Multiscale analysis of a spatially heterogeneous microscopic traffic model

The microscopic Optimal Velocity (OV) model is posed on an inhomogeneous ring-road, consisting of two spatial regimes which differ by a scaled OV function. Parameters are chosen throughout for which all uniform flows are linearly stable. The large time behaviour of this discrete system is stationary and exhibits three types of macroscopic traffic pattern, each consisting of plateaus joined together by sharp interfaces. At a coarse level, these patterns are determined by simple flow and density balances, which in some cases have non-unique solutions. The theory of characteristics for the classical Lighthill–Whitham PDE model is then applied to explain which pattern the OV model selects. A global analysis of a second-order PDE model is then performed in an attempt to explain some qualitative details of interface structure. Finally, the full microscopic model is analysed at the linear level to explain features which cannot be described by the present macroscopic approache

A prevalence survey of patients with indwelling urinary catheters on district nursing caseloads in the United Kingdom: the community urinary catheter management (CCaMa) study

Background: Catheter-associated urinary tract infection (CAUTI) is common in both hospitals and the community. Aim: To investigate the prevalence of indwelling urinary catheters on district nursing caseloads in the United Kingdom (UK). Method: Participants were recruited through the Infection Prevention Society (IPS). An electronic survey was undertaken on a single day between November 2017 and January 2018. Data were analysed using descriptive statistics. Findings: 49,575 patients were included in the survey of whom 5352 had an indwelling urinary catheter. This gave a point prevalence of 10.8% [95%CI 10.53-11.07], which varied between organisations, ranging from 2.36% [95% CI 2.05-2.73] to 22.02% [95% CI 20.12-24.05]. 5% of catheters were newly-placed (within four weeks). Of these, most (77%) had a documented indication for insertion. Only half of patients with a newly-placed catheter had a plan for its removal. This varied between organisations from 20% to 96%. Only 13% of patients had a patient held management plan or ‘catheter passport’ but these patients were significantly more likely to also have an active removal plan (28/36, 78% vs 106/231, 46%, p< 0.0001). Alternative bladder management strategies had been considered for 70/267 (26%) patients. Discussion: The management of patients with an indwelling urinary catheter represents a significant component of district nursing caseloads. Given the high proportion of newly-catheterised patients without an active management plan for removal of the catheter, the establishment of an optimal management pathway should be the focus of future prevention efforts

Structural phase transition in IrTe2_2: A combined study of optical spectroscopy and band structure calculations

Ir$_{1-x}$Pt$_x$Te$_2$ is an interesting system showing competing phenomenon between structural instability and superconductivity. Due to the large atomic numbers of Ir and Te, the spin-orbital coupling is expected to be strong in the system which may lead to nonconventional superconductivity. We grew single crystal samples of this system and investigated their electronic properties. In particular, we performed optical spectroscopic measurements, in combination with density function calculations, on the undoped compound IrTe$_2$ in an effort to elucidate the origin of the structural phase transition at 280 K. The measurement revealed a dramatic reconstruction of band structure and a significant reduction of conducting carriers below the phase transition. We elaborate that the transition is not driven by the density wave type instability but caused by the crystal field effect which further splits/separates the energy levels of Te (p$_x$, p$_y$) and Te p$_z$ bands.Comment: 16 pages, 5 figure

The importance of metagenomic surveys to microbial ecology: or why Darwin would have been a metagenomic scientist

Scientific discovery is incremental. The Merriam-Webster definition of 'Scientific Method' is "principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses". Scientists are taught to be excellent observers, as observations create questions, which in turn generate hypotheses. After centuries of science we tend to assume that we have enough observations to drive science, and enable the small steps and giant leaps which lead to theories and subsequent testable hypotheses. One excellent example of this is Charles Darwin's Voyage of the Beagle, which was essentially an opportunistic survey of biodiversity. Today, obtaining funding for even small-scale surveys of life on Earth is difficult; but few argue the importance of the theory that was generated by Darwin from his observations made during this epic journey. However, these observations, even combined with the parallel work of Alfred Russell Wallace at around the same time have still not generated an indisputable 'law of biology'. The fact that evolution remains a 'theory', at least to the general public, suggests that surveys for new data need to be taken to a new level

Human kin detection

Natural selection has favored the evolution of behaviors that benefit not only one's genes, but also their copies in genetically related individuals. These behaviors include optimal outbreeding (choosing a mate that is neither too closely related, nor too distant), nepotism (helping kin), and spite (hurting non-kin at a personal cost), and all require some form of kin detection or kin recognition. Yet, kinship cannot be assessed directly; human kin detection relies on heuristic cues that take into account individuals' context (whether they were reared by our mother, or grew up in our home, or were given birth by our spouse), appearance (whether they smell or look like us), and ability to arouse certain feelings (whether we feel emotionally close to them). The uncertainties of kin detection, along with its dependence on social information, create ample opportunities for the evolution of deception and self-deception. For example, babies carry no unequivocal stamp of their biological father, but across cultures they are passionately claimed to resemble their mother's spouse; to the same effect, neutral' observers are greatly influenced by belief in relatedness when judging resemblance between strangers. Still, paternity uncertainty profoundly shapes human relationships, reducing not only the investment contributed by paternal versus maternal kin, but also prosocial behavior between individuals who are related through one or more males rather than females alone. Because of its relevance to racial discrimination and political preferences, the evolutionary pressure to prefer kin to non-kin has a manifold influence on society at large

A Fresh Start or the Devil You Know? Examining Relationships Between Release Location Choices, Community Experiences, and Recidivism for High-Risk Parolees

This study investigated the effects of residential relocation in a sample of 282 high-risk male offenders paroled from New Zealand prisons. Initially we compared those returning to their old neighborhoods (devil you know) and those released to a new location (fresh start). This second category was then further divided: those released to a new location voluntarily (fresh start-voluntary) versus those forced to start anew at the behest of the parole board that was releasing them (fresh start-duress). All three categories were then compared on the quality of their community experiences and recidivism. Results indicated that parolees returning by choice to either their old neighborhood or a new location each were reconvicted in the first year after release at approximately the same rate; however, parolees relocating to a new area at the direction of the parole board (under duress) were reconvicted at a higher rate than those in either of the voluntary location categories. Significant group differences in ratings of community life quality were few, but there were some indications that compared with those choosing to return to a familiar location, making a voluntary residential relocation may lead to better parole experiences, particularly in terms of avoiding criminal peers, and that making a residential relocation under duress may lead to poorer parole experiences than for those returning to a familiar location

A high-precision age estimate of the Holocene Plinian eruption of Mount Mazama, Oregon, USA

© The Author(s) 2015 The climactic eruption of Mount Mazama in Oregon, North America, resulted in the deposition of the most widespread Holocene tephra deposit in the conterminous United States and south-western Canada. The tephra forms an isochronous marker horizon for palaeoenvironmental, sedimentary and archaeological reconstructions, despite the current lack of a precise age estimate for the source eruption. Previous radiocarbon age estimates for the eruption have varied, and Greenland ice-core ages are in disagreement. For the Mazama tephra to be fully utilised in tephrochronology and palaeoenvironmental research, a refined (precise and accurate) age for the eruption is required. Here, we apply a meta-analysis of all previously published radiocarbon age estimations (n = 81), and perform Bayesian statistical modelling to this data set, to provide a refined age of 7682–7584 cal. yr BP (95.4% probability range). Although the depositional histories of the published ages vary, this estimate is consistent with that estimated from the GISP2 ice-core of 7627 ± 150 yr BP (Zdanowicz et al., 1999)

Strong solutions of the thin film equation in spherical geometry

We study existence and long-time behaviour of strong solutions for the thin film equation using a priori estimates in a weighted Sobolev space. This equation can be classified as a doubly degenerate fourth-order parabolic and it models coating flow on the outer surface of a sphere. It is shown that the strong solution asymptotically decays to the flat profile