Sound black-box checking in the LearnLib

Innovations in Systems and Software Engineering - In black-box checking (BBC) incremental hypotheses on the behavior of a system are learned in the form of finite automata, using information from a...     

Data-driven placemaking: Public space canopy design through multi-objective optimisation considering shading,structural and social performance

In the context of ongoing densification of cities and aging urban populations, public spaces are a crucial infrastructure to support the physical and mental wellbeing of urban residents. The design of public space furniture elements is often standardised, and not considered in relation to environmental conditions and mechanisms of social interaction. This article presents a digital workflow to generate site-specific designs for shaded public seating, considering the relationships of local public places to their surroundings. A strategy for customised and site-specific design is developed through the use of multiple software tools, employing evolutionary algorithms and multi-objective optimisation. The method is applied to a small public space canopy prototype installed within a public housing estate in Hong Kong, incorporating additional criteria to achieve a low-cost and light-weight structure. Through multiple stages of refinement and optimisation, a material, structural and social performance-driven outcome was achieved that creates a shaded space for public seating, people watching and social interaction. As part of a larger research agenda exploring architectural form-finding and environmental psychology, the project represents potential new applications in the emerging field of socially driven computational design.     

A comparative assessment of local municipal food policy integration in the Netherlands

ABSTRACT

Local governments around the world increasingly engage in food governance, aiming to address food system challenges such as obesity, food waste, or food insecurity. However, the extent to which municipalities have actually integrated food across their policies remains unknown. This study addresses this question by conducting a medium-n systematic content analysis of local food policy outputs of 31 Dutch municipalities. Policy outputs were coded for the food goals and instruments adopted by local governments. Our analysis shows that most municipalities integrate food to a limited extent only, predominantly addressing health and local food production or consumption. Furthermore, municipalities seem hesitant to use coercive instruments and predominantly employ informative and organizational instruments. Nonetheless, a small number of municipalities have developed more holistic approaches to address food challenges. These cities may prove to be a leading group in the development of system-based approaches in Dutch local food policy.     

Simplified Monopalmitoyl Toll-like Receptor 2 Ligand Mini-UPam for Self-Adjuvanting Neoantigen-Based Synthetic Cancer Vaccines

Synthetic vaccines, based on antigenic peptides that comprise MHC−I and MHC-II T-cell epitopes expressed by tumors, show great promise for the immunotherapy of cancer. For optimal immunogenicity, the synthetic peptides (SPs) should be adjuvanted with suitable immunostimulatory additives. Previously, we have shown that improved immunogenicity in vivo is obtained with vaccine modalities in which an SP is covalently connected to an adjuvanting moiety, typically a ligand to Toll-like receptor 2 (TLR2). SPs were covalently attached to UPam, which is a derivative of the classic TLR2 ligand Pam₃CysSK₄. A disadvantage of the triply palmitoylated UPam is its high lipophilicity, which precludes universal adoption of this adjuvant for covalent modification of various antigenic peptides as it renders the synthetic vaccine insoluble in several cases. Here, we report a novel conjugatable TLR2 ligand, mini-UPam, which contains only one palmitoyl chain, rather than three, and therefore has less impact on the solubility and other physicochemical properties of a synthetic peptide. In this study, we used SPs that contain the clinically relevant neoepitopes identified in a melanoma patient who completely recovered after T-cell therapy. Homogeneous mini-UPam-SP conjugates have been prepared in good yields by stepwise solid-phase synthesis that employed a mini-UPam building block pre-prepared in solution and the standard set of Fmoc-amino acids. The immunogenicity of the novel mini-UPam-SP conjugates was demonstrated by using the cancer patient's T-cells.     

Low‐Temperature Chemical Synthesis of High‐Purity Diacylglycerols (DAG) from Monoacylglycerols (MAG)

A chemical method was developed for low‐temperature synthesis of DAG from MAG followed by an easy purification procedure in order to obtain high‐purity DAG. Solvent‐assisted and solvent‐free reaction conditions were used, combined with different catalysts (sodium methoxide, p‐toluenesulfonic acid, methanesulfonic acid, and sulfuric acid). All reactions were performed at 35 and 70 °C. By increasing both acidity and polarity of the catalyst the equilibrium shifts towards the formation of DAG. When using sulfuric acid in solvent‐assisted condition at 70 °C, 88 % conversion was obtained after 20 min of reaction (77 % w/w DAG in the reaction mixture after evaporation of the solvent). After purifying by means of column chromatography, 96 % pure DAG were obtained. The overall yield of DAG was 81 %.     

A Nanochannel Platform for Single DNA Studies: From Crowding,Protein DNA Interaction,to Sequencing of Genomic Information

The study of nanochannel-confined DNA is important from biotechnological and biophysical points of view. We produce nanochannels in elastomer with soft lithography and proton beam writing. Issues concerning DNA confined in such quasi one-dimensional channels are discussed. We describe DNA stretching via the control of channel diameter and buffer conditions and how the extension can be interpreted with theory and computer simulation. We then discuss the conformation of nano-confined DNA crowded by neutral polymers and like-charged proteins. As an example of a protein that has an affinity to DNA, the effect of heat-stable nucleoid-structuring protein, H-NS, on the folding and compaction of DNA is reviewed. Compaction of DNA by eukaryotic protamine and unpacking of pre-compacted DNA through an increase in salt concentration are discussed. We review results obtained with a novel, cross-channel device that allows the monitoring of the dynamic, conformational response of DNA after exposure to a ligand or protein and/or a change in buffer conditions in situ. As a biotechnological application, linearization of DNA by bottlebrush coating with a polypeptide copolymer is discussed. It is demonstrated that large-scale genomic organization can be sequenced using single DNA molecules on an array of elastomeric nanochannels. Overall, our results show that the effects of ligands and proteins on the conformation, folding, and condensation of DNA are not only related to classical controlling factors, such as osmotic pressure, charge, and binding, but that the interplay with confinement in a nanospace is of paramount importance.     

Catalytic One‐Pot Oxetane to Carbamate Conversions: Formal Synthesis of Drug Relevant Molecules

Oxetanes are versatile building blocks in drug‐related synthesis to induce property‐modulating effects. Whereas related oxiranes are widely used in coupling chemistry with carbon dioxide (CO₂) to afford value‐added commodity chemicals, oxetane/CO₂ couplings remain extremely limited despite the recent advances in the synthesis of these four‐membered heterocycles. Here we report an effective one‐pot three‐component reaction (3CR) strategy for the coupling of (substituted) oxetanes, amines and CO₂ to afford a variety of functionalized carbamates with excellent chemoselectivity and good yields. The process is mediated by an aluminium‐based catalyst under relatively mild conditions and the developed catalytic methodology can be applied to the formal synthesis of two pharmaceutically relevant carbamates with the 3CR being a key step.

     

An Improved Technique for the Rapid Chemical Characterisation of Bacterial Terpene Cyclases

A derivative of the pET28c(+) expression vector was constructed. It contains a yeast replication system (2μ origin of replication) and a yeast selectable marker (URA3), and can be used for gene cloning in yeast by efficient homologous recombination, and for heterologous expression in E. coli. The vector was used for the expression and chemical characterisation of three bacterial terpene cyclases.