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Geographic origin and post-invasion genetic divergence of Mytilus galloprovincialis in China
Get PDFBiological invasions serve as natural experiments to investigate how species adapt to novel environments. The Mediterranean mussel (Mytilus galloprovincialis), a highly successful marine invader and strong biofouler, has formed dominant populations along the coast of China. However, its genetic origin, population structure, and the consequences for the genetic diversity of invasive and native populations remain unclear. To address this, we employed a 60 K SNP array to genotype 320 individuals sampled from seven geographic populations, along with 112 reference samples. The results indicate a clear genetic affinity between Chinese and Mediterranean populations (FST < 0.05), while moderate differentiation was observed from Atlantic populations (FST > 0.05), supporting a Mediterranean origin. Genetic differentiation was observed in Dalian, whereas Lianyungang served as a key gene flow sink from both Mediterranean origins and nearby invasive populations. Moreover, using just 20 SNPs with a Support Vector Machine (SVM) model yielded 84 % classification accuracy, closely matching the full array's performance. Our findings provide novel insights into the invasion history and post-invasion genetic dynamics of M. galloprovincialis in East Asia and highlight the utility of SNP tools for species identification, population monitoring, and pollution-related biomonitoring in marine ecosystems.</p
Two-stage transfer learning for airborne multi-spectral image classifiers
Get PDFIn this work, we propose a novel training paradigm designed to support transfer learning for more effective classification in multispectral airborne imagery. Current state-of-the-art approaches typically rely on either leveraging solely RGB (red-green-blue) pretraining or applying in-domain transfer learning for multispectral imagery classification. Instead, our approach constructs and trains two separate neural network models (backbones): one specifically for wavelengths with available pretrained data (like visible bands) and another trained from scratch on all-bands available in the dataset. These models are then integrated with a fully-connected layer or multi-layered perceptron, which is trained on the features from both networks. This allows us to exploit the significant benefits of generalizable features learned from RGB datasets and the information provided by the full spectrum of multispectral bands. We employ the BigEarthNet and EuroSAT datasets, encompassing Sentinel-2 satellite imagery in the visual and infrared bands. This approach yields considerable performance gains in comparison with other training strategies across every evaluation metric we utilized for these datasets. The results are also consistent across a variety of backbone architectures, underlining the efficacy of our transfer learning technique in the analysis of multispectral data
Origins and fate of polycyclic aromatic hydrocarbons (PAHs) in sustainable drainage systems (SuDS) in a Scottish urban area: Implications for groundwater systems
Get PDFIncreasing urbanisation and the effects of climate change have resulted in a decrease in water quality and availability worldwide. At the same time, flooding in urban areas has become one of the most prevalent natural disasters worldwide. Sustainable drainage systems (SuDS) are resilient stormwater management solutions that can help reduce flooding by mimicking natural drainage processes and promoting infiltration. Numerous studies have focused on the benefits SuDS provide. But, to date, studies fail to investigate the risks that detention basins pose to groundwater quality, particularly the potential for infiltration of stormwater pollutants such as polycyclic aromatic hydrocarbons (PAHs). To address this important knowledge gap, this study combines gas chromatography–mass spectrometry (GC–MS) techniques for PAHs characterisation with numerical modelling tools to investigate organic pollutant infiltration patterns. We find that high levels of PAHs originating from urban areas are temporarily stored in SuDS basins and are likely to reach shallow water tables within one year. Multiple factors such as vegetation, precipitation, drainage area size, total organic carbon content in the soil and soil saturation influence the PAHs infiltration rates within the basins. More broadly, this study highlights the need for more research regarding SuDS dynamics to prevent both flooding and groundwater deterioration
Behaviour and design of sheathed light gauge steel panels subjected to in-plane shear and gravity loads
Get PDFThe in-plane shear behaviour of sheathed light gauge steel wall panels is investigated by tests on 2.4 m square wall panels together with push-out tests, to determine the shear fixing stiffness and resistance. Parameters such as sheathing material, screw geometry, stud arrangement, adhesives, combined bracing with sheathing boards, and profiled sheeting were considered. An X-braced panel was used as a benchmark and to interpret the forces in the bracing obtained from measured strains. Wall panels with single C- and back-to-back C- sections in the middle of the panel have equivalent shear stiffness and resistance. The use of non-winged fixings can significantly enhance the stiffness of the panel due to increased thread engagement with the board material. Adhesives on the board-frame interface reduce damage evolution on the board material, while significantly increasing both stiffness and resistance. The tests also included the combination of X-bracing and sheathing boards to determine how their stiffnesses may be combined. It was also shown that profiled steel sheets serve as a potential alternative to X-bracing, although they require more fixings. The design approach based on elastic theory for the fixing properties obtained from push-out tests is in close agreement with the test results obtained from the representative wall panel tests, where the ratio of the recorded to the predicted panel shear stiffness and resistance have an average of 1.03 and 1.05, respectively, with a variation of up to 8 %.</p
EARLY LIFE ENRICHMENT AND CHICK BEHAVIOR : The effect of light during incubation and dark shelter enrichment on chick growth and behavior
Get PDFEarly-life conditions can influence chick development and welfare. In this study, we investigated the effect of light exposure during incubation, and a post-hatch dark shelter enrichment, on layer chick growth and behavior. White Leghorn chicken eggs were incubated under either full-spectrum white light (24L:0D) or darkness (0L:24D) in temperature-compensated photoperiodic boxes. After hatching, chicks were reared in either standard pens or pens with a dark shelter enrichment. The study was conducted using four cohorts of chicks, resulting in eight replicates per treatment combination. All cohorts were used to assess chick growth; three cohorts were used to measure behavioral time budgets and interaction with the dark shelter, and the final cohort was used to examine behavior while inside the dark shelter. Chick behavioral time budgets and dark shelter use was continuously recorded via video over four weeks and quantified. Hatching success was not affected by light during incubation but there were age- and sex-specific effects on body weight by four weeks, female chicks incubated under light, tended to be heavier than those incubated under dark conditions. The dark shelter enrichment reduced overall chick activity and foraging while increasing resting behavior, with effects dependent on incubation treatment and age. In response to enrichment, light-incubated chicks showed decreased activity and foraging, and increased resting, compared to dark-incubated chicks. In contrast, in standard pens, light-incubated chicks were more active and foraged more than dark-incubated chicks. Our novel findings show that light exposure during incubation shapes early-life behavior in layer chicks and modulates their responses to dark shelter enrichment. Further research is required to determine whether lighted incubation and post-hatch dark shelter enrichment improve layer pullet long-term welfare
Innovative multichannel reactor design for solid-state hydrogen storage: A comprehensive study of Mg2Ni, LaNi5, and ZrCo performance
Get PDFHydrogen is increasingly recognized as a pivotal clean and sustainable energy carrier; however, its efficient storage, particularly in solid-state systems, remains a major technological challenge. This study presents a comprehensive investigation into the thermal and hydrogen absorption performance of three metals, Mg2Ni, LaNi5, and ZrCo, within a novel multichannel reactor design optimized for solid-state hydrogen storage. Using Computational Fluid Dynamics (CFD) simulations in COMSOL 6.2, the effects of key operational parameters, including cooling configurations, hydrogen supply pressure, heat transfer fluid's Re number, and material (reactor body) properties, on heat transfer and hydrogen absorption were systematically evaluated. The results demonstrate that Mg2Ni outperforms LaNi5 and ZrCo, exhibiting higher hydrogen absorption efficiency, faster cooling, and shorter saturation times. Moreover, increases in Re number and hydrogen supply pressure significantly enhance both heat transfer and absorption rates. The study also highlights the importance of reactor geometry in achieving effective thermal management. These findings offer valuable insights into the design of next-generation hydrogen storage systems, emphasizing the need for innovative reactor configurations to support the transition to a hydrogen-based energy
Joint Modelling of Line and Point Data on Metric Graphs
No full textMetric graphs are useful tools for describing spatial domains like road and river networks, where spatial dependence act along the network. We take advantage of recent developments for such Gaussian Random Fields (GRFs), and consider joint spatial modelling of observations with different spatial supports. Motivated by an application to traffic state modelling in Trondheim, Norway, we consider line-referenced data, which can be described by an integral of the GRF along a line segment on the metric graph, and point-referenced data. Through a simulation study inspired by the application, we investigate the number of replicates that are needed to estimate parameters and to predict unobserved locations. The former is assessed using bias and variability, and the latter is assessed through root mean square error (RMSE), continuous rank probability scores (CRPSs), and coverage. Joint modelling is contrasted with a simplified approach that treat line-referenced observations as point-referenced observations. The results suggest joint modelling leads to strong improvements. The application to Trondheim, Norway, combines point-referenced induction loop data and line-referenced public transportation data. To ensure positive speeds, we use a non-linear link function, which requires integrals of non-linear combinations of the linear predictor. This is made computationally feasible by a combination of the R packages inlabru and MetricGraph, and new code for processing geographical line data to work with existing graph representations and fmesher methods for dealing with line support in inlabru on objects from MetricGraph. We fit the model to two datasets where we expect different spatial dependency and compare the results
Parallel journeys:Exploring the lived experience of pregnant women with alcohol/substance use problems in Scotland
No full textBackgroundThe impact of prenatal alcohol and/or substance use on fetal development is well established. While past research has sought to better understand the experiences of individuals affected by such fetal exposures, less is known about the experiences of pregnant women themselves. The current study therefore aimed to examine their lived experiences of accessing services, perceptions of risk, stigma, and how women make sense of this journey as they transition into motherhood.MethodsSemi-structured interviews were conducted with six pregnant women, engaged with a specialist substance misuse midwifery service in Scotland. Data were analyzed using Interpretive Phenomenological Analysis (IPA), finding three super-ordinate themes and associated subthemes.ResultsParticipants discussed complex life histories, including trauma, domestic violence, and mental health challenges. Cultural norms surrounding alcohol and substance use were highlighted as complicating recovery and, for some, exacerbated prenatal substance use. Pregnancy was however considered a turning point; a circumstance that enabled sustained engagement with services and provided motivation for initiating recovery. For those continuing to use, their experiences were often characterised by feelings of guilt, worry, and disappointment. All participants described experiencing stigma and judgement, which in turn increased mistrust and created barriers to recovery, accessing care, and recovery.ConclusionFindings underpin the importance of non-judgmental and trusting relationships with professionals in promoting service engagement. Recommendations include integrating care models and improving access to recovery resources tailored for the pregnancy period. Addressing societal stigma remains critical to improve the outcomes for pregnant women with substance use dependencies
Risks of major arterial and venous thrombotic diseases after hospitalisation for influenza, pneumonia, and COVID-19: A population-wide cohort in 2.6 million people in Wales
Get PDFObjective: Pneumonia, influenza, COVID-19, and other common infections might increase the risk of thrombotic events acutely through an interaction between inflammation and the thrombotic system. The long-term risks of arterial and venous thrombotic events following hospitalisation for COVID-19 and hospitalisation for pneumonia or influenza are unclear. Materials and methods: In a population-wide cohort of linked Welsh health data of adults, we calculated the incidence of arterial and venous thrombosis after hospitalisation for COVID-19 (2020−2021). We then compared this post-hospitalisation incidence with the incidence prior to COVID-19 hospitalisation in the same individuals, and with the incidence in individuals who were never hospitalised for COVID-19. We then repeated this analysis for hospitalisation for pneumonia or influenza in a separate cohort (2016–2019). We estimated adjusted hazard ratios (aHRs) in separate time periods starting from the date of the first infection that resulted in hospitalisation (day 0, 1 to 7 days, 2 to 4 weeks, 5 to 16 weeks, and 17 to 75 weeks) using time-varying Cox regression. Confounders included age, sex, smoking status, obesity, deprivation (fifths of Welsh Index of Multiple Deprivation), rural or urban setting, care home attendance, Elixhauser comorbidity index, surgery in the last year, medications (e.g. lipid-lowering and antiplatelet/anticoagulant use), hypertension and/or hypertensive medication use, and past medical history of chronic kidney disease, diabetes, chronic obstructive pulmonary disease, dementia, cancer, or any CVD. Results: For the first arterial thrombosis, the aHRs were 3.80 (95 % CI: 2.50–5.77) between days 1–7, 5.24 (4.21–6.51) between weeks 2–4, 2.12 (1.72–2.60) between weeks 5–16, and 1.60 (1.38–1.86) between weeks 17–75 after hospitalisation for COVID-19. The corresponding aHRs after hospitalisation for pneumonia/influenza were: 5.42 (4.35–6.75), 3.87 (3.32–4.49), 1.96 (1.74–2.21), and 1.41 (1.30–1.53). For first venous thrombosis, aHRs were 7.47 (3.56–15.7) between days 1–7, 22.6 (17.5–29.1) between weeks 2–4, 6.58 (4.98–8.68) between weeks 5–16, and 2.25 (1.67–3.02) between weeks 17–75 after hospitalisation for COVID-19. The corresponding aHRs after hospitalisation for pneumonia/influenza were: 15.1 (10.3–22.0), 11.8 (9.23–15.1), 5.80 (4.75–7.08), and 1.89 (1.57–2.29). Excess risk was highest in individuals aged ≥60 years, in whom we estimated 2,700 and 2,320 additional arterial and 1,270 and 840 additional venous events after 100,000 hospitalisations for COVID-19 and pneumonia/influenza, respectively. Conclusions: Both hospitalisation for COVID-19 and pneumonia/influenza increase the risk of arterial and venous thrombosis. Preventative healthcare policies are needed for cardiovascular risk factor management, vaccination, and anticoagulation in high-risk patients with hospitalised or severe infections.</p
Public and professional stakeholders’ perceptions of alcohol advertising and availability policies: A qualitative study
No full textIntroductionReducing alcohol availability and restricting alcohol advertising are effective ways to reduce harm from alcohol. Implementation of public health policies involves collaboration between different stakeholders, and is influenced by public opinion. This paper explores public and professional stakeholders' perceptions of alcohol advertising and availability policies. It is the first to capture consensus and divergence in narratives of these stakeholders.MethodsWe conducted semi-structured interviews with 14 stakeholders from third sector organisations, government, public health and alcohol licensing in Scotland. We conducted 11 online focus groups with 45 participants, living in neighbourhoods in Scotland characterised by varying levels of urbanity, deprivation and retail density change. We gave participants a list of policies and discussed their views on acceptability, feasibility and likely success.ResultsDespite general consensus that regulation of alcohol advertising is an important priority, public stakeholders were concerned about the feasibility of advertising interventions and potential unintended consequences. While professional stakeholders were in favour of regulating alcohol availability, public stakeholders had misgivings about feasibility and effectiveness. When prompted to discuss specific interventions, similar views about protecting children and achieving cultural change emerged.Discussion and ConclusionsThis study highlights the importance of policy makers and other stakeholders to consider public stakeholders' opinions on alcohol policy and understanding that their views may be influenced by competing framings of alcohol problems. Attempts to increase support for alcohol control policies need to consider people's concerns about the effectiveness and potential unintended consequences of these policies, and the wider social context of alcohol consumption
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