Ankylosing Spondylitis: a trade Off of HLA-B27, ERAP, and pathogen interconnections? Focus on Sardinia

The frequency of HLA-B27 in patients with Ankylosing Spondylitis (AS) is over 85%. There are more than 170 recognized HLA-B27 alleles but the majority of them is not sufficiently represented for genetic association studies. So far only two alleles, the HLA-B*2706 in Asia and the HLA-B*2709 in Sardinia, have not been found to be associated with AS. The highly homogenous genetic structure of the Sardinian population has favored the search of relevant variants for disease-association studies. Moreover, malaria, once endemic in the island, has been shown to have contributed to shape the native population genome affecting the relative allele frequency of relevant genes. In Sardinia, the prevalence of HLA-B*2709, which differs from the strongly AS-associated B*2705 prototype for one amino acid (His/Asp116) in the F pocket of the peptide binding groove, is around 20% of all HLA-B27 alleles. We have previously hypothesized that malaria could have contributed to the establishment of this allele in Sardinia. Based on our recent findings, in this perspective article we speculate that the Endoplasmic Reticulum Amino Peptidases, ERAP1 and 2, associated with AS and involved in antigen presentation, underwent co-selection by malaria. These genes, besides shaping the immunopeptidome of HLA-class I molecules, have other biological functions that could also be involved in the immunosurveillance against malaria

Using synchronism of chaos for adaptive learning of network topology

In this paper we consider networks of dynamical systems that evolve in synchrony and investigate how dynamical information from the synchronization dynamics can be effectively used to learn the network topology, i.e., identify the time evolution of the couplings between the network nodes. To this aim, we present an adaptive strategy that, based on a potential that the network systems seek to minimize in order to maintain synchronization, can be successfully applied to identify the time evolution of the network from limited information. This strategy takes advantage of the properties of synchronism of chaos and of the presence of different communication delays over the network links. As a motivating example we consider a network of sensors surveying an area, in which information regarding the time evolution of the network connections can be used, e.g., to detect changes taking place within the area. We propose two different setups for our strategy. In the first one, synchronization has to be achieved at each node (as well as the identification of the couplings over the network links), based solely on a single scalar signal representing a superposition of signals from the other nodes in the network. In the second one, we incorporate an additional node, termed the maestro, having the function of maintaining network synchronization. We will see that when such an arrangement is realized, it will become possible to effectively identify the time evolution of networks that are much larger than would be possible in the absence of a maestro.Comment: 22 pages, 12 figures, accepted for publication on Physical Review

Semantic and inferencing abilities in children with communication disorders

Background: Semantic and inferencing abilities have not been fully examined in children with communication difficulties. Aims: To investigate the inferential and semantic abilities of children with communication difficulties using newly designed tasks. Methods & Procedures: Children with different types of communication disorder were compared with each other and with three groups of typically developing children: those of the same chronological age and two groups of younger children. In total, 25 children aged 11 years with specific language impairment and 22 children, also 11 years of age, with primary pragmatic difficulties were recruited. Typically developing groups aged 11 (n = 35; age‐match), and those aged 9 (n = 40) and 7 (n = 37; language similar) also participated as comparisons. Outcomes & Results: For Semantic Choices, children with specific language impairment performed significantly more poorly than 9‐ and 11‐year‐olds, whilst the pragmatic difficulties group scored significantly lower than all the typically developing groups. Borderline differences between specific language impairment and pragmatic difficulties groups were found. For inferencing, children with communication impairments performed significantly below the 11‐year‐old peers, but not poorer than 9‐ and 7‐year‐olds, suggesting that this skill is in line with language ability. Six children in the pragmatic difficulties group who met diagnosis for autism performed more poorly than the other two clinical groups on both tasks, but not statistically significantly so. Conclusions: Both tasks were more difficult for those with communication impairments compared with peers. Semantic but not inferencing abilities showed a non‐significant trend for differences between the two clinical groups and children with pragmatic difficulties performed more poorly than all typically developing groups. The tasks may relate to each other in varying ways according to type of communication difficulty

THE EFFECTS OF THE SPOTTED LANTERNFLY ON ANT AND LAND SLUG POPULATIONS IN EASTERN PENNSYLVANIA

Invasive species pose a significant threat to ecosystems. The spotted lanternfly (Lycorma delicatula), an invasive species in the northeastern USA, consumes plant phloem and produces sugary honeydew, which in turn is often covered by sooty mold. Honeydew is a high value resource for ants that fuels worker activity and competitive interactions, and as such the presence of L. delicatula has the potential to impact the diversity and composition of ant communities. Furthermore, the presence of sooty mold and the honeydew itself provides additional resources for land slugs, important seed predators and a prey item for many predators. To test for an effect of L. delicatula invasion on ant and land slug populations, I collected invertebrate samples using pitfall traps at four locations in Pennsylvania, two within and two outside of the current range of L. delicatula, during the summers of 2020 and 2021. Principal component analysis identified distinctive community compositions associated with the presence of L. delicatula, most strongly differentiated by the high incidence of Aphaenogaster picea and low incidence of Camponotus chromaiodes at locations outside the current range of L. delicatula. Aphaenogaster species in the rudis species complex, including A. picea, are important seed dispersers and are known to be yielding in interspecific interactions, while C. chromaiodes is known to be more aggressive. These data suggest that the presence of L. delicatula may favor ant species which exhibit high interspecific aggression and can dominate the additional food sources it provides. Additionally, land slug abundance was significantly higher at locations infested by L. delicatula. Thus, two additional avenues were identified by which L. delicatula can exert a cascading effect on the Pennsylvania forest ecosystem

Statistical Approaches to the Inverse Problem

Communications engineering / telecommunication

Accountability disclosure of SOEs: comparing hybrid and private European news agencies

Purpose: This paper aims to explore the financial and non-financial accountability disclosure patterns of state-owned enterprises (SOEs), as hybrid organizations. Design/methodology/approach: Adopting the hybridity concept and resorting to stakeholder theory, this paper works on a comparison between the accountability disclosure patterns of hybrid and private organizations operating in the same industry. European national news agencies are selected as units of analysis and an extensive web content analysis is performed on three categories of information. Findings: SOEs are found to disclose a broader spectrum of information than private organizations, and differences between them have been found. Nevertheless, both financial and non-financial disclosures are underdeveloped in the two organizational types. Research limitations/implications: This paper illustrates how hybridity explains SOEs’ accountability disclosure patterns. Results could not be complemented through information on disclosure through alternative channels. Future studies are encouraged to perform simultaneous comparisons among hybrid, public and private organizations, as well as considering industry specifics. Practical implications: As web accountability disclosure helps to address the demands of distant stakeholders, efforts are needed to enhance SOEs’ web accountability disclosures and not to undermine democratic accountability relationships. Originality/value: This paper contributes to the ongoing debate on the accountability mechanisms and style of SOEs. Using a framework for hybrid organizations provides an understanding of how SOEs, as hybrid organizations, disclose information for accountability. In turn, this allows, and then promotes, the investigation of social phenomena by conceiving hybridity as a standalone institutional space