Elucidating the neuropathophysiology of COVID-19 using quantum dot biomimetics of SARS-CoV-2

Quantum dots were encapsulated in polymeric phospholipid micelles conjugated to multiple ligands of SARS-CoV-2 spike protein to form fluorescent biomimetic nanoparticles for SARS-CoV-2 (COVID-QDs). Phosphatidylethanolaminepolyethylene glycol (PE:PEG) was appended with bis(4-methylphenyl)sulfone to form PE:PEG:bis-sulfone and self-assembled into micelles around CdSe/CdS core/shell quantum dots via thin-film rehydration. The introduction of the bis-sulfone group the surface of the micelle-encapsulated quantum dots provides multiple sites for conjugation to his-tagged SARS-CoV-2 spike protein via a bisalkylation mechanism. Based on the eluted unconjugated fraction, we estimate that an average of seven spike proteins are conjugated per COVID-QD. We treated an in-vitro model system for the neurovascular unit (NVU) with these COVID-QD constructs to investigate the COVID-QDs, and by proxy SARS-CoV-2, may modulate the NVU leading to the COVID-19 associated neuropathophysiology. © 2022 SPIE

THE RIGHT TO CONTEST AI

Artificial intelligence (AI) is increasingly used to make important decisions, from university admissions selections to loan determinations to the distribution of COVID-19 vaccines. These uses of AI raise a host of concerns about discrimination, accuracy, fairness, and accountability. In the United States, recent proposals for regulating AI focus largely on ex ante and systemic governance. This Article argues instead-or really, in addition-for an individual right to contest AI decisions, modeled on due process but adapted for the digital age. The European Union, in fact, recognizes such a right, and a growing number of institutions around the world now call for its establishment. This Article argues that despite considerable differences between the United States and other countries, establishing the right to contest AI decisions here would be in keeping with a long tradition of due process theory. This Article then fills a gap in the literature, establishing a theoretical scaffolding for discussing what a right to contest should look like in practice. This Article establishes four contestation archetypes that should serve as the bases of discussions of contestation both for the right to contest AI and in other policy contexts. The contestation archetypes vary along two axes: from contestation rules to standards and from emphasizing procedure to establishing substantive rights. This Article then discusses four processes that illustrate these archetypes in practice, including the first in-depth consideration of the GDPR's right to contestation for a U.S. audience. Finally, this Article integrates findings from these investigations to develop normative and practical guidance for establishing a right to contest AI.

Impact of the COVID-19 pandemic on acute appendicitis in children.

BACKGROUND AND OBJECTIVES: Since the COVID-19 pandemic confinement was established in Spain on March 9, 2020, the number of visits to the pediatric Emergency Department (ED) has decreased dramatically, probably due to the fear of parents becoming infected in the hospital environment. The aim of this work was to analyze the medium-term consequences during the first 9 months after the onset of the COVID-19 pandemic in children with acute appendicitis (AA). MATERIAL AND METHODS: A retrospective study was performed on children operated on for AA in our institution between 2017 and 2020, who were distributed in two groups according to the date of surgery: COVID-19 group (after March 9, 2020) and control group (before March 9, 2020). Demographic variables, associated symptoms, time from symptoms onset, hospital stay, rate of complicated AA and postoperative complications were analyzed. RESULTS: A total of 1274 patients were included (288 COVID group; 986 control group), without demographic differences. Time from symptom onset was significantly longer in COVID-19 group (34.5 vs. 24.2h; p=0.021), although no differences in associated symptoms were observed between both groups. COVID-19 group presented a higher rate of complicated AA (20.1% vs. 14%; OR: 1.55; CI 95% [1.10-2.18]; p=0.008), a longer hospital stay (3.5 vs. 2.8 days; p=0.042) as well as a higher rate of postoperative complications (21.5% vs. 15.7%; OR: 1.47; CI 95% [(1.06-2.04)]; p=0.008). CONCLUSION: In our experience there was a negative medium-term effects of the COVID-19 pandemic on children with acute appendicitis: delayed ED visits, increased rate of complicated AA, increased hospital stay and increased postoperative complications.

Context Specification in the Computational Modelling of Human Immune System Response to Viral Infections

The human immune system is studied at different scales (molecular, cellular, tissue, organism, population) with varied granularity and spatiotemporal dimensions. Innate and adaptive immune responses to viral infections are researched in vitro, in vivo, and in silico using mathematical and computational methods. The construction of computational models is an iterative and interactive process which combines existing knowledge and hypotheses (knowledge-driven approach) with empirical datasets (data-driven approach). The resulting models should ideally provide reusability, composability, and interoperability to support system simulation. The main premises of this paper are (1) computational models can be used not only for representation of existing knowledge, but also as experimental tools to demonstrate, exemplify, create, and serve as test-beds for the analysis of empirical data;and (2) computational models should be evaluated in terms of their usability (defined as a measure of how well a specified group of users can achieve predefined goals effectively, efficiently, and satisfactorily in a specified context of use). The usability measure is specified by the context information: user characteristics, their goals, and additional constraints (e.g., data availability, temporal limitations). This paper focuses on the modelling process performed by multidisciplinary teams and the usability of models for the exploration of immune response to viral infections. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Complex Adaptive Systems Conference, June 2021.