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Effect of haemodialysis on the brain and heart assessed using multiparametric MRI
Get PDFBackground and hypothesis Haemodialysis (HD) patients often develop cognitive impairment, negatively impacting health-related quality of life. We use brain magnetic resonance imaging (MRI) measures to study the acute changes in cerebral water content during HD, alongside chronic changes in HD patients compared to healthy volunteers (HV) to assess whether the brain changes associated with ageing develop more rapidly in HD patients (“accelerated brain ageing”). We also study associated cardiac MRI measures.Methods3T MRI scans were performed during HD in 12 patients to characterise the acute effect of HD on cerebral water content (T1 mapping), alongside previously reported results from the HD-REMODEL trial. MRI changes in brain structure (volumes and T1 of white (WM) and grey matter (GM), WM diffusion fractional anisotropy (FA) and mean diffusivity (MD)), perfusion, blood flow, and cardiac measures were compared between HD patients pre-dialysis and HVs (age and gender matched).ResultsWM T1 increased during HD (3.8±1.7%, p=0.0005). GM and WM volume (total intracranial volume (TIV)-corrected) were lower in HD compared to HVs (GMV/TIV: 0.37[0.34-0.41] vs. 0.42[0.42-0.44], WMV/TIV: 0.34±0.03 vs. 0.37±0.01, p=0.009). In HD, FA was lower and MD higher than HV (FA: 0.32±0.02 vs. 0.35±0.01, MD: 0.59±0.03 vs. 0.53±0.01, p<0.0001). . Higher MD and lower FA was seen in older participants, with steeper slopes in HD (MD: 0.003 vs. 0.0006 x10-3mm2/s/y p=0.003, FA: -0.001 vs -0.0003 units/y p<0.0001), suggestive of accelerated ageing. There were no differences between groups in age-related heart changes. ConclusionsAn acute increase in WM T1 during HD has been shown for the first time, reflecting a rise in brain water content. This is potentially caused by the development of an osmotic gradient across the blood-brain barrier due to slower diffusion of urea, and may contribute to acute symptoms and chronic pathological changes contributing to accelerated brain ageing in HD patients
Relational coordination of state partnership with traditional birth attendants: soft partnering in Ghana's maternal and child healthcare context
No full textBackground: To address maternal and child mortality in resource-constrained settings, policies increasingly emphasise partnerships between state providers and traditional birth attendants (TBAs). Historically, relationships between TBAs and biomedical providers have been characterised by tension and competing knowledge paradigms. This study examines how these tensions can be ameliorated to deliver maternal and child healthcare (MCH). To do so we present a 'positive deviant case' of state-TBA partnership in the Upper East Region of Ghana as a noteworthy sub-national case with better MCH outcomes compared to other regions in the country.Method: Data was generated between December 2019 and October 2020 using document review, key informant interviews and focus group discussions. Study participants were TBAs and representatives of the Ministry of Health and Ghana Health Service (the public health provider) across five levels of health system management: national, regional, district, sub-district and community. We adopted an inductive logic in our analysis and a triangulation process to integrate insights from all three data sources.Findings/Conclusion: We identified three relational coordination mechanisms–flexible governance, pragmatic orientation, and cultural/epistemic inclusivity–underpinned by principles of ‘soft partnering’, namely, adaptability, cultural inclusivity and social capital. Unlike contexts where TBAs have been marginalised, soft partnering in Ghana’s Upper East Region creates spaces for knowledge exchange that transcend historical tensions while honouring both biomedical safety concerns and traditional knowledge systems. We suggest that historical tensions between traditional and biomedical healthcare systems can be bridged through soft partnering, an approach that fosters continuous learning that enhances MCH delivery despite divergent worldviews between traditional and biomedical approaches to childbirth
Delayed rewards weaken human goal directed actions
Get PDFGoal-directed actions are sensitive to the causal association between actions and outcomes, as well as the value of those outcomes. Such sensitivity diminishes when actions become habitual. Based on recent findings in animals, we tested if delaying outcomes relative to actions would weaken sensitivity to outcome revaluation and reduce action rates. In three experiments (N = 290), participants made fictitious investments in companies within contexts that provided either immediate or delayed feedback. After training, participants were informed of a change in markets which affected both companies (one improved and the other worsened). Across all experiments, action rates were lower in the delayed-feedback condition, and outcome revaluation was stronger in the immediate-feedback condition. In addition, self-reported action-outcome knowledge was weaker in the delayed-feedback condition. These findings suggest that delays in reinforcement weaken the action-outcome association critical for goal-directed control. We discuss the potential mechanisms underlying this phenomenon in light of a contemporary theory of goal-directed behavior
Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age
Get PDFWith biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more ‘difficult’ taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively
“I always feel like I’m the first deaf person they have ever met:” Deaf Awareness, Accessibility and Communication in the United Kingdom’s National Health Service (NHS): How can we do better?
Get PDFBackgroundBarriers to communication significantly reduce access to health services for people with deafness or hearing loss (PDHL). These barriers contribute to reduced healthcare-seeking behaviour, poorer access to health information, and adverse health outcomes. In response, a multidisciplinary working group of patients, clinicians, researchers, and charity representatives was established to investigate accessibility, communication, and deaf awareness within the United Kingdom’s (UK) National Health Service (NHS).MethodologyA cross-sectional survey was conducted to explore the communication and accessibility experiences of PDHL NHS patients, and their perceived impact on well-being. The survey used rating scales and open-ended questions and data were analysed using descriptive statistics and thematic analysis. The survey was made available in British Sign Language (BSL).ResultsThe online survey was completed by 556 PDHL, including 50 parents, carers, or family members who had accompanied PDHL friends or relatives to NHS appointments. All respondents had used NHS services within the last 24 months, with 10% identifying BSL as their preferred language. Qualitative analysis of the open-ended responses generated three key themes: 1) Accessibility challenges, 2) Impact of communication difficulties across the service pathway, and 3) Lack of consistent, effective deaf-aware communication. Overall, 64.4% of PDHL NHS patients reported missing 50% or more of the important information provided during their NHS appointments, and 32% were satisfied with the communication skills of healthcare staff.ConclusionThis study presents the largest UK-wide dataset of its kind, and findings highlight the widespread non-compliance with the legally mandated Accessible Information Standards (AIS) within NHS services. The communication barriers identified in this study have significant and long-term implications for the well-being of PDHL patients. Utilising these findings, our working group has developed a set of ‘Recommendations For Change’ to improve deaf awareness and effective communication across the NHS
Missing the input: the underrepresentation of plant physiology in global soil carbon research
Get PDFPlant processes regulating the quantity and quality of soil organic carbon inputs such as photosynthesis, above- and below-ground plant growth, and root exudation are integral to our understanding of soil carbon dynamics. However, based on a bibliometric analysis including more than 55 000 scientific papers, we found that plant physiology has been severely underrepresented in global soil organic carbon research. Less than 10 % of peer-reviewed soil organic carbon research published in the last century addressed plant physiological processes relevant to soil carbon inputs. Similarly, plant physiology was overlooked by the overwhelming majority (>90 %) of the peer-reviewed literature investigating linkages between soil organic carbon, climate change, and land use and land management. These findings show that our understanding of both soil carbon dynamics and the carbon sequestration potential of terrestrial ecosystems is largely built on research that neglects the fundamental processes underlying organic carbon inputs. We maintain that the active engagement of plant scientists in soil carbon research is imperative for shedding light on this blind spot. Long-term interdisciplinary research will be essential for developing a comprehensive perspective of soil carbon dynamics and informing and designing effective policies that support soil carbon sequestration
Lianas reduce tree height with negative consequences for carbon storage and growth estimates
No full textCurrent evidence suggests that liana (woody vine) competition with trees could be threatening the carbon sink by reducing carbon uptake and storage in tropical forests. Previous studies investigating forest demography in liana removal experiments have, however, assumed similar allometries for trees, regardless of the amount of lianas they support. Yet, recent observations suggest that liana load may alter tree shape and structure, including height, which could result in an underestimation of the liana effects on forest carbon stocks and tree growth. In this study, we used terrestrial laser scanning (TLS) in a liana removal experiment in Gigante Peninsula, Panama, collected 11 years after removal to quantify the liana effect on tree height allometry. Furthermore, we assessed how the liana impact on tree allometry affects the estimates of carbon storage and sequestration. We fitted multiple tree height–diameter allometric relationships with a hierarchical Bayesian approach and combined the best resulting allometric model with inventories to estimate plot-level biomass stocks and their changes over time. For the same diameter at breast height, we found the trees to be 1.8 m shorter on average in the control plots compared to those in the removal plots, indicating a substantial liana effect on tree height. Converting these height differences through the use of allometric models and inventory data led to a reduction in tree biomass stock estimates in the control plots of 1.8 Mg C ha,−1 while they increased by 2.5 Mg C ha−1 in removal plots 10 years after removal. TLS-derived allometries led to estimates of tree biomass growth and tree biomass increment, respectively, 27.1% and 21.8% higher than when treatment-specific height allometries were not accounted for. Synthesis. The use of TLS in a unique experiment site provides strong experimental evidence that lianas change tree allometry, which has repercussions for estimating the capacity of forests to store and accumulate carbon. Our findings highlight the importance of accounting for liana-induced effects on tree shape and structure when using allometric equations to accurately estimate the impact of lianas on forest carbon dynamics
Investigation of the Effect of Thermal Shields on the Calcination of Petroleum Coke in Rotary Disc Kilns
Get PDFDue to various impurities, impure petroleum coke obtained during extraction processes is unsuitable for optimal use. The calcination process, commonly called coke baking, has gained considerable attention for its ability to purify coke and remove waste materials. Various devices and methods are available for coke calcination, among which the rotary disc kiln has been investigated in this study. This research aims to propose a simple numerical model for simulating heat transfer processes within a rotary disc kiln. It was observed that during the layer-by-layer baking of coke, the intense heat flux of the gaseous phase inside the kiln leads to a rapid temperature rise in the first and second coke layers. To address this, a novel thermal shield was introduced in this study to reduce the heat flux reaching the coke bed in the initial layers. Results demonstrated that applying a thermal shield reduced the coke bed temperature in the first and second layers by up to 8% and 52%, respectively, while maintaining the overall calcination process. Increasing the shield's thickness by 20% decreased the temperatures by 7% and 17% in these layers. The model also achieved an accuracy of less than 2% error compared to reference data, confirming its reliability. Additionally, using the shield reduced the refractory lining temperature by up to 7.74%, improving kiln durability and energy efficiency
Integrated energy storage and transmission solutions: Evaluating hydrogen, ammonia, and compressed air for offshore wind power delivery
Get PDFThis paper introduces a novel dual-purpose transmission system that integrates power transmission and energy storage using hydrogen, ammonia, and compressed air—an area largely unexplored in the literature. Unlike conventional cable transmission, which requires separate storage infrastructure, the proposed approach leverages the transmission medium itself as an energy storage solution, enhancing system efficiency and reducing costs. By incorporating a defined storage allocation factor, this study examines the delivery of offshore-generated power to onshore locations, calculating the necessary media flow rates and evaluating the required transportation infrastructure, including tunnels and pipelines. A comparative cost-effectiveness analysis is conducted to determine optimal conditions under which storage-integrated transmission outperforms conventional cable transmission. Various transmission powers, storage fractions, pressures, and distances are analysed to assess feasibility and economic viability. The findings indicate that for a 75 % storage allocation factor, compressed air can transmit up to 450 MW over 300 km more cost-effectively than cables, while hydrogen enables 230 MW transmission beyond 310 km. Ammonia proves to be the most efficient, facilitating the transmission of over 2000 MW across distances exceeding 140 km at a lower cost than cables, all without requiring onshore storage. Moreover, for a 500-km transmission line, compressed air, hydrogen, and ammonia can store the equivalent of 62, 58, and 152 h of wind farm output, respectively, significantly reducing the need for additional onshore storage. This study fills a critical research gap by optimizing offshore wind power delivery through an innovative, cost-effective, and scalable transmission and storage approach
Establishing a core domain set for early-phase clinical trials of electrical stimulation interventions for tinnitus in adults: an online Delphi study
Get PDFTinnitus is the awareness of sound in the ear or head in the absence of an external source. It affects around 10%–15% of people, and current treatment options are limited. Experimental treatments include various forms of electrical stimulation of the brain. Currently, there is no consensus on the outcomes that should be measured when investigating the efficacy of this type of intervention for tinnitus.Objective This study sought to address this issue by establishing a core domain set: a common standard of what specific tinnitus-related complaints are critically important to assess in all clinical trials of electrical stimulation-based interventions for tinnitus.Design A two-round Delphi survey was conducted, followed by a stakeholder consensus meeting to identify a core domain set.SettingAll data collection took place onlineParticipants Participants represented one of two stakeholder groups: patients with lived experience of tinnitus and professionals with relevant clinical, commercial or research experience.Results Stakeholders achieved consensus on the inclusion of ability to ignore, concentration, treatment satisfaction, helplessness (lack of control) and tinnitus intrusiveness in the core domain set, in addition to adverse effects.Conclusion This study established a core domain set for the evaluation of electrical stimulation-based interventions for tinnitus via an e-Delphi study. This core domain set will act as a minimum standard for reporting in future clinical trials of electrical stimulation interventions for tinnitus. Standardisation will facilitate comparability of research findings
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