Design of crystal-like aperiodic solids with selective disorder--phonon coupling

Functional materials design normally focuses on structurally-ordered systems because disorder is considered detrimental to many important physical properties. Here we challenge this paradigm by showing that particular types of strongly-correlated disorder can give rise to useful characteristics that are inaccessible to ordered states. A judicious combination of low-symmetry building unit and high-symmetry topological template leads to aperiodic "procrystalline" solids that harbour this type of topological disorder. We identify key classes of procrystalline states together with their characteristic diffraction behaviour, and establish a variety of mappings onto known and target materials. Crucially, the strongly-correlated disorder we consider is associated with specific sets of modulation periodicities distributed throughout the Brillouin zone. Lattice dynamical calculations reveal selective disorder-phonon coupling to lattice vibrations characterised by these same periodicities. The principal effect on the phonon spectrum is to bring about dispersion in energy rather than wave-vector, as in the poorly-understood "waterfall" effect observed in relaxor ferroelectrics. This property of procrystalline solids suggests a mechanism by which strongly-correlated topological disorder might allow new and useful functionalities, including independently-optimised thermal and electronic transport behaviour as required for high-performance thermoelectrics.Comment: 4 figure

The effect of the COVID-19 health disruptions on breast cancer mortality for older women: A semi-Markov modelling approach

We propose a methodology to quantify the impact on breast cancer mortality of diagnostic delays caused by public health measures introduced as a response to the COVID-19 pandemic. These measures affected cancer pathways by halting cancer screening, delaying diagnostic tests, and reducing the numbers of patients starting treatment. We introduce a semi-Markov model, to quantify the impact of the pandemic based on publicly available population data for women age 65{89 years in England and relevant medical literature. We quantify age-specific excess deaths, for a period up to 5 years, along with years of life expectancy lost and change in cancer mortality by cancer stage. Our analysis suggests a 3-6% increase in breast cancer deaths, corresponding to more than 40 extra deaths, per 100,000 women, after age 65 years old over 5 years, and a 4-6% increase in registrations of advanced (Stage 4) breast cancer. Our modelling approach exhibits consistent results in sensitivity analyses, providing a model that can account for changes in breast cancer diagnostic and treatment services

Insurance pricing for breast cancer under different multiple state models

In this paper we consider pricing of insurance contracts for breast cancer risk based on three multiple state models. Using population data in England and data from the medical literature, we calibrate a collection of semi-Markov and Markov models. Considering an industry-based Markov model as a baseline model, we demonstrate the strengths of a more detailed model while showing the importance of accounting for duration dependence in transition rates. We quantify age-specific cancer incidence and cancer survival by stage along with type-specific mortality rates based on the semi-Markov model which accounts for unobserved breast cancer cases and progression through breast cancer stages. Using the developed models, we obtain actuarial net premiums for a specialised critical illness and life insurance product. Our analysis shows that the semi-Markov model leads to results aligned with empirical evidence. Our findings point out the importance of accounting for the time spent with diagnosed or undiagnosed pre-metastatic breast cancer in actuarial applications

Fructan synthesis, accumulation, and polymer traits I:Festulolium chromosome substitution lines

The fructans found as storage carbohydrates in temperate forage grasses have a physiological role in regrowth and stress tolerance. They are also important for the nutritional value of fresh and preserved livestock feeds, and are potentially useful as feedstocks for biorefining. Seasonal variation in fructan content and the capacity for de novo fructan synthesis have been examined in a Festulolium monosomic substitution line family to investigate variation in the polymers produced by grasses in the ryegrass-fescue complex. There were significant differences between ryegrass and fescue. Fescue had low polymeric fructan content and a high oligomer/polymer ratio; synthesis of polymers longer than degree of polymerisation 6 (DP6) from oligomers was slow. However, extension of polymer length from DP10/DP20 upwards appeared to occur relatively freely, and, unlike ryegrass, fescue had a relatively even spread of polymer chain lengths above DP20. This included the presence of some very large polymers. Additionally fescue retained high concentrations of fructan, both polymeric and oligomeric, during conditions of low source/high sink demand. There were indications that major genes involved in the control of some of these traits might be located on fescue chromosome 3 opening the possibility to develop grasses optimised for specific applications

A Grounded Analysis of Player-Described Board Game Immersion

Substantial research has explored the experience of immersion in digital games, but it is unclear whether this phenomenon extends to other game genres such as board games. Immersion is a concept widely discussed in the board game community by both developers and players and yet there is relatively little research in the area. This paper presents a grounded theory analysis of board game players’ online discussions of immersion. This data is augmented by interviews with five board game players describing their experiences of immersion. The resultant analysis highlights that board game players discuss immersion in terms of both engrossment in the challenge of the game, and submergence within the game world the board game creates. We also focus on elements of game play which players reported in helping and hindering their immersion; importantly these elements do not always come from the game itself. We conclude that board game immersion shares similarities with the literature on immersion in digital games, despite the lack of multimedia interactio

Translation of Diverse Aramid- And 1,3-Dicarbonyl-peptides by Wild Type Ribosomes in Vitro

Here, we report that wild type Escherichia coli ribosomes accept and elongate precharged initiator tRNAs acylated with multiple benzoic acids, including aramid precursors, as well as malonyl (1,3-dicarbonyl) substrates to generate a diverse set of aramid-peptide and polyketide-peptide hybrid molecules. This work expands the scope of ribozyme- and ribosome-catalyzed chemical transformations, provides a starting point for in vivo translation engineering efforts, and offers an alternative strategy for the biosynthesis of polyketide-peptide natural products

Fructan synthesis, accumulation and polymer traits II:Fructan pools in populations of perennial ryegrass (Lolium perenne L.) with variation for water-soluble carbohydrate and candidate genes were not correlated with biosynthetic activity and demonstrated constraints to polymer chain extension

Differences have been shown between ryegrass and fescue within the Festulolium subline introgression family for fructan synthesis, metabolism and polymer-size traits. It is well-established that there is considerable variation for water-soluble carbohydrate and fructan content within perennial ryegrass. However there is much still to be discovered about the fructan polymer pool in this species, especially in regard to its composition and regulation. It is postulated that similar considerable variation for polymer traits may exist, providing useful polymers for biorefining applications. Seasonal effects on fructan content together with fructan synthesis and polymer-size traits have been examined in diverse perennial ryegrass material comprising contrasting plants from a perennial ryegrass F2 mapping family and from populations produced by three rounds of phenotypic selection. Relationships with copy number variation in candidate genes have been investigated. There was little evidence of any variation in fructan metabolism across this diverse germplasm under these conditions that resulted in substantial differences in the complement of fructan polymers present in leaf tissue at high water-soluble carbohydrate concentrations. The importance of fructan synthesis during fructan accumulation was unclear as fructan content and polymer characteristics in intact plants during the growing season did not reflect the capacity for de novo synthesis. However, the retention of fructan in environmental conditions favouring high sink / low source demand may be an important component of the high sugar trait and the roles of breakdown and turnover are discussed

Negative linear compressibility exhibited by the hybrid perovskite [(NH2)3C]Er(HCO2)2(C2O4)

Extended framework materials with specific topologies can exhibit unusual mechanical behaviour, such as expanding in one direction under hydrostatic (uniform) pressure, known as negative linear compressibility (NLC). Here, two hybrid perovskite frameworks with winerack structures, a known NLC topology, are investigated under pressure. [C(NH2)3]Er(HCO2)2(C2O4) exhibits NLC from ambient pressure to 2.63(10) GPa, the first reported NLC hybrid perovskite from ambient pressure. However, isostructural [(CH3)2NH2]Er(HCO2)2(C2O4) instead compresses relatively moderately along all axes before it undergoes a phase transition above 0.37(10) GPa. The differences in the mechanical properties can be interpreted from differences in host–guest interactions within these frameworks, primarily their hydrogen bond networks