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Trophic interactions and climate-driven range dynamics of native and invasive catfish in freshwater ecosystems
Get PDFInvasive species and climate change are among the most significant drivers of biodiversity loss in freshwater ecosystems, yet their combined effect on predator-prey dynamics remains insufficiently characterised. Here, we assess the trophic interactions and climate-driven range dynamics of two large-bodied catfish—the non-native African catfish, Clarias gariepinus and the native Wels catfish, Silurus glanis—in a thermally stable freshwater system in Türkiye. Using comparative functional response experiments and stable isotope analysis, we quantified predation patterns on a native prey species, Alburnus escherichii and a widespread non-native prey, Carassius gibelio. Both predators exhibited feeding efficiency on the native prey, with C. gariepinus demonstrating consistently greater consumption rates and potential ecological impact, particularly under warmer conditions. Ecological niche models projected range expansion for both catfish species under future climate scenarios, with increasing habitat overlap that may elevate the likelihood of interspecific interactions and exacerbate predation pressure on native fish communities. Our findings demonstrate how warming conditions can reinforce the ecological impacts of an invasive predator while altering its spatial interactions with native species, underscoring the urgent need to integrate experimental, field-based, and modelling approaches to anticipate climate-amplified invasion risks in freshwater ecosystems
Quality over quantity: focusing on high-conflict trials to improve the reliability and validity of attentional control measures
Get PDFIn conflict tasks, congruency effects are thought to reflect attentional control mechanisms needed to counteract response conflict elicited by incongruent stimuli. Although congruency effects are well-replicable experimentally, recent studies have evidenced low correlations between congruency effects measured across different paradigms, leading to a heated debate over whether these low correlations indicate a lack of construct validity or are rather attributable to high measurement error, as indicated by the poor reliability typically displayed by congruency effects. In the present study, we investigated whether the poor reliabilities of congruency effects are due to their poor theoretical specification. Specifically, we tested whether the psychometric properties of congruency effects can be improved by focusing exclusively on those trials in which response conflict is theoretically expected to be highest. We considered two factors modulating the degree of response conflict: previous trial congruency, with higher conflict following congruent trials, and the time elapsed since stimulus onset, with higher conflict in fast responses. Data from 195 participants completing a Simon and a spatial Stroop paradigm showed that generally poor split-half reliabilities for the full set of trials improved greatly when excluding postincongruent and slow trials. Importantly, between-task correlations also increased substantially when controlling for these factors, suggesting that, with increased reliability, these tasks capture common attentional control ability. Our results suggest that individual differences in conflict tasks can provide valid and reliable measures of inhibition as a major component of attentional control when focusing on the trials with the theoretically highest response conflict
Cardiac Ultrasound Video Generation Using a Diffusion Model with Temporal Transformer
Get PDFCardiac ultrasound is widely used for the diagnosis and monitoring of cardiovascular diseases due to its noninvasive nature, real-time imaging capability, and low cost. However, its clinical utility is often limited by noise sensitivity and acquisition variability, which adversely affect automated interpretation and sequence consistency. To overcome these limitations, this paper presents a multimodal deep learning framework that combines a denoising diffusion model with a Temporal Transformer to generate high-quality cardiac ultrasound videos. A unified preprocessing pipeline with intensity normalisation and standardisation is employed to reduce intersample variation and enhance anatomical structures. Spatial features are first extracted from individual frames, followed by temporal modelling across sequences using the Temporal Transformer. These features guide the latent-space denoising process, optionally augmented by ControlNet for structure-aware generation. The experimental results demonstrate that the proposed method achieves robust performance, with an FID of 43.50, an FVD of 274.52, and an inception score of 8.62. Ablation studies further verify the critical contributions of ControlNet and composite loss design, highlighting the effectiveness of the framework in ensuring both spatial fidelity and temporal coherence
KCLVA: Knowledge-enhanced Contrastive Learning and View-specific Attention for Chest X-ray Report Generation
Get PDFIn clinical scenarios, radiologists analyse multiple chest X-ray (CXR) images from various view positions to identify diseases and abnormalities. To replicate the diagnostic approach of experienced radiologists, we propose an encoder-decoder-based CXR report generation architecture, KCLVA, which leverages the Unified Medical Language System (UMLS) to extract view-specific information from diagnostic reports, focusing on posteroanterior, anteroposterior, and lateral views. This extracted information facilitates view-specific attention (VA) mechanisms and is subsequently used to construct a similarity matrix that enables many-to-many contrastive learning. In the encoder, we employ a knowledge distillation architecture to guide the learning of the student model by freezing the teacher model. Within the student text encoder, the VA mechanism is utilised to automatically assign higher weights to tokens corresponding to a specific view in diagnostic reports based on the view position of the CXR, while assigning lower weights to other tokens. The image and text features are then integrated using contrastive learning. In the decoder, a transformer-based backbone architecture is employed to decode the encoder output and generate a medical diagnosis report. This strategy leverages UMLS to extract view-specific information, employs VA to adjust token weights, and utilises many-to-many contrastive learning through a weighted contrastive loss. Together, these components enable our model to closely simulate the diagnostic process of professional radiologists. Consequently, our method achieves significant improvements of 0.185 on METEOR and 0.078 on ROUGE compared to previous approaches
Police innovation and institutional entrepreneurs: the emergence of police drug diversion schemes in England and Wales
Get PDFThis article advances knowledge about the initiation of police innovation in the context of drugs policing. Drawing on the findings of a qualitative research project, it provides an original account of the emergence of police drug diversion schemes in England and Wales by analysing the complex interactions between individual, organisational and environmental determinants. The concept of institutional entrepreneurship is applied to examine the role of diversion entrepreneurs in the innovation process. These are the key police actors behind local schemes who had an interest in changing the institutional status quo. Diversion entrepreneurs wove together various forms of knowledge to frame problems and persuade stakeholders that diversion would address policing priorities and reduce demand by reducing reoffending and the resources needed to deal with people caught committing minor drug-related offences. Police budget cuts had created fertile ground for diversion as police organisations were leaning towards more proactive styles of policing which focus on prevention by addressing the underlying causes of crime. Making the case for diversion also required diversion entrepreneurs to highlight the shortcomings of existing practices and present diversion as a viable alternative to traditional enforcement interventions that seek to tackle drug problems through criminal sanctions. This involved interpretive struggles over the police role and managing perceptions of risk. It is argued that police scholars should pay closer attention to institutional entrepreneurship within police organisations to enhance understanding of processes of innovation and cultural change
Relational Egalitarianism and Warranted Stigma
No full textRelational egalitarians oppose social hierarchy. Or, more precisely, they oppose intolerable social hierarchy. Stigma is often included among those unequal forms of relating that relational egalitarians ought to oppose, but there are circumstances in which stigmatizing behaviors or group identities might be strategically important for opposing social inequalities. Working through different responses to this puzzle, in this paper I advance the view that stigma is neutral, such that relational egalitarians should only oppose forms of it that are unwarranted
Adhesive layer formation and its dual role in tribological performance and surface integrity of Ti-6Al-4V: Implications for the machining process
Get PDFThe poor machinability of Ti-6Al-4V (Ti64), characterized by adhesive and abrasive wear, low thermal conductivity, and high chemical reactivity, continues to hinder efficient manufacturing. Among these challenges, adhesive layer formation on tool flank faces remains poorly understood despite its critical influence on tool degradation and workpiece surface integrity. To address this, this study investigates the tribological behavior of WC/Co-Ti64 pin-on-disc sliding contacts under dry and minimum quantity lubrication (MQL) conditions through both experimental and numerical approaches. Experimental results show that thick, stable, and intact adhesive layers transferred from Ti64 discs was formed on WC/Co pin surfaces under dry and low MQL flowrate conditions. These layers are associated with reduced friction coefficients and lower disc wear but simultaneously contribute to compromised surface integrity. Comparative boundary element method (BEM) simulations with 316 L stainless steel reveal that the lower elastic modulus of Ti64 adhesive layers significantly reduces nominal contact pressure and subsurface von Mises stress, lowering friction coefficients and enhancing mechanical stability of adhesive layer. However, the accompanying increase in surface roughness intensifies local stress concentrations and result in thicker work-hardened layers on Ti64 disc, which align well with BEM simulation results. Conversely, high MQL flowrate inhibited adhesive layer formation, leading to higher friction and wear but producing smoother surfaces and thinner work-hardened layer. The findings offer new mechanistic insights into complex interplay between adhesive layer, lubrication and surface topography, and present the first direct evidence of the dual role of adhesive layer: reducing friction and tool-side wear but compromising workpiece surface integrity
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