Significant progress has been made in disease progression modelling, with crucial implications for understanding and managing chronic, progressive diseases, such as neurodegenerative diseases. One prominent framework is Subtype and Stage Inference (SuStaIn), an event-based machine learning model that characterizes disease progression and can reveal spatiotemporal and phenotypic heterogeneity in chronic diseases using only cross-sectional data. SuStaIn has demonstrated success across neurodegenerative, psychiatric, and pulmonary diseases. However, a key limitation of SuStaIn is its assumption of monotonic disease progression, which may be biologically implausible and clinically restrictive, particularly for diseases that commonly involve remission and recovery (e.g., psychiatric disorders). To examine the impact of this assumption, this proof‑of‑concept study systematically evaluated SuStaIn’s performance on non‑monotonic data. We generated both monotonic and bidirectional ground-truth disease progression datasets. The bidirectional datasets were further manipulated across sample sizes, numbers of biomarkers, and subtype proportions. Model performance was evaluated using Kendall’s tau to compare the inferred event sequences with the ground-truth progression. Results show that SuStaIn performs significantly worse on datasets with bidirectional underlying disease progression than on baseline monotonic datasets. While SuStaIn reliably captures the number of subtypes and their proportions, it fails to accurately model progression within subtypes that contain switch biomarkers. Moreover, increasing the sample size and the number of biomarkers does not substantially improve performance under bidirectional conditions, in contrast to monotonic progressions. These findings provide empirical evidence that SuStaIn’s monotonic assumption limits its ability to model bidirectional disease processes, as in many psychiatric disorders. More broadly, this work deepens the understanding of SuStaIn as an event-based model and informs future methodological extensions to relax the monotonic progression constraint.
IL-37 is a member of the IL-1 cytokine family and functions as a broad anti-inflammatory mediator through suppression of pro-inflammatory cytokines and modulation of immune signaling pathways. Uniquely, IL-37 signals through both extracellular receptor-mediated mechanisms (IL-18R1 and IL-1R8 (SIGIRR)) and intracellular pathways (SMAD3-mediated nuclear translocation) that broadly reduce inflammatory pathway activation. The protective effects of IL-37 in EAE occur through its extracellular function, specifically binding IL-1R8, thereby inhibiting pro-inflammatory signaling cascades such as NF-κB, MAP kinases, and mTOR pathways. IL-37 has been studied in cardiovascular endothelial cells, where it inhibits atherosclerosis, reduced endothelial apoptosis, and protects against coronary endothelial damage, suggesting therapeutic potential in inflammatory endothelial pathologies. However, the expression and function of IL-37 in human brain endothelial cells remains poorly characterized. These cells are implicated in Multiple sclerosis (MS), a chronic neuroinflammatory disease affecting around 2.9 million people worldwide. The disease results from immune cell infiltration across the blood-brain barrier (BBB), which disrupts neuronal signalling by promoting inflammation, demyelination, gliosis and neuroaxonal degeneration. Transgenic mouse studies that introduced IL-37 in experimental autoimmune encephalomyelitis (EAE), the standard animal model for MS, demonstrated significantly reduced clinical scores and decreased demyelination. In addition, IL-37 expression reduced immune cell accumulation in the spinal cord and shifted cytokine profiles toward a more anti-inflammatory phenotype.Because human brain endothelial cells regulate immune trafficking and inflammatory signaling at the BBB and are associated withMS pathology, this project aims to investigate IL-37 signaling in human brain endothelial cells and determine whether this pathway contributes to immune regulation at the BBB. Understanding IL-37 in this context may provide insight into mechanisms that limit neuroinflammation in MS and identify potential therapeutic targets.
Punctate white matter lesions (PWMLs) are common in preterm neonates and linked to adverse neurodevelopmental outcomes. Conventional identification relies on subjective visual contrast on MRI. We propose a global, training-free z-score normalization framework for automatic PWML detection, enabling standardized, interpretable segmentation across modalities without machine learning or subject-specific calibration. We analyzed 44 neonates from the dHCP dataset, comprising 1069 axial slices from T1w, T2w, and mean diffusivity (MD) maps. Reference masks were generated by consensus among four trained raters. Slices within each modality were standardized to a global z-score space, allowing comparable intensity distributions. For each modality, a detection threshold of z-score was swept from -3 to 3 standard deviations to construct receiver operating characteristic (ROC) curves. Lesion–white matter contrast ratios (CR) were also computed. Inter-rater reliability (Cohen’s k) reached 0.88 for T1w, 0.77 for T2w, and 0.73 for MD. PWML–white matter contrast differences were statistically significant (p < 0.01). Contrast magnitude was greatest for T1w (CR = 0.57 ± 0.19), compared to T2w (-0.18 ± 0.08) and MD (-0.14 ± 0.12). ROC analysis revealed that T1w outperformed the other modalities, achieving an AUC of 0.98 at an optimal threshold of 0.84 (True Positive Rate = 0.90, False Positive Rate = 0.06). In contrast, T2w and MD achieved lower AUCs of 0.84 and 0.67, respectively. Global z-score normalization yields a robust, fully automatic lesion detection method. This interpretable baseline achieves high sensitivity with minimal false positives and provides a reproducible benchmark for evaluating deep-learning or quantitative MRI pipelines.
In order to properly function, the immune system must achieve a fine balance between attacking foreign invaders while avoiding damage to healthy (self) tissue. One way it maintains this balance is through the induction of T cell anergy. Anergy is a key tolerance mechanism that renders self-reactive T cells hyporesponsive, thereby preventing the development of autoimmune diseases. T cell anergy is typically induced under steady state conditions when antigen recognition occurs without co-stimulation, such as in the absence of inflammation. Regulatory T (Treg) cell-mediated suppression of self-reactive T cells may contribute to anergy induction, but their specific role remains poorly defined. In this study, we investigate how antigen-specific Tregs influence the generation and accumulation of anergic CD8 T cells in vivo. To test this, we generated Tregs ex vivo from OVA-specific OT-II CD4 T cells. We injected OVA-specific OT-I CD8 T cells with or without OT-II Tregs into mice expressing OVA as a model self-antigen. After fourteen days, we observed an increase in the proportion of OT-I T cells in the spleen of mice co-adoptively transferred with OT-II Tregs as compared to mice injected with OT-I T cells alone. We confirmed, via ex vivo re-stimulation, that OT-I T cells induced in the presence of OT-II Tregs remained anergic. Interestingly, single-cell RNA-sequencing revealed that levels of antigen-specific Tregs correlate with transcriptional heterogeneity among anergic CD8 T cells in vivo. These findings suggest that antigen-specific Tregs promote the accumulation of anergic CD8 T cells. This work contributes to a broader effort to define mechanisms of peripheral tolerance, providing a foundation for their potential use in therapeutic interventions to prevent autoimmune disease.
Bipolar disorder is a chronic mental health condition defined by recurrent shifts in mood and impairment in cognitive functioning. Action-Based Cognitive Remediation (ABCR), originally developed for schizophrenia-spectrum disorders, integrates cognitive exercises with real-world application strategies. The intervention consists of four modules that focus on improving speed and attention, memory, executive functioning, and social cognition. ABCR has shown preliminary promise for improving cognitive and functional outcomes in individuals with bipolar disorder. The aim of this preliminary study is to examine the effect of ABCR intervention on clinical mood symptoms and functioning using a linear mixed-effects model. Based on prior ABCR research using Reliable Change Indices (RCI) and relative percent change, pre-post changes in clinical symptoms were expected to be small. The linear mixed effects model was expected to provide a more informative estimation of these changes by accounting for individual variability and estimating the overall direction and magnitude of group-level change in a small sample. Ten participants (eight females, two males) from the External Clinic for Bipolar Disorders at the Douglas Mental Health Institute were recruited, with seven completing the seventeen-session videoconference intervention. Results indicate small, non-significant average changes across outcomes. Trend estimates suggested modest improvement in functioning, while depressive symptoms and quality of life showed minimal change at the group level. Although limited by a sample size, these findings demonstrate the value of mixed-effects models as a preliminary tool for estimating the overall trend in small clinical samples. Future work should integrate linear mixed-effects models with other measures such as Reliable Change Indices, to better capture improved clinical symptoms and cognitive functioning in patients with bipolar disorder.
During early embryogenesis, intracellular signals determine whether follicle cells differentiate towards anterior or posterior fate. Bone Morphogenetic Protein (BMP) is one of the regulatory proteins repressing mid, a transcription factor that induces the posterior pattern formation in Drosophila. BMP regulates mid expression by binding to the intron segment of the mid gene, known as mid-in. Previous work using the lacZ reporter in mid-in has shown that mid-,requires BMP expression in some cases, presenting a potential bi-functional role of BMP. We hypothesize that such a property might be determined by the availability of schnurri, a well-known co-repressor of BMP. We examined lacZ fused with mid-in in three groups of Drosophila, over expression of BMP, knock-down of schnurri, and the combination of both genotypes. Each group contained 40 samples and was analyzed using genetic mosaic analysis. We found that reporter expression decreased substantially when schnurri was present and BMP was over expressed. In contrast, the reporter was ectopically expressed when schnurri was absent and BMP signalling was overactivated. However, because schnurri was only knocked down using schnurri RNAi in this experiment, the activation phenotype was not strong. Future experiments could repeat this analysis using Drosophila with a schnurri gene mutation instead. Overall, these results demonstrate the bifunctional property of BMP pathway in the regulation of the mid-in reporter. Future work may focus on identifying the locations of the BMP activation and repression motif within the mid-in sequence.
[18F]fluorodexyglucose ([18F]FDG) is a glucose analog where the hydroxyl group in the C-2 position is substituted by the cyclotron-produced [18F] radionuclide. This radiopharmaceutical is used in medical imaging, particularly in positron emission tomography (PET) scans crucial in cancer diagnoses and monitoring. 18F-FDG synthesis involves a nucleophilic substitution with 2.2.2-Kryptofix as a phase-transfer catalyst. However, Kryptofix residue quantities must be strictly regulated due to their toxicity. Current quality control processes employ spot testing where sample colors are compared to that of a standard, which is prepared at maximal Kryptofix concentration of 0.5mg/V. This project aims to build a user-friendly interface able to determine whether a 18[F]FDG sample passes the Kryptofix concentration test through image analysis techniques. A Python-based application was developed using the “Tkinter” library to create a graphical user interface, integrated with image processing features. The software employs colorimetric analysis by quantifying pixel intensity and performing statistical comparisons on user-defined cross-sections of the image. Software validation is performed using images with known sample and standard concentrations. The user-friendly interface aims to improve accessibility and limit the subjectivity of human analysis for the determination of 2.2.2-Kryptofix contents in a sample and successfully determines the pass/fail status of the sample regarding regulatory safety standards of 0.5mg/V. The software generates reports documenting the analytical process, which are required for regulatory compliance and quality assurance documentation. These reports are crucial in the case of a test failure or deviation. Further improvements can be made to the software to quantify the Kryptofix concentration in [18F]FDG samples rather than provide only pass/fail data. The basic software architecture has also been adapted and modified to conduct other quality control tests in a radiopharmaceutical laboratory, with promising preliminary testing for bacterial colony counting and environmental monitoring.
Background: Urban alleyways are underexplored spaces of potential ecological and social significance. While green alleyways are promoted to improve environmental quality, their distribution relies on borough-level governance and community engagement. The extent to which structural alley availability and socioeconomic factors facilitate greening, and how greening influences social capital and inter-species connections, remains unclear. This study aims to map regular (non-green) alleys, quantify greening patterns, and provide a baseline for assessing associated social and ecological outcomes. Methods: Using QGIS, we mapped 1,348 regular alleys across four Montréal boroughs and recorded their greening status. 25 Quartiers de Référence were analyzed to examine relationships among alley quantity, density, median household income, and green alley prevalence. Analysis methods used included descriptive statistics, Pearson correlations, linear regression, and binomial regression. A follow-up cross-sectional study (REB pending) will assess bonding, bridging, and inter-species social capital among residents in green alleys, regular alleys, and non-alley areas. Results: On average, 22% of alleys were greened (range: 0–44%). Alley counts strongly predicted green alleys (r = 0.74), with moderate associations for density (r = 0.39) and income (r = 0.60). Linear and binomial models confirmed that higher alley availability, density, and income increased the likelihood of greening (p < 0.05). Limitations: Causal inference cannot be made; greening may reflect pre-existing community engagement. Social capital outcomes await REB approval. Conclusion: Higher number and density of regular alleys encourage alleyway greening. Future analyses will clarify whether green alleyways correlate with community cohesion or environmental engagement.
Crayfish play a crucial role as ecosystem engineers in freshwater ecosystems, yet they remain poorly represented in ecological studies. Integrating aquatic invertebrates into biodiversity monitoring efforts is urgentlyneeded, particularly given their important ecological role as indicators of freshwater ecosystem health. The purpose of this pilot study was to record crayfish presence in the Gault Nature Reserve and to characterize species identity, morphology, and dorsal colouration of individuals from two habitats sampled (Lake Hertel and a nearby stream), with colouration assessed for substrate matching. This study records the occurrence of two crayfish species in the Gault Nature Reserve of McGill University and examines their morphological and colouration differences. Two species of crayfish were identified: the Virile crayfish (Faxonius virilis) in Lake Hertel and the Appalachian Brook crayfish (Cambarus bartonii) in a nearby stream. A key outcome of this pilot survey is the identification of different crayfish species living in different habitat types within the reserve. This finding demonstrates the necessity of broader biodiversity surveys of freshwater species in Gault. Morphometric analyses showed significant size differences between species aligning with ecological differences observed between the two site-specific species, though these disparities likely reflect species–specific traits more than habitat effects alone, which could not be isolated in this study design. Colouration analyses did not support the hypothesis that crayfish colouration matches substrate colours for camouflage. The analysis of colouration is considered exploratory and must not be considered a conclusive test of substrate matching because of the failure of photographic colour extraction to match colouration and the absence of consideration of body size sex, and developmental stages. Future research should incorporate more controlled colour assessments, expand the survey area, and conduct genetic analyses and transplant experiments to clarify whether colouration and morphology are determined by environmental or genetic factors.
Exposure to plastic nanoparticles has been investigated since the late 1980s and has become a growing public health concern over recent years. Among these concerns are their potential impact on fertility and reproduction, as the small size of plastic nanoparticles allows for their entry into the systemic circulation and translocation across the placental barrier, potentially affecting and disrupting reproductive processes. This literature review aims to examine how gestational exposure to plastic nanoparticles and the substances they carry can influence or alter maternal behaviour, progeny outcome, and sex ratio. We hypothesized that gestational exposure to plastic nanoparticles disrupts neuroendocrine pathways regulating maternal behaviour and offspring development. After synthesizing data from in vitro and in vivo studies in PubMed, a comprehensive review of the current scientific literature was conducted. Overall, study findings suggest that nanoparticle exposure during pregnancy can reduce oxytocin levels in both the plasma and the hypothalamus, correlating with decreased observable maternal behaviours in affected mice. Additionally, adverse outcomes have been reported in exposed progeny, including thinning of the cerebral cortex in Sprague Dawley rats and transgenerational changes in population fitness in D. Magna plankton. Specific sex-based vulnerabilities were identified, with some studies suggesting a potential skewing of the male-to-female ratio, with male embryos being more severely impacted. However, current evidence more strongly implicates general environmental pollution rather than nanoparticles specifically. Moreover, contemporary scientific information is limited by a stronger focus on oxytocin. While the link between environmental pollutants and oxytocin is well-documented, other critical regulators of maternal behaviour, such as placental lactogen and prolactin, remain understudied and yield conflicting data regarding nanoparticle interference. The importance of this investigative literature review lies in the urgency to understand the mechanisms by which nanoplastics impact reproductive health, and to prevent the adverse effects of nanoparticle exposure on our ecosystems and our future generations.
Cryo-electron tomography enables three-dimensional visualization of macromolecular structures within intact cells. Filamentous structures such as microtubules are essential for intracellular transport, structural stability, and cell division. Structural analysis of microtubules often relies on subtomogram averaging, a process that requires manual or semi-manual filament picking and alignment. These steps are time-consuming, computationally demanding, and can introduce user bias, making it difficult to handle large datasets efficiently. We developed an automated pipeline for microtubule detection and particle orientation prediction to improve efficiency and consistency in subtomogram averaging workflows. The pipeline integrates filament tracing, line connection analysis, and geometric modeling to detect microtubules and predict particle angles prior to alignment. Quality control measures were incorporated to identify elliptical distortions, misaligned particles, and outliers in dense datasets. Performance was evaluated by comparing pipeline outputs with manually processed datasets, examining particle ordering, angular consistency, alignment behavior, resolution, and processing time. Automated picking preserved expected structural organization and produced angle predictions consistent with refined alignment parameters while reducing analysis time. However, performance may vary depending on tomogram quality and filament density. These findings demonstrate that automated filament detection can reduce manual effort and support efficient structural analysis in cryo-electron tomography. Further improvements may increase reliability across different cellular contexts.
The human hand is a pillar of the species’ distinction, a crucial orchestrator of the technological and cognitive adaptive niche that has shaped the modern world. Artifacts of morphological adaptations guiding transitions in early hominin evolution are present in the hand. As early hominins shifted from suspensory arboreal regimes to bipedalism, and from occasional tool-using to tool-making, the human hand adapted morphologically, leading to its current form. Conversely, the chimpanzee hand evolved within a primarily arboreal locomotive niche at the expense of optimization for tool-usage. Comparative studies can elucidate functional relationships that have shaped these changes. In this study, we aim to visualize the morphological adaptations present in the human hand in a non-destructive manner that can be applied to rare and valuable chimpanzee specimens. Using DragonFly software, we present a 3D reconstruction of an entire human hand, contrast-enhanced with phosphotungstic-acid. Additionally, we identified and segmented four unique morphological adaptations present in the human finger for advanced manual handling ability. These include the unique morphology of the distal phalanx, a strengthened flexor digitorum profundus insertion, increased neural innervation in the distal tip, and a compartmentalized digital pulp. This study precedes our upcoming application of the above on a chimpanzee fourth digit, and a future report of comparative sensory neural innervation, which is involved in sensorimotor feedback during tool-usage in both species but may be specialised in Homo sapiens.
Mucopolysaccharidosis type IIIC, also known as Sanfilippo syndrome type C, is a lysosomal storage disease caused by a deficiency of heparan sulfate acetyl-CoA: alpha glucosaminide N-acetyltransferase (HGSNAT). HGSNAT is one of the key enzymes involved in the degradation of heparan sulfate, a glycosaminoglycan present in proteoglycans and basement membranes. The absence of HGSNAT activity leads to an accumulation of heparan sulfate in lysosomes, causing cellular dysfunction and progressive neurological degeneration. This study examined the glomerular renal pathology in a CRISPR-Cas9-generated knock-in mouse model expressing the Pro304Leu HGSNAT variant, which replicates the human Pro311Leu mutation. The model showed early-onset MPS IIIC with dominant-negative effects and stress on the endoplasmic reticulum and lysosomes. Wild type (WT, n=3, 7 months old) and HGSNAT knock-in (KI, n=3, 7 months old) mice were used for each experiment. Kidneys were collected and processed for histological and ultrastructural analysis using light and electron microscopy. ImageJ was used to quantify the stained area of the mesangial matrix. Compared with WT, KI mice exhibited a more intense Periodic acid Schiff staining of the glomerular mesangial matrix, an accumulation of empty vesicles in the podocytes, distorted mesangial cells, and severely affected podocytes filled with lysosomes and enlarged pedicels. In conclusion, the increased deposition of heparan sulfate in the mesangial matrix is associated with glomerular distortion and mesangial proliferation, findings consistent with the development of mesangial proliferative glomerulonephritis.
Individuals with bipolar disorder (BD) have low employment rates, partly due to impaired cognitive performance. However, employment plays an important role in an individual’s sense of purpose and quality of life. For those with BD, employment has been associated with enhanced self-satisfaction and reduced psychiatric symptoms, which in turn are linked to increased self-esteem and improved mood, as employment can be viewed as attaining important goals. Goal attainment is also negatively correlated with self-stigma, as social cognitive performance may decline when individuals face stigmatizing scenarios in the workplace. There is a lack of understanding of the relationships among social cognition, self-esteem, and self-stigma in the context of employment. This study aims to examine these relationships in individuals with BD over a two-month period of employment-related observation. Twenty-two individuals with BD were recruited from the Douglas Institute outpatient clinic for mood disorders. Given that they were all employed, they underwent assessments measuring the quality of workplace interactions, as well as their social cognitive performance, self-esteem, and self-stigma. To test our hypotheses, a repeated-measures ANOVA will be conducted to evaluate the effect of time on social cognitive performance, self-esteem, and self-stigma. Correlation analyses and a mediation model will also be used to examine relationships between workplace interactions and these outcomes. It is hypothesized that self-stigma will decrease before there is an increase in self-esteem and social cognitive performance, along with the expectation that self-stigma and social cognition are correlated and that self-stigma will impact social cognitive performance.
Microtubules are dynamic polymers of α-β tubulin heterodimers that support cell structure and contribute to processes including cell division, intracellular transport, and cilia stability. Their functions are regulated by microtubule-associated proteins (MAPs), which influence assembly, stability, and interactions with other cellular components.. Accurate identification of the microtubule seam, where heterotypic α-β interactions replace homotypic α-α and β-β contacts, is essential for cryo-electron microscopy (cryo-EM) reconstruction. Current seam-alignment strategies employ kinesin motor domains that generate alignment contrast but mask lattice features and limit compatibility with many MAPs. The Bui lab identified Sperm Flagellar Protein 1 (SPEF1) as a seam-binding alternative, though its small size limits reliable visualization. We hypothesised that engineering larger SPEF1 fusion proteins would improve seam contrast and alignment while preserving microtubule binding. Fusion constructs were designed using RoseTTAFold Diffusion to append structured domains to the SPEF1 microtubule-binding region while preserving predicted folding and function. Constructs were cloned, sequence-verified, and expressed in Escherichia coli, with several designs demonstrating strong expression and yielding soluble protein after purification. Using a microtubule co-sedimentation assay, the engineered construct SPEF1 (1-120)-300AA demonstrated effective binding to polymerized microtubules, supporting its suitability for further microtubule seam-targeting studies, although cryo-EM validation remains ongoing. These results position engineered SPEF1 fusion proteins as promising seam-alignment tools that provide a broadly compatible and experimentally validated strategy for advancing cryo-EM studies of microtubule architecture and enabling direct evaluation of seam localization without masking lattice features or disrupting lattice-binding protein interactions, thereby overcoming limitations imposed by existing seam-alignment strategies.
Gene regulatory factors (GRFs) are essential regulators of human phenotypic diversity. Among these, MAMLD1 acts as a transcriptional co-activator critical for male genital development. Mutations in MAMLD1 are clinically associated with X-linked hypospadias type 2, a condition that alters the placement of the male urethral opening and potentially impacts reproductive fitness. In evolutionary biology, natural selection is often detected by comparing the rates of non-synonymous (dN) and synonymous (dS) substitutions (ω = dN/dS). Positive selection (ω > 1) represents the rapid fixation of beneficial mutations that enhance an organism’s fitness, distinguishing it from purifying selection (ω < 1), which removes deleterious mutations, and neutral evolution (ω = 1), which involves random genetic drift. Building upon broader genomic surveys, this study provides a high-resolution analysis of MAMLD1 using the PAML v4.9 suite across 20 primate species. By employing site models to assess selection across the primate phylogeny, we identified significant signals of positive selection. Findings suggest that MAMLD1 has undergone adaptive evolution, likely driven by sexual selection and its role in reproductive isolation. This research underscores the gene's multifaceted role in shaping human-specific developmental phenotypes and evolutionary strategies.
Patients with difficult intravenous access (DIVA) pose a significant challenge in clinical settings, often leading to delayed care and complications such as pain, phlebitis, and increased infection risk due to multiple insertion attempts. Although evidence supports ultrasound-guided peripheral intravenous catheter (USGPIVC) insertion as a superior approach for DIVA patients, this technique remains largely absent from undergraduate nursing curricula and is typically accessed through post-registration certification, creating workflow inefficiencies and potential delays in care. To address this gap, McGill’s Vascular Access Student Club (VASC) organized a workshop to introduce USGPIVC insertion to nursing students through both theoretical and hands-on learning. Participants completed pre- and post-workshop surveys assessing familiarity with USGPIVC insertions and confidence in managing DIVA patients. Among 24 Bachelor of Nursing (Integrated) (BNI) and Bachelor of Science in Nursing (BScN) participants, 66.7% were in their first year of undergraduate studies. Second- and third-year students reported low baseline confidence in IV insertion for DIVA patients, with 95.4% reporting "not confident at all" or "slightly confident." Although 36.4% had observed USGPIVC insertions, none had received formal training. Post-workshop feedback was overwhelmingly positive: 100% rated the session as beneficial, and 62.5% advocated for training prior to clinical practice. More than 90% of participants expressed interest in advanced training. This student-led initiative reveals a critical gap in undergraduate curriculum and a strong demand for structured ultrasound-guided vascular access training. Integrating these skills early may enhance nursing preparedness for DIVA patients and lead to improved patient care.
Background: Social development in autistic persons, for whom difficulties in social functioning are the basis of a diagnosis, has been evaluated in various ways. For example, behavioral paradigms used to assess biological motion (BM) provide insight into dynamic social information processing, whereas parent-report questionnaires are used to assess broader patterns of social functioning ability in everyday contexts. We assessed score concordance on these two disparate measurements of social development among autistic and non-autistic persons. We further assessed this relationship in relation to mental age (MA). Methods: The participants included 29 autistic (five females, 24 males; mean age = 12.47 years, mean MA = 10.90 years) and 29 non-autistic (eight females, 21 males; mean age = 10.40 years, mean MA = 11.21 years) participants. These groups were subdivided into high and low MA groups based on the median MA (10.57 years). A BM task was used to assess social perceptual processing via accuracy in identifying the walking direction of a point-light figure with increasing distractor dots. Social functioning was evaluated with the Social Responsiveness Scale (SRS-2) and MA was assessed with the Wechsler Abbreviated Scale of Intelligence. Results: The autistic group showed significantly higher SRS-2 scores than the non-autistic group (p < .001), reflecting greater social difficulties. However, the groups did not differ significantly in BM performance (p = .64). BM and SRS-2 scores were significantly correlated when accounting for the diagnostic group (p = .048). Further stratified by mental age group, BM was significantly associated with the SRS-2 in the higher MA group (p = .046) but not in the lower MA group (p > .50). Conclusion: These findings indicate that scores on perceptual and questionnaire-based measures of social functioning are linked at higher MA, indicating a role for cognition in the coherence of disparate aspects of social development.
The hippocampus supports spatial navigation, memory, and planning through the formation of a cognitive map: a structured environmental representation reflected in its neural activity. These neural dynamics can be modeled computationally using recurrent neural networks (RNNs). However, these RNNs are typically trained via reinforcement learning (RL) using external rewards, failing to capture the intrinsic drive of freely exploring organisms in the absence of external rewards. Instead, reward-free RL models, which rely on internal environmental representations, are better candidates to study novelty-seeking and exploratory behaviour. This study aims to investigate whether an RNN exhibiting hippocampal-like activity builds spatial representations sufficient to support exploratory behavior in reward-free RL agents. We leveraged an existing RNN trained for sensory sequence prediction, which exhibits hippocampal-like activity patterns, and used its prediction error as the intrinsic reward to train an Actor-Critic agent. We used a Novel Object Recognition task to quantify its preference for novel stimuli. The RL agent occupied the region of interest (defined as a 3-unit radius around the novel object) significantly more often than a random agent (29.3% ± 3.4% vs. 11.3% ± 1.1% [mean ± SEM], Welch's t-test, p < 0.01), across multiple episodes and novel object locations. The RL agent’s performance was also measured in a multi-room environment. It spent 8.2% ± 0.2% of its time in the most distant and novel room, a significant increase over the 0.023% ± 0.017% of the random control (p < 0.05). This work demonstrates that hippocampal-like representations can support exploratory behavior, and can help us investigate how cognitive maps guide exploration and navigation.
