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The Samians on Ikaria : communities, power and island networks in the Hellenistic and Roman Aegean
No full textSeven inscriptions from Oine on Ikaria that refer to Samians residing on the island have long been used to argue the case for Samian political control over Ikaria. This article seeks to reassess what these inscriptions tell us about Samian–Ikarian interactions by exploring different models of connectivity for the two islands. Specifically, this article considers short-range mobility, and the capacity of each island to perform various political functions
The chemical logic of enzymatic lignin degradation
No full textLignin is an aromatic heteropolymer, found in plant cell walls as 20–30% of lignocellulose. It represents the most abundant source of renewable aromatic carbon in the biosphere, hence, if it could be depolymerised efficiently, then it would be a highly valuable source of renewable aromatic chemicals. However, lignin presents a number of difficulties for biocatalytic or chemocatalytic breakdown. Research over the last 10 years has led to the identification of new bacterial enzymes for lignin degradation, and the use of metabolic engineering to generate useful bioproducts from microbial lignin degradation. The aim of this article is to discuss the chemical mechanisms used by lignin-degrading enzymes and microbes to break down lignin, and to describe current methods for generating aromatic bioproducts from lignin using enzymes and engineered microbes
Interpretation of ion cyclotron emission from sub-Alfvénic beam-injected ions heated plasmas soon after L-H mode transition in EAST
No full textIon cyclotron emission (ICE) at deuterium ion cyclotron harmonics, driven by sub-Alfvénic beam-injected deuterium ions, has been observed by the high-frequency B-dot probe in the EAST tokamak. The origin of ICE shifts from the plasma core to the plasma edge soon after an L-H mode transition, where the beam-injected deuterium ions have a relatively peak bump-on tail structure in the energy direction and a very intense pitch angle anisotropy. Based on the fast ion distribution function obtained from the TRANSP/NUBEAM code, together with a linear analysis theory of magnetoacoustic cyclotron instability (MCI), the growth rates of MCI could be calculated. It is shown that MCI, resulting in the generation of obliquely propagating fast Alfvén waves at deuterium ion cyclotron harmonics, can occur under such conditions. And the temporal evolution of the MCI growth rate closely follows that of the observed ICE amplitude in the EAST
Geometric bounds on the fastest mixing Markov chain
No full textIn the Fastest Mixing Markov Chain problem, we are given a graph G=(V,E) and desire the discrete-time Markov chain with smallest mixing time τ subject to having equilibrium distribution uniform on V and non-zero transition probabilities only across edges of the graph.
It is well-known that the mixing time τRW of the lazy random walk on G is characterised by the edge conductance Φ of G via Cheeger’s inequality: Φ^-1<~τRW<~Φ^-2log|V|. Analogously, we characterise the fastest mixing time τ* via a Cheeger-type inequality but for a different geometric quantity, namely the vertex conductance Ψ of G: Ψ^-1<~τ*<~Ψ^-2(log|V|)^2.
This characterisation forbids fast mixing for graphs with small vertex conductance. To bypass this fundamental barrier, we consider Markov chains on G with equilibrium distribution which need not be uniform, but rather only ε-close to uniform in total variation. We show that it is always possible to construct such a chain with mixing time τ<~ε^-1(diamG)^2log|V|.
Finally, we discuss analogous questions for continuous-time and time-inhomogeneous chains
Congolese cultural production in Africa and the world
Get PDFAs an object of study, Congolese culture defies ready-made definitions. This inherent complexity has its roots in history. The frontiers of the Democratic Republic of the Congo (DRC) were decided at the Berlin Conference in 1884–85.1 By creating the Congo Free State (CFS), Leopold II, the king of the Belgians, presided over a large ensemble of peoples, such as the Kongo, Lunda, Luba, and Kuba, who had hitherto shared and often competed for land and resources in Central Africa. Before this, the kingdom of Kongo — a huge but scarcely populated political entity encompassing parts of present-day DRC, the Republic of the Congo, and Angola2 — had been gradually Christianized from the late fifteenth century onwards. Even though the cross-cultural traces of this process are extensive, not only in Central Africa but also in Europe and Latin America,3 it was not before the end of the nineteenth century that the DRC — under its previous appellations, CFS (1885–1908) and Belgian Congo (1908–60)4 — experienced a full-scale version of western modernity
Exploring the factor structure of the Adolescent Form of the Francis Psychological Type and Emotional Temperament Scales (FPTETSA) among Canadian Baptist youth : full form and short form
Get PDFThe Francis Psychological Type and Emotional Temperament Scales (FPTETS) operationalise the four components of the psychological-type model of personality alongside the fifth component of emotional temperament. The ten-item scales have been employed in research as continuous variables that explain individual differences in a wide range of religious beliefs and attitudes. The present study tested the factor structure of the adolescent form of the instrument (FPTETSA) and proposes a short form (FPTETSA-S) in which each of the five scales comprises six items, drawing on data provided by 360 Canadian Baptist youth. Both the full scales and the short scales are commended for use where the need is for continuous scale scores rather than generating psychological type categories
Ancient solutions and translators of Lagrangian mean curvature flow
Get PDFSuppose that ℳ is an almost calibrated, exact, ancient solution of Lagrangian mean curvature flow in Cn. We show that if ℳ has a blow-down given by the static union of two Lagrangian subspaces with distinct Lagrangian angles that intersect along a line, then ℳ is a translator. In particular in C2, all almost calibrated, exact, ancient solutions of Lagrangian mean curvature flow with entropy less than 3 are special Lagrangian, a union of planes, or translators
Community postnatal care delivery in England since Covid-19 : a qualitative study of midwifery leaders' perspectives and strategies.
Get PDFCOVID-19 impacted negatively on maternity care experiences of women and staff. Understanding the emergency response is key to inform future plans. Before the COVID-19 pandemic, experts highlighted concerns about UK community postnatal care, and its impact on long-term health, wellbeing, and inequalities. These appear to have been exacerbated by the pandemic. To explore community postnatal care provision during and since the pandemic across a large diverse UK region. A descriptive qualitative approach. Virtual semi-structured interviews conducted November 2022-February 2023. All regional midwifery community postnatal care leaders were invited to participate. 11/13 midwifery leaders participated. Three main themes were identified: Changes to postnatal care (strategic response, care on the ground); Impact of postnatal care changes (staff and women's experiences); and Drivers of postnatal care changes in (COVID-19, workforce issues). Changes to postnatal care during the pandemic included introduction of virtual care, increased role of Maternity Support Workers, and moving away from home visits to clinic appointments. This has largely continued without evaluation. The number of care episodes provided for low and high-risk families appears to have changed little. Those requiring additional support but not deemed highest risk appear to have been most impacted. Staffing levels influenced amount and type of care provided. There was little inter-organisation collaboration in the postnatal pandemic response. Changes to postnatal care provision introduced more efficient working practices. However, evaluation is needed to ensure ongoing safe, equitable and individualised care provision post pandemic within limited resources
The essentials for implementing and operating hospital at home : lessons learned from UK health care professionals
No full textMethods
The aim was to capture the implementation lessons that HaH professionals had learnt before and during the COVID-19 pandemic. In-depth, semistructured individual or group interviews (n = 11) were conducted with a purposive sample of 16 health care professionals (8 doctors, 5 nurses, 2 therapists, and 1 physician associate) from 11 UK-based HaH services. All interviews were recorded and then transcribed verbatim and analyzed thematically using Framework Analysis.1