114612 research outputs found
Sort by
Increasing the versatility of the biphenyl-fused-dioxacyclodecyne class of strained alkynes
Get PDFBiphenyl-fused-dioxacyclodecynes are a promising class of strained alkyne for use in Cu-free ‘click’ reactions. In this paper, a series of functionalised derivatives of this class of reagent, containing fluorescent groups, are described. Studies aimed at understanding and increasing the reactivity of the alkynes are also presented, together with an investigation of the bioconjugation of the reagents with an azide-labelled protein
Deformations of half-canonical Gorenstein curves in codimension four
Get PDFRecent work of Ablett (2021) and Kapustka, Kapustka, Ranestad, Schenck, Stillman and Yuan (2021) outlines a number of constructions for singular Gorenstein codimension four varieties. Earlier work of Coughlan, Gołȩbiowski, Kapustka and Kapustka (2016) details a series of nonsingular Gorenstein codimension four constructions with different Betti tables. In this paper we exhibit a number of flat deformations between Gorenstein codimension four varieties in the same Hilbert scheme, realising many of the singular varieties as specialisations of the earlier nonsingular varieties
New fluorescent auxin derivatives : anti-auxin activity and accumulation patterns in Arabidopsis thaliana
Get PDFAuxin belongs among major phytohormones and governs multiple aspects of plant growth and development. The establishment of auxin concentration gradients, determines, among other processes, plant organ positioning and growth responses to environmental stimuli.
Herein we report the synthesis of new NBD- or DNS-labelled IAA derivatives and the elucidation of their biological activity, fluorescence properties and subcellular accumulation patterns in planta. These novel compounds did not show auxin-like activity, but instead antagonized physiological auxin effects. The DNS-labelled derivatives FL5 and FL6 showed strong anti-auxin activity in roots and hypocotyls, which also occurred at the level of gene transcription as confirmed by quantitative PCR analysis. The auxin antagonism of our derivatives was further demonstrated in vitro using an SPR-based binding assay. The NBD-labelled compound FL4 with the best fluorescence properties proved to be unsuitable to study auxin accumulation patterns in planta. On the other hand, the strongest anti-auxin activity possessing compounds FL5 and FL6 could be useful to study binding mechanisms to auxin receptors and for manipulations of auxin-regulated processes
Sustained benefits of early childhood education and care (ECEC) for young children’s development during COVID-19
Get PDFEarly childhood education and care (ECEC) settings faced significant disruption during the COVID-19 pandemic, compromising the continuity, stability, and quality of provision. Three years on from the first UK lockdown as pandemic-era preschoolers enter formal schooling, stakeholders are concerned about the impact of the disruption on children’s cognitive and socioemotional development, especially those from socioeconomically disadvantaged backgrounds. Using parent-report data from 171 children aged 5 - 23 months (M=15 months) in March - June 2020 living in the UK, we investigate whether previously attested positive associations between ECEC attendance and the development of language and executive functions was maintained as early years settings navigated operational challenges over the first full year of the pandemic. In response to concerns about ‘school readiness’, we analyse the relationship between ECEC attendance and children’s communication, problem-solving, and personal-social development. ECEC was associated with greater growth in receptive vocabulary over the 12-month period. In children from less advantaged backgrounds, ECEC was also associated with greater growth in expressive vocabulary. Our data suggest a similarly positive association between ECEC attendance and the communication and problem-solving skills of children from less advantaged backgrounds, and between ECEC and the personal-social development of all children. Overall, results suggest that ECEC had sustained learning benefits for children growing up during the pandemic despite ongoing disruption to settings, with specific benefits for children from less affluent home environments. As pandemic-era children progress to primary school, we discuss the importance of adapting their learning conditions and adjusting the expectations placed on them
‘Seen’ through records : parents’ access to children’s social care records in an age of increasing datafication
Get PDFGeneral Data Protection Regulations state that parents may submit a Subject Access Request (SAR) to see personal records held about them. In this article, we draw on interviews with parents who have made an SAR in order to view their children’s social care records. Their experiences reveal the significant barriers of time, energy and bureaucracy that they faced in accessing their children’s records. The parents felt that they were ‘seen’ through their records, reported inaccuracies in information about them and relayed the devastating impact that false allegations of maltreatment continued to have in their lives. Datafication becomes an integral part of the unequal power dynamic between parents and professionals, further shifting the balance towards professionals, damaging fragile trust and engagement. Crucially, there are ethical questions raised for the social work profession about the accessibility and accountability of local authority processes when parents seek justice and reparation for harm. Given the importance of records in decision making about intervention in families lives and increasing datafication of public services working with families through electronic systems including predictive analytics, our indicative findings point to the need for further investigation
The positioning mechanics of microtubule asters in Drosophila embryo explants
Get PDFMicrotubule asters are essential in localizing the action of microtubules in processes including mitosis and organelle positioning. In large cells, such as the one-cell sea urchin embryo, aster dynamics are dominated by hydrodynamic pulling forces. However, in systems with more densely positioned nuclei such as the early Drosophila embryo, which packs around 6000 nuclei within the syncytium in a crystalline-like order, it is unclear what processes dominate aster dynamics. Here, we take advantage of a cell cycle regulation Drosophila mutant to generate embryos with multiple asters, independent from nuclei. We use an ex vivo assay to further simplify this biological system to explore the forces generated by and between asters. Through live imaging, drug and optical perturbations, and theoretical modeling, we demonstrate that these asters likely generate an effective pushing force over short distances
Impact of hydraulic tortuosity on microporous and nanoporous media flow
No full textUsing two-dimensional porous structures made up of homogeneously arranged solid obstacles, we examine the effects of rarefaction on the hydraulic tortuosity in the slip and early transition flow regimes via extended lattice Boltzmann method. We observed that modification in either the obstacle's arrangement or the porosity led to a power-law relation between the porosity-tortuosity. Along with this, we also found that in the slip-flow regime, the exponent of this relation contains the effect of finite Knudsen number (Kn). In addition, we observed that on properly scaling Kn with porosity and hydraulic tortuosity, a generalized correlation can be obtained for apparent permeability
The impact of mobility costs on cooperation and welfare in spatial social dilemmas
Get PDFFrom over-exploitation of resources to urban pollution, sustaining well-being requires solving social dilemmas of cooperation. Often such dilemmas are studied assuming that individuals occupy fixed positions in a network or lattice. In spatial settings, however, agents can move, and such movements involve costs. Here we investigate how mobility costs impact cooperation dynamics. To this end, we study cooperation dilemmas where individuals are located in a two-dimensional space and can be of two types: cooperators–or cleaners, who pay an individual cost to have a positive impact on their neighbours–and defectors–or polluters, free-riding on others’ effort to sustain a clean environment. Importantly, agents can pay a cost to move to a cleaner site. Both analytically and through agent-based simulations we find that, in general, introducing mobility costs increases pollution felt in the limit of fast movement (equivalently slow strategy revision). The effect on cooperation of increasing mobility costs is non-monotonic when mobility co-occurs with strategy revision. In such scenarios, low (yet non-zero) mobility costs minimise cooperation in low density environments; whereas high costs can promote cooperation even when a minority of agents initially defect. Finally, we find that heterogeneity in mobility cost affects the final distribution of strategies, leading to differences in who supports the burden of having a clean environment
Exploring realism in virtual testing : towards a scalable platform using open-source solutions for automated driving systems
Get PDFThe informational impact of prudential regulations
No full textBanks take costly actions (such as capitalization, liquidity holding, and advanced risk management) to avoid financial distress and creditor runs. While directly affecting a bank’s risks, such actions can also signal the bank’s fundamentals. We show that prudential regulations have an informational impact: sufficiently tight regulations can eliminate inefficient separating equilibria in banks’ signaling game, thereby changing the information available to creditors and their incentives to run. When accounting for this informational impact, tightening regulations can improve banks’ payoffs and be considered bank incentive-compatible. We support this novel, information-based rationale for regulations with evidence from the US liquidity requirement