RESUMO
The Kuramoto model and its generalizations have been broadly employed to characterize and mechanistically understand various collective dynamical phenomena, especially the emergence of synchrony among coupled oscillators. Despite almost five decades of research, many questions remain open, in particular, for finite-size systems. Here, we generalize recent work [Thümler et al., Phys. Rev. Lett. 130, 187201 (2023)] on the finite-size Kuramoto model with its state variables analytically continued to the complex domain and also complexify its system parameters. Intriguingly, systems of two units with purely imaginary coupling do not actively synchronize even for arbitrarily large magnitudes of the coupling strengths, |K|â∞, but exhibit conservative dynamics with asynchronous rotations or librations for all |K|. For generic complex coupling, both traditional phase-locked states and asynchronous states generalize to complex locked states, fixed points off the real subspace that exist even for arbitrarily weak coupling. We analyze a new collective mode of rotations exhibiting finite, yet arbitrarily large rotation numbers. Numerical simulations for large networks indicate a novel form of discontinuous phase transition. We close by pointing to a range of exciting questions for future research.
RESUMO
The structure of the carbohydrate moiety of a natural phenolic glycoside can have a significant effect on the molecular interactions and physicochemical and pharmacokinetic properties of the entire compound, which may include anti-inflammatory and anticancer activities. The enzyme 6-O-α-rhamnosyl-ß-glucosidase (EC 3.2.1.168) has the capacity to transfer the rutinosyl moiety (6-O-α-l-rhamnopyranosyl-ß-d-glucopyranose) from 7-O-rutinosylated flavonoids to hydroxylated organic compounds. This transglycosylation reaction was optimized using hydroquinone (HQ) and hesperidin as rutinose acceptor and donor, respectively. Since HQ undergoes oxidation in a neutral to alkaline aqueous environment, the transglycosylation process was carried out at pH values ≤6.0. The structure of 4-hydroxyphenyl-ß-rutinoside was confirmed by NMR, that is, a single glycosylated product with a free hydroxyl group was formed. The highest yield of 4-hydroxyphenyl-ß-rutinoside (38%, regarding hesperidin) was achieved in a 2-h process at pH 5.0 and 30 °C, with 36 mM OH-acceptor and 5% (v/v) cosolvent. Under the same conditions, the enzyme synthesized glycoconjugates of various phenolic compounds (phloroglucinol, resorcinol, pyrogallol, catechol), with yields between 12% and 28% and an apparent direct linear relationship between the yield and the pKa value of the aglycon. This work is a contribution to the development of convenient and sustainable processes for the glycosylation of small phenolic compounds.
Assuntos
Acremonium/enzimologia , Dissacarídeos/química , Proteínas Fúngicas/química , Glicosídeo Hidrolases/química , Acremonium/genética , Dissacarídeos/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosilação , Concentração de Íons de HidrogênioRESUMO
BACKGROUND: Automated Vehicles (AVs) are central to the new mobility paradigm that promises to transform transportation systems and cities across the globe. To date, much of the research on AVs has focused on technological advancements with little emphasis on how this emerging technology will impact population-level health. This scoping study examines the potential health impacts of AVs based on the existing literature. METHODS: Using Arksey and O'Malley's scoping protocol, we searched academic and 'grey' literature to anticipate the effects of AVs on human health. RESULTS: Our search captured 43 information sources that discussed a least one of the five thematic areas related to health. The bulk of the evidence is related to road safety (n = 37), followed by a relatively equal distribution between social equity (n = 24), environment (n = 22), lifestyle (n = 20), and built environment (n = 18) themes. There is general agreement that AVs will improve road safety overall, thus reducing injuries and fatalities from human errors in operating motorized vehicles. However, the relationships with air quality, physical activity, and stress, among other health factors may be more complex. The broader health implications of AVs will be dependent on how the technology is adopted in various transportation systems. Regulatory action will be a significant determinant of how AVs could affect health, as well as how AVs influence social and environmental determinants of health. CONCLUSION: To support researchers and practitioners considering the health implications of AVs, we provide a conceptual map of the direct and indirect linkages between AV use and health outcomes. It is important that stakeholders, including public health agencies work to ensure that population health outcomes and equitable distribution of health impacts are priority considerations as regulators develop their response to AVs. We recommend that public health and transportation officials actively monitor trends in AV introduction and adoption, regulators focus on protecting human health and safety in AV implementation, and researchers work to expand the body of evidence surrounding AVs and population health.
Assuntos
Automação , Saúde da População , Saúde Pública , Meios de Transporte , Poluição do Ar , Cidades , Exercício Físico , HumanosRESUMO
PURPOSE: The aim of this study was to evaluate cancer patients' need for information, their communication and usage of social media. METHODS: We developed a standardized questionnaire comprising sections on information needs, communication behavior and usage of social media with respect to cancer and combined this with a validated instrument on eHealth literacy for patients. This questionnaire was provided online and with the help of bloggers and leaders of social media groups, distributed in their networks. RESULTS: The Internet was the most important information source (n = 308; 77.4%). Yet, most of the participants wanted to get information from their doctor (n = 342; 85.9%). With respect to trust in a source of information, oncologists were named most often (n = 285; 71.6%). On the one hand, many participants got in contact with others, especially peers, via social media (n = 319; 80.3%) with a growing bond to their family members on the other hand (n = 324; 81.6%). The cancer diagnosis was an impulse for starting with active participation in social media for some participants (n = 196; 49.2%). CONCLUSIONS: With social media gaining importance as source of information for patients, improving the quality of information in these networks is an important task in health care systems.