Showing papers by "University of St Andrews published in 2022"
TL;DR: In this paper, the authors studied the invariance of various graphs whose vertex set is a group and whose edges reflect group structure in some way (so that, in particular, they are invariant under the action of the automorphism group of $G$).
Abstract: This paper concerns aspects of various graphs whose vertex set is a group $G$ and whose edges reflect group structure in some way (so that, in particular, they are invariant under the action of the automorphism group of $G$). The particular graphs I will chiefly discuss are the power graph, enhanced power graph, deep commuting graph, commuting graph, and non-generating graph.My main concern is not with properties of these graphs individually, but rather with comparisons between them. The graphs mentioned, together with the null and complete graphs, form a hierarchy (as long as $G$ is non-abelian), in the sense that the edge set of any one is contained in that of the next; interesting questions involve when two graphs in the hierarchy are equal, or what properties the difference between them has. I also consider various properties such as universality and forbidden subgraphs,comparing how these properties play out in the different graphs.I have also included some results on intersection graphs of subgroups of various types, which are often in a ''dual'' relation to one of the other graphs considered. Another actor is the Gruenberg--Kegel graph, or prime graph, of a group: this very small graph has a surprising influence over various graphs defined on the group.Other graphs which have been proposed, such as the nilpotence, solvability, and Engel graphs, will be touched on rather more briefly. My emphasis is on finite groups but there is a short section on results for infinite groups. There are briefer discussions of general $Aut(G)$-invariant graphs, and structures other than groups (such as semigroups and rings).Proofs, or proof sketches, of known results have been included where possible. Also, many open questions are stated, in the hope of stimulating further investigation.
40 citations
01 Jan 2022
TL;DR: In this paper , a new multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter was presented, demonstrating that the structure need not require the presence of acceptor atoms.
Abstract: We present a new multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter paradigm, demonstrating that the structure need not require the presence of acceptor atoms.
27 citations
TL;DR: In this paper , aza-triangulene was synthesized on the Au (111) and Ag(111) surfaces, along with their characterizations by scanning microscopy and spectroscopy in combination with density functional theory (DFT) calculations.
Abstract: Nitrogen heteroatom doping into a triangulene molecule allows tuning its magnetic state. However, the synthesis of the nitrogen-doped triangulene (aza-triangulene) has been challenging. Herein, we report the successful synthesis of aza-triangulene on the Au(111) and Ag(111) surfaces, along with their characterizations by scanning tunneling microscopy and spectroscopy in combination with density functional theory (DFT) calculations. Aza-triangulenes were obtained by reducing ketone-substituted precursors. Exposure to atomic hydrogen followed by thermal annealing and, when necessary, manipulations with the scanning probe afforded the target product. We demonstrate that on Au(111), aza-triangulene donates an electron to the substrate and exhibits an open-shell triplet ground state. This is derived from the different Kondo resonances of the final aza-triangulene product and a series of intermediates on Au(111). Experimentally mapped molecular orbitals match with DFT-calculated counterparts for a positively charged aza-triangulene. In contrast, aza-triangulene on Ag(111) receives an extra electron from the substrate and displays a closed-shell character. Our study reveals the electronic properties of aza-triangulene on different metal surfaces and offers an approach for the fabrication of new hydrocarbon structures, including reactive open-shell molecules.
23 citations
TL;DR: In this article, the authors set the foundations for wastewater-based epidemiology (WBE) in Portugal by monitoring the trends of SARS-CoV-2 RNA circulation in the community, on a nationwide perspective during different epidemiological phases of the pandemic.
23 citations
TL;DR: In this article, the authors explore Digital Passports as boundary objects that are useful in supporting collaboration, identifying points of miscommunication between key actors along the value chain, from misconceptions of health and safety regulations to a distinction between retailers' and manufacturing brands' willingness to invest in reuse.
18 citations
TL;DR: In this paper, a review of literature, fisheries databases, international and regional agency reports, NGO and government reports and case studies from West and East Africa is presented, showing that despite a higher incidence of Illegal, Unreported and Unregulated (IUU) fishing in industrial fisheries than the SSF, fisheries governance mechanisms continue to advance the "Survival of the Richest" -the industrial sector, to the detriment of the 'Fittest' -the SSF.
17 citations
20 Jan 2022
TL;DR: In this paper , a structural disanalogies between spectrum arguments and sorites arguments are explored, inspired by Parfit's work on reductionism, and the other involves hypersensitivity.
Abstract: Ethics in the tradition of Derek Parfit’s Reasons and Persons is riddled with sorites-like arguments, which lead us by what seem innocent steps to seemingly false conclusions. Take, for example, spectrum arguments for the Repugnant Conclusion that appeal to slight differences in quality of life. Several authors have taken the view that, since spectrum arguments are structurally analogous to sorites arguments, the correct response to spectrum arguments is structurally analogous to the correct response to sorites arguments. This sorites analogy is here argued against. There are potential structural disanalogies between spectrum arguments and sorites arguments. But even if these arguments are relevantly structurally analogous, they differ in their content in ways that show the sorites analogy to be implausible. Two content-based disanalogies are here explored—one is inspired by Parfit’s work on reductionism, and the other involves hypersensitivity. The chapter concludes with a methodological lesson.
14 citations
TL;DR: In this paper , the spin-component scaling second-order approximate coupled-cluster (SCS-CC2) was used to predict the ΔEST (i.e., the energy difference between the lowest singlet S1 and triplet T1 excited states) of a large number of thermally activated delayed fluorescent (TADF) materials, with a mean average deviation (MAD) of 0.04 eV compared to experimental data.
Abstract: With the surge of interest in multiresonant thermally activated delayed fluorescent (MR-TADF) materials, it is important that there exist computational methods to accurately model their excited states. Here, building on our previous work, we demonstrate how the spin-component scaling second-order approximate coupled-cluster (SCS-CC2), a wavefunction-based method, is robust at predicting the ΔEST (i.e., the energy difference between the lowest singlet S1 and triplet T1 excited states) of a large number of MR-TADF materials, with a mean average deviation (MAD) of 0.04 eV compared to experimental data. Time-dependent density functional theory calculations with the most common DFT functionals as well as the consideration of the Tamm-Dancoff approximation (TDA) consistently predict a much larger ΔEST as a result of a poorer account of Coulomb correlation as compared to SCS-CC2. Very interestingly, the use of a metric to assess the importance of higher order excitations in the SCS-CC2 wavefunctions shows that Coulomb correlation effects are substantially larger in the lowest singlet compared to the corresponding triplet and need to be accounted for a balanced description of the relevant electronic excited states. This is further highlighted with coupled cluster singles-only calculations, which predict very different S1 energies as compared to SCS-CC2 while T1 energies remain similar, leading to very large ΔEST, in complete disagreement with the experiments. We compared our SCS-CC2/cc-pVDZ with other wavefunction approaches, namely, CC2/cc-pVDZ and SOS-CC2/cc-pVDZ leading to similar performances. Using SCS-CC2, we investigate the excited-state properties of MR-TADF emitters showcasing large ΔET2T1 for the majority of emitters, while π-electron extension emerges as the best strategy to minimize ΔEST. We also employed SCS-CC2 to evaluate donor-acceptor systems that contain a MR-TADF moiety acting as the acceptor and show that the broad emission observed for some of these compounds arises from the solvent-promoted stabilization of a higher-lying charge-transfer singlet state (S2). This work highlights the importance of using wavefunction methods in relation to MR-TADF emitter design and associated photophysics.
14 citations
TL;DR: In this article , the authors outline challenges for biodiversity monitoring using citizen science data in four partially overlapping categories: challenges that arise as a result of observer behaviour, data structures, statistical models, and communication.
Abstract: There is increasing availability and use of unstructured and semi-structured citizen science data in biodiversity research and conservation. This expansion of a rich source of ‘big data’ has sparked numerous research directions, driving the development of analytical approaches that account for the complex observation processes in these datasets. We review outstanding challenges in the analysis of citizen science data for biodiversity monitoring. For many of these challenges, the potential impact on ecological inference is unknown. Further research can document the impact and explore ways to address it. In addition to outlining research directions, describing these challenges may be useful in considering the design of future citizen science projects or additions to existing projects. We outline challenges for biodiversity monitoring using citizen science data in four partially overlapping categories: challenges that arise as a result of (a) observer behaviour; (b) data structures; (c) statistical models; and (d) communication. Potential solutions for these challenges are combinations of: (a) collecting additional data or metadata; (b) analytically combining different datasets; and (c) developing or refining statistical models. While there has been important progress to develop methods that tackle most of these challenges, there remain substantial gains in biodiversity monitoring and subsequent conservation actions that we believe will be possible by further research and development in these areas. The degree of challenge and opportunity that each of these presents varies substantially across different datasets, taxa and ecological questions. In some cases, a route forward to address these challenges is clear, while in other cases there is more scope for exploration and creativity.
14 citations
01 Jan 2022-Journal of Materials Chemistry C. Materials for Optical, Magnetic and Electronic Devices
TL;DR: In this article , blue-emitting thermally activated delayed fluorescence (TADF) compounds derived from 2CzPN have been successfully developed, which display novel electrochemiluminescence properties.
Abstract: We have successfully developed blue-emitting thermally activated delayed fluorescence (TADF) compounds derived from 2CzPN. They display novel electrochemiluminescence properties, these revealing correlations with measured Δ E ST values.
14 citations
01 Jan 2022
TL;DR: In this article, a model is presented based on IoT devices that can sense and predict the pre-accident/pre-collision state and generates an alarm message about the collision is going to occur.
Abstract: In the recent scenario, there is a drastic improvement in transportation, infrastructure, and communication technology which increases the number of commercial as well as non-commercial vehicles. Therefore, there is also an increase in the number of accident incidence. This ultimately results in a high death rate due to a road accident. More than half of accident incidence results in death due to delayed medical aid to the victim. If medical aid or services received at the proper time, then the victim may survive. With the application of machine learning processes and communication advancements, there is scope for the development of a more accurate system. In this chapter, a model is presented based on IoT devices that can sense and predict the pre-accident/pre-collision state and generates an alarm message about the collision is going to occur. This model is designed to extracts image/video features to determine the possibility of occurrence of a collision. This model is also efficient for post-collision.
TL;DR: In this article , the authors present a review of the pitfalls of using Hidden Markov Models (HMMs) to solve ecological problems and highlight potential research opportunities to solve these pitfalls.
Abstract: Hidden Markov models (HMMs) and their extensions are attractive methods for analysing ecological data where noisy, multivariate measurements are made of a hidden, ecological process, and where this hidden process is represented by a sequence of discrete states. Yet, as these models become more complex and challenging to understand, it is important to consider what pitfalls these methods have and what opportunities there are for future research to address these pitfalls. In this paper, we review five lesser known pitfalls one can encounter when using HMMs or their extensions to solve ecological problems: (a) violation of the snapshot property in continuous-time HMMs; (b) biased inference from hierarchical HMMs when applied to temporally misaligned processes; (c) sensitive inference from using random effects to partially pool across heterogeneous individuals; (d) computational burden when using HMMs to approximate models with continuous state spaces; and (e) difficulty linking the hidden process to space or environment. This review is for ecologists and ecological statisticians familiar with HMMs, but who may be less aware of the problems that arise in more specialised applications. We demonstrate how each pitfall arises, by simulation or example, and discuss why this pitfall is important to consider. Along with identifying the problems, we highlight potential research opportunities and offer ideas that may help alleviate these pitfalls. Each of the methods we review are solutions to current ecological research problems. We intend for this paper to heighten awareness of the pitfalls ecologists may encounter when applying these more advanced methods, but we also hope that by highlighting future research opportunities, we can inspire ecological statisticians to weaken these pitfalls and provide improved methods.
TL;DR: In this article, a solid oxide fuel cell utilizing bio-fuels such as methanol and ethanol could provide a carbon-neutral electricity generation and facilitate its applications in transport or stationary power unit.
TL;DR: In this article, the authors find a distinct and robust positive impact of carbon intensity (carbon emissions per unit of output) on CoE: on average, a standard deviation higher (sector-adjusted) carbon intensity is associated with a CoE premium of 6 (9) basis points or 1.7% (2.6%).
Abstract: he transition from high- to lower-carbon production systems increasingly creates regulatory and market risks for high-emitting firms. We test to what extent equity market investors demand a premium to compensate for such risks and thus might raise firms' cost of equity capital (CoE). Using data for 1,897 firms spanning 50 countries over the years 2008–2016, we find a distinct and robust positive impact of carbon intensity (carbon emissions per unit of output) on CoE: On average, a standard deviation higher (sector-adjusted) carbon intensity is associated with a CoE premium of 6 (9) basis points or 1.7% (2.6%). This effect is primarily explained by systematic risk factors: high-emitting assets are significantly more sensitive to economy-wide fluctuations than low-emitting ones. The CoE impact of carbon intensity is more pronounced in high-emitting sectors, EU countries, and firms subject to carbon pricing regulation. Our results suggest that carbon emission reduction might serve as a valuable risk mitigation strategy.
TL;DR: In this article, the influence of zeolite framework nature on the separation of CO2/CH4, for CHA system containing variable isomorphously substituted heteroelements (none, B, Al, Ga, and Ti).
TL;DR: In this article, a set of 13 groundmass K-Ar ages on lava flows and one radiocarbon age on a charcoal from a strombolian deposit were used to reassess the volcano-tectonic evolution of Anjouan Island.
TL;DR: Learner autonomy is a vibrant and diverse field as mentioned in this paper , which has drawn liberally on theoretical constructs and research methodologies from other disciplines, and has contributed to the field of applied linguistics by drawing attention to the fundamental importance of understanding the language learner as an active agent in the learning process.
Abstract: Learner autonomy is a vibrant and diverse field. In its approximately 40-year history, it has drawn liberally on theoretical constructs and research methodologies from other disciplines. In turn, it has contributed to the field of applied linguistics by drawing attention to the fundamental importance of understanding the language learner as an active agent in the learning process. To understand the role of autonomy in, and its connections with other areas of study, it is important to ask how it has been conceptualized and operationalized. In addition, given its elusive and amorphous nature, it is timely to ask if and how (the development of) learner autonomy has been evaluated. In this article we conducted a scoping review, or a systematic and comprehensive literature review, of 61 empirical studies in this field. The results show a rich array of conceptualizations and numerous operationalizations, in addition to a somewhat limited use of evaluations. We draw from this a number of implications for research. In particular, we encourage learner autonomy researchers to make explicit their theoretical frameworks, extend their investigation to the role of language learning beyond the classroom in promoting learner autonomy, and diversify their use of research methods.
TL;DR: In this article , the authors show that the effective radiative forcing from absorbing aerosol varies strongly depending on their location, driven by rapid adjustments of clouds and circulation, and highlight the importance of this "aerosol pattern effect" for transient forcing from regional biomass-burning aerosol.
Abstract: Abstract Over the coming decades, it is expected that the spatial pattern of anthropogenic aerosol will change dramatically and the global aerosol composition will become relatively more absorbing. Yet, the climatic impact of this evolving spatial pattern of absorbing aerosol has received relatively little attention, in particular its impact on global-mean effective radiative forcing. Here, using model experiments, we show that the effective radiative forcing from absorbing aerosol varies strongly depending on their location, driven by rapid adjustments of clouds and circulation. Our experiments generate positive effective radiative forcing in response to aerosol absorption throughout the midlatitudes and most of the tropical regions, and a strong ‘hot spot’ of negative effective radiative forcing in response to aerosol absorption over the tropical Western Pacific. Further, these diverse responses can be robustly attributed to changes in atmospheric dynamics and highlight the importance of this ‘aerosol pattern effect’ for transient forcing from regional biomass-burning aerosol.
TL;DR: In this paper, the authors argue that a recognition of relationality and (inter)dependence as basic conditions of existence, and as basis for ethical reasoning in everyday engagements with energy in transition, is key to reflecting ways of relating to energy ethicalities in the everyday.
Abstract: Social science energy research is asking important questions about the social, political, and economic implications of energy transitions, and the consequent changing roles and relationships in the energy system. This has given rise to ethically driven research agendas, with an increasing focus on the need to better understand how people relate in their daily lives, both to mundane dilemmas around energy use, and to bigger questions around energy systems and energy system change. Based on insights from empirical Q-methodological research in Denmark and the UK, this article illustrates relational understandings of energy systems and a language of dependence, necessity and needs as important elements in how people make sense of the energy transition and their place in it. This challenges dominant frameworks and discourses of energy and energy transitions rooted in individualism and a language of individual responsibility, rational choice and/or individual rights and justice. In this article, we argue that a recognition of relationality and (inter)dependence as basic conditions of existence, and as basis for ethical reasoning in everyday engagements with energy in transition, is key to reflecting ways of relating to energy ethicalities in the everyday. This speaks strongly to recent advances of relational theories of energy systems and transitions, but calls for a recognition not only of inter-connections and relations, but of their ethical significance. To this end, we engage a feminist theory of care and care ethics in a proposition to ‘think energy with care’.
TL;DR: In this article , the authors explore what mobbing is, how it is used, what its functions are, and its use as a proxy for cognition, before providing suggestions for specific future avenues of research to improve our understanding of the ecology and evolution of mobbing.
Abstract: Mobbing is an important anti-predator behavior where prey harass and attack a predator to lower the immediate and long-term risk posed by it, warn others, and communicate about the predator's threat. While this behavior has been of interest to humans since antiquity, and aspects of mobbing have been well researched for the past 50 years, we still know little about its ecology and the evolutionary pressures that gave rise to this widespread anti-predator behavior. In this review, we explore what mobbing is, how it is used, what its functions are thought to be, and its use as a proxy for cognition, before providing suggestions for specific future avenues of research to improve our understanding of the ecology and evolution of mobbing.
TL;DR: In this paper , a meta-review of systematic literature reviews in higher education is presented, with the aim of providing a state-of-the-art systematic literature review methodologies in the field of higher education.
TL;DR: The authors showed that consumption of cinnamaldehyde significantly down-regulates transcriptional pathways connected to inflammation in the small intestine, and alters T-cell populations in mesenteric lymph nodes.
Abstract: Phytonutrients such as cinnamaldehyde (CA) have been studied for their effects on metabolic diseases, but their influence on mucosal inflammation and immunity to enteric infection are not well documented. Here, we show that consumption of CA in mice significantly down-regulates transcriptional pathways connected to inflammation in the small intestine, and alters T-cell populations in mesenteric lymph nodes. During infection with the enteric helminth Heligomosomoides polygyrus, CA treatment attenuated infection-induced changes in biological pathways connected to cell cycle and mitotic activity, and tended to reduce worm burdens. Mechanistically, CA did not appear to exert activity through a prebiotic effect, as CA treatment did not significantly change the composition of the gut microbiota. Instead, in vitro experiments showed that CA directly induced xenobiotic metabolizing pathways in intestinal epithelial cells and suppressed endotoxin-induced inflammatory responses in macrophages. Collectively, our results show that CA down-regulates inflammatory pathways in the intestinal mucosa and can limit the pathological response to enteric infection. These properties appear to be largely independent of the gut microbiota, and instead connected to the ability of CA to induce antioxidant pathways in intestinal cells. Our results encourage further investigation into the use of CA and related phytonutrients as functional food components to promote intestinal health in humans and animals.
TL;DR: Several theoretical perspectives were introduced to L2 research that aim to capture the contextual forces at work in teaching and learning, including but not limited to Activity Theory, Complexity Theory, and Sociocultural Theory as mentioned in this paper .
Abstract: “Context” has been increasingly featured and acknowledged in second language (L2) research because L2 teaching is recognised to be shaped by the environments in which it is situated. Numerous theoretical perspectives were introduced to L2 research that aim to capture the contextual forces at work in teaching and learning, including but not limited to Activity Theory, Complexity Theory, and Sociocultural Theory. Activity Theory holds that a learner's motives (human needs directed towards an object) are highly malleable, subject to the influence of such contextual variables as institutional rules, community, tools and artefacts available (see Leont'ev, 1978, 1981 who popularised Activity Theory from Sergei Rubenstein's founding and also Engeström's more current work in 1999). Complexity Theory, which has been widely adopted in both physical and social sciences, originates from physics (Martin et al., 2019). Complexity Theory was later introduced into L2 research by Diane Larsen-Freeman who posits that language learning is not only a process but a volatile and emerging system that is shaped by components of the system (e.g., learners, teachers, schools) engaging in constant and vibrant interactions (Larsen-Freeman, 2014). Sociocultural Theory highlights the sociocultural contexts where learning takes place (Lantolf, 2000; Vygotsky, 1978). Informed by a social constructivist view of learning, key concepts such as scaffolding (e.g., teachers’ support for learners) are put forward. In particular, Vygotsky argues that communication plays an indispensable role in language learning. Extrapolating Vygotsky's work to L2 research, Swain (2006) claims that languaging , dialogues among learners to discuss issues in L2 learning, is an important process of learning a L2.
TL;DR: In this paper , the role of Lateral Entorhinal cortex (LEC) in integrating information extends to long-term multimodal item-context associations, and it has been demonstrated that LEC has a role in integrating features of episodic memory prior to the hippocampus.
Abstract: Lateral entorhinal cortex (LEC) has been hypothesized to process nonspatial, item information that is combined with spatial information from medial entorhinal cortex to form episodic memories within the hippocampus. Recent studies, however, have demonstrated that LEC has a role in integrating features of episodic memory prior to the hippocampus. While the precise role of LEC is still unclear, anatomical studies show that LEC is ideally placed to be a hub integrating multisensory information. The current study tests whether the role of LEC in integrating information extends to long-term multimodal item-context associations. In Experiment 1, male rats were trained on a context-dependent odor discrimination task, where two different contexts served as the cue to the correct odor. Rats were pretrained on the task and then received either bilateral excitotoxic LEC or sham lesions. Following surgery, rats were tested on the previously learned odor-context associations. Control rats showed good memory for the previously learned association but rats with LEC lesions showed significantly impaired performance relative to both their own presurgery performance and to control rats. Experiment 2 went on to test whether impairments in Experiment 1 were the result of LEC lesions impairing either odor or context memory retention alone. Male rats were trained on simple odor and context discrimination tasks that did not require integration of features to solve. Following surgery, both LEC and control rats showed good memory for previously learned odors and contexts. These data show that LEC is critical for long-term odor-context associative memory.
TL;DR: In this article , the authors performed an extensive microscopy-based investigation of synapses and tripartite synapses in the spinal cord of ALS model mice and post-mortem human tissue from ALS cases.
Abstract: Abstract Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disorder. Separate lines of evidence suggest that synapses and astrocytes play a role in the pathological mechanisms underlying ALS. Given that astrocytes make specialised contacts with some synapses, called tripartite synapses, we hypothesise that tripartite synapses could act as the fulcrum of disease in ALS. To test this hypothesis, we have performed an extensive microscopy-based investigation of synapses and tripartite synapses in the spinal cord of ALS model mice and post-mortem human tissue from ALS cases. We reveal widescale synaptic changes at the early symptomatic stages of the SOD1 G93a mouse model. Super-resolution microscopy reveals that large complex postsynaptic structures are lost in ALS mice. Most surprisingly, tripartite synapses are selectively lost, while non-tripartite synapses remain in equal number to healthy controls. Finally, we also observe a similar selective loss of tripartite synapses in human post-mortem ALS spinal cords. From these data we conclude that tripartite synaptopathy is a key hallmark of ALS.
TL;DR: In this paper , the absolute electrochemiluminescence (ECL) quantum efficiencies of two iridium(III) complexes, fac-Ir(ppy)3 (Ir-1) and fac-Ivy(II)2(dtbubpy)]+ ([Ir-2]+) in annihilation and coreactant pathways were investigated by means of ECLvoltage curves, ECL-time curves and ECL spectroscopy.
Abstract: This work reports absolute electrochemiluminescence (ECL) quantum efficiencies (QEs) of two iridium(III) complexes, fac-Ir(ppy)3 (Ir-1) and [Ir(ppy)2(dtbubpy)]+ ([Ir-2]+) in annihilation and coreactant pathways. With potentiodynamic scans and potential pulsing, ECL mechanisms were investigated by means of ECL-voltage curves, ECL-time curves and ECL spectroscopy. It was demonstrated that the radical stability and reactivity are the two main factors affecting ECL efficiencies in various processes, while intermediate charges have little effect. Considering the difference of such radical behaviors between [Ru(bpy)3]2+ and other luminophores, absolute ECL QEs are more applicable compared with the ones relative to [Ru(bpy)3]2+ as a standard.
07 Mar 2022
TL;DR: In this article , a garlic-derived preparation (PTSO-PTS) containing two organosulfur metabolites, propylpropane thiosulfonate (pTSO) and propyl-propane-thiosulfinate (PSS), was investigated to regulate inflammatory responses in murine macrophages and intestinal epithelial cells.
Abstract: Scope: Garlic is a source of bioactive phytonutrients that may have anti-inflammatory or immunomodulatory properties. The mechanism(s) underlying the bioactivity of these compounds and their ability to regulate responses to enteric infections remains unclear. Methods and Results: This study investigates if a garlic-derived preparation (PTSO-PTS) containing two organosulfur metabolites, propyl-propane thiosulfonate (PTSO), and propyl-propane thiosulfinate (PTS), regulate inflammatory responses in murine macrophages and intestinal epithelial cells (IEC) in vitro, as well as in a model of enteric parasite-induced inflammation. PTSO-PTS decreases lipopolysaccharide-induced secretion of TNFα, IL-6, and IL-27 in macrophages. RNA-sequencing demonstrates that PTSO-PTS strongly suppresses pathways related to immune and inflammatory signaling. PTSO-PTS induces the expression of a number of genes involved in antioxidant responses in IEC during exposure to antigens from the parasite Trichuris muris. In vivo, PTSO-PTS does not affect T. muris establishment or intestinal T-cell responses but significantly alters cecal transcriptomic responses. Notably, a reduction in T. muris-induced expression of Tnf, Saa2, and Nos2 is observed. Conclusion: Garlic-derived organosulfur compounds exert anti-inflammatory effects in macrophages and IEC, and regulate gene expression during intestinal infection. These compounds and related organic molecules may thus hold potential as functional food components to improve gut health in humans and animals.
TL;DR: In this paper , the authors highlight that these offshore regions generally contain sedimentary organic matter (OM) of low reactivity, whereas inshore and coastal sediments store significant quantities of highly reactive OM that is at greater risk of remineralization when disturbed.
Abstract: Disturbance of marine sediments results in the remineralization of sedimentary organic matter (OM) and impacts upon natural burial processes. Management interventions which restrict or remove activities that cause seabed disturbance may offer effective strategies to protect the most vulnerable of these shelf sea OM stores, offering new opportunities to deliver climate mitigation actions. While the largest quantities of OM are often stored in the expansive offshore regions of continental shelves and might therefore suggest appropriate zones for management interventions to protect vulnerable OM stores, our results highlight that these offshore regions generally contain OM of low reactivity. Conversely, inshore and coastal sediments store significant quantities of highly reactive OM that is at greater risk of remineralization when disturbed. The marked spatial disparities between OM reactivity across shelf sea sedimentary environments highlights the need to focus emergent policy and future management interventions toward the protection of inshore and coastal sediments.
TL;DR: In this paper , the authors investigated whether two probiotic mixtures (comprised of Bacillus amyloliquefaciens, B. subtilis, and Enterococcus faecium [BBE], or Lactobacillus rhamnosus LGG and Bifidobacterium animalis subspecies Lactis Bb12 [LB]) could modulate helminth infection kinetics as well as the gut microbiome and intestinal immune responses in pigs infected with the nodular worm Oesophagostomum dentatum.
Abstract: Dietary probiotics may enhance gut health by directly competing with pathogenic agents and through immunostimulatory effects. These properties are recognized in the context of bacterial and viral pathogens, but less is known about interactions with eukaryotic pathogens such as parasitic worms (helminths). In this study we investigated whether two probiotic mixtures (comprised of Bacillus amyloliquefaciens, B. subtilis, and Enterococcus faecium [BBE], or Lactobacillus rhamnosus LGG and Bifidobacterium animalis subspecies Lactis Bb12 [LB]) could modulate helminth infection kinetics as well as the gut microbiome and intestinal immune responses in pigs infected with the nodular worm Oesophagostomum dentatum. We observed that neither probiotic mixture influenced helminth infection levels. BBE, and to a lesser extent LB, changed the alpha- and beta-diversity indices of the colon and fecal microbiota, notably including an enrichment of fecal Bifidobacterium spp. by BBE. However, these effects were muted by concurrent O. dentatum infection. BBE (but not LB) significantly attenuated the O. dentatum-induced upregulation of genes involved in type-2 inflammation and restored normal lymphocyte ratios in the ileo-caecal lymph nodes that were altered by infection. Moreover, inflammatory cytokine release from blood mononuclear cells and intestinal lymphocytes was diminished by BBE. Collectively, our data suggest that selected probiotic mixtures can play a role in maintaining immune homeostasis during type 2-biased inflammation. In addition, potentially beneficial changes in the microbiome induced by dietary probiotics may be counteracted by helminths, highlighting the complex inter-relationships that potentially exist between probiotic bacteria and intestinal parasites.
TL;DR: In this article , the authors combined bathymetric, atmospheric, and oceanographic data with a buoyant plume model to show that summer subglacial discharge from 136 tidewater glaciers, amounting to 0.02 Sv of freshwater, drives 0.6-1.6 Sv of upwelling.
Abstract: Greenland’s glacial fjords are a key bottleneck in the earth system, regulating exchange of heat, freshwater and nutrients between the ice sheet and ocean and hosting societally important fisheries. We combine recent bathymetric, atmospheric, and oceanographic data with a buoyant plume model to show that summer subglacial discharge from 136 tidewater glaciers, amounting to 0.02 Sv of freshwater, drives 0.6-1.6 Sv of upwelling. Bathymetric analysis suggests that this is sufficient to renew most major fjords within a single summer, and that these fjords provide a path to the continental shelf that is deeper than 200 m for two-thirds of the glaciers. Our study provides a first pan-Greenland inventory of tidewater glacier fjords and quantifies regional and ice sheet-wide upwelling fluxes. This analysis provides important context for site-specific studies and is a step towards implementing fjord-scale heat, freshwater and nutrient fluxes in large-scale ice sheet and climate models. This article is protected by copyright. All rights reserved.