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Do Transnational Municipal Networks Accelerate the Net-Zero Transition?:A Mixed-Methods Analysis of the C40 Cities Initiative and the Challenge of Urban Climate Change Mitigation
Get PDFTransnational municipal networks (TMNs) such as C40 or ICLEI have been posited to foster city-to-city learning in accelerating climate change mitigation and, thereby, facilitating the transition to net-zero greenhouse gas emissions. However, the existing literature on the role of climate networks has hardly examined the relationship between membership and climate change mitigation outcomes and impact, without which it is premature to be optimistic about TMNs role in the net-zero transition. In this article, we address this gap through a mixed methods analysis in the case of the C40 cities initiative. We combine a staggered difference-in-differences regression to shed light on the relationship between membership in the C40 initiative and carbon dioxide (CO2) emissions during 2002–18 in over 700 OECD cities with a qualitative cross-case analysis of Bogotá, Colombia and Copenhagen, Denmark to unpack how and when the C40 initiative influences climate action at the city level. Results show that there is no statistically significant relationship between C40 membership and CO2 emissions, indicating that cities in the C40 initiative may not have reduced CO2 emissions more than other OECD cities, after controlling for socioeconomic characteristics, weather, country characteristics, city fixed effects, time fixed effects, and city-specific annual time trends. Furthermore, the complementary qualitative analysis showed the C40 network's direct intervention is limited to increasing or maintaining the ambition of cities; the network was found to have limited influence on city-level policy planning and implementation. There is a need to further study and address local policy implementation for realizing net-zero in relation to TMN membership.</p
Formalising the urban pattern language:A morphological paradigm towards understanding the multi-scalar spatial structure of cities
Get PDFThe urban form is a foundational element in urban analytics, planning, and design. However, systematic and consistent depiction of urban form is challenging due to the complexity of urban elements and the variety of scales involved. This paper formalizes the concept of ‘urban pattern language’ as a multi-scalar analytical approach to decode such complexity, drawing on Christopher Alexander's idea that offers solutions for recurrent design problems observed in historic and contemporary urban settings. This analytic approach is applied to two case study cities to explore how urban forms can be decoded and communicated across scales and demonstrate how urban morphological elements can be systematically organised into recognisable patterns that simplify analysis and enhance understanding. The findings show that these patterns are not arbitrary but follow structured, rule-based relationships that vary across scales, revealing an underlying order within the urban form. Finally, the study illustrates that these rules are unique to each city, potentially reflecting specific cultural, historical, and spatial contexts. By identifying city-specific, multi-scalar patterns, this framework offers a powerful framework for urban planning and design, allowing practitioners to develop adaptable and context-sensitive strategies.</p
Effect of gradient direction on the compressive and energy absorption characteristics of Ti-6Al-4V metamaterials
Get PDFTriply periodic minimal surface (TPMS) graded lattices have attracted significant interest for biomedical applications owing to their structural efficiency and bone-mimicking mechanical properties. This study introduces a novel design methodology for spatially grading Ti-6Al-4V TPMS lattices, with grading orientations classified as one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D), and fabricated by laser powder-bed fusion (PBF-LB). The primary aim was to evaluate the influence of gradient direction on mechanical response and energy absorption through quasi-static compression testing. The experimental results highlight that the grading orientation plays a crucial role in tailoring lattice performance. At 30 % RD, the 3-D graded gyroid exhibited superior properties with an elastic modulus of 3.36 ± 0.14 GPa and yield strength of 107.93 ± 2.8 MPa, outperforming the 1-D graded gyroid (2.48 ± 0.11 GPa modulus; 78.94 ± 2.2 MPa yield strength). Enhanced energy absorption was also observed for the 3-D grading technique, confirming the advantage of multi-directional density variations. An exception was noted for the 3-D graded diamond at 20 % RD. Overall, graded TPMS lattices enable structural flexibility and mechanical performance comparable to natural bone. The findings provide important insights for designing orthopaedic implants. The developed grading technique has great potential in bone replacement biomaterials.</p
Introducing automated testing to video game development via Behaviour-Driven Development
Get PDFGame Software Engineering has emerged as a specialized field distinct from traditional software engineering, addressing unique challenges inherent to the creative process of game development, but lagging behind in using new methods of software engineering. This paper introduces the method of Behavior-Driven Development (BDD) to game software engineering. BDD is popular in software engineering for modelling and testing software. In this paper, we first propose a development process for applying BDD in game development. Then, we provide an integration of BDD tooling in Unity 3D, a major platform for game development. Next, we present a framework for identifying and categorizing game behaviours, to cater for modelling game behaviours in BDD scenarios. Finally, we show applicability of these three contributions on a real-world case study.</p
Joint-on-chip models:Opportunities and challenges in osteoarthritis research
Get PDFOrgan-on-a-chip (OoC) technology has become a game-changer by providing advanced in vitro models of human tissues and organs, allowing thereby conducting a variety of experimentation and assays, ranging from drug testing, toxicity screening, tissue engineering, to disease modeling to, e.g., elucidate mechanisms at play in disease onset and progression. Organ-on-a-chip devices are hybrid models combining cells and microfabricated structures in a microfluidic format, aiming altogether to mimic functional and/or structural features of an organ. OoCs exhibit a number of advantages compared to conventional in vitro and in vivo models: an in vivo–like and tunable microenvironment, dynamic culture, possibility to incorporate a variety of (bio)chemical and (bio)physical cues, with spatial and temporal control thereon, suitability to prepare patient-specific (disease) model, amenability to parallelized and automated studies, and compatibility with routine imaging and molecular assay. As such, OoC is currently acknowledged as a promising technology to reduce and replace experimentation on animals, which are poor mimics of human diseases and physiology.In my presentation, I will briefly introduce OoC models, discuss their applications for OA research with the development of an integrated joint-on-chip platform, present an overview of models of individual tissues and multi-tissues reported in the literature so far, including research from our group, and finally discuss overall opportunities and remaining challenges towards the establishment of a comprehensive multi-OoC joint-on-chip model
Controlling interfacial protein adsorption, desorption and aggregation in biomolecular condensates
No full textAggregation of amyloidogenic proteins is linked to age-related diseases. The presence of interfaces can affect their aggregation mechanism, often speeding up aggregation. α-Synuclein (αSyn) can adsorb to biomolecular condensates, leading to heterogenous nucleation and faster aggregation. Understanding the mechanism underlying localization of amyloidogenic proteins at condensate interfaces is crucial for developing strategies to prevent or reverse their binding. We show that αSyn localization to the surface of peptide-based heterotypic condensates is an adsorption process governed by the protein’s condensate-amphiphilic nature, and the condensate surface charge. Adsorption occurs reversibly in multiple layers and plateaus at micromolar concentrations. Based on these findings, we rationally design three strategies to modulate αSyn accumulation: (i) addition of biomolecules that decrease the condensate ζ-potential, such as NTPs and RNA, (ii) competitive adsorption of proteins targeting the condensate interface, such as G3BP1, DDX4-YFP, EGFP-NPM1, Hsp70, Hsc70, and (iii) preferential adsorption of αSyn to membranes. Removing αSyn from the condensate interface slows aggregation, highlighting potential cellular control over protein adsorption and implications for therapeutic strategies.</p
The Quantification of Terminal Hair by Digital Microscopy:Advancements Towards a More Objective Diagnosis of Hirsutism
No full textPurpose: The modified Ferriman-Gallwey score, currently used to clinically evaluate and quantify excessive hair growth in women with hirsutism, has limitations because of its subjective nature. Therefore, we aim to investigate whether we could quantify terminal hairs on the output of a digital microscope camera to improve the clinical evaluation of hirsutism. Patients and Methods: This feasibility cross-sectional study included 20 healthy men and 15 healthy women. Two independent researchers used a digital microscope camera to obtain photos of the upper lip and chin in all participants. The hair thickness (when ≥ 60 µm), number of terminal hairs and hair color were determined to indicate mean differences between men and women by an independent t-test. Additionally, intraclass correlation coefficients were determined to assess the inter-observer variability. Results: The mean (standard deviation) number of terminal hairs on the upper lip was 27 (15) in men and 0 (1) in women. On the chin, men had a mean (standard deviation) of 29 (18) terminal hairs, compared to 0 (0) in women. This corresponds to mean differences of 27 hairs (range: 19–34) on the upper lip and 28 hairs (range: 19–39) on the chin between men and women. Minimal inter-observer variability was observed, particularly in visible light analyses (intraclass correlation coefficient: 0.998). Conclusion: Digital microscopy with visible light may contribute to a more objective method for diagnosing hirsutism by the quantification of terminal hair. Future studies should focus on the applicability of this new method in women with hirsutism.</p
Conformational Dynamics of Bacteriochlorophyll c in Chlorosomes from the bchQ Mutant of Chlorobaculum tepidum
No full textIn contrast to the common viewpoint that bacteriochlorophyll (BChl) motion is largely absent within the chlorosome assembly, physics-based modeling points to a crucial role of the nanoscale librational motion of the macrocycle for the transfer of excitons. To elucidate this motion experimentally, compositional uniformity and high sensitivity are required. We focused on uniformly 13C labeled chlorosome preparations from the bchQ mutant Chlorobaculum tepidum with significantly enhanced structural homogeneity. The librational motion is characterized using Rotational Echo DOuble Resonance (REDOR), and in addition, the impact of temperature on specific functionalities within BChl molecules is studied with 1-dimensional and 2-dimensional dipolar and scalar-based MAS NMR measurements. Results show the gradual freezing of the tails and side chains of the BChls with decreasing temperature. However, the librational motion analyzed by measuring the 5C–H dipolar coupling strength obtained from REDOR data sets persists at different temperatures. REDOR simulations show a close match to the experimental dephasing frequency of oscillation for a dipolar coupling strength of 17.5 ± 0.5 kHz which is considerably less than the dipolar coupling strength of 22.7 kHz in the rigid limit. Following a two-site jump model, we arrive at an estimate for BChl libration sampling at an angle of θ = 48 ± 4°, corroborating that the macrocycle indeed experiences significant librational motion on a time scale that is short compared to the NMR measurement time. This finding is in full quantitative support of the dominant rotational motion exhibited by the BChl macrocycle estimated from early MD simulations
