Phase Separation in Peptide Aggregation Processes - Multicanonical Study of a Mesoscopic Model

We have performed multicanonical computer simulations of a small system of short protein-like heteropolymers and found that their aggregation transition possesses similarities to first-order phase separation processes. Not being a phase transition in the thermodynamic sense, the observed folding-binding behavior exhibits fascinating features leading to the conclusion that the temperature is no suitable control parameter in the transition region. More formally, for such small systems the microcanonical interpretation is more favorable than the typically used canonical picture.Comment: 3 pages, 1 figur

Thermodynamics of Peptide Aggregation Processes. An Analysis from Perspectives of Three Statistical Ensembles

We employ a mesoscopic model for studying aggregation processes of protein-like hydrophobic-polar heteropolymers. By means of multicanonical Monte Carlo computer simulations, we find strong indications that peptide aggregation is a phase separation process, in which the microcanonical entropy exhibits a convex intruder due to nonnegligible surface effects of the small systems. We analyze thermodynamic properties of the conformational transitions accompanying the aggregation process from the multicanonical, canonical, and microcanonical perspective. It turns out that the microcanonical description is particularly advantageous as it allows for unraveling details of the phase-separation transition in the thermodynamic region, where the temperature is not a suitable external control parameter anymore.Comment: 10 pages, 8 figure

Health professionals' views on maternity care for women with physical disabilities: a qualitative study

Background: During pregnancy, childbirth and puerperium, women receive care from a range of health professionals, particularly midwives. To assess the current situation of maternity care for women with physical disabilities in Austria, this study investigated the perceptions and experiences of health professionals who have provided care for women with disabilities during pregnancy, childbirth and postpartum. Methods: The viewpoints of the participating health professionals were evaluated by means of semistructured interviews followed by an inductive qualitative content analysis of the interview transcripts, as proposed by Mayring. Results: Four main categories emerged from the inductive content analysis: (i) structural conditions and accessibility, (ii) interprofessional teamwork and cooperation, (iii) action competence, and (iv) diversity-sensitive attitudes. According to the participating health professionals, the structural conditions were frequently not suitable for providing targeted group-oriented care services. Additionally, a shortage of time and staff resources also limited the necessary flexibility of treatment measures in the care of mothers with physical disabilities. The importance of interprofessional teamwork for providing adequate care was highlighted. The health professionals regarded interprofessionalism as an instrument of quality assurance and team meetings as an elementary component of high-quality care. On the other hand, the interviewees perceived a lack of action competence that was attributed to a low number of cases and a corresponding lack of experience and routine. Regarding diversity-sensitive attitudes, it became apparent that the topic of mothers with physical disabilities in care posed challenges to health professionals that influenced their natural handling of the interactions. Conclusion: The awareness of one’s own attitudes towards diversity, in the perinatal context in particular, influences professional security and sovereignty as well as the quality of care of women with disabilities. There is a need for optimization in the support and care of women with physical disabilities during pregnancy, childbirth and puerperium

Design & KI

In diesem Bericht werden die wichtigsten Begriffe aus dem Bereich des (Produkt)Designs aus dem Blickwinkel der künstlichen Intelligenz untersucht. Der Schwerpunkt liegt dabei nicht so sehr auf den technischen Details von existierenden Designsystemen als vielmehr in der Untersuchung der wesentlichen Konzepte wie Designmodelle, Modelle des wissensbasierten Designs, innovatives Design, etc. auf einem informellen Level, die der grundsätzlichen Beschreibung des Vorgehens eines Experten beim Design genügen

User-based redistribution in free-floating bike sharing systems

We investigate the problem of user-based redistribution for free-floating bike sharing systems (BSS). We present a stochastic model of the bike dynamics and we show that the spatial distribution of bikes is correlated. This is specific to free-floating systems and it results in a substantially reduced service level. Offering incentives to users may stimulate them to change their behavior and usage pattern. We analyze drop-off incentives, derive an incentive methodology and study its potential. We show that by implementing a smart incentive system, the number of bikes for establishing a specific service level can be reduced significantly, even if only a minority of users participates. Under realistic behavioral assumptions, 30–50% reduction of bikes is achievable, which converts into substantial costs savings for the operator. Our research was carried out in the context of the development of the new e-bike sharing system “smide” in Zurich, launched in 2017. The incentive approach has been implemented and tested in a field test

Hierarchies in Nucleation Transitions

We discuss the hierarchy of subphase transitions in first-order-like nucleation processes for an exemplified aggregation transition of heteropolymers. We perform an analysis of the microcanonical entropy, i.e., the density of states is considered as the central statistical system quantity since it connects system-specific entropic and energetic information in a natural and unique way.Comment: 15 pages, 3 figures, Proceedings of the Computational Physics Conference CCP 2010, Jun 23-27, 2010, Trondheim, Norwa