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Ocean soundscapes and trends from 2003 to 2021 : 10-100 Hz
Get PDFFunding: The National Physical Laboratory authors acknowledge the funding of the UK Department for Science, Innovation and Technology through the National Measurement System. P.L.T. was supported by the Office of Naval Research (Grant Nos. N000142012697 and N000142112096) and the Strategic Environmental Research and Development Program (Grant Nos. RC20-1097, RC20-7188, and RC21-3091).We analyze ocean ambient sound from a global network of hydrophones installed and maintained by the Comprehensive Nuclear-Test-Ban Treaty Organization. We process acoustic data from nine hydrophones across six hydroacoustic stations distributed across five oceans: North Pacific, South Pacific, South Atlantic, Indian, and Southern oceans, for up to 19 consecutive years between 2003 and 2021. We identify dominant natural and anthropogenic sources for all six stations and observe long-term trends at four of them. Out of 20 statistical tests, 15 identified a significant downward trend in sound pressure level. Possible causes of these decreasing trends include a global recession in 2016, the COVID-19 pandemic in 2020, five major earthquakes between 2004 and 2012 (with none in 2013-2021), and a steadily increasing sea surface temperature, which decreases the sea surface critical angle and hence the contribution from near-surface sources (e.g., shipping) to sound pressure level.Peer reviewe
Echo mapping of the black hole accretion flow in NGC 7469
Get PDFFunding: R. Prince is grateful for a visiting fellowship funded by the Scottish Universities Physics Alliance (SUPA). The project is partially supported by the Polish Funding Agency National Science Centre, project 2017/26/A/ST9/-00756 (MAESTRO 9) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 951549) and BHU IoE scheme. HL acknowledges a Daphne Jackson Fellowship sponsored by the Science and Technology Facilities Council (STFC), UK.Reverberation mapping (RM) can measure black hole accretion disc sizes and radial structure through observable light travel time lags that should increase with wavelength as τ ∝ λ4/3 due to the disc’s T ∝ r−3/4 temperature profile. Our 250-d RM campaign on NGC 7469 combines sub-day cadence 7-band photometry from the Las Cumbres Observatory robotic telescopes and weekly X-ray and UVOT data from Swift. By fitting these light curves, we measure the spectral energy distribution (SED) of the variable accretion disc, and inter-band lags of just 1.5 d across the UV to optical range. The disc SED is close to the expected fν ∝ ν1/3, and the lags are consistent with τ ∝ λ4/3, but three times larger than expected. We consider several possible modifications to standard disc assumptions. First, for a 9 × 106 M☉ black hole and two possible spins a* = (0, 1), we fit the X-ray-ultraviolet (UV)-optical SED with a compact relativistic corona at height Hx ∼ (46, 27) Rg irradiating a flat disc with accretion rate ṁEdd ∼ (0.23, 0.24) inclined to the line of sight by i < 20°. To fit the lags as well as the SED, this model requires a low spin a* ≈ 0 and boosts disc colour temperatures by a factor fcol ≈ 1.8, which shifts reprocessed light to shorter wavelengths. Our Bowl model with fcol = 1 neglects relativity near the black hole, but fits the UV-optical lags and SEDs using a flat disc with ṁEdd < 0.06 and a steep outer rim at Rout/c ∼ 5 − 10 d with H/R < 1 per cent. This rim occurs near the 103K dust sublimation temperature in the disc atmosphere, supporting models that invoke dust opacity to thicken the disc and launch failed radiatively driven dusty outflows at the inner edge of the broad line region (BLR). Finally, the disc lags and SEDs exhibit a significant excess in the u and r bands, suggesting Balmer continuum and Hα emission, respectively, from the BLR.Peer reviewe
Parliamentary research services : mapping the territory
Get PDFThere is growing interest in the relationship between parliaments and research. Researchers are increasingly viewing parliaments as key sites for studying the use of evidence and achieving research impact. Meanwhile, parliamentary practitioners are beginning to call for improved evidence regarding science advice systems and processes. There is, however, a relative lack of information on how parliaments engage with research. There is even less information on how research services within parliaments operate. This article addresses these issues by reporting on the first stages of a project mapping and describing global parliamentary research services. Drawing on publicly available data gleaned from a rigorous mapping exercise alongside documentary and survey data, it makes two key contributions to this emerging field. First, in the absence of clear criteria for explaining or understanding the role and function of PRS, the article introduces a typology to categorize and compare these services. Second, recognizing that information on PRS is fragmented and difficult to obtain, especially for those working within these services, the article presents a global map of PRS. The map does not claim to provide a definitive picture of PRS but is a resource for facilitating further analysis of what PRS are and do, enabling PRS to connect with and learn from each other.Peer reviewe
Climate-driven warming disrupts the symbiosis of bobtail squid Euprymna scolopes and the luminous bacterium Vibrio fischeri
Get PDFFunding: This work was supported by FCT—Fundação para a Ciência e Tecnologia, I.P., within the PhD scholarship UI/BD/151019/2021 awarded to E.O., the strategic project UIDB/04292/2020 granted to MARE, and the project LA/P/0069/2020 granted to the Associate Laboratory ARNET. T.A.M. thanks partial support by CEAUL (funded by FCT, UIDB/00006/2020).Under the current climate crisis, marine heatwaves (MHW) are expected to intensify and become more frequent in the future, leading to adverse effects on marine life. Here, we aimed to investigate the impact of environmental warming on the symbiotic relationship between the Hawaiian bobtail squid (Euprymna scolopes) and the bioluminescent bacterium Vibrio fischeri. We exposed eggs of E. scolopes to three different temperatures during embryogenesis, namely: (i) 25°C (yearly average), (ii) 27°C (summer maximum) or (iii) 30°C (category IV MHW), followed by a colonisation assay under the same conditions. Decreased hatching success and reduced developmental time were observed across warmer conditions compared to 25°C. Moreover, exposure to the category IV MHW led to a significant decrease in survival after 48 h. With increasing temperature, bobtail squids required more bacteria in the surrounding seawater for successful colonisation. When colonised, the regression of the light organ's appendages was not dependent on temperature, but the opposite was found in non-colonised bobtail squids. Furthermore, the capacity for crypt 3 formation in the squid's light organ, which is crucial for enhancing resilience under stress, also declined with warming conditions. This study emphasises the critical need to study the dynamics of microbial symbiosis under the projected conditions for the ocean of tomorrow.Peer reviewe
Biochemical and biological characterisation of GH-J clan enzymes from haloarchaea
No full textFructans are fructose-based oligo- and polysaccharides that are exploited in a variety of industrial, agricultural, food and healthcare applications, most notably as prebiotic dietary supplements. Fructans are synthesised from sucrose by enzymes with fructosyltransferase activity from the glycoside hydrolase 32 and 68 (GH32 and GH68) families. Recently, the existence of GH32 and GH68 enzymes in archaea, specifically haloarchaea, has been demonstrated. The work presented in this thesis focuses on characterizing the structure, function and activity of GH32 and GH68 enzymes from two model haloarchaeal species: Haloarcula hispanica and Haloferax gibbonsii. GH32 and GH68 enzymes from these organisms were expressed in Haloferax volcanii and purified to apparent homogeneity. The three-dimensional structure of GH32 from H. gibbonsii was determined by X-ray crystallography, with analysis revealing the existence of a novel N-terminal domain that is postulated to be involved in levan binding. Extensive functional characterisation of the GH32 and GH68 enzymes was performed, which provided valuable insights into the range of activities and substrate specificities of the enzymes. To complement this biochemical and structural analysis, the biological function of the GH32 and GH68 proteins was addressed by creating single and double knockouts in H. hispanica, revealing that the genes are essential for cell survival when sucrose is present as the sole carbon source. Characterisation of the mechanisms of fructan biosynthesis by haloarchaea could shed light into underlying catalytic mechanisms, as well as the biological significance of fructan biosynthesis in haloarchaea. In addition, it could provide the potential to establish a haloarchaeal platform that could be deployed by industrial biotechnology to produce fructans of novel physiological properties, which could also infer advantages over traditional industrial processes."This work was supported by the EASTBIO Doctoral Training Partnership with funding from the UKRI Biotechnology and Biological Sciences Research Council."--Fundin
Endomorphisms and partial isomorphisms
Get PDFLet A be an algebra (in the sense of universal algebra). Define PISo(A) to be the inverse semigroup of partial isomorphisms of A, and End(A) the semigroup of endomorphisms of A. The purpose of this note is to record the following result. Theorem 1 Let A be a finite abelian group. Then |PIso(A)| = |End(A)|.Peer reviewe
Elevating the optical nonlinearity : design, synthesis, and properties of a mixed-ligand zinc(II) metal–organic framework
Get PDFFunding: This work was supported by University of Maragheh, Iran’s National Elites Foundation and Iran National Science Foundation (project number: 4037973); the authors are also grateful for the financial support. AMK acknowledges the FCT, Portugal (projects PTDC/QUI-QIN/3898/2020, UIDB/00100/2020, and LA/P/0056/2020).The molecular design of new compounds with enhanced third-order nonlinear optical (NLO) applications is an important research topic in the area of functional materials. The present study describes a new 3D metal–organic framework [Zn3(μ3-bta)2(μ4-ata)2]n (abbreviated as NH2–Zn-MUM-6), generated solvothermally from a multicomponent system composed of zinc(II) ions and 2-aminoterephthalic acid (H2ata) and 1H-benzotriazole (Hbta) as linkers. Apart from an intricate porous structure with a seh-4,6-Imma topology, this MOF features good thermal stability and exceptional NLO characteristics. These were investigated in detail by a Z-scan method, revealing the remarkably high values of third-order nonlinear refractive index (n2 = 30.83 × 10–8 cm2/W) and nonlinear absorption coefficient (β = 4.06 × 10–4 cm/W). An extended π-conjugation in both aromatic ligands, μ3-bta– and μ4-ata2–, and their interaction with Zn centers contribute to the formation of a highly polarizable system, thus significantly enhancing its capacity for NLO behavior. This study broadens the family of nonlinear optical materials and provides insights into the relationship between the structure and properties of amino-functionalized mixed-linker MOFs from the viewpoint of optical applications such as all-optical switching and data transmission.Peer reviewe
Investigating the support of visualization creation activities with children
No full textVisualization is now seen ubiquitously in everyday life, and is used by a variety of people. As such, ensuring that visualization practices are democratised so that even novices can access visualization tools has become an active area of research. However, while the basic skills which are used to create visualizations are taught from Primary School, little research exists on how to support children in visualization practices. This thesis starts to explore this area by addressing how we can create visualization tools which support Primary School children in visualization creation activities.
To explore the creation of visualization tools for children I investigate the use of the Constructive Visualization paradigm. This paradigm, which has been productive with adult visualization novices, aims to provide simple, expressive, and dynamic tools. I investigate providing such tools to children through physical and digital modalities.
The use of physical objects in Primary School education, and their proven utility with adult novices, make them a productive method to explore children’s visualization processes. I therefore contribute the design of a physical token set to support children in visualization activities. Using this token set I conducted two studies, in out-of-school clubs and a local Primary School, exploring children’s use of the tools and their visualization processes.
Following from these studies I present a set of learning objectives and design principles which can inform the design of digital visualization tools for children. Guided by these principles I designed a digital visualization tool for Primary School children: Construct-A-Vis. I conducted a study using Construct-A-Vis in a local Primary School to explore how children respond to digital visualization tools which support the free-form exploration of a variety of visual mappings.
Children showed a critical engagement in their visualization creation tasks, suggesting that Constructive Visualization can support children in visualization activities
Implications of low temporal resolution of vessel tracking systems
Get PDFM.M.R. has a DL57 contract (junior researcher) awarded by IPMA within the project “Small scale fisheries and harvest monitoring program” (MOPPA) funded by the Fisheries Operational Programme (MAR-014.7.2-FEAMPA-0005) and by Map-SSF EEA/BHR/24/001–Assessing small-scale fishing activity and pressure on Europe's marine ecosystems.Spatial and temporal fishing effort (FE) estimates are crucial for informing scientific-based decisions in fisheries management, spatial planning, and conservation. Lower temporal resolution (longer intervals between vessel position registrations) reduces FE accuracy, thus calling for a balance between precision and feasibility for large-scale mapping, such as in European waters. Effective marine management is critically dependent on this kind of accurate, comprehensive, and appropriate data. New EU legislation mandates tracking all fishing vessels, including small-scale fisheries (SSF) (LOA ≤ 12 m), implying a reassessment of optimal polling intervals. While experts recommend high-frequency polling (1 poll/30 s) for SSF, large-scale fisheries (LSF) have been mapped with up to 2-h polling intervals. Here, our study evaluates how polling frequency affects fishing activity characterization and FE estimation across fleets. We found that low temporal resolution critically affects (1) FE by underestimation, (2) misclassification of fishing behaviour, (3) compliance challenges, (4) marine spatial planning conflicts, (5) seafloor impact assessment (6) inaccurate bycatch risk analysis, (7) geographic projection biases, and (8) CPUE-based abundance indices, affecting stock and mortality estimates. These results highlight a central problem: low-resolution tracking compromises the scientific and management of outputs. The promise of high-resolution tracking to improve accuracy, is affected by the trade-offs between cost and data processing capacity, and the burden on vessel operators. Thus, SSF and passive gears should be tracked with at least a 30-s polling frequency as a conservative approach. For LSF using active gears, further work is required to determine the optimal ping frequency, but overall, it should be on the scale of a few minutes, depending on the gear used. To address this, our work clearly supports a recommendation for future regulations to define minimum acceptable polling intervals, tailored by fleet segment, and that support mechanisms be implemented to ease adoption. These regulatory aspects should contemplate a close collaboration with the fishing industry to ensure practicality, compliance, and long-term success. Thus, our findings highlight the costs of low-resolution tracking, providing critical insights for decision-makers shaping future vessel monitoring policies.Peer reviewe
The V5-epitope tag for cell engineering and its use in immunohistochemistry and quantitative flow cytometry
Get PDFFunding: The study was supported by the National Centre for the 3Rs (NC3Rs) via CRACK IT Challenge 32 [NC/C01905/1 & NC/C019202/1].Synthetic biology has fundamentally advanced cell engineering and helped to develop effective therapeutics such as chimeric antigen receptor (CAR)-T cells. For these applications, the detection, localization, and quantification of heterologous fusion proteins assembled from interchangeable building blocks is of high importance. The V5 tag, a 14-residue epitope tag, offers promising characteristics for these applications but has only rarely been used in this context. Thus, we have systematically evaluated the murine anti-V5 tag antibody mu_SV5-Pk1 as well as its humanized version, hu_SV5-Pk1, to analyze cells expressing V5-tagged receptors in samples from various in vitro and in vivo experiments. We found that the V5 tag signal on cells is affected by certain fixation and detachment reagents. Immunohistochemistry (IHC) on formalin-fixed paraffin-embedded (FFPE) mouse tissue samples was performed to sensitively detect cells in tissue. We improved IHC by applying the hu_SV5-Pk1 monoclonal antibody (mAb) to avoid cross-reactivity within and unspecific background signals arising on fixed mouse tissue. Conversely, the absence of unspecific binding by the mu_SV5-Pk1 mAb was evaluated on 46 human normal or cancer tissues. Our findings present a robust toolbox for utilizing the V5 tag and cognate antibodies in synthetic biology applications.Peer reviewe
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