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The cytochrome P450 decarboxylase from Staphylococcus aureus can produce a diene from a C18 monounsaturated fatty acid: A spectroscopic, structural and kinetic characterisation.
Get PDFCertain members of the bacterial cytochrome P450 152 family (CYP152) are peroxygenases that catalyse the decarboxylation of fatty acids into terminal olefins making them attractive biocatalysts for biofuel production. To date, the characterisation of decarboxylating CYP152s has mainly focused on their reaction with saturated fatty acid substrates. CYP152s are often co-purified with a bound substrate, which is generally removed before further experiments are conducted. In the present work we identified that heterologous over-expressed CYP152 from Staphylococcus aureus (OleTSa) is co-purified with the trans-monounsaturated C18:1 fatty acid, elaidic acid. We report the spectral, thermodynamic and kinetic characteristics of OleTSa bound to both elaidic acid and its saturated counterpart, stearic acid. Despite differing spectral profiles, metabolic and kinetic studies reveal that OleTSa is capable of decarboxylating elaidic acid, converting it to heptadeca-1,8-diene following addition of hydrogen peroxide, at the same rate and chemoselectivity as the conversion of stearic acid to 1-heptadecane. The X-ray crystal structure of the as purified OleTSa in complex with elaidic acid is also presented, allowing for several key residues to be identified for site-directed mutagenesis studies. The influence of the site-directed variants on C18:0 and C18:1 product formation, binding thermodynamics and kinetics have been investigated, showing that while spectral differences occur as a likely result of perturbing the binding pocket, this does not alter the chemoselectivity of the enzyme. Our work provides important insights into the mechanism of decarboxylation of an unsaturated fatty acid substrate by OleTSa potentially expanding the sustainable substrate space available for CYP152s
Effects of the 2023 Poole Harbour oil spill on sediment bacterial communities and ecosystem functioning
Get PDFIn March 2023, approximately 27 t of fluid from an oil and gas reservoir (containing approximately 85 % water and 15 % crude oil spilt from a fractured pipeline beneath Ower Bay creek, entering Poole Harbour (Dorset, UK). This event provided a unique opportunity to investigate the impacts of hydrocarbon contamination on microbial communities in-situ in a temperate coastal, shallow, fine sediment environment. Our aims were to quantify hydrocarbon concentrations (via gas chromatography mass spectrometry (GC–MS)) and effects on microbial community structure and functional potential (via metagenomic sequencing) to understand the capacity for microbial biodegradation across the impacted region. Hydrocarbon contamination was localised to the Spill Site (approximately an area of 1500 m2) at the head of the creek, with minimal impact at the Mid Point (164 m from the Spill Site) and End Point (387 m from the Spill Site) and with no indication of contamination at Brownsea Island located in the heart of the harbour. By October 2023, n-alkane and 4–5 ring PAH concentrations had declined to background levels, highlighting the combined effects of the remediation response and natural hydrocarbon biodegradation at the Spill Site. Clear changes in bacterial community structure were observed in the seven months following the spill, with notable hydrocarbon-degrading bacteria i.e. Anaerolinea, Thiobacillus and Dechloromonas favouring the Spill Site, suggesting a significant increase in anaerobic biodegradation occurred as a result of significant increase in assA (anaerobic alkylsuccinate synthase), abcA (anaerobic benzene carboxylase) and ahyA (anaerobic alkane hydroxylase) genes. Overall, 24 alkane and aromatic hydrocarbon degradation genes, from both aerobic and anaerobic degradation pathways, were identified from contigs throughout the study site, being present within 48 out of 221 Metagenome-Assembled Genomes (MAGs), highlighting the sites capacity for hydrocarbon biodegradation under both aerobic and anaerobic conditions
Consent, Coercion, Colonialism: A Manifesto for Digital Rights from the Left
Get PDFDigital transitions, involving the widespread adoption of biometric, algorithmic, and AI systems across public and private sectors, are often framed as inevitable and necessary for progress. However, these transitions are not neutral. They are shaped by coercive data extraction practices of digitalisation, which consolidate corporate power, and reproduce colonial social relations. At the center of this process is the erosion of meaningful consent, alongside the expansion of surveillance infrastructures that restructure subjectivity without recognition or accountability. Dominant rights frameworks, including liberal notions of personhood and existing legal protections, fail to confront these harms. Regulatory frameworks overlook relational dynamics, systemic misrecognition, and the asymmetries of digital colonialism. Coercion is overtaking consent in the digital realm. A new political struggle is needed to reclaim subjectivity and argue for a manifesto of digital rights from the left
Self, communitarian self, and personhood: a theoretical account of ‘non-compliance’ in corporate governance in Africa
Get PDFThis paper introduces a new theoretical framework that opens significant opportunities for advancing accounting research in Africa and other Majority World contexts. Critical accounting research has long shown that governance reforms rooted in Anglo-American traditions (e.g. individualism, self-interest, and calculative rationality) often travel poorly to the Majority World contexts, yet explanations typically focus on institutional weakness or strategic resistance. Drawing on Gyekye’s (1978, 1987/1995, 1997) conception of personhood, which understands agency as relational, morally constituted, and communally accountable, we argue that such explanations overlook a deeper ontological dissonance between Western governance assumptions and Indigenous understandings of the self. Using evidence from corporate governance practices in Kenya, the paper shows how actors enact agency in ways that are intelligible within communitarian moral frameworks but framed as ‘non-compliance’ through the dominant Anglo-American governance lens. Rather than framing these practices as governance deficits, we demonstrate how they reflect ontologically grounded enactments of moral agency and, in some cases, explicit critiques of the imported corporate governance prescriptions. The paper contributes to accounting scholarship by rethinking agency, legitimacy, and governance beyond universalist framing by centring Indigenous conceptions of personhood as generative theoretical resources
Invisible but present: Black Southern African social workers’ experiences of working in children’s services in England
Get PDFThe thesis reports on a practitioner-initiated practice-near research study investigating the experiences of Black social workers who have migrated from the Southern African region to England and practice in children’s services settings. The study involved a qualitative psychosocial methodology, with a total of 14 in-depth interviews and a focus group being completed. The seven social workers who participated in this study spent their formative years in the Southern African Development Community region. Analysis of the interview accounts revealed multitudinous challenges linked to discriminatory practices, inequalities in workload management and everyday incivilities and microaggressions. These challenges compounded other adversities experienced as a Black African migrant professional and were reflected in a personal subjective experience of feeling isolated, unsupported and rejected. Additionally, for the participants, migration was found to be as much a psychological experience as it was physical and cultural, with upbringing and childhood experiences significant in shaping how social work was embraced as a vocation. Through the analysis, the thesis contributes to the wider professional field via insights it affords into the journeys and personal and professional identities of Black Southern African social workers practising in English children’s services. It focuses on how members of this community navigate power dynamics and in organisations, support structures and the social and emotional demands of frontline child and family social work. This has implications for the way in which anti-racist supervision and leadership are conceptualised and further understanding of the influence of postcolonial histories on workplace relationships, foregrounding ground-shifting approaches to changing practice
Priming for power: evaluating warm-up protocols and sprint performance in cycling
Get PDFWarm-ups are employed to elevate muscular temperature prior to an exercise task, enhancing performance and reducing injury risk. Increases in muscular temperature enhances performance by facilitating an increase in blood flow to the respiring tissues, faster nerve conduction velocity, higher enzymatic activity, and enhanced metabolic responses. Two types of warm-ups exist, increasing muscle temperature differently: Passive warm-ups via external means, and active warm-ups through exercise. In BMX racing, where scientific literature is sparse, no studies have established warm-up strategies to optimise BMX performance. To begin to address this gap, a systematic review examined the effects of warm-up routines on ≤ 30 s sprint cycling performance, identifying warm-up intensity, duration, and recovery period between the warm-up and exercise task as critical factors influencing sprint performance. However, intensity definition varied, and cadence, a known determinant of BMX performance was a significant omission from the literature included. To extend these findings, a laboratory-based experimental study explored whether the manipulation of cadence during a sprint-based warm-up could influence subsequent 30 s Wingate performance following a 30-minute recovery, reflecting BMX race conditions. Twelve male recreational cyclists completed warm-ups under different cadence conditions, with blood lactate, skin temperature, energy system contributions, resting gas exchange, and Wingate performance assessed. Cadence manipulation successfully elicited intensity variation; however, following a 30-minute recovery, any performance benefits had dissipated, with no significant differences observed between conditions. These findings suggest that maintaining thermal and neuromuscular readiness across prolonged recovery may require a stronger warm-up stimulus, supported by direct markers of readiness and carefully timed before performance
Meaning maintenance drives science rejection
Get PDFCurrently, ideologically-motivated discourses are actively undermining perceived value of science, with evidence-based policy-making being increasingly replaced with antiscience agendas shaped by political, spiritual, or conspiratorial ideologies. We propose that motivated science rejection is driven by compensatory mechanisms serving to maintain a coherent understanding of reality when this understanding conflicts with science. Drawing on the meaning maintenance model and the assumption of fluid compensation—any belief framework can be replaced with another to restore meaning—we argue that when science violates meaning, it is rejected in favour of an alternative framework of ideological beliefs, regardless of their epistemic validity. Interventions that align science with meaning-maintenance needs to minimise compensatory responses may prove promising in reducing science rejection
Solidarity as a Fundamental Principle of EU Law
No full textThis article examines the principle of solidarity in the EU legal order by tracing the evolving contours of its meaning and operation in recent and emerging jurisprudence. It argues that interpreting solidarity through the lens of its underlying drivers (functional, axiological and identity based) offers a conceptually coherent account of its normative scope and boundaries. Solidarity has largely assumed an instrumental character, oriented towards securing the effective operation and systemic stability of the Union and its legal architecture. Yet the principle now stands at a transformative juncture, where a functional rationale no longer suffices to explain how it takes effect. Through instances that defy a purely instrumental logic, the article reconceptualises solidarity as a bearer of shared values and collective identity. This reframing is not only a matter of candour but indispensable for conceptual clarity and for engaging more directly with the constitutional stakes of sovereignty and belonging
Age is just a number: Clustering gait and functional measures.
Get PDFObjective: As we age, we walk slower, but it remains unclear whether this is consistent at an individual level. Current clinical assessment of function assumes movement deficits with older age, and clinical norms are linked to decades or specific age stratifications such as “old” or “oldest-old”. Current approaches stratifying by age may hide trends of higher and lower functioning individuals within each age bracket. Therefore, our aim was to cluster spatiotemporal data, from the 1000 Norms Project, to understand if patterns of function could be identified without using age as a factor. Methods: The 1000 Norms Project, a cross-sectional, observational study, collected gait, functional performance, and self-reported health data (participants (n = 695) aged 18–92 years). Spatiotemporal and functional data were clustered, after rendering the parameters dimensionless. Results: Three clusters were identified (n = 277, 208, 210). Although age significantly differed between clusters, each showed a broad range (e.g. 20–92 years). Additionally, walking speed (Froude number) did not differ between clusters, often used to separate by age. Our clusters defined 3 groups, ‘higher functioning’, ‘age average’ and ‘cautious gait’, whose spatiotemporal, functional performance, strength and quality of life measures vastly differed, independent of walking speed and including a wide range of ages. Conclusion: Our analysis suggests that age should not be used to separate individuals into groups, and that our assumption of “age matters” may not be relevant when determining true functional movement ability. Further work is needed to understand normal senescence, true negative loss, and reversible loss within these functionally different groups