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An MaOEA/Local Search Hybrid Based on a Fast, Stochastic BFGS Using Achievement Scalarizing Search Directions
No full textWe consider the problem of multiobjective and many-objective optimization in the unconstrained, continuous-variable setting. Can modern EAs designed for this setting (such as NSGA-III) that arguably have proven performance be improved by incorporating local search, and can this be achieved in a general way not requiring excessive tuning of parameters? Optimization in this setting is usually found to be increasingly challenging as the number of objectives is increased (albeit some works suggest the contrary) and this is believed to be because of the weakness of selection pressure available from Pareto comparisons, challenges in maintaining diversity and/or, in decomposition-based methods, due to the number of search ``directions'' that must be managed. To investigate our problem, we propose integrating a many-objective evolutionary algorithm (MaOEA) with local-search techniques based on derivative-free BFGS-like algorithms. This is done in two slightly different ways both using achievement scalarizing functions. Our results on well-known benchmark functions suggest a significant improvement is possible with reasonable assumptions about how to choose the base MaOEA parameters and a principled and general approach to choosing the remaining parameters in the hybrid algorithm. Our findings underline the effectiveness of hybrid methods and suggest powerful algorithms from mathematical programming can be used even without gradients
Mode structure evolution of a modeless multiwavelength Raman fiber laser
No full textMultiwavelength Raman fiber lasers (MRFLs) are used in a number of applications. A longitudinal mode structure of light in MRFL is directly related to the temporal properties of laser radiation. In this Letter, we demonstrate a modeless multiwavelength Raman fiber laser based on a low-reflection Sagnac loop mirror (SLM). The MRFL exhibits a discrete multi-longitudinal mode structure at a low pump power level. The difference in longitudinal mode spacing for various polarization states of the MRFL leads to the appearance of sub-peak discreteness and recombination at different frequencies in the RF spectrum. As the pump power increases, the discrete longitudinal modes of each polarization mode gradually broaden until adjacent modes overlap and the MRFL undergoes a decoherence process. The low-reflection SLM effectively facilitates broadening longitudinal modes to a modeless state. Modeless MRFL exhibits highly stable temporal intensity distribution
Trade Disintegration and Agri-Food Trade: United Kingdom Exit From EU
Get PDFThis study provides a comprehensive analysis of the impact of the Trade and Cooperation Agreement (TCA) on the United Kingdom's agri-food trade post-Brexit. Utilising a difference in differences (DiD) methodology, we find a significant decline in both the value and quantity of UK agri-food exports and imports post-TCA, with prices increasing due to additional trade costs imposed by worsened market access and additional border checks. This disruption in trade underscores the necessity for policy interventions to mitigate the adverse effects of the TCA, particularly for maintaining market competitiveness and addressing the specific challenges faced by importers. The study also highlights the importance of legal enforceability in trade agreements, especially concerning agricultural and sanitary and phytosanitary (SPS) provisions, to facilitate market access and enhance trade volumes. Deepening TCA to the Agriculture Extra agreement with legal enforceability would substantially mitigate the trade disruption
Parkinson’s associated protein DJ-1 regulates intercellular communication via extracellular vesicles in oxidative stress
Get PDFMutations in DJ-1 cause autosomal recessive Parkinson’s disease (PD). Several functions have been attributed to DJ-1, including a key role in the protection from oxidative stress. However, how this protein contributes to PD pathogenesis is still unclear. Recently, DJ-1 has been identified at higher concentrations in extracellular vesicles (EV) from biological fluids of PD patients, providing a link between EV and a protein associated with PD. In this study, EV were purified from the medium of control and rotenone-treated wild-type and DJ-1 KO differentiated SH-SY5Y cells. EV quantity was assessed using flow cytometry, and their proteomic cargo was analysed via mass spectrometry. We identified an altered EV response to rotenone in DJ-1 KO cells compared to wild-type. Mass spectrometry analysis identified 116 proteins with significantly altered abundance between the two genotypes, indicating a role for DJ-1 in modulating EV cargo under oxidative stress conditions. Label-free identification of oxidative modifications indicated that DJ-1 clearly influences the oxidative profile of EV proteins. Additionally, we showed that DJ-1 KO alters the ability of the secretome to stimulate macrophage migration, suggesting functional consequences of DJ-1 deficiency in secretome-mediated responses to oxidative stress. The altered EV response to rotenone was confirmed in iPSC-derived neurons lacking DJ-1 compared to isogenic controls. Our results reveal a distinct role for DJ-1 in regulating intercellular communication under oxidative stress, highlighting a novel EV-mediated function of DJ-1 that may contribute to Parkinson’s disease pathogenesis
Leveraging the Rich Spatiotemporal Features of Lattice Light-sheet Microscopy with Machine Learning and AI
Get PDFLive-cell imaging allows scientists to observe the dynamics of living cells across time. Lattice Light-sheet (LLS) microscopy is one such method that captures these processes at high spatiotemporal detail in 4D. LLS enables us to observe previously unknown events, however, the large data size, specialized processing needs, and the complexity of the feature rich datasets pose significant challenges for maximizing the utility of this technology. To this end, we developed napari-lattice, a python plugin within napari, an n-dimensional viewer that streamlines LLS analysis. It enables users to extract specific regions of interest within LLS data without processing the entire volume. Furthermore, napari-lattice integrates seamlessly with standard image analysis pipelines, enabling segmentation and feature extraction in a single end to end workflow. We applied the napari-lattice workflow to live-cell imaging of Neutrophil extracellular trap (NET) formation, a form of programmed cell death exhibiting dynamic changes in cell shape, topology and nuclear DNA conformation, as multilobular nuclei decondense and DNA is extruded extracellularly. Using primary human neutrophils, we study how cells from different donors behave under various NET-inducing stimuli. To enable this, we developed an end-to-end workflow that extracts morphological information in 2D and 3D for live cells over time, which is modular and scalable. Traditionally, time series data is summarized using basic statistics such as mean, maximum, number of peaks and area under the curve. However, this approach fails to capture the full complexity and dynamics of the temporal changes. We address this limitation by using tsfresh, a python package that computes multiple statistical properties to summarize temporal changes
The cousin marriage tradition, colonial shocks, and the performance of informal firms in sub-Saharan Africa
Get PDFResearch Summary The paper explores how the deep historical roots of informal institutions influence current informal businesses. It proposes that both pre-colonial institutions—the tradition of cousin marriage—and the subsequent shocks of colonization still impact the performance of informal firms. We theorize on how the effects of historical family systems are moderated by the traumatic and spatially heterogeneous shocks of colonialism, in particular the cultural values of the colonizers (individualism) and their religious (missionary) activities. Our hypotheses are tested by regression analysis based on surveys of informal businesses in multiple regions of eight African countries. We find that the cousin marriage tradition is negatively associated with the performance of current informal businesses though this relationship is attenuated in places where colonizers were more individualistic. Managerial Summary This paper explores how the pre-colonial family institutions—the tradition of cousin marriage—and the subsequent shocks of colonization jointly impact the performance of contemporary informal firms in sub-Saharan Africa. We propose that the historical tradition of cousin marriage has persistent and negative effects on the revenue and labor productivity of contemporary informal businesses. This is because informal entrepreneurs in ethnic areas with the cousin marriage tradition may prioritize social obligations over economic incentives. However, these relationships are attenuated in ethnic areas colonized by European countries with more individualistic cultural values. Our findings highlight the importance for business owners and managers to understand the deep historical roots of the social norms of the communities and groups with which they interact
Toward Epistemic Justice: Using a Multimodal Interpretative Phenomenological Analysis Methodological Approach in Research With Autistic Children
Get PDFIn this paper we critically examine the systemic marginalisation of autistic children’s contributions in research and make the case for how a multimodal application of Interpretative Phenomenological Analysis (IPA) can contribute towards more inclusive and equitable knowledge production. Drawing on an empirical study into the subjective everyday experiences of ten autistic children aged nine to eleven years in mainstream primary schools in England, our research foregrounds the need for methodological innovation to accommodate diverse communicative modalities, particularly among intermittently- and non-speaking participants. By integrating creative adaptations - including photo-elicitation, asynchronous text-based interviewing, and participant-led multimodal engagement – we provide worked examples of how IPA’s flexibility can facilitate more authentic, participant-driven meaning-making processes while maintaining methodological rigour. In doing so, we explore how multimodal IPA can provide a framework for challenging historically dominant neuronormative research practices in an attempt to address both testimonial and hermeneutic forms of epistemic injustice. The paper concludes by exploring the broader ethical and practical implications of our study, arguing for the adoption of approaches to research and professional practice that anticipate and accommodate autistic modes of communication in a shift toward greater inclusivity and epistemic equity
A challenging case of transvenous pacemaker implant in a patient with anomalous pulmonary venous drainage
Get PDFPartial anomalous pulmonary venous drainage (PAPVD) is a congenital heart disease that can often remain undiagnosed due to its asymptomatic nature. The prevalence was thought to be around 0.4% to 0.7% in the adult population.[1] We report a case of right superior pulmonary venous drainage into the superior vena cava (SVC) in a patient with known hypertrophic cardiomyopathy and impaired left ventricular systolic function. The anomalous drainage pattern was identified during device implantation, necessitating real-time troubleshooting. Contrast fluoroscopy played a critical role in delineating the aberrant anatomy, guiding wire manipulation through the superior vena cava while avoiding entry into the right pulmonary vein
Experiences of UK general practice trainees undertaking workplace-based assessment who received a developmental outcome at their annual review of competency progression
Get PDFBackground: Workplace-Based Assessment (WPBA) forms part of the integrated assessment system for UK General Practice (GP) licencing. An Annual Review of Competence Progression (ARCP) panel evaluates either satisfactory progress or requirement for development of specific capabilities. We aimed to explore GP trainees’ experiences of undertaking WPBA when failing to progress by receiving a ‘developmental’ outcome 2 or 3. Methods: We used a qualitative design employing Systematic Grounded Theory and semi-structured interviews. A purposive sample of GP trainees was recruited, at different stages of training and with varying demographic characteristics, who had a previous ARCP developmental outcome. Interviews were recorded, transcribed verbatim and analysed, facilitated by NVivo 14. Results: We interviewed 20 GP trainees during 2024 who received a developmental outcome between 2020 and 2023. We identified five themes: ‘potential for early intervention’, included personalised support and better information provision; ‘perceptions of how WPBA reflected trainee performance’ including perceptions of the validity and reliability of WPBA and need for fair, trustworthy and transparent processes to reduce unfair discrimination; ‘communication difficulties’ arose in relation to culture, language and reflection for some study participants; ‘relationships with peers and educational setting’ were felt to affect performance; and some participants experienced negative ‘effects on wellbeing’. Conclusion: Suggestions aimed at supporting and overcoming potential challenges to undertaking WPBA during GP training, including personalised support, reviewing fairness of assessments, addressing communication and cultural barriers, enhancing training environments, fostering positive relationships, and mitigating negative wellbeing impacts, some of which were already in place, with others requiring development
“I've always felt in the middle of hearing people and the Deaf community.” What is it like to grow up with hearing loss?
Get PDFObjective: Hearing loss in children and adolescents can significantly impact social interactions, language development, and emotional well-being, often leading to academic and mental health challenges. This qualitative, retrospective study examines how individuals reflect on their experiences growing up with hearing loss, including the challenges they faced, the support they received, and the coping strategies they developed over time. Design and study sample: Participants aged 16 and older with personal experiences of hearing loss were recruited through audiology services in England and Scotland (UK), as well as community and online channels. Nineteen semi-structured interviews were conducted in person or online, following a flexible approach to explore participants’ retrospective accounts of growing up with hearing loss. Reflexive thematic analysis was used to identify, refine, and review themes, ensuring diverse perspectives were captured through collaborative analysis. Results: Interrelated themes were identified from participants’ reflections of growing up with hearing loss, showing how they continually adapt and reshape their experiences as part of an ongoing coping and adjustment process across various social contexts. Conclusions: This study highlights the lasting impacts of growing up with hearing loss on communication, social relationships, emotional well-being, and education
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