Membrane computing and brain modelling

We briefly discuss variants of (extended) spiking neural P systems that combine features from the areas of membrane computing and spiking neurons. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Global Interoperability Using Semantics, Standards, Science and Technology (GIST)

“Global Interoperability Using Semantics, Standards, Science and Technology” is a concept that is predicated on the assumption that the semantic integration, frameworks and standards that support information exchange, and advances in science and technology can enable information-systems interoperability for many diverse users. This paper recommends technologies and approaches for enabling interoperability across a wide spectrum of political, geographical, and organizational levels, e.g. coalition, federal, state, tribal, regional, non government, and private. These recommendations represent steps toward the goal of the Semantic Web, where computers understand information on web sites through knowledge representations, agents, and ontologies.     

Tissue engineering of the synovial joint: the role of cell density

The ultimate goal in the tissue engineering of the synovial joint is to fabricate biologically derived analogues that can replace severely degenerated or traumatized synovial joint components. A number of challenges must be addressed before reaching this ultimate goal. In this report, the relevance of cell seeding density in the synthesis of chondrogenic and osteogenic matrices from human mesenchymal stem cells is explored. Human mesenchymal stem cells (hMSCs) were differentiated into chondrogenic cells and osteogenic cells ex vivo and encapsulated in poly(ethylene glycol) diacrylate (PEGDA) hydrogel at densities of 5 x 106 cells/ml, 40 x 10(6) cells/ml, and 80 x 10(6) cells/ml, in addition to a cell-free poly(ethylene glycol) (PEG) control group (0 x 10(6) cells/ml). Cell-seeded or cell-free PEG constructs were separately incubated in vitro for 4 weeks or implanted in vivo in the dorsum of immunodeficient rats for 4 weeks. In-vitro data demonstrated that hMSC-derived chondrocytes or hMSC-derived osteoblasts maintained their lineages per Safranin O and von Kossa staining after incubation for 4 weeks. The general pattern of initial cell seeding densities of 5 x 10(6) cells/ml, 40 x 10(6) cells/ml, and 80 x 10(6) cells/ml were preserved following in-vitro cultivation. Similarly, in-vivo data revealed that hMSC-derived chondrocytes and hMSC-derived osteoblasts maintained their respective lineages and the pattern of cell-seeding densities. An attempt was made to fabricate a composite construct with PEGDA hydrogel and polycaprolactone (PCL) with designed internal porosity for an osteochondral graft. Various cell-seeding densities as delineated in this report can be realized in the composite PEG-PCL graft. The findings demonstrate that cell-seeding density is likely a key parameter to consider in tissue-engineering design. The source of cells can either be transplanted cells or internally recruited cells.     

How do designers represent to themselves the users' needs?

This paper reports on an ergonomic study carried out during the design of a cutting machine-tool for the composite material in carbody parts casting. During this design process, the users’ needs were inferred by the designers on the basis of their own mental representations of the use of the new device. These representations of the users’ needs, correct or false, play a decisive role in the choice of a solution. The aim of the study is to identify their particularity. Analyzing the design meetings, we have highlighted that users are considered either as subsystems or basic design principles or elements of an imagined scenario. We have shown that these representations are linked to the types of meetings held during the design process. Accordingly, a diversification of the types of meetings should be promoted by the project leader, so that designers extend their points of view of the operators.     

Diffusive Behavior of Bedform-Induced Hyporheic Exchange in Rivers

Solute transport in natural streams is a complex phenomenon that involves both in-stream dispersion and mass exchange with the porous zones surrounding the water body. Due to the complex nature of the riverine systems several models may be used to simulate and analyze the transport of solutes with different degrees of complexity. The bedform-induced hyporheic transport is a stream-subsurface exchange mechanism that can be reproduced in controlled systems, such as laboratory flumes. Application of a simple Fickian diffusion model to laboratory data obtained with passive solutes and stationary bedforms proves successful within a range of durations of the contamination process. A dimensionless form of the diffusion coefficient, scaled with dynamic, physical, and geometric properties of the system is derived by comparison with another physically based model. A prediction of the dimensionless diffusion coefficient is obtained as a function of the timescale of the exchange process and is validated with a few sets of results from laboratory tests.     

Long COVID: Association of Functional Autoantibodies against G-Protein-Coupled Receptors with an Impaired Retinal Microcirculation

Long COVID (LC) describes the clinical phenotype of symptoms after infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diagnostic and therapeutic options are limited, as the pathomechanism of LC is elusive. As the number of acute SARS-CoV-2 infections was and is large, LC will be a challenge for the healthcare system. Previous studies revealed an impaired blood flow, the formation of microclots, and autoimmune mechanisms as potential factors in this complex interplay. Since functionally active autoantibodies against G-protein-coupled receptors (GPCR-AAbs) were observed in patients after SARS-CoV-2 infection, this study aimed to correlate the appearance of GPCR-AAbs with capillary microcirculation. The seropositivity of GPCR-AAbs was measured by an established cardiomyocyte bioassay in 42 patients with LC and 6 controls. Retinal microcirculation was measured by OCT–angiography and quantified as macula and peripapillary vessel density (VD) by the Erlangen-Angio Tool. A statistical analysis yielded impaired VD in patients with LC compared to the controls, which was accentuated in female persons. A significant decrease in macula and peripapillary VD for AAbs targeting adrenergic β2-receptor, MAS-receptor angiotensin-II-type-1 receptor, and adrenergic α1-receptor were observed. The present study might suggest that a seropositivity of GPCR-AAbs can be linked to an impaired retinal capillary microcirculation, potentially mirroring the systemic microcirculation with consecutive clinical symptoms.     

Preclinical Assessment of the Combination of PSMA-Targeting Radionuclide Therapy with PARP Inhibitors for Prostate Cancer Treatment

Prostate specific membrane antigen targeted radionuclide therapy (PSMA-TRT) is a promising novel treatment for prostate cancer (PCa) patients. However, PSMA-TRT cannot be used for curative intent yet, thus additional research on how to improve the therapeutic efficacy is warranted. A potential way of achieving this, is combining TRT with poly ADP-ribosylation inhibitors (PARPi), which has shown promising results for TRT of neuroendocrine tumor cells. Currently, several clinical trials have been initiated for this combination for PCa, however so far, no evidence of synergism is available for PCa. Therefore, we evaluated the combination of PSMA-TRT with three classes of PARPi in preclinical PCa models. In vitro viability and survival assays were performed using PSMA-expressing PCa cell lines PC3-PIP and LNCaP to assess the effect of increasing concentrations of PARPi veliparib, olaparib or talazoparib in combination with PSMA-TRT compared to single PARPi treatment. Next, DNA damage analyses were performed by quantifying the number of DNA breaks by immunofluorescent stainings. Lastly, the potential of the combination treatments was studied in vivo in mice bearing PC3-PIP xenografts. Our results show that combining PSMA-TRT with PARPi did not synergistically affect the in vitro clonogenic survival or cell viability. DNA-damage analysis revealed only a significant increase in DNA breaks when combining PSMA-TRT with veliparib and not in the other combination treatments. Moreover, PSMA-TRT with PARPi treatment did not improve tumor control compared to PSMA-TRT monotherapy. Overall, the data presented do not support the assumption that combining PSMA-TRT with PARPi leads to a synergistic antitumor effect in PCa. These results underline that extensive preclinical research using various PCa models is imperative to validate the applicability of the combination strategy for PCa, as it is for other cancer types.     

Recent Experiences with Listeria monocytogenes in New Zealand and development of a food control risk-based strategy

A risk-based strategy for Listeria monocytogenes has been developed by New Zealand Food Safety Authority. Incidents of L. monocytogenes in ready-to-eat foods reported to the regulatory authority were analysed to identify common factors that contributed to the contamination. In addition, the current regulatory framework and available food industry guidance were reviewed to prepare a strategy that will provide a consistent and informed approach to managing the risk of L. monocytogenes. Also recognised is the future impact of an aging population and an increase in the availability and range of chilled ready-to-eat foods that should be integrated into the strategy if an objective of ‘no increase in the reported incidence of foodborne listeriosis after five years’ is to be achieved.