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Observation of tt¯γγ production at s=13 TeV with the ATLAS detector
No full textThis paper presents the first observation of top-quark pair production in association with two photons (tt¯γγ). The measurement is performed in the single-lepton decay channel using proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider. The data correspond to an integrated luminosity of 140 fb−1 recorded during Run 2 at a centre-of-mass energy of 13 TeV. The tt¯γγ production cross section, measured in a fiducial phase space based on particle-level kinematic criteria for the lepton, photons, and jets, is found to be 2.42−0.53+0.58fb, corresponding to an observed significance of 5.2 standard deviations. Additionally, the ratio of the production cross section of tt¯γγ to top-quark pair production in association with one photon is determined, yielding (3.30−0.65+0.70)×10−3
Variable Symmetry Constraints-Based Stability Analysis of Large Delayed Cyber-Physical Power System
Get PDFLinear matrix inequality (LMI)-based delay-dependent stability analysis methods have been effectively utilized in the delayed cyber-physical power system (DCPPS). However, the significant computational burden associated with solving large-scale LMIs presents a substantial challenge when these methods are applied to real-world power systems. This article investigates an efficient evaluation method for the delay-dependent stability of the large DCPPS by presenting a variable symmetry constraints-based approach. First, by exploring the highly symmetric characteristics of control loops and renewable energy sources (RES), this article gives new structure restrictions for the weighting matrices required in the LMI-based stability criterion to reduce the number of decision variables (NDVs). In contrast, the existing methods focus only on the symmetric characteristics of traditional generators and are not applicable to large DCPPS integrated with the RES. Then, by introducing an adjustable parameter into the proposed structure restrictions, the approach based on variable symmetry constraints is established to bridge the gap where the existing constant methods fail to address the variable stability conditions. Moreover, the proposed variable symmetry constraints-based approach is more relaxed than the existing method since it keeps the NDVs in the LMIs unchanged despite massive generators equipped in the same control area of the DCPPS. Case studies are based on the large DCPPS with illustration of the load frequency control (LFC) schemes and the 39-Bus New England System to demonstrate the superiority of the proposed method. The proposed method is verified to be available to analyze the delay-dependent stability of the large-scale DCPPS efficiently while guaranteeing the computation accuracy
Transitioning of the maternal and newborn health surveillance online digital health (MATSurvey) platform from a research institution to the government DHIS2 tracker
Get PDFThe successful transition of a digital platform from a research institution to a government system in under-resourced environments necessitates effective cooperation among various stakeholders and a strong sense of responsibility from both the Malawi Ministry of Health (MoH) and all users. The article aims to describe the implementation and lessons learned in transitioning a maternal surveillance digital platform (MATSurvey) from a research-based to a government-owned system in Malawi. Methods: The transition process involved active participation of the MoH leadership and close cooperation with healthcare workers and partners. The process comprised six stages, including stakeholder engagement, user feedback, system design, obtaining stakeholder input on the design, system development and testing, piloting and full implementation. The process emphasised stakeholder engagement, with technical teams from the MoH and Malawi Liverpool Wellcome Programme incorporating feedback during development. Results: The successful transition of the MATSurvey platform from the Malawi Liverpool Wellcome Programme to the Digital Health Information System 2 tracker required strong leadership from the MoH, active engagement of partners and stakeholders, and a gradual, inclusive process. Challenges such as reliance on donor funding and delays in government support were notable, while ensuring clear data governance policies, system scalability, effective communication, and comprehensive training contributed to a smoother transition and successful adoption. Conclusion: Transitioning of a digital health platform such as the MATSurvey platform requires strong leadership and supervision to ensure adoption, acceptance and ownership. The active involvement of MoH, partners and stakeholders accelerated transitioning of the platform despite challenges in funding, which ultimately resulted in delaying the process
Fair Interventions in Weighted Congestion Games
Get PDFIn this work we study the power and limitations of fair interventions in weighted congestion games. Specifically, we focus on interventions that aim at improving the equilibrium quality (price of anarchy) and are fair in a suitably defined sense. Within this setting, we provide three key contributions. First, we show that no fair intervention can reduce the price of anarchy below a given factor depending solely on the class of latencies considered. Interestingly, this lower bound is unconditional, i.e., it applies regardless of how much computation interventions are allowed to use. Second, we design a taxation mechanism that is fair and achieves a price of anarchy matching this unconditional lower bound, all the while being polynomial-time computable. Third, we show that no intervention (fair or not) can achieve a better approximation if polynomial computability is required. We do so by proving that the minimum social cost is NP-hard to minimize below a factor identical to the one previously introduced. In doing so, our work shows that the algorithm proposed by Makarychev and Sviridenko [29] to tackle optimization problems with a “diseconomy of scale” is optimal, and provide a novel way to derandomize its solution via equilibrium computation
A Qualitative Vignette Study of Perceived Barriers and Facilitators of Bystanders in Racism in the Higher Education Context in Finland.
No full textBystanders play a potentially important role in intervening in incidents of racism, but they often fail to act. Much research has focused on investigating facilitators and barriers to bystander behavior, but mainly in the context of sexual violence. There is a dearth of research in the context of racism, especially outside the English-speaking world. In this pilot study, we employed a qualitative approach to explore bystander facilitators and barriers in higher education students in Finland. Online participants (N = 649) read two vignettes depicting a racist incident and wrote open-ended answers on factors that would facilitate and prevent intervention. We constructed six main themes using an inductive thematic analysis: (i) Perceived self-efficacy to intervene; (ii) Justification and moral reasoning; (iii) Clarity of the situation; (iv) Responsibility and permission to act; (v) Social relationships, support, and presence of others; and (vi) Consequences and impacts of action. We discuss the results with a reference to theories and literature, as well as the unique context of Finland
A qualitative exploration into the experiences of the menstrual cycle in relation to alcohol use and research
No full textIntroduction: Despite approximately half of the population experiencing menstrual cycles, little is known about experiences of fluctuations in mood and behavior relating to alcohol use. Literature has investigated whether the cycle affects alcohol use, but none have explored whether individuals are conscious of effects. It is also crucial to understand what people believe is important for researchers to investigate within this topic. The aim was to qualitatively investigate experiences of the menstrual cycle and how it may affect alcohol use. The second aim was to understand what methods researchers should consider. Methods: Inductive thematic analysis was used to analyze 20 semi-structured interviews from individuals in the UK. Results: Results showed alcohol themes: alcohol during menses (reduced consumption); motives for consumption (less social drinking during menses and drinking to cope with premenstrual symptoms); and conscious changes in alcohol use (individuals were unaware of fluctuations). For research themes: menstrual literacy (inadequate education); healthcare (inconsistencies in healthcare provision); and research topics (key areas suggested). Conclusion: Overall, there are some conscious fluctuations in alcohol use, with regard to menses, and menstrual literacy was generally poor. Further research is needed for other samples (e.g., menopausal individuals and alcohol). Also, improvements in menstrual education are needed to improve menstrual literacy
The two-child policy was not associated with an increase in abortions among its target population
No full textIn 2015 the UK government abolished means-tested child-related social security payments to households for third or subsequent children born from April 2017 (the ‘two-child limit’). From 2017 to 2021 there was a sustained increase in the number of abortions annually in England, following a previously flat trend. Using abortion-level microdata from the Department for Health and Social Care, we analysed whether this increase was primarily among women with two or more existing children in more deprived areas, consistent with being a response to the two-child limit. Descriptive analysis and interrupted time series modelling showed that the increase in numbers of abortions over time was not associated with having more children or living in more deprived areas. Instead, from 2017 onwards the previously declining trend among people with no or one previous births reversed. The pattern of change at area level was nearly identical across deciles of the Index of Multiple Deprivation. The cumulative impoverishing effects of austerity may affect abortion decision-making in England generally, but the two-child limit specifically is not associated with the change that followed its introduction. The primary drivers of recent increases in abortions may be non-material, such as uncertainty about the future beyond immediate financial considerations
Dynamic multi-factor approach for deriving embodied carbon limit of building structures: Methodology and application in China
No full textEstablishing scientifically grounded embodied carbon limits is essential for guiding low-carbon structural design and translating macro-level decarbonization targets into actionable regulatory parameters. Here we propose a dynamic, multi-factor methodology for deriving embodied carbon limits of building structures, accounting for evolving carbon budgets and shifts in their allocation to embodied carbon-related activities in regions with a transitioning construction sector. This methodology integrates top-down budget decomposition with bottom-up benchmarking to respectively determine upper and lower bounds of embodied carbon limits for new construction, renovation, and maintenance. Furthermore, multi-factor adjustments are introduced to customize limits according to building type, regulatory stringency, regional conditions, and lifecycle design requirements. The proposed methodology is demonstrated through an analysis of urban residential building structures in China from 2026 to 2060, which reveals a declining trend in embodied carbon limits over time, and provides reasonable limit ranges corresponding to China's Five-Year Plans (FYPs), e.g., 320.8–360.8 kg CO2/m2 for new construction, 0.96–1.08 kg CO2/(m2·year) for maintenance, and 56.3–63.0 kg CO2/m2 for renovation with a moderate level of regulation during the 2026–30 FYP. The analysis also highlights the benefits of construction management in providing a buffer period for limit relaxation, examines the impact of regional disparities on carbon mitigation feasibility-based adjustments, and offers recommendations for low-carbon lifecycle design to ensure compliance with mitigation targets while providing further design flexibility
How Does Firms’ Artificial Intelligence Adoption Affect Different Stakeholders? A Systematic Review and the AIMS Framework
No full textArtificial intelligence (AI) has been increasingly adopted by firms for different organizational purposes. While such AI adoption is expected to affect firm performance, it may also have different effects on firms’ stakeholders, such as employees, shareholders, and customers. To provide a more comprehensive understanding of the stakeholder implications of AI adoption, we conduct a systematic review of 84 relevant papers published in business journals over the past eight years (2017–2024). Our review suggests that firms’ AI adoption does have different, sometimes conflicting, effects on different stakeholder groups. We also uncover several limitations of the extant literature and develop an integrative AI Impacts Multiple Stakeholders (AIMS) framework that summarizes important directions for future research. Our AIMS framework emphasizes the need to consider underexplored stakeholder groups, such as suppliers and competitors, as well as the trade-offs and dynamics among different stakeholder groups induced by AI adoption. Our framework also encourages future research to move beyond examining the direct impact of AI adoption on stakeholders by investigating when (contextual factors) and why (underlying mechanisms) AI adoption affects stakeholders, thereby advancing the literature on AI–stakeholder relationships. Finally, we discuss the implications for future operations management research, encouraging scholars to adopt a supply chain perspective to study the stakeholder implications of firms’ AI adoption
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