCCA20220004), and the International Collaborative Research Program of Institute for Chemical Research, Kyoto University (Grant No. 2023-42, 2024-38). This project has been partly funded by the European Union Horizon Europe research and innovation programme under grant agreement no. 101073045 (TADFsolutions) and the EPSRC grant EP/X026175/1. Single crystal X-ray diffraction data for 2,7-tBuCzNB were collected remotely at beam line I-19 of Diamond Light Source (award CY30280).Multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters have drawn significant interest for use in organic lighting-emitting diodes (OLEDs) as they typically have bright and narrowband emission. However, their rigid, planar structures result in poor solubility in organic solvents and a tendency to aggregate. This usually results in severe aggregation-caused quenching (ACQ), which hinders in particular, their application in solution-processed OLEDs. Herein, a solution-processable MR-TADF emitter 2,7-tBuCzNB has been designed, synthesized and studied. The presence of eight tert-butyl groups and the use of second-generation donor dendrons help enhance its solubility and suppress the ACQ. 2,7-tBuCzNB exhibits narrowband green emission at 493 nm, with a full-width at half maximum of 32 nm and a high photoluminescence quantum yield (ΦPL) of 93% in toluene. The ΦPL values in 1–10 wt% doped films in mCP are slightly lower but still reach up to 80%. Solution-processed OLEDs using this emitter showed maximum external quantum efficiencies (EQEmax) of 11.4 and 10.6% at 5 and 10 wt% doping concentration, respectively. This work demonstrates a strategy to synthesize solution processable MR-TADF emitters for use in solution-processed OLEDs.Peer reviewe
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