Denotative and Connotative Semantics in Hypermedia: Proposal for a Semiotic-Aware Architecture

In this article we claim that the linguistic-centered view within hypermedia systems needs refinement through a semiotic-based approach before real interoperation between media can be achieved. We discuss the problems of visual signification for images and video in dynamic systems, in which users can access visual material in a non-linear fashion. We describe how semiotics can help overcome such problems, by allowing descriptions of the material on both denotative and connotative levels. Finally we propose an architecture for a dynamic semiotic-aware hypermedia system

Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars

Lakes existed on Mars later than 3.6 billion years ago, according to sedimentary evidence for deltaic deposition. The observed fluviolacustrine deposits suggest that individual lake-forming climates persisted for at least several thousand years (assuming dilute flow). But the lake watersheds’ little-weathered soils indicate a largely dry climate history, with intermittent runoff events. Here we show that these observational constraints, although inconsistent with many previously proposed triggers for lake-forming climates, are consistent with a methane burst scenario. In this scenario, chaotic transitions in mean obliquity drive latitudinal shifts in temperature and ice loading that destabilize methane clathrate. Using numerical simulations, we find that outgassed methane can build up to atmospheric levels sufficient for lake-forming climates, if methane clathrate initially occupies more than 4% of the total volume in which it is thermodynamically stable. Such occupancy fractions are consistent with methane production by water–rock reactions due to hydrothermal circulation on early Mars. We further estimate that photochemical destruction of atmospheric methane curtails the duration of individual lake-forming climates to less than a million years, consistent with observations. We conclude that methane bursts represent a potential pathway for intermittent excursions to a warm, wet climate state on early Mars

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Non expanded mesenchymal stem cells for regenerative medicine: yield in stromal vascular fraction from adipose tissues.

The adipose-derived stromal vascular fraction (SVF) represents a rich source of mesenchymal cells, potentially able to differentiate into adipocytes, chondrocytes, osteoblasts, myocytes, cardiomyocytes, hepatocytes, and neuronal, epithelial, and endothelial cells. These cells are ideal candidates for use in regenerative medicine, tissue engineering, including gene therapy, and cell replacement cancer therapies. In this work, we aimed to the optimization of the adipose SVF-based therapy, and the effect of the collection site, surgical procedure, and tissue processing techniques on SVF yield was evaluated in terms of cell recovery and live cells, taking into account the effect of gender, age, and body mass index. Adipose tissue samples were recovered from 125 informed subjects (37 males and 88 females; mean age: 51.31 years; range: 15-87 years), and digested in different condition with collagenase. A multivariate linear model put in evidence that in males the best collection site in terms of yield is located in the abdomen, whereas in females the biopsy region do not influence cell recovery; the collection technique, the age, and the body mass index of donor seem not to influence the cell yield. The tissue-processing procedures strongly modify the yield and the vitality of cells: a collagenase concentration of 0.2% and a digestion time of 1 h could be chosen as the best operating conditions

Human engineered cartilage and decellularized matrix as an alternative to animal osteoarthritis model

(1) Objective: to obtain a reproducible, robust, well-defined, and cost-affordable in vitro model of human cartilage degeneration, suitable for drug screening; (2) Methods: we proposed 3D models of engineered cartilage, considering two human chondrocyte sources (articular/nasal) and five culture methods (pellet, alginate beads, silk/alginate microcarriers, and decellularized cartilage). Engineered cartilages were treated with pro-inflammatory cytokine IL-1β to promote cartilage degradation; (3) Results: articular chondrocytes have been rejected since they exhibit low cellular doubling with respect to nasal cells, with longer culture time for cell expansion; furthermore, pellet and alginate bead cultures lead to insufficient cartilage matrix production. Decellularized cartilage resulted as good support for degeneration model, but long culture time and high cell amount are required to obtain the adequate scaffold colonization. Here, we proposed, for the first time, the combined use of decellularized cartilage, as aggrecanase substrate, with pellet, alginate beads, or silk/alginate microcarriers, as polymeric scaffolds for chondrocyte cultures. This approach enables the development of suitable models of cartilaginous pathology. The results obtained after cryopreservation also demonstrated that beads and microcarriers are able to preserve chondrocyte functionality and metabolic activity; (4) Conclusions: alginate and silk/alginate-based scaffolds can be easily produced and cryopreserved to obtain a cost-affordable and ready-to-use polymer-based product for the subsequent screening of anti-inflammatory drugs for cartilage diseases