A network simplification approach to ease topological studies about the food-web architecture

Food webs studies are intrinsically complex and time-consuming. Network data about trophic interaction across different large locations and ecosystems are scarce in comparison with general ecological data, especially if we consider terrestrial habitats. Here we present a complex network strategy to ease the gathering of the information by simplifying the collection of data with a taxonomic key. We test how well the topology of three different food webs retain their structure at the resolution of the nodes across distinct levels of simplification, and we estimate how community detection could be impacted by this strategy. The first level of simplification retains most of the general topological indices; betweenness and trophic levels seem to be consistent and robust even at the higher levels of simplification. This result suggests that generalisation and standardisation, as a good practice in food webs science, could benefit the community, both increasing the amount of open data available and the comparison among them, thus providing support especially for scientists that are new in this field and for exploratory analysis

Weber’s Law-based perception and the stability of animal groups

Group living animals form aggregations and flocks that remain cohesive in spite of internal movements of individuals. This is possible because individual group members repeatedly adjust their position and motion in response to the position and motion of other group members. Here we develop a theoretical approach to address the question, what general features -- if any -- underlie the interaction rules that mediate group stability in animals of all species? We do so by considering how the spatial organisation of a group would change in the complete absence of interactions. Without interactions, a group would disperse in a way that can be easily characterised in terms of Fick's diffusion equations. We can hence address the inverse theoretical problem of finding the individual-level interaction responses that are required to counterbalance diffusion and to preserve group stability. We show that an individual-level response to neighbour densities in the form of Weber's law (a 'universal' law describing the functioning of the sensory systems of animals of all species) results in an 'anti-diffusion' term at the group level. On short time scales, this anti-diffusion restores the initial group configuration in a way which is reminiscent of methods for image deblurring in image processing. We also show that any non-homogeneous, spatial density distribution can be preserved over time if individual movement patterns have the form of a Weber's law response. Weber's law describes the fundamental functioning of perceptual systems. Our study indicates that it is also a necessary -- but not sufficient -- feature of collective interactions in stable animal groups

Induced sputum in the management of COPD: clinical implications

Sputum induction can be used as a non-invasive technique to investigate airway inflammation in asthma and COPD. We reported the case of a 68 year old man with COPD, stage III GOLD, that underwent sputum induction during two exacerbation episodes. The first cell count showed a typical sputum neutrophilia, whereas the second showed sputum eosinophilia. On the basis of sputum cellularity, we decided to treat the first episode with a course of antibiotics and the second exacerbation with a course of antibiotics and oral steroids. The patient showed improvement in both cases, obtaining clinical stabilisation. The induced sputum cell count could be a useful technique in a clinical setting to evaluate the cellular characteristics of airway inflammation during COPD exacerbation and modulate the antinflammatory therapy

Black empowerment and white mobilization: the effects of the Voting Rights Act

The 1965 Voting Rights Act (VRA) paved the road to Black empowerment. How did southern whites respond? Leveraging newly digitized data on county-level voter registration rates by race between 1956 and 1980, and exploiting pre-determined variation in exposure to the federal intervention, we document that the VRA increases both Black and white political participation. Consistent with the VRA triggering countermobilization, the surge in white registrations is concentrated where Black political empowerment is more tangible and salient due to the election of African Americans in county commissions. Additional analysis suggests that the VRA has long-lasting negative effects on whites’ racial attitudes

Assessment of Flame Transfer Function Formulations for the Thermoacoustic Analysis of Lean Burn Aero-Engine Combustors

Abstract The numerical analysis of thermoacoustic instability in lean burn aero-engines requires proper Flame Transfer Functions (FTF) able to describe the complex physical phenomena characterizing the coupling between heat release rate fluctuations and the acoustic field which is further complicated by the use of liquid fuel together with advanced injection systems. In this work simple FTF formulations have been applied to the thermoacoustic analysis of a tubular combustor equipped with a PERM (Partially Evaporating and Rapid Mixing) injection system with the main aim of assessing their capabilities in the prediction of thermoacoustic instabilities in lean burn aero-engine combustors

Hydroxytyrosol Prevents Increase of Osteoarthritis Markers in Human Chondrocytes Treated with Hydrogen Peroxide or Growth-Related Oncogene \u3b1

Hydroxytyrosol (HT), a phenolic compound mainly derived from olives, has been proposed as a nutraceutical useful in prevention or treatment of degenerative diseases. In the present study we have evaluated the ability of HT to counteract the appearance of osteoarthritis (OA) features in human chondrocytes. Pre-treatment of monolayer cultures of chondrocytes with HT was effective in preventing accumulation of reactive oxidant species (ROS), DNA damage and cell death induced by H2O2 exposure, as well as the increase in the mRNA level of pro-inflammatory, matrix-degrading and hypertrophy marker genes, such as iNOS, COX-2, MMP-13, RUNX-2 and VEGF. HT alone slightly enhanced ROS production, but did not enhance cell damage and death or the expression of OA-related genes. Moreover HT was tested in an in vitro model of OA, i.e. three-dimensional micromass cultures of chondrocytes stimulated with growth-related oncogene \u3b1 (GRO\u3b1), a chemokine involved in OA pathogenesis and known to promote hypertrophy and terminal differentiation of chondrocytes. In micromass constructs, HT pre-treatment inhibited the increases in caspase activity and the level of the messengers for iNOS, COX-2, MMP-13, RUNX-2 and VEGF elicited by GRO\u3b1. In addition, HT significantly increased the level of SIRT-1 mRNA in the presence of GRO\u3b1. In conclusion, the present study shows that HT reduces oxidative stress and damage, exerts pro-survival and anti-apoptotic actions and favourably influences the expression of critical OA-related genes in human chondrocytes treated with stressors promoting OA-like features

Addressing Social Misattributions of Large Language Models: An HCXAI-based Approach

Human-centered explainable AI (HCXAI) advocates for the integration of social aspects into AI explanations. Central to the HCXAI discourse is the Social Transparency (ST) framework, which aims to make the socio-organizational context of AI systems accessible to their users. In this work, we suggest extending the ST framework to address the risks of social misattributions in Large Language Models (LLMs), particularly in sensitive areas like mental health. In fact LLMs, which are remarkably capable of simulating roles and personas, may lead to mismatches between designers' intentions and users' perceptions of social attributes, risking to promote emotional manipulation and dangerous behaviors, cases of epistemic injustice, and unwarranted trust. To address these issues, we propose enhancing the ST framework with a fifth 'W-question' to clarify the specific social attributions assigned to LLMs by its designers and users. This addition aims to bridge the gap between LLM capabilities and user perceptions, promoting the ethically responsible development and use of LLM-based technology