Gustavus Adolphus College Collections
Not a member yet
92910 research outputs found
Sort by
Revisiting bacterial spore germination in the presence of peptidoglycan fragments
No full textBacterial spores of Bacillus species are metabolically inert cell types formed in response to nutrient starvation. Spores must undergo the process of germination to resume vegetative growth. This process is stimulated by the interaction of various nutrient molecules with specialized clusters of membrane-localized germinant receptors (GRs) present within spores. A second route to spore germination involving the stimulation of the PrkC Ser/Thr kinase by soluble peptidoglycan fragments was proposed in 2008 and has been subject to much less scrutiny. The current study examined the germinative response of spores of Bacillus subtilis, Bacillus cereus, and Bacillus megaterium when incubated in the presence of complex mixtures of peptidoglycan fragments or purified peptidoglycan fragments previously identified as germinants. The spore suspensions did not show any appreciable germination, as determined by fluorometric dipicolinic acid release, flow cytometry, or microscopy. However, the purified peptidoglycan fragments displayed a stimulatory effect on germination triggered by amino acids and nucleosides with spore GRs. In contrast, GR-mediated germination was inhibited to varying degrees by unidentified components of the complex peptidoglycan fragment mixtures derived from enzymatic digests of B. subtilis vegetative sacculi. Collectively, our results indicate that soluble peptidoglycan fragments cannot initiate spore germination but may influence germination via mechanisms that have yet to be established
Multi-parameter multi-sensor data fusion for drinking water distribution system water quality management
No full textWater quality events within drinking water distribution systems are commonly first detected by consumers. This undermines confidence, is in contrast to the level of service consumers now expect and in extreme cases can indicate a risk to public health. The objective of this paper is to propose and show how the value and insight gained increases in progression from single parameter, single location to multiple parameter multiple location sensor approaches. This is done using real-world datasets from operational systems and application of multiple analytical approaches in combination to extract actionable insights. Analytical methods include: cross-correlation for system connectivity and transit time derivation; an innovative turbidity event scale system; and material flux analysis of discolouration material. This research demonstrates the ability to confirm and track network-wide events, determine root causes, and inform proactive management via advisory event scores. The evidence provided of the multiplicative jumps in value in progressing towards multiple parameter multiple sensor approaches is vital to help guide future strategies for networks of water quality sensing
Spatio-temporal graph neural network based child action recognition using data-efficient methods: A systematic analysis
No full textThis paper presents implementations on child activity recognition (CAR) using spatial–temporal graph neural network (ST-GNN)-based deep learning models with the skeleton modality. Prior implementations in this domain have predominantly utilized CNN, LSTM, and other methods, despite the superior performance potential of graph neural networks. To the best of our knowledge, this study is the first to use an ST-GNN model for child activity recognition employing both in-the-lab, in-the-wild, and in-the-deployment skeleton data. To overcome the challenges posed by small publicly available child action datasets, transfer learning methods such as feature extraction and fine-tuning were applied to enhance model performance.
As a principal contribution, we developed an ST-GNN-based skeleton modality model that, despite using a relatively small child action dataset, achieved superior performance (94.81%) compared to implementations trained on a significantly larger (x10) adult action dataset (90.6%) for a similar subset of actions. With ST-GCN-based feature extraction and fine-tuning methods, accuracy improved by 10%–40% compared to vanilla implementations, achieving a maximum accuracy of 94.81%. Additionally, implementations with other ST-GNN models demonstrated further accuracy improvements of 15%–45% over the ST-GCN baseline.
The results on activity datasets empirically demonstrate that class diversity, dataset size, and careful selection of pre-training datasets significantly enhance accuracy. In-the-wild and in-the-deployment implementations confirm the real-world applicability of above approaches, with the ST-GNN model achieving 11 FPS on streaming data. Finally, preliminary evidence on the impact of graph expressivity and graph rewiring on accuracy of small dataset-based models is provided, outlining potential directions for future research. The codes are available at https://github.com/sankamohotttala/ST_GNN_HAR_DEM
Drebrin Upregulation Regulates Astrocyte Polarization and Supports Tissue Recovery After Spinal Cord Injury in Mice
No full textSpinal cord injury (SCI) results in significant disruption of nerve fibers responsible for transmitting signals between the brain and body, often leading to partial or complete motor, sensory, and autonomic dysfunction below the injury site. Astrocytes are an important component in scar formation, crucial for suppression of injury propagation, effective wound healing, and the regulation of neuronal plasticity. Here, we identify the role of the actin-binding protein Drebrin (DBN) in reactive astrogliosis following SCI. SCI induces the upregulation of DBN in astrocytes, which controls immediate injury containment but also the long-term preservation of tissue integrity and healing in the spinal cord. DBN knockout results in enlarged spinal cord lesions, increased immune cell infiltration, and neurodegeneration. Mechanistically, DBN loss disrupts the polarization of scar border-forming astrocytes, leading to impaired encapsulation of the injury. In summary, DBN serves as a pivotal regulator of SCI outcome by modulating astrocytic polarity, which is essential for establishing a protective barrier confining the lesion site
PS07 (P113) Perceptions of patients and physicians from the UK of the burden of chronic spontaneous urticaria: results from the Urticaria Voices study
No full textP072 Improvement across work productivity and quality of life with remibrutinib treatment in patients with chronic spontaneous urticaria in the REMIX-1/2 trials
No full textMetal‐organic nanosheet gels: Hierarchically porous materials for selective loading and differential release
No full textMetal-organic nanosheets (MONs) are intrinsically porous 2D materials with a high surface area and tunable chemistry, which have been widely used in suspensions or on surfaces for a variety of applications. Here, this work demonstrates that MONs can be used to form gels through a simple centrifugation process, and their hierarchically porous structures used to enable the selective loading and differential release of small molecules based on their size and charge. Centrifugation of a suspension of monolayer Zr-BTB MONs (BTB = 1,3,5-benzenetribenzoate) formed gels in a range of solvents with a concentration of ≈1.5 wt.%. The gels displayed rapid self-healing behavior, can be extruded through a syringe needle into different shapes, and freeze-dried to form self-supporting aerogels. Rapid and selective loading of the gels with a range of small molecules can be achieved by centrifugation of suspensions of nanosheets containing different cargo solutions. Small neutral molecules are found to diffuse out of the gel significantly faster than larger molecules, which is attributed to the nanosheets acting as “fishing nets” that allow small molecules to pass through the pores, whilst larger molecules have to take a tortuous path through the hierarchically porous structure. Charged molecules are released slower than the neutral ones, which is attributed to electrostatic interactions with the nanosheets. It is anticipated that hierarchically porous MON-based gels will open up a variety of interesting new applications, including sensing, separation, controlled release, drug loading, and drug delivery
Bidirectional associations between video game playing and ADHD symptoms among school-aged children
No full textPast research has suggested associations between gaming and symptoms of attention-deficit/hyperactivity disorder (ADHD) among children and adolescents. Yet, little research has been conducted to clarify the directionality of this association during middle childhood when ADHD issues typically emerge. Clarifying directionality is key to understanding whether gaming precedes and predicts ADHD symptoms, or the opposite. To shed light on this topic, this study investigates this association longitudinally during middle childhood. We employed a Random Intercept Cross-Lagged Panel Model to estimate longitudinal bidirectional associations between child gaming and ADHD symptoms from ages 6 to 10. Variables were derived from parent-reported child weekly hours of gaming and teacher-reported child ADHD symptoms. Data are from the Quebec Longitudinal Study of Child Development, a population-based cohort of Canadian children (N = 1749). We hypothesized a bidirectional association. Our results revealed that higher levels of ADHD symptoms at age 6 predicted more time gaming at age 7. Likewise, more ADHD symptoms at age 7 predicted more gaming at age 8. However, later in development, this association reverses direction: higher levels of gaming at age 8 predicted more ADHD symptoms at age 10. Additional analyses of separated dimensions of ADHD revealed that associations with gaming were stronger for the hyperactivity/impulsivity dimension. These findings suggest that children with more ADHD symptoms tend to devote more time to gaming during the early years of middle childhood. In turn, this increase in gaming during early school years contributes to worsening ADHD symptoms later in development, particularly hyperactivity/impulsivity symptoms
Speech acts and unspeakable raps
No full textPolice censor drill rap music based on the claim that drill artists incite violence. In this article, I provide a framework for evaluating whether an instance of drill constitutes a speech act of incitement. I also introduce an alternative speech act that drillers may also be performing, drawn from sociological work on drill artists. I show that those who claim drill incites violence (such as the Metropolitan Police) must meet the explanatory and justificatory burden of showing that the speech act of incitement (rather than something else) has been performed, and that it may often be very challenging to meet that burden. Finally, I argue that where that burden is not met, police interventions in drill would constitute a form of illocutionary silencing and discursive injustice. Drill artists are owed careful consideration of the illocutionary acts they perform in their music – more careful than police assumptions about incitement have been
Nutritional content and promotional practices of foods for infants and young children on the spanish market: a cross-sectional product evaluation
No full textThe first 1000 days of life are crucial for health, making it essential that foods for infants and young children (FIYC) meet high nutritional standards, as defined by the World Health Organization's (WHO) Nutrient and Promotion Profile Model (NPPM). There is high reliance on commercially available highly processed FIYC for children under 3 years of age, and a growing market. The aim of this study is to analyse the nutrient profiles of FIYC using the WHO NPPM and determine the proportion of products available in Spain suitable for promotion. Data on 830 FIYC available from brands sold by major retailers in Spain were collected. Product nutrient composition and label information were assessed using the WHO NPPM for the European Region. The processed fruit and vegetables were the most common FIYC category, accounting for 46% of the products surveyed. Overall, only 23% met all NPPM nutritional standards. About 60% of products had excessive sugar content, with 98% of fruit and vegetable purees qualifying for a front-of-pack sugar warning. One in four savoury meals was protein-deficient and one in four of all FIYC was energy-deficient. Only 7% and 2% exceeded the sodium and fat limits, respectively. No product fully met the NPPM promotion recommendations.
Conclusion: Nearly 80% of FIYC products in Spain do not meet WHO’s NPPM criteria for nutrient quality, with many high in sugar, low in protein and too watery (low energy). None met the promotional recommendations, highlighting the need for better regulation to improve the nutritional content and appropriate marketing of products for young children